From: Keith Busch <kbusch@xxxxxxxxxx>
Now that user space applications can make use of partial sector reads,
export and document the queue attribute that indicates if the capability
is supported.
Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
---
Documentation/ABI/stable/sysfs-block | 9 +++++++++
block/blk-sysfs.c | 3 +++
2 files changed, 12 insertions(+)
diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block
index cd14ecb3c9a5..defc056690d0 100644
--- a/Documentation/ABI/stable/sysfs-block
+++ b/Documentation/ABI/stable/sysfs-block
@@ -142,6 +142,15 @@ Description:
Default value of this file is '1'(on).
+What: /sys/block/<disk>/queue/bit_bucket
+Date: June 2022
+Contact: linux-block@xxxxxxxxxxxxxxx
+Description:
+ [RO] This file indicates if the device supports partial sector
+ reads. If set to '1', user space can issue direct IO reads at
+ dma_alignment granularity.
+
+
What: /sys/block/<disk>/queue/chunk_sectors
Date: September 2016
Contact: Hannes Reinecke <hare@xxxxxxxx>
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 85ea43eff094..0c1f1c2fbb30 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -309,6 +309,7 @@ QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
QUEUE_SYSFS_BIT_FNS(stable_writes, STABLE_WRITES, 0);
+QUEUE_SYSFS_BIT_FNS(bit_bucket, BIT_BUCKET, 0);
#undef QUEUE_SYSFS_BIT_FNS
static ssize_t queue_zoned_show(struct request_queue *q, char *page)
@@ -627,6 +628,7 @@ QUEUE_RW_ENTRY(queue_nonrot, "rotational");
QUEUE_RW_ENTRY(queue_iostats, "iostats");
QUEUE_RW_ENTRY(queue_random, "add_random");
QUEUE_RW_ENTRY(queue_stable_writes, "stable_writes");
+QUEUE_RW_ENTRY(queue_bit_bucket, "bit_bucket");
static struct attribute *queue_attrs[] = {
&queue_requests_entry.attr,
@@ -653,6 +655,7 @@ static struct attribute *queue_attrs[] = {
&queue_zone_append_max_entry.attr,
&queue_zone_write_granularity_entry.attr,
&queue_nonrot_entry.attr,
+ &queue_bit_bucket_entry.attr,
&queue_zoned_entry.attr,
&queue_nr_zones_entry.attr,
&queue_max_open_zones_entry.attr,
--
2.30.2
