v4.19.13 snapshot.
diff --git a/fs/ext2/Kconfig b/fs/ext2/Kconfig
new file mode 100644
index 0000000..894e4c5
--- /dev/null
+++ b/fs/ext2/Kconfig
@@ -0,0 +1,40 @@
+config EXT2_FS
+ tristate "Second extended fs support"
+ help
+ Ext2 is a standard Linux file system for hard disks.
+
+ To compile this file system support as a module, choose M here: the
+ module will be called ext2.
+
+ If unsure, say Y.
+
+config EXT2_FS_XATTR
+ bool "Ext2 extended attributes"
+ depends on EXT2_FS
+ help
+ Extended attributes are name:value pairs associated with inodes by
+ the kernel or by users (see the attr(5) manual page for details).
+
+ If unsure, say N.
+
+config EXT2_FS_POSIX_ACL
+ bool "Ext2 POSIX Access Control Lists"
+ depends on EXT2_FS_XATTR
+ select FS_POSIX_ACL
+ help
+ Posix Access Control Lists (ACLs) support permissions for users and
+ groups beyond the owner/group/world scheme.
+
+ If you don't know what Access Control Lists are, say N
+
+config EXT2_FS_SECURITY
+ bool "Ext2 Security Labels"
+ depends on EXT2_FS_XATTR
+ help
+ Security labels support alternative access control models
+ implemented by security modules like SELinux. This option
+ enables an extended attribute handler for file security
+ labels in the ext2 filesystem.
+
+ If you are not using a security module that requires using
+ extended attributes for file security labels, say N.
diff --git a/fs/ext2/Makefile b/fs/ext2/Makefile
new file mode 100644
index 0000000..311479d
--- /dev/null
+++ b/fs/ext2/Makefile
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux ext2-filesystem routines.
+#
+
+obj-$(CONFIG_EXT2_FS) += ext2.o
+
+ext2-y := balloc.o dir.o file.o ialloc.o inode.o \
+ ioctl.o namei.o super.o symlink.o
+
+ext2-$(CONFIG_EXT2_FS_XATTR) += xattr.o xattr_user.o xattr_trusted.o
+ext2-$(CONFIG_EXT2_FS_POSIX_ACL) += acl.o
+ext2-$(CONFIG_EXT2_FS_SECURITY) += xattr_security.o
diff --git a/fs/ext2/acl.c b/fs/ext2/acl.c
new file mode 100644
index 0000000..224c04a
--- /dev/null
+++ b/fs/ext2/acl.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/acl.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include "ext2.h"
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * Convert from filesystem to in-memory representation.
+ */
+static struct posix_acl *
+ext2_acl_from_disk(const void *value, size_t size)
+{
+ const char *end = (char *)value + size;
+ int n, count;
+ struct posix_acl *acl;
+
+ if (!value)
+ return NULL;
+ if (size < sizeof(ext2_acl_header))
+ return ERR_PTR(-EINVAL);
+ if (((ext2_acl_header *)value)->a_version !=
+ cpu_to_le32(EXT2_ACL_VERSION))
+ return ERR_PTR(-EINVAL);
+ value = (char *)value + sizeof(ext2_acl_header);
+ count = ext2_acl_count(size);
+ if (count < 0)
+ return ERR_PTR(-EINVAL);
+ if (count == 0)
+ return NULL;
+ acl = posix_acl_alloc(count, GFP_KERNEL);
+ if (!acl)
+ return ERR_PTR(-ENOMEM);
+ for (n=0; n < count; n++) {
+ ext2_acl_entry *entry =
+ (ext2_acl_entry *)value;
+ if ((char *)value + sizeof(ext2_acl_entry_short) > end)
+ goto fail;
+ acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
+ acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
+ switch(acl->a_entries[n].e_tag) {
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ value = (char *)value +
+ sizeof(ext2_acl_entry_short);
+ break;
+
+ case ACL_USER:
+ value = (char *)value + sizeof(ext2_acl_entry);
+ if ((char *)value > end)
+ goto fail;
+ acl->a_entries[n].e_uid =
+ make_kuid(&init_user_ns,
+ le32_to_cpu(entry->e_id));
+ break;
+ case ACL_GROUP:
+ value = (char *)value + sizeof(ext2_acl_entry);
+ if ((char *)value > end)
+ goto fail;
+ acl->a_entries[n].e_gid =
+ make_kgid(&init_user_ns,
+ le32_to_cpu(entry->e_id));
+ break;
+
+ default:
+ goto fail;
+ }
+ }
+ if (value != end)
+ goto fail;
+ return acl;
+
+fail:
+ posix_acl_release(acl);
+ return ERR_PTR(-EINVAL);
+}
+
+/*
+ * Convert from in-memory to filesystem representation.
+ */
+static void *
+ext2_acl_to_disk(const struct posix_acl *acl, size_t *size)
+{
+ ext2_acl_header *ext_acl;
+ char *e;
+ size_t n;
+
+ *size = ext2_acl_size(acl->a_count);
+ ext_acl = kmalloc(sizeof(ext2_acl_header) + acl->a_count *
+ sizeof(ext2_acl_entry), GFP_KERNEL);
+ if (!ext_acl)
+ return ERR_PTR(-ENOMEM);
+ ext_acl->a_version = cpu_to_le32(EXT2_ACL_VERSION);
+ e = (char *)ext_acl + sizeof(ext2_acl_header);
+ for (n=0; n < acl->a_count; n++) {
+ const struct posix_acl_entry *acl_e = &acl->a_entries[n];
+ ext2_acl_entry *entry = (ext2_acl_entry *)e;
+ entry->e_tag = cpu_to_le16(acl_e->e_tag);
+ entry->e_perm = cpu_to_le16(acl_e->e_perm);
+ switch(acl_e->e_tag) {
+ case ACL_USER:
+ entry->e_id = cpu_to_le32(
+ from_kuid(&init_user_ns, acl_e->e_uid));
+ e += sizeof(ext2_acl_entry);
+ break;
+ case ACL_GROUP:
+ entry->e_id = cpu_to_le32(
+ from_kgid(&init_user_ns, acl_e->e_gid));
+ e += sizeof(ext2_acl_entry);
+ break;
+
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ e += sizeof(ext2_acl_entry_short);
+ break;
+
+ default:
+ goto fail;
+ }
+ }
+ return (char *)ext_acl;
+
+fail:
+ kfree(ext_acl);
+ return ERR_PTR(-EINVAL);
+}
+
+/*
+ * inode->i_mutex: don't care
+ */
+struct posix_acl *
+ext2_get_acl(struct inode *inode, int type)
+{
+ int name_index;
+ char *value = NULL;
+ struct posix_acl *acl;
+ int retval;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name_index = EXT2_XATTR_INDEX_POSIX_ACL_ACCESS;
+ break;
+ case ACL_TYPE_DEFAULT:
+ name_index = EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT;
+ break;
+ default:
+ BUG();
+ }
+ retval = ext2_xattr_get(inode, name_index, "", NULL, 0);
+ if (retval > 0) {
+ value = kmalloc(retval, GFP_KERNEL);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ retval = ext2_xattr_get(inode, name_index, "", value, retval);
+ }
+ if (retval > 0)
+ acl = ext2_acl_from_disk(value, retval);
+ else if (retval == -ENODATA || retval == -ENOSYS)
+ acl = NULL;
+ else
+ acl = ERR_PTR(retval);
+ kfree(value);
+
+ return acl;
+}
+
+static int
+__ext2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+ int name_index;
+ void *value = NULL;
+ size_t size = 0;
+ int error;
+
+ switch(type) {
+ case ACL_TYPE_ACCESS:
+ name_index = EXT2_XATTR_INDEX_POSIX_ACL_ACCESS;
+ break;
+
+ case ACL_TYPE_DEFAULT:
+ name_index = EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT;
+ if (!S_ISDIR(inode->i_mode))
+ return acl ? -EACCES : 0;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+ if (acl) {
+ value = ext2_acl_to_disk(acl, &size);
+ if (IS_ERR(value))
+ return (int)PTR_ERR(value);
+ }
+
+ error = ext2_xattr_set(inode, name_index, "", value, size, 0);
+
+ kfree(value);
+ if (!error)
+ set_cached_acl(inode, type, acl);
+ return error;
+}
+
+/*
+ * inode->i_mutex: down
+ */
+int
+ext2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+ int error;
+ int update_mode = 0;
+ umode_t mode = inode->i_mode;
+
+ if (type == ACL_TYPE_ACCESS && acl) {
+ error = posix_acl_update_mode(inode, &mode, &acl);
+ if (error)
+ return error;
+ update_mode = 1;
+ }
+ error = __ext2_set_acl(inode, acl, type);
+ if (!error && update_mode) {
+ inode->i_mode = mode;
+ inode->i_ctime = current_time(inode);
+ mark_inode_dirty(inode);
+ }
+ return error;
+}
+
+/*
+ * Initialize the ACLs of a new inode. Called from ext2_new_inode.
+ *
+ * dir->i_mutex: down
+ * inode->i_mutex: up (access to inode is still exclusive)
+ */
+int
+ext2_init_acl(struct inode *inode, struct inode *dir)
+{
+ struct posix_acl *default_acl, *acl;
+ int error;
+
+ error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
+ if (error)
+ return error;
+
+ if (default_acl) {
+ error = __ext2_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
+ posix_acl_release(default_acl);
+ }
+ if (acl) {
+ if (!error)
+ error = __ext2_set_acl(inode, acl, ACL_TYPE_ACCESS);
+ posix_acl_release(acl);
+ }
+ return error;
+}
diff --git a/fs/ext2/acl.h b/fs/ext2/acl.h
new file mode 100644
index 0000000..0f01c75
--- /dev/null
+++ b/fs/ext2/acl.h
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ File: fs/ext2/acl.h
+
+ (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+*/
+
+#include <linux/posix_acl_xattr.h>
+
+#define EXT2_ACL_VERSION 0x0001
+
+typedef struct {
+ __le16 e_tag;
+ __le16 e_perm;
+ __le32 e_id;
+} ext2_acl_entry;
+
+typedef struct {
+ __le16 e_tag;
+ __le16 e_perm;
+} ext2_acl_entry_short;
+
+typedef struct {
+ __le32 a_version;
+} ext2_acl_header;
+
+static inline size_t ext2_acl_size(int count)
+{
+ if (count <= 4) {
+ return sizeof(ext2_acl_header) +
+ count * sizeof(ext2_acl_entry_short);
+ } else {
+ return sizeof(ext2_acl_header) +
+ 4 * sizeof(ext2_acl_entry_short) +
+ (count - 4) * sizeof(ext2_acl_entry);
+ }
+}
+
+static inline int ext2_acl_count(size_t size)
+{
+ ssize_t s;
+ size -= sizeof(ext2_acl_header);
+ s = size - 4 * sizeof(ext2_acl_entry_short);
+ if (s < 0) {
+ if (size % sizeof(ext2_acl_entry_short))
+ return -1;
+ return size / sizeof(ext2_acl_entry_short);
+ } else {
+ if (s % sizeof(ext2_acl_entry))
+ return -1;
+ return s / sizeof(ext2_acl_entry) + 4;
+ }
+}
+
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+
+/* acl.c */
+extern struct posix_acl *ext2_get_acl(struct inode *inode, int type);
+extern int ext2_set_acl(struct inode *inode, struct posix_acl *acl, int type);
+extern int ext2_init_acl (struct inode *, struct inode *);
+
+#else
+#include <linux/sched.h>
+#define ext2_get_acl NULL
+#define ext2_set_acl NULL
+
+static inline int ext2_init_acl (struct inode *inode, struct inode *dir)
+{
+ return 0;
+}
+#endif
+
diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
new file mode 100644
index 0000000..33db133
--- /dev/null
+++ b/fs/ext2/balloc.c
@@ -0,0 +1,1559 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/balloc.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * Enhanced block allocation by Stephen Tweedie (sct@redhat.com), 1993
+ * Big-endian to little-endian byte-swapping/bitmaps by
+ * David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include "ext2.h"
+#include <linux/quotaops.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/cred.h>
+#include <linux/buffer_head.h>
+#include <linux/capability.h>
+
+/*
+ * balloc.c contains the blocks allocation and deallocation routines
+ */
+
+/*
+ * The free blocks are managed by bitmaps. A file system contains several
+ * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
+ * block for inodes, N blocks for the inode table and data blocks.
+ *
+ * The file system contains group descriptors which are located after the
+ * super block. Each descriptor contains the number of the bitmap block and
+ * the free blocks count in the block. The descriptors are loaded in memory
+ * when a file system is mounted (see ext2_fill_super).
+ */
+
+
+#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
+
+struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
+ unsigned int block_group,
+ struct buffer_head ** bh)
+{
+ unsigned long group_desc;
+ unsigned long offset;
+ struct ext2_group_desc * desc;
+ struct ext2_sb_info *sbi = EXT2_SB(sb);
+
+ if (block_group >= sbi->s_groups_count) {
+ ext2_error (sb, "ext2_get_group_desc",
+ "block_group >= groups_count - "
+ "block_group = %d, groups_count = %lu",
+ block_group, sbi->s_groups_count);
+
+ return NULL;
+ }
+
+ group_desc = block_group >> EXT2_DESC_PER_BLOCK_BITS(sb);
+ offset = block_group & (EXT2_DESC_PER_BLOCK(sb) - 1);
+ if (!sbi->s_group_desc[group_desc]) {
+ ext2_error (sb, "ext2_get_group_desc",
+ "Group descriptor not loaded - "
+ "block_group = %d, group_desc = %lu, desc = %lu",
+ block_group, group_desc, offset);
+ return NULL;
+ }
+
+ desc = (struct ext2_group_desc *) sbi->s_group_desc[group_desc]->b_data;
+ if (bh)
+ *bh = sbi->s_group_desc[group_desc];
+ return desc + offset;
+}
+
+static int ext2_valid_block_bitmap(struct super_block *sb,
+ struct ext2_group_desc *desc,
+ unsigned int block_group,
+ struct buffer_head *bh)
+{
+ ext2_grpblk_t offset;
+ ext2_grpblk_t next_zero_bit;
+ ext2_fsblk_t bitmap_blk;
+ ext2_fsblk_t group_first_block;
+
+ group_first_block = ext2_group_first_block_no(sb, block_group);
+
+ /* check whether block bitmap block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
+ offset = bitmap_blk - group_first_block;
+ if (!ext2_test_bit(offset, bh->b_data))
+ /* bad block bitmap */
+ goto err_out;
+
+ /* check whether the inode bitmap block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap);
+ offset = bitmap_blk - group_first_block;
+ if (!ext2_test_bit(offset, bh->b_data))
+ /* bad block bitmap */
+ goto err_out;
+
+ /* check whether the inode table block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_inode_table);
+ offset = bitmap_blk - group_first_block;
+ next_zero_bit = ext2_find_next_zero_bit(bh->b_data,
+ offset + EXT2_SB(sb)->s_itb_per_group,
+ offset);
+ if (next_zero_bit >= offset + EXT2_SB(sb)->s_itb_per_group)
+ /* good bitmap for inode tables */
+ return 1;
+
+err_out:
+ ext2_error(sb, __func__,
+ "Invalid block bitmap - "
+ "block_group = %d, block = %lu",
+ block_group, bitmap_blk);
+ return 0;
+}
+
+/*
+ * Read the bitmap for a given block_group,and validate the
+ * bits for block/inode/inode tables are set in the bitmaps
+ *
+ * Return buffer_head on success or NULL in case of failure.
+ */
+static struct buffer_head *
+read_block_bitmap(struct super_block *sb, unsigned int block_group)
+{
+ struct ext2_group_desc * desc;
+ struct buffer_head * bh = NULL;
+ ext2_fsblk_t bitmap_blk;
+
+ desc = ext2_get_group_desc(sb, block_group, NULL);
+ if (!desc)
+ return NULL;
+ bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
+ bh = sb_getblk(sb, bitmap_blk);
+ if (unlikely(!bh)) {
+ ext2_error(sb, __func__,
+ "Cannot read block bitmap - "
+ "block_group = %d, block_bitmap = %u",
+ block_group, le32_to_cpu(desc->bg_block_bitmap));
+ return NULL;
+ }
+ if (likely(bh_uptodate_or_lock(bh)))
+ return bh;
+
+ if (bh_submit_read(bh) < 0) {
+ brelse(bh);
+ ext2_error(sb, __func__,
+ "Cannot read block bitmap - "
+ "block_group = %d, block_bitmap = %u",
+ block_group, le32_to_cpu(desc->bg_block_bitmap));
+ return NULL;
+ }
+
+ ext2_valid_block_bitmap(sb, desc, block_group, bh);
+ /*
+ * file system mounted not to panic on error, continue with corrupt
+ * bitmap
+ */
+ return bh;
+}
+
+static void group_adjust_blocks(struct super_block *sb, int group_no,
+ struct ext2_group_desc *desc, struct buffer_head *bh, int count)
+{
+ if (count) {
+ struct ext2_sb_info *sbi = EXT2_SB(sb);
+ unsigned free_blocks;
+
+ spin_lock(sb_bgl_lock(sbi, group_no));
+ free_blocks = le16_to_cpu(desc->bg_free_blocks_count);
+ desc->bg_free_blocks_count = cpu_to_le16(free_blocks + count);
+ spin_unlock(sb_bgl_lock(sbi, group_no));
+ mark_buffer_dirty(bh);
+ }
+}
+
+/*
+ * The reservation window structure operations
+ * --------------------------------------------
+ * Operations include:
+ * dump, find, add, remove, is_empty, find_next_reservable_window, etc.
+ *
+ * We use a red-black tree to represent per-filesystem reservation
+ * windows.
+ *
+ */
+
+/**
+ * __rsv_window_dump() -- Dump the filesystem block allocation reservation map
+ * @rb_root: root of per-filesystem reservation rb tree
+ * @verbose: verbose mode
+ * @fn: function which wishes to dump the reservation map
+ *
+ * If verbose is turned on, it will print the whole block reservation
+ * windows(start, end). Otherwise, it will only print out the "bad" windows,
+ * those windows that overlap with their immediate neighbors.
+ */
+#if 1
+static void __rsv_window_dump(struct rb_root *root, int verbose,
+ const char *fn)
+{
+ struct rb_node *n;
+ struct ext2_reserve_window_node *rsv, *prev;
+ int bad;
+
+restart:
+ n = rb_first(root);
+ bad = 0;
+ prev = NULL;
+
+ printk("Block Allocation Reservation Windows Map (%s):\n", fn);
+ while (n) {
+ rsv = rb_entry(n, struct ext2_reserve_window_node, rsv_node);
+ if (verbose)
+ printk("reservation window 0x%p "
+ "start: %lu, end: %lu\n",
+ rsv, rsv->rsv_start, rsv->rsv_end);
+ if (rsv->rsv_start && rsv->rsv_start >= rsv->rsv_end) {
+ printk("Bad reservation %p (start >= end)\n",
+ rsv);
+ bad = 1;
+ }
+ if (prev && prev->rsv_end >= rsv->rsv_start) {
+ printk("Bad reservation %p (prev->end >= start)\n",
+ rsv);
+ bad = 1;
+ }
+ if (bad) {
+ if (!verbose) {
+ printk("Restarting reservation walk in verbose mode\n");
+ verbose = 1;
+ goto restart;
+ }
+ }
+ n = rb_next(n);
+ prev = rsv;
+ }
+ printk("Window map complete.\n");
+ BUG_ON(bad);
+}
+#define rsv_window_dump(root, verbose) \
+ __rsv_window_dump((root), (verbose), __func__)
+#else
+#define rsv_window_dump(root, verbose) do {} while (0)
+#endif
+
+/**
+ * goal_in_my_reservation()
+ * @rsv: inode's reservation window
+ * @grp_goal: given goal block relative to the allocation block group
+ * @group: the current allocation block group
+ * @sb: filesystem super block
+ *
+ * Test if the given goal block (group relative) is within the file's
+ * own block reservation window range.
+ *
+ * If the reservation window is outside the goal allocation group, return 0;
+ * grp_goal (given goal block) could be -1, which means no specific
+ * goal block. In this case, always return 1.
+ * If the goal block is within the reservation window, return 1;
+ * otherwise, return 0;
+ */
+static int
+goal_in_my_reservation(struct ext2_reserve_window *rsv, ext2_grpblk_t grp_goal,
+ unsigned int group, struct super_block * sb)
+{
+ ext2_fsblk_t group_first_block, group_last_block;
+
+ group_first_block = ext2_group_first_block_no(sb, group);
+ group_last_block = group_first_block + EXT2_BLOCKS_PER_GROUP(sb) - 1;
+
+ if ((rsv->_rsv_start > group_last_block) ||
+ (rsv->_rsv_end < group_first_block))
+ return 0;
+ if ((grp_goal >= 0) && ((grp_goal + group_first_block < rsv->_rsv_start)
+ || (grp_goal + group_first_block > rsv->_rsv_end)))
+ return 0;
+ return 1;
+}
+
+/**
+ * search_reserve_window()
+ * @rb_root: root of reservation tree
+ * @goal: target allocation block
+ *
+ * Find the reserved window which includes the goal, or the previous one
+ * if the goal is not in any window.
+ * Returns NULL if there are no windows or if all windows start after the goal.
+ */
+static struct ext2_reserve_window_node *
+search_reserve_window(struct rb_root *root, ext2_fsblk_t goal)
+{
+ struct rb_node *n = root->rb_node;
+ struct ext2_reserve_window_node *rsv;
+
+ if (!n)
+ return NULL;
+
+ do {
+ rsv = rb_entry(n, struct ext2_reserve_window_node, rsv_node);
+
+ if (goal < rsv->rsv_start)
+ n = n->rb_left;
+ else if (goal > rsv->rsv_end)
+ n = n->rb_right;
+ else
+ return rsv;
+ } while (n);
+ /*
+ * We've fallen off the end of the tree: the goal wasn't inside
+ * any particular node. OK, the previous node must be to one
+ * side of the interval containing the goal. If it's the RHS,
+ * we need to back up one.
+ */
+ if (rsv->rsv_start > goal) {
+ n = rb_prev(&rsv->rsv_node);
+ rsv = rb_entry(n, struct ext2_reserve_window_node, rsv_node);
+ }
+ return rsv;
+}
+
+/*
+ * ext2_rsv_window_add() -- Insert a window to the block reservation rb tree.
+ * @sb: super block
+ * @rsv: reservation window to add
+ *
+ * Must be called with rsv_lock held.
+ */
+void ext2_rsv_window_add(struct super_block *sb,
+ struct ext2_reserve_window_node *rsv)
+{
+ struct rb_root *root = &EXT2_SB(sb)->s_rsv_window_root;
+ struct rb_node *node = &rsv->rsv_node;
+ ext2_fsblk_t start = rsv->rsv_start;
+
+ struct rb_node ** p = &root->rb_node;
+ struct rb_node * parent = NULL;
+ struct ext2_reserve_window_node *this;
+
+ while (*p)
+ {
+ parent = *p;
+ this = rb_entry(parent, struct ext2_reserve_window_node, rsv_node);
+
+ if (start < this->rsv_start)
+ p = &(*p)->rb_left;
+ else if (start > this->rsv_end)
+ p = &(*p)->rb_right;
+ else {
+ rsv_window_dump(root, 1);
+ BUG();
+ }
+ }
+
+ rb_link_node(node, parent, p);
+ rb_insert_color(node, root);
+}
+
+/**
+ * rsv_window_remove() -- unlink a window from the reservation rb tree
+ * @sb: super block
+ * @rsv: reservation window to remove
+ *
+ * Mark the block reservation window as not allocated, and unlink it
+ * from the filesystem reservation window rb tree. Must be called with
+ * rsv_lock held.
+ */
+static void rsv_window_remove(struct super_block *sb,
+ struct ext2_reserve_window_node *rsv)
+{
+ rsv->rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
+ rsv->rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
+ rsv->rsv_alloc_hit = 0;
+ rb_erase(&rsv->rsv_node, &EXT2_SB(sb)->s_rsv_window_root);
+}
+
+/*
+ * rsv_is_empty() -- Check if the reservation window is allocated.
+ * @rsv: given reservation window to check
+ *
+ * returns 1 if the end block is EXT2_RESERVE_WINDOW_NOT_ALLOCATED.
+ */
+static inline int rsv_is_empty(struct ext2_reserve_window *rsv)
+{
+ /* a valid reservation end block could not be 0 */
+ return (rsv->_rsv_end == EXT2_RESERVE_WINDOW_NOT_ALLOCATED);
+}
+
+/**
+ * ext2_init_block_alloc_info()
+ * @inode: file inode structure
+ *
+ * Allocate and initialize the reservation window structure, and
+ * link the window to the ext2 inode structure at last
+ *
+ * The reservation window structure is only dynamically allocated
+ * and linked to ext2 inode the first time the open file
+ * needs a new block. So, before every ext2_new_block(s) call, for
+ * regular files, we should check whether the reservation window
+ * structure exists or not. In the latter case, this function is called.
+ * Fail to do so will result in block reservation being turned off for that
+ * open file.
+ *
+ * This function is called from ext2_get_blocks_handle(), also called
+ * when setting the reservation window size through ioctl before the file
+ * is open for write (needs block allocation).
+ *
+ * Needs truncate_mutex protection prior to calling this function.
+ */
+void ext2_init_block_alloc_info(struct inode *inode)
+{
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ struct ext2_block_alloc_info *block_i;
+ struct super_block *sb = inode->i_sb;
+
+ block_i = kmalloc(sizeof(*block_i), GFP_NOFS);
+ if (block_i) {
+ struct ext2_reserve_window_node *rsv = &block_i->rsv_window_node;
+
+ rsv->rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
+ rsv->rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
+
+ /*
+ * if filesystem is mounted with NORESERVATION, the goal
+ * reservation window size is set to zero to indicate
+ * block reservation is off
+ */
+ if (!test_opt(sb, RESERVATION))
+ rsv->rsv_goal_size = 0;
+ else
+ rsv->rsv_goal_size = EXT2_DEFAULT_RESERVE_BLOCKS;
+ rsv->rsv_alloc_hit = 0;
+ block_i->last_alloc_logical_block = 0;
+ block_i->last_alloc_physical_block = 0;
+ }
+ ei->i_block_alloc_info = block_i;
+}
+
+/**
+ * ext2_discard_reservation()
+ * @inode: inode
+ *
+ * Discard(free) block reservation window on last file close, or truncate
+ * or at last iput().
+ *
+ * It is being called in three cases:
+ * ext2_release_file(): last writer closes the file
+ * ext2_clear_inode(): last iput(), when nobody links to this file.
+ * ext2_truncate(): when the block indirect map is about to change.
+ */
+void ext2_discard_reservation(struct inode *inode)
+{
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ struct ext2_block_alloc_info *block_i = ei->i_block_alloc_info;
+ struct ext2_reserve_window_node *rsv;
+ spinlock_t *rsv_lock = &EXT2_SB(inode->i_sb)->s_rsv_window_lock;
+
+ if (!block_i)
+ return;
+
+ rsv = &block_i->rsv_window_node;
+ if (!rsv_is_empty(&rsv->rsv_window)) {
+ spin_lock(rsv_lock);
+ if (!rsv_is_empty(&rsv->rsv_window))
+ rsv_window_remove(inode->i_sb, rsv);
+ spin_unlock(rsv_lock);
+ }
+}
+
+/**
+ * ext2_free_blocks() -- Free given blocks and update quota and i_blocks
+ * @inode: inode
+ * @block: start physical block to free
+ * @count: number of blocks to free
+ */
+void ext2_free_blocks (struct inode * inode, unsigned long block,
+ unsigned long count)
+{
+ struct buffer_head *bitmap_bh = NULL;
+ struct buffer_head * bh2;
+ unsigned long block_group;
+ unsigned long bit;
+ unsigned long i;
+ unsigned long overflow;
+ struct super_block * sb = inode->i_sb;
+ struct ext2_sb_info * sbi = EXT2_SB(sb);
+ struct ext2_group_desc * desc;
+ struct ext2_super_block * es = sbi->s_es;
+ unsigned freed = 0, group_freed;
+
+ if (block < le32_to_cpu(es->s_first_data_block) ||
+ block + count < block ||
+ block + count > le32_to_cpu(es->s_blocks_count)) {
+ ext2_error (sb, "ext2_free_blocks",
+ "Freeing blocks not in datazone - "
+ "block = %lu, count = %lu", block, count);
+ goto error_return;
+ }
+
+ ext2_debug ("freeing block(s) %lu-%lu\n", block, block + count - 1);
+
+do_more:
+ overflow = 0;
+ block_group = (block - le32_to_cpu(es->s_first_data_block)) /
+ EXT2_BLOCKS_PER_GROUP(sb);
+ bit = (block - le32_to_cpu(es->s_first_data_block)) %
+ EXT2_BLOCKS_PER_GROUP(sb);
+ /*
+ * Check to see if we are freeing blocks across a group
+ * boundary.
+ */
+ if (bit + count > EXT2_BLOCKS_PER_GROUP(sb)) {
+ overflow = bit + count - EXT2_BLOCKS_PER_GROUP(sb);
+ count -= overflow;
+ }
+ brelse(bitmap_bh);
+ bitmap_bh = read_block_bitmap(sb, block_group);
+ if (!bitmap_bh)
+ goto error_return;
+
+ desc = ext2_get_group_desc (sb, block_group, &bh2);
+ if (!desc)
+ goto error_return;
+
+ if (in_range (le32_to_cpu(desc->bg_block_bitmap), block, count) ||
+ in_range (le32_to_cpu(desc->bg_inode_bitmap), block, count) ||
+ in_range (block, le32_to_cpu(desc->bg_inode_table),
+ sbi->s_itb_per_group) ||
+ in_range (block + count - 1, le32_to_cpu(desc->bg_inode_table),
+ sbi->s_itb_per_group)) {
+ ext2_error (sb, "ext2_free_blocks",
+ "Freeing blocks in system zones - "
+ "Block = %lu, count = %lu",
+ block, count);
+ goto error_return;
+ }
+
+ for (i = 0, group_freed = 0; i < count; i++) {
+ if (!ext2_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
+ bit + i, bitmap_bh->b_data)) {
+ ext2_error(sb, __func__,
+ "bit already cleared for block %lu", block + i);
+ } else {
+ group_freed++;
+ }
+ }
+
+ mark_buffer_dirty(bitmap_bh);
+ if (sb->s_flags & SB_SYNCHRONOUS)
+ sync_dirty_buffer(bitmap_bh);
+
+ group_adjust_blocks(sb, block_group, desc, bh2, group_freed);
+ freed += group_freed;
+
+ if (overflow) {
+ block += count;
+ count = overflow;
+ goto do_more;
+ }
+error_return:
+ brelse(bitmap_bh);
+ if (freed) {
+ percpu_counter_add(&sbi->s_freeblocks_counter, freed);
+ dquot_free_block_nodirty(inode, freed);
+ mark_inode_dirty(inode);
+ }
+}
+
+/**
+ * bitmap_search_next_usable_block()
+ * @start: the starting block (group relative) of the search
+ * @bh: bufferhead contains the block group bitmap
+ * @maxblocks: the ending block (group relative) of the reservation
+ *
+ * The bitmap search --- search forward through the actual bitmap on disk until
+ * we find a bit free.
+ */
+static ext2_grpblk_t
+bitmap_search_next_usable_block(ext2_grpblk_t start, struct buffer_head *bh,
+ ext2_grpblk_t maxblocks)
+{
+ ext2_grpblk_t next;
+
+ next = ext2_find_next_zero_bit(bh->b_data, maxblocks, start);
+ if (next >= maxblocks)
+ return -1;
+ return next;
+}
+
+/**
+ * find_next_usable_block()
+ * @start: the starting block (group relative) to find next
+ * allocatable block in bitmap.
+ * @bh: bufferhead contains the block group bitmap
+ * @maxblocks: the ending block (group relative) for the search
+ *
+ * Find an allocatable block in a bitmap. We perform the "most
+ * appropriate allocation" algorithm of looking for a free block near
+ * the initial goal; then for a free byte somewhere in the bitmap;
+ * then for any free bit in the bitmap.
+ */
+static ext2_grpblk_t
+find_next_usable_block(int start, struct buffer_head *bh, int maxblocks)
+{
+ ext2_grpblk_t here, next;
+ char *p, *r;
+
+ if (start > 0) {
+ /*
+ * The goal was occupied; search forward for a free
+ * block within the next XX blocks.
+ *
+ * end_goal is more or less random, but it has to be
+ * less than EXT2_BLOCKS_PER_GROUP. Aligning up to the
+ * next 64-bit boundary is simple..
+ */
+ ext2_grpblk_t end_goal = (start + 63) & ~63;
+ if (end_goal > maxblocks)
+ end_goal = maxblocks;
+ here = ext2_find_next_zero_bit(bh->b_data, end_goal, start);
+ if (here < end_goal)
+ return here;
+ ext2_debug("Bit not found near goal\n");
+ }
+
+ here = start;
+ if (here < 0)
+ here = 0;
+
+ p = ((char *)bh->b_data) + (here >> 3);
+ r = memscan(p, 0, ((maxblocks + 7) >> 3) - (here >> 3));
+ next = (r - ((char *)bh->b_data)) << 3;
+
+ if (next < maxblocks && next >= here)
+ return next;
+
+ here = bitmap_search_next_usable_block(here, bh, maxblocks);
+ return here;
+}
+
+/**
+ * ext2_try_to_allocate()
+ * @sb: superblock
+ * @group: given allocation block group
+ * @bitmap_bh: bufferhead holds the block bitmap
+ * @grp_goal: given target block within the group
+ * @count: target number of blocks to allocate
+ * @my_rsv: reservation window
+ *
+ * Attempt to allocate blocks within a give range. Set the range of allocation
+ * first, then find the first free bit(s) from the bitmap (within the range),
+ * and at last, allocate the blocks by claiming the found free bit as allocated.
+ *
+ * To set the range of this allocation:
+ * if there is a reservation window, only try to allocate block(s)
+ * from the file's own reservation window;
+ * Otherwise, the allocation range starts from the give goal block,
+ * ends at the block group's last block.
+ *
+ * If we failed to allocate the desired block then we may end up crossing to a
+ * new bitmap.
+ */
+static int
+ext2_try_to_allocate(struct super_block *sb, int group,
+ struct buffer_head *bitmap_bh, ext2_grpblk_t grp_goal,
+ unsigned long *count,
+ struct ext2_reserve_window *my_rsv)
+{
+ ext2_fsblk_t group_first_block;
+ ext2_grpblk_t start, end;
+ unsigned long num = 0;
+
+ /* we do allocation within the reservation window if we have a window */
+ if (my_rsv) {
+ group_first_block = ext2_group_first_block_no(sb, group);
+ if (my_rsv->_rsv_start >= group_first_block)
+ start = my_rsv->_rsv_start - group_first_block;
+ else
+ /* reservation window cross group boundary */
+ start = 0;
+ end = my_rsv->_rsv_end - group_first_block + 1;
+ if (end > EXT2_BLOCKS_PER_GROUP(sb))
+ /* reservation window crosses group boundary */
+ end = EXT2_BLOCKS_PER_GROUP(sb);
+ if ((start <= grp_goal) && (grp_goal < end))
+ start = grp_goal;
+ else
+ grp_goal = -1;
+ } else {
+ if (grp_goal > 0)
+ start = grp_goal;
+ else
+ start = 0;
+ end = EXT2_BLOCKS_PER_GROUP(sb);
+ }
+
+ BUG_ON(start > EXT2_BLOCKS_PER_GROUP(sb));
+
+repeat:
+ if (grp_goal < 0) {
+ grp_goal = find_next_usable_block(start, bitmap_bh, end);
+ if (grp_goal < 0)
+ goto fail_access;
+ if (!my_rsv) {
+ int i;
+
+ for (i = 0; i < 7 && grp_goal > start &&
+ !ext2_test_bit(grp_goal - 1,
+ bitmap_bh->b_data);
+ i++, grp_goal--)
+ ;
+ }
+ }
+ start = grp_goal;
+
+ if (ext2_set_bit_atomic(sb_bgl_lock(EXT2_SB(sb), group), grp_goal,
+ bitmap_bh->b_data)) {
+ /*
+ * The block was allocated by another thread, or it was
+ * allocated and then freed by another thread
+ */
+ start++;
+ grp_goal++;
+ if (start >= end)
+ goto fail_access;
+ goto repeat;
+ }
+ num++;
+ grp_goal++;
+ while (num < *count && grp_goal < end
+ && !ext2_set_bit_atomic(sb_bgl_lock(EXT2_SB(sb), group),
+ grp_goal, bitmap_bh->b_data)) {
+ num++;
+ grp_goal++;
+ }
+ *count = num;
+ return grp_goal - num;
+fail_access:
+ *count = num;
+ return -1;
+}
+
+/**
+ * find_next_reservable_window():
+ * find a reservable space within the given range.
+ * It does not allocate the reservation window for now:
+ * alloc_new_reservation() will do the work later.
+ *
+ * @search_head: the head of the searching list;
+ * This is not necessarily the list head of the whole filesystem
+ *
+ * We have both head and start_block to assist the search
+ * for the reservable space. The list starts from head,
+ * but we will shift to the place where start_block is,
+ * then start from there, when looking for a reservable space.
+ *
+ * @size: the target new reservation window size
+ *
+ * @group_first_block: the first block we consider to start
+ * the real search from
+ *
+ * @last_block:
+ * the maximum block number that our goal reservable space
+ * could start from. This is normally the last block in this
+ * group. The search will end when we found the start of next
+ * possible reservable space is out of this boundary.
+ * This could handle the cross boundary reservation window
+ * request.
+ *
+ * basically we search from the given range, rather than the whole
+ * reservation double linked list, (start_block, last_block)
+ * to find a free region that is of my size and has not
+ * been reserved.
+ *
+ */
+static int find_next_reservable_window(
+ struct ext2_reserve_window_node *search_head,
+ struct ext2_reserve_window_node *my_rsv,
+ struct super_block * sb,
+ ext2_fsblk_t start_block,
+ ext2_fsblk_t last_block)
+{
+ struct rb_node *next;
+ struct ext2_reserve_window_node *rsv, *prev;
+ ext2_fsblk_t cur;
+ int size = my_rsv->rsv_goal_size;
+
+ /* TODO: make the start of the reservation window byte-aligned */
+ /* cur = *start_block & ~7;*/
+ cur = start_block;
+ rsv = search_head;
+ if (!rsv)
+ return -1;
+
+ while (1) {
+ if (cur <= rsv->rsv_end)
+ cur = rsv->rsv_end + 1;
+
+ /* TODO?
+ * in the case we could not find a reservable space
+ * that is what is expected, during the re-search, we could
+ * remember what's the largest reservable space we could have
+ * and return that one.
+ *
+ * For now it will fail if we could not find the reservable
+ * space with expected-size (or more)...
+ */
+ if (cur > last_block)
+ return -1; /* fail */
+
+ prev = rsv;
+ next = rb_next(&rsv->rsv_node);
+ rsv = rb_entry(next,struct ext2_reserve_window_node,rsv_node);
+
+ /*
+ * Reached the last reservation, we can just append to the
+ * previous one.
+ */
+ if (!next)
+ break;
+
+ if (cur + size <= rsv->rsv_start) {
+ /*
+ * Found a reserveable space big enough. We could
+ * have a reservation across the group boundary here
+ */
+ break;
+ }
+ }
+ /*
+ * we come here either :
+ * when we reach the end of the whole list,
+ * and there is empty reservable space after last entry in the list.
+ * append it to the end of the list.
