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

Pull block layer fixes from Jens Axboe:
 "Remember about a week ago when I sent the last pull request for 4.1?
  Well, I lied.  Now, I don't want to shift the blame, but Dan, Ming,
  and Richard made a liar out of me.

  Here are three small patches that should go into 4.1.  More
  specifically, this pull request contains:

   - A Kconfig dependency for the pmem block driver, so it can't be
     selected if HAS_IOMEM isn't availble.  From Richard Weinberger.

   - A fix for genhd, making the ext_devt_lock softirq safe.  This makes
     lockdep happier, since we also end up grabbing this lock on release
     off the softirq path.  From Dan Williams.

   - A blk-mq software queue release fix from Ming Lei.

  Last two are headed to stable, first fixes an issue introduced in this
  cycle"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: pmem: Add dependency on HAS_IOMEM
  block: fix ext_dev_lock lockdep report
  blk-mq: free hctx->ctxs in queue's release handler

3 files changed, 13 insertions, 8 deletions

diff --git a/block/blk-mq.c b/block/blk-mq.c
index e68b71b85a7e..594eea04266e 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1600,6 +1600,7 @@ static int blk_mq_hctx_notify(void *data, unsigned long action,
         return NOTIFY_OK;
 }
 
+/* hctx->ctxs will be freed in queue's release handler */
 static void blk_mq_exit_hctx(struct request_queue *q,
                 struct blk_mq_tag_set *set,
                 struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
@@ -1618,7 +1619,6 @@ static void blk_mq_exit_hctx(struct request_queue *q,
 
         blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
         blk_free_flush_queue(hctx->fq);
-        kfree(hctx->ctxs);
         blk_mq_free_bitmap(&hctx->ctx_map);
 }
 
@@ -1891,8 +1891,12 @@ void blk_mq_release(struct request_queue *q)
         unsigned int i;
 
         /* hctx kobj stays in hctx */
-        queue_for_each_hw_ctx(q, hctx, i)
+        queue_for_each_hw_ctx(q, hctx, i) {
+                if (!hctx)
+                        continue;
+                kfree(hctx->ctxs);
                 kfree(hctx);
+        }
 
         kfree(q->queue_hw_ctx);
 
diff --git a/block/genhd.c b/block/genhd.c
index 666e11b83983..ea982eadaf63 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -422,9 +422,9 @@ int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
         /* allocate ext devt */
         idr_preload(GFP_KERNEL);
 
-        spin_lock(&ext_devt_lock);
+        spin_lock_bh(&ext_devt_lock);
         idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_NOWAIT);
-        spin_unlock(&ext_devt_lock);
+        spin_unlock_bh(&ext_devt_lock);
 
         idr_preload_end();
         if (idx < 0)
@@ -449,9 +449,9 @@ void blk_free_devt(dev_t devt)
                 return;
 
         if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
-                spin_lock(&ext_devt_lock);
+                spin_lock_bh(&ext_devt_lock);
                 idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
-                spin_unlock(&ext_devt_lock);
+                spin_unlock_bh(&ext_devt_lock);
         }
 }
 
@@ -690,13 +690,13 @@ struct gendisk *get_gendisk(dev_t devt, int *partno)
         } else {
                 struct hd_struct *part;
 
-                spin_lock(&ext_devt_lock);
+                spin_lock_bh(&ext_devt_lock);
                 part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
                 if (part && get_disk(part_to_disk(part))) {
                         *partno = part->partno;
                         disk = part_to_disk(part);
                 }
-                spin_unlock(&ext_devt_lock);
+                spin_unlock_bh(&ext_devt_lock);
         }
 
         return disk;
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index eb1fed5bd516..3ccef9eba6f9 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -406,6 +406,7 @@ config BLK_DEV_RAM_DAX
 
 config BLK_DEV_PMEM
         tristate "Persistent memory block device support"
+        depends on HAS_IOMEM
         help
           Saying Y here will allow you to use a contiguous range of reserved
           memory as one or more persistent block devices.