xfs: make xfs_cross_rename() complete fully

Now that xfs_finish_rename() exists, there is no reason for
xfs_cross_rename() to return to xfs_rename() to finish off the
rename transaction. Drive the completion code into
xfs_cross_rename() and handle all errors there so as to simplify
the xfs_rename() code.

Further, push the rename exchange target_ip check to early in the
rename code so as to make the error handling easy and obviously
correct.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 21 insertions, 20 deletions

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index c3fe00cb19e4..b376ebe5fad9 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -2703,14 +2703,14 @@ xfs_cross_rename(
                                 ip2->i_ino,
                                 first_block, free_list, spaceres);
         if (error)
-                goto out;
+                goto out_trans_abort;
 
         /* 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;
+                goto out_trans_abort;
 
         /*
          * If we're renaming one or more directories across different parents,
@@ -2725,16 +2725,16 @@ xfs_cross_rename(
                                                 dp1->i_ino, first_block,
                                                 free_list, spaceres);
                         if (error)
-                                goto out;
+                                goto out_trans_abort;
 
                         /* transfer ip2 ".." reference to dp1 */
                         if (!S_ISDIR(ip1->i_d.di_mode)) {
                                 error = xfs_droplink(tp, dp2);
                                 if (error)
-                                        goto out;
+                                        goto out_trans_abort;
                                 error = xfs_bumplink(tp, dp1);
                                 if (error)
-                                        goto out;
+                                        goto out_trans_abort;
                         }
 
                         /*
@@ -2752,16 +2752,16 @@ xfs_cross_rename(
                                                 dp2->i_ino, first_block,
                                                 free_list, spaceres);
                         if (error)
-                                goto out;
+                                goto out_trans_abort;
 
                         /* transfer ip1 ".." reference to dp2 */
                         if (!S_ISDIR(ip2->i_d.di_mode)) {
                                 error = xfs_droplink(tp, dp1);
                                 if (error)
-                                        goto out;
+                                        goto out_trans_abort;
                                 error = xfs_bumplink(tp, dp2);
                                 if (error)
-                                        goto out;
+                                        goto out_trans_abort;
                         }
 
                         /*
@@ -2789,7 +2789,11 @@ xfs_cross_rename(
         }
         xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
         xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE);
-out:
+        return xfs_finish_rename(tp, free_list);
+
+out_trans_abort:
+        xfs_bmap_cancel(free_list);
+        xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES|XFS_TRANS_ABORT);
         return error;
 }
 
@@ -2820,6 +2824,9 @@ xfs_rename(
 
         trace_xfs_rename(src_dp, target_dp, src_name, target_name);
 
+        if ((flags & RENAME_EXCHANGE) && !target_ip)
+                return -EINVAL;
+
         new_parent = (src_dp != target_dp);
         src_is_directory = S_ISDIR(src_ip->i_d.di_mode);
 
@@ -2877,17 +2884,11 @@ xfs_rename(
 
         xfs_bmap_init(&free_list, &first_block);
 
-        /*
-         * 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 out_trans_abort;
-                return xfs_finish_rename(tp, &free_list);
-        }
+        /* RENAME_EXCHANGE is unique from here on. */
+        if (flags & RENAME_EXCHANGE)
+                return xfs_cross_rename(tp, src_dp, src_name, src_ip,
+                                        target_dp, target_name, target_ip,
+                                        &free_list, &first_block, spaceres);
 
         /*
          * Set up the target.