[PATCH] afs: correctly use 64-bit time for UUID

[Arnd Bergmann]

From: Tina Ruchandani <ruchandani.tina@xxxxxxxxx>

UUID calculation uses 'struct timespec' whose seconds will overflow
in year 2038 and beyond for 32-bit systems. This patch removes the
dependency on 'struct timespec' by using ktime_get_real().
While the patch does not fix a 'bug' as such, it is part of a larger
effort to remove instances of 'struct timespec' and other data-structures
suffering from y2038 problem from the kernel.

Suggested-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Tina Ruchandani <ruchandani.tina@xxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 fs/afs/main.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/fs/afs/main.c b/fs/afs/main.c
index f8188feb03ad..59e7ef38e541 100644
--- a/fs/afs/main.c
+++ b/fs/afs/main.c
@@ -13,6 +13,7 @@
 #include <linux/moduleparam.h>
 #include <linux/init.h>
 #include <linux/completion.h>
+#include <linux/ktime.h>
 #include <linux/sched.h>
 #include <linux/random.h>
 #define CREATE_TRACE_POINTS
@@ -39,7 +40,6 @@ struct workqueue_struct *afs_wq;
  */
 static int __init afs_get_client_UUID(void)
 {
-	struct timespec ts;
 	u64 uuidtime;
 	u16 clockseq;
 	int ret;
@@ -50,9 +50,7 @@ static int __init afs_get_client_UUID(void)
 	if (ret < 0)
 		return ret;
 
-	getnstimeofday(&ts);
-	uuidtime = (u64) ts.tv_sec * 1000 * 1000 * 10;
-	uuidtime += ts.tv_nsec / 100;
+	uuidtime = ktime_divns(ktime_get_real(), 100);
 	uuidtime += AFS_UUID_TO_UNIX_TIME;
 	afs_uuid.time_low = uuidtime;
 	afs_uuid.time_mid = uuidtime >> 32;
-- 
2.9.0