Commit 7399c31b authored by NeilBrown's avatar NeilBrown
Browse files

md/raid10: avoid reading from known bad blocks - part 2 



When redirecting a read error to a different device, we must
again avoid bad blocks and possibly split the request.

Spin_lock typo fixed thanks to Dan Carpenter <error27@gmail.com>

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 856e08e2

drivers/md/raid10.c

+40 −5
Original line number Diff line number Diff line
@@ -1746,14 +1746,15 @@ static void handle_read_error(mddev_t *mddev, r10bio_t *r10_bio) 
	rdev_dec_pending(conf->mirrors[mirror].rdev, mddev);



	bio = r10_bio->devs[slot].bio;

	bdevname(bio->bi_bdev, b);

	r10_bio->devs[slot].bio =

		mddev->ro ? IO_BLOCKED : NULL;

read_more:

	mirror = read_balance(conf, r10_bio, &max_sectors);

	if (mirror == -1 || max_sectors < r10_bio->sectors) {

	if (mirror == -1) {

		printk(KERN_ALERT "md/raid10:%s: %s: unrecoverable I/O"

		       " read error for block %llu\n",

		       mdname(mddev),

		       bdevname(bio->bi_bdev, b),

		       mdname(mddev), b,

		       (unsigned long long)r10_bio->sector);

		raid_end_bio_io(r10_bio);

		bio_put(bio);
@@ -1761,6 +1762,7 @@ static void handle_read_error(mddev_t *mddev, r10bio_t *r10_bio) 
	}



	do_sync = (r10_bio->master_bio->bi_rw & REQ_SYNC);

	if (bio)

		bio_put(bio);

	slot = r10_bio->read_slot;

	rdev = conf->mirrors[mirror].rdev;
@@ -1773,6 +1775,9 @@ static void handle_read_error(mddev_t *mddev, r10bio_t *r10_bio) 
		(unsigned long long)r10_bio->sector);

	bio = bio_clone_mddev(r10_bio->master_bio,

			      GFP_NOIO, mddev);

	md_trim_bio(bio,

		    r10_bio->sector - bio->bi_sector,

		    max_sectors);

	r10_bio->devs[slot].bio = bio;

	bio->bi_sector = r10_bio->devs[slot].addr

		+ rdev->data_offset;
@@ -1780,6 +1785,36 @@ static void handle_read_error(mddev_t *mddev, r10bio_t *r10_bio) 
	bio->bi_rw = READ | do_sync;

	bio->bi_private = r10_bio;

	bio->bi_end_io = raid10_end_read_request;

	if (max_sectors < r10_bio->sectors) {

		/* Drat - have to split this up more */

		struct bio *mbio = r10_bio->master_bio;

		int sectors_handled =

			r10_bio->sector + max_sectors

			- mbio->bi_sector;

		r10_bio->sectors = max_sectors;

		spin_lock_irq(&conf->device_lock);

		if (mbio->bi_phys_segments == 0)

			mbio->bi_phys_segments = 2;

		else

			mbio->bi_phys_segments++;

		spin_unlock_irq(&conf->device_lock);

		generic_make_request(bio);

		bio = NULL;



		r10_bio = mempool_alloc(conf->r10bio_pool,

					GFP_NOIO);

		r10_bio->master_bio = mbio;

		r10_bio->sectors = (mbio->bi_size >> 9)

			- sectors_handled;

		r10_bio->state = 0;

		set_bit(R10BIO_ReadError,

			&r10_bio->state);

		r10_bio->mddev = mddev;

		r10_bio->sector = mbio->bi_sector

			+ sectors_handled;



		goto read_more;

	} else

		generic_make_request(bio);

}