* Re: [PATCH] blkcg: update iocost_coef_gen.py to use io_uring
From: Tejun Heo @ 2026-06-24 16:48 UTC (permalink / raw)
To: Jeff Layton; +Cc: Jens Axboe, linux-kernel, linux-block
In-Reply-To: <20260624-iocost-v1-1-2d53f3c026a2@kernel.org>
On Wed, Jun 24, 2026 at 10:50:34AM -0400, Jeff Layton wrote:
> Recently I found myself having to benchmark some rather fast disks for
> iocost, but the old iocost_coef_gen.py script couldn't generate enough
> throughput to saturate it. Make it use io_uring instead.
>
> Cc: Tejun Heo <tj@kernel.org>
> Cc: linux-block@vger.kernel.org
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Thanks.
--
tejun
^ permalink raw reply
* Re: [PATCH 2/2] block: handle REQ_OP_ZONE_APPEND in __bio_integrity_action
From: Caleb Sander Mateos @ 2026-06-24 15:42 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: Jens Axboe, Martin K. Petersen, linux-block
In-Reply-To: <20260624153856.GA13186@lst.de>
On Wed, Jun 24, 2026 at 8:38 AM Christoph Hellwig <hch@lst.de> wrote:
>
> On Wed, Jun 24, 2026 at 08:29:07AM -0700, Caleb Sander Mateos wrote:
> > I take it 4-KB integrity intervals don't work due to the lack of
> > remapping for REQ_OP_ZONE_APPEND? Sounds like we should come back to
> > the discussion about cleaning up the ref tag seed and remapping, then.
> > I never got a reply from Martin on that thread. I guess remapping is
> > necessary at least for partitioned block devices, but we could skip it
> > for non-partitioned block devices if we initialized the ref tag seed
> > correctly.
>
> We don't actually need the partition remapping because there can't
> be partitions. But I see on-the-wire reftag value that are 8 times
> what they should be, so there is some kind of unit mismatch that your
> series fixes.
Right, I don't mean partitions of zoned devices, but block devices in
general. I was just trying to understand why the remapping
infrastructure exists in the first place. Seems like we can't remove
it entirely, but we can at least ensure the ref tag seeds are correct
if it's skipped for a non-partitioned device.
^ permalink raw reply
* Re: [PATCH 2/2] block: handle REQ_OP_ZONE_APPEND in __bio_integrity_action
From: Christoph Hellwig @ 2026-06-24 15:38 UTC (permalink / raw)
To: Caleb Sander Mateos
Cc: Christoph Hellwig, Jens Axboe, Martin K. Petersen, linux-block
In-Reply-To: <CADUfDZo4hysS6qj=Z=dEzVk=DQe6D7-zTFODLk8RGTJ13RY5uQ@mail.gmail.com>
On Wed, Jun 24, 2026 at 08:29:07AM -0700, Caleb Sander Mateos wrote:
> I take it 4-KB integrity intervals don't work due to the lack of
> remapping for REQ_OP_ZONE_APPEND? Sounds like we should come back to
> the discussion about cleaning up the ref tag seed and remapping, then.
> I never got a reply from Martin on that thread. I guess remapping is
> necessary at least for partitioned block devices, but we could skip it
> for non-partitioned block devices if we initialized the ref tag seed
> correctly.
We don't actually need the partition remapping because there can't
be partitions. But I see on-the-wire reftag value that are 8 times
what they should be, so there is some kind of unit mismatch that your
series fixes.
^ permalink raw reply
* Re: [PATCH 2/2] block: handle REQ_OP_ZONE_APPEND in __bio_integrity_action
From: Caleb Sander Mateos @ 2026-06-24 15:29 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: Jens Axboe, Martin K. Petersen, linux-block
In-Reply-To: <20260624080014.1998650-3-hch@lst.de>
On Wed, Jun 24, 2026 at 1:00 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Otherwise zone append commands will miss their integrity data. While
> this works "fine" for auto-PI, it break file system PI and non-PI
> metadata.
>
> With this XFS on ZNS namespace with non-PI metadata and 512 byte sectors
> with PI work, while PI 4k sector formats with PI work only when Caleb's
> "block: fix integrity offset/length conversions" is applied as well.
>
> Note that unlike regular writes, zone append does need remapping as
> partitions are not supported on zoned block devices.
I take it 4-KB integrity intervals don't work due to the lack of
remapping for REQ_OP_ZONE_APPEND? Sounds like we should come back to
the discussion about cleaning up the ref tag seed and remapping, then.
I never got a reply from Martin on that thread. I guess remapping is
necessary at least for partitioned block devices, but we could skip it
for non-partitioned block devices if we initialized the ref tag seed
correctly.
Best,
Caleb
>
> Fixes: df3c485e0e60 ("block: switch on bio operation in bio_integrity_prep")
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> block/bio-integrity.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/block/bio-integrity.c b/block/bio-integrity.c
> index a53b38cf8a1a..b23e2434d80c 100644
> --- a/block/bio-integrity.c
> +++ b/block/bio-integrity.c
> @@ -38,6 +38,7 @@ unsigned int __bio_integrity_action(struct bio *bio)
> }
> return BI_ACT_BUFFER | BI_ACT_CHECK;
> case REQ_OP_WRITE:
> + case REQ_OP_ZONE_APPEND:
> /*
> * Flush masquerading as write?
> */
> --
> 2.53.0
>
^ permalink raw reply
* Re: [PATCH v2] block: serialize elevator changes for the same queue using a writer lock
From: Ming Lei @ 2026-06-24 15:12 UTC (permalink / raw)
To: Shin'ichiro Kawasaki; +Cc: linux-block, Jens Axboe, Nilay Shroff
In-Reply-To: <20260623013238.642052-1-shinichiro.kawasaki@wdc.com>
On Tue, Jun 23, 2026 at 10:32:38AM +0900, Shin'ichiro Kawasaki wrote:
> When elevator_change() is called concurrently for the same queue, the
> elevator_change_done() function runs concurrently as well. This function
> adds or deletes kobjects for the debugfs entry of the queue. Then the
> concurrent calls cause memory corruption of the kobjects and result in a
> process hang. The core part of the elevator switch is protected by queue
> freeze and q->elevator_lock. However, since the commit 559dc11143eb
> ("block: move elv_register[unregister]_queue out of elevator_lock"), the
> elevator_change_done() is not serialized. Hence the memory corruption
> and the hang.
>
> The failures are observed when udev-worker writes to a sysfs
> queue/scheduler attribute file while the blktests test case block/005
> writes to the same attribute file. The failure also can be recreated by
> running two processes that write to the same queue/scheduler file
> concurrently. The failure is observed since another commit 370ac285f23a
> ("block: avoid cpu_hotplug_lock depedency on freeze_lock"). This commit
> changed the behavior of queue freeze and it unveiled the failure.
>
> Fix the failure by changing elv_iosched_store() to acquire
> update_nr_hwq_lock as the writer lock instead of the reader lock. This
> serializes the whole elevator switch steps, including the
> elevator_change_done() call.
>
> Fixes: 559dc11143eb ("block: move elv_register[unregister]_queue out of elevator_lock")
> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> ---
> I observed that the blktests test case block/005 hung on a specific
> server hardware using a specific HDD as a block device. During the test
> case run, the kernel reported KASAN null-ptr-deref and slab-use-after-
> free errors. The failure happened when a sysfs queue/scheduler attribute
> file is written concurrently. I reported the failure and shared a
> candidate fix patch as RFC [1]. Based on the comments and discussion on
> the RFC patch, I propose this v2 patch that avoids introducing a new
> lock. My thanks go to Ming and Nilay for the discussion.
>
> Please refer to [1] for details of the failure. Also, I created a
> blktests test case that recreates the hang [2], which I used to test the
> fix.
>
> * Changes from RFC v1
> - Instead of adding a new mutex to struct request_queue, replace the
> reader lock on update_nr_hwq_lock with the writer lock in
> elv_iosched_store().
>
> [1] https://lore.kernel.org/linux-block/20260611074200.474676-1-shinichiro.kawasaki@wdc.com/
> [2] https://github.com/kawasaki/blktests/commit/8e80b3ccc0bbbe3f209d00eacd138d020de97fc6
>
> block/elevator.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/block/elevator.c b/block/elevator.c
> index 3bcd37c2aa34..b03185a217ff 100644
> --- a/block/elevator.c
> +++ b/block/elevator.c
> @@ -813,7 +813,7 @@ ssize_t elv_iosched_store(struct gendisk *disk, const char *buf,
> * update_nr_hwq_lock -> kn->active (via del_gendisk -> kobject_del)
> * kn->active -> update_nr_hwq_lock (via this sysfs write path)
> */
> - if (!down_read_trylock(&set->update_nr_hwq_lock)) {
> + if (!down_write_trylock(&set->update_nr_hwq_lock)) {
I'd suggest to document why using write_trylock above, such as serializing
2-stage elevator switch, anyway this patch looks good as bug fix:
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Thanks,
Ming
^ permalink raw reply
* Re: [PATCH v2] block: serialize elevator changes for the same queue using a writer lock
From: Ming Lei @ 2026-06-24 15:09 UTC (permalink / raw)
To: Shin'ichiro Kawasaki; +Cc: linux-block, Jens Axboe, Nilay Shroff
In-Reply-To: <ajvCBkxdTCNt9JWI@shinmob>
On Wed, Jun 24, 2026 at 08:48:16PM +0900, Shin'ichiro Kawasaki wrote:
> On Jun 24, 2026 / 04:44, Ming Lei wrote:
> > On Tue, Jun 23, 2026 at 10:32:38AM +0900, Shin'ichiro Kawasaki wrote:
> [...]
