xfs: remove all boilerplate defer init/finish code

At this point, the transaction subsystem completely manages deferred
items internally such that the common and boilerplate
xfs_trans_alloc() -> xfs_defer_init() -> xfs_defer_finish() ->
xfs_trans_commit() sequence can be replaced with a simple
transaction allocation and commit.

Remove all such boilerplate deferred ops code. In doing so, we
change each case over to use the dfops in the transaction and
specifically eliminate:

- The on-stack dfops and associated xfs_defer_init() call, as the
  internal dfops is initialized on transaction allocation.
- xfs_bmap_finish() calls that precede a final xfs_trans_commit() of
  a transaction.
- xfs_defer_cancel() calls in error handlers that precede a
  transaction cancel.

The only deferred ops calls that remain are those that are
non-deterministic with respect to the final commit of the associated
transaction or are open-coded due to special handling.

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>

1 files changed, 13 insertions, 66 deletions

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 7d7d7e95fa17..c47183a2f167 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1142,7 +1142,6 @@ xfs_create(
 	struct xfs_inode	*ip = NULL;
 	struct xfs_trans	*tp = NULL;
 	int			error;
-	struct xfs_defer_ops	dfops;
 	bool                    unlock_dp_on_error = false;
 	prid_t			prid;
 	struct xfs_dquot	*udqp = NULL;
@@ -1194,8 +1193,6 @@ xfs_create(
 	xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
 	unlock_dp_on_error = true;
 
-	xfs_defer_init(tp, &dfops);
-
 	/*
 	 * Reserve disk quota and the inode.
 	 */
@@ -1236,11 +1233,11 @@ xfs_create(
 	if (is_dir) {
 		error = xfs_dir_init(tp, ip, dp);
 		if (error)
-			goto out_bmap_cancel;
+			goto out_trans_cancel;
 
 		error = xfs_bumplink(tp, dp);
 		if (error)
-			goto out_bmap_cancel;
+			goto out_trans_cancel;
 	}
 
 	/*
@@ -1258,10 +1255,6 @@ xfs_create(
 	 */
 	xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
 
-	error = xfs_defer_finish(&tp, &dfops);
-	if (error)
-		goto out_bmap_cancel;
-
 	error = xfs_trans_commit(tp);
 	if (error)
 		goto out_release_inode;
@@ -1273,8 +1266,6 @@ xfs_create(
 	*ipp = ip;
 	return 0;
 
- out_bmap_cancel:
-	xfs_defer_cancel(&dfops);
  out_trans_cancel:
 	xfs_trans_cancel(tp);
  out_release_inode:
@@ -1399,7 +1390,6 @@ xfs_link(
 	xfs_mount_t		*mp = tdp->i_mount;
 	xfs_trans_t		*tp;
 	int			error;
-	struct xfs_defer_ops	dfops;
 	int			resblks;
 
 	trace_xfs_link(tdp, target_name);
@@ -1448,8 +1438,6 @@ xfs_link(
 			goto error_return;
 	}
 
-	xfs_defer_init(tp, &dfops);
-
 	/*
 	 * Handle initial link state of O_TMPFILE inode
 	 */
@@ -1478,12 +1466,6 @@ xfs_link(
 	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
 		xfs_trans_set_sync(tp);
 
-	error = xfs_defer_finish(&tp, &dfops);
-	if (error) {
-		xfs_defer_cancel(&dfops);
-		goto error_return;
-	}
-
 	return xfs_trans_commit(tp);
 
  error_return:
@@ -1719,7 +1701,6 @@ xfs_inactive_truncate(
 {
 	struct xfs_mount	*mp = ip->i_mount;
 	struct xfs_trans	*tp;
-	struct xfs_defer_ops	dfops;
 	int			error;
 
 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
@@ -1727,8 +1708,6 @@ xfs_inactive_truncate(
 		ASSERT(XFS_FORCED_SHUTDOWN(mp));
 		return error;
 	}
-	xfs_defer_init(tp, &dfops);
-
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
 	xfs_trans_ijoin(tp, ip, 0);
 
