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Commit 2373ce1c authored by Robert Olsson's avatar Robert Olsson Committed by David S. Miller
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[IPV4]: Convert FIB Trie to RCU. 

* Removes RW-lock
* Proteced read functions uses
  rcu_dereference proteced with rcu_read_lock()
* writing of procted pointer w. rcu_assigen_pointer
* Insert/Replace atomic list_replace_rcu
* A BUG_ON condition removed.in trie_rebalance

With help from Paul E. McKenney.
Signed-off-by: default avatarRobert Olsson <Robert.Olsson@data.slu.se>
Signed-off-by: default avatarStephen Hemminger <shemminger@osdl.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e5b43760
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Showing with 202 additions and 187 deletions
net/ipv4/fib_trie.c
View file @ 2373ce1c
...@@ -43,7 +43,7 @@ ...@@ -43,7 +43,7 @@
* 2 of the License, or (at your option) any later version. * 2 of the License, or (at your option) any later version.
*/ */
#define VERSION "0.325" #define VERSION "0.402"
#include <linux/config.h> #include <linux/config.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
...@@ -62,6 +62,7 @@ ...@@ -62,6 +62,7 @@
#include <linux/netdevice.h> #include <linux/netdevice.h>
#include <linux/if_arp.h> #include <linux/if_arp.h>
#include <linux/proc_fs.h> #include <linux/proc_fs.h>
#include <linux/rcupdate.h>
#include <linux/skbuff.h> #include <linux/skbuff.h>
#include <linux/netlink.h> #include <linux/netlink.h>
#include <linux/init.h> #include <linux/init.h>
...@@ -81,22 +82,19 @@ ...@@ -81,22 +82,19 @@
#define MASK_PFX(k, l) (((l)==0)?0:(k >> (KEYLENGTH-l)) << (KEYLENGTH-l)) #define MASK_PFX(k, l) (((l)==0)?0:(k >> (KEYLENGTH-l)) << (KEYLENGTH-l))
#define TKEY_GET_MASK(offset, bits) (((bits)==0)?0:((t_key)(-1) << (KEYLENGTH - bits) >> offset)) #define TKEY_GET_MASK(offset, bits) (((bits)==0)?0:((t_key)(-1) << (KEYLENGTH - bits) >> offset))
static DEFINE_RWLOCK(fib_lock);
typedef unsigned int t_key; typedef unsigned int t_key;
#define T_TNODE 0 #define T_TNODE 0
#define T_LEAF 1 #define T_LEAF 1
#define NODE_TYPE_MASK 0x1UL #define NODE_TYPE_MASK 0x1UL
#define NODE_PARENT(node) \ #define NODE_PARENT(node) \
((struct tnode *)((node)->parent & ~NODE_TYPE_MASK)) ((struct tnode *)rcu_dereference(((node)->parent & ~NODE_TYPE_MASK)))
#define NODE_SET_PARENT(node, ptr) \
((node)->parent = (((unsigned long)(ptr)) | \ #define NODE_TYPE(node) ((node)->parent & NODE_TYPE_MASK)
((node)->parent & NODE_TYPE_MASK)))
#define NODE_INIT_PARENT(node, type) \ #define NODE_SET_PARENT(node, ptr) \
((node)->parent = (type)) rcu_assign_pointer((node)->parent, \
#define NODE_TYPE(node) \ ((unsigned long)(ptr)) | NODE_TYPE(node))
((node)->parent & NODE_TYPE_MASK)
#define IS_TNODE(n) (!(n->parent & T_LEAF)) #define IS_TNODE(n) (!(n->parent & T_LEAF))
#define IS_LEAF(n) (n->parent & T_LEAF) #define IS_LEAF(n) (n->parent & T_LEAF)
...@@ -110,10 +108,12 @@ struct leaf { ...@@ -110,10 +108,12 @@ struct leaf {
t_key key; t_key key;
unsigned long parent; unsigned long parent;
struct hlist_head list; struct hlist_head list;
struct rcu_head rcu;
}; };
struct leaf_info { struct leaf_info {
