From nobody Sat Jan 8 04:29:36 2022 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 18368193230E; Sat, 8 Jan 2022 04:29:38 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4JW6Yr5xDDz3Dhm; Sat, 8 Jan 2022 04:29:36 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 984C018596; Sat, 8 Jan 2022 04:29:36 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 2084TaEc022345; Sat, 8 Jan 2022 04:29:36 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 2084Tasw022344; Sat, 8 Jan 2022 04:29:36 GMT (envelope-from git) Date: Sat, 8 Jan 2022 04:29:36 GMT Message-Id: <202201080429.2084Tasw022344@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Konstantin Belousov Subject: git: 4a4b059a9795 - main - Add vfs_remount_ro() List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kib X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 4a4b059a97950740f04b091d7050460a984e7555 Auto-Submitted: auto-generated ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1641616177; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=U53i2vPqfeKtEdS05nKd0UMdP5Z11m9PL7ShfLro8ZU=; b=UMt3NCDjEK+3ouRs/in8lq73VK2A5L8xzAt+bprd5e7K5Bs4ty58Cl0Mc+6V5oXvIWM23m yH9UWLHakk2TCHGkkY67/1lvM1fsTFuF8UTpAwYDq7ijAK2LCoqhPQhosA6zoZyhL+xBeB rHArYWtyd0s5nZtMtuwHg0OfFVe3CqC/8VOgSUAh3zt/TXnlRSlyaNjyOODvvxsuuxHRBP 2U9927/yTwlixVEdjlVoKGiUbvdSle9ohkh0g1OuXmjzCuBi48iGFFHo/rF11ro9O1SuzE cuMcVm3rbWDGxHRQs42sbVjxFPhSUAHAk0PBa1PtWadfTLN2B44rCXa6xldNhQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1641616177; a=rsa-sha256; cv=none; b=lMDoVNpR7oKT2/yQPmvRVQxf/NK+c0hxGXWA+fj4U7VCbrncUWF10AAw1P6zlFQdW43y8+ nvOgaphvrjYHQuiNUCEu0r9UjS3UkJ+aMToucDJg+SgDYSLHaC0yUgcSQvPKtP8U7Dsw0i gLb6XxK1lvwM9PCleGpU3wqwFmHacgB1ZTtoAJUiyvU2sGhPVb8ztP6qE71DRg24PuCyUn cE7PE/+UbwPZItWuQ2uHz9K9fHXHkZ8ZedFtubdnMkClHT8ebeAtyyHX79/2oq0vcsTDtg MxedD6HL6sD0xrd4kKZW6I2sifC0GJGc3BIxvxv9YqeE0MT6/bTbS9UvzYaA9w== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=4a4b059a97950740f04b091d7050460a984e7555 commit 4a4b059a97950740f04b091d7050460a984e7555 Author: Konstantin Belousov AuthorDate: 2021-12-25 19:44:59 +0000 Commit: Konstantin Belousov CommitDate: 2022-01-08 03:41:44 +0000 Add vfs_remount_ro() a helper to remount filesystem from rw to ro. Tested by: pho Reviewed by: markj, mckusick Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D33721 --- sys/kern/vfs_mount.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++ sys/sys/mount.h | 2 ++ 2 files changed, 91 insertions(+) diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c index ee163a5e8137..61c239cf65b3 100644 --- a/sys/kern/vfs_mount.c +++ b/sys/kern/vfs_mount.c @@ -2868,6 +2868,95 @@ mount_devctl_event(const char *type, struct mount *mp, bool donew) free(buf, M_MOUNT); } +/* + * Force remount specified mount point to read-only. The argument + * must be busied to avoid parallel unmount attempts. + * + * Intended use is to prevent further writes if some metadata + * inconsistency is detected. Note that the function still flushes + * all cached metadata and data for the mount point, which might be + * not always suitable. + */ +int +vfs_remount_ro(struct mount *mp) +{ + struct vfsoptlist *opts; + struct vfsopt *opt; + struct vnode *vp_covered, *rootvp; + int error; + + KASSERT(mp->mnt_lockref > 0, + ("vfs_remount_ro: mp %p is not busied", mp)); + KASSERT((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0, + ("vfs_remount_ro: mp %p is being unmounted (and busy?)", mp)); + + rootvp = NULL; + vp_covered = mp->mnt_vnodecovered; + error = vget(vp_covered, LK_EXCLUSIVE | LK_NOWAIT); + if (error != 0) + return (error); + VI_LOCK(vp_covered); + if ((vp_covered->v_iflag & VI_MOUNT) != 0) { + VI_UNLOCK(vp_covered); + vput(vp_covered); + return (EBUSY); + } + vp_covered->v_iflag |= VI_MOUNT; + VI_UNLOCK(vp_covered); + vfs_op_enter(mp); + vn_seqc_write_begin(vp_covered); + + MNT_ILOCK(mp); + if ((mp->mnt_flag & MNT_RDONLY) != 0) { + MNT_IUNLOCK(mp); + error = EBUSY; + goto out; + } + mp->mnt_flag |= MNT_UPDATE | MNT_FORCE | MNT_RDONLY; + rootvp = vfs_cache_root_clear(mp); + MNT_IUNLOCK(mp); + + opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK | M_ZERO); + TAILQ_INIT(opts); + opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK | M_ZERO); + opt->name = strdup("ro", M_MOUNT); + opt->value = NULL; + TAILQ_INSERT_TAIL(opts, opt, link); + vfs_mergeopts(opts, mp->mnt_opt); + mp->mnt_optnew = opts; + + error = VFS_MOUNT(mp); + + if (error == 0) { + MNT_ILOCK(mp); + mp->mnt_flag &= ~(MNT_UPDATE | MNT_FORCE); + MNT_IUNLOCK(mp); + vfs_deallocate_syncvnode(mp); + if (mp->mnt_opt != NULL) + vfs_freeopts(mp->mnt_opt); + mp->mnt_opt = mp->mnt_optnew; + } else { + MNT_ILOCK(mp); + mp->mnt_flag &= ~(MNT_UPDATE | MNT_FORCE | MNT_RDONLY); + MNT_IUNLOCK(mp); + vfs_freeopts(mp->mnt_optnew); + } + mp->mnt_optnew = NULL; + +out: + vfs_op_exit(mp); + VI_LOCK(vp_covered); + vp_covered->v_iflag &= ~VI_MOUNT; + VI_UNLOCK(vp_covered); + vput(vp_covered); + vn_seqc_write_end(vp_covered); + if (rootvp != NULL) { + vn_seqc_write_end(rootvp); + vrele(rootvp); + } + return (error); +} + /* * Suspend write operations on all local writeable filesystems. Does * full sync of them in the process. diff --git a/sys/sys/mount.h b/sys/sys/mount.h index 1b4243788f7b..ae3eebd94c53 100644 --- a/sys/sys/mount.h +++ b/sys/sys/mount.h @@ -1036,6 +1036,8 @@ void vfs_register_for_notification(struct mount *, struct mount *, void vfs_unregister_for_notification(struct mount *, struct mount_upper_node *); void vfs_unregister_upper(struct mount *, struct mount_upper_node *); +int vfs_remount_ro(struct mount *mp); + extern TAILQ_HEAD(mntlist, mount) mountlist; /* mounted filesystem list */ extern struct mtx_padalign mountlist_mtx; extern struct nfs_public nfs_pub;