@@ -1769,7 +1748,6 @@ STATIC int
 xfs_inactive_ifree(
 	struct xfs_inode *ip)
 {
-	struct xfs_defer_ops	dfops;
 	struct xfs_mount	*mp = ip->i_mount;
 	struct xfs_trans	*tp;
 	int			error;
@@ -1806,7 +1784,6 @@ xfs_inactive_ifree(
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
 	xfs_trans_ijoin(tp, ip, 0);
 
-	xfs_defer_init(tp, &dfops);
 	error = xfs_ifree(tp, ip);
 	if (error) {
 		/*
@@ -1833,12 +1810,6 @@ xfs_inactive_ifree(
 	 * Just ignore errors at this point.  There is nothing we can do except
 	 * to try to keep going. Make sure it's not a silent error.
 	 */
-	error = xfs_defer_finish(&tp, &dfops);
-	if (error) {
-		xfs_notice(mp, "%s: xfs_defer_finish returned error %d",
-			__func__, error);
-		xfs_defer_cancel(&dfops);
-	}
 	error = xfs_trans_commit(tp);
 	if (error)
 		xfs_notice(mp, "%s: xfs_trans_commit returned error %d",
@@ -2569,7 +2540,6 @@ xfs_remove(
 	xfs_trans_t             *tp = NULL;
 	int			is_dir = S_ISDIR(VFS_I(ip)->i_mode);
 	int                     error = 0;
-	struct xfs_defer_ops	dfops;
 	uint			resblks;
 
 	trace_xfs_remove(dp, name);
@@ -2649,11 +2619,10 @@ xfs_remove(
 	if (error)
 		goto out_trans_cancel;
 
-	xfs_defer_init(tp, &dfops);
 	error = xfs_dir_removename(tp, dp, name, ip->i_ino, resblks);
 	if (error) {
 		ASSERT(error != -ENOENT);
-		goto out_bmap_cancel;
+		goto out_trans_cancel;
 	}
 
 	/*
@@ -2664,10 +2633,6 @@ xfs_remove(
 	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
 		xfs_trans_set_sync(tp);
 
-	error = xfs_defer_finish(&tp, &dfops);
-	if (error)
-		goto out_bmap_cancel;
-
 	error = xfs_trans_commit(tp);
 	if (error)
 		goto std_return;
@@ -2677,8 +2642,6 @@ xfs_remove(
 
 	return 0;
 
- out_bmap_cancel:
-	xfs_defer_cancel(&dfops);
  out_trans_cancel:
 	xfs_trans_cancel(tp);
  std_return:
@@ -2740,9 +2703,6 @@ static int
 xfs_finish_rename(
 	struct xfs_trans	*tp)
 {
-	struct xfs_defer_ops	*dfops = tp->t_dfops;
-	int			error;
-
 	/*
 	 * If this is a synchronous mount, make sure that the rename transaction
 	 * goes to disk before returning to the user.
@@ -2750,13 +2710,6 @@ xfs_finish_rename(
 	if (tp->t_mountp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
 		xfs_trans_set_sync(tp);
 
-	error = xfs_defer_finish(&tp, dfops);
-	if (error) {
-		xfs_defer_cancel(dfops);
-		xfs_trans_cancel(tp);
-		return error;
-	}
-
 	return xfs_trans_commit(tp);
 }
 
@@ -2869,7 +2822,6 @@ xfs_cross_rename(
 	return xfs_finish_rename(tp);
 
 out_trans_abort:
-	xfs_defer_cancel(tp->t_dfops);
 	xfs_trans_cancel(tp);
 	return error;
 }
@@ -2924,7 +2876,6 @@ xfs_rename(
 {
 	struct xfs_mount	*mp = src_dp->i_mount;
 	struct xfs_trans	*tp;
-	struct xfs_defer_ops	dfops;
 	struct xfs_inode	*wip = NULL;		/* whiteout inode */
 	struct xfs_inode	*inodes[__XFS_SORT_INODES];
 	int			num_inodes = __XFS_SORT_INODES;
@@ -3006,8 +2957,6 @@ xfs_rename(
 		goto out_trans_cancel;
 	}
 
