Commit 00e885ef authored by Chris Leech's avatar Chris Leech Committed by Jens Axboe

blk-mq: fix "bad unlock balance detected" on q->srcu in __blk_mq_run_dispatch_ops

The 'q' parameter of the macro __blk_mq_run_dispatch_ops may not be one
local variable, such as, it is rq->q, then request queue pointed by
this variable could be changed to another queue in case of
BLK_MQ_F_TAG_QUEUE_SHARED after 'dispatch_ops' returns, then
'bad unlock balance' is triggered.

Fixes the issue by adding one local variable for doing srcu lock/unlock.

Fixes: 2a904d00 ("blk-mq: remove hctx_lock and hctx_unlock")
Cc: Marco Patalano <mpatalan@redhat.com>
Signed-off-by: default avatarChris Leech <cleech@redhat.com>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230310010913.1014789-1-ming.lei@redhat.comSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 9b0cb770
...@@ -378,12 +378,13 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, ...@@ -378,12 +378,13 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
#define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops) \ #define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops) \
do { \ do { \
if ((q)->tag_set->flags & BLK_MQ_F_BLOCKING) { \ if ((q)->tag_set->flags & BLK_MQ_F_BLOCKING) { \
struct blk_mq_tag_set *__tag_set = (q)->tag_set; \
int srcu_idx; \ int srcu_idx; \
\ \
might_sleep_if(check_sleep); \ might_sleep_if(check_sleep); \
srcu_idx = srcu_read_lock((q)->tag_set->srcu); \ srcu_idx = srcu_read_lock(__tag_set->srcu); \
(dispatch_ops); \ (dispatch_ops); \
srcu_read_unlock((q)->tag_set->srcu, srcu_idx); \ srcu_read_unlock(__tag_set->srcu, srcu_idx); \
} else { \ } else { \
rcu_read_lock(); \ rcu_read_lock(); \
(dispatch_ops); \ (dispatch_ops); \
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment