3 files changed, 33 insertions, 1 deletions
diff --git a/usr/src/lib/libzfs/common/libzfs.h b/usr/src/lib/libzfs/common/libzfs.h
index 3df4e5ccaa..d4200f270e 100644
--- a/usr/src/lib/libzfs/common/libzfs.h
+++ b/usr/src/lib/libzfs/common/libzfs.h
@@ -581,9 +581,10 @@ extern int zpool_in_use(libzfs_handle_t *, int, pool_state_t *, char **,
     boolean_t *);
 
 /*
- * ftyp special.  Read the label from a given device.
+ * Label manipulation.
  */
 extern int zpool_read_label(int, nvlist_t **);
+extern int zpool_clear_label(int);
 
 /* is this zvol valid for use as a dump device? */
 extern int zvol_check_dump_config(char *);
diff --git a/usr/src/lib/libzfs/common/libzfs_import.c b/usr/src/lib/libzfs/common/libzfs_import.c
index f5793390ea..8705361b6c 100644
--- a/usr/src/lib/libzfs/common/libzfs_import.c
+++ b/usr/src/lib/libzfs/common/libzfs_import.c
@@ -898,6 +898,36 @@ zpool_read_label(int fd, nvlist_t **config)
 }
 
 /*
+ * Given a file descriptor, clear (zero) the label information.  This function
+ * is currently only used in the appliance stack as part of the ZFS sysevent
+ * module.
+ */
+int
+zpool_clear_label(int fd)
+{
+	struct stat64 statbuf;
+	int l;
+	vdev_label_t *label;
+	uint64_t size;
+
+	if (fstat64(fd, &statbuf) == -1)
+		return (0);
+	size = P2ALIGN_TYPED(statbuf.st_size, sizeof (vdev_label_t), uint64_t);
+
+	if ((label = calloc(sizeof (vdev_label_t), 1)) == NULL)
+		return (-1);
+
+	for (l = 0; l < VDEV_LABELS; l++) {
+		if (pwrite64(fd, label, sizeof (vdev_label_t),
+		    label_offset(size, l)) != sizeof (vdev_label_t))
+			return (-1);
+	}
+
+	free(label);
+	return (0);
+}
+
+/*
  * Given a list of directories to search, find all pools stored on disk.  This
  * includes partial pools which are not available to import.  If no args are
  * given (argc is 0), then the default directory (/dev/dsk) is searched.
diff --git a/usr/src/lib/libzfs/common/mapfile-vers b/usr/src/lib/libzfs/common/mapfile-vers
index 17a07d40a9..72b2b3da69 100644
--- a/usr/src/lib/libzfs/common/mapfile-vers
+++ b/usr/src/lib/libzfs/common/mapfile-vers
@@ -151,6 +151,7 @@ SUNWprivate_1.1 {
 	zfs_userquota_prop_prefixes;
 	zpool_add;
 	zpool_clear;
+	zpool_clear_label;
 	zpool_close;
 	zpool_create;
 	zpool_destroy;