xfs: unlock the inode before log force in xfs_fsync

Only read the LSN we need to push to with the ilock held, and then release
it before we do the log force to improve concurrency.

This also removes the only direct caller of _xfs_trans_commit, thus
allowing it to be merged into the plain xfs_trans_commit again.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>


diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index efc147f..b64c8c7 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -1790,9 +1790,7 @@
 }
 
 /*
- * xfs_trans_commit
- *
- * Commit the given transaction to the log a/synchronously.
+ * Commit the given transaction to the log.
  *
  * XFS disk error handling mechanism is not based on a typical
  * transaction abort mechanism. Logically after the filesystem
@@ -1804,10 +1802,9 @@
  * Do not reference the transaction structure after this call.
  */
 int
-_xfs_trans_commit(
+xfs_trans_commit(
 	struct xfs_trans	*tp,
-	uint			flags,
-	int			*log_flushed)
+	uint			flags)
 {
 	struct xfs_mount	*mp = tp->t_mountp;
 	xfs_lsn_t		commit_lsn = -1;
@@ -1866,7 +1863,7 @@
 	if (sync) {
 		if (!error) {
 			error = _xfs_log_force_lsn(mp, commit_lsn,
-				      XFS_LOG_SYNC, log_flushed);
+				      XFS_LOG_SYNC, NULL);
 		}
 		XFS_STATS_INC(xs_trans_sync);
 	} else {