Merge branch 'xfs-misc-fixes-for-3.20-1' into for-next
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 41f804e..9916aef 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -2656,6 +2656,124 @@
 }
 
 /*
+ * xfs_cross_rename()
+ *
+ * responsible for handling RENAME_EXCHANGE flag in renameat2() sytemcall
+ */
+STATIC int
+xfs_cross_rename(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*dp1,
+	struct xfs_name		*name1,
+	struct xfs_inode	*ip1,
+	struct xfs_inode	*dp2,
+	struct xfs_name		*name2,
+	struct xfs_inode	*ip2,
+	struct xfs_bmap_free	*free_list,
+	xfs_fsblock_t		*first_block,
+	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,
+				first_block, free_list, spaceres);
+	if (error)
+		goto out;
+
+	/* Swap inode number for dirent in second parent */
+	error = xfs_dir_replace(tp, dp2, name2,
+				ip1->i_ino,
+				first_block, free_list, spaceres);
+	if (error)
+		goto out;
+
+	/*
+	 * 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(ip2->i_d.di_mode)) {
+			error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,
+						dp1->i_ino, first_block,
+						free_list, spaceres);
+			if (error)
+				goto out;
+
+			/* transfer ip2 ".." reference to dp1 */
+			if (!S_ISDIR(ip1->i_d.di_mode)) {
+				error = xfs_droplink(tp, dp2);
+				if (error)
+					goto out;
+				error = xfs_bumplink(tp, dp1);
+				if (error)
+					goto out;
+			}
+
+			/*
+			 * 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(ip1->i_d.di_mode)) {
+			error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,
+						dp2->i_ino, first_block,
+						free_list, spaceres);
+			if (error)
+				goto out;
+
+			/* transfer ip1 ".." reference to dp2 */
+			if (!S_ISDIR(ip2->i_d.di_mode)) {
+				error = xfs_droplink(tp, dp1);
+				if (error)
+					goto out;
+				error = xfs_bumplink(tp, dp2);
+				if (error)
+					goto out;
+			}
+
+			/*
+			 * 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;
+		}
+	}
+
+	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);
+out:
+	return error;
+}
+
+/*
  * xfs_rename
  */
 int
@@ -2665,7 +2783,8 @@
 	xfs_inode_t	*src_ip,
 	xfs_inode_t	*target_dp,
 	struct xfs_name	*target_name,
-	xfs_inode_t	*target_ip)
+	xfs_inode_t	*target_ip,
+	unsigned int	flags)
 {
 	xfs_trans_t	*tp = NULL;
 	xfs_mount_t	*mp = src_dp->i_mount;
@@ -2743,6 +2862,18 @@
 	}
 
 	/*
+	 * Handle RENAME_EXCHANGE flags
+	 */
+	if (flags & RENAME_EXCHANGE) {
+		error = xfs_cross_rename(tp, src_dp, src_name, src_ip,
+					 target_dp, target_name, target_ip,
+					 &free_list, &first_block, spaceres);
+		if (error)
+			goto abort_return;
+		goto finish_rename;
+	}
+
+	/*
 	 * Set up the target.
 	 */
 	if (target_ip == NULL) {
@@ -2881,6 +3012,7 @@
 	if (new_parent)
 		xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);
 
+finish_rename:
 	/*
 	 * If this is a synchronous mount, make sure that the
 	 * rename transaction goes to disk before returning to
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 4ed2ba9..f772296 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -338,7 +338,7 @@
 int		xfs_rename(struct xfs_inode *src_dp, struct xfs_name *src_name,
 			   struct xfs_inode *src_ip, struct xfs_inode *target_dp,
 			   struct xfs_name *target_name,
-			   struct xfs_inode *target_ip);
+			   struct xfs_inode *target_ip, unsigned int flags);
 
 void		xfs_ilock(xfs_inode_t *, uint);
 int		xfs_ilock_nowait(xfs_inode_t *, uint);
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index c50311c..ce80eeb 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -380,18 +380,27 @@
 	struct inode	*odir,
 	struct dentry	*odentry,
 	struct inode	*ndir,
-	struct dentry	*ndentry)
+	struct dentry	*ndentry,
+	unsigned int	flags)
 {
 	struct inode	*new_inode = ndentry->d_inode;
+	int		omode = 0;
 	struct xfs_name	oname;
 	struct xfs_name	nname;
 
-	xfs_dentry_to_name(&oname, odentry, 0);
+	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
+		return -EINVAL;
+
+	/* if we are exchanging files, we need to set i_mode of both files */
+	if (flags & RENAME_EXCHANGE)
+		omode = ndentry->d_inode->i_mode;
+
+	xfs_dentry_to_name(&oname, odentry, omode);
 	xfs_dentry_to_name(&nname, ndentry, odentry->d_inode->i_mode);
 
 	return xfs_rename(XFS_I(odir), &oname, XFS_I(odentry->d_inode),
-			  XFS_I(ndir), &nname, new_inode ?
-						XFS_I(new_inode) : NULL);
+			  XFS_I(ndir), &nname,
+			  new_inode ? XFS_I(new_inode) : NULL, flags);
 }
 
 /*
@@ -1144,7 +1153,7 @@
 	 */
 	.rmdir			= xfs_vn_unlink,
 	.mknod			= xfs_vn_mknod,
-	.rename			= xfs_vn_rename,
+	.rename2		= xfs_vn_rename,
 	.get_acl		= xfs_get_acl,
 	.set_acl		= xfs_set_acl,
 	.getattr		= xfs_vn_getattr,
@@ -1172,7 +1181,7 @@
 	 */
 	.rmdir			= xfs_vn_unlink,
 	.mknod			= xfs_vn_mknod,
-	.rename			= xfs_vn_rename,
+	.rename2		= xfs_vn_rename,
 	.get_acl		= xfs_get_acl,
 	.set_acl		= xfs_set_acl,
 	.getattr		= xfs_vn_getattr,