diff options
| author |   Ming Lei <ming.lei@redhat.com> | 2022-06-16 09:44:00 +0800 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2022-06-16 14:45:15 -0600 |
| commit | 4d337cebcb1c27d9b48c48b9a98e939d4552d584 (patch) | |
| tree | 145de66b189943b28e6b089d4345459a7d22d2c6 /include | |
| parent | blk-mq: protect q->elevator by ->sysfs_lock in blk_mq_elv_switch_none (diff) | |
| download | linux-dev-4d337cebcb1c27d9b48c48b9a98e939d4552d584.tar.xz linux-dev-4d337cebcb1c27d9b48c48b9a98e939d4552d584.zip | |
blk-mq: avoid to touch q->elevator without any protection
q->elevator is referred in blk_mq_has_sqsched() without any protection,
no .q_usage_counter is held, no queue srcu and rcu read lock is held,
so potential use-after-free may be triggered.
Fix the issue by adding one queue flag for checking if the elevator
uses single queue style dispatch. Meantime the elevator feature flag
of ELEVATOR_F_MQ_AWARE isn't needed any more.
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220616014401.817001-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/blkdev.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 608d577734c2..bb6e3c31b3b7 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -575,6 +575,7 @@ struct request_queue { #define QUEUE_FLAG_RQ_ALLOC_TIME 27 /* record rq->alloc_time_ns */ #define QUEUE_FLAG_HCTX_ACTIVE 28 /* at least one blk-mq hctx is active */ #define QUEUE_FLAG_NOWAIT 29 /* device supports NOWAIT */ +#define QUEUE_FLAG_SQ_SCHED 30 /* single queue style io dispatch */ #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_SAME_COMP) | \ @@ -616,6 +617,7 @@ bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q); #define blk_queue_pm_only(q) atomic_read(&(q)->pm_only) #define blk_queue_registered(q) test_bit(QUEUE_FLAG_REGISTERED, &(q)->queue_flags) #define blk_queue_nowait(q) test_bit(QUEUE_FLAG_NOWAIT, &(q)->queue_flags) +#define blk_queue_sq_sched(q) test_bit(QUEUE_FLAG_SQ_SCHED, &(q)->queue_flags) extern void blk_set_pm_only(struct request_queue *q); extern void blk_clear_pm_only(struct request_queue *q); @@ -1006,8 +1008,6 @@ void disk_set_independent_access_ranges(struct gendisk *disk, */ /* Supports zoned block devices sequential write constraint */ #define ELEVATOR_F_ZBD_SEQ_WRITE (1U << 0) -/* Supports scheduling on multiple hardware queues */ -#define ELEVATOR_F_MQ_AWARE (1U << 1) extern void blk_queue_required_elevator_features(struct request_queue *q, unsigned int features); |