> > > Please refer to [1] for details of the failure. Also, I created a
> > > blktests test case that recreates the hang [2], which I used to test the
> > > fix.
> > >
> > > * Changes from RFC v1
> > > - Instead of adding a new mutex to struct request_queue, replace the
> > > reader lock on update_nr_hwq_lock with the writer lock in
> > > elv_iosched_store().
> > >
> > > [1] https://lore.kernel.org/linux-block/20260611074200.474676-1-shinichiro.kawasaki@wdc.com/
> > > [2] https://github.com/kawasaki/blktests/commit/8e80b3ccc0bbbe3f209d00eacd138d020de97fc6
> > >
> > > block/elevator.c | 4 ++--
> > > 1 file changed, 2 insertions(+), 2 deletions(-)
> [...]
> > I feel this is still abuse of the above lock, which serves writer vs
> > reader wrt. updating hw queue.
> >
> > How about the following fix?
>
> (snip)
>
> Thank you for the idea. I applied the suggested fix on top of the v7.1 kernel,
> and ran the test case that does the concurrent write to the sysfs sched file
> [2]. Unfortunately, the test case hung. Before the hang, the kernel reported
> WARNs in sysfs_create_dir_ns() [3]. KASAN slab-use-after-free was observed also.
> I also noticed that another WARN was observed during boot [4].
Looks this change isn't enough, and it is a bit hard to deal with the
two-stage switch by re-lock, and it may require sched debugfs & elevator queue
reg/unreg refactor.
Let's fix with your simpler way first.
Thanks,
Ming
^ permalink raw reply
* [PATCH v6 10/10] rust: module: update MAINTAINERS to cover module.rs
From: Alvin Sun @ 2026-06-24 15:00 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin, Greg Kroah-Hartman,
Rafael J. Wysocki, David Airlie, Simona Vetter, Daniel Almeida,
Arnd Bergmann, Brendan Higgins, David Gow, Rae Moar, Breno Leitao,
Jens Axboe, Dave Ertman, Leon Romanovsky, Igor Korotin,
FUJITA Tomonori, Bjorn Helgaas, Krzysztof Wilczyński,
Arve Hjønnevåg, Todd Kjos, Christian Brauner,
Carlos Llamas
Cc: rust-for-linux, linux-modules, driver-core, dri-devel, nova-gpu,
linux-kselftest, kunit-dev, linux-block, linux-kernel, netdev,
linux-pci, Alvin Sun
In-Reply-To: <20260624-fix-fops-owner-v6-0-5295e333cb3e@linux.dev>
Module types now live in `rust/kernel/module.rs` alongside
`rust/kernel/module_param.rs`. Update the MODULE SUPPORT file pattern
from `rust/kernel/module_param.rs` to `rust/kernel/module*.rs` so both
files are covered.
Assisted-by: opencode:glm-5.2
Link: https://lore.kernel.org/rust-for-linux/8ea21b29-9baf-4926-a16f-7d21c5a1a1b8@suse.com
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
---
MAINTAINERS | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/MAINTAINERS b/MAINTAINERS
index e035a3be797c4..74733de3e41ee 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17984,7 +17984,7 @@ F: include/linux/module*.h
F: kernel/module/
F: lib/test_kmod.c
F: lib/tests/module/
-F: rust/kernel/module_param.rs
+F: rust/kernel/module*.rs
F: rust/macros/module.rs
F: scripts/module*
F: tools/testing/selftests/kmod/
--
2.43.0
^ permalink raw reply related
* [PATCH v6 09/10] rust: macros: remove `THIS_MODULE` static from `module!`
From: Alvin Sun @ 2026-06-24 15:00 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin, Greg Kroah-Hartman,
Rafael J. Wysocki, David Airlie, Simona Vetter, Daniel Almeida,
Arnd Bergmann, Brendan Higgins, David Gow, Rae Moar, Breno Leitao,
Jens Axboe, Dave Ertman, Leon Romanovsky, Igor Korotin,
FUJITA Tomonori, Bjorn Helgaas, Krzysztof Wilczyński,
Arve Hjønnevåg, Todd Kjos, Christian Brauner,
Carlos Llamas
Cc: rust-for-linux, linux-modules, driver-core, dri-devel, nova-gpu,
linux-kselftest, kunit-dev, linux-block, linux-kernel, netdev,
linux-pci, Alvin Sun
In-Reply-To: <20260624-fix-fops-owner-v6-0-5295e333cb3e@linux.dev>
All users have been migrated to `ModuleMetadata::THIS_MODULE` const or
`this_module::<LocalModule>()` helper. The `static THIS_MODULE`
generated by the `module!` macro is no longer referenced anywhere,
so remove it to avoid having two sources of the same `ThisModule`
pointer.
Assisted-by: opencode:glm-5.2
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
---
rust/macros/module.rs | 16 ----------------
1 file changed, 16 deletions(-)
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index aa9a618d5d19e..23b6a1b456b80 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -497,22 +497,6 @@ pub(crate) fn module(info: ModuleInfo) -> Result<TokenStream> {
/// Used by the printing macros, e.g. [`info!`].
const __LOG_PREFIX: &[u8] = #name_cstr.to_bytes_with_nul();
- // SAFETY: `__this_module` is constructed by the kernel at load time and will not be
- // freed until the module is unloaded.
- #[cfg(MODULE)]
- static THIS_MODULE: ::kernel::ThisModule = unsafe {
- extern "C" {
- static __this_module: ::kernel::types::Opaque<::kernel::bindings::module>;
- };
-
- ::kernel::ThisModule::from_ptr(__this_module.get())
- };
-
- #[cfg(not(MODULE))]
- static THIS_MODULE: ::kernel::ThisModule = unsafe {
- ::kernel::ThisModule::from_ptr(::core::ptr::null_mut())
- };
-
/// The `LocalModule` type is the type of the module created by `module!`,
/// `module_pci_driver!`, `module_platform_driver!`, etc.
type LocalModule = #type_;
--
2.43.0
^ permalink raw reply related
* [PATCH v6 06/10] rust: miscdevice: set fops.owner from driver module pointer
From: Alvin Sun @ 2026-06-24 15:00 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin, Greg Kroah-Hartman,
Rafael J. Wysocki, David Airlie, Simona Vetter, Daniel Almeida,
Arnd Bergmann, Brendan Higgins, David Gow, Rae Moar, Breno Leitao,
Jens Axboe, Dave Ertman, Leon Romanovsky, Igor Korotin,
FUJITA Tomonori, Bjorn Helgaas, Krzysztof Wilczyński,
Arve Hjønnevåg, Todd Kjos, Christian Brauner,
Carlos Llamas
Cc: rust-for-linux, linux-modules, driver-core, dri-devel, nova-gpu,
linux-kselftest, kunit-dev, linux-block, linux-kernel, netdev,
linux-pci, Alvin Sun
In-Reply-To: <20260624-fix-fops-owner-v6-0-5295e333cb3e@linux.dev>
Set the miscdevice fops owner field from the driver module pointer
via the `this_module::<T::OwnerModule>()` helper, instead of
defaulting to null.
Assisted-by: opencode:glm-5.2
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
---
rust/kernel/miscdevice.rs | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs
index 83ce50def5ac9..2a4329f98614e 100644
--- a/rust/kernel/miscdevice.rs
+++ b/rust/kernel/miscdevice.rs
@@ -24,12 +24,13 @@
IovIterSource, //
},
mm::virt::VmaNew,
+ module::this_module,
prelude::*,
seq_file::SeqFile,
types::{
ForeignOwnable,
Opaque, //
- },
+ }, //
};
use core::marker::PhantomData;
@@ -430,6 +431,7 @@ impl<T: MiscDevice> MiscdeviceVTable<T> {
} else {
None
},
+ owner: this_module::<T::OwnerModule>().as_ptr(),
..pin_init::zeroed()
};
--
2.43.0
^ permalink raw reply related
* [PATCH v6 08/10] rust: binder: use `LocalModule` for `THIS_MODULE`
From: Alvin Sun @ 2026-06-24 15:00 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin, Greg Kroah-Hartman,
Rafael J. Wysocki, David Airlie, Simona Vetter, Daniel Almeida,
Arnd Bergmann, Brendan Higgins, David Gow, Rae Moar, Breno Leitao,
Jens Axboe, Dave Ertman, Leon Romanovsky, Igor Korotin,
FUJITA Tomonori, Bjorn Helgaas, Krzysztof Wilczyński,
Arve Hjønnevåg, Todd Kjos, Christian Brauner,
Carlos Llamas
Cc: rust-for-linux, linux-modules, driver-core, dri-devel, nova-gpu,
linux-kselftest, kunit-dev, linux-block, linux-kernel, netdev,
linux-pci, Alvin Sun
In-Reply-To: <20260624-fix-fops-owner-v6-0-5295e333cb3e@linux.dev>
Replace the `THIS_MODULE` static reference in the binder fops with
`this_module::<LocalModule>()`, consistent with the move of
`THIS_MODULE` into the `ModuleMetadata` trait.
