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Author SHA1 Message Date
Shankari Anand
9caa30dada drivers: android: binder: Update ARef imports from sync::aref
Update call sites in binder files to import `ARef`
from `sync::aref` instead of `types`.

This aligns with the ongoing effort to move `ARef` and
`AlwaysRefCounted` to sync.

Suggested-by: Benno Lossin <lossin@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Signed-off-by: Shankari Anand <shankari.ak0208@gmail.com>
Acked-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260102202714.184223-2-shankari.ak0208@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-03 12:58:36 +01:00
Shivam Kalra
38ac9179a7 rust_binder: fix needless borrow in context.rs
Clippy warns about a needless borrow in context.rs:

    error: this expression creates a reference which is immediately dereferenced by the compiler
       --> drivers/android/binder/context.rs:141:18
        |
    141 |             func(&proc);
        |                  ^^^^^ help: change this to: `proc`

Remove the unnecessary borrow to satisfy clippy and improve code
cleanliness. No functional change.

Signed-off-by: Shivam Kalra <shivamklr@cock.li>
Acked-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260130182842.217821-1-shivamklr@cock.li
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-03 12:58:29 +01:00
Vasily Gorbik
f8a9c11000 s390/kexec: Emit an error message when cmdline is too long
Currently, if the command line passed to kexec_file_load() exceeds
the supported limit of the kernel being kexec'd, -EINVAL is returned
to userspace, which is consistent across architectures. Since
-EINVAL is not specific to this case, the kexec tool cannot provide
a specific reason for the failure. Many architectures emit an error
message in this case. Add a similar error message, including the
effective limit, since the command line length is configurable.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-02-03 12:48:28 +01:00
Halil Pasic
b8555fbc16 s390/configs: Enable BLK_DEV_NULL_BLK as module
Enable BLK_DEV_NULL_BLK as module in defconfig and debug_defconfig, so the
Null Test Block Device Driver can be easily used for testing purposes.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-02-03 12:48:28 +01:00
Heiko Carstens
cab7d81de3 s390: Document s390 stackprotector support
Recently [1] s390 got stackprotector support. Document this.

[1] commit f5730d44e0 ("s390: Add stackprotector support")

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-02-03 12:48:27 +01:00
Paolo Abeni
4906859dff Merge branch 'net-phy-remove-modalias-based-mdio-device-bus-matching'
Heiner Kallweit says:

====================
net: phy: remove modalias-based MDIO device bus matching

modalias-based MDIO device bus matching has only one user (dsa-loop),
where we can replace modalias-based matching with a simple custom
match function. This, and first patch of the series, lay the foundation
for removing modalias-based matching.
====================

Link: https://patch.msgid.link/d9543e7d-23e1-4dba-a6b3-35dcd6a35dec@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-03 12:46:57 +01:00
Heiner Kallweit
3051419f3d net: phy: remove modalias-based mdio bus matching
Last user dsa_loop has been migrated away from modalias-based matching,
so we can remove this feature now. It was the only user of MDIO_NAME_SIZE,
so remove also this constant.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://patch.msgid.link/ce1c6df0-4785-4b28-8322-32dc6bceea18@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-03 12:46:55 +01:00
Heiner Kallweit
5fddafbb92 net: dsa: loop: remove MDIO device modalias
This change is a prerequisite for removing the MDIO device modalias,
as dsa_loop is the only user. Switch from modalias to a custom
bus match function.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Tested-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://patch.msgid.link/15a4318f-50b5-4df5-874e-e387ee070a9d@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-03 12:46:55 +01:00
Heiner Kallweit
f7aa2ef10c net: ethernet: adi: make name member of struct adin1110_cfg a pointer
Primary reason for this change is to remove the misuse of MDIO_NAME_SIZE
here, so that this constant can be removed in a follow-up patch.
Use case here is simply a chip name w/o any relationship to a MDIO
device. Also there's no need to reserve a longer char array, so make
the name a pointer.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://patch.msgid.link/61bc14fa-eed3-43b6-ae40-b98063e81578@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-03 12:46:55 +01:00
Tzung-Bi Shih
988357628c revocable: Add KUnit test for concurrent access
Add a test case to verify correct synchronization between concurrent
readers and a revocation.

The test setup involves:
1. Consumer 1 enters the critical section (SRCU read lock) and verifies
   access to the resource.
2. Provider attempts to revoke the resource.  This should block until
   Consumer 1 releases the lock.
3. Consumer 2 attempts to enter the critical section while revocation
   is pending.  It should see the resource as revoked (NULL).
4. Consumer 1 exits, allowing the revocation to complete.

This ensures that the SRCU mechanism correctly enforces grace periods
and that new readers are properly prevented from accessing the resource
once revocation has begun.

A way to run the test:
$ ./tools/testing/kunit/kunit.py run \
	--kconfig_add CONFIG_REVOCABLE_KUNIT_TEST=y \
	--kconfig_add CONFIG_PROVE_LOCKING=y \
	--kconfig_add CONFIG_DEBUG_KERNEL=y \
	--kconfig_add CONFIG_DEBUG_INFO=y \
	--kconfig_add CONFIG_DEBUG_INFO_DWARF5=y \
	--kconfig_add CONFIG_KASAN=y \
	--kconfig_add CONFIG_DETECT_HUNG_TASK=y \
	--kconfig_add CONFIG_DEFAULT_HUNG_TASK_TIMEOUT="10" \
	--arch=x86_64 --raw_output=all \
	revocable_test

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://patch.msgid.link/20260129143733.45618-5-tzungbi@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-03 12:30:43 +01:00
Tzung-Bi Shih
377563ce06 revocable: fix SRCU index corruption by requiring caller-provided storage
The struct revocable handle stores the SRCU read-side index (idx) for
the duration of a resource access.  If multiple threads share the same
struct revocable instance, they race on writing to the idx field,
corrupting the SRCU state and potentially causing unsafe unlocks.

Refactor the API to replace revocable_alloc()/revocable_free() with
revocable_init()/revocable_deinit().  This change requires the caller
to provide the storage for struct revocable.

By moving storage ownership to the caller, the API ensures that
concurrent users maintain their own private idx storage, eliminating
the race condition.

