[alternate PATCH] block: fix UUID string buffer length

[Joe Perches <joe@perches.com>]

The UUID string buffer is several bytes shorter than what is actually
required.  Fix it and remove the used once inline part_unpack_uuid,
use snprintf and printf extension %pU directly.

Based-on-a-patch-by: Rabin Vincent <rabin@rab.in>
cc: Will Drewry <wad@chromium.org>
Signed-off-by: Joe Perches <joe@perches.com>
---
 block/genhd.c         |    8 +++++---
 include/linux/genhd.h |    6 ------
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index e2f6790..427c955 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -735,7 +735,7 @@ void __init printk_all_partitions(void)
 		struct hd_struct *part;
 		char name_buf[BDEVNAME_SIZE];
 		char devt_buf[BDEVT_SIZE];
-		u8 uuid[PARTITION_META_INFO_UUIDLTH * 2 + 1];
+		char uuid[sizeof("12345678-1234-1234-1234-123456789012")];
 
 		/*
 		 * Don't show empty devices or things that have been
@@ -754,9 +754,11 @@ void __init printk_all_partitions(void)
 		while ((part = disk_part_iter_next(&piter))) {
 			bool is_part0 = part == &disk->part0;
 
-			uuid[0] = 0;
 			if (part->info)
-				part_unpack_uuid(part->info->uuid, uuid);
+				snprintf(uuid, sizeof(uuid),
+					 "%pU", part->info->uuid);
+			else
+				uuid[0] = '\0';
 
 			printk("%s%s %10llu %s %s", is_part0 ? "" : "  ",
 			       bdevt_str(part_devt(part), devt_buf),
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 02fa469..28bd275 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -221,12 +221,6 @@ static inline void part_pack_uuid(const u8 *uuid_str, u8 *to)
 	}
 }
 
-static inline char *part_unpack_uuid(const u8 *uuid, char *out)
-{
-	sprintf(out, "%pU", uuid);
-	return out;
-}
-
 static inline int disk_max_parts(struct gendisk *disk)
 {
 	if (disk->flags & GENHD_FL_EXT_DEVT)