From owner-svn-src-head@freebsd.org Tue Sep 12 06:04:02 2017 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6158DE1AB95; Tue, 12 Sep 2017 06:04:02 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 2AADB38C3; Tue, 12 Sep 2017 06:04:02 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v8C641lM052578; Tue, 12 Sep 2017 06:04:01 GMT (envelope-from avg@FreeBSD.org) Received: (from avg@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id v8C641MV052577; Tue, 12 Sep 2017 06:04:01 GMT (envelope-from avg@FreeBSD.org) Message-Id: <201709120604.v8C641MV052577@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: avg set sender to avg@FreeBSD.org using -f From: Andriy Gapon Date: Tue, 12 Sep 2017 06:04:01 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r323480 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs X-SVN-Group: head X-SVN-Commit-Author: avg X-SVN-Commit-Paths: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs X-SVN-Commit-Revision: 323480 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Sep 2017 06:04:02 -0000 Author: avg Date: Tue Sep 12 06:04:01 2017 New Revision: 323480 URL: https://svnweb.freebsd.org/changeset/base/323480 Log: zfs_get_vfs: reference a requested filesystem instead of vfs_busy-ing it The only consumer of zfs_get_vfs, zfs_unmount_snap, does not need the filesystem to be busy, it just need a reference that it can pass to dounmount. Also, previously the code was racy as it unbusied the filesystem before taking a reference on it. Now the code should be simpler and safer. MFC after: 2 weeks Sponsored by: Panzura Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c Tue Sep 12 06:02:21 2017 (r323479) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c Tue Sep 12 06:04:01 2017 (r323480) @@ -3049,13 +3049,11 @@ zfs_get_vfs(const char *resource) mtx_lock(&mountlist_mtx); TAILQ_FOREACH(vfsp, &mountlist, mnt_list) { if (strcmp(refstr_value(vfsp->vfs_resource), resource) == 0) { - if (vfs_busy(vfsp, MBF_MNTLSTLOCK) != 0) - vfsp = NULL; + vfs_ref(vfsp); break; } } - if (vfsp == NULL) - mtx_unlock(&mountlist_mtx); + mtx_unlock(&mountlist_mtx); return (vfsp); } @@ -3545,7 +3543,9 @@ zfs_unmount_snap(const char *snapname) { vfs_t *vfsp; zfsvfs_t *zfsvfs; +#ifdef illumos int err; +#endif if (strchr(snapname, '@') == NULL) return (0); @@ -3557,23 +3557,19 @@ zfs_unmount_snap(const char *snapname) zfsvfs = vfsp->vfs_data; ASSERT(!dsl_pool_config_held(dmu_objset_pool(zfsvfs->z_os))); - err = vn_vfswlock(vfsp->vfs_vnodecovered); #ifdef illumos + err = vn_vfswlock(vfsp->vfs_vnodecovered); VFS_RELE(vfsp); -#else - vfs_unbusy(vfsp); -#endif if (err != 0) return (SET_ERROR(err)); +#endif /* * Always force the unmount for snapshots. */ - #ifdef illumos (void) dounmount(vfsp, MS_FORCE, kcred); #else - vfs_ref(vfsp); (void) dounmount(vfsp, MS_FORCE, curthread); #endif return (0);