Merge branch 'urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback

* 'urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback:
  don't busy retry the inode on failed grab_super_passive()

fs/fs-writeback.c

@@ -618,7 +618,12 @@ static long __writeback_inodes_wb(struct bdi_writeback *wb,
 		struct super_block *sb = inode->i_sb;
 
 		if (!grab_super_passive(sb)) {
-			requeue_io(inode, wb);
+			/*
+			 * grab_super_passive() may fail consistently due to
+			 * s_umount being grabbed by someone else. Don't use
+			 * requeue_io() to avoid busy retrying the inode/sb.
+			 */
+			redirty_tail(inode, wb);
 			continue;
 		}
 		wrote += writeback_sb_inodes(sb, wb, work);