X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Fdmu_objset.c;h=1d0b4619fd0f20e612bf529cf8160bcbeae2825c;hb=1c5de20ae2511124613926e4f780572634818218;hp=0703a946687f399f455c0d48c702c929e93b6820;hpb=5d0265c0dd54d798a35babe587ad5138392fe807;p=zfs.git

diff --git a/module/zfs/dmu_objset.c b/module/zfs/dmu_objset.c
index 0703a94..1d0b461 100644
--- a/module/zfs/dmu_objset.c
+++ b/module/zfs/dmu_objset.c
@@ -1584,6 +1584,41 @@ dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
 	return (0);
 }
 
+/*
+ * Determine the objset id for a given snapshot name.
+ */
+int
+dmu_snapshot_id(objset_t *os, const char *snapname, uint64_t *idp)
+{
+	dsl_dataset_t *ds = os->os_dsl_dataset;
+	zap_cursor_t cursor;
+	zap_attribute_t attr;
+	int error;
+
+	if (ds->ds_phys->ds_snapnames_zapobj == 0)
+		return (ENOENT);
+
+	zap_cursor_init(&cursor, ds->ds_dir->dd_pool->dp_meta_objset,
+	    ds->ds_phys->ds_snapnames_zapobj);
+
+	error = zap_cursor_move_to_key(&cursor, snapname, MT_EXACT);
+	if (error) {
+		zap_cursor_fini(&cursor);
+		return (error);
+	}
+
+	error = zap_cursor_retrieve(&cursor, &attr);
+	if (error) {
+		zap_cursor_fini(&cursor);
+		return (error);
+	}
+
+	*idp = attr.za_first_integer;
+	zap_cursor_fini(&cursor);
+
+	return (0);
+}
+
 int
 dmu_dir_list_next(objset_t *os, int namelen, char *name,
     uint64_t *idp, uint64_t *offp)