+ *
+ * or we found one reservable space in the middle of the list,
+ * return the reservation window that we could append to.
+ * succeed.
+ */
+
+ if ((prev != my_rsv) && (!rsv_is_empty(&my_rsv->rsv_window)))
+ rsv_window_remove(sb, my_rsv);
+
+ /*
+ * Let's book the whole available window for now. We will check the
+ * disk bitmap later and then, if there are free blocks then we adjust
+ * the window size if it's larger than requested.
+ * Otherwise, we will remove this node from the tree next time
+ * call find_next_reservable_window.
+ */
+ my_rsv->rsv_start = cur;
+ my_rsv->rsv_end = cur + size - 1;
+ my_rsv->rsv_alloc_hit = 0;
+
+ if (prev != my_rsv)
+ ext2_rsv_window_add(sb, my_rsv);
+
+ return 0;
+}
+
+/**
+ * alloc_new_reservation()--allocate a new reservation window
+ *
+ * To make a new reservation, we search part of the filesystem
+ * reservation list (the list that inside the group). We try to
+ * allocate a new reservation window near the allocation goal,
+ * or the beginning of the group, if there is no goal.
+ *
+ * We first find a reservable space after the goal, then from
+ * there, we check the bitmap for the first free block after
+ * it. If there is no free block until the end of group, then the
+ * whole group is full, we failed. Otherwise, check if the free
+ * block is inside the expected reservable space, if so, we
+ * succeed.
+ * If the first free block is outside the reservable space, then
+ * start from the first free block, we search for next available
+ * space, and go on.
+ *
+ * on succeed, a new reservation will be found and inserted into the list
+ * It contains at least one free block, and it does not overlap with other
+ * reservation windows.
+ *
+ * failed: we failed to find a reservation window in this group
+ *
+ * @rsv: the reservation
+ *
+ * @grp_goal: The goal (group-relative). It is where the search for a
+ * free reservable space should start from.
+ * if we have a goal(goal >0 ), then start from there,
+ * no goal(goal = -1), we start from the first block
+ * of the group.
+ *
+ * @sb: the super block
+ * @group: the group we are trying to allocate in
+ * @bitmap_bh: the block group block bitmap
+ *
+ */
+static int alloc_new_reservation(struct ext2_reserve_window_node *my_rsv,
+ ext2_grpblk_t grp_goal, struct super_block *sb,
+ unsigned int group, struct buffer_head *bitmap_bh)
+{
+ struct ext2_reserve_window_node *search_head;
+ ext2_fsblk_t group_first_block, group_end_block, start_block;
+ ext2_grpblk_t first_free_block;
+ struct rb_root *fs_rsv_root = &EXT2_SB(sb)->s_rsv_window_root;
+ unsigned long size;
+ int ret;
+ spinlock_t *rsv_lock = &EXT2_SB(sb)->s_rsv_window_lock;
+
+ group_first_block = ext2_group_first_block_no(sb, group);
+ group_end_block = group_first_block + (EXT2_BLOCKS_PER_GROUP(sb) - 1);
+
+ if (grp_goal < 0)
+ start_block = group_first_block;
+ else
+ start_block = grp_goal + group_first_block;
+
+ size = my_rsv->rsv_goal_size;
+
+ if (!rsv_is_empty(&my_rsv->rsv_window)) {
+ /*
+ * if the old reservation is cross group boundary
+ * and if the goal is inside the old reservation window,
+ * we will come here when we just failed to allocate from
+ * the first part of the window. We still have another part
+ * that belongs to the next group. In this case, there is no
+ * point to discard our window and try to allocate a new one
+ * in this group(which will fail). we should
+ * keep the reservation window, just simply move on.
+ *
+ * Maybe we could shift the start block of the reservation
+ * window to the first block of next group.
+ */
+
+ if ((my_rsv->rsv_start <= group_end_block) &&
+ (my_rsv->rsv_end > group_end_block) &&
+ (start_block >= my_rsv->rsv_start))
+ return -1;
+
+ if ((my_rsv->rsv_alloc_hit >
+ (my_rsv->rsv_end - my_rsv->rsv_start + 1) / 2)) {
+ /*
+ * if the previously allocation hit ratio is
+ * greater than 1/2, then we double the size of
+ * the reservation window the next time,
+ * otherwise we keep the same size window
+ */
+ size = size * 2;
+ if (size > EXT2_MAX_RESERVE_BLOCKS)
+ size = EXT2_MAX_RESERVE_BLOCKS;
+ my_rsv->rsv_goal_size= size;
+ }
+ }
+
+ spin_lock(rsv_lock);
+ /*
+ * shift the search start to the window near the goal block
+ */
+ search_head = search_reserve_window(fs_rsv_root, start_block);
+
+ /*
+ * find_next_reservable_window() simply finds a reservable window
+ * inside the given range(start_block, group_end_block).
+ *
+ * To make sure the reservation window has a free bit inside it, we
+ * need to check the bitmap after we found a reservable window.
+ */
+retry:
+ ret = find_next_reservable_window(search_head, my_rsv, sb,
+ start_block, group_end_block);
+
+ if (ret == -1) {
+ if (!rsv_is_empty(&my_rsv->rsv_window))
+ rsv_window_remove(sb, my_rsv);
+ spin_unlock(rsv_lock);
+ return -1;
+ }
+
+ /*
+ * On success, find_next_reservable_window() returns the
+ * reservation window where there is a reservable space after it.
+ * Before we reserve this reservable space, we need
+ * to make sure there is at least a free block inside this region.
+ *
+ * Search the first free bit on the block bitmap. Search starts from
+ * the start block of the reservable space we just found.
+ */
+ spin_unlock(rsv_lock);
+ first_free_block = bitmap_search_next_usable_block(
+ my_rsv->rsv_start - group_first_block,
+ bitmap_bh, group_end_block - group_first_block + 1);
+
+ if (first_free_block < 0) {
+ /*
+ * no free block left on the bitmap, no point
+ * to reserve the space. return failed.
+ */
+ spin_lock(rsv_lock);
+ if (!rsv_is_empty(&my_rsv->rsv_window))
+ rsv_window_remove(sb, my_rsv);
+ spin_unlock(rsv_lock);
+ return -1; /* failed */
+ }
+
+ start_block = first_free_block + group_first_block;
+ /*
+ * check if the first free block is within the
+ * free space we just reserved
+ */
+ if (start_block >= my_rsv->rsv_start && start_block <= my_rsv->rsv_end)
+ return 0; /* success */
+ /*
+ * if the first free bit we found is out of the reservable space
+ * continue search for next reservable space,
+ * start from where the free block is,
+ * we also shift the list head to where we stopped last time
+ */
+ search_head = my_rsv;
+ spin_lock(rsv_lock);
+ goto retry;
+}
+
+/**
+ * try_to_extend_reservation()
+ * @my_rsv: given reservation window
+ * @sb: super block
+ * @size: the delta to extend
+ *
+ * Attempt to expand the reservation window large enough to have
+ * required number of free blocks
+ *
+ * Since ext2_try_to_allocate() will always allocate blocks within
+ * the reservation window range, if the window size is too small,
+ * multiple blocks allocation has to stop at the end of the reservation
+ * window. To make this more efficient, given the total number of
+ * blocks needed and the current size of the window, we try to
+ * expand the reservation window size if necessary on a best-effort
+ * basis before ext2_new_blocks() tries to allocate blocks.
+ */
+static void try_to_extend_reservation(struct ext2_reserve_window_node *my_rsv,
+ struct super_block *sb, int size)
+{
+ struct ext2_reserve_window_node *next_rsv;
+ struct rb_node *next;
+ spinlock_t *rsv_lock = &EXT2_SB(sb)->s_rsv_window_lock;
+
+ if (!spin_trylock(rsv_lock))
+ return;
+
+ next = rb_next(&my_rsv->rsv_node);
+
+ if (!next)
+ my_rsv->rsv_end += size;
+ else {
+ next_rsv = rb_entry(next, struct ext2_reserve_window_node, rsv_node);
+
+ if ((next_rsv->rsv_start - my_rsv->rsv_end - 1) >= size)
+ my_rsv->rsv_end += size;
+ else
+ my_rsv->rsv_end = next_rsv->rsv_start - 1;
+ }
+ spin_unlock(rsv_lock);
+}
+
+/**
+ * ext2_try_to_allocate_with_rsv()
+ * @sb: superblock
+ * @group: given allocation block group
+ * @bitmap_bh: bufferhead holds the block bitmap
+ * @grp_goal: given target block within the group
+ * @count: target number of blocks to allocate
+ * @my_rsv: reservation window
+ *
+ * This is the main function used to allocate a new block and its reservation
+ * window.
+ *
+ * Each time when a new block allocation is need, first try to allocate from
+ * its own reservation. If it does not have a reservation window, instead of
+ * looking for a free bit on bitmap first, then look up the reservation list to
+ * see if it is inside somebody else's reservation window, we try to allocate a
+ * reservation window for it starting from the goal first. Then do the block
+ * allocation within the reservation window.
+ *
+ * This will avoid keeping on searching the reservation list again and
+ * again when somebody is looking for a free block (without
+ * reservation), and there are lots of free blocks, but they are all
+ * being reserved.
+ *
+ * We use a red-black tree for the per-filesystem reservation list.
+ */
+static ext2_grpblk_t
+ext2_try_to_allocate_with_rsv(struct super_block *sb, unsigned int group,
+ struct buffer_head *bitmap_bh, ext2_grpblk_t grp_goal,
+ struct ext2_reserve_window_node * my_rsv,
+ unsigned long *count)
+{
+ ext2_fsblk_t group_first_block, group_last_block;
+ ext2_grpblk_t ret = 0;
+ unsigned long num = *count;
+
+ /*
+ * we don't deal with reservation when
+ * filesystem is mounted without reservation
+ * or the file is not a regular file
+ * or last attempt to allocate a block with reservation turned on failed
+ */
+ if (my_rsv == NULL) {
+ return ext2_try_to_allocate(sb, group, bitmap_bh,
+ grp_goal, count, NULL);
+ }
+ /*
+ * grp_goal is a group relative block number (if there is a goal)
+ * 0 <= grp_goal < EXT2_BLOCKS_PER_GROUP(sb)
+ * first block is a filesystem wide block number
+ * first block is the block number of the first block in this group
+ */
+ group_first_block = ext2_group_first_block_no(sb, group);
+ group_last_block = group_first_block + (EXT2_BLOCKS_PER_GROUP(sb) - 1);
+
+ /*
+ * Basically we will allocate a new block from inode's reservation
+ * window.
+ *
+ * We need to allocate a new reservation window, if:
+ * a) inode does not have a reservation window; or
+ * b) last attempt to allocate a block from existing reservation
+ * failed; or
+ * c) we come here with a goal and with a reservation window
+ *
+ * We do not need to allocate a new reservation window if we come here
+ * at the beginning with a goal and the goal is inside the window, or
+ * we don't have a goal but already have a reservation window.
+ * then we could go to allocate from the reservation window directly.
+ */
+ while (1) {
+ if (rsv_is_empty(&my_rsv->rsv_window) || (ret < 0) ||
+ !goal_in_my_reservation(&my_rsv->rsv_window,
+ grp_goal, group, sb)) {
+ if (my_rsv->rsv_goal_size < *count)
+ my_rsv->rsv_goal_size = *count;
+ ret = alloc_new_reservation(my_rsv, grp_goal, sb,
+ group, bitmap_bh);
+ if (ret < 0)
+ break; /* failed */
+
+ if (!goal_in_my_reservation(&my_rsv->rsv_window,
+ grp_goal, group, sb))
+ grp_goal = -1;
+ } else if (grp_goal >= 0) {
+ int curr = my_rsv->rsv_end -
+ (grp_goal + group_first_block) + 1;
+
+ if (curr < *count)
+ try_to_extend_reservation(my_rsv, sb,
+ *count - curr);
+ }
+
+ if ((my_rsv->rsv_start > group_last_block) ||
+ (my_rsv->rsv_end < group_first_block)) {
+ rsv_window_dump(&EXT2_SB(sb)->s_rsv_window_root, 1);
+ BUG();
+ }
+ ret = ext2_try_to_allocate(sb, group, bitmap_bh, grp_goal,
+ &num, &my_rsv->rsv_window);
+ if (ret >= 0) {
+ my_rsv->rsv_alloc_hit += num;
+ *count = num;
+ break; /* succeed */
+ }
+ num = *count;
+ }
+ return ret;
+}
+
+/**
+ * ext2_has_free_blocks()
+ * @sbi: in-core super block structure.
+ *
+ * Check if filesystem has at least 1 free block available for allocation.
+ */
+static int ext2_has_free_blocks(struct ext2_sb_info *sbi)
+{
+ ext2_fsblk_t free_blocks, root_blocks;
+
+ free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
+ root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count);
+ if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) &&
+ !uid_eq(sbi->s_resuid, current_fsuid()) &&
+ (gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) ||
+ !in_group_p (sbi->s_resgid))) {
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * Returns 1 if the passed-in block region is valid; 0 if some part overlaps
+ * with filesystem metadata blocksi.
+ */
+int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk,
+ unsigned int count)
+{
+ if ((start_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
+ (start_blk + count < start_blk) ||
+ (start_blk > le32_to_cpu(sbi->s_es->s_blocks_count)))
+ return 0;
+
+ /* Ensure we do not step over superblock */
+ if ((start_blk <= sbi->s_sb_block) &&
+ (start_blk + count >= sbi->s_sb_block))
+ return 0;
+
+
+ return 1;
+}
+
+/*
+ * ext2_new_blocks() -- core block(s) allocation function
+ * @inode: file inode
+ * @goal: given target block(filesystem wide)
+ * @count: target number of blocks to allocate
+ * @errp: error code
+ *
+ * ext2_new_blocks uses a goal block to assist allocation. If the goal is
+ * free, or there is a free block within 32 blocks of the goal, that block
+ * is allocated. Otherwise a forward search is made for a free block; within
+ * each block group the search first looks for an entire free byte in the block
+ * bitmap, and then for any free bit if that fails.
+ * This function also updates quota and i_blocks field.
+ */
+ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal,
+ unsigned long *count, int *errp)
+{
+ struct buffer_head *bitmap_bh = NULL;
+ struct buffer_head *gdp_bh;
+ int group_no;
+ int goal_group;
+ ext2_grpblk_t grp_target_blk; /* blockgroup relative goal block */
+ ext2_grpblk_t grp_alloc_blk; /* blockgroup-relative allocated block*/
+ ext2_fsblk_t ret_block; /* filesyetem-wide allocated block */
+ int bgi; /* blockgroup iteration index */
+ int performed_allocation = 0;
+ ext2_grpblk_t free_blocks; /* number of free blocks in a group */
+ struct super_block *sb;
+ struct ext2_group_desc *gdp;
+ struct ext2_super_block *es;
+ struct ext2_sb_info *sbi;
+ struct ext2_reserve_window_node *my_rsv = NULL;
+ struct ext2_block_alloc_info *block_i;
+ unsigned short windowsz = 0;
+ unsigned long ngroups;
+ unsigned long num = *count;
+ int ret;
+
+ *errp = -ENOSPC;
+ sb = inode->i_sb;
+
+ /*
+ * Check quota for allocation of this block.
+ */
+ ret = dquot_alloc_block(inode, num);
+ if (ret) {
+ *errp = ret;
+ return 0;
+ }
+
+ sbi = EXT2_SB(sb);
+ es = EXT2_SB(sb)->s_es;
+ ext2_debug("goal=%lu.\n", goal);
+ /*
+ * Allocate a block from reservation only when
+ * filesystem is mounted with reservation(default,-o reservation), and
+ * it's a regular file, and
+ * the desired window size is greater than 0 (One could use ioctl
+ * command EXT2_IOC_SETRSVSZ to set the window size to 0 to turn off
+ * reservation on that particular file)
+ */
+ block_i = EXT2_I(inode)->i_block_alloc_info;
+ if (block_i) {
+ windowsz = block_i->rsv_window_node.rsv_goal_size;
+ if (windowsz > 0)
+ my_rsv = &block_i->rsv_window_node;
+ }
+
+ if (!ext2_has_free_blocks(sbi)) {
+ *errp = -ENOSPC;
+ goto out;
+ }
+
+ /*
+ * First, test whether the goal block is free.
+ */
+ if (goal < le32_to_cpu(es->s_first_data_block) ||
+ goal >= le32_to_cpu(es->s_blocks_count))
+ goal = le32_to_cpu(es->s_first_data_block);
+ group_no = (goal - le32_to_cpu(es->s_first_data_block)) /
+ EXT2_BLOCKS_PER_GROUP(sb);
+ goal_group = group_no;
+retry_alloc:
+ gdp = ext2_get_group_desc(sb, group_no, &gdp_bh);
+ if (!gdp)
+ goto io_error;
+
+ free_blocks = le16_to_cpu(gdp->bg_free_blocks_count);
+ /*
+ * if there is not enough free blocks to make a new resevation
+ * turn off reservation for this allocation
+ */
+ if (my_rsv && (free_blocks < windowsz)
+ && (free_blocks > 0)
+ && (rsv_is_empty(&my_rsv->rsv_window)))
+ my_rsv = NULL;
+
+ if (free_blocks > 0) {
+ grp_target_blk = ((goal - le32_to_cpu(es->s_first_data_block)) %
+ EXT2_BLOCKS_PER_GROUP(sb));
+ bitmap_bh = read_block_bitmap(sb, group_no);
+ if (!bitmap_bh)
+ goto io_error;
+ grp_alloc_blk = ext2_try_to_allocate_with_rsv(sb, group_no,
+ bitmap_bh, grp_target_blk,
+ my_rsv, &num);
+ if (grp_alloc_blk >= 0)
+ goto allocated;
+ }
+
+ ngroups = EXT2_SB(sb)->s_groups_count;
+ smp_rmb();
+
+ /*
+ * Now search the rest of the groups. We assume that
+ * group_no and gdp correctly point to the last group visited.
+ */
+ for (bgi = 0; bgi < ngroups; bgi++) {
+ group_no++;
+ if (group_no >= ngroups)
+ group_no = 0;
+ gdp = ext2_get_group_desc(sb, group_no, &gdp_bh);
+ if (!gdp)
+ goto io_error;
+
+ free_blocks = le16_to_cpu(gdp->bg_free_blocks_count);
+ /*
+ * skip this group (and avoid loading bitmap) if there
+ * are no free blocks
+ */
+ if (!free_blocks)
+ continue;
+ /*
+ * skip this group if the number of
+ * free blocks is less than half of the reservation
+ * window size.
+ */
+ if (my_rsv && (free_blocks <= (windowsz/2)))
+ continue;
+
+ brelse(bitmap_bh);
+ bitmap_bh = read_block_bitmap(sb, group_no);
+ if (!bitmap_bh)
+ goto io_error;
+ /*
+ * try to allocate block(s) from this group, without a goal(-1).
+ */
+ grp_alloc_blk = ext2_try_to_allocate_with_rsv(sb, group_no,
+ bitmap_bh, -1, my_rsv, &num);
+ if (grp_alloc_blk >= 0)
+ goto allocated;
+ }
+ /*
+ * We may end up a bogus earlier ENOSPC error due to
+ * filesystem is "full" of reservations, but
+ * there maybe indeed free blocks available on disk
+ * In this case, we just forget about the reservations
+ * just do block allocation as without reservations.
+ */
+ if (my_rsv) {
+ my_rsv = NULL;
+ windowsz = 0;
+ group_no = goal_group;
+ goto retry_alloc;
+ }
+ /* No space left on the device */
+ *errp = -ENOSPC;
+ goto out;
+
+allocated:
+
+ ext2_debug("using block group %d(%d)\n",
+ group_no, gdp->bg_free_blocks_count);
+
+ ret_block = grp_alloc_blk + ext2_group_first_block_no(sb, group_no);
+
+ if (in_range(le32_to_cpu(gdp->bg_block_bitmap), ret_block, num) ||
+ in_range(le32_to_cpu(gdp->bg_inode_bitmap), ret_block, num) ||
+ in_range(ret_block, le32_to_cpu(gdp->bg_inode_table),
+ EXT2_SB(sb)->s_itb_per_group) ||
+ in_range(ret_block + num - 1, le32_to_cpu(gdp->bg_inode_table),
+ EXT2_SB(sb)->s_itb_per_group)) {
+ ext2_error(sb, "ext2_new_blocks",
+ "Allocating block in system zone - "
+ "blocks from "E2FSBLK", length %lu",
+ ret_block, num);
+ /*
+ * ext2_try_to_allocate marked the blocks we allocated as in
+ * use. So we may want to selectively mark some of the blocks
+ * as free
+ */
+ goto retry_alloc;
+ }
+
+ performed_allocation = 1;
+
+ if (ret_block + num - 1 >= le32_to_cpu(es->s_blocks_count)) {
+ ext2_error(sb, "ext2_new_blocks",
+ "block("E2FSBLK") >= blocks count(%d) - "
+ "block_group = %d, es == %p ", ret_block,
+ le32_to_cpu(es->s_blocks_count), group_no, es);
+ goto out;
+ }
+
+ group_adjust_blocks(sb, group_no, gdp, gdp_bh, -num);
+ percpu_counter_sub(&sbi->s_freeblocks_counter, num);
+
+ mark_buffer_dirty(bitmap_bh);
+ if (sb->s_flags & SB_SYNCHRONOUS)
+ sync_dirty_buffer(bitmap_bh);
+
+ *errp = 0;
+ brelse(bitmap_bh);
+ if (num < *count) {
+ dquot_free_block_nodirty(inode, *count-num);
+ mark_inode_dirty(inode);
+ *count = num;
+ }
+ return ret_block;
+
+io_error:
+ *errp = -EIO;
+out:
+ /*
+ * Undo the block allocation
+ */
+ if (!performed_allocation) {
+ dquot_free_block_nodirty(inode, *count);
+ mark_inode_dirty(inode);
+ }
+ brelse(bitmap_bh);
+ return 0;
+}
+
+ext2_fsblk_t ext2_new_block(struct inode *inode, unsigned long goal, int *errp)
+{
+ unsigned long count = 1;
+
+ return ext2_new_blocks(inode, goal, &count, errp);
+}
+
+#ifdef EXT2FS_DEBUG
+
+unsigned long ext2_count_free(struct buffer_head *map, unsigned int numchars)
+{
+ return numchars * BITS_PER_BYTE - memweight(map->b_data, numchars);
+}
+
+#endif /* EXT2FS_DEBUG */
+
+unsigned long ext2_count_free_blocks (struct super_block * sb)
+{
+ struct ext2_group_desc * desc;
+ unsigned long desc_count = 0;
+ int i;
+#ifdef EXT2FS_DEBUG
+ unsigned long bitmap_count, x;
+ struct ext2_super_block *es;
+
+ es = EXT2_SB(sb)->s_es;
+ desc_count = 0;
+ bitmap_count = 0;
+ desc = NULL;
+ for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
+ struct buffer_head *bitmap_bh;
+ desc = ext2_get_group_desc (sb, i, NULL);
+ if (!desc)
+ continue;
+ desc_count += le16_to_cpu(desc->bg_free_blocks_count);
+ bitmap_bh = read_block_bitmap(sb, i);
+ if (!bitmap_bh)
+ continue;
+
+ x = ext2_count_free(bitmap_bh, sb->s_blocksize);
+ printk ("group %d: stored = %d, counted = %lu\n",
+ i, le16_to_cpu(desc->bg_free_blocks_count), x);
+ bitmap_count += x;
+ brelse(bitmap_bh);
+ }
+ printk("ext2_count_free_blocks: stored = %lu, computed = %lu, %lu\n",
+ (long)le32_to_cpu(es->s_free_blocks_count),
+ desc_count, bitmap_count);
+ return bitmap_count;
+#else
+ for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
+ desc = ext2_get_group_desc (sb, i, NULL);
+ if (!desc)
+ continue;
+ desc_count += le16_to_cpu(desc->bg_free_blocks_count);
+ }
+ return desc_count;
+#endif
+}
+
+static inline int test_root(int a, int b)
+{
+ int num = b;
+
+ while (a > num)
+ num *= b;
+ return num == a;
+}
+
+static int ext2_group_sparse(int group)
+{
+ if (group <= 1)
+ return 1;
+ return (test_root(group, 3) || test_root(group, 5) ||
+ test_root(group, 7));
+}
+
+/**
+ * ext2_bg_has_super - number of blocks used by the superblock in group
+ * @sb: superblock for filesystem
+ * @group: group number to check
+ *
+ * Return the number of blocks used by the superblock (primary or backup)
+ * in this group. Currently this will be only 0 or 1.
+ */
+int ext2_bg_has_super(struct super_block *sb, int group)
+{
+ if (EXT2_HAS_RO_COMPAT_FEATURE(sb,EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)&&
+ !ext2_group_sparse(group))
+ return 0;
+ return 1;
+}
+
+/**
+ * ext2_bg_num_gdb - number of blocks used by the group table in group
+ * @sb: superblock for filesystem
+ * @group: group number to check
+ *
+ * Return the number of blocks used by the group descriptor table
+ * (primary or backup) in this group. In the future there may be a
+ * different number of descriptor blocks in each group.
+ */
+unsigned long ext2_bg_num_gdb(struct super_block *sb, int group)
+{
+ return ext2_bg_has_super(sb, group) ? EXT2_SB(sb)->s_gdb_count : 0;
+}
+
diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
new file mode 100644
index 0000000..3b8114d
--- /dev/null
+++ b/fs/ext2/dir.c
@@ -0,0 +1,727 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/dir.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * from
+ *
+ * linux/fs/minix/dir.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * ext2 directory handling functions
+ *
+ * Big-endian to little-endian byte-swapping/bitmaps by
+ * David S. Miller (davem@caip.rutgers.edu), 1995
+ *
+ * All code that works with directory layout had been switched to pagecache
+ * and moved here. AV
+ */
+
+#include "ext2.h"
+#include <linux/buffer_head.h>
+#include <linux/pagemap.h>
+#include <linux/swap.h>
+#include <linux/iversion.h>
+
+typedef struct ext2_dir_entry_2 ext2_dirent;
+
+/*
+ * Tests against MAX_REC_LEN etc were put in place for 64k block
+ * sizes; if that is not possible on this arch, we can skip
+ * those tests and speed things up.
+ */
+static inline unsigned ext2_rec_len_from_disk(__le16 dlen)
+{
+ unsigned len = le16_to_cpu(dlen);
+
+#if (PAGE_SIZE >= 65536)
+ if (len == EXT2_MAX_REC_LEN)
+ return 1 << 16;
+#endif
+ return len;
+}
+
+static inline __le16 ext2_rec_len_to_disk(unsigned len)
+{
+#if (PAGE_SIZE >= 65536)
+ if (len == (1 << 16))
+ return cpu_to_le16(EXT2_MAX_REC_LEN);
+ else
+ BUG_ON(len > (1 << 16));
+#endif
+ return cpu_to_le16(len);
+}
+
+/*
+ * ext2 uses block-sized chunks. Arguably, sector-sized ones would be
+ * more robust, but we have what we have
+ */
+static inline unsigned ext2_chunk_size(struct inode *inode)
+{
+ return inode->i_sb->s_blocksize;
+}
+
+static inline void ext2_put_page(struct page *page)
+{
+ kunmap(page);
+ put_page(page);
+}
+
+/*
+ * Return the offset into page `page_nr' of the last valid
+ * byte in that page, plus one.
+ */
+static unsigned
+ext2_last_byte(struct inode *inode, unsigned long page_nr)
+{
+ unsigned last_byte = inode->i_size;
+
+ last_byte -= page_nr << PAGE_SHIFT;
+ if (last_byte > PAGE_SIZE)
+ last_byte = PAGE_SIZE;
+ return last_byte;
+}
+
+static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len)
+{
+ struct address_space *mapping = page->mapping;
+ struct inode *dir = mapping->host;
+ int err = 0;
+
+ inode_inc_iversion(dir);
+ block_write_end(NULL, mapping, pos, len, len, page, NULL);
+
+ if (pos+len > dir->i_size) {
+ i_size_write(dir, pos+len);
+ mark_inode_dirty(dir);
+ }
+
+ if (IS_DIRSYNC(dir)) {
+ err = write_one_page(page);
+ if (!err)
+ err = sync_inode_metadata(dir, 1);
+ } else {
+ unlock_page(page);
+ }
+
+ return err;
+}
+
+static bool ext2_check_page(struct page *page, int quiet)
+{
+ struct inode *dir = page->mapping->host;
+ struct super_block *sb = dir->i_sb;
+ unsigned chunk_size = ext2_chunk_size(dir);
+ char *kaddr = page_address(page);
+ u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count);
+ unsigned offs, rec_len;
+ unsigned limit = PAGE_SIZE;
+ ext2_dirent *p;
+ char *error;
+
+ if ((dir->i_size >> PAGE_SHIFT) == page->index) {
+ limit = dir->i_size & ~PAGE_MASK;
+ if (limit & (chunk_size - 1))
+ goto Ebadsize;
+ if (!limit)
+ goto out;
+ }
+ for (offs = 0; offs <= limit - EXT2_DIR_REC_LEN(1); offs += rec_len) {
+ p = (ext2_dirent *)(kaddr + offs);
+ rec_len = ext2_rec_len_from_disk(p->rec_len);
+
+ if (unlikely(rec_len < EXT2_DIR_REC_LEN(1)))
+ goto Eshort;
+ if (unlikely(rec_len & 3))
+ goto Ealign;
+ if (unlikely(rec_len < EXT2_DIR_REC_LEN(p->name_len)))
+ goto Enamelen;
+ if (unlikely(((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)))
+ goto Espan;
+ if (unlikely(le32_to_cpu(p->inode) > max_inumber))
+ goto Einumber;
+ }
+ if (offs != limit)
+ goto Eend;
+out:
+ SetPageChecked(page);
+ return true;
+
+ /* Too bad, we had an error */
+
+Ebadsize:
+ if (!quiet)
+ ext2_error(sb, __func__,
+ "size of directory #%lu is not a multiple "
+ "of chunk size", dir->i_ino);
+ goto fail;
+Eshort:
+ error = "rec_len is smaller than minimal";
+ goto bad_entry;
+Ealign:
+ error = "unaligned directory entry";
+ goto bad_entry;
+Enamelen:
+ error = "rec_len is too small for name_len";
+ goto bad_entry;
+Espan:
+ error = "directory entry across blocks";
+ goto bad_entry;
+Einumber:
+ error = "inode out of bounds";
+bad_entry:
+ if (!quiet)
+ ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - "
+ "offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
+ dir->i_ino, error, (page->index<<PAGE_SHIFT)+offs,
+ (unsigned long) le32_to_cpu(p->inode),
+ rec_len, p->name_len);
+ goto fail;
+Eend:
+ if (!quiet) {
+ p = (ext2_dirent *)(kaddr + offs);
+ ext2_error(sb, "ext2_check_page",
+ "entry in directory #%lu spans the page boundary"
+ "offset=%lu, inode=%lu",
+ dir->i_ino, (page->index<<PAGE_SHIFT)+offs,
+ (unsigned long) le32_to_cpu(p->inode));
+ }
+fail:
+ SetPageError(page);
+ return false;
+}
+
+static struct page * ext2_get_page(struct inode *dir, unsigned long n,
+ int quiet)
+{
+ struct address_space *mapping = dir->i_mapping;
+ struct page *page = read_mapping_page(mapping, n, NULL);
+ if (!IS_ERR(page)) {
+ kmap(page);
+ if (unlikely(!PageChecked(page))) {
+ if (PageError(page) || !ext2_check_page(page, quiet))
+ goto fail;
+ }
+ }
+ return page;
+
+fail:
+ ext2_put_page(page);
+ return ERR_PTR(-EIO);
+}
+
+/*
+ * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure.
+ *
+ * len <= EXT2_NAME_LEN and de != NULL are guaranteed by caller.
+ */
+static inline int ext2_match (int len, const char * const name,
+ struct ext2_dir_entry_2 * de)
+{
+ if (len != de->name_len)
+ return 0;
+ if (!de->inode)
+ return 0;
+ return !memcmp(name, de->name, len);
+}
+
+/*
+ * p is at least 6 bytes before the end of page
+ */
+static inline ext2_dirent *ext2_next_entry(ext2_dirent *p)
+{
+ return (ext2_dirent *)((char *)p +
+ ext2_rec_len_from_disk(p->rec_len));
+}
+
+static inline unsigned
+ext2_validate_entry(char *base, unsigned offset, unsigned mask)
+{
+ ext2_dirent *de = (ext2_dirent*)(base + offset);
+ ext2_dirent *p = (ext2_dirent*)(base + (offset&mask));
+ while ((char*)p < (char*)de) {
+ if (p->rec_len == 0)
+ break;
+ p = ext2_next_entry(p);
+ }
+ return (char *)p - base;
+}
+
+static unsigned char ext2_filetype_table[EXT2_FT_MAX] = {
+ [EXT2_FT_UNKNOWN] = DT_UNKNOWN,
+ [EXT2_FT_REG_FILE] = DT_REG,
+ [EXT2_FT_DIR] = DT_DIR,
+ [EXT2_FT_CHRDEV] = DT_CHR,
+ [EXT2_FT_BLKDEV] = DT_BLK,
+ [EXT2_FT_FIFO] = DT_FIFO,
+ [EXT2_FT_SOCK] = DT_SOCK,
+ [EXT2_FT_SYMLINK] = DT_LNK,
+};
+
+#define S_SHIFT 12
+static unsigned char ext2_type_by_mode[S_IFMT >> S_SHIFT] = {
+ [S_IFREG >> S_SHIFT] = EXT2_FT_REG_FILE,
+ [S_IFDIR >> S_SHIFT] = EXT2_FT_DIR,
+ [S_IFCHR >> S_SHIFT] = EXT2_FT_CHRDEV,
+ [S_IFBLK >> S_SHIFT] = EXT2_FT_BLKDEV,
+ [S_IFIFO >> S_SHIFT] = EXT2_FT_FIFO,
+ [S_IFSOCK >> S_SHIFT] = EXT2_FT_SOCK,
+ [S_IFLNK >> S_SHIFT] = EXT2_FT_SYMLINK,
+};
+
+static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode)
+{
+ umode_t mode = inode->i_mode;
+ if (EXT2_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT2_FEATURE_INCOMPAT_FILETYPE))
+ de->file_type = ext2_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
+ else
+ de->file_type = 0;
+}
+
+static int
+ext2_readdir(struct file *file, struct dir_context *ctx)
+{
+ loff_t pos = ctx->pos;
+ struct inode *inode = file_inode(file);
+ struct super_block *sb = inode->i_sb;
+ unsigned int offset = pos & ~PAGE_MASK;
+ unsigned long n = pos >> PAGE_SHIFT;
+ unsigned long npages = dir_pages(inode);
+ unsigned chunk_mask = ~(ext2_chunk_size(inode)-1);
+ unsigned char *types = NULL;
+ bool need_revalidate = !inode_eq_iversion(inode, file->f_version);
+
+ if (pos > inode->i_size - EXT2_DIR_REC_LEN(1))
+ return 0;
+
+ if (EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE))
+ types = ext2_filetype_table;
+
+ for ( ; n < npages; n++, offset = 0) {
+ char *kaddr, *limit;
+ ext2_dirent *de;
+ struct page *page = ext2_get_page(inode, n, 0);
+
+ if (IS_ERR(page)) {
+ ext2_error(sb, __func__,
+ "bad page in #%lu",
+ inode->i_ino);
+ ctx->pos += PAGE_SIZE - offset;
+ return PTR_ERR(page);
+ }
+ kaddr = page_address(page);
+ if (unlikely(need_revalidate)) {
+ if (offset) {
+ offset = ext2_validate_entry(kaddr, offset, chunk_mask);
+ ctx->pos = (n<<PAGE_SHIFT) + offset;
+ }
+ file->f_version = inode_query_iversion(inode);
+ need_revalidate = false;
+ }
+ de = (ext2_dirent *)(kaddr+offset);
+ limit = kaddr + ext2_last_byte(inode, n) - EXT2_DIR_REC_LEN(1);
+ for ( ;(char*)de <= limit; de = ext2_next_entry(de)) {
+ if (de->rec_len == 0) {
+ ext2_error(sb, __func__,
+ "zero-length directory entry");
+ ext2_put_page(page);
+ return -EIO;
+ }
+ if (de->inode) {
+ unsigned char d_type = DT_UNKNOWN;
+
+ if (types && de->file_type < EXT2_FT_MAX)
+ d_type = types[de->file_type];
+
+ if (!dir_emit(ctx, de->name, de->name_len,
+ le32_to_cpu(de->inode),
+ d_type)) {
+ ext2_put_page(page);
+ return 0;
+ }
+ }
+ ctx->pos += ext2_rec_len_from_disk(de->rec_len);
+ }
+ ext2_put_page(page);
+ }
+ return 0;
+}
+
+/*
+ * ext2_find_entry()
+ *
+ * finds an entry in the specified directory with the wanted name. It
+ * returns the page in which the entry was found (as a parameter - res_page),
+ * and the entry itself. Page is returned mapped and unlocked.
+ * Entry is guaranteed to be valid.
+ */
+struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir,
+ const struct qstr *child, struct page **res_page)
+{
+ const char *name = child->name;
+ int namelen = child->len;
+ unsigned reclen = EXT2_DIR_REC_LEN(namelen);
+ unsigned long start, n;
+ unsigned long npages = dir_pages(dir);
+ struct page *page = NULL;
+ struct ext2_inode_info *ei = EXT2_I(dir);
+ ext2_dirent * de;
+ int dir_has_error = 0;
+
+ if (npages == 0)
+ goto out;
+
+ /* OFFSET_CACHE */
+ *res_page = NULL;
+
+ start = ei->i_dir_start_lookup;
+ if (start >= npages)
+ start = 0;
+ n = start;
+ do {
+ char *kaddr;
+ page = ext2_get_page(dir, n, dir_has_error);
+ if (!IS_ERR(page)) {
+ kaddr = page_address(page);
+ de = (ext2_dirent *) kaddr;
+ kaddr += ext2_last_byte(dir, n) - reclen;
+ while ((char *) de <= kaddr) {
+ if (de->rec_len == 0) {
+ ext2_error(dir->i_sb, __func__,
+ "zero-length directory entry");
+ ext2_put_page(page);
+ goto out;
+ }
+ if (ext2_match (namelen, name, de))
+ goto found;
+ de = ext2_next_entry(de);
+ }
+ ext2_put_page(page);
+ } else
+ dir_has_error = 1;
+
+ if (++n >= npages)
+ n = 0;
+ /* next page is past the blocks we've got */
+ if (unlikely(n > (dir->i_blocks >> (PAGE_SHIFT - 9)))) {
+ ext2_error(dir->i_sb, __func__,
+ "dir %lu size %lld exceeds block count %llu",
+ dir->i_ino, dir->i_size,
+ (unsigned long long)dir->i_blocks);
+ goto out;
+ }
+ } while (n != start);
+out:
+ return NULL;
+
+found:
+ *res_page = page;
+ ei->i_dir_start_lookup = n;
+ return de;
+}
+
+struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p)
+{
+ struct page *page = ext2_get_page(dir, 0, 0);
+ ext2_dirent *de = NULL;
+
+ if (!IS_ERR(page)) {
+ de = ext2_next_entry((ext2_dirent *) page_address(page));
+ *p = page;
+ }
+ return de;
+}
+
+ino_t ext2_inode_by_name(struct inode *dir, const struct qstr *child)
+{
+ ino_t res = 0;
+ struct ext2_dir_entry_2 *de;
+ struct page *page;
+
+ de = ext2_find_entry (dir, child, &page);
+ if (de) {
+ res = le32_to_cpu(de->inode);
+ ext2_put_page(page);
+ }
+ return res;
+}
+
+static int ext2_prepare_chunk(struct page *page, loff_t pos, unsigned len)
+{
+ return __block_write_begin(page, pos, len, ext2_get_block);
+}
+
+/* Releases the page */
+void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
+ struct page *page, struct inode *inode, int update_times)
+{
+ loff_t pos = page_offset(page) +
+ (char *) de - (char *) page_address(page);
+ unsigned len = ext2_rec_len_from_disk(de->rec_len);
+ int err;
+
+ lock_page(page);
+ err = ext2_prepare_chunk(page, pos, len);
+ BUG_ON(err);
+ de->inode = cpu_to_le32(inode->i_ino);
+ ext2_set_de_type(de, inode);
+ err = ext2_commit_chunk(page, pos, len);
+ ext2_put_page(page);
+ if (update_times)
+ dir->i_mtime = dir->i_ctime = current_time(dir);
+ EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;
+ mark_inode_dirty(dir);
+}
+
+/*
+ * Parent is locked.
