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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 37/79] block: rust: introduce `kernel::block::error`
Date: Mon, 16 Feb 2026 00:35:24 +0100	[thread overview]
Message-ID: <20260216-rnull-v6-19-rc5-send-v1-37-de9a7af4b469@kernel.org> (raw)
In-Reply-To: <20260216-rnull-v6-19-rc5-send-v1-0-de9a7af4b469@kernel.org>

Block layer status codes, represented by `blk_status_t`, are only one
byte. This is different from the general kernel error codes.

Add `BlkError` and `BlkResult` to handle these status codes.

Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
---
 rust/kernel/block.rs | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 rust/kernel/error.rs |  3 +-
 2 files changed, 96 insertions(+), 1 deletion(-)

diff --git a/rust/kernel/block.rs b/rust/kernel/block.rs
index 19236ab95227b..6cd83dc75a5eb 100644
--- a/rust/kernel/block.rs
+++ b/rust/kernel/block.rs
@@ -18,3 +18,97 @@
 /// The difference between the size of a page and the size of a sector,
 /// expressed as a power of two.
 pub const PAGE_SECTORS_SHIFT: u32 = bindings::PAGE_SECTORS_SHIFT;
+
+pub mod error {
+    //! Block layer errors.
+
+    use core::num::NonZeroU8;
+
+    pub mod code {
+        //! C compatible error codes for the block subsystem.
+        macro_rules! declare_err {
+            ($err:tt $(,)? $($doc:expr),+) => {
+                $(
+                    #[doc = $doc]
+                )*
+                    pub const $err: super::BlkError =
+                    match super::BlkError::try_from_blk_status(crate::bindings::$err as u8) {
+                        Some(err) => err,
+                        None => panic!("Invalid errno in `declare_err!`"),
+                    };
+            };
+        }
+
+        declare_err!(BLK_STS_NOTSUPP, "Operation not supported.");
+        declare_err!(BLK_STS_IOERR, "Generic IO error.");
+        declare_err!(BLK_STS_DEV_RESOURCE, "Device resource busy. Retry later.");
+    }
+
+    /// A wrapper around a 1 byte block layer error code.
+    #[derive(Clone, Copy, PartialEq, Eq)]
+    pub struct BlkError(NonZeroU8);
+
+    impl BlkError {
+        /// Create a [`BlkError`] from a `blk_status_t`.
+        ///
+        /// If the code is not know, this function will warn and return [`code::BLK_STS_IOERR`].
+        pub fn from_blk_status(status: bindings::blk_status_t) -> Self {
+            if let Some(error) = Self::try_from_blk_status(status) {
+                error
+            } else {
+                kernel::pr_warn!("Attempted to create `BlkError` from invalid value");
+                code::BLK_STS_IOERR
+            }
+        }
+
+        /// Convert `Self` to the underlying type.
+        pub fn to_blk_status(self) -> bindings::blk_status_t {
+            self.0.into()
+        }
+
+        /// Try to create a `Self` form a `blk_status_t`.
+        ///
+        /// Returns `None` if the conversion fails.
+        const fn try_from_blk_status(errno: bindings::blk_status_t) -> Option<Self> {
+            if errno == 0 {
+                None
+            } else {
+                Some(BlkError(
+                    // SAFETY: We just checked that `errno`is nonzero.
+                    unsafe { NonZeroU8::new_unchecked(errno) },
+                ))
+            }
+        }
+    }
+
+    impl From<BlkError> for u8 {
+        fn from(value: BlkError) -> Self {
+            value.0.into()
+        }
+    }
+
+    impl From<BlkError> for u32 {
+        fn from(value: BlkError) -> Self {
+            let value: u8 = value.0.into();
+            value.into()
+        }
+    }
+
+    impl From<kernel::error::Error> for BlkError {
+        fn from(_value: kernel::error::Error) -> Self {
+            code::BLK_STS_IOERR
+        }
+    }
+
+    /// A result with a [`BlkError`] error type.
+    pub type BlkResult<T = ()> = Result<T, BlkError>;
+
+    /// Convert a `blk_status_t` to a `BlkResult`.
+    pub fn to_result(status: bindings::blk_status_t) -> BlkResult {
+        if status == bindings::BLK_STS_OK {
+            Ok(())
+        } else {
+            Err(BlkError::from_blk_status(status))
+        }
+    }
+}
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 258b12afdcba3..e656465010d6c 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -162,8 +162,9 @@ pub fn to_errno(self) -> crate::ffi::c_int {
         self.0.get()
     }
 
+    /// Convert a generic kernel error to a block layer error.
     #[cfg(CONFIG_BLOCK)]
-    pub(crate) fn to_blk_status(self) -> bindings::blk_status_t {
+    pub fn to_blk_status(self) -> bindings::blk_status_t {
         // SAFETY: `self.0` is a valid error due to its invariant.
         unsafe { bindings::errno_to_blk_status(self.0.get()) }
     }

-- 
2.51.2




  parent reply	other threads:[~2026-02-16  1:03 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 ` Andreas Hindborg [this message]
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 ` [PATCH 55/79] block: rust: add request flags abstraction Andreas Hindborg
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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