v4.19.13 snapshot.
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
new file mode 100644
index 0000000..72a361d
--- /dev/null
+++ b/fs/ext4/extents.c
@@ -0,0 +1,5960 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
+ * Written by Alex Tomas <alex@clusterfs.com>
+ *
+ * Architecture independence:
+ * Copyright (c) 2005, Bull S.A.
+ * Written by Pierre Peiffer <pierre.peiffer@bull.net>
+ */
+
+/*
+ * Extents support for EXT4
+ *
+ * TODO:
+ * - ext4*_error() should be used in some situations
+ * - analyze all BUG()/BUG_ON(), use -EIO where appropriate
+ * - smart tree reduction
+ */
+
+#include <linux/fs.h>
+#include <linux/time.h>
+#include <linux/jbd2.h>
+#include <linux/highuid.h>
+#include <linux/pagemap.h>
+#include <linux/quotaops.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/fiemap.h>
+#include <linux/backing-dev.h>
+#include "ext4_jbd2.h"
+#include "ext4_extents.h"
+#include "xattr.h"
+
+#include <trace/events/ext4.h>
+
+/*
+ * used by extent splitting.
+ */
+#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
+ due to ENOSPC */
+#define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */
+#define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */
+
+#define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */
+#define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
+
+static __le32 ext4_extent_block_csum(struct inode *inode,
+ struct ext4_extent_header *eh)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ __u32 csum;
+
+ csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
+ EXT4_EXTENT_TAIL_OFFSET(eh));
+ return cpu_to_le32(csum);
+}
+
+static int ext4_extent_block_csum_verify(struct inode *inode,
+ struct ext4_extent_header *eh)
+{
+ struct ext4_extent_tail *et;
+
+ if (!ext4_has_metadata_csum(inode->i_sb))
+ return 1;
+
+ et = find_ext4_extent_tail(eh);
+ if (et->et_checksum != ext4_extent_block_csum(inode, eh))
+ return 0;
+ return 1;
+}
+
+static void ext4_extent_block_csum_set(struct inode *inode,
+ struct ext4_extent_header *eh)
+{
+ struct ext4_extent_tail *et;
+
+ if (!ext4_has_metadata_csum(inode->i_sb))
+ return;
+
+ et = find_ext4_extent_tail(eh);
+ et->et_checksum = ext4_extent_block_csum(inode, eh);
+}
+
+static int ext4_split_extent(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path **ppath,
+ struct ext4_map_blocks *map,
+ int split_flag,
+ int flags);
+
+static int ext4_split_extent_at(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path **ppath,
+ ext4_lblk_t split,
+ int split_flag,
+ int flags);
+
+static int ext4_find_delayed_extent(struct inode *inode,
+ struct extent_status *newes);
+
+static int ext4_ext_truncate_extend_restart(handle_t *handle,
+ struct inode *inode,
+ int needed)
+{
+ int err;
+
+ if (!ext4_handle_valid(handle))
+ return 0;
+ if (handle->h_buffer_credits >= needed)
+ return 0;
+ /*
+ * If we need to extend the journal get a few extra blocks
+ * while we're at it for efficiency's sake.
+ */
+ needed += 3;
+ err = ext4_journal_extend(handle, needed - handle->h_buffer_credits);
+ if (err <= 0)
+ return err;
+ err = ext4_truncate_restart_trans(handle, inode, needed);
+ if (err == 0)
+ err = -EAGAIN;
+
+ return err;
+}
+
+/*
+ * could return:
+ * - EROFS
+ * - ENOMEM
+ */
+static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path)
+{
+ if (path->p_bh) {
+ /* path points to block */
+ BUFFER_TRACE(path->p_bh, "get_write_access");
+ return ext4_journal_get_write_access(handle, path->p_bh);
+ }
+ /* path points to leaf/index in inode body */
+ /* we use in-core data, no need to protect them */
+ return 0;
+}
+
+/*
+ * could return:
+ * - EROFS
+ * - ENOMEM
+ * - EIO
+ */
+int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle,
+ struct inode *inode, struct ext4_ext_path *path)
+{
+ int err;
+
+ WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
+ if (path->p_bh) {
+ ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
+ /* path points to block */
+ err = __ext4_handle_dirty_metadata(where, line, handle,
+ inode, path->p_bh);
+ } else {
+ /* path points to leaf/index in inode body */
+ err = ext4_mark_inode_dirty(handle, inode);
+ }
+ return err;
+}
+
+static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t block)
+{
+ if (path) {
+ int depth = path->p_depth;
+ struct ext4_extent *ex;
+
+ /*
+ * Try to predict block placement assuming that we are
+ * filling in a file which will eventually be
+ * non-sparse --- i.e., in the case of libbfd writing
+ * an ELF object sections out-of-order but in a way
+ * the eventually results in a contiguous object or
+ * executable file, or some database extending a table
+ * space file. However, this is actually somewhat
+ * non-ideal if we are writing a sparse file such as
+ * qemu or KVM writing a raw image file that is going
+ * to stay fairly sparse, since it will end up
+ * fragmenting the file system's free space. Maybe we
+ * should have some hueristics or some way to allow
+ * userspace to pass a hint to file system,
+ * especially if the latter case turns out to be
+ * common.
+ */
+ ex = path[depth].p_ext;
+ if (ex) {
+ ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
+ ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
+
+ if (block > ext_block)
+ return ext_pblk + (block - ext_block);
+ else
+ return ext_pblk - (ext_block - block);
+ }
+
+ /* it looks like index is empty;
+ * try to find starting block from index itself */
+ if (path[depth].p_bh)
+ return path[depth].p_bh->b_blocknr;
+ }
+
+ /* OK. use inode's group */
+ return ext4_inode_to_goal_block(inode);
+}
+
+/*
+ * Allocation for a meta data block
+ */
+static ext4_fsblk_t
+ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_extent *ex, int *err, unsigned int flags)
+{
+ ext4_fsblk_t goal, newblock;
+
+ goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
+ newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
+ NULL, err);
+ return newblock;
+}
+
+static inline int ext4_ext_space_block(struct inode *inode, int check)
+{
+ int size;
+
+ size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
+ / sizeof(struct ext4_extent);
+#ifdef AGGRESSIVE_TEST
+ if (!check && size > 6)
+ size = 6;
+#endif
+ return size;
+}
+
+static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
+{
+ int size;
+
+ size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
+ / sizeof(struct ext4_extent_idx);
+#ifdef AGGRESSIVE_TEST
+ if (!check && size > 5)
+ size = 5;
+#endif
+ return size;
+}
+
+static inline int ext4_ext_space_root(struct inode *inode, int check)
+{
+ int size;
+
+ size = sizeof(EXT4_I(inode)->i_data);
+ size -= sizeof(struct ext4_extent_header);
+ size /= sizeof(struct ext4_extent);
+#ifdef AGGRESSIVE_TEST
+ if (!check && size > 3)
+ size = 3;
+#endif
+ return size;
+}
+
+static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
+{
+ int size;
+
+ size = sizeof(EXT4_I(inode)->i_data);
+ size -= sizeof(struct ext4_extent_header);
+ size /= sizeof(struct ext4_extent_idx);
+#ifdef AGGRESSIVE_TEST
+ if (!check && size > 4)
+ size = 4;
+#endif
+ return size;
+}
+
+static inline int
+ext4_force_split_extent_at(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path **ppath, ext4_lblk_t lblk,
+ int nofail)
+{
+ struct ext4_ext_path *path = *ppath;
+ int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext);
+
+ return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ?
+ EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0,
+ EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO |
+ (nofail ? EXT4_GET_BLOCKS_METADATA_NOFAIL:0));
+}
+
+/*
+ * Calculate the number of metadata blocks needed
+ * to allocate @blocks
+ * Worse case is one block per extent
+ */
+int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ int idxs;
+
+ idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
+ / sizeof(struct ext4_extent_idx));
+
+ /*
+ * If the new delayed allocation block is contiguous with the
+ * previous da block, it can share index blocks with the
+ * previous block, so we only need to allocate a new index
+ * block every idxs leaf blocks. At ldxs**2 blocks, we need
+ * an additional index block, and at ldxs**3 blocks, yet
+ * another index blocks.
+ */
+ if (ei->i_da_metadata_calc_len &&
+ ei->i_da_metadata_calc_last_lblock+1 == lblock) {
+ int num = 0;
+
+ if ((ei->i_da_metadata_calc_len % idxs) == 0)
+ num++;
+ if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
+ num++;
+ if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
+ num++;
+ ei->i_da_metadata_calc_len = 0;
+ } else
+ ei->i_da_metadata_calc_len++;
+ ei->i_da_metadata_calc_last_lblock++;
+ return num;
+ }
+
+ /*
+ * In the worst case we need a new set of index blocks at
+ * every level of the inode's extent tree.
+ */
+ ei->i_da_metadata_calc_len = 1;
+ ei->i_da_metadata_calc_last_lblock = lblock;
+ return ext_depth(inode) + 1;
+}
+
+static int
+ext4_ext_max_entries(struct inode *inode, int depth)
+{
+ int max;
+
+ if (depth == ext_depth(inode)) {
+ if (depth == 0)
+ max = ext4_ext_space_root(inode, 1);
+ else
+ max = ext4_ext_space_root_idx(inode, 1);
+ } else {
+ if (depth == 0)
+ max = ext4_ext_space_block(inode, 1);
+ else
+ max = ext4_ext_space_block_idx(inode, 1);
+ }
+
+ return max;
+}
+
+static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
+{
+ ext4_fsblk_t block = ext4_ext_pblock(ext);
+ int len = ext4_ext_get_actual_len(ext);
+ ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
+
+ /*
+ * We allow neither:
+ * - zero length
+ * - overflow/wrap-around
+ */
+ if (lblock + len <= lblock)
+ return 0;
+ return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
+}
+
+static int ext4_valid_extent_idx(struct inode *inode,
+ struct ext4_extent_idx *ext_idx)
+{
+ ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
+
+ return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
+}
+
+static int ext4_valid_extent_entries(struct inode *inode,
+ struct ext4_extent_header *eh,
+ int depth)
+{
+ unsigned short entries;
+ if (eh->eh_entries == 0)
+ return 1;
+
+ entries = le16_to_cpu(eh->eh_entries);
+
+ if (depth == 0) {
+ /* leaf entries */
+ struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
+ struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
+ ext4_fsblk_t pblock = 0;
+ ext4_lblk_t lblock = 0;
+ ext4_lblk_t prev = 0;
+ int len = 0;
+ while (entries) {
+ if (!ext4_valid_extent(inode, ext))
+ return 0;
+
+ /* Check for overlapping extents */
+ lblock = le32_to_cpu(ext->ee_block);
+ len = ext4_ext_get_actual_len(ext);
+ if ((lblock <= prev) && prev) {
+ pblock = ext4_ext_pblock(ext);
+ es->s_last_error_block = cpu_to_le64(pblock);
+ return 0;
+ }
+ ext++;
+ entries--;
+ prev = lblock + len - 1;
+ }
+ } else {
+ struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
+ while (entries) {
+ if (!ext4_valid_extent_idx(inode, ext_idx))
+ return 0;
+ ext_idx++;
+ entries--;
+ }
+ }
+ return 1;
+}
+
+static int __ext4_ext_check(const char *function, unsigned int line,
+ struct inode *inode, struct ext4_extent_header *eh,
+ int depth, ext4_fsblk_t pblk)
+{
+ const char *error_msg;
+ int max = 0, err = -EFSCORRUPTED;
+
+ if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
+ error_msg = "invalid magic";
+ goto corrupted;
+ }
+ if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
+ error_msg = "unexpected eh_depth";
+ goto corrupted;
+ }
+ if (unlikely(eh->eh_max == 0)) {
+ error_msg = "invalid eh_max";
+ goto corrupted;
+ }
+ max = ext4_ext_max_entries(inode, depth);
+ if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
+ error_msg = "too large eh_max";
+ goto corrupted;
+ }
+ if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
+ error_msg = "invalid eh_entries";
+ goto corrupted;
+ }
+ if (!ext4_valid_extent_entries(inode, eh, depth)) {
+ error_msg = "invalid extent entries";
+ goto corrupted;
+ }
+ if (unlikely(depth > 32)) {
+ error_msg = "too large eh_depth";
+ goto corrupted;
+ }
+ /* Verify checksum on non-root extent tree nodes */
+ if (ext_depth(inode) != depth &&
+ !ext4_extent_block_csum_verify(inode, eh)) {
+ error_msg = "extent tree corrupted";
+ err = -EFSBADCRC;
+ goto corrupted;
+ }
+ return 0;
+
+corrupted:
+ ext4_error_inode(inode, function, line, 0,
+ "pblk %llu bad header/extent: %s - magic %x, "
+ "entries %u, max %u(%u), depth %u(%u)",
+ (unsigned long long) pblk, error_msg,
+ le16_to_cpu(eh->eh_magic),
+ le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
+ max, le16_to_cpu(eh->eh_depth), depth);
+ return err;
+}
+
+#define ext4_ext_check(inode, eh, depth, pblk) \
+ __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk))
+
+int ext4_ext_check_inode(struct inode *inode)
+{
+ return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
+}
+
+static struct buffer_head *
+__read_extent_tree_block(const char *function, unsigned int line,
+ struct inode *inode, ext4_fsblk_t pblk, int depth,
+ int flags)
+{
+ struct buffer_head *bh;
+ int err;
+
+ bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS);
+ if (unlikely(!bh))
+ return ERR_PTR(-ENOMEM);
+
+ if (!bh_uptodate_or_lock(bh)) {
+ trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
+ err = bh_submit_read(bh);
+ if (err < 0)
+ goto errout;
+ }
+ if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
+ return bh;
+ err = __ext4_ext_check(function, line, inode,
+ ext_block_hdr(bh), depth, pblk);
+ if (err)
+ goto errout;
+ set_buffer_verified(bh);
+ /*
+ * If this is a leaf block, cache all of its entries
+ */
+ if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
+ struct ext4_extent_header *eh = ext_block_hdr(bh);
+ struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
+ ext4_lblk_t prev = 0;
+ int i;
+
+ for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
+ unsigned int status = EXTENT_STATUS_WRITTEN;
+ ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
+ int len = ext4_ext_get_actual_len(ex);
+
+ if (prev && (prev != lblk))
+ ext4_es_cache_extent(inode, prev,
+ lblk - prev, ~0,
+ EXTENT_STATUS_HOLE);
+
+ if (ext4_ext_is_unwritten(ex))
+ status = EXTENT_STATUS_UNWRITTEN;
+ ext4_es_cache_extent(inode, lblk, len,
+ ext4_ext_pblock(ex), status);
+ prev = lblk + len;
+ }
+ }
+ return bh;
+errout:
+ put_bh(bh);
+ return ERR_PTR(err);
+
+}
+
+#define read_extent_tree_block(inode, pblk, depth, flags) \
+ __read_extent_tree_block(__func__, __LINE__, (inode), (pblk), \
+ (depth), (flags))
+
+/*
+ * This function is called to cache a file's extent information in the
+ * extent status tree
+ */
+int ext4_ext_precache(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_ext_path *path = NULL;
+ struct buffer_head *bh;
+ int i = 0, depth, ret = 0;
+
+ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ return 0; /* not an extent-mapped inode */
+
+ down_read(&ei->i_data_sem);
+ depth = ext_depth(inode);
+
+ path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
+ GFP_NOFS);
+ if (path == NULL) {
+ up_read(&ei->i_data_sem);
+ return -ENOMEM;
+ }
+
+ /* Don't cache anything if there are no external extent blocks */
+ if (depth == 0)
+ goto out;
+ path[0].p_hdr = ext_inode_hdr(inode);
+ ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
+ if (ret)
+ goto out;
+ path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
+ while (i >= 0) {
+ /*
+ * If this is a leaf block or we've reached the end of
+ * the index block, go up
+ */
+ if ((i == depth) ||
+ path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
+ brelse(path[i].p_bh);
+ path[i].p_bh = NULL;
+ i--;
+ continue;
+ }
+ bh = read_extent_tree_block(inode,
+ ext4_idx_pblock(path[i].p_idx++),
+ depth - i - 1,
+ EXT4_EX_FORCE_CACHE);
+ if (IS_ERR(bh)) {
+ ret = PTR_ERR(bh);
+ break;
+ }
+ i++;
+ path[i].p_bh = bh;
+ path[i].p_hdr = ext_block_hdr(bh);
+ path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
+ }
+ ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
+out:
+ up_read(&ei->i_data_sem);
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ return ret;
+}
+
+#ifdef EXT_DEBUG
+static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
+{
+ int k, l = path->p_depth;
+
+ ext_debug("path:");
+ for (k = 0; k <= l; k++, path++) {
+ if (path->p_idx) {
+ ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
+ ext4_idx_pblock(path->p_idx));
+ } else if (path->p_ext) {
+ ext_debug(" %d:[%d]%d:%llu ",
+ le32_to_cpu(path->p_ext->ee_block),
+ ext4_ext_is_unwritten(path->p_ext),
+ ext4_ext_get_actual_len(path->p_ext),
+ ext4_ext_pblock(path->p_ext));
+ } else
+ ext_debug(" []");
+ }
+ ext_debug("\n");
+}
+
+static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
+{
+ int depth = ext_depth(inode);
+ struct ext4_extent_header *eh;
+ struct ext4_extent *ex;
+ int i;
+
+ if (!path)
+ return;
+
+ eh = path[depth].p_hdr;
+ ex = EXT_FIRST_EXTENT(eh);
+
+ ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
+
+ for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
+ ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
+ ext4_ext_is_unwritten(ex),
+ ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
+ }
+ ext_debug("\n");
+}
+
+static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
+ ext4_fsblk_t newblock, int level)
+{
+ int depth = ext_depth(inode);
+ struct ext4_extent *ex;
+
+ if (depth != level) {
+ struct ext4_extent_idx *idx;
+ idx = path[level].p_idx;
+ while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
+ ext_debug("%d: move %d:%llu in new index %llu\n", level,
+ le32_to_cpu(idx->ei_block),
+ ext4_idx_pblock(idx),
+ newblock);
+ idx++;
+ }
+
+ return;
+ }
+
+ ex = path[depth].p_ext;
+ while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
+ ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
+ le32_to_cpu(ex->ee_block),
+ ext4_ext_pblock(ex),
+ ext4_ext_is_unwritten(ex),
+ ext4_ext_get_actual_len(ex),
+ newblock);
+ ex++;
+ }
+}
+
+#else
+#define ext4_ext_show_path(inode, path)
+#define ext4_ext_show_leaf(inode, path)
+#define ext4_ext_show_move(inode, path, newblock, level)
+#endif
+
+void ext4_ext_drop_refs(struct ext4_ext_path *path)
+{
+ int depth, i;
+
+ if (!path)
+ return;
+ depth = path->p_depth;
+ for (i = 0; i <= depth; i++, path++)
+ if (path->p_bh) {
+ brelse(path->p_bh);
+ path->p_bh = NULL;
+ }
+}
+
+/*
+ * ext4_ext_binsearch_idx:
+ * binary search for the closest index of the given block
+ * the header must be checked before calling this
+ */
+static void
+ext4_ext_binsearch_idx(struct inode *inode,
+ struct ext4_ext_path *path, ext4_lblk_t block)
+{
+ struct ext4_extent_header *eh = path->p_hdr;
+ struct ext4_extent_idx *r, *l, *m;
+
+
+ ext_debug("binsearch for %u(idx): ", block);
+
+ l = EXT_FIRST_INDEX(eh) + 1;
+ r = EXT_LAST_INDEX(eh);
+ while (l <= r) {
+ m = l + (r - l) / 2;
+ if (block < le32_to_cpu(m->ei_block))
+ r = m - 1;
+ else
+ l = m + 1;
+ ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
+ m, le32_to_cpu(m->ei_block),
+ r, le32_to_cpu(r->ei_block));
+ }
+
+ path->p_idx = l - 1;
+ ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
+ ext4_idx_pblock(path->p_idx));
+
+#ifdef CHECK_BINSEARCH
+ {
+ struct ext4_extent_idx *chix, *ix;
+ int k;
+
+ chix = ix = EXT_FIRST_INDEX(eh);
+ for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
+ if (k != 0 &&
+ le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
+ printk(KERN_DEBUG "k=%d, ix=0x%p, "
+ "first=0x%p\n", k,
+ ix, EXT_FIRST_INDEX(eh));
+ printk(KERN_DEBUG "%u <= %u\n",
+ le32_to_cpu(ix->ei_block),
+ le32_to_cpu(ix[-1].ei_block));
+ }
+ BUG_ON(k && le32_to_cpu(ix->ei_block)
+ <= le32_to_cpu(ix[-1].ei_block));
+ if (block < le32_to_cpu(ix->ei_block))
+ break;
+ chix = ix;
+ }
+ BUG_ON(chix != path->p_idx);
+ }
+#endif
+
+}
+
+/*
+ * ext4_ext_binsearch:
+ * binary search for closest extent of the given block
+ * the header must be checked before calling this
+ */
+static void
+ext4_ext_binsearch(struct inode *inode,
+ struct ext4_ext_path *path, ext4_lblk_t block)
+{
+ struct ext4_extent_header *eh = path->p_hdr;
+ struct ext4_extent *r, *l, *m;
+
+ if (eh->eh_entries == 0) {
+ /*
+ * this leaf is empty:
+ * we get such a leaf in split/add case
+ */
+ return;
+ }
+
+ ext_debug("binsearch for %u: ", block);
+
+ l = EXT_FIRST_EXTENT(eh) + 1;
+ r = EXT_LAST_EXTENT(eh);
+
+ while (l <= r) {
+ m = l + (r - l) / 2;
+ if (block < le32_to_cpu(m->ee_block))
+ r = m - 1;
+ else
+ l = m + 1;
+ ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
+ m, le32_to_cpu(m->ee_block),
+ r, le32_to_cpu(r->ee_block));
+ }
+
+ path->p_ext = l - 1;
+ ext_debug(" -> %d:%llu:[%d]%d ",
+ le32_to_cpu(path->p_ext->ee_block),
+ ext4_ext_pblock(path->p_ext),
+ ext4_ext_is_unwritten(path->p_ext),
+ ext4_ext_get_actual_len(path->p_ext));
+
+#ifdef CHECK_BINSEARCH
+ {
+ struct ext4_extent *chex, *ex;
+ int k;
+
+ chex = ex = EXT_FIRST_EXTENT(eh);
+ for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
+ BUG_ON(k && le32_to_cpu(ex->ee_block)
+ <= le32_to_cpu(ex[-1].ee_block));
+ if (block < le32_to_cpu(ex->ee_block))
+ break;
+ chex = ex;
+ }
+ BUG_ON(chex != path->p_ext);
+ }
+#endif
+
+}
+
+int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
+{
+ struct ext4_extent_header *eh;
+
+ eh = ext_inode_hdr(inode);
+ eh->eh_depth = 0;
+ eh->eh_entries = 0;
+ eh->eh_magic = EXT4_EXT_MAGIC;
+ eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
+ ext4_mark_inode_dirty(handle, inode);
+ return 0;
+}
+
+struct ext4_ext_path *
+ext4_find_extent(struct inode *inode, ext4_lblk_t block,
+ struct ext4_ext_path **orig_path, int flags)
+{
+ struct ext4_extent_header *eh;
+ struct buffer_head *bh;
+ struct ext4_ext_path *path = orig_path ? *orig_path : NULL;
+ short int depth, i, ppos = 0;
+ int ret;
+
+ eh = ext_inode_hdr(inode);
+ depth = ext_depth(inode);
+ if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) {
+ EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d",
+ depth);
+ ret = -EFSCORRUPTED;
+ goto err;
+ }
+
+ if (path) {
+ ext4_ext_drop_refs(path);
+ if (depth > path[0].p_maxdepth) {
+ kfree(path);
+ *orig_path = path = NULL;
+ }
+ }
+ if (!path) {
+ /* account possible depth increase */
+ path = kcalloc(depth + 2, sizeof(struct ext4_ext_path),
+ GFP_NOFS);
+ if (unlikely(!path))
+ return ERR_PTR(-ENOMEM);
+ path[0].p_maxdepth = depth + 1;
+ }
+ path[0].p_hdr = eh;
+ path[0].p_bh = NULL;
+
+ i = depth;
+ /* walk through the tree */
+ while (i) {
+ ext_debug("depth %d: num %d, max %d\n",
+ ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
+
+ ext4_ext_binsearch_idx(inode, path + ppos, block);
+ path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
+ path[ppos].p_depth = i;
+ path[ppos].p_ext = NULL;
+
+ bh = read_extent_tree_block(inode, path[ppos].p_block, --i,
+ flags);
+ if (IS_ERR(bh)) {
+ ret = PTR_ERR(bh);
+ goto err;
+ }
+
+ eh = ext_block_hdr(bh);
+ ppos++;
+ path[ppos].p_bh = bh;
+ path[ppos].p_hdr = eh;
+ }
+
+ path[ppos].p_depth = i;
+ path[ppos].p_ext = NULL;
+ path[ppos].p_idx = NULL;
+
+ /* find extent */
+ ext4_ext_binsearch(inode, path + ppos, block);
+ /* if not an empty leaf */
+ if (path[ppos].p_ext)
+ path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
+
+ ext4_ext_show_path(inode, path);
+
+ return path;
+
+err:
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ if (orig_path)
+ *orig_path = NULL;
+ return ERR_PTR(ret);
+}
+
+/*
+ * ext4_ext_insert_index:
+ * insert new index [@logical;@ptr] into the block at @curp;
+ * check where to insert: before @curp or after @curp
+ */
+static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *curp,
+ int logical, ext4_fsblk_t ptr)
+{
+ struct ext4_extent_idx *ix;
+ int len, err;
+
+ err = ext4_ext_get_access(handle, inode, curp);
+ if (err)
+ return err;
+
+ if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
+ EXT4_ERROR_INODE(inode,
+ "logical %d == ei_block %d!",
+ logical, le32_to_cpu(curp->p_idx->ei_block));
+ return -EFSCORRUPTED;
+ }
+
+ if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
+ >= le16_to_cpu(curp->p_hdr->eh_max))) {
+ EXT4_ERROR_INODE(inode,
+ "eh_entries %d >= eh_max %d!",
+ le16_to_cpu(curp->p_hdr->eh_entries),
+ le16_to_cpu(curp->p_hdr->eh_max));
+ return -EFSCORRUPTED;
+ }
+
+ if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
+ /* insert after */
+ ext_debug("insert new index %d after: %llu\n", logical, ptr);
+ ix = curp->p_idx + 1;
+ } else {
+ /* insert before */
+ ext_debug("insert new index %d before: %llu\n", logical, ptr);
+ ix = curp->p_idx;
+ }
+
+ len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
+ BUG_ON(len < 0);
+ if (len > 0) {
+ ext_debug("insert new index %d: "
+ "move %d indices from 0x%p to 0x%p\n",
+ logical, len, ix, ix + 1);
+ memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
+ }
+
+ if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
+ EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
+ return -EFSCORRUPTED;
+ }
+
+ ix->ei_block = cpu_to_le32(logical);
+ ext4_idx_store_pblock(ix, ptr);
+ le16_add_cpu(&curp->p_hdr->eh_entries, 1);
+
+ if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
+ EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
+ return -EFSCORRUPTED;
+ }
+
+ err = ext4_ext_dirty(handle, inode, curp);
+ ext4_std_error(inode->i_sb, err);
+
+ return err;
+}
+
+/*
+ * ext4_ext_split:
+ * inserts new subtree into the path, using free index entry
+ * at depth @at:
+ * - allocates all needed blocks (new leaf and all intermediate index blocks)
+ * - makes decision where to split
+ * - moves remaining extents and index entries (right to the split point)
+ * into the newly allocated blocks
+ * - initializes subtree
+ */
+static int ext4_ext_split(handle_t *handle, struct inode *inode,
+ unsigned int flags,
+ struct ext4_ext_path *path,
+ struct ext4_extent *newext, int at)
+{
+ struct buffer_head *bh = NULL;
+ int depth = ext_depth(inode);
+ struct ext4_extent_header *neh;
+ struct ext4_extent_idx *fidx;
+ int i = at, k, m, a;
+ ext4_fsblk_t newblock, oldblock;
+ __le32 border;
+ ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
+ int err = 0;
+
+ /* make decision: where to split? */
+ /* FIXME: now decision is simplest: at current extent */
+
+ /* if current leaf will be split, then we should use
+ * border from split point */
+ if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
+ EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
+ return -EFSCORRUPTED;
+ }
+ if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
+ border = path[depth].p_ext[1].ee_block;
+ ext_debug("leaf will be split."