struct hlist_node hlist; struct hlist_node hlist;
struct rcu_head rcu;
int plen; int plen;
struct list_head falh; struct list_head falh;
}; };
...@@ -125,6 +125,7 @@ struct tnode { ...@@ -125,6 +125,7 @@ struct tnode {
unsigned short bits:5; /* 2log(KEYLENGTH) bits needed */ unsigned short bits:5; /* 2log(KEYLENGTH) bits needed */
unsigned short full_children; /* KEYLENGTH bits needed */ unsigned short full_children; /* KEYLENGTH bits needed */
unsigned short empty_children; /* KEYLENGTH bits needed */ unsigned short empty_children; /* KEYLENGTH bits needed */
struct rcu_head rcu;
struct node *child[0]; struct node *child[0];
}; };
...@@ -168,11 +169,14 @@ static void trie_dump_seq(struct seq_file *seq, struct trie *t); ...@@ -168,11 +169,14 @@ static void trie_dump_seq(struct seq_file *seq, struct trie *t);
static kmem_cache_t *fn_alias_kmem; static kmem_cache_t *fn_alias_kmem;
static struct trie *trie_local = NULL, *trie_main = NULL; static struct trie *trie_local = NULL, *trie_main = NULL;
/* rcu_read_lock needs to be hold by caller from readside */
static inline struct node *tnode_get_child(struct tnode *tn, int i) static inline struct node *tnode_get_child(struct tnode *tn, int i)
{ {
BUG_ON(i >= 1 << tn->bits); BUG_ON(i >= 1 << tn->bits);
return tn->child[i]; return rcu_dereference(tn->child[i]);
} }
static inline int tnode_child_length(const struct tnode *tn) static inline int tnode_child_length(const struct tnode *tn)
...@@ -213,14 +217,6 @@ static inline int tkey_mismatch(t_key a, int offset, t_key b) ...@@ -213,14 +217,6 @@ static inline int tkey_mismatch(t_key a, int offset, t_key b)
return i; return i;
} }
/* Candidate for fib_semantics */
static void fn_free_alias(struct fib_alias *fa)
{
fib_release_info(fa->fa_info);
kmem_cache_free(fn_alias_kmem, fa);
}
/* /*
To understand this stuff, an understanding of keys and all their bits is To understand this stuff, an understanding of keys and all their bits is
necessary. Every node in the trie has a key associated with it, but not necessary. Every node in the trie has a key associated with it, but not
...@@ -292,53 +288,57 @@ static inline void check_tnode(const struct tnode *tn) ...@@ -292,53 +288,57 @@ static inline void check_tnode(const struct tnode *tn)
static int halve_threshold = 25; static int halve_threshold = 25;
static int inflate_threshold = 50; static int inflate_threshold = 50;
static struct leaf *leaf_new(void)
static void __alias_free_mem(struct rcu_head *head)
{ {
struct leaf *l = kmalloc(sizeof(struct leaf), GFP_KERNEL); struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
if (l) { kmem_cache_free(fn_alias_kmem, fa);
NODE_INIT_PARENT(l, T_LEAF);
INIT_HLIST_HEAD(&l->list);
}
return l;
} }
static struct leaf_info *leaf_info_new(int plen) static inline void alias_free_mem_rcu(struct fib_alias *fa)
{ {
struct leaf_info *li = kmalloc(sizeof(struct leaf_info), GFP_KERNEL); call_rcu(&fa->rcu, __alias_free_mem);
}
if (!li)
return NULL;
li->plen = plen; static void __leaf_free_rcu(struct rcu_head *head)
INIT_LIST_HEAD(&li->falh); {
kfree(container_of(head, struct leaf, rcu));
}
return li; static inline void free_leaf(struct leaf *leaf)
{
call_rcu(&leaf->rcu, __leaf_free_rcu);
} }
