zfs clone should not mount the clone if canmount == noauto

Creation of a new filesystem does not imply an intent to mount it.

Since canmount property is not inherited and its default value is 'on',
the only scenario where this matters is zfs clone -o canmount=noauto.
zfs create -o canmount=noauto already does not mount the new filesystem.

Also see:
https://www.illumos.org/issues/5984
https://reviews.csiden.org/r/228/
https://github.com/FransUrbo/zfs/commit/dd0e0e69f5b1c83bf2895ac00a0b83af77473175
https://github.com/zfsonlinux/zfs/issues/2241

Reviewed by:	mahrens
MFC after:	8 days
Sponsored by:	ClusterHQ

1 files changed, 30 insertions, 11 deletions

diff --git a/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c b/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c
index d7c702b9b567..389b248283d5 100644
--- a/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c
+++ b/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c
@@ -593,6 +593,17 @@ finish_progress(char *done)
 }
 
 /*
+ * Check if the dataset is mountable and should be automatically mounted.
+ */
+static boolean_t
+should_auto_mount(zfs_handle_t *zhp)
+{
+	if (!zfs_prop_valid_for_type(ZFS_PROP_CANMOUNT, zfs_get_type(zhp)))
+		return (B_FALSE);
+	return (zfs_prop_get_int(zhp, ZFS_PROP_CANMOUNT) == ZFS_CANMOUNT_ON);
+}
+
+/*
  * zfs clone [-p] [-o prop=value] ... <snap> <fs | vol>
  *
  * Given an existing dataset, create a writable copy whose initial contents
@@ -677,9 +688,22 @@ zfs_do_clone(int argc, char **argv)
 
 		clone = zfs_open(g_zfs, argv[1], ZFS_TYPE_DATASET);
 		if (clone != NULL) {
-			if (zfs_get_type(clone) != ZFS_TYPE_VOLUME)
-				if ((ret = zfs_mount(clone, NULL, 0)) == 0)
-					ret = zfs_share(clone);
+			/*
+			 * If the user doesn't want the dataset
+			 * automatically mounted, then skip the mount/share
+			 * step.
+			 */
+			if (should_auto_mount(clone)) {
+				if ((ret = zfs_mount(clone, NULL, 0)) != 0) {
+					(void) fprintf(stderr, gettext("clone "
+					    "successfully created, "
+					    "but not mounted\n"));
+				} else if ((ret = zfs_share(clone)) != 0) {
+					(void) fprintf(stderr, gettext("clone "
+					    "successfully created, "
+					    "but not shared\n"));
+				}
+			}
 			zfs_close(clone);
 		}
 	}
@@ -728,7 +752,6 @@ zfs_do_create(int argc, char **argv)
 	int ret = 1;
 	nvlist_t *props;
 	uint64_t intval;
-	int canmount = ZFS_CANMOUNT_OFF;
 
 	if (nvlist_alloc(&props, NV_UNIQUE_NAME, 0) != 0)
 		nomem();
@@ -868,19 +891,15 @@ zfs_do_create(int argc, char **argv)
 		goto error;
 
 	ret = 0;
-	/*
-	 * if the user doesn't want the dataset automatically mounted,
-	 * then skip the mount/share step
-	 */
-	if (zfs_prop_valid_for_type(ZFS_PROP_CANMOUNT, type))
-		canmount = zfs_prop_get_int(zhp, ZFS_PROP_CANMOUNT);
 
 	/*
 	 * Mount and/or share the new filesystem as appropriate.  We provide a
 	 * verbose error message to let the user know that their filesystem was
 	 * in fact created, even if we failed to mount or share it.
+	 * If the user doesn't want the dataset automatically mounted,
+	 * then skip the mount/share step altogether.
 	 */
-	if (!nomount && canmount == ZFS_CANMOUNT_ON) {
+	if (!nomount && should_auto_mount(zhp)) {
 		if (zfs_mount(zhp, NULL, 0) != 0) {
 			(void) fprintf(stderr, gettext("filesystem "
 			    "successfully created, but not mounted\n"));