From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 25 Oct 2016 01:58:26 +0000 (-0400)
Subject: LU-4423 libcfs: use 64-bit times for cfs_srand seed
X-Git-Tag: 2.9.52~68
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=2d1be90507fc1f42f565d9e672c634b3855cb978

LU-4423 libcfs: use 64-bit times for cfs_srand seed

Several functions in Lustre call cfs_srand with do_gettimeofday
as the seed to get a pseudo-random number.
There is no bug here, but changing it to use ktime_get_ts64()
gets us closer to deprecating do_gettimeofday() and makes it slightly
more random.

Affected functions are:
lnet_shuffle_seed, init_lustre_lite and class_handle_init

Linux-commit: 1f4fc343c008981d3a91351c030e2c29f5cd1b1c

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Change-Id: I86d156afd71456d7d5412ebb8a2e519367d4f81d
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/23351
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Frank Zago <fzago@cray.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
---

diff --git a/lnet/lnet/router.c b/lnet/lnet/router.c
index 6d15c6c..f8a0788 100644
--- a/lnet/lnet/router.c
+++ b/lnet/lnet/router.c
@@ -239,7 +239,7 @@ static void lnet_shuffle_seed(void)
 	static int seeded;
 	__u32 lnd_type;
 	__u32 seed[2];
-	struct timeval tv;
+	struct timespec64 ts;
 	lnet_ni_t *ni;
 	struct list_head *tmp;
 
@@ -258,8 +258,8 @@ static void lnet_shuffle_seed(void)
 			seed[0] ^= (LNET_NIDADDR(ni->ni_nid) | lnd_type);
 	}
 
-	do_gettimeofday(&tv);
-	cfs_srand(tv.tv_sec ^ seed[0], tv.tv_usec ^ seed[1]);
+	ktime_get_ts64(&ts);
+	cfs_srand(ts.tv_sec ^ seed[0], ts.tv_nsec ^ seed[1]);
 	seeded = 1;
 	return;
 }
diff --git a/lustre/llite/super25.c b/lustre/llite/super25.c
index c2ebb76..3b9f748 100644
--- a/lustre/llite/super25.c
+++ b/lustre/llite/super25.c
@@ -102,7 +102,7 @@ static int __init lustre_init(void)
 {
 	struct proc_dir_entry *entry;
 	lnet_process_id_t lnet_id;
-	struct timeval tv;
+	struct timespec64 ts;
 	int i, rc, seed[2];
 
 	CLASSERT(sizeof(LUSTRE_VOLATILE_HDR) == LUSTRE_VOLATILE_HDR_LEN + 1);
@@ -147,8 +147,8 @@ static int __init lustre_init(void)
 			seed[0] ^= LNET_NIDADDR(lnet_id.nid);
 	}
 
-	do_gettimeofday(&tv);
-	cfs_srand(tv.tv_sec ^ seed[0], tv.tv_usec ^ seed[1]);
+	ktime_get_ts64(&ts);
+	cfs_srand(ts.tv_sec ^ seed[0], ts.tv_nsec ^ seed[1]);
 
 	rc = vvp_global_init();
 	if (rc != 0)
diff --git a/lustre/obdclass/lustre_handles.c b/lustre/obdclass/lustre_handles.c
index 2736695..dcdc4fa 100644
--- a/lustre/obdclass/lustre_handles.c
+++ b/lustre/obdclass/lustre_handles.c
@@ -198,7 +198,7 @@ EXPORT_SYMBOL(class_handle_free_cb);
 int class_handle_init(void)
 {
         struct handle_bucket *bucket;
-        struct timeval tv;
+	struct timespec64 ts;
         int seed[2];
 
         LASSERT(handle_hash == NULL);
@@ -216,8 +216,8 @@ int class_handle_init(void)
 
 	/** bug 21430: add randomness to the initial base */
 	cfs_get_random_bytes(seed, sizeof(seed));
-	do_gettimeofday(&tv);
-	cfs_srand(tv.tv_sec ^ seed[0], tv.tv_usec ^ seed[1]);
+	ktime_get_ts64(&ts);
+	cfs_srand(ts.tv_sec ^ seed[0], ts.tv_nsec ^ seed[1]);
 
         cfs_get_random_bytes(&handle_base, sizeof(handle_base));
         LASSERT(handle_base != 0ULL);