block: add @force_kblockd to __blk_run_queue()

__blk_run_queue() automatically either calls q->request_fn() directly
or schedules kblockd depending on whether the function is recursed.
blk-flush implementation needs to be able to explicitly choose
kblockd.  Add @force_kblockd.

All the current users are converted to specify %false for the
parameter and this patch doesn't introduce any behavior change.

stable: This is prerequisite for fixing ide oops caused by the new
        blk-flush implementation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

diff --git a/block/blk-core.c b/block/blk-core.c
index 792ece2..518dd42 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -352,7 +352,7 @@ void blk_start_queue(struct request_queue *q)
        WARN_ON(!irqs_disabled());
 
        queue_flag_clear(QUEUE_FLAG_STOPPED, q);
-       __blk_run_queue(q);
+       __blk_run_queue(q, false);
 }
 EXPORT_SYMBOL(blk_start_queue);
 
@@ -403,13 +403,14 @@ EXPORT_SYMBOL(blk_sync_queue);
 /**
  * __blk_run_queue - run a single device queue
  * @q: The queue to run
+ * @force_kblockd: Don't run @q->request_fn directly.  Use kblockd.
  *
  * Description:
  *    See @blk_run_queue. This variant must be called with the queue lock
  *    held and interrupts disabled.
  *
  */
-void __blk_run_queue(struct request_queue *q)
+void __blk_run_queue(struct request_queue *q, bool force_kblockd)
 {
        blk_remove_plug(q);
 
@@ -423,7 +424,7 @@ void __blk_run_queue(struct request_queue *q)
         * Only recurse once to avoid overrunning the stack, let the unplug
         * handling reinvoke the handler shortly if we already got there.
         */
-       if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
+       if (!force_kblockd && !queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
                q->request_fn(q);
                queue_flag_clear(QUEUE_FLAG_REENTER, q);
        } else {
@@ -446,7 +447,7 @@ void blk_run_queue(struct request_queue *q)
        unsigned long flags;
 
        spin_lock_irqsave(q->queue_lock, flags);
-       __blk_run_queue(q);
+       __blk_run_queue(q, false);
        spin_unlock_irqrestore(q->queue_lock, flags);
 }
 EXPORT_SYMBOL(blk_run_queue);
@@ -1053,7 +1054,7 @@ void blk_insert_request(struct request_queue *q, struct request *rq,
 
        drive_stat_acct(rq, 1);
        __elv_add_request(q, rq, where, 0);
-       __blk_run_queue(q);
+       __blk_run_queue(q, false);
        spin_unlock_irqrestore(q->queue_lock, flags);
 }
 EXPORT_SYMBOL(blk_insert_request);

diff --git a/block/blk-flush.c b/block/blk-flush.c
index 54b123d..56adaa8 100644 (file)
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -69,7 +69,7 @@ static void blk_flush_complete_seq_end_io(struct request_queue *q,
         * queue.  Kick the queue in those cases.
         */
        if (was_empty && next_rq)
-               __blk_run_queue(q);
+               __blk_run_queue(q, false);
 }
 
 static void pre_flush_end_io(struct request *rq, int error)

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 7be4c79..ea83a4f 100644 (file)
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3355,7 +3355,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
                            cfqd->busy_queues > 1) {
                                cfq_del_timer(cfqd, cfqq);
                                cfq_clear_cfqq_wait_request(cfqq);
-                               __blk_run_queue(cfqd->queue);
+                               __blk_run_queue(cfqd->queue, false);
                        } else {
                                cfq_blkiocg_update_idle_time_stats(
                                                &cfqq->cfqg->blkg);
@@ -3370,7 +3370,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
                 * this new queue is RT and the current one is BE
                 */
                cfq_preempt_queue(cfqd, cfqq);
-               __blk_run_queue(cfqd->queue);
+               __blk_run_queue(cfqd->queue, false);
        }
 }
 
@@ -3731,7 +3731,7 @@ static void cfq_kick_queue(struct work_struct *work)
        struct request_queue *q = cfqd->queue;
 
        spin_lock_irq(q->queue_lock);
-       __blk_run_queue(cfqd->queue);
+       __blk_run_queue(cfqd->queue, false);
        spin_unlock_irq(q->queue_lock);
 }
 

diff --git a/block/elevator.c b/block/elevator.c
index 2569512..236e93c 100644 (file)
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -602,7 +602,7 @@ void elv_quiesce_start(struct request_queue *q)
         */
        elv_drain_elevator(q);
        while (q->rq.elvpriv) {
-               __blk_run_queue(q);
+               __blk_run_queue(q, false);
                spin_unlock_irq(q->queue_lock);
                msleep(10);
                spin_lock_irq(q->queue_lock);
@@ -651,7 +651,7 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
                 *   with anything.  There's no point in delaying queue
                 *   processing.
                 */
-               __blk_run_queue(q);
+               __blk_run_queue(q, false);
                break;
 
        case ELEVATOR_INSERT_SORT:

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 9045c52..fb2bb35 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -443,7 +443,7 @@ static void scsi_run_queue(struct request_queue *q)
                                        &sdev->request_queue->queue_flags);
                if (flagset)
                        queue_flag_set(QUEUE_FLAG_REENTER, sdev->request_queue);
-               __blk_run_queue(sdev->request_queue);
+               __blk_run_queue(sdev->request_queue, false);
                if (flagset)
                        queue_flag_clear(QUEUE_FLAG_REENTER, sdev->request_queue);
                spin_unlock(sdev->request_queue->queue_lock);

diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 998c01b..5c3ccfc 100644 (file)
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -3829,7 +3829,7 @@ fc_bsg_goose_queue(struct fc_rport *rport)
                  !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);
+       __blk_run_queue(rport->rqst_q, false);
        if (flagset)
                queue_flag_clear(QUEUE_FLAG_REENTER, rport->rqst_q);
        spin_unlock_irqrestore(rport->rqst_q->queue_lock, flags);

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index dd8cd0f..d5063e1 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -699,7 +699,7 @@ extern void blk_start_queue(struct request_queue *q);
 extern void blk_stop_queue(struct request_queue *q);
 extern void blk_sync_queue(struct request_queue *q);
 extern void __blk_stop_queue(struct request_queue *q);
-extern void __blk_run_queue(struct request_queue *);
+extern void __blk_run_queue(struct request_queue *q, bool force_kblockd);
 extern void blk_run_queue(struct request_queue *);
 extern int blk_rq_map_user(struct request_queue *, struct request *,
                           struct rq_map_data *, void __user *, unsigned long,