xfs: create libxfs helper to exchange two directory entries

Create a new libxfs function to exchange two directory entries.
The upcoming metadata directory feature will need this to replace a
metadata inode directory entry.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 14 insertions, 98 deletions

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 8da67322791f..363e98ee974c 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -2238,109 +2238,25 @@ xfs_cross_rename(
 	struct xfs_parent_args	*ip2_ppargs,
 	int			spaceres)
 {
-	int			error = 0;
-	int			ip1_flags = 0;
-	int			ip2_flags = 0;
-	int			dp2_flags = 0;
-
-	/* Swap inode number for dirent in first parent */
-	error = xfs_dir_replace(tp, dp1, name1, ip2->i_ino, spaceres);
-	if (error)
-		goto out_trans_abort;
+	struct xfs_dir_update	du1 = {
+		.dp		= dp1,
+		.name		= name1,
+		.ip		= ip1,
+		.ppargs		= ip1_ppargs,
+	};
+	struct xfs_dir_update	du2 = {
+		.dp		= dp2,
+		.name		= name2,
+		.ip		= ip2,
+		.ppargs		= ip2_ppargs,
+	};
+	int			error;
 
-	/* Swap inode number for dirent in second parent */
-	error = xfs_dir_replace(tp, dp2, name2, ip1->i_ino, spaceres);
+	error = xfs_dir_exchange_children(tp, &du1, &du2, spaceres);
 	if (error)
 		goto out_trans_abort;
 
 	/*
-	 * If we're renaming one or more directories across different parents,
-	 * update the respective ".." entries (and link counts) to match the new
-	 * parents.
-	 */
-	if (dp1 != dp2) {
-		dp2_flags = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
-
-		if (S_ISDIR(VFS_I(ip2)->i_mode)) {
-			error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,
-						dp1->i_ino, spaceres);
-			if (error)
-				goto out_trans_abort;
-
-			/* transfer ip2 ".." reference to dp1 */
-			if (!S_ISDIR(VFS_I(ip1)->i_mode)) {
-				error = xfs_droplink(tp, dp2);
-				if (error)
-					goto out_trans_abort;
-				xfs_bumplink(tp, dp1);
-			}
-
-			/*
-			 * Although ip1 isn't changed here, userspace needs
-			 * to be warned about the change, so that applications
-			 * relying on it (like backup ones), will properly
-			 * notify the change
-			 */
-			ip1_flags |= XFS_ICHGTIME_CHG;
-			ip2_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
-		}
-
-		if (S_ISDIR(VFS_I(ip1)->i_mode)) {
-			error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,
-						dp2->i_ino, spaceres);
-			if (error)
-				goto out_trans_abort;
-
-			/* transfer ip1 ".." reference to dp2 */
-			if (!S_ISDIR(VFS_I(ip2)->i_mode)) {
-				error = xfs_droplink(tp, dp1);
-				if (error)
-					goto out_trans_abort;
-				xfs_bumplink(tp, dp2);
-			}
-
-			/*
-			 * Although ip2 isn't changed here, userspace needs
-			 * to be warned about the change, so that applications
-			 * relying on it (like backup ones), will properly
-			 * notify the change
-			 */
-			ip1_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
-			ip2_flags |= XFS_ICHGTIME_CHG;
-		}
-	}
-
-	/* Schedule parent pointer replacements */
-	if (ip1_ppargs) {
-		error = xfs_parent_replacename(tp, ip1_ppargs, dp1, name1, dp2,
-				name2, ip1);
-		if (error)
-			goto out_trans_abort;
-	}
-
-	if (ip2_ppargs) {
-		error = xfs_parent_replacename(tp, ip2_ppargs, dp2, name2, dp1,
-				name1, ip2);
-		if (error)
-			goto out_trans_abort;
-	}
-
-	if (ip1_flags) {
-		xfs_trans_ichgtime(tp, ip1, ip1_flags);
-		xfs_trans_log_inode(tp, ip1, XFS_ILOG_CORE);
-	}
-	if (ip2_flags) {
-		xfs_trans_ichgtime(tp, ip2, ip2_flags);
-		xfs_trans_log_inode(tp, ip2, XFS_ILOG_CORE);
-	}
-	if (dp2_flags) {
-		xfs_trans_ichgtime(tp, dp2, dp2_flags);
-		xfs_trans_log_inode(tp, dp2, XFS_ILOG_CORE);
-	}
-	xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
-	xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE);
-
-	/*
 	 * Inform our hook clients that we've finished an exchange operation as
 	 * follows: removed the source and target files from their directories;
 	 * added the target to the source directory; and added the source to