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From: Andreas Hindborg <a.hindborg@kernel.org>
To: "Boqun Feng" <boqun.feng@gmail.com>,
	"Jens Axboe" <axboe@kernel.dk>, "Miguel Ojeda" <ojeda@kernel.org>,
	"Gary Guo" <gary@garyguo.net>,
	"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
	"Benno Lossin" <lossin@kernel.org>,
	"Alice Ryhl" <aliceryhl@google.com>,
	"Trevor Gross" <tmgross@umich.edu>,
	"Danilo Krummrich" <dakr@kernel.org>,
	"FUJITA Tomonori" <fujita.tomonori@gmail.com>,
	"Frederic Weisbecker" <frederic@kernel.org>,
	"Lyude Paul" <lyude@redhat.com>,
	"Thomas Gleixner" <tglx@kernel.org>,
	"Anna-Maria Behnsen" <anna-maria@linutronix.de>,
	"John Stultz" <jstultz@google.com>,
	"Stephen Boyd" <sboyd@kernel.org>,
	"Lorenzo Stoakes" <lorenzo.stoakes@oracle.com>,
	"Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: linux-block@vger.kernel.org, rust-for-linux@vger.kernel.org,
	 linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	 Andreas Hindborg <a.hindborg@kernel.org>
Subject: [PATCH 55/79] block: rust: add request flags abstraction
Date: Mon, 16 Feb 2026 00:35:42 +0100	[thread overview]
Message-ID: <20260216-rnull-v6-19-rc5-send-v1-55-de9a7af4b469@kernel.org> (raw)
In-Reply-To: <20260216-rnull-v6-19-rc5-send-v1-0-de9a7af4b469@kernel.org>

Add the `Flag` enum and `Flags` type as Rust abstractions for the C
`REQ_*` request flags. These flags modify how block I/O requests are
processed, including sync behavior, priority hints, and integrity
settings.

Also add a `flags()` method to `Request` to retrieve the flags for a
given request.

Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
---
 rust/bindings/bindings_helper.h      | 21 ++++++++++++
 rust/kernel/block/mq.rs              |  2 ++
 rust/kernel/block/mq/request.rs      |  9 ++++++
 rust/kernel/block/mq/request/flag.rs | 62 ++++++++++++++++++++++++++++++++++++
 4 files changed, 94 insertions(+)

diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 05133a78ecf95..b8c2f3eadc730 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -134,6 +134,27 @@ const blk_status_t RUST_CONST_HELPER_BLK_STS_OFFLINE = BLK_STS_OFFLINE;
 const blk_status_t RUST_CONST_HELPER_BLK_STS_DURATION_LIMIT = BLK_STS_DURATION_LIMIT;
 const blk_status_t RUST_CONST_HELPER_BLK_STS_INVAL = BLK_STS_INVAL;
 const blk_features_t RUST_CONST_HELPER_BLK_FEAT_ZONED = BLK_FEAT_ZONED;
+const blk_opf_t RUST_CONST_HELPER_REQ_FAILFAST_DEV = REQ_FAILFAST_DEV;
+const blk_opf_t RUST_CONST_HELPER_REQ_FAILFAST_TRANSPORT = REQ_FAILFAST_TRANSPORT;
+const blk_opf_t RUST_CONST_HELPER_REQ_FAILFAST_DRIVER = REQ_FAILFAST_DRIVER;
+const blk_opf_t RUST_CONST_HELPER_REQ_SYNC = REQ_SYNC;
+const blk_opf_t RUST_CONST_HELPER_REQ_META = REQ_META;
+const blk_opf_t RUST_CONST_HELPER_REQ_PRIO = REQ_PRIO;
+const blk_opf_t RUST_CONST_HELPER_REQ_NOMERGE = REQ_NOMERGE;
+const blk_opf_t RUST_CONST_HELPER_REQ_IDLE = REQ_IDLE;
+const blk_opf_t RUST_CONST_HELPER_REQ_INTEGRITY = REQ_INTEGRITY;
+const blk_opf_t RUST_CONST_HELPER_REQ_FUA = REQ_FUA;
+const blk_opf_t RUST_CONST_HELPER_REQ_PREFLUSH = REQ_PREFLUSH;
+const blk_opf_t RUST_CONST_HELPER_REQ_RAHEAD = REQ_RAHEAD;
+const blk_opf_t RUST_CONST_HELPER_REQ_BACKGROUND = REQ_BACKGROUND;
+const blk_opf_t RUST_CONST_HELPER_REQ_NOWAIT = REQ_NOWAIT;
+const blk_opf_t RUST_CONST_HELPER_REQ_POLLED = REQ_POLLED;
+const blk_opf_t RUST_CONST_HELPER_REQ_ALLOC_CACHE = REQ_ALLOC_CACHE;
+const blk_opf_t RUST_CONST_HELPER_REQ_SWAP = REQ_SWAP;
+const blk_opf_t RUST_CONST_HELPER_REQ_DRV = REQ_DRV;
+const blk_opf_t RUST_CONST_HELPER_REQ_FS_PRIVATE = REQ_FS_PRIVATE;
+const blk_opf_t RUST_CONST_HELPER_REQ_ATOMIC = REQ_ATOMIC;
+const blk_opf_t RUST_CONST_HELPER_REQ_NOUNMAP = REQ_NOUNMAP;
 const fop_flags_t RUST_CONST_HELPER_FOP_UNSIGNED_OFFSET = FOP_UNSIGNED_OFFSET;
 
