[PATCH 05/15] block: add a max_user_discard_sectors queue limit

Christoph Hellwig
2024-01-22T17:37:05Z

Add a new max_user_discard_sectors limit that mirrors max_user_sectors
and stores the value that the user manually set. This now allows
updates of the max_hw_discard_sectors to not worry about the user
limit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/blk-settings.c | 13 ++++++++++---
block/blk-sysfs.c | 18 +++++++++---------
include/linux/blkdev.h | 1 +
3 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/block/blk-settings.c b/block/blk-settings.c
index b6692143ccf034..f58da0810a00f2 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -47,6 +47,7 @@ void blk_set_default_limits(struct queue_limits *lim)
lim->max_zone_append_sectors = 0;
lim->max_discard_sectors = 0;
lim->max_hw_discard_sectors = 0;
+ lim->max_user_discard_sectors = 0;
lim->max_secure_erase_sectors = 0;
lim->discard_granularity = 512;
lim->discard_alignment = 0;
@@ -167,7 +168,10 @@ int blk_validate_limits(struct queue_limits *lim)
if (!lim->max_segments)
lim->max_segments = BLK_MAX_SEGMENTS;

- lim->max_discard_sectors = lim->max_hw_discard_sectors;
+ lim->max_discard_sectors =
+ min_not_zero(lim->max_hw_discard_sectors,
+ lim->max_user_discard_sectors);
+
if (!lim->max_discard_segments)
lim->max_discard_segments = 1;

@@ -328,8 +332,11 @@ EXPORT_SYMBOL(blk_queue_chunk_sectors);
void blk_queue_max_discard_sectors(struct request_queue *q,
unsigned int max_discard_sectors)
{
- q->limits.max_hw_discard_sectors = max_discard_sectors;
- q->limits.max_discard_sectors = max_discard_sectors;
+ struct queue_limits *lim = &q->limits;
+
+ lim->max_hw_discard_sectors = max_discard_sectors;
+ lim->max_discard_sectors = min_not_zero(max_discard_sectors,
+ lim->max_user_discard_sectors);
}
EXPORT_SYMBOL(blk_queue_max_discard_sectors);

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 26607f9825cb05..54e10604ddb1dd 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -174,23 +174,23 @@ static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
static ssize_t queue_discard_max_store(struct request_queue *q,
const char *page, size_t count)
{
- unsigned long max_discard;
- ssize_t ret = queue_var_store(&max_discard, page, count);
+ unsigned long max_discard_bytes;
+ ssize_t ret;

+ ret = queue_var_store(&max_discard_bytes, page, count);
if (ret < 0)
return ret;

- if (max_discard & (q->limits.discard_granularity - 1))
+ if (max_discard_bytes & (q->limits.discard_granularity - 1))
return -EINVAL;

- max_discard >>= 9;
- if (max_discard > UINT_MAX)
+ if ((max_discard_bytes >> SECTOR_SHIFT) > UINT_MAX)
return -EINVAL;

- if (max_discard > q->limits.max_hw_discard_sectors)
- max_discard = q->limits.max_hw_discard_sectors;
-
- q->limits.max_discard_sectors = max_discard;
+ q->limits.max_user_discard_sectors = max_discard_bytes >> SECTOR_SHIFT;
+ q->limits.max_discard_sectors =
+ min_not_zero(q->limits.max_hw_discard_sectors,
+ q->limits.max_user_discard_sectors);
return ret;
}

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 5b5d3b238de1e7..700ec5055b668d 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -290,6 +290,7 @@ struct queue_limits {
unsigned int io_opt;
unsigned int max_discard_sectors;
unsigned int max_hw_discard_sectors;
+ unsigned int max_user_discard_sectors;
unsigned int max_secure_erase_sectors;
unsigned int max_write_zeroes_sectors;
unsigned int max_zone_append_sectors;
--
2.39.2