linux-stable/net/openvswitch/flow_table.h
Eelco Chaudron f981fc3d51 net: openvswitch: fix to make sure flow_lookup() is not preempted
The flow_lookup() function uses per CPU variables, which must be called
with BH disabled. However, this is fine in the general NAPI use case
where the local BH is disabled. But, it's also called from the netlink
context. The below patch makes sure that even in the netlink path, the
BH is disabled.

In addition, u64_stats_update_begin() requires a lock to ensure one writer
which is not ensured here. Making it per-CPU and disabling NAPI (softirq)
ensures that there is always only one writer.

Fixes: eac87c413b ("net: openvswitch: reorder masks array based on usage")
Reported-by: Juri Lelli <jlelli@redhat.com>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://lore.kernel.org/r/160295903253.7789.826736662555102345.stgit@ebuild
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-18 12:29:36 -07:00

115 lines
3.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (c) 2007-2013 Nicira, Inc.
*/
#ifndef FLOW_TABLE_H
#define FLOW_TABLE_H 1
#include <linux/kernel.h>
#include <linux/netlink.h>
#include <linux/openvswitch.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/rcupdate.h>
#include <linux/if_ether.h>
#include <linux/in6.h>
#include <linux/jiffies.h>
#include <linux/time.h>
#include <net/inet_ecn.h>
#include <net/ip_tunnels.h>
#include "flow.h"
struct mask_cache_entry {
u32 skb_hash;
u32 mask_index;
};
struct mask_cache {
struct rcu_head rcu;
u32 cache_size; /* Must be ^2 value. */
struct mask_cache_entry __percpu *mask_cache;
};
struct mask_count {
int index;
u64 counter;
};
struct mask_array_stats {
struct u64_stats_sync syncp;
u64 usage_cntrs[];
};
struct mask_array {
struct rcu_head rcu;
int count, max;
struct mask_array_stats __percpu *masks_usage_stats;
u64 *masks_usage_zero_cntr;
struct sw_flow_mask __rcu *masks[];
};
struct table_instance {
struct hlist_head *buckets;
unsigned int n_buckets;
struct rcu_head rcu;
int node_ver;
u32 hash_seed;
};
struct flow_table {
struct table_instance __rcu *ti;
struct table_instance __rcu *ufid_ti;
struct mask_cache __rcu *mask_cache;
struct mask_array __rcu *mask_array;
unsigned long last_rehash;
unsigned int count;
unsigned int ufid_count;
};
extern struct kmem_cache *flow_stats_cache;
int ovs_flow_init(void);
void ovs_flow_exit(void);
struct sw_flow *ovs_flow_alloc(void);
void ovs_flow_free(struct sw_flow *, bool deferred);
int ovs_flow_tbl_init(struct flow_table *);
int ovs_flow_tbl_count(const struct flow_table *table);
void ovs_flow_tbl_destroy(struct flow_table *table);
int ovs_flow_tbl_flush(struct flow_table *flow_table);
int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
const struct sw_flow_mask *mask);
void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow);
int ovs_flow_tbl_num_masks(const struct flow_table *table);
u32 ovs_flow_tbl_masks_cache_size(const struct flow_table *table);
int ovs_flow_tbl_masks_cache_resize(struct flow_table *table, u32 size);
struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *table,
u32 *bucket, u32 *idx);
struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *,
const struct sw_flow_key *,
u32 skb_hash,
u32 *n_mask_hit,
u32 *n_cache_hit);
struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *,
const struct sw_flow_key *);
struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl,
const struct sw_flow_match *match);
struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *,
const struct sw_flow_id *);
bool ovs_flow_cmp(const struct sw_flow *, const struct sw_flow_match *);
void ovs_flow_mask_key(struct sw_flow_key *dst, const struct sw_flow_key *src,
bool full, const struct sw_flow_mask *mask);
void ovs_flow_masks_rebalance(struct flow_table *table);
void table_instance_flow_flush(struct flow_table *table,
struct table_instance *ti,
struct table_instance *ufid_ti);
#endif /* flow_table.h */