Assisted-by: opencode:glm-5.2
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
---
drivers/android/binder/rust_binder_main.rs | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/android/binder/rust_binder_main.rs b/drivers/android/binder/rust_binder_main.rs
index dc1941cd2407b..d6ceebbd5f94e 100644
--- a/drivers/android/binder/rust_binder_main.rs
+++ b/drivers/android/binder/rust_binder_main.rs
@@ -17,6 +17,7 @@
bindings::{self, seq_file},
fs::File,
list::{ListArc, ListArcSafe, ListLinksSelfPtr, TryNewListArc},
+ module::this_module,
prelude::*,
seq_file::SeqFile,
seq_print,
@@ -318,7 +319,7 @@ unsafe impl<T> Sync for AssertSync<T> {}
let zeroed_ops = unsafe { core::mem::MaybeUninit::zeroed().assume_init() };
let ops = kernel::bindings::file_operations {
- owner: THIS_MODULE.as_ptr(),
+ owner: this_module::<LocalModule>().as_ptr(),
poll: Some(rust_binder_poll),
unlocked_ioctl: Some(rust_binder_ioctl),
compat_ioctl: bindings::compat_ptr_ioctl,
--
2.43.0
^ permalink raw reply related
* [PATCH v6 07/10] rust: configfs: use `LocalModule` for `THIS_MODULE`
From: Alvin Sun @ 2026-06-24 15:00 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin, Greg Kroah-Hartman,
Rafael J. Wysocki, David Airlie, Simona Vetter, Daniel Almeida,
Arnd Bergmann, Brendan Higgins, David Gow, Rae Moar, Breno Leitao,
Jens Axboe, Dave Ertman, Leon Romanovsky, Igor Korotin,
FUJITA Tomonori, Bjorn Helgaas, Krzysztof Wilczyński,
Arve Hjønnevåg, Todd Kjos, Christian Brauner,
Carlos Llamas
Cc: rust-for-linux, linux-modules, driver-core, dri-devel, nova-gpu,
linux-kselftest, kunit-dev, linux-block, linux-kernel, netdev,
linux-pci, Alvin Sun
In-Reply-To: <20260624-fix-fops-owner-v6-0-5295e333cb3e@linux.dev>
Replace the `THIS_MODULE` static reference in the `configfs_attrs!`
macro with `this_module::<LocalModule>()`, and update
rnull to import `LocalModule` instead of `THIS_MODULE`, consistent
with the move of `THIS_MODULE` into the `ModuleMetadata` trait.
Assisted-by: opencode:glm-5.2
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
---
drivers/block/rnull/configfs.rs | 6 ++----
rust/kernel/configfs.rs | 8 +++++---
2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/block/rnull/configfs.rs b/drivers/block/rnull/configfs.rs
index c10a55fc58948..b2547ad1e5ddd 100644
--- a/drivers/block/rnull/configfs.rs
+++ b/drivers/block/rnull/configfs.rs
@@ -1,9 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
-use super::{
- NullBlkDevice,
- THIS_MODULE, //
-};
+use super::NullBlkDevice;
+use crate::LocalModule;
use kernel::{
block::mq::gen_disk::{
GenDisk,
diff --git a/rust/kernel/configfs.rs b/rust/kernel/configfs.rs
index 2339c6467325d..c31d7882e216d 100644
--- a/rust/kernel/configfs.rs
+++ b/rust/kernel/configfs.rs
@@ -875,7 +875,7 @@ fn as_ptr(&self) -> *const bindings::config_item_type {
/// configfs::Subsystem<Configuration>,
/// Configuration
/// >::new_with_child_ctor::<N,Child>(
-/// &THIS_MODULE,
+/// ::kernel::module::this_module::<crate::LocalModule>(),
/// &CONFIGURATION_ATTRS
/// );
///
@@ -1021,7 +1021,8 @@ macro_rules! configfs_attrs {
static [< $data:upper _TPE >] : $crate::configfs::ItemType<$container, $data> =
$crate::configfs::ItemType::<$container, $data>::new::<N>(
- &THIS_MODULE, &[<$ data:upper _ATTRS >]
+ $crate::module::this_module::<LocalModule>(),
+ &[<$ data:upper _ATTRS >]
);
)?
@@ -1030,7 +1031,8 @@ macro_rules! configfs_attrs {
$crate::configfs::ItemType<$container, $data> =
$crate::configfs::ItemType::<$container, $data>::
new_with_child_ctor::<N, $child>(
- &THIS_MODULE, &[<$ data:upper _ATTRS >]
+ $crate::module::this_module::<LocalModule>(),
+ &[<$ data:upper _ATTRS >]
);
)?
--
2.43.0
^ permalink raw reply related
* [PATCH v6 05/10] rust: drm: set fops.owner from driver module pointer
From: Alvin Sun @ 2026-06-24 15:00 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin, Greg Kroah-Hartman,
Rafael J. Wysocki, David Airlie, Simona Vetter, Daniel Almeida,
Arnd Bergmann, Brendan Higgins, David Gow, Rae Moar, Breno Leitao,
Jens Axboe, Dave Ertman, Leon Romanovsky, Igor Korotin,
FUJITA Tomonori, Bjorn Helgaas, Krzysztof Wilczyński,
Arve Hjønnevåg, Todd Kjos, Christian Brauner,
Carlos Llamas
Cc: rust-for-linux, linux-modules, driver-core, dri-devel, nova-gpu,
linux-kselftest, kunit-dev, linux-block, linux-kernel, netdev,
linux-pci, Alvin Sun
In-Reply-To: <20260624-fix-fops-owner-v6-0-5295e333cb3e@linux.dev>
Change `create_fops()` to accept an owner module pointer instead of
hardcoding `null_mut()`, ensuring the kernel correctly tracks the
module owning the DRM device's file operations.
Assisted-by: opencode:glm-5.2
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
---
rust/kernel/drm/device.rs | 3 ++-
rust/kernel/drm/gem/mod.rs | 4 ++--
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/rust/kernel/drm/device.rs b/rust/kernel/drm/device.rs
index 403fc35353c74..d92cacb665366 100644
--- a/rust/kernel/drm/device.rs
+++ b/rust/kernel/drm/device.rs
@@ -111,7 +111,8 @@ impl<T: drm::Driver> Device<T> {
fops: &Self::GEM_FOPS,
};
- const GEM_FOPS: bindings::file_operations = drm::gem::create_fops();
+ const GEM_FOPS: bindings::file_operations =
+ drm::gem::create_fops(crate::module::this_module::<T::OwnerModule>().as_ptr());
/// Create a new `drm::Device` for a `drm::Driver`.
pub fn new(dev: &device::Device, data: impl PinInit<T::Data, Error>) -> Result<ARef<Self>> {
diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
index 01b5bd47a3332..9a203efc59116 100644
--- a/rust/kernel/drm/gem/mod.rs
+++ b/rust/kernel/drm/gem/mod.rs
@@ -357,10 +357,10 @@ impl<T: DriverObject> AllocImpl for Object<T> {
};
}
-pub(super) const fn create_fops() -> bindings::file_operations {
+pub(super) const fn create_fops(owner: *mut bindings::module) -> bindings::file_operations {
let mut fops: bindings::file_operations = pin_init::zeroed();
- fops.owner = core::ptr::null_mut();
+ fops.owner = owner;
fops.open = Some(bindings::drm_open);
fops.release = Some(bindings::drm_release);
fops.unlocked_ioctl = Some(bindings::drm_ioctl);
--
2.43.0
^ permalink raw reply related
* [PATCH v6 04/10] rust: macros: auto-insert OwnerModule in #[vtable]
From: Alvin Sun @ 2026-06-24 15:00 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin, Greg Kroah-Hartman,
Rafael J. Wysocki, David Airlie, Simona Vetter, Daniel Almeida,
Arnd Bergmann, Brendan Higgins, David Gow, Rae Moar, Breno Leitao,
Jens Axboe, Dave Ertman, Leon Romanovsky, Igor Korotin,
FUJITA Tomonori, Bjorn Helgaas, Krzysztof Wilczyński,
Arve Hjønnevåg, Todd Kjos, Christian Brauner,
Carlos Llamas
Cc: rust-for-linux, linux-modules, driver-core, dri-devel, nova-gpu,
linux-kselftest, kunit-dev, linux-block, linux-kernel, netdev,
linux-pci, Alvin Sun
In-Reply-To: <20260624-fix-fops-owner-v6-0-5295e333cb3e@linux.dev>
Auto-add `type OwnerModule: ::kernel::ModuleMetadata;` as a required
associated type on the trait side if not already defined, and
auto-insert `type OwnerModule = crate::LocalModule;` on the impl side
if not explicitly provided, eliminating the need to manually declare
and implement `OwnerModule` in every vtable trait and impl.
Assisted-by: opencode:glm-5.2
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Suggested-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/all/DIMMWHUOLPSH.13JFRHDKDQJGO@garyguo.net
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
---
rust/macros/lib.rs | 6 ++++++
rust/macros/vtable.rs | 41 ++++++++++++++++++++++++++++++++++++-----
2 files changed, 42 insertions(+), 5 deletions(-)
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index 2cfd59e0f9e7c..bc7ded353c5ca 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -176,6 +176,12 @@ pub fn module(input: TokenStream) -> TokenStream {
///
/// This macro should not be used when all functions are required.
///
+/// Additionally, this macro automatically handles the `OwnerModule`
+/// associated type: on the trait side, `type OwnerModule: ModuleMetadata;`
+/// is added as a required associated type if not already defined; on the
+/// impl side, `type OwnerModule = LocalModule;` is automatically inserted
+/// if not explicitly defined.
+///
/// # Examples
///
/// ```
diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs
index c6510b0c4ea1d..be9a5ed8abe5e 100644
--- a/rust/macros/vtable.rs
+++ b/rust/macros/vtable.rs
@@ -30,6 +30,22 @@ fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
const USE_VTABLE_ATTR: ();
});
+ // Add `type OwnerModule: ModuleMetadata` as a required associated type if
+ // the trait does not already define it.
+ if !item
+ .items
+ .iter()
+ .any(|i| matches!(i, TraitItem::Type(t) if t.ident == "OwnerModule"))
+ {
+ gen_items.push(parse_quote! {
+ /// The module implementing this vtable trait.
+ ///
+ /// Automatically set to `crate::LocalModule` by the `#[vtable]`
+ /// impl macro.
