Commit 212e7eb7 authored by NeilBrown's avatar NeilBrown Committed by Shaohua Li
Browse files

md/raid1: add failfast handling for writes. 



When writing to a fastfail device we use MD_FASTFAIL unless
it is the only device being written to.

For resync/recovery, assume there was a working device to
read from so always use REQ_FASTFAIL_DEV.

If a write for resync/recovery fails, we just fail the
device - there is not much else to do.

If a normal failfast write fails, but the device cannot be
failed (must be only one left), we queue for write error
handling.  This will call narrow_write_error() to retry the
write synchronously and without any FAILFAST flags.

Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent 2e52d449

drivers/md/raid1.c

+25 −1
Original line number Diff line number Diff line
@@ -422,6 +422,23 @@ static void raid1_end_write_request(struct bio *bio) 
			set_bit(MD_RECOVERY_NEEDED, &

				conf->mddev->recovery);



		if (test_bit(FailFast, &rdev->flags) &&

		    (bio->bi_opf & MD_FAILFAST) &&

		    /* We never try FailFast to WriteMostly devices */

		    !test_bit(WriteMostly, &rdev->flags)) {

			md_error(r1_bio->mddev, rdev);

			if (!test_bit(Faulty, &rdev->flags))

				/* This is the only remaining device,

				 * We need to retry the write without

				 * FailFast

				 */

				set_bit(R1BIO_WriteError, &r1_bio->state);

			else {

				/* Finished with this branch */

				r1_bio->bios[mirror] = NULL;

				to_put = bio;

			}

		} else

			set_bit(R1BIO_WriteError, &r1_bio->state);

	} else {

		/*
@@ -1392,6 +1409,10 @@ read_again: 
		mbio->bi_bdev = conf->mirrors[i].rdev->bdev;

		mbio->bi_end_io	= raid1_end_write_request;

		bio_set_op_attrs(mbio, op, do_flush_fua | do_sync);

		if (test_bit(FailFast, &conf->mirrors[i].rdev->flags) &&

		    !test_bit(WriteMostly, &conf->mirrors[i].rdev->flags) &&

		    conf->raid_disks - mddev->degraded > 1)

			mbio->bi_opf |= MD_FAILFAST;

		mbio->bi_private = r1_bio;



		atomic_inc(&r1_bio->remaining);
@@ -2060,6 +2081,9 @@ static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio) 
			continue;



		bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);

		if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))

			wbio->bi_opf |= MD_FAILFAST;



		wbio->bi_end_io = end_sync_write;

		atomic_inc(&r1_bio->remaining);

		md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));

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