+ " next leaf starts at %d\n",
+ le32_to_cpu(border));
+ } else {
+ border = newext->ee_block;
+ ext_debug("leaf will be added."
+ " next leaf starts at %d\n",
+ le32_to_cpu(border));
+ }
+
+ /*
+ * If error occurs, then we break processing
+ * and mark filesystem read-only. index won't
+ * be inserted and tree will be in consistent
+ * state. Next mount will repair buffers too.
+ */
+
+ /*
+ * Get array to track all allocated blocks.
+ * We need this to handle errors and free blocks
+ * upon them.
+ */
+ ablocks = kcalloc(depth, sizeof(ext4_fsblk_t), GFP_NOFS);
+ if (!ablocks)
+ return -ENOMEM;
+
+ /* allocate all needed blocks */
+ ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
+ for (a = 0; a < depth - at; a++) {
+ newblock = ext4_ext_new_meta_block(handle, inode, path,
+ newext, &err, flags);
+ if (newblock == 0)
+ goto cleanup;
+ ablocks[a] = newblock;
+ }
+
+ /* initialize new leaf */
+ newblock = ablocks[--a];
+ if (unlikely(newblock == 0)) {
+ EXT4_ERROR_INODE(inode, "newblock == 0!");
+ err = -EFSCORRUPTED;
+ goto cleanup;
+ }
+ bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
+ if (unlikely(!bh)) {
+ err = -ENOMEM;
+ goto cleanup;
+ }
+ lock_buffer(bh);
+
+ err = ext4_journal_get_create_access(handle, bh);
+ if (err)
+ goto cleanup;
+
+ neh = ext_block_hdr(bh);
+ neh->eh_entries = 0;
+ neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
+ neh->eh_magic = EXT4_EXT_MAGIC;
+ neh->eh_depth = 0;
+
+ /* move remainder of path[depth] to the new leaf */
+ if (unlikely(path[depth].p_hdr->eh_entries !=
+ path[depth].p_hdr->eh_max)) {
+ EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
+ path[depth].p_hdr->eh_entries,
+ path[depth].p_hdr->eh_max);
+ err = -EFSCORRUPTED;
+ goto cleanup;
+ }
+ /* start copy from next extent */
+ m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
+ ext4_ext_show_move(inode, path, newblock, depth);
+ if (m) {
+ struct ext4_extent *ex;
+ ex = EXT_FIRST_EXTENT(neh);
+ memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
+ le16_add_cpu(&neh->eh_entries, m);
+ }
+
+ ext4_extent_block_csum_set(inode, neh);
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+
+ err = ext4_handle_dirty_metadata(handle, inode, bh);
+ if (err)
+ goto cleanup;
+ brelse(bh);
+ bh = NULL;
+
+ /* correct old leaf */
+ if (m) {
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto cleanup;
+ le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ if (err)
+ goto cleanup;
+
+ }
+
+ /* create intermediate indexes */
+ k = depth - at - 1;
+ if (unlikely(k < 0)) {
+ EXT4_ERROR_INODE(inode, "k %d < 0!", k);
+ err = -EFSCORRUPTED;
+ goto cleanup;
+ }
+ if (k)
+ ext_debug("create %d intermediate indices\n", k);
+ /* insert new index into current index block */
+ /* current depth stored in i var */
+ i = depth - 1;
+ while (k--) {
+ oldblock = newblock;
+ newblock = ablocks[--a];
+ bh = sb_getblk(inode->i_sb, newblock);
+ if (unlikely(!bh)) {
+ err = -ENOMEM;
+ goto cleanup;
+ }
+ lock_buffer(bh);
+
+ err = ext4_journal_get_create_access(handle, bh);
+ if (err)
+ goto cleanup;
+
+ neh = ext_block_hdr(bh);
+ neh->eh_entries = cpu_to_le16(1);
+ neh->eh_magic = EXT4_EXT_MAGIC;
+ neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
+ neh->eh_depth = cpu_to_le16(depth - i);
+ fidx = EXT_FIRST_INDEX(neh);
+ fidx->ei_block = border;
+ ext4_idx_store_pblock(fidx, oldblock);
+
+ ext_debug("int.index at %d (block %llu): %u -> %llu\n",
+ i, newblock, le32_to_cpu(border), oldblock);
+
+ /* move remainder of path[i] to the new index block */
+ if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
+ EXT_LAST_INDEX(path[i].p_hdr))) {
+ EXT4_ERROR_INODE(inode,
+ "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
+ le32_to_cpu(path[i].p_ext->ee_block));
+ err = -EFSCORRUPTED;
+ goto cleanup;
+ }
+ /* start copy indexes */
+ m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
+ ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
+ EXT_MAX_INDEX(path[i].p_hdr));
+ ext4_ext_show_move(inode, path, newblock, i);
+ if (m) {
+ memmove(++fidx, path[i].p_idx,
+ sizeof(struct ext4_extent_idx) * m);
+ le16_add_cpu(&neh->eh_entries, m);
+ }
+ ext4_extent_block_csum_set(inode, neh);
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+
+ err = ext4_handle_dirty_metadata(handle, inode, bh);
+ if (err)
+ goto cleanup;
+ brelse(bh);
+ bh = NULL;
+
+ /* correct old index */
+ if (m) {
+ err = ext4_ext_get_access(handle, inode, path + i);
+ if (err)
+ goto cleanup;
+ le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
+ err = ext4_ext_dirty(handle, inode, path + i);
+ if (err)
+ goto cleanup;
+ }
+
+ i--;
+ }
+
+ /* insert new index */
+ err = ext4_ext_insert_index(handle, inode, path + at,
+ le32_to_cpu(border), newblock);
+
+cleanup:
+ if (bh) {
+ if (buffer_locked(bh))
+ unlock_buffer(bh);
+ brelse(bh);
+ }
+
+ if (err) {
+ /* free all allocated blocks in error case */
+ for (i = 0; i < depth; i++) {
+ if (!ablocks[i])
+ continue;
+ ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
+ EXT4_FREE_BLOCKS_METADATA);
+ }
+ }
+ kfree(ablocks);
+
+ return err;
+}
+
+/*
+ * ext4_ext_grow_indepth:
+ * implements tree growing procedure:
+ * - allocates new block
+ * - moves top-level data (index block or leaf) into the new block
+ * - initializes new top-level, creating index that points to the
+ * just created block
+ */
+static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
+ unsigned int flags)
+{
+ struct ext4_extent_header *neh;
+ struct buffer_head *bh;
+ ext4_fsblk_t newblock, goal = 0;
+ struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
+ int err = 0;
+
+ /* Try to prepend new index to old one */
+ if (ext_depth(inode))
+ goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode)));
+ if (goal > le32_to_cpu(es->s_first_data_block)) {
+ flags |= EXT4_MB_HINT_TRY_GOAL;
+ goal--;
+ } else
+ goal = ext4_inode_to_goal_block(inode);
+ newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
+ NULL, &err);
+ if (newblock == 0)
+ return err;
+
+ bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
+ if (unlikely(!bh))
+ return -ENOMEM;
+ lock_buffer(bh);
+
+ err = ext4_journal_get_create_access(handle, bh);
+ if (err) {
+ unlock_buffer(bh);
+ goto out;
+ }
+
+ /* move top-level index/leaf into new block */
+ memmove(bh->b_data, EXT4_I(inode)->i_data,
+ sizeof(EXT4_I(inode)->i_data));
+
+ /* set size of new block */
+ neh = ext_block_hdr(bh);
+ /* old root could have indexes or leaves
+ * so calculate e_max right way */
+ if (ext_depth(inode))
+ neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
+ else
+ neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
+ neh->eh_magic = EXT4_EXT_MAGIC;
+ ext4_extent_block_csum_set(inode, neh);
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+
+ err = ext4_handle_dirty_metadata(handle, inode, bh);
+ if (err)
+ goto out;
+
+ /* Update top-level index: num,max,pointer */
+ neh = ext_inode_hdr(inode);
+ neh->eh_entries = cpu_to_le16(1);
+ ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
+ if (neh->eh_depth == 0) {
+ /* Root extent block becomes index block */
+ neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
+ EXT_FIRST_INDEX(neh)->ei_block =
+ EXT_FIRST_EXTENT(neh)->ee_block;
+ }
+ ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
+ le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
+ le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
+ ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
+
+ le16_add_cpu(&neh->eh_depth, 1);
+ ext4_mark_inode_dirty(handle, inode);
+out:
+ brelse(bh);
+
+ return err;
+}
+
+/*
+ * ext4_ext_create_new_leaf:
+ * finds empty index and adds new leaf.
+ * if no free index is found, then it requests in-depth growing.
+ */
+static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
+ unsigned int mb_flags,
+ unsigned int gb_flags,
+ struct ext4_ext_path **ppath,
+ struct ext4_extent *newext)
+{
+ struct ext4_ext_path *path = *ppath;
+ struct ext4_ext_path *curp;
+ int depth, i, err = 0;
+
+repeat:
+ i = depth = ext_depth(inode);
+
+ /* walk up to the tree and look for free index entry */
+ curp = path + depth;
+ while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
+ i--;
+ curp--;
+ }
+
+ /* we use already allocated block for index block,
+ * so subsequent data blocks should be contiguous */
+ if (EXT_HAS_FREE_INDEX(curp)) {
+ /* if we found index with free entry, then use that
+ * entry: create all needed subtree and add new leaf */
+ err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
+ if (err)
+ goto out;
+
+ /* refill path */
+ path = ext4_find_extent(inode,
+ (ext4_lblk_t)le32_to_cpu(newext->ee_block),
+ ppath, gb_flags);
+ if (IS_ERR(path))
+ err = PTR_ERR(path);
+ } else {
+ /* tree is full, time to grow in depth */
+ err = ext4_ext_grow_indepth(handle, inode, mb_flags);
+ if (err)
+ goto out;
+
+ /* refill path */
+ path = ext4_find_extent(inode,
+ (ext4_lblk_t)le32_to_cpu(newext->ee_block),
+ ppath, gb_flags);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ goto out;
+ }
+
+ /*
+ * only first (depth 0 -> 1) produces free space;
+ * in all other cases we have to split the grown tree
+ */
+ depth = ext_depth(inode);
+ if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
+ /* now we need to split */
+ goto repeat;
+ }
+ }
+
+out:
+ return err;
+}
+
+/*
+ * search the closest allocated block to the left for *logical
+ * and returns it at @logical + it's physical address at @phys
+ * if *logical is the smallest allocated block, the function
+ * returns 0 at @phys
+ * return value contains 0 (success) or error code
+ */
+static int ext4_ext_search_left(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t *logical, ext4_fsblk_t *phys)
+{
+ struct ext4_extent_idx *ix;
+ struct ext4_extent *ex;
+ int depth, ee_len;
+
+ if (unlikely(path == NULL)) {
+ EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
+ return -EFSCORRUPTED;
+ }
+ depth = path->p_depth;
+ *phys = 0;
+
+ if (depth == 0 && path->p_ext == NULL)
+ return 0;
+
+ /* usually extent in the path covers blocks smaller
+ * then *logical, but it can be that extent is the
+ * first one in the file */
+
+ ex = path[depth].p_ext;
+ ee_len = ext4_ext_get_actual_len(ex);
+ if (*logical < le32_to_cpu(ex->ee_block)) {
+ if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
+ EXT4_ERROR_INODE(inode,
+ "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
+ *logical, le32_to_cpu(ex->ee_block));
+ return -EFSCORRUPTED;
+ }
+ while (--depth >= 0) {
+ ix = path[depth].p_idx;
+ if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
+ EXT4_ERROR_INODE(inode,
+ "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
+ ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
+ EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
+ le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
+ depth);
+ return -EFSCORRUPTED;
+ }
+ }
+ return 0;
+ }
+
+ if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
+ EXT4_ERROR_INODE(inode,
+ "logical %d < ee_block %d + ee_len %d!",
+ *logical, le32_to_cpu(ex->ee_block), ee_len);
+ return -EFSCORRUPTED;
+ }
+
+ *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
+ *phys = ext4_ext_pblock(ex) + ee_len - 1;
+ return 0;
+}
+
+/*
+ * search the closest allocated block to the right for *logical
+ * and returns it at @logical + it's physical address at @phys
+ * if *logical is the largest allocated block, the function
+ * returns 0 at @phys
+ * return value contains 0 (success) or error code
+ */
+static int ext4_ext_search_right(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t *logical, ext4_fsblk_t *phys,
+ struct ext4_extent **ret_ex)
+{
+ struct buffer_head *bh = NULL;
+ struct ext4_extent_header *eh;
+ struct ext4_extent_idx *ix;
+ struct ext4_extent *ex;
+ ext4_fsblk_t block;
+ int depth; /* Note, NOT eh_depth; depth from top of tree */
+ int ee_len;
+
+ if (unlikely(path == NULL)) {
+ EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
+ return -EFSCORRUPTED;
+ }
+ depth = path->p_depth;
+ *phys = 0;
+
+ if (depth == 0 && path->p_ext == NULL)
+ return 0;
+
+ /* usually extent in the path covers blocks smaller
+ * then *logical, but it can be that extent is the
+ * first one in the file */
+
+ ex = path[depth].p_ext;
+ ee_len = ext4_ext_get_actual_len(ex);
+ if (*logical < le32_to_cpu(ex->ee_block)) {
+ if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
+ EXT4_ERROR_INODE(inode,
+ "first_extent(path[%d].p_hdr) != ex",
+ depth);
+ return -EFSCORRUPTED;
+ }
+ while (--depth >= 0) {
+ ix = path[depth].p_idx;
+ if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
+ EXT4_ERROR_INODE(inode,
+ "ix != EXT_FIRST_INDEX *logical %d!",
+ *logical);
+ return -EFSCORRUPTED;
+ }
+ }
+ goto found_extent;
+ }
+
+ if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
+ EXT4_ERROR_INODE(inode,
+ "logical %d < ee_block %d + ee_len %d!",
+ *logical, le32_to_cpu(ex->ee_block), ee_len);
+ return -EFSCORRUPTED;
+ }
+
+ if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
+ /* next allocated block in this leaf */
+ ex++;
+ goto found_extent;
+ }
+
+ /* go up and search for index to the right */
+ while (--depth >= 0) {
+ ix = path[depth].p_idx;
+ if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
+ goto got_index;
+ }
+
+ /* we've gone up to the root and found no index to the right */
+ return 0;
+
+got_index:
+ /* we've found index to the right, let's
+ * follow it and find the closest allocated
+ * block to the right */
+ ix++;
+ block = ext4_idx_pblock(ix);
+ while (++depth < path->p_depth) {
+ /* subtract from p_depth to get proper eh_depth */
+ bh = read_extent_tree_block(inode, block,
+ path->p_depth - depth, 0);
+ if (IS_ERR(bh))
+ return PTR_ERR(bh);
+ eh = ext_block_hdr(bh);
+ ix = EXT_FIRST_INDEX(eh);
+ block = ext4_idx_pblock(ix);
+ put_bh(bh);
+ }
+
+ bh = read_extent_tree_block(inode, block, path->p_depth - depth, 0);
+ if (IS_ERR(bh))
+ return PTR_ERR(bh);
+ eh = ext_block_hdr(bh);
+ ex = EXT_FIRST_EXTENT(eh);
+found_extent:
+ *logical = le32_to_cpu(ex->ee_block);
+ *phys = ext4_ext_pblock(ex);
+ *ret_ex = ex;
+ if (bh)
+ put_bh(bh);
+ return 0;
+}
+
+/*
+ * ext4_ext_next_allocated_block:
+ * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
+ * NOTE: it considers block number from index entry as
+ * allocated block. Thus, index entries have to be consistent
+ * with leaves.