+ type OwnerModule: ::kernel::ModuleMetadata;
+ });
+ }
+
for item in &item.items {
if let TraitItem::Fn(fn_item) = item {
let name = &fn_item.sig.ident;
@@ -57,12 +73,18 @@ fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
fn handle_impl(mut item: ItemImpl) -> Result<ItemImpl> {
let mut gen_items = Vec::new();
- let mut defined_consts = HashSet::new();
+ let mut defined_items = HashSet::new();
- // Iterate over all user-defined constants to gather any possible explicit overrides.
+ // Iterate over all user-defined items to gather any possible explicit overrides.
for item in &item.items {
- if let ImplItem::Const(const_item) = item {
- defined_consts.insert(const_item.ident.clone());
+ match item {
+ ImplItem::Const(const_item) => {
+ defined_items.insert(const_item.ident.clone());
+ }
+ ImplItem::Type(type_item) => {
+ defined_items.insert(type_item.ident.clone());
+ }
+ _ => {}
}
}
@@ -70,6 +92,15 @@ fn handle_impl(mut item: ItemImpl) -> Result<ItemImpl> {
const USE_VTABLE_ATTR: () = ();
});
+ // Auto-insert `type OwnerModule = crate::LocalModule` if not explicitly defined.
+ // `crate::LocalModule` resolves to the real module type (via `module!`) or a
+ // dummy fallback in non-module contexts (e.g., doctests).
+ if !defined_items.contains(&parse_quote!(OwnerModule)) {
+ gen_items.push(parse_quote! {
+ type OwnerModule = crate::LocalModule;
+ });
+ }
+
for item in &item.items {
if let ImplItem::Fn(fn_item) = item {
let name = &fn_item.sig.ident;
@@ -78,7 +109,7 @@ fn handle_impl(mut item: ItemImpl) -> Result<ItemImpl> {
name.span(),
);
// Skip if it's declared already -- this allows user override.
- if defined_consts.contains(&gen_const_name) {
+ if defined_items.contains(&gen_const_name) {
continue;
}
let cfg_attrs = crate::helpers::gather_cfg_attrs(&fn_item.attrs);
--
2.43.0
^ permalink raw reply related
* [PATCH v6 03/10] rust: doctest: add LocalModule fallback for #[vtable] ThisModule
From: Alvin Sun @ 2026-06-24 15:00 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin, Greg Kroah-Hartman,
Rafael J. Wysocki, David Airlie, Simona Vetter, Daniel Almeida,
Arnd Bergmann, Brendan Higgins, David Gow, Rae Moar, Breno Leitao,
Jens Axboe, Dave Ertman, Leon Romanovsky, Igor Korotin,
FUJITA Tomonori, Bjorn Helgaas, Krzysztof Wilczyński,
Arve Hjønnevåg, Todd Kjos, Christian Brauner,
Carlos Llamas
Cc: rust-for-linux, linux-modules, driver-core, dri-devel, nova-gpu,
linux-kselftest, kunit-dev, linux-block, linux-kernel, netdev,
linux-pci, Alvin Sun
In-Reply-To: <20260624-fix-fops-owner-v6-0-5295e333cb3e@linux.dev>
Add a `LocalModule` struct with a null-pointer `ModuleMetadata` impl
in the doctest harness, so that `crate::LocalModule` (auto-inserted
by `#[vtable]`) resolves correctly when there is no `module!` macro.
Assisted-by: opencode:glm-5.2
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
---
scripts/rustdoc_test_gen.rs | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/scripts/rustdoc_test_gen.rs b/scripts/rustdoc_test_gen.rs
index ee76e96b41eea..198af4e446c8c 100644
--- a/scripts/rustdoc_test_gen.rs
+++ b/scripts/rustdoc_test_gen.rs
@@ -239,6 +239,22 @@ macro_rules! assert_eq {{
const __LOG_PREFIX: &[u8] = b"rust_doctests_kernel\0";
+/// Dummy module type for doctest context.
+struct LocalModule;
+
+use kernel::{{
+ str::CStr,
+ ModuleMetadata,
+ ThisModule, //
+}};
+use core::ptr::null_mut;
+
+impl ModuleMetadata for LocalModule {{
+ const NAME: &'static CStr = c"rust_doctests_kernel";
+ // SAFETY: `try_module_get`/`module_put` handle null module pointers gracefully.
+ const THIS_MODULE: ThisModule = unsafe {{ ThisModule::from_ptr(null_mut()) }};
+}}
+
{rust_tests}
"#
)
--
2.43.0
^ permalink raw reply related
* [PATCH v6 02/10] rust: module: add `THIS_MODULE` const to `ModuleMetadata` trait
From: Alvin Sun @ 2026-06-24 15:00 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin, Greg Kroah-Hartman,
Rafael J. Wysocki, David Airlie, Simona Vetter, Daniel Almeida,
Arnd Bergmann, Brendan Higgins, David Gow, Rae Moar, Breno Leitao,
Jens Axboe, Dave Ertman, Leon Romanovsky, Igor Korotin,
FUJITA Tomonori, Bjorn Helgaas, Krzysztof Wilczyński,
Arve Hjønnevåg, Todd Kjos, Christian Brauner,
Carlos Llamas
Cc: rust-for-linux, linux-modules, driver-core, dri-devel, nova-gpu,
linux-kselftest, kunit-dev, linux-block, linux-kernel, netdev,
linux-pci, Alvin Sun
In-Reply-To: <20260624-fix-fops-owner-v6-0-5295e333cb3e@linux.dev>
Since `const_refs_to_static` has been stable as of the MSRV bump, a
`ThisModule` pointer can now be used in const contexts.
Add a `THIS_MODULE` const to the `ModuleMetadata` trait so that modules
can provide their `ThisModule` pointer in const contexts such as static
`file_operations`.
Add a `this_module()` helper to retrieve the `THIS_MODULE` pointer of a
given module type, and update `__init` to use it instead of the
`THIS_MODULE` static generated by the `module!` macro.
The `static THIS_MODULE` generated by the `module!` macro is retained
for backwards compatibility with existing users and removed in a later
patch once all references have been migrated.
Assisted-by: opencode:glm-5.2
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
---
rust/kernel/module.rs | 9 +++++++++
rust/macros/module.rs | 18 +++++++++++++++++-
2 files changed, 26 insertions(+), 1 deletion(-)
diff --git a/rust/kernel/module.rs b/rust/kernel/module.rs
index be242a82e86d2..d713705984477 100644
--- a/rust/kernel/module.rs
+++ b/rust/kernel/module.rs
@@ -42,6 +42,15 @@ fn init(module: &'static ThisModule) -> impl pin_init::PinInit<Self, crate::erro
pub trait ModuleMetadata {
/// The name of the module as specified in the `module!` macro.
const NAME: &'static crate::str::CStr;
+
+ /// The module's `THIS_MODULE` pointer.
+ const THIS_MODULE: ThisModule;
+}
+
+/// Returns a reference to the `THIS_MODULE` of the given module type.
+#[inline]
+pub const fn this_module<M: ModuleMetadata>() -> &'static ThisModule {
+ &M::THIS_MODULE
}
/// Equivalent to `THIS_MODULE` in the C API.
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index 06c18e2075083..aa9a618d5d19e 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -519,6 +519,22 @@ pub(crate) fn module(info: ModuleInfo) -> Result<TokenStream> {
impl ::kernel::ModuleMetadata for #type_ {
const NAME: &'static ::kernel::str::CStr = #name_cstr;
+
+ #[cfg(MODULE)]
+ const THIS_MODULE: ::kernel::ThisModule = {
+ extern "C" {
+ static __this_module: ::kernel::types::Opaque<::kernel::bindings::module>;
+ }
+
+ // SAFETY: `__this_module` is constructed by the kernel at load time
+ // and lives until the module is unloaded.
+ unsafe { ::kernel::ThisModule::from_ptr(__this_module.get()) }
+ };
+
+ #[cfg(not(MODULE))]
+ const THIS_MODULE: ::kernel::ThisModule = unsafe {
+ ::kernel::ThisModule::from_ptr(::core::ptr::null_mut())
+ };
}
// Double nested modules, since then nobody can access the public items inside.
@@ -616,7 +632,7 @@ pub extern "C" fn #ident_exit() {
/// This function must only be called once.
