* FAILED: patch "[PATCH] dm-bufio: don't schedule in atomic context" failed to apply to 6.1-stable tree
@ 2025-05-05 7:38 gregkh
2025-05-05 9:20 ` [PATCH v6.1] dm-bufio: don't schedule in atomic context Mikulas Patocka
0 siblings, 1 reply; 2+ messages in thread
From: gregkh @ 2025-05-05 7:38 UTC (permalink / raw)
To: weilongping, mpatocka; +Cc: stable
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x a3d8f0a7f5e8b193db509c7191fefeed3533fc44
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025050552-backslid-thirsting-324d@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a3d8f0a7f5e8b193db509c7191fefeed3533fc44 Mon Sep 17 00:00:00 2001
From: LongPing Wei <weilongping@oppo.com>
Date: Thu, 17 Apr 2025 11:07:38 +0800
Subject: [PATCH] dm-bufio: don't schedule in atomic context
A BUG was reported as below when CONFIG_DEBUG_ATOMIC_SLEEP and
try_verify_in_tasklet are enabled.
[ 129.444685][ T934] BUG: sleeping function called from invalid context at drivers/md/dm-bufio.c:2421
[ 129.444723][ T934] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 934, name: kworker/1:4
[ 129.444740][ T934] preempt_count: 201, expected: 0
[ 129.444756][ T934] RCU nest depth: 0, expected: 0
[ 129.444781][ T934] Preemption disabled at:
[ 129.444789][ T934] [<ffffffd816231900>] shrink_work+0x21c/0x248
[ 129.445167][ T934] kernel BUG at kernel/sched/walt/walt_debug.c:16!
[ 129.445183][ T934] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
[ 129.445204][ T934] Skip md ftrace buffer dump for: 0x1609e0
[ 129.447348][ T934] CPU: 1 PID: 934 Comm: kworker/1:4 Tainted: G W OE 6.6.56-android15-8-o-g6f82312b30b9-debug #1 1400000003000000474e5500b3187743670464e8
[ 129.447362][ T934] Hardware name: Qualcomm Technologies, Inc. Parrot QRD, Alpha-M (DT)
[ 129.447373][ T934] Workqueue: dm_bufio_cache shrink_work
[ 129.447394][ T934] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 129.447406][ T934] pc : android_rvh_schedule_bug+0x0/0x8 [sched_walt_debug]
[ 129.447435][ T934] lr : __traceiter_android_rvh_schedule_bug+0x44/0x6c
[ 129.447451][ T934] sp : ffffffc0843dbc90
[ 129.447459][ T934] x29: ffffffc0843dbc90 x28: ffffffffffffffff x27: 0000000000000c8b
[ 129.447479][ T934] x26: 0000000000000040 x25: ffffff804b3d6260 x24: ffffffd816232b68
[ 129.447497][ T934] x23: ffffff805171c5b4 x22: 0000000000000000 x21: ffffffd816231900
[ 129.447517][ T934] x20: ffffff80306ba898 x19: 0000000000000000 x18: ffffffc084159030
[ 129.447535][ T934] x17: 00000000d2b5dd1f x16: 00000000d2b5dd1f x15: ffffffd816720358
[ 129.447554][ T934] x14: 0000000000000004 x13: ffffff89ef978000 x12: 0000000000000003
[ 129.447572][ T934] x11: ffffffd817a823c4 x10: 0000000000000202 x9 : 7e779c5735de9400
[ 129.447591][ T934] x8 : ffffffd81560d004 x7 : 205b5d3938373434 x6 : ffffffd8167397c8
[ 129.447610][ T934] x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffffffc0843db9e0
[ 129.447629][ T934] x2 : 0000000000002f15 x1 : 0000000000000000 x0 : 0000000000000000
[ 129.447647][ T934] Call trace:
[ 129.447655][ T934] android_rvh_schedule_bug+0x0/0x8 [sched_walt_debug 1400000003000000474e550080cce8a8a78606b6]
[ 129.447681][ T934] __might_resched+0x190/0x1a8
[ 129.447694][ T934] shrink_work+0x180/0x248
[ 129.447706][ T934] process_one_work+0x260/0x624
[ 129.447718][ T934] worker_thread+0x28c/0x454
[ 129.447729][ T934] kthread+0x118/0x158
[ 129.447742][ T934] ret_from_fork+0x10/0x20
[ 129.447761][ T934] Code: ???????? ???????? ???????? d2b5dd1f (d4210000)
[ 129.447772][ T934] ---[ end trace 0000000000000000 ]---
dm_bufio_lock will call spin_lock_bh when try_verify_in_tasklet
is enabled, and __scan will be called in atomic context.
Fixes: 7cd326747f46 ("dm bufio: remove dm_bufio_cond_resched()")
Signed-off-by: LongPing Wei <weilongping@oppo.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index 9c8ed65cd87e..f0b5a6931161 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -68,6 +68,8 @@
#define LIST_DIRTY 1
#define LIST_SIZE 2
+#define SCAN_RESCHED_CYCLE 16
+
/*--------------------------------------------------------------*/
/*
@@ -2424,7 +2426,12 @@ static void __scan(struct dm_bufio_client *c)
atomic_long_dec(&c->need_shrink);
freed++;
- cond_resched();
+
+ if (unlikely(freed % SCAN_RESCHED_CYCLE == 0)) {
+ dm_bufio_unlock(c);
+ cond_resched();
+ dm_bufio_lock(c);
+ }
}
}
}
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH v6.1] dm-bufio: don't schedule in atomic context
2025-05-05 7:38 FAILED: patch "[PATCH] dm-bufio: don't schedule in atomic context" failed to apply to 6.1-stable tree gregkh
@ 2025-05-05 9:20 ` Mikulas Patocka
0 siblings, 0 replies; 2+ messages in thread
From: Mikulas Patocka @ 2025-05-05 9:20 UTC (permalink / raw)
To: gregkh; +Cc: weilongping, stable
On Mon, 5 May 2025, gregkh@linuxfoundation.org wrote:
>
> The patch below does not apply to the 6.1-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
Hi.