 const xa_mark_t RUST_CONST_HELPER_XA_PRESENT = XA_PRESENT;
diff --git a/rust/kernel/block/mq.rs b/rust/kernel/block/mq.rs
index 1d58eea971bd7..5a1c8e914bb9e 100644
--- a/rust/kernel/block/mq.rs
+++ b/rust/kernel/block/mq.rs
@@ -134,6 +134,8 @@
 pub use operations::IoCompletionBatch;
 pub use operations::Operations;
 pub use request::Command;
+pub use request::Flag as RequestFlag;
+pub use request::Flags as RequestFlags;
 pub use request::IdleRequest;
 pub use request::Request;
 pub use request::RequestTimerHandle;
diff --git a/rust/kernel/block/mq/request.rs b/rust/kernel/block/mq/request.rs
index b4f5a98a97b16..cebb30fe9b3bc 100644
--- a/rust/kernel/block/mq/request.rs
+++ b/rust/kernel/block/mq/request.rs
@@ -27,6 +27,9 @@
 mod command;
 pub use command::Command;
 
+mod flag;
+pub use flag::{Flag, Flags};
+
 /// A [`Request`] that a driver has not yet begun to process.
 ///
 /// A driver can convert an `IdleRequest` to a [`Request`] by calling [`IdleRequest::start`].
@@ -104,6 +107,12 @@ pub fn command(&self) -> Command {
         unsafe { Command::from_raw(self.command_raw()) }
     }
 
