Turn the content of uuid_t into a union and add the fields for the v1
interpretation to it.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: David Howells <dhowells@xxxxxxxxxx>
---
include/linux/uuid.h | 59 ++++++++++++++++++++++++++++------------------------
1 file changed, 32 insertions(+), 27 deletions(-)
diff --git a/include/linux/uuid.h b/include/linux/uuid.h
index 0410cd002282..8bd1da4ec95d 100644
--- a/include/linux/uuid.h
+++ b/include/linux/uuid.h
@@ -18,40 +18,45 @@
#include <uapi/linux/uuid.h>
-typedef struct {
- __u8 b[16];
-} uuid_t;
-
-#define UUID(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7) \
-((uuid_t) \
-{{ ((a) >> 24) & 0xff, ((a) >> 16) & 0xff, ((a) >> 8) & 0xff, (a) & 0xff, \
- ((b) >> 8) & 0xff, (b) & 0xff, \
- ((c) >> 8) & 0xff, (c) & 0xff, \
- (d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7) }})
-
-/*
- * V1 (time-based) UUID definition [RFC 4122].
- * - the timestamp is a 60-bit value, split 32/16/12, and goes in 100ns
- * increments since midnight 15th October 1582
- * - add AFS_UUID_TO_UNIX_TIME to convert unix time in 100ns units to UUID
- * time
- * - the clock sequence is a 14-bit counter to avoid duplicate times
- */
-struct uuid_v1 {
- __be32 time_low; /* low part of timestamp */
- __be16 time_mid; /* mid part of timestamp */
- __be16 time_hi_and_version; /* high part of timestamp and version */
+/* v1 UUID defintions: */
#define UUID_TO_UNIX_TIME 0x01b21dd213814000ULL
#define UUID_TIMEHI_MASK 0x0fff
#define UUID_VERSION_TIME 0x1000 /* time-based UUID */
#define UUID_VERSION_NAME 0x3000 /* name-based UUID */
#define UUID_VERSION_RANDOM 0x4000 /* (pseudo-)random generated UUID */
- u8 clock_seq_hi_and_reserved; /* clock seq hi and variant */
#define UUID_CLOCKHI_MASK 0x3f
#define UUID_VARIANT_STD 0x80
- u8 clock_seq_low; /* clock seq low */
- u8 node[6]; /* spatially unique node ID (MAC addr) */
-};
+
+typedef struct {
+ union {
+ __u8 b[16];
+
+ /*
+ * V1 (time-based) UUID definition [RFC 4122]:
+ * - the timestamp is a 60-bit value, split 32/16/12, and goes
+ * in 100ns increments since midnight 15th October 1582
+ * - add UUID_TO_UNIX_TIME to convert unix time in 100ns
+ * units to UUID time
+ * - the clock sequence is a 14-bit counter to avoid duplicate
+ * times
+ */
+ struct uuid_v1 {
+ __be32 time_low;
+ __be16 time_mid;
+ __be16 time_hi_and_version;
+ u8 clock_seq_hi_and_reserved;
+ u8 clock_seq_low;
+ u8 node[6];
+ } v1;
+ };
+} uuid_t;
+
+#define UUID(a, _b, c, d0, d1, d2, d3, d4, d5, d6, d7) \
+{.b = { \
+ ((a) >> 24) & 0xff, ((a) >> 16) & 0xff, ((a) >> 8) & 0xff, (a) & 0xff, \
+ ((_b) >> 8) & 0xff, (_b) & 0xff, \
+ ((c) >> 8) & 0xff, (c) & 0xff, \
+ (d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7) }}
/*
* The length of a UUID string ("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee")
--
2.11.0
