Merge tag 'xfs-4.12-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs fixes from Darrick Wong:
 "I have one more bugfix for you for 4.12-rc7 to fix a disk corruption
  problem:

   - don't allow swapon on files on the realtime device, because the
     swap code will swap pages out to blocks on the data device, thereby
     corrupting the filesystem"

* tag 'xfs-4.12-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: don't allow bmap on rt files

fs/xfs/xfs_aops.c

@@ -1316,9 +1316,12 @@ xfs_vm_bmap(
 	 * The swap code (ab-)uses ->bmap to get a block mapping and then
 	 * bypasseѕ the file system for actual I/O.  We really can't allow
 	 * that on reflinks inodes, so we have to skip out here.  And yes,
-	 * 0 is the magic code for a bmap error..
+	 * 0 is the magic code for a bmap error.
+	 *
+	 * Since we don't pass back blockdev info, we can't return bmap
+	 * information for rt files either.
 	 */
-	if (xfs_is_reflink_inode(ip))
+	if (xfs_is_reflink_inode(ip) || XFS_IS_REALTIME_INODE(ip))
 		return 0;
 
 	filemap_write_and_wait(mapping);