Reported-by: Johan Hovold <johan@kernel.org>
Closes: https://lore.kernel.org/all/20260124170535.11756-4-johan@kernel.org/
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://patch.msgid.link/20260129143733.45618-4-tzungbi@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-03 12:30:43 +01:00
Tzung-Bi Shih
a243f7fb11 revocable: Add KUnit test for provider lifetime races
Add a test to verify that revocable_alloc() correctly handles race
conditions where the provider is being released.

The test covers three scenarios:
1. Allocating from a NULL provider.
2. Allocating from a provider that has been detached (pointer is NULL).
3. Allocating from a provider that is in the process of destruction
   (refcount is 0), simulating a race between revocable_alloc() and
   revocable_provider_release().

A way to run the test:
$ ./tools/testing/kunit/kunit.py run \
	--kconfig_add CONFIG_REVOCABLE_KUNIT_TEST=y \
	--kconfig_add CONFIG_PROVE_LOCKING=y \
	--kconfig_add CONFIG_DEBUG_KERNEL=y \
	--kconfig_add CONFIG_DEBUG_INFO=y \
	--kconfig_add CONFIG_DEBUG_INFO_DWARF5=y \
	--kconfig_add CONFIG_KASAN=y \
	--kconfig_add CONFIG_DETECT_HUNG_TASK=y \
	--kconfig_add CONFIG_DEFAULT_HUNG_TASK_TIMEOUT="10" \
	--arch=x86_64 --raw_output=all \
	revocable_test

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://patch.msgid.link/20260129143733.45618-3-tzungbi@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-03 12:30:43 +01:00
Tzung-Bi Shih
4d7dc4d1a6 revocable: Fix races in revocable_alloc() using RCU
There are two race conditions when allocating a revocable instance:

1. After a struct revocable_provider is revoked, the caller might still
   hold a dangling pointer to it.  A subsequent call to
   revocable_alloc() can trigger a use-after-free.
2. If revocable_provider_release() runs concurrently with
   revocable_alloc(), the memory of struct revocable_provider can be
   accessed during or after kfree().

To fix these:
- Manage the lifetime of struct revocable_provider using RCU.  Annotate
  pointers to it with __rcu and use kfree_rcu() for deallocation.
- Update revocable_alloc() to safely acquire a reference using RCU
  primitives.
- Update revocable_provider_revoke() to take a double pointer (`**rp`).
  It atomically NULLs out the caller's pointer before starting
  revocation.  This prevents the caller from holding a dangling pointer.
- Drop devm_revocable_provider_alloc().  The devm-managed model cannot
  support the required double-pointer semantic for safe pointer nulling.

Reported-by: Johan Hovold <johan@kernel.org>
Closes: https://lore.kernel.org/all/aXdy-b3GOJkzGqYo@hovoldconsulting.com/
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://patch.msgid.link/20260129143733.45618-2-tzungbi@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-03 12:30:43 +01:00
Micah Ostrow
ad9cb48b2b Input: apbps2 - fix comment style and typos
Capitalize comment starts to match kernel coding style.
Fix spelling: "reciever" -> "receiver"
Fix grammar: "it's" (contraction of "it is") -> "its" (possessive)
Remove uncertainty from "Clear error bits?" comment.

Compile tested only.

Signed-off-by: Micah Ostrow <bluefox9516@gmail.com>
Link: https://patch.msgid.link/20260127181735.57132-1-bluefox9516@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2026-02-03 03:05:43 -08:00
Zicheng Qu
e34881c84c sched: Re-evaluate scheduling when migrating queued tasks out of throttled cgroups
Consider the following sequence on a CPU configured with nohz_full:

1) A task P runs in cgroup A, and cgroup A becomes throttled due to CFS
   bandwidth control. The gse (cgroup A) where the task P attached is
dequeued and the CPU switches to idle.

2) Before cgroup A is unthrottled, task P is migrated from cgroup A to
   another cgroup B (not throttled).

   During sched_move_task(), the task P is observed as queued but not
running, and therefore no resched_curr() is triggered.

3) Since the CPU is nohz_full, it remains in do_idle() waiting for an
   explicit scheduling event, i.e., resched_curr().

4) For kernel <= 5.10: Later, cgroup A is unthrottled. However, the task
   P has already been migrated out of cgroup A, so unthrottle_cfs_rq()
may observe load_weight == 0 and return early without resched_curr()
called. For kernel >= 6.6: The unthrottling path normally triggers
`resched_curr()` almost cases even when no runnable tasks remain in the
unthrottled cgroup, preventing the idle stall described above. However,
if cgroup A is removed before it gets unthrottled, the unthrottling path
for cgroup A is never executed. In a result, no `resched_curr()` can be
called.

5) At this point, the task P is runnable in cgroup B (not throttled), but
the CPU remains in do_idle() with no pending reschedule point. The
system stays in this state until an unrelated event (e.g. a new task
wakeup or any cases) that can trigger a resched_curr() breaks the
nohz_full idle state, and then the task P finally gets scheduled.

The root cause is that sched_move_task() may classify the task as only
queued, not running, and therefore fails to trigger a resched_curr(),
while the later unthrottling path no longer has visibility of the
migrated task.

Preserve the existing behavior for running tasks by issuing
resched_curr(), and explicitly invoke check_preempt_curr() for tasks
that were queued at the time of migration. This ensures that runnable
tasks are reconsidered for scheduling even when nohz_full suppresses
periodic ticks.

Fixes: 29f59db3a7 ("sched: group-scheduler core")
Signed-off-by: Zicheng Qu <quzicheng@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>
Reviewed-by: Aaron Lu <ziqianlu@bytedance.com>
Tested-by: Aaron Lu <ziqianlu@bytedance.com>
Link: https://patch.msgid.link/20260130083438.1122457-1-quzicheng@huawei.com
2026-02-03 12:04:19 +01:00
zenghongling
742fe830b7 sched/cpufreq: Use %pe format for PTR_ERR() printing
Use %pe format specifier for printing PTR_ERR() error values
to make error messages more readable.