+ */
+int ext2_add_link (struct dentry *dentry, struct inode *inode)
+{
+ struct inode *dir = d_inode(dentry->d_parent);
+ const char *name = dentry->d_name.name;
+ int namelen = dentry->d_name.len;
+ unsigned chunk_size = ext2_chunk_size(dir);
+ unsigned reclen = EXT2_DIR_REC_LEN(namelen);
+ unsigned short rec_len, name_len;
+ struct page *page = NULL;
+ ext2_dirent * de;
+ unsigned long npages = dir_pages(dir);
+ unsigned long n;
+ char *kaddr;
+ loff_t pos;
+ int err;
+
+ /*
+ * We take care of directory expansion in the same loop.
+ * This code plays outside i_size, so it locks the page
+ * to protect that region.
+ */
+ for (n = 0; n <= npages; n++) {
+ char *dir_end;
+
+ page = ext2_get_page(dir, n, 0);
+ err = PTR_ERR(page);
+ if (IS_ERR(page))
+ goto out;
+ lock_page(page);
+ kaddr = page_address(page);
+ dir_end = kaddr + ext2_last_byte(dir, n);
+ de = (ext2_dirent *)kaddr;
+ kaddr += PAGE_SIZE - reclen;
+ while ((char *)de <= kaddr) {
+ if ((char *)de == dir_end) {
+ /* We hit i_size */
+ name_len = 0;
+ rec_len = chunk_size;
+ de->rec_len = ext2_rec_len_to_disk(chunk_size);
+ de->inode = 0;
+ goto got_it;
+ }
+ if (de->rec_len == 0) {
+ ext2_error(dir->i_sb, __func__,
+ "zero-length directory entry");
+ err = -EIO;
+ goto out_unlock;
+ }
+ err = -EEXIST;
+ if (ext2_match (namelen, name, de))
+ goto out_unlock;
+ name_len = EXT2_DIR_REC_LEN(de->name_len);
+ rec_len = ext2_rec_len_from_disk(de->rec_len);
+ if (!de->inode && rec_len >= reclen)
+ goto got_it;
+ if (rec_len >= name_len + reclen)
+ goto got_it;
+ de = (ext2_dirent *) ((char *) de + rec_len);
+ }
+ unlock_page(page);
+ ext2_put_page(page);
+ }
+ BUG();
+ return -EINVAL;
+
+got_it:
+ pos = page_offset(page) +
+ (char*)de - (char*)page_address(page);
+ err = ext2_prepare_chunk(page, pos, rec_len);
+ if (err)
+ goto out_unlock;
+ if (de->inode) {
+ ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len);
+ de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len);
+ de->rec_len = ext2_rec_len_to_disk(name_len);
+ de = de1;
+ }
+ de->name_len = namelen;
+ memcpy(de->name, name, namelen);
+ de->inode = cpu_to_le32(inode->i_ino);
+ ext2_set_de_type (de, inode);
+ err = ext2_commit_chunk(page, pos, rec_len);
+ dir->i_mtime = dir->i_ctime = current_time(dir);
+ EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;
+ mark_inode_dirty(dir);
+ /* OFFSET_CACHE */
+out_put:
+ ext2_put_page(page);
+out:
+ return err;
+out_unlock:
+ unlock_page(page);
+ goto out_put;
+}
+
+/*
+ * ext2_delete_entry deletes a directory entry by merging it with the
+ * previous entry. Page is up-to-date. Releases the page.
+ */
+int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page )
+{
+ struct inode *inode = page->mapping->host;
+ char *kaddr = page_address(page);
+ unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1);
+ unsigned to = ((char *)dir - kaddr) +
+ ext2_rec_len_from_disk(dir->rec_len);
+ loff_t pos;
+ ext2_dirent * pde = NULL;
+ ext2_dirent * de = (ext2_dirent *) (kaddr + from);
+ int err;
+
+ while ((char*)de < (char*)dir) {
+ if (de->rec_len == 0) {
+ ext2_error(inode->i_sb, __func__,
+ "zero-length directory entry");
+ err = -EIO;
+ goto out;
+ }
+ pde = de;
+ de = ext2_next_entry(de);
+ }
+ if (pde)
+ from = (char*)pde - (char*)page_address(page);
+ pos = page_offset(page) + from;
+ lock_page(page);
+ err = ext2_prepare_chunk(page, pos, to - from);
+ BUG_ON(err);
+ if (pde)
+ pde->rec_len = ext2_rec_len_to_disk(to - from);
+ dir->inode = 0;
+ err = ext2_commit_chunk(page, pos, to - from);
+ inode->i_ctime = inode->i_mtime = current_time(inode);
+ EXT2_I(inode)->i_flags &= ~EXT2_BTREE_FL;
+ mark_inode_dirty(inode);
+out:
+ ext2_put_page(page);
+ return err;
+}
+
+/*
+ * Set the first fragment of directory.
+ */
+int ext2_make_empty(struct inode *inode, struct inode *parent)
+{
+ struct page *page = grab_cache_page(inode->i_mapping, 0);
+ unsigned chunk_size = ext2_chunk_size(inode);
+ struct ext2_dir_entry_2 * de;
+ int err;
+ void *kaddr;
+
+ if (!page)
+ return -ENOMEM;
+
+ err = ext2_prepare_chunk(page, 0, chunk_size);
+ if (err) {
+ unlock_page(page);
+ goto fail;
+ }
+ kaddr = kmap_atomic(page);
+ memset(kaddr, 0, chunk_size);
+ de = (struct ext2_dir_entry_2 *)kaddr;
+ de->name_len = 1;
+ de->rec_len = ext2_rec_len_to_disk(EXT2_DIR_REC_LEN(1));
+ memcpy (de->name, ".\0\0", 4);
+ de->inode = cpu_to_le32(inode->i_ino);
+ ext2_set_de_type (de, inode);
+
+ de = (struct ext2_dir_entry_2 *)(kaddr + EXT2_DIR_REC_LEN(1));
+ de->name_len = 2;
+ de->rec_len = ext2_rec_len_to_disk(chunk_size - EXT2_DIR_REC_LEN(1));
+ de->inode = cpu_to_le32(parent->i_ino);
+ memcpy (de->name, "..\0", 4);
+ ext2_set_de_type (de, inode);
+ kunmap_atomic(kaddr);
+ err = ext2_commit_chunk(page, 0, chunk_size);
+fail:
+ put_page(page);
+ return err;
+}
+
+/*
+ * routine to check that the specified directory is empty (for rmdir)
+ */
+int ext2_empty_dir (struct inode * inode)
+{
+ struct page *page = NULL;
+ unsigned long i, npages = dir_pages(inode);
+ int dir_has_error = 0;
+
+ for (i = 0; i < npages; i++) {
+ char *kaddr;
+ ext2_dirent * de;
+ page = ext2_get_page(inode, i, dir_has_error);
+
+ if (IS_ERR(page)) {
+ dir_has_error = 1;
+ continue;
+ }
+
+ kaddr = page_address(page);
+ de = (ext2_dirent *)kaddr;
+ kaddr += ext2_last_byte(inode, i) - EXT2_DIR_REC_LEN(1);
+
+ while ((char *)de <= kaddr) {
+ if (de->rec_len == 0) {
+ ext2_error(inode->i_sb, __func__,
+ "zero-length directory entry");
+ printk("kaddr=%p, de=%p\n", kaddr, de);
+ goto not_empty;
+ }
+ if (de->inode != 0) {
+ /* check for . and .. */
+ if (de->name[0] != '.')
+ goto not_empty;
+ if (de->name_len > 2)
+ goto not_empty;
+ if (de->name_len < 2) {
+ if (de->inode !=
+ cpu_to_le32(inode->i_ino))
+ goto not_empty;
+ } else if (de->name[1] != '.')
+ goto not_empty;
+ }
+ de = ext2_next_entry(de);
+ }
+ ext2_put_page(page);
+ }
+ return 1;
+
+not_empty:
+ ext2_put_page(page);
+ return 0;
+}
+
+const struct file_operations ext2_dir_operations = {
+ .llseek = generic_file_llseek,
+ .read = generic_read_dir,
+ .iterate_shared = ext2_readdir,
+ .unlocked_ioctl = ext2_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = ext2_compat_ioctl,
+#endif
+ .fsync = ext2_fsync,
+};
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
new file mode 100644
index 0000000..00e759f
--- /dev/null
+++ b/fs/ext2/ext2.h
@@ -0,0 +1,839 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * from
+ *
+ * linux/include/linux/minix_fs.h
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ */
+#include <linux/fs.h>
+#include <linux/ext2_fs.h>
+#include <linux/blockgroup_lock.h>
+#include <linux/percpu_counter.h>
+#include <linux/rbtree.h>
+
+/* XXX Here for now... not interested in restructing headers JUST now */
+
+/* data type for block offset of block group */
+typedef int ext2_grpblk_t;
+
+/* data type for filesystem-wide blocks number */
+typedef unsigned long ext2_fsblk_t;
+
+#define E2FSBLK "%lu"
+
+struct ext2_reserve_window {
+ ext2_fsblk_t _rsv_start; /* First byte reserved */
+ ext2_fsblk_t _rsv_end; /* Last byte reserved or 0 */
+};
+
+struct ext2_reserve_window_node {
+ struct rb_node rsv_node;
+ __u32 rsv_goal_size;
+ __u32 rsv_alloc_hit;
+ struct ext2_reserve_window rsv_window;
+};
+
+struct ext2_block_alloc_info {
+ /* information about reservation window */
+ struct ext2_reserve_window_node rsv_window_node;
+ /*
+ * was i_next_alloc_block in ext2_inode_info
+ * is the logical (file-relative) number of the
+ * most-recently-allocated block in this file.
+ * We use this for detecting linearly ascending allocation requests.
+ */
+ __u32 last_alloc_logical_block;
+ /*
+ * Was i_next_alloc_goal in ext2_inode_info
+ * is the *physical* companion to i_next_alloc_block.
+ * it the the physical block number of the block which was most-recentl
+ * allocated to this file. This give us the goal (target) for the next
+ * allocation when we detect linearly ascending requests.
+ */
+ ext2_fsblk_t last_alloc_physical_block;
+};
+
+#define rsv_start rsv_window._rsv_start
+#define rsv_end rsv_window._rsv_end
+
+struct mb_cache;
+
+/*
+ * second extended-fs super-block data in memory
+ */
+struct ext2_sb_info {
+ unsigned long s_frag_size; /* Size of a fragment in bytes */
+ unsigned long s_frags_per_block;/* Number of fragments per block */
+ unsigned long s_inodes_per_block;/* Number of inodes per block */
+ unsigned long s_frags_per_group;/* Number of fragments in a group */
+ unsigned long s_blocks_per_group;/* Number of blocks in a group */
+ unsigned long s_inodes_per_group;/* Number of inodes in a group */
+ unsigned long s_itb_per_group; /* Number of inode table blocks per group */
+ unsigned long s_gdb_count; /* Number of group descriptor blocks */
+ unsigned long s_desc_per_block; /* Number of group descriptors per block */
+ unsigned long s_groups_count; /* Number of groups in the fs */
+ unsigned long s_overhead_last; /* Last calculated overhead */
+ unsigned long s_blocks_last; /* Last seen block count */
+ struct buffer_head * s_sbh; /* Buffer containing the super block */
+ struct ext2_super_block * s_es; /* Pointer to the super block in the buffer */
+ struct buffer_head ** s_group_desc;
+ unsigned long s_mount_opt;
+ unsigned long s_sb_block;
+ kuid_t s_resuid;
+ kgid_t s_resgid;
+ unsigned short s_mount_state;
+ unsigned short s_pad;
+ int s_addr_per_block_bits;
+ int s_desc_per_block_bits;
+ int s_inode_size;
+ int s_first_ino;
+ spinlock_t s_next_gen_lock;
+ u32 s_next_generation;
+ unsigned long s_dir_count;
+ u8 *s_debts;
+ struct percpu_counter s_freeblocks_counter;
+ struct percpu_counter s_freeinodes_counter;
+ struct percpu_counter s_dirs_counter;
+ struct blockgroup_lock *s_blockgroup_lock;
+ /* root of the per fs reservation window tree */
+ spinlock_t s_rsv_window_lock;
+ struct rb_root s_rsv_window_root;
+ struct ext2_reserve_window_node s_rsv_window_head;
+ /*
+ * s_lock protects against concurrent modifications of s_mount_state,
+ * s_blocks_last, s_overhead_last and the content of superblock's
+ * buffer pointed to by sbi->s_es.
+ *
+ * Note: It is used in ext2_show_options() to provide a consistent view
+ * of the mount options.
+ */
+ spinlock_t s_lock;
+ struct mb_cache *s_ea_block_cache;
+ struct dax_device *s_daxdev;
+};
+
+static inline spinlock_t *
+sb_bgl_lock(struct ext2_sb_info *sbi, unsigned int block_group)
+{
+ return bgl_lock_ptr(sbi->s_blockgroup_lock, block_group);
+}
+
+/*
+ * Define EXT2FS_DEBUG to produce debug messages
+ */
+#undef EXT2FS_DEBUG
+
+/*
+ * Define EXT2_RESERVATION to reserve data blocks for expanding files
+ */
+#define EXT2_DEFAULT_RESERVE_BLOCKS 8
+/*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
+#define EXT2_MAX_RESERVE_BLOCKS 1027
+#define EXT2_RESERVE_WINDOW_NOT_ALLOCATED 0
+/*
+ * The second extended file system version
+ */
+#define EXT2FS_DATE "95/08/09"
+#define EXT2FS_VERSION "0.5b"
+
+/*
+ * Debug code
+ */
+#ifdef EXT2FS_DEBUG
+# define ext2_debug(f, a...) { \
+ printk ("EXT2-fs DEBUG (%s, %d): %s:", \
+ __FILE__, __LINE__, __func__); \
+ printk (f, ## a); \
+ }
+#else
+# define ext2_debug(f, a...) /**/
+#endif
+
+/*
+ * Special inode numbers
+ */
+#define EXT2_BAD_INO 1 /* Bad blocks inode */
+#define EXT2_ROOT_INO 2 /* Root inode */
+#define EXT2_BOOT_LOADER_INO 5 /* Boot loader inode */
+#define EXT2_UNDEL_DIR_INO 6 /* Undelete directory inode */
+
+/* First non-reserved inode for old ext2 filesystems */
+#define EXT2_GOOD_OLD_FIRST_INO 11
+
+static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
+{
+ return sb->s_fs_info;
+}
+
+/*
+ * Macro-instructions used to manage several block sizes
+ */
+#define EXT2_MIN_BLOCK_SIZE 1024
+#define EXT2_MAX_BLOCK_SIZE 4096
+#define EXT2_MIN_BLOCK_LOG_SIZE 10
+#define EXT2_BLOCK_SIZE(s) ((s)->s_blocksize)
+#define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
+#define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_blocksize_bits)
+#define EXT2_ADDR_PER_BLOCK_BITS(s) (EXT2_SB(s)->s_addr_per_block_bits)
+#define EXT2_INODE_SIZE(s) (EXT2_SB(s)->s_inode_size)
+#define EXT2_FIRST_INO(s) (EXT2_SB(s)->s_first_ino)
+
+/*
+ * Macro-instructions used to manage fragments
+ */
+#define EXT2_MIN_FRAG_SIZE 1024
+#define EXT2_MAX_FRAG_SIZE 4096
+#define EXT2_MIN_FRAG_LOG_SIZE 10
+#define EXT2_FRAG_SIZE(s) (EXT2_SB(s)->s_frag_size)
+#define EXT2_FRAGS_PER_BLOCK(s) (EXT2_SB(s)->s_frags_per_block)
+
+/*
+ * Structure of a blocks group descriptor
+ */
+struct ext2_group_desc
+{
+ __le32 bg_block_bitmap; /* Blocks bitmap block */
+ __le32 bg_inode_bitmap; /* Inodes bitmap block */
+ __le32 bg_inode_table; /* Inodes table block */
+ __le16 bg_free_blocks_count; /* Free blocks count */
+ __le16 bg_free_inodes_count; /* Free inodes count */
+ __le16 bg_used_dirs_count; /* Directories count */
+ __le16 bg_pad;
+ __le32 bg_reserved[3];
+};
+
+/*
+ * Macro-instructions used to manage group descriptors
+ */
+#define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->s_blocks_per_group)
+#define EXT2_DESC_PER_BLOCK(s) (EXT2_SB(s)->s_desc_per_block)
+#define EXT2_INODES_PER_GROUP(s) (EXT2_SB(s)->s_inodes_per_group)
+#define EXT2_DESC_PER_BLOCK_BITS(s) (EXT2_SB(s)->s_desc_per_block_bits)
+
+/*
+ * Constants relative to the data blocks
+ */
+#define EXT2_NDIR_BLOCKS 12
+#define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS
+#define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1)
+#define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1)
+#define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1)
+
+/*
+ * Inode flags (GETFLAGS/SETFLAGS)
+ */
+#define EXT2_SECRM_FL FS_SECRM_FL /* Secure deletion */
+#define EXT2_UNRM_FL FS_UNRM_FL /* Undelete */
+#define EXT2_COMPR_FL FS_COMPR_FL /* Compress file */
+#define EXT2_SYNC_FL FS_SYNC_FL /* Synchronous updates */
+#define EXT2_IMMUTABLE_FL FS_IMMUTABLE_FL /* Immutable file */
+#define EXT2_APPEND_FL FS_APPEND_FL /* writes to file may only append */
+#define EXT2_NODUMP_FL FS_NODUMP_FL /* do not dump file */
+#define EXT2_NOATIME_FL FS_NOATIME_FL /* do not update atime */
+/* Reserved for compression usage... */
+#define EXT2_DIRTY_FL FS_DIRTY_FL
+#define EXT2_COMPRBLK_FL FS_COMPRBLK_FL /* One or more compressed clusters */
+#define EXT2_NOCOMP_FL FS_NOCOMP_FL /* Don't compress */
+#define EXT2_ECOMPR_FL FS_ECOMPR_FL /* Compression error */
+/* End compression flags --- maybe not all used */
+#define EXT2_BTREE_FL FS_BTREE_FL /* btree format dir */
+#define EXT2_INDEX_FL FS_INDEX_FL /* hash-indexed directory */
+#define EXT2_IMAGIC_FL FS_IMAGIC_FL /* AFS directory */
+#define EXT2_JOURNAL_DATA_FL FS_JOURNAL_DATA_FL /* Reserved for ext3 */
+#define EXT2_NOTAIL_FL FS_NOTAIL_FL /* file tail should not be merged */
+#define EXT2_DIRSYNC_FL FS_DIRSYNC_FL /* dirsync behaviour (directories only) */
+#define EXT2_TOPDIR_FL FS_TOPDIR_FL /* Top of directory hierarchies*/
+#define EXT2_RESERVED_FL FS_RESERVED_FL /* reserved for ext2 lib */
+
+#define EXT2_FL_USER_VISIBLE FS_FL_USER_VISIBLE /* User visible flags */
+#define EXT2_FL_USER_MODIFIABLE FS_FL_USER_MODIFIABLE /* User modifiable flags */
+
+/* Flags that should be inherited by new inodes from their parent. */
+#define EXT2_FL_INHERITED (EXT2_SECRM_FL | EXT2_UNRM_FL | EXT2_COMPR_FL |\
+ EXT2_SYNC_FL | EXT2_NODUMP_FL |\
+ EXT2_NOATIME_FL | EXT2_COMPRBLK_FL |\
+ EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\
+ EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL)
+
+/* Flags that are appropriate for regular files (all but dir-specific ones). */
+#define EXT2_REG_FLMASK (~(EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL))
+
+/* Flags that are appropriate for non-directories/regular files. */
+#define EXT2_OTHER_FLMASK (EXT2_NODUMP_FL | EXT2_NOATIME_FL)
+
+/* Mask out flags that are inappropriate for the given type of inode. */
+static inline __u32 ext2_mask_flags(umode_t mode, __u32 flags)
+{
+ if (S_ISDIR(mode))
+ return flags;
+ else if (S_ISREG(mode))
+ return flags & EXT2_REG_FLMASK;
+ else
+ return flags & EXT2_OTHER_FLMASK;
+}
+
+/*
+ * ioctl commands
+ */
+#define EXT2_IOC_GETFLAGS FS_IOC_GETFLAGS
+#define EXT2_IOC_SETFLAGS FS_IOC_SETFLAGS
+#define EXT2_IOC_GETVERSION FS_IOC_GETVERSION
+#define EXT2_IOC_SETVERSION FS_IOC_SETVERSION
+#define EXT2_IOC_GETRSVSZ _IOR('f', 5, long)
+#define EXT2_IOC_SETRSVSZ _IOW('f', 6, long)
+
+/*
+ * ioctl commands in 32 bit emulation
+ */
+#define EXT2_IOC32_GETFLAGS FS_IOC32_GETFLAGS
+#define EXT2_IOC32_SETFLAGS FS_IOC32_SETFLAGS
+#define EXT2_IOC32_GETVERSION FS_IOC32_GETVERSION
+#define EXT2_IOC32_SETVERSION FS_IOC32_SETVERSION
+
+/*
+ * Structure of an inode on the disk
+ */
+struct ext2_inode {
+ __le16 i_mode; /* File mode */
+ __le16 i_uid; /* Low 16 bits of Owner Uid */
+ __le32 i_size; /* Size in bytes */
+ __le32 i_atime; /* Access time */
+ __le32 i_ctime; /* Creation time */
+ __le32 i_mtime; /* Modification time */
+ __le32 i_dtime; /* Deletion Time */
+ __le16 i_gid; /* Low 16 bits of Group Id */
+ __le16 i_links_count; /* Links count */
+ __le32 i_blocks; /* Blocks count */
+ __le32 i_flags; /* File flags */
+ union {
+ struct {
+ __le32 l_i_reserved1;
+ } linux1;
+ struct {
+ __le32 h_i_translator;
+ } hurd1;
+ struct {
+ __le32 m_i_reserved1;
+ } masix1;
+ } osd1; /* OS dependent 1 */
+ __le32 i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
+ __le32 i_generation; /* File version (for NFS) */
+ __le32 i_file_acl; /* File ACL */
+ __le32 i_dir_acl; /* Directory ACL */
+ __le32 i_faddr; /* Fragment address */
+ union {
+ struct {
+ __u8 l_i_frag; /* Fragment number */
+ __u8 l_i_fsize; /* Fragment size */
+ __u16 i_pad1;
+ __le16 l_i_uid_high; /* these 2 fields */
+ __le16 l_i_gid_high; /* were reserved2[0] */
+ __u32 l_i_reserved2;
+ } linux2;
+ struct {
+ __u8 h_i_frag; /* Fragment number */
+ __u8 h_i_fsize; /* Fragment size */
+ __le16 h_i_mode_high;
+ __le16 h_i_uid_high;
+ __le16 h_i_gid_high;
+ __le32 h_i_author;
+ } hurd2;
+ struct {
+ __u8 m_i_frag; /* Fragment number */
+ __u8 m_i_fsize; /* Fragment size */
+ __u16 m_pad1;
+ __u32 m_i_reserved2[2];
+ } masix2;
+ } osd2; /* OS dependent 2 */
+};
+
+#define i_size_high i_dir_acl
+
+#define i_reserved1 osd1.linux1.l_i_reserved1
+#define i_frag osd2.linux2.l_i_frag
+#define i_fsize osd2.linux2.l_i_fsize
+#define i_uid_low i_uid
+#define i_gid_low i_gid
+#define i_uid_high osd2.linux2.l_i_uid_high
+#define i_gid_high osd2.linux2.l_i_gid_high
+#define i_reserved2 osd2.linux2.l_i_reserved2
+
+/*
+ * File system states
+ */
+#define EXT2_VALID_FS 0x0001 /* Unmounted cleanly */
+#define EXT2_ERROR_FS 0x0002 /* Errors detected */
+#define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
+
+/*
+ * Mount flags
+ */
+#define EXT2_MOUNT_CHECK 0x000001 /* Do mount-time checks */
+#define EXT2_MOUNT_OLDALLOC 0x000002 /* Don't use the new Orlov allocator */
+#define EXT2_MOUNT_GRPID 0x000004 /* Create files with directory's group */
+#define EXT2_MOUNT_DEBUG 0x000008 /* Some debugging messages */
+#define EXT2_MOUNT_ERRORS_CONT 0x000010 /* Continue on errors */
+#define EXT2_MOUNT_ERRORS_RO 0x000020 /* Remount fs ro on errors */
+#define EXT2_MOUNT_ERRORS_PANIC 0x000040 /* Panic on errors */
+#define EXT2_MOUNT_MINIX_DF 0x000080 /* Mimics the Minix statfs */
+#define EXT2_MOUNT_NOBH 0x000100 /* No buffer_heads */
+#define EXT2_MOUNT_NO_UID32 0x000200 /* Disable 32-bit UIDs */
+#define EXT2_MOUNT_XATTR_USER 0x004000 /* Extended user attributes */
+#define EXT2_MOUNT_POSIX_ACL 0x008000 /* POSIX Access Control Lists */
+#define EXT2_MOUNT_XIP 0x010000 /* Obsolete, use DAX */
+#define EXT2_MOUNT_USRQUOTA 0x020000 /* user quota */
+#define EXT2_MOUNT_GRPQUOTA 0x040000 /* group quota */
+#define EXT2_MOUNT_RESERVATION 0x080000 /* Preallocation */
+#ifdef CONFIG_FS_DAX
+#define EXT2_MOUNT_DAX 0x100000 /* Direct Access */
+#else
+#define EXT2_MOUNT_DAX 0
+#endif
+
+
+#define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt
+#define set_opt(o, opt) o |= EXT2_MOUNT_##opt
+#define test_opt(sb, opt) (EXT2_SB(sb)->s_mount_opt & \
+ EXT2_MOUNT_##opt)
+/*
+ * Maximal mount counts between two filesystem checks
+ */
+#define EXT2_DFL_MAX_MNT_COUNT 20 /* Allow 20 mounts */
+#define EXT2_DFL_CHECKINTERVAL 0 /* Don't use interval check */
+
+/*
+ * Behaviour when detecting errors
+ */
+#define EXT2_ERRORS_CONTINUE 1 /* Continue execution */
+#define EXT2_ERRORS_RO 2 /* Remount fs read-only */
+#define EXT2_ERRORS_PANIC 3 /* Panic */
+#define EXT2_ERRORS_DEFAULT EXT2_ERRORS_CONTINUE
+
+/*
+ * Structure of the super block
+ */
+struct ext2_super_block {
+ __le32 s_inodes_count; /* Inodes count */
+ __le32 s_blocks_count; /* Blocks count */
+ __le32 s_r_blocks_count; /* Reserved blocks count */
+ __le32 s_free_blocks_count; /* Free blocks count */
+ __le32 s_free_inodes_count; /* Free inodes count */
+ __le32 s_first_data_block; /* First Data Block */
+ __le32 s_log_block_size; /* Block size */
+ __le32 s_log_frag_size; /* Fragment size */
+ __le32 s_blocks_per_group; /* # Blocks per group */
+ __le32 s_frags_per_group; /* # Fragments per group */
+ __le32 s_inodes_per_group; /* # Inodes per group */
+ __le32 s_mtime; /* Mount time */
+ __le32 s_wtime; /* Write time */
+ __le16 s_mnt_count; /* Mount count */
+ __le16 s_max_mnt_count; /* Maximal mount count */
+ __le16 s_magic; /* Magic signature */
+ __le16 s_state; /* File system state */
+ __le16 s_errors; /* Behaviour when detecting errors */
+ __le16 s_minor_rev_level; /* minor revision level */
+ __le32 s_lastcheck; /* time of last check */
+ __le32 s_checkinterval; /* max. time between checks */
+ __le32 s_creator_os; /* OS */
+ __le32 s_rev_level; /* Revision level */
+ __le16 s_def_resuid; /* Default uid for reserved blocks */
+ __le16 s_def_resgid; /* Default gid for reserved blocks */
+ /*
+ * These fields are for EXT2_DYNAMIC_REV superblocks only.
+ *
+ * Note: the difference between the compatible feature set and
+ * the incompatible feature set is that if there is a bit set
+ * in the incompatible feature set that the kernel doesn't
+ * know about, it should refuse to mount the filesystem.
+ *
+ * e2fsck's requirements are more strict; if it doesn't know
+ * about a feature in either the compatible or incompatible
+ * feature set, it must abort and not try to meddle with
+ * things it doesn't understand...
+ */
+ __le32 s_first_ino; /* First non-reserved inode */
+ __le16 s_inode_size; /* size of inode structure */
+ __le16 s_block_group_nr; /* block group # of this superblock */
+ __le32 s_feature_compat; /* compatible feature set */
+ __le32 s_feature_incompat; /* incompatible feature set */
+ __le32 s_feature_ro_compat; /* readonly-compatible feature set */
+ __u8 s_uuid[16]; /* 128-bit uuid for volume */
+ char s_volume_name[16]; /* volume name */
+ char s_last_mounted[64]; /* directory where last mounted */
+ __le32 s_algorithm_usage_bitmap; /* For compression */
+ /*
+ * Performance hints. Directory preallocation should only
+ * happen if the EXT2_COMPAT_PREALLOC flag is on.
+ */
+ __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/
+ __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */
+ __u16 s_padding1;
+ /*
+ * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
+ */
+ __u8 s_journal_uuid[16]; /* uuid of journal superblock */
+ __u32 s_journal_inum; /* inode number of journal file */
+ __u32 s_journal_dev; /* device number of journal file */
+ __u32 s_last_orphan; /* start of list of inodes to delete */
+ __u32 s_hash_seed[4]; /* HTREE hash seed */
+ __u8 s_def_hash_version; /* Default hash version to use */
+ __u8 s_reserved_char_pad;
+ __u16 s_reserved_word_pad;
+ __le32 s_default_mount_opts;
+ __le32 s_first_meta_bg; /* First metablock block group */
+ __u32 s_reserved[190]; /* Padding to the end of the block */
+};
+
+/*
+ * Codes for operating systems
+ */
+#define EXT2_OS_LINUX 0
+#define EXT2_OS_HURD 1
+#define EXT2_OS_MASIX 2
+#define EXT2_OS_FREEBSD 3
+#define EXT2_OS_LITES 4
+
+/*
+ * Revision levels
+ */
+#define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */
+#define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */
+
+#define EXT2_CURRENT_REV EXT2_GOOD_OLD_REV
+#define EXT2_MAX_SUPP_REV EXT2_DYNAMIC_REV
+
+#define EXT2_GOOD_OLD_INODE_SIZE 128
+
+/*
+ * Feature set definitions
+ */
+
+#define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
+ ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
+#define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
+ ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
+#define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
+ ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
+#define EXT2_SET_COMPAT_FEATURE(sb,mask) \
+ EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
+#define EXT2_SET_RO_COMPAT_FEATURE(sb,mask) \
+ EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
+#define EXT2_SET_INCOMPAT_FEATURE(sb,mask) \
+ EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
+#define EXT2_CLEAR_COMPAT_FEATURE(sb,mask) \
+ EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
+#define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask) \
+ EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
+#define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask) \
+ EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
+
+#define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001
+#define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002
+#define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
+#define EXT2_FEATURE_COMPAT_EXT_ATTR 0x0008
+#define EXT2_FEATURE_COMPAT_RESIZE_INO 0x0010
+#define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020
+#define EXT2_FEATURE_COMPAT_ANY 0xffffffff
+
+#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
+#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
+#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
+#define EXT2_FEATURE_RO_COMPAT_ANY 0xffffffff
+
+#define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001
+#define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
+#define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004
+#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
+#define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
+#define EXT2_FEATURE_INCOMPAT_ANY 0xffffffff
+
+#define EXT2_FEATURE_COMPAT_SUPP EXT2_FEATURE_COMPAT_EXT_ATTR
+#define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
+ EXT2_FEATURE_INCOMPAT_META_BG)
+#define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
+ EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
+ EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
+#define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT2_FEATURE_RO_COMPAT_SUPP
+#define EXT2_FEATURE_INCOMPAT_UNSUPPORTED ~EXT2_FEATURE_INCOMPAT_SUPP
+
+/*
+ * Default values for user and/or group using reserved blocks
+ */
+#define EXT2_DEF_RESUID 0
+#define EXT2_DEF_RESGID 0
+
+/*
+ * Default mount options
+ */
+#define EXT2_DEFM_DEBUG 0x0001
+#define EXT2_DEFM_BSDGROUPS 0x0002
+#define EXT2_DEFM_XATTR_USER 0x0004
+#define EXT2_DEFM_ACL 0x0008
+#define EXT2_DEFM_UID16 0x0010
+ /* Not used by ext2, but reserved for use by ext3 */
+#define EXT3_DEFM_JMODE 0x0060
+#define EXT3_DEFM_JMODE_DATA 0x0020
+#define EXT3_DEFM_JMODE_ORDERED 0x0040
+#define EXT3_DEFM_JMODE_WBACK 0x0060
+
+/*
+ * Structure of a directory entry
+ */
+
+struct ext2_dir_entry {
+ __le32 inode; /* Inode number */
+ __le16 rec_len; /* Directory entry length */
+ __le16 name_len; /* Name length */
+ char name[]; /* File name, up to EXT2_NAME_LEN */
+};
+
+/*
+ * The new version of the directory entry. Since EXT2 structures are
+ * stored in intel byte order, and the name_len field could never be
+ * bigger than 255 chars, it's safe to reclaim the extra byte for the
+ * file_type field.
+ */
+struct ext2_dir_entry_2 {
+ __le32 inode; /* Inode number */
+ __le16 rec_len; /* Directory entry length */
+ __u8 name_len; /* Name length */
+ __u8 file_type;
+ char name[]; /* File name, up to EXT2_NAME_LEN */
+};
+
+/*
+ * Ext2 directory file types. Only the low 3 bits are used. The
+ * other bits are reserved for now.
+ */
+enum {
+ EXT2_FT_UNKNOWN = 0,
+ EXT2_FT_REG_FILE = 1,
+ EXT2_FT_DIR = 2,
+ EXT2_FT_CHRDEV = 3,
+ EXT2_FT_BLKDEV = 4,
+ EXT2_FT_FIFO = 5,
+ EXT2_FT_SOCK = 6,
+ EXT2_FT_SYMLINK = 7,
+ EXT2_FT_MAX
+};
+
+/*
+ * EXT2_DIR_PAD defines the directory entries boundaries
+ *
+ * NOTE: It must be a multiple of 4
+ */
+#define EXT2_DIR_PAD 4
+#define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1)
+#define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \
+ ~EXT2_DIR_ROUND)
+#define EXT2_MAX_REC_LEN ((1<<16)-1)
+
+static inline void verify_offsets(void)
+{
+#define A(x,y) BUILD_BUG_ON(x != offsetof(struct ext2_super_block, y));
+ A(EXT2_SB_MAGIC_OFFSET, s_magic);
+ A(EXT2_SB_BLOCKS_OFFSET, s_blocks_count);
+ A(EXT2_SB_BSIZE_OFFSET, s_log_block_size);
+#undef A
+}
+
+/*
+ * ext2 mount options
+ */
+struct ext2_mount_options {
+ unsigned long s_mount_opt;
+ kuid_t s_resuid;
+ kgid_t s_resgid;
+};
+
+/*
+ * second extended file system inode data in memory
+ */
+struct ext2_inode_info {
+ __le32 i_data[15];
+ __u32 i_flags;
+ __u32 i_faddr;
+ __u8 i_frag_no;
+ __u8 i_frag_size;
+ __u16 i_state;
+ __u32 i_file_acl;
+ __u32 i_dir_acl;
+ __u32 i_dtime;
+
+ /*
+ * i_block_group is the number of the block group which contains
+ * this file's inode. Constant across the lifetime of the inode,
+ * it is used for making block allocation decisions - we try to
+ * place a file's data blocks near its inode block, and new inodes
+ * near to their parent directory's inode.
+ */
+ __u32 i_block_group;
+
+ /* block reservation info */
+ struct ext2_block_alloc_info *i_block_alloc_info;
+
+ __u32 i_dir_start_lookup;
+#ifdef CONFIG_EXT2_FS_XATTR
+ /*
+ * Extended attributes can be read independently of the main file
+ * data. Taking i_mutex even when reading would cause contention
+ * between readers of EAs and writers of regular file data, so
+ * instead we synchronize on xattr_sem when reading or changing
+ * EAs.
+ */
+ struct rw_semaphore xattr_sem;
+#endif
+ rwlock_t i_meta_lock;
+#ifdef CONFIG_FS_DAX
+ struct rw_semaphore dax_sem;
+#endif
+
+ /*
+ * truncate_mutex is for serialising ext2_truncate() against
+ * ext2_getblock(). It also protects the internals of the inode's
+ * reservation data structures: ext2_reserve_window and
+ * ext2_reserve_window_node.
+ */
+ struct mutex truncate_mutex;
+ struct inode vfs_inode;
+ struct list_head i_orphan; /* unlinked but open inodes */
+#ifdef CONFIG_QUOTA
+ struct dquot *i_dquot[MAXQUOTAS];
+#endif
+};
+
+#ifdef CONFIG_FS_DAX
+#define dax_sem_down_write(ext2_inode) down_write(&(ext2_inode)->dax_sem)
+#define dax_sem_up_write(ext2_inode) up_write(&(ext2_inode)->dax_sem)
+#else
+#define dax_sem_down_write(ext2_inode)
+#define dax_sem_up_write(ext2_inode)
+#endif
+
+/*
+ * Inode dynamic state flags
+ */
+#define EXT2_STATE_NEW 0x00000001 /* inode is newly created */
+
+
+/*
+ * Function prototypes
+ */
+
+/*
+ * Ok, these declarations are also in <linux/kernel.h> but none of the
+ * ext2 source programs needs to include it so they are duplicated here.
