xfs: remove unnecessary dfops init calls in xattr code

Each xfs_defer_init() call in the xattr code uses the internal dfops
reference. In addition, a successful xfs_defer_finish() always
returns with a reset xfs_defer_ops structure.

Given that along with the fact that every xfs_defer_init() call in
the xattr code is followed up by an xfs_defer_finish(), the former
calls are no longer necessary and can be removed.

Note that the xfs_defer_init() call in the remote value copy loop of
xfs_attr_rmtval_set() is not followed by a finish, but the dfops is
unused in this instance.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/xfs/libxfs/xfs_attr.c

@@ -587,7 +587,6 @@ xfs_attr_leaf_addname(
 		 * Commit that transaction so that the node_addname() call
 		 * can manage its own transactions.
 		 */
-		xfs_defer_init(args->trans, args->trans->t_dfops);
 		error = xfs_attr3_leaf_to_node(args);
 		if (error)
 			goto out_defer_cancel;
@@ -676,7 +675,6 @@ xfs_attr_leaf_addname(
 		 * If the result is small enough, shrink it all into the inode.
 		 */
 		if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
-			xfs_defer_init(args->trans, args->trans->t_dfops);
 			error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
 			/* bp is gone due to xfs_da_shrink_inode */
 			if (error)
@@ -741,7 +739,6 @@ xfs_attr_leaf_removename(
 	 * If the result is small enough, shrink it all into the inode.
 	 */
 	if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
-		xfs_defer_init(args->trans, args->trans->t_dfops);
 		error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
 		/* bp is gone due to xfs_da_shrink_inode */
 		if (error)
@@ -870,7 +867,6 @@ xfs_attr_node_addname(
 			 */
 			xfs_da_state_free(state);
 			state = NULL;
-			xfs_defer_init(args->trans, args->trans->t_dfops);
 			error = xfs_attr3_leaf_to_node(args);
 			if (error)
 				goto out_defer_cancel;
@@ -897,7 +893,6 @@ xfs_attr_node_addname(
 		 * in the index/blkno/rmtblkno/rmtblkcnt fields and
 		 * in the index2/blkno2/rmtblkno2/rmtblkcnt2 fields.
 		 */
-		xfs_defer_init(args->trans, args->trans->t_dfops);
 		error = xfs_da3_split(state);
 		if (error)
 			goto out_defer_cancel;
@@ -995,7 +990,6 @@ xfs_attr_node_addname(
 		 * Check to see if the tree needs to be collapsed.
 		 */
 		if (retval && (state->path.active > 1)) {
-			xfs_defer_init(args->trans, args->trans->t_dfops);
 			error = xfs_da3_join(state);
 			if (error)
 				goto out_defer_cancel;
@@ -1120,7 +1114,6 @@ xfs_attr_node_removename(
 	 * Check to see if the tree needs to be collapsed.
 	 */
 	if (retval && (state->path.active > 1)) {
-		xfs_defer_init(args->trans, args->trans->t_dfops);
 		error = xfs_da3_join(state);
 		if (error)
 			goto out_defer_cancel;
@@ -1152,7 +1145,6 @@ xfs_attr_node_removename(
 			goto out;
 
 		if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
-			xfs_defer_init(args->trans, args->trans->t_dfops);
 			error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
 			/* bp is gone due to xfs_da_shrink_inode */
 			if (error)

fs/xfs/libxfs/xfs_attr_remote.c

@@ -480,7 +480,6 @@ xfs_attr_rmtval_set(
 		 * extent and then crash then the block may not contain the
 		 * correct metadata after log recovery occurs.
 		 */
-		xfs_defer_init(args->trans, args->trans->t_dfops);
 		nmap = 1;
 		error = xfs_bmapi_write(args->trans, dp, (xfs_fileoff_t)lblkno,
 				  blkcnt, XFS_BMAPI_ATTRFORK, args->total, &map,
@@ -522,7 +521,6 @@ xfs_attr_rmtval_set(
 
 		ASSERT(blkcnt > 0);
 
-		xfs_defer_init(args->trans, args->trans->t_dfops);
 		nmap = 1;
 		error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno,
 				       blkcnt, &map, &nmap,
@@ -625,7 +623,6 @@ xfs_attr_rmtval_remove(
 	blkcnt = args->rmtblkcnt;
 	done = 0;
 	while (!done) {
-		xfs_defer_init(args->trans, args->trans->t_dfops);
 		error = xfs_bunmapi(args->trans, args->dp, lblkno, blkcnt,
 				    XFS_BMAPI_ATTRFORK, 1, &done);
 		if (error)