From patchwork Tue Dec 15 07:09:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Feng X-Patchwork-Id: 11974129 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5F0BC4361B for ; Tue, 15 Dec 2020 07:10:57 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0C9182078B for ; Tue, 15 Dec 2020 07:10:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0C9182078B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=smartx.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:57794 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kp4U3-0008LK-N1 for qemu-devel@archiver.kernel.org; Tue, 15 Dec 2020 02:10:55 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:54914) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kp4SV-0007ik-1a for qemu-devel@nongnu.org; Tue, 15 Dec 2020 02:09:19 -0500 Received: from mail-pg1-x541.google.com ([2607:f8b0:4864:20::541]:36982) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kp4SS-0004qS-1o for qemu-devel@nongnu.org; Tue, 15 Dec 2020 02:09:18 -0500 Received: by mail-pg1-x541.google.com with SMTP id c12so14140769pgm.4 for ; Mon, 14 Dec 2020 23:09:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=smartx-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id; bh=Y3YpWoxnSryB8CjXGBpQCGG0yPrRQcYr04aKhX2Gn60=; b=Ttm3lkq8u18+qmFVtH7TYT8KrkiOgGUxvYrpNr+Hvi0/f6KFDJLx9e/I9SI5UYi7QO RQtVJZqsXF4Vj380iwW6WU8oShsTIxiqHErJyqJN6SO2iO3fcOSbw/15IZIG9oMSzf/D s8IjjGeWxI3uAVXptXSjEYwckp9ROrdB4Vy7XxovtSw71H/jW3EUmC6VP+bYAFWEGqNK 9rFTfZdrTwEQTDrVrkUf9iDfz21zl6xTJW9Yyj783l0wHI0J/oEpn9EWK4JGAOLRSRL5 ePuY5iFr0/ByBQpZ1ElR1T3L4nlbHnnKissICs8PHaUccAnpQVoNR1hb2m1VI+hZ1vTI /0Dg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=Y3YpWoxnSryB8CjXGBpQCGG0yPrRQcYr04aKhX2Gn60=; b=r0sq0livXJE1SA33pT6A8t5azY1gOOMvRfbMvTVDTJXj9wZYcAXbinxyzHKzDTDIBE 46IVqnkUcBAd+tJPp4/EjbOMOnJ4/65LoXINCaRlw/LXK7p6yryWH2sAwUg7D92MIAnf l771zUcXKhft45b08obNywTJPAtaUX+nAavTO2ZVZVl01t+ITKO5j9EdWkHkNrQysBUj ml0EU9+AcX4kMB8OJ/QkK4Id3kVa+DemDCtI6/z4tpQ7hDRdzPzHAU8tLfZn6zbarMfw zt4Mo58g1wulakK69SVS3T+FsLHj21dAiVO0vj1w4dJnqWNX2kAgC9tn8qXXCZuKd76K asOQ== X-Gm-Message-State: AOAM5308cB7bhHxSoIIPHpvSC1Uf9+Osc6ms0gFI0588c0YNCIcO4Ztx Y04UsqK9gO/eCEty4v9TYutCDw== X-Google-Smtp-Source: ABdhPJxz8pu0BZcFvyiurnr7QHlzo2fiO4Y4Byv/dUypCRAexm4cRD6LF9JNp9IZDABB3pAzryLn2w== X-Received: by 2002:a63:e246:: with SMTP id y6mr17213592pgj.412.1608016153679; Mon, 14 Dec 2020 23:09:13 -0800 (PST) Received: from 64-217.abest.vip ([129.227.156.197]) by smtp.gmail.com with ESMTPSA id r68sm22628105pfr.113.2020.12.14.23.09.11 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 14 Dec 2020 23:09:13 -0800 (PST) From: Li Feng To: berrange@redhat.com, Kevin Wolf , Max Reitz , qemu-block@nongnu.org (open list:raw), qemu-devel@nongnu.org (open list:All patches CC here) Subject: [PATCH v4] file-posix: detect the lock using the real file Date: Tue, 15 Dec 2020 15:09:28 +0800 Message-Id: <1608016169-5639-1-git-send-email-fengli@smartx.com> X-Mailer: git-send-email 1.8.3.1 Received-SPF: none client-ip=2607:f8b0:4864:20::541; envelope-from=fengli@smartx.com; helo=mail-pg1-x541.google.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lifeng1519@gmail.com, Li Feng , kyle@smartx.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This patch addresses this issue: When accessing a volume on an NFS filesystem without supporting the file lock, tools, like qemu-img, will complain "Failed to lock byte 100". In the original code, the qemu_has_ofd_lock will test the lock on the "/dev/null" pseudo-file. Actually, the file.locking is per-drive property, which depends on the underlay filesystem. In this patch, add a new 'qemu_has_file_lock' to detect whether the file supports the file lock. And disable the lock when the underlay file system doesn't support locks. Signed-off-by: Li Feng --- v4: use the fd as the qemu_has_file_lock argument. v3: don't call the qemu_has_ofd_lock, use a new function instead. v2: remove the refactoring. --- block/file-posix.c | 66 +++++++++++++++++++++++++------------------- include/qemu/osdep.h | 1 + util/osdep.c | 19 +++++++++++++ 3 files changed, 58 insertions(+), 28 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index 806764f7e3..9708212f01 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -584,6 +584,21 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, s->use_linux_io_uring = (aio == BLOCKDEV_AIO_OPTIONS_IO_URING); #endif + s->open_flags = open_flags; + raw_parse_flags(bdrv_flags, &s->open_flags, false); + + s->fd = -1; + fd = qemu_open(filename, s->open_flags, errp); + ret = fd < 0 ? -errno : 0; + + if (ret < 0) { + if (ret == -EROFS) { + ret = -EACCES; + } + goto fail; + } + s->fd = fd; + locking = qapi_enum_parse(&OnOffAuto_lookup, qemu_opt_get(opts, "locking"), ON_OFF_AUTO_AUTO, &local_err); @@ -607,6 +622,13 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, break; case ON_OFF_AUTO_AUTO: s->use_lock = qemu_has_ofd_lock(); + if (s->use_lock && !qemu_has_file_lock(s->fd)) { + /* + * When the os supports the OFD lock, but the filesystem doesn't + * support, just disable the file lock. + */ + s->use_lock = false; + } break; default: abort(); @@ -625,22 +647,6 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, s->drop_cache = qemu_opt_get_bool(opts, "drop-cache", true); s->check_cache_dropped = qemu_opt_get_bool(opts, "x-check-cache-dropped", false); - - s->open_flags = open_flags; - raw_parse_flags(bdrv_flags, &s->open_flags, false); - - s->fd = -1; - fd = qemu_open(filename, s->open_flags, errp); - ret = fd < 0 ? -errno : 0; - - if (ret < 0) { - if (ret == -EROFS) { - ret = -EACCES; - } - goto fail; - } - s->fd = fd; - /* Check s->open_flags rather than bdrv_flags due to auto-read-only */ if (s->open_flags & O_RDWR) { ret = check_hdev_writable(s->fd); @@ -2388,6 +2394,7 @@ raw_co_create(BlockdevCreateOptions *options, Error **errp) int fd; uint64_t perm, shared; int result = 0; + bool use_lock; /* Validate options and set default values */ assert(options->driver == BLOCKDEV_DRIVER_FILE); @@ -2428,19 +2435,22 @@ raw_co_create(BlockdevCreateOptions *options, Error **errp) perm = BLK_PERM_WRITE | BLK_PERM_RESIZE; shared = BLK_PERM_ALL & ~BLK_PERM_RESIZE; - /* Step one: Take locks */ - result = raw_apply_lock_bytes(NULL, fd, perm, ~shared, false, errp); - if (result < 0) { - goto out_close; - } + use_lock = qemu_has_file_lock(fd); + if (use_lock) { + /* Step one: Take locks */ + result = raw_apply_lock_bytes(NULL, fd, perm, ~shared, false, errp); + if (result < 0) { + goto out_close; + } - /* Step two: Check that nobody else has taken conflicting locks */ - result = raw_check_lock_bytes(fd, perm, shared, errp); - if (result < 0) { - error_append_hint(errp, - "Is another process using the image [%s]?\n", - file_opts->filename); - goto out_unlock; + /* Step two: Check that nobody else has taken conflicting locks */ + result = raw_check_lock_bytes(fd, perm, shared, errp); + if (result < 0) { + error_append_hint(errp, + "Is another process using the image [%s]?\n", + file_opts->filename); + goto out_unlock; + } } /* Clear the file by truncating it to 0 */ diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index f9ec8c84e9..c7587be99d 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -513,6 +513,7 @@ int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive); int qemu_unlock_fd(int fd, int64_t start, int64_t len); int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive); bool qemu_has_ofd_lock(void); +bool qemu_has_file_lock(int fd); #endif #if defined(__HAIKU__) && defined(__i386__) diff --git a/util/osdep.c b/util/osdep.c index 66d01b9160..07de97e2c5 100644 --- a/util/osdep.c +++ b/util/osdep.c @@ -225,6 +225,25 @@ static void qemu_probe_lock_ops(void) } } +bool qemu_has_file_lock(int fd) +{ +#ifdef F_OFD_SETLK + int cmd = F_OFD_GETLK; +#else + int cmd = F_GETLK; +#endif + int ret; + struct flock fl = { + .l_whence = SEEK_SET, + .l_start = 0, + .l_len = 0, + .l_type = F_WRLCK, + }; + + ret = fcntl(fd, cmd, &fl); + return ret == 0; +} + bool qemu_has_ofd_lock(void) { qemu_probe_lock_ops();