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ext4: remove messy logic from ext4_ext_rm_leaf

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- Both callers(truncate and punch_hole) already aligned left end point
  so we no longer need split logic here.
- Remove dead duplicated code.
- Call ext4_ext_dirty only after we have updated eh_entries, otherwise
  we'll loose entries update. Regression caused by d583fb87a3
  266'th testcase in xfstests (http://patchwork.ozlabs.org/patch/120872)

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Dmitry Monakhov 2011-10-25 05:35:05 -04:00 committed by Theodore Ts'o
parent 1939dd84b3
commit 750c9c47a5
1 changed files with 12 additions and 91 deletions
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103
fs/ext4/extents.c
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@ -2311,13 +2311,12 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
int err = 0, correct_index = 0;
int depth = ext_depth(inode), credits;
struct ext4_extent_header *eh;
ext4_lblk_t a, b, block;
ext4_lblk_t a, b;
unsigned num;
ext4_lblk_t ex_ee_block;
unsigned short ex_ee_len;
unsigned uninitialized = 0;
struct ext4_extent *ex;
struct ext4_map_blocks map;
/* the header must be checked already in ext4_ext_remove_space() */
ext_debug("truncate since %u in leaf\n", start);
@ -2360,86 +2359,18 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
ex_ee_block = le32_to_cpu(ex->ee_block);
ex_ee_len = ext4_ext_get_actual_len(ex);
continue;
} else if (a != ex_ee_block &&
b != ex_ee_block + ex_ee_len - 1) {
/*
* If this is a truncate, then this condition should
* never happen because at least one of the end points
* needs to be on the edge of the extent.
*/
if (end == EXT_MAX_BLOCKS - 1) {
ext_debug(" bad truncate %u:%u\n",
start, end);
block = 0;
num = 0;
err = -EIO;
goto out;
}
/*
* else this is a hole punch, so the extent needs to
* be split since neither edge of the hole is on the
* extent edge
*/
else{
map.m_pblk = ext4_ext_pblock(ex);
map.m_lblk = ex_ee_block;
map.m_len = b - ex_ee_block;
err = ext4_split_extent(handle,
inode, path, &map, 0,
EXT4_GET_BLOCKS_PUNCH_OUT_EXT |
EXT4_GET_BLOCKS_PRE_IO);
if (err < 0)
goto out;
ex_ee_len = ext4_ext_get_actual_len(ex);
b = ex_ee_block+ex_ee_len - 1 < end ?
ex_ee_block+ex_ee_len - 1 : end;
/* Then remove tail of this extent */
block = ex_ee_block;
num = a - block;
}
} else if (b != ex_ee_block + ex_ee_len - 1) {
EXT4_ERROR_INODE(inode," bad truncate %u:%u\n",
start, end);
err = -EIO;
goto out;
} else if (a != ex_ee_block) {
/* remove tail of the extent */
block = ex_ee_block;
num = a - block;
} else if (b != ex_ee_block + ex_ee_len - 1) {
/* remove head of the extent */
block = b;
num = ex_ee_block + ex_ee_len - b;
/*
* If this is a truncate, this condition
* should never happen
*/
if (end == EXT_MAX_BLOCKS - 1) {
ext_debug(" bad truncate %u:%u\n",
start, end);
err = -EIO;
goto out;
}
num = a - ex_ee_block;
} else {
/* remove whole extent: excellent! */
block = ex_ee_block;
num = 0;
if (a != ex_ee_block) {
ext_debug(" bad truncate %u:%u\n",
start, end);
err = -EIO;
goto out;
}
if (b != ex_ee_block + ex_ee_len - 1) {
ext_debug(" bad truncate %u:%u\n",
start, end);
err = -EIO;
goto out;
}
}
/*
* 3 for leaf, sb, and inode plus 2 (bmap and group
* descriptor) for each block group; assume two block
@ -2466,19 +2397,10 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
if (err)
goto out;
if (num == 0) {
if (num == 0)
/* this extent is removed; mark slot entirely unused */
ext4_ext_store_pblock(ex, 0);
} else if (block != ex_ee_block) {
/*
* If this was a head removal, then we need to update
* the physical block since it is now at a different
* location
*/
ext4_ext_store_pblock(ex, ext4_ext_pblock(ex) + (b-a));
}
ex->ee_block = cpu_to_le32(block);
ex->ee_len = cpu_to_le16(num);
/*
* Do not mark uninitialized if all the blocks in the
@ -2486,11 +2408,6 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
*/
if (uninitialized && num)
ext4_ext_mark_uninitialized(ex);
err = ext4_ext_dirty(handle, inode, path + depth);
if (err)
goto out;
/*
* If the extent was completely released,
* we need to remove it from the leaf
@ -2513,6 +2430,10 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
} else
*partial_cluster = 0;
err = ext4_ext_dirty(handle, inode, path + depth);
if (err)
goto out;
ext_debug("new extent: %u:%u:%llu\n", block, num,
ext4_ext_pblock(ex));
ex--;