summaryrefslogtreecommitdiffstats
path: root/block/blk-sysfs.c
diff options
context:
space:
mode:
authorChaitanya Kulkarni <chaitanya.kulkarni@hgst.com>2016-11-30 12:28:59 -0800
committerJens Axboe <axboe@fb.com>2016-12-01 07:58:40 -0700
commita6f0788ec2881ac14e97ff7fa6a78a807f87b5ba (patch)
tree493bf4be078a224b84c405220965e7a6c00a505c /block/blk-sysfs.c
parente73c23ff736e1ea371dfa419d7bf8e77ee53044a (diff)
downloadlinux-0-day-a6f0788ec2881ac14e97ff7fa6a78a807f87b5ba.tar.gz
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.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index a978414..706b27b 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,