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authorBart Van Assche <bart.vanassche@wdc.com>2017-11-09 10:49:57 -0800
committerJens Axboe <axboe@kernel.dk>2017-11-10 19:53:25 -0700
commitc9254f2ddb19387ea9714a57ea48463c20333b92 (patch)
tree8b0ded19c9d2847de42e971b9f951570416acc60 /block
parent039c635f4e666b647df2100038de276a83fb3fca (diff)
downloadlinux-stericsson-c9254f2ddb19387ea9714a57ea48463c20333b92.tar.gz
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>
Diffstat (limited to 'block')
-rw-r--r--block/blk-core.c30
-rw-r--r--block/blk-mq-debugfs.c1
2 files changed, 31 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