static inline void free_leaf(struct leaf *l) static void __leaf_info_free_rcu(struct rcu_head *head)
{ {
kfree(l); kfree(container_of(head, struct leaf_info, rcu));
} }
static inline void free_leaf_info(struct leaf_info *li) static inline void free_leaf_info(struct leaf_info *leaf)
{ {
kfree(li); call_rcu(&leaf->rcu, __leaf_info_free_rcu);
} }
static struct tnode *tnode_alloc(unsigned int size) static struct tnode *tnode_alloc(unsigned int size)
{ {
if (size <= PAGE_SIZE) { struct page *pages;
return kmalloc(size, GFP_KERNEL);
} else { if (size <= PAGE_SIZE)
return (struct tnode *) return kcalloc(size, 1, GFP_KERNEL);
__get_free_pages(GFP_KERNEL, get_order(size));
} pages = alloc_pages(GFP_KERNEL|__GFP_ZERO, get_order(size));
if (!pages)
return NULL;
return page_address(pages);
} }
static void __tnode_free(struct tnode *tn) static void __tnode_free_rcu(struct rcu_head *head)
{ {
struct tnode *tn = container_of(head, struct tnode, rcu);
unsigned int size = sizeof(struct tnode) + unsigned int size = sizeof(struct tnode) +
(1 << tn->bits) * sizeof(struct node *); (1 << tn->bits) * sizeof(struct node *);
if (size <= PAGE_SIZE) if (size <= PAGE_SIZE)
kfree(tn); kfree(tn);
...@@ -346,6 +346,31 @@ static void __tnode_free(struct tnode *tn) ...@@ -346,6 +346,31 @@ static void __tnode_free(struct tnode *tn)
free_pages((unsigned long)tn, get_order(size)); free_pages((unsigned long)tn, get_order(size));
} }
static inline void tnode_free(struct tnode *tn)
{
call_rcu(&tn->rcu, __tnode_free_rcu);
}
static struct leaf *leaf_new(void)
{
struct leaf *l = kmalloc(sizeof(struct leaf), GFP_KERNEL);
if (l) {
l->parent = T_LEAF;
INIT_HLIST_HEAD(&l->list);
}
return l;
}
static struct leaf_info *leaf_info_new(int plen)
{
struct leaf_info *li = kmalloc(sizeof(struct leaf_info), GFP_KERNEL);
if (li) {
li->plen = plen;
INIT_LIST_HEAD(&li->falh);
}
return li;
}
static struct tnode* tnode_new(t_key key, int pos, int bits) static struct tnode* tnode_new(t_key key, int pos, int bits)
{ {
int nchildren = 1<<bits; int nchildren = 1<<bits;
...@@ -354,7 +379,7 @@ static struct tnode* tnode_new(t_key key, int pos, int bits) ...@@ -354,7 +379,7 @@ static struct tnode* tnode_new(t_key key, int pos, int bits)
if (tn) { if (tn) {
memset(tn, 0, sz); memset(tn, 0, sz);
NODE_INIT_PARENT(tn, T_TNODE); tn->parent = T_TNODE;
tn->pos = pos; tn->pos = pos;
tn->bits = bits; tn->bits = bits;
tn->key = key; tn->key = key;
...@@ -367,17 +392,6 @@ static struct tnode* tnode_new(t_key key, int pos, int bits) ...@@ -367,17 +392,6 @@ static struct tnode* tnode_new(t_key key, int pos, int bits)
return tn; return tn;
} }
static void tnode_free(struct tnode *tn)
{
if (IS_LEAF(tn)) {
free_leaf((struct leaf *)tn);
pr_debug("FL %p \n", tn);
} else {
__tnode_free(tn);
pr_debug("FT %p \n", tn);
}
}
/* /*
* Check whether a tnode 'n' is "full", i.e. it is an internal node * Check whether a tnode 'n' is "full", i.e. it is an internal node
* and no bits are skipped. See discussion in dyntree paper p. 6 * and no bits are skipped. See discussion in dyntree paper p. 6
...@@ -403,13 +417,11 @@ static inline void put_child(struct trie *t, struct tnode *tn, int i, struct nod ...@@ -403,13 +417,11 @@ static inline void put_child(struct trie *t, struct tnode *tn, int i, struct nod
