From 4184153f9e483f9bb63339ed316e059962fe9794 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Thu, 10 Dec 2009 23:51:59 +0000 Subject: dm raid1: support flush Flush support for dm-raid1. When it receives an empty barrier, submit it to all the devices via dm-io. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- drivers/md/dm-region-hash.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) (limited to 'drivers/md/dm-region-hash.c') diff --git a/drivers/md/dm-region-hash.c b/drivers/md/dm-region-hash.c index 36dbe29f2fd..00806b760cc 100644 --- a/drivers/md/dm-region-hash.c +++ b/drivers/md/dm-region-hash.c @@ -79,6 +79,11 @@ struct dm_region_hash { struct list_head recovered_regions; struct list_head failed_recovered_regions; + /* + * If there was a barrier failure no regions can be marked clean. + */ + int barrier_failure; + void *context; sector_t target_begin; @@ -211,6 +216,7 @@ struct dm_region_hash *dm_region_hash_create( INIT_LIST_HEAD(&rh->quiesced_regions); INIT_LIST_HEAD(&rh->recovered_regions); INIT_LIST_HEAD(&rh->failed_recovered_regions); + rh->barrier_failure = 0; rh->region_pool = mempool_create_kmalloc_pool(MIN_REGIONS, sizeof(struct dm_region)); @@ -395,6 +401,11 @@ void dm_rh_mark_nosync(struct dm_region_hash *rh, region_t region = dm_rh_bio_to_region(rh, bio); int recovering = 0; + if (bio_empty_barrier(bio)) { + rh->barrier_failure = 1; + return; + } + /* We must inform the log that the sync count has changed. */ log->type->set_region_sync(log, region, 0); @@ -515,8 +526,11 @@ void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios) { struct bio *bio; - for (bio = bios->head; bio; bio = bio->bi_next) + for (bio = bios->head; bio; bio = bio->bi_next) { + if (bio_empty_barrier(bio)) + continue; rh_inc(rh, dm_rh_bio_to_region(rh, bio)); + } } EXPORT_SYMBOL_GPL(dm_rh_inc_pending); @@ -544,7 +558,14 @@ void dm_rh_dec(struct dm_region_hash *rh, region_t region) */ /* do nothing for DM_RH_NOSYNC */ - if (reg->state == DM_RH_RECOVERING) { + if (unlikely(rh->barrier_failure)) { + /* + * If a write barrier failed some time ago, we + * don't know whether or not this write made it + * to the disk, so we must resync the device. + */ + reg->state = DM_RH_NOSYNC; + } else if (reg->state == DM_RH_RECOVERING) { list_add_tail(®->list, &rh->quiesced_regions); } else if (reg->state == DM_RH_DIRTY) { reg->state = DM_RH_CLEAN; -- cgit v1.2.3-70-g09d2