Found by Coccinelle:
./cpufreq_schedutil.c:685:49-56: WARNING: Consider using %pe to print PTR_ERR()

Signed-off-by: zenghongling <zenghongling@kylinos.cn>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260120083333.148385-1-zenghongling@kylinos.cn
2026-02-03 12:04:19 +01:00
Chen Jinghuang
94894c9c47 sched/rt: Skip currently executing CPU in rto_next_cpu()
CPU0 becomes overloaded when hosting a CPU-bound RT task, a non-CPU-bound
RT task, and a CFS task stuck in kernel space. When other CPUs switch from
RT to non-RT tasks, RT load balancing (LB) is triggered; with
HAVE_RT_PUSH_IPI enabled, they send IPIs to CPU0 to drive the execution
of rto_push_irq_work_func. During push_rt_task on CPU0,
if next_task->prio < rq->donor->prio, resched_curr() sets NEED_RESCHED
and after the push operation completes, CPU0 calls rto_next_cpu().
Since only CPU0 is overloaded in this scenario, rto_next_cpu() should
ideally return -1 (no further IPI needed).

However, multiple CPUs invoking tell_cpu_to_push() during LB increments
rd->rto_loop_next. Even when rd->rto_cpu is set to -1, the mismatch between
rd->rto_loop and rd->rto_loop_next forces rto_next_cpu() to restart its
search from -1. With CPU0 remaining overloaded (satisfying rt_nr_migratory
&& rt_nr_total > 1), it gets reselected, causing CPU0 to queue irq_work to
itself and send self-IPIs repeatedly. As long as CPU0 stays overloaded and
other CPUs run pull_rt_tasks(), it falls into an infinite self-IPI loop,
which triggers a CPU hardlockup due to continuous self-interrupts.

The trigging scenario is as follows:

         cpu0                      cpu1                    cpu2
                                pull_rt_task
                              tell_cpu_to_push
                 <------------irq_work_queue_on
rto_push_irq_work_func
       push_rt_task
    resched_curr(rq)                                   pull_rt_task
    rto_next_cpu                                     tell_cpu_to_push
                      <-------------------------- atomic_inc(rto_loop_next)
rd->rto_loop != next
     rto_next_cpu
   irq_work_queue_on
rto_push_irq_work_func

Fix redundant self-IPI by filtering the initiating CPU in rto_next_cpu().
This solution has been verified to effectively eliminate spurious self-IPIs
and prevent CPU hardlockup scenarios.

Fixes: 4bdced5c9a ("sched/rt: Simplify the IPI based RT balancing logic")
Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Suggested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Chen Jinghuang <chenjinghuang2@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Link: https://patch.msgid.link/20260122012533.673768-1-chenjinghuang2@huawei.com
2026-02-03 12:04:19 +01:00
Wangyang Guo
505da66893 sched/clock: Avoid false sharing for sched_clock_irqtime
Read-mostly sched_clock_irqtime may share the same cacheline with
frequently updated nohz struct. Make it as static_key to avoid
false sharing issue.

The only user of disable_sched_clock_irqtime()
is tsc_.*mark_unstable() which may be invoked under atomic context
and require a workqueue to disable static_key. But both of them
calls clear_sched_clock_stable() just before doing
disable_sched_clock_irqtime(). We can reuse
"sched_clock_work" to also disable sched_clock_irqtime().

One additional case need to handle is if the tsc is marked unstable
before late_initcall() phase, sched_clock_work will not be invoked
and sched_clock_irqtime will stay enabled although clock is unstable:
  tsc_init()
    enable_sched_clock_irqtime() # irqtime accounting is enabled here
    ...
    if (unsynchronized_tsc()) # true
      mark_tsc_unstable()
        clear_sched_clock_stable()
          __sched_clock_stable_early = 0;
          ...
          if (static_key_count(&sched_clock_running.key) == 2)
            # Only happens at sched_clock_init_late()
            __clear_sched_clock_stable(); # Never executed
  ...

  # late_initcall() phase
  sched_clock_init_late()
    if (__sched_clock_stable_early) # Already false
      __set_sched_clock_stable(); # sched_clock is never marked stable
  # TSC unstable, but sched_clock_work won't run to disable irqtime

So we need to disable_sched_clock_irqtime() in sched_clock_init_late()
if clock is unstable.

Reported-by: Benjamin Lei <benjamin.lei@intel.com>
Suggested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Wangyang Guo <wangyang.guo@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Reviewed-by: Tianyou Li <tianyou.li@intel.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://patch.msgid.link/20260127072509.2627346-1-wangyang.guo@intel.com
2026-02-03 12:04:19 +01:00
Joel Fernandes
dd6a37e8fa selftests/sched_ext: Add test for DL server total_bw consistency
Add a new kselftest to verify that the total_bw value in
/sys/kernel/debug/sched/debug remains consistent across all CPUs
under different sched_ext BPF program states:

1. Before a BPF scheduler is loaded
2. While a BPF scheduler is loaded and active
3. After a BPF scheduler is unloaded

The test runs CPU stress threads to ensure DL server bandwidth
values stabilize before checking consistency. This helps catch
potential issues with DL server bandwidth accounting during
sched_ext transitions.

Co-developed-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/20260126100050.3854740-8-arighi@nvidia.com
2026-02-03 12:04:18 +01:00
Andrea Righi
be621a7634 selftests/sched_ext: Add test for sched_ext dl_server
Add a selftest to validate the correct behavior of the deadline server
for the ext_sched_class.

Co-developed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/20260126100050.3854740-7-arighi@nvidia.com
2026-02-03 12:04:18 +01:00
Peter Zijlstra
5a40a9bb56 sched/debug: Fix dl_server (re)start conditions
There are two problems with sched_server_write_common() that can cause the
dl_server to malfunction upon attempting to change the parameters:

1) when, after having disabled the dl_server by setting runtime=0, it is
   enabled again while tasks are already enqueued. In this case is_active would
   still be 0 and dl_server_start() would not be called.

2) when dl_server_apply_params() would fail, runtime is not applied and does
   not reflect the new state.

Instead have dl_server_start() check its actual dl_runtime, and have
sched_server_write_common() unconditionally (re)start the dl_server. It will
automatically stop if there isn't anything to do, so spurious activation is
harmless -- while failing to start it is a problem.

While there, move the printk out of the locked region and make it symmetric,
also printing on enable.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260203103407.GK1282955@noisy.programming.kicks-ass.net
2026-02-03 12:04:18 +01:00
Joel Fernandes
76d12132ba sched/debug: Add support to change sched_ext server params
When a sched_ext server is loaded, tasks in the fair class are
automatically moved to the sched_ext class. Add support to modify the
ext server parameters similar to how the fair server parameters are
modified.

