4 files changed, 22 insertions, 17 deletions

diff --git a/drivers/block/elevator.c b/drivers/block/elevator.c
index 6b79b4314622..8c51d1ccebbd 100644
--- a/drivers/block/elevator.c
+++ b/drivers/block/elevator.c
@@ -291,6 +291,13 @@ void elv_requeue_request(request_queue_t *q, struct request *rq)
         }
 
         /*
+         * 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
          */
@@ -386,6 +393,12 @@ 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) {
diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
index 11ef9d9ea139..f20eba22b14b 100644
--- a/drivers/block/ll_rw_blk.c
+++ b/drivers/block/ll_rw_blk.c
@@ -2038,7 +2038,6 @@ EXPORT_SYMBOL(blk_requeue_request);
  * @rq:         request to be inserted
  * @at_head:    insert request at head or tail of queue
  * @data:       private data
- * @reinsert:   true if request it a reinsertion of previously processed one
  *
  * Description:
  *    Many block devices need to execute commands asynchronously, so they don't
@@ -2053,8 +2052,9 @@ EXPORT_SYMBOL(blk_requeue_request);
  *    host that is unable to accept a particular command.
  */
 void blk_insert_request(request_queue_t *q, struct request *rq,
-                        int at_head, void *data, int reinsert)
+                        int at_head, void *data)
 {
+        int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
         unsigned long flags;
 
         /*
@@ -2071,20 +2071,12 @@ void blk_insert_request(request_queue_t *q, struct request *rq,
         /*
          * If command is tagged, release the tag
          */
-        if (reinsert)
-                blk_requeue_request(q, rq);
-        else {
-                int where = ELEVATOR_INSERT_BACK;
-
-                if (at_head)
-                        where = ELEVATOR_INSERT_FRONT;
+        if (blk_rq_tagged(rq))
+                blk_queue_end_tag(q, rq);
 
-                if (blk_rq_tagged(rq))
-                        blk_queue_end_tag(q, rq);
+        drive_stat_acct(rq, rq->nr_sectors, 1);
+        __elv_add_request(q, rq, where, 0);
 
-                drive_stat_acct(rq, rq->nr_sectors, 1);
-                __elv_add_request(q, rq, where, 0);
-        }
         if (blk_queue_plugged(q))
                 __generic_unplug_device(q);
         else
diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c
index 202a5a74ad37..fa49d62626ba 100644
--- a/drivers/block/paride/pd.c
+++ b/drivers/block/paride/pd.c
@@ -723,7 +723,7 @@ static int pd_special_command(struct pd_unit *disk,
         rq.ref_count = 1;
         rq.waiting = &wait;
         rq.end_io = blk_end_sync_rq;
-        blk_insert_request(disk->gd->queue, &rq, 0, func, 0);
+        blk_insert_request(disk->gd->queue, &rq, 0, func);
         wait_for_completion(&wait);
         rq.waiting = NULL;
         if (rq.errors)
diff --git a/drivers/block/sx8.c b/drivers/block/sx8.c
index 797f5988c2b5..5ed3a6379452 100644
--- a/drivers/block/sx8.c
+++ b/drivers/block/sx8.c
@@ -614,7 +614,7 @@ static int carm_array_info (struct carm_host *host, unsigned int array_idx)
         spin_unlock_irq(&host->lock);
 
         DPRINTK("blk_insert_request, tag == %u\n", idx);
-        blk_insert_request(host->oob_q, crq->rq, 1, crq, 0);
+        blk_insert_request(host->oob_q, crq->rq, 1, crq);
 
         return 0;
 
@@ -653,7 +653,7 @@ static int carm_send_special (struct carm_host *host, carm_sspc_t func)
         crq->msg_bucket = (u32) rc;
 
         DPRINTK("blk_insert_request, tag == %u\n", idx);
-        blk_insert_request(host->oob_q, crq->rq, 1, crq, 0);
+        blk_insert_request(host->oob_q, crq->rq, 1, crq);
 
         return 0;
 }