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| author | Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com> | 2016-11-30 21:28:59 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2016-12-01 15:58:40 +0100 |
| commit | a6f0788ec2881ac14e97ff7fa6a78a807f87b5ba (patch) | |
| tree | 493bf4be078a224b84c405220965e7a6c00a505c /block/blk-merge.c | |
| parent | block: add async variant of blkdev_issue_zeroout (diff) | |
| download | linux-a6f0788ec2881ac14e97ff7fa6a78a807f87b5ba.tar.xz linux-a6f0788ec2881ac14e97ff7fa6a78a807f87b5ba.zip | |
block: add support for REQ_OP_WRITE_ZEROES
This adds a new block layer operation to zero out a range of
LBAs. This allows to implement zeroing for devices that don't use
either discard with a predictable zero pattern or WRITE SAME of zeroes.
The prominent example of that is NVMe with the Write Zeroes command,
but in the future, this should also help with improving the way
zeroing discards work. For this operation, suitable entry is exported in
sysfs which indicate the number of maximum bytes allowed in one
write zeroes operation by the device.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-merge.c')
| -rw-r--r-- | block/blk-merge.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index fda6a12fc776..cf2848cb91d8 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -199,6 +199,10 @@ void blk_queue_split(struct request_queue *q, struct bio **bio, case REQ_OP_SECURE_ERASE: split = blk_bio_discard_split(q, *bio, bs, &nsegs); break; + case REQ_OP_WRITE_ZEROES: + split = NULL; + nsegs = (*bio)->bi_phys_segments; + break; case REQ_OP_WRITE_SAME: split = blk_bio_write_same_split(q, *bio, bs, &nsegs); break; @@ -241,11 +245,15 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, * This should probably be returning 0, but blk_add_request_payload() * (Christoph!!!!) */ - if (bio_op(bio) == REQ_OP_DISCARD || bio_op(bio) == REQ_OP_SECURE_ERASE) - return 1; - - if (bio_op(bio) == REQ_OP_WRITE_SAME) + switch (bio_op(bio)) { + case REQ_OP_DISCARD: + case REQ_OP_SECURE_ERASE: + case REQ_OP_WRITE_SAME: + case REQ_OP_WRITE_ZEROES: return 1; + default: + break; + } fbio = bio; cluster = blk_queue_cluster(q); @@ -416,6 +424,7 @@ static int __blk_bios_map_sg(struct request_queue *q, struct bio *bio, switch (bio_op(bio)) { case REQ_OP_DISCARD: case REQ_OP_SECURE_ERASE: + case REQ_OP_WRITE_ZEROES: /* * This is a hack - drivers should be neither modifying the * biovec, nor relying on bi_vcnt - but because of |