Commit 6b6c8110 authored by NeilBrown's avatar NeilBrown Committed by Shaohua Li
Browse files

md/raid1, raid10: move rXbio accounting closer to allocation. 



When raid1 or raid10 find they will need to allocate a new
r1bio/r10bio, in order to work around a known bad block, they
account for the allocation well before the allocation is
made.  This separation makes the correctness less obvious
and requires comments.

The accounting needs to be a little before: before the first
rXbio is submitted, but that is all.

So move the accounting down to where it makes more sense.

Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent 97d53438

drivers/md/raid1.c

+11 −13
Original line number Diff line number Diff line
@@ -1436,18 +1436,9 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio) 
		goto retry_write;

	}



	if (max_sectors < r1_bio->sectors) {

		/* We are splitting this write into multiple parts, so

		 * we need to prepare for allocating another r1_bio.

		 */

	if (max_sectors < r1_bio->sectors)

		r1_bio->sectors = max_sectors;

		spin_lock_irq(&conf->device_lock);

		if (bio->bi_phys_segments == 0)

			bio->bi_phys_segments = 2;

		else

			bio->bi_phys_segments++;

		spin_unlock_irq(&conf->device_lock);

	}



	sectors_handled = r1_bio->sector + max_sectors - bio->bi_iter.bi_sector;



	atomic_set(&r1_bio->remaining, 1);
@@ -1553,10 +1544,17 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio) 
	 * as it could result in the bio being freed.

	 */

	if (sectors_handled < bio_sectors(bio)) {

		r1_bio_write_done(r1_bio);

		/* We need another r1_bio.  It has already been counted

		/* We need another r1_bio, which must be accounted

		 * in bio->bi_phys_segments

		 */

		spin_lock_irq(&conf->device_lock);

		if (bio->bi_phys_segments == 0)

			bio->bi_phys_segments = 2;

		else

			bio->bi_phys_segments++;

		spin_unlock_irq(&conf->device_lock);



		r1_bio_write_done(r1_bio);

		r1_bio = alloc_r1bio(mddev, bio, sectors_handled);

		goto retry_write;

	}

drivers/md/raid10.c

+9 −13
Original line number Diff line number Diff line
@@ -1384,18 +1384,8 @@ retry_write: 
		goto retry_write;

	}



	if (max_sectors < r10_bio->sectors) {

		/* We are splitting this into multiple parts, so

		 * we need to prepare for allocating another r10_bio.

		 */

	if (max_sectors < r10_bio->sectors)

		r10_bio->sectors = max_sectors;

		spin_lock_irq(&conf->device_lock);

		if (bio->bi_phys_segments == 0)

			bio->bi_phys_segments = 2;

		else

			bio->bi_phys_segments++;

		spin_unlock_irq(&conf->device_lock);

	}

	sectors_handled = r10_bio->sector + max_sectors -

		bio->bi_iter.bi_sector;
@@ -1505,10 +1495,16 @@ retry_write: 
	 */



	if (sectors_handled < bio_sectors(bio)) {

		one_write_done(r10_bio);

		/* We need another r10_bio.  It has already been counted

		/* We need another r10_bio and it needs to be counted

		 * in bio->bi_phys_segments.

		 */

		spin_lock_irq(&conf->device_lock);

		if (bio->bi_phys_segments == 0)

			bio->bi_phys_segments = 2;

		else

			bio->bi_phys_segments++;

		spin_unlock_irq(&conf->device_lock);

		one_write_done(r10_bio);

		r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);



		r10_bio->master_bio = bio;

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