Re-use common code between ext and fair servers as needed.

Co-developed-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/20260126100050.3854740-6-arighi@nvidia.com
2026-02-03 12:04:17 +01:00
Andrea Righi
cd959a3562 sched_ext: Add a DL server for sched_ext tasks
sched_ext currently suffers starvation due to RT. The same workload when
converted to EXT can get zero runtime if RT is 100% running, causing EXT
processes to stall. Fix it by adding a DL server for EXT.

A kselftest is also included later to confirm that both DL servers are
functioning correctly:

 # ./runner -t rt_stall
 ===== START =====
 TEST: rt_stall
 DESCRIPTION: Verify that RT tasks cannot stall SCHED_EXT tasks
 OUTPUT:
 TAP version 13
 1..1
 # Runtime of FAIR task (PID 1511) is 0.250000 seconds
 # Runtime of RT task (PID 1512) is 4.750000 seconds
 # FAIR task got 5.00% of total runtime
 ok 1 PASS: FAIR task got more than 4.00% of runtime
 TAP version 13
 1..1
 # Runtime of EXT task (PID 1514) is 0.250000 seconds
 # Runtime of RT task (PID 1515) is 4.750000 seconds
 # EXT task got 5.00% of total runtime
 ok 2 PASS: EXT task got more than 4.00% of runtime
 TAP version 13
 1..1
 # Runtime of FAIR task (PID 1517) is 0.250000 seconds
 # Runtime of RT task (PID 1518) is 4.750000 seconds
 # FAIR task got 5.00% of total runtime
 ok 3 PASS: FAIR task got more than 4.00% of runtime
 TAP version 13
 1..1
 # Runtime of EXT task (PID 1521) is 0.250000 seconds
 # Runtime of RT task (PID 1522) is 4.750000 seconds
 # EXT task got 5.00% of total runtime
 ok 4 PASS: EXT task got more than 4.00% of runtime
 ok 1 rt_stall #
 =====  END  =====

Co-developed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/20260126100050.3854740-5-arighi@nvidia.com
2026-02-03 12:04:17 +01:00
Joel Fernandes
68ec89d0e9 sched/debug: Stop and start server based on if it was active
Currently the DL server interface for applying parameters checks
CFS-internals to identify if the server is active. This is error-prone
and makes it difficult when adding new servers in the future.

Fix it, by using dl_server_active() which is also used by the DL server
code to determine if the DL server was started.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Acked-by: Tejun Heo <tj@kernel.org>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/20260126100050.3854740-4-arighi@nvidia.com
2026-02-03 12:04:17 +01:00
Joel Fernandes
6080fb2116 sched/debug: Fix updating of ppos on server write ops
Updating "ppos" on error conditions does not make much sense. The pattern
is to return the error code directly without modifying the position, or
modify the position on success and return the number of bytes written.

Since on success, the return value of apply is 0, there is no point in
modifying ppos either. Fix it by removing all this and just returning
error code or number of bytes written on success.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Acked-by: Tejun Heo <tj@kernel.org>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/20260126100050.3854740-3-arighi@nvidia.com
2026-02-03 12:04:16 +01:00
Joel Fernandes
3cb3b27693 sched/deadline: Clear the defer params
The defer params were not cleared in __dl_clear_params. Clear them.

Without this is some of my test cases are flaking and the DL timer is
not starting correctly AFAICS.

Fixes: a110a81c52 ("sched/deadline: Deferrable dl server")
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/20260126100050.3854740-2-arighi@nvidia.com
2026-02-03 12:04:16 +01:00
Peter Zijlstra
3e4067169c Linux 6.19-rc8
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Merge branch 'v6.19-rc8'

Update to avoid conflicts with /urgent patches.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2026-02-03 12:04:13 +01:00
Deepanshu Kartikey
da6f5bbc2e gfs2: fix memory leaks in gfs2_fill_super error path
Fix two memory leaks in the gfs2_fill_super() error handling path when
transitioning a filesystem to read-write mode fails.

First leak: kthread objects (thread_struct, task_struct, etc.)
When gfs2_freeze_lock_shared() fails after init_threads() succeeds, the
created kernel threads (logd and quotad) are never destroyed. This
occurs because the fail_per_node label doesn't call
gfs2_destroy_threads().

Second leak: quota bitmap buffer (8192 bytes)
When gfs2_make_fs_rw() fails after gfs2_quota_init() succeeds but
before other operations complete, the allocated quota bitmap is never
freed.

The fix moves thread cleanup to the fail_per_node label to handle all
error paths uniformly. gfs2_destroy_threads() is safe to call
unconditionally as it checks for NULL pointers. Quota cleanup is added
in gfs2_make_fs_rw() to properly handle the withdrawal case where
quota initialization succeeds but the filesystem is then withdrawn.

Thread leak backtrace (gfs2_freeze_lock_shared failure):
  unreferenced object 0xffff88801d7bca80 (size 4480):
    copy_process+0x3a1/0x4670 kernel/fork.c:2422
    kernel_clone+0xf3/0x6e0 kernel/fork.c:2779
    kthread_create_on_node+0x100/0x150 kernel/kthread.c:478
    init_threads+0xab/0x350 fs/gfs2/ops_fstype.c:611
    gfs2_fill_super+0xe5c/0x1240 fs/gfs2/ops_fstype.c:1265

Quota leak backtrace (gfs2_make_fs_rw failure):
  unreferenced object 0xffff88812de7c000 (size 8192):
    gfs2_quota_init+0xe5/0x820 fs/gfs2/quota.c:1409
    gfs2_make_fs_rw+0x7a/0xe0 fs/gfs2/super.c:149
    gfs2_fill_super+0xfbb/0x1240 fs/gfs2/ops_fstype.c:1275

Reported-by: syzbot+aac438d7a1c44071e04b@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=aac438d7a1c44071e04b
Fixes: 6c7410f449 ("gfs2: gfs2_freeze_lock_shared cleanup")
Fixes: b66f723bb5 ("gfs2: Improve gfs2_make_fs_rw error handling")
Link: https://lore.kernel.org/all/20260131062509.77974-1-kartikey406@gmail.com/T/ [v1]
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2026-02-03 10:57:54 +01:00
Breno Leitao
53c998527f arm64/gcs: Fix error handling in arch_set_shadow_stack_status()
alloc_gcs() returns an error-encoded pointer on failure, which comes
from do_mmap(), not NULL.