+ */
+ext4_lblk_t
+ext4_ext_next_allocated_block(struct ext4_ext_path *path)
+{
+ int depth;
+
+ BUG_ON(path == NULL);
+ depth = path->p_depth;
+
+ if (depth == 0 && path->p_ext == NULL)
+ return EXT_MAX_BLOCKS;
+
+ while (depth >= 0) {
+ if (depth == path->p_depth) {
+ /* leaf */
+ if (path[depth].p_ext &&
+ path[depth].p_ext !=
+ EXT_LAST_EXTENT(path[depth].p_hdr))
+ return le32_to_cpu(path[depth].p_ext[1].ee_block);
+ } else {
+ /* index */
+ if (path[depth].p_idx !=
+ EXT_LAST_INDEX(path[depth].p_hdr))
+ return le32_to_cpu(path[depth].p_idx[1].ei_block);
+ }
+ depth--;
+ }
+
+ return EXT_MAX_BLOCKS;
+}
+
+/*
+ * ext4_ext_next_leaf_block:
+ * returns first allocated block from next leaf or EXT_MAX_BLOCKS
+ */
+static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
+{
+ int depth;
+
+ BUG_ON(path == NULL);
+ depth = path->p_depth;
+
+ /* zero-tree has no leaf blocks at all */
+ if (depth == 0)
+ return EXT_MAX_BLOCKS;
+
+ /* go to index block */
+ depth--;
+
+ while (depth >= 0) {
+ if (path[depth].p_idx !=
+ EXT_LAST_INDEX(path[depth].p_hdr))
+ return (ext4_lblk_t)
+ le32_to_cpu(path[depth].p_idx[1].ei_block);
+ depth--;
+ }
+
+ return EXT_MAX_BLOCKS;
+}
+
+/*
+ * ext4_ext_correct_indexes:
+ * if leaf gets modified and modified extent is first in the leaf,
+ * then we have to correct all indexes above.
+ * TODO: do we need to correct tree in all cases?
+ */
+static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path)
+{
+ struct ext4_extent_header *eh;
+ int depth = ext_depth(inode);
+ struct ext4_extent *ex;
+ __le32 border;
+ int k, err = 0;
+
+ eh = path[depth].p_hdr;
+ ex = path[depth].p_ext;
+
+ if (unlikely(ex == NULL || eh == NULL)) {
+ EXT4_ERROR_INODE(inode,
+ "ex %p == NULL or eh %p == NULL", ex, eh);
+ return -EFSCORRUPTED;
+ }
+
+ if (depth == 0) {
+ /* there is no tree at all */
+ return 0;
+ }
+
+ if (ex != EXT_FIRST_EXTENT(eh)) {
+ /* we correct tree if first leaf got modified only */
+ return 0;
+ }
+
+ /*
+ * TODO: we need correction if border is smaller than current one
+ */
+ k = depth - 1;
+ border = path[depth].p_ext->ee_block;
+ err = ext4_ext_get_access(handle, inode, path + k);
+ if (err)
+ return err;
+ path[k].p_idx->ei_block = border;
+ err = ext4_ext_dirty(handle, inode, path + k);
+ if (err)
+ return err;
+
+ while (k--) {
+ /* change all left-side indexes */
+ if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
+ break;
+ err = ext4_ext_get_access(handle, inode, path + k);
+ if (err)
+ break;
+ path[k].p_idx->ei_block = border;
+ err = ext4_ext_dirty(handle, inode, path + k);
+ if (err)
+ break;
+ }
+
+ return err;
+}
+
+int
+ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
+ struct ext4_extent *ex2)
+{
+ unsigned short ext1_ee_len, ext2_ee_len;
+
+ if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2))
+ return 0;
+
+ ext1_ee_len = ext4_ext_get_actual_len(ex1);
+ ext2_ee_len = ext4_ext_get_actual_len(ex2);
+
+ if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
+ le32_to_cpu(ex2->ee_block))
+ return 0;
+
+ /*
+ * To allow future support for preallocated extents to be added
+ * as an RO_COMPAT feature, refuse to merge to extents if
+ * this can result in the top bit of ee_len being set.
+ */
+ if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
+ return 0;
+ /*
+ * The check for IO to unwritten extent is somewhat racy as we
+ * increment i_unwritten / set EXT4_STATE_DIO_UNWRITTEN only after
+ * dropping i_data_sem. But reserved blocks should save us in that
+ * case.
+ */
+ if (ext4_ext_is_unwritten(ex1) &&
+ (ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) ||
+ atomic_read(&EXT4_I(inode)->i_unwritten) ||
+ (ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)))
+ return 0;
+#ifdef AGGRESSIVE_TEST
+ if (ext1_ee_len >= 4)
+ return 0;
+#endif
+
+ if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
+ return 1;
+ return 0;
+}
+
+/*
+ * This function tries to merge the "ex" extent to the next extent in the tree.
+ * It always tries to merge towards right. If you want to merge towards
+ * left, pass "ex - 1" as argument instead of "ex".
+ * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
+ * 1 if they got merged.
+ */
+static int ext4_ext_try_to_merge_right(struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_extent *ex)
+{
+ struct ext4_extent_header *eh;
+ unsigned int depth, len;
+ int merge_done = 0, unwritten;
+
+ depth = ext_depth(inode);
+ BUG_ON(path[depth].p_hdr == NULL);
+ eh = path[depth].p_hdr;
+
+ while (ex < EXT_LAST_EXTENT(eh)) {
+ if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
+ break;
+ /* merge with next extent! */
+ unwritten = ext4_ext_is_unwritten(ex);
+ ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ + ext4_ext_get_actual_len(ex + 1));
+ if (unwritten)
+ ext4_ext_mark_unwritten(ex);
+
+ if (ex + 1 < EXT_LAST_EXTENT(eh)) {
+ len = (EXT_LAST_EXTENT(eh) - ex - 1)
+ * sizeof(struct ext4_extent);
+ memmove(ex + 1, ex + 2, len);
+ }
+ le16_add_cpu(&eh->eh_entries, -1);
+ merge_done = 1;
+ WARN_ON(eh->eh_entries == 0);
+ if (!eh->eh_entries)
+ EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
+ }
+
+ return merge_done;
+}
+
+/*
+ * This function does a very simple check to see if we can collapse
+ * an extent tree with a single extent tree leaf block into the inode.
+ */
+static void ext4_ext_try_to_merge_up(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path)
+{
+ size_t s;
+ unsigned max_root = ext4_ext_space_root(inode, 0);
+ ext4_fsblk_t blk;
+
+ if ((path[0].p_depth != 1) ||
+ (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
+ (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
+ return;
+
+ /*
+ * We need to modify the block allocation bitmap and the block
+ * group descriptor to release the extent tree block. If we
+ * can't get the journal credits, give up.
+ */
+ if (ext4_journal_extend(handle, 2))
+ return;
+
+ /*
+ * Copy the extent data up to the inode
+ */
+ blk = ext4_idx_pblock(path[0].p_idx);
+ s = le16_to_cpu(path[1].p_hdr->eh_entries) *
+ sizeof(struct ext4_extent_idx);
+ s += sizeof(struct ext4_extent_header);
+
+ path[1].p_maxdepth = path[0].p_maxdepth;
+ memcpy(path[0].p_hdr, path[1].p_hdr, s);
+ path[0].p_depth = 0;
+ path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
+ (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
+ path[0].p_hdr->eh_max = cpu_to_le16(max_root);
+
+ brelse(path[1].p_bh);
+ ext4_free_blocks(handle, inode, NULL, blk, 1,
+ EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
+}
+
+/*
+ * This function tries to merge the @ex extent to neighbours in the tree.
+ * return 1 if merge left else 0.
+ */
+static void ext4_ext_try_to_merge(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_extent *ex) {
+ struct ext4_extent_header *eh;
+ unsigned int depth;
+ int merge_done = 0;
+
+ depth = ext_depth(inode);
+ BUG_ON(path[depth].p_hdr == NULL);
+ eh = path[depth].p_hdr;
+
+ if (ex > EXT_FIRST_EXTENT(eh))
+ merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
+
+ if (!merge_done)
+ (void) ext4_ext_try_to_merge_right(inode, path, ex);
+
+ ext4_ext_try_to_merge_up(handle, inode, path);
+}
+
+/*
+ * check if a portion of the "newext" extent overlaps with an
+ * existing extent.
+ *
+ * If there is an overlap discovered, it updates the length of the newext
+ * such that there will be no overlap, and then returns 1.
+ * If there is no overlap found, it returns 0.
+ */
+static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
+ struct inode *inode,
+ struct ext4_extent *newext,
+ struct ext4_ext_path *path)
+{
+ ext4_lblk_t b1, b2;
+ unsigned int depth, len1;
+ unsigned int ret = 0;
+
+ b1 = le32_to_cpu(newext->ee_block);
+ len1 = ext4_ext_get_actual_len(newext);
+ depth = ext_depth(inode);
+ if (!path[depth].p_ext)
+ goto out;
+ b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
+
+ /*
+ * get the next allocated block if the extent in the path
+ * is before the requested block(s)
+ */
+ if (b2 < b1) {
+ b2 = ext4_ext_next_allocated_block(path);
+ if (b2 == EXT_MAX_BLOCKS)
+ goto out;
+ b2 = EXT4_LBLK_CMASK(sbi, b2);
+ }
+
+ /* check for wrap through zero on extent logical start block*/
+ if (b1 + len1 < b1) {
+ len1 = EXT_MAX_BLOCKS - b1;
+ newext->ee_len = cpu_to_le16(len1);
+ ret = 1;
+ }
+
+ /* check for overlap */
+ if (b1 + len1 > b2) {
+ newext->ee_len = cpu_to_le16(b2 - b1);
+ ret = 1;
+ }
+out:
+ return ret;
+}
+
+/*
+ * ext4_ext_insert_extent:
+ * tries to merge requsted extent into the existing extent or
+ * inserts requested extent as new one into the tree,
+ * creating new leaf in the no-space case.
+ */
+int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path **ppath,
+ struct ext4_extent *newext, int gb_flags)
+{
+ struct ext4_ext_path *path = *ppath;
+ struct ext4_extent_header *eh;
+ struct ext4_extent *ex, *fex;
+ struct ext4_extent *nearex; /* nearest extent */
+ struct ext4_ext_path *npath = NULL;
+ int depth, len, err;
+ ext4_lblk_t next;
+ int mb_flags = 0, unwritten;
+
+ if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
+ mb_flags |= EXT4_MB_DELALLOC_RESERVED;
+ if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
+ EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
+ return -EFSCORRUPTED;
+ }
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ eh = path[depth].p_hdr;
+ if (unlikely(path[depth].p_hdr == NULL)) {
+ EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
+ return -EFSCORRUPTED;
+ }
+
+ /* try to insert block into found extent and return */
+ if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
+
+ /*
+ * Try to see whether we should rather test the extent on
+ * right from ex, or from the left of ex. This is because
+ * ext4_find_extent() can return either extent on the
+ * left, or on the right from the searched position. This
+ * will make merging more effective.
+ */
+ if (ex < EXT_LAST_EXTENT(eh) &&
+ (le32_to_cpu(ex->ee_block) +
+ ext4_ext_get_actual_len(ex) <
+ le32_to_cpu(newext->ee_block))) {
+ ex += 1;
+ goto prepend;
+ } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
+ (le32_to_cpu(newext->ee_block) +
+ ext4_ext_get_actual_len(newext) <
+ le32_to_cpu(ex->ee_block)))
+ ex -= 1;
+
+ /* Try to append newex to the ex */
+ if (ext4_can_extents_be_merged(inode, ex, newext)) {
+ ext_debug("append [%d]%d block to %u:[%d]%d"
+ "(from %llu)\n",
+ ext4_ext_is_unwritten(newext),
+ ext4_ext_get_actual_len(newext),
+ le32_to_cpu(ex->ee_block),
+ ext4_ext_is_unwritten(ex),
+ ext4_ext_get_actual_len(ex),
+ ext4_ext_pblock(ex));
+ err = ext4_ext_get_access(handle, inode,
+ path + depth);
+ if (err)
+ return err;
+ unwritten = ext4_ext_is_unwritten(ex);
+ ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ + ext4_ext_get_actual_len(newext));
+ if (unwritten)
+ ext4_ext_mark_unwritten(ex);
+ eh = path[depth].p_hdr;
+ nearex = ex;
+ goto merge;
+ }
+
+prepend:
+ /* Try to prepend newex to the ex */
+ if (ext4_can_extents_be_merged(inode, newext, ex)) {
+ ext_debug("prepend %u[%d]%d block to %u:[%d]%d"
+ "(from %llu)\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_is_unwritten(newext),
+ ext4_ext_get_actual_len(newext),
+ le32_to_cpu(ex->ee_block),
+ ext4_ext_is_unwritten(ex),
+ ext4_ext_get_actual_len(ex),
+ ext4_ext_pblock(ex));
+ err = ext4_ext_get_access(handle, inode,
+ path + depth);
+ if (err)
+ return err;
+
+ unwritten = ext4_ext_is_unwritten(ex);
+ ex->ee_block = newext->ee_block;
+ ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
+ ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ + ext4_ext_get_actual_len(newext));
+ if (unwritten)
+ ext4_ext_mark_unwritten(ex);
+ eh = path[depth].p_hdr;
+ nearex = ex;
+ goto merge;
+ }
+ }
+
+ depth = ext_depth(inode);
+ eh = path[depth].p_hdr;
+ if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
+ goto has_space;
+
+ /* probably next leaf has space for us? */
+ fex = EXT_LAST_EXTENT(eh);
+ next = EXT_MAX_BLOCKS;
+ if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
+ next = ext4_ext_next_leaf_block(path);
+ if (next != EXT_MAX_BLOCKS) {
+ ext_debug("next leaf block - %u\n", next);
+ BUG_ON(npath != NULL);
+ npath = ext4_find_extent(inode, next, NULL, 0);
+ if (IS_ERR(npath))
+ return PTR_ERR(npath);
+ BUG_ON(npath->p_depth != path->p_depth);
+ eh = npath[depth].p_hdr;
+ if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
+ ext_debug("next leaf isn't full(%d)\n",
+ le16_to_cpu(eh->eh_entries));
+ path = npath;
+ goto has_space;
+ }
+ ext_debug("next leaf has no free space(%d,%d)\n",
+ le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
+ }
+
+ /*
+ * There is no free space in the found leaf.
+ * We're gonna add a new leaf in the tree.
+ */
+ if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
+ mb_flags |= EXT4_MB_USE_RESERVED;
+ err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
+ ppath, newext);
+ if (err)
+ goto cleanup;
+ depth = ext_depth(inode);
+ eh = path[depth].p_hdr;
+
+has_space:
+ nearex = path[depth].p_ext;
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto cleanup;
+
+ if (!nearex) {
+ /* there is no extent in this leaf, create first one */
+ ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_pblock(newext),
+ ext4_ext_is_unwritten(newext),
+ ext4_ext_get_actual_len(newext));
+ nearex = EXT_FIRST_EXTENT(eh);
+ } else {
+ if (le32_to_cpu(newext->ee_block)
+ > le32_to_cpu(nearex->ee_block)) {
+ /* Insert after */
+ ext_debug("insert %u:%llu:[%d]%d before: "
+ "nearest %p\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_pblock(newext),
+ ext4_ext_is_unwritten(newext),
+ ext4_ext_get_actual_len(newext),
+ nearex);
+ nearex++;
+ } else {
+ /* Insert before */
+ BUG_ON(newext->ee_block == nearex->ee_block);
+ ext_debug("insert %u:%llu:[%d]%d after: "
+ "nearest %p\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_pblock(newext),
+ ext4_ext_is_unwritten(newext),
+ ext4_ext_get_actual_len(newext),
+ nearex);
+ }
+ len = EXT_LAST_EXTENT(eh) - nearex + 1;
+ if (len > 0) {
+ ext_debug("insert %u:%llu:[%d]%d: "
+ "move %d extents from 0x%p to 0x%p\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_pblock(newext),
+ ext4_ext_is_unwritten(newext),
+ ext4_ext_get_actual_len(newext),
+ len, nearex, nearex + 1);
+ memmove(nearex + 1, nearex,
+ len * sizeof(struct ext4_extent));
+ }
+ }
+
+ le16_add_cpu(&eh->eh_entries, 1);
+ path[depth].p_ext = nearex;
+ nearex->ee_block = newext->ee_block;
+ ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
+ nearex->ee_len = newext->ee_len;
+
+merge:
+ /* try to merge extents */
+ if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
+ ext4_ext_try_to_merge(handle, inode, path, nearex);
+
+
+ /* time to correct all indexes above */
+ err = ext4_ext_correct_indexes(handle, inode, path);
+ if (err)
+ goto cleanup;
+
+ err = ext4_ext_dirty(handle, inode, path + path->p_depth);
+
+cleanup:
+ ext4_ext_drop_refs(npath);
+ kfree(npath);
+ return err;
+}
+
+static int ext4_fill_fiemap_extents(struct inode *inode,
+ ext4_lblk_t block, ext4_lblk_t num,
+ struct fiemap_extent_info *fieinfo)
+{
+ struct ext4_ext_path *path = NULL;
+ struct ext4_extent *ex;
+ struct extent_status es;
+ ext4_lblk_t next, next_del, start = 0, end = 0;
+ ext4_lblk_t last = block + num;
+ int exists, depth = 0, err = 0;
+ unsigned int flags = 0;
+ unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
+
+ while (block < last && block != EXT_MAX_BLOCKS) {
+ num = last - block;
+ /* find extent for this block */
+ down_read(&EXT4_I(inode)->i_data_sem);
+
+ path = ext4_find_extent(inode, block, &path, 0);
+ if (IS_ERR(path)) {
+ up_read(&EXT4_I(inode)->i_data_sem);
+ err = PTR_ERR(path);
+ path = NULL;
+ break;
+ }
+
+ depth = ext_depth(inode);
+ if (unlikely(path[depth].p_hdr == NULL)) {
+ up_read(&EXT4_I(inode)->i_data_sem);
+ EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
+ err = -EFSCORRUPTED;
+ break;
+ }
+ ex = path[depth].p_ext;
+ next = ext4_ext_next_allocated_block(path);
+
+ flags = 0;
+ exists = 0;
+ if (!ex) {
+ /* there is no extent yet, so try to allocate
+ * all requested space */
+ start = block;
+ end = block + num;
+ } else if (le32_to_cpu(ex->ee_block) > block) {
+ /* need to allocate space before found extent */
+ start = block;
+ end = le32_to_cpu(ex->ee_block);
+ if (block + num < end)
+ end = block + num;
+ } else if (block >= le32_to_cpu(ex->ee_block)
+ + ext4_ext_get_actual_len(ex)) {
+ /* need to allocate space after found extent */
+ start = block;
+ end = block + num;
+ if (end >= next)
+ end = next;
+ } else if (block >= le32_to_cpu(ex->ee_block)) {
+ /*
+ * some part of requested space is covered
+ * by found extent
+ */
+ start = block;
+ end = le32_to_cpu(ex->ee_block)
+ + ext4_ext_get_actual_len(ex);
+ if (block + num < end)
+ end = block + num;
+ exists = 1;
+ } else {
+ BUG();
+ }
+ BUG_ON(end <= start);
+
+ if (!exists) {
+ es.es_lblk = start;
+ es.es_len = end - start;
+ es.es_pblk = 0;
+ } else {
+ es.es_lblk = le32_to_cpu(ex->ee_block);
+ es.es_len = ext4_ext_get_actual_len(ex);
+ es.es_pblk = ext4_ext_pblock(ex);
+ if (ext4_ext_is_unwritten(ex))
+ flags |= FIEMAP_EXTENT_UNWRITTEN;
+ }
+
+ /*
+ * Find delayed extent and update es accordingly. We call
+ * it even in !exists case to find out whether es is the
+ * last existing extent or not.
+ */
+ next_del = ext4_find_delayed_extent(inode, &es);
+ if (!exists && next_del) {
+ exists = 1;
+ flags |= (FIEMAP_EXTENT_DELALLOC |
+ FIEMAP_EXTENT_UNKNOWN);
+ }
+ up_read(&EXT4_I(inode)->i_data_sem);
+
+ if (unlikely(es.es_len == 0)) {
+ EXT4_ERROR_INODE(inode, "es.es_len == 0");
+ err = -EFSCORRUPTED;
+ break;
+ }
+
+ /*
+ * This is possible iff next == next_del == EXT_MAX_BLOCKS.
+ * we need to check next == EXT_MAX_BLOCKS because it is
+ * possible that an extent is with unwritten and delayed
+ * status due to when an extent is delayed allocated and
+ * is allocated by fallocate status tree will track both of
+ * them in a extent.
+ *
+ * So we could return a unwritten and delayed extent, and
+ * its block is equal to 'next'.
+ */
+ if (next == next_del && next == EXT_MAX_BLOCKS) {
+ flags |= FIEMAP_EXTENT_LAST;
+ if (unlikely(next_del != EXT_MAX_BLOCKS ||
+ next != EXT_MAX_BLOCKS)) {
+ EXT4_ERROR_INODE(inode,
+ "next extent == %u, next "
+ "delalloc extent = %u",
+ next, next_del);
+ err = -EFSCORRUPTED;
+ break;
+ }
+ }
+
+ if (exists) {
+ err = fiemap_fill_next_extent(fieinfo,
+ (__u64)es.es_lblk << blksize_bits,
+ (__u64)es.es_pblk << blksize_bits,
+ (__u64)es.es_len << blksize_bits,
+ flags);
+ if (err < 0)
+ break;
+ if (err == 1) {
+ err = 0;
+ break;
+ }
+ }
+
+ block = es.es_lblk + es.es_len;
+ }
+
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ return err;
+}
+
+/*
+ * ext4_ext_determine_hole - determine hole around given block
+ * @inode: inode we lookup in
+ * @path: path in extent tree to @lblk
+ * @lblk: pointer to logical block around which we want to determine hole
+ *
+ * Determine hole length (and start if easily possible) around given logical
+ * block. We don't try too hard to find the beginning of the hole but @path
+ * actually points to extent before @lblk, we provide it.
+ *
+ * The function returns the length of a hole starting at @lblk. We update @lblk
+ * to the beginning of the hole if we managed to find it.