+    pub fn flags(&self) -> Flags {
+        // SAFETY: By C API contract and type invariant, `cmd_flags` is valid for read
+        let flags = unsafe { (*self.0.get()).cmd_flags & !((1 << bindings::REQ_OP_BITS) - 1) };
+        Flags::try_from(flags).expect("Request should have valid falgs")
+    }
+
     /// Get the target sector for the request.
     #[inline(always)]
     pub fn sector(&self) -> u64 {
diff --git a/rust/kernel/block/mq/request/flag.rs b/rust/kernel/block/mq/request/flag.rs
new file mode 100644
index 0000000000000..47d25224a1ab4
--- /dev/null
+++ b/rust/kernel/block/mq/request/flag.rs
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+use kernel::prelude::*;
+
+impl_flags! {
+    /// A set of request flags.
+    ///
+    /// This type wraps the C `REQ_*` flags and allows combining multiple flags
+    /// together. These flags modify how a block I/O request is processed.
+    #[derive(Debug, Clone, Default, Copy, PartialEq, Eq)]
+    pub struct Flags(u32);
+
+    /// Individual request flags for block I/O operations.
+    ///
+    /// These flags correspond to the C `REQ_*` defines in `linux/blk_types.h`
+    /// and are used to modify the behavior of block I/O requests.
+    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+    pub enum Flag {
+        /// No driver retries on device errors.
+        FailfastDev = bindings::REQ_FAILFAST_DEV,
+        /// No driver retries on transport errors.
+        FailfastTransport = bindings::REQ_FAILFAST_TRANSPORT,
+        /// No driver retries on driver errors.
+        FailfastDriver = bindings::REQ_FAILFAST_DRIVER,
+        /// Request is synchronous (sync write or read).
+        Sync = bindings::REQ_SYNC,
+        /// Metadata I/O request.
+        Meta = bindings::REQ_META,
+        /// Boost priority in CFQ scheduler.
+        Priority = bindings::REQ_PRIO,
+        /// Don't merge this request with others.
+        NoMerge = bindings::REQ_NOMERGE,
+        /// Anticipate more I/O after this one.
+        Idle = bindings::REQ_IDLE,
+        /// I/O includes block integrity payload.
+        Integrity = bindings::REQ_INTEGRITY,
+        /// Forced unit access - data must be written to persistent storage
+        /// before command completion is signaled.
+        ForcedUnitAccess = bindings::REQ_FUA,
+        /// Request a cache flush before this operation.
+        Preflush = bindings::REQ_PREFLUSH,
+        /// Read ahead request, can fail anytime.
+        ReadAhead = bindings::REQ_RAHEAD,
+        /// Background I/O operation.
+        Background = bindings::REQ_BACKGROUND,
+        /// Don't wait if the request would block.
+        NoWait = bindings::REQ_NOWAIT,
+        /// Caller polls for completion using `bio_poll`.
+        Polled = bindings::REQ_POLLED,
+        /// Allocate I/O from cache if available.
+        AllocCache = bindings::REQ_ALLOC_CACHE,
+        /// Swap I/O operation.
+        Swap = bindings::REQ_SWAP,
+        /// Reserved for driver use.
+        Driver = bindings::REQ_DRV,
+        /// Reserved for file system (submitter) use.
+        FsPrivate = bindings::REQ_FS_PRIVATE,
+        /// Atomic write operation.
+        Atomic = bindings::REQ_ATOMIC,
+        /// Do not free blocks when zeroing (for write zeroes operations).
+        NoUnmap = bindings::REQ_NOUNMAP,
+    }
+}

-- 
2.51.2




  parent reply	other threads:[~2026-02-16  4:13 UTC|newest]