+ */
+
+static inline struct ext2_inode_info *EXT2_I(struct inode *inode)
+{
+ return container_of(inode, struct ext2_inode_info, vfs_inode);
+}
+
+/* balloc.c */
+extern int ext2_bg_has_super(struct super_block *sb, int group);
+extern unsigned long ext2_bg_num_gdb(struct super_block *sb, int group);
+extern ext2_fsblk_t ext2_new_block(struct inode *, unsigned long, int *);
+extern ext2_fsblk_t ext2_new_blocks(struct inode *, unsigned long,
+ unsigned long *, int *);
+extern int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk,
+ unsigned int count);
+extern void ext2_free_blocks (struct inode *, unsigned long,
+ unsigned long);
+extern unsigned long ext2_count_free_blocks (struct super_block *);
+extern unsigned long ext2_count_dirs (struct super_block *);
+extern struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
+ unsigned int block_group,
+ struct buffer_head ** bh);
+extern void ext2_discard_reservation (struct inode *);
+extern int ext2_should_retry_alloc(struct super_block *sb, int *retries);
+extern void ext2_init_block_alloc_info(struct inode *);
+extern void ext2_rsv_window_add(struct super_block *sb, struct ext2_reserve_window_node *rsv);
+
+/* dir.c */
+extern int ext2_add_link (struct dentry *, struct inode *);
+extern ino_t ext2_inode_by_name(struct inode *, const struct qstr *);
+extern int ext2_make_empty(struct inode *, struct inode *);
+extern struct ext2_dir_entry_2 * ext2_find_entry (struct inode *,const struct qstr *, struct page **);
+extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *);
+extern int ext2_empty_dir (struct inode *);
+extern struct ext2_dir_entry_2 * ext2_dotdot (struct inode *, struct page **);
+extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, struct inode *, int);
+
+/* ialloc.c */
+extern struct inode * ext2_new_inode (struct inode *, umode_t, const struct qstr *);
+extern void ext2_free_inode (struct inode *);
+extern unsigned long ext2_count_free_inodes (struct super_block *);
+extern unsigned long ext2_count_free (struct buffer_head *, unsigned);
+
+/* inode.c */
+extern struct inode *ext2_iget (struct super_block *, unsigned long);
+extern int ext2_write_inode (struct inode *, struct writeback_control *);
+extern void ext2_evict_inode(struct inode *);
+extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
+extern int ext2_setattr (struct dentry *, struct iattr *);
+extern void ext2_set_inode_flags(struct inode *inode);
+extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+ u64 start, u64 len);
+
+/* ioctl.c */
+extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
+extern long ext2_compat_ioctl(struct file *, unsigned int, unsigned long);
+
+/* namei.c */
+struct dentry *ext2_get_parent(struct dentry *child);
+
+/* super.c */
+extern __printf(3, 4)
+void ext2_error(struct super_block *, const char *, const char *, ...);
+extern __printf(3, 4)
+void ext2_msg(struct super_block *, const char *, const char *, ...);
+extern void ext2_update_dynamic_rev (struct super_block *sb);
+extern void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
+ int wait);
+
+/*
+ * Inodes and files operations
+ */
+
+/* dir.c */
+extern const struct file_operations ext2_dir_operations;
+
+/* file.c */
+extern int ext2_fsync(struct file *file, loff_t start, loff_t end,
+ int datasync);
+extern const struct inode_operations ext2_file_inode_operations;
+extern const struct file_operations ext2_file_operations;
+
+/* inode.c */
+extern void ext2_set_file_ops(struct inode *inode);
+extern const struct address_space_operations ext2_aops;
+extern const struct address_space_operations ext2_nobh_aops;
+extern const struct iomap_ops ext2_iomap_ops;
+
+/* namei.c */
+extern const struct inode_operations ext2_dir_inode_operations;
+extern const struct inode_operations ext2_special_inode_operations;
+
+/* symlink.c */
+extern const struct inode_operations ext2_fast_symlink_inode_operations;
+extern const struct inode_operations ext2_symlink_inode_operations;
+
+static inline ext2_fsblk_t
+ext2_group_first_block_no(struct super_block *sb, unsigned long group_no)
+{
+ return group_no * (ext2_fsblk_t)EXT2_BLOCKS_PER_GROUP(sb) +
+ le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block);
+}
+
+#define ext2_set_bit __test_and_set_bit_le
+#define ext2_clear_bit __test_and_clear_bit_le
+#define ext2_test_bit test_bit_le
+#define ext2_find_first_zero_bit find_first_zero_bit_le
+#define ext2_find_next_zero_bit find_next_zero_bit_le
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
new file mode 100644
index 0000000..28b2609
--- /dev/null
+++ b/fs/ext2/file.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/file.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * from
+ *
+ * linux/fs/minix/file.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * ext2 fs regular file handling primitives
+ *
+ * 64-bit file support on 64-bit platforms by Jakub Jelinek
+ * (jj@sunsite.ms.mff.cuni.cz)
+ */
+
+#include <linux/time.h>
+#include <linux/pagemap.h>
+#include <linux/dax.h>
+#include <linux/quotaops.h>
+#include <linux/iomap.h>
+#include <linux/uio.h>
+#include "ext2.h"
+#include "xattr.h"
+#include "acl.h"
+
+#ifdef CONFIG_FS_DAX
+static ssize_t ext2_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct inode *inode = iocb->ki_filp->f_mapping->host;
+ ssize_t ret;
+
+ if (!iov_iter_count(to))
+ return 0; /* skip atime */
+
+ inode_lock_shared(inode);
+ ret = dax_iomap_rw(iocb, to, &ext2_iomap_ops);
+ inode_unlock_shared(inode);
+
+ file_accessed(iocb->ki_filp);
+ return ret;
+}
+
+static ssize_t ext2_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ ssize_t ret;
+
+ inode_lock(inode);
+ ret = generic_write_checks(iocb, from);
+ if (ret <= 0)
+ goto out_unlock;
+ ret = file_remove_privs(file);
+ if (ret)
+ goto out_unlock;
+ ret = file_update_time(file);
+ if (ret)
+ goto out_unlock;
+
+ ret = dax_iomap_rw(iocb, from, &ext2_iomap_ops);
+ if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
+ i_size_write(inode, iocb->ki_pos);
+ mark_inode_dirty(inode);
+ }
+
+out_unlock:
+ inode_unlock(inode);
+ if (ret > 0)
+ ret = generic_write_sync(iocb, ret);
+ return ret;
+}
+
+/*
+ * The lock ordering for ext2 DAX fault paths is:
+ *
+ * mmap_sem (MM)
+ * sb_start_pagefault (vfs, freeze)
+ * ext2_inode_info->dax_sem
+ * address_space->i_mmap_rwsem or page_lock (mutually exclusive in DAX)
+ * ext2_inode_info->truncate_mutex
+ *
+ * The default page_lock and i_size verification done by non-DAX fault paths
+ * is sufficient because ext2 doesn't support hole punching.
+ */
+static vm_fault_t ext2_dax_fault(struct vm_fault *vmf)
+{
+ struct inode *inode = file_inode(vmf->vma->vm_file);
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ vm_fault_t ret;
+
+ if (vmf->flags & FAULT_FLAG_WRITE) {
+ sb_start_pagefault(inode->i_sb);
+ file_update_time(vmf->vma->vm_file);
+ }
+ down_read(&ei->dax_sem);
+
+ ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, NULL, &ext2_iomap_ops);
+
+ up_read(&ei->dax_sem);
+ if (vmf->flags & FAULT_FLAG_WRITE)
+ sb_end_pagefault(inode->i_sb);
+ return ret;
+}
+
+static const struct vm_operations_struct ext2_dax_vm_ops = {
+ .fault = ext2_dax_fault,
+ /*
+ * .huge_fault is not supported for DAX because allocation in ext2
+ * cannot be reliably aligned to huge page sizes and so pmd faults
+ * will always fail and fail back to regular faults.
+ */
+ .page_mkwrite = ext2_dax_fault,
+ .pfn_mkwrite = ext2_dax_fault,
+};
+
+static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ if (!IS_DAX(file_inode(file)))
+ return generic_file_mmap(file, vma);
+
+ file_accessed(file);
+ vma->vm_ops = &ext2_dax_vm_ops;
+ return 0;
+}
+#else
+#define ext2_file_mmap generic_file_mmap
+#endif
+
+/*
+ * Called when filp is released. This happens when all file descriptors
+ * for a single struct file are closed. Note that different open() calls
+ * for the same file yield different struct file structures.
+ */
+static int ext2_release_file (struct inode * inode, struct file * filp)
+{
+ if (filp->f_mode & FMODE_WRITE) {
+ mutex_lock(&EXT2_I(inode)->truncate_mutex);
+ ext2_discard_reservation(inode);
+ mutex_unlock(&EXT2_I(inode)->truncate_mutex);
+ }
+ return 0;
+}
+
+int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
+{
+ int ret;
+ struct super_block *sb = file->f_mapping->host->i_sb;
+
+ ret = generic_file_fsync(file, start, end, datasync);
+ if (ret == -EIO)
+ /* We don't really know where the IO error happened... */
+ ext2_error(sb, __func__,
+ "detected IO error when writing metadata buffers");
+ return ret;
+}
+
+static ssize_t ext2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+#ifdef CONFIG_FS_DAX
+ if (IS_DAX(iocb->ki_filp->f_mapping->host))
+ return ext2_dax_read_iter(iocb, to);
+#endif
+ return generic_file_read_iter(iocb, to);
+}
+
+static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+#ifdef CONFIG_FS_DAX
+ if (IS_DAX(iocb->ki_filp->f_mapping->host))
+ return ext2_dax_write_iter(iocb, from);
+#endif
+ return generic_file_write_iter(iocb, from);
+}
+
+const struct file_operations ext2_file_operations = {
+ .llseek = generic_file_llseek,
+ .read_iter = ext2_file_read_iter,
+ .write_iter = ext2_file_write_iter,
+ .unlocked_ioctl = ext2_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = ext2_compat_ioctl,
+#endif
+ .mmap = ext2_file_mmap,
+ .open = dquot_file_open,
+ .release = ext2_release_file,
+ .fsync = ext2_fsync,
+ .get_unmapped_area = thp_get_unmapped_area,
+ .splice_read = generic_file_splice_read,
+ .splice_write = iter_file_splice_write,
+};
+
+const struct inode_operations ext2_file_inode_operations = {
+#ifdef CONFIG_EXT2_FS_XATTR
+ .listxattr = ext2_listxattr,
+#endif
+ .setattr = ext2_setattr,
+ .get_acl = ext2_get_acl,
+ .set_acl = ext2_set_acl,
+ .fiemap = ext2_fiemap,
+};
diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c
new file mode 100644
index 0000000..5c3d7b7
--- /dev/null
+++ b/fs/ext2/ialloc.c
@@ -0,0 +1,683 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/ialloc.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * BSD ufs-inspired inode and directory allocation by
+ * Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
+ * Big-endian to little-endian byte-swapping/bitmaps by
+ * David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include <linux/quotaops.h>
+#include <linux/sched.h>
+#include <linux/backing-dev.h>
+#include <linux/buffer_head.h>
+#include <linux/random.h>
+#include "ext2.h"
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * ialloc.c contains the inodes allocation and deallocation routines
+ */
+
+/*
+ * The free inodes are managed by bitmaps. A file system contains several
+ * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
+ * block for inodes, N blocks for the inode table and data blocks.
+ *
+ * The file system contains group descriptors which are located after the
+ * super block. Each descriptor contains the number of the bitmap block and
+ * the free blocks count in the block.
+ */
+
+
+/*
+ * Read the inode allocation bitmap for a given block_group, reading
+ * into the specified slot in the superblock's bitmap cache.
+ *
+ * Return buffer_head of bitmap on success or NULL.
+ */
+static struct buffer_head *
+read_inode_bitmap(struct super_block * sb, unsigned long block_group)
+{
+ struct ext2_group_desc *desc;
+ struct buffer_head *bh = NULL;
+
+ desc = ext2_get_group_desc(sb, block_group, NULL);
+ if (!desc)
+ goto error_out;
+
+ bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap));
+ if (!bh)
+ ext2_error(sb, "read_inode_bitmap",
+ "Cannot read inode bitmap - "
+ "block_group = %lu, inode_bitmap = %u",
+ block_group, le32_to_cpu(desc->bg_inode_bitmap));
+error_out:
+ return bh;
+}
+
+static void ext2_release_inode(struct super_block *sb, int group, int dir)
+{
+ struct ext2_group_desc * desc;
+ struct buffer_head *bh;
+
+ desc = ext2_get_group_desc(sb, group, &bh);
+ if (!desc) {
+ ext2_error(sb, "ext2_release_inode",
+ "can't get descriptor for group %d", group);
+ return;
+ }
+
+ spin_lock(sb_bgl_lock(EXT2_SB(sb), group));
+ le16_add_cpu(&desc->bg_free_inodes_count, 1);
+ if (dir)
+ le16_add_cpu(&desc->bg_used_dirs_count, -1);
+ spin_unlock(sb_bgl_lock(EXT2_SB(sb), group));
+ if (dir)
+ percpu_counter_dec(&EXT2_SB(sb)->s_dirs_counter);
+ mark_buffer_dirty(bh);
+}
+
+/*
+ * NOTE! When we get the inode, we're the only people
+ * that have access to it, and as such there are no
+ * race conditions we have to worry about. The inode
+ * is not on the hash-lists, and it cannot be reached
+ * through the filesystem because the directory entry
+ * has been deleted earlier.
+ *
+ * HOWEVER: we must make sure that we get no aliases,
+ * which means that we have to call "clear_inode()"
+ * _before_ we mark the inode not in use in the inode
+ * bitmaps. Otherwise a newly created file might use
+ * the same inode number (not actually the same pointer
+ * though), and then we'd have two inodes sharing the
+ * same inode number and space on the harddisk.
+ */
+void ext2_free_inode (struct inode * inode)
+{
+ struct super_block * sb = inode->i_sb;
+ int is_directory;
+ unsigned long ino;
+ struct buffer_head *bitmap_bh;
+ unsigned long block_group;
+ unsigned long bit;
+ struct ext2_super_block * es;
+
+ ino = inode->i_ino;
+ ext2_debug ("freeing inode %lu\n", ino);
+
+ /*
+ * Note: we must free any quota before locking the superblock,
+ * as writing the quota to disk may need the lock as well.
+ */
+ /* Quota is already initialized in iput() */
+ dquot_free_inode(inode);
+ dquot_drop(inode);
+
+ es = EXT2_SB(sb)->s_es;
+ is_directory = S_ISDIR(inode->i_mode);
+
+ if (ino < EXT2_FIRST_INO(sb) ||
+ ino > le32_to_cpu(es->s_inodes_count)) {
+ ext2_error (sb, "ext2_free_inode",
+ "reserved or nonexistent inode %lu", ino);
+ return;
+ }
+ block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
+ bit = (ino - 1) % EXT2_INODES_PER_GROUP(sb);
+ bitmap_bh = read_inode_bitmap(sb, block_group);
+ if (!bitmap_bh)
+ return;
+
+ /* Ok, now we can actually update the inode bitmaps.. */
+ if (!ext2_clear_bit_atomic(sb_bgl_lock(EXT2_SB(sb), block_group),
+ bit, (void *) bitmap_bh->b_data))
+ ext2_error (sb, "ext2_free_inode",
+ "bit already cleared for inode %lu", ino);
+ else
+ ext2_release_inode(sb, block_group, is_directory);
+ mark_buffer_dirty(bitmap_bh);
+ if (sb->s_flags & SB_SYNCHRONOUS)
+ sync_dirty_buffer(bitmap_bh);
+
+ brelse(bitmap_bh);
+}
+
+/*
+ * We perform asynchronous prereading of the new inode's inode block when
+ * we create the inode, in the expectation that the inode will be written
+ * back soon. There are two reasons:
+ *
+ * - When creating a large number of files, the async prereads will be
+ * nicely merged into large reads
+ * - When writing out a large number of inodes, we don't need to keep on
+ * stalling the writes while we read the inode block.
+ *
+ * FIXME: ext2_get_group_desc() needs to be simplified.
+ */
+static void ext2_preread_inode(struct inode *inode)
+{
+ unsigned long block_group;
+ unsigned long offset;
+ unsigned long block;
+ struct ext2_group_desc * gdp;
+ struct backing_dev_info *bdi;
+
+ bdi = inode_to_bdi(inode);
+ if (bdi_read_congested(bdi))
+ return;
+ if (bdi_write_congested(bdi))
+ return;
+
+ block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
+ gdp = ext2_get_group_desc(inode->i_sb, block_group, NULL);
+ if (gdp == NULL)
+ return;
+
+ /*
+ * Figure out the offset within the block group inode table
+ */
+ offset = ((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb)) *
+ EXT2_INODE_SIZE(inode->i_sb);
+ block = le32_to_cpu(gdp->bg_inode_table) +
+ (offset >> EXT2_BLOCK_SIZE_BITS(inode->i_sb));
+ sb_breadahead(inode->i_sb, block);
+}
+
+/*
+ * There are two policies for allocating an inode. If the new inode is
+ * a directory, then a forward search is made for a block group with both
+ * free space and a low directory-to-inode ratio; if that fails, then of
+ * the groups with above-average free space, that group with the fewest
+ * directories already is chosen.
+ *
+ * For other inodes, search forward from the parent directory\'s block
+ * group to find a free inode.
+ */
+static int find_group_dir(struct super_block *sb, struct inode *parent)
+{
+ int ngroups = EXT2_SB(sb)->s_groups_count;
+ int avefreei = ext2_count_free_inodes(sb) / ngroups;
+ struct ext2_group_desc *desc, *best_desc = NULL;
+ int group, best_group = -1;
+
+ for (group = 0; group < ngroups; group++) {
+ desc = ext2_get_group_desc (sb, group, NULL);
+ if (!desc || !desc->bg_free_inodes_count)
+ continue;
+ if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
+ continue;
+ if (!best_desc ||
+ (le16_to_cpu(desc->bg_free_blocks_count) >
+ le16_to_cpu(best_desc->bg_free_blocks_count))) {
+ best_group = group;
+ best_desc = desc;
+ }
+ }
+ if (!best_desc)
+ return -1;
+
+ return best_group;
+}
+
+/*
+ * Orlov's allocator for directories.
+ *
+ * We always try to spread first-level directories.
+ *
+ * If there are blockgroups with both free inodes and free blocks counts
+ * not worse than average we return one with smallest directory count.
+ * Otherwise we simply return a random group.
+ *
+ * For the rest rules look so:
+ *
+ * It's OK to put directory into a group unless
+ * it has too many directories already (max_dirs) or
+ * it has too few free inodes left (min_inodes) or
+ * it has too few free blocks left (min_blocks) or
+ * it's already running too large debt (max_debt).
+ * Parent's group is preferred, if it doesn't satisfy these
+ * conditions we search cyclically through the rest. If none
+ * of the groups look good we just look for a group with more
+ * free inodes than average (starting at parent's group).
+ *
+ * Debt is incremented each time we allocate a directory and decremented
+ * when we allocate an inode, within 0--255.
+ */
+
+#define INODE_COST 64
+#define BLOCK_COST 256
+
+static int find_group_orlov(struct super_block *sb, struct inode *parent)
+{
+ int parent_group = EXT2_I(parent)->i_block_group;
+ struct ext2_sb_info *sbi = EXT2_SB(sb);
+ struct ext2_super_block *es = sbi->s_es;
+ int ngroups = sbi->s_groups_count;
+ int inodes_per_group = EXT2_INODES_PER_GROUP(sb);
+ int freei;
+ int avefreei;
+ int free_blocks;
+ int avefreeb;
+ int blocks_per_dir;
+ int ndirs;
+ int max_debt, max_dirs, min_blocks, min_inodes;
+ int group = -1, i;
+ struct ext2_group_desc *desc;
+
+ freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
+ avefreei = freei / ngroups;
+ free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
+ avefreeb = free_blocks / ngroups;
+ ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
+
+ if ((parent == d_inode(sb->s_root)) ||
+ (EXT2_I(parent)->i_flags & EXT2_TOPDIR_FL)) {
+ struct ext2_group_desc *best_desc = NULL;
+ int best_ndir = inodes_per_group;
+ int best_group = -1;
+
+ group = prandom_u32();
+ parent_group = (unsigned)group % ngroups;
+ for (i = 0; i < ngroups; i++) {
+ group = (parent_group + i) % ngroups;
+ desc = ext2_get_group_desc (sb, group, NULL);
+ if (!desc || !desc->bg_free_inodes_count)
+ continue;
+ if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
+ continue;
+ if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
+ continue;
+ if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
+ continue;
+ best_group = group;
+ best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
+ best_desc = desc;
+ }
+ if (best_group >= 0) {
+ desc = best_desc;
+ group = best_group;
+ goto found;
+ }
+ goto fallback;
+ }
+
+ if (ndirs == 0)
+ ndirs = 1; /* percpu_counters are approximate... */
+
+ blocks_per_dir = (le32_to_cpu(es->s_blocks_count)-free_blocks) / ndirs;
+
+ max_dirs = ndirs / ngroups + inodes_per_group / 16;
+ min_inodes = avefreei - inodes_per_group / 4;
+ min_blocks = avefreeb - EXT2_BLOCKS_PER_GROUP(sb) / 4;
+
+ max_debt = EXT2_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, BLOCK_COST);
+ if (max_debt * INODE_COST > inodes_per_group)
+ max_debt = inodes_per_group / INODE_COST;
+ if (max_debt > 255)
+ max_debt = 255;
+ if (max_debt == 0)
+ max_debt = 1;
+
+ for (i = 0; i < ngroups; i++) {
+ group = (parent_group + i) % ngroups;
+ desc = ext2_get_group_desc (sb, group, NULL);
+ if (!desc || !desc->bg_free_inodes_count)
+ continue;
+ if (sbi->s_debts[group] >= max_debt)
+ continue;
+ if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
+ continue;
+ if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
+ continue;
+ if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
+ continue;
+ goto found;
+ }
+
+fallback:
+ for (i = 0; i < ngroups; i++) {
+ group = (parent_group + i) % ngroups;
+ desc = ext2_get_group_desc (sb, group, NULL);
+ if (!desc || !desc->bg_free_inodes_count)
+ continue;
+ if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
+ goto found;
+ }
+
+ if (avefreei) {
+ /*
+ * The free-inodes counter is approximate, and for really small
+ * filesystems the above test can fail to find any blockgroups
+ */
+ avefreei = 0;
+ goto fallback;
+ }
+
+ return -1;
+
+found:
+ return group;
+}
+
+static int find_group_other(struct super_block *sb, struct inode *parent)
+{
+ int parent_group = EXT2_I(parent)->i_block_group;
+ int ngroups = EXT2_SB(sb)->s_groups_count;
+ struct ext2_group_desc *desc;
+ int group, i;
+
+ /*
+ * Try to place the inode in its parent directory
+ */
+ group = parent_group;
+ desc = ext2_get_group_desc (sb, group, NULL);
+ if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
+ le16_to_cpu(desc->bg_free_blocks_count))
+ goto found;
+
+ /*
+ * We're going to place this inode in a different blockgroup from its
+ * parent. We want to cause files in a common directory to all land in
+ * the same blockgroup. But we want files which are in a different
+ * directory which shares a blockgroup with our parent to land in a
+ * different blockgroup.
+ *
+ * So add our directory's i_ino into the starting point for the hash.
+ */
+ group = (group + parent->i_ino) % ngroups;
+
+ /*
+ * Use a quadratic hash to find a group with a free inode and some
+ * free blocks.
+ */
+ for (i = 1; i < ngroups; i <<= 1) {
+ group += i;
+ if (group >= ngroups)
+ group -= ngroups;
+ desc = ext2_get_group_desc (sb, group, NULL);
+ if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
+ le16_to_cpu(desc->bg_free_blocks_count))
+ goto found;
+ }
+
+ /*
+ * That failed: try linear search for a free inode, even if that group
+ * has no free blocks.
+ */
+ group = parent_group;
+ for (i = 0; i < ngroups; i++) {
+ if (++group >= ngroups)
+ group = 0;
+ desc = ext2_get_group_desc (sb, group, NULL);
+ if (desc && le16_to_cpu(desc->bg_free_inodes_count))
+ goto found;
+ }
+
+ return -1;
+
+found:
+ return group;
+}
+
+struct inode *ext2_new_inode(struct inode *dir, umode_t mode,
+ const struct qstr *qstr)
+{
+ struct super_block *sb;
+ struct buffer_head *bitmap_bh = NULL;
+ struct buffer_head *bh2;
+ int group, i;
+ ino_t ino = 0;
+ struct inode * inode;
+ struct ext2_group_desc *gdp;
+ struct ext2_super_block *es;
+ struct ext2_inode_info *ei;
+ struct ext2_sb_info *sbi;
+ int err;
+
+ sb = dir->i_sb;
+ inode = new_inode(sb);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ ei = EXT2_I(inode);
+ sbi = EXT2_SB(sb);
+ es = sbi->s_es;
+ if (S_ISDIR(mode)) {
+ if (test_opt(sb, OLDALLOC))
+ group = find_group_dir(sb, dir);
+ else
+ group = find_group_orlov(sb, dir);
+ } else
+ group = find_group_other(sb, dir);
+
+ if (group == -1) {
+ err = -ENOSPC;
+ goto fail;
+ }
+
+ for (i = 0; i < sbi->s_groups_count; i++) {
+ gdp = ext2_get_group_desc(sb, group, &bh2);
+ if (!gdp) {
+ if (++group == sbi->s_groups_count)
+ group = 0;
+ continue;
+ }
+ brelse(bitmap_bh);
+ bitmap_bh = read_inode_bitmap(sb, group);
+ if (!bitmap_bh) {
+ err = -EIO;
+ goto fail;
+ }
+ ino = 0;
+
+repeat_in_this_group:
+ ino = ext2_find_next_zero_bit((unsigned long *)bitmap_bh->b_data,
+ EXT2_INODES_PER_GROUP(sb), ino);
+ if (ino >= EXT2_INODES_PER_GROUP(sb)) {
+ /*
+ * Rare race: find_group_xx() decided that there were
+ * free inodes in this group, but by the time we tried
+ * to allocate one, they're all gone. This can also
+ * occur because the counters which find_group_orlov()
+ * uses are approximate. So just go and search the
+ * next block group.
+ */
+ if (++group == sbi->s_groups_count)
+ group = 0;
+ continue;
+ }
+ if (ext2_set_bit_atomic(sb_bgl_lock(sbi, group),
+ ino, bitmap_bh->b_data)) {
+ /* we lost this inode */
+ if (++ino >= EXT2_INODES_PER_GROUP(sb)) {
+ /* this group is exhausted, try next group */
+ if (++group == sbi->s_groups_count)
+ group = 0;
+ continue;
+ }
+ /* try to find free inode in the same group */
+ goto repeat_in_this_group;
+ }
+ goto got;
+ }
+
+ /*
+ * Scanned all blockgroups.
+ */
+ err = -ENOSPC;
+ goto fail;
+got:
+ mark_buffer_dirty(bitmap_bh);
+ if (sb->s_flags & SB_SYNCHRONOUS)
+ sync_dirty_buffer(bitmap_bh);
+ brelse(bitmap_bh);
+
+ ino += group * EXT2_INODES_PER_GROUP(sb) + 1;
+ if (ino < EXT2_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
+ ext2_error (sb, "ext2_new_inode",
+ "reserved inode or inode > inodes count - "
+ "block_group = %d,inode=%lu", group,
+ (unsigned long) ino);
+ err = -EIO;
+ goto fail;
+ }
+
+ percpu_counter_add(&sbi->s_freeinodes_counter, -1);
+ if (S_ISDIR(mode))
+ percpu_counter_inc(&sbi->s_dirs_counter);
+
+ spin_lock(sb_bgl_lock(sbi, group));
+ le16_add_cpu(&gdp->bg_free_inodes_count, -1);
+ if (S_ISDIR(mode)) {
+ if (sbi->s_debts[group] < 255)
+ sbi->s_debts[group]++;
+ le16_add_cpu(&gdp->bg_used_dirs_count, 1);
+ } else {
+ if (sbi->s_debts[group])
+ sbi->s_debts[group]--;
+ }
+ spin_unlock(sb_bgl_lock(sbi, group));
+
+ mark_buffer_dirty(bh2);
+ if (test_opt(sb, GRPID)) {
+ inode->i_mode = mode;
+ inode->i_uid = current_fsuid();
+ inode->i_gid = dir->i_gid;
+ } else
+ inode_init_owner(inode, dir, mode);
+
+ inode->i_ino = ino;
+ inode->i_blocks = 0;
+ inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
+ memset(ei->i_data, 0, sizeof(ei->i_data));
+ ei->i_flags =
+ ext2_mask_flags(mode, EXT2_I(dir)->i_flags & EXT2_FL_INHERITED);
+ ei->i_faddr = 0;
+ ei->i_frag_no = 0;
+ ei->i_frag_size = 0;
+ ei->i_file_acl = 0;
+ ei->i_dir_acl = 0;
+ ei->i_dtime = 0;
+ ei->i_block_alloc_info = NULL;
+ ei->i_block_group = group;
+ ei->i_dir_start_lookup = 0;
+ ei->i_state = EXT2_STATE_NEW;
+ ext2_set_inode_flags(inode);
+ spin_lock(&sbi->s_next_gen_lock);
+ inode->i_generation = sbi->s_next_generation++;
+ spin_unlock(&sbi->s_next_gen_lock);
+ if (insert_inode_locked(inode) < 0) {
+ ext2_error(sb, "ext2_new_inode",
+ "inode number already in use - inode=%lu",
+ (unsigned long) ino);
+ err = -EIO;
+ goto fail;
+ }
+
+ err = dquot_initialize(inode);
+ if (err)
+ goto fail_drop;
+
+ err = dquot_alloc_inode(inode);
+ if (err)
+ goto fail_drop;
+
+ err = ext2_init_acl(inode, dir);
+ if (err)
+ goto fail_free_drop;
+
+ err = ext2_init_security(inode, dir, qstr);
+ if (err)
+ goto fail_free_drop;
+
+ mark_inode_dirty(inode);
+ ext2_debug("allocating inode %lu\n", inode->i_ino);
+ ext2_preread_inode(inode);
+ return inode;
+
+fail_free_drop:
+ dquot_free_inode(inode);
+
+fail_drop:
+ dquot_drop(inode);
+ inode->i_flags |= S_NOQUOTA;
+ clear_nlink(inode);
+ discard_new_inode(inode);
+ return ERR_PTR(err);
+
+fail:
+ make_bad_inode(inode);
+ iput(inode);
+ return ERR_PTR(err);
+}
+
+unsigned long ext2_count_free_inodes (struct super_block * sb)
+{
+ struct ext2_group_desc *desc;
+ unsigned long desc_count = 0;
+ int i;
+
+#ifdef EXT2FS_DEBUG
+ struct ext2_super_block *es;
+ unsigned long bitmap_count = 0;
+ struct buffer_head *bitmap_bh = NULL;
+
+ es = EXT2_SB(sb)->s_es;
+ for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
+ unsigned x;
+
+ desc = ext2_get_group_desc (sb, i, NULL);
+ if (!desc)
+ continue;
+ desc_count += le16_to_cpu(desc->bg_free_inodes_count);
+ brelse(bitmap_bh);
+ bitmap_bh = read_inode_bitmap(sb, i);
+ if (!bitmap_bh)
+ continue;
+
+ x = ext2_count_free(bitmap_bh, EXT2_INODES_PER_GROUP(sb) / 8);
+ printk("group %d: stored = %d, counted = %u\n",
+ i, le16_to_cpu(desc->bg_free_inodes_count), x);
+ bitmap_count += x;
+ }
+ brelse(bitmap_bh);
+ printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n",
+ (unsigned long)
+ percpu_counter_read(&EXT2_SB(sb)->s_freeinodes_counter),
+ desc_count, bitmap_count);
+ return desc_count;
+#else
+ for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
+ desc = ext2_get_group_desc (sb, i, NULL);
+ if (!desc)
+ continue;
+ desc_count += le16_to_cpu(desc->bg_free_inodes_count);
+ }
+ return desc_count;
+#endif
+}
+
+/* Called at mount-time, super-block is locked */
+unsigned long ext2_count_dirs (struct super_block * sb)
+{
+ unsigned long count = 0;
+ int i;
+
+ for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
+ struct ext2_group_desc *gdp = ext2_get_group_desc (sb, i, NULL);
+ if (!gdp)
+ continue;
+ count += le16_to_cpu(gdp->bg_used_dirs_count);
+ }
+ return count;
+}
+
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
new file mode 100644
index 0000000..e4bb938
--- /dev/null
+++ b/fs/ext2/inode.c
@@ -0,0 +1,1669 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/inode.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * from
+ *
+ * linux/fs/minix/inode.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * Goal-directed block allocation by Stephen Tweedie
+ * (sct@dcs.ed.ac.uk), 1993, 1998
+ * Big-endian to little-endian byte-swapping/bitmaps by
+ * David S. Miller (davem@caip.rutgers.edu), 1995
+ * 64-bit file support on 64-bit platforms by Jakub Jelinek
+ * (jj@sunsite.ms.mff.cuni.cz)
+ *
+ * Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000
+ */
+
+#include <linux/time.h>
+#include <linux/highuid.h>
+#include <linux/pagemap.h>
+#include <linux/dax.h>
+#include <linux/blkdev.h>
+#include <linux/quotaops.h>
+#include <linux/writeback.h>
+#include <linux/buffer_head.h>
+#include <linux/mpage.h>
+#include <linux/fiemap.h>
+#include <linux/iomap.h>
+#include <linux/namei.h>
+#include <linux/uio.h>
+#include "ext2.h"
+#include "acl.h"
+#include "xattr.h"
+
+static int __ext2_write_inode(struct inode *inode, int do_sync);
+
+/*
+ * Test whether an inode is a fast symlink.
+ */
+static inline int ext2_inode_is_fast_symlink(struct inode *inode)
+{
+ int ea_blocks = EXT2_I(inode)->i_file_acl ?
+ (inode->i_sb->s_blocksize >> 9) : 0;
+
+ return (S_ISLNK(inode->i_mode) &&
+ inode->i_blocks - ea_blocks == 0);
+}
+
+static void ext2_truncate_blocks(struct inode *inode, loff_t offset);
+
+static void ext2_write_failed(struct address_space *mapping, loff_t to)
+{
+ struct inode *inode = mapping->host;
+
+ if (to > inode->i_size) {
+ truncate_pagecache(inode, inode->i_size);
+ ext2_truncate_blocks(inode, inode->i_size);
+ }
+}
+
+/*
+ * Called at the last iput() if i_nlink is zero.
+ */
+void ext2_evict_inode(struct inode * inode)
+{
+ struct ext2_block_alloc_info *rsv;
+ int want_delete = 0;
+
+ if (!inode->i_nlink && !is_bad_inode(inode)) {
+ want_delete = 1;
+ dquot_initialize(inode);
+ } else {
+ dquot_drop(inode);
+ }
+
+ truncate_inode_pages_final(&inode->i_data);
+
+ if (want_delete) {
+ sb_start_intwrite(inode->i_sb);
+ /* set dtime */
+ EXT2_I(inode)->i_dtime = ktime_get_real_seconds();
+ mark_inode_dirty(inode);
+ __ext2_write_inode(inode, inode_needs_sync(inode));
+ /* truncate to 0 */
+ inode->i_size = 0;
+ if (inode->i_blocks)
+ ext2_truncate_blocks(inode, 0);
+ ext2_xattr_delete_inode(inode);
+ }
+
+ invalidate_inode_buffers(inode);
+ clear_inode(inode);
+
+ ext2_discard_reservation(inode);
+ rsv = EXT2_I(inode)->i_block_alloc_info;
+ EXT2_I(inode)->i_block_alloc_info = NULL;
+ if (unlikely(rsv))
+ kfree(rsv);
+
+ if (want_delete) {
+ ext2_free_inode(inode);
+ sb_end_intwrite(inode->i_sb);
+ }
+}
+
+typedef struct {
+ __le32 *p;
+ __le32 key;
+ struct buffer_head *bh;
+} Indirect;
+
+static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
+{
+ p->key = *(p->p = v);
+ p->bh = bh;
+}
+
+static inline int verify_chain(Indirect *from, Indirect *to)
+{
+ while (from <= to && from->key == *from->p)
+ from++;
+ return (from > to);
+}
+
+/**
+ * ext2_block_to_path - parse the block number into array of offsets
+ * @inode: inode in question (we are only interested in its superblock)
+ * @i_block: block number to be parsed
+ * @offsets: array to store the offsets in
+ * @boundary: set this non-zero if the referred-to block is likely to be
+ * followed (on disk) by an indirect block.
+ * To store the locations of file's data ext2 uses a data structure common
+ * for UNIX filesystems - tree of pointers anchored in the inode, with
+ * data blocks at leaves and indirect blocks in intermediate nodes.
+ * This function translates the block number into path in that tree -
+ * return value is the path length and @offsets[n] is the offset of
+ * pointer to (n+1)th node in the nth one. If @block is out of range
+ * (negative or too large) warning is printed and zero returned.
+ *
+ * Note: function doesn't find node addresses, so no IO is needed. All
+ * we need to know is the capacity of indirect blocks (taken from the
+ * inode->i_sb).
+ */
+
+/*
+ * Portability note: the last comparison (check that we fit into triple
+ * indirect block) is spelled differently, because otherwise on an
+ * architecture with 32-bit longs and 8Kb pages we might get into trouble
+ * if our filesystem had 8Kb blocks. We might use long long, but that would
+ * kill us on x86. Oh, well, at least the sign propagation does not matter -
+ * i_block would have to be negative in the very beginning, so we would not
+ * get there at all.
+ */
+
+static int ext2_block_to_path(struct inode *inode,
+ long i_block, int offsets[4], int *boundary)
+{
+ int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb);
+ int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb);
+ const long direct_blocks = EXT2_NDIR_BLOCKS,
+ indirect_blocks = ptrs,
+ double_blocks = (1 << (ptrs_bits * 2));
+ int n = 0;
+ int final = 0;
+
+ if (i_block < 0) {
+ ext2_msg(inode->i_sb, KERN_WARNING,
+ "warning: %s: block < 0", __func__);
+ } else if (i_block < direct_blocks) {
+ offsets[n++] = i_block;
+ final = direct_blocks;
+ } else if ( (i_block -= direct_blocks) < indirect_blocks) {
+ offsets[n++] = EXT2_IND_BLOCK;
+ offsets[n++] = i_block;
+ final = ptrs;
+ } else if ((i_block -= indirect_blocks) < double_blocks) {
+ offsets[n++] = EXT2_DIND_BLOCK;
+ offsets[n++] = i_block >> ptrs_bits;
+ offsets[n++] = i_block & (ptrs - 1);
+ final = ptrs;
+ } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
+ offsets[n++] = EXT2_TIND_BLOCK;
+ offsets[n++] = i_block >> (ptrs_bits * 2);
+ offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
+ offsets[n++] = i_block & (ptrs - 1);
+ final = ptrs;
+ } else {
+ ext2_msg(inode->i_sb, KERN_WARNING,
+ "warning: %s: block is too big", __func__);
+ }
+ if (boundary)
+ *boundary = final - 1 - (i_block & (ptrs - 1));
+
+ return n;
+}
+
+/**
+ * ext2_get_branch - read the chain of indirect blocks leading to data
+ * @inode: inode in question
+ * @depth: depth of the chain (1 - direct pointer, etc.)
+ * @offsets: offsets of pointers in inode/indirect blocks
+ * @chain: place to store the result
+ * @err: here we store the error value
+ *
+ * Function fills the array of triples <key, p, bh> and returns %NULL
+ * if everything went OK or the pointer to the last filled triple
+ * (incomplete one) otherwise. Upon the return chain[i].key contains
+ * the number of (i+1)-th block in the chain (as it is stored in memory,
+ * i.e. little-endian 32-bit), chain[i].p contains the address of that
+ * number (it points into struct inode for i==0 and into the bh->b_data
+ * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
+ * block for i>0 and NULL for i==0. In other words, it holds the block
+ * numbers of the chain, addresses they were taken from (and where we can
+ * verify that chain did not change) and buffer_heads hosting these
+ * numbers.
