Pull block updates from Jens Axboe:

 - NVMe pull request via Keith:
     - FC target fixes (Daniel)
     - Authentication fixes and updates (Martin, Chris)
     - Admin controller handling (Kamaljit)
     - Target lockdep assertions (Max)
     - Keep-alive updates for discovery (Alastair)
     - Suspend quirk (Georg)

 - MD pull request via Yu:
     - Add support for a lockless bitmap.

       A key feature for the new bitmap are that the IO fastpath is
       lockless. If a user issues lots of write IO to the same bitmap
       bit in a short time, only the first write has additional overhead
       to update bitmap bit, no additional overhead for the following
       writes.

       By supporting only resync or recover written data, means in the
       case creating new array or replacing with a new disk, there is no
       need to do a full disk resync/recovery.

 - Switch ->getgeo() and ->bios_param() to using struct gendisk rather
   than struct block_device.

 - Rust block changes via Andreas. This series adds configuration via
   configfs and remote completion to the rnull driver. The series also
   includes a set of changes to the rust block device driver API: a few
   cleanup patches, and a few features supporting the rnull changes.

   The series removes the raw buffer formatting logic from
   `kernel::block` and improves the logic available in `kernel::string`
   to support the same use as the removed logic.

 - floppy arch cleanups

 - Reduce the number of dereferencing needed for ublk commands

 - Restrict supported sockets for nbd. Mostly done to eliminate a class
   of issues perpetually reported by syzbot, by using nonsensical socket
   setups.

 - A few s390 dasd block fixes

 - Fix a few issues around atomic writes

 - Improve DMA interation for integrity requests

 - Improve how iovecs are treated with regards to O_DIRECT aligment
   constraints.

   We used to require each segment to adhere to the constraints, now
   only the request as a whole needs to.

 - Clean up and improve p2p support, enabling use of p2p for metadata
   payloads

 - Improve locking of request lookup, using SRCU where appropriate

 - Use page references properly for brd, avoiding very long RCU sections

 - Fix ordering of recursively submitted IOs

 - Clean up and improve updating nr_requests for a live device

 - Various fixes and cleanups

* tag 'for-6.18/block-20250929' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (164 commits)
  s390/dasd: enforce dma_alignment to ensure proper buffer validation
  s390/dasd: Return BLK_STS_INVAL for EINVAL from do_dasd_request
  ublk: remove redundant zone op check in ublk_setup_iod()
  nvme: Use non zero KATO for persistent discovery connections
  nvmet: add safety check for subsys lock
  nvme-core: use nvme_is_io_ctrl() for I/O controller check
  nvme-core: do ioccsz/iorcsz validation only for I/O controllers
  nvme-core: add method to check for an I/O controller
  blk-cgroup: fix possible deadlock while configuring policy
  blk-mq: fix null-ptr-deref in blk_mq_free_tags() from error path
  blk-mq: Fix more tag iteration function documentation
  selftests: ublk: fix behavior when fio is not installed
  ublk: don't access ublk_queue in ublk_unmap_io()
  ublk: pass ublk_io to __ublk_complete_rq()
  ublk: don't access ublk_queue in ublk_need_complete_req()
  ublk: don't access ublk_queue in ublk_check_commit_and_fetch()
  ublk: don't pass ublk_queue to ublk_fetch()
  ublk: don't access ublk_queue in ublk_config_io_buf()
  ublk: don't access ublk_queue in ublk_check_fetch_buf()
  ublk: pass q_id and tag to __ublk_check_and_get_req()
  ...

Pull rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Derive 'Zeroable' for all structs and unions generated by 'bindgen'
     where possible and corresponding cleanups. To do so, add the
     'pin-init' crate as a dependency to 'bindings' and 'uapi'.

     It also includes its first use in the 'cpufreq' module, with more
     to come in the next cycle.

   - Add warning to the 'rustdoc' target to detect broken 'srctree/'
     links and fix existing cases.

   - Remove support for unused (since v6.16) host '#[test]'s,
     simplifying the 'rusttest' target. Tests should generally run
     within KUnit.

  'kernel' crate:

   - Add 'ptr' module with a new 'Alignment' type, which is always a
     power of two and is used to validate that a given value is a valid
     alignment and to perform masking and alignment operations:

         // Checked at build time.
         assert_eq!(Alignment::new::<16>().as_usize(), 16);

         // Checked at runtime.
         assert_eq!(Alignment::new_checked(15), None);

         assert_eq!(Alignment::of::<u8>().log2(), 0);

         assert_eq!(0x25u8.align_down(Alignment::new::<0x10>()), 0x20);
         assert_eq!(0x5u8.align_up(Alignment::new::<0x10>()), Some(0x10));
         assert_eq!(u8::MAX.align_up(Alignment::new::<0x10>()), None);

     It also includes its first use in Nova.