The current NULL check fails to detect errors, which could lead to using
an invalid GCS address.

Use IS_ERR_VALUE() to properly detect errors, consistent with the
check in gcs_alloc_thread_stack().

Fixes: b57180c75c ("arm64/gcs: Implement shadow stack prctl() interface")
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Will Deacon <will@kernel.org>
2026-02-03 09:30:20 +00:00
Nathan Chancellor
45c0a8a702
drm/panel: ilitek-ili9882t: Remove duplicate initializers in tianma_il79900a_dsc
Clang warns (or errors with CONFIG_WERROR=y / W=e):

  drivers/gpu/drm/panel/panel-ilitek-ili9882t.c:95:16: error: initializer overrides prior initialization of this subobject [-Werror,-Winitializer-overrides]
     95 |         .vbr_enable = 0,
        |                       ^
  drivers/gpu/drm/panel/panel-ilitek-ili9882t.c:90:16: note: previous initialization is here
     90 |         .vbr_enable = false,
        |                       ^~~~~
  drivers/gpu/drm/panel/panel-ilitek-ili9882t.c:97:19: error: initializer overrides prior initialization of this subobject [-Werror,-Winitializer-overrides]
     97 |         .rc_model_size = DSC_RC_MODEL_SIZE_CONST,
        |                          ^~~~~~~~~~~~~~~~~~~~~~~
  include/drm/display/drm_dsc.h:22:38: note: expanded from macro 'DSC_RC_MODEL_SIZE_CONST'
     22 | #define DSC_RC_MODEL_SIZE_CONST             8192
        |                                             ^~~~
  drivers/gpu/drm/panel/panel-ilitek-ili9882t.c:91:19: note: previous initialization is here
     91 |         .rc_model_size = DSC_RC_MODEL_SIZE_CONST,
        |                          ^~~~~~~~~~~~~~~~~~~~~~~
  include/drm/display/drm_dsc.h:22:38: note: expanded from macro 'DSC_RC_MODEL_SIZE_CONST'
     22 | #define DSC_RC_MODEL_SIZE_CONST             8192
        |                                             ^~~~
  drivers/gpu/drm/panel/panel-ilitek-ili9882t.c:132:25: error: initializer overrides prior initialization of this subobject [-Werror,-Winitializer-overrides]
    132 |         .initial_scale_value = 32,
        |                                ^~
  drivers/gpu/drm/panel/panel-ilitek-ili9882t.c:126:25: note: previous initialization is here
    126 |         .initial_scale_value = 32,
        |                                ^~
  drivers/gpu/drm/panel/panel-ilitek-ili9882t.c:133:20: error: initializer overrides prior initialization of this subobject [-Werror,-Winitializer-overrides]
    133 |         .nfl_bpg_offset = 3511,
        |                           ^~~~
  drivers/gpu/drm/panel/panel-ilitek-ili9882t.c:108:20: note: previous initialization is here
    108 |         .nfl_bpg_offset = 1402,
        |                           ^~~~

GCC would warn about this in the same manner but its version,
-Woverride-init, is disabled for a normal kernel build in
scripts/Makefile.warn. For clang, -Wextra in drivers/gpu/drm/Makefile
turns it back but GCC respects turning it off earlier in the command
line.

Of all the duplicate fields in the initializer, only nfl_bpg_offset is a
different value. Clear up the duplicate initializers, keeping the
'false' value for .vbr_enable, as it is bool, and the second value for
.nfl_bpg_offset, assuming it is the correct one since it was the one
tested in the original change.

Fixes: 65ce1f5834 ("drm/panel: ilitek-ili9882t: Switch Tianma TL121BVMS07 to DSC 120Hz mode")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20260114-panel-ilitek-ili9882t-fix-override-init-v1-1-1d69a2b096df@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2026-02-03 10:03:22 +01:00
Sebastian Andrzej Siewior
ef92b98f5f media: pci: mg4b: Use IRQF_NO_THREAD
The interrupt handler iio_trigger_generic_data_rdy_poll() will invoke other
interrupt handlers and this supposed to happen from hard interrupt context.

Use IRQF_NO_THREAD to forbid forced-threading.

Fixes: 0ab13674a9 ("media: pci: mgb4: Added Digiteq Automotive MGB4 driver")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260128095540.863589-21-bigeasy@linutronix.de
2026-02-03 09:20:55 +01:00
Qu Wenruo
161ab30da6 btrfs: get rid of compressed_bio::compressed_folios[]
Now there is no one utilizing that member, we can safely remove it along
with compressed_bio::nr_folios member. The size is reduced from 352 to
336 bytes on x86_64.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:59:07 +01:00
Qu Wenruo
e1bc83f8b1 btrfs: get rid of compressed_folios[] usage for encoded writes
Currently only encoded writes utilized btrfs_submit_compressed_write(),
which utilized compressed_bio::compressed_folios[] array.

Change the only call site to call the new helper,
btrfs_alloc_compressed_write(), to allocate a compressed bio, then queue
needed folios into that bio, and finally call
btrfs_submit_compressed_write() to submit the compressed bio.

This change has one hidden benefit, previously we used
btrfs_alloc_folio_array() for the folios of
btrfs_submit_compressed_read(), which doesn't utilize the compression
page pool for bs == ps cases.

Now we call btrfs_alloc_compr_folio() which will benefit from the page pool.

The other obvious benefit is that we no longer need to allocate an array
to hold all those folios, thus one less error path.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:59:07 +01:00
Qu Wenruo
dafcfa1c8e btrfs: get rid of compressed_folios[] usage for compressed read
Currently btrfs_submit_compressed_read() still uses
compressed_bio::compressed_folios[] array.

Change it to allocate each folio and queue them into the compressed bio
so that we do not need to allocate that array.

Considering how small each compressed read bio is (less than 128KiB), we
do not benefit that much from btrfs_alloc_folio_array() anyway,
while we may benefit more from btrfs_alloc_compr_folio() by using
the global folio pool.

So changing from btrfs_alloc_folio_array() to btrfs_alloc_compr_folio()
in a loop should still be fine.

