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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-sysfs.c | |
| parent | e73c23ff736e1ea371dfa419d7bf8e77ee53044a (diff) | |
| download | linux-a6f0788ec2881ac14e97ff7fa6a78a807f87b5ba.tar.bz2 | |
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-sysfs.c')
| -rw-r--r-- | block/blk-sysfs.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index a97841491769..706b27bd73a1 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -211,6 +211,11 @@ static ssize_t queue_write_same_max_show(struct request_queue *q, char *page) (unsigned long long)q->limits.max_write_same_sectors << 9); } +static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page) +{ + return sprintf(page, "%llu\n", + (unsigned long long)q->limits.max_write_zeroes_sectors << 9); +} static ssize_t queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) @@ -611,6 +616,11 @@ static struct queue_sysfs_entry queue_write_same_max_entry = { .show = queue_write_same_max_show, }; +static struct queue_sysfs_entry queue_write_zeroes_max_entry = { + .attr = {.name = "write_zeroes_max_bytes", .mode = S_IRUGO }, + .show = queue_write_zeroes_max_show, +}; + static struct queue_sysfs_entry queue_nonrot_entry = { .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR }, .show = queue_show_nonrot, @@ -700,6 +710,7 @@ static struct attribute *default_attrs[] = { &queue_discard_max_hw_entry.attr, &queue_discard_zeroes_data_entry.attr, &queue_write_same_max_entry.attr, + &queue_write_zeroes_max_entry.attr, &queue_nonrot_entry.attr, &queue_zoned_entry.attr, &queue_nomerges_entry.attr, |