Thread overview: 82+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-02-15 23:34 [PATCH 00/79] block: rnull: complete the rust null block driver Andreas Hindborg
2026-02-15 23:34 ` [PATCH 01/79] block: rnull: adopt new formatting guidelines Andreas Hindborg
2026-02-15 23:34 ` [PATCH 02/79] block: rnull: add module parameters Andreas Hindborg
2026-02-15 23:34 ` [PATCH 03/79] block: rnull: add macros to define configfs attributes Andreas Hindborg
2026-02-15 23:34 ` [PATCH 04/79] block: rust: fix generation of bindings to `BLK_STS_.*` Andreas Hindborg
2026-02-15 23:34 ` [PATCH 05/79] block: rust: change `queue_rq` request type to `Owned` Andreas Hindborg
2026-02-15 23:34 ` [PATCH 06/79] block: rust: add `Request` private data support Andreas Hindborg
2026-02-15 23:34 ` [PATCH 07/79] block: rust: allow `hrtimer::Timer` in `RequestData` Andreas Hindborg
2026-02-15 23:34 ` [PATCH 08/79] block: rnull: add timer completion mode Andreas Hindborg
2026-02-15 23:34 ` [PATCH 09/79] block: rust: introduce `kernel::block::bio` module Andreas Hindborg
2026-02-15 23:34 ` [PATCH 10/79] block: rust: add `command` getter to `Request` Andreas Hindborg
2026-02-15 23:34 ` [PATCH 11/79] block: rust: mq: use GFP_KERNEL from prelude Andreas Hindborg
2026-02-15 23:34 ` [PATCH 12/79] block: rust: add `TagSet` flags Andreas Hindborg
2026-02-15 23:35 ` [PATCH 13/79] block: rnull: add memory backing Andreas Hindborg
2026-02-15 23:35 ` [PATCH 14/79] block: rnull: add submit queue count config option Andreas Hindborg
2026-02-15 23:35 ` [PATCH 15/79] block: rnull: add `use_per_node_hctx` " Andreas Hindborg
2026-02-15 23:35 ` [PATCH 16/79] block: rust: allow specifying home node when constructing `TagSet` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 17/79] block: rnull: allow specifying the home numa node Andreas Hindborg
2026-02-15 23:35 ` [PATCH 18/79] block: rust: add Request::sectors() method Andreas Hindborg
2026-02-15 23:35 ` [PATCH 19/79] block: rust: mq: add max_hw_discard_sectors support to GenDiskBuilder Andreas Hindborg
2026-02-15 23:35 ` [PATCH 20/79] block: rnull: add discard support Andreas Hindborg
2026-02-15 23:35 ` [PATCH 21/79] block: rust: add `NoDefaultScheduler` flag for `TagSet` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 22/79] block: rnull: add no_sched module parameter and configfs attribute Andreas Hindborg
2026-02-15 23:35 ` [PATCH 23/79] block: rust: change sector type from usize to u64 Andreas Hindborg
2026-02-15 23:35 ` [PATCH 24/79] block: rust: add `BadBlocks` for bad block tracking Andreas Hindborg
2026-02-15 23:35 ` [PATCH 25/79] block: rust: mq: add Request::end() method for custom status codes Andreas Hindborg
2026-02-15 23:35 ` [PATCH 26/79] block: rnull: add badblocks support Andreas Hindborg
2026-02-15 23:35 ` [PATCH 27/79] block: rnull: add badblocks_once support Andreas Hindborg
2026-02-15 23:35 ` [PATCH 28/79] block: rnull: add partial I/O support for bad blocks Andreas Hindborg
2026-02-15 23:35 ` [PATCH 29/79] block: rust: add `TagSet` private data support Andreas Hindborg
2026-02-15 23:35 ` [PATCH 30/79] block: rust: add `hctx` " Andreas Hindborg
2026-02-15 23:35 ` [PATCH 31/79] block: rnull: add volatile cache emulation Andreas Hindborg
2026-02-15 23:35 ` [PATCH 32/79] block: rust: implement `Sync` for `GenDisk` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 33/79] block: rust: add a back reference feature to `GenDisk` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 34/79] block: rust: introduce an idle type state for `Request` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 35/79] block: rust: add a request queue abstraction Andreas Hindborg
2026-02-15 23:35 ` [PATCH 36/79] block: rust: add a method to get the request queue for a request Andreas Hindborg
2026-02-15 23:35 ` [PATCH 37/79] block: rust: introduce `kernel::block::error` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 38/79] block: rust: require `queue_rq` to return a `BlkResult` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 39/79] block: rust: add `GenDisk::queue_data` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 40/79] block: rnull: add bandwidth limiting Andreas Hindborg
