From c171ea71bbedde9c30c39ce96d555bfd585e49a2 Mon Sep 17 00:00:00 2001 From: Brian Behlendorf Date: Mon, 30 Jul 2012 15:38:02 -0700 Subject: [PATCH] Allow '-o remount' for non-legacy datasets This is done for compatibility with existing Linux infrastructure. In particular, when using zfs as a root filesystem there are init scripts which as part of shutdown remount root read-only. Also, the new systemd infrastructure being used by Fedora expects to be able to remount a file system read-write. Signed-off-by: Brian Behlendorf Issue #847 --- cmd/mount_zfs/mount_zfs.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/cmd/mount_zfs/mount_zfs.c b/cmd/mount_zfs/mount_zfs.c index 45c291e04..0a69d69d7 100644 --- a/cmd/mount_zfs/mount_zfs.c +++ b/cmd/mount_zfs/mount_zfs.c @@ -312,7 +312,7 @@ main(int argc, char **argv) char badopt[MNT_LINE_MAX] = { '\0' }; char mtabopt[MNT_LINE_MAX] = { '\0' }; char *dataset, *mntpoint; - unsigned long mntflags = 0, zfsflags = 0, remount_ro = 0; + unsigned long mntflags = 0, zfsflags = 0, remount = 0; int sloppy = 0, fake = 0, verbose = 0, nomtab = 0, zfsutil = 0; int error, c; @@ -417,11 +417,10 @@ main(int argc, char **argv) " mountopts: \"%s\"\n mtabopts: \"%s\"\n"), dataset, mntpoint, mntflags, zfsflags, mntopts, mtabopt); - if (mntflags & MS_REMOUNT) + if (mntflags & MS_REMOUNT) { nomtab = 1; - - if ((mntflags & MS_REMOUNT) && (mntflags & MS_RDONLY)) - remount_ro = 1; + remount = 1; + } if (zfsflags & ZS_ZFSUTIL) zfsutil = 1; @@ -454,9 +453,10 @@ main(int argc, char **argv) * we differentiate the two cases using the 'zfsutil' mount option. * This mount option should only be supplied by the 'zfs mount' util. * - * The only exception to the above rule is '-o remount,ro'. This is - * always allowed for non-legacy datasets for rc.sysinit/umountroot - * to safely remount the root filesystem and flush its cache. + * The only exception to the above rule is '-o remount' which is + * always allowed for non-legacy datasets. This is done because when + * using zfs as your root file system both rc.sysinit/umountroot and + * systemd depend on 'mount -o remount ' to work. */ if (zfsutil && !strcmp(legacy, ZFS_MOUNTPOINT_LEGACY)) { (void) fprintf(stderr, gettext( @@ -467,7 +467,7 @@ main(int argc, char **argv) return (MOUNT_USAGE); } - if (!zfsutil && strcmp(legacy, ZFS_MOUNTPOINT_LEGACY) && !remount_ro) { + if (!zfsutil && strcmp(legacy, ZFS_MOUNTPOINT_LEGACY) && !remount) { (void) fprintf(stderr, gettext( "filesystem '%s' cannot be mounted using 'mount'.\n" "Use 'zfs set mountpoint=%s' or 'zfs mount %s'.\n"