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Tue, 3 Jun 2025 20:58:04 -0400 (EDT) Message-ID: Date: Wed, 4 Jun 2025 01:58:03 +0100 Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH bpf-next 3/4] bpf: Introduce path iterator To: Song Liu , Al Viro Cc: Jan Kara , bpf@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, kernel-team@meta.com, andrii@kernel.org, eddyz87@gmail.com, ast@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, brauner@kernel.org, kpsingh@kernel.org, mattbobrowski@google.com, amir73il@gmail.com, repnop@google.com, jlayton@kernel.org, josef@toxicpanda.com, mic@digikod.net, gnoack@google.com References: <20250529173810.GJ2023217@ZenIV> <20250529183536.GL2023217@ZenIV> <20250529201551.GN2023217@ZenIV> <20250529214544.GO2023217@ZenIV> <20250529231018.GP2023217@ZenIV> Content-Language: en-US From: Tingmao Wang In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 5/30/25 01:42, Song Liu wrote: > [...] > On Thu, May 29, 2025 at 4:10 PM Al Viro wrote: >> >> Note, BTW, that it might be better off by doing that similar to >> d_path.c - without arseloads of dget_parent/dput et.al.; not sure >> how feasible it is, but if everything in it can be done under >> rcu_read_lock(), that's something to look into. > > I don't think we can do everything here inside rcu_read_lock(). > But d_path.c does have some code we can probably reuse or > learn from. Note that I've made an RFC patch for this as I've also been looking into this a bit earlier: https://lore.kernel.org/all/cover.1748997840.git.m@maowtm.org/ I've CC'd some people here but not all, in the interest of not spamming like 20 people, but feedback from all is welcome. Mine is also its own separate patch that shouldn't block Song's patch here, and I can rebase it on top of (v2 or a later version of) this series once this is merged.