From 12a7cf5ba6c776a2621d8972c7d42e8d3d959d20 Mon Sep 17 00:00:00 2001 From: Heinz Mauelshagen Date: Mon, 10 Oct 2016 18:48:06 +0200 Subject: [PATCH] dm mirror: use all available legs on multiple failures When any leg(s) have failed, any read will cause a new operational default leg to be selected and the read is resubmitted to it. If that new default leg fails the read too, no other still accessible legs are used to resubmit the read again -- thus failing the io. Fix by allowing the read to get resubmitted until all operational legs have been exhausted. Also, remove any details.bi_dev use as a flag. Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer --- drivers/md/dm-raid1.c | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-) diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c index 7a6254d54baf..9a8b71067c6e 100644 --- a/drivers/md/dm-raid1.c +++ b/drivers/md/dm-raid1.c @@ -145,7 +145,6 @@ static void dispatch_bios(void *context, struct bio_list *bio_list) struct dm_raid1_bio_record { struct mirror *m; - /* if details->bi_bdev == NULL, details were not saved */ struct dm_bio_details details; region_t write_region; }; @@ -1200,8 +1199,6 @@ static int mirror_map(struct dm_target *ti, struct bio *bio) struct dm_raid1_bio_record *bio_record = dm_per_bio_data(bio, sizeof(struct dm_raid1_bio_record)); - bio_record->details.bi_bdev = NULL; - if (rw == WRITE) { /* Save region for mirror_end_io() handler */ bio_record->write_region = dm_rh_bio_to_region(ms->rh, bio); @@ -1260,22 +1257,12 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio, int error) } if (error == -EOPNOTSUPP) - goto out; + return error; if ((error == -EWOULDBLOCK) && (bio->bi_opf & REQ_RAHEAD)) - goto out; + return error; if (unlikely(error)) { - if (!bio_record->details.bi_bdev) { - /* - * There wasn't enough memory to record necessary - * information for a retry or there was no other - * mirror in-sync. - */ - DMERR_LIMIT("Mirror read failed."); - return -EIO; - } - m = bio_record->m; DMERR("Mirror read failed from %s. Trying alternative device.", @@ -1291,7 +1278,6 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio, int error) bd = &bio_record->details; dm_bio_restore(bd, bio); - bio_record->details.bi_bdev = NULL; bio->bi_error = 0; queue_bio(ms, bio, rw); @@ -1300,9 +1286,6 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio, int error) DMERR("All replicated volumes dead, failing I/O"); } -out: - bio_record->details.bi_bdev = NULL; - return error; } -- 2.20.1