md/raid1: convert to use bio_submit_split_bioset()

Unify bio split code, and prepare to fix ordering of split IO.

Noted that bio_submit_split_bioset() can fail the original bio directly
by split error, set R1BIO_Returned in this case to notify raid_end_bio_io()
that the original bio is returned already.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 64a1e0b47e87043fbee3fe797f35a753118ecf86..3f4ed2272ac42299e9cf6834665e9e9069b5b281 100644 (file)
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1317,7 +1317,7 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
        struct raid1_info *mirror;
        struct bio *read_bio;
        int max_sectors;
-       int rdisk, error;
+       int rdisk;
        bool r1bio_existed = !!r1_bio;
 
        /*
@@ -1377,18 +1377,13 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
        }
 
        if (max_sectors < bio_sectors(bio)) {
-               struct bio *split = bio_split(bio, max_sectors,
-                                             gfp, &conf->bio_split);
-
-               if (IS_ERR(split)) {
-                       error = PTR_ERR(split);
+               bio = bio_submit_split_bioset(bio, max_sectors,
+                                             &conf->bio_split);
+               if (!bio) {
+                       set_bit(R1BIO_Returned, &r1_bio->state);
                        goto err_handle;
                }
 
-               bio_chain(split, bio);
-               trace_block_split(split, bio->bi_iter.bi_sector);
-               submit_bio_noacct(bio);
-               bio = split;
                r1_bio->master_bio = bio;
                r1_bio->sectors = max_sectors;
        }
@@ -1416,8 +1411,6 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
 
 err_handle:
        atomic_dec(&mirror->rdev->nr_pending);
-       bio->bi_status = errno_to_blk_status(error);
-       set_bit(R1BIO_Uptodate, &r1_bio->state);
        raid_end_bio_io(r1_bio);
 }
 
@@ -1484,7 +1477,7 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
 {
        struct r1conf *conf = mddev->private;
        struct r1bio *r1_bio;
-       int i, disks, k, error;
+       int i, disks, k;
        unsigned long flags;
        int first_clone;
        int max_sectors;
@@ -1588,10 +1581,8 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
                                 * complexity of supporting that is not worth
                                 * the benefit.
                                 */
-                               if (bio->bi_opf & REQ_ATOMIC) {
-                                       error = -EIO;
+                               if (bio->bi_opf & REQ_ATOMIC)
                                        goto err_handle;
-                               }
 
                                good_sectors = first_bad - r1_bio->sector;
                                if (good_sectors < max_sectors)
@@ -1611,18 +1602,13 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
                max_sectors = min_t(int, max_sectors,
                                    BIO_MAX_VECS * (PAGE_SIZE >> 9));
        if (max_sectors < bio_sectors(bio)) {
-               struct bio *split = bio_split(bio, max_sectors,
-                                             GFP_NOIO, &conf->bio_split);
-
-               if (IS_ERR(split)) {
-                       error = PTR_ERR(split);
+               bio = bio_submit_split_bioset(bio, max_sectors,
+                                             &conf->bio_split);
+               if (!bio) {
+                       set_bit(R1BIO_Returned, &r1_bio->state);
                        goto err_handle;
                }
 
-               bio_chain(split, bio);
-               trace_block_split(split, bio->bi_iter.bi_sector);
-               submit_bio_noacct(bio);
-               bio = split;
                r1_bio->master_bio = bio;
                r1_bio->sectors = max_sectors;
        }
@@ -1698,8 +1684,6 @@ err_handle:
                }
        }
 
-       bio->bi_status = errno_to_blk_status(error);
-       set_bit(R1BIO_Uptodate, &r1_bio->state);
        raid_end_bio_io(r1_bio);
 }
 

diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h
index d236ef179cfba0a301594a0ab52c7f7ff54937c2..2ebe35aaa534312e03a0d351185f440466febc23 100644 (file)
--- a/drivers/md/raid1.h
+++ b/drivers/md/raid1.h
@@ -178,7 +178,9 @@ enum r1bio_state {
  * any write was successful.  Otherwise we call when
  * any write-behind write succeeds, otherwise we call
  * with failure when last write completes (and all failed).
- * Record that bi_end_io was called with this flag...
+ *
+ * And for bio_split errors, record that bi_end_io was called
+ * with this flag...
  */
        R1BIO_Returned,
 /* If a write for this request means we can clear some