From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi1-x234.google.com (mail-oi1-x234.google.com [IPv6:2607:f8b0:4864:20::234]) by sourceware.org (Postfix) with ESMTPS id 38DD13858025 for ; Thu, 10 Aug 2023 12:50:10 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 38DD13858025 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-oi1-x234.google.com with SMTP id 5614622812f47-3a7ca8720a0so661735b6e.2 for ; Thu, 10 Aug 2023 05:50:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1691671809; x=1692276609; h=content-transfer-encoding:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=ODQbhAidz1l5sWuRD6r27e6jU0LTFPTnnsivfOYmnGs=; b=l2P14EMypsbsEILD8m9iVplx7fytZvnBGGE2Ioce4kTUaODd50jUisCJR7UkgWfXqM a8OyulivMGXPC5w+9/zz9D49k9kfjGvHOamt7wD1s+6eoNDawWA6AIv6MNTPzHUCQoHi ftAaDAEstIKCV9a37tnBcnNpqVTySMgeLGtbzKPcINs5uQW2m/CeLTWRPanjymFE4UIC q+U5qwuZNXaTwAPorYSdTupp0Vs0eb4+SY0/gmyRdWMpsaW4bleBjEIldh47HzM4kVzh cGIJKsSe8FL5G0Exwp/tLVZMPDNWH1O2P7er17QYOYxEXn8g6U9H+iIUguKqNQxiJMfL JQGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691671809; x=1692276609; h=content-transfer-encoding:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ODQbhAidz1l5sWuRD6r27e6jU0LTFPTnnsivfOYmnGs=; b=XU5QjD2F+IBy6pbDEBiarvVMvmRRtLwi8bYS6W6BHyilkmV3O7p9g1vT1KkDBpMmOg nbNM7ZGzNQaQ6M1UwnzH8B0nX0H4+8EOrdp0n4Nw46M63diJhaa3+g53vOdMR+CiQqEC 6+O4joS15X0gu/chGkmbHtpaIVIKI6c1OVv1TG8rjoclgJwRNxse1lum6jqqNeioAA/z rREyfFsOZe46apN710C0DP51YUY3SqzgBma7BC5H9z5VvKC/EPYeRwD+MPEMjoVRo3Da VjuBZWTzAVbvwodLilabus+D+m6Lf4WexnrYdtIbJxIgosB1KVz4jfhPh5np+SYIFU4o PLyg== X-Gm-Message-State: AOJu0YzAwCg/bYeDDBwaR/TcyrqMHm3XdQC72mEBl/QEUBEaNotw+JiN 7OjlxapnGg/UO48kOwkmpQpB3xbDqlX5G719dRddyzld X-Google-Smtp-Source: AGHT+IEpxmLnvKfma7fxyca05HMejoTfTc8B6xZvZmBWIAO1JaYtJmGnfZedrQ11dMqH5nmO0BATlKL2zNcdYzlcAM4= X-Received: by 2002:a05:6808:1416:b0:3a7:d857:c5a3 with SMTP id w22-20020a056808141600b003a7d857c5a3mr655464oiv.20.1691671809294; Thu, 10 Aug 2023 05:50:09 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Martin Wege Date: Thu, 10 Aug 2023 14:49:58 +0200 Message-ID: Subject: Re: mkfifo: cannot set permissions of 'x.fifo': Not a directory To: cygwin@cygwin.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=0.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Wed, Aug 9, 2023 at 11:56=E2=80=AFAM Corinna Vinschen wrote: > > On Aug 9 11:12, Martin Wege via Cygwin wrote: > > On Wed, Aug 9, 2023 at 10:01=E2=80=AFAM Corinna Vinschen > > wrote: > > > > > > On Aug 8 21:38, Martin Wege via Cygwin wrote: > > > > On Tue, Aug 8, 2023 at 10:20=E2=80=AFAM Corinna Vinschen > > > > wrote: > > > > > > > > > > On Aug 7 23:14, Martin Wege via Cygwin wrote: > > > > > > Secondly, how are fifos, other device nodes and mknod implement= ed? You > > > > > > encode them as softlinks on ntfs? > > > > > > > > > > Not only on NTFS. FIFOs on the disk are always created as symlin= ks > > > > > with a special target string, recognized by Cygwin. No differece= on > > > > > NFS. Microsoft NFSv3 has no way to specify creating a "real" FIF= O > > > > > on the remote filesystem. It wouldn't make sense anyway, because > > > > > there's no way to share the FIFO across systems. > > > > > > > > So no Windows ioctl to do a mknod? > > > > > > Windows does not have provisions to store FIFOs on disk. The closest > > > you get in Windows are Windows named pipes, and those are stored > > > non-permanently in a special, temporary filesystem inside the native = NT > > > namespace. Try this in Cygwin: > > > > > > $ cd /proc/sys/Device/NamedPipe/ <-- trailing slash! > > > $ ls -l > > > > > > FIFOs in the normal Windows filesystem are a Cygwin fake. > > > > Maybe make pipes in Cygwin symlinks to /proc/sys/Device/NamedPipe/? > > Why? Windows Named Pipes don't act like UNIX FIFOs. OK, dumb-user-question: Where is the difference? > > > > > What does a Linux/FreeBSD FIFO file look like, if you export that > > > > filesystem via NFSv3, and mount it via the native Windows NFSv3 > > > > driver, and do a ls -l in Cygwin? > > > > > > It looks like a FIFO because MSFT NFSv3 exports the stat(2) info > > > verbatim: > > > > > > linux$ mkfifo blubb > > > > > > cygwin$ ls -l blubb > > > prw-r--r-- 1 corinna vinschen 0 Aug 8 10:22 blubb > > > > Will cygwin treat this as a FIFO? > > No. Cygwin FIFOs !=3D Unix FIFOs. > > > Can cygwin set the 'p' flag via a magic ioctl? > > No. I don't understand your insistence to use FIFOs on NFS. There is > no value in that, because you can't share them between systems anyway. > > https://www.unix.com/unix-for-advanced-and-expert-users/10861-fifo-over-n= fs.html > https://stackoverflow.com/questions/1038788/cant-write-to-fifo-file-moute= d-via-nfs I'm aware of that. But think about clusters of machines, or similar setups where many machines from different architectures share one NFS filesystem, and cooperatively work on that. So for example a master machine sets up everything for the build client machines, including generating FIFOs, which shall be used locally on the client. But then... oopsie, client cannot use the FIFO prepared by the cluster master, because it doesn't create the FIFO mknod nodes the same way as other platforms. Most of the concerns are about portability. Thanks, Martin