Merge tag 'for-5.20/block-2022-08-04' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:

 - NVMe pull requests via Christoph:
      - add support for In-Band authentication (Hannes Reinecke)
      - handle the persistent internal error AER (Michael Kelley)
      - use in-capsule data for TCP I/O queue connect (Caleb Sander)
      - remove timeout for getting RDMA-CM established event (Israel
        Rukshin)
      - misc cleanups (Joel Granados, Sagi Grimberg, Chaitanya Kulkarni,
        Guixin Liu, Xiang wangx)
      - use command_id instead of req->tag in trace_nvme_complete_rq()
        (Bean Huo)
      - various fixes for the new authentication code (Lukas Bulwahn,
        Dan Carpenter, Colin Ian King, Chaitanya Kulkarni, Hannes
        Reinecke)
      - small cleanups (Liu Song, Christoph Hellwig)
      - restore compat_ioctl support (Nick Bowler)
      - make a nvmet-tcp workqueue lockdep-safe (Sagi Grimberg)
      - enable generic interface (/dev/ngXnY) for unknown command sets
        (Joel Granados, Christoph Hellwig)
      - don't always build constants.o (Christoph Hellwig)
      - print the command name of aborted commands (Christoph Hellwig)

 - MD pull requests via Song:
      - Improve raid5 lock contention, by Logan Gunthorpe.
      - Misc fixes to raid5, by Logan Gunthorpe.
      - Fix race condition with md_reap_sync_thread(), by Guoqing Jiang.
      - Fix potential deadlock with raid5_quiesce and
        raid5_get_active_stripe, by Logan Gunthorpe.
      - Refactoring md_alloc(), by Christoph"
      - Fix md disk_name lifetime problems, by Christoph Hellwig
      - Convert prepare_to_wait() to wait_woken() api, by Logan
        Gunthorpe;
      - Fix sectors_to_do bitmap issue, by Logan Gunthorpe.

 - Work on unifying the null_blk module parameters and configfs API
   (Vincent)

 - drbd bitmap IO error fix (Lars)

 - Set of rnbd fixes (Guoqing, Md Haris)

 - Remove experimental marker on bcache async device registration (Coly)

 - Series from cleaning up the bio splitting (Christoph)

 - Removal of the sx8 block driver. This hardware never really
   widespread, and it didn't receive a lot of attention after the
   initial merge of it back in 2005 (Christoph)

 - A few fixes for s390 dasd (Eric, Jiang)

 - Followup set of fixes for ublk (Ming)

 - Support for UBLK_IO_NEED_GET_DATA for ublk (ZiyangZhang)

 - Fixes for the dio dma alignment (Keith)

 - Misc fixes and cleanups (Ming, Yu, Dan, Christophe

* tag 'for-5.20/block-2022-08-04' of git://git.kernel.dk/linux-block: (136 commits)
  s390/dasd: Establish DMA alignment
  s390/dasd: drop unexpected word 'for' in comments
  ublk_drv: add support for UBLK_IO_NEED_GET_DATA
  ublk_cmd.h: add one new ublk command: UBLK_IO_NEED_GET_DATA
  ublk_drv: cleanup ublksrv_ctrl_dev_info
  ublk_drv: add SET_PARAMS/GET_PARAMS control command
  ublk_drv: fix ublk device leak in case that add_disk fails
  ublk_drv: cancel device even though disk isn't up
  block: fix leaking page ref on truncated direct io
  block: ensure bio_iov_add_page can't fail
  block: ensure iov_iter advances for added pages
  drivers:md:fix a potential use-after-free bug
  md/raid5: Ensure batch_last is released before sleeping for quiesce
  md/raid5: Move stripe_request_ctx up
  md/raid5: Drop unnecessary call to r5c_check_stripe_cache_usage()
  md/raid5: Make is_inactive_blocked() helper
  md/raid5: Refactor raid5_get_active_stripe()
  block: pass struct queue_limits to the bio splitting helpers
  block: move bio_allowed_max_sectors to blk-merge.c
  block: move the call to get_max_io_size out of blk_bio_segment_split
  ...

1 files changed, 22 insertions, 0 deletions

diff --git a/Documentation/block/null_blk.rst b/Documentation/block/null_blk.rst
index edbbab2f12f8..4dd78f24d10a 100644
--- a/Documentation/block/null_blk.rst
+++ b/Documentation/block/null_blk.rst
@@ -72,6 +72,28 @@ submit_queues=[1..nr_cpus]: Default: 1
 hw_queue_depth=[0..qdepth]: Default: 64
   The hardware queue depth of the device.
 
+memory_backed=[0/1]: Default: 0
+  Whether or not to use a memory buffer to respond to IO requests
+
+  =  =============================================
+  0  Transfer no data in response to IO requests
+  1  Use a memory buffer to respond to IO requests
+  =  =============================================
+
+discard=[0/1]: Default: 0
+  Support discard operations (requires memory-backed null_blk device).
+
+  =  =====================================
+  0  Do not support discard operations
+  1  Enable support for discard operations
+  =  =====================================
+
+cache_size=[Size in MB]: Default: 0
+  Cache size in MB for memory-backed device.
+
+mbps=[Maximum bandwidth in MB/s]: Default: 0 (no limit)
+  Bandwidth limit for device performance.
+
 Multi-queue specific parameters
 -------------------------------