static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int wasfull) static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int wasfull)
{ {
struct node *chi; struct node *chi = tn->child[i];
int isfull; int isfull;
BUG_ON(i >= 1<<tn->bits); BUG_ON(i >= 1<<tn->bits);
write_lock_bh(&fib_lock);
chi = tn->child[i];
/* update emptyChildren */ /* update emptyChildren */
if (n == NULL && chi != NULL) if (n == NULL && chi != NULL)
...@@ -430,8 +442,7 @@ static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int w ...@@ -430,8 +442,7 @@ static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int w
if (n) if (n)
NODE_SET_PARENT(n, tn); NODE_SET_PARENT(n, tn);
tn->child[i] = n; rcu_assign_pointer(tn->child[i], n);
write_unlock_bh(&fib_lock);
} }
static struct node *resize(struct trie *t, struct tnode *tn) static struct node *resize(struct trie *t, struct tnode *tn)
...@@ -456,17 +467,12 @@ static struct node *resize(struct trie *t, struct tnode *tn) ...@@ -456,17 +467,12 @@ static struct node *resize(struct trie *t, struct tnode *tn)
for (i = 0; i < tnode_child_length(tn); i++) { for (i = 0; i < tnode_child_length(tn); i++) {
struct node *n; struct node *n;
write_lock_bh(&fib_lock);
n = tn->child[i]; n = tn->child[i];
if (!n) { if (!n)
write_unlock_bh(&fib_lock);
continue; continue;
}
/* compress one level */ /* compress one level */
NODE_INIT_PARENT(n, NODE_TYPE(n)); NODE_SET_PARENT(n, NULL);
write_unlock_bh(&fib_lock);
tnode_free(tn); tnode_free(tn);
return n; return n;
} }
...@@ -577,24 +583,17 @@ static struct node *resize(struct trie *t, struct tnode *tn) ...@@ -577,24 +583,17 @@ static struct node *resize(struct trie *t, struct tnode *tn)
/* Only one child remains */ /* Only one child remains */
if (tn->empty_children == tnode_child_length(tn) - 1) if (tn->empty_children == tnode_child_length(tn) - 1)
for (i = 0; i < tnode_child_length(tn); i++) { for (i = 0; i < tnode_child_length(tn); i++) {
struct node *n; struct node *n;
write_lock_bh(&fib_lock);
n = tn->child[i]; n = tn->child[i];
if (!n) { if (!n)
write_unlock_bh(&fib_lock);
continue; continue;
}
/* compress one level */ /* compress one level */
NODE_INIT_PARENT(n, NODE_TYPE(n)); NODE_SET_PARENT(n, NULL);
write_unlock_bh(&fib_lock);
tnode_free(tn); tnode_free(tn);
return n; return n;
} }
...@@ -831,19 +830,22 @@ static void trie_init(struct trie *t) ...@@ -831,19 +830,22 @@ static void trie_init(struct trie *t)
return; return;
t->size = 0; t->size = 0;
t->trie = NULL; rcu_assign_pointer(t->trie, NULL);
t->revision = 0; t->revision = 0;
#ifdef CONFIG_IP_FIB_TRIE_STATS #ifdef CONFIG_IP_FIB_TRIE_STATS
memset(&t->stats, 0, sizeof(struct trie_use_stats)); memset(&t->stats, 0, sizeof(struct trie_use_stats));
#endif #endif
} }
/* readside most use rcu_read_lock currently dump routines
via get_fa_head and dump */
static struct leaf_info *find_leaf_info(struct hlist_head *head, int plen) static struct leaf_info *find_leaf_info(struct hlist_head *head, int plen)
{ {
struct hlist_node *node; struct hlist_node *node;
struct leaf_info *li; struct leaf_info *li;
hlist_for_each_entry(li, node, head, hlist) hlist_for_each_entry_rcu(li, node, head, hlist)
