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

Pull block fixes and updates from Jens Axboe:
 "Some fixes and followup features/changes that should go in, in this
  merge window. This contains:

   - Two fixes for lightnvm from Javier, fixing problems in the new code
     merge previously in this merge window.

   - A fix from Jan for the backing device changes, fixing an issue in
     NFS that causes a failure to mount on certain setups.

   - A change from Christoph, cleaning up the blk-mq init and exit
     request paths.

   - Remove elevator_change(), which is now unused. From Bart.

   - A fix for queue operation invocation on a dead queue, from Bart.

   - A series fixing up mtip32xx for blk-mq scheduling, removing a
     bandaid we previously had in place for this. From me.

   - A regression fix for this series, fixing a case where we wait on
     workqueue flushing from an invalid (non-blocking) context. From me.

   - A fix/optimization from Ming, ensuring that we don't both quiesce
     and freeze a queue at the same time.

   - A fix from Peter on lock ordering for CPU hotplug. Not a real
     problem right now, but will be once the CPU hotplug rework goes in.

   - A series from Omar, cleaning up out blk-mq debugfs support, and
     adding support for exporting info from schedulers in debugfs as
     well. This is really useful in debugging stalls or livelocks. From
     Omar"

* 'for-linus' of git://git.kernel.dk/linux-block: (28 commits)
  mq-deadline: add debugfs attributes
  kyber: add debugfs attributes
  blk-mq-debugfs: allow schedulers to register debugfs attributes
  blk-mq: untangle debugfs and sysfs
  blk-mq: move debugfs declarations to a separate header file
  blk-mq: Do not invoke queue operations on a dead queue
  blk-mq-debugfs: get rid of a bunch of boilerplate
  blk-mq-debugfs: rename hw queue directories from <n> to hctx<n>
  blk-mq-debugfs: don't open code strstrip()
  blk-mq-debugfs: error on long write to queue "state" file
  blk-mq-debugfs: clean up flag definitions
  blk-mq-debugfs: separate flags with |
  nfs: Fix bdi handling for cloned superblocks
  block/mq: Cure cpu hotplug lock inversion
  lightnvm: fix bad back free on error path
  lightnvm: create cmd before allocating request
  blk-mq: don't use sync workqueue flushing from drivers
  mtip32xx: convert internal commands to regular block infrastructure
  mtip32xx: cleanup internal tag assumptions
  block: don't call blk_mq_quiesce_queue() after queue is frozen
  ...

1 files changed, 17 insertions, 13 deletions

diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 8b361e192e8a..1f5b692526ae 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -11,6 +11,7 @@
 
 #include "blk.h"
 #include "blk-mq.h"
+#include "blk-mq-debugfs.h"
 #include "blk-mq-sched.h"
 #include "blk-mq-tag.h"
 #include "blk-wbt.h"
@@ -82,11 +83,7 @@ struct request *blk_mq_sched_get_request(struct request_queue *q,
 	if (likely(!data->hctx))
 		data->hctx = blk_mq_map_queue(q, data->ctx->cpu);
 
-	/*
-	 * For a reserved tag, allocate a normal request since we might
-	 * have driver dependencies on the value of the internal tag.
-	 */
-	if (e && !(data->flags & BLK_MQ_REQ_RESERVED)) {
+	if (e) {
 		data->flags |= BLK_MQ_REQ_INTERNAL;
 
 		/*
@@ -476,6 +473,8 @@ int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
 		}
 	}
 
+	blk_mq_debugfs_register_sched_hctx(q, hctx);
+
 	return 0;
 }
 
@@ -487,6 +486,8 @@ void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
 	if (!e)
 		return;
 
+	blk_mq_debugfs_unregister_sched_hctx(hctx);
+
 	if (e->type->ops.mq.exit_hctx && hctx->sched_data) {
 		e->type->ops.mq.exit_hctx(hctx, hctx_idx);
 		hctx->sched_data = NULL;
@@ -523,8 +524,10 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
 	if (ret)
 		goto err;
 
-	if (e->ops.mq.init_hctx) {
-		queue_for_each_hw_ctx(q, hctx, i) {
+	blk_mq_debugfs_register_sched(q);
+
+	queue_for_each_hw_ctx(q, hctx, i) {
+		if (e->ops.mq.init_hctx) {
 			ret = e->ops.mq.init_hctx(hctx, i);
 			if (ret) {
 				eq = q->elevator;
@@ -533,6 +536,7 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
 				return ret;
 			}
 		}
+		blk_mq_debugfs_register_sched_hctx(q, hctx);
 	}
 
 	return 0;
@@ -548,14 +552,14 @@ void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e)
 	struct blk_mq_hw_ctx *hctx;
 	unsigned int i;
 
-	if (e->type->ops.mq.exit_hctx) {
-		queue_for_each_hw_ctx(q, hctx, i) {
-			if (hctx->sched_data) {
-				e->type->ops.mq.exit_hctx(hctx, i);
-				hctx->sched_data = NULL;
-			}
+	queue_for_each_hw_ctx(q, hctx, i) {
+		blk_mq_debugfs_unregister_sched_hctx(hctx);
+		if (e->type->ops.mq.exit_hctx && hctx->sched_data) {
+			e->type->ops.mq.exit_hctx(hctx, i);
+			hctx->sched_data = NULL;
 		}
 	}
+	blk_mq_debugfs_unregister_sched(q);
 	if (e->type->ops.mq.exit_sched)
 		e->type->ops.mq.exit_sched(e);
 	blk_mq_sched_tags_teardown(q);