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authorBrian Behlendorf <[email protected]>2011-03-15 09:34:56 -0700
committerBrian Behlendorf <[email protected]>2011-03-15 13:33:29 -0700
commit093aa692861d0c91fd29979c13fc188760a3985b (patch)
treef8a3e7abede409592f871ad7ab776bbdb13a7436 /cmd/mount_zfs
parent04516a45b27144cf42bec005ef2de6d505d236a5 (diff)
Always allow '-o remount,ro'
Allow the mount(8) utility to always operate on all datasets when remounting them read-only. This critical for rc.sysinit/umountroot which remounts the root filesystem read-only during shutdown to ensure everything is correctly flushed to disk. Fix minor typo, the check to set zfsutil should use the bitwise '&'. I must have accidentally hit the adjacent '*' and obviously neither the compiler or my code review caught this. Fix it now.
Diffstat (limited to 'cmd/mount_zfs')
-rw-r--r--cmd/mount_zfs/mount_zfs.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/cmd/mount_zfs/mount_zfs.c b/cmd/mount_zfs/mount_zfs.c
index fbb954acd..52e5992d7 100644
--- a/cmd/mount_zfs/mount_zfs.c
+++ b/cmd/mount_zfs/mount_zfs.c
@@ -298,7 +298,7 @@ main(int argc, char **argv)
char mntopts[MNT_LINE_MAX] = { '\0' };
char badopt[MNT_LINE_MAX] = { '\0' };
char *dataset, *mntpoint;
- unsigned long mntflags = 0, zfsflags = 0;
+ unsigned long mntflags = 0, zfsflags = 0, remount_ro = 0;
int sloppy = 0, fake = 0, verbose = 0, nomtab = 0, zfsutil = 0;
int error, c;
@@ -402,7 +402,10 @@ main(int argc, char **argv)
if (mntflags & MS_REMOUNT)
nomtab = 1;
- if (zfsflags * ZS_ZFSUTIL)
+ if ((mntflags & MS_REMOUNT) && (mntflags & MS_RDONLY))
+ remount_ro = 1;
+
+ if (zfsflags & ZS_ZFSUTIL)
zfsutil = 1;
if ((g_zfs = libzfs_init()) == NULL)
@@ -427,6 +430,10 @@ main(int argc, char **argv)
* 'zfs mount'. However, since 'zfs mount' actually invokes 'mount'
* 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.
*/
if (zfsutil && !strcmp(legacy, ZFS_MOUNTPOINT_LEGACY)) {
(void) fprintf(stderr, gettext(
@@ -437,7 +444,7 @@ main(int argc, char **argv)
return (MOUNT_USAGE);
}
- if (!zfsutil && strcmp(legacy, ZFS_MOUNTPOINT_LEGACY)) {
+ if (!zfsutil && strcmp(legacy, ZFS_MOUNTPOINT_LEGACY) && !remount_ro) {
(void) fprintf(stderr, gettext(
"filesystem '%s' cannot be mounted using 'mount'.\n"
"Use 'zfs set mountpoint=%s' or 'zfs mount %s'.\n"