Merge tag 'for-5.19/drivers-2022-05-22' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:
 "Here are the driver updates queued up for 5.19. This contains:

   - NVMe pull requests via Christoph:
       - tighten the PCI presence check (Stefan Roese)
       - fix a potential NULL pointer dereference in an error path (Kyle
         Miller Smith)
       - fix interpretation of the DMRSL field (Tom Yan)
       - relax the data transfer alignment (Keith Busch)
       - verbose error logging improvements (Max Gurtovoy, Chaitanya
         Kulkarni)
       - misc cleanups (Chaitanya Kulkarni, Christoph)
       - set non-mdts limits in nvme_scan_work (Chaitanya Kulkarni)
       - add support for TP4084 - Time-to-Ready Enhancements (Christoph)

   - MD pull request via Song:
       - Improve annotation in raid5 code, by Logan Gunthorpe
       - Support MD_BROKEN flag in raid-1/5/10, by Mariusz Tkaczyk
       - Other small fixes/cleanups

   - null_blk series making the configfs side much saner (Damien)

   - Various minor drbd cleanups and fixes (Haowen, Uladzislau, Jiapeng,
     Arnd, Cai)

   - Avoid using the system workqueue (and hence flushing it) in rnbd
     (Jack)

   - Avoid using the system workqueue (and hence flushing it) in aoe
     (Tetsuo)

   - Series fixing discard_alignment issues in drivers (Christoph)

   - Small series fixing drivers poking at disk->part0 for openers
     information (Christoph)

   - Series fixing deadlocks in loop (Christoph, Tetsuo)

   - Remove loop.h and add SPDX headers (Christoph)

   - Various fixes and cleanups (Julia, Xie, Yu)"

* tag 'for-5.19/drivers-2022-05-22' of git://git.kernel.dk/linux-block: (72 commits)
  mtip32xx: fix typo in comment
  nvme: set non-mdts limits in nvme_scan_work
  nvme: add support for TP4084 - Time-to-Ready Enhancements
  nvme: split the enum used for various register constants
  nbd: Fix hung on disconnect request if socket is closed before
  nvme-fabrics: add a request timeout helper
  nvme-pci: harden drive presence detect in nvme_dev_disable()
  nvme-pci: fix a NULL pointer dereference in nvme_alloc_admin_tags
  nvme: mark internal passthru request RQF_QUIET
  nvme: remove unneeded include from constants file
  nvme: add missing status values to verbose logging
  nvme: set dma alignment to dword
  nvme: fix interpretation of DMRSL
  loop: remove most the top-of-file boilerplate comment from the UAPI header
  loop: remove most the top-of-file boilerplate comment
  loop: add a SPDX header
  loop: remove loop.h
  block: null_blk: Improve device creation with configfs
  block: null_blk: Cleanup messages
  block: null_blk: Cleanup device creation and deletion
  ...

1 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 34724b15813b..5bdf2ac9142c 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -176,6 +176,21 @@ static inline bool disk_live(struct gendisk *disk)
 	return !inode_unhashed(disk->part0->bd_inode);
 }
 
+/**
+ * disk_openers - returns how many openers are there for a disk
+ * @disk: disk to check
+ *
+ * This returns the number of openers for a disk.  Note that this value is only
+ * stable if disk->open_mutex is held.
+ *
+ * Note: Due to a quirk in the block layer open code, each open partition is
+ * only counted once even if there are multiple openers.
+ */
+static inline unsigned int disk_openers(struct gendisk *disk)
+{
+	return atomic_read(&disk->part0->bd_openers);
+}
+
 /*
  * The gendisk is refcounted by the part0 block_device, and the bd_device
  * therein is also used for device model presentation in sysfs.