From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A55BE2144CC; Wed, 7 May 2025 18:50:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746643819; cv=none; b=TJr47O6C0pefO1jXOk31nBt4IZ2mj19iCyaZByg+NqZAw+h6eIFWI101fgFch36CMRNoP0QS+6SWqUVuvAsK8jaexkKmc+JCxguM/1jseIl1n9AuLOiFAecJH+06wZkpbq0hpHftgguluqXEuhaz9XfoSRH3/nUAUKUmNOVbPfo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746643819; c=relaxed/simple; bh=7OOsDm62cv6J/yiy5JDqHORikm3vxrKJZE3owrIlANk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rBrAVBS4tsVCWf7DD7TAiqDtN8xw5+8oR+tnzy5Yp7vxQcs4rCSy3pIWFfN8zPgB1b2dFJaXn8hMxZIoFn2A+A4wJ9JAzRdZOg84s1h5RDCnK+O8C0w5Ax8NyKyOpvYMJByfzvcVXNpp9iBXOtrTOScWsuRkxUKIYmOl7WdsAJc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KVeXEv9J; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="KVeXEv9J" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 21150C4CEEB; Wed, 7 May 2025 18:50:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1746643819; bh=7OOsDm62cv6J/yiy5JDqHORikm3vxrKJZE3owrIlANk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KVeXEv9JamiN9dU9pSgaSGS/16E/m6xr2NEtDFQxl7GrfcETShCqrPe+faeEeY/NE QG4NAPlYKuHJRHzqoNfjfxWw4ZSSJsEIWVCMKYDXxu/hnN/eQl5sLq95oyUWCt0xyP ugJXnVodHUZAtN+o2+EeHPjtka5ZwAiBQveZJTZc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, LongPing Wei , Mikulas Patocka Subject: [PATCH 6.14 028/183] dm-bufio: dont schedule in atomic context Date: Wed, 7 May 2025 20:37:53 +0200 Message-ID: <20250507183825.823305814@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250507183824.682671926@linuxfoundation.org> References: <20250507183824.682671926@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: LongPing Wei commit a3d8f0a7f5e8b193db509c7191fefeed3533fc44 upstream. 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] [] 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 Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-bufio.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- 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 + /*--------------------------------------------------------------*/ /* @@ -2426,7 +2428,12 @@ static void __scan(struct dm_bufio_clien 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); + } } } }