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: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
This commit is contained in:
NeilBrown 2016-11-18 16:16:12 +11:00 committed by Shaohua Li
parent 2e52d449bc
commit 212e7eb7a3

View File

@ -422,7 +422,24 @@ static void raid1_end_write_request(struct bio *bio)
set_bit(MD_RECOVERY_NEEDED, &
conf->mddev->recovery);
set_bit(R1BIO_WriteError, &r1_bio->state);
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 {
/*
* Set R1BIO_Uptodate in our master bio, so that we
@ -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));