unsafe fn __init() -> ::kernel::ffi::c_int {
let initer = <super::super::LocalModule as ::kernel::InPlaceModule>::init(
- &super::super::THIS_MODULE
+ ::kernel::module::this_module::<super::super::LocalModule>()
);
// SAFETY: No data race, since `__MOD` can only be accessed by this module
// and there only `__init` and `__exit` access it. These functions are only
--
2.43.0
^ permalink raw reply related
* [PATCH v6 00/10] Fix missing fops.owner in Rust DRM/misc abstractions
From: Alvin Sun @ 2026-06-24 14:59 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin, Greg Kroah-Hartman,
Rafael J. Wysocki, David Airlie, Simona Vetter, Daniel Almeida,
Arnd Bergmann, Brendan Higgins, David Gow, Rae Moar, Breno Leitao,
Jens Axboe, Dave Ertman, Leon Romanovsky, Igor Korotin,
FUJITA Tomonori, Bjorn Helgaas, Krzysztof Wilczyński,
Arve Hjønnevåg, Todd Kjos, Christian Brauner,
Carlos Llamas
Cc: rust-for-linux, linux-modules, driver-core, dri-devel, nova-gpu,
linux-kselftest, kunit-dev, linux-block, linux-kernel, netdev,
linux-pci, Alvin Sun
During tyr debugfs development, a kernel NULL pointer dereference was
encountered after `rmmod tyr` while gnome-shell still held /dev/card1 open:
```
[158827.868132] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[158827.868918] Mem abort info:
[158827.869177] ESR = 0x0000000086000004
[158827.869519] EC = 0x21: IABT (current EL), IL = 32 bits
[158827.870000] SET = 0, FnV = 0
[158827.870281] EA = 0, S1PTW = 0
[158827.870571] FSC = 0x04: level 0 translation fault
[158827.871043] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000108dec000
[158827.871623] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
[158827.872242] Internal error: Oops: 0000000086000004 [#1] SMP
[158827.872246] Modules linked in: tyr sunrpc snd_soc_simple_card rk805_pwrkey snd_soc_simple_card_utils rtw88_8822bu display_connector rtw88_usb rtw88_8822b snd_soc_rockchip_i2s_tdm snd_soc_hdmi_codec
rtw88_core]
[158827.872337] CPU: 4 UID: 1000 PID: 11276 Comm: gnome-s:disk$0 Tainted: G N 7.1.0-rc1+ #331 PREEMPT
[158827.880534] Tainted: [N]=TEST
[158827.880535] Hardware name: FriendlyElec NanoPi R6C/NanoPi R6C, BIOS v1.1 04/09/2025
[158827.880538] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[158827.880542] pc : 0x0
[158827.880547] lr : _RNvNtCs257m05FHVbX_3tyr2vm8pt_unmap+0x8c/0x12c [tyr]
[158827.880578] sp : ffff800083c236b0
[158827.880579] x29: ffff800083c236d0 x28: ffff00013f8a0000 x27: 0000000000000000
[158827.880585] x26: 000000000000007c x25: ffff000108e6ed80 x24: 0000000000401000
[158827.880590] x23: 0000000000000000 x22: 0000000040000000 x21: 0000000000001000
[158827.880595] x20: ffff00010f778138 x19: 0000000000400000 x18: 00000000ffffffff
[158827.880600] x17: 000000040044ffff x16: 045000f2b5503510 x15: 0720072007200720
[158827.880606] x14: 0720072007200720 x13: 0000000000401000 x12: 0000000000400000
[158827.880611] x11: ffff800083c239d0 x10: ffff000141e4fd88 x9 : 0000000000000000
[158827.880615] x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000400000
[158827.880620] x5 : ffff00013f8a0000 x4 : 0000000000000000 x3 : 0000000000000001
[158827.880625] x2 : 0000000000001000 x1 : 0000000000400000 x0 : ffff00010f778138
[158827.880630] Call trace:
[158827.880632] 0x0 (P)
[158827.880635] _RNvXs6_NtCs257m05FHVbX_3tyr2vmNtB5_9GpuVmDataNtNtNtCsgmSOfgXi5CZ_6kernel3drm5gpuvm11DriverGpuVm13sm_step_unmap+0x3c/0x120 [tyr]
[158827.891166] _RNvMs4_NtNtNtCsgmSOfgXi5CZ_6kernel3drm5gpuvm6sm_opsINtB7_5GpuVmNtNtCs257m05FHVbX_3tyr2vm9GpuVmDataE13sm_step_unmapB13_+0x18/0x34 [tyr]
[158827.891187] op_unmap_cb+0x78/0xb0
[158827.891196] __drm_gpuvm_sm_unmap+0x18c/0x1b4
[158827.891204] drm_gpuvm_sm_unmap+0x38/0x4c
[158827.891209] _RNvMs5_NtCs257m05FHVbX_3tyr2vmNtB5_2Vm7exec_op+0x1cc/0x254 [tyr]
[158827.894085] _RNvMs5_NtCs257m05FHVbX_3tyr2vmNtB5_2Vm11unmap_range+0x124/0x188 [tyr]
[158827.894105] _RINvNtCs5hGKnPbRUFW_4core3ptr13drop_in_placeNtNtCs257m05FHVbX_3tyr3gem8KernelBoEBK_+0x44/0xd8 [tyr]
[158827.894125] _RINvNtCs5hGKnPbRUFW_4core3ptr13drop_in_placeINtNtNtCsgmSOfgXi5CZ_6kernel5alloc4kvec3VecNtNtCs257m05FHVbX_3tyr2fw7SectionNtNtBL_9allocator7KmallocEEB1r_+0x3c/0x100 [tyr]
[158827.894147] _RINvNtCs5hGKnPbRUFW_4core3ptr13drop_in_placeINtNtNtCsgmSOfgXi5CZ_6kernel4sync3arc3ArcNtNtCs257m05FHVbX_3tyr2fw8FirmwareEEB1p_+0x94/0x190 [tyr]
[158827.894167] _RNvMs4_NtNtCsgmSOfgXi5CZ_6kernel3drm6deviceINtB5_6DeviceNtNtCs257m05FHVbX_3tyr6driver12TyrDrmDriverE7releaseBW_+0x30/0x98 [tyr]
[158827.899550] drm_dev_put.part.0+0x88/0xc0
[158827.899557] drm_minor_release+0x18/0x28
[158827.899562] drm_release+0x144/0x170
[158827.899567] __fput+0xe4/0x30c
[158827.899573] ____fput+0x14/0x20
[158827.899579] task_work_run+0x7c/0xe8
[158827.899586] do_exit+0x2a8/0xac4
[158827.899590] do_group_exit+0x34/0x90
[158827.899594] get_signal+0xaac/0xabc
[158827.899599] arch_do_signal_or_restart+0x90/0x3e8
[158827.899606] exit_to_user_mode_loop+0x140/0x1d0
[158827.899613] el0_svc+0x2f4/0x2f8
[158827.899620] el0t_64_sync_handler+0xa0/0xe4
[158827.899627] el0t_64_sync+0x198/0x19c
[158827.899632] ---[ end trace 0000000000000000 ]---
```
The root cause: `fops.owner` was `NULL` in Rust DRM drivers, so the kernel
never blocked module unloading while file descriptors were open. This leads to
use-after-free when drm_release (or other fops) is called on freed module code.
The series moves `THIS_MODULE` into the `ModuleMetadata` as a const, threads it
through `#[vtable]` to set `fops.owner` in DRM/miscdevice, and updates configfs
and rnull to use `this_module::<LocalModule>()`.
Assisted-by: opencode:glm-5.2
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
---
Changes in v6:
- Update MAINTAINERS to cover the new `rust/kernel/module.rs`.
- Link to v5: https://lore.kernel.org/r/20260624-fix-fops-owner-v5-0-aa1cba242f05@linux.dev
Changes in v5:
- Add `#[inline]` to the `this_module()` helper.
- Fix configfs doc comment to reference `crate::LocalModule` instead of
bare `LocalModule`.
- Link to v4: https://lore.kernel.org/r/20260623-fix-fops-owner-v4-0-0daf5f077d5c@linux.dev
Changes in v4:
- Move module-related types into a new `rust/kernel/module.rs`.
- Migrate binder from the `module!`-generated `THIS_MODULE` static to
`this_module::<LocalModule>()`.
- Reorganise the series so that every commit builds independently, and
drop the legacy `THIS_MODULE` static once all users are migrated.
- Link to v3: https://lore.kernel.org/r/20260622-fix-fops-owner-v3-0-49d45cb37032@linux.dev
Changes in v3:
- Renamed vtable associated type `ThisModule` to `OwnerModule`
- Added `this_module()` helper for ergonomic `THIS_MODULE` access
- Refined vtable macro implementation: one-liner detection and single `defined_items` set
- Reordered commits to place doctest fallback before vtable auto-insert
- Link to v2: https://lore.kernel.org/r/20260521-fix-fops-owner-v2-0-fd99079c5a04@linux.dev
Changes in v2:
- Merged old `static THIS_MODULE` and v1's `MODULE_PTR` into a single
`ModuleMetadata::THIS_MODULE` const
- `#[vtable]` macro now auto-inserts `type ThisModule`, removing all per-driver
manual patches from v1
- Added configfs & rnull usage site updates and doctest `LocalModule` fallback
- Link to v1: https://lore.kernel.org/r/20260519-fix-fops-owner-v1-0-2ded9830da14@linux.dev
---
Alvin Sun (10):
rust: module: move module types into `module.rs`
rust: module: add `THIS_MODULE` const to `ModuleMetadata` trait
rust: doctest: add LocalModule fallback for #[vtable] ThisModule
rust: macros: auto-insert OwnerModule in #[vtable]
rust: drm: set fops.owner from driver module pointer
rust: miscdevice: set fops.owner from driver module pointer
rust: configfs: use `LocalModule` for `THIS_MODULE`
rust: binder: use `LocalModule` for `THIS_MODULE`
rust: macros: remove `THIS_MODULE` static from `module!`
rust: module: update MAINTAINERS to cover module.rs
MAINTAINERS | 2 +-
drivers/android/binder/rust_binder_main.rs | 3 +-
drivers/block/rnull/configfs.rs | 6 +--
rust/kernel/auxiliary.rs | 2 +-
rust/kernel/configfs.rs | 8 +--
rust/kernel/drm/device.rs | 3 +-
rust/kernel/drm/gem/mod.rs | 4 +-
rust/kernel/i2c.rs | 2 +-
rust/kernel/lib.rs | 75 +++-------------------------
rust/kernel/miscdevice.rs | 4 +-
rust/kernel/module.rs | 80 ++++++++++++++++++++++++++++++
rust/kernel/net/phy.rs | 6 ++-
rust/kernel/pci.rs | 2 +-
rust/kernel/platform.rs | 2 +-
rust/kernel/usb.rs | 2 +-
rust/macros/lib.rs | 6 +++
rust/macros/module.rs | 34 ++++++-------
rust/macros/vtable.rs | 41 +++++++++++++--
scripts/rustdoc_test_gen.rs | 16 ++++++
19 files changed, 189 insertions(+), 109 deletions(-)
---
base-commit: b7e5ac83cb16f7ffd11dc23736f84276602100ed
change-id: 20260519-fix-fops-owner-e3a77bb27c6c
prerequisite-change-id: 20260519-miscdev-use-format-9ab7e83b1c11:v3
prerequisite-patch-id: 405b334ff0d48ad350014f05a2321bdbaa025400
prerequisite-patch-id: 604b631c81d5423f4ebb2e12ba2d22e9ce371bfc
prerequisite-patch-id: cb550d94cefe01920e0d3ced2b2bcbecd76f3907
prerequisite-patch-id: 3bc830839742591460cb86d9472c04f4686dc600
prerequisite-patch-id: 571058244bc8c7088638d2e3225713011246c7e9
prerequisite-patch-id: 347c5a3c6dbef9832bfce8419fc23e6e08ba477f
prerequisite-patch-id: 3e202d988b56b88446f7535e90d3f00cf5f15701
Best regards,
--
Alvin Sun <alvin.sun@linux.dev>
^ permalink raw reply
* [PATCH v6 01/10] rust: module: move module types into `module.rs`
From: Alvin Sun @ 2026-06-24 15:00 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin, Greg Kroah-Hartman,
Rafael J. Wysocki, David Airlie, Simona Vetter, Daniel Almeida,
Arnd Bergmann, Brendan Higgins, David Gow, Rae Moar, Breno Leitao,
Jens Axboe, Dave Ertman, Leon Romanovsky, Igor Korotin,
FUJITA Tomonori, Bjorn Helgaas, Krzysztof Wilczyński,
Arve Hjønnevåg, Todd Kjos, Christian Brauner,
Carlos Llamas
Cc: rust-for-linux, linux-modules, driver-core, dri-devel, nova-gpu,
linux-kselftest, kunit-dev, linux-block, linux-kernel, netdev,
linux-pci, Alvin Sun
In-Reply-To: <20260624-fix-fops-owner-v6-0-5295e333cb3e@linux.dev>
Move `Module`, `InPlaceModule`, `ModuleMetadata` and `ThisModule` from
`lib.rs` into a new `rust/kernel/module.rs`. Re-export them from `lib.rs`
to avoid tree-wide changes.
