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Subject[PATCH 2/4] staging: lustre: replace cfs_srand() calls with add_device_randomness().
The only places that cfs_srand is called, the random bits are
mixed with bits from get_random_bytes(). So it is equally effective
to add entropy to either pool.
So we can replace calls to cfs_srand() with calls that add the
entropy with add_device_randomness(). That function adds time-based
entropy, so we can discard the ktime_get_ts64 calls.

One location in lustre_handles.c only adds timebased
entropy. This cannot improve the entropy provided by get_random_bytes(),
so just discard that call.

Signed-off-by: NeilBrown <neilb@suse.com>
---
drivers/staging/lustre/lnet/lnet/router.c | 15 ++++++---------
drivers/staging/lustre/lustre/llite/super25.c | 17 +++++++----------
.../lustre/lustre/obdclass/lustre_handles.c | 7 -------
3 files changed, 13 insertions(+), 26 deletions(-)

diff --git a/drivers/staging/lustre/lnet/lnet/router.c b/drivers/staging/lustre/lnet/lnet/router.c
index e5c9b29e199f..80a7e8a88acb 100644
--- a/drivers/staging/lustre/lnet/lnet/router.c
+++ b/drivers/staging/lustre/lnet/lnet/router.c
@@ -238,28 +238,25 @@ lnet_find_net_locked(__u32 net)
static void lnet_shuffle_seed(void)
{
static int seeded;
- __u32 lnd_type, seed[2];
- struct timespec64 ts;
struct lnet_ni *ni;

if (seeded)
return;

- cfs_get_random_bytes(seed, sizeof(seed));
-
/*
* Nodes with small feet have little entropy
* the NID for this node gives the most entropy in the low bits
*/
list_for_each_entry(ni, &the_lnet.ln_nis, ni_list) {
- lnd_type = LNET_NETTYP(LNET_NIDNET(ni->ni_nid));
+ __u32 lnd_type, seed;

- if (lnd_type != LOLND)
- seed[0] ^= (LNET_NIDADDR(ni->ni_nid) | lnd_type);
+ lnd_type = LNET_NETTYP(LNET_NIDNET(ni->ni_nid));
+ if (lnd_type != LOLND) {
+ seed = (LNET_NIDADDR(ni->ni_nid) | lnd_type);
+ add_device_randomness(&seed, sizeof(seed));
+ }
}

- ktime_get_ts64(&ts);
- cfs_srand(ts.tv_sec ^ seed[0], ts.tv_nsec ^ seed[1]);
seeded = 1;
}

diff --git a/drivers/staging/lustre/lustre/llite/super25.c b/drivers/staging/lustre/lustre/llite/super25.c
index 10105339790e..9b0bb3541a84 100644
--- a/drivers/staging/lustre/lustre/llite/super25.c
+++ b/drivers/staging/lustre/lustre/llite/super25.c
@@ -86,8 +86,7 @@ MODULE_ALIAS_FS("lustre");
static int __init lustre_init(void)
{
struct lnet_process_id lnet_id;
- struct timespec64 ts;
- int i, rc, seed[2];
+ int i, rc;

BUILD_BUG_ON(sizeof(LUSTRE_VOLATILE_HDR) !=
LUSTRE_VOLATILE_HDR_LEN + 1);
@@ -126,22 +125,20 @@ static int __init lustre_init(void)
goto out_debugfs;
}

- cfs_get_random_bytes(seed, sizeof(seed));
-
/* Nodes with small feet have little entropy. The NID for this
* node gives the most entropy in the low bits
*/
for (i = 0;; i++) {
+ u32 seed;
+
if (LNetGetId(i, &lnet_id) == -ENOENT)
break;
-
- if (LNET_NETTYP(LNET_NIDNET(lnet_id.nid)) != LOLND)
- seed[0] ^= LNET_NIDADDR(lnet_id.nid);
+ if (LNET_NETTYP(LNET_NIDNET(lnet_id.nid)) != LOLND) {
+ seed = LNET_NIDADDR(lnet_id.nid);
+ add_device_randomness(&seed, sizeof(seed));
+ }
}

- ktime_get_ts64(&ts);
- cfs_srand(ts.tv_sec ^ seed[0], ts.tv_nsec ^ seed[1]);
-
rc = vvp_global_init();
if (rc != 0)
goto out_sysfs;
diff --git a/drivers/staging/lustre/lustre/obdclass/lustre_handles.c b/drivers/staging/lustre/lustre/obdclass/lustre_handles.c
index 71329adc0318..d1b6c2f134d7 100644
--- a/drivers/staging/lustre/lustre/obdclass/lustre_handles.c
+++ b/drivers/staging/lustre/lustre/obdclass/lustre_handles.c
@@ -181,8 +181,6 @@ EXPORT_SYMBOL(class_handle_free_cb);
int class_handle_init(void)
{
struct handle_bucket *bucket;
- struct timespec64 ts;
- int seed[2];

LASSERT(!handle_hash);

@@ -198,11 +196,6 @@ int class_handle_init(void)
spin_lock_init(&bucket->lock);
}

- /** bug 21430: add randomness to the initial base */
- cfs_get_random_bytes(seed, sizeof(seed));
- 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);


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