All occurrences of cfs_rand() % X are replaced with prandom_u32_max(X)
cfs_rand() is a simple Linear Congruential PRNG. prandom_u32_max() is at least as random, is seeded with more randomness, and uses cpu-local state to avoid cross-cpu issues. This is the first step is discarding the libcfs prng with the standard linux prng. Signed-off-by: NeilBrown <[email protected]> --- drivers/staging/lustre/lnet/libcfs/fail.c | 2 + drivers/staging/lustre/lnet/lnet/net_fault.c | 38 ++++++++++++----------- drivers/staging/lustre/lnet/lnet/router.c | 4 +- drivers/staging/lustre/lustre/mgc/mgc_request.c | 4 +- 4 files changed, 25 insertions(+), 23 deletions(-) diff --git a/drivers/staging/lustre/lnet/libcfs/fail.c b/drivers/staging/lustre/lnet/libcfs/fail.c index 5d501beeb622..39439b303d65 100644 --- a/drivers/staging/lustre/lnet/libcfs/fail.c +++ b/drivers/staging/lustre/lnet/libcfs/fail.c @@ -61,7 +61,7 @@ int __cfs_fail_check_set(u32 id, u32 value, int set) /* Fail 1/cfs_fail_val times */ if (cfs_fail_loc & CFS_FAIL_RAND) { - if (cfs_fail_val < 2 || cfs_rand() % cfs_fail_val > 0) + if (cfs_fail_val < 2 || prandom_u32_max(cfs_fail_val) > 0) return 0; } diff --git a/drivers/staging/lustre/lnet/lnet/net_fault.c b/drivers/staging/lustre/lnet/lnet/net_fault.c index 0318e64c413f..e3468cef273b 100644 --- a/drivers/staging/lustre/lnet/lnet/net_fault.c +++ b/drivers/staging/lustre/lnet/lnet/net_fault.c @@ -170,10 +170,10 @@ lnet_drop_rule_add(struct lnet_fault_attr *attr) rule->dr_attr = *attr; if (attr->u.drop.da_interval) { rule->dr_time_base = cfs_time_shift(attr->u.drop.da_interval); - rule->dr_drop_time = cfs_time_shift(cfs_rand() % - attr->u.drop.da_interval); + rule->dr_drop_time = cfs_time_shift( + prandom_u32_max(attr->u.drop.da_interval)); } else { - rule->dr_drop_at = cfs_rand() % attr->u.drop.da_rate; + rule->dr_drop_at = prandom_u32_max(attr->u.drop.da_rate); } lnet_net_lock(LNET_LOCK_EX); @@ -277,10 +277,10 @@ lnet_drop_rule_reset(void) memset(&rule->dr_stat, 0, sizeof(rule->dr_stat)); if (attr->u.drop.da_rate) { - rule->dr_drop_at = cfs_rand() % attr->u.drop.da_rate; + rule->dr_drop_at = prandom_u32_max(attr->u.drop.da_rate); } else { - rule->dr_drop_time = cfs_time_shift(cfs_rand() % - attr->u.drop.da_interval); + rule->dr_drop_time = cfs_time_shift( + prandom_u32_max(attr->u.drop.da_interval)); rule->dr_time_base = cfs_time_shift(attr->u.drop.da_interval); } spin_unlock(&rule->dr_lock); @@ -315,8 +315,8 @@ drop_rule_match(struct lnet_drop_rule *rule, lnet_nid_t src, rule->dr_time_base = now; rule->dr_drop_time = rule->dr_time_base + - cfs_time_seconds(cfs_rand() % - attr->u.drop.da_interval); + cfs_time_seconds( + prandom_u32_max(attr->u.drop.da_interval)); rule->dr_time_base += cfs_time_seconds(attr->u.drop.da_interval); CDEBUG(D_NET, "Drop Rule %s->%s: next drop : %lu\n", @@ -330,7 +330,7 @@ drop_rule_match(struct lnet_drop_rule *rule, lnet_nid_t src, if (!do_div(rule->dr_stat.fs_count, attr->u.drop.da_rate)) { rule->dr_drop_at = rule->dr_stat.fs_count + - cfs_rand() % attr->u.drop.da_rate; + prandom_u32_max(attr->u.drop.da_rate); CDEBUG(D_NET, "Drop Rule %s->%s: next drop: %lu\n", libcfs_nid2str(attr->fa_src), libcfs_nid2str(attr->fa_dst), rule->dr_drop_at); @@ -483,8 +483,9 @@ delay_rule_match(struct lnet_delay_rule *rule, lnet_nid_t src, rule->dl_time_base = now; rule->dl_delay_time = rule->dl_time_base + - cfs_time_seconds(cfs_rand() % - attr->u.delay.la_interval); + cfs_time_seconds( + prandom_u32_max( + attr->u.delay.la_interval)); rule->dl_time_base += cfs_time_seconds(attr->u.delay.la_interval); CDEBUG(D_NET, "Delay Rule %s->%s: next delay : %lu\n", @@ -498,7 +499,7 @@ delay_rule_match(struct lnet_delay_rule *rule, lnet_nid_t src, /* generate the next random rate sequence */ if (!do_div(rule->dl_stat.fs_count, attr->u.delay.la_rate)) { rule->dl_delay_at = rule->dl_stat.fs_count + - cfs_rand() % attr->u.delay.la_rate; + prandom_u32_max(attr->u.delay.la_rate); CDEBUG(D_NET, "Delay Rule %s->%s: next delay: %lu\n", libcfs_nid2str(attr->fa_src), libcfs_nid2str(attr->fa_dst), rule->dl_delay_at); @@ -771,10 +772,10 @@ lnet_delay_rule_add(struct lnet_fault_attr *attr) rule->dl_attr = *attr; if (attr->u.delay.la_interval) { rule->dl_time_base = cfs_time_shift(attr->u.delay.la_interval); - rule->dl_delay_time = cfs_time_shift(cfs_rand() % - attr->u.delay.la_interval); + rule->dl_delay_time = cfs_time_shift( + prandom_u32_max(attr->u.delay.la_interval)); } else { - rule->dl_delay_at = cfs_rand() % attr->u.delay.la_rate; + rule->dl_delay_at = prandom_u32_max(attr->u.delay.la_rate); } rule->dl_msg_send = -1; @@ -920,10 +921,11 @@ lnet_delay_rule_reset(void) memset(&rule->dl_stat, 0, sizeof(rule->dl_stat)); if (attr->u.delay.la_rate) { - rule->dl_delay_at = cfs_rand() % attr->u.delay.la_rate; + rule->dl_delay_at = prandom_u32_max(attr->u.delay.la_rate); } else { - rule->dl_delay_time = cfs_time_shift(cfs_rand() % - attr->u.delay.la_interval); + rule->dl_delay_time = + cfs_time_shift(prandom_u32_max( + attr->u.delay.la_interval)); rule->dl_time_base = cfs_time_shift(attr->u.delay.la_interval); } spin_unlock(&rule->dl_lock); diff --git a/drivers/staging/lustre/lnet/lnet/router.c b/drivers/staging/lustre/lnet/lnet/router.c index c40aa79baf5c..e5c9b29e199f 100644 --- a/drivers/staging/lustre/lnet/lnet/router.c +++ b/drivers/staging/lustre/lnet/lnet/router.c @@ -277,8 +277,8 @@ lnet_add_route_to_rnet(struct lnet_remotenet *rnet, struct lnet_route *route) len++; } - /* len+1 positions to add a new entry, also prevents division by 0 */ - offset = cfs_rand() % (len + 1); + /* len+1 positions to add a new entry */ + offset = prandom_u32_max(len + 1); list_for_each(e, &rnet->lrn_routes) { if (!offset) break; diff --git a/drivers/staging/lustre/lustre/mgc/mgc_request.c b/drivers/staging/lustre/lustre/mgc/mgc_request.c index 77fa8fea0249..79ff85feab64 100644 --- a/drivers/staging/lustre/lustre/mgc/mgc_request.c +++ b/drivers/staging/lustre/lustre/mgc/mgc_request.c @@ -523,7 +523,7 @@ static void do_requeue(struct config_llog_data *cld) * in order to not flood the MGS. */ #define MGC_TIMEOUT_MIN_SECONDS 5 -#define MGC_TIMEOUT_RAND_CENTISEC 0x1ff /* ~500 */ +#define MGC_TIMEOUT_RAND_CENTISEC 500 static int mgc_requeue_thread(void *data) { @@ -537,7 +537,7 @@ static int mgc_requeue_thread(void *data) while (!(rq_state & RQ_STOP)) { struct l_wait_info lwi; struct config_llog_data *cld, *cld_prev; - int rand = cfs_rand() & MGC_TIMEOUT_RAND_CENTISEC; + int rand = prandom_u32_max(MGC_TIMEOUT_RAND_CENTISEC); int to; /* Any new or requeued lostlocks will change the state */
