[PATCH] sched cleanups

[pandora-kernel.git] / drivers / block / elevator.c

diff --git a/drivers/block/elevator.c b/drivers/block/elevator.c
index 8998292..98f0126 100644 (file)
--- a/drivers/block/elevator.c
+++ b/drivers/block/elevator.c
@@ -285,6 +285,13 @@ void elv_requeue_request(request_queue_t *q, struct request *rq)
                rq = rq->end_io_data;
        }
 
+       /*
+        * the request is prepped and may have some resources allocated.
+        * allowing unprepped requests to pass this one may cause resource
+        * deadlock.  turn on softbarrier.
+        */
+       rq->flags |= REQ_SOFTBARRIER;
+
        /*
         * if iosched has an explicit requeue hook, then use that. otherwise
         * just put the request at the front of the queue
@@ -381,6 +388,12 @@ struct request *elv_next_request(request_queue_t *q)
                if (ret == BLKPREP_OK) {
                        break;
                } else if (ret == BLKPREP_DEFER) {
+                       /*
+                        * the request may have been (partially) prepped.
+                        * we need to keep this request in the front to
+                        * avoid resource deadlock.  turn on softbarrier.
+                        */
+                       rq->flags |= REQ_SOFTBARRIER;
                        rq = NULL;
                        break;
                } else if (ret == BLKPREP_KILL) {
@@ -473,12 +486,13 @@ struct request *elv_former_request(request_queue_t *q, struct request *rq)
        return NULL;
 }
 
-int elv_set_request(request_queue_t *q, struct request *rq, int gfp_mask)
+int elv_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
+                   int gfp_mask)
 {
        elevator_t *e = q->elevator;
 
        if (e->ops->elevator_set_req_fn)
-               return e->ops->elevator_set_req_fn(q, rq, gfp_mask);
+               return e->ops->elevator_set_req_fn(q, rq, bio, gfp_mask);
 
        rq->elevator_private = NULL;
        return 0;
@@ -492,12 +506,12 @@ void elv_put_request(request_queue_t *q, struct request *rq)
                e->ops->elevator_put_req_fn(q, rq);
 }
 
-int elv_may_queue(request_queue_t *q, int rw)
+int elv_may_queue(request_queue_t *q, int rw, struct bio *bio)
 {
        elevator_t *e = q->elevator;
 
        if (e->ops->elevator_may_queue_fn)
-               return e->ops->elevator_may_queue_fn(q, rw);
+               return e->ops->elevator_may_queue_fn(q, rw, bio);
 
        return ELV_MQUEUE_MAY;
 }