v4.19.13 snapshot.
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;
+}