commit b1078d4f14a8ea66d81ab1a4ac16df4be2732daa
Author: James Antill <james@and.org>
Date:   Thu Dec 6 16:58:26 2012 -0500

    Add an exported lvm_vg_create_lv_snapshot() API, to create snapshots LVs.

diff --git a/liblvm/lvm2app.h b/liblvm/lvm2app.h
index dd200e3..500f149 100644
--- a/liblvm/lvm2app.h
+++ b/liblvm/lvm2app.h
@@ -1002,6 +1002,32 @@ int lvm_vg_set_property(const vg_t vg, const char *name,
 lv_t lvm_vg_create_lv_linear(vg_t vg, const char *name, uint64_t size);
 
 /**
+ * Create a logical volume snapshot of another volume.
+ * This function commits the change to disk and does _not_ require calling
+ * lvm_vg_write().
+ * NOTE: The commit behavior of this function is subject to change
+ * as the API is developed.
+ *
+ * \param   vg
+ * VG handle obtained from lvm_vg_create() or lvm_vg_open().
+ *
+ * \param   origin
+ * Name of logical volume to create snapshot from.
+ *
+ * \param   name
+ * Name of logical volume to create.
+ *
+ * \param   size
+ * Size of logical volume in extents.
+ *
+ * \return
+ * non-NULL handle to an LV object created, or NULL if creation fails.
+ *
+ */
+lv_t lvm_vg_create_lv_snapshot(vg_t vg, const char *origin,
+                               const char *name, uint64_t size);
+
+/**
  * Return a list of lvseg handles for a given LV handle.
  *
  * \memberof lv_t
diff --git a/liblvm/lvm_lv.c b/liblvm/lvm_lv.c
index 336b714..6a394fd 100644
--- a/liblvm/lvm_lv.c
+++ b/liblvm/lvm_lv.c
@@ -166,6 +166,33 @@ lv_t lvm_vg_create_lv_linear(vg_t vg, const char *name, uint64_t size)
 	return (lv_t) lvl->lv;
 }
 
+lv_t lvm_vg_create_lv_snapshot(vg_t vg, const char *origin,
+                               const char *name, uint64_t size)
+{
+	struct lvcreate_params lp;
+	uint64_t extents;
+	struct lv_list *lvl;
+
+	if (vg_read_error(vg))
+		return NULL;
+	if (!vg_check_write_mode(vg))
+		return NULL;
+	memset(&lp, 0, sizeof(lp));
+	extents = extents_from_size(vg->cmd, size / SECTOR_SIZE,
+				    vg->extent_size);
+	_lv_set_default_params(&lp, vg, name, extents);
+	if (!_lv_set_default_linear_params(vg->cmd, &lp))
+		return_NULL;
+        lp.snapshot = 1;
+        lp.origin = origin;
+	if (!lv_create_single(vg, &lp))
+		return NULL;
+	lvl = find_lv_in_vg(vg, name);
+	if (!lvl)
+		return NULL;
+	return (lv_t) lvl->lv;
+}
+
 /*
  * FIXME: This function should probably not commit to disk but require calling
  * lvm_vg_write.