If the current io scheduler is 'none', the max allowed 'nr_requests'
should be from set->queue_depth, instead of the tags's depth, which
can be adjusted before.
This patch fixes this issue by using set->queue_depth as the max
allowed 'nr_requests', meantime updating q->nr_requests when switching
to 'none' scheduler.
Cc: Marco Patalano <mpatalan@xxxxxxxxxx>
Cc: "Ewan D. Milne" <emilne@xxxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
This issue can be reproduced by the blktests block/021, which will
be posted soon.
block/blk-mq-sched.c | 1 +
block/blk-mq-tag.c | 6 ++++--
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index b0f2c2a40a0c..b087d8884a08 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -585,6 +585,7 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
if (!e) {
q->elevator = NULL;
+ q->nr_requests = q->tag_set->queue_depth;
return 0;
}
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index a4e58fc28a06..a178d862a29a 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -423,7 +423,9 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
struct blk_mq_tags **tagsptr, unsigned int tdepth,
bool can_grow)
{
+ struct blk_mq_tag_set *set = hctx->queue->tag_set;
struct blk_mq_tags *tags = *tagsptr;
+ unsigned int max_depth;
if (tdepth <= tags->nr_reserved_tags)
return -EINVAL;
@@ -434,8 +436,8 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
* If we are allowed to grow beyond the original size, allocate
* a new set of tags before freeing the old one.
*/
- if (tdepth > tags->nr_tags) {
- struct blk_mq_tag_set *set = hctx->queue->tag_set;
+ max_depth = can_grow ? tags->nr_tags: set->queue_depth;
+ if (tdepth > max_depth) {
struct blk_mq_tags *new;
bool ret;
--
2.9.5
