fix data corruption on NFS writeback

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Merge tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux

Pull writeback fix from Wu Fengguang:
 "Fix data corruption on NFS writeback.

  It has been in linux-next for one month"

* tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: Fix data corruption on NFS
This commit is contained in:
Linus Torvalds 2014-01-16 08:23:34 +07:00
commit 70b23ce347

View file

@ -516,13 +516,16 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb,
}
WARN_ON(inode->i_state & I_SYNC);
/*
* Skip inode if it is clean. We don't want to mess with writeback
* lists in this function since flusher thread may be doing for example
* sync in parallel and if we move the inode, it could get skipped. So
* here we make sure inode is on some writeback list and leave it there
* unless we have completely cleaned the inode.
* Skip inode if it is clean and we have no outstanding writeback in
* WB_SYNC_ALL mode. We don't want to mess with writeback lists in this
* function since flusher thread may be doing for example sync in
* parallel and if we move the inode, it could get skipped. So here we
* make sure inode is on some writeback list and leave it there unless
* we have completely cleaned the inode.
*/
if (!(inode->i_state & I_DIRTY))
if (!(inode->i_state & I_DIRTY) &&
(wbc->sync_mode != WB_SYNC_ALL ||
!mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK)))
goto out;
inode->i_state |= I_SYNC;
spin_unlock(&inode->i_lock);