+ */
+static ext4_lblk_t ext4_ext_determine_hole(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t *lblk)
+{
+ int depth = ext_depth(inode);
+ struct ext4_extent *ex;
+ ext4_lblk_t len;
+
+ ex = path[depth].p_ext;
+ if (ex == NULL) {
+ /* there is no extent yet, so gap is [0;-] */
+ *lblk = 0;
+ len = EXT_MAX_BLOCKS;
+ } else if (*lblk < le32_to_cpu(ex->ee_block)) {
+ len = le32_to_cpu(ex->ee_block) - *lblk;
+ } else if (*lblk >= le32_to_cpu(ex->ee_block)
+ + ext4_ext_get_actual_len(ex)) {
+ ext4_lblk_t next;
+
+ *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
+ next = ext4_ext_next_allocated_block(path);
+ BUG_ON(next == *lblk);
+ len = next - *lblk;
+ } else {
+ BUG();
+ }
+ return len;
+}
+
+/*
+ * ext4_ext_put_gap_in_cache:
+ * calculate boundaries of the gap that the requested block fits into
+ * and cache this gap
+ */
+static void
+ext4_ext_put_gap_in_cache(struct inode *inode, ext4_lblk_t hole_start,
+ ext4_lblk_t hole_len)
+{
+ struct extent_status es;
+
+ ext4_es_find_delayed_extent_range(inode, hole_start,
+ hole_start + hole_len - 1, &es);
+ if (es.es_len) {
+ /* There's delayed extent containing lblock? */
+ if (es.es_lblk <= hole_start)
+ return;
+ hole_len = min(es.es_lblk - hole_start, hole_len);
+ }
+ ext_debug(" -> %u:%u\n", hole_start, hole_len);
+ ext4_es_insert_extent(inode, hole_start, hole_len, ~0,
+ EXTENT_STATUS_HOLE);
+}
+
+/*
+ * ext4_ext_rm_idx:
+ * removes index from the index block.
+ */
+static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path, int depth)
+{
+ int err;
+ ext4_fsblk_t leaf;
+
+ /* free index block */
+ depth--;
+ path = path + depth;
+ leaf = ext4_idx_pblock(path->p_idx);
+ if (unlikely(path->p_hdr->eh_entries == 0)) {
+ EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
+ return -EFSCORRUPTED;
+ }
+ err = ext4_ext_get_access(handle, inode, path);
+ if (err)
+ return err;
+
+ if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
+ int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
+ len *= sizeof(struct ext4_extent_idx);
+ memmove(path->p_idx, path->p_idx + 1, len);
+ }
+
+ le16_add_cpu(&path->p_hdr->eh_entries, -1);
+ err = ext4_ext_dirty(handle, inode, path);
+ if (err)
+ return err;
+ ext_debug("index is empty, remove it, free block %llu\n", leaf);
+ trace_ext4_ext_rm_idx(inode, leaf);
+
+ ext4_free_blocks(handle, inode, NULL, leaf, 1,
+ EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
+
+ while (--depth >= 0) {
+ if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
+ break;
+ path--;
+ err = ext4_ext_get_access(handle, inode, path);
+ if (err)
+ break;
+ path->p_idx->ei_block = (path+1)->p_idx->ei_block;
+ err = ext4_ext_dirty(handle, inode, path);
+ if (err)
+ break;
+ }
+ return err;
+}
+
+/*
+ * ext4_ext_calc_credits_for_single_extent:
+ * This routine returns max. credits that needed to insert an extent
+ * to the extent tree.
+ * When pass the actual path, the caller should calculate credits
+ * under i_data_sem.
+ */
+int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
+ struct ext4_ext_path *path)
+{
+ if (path) {
+ int depth = ext_depth(inode);
+ int ret = 0;
+
+ /* probably there is space in leaf? */
+ if (le16_to_cpu(path[depth].p_hdr->eh_entries)
+ < le16_to_cpu(path[depth].p_hdr->eh_max)) {
+
+ /*
+ * There are some space in the leaf tree, no
+ * need to account for leaf block credit
+ *
+ * bitmaps and block group descriptor blocks
+ * and other metadata blocks still need to be
+ * accounted.
+ */
+ /* 1 bitmap, 1 block group descriptor */
+ ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
+ return ret;
+ }
+ }
+
+ return ext4_chunk_trans_blocks(inode, nrblocks);
+}
+
+/*
+ * How many index/leaf blocks need to change/allocate to add @extents extents?
+ *
+ * If we add a single extent, then in the worse case, each tree level
+ * index/leaf need to be changed in case of the tree split.
+ *
+ * If more extents are inserted, they could cause the whole tree split more
+ * than once, but this is really rare.
+ */
+int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
+{
+ int index;
+ int depth;
+
+ /* If we are converting the inline data, only one is needed here. */
+ if (ext4_has_inline_data(inode))
+ return 1;
+
+ depth = ext_depth(inode);
+
+ if (extents <= 1)
+ index = depth * 2;
+ else
+ index = depth * 3;
+
+ return index;
+}
+
+static inline int get_default_free_blocks_flags(struct inode *inode)
+{
+ if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) ||
+ ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE))
+ return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
+ else if (ext4_should_journal_data(inode))
+ return EXT4_FREE_BLOCKS_FORGET;
+ return 0;
+}
+
+static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
+ struct ext4_extent *ex,
+ long long *partial_cluster,
+ ext4_lblk_t from, ext4_lblk_t to)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ unsigned short ee_len = ext4_ext_get_actual_len(ex);
+ ext4_fsblk_t pblk;
+ int flags = get_default_free_blocks_flags(inode);
+
+ /*
+ * For bigalloc file systems, we never free a partial cluster
+ * at the beginning of the extent. Instead, we make a note
+ * that we tried freeing the cluster, and check to see if we
+ * need to free it on a subsequent call to ext4_remove_blocks,
+ * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
+ */
+ flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
+
+ trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
+ /*
+ * If we have a partial cluster, and it's different from the
+ * cluster of the last block, we need to explicitly free the
+ * partial cluster here.
+ */
+ pblk = ext4_ext_pblock(ex) + ee_len - 1;
+ if (*partial_cluster > 0 &&
+ *partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
+ ext4_free_blocks(handle, inode, NULL,
+ EXT4_C2B(sbi, *partial_cluster),
+ sbi->s_cluster_ratio, flags);
+ *partial_cluster = 0;
+ }
+
+#ifdef EXTENTS_STATS
+ {
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ spin_lock(&sbi->s_ext_stats_lock);
+ sbi->s_ext_blocks += ee_len;
+ sbi->s_ext_extents++;
+ if (ee_len < sbi->s_ext_min)
+ sbi->s_ext_min = ee_len;
+ if (ee_len > sbi->s_ext_max)
+ sbi->s_ext_max = ee_len;
+ if (ext_depth(inode) > sbi->s_depth_max)
+ sbi->s_depth_max = ext_depth(inode);
+ spin_unlock(&sbi->s_ext_stats_lock);
+ }
+#endif
+ if (from >= le32_to_cpu(ex->ee_block)
+ && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
+ /* tail removal */
+ ext4_lblk_t num;
+ long long first_cluster;
+
+ num = le32_to_cpu(ex->ee_block) + ee_len - from;
+ pblk = ext4_ext_pblock(ex) + ee_len - num;
+ /*
+ * Usually we want to free partial cluster at the end of the
+ * extent, except for the situation when the cluster is still
+ * used by any other extent (partial_cluster is negative).
+ */
+ if (*partial_cluster < 0 &&
+ *partial_cluster == -(long long) EXT4_B2C(sbi, pblk+num-1))
+ flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
+
+ ext_debug("free last %u blocks starting %llu partial %lld\n",
+ num, pblk, *partial_cluster);
+ ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
+ /*
+ * If the block range to be freed didn't start at the
+ * beginning of a cluster, and we removed the entire
+ * extent and the cluster is not used by any other extent,
+ * save the partial cluster here, since we might need to
+ * delete if we determine that the truncate or punch hole
+ * operation has removed all of the blocks in the cluster.
+ * If that cluster is used by another extent, preserve its
+ * negative value so it isn't freed later on.
+ *
+ * If the whole extent wasn't freed, we've reached the
+ * start of the truncated/punched region and have finished
+ * removing blocks. If there's a partial cluster here it's
+ * shared with the remainder of the extent and is no longer
+ * a candidate for removal.
+ */
+ if (EXT4_PBLK_COFF(sbi, pblk) && ee_len == num) {
+ first_cluster = (long long) EXT4_B2C(sbi, pblk);
+ if (first_cluster != -*partial_cluster)
+ *partial_cluster = first_cluster;
+ } else {
+ *partial_cluster = 0;
+ }
+ } else
+ ext4_error(sbi->s_sb, "strange request: removal(2) "
+ "%u-%u from %u:%u",
+ from, to, le32_to_cpu(ex->ee_block), ee_len);
+ return 0;
+}
+
+
+/*
+ * ext4_ext_rm_leaf() Removes the extents associated with the
+ * blocks appearing between "start" and "end". Both "start"
+ * and "end" must appear in the same extent or EIO is returned.
+ *
+ * @handle: The journal handle
+ * @inode: The files inode
+ * @path: The path to the leaf
+ * @partial_cluster: The cluster which we'll have to free if all extents
+ * has been released from it. However, if this value is
+ * negative, it's a cluster just to the right of the
+ * punched region and it must not be freed.
+ * @start: The first block to remove
+ * @end: The last block to remove
+ */
+static int
+ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path,
+ long long *partial_cluster,
+ ext4_lblk_t start, ext4_lblk_t end)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ int err = 0, correct_index = 0;
+ int depth = ext_depth(inode), credits;
+ struct ext4_extent_header *eh;
+ ext4_lblk_t a, b;
+ unsigned num;
+ ext4_lblk_t ex_ee_block;
+ unsigned short ex_ee_len;
+ unsigned unwritten = 0;
+ struct ext4_extent *ex;
+ ext4_fsblk_t pblk;
+
+ /* the header must be checked already in ext4_ext_remove_space() */
+ ext_debug("truncate since %u in leaf to %u\n", start, end);
+ if (!path[depth].p_hdr)
+ path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
+ eh = path[depth].p_hdr;
+ if (unlikely(path[depth].p_hdr == NULL)) {
+ EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
+ return -EFSCORRUPTED;
+ }
+ /* find where to start removing */
+ ex = path[depth].p_ext;
+ if (!ex)
+ ex = EXT_LAST_EXTENT(eh);
+
+ ex_ee_block = le32_to_cpu(ex->ee_block);
+ ex_ee_len = ext4_ext_get_actual_len(ex);
+
+ trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
+
+ while (ex >= EXT_FIRST_EXTENT(eh) &&
+ ex_ee_block + ex_ee_len > start) {
+
+ if (ext4_ext_is_unwritten(ex))
+ unwritten = 1;
+ else
+ unwritten = 0;
+
+ ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
+ unwritten, ex_ee_len);
+ path[depth].p_ext = ex;
+
+ a = ex_ee_block > start ? ex_ee_block : start;
+ b = ex_ee_block+ex_ee_len - 1 < end ?
+ ex_ee_block+ex_ee_len - 1 : end;
+
+ ext_debug(" border %u:%u\n", a, b);
+
+ /* If this extent is beyond the end of the hole, skip it */
+ if (end < ex_ee_block) {
+ /*
+ * We're going to skip this extent and move to another,
+ * so note that its first cluster is in use to avoid
+ * freeing it when removing blocks. Eventually, the
+ * right edge of the truncated/punched region will
+ * be just to the left.
+ */
+ if (sbi->s_cluster_ratio > 1) {
+ pblk = ext4_ext_pblock(ex);
+ *partial_cluster =
+ -(long long) EXT4_B2C(sbi, pblk);
+ }
+ ex--;
+ ex_ee_block = le32_to_cpu(ex->ee_block);
+ ex_ee_len = ext4_ext_get_actual_len(ex);
+ continue;
+ } else if (b != ex_ee_block + ex_ee_len - 1) {
+ EXT4_ERROR_INODE(inode,
+ "can not handle truncate %u:%u "
+ "on extent %u:%u",
+ start, end, ex_ee_block,
+ ex_ee_block + ex_ee_len - 1);
+ err = -EFSCORRUPTED;
+ goto out;
+ } else if (a != ex_ee_block) {
+ /* remove tail of the extent */
+ num = a - ex_ee_block;
+ } else {
+ /* remove whole extent: excellent! */
+ num = 0;
+ }
+ /*
+ * 3 for leaf, sb, and inode plus 2 (bmap and group
+ * descriptor) for each block group; assume two block
+ * groups plus ex_ee_len/blocks_per_block_group for
+ * the worst case
+ */
+ credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
+ if (ex == EXT_FIRST_EXTENT(eh)) {
+ correct_index = 1;
+ credits += (ext_depth(inode)) + 1;
+ }
+ credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
+
+ err = ext4_ext_truncate_extend_restart(handle, inode, credits);
+ if (err)
+ goto out;
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
+ a, b);
+ if (err)
+ goto out;
+
+ if (num == 0)
+ /* this extent is removed; mark slot entirely unused */
+ ext4_ext_store_pblock(ex, 0);
+
+ ex->ee_len = cpu_to_le16(num);
+ /*
+ * Do not mark unwritten if all the blocks in the
+ * extent have been removed.
+ */
+ if (unwritten && num)
+ ext4_ext_mark_unwritten(ex);
+ /*
+ * If the extent was completely released,
+ * we need to remove it from the leaf
+ */
+ if (num == 0) {
+ if (end != EXT_MAX_BLOCKS - 1) {
+ /*
+ * For hole punching, we need to scoot all the
+ * extents up when an extent is removed so that
+ * we dont have blank extents in the middle
+ */
+ memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
+ sizeof(struct ext4_extent));
+
+ /* Now get rid of the one at the end */
+ memset(EXT_LAST_EXTENT(eh), 0,
+ sizeof(struct ext4_extent));
+ }
+ le16_add_cpu(&eh->eh_entries, -1);
+ }
+
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
+ ext4_ext_pblock(ex));
+ ex--;
+ ex_ee_block = le32_to_cpu(ex->ee_block);
+ ex_ee_len = ext4_ext_get_actual_len(ex);
+ }
+
+ if (correct_index && eh->eh_entries)
+ err = ext4_ext_correct_indexes(handle, inode, path);
+
+ /*
+ * If there's a partial cluster and at least one extent remains in
+ * the leaf, free the partial cluster if it isn't shared with the
+ * current extent. If it is shared with the current extent
+ * we zero partial_cluster because we've reached the start of the
+ * truncated/punched region and we're done removing blocks.
+ */
+ if (*partial_cluster > 0 && ex >= EXT_FIRST_EXTENT(eh)) {
+ pblk = ext4_ext_pblock(ex) + ex_ee_len - 1;
+ if (*partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
+ ext4_free_blocks(handle, inode, NULL,
+ EXT4_C2B(sbi, *partial_cluster),
+ sbi->s_cluster_ratio,
+ get_default_free_blocks_flags(inode));
+ }
+ *partial_cluster = 0;
+ }
+
+ /* if this leaf is free, then we should
+ * remove it from index block above */
+ if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
+ err = ext4_ext_rm_idx(handle, inode, path, depth);
+
+out:
+ return err;
+}
+
+/*
+ * ext4_ext_more_to_rm:
+ * returns 1 if current index has to be freed (even partial)
+ */
+static int
+ext4_ext_more_to_rm(struct ext4_ext_path *path)
+{
+ BUG_ON(path->p_idx == NULL);
+
+ if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
+ return 0;
+
+ /*
+ * if truncate on deeper level happened, it wasn't partial,
+ * so we have to consider current index for truncation
+ */
+ if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
+ return 0;
+ return 1;
+}
+
+int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
+ ext4_lblk_t end)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ int depth = ext_depth(inode);
+ struct ext4_ext_path *path = NULL;
+ long long partial_cluster = 0;
+ handle_t *handle;
+ int i = 0, err = 0;
+
+ ext_debug("truncate since %u to %u\n", start, end);
+
+ /* probably first extent we're gonna free will be last in block */
+ handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, depth + 1);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+again:
+ trace_ext4_ext_remove_space(inode, start, end, depth);
+
+ /*
+ * Check if we are removing extents inside the extent tree. If that
+ * is the case, we are going to punch a hole inside the extent tree
+ * so we have to check whether we need to split the extent covering
+ * the last block to remove so we can easily remove the part of it
+ * in ext4_ext_rm_leaf().
+ */
+ if (end < EXT_MAX_BLOCKS - 1) {
+ struct ext4_extent *ex;
+ ext4_lblk_t ee_block, ex_end, lblk;
+ ext4_fsblk_t pblk;
+
+ /* find extent for or closest extent to this block */
+ path = ext4_find_extent(inode, end, NULL, EXT4_EX_NOCACHE);
+ if (IS_ERR(path)) {
+ ext4_journal_stop(handle);
+ return PTR_ERR(path);
+ }
+ depth = ext_depth(inode);
+ /* Leaf not may not exist only if inode has no blocks at all */
+ ex = path[depth].p_ext;
+ if (!ex) {
+ if (depth) {
+ EXT4_ERROR_INODE(inode,
+ "path[%d].p_hdr == NULL",
+ depth);
+ err = -EFSCORRUPTED;
+ }
+ goto out;
+ }
+
+ ee_block = le32_to_cpu(ex->ee_block);
+ ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1;
+
+ /*
+ * See if the last block is inside the extent, if so split
+ * the extent at 'end' block so we can easily remove the
+ * tail of the first part of the split extent in
+ * ext4_ext_rm_leaf().
+ */
+ if (end >= ee_block && end < ex_end) {
+
+ /*
+ * If we're going to split the extent, note that
+ * the cluster containing the block after 'end' is
+ * in use to avoid freeing it when removing blocks.
+ */
+ if (sbi->s_cluster_ratio > 1) {
+ pblk = ext4_ext_pblock(ex) + end - ee_block + 2;
+ partial_cluster =
+ -(long long) EXT4_B2C(sbi, pblk);
+ }
+
+ /*
+ * Split the extent in two so that 'end' is the last
+ * block in the first new extent. Also we should not
+ * fail removing space due to ENOSPC so try to use
+ * reserved block if that happens.
+ */
+ err = ext4_force_split_extent_at(handle, inode, &path,
+ end + 1, 1);
+ if (err < 0)
+ goto out;
+
+ } else if (sbi->s_cluster_ratio > 1 && end >= ex_end) {
+ /*
+ * If there's an extent to the right its first cluster
+ * contains the immediate right boundary of the
+ * truncated/punched region. Set partial_cluster to
+ * its negative value so it won't be freed if shared
+ * with the current extent. The end < ee_block case
+ * is handled in ext4_ext_rm_leaf().
+ */
+ lblk = ex_end + 1;
+ err = ext4_ext_search_right(inode, path, &lblk, &pblk,
+ &ex);
+ if (err)
+ goto out;
+ if (pblk)
+ partial_cluster =
+ -(long long) EXT4_B2C(sbi, pblk);
+ }
+ }
+ /*
+ * We start scanning from right side, freeing all the blocks
+ * after i_size and walking into the tree depth-wise.
+ */
+ depth = ext_depth(inode);
+ if (path) {
+ int k = i = depth;
+ while (--k > 0)
+ path[k].p_block =
+ le16_to_cpu(path[k].p_hdr->eh_entries)+1;
+ } else {
+ path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
+ GFP_NOFS);
+ if (path == NULL) {
+ ext4_journal_stop(handle);
+ return -ENOMEM;
+ }
+ path[0].p_maxdepth = path[0].p_depth = depth;
+ path[0].p_hdr = ext_inode_hdr(inode);
+ i = 0;
+
+ if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
+ err = -EFSCORRUPTED;
+ goto out;
+ }
+ }
+ err = 0;
+
+ while (i >= 0 && err == 0) {
+ if (i == depth) {
+ /* this is leaf block */
+ err = ext4_ext_rm_leaf(handle, inode, path,
+ &partial_cluster, start,
+ end);
+ /* root level has p_bh == NULL, brelse() eats this */
+ brelse(path[i].p_bh);
+ path[i].p_bh = NULL;
+ i--;
+ continue;
+ }
+
+ /* this is index block */
+ if (!path[i].p_hdr) {
+ ext_debug("initialize header\n");
+ path[i].p_hdr = ext_block_hdr(path[i].p_bh);
+ }
+
+ if (!path[i].p_idx) {
+ /* this level hasn't been touched yet */
+ path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
+ path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
+ ext_debug("init index ptr: hdr 0x%p, num %d\n",
+ path[i].p_hdr,
+ le16_to_cpu(path[i].p_hdr->eh_entries));
+ } else {
+ /* we were already here, see at next index */
+ path[i].p_idx--;
+ }
+
+ ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
+ i, EXT_FIRST_INDEX(path[i].p_hdr),
+ path[i].p_idx);
+ if (ext4_ext_more_to_rm(path + i)) {
+ struct buffer_head *bh;
+ /* go to the next level */
+ ext_debug("move to level %d (block %llu)\n",
+ i + 1, ext4_idx_pblock(path[i].p_idx));
+ memset(path + i + 1, 0, sizeof(*path));
+ bh = read_extent_tree_block(inode,
+ ext4_idx_pblock(path[i].p_idx), depth - i - 1,
+ EXT4_EX_NOCACHE);
+ if (IS_ERR(bh)) {
+ /* should we reset i_size? */
+ err = PTR_ERR(bh);
+ break;
+ }
+ /* Yield here to deal with large extent trees.
+ * Should be a no-op if we did IO above. */
+ cond_resched();
+ if (WARN_ON(i + 1 > depth)) {
+ err = -EFSCORRUPTED;
+ break;
+ }
+ path[i + 1].p_bh = bh;
+
+ /* save actual number of indexes since this
+ * number is changed at the next iteration */
+ path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
+ i++;
+ } else {
+ /* we finished processing this index, go up */
+ if (path[i].p_hdr->eh_entries == 0 && i > 0) {
+ /* index is empty, remove it;
+ * handle must be already prepared by the
+ * truncatei_leaf() */
+ err = ext4_ext_rm_idx(handle, inode, path, i);
+ }
+ /* root level has p_bh == NULL, brelse() eats this */
+ brelse(path[i].p_bh);
+ path[i].p_bh = NULL;
+ i--;
+ ext_debug("return to level %d\n", i);
+ }
+ }
+
+ trace_ext4_ext_remove_space_done(inode, start, end, depth,
+ partial_cluster, path->p_hdr->eh_entries);
+
+ /*
+ * If we still have something in the partial cluster and we have removed
+ * even the first extent, then we should free the blocks in the partial
+ * cluster as well. (This code will only run when there are no leaves
+ * to the immediate left of the truncated/punched region.)
