From patchwork Tue Jan 19 01:49:54 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 8057661 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id A480FBEEE5 for ; Tue, 19 Jan 2016 01:50:58 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 926A620411 for ; Tue, 19 Jan 2016 01:50:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 71600203FB for ; Tue, 19 Jan 2016 01:50:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757034AbcASBux (ORCPT ); Mon, 18 Jan 2016 20:50:53 -0500 Received: from cn.fujitsu.com ([59.151.112.132]:29715 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1756982AbcASBuX (ORCPT ); Mon, 18 Jan 2016 20:50:23 -0500 X-IronPort-AV: E=Sophos;i="5.20,346,1444665600"; d="scan'208";a="2721282" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 19 Jan 2016 09:50:22 +0800 Received: from G08CNEXCHPEKD02.g08.fujitsu.local (unknown [10.167.33.83]) by cn.fujitsu.com (Postfix) with ESMTP id B1BB341896D6 for ; Tue, 19 Jan 2016 09:50:02 +0800 (CST) Received: from localhost.localdomain (10.167.226.34) by G08CNEXCHPEKD02.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.181.6; Tue, 19 Jan 2016 09:50:01 +0800 From: Qu Wenruo To: Subject: [PATCH V6 2/3] btrfs: Introduce new mount option to disable tree log replay Date: Tue, 19 Jan 2016 09:49:54 +0800 Message-ID: <1453168195-18518-3-git-send-email-quwenruo@cn.fujitsu.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1453168195-18518-1-git-send-email-quwenruo@cn.fujitsu.com> References: <1453168195-18518-1-git-send-email-quwenruo@cn.fujitsu.com> MIME-Version: 1.0 X-Originating-IP: [10.167.226.34] X-yoursite-MailScanner-ID: B1BB341896D6.AE20B X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: quwenruo@cn.fujitsu.com X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Introduce a new mount option "nologreplay" to co-operate with "ro" mount option to get real readonly mount, like "norecovery" in ext* and xfs. Since the new parse_options() need to check new flags at remount time, so add a new parameter for parse_options(). Signed-off-by: Qu Wenruo Reviewed-by: Chandan Rajendra Tested-by: Austin S. Hemmelgarn --- v2: Make RO check mandatory for btrfs_parse_options(). Add btrfs_show_options() support for nologreplay. Document for btrfs-mount(5) will follow after the patch being merged. v3: Apply the document suggestion from Chandan Rajendra. v4: Add 'norecovery' alias for 'nologreplay'. v5: None v6: Splite alias for "norecovery" into another patch. --- Documentation/filesystems/btrfs.txt | 8 ++++++++ fs/btrfs/ctree.h | 4 +++- fs/btrfs/disk-io.c | 7 ++++--- fs/btrfs/super.c | 28 +++++++++++++++++++++++++--- 4 files changed, 40 insertions(+), 7 deletions(-) diff --git a/Documentation/filesystems/btrfs.txt b/Documentation/filesystems/btrfs.txt index 8e22d92..34ea3ed 100644 --- a/Documentation/filesystems/btrfs.txt +++ b/Documentation/filesystems/btrfs.txt @@ -168,6 +168,14 @@ Options with (*) are default options and will not show in the mount options. notreelog Enable/disable the tree logging used for fsync and O_SYNC writes. + nologreplay + Disable the log tree replay at mount time to prevent filesystem + from getting modified. + Must be used with 'ro' mount option. + A filesystem mounted with this option cannot transition to a + read-write mount via remount,rw - the filesystem must be unmounted + and mounted back again if read-write access is desired. + usebackuproot Enable attempts to use backup tree roots if a bad tree root is found at mount time. diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 47a96a7..7ef9b2a 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2250,6 +2250,7 @@ struct btrfs_ioctl_defrag_range_args { #define BTRFS_MOUNT_FRAGMENT_DATA (1 << 24) #define BTRFS_MOUNT_FRAGMENT_METADATA (1 << 25) #define BTRFS_MOUNT_FREE_SPACE_TREE (1 << 26) +#define BTRFS_MOUNT_NOLOGREPLAY (1 << 27) #define BTRFS_DEFAULT_COMMIT_INTERVAL (30) #define BTRFS_DEFAULT_MAX_INLINE (8192) @@ -4144,7 +4145,8 @@ void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info); ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size); /* super.c */ -int btrfs_parse_options(struct btrfs_root *root, char *options); +int btrfs_parse_options(struct btrfs_root *root, char *options, + unsigned long new_flags); int btrfs_sync_fs(struct super_block *sb, int wait); #ifdef CONFIG_PRINTK diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 6f16557..0ec4199 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2726,7 +2726,7 @@ int open_ctree(struct super_block *sb, */ fs_info->compress_type = BTRFS_COMPRESS_ZLIB; - ret = btrfs_parse_options(tree_root, options); + ret = btrfs_parse_options(tree_root, options, sb->s_flags); if (ret) { err = ret; goto fail_alloc; @@ -3024,8 +3024,9 @@ retry_root_backup: if (ret) goto fail_trans_kthread; - /* do not make disk changes in broken FS */ - if (btrfs_super_log_root(disk_super) != 0) { + /* do not make disk changes in broken FS or nologreplay is given */ + if (btrfs_super_log_root(disk_super) != 0 && + !btrfs_test_opt(tree_root, NOLOGREPLAY)) { ret = btrfs_replay_log(fs_info, fs_devices); if (ret) { err = ret; diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 0842456..1f97aa1 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -304,6 +304,7 @@ enum { Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard, Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow, Opt_datasum, Opt_treelog, Opt_noinode_cache, Opt_usebackuproot, + Opt_nologreplay, #ifdef CONFIG_BTRFS_DEBUG Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all, #endif @@ -335,6 +336,7 @@ static const match_table_t tokens = { {Opt_noacl, "noacl"}, {Opt_notreelog, "notreelog"}, {Opt_treelog, "treelog"}, + {Opt_nologreplay, "nologreplay"}, {Opt_flushoncommit, "flushoncommit"}, {Opt_noflushoncommit, "noflushoncommit"}, {Opt_ratio, "metadata_ratio=%d"}, @@ -374,7 +376,8 @@ static const match_table_t tokens = { * reading in a new superblock is parsed here. * XXX JDM: This needs to be cleaned up for remount. */ -int btrfs_parse_options(struct btrfs_root *root, char *options) +int btrfs_parse_options(struct btrfs_root *root, char *options, + unsigned long new_flags) { struct btrfs_fs_info *info = root->fs_info; substring_t args[MAX_OPT_ARGS]; @@ -391,8 +394,12 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) else if (cache_gen) btrfs_set_opt(info->mount_opt, SPACE_CACHE); + /* + * Even the options are empty, we still need to do extra check + * against new flags + */ if (!options) - goto out; + goto check; /* * strsep changes the string, duplicate it because parse_options @@ -592,6 +599,10 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) btrfs_clear_and_info(root, NOTREELOG, "enabling tree log"); break; + case Opt_nologreplay: + btrfs_set_and_info(root, NOLOGREPLAY, + "disabling log replay at mount time"); + break; case Opt_flushoncommit: btrfs_set_and_info(root, FLUSHONCOMMIT, "turning on flush-on-commit"); @@ -782,6 +793,15 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) break; } } +check: + /* + * Extra check for current option against current flag + */ + if (btrfs_test_opt(root, NOLOGREPLAY) && !(new_flags & MS_RDONLY)) { + btrfs_err(root->fs_info, + "nologreplay must be used with ro mount option"); + ret = -EINVAL; + } out: if (btrfs_fs_compat_ro(root->fs_info, FREE_SPACE_TREE) && !btrfs_test_opt(root, FREE_SPACE_TREE) && @@ -1192,6 +1212,8 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) seq_puts(seq, ",ssd"); if (btrfs_test_opt(root, NOTREELOG)) seq_puts(seq, ",notreelog"); + if (btrfs_test_opt(root, NOLOGREPLAY)) + seq_puts(seq, ",nologreplay"); if (btrfs_test_opt(root, FLUSHONCOMMIT)) seq_puts(seq, ",flushoncommit"); if (btrfs_test_opt(root, DISCARD)) @@ -1677,7 +1699,7 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data) } } - ret = btrfs_parse_options(root, data); + ret = btrfs_parse_options(root, data, *flags); if (ret) { ret = -EINVAL; goto restore;