+ *
+ * Function stops when it stumbles upon zero pointer (absent block)
+ * (pointer to last triple returned, *@err == 0)
+ * or when it gets an IO error reading an indirect block
+ * (ditto, *@err == -EIO)
+ * or when it notices that chain had been changed while it was reading
+ * (ditto, *@err == -EAGAIN)
+ * or when it reads all @depth-1 indirect blocks successfully and finds
+ * the whole chain, all way to the data (returns %NULL, *err == 0).
+ */
+static Indirect *ext2_get_branch(struct inode *inode,
+ int depth,
+ int *offsets,
+ Indirect chain[4],
+ int *err)
+{
+ struct super_block *sb = inode->i_sb;
+ Indirect *p = chain;
+ struct buffer_head *bh;
+
+ *err = 0;
+ /* i_data is not going away, no lock needed */
+ add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets);
+ if (!p->key)
+ goto no_block;
+ while (--depth) {
+ bh = sb_bread(sb, le32_to_cpu(p->key));
+ if (!bh)
+ goto failure;
+ read_lock(&EXT2_I(inode)->i_meta_lock);
+ if (!verify_chain(chain, p))
+ goto changed;
+ add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
+ read_unlock(&EXT2_I(inode)->i_meta_lock);
+ if (!p->key)
+ goto no_block;
+ }
+ return NULL;
+
+changed:
+ read_unlock(&EXT2_I(inode)->i_meta_lock);
+ brelse(bh);
+ *err = -EAGAIN;
+ goto no_block;
+failure:
+ *err = -EIO;
+no_block:
+ return p;
+}
+
+/**
+ * ext2_find_near - find a place for allocation with sufficient locality
+ * @inode: owner
+ * @ind: descriptor of indirect block.
+ *
+ * This function returns the preferred place for block allocation.
+ * It is used when heuristic for sequential allocation fails.
+ * Rules are:
+ * + if there is a block to the left of our position - allocate near it.
+ * + if pointer will live in indirect block - allocate near that block.
+ * + if pointer will live in inode - allocate in the same cylinder group.
+ *
+ * In the latter case we colour the starting block by the callers PID to
+ * prevent it from clashing with concurrent allocations for a different inode
+ * in the same block group. The PID is used here so that functionally related
+ * files will be close-by on-disk.
+ *
+ * Caller must make sure that @ind is valid and will stay that way.
+ */
+
+static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind)
+{
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
+ __le32 *p;
+ ext2_fsblk_t bg_start;
+ ext2_fsblk_t colour;
+
+ /* Try to find previous block */
+ for (p = ind->p - 1; p >= start; p--)
+ if (*p)
+ return le32_to_cpu(*p);
+
+ /* No such thing, so let's try location of indirect block */
+ if (ind->bh)
+ return ind->bh->b_blocknr;
+
+ /*
+ * It is going to be referred from inode itself? OK, just put it into
+ * the same cylinder group then.
+ */
+ bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group);
+ colour = (current->pid % 16) *
+ (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16);
+ return bg_start + colour;
+}
+
+/**
+ * ext2_find_goal - find a preferred place for allocation.
+ * @inode: owner
+ * @block: block we want
+ * @partial: pointer to the last triple within a chain
+ *
+ * Returns preferred place for a block (the goal).
+ */
+
+static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block,
+ Indirect *partial)
+{
+ struct ext2_block_alloc_info *block_i;
+
+ block_i = EXT2_I(inode)->i_block_alloc_info;
+
+ /*
+ * try the heuristic for sequential allocation,
+ * failing that at least try to get decent locality.
+ */
+ if (block_i && (block == block_i->last_alloc_logical_block + 1)
+ && (block_i->last_alloc_physical_block != 0)) {
+ return block_i->last_alloc_physical_block + 1;
+ }
+
+ return ext2_find_near(inode, partial);
+}
+
+/**
+ * ext2_blks_to_allocate: Look up the block map and count the number
+ * of direct blocks need to be allocated for the given branch.
+ *
+ * @branch: chain of indirect blocks
+ * @k: number of blocks need for indirect blocks
+ * @blks: number of data blocks to be mapped.
+ * @blocks_to_boundary: the offset in the indirect block
+ *
+ * return the total number of blocks to be allocate, including the
+ * direct and indirect blocks.
+ */
+static int
+ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks,
+ int blocks_to_boundary)
+{
+ unsigned long count = 0;
+
+ /*
+ * Simple case, [t,d]Indirect block(s) has not allocated yet
+ * then it's clear blocks on that path have not allocated
+ */
+ if (k > 0) {
+ /* right now don't hanel cross boundary allocation */
+ if (blks < blocks_to_boundary + 1)
+ count += blks;
+ else
+ count += blocks_to_boundary + 1;
+ return count;
+ }
+
+ count++;
+ while (count < blks && count <= blocks_to_boundary
+ && le32_to_cpu(*(branch[0].p + count)) == 0) {
+ count++;
+ }
+ return count;
+}
+
+/**
+ * ext2_alloc_blocks: multiple allocate blocks needed for a branch
+ * @indirect_blks: the number of blocks need to allocate for indirect
+ * blocks
+ *
+ * @new_blocks: on return it will store the new block numbers for
+ * the indirect blocks(if needed) and the first direct block,
+ * @blks: on return it will store the total number of allocated
+ * direct blocks
+ */
+static int ext2_alloc_blocks(struct inode *inode,
+ ext2_fsblk_t goal, int indirect_blks, int blks,
+ ext2_fsblk_t new_blocks[4], int *err)
+{
+ int target, i;
+ unsigned long count = 0;
+ int index = 0;
+ ext2_fsblk_t current_block = 0;
+ int ret = 0;
+
+ /*
+ * Here we try to allocate the requested multiple blocks at once,
+ * on a best-effort basis.
+ * To build a branch, we should allocate blocks for
+ * the indirect blocks(if not allocated yet), and at least
+ * the first direct block of this branch. That's the
+ * minimum number of blocks need to allocate(required)
+ */
+ target = blks + indirect_blks;
+
+ while (1) {
+ count = target;
+ /* allocating blocks for indirect blocks and direct blocks */
+ current_block = ext2_new_blocks(inode,goal,&count,err);
+ if (*err)
+ goto failed_out;
+
+ target -= count;
+ /* allocate blocks for indirect blocks */
+ while (index < indirect_blks && count) {
+ new_blocks[index++] = current_block++;
+ count--;
+ }
+
+ if (count > 0)
+ break;
+ }
+
+ /* save the new block number for the first direct block */
+ new_blocks[index] = current_block;
+
+ /* total number of blocks allocated for direct blocks */
+ ret = count;
+ *err = 0;
+ return ret;
+failed_out:
+ for (i = 0; i <index; i++)
+ ext2_free_blocks(inode, new_blocks[i], 1);
+ if (index)
+ mark_inode_dirty(inode);
+ return ret;
+}
+
+/**
+ * ext2_alloc_branch - allocate and set up a chain of blocks.
+ * @inode: owner
+ * @num: depth of the chain (number of blocks to allocate)
+ * @offsets: offsets (in the blocks) to store the pointers to next.
+ * @branch: place to store the chain in.
+ *
+ * This function allocates @num blocks, zeroes out all but the last one,
+ * links them into chain and (if we are synchronous) writes them to disk.
+ * In other words, it prepares a branch that can be spliced onto the
+ * inode. It stores the information about that chain in the branch[], in
+ * the same format as ext2_get_branch() would do. We are calling it after
+ * we had read the existing part of chain and partial points to the last
+ * triple of that (one with zero ->key). Upon the exit we have the same
+ * picture as after the successful ext2_get_block(), except that in one
+ * place chain is disconnected - *branch->p is still zero (we did not
+ * set the last link), but branch->key contains the number that should
+ * be placed into *branch->p to fill that gap.
+ *
+ * If allocation fails we free all blocks we've allocated (and forget
+ * their buffer_heads) and return the error value the from failed
+ * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain
+ * as described above and return 0.
+ */
+
+static int ext2_alloc_branch(struct inode *inode,
+ int indirect_blks, int *blks, ext2_fsblk_t goal,
+ int *offsets, Indirect *branch)
+{
+ int blocksize = inode->i_sb->s_blocksize;
+ int i, n = 0;
+ int err = 0;
+ struct buffer_head *bh;
+ int num;
+ ext2_fsblk_t new_blocks[4];
+ ext2_fsblk_t current_block;
+
+ num = ext2_alloc_blocks(inode, goal, indirect_blks,
+ *blks, new_blocks, &err);
+ if (err)
+ return err;
+
+ branch[0].key = cpu_to_le32(new_blocks[0]);
+ /*
+ * metadata blocks and data blocks are allocated.
+ */
+ for (n = 1; n <= indirect_blks; n++) {
+ /*
+ * Get buffer_head for parent block, zero it out
+ * and set the pointer to new one, then send
+ * parent to disk.
+ */
+ bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
+ if (unlikely(!bh)) {
+ err = -ENOMEM;
+ goto failed;
+ }
+ branch[n].bh = bh;
+ lock_buffer(bh);
+ memset(bh->b_data, 0, blocksize);
+ branch[n].p = (__le32 *) bh->b_data + offsets[n];
+ branch[n].key = cpu_to_le32(new_blocks[n]);
+ *branch[n].p = branch[n].key;
+ if ( n == indirect_blks) {
+ current_block = new_blocks[n];
+ /*
+ * End of chain, update the last new metablock of
+ * the chain to point to the new allocated
+ * data blocks numbers
+ */
+ for (i=1; i < num; i++)
+ *(branch[n].p + i) = cpu_to_le32(++current_block);
+ }
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+ mark_buffer_dirty_inode(bh, inode);
+ /* We used to sync bh here if IS_SYNC(inode).
+ * But we now rely upon generic_write_sync()
+ * and b_inode_buffers. But not for directories.
+ */
+ if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
+ sync_dirty_buffer(bh);
+ }
+ *blks = num;
+ return err;
+
+failed:
+ for (i = 1; i < n; i++)
+ bforget(branch[i].bh);
+ for (i = 0; i < indirect_blks; i++)
+ ext2_free_blocks(inode, new_blocks[i], 1);
+ ext2_free_blocks(inode, new_blocks[i], num);
+ return err;
+}
+
+/**
+ * ext2_splice_branch - splice the allocated branch onto inode.
+ * @inode: owner
+ * @block: (logical) number of block we are adding
+ * @where: location of missing link
+ * @num: number of indirect blocks we are adding
+ * @blks: number of direct blocks we are adding
+ *
+ * This function fills the missing link and does all housekeeping needed in
+ * inode (->i_blocks, etc.). In case of success we end up with the full
+ * chain to new block and return 0.
+ */
+static void ext2_splice_branch(struct inode *inode,
+ long block, Indirect *where, int num, int blks)
+{
+ int i;
+ struct ext2_block_alloc_info *block_i;
+ ext2_fsblk_t current_block;
+
+ block_i = EXT2_I(inode)->i_block_alloc_info;
+
+ /* XXX LOCKING probably should have i_meta_lock ?*/
+ /* That's it */
+
+ *where->p = where->key;
+
+ /*
+ * Update the host buffer_head or inode to point to more just allocated
+ * direct blocks blocks
+ */
+ if (num == 0 && blks > 1) {
+ current_block = le32_to_cpu(where->key) + 1;
+ for (i = 1; i < blks; i++)
+ *(where->p + i ) = cpu_to_le32(current_block++);
+ }
+
+ /*
+ * update the most recently allocated logical & physical block
+ * in i_block_alloc_info, to assist find the proper goal block for next
+ * allocation
+ */
+ if (block_i) {
+ block_i->last_alloc_logical_block = block + blks - 1;
+ block_i->last_alloc_physical_block =
+ le32_to_cpu(where[num].key) + blks - 1;
+ }
+
+ /* We are done with atomic stuff, now do the rest of housekeeping */
+
+ /* had we spliced it onto indirect block? */
+ if (where->bh)
+ mark_buffer_dirty_inode(where->bh, inode);
+
+ inode->i_ctime = current_time(inode);
+ mark_inode_dirty(inode);
+}
+
+/*
+ * Allocation strategy is simple: if we have to allocate something, we will
+ * have to go the whole way to leaf. So let's do it before attaching anything
+ * to tree, set linkage between the newborn blocks, write them if sync is
+ * required, recheck the path, free and repeat if check fails, otherwise
+ * set the last missing link (that will protect us from any truncate-generated
+ * removals - all blocks on the path are immune now) and possibly force the
+ * write on the parent block.
+ * That has a nice additional property: no special recovery from the failed
+ * allocations is needed - we simply release blocks and do not touch anything
+ * reachable from inode.
+ *
+ * `handle' can be NULL if create == 0.
+ *
+ * return > 0, # of blocks mapped or allocated.
+ * return = 0, if plain lookup failed.
+ * return < 0, error case.
+ */
+static int ext2_get_blocks(struct inode *inode,
+ sector_t iblock, unsigned long maxblocks,
+ u32 *bno, bool *new, bool *boundary,
+ int create)
+{
+ int err;
+ int offsets[4];
+ Indirect chain[4];
+ Indirect *partial;
+ ext2_fsblk_t goal;
+ int indirect_blks;
+ int blocks_to_boundary = 0;
+ int depth;
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ int count = 0;
+ ext2_fsblk_t first_block = 0;
+
+ BUG_ON(maxblocks == 0);
+
+ depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
+
+ if (depth == 0)
+ return -EIO;
+
+ partial = ext2_get_branch(inode, depth, offsets, chain, &err);
+ /* Simplest case - block found, no allocation needed */
+ if (!partial) {
+ first_block = le32_to_cpu(chain[depth - 1].key);
+ count++;
+ /*map more blocks*/
+ while (count < maxblocks && count <= blocks_to_boundary) {
+ ext2_fsblk_t blk;
+
+ if (!verify_chain(chain, chain + depth - 1)) {
+ /*
+ * Indirect block might be removed by
+ * truncate while we were reading it.
+ * Handling of that case: forget what we've
+ * got now, go to reread.
+ */
+ err = -EAGAIN;
+ count = 0;
+ partial = chain + depth - 1;
+ break;
+ }
+ blk = le32_to_cpu(*(chain[depth-1].p + count));
+ if (blk == first_block + count)
+ count++;
+ else
+ break;
+ }
+ if (err != -EAGAIN)
+ goto got_it;
+ }
+
+ /* Next simple case - plain lookup or failed read of indirect block */
+ if (!create || err == -EIO)
+ goto cleanup;
+
+ mutex_lock(&ei->truncate_mutex);
+ /*
+ * If the indirect block is missing while we are reading
+ * the chain(ext2_get_branch() returns -EAGAIN err), or
+ * if the chain has been changed after we grab the semaphore,
+ * (either because another process truncated this branch, or
+ * another get_block allocated this branch) re-grab the chain to see if
+ * the request block has been allocated or not.
+ *
+ * Since we already block the truncate/other get_block
+ * at this point, we will have the current copy of the chain when we
+ * splice the branch into the tree.
+ */
+ if (err == -EAGAIN || !verify_chain(chain, partial)) {
+ while (partial > chain) {
+ brelse(partial->bh);
+ partial--;
+ }
+ partial = ext2_get_branch(inode, depth, offsets, chain, &err);
+ if (!partial) {
+ count++;
+ mutex_unlock(&ei->truncate_mutex);
+ if (err)
+ goto cleanup;
+ goto got_it;
+ }
+ }
+
+ /*
+ * Okay, we need to do block allocation. Lazily initialize the block
+ * allocation info here if necessary
+ */
+ if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
+ ext2_init_block_alloc_info(inode);
+
+ goal = ext2_find_goal(inode, iblock, partial);
+
+ /* the number of blocks need to allocate for [d,t]indirect blocks */
+ indirect_blks = (chain + depth) - partial - 1;
+ /*
+ * Next look up the indirect map to count the totoal number of
+ * direct blocks to allocate for this branch.
+ */
+ count = ext2_blks_to_allocate(partial, indirect_blks,
+ maxblocks, blocks_to_boundary);
+ /*
+ * XXX ???? Block out ext2_truncate while we alter the tree
+ */
+ err = ext2_alloc_branch(inode, indirect_blks, &count, goal,
+ offsets + (partial - chain), partial);
+
+ if (err) {
+ mutex_unlock(&ei->truncate_mutex);
+ goto cleanup;
+ }
+
+ if (IS_DAX(inode)) {
+ /*
+ * We must unmap blocks before zeroing so that writeback cannot
+ * overwrite zeros with stale data from block device page cache.
+ */
+ clean_bdev_aliases(inode->i_sb->s_bdev,
+ le32_to_cpu(chain[depth-1].key),
+ count);
+ /*
+ * block must be initialised before we put it in the tree
+ * so that it's not found by another thread before it's
+ * initialised
+ */
+ err = sb_issue_zeroout(inode->i_sb,
+ le32_to_cpu(chain[depth-1].key), count,
+ GFP_NOFS);
+ if (err) {
+ mutex_unlock(&ei->truncate_mutex);
+ goto cleanup;
+ }
+ }
+ *new = true;
+
+ ext2_splice_branch(inode, iblock, partial, indirect_blks, count);
+ mutex_unlock(&ei->truncate_mutex);
+got_it:
+ if (count > blocks_to_boundary)
+ *boundary = true;
+ err = count;
+ /* Clean up and exit */
+ partial = chain + depth - 1; /* the whole chain */
+cleanup:
+ while (partial > chain) {
+ brelse(partial->bh);
+ partial--;
+ }
+ if (err > 0)
+ *bno = le32_to_cpu(chain[depth-1].key);
+ return err;
+}
+
+int ext2_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
+ bool new = false, boundary = false;
+ u32 bno;
+ int ret;
+
+ ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary,
+ create);
+ if (ret <= 0)
+ return ret;
+
+ map_bh(bh_result, inode->i_sb, bno);
+ bh_result->b_size = (ret << inode->i_blkbits);
+ if (new)
+ set_buffer_new(bh_result);
+ if (boundary)
+ set_buffer_boundary(bh_result);
+ return 0;
+
+}
+
+#ifdef CONFIG_FS_DAX
+static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
+ unsigned flags, struct iomap *iomap)
+{
+ unsigned int blkbits = inode->i_blkbits;
+ unsigned long first_block = offset >> blkbits;
+ unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits;
+ struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb);
+ bool new = false, boundary = false;
+ u32 bno;
+ int ret;
+
+ ret = ext2_get_blocks(inode, first_block, max_blocks,
+ &bno, &new, &boundary, flags & IOMAP_WRITE);
+ if (ret < 0)
+ return ret;
+
+ iomap->flags = 0;
+ iomap->bdev = inode->i_sb->s_bdev;
+ iomap->offset = (u64)first_block << blkbits;
+ iomap->dax_dev = sbi->s_daxdev;
+
+ if (ret == 0) {
+ iomap->type = IOMAP_HOLE;
+ iomap->addr = IOMAP_NULL_ADDR;
+ iomap->length = 1 << blkbits;
+ } else {
+ iomap->type = IOMAP_MAPPED;
+ iomap->addr = (u64)bno << blkbits;
+ iomap->length = (u64)ret << blkbits;
+ iomap->flags |= IOMAP_F_MERGED;
+ }
+
+ if (new)
+ iomap->flags |= IOMAP_F_NEW;
+ return 0;
+}
+
+static int
+ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length,
+ ssize_t written, unsigned flags, struct iomap *iomap)
+{
+ if (iomap->type == IOMAP_MAPPED &&
+ written < length &&
+ (flags & IOMAP_WRITE))
+ ext2_write_failed(inode->i_mapping, offset + length);
+ return 0;
+}
+
+const struct iomap_ops ext2_iomap_ops = {
+ .iomap_begin = ext2_iomap_begin,
+ .iomap_end = ext2_iomap_end,
+};
+#else
+/* Define empty ops for !CONFIG_FS_DAX case to avoid ugly ifdefs */
+const struct iomap_ops ext2_iomap_ops;
+#endif /* CONFIG_FS_DAX */
+
+int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+ u64 start, u64 len)
+{
+ return generic_block_fiemap(inode, fieinfo, start, len,
+ ext2_get_block);
+}
+
+static int ext2_writepage(struct page *page, struct writeback_control *wbc)
+{
+ return block_write_full_page(page, ext2_get_block, wbc);
+}
+
+static int ext2_readpage(struct file *file, struct page *page)
+{
+ return mpage_readpage(page, ext2_get_block);
+}
+
+static int
+ext2_readpages(struct file *file, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ return mpage_readpages(mapping, pages, nr_pages, ext2_get_block);
+}
+
+static int
+ext2_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ int ret;
+
+ ret = block_write_begin(mapping, pos, len, flags, pagep,
+ ext2_get_block);
+ if (ret < 0)
+ ext2_write_failed(mapping, pos + len);
+ return ret;
+}
+
+static int ext2_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ int ret;
+
+ ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
+ if (ret < len)
+ ext2_write_failed(mapping, pos + len);
+ return ret;
+}
+
+static int
+ext2_nobh_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ int ret;
+
+ ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
+ ext2_get_block);
+ if (ret < 0)
+ ext2_write_failed(mapping, pos + len);
+ return ret;
+}
+
+static int ext2_nobh_writepage(struct page *page,
+ struct writeback_control *wbc)
+{
+ return nobh_writepage(page, ext2_get_block, wbc);
+}
+
+static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
+{
+ return generic_block_bmap(mapping,block,ext2_get_block);
+}
+
+static ssize_t
+ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+{
+ struct file *file = iocb->ki_filp;
+ struct address_space *mapping = file->f_mapping;
+ struct inode *inode = mapping->host;
+ size_t count = iov_iter_count(iter);
+ loff_t offset = iocb->ki_pos;
+ ssize_t ret;
+
+ ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block);
+ if (ret < 0 && iov_iter_rw(iter) == WRITE)
+ ext2_write_failed(mapping, offset + count);
+ return ret;
+}
+
+static int
+ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+ return mpage_writepages(mapping, wbc, ext2_get_block);
+}
+
+static int
+ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+ return dax_writeback_mapping_range(mapping,
+ mapping->host->i_sb->s_bdev, wbc);
+}
+
+const struct address_space_operations ext2_aops = {
+ .readpage = ext2_readpage,
+ .readpages = ext2_readpages,
+ .writepage = ext2_writepage,
+ .write_begin = ext2_write_begin,
+ .write_end = ext2_write_end,
+ .bmap = ext2_bmap,
+ .direct_IO = ext2_direct_IO,
+ .writepages = ext2_writepages,
+ .migratepage = buffer_migrate_page,
+ .is_partially_uptodate = block_is_partially_uptodate,
+ .error_remove_page = generic_error_remove_page,
+};
+
+const struct address_space_operations ext2_nobh_aops = {
+ .readpage = ext2_readpage,
+ .readpages = ext2_readpages,
+ .writepage = ext2_nobh_writepage,
+ .write_begin = ext2_nobh_write_begin,
+ .write_end = nobh_write_end,
+ .bmap = ext2_bmap,
+ .direct_IO = ext2_direct_IO,
+ .writepages = ext2_writepages,
+ .migratepage = buffer_migrate_page,
+ .error_remove_page = generic_error_remove_page,
+};
+
+static const struct address_space_operations ext2_dax_aops = {
+ .writepages = ext2_dax_writepages,
+ .direct_IO = noop_direct_IO,
+ .set_page_dirty = noop_set_page_dirty,
+ .invalidatepage = noop_invalidatepage,
+};
+
+/*
+ * Probably it should be a library function... search for first non-zero word
+ * or memcmp with zero_page, whatever is better for particular architecture.
+ * Linus?
+ */
+static inline int all_zeroes(__le32 *p, __le32 *q)
+{
+ while (p < q)
+ if (*p++)
+ return 0;
+ return 1;
+}
+
+/**
+ * ext2_find_shared - find the indirect blocks for partial truncation.
+ * @inode: inode in question
+ * @depth: depth of the affected branch
+ * @offsets: offsets of pointers in that branch (see ext2_block_to_path)
+ * @chain: place to store the pointers to partial indirect blocks
+ * @top: place to the (detached) top of branch
+ *
+ * This is a helper function used by ext2_truncate().
+ *
+ * When we do truncate() we may have to clean the ends of several indirect
+ * blocks but leave the blocks themselves alive. Block is partially
+ * truncated if some data below the new i_size is referred from it (and
+ * it is on the path to the first completely truncated data block, indeed).
+ * We have to free the top of that path along with everything to the right
+ * of the path. Since no allocation past the truncation point is possible
+ * until ext2_truncate() finishes, we may safely do the latter, but top
+ * of branch may require special attention - pageout below the truncation
+ * point might try to populate it.
+ *
+ * We atomically detach the top of branch from the tree, store the block
+ * number of its root in *@top, pointers to buffer_heads of partially
+ * truncated blocks - in @chain[].bh and pointers to their last elements
+ * that should not be removed - in @chain[].p. Return value is the pointer
+ * to last filled element of @chain.
+ *
+ * The work left to caller to do the actual freeing of subtrees:
+ * a) free the subtree starting from *@top
+ * b) free the subtrees whose roots are stored in
+ * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
+ * c) free the subtrees growing from the inode past the @chain[0].p
+ * (no partially truncated stuff there).
+ */
+
+static Indirect *ext2_find_shared(struct inode *inode,
+ int depth,
+ int offsets[4],
+ Indirect chain[4],
+ __le32 *top)
+{
+ Indirect *partial, *p;
+ int k, err;
+
+ *top = 0;
+ for (k = depth; k > 1 && !offsets[k-1]; k--)
+ ;
+ partial = ext2_get_branch(inode, k, offsets, chain, &err);
+ if (!partial)
+ partial = chain + k-1;
+ /*
+ * If the branch acquired continuation since we've looked at it -
+ * fine, it should all survive and (new) top doesn't belong to us.
+ */
+ write_lock(&EXT2_I(inode)->i_meta_lock);
+ if (!partial->key && *partial->p) {
+ write_unlock(&EXT2_I(inode)->i_meta_lock);
+ goto no_top;
+ }
+ for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
+ ;
+ /*
+ * OK, we've found the last block that must survive. The rest of our
+ * branch should be detached before unlocking. However, if that rest
+ * of branch is all ours and does not grow immediately from the inode
+ * it's easier to cheat and just decrement partial->p.
+ */
+ if (p == chain + k - 1 && p > chain) {
+ p->p--;
+ } else {
+ *top = *p->p;
+ *p->p = 0;
+ }
+ write_unlock(&EXT2_I(inode)->i_meta_lock);
+
+ while(partial > p)
+ {
+ brelse(partial->bh);
+ partial--;
+ }
+no_top:
+ return partial;
+}
+
+/**
+ * ext2_free_data - free a list of data blocks
+ * @inode: inode we are dealing with
+ * @p: array of block numbers
+ * @q: points immediately past the end of array
+ *
+ * We are freeing all blocks referred from that array (numbers are
+ * stored as little-endian 32-bit) and updating @inode->i_blocks
+ * appropriately.
+ */
+static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q)
+{
+ unsigned long block_to_free = 0, count = 0;
+ unsigned long nr;
+
+ for ( ; p < q ; p++) {
+ nr = le32_to_cpu(*p);
+ if (nr) {
+ *p = 0;
+ /* accumulate blocks to free if they're contiguous */
+ if (count == 0)
+ goto free_this;
+ else if (block_to_free == nr - count)
+ count++;
+ else {
+ ext2_free_blocks (inode, block_to_free, count);
+ mark_inode_dirty(inode);
+ free_this:
+ block_to_free = nr;
+ count = 1;
+ }
+ }
+ }
+ if (count > 0) {
+ ext2_free_blocks (inode, block_to_free, count);
+ mark_inode_dirty(inode);
+ }
+}
+
+/**
+ * ext2_free_branches - free an array of branches
+ * @inode: inode we are dealing with
+ * @p: array of block numbers
+ * @q: pointer immediately past the end of array
+ * @depth: depth of the branches to free
+ *
+ * We are freeing all blocks referred from these branches (numbers are
+ * stored as little-endian 32-bit) and updating @inode->i_blocks
+ * appropriately.
+ */
+static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth)
+{
+ struct buffer_head * bh;
+ unsigned long nr;
+
+ if (depth--) {
+ int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
+ for ( ; p < q ; p++) {
+ nr = le32_to_cpu(*p);
+ if (!nr)
+ continue;
+ *p = 0;
+ bh = sb_bread(inode->i_sb, nr);
+ /*
+ * A read failure? Report error and clear slot
+ * (should be rare).
+ */
+ if (!bh) {
+ ext2_error(inode->i_sb, "ext2_free_branches",
+ "Read failure, inode=%ld, block=%ld",
+ inode->i_ino, nr);
+ continue;
+ }
+ ext2_free_branches(inode,
+ (__le32*)bh->b_data,
+ (__le32*)bh->b_data + addr_per_block,
+ depth);
+ bforget(bh);
+ ext2_free_blocks(inode, nr, 1);
+ mark_inode_dirty(inode);
+ }
+ } else
+ ext2_free_data(inode, p, q);
+}
+
+/* dax_sem must be held when calling this function */
+static void __ext2_truncate_blocks(struct inode *inode, loff_t offset)
+{
+ __le32 *i_data = EXT2_I(inode)->i_data;
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
+ int offsets[4];
+ Indirect chain[4];
+ Indirect *partial;
+ __le32 nr = 0;
+ int n;
+ long iblock;
+ unsigned blocksize;
+ blocksize = inode->i_sb->s_blocksize;
+ iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
+
+#ifdef CONFIG_FS_DAX
+ WARN_ON(!rwsem_is_locked(&ei->dax_sem));
+#endif
+
+ n = ext2_block_to_path(inode, iblock, offsets, NULL);
+ if (n == 0)
+ return;
+
+ /*
+ * From here we block out all ext2_get_block() callers who want to
+ * modify the block allocation tree.
+ */
+ mutex_lock(&ei->truncate_mutex);
+
+ if (n == 1) {
+ ext2_free_data(inode, i_data+offsets[0],
+ i_data + EXT2_NDIR_BLOCKS);
+ goto do_indirects;
+ }
+
+ partial = ext2_find_shared(inode, n, offsets, chain, &nr);
+ /* Kill the top of shared branch (already detached) */
+ if (nr) {
+ if (partial == chain)
+ mark_inode_dirty(inode);
+ else
+ mark_buffer_dirty_inode(partial->bh, inode);
+ ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);
+ }
+ /* Clear the ends of indirect blocks on the shared branch */
+ while (partial > chain) {
+ ext2_free_branches(inode,
+ partial->p + 1,
+ (__le32*)partial->bh->b_data+addr_per_block,
+ (chain+n-1) - partial);
+ mark_buffer_dirty_inode(partial->bh, inode);
+ brelse (partial->bh);
+ partial--;
+ }
+do_indirects:
+ /* Kill the remaining (whole) subtrees */
+ switch (offsets[0]) {
+ default:
+ nr = i_data[EXT2_IND_BLOCK];
+ if (nr) {
+ i_data[EXT2_IND_BLOCK] = 0;
+ mark_inode_dirty(inode);
+ ext2_free_branches(inode, &nr, &nr+1, 1);
+ }
+ case EXT2_IND_BLOCK:
+ nr = i_data[EXT2_DIND_BLOCK];
+ if (nr) {
+ i_data[EXT2_DIND_BLOCK] = 0;
+ mark_inode_dirty(inode);
+ ext2_free_branches(inode, &nr, &nr+1, 2);
+ }
+ case EXT2_DIND_BLOCK:
+ nr = i_data[EXT2_TIND_BLOCK];
+ if (nr) {
+ i_data[EXT2_TIND_BLOCK] = 0;
+ mark_inode_dirty(inode);
+ ext2_free_branches(inode, &nr, &nr+1, 3);
+ }
+ case EXT2_TIND_BLOCK:
+ ;
+ }
+
+ ext2_discard_reservation(inode);
+
+ mutex_unlock(&ei->truncate_mutex);
+}
+
+static void ext2_truncate_blocks(struct inode *inode, loff_t offset)
+{
+ if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+ S_ISLNK(inode->i_mode)))
+ return;
+ if (ext2_inode_is_fast_symlink(inode))
+ return;
+
+ dax_sem_down_write(EXT2_I(inode));
+ __ext2_truncate_blocks(inode, offset);
+ dax_sem_up_write(EXT2_I(inode));
+}
+
+static int ext2_setsize(struct inode *inode, loff_t newsize)
+{
+ int error;
+
+ if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+ S_ISLNK(inode->i_mode)))
+ return -EINVAL;
+ if (ext2_inode_is_fast_symlink(inode))
+ return -EINVAL;
+ if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+ return -EPERM;
+
+ inode_dio_wait(inode);
+
+ if (IS_DAX(inode)) {
+ error = iomap_zero_range(inode, newsize,
+ PAGE_ALIGN(newsize) - newsize, NULL,
+ &ext2_iomap_ops);
+ } else if (test_opt(inode->i_sb, NOBH))
+ error = nobh_truncate_page(inode->i_mapping,
+ newsize, ext2_get_block);
+ else
+ error = block_truncate_page(inode->i_mapping,
+ newsize, ext2_get_block);
+ if (error)
+ return error;
+
+ dax_sem_down_write(EXT2_I(inode));
+ truncate_setsize(inode, newsize);
+ __ext2_truncate_blocks(inode, newsize);
+ dax_sem_up_write(EXT2_I(inode));
+
+ inode->i_mtime = inode->i_ctime = current_time(inode);
+ if (inode_needs_sync(inode)) {
+ sync_mapping_buffers(inode->i_mapping);
+ sync_inode_metadata(inode, 1);
+ } else {
+ mark_inode_dirty(inode);
+ }
+
+ return 0;
+}
+
+static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino,
+ struct buffer_head **p)
+{
+ struct buffer_head * bh;
+ unsigned long block_group;
+ unsigned long block;
+ unsigned long offset;
+ struct ext2_group_desc * gdp;
+
+ *p = NULL;
+ if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) ||
+ ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
+ goto Einval;
+
+ block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
+ gdp = ext2_get_group_desc(sb, block_group, NULL);
+ if (!gdp)
+ goto Egdp;
+ /*
+ * Figure out the offset within the block group inode table
+ */
+ offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb);
+ block = le32_to_cpu(gdp->bg_inode_table) +
+ (offset >> EXT2_BLOCK_SIZE_BITS(sb));
+ if (!(bh = sb_bread(sb, block)))
+ goto Eio;
+
+ *p = bh;
+ offset &= (EXT2_BLOCK_SIZE(sb) - 1);
+ return (struct ext2_inode *) (bh->b_data + offset);
+
+Einval:
+ ext2_error(sb, "ext2_get_inode", "bad inode number: %lu",
+ (unsigned long) ino);
+ return ERR_PTR(-EINVAL);
+Eio:
+ ext2_error(sb, "ext2_get_inode",
+ "unable to read inode block - inode=%lu, block=%lu",
+ (unsigned long) ino, block);
+Egdp:
+ return ERR_PTR(-EIO);
+}
+
+void ext2_set_inode_flags(struct inode *inode)
+{
+ unsigned int flags = EXT2_I(inode)->i_flags;
+
+ inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME |
+ S_DIRSYNC | S_DAX);
+ if (flags & EXT2_SYNC_FL)
+ inode->i_flags |= S_SYNC;
+ if (flags & EXT2_APPEND_FL)
+ inode->i_flags |= S_APPEND;
+ if (flags & EXT2_IMMUTABLE_FL)
+ inode->i_flags |= S_IMMUTABLE;
+ if (flags & EXT2_NOATIME_FL)
+ inode->i_flags |= S_NOATIME;
+ if (flags & EXT2_DIRSYNC_FL)
+ inode->i_flags |= S_DIRSYNC;
+ if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode))
+ inode->i_flags |= S_DAX;
+}
+
+void ext2_set_file_ops(struct inode *inode)
+{
+ inode->i_op = &ext2_file_inode_operations;
+ inode->i_fop = &ext2_file_operations;
+ if (IS_DAX(inode))
+ inode->i_mapping->a_ops = &ext2_dax_aops;
+ else if (test_opt(inode->i_sb, NOBH))
+ inode->i_mapping->a_ops = &ext2_nobh_aops;
+ else
+ inode->i_mapping->a_ops = &ext2_aops;
+}
+
+struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
+{
+ struct ext2_inode_info *ei;
+ struct buffer_head * bh;
+ struct ext2_inode *raw_inode;
+ struct inode *inode;
+ long ret = -EIO;
+ int n;
+ uid_t i_uid;
+ gid_t i_gid;
+
+ inode = iget_locked(sb, ino);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+ if (!(inode->i_state & I_NEW))
+ return inode;
+
+ ei = EXT2_I(inode);
+ ei->i_block_alloc_info = NULL;
+
+ raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
+ if (IS_ERR(raw_inode)) {
+ ret = PTR_ERR(raw_inode);
+ goto bad_inode;
+ }
+
+ inode->i_mode = le16_to_cpu(raw_inode->i_mode);
+ i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
+ i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
+ if (!(test_opt (inode->i_sb, NO_UID32))) {
+ i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
+ i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
+ }
+ i_uid_write(inode, i_uid);
+ i_gid_write(inode, i_gid);
+ set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
+ inode->i_size = le32_to_cpu(raw_inode->i_size);
+ inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
+ inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
+ inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
+ inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
+ ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
+ /* We now have enough fields to check if the inode was active or not.
+ * This is needed because nfsd might try to access dead inodes
+ * the test is that same one that e2fsck uses
+ * NeilBrown 1999oct15
+ */
+ if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) {
+ /* this inode is deleted */
+ brelse (bh);
+ ret = -ESTALE;
+ goto bad_inode;
+ }
+ inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
+ ei->i_flags = le32_to_cpu(raw_inode->i_flags);
+ ext2_set_inode_flags(inode);
+ ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
+ ei->i_frag_no = raw_inode->i_frag;
+ ei->i_frag_size = raw_inode->i_fsize;
+ ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
+ ei->i_dir_acl = 0;
+
+ if (ei->i_file_acl &&
+ !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) {
+ ext2_error(sb, "ext2_iget", "bad extended attribute block %u",
+ ei->i_file_acl);
+ brelse(bh);
+ ret = -EFSCORRUPTED;
+ goto bad_inode;
+ }
+
+ if (S_ISREG(inode->i_mode))
+ inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
+ else
+ ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
+ if (i_size_read(inode) < 0) {
+ ret = -EFSCORRUPTED;
+ goto bad_inode;
+ }
+ ei->i_dtime = 0;
+ inode->i_generation = le32_to_cpu(raw_inode->i_generation);
+ ei->i_state = 0;
+ ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
+ ei->i_dir_start_lookup = 0;
+
+ /*
+ * NOTE! The in-memory inode i_data array is in little-endian order
+ * even on big-endian machines: we do NOT byteswap the block numbers!