+ */
+ if (partial_cluster > 0 && err == 0) {
+ /* don't zero partial_cluster since it's not used afterwards */
+ ext4_free_blocks(handle, inode, NULL,
+ EXT4_C2B(sbi, partial_cluster),
+ sbi->s_cluster_ratio,
+ get_default_free_blocks_flags(inode));
+ }
+
+ /* TODO: flexible tree reduction should be here */
+ if (path->p_hdr->eh_entries == 0) {
+ /*
+ * truncate to zero freed all the tree,
+ * so we need to correct eh_depth
+ */
+ err = ext4_ext_get_access(handle, inode, path);
+ if (err == 0) {
+ ext_inode_hdr(inode)->eh_depth = 0;
+ ext_inode_hdr(inode)->eh_max =
+ cpu_to_le16(ext4_ext_space_root(inode, 0));
+ err = ext4_ext_dirty(handle, inode, path);
+ }
+ }
+out:
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ path = NULL;
+ if (err == -EAGAIN)
+ goto again;
+ ext4_journal_stop(handle);
+
+ return err;
+}
+
+/*
+ * called at mount time
+ */
+void ext4_ext_init(struct super_block *sb)
+{
+ /*
+ * possible initialization would be here
+ */
+
+ if (ext4_has_feature_extents(sb)) {
+#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
+ printk(KERN_INFO "EXT4-fs: file extents enabled"
+#ifdef AGGRESSIVE_TEST
+ ", aggressive tests"
+#endif
+#ifdef CHECK_BINSEARCH
+ ", check binsearch"
+#endif
+#ifdef EXTENTS_STATS
+ ", stats"
+#endif
+ "\n");
+#endif
+#ifdef EXTENTS_STATS
+ spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
+ EXT4_SB(sb)->s_ext_min = 1 << 30;
+ EXT4_SB(sb)->s_ext_max = 0;
+#endif
+ }
+}
+
+/*
+ * called at umount time
+ */
+void ext4_ext_release(struct super_block *sb)
+{
+ if (!ext4_has_feature_extents(sb))
+ return;
+
+#ifdef EXTENTS_STATS
+ if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
+ sbi->s_ext_blocks, sbi->s_ext_extents,
+ sbi->s_ext_blocks / sbi->s_ext_extents);
+ printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
+ sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
+ }
+#endif
+}
+
+static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
+{
+ ext4_lblk_t ee_block;
+ ext4_fsblk_t ee_pblock;
+ unsigned int ee_len;
+
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+ ee_pblock = ext4_ext_pblock(ex);
+
+ if (ee_len == 0)
+ return 0;
+
+ return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
+ EXTENT_STATUS_WRITTEN);
+}
+
+/* FIXME!! we need to try to merge to left or right after zero-out */
+static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
+{
+ ext4_fsblk_t ee_pblock;
+ unsigned int ee_len;
+
+ ee_len = ext4_ext_get_actual_len(ex);
+ ee_pblock = ext4_ext_pblock(ex);
+ return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock,
+ ee_len);
+}
+
+/*
+ * ext4_split_extent_at() splits an extent at given block.
+ *
+ * @handle: the journal handle
+ * @inode: the file inode
+ * @path: the path to the extent
+ * @split: the logical block where the extent is splitted.
+ * @split_flags: indicates if the extent could be zeroout if split fails, and
+ * the states(init or unwritten) of new extents.
+ * @flags: flags used to insert new extent to extent tree.
+ *
+ *
+ * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
+ * of which are deterimined by split_flag.
+ *
+ * There are two cases:
+ * a> the extent are splitted into two extent.
+ * b> split is not needed, and just mark the extent.
+ *
+ * return 0 on success.
+ */
+static int ext4_split_extent_at(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path **ppath,
+ ext4_lblk_t split,
+ int split_flag,
+ int flags)
+{
+ struct ext4_ext_path *path = *ppath;
+ ext4_fsblk_t newblock;
+ ext4_lblk_t ee_block;
+ struct ext4_extent *ex, newex, orig_ex, zero_ex;
+ struct ext4_extent *ex2 = NULL;
+ unsigned int ee_len, depth;
+ int err = 0;
+
+ BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
+ (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
+
+ ext_debug("ext4_split_extents_at: inode %lu, logical"
+ "block %llu\n", inode->i_ino, (unsigned long long)split);
+
+ ext4_ext_show_leaf(inode, path);
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+ newblock = split - ee_block + ext4_ext_pblock(ex);
+
+ BUG_ON(split < ee_block || split >= (ee_block + ee_len));
+ BUG_ON(!ext4_ext_is_unwritten(ex) &&
+ split_flag & (EXT4_EXT_MAY_ZEROOUT |
+ EXT4_EXT_MARK_UNWRIT1 |
+ EXT4_EXT_MARK_UNWRIT2));
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ if (split == ee_block) {
+ /*
+ * case b: block @split is the block that the extent begins with
+ * then we just change the state of the extent, and splitting
+ * is not needed.
+ */
+ if (split_flag & EXT4_EXT_MARK_UNWRIT2)
+ ext4_ext_mark_unwritten(ex);
+ else
+ ext4_ext_mark_initialized(ex);
+
+ if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
+ ext4_ext_try_to_merge(handle, inode, path, ex);
+
+ err = ext4_ext_dirty(handle, inode, path + path->p_depth);
+ goto out;
+ }
+
+ /* case a */
+ memcpy(&orig_ex, ex, sizeof(orig_ex));
+ ex->ee_len = cpu_to_le16(split - ee_block);
+ if (split_flag & EXT4_EXT_MARK_UNWRIT1)
+ ext4_ext_mark_unwritten(ex);
+
+ /*
+ * path may lead to new leaf, not to original leaf any more
+ * after ext4_ext_insert_extent() returns,
+ */
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ if (err)
+ goto fix_extent_len;
+
+ ex2 = &newex;
+ ex2->ee_block = cpu_to_le32(split);
+ ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
+ ext4_ext_store_pblock(ex2, newblock);
+ if (split_flag & EXT4_EXT_MARK_UNWRIT2)
+ ext4_ext_mark_unwritten(ex2);
+
+ err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags);
+ if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
+ if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
+ if (split_flag & EXT4_EXT_DATA_VALID1) {
+ err = ext4_ext_zeroout(inode, ex2);
+ zero_ex.ee_block = ex2->ee_block;
+ zero_ex.ee_len = cpu_to_le16(
+ ext4_ext_get_actual_len(ex2));
+ ext4_ext_store_pblock(&zero_ex,
+ ext4_ext_pblock(ex2));
+ } else {
+ err = ext4_ext_zeroout(inode, ex);
+ zero_ex.ee_block = ex->ee_block;
+ zero_ex.ee_len = cpu_to_le16(
+ ext4_ext_get_actual_len(ex));
+ ext4_ext_store_pblock(&zero_ex,
+ ext4_ext_pblock(ex));
+ }
+ } else {
+ err = ext4_ext_zeroout(inode, &orig_ex);
+ zero_ex.ee_block = orig_ex.ee_block;
+ zero_ex.ee_len = cpu_to_le16(
+ ext4_ext_get_actual_len(&orig_ex));
+ ext4_ext_store_pblock(&zero_ex,
+ ext4_ext_pblock(&orig_ex));
+ }
+
+ if (err)
+ goto fix_extent_len;
+ /* update the extent length and mark as initialized */
+ ex->ee_len = cpu_to_le16(ee_len);
+ ext4_ext_try_to_merge(handle, inode, path, ex);
+ err = ext4_ext_dirty(handle, inode, path + path->p_depth);
+ if (err)
+ goto fix_extent_len;
+
+ /* update extent status tree */
+ err = ext4_zeroout_es(inode, &zero_ex);
+
+ goto out;
+ } else if (err)
+ goto fix_extent_len;
+
+out:
+ ext4_ext_show_leaf(inode, path);
+ return err;
+
+fix_extent_len:
+ ex->ee_len = orig_ex.ee_len;
+ ext4_ext_dirty(handle, inode, path + path->p_depth);
+ return err;
+}
+
+/*
+ * ext4_split_extents() splits an extent and mark extent which is covered
+ * by @map as split_flags indicates
+ *
+ * It may result in splitting the extent into multiple extents (up to three)
+ * There are three possibilities:
+ * a> There is no split required
+ * b> Splits in two extents: Split is happening at either end of the extent
+ * c> Splits in three extents: Somone is splitting in middle of the extent
+ *
+ */
+static int ext4_split_extent(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path **ppath,
+ struct ext4_map_blocks *map,
+ int split_flag,
+ int flags)
+{
+ struct ext4_ext_path *path = *ppath;
+ ext4_lblk_t ee_block;
+ struct ext4_extent *ex;
+ unsigned int ee_len, depth;
+ int err = 0;
+ int unwritten;
+ int split_flag1, flags1;
+ int allocated = map->m_len;
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+ unwritten = ext4_ext_is_unwritten(ex);
+
+ if (map->m_lblk + map->m_len < ee_block + ee_len) {
+ split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
+ flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
+ if (unwritten)
+ split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
+ EXT4_EXT_MARK_UNWRIT2;
+ if (split_flag & EXT4_EXT_DATA_VALID2)
+ split_flag1 |= EXT4_EXT_DATA_VALID1;
+ err = ext4_split_extent_at(handle, inode, ppath,
+ map->m_lblk + map->m_len, split_flag1, flags1);
+ if (err)
+ goto out;
+ } else {
+ allocated = ee_len - (map->m_lblk - ee_block);
+ }
+ /*
+ * Update path is required because previous ext4_split_extent_at() may
+ * result in split of original leaf or extent zeroout.
+ */
+ path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ if (!ex) {
+ EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
+ (unsigned long) map->m_lblk);
+ return -EFSCORRUPTED;
+ }
+ unwritten = ext4_ext_is_unwritten(ex);
+ split_flag1 = 0;
+
+ if (map->m_lblk >= ee_block) {
+ split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
+ if (unwritten) {
+ split_flag1 |= EXT4_EXT_MARK_UNWRIT1;
+ split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
+ EXT4_EXT_MARK_UNWRIT2);
+ }
+ err = ext4_split_extent_at(handle, inode, ppath,
+ map->m_lblk, split_flag1, flags);
+ if (err)
+ goto out;
+ }
+
+ ext4_ext_show_leaf(inode, path);
+out:
+ return err ? err : allocated;
+}
+
+/*
+ * This function is called by ext4_ext_map_blocks() if someone tries to write
+ * to an unwritten extent. It may result in splitting the unwritten
+ * extent into multiple extents (up to three - one initialized and two
+ * unwritten).
+ * There are three possibilities:
+ * a> There is no split required: Entire extent should be initialized
+ * b> Splits in two extents: Write is happening at either end of the extent
+ * c> Splits in three extents: Somone is writing in middle of the extent
+ *
+ * Pre-conditions:
+ * - The extent pointed to by 'path' is unwritten.
+ * - The extent pointed to by 'path' contains a superset
+ * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
+ *
+ * Post-conditions on success:
+ * - the returned value is the number of blocks beyond map->l_lblk
+ * that are allocated and initialized.
+ * It is guaranteed to be >= map->m_len.
+ */
+static int ext4_ext_convert_to_initialized(handle_t *handle,
+ struct inode *inode,
+ struct ext4_map_blocks *map,
+ struct ext4_ext_path **ppath,
+ int flags)
+{
+ struct ext4_ext_path *path = *ppath;
+ struct ext4_sb_info *sbi;
+ struct ext4_extent_header *eh;
+ struct ext4_map_blocks split_map;
+ struct ext4_extent zero_ex1, zero_ex2;
+ struct ext4_extent *ex, *abut_ex;
+ ext4_lblk_t ee_block, eof_block;
+ unsigned int ee_len, depth, map_len = map->m_len;
+ int allocated = 0, max_zeroout = 0;
+ int err = 0;
+ int split_flag = EXT4_EXT_DATA_VALID2;
+
+ ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
+ "block %llu, max_blocks %u\n", inode->i_ino,
+ (unsigned long long)map->m_lblk, map_len);
+
+ sbi = EXT4_SB(inode->i_sb);
+ eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
+ inode->i_sb->s_blocksize_bits;
+ if (eof_block < map->m_lblk + map_len)
+ eof_block = map->m_lblk + map_len;
+
+ depth = ext_depth(inode);
+ eh = path[depth].p_hdr;
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+ zero_ex1.ee_len = 0;
+ zero_ex2.ee_len = 0;
+
+ trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
+
+ /* Pre-conditions */
+ BUG_ON(!ext4_ext_is_unwritten(ex));
+ BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
+
+ /*
+ * Attempt to transfer newly initialized blocks from the currently
+ * unwritten extent to its neighbor. This is much cheaper
+ * than an insertion followed by a merge as those involve costly
+ * memmove() calls. Transferring to the left is the common case in
+ * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
+ * followed by append writes.
+ *
+ * Limitations of the current logic:
+ * - L1: we do not deal with writes covering the whole extent.
+ * This would require removing the extent if the transfer
+ * is possible.
+ * - L2: we only attempt to merge with an extent stored in the
+ * same extent tree node.
+ */
+ if ((map->m_lblk == ee_block) &&
+ /* See if we can merge left */
+ (map_len < ee_len) && /*L1*/
+ (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/
+ ext4_lblk_t prev_lblk;
+ ext4_fsblk_t prev_pblk, ee_pblk;
+ unsigned int prev_len;
+
+ abut_ex = ex - 1;
+ prev_lblk = le32_to_cpu(abut_ex->ee_block);
+ prev_len = ext4_ext_get_actual_len(abut_ex);
+ prev_pblk = ext4_ext_pblock(abut_ex);
+ ee_pblk = ext4_ext_pblock(ex);
+
+ /*
+ * A transfer of blocks from 'ex' to 'abut_ex' is allowed
+ * upon those conditions:
+ * - C1: abut_ex is initialized,
+ * - C2: abut_ex is logically abutting ex,
+ * - C3: abut_ex is physically abutting ex,
+ * - C4: abut_ex can receive the additional blocks without
+ * overflowing the (initialized) length limit.
+ */
+ if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
+ ((prev_lblk + prev_len) == ee_block) && /*C2*/
+ ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
+ (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ trace_ext4_ext_convert_to_initialized_fastpath(inode,
+ map, ex, abut_ex);
+
+ /* Shift the start of ex by 'map_len' blocks */
+ ex->ee_block = cpu_to_le32(ee_block + map_len);
+ ext4_ext_store_pblock(ex, ee_pblk + map_len);
+ ex->ee_len = cpu_to_le16(ee_len - map_len);
+ ext4_ext_mark_unwritten(ex); /* Restore the flag */
+
+ /* Extend abut_ex by 'map_len' blocks */
+ abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
+
+ /* Result: number of initialized blocks past m_lblk */
+ allocated = map_len;
+ }
+ } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
+ (map_len < ee_len) && /*L1*/
+ ex < EXT_LAST_EXTENT(eh)) { /*L2*/
+ /* See if we can merge right */
+ ext4_lblk_t next_lblk;
+ ext4_fsblk_t next_pblk, ee_pblk;
+ unsigned int next_len;
+
+ abut_ex = ex + 1;
+ next_lblk = le32_to_cpu(abut_ex->ee_block);
+ next_len = ext4_ext_get_actual_len(abut_ex);
+ next_pblk = ext4_ext_pblock(abut_ex);
+ ee_pblk = ext4_ext_pblock(ex);
+
+ /*
+ * A transfer of blocks from 'ex' to 'abut_ex' is allowed
+ * upon those conditions:
+ * - C1: abut_ex is initialized,
+ * - C2: abut_ex is logically abutting ex,
+ * - C3: abut_ex is physically abutting ex,
+ * - C4: abut_ex can receive the additional blocks without
+ * overflowing the (initialized) length limit.
+ */
+ if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
+ ((map->m_lblk + map_len) == next_lblk) && /*C2*/
+ ((ee_pblk + ee_len) == next_pblk) && /*C3*/
+ (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ trace_ext4_ext_convert_to_initialized_fastpath(inode,
+ map, ex, abut_ex);
+
+ /* Shift the start of abut_ex by 'map_len' blocks */
+ abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
+ ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
+ ex->ee_len = cpu_to_le16(ee_len - map_len);
+ ext4_ext_mark_unwritten(ex); /* Restore the flag */
+
+ /* Extend abut_ex by 'map_len' blocks */
+ abut_ex->ee_len = cpu_to_le16(next_len + map_len);
+
+ /* Result: number of initialized blocks past m_lblk */
+ allocated = map_len;
+ }
+ }
+ if (allocated) {
+ /* Mark the block containing both extents as dirty */
+ ext4_ext_dirty(handle, inode, path + depth);
+
+ /* Update path to point to the right extent */
+ path[depth].p_ext = abut_ex;
+ goto out;
+ } else
+ allocated = ee_len - (map->m_lblk - ee_block);
+
+ WARN_ON(map->m_lblk < ee_block);
+ /*
+ * It is safe to convert extent to initialized via explicit
+ * zeroout only if extent is fully inside i_size or new_size.
+ */
+ split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
+
+ if (EXT4_EXT_MAY_ZEROOUT & split_flag)
+ max_zeroout = sbi->s_extent_max_zeroout_kb >>
+ (inode->i_sb->s_blocksize_bits - 10);
+
+ if (ext4_encrypted_inode(inode))
+ max_zeroout = 0;
+
+ /*
+ * five cases:
+ * 1. split the extent into three extents.
+ * 2. split the extent into two extents, zeroout the head of the first
+ * extent.
+ * 3. split the extent into two extents, zeroout the tail of the second
+ * extent.
+ * 4. split the extent into two extents with out zeroout.
+ * 5. no splitting needed, just possibly zeroout the head and / or the
+ * tail of the extent.
+ */
+ split_map.m_lblk = map->m_lblk;
+ split_map.m_len = map->m_len;
+
+ if (max_zeroout && (allocated > split_map.m_len)) {
+ if (allocated <= max_zeroout) {
+ /* case 3 or 5 */
+ zero_ex1.ee_block =
+ cpu_to_le32(split_map.m_lblk +
+ split_map.m_len);
+ zero_ex1.ee_len =
+ cpu_to_le16(allocated - split_map.m_len);
+ ext4_ext_store_pblock(&zero_ex1,
+ ext4_ext_pblock(ex) + split_map.m_lblk +
+ split_map.m_len - ee_block);
+ err = ext4_ext_zeroout(inode, &zero_ex1);
+ if (err)
+ goto out;
+ split_map.m_len = allocated;
+ }
+ if (split_map.m_lblk - ee_block + split_map.m_len <
+ max_zeroout) {
+ /* case 2 or 5 */
+ if (split_map.m_lblk != ee_block) {
+ zero_ex2.ee_block = ex->ee_block;
+ zero_ex2.ee_len = cpu_to_le16(split_map.m_lblk -
+ ee_block);
+ ext4_ext_store_pblock(&zero_ex2,
+ ext4_ext_pblock(ex));
+ err = ext4_ext_zeroout(inode, &zero_ex2);
+ if (err)
+ goto out;
+ }
+
+ split_map.m_len += split_map.m_lblk - ee_block;
+ split_map.m_lblk = ee_block;
+ allocated = map->m_len;
+ }
+ }
+
+ err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag,
+ flags);
+ if (err > 0)
+ err = 0;
+out:
+ /* If we have gotten a failure, don't zero out status tree */
+ if (!err) {
+ err = ext4_zeroout_es(inode, &zero_ex1);
+ if (!err)
+ err = ext4_zeroout_es(inode, &zero_ex2);
+ }
+ return err ? err : allocated;
+}
+
+/*
+ * This function is called by ext4_ext_map_blocks() from
+ * ext4_get_blocks_dio_write() when DIO to write
+ * to an unwritten extent.
+ *
+ * Writing to an unwritten extent may result in splitting the unwritten
+ * extent into multiple initialized/unwritten extents (up to three)
+ * There are three possibilities:
+ * a> There is no split required: Entire extent should be unwritten
+ * b> Splits in two extents: Write is happening at either end of the extent
+ * c> Splits in three extents: Somone is writing in middle of the extent
+ *
+ * This works the same way in the case of initialized -> unwritten conversion.
+ *
+ * One of more index blocks maybe needed if the extent tree grow after
+ * the unwritten extent split. To prevent ENOSPC occur at the IO
+ * complete, we need to split the unwritten extent before DIO submit
+ * the IO. The unwritten extent called at this time will be split
+ * into three unwritten extent(at most). After IO complete, the part
+ * being filled will be convert to initialized by the end_io callback function
+ * via ext4_convert_unwritten_extents().
+ *
+ * Returns the size of unwritten extent to be written on success.
+ */
+static int ext4_split_convert_extents(handle_t *handle,
+ struct inode *inode,
+ struct ext4_map_blocks *map,
+ struct ext4_ext_path **ppath,
+ int flags)
+{
+ struct ext4_ext_path *path = *ppath;
+ ext4_lblk_t eof_block;
+ ext4_lblk_t ee_block;
+ struct ext4_extent *ex;
+ unsigned int ee_len;
+ int split_flag = 0, depth;
+
+ ext_debug("%s: inode %lu, logical block %llu, max_blocks %u\n",
+ __func__, inode->i_ino,
+ (unsigned long long)map->m_lblk, map->m_len);
+
+ eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
+ inode->i_sb->s_blocksize_bits;
+ if (eof_block < map->m_lblk + map->m_len)
+ eof_block = map->m_lblk + map->m_len;
+ /*
+ * It is safe to convert extent to initialized via explicit
+ * zeroout only if extent is fully insde i_size or new_size.
+ */
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+
+ /* Convert to unwritten */
+ if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
+ split_flag |= EXT4_EXT_DATA_VALID1;
+ /* Convert to initialized */
+ } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
+ split_flag |= ee_block + ee_len <= eof_block ?
+ EXT4_EXT_MAY_ZEROOUT : 0;
+ split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
+ }
+ flags |= EXT4_GET_BLOCKS_PRE_IO;
+ return ext4_split_extent(handle, inode, ppath, map, split_flag, flags);
+}
+
+static int ext4_convert_unwritten_extents_endio(handle_t *handle,
+ struct inode *inode,
+ struct ext4_map_blocks *map,
+ struct ext4_ext_path **ppath)
+{
+ struct ext4_ext_path *path = *ppath;
+ struct ext4_extent *ex;
+ ext4_lblk_t ee_block;
+ unsigned int ee_len;
+ int depth;
+ int err = 0;
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+
+ ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
+ "block %llu, max_blocks %u\n", inode->i_ino,
+ (unsigned long long)ee_block, ee_len);
+
+ /* If extent is larger than requested it is a clear sign that we still
+ * have some extent state machine issues left. So extent_split is still
+ * required.
+ * TODO: Once all related issues will be fixed this situation should be
+ * illegal.
