Btrfs: fix wrong error handle when the device is missing or is not writeable

The original bio might be submitted, so we shoud increase bi_remaining to
account for it when we deal with the error that the device is missing or
is not writeable, or we would skip the endio handle.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/volumes.c

@@ -5359,6 +5359,15 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
 	return 0;
 }
 
+static inline void btrfs_end_bbio(struct btrfs_bio *bbio, struct bio *bio, int err)
+{
+	if (likely(bbio->flags & BTRFS_BIO_ORIG_BIO_SUBMITTED))
+		bio_endio_nodec(bio, err);
+	else
+		bio_endio(bio, err);
+	kfree(bbio);
+}
+
 static void btrfs_end_bio(struct bio *bio, int err)
 {
 	struct btrfs_bio *bbio = bio->bi_private;
@@ -5416,11 +5425,7 @@ static void btrfs_end_bio(struct bio *bio, int err)
 			err = 0;
 		}
 
-		if (likely(bbio->flags & BTRFS_BIO_ORIG_BIO_SUBMITTED))
-			bio_endio_nodec(bio, err);
-		else
-			bio_endio(bio, err);
-		kfree(bbio);
+		btrfs_end_bbio(bbio, bio, err);
 	} else if (!is_orig_bio) {
 		bio_put(bio);
 	}
@@ -5583,12 +5588,15 @@ static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
 {
 	atomic_inc(&bbio->error);
 	if (atomic_dec_and_test(&bbio->stripes_pending)) {
+		/* Shoud be the original bio. */
+		WARN_ON(bio != bbio->orig_bio);
+
 		bio->bi_private = bbio->private;
 		bio->bi_end_io = bbio->end_io;
 		btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
 		bio->bi_iter.bi_sector = logical >> 9;
-		kfree(bbio);
-		bio_endio(bio, -EIO);
+
+		btrfs_end_bbio(bbio, bio, -EIO);
 	}
 }