2021-09-13 15:18:39

by John Garry

[permalink] [raw]
Subject: [PATCH RESEND v3 01/13] blk-mq: Change rqs check in blk_mq_free_rqs()

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 <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
---
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++) {
--
2.26.2


2021-09-14 05:37:03

by Hannes Reinecke

[permalink] [raw]
Subject: Re: [PATCH RESEND v3 01/13] blk-mq: Change rqs check in blk_mq_free_rqs()

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 <[email protected]>
> Reviewed-by: Ming Lei <[email protected]>
> ---
> 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 <[email protected]>

Cheers,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
[email protected] +49 911 74053 688
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