From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by sourceware.org (Postfix) with ESMTP id 665E738618EB for ; Tue, 13 Oct 2020 15:59:13 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 665E738618EB Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-267-B-HLlZ3kOwa7bCjQQepjpw-1; Tue, 13 Oct 2020 11:59:11 -0400 X-MC-Unique: B-HLlZ3kOwa7bCjQQepjpw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 00F8B101963C; Tue, 13 Oct 2020 15:59:10 +0000 (UTC) Received: from oldenburg2.str.redhat.com (ovpn-114-237.ams2.redhat.com [10.36.114.237]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CEA326EF7C; Tue, 13 Oct 2020 15:59:08 +0000 (UTC) From: Florian Weimer To: Adhemerval Zanella via Libc-alpha Cc: Adhemerval Zanella , James Clarke , John Paul Adrian Glaubitz Subject: Re: [PATCH v2 4/9] linux: Use getdents64 on non-LFS readdir References: <20201002170620.1611673-1-adhemerval.zanella@linaro.org> <20201002170620.1611673-5-adhemerval.zanella@linaro.org> Date: Tue, 13 Oct 2020 17:59:06 +0200 In-Reply-To: <20201002170620.1611673-5-adhemerval.zanella@linaro.org> (Adhemerval Zanella via Libc-alpha's message of "Fri, 2 Oct 2020 14:06:15 -0300") Message-ID: <87d01mrub9.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-6.4 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Oct 2020 15:59:14 -0000 * Adhemerval Zanella via Libc-alpha: > It reserves some space on the allocated internal buffer to be > used as a the returned dirent struct. The kernel obtained dirent64 > struct are copied to the temporary buffer on each readdir call. > > The overflow test is moved once the dirent64 entry is copied > to the temporary buffer, and a subsequent readdir will obtain the > next entry. The idea is an overflow fails to return the entry on > readdir, but a next readdir might still obtain the next entry. > (for filesystem that does not have the concept of sequential d_off, > such as ext4). Can you make the translation buffer a separate allocation? Then you can resize it to accommodate long names. Thanks, Florian -- Red Hat GmbH, https://de.redhat.com/ , Registered seat: Grasbrunn, Commercial register: Amtsgericht Muenchen, HRB 153243, Managing Directors: Charles Cachera, Brian Klemm, Laurie Krebs, Michael O'Neill