From: Christof Schmitt <christof.schmitt@xxxxxxxxxx>
fc_bsg_goose_queue is only called from fc_remote_port_add which
already requires to be run from thread context. For this case simply
replace fc_bsg_goose_queue with a call to blk_run_queue.
The code in scsi_run_queue needs a mechanism to avoid recursing
through
scsi_run_queue->blk_run_queue->scsi_request_fn->scsi_dispatch_cmd
->scsi_queue_insert->scsi_run_queue for each entry in the
starved_list. Instead of using QUEUE_FLAG_PLUGGED, always defer
running the queue for starved devices to the block layer workqueue.
Signed-off-by: Christof Schmitt <christof.schmitt@xxxxxxxxxx>
---
drivers/scsi/scsi_lib.c | 17 +++--------------
drivers/scsi/scsi_transport_fc.c | 34 ++--------------------------------
2 files changed, 5 insertions(+), 46 deletions(-)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -411,8 +411,6 @@ static void scsi_run_queue(struct reques
list_splice_init(&shost->starved_list, &starved_list);
while (!list_empty(&starved_list)) {
- int flagset;
-
/*
* As long as shost is accepting commands and we have
* starved queues, call blk_run_queue. scsi_request_fn
@@ -435,20 +433,11 @@ static void scsi_run_queue(struct reques
continue;
}
- spin_unlock(shost->host_lock);
-
spin_lock(sdev->request_queue->queue_lock);
- flagset = test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) &&
- !test_bit(QUEUE_FLAG_REENTER,
- &sdev->request_queue->queue_flags);
- if (flagset)
- queue_flag_set(QUEUE_FLAG_REENTER, sdev->request_queue);
- __blk_run_queue(sdev->request_queue);
- if (flagset)
- queue_flag_clear(QUEUE_FLAG_REENTER, sdev->request_queue);
+ queue_flag_set(QUEUE_FLAG_PLUGGED, sdev->request_queue);
+ kblockd_schedule_work(sdev->request_queue,
+ &sdev->request_queue->unplug_work);
spin_unlock(sdev->request_queue->queue_lock);
-
- spin_lock(shost->host_lock);
}
/* put any unprocessed entries back */
list_splice(&starved_list, &shost->starved_list);
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -50,7 +50,6 @@ static int fc_vport_setup(struct Scsi_Ho
static int fc_bsg_hostadd(struct Scsi_Host *, struct fc_host_attrs *);
static int fc_bsg_rportadd(struct Scsi_Host *, struct fc_rport *);
static void fc_bsg_remove(struct request_queue *);
-static void fc_bsg_goose_queue(struct fc_rport *);
/*
* Redefine so that we can have same named attributes in the
@@ -2737,7 +2736,8 @@ fc_remote_port_add(struct Scsi_Host *sho
spin_unlock_irqrestore(shost->host_lock,
flags);
- fc_bsg_goose_queue(rport);
+ if (rport->rqst_q)
+ blk_run_queue(rport->rqst_q);
return rport;
}
@@ -3752,36 +3752,6 @@ fail_host_msg:
return FC_DISPATCH_UNLOCKED;
}
-
-/*
- * fc_bsg_goose_queue - restart rport queue in case it was stopped
- * @rport: rport to be restarted
- */
-static void
-fc_bsg_goose_queue(struct fc_rport *rport)
-{
- int flagset;
- unsigned long flags;
-
- if (!rport->rqst_q)
- return;
-
- get_device(&rport->dev);
-
- spin_lock_irqsave(rport->rqst_q->queue_lock, flags);
- flagset = test_bit(QUEUE_FLAG_REENTER, &rport->rqst_q->queue_flags) &&
- !test_bit(QUEUE_FLAG_REENTER, &rport->rqst_q->queue_flags);
- if (flagset)
- queue_flag_set(QUEUE_FLAG_REENTER, rport->rqst_q);
- __blk_run_queue(rport->rqst_q);
- if (flagset)
- queue_flag_clear(QUEUE_FLAG_REENTER, rport->rqst_q);
- spin_unlock_irqrestore(rport->rqst_q->queue_lock, flags);
-
- put_device(&rport->dev);
-}
-
-
/**
* fc_bsg_rport_dispatch - process rport bsg requests and dispatch to LLDD
* @q: rport request queue
--
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