'open_mutex' of gendisk is used to protect open/close block devices. But
in bd_link_disk_holder(), it is used to protect the creation of symlink
between holding disk and slave bdev, which introduces some issues.

When bd_link_disk_holder() is called, the driver is usually in the process
of initialization/modification and may suspend submitting io. At this
time, any io hold 'open_mutex', such as scanning partitions, can cause
deadlocks. For example, in raid:

T1                              T2
bdev_open_by_dev
 lock open_mutex [1]
 ...
  efi_partition
  ...
   md_submit_bio
				md_ioctl mddev_syspend
				  -> suspend all io
				 md_add_new_disk
				  bind_rdev_to_array
				   bd_link_disk_holder
				    try lock open_mutex [2]
    md_handle_request
     -> wait mddev_resume

T1 scan partition, T2 add a new device to raid. T1 waits for T2 to resume
mddev, but T2 waits for open_mutex held by T1. Deadlock occurs.

Fix it by introducing a local mutex 'blk_holder_mutex' to replace
'open_mutex'.

Fixes: 1b0a2d95 ("md: use new apis to suspend array for ioctls involed array reconfiguration")
Reported-by: mgperkow@gmail.com
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218459Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240221090122.1281868-1-linan666@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

The block zone code does not use RB-tree. So remove the include of
linux/rbtree.h as it is not needed.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240222131724.1803520-2-dlemoal@kernel.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Device mapper may create a non-zoned mapped device out of a zoned device
(e.g., the dm-zoned target). In such case, some queue limit such as the
max_zone_append_sectors and zone_write_granularity endup being non zero
values for a block device that is not zoned. Avoid this by clearing
these limits in blk_stack_limits() when the stacked zoned limit is
false.

Fixes: 3093a479 ("block: inherit the zoned characteristics in blk_stack_limits")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240222131724.1803520-1-dlemoal@kernel.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Since commit 8b631f9c ("null_blk: remove the bio based I/O path"),
struct nullb members queue_depth and nr_queues are only ever written, so
delete them.

With that, null_exit_hctx() can also be deleted.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240222083420.6026-1-john.g.garry@oracle.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Remove pkt_init_queue and just pass the two parameters directly to
blk_alloc_disk.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240222073647.3776769-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

The two users can get the private data from the gendisk with one less
pointer dereference, and we can drop the useless q parameter from
pkt_make_request_write.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240222073647.3776769-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Don't set the default max_segment_size value when a virt_boundary is
used.

Fixes: d690cb8a ("block: add an API to atomically update queue limits")
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20240221125010.3609444-1-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the queue limits directly to blk_mq_alloc_disk instead of
setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240220093248.3290292-6-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

null_gendisk_register isn't a very useful abstraction given that it
doesn't even allocate the gendisk.  Merge it into the only caller
instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240220093248.3290292-5-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Move the tagset initialization out of null_add_dev into a new
null_setup_tagset helper, and move the shared vs local differences
out of null_init_tag_set into the callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240220093248.3290292-4-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Otherwise it will be reset to the always same value when initializing a
device using the shared tag_set.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240220093248.3290292-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

The bio based I/O path complicates null_blk and also make various
data structures, including the per-command one way bigger than
required for the main request based interface.   As the bio-based
path is mostly used by stacking drivers and simple memory based
drivers, and brd is a good example driver for the latter there is
no need to have a bio based path in null_blk.  Remove the path
to simplify the driver and make future block layer API changes
simpler by not having to deal with the complex two API setup in
null_blk.

Note that the queue_mode field in struct nullb_device is kept as
that is simpler than having two different places to check the
value and fully open coding the debugfs helpers as the existing
ones won't work without a named struct member.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240220093248.3290292-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the queue limit set at initialization time directly to
blk_mq_alloc_disk instead of updating it right after the allocation.