Switch six bus driver registrations from `module.0` to the public
`ThisModule::as_ptr()` accessor, since the field is no longer visible
outside the new `module` submodule.
No functional change.
Assisted-by: opencode:glm-5.2
Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
---
rust/kernel/auxiliary.rs | 2 +-
rust/kernel/i2c.rs | 2 +-
rust/kernel/lib.rs | 75 +++++-------------------------------------------
rust/kernel/module.rs | 71 +++++++++++++++++++++++++++++++++++++++++++++
rust/kernel/net/phy.rs | 6 +++-
rust/kernel/pci.rs | 2 +-
rust/kernel/platform.rs | 2 +-
rust/kernel/usb.rs | 2 +-
8 files changed, 88 insertions(+), 74 deletions(-)
diff --git a/rust/kernel/auxiliary.rs b/rust/kernel/auxiliary.rs
index 93c0db1f66555..4a02f83240be3 100644
--- a/rust/kernel/auxiliary.rs
+++ b/rust/kernel/auxiliary.rs
@@ -63,7 +63,7 @@ unsafe fn register(
// SAFETY: `adrv` is guaranteed to be a valid `DriverType`.
to_result(unsafe {
- bindings::__auxiliary_driver_register(adrv.get(), module.0, name.as_char_ptr())
+ bindings::__auxiliary_driver_register(adrv.get(), module.as_ptr(), name.as_char_ptr())
})
}
diff --git a/rust/kernel/i2c.rs b/rust/kernel/i2c.rs
index 7b908f0c5a58d..24eff08f47123 100644
--- a/rust/kernel/i2c.rs
+++ b/rust/kernel/i2c.rs
@@ -142,7 +142,7 @@ unsafe fn register(
}
// SAFETY: `idrv` is guaranteed to be a valid `DriverType`.
- to_result(unsafe { bindings::i2c_register_driver(module.0, idrv.get()) })
+ to_result(unsafe { bindings::i2c_register_driver(module.as_ptr(), idrv.get()) })
}
unsafe fn unregister(idrv: &Opaque<Self::DriverType>) {
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index b72b2fbe046d6..040ae85056509 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -93,6 +93,7 @@
pub mod maple_tree;
pub mod miscdevice;
pub mod mm;
+pub mod module;
pub mod module_param;
#[cfg(CONFIG_NET)]
pub mod net;
@@ -139,79 +140,17 @@
#[doc(hidden)]
pub use bindings;
pub use macros;
+pub use module::{
+ InPlaceModule,
+ Module,
+ ModuleMetadata,
+ ThisModule, //
+};
pub use uapi;
/// Prefix to appear before log messages printed from within the `kernel` crate.
const __LOG_PREFIX: &[u8] = b"rust_kernel\0";
-/// The top level entrypoint to implementing a kernel module.
-///
-/// For any teardown or cleanup operations, your type may implement [`Drop`].
-pub trait Module: Sized + Sync + Send {
- /// Called at module initialization time.
- ///
- /// Use this method to perform whatever setup or registration your module
- /// should do.
- ///
- /// Equivalent to the `module_init` macro in the C API.
- fn init(module: &'static ThisModule) -> error::Result<Self>;
-}
-
-/// A module that is pinned and initialised in-place.
-pub trait InPlaceModule: Sync + Send {
- /// Creates an initialiser for the module.
- ///
- /// It is called when the module is loaded.
- fn init(module: &'static ThisModule) -> impl pin_init::PinInit<Self, error::Error>;
-}
-
-impl<T: Module> InPlaceModule for T {
- fn init(module: &'static ThisModule) -> impl pin_init::PinInit<Self, error::Error> {
- let initer = move |slot: *mut Self| {
- let m = <Self as Module>::init(module)?;
-
- // SAFETY: `slot` is valid for write per the contract with `pin_init_from_closure`.
- unsafe { slot.write(m) };
- Ok(())
- };
-
- // SAFETY: On success, `initer` always fully initialises an instance of `Self`.
- unsafe { pin_init::pin_init_from_closure(initer) }
- }
-}
-
-/// Metadata attached to a [`Module`] or [`InPlaceModule`].
-pub trait ModuleMetadata {
- /// The name of the module as specified in the `module!` macro.
- const NAME: &'static crate::str::CStr;
-}
-
-/// Equivalent to `THIS_MODULE` in the C API.
-///
-/// C header: [`include/linux/init.h`](srctree/include/linux/init.h)
-pub struct ThisModule(*mut bindings::module);
-
-// SAFETY: `THIS_MODULE` may be used from all threads within a module.
-unsafe impl Sync for ThisModule {}
-
-impl ThisModule {
- /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer.
- ///
- /// # Safety
- ///
- /// The pointer must be equal to the right `THIS_MODULE`.
- pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule {
- ThisModule(ptr)
- }
-
- /// Access the raw pointer for this module.
- ///
- /// It is up to the user to use it correctly.
- pub const fn as_ptr(&self) -> *mut bindings::module {
- self.0
- }
-}
-
#[cfg(not(testlib))]
#[panic_handler]
fn panic(info: &core::panic::PanicInfo<'_>) -> ! {
diff --git a/rust/kernel/module.rs b/rust/kernel/module.rs
new file mode 100644
index 0000000000000..be242a82e86d2
--- /dev/null
+++ b/rust/kernel/module.rs
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Module-related types and helpers.
+
+/// The entrypoint to implementing a kernel module.
+///
+/// For any teardown or cleanup operations, your type may implement [`Drop`].
+pub trait Module: Sized + Sync + Send {
+ /// Called at module initialization time.
+ ///
+ /// Use this method to perform whatever setup or registration your module
+ /// should do.
+ ///
+ /// Equivalent to the `module_init` macro in the C API.
+ fn init(module: &'static ThisModule) -> crate::error::Result<Self>;
+}
+
+/// A module that is pinned and initialised in-place.
+pub trait InPlaceModule: Sync + Send {
+ /// Creates an initialiser for the module.
+ ///
+ /// It is called when the module is loaded.
+ fn init(module: &'static ThisModule) -> impl pin_init::PinInit<Self, crate::error::Error>;
+}
+
+impl<T: Module> InPlaceModule for T {
+ fn init(module: &'static ThisModule) -> impl pin_init::PinInit<Self, crate::error::Error> {
+ let initer = move |slot: *mut Self| {
+ let m = <Self as Module>::init(module)?;
+
+ // SAFETY: `slot` is valid for write per the contract with `pin_init_from_closure`.
+ unsafe { slot.write(m) };
+ Ok(())
+ };
+
+ // SAFETY: On success, `initer` always fully initialises an instance of `Self`.
+ unsafe { pin_init::pin_init_from_closure(initer) }
+ }
+}
+
+/// Metadata attached to a [`Module`] or [`InPlaceModule`].
+pub trait ModuleMetadata {
+ /// The name of the module as specified in the `module!` macro.
+ const NAME: &'static crate::str::CStr;
+}
+
+/// Equivalent to `THIS_MODULE` in the C API.
+///
+/// C header: [`include/linux/init.h`](srctree/include/linux/init.h)
+pub struct ThisModule(*mut crate::bindings::module);
+
+// SAFETY: `THIS_MODULE` may be used from all threads within a module.
+unsafe impl Sync for ThisModule {}
+
+impl ThisModule {
+ /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer.
+ ///
+ /// # Safety
+ ///
+ /// The pointer must be equal to the right `THIS_MODULE`.
+ pub const unsafe fn from_ptr(ptr: *mut crate::bindings::module) -> ThisModule {
+ ThisModule(ptr)
+ }
+
+ /// Access the raw pointer for this module.
+ ///
+ /// It is up to the user to use it correctly.
