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| author | Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com> | 2016-11-30 12:28:59 -0800 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2016-12-01 07:58:40 -0700 |
| commit | a6f0788ec2881ac14e97ff7fa6a78a807f87b5ba (patch) | |
| tree | 493bf4be078a224b84c405220965e7a6c00a505c /block/blk-wbt.c | |
| parent | e73c23ff736e1ea371dfa419d7bf8e77ee53044a (diff) | |
| download | lwn-a6f0788ec2881ac14e97ff7fa6a78a807f87b5ba.tar.gz lwn-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-wbt.c')
| -rw-r--r-- | block/blk-wbt.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/block/blk-wbt.c b/block/blk-wbt.c index b8647343141f..d500e43da5d9 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -575,9 +575,10 @@ static inline bool wbt_should_throttle(struct rq_wb *rwb, struct bio *bio) const int op = bio_op(bio); /* - * If not a WRITE (or a discard), do nothing + * If not a WRITE (or a discard or write zeroes), do nothing */ - if (!(op == REQ_OP_WRITE || op == REQ_OP_DISCARD)) + if (!(op == REQ_OP_WRITE || op == REQ_OP_DISCARD || + op == REQ_OP_WRITE_ZEROES)) return false; /* |