This removes one error path, and paves the way to completely remove
compressed_folios[] array.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:59:07 +01:00
Qu Wenruo
26902be0cd btrfs: remove the old btrfs_compress_folios() infrastructure
Since it's been replaced by btrfs_compress_bio(), remove all involved
functions.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:59:07 +01:00
Qu Wenruo
6f706f34fc btrfs: switch to btrfs_compress_bio() interface for compressed writes
This switch has the following benefits:

- A single structure to handle all compression

  No more extra members like compressed_folios[] nor compress_type, all
  those members.

  This means the structure of async_extent is much smaller.

- Simpler error handling

  A single cleanup_compressed_bio() will handle everything, no extra
  compressed_folios[] array to bother.

Some extra notes:

- Compressed folios releasing

  Now we go bio_for_each_folio_all() loop to release the folios of the
  bio. This will work for both the old compressed_folios[] array and the
  new pure bio method.

  For old compressed_folios[], all folios of that array is queued into
  the bio, thus releasing the folios from the bio is the same as
  releasing each folio of that array. We just need to be sure no double
  releasing from the array and bio.

  For the new pure bio method, that array is NULL, just usual folio
  releasing of the bio.

  The only extra note is for end_bbio_compressed_read(), as the folios
  are allocated using btrfs_alloc_folio_array(), thus the folios should
  only be released by regular folio_put(), not btrfs_free_compr_folio().

- Rounding up the bio to block size

  We cannot simply increase bi_size, as that will not increase the
  length of the last bvec.

  Thus we have to properly add the last part into the bio.
  This will be done by the helper, round_up_last_block().

  The reason we do not round those bios up at compression time is to get
  the unaligned compressed size, so that they can be utilized for
  inline extents.
  If we round the bios up at *_compress_bio(), then every compressed bio
  will be larger than or equal to one fs block, resulting no inline
  compressed extent.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:59:07 +01:00
Qu Wenruo
c51173271d btrfs: introduce btrfs_compress_bio() helper
The helper will allocate a new compressed_bio, do the compression, and
return it to the caller.

This greatly simplifies the compression path, as we no longer need to
allocate a folio array thus no extra error path, furthermore the
compressed bio structure can be utilized for submission with very minor
modifications (like rounding up the bi_size and populate the bi_sector).

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:59:06 +01:00
Qu Wenruo
3d74a7556f btrfs: zlib: introduce zlib_compress_bio() helper
The new helper has the following enhancements against the existing
zlib_compress_folios()

- Much smaller parameter list

  No more shared IN/OUT members, no need to pre-allocate a
  compressed_folios[] array.

  Just a workspace and compressed_bio pointer, everything we need can be
  extracted from that @cb pointer.

- Ready-to-be-submitted compressed bio

  Although the caller still needs to do some common works like
  rounding up and zeroing the tailing part of the last fs block.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:59:06 +01:00
Qu Wenruo
bba959655a btrfs: zstd: introduce zstd_compress_bio() helper
The new helper has the following enhancements against the existing
zstd_compress_folios()

- Much smaller parameter list

  No more shared IN/OUT members, no need to pre-allocate a
  compressed_folios[] array.

  Just a workspace and compressed_bio pointer, everything we need can be
  extracted from that @cb pointer.

- Ready-to-be-submitted compressed bio

  Although the caller still needs to do some common works like
  rounding up and zeroing the tailing part of the last fs block.

Overall the workflow is the same as zstd_compress_folios(), but with
some minor changes:

- @start/@len is now constant
  For the current input file offset, use @start + @tot_in instead.

  The original change of @start and @len makes it pretty hard to know
  what value we're really comparing to.

- No more @cur_len
  It's only utilized when switching input buffer.
  Directly use btrfs_calc_input_length() instead.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:59:06 +01:00
Qu Wenruo
3be8a788ee btrfs: lzo: introduce lzo_compress_bio() helper
The new helper has the following enhancements against the existing
lzo_compress_folios()

- Much smaller parameter list

  No more shared IN/OUT members, no need to pre-allocate a
  compressed_folios[] array.

  Just a workspace list header and a compressed_bio pointer.

  Everything else can be fetched from that @cb pointer.

- Read-to-be-submitted compressed bio

  Although the caller still needs to do some common works like
  rounding up and zeroing the tailing part of the last fs block.

Some workloads are specific to lZO that is not needed with other
multi-run compression interfaces:

- Need to write a LZO header or segment header

  Use the new write_and_queue_folio() helper to do the bio_add_folio()
  call and folio switching.

- Need to update the LZO header after compression is done

  Use bio_first_folio_all() to grab the first folio and update the header.

- Extra corner case of error handling

  This can happen when we have queued part of a folio and hit an error.
  In that case those folios will be released by the bio.
  Thus we can only release the folio that has no queued part.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:59:06 +01:00
Naohiro Aota
e8f6130419 btrfs: zoned: factor out the zone loading part into a testable function
Separate btrfs_load_block_group_* calling path into a function, so that it
can be an entry point of unit test.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:59:06 +01:00
Naohiro Aota
e564cd2511 btrfs: add cleanup function for btrfs_free_chunk_map
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:59:06 +01:00
Naohiro Aota
392431cf9c btrfs: tests: add cleanup functions for test specific functions
Add auto-cleanup helper functions for btrfs_free_dummy_fs_info and
btrfs_free_dummy_block_group.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:59:05 +01:00
Filipe Manana
a56a70f8d2 btrfs: raid56: fix memory leak of btrfs_raid_bio::stripe_uptodate_bitmap
We allocate the bitmap but we never free it in free_raid_bio_pointers().
Fix this by adding a bitmap_free() call against the stripe_uptodate_bitmap
of a raid bio.

Fixes: 1810350b04 ("btrfs: raid56: move sector_ptr::uptodate into a dedicated bitmap")
Reported-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/linux-btrfs/20260126045315.GA31641@lst.de/
Reviewed-by: Qu Wenruo <wqu@suse.com>
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:56:25 +01:00
Boris Burkov
5341c98450 btrfs: tests: add unit tests for pending extent walking functions
I ran into another sort of trivial bug in v1 of the patch and concluded
that these functions really ought to be unit tested.

These two functions form the core of searching the chunk allocation
pending extent bitmap and have relatively easily definable semantics, so
unit testing them can help ensure the correctness of chunk allocation.

I also made a minor unrelated fix in volumes.h to properly forward
declare btrfs_space_info. Because of the order of the includes in the
new test, this was actually hitting a latent build warning.

