Don't error out if the dasd_biodasdinfo symbol is not available.

Cc: stable@vger.kernel.org
Fixes: 26d7e28e3820 ("s390/dasd: remove ioctl_by_bdev calls")
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

mdadm relies on the fact that deleting an invalid partition returns
-ENXIO or -ENOTTY to detect if a block device is a partition or a
whole device.

Fixes: 08fc1ab6d748 ("block: fix locking in bdev_del_partition")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We need to hold the whole device bd_mutex to protect against
other thread concurrently deleting out partition before we get
to it, and thus causing a use after free.

Fixes: cddae808aeb7 ("block: pass a hd_struct to delete_partition")
Reported-by: syzbot+6448f3c229bc52b82f69@syzkaller.appspotmail.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Commit e8c7d14ac6c3 ("block: revert back to synchronous request_queue removal")
stops to release request queue from wq context because that commit
supposed all blk_put_queue() is called in context which is allowed
to sleep. However, this assumption isn't true because we release disk's
reference in partition's percpu_ref's ->release() which doesn't allow
to sleep, because the ->release() is run via call_rcu().

Fixes this issue by moving put disk reference into hd_struct_free_work()

Fixes: e8c7d14ac6c3 ("block: revert back to synchronous request_queue removal")
Reported-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

In theory, when GENHD_FL_NO_PART_SCAN is set, no partitions can be created
on one disk. However, ioctl(BLKPG, BLKPG_ADD_PARTITION) doesn't check
GENHD_FL_NO_PART_SCAN, so partitions still can be added even though
GENHD_FL_NO_PART_SCAN is set.

So far blk_drop_partitions() only removes partitions when disk_part_scan_enabled()
return true. This way can make ghost partition on loop device after changing/clearing
FD in case that PARTSCAN is disabled, such as partitions can be added
via 'parted' on loop disk even though GENHD_FL_NO_PART_SCAN is set.

Fix this issue by always removing partitions in blk_drop_partitions(), and
this way is correct because the current code supposes that no partitions
can be added in case of GENHD_FL_NO_PART_SCAN.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull block fixes from Jens Axboe:

 - Use import_uuid() where appropriate (Andy)

 - bcache fixes (Coly, Mauricio, Zhiqiang)

 - blktrace sparse warnings fix (Jan)

 - blktrace concurrent setup fix (Luis)

 - blkdev_get use-after-free fix (Jason)

 - Ensure all blk-mq maps are updated (Weiping)

 - Loop invalidate bdev fix (Zheng)

* tag 'block-5.8-2020-06-19' of git://git.kernel.dk/linux-block:
  block: make function 'kill_bdev' static
  loop: replace kill_bdev with invalidate_bdev
  partitions/ldm: Replace uuid_copy() with import_uuid() where it makes sense
  block: update hctx map when use multiple maps
  blktrace: Avoid sparse warnings when assigning q->blk_trace
  blktrace: break out of blktrace setup on concurrent calls
  block: Fix use-after-free in blkdev_get()
  trace/events/block.h: drop kernel-doc for dropped function parameter
  blk-mq: Remove redundant 'return' statement
  bcache: pr_info() format clean up in bcache_device_init()
  bcache: use delayed kworker fo asynchronous devices registration
  bcache: check and adjust logical block size for backing devices
  bcache: fix potential deadlock problem in btree_gc_coalesce

There is a specific API to treat raw data as UUID, i.e. import_uuid().
Use it instead of uuid_copy() with explicit casting.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://github.com/KSPP/linux/issues/21

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Pull block driver updates from Jens Axboe:
 "On top of the core changes, here are the block driver changes for this
  merge window:

   - NVMe changes:
        - NVMe over Fibre Channel protocol updates, which also reach
          over to drivers/scsi/lpfc (James Smart)
        - namespace revalidation support on the target (Anthony
          Iliopoulos)
        - gcc zero length array fix (Arnd Bergmann)
        - nvmet cleanups (Chaitanya Kulkarni)
        - misc cleanups and fixes (me, Keith Busch, Sagi Grimberg)
        - use a SRQ per completion vector (Max Gurtovoy)
        - fix handling of runtime changes to the queue count (Weiping
          Zhang)
        - t10 protection information support for nvme-rdma and
          nvmet-rdma (Israel Rukshin and Max Gurtovoy)
        - target side AEN improvements (Chaitanya Kulkarni)
        - various fixes and minor improvements all over, icluding the
          nvme part of the lpfc driver"

   - Floppy code cleanup series (Willy, Denis)

   - Floppy contention fix (Jiri)

   - Loop CONFIGURE support (Martijn)

   - bcache fixes/improvements (Coly, Joe, Colin)

   - q->queuedata cleanups (Christoph)

   - Get rid of ioctl_by_bdev (Christoph, Stefan)

   - md/raid5 allocation fixes (Coly)

   - zero length array fixes (Gustavo)

   - swim3 task state fix (Xu)"

* tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-block: (166 commits)
  bcache: configure the asynchronous registertion to be experimental
  bcache: asynchronous devices registration
  bcache: fix refcount underflow in bcache_device_free()
  bcache: Convert pr_<level> uses to a more typical style
  bcache: remove redundant variables i and n
  lpfc: Fix return value in __lpfc_nvme_ls_abort
  lpfc: fix axchg pointer reference after free and double frees
  lpfc: Fix pointer checks and comments in LS receive refactoring
  nvme: set dma alignment to qword
  nvmet: cleanups the loop in nvmet_async_events_process
  nvmet: fix memory leak when removing namespaces and controllers concurrently
  nvmet-rdma: add metadata/T10-PI support
  nvmet: add metadata support for block devices
  nvmet: add metadata/T10-PI support
  nvme: add Metadata Capabilities enumerations
  nvmet: rename nvmet_check_data_len to nvmet_check_transfer_len
  nvmet: rename nvmet_rw_len to nvmet_rw_data_len
  nvmet: add metadata characteristics for a namespace
  nvme-rdma: add metadata/T10-PI support
  nvme-rdma: introduce nvme_rdma_sgl structure
  ...