+ */
+ for (n = 0; n < EXT2_N_BLOCKS; n++)
+ ei->i_data[n] = raw_inode->i_block[n];
+
+ if (S_ISREG(inode->i_mode)) {
+ ext2_set_file_ops(inode);
+ } else if (S_ISDIR(inode->i_mode)) {
+ inode->i_op = &ext2_dir_inode_operations;
+ inode->i_fop = &ext2_dir_operations;
+ if (test_opt(inode->i_sb, NOBH))
+ inode->i_mapping->a_ops = &ext2_nobh_aops;
+ else
+ inode->i_mapping->a_ops = &ext2_aops;
+ } else if (S_ISLNK(inode->i_mode)) {
+ if (ext2_inode_is_fast_symlink(inode)) {
+ inode->i_link = (char *)ei->i_data;
+ inode->i_op = &ext2_fast_symlink_inode_operations;
+ nd_terminate_link(ei->i_data, inode->i_size,
+ sizeof(ei->i_data) - 1);
+ } else {
+ inode->i_op = &ext2_symlink_inode_operations;
+ inode_nohighmem(inode);
+ if (test_opt(inode->i_sb, NOBH))
+ inode->i_mapping->a_ops = &ext2_nobh_aops;
+ else
+ inode->i_mapping->a_ops = &ext2_aops;
+ }
+ } else {
+ inode->i_op = &ext2_special_inode_operations;
+ if (raw_inode->i_block[0])
+ init_special_inode(inode, inode->i_mode,
+ old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
+ else
+ init_special_inode(inode, inode->i_mode,
+ new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
+ }
+ brelse (bh);
+ unlock_new_inode(inode);
+ return inode;
+
+bad_inode:
+ iget_failed(inode);
+ return ERR_PTR(ret);
+}
+
+static int __ext2_write_inode(struct inode *inode, int do_sync)
+{
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ struct super_block *sb = inode->i_sb;
+ ino_t ino = inode->i_ino;
+ uid_t uid = i_uid_read(inode);
+ gid_t gid = i_gid_read(inode);
+ struct buffer_head * bh;
+ struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh);
+ int n;
+ int err = 0;
+
+ if (IS_ERR(raw_inode))
+ return -EIO;
+
+ /* For fields not not tracking in the in-memory inode,
+ * initialise them to zero for new inodes. */
+ if (ei->i_state & EXT2_STATE_NEW)
+ memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size);
+
+ raw_inode->i_mode = cpu_to_le16(inode->i_mode);
+ if (!(test_opt(sb, NO_UID32))) {
+ raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));
+ raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid));
+/*
+ * Fix up interoperability with old kernels. Otherwise, old inodes get
+ * re-used with the upper 16 bits of the uid/gid intact
+ */
+ if (!ei->i_dtime) {
+ raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid));
+ raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid));
+ } else {
+ raw_inode->i_uid_high = 0;
+ raw_inode->i_gid_high = 0;
+ }
+ } else {
+ raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid));
+ raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid));
+ raw_inode->i_uid_high = 0;
+ raw_inode->i_gid_high = 0;
+ }
+ raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
+ raw_inode->i_size = cpu_to_le32(inode->i_size);
+ raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
+ raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
+ raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
+
+ raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
+ raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
+ raw_inode->i_flags = cpu_to_le32(ei->i_flags);
+ raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
+ raw_inode->i_frag = ei->i_frag_no;
+ raw_inode->i_fsize = ei->i_frag_size;
+ raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
+ if (!S_ISREG(inode->i_mode))
+ raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
+ else {
+ raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32);
+ if (inode->i_size > 0x7fffffffULL) {
+ if (!EXT2_HAS_RO_COMPAT_FEATURE(sb,
+ EXT2_FEATURE_RO_COMPAT_LARGE_FILE) ||
+ EXT2_SB(sb)->s_es->s_rev_level ==
+ cpu_to_le32(EXT2_GOOD_OLD_REV)) {
+ /* If this is the first large file
+ * created, add a flag to the superblock.
+ */
+ spin_lock(&EXT2_SB(sb)->s_lock);
+ ext2_update_dynamic_rev(sb);
+ EXT2_SET_RO_COMPAT_FEATURE(sb,
+ EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
+ spin_unlock(&EXT2_SB(sb)->s_lock);
+ ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1);
+ }
+ }
+ }
+
+ raw_inode->i_generation = cpu_to_le32(inode->i_generation);
+ if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
+ if (old_valid_dev(inode->i_rdev)) {
+ raw_inode->i_block[0] =
+ cpu_to_le32(old_encode_dev(inode->i_rdev));
+ raw_inode->i_block[1] = 0;
+ } else {
+ raw_inode->i_block[0] = 0;
+ raw_inode->i_block[1] =
+ cpu_to_le32(new_encode_dev(inode->i_rdev));
+ raw_inode->i_block[2] = 0;
+ }
+ } else for (n = 0; n < EXT2_N_BLOCKS; n++)
+ raw_inode->i_block[n] = ei->i_data[n];
+ mark_buffer_dirty(bh);
+ if (do_sync) {
+ sync_dirty_buffer(bh);
+ if (buffer_req(bh) && !buffer_uptodate(bh)) {
+ printk ("IO error syncing ext2 inode [%s:%08lx]\n",
+ sb->s_id, (unsigned long) ino);
+ err = -EIO;
+ }
+ }
+ ei->i_state &= ~EXT2_STATE_NEW;
+ brelse (bh);
+ return err;
+}
+
+int ext2_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+ return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
+}
+
+int ext2_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+ struct inode *inode = d_inode(dentry);
+ int error;
+
+ error = setattr_prepare(dentry, iattr);
+ if (error)
+ return error;
+
+ if (is_quota_modification(inode, iattr)) {
+ error = dquot_initialize(inode);
+ if (error)
+ return error;
+ }
+ if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) ||
+ (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) {
+ error = dquot_transfer(inode, iattr);
+ if (error)
+ return error;
+ }
+ if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) {
+ error = ext2_setsize(inode, iattr->ia_size);
+ if (error)
+ return error;
+ }
+ setattr_copy(inode, iattr);
+ if (iattr->ia_valid & ATTR_MODE)
+ error = posix_acl_chmod(inode, inode->i_mode);
+ mark_inode_dirty(inode);
+
+ return error;
+}
diff --git a/fs/ext2/ioctl.c b/fs/ext2/ioctl.c
new file mode 100644
index 0000000..0367c00
--- /dev/null
+++ b/fs/ext2/ioctl.c
@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/ioctl.c
+ *
+ * Copyright (C) 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ */
+
+#include "ext2.h"
+#include <linux/capability.h>
+#include <linux/time.h>
+#include <linux/sched.h>
+#include <linux/compat.h>
+#include <linux/mount.h>
+#include <asm/current.h>
+#include <linux/uaccess.h>
+
+
+long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+ struct inode *inode = file_inode(filp);
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ unsigned int flags;
+ unsigned short rsv_window_size;
+ int ret;
+
+ ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
+
+ switch (cmd) {
+ case EXT2_IOC_GETFLAGS:
+ flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
+ return put_user(flags, (int __user *) arg);
+ case EXT2_IOC_SETFLAGS: {
+ unsigned int oldflags;
+
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
+ if (!inode_owner_or_capable(inode)) {
+ ret = -EACCES;
+ goto setflags_out;
+ }
+
+ if (get_user(flags, (int __user *) arg)) {
+ ret = -EFAULT;
+ goto setflags_out;
+ }
+
+ flags = ext2_mask_flags(inode->i_mode, flags);
+
+ inode_lock(inode);
+ /* Is it quota file? Do not allow user to mess with it */
+ if (IS_NOQUOTA(inode)) {
+ inode_unlock(inode);
+ ret = -EPERM;
+ goto setflags_out;
+ }
+ oldflags = ei->i_flags;
+
+ /*
+ * The IMMUTABLE and APPEND_ONLY flags can only be changed by
+ * the relevant capability.
+ *
+ * This test looks nicer. Thanks to Pauline Middelink
+ */
+ if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
+ if (!capable(CAP_LINUX_IMMUTABLE)) {
+ inode_unlock(inode);
+ ret = -EPERM;
+ goto setflags_out;
+ }
+ }
+
+ flags = flags & EXT2_FL_USER_MODIFIABLE;
+ flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
+ ei->i_flags = flags;
+
+ ext2_set_inode_flags(inode);
+ inode->i_ctime = current_time(inode);
+ inode_unlock(inode);
+
+ mark_inode_dirty(inode);
+setflags_out:
+ mnt_drop_write_file(filp);
+ return ret;
+ }
+ case EXT2_IOC_GETVERSION:
+ return put_user(inode->i_generation, (int __user *) arg);
+ case EXT2_IOC_SETVERSION: {
+ __u32 generation;
+
+ if (!inode_owner_or_capable(inode))
+ return -EPERM;
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+ if (get_user(generation, (int __user *) arg)) {
+ ret = -EFAULT;
+ goto setversion_out;
+ }
+
+ inode_lock(inode);
+ inode->i_ctime = current_time(inode);
+ inode->i_generation = generation;
+ inode_unlock(inode);
+
+ mark_inode_dirty(inode);
+setversion_out:
+ mnt_drop_write_file(filp);
+ return ret;
+ }
+ case EXT2_IOC_GETRSVSZ:
+ if (test_opt(inode->i_sb, RESERVATION)
+ && S_ISREG(inode->i_mode)
+ && ei->i_block_alloc_info) {
+ rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
+ return put_user(rsv_window_size, (int __user *)arg);
+ }
+ return -ENOTTY;
+ case EXT2_IOC_SETRSVSZ: {
+
+ if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
+ return -ENOTTY;
+
+ if (!inode_owner_or_capable(inode))
+ return -EACCES;
+
+ if (get_user(rsv_window_size, (int __user *)arg))
+ return -EFAULT;
+
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
+ if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
+ rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
+
+ /*
+ * need to allocate reservation structure for this inode
+ * before set the window size
+ */
+ /*
+ * XXX What lock should protect the rsv_goal_size?
+ * Accessed in ext2_get_block only. ext3 uses i_truncate.
+ */
+ mutex_lock(&ei->truncate_mutex);
+ if (!ei->i_block_alloc_info)
+ ext2_init_block_alloc_info(inode);
+
+ if (ei->i_block_alloc_info){
+ struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
+ rsv->rsv_goal_size = rsv_window_size;
+ }
+ mutex_unlock(&ei->truncate_mutex);
+ mnt_drop_write_file(filp);
+ return 0;
+ }
+ default:
+ return -ENOTTY;
+ }
+}
+
+#ifdef CONFIG_COMPAT
+long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ /* These are just misnamed, they actually get/put from/to user an int */
+ switch (cmd) {
+ case EXT2_IOC32_GETFLAGS:
+ cmd = EXT2_IOC_GETFLAGS;
+ break;
+ case EXT2_IOC32_SETFLAGS:
+ cmd = EXT2_IOC_SETFLAGS;
+ break;
+ case EXT2_IOC32_GETVERSION:
+ cmd = EXT2_IOC_GETVERSION;
+ break;
+ case EXT2_IOC32_SETVERSION:
+ cmd = EXT2_IOC_SETVERSION;
+ break;
+ default:
+ return -ENOIOCTLCMD;
+ }
+ return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
+}
+#endif
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
new file mode 100644
index 0000000..0c26dcc
--- /dev/null
+++ b/fs/ext2/namei.c
@@ -0,0 +1,432 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/namei.c
+ *
+ * Rewrite to pagecache. Almost all code had been changed, so blame me
+ * if the things go wrong. Please, send bug reports to
+ * viro@parcelfarce.linux.theplanet.co.uk
+ *
+ * Stuff here is basically a glue between the VFS and generic UNIXish
+ * filesystem that keeps everything in pagecache. All knowledge of the
+ * directory layout is in fs/ext2/dir.c - it turned out to be easily separatable
+ * and it's easier to debug that way. In principle we might want to
+ * generalize that a bit and turn it into a library. Or not.
+ *
+ * The only non-static object here is ext2_dir_inode_operations.
+ *
+ * TODO: get rid of kmap() use, add readahead.
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * from
+ *
+ * linux/fs/minix/namei.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * Big-endian to little-endian byte-swapping/bitmaps by
+ * David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include <linux/pagemap.h>
+#include <linux/quotaops.h>
+#include "ext2.h"
+#include "xattr.h"
+#include "acl.h"
+
+static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
+{
+ int err = ext2_add_link(dentry, inode);
+ if (!err) {
+ d_instantiate_new(dentry, inode);
+ return 0;
+ }
+ inode_dec_link_count(inode);
+ discard_new_inode(inode);
+ return err;
+}
+
+/*
+ * Methods themselves.
+ */
+
+static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
+{
+ struct inode * inode;
+ ino_t ino;
+
+ if (dentry->d_name.len > EXT2_NAME_LEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ ino = ext2_inode_by_name(dir, &dentry->d_name);
+ inode = NULL;
+ if (ino) {
+ inode = ext2_iget(dir->i_sb, ino);
+ if (inode == ERR_PTR(-ESTALE)) {
+ ext2_error(dir->i_sb, __func__,
+ "deleted inode referenced: %lu",
+ (unsigned long) ino);
+ return ERR_PTR(-EIO);
+ }
+ }
+ return d_splice_alias(inode, dentry);
+}
+
+struct dentry *ext2_get_parent(struct dentry *child)
+{
+ struct qstr dotdot = QSTR_INIT("..", 2);
+ unsigned long ino = ext2_inode_by_name(d_inode(child), &dotdot);
+ if (!ino)
+ return ERR_PTR(-ENOENT);
+ return d_obtain_alias(ext2_iget(child->d_sb, ino));
+}
+
+/*
+ * By the time this is called, we already have created
+ * the directory cache entry for the new file, but it
+ * is so far negative - it has no inode.
+ *
+ * If the create succeeds, we fill in the inode information
+ * with d_instantiate().
+ */
+static int ext2_create (struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
+{
+ struct inode *inode;
+ int err;
+
+ err = dquot_initialize(dir);
+ if (err)
+ return err;
+
+ inode = ext2_new_inode(dir, mode, &dentry->d_name);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ ext2_set_file_ops(inode);
+ mark_inode_dirty(inode);
+ return ext2_add_nondir(dentry, inode);
+}
+
+static int ext2_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+ struct inode *inode = ext2_new_inode(dir, mode, NULL);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ ext2_set_file_ops(inode);
+ mark_inode_dirty(inode);
+ d_tmpfile(dentry, inode);
+ unlock_new_inode(inode);
+ return 0;
+}
+
+static int ext2_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
+{
+ struct inode * inode;
+ int err;
+
+ err = dquot_initialize(dir);
+ if (err)
+ return err;
+
+ inode = ext2_new_inode (dir, mode, &dentry->d_name);
+ err = PTR_ERR(inode);
+ if (!IS_ERR(inode)) {
+ init_special_inode(inode, inode->i_mode, rdev);
+#ifdef CONFIG_EXT2_FS_XATTR
+ inode->i_op = &ext2_special_inode_operations;
+#endif
+ mark_inode_dirty(inode);
+ err = ext2_add_nondir(dentry, inode);
+ }
+ return err;
+}
+
+static int ext2_symlink (struct inode * dir, struct dentry * dentry,
+ const char * symname)
+{
+ struct super_block * sb = dir->i_sb;
+ int err = -ENAMETOOLONG;
+ unsigned l = strlen(symname)+1;
+ struct inode * inode;
+
+ if (l > sb->s_blocksize)
+ goto out;
+
+ err = dquot_initialize(dir);
+ if (err)
+ goto out;
+
+ inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out;
+
+ if (l > sizeof (EXT2_I(inode)->i_data)) {
+ /* slow symlink */
+ inode->i_op = &ext2_symlink_inode_operations;
+ inode_nohighmem(inode);
+ if (test_opt(inode->i_sb, NOBH))
+ inode->i_mapping->a_ops = &ext2_nobh_aops;
+ else
+ inode->i_mapping->a_ops = &ext2_aops;
+ err = page_symlink(inode, symname, l);
+ if (err)
+ goto out_fail;
+ } else {
+ /* fast symlink */
+ inode->i_op = &ext2_fast_symlink_inode_operations;
+ inode->i_link = (char*)EXT2_I(inode)->i_data;
+ memcpy(inode->i_link, symname, l);
+ inode->i_size = l-1;
+ }
+ mark_inode_dirty(inode);
+
+ err = ext2_add_nondir(dentry, inode);
+out:
+ return err;
+
+out_fail:
+ inode_dec_link_count(inode);
+ discard_new_inode(inode);
+ goto out;
+}
+
+static int ext2_link (struct dentry * old_dentry, struct inode * dir,
+ struct dentry *dentry)
+{
+ struct inode *inode = d_inode(old_dentry);
+ int err;
+
+ err = dquot_initialize(dir);
+ if (err)
+ return err;
+
+ inode->i_ctime = current_time(inode);
+ inode_inc_link_count(inode);
+ ihold(inode);
+
+ err = ext2_add_link(dentry, inode);
+ if (!err) {
+ d_instantiate(dentry, inode);
+ return 0;
+ }
+ inode_dec_link_count(inode);
+ iput(inode);
+ return err;
+}
+
+static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
+{
+ struct inode * inode;
+ int err;
+
+ err = dquot_initialize(dir);
+ if (err)
+ return err;
+
+ inode_inc_link_count(dir);
+
+ inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_dir;
+
+ inode->i_op = &ext2_dir_inode_operations;
+ inode->i_fop = &ext2_dir_operations;
+ if (test_opt(inode->i_sb, NOBH))
+ inode->i_mapping->a_ops = &ext2_nobh_aops;
+ else
+ inode->i_mapping->a_ops = &ext2_aops;
+
+ inode_inc_link_count(inode);
+
+ err = ext2_make_empty(inode, dir);
+ if (err)
+ goto out_fail;
+
+ err = ext2_add_link(dentry, inode);
+ if (err)
+ goto out_fail;
+
+ d_instantiate_new(dentry, inode);
+out:
+ return err;
+
+out_fail:
+ inode_dec_link_count(inode);
+ inode_dec_link_count(inode);
+ discard_new_inode(inode);
+out_dir:
+ inode_dec_link_count(dir);
+ goto out;
+}
+
+static int ext2_unlink(struct inode * dir, struct dentry *dentry)
+{
+ struct inode * inode = d_inode(dentry);
+ struct ext2_dir_entry_2 * de;
+ struct page * page;
+ int err;
+
+ err = dquot_initialize(dir);
+ if (err)
+ goto out;
+
+ de = ext2_find_entry (dir, &dentry->d_name, &page);
+ if (!de) {
+ err = -ENOENT;
+ goto out;
+ }
+
+ err = ext2_delete_entry (de, page);
+ if (err)
+ goto out;
+
+ inode->i_ctime = dir->i_ctime;
+ inode_dec_link_count(inode);
+ err = 0;
+out:
+ return err;
+}
+
+static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
+{
+ struct inode * inode = d_inode(dentry);
+ int err = -ENOTEMPTY;
+
+ if (ext2_empty_dir(inode)) {
+ err = ext2_unlink(dir, dentry);
+ if (!err) {
+ inode->i_size = 0;
+ inode_dec_link_count(inode);
+ inode_dec_link_count(dir);
+ }
+ }
+ return err;
+}
+
+static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
+ struct inode * new_dir, struct dentry * new_dentry,
+ unsigned int flags)
+{
+ struct inode * old_inode = d_inode(old_dentry);
+ struct inode * new_inode = d_inode(new_dentry);
+ struct page * dir_page = NULL;
+ struct ext2_dir_entry_2 * dir_de = NULL;
+ struct page * old_page;
+ struct ext2_dir_entry_2 * old_de;
+ int err;
+
+ if (flags & ~RENAME_NOREPLACE)
+ return -EINVAL;
+
+ err = dquot_initialize(old_dir);
+ if (err)
+ goto out;
+
+ err = dquot_initialize(new_dir);
+ if (err)
+ goto out;
+
+ old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
+ if (!old_de) {
+ err = -ENOENT;
+ goto out;
+ }
+
+ if (S_ISDIR(old_inode->i_mode)) {
+ err = -EIO;
+ dir_de = ext2_dotdot(old_inode, &dir_page);
+ if (!dir_de)
+ goto out_old;
+ }
+
+ if (new_inode) {
+ struct page *new_page;
+ struct ext2_dir_entry_2 *new_de;
+
+ err = -ENOTEMPTY;
+ if (dir_de && !ext2_empty_dir (new_inode))
+ goto out_dir;
+
+ err = -ENOENT;
+ new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
+ if (!new_de)
+ goto out_dir;
+ ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
+ new_inode->i_ctime = current_time(new_inode);
+ if (dir_de)
+ drop_nlink(new_inode);
+ inode_dec_link_count(new_inode);
+ } else {
+ err = ext2_add_link(new_dentry, old_inode);
+ if (err)
+ goto out_dir;
+ if (dir_de)
+ inode_inc_link_count(new_dir);
+ }
+
+ /*
+ * Like most other Unix systems, set the ctime for inodes on a
+ * rename.
+ */
+ old_inode->i_ctime = current_time(old_inode);
+ mark_inode_dirty(old_inode);
+
+ ext2_delete_entry (old_de, old_page);
+
+ if (dir_de) {
+ if (old_dir != new_dir)
+ ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
+ else {
+ kunmap(dir_page);
+ put_page(dir_page);
+ }
+ inode_dec_link_count(old_dir);
+ }
+ return 0;
+
+
+out_dir:
+ if (dir_de) {
+ kunmap(dir_page);
+ put_page(dir_page);
+ }
+out_old:
+ kunmap(old_page);
+ put_page(old_page);
+out:
+ return err;
+}
+
+const struct inode_operations ext2_dir_inode_operations = {
+ .create = ext2_create,
+ .lookup = ext2_lookup,
+ .link = ext2_link,
+ .unlink = ext2_unlink,
+ .symlink = ext2_symlink,
+ .mkdir = ext2_mkdir,
+ .rmdir = ext2_rmdir,
+ .mknod = ext2_mknod,
+ .rename = ext2_rename,
+#ifdef CONFIG_EXT2_FS_XATTR
+ .listxattr = ext2_listxattr,
+#endif
+ .setattr = ext2_setattr,
+ .get_acl = ext2_get_acl,
+ .set_acl = ext2_set_acl,
+ .tmpfile = ext2_tmpfile,
+};
+
+const struct inode_operations ext2_special_inode_operations = {
+#ifdef CONFIG_EXT2_FS_XATTR
+ .listxattr = ext2_listxattr,
+#endif
+ .setattr = ext2_setattr,
+ .get_acl = ext2_get_acl,
+ .set_acl = ext2_set_acl,
+};
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
new file mode 100644
index 0000000..0c38e31
--- /dev/null
+++ b/fs/ext2/super.c
@@ -0,0 +1,1669 @@
+/*
+ * linux/fs/ext2/super.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * from
+ *
+ * linux/fs/minix/inode.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * Big-endian to little-endian byte-swapping/bitmaps by
+ * David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/parser.h>
+#include <linux/random.h>
+#include <linux/buffer_head.h>
+#include <linux/exportfs.h>
+#include <linux/vfs.h>
+#include <linux/seq_file.h>
+#include <linux/mount.h>
+#include <linux/log2.h>
+#include <linux/quotaops.h>
+#include <linux/uaccess.h>
+#include <linux/dax.h>
+#include <linux/iversion.h>
+#include "ext2.h"
+#include "xattr.h"
+#include "acl.h"
+
+static void ext2_write_super(struct super_block *sb);
+static int ext2_remount (struct super_block * sb, int * flags, char * data);
+static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
+static int ext2_sync_fs(struct super_block *sb, int wait);
+static int ext2_freeze(struct super_block *sb);
+static int ext2_unfreeze(struct super_block *sb);
+
+void ext2_error(struct super_block *sb, const char *function,
+ const char *fmt, ...)
+{
+ struct va_format vaf;
+ va_list args;
+ struct ext2_sb_info *sbi = EXT2_SB(sb);
+ struct ext2_super_block *es = sbi->s_es;
+
+ if (!sb_rdonly(sb)) {
+ spin_lock(&sbi->s_lock);
+ sbi->s_mount_state |= EXT2_ERROR_FS;
+ es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
+ spin_unlock(&sbi->s_lock);
+ ext2_sync_super(sb, es, 1);
+ }
+
+ va_start(args, fmt);
+
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
+ sb->s_id, function, &vaf);
+
+ va_end(args);
+
+ if (test_opt(sb, ERRORS_PANIC))
+ panic("EXT2-fs: panic from previous error\n");
+ if (test_opt(sb, ERRORS_RO)) {
+ ext2_msg(sb, KERN_CRIT,
+ "error: remounting filesystem read-only");
+ sb->s_flags |= SB_RDONLY;
+ }
+}
+
+void ext2_msg(struct super_block *sb, const char *prefix,
+ const char *fmt, ...)
+{
+ struct va_format vaf;
+ va_list args;
+
+ va_start(args, fmt);
+
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
+
+ va_end(args);
+}
+
+/*
+ * This must be called with sbi->s_lock held.
+ */
+void ext2_update_dynamic_rev(struct super_block *sb)
+{
+ struct ext2_super_block *es = EXT2_SB(sb)->s_es;
+
+ if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
+ return;
+
+ ext2_msg(sb, KERN_WARNING,
+ "warning: updating to rev %d because of "
+ "new feature flag, running e2fsck is recommended",
+ EXT2_DYNAMIC_REV);
+
+ es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
+ es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
+ es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
+ /* leave es->s_feature_*compat flags alone */
+ /* es->s_uuid will be set by e2fsck if empty */
+
+ /*
+ * The rest of the superblock fields should be zero, and if not it
+ * means they are likely already in use, so leave them alone. We
+ * can leave it up to e2fsck to clean up any inconsistencies there.
+ */
+}
+
+#ifdef CONFIG_QUOTA
+static int ext2_quota_off(struct super_block *sb, int type);
+
+static void ext2_quota_off_umount(struct super_block *sb)
+{
+ int type;
+
+ for (type = 0; type < MAXQUOTAS; type++)
+ ext2_quota_off(sb, type);
+}
+#else
+static inline void ext2_quota_off_umount(struct super_block *sb)
+{
+}
+#endif
+
+static void ext2_put_super (struct super_block * sb)
+{
+ int db_count;
+ int i;
+ struct ext2_sb_info *sbi = EXT2_SB(sb);
+
+ ext2_quota_off_umount(sb);
+
+ if (sbi->s_ea_block_cache) {
+ ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
+ sbi->s_ea_block_cache = NULL;
+ }
+ if (!sb_rdonly(sb)) {
+ struct ext2_super_block *es = sbi->s_es;
+
+ spin_lock(&sbi->s_lock);
+ es->s_state = cpu_to_le16(sbi->s_mount_state);
+ spin_unlock(&sbi->s_lock);
+ ext2_sync_super(sb, es, 1);
+ }
+ db_count = sbi->s_gdb_count;
+ for (i = 0; i < db_count; i++)
+ if (sbi->s_group_desc[i])
+ brelse (sbi->s_group_desc[i]);
+ kfree(sbi->s_group_desc);
+ kfree(sbi->s_debts);
+ percpu_counter_destroy(&sbi->s_freeblocks_counter);
+ percpu_counter_destroy(&sbi->s_freeinodes_counter);
+ percpu_counter_destroy(&sbi->s_dirs_counter);
+ brelse (sbi->s_sbh);
+ sb->s_fs_info = NULL;
+ kfree(sbi->s_blockgroup_lock);
+ fs_put_dax(sbi->s_daxdev);
+ kfree(sbi);
+}
+
+static struct kmem_cache * ext2_inode_cachep;
+
+static struct inode *ext2_alloc_inode(struct super_block *sb)
+{
+ struct ext2_inode_info *ei;
+ ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
+ if (!ei)
+ return NULL;
+ ei->i_block_alloc_info = NULL;
+ inode_set_iversion(&ei->vfs_inode, 1);
+#ifdef CONFIG_QUOTA
+ memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
+#endif
+
+ return &ei->vfs_inode;
+}
+
+static void ext2_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
+}
+
+static void ext2_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, ext2_i_callback);
+}
+
+static void init_once(void *foo)
+{
+ struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
+
+ rwlock_init(&ei->i_meta_lock);
+#ifdef CONFIG_EXT2_FS_XATTR
+ init_rwsem(&ei->xattr_sem);
+#endif
+ mutex_init(&ei->truncate_mutex);
+#ifdef CONFIG_FS_DAX
+ init_rwsem(&ei->dax_sem);
+#endif
+ inode_init_once(&ei->vfs_inode);
+}
+
+static int __init init_inodecache(void)
+{
+ ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
+ sizeof(struct ext2_inode_info), 0,
+ (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
+ SLAB_ACCOUNT),
+ offsetof(struct ext2_inode_info, i_data),
+ sizeof_field(struct ext2_inode_info, i_data),
+ init_once);
+ if (ext2_inode_cachep == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
+static void destroy_inodecache(void)
+{
+ /*
+ * Make sure all delayed rcu free inodes are flushed before we
+ * destroy cache.
+ */
+ rcu_barrier();
+ kmem_cache_destroy(ext2_inode_cachep);
+}
+
+static int ext2_show_options(struct seq_file *seq, struct dentry *root)
+{
+ struct super_block *sb = root->d_sb;
+ struct ext2_sb_info *sbi = EXT2_SB(sb);
+ struct ext2_super_block *es = sbi->s_es;
+ unsigned long def_mount_opts;
+
+ spin_lock(&sbi->s_lock);
+ def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
+
+ if (sbi->s_sb_block != 1)
+ seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
+ if (test_opt(sb, MINIX_DF))
+ seq_puts(seq, ",minixdf");
+ if (test_opt(sb, GRPID))
+ seq_puts(seq, ",grpid");
+ if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
+ seq_puts(seq, ",nogrpid");
+ if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
+ le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
+ seq_printf(seq, ",resuid=%u",
+ from_kuid_munged(&init_user_ns, sbi->s_resuid));
+ }
+ if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
+ le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
+ seq_printf(seq, ",resgid=%u",
+ from_kgid_munged(&init_user_ns, sbi->s_resgid));
+ }
+ if (test_opt(sb, ERRORS_RO)) {
+ int def_errors = le16_to_cpu(es->s_errors);
+
+ if (def_errors == EXT2_ERRORS_PANIC ||
+ def_errors == EXT2_ERRORS_CONTINUE) {
+ seq_puts(seq, ",errors=remount-ro");
+ }
+ }
+ if (test_opt(sb, ERRORS_CONT))
+ seq_puts(seq, ",errors=continue");
+ if (test_opt(sb, ERRORS_PANIC))
+ seq_puts(seq, ",errors=panic");
+ if (test_opt(sb, NO_UID32))
+ seq_puts(seq, ",nouid32");
+ if (test_opt(sb, DEBUG))
+ seq_puts(seq, ",debug");
+ if (test_opt(sb, OLDALLOC))
+ seq_puts(seq, ",oldalloc");
+
+#ifdef CONFIG_EXT2_FS_XATTR
+ if (test_opt(sb, XATTR_USER))
+ seq_puts(seq, ",user_xattr");
+ if (!test_opt(sb, XATTR_USER) &&
+ (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
+ seq_puts(seq, ",nouser_xattr");
+ }
+#endif
+
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+ if (test_opt(sb, POSIX_ACL))
+ seq_puts(seq, ",acl");
+ if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
+ seq_puts(seq, ",noacl");
+#endif
+
+ if (test_opt(sb, NOBH))
+ seq_puts(seq, ",nobh");
+
+#if defined(CONFIG_QUOTA)
+ if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
+ seq_puts(seq, ",usrquota");
+
+ if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
+ seq_puts(seq, ",grpquota");
+#endif
+
+#ifdef CONFIG_FS_DAX
+ if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
+ seq_puts(seq, ",xip");
+ if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
+ seq_puts(seq, ",dax");
+#endif
+
+ if (!test_opt(sb, RESERVATION))
+ seq_puts(seq, ",noreservation");
+
+ spin_unlock(&sbi->s_lock);
+ return 0;
+}
+
+#ifdef CONFIG_QUOTA
+static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
+static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
+static int ext2_quota_on(struct super_block *sb, int type, int format_id,
+ const struct path *path);
+static struct dquot **ext2_get_dquots(struct inode *inode)
+{
+ return EXT2_I(inode)->i_dquot;
+}
+
+static const struct quotactl_ops ext2_quotactl_ops = {
+ .quota_on = ext2_quota_on,
+ .quota_off = ext2_quota_off,
+ .quota_sync = dquot_quota_sync,
+ .get_state = dquot_get_state,
+ .set_info = dquot_set_dqinfo,
+ .get_dqblk = dquot_get_dqblk,
+ .set_dqblk = dquot_set_dqblk,
+ .get_nextdqblk = dquot_get_next_dqblk,
+};
+#endif
+
+static const struct super_operations ext2_sops = {
+ .alloc_inode = ext2_alloc_inode,
+ .destroy_inode = ext2_destroy_inode,
+ .write_inode = ext2_write_inode,
+ .evict_inode = ext2_evict_inode,
+ .put_super = ext2_put_super,
+ .sync_fs = ext2_sync_fs,
+ .freeze_fs = ext2_freeze,
+ .unfreeze_fs = ext2_unfreeze,
+ .statfs = ext2_statfs,
+ .remount_fs = ext2_remount,
+ .show_options = ext2_show_options,
+#ifdef CONFIG_QUOTA
+ .quota_read = ext2_quota_read,
+ .quota_write = ext2_quota_write,
+ .get_dquots = ext2_get_dquots,
+#endif
+};
+
+static struct inode *ext2_nfs_get_inode(struct super_block *sb,
+ u64 ino, u32 generation)
+{
+ struct inode *inode;
+
+ if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
+ return ERR_PTR(-ESTALE);
+ if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
+ return ERR_PTR(-ESTALE);
+
+ /*
+ * ext2_iget isn't quite right if the inode is currently unallocated!
+ * However ext2_iget currently does appropriate checks to handle stale
+ * inodes so everything is OK.
+ */
+ inode = ext2_iget(sb, ino);
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+ if (generation && inode->i_generation != generation) {
+ /* we didn't find the right inode.. */
+ iput(inode);
+ return ERR_PTR(-ESTALE);
+ }
+ return inode;
+}
+
+static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
+ int fh_len, int fh_type)
+{
+ return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+ ext2_nfs_get_inode);
+}
+
+static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
+ int fh_len, int fh_type)
+{
+ return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+ ext2_nfs_get_inode);
+}
+
+static const struct export_operations ext2_export_ops = {
+ .fh_to_dentry = ext2_fh_to_dentry,
+ .fh_to_parent = ext2_fh_to_parent,
+ .get_parent = ext2_get_parent,
+};
+
+static unsigned long get_sb_block(void **data)
+{
+ unsigned long sb_block;
+ char *options = (char *) *data;
+
+ if (!options || strncmp(options, "sb=", 3) != 0)
+ return 1; /* Default location */
+ options += 3;
+ sb_block = simple_strtoul(options, &options, 0);
+ if (*options && *options != ',') {
+ printk("EXT2-fs: Invalid sb specification: %s\n",
+ (char *) *data);
+ return 1;
+ }
+ if (*options == ',')
+ options++;
+ *data = (void *) options;
+ return sb_block;
+}
+
+enum {
+ Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
+ Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
+ Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
+ Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
+ Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
+ Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
+};
+
+static const match_table_t tokens = {
+ {Opt_bsd_df, "bsddf"},
+ {Opt_minix_df, "minixdf"},
+ {Opt_grpid, "grpid"},
+ {Opt_grpid, "bsdgroups"},
+ {Opt_nogrpid, "nogrpid"},
+ {Opt_nogrpid, "sysvgroups"},
+ {Opt_resgid, "resgid=%u"},
+ {Opt_resuid, "resuid=%u"},
+ {Opt_sb, "sb=%u"},
+ {Opt_err_cont, "errors=continue"},
+ {Opt_err_panic, "errors=panic"},
+ {Opt_err_ro, "errors=remount-ro"},
+ {Opt_nouid32, "nouid32"},
+ {Opt_nocheck, "check=none"},
+ {Opt_nocheck, "nocheck"},
+ {Opt_debug, "debug"},
+ {Opt_oldalloc, "oldalloc"},
+ {Opt_orlov, "orlov"},
+ {Opt_nobh, "nobh"},
+ {Opt_user_xattr, "user_xattr"},
+ {Opt_nouser_xattr, "nouser_xattr"},
+ {Opt_acl, "acl"},
+ {Opt_noacl, "noacl"},
+ {Opt_xip, "xip"},
+ {Opt_dax, "dax"},
+ {Opt_grpquota, "grpquota"},
+ {Opt_ignore, "noquota"},
+ {Opt_quota, "quota"},
+ {Opt_usrquota, "usrquota"},
+ {Opt_reservation, "reservation"},
+ {Opt_noreservation, "noreservation"},
+ {Opt_err, NULL}
+};
+
+static int parse_options(char *options, struct super_block *sb,
+ struct ext2_mount_options *opts)
+{
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+ int option;
+ kuid_t uid;
+ kgid_t gid;
+
+ if (!options)
+ return 1;
+
+ while ((p = strsep (&options, ",")) != NULL) {
+ int token;
+ if (!*p)
+ continue;
+
+ token = match_token(p, tokens, args);
+ switch (token) {
+ case Opt_bsd_df:
+ clear_opt (opts->s_mount_opt, MINIX_DF);
+ break;
+ case Opt_minix_df:
+ set_opt (opts->s_mount_opt, MINIX_DF);
+ break;
+ case Opt_grpid:
+ set_opt (opts->s_mount_opt, GRPID);
+ break;
+ case Opt_nogrpid:
+ clear_opt (opts->s_mount_opt, GRPID);
+ break;
+ case Opt_resuid:
+ if (match_int(&args[0], &option))
+ return 0;
+ uid = make_kuid(current_user_ns(), option);
+ if (!uid_valid(uid)) {
+ ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
+ return 0;
+
+ }
+ opts->s_resuid = uid;
+ break;
+ case Opt_resgid:
+ if (match_int(&args[0], &option))
+ return 0;
+ gid = make_kgid(current_user_ns(), option);
+ if (!gid_valid(gid)) {
+ ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
+ return 0;
+ }
+ opts->s_resgid = gid;
+ break;
+ case Opt_sb:
+ /* handled by get_sb_block() instead of here */
+ /* *sb_block = match_int(&args[0]); */
+ break;
+ case Opt_err_panic:
+ clear_opt (opts->s_mount_opt, ERRORS_CONT);
+ clear_opt (opts->s_mount_opt, ERRORS_RO);
+ set_opt (opts->s_mount_opt, ERRORS_PANIC);
+ break;
+ case Opt_err_ro:
+ clear_opt (opts->s_mount_opt, ERRORS_CONT);
+ clear_opt (opts->s_mount_opt, ERRORS_PANIC);
+ set_opt (opts->s_mount_opt, ERRORS_RO);
+ break;
+ case Opt_err_cont:
+ clear_opt (opts->s_mount_opt, ERRORS_RO);
+ clear_opt (opts->s_mount_opt, ERRORS_PANIC);
+ set_opt (opts->s_mount_opt, ERRORS_CONT);
+ break;
+ case Opt_nouid32:
+ set_opt (opts->s_mount_opt, NO_UID32);
+ break;
+ case Opt_nocheck:
+ ext2_msg(sb, KERN_WARNING,
+ "Option nocheck/check=none is deprecated and"
+ " will be removed in June 2020.");
+ clear_opt (opts->s_mount_opt, CHECK);
+ break;
+ case Opt_debug:
+ set_opt (opts->s_mount_opt, DEBUG);
+ break;
+ case Opt_oldalloc:
+ set_opt (opts->s_mount_opt, OLDALLOC);
+ break;
+ case Opt_orlov:
+ clear_opt (opts->s_mount_opt, OLDALLOC);
+ break;
+ case Opt_nobh:
+ set_opt (opts->s_mount_opt, NOBH);
+ break;
+#ifdef CONFIG_EXT2_FS_XATTR
+ case Opt_user_xattr:
+ set_opt (opts->s_mount_opt, XATTR_USER);
+ break;
+ case Opt_nouser_xattr:
+ clear_opt (opts->s_mount_opt, XATTR_USER);
+ break;
+#else
+ case Opt_user_xattr:
+ case Opt_nouser_xattr:
+ ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
+ "not supported");
+ break;
+#endif
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+ case Opt_acl:
+ set_opt(opts->s_mount_opt, POSIX_ACL);
+ break;
+ case Opt_noacl:
+ clear_opt(opts->s_mount_opt, POSIX_ACL);
+ break;
+#else
+ case Opt_acl:
+ case Opt_noacl:
+ ext2_msg(sb, KERN_INFO,
+ "(no)acl options not supported");
+ break;
+#endif
+ case Opt_xip:
+ ext2_msg(sb, KERN_INFO, "use dax instead of xip");
+ set_opt(opts->s_mount_opt, XIP);
+ /* Fall through */
+ case Opt_dax:
+#ifdef CONFIG_FS_DAX
+ ext2_msg(sb, KERN_WARNING,
+ "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
+ set_opt(opts->s_mount_opt, DAX);
+#else
+ ext2_msg(sb, KERN_INFO, "dax option not supported");
+#endif
+ break;
+
+#if defined(CONFIG_QUOTA)
+ case Opt_quota:
+ case Opt_usrquota:
+ set_opt(opts->s_mount_opt, USRQUOTA);
+ break;
+
+ case Opt_grpquota:
+ set_opt(opts->s_mount_opt, GRPQUOTA);
+ break;
+#else
+ case Opt_quota:
+ case Opt_usrquota:
+ case Opt_grpquota:
+ ext2_msg(sb, KERN_INFO,
+ "quota operations not supported");
+ break;
+#endif
+
+ case Opt_reservation:
+ set_opt(opts->s_mount_opt, RESERVATION);
+ ext2_msg(sb, KERN_INFO, "reservations ON");
+ break;
+ case Opt_noreservation:
+ clear_opt(opts->s_mount_opt, RESERVATION);
+ ext2_msg(sb, KERN_INFO, "reservations OFF");
+ break;
+ case Opt_ignore:
+ break;
+ default:
+ return 0;
+ }
+ }
+ return 1;
+}
+
+static int ext2_setup_super (struct super_block * sb,
+ struct ext2_super_block * es,
+ int read_only)
+{
+ int res = 0;
+ struct ext2_sb_info *sbi = EXT2_SB(sb);
+
+ if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
+ ext2_msg(sb, KERN_ERR,
+ "error: revision level too high, "
+ "forcing read-only mode");
+ res = SB_RDONLY;
+ }
+ if (read_only)
+ return res;
+ if (!(sbi->s_mount_state & EXT2_VALID_FS))
+ ext2_msg(sb, KERN_WARNING,
+ "warning: mounting unchecked fs, "
+ "running e2fsck is recommended");
+ else if ((sbi->s_mount_state & EXT2_ERROR_FS))
+ ext2_msg(sb, KERN_WARNING,
+ "warning: mounting fs with errors, "
+ "running e2fsck is recommended");
+ else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
+ le16_to_cpu(es->s_mnt_count) >=
+ (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
+ ext2_msg(sb, KERN_WARNING,
+ "warning: maximal mount count reached, "
+ "running e2fsck is recommended");
+ else if (le32_to_cpu(es->s_checkinterval) &&
+ (le32_to_cpu(es->s_lastcheck) +
+ le32_to_cpu(es->s_checkinterval) <=
+ ktime_get_real_seconds()))
+ ext2_msg(sb, KERN_WARNING,
+ "warning: checktime reached, "
+ "running e2fsck is recommended");
+ if (!le16_to_cpu(es->s_max_mnt_count))
+ es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
+ le16_add_cpu(&es->s_mnt_count, 1);
+ if (test_opt (sb, DEBUG))
+ ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
+ "bpg=%lu, ipg=%lu, mo=%04lx]",
+ EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
+ sbi->s_frag_size,
+ sbi->s_groups_count,
+ EXT2_BLOCKS_PER_GROUP(sb),
+ EXT2_INODES_PER_GROUP(sb),
+ sbi->s_mount_opt);
+ return res;
+}
+
+static int ext2_check_descriptors(struct super_block *sb)
+{
+ int i;
+ struct ext2_sb_info *sbi = EXT2_SB(sb);
+
+ ext2_debug ("Checking group descriptors");
+
+ for (i = 0; i < sbi->s_groups_count; i++) {
+ struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
+ ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
+ ext2_fsblk_t last_block;
+
+ if (i == sbi->s_groups_count - 1)
+ last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
+ else
+ last_block = first_block +
+ (EXT2_BLOCKS_PER_GROUP(sb) - 1);
+
+ if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
+ le32_to_cpu(gdp->bg_block_bitmap) > last_block)
+ {
+ ext2_error (sb, "ext2_check_descriptors",
+ "Block bitmap for group %d"
+ " not in group (block %lu)!",
+ i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
+ return 0;
+ }
+ if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
+ le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
+ {
+ ext2_error (sb, "ext2_check_descriptors",
+ "Inode bitmap for group %d"
+ " not in group (block %lu)!",
+ i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
+ return 0;
+ }
+ if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
+ le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
+ last_block)
+ {
+ ext2_error (sb, "ext2_check_descriptors",
+ "Inode table for group %d"
+ " not in group (block %lu)!",
+ i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
+ return 0;
+ }
+ }
+ return 1;
+}
+
+/*
+ * Maximal file size. There is a direct, and {,double-,triple-}indirect
+ * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
+ * We need to be 1 filesystem block less than the 2^32 sector limit.