+ */
+ if (ee_block != map->m_lblk || ee_len > map->m_len) {
+#ifdef EXT4_DEBUG
+ ext4_warning("Inode (%ld) finished: extent logical block %llu,"
+ " len %u; IO logical block %llu, len %u",
+ inode->i_ino, (unsigned long long)ee_block, ee_len,
+ (unsigned long long)map->m_lblk, map->m_len);
+#endif
+ err = ext4_split_convert_extents(handle, inode, map, ppath,
+ EXT4_GET_BLOCKS_CONVERT);
+ if (err < 0)
+ return err;
+ path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ }
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+ /* first mark the extent as initialized */
+ ext4_ext_mark_initialized(ex);
+
+ /* note: ext4_ext_correct_indexes() isn't needed here because
+ * borders are not changed
+ */
+ ext4_ext_try_to_merge(handle, inode, path, ex);
+
+ /* Mark modified extent as dirty */
+ err = ext4_ext_dirty(handle, inode, path + path->p_depth);
+out:
+ ext4_ext_show_leaf(inode, path);
+ return err;
+}
+
+/*
+ * Handle EOFBLOCKS_FL flag, clearing it if necessary
+ */
+static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
+ ext4_lblk_t lblk,
+ struct ext4_ext_path *path,
+ unsigned int len)
+{
+ int i, depth;
+ struct ext4_extent_header *eh;
+ struct ext4_extent *last_ex;
+
+ if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
+ return 0;
+
+ depth = ext_depth(inode);
+ eh = path[depth].p_hdr;
+
+ /*
+ * We're going to remove EOFBLOCKS_FL entirely in future so we
+ * do not care for this case anymore. Simply remove the flag
+ * if there are no extents.
+ */
+ if (unlikely(!eh->eh_entries))
+ goto out;
+ last_ex = EXT_LAST_EXTENT(eh);
+ /*
+ * We should clear the EOFBLOCKS_FL flag if we are writing the
+ * last block in the last extent in the file. We test this by
+ * first checking to see if the caller to
+ * ext4_ext_get_blocks() was interested in the last block (or
+ * a block beyond the last block) in the current extent. If
+ * this turns out to be false, we can bail out from this
+ * function immediately.
+ */
+ if (lblk + len < le32_to_cpu(last_ex->ee_block) +
+ ext4_ext_get_actual_len(last_ex))
+ return 0;
+ /*
+ * If the caller does appear to be planning to write at or
+ * beyond the end of the current extent, we then test to see
+ * if the current extent is the last extent in the file, by
+ * checking to make sure it was reached via the rightmost node
+ * at each level of the tree.
+ */
+ for (i = depth-1; i >= 0; i--)
+ if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
+ return 0;
+out:
+ ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
+ return ext4_mark_inode_dirty(handle, inode);
+}
+
+/**
+ * ext4_find_delalloc_range: find delayed allocated block in the given range.
+ *
+ * Return 1 if there is a delalloc block in the range, otherwise 0.
+ */
+int ext4_find_delalloc_range(struct inode *inode,
+ ext4_lblk_t lblk_start,
+ ext4_lblk_t lblk_end)
+{
+ struct extent_status es;
+
+ ext4_es_find_delayed_extent_range(inode, lblk_start, lblk_end, &es);
+ if (es.es_len == 0)
+ return 0; /* there is no delay extent in this tree */
+ else if (es.es_lblk <= lblk_start &&
+ lblk_start < es.es_lblk + es.es_len)
+ return 1;
+ else if (lblk_start <= es.es_lblk && es.es_lblk <= lblk_end)
+ return 1;
+ else
+ return 0;
+}
+
+int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ ext4_lblk_t lblk_start, lblk_end;
+ lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
+ lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
+
+ return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
+}
+
+/**
+ * Determines how many complete clusters (out of those specified by the 'map')
+ * are under delalloc and were reserved quota for.
+ * This function is called when we are writing out the blocks that were
+ * originally written with their allocation delayed, but then the space was
+ * allocated using fallocate() before the delayed allocation could be resolved.
+ * The cases to look for are:
+ * ('=' indicated delayed allocated blocks
+ * '-' indicates non-delayed allocated blocks)
+ * (a) partial clusters towards beginning and/or end outside of allocated range
+ * are not delalloc'ed.
+ * Ex:
+ * |----c---=|====c====|====c====|===-c----|
+ * |++++++ allocated ++++++|
+ * ==> 4 complete clusters in above example
+ *
+ * (b) partial cluster (outside of allocated range) towards either end is
+ * marked for delayed allocation. In this case, we will exclude that
+ * cluster.
+ * Ex:
+ * |----====c========|========c========|
+ * |++++++ allocated ++++++|
+ * ==> 1 complete clusters in above example
+ *
+ * Ex:
+ * |================c================|
+ * |++++++ allocated ++++++|
+ * ==> 0 complete clusters in above example
+ *
+ * The ext4_da_update_reserve_space will be called only if we
+ * determine here that there were some "entire" clusters that span
+ * this 'allocated' range.
+ * In the non-bigalloc case, this function will just end up returning num_blks
+ * without ever calling ext4_find_delalloc_range.
+ */
+static unsigned int
+get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
+ unsigned int num_blks)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
+ ext4_lblk_t lblk_from, lblk_to, c_offset;
+ unsigned int allocated_clusters = 0;
+
+ alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
+ alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
+
+ /* max possible clusters for this allocation */
+ allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
+
+ trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
+
+ /* Check towards left side */
+ c_offset = EXT4_LBLK_COFF(sbi, lblk_start);
+ if (c_offset) {
+ lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start);
+ lblk_to = lblk_from + c_offset - 1;
+
+ if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
+ allocated_clusters--;
+ }
+
+ /* Now check towards right. */
+ c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks);
+ if (allocated_clusters && c_offset) {
+ lblk_from = lblk_start + num_blks;
+ lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
+
+ if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
+ allocated_clusters--;
+ }
+
+ return allocated_clusters;
+}
+
+static int
+convert_initialized_extent(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map,
+ struct ext4_ext_path **ppath,
+ unsigned int allocated)
+{
+ struct ext4_ext_path *path = *ppath;
+ struct ext4_extent *ex;
+ ext4_lblk_t ee_block;
+ unsigned int ee_len;
+ int depth;
+ int err = 0;
+
+ /*
+ * Make sure that the extent is no bigger than we support with
+ * unwritten extent
+ */
+ if (map->m_len > EXT_UNWRITTEN_MAX_LEN)
+ map->m_len = EXT_UNWRITTEN_MAX_LEN / 2;
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+
+ ext_debug("%s: inode %lu, logical"
+ "block %llu, max_blocks %u\n", __func__, inode->i_ino,
+ (unsigned long long)ee_block, ee_len);
+
+ if (ee_block != map->m_lblk || ee_len > map->m_len) {
+ err = ext4_split_convert_extents(handle, inode, map, ppath,
+ EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
+ if (err < 0)
+ return err;
+ path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ if (!ex) {
+ EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
+ (unsigned long) map->m_lblk);
+ return -EFSCORRUPTED;
+ }
+ }
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ return err;
+ /* first mark the extent as unwritten */
+ ext4_ext_mark_unwritten(ex);
+
+ /* note: ext4_ext_correct_indexes() isn't needed here because
+ * borders are not changed
+ */
+ ext4_ext_try_to_merge(handle, inode, path, ex);
+
+ /* Mark modified extent as dirty */
+ err = ext4_ext_dirty(handle, inode, path + path->p_depth);
+ if (err)
+ return err;
+ ext4_ext_show_leaf(inode, path);
+
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ err = check_eofblocks_fl(handle, inode, map->m_lblk, path, map->m_len);
+ if (err)
+ return err;
+ map->m_flags |= EXT4_MAP_UNWRITTEN;
+ if (allocated > map->m_len)
+ allocated = map->m_len;
+ map->m_len = allocated;
+ return allocated;
+}
+
+static int
+ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map,
+ struct ext4_ext_path **ppath, int flags,
+ unsigned int allocated, ext4_fsblk_t newblock)
+{
+ struct ext4_ext_path *path = *ppath;
+ int ret = 0;
+ int err = 0;
+
+ ext_debug("ext4_ext_handle_unwritten_extents: inode %lu, logical "
+ "block %llu, max_blocks %u, flags %x, allocated %u\n",
+ inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
+ flags, allocated);
+ ext4_ext_show_leaf(inode, path);
+
+ /*
+ * When writing into unwritten space, we should not fail to
+ * allocate metadata blocks for the new extent block if needed.
+ */
+ flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
+
+ trace_ext4_ext_handle_unwritten_extents(inode, map, flags,
+ allocated, newblock);
+
+ /* get_block() before submit the IO, split the extent */
+ if (flags & EXT4_GET_BLOCKS_PRE_IO) {
+ ret = ext4_split_convert_extents(handle, inode, map, ppath,
+ flags | EXT4_GET_BLOCKS_CONVERT);
+ if (ret <= 0)
+ goto out;
+ map->m_flags |= EXT4_MAP_UNWRITTEN;
+ goto out;
+ }
+ /* IO end_io complete, convert the filled extent to written */
+ if (flags & EXT4_GET_BLOCKS_CONVERT) {
+ if (flags & EXT4_GET_BLOCKS_ZERO) {
+ if (allocated > map->m_len)
+ allocated = map->m_len;
+ err = ext4_issue_zeroout(inode, map->m_lblk, newblock,
+ allocated);
+ if (err < 0)
+ goto out2;
+ }
+ ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
+ ppath);
+ if (ret >= 0) {
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ err = check_eofblocks_fl(handle, inode, map->m_lblk,
+ path, map->m_len);
+ } else
+ err = ret;
+ map->m_flags |= EXT4_MAP_MAPPED;
+ map->m_pblk = newblock;
+ if (allocated > map->m_len)
+ allocated = map->m_len;
+ map->m_len = allocated;
+ goto out2;
+ }
+ /* buffered IO case */
+ /*
+ * repeat fallocate creation request
+ * we already have an unwritten extent
+ */
+ if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
+ map->m_flags |= EXT4_MAP_UNWRITTEN;
+ goto map_out;
+ }
+
+ /* buffered READ or buffered write_begin() lookup */
+ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
+ /*
+ * We have blocks reserved already. We
+ * return allocated blocks so that delalloc
+ * won't do block reservation for us. But
+ * the buffer head will be unmapped so that
+ * a read from the block returns 0s.
+ */
+ map->m_flags |= EXT4_MAP_UNWRITTEN;
+ goto out1;
+ }
+
+ /* buffered write, writepage time, convert*/
+ ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags);
+ if (ret >= 0)
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+out:
+ if (ret <= 0) {
+ err = ret;
+ goto out2;
+ } else
+ allocated = ret;
+ map->m_flags |= EXT4_MAP_NEW;
+ /*
+ * if we allocated more blocks than requested
+ * we need to make sure we unmap the extra block
+ * allocated. The actual needed block will get
+ * unmapped later when we find the buffer_head marked
+ * new.
+ */
+ if (allocated > map->m_len) {
+ clean_bdev_aliases(inode->i_sb->s_bdev, newblock + map->m_len,
+ allocated - map->m_len);
+ allocated = map->m_len;
+ }
+ map->m_len = allocated;
+
+ /*
+ * If we have done fallocate with the offset that is already
+ * delayed allocated, we would have block reservation
+ * and quota reservation done in the delayed write path.
+ * But fallocate would have already updated quota and block
+ * count for this offset. So cancel these reservation
+ */
+ if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
+ unsigned int reserved_clusters;
+ reserved_clusters = get_reserved_cluster_alloc(inode,
+ map->m_lblk, map->m_len);
+ if (reserved_clusters)
+ ext4_da_update_reserve_space(inode,
+ reserved_clusters,
+ 0);
+ }
+
+map_out:
+ map->m_flags |= EXT4_MAP_MAPPED;
+ if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
+ err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
+ map->m_len);
+ if (err < 0)
+ goto out2;
+ }
+out1:
+ if (allocated > map->m_len)
+ allocated = map->m_len;
+ ext4_ext_show_leaf(inode, path);
+ map->m_pblk = newblock;
+ map->m_len = allocated;
+out2:
+ return err ? err : allocated;
+}
+
+/*
+ * get_implied_cluster_alloc - check to see if the requested
+ * allocation (in the map structure) overlaps with a cluster already
+ * allocated in an extent.
+ * @sb The filesystem superblock structure
+ * @map The requested lblk->pblk mapping
+ * @ex The extent structure which might contain an implied
+ * cluster allocation
+ *
+ * This function is called by ext4_ext_map_blocks() after we failed to
+ * find blocks that were already in the inode's extent tree. Hence,
+ * we know that the beginning of the requested region cannot overlap
+ * the extent from the inode's extent tree. There are three cases we
+ * want to catch. The first is this case:
+ *
+ * |--- cluster # N--|
+ * |--- extent ---| |---- requested region ---|
+ * |==========|
+ *
+ * The second case that we need to test for is this one:
+ *
+ * |--------- cluster # N ----------------|
+ * |--- requested region --| |------- extent ----|
+ * |=======================|
+ *
+ * The third case is when the requested region lies between two extents
+ * within the same cluster:
+ * |------------- cluster # N-------------|
+ * |----- ex -----| |---- ex_right ----|
+ * |------ requested region ------|
+ * |================|
+ *
+ * In each of the above cases, we need to set the map->m_pblk and
+ * map->m_len so it corresponds to the return the extent labelled as
+ * "|====|" from cluster #N, since it is already in use for data in
+ * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
+ * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
+ * as a new "allocated" block region. Otherwise, we will return 0 and
+ * ext4_ext_map_blocks() will then allocate one or more new clusters
+ * by calling ext4_mb_new_blocks().
+ */
+static int get_implied_cluster_alloc(struct super_block *sb,
+ struct ext4_map_blocks *map,
+ struct ext4_extent *ex,
+ struct ext4_ext_path *path)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
+ ext4_lblk_t ex_cluster_start, ex_cluster_end;
+ ext4_lblk_t rr_cluster_start;
+ ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
+ ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
+ unsigned short ee_len = ext4_ext_get_actual_len(ex);
+
+ /* The extent passed in that we are trying to match */
+ ex_cluster_start = EXT4_B2C(sbi, ee_block);
+ ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
+
+ /* The requested region passed into ext4_map_blocks() */
+ rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
+
+ if ((rr_cluster_start == ex_cluster_end) ||
+ (rr_cluster_start == ex_cluster_start)) {
+ if (rr_cluster_start == ex_cluster_end)
+ ee_start += ee_len - 1;
+ map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
+ map->m_len = min(map->m_len,
+ (unsigned) sbi->s_cluster_ratio - c_offset);
+ /*
+ * Check for and handle this case:
+ *
+ * |--------- cluster # N-------------|
+ * |------- extent ----|
+ * |--- requested region ---|
+ * |===========|
+ */
+
+ if (map->m_lblk < ee_block)
+ map->m_len = min(map->m_len, ee_block - map->m_lblk);
+
+ /*
+ * Check for the case where there is already another allocated
+ * block to the right of 'ex' but before the end of the cluster.
+ *
+ * |------------- cluster # N-------------|
+ * |----- ex -----| |---- ex_right ----|
+ * |------ requested region ------|
+ * |================|
+ */
+ if (map->m_lblk > ee_block) {
+ ext4_lblk_t next = ext4_ext_next_allocated_block(path);
+ map->m_len = min(map->m_len, next - map->m_lblk);
+ }
+
+ trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
+ return 1;
+ }
+
+ trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
+ return 0;
+}
+
+
+/*
+ * Block allocation/map/preallocation routine for extents based files
+ *
+ *
+ * Need to be called with
+ * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
+ * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
+ *
+ * return > 0, number of of blocks already mapped/allocated
+ * if create == 0 and these are pre-allocated blocks
+ * buffer head is unmapped
+ * otherwise blocks are mapped
+ *
+ * return = 0, if plain look up failed (blocks have not been allocated)
+ * buffer head is unmapped
+ *
+ * return < 0, error case.
+ */
+int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map, int flags)
+{
+ struct ext4_ext_path *path = NULL;
+ struct ext4_extent newex, *ex, *ex2;
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ ext4_fsblk_t newblock = 0;
+ int free_on_err = 0, err = 0, depth, ret;
+ unsigned int allocated = 0, offset = 0;
+ unsigned int allocated_clusters = 0;
+ struct ext4_allocation_request ar;
+ ext4_lblk_t cluster_offset;
+ bool map_from_cluster = false;
+
+ ext_debug("blocks %u/%u requested for inode %lu\n",
+ map->m_lblk, map->m_len, inode->i_ino);
+ trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
+
+ /* find extent for this block */
+ path = ext4_find_extent(inode, map->m_lblk, NULL, 0);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ path = NULL;
+ goto out2;
+ }
+
+ depth = ext_depth(inode);
+
+ /*
+ * consistent leaf must not be empty;
+ * this situation is possible, though, _during_ tree modification;
+ * this is why assert can't be put in ext4_find_extent()
+ */
+ if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
+ EXT4_ERROR_INODE(inode, "bad extent address "
+ "lblock: %lu, depth: %d pblock %lld",
+ (unsigned long) map->m_lblk, depth,
+ path[depth].p_block);
+ err = -EFSCORRUPTED;
+ goto out2;
+ }
+
+ ex = path[depth].p_ext;
+ if (ex) {
+ ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
+ ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
+ unsigned short ee_len;
+
+
+ /*
+ * unwritten extents are treated as holes, except that
+ * we split out initialized portions during a write.
+ */
+ ee_len = ext4_ext_get_actual_len(ex);
+
+ trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
+
+ /* if found extent covers block, simply return it */
+ if (in_range(map->m_lblk, ee_block, ee_len)) {
+ newblock = map->m_lblk - ee_block + ee_start;
+ /* number of remaining blocks in the extent */
+ allocated = ee_len - (map->m_lblk - ee_block);
+ ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
+ ee_block, ee_len, newblock);
+
+ /*
+ * If the extent is initialized check whether the
+ * caller wants to convert it to unwritten.
+ */
+ if ((!ext4_ext_is_unwritten(ex)) &&
+ (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
+ allocated = convert_initialized_extent(
+ handle, inode, map, &path,
+ allocated);
+ goto out2;
+ } else if (!ext4_ext_is_unwritten(ex))
+ goto out;
+
+ ret = ext4_ext_handle_unwritten_extents(
+ handle, inode, map, &path, flags,
+ allocated, newblock);
+ if (ret < 0)
+ err = ret;
+ else
+ allocated = ret;
+ goto out2;
+ }
+ }
+
+ /*
+ * requested block isn't allocated yet;
+ * we couldn't try to create block if create flag is zero
+ */
+ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
+ ext4_lblk_t hole_start, hole_len;
+
+ hole_start = map->m_lblk;
+ hole_len = ext4_ext_determine_hole(inode, path, &hole_start);
+ /*
+ * put just found gap into cache to speed up
+ * subsequent requests
+ */
+ ext4_ext_put_gap_in_cache(inode, hole_start, hole_len);
+
+ /* Update hole_len to reflect hole size after map->m_lblk */
+ if (hole_start != map->m_lblk)
+ hole_len -= map->m_lblk - hole_start;
+ map->m_pblk = 0;
+ map->m_len = min_t(unsigned int, map->m_len, hole_len);
+
+ goto out2;
+ }
+
+ /*
+ * Okay, we need to do block allocation.
+ */
+ newex.ee_block = cpu_to_le32(map->m_lblk);
+ cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
+
+ /*
+ * If we are doing bigalloc, check to see if the extent returned
+ * by ext4_find_extent() implies a cluster we can use.
+ */
+ if (cluster_offset && ex &&
+ get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
+ ar.len = allocated = map->m_len;
+ newblock = map->m_pblk;
+ map_from_cluster = true;
+ goto got_allocated_blocks;
+ }
+
+ /* find neighbour allocated blocks */
+ ar.lleft = map->m_lblk;
+ err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
+ if (err)
+ goto out2;
+ ar.lright = map->m_lblk;
+ ex2 = NULL;
+ err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
+ if (err)
+ goto out2;
+
+ /* Check if the extent after searching to the right implies a
+ * cluster we can use. */
+ if ((sbi->s_cluster_ratio > 1) && ex2 &&
+ get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
+ ar.len = allocated = map->m_len;
+ newblock = map->m_pblk;
+ map_from_cluster = true;
+ goto got_allocated_blocks;
+ }
+
+ /*
+ * See if request is beyond maximum number of blocks we can have in
+ * a single extent. For an initialized extent this limit is
+ * EXT_INIT_MAX_LEN and for an unwritten extent this limit is
+ * EXT_UNWRITTEN_MAX_LEN.
+ */
+ if (map->m_len > EXT_INIT_MAX_LEN &&
+ !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
+ map->m_len = EXT_INIT_MAX_LEN;
+ else if (map->m_len > EXT_UNWRITTEN_MAX_LEN &&
+ (flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
+ map->m_len = EXT_UNWRITTEN_MAX_LEN;
+
+ /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
+ newex.ee_len = cpu_to_le16(map->m_len);
+ err = ext4_ext_check_overlap(sbi, inode, &newex, path);
+ if (err)
+ allocated = ext4_ext_get_actual_len(&newex);
+ else
+ allocated = map->m_len;
+
+ /* allocate new block */
+ ar.inode = inode;
+ ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
+ ar.logical = map->m_lblk;
+ /*
+ * We calculate the offset from the beginning of the cluster
+ * for the logical block number, since when we allocate a
+ * physical cluster, the physical block should start at the
+ * same offset from the beginning of the cluster. This is
+ * needed so that future calls to get_implied_cluster_alloc()
+ * work correctly.
