block: drop custom queue draining used by scsi_transport_{iscsi|fc}

iscsi_remove_host() uses bsg_remove_queue() which implements custom
queue draining.  fc_bsg_remove() open-codes mostly identical logic.

The draining logic isn't correct in that blk_stop_queue() doesn't
prevent new requests from being queued - it just stops processing, so
nothing prevents new requests to be queued after the logic determines
that the queue is drained.

blk_cleanup_queue() now implements proper queue draining and these
custom draining logics aren't necessary.  Drop them and use
bsg_unregister_queue() + blk_cleanup_queue() instead.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: James Smart <james.smart@emulex.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/bsg-lib.c b/block/bsg-lib.c
index 7ad49c8..deee61f 100644 (file)
--- a/block/bsg-lib.c
+++ b/block/bsg-lib.c
@@ -243,56 +243,3 @@ int bsg_setup_queue(struct device *dev, struct request_queue *q,
        return 0;
 }
 EXPORT_SYMBOL_GPL(bsg_setup_queue);
-
-/**
- * bsg_remove_queue - Deletes the bsg dev from the q
- * @q: the request_queue that is to be torn down.
- *
- * Notes:
- *   Before unregistering the queue empty any requests that are blocked
- */
-void bsg_remove_queue(struct request_queue *q)
-{
-       struct request *req; /* block request */
-       int counts; /* totals for request_list count and starved */
-
-       if (!q)
-               return;
-
-       /* Stop taking in new requests */
-       spin_lock_irq(q->queue_lock);
-       blk_stop_queue(q);
-
-       /* drain all requests in the queue */
-       while (1) {
-               /* need the lock to fetch a request
-                * this may fetch the same reqeust as the previous pass
-                */
-               req = blk_fetch_request(q);
-               /* save requests in use and starved */
-               counts = q->rq.count[0] + q->rq.count[1] +
-                        q->rq.starved[0] + q->rq.starved[1];
-               spin_unlock_irq(q->queue_lock);
-               /* any requests still outstanding? */
-               if (counts == 0)
-                       break;
-
-               /* This may be the same req as the previous iteration,
-                * always send the blk_end_request_all after a prefetch.
-                * It is not okay to not end the request because the
-                * prefetch started the request.
-                */
-               if (req) {
-                       /* return -ENXIO to indicate that this queue is
-                        * going away
-                        */
-                       req->errors = -ENXIO;
-                       blk_end_request_all(req, -ENXIO);
-               }
-
-               msleep(200); /* allow bsg to possibly finish */
-               spin_lock_irq(q->queue_lock);
-       }
-       bsg_unregister_queue(q);
-}
-EXPORT_SYMBOL_GPL(bsg_remove_queue);

diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 5797604..a9617ad 100644 (file)
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -4130,45 +4130,7 @@ fc_bsg_rportadd(struct Scsi_Host *shost, struct fc_rport *rport)
 static void
 fc_bsg_remove(struct request_queue *q)
 {
-       struct request *req; /* block request */
-       int counts; /* totals for request_list count and starved */
-
        if (q) {
-               /* Stop taking in new requests */
-               spin_lock_irq(q->queue_lock);
-               blk_stop_queue(q);
-
-               /* drain all requests in the queue */
-               while (1) {
-                       /* need the lock to fetch a request
-                        * this may fetch the same reqeust as the previous pass
-                        */
-                       req = blk_fetch_request(q);
-                       /* save requests in use and starved */
-                       counts = q->rq.count[0] + q->rq.count[1] +
-                               q->rq.starved[0] + q->rq.starved[1];
-                       spin_unlock_irq(q->queue_lock);
-                       /* any requests still outstanding? */
-                       if (counts == 0)
-                               break;
-
-                       /* This may be the same req as the previous iteration,
-                        * always send the blk_end_request_all after a prefetch.
-                        * It is not okay to not end the request because the
-                        * prefetch started the request.
-                        */
-                       if (req) {
-                               /* return -ENXIO to indicate that this queue is
-                                * going away
-                                */
-                               req->errors = -ENXIO;
-                               blk_end_request_all(req, -ENXIO);
-                       }
-
-                       msleep(200); /* allow bsg to possibly finish */
-                       spin_lock_irq(q->queue_lock);
-               }
-
                bsg_unregister_queue(q);
                blk_cleanup_queue(q);
        }

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 1cf640e..c737a16 100644 (file)
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -575,7 +575,7 @@ static int iscsi_remove_host(struct transport_container *tc,
        struct iscsi_cls_host *ihost = shost->shost_data;
 
        if (ihost->bsg_q) {
-               bsg_remove_queue(ihost->bsg_q);
+               bsg_unregister_queue(ihost->bsg_q);
                blk_cleanup_queue(ihost->bsg_q);
        }
        return 0;

diff --git a/include/linux/bsg-lib.h b/include/linux/bsg-lib.h
index f55ab8c..4d0fb3d 100644 (file)
--- a/include/linux/bsg-lib.h
+++ b/include/linux/bsg-lib.h
@@ -67,7 +67,6 @@ void bsg_job_done(struct bsg_job *job, int result,
 int bsg_setup_queue(struct device *dev, struct request_queue *q, char *name,
                    bsg_job_fn *job_fn, int dd_job_size);
 void bsg_request_fn(struct request_queue *q);
-void bsg_remove_queue(struct request_queue *q);
 void bsg_goose_queue(struct request_queue *q);
 
 #endif