+ */
+static loff_t ext2_max_size(int bits)
+{
+ loff_t res = EXT2_NDIR_BLOCKS;
+ int meta_blocks;
+ loff_t upper_limit;
+
+ /* This is calculated to be the largest file size for a
+ * dense, file such that the total number of
+ * sectors in the file, including data and all indirect blocks,
+ * does not exceed 2^32 -1
+ * __u32 i_blocks representing the total number of
+ * 512 bytes blocks of the file
+ */
+ upper_limit = (1LL << 32) - 1;
+
+ /* total blocks in file system block size */
+ upper_limit >>= (bits - 9);
+
+
+ /* indirect blocks */
+ meta_blocks = 1;
+ /* double indirect blocks */
+ meta_blocks += 1 + (1LL << (bits-2));
+ /* tripple indirect blocks */
+ meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
+
+ upper_limit -= meta_blocks;
+ upper_limit <<= bits;
+
+ res += 1LL << (bits-2);
+ res += 1LL << (2*(bits-2));
+ res += 1LL << (3*(bits-2));
+ res <<= bits;
+ if (res > upper_limit)
+ res = upper_limit;
+
+ if (res > MAX_LFS_FILESIZE)
+ res = MAX_LFS_FILESIZE;
+
+ return res;
+}
+
+static unsigned long descriptor_loc(struct super_block *sb,
+ unsigned long logic_sb_block,
+ int nr)
+{
+ struct ext2_sb_info *sbi = EXT2_SB(sb);
+ unsigned long bg, first_meta_bg;
+ int has_super = 0;
+
+ first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
+
+ if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
+ nr < first_meta_bg)
+ return (logic_sb_block + nr + 1);
+ bg = sbi->s_desc_per_block * nr;
+ if (ext2_bg_has_super(sb, bg))
+ has_super = 1;
+
+ return ext2_group_first_block_no(sb, bg) + has_super;
+}
+
+static int ext2_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
+ struct buffer_head * bh;
+ struct ext2_sb_info * sbi;
+ struct ext2_super_block * es;
+ struct inode *root;
+ unsigned long block;
+ unsigned long sb_block = get_sb_block(&data);
+ unsigned long logic_sb_block;
+ unsigned long offset = 0;
+ unsigned long def_mount_opts;
+ long ret = -ENOMEM;
+ int blocksize = BLOCK_SIZE;
+ int db_count;
+ int i, j;
+ __le32 features;
+ int err;
+ struct ext2_mount_options opts;
+
+ sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+ if (!sbi)
+ goto failed;
+
+ sbi->s_blockgroup_lock =
+ kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
+ if (!sbi->s_blockgroup_lock) {
+ kfree(sbi);
+ goto failed;
+ }
+ sb->s_fs_info = sbi;
+ sbi->s_sb_block = sb_block;
+ sbi->s_daxdev = dax_dev;
+
+ spin_lock_init(&sbi->s_lock);
+ ret = -EINVAL;
+
+ /*
+ * See what the current blocksize for the device is, and
+ * use that as the blocksize. Otherwise (or if the blocksize
+ * is smaller than the default) use the default.
+ * This is important for devices that have a hardware
+ * sectorsize that is larger than the default.
+ */
+ blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
+ if (!blocksize) {
+ ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
+ goto failed_sbi;
+ }
+
+ /*
+ * If the superblock doesn't start on a hardware sector boundary,
+ * calculate the offset.
+ */
+ if (blocksize != BLOCK_SIZE) {
+ logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
+ offset = (sb_block*BLOCK_SIZE) % blocksize;
+ } else {
+ logic_sb_block = sb_block;
+ }
+
+ if (!(bh = sb_bread(sb, logic_sb_block))) {
+ ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
+ goto failed_sbi;
+ }
+ /*
+ * Note: s_es must be initialized as soon as possible because
+ * some ext2 macro-instructions depend on its value
+ */
+ es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
+ sbi->s_es = es;
+ sb->s_magic = le16_to_cpu(es->s_magic);
+
+ if (sb->s_magic != EXT2_SUPER_MAGIC)
+ goto cantfind_ext2;
+
+ opts.s_mount_opt = 0;
+ /* Set defaults before we parse the mount options */
+ def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
+ if (def_mount_opts & EXT2_DEFM_DEBUG)
+ set_opt(opts.s_mount_opt, DEBUG);
+ if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
+ set_opt(opts.s_mount_opt, GRPID);
+ if (def_mount_opts & EXT2_DEFM_UID16)
+ set_opt(opts.s_mount_opt, NO_UID32);
+#ifdef CONFIG_EXT2_FS_XATTR
+ if (def_mount_opts & EXT2_DEFM_XATTR_USER)
+ set_opt(opts.s_mount_opt, XATTR_USER);
+#endif
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+ if (def_mount_opts & EXT2_DEFM_ACL)
+ set_opt(opts.s_mount_opt, POSIX_ACL);
+#endif
+
+ if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
+ set_opt(opts.s_mount_opt, ERRORS_PANIC);
+ else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
+ set_opt(opts.s_mount_opt, ERRORS_CONT);
+ else
+ set_opt(opts.s_mount_opt, ERRORS_RO);
+
+ opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
+ opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
+
+ set_opt(opts.s_mount_opt, RESERVATION);
+
+ if (!parse_options((char *) data, sb, &opts))
+ goto failed_mount;
+
+ sbi->s_mount_opt = opts.s_mount_opt;
+ sbi->s_resuid = opts.s_resuid;
+ sbi->s_resgid = opts.s_resgid;
+
+ sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
+ ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
+ SB_POSIXACL : 0);
+ sb->s_iflags |= SB_I_CGROUPWB;
+
+ if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
+ (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
+ EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
+ EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
+ ext2_msg(sb, KERN_WARNING,
+ "warning: feature flags set on rev 0 fs, "
+ "running e2fsck is recommended");
+ /*
+ * Check feature flags regardless of the revision level, since we
+ * previously didn't change the revision level when setting the flags,
+ * so there is a chance incompat flags are set on a rev 0 filesystem.
+ */
+ features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
+ if (features) {
+ ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
+ "unsupported optional features (%x)",
+ le32_to_cpu(features));
+ goto failed_mount;
+ }
+ if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
+ ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
+ "unsupported optional features (%x)",
+ le32_to_cpu(features));
+ goto failed_mount;
+ }
+
+ blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
+
+ if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
+ if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
+ ext2_msg(sb, KERN_ERR,
+ "DAX unsupported by block device. Turning off DAX.");
+ sbi->s_mount_opt &= ~EXT2_MOUNT_DAX;
+ }
+ }
+
+ /* If the blocksize doesn't match, re-read the thing.. */
+ if (sb->s_blocksize != blocksize) {
+ brelse(bh);
+
+ if (!sb_set_blocksize(sb, blocksize)) {
+ ext2_msg(sb, KERN_ERR,
+ "error: bad blocksize %d", blocksize);
+ goto failed_sbi;
+ }
+
+ logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
+ offset = (sb_block*BLOCK_SIZE) % blocksize;
+ bh = sb_bread(sb, logic_sb_block);
+ if(!bh) {
+ ext2_msg(sb, KERN_ERR, "error: couldn't read"
+ "superblock on 2nd try");
+ goto failed_sbi;
+ }
+ es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
+ sbi->s_es = es;
+ if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
+ ext2_msg(sb, KERN_ERR, "error: magic mismatch");
+ goto failed_mount;
+ }
+ }
+
+ sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
+ sb->s_max_links = EXT2_LINK_MAX;
+
+ if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
+ sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
+ sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
+ } else {
+ sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
+ sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
+ if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
+ !is_power_of_2(sbi->s_inode_size) ||
+ (sbi->s_inode_size > blocksize)) {
+ ext2_msg(sb, KERN_ERR,
+ "error: unsupported inode size: %d",
+ sbi->s_inode_size);
+ goto failed_mount;
+ }
+ }
+
+ sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
+ le32_to_cpu(es->s_log_frag_size);
+ if (sbi->s_frag_size == 0)
+ goto cantfind_ext2;
+ sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
+
+ sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
+ sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
+ sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
+
+ if (EXT2_INODE_SIZE(sb) == 0)
+ goto cantfind_ext2;
+ sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
+ if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
+ goto cantfind_ext2;
+ sbi->s_itb_per_group = sbi->s_inodes_per_group /
+ sbi->s_inodes_per_block;
+ sbi->s_desc_per_block = sb->s_blocksize /
+ sizeof (struct ext2_group_desc);
+ sbi->s_sbh = bh;
+ sbi->s_mount_state = le16_to_cpu(es->s_state);
+ sbi->s_addr_per_block_bits =
+ ilog2 (EXT2_ADDR_PER_BLOCK(sb));
+ sbi->s_desc_per_block_bits =
+ ilog2 (EXT2_DESC_PER_BLOCK(sb));
+
+ if (sb->s_magic != EXT2_SUPER_MAGIC)
+ goto cantfind_ext2;
+
+ if (sb->s_blocksize != bh->b_size) {
+ if (!silent)
+ ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
+ goto failed_mount;
+ }
+
+ if (sb->s_blocksize != sbi->s_frag_size) {
+ ext2_msg(sb, KERN_ERR,
+ "error: fragsize %lu != blocksize %lu"
+ "(not supported yet)",
+ sbi->s_frag_size, sb->s_blocksize);
+ goto failed_mount;
+ }
+
+ if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
+ ext2_msg(sb, KERN_ERR,
+ "error: #blocks per group too big: %lu",
+ sbi->s_blocks_per_group);
+ goto failed_mount;
+ }
+ if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
+ ext2_msg(sb, KERN_ERR,
+ "error: #fragments per group too big: %lu",
+ sbi->s_frags_per_group);
+ goto failed_mount;
+ }
+ if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
+ ext2_msg(sb, KERN_ERR,
+ "error: #inodes per group too big: %lu",
+ sbi->s_inodes_per_group);
+ goto failed_mount;
+ }
+
+ if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
+ goto cantfind_ext2;
+ sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
+ le32_to_cpu(es->s_first_data_block) - 1)
+ / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
+ db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
+ EXT2_DESC_PER_BLOCK(sb);
+ sbi->s_group_desc = kmalloc_array (db_count,
+ sizeof(struct buffer_head *),
+ GFP_KERNEL);
+ if (sbi->s_group_desc == NULL) {
+ ext2_msg(sb, KERN_ERR, "error: not enough memory");
+ goto failed_mount;
+ }
+ bgl_lock_init(sbi->s_blockgroup_lock);
+ sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
+ if (!sbi->s_debts) {
+ ext2_msg(sb, KERN_ERR, "error: not enough memory");
+ goto failed_mount_group_desc;
+ }
+ for (i = 0; i < db_count; i++) {
+ block = descriptor_loc(sb, logic_sb_block, i);
+ sbi->s_group_desc[i] = sb_bread(sb, block);
+ if (!sbi->s_group_desc[i]) {
+ for (j = 0; j < i; j++)
+ brelse (sbi->s_group_desc[j]);
+ ext2_msg(sb, KERN_ERR,
+ "error: unable to read group descriptors");
+ goto failed_mount_group_desc;
+ }
+ }
+ if (!ext2_check_descriptors (sb)) {
+ ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
+ goto failed_mount2;
+ }
+ sbi->s_gdb_count = db_count;
+ get_random_bytes(&sbi->s_next_generation, sizeof(u32));
+ spin_lock_init(&sbi->s_next_gen_lock);
+
+ /* per fileystem reservation list head & lock */
+ spin_lock_init(&sbi->s_rsv_window_lock);
+ sbi->s_rsv_window_root = RB_ROOT;
+ /*
+ * Add a single, static dummy reservation to the start of the
+ * reservation window list --- it gives us a placeholder for
+ * append-at-start-of-list which makes the allocation logic
+ * _much_ simpler.
+ */
+ sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
+ sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
+ sbi->s_rsv_window_head.rsv_alloc_hit = 0;
+ sbi->s_rsv_window_head.rsv_goal_size = 0;
+ ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
+
+ err = percpu_counter_init(&sbi->s_freeblocks_counter,
+ ext2_count_free_blocks(sb), GFP_KERNEL);
+ if (!err) {
+ err = percpu_counter_init(&sbi->s_freeinodes_counter,
+ ext2_count_free_inodes(sb), GFP_KERNEL);
+ }
+ if (!err) {
+ err = percpu_counter_init(&sbi->s_dirs_counter,
+ ext2_count_dirs(sb), GFP_KERNEL);
+ }
+ if (err) {
+ ext2_msg(sb, KERN_ERR, "error: insufficient memory");
+ goto failed_mount3;
+ }
+
+#ifdef CONFIG_EXT2_FS_XATTR
+ sbi->s_ea_block_cache = ext2_xattr_create_cache();
+ if (!sbi->s_ea_block_cache) {
+ ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
+ goto failed_mount3;
+ }
+#endif
+ /*
+ * set up enough so that it can read an inode
+ */
+ sb->s_op = &ext2_sops;
+ sb->s_export_op = &ext2_export_ops;
+ sb->s_xattr = ext2_xattr_handlers;
+
+#ifdef CONFIG_QUOTA
+ sb->dq_op = &dquot_operations;
+ sb->s_qcop = &ext2_quotactl_ops;
+ sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
+#endif
+
+ root = ext2_iget(sb, EXT2_ROOT_INO);
+ if (IS_ERR(root)) {
+ ret = PTR_ERR(root);
+ goto failed_mount3;
+ }
+ if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
+ iput(root);
+ ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
+ goto failed_mount3;
+ }
+
+ sb->s_root = d_make_root(root);
+ if (!sb->s_root) {
+ ext2_msg(sb, KERN_ERR, "error: get root inode failed");
+ ret = -ENOMEM;
+ goto failed_mount3;
+ }
+ if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
+ ext2_msg(sb, KERN_WARNING,
+ "warning: mounting ext3 filesystem as ext2");
+ if (ext2_setup_super (sb, es, sb_rdonly(sb)))
+ sb->s_flags |= SB_RDONLY;
+ ext2_write_super(sb);
+ return 0;
+
+cantfind_ext2:
+ if (!silent)
+ ext2_msg(sb, KERN_ERR,
+ "error: can't find an ext2 filesystem on dev %s.",
+ sb->s_id);
+ goto failed_mount;
+failed_mount3:
+ if (sbi->s_ea_block_cache)
+ ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
+ percpu_counter_destroy(&sbi->s_freeblocks_counter);
+ percpu_counter_destroy(&sbi->s_freeinodes_counter);
+ percpu_counter_destroy(&sbi->s_dirs_counter);
+failed_mount2:
+ for (i = 0; i < db_count; i++)
+ brelse(sbi->s_group_desc[i]);
+failed_mount_group_desc:
+ kfree(sbi->s_group_desc);
+ kfree(sbi->s_debts);
+failed_mount:
+ brelse(bh);
+failed_sbi:
+ sb->s_fs_info = NULL;
+ kfree(sbi->s_blockgroup_lock);
+ kfree(sbi);
+failed:
+ fs_put_dax(dax_dev);
+ return ret;
+}
+
+static void ext2_clear_super_error(struct super_block *sb)
+{
+ struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
+
+ if (buffer_write_io_error(sbh)) {
+ /*
+ * Oh, dear. A previous attempt to write the
+ * superblock failed. This could happen because the
+ * USB device was yanked out. Or it could happen to
+ * be a transient write error and maybe the block will
+ * be remapped. Nothing we can do but to retry the
+ * write and hope for the best.
+ */
+ ext2_msg(sb, KERN_ERR,
+ "previous I/O error to superblock detected");
+ clear_buffer_write_io_error(sbh);
+ set_buffer_uptodate(sbh);
+ }
+}
+
+void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
+ int wait)
+{
+ ext2_clear_super_error(sb);
+ spin_lock(&EXT2_SB(sb)->s_lock);
+ es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
+ es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
+ es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
+ /* unlock before we do IO */
+ spin_unlock(&EXT2_SB(sb)->s_lock);
+ mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
+ if (wait)
+ sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
+}
+
+/*
+ * In the second extended file system, it is not necessary to
+ * write the super block since we use a mapping of the
+ * disk super block in a buffer.
+ *
+ * However, this function is still used to set the fs valid
+ * flags to 0. We need to set this flag to 0 since the fs
+ * may have been checked while mounted and e2fsck may have
+ * set s_state to EXT2_VALID_FS after some corrections.
+ */
+static int ext2_sync_fs(struct super_block *sb, int wait)
+{
+ struct ext2_sb_info *sbi = EXT2_SB(sb);
+ struct ext2_super_block *es = EXT2_SB(sb)->s_es;
+
+ /*
+ * Write quota structures to quota file, sync_blockdev() will write
+ * them to disk later
+ */
+ dquot_writeback_dquots(sb, -1);
+
+ spin_lock(&sbi->s_lock);
+ if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
+ ext2_debug("setting valid to 0\n");
+ es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
+ }
+ spin_unlock(&sbi->s_lock);
+ ext2_sync_super(sb, es, wait);
+ return 0;
+}
+
+static int ext2_freeze(struct super_block *sb)
+{
+ struct ext2_sb_info *sbi = EXT2_SB(sb);
+
+ /*
+ * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
+ * because we have unattached inodes and thus filesystem is not fully
+ * consistent.
+ */
+ if (atomic_long_read(&sb->s_remove_count)) {
+ ext2_sync_fs(sb, 1);
+ return 0;
+ }
+ /* Set EXT2_FS_VALID flag */
+ spin_lock(&sbi->s_lock);
+ sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
+ spin_unlock(&sbi->s_lock);
+ ext2_sync_super(sb, sbi->s_es, 1);
+
+ return 0;
+}
+
+static int ext2_unfreeze(struct super_block *sb)
+{
+ /* Just write sb to clear EXT2_VALID_FS flag */
+ ext2_write_super(sb);
+
+ return 0;
+}
+
+static void ext2_write_super(struct super_block *sb)
+{
+ if (!sb_rdonly(sb))
+ ext2_sync_fs(sb, 1);
+}
+
+static int ext2_remount (struct super_block * sb, int * flags, char * data)
+{
+ struct ext2_sb_info * sbi = EXT2_SB(sb);
+ struct ext2_super_block * es;
+ struct ext2_mount_options new_opts;
+ int err;
+
+ sync_filesystem(sb);
+
+ spin_lock(&sbi->s_lock);
+ new_opts.s_mount_opt = sbi->s_mount_opt;
+ new_opts.s_resuid = sbi->s_resuid;
+ new_opts.s_resgid = sbi->s_resgid;
+ spin_unlock(&sbi->s_lock);
+
+ if (!parse_options(data, sb, &new_opts))
+ return -EINVAL;
+
+ spin_lock(&sbi->s_lock);
+ es = sbi->s_es;
+ if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
+ ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
+ "dax flag with busy inodes while remounting");
+ new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
+ }
+ if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
+ goto out_set;
+ if (*flags & SB_RDONLY) {
+ if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
+ !(sbi->s_mount_state & EXT2_VALID_FS))
+ goto out_set;
+
+ /*
+ * OK, we are remounting a valid rw partition rdonly, so set
+ * the rdonly flag and then mark the partition as valid again.
+ */
+ es->s_state = cpu_to_le16(sbi->s_mount_state);
+ es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
+ spin_unlock(&sbi->s_lock);
+
+ err = dquot_suspend(sb, -1);
+ if (err < 0)
+ return err;
+
+ ext2_sync_super(sb, es, 1);
+ } else {
+ __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
+ ~EXT2_FEATURE_RO_COMPAT_SUPP);
+ if (ret) {
+ spin_unlock(&sbi->s_lock);
+ ext2_msg(sb, KERN_WARNING,
+ "warning: couldn't remount RDWR because of "
+ "unsupported optional features (%x).",
+ le32_to_cpu(ret));
+ return -EROFS;
+ }
+ /*
+ * Mounting a RDONLY partition read-write, so reread and
+ * store the current valid flag. (It may have been changed
+ * by e2fsck since we originally mounted the partition.)
+ */
+ sbi->s_mount_state = le16_to_cpu(es->s_state);
+ if (!ext2_setup_super (sb, es, 0))
+ sb->s_flags &= ~SB_RDONLY;
+ spin_unlock(&sbi->s_lock);
+
+ ext2_write_super(sb);
+
+ dquot_resume(sb, -1);
+ }
+
+ spin_lock(&sbi->s_lock);
+out_set:
+ sbi->s_mount_opt = new_opts.s_mount_opt;
+ sbi->s_resuid = new_opts.s_resuid;
+ sbi->s_resgid = new_opts.s_resgid;
+ sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
+ ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? SB_POSIXACL : 0);
+ spin_unlock(&sbi->s_lock);
+
+ return 0;
+}
+
+static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
+{
+ struct super_block *sb = dentry->d_sb;
+ struct ext2_sb_info *sbi = EXT2_SB(sb);
+ struct ext2_super_block *es = sbi->s_es;
+ u64 fsid;
+
+ spin_lock(&sbi->s_lock);
+
+ if (test_opt (sb, MINIX_DF))
+ sbi->s_overhead_last = 0;
+ else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
+ unsigned long i, overhead = 0;
+ smp_rmb();
+
+ /*
+ * Compute the overhead (FS structures). This is constant
+ * for a given filesystem unless the number of block groups
+ * changes so we cache the previous value until it does.
+ */
+
+ /*
+ * All of the blocks before first_data_block are
+ * overhead
+ */
+ overhead = le32_to_cpu(es->s_first_data_block);
+
+ /*
+ * Add the overhead attributed to the superblock and
+ * block group descriptors. If the sparse superblocks
+ * feature is turned on, then not all groups have this.
+ */
+ for (i = 0; i < sbi->s_groups_count; i++)
+ overhead += ext2_bg_has_super(sb, i) +
+ ext2_bg_num_gdb(sb, i);
+
+ /*
+ * Every block group has an inode bitmap, a block
+ * bitmap, and an inode table.
+ */
+ overhead += (sbi->s_groups_count *
+ (2 + sbi->s_itb_per_group));
+ sbi->s_overhead_last = overhead;
+ smp_wmb();
+ sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
+ }
+
+ buf->f_type = EXT2_SUPER_MAGIC;
+ buf->f_bsize = sb->s_blocksize;
+ buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
+ buf->f_bfree = ext2_count_free_blocks(sb);
+ es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
+ buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
+ if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
+ buf->f_bavail = 0;
+ buf->f_files = le32_to_cpu(es->s_inodes_count);
+ buf->f_ffree = ext2_count_free_inodes(sb);
+ es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
+ buf->f_namelen = EXT2_NAME_LEN;
+ fsid = le64_to_cpup((void *)es->s_uuid) ^
+ le64_to_cpup((void *)es->s_uuid + sizeof(u64));
+ buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
+ buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
+ spin_unlock(&sbi->s_lock);
+ return 0;
+}
+
+static struct dentry *ext2_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
+}
+
+#ifdef CONFIG_QUOTA
+
+/* Read data from quotafile - avoid pagecache and such because we cannot afford
+ * acquiring the locks... As quota files are never truncated and quota code
+ * itself serializes the operations (and no one else should touch the files)
+ * we don't have to be afraid of races */
+static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
+ size_t len, loff_t off)
+{
+ struct inode *inode = sb_dqopt(sb)->files[type];
+ sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
+ int err = 0;
+ int offset = off & (sb->s_blocksize - 1);
+ int tocopy;
+ size_t toread;
+ struct buffer_head tmp_bh;
+ struct buffer_head *bh;
+ loff_t i_size = i_size_read(inode);
+
+ if (off > i_size)
+ return 0;
+ if (off+len > i_size)
+ len = i_size-off;
+ toread = len;
+ while (toread > 0) {
+ tocopy = sb->s_blocksize - offset < toread ?
+ sb->s_blocksize - offset : toread;
+
+ tmp_bh.b_state = 0;
+ tmp_bh.b_size = sb->s_blocksize;
+ err = ext2_get_block(inode, blk, &tmp_bh, 0);
+ if (err < 0)
+ return err;
+ if (!buffer_mapped(&tmp_bh)) /* A hole? */
+ memset(data, 0, tocopy);
+ else {
+ bh = sb_bread(sb, tmp_bh.b_blocknr);
+ if (!bh)
+ return -EIO;
+ memcpy(data, bh->b_data+offset, tocopy);
+ brelse(bh);
+ }
+ offset = 0;
+ toread -= tocopy;
+ data += tocopy;
+ blk++;
+ }
+ return len;
+}
+
+/* Write to quotafile */
+static ssize_t ext2_quota_write(struct super_block *sb, int type,
+ const char *data, size_t len, loff_t off)
+{
+ struct inode *inode = sb_dqopt(sb)->files[type];
+ sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
+ int err = 0;
+ int offset = off & (sb->s_blocksize - 1);
+ int tocopy;
+ size_t towrite = len;
+ struct buffer_head tmp_bh;
+ struct buffer_head *bh;
+
+ while (towrite > 0) {
+ tocopy = sb->s_blocksize - offset < towrite ?
+ sb->s_blocksize - offset : towrite;
+
+ tmp_bh.b_state = 0;
+ tmp_bh.b_size = sb->s_blocksize;
+ err = ext2_get_block(inode, blk, &tmp_bh, 1);
+ if (err < 0)
+ goto out;
+ if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
+ bh = sb_bread(sb, tmp_bh.b_blocknr);
+ else
+ bh = sb_getblk(sb, tmp_bh.b_blocknr);
+ if (unlikely(!bh)) {
+ err = -EIO;
+ goto out;
+ }
+ lock_buffer(bh);
+ memcpy(bh->b_data+offset, data, tocopy);
+ flush_dcache_page(bh->b_page);
+ set_buffer_uptodate(bh);
+ mark_buffer_dirty(bh);
+ unlock_buffer(bh);
+ brelse(bh);
+ offset = 0;
+ towrite -= tocopy;
+ data += tocopy;
+ blk++;
+ }
+out:
+ if (len == towrite)
+ return err;
+ if (inode->i_size < off+len-towrite)
+ i_size_write(inode, off+len-towrite);
+ inode_inc_iversion(inode);
+ inode->i_mtime = inode->i_ctime = current_time(inode);
+ mark_inode_dirty(inode);
+ return len - towrite;
+}
+
+static int ext2_quota_on(struct super_block *sb, int type, int format_id,
+ const struct path *path)
+{
+ int err;
+ struct inode *inode;
+
+ err = dquot_quota_on(sb, type, format_id, path);
+ if (err)
+ return err;
+
+ inode = d_inode(path->dentry);
+ inode_lock(inode);
+ EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
+ inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
+ S_NOATIME | S_IMMUTABLE);
+ inode_unlock(inode);
+ mark_inode_dirty(inode);
+
+ return 0;
+}
+
+static int ext2_quota_off(struct super_block *sb, int type)
+{
+ struct inode *inode = sb_dqopt(sb)->files[type];
+ int err;
+
+ if (!inode || !igrab(inode))
+ goto out;
+
+ err = dquot_quota_off(sb, type);
+ if (err)
+ goto out_put;
+
+ inode_lock(inode);
+ EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
+ inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
+ inode_unlock(inode);
+ mark_inode_dirty(inode);
+out_put:
+ iput(inode);
+ return err;
+out:
+ return dquot_quota_off(sb, type);
+}
+
+#endif
+
+static struct file_system_type ext2_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "ext2",
+ .mount = ext2_mount,
+ .kill_sb = kill_block_super,
+ .fs_flags = FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("ext2");
+
+static int __init init_ext2_fs(void)
+{
+ int err;
+
+ err = init_inodecache();
+ if (err)
+ return err;
+ err = register_filesystem(&ext2_fs_type);
+ if (err)
+ goto out;
+ return 0;
+out:
+ destroy_inodecache();
+ return err;
+}
+
+static void __exit exit_ext2_fs(void)
+{
+ unregister_filesystem(&ext2_fs_type);
+ destroy_inodecache();
+}
+
+MODULE_AUTHOR("Remy Card and others");
+MODULE_DESCRIPTION("Second Extended Filesystem");
+MODULE_LICENSE("GPL");
+module_init(init_ext2_fs)
+module_exit(exit_ext2_fs)
diff --git a/fs/ext2/symlink.c b/fs/ext2/symlink.c
new file mode 100644
index 0000000..d5589dd
--- /dev/null
+++ b/fs/ext2/symlink.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/symlink.c
+ *
+ * Only fast symlinks left here - the rest is done by generic code. AV, 1999
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * from
+ *
+ * linux/fs/minix/symlink.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * ext2 symlink handling code
+ */
+
+#include "ext2.h"
+#include "xattr.h"
+
+const struct inode_operations ext2_symlink_inode_operations = {
+ .get_link = page_get_link,
+ .setattr = ext2_setattr,
+#ifdef CONFIG_EXT2_FS_XATTR
+ .listxattr = ext2_listxattr,
+#endif
+};
+
+const struct inode_operations ext2_fast_symlink_inode_operations = {
+ .get_link = simple_get_link,
+ .setattr = ext2_setattr,
+#ifdef CONFIG_EXT2_FS_XATTR
+ .listxattr = ext2_listxattr,
+#endif
+};
diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
new file mode 100644
index 0000000..dd8f10d
--- /dev/null
+++ b/fs/ext2/xattr.c
@@ -0,0 +1,1034 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/xattr.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de>
+ *
+ * Fix by Harrison Xing <harrison@mountainviewdata.com>.
+ * Extended attributes for symlinks and special files added per
+ * suggestion of Luka Renko <luka.renko@hermes.si>.
+ * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
+ * Red Hat Inc.
+ *
+ */
+
+/*
+ * Extended attributes are stored on disk blocks allocated outside of
+ * any inode. The i_file_acl field is then made to point to this allocated
+ * block. If all extended attributes of an inode are identical, these
+ * inodes may share the same extended attribute block. Such situations
+ * are automatically detected by keeping a cache of recent attribute block
+ * numbers and hashes over the block's contents in memory.
+ *
+ *
+ * Extended attribute block layout:
+ *
+ * +------------------+
+ * | header |
+ * | entry 1 | |
+ * | entry 2 | | growing downwards
+ * | entry 3 | v
+ * | four null bytes |
+ * | . . . |
+ * | value 1 | ^
+ * | value 3 | | growing upwards
+ * | value 2 | |
+ * +------------------+
+ *
+ * The block header is followed by multiple entry descriptors. These entry
+ * descriptors are variable in size, and aligned to EXT2_XATTR_PAD
+ * byte boundaries. The entry descriptors are sorted by attribute name,
+ * so that two extended attribute blocks can be compared efficiently.
+ *
+ * Attribute values are aligned to the end of the block, stored in
+ * no specific order. They are also padded to EXT2_XATTR_PAD byte
+ * boundaries. No additional gaps are left between them.
+ *
+ * Locking strategy
+ * ----------------
+ * EXT2_I(inode)->i_file_acl is protected by EXT2_I(inode)->xattr_sem.
+ * EA blocks are only changed if they are exclusive to an inode, so
+ * holding xattr_sem also means that nothing but the EA block's reference
+ * count will change. Multiple writers to an EA block are synchronized
+ * by the bh lock. No more than a single bh lock is held at any time
+ * to avoid deadlocks.
+ */
+
+#include <linux/buffer_head.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/mbcache.h>
+#include <linux/quotaops.h>
+#include <linux/rwsem.h>
+#include <linux/security.h>
+#include "ext2.h"
+#include "xattr.h"
+#include "acl.h"
+
+#define HDR(bh) ((struct ext2_xattr_header *)((bh)->b_data))
+#define ENTRY(ptr) ((struct ext2_xattr_entry *)(ptr))
+#define FIRST_ENTRY(bh) ENTRY(HDR(bh)+1)
+#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
+
+#ifdef EXT2_XATTR_DEBUG
+# define ea_idebug(inode, f...) do { \
+ printk(KERN_DEBUG "inode %s:%ld: ", \
+ inode->i_sb->s_id, inode->i_ino); \
+ printk(f); \
+ printk("\n"); \
+ } while (0)
+# define ea_bdebug(bh, f...) do { \
+ printk(KERN_DEBUG "block %pg:%lu: ", \
+ bh->b_bdev, (unsigned long) bh->b_blocknr); \
+ printk(f); \
+ printk("\n"); \
+ } while (0)
+#else
+# define ea_idebug(f...)
+# define ea_bdebug(f...)
+#endif
+
+static int ext2_xattr_set2(struct inode *, struct buffer_head *,
+ struct ext2_xattr_header *);
+
+static int ext2_xattr_cache_insert(struct mb_cache *, struct buffer_head *);
+static struct buffer_head *ext2_xattr_cache_find(struct inode *,
+ struct ext2_xattr_header *);
+static void ext2_xattr_rehash(struct ext2_xattr_header *,
+ struct ext2_xattr_entry *);
+
+static const struct xattr_handler *ext2_xattr_handler_map[] = {
+ [EXT2_XATTR_INDEX_USER] = &ext2_xattr_user_handler,
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+ [EXT2_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
+ [EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
+#endif
+ [EXT2_XATTR_INDEX_TRUSTED] = &ext2_xattr_trusted_handler,
+#ifdef CONFIG_EXT2_FS_SECURITY
+ [EXT2_XATTR_INDEX_SECURITY] = &ext2_xattr_security_handler,
+#endif
+};
+
+const struct xattr_handler *ext2_xattr_handlers[] = {
+ &ext2_xattr_user_handler,
+ &ext2_xattr_trusted_handler,
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+ &posix_acl_access_xattr_handler,
+ &posix_acl_default_xattr_handler,
+#endif
+#ifdef CONFIG_EXT2_FS_SECURITY
+ &ext2_xattr_security_handler,
+#endif
+ NULL
+};
+
+#define EA_BLOCK_CACHE(inode) (EXT2_SB(inode->i_sb)->s_ea_block_cache)
+
+static inline const struct xattr_handler *
+ext2_xattr_handler(int name_index)
+{
+ const struct xattr_handler *handler = NULL;
+
+ if (name_index > 0 && name_index < ARRAY_SIZE(ext2_xattr_handler_map))
+ handler = ext2_xattr_handler_map[name_index];
+ return handler;
+}
+
+/*
+ * ext2_xattr_get()
+ *
+ * Copy an extended attribute into the buffer
+ * provided, or compute the buffer size required.
+ * Buffer is NULL to compute the size of the buffer required.
+ *
+ * Returns a negative error number on failure, or the number of bytes
+ * used / required on success.
