Pull device mapper fixes from Mikulas Patocka:

 - dm-array fixes

 - dm-verity forward error correction fixes

 - remove the flag DM_TARGET_PASSES_INTEGRITY from dm-ebs

 - dm-thin RCU list fix

* tag 'for-6.13/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm thin: make get_first_thin use rcu-safe list first function
  dm-ebs: don't set the flag DM_TARGET_PASSES_INTEGRITY
  dm-verity FEC: Avoid copying RS parity bytes twice.
  dm-verity FEC: Fix RS FEC repair for roots unaligned to block size (take 2)
  dm array: fix cursor index when skipping across block boundaries
  dm array: fix unreleased btree blocks on closing a faulty array cursor
  dm array: fix releasing a faulty array block twice in dm_array_cursor_end

The documentation in rculist.h explains the absence of list_empty_rcu()
and cautions programmers against relying on a list_empty() ->
list_first() sequence in RCU safe code.  This is because each of these
functions performs its own READ_ONCE() of the list head.  This can lead
to a situation where the list_empty() sees a valid list entry, but the
subsequent list_first() sees a different view of list head state after a
modification.

In the case of dm-thin, this author had a production box crash from a GP
fault in the process_deferred_bios path.  This function saw a valid list
head in get_first_thin() but when it subsequently dereferenced that and
turned it into a thin_c, it got the inside of the struct pool, since the
list was now empty and referring to itself.  The kernel on which this
occurred printed both a warning about a refcount_t being saturated, and
a UBSAN error for an out-of-bounds cpuid access in the queued spinlock,
prior to the fault itself.  When the resulting kdump was examined, it
was possible to see another thread patiently waiting in thin_dtr's
synchronize_rcu.

The thin_dtr call managed to pull the thin_c out of the active thins
list (and have it be the last entry in the active_thins list) at just
the wrong moment which lead to this crash.

Fortunately, the fix here is straight forward.  Switch get_first_thin()
function to use list_first_or_null_rcu() which performs just a single
READ_ONCE() and returns NULL if the list is already empty.

This was run against the devicemapper test suite's thin-provisioning
suites for delete and suspend and no regressions were observed.

Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Fixes: b10ebd34ccca ("dm thin: fix rcu_read_lock being held in code that can sleep")
Cc: stable@vger.kernel.org
Acked-by: Ming-Hung Tsai <mtsai@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Pull device mapper updates from Mikulas Patocka:

 - remove unused functions and variables

 - rate-limit error messages in syslog

 - fix typo

 - remove u64 alignment requirement for murmurhash

 - reset bi_ioprio to the default for dm-vdo

 - add support for get_unique_id

 - Add missing destroy_work_on_stack() to dm-thin

 - use kmalloc to allocate power-of-two sized buffers in bufio

* tag 'for-6.13/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm-verity: remove the unused "data_start" variable
  dm-bufio: use kmalloc to allocate power-of-two sized buffers
  dm thin: Add missing destroy_work_on_stack()
  dm: add support for get_unique_id
  dm vdo: fix function doc comment formatting
  dm vdo int-map: remove unused parameters
  dm-vdo: reset bi_ioprio to the default value when the bio is reset
  dm-vdo murmurhash: remove u64 alignment requirement
  dm: Fix typo in error message
  dm ioctl: rate limit a couple of ioctl based error messages
  dm vdo: Remove unused uds_compute_index_size
  dm vdo: Remove unused functions
  dm: zoned: Remove unused functions
  dm: Remove unused dm_table_bio_based
  dm: Remove unused dm_set_md_type
  dm cache: Remove unused functions in bio-prison-v1
  dm cache: Remove unused dm_cache_size
  dm cache: Remove unused dm_cache_dump
  dm cache: Remove unused btracker_nr_writebacks_queued

This commit add missed destroy_work_on_stack() operations for pw->worker in
pool_work_wait().

Fixes: e7a3e871d895 ("dm thin: cleanup noflush_work to use a proper completion")
Cc: stable@vger.kernel.org
Signed-off-by: Yuan Can <yuancan@huawei.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Add a helper to get the queue_limits from the bdev without having to
poke into the request_queue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20241029141937.249920-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Use ERR_CAST() as it is designed for casting an error pointer to
another type.

This macro utilizes the __force and __must_check modifiers, which instruct
the compiler to verify for errors at the locations where it is employed.

Signed-off-by: Yuesong Li <liyuesong@vivo.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Remove use of the blk_limits_io_{min,opt} and assign the values directly
to the queue_limits structure.  For the io_opt this is a completely
mechanical change, for io_min it removes flooring the limit to the
physical and logical block size in the particular caller.  But as
blk_validate_limits will do the same later when actually applying the
limits, there still is no change in overall behavior.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Pull device mapper fixes from Mike Snitzer:

 - Fix DM discard regressions due to DM core switching over to using
   queue_limits_set() without DM core and targets first being updated to
   set (and stack) discard limits in terms of max_hw_discard_sectors and
   not max_discard_sectors

 - Fix stable@ DM integrity discard support to set device's
   discard_granularity limit to the device's logical block size

* tag 'for-6.10/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: always manage discard support in terms of max_hw_discard_sectors
  dm-integrity: set discard_granularity to logical block size

Commit 4f563a64732d ("block: add a max_user_discard_sectors queue
limit") changed block core to set max_discard_sectors to:
 min(lim->max_hw_discard_sectors, lim->max_user_discard_sectors)

Since commit 1c0e720228ad ("dm: use queue_limits_set") it was reported
dm-thinp was failing in a few fstests (generic/347 and generic/405)
with the first WARN_ON_ONCE in dm_cell_key_has_valid_range() being
reported, e.g.:
WARNING: CPU: 1 PID: 30 at drivers/md/dm-bio-prison-v1.c:128 dm_cell_key_has_valid_range+0x3d/0x50

blk_set_stacking_limits() sets max_user_discard_sectors to UINT_MAX,
so given how block core now sets max_discard_sectors (detailed above)
it follows that blk_stack_limits() stacks up the underlying device's
max_hw_discard_sectors and max_discard_sectors is set to match it. If
max_hw_discard_sectors exceeds dm's BIO_PRISON_MAX_RANGE, then
dm_cell_key_has_valid_range() will trigger the warning with:
WARN_ON_ONCE(key->block_end - key->block_begin > BIO_PRISON_MAX_RANGE)

Aside from this warning, the discard will fail.  Fix this and other DM
issues by governing discard support in terms of max_hw_discard_sectors
instead of max_discard_sectors.

Reported-by: Theodore Ts'o <tytso@mit.edu>
Fixes: 1c0e720228ad ("dm: use queue_limits_set")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

Use bio_list_merge_init instead of open coding bio_list_merge and
bio_list_init.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240328084147.2954434-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>