[PATCH 04/15] block: use queue_limits_commit_update in queue_max_sectors_store

Christoph Hellwig
2024-01-22T17:37:03Z

Convert queue_max_sectors_store to use queue_limits_commit_update to
check and updated the max_sectors limit and freeze the queue before
doing so to ensure we don't have request in flight while changing
the limits.

Note that this removes the previously held queue_lock that doesn't
protect against any other read or writer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/blk-sysfs.c | 37 ++++++++++++-------------------------
1 file changed, 12 insertions(+), 25 deletions(-)

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 6b2429cad81af1..26607f9825cb05 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -226,35 +226,22 @@ static ssize_t queue_zone_append_max_show(struct request_queue *q, char *page)
static ssize_t
queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
{
- unsigned long var;
- unsigned int max_sectors_kb,
- max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
- page_kb = 1 << (PAGE_SHIFT - 10);
- ssize_t ret = queue_var_store(&var, page, count);
+ unsigned long max_sectors_kb;
+ struct queue_limits lim;
+ ssize_t ret;
+ int err;

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

- max_sectors_kb = (unsigned int)var;
- max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb,
- q->limits.max_dev_sectors >> 1);
- if (max_sectors_kb == 0) {
- q->limits.max_user_sectors = 0;
- max_sectors_kb = min(max_hw_sectors_kb,
- BLK_DEF_MAX_SECTORS_CAP >> 1);
- } else {
- if (max_sectors_kb > max_hw_sectors_kb ||
- max_sectors_kb < page_kb)
- return -EINVAL;
- q->limits.max_user_sectors = max_sectors_kb << 1;
- }
-
- spin_lock_irq(&q->queue_lock);
- q->limits.max_sectors = max_sectors_kb << 1;
- if (q->disk)
- q->disk->bdi->io_pages = max_sectors_kb >> (PAGE_SHIFT - 10);
- spin_unlock_irq(&q->queue_lock);
-
+ blk_mq_freeze_queue(q);
+ lim = queue_limits_start_update(q);
+ lim.max_user_sectors = max_sectors_kb << 1;
+ err = queue_limits_commit_update(q, &lim);
+ blk_mq_unfreeze_queue(q);
+ if (err)
+ return err;
return ret;
}

--
2.39.2