if (li->plen == plen) if (li->plen == plen)
return li; return li;
...@@ -862,28 +864,27 @@ static inline struct list_head * get_fa_head(struct leaf *l, int plen) ...@@ -862,28 +864,27 @@ static inline struct list_head * get_fa_head(struct leaf *l, int plen)
static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new) static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new)
{ {
struct leaf_info *li = NULL, *last = NULL; struct leaf_info *li = NULL, *last = NULL;
struct hlist_node *node; struct hlist_node *node;
write_lock_bh(&fib_lock); if (hlist_empty(head)) {
hlist_add_head_rcu(&new->hlist, head);
} else {
hlist_for_each_entry(li, node, head, hlist) {
if (new->plen > li->plen)
break;
if (hlist_empty(head)) { last = li;
hlist_add_head(&new->hlist, head); }
} else { if (last)
hlist_for_each_entry(li, node, head, hlist) { hlist_add_after_rcu(&last->hlist, &new->hlist);
if (new->plen > li->plen) else
break; hlist_add_before_rcu(&new->hlist, &li->hlist);
}
last = li;
}
if (last)
hlist_add_after(&last->hlist, &new->hlist);
else
hlist_add_before(&new->hlist, &li->hlist);
}
write_unlock_bh(&fib_lock);
} }
/* rcu_read_lock needs to be hold by caller from readside */
static struct leaf * static struct leaf *
fib_find_node(struct trie *t, u32 key) fib_find_node(struct trie *t, u32 key)
{ {
...@@ -892,7 +893,7 @@ fib_find_node(struct trie *t, u32 key) ...@@ -892,7 +893,7 @@ fib_find_node(struct trie *t, u32 key)
struct node *n; struct node *n;
pos = 0; pos = 0;
n = t->trie; n = rcu_dereference(t->trie);
while (n != NULL && NODE_TYPE(n) == T_TNODE) { while (n != NULL && NODE_TYPE(n) == T_TNODE) {
tn = (struct tnode *) n; tn = (struct tnode *) n;
...@@ -915,17 +916,13 @@ fib_find_node(struct trie *t, u32 key) ...@@ -915,17 +916,13 @@ fib_find_node(struct trie *t, u32 key)
static struct node *trie_rebalance(struct trie *t, struct tnode *tn) static struct node *trie_rebalance(struct trie *t, struct tnode *tn)
{ {
int i;
int wasfull; int wasfull;
t_key cindex, key; t_key cindex, key;
struct tnode *tp = NULL; struct tnode *tp = NULL;
key = tn->key; key = tn->key;
i = 0;
while (tn != NULL && NODE_PARENT(tn) != NULL) { while (tn != NULL && NODE_PARENT(tn) != NULL) {
BUG_ON(i > 12); /* Why is this a bug? -ojn */
i++;
tp = NODE_PARENT(tn); tp = NODE_PARENT(tn);
cindex = tkey_extract_bits(key, tp->pos, tp->bits); cindex = tkey_extract_bits(key, tp->pos, tp->bits);
...@@ -945,6 +942,8 @@ static struct node *trie_rebalance(struct trie *t, struct tnode *tn) ...@@ -945,6 +942,8 @@ static struct node *trie_rebalance(struct trie *t, struct tnode *tn)
return (struct node*) tn; return (struct node*) tn;
} }
/* only used from updater-side */
static struct list_head * static struct list_head *
fib_insert_node(struct trie *t, int *err, u32 key, int plen) fib_insert_node(struct trie *t, int *err, u32 key, int plen)
{ {
...@@ -1081,7 +1080,7 @@ fib_insert_node(struct trie *t, int *err, u32 key, int plen) ...@@ -1081,7 +1080,7 @@ fib_insert_node(struct trie *t, int *err, u32 key, int plen)
cindex = tkey_extract_bits(key, tp->pos, tp->bits); cindex = tkey_extract_bits(key, tp->pos, tp->bits);
