Add a little helper to make /sys/dev/block/major:minor paths

2017-11-30 12:59:23 +01:00
parent ee3467c6bd
commit 553e15f21b
4 changed files with 34 additions and 46 deletions
@@ -23,5 +23,13 @@
 #include <stddef.h>
 #include <sys/types.h>

+#include "macro.h"
+#include "stdio-util.h"
+
 int encode_devnode_name(const char *str, char *str_enc, size_t len);
 int whitelisted_char_for_devnode(char c, const char *additional);
+
+#define SYS_BLOCK_PATH_MAX(suffix)                                      \
+        (strlen("/sys/dev/block/") + DECIMAL_STR_MAX(dev_t) + 1 + DECIMAL_STR_MAX(dev_t) + strlen_ptr(suffix))
+#define xsprintf_sys_block_path(buf, suffix, devno)                     \
+        xsprintf(buf, "/sys/dev/block/%u:%u%s", major(devno), minor(devno), strempty(suffix))