dm: export name and uuid
This patch adds a function to obtain a copy of a mapped device's name and uuid.
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 6af95f9..138200b 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1515,3 +1515,35 @@
dm_hash_exit();
}
+
+/**
+ * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
+ * @md: Pointer to mapped_device
+ * @name: Buffer (size DM_NAME_LEN) for name
+ * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
+ */
+int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
+{
+ int r = 0;
+ struct hash_cell *hc;
+
+ if (!md)
+ return -ENXIO;
+
+ dm_get(md);
+ down_read(&_hash_lock);
+ hc = dm_get_mdptr(md);
+ if (!hc || hc->md != md) {
+ r = -ENXIO;
+ goto out;
+ }
+
+ strcpy(name, hc->name);
+ strcpy(uuid, hc->uuid ? : "");
+
+out:
+ up_read(&_hash_lock);
+ dm_put(md);
+
+ return r;
+}