Request-based devices (dm-multipath) queue I/O in blk-mq on noflush
suspends. Any queued IO will make it impossible to freeze the queue. If
a process attempts to update the queue limits while there is queued IO,
it can be get stuck holding the limits lock, while unable to freeze the
queue. If device-mapper then attempts to update the limits during a
table swap, it will deadlock trying to grab the limits lock while making
it impossible to flush the IO.

Disallow updating the queue limits during a table swap, when updating an
immutable request-based dm device (dm-multipath) during a noflush
suspend. It is userspace's responsibility to make sure that the new
table uses the same limits as the existing table if it asks for a
noflush suspend.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Pull device mapper updates from Mikulas Patocka:

 - fix checking for request-based stackable devices (dm-table)

 - fix corrupt_bio_byte setup checks (dm-flakey)

 - add support for resync w/o metadata devices (dm raid)

 - small code simplification (dm, dm-mpath, vm-vdo, dm-raid)

 - remove support for asynchronous hashes (dm-verity)

 - close smatch warning (dm-zoned-target)

 - update the documentation and enable inline-crypto passthrough
   (dm-thin)

* tag 'for-6.17/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: set DM_TARGET_PASSES_CRYPTO feature for dm-thin
  dm-thin: update the documentation
  dm-raid: do not include dm-core.h
  vdo: omit need_resched() before cond_resched()
  md: dm-zoned-target: Initialize return variable r to avoid uninitialized use
  dm-verity: remove support for asynchronous hashes
  dm-mpath: don't print the "loaded" message if registering fails
  dm-mpath: make dm_unregister_path_selector return void
  dm: ima: avoid extra calls to strlen()
  dm: Simplify dm_io_complete()
  dm: Remove unnecessary return in dm_zone_endio()
  dm raid: add support for resync w/o metadata devices
  dm-flakey: Fix corrupt_bio_byte setup checks
  dm-table: fix checking for rq stackable devices

The unmap write zeroes limits have been set to the stacking queue limits
by default in blk_set_stacking_limits() and blk_stack_limits(), but it
should be cleared if any underlying device does not support it.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/20250619111806.3546162-6-yi.zhang@huaweicloud.com
Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Due to the semantics of iterate_devices(), the current code allows a
request-based dm table as long as it includes one request-stackable
device. It is supposed to only allow tables where there are no
non-request-stackable devices.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Pull device mapper updates from Mikulas Patocka:

 - better error handling when reloading a table

 - use use generic disable_* functions instead of open coding them

 - lock queue limits when reading them

 - remove unneeded kvfree from alloc_targets

 - fix BLK_FEAT_ATOMIC_WRITES

 - pass through operations on wrapped inline crypto keys

 - dm-verity:
     - use softirq context only when !need_resched()
     - fix a memory leak if some arguments are specified multiple times

 - dm-mpath:
    - interface for explicit probing of active paths
    - replace spin_lock_irqsave with spin_lock_irq

 - dm-delay: don't busy-wait in kthread

 - dm-bufio: remove maximum age based eviction

 - dm-flakey: various fixes

 - vdo indexer: don't read request structure after enqueuing

 - dm-zone: Use bdev_*() helper functions where applicable

 - dm-mirror: fix a tiny race condition

 - dm-stripe: small code cleanup

* tag 'for-6.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (29 commits)
  dm-stripe: small code cleanup
  dm-verity: fix a memory leak if some arguments are specified multiple times
  dm-mirror: fix a tiny race condition
  dm-table: check BLK_FEAT_ATOMIC_WRITES inside limits_lock
  dm mpath: replace spin_lock_irqsave with spin_lock_irq
  dm-mpath: Don't grab work_mutex while probing paths
  dm-zone: Use bdev_*() helper functions where applicable
  dm vdo indexer: don't read request structure after enqueuing
  dm: pass through operations on wrapped inline crypto keys
  blk-crypto: export wrapped key functions
  dm-table: Set BLK_FEAT_ATOMIC_WRITES for target queue limits
  dm mpath: Interface for explicit probing of active paths
  dm: Allow .prepare_ioctl to handle ioctls directly
  dm-flakey: make corrupting read bios work
  dm-flakey: remove useless ERROR_READS check in flakey_end_io
  dm-flakey: error all IOs when num_features is absent
  dm-flakey: Clean up parsing messages
  dm: remove unneeded kvfree from alloc_targets
  dm-bufio: remove maximum age based eviction
  dm-verity: use softirq context only when !need_resched()
  ...

dm_set_device_limits() should check q->limits.features for
BLK_FEAT_ATOMIC_WRITES while holding q->limits_lock, like it does for
the rest of the queue limits.

