[PATCH 3.16 090/125] Btrfs: fix filemap_flush call in btrfs_file_release

Greg Kroah-Hartman
2014-09-03T22:21:41Z

From: Chris Mason <clm@fb.com>

commit f6dc45c7a93a011dff6eb9b2ffda59c390c7705a upstream.

We should only be flushing on close if the file was flagged as needing
it during truncate. I broke this with my ordered data vs transaction
commit deadlock fix.

Thanks to Miao Xie for catching this.

Signed-off-by: Chris Mason <clm@fb.com>
Reported-by: Miao Xie <miaox@cn.fujitsu.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/btrfs/file.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1840,7 +1840,15 @@ int btrfs_release_file(struct inode *ino
{
if (filp->private_data)
btrfs_ioctl_trans_end(filp);
- filemap_flush(inode->i_mapping);
+ /*
+ * ordered_data_close is set by settattr when we are about to truncate
+ * a file from a non-zero size to a zero size. This tries to
+ * flush down new bytes that may have been written if the
+ * application were using truncate to replace a file in place.
+ */
+ if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
+ &BTRFS_I(inode)->runtime_flags))
+ filemap_flush(inode->i_mapping);
return 0;
}