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| author | Tejun Heo <tj@kernel.org> | 2010-09-03 11:56:19 +0200 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2010-09-10 12:35:38 +0200 |
| commit | d87f4c14f27dc82d215108d8392a7d26687148a1 (patch) | |
| tree | 55f2a81f3df5d70fd85c4428089f6fe28540bcf4 /drivers/md/dm-region-hash.c | |
| parent | 3a2edd0d6ddbd5fa3b389ea6db811285415ce6c8 (diff) | |
| download | lwn-d87f4c14f27dc82d215108d8392a7d26687148a1.tar.gz lwn-d87f4c14f27dc82d215108d8392a7d26687148a1.zip | |
dm: implement REQ_FLUSH/FUA support for bio-based dm
This patch converts bio-based dm to support REQ_FLUSH/FUA instead of
now deprecated REQ_HARDBARRIER.
* -EOPNOTSUPP handling logic dropped.
* Preflush is handled as before but postflush is dropped and replaced
with passing down REQ_FUA to member request_queues. This replaces
one array wide cache flush w/ member specific FUA writes.
* __split_and_process_bio() now calls __clone_and_map_flush() directly
for flushes and guarantees all FLUSH bio's going to targets are zero
` length.
* It's now guaranteed that all FLUSH bio's which are passed onto dm
targets are zero length. bio_empty_barrier() tests are replaced
with REQ_FLUSH tests.
* Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes.
* Dropped unlikely() around REQ_FLUSH tests. Flushes are not unlikely
enough to be marked with unlikely().
* Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue
doesn't support cache flushing. Advertise REQ_FLUSH | REQ_FUA
capability.
* Request based dm isn't converted yet. dm_init_request_based_queue()
resets flush support to 0 for now. To avoid disturbing request
based dm code, dm->flush_error is added for bio based dm while
requested based dm continues to use dm->barrier_error.
Lightly tested linear, stripe, raid1, snap and crypt targets. Please
proceed with caution as I'm not familiar with the code base.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: dm-devel@redhat.com
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'drivers/md/dm-region-hash.c')
| -rw-r--r-- | drivers/md/dm-region-hash.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/drivers/md/dm-region-hash.c b/drivers/md/dm-region-hash.c index bd5c58b28868..dad011aed0c9 100644 --- a/drivers/md/dm-region-hash.c +++ b/drivers/md/dm-region-hash.c @@ -81,9 +81,9 @@ struct dm_region_hash { struct list_head failed_recovered_regions; /* - * If there was a barrier failure no regions can be marked clean. + * If there was a flush failure no regions can be marked clean. */ - int barrier_failure; + int flush_failure; void *context; sector_t target_begin; @@ -217,7 +217,7 @@ 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->flush_failure = 0; rh->region_pool = mempool_create_kmalloc_pool(MIN_REGIONS, sizeof(struct dm_region)); @@ -399,8 +399,8 @@ void dm_rh_mark_nosync(struct dm_region_hash *rh, struct bio *bio) region_t region = dm_rh_bio_to_region(rh, bio); int recovering = 0; - if (bio_empty_barrier(bio)) { - rh->barrier_failure = 1; + if (bio->bi_rw & REQ_FLUSH) { + rh->flush_failure = 1; return; } @@ -524,7 +524,7 @@ 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) { - if (bio_empty_barrier(bio)) + if (bio->bi_rw & REQ_FLUSH) continue; rh_inc(rh, dm_rh_bio_to_region(rh, bio)); } @@ -555,9 +555,9 @@ void dm_rh_dec(struct dm_region_hash *rh, region_t region) */ /* do nothing for DM_RH_NOSYNC */ - if (unlikely(rh->barrier_failure)) { + if (unlikely(rh->flush_failure)) { /* - * If a write barrier failed some time ago, we + * If a write flush failed some time ago, we * don't know whether or not this write made it * to the disk, so we must resync the device. */ |