Fixes: b7c18b17a173 ("dm-table: Set BLK_FEAT_ATOMIC_WRITES for target queue limits")
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Improve code readability by using bdev_is_zone_aligned() and
bdev_offset_from_zone_start() where applicable. No functionality
has been changed.

This patch is a reworked version of a patch from Pankaj Raghav.

See also https://lore.kernel.org/linux-block/20220923173618.6899-11-p.raghav@samsung.com/.

Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Make the device-mapper layer pass through the derive_sw_secret,
import_key, generate_key, and prepare_key blk-crypto operations when all
underlying devices support hardware-wrapped inline crypto keys and are
passing through inline crypto support.

Commit ebc4176551cd ("blk-crypto: add basic hardware-wrapped key
support") already made BLK_CRYPTO_KEY_TYPE_HW_WRAPPED be passed through
in the same way that the other crypto capabilities are.  But the wrapped
key support also includes additional operations in blk_crypto_ll_ops,
and the dm layer needs to implement those to pass them through.
derive_sw_secret is needed by fscrypt, while the other operations are
needed for the new blk-crypto ioctls to work on device-mapper devices
and not just the raw partitions.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

The blammed commit copied to argv the size of the reallocated argv,
instead of the size of the old_argv, thus reading and copying from
past the old_argv allocated memory.

Following BUG_ON was hit:
[    3.038929][    T1] kernel BUG at lib/string_helpers.c:1040!
[    3.039147][    T1] Internal error: Oops - BUG: 00000000f2000800 [#1]  SMP
...
[    3.056489][    T1] Call trace:
[    3.056591][    T1]  __fortify_panic+0x10/0x18 (P)
[    3.056773][    T1]  dm_split_args+0x20c/0x210
[    3.056942][    T1]  dm_table_add_target+0x13c/0x360
[    3.057132][    T1]  table_load+0x110/0x3ac
[    3.057292][    T1]  dm_ctl_ioctl+0x424/0x56c
[    3.057457][    T1]  __arm64_sys_ioctl+0xa8/0xec
[    3.057634][    T1]  invoke_syscall+0x58/0x10c
[    3.057804][    T1]  el0_svc_common+0xa8/0xdc
[    3.057970][    T1]  do_el0_svc+0x1c/0x28
[    3.058123][    T1]  el0_svc+0x50/0xac
[    3.058266][    T1]  el0t_64_sync_handler+0x60/0xc4
[    3.058452][    T1]  el0t_64_sync+0x1b0/0x1b4
[    3.058620][    T1] Code: f800865e a9bf7bfd 910003fd 941f48aa (d4210000)
[    3.058897][    T1] ---[ end trace 0000000000000000 ]---
[    3.059083][    T1] Kernel panic - not syncing: Oops - BUG: Fatal exception

Fix it by copying the size of src, and not the size of dst, as it was.

Fixes: 5a2a6c428190 ("dm: always update the array size in realloc_argv on success")
Cc: stable@vger.kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Feature flag BLK_FEAT_ATOMIC_WRITES is not being properly set for the
target queue limits, and this means that atomic writes are not being
enabled for any dm personalities.

When calling dm_set_device_limits() -> blk_stack_limits() ->
... -> blk_stack_atomic_writes_limits(), the bottom device limits
(which corresponds to intermediate target queue limits) does not have
BLK_FEAT_ATOMIC_WRITES set, and so atomic writes can never be enabled.

Typically such a flag would be inherited from the stacked device in
dm_set_device_limits() -> blk_stack_limits() via BLK_FEAT_INHERIT_MASK,
but BLK_FEAT_ATOMIC_WRITES is not inherited as it's preferred to manually
enable on a per-personality basis.

Set BLK_FEAT_ATOMIC_WRITES manually for the intermediate target queue
limits from the stacked device to get atomic writes working.

Fixes: 3194e36488e2 ("dm-table: atomic writes support")
Cc: stable@vger.kernel.org	# v6.14
Signed-off-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>