From patchwork Wed Nov 3 05:00:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Venky Shankar X-Patchwork-Id: 12600083 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7E7D1C433F5 for ; Wed, 3 Nov 2021 05:00:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4ADAD6112E for ; Wed, 3 Nov 2021 05:00:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230046AbhKCFDZ (ORCPT ); Wed, 3 Nov 2021 01:03:25 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:24979 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229650AbhKCFDY (ORCPT ); Wed, 3 Nov 2021 01:03:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635915648; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=2MpeJ1k4uMGheSmYLGEXMQuo14p8TpUevnqWhZgURN4=; b=hZb6sc09ppgqj0SnFZ0rnA4CtKALh0cI1FbNlRK02+5ejiFkBIsEtJ7I/lXZMuTrZ+LDqy KIkPjEl4TWb3wO4fbuxEVfKwR5xfvNZ78JlymVGB1eHjK4Tvo0PIP3FKPw1PAP4LBJxCZi mMPzc/Dc1iWrXjW3yuGic5SzSq33b+o= Received: from mail-pg1-f197.google.com (mail-pg1-f197.google.com [209.85.215.197]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-282-mEUMT2IzNSOFdB-mDotUBw-1; Wed, 03 Nov 2021 01:00:46 -0400 X-MC-Unique: mEUMT2IzNSOFdB-mDotUBw-1 Received: by mail-pg1-f197.google.com with SMTP id x14-20020a63cc0e000000b002a5bc462947so892789pgf.20 for ; Tue, 02 Nov 2021 22:00:46 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=2MpeJ1k4uMGheSmYLGEXMQuo14p8TpUevnqWhZgURN4=; b=CLwdYzWSWycns5/oTUMNg/GzlB22Zli2Tw5TdM0M1gtIwLbqU4VCPV5AM1Z2K0FgN3 KUg05YfRDtR2DBfJTPw79Z9btkC8ZtbQOLktpmcSbwuPItTY4CuL0IopFYgkVSZA4ZCG 079mwwbcKqb5kotU390tO9PQhsZLrWEwCX214PYF9gfOXojNNSincZ52RwT1sZuYFG/i hPujRUcRthA9bJMy/dn71vUnJPdz/cvafamsJP24PJm8SbwEK9iNtzqBk4J6A7MZRBt5 EJS5o6lAj/lzjHgWN9ZLn+3vKjB+7Bw7iG78wYevmC6aLLSMuAgZjz1eLLIGQfo10IEt MXpg== X-Gm-Message-State: AOAM530bqROOyUJRvDjsyirst+Y1PkSNBM70vdpPunsWUFe+ikPREfT7 NJGlxHGYokl9qTX+WCV/iEIz3Ec083WHfMG5HM6r2+KqrednCBMAZg8uMmCiGYLUjQFN/uQbJ1f PWH7Md1jCaHSj2g+5vs96pA== X-Received: by 2002:a17:90b:3509:: with SMTP id ls9mr12125741pjb.99.1635915645825; Tue, 02 Nov 2021 22:00:45 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwF5pMFExDxRdxDmE8TDzhArwZXx+Yt/1tpcz6rwpD2o/hHW7pWRakuIFuLL5Y1mk4PoG8WCQ== X-Received: by 2002:a17:90b:3509:: with SMTP id ls9mr12125713pjb.99.1635915645570; Tue, 02 Nov 2021 22:00:45 -0700 (PDT) Received: from h3ckers-pride.redhat.com ([49.207.207.105]) by smtp.gmail.com with ESMTPSA id h6sm780636pfi.174.2021.11.02.22.00.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 Nov 2021 22:00:44 -0700 (PDT) From: Venky Shankar To: jlayton@redhat.com, pdonnell@redhat.com, idryomov@gmail.com Cc: ceph-devel@vger.kernel.org, Venky Shankar Subject: [PATCH v5 0/1] ceph: add sysfs entries signifying new mount syntax support Date: Wed, 3 Nov 2021 10:30:38 +0530 Message-Id: <20211103050039.371277-1-vshankar@redhat.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org v5: - switch to sysfs instead of debugfs [This is based on top of new mount syntax series] Patrick/Ilya proposed the idea of having sysfs entries to signify if kernel supports the new (v2) mount syntax. The primary use of this information is to catch any bugs in the new syntax implementation. This would be done as follows:: The userspace mount helper tries to mount using the new mount syntax and fallsback to using old syntax if the mount using new syntax fails. However, a bug in the new mount syntax implementation can silently result in the mount helper switching to old syntax. So, the sysfs entries can be relied upon by the mount helper to check if the kernel supports the new mount syntax. Cases when the mount using the new syntax fails, but the kernel does support the new mount syntax, the mount helper could probably log before switching to the old syntax (or fail the mount altogether when run in test mode). sysfs entries are as follows:: /sys/module/ceph/parameters/ .... .... /sys/module/ceph/parameters/mount_syntax_v2 /sys/module/ceph/parameters/mount_syntax_v1 .... .... Venky Shankar (1): ceph: mount syntax module parameter fs/ceph/super.c | 8 ++++++++ 1 file changed, 8 insertions(+)