Pull block fixes from Jens Axboe:
 "All over the place fixes for this release:

   - blk-cgroup iteration teardown resched fix (Baolin)

   - NVMe pull request from Christoph:
        - add another Write Zeroes quirk (Chaitanya Kulkarni)
        - handle a no path available corner case (Daniel Wagner)
        - use the proper RCU aware list_add helper (Chao Leng)

   - bcache regression fix (Coly)

   - bdev->bd_size_lock IRQ fix. This will be fixed in drivers for 5.12,
     but for now, we'll make it IRQ safe (Damien)

   - null_blk zoned init fix (Damien)

   - add_partition() error handling fix (Dinghao)

   - s390 dasd kobject fix (Jan)

   - nbd fix for freezing queue while adding connections (Josef)

   - tag queueing regression fix (Ming)

   - revert of a patch that inadvertently meant that we regressed write
     performance on raid (Maxim)"

* tag 'block-5.11-2021-01-29' of git://git.kernel.dk/linux-block:
  null_blk: cleanup zoned mode initialization
  nvme-core: use list_add_tail_rcu instead of list_add_tail for nvme_init_ns_head
  nvme-multipath: Early exit if no path is available
  nvme-pci: add the DISABLE_WRITE_ZEROES quirk for a SPCC device
  bcache: only check feature sets when sb->version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES
  block: fix bd_size_lock use
  blk-cgroup: Use cond_resched() when destroy blkgs
  Revert "block: simplify set_init_blocksize" to regain lost performance
  nbd: freeze the queue while we're adding connections
  s390/dasd: Fix inconsistent kobject removal
  block: Fix an error handling in add_partition
  blk-mq: test QUEUE_FLAG_HCTX_ACTIVE for sbitmap_shared in hctx_may_queue

Some block device drivers, e.g. the skd driver, call set_capacity() with
IRQ disabled. This results in lockdep ito complain about inconsistent
lock states ("inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage")
because set_capacity takes a block device bd_size_lock using the
functions spin_lock() and spin_unlock(). Ensure a consistent locking
state by replacing these calls with spin_lock_irqsave() and
spin_lock_irqrestore(). The same applies to bdev_set_nr_sectors().
With this fix, all lockdep complaints are resolved.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

On !PREEMPT kernel, we can get below softlockup when doing stress
testing with creating and destroying block cgroup repeatly. The
reason is it may take a long time to acquire the queue's lock in
the loop of blkcg_destroy_blkgs(), or the system can accumulate a
huge number of blkgs in pathological cases. We can add a need_resched()
check on each loop and release locks and do cond_resched() if true
to avoid this issue, since the blkcg_destroy_blkgs() is not called
from atomic contexts.

[ 4757.010308] watchdog: BUG: soft lockup - CPU#11 stuck for 94s!
[ 4757.010698] Call trace:
[ 4757.010700]  blkcg_destroy_blkgs+0x68/0x150
[ 4757.010701]  cgwb_release_workfn+0x104/0x158
[ 4757.010702]  process_one_work+0x1bc/0x3f0
[ 4757.010704]  worker_thread+0x164/0x468
[ 4757.010705]  kthread+0x108/0x138

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Once we have called device_initialize(), we should use put_device() to
give up the reference on error, just like what we have done on failure
of device_add().

Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

In case of blk_mq_is_sbitmap_shared(), we should test QUEUE_FLAG_HCTX_ACTIVE against
q->queue_flags instead of BLK_MQ_S_TAG_ACTIVE.

So fix it.