+ pub const fn as_ptr(&self) -> *mut crate::bindings::module {
+ self.0
+ }
+}
diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs
index 3ca99db5cccf2..8b7036b8fe480 100644
--- a/rust/kernel/net/phy.rs
+++ b/rust/kernel/net/phy.rs
@@ -659,7 +659,11 @@ pub fn register(
// the `drivers` slice are initialized properly. `drivers` will not be moved.
// So it's just an FFI call.
to_result(unsafe {
- bindings::phy_drivers_register(drivers[0].0.get(), drivers.len().try_into()?, module.0)
+ bindings::phy_drivers_register(
+ drivers[0].0.get(),
+ drivers.len().try_into()?,
+ module.as_ptr(),
+ )
})?;
// INVARIANT: The `drivers` slice is successfully registered to the kernel via `phy_drivers_register`.
Ok(Registration { drivers })
diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index af74ddff6114d..916ed2cb6b70b 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -86,7 +86,7 @@ unsafe fn register(
// SAFETY: `pdrv` is guaranteed to be a valid `DriverType`.
to_result(unsafe {
- bindings::__pci_register_driver(pdrv.get(), module.0, name.as_char_ptr())
+ bindings::__pci_register_driver(pdrv.get(), module.as_ptr(), name.as_char_ptr())
})
}
diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index 8917d4ee499fb..9fdbafd53bc21 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -82,7 +82,7 @@ unsafe fn register(
}
// SAFETY: `pdrv` is guaranteed to be a valid `DriverType`.
- to_result(unsafe { bindings::__platform_driver_register(pdrv.get(), module.0) })
+ to_result(unsafe { bindings::__platform_driver_register(pdrv.get(), module.as_ptr()) })
}
unsafe fn unregister(pdrv: &Opaque<Self::DriverType>) {
diff --git a/rust/kernel/usb.rs b/rust/kernel/usb.rs
index 9c17a672cd275..213db32727c17 100644
--- a/rust/kernel/usb.rs
+++ b/rust/kernel/usb.rs
@@ -63,7 +63,7 @@ unsafe fn register(
// SAFETY: `udrv` is guaranteed to be a valid `DriverType`.
to_result(unsafe {
- bindings::usb_register_driver(udrv.get(), module.0, name.as_char_ptr())
+ bindings::usb_register_driver(udrv.get(), module.as_ptr(), name.as_char_ptr())
})
}
--
2.43.0
^ permalink raw reply related
* [PATCH] blkcg: update iocost_coef_gen.py to use io_uring
From: Jeff Layton @ 2026-06-24 14:50 UTC (permalink / raw)
To: Jens Axboe; +Cc: linux-kernel, Tejun Heo, linux-block, Jeff Layton
Recently I found myself having to benchmark some rather fast disks for
iocost, but the old iocost_coef_gen.py script couldn't generate enough
throughput to saturate it. Make it use io_uring instead.
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-block@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
tools/cgroup/iocost_coef_gen.py | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/cgroup/iocost_coef_gen.py b/tools/cgroup/iocost_coef_gen.py
index df17a2ae80e5..41f93f4536cc 100644
--- a/tools/cgroup/iocost_coef_gen.py
+++ b/tools/cgroup/iocost_coef_gen.py
@@ -91,7 +91,7 @@ def run_fio(testfile, duration, iotype, iodepth, blocksize, jobs):
eta = 'never' if args.quiet else 'always'
outfile = tempfile.NamedTemporaryFile()
- cmd = (f'fio --direct=1 --ioengine=libaio --name=coef '
+ cmd = (f'fio --direct=1 --ioengine=io_uring --name=coef '
f'--filename={testfile} --runtime={round(duration)} '
f'--readwrite={iotype} --iodepth={iodepth} --blocksize={blocksize} '
f'--eta={eta} --output-format json --output={outfile.name} '
---
base-commit: 840ef6c78e6a2f694b578ecb9063241c992aaa9e
change-id: 20260624-iocost-a196820cc049
Best regards,
--
Jeff Layton <jlayton@kernel.org>
^ permalink raw reply related
* Re: [PATCH v3 1/7] list: Add mutable iterator variants
From: David Laight @ 2026-06-24 14:23 UTC (permalink / raw)
To: Christian König
Cc: Kaitao Cheng, Andrew Morton, David Hildenbrand, Jens Axboe,
Tejun Heo, Alexander Viro, Christian Brauner, Alexei Starovoitov,
Daniel Borkmann, Andrii Nakryiko, Johannes Weiner, Peter Zijlstra,
Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim,
Thomas Gleixner, Juri Lelli, Vincent Guittot, Paul Moore,
Andy Shevchenko, Paul E. McKenney, Shakeel Butt, David Howells,
Simona Vetter, Randy Dunlap, Luca Ceresoli, Philipp Stanner,
linux-block, linux-kernel, cgroups, linux-ntfs-dev, linux-fsdevel,
io-uring, audit, bpf, netdev, dri-devel, linux-perf-users,
linux-trace-kernel, kexec, live-patching, linux-modules,
linux-crypto, linux-pm, rcu, sched-ext, linux-mm, virtualization,
damon, llvm, Kaitao Cheng
In-Reply-To: <cf8467c7-b98f-44a5-9cf9-60b43b5da711@amd.com>
On Wed, 24 Jun 2026 15:23:47 +0200
Christian König <christian.koenig@amd.com> wrote:
> On 6/24/26 15:14, Kaitao Cheng wrote:
> >
> >
> > 在 2026/6/22 16:42, David Laight 写道:
> >> On Mon, 22 Jun 2026 12:05:31 +0800
> >> Kaitao Cheng <kaitao.cheng@linux.dev> wrote:
> >>
> >>> From: Kaitao Cheng <chengkaitao@kylinos.cn>
> >>>
> >>> The list_for_each*_safe() helpers are used when the loop body may
> >>> remove the current entry. Their API exposes the temporary cursor at
> >>> every call site, even though most users only need it for the iterator
> >>> implementation and never reference it in the loop body.
> >>>
> >>> Add *_mutable() variants for list and hlist iteration. The new helpers
> >>> support both forms: callers may keep passing an explicit temporary cursor
> >>> when they need to inspect or reset it, or omit it and let the helper use
> >>> a unique internal cursor.
> >>
> >> I'm not really sure 'mutable' means anything either.
> >> It is possible to make it valid for the loop body (or even other threads)
> >> to delete arbitrary list items - but that needs significant extra overheads.
> >>
> >> It might be worth doing something that doesn't need the extra variable,
> >> but there is little point doing all the churn just to rename things.
> >>
> >>>
> >>> This makes call sites that only mutate the list through the current entry
> >>> less noisy, while keeping the existing *_safe() helpers available for
> >>> compatibility.
> >>>
> >>> Signed-off-by: Kaitao Cheng <chengkaitao@kylinos.cn>
> >>> ---
> >>> include/linux/list.h | 269 +++++++++++++++++++++++++++++++++++++------
> >>> 1 file changed, 231 insertions(+), 38 deletions(-)
> >>>
> >>> diff --git a/include/linux/list.h b/include/linux/list.h
> >>> index 09d979976b3b..1081def7cea9 100644
> >>> --- a/include/linux/list.h
> >>> +++ b/include/linux/list.h
> >>> @@ -7,6 +7,7 @@
> >>> #include <linux/stddef.h>
> >>> #include <linux/poison.h>
> >>> #include <linux/const.h>
> >>> +#include <linux/args.h>
> >>>
> >>> #include <asm/barrier.h>
> >>>
> >>> @@ -763,28 +764,72 @@ static inline void list_splice_tail_init(struct list_head *list,
> >>> #define list_for_each_prev(pos, head) \
> >>> for (pos = (head)->prev; !list_is_head(pos, (head)); pos = pos->prev)
> >>>
> >>> -/**
> >>> - * list_for_each_safe - iterate over a list safe against removal of list entry
> >>> - * @pos: the &struct list_head to use as a loop cursor.
> >>> - * @n: another &struct list_head to use as temporary storage
> >>> - * @head: the head for your list.
> >>> +/*
> >>> + * list_for_each_safe is an old interface, use list_for_each_mutable instead.
> >>> */
> >>> #define list_for_each_safe(pos, n, head) \
> >>> for (pos = (head)->next, n = pos->next; \
> >>> !list_is_head(pos, (head)); \
> >>> pos = n, n = pos->next)
> >>>
> >>> +#define __list_for_each_mutable_internal(pos, tmp, head) \
> >>> + for (typeof(pos) tmp = (pos = (head)->next)->next; \
> >>
> >> Use auto
> >>
> >>> + !list_is_head(pos, (head)); \
> >>> + pos = tmp, tmp = pos->next)
> >>> +
> >>> +#define __list_for_each_mutable1(pos, head) \
> >>> + __list_for_each_mutable_internal(pos, __UNIQUE_ID(next), head)
> >>> +
> >>> +#define __list_for_each_mutable2(pos, next, head) \
> >>> + list_for_each_safe(pos, next, head)
> >>> +
> >>> /**
> >>> - * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
> >>> + * list_for_each_mutable - iterate over a list safe against entry removal
> >>> * @pos: the &struct list_head to use as a loop cursor.
> >>> - * @n: another &struct list_head to use as temporary storage
> >>> - * @head: the head for your list.
> >>> + * @...: either (head) or (next, head)
> >>> + *
> >>> + * next: another &struct list_head to use as optional temporary storage.
> >>> + * The temporary cursor is internal unless explicitly supplied by
> >>> + * the caller.
> >>> + * head: the head for your list.
> >>> + */
> >>> +#define list_for_each_mutable(pos, ...) \
> >>> + CONCATENATE(__list_for_each_mutable, COUNT_ARGS(__VA_ARGS__)) \
> >>> + (pos, __VA_ARGS__)
> >>
> >> The variable argument count logic really just slows down compilation.