put_child(t, (struct tnode *)tp, cindex, (struct node *)tn); put_child(t, (struct tnode *)tp, cindex, (struct node *)tn);
} else { } else {
t->trie = (struct node*) tn; /* First tnode */ rcu_assign_pointer(t->trie, (struct node *)tn); /* First tnode */
tp = tn; tp = tn;
} }
} }
...@@ -1091,7 +1090,8 @@ fib_insert_node(struct trie *t, int *err, u32 key, int plen) ...@@ -1091,7 +1090,8 @@ fib_insert_node(struct trie *t, int *err, u32 key, int plen)
tp, tp->pos, tp->bits, key, plen); tp, tp->pos, tp->bits, key, plen);
/* Rebalance the trie */ /* Rebalance the trie */
t->trie = trie_rebalance(t, tp);
rcu_assign_pointer(t->trie, trie_rebalance(t, tp));
done: done:
t->revision++; t->revision++;
err: err:
...@@ -1166,16 +1166,21 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta, ...@@ -1166,16 +1166,21 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
struct fib_info *fi_drop; struct fib_info *fi_drop;
u8 state; u8 state;
write_lock_bh(&fib_lock); err = -ENOBUFS;
new_fa = kmem_cache_alloc(fn_alias_kmem, SLAB_KERNEL);
if (new_fa == NULL)
goto out;
fi_drop = fa->fa_info; fi_drop = fa->fa_info;
fa->fa_info = fi; new_fa->fa_tos = fa->fa_tos;
fa->fa_type = type; new_fa->fa_info = fi;
fa->fa_scope = r->rtm_scope; new_fa->fa_type = type;
new_fa->fa_scope = r->rtm_scope;
state = fa->fa_state; state = fa->fa_state;
fa->fa_state &= ~FA_S_ACCESSED; new_fa->fa_state &= ~FA_S_ACCESSED;
write_unlock_bh(&fib_lock); list_replace_rcu(&fa->fa_list, &new_fa->fa_list);
alias_free_mem_rcu(fa);
fib_release_info(fi_drop); fib_release_info(fi_drop);
if (state & FA_S_ACCESSED) if (state & FA_S_ACCESSED)
...@@ -1227,11 +1232,8 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta, ...@@ -1227,11 +1232,8 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
goto out_free_new_fa; goto out_free_new_fa;
} }
write_lock_bh(&fib_lock); list_add_tail_rcu(&new_fa->fa_list,
(fa ? &fa->fa_list : fa_head));
list_add_tail(&new_fa->fa_list, (fa ? &fa->fa_list : fa_head));
write_unlock_bh(&fib_lock);
rt_cache_flush(-1); rt_cache_flush(-1);
rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id, nlhdr, req); rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id, nlhdr, req);
...@@ -1246,6 +1248,8 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta, ...@@ -1246,6 +1248,8 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
return err; return err;
} }
/* should be clalled with rcu_read_lock */
static inline int check_leaf(struct trie *t, struct leaf *l, static inline int check_leaf(struct trie *t, struct leaf *l,
t_key key, int *plen, const struct flowi *flp, t_key key, int *plen, const struct flowi *flp,
struct fib_result *res) struct fib_result *res)
...@@ -1256,7 +1260,7 @@ static inline int check_leaf(struct trie *t, struct leaf *l, ...@@ -1256,7 +1260,7 @@ static inline int check_leaf(struct trie *t, struct leaf *l,
struct hlist_head *hhead = &l->list; struct hlist_head *hhead = &l->list;
struct hlist_node *node; struct hlist_node *node;
hlist_for_each_entry(li, node, hhead, hlist) { hlist_for_each_entry_rcu(li, node, hhead, hlist) {
i = li->plen; i = li->plen;
mask = ntohl(inet_make_mask(i)); mask = ntohl(inet_make_mask(i));
if (l->key != (key & mask)) if (l->key != (key & mask))