+ */
+ offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
+ ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
+ ar.goal -= offset;
+ ar.logical -= offset;
+ if (S_ISREG(inode->i_mode))
+ ar.flags = EXT4_MB_HINT_DATA;
+ else
+ /* disable in-core preallocation for non-regular files */
+ ar.flags = 0;
+ if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
+ ar.flags |= EXT4_MB_HINT_NOPREALLOC;
+ if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
+ ar.flags |= EXT4_MB_DELALLOC_RESERVED;
+ if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
+ ar.flags |= EXT4_MB_USE_RESERVED;
+ newblock = ext4_mb_new_blocks(handle, &ar, &err);
+ if (!newblock)
+ goto out2;
+ ext_debug("allocate new block: goal %llu, found %llu/%u\n",
+ ar.goal, newblock, allocated);
+ free_on_err = 1;
+ allocated_clusters = ar.len;
+ ar.len = EXT4_C2B(sbi, ar.len) - offset;
+ if (ar.len > allocated)
+ ar.len = allocated;
+
+got_allocated_blocks:
+ /* try to insert new extent into found leaf and return */
+ ext4_ext_store_pblock(&newex, newblock + offset);
+ newex.ee_len = cpu_to_le16(ar.len);
+ /* Mark unwritten */
+ if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT){
+ ext4_ext_mark_unwritten(&newex);
+ map->m_flags |= EXT4_MAP_UNWRITTEN;
+ }
+
+ err = 0;
+ if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
+ err = check_eofblocks_fl(handle, inode, map->m_lblk,
+ path, ar.len);
+ if (!err)
+ err = ext4_ext_insert_extent(handle, inode, &path,
+ &newex, flags);
+
+ if (err && free_on_err) {
+ int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
+ EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
+ /* free data blocks we just allocated */
+ /* not a good idea to call discard here directly,
+ * but otherwise we'd need to call it every free() */
+ ext4_discard_preallocations(inode);
+ ext4_free_blocks(handle, inode, NULL, newblock,
+ EXT4_C2B(sbi, allocated_clusters), fb_flags);
+ goto out2;
+ }
+
+ /* previous routine could use block we allocated */
+ newblock = ext4_ext_pblock(&newex);
+ allocated = ext4_ext_get_actual_len(&newex);
+ if (allocated > map->m_len)
+ allocated = map->m_len;
+ map->m_flags |= EXT4_MAP_NEW;
+
+ /*
+ * Update reserved blocks/metadata blocks after successful
+ * block allocation which had been deferred till now.
+ */
+ if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
+ unsigned int reserved_clusters;
+ /*
+ * Check how many clusters we had reserved this allocated range
+ */
+ reserved_clusters = get_reserved_cluster_alloc(inode,
+ map->m_lblk, allocated);
+ if (!map_from_cluster) {
+ BUG_ON(allocated_clusters < reserved_clusters);
+ if (reserved_clusters < allocated_clusters) {
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ int reservation = allocated_clusters -
+ reserved_clusters;
+ /*
+ * It seems we claimed few clusters outside of
+ * the range of this allocation. We should give
+ * it back to the reservation pool. This can
+ * happen in the following case:
+ *
+ * * Suppose s_cluster_ratio is 4 (i.e., each
+ * cluster has 4 blocks. Thus, the clusters
+ * are [0-3],[4-7],[8-11]...
+ * * First comes delayed allocation write for
+ * logical blocks 10 & 11. Since there were no
+ * previous delayed allocated blocks in the
+ * range [8-11], we would reserve 1 cluster
+ * for this write.
+ * * Next comes write for logical blocks 3 to 8.
+ * In this case, we will reserve 2 clusters
+ * (for [0-3] and [4-7]; and not for [8-11] as
+ * that range has a delayed allocated blocks.
+ * Thus total reserved clusters now becomes 3.
+ * * Now, during the delayed allocation writeout
+ * time, we will first write blocks [3-8] and
+ * allocate 3 clusters for writing these
+ * blocks. Also, we would claim all these
+ * three clusters above.
+ * * Now when we come here to writeout the
+ * blocks [10-11], we would expect to claim
+ * the reservation of 1 cluster we had made
+ * (and we would claim it since there are no
+ * more delayed allocated blocks in the range
+ * [8-11]. But our reserved cluster count had
+ * already gone to 0.
+ *
+ * Thus, at the step 4 above when we determine
+ * that there are still some unwritten delayed
+ * allocated blocks outside of our current
+ * block range, we should increment the
+ * reserved clusters count so that when the
+ * remaining blocks finally gets written, we
+ * could claim them.
+ */
+ dquot_reserve_block(inode,
+ EXT4_C2B(sbi, reservation));
+ spin_lock(&ei->i_block_reservation_lock);
+ ei->i_reserved_data_blocks += reservation;
+ spin_unlock(&ei->i_block_reservation_lock);
+ }
+ /*
+ * We will claim quota for all newly allocated blocks.
+ * We're updating the reserved space *after* the
+ * correction above so we do not accidentally free
+ * all the metadata reservation because we might
+ * actually need it later on.
+ */
+ ext4_da_update_reserve_space(inode, allocated_clusters,
+ 1);
+ }
+ }
+
+ /*
+ * Cache the extent and update transaction to commit on fdatasync only
+ * when it is _not_ an unwritten extent.
+ */
+ if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0)
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ else
+ ext4_update_inode_fsync_trans(handle, inode, 0);
+out:
+ if (allocated > map->m_len)
+ allocated = map->m_len;
+ ext4_ext_show_leaf(inode, path);
+ map->m_flags |= EXT4_MAP_MAPPED;
+ map->m_pblk = newblock;
+ map->m_len = allocated;
+out2:
+ ext4_ext_drop_refs(path);
+ kfree(path);
+
+ trace_ext4_ext_map_blocks_exit(inode, flags, map,
+ err ? err : allocated);
+ return err ? err : allocated;
+}
+
+int ext4_ext_truncate(handle_t *handle, struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ ext4_lblk_t last_block;
+ int err = 0;
+
+ /*
+ * TODO: optimization is possible here.
+ * Probably we need not scan at all,
+ * because page truncation is enough.
+ */
+
+ /* we have to know where to truncate from in crash case */
+ EXT4_I(inode)->i_disksize = inode->i_size;
+ err = ext4_mark_inode_dirty(handle, inode);
+ if (err)
+ return err;
+
+ last_block = (inode->i_size + sb->s_blocksize - 1)
+ >> EXT4_BLOCK_SIZE_BITS(sb);
+retry:
+ err = ext4_es_remove_extent(inode, last_block,
+ EXT_MAX_BLOCKS - last_block);
+ if (err == -ENOMEM) {
+ cond_resched();
+ congestion_wait(BLK_RW_ASYNC, HZ/50);
+ goto retry;
+ }
+ if (err)
+ return err;
+ return ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
+}
+
+static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
+ ext4_lblk_t len, loff_t new_size,
+ int flags)
+{
+ struct inode *inode = file_inode(file);
+ handle_t *handle;
+ int ret = 0;
+ int ret2 = 0;
+ int retries = 0;
+ int depth = 0;
+ struct ext4_map_blocks map;
+ unsigned int credits;
+ loff_t epos;
+
+ BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS));
+ map.m_lblk = offset;
+ map.m_len = len;
+ /*
+ * Don't normalize the request if it can fit in one extent so
+ * that it doesn't get unnecessarily split into multiple
+ * extents.
+ */
+ if (len <= EXT_UNWRITTEN_MAX_LEN)
+ flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
+
+ /*
+ * credits to insert 1 extent into extent tree
+ */
+ credits = ext4_chunk_trans_blocks(inode, len);
+ depth = ext_depth(inode);
+
+retry:
+ while (ret >= 0 && len) {
+ /*
+ * Recalculate credits when extent tree depth changes.
+ */
+ if (depth != ext_depth(inode)) {
+ credits = ext4_chunk_trans_blocks(inode, len);
+ depth = ext_depth(inode);
+ }
+
+ handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
+ credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ break;
+ }
+ ret = ext4_map_blocks(handle, inode, &map, flags);
+ if (ret <= 0) {
+ ext4_debug("inode #%lu: block %u: len %u: "
+ "ext4_ext_map_blocks returned %d",
+ inode->i_ino, map.m_lblk,
+ map.m_len, ret);
+ ext4_mark_inode_dirty(handle, inode);
+ ret2 = ext4_journal_stop(handle);
+ break;
+ }
+ map.m_lblk += ret;
+ map.m_len = len = len - ret;
+ epos = (loff_t)map.m_lblk << inode->i_blkbits;
+ inode->i_ctime = current_time(inode);
+ if (new_size) {
+ if (epos > new_size)
+ epos = new_size;
+ if (ext4_update_inode_size(inode, epos) & 0x1)
+ inode->i_mtime = inode->i_ctime;
+ } else {
+ if (epos > inode->i_size)
+ ext4_set_inode_flag(inode,
+ EXT4_INODE_EOFBLOCKS);
+ }
+ ext4_mark_inode_dirty(handle, inode);
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ ret2 = ext4_journal_stop(handle);
+ if (ret2)
+ break;
+ }
+ if (ret == -ENOSPC &&
+ ext4_should_retry_alloc(inode->i_sb, &retries)) {
+ ret = 0;
+ goto retry;
+ }
+
+ return ret > 0 ? ret2 : ret;
+}
+
+static long ext4_zero_range(struct file *file, loff_t offset,
+ loff_t len, int mode)
+{
+ struct inode *inode = file_inode(file);
+ handle_t *handle = NULL;
+ unsigned int max_blocks;
+ loff_t new_size = 0;
+ int ret = 0;
+ int flags;
+ int credits;
+ int partial_begin, partial_end;
+ loff_t start, end;
+ ext4_lblk_t lblk;
+ unsigned int blkbits = inode->i_blkbits;
+
+ trace_ext4_zero_range(inode, offset, len, mode);
+
+ if (!S_ISREG(inode->i_mode))
+ return -EINVAL;
+
+ /* Call ext4_force_commit to flush all data in case of data=journal. */
+ if (ext4_should_journal_data(inode)) {
+ ret = ext4_force_commit(inode->i_sb);
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * Round up offset. This is not fallocate, we neet to zero out
+ * blocks, so convert interior block aligned part of the range to
+ * unwritten and possibly manually zero out unaligned parts of the
+ * range.
+ */
+ start = round_up(offset, 1 << blkbits);
+ end = round_down((offset + len), 1 << blkbits);
+
+ if (start < offset || end > offset + len)
+ return -EINVAL;
+ partial_begin = offset & ((1 << blkbits) - 1);
+ partial_end = (offset + len) & ((1 << blkbits) - 1);
+
+ lblk = start >> blkbits;
+ max_blocks = (end >> blkbits);
+ if (max_blocks < lblk)
+ max_blocks = 0;
+ else
+ max_blocks -= lblk;
+
+ inode_lock(inode);
+
+ /*
+ * Indirect files do not support unwritten extnets
+ */
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
+ ret = -EOPNOTSUPP;
+ goto out_mutex;
+ }
+
+ if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+ (offset + len > i_size_read(inode) ||
+ offset + len > EXT4_I(inode)->i_disksize)) {
+ new_size = offset + len;
+ ret = inode_newsize_ok(inode, new_size);
+ if (ret)
+ goto out_mutex;
+ }
+
+ flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
+ if (mode & FALLOC_FL_KEEP_SIZE)
+ flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
+
+ /* Wait all existing dio workers, newcomers will block on i_mutex */
+ inode_dio_wait(inode);
+
+ /* Preallocate the range including the unaligned edges */
+ if (partial_begin || partial_end) {
+ ret = ext4_alloc_file_blocks(file,
+ round_down(offset, 1 << blkbits) >> blkbits,
+ (round_up((offset + len), 1 << blkbits) -
+ round_down(offset, 1 << blkbits)) >> blkbits,
+ new_size, flags);
+ if (ret)
+ goto out_mutex;
+
+ }
+
+ /* Zero range excluding the unaligned edges */
+ if (max_blocks > 0) {
+ flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
+ EXT4_EX_NOCACHE);
+
+ /*
+ * Prevent page faults from reinstantiating pages we have
+ * released from page cache.
+ */
+ down_write(&EXT4_I(inode)->i_mmap_sem);
+
+ ret = ext4_break_layouts(inode);
+ if (ret) {
+ up_write(&EXT4_I(inode)->i_mmap_sem);
+ goto out_mutex;
+ }
+
+ ret = ext4_update_disksize_before_punch(inode, offset, len);
+ if (ret) {
+ up_write(&EXT4_I(inode)->i_mmap_sem);
+ goto out_mutex;
+ }
+ /* Now release the pages and zero block aligned part of pages */
+ truncate_pagecache_range(inode, start, end - 1);
+ inode->i_mtime = inode->i_ctime = current_time(inode);
+
+ ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
+ flags);
+ up_write(&EXT4_I(inode)->i_mmap_sem);
+ if (ret)
+ goto out_mutex;
+ }
+ if (!partial_begin && !partial_end)
+ goto out_mutex;
+
+ /*
+ * In worst case we have to writeout two nonadjacent unwritten
+ * blocks and update the inode
+ */
+ credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1;
+ if (ext4_should_journal_data(inode))
+ credits += 2;
+ handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ ext4_std_error(inode->i_sb, ret);
+ goto out_mutex;
+ }
+
+ inode->i_mtime = inode->i_ctime = current_time(inode);
+ if (new_size) {
+ ext4_update_inode_size(inode, new_size);
+ } else {
+ /*
+ * Mark that we allocate beyond EOF so the subsequent truncate
+ * can proceed even if the new size is the same as i_size.
+ */
+ if ((offset + len) > i_size_read(inode))
+ ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
+ }
+ ext4_mark_inode_dirty(handle, inode);
+
+ /* Zero out partial block at the edges of the range */
+ ret = ext4_zero_partial_blocks(handle, inode, offset, len);
+ if (ret >= 0)
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+
+ if (file->f_flags & O_SYNC)
+ ext4_handle_sync(handle);
+
+ ext4_journal_stop(handle);
+out_mutex:
+ inode_unlock(inode);
+ return ret;
+}
+
+/*
+ * preallocate space for a file. This implements ext4's fallocate file
+ * operation, which gets called from sys_fallocate system call.
+ * For block-mapped files, posix_fallocate should fall back to the method
+ * of writing zeroes to the required new blocks (the same behavior which is
+ * expected for file systems which do not support fallocate() system call).
+ */
+long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
+{
+ struct inode *inode = file_inode(file);
+ loff_t new_size = 0;
+ unsigned int max_blocks;
+ int ret = 0;
+ int flags;
+ ext4_lblk_t lblk;
+ unsigned int blkbits = inode->i_blkbits;
+
+ /*
+ * Encrypted inodes can't handle collapse range or insert
+ * range since we would need to re-encrypt blocks with a
+ * different IV or XTS tweak (which are based on the logical
+ * block number).
+ *
+ * XXX It's not clear why zero range isn't working, but we'll
+ * leave it disabled for encrypted inodes for now. This is a
+ * bug we should fix....
+ */
+ if (ext4_encrypted_inode(inode) &&
+ (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE |
+ FALLOC_FL_ZERO_RANGE)))
+ return -EOPNOTSUPP;
+
+ /* Return error if mode is not supported */
+ if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
+ FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
+ FALLOC_FL_INSERT_RANGE))
+ return -EOPNOTSUPP;
+
+ if (mode & FALLOC_FL_PUNCH_HOLE)
+ return ext4_punch_hole(inode, offset, len);
+
+ ret = ext4_convert_inline_data(inode);
+ if (ret)
+ return ret;
+
+ if (mode & FALLOC_FL_COLLAPSE_RANGE)
+ return ext4_collapse_range(inode, offset, len);
+
+ if (mode & FALLOC_FL_INSERT_RANGE)
+ return ext4_insert_range(inode, offset, len);
+
+ if (mode & FALLOC_FL_ZERO_RANGE)
+ return ext4_zero_range(file, offset, len, mode);
+
+ trace_ext4_fallocate_enter(inode, offset, len, mode);
+ lblk = offset >> blkbits;
+
+ max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
+ flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
+ if (mode & FALLOC_FL_KEEP_SIZE)
+ flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
+
+ inode_lock(inode);
+
+ /*
+ * We only support preallocation for extent-based files only
+ */
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+ (offset + len > i_size_read(inode) ||
+ offset + len > EXT4_I(inode)->i_disksize)) {
+ new_size = offset + len;
+ ret = inode_newsize_ok(inode, new_size);
+ if (ret)
+ goto out;
+ }
+
+ /* Wait all existing dio workers, newcomers will block on i_mutex */
+ inode_dio_wait(inode);
+
+ ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags);
+ if (ret)
+ goto out;
+
+ if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
+ ret = jbd2_complete_transaction(EXT4_SB(inode->i_sb)->s_journal,
+ EXT4_I(inode)->i_sync_tid);
+ }
+out:
+ inode_unlock(inode);
+ trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
+ return ret;
+}
+
+/*
+ * This function convert a range of blocks to written extents
+ * The caller of this function will pass the start offset and the size.
+ * all unwritten extents within this range will be converted to
+ * written extents.
+ *
+ * This function is called from the direct IO end io call back
+ * function, to convert the fallocated extents after IO is completed.
+ * Returns 0 on success.
+ */
+int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
+ loff_t offset, ssize_t len)
+{
+ unsigned int max_blocks;
+ int ret = 0;
+ int ret2 = 0;
+ struct ext4_map_blocks map;
+ unsigned int credits, blkbits = inode->i_blkbits;
+
+ map.m_lblk = offset >> blkbits;
+ max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
+
+ /*
+ * This is somewhat ugly but the idea is clear: When transaction is
+ * reserved, everything goes into it. Otherwise we rather start several
+ * smaller transactions for conversion of each extent separately.
+ */
+ if (handle) {
+ handle = ext4_journal_start_reserved(handle,
+ EXT4_HT_EXT_CONVERT);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+ credits = 0;
+ } else {
+ /*
+ * credits to insert 1 extent into extent tree
+ */
+ credits = ext4_chunk_trans_blocks(inode, max_blocks);
+ }
+ while (ret >= 0 && ret < max_blocks) {
+ map.m_lblk += ret;
+ map.m_len = (max_blocks -= ret);
+ if (credits) {
+ handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
+ credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ break;
+ }
+ }
+ ret = ext4_map_blocks(handle, inode, &map,
+ EXT4_GET_BLOCKS_IO_CONVERT_EXT);
+ if (ret <= 0)
+ ext4_warning(inode->i_sb,
+ "inode #%lu: block %u: len %u: "
+ "ext4_ext_map_blocks returned %d",
+ inode->i_ino, map.m_lblk,
+ map.m_len, ret);
+ ext4_mark_inode_dirty(handle, inode);
+ if (credits)
+ ret2 = ext4_journal_stop(handle);
+ if (ret <= 0 || ret2)
+ break;
+ }
+ if (!credits)
+ ret2 = ext4_journal_stop(handle);
+ return ret > 0 ? ret2 : ret;
+}
+
+/*
+ * If newes is not existing extent (newes->ec_pblk equals zero) find
+ * delayed extent at start of newes and update newes accordingly and
+ * return start of the next delayed extent.
+ *
+ * If newes is existing extent (newes->ec_pblk is not equal zero)
+ * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
+ * extent found. Leave newes unmodified.
+ */
+static int ext4_find_delayed_extent(struct inode *inode,
+ struct extent_status *newes)
+{
+ struct extent_status es;
+ ext4_lblk_t block, next_del;
+
+ if (newes->es_pblk == 0) {
+ ext4_es_find_delayed_extent_range(inode, newes->es_lblk,
+ newes->es_lblk + newes->es_len - 1, &es);
+
+ /*
+ * No extent in extent-tree contains block @newes->es_pblk,
+ * then the block may stay in 1)a hole or 2)delayed-extent.
+ */
+ if (es.es_len == 0)
+ /* A hole found. */
+ return 0;
+
+ if (es.es_lblk > newes->es_lblk) {
+ /* A hole found. */
+ newes->es_len = min(es.es_lblk - newes->es_lblk,
+ newes->es_len);
+ return 0;
+ }
+
+ newes->es_len = es.es_lblk + es.es_len - newes->es_lblk;
+ }
+
+ block = newes->es_lblk + newes->es_len;
+ ext4_es_find_delayed_extent_range(inode, block, EXT_MAX_BLOCKS, &es);
+ if (es.es_len == 0)
+ next_del = EXT_MAX_BLOCKS;
+ else
+ next_del = es.es_lblk;
+
+ return next_del;
+}
+/* fiemap flags we can handle specified here */
+#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
+
+static int ext4_xattr_fiemap(struct inode *inode,
+ struct fiemap_extent_info *fieinfo)
+{
+ __u64 physical = 0;
+ __u64 length;
+ __u32 flags = FIEMAP_EXTENT_LAST;
+ int blockbits = inode->i_sb->s_blocksize_bits;
+ int error = 0;
+
+ /* in-inode? */
+ if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
+ struct ext4_iloc iloc;
+ int offset; /* offset of xattr in inode */
+
+ error = ext4_get_inode_loc(inode, &iloc);
+ if (error)
+ return error;
+ physical = (__u64)iloc.bh->b_blocknr << blockbits;
+ offset = EXT4_GOOD_OLD_INODE_SIZE +
+ EXT4_I(inode)->i_extra_isize;
+ physical += offset;
+ length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
+ flags |= FIEMAP_EXTENT_DATA_INLINE;
+ brelse(iloc.bh);
+ } else { /* external block */
+ physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
+ length = inode->i_sb->s_blocksize;
+ }
+
+ if (physical)
+ error = fiemap_fill_next_extent(fieinfo, 0, physical,
+ length, flags);
+ return (error < 0 ? error : 0);
+}
+
+int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+ __u64 start, __u64 len)
+{
+ ext4_lblk_t start_blk;
+ int error = 0;
+
+ if (ext4_has_inline_data(inode)) {
+ int has_inline = 1;
+
+ error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline,
+ start, len);
+
+ if (has_inline)
+ return error;
+ }
+
+ if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
+ error = ext4_ext_precache(inode);
+ if (error)
+ return error;
+ }
+
+ /* fallback to generic here if not in extents fmt */
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
+ return generic_block_fiemap(inode, fieinfo, start, len,
+ ext4_get_block);
+
+ if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
+ return -EBADR;
+
+ if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
+ error = ext4_xattr_fiemap(inode, fieinfo);
+ } else {
+ ext4_lblk_t len_blks;
+ __u64 last_blk;
+
+ start_blk = start >> inode->i_sb->s_blocksize_bits;
+ last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
+ if (last_blk >= EXT_MAX_BLOCKS)
+ last_blk = EXT_MAX_BLOCKS-1;
+ len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
+
+ /*
+ * Walk the extent tree gathering extent information
+ * and pushing extents back to the user.
+ */
+ error = ext4_fill_fiemap_extents(inode, start_blk,
+ len_blks, fieinfo);
+ }
+ return error;
+}
+
+/*
+ * ext4_access_path:
+ * Function to access the path buffer for marking it dirty.
+ * It also checks if there are sufficient credits left in the journal handle
+ * to update path.
