diff options
| author | Eric Sandeen <sandeen@redhat.com> | 2009-06-02 08:09:13 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-06-11 20:01:37 -0700 |
| commit | fccb0272b539368be564a8d09ae4b71134a237d3 (patch) | |
| tree | 63409a25ce867dfe130c17f234606402c6f1fafc /fs | |
| parent | 00d025abdfdcc686052ed1d9c25f10ead680e620 (diff) | |
ext4: fix ext4_free_inode() vs. ext4_claim_inode() race
(cherry picked from commit 7ce9d5d1f3c8736511daa413c64985a05b2feee3)
I was seeing fsck errors on inode bitmaps after a 4 thread
dbench run on a 4 cpu machine:
Inode bitmap differences: -50736 -(50752--50753) etc...
I believe that this is because ext4_free_inode() uses atomic
bitops, and although ext4_new_inode() *used* to also use atomic
bitops for synchronization, commit
393418676a7602e1d7d3f6e560159c65c8cbd50e changed this to use
the sb_bgl_lock, so that we could also synchronize against
read_inode_bitmap and initialization of uninit inode tables.
However, that change left ext4_free_inode using atomic bitops,
which I think leaves no synchronization between setting &
unsetting bits in the inode table.
The below patch fixes it for me, although I wonder if we're
getting at all heavy-handed with this spinlock...
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/ialloc.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index cce841fe449..f9b9fad959d 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -188,7 +188,7 @@ void ext4_free_inode (handle_t *handle, struct inode * inode) struct ext4_group_desc * gdp; struct ext4_super_block * es; struct ext4_sb_info *sbi; - int fatal = 0, err; + int fatal = 0, err, cleared; ext4_group_t flex_group; if (atomic_read(&inode->i_count) > 1) { @@ -242,10 +242,12 @@ void ext4_free_inode (handle_t *handle, struct inode * inode) goto error_return; /* Ok, now we can actually update the inode bitmaps.. */ - if (!ext4_clear_bit_atomic(sb_bgl_lock(sbi, block_group), - bit, bitmap_bh->b_data)) - ext4_error (sb, "ext4_free_inode", - "bit already cleared for inode %lu", ino); + spin_lock(sb_bgl_lock(sbi, block_group)); + cleared = ext4_clear_bit(bit, bitmap_bh->b_data); + spin_unlock(sb_bgl_lock(sbi, block_group)); + if (!cleared) + ext4_error(sb, "ext4_free_inode", + "bit already cleared for inode %lu", ino); else { gdp = ext4_get_group_desc (sb, block_group, &bh2); |