mdadm: introduce sysfs_get_container_devnm()

[thirdparty/mdadm.git] / sysfs.c

diff --git a/sysfs.c b/sysfs.c
index f95ef7013e845b62791f499acd08d5f0abe315fd..230b842e41171191ed58f015571b78fccadff03c 100644 (file)
--- a/sysfs.c
+++ b/sysfs.c
@@ -74,6 +74,29 @@ void sysfs_free(struct mdinfo *sra)
        }
 }
 
+/**
+ * sysfs_get_container_devnm() - extract container device name.
+ * @mdi: md_info describes member array, with GET_VERSION option.
+ * @buf: buf to fill, must be MD_NAME_MAX.
+ *
+ * External array version is in format {/,-}<container_devnm>/<array_index>
+ * Extract container_devnm from it and safe it in @buf.
+ */
+void sysfs_get_container_devnm(struct mdinfo *mdi, char *buf)
+{
+       char *p;
+
+       assert(is_subarray(mdi->text_version));
+
+       /* Skip first special sign */
+       snprintf(buf, MD_NAME_MAX, "%s", mdi->text_version + 1);
+
+       /* Remove array index */
+       p = strchr(buf, '/');
+       if (p)
+               *p = 0;
+}
+
 int sysfs_open(char *devnm, char *devname, char *attr)
 {
        char fname[MAX_SYSFS_PATH_LEN];