]> git.baikalelectronics.ru Git - kernel.git/commit
ext4: fix ext4_free_inode() vs. ext4_claim_inode() race
authorEric Sandeen <sandeen@redhat.com>
Wed, 4 Mar 2009 23:38:18 +0000 (18:38 -0500)
committerTheodore Ts'o <tytso@mit.edu>
Wed, 4 Mar 2009 23:38:18 +0000 (18:38 -0500)
commit123e46bfcf1e6a80b5b5424f5bcccaa7cb7d1d95
tree89b30c50d6e09467f43f4f824d04838e9bb33026
parent9b689d49551a587b692ec9b1b874d82c049d90a2
ext4: fix ext4_free_inode() vs. ext4_claim_inode() race

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
f34f2009e71c1f6348f464a3ab7ac329bfe1db9f 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>
fs/ext4/ialloc.c