From 1919cbb23bf1b3e0fdb7b6edfb7369f920744087 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Fri, 18 Nov 2016 16:16:12 +1100 Subject: [PATCH] md/raid10: 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 MD_FASTFAIL. If a write for resync/recovery fails, we just fail the device - there is not much else to do. If a normal write fails, but the device cannot be marked Faulty (must be only one left), we queue for write error handling which calls narrow_write_error() to write the block synchronously without any failfast flags. Signed-off-by: NeilBrown Signed-off-by: Shaohua Li --- drivers/md/raid10.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 7cdc9bcd21b0..525ca9923707 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -100,6 +100,7 @@ static int max_queued_requests = 1024; static void allow_barrier(struct r10conf *conf); static void lower_barrier(struct r10conf *conf); static int _enough(struct r10conf *conf, int previous, int ignore); +static int enough(struct r10conf *conf, int ignore); static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *skipped); static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio); @@ -450,6 +451,7 @@ static void raid10_end_write_request(struct bio *bio) struct r10conf *conf = r10_bio->mddev->private; int slot, repl; struct md_rdev *rdev = NULL; + struct bio *to_put = NULL; bool discard_error; discard_error = bio->bi_error && bio_op(bio) == REQ_OP_DISCARD; @@ -477,8 +479,24 @@ static void raid10_end_write_request(struct bio *bio) if (!test_and_set_bit(WantReplacement, &rdev->flags)) set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery); - set_bit(R10BIO_WriteError, &r10_bio->state); + dec_rdev = 0; + if (test_bit(FailFast, &rdev->flags) && + (bio->bi_opf & MD_FAILFAST)) { + md_error(rdev->mddev, rdev); + if (!test_bit(Faulty, &rdev->flags)) + /* This is the only remaining device, + * We need to retry the write without + * FailFast + */ + set_bit(R10BIO_WriteError, &r10_bio->state); + else { + r10_bio->devs[slot].bio = NULL; + to_put = bio; + dec_rdev = 1; + } + } else + set_bit(R10BIO_WriteError, &r10_bio->state); } } else { /* @@ -528,6 +546,8 @@ static void raid10_end_write_request(struct bio *bio) one_write_done(r10_bio); if (dec_rdev) rdev_dec_pending(rdev, conf->mddev); + if (to_put) + bio_put(to_put); } /* @@ -1390,6 +1410,9 @@ static void __make_request(struct mddev *mddev, struct bio *bio) mbio->bi_bdev = rdev->bdev; mbio->bi_end_io = raid10_end_write_request; bio_set_op_attrs(mbio, op, do_sync | do_fua); + if (test_bit(FailFast, &conf->mirrors[d].rdev->flags) && + enough(conf, d)) + mbio->bi_opf |= MD_FAILFAST; mbio->bi_private = r10_bio; if (conf->mddev->gendisk) @@ -2052,6 +2075,8 @@ static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio) atomic_inc(&r10_bio->remaining); md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(tbio)); + if (test_bit(FailFast, &conf->mirrors[d].rdev->flags)) + tbio->bi_opf |= MD_FAILFAST; tbio->bi_iter.bi_sector += conf->mirrors[d].rdev->data_offset; tbio->bi_bdev = conf->mirrors[d].rdev->bdev; generic_make_request(tbio); @@ -3341,6 +3366,8 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, bio->bi_private = r10_bio; bio->bi_end_io = end_sync_write; bio_set_op_attrs(bio, REQ_OP_WRITE, 0); + if (test_bit(FailFast, &conf->mirrors[d].rdev->flags)) + bio->bi_opf |= MD_FAILFAST; bio->bi_iter.bi_sector = sector + rdev->data_offset; bio->bi_bdev = rdev->bdev; count++;