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| author |   Ilya Dryomov <idryomov@gmail.com> | 2017-05-22 19:59:24 +0200 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2017-05-29 11:18:01 +0200 |
| commit | 6ac56951dc10232e24419f6972fc8131dd0166e0 (patch) | |
| tree | 1a748b97e97439e897b30a26595c5a7872d131be /drivers | |
| parent | Linux 4.12-rc3 (diff) | |
| download | linux-dev-6ac56951dc10232e24419f6972fc8131dd0166e0.tar.xz linux-dev-6ac56951dc10232e24419f6972fc8131dd0166e0.zip | |
rbd: implement REQ_OP_WRITE_ZEROES
Commit 93c1defedcae ("rbd: remove the discard_zeroes_data flag")
explicitly didn't implement REQ_OP_WRITE_ZEROES for rbd, while the
following commit 48920ff2a5a9 ("block: remove the discard_zeroes_data
flag") dropped ->discard_zeroes_data in favor of REQ_OP_WRITE_ZEROES.
rbd does support efficient zeroing via CEPH_OSD_OP_ZERO opcode and will
release either some or all blocks depending on whether the zeroing
request is rbd_obj_bytes() aligned. This is how we currently implement
discards, so REQ_OP_WRITE_ZEROES can be identical to REQ_OP_DISCARD for
now. Caveats:
- REQ_NOUNMAP is ignored, but AFAICT that's true of at least two other
current implementations - nvme and loop
- there is no ->write_zeroes_alignment and blk_bio_write_zeroes_split()
is hence less helpful than blk_bio_discard_split(), but this can (and
should) be fixed on the rbd side
In the future we will split these into two code paths to respect
REQ_NOUNMAP on zeroout and save on zeroing blocks that couldn't be
released on discard.
Fixes: 93c1defedcae ("rbd: remove the discard_zeroes_data flag")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jason Dillaman <dillaman@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/block/rbd.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 454bf9c34882..c16f74547804 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -4023,6 +4023,7 @@ static void rbd_queue_workfn(struct work_struct *work) switch (req_op(rq)) { case REQ_OP_DISCARD: + case REQ_OP_WRITE_ZEROES: op_type = OBJ_OP_DISCARD; break; case REQ_OP_WRITE: @@ -4420,6 +4421,7 @@ static int rbd_init_disk(struct rbd_device *rbd_dev) q->limits.discard_granularity = segment_size; q->limits.discard_alignment = segment_size; blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE); + blk_queue_max_write_zeroes_sectors(q, segment_size / SECTOR_SIZE); if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC)) q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES; |