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 59/79] block: rnull: add fua support
Date: Mon, 16 Feb 2026 00:35:46 +0100 [thread overview]
Message-ID: <20260216-rnull-v6-19-rc5-send-v1-59-de9a7af4b469@kernel.org> (raw)
In-Reply-To: <20260216-rnull-v6-19-rc5-send-v1-0-de9a7af4b469@kernel.org>
Add Forced Unit Access (FUA) support to rnull. When enabled via the `fua`
configfs attribute, the driver advertises FUA capability and handles FUA
requests by bypassing the volatile cache in the write path.
FUA support requires memory backing and write cache to be enabled.
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
---
drivers/block/rnull/configfs.rs | 5 ++++
drivers/block/rnull/disk_storage.rs | 22 +++++++++++++---
drivers/block/rnull/disk_storage/page.rs | 1 +
drivers/block/rnull/rnull.rs | 45 ++++++++++++++++++++++++--------
4 files changed, 58 insertions(+), 15 deletions(-)
diff --git a/drivers/block/rnull/configfs.rs b/drivers/block/rnull/configfs.rs
index e134e21a6b564..816c057f130fc 100644
--- a/drivers/block/rnull/configfs.rs
+++ b/drivers/block/rnull/configfs.rs
@@ -118,6 +118,7 @@ fn make_group(
zone_max_active: 25,
zone_append_max_sectors: 26,
poll_queues: 27,
+ fua: 28,
],
};
@@ -158,6 +159,7 @@ fn make_group(
zone_max_active: 0,
zone_append_max_sectors: u32::MAX,
poll_queues: 0,
+ fua: true,
}),
}),
core::iter::empty(),
@@ -234,6 +236,7 @@ struct DeviceConfigInner {
zone_max_active: u32,
zone_append_max_sectors: u32,
poll_queues: u32,
+ fua: bool,
}
#[vtable]
@@ -285,6 +288,7 @@ fn store(this: &DeviceConfig, page: &[u8]) -> Result {
zone_max_active: guard.zone_max_active,
zone_append_max_sectors: guard.zone_append_max_sectors,
poll_queues: guard.poll_queues,
+ forced_unit_access: guard.fua,
})?);
guard.powered = true;
} else if guard.powered && !power_op {
@@ -527,3 +531,4 @@ fn store(this: &DeviceConfig, page: &[u8]) -> Result {
}
}
);
+configfs_simple_bool_field!(DeviceConfig, 28, fua);
diff --git a/drivers/block/rnull/disk_storage.rs b/drivers/block/rnull/disk_storage.rs
index a613ed5223ba7..b2b5eaa783cdc 100644
--- a/drivers/block/rnull/disk_storage.rs
+++ b/drivers/block/rnull/disk_storage.rs
@@ -92,6 +92,10 @@ pub(crate) fn flush(&self, hw_data: &Pin<&SpinLock<HwQueueContext>>) -> Result {
let mut access = self.access(&mut tree_guard, &mut hw_data_guard, None);
access.flush()
}
+
+ pub(crate) fn cache_enabled(&self) -> bool {
+ self.cache_size > 0
+ }
}
pub(crate) struct DiskStorageAccess<'a, 'b, 'c> {
@@ -190,7 +194,7 @@ fn flush(&mut self) -> Result {
Ok(())
}
- fn get_cache_page(&mut self, sector: u64) -> Result<&mut NullBlockPage> {
+ fn get_or_alloc_cache_page(&mut self, sector: u64) -> Result<&mut NullBlockPage> {
let index = Self::to_index(sector);
if self.cache_guard.contains_index(index) {
@@ -215,6 +219,12 @@ fn get_cache_page(&mut self, sector: u64) -> Result<&mut NullBlockPage> {
}
}
+ pub(crate) fn get_cache_page(&mut self, sector: u64) -> Option<&mut NullBlockPage> {
+ let index = Self::to_index(sector);
+
+ self.cache_guard.get_mut(index)
+ }
+
fn get_disk_page(&mut self, sector: u64) -> Result<&mut NullBlockPage> {
let index = Self::to_index(sector);
@@ -232,9 +242,13 @@ fn get_disk_page(&mut self, sector: u64) -> Result<&mut NullBlockPage> {
Ok(page)
}
- pub(crate) fn get_write_page(&mut self, sector: u64) -> Result<&mut NullBlockPage> {
- let page = if self.disk_storage.cache_size > 0 {
- self.get_cache_page(sector)?
+ pub(crate) fn get_write_page(
+ &mut self,
+ sector: u64,
+ bypass_cache: bool,
+ ) -> Result<&mut NullBlockPage> {
+ let page = if self.disk_storage.cache_size > 0 && !bypass_cache {
+ self.get_or_alloc_cache_page(sector)?
} else {
self.get_disk_page(sector)?
