xfs: embed the xlog_op_header in the commit record

Remove the final case where xlog_write() has to prepend an opheader
to a log transaction. Similar to the start record, the commit record
is just an empty opheader with a XLOG_COMMIT_TRANS type, so we can
just make this the payload for the region being passed to
xlog_write() and remove the special handling in xlog_write() for
the commit record.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 6 insertions, 16 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 00e9af9b246a..c23a15c56ef1 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -2267,11 +2267,10 @@ xlog_write_calc_vec_length(
 
 	/* Don't account for regions with embedded ophdrs */
 	if (optype && headers > 0) {
-		if (optype & XLOG_UNMOUNT_TRANS)
-			headers--;
+		headers--;
 		if (optype & XLOG_START_TRANS) {
-			ASSERT(headers >= 2);
-			headers -= 2;
+			ASSERT(headers >= 1);
+			headers--;
 		}
 	}
 
@@ -2472,14 +2471,6 @@ xlog_write(
 	int			data_cnt = 0;
 	int			error = 0;
 
-	/*
-	 * If this is a commit or unmount transaction, we don't need a start
-	 * record to be written.  We do, however, have to account for the commit
-	 * header that gets written. Hence we always have to account for an
-	 * extra xlog_op_header here for commit records.
-	 */
-	if (optype & XLOG_COMMIT_TRANS)
-		ticket->t_curr_res -= sizeof(struct xlog_op_header);
 	if (ticket->t_curr_res < 0) {
 		xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
 		     "ctx ticket reservation ran out. Need to up reservation");
@@ -2536,14 +2527,13 @@ xlog_write(
 			/*
 			 * The XLOG_START_TRANS has embedded ophdrs for the
 			 * start record and transaction header. They will always
-			 * be the first two regions in the lv chain.
+			 * be the first two regions in the lv chain. Commit and
+			 * unmount records also have embedded ophdrs.
 			 */
-			if (optype & XLOG_START_TRANS) {
+			if (optype) {
 				ophdr = reg->i_addr;
 				if (index)
 					optype &= ~XLOG_START_TRANS;
-			} else if (optype & XLOG_UNMOUNT_TRANS) {
-				ophdr = reg->i_addr;
 			} else {
 				ophdr = xlog_write_setup_ophdr(log, ptr,
 							ticket, optype);