[PATCH 031/102] xfs: always return with the iolock held from

[Dave Chinner <david@xxxxxxxxxxxxx>]

From: Christoph Hellwig <hch@xxxxxxxxxxxxx>

Upstream commit: 5bf1f26227a59b9634e95eb3c7c012b766e5e6a0
 xfs_file_aio_write_checks

While xfs_iunlock is fine with 0 lockflags the calling conventions are much
cleaner if xfs_file_aio_write_checks never returns without the iolock held.

Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Ben Myers <bpm@xxxxxxx>
---
 fs/xfs/linux-2.6/xfs_file.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index e3076f0..b9e3101 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -631,7 +631,9 @@ out_lock:
 /*
  * Common pre-write limit and setup checks.
  *
- * Returns with iolock held according to @iolock.
+ * Called with the iolocked held either shared and exclusive according to
+ * @iolock, and returns with it held.  Might upgrade the iolock to exclusive
+ * if called for a direct write beyond i_size.
  */
 STATIC ssize_t
 xfs_file_aio_write_checks(
@@ -648,8 +650,7 @@ xfs_file_aio_write_checks(
 restart:
        error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode));
        if (error) {
-               xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock);
-               *iolock = 0;
+               xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);
                return error;
        }
 
-- 
1.7.10