   - Add 'core::mem::{align,size}_of{,_val}' to the prelude, matching
     Rust 1.80.0.

   - Keep going with the steps on our migration to the standard library
     'core::ffi::CStr' type (use 'kernel::{fmt, prelude::fmt!}' and use
     upstream method names).

   - 'error' module: improve 'Error::from_errno' and 'to_result'
     documentation, including examples/tests.

   - 'sync' module: extend 'aref' submodule documentation now that it
     exists, and more updates to complete the ongoing move of 'ARef' and
     'AlwaysRefCounted' to 'sync::aref'.

   - 'list' module: add an example/test for 'ListLinksSelfPtr' usage.

   - 'alloc' module:

      - Implement 'Box::pin_slice()', which constructs a pinned slice of
        elements.

      - Provide information about the minimum alignment guarantees of
        'Kmalloc', 'Vmalloc' and 'KVmalloc'.

      - Take minimum alignment guarantees of allocators for
        'ForeignOwnable' into account.

      - Remove the 'allocator_test' (including 'Cmalloc').

      - Add doctest for 'Vec::as_slice()'.

      - Constify various methods.

   - 'time' module:

      - Add methods on 'HrTimer' that can only be called with exclusive
        access to an unarmed timer, or from timer callback context.

      - Add arithmetic operations to 'Instant' and 'Delta'.

      - Add a few convenience and access methods to 'HrTimer' and
        'Instant'.

  'macros' crate:

   - Reduce collections in 'quote!' macro.

  And a few other cleanups and improvements"

* tag 'rust-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (58 commits)
  gpu: nova-core: use Alignment for alignment-related operations
  rust: add `Alignment` type
  rust: macros: reduce collections in `quote!` macro
  rust: acpi: use `core::ffi::CStr` method names
  rust: of: use `core::ffi::CStr` method names
  rust: net: use `core::ffi::CStr` method names
  rust: miscdevice: use `core::ffi::CStr` method names
  rust: kunit: use `core::ffi::CStr` method names
  rust: firmware: use `core::ffi::CStr` method names
  rust: drm: use `core::ffi::CStr` method names
  rust: cpufreq: use `core::ffi::CStr` method names
  rust: configfs: use `core::ffi::CStr` method names
  rust: auxiliary: use `core::ffi::CStr` method names
  drm/panic: use `core::ffi::CStr` method names
  rust: device: use `kernel::{fmt,prelude::fmt!}`
  rust: sync: use `kernel::{fmt,prelude::fmt!}`
  rust: seq_file: use `kernel::{fmt,prelude::fmt!}`
  rust: kunit: use `kernel::{fmt,prelude::fmt!}`
  rust: file: use `kernel::{fmt,prelude::fmt!}`
  rust: device: use `kernel::{fmt,prelude::fmt!}`
  ...

Reduce coupling to implementation details of the formatting machinery by
avoiding direct use for `core`'s formatting traits and macros.

Suggested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/Custom.20formatting/with/516476467
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Currently there's a custom reference counting in `block::mq`, which uses
`AtomicU64` Rust atomics, and this type doesn't exist on some 32-bit
architectures. We cannot just change it to use 32-bit atomics, because
doing so will make it vulnerable to refcount overflow. So switch it to
use the kernel refcount `kernel::sync::Refcount` instead.

There is an operation needed by `block::mq`, atomically decreasing
refcount from 2 to 0, which is not available through refcount.h, so
I exposed `Refcount::as_atomic` which allows accessing the refcount
directly.

[boqun: Adopt the LKMM atomic API]
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/r/20250723233312.3304339-5-gary@kernel.org

This `srctree/` link pointed to a file with an underscore, but the header
used a dash instead.

Thus fix it.

This cleans a future warning that will check our `srctree/` links.

Cc: stable@vger.kernel.org
Fixes: 3253aba3408a ("rust: block: introduce `kernel::block::mq` module")
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Allow users of rust block device driver API to schedule completion of
requests via `blk_mq_complete_request_remote`.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250902-rnull-up-v6-16-v7-16-b5212cc89b98@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Add code block quotes to a safety comment.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250902-rnull-up-v6-16-v7-15-b5212cc89b98@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Allow users of the rust block device driver API to install private data in
the `GenDisk` structure.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250902-rnull-up-v6-16-v7-14-b5212cc89b98@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Allow rust null block devices to be configured and instantiated via
`configfs`.

Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250902-rnull-up-v6-16-v7-13-b5212cc89b98@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Remove the trait bound `T:Operations` from `mq::Request`. The bound is not
required, so remove it to reduce complexity.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250902-rnull-up-v6-16-v7-10-b5212cc89b98@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>