This requires refactoring the code a bit so that what was mmc_setup_queue
before also allocates the gendisk now and actually sets all limits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20240215070300.2200308-18-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the limits ublk imposes directly to blk_mq_alloc_disk instead of
setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-17-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the few limits scm_block imposes directly to blk_mq_alloc_disk
instead of setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-16-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the few limits ubiblock imposes directly to blk_mq_alloc_disk
instead of setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Link: https://lore.kernel.org/r/20240215070300.2200308-15-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the few limits mtd_blkdevs imposes directly to blk_mq_alloc_disk
instead of setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-14-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the few limits mspro_block imposes directly to blk_mq_alloc_disk
instead of setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-13-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the few limits ms_block imposes directly to blk_mq_alloc_disk
instead of setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-12-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the few limits gdrom imposes directly to blk_mq_alloc_disk instead
of setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-11-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the few limits sunvdc imposes directly to blk_mq_alloc_disk instead
of setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-10-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the limits rnbd-clt imposes directly to blk_mq_alloc_disk instead
of setting them one at a time.

While at it don't set an explicit number of discard segments, as 1 is
the default (which most drivers rely on).
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20240215070300.2200308-9-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the limits rbd imposes directly to blk_mq_alloc_disk instead
of setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-8-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the few limits ps3disk imposes directly to blk_mq_alloc_disk instead
of setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-7-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the few limits nbd imposes directly to blk_mq_alloc_disk instead
of setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-6-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the few limits mtip imposes directly to blk_mq_alloc_disk instead
of setting them one at a time and drop the pointless setting of a io_min
that is equal to the physical block size.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-5-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the few limits floppy imposes directly to blk_mq_alloc_disk instead
of setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Denis Efremov <efremov@linux.com>
Link: https://lore.kernel.org/r/20240215070300.2200308-4-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the few limits aoe imposes directly to blk_mq_alloc_disk instead
of setting them one at a time and improve the way the default
max_hw_sectors is initialized while we're at it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the few limits ubd imposes directly to blk_mq_alloc_disk instead
of setting them one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the queue limits directly to blk_alloc_disk instead of setting them
one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20240215071055.2201424-10-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the queue limits directly to blk_alloc_disk instead of setting them
one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20240215071055.2201424-9-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the queue limits directly to blk_alloc_disk instead of setting them
one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20240215071055.2201424-8-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the queue limits directly to blk_alloc_disk instead of setting them
one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20240215071055.2201424-7-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the queue limits directly to blk_alloc_disk instead of setting them
one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20240215071055.2201424-6-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the queue limits directly to blk_alloc_disk instead of setting them
one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20240215071055.2201424-5-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the queue limits directly to blk_alloc_disk instead of setting them
one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20240215071055.2201424-4-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass the queue limits directly to blk_alloc_disk instead of setting them
one at a time.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20240215071055.2201424-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pass a queue_limits to blk_alloc_disk and apply it if non-NULL.  This
will allow allocating queues with valid queue limits instead of setting
the values one at a time later.

Also change blk_alloc_disk to return an ERR_PTR instead of just NULL
which can't distinguish errors.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20240215071055.2201424-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

nla_nest_start() may fail and return NULL. Insert a check and set errno
based on other call sites within the same source code.
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Fixes: 47d902b9 ("nbd: add a status netlink command")
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240218042534.it.206-kees@kernel.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Merge tag 'md-6.9-20240216' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into for-6.9/block

Pull MD changes from Song:

"1. Cleanup redundant checks, by Yu Kuai.
 2. Remove deprecated headers, by Marc Zyngier and Song Liu.
 3. Concurrency fixes, by Li Lingfeng.
 4. Memory leak fix, by Li Nan."

* tag 'md-6.9-20240216' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  md: fix kmemleak of rdev->serial
  md/multipath: Remove md-multipath.h
  md/linear: Get rid of md-linear.h
  md: use RCU lock to protect traversal in md_spares_need_change()
  md: get rdev->mddev with READ_ONCE()
  md: remove redundant md_wakeup_thread()
  md: remove redundant check of 'mddev->sync_thread'