From 65d042a1b4e3169c44bbb0fca5f0746e04ae6a4e Mon Sep 17 00:00:00 2001 From: Hao Zheng Date: Fri, 8 Oct 2010 16:26:15 -0700 Subject: [PATCH] datapath: fix flow used time stats This commit fixes a problem where datapath flow used stats can report incorrent value, thus may result in flow expirations being incorrect. This happens when a kernel jiffies rollover occurs between the last time a flow is hit and the flow stats is queried. Acked-by: Jesse Gross Signed-off-by: Hao Zheng --- datapath/datapath.c | 54 ++++++++++++++------------------------------- 1 file changed, 16 insertions(+), 38 deletions(-) diff --git a/datapath/datapath.c b/datapath/datapath.c index eddc4ab9b..6829ad0bf 100644 --- a/datapath/datapath.c +++ b/datapath/datapath.c @@ -976,24 +976,15 @@ error: return ERR_PTR(error); } -static struct timespec get_time_offset(void) -{ - struct timespec now_mono, now_jiffies; - - ktime_get_ts(&now_mono); - jiffies_to_timespec(jiffies, &now_jiffies); - return timespec_sub(now_mono, now_jiffies); -} - -static void get_stats(struct sw_flow *flow, struct odp_flow_stats *stats, - struct timespec time_offset) +static void get_stats(struct sw_flow *flow, struct odp_flow_stats *stats) { if (flow->used) { - struct timespec flow_ts, used; + struct timespec offset_ts, used, now_mono; - jiffies_to_timespec(flow->used, &flow_ts); - set_normalized_timespec(&used, flow_ts.tv_sec + time_offset.tv_sec, - flow_ts.tv_nsec + time_offset.tv_nsec); + ktime_get_ts(&now_mono); + jiffies_to_timespec(jiffies - flow->used, &offset_ts); + set_normalized_timespec(&used, now_mono.tv_sec - offset_ts.tv_sec, + now_mono.tv_nsec - offset_ts.tv_nsec); stats->used_sec = used.tv_sec; stats->used_nsec = used.tv_nsec; @@ -1108,7 +1099,7 @@ static int do_put_flow(struct datapath *dp, struct odp_flow_put *uf, /* Fetch stats, then clear them if necessary. */ spin_lock_bh(&flow->lock); - get_stats(flow, stats, get_time_offset()); + get_stats(flow, stats); if (uf->flags & ODPPF_ZERO_STATS) clear_stats(flow); spin_unlock_bh(&flow->lock); @@ -1146,7 +1137,6 @@ static int put_flow(struct datapath *dp, struct odp_flow_put __user *ufp) } static int do_answer_query(struct sw_flow *flow, u32 query_flags, - struct timespec time_offset, struct odp_flow_stats __user *ustats, union odp_action __user *actions, u32 __user *n_actionsp) @@ -1156,7 +1146,7 @@ static int do_answer_query(struct sw_flow *flow, u32 query_flags, u32 n_actions; spin_lock_bh(&flow->lock); - get_stats(flow, &stats, time_offset); + get_stats(flow, &stats); if (query_flags & ODPFF_ZERO_TCP_FLAGS) flow->tcp_flags = 0; @@ -1180,7 +1170,6 @@ static int do_answer_query(struct sw_flow *flow, u32 query_flags, } static int answer_query(struct sw_flow *flow, u32 query_flags, - struct timespec time_offset, struct odp_flow __user *ufp) { union odp_action *actions; @@ -1188,7 +1177,7 @@ static int answer_query(struct sw_flow *flow, u32 query_flags, if (get_user(actions, &ufp->actions)) return -EFAULT; - return do_answer_query(flow, query_flags, time_offset, + return do_answer_query(flow, query_flags, &ufp->stats, actions, &ufp->n_actions); } @@ -1226,7 +1215,7 @@ static int del_flow(struct datapath *dp, struct odp_flow __user *ufp) if (IS_ERR(flow)) return PTR_ERR(flow); - error = answer_query(flow, 0, get_time_offset(), ufp); + error = answer_query(flow, 0, ufp); flow_deferred_free(flow); return error; } @@ -1234,11 +1223,8 @@ static int del_flow(struct datapath *dp, struct odp_flow __user *ufp) static int do_query_flows(struct datapath *dp, const struct odp_flowvec *flowvec) { struct tbl *table = rcu_dereference(dp->table); - struct timespec time_offset; u32 i; - time_offset = get_time_offset(); - for (i = 0; i < flowvec->n_flows; i++) { struct odp_flow __user *ufp = &flowvec->flows[i]; struct odp_flow uf; @@ -1252,7 +1238,7 @@ static int do_query_flows(struct datapath *dp, const struct odp_flowvec *flowvec if (!flow_node) error = put_user(ENOENT, &ufp->stats.error); else - error = answer_query(flow_cast(flow_node), uf.flags, time_offset, ufp); + error = answer_query(flow_cast(flow_node), uf.flags, ufp); if (error) return -EFAULT; } @@ -1263,7 +1249,6 @@ struct list_flows_cbdata { struct odp_flow __user *uflows; u32 n_flows; u32 listed_flows; - struct timespec time_offset; }; static int list_flow(struct tbl_node *node, void *cbdata_) @@ -1275,7 +1260,7 @@ static int list_flow(struct tbl_node *node, void *cbdata_) if (copy_to_user(&ufp->key, &flow->key, sizeof flow->key)) return -EFAULT; - error = answer_query(flow, 0, cbdata->time_offset, ufp); + error = answer_query(flow, 0, ufp); if (error) return error; @@ -1295,7 +1280,6 @@ static int do_list_flows(struct datapath *dp, const struct odp_flowvec *flowvec) cbdata.uflows = flowvec->flows; cbdata.n_flows = flowvec->n_flows; cbdata.listed_flows = 0; - cbdata.time_offset = get_time_offset(); error = tbl_foreach(rcu_dereference(dp->table), list_flow, &cbdata); return error ? error : cbdata.listed_flows; @@ -1801,7 +1785,6 @@ static int compat_put_flow(struct datapath *dp, struct compat_odp_flow_put __use } static int compat_answer_query(struct sw_flow *flow, u32 query_flags, - struct timespec time_offset, struct compat_odp_flow __user *ufp) { compat_uptr_t actions; @@ -1809,7 +1792,7 @@ static int compat_answer_query(struct sw_flow *flow, u32 query_flags, if (get_user(actions, &ufp->actions)) return -EFAULT; - return do_answer_query(flow, query_flags, time_offset, &ufp->stats, + return do_answer_query(flow, query_flags, &ufp->stats, compat_ptr(actions), &ufp->n_actions); } @@ -1826,7 +1809,7 @@ static int compat_del_flow(struct datapath *dp, struct compat_odp_flow __user *u if (IS_ERR(flow)) return PTR_ERR(flow); - error = compat_answer_query(flow, 0, get_time_offset(), ufp); + error = compat_answer_query(flow, 0, ufp); flow_deferred_free(flow); return error; } @@ -1834,11 +1817,8 @@ static int compat_del_flow(struct datapath *dp, struct compat_odp_flow __user *u static int compat_query_flows(struct datapath *dp, struct compat_odp_flow *flows, u32 n_flows) { struct tbl *table = rcu_dereference(dp->table); - struct timespec time_offset; u32 i; - time_offset = get_time_offset(); - for (i = 0; i < n_flows; i++) { struct compat_odp_flow __user *ufp = &flows[i]; struct odp_flow uf; @@ -1853,7 +1833,7 @@ static int compat_query_flows(struct datapath *dp, struct compat_odp_flow *flows if (!flow_node) error = put_user(ENOENT, &ufp->stats.error); else - error = compat_answer_query(flow_cast(flow_node), uf.flags, time_offset, ufp); + error = compat_answer_query(flow_cast(flow_node), uf.flags, ufp); if (error) return -EFAULT; } @@ -1864,7 +1844,6 @@ struct compat_list_flows_cbdata { struct compat_odp_flow __user *uflows; u32 n_flows; u32 listed_flows; - struct timespec time_offset; }; static int compat_list_flow(struct tbl_node *node, void *cbdata_) @@ -1876,7 +1855,7 @@ static int compat_list_flow(struct tbl_node *node, void *cbdata_) if (copy_to_user(&ufp->key, &flow->key, sizeof flow->key)) return -EFAULT; - error = compat_answer_query(flow, 0, cbdata->time_offset, ufp); + error = compat_answer_query(flow, 0, ufp); if (error) return error; @@ -1896,7 +1875,6 @@ static int compat_list_flows(struct datapath *dp, struct compat_odp_flow *flows, cbdata.uflows = flows; cbdata.n_flows = n_flows; cbdata.listed_flows = 0; - cbdata.time_offset = get_time_offset(); error = tbl_foreach(rcu_dereference(dp->table), compat_list_flow, &cbdata); return error ? error : cbdata.listed_flows; -- 2.43.0