Merge tag 'for-linus-20191010' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Fix wbt performance regression introduced with the blk-rq-qos
   refactoring (Harshad)

 - Fix io_uring fileset removal inadvertently killing the workqueue (me)

 - Fix io_uring typo in linked command nonblock submission (Pavel)

 - Remove spurious io_uring wakeups on request free (Pavel)

 - Fix null_blk zoned command error return (Keith)

 - Don't use freezable workqueues for backing_dev, also means we can
   revert a previous libata hack (Mika)

 - Fix nbd sysfs mutex dropped too soon at removal time (Xiubo)

* tag 'for-linus-20191010' of git://git.kernel.dk/linux-block:
  nbd: fix possible sysfs duplicate warning
  null_blk: Fix zoned command return code
  io_uring: only flush workqueues on fileset removal
  io_uring: remove wait loop spurious wakeups
  blk-wbt: fix performance regression in wbt scale_up/scale_down
  Revert "libata, freezer: avoid block device removal while system is frozen"
  bdi: Do not use freezable workqueue
  io_uring: fix reversed nonblock flag for link submission

3 files changed, 2 insertions, 24 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 76d0f9de767b..58e09ffe8b9c 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -4791,27 +4791,6 @@ void ata_scsi_hotplug(struct work_struct *work)
 		return;
 	}
 
-	/*
-	 * XXX - UGLY HACK
-	 *
-	 * The block layer suspend/resume path is fundamentally broken due
-	 * to freezable kthreads and workqueue and may deadlock if a block
-	 * device gets removed while resume is in progress.  I don't know
-	 * what the solution is short of removing freezable kthreads and
-	 * workqueues altogether.
-	 *
-	 * The following is an ugly hack to avoid kicking off device
-	 * removal while freezer is active.  This is a joke but does avoid
-	 * this particular deadlock scenario.
-	 *
-	 * https://bugzilla.kernel.org/show_bug.cgi?id=62801
-	 * http://marc.info/?l=linux-kernel&m=138695698516487
-	 */
-#ifdef CONFIG_FREEZER
-	while (pm_freezing)
-		msleep(10);
-#endif
-
 	DPRINTK("ENTER\n");
 	mutex_lock(&ap->scsi_scan_mutex);
 
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index ac07e8c94c79..478aa86fc1f2 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -248,8 +248,8 @@ static void nbd_put(struct nbd_device *nbd)
 	if (refcount_dec_and_mutex_lock(&nbd->refs,
 					&nbd_index_mutex)) {
 		idr_remove(&nbd_index_idr, nbd->index);
-		mutex_unlock(&nbd_index_mutex);
 		nbd_dev_remove(nbd);
+		mutex_unlock(&nbd_index_mutex);
 	}
 }
 
diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
index eabc116832a7..3d7fdea872f8 100644
--- a/drivers/block/null_blk_zoned.c
+++ b/drivers/block/null_blk_zoned.c
@@ -142,8 +142,7 @@ static blk_status_t null_zone_reset(struct nullb_cmd *cmd, sector_t sector)
 		zone->wp = zone->start;
 		break;
 	default:
-		cmd->error = BLK_STS_NOTSUPP;
-		break;
+		return BLK_STS_NOTSUPP;
 	}
 	return BLK_STS_OK;
 }