};
diff --git a/drivers/block/rnull/disk_storage/page.rs b/drivers/block/rnull/disk_storage/page.rs
index a34fe0762724d..728073d5dd23d 100644
--- a/drivers/block/rnull/disk_storage/page.rs
+++ b/drivers/block/rnull/disk_storage/page.rs
@@ -14,6 +14,7 @@
uapi::PAGE_SECTORS, //
};
+// TODO: Use rust bitmap
const _CHEKC_STATUS_WIDTH: () = build_assert!((PAGE_SIZE >> SECTOR_SHIFT) <= 64);
pub(crate) struct NullBlockPage {
diff --git a/drivers/block/rnull/rnull.rs b/drivers/block/rnull/rnull.rs
index 4870aa3b7a53e..3b7edfe7efe44 100644
--- a/drivers/block/rnull/rnull.rs
+++ b/drivers/block/rnull/rnull.rs
@@ -193,6 +193,10 @@
default: 0,
description: "Number of IOPOLL submission queues.",
},
+ fua: u8 {
+ default: 1,
+ description: "Enable/disable FUA support when cache_size is used. Default: 1 (true)",
+ },
},
}
@@ -250,6 +254,7 @@ fn init(_module: &'static ThisModule) -> impl PinInit<Self, Error> {
zone_max_active: *module_parameters::zone_max_active.value(),
zone_append_max_sectors: *module_parameters::zone_append_max_sectors.value(),
poll_queues: *module_parameters::poll_queues.value(),
+ forced_unit_access: *module_parameters::fua.value() != 0,
})?;
disks.push(disk, GFP_KERNEL)?;
}
@@ -298,6 +303,7 @@ struct NullBlkOptions<'a> {
#[cfg_attr(not(CONFIG_BLK_DEV_ZONED), expect(unused_variables))]
zone_append_max_sectors: u32,
poll_queues: u32,
+ forced_unit_access: bool,
}
static SHARED_TAG_SET: SetOnce<Arc<TagSet<NullBlkDevice>>> = SetOnce::new();
@@ -356,13 +362,11 @@ fn new(options: NullBlkOptions<'_>) -> Result<Arc<GenDisk<Self>>> {
zone_max_active,
zone_append_max_sectors,
poll_queues,
+ forced_unit_access,
} = options;
let mut flags = mq::tag_set::Flags::default();
- // TODO: lim.features |= BLK_FEAT_WRITE_CACHE;
- // if (dev->fua)
- // lim.features |= BLK_FEAT_FUA;
if blocking || memory_backed {
flags |= mq::tag_set::Flag::Blocking;
}
@@ -404,9 +408,10 @@ fn new(options: NullBlkOptions<'_>) -> Result<Arc<GenDisk<Self>>> {
let device_capacity_sectors = mib_to_sectors(device_capacity_mib);
+ let s = storage.clone();
let queue_data = Arc::try_pin_init(
try_pin_init!(Self {
- storage,
+ storage: s,
irq_mode,
completion_time,
memory_backed,
@@ -439,7 +444,9 @@ fn new(options: NullBlkOptions<'_>) -> Result<Arc<GenDisk<Self>>> {
.capacity_sectors(device_capacity_sectors)
.logical_block_size(block_size_bytes)?
.physical_block_size(block_size_bytes)?
- .rotational(rotational);
+ .rotational(rotational)
+ .write_cache(storage.cache_enabled())
+ .forced_unit_access(forced_unit_access && storage.cache_enabled());
#[cfg(CONFIG_BLK_DEV_ZONED)]
{
@@ -496,6 +503,7 @@ fn write<'a, 'b, 'c>(
hw_data_guard: &'b mut SpinLockGuard<'c, HwQueueContext>,
mut sector: u64,
mut segment: Segment<'_>,
+ bypass_cache: bool,
) -> Result {
let mut sheaf: Option<XArraySheaf<'_>> = None;
@@ -524,12 +532,21 @@ fn write<'a, 'b, 'c>(
let mut access = self.storage.access(tree_guard, hw_data_guard, sheaf);
- let page = access.get_write_page(sector)?;
+ if bypass_cache {
+ if let Some(page) = access.get_cache_page(sector) {
+ page.set_free(sector);
+ }
+ }
+
+ let page = access.get_write_page(sector, bypass_cache)?;
page.set_occupied(sector);
let page_offset = (sector & u64::from(block::SECTOR_MASK)) << block::SECTOR_SHIFT;
- sector += segment.copy_to_page(page.page_mut().get_pin_mut(), page_offset as usize)
- as u64
+ sector += segment.copy_to_page_limit(
+ page.page_mut().get_pin_mut(),
+ page_offset as usize,
+ self.block_size_bytes.try_into()?,
+ ) as u64
>> block::SECTOR_SHIFT;
sheaf = access.sheaf;
@@ -588,6 +605,8 @@ fn transfer(
let mut hw_data_guard = hw_data.lock();
let mut tree_guard = self.storage.lock();
+ let skip_cache = rq.flags().contains(mq::RequestFlag::ForcedUnitAccess);
+
for bio in rq.bio_iter_mut() {
let segment_iter = bio.segment_iter();
for segment in segment_iter {
@@ -596,9 +615,13 @@ fn transfer(
.len()
.min((end_sector - sector) as u32 >> SECTOR_SHIFT);
match command {
- mq::Command::Write => {
- self.write(&mut tree_guard, &mut hw_data_guard, sector, segment)?
- }
+ mq::Command::Write => self.write(
+ &mut tree_guard,
+ &mut hw_data_guard,
+ sector,
+ segment,
+ skip_cache,
+ )?,
mq::Command::Read => {
self.read(&mut tree_guard, &mut hw_data_guard, sector, segment)?
}
--
2.51.2
next prev parent reply other threads:[~2026-02-16 4:17 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 ` [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 ` Andreas Hindborg [this message]
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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