Note:
This is an early example for me of a commit authored in part by an AI
agent, so I wanted to more clear about what I did. I defined a
trivial test and explained the set of tests I wanted to the agent and it
produced the large set of test cases seen here. I then checked each test
case to make sure it matched the description and simplified the
constants and numbers until they looked reasonable to me. I then checked
the looping logic to make sure it made sense to the original spirit of
the trivial test. Finally, carefully combed over all the lines it wrote
to loop over the tests it generated to make sure they followed our code
style guide.

Assisted-by: Claude:claude-opus-4-5
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:56:25 +01:00
Boris Burkov
b14c5e04bd btrfs: fix EEXIST abort due to non-consecutive gaps in chunk allocation
I have been observing a number of systems aborting at
insert_dev_extents() in btrfs_create_pending_block_groups(). The
following is a sample stack trace of such an abort coming from forced
chunk allocation (typically behind CONFIG_BTRFS_EXPERIMENTAL) but this
can theoretically happen to any DUP chunk allocation.

  [81.801] ------------[ cut here ]------------
  [81.801] BTRFS: Transaction aborted (error -17)
  [81.801] WARNING: fs/btrfs/block-group.c:2876 at btrfs_create_pending_block_groups+0x721/0x770 [btrfs], CPU#1: bash/319
  [81.802] Modules linked in: virtio_net btrfs xor zstd_compress raid6_pq null_blk
  [81.803] CPU: 1 UID: 0 PID: 319 Comm: bash Kdump: loaded Not tainted 6.19.0-rc6+ #319 NONE
  [81.803] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014
  [81.804] RIP: 0010:btrfs_create_pending_block_groups+0x723/0x770 [btrfs]
  [81.806] RSP: 0018:ffffa36241a6bce8 EFLAGS: 00010282
  [81.806] RAX: 000000000000000d RBX: ffff8e699921e400 RCX: 0000000000000000
  [81.807] RDX: 0000000002040001 RSI: 00000000ffffffef RDI: ffffffffc0608bf0
  [81.807] RBP: 00000000ffffffef R08: ffff8e69830f6000 R09: 0000000000000007
  [81.808] R10: ffff8e699921e5e8 R11: 0000000000000000 R12: ffff8e6999228000
  [81.808] R13: ffff8e6984d82000 R14: ffff8e69966a69c0 R15: ffff8e69aa47b000
  [81.809] FS:  00007fec6bdd9740(0000) GS:ffff8e6b1b379000(0000) knlGS:0000000000000000
  [81.809] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [81.810] CR2: 00005604833670f0 CR3: 0000000116679000 CR4: 00000000000006f0
  [81.810] Call Trace:
  [81.810]  <TASK>
  [81.810]  __btrfs_end_transaction+0x3e/0x2b0 [btrfs]
  [81.811]  btrfs_force_chunk_alloc_store+0xcd/0x140 [btrfs]
  [81.811]  kernfs_fop_write_iter+0x15f/0x240
  [81.812]  vfs_write+0x264/0x500
  [81.812]  ksys_write+0x6c/0xe0
  [81.812]  do_syscall_64+0x66/0x770
  [81.812]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
  [81.813] RIP: 0033:0x7fec6be66197
  [81.814] RSP: 002b:00007fffb159dd30 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
  [81.815] RAX: ffffffffffffffda RBX: 00007fec6bdd9740 RCX: 00007fec6be66197
  [81.815] RDX: 0000000000000002 RSI: 0000560483374f80 RDI: 0000000000000001
  [81.816] RBP: 0000560483374f80 R08: 0000000000000000 R09: 0000000000000000
  [81.816] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
  [81.817] R13: 00007fec6bfb85c0 R14: 00007fec6bfb5ee0 R15: 00005604833729c0
  [81.817]  </TASK>
  [81.817] irq event stamp: 20039
  [81.818] hardirqs last  enabled at (20047): [<ffffffff99a68302>] __up_console_sem+0x52/0x60
  [81.818] hardirqs last disabled at (20056): [<ffffffff99a682e7>] __up_console_sem+0x37/0x60
  [81.819] softirqs last  enabled at (19470): [<ffffffff999d2b46>] __irq_exit_rcu+0x96/0xc0
  [81.819] softirqs last disabled at (19463): [<ffffffff999d2b46>] __irq_exit_rcu+0x96/0xc0
  [81.820] ---[ end trace 0000000000000000 ]---
  [81.820] BTRFS: error (device dm-7 state A) in btrfs_create_pending_block_groups:2876: errno=-17 Object already exists

Inspecting these aborts with drgn, I observed a pattern of overlapping
chunk_maps. Note how stripe 1 of the first chunk overlaps in physical
address with stripe 0 of the second chunk.

Physical Start     Physical End       Length       Logical            Type                 Stripe
----------------------------------------------------------------------------------------------------
0x0000000102500000 0x0000000142500000 1.0G         0x0000000641d00000 META|DUP             0/2
0x0000000142500000 0x0000000182500000 1.0G         0x0000000641d00000 META|DUP             1/2
0x0000000142500000 0x0000000182500000 1.0G         0x0000000601d00000 META|DUP             0/2
0x0000000182500000 0x00000001c2500000 1.0G         0x0000000601d00000 META|DUP             1/2

Now how could this possibly happen? All chunk allocation is protected by
the chunk_mutex so racing allocations should see a consistent view of
the CHUNK_ALLOCATED bit in the chunk allocation extent-io-tree
(device->alloc_state as set by chunk_map_device_set_bits()) The tree
itself is protected by a spin lock, and clearing/setting the bits is
always protected by fs_info->mapping_tree_lock, so no race is apparent.

It turns out that there is a subtle bug in the logic regarding chunk
allocations that have happened in the current transaction, known as
"pending extents". The chunk allocation as defined in
find_free_dev_extent() is a loop which searches the commit root of the
dev_root and looks for gaps between DEV_EXTENT items. For those gaps, it
then checks alloc_state bitmap for any pending extents and adjusts the
hole that it finds accordingly. However, the logic in that adjustment
assumes that the first pending extent is the only one in that range.

e.g., given a layout with two non-consecutive pending extents in a hole
passed to dev_extent_hole_check() via *hole_start and *hole_size:

  |----pending A----|    real hole     |----pending B----|
           |           candidate hole        |
      *hole_start                         *hole_start + *hole_size

the code incorrectly returns a "hole" from the end of pending extent A
until the passed in hole end, failing to account for pending B.

