[SCSI] export busy state via q->lld_busy_fn() (6c5121b7) · Commits · 戴 / test

drivers/scsi/scsi_lib.c

+32 −0

Original line number	Original line	Diff line number	Diff line
	@@ -1464,6 +1464,37 @@ static inline int scsi_host_queue_ready(struct request_queue *q,
	return 1;		return 1;
	}		}

			/*
			* Busy state exporting function for request stacking drivers.
			*
			* For efficiency, no lock is taken to check the busy state of
			* shost/starget/sdev, since the returned value is not guaranteed and
			* may be changed after request stacking drivers call the function,
			* regardless of taking lock or not.
			*
			* When scsi can't dispatch I/Os anymore and needs to kill I/Os
			* (e.g. !sdev), scsi needs to return 'not busy'.
			* Otherwise, request stacking drivers may hold requests forever.
			*/
			static int scsi_lld_busy(struct request_queue *q)
			{
			struct scsi_device *sdev = q->queuedata;
			struct Scsi_Host *shost;
			struct scsi_target *starget;

			if (!sdev)
			return 0;

			shost = sdev->host;
			starget = scsi_target(sdev);

			if (scsi_host_in_recovery(shost) \|\| scsi_host_is_busy(shost) \|\|
			scsi_target_is_busy(starget) \|\| scsi_device_is_busy(sdev))
			return 1;

			return 0;
			}

	/*		/*
	* Kill a request for a dead device		* Kill a request for a dead device
	*/		*/
	@@ -1767,6 +1798,7 @@ struct request_queue scsi_alloc_queue(struct scsi_device sdev)
	blk_queue_prep_rq(q, scsi_prep_fn);		blk_queue_prep_rq(q, scsi_prep_fn);
	blk_queue_softirq_done(q, scsi_softirq_done);		blk_queue_softirq_done(q, scsi_softirq_done);
	blk_queue_rq_timed_out(q, scsi_times_out);		blk_queue_rq_timed_out(q, scsi_times_out);
			blk_queue_lld_busy(q, scsi_lld_busy);
	return q;		return q;
	}		}