Here I'm sending a backport of upstream patch
a3d8f0a7f5e8b193db509c7191fefeed3533fc44 for the branch 6.1.
A BUG was reported as below when CONFIG_DEBUG_ATOMIC_SLEEP and
try_verify_in_tasklet are enabled.
[ 129.444685][ T934] BUG: sleeping function called from invalid context at drivers/md/dm-bufio.c:2421
[ 129.444723][ T934] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 934, name: kworker/1:4
[ 129.444740][ T934] preempt_count: 201, expected: 0
[ 129.444756][ T934] RCU nest depth: 0, expected: 0
[ 129.444781][ T934] Preemption disabled at:
[ 129.444789][ T934] [<ffffffd816231900>] shrink_work+0x21c/0x248
[ 129.445167][ T934] kernel BUG at kernel/sched/walt/walt_debug.c:16!
[ 129.445183][ T934] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
[ 129.445204][ T934] Skip md ftrace buffer dump for: 0x1609e0
[ 129.447348][ T934] CPU: 1 PID: 934 Comm: kworker/1:4 Tainted: G W OE 6.6.56-android15-8-o-g6f82312b30b9-debug #1 1400000003000000474e5500b3187743670464e8 [ 129.447362][ T934] Hardware name: Qualcomm Technologies, Inc. Parrot QRD, Alpha-M (DT)
[ 129.447373][ T934] Workqueue: dm_bufio_cache shrink_work
[ 129.447394][ T934] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 129.447406][ T934] pc : android_rvh_schedule_bug+0x0/0x8 [sched_walt_debug]
[ 129.447435][ T934] lr : __traceiter_android_rvh_schedule_bug+0x44/0x6c
[ 129.447451][ T934] sp : ffffffc0843dbc90
[ 129.447459][ T934] x29: ffffffc0843dbc90 x28: ffffffffffffffff x27: 0000000000000c8b
[ 129.447479][ T934] x26: 0000000000000040 x25: ffffff804b3d6260 x24: ffffffd816232b68
[ 129.447497][ T934] x23: ffffff805171c5b4 x22: 0000000000000000 x21: ffffffd816231900
[ 129.447517][ T934] x20: ffffff80306ba898 x19: 0000000000000000 x18: ffffffc084159030
[ 129.447535][ T934] x17: 00000000d2b5dd1f x16: 00000000d2b5dd1f x15: ffffffd816720358
[ 129.447554][ T934] x14: 0000000000000004 x13: ffffff89ef978000 x12: 0000000000000003
[ 129.447572][ T934] x11: ffffffd817a823c4 x10: 0000000000000202 x9 : 7e779c5735de9400
[ 129.447591][ T934] x8 : ffffffd81560d004 x7 : 205b5d3938373434 x6 : ffffffd8167397c8
[ 129.447610][ T934] x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffffffc0843db9e0
[ 129.447629][ T934] x2 : 0000000000002f15 x1 : 0000000000000000 x0 : 0000000000000000
[ 129.447647][ T934] Call trace:
[ 129.447655][ T934] android_rvh_schedule_bug+0x0/0x8 [sched_walt_debug 1400000003000000474e550080cce8a8a78606b6]
[ 129.447681][ T934] __might_resched+0x190/0x1a8
[ 129.447694][ T934] shrink_work+0x180/0x248
[ 129.447706][ T934] process_one_work+0x260/0x624
[ 129.447718][ T934] worker_thread+0x28c/0x454
[ 129.447729][ T934] kthread+0x118/0x158
[ 129.447742][ T934] ret_from_fork+0x10/0x20
[ 129.447761][ T934] Code: ???????? ???????? ???????? d2b5dd1f (d4210000)
[ 129.447772][ T934] ---[ end trace 0000000000000000 ]---
dm_bufio_lock will call spin_lock_bh when try_verify_in_tasklet
is enabled, and __scan will be called in atomic context.
Fixes: 7cd326747f46 ("dm bufio: remove dm_bufio_cond_resched()")
Signed-off-by: LongPing Wei <weilongping@oppo.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
---
drivers/md/dm-bufio.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
Index: linux-stable/drivers/md/dm-bufio.c
===================================================================
--- linux-stable.orig/drivers/md/dm-bufio.c
+++ linux-stable/drivers/md/dm-bufio.c
@@ -1685,7 +1685,8 @@ static void __scan(struct dm_bufio_clien
atomic_long_dec(&c->need_shrink);
freed++;
}
- cond_resched();
+ if (!(static_branch_unlikely(&no_sleep_enabled) && c->no_sleep))
+ cond_resched();
}
}
}
^ permalink raw reply [flat|nested] 2+ messages in thread
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2025-05-05 7:38 FAILED: patch "[PATCH] dm-bufio: don't schedule in atomic context" failed to apply to 6.1-stable tree gregkh
2025-05-05 9:20 ` [PATCH v6.1] dm-bufio: don't schedule in atomic context Mikulas Patocka
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