+ */
+static int
+ext4_access_path(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path)
+{
+ int credits, err;
+
+ if (!ext4_handle_valid(handle))
+ return 0;
+
+ /*
+ * Check if need to extend journal credits
+ * 3 for leaf, sb, and inode plus 2 (bmap and group
+ * descriptor) for each block group; assume two block
+ * groups
+ */
+ if (handle->h_buffer_credits < 7) {
+ credits = ext4_writepage_trans_blocks(inode);
+ err = ext4_ext_truncate_extend_restart(handle, inode, credits);
+ /* EAGAIN is success */
+ if (err && err != -EAGAIN)
+ return err;
+ }
+
+ err = ext4_ext_get_access(handle, inode, path);
+ return err;
+}
+
+/*
+ * ext4_ext_shift_path_extents:
+ * Shift the extents of a path structure lying between path[depth].p_ext
+ * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells
+ * if it is right shift or left shift operation.
+ */
+static int
+ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
+ struct inode *inode, handle_t *handle,
+ enum SHIFT_DIRECTION SHIFT)
+{
+ int depth, err = 0;
+ struct ext4_extent *ex_start, *ex_last;
+ bool update = 0;
+ depth = path->p_depth;
+
+ while (depth >= 0) {
+ if (depth == path->p_depth) {
+ ex_start = path[depth].p_ext;
+ if (!ex_start)
+ return -EFSCORRUPTED;
+
+ ex_last = EXT_LAST_EXTENT(path[depth].p_hdr);
+
+ err = ext4_access_path(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr))
+ update = 1;
+
+ while (ex_start <= ex_last) {
+ if (SHIFT == SHIFT_LEFT) {
+ le32_add_cpu(&ex_start->ee_block,
+ -shift);
+ /* Try to merge to the left. */
+ if ((ex_start >
+ EXT_FIRST_EXTENT(path[depth].p_hdr))
+ &&
+ ext4_ext_try_to_merge_right(inode,
+ path, ex_start - 1))
+ ex_last--;
+ else
+ ex_start++;
+ } else {
+ le32_add_cpu(&ex_last->ee_block, shift);
+ ext4_ext_try_to_merge_right(inode, path,
+ ex_last);
+ ex_last--;
+ }
+ }
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ if (--depth < 0 || !update)
+ break;
+ }
+
+ /* Update index too */
+ err = ext4_access_path(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ if (SHIFT == SHIFT_LEFT)
+ le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
+ else
+ le32_add_cpu(&path[depth].p_idx->ei_block, shift);
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ /* we are done if current index is not a starting index */
+ if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr))
+ break;
+
+ depth--;
+ }
+
+out:
+ return err;
+}
+
+/*
+ * ext4_ext_shift_extents:
+ * All the extents which lies in the range from @start to the last allocated
+ * block for the @inode are shifted either towards left or right (depending
+ * upon @SHIFT) by @shift blocks.
+ * On success, 0 is returned, error otherwise.
+ */
+static int
+ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
+ ext4_lblk_t start, ext4_lblk_t shift,
+ enum SHIFT_DIRECTION SHIFT)
+{
+ struct ext4_ext_path *path;
+ int ret = 0, depth;
+ struct ext4_extent *extent;
+ ext4_lblk_t stop, *iterator, ex_start, ex_end;
+
+ /* Let path point to the last extent */
+ path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
+ EXT4_EX_NOCACHE);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+
+ depth = path->p_depth;
+ extent = path[depth].p_ext;
+ if (!extent)
+ goto out;
+
+ stop = le32_to_cpu(extent->ee_block);
+
+ /*
+ * For left shifts, make sure the hole on the left is big enough to
+ * accommodate the shift. For right shifts, make sure the last extent
+ * won't be shifted beyond EXT_MAX_BLOCKS.
+ */
+ if (SHIFT == SHIFT_LEFT) {
+ path = ext4_find_extent(inode, start - 1, &path,
+ EXT4_EX_NOCACHE);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+ depth = path->p_depth;
+ extent = path[depth].p_ext;
+ if (extent) {
+ ex_start = le32_to_cpu(extent->ee_block);
+ ex_end = le32_to_cpu(extent->ee_block) +
+ ext4_ext_get_actual_len(extent);
+ } else {
+ ex_start = 0;
+ ex_end = 0;
+ }
+
+ if ((start == ex_start && shift > ex_start) ||
+ (shift > start - ex_end)) {
+ ret = -EINVAL;
+ goto out;
+ }
+ } else {
+ if (shift > EXT_MAX_BLOCKS -
+ (stop + ext4_ext_get_actual_len(extent))) {
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+ /*
+ * In case of left shift, iterator points to start and it is increased
+ * till we reach stop. In case of right shift, iterator points to stop
+ * and it is decreased till we reach start.
+ */
+ if (SHIFT == SHIFT_LEFT)
+ iterator = &start;
+ else
+ iterator = &stop;
+
+ /*
+ * Its safe to start updating extents. Start and stop are unsigned, so
+ * in case of right shift if extent with 0 block is reached, iterator
+ * becomes NULL to indicate the end of the loop.
+ */
+ while (iterator && start <= stop) {
+ path = ext4_find_extent(inode, *iterator, &path,
+ EXT4_EX_NOCACHE);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+ depth = path->p_depth;
+ extent = path[depth].p_ext;
+ if (!extent) {
+ EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
+ (unsigned long) *iterator);
+ return -EFSCORRUPTED;
+ }
+ if (SHIFT == SHIFT_LEFT && *iterator >
+ le32_to_cpu(extent->ee_block)) {
+ /* Hole, move to the next extent */
+ if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) {
+ path[depth].p_ext++;
+ } else {
+ *iterator = ext4_ext_next_allocated_block(path);
+ continue;
+ }
+ }
+
+ if (SHIFT == SHIFT_LEFT) {
+ extent = EXT_LAST_EXTENT(path[depth].p_hdr);
+ *iterator = le32_to_cpu(extent->ee_block) +
+ ext4_ext_get_actual_len(extent);
+ } else {
+ extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
+ if (le32_to_cpu(extent->ee_block) > 0)
+ *iterator = le32_to_cpu(extent->ee_block) - 1;
+ else
+ /* Beginning is reached, end of the loop */
+ iterator = NULL;
+ /* Update path extent in case we need to stop */
+ while (le32_to_cpu(extent->ee_block) < start)
+ extent++;
+ path[depth].p_ext = extent;
+ }
+ ret = ext4_ext_shift_path_extents(path, shift, inode,
+ handle, SHIFT);
+ if (ret)
+ break;
+ }
+out:
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ return ret;
+}
+
+/*
+ * ext4_collapse_range:
+ * This implements the fallocate's collapse range functionality for ext4
+ * Returns: 0 and non-zero on error.
+ */
+int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
+{
+ struct super_block *sb = inode->i_sb;
+ ext4_lblk_t punch_start, punch_stop;
+ handle_t *handle;
+ unsigned int credits;
+ loff_t new_size, ioffset;
+ int ret;
+
+ /*
+ * We need to test this early because xfstests assumes that a
+ * collapse range of (0, 1) will return EOPNOTSUPP if the file
+ * system does not support collapse range.
+ */
+ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ return -EOPNOTSUPP;
+
+ /* Collapse range works only on fs block size aligned offsets. */
+ if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
+ len & (EXT4_CLUSTER_SIZE(sb) - 1))
+ return -EINVAL;
+
+ if (!S_ISREG(inode->i_mode))
+ return -EINVAL;
+
+ trace_ext4_collapse_range(inode, offset, len);
+
+ punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb);
+ punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb);
+
+ /* Call ext4_force_commit to flush all data in case of data=journal. */
+ if (ext4_should_journal_data(inode)) {
+ ret = ext4_force_commit(inode->i_sb);
+ if (ret)
+ return ret;
+ }
+
+ inode_lock(inode);
+ /*
+ * There is no need to overlap collapse range with EOF, in which case
+ * it is effectively a truncate operation
+ */
+ if (offset + len >= i_size_read(inode)) {
+ ret = -EINVAL;
+ goto out_mutex;
+ }
+
+ /* Currently just for extent based files */
+ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
+ ret = -EOPNOTSUPP;
+ goto out_mutex;
+ }
+
+ /* Wait for existing dio to complete */
+ inode_dio_wait(inode);
+
+ /*
+ * Prevent page faults from reinstantiating pages we have released from
+ * page cache.
+ */
+ down_write(&EXT4_I(inode)->i_mmap_sem);
+
+ ret = ext4_break_layouts(inode);
+ if (ret)
+ goto out_mmap;
+
+ /*
+ * Need to round down offset to be aligned with page size boundary
+ * for page size > block size.
+ */
+ ioffset = round_down(offset, PAGE_SIZE);
+ /*
+ * Write tail of the last page before removed range since it will get
+ * removed from the page cache below.
+ */
+ ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, offset);
+ if (ret)
+ goto out_mmap;
+ /*
+ * Write data that will be shifted to preserve them when discarding
+ * page cache below. We are also protected from pages becoming dirty
+ * by i_mmap_sem.
+ */
+ ret = filemap_write_and_wait_range(inode->i_mapping, offset + len,
+ LLONG_MAX);
+ if (ret)
+ goto out_mmap;
+ truncate_pagecache(inode, ioffset);
+
+ credits = ext4_writepage_trans_blocks(inode);
+ handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto out_mmap;
+ }
+
+ down_write(&EXT4_I(inode)->i_data_sem);
+ ext4_discard_preallocations(inode);
+
+ ret = ext4_es_remove_extent(inode, punch_start,
+ EXT_MAX_BLOCKS - punch_start);
+ if (ret) {
+ up_write(&EXT4_I(inode)->i_data_sem);
+ goto out_stop;
+ }
+
+ ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1);
+ if (ret) {
+ up_write(&EXT4_I(inode)->i_data_sem);
+ goto out_stop;
+ }
+ ext4_discard_preallocations(inode);
+
+ ret = ext4_ext_shift_extents(inode, handle, punch_stop,
+ punch_stop - punch_start, SHIFT_LEFT);
+ if (ret) {
+ up_write(&EXT4_I(inode)->i_data_sem);
+ goto out_stop;
+ }
+
+ new_size = i_size_read(inode) - len;
+ i_size_write(inode, new_size);
+ EXT4_I(inode)->i_disksize = new_size;
+
+ up_write(&EXT4_I(inode)->i_data_sem);
+ if (IS_SYNC(inode))
+ ext4_handle_sync(handle);
+ inode->i_mtime = inode->i_ctime = current_time(inode);
+ ext4_mark_inode_dirty(handle, inode);
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+
+out_stop:
+ ext4_journal_stop(handle);
+out_mmap:
+ up_write(&EXT4_I(inode)->i_mmap_sem);
+out_mutex:
+ inode_unlock(inode);
+ return ret;
+}
+
+/*
+ * ext4_insert_range:
+ * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate.
+ * The data blocks starting from @offset to the EOF are shifted by @len
+ * towards right to create a hole in the @inode. Inode size is increased
+ * by len bytes.
+ * Returns 0 on success, error otherwise.
+ */
+int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
+{
+ struct super_block *sb = inode->i_sb;
+ handle_t *handle;
+ struct ext4_ext_path *path;
+ struct ext4_extent *extent;
+ ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0;
+ unsigned int credits, ee_len;
+ int ret = 0, depth, split_flag = 0;
+ loff_t ioffset;
+
+ /*
+ * We need to test this early because xfstests assumes that an
+ * insert range of (0, 1) will return EOPNOTSUPP if the file
+ * system does not support insert range.
+ */
+ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ return -EOPNOTSUPP;
+
+ /* Insert range works only on fs block size aligned offsets. */
+ if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
+ len & (EXT4_CLUSTER_SIZE(sb) - 1))
+ return -EINVAL;
+
+ if (!S_ISREG(inode->i_mode))
+ return -EOPNOTSUPP;
+
+ trace_ext4_insert_range(inode, offset, len);
+
+ offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb);
+ len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb);
+
+ /* Call ext4_force_commit to flush all data in case of data=journal */
+ if (ext4_should_journal_data(inode)) {
+ ret = ext4_force_commit(inode->i_sb);
+ if (ret)
+ return ret;
+ }
+
+ inode_lock(inode);
+ /* Currently just for extent based files */
+ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
+ ret = -EOPNOTSUPP;
+ goto out_mutex;
+ }
+
+ /* Check for wrap through zero */
+ if (inode->i_size + len > inode->i_sb->s_maxbytes) {
+ ret = -EFBIG;
+ goto out_mutex;
+ }
+
+ /* Offset should be less than i_size */
+ if (offset >= i_size_read(inode)) {
+ ret = -EINVAL;
+ goto out_mutex;
+ }
+
+ /* Wait for existing dio to complete */
+ inode_dio_wait(inode);
+
+ /*
+ * Prevent page faults from reinstantiating pages we have released from
+ * page cache.
+ */
+ down_write(&EXT4_I(inode)->i_mmap_sem);
+
+ ret = ext4_break_layouts(inode);
+ if (ret)
+ goto out_mmap;
+
+ /*
+ * Need to round down to align start offset to page size boundary
+ * for page size > block size.
+ */
+ ioffset = round_down(offset, PAGE_SIZE);
+ /* Write out all dirty pages */
+ ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
+ LLONG_MAX);
+ if (ret)
+ goto out_mmap;
+ truncate_pagecache(inode, ioffset);
+
+ credits = ext4_writepage_trans_blocks(inode);
+ handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto out_mmap;
+ }
+
+ /* Expand file to avoid data loss if there is error while shifting */
+ inode->i_size += len;
+ EXT4_I(inode)->i_disksize += len;
+ inode->i_mtime = inode->i_ctime = current_time(inode);
+ ret = ext4_mark_inode_dirty(handle, inode);
+ if (ret)
+ goto out_stop;
+
+ down_write(&EXT4_I(inode)->i_data_sem);
+ ext4_discard_preallocations(inode);
+
+ path = ext4_find_extent(inode, offset_lblk, NULL, 0);
+ if (IS_ERR(path)) {
+ up_write(&EXT4_I(inode)->i_data_sem);
+ goto out_stop;
+ }
+
+ depth = ext_depth(inode);
+ extent = path[depth].p_ext;
+ if (extent) {
+ ee_start_lblk = le32_to_cpu(extent->ee_block);
+ ee_len = ext4_ext_get_actual_len(extent);
+
+ /*
+ * If offset_lblk is not the starting block of extent, split
+ * the extent @offset_lblk
+ */
+ if ((offset_lblk > ee_start_lblk) &&
+ (offset_lblk < (ee_start_lblk + ee_len))) {
+ if (ext4_ext_is_unwritten(extent))
+ split_flag = EXT4_EXT_MARK_UNWRIT1 |
+ EXT4_EXT_MARK_UNWRIT2;
+ ret = ext4_split_extent_at(handle, inode, &path,
+ offset_lblk, split_flag,
+ EXT4_EX_NOCACHE |
+ EXT4_GET_BLOCKS_PRE_IO |
+ EXT4_GET_BLOCKS_METADATA_NOFAIL);
+ }
+
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ if (ret < 0) {
+ up_write(&EXT4_I(inode)->i_data_sem);
+ goto out_stop;
+ }
+ } else {
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ }
+
+ ret = ext4_es_remove_extent(inode, offset_lblk,
+ EXT_MAX_BLOCKS - offset_lblk);
+ if (ret) {
+ up_write(&EXT4_I(inode)->i_data_sem);
+ goto out_stop;
+ }
+
+ /*
+ * if offset_lblk lies in a hole which is at start of file, use
+ * ee_start_lblk to shift extents
+ */
+ ret = ext4_ext_shift_extents(inode, handle,
+ ee_start_lblk > offset_lblk ? ee_start_lblk : offset_lblk,
+ len_lblk, SHIFT_RIGHT);
+
+ up_write(&EXT4_I(inode)->i_data_sem);
+ if (IS_SYNC(inode))
+ ext4_handle_sync(handle);
+ if (ret >= 0)
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+
+out_stop:
+ ext4_journal_stop(handle);
+out_mmap:
+ up_write(&EXT4_I(inode)->i_mmap_sem);
+out_mutex:
+ inode_unlock(inode);
+ return ret;
+}
+
+/**
+ * ext4_swap_extents - Swap extents between two inodes
+ *
+ * @inode1: First inode
+ * @inode2: Second inode
+ * @lblk1: Start block for first inode
+ * @lblk2: Start block for second inode
+ * @count: Number of blocks to swap
+ * @unwritten: Mark second inode's extents as unwritten after swap
+ * @erp: Pointer to save error value
+ *
+ * This helper routine does exactly what is promise "swap extents". All other
+ * stuff such as page-cache locking consistency, bh mapping consistency or
+ * extent's data copying must be performed by caller.
+ * Locking:
+ * i_mutex is held for both inodes
+ * i_data_sem is locked for write for both inodes
+ * Assumptions:
+ * All pages from requested range are locked for both inodes
+ */
+int
+ext4_swap_extents(handle_t *handle, struct inode *inode1,
+ struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
+ ext4_lblk_t count, int unwritten, int *erp)
+{
+ struct ext4_ext_path *path1 = NULL;
+ struct ext4_ext_path *path2 = NULL;
+ int replaced_count = 0;
+
+ BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
+ BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
+ BUG_ON(!inode_is_locked(inode1));
+ BUG_ON(!inode_is_locked(inode2));
+
+ *erp = ext4_es_remove_extent(inode1, lblk1, count);
+ if (unlikely(*erp))
+ return 0;
+ *erp = ext4_es_remove_extent(inode2, lblk2, count);
+ if (unlikely(*erp))
+ return 0;
+
+ while (count) {
+ struct ext4_extent *ex1, *ex2, tmp_ex;
+ ext4_lblk_t e1_blk, e2_blk;
+ int e1_len, e2_len, len;
+ int split = 0;
+
+ path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE);
+ if (IS_ERR(path1)) {
+ *erp = PTR_ERR(path1);
+ path1 = NULL;
+ finish:
+ count = 0;
+ goto repeat;
+ }
+ path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE);
+ if (IS_ERR(path2)) {
+ *erp = PTR_ERR(path2);
+ path2 = NULL;
+ goto finish;
+ }
+ ex1 = path1[path1->p_depth].p_ext;
+ ex2 = path2[path2->p_depth].p_ext;
+ /* Do we have somthing to swap ? */
+ if (unlikely(!ex2 || !ex1))
+ goto finish;
+
+ e1_blk = le32_to_cpu(ex1->ee_block);
+ e2_blk = le32_to_cpu(ex2->ee_block);
+ e1_len = ext4_ext_get_actual_len(ex1);
+ e2_len = ext4_ext_get_actual_len(ex2);
+
+ /* Hole handling */
+ if (!in_range(lblk1, e1_blk, e1_len) ||
+ !in_range(lblk2, e2_blk, e2_len)) {
+ ext4_lblk_t next1, next2;
+
+ /* if hole after extent, then go to next extent */
+ next1 = ext4_ext_next_allocated_block(path1);
+ next2 = ext4_ext_next_allocated_block(path2);
+ /* If hole before extent, then shift to that extent */
+ if (e1_blk > lblk1)
+ next1 = e1_blk;
+ if (e2_blk > lblk2)
+ next2 = e2_blk;
+ /* Do we have something to swap */
+ if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS)
+ goto finish;
+ /* Move to the rightest boundary */
+ len = next1 - lblk1;
+ if (len < next2 - lblk2)
+ len = next2 - lblk2;
+ if (len > count)
+ len = count;
+ lblk1 += len;
+ lblk2 += len;
+ count -= len;
+ goto repeat;
+ }
+
+ /* Prepare left boundary */
+ if (e1_blk < lblk1) {
+ split = 1;
+ *erp = ext4_force_split_extent_at(handle, inode1,
+ &path1, lblk1, 0);
+ if (unlikely(*erp))
+ goto finish;
+ }
+ if (e2_blk < lblk2) {
+ split = 1;
+ *erp = ext4_force_split_extent_at(handle, inode2,
+ &path2, lblk2, 0);
+ if (unlikely(*erp))
+ goto finish;
+ }
+ /* ext4_split_extent_at() may result in leaf extent split,
+ * path must to be revalidated. */
+ if (split)
+ goto repeat;
+
+ /* Prepare right boundary */
+ len = count;
+ if (len > e1_blk + e1_len - lblk1)
+ len = e1_blk + e1_len - lblk1;
+ if (len > e2_blk + e2_len - lblk2)
+ len = e2_blk + e2_len - lblk2;
+
+ if (len != e1_len) {
+ split = 1;
+ *erp = ext4_force_split_extent_at(handle, inode1,
+ &path1, lblk1 + len, 0);
+ if (unlikely(*erp))
+ goto finish;
+ }
+ if (len != e2_len) {
+ split = 1;
+ *erp = ext4_force_split_extent_at(handle, inode2,
+ &path2, lblk2 + len, 0);
+ if (*erp)
+ goto finish;
+ }
+ /* ext4_split_extent_at() may result in leaf extent split,
+ * path must to be revalidated. */
+ if (split)
+ goto repeat;
+
+ BUG_ON(e2_len != e1_len);
+ *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth);
+ if (unlikely(*erp))
+ goto finish;
+ *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth);
+ if (unlikely(*erp))
+ goto finish;
+
+ /* Both extents are fully inside boundaries. Swap it now */
+ tmp_ex = *ex1;
+ ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2));
+ ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex));
+ ex1->ee_len = cpu_to_le16(e2_len);
+ ex2->ee_len = cpu_to_le16(e1_len);
+ if (unwritten)
+ ext4_ext_mark_unwritten(ex2);
+ if (ext4_ext_is_unwritten(&tmp_ex))
+ ext4_ext_mark_unwritten(ex1);
+
+ ext4_ext_try_to_merge(handle, inode2, path2, ex2);
+ ext4_ext_try_to_merge(handle, inode1, path1, ex1);
+ *erp = ext4_ext_dirty(handle, inode2, path2 +
+ path2->p_depth);
+ if (unlikely(*erp))
+ goto finish;
+ *erp = ext4_ext_dirty(handle, inode1, path1 +
+ path1->p_depth);
+ /*
+ * Looks scarry ah..? second inode already points to new blocks,
+ * and it was successfully dirtied. But luckily error may happen
+ * only due to journal error, so full transaction will be
+ * aborted anyway.
+ */
+ if (unlikely(*erp))
+ goto finish;
+ lblk1 += len;
+ lblk2 += len;
+ replaced_count += len;
+ count -= len;
+
+ repeat:
+ ext4_ext_drop_refs(path1);
+ kfree(path1);
+ ext4_ext_drop_refs(path2);
+ kfree(path2);
+ path1 = path2 = NULL;
+ }
+ return replaced_count;
+}