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Fri, 12 Dec 2025 15:57:21 +0000 (GMT) Message-ID: <2bb0437e-7610-4da9-86a0-a95e425bb79e@linux.ibm.com> Date: Fri, 12 Dec 2025 21:27:19 +0530 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V2] block: fix race between wbt_enable_default and IO submission To: Ming Lei , Jens Axboe , linux-block@vger.kernel.org Cc: Yu Kuai , Guangwu Zhang References: <20251212143500.485521-1-ming.lei@redhat.com> Content-Language: en-US From: Nilay Shroff In-Reply-To: <20251212143500.485521-1-ming.lei@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUxMjA2MDAyMCBTYWx0ZWRfX1IKX9axjjT1w 3dSs1cqMFKPBqAXmZTpimJ/vR3MPseDxHDhU+XkHDhtQzEiRq8jftoCzJVUIOBA+Shn3XafBgwB 9oaQPsHSu+JqFEJzYDu620mZPE2NklK/0eCeeB2mtezorYFL0rXeOg3RqN4tNUlHboi7GWtwdxC daN5Xt8M9/+hvIuonW3FQ7qmRr2UDNAba0++VTtGItpq2ydWbrUxiAZIR2zgJOWC2nIOzwr/edg f2zF1AZqlQ4OsJRTezZHZIr28JfSnmlXpoZWi4DiY8oC2E3gLjgQv2+XKPxJfBisohJU/rpVI2S sIslQGglWwLBnig0vapIadmQ2JPt88MH/3X6eH3/oT9VKc+njeczlTR7Xhpb+nU/JYQ/OZvNemQ R/2BMS3550iZT/6aKqIgHv96ec9tCA== X-Authority-Analysis: v=2.4 cv=S/DUAYsP c=1 sm=1 tr=0 ts=693c3b65 cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=IkcTkHD0fZMA:10 a=wP3pNCr1ah4A:10 a=VkNPw1HP01LnGYTKEx00:22 a=VnNF1IyMAAAA:8 a=jZooFtwnRqYpt7X2nncA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-ORIG-GUID: I1xnuS6oi-Y0tu4aLyoBgZ1O_XzRMWeU X-Proofpoint-GUID: I1xnuS6oi-Y0tu4aLyoBgZ1O_XzRMWeU X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.100.49 definitions=2025-12-12_04,2025-12-11_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 phishscore=0 clxscore=1015 impostorscore=0 suspectscore=0 lowpriorityscore=0 adultscore=0 spamscore=0 bulkscore=0 priorityscore=1501 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2510240000 definitions=main-2512060020 On 12/12/25 8:05 PM, Ming Lei wrote: > When wbt_enable_default() is moved out of queue freezing in elevator_change(), > it can cause the wbt inflight counter to become negative (-1), leading to hung > tasks in the writeback path. Tasks get stuck in wbt_wait() because the counter > is in an inconsistent state. Looks good to me: Reviewed-by: Nilay Shroff