writeback: Fix data corruption on NFS
authorJan Kara <jack@suse.cz>
Fri, 13 Dec 2013 20:21:26 +0000 (04:21 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 25 Jan 2014 16:27:11 +0000 (08:27 -0800)
commitcc46cb337cf614b652b0068e6e388102bf8a9b54
tree37255541d4d0d5e0a1714ca9b237c1da626f51d9
parent02cb5b6b8b61c9e2e82cef752743168454cb227b
writeback: Fix data corruption on NFS

commit f9b0e058cbd04ada76b13afffa7e1df830543c24 upstream.

Commit 4f8ad655dbc8 "writeback: Refactor writeback_single_inode()" added
a condition to skip clean inode. However this is wrong in WB_SYNC_ALL
mode because there we also want to wait for outstanding writeback on
possibly clean inode. This was causing occasional data corruption issues
on NFS because it uses sync_inode() to make sure all outstanding writes
are flushed to the server before truncating the inode and with
sync_inode() returning prematurely file was sometimes extended back
by an outstanding write after it was truncated.

So modify the test to also check for pages under writeback in
WB_SYNC_ALL mode.

Fixes: 4f8ad655dbc82cf05d2edc11e66b78a42d38bf93
Reported-and-tested-by: Dan Duval <dan.duval@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/fs-writeback.c