Merge branch 'for-linus' of git://git.kernel.dk/linux-block

Pull block layer fixes from Jens Axboe:
 "A small collection of fixes that should go in before -rc1.  The pull
  request contains:

   - A two patch fix for a regression with block enabled tagging caused
     by a commit in the initial pull request.  One patch is from Martin
     and ensures that SCSI doesn't truncate 64-bit block flags, the
     other one is from me and prevents us from double using struct
     request queuelist for both completion and busy tags.  This caused
     anything from a boot crash for some, to crashes under load.

   - A blk-mq fix for a potential soft stall when hot unplugging CPUs
     with busy IO.

   - percpu_counter fix is listed in here, that caused a suspend issue
     with virtio-blk due to percpu counters having an inconsistent state
     during CPU removal.  Andrew sent this in separately a few days ago,
     but it's here.  JFYI.

   - A few fixes for block integrity from Martin.

   - A ratelimit fix for loop from Mike Galbraith, to avoid spewing too
     much in error cases"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: fix regression with block enabled tagging
  scsi: Make sure cmd_flags are 64-bit
  block: Ensure we only enable integrity metadata for reads and writes
  block: Fix integrity verification
  block: Fix for_each_bvec()
  drivers/block/loop.c: ratelimit error messages
  blk-mq: fix potential stall during CPU unplug with IO pending
  percpu_counter: fix bad counter state during suspend

12 files changed, 53 insertions, 37 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 34d7c196338b..a0e3096c4bb5 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1307,7 +1307,7 @@ void __blk_put_request(struct request_queue *q, struct request *req)
                 struct request_list *rl = blk_rq_rl(req);
 
                 BUG_ON(!list_empty(&req->queuelist));
-                BUG_ON(!hlist_unhashed(&req->hash));
+                BUG_ON(ELV_ON_HASH(req));
 
                 blk_free_request(rl, req);
                 freed_request(rl, flags);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b1bcc619d0ea..1d2a9bdbee57 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -956,6 +956,7 @@ static void blk_mq_hctx_notify(void *data, unsigned long action,
                                unsigned int cpu)
 {
         struct blk_mq_hw_ctx *hctx = data;
+        struct request_queue *q = hctx->queue;
         struct blk_mq_ctx *ctx;
         LIST_HEAD(tmp);
 
@@ -965,7 +966,7 @@ static void blk_mq_hctx_notify(void *data, unsigned long action,
         /*
          * Move ctx entries to new CPU, if this one is going away.
          */
-        ctx = __blk_mq_get_ctx(hctx->queue, cpu);
+        ctx = __blk_mq_get_ctx(q, cpu);
 
         spin_lock(&ctx->lock);
         if (!list_empty(&ctx->rq_list)) {
@@ -977,7 +978,7 @@ static void blk_mq_hctx_notify(void *data, unsigned long action,
         if (list_empty(&tmp))
                 return;
 
-        ctx = blk_mq_get_ctx(hctx->queue);
+        ctx = blk_mq_get_ctx(q);
         spin_lock(&ctx->lock);
 
         while (!list_empty(&tmp)) {
@@ -988,10 +989,13 @@ static void blk_mq_hctx_notify(void *data, unsigned long action,
                 list_move_tail(&rq->queuelist, &ctx->rq_list);
         }
 
+        hctx = q->mq_ops->map_queue(q, ctx->cpu);
         blk_mq_hctx_mark_pending(hctx, ctx);
 
         spin_unlock(&ctx->lock);
         blk_mq_put_ctx(ctx);
+
+        blk_mq_run_hw_queue(hctx, true);
 }
 
 static int blk_mq_init_hw_commands(struct blk_mq_hw_ctx *hctx,
diff --git a/block/blk-softirq.c b/block/blk-softirq.c
index ebd6b6f1bdeb..53b1737e978d 100644
--- a/block/blk-softirq.c
+++ b/block/blk-softirq.c
@@ -30,8 +30,8 @@ static void blk_done_softirq(struct softirq_action *h)
         while (!list_empty(&local_list)) {
                 struct request *rq;
 