> >> Maybe there aren't enough copies of this code to make that significant.
> >> But just because you can do it doesn't mean it is a gooD idea.
> >> I'm also not sure it really adds anything to the readability.
> >>
> >> And, it you are going to make the middle argument optional there is
> >> no need to change the macro name.
> >
> > Christian König and Jani Nikula also disagree with the variadic-argument
> > implementation approach. If we abandon that method, it means we will
> > inevitably need to add some new macros. If mutable is not a good name,
> > suggestions for better alternatives would be welcome; coming up with a
> > suitable name is indeed rather tricky.
>
> I don't think you need to add a new macro for the specific use case that people want to modify the next element of the iteration.
>
> If I remember your numbers correctly that is a really corner case and keeping using the existing *_safe() macros for that sounds perfectly fine to me.
IIRC currently you have a choice of either:
define Item that can't be deleted
list_for_each() The current item.
list_for_each_safe() The next item.
There is also likely to be code that updates the variables to allow
for other scenarios.
Note that if increase a reference count and release a lock then list_for_each()
is likely safer than list_for_each_safe() :-)
list.h has 9 variants of the 'safe' loop.
The bloat of another 9 is getting excessive.
It has to be said that this is one of my least favourite type of list...
David
>
> Regards,
> Christian.
^ permalink raw reply
* Re: [PATCH] null_blk: cancel bw_timer on add-device error unwind
From: Nilay Shroff @ 2026-06-24 14:21 UTC (permalink / raw)
To: Cen Zhang, Jens Axboe, Keith Busch, Johannes Thumshirn,
Chaitanya Kulkarni, Damien Le Moal, Genjian Zhang, Hans Holmberg,
Kees Cook, Matthew Wilcox, Christophe JAILLET, Kyungchan Koh,
Shaohua Li
Cc: linux-block, linux-kernel, baijiaju1990
In-Reply-To: <20260624071825.357098-1-zzzccc427@gmail.com>
On 6/24/26 12:48 PM, Cen Zhang wrote:
> null_blk starts the bandwidth hrtimer before the later add_disk/device_add
> failure points. If setup fails after the timer is queued, the shared error
> unwind frees struct nullb without draining bw_timer, so the callback can
> run on freed owner state.
>
> The buggy scenario involves two paths, with each column showing the order
> within that path:
>
> null_add_dev() error unwind: nullb_bwtimer_fn() callback path:
> 1. Start bw_timer for a throttled 1. The hrtimer expires after the free.
> device. 2. nullb_bwtimer_fn() recovers the
> 2. Hit a later add_disk/device_add embedded owner.
> failure. 3. The callback reads nullb->dev and
> 3. Free struct nullb. nullb->q.
> 4. Release the remaining queue and 4. The stale owner storage is used
> disk resources. after free.
>
> Cancel bw_timer in the shared error unwind before put_disk() and the
> remaining frees. The normal delete path already uses the same
> hrtimer_cancel() drain.
Looks good to me.
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
^ permalink raw reply
* Re: [PATCH RFC v2 17/18] fs: look up the superblock via the device table in user_get_super()
From: Christoph Hellwig @ 2026-06-24 14:07 UTC (permalink / raw)
To: Christian Brauner
Cc: Jan Kara, Christoph Hellwig, Jens Axboe, Alexander Viro,
linux-block, linux-kernel, linux-fsdevel, Carlos Maiolino,
linux-xfs, Chris Mason, David Sterba, linux-btrfs,
Theodore Ts'o, linux-ext4, Gao Xiang, linux-erofs
In-Reply-To: <20260616-work-super-bdev_holder_global-v2-17-7df6b864028e@kernel.org>
On Tue, Jun 16, 2026 at 04:08:33PM +0200, Christian Brauner wrote:
> user_get_super() still finds the superblock for a device number by
> walking the global super_blocks list under sb_lock. Every superblock is
> registered in the device table under its s_dev since sget_fc() inserts
> it there, including superblocks on anonymous devices, so use the table
> instead.
So what is the benefit of this? It's not like any of these are heavily
used fast paths.
^ permalink raw reply
* Re: [PATCH RFC v2 08/18] fs: add dedicated block device open helpers for filesystems
From: Christoph Hellwig @ 2026-06-24 14:06 UTC (permalink / raw)
To: Jan Kara
Cc: Christian Brauner, Christoph Hellwig, Jens Axboe, Alexander Viro,
linux-block, linux-kernel, linux-fsdevel, Carlos Maiolino,
linux-xfs, Chris Mason, David Sterba, linux-btrfs,
Theodore Ts'o, linux-ext4, Gao Xiang, linux-erofs
In-Reply-To: <xlfnmwv2upjia6ozd4z5l5icaewor4a6cgkafnigulndzmt6r7@rhay3h3wablo>
On Mon, Jun 22, 2026 at 06:28:50PM +0200, Jan Kara wrote:
> > +static int fs_bdev_register(struct file *bdev_file, struct super_block *sb)
> > +{
> > + struct super_dev *sb_dev __free(kfree) = NULL;
>
> Frankly I find the use of __free on sb_dev more confusing than helping in
> this function. If you didn't use it, you could remove the somewhat
> confusing retain_and_null_ptr() calls below, remove this initialization and
> just put one kfree() into the error handling branch when super_dev_insert()
> fails...
It is. __free is really annoying for anything but trivial local
scope only variables.
^ permalink raw reply
* Re: [PATCH RFC v2 07/18] fs: maintain a global device-to-superblock table
From: Christoph Hellwig @ 2026-06-24 14:05 UTC (permalink / raw)
To: Christian Brauner
Cc: Jan Kara, Christoph Hellwig, Jens Axboe, Alexander Viro,
linux-block, linux-kernel, linux-fsdevel, Carlos Maiolino,
linux-xfs, Chris Mason, David Sterba, linux-btrfs,
Theodore Ts'o, linux-ext4, Gao Xiang, linux-erofs
In-Reply-To: <20260616-work-super-bdev_holder_global-v2-7-7df6b864028e@kernel.org>
FYI, I still think maintaining a dev_t to sb mapping vs having a holder
register a claim is a major step backwards architecturally. I spent
a lot of effort to get us out of this.
^ permalink raw reply
* Re: [PATCH RFC v2 01/18] xfs: fix the error unwind in xfs_open_devices()
From: Christoph Hellwig @ 2026-06-24 14:05 UTC (permalink / raw)
To: Christian Brauner
Cc: Jan Kara, Christoph Hellwig, Jens Axboe, Alexander Viro,
linux-block, linux-kernel, linux-fsdevel, Carlos Maiolino,
linux-xfs, Chris Mason, David Sterba, linux-btrfs,
Theodore Ts'o, linux-ext4, Gao Xiang, linux-erofs
In-Reply-To: <20260616-work-super-bdev_holder_global-v2-1-7df6b864028e@kernel.org>
On Tue, Jun 16, 2026 at 04:08:17PM +0200, Christian Brauner wrote:
> Since the rt and log block devices are closed in xfs_free_buftarg() the
> buftarg owns the device file. The error unwind does not respect that:
> when the log buftarg allocation fails, out_free_rtdev_targ frees the rt
> buftarg - releasing rtdev_file - and then falls through to
> out_close_rtdev and releases it a second time.
>
> The unwind also leaves mp->m_rtdev_targp and mp->m_ddev_targp pointing
> to the freed buftargs. The failed mount continues into
> deactivate_locked_super() -> xfs_kill_sb() -> xfs_mount_free(), which
> frees them again.
>
> Clear the buftarg pointers once the unwind freed them and clear
> rtdev_file once the rt buftarg owns it, so nothing is released twice.
>
> Reachable when a buftarg allocation fails after the data buftarg was
> set up: an I/O error in sync_blockdev() or an allocation failure in
> xfs_init_buftarg() while mounting with external rt and log devices.
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
I actually have a major rework of this area pending, but it probably
won't land for 7.2, so we might as well get this local fix in ASAP.
^ permalink raw reply
* Re: [PATCH v5 0/9] Fix missing fops.owner in Rust DRM/misc abstractions
From: Miguel Ojeda @ 2026-06-24 14:02 UTC (permalink / raw)
To: Petr Pavlu
Cc: Alvin Sun, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
Trevor Gross, Danilo Krummrich, Luis Chamberlain, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin, Greg Kroah-Hartman,
Rafael J. Wysocki, David Airlie, Simona Vetter, Daniel Almeida,
Arnd Bergmann, Brendan Higgins, David Gow, Rae Moar, Breno Leitao,
Jens Axboe, Dave Ertman, Leon Romanovsky, Igor Korotin,
FUJITA Tomonori, Bjorn Helgaas, Krzysztof Wilczyński,
Arve Hjønnevåg, Todd Kjos, Christian Brauner,
Carlos Llamas, rust-for-linux, linux-modules, driver-core,
dri-devel, nova-gpu, linux-kselftest, kunit-dev, linux-block,
linux-kernel, netdev, linux-pci
In-Reply-To: <8ea21b29-9baf-4926-a16f-7d21c5a1a1b8@suse.com>
On Wed, Jun 24, 2026 at 3:23 PM Petr Pavlu <petr.pavlu@suse.com> wrote:
>
> I would only suggest adding the new file rust/kernel/module.rs in
> patch #1 under the MODULE SUPPORT support entry in the MAINTAINERS file,
> similarly to the other module-related Rust code, so that the module
> maintainers are emailed when changes to this file are proposed. I think
> you can change the existing 'F: rust/kernel/module_param.rs' to
> 'F: rust/kernel/module*.rs'.
That would be great, yes -- thanks!
Cheers,
Miguel
^ permalink raw reply
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