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authorJan Kara <jack@suse.cz>2013-12-14 04:21:26 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-01-25 08:27:11 -0800
commitcc46cb337cf614b652b0068e6e388102bf8a9b54 (patch)
tree37255541d4d0d5e0a1714ca9b237c1da626f51d9
parent02cb5b6b8b61c9e2e82cef752743168454cb227b (diff)
downloadlinaro-lsk-cc46cb337cf614b652b0068e6e388102bf8a9b54.tar.gz
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>
-rw-r--r--fs/fs-writeback.c15
1 files changed, 9 insertions, 6 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 3be57189efd..e3ab1e4dc44 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -505,13 +505,16 @@ 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);