...@@ -1292,10 +1296,9 @@ fn_trie_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result ...@@ -1292,10 +1296,9 @@ fn_trie_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result
t_key node_prefix, key_prefix, pref_mismatch; t_key node_prefix, key_prefix, pref_mismatch;
int mp; int mp;
n = t->trie; rcu_read_lock();
read_lock(&fib_lock);
n = rcu_dereference(t->trie);
if (!n) if (!n)
goto failed; goto failed;
...@@ -1465,10 +1468,11 @@ fn_trie_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result ...@@ -1465,10 +1468,11 @@ fn_trie_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result
failed: failed:
ret = 1; ret = 1;
found: found:
read_unlock(&fib_lock); rcu_read_unlock();
return ret; return ret;
} }
/* only called from updater side */
static int trie_leaf_remove(struct trie *t, t_key key) static int trie_leaf_remove(struct trie *t, t_key key)
{ {
t_key cindex; t_key cindex;
...@@ -1503,15 +1507,17 @@ static int trie_leaf_remove(struct trie *t, t_key key) ...@@ -1503,15 +1507,17 @@ static int trie_leaf_remove(struct trie *t, t_key key)
t->revision++; t->revision++;
t->size--; t->size--;
preempt_disable();
tp = NODE_PARENT(n); tp = NODE_PARENT(n);
tnode_free((struct tnode *) n); tnode_free((struct tnode *) n);
if (tp) { if (tp) {
cindex = tkey_extract_bits(key, tp->pos, tp->bits); cindex = tkey_extract_bits(key, tp->pos, tp->bits);
put_child(t, (struct tnode *)tp, cindex, NULL); put_child(t, (struct tnode *)tp, cindex, NULL);
t->trie = trie_rebalance(t, tp); rcu_assign_pointer(t->trie, trie_rebalance(t, tp));
} else } else
t->trie = NULL; rcu_assign_pointer(t->trie, NULL);
preempt_enable();
return 1; return 1;
} }
...@@ -1527,7 +1533,6 @@ fn_trie_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta, ...@@ -1527,7 +1533,6 @@ fn_trie_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
struct fib_alias *fa, *fa_to_delete; struct fib_alias *fa, *fa_to_delete;
struct list_head *fa_head; struct list_head *fa_head;
struct leaf *l; struct leaf *l;
int kill_li = 0;
struct leaf_info *li; struct leaf_info *li;
...@@ -1560,6 +1565,7 @@ fn_trie_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta, ...@@ -1560,6 +1565,7 @@ fn_trie_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
fa_to_delete = NULL; fa_to_delete = NULL;
fa_head = fa->fa_list.prev; fa_head = fa->fa_list.prev;
list_for_each_entry(fa, fa_head, fa_list) { list_for_each_entry(fa, fa_head, fa_list) {
struct fib_info *fi = fa->fa_info; struct fib_info *fi = fa->fa_info;
...@@ -1587,18 +1593,12 @@ fn_trie_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta, ...@@ -1587,18 +1593,12 @@ fn_trie_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
l = fib_find_node(t, key); l = fib_find_node(t, key);
li = find_leaf_info(&l->list, plen); li = find_leaf_info(&l->list, plen);
write_lock_bh(&fib_lock); list_del_rcu(&fa->fa_list);
list_del(&fa->fa_list);
if (list_empty(fa_head)) { if (list_empty(fa_head)) {
hlist_del(&li->hlist); hlist_del_rcu(&li->hlist);
kill_li = 1;
}
write_unlock_bh(&fib_lock);
if (kill_li)
free_leaf_info(li); free_leaf_info(li);
}
if (hlist_empty(&l->list)) if (hlist_empty(&l->list))
trie_leaf_remove(t, key); trie_leaf_remove(t, key);