-                rq = list_entry(local_list.next, struct request, queuelist);
-                list_del_init(&rq->queuelist);
+                rq = list_entry(local_list.next, struct request, ipi_list);
+                list_del_init(&rq->ipi_list);
                 rq->q->softirq_done_fn(rq);
         }
 }
@@ -45,14 +45,9 @@ static void trigger_softirq(void *data)
 
         local_irq_save(flags);
         list = this_cpu_ptr(&blk_cpu_done);
-        /*
-         * We reuse queuelist for a list of requests to process. Since the
-         * queuelist is used by the block layer only for requests waiting to be
-         * submitted to the device it is unused now.
-         */
-        list_add_tail(&rq->queuelist, list);
+        list_add_tail(&rq->ipi_list, list);
 
-        if (list->next == &rq->queuelist)
+        if (list->next == &rq->ipi_list)
                 raise_softirq_irqoff(BLOCK_SOFTIRQ);
 
         local_irq_restore(flags);
@@ -141,7 +136,7 @@ void __blk_complete_request(struct request *req)
                 struct list_head *list;
 do_local:
                 list = this_cpu_ptr(&blk_cpu_done);
-                list_add_tail(&req->queuelist, list);
+                list_add_tail(&req->ipi_list, list);
 
                 /*
                  * if the list only contains our just added request,
@@ -149,7 +144,7 @@ do_local:
                  * entries there, someone already raised the irq but it
                  * hasn't run yet.
                  */
-                if (list->next == &req->queuelist)
+                if (list->next == &req->ipi_list)
                         raise_softirq_irqoff(BLOCK_SOFTIRQ);
         } else if (raise_blk_irq(ccpu, req))
                 goto do_local;
diff --git a/block/blk.h b/block/blk.h
index d23b415b8a28..1d880f1f957f 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -78,7 +78,7 @@ static inline void blk_clear_rq_complete(struct request *rq)
 /*
  * Internal elevator interface
  */
-#define ELV_ON_HASH(rq) hash_hashed(&(rq)->hash)
+#define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED)
 
 void blk_insert_flush(struct request *rq);
 void blk_abort_flushes(struct request_queue *q);
diff --git a/block/elevator.c b/block/elevator.c
index 42c45a7d6714..1e01b66a0b92 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -247,6 +247,7 @@ EXPORT_SYMBOL(elevator_exit);
 static inline void __elv_rqhash_del(struct request *rq)
 {
         hash_del(&rq->hash);
+        rq->cmd_flags &= ~REQ_HASHED;
 }
 
 static void elv_rqhash_del(struct request_queue *q, struct request *rq)
@@ -261,6 +262,7 @@ static void elv_rqhash_add(struct request_queue *q, struct request *rq)
 
         BUG_ON(ELV_ON_HASH(rq));
         hash_add(e->hash, &rq->hash, rq_hash_key(rq));
+        rq->cmd_flags |= REQ_HASHED;
 }
 
 static void elv_rqhash_reposition(struct request_queue *q, struct request *rq)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 66e8c3b94ef3..f70a230a2945 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -237,7 +237,7 @@ static int __do_lo_send_write(struct file *file,
         file_end_write(file);
         if (likely(bw == len))
                 return 0;
-        printk(KERN_ERR "loop: Write error at byte offset %llu, length %i.\n",
+        printk_ratelimited(KERN_ERR "loop: Write error at byte offset %llu, length %i.\n",
                         (unsigned long long)pos, len);
         if (bw >= 0)
                 bw = -EIO;
@@ -277,7 +277,7 @@ static int do_lo_send_write(struct loop_device *lo, struct bio_vec *bvec,
                 return __do_lo_send_write(lo->lo_backing_file,
                                 page_address(page), bvec->bv_len,