Cc: John Garry <john.garry@huawei.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Fixes: f1b49fdc1c64 ("blk-mq: Record active_queues_shared_sbitmap per tag_set for when using shared sbitmap")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull block fixes from Jens Axboe:

 - Missing CRC32 selections (Arnd)

 - Fix for a merge window regression with bdev inode init (Christoph)

 - bcache fixes

 - rnbd fixes

 - NVMe pull request from Christoph:
    - fix a race in the nvme-tcp send code (Sagi Grimberg)
    - fix a list corruption in an nvme-rdma error path (Israel Rukshin)
    - avoid a possible double fetch in nvme-pci (Lalithambika Krishnakumar)
    - add the susystem NQN quirk for a Samsung driver (Gopal Tiwari)
    - fix two compiler warnings in nvme-fcloop (James Smart)
    - don't call sleeping functions from irq context in nvme-fc (James Smart)
    - remove an unused argument (Max Gurtovoy)
    - remove unused exports (Minwoo Im)

 - Use-after-free fix for partition iteration (Ming)

 - Missing blk-mq debugfs flag annotation (John)

 - Bdev freeze regression fix (Satya)

 - blk-iocost NULL pointer deref fix (Tejun)

* tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block: (26 commits)
  bcache: set bcache device into read-only mode for BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET
  bcache: introduce BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE for large bucket
  bcache: check unsupported feature sets for bcache register
  bcache: fix typo from SUUP to SUPP in features.h
  bcache: set pdev_set_uuid before scond loop iteration
  blk-mq-debugfs: Add decode for BLK_MQ_F_TAG_HCTX_SHARED
  block/rnbd-clt: avoid module unload race with close confirmation
  block/rnbd: Adding name to the Contributors List
  block/rnbd-clt: Fix sg table use after free
  block/rnbd-srv: Fix use after free in rnbd_srv_sess_dev_force_close
  block/rnbd: Select SG_POOL for RNBD_CLIENT
  block: pre-initialize struct block_device in bdev_alloc_inode
  fs: Fix freeze_bdev()/thaw_bdev() accounting of bd_fsfreeze_sb
  nvme: remove the unused status argument from nvme_trace_bio_complete
  nvmet-rdma: Fix list_del corruption on queue establishment failure
  nvme: unexport functions with no external caller
  nvme: avoid possible double fetch in handling CQE
  nvme-tcp: Fix possible race of io_work and direct send
  nvme-pci: mark Samsung PM1725a as IGNORE_DEV_SUBNQN
  nvme-fcloop: Fix sscanf type and list_first_entry_or_null warnings
  ...

Showing the hctx flags for when BLK_MQ_F_TAG_HCTX_SHARED is set gives
something like:

root@debian:/home/john# more /sys/kernel/debug/block/sda/hctx0/flags
alloc_policy=FIFO SHOULD_MERGE|TAG_QUEUE_SHARED|3

Add the decoding for that flag.

Fixes: 32bc15afed04b ("blk-mq: Facilitate a shared sbitmap per tagset")
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Make sure that bdgrab() is done on the 'block_device' instance before
referring to it for avoiding use-after-free.

Cc: <stable@vger.kernel.org>
Reported-by: syzbot+825f0f9657d4e528046e@syzkaller.appspotmail.com
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

BFQ computes number of tags it allows to be allocated for each request type
based on tag bitmap. However it uses 1 << bitmap.shift as number of
available tags which is wrong. 'shift' is just an internal bitmap value
containing logarithm of how many bits bitmap uses in each bitmap word.
Thus number of tags allowed for some request types can be far to low.
Use proper bitmap.depth which has the number of tags instead.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

When initializing iocost for a queue, its rqos should be registered before
the blkcg policy is activated to allow policy data initiailization to lookup
the associated ioc. This unfortunately means that the rqos methods can be
called on bios before iocgs are attached to all existing blkgs.

While the race is theoretically possible on ioc_rqos_throttle(), it mostly
happened in ioc_rqos_merge() due to the difference in how they lookup ioc.
The former determines it from the passed in @rqos and then bails before
dereferencing iocg if the looked up ioc is disabled, which most likely is
the case if initialization is still in progress. The latter looked up ioc by
dereferencing the possibly NULL iocg making it a lot more prone to actually
triggering the bug.

* Make ioc_rqos_merge() use the same method as ioc_rqos_throttle() to look
  up ioc for consistency.

* Make ioc_rqos_throttle() and ioc_rqos_merge() test for NULL iocg before
  dereferencing it.

* Explain the danger of NULL iocgs in blk_iocost_init().

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jonathan Lemon <bsd@fb.com>
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Jens Axboe <axboe@kernel.dk>