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Mon, 09 Mar 2026 13:40:14 -0400 X-MC-Unique: SeSodcbfN0qfZMZbKtY2IA-1 X-Mimecast-MFC-AGG-ID: SeSodcbfN0qfZMZbKtY2IA_1773078008 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C0E351956095; Mon, 9 Mar 2026 17:40:06 +0000 (UTC) Received: from fweimer-oldenburg.csb.redhat.com (unknown [10.2.16.175]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6997918001FE; Mon, 9 Mar 2026 17:39:55 +0000 (UTC) From: Florian Weimer To: Andy Lutomirski Cc: Christian Brauner , Jeff Layton , Dorjoy Chowdhury , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, ceph-devel@vger.kernel.org, gfs2@lists.linux.dev, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, v9fs@lists.linux.dev, linux-kselftest@vger.kernel.org, viro@zeniv.linux.org.uk, jack@suse.cz, chuck.lever@oracle.com, alex.aring@gmail.com, arnd@arndb.de, adilger@dilger.ca, mjguzik@gmail.com, smfrench@gmail.com, richard.henderson@linaro.org, mattst88@gmail.com, linmag7@gmail.com, tsbogend@alpha.franken.de, James.Bottomley@hansenpartnership.com, deller@gmx.de, davem@davemloft.net, andreas@gaisler.com, idryomov@gmail.com, amarkuze@redhat.com, slava@dubeyko.com, agruenba@redhat.com, trondmy@kernel.org, anna@kernel.org, sfrench@samba.org, pc@manguebit.org, ronniesahlberg@gmail.com, sprasad@microsoft.com, tom@talpey.com, bharathsm@microsoft.com, shuah@kernel.org, miklos@szeredi.hu, hansg@kernel.org Subject: Re: [PATCH v5 1/4] openat2: new OPENAT2_REGULAR flag support In-Reply-To: (Andy Lutomirski's message of "Mon, 9 Mar 2026 09:50:18 -0700") References: <20260307140726.70219-1-dorjoychy111@gmail.com> <20260307140726.70219-2-dorjoychy111@gmail.com> <801cf2c42b80d486726ea0a3774e52abcb158100.camel@kernel.org> <20260309-umsturz-herfallen-067eb2df7ec2@brauner> Date: Mon, 09 Mar 2026 18:39:53 +0100 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 * Andy Lutomirski: > On the flip side, /proc itself can certainly be opened. Should > O_REGULAR be able to open the more magical /proc and /sys files? Are > there any that are problematic? It seems reading from /proc/kmsg is destructive. The file doesn't have an end, either. It's more like a character device. Apparently, /sys/kernel/tracing/trace_pipe is similar in that regard. Maybe that's sufficient reason for blocking access? Although the side effect does not happen on open. The other issue is the incorrect size reporting in stat, which affects most (all?) files under /proc and /sys. Userspace has already to around that, though. Thanks, Florian