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| author | Maxim Patlasov <maxim.patlasov@gmail.com> | 2011-07-10 19:37:48 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2011-07-10 19:37:48 -0400 |
| commit | 7132de744ba76930d13033061018ddd7e3e8cd91 (patch) | |
| tree | 1da773f7293e056e4849dc590dac35854662f666 /fs/ext4/extents.c | |
| parent | 275d3ba6b40d0f098693b9089c6fee9bd4e55d74 (diff) | |
ext4: fix i_blocks/quota accounting when extent insertion fails
The current implementation of ext4_free_blocks() always calls
dquot_free_block This looks quite sensible in the most cases: blocks
to be freed are associated with inode and were accounted in quota and
i_blocks some time ago.
However, there is a case when blocks to free were not accounted by the
time calling ext4_free_blocks() yet:
1. delalloc is on, write_begin pre-allocated some space in quota
2. write-back happens, ext4 allocates some blocks in ext4_ext_map_blocks()
3. then ext4_ext_map_blocks() gets an error (e.g. ENOSPC) from
ext4_ext_insert_extent() and calls ext4_free_blocks().
In this scenario, ext4_free_blocks() calls dquot_free_block() who, in
turn, decrements i_blocks for blocks which were not accounted yet (due
to delalloc) After clean umount, e2fsck reports something like:
> Inode 21, i_blocks is 5080, should be 5128. Fix<y>?
because i_blocks was erroneously decremented as explained above.
The patch fixes the problem by passing the new flag
EXT4_FREE_BLOCKS_NO_QUOT_UPDATE to ext4_free_blocks(), to request
that the dquot_free_block() call be skipped.
Signed-off-by: Maxim Patlasov <maxim.patlasov@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
Diffstat (limited to 'fs/ext4/extents.c')
| -rw-r--r-- | fs/ext4/extents.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 31ae5fbe89e..a8621388265 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3565,12 +3565,14 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, err = ext4_ext_insert_extent(handle, inode, path, &newex, flags); if (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, ext4_ext_pblock(&newex), - ext4_ext_get_actual_len(&newex), 0); + ext4_ext_get_actual_len(&newex), fb_flags); goto out2; } |