-	xfs_defer_init(tp, &dfops);
-
 	/* RENAME_EXCHANGE is unique from here on. */
 	if (flags & RENAME_EXCHANGE)
 		return xfs_cross_rename(tp, src_dp, src_name, src_ip,
@@ -3035,7 +2984,7 @@ xfs_rename(
 		error = xfs_dir_createname(tp, target_dp, target_name,
 					   src_ip->i_ino, spaceres);
 		if (error)
-			goto out_bmap_cancel;
+			goto out_trans_cancel;
 
 		xfs_trans_ichgtime(tp, target_dp,
 					XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
@@ -3043,7 +2992,7 @@ xfs_rename(
 		if (new_parent && src_is_directory) {
 			error = xfs_bumplink(tp, target_dp);
 			if (error)
-				goto out_bmap_cancel;
+				goto out_trans_cancel;
 		}
 	} else { /* target_ip != NULL */
 		/*
@@ -3074,7 +3023,7 @@ xfs_rename(
 		error = xfs_dir_replace(tp, target_dp, target_name,
 					src_ip->i_ino, spaceres);
 		if (error)
-			goto out_bmap_cancel;
+			goto out_trans_cancel;
 
 		xfs_trans_ichgtime(tp, target_dp,
 					XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
@@ -3085,7 +3034,7 @@ xfs_rename(
 		 */
 		error = xfs_droplink(tp, target_ip);
 		if (error)
-			goto out_bmap_cancel;
+			goto out_trans_cancel;
 
 		if (src_is_directory) {
 			/*
@@ -3093,7 +3042,7 @@ xfs_rename(
 			 */
 			error = xfs_droplink(tp, target_ip);
 			if (error)
-				goto out_bmap_cancel;
+				goto out_trans_cancel;
 		}
 	} /* target_ip != NULL */
 
@@ -3109,7 +3058,7 @@ xfs_rename(
 					target_dp->i_ino, spaceres);
 		ASSERT(error != -EEXIST);
 		if (error)
-			goto out_bmap_cancel;
+			goto out_trans_cancel;
 	}
 
 	/*
@@ -3135,7 +3084,7 @@ xfs_rename(
 		 */
 		error = xfs_droplink(tp, src_dp);
 		if (error)
-			goto out_bmap_cancel;
+			goto out_trans_cancel;
 	}
 
 	/*
@@ -3150,7 +3099,7 @@ xfs_rename(
 		error = xfs_dir_removename(tp, src_dp, src_name, src_ip->i_ino,
 					   spaceres);
 	if (error)
-		goto out_bmap_cancel;
+		goto out_trans_cancel;
 
 	/*
 	 * For whiteouts, we need to bump the link count on the whiteout inode.
@@ -3164,10 +3113,10 @@ xfs_rename(
 		ASSERT(VFS_I(wip)->i_nlink == 0);
 		error = xfs_bumplink(tp, wip);
 		if (error)
-			goto out_bmap_cancel;
+			goto out_trans_cancel;
 		error = xfs_iunlink_remove(tp, wip);
 		if (error)
-			goto out_bmap_cancel;
+			goto out_trans_cancel;
 		xfs_trans_log_inode(tp, wip, XFS_ILOG_CORE);
 
 		/*
@@ -3188,8 +3137,6 @@ xfs_rename(
 		IRELE(wip);
 	return error;
 
-out_bmap_cancel:
-	xfs_defer_cancel(&dfops);
 out_trans_cancel:
 	xfs_trans_cancel(tp);
 out_release_wip: