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authorMaxim Patlasov <maxim.patlasov@gmail.com>2011-07-10 19:37:48 -0400
committerTheodore Ts'o <tytso@mit.edu>2011-07-10 19:37:48 -0400
commit7132de744ba76930d13033061018ddd7e3e8cd91 (patch)
tree1da773f7293e056e4849dc590dac35854662f666
parent275d3ba6b40d0f098693b9089c6fee9bd4e55d74 (diff)
downloadlinux-7132de744ba76930d13033061018ddd7e3e8cd91.tar.bz2
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
-rw-r--r--fs/ext4/ext4.h1
-rw-r--r--fs/ext4/extents.c4
-rw-r--r--fs/ext4/mballoc.c2
3 files changed, 5 insertions, 2 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 49d2cea47382..d13f3b509886 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -526,6 +526,7 @@ struct ext4_new_group_data {
#define EXT4_FREE_BLOCKS_METADATA 0x0001
#define EXT4_FREE_BLOCKS_FORGET 0x0002
#define EXT4_FREE_BLOCKS_VALIDATED 0x0004
+#define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE 0x0008
/*
* ioctl commands
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 31ae5fbe89e5..a86213882655 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;
}
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 389386b41c98..1900ec7a1579 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4637,7 +4637,7 @@ do_more:
}
ext4_mark_super_dirty(sb);
error_return:
- if (freed)
+ if (freed && !(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE))
dquot_free_block(inode, freed);
brelse(bitmap_bh);
ext4_std_error(sb, err);