evie/android_kernel_oneplus_msm8998
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ext4: call ext4_ext_drop_refs() from ext4_ext_find_extent()

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In nearly all of the calls to ext4_ext_find_extent() where the caller
is trying to recycle the path object, ext4_ext_drop_refs() gets called
to release the buffer heads before the path object gets overwritten.
To simplify things for the callers, and to avoid the possibility of a
memory leak, make ext4_ext_find_extent() responsible for dropping the
buffers.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Theodore Ts'o 2014-09-01 14:38:09 -04:00
parent dfe5080939
commit 523f431ccf
1 changed files with 4 additions and 7 deletions
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11
fs/ext4/extents.c
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@ -867,8 +867,10 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
eh = ext_inode_hdr(inode); eh = ext_inode_hdr(inode);
depth = ext_depth(inode); depth = ext_depth(inode);
/* account possible depth increase */ if (path)
if (!path) { ext4_ext_drop_refs(path);
else {
/* account possible depth increase */
path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2), path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
GFP_NOFS); GFP_NOFS);
if (unlikely(!path)) if (unlikely(!path))
@ -1356,7 +1358,6 @@ repeat:
goto out; goto out;
/* refill path */ /* refill path */
ext4_ext_drop_refs(path);
path = ext4_ext_find_extent(inode, path = ext4_ext_find_extent(inode,
(ext4_lblk_t)le32_to_cpu(newext->ee_block), (ext4_lblk_t)le32_to_cpu(newext->ee_block),
ppath, gb_flags); ppath, gb_flags);
@ -1369,7 +1370,6 @@ repeat:
goto out; goto out;
/* refill path */ /* refill path */
ext4_ext_drop_refs(path);
path = ext4_ext_find_extent(inode, path = ext4_ext_find_extent(inode,
(ext4_lblk_t)le32_to_cpu(newext->ee_block), (ext4_lblk_t)le32_to_cpu(newext->ee_block),
ppath, gb_flags); ppath, gb_flags);
@ -3319,7 +3319,6 @@ static int ext4_split_extent(handle_t *handle,
* Update path is required because previous ext4_split_extent_at() may * Update path is required because previous ext4_split_extent_at() may
* result in split of original leaf or extent zeroout. * result in split of original leaf or extent zeroout.
*/ */
ext4_ext_drop_refs(path);
path = ext4_ext_find_extent(inode, map->m_lblk, ppath, 0); path = ext4_ext_find_extent(inode, map->m_lblk, ppath, 0);
if (IS_ERR(path)) if (IS_ERR(path))
return PTR_ERR(path); return PTR_ERR(path);
@ -3718,7 +3717,6 @@ static int ext4_convert_unwritten_extents_endio(handle_t *handle,
EXT4_GET_BLOCKS_CONVERT); EXT4_GET_BLOCKS_CONVERT);
if (err < 0) if (err < 0)
return err; return err;
ext4_ext_drop_refs(path);
path = ext4_ext_find_extent(inode, map->m_lblk, ppath, 0); path = ext4_ext_find_extent(inode, map->m_lblk, ppath, 0);
if (IS_ERR(path)) if (IS_ERR(path))
return PTR_ERR(path); return PTR_ERR(path);
@ -3947,7 +3945,6 @@ convert_initialized_extent(handle_t *handle, struct inode *inode,
EXT4_GET_BLOCKS_CONVERT_UNWRITTEN); EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
if (err < 0) if (err < 0)
return err; return err;
ext4_ext_drop_refs(path);
path = ext4_ext_find_extent(inode, map->m_lblk, ppath, 0); path = ext4_ext_find_extent(inode, map->m_lblk, ppath, 0);
if (IS_ERR(path)) if (IS_ERR(path))
return PTR_ERR(path); return PTR_ERR(path);