diff options
| author | Bart Van Assche <bart.vanassche@wdc.com> | 2017-11-09 10:49:57 -0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2017-11-10 19:53:25 -0700 |
| commit | c9254f2ddb19387ea9714a57ea48463c20333b92 (patch) | |
| tree | 8b0ded19c9d2847de42e971b9f951570416acc60 | |
| parent | 039c635f4e666b647df2100038de276a83fb3fca (diff) | |
block: Add the QUEUE_FLAG_PREEMPT_ONLY request queue flag
This flag will be used in the next patch to let the block layer
core know whether or not a SCSI request queue has been quiesced.
A quiesced SCSI queue namely only processes RQF_PREEMPT requests.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Martin Steigerwald <martin@lichtvoll.de>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-core.c | 30 | ||||
| -rw-r--r-- | block/blk-mq-debugfs.c | 1 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 6 |
3 files changed, 37 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 17eed16a6e04..edc276899116 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -349,6 +349,36 @@ void blk_sync_queue(struct request_queue *q) EXPORT_SYMBOL(blk_sync_queue); /** + * blk_set_preempt_only - set QUEUE_FLAG_PREEMPT_ONLY + * @q: request queue pointer + * + * Returns the previous value of the PREEMPT_ONLY flag - 0 if the flag was not + * set and 1 if the flag was already set. + */ +int blk_set_preempt_only(struct request_queue *q) +{ + unsigned long flags; + int res; + + spin_lock_irqsave(q->queue_lock, flags); + res = queue_flag_test_and_set(QUEUE_FLAG_PREEMPT_ONLY, q); + spin_unlock_irqrestore(q->queue_lock, flags); + + return res; +} +EXPORT_SYMBOL_GPL(blk_set_preempt_only); + +void blk_clear_preempt_only(struct request_queue *q) +{ + unsigned long flags; + + spin_lock_irqsave(q->queue_lock, flags); + queue_flag_clear(QUEUE_FLAG_PREEMPT_ONLY, q); + spin_unlock_irqrestore(q->queue_lock, flags); +} +EXPORT_SYMBOL_GPL(blk_clear_preempt_only); + +/** * __blk_run_queue_uncond - run a queue whether or not it has been stopped * @q: The queue to run * diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index bb7f08415203..e4f2bb936e66 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -74,6 +74,7 @@ static const char *const blk_queue_flag_name[] = { QUEUE_FLAG_NAME(REGISTERED), QUEUE_FLAG_NAME(SCSI_PASSTHROUGH), QUEUE_FLAG_NAME(QUIESCED), + QUEUE_FLAG_NAME(PREEMPT_ONLY), }; #undef QUEUE_FLAG_NAME diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 1af5ddd0f631..2147e2381a22 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -632,6 +632,7 @@ struct request_queue { #define QUEUE_FLAG_REGISTERED 26 /* queue has been registered to a disk */ #define QUEUE_FLAG_SCSI_PASSTHROUGH 27 /* queue supports SCSI commands */ #define QUEUE_FLAG_QUIESCED 28 /* queue has been quiesced */ +#define QUEUE_FLAG_PREEMPT_ONLY 29 /* only process REQ_PREEMPT requests */ #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_SAME_COMP) | \ @@ -732,6 +733,11 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \ REQ_FAILFAST_DRIVER)) #define blk_queue_quiesced(q) test_bit(QUEUE_FLAG_QUIESCED, &(q)->queue_flags) +#define blk_queue_preempt_only(q) \ + test_bit(QUEUE_FLAG_PREEMPT_ONLY, &(q)->queue_flags) + +extern int blk_set_preempt_only(struct request_queue *q); +extern void blk_clear_preempt_only(struct request_queue *q); static inline bool blk_account_rq(struct request *rq) { |