2026-02-15 23:35 ` [PATCH 41/79] block: rnull: add blocking queue mode Andreas Hindborg
2026-02-15 23:35 ` [PATCH 42/79] block: rnull: add shared tags Andreas Hindborg
2026-02-15 23:35 ` [PATCH 43/79] block: rnull: add queue depth config option Andreas Hindborg
2026-02-15 23:35 ` [PATCH 44/79] block: rust: add an abstraction for `bindings::req_op` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 45/79] block: rust: add a method to set the target sector of a request Andreas Hindborg
2026-02-15 23:35 ` [PATCH 46/79] block: rust: move gendisk vtable construction to separate function Andreas Hindborg
2026-02-15 23:35 ` [PATCH 47/79] block: rust: add zoned block device support Andreas Hindborg
2026-02-15 23:35 ` [PATCH 48/79] block: rnull: add zoned storage support Andreas Hindborg
2026-02-15 23:35 ` [PATCH 49/79] block: rust: add `map_queues` support Andreas Hindborg
2026-02-15 23:35 ` [PATCH 50/79] block: rust: add an abstraction for `struct blk_mq_queue_map` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 51/79] block: rust: add polled completion support Andreas Hindborg
2026-02-15 23:35 ` [PATCH 52/79] block: rust: add accessors to `TagSet` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 53/79] block: rnull: add polled completion support Andreas Hindborg
2026-02-15 23:35 ` [PATCH 54/79] block: rnull: add REQ_OP_FLUSH support Andreas Hindborg
2026-02-15 23:35 ` Andreas Hindborg [this message]
2026-02-15 23:35 ` [PATCH 56/79] block: rust: add abstraction for block queue feature flags Andreas Hindborg
2026-02-15 23:35 ` [PATCH 57/79] block: rust: allow setting write cache and FUA flags for `GenDisk` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 58/79] block: rust: add `Segment::copy_to_page_limit` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 59/79] block: rnull: add fua support Andreas Hindborg
2026-02-15 23:35 ` [PATCH 60/79] block: fix arg type in `blk_mq_update_nr_hw_queues` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 61/79] block: rust: add `GenDisk::tag_set` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 62/79] block: rust: add `TagSet::update_hw_queue_count` Andreas Hindborg
2026-02-16 23:59   ` Ken Kurematsu
2026-02-17  9:54     ` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 63/79] block: rnull: add an option to change the number of hardware queues Andreas Hindborg
2026-02-15 23:35 ` [PATCH 64/79] block: rust: add an abstraction for `struct rq_list` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 65/79] block: rust: add `queue_rqs` vtable hook Andreas Hindborg
2026-02-15 23:35 ` [PATCH 66/79] block: rnull: support queue_rqs Andreas Hindborg
2026-02-15 23:35 ` [PATCH 67/79] block: rust: remove the `is_poll` parameter from `queue_rq` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 68/79] block: rust: add a debug assert for refcounts Andreas Hindborg
2026-02-15 23:35 ` [PATCH 69/79] block: rust: add `TagSet::tag_to_rq` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 70/79] block: rust: add `Request::queue_index` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 71/79] block: rust: add `Request::requeue` Andreas Hindborg
2026-02-15 23:35 ` [PATCH 72/79] block: rust: add `request_timeout` hook Andreas Hindborg
2026-02-15 23:36 ` [PATCH 73/79] block: rnull: add fault injection support Andreas Hindborg
2026-02-15 23:36 ` [PATCH 74/79] block: rust: add max_sectors option to `GenDiskBuilder` Andreas Hindborg
2026-02-15 23:36 ` [PATCH 75/79] block: rnull: allow configuration of the maximum IO size Andreas Hindborg
2026-02-15 23:36 ` [PATCH 76/79] block: rust: add `virt_boundary_mask` option to `GenDiskBuilder` Andreas Hindborg
2026-02-15 23:36 ` [PATCH 77/79] block: rnull: add `virt_boundary` option Andreas Hindborg
2026-02-15 23:36 ` [PATCH 78/79] block: rnull: add `shared_tag_bitmap` config option Andreas Hindborg
2026-02-15 23:36 ` [PATCH 79/79] block: rnull: add zone offline and readonly configfs files Andreas Hindborg

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