lib/uuid.c: introduce a few more generic helpers

There are new helpers in this patch:

  uuid_is_valid		checks if a UUID is valid
  uuid_be_to_bin	converts from string to binary (big endian)
  uuid_le_to_bin	converts from string to binary (little endian)

They will be used in future, i.e. in the following patches in the series.

This also moves the indices arrays to lib/uuid.c to be shared accross
modules.

[andriy.shevchenko@linux.intel.com: fix typo]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 5 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index be0e7cf..0967771 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -30,6 +30,7 @@
 #include <linux/ioport.h>
 #include <linux/dcache.h>
 #include <linux/cred.h>
+#include <linux/uuid.h>
 #include <net/addrconf.h>
 #ifdef CONFIG_BLOCK
 #include <linux/blkdev.h>
@@ -1304,19 +1305,17 @@ static noinline_for_stack
 char *uuid_string(char *buf, char *end, const u8 *addr,
 		  struct printf_spec spec, const char *fmt)
 {
-	char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
+	char uuid[UUID_STRING_LEN + 1];
 	char *p = uuid;
 	int i;
-	static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
-	static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
-	const u8 *index = be;
+	const u8 *index = uuid_be_index;
 	bool uc = false;
 
 	switch (*(++fmt)) {
 	case 'L':
 		uc = true;		/* fall-through */
 	case 'l':
-		index = le;
+		index = uuid_le_index;
 		break;
 	case 'B':
 		uc = true;