MFV r254421:

Illumos ZFS issues:
  3996 want a libzfs_core API to rollback to latest snapshot

3 files changed, 29 insertions, 12 deletions

diff --git a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
index 7186c6f..e330ad2 100644
--- a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
+++ b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
@@ -3572,7 +3572,6 @@ zfs_rollback(zfs_handle_t *zhp, zfs_handle_t *snap, boolean_t force)
 {
 	rollback_data_t cb = { 0 };
 	int err;
-	zfs_cmd_t zc = { 0 };
 	boolean_t restore_resv = 0;
 	uint64_t old_volsize, new_volsize;
 	zfs_prop_t resv_prop;
@@ -3604,22 +3603,15 @@ zfs_rollback(zfs_handle_t *zhp, zfs_handle_t *snap, boolean_t force)
 		    (old_volsize == zfs_prop_get_int(zhp, resv_prop));
 	}
 
-	(void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
-
-	if (ZFS_IS_VOLUME(zhp))
-		zc.zc_objset_type = DMU_OST_ZVOL;
-	else
-		zc.zc_objset_type = DMU_OST_ZFS;
-
 	/*
 	 * We rely on zfs_iter_children() to verify that there are no
 	 * newer snapshots for the given dataset.  Therefore, we can
 	 * simply pass the name on to the ioctl() call.  There is still
 	 * an unlikely race condition where the user has taken a
 	 * snapshot since we verified that this was the most recent.
-	 *
 	 */
-	if ((err = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_ROLLBACK, &zc)) != 0) {
+	err = lzc_rollback(zhp->zfs_name, NULL, 0);
+	if (err != 0) {
 		(void) zfs_standard_error_fmt(zhp->zfs_hdl, errno,
 		    dgettext(TEXT_DOMAIN, "cannot rollback '%s'"),
 		    zhp->zfs_name);
diff --git a/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.c b/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.c
index c5c3b0e..6f4b46c 100644
--- a/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.c
+++ b/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.c
@@ -20,7 +20,7 @@
  */
 
 /*
- * Copyright (c) 2012 by Delphix. All rights reserved.
+ * Copyright (c) 2013 by Delphix. All rights reserved.
  * Copyright (c) 2013 Steven Hartland. All rights reserved.
  */
 
@@ -628,3 +628,27 @@ out:
 	free((void*)(uintptr_t)zc.zc_nvlist_dst);
 	return (error);
 }
+
+/*
+ * Roll back this filesystem or volume to its most recent snapshot.
+ * If snapnamebuf is not NULL, it will be filled in with the name
+ * of the most recent snapshot.
+ *
+ * Return 0 on success or an errno on failure.
+ */
+int
+lzc_rollback(const char *fsname, char *snapnamebuf, int snapnamelen)
+{
+	nvlist_t *args;
+	nvlist_t *result;
+	int err;
+
+	args = fnvlist_alloc();
+	err = lzc_ioctl(ZFS_IOC_ROLLBACK, fsname, args, &result);
+	nvlist_free(args);
+	if (err == 0 && snapnamebuf != NULL) {
+		const char *snapname = fnvlist_lookup_string(result, "target");
+		(void) strlcpy(snapnamebuf, snapname, snapnamelen);
+	}
+	return (err);
+}
diff --git a/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.h b/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.h
index b10098b..c55caf4 100644
--- a/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.h
+++ b/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.h
@@ -20,7 +20,7 @@
  */
 
 /*
- * Copyright (c) 2012 by Delphix. All rights reserved.
+ * Copyright (c) 2013 by Delphix. All rights reserved.
  * Copyright (c) 2013 by Martin Matuska <mm@FreeBSD.org>. All rights reserved.
  */
 
@@ -59,6 +59,7 @@ int lzc_send_space(const char *snapname, const char *fromsnap,
 
 boolean_t lzc_exists(const char *dataset);
 
+int lzc_rollback(const char *fsname, char *snapnamebuf, int snapnamelen);
 
 #ifdef	__cplusplus
 }