+ */
+int
+ext2_xattr_get(struct inode *inode, int name_index, const char *name,
+ void *buffer, size_t buffer_size)
+{
+ struct buffer_head *bh = NULL;
+ struct ext2_xattr_entry *entry;
+ size_t name_len, size;
+ char *end;
+ int error;
+ struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
+
+ ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
+ name_index, name, buffer, (long)buffer_size);
+
+ if (name == NULL)
+ return -EINVAL;
+ name_len = strlen(name);
+ if (name_len > 255)
+ return -ERANGE;
+
+ down_read(&EXT2_I(inode)->xattr_sem);
+ error = -ENODATA;
+ if (!EXT2_I(inode)->i_file_acl)
+ goto cleanup;
+ ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl);
+ bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
+ error = -EIO;
+ if (!bh)
+ goto cleanup;
+ ea_bdebug(bh, "b_count=%d, refcount=%d",
+ atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
+ end = bh->b_data + bh->b_size;
+ if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
+ HDR(bh)->h_blocks != cpu_to_le32(1)) {
+bad_block: ext2_error(inode->i_sb, "ext2_xattr_get",
+ "inode %ld: bad block %d", inode->i_ino,
+ EXT2_I(inode)->i_file_acl);
+ error = -EIO;
+ goto cleanup;
+ }
+
+ /* find named attribute */
+ entry = FIRST_ENTRY(bh);
+ while (!IS_LAST_ENTRY(entry)) {
+ struct ext2_xattr_entry *next =
+ EXT2_XATTR_NEXT(entry);
+ if ((char *)next >= end)
+ goto bad_block;
+ if (name_index == entry->e_name_index &&
+ name_len == entry->e_name_len &&
+ memcmp(name, entry->e_name, name_len) == 0)
+ goto found;
+ entry = next;
+ }
+ if (ext2_xattr_cache_insert(ea_block_cache, bh))
+ ea_idebug(inode, "cache insert failed");
+ error = -ENODATA;
+ goto cleanup;
+found:
+ /* check the buffer size */
+ if (entry->e_value_block != 0)
+ goto bad_block;
+ size = le32_to_cpu(entry->e_value_size);
+ if (size > inode->i_sb->s_blocksize ||
+ le16_to_cpu(entry->e_value_offs) + size > inode->i_sb->s_blocksize)
+ goto bad_block;
+
+ if (ext2_xattr_cache_insert(ea_block_cache, bh))
+ ea_idebug(inode, "cache insert failed");
+ if (buffer) {
+ error = -ERANGE;
+ if (size > buffer_size)
+ goto cleanup;
+ /* return value of attribute */
+ memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
+ size);
+ }
+ error = size;
+
+cleanup:
+ brelse(bh);
+ up_read(&EXT2_I(inode)->xattr_sem);
+
+ return error;
+}
+
+/*
+ * ext2_xattr_list()
+ *
+ * Copy a list of attribute names into the buffer
+ * provided, or compute the buffer size required.
+ * Buffer is NULL to compute the size of the buffer required.
+ *
+ * Returns a negative error number on failure, or the number of bytes
+ * used / required on success.
+ */
+static int
+ext2_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+ struct inode *inode = d_inode(dentry);
+ struct buffer_head *bh = NULL;
+ struct ext2_xattr_entry *entry;
+ char *end;
+ size_t rest = buffer_size;
+ int error;
+ struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
+
+ ea_idebug(inode, "buffer=%p, buffer_size=%ld",
+ buffer, (long)buffer_size);
+
+ down_read(&EXT2_I(inode)->xattr_sem);
+ error = 0;
+ if (!EXT2_I(inode)->i_file_acl)
+ goto cleanup;
+ ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl);
+ bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
+ error = -EIO;
+ if (!bh)
+ goto cleanup;
+ ea_bdebug(bh, "b_count=%d, refcount=%d",
+ atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
+ end = bh->b_data + bh->b_size;
+ if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
+ HDR(bh)->h_blocks != cpu_to_le32(1)) {
+bad_block: ext2_error(inode->i_sb, "ext2_xattr_list",
+ "inode %ld: bad block %d", inode->i_ino,
+ EXT2_I(inode)->i_file_acl);
+ error = -EIO;
+ goto cleanup;
+ }
+
+ /* check the on-disk data structure */
+ entry = FIRST_ENTRY(bh);
+ while (!IS_LAST_ENTRY(entry)) {
+ struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(entry);
+
+ if ((char *)next >= end)
+ goto bad_block;
+ entry = next;
+ }
+ if (ext2_xattr_cache_insert(ea_block_cache, bh))
+ ea_idebug(inode, "cache insert failed");
+
+ /* list the attribute names */
+ for (entry = FIRST_ENTRY(bh); !IS_LAST_ENTRY(entry);
+ entry = EXT2_XATTR_NEXT(entry)) {
+ const struct xattr_handler *handler =
+ ext2_xattr_handler(entry->e_name_index);
+
+ if (handler && (!handler->list || handler->list(dentry))) {
+ const char *prefix = handler->prefix ?: handler->name;
+ size_t prefix_len = strlen(prefix);
+ size_t size = prefix_len + entry->e_name_len + 1;
+
+ if (buffer) {
+ if (size > rest) {
+ error = -ERANGE;
+ goto cleanup;
+ }
+ memcpy(buffer, prefix, prefix_len);
+ buffer += prefix_len;
+ memcpy(buffer, entry->e_name, entry->e_name_len);
+ buffer += entry->e_name_len;
+ *buffer++ = 0;
+ }
+ rest -= size;
+ }
+ }
+ error = buffer_size - rest; /* total size */
+
+cleanup:
+ brelse(bh);
+ up_read(&EXT2_I(inode)->xattr_sem);
+
+ return error;
+}
+
+/*
+ * Inode operation listxattr()
+ *
+ * d_inode(dentry)->i_mutex: don't care
+ */
+ssize_t
+ext2_listxattr(struct dentry *dentry, char *buffer, size_t size)
+{
+ return ext2_xattr_list(dentry, buffer, size);
+}
+
+/*
+ * If the EXT2_FEATURE_COMPAT_EXT_ATTR feature of this file system is
+ * not set, set it.
+ */
+static void ext2_xattr_update_super_block(struct super_block *sb)
+{
+ if (EXT2_HAS_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR))
+ return;
+
+ spin_lock(&EXT2_SB(sb)->s_lock);
+ EXT2_SET_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR);
+ spin_unlock(&EXT2_SB(sb)->s_lock);
+ mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
+}
+
+/*
+ * ext2_xattr_set()
+ *
+ * Create, replace or remove an extended attribute for this inode. Value
+ * is NULL to remove an existing extended attribute, and non-NULL to
+ * either replace an existing extended attribute, or create a new extended
+ * attribute. The flags XATTR_REPLACE and XATTR_CREATE
+ * specify that an extended attribute must exist and must not exist
+ * previous to the call, respectively.
+ *
+ * Returns 0, or a negative error number on failure.
+ */
+int
+ext2_xattr_set(struct inode *inode, int name_index, const char *name,
+ const void *value, size_t value_len, int flags)
+{
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *bh = NULL;
+ struct ext2_xattr_header *header = NULL;
+ struct ext2_xattr_entry *here, *last;
+ size_t name_len, free, min_offs = sb->s_blocksize;
+ int not_found = 1, error;
+ char *end;
+
+ /*
+ * header -- Points either into bh, or to a temporarily
+ * allocated buffer.
+ * here -- The named entry found, or the place for inserting, within
+ * the block pointed to by header.
+ * last -- Points right after the last named entry within the block
+ * pointed to by header.
+ * min_offs -- The offset of the first value (values are aligned
+ * towards the end of the block).
+ * end -- Points right after the block pointed to by header.
+ */
+
+ ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
+ name_index, name, value, (long)value_len);
+
+ if (value == NULL)
+ value_len = 0;
+ if (name == NULL)
+ return -EINVAL;
+ name_len = strlen(name);
+ if (name_len > 255 || value_len > sb->s_blocksize)
+ return -ERANGE;
+ down_write(&EXT2_I(inode)->xattr_sem);
+ if (EXT2_I(inode)->i_file_acl) {
+ /* The inode already has an extended attribute block. */
+ bh = sb_bread(sb, EXT2_I(inode)->i_file_acl);
+ error = -EIO;
+ if (!bh)
+ goto cleanup;
+ ea_bdebug(bh, "b_count=%d, refcount=%d",
+ atomic_read(&(bh->b_count)),
+ le32_to_cpu(HDR(bh)->h_refcount));
+ header = HDR(bh);
+ end = bh->b_data + bh->b_size;
+ if (header->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
+ header->h_blocks != cpu_to_le32(1)) {
+bad_block: ext2_error(sb, "ext2_xattr_set",
+ "inode %ld: bad block %d", inode->i_ino,
+ EXT2_I(inode)->i_file_acl);
+ error = -EIO;
+ goto cleanup;
+ }
+ /* Find the named attribute. */
+ here = FIRST_ENTRY(bh);
+ while (!IS_LAST_ENTRY(here)) {
+ struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(here);
+ if ((char *)next >= end)
+ goto bad_block;
+ if (!here->e_value_block && here->e_value_size) {
+ size_t offs = le16_to_cpu(here->e_value_offs);
+ if (offs < min_offs)
+ min_offs = offs;
+ }
+ not_found = name_index - here->e_name_index;
+ if (!not_found)
+ not_found = name_len - here->e_name_len;
+ if (!not_found)
+ not_found = memcmp(name, here->e_name,name_len);
+ if (not_found <= 0)
+ break;
+ here = next;
+ }
+ last = here;
+ /* We still need to compute min_offs and last. */
+ while (!IS_LAST_ENTRY(last)) {
+ struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(last);
+ if ((char *)next >= end)
+ goto bad_block;
+ if (!last->e_value_block && last->e_value_size) {
+ size_t offs = le16_to_cpu(last->e_value_offs);
+ if (offs < min_offs)
+ min_offs = offs;
+ }
+ last = next;
+ }
+
+ /* Check whether we have enough space left. */
+ free = min_offs - ((char*)last - (char*)header) - sizeof(__u32);
+ } else {
+ /* We will use a new extended attribute block. */
+ free = sb->s_blocksize -
+ sizeof(struct ext2_xattr_header) - sizeof(__u32);
+ here = last = NULL; /* avoid gcc uninitialized warning. */
+ }
+
+ if (not_found) {
+ /* Request to remove a nonexistent attribute? */
+ error = -ENODATA;
+ if (flags & XATTR_REPLACE)
+ goto cleanup;
+ error = 0;
+ if (value == NULL)
+ goto cleanup;
+ } else {
+ /* Request to create an existing attribute? */
+ error = -EEXIST;
+ if (flags & XATTR_CREATE)
+ goto cleanup;
+ if (!here->e_value_block && here->e_value_size) {
+ size_t size = le32_to_cpu(here->e_value_size);
+
+ if (le16_to_cpu(here->e_value_offs) + size >
+ sb->s_blocksize || size > sb->s_blocksize)
+ goto bad_block;
+ free += EXT2_XATTR_SIZE(size);
+ }
+ free += EXT2_XATTR_LEN(name_len);
+ }
+ error = -ENOSPC;
+ if (free < EXT2_XATTR_LEN(name_len) + EXT2_XATTR_SIZE(value_len))
+ goto cleanup;
+
+ /* Here we know that we can set the new attribute. */
+
+ if (header) {
+ /* assert(header == HDR(bh)); */
+ lock_buffer(bh);
+ if (header->h_refcount == cpu_to_le32(1)) {
+ __u32 hash = le32_to_cpu(header->h_hash);
+
+ ea_bdebug(bh, "modifying in-place");
+ /*
+ * This must happen under buffer lock for
+ * ext2_xattr_set2() to reliably detect modified block
+ */
+ mb_cache_entry_delete(EA_BLOCK_CACHE(inode), hash,
+ bh->b_blocknr);
+
+ /* keep the buffer locked while modifying it. */
+ } else {
+ int offset;
+
+ unlock_buffer(bh);
+ ea_bdebug(bh, "cloning");
+ header = kmalloc(bh->b_size, GFP_KERNEL);
+ error = -ENOMEM;
+ if (header == NULL)
+ goto cleanup;
+ memcpy(header, HDR(bh), bh->b_size);
+ header->h_refcount = cpu_to_le32(1);
+
+ offset = (char *)here - bh->b_data;
+ here = ENTRY((char *)header + offset);
+ offset = (char *)last - bh->b_data;
+ last = ENTRY((char *)header + offset);
+ }
+ } else {
+ /* Allocate a buffer where we construct the new block. */
+ header = kzalloc(sb->s_blocksize, GFP_KERNEL);
+ error = -ENOMEM;
+ if (header == NULL)
+ goto cleanup;
+ end = (char *)header + sb->s_blocksize;
+ header->h_magic = cpu_to_le32(EXT2_XATTR_MAGIC);
+ header->h_blocks = header->h_refcount = cpu_to_le32(1);
+ last = here = ENTRY(header+1);
+ }
+
+ /* Iff we are modifying the block in-place, bh is locked here. */
+
+ if (not_found) {
+ /* Insert the new name. */
+ size_t size = EXT2_XATTR_LEN(name_len);
+ size_t rest = (char *)last - (char *)here;
+ memmove((char *)here + size, here, rest);
+ memset(here, 0, size);
+ here->e_name_index = name_index;
+ here->e_name_len = name_len;
+ memcpy(here->e_name, name, name_len);
+ } else {
+ if (!here->e_value_block && here->e_value_size) {
+ char *first_val = (char *)header + min_offs;
+ size_t offs = le16_to_cpu(here->e_value_offs);
+ char *val = (char *)header + offs;
+ size_t size = EXT2_XATTR_SIZE(
+ le32_to_cpu(here->e_value_size));
+
+ if (size == EXT2_XATTR_SIZE(value_len)) {
+ /* The old and the new value have the same
+ size. Just replace. */
+ here->e_value_size = cpu_to_le32(value_len);
+ memset(val + size - EXT2_XATTR_PAD, 0,
+ EXT2_XATTR_PAD); /* Clear pad bytes. */
+ memcpy(val, value, value_len);
+ goto skip_replace;
+ }
+
+ /* Remove the old value. */
+ memmove(first_val + size, first_val, val - first_val);
+ memset(first_val, 0, size);
+ here->e_value_offs = 0;
+ min_offs += size;
+
+ /* Adjust all value offsets. */
+ last = ENTRY(header+1);
+ while (!IS_LAST_ENTRY(last)) {
+ size_t o = le16_to_cpu(last->e_value_offs);
+ if (!last->e_value_block && o < offs)
+ last->e_value_offs =
+ cpu_to_le16(o + size);
+ last = EXT2_XATTR_NEXT(last);
+ }
+ }
+ if (value == NULL) {
+ /* Remove the old name. */
+ size_t size = EXT2_XATTR_LEN(name_len);
+ last = ENTRY((char *)last - size);
+ memmove(here, (char*)here + size,
+ (char*)last - (char*)here);
+ memset(last, 0, size);
+ }
+ }
+
+ if (value != NULL) {
+ /* Insert the new value. */
+ here->e_value_size = cpu_to_le32(value_len);
+ if (value_len) {
+ size_t size = EXT2_XATTR_SIZE(value_len);
+ char *val = (char *)header + min_offs - size;
+ here->e_value_offs =
+ cpu_to_le16((char *)val - (char *)header);
+ memset(val + size - EXT2_XATTR_PAD, 0,
+ EXT2_XATTR_PAD); /* Clear the pad bytes. */
+ memcpy(val, value, value_len);
+ }
+ }
+
+skip_replace:
+ if (IS_LAST_ENTRY(ENTRY(header+1))) {
+ /* This block is now empty. */
+ if (bh && header == HDR(bh))
+ unlock_buffer(bh); /* we were modifying in-place. */
+ error = ext2_xattr_set2(inode, bh, NULL);
+ } else {
+ ext2_xattr_rehash(header, here);
+ if (bh && header == HDR(bh))
+ unlock_buffer(bh); /* we were modifying in-place. */
+ error = ext2_xattr_set2(inode, bh, header);
+ }
+
+cleanup:
+ if (!(bh && header == HDR(bh)))
+ kfree(header);
+ brelse(bh);
+ up_write(&EXT2_I(inode)->xattr_sem);
+
+ return error;
+}
+
+/*
+ * Second half of ext2_xattr_set(): Update the file system.
+ */
+static int
+ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh,
+ struct ext2_xattr_header *header)
+{
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *new_bh = NULL;
+ int error;
+ struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
+
+ if (header) {
+ new_bh = ext2_xattr_cache_find(inode, header);
+ if (new_bh) {
+ /* We found an identical block in the cache. */
+ if (new_bh == old_bh) {
+ ea_bdebug(new_bh, "keeping this block");
+ } else {
+ /* The old block is released after updating
+ the inode. */
+ ea_bdebug(new_bh, "reusing block");
+
+ error = dquot_alloc_block(inode, 1);
+ if (error) {
+ unlock_buffer(new_bh);
+ goto cleanup;
+ }
+ le32_add_cpu(&HDR(new_bh)->h_refcount, 1);
+ ea_bdebug(new_bh, "refcount now=%d",
+ le32_to_cpu(HDR(new_bh)->h_refcount));
+ }
+ unlock_buffer(new_bh);
+ } else if (old_bh && header == HDR(old_bh)) {
+ /* Keep this block. No need to lock the block as we
+ don't need to change the reference count. */
+ new_bh = old_bh;
+ get_bh(new_bh);
+ ext2_xattr_cache_insert(ea_block_cache, new_bh);
+ } else {
+ /* We need to allocate a new block */
+ ext2_fsblk_t goal = ext2_group_first_block_no(sb,
+ EXT2_I(inode)->i_block_group);
+ int block = ext2_new_block(inode, goal, &error);
+ if (error)
+ goto cleanup;
+ ea_idebug(inode, "creating block %d", block);
+
+ new_bh = sb_getblk(sb, block);
+ if (unlikely(!new_bh)) {
+ ext2_free_blocks(inode, block, 1);
+ mark_inode_dirty(inode);
+ error = -ENOMEM;
+ goto cleanup;
+ }
+ lock_buffer(new_bh);
+ memcpy(new_bh->b_data, header, new_bh->b_size);
+ set_buffer_uptodate(new_bh);
+ unlock_buffer(new_bh);
+ ext2_xattr_cache_insert(ea_block_cache, new_bh);
+
+ ext2_xattr_update_super_block(sb);
+ }
+ mark_buffer_dirty(new_bh);
+ if (IS_SYNC(inode)) {
+ sync_dirty_buffer(new_bh);
+ error = -EIO;
+ if (buffer_req(new_bh) && !buffer_uptodate(new_bh))
+ goto cleanup;
+ }
+ }
+
+ /* Update the inode. */
+ EXT2_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
+ inode->i_ctime = current_time(inode);
+ if (IS_SYNC(inode)) {
+ error = sync_inode_metadata(inode, 1);
+ /* In case sync failed due to ENOSPC the inode was actually
+ * written (only some dirty data were not) so we just proceed
+ * as if nothing happened and cleanup the unused block */
+ if (error && error != -ENOSPC) {
+ if (new_bh && new_bh != old_bh) {
+ dquot_free_block_nodirty(inode, 1);
+ mark_inode_dirty(inode);
+ }
+ goto cleanup;
+ }
+ } else
+ mark_inode_dirty(inode);
+
+ error = 0;
+ if (old_bh && old_bh != new_bh) {
+ /*
+ * If there was an old block and we are no longer using it,
+ * release the old block.
+ */
+ lock_buffer(old_bh);
+ if (HDR(old_bh)->h_refcount == cpu_to_le32(1)) {
+ __u32 hash = le32_to_cpu(HDR(old_bh)->h_hash);
+
+ /*
+ * This must happen under buffer lock for
+ * ext2_xattr_set2() to reliably detect freed block
+ */
+ mb_cache_entry_delete(ea_block_cache, hash,
+ old_bh->b_blocknr);
+ /* Free the old block. */
+ ea_bdebug(old_bh, "freeing");
+ ext2_free_blocks(inode, old_bh->b_blocknr, 1);
+ mark_inode_dirty(inode);
+ /* We let our caller release old_bh, so we
+ * need to duplicate the buffer before. */
+ get_bh(old_bh);
+ bforget(old_bh);
+ } else {
+ /* Decrement the refcount only. */
+ le32_add_cpu(&HDR(old_bh)->h_refcount, -1);
+ dquot_free_block_nodirty(inode, 1);
+ mark_inode_dirty(inode);
+ mark_buffer_dirty(old_bh);
+ ea_bdebug(old_bh, "refcount now=%d",
+ le32_to_cpu(HDR(old_bh)->h_refcount));
+ }
+ unlock_buffer(old_bh);
+ }
+
+cleanup:
+ brelse(new_bh);
+
+ return error;
+}
+
+/*
+ * ext2_xattr_delete_inode()
+ *
+ * Free extended attribute resources associated with this inode. This
+ * is called immediately before an inode is freed.
+ */
+void
+ext2_xattr_delete_inode(struct inode *inode)
+{
+ struct buffer_head *bh = NULL;
+ struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb);
+
+ down_write(&EXT2_I(inode)->xattr_sem);
+ if (!EXT2_I(inode)->i_file_acl)
+ goto cleanup;
+
+ if (!ext2_data_block_valid(sbi, EXT2_I(inode)->i_file_acl, 0)) {
+ ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
+ "inode %ld: xattr block %d is out of data blocks range",
+ inode->i_ino, EXT2_I(inode)->i_file_acl);
+ goto cleanup;
+ }
+
+ bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
+ if (!bh) {
+ ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
+ "inode %ld: block %d read error", inode->i_ino,
+ EXT2_I(inode)->i_file_acl);
+ goto cleanup;
+ }
+ ea_bdebug(bh, "b_count=%d", atomic_read(&(bh->b_count)));
+ if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
+ HDR(bh)->h_blocks != cpu_to_le32(1)) {
+ ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
+ "inode %ld: bad block %d", inode->i_ino,
+ EXT2_I(inode)->i_file_acl);
+ goto cleanup;
+ }
+ lock_buffer(bh);
+ if (HDR(bh)->h_refcount == cpu_to_le32(1)) {
+ __u32 hash = le32_to_cpu(HDR(bh)->h_hash);
+
+ /*
+ * This must happen under buffer lock for ext2_xattr_set2() to
+ * reliably detect freed block
+ */
+ mb_cache_entry_delete(EA_BLOCK_CACHE(inode), hash,
+ bh->b_blocknr);
+ ext2_free_blocks(inode, EXT2_I(inode)->i_file_acl, 1);
+ get_bh(bh);
+ bforget(bh);
+ unlock_buffer(bh);
+ } else {
+ le32_add_cpu(&HDR(bh)->h_refcount, -1);
+ ea_bdebug(bh, "refcount now=%d",
+ le32_to_cpu(HDR(bh)->h_refcount));
+ unlock_buffer(bh);
+ mark_buffer_dirty(bh);
+ if (IS_SYNC(inode))
+ sync_dirty_buffer(bh);
+ dquot_free_block_nodirty(inode, 1);
+ }
+ EXT2_I(inode)->i_file_acl = 0;
+
+cleanup:
+ brelse(bh);
+ up_write(&EXT2_I(inode)->xattr_sem);
+}
+
+/*
+ * ext2_xattr_cache_insert()
+ *
+ * Create a new entry in the extended attribute cache, and insert
+ * it unless such an entry is already in the cache.
+ *
+ * Returns 0, or a negative error number on failure.
+ */
+static int
+ext2_xattr_cache_insert(struct mb_cache *cache, struct buffer_head *bh)
+{
+ __u32 hash = le32_to_cpu(HDR(bh)->h_hash);
+ int error;
+
+ error = mb_cache_entry_create(cache, GFP_NOFS, hash, bh->b_blocknr, 1);
+ if (error) {
+ if (error == -EBUSY) {
+ ea_bdebug(bh, "already in cache (%d cache entries)",
+ atomic_read(&ext2_xattr_cache->c_entry_count));
+ error = 0;
+ }
+ } else
+ ea_bdebug(bh, "inserting [%x]", (int)hash);
+ return error;
+}
+
+/*
+ * ext2_xattr_cmp()
+ *
+ * Compare two extended attribute blocks for equality.
+ *
+ * Returns 0 if the blocks are equal, 1 if they differ, and
+ * a negative error number on errors.
+ */
+static int
+ext2_xattr_cmp(struct ext2_xattr_header *header1,
+ struct ext2_xattr_header *header2)
+{
+ struct ext2_xattr_entry *entry1, *entry2;
+
+ entry1 = ENTRY(header1+1);
+ entry2 = ENTRY(header2+1);
+ while (!IS_LAST_ENTRY(entry1)) {
+ if (IS_LAST_ENTRY(entry2))
+ return 1;
+ if (entry1->e_hash != entry2->e_hash ||
+ entry1->e_name_index != entry2->e_name_index ||
+ entry1->e_name_len != entry2->e_name_len ||
+ entry1->e_value_size != entry2->e_value_size ||
+ memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
+ return 1;
+ if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
+ return -EIO;
+ if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
+ (char *)header2 + le16_to_cpu(entry2->e_value_offs),
+ le32_to_cpu(entry1->e_value_size)))
+ return 1;
+
+ entry1 = EXT2_XATTR_NEXT(entry1);
+ entry2 = EXT2_XATTR_NEXT(entry2);
+ }
+ if (!IS_LAST_ENTRY(entry2))
+ return 1;
+ return 0;
+}
+
+/*
+ * ext2_xattr_cache_find()
+ *
+ * Find an identical extended attribute block.
+ *
+ * Returns a locked buffer head to the block found, or NULL if such
+ * a block was not found or an error occurred.
+ */
+static struct buffer_head *
+ext2_xattr_cache_find(struct inode *inode, struct ext2_xattr_header *header)
+{
+ __u32 hash = le32_to_cpu(header->h_hash);
+ struct mb_cache_entry *ce;
+ struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
+
+ if (!header->h_hash)
+ return NULL; /* never share */
+ ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
+again:
+ ce = mb_cache_entry_find_first(ea_block_cache, hash);
+ while (ce) {
+ struct buffer_head *bh;
+
+ bh = sb_bread(inode->i_sb, ce->e_value);
+ if (!bh) {
+ ext2_error(inode->i_sb, "ext2_xattr_cache_find",
+ "inode %ld: block %ld read error",
+ inode->i_ino, (unsigned long) ce->e_value);
+ } else {
+ lock_buffer(bh);
+ /*
+ * We have to be careful about races with freeing or
+ * rehashing of xattr block. Once we hold buffer lock
+ * xattr block's state is stable so we can check
+ * whether the block got freed / rehashed or not.
+ * Since we unhash mbcache entry under buffer lock when
+ * freeing / rehashing xattr block, checking whether
+ * entry is still hashed is reliable.
+ */
+ if (hlist_bl_unhashed(&ce->e_hash_list)) {
+ mb_cache_entry_put(ea_block_cache, ce);
+ unlock_buffer(bh);
+ brelse(bh);
+ goto again;
+ } else if (le32_to_cpu(HDR(bh)->h_refcount) >
+ EXT2_XATTR_REFCOUNT_MAX) {
+ ea_idebug(inode, "block %ld refcount %d>%d",
+ (unsigned long) ce->e_value,
+ le32_to_cpu(HDR(bh)->h_refcount),
+ EXT2_XATTR_REFCOUNT_MAX);
+ } else if (!ext2_xattr_cmp(header, HDR(bh))) {
+ ea_bdebug(bh, "b_count=%d",
+ atomic_read(&(bh->b_count)));
+ mb_cache_entry_touch(ea_block_cache, ce);
+ mb_cache_entry_put(ea_block_cache, ce);
+ return bh;
+ }
+ unlock_buffer(bh);
+ brelse(bh);
+ }
+ ce = mb_cache_entry_find_next(ea_block_cache, ce);
+ }
+ return NULL;
+}
+
+#define NAME_HASH_SHIFT 5
+#define VALUE_HASH_SHIFT 16
+
+/*
+ * ext2_xattr_hash_entry()
+ *
+ * Compute the hash of an extended attribute.
+ */
+static inline void ext2_xattr_hash_entry(struct ext2_xattr_header *header,
+ struct ext2_xattr_entry *entry)
+{
+ __u32 hash = 0;
+ char *name = entry->e_name;
+ int n;
+
+ for (n=0; n < entry->e_name_len; n++) {
+ hash = (hash << NAME_HASH_SHIFT) ^
+ (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
+ *name++;
+ }
+
+ if (entry->e_value_block == 0 && entry->e_value_size != 0) {
+ __le32 *value = (__le32 *)((char *)header +
+ le16_to_cpu(entry->e_value_offs));
+ for (n = (le32_to_cpu(entry->e_value_size) +
+ EXT2_XATTR_ROUND) >> EXT2_XATTR_PAD_BITS; n; n--) {
+ hash = (hash << VALUE_HASH_SHIFT) ^
+ (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
+ le32_to_cpu(*value++);
+ }
+ }
+ entry->e_hash = cpu_to_le32(hash);
+}
+
+#undef NAME_HASH_SHIFT
+#undef VALUE_HASH_SHIFT
+
+#define BLOCK_HASH_SHIFT 16
+
+/*
+ * ext2_xattr_rehash()
+ *
+ * Re-compute the extended attribute hash value after an entry has changed.
+ */
+static void ext2_xattr_rehash(struct ext2_xattr_header *header,
+ struct ext2_xattr_entry *entry)
+{
+ struct ext2_xattr_entry *here;
+ __u32 hash = 0;
+
+ ext2_xattr_hash_entry(header, entry);
+ here = ENTRY(header+1);
+ while (!IS_LAST_ENTRY(here)) {
+ if (!here->e_hash) {
+ /* Block is not shared if an entry's hash value == 0 */
+ hash = 0;
+ break;
+ }
+ hash = (hash << BLOCK_HASH_SHIFT) ^
+ (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
+ le32_to_cpu(here->e_hash);
+ here = EXT2_XATTR_NEXT(here);
+ }
+ header->h_hash = cpu_to_le32(hash);
+}
+
+#undef BLOCK_HASH_SHIFT
+
+#define HASH_BUCKET_BITS 10
+
+struct mb_cache *ext2_xattr_create_cache(void)
+{
+ return mb_cache_create(HASH_BUCKET_BITS);
+}
+
+void ext2_xattr_destroy_cache(struct mb_cache *cache)
+{
+ if (cache)
+ mb_cache_destroy(cache);
+}
diff --git a/fs/ext2/xattr.h b/fs/ext2/xattr.h
new file mode 100644
index 0000000..cee888c
--- /dev/null
+++ b/fs/ext2/xattr.h
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ File: linux/ext2_xattr.h
+
+ On-disk format of extended attributes for the ext2 filesystem.
+
+ (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+*/
+
+#include <linux/init.h>
+#include <linux/xattr.h>
+
+/* Magic value in attribute blocks */
+#define EXT2_XATTR_MAGIC 0xEA020000
+
+/* Maximum number of references to one attribute block */
+#define EXT2_XATTR_REFCOUNT_MAX 1024
+
+/* Name indexes */
+#define EXT2_XATTR_INDEX_USER 1
+#define EXT2_XATTR_INDEX_POSIX_ACL_ACCESS 2
+#define EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT 3
+#define EXT2_XATTR_INDEX_TRUSTED 4
+#define EXT2_XATTR_INDEX_LUSTRE 5
+#define EXT2_XATTR_INDEX_SECURITY 6
+
+struct ext2_xattr_header {
+ __le32 h_magic; /* magic number for identification */
+ __le32 h_refcount; /* reference count */
+ __le32 h_blocks; /* number of disk blocks used */
+ __le32 h_hash; /* hash value of all attributes */
+ __u32 h_reserved[4]; /* zero right now */
+};
+
+struct ext2_xattr_entry {
+ __u8 e_name_len; /* length of name */
+ __u8 e_name_index; /* attribute name index */
+ __le16 e_value_offs; /* offset in disk block of value */
+ __le32 e_value_block; /* disk block attribute is stored on (n/i) */
+ __le32 e_value_size; /* size of attribute value */
+ __le32 e_hash; /* hash value of name and value */
+ char e_name[0]; /* attribute name */
+};
+
+#define EXT2_XATTR_PAD_BITS 2
+#define EXT2_XATTR_PAD (1<<EXT2_XATTR_PAD_BITS)
+#define EXT2_XATTR_ROUND (EXT2_XATTR_PAD-1)
+#define EXT2_XATTR_LEN(name_len) \
+ (((name_len) + EXT2_XATTR_ROUND + \
+ sizeof(struct ext2_xattr_entry)) & ~EXT2_XATTR_ROUND)
+#define EXT2_XATTR_NEXT(entry) \
+ ( (struct ext2_xattr_entry *)( \
+ (char *)(entry) + EXT2_XATTR_LEN((entry)->e_name_len)) )
+#define EXT2_XATTR_SIZE(size) \
+ (((size) + EXT2_XATTR_ROUND) & ~EXT2_XATTR_ROUND)
+
+struct mb_cache;
+
+# ifdef CONFIG_EXT2_FS_XATTR
+
+extern const struct xattr_handler ext2_xattr_user_handler;
+extern const struct xattr_handler ext2_xattr_trusted_handler;
+extern const struct xattr_handler ext2_xattr_security_handler;
+
+extern ssize_t ext2_listxattr(struct dentry *, char *, size_t);
+
+extern int ext2_xattr_get(struct inode *, int, const char *, void *, size_t);
+extern int ext2_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
+
+extern void ext2_xattr_delete_inode(struct inode *);
+
+extern struct mb_cache *ext2_xattr_create_cache(void);
+extern void ext2_xattr_destroy_cache(struct mb_cache *cache);
+
+extern const struct xattr_handler *ext2_xattr_handlers[];
+
+# else /* CONFIG_EXT2_FS_XATTR */
+
+static inline int
+ext2_xattr_get(struct inode *inode, int name_index,
+ const char *name, void *buffer, size_t size)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int
+ext2_xattr_set(struct inode *inode, int name_index, const char *name,
+ const void *value, size_t size, int flags)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline void
+ext2_xattr_delete_inode(struct inode *inode)
+{
+}
+
+static inline void ext2_xattr_destroy_cache(struct mb_cache *cache)
+{
+}
+
+#define ext2_xattr_handlers NULL
+
+# endif /* CONFIG_EXT2_FS_XATTR */
+
+#ifdef CONFIG_EXT2_FS_SECURITY
+extern int ext2_init_security(struct inode *inode, struct inode *dir,
+ const struct qstr *qstr);
+#else
+static inline int ext2_init_security(struct inode *inode, struct inode *dir,
+ const struct qstr *qstr)
+{
+ return 0;
+}
+#endif
diff --git a/fs/ext2/xattr_security.c b/fs/ext2/xattr_security.c
new file mode 100644
index 0000000..9a682e4
--- /dev/null
+++ b/fs/ext2/xattr_security.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/xattr_security.c
+ * Handler for storing security labels as extended attributes.
+ */
+
+#include "ext2.h"
+#include <linux/security.h>
+#include "xattr.h"
+
+static int
+ext2_xattr_security_get(const struct xattr_handler *handler,
+ struct dentry *unused, struct inode *inode,
+ const char *name, void *buffer, size_t size)
+{
+ return ext2_xattr_get(inode, EXT2_XATTR_INDEX_SECURITY, name,
+ buffer, size);
+}
+
+static int
+ext2_xattr_security_set(const struct xattr_handler *handler,
+ struct dentry *unused, struct inode *inode,
+ const char *name, const void *value,
+ size_t size, int flags)
+{
+ return ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY, name,
+ value, size, flags);
+}
+
+static int ext2_initxattrs(struct inode *inode, const struct xattr *xattr_array,
+ void *fs_info)
+{
+ const struct xattr *xattr;
+ int err = 0;
+
+ for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+ err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
+ xattr->name, xattr->value,
+ xattr->value_len, 0);
+ if (err < 0)
+ break;
+ }
+ return err;
+}
+
+int
+ext2_init_security(struct inode *inode, struct inode *dir,
+ const struct qstr *qstr)
+{
+ return security_inode_init_security(inode, dir, qstr,
+ &ext2_initxattrs, NULL);
+}
+
+const struct xattr_handler ext2_xattr_security_handler = {
+ .prefix = XATTR_SECURITY_PREFIX,
+ .get = ext2_xattr_security_get,
+ .set = ext2_xattr_security_set,
+};
diff --git a/fs/ext2/xattr_trusted.c b/fs/ext2/xattr_trusted.c
new file mode 100644
index 0000000..49add11
--- /dev/null
+++ b/fs/ext2/xattr_trusted.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/xattr_trusted.c
+ * Handler for trusted extended attributes.
+ *
+ * Copyright (C) 2003 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ */
+
+#include "ext2.h"
+#include "xattr.h"
+
+static bool
+ext2_xattr_trusted_list(struct dentry *dentry)
+{
+ return capable(CAP_SYS_ADMIN);
+}
+
+static int
+ext2_xattr_trusted_get(const struct xattr_handler *handler,
+ struct dentry *unused, struct inode *inode,
+ const char *name, void *buffer, size_t size)
+{
+ return ext2_xattr_get(inode, EXT2_XATTR_INDEX_TRUSTED, name,
+ buffer, size);
+}
+
+static int
+ext2_xattr_trusted_set(const struct xattr_handler *handler,
+ struct dentry *unused, struct inode *inode,
+ const char *name, const void *value,
+ size_t size, int flags)
+{
+ return ext2_xattr_set(inode, EXT2_XATTR_INDEX_TRUSTED, name,
+ value, size, flags);
+}
+
+const struct xattr_handler ext2_xattr_trusted_handler = {
+ .prefix = XATTR_TRUSTED_PREFIX,
+ .list = ext2_xattr_trusted_list,
+ .get = ext2_xattr_trusted_get,
+ .set = ext2_xattr_trusted_set,
+};
diff --git a/fs/ext2/xattr_user.c b/fs/ext2/xattr_user.c
new file mode 100644
index 0000000..c243a3b
--- /dev/null
+++ b/fs/ext2/xattr_user.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/xattr_user.c
+ * Handler for extended user attributes.
+ *
+ * Copyright (C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ */
+
+#include <linux/init.h>
+#include <linux/string.h>
+#include "ext2.h"
+#include "xattr.h"
+
+static bool
+ext2_xattr_user_list(struct dentry *dentry)
+{
+ return test_opt(dentry->d_sb, XATTR_USER);
+}
+
+static int
+ext2_xattr_user_get(const struct xattr_handler *handler,
+ struct dentry *unused, struct inode *inode,
+ const char *name, void *buffer, size_t size)
+{
+ if (!test_opt(inode->i_sb, XATTR_USER))
+ return -EOPNOTSUPP;
+ return ext2_xattr_get(inode, EXT2_XATTR_INDEX_USER,
+ name, buffer, size);
+}
+
+static int
+ext2_xattr_user_set(const struct xattr_handler *handler,
+ struct dentry *unused, struct inode *inode,
+ const char *name, const void *value,
+ size_t size, int flags)
+{
+ if (!test_opt(inode->i_sb, XATTR_USER))
+ return -EOPNOTSUPP;
+
+ return ext2_xattr_set(inode, EXT2_XATTR_INDEX_USER,
+ name, value, size, flags);
+}
+
+const struct xattr_handler ext2_xattr_user_handler = {
+ .prefix = XATTR_USER_PREFIX,
+ .list = ext2_xattr_user_list,
+ .get = ext2_xattr_user_get,
+ .set = ext2_xattr_user_set,
+};