ubirmvol: Implement -N switch for ubirmvol

function                                             old     new   delta
get_volid_by_name                                      -     125    +125
ubi_devnum_from_devname                                -      43     +43
ubi_tools_main                                      1215    1220      +5
packed_usage                                       30674   30655     -19
ubirename_main                                       394     221    -173
------------------------------------------------------------------------------
(add/remove: 3/0 grow/shrink: 1/2 up/down: 173/-192)          Total: -19 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/libbb/ubi.c b/libbb/ubi.c
new file mode 100644
index 000000000..7d3b2952d
--- /dev/null
+++ b/libbb/ubi.c
@@ -0,0 +1,43 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * Copyright (C) 2016 Denys Vlasenko
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
+ */
+//kbuild:lib-y += ubi.o
+
+#include "libbb.h"
+
+// from ubi-media.h
+#define UBI_MAX_VOLUME_NAME 127
+#define UBI_MAX_VOLUMES     128
+
+unsigned FAST_FUNC ubi_devnum_from_devname(const char *str)
+{
+        unsigned ubi_devnum;
+
+        if (sscanf(str, "/dev/ubi%u", &ubi_devnum) != 1)
+                bb_error_msg_and_die("not an UBI device: '%s'", str);
+	return ubi_devnum;
+}
+
+int FAST_FUNC get_volid_by_name(unsigned ubi_devnum, const char *vol_name)
+{
+	unsigned i;
+
+	for (i = 0; i < UBI_MAX_VOLUMES; i++) {
+		char buf[UBI_MAX_VOLUME_NAME + 1];
+		char fname[sizeof("/sys/class/ubi/ubi%u_%u/name") + 2 * sizeof(int)*3];
+
+		sprintf(fname, "/sys/class/ubi/ubi%u_%u/name", ubi_devnum, i);
+		if (open_read_close(fname, buf, sizeof(buf)) <= 0)
+			continue;
+
+		strchrnul(buf, '\n')[0] = '\0';
+		if (strcmp(vol_name, buf) == 0)
+			return i;
+	}
+	bb_error_msg_and_die("volume '%s' not found", vol_name);
+}