However, it is not entirely obvious that it is actually possible to
produce such a layout. I was able to reproduce it, but with some
contortions: I continued to use the force chunk allocation sysfs file
and I introduced a long delay (10 seconds) into the start of the cleaner
thread. I also prevented the unused bgs cleaning logic from ever
deleting metadata bgs. These help make it easier to deterministically
produce the condition but shouldn't really matter if you imagine the
conditions happening by race/luck. Allocations/frees can happen
concurrently with the cleaner thread preparing to process an unused
extent and both create some used chunks with an unused chunk
interleaved, all during one transaction. Then btrfs_delete_unused_bgs()
sees the unused one and clears it, leaving a range with several pending
chunk allocations and a gap in the middle.

The basic idea is that the unused_bgs cleanup work happens on a worker
so if we allocate 3 block groups in one transaction, then the cleaner
work kicked off by the previous transaction comes through and deletes
the middle one of the 3, then the commit root shows no dev extents and
we have the bad pattern in the extent-io-tree. One final consideration
is that the code happens to loop to the next hole if there are no more
extents at all, so we need one more dev extent way past the area we are
working in. Something like the following demonstrates the technique:

  # push the BG frontier out to 20G
  fallocate -l 20G $mnt/foo
  # allocate one more that will prevent the "no more dev extents" luck
  fallocate -l 1G $mnt/sticky
  # sync
  sync
  # clear out the allocation area
  rm $mnt/foo
  sync
  _cleaner
  # let everything quiesce
  sleep 20
  sync

  # dev tree should have one bg 20G out and the rest at the beginning..
  # sort of like an empty FS but with a random sticky chunk.

  # kick off the cleaner in the background, remember it will sleep 10s
  # before doing interesting work
  _cleaner &

  sleep 3

  # create 3 trivial block groups, all empty, all immediately marked as unused.
  echo 1 > "$(_btrfs_sysfs_space_info $dev metadata)/force_chunk_alloc"
  echo 1 > "$(_btrfs_sysfs_space_info $dev data)/force_chunk_alloc"
  echo 1 > "$(_btrfs_sysfs_space_info $dev metadata)/force_chunk_alloc"

  # let the cleaner thread definitely finish, it will remove the data bg
  sleep 10

  # this allocation sees the non-consecutive pending metadata chunks with
  # data chunk gap of 1G and allocates a 2G extent in that hole. ENOSPC!
  echo 1 > "$(_btrfs_sysfs_space_info $dev metadata)/force_chunk_alloc"

As for the fix, it is not that obvious. I could not see a trivial way to
do it even by adding backup loops into find_free_dev_extent(), so I
opted to change the semantics of dev_extent_hole_check() to not stop
looping until it finds a sufficiently big hole. For clarity, this also
required changing the helper function contains_pending_extent() into two
new helpers which find the first pending extent and the first suitable
hole in a range.

I attempted to clean up the documentation and range calculations to be
as consistent and clear as possible for the future.

I also looked at the zoned case and concluded that the loop there is
different and not to be unified with this one. As far as I can tell, the
zoned check will only further constrain the hole so looping back to find
more holes is acceptable. Though given that zoned really only appends, I
find it highly unlikely that it is susceptible to this bug.

Fixes: 1b98450816 ("Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole")
Reported-by: Dimitrios Apostolou <jimis@gmx.net>
Closes: https://lore.kernel.org/linux-btrfs/q7760374-q1p4-029o-5149-26p28421s468@tzk.arg/
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:56:25 +01:00
jinbaohong
b291ad4458 btrfs: fix transaction commit blocking during trim of unallocated space
When trimming unallocated space, btrfs_trim_fs() holds the device_list_mutex
for the entire duration while iterating through all devices. On large
filesystems with significant unallocated space, this operation can take
minutes to hours on large storage systems.

This causes a problem because btrfs_run_dev_stats(), which is called
during transaction commit, also requires device_list_mutex:

  btrfs_trim_fs()
    mutex_lock(&fs_devices->device_list_mutex)
    list_for_each_entry(device, ...)
      btrfs_trim_free_extents(device)
    mutex_unlock(&fs_devices->device_list_mutex)

  commit_transaction()
    btrfs_run_dev_stats()
      mutex_lock(&fs_devices->device_list_mutex)  // blocked!
      ...

While trim is running, all transaction commits are blocked waiting for
the mutex.

Fix this by refactoring btrfs_trim_free_extents() to process devices in
bounded chunks (up to 2GB per iteration) and release device_list_mutex
between chunks.

Signed-off-by: robbieko <robbieko@synology.com>
Signed-off-by: jinbaohong <jinbaohong@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:56:25 +01:00
jinbaohong
bfb670b918 btrfs: handle user interrupt properly in btrfs_trim_fs()
When a fatal signal is pending or the process is freezing,
btrfs_trim_block_group() and btrfs_trim_free_extents() return -ERESTARTSYS.
Currently this is treated as a regular error: the loops continue to the
next iteration and count it as a block group or device failure.

Instead, break out of the loops immediately and return -ERESTARTSYS to
userspace without counting it as a failure. Also skip the device loop
entirely if the block group loop was interrupted.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: jinbaohong <jinbaohong@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:56:25 +01:00
jinbaohong
1cc4ada418 btrfs: preserve first error in btrfs_trim_fs()
When multiple block groups or devices fail during trim, preserve the
first error encountered rather than the last one. The first error is
typically more useful for debugging as it represents the original
failure, while subsequent errors may be cascading effects.

Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: jinbaohong <jinbaohong@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:56:24 +01:00
jinbaohong
912d1c6680 btrfs: continue trimming remaining devices on failure
Commit 93bba24d4b ("btrfs: Enhance btrfs_trim_fs function to handle
error better") intended to make device trimming continue even if one
device fails, tracking failures and reporting them at the end. However,
it used 'break' instead of 'continue', causing the loop to exit on the
first device failure.

Fix this by replacing 'break' with 'continue'.

Fixes: 93bba24d4b ("btrfs: Enhance btrfs_trim_fs function to handle error better")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: jinbaohong <jinbaohong@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2026-02-03 07:56:24 +01:00