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[RESEND,v3,01/13] blk-mq: Change rqs check in blk_mq_free_rqs()

Message ID 1631545950-56586-2-git-send-email-john.garry@huawei.com
State New
Headers show
Series blk-mq: Reduce static requests memory footprint for shared sbitmap | expand

Commit Message

John Garry Sept. 13, 2021, 3:12 p.m. UTC
The original code in commit 24d2f90309b23 ("blk-mq: split out tag
initialization, support shared tags") would check tags->rqs is non-NULL and
then dereference tags->rqs[].

Then in commit 2af8cbe30531 ("blk-mq: split tag ->rqs[] into two"), we
started to dereference tags->static_rqs[], but continued to check non-NULL
tags->rqs.

Check tags->static_rqs as non-NULL instead, which is more logical.

Signed-off-by: John Garry <john.garry@huawei.com>

Reviewed-by: Ming Lei <ming.lei@redhat.com>

---
 block/blk-mq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.26.2

Comments

Hannes Reinecke Sept. 14, 2021, 5:35 a.m. UTC | #1
On 9/13/21 5:12 PM, John Garry wrote:
> The original code in commit 24d2f90309b23 ("blk-mq: split out tag

> initialization, support shared tags") would check tags->rqs is non-NULL and

> then dereference tags->rqs[].

> 

> Then in commit 2af8cbe30531 ("blk-mq: split tag ->rqs[] into two"), we

> started to dereference tags->static_rqs[], but continued to check non-NULL

> tags->rqs.

> 

> Check tags->static_rqs as non-NULL instead, which is more logical.

> 

> Signed-off-by: John Garry <john.garry@huawei.com>

> Reviewed-by: Ming Lei <ming.lei@redhat.com>

> ---

>   block/blk-mq.c | 2 +-

>   1 file changed, 1 insertion(+), 1 deletion(-)

> 

> diff --git a/block/blk-mq.c b/block/blk-mq.c

> index 108a352051be..2316ff27c1f5 100644

> --- a/block/blk-mq.c

> +++ b/block/blk-mq.c

> @@ -2340,7 +2340,7 @@ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,

>   {

>   	struct page *page;

>   

> -	if (tags->rqs && set->ops->exit_request) {

> +	if (tags->static_rqs && set->ops->exit_request) {

>   		int i;

>   

>   		for (i = 0; i < tags->nr_tags; i++) {

> 

Reviewed-by: Hannes Reinecke <hare@suse.de>


Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
diff mbox series

Patch

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 108a352051be..2316ff27c1f5 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2340,7 +2340,7 @@  void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
 {
 	struct page *page;
 
-	if (tags->rqs && set->ops->exit_request) {
+	if (tags->static_rqs && set->ops->exit_request) {
 		int i;
 
 		for (i = 0; i < tags->nr_tags; i++) {