xfs: Ensure we have target_ip for RENAME_EXCHANGE

We shouldn't get here with RENAME_EXCHANGE set and no
target_ip, but let's be defensive, because xfs_cross_rename()
will dereference it.

Spotted by Coverity.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index daafa1f..6163767 100644 (file)
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -2867,6 +2867,10 @@ xfs_rename(
         * Handle RENAME_EXCHANGE flags
         */
        if (flags & RENAME_EXCHANGE) {
+               if (target_ip == NULL) {
+                       error = -EINVAL;
+                       goto error_return;
+               }
                error = xfs_cross_rename(tp, src_dp, src_name, src_ip,
                                         target_dp, target_name, target_ip,
                                         &free_list, &first_block, spaceres);