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Wysocki" , Danilo Krummrich , Alexander Viro , Christian Brauner , Jan Kara , Ingo Molnar , Peter Zijlstra , Andrew Morton , Jens Axboe , driver-core@lists.linux.dev, autofs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, syzbot+002fb7b2d0bc53bf7e75@syzkaller.appspotmail.com Subject: Re: [PATCH 0/2] kernfs, autofs: fix pipe lock cycles through sysfs stores In-Reply-To: <7a212208-74f2-4d79-8ca2-a1502d0e0a1c@gmail.com> References: <6aa23178.f81106d8.2ab401.0006.GAE@google.com> <649966b83b39fcdd25e892fc3c6732a1@kernel.org> <22d41f2a5546d3bc90a1b3ad24ed3656588a854f.camel@themaw.net> <7a212208-74f2-4d79-8ca2-a1502d0e0a1c@gmail.com> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 96820140006 X-Stat-Signature: nfuuje3r4swzb6q39yeak7k5uu7hog39 X-Rspam-User: X-Spam-Status: No, score=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-HE-Tag: 1792780382-927476 X-HE-Meta: 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 gJgemPg/ ySET+mw9rEtZjUHpCmW1x1zlHa6rUFgc82Ia0ILlLoMfsTrYoZ+pT4TjWRuiieo6h4QWLFIVkAxcudxg2QdEoq/AYkBCYxGKyCKcTj4CI4QlT8clHgEE/femoss4RYL7O8z0fRrEAgbsNP0moVrgMO5aPYMRc3oksehOUPJMxQyTE2rn2W5fs1/yWYwmb4eUFIFUS8oQ0si1ljcMs5/zzlICl3jf7T0HJA1CknExdfVnBmXdfMVDwQaymMTu3ho3ftRjb7zp92R9AhdwZksIz/2I0yrZ/fkFjn/CKkX8ogkXS0XElcmrtofgLhcNzda3ZEQsGAYaaKsXxCXCXtgk1bDk8d76NOiYfjmKESd1o8sJdN3on0RwTgpqoVTRTKcgtfvvuGsJiQDwcAdY= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Hello, Krystian. On Fri, Oct 23, 2026 at 04:05:38PM +0200, Krystian Kaniewski wrote: > Given these two separate paths, did you intend to prevent only direct > splice operations on /sys/power/resume even though the reported class > cycle would remain, or should a replacement also eliminate the > lockdep report? The lockdep report should go away too. What about disabling splice only for the files whose ->store() can look up arbitrary paths, such as /sys/power/resume, and giving their of->mutex a separate lockdep class? Splice is what nests of->mutex inside pipe->mutex, so if those files can't be spliced, pipe->mutex never nests outside the new class and the cycle is gone. Commit 16b52bbee482 ("kernfs: annotate different lockdep class for of->mutex of writable files") did the same kind of split for writable files. Thanks. -- tejun