md: raid10: refactor code of read reshape's .bi_end_io

reshape read request is a bit special and requires one extra
bio which isn't allocated from r10buf_pool.

Refactor the .bi_end_io for read reshape, so that we can use
raid10's resync page mangement approach easily in the following
patches.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 301e73f..94f5c36 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1889,17 +1889,9 @@ abort:
        return err;
 }
 
-static void end_sync_read(struct bio *bio)
+static void __end_sync_read(struct r10bio *r10_bio, struct bio *bio, int d)
 {
-       struct r10bio *r10_bio = bio->bi_private;
        struct r10conf *conf = r10_bio->mddev->private;
-       int d;
-
-       if (bio == r10_bio->master_bio) {
-               /* this is a reshape read */
-               d = r10_bio->read_slot; /* really the read dev */
-       } else
-               d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);
 
        if (!bio->bi_error)
                set_bit(R10BIO_Uptodate, &r10_bio->state);
@@ -1923,6 +1915,22 @@ static void end_sync_read(struct bio *bio)
        }
 }
 
+static void end_sync_read(struct bio *bio)
+{
+       struct r10bio *r10_bio = bio->bi_private;
+       struct r10conf *conf = r10_bio->mddev->private;
+       int d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);
+
+       __end_sync_read(r10_bio, bio, d);
+}
+
+static void end_reshape_read(struct bio *bio)
+{
+       struct r10bio *r10_bio = bio->bi_private;
+
+       __end_sync_read(r10_bio, bio, r10_bio->read_slot);
+}
+
 static void end_sync_request(struct r10bio *r10_bio)
 {
        struct mddev *mddev = r10_bio->mddev;
@@ -4438,7 +4446,7 @@ read_more:
        read_bio->bi_iter.bi_sector = (r10_bio->devs[r10_bio->read_slot].addr
                               + rdev->data_offset);
        read_bio->bi_private = r10_bio;
-       read_bio->bi_end_io = end_sync_read;
+       read_bio->bi_end_io = end_reshape_read;
        bio_set_op_attrs(read_bio, REQ_OP_READ, 0);
        read_bio->bi_flags &= (~0UL << BIO_RESET_BITS);
        read_bio->bi_error = 0;