...@@ -1606,7 +1606,8 @@ fn_trie_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta, ...@@ -1606,7 +1606,8 @@ fn_trie_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
if (fa->fa_state & FA_S_ACCESSED) if (fa->fa_state & FA_S_ACCESSED)
rt_cache_flush(-1); rt_cache_flush(-1);
fn_free_alias(fa); fib_release_info(fa->fa_info);
alias_free_mem_rcu(fa);
return 0; return 0;
} }
...@@ -1618,12 +1619,10 @@ static int trie_flush_list(struct trie *t, struct list_head *head) ...@@ -1618,12 +1619,10 @@ static int trie_flush_list(struct trie *t, struct list_head *head)
list_for_each_entry_safe(fa, fa_node, head, fa_list) { list_for_each_entry_safe(fa, fa_node, head, fa_list) {
struct fib_info *fi = fa->fa_info; struct fib_info *fi = fa->fa_info;
if (fi && (fi->fib_flags&RTNH_F_DEAD)) { if (fi && (fi->fib_flags & RTNH_F_DEAD)) {
write_lock_bh(&fib_lock); list_del_rcu(&fa->fa_list);
list_del(&fa->fa_list); fib_release_info(fa->fa_info);
write_unlock_bh(&fib_lock); alias_free_mem_rcu(fa);
fn_free_alias(fa);
found++; found++;
} }
} }
...@@ -1641,30 +1640,30 @@ static int trie_flush_leaf(struct trie *t, struct leaf *l) ...@@ -1641,30 +1640,30 @@ static int trie_flush_leaf(struct trie *t, struct leaf *l)
found += trie_flush_list(t, &li->falh); found += trie_flush_list(t, &li->falh);
if (list_empty(&li->falh)) { if (list_empty(&li->falh)) {
write_lock_bh(&fib_lock); hlist_del_rcu(&li->hlist);
hlist_del(&li->hlist);
write_unlock_bh(&fib_lock);
free_leaf_info(li); free_leaf_info(li);
} }
} }
return found; return found;
} }
/* rcu_read_lock needs to be hold by caller from readside */
static struct leaf *nextleaf(struct trie *t, struct leaf *thisleaf) static struct leaf *nextleaf(struct trie *t, struct leaf *thisleaf)
{ {
struct node *c = (struct node *) thisleaf; struct node *c = (struct node *) thisleaf;
struct tnode *p; struct tnode *p;
int idx; int idx;
struct node *trie = rcu_dereference(t->trie);
if (c == NULL) { if (c == NULL) {
if (t->trie == NULL) if (trie == NULL)
return NULL; return NULL;
if (IS_LEAF(t->trie)) /* trie w. just a leaf */ if (IS_LEAF(trie)) /* trie w. just a leaf */
return (struct leaf *) t->trie; return (struct leaf *) trie;
p = (struct tnode*) t->trie; /* Start */ p = (struct tnode*) trie; /* Start */
} else } else
p = (struct tnode *) NODE_PARENT(c); p = (struct tnode *) NODE_PARENT(c);
...@@ -1679,23 +1678,26 @@ static struct leaf *nextleaf(struct trie *t, struct leaf *thisleaf) ...@@ -1679,23 +1678,26 @@ static struct leaf *nextleaf(struct trie *t, struct leaf *thisleaf)
last = 1 << p->bits; last = 1 << p->bits;
for (idx = pos; idx < last ; idx++) { for (idx = pos; idx < last ; idx++) {
if (!p->child[idx]) c = rcu_dereference(p->child[idx]);
if (!c)
continue; continue;
/* Decend if tnode */ /* Decend if tnode */
while (IS_TNODE(p->child[idx])) { while (IS_TNODE(c)) {
p = (struct tnode*) p->child[idx]; p = (struct tnode *) c;
idx = 0; idx = 0;
/* Rightmost non-NULL branch */ /* Rightmost non-NULL branch */
if (p && IS_TNODE(p)) if (p && IS_TNODE(p))
while (p->child[idx] == NULL && idx < (1 << p->bits)) idx++; while (!(c = rcu_dereference(p->child[idx]))
&& idx < (1<<p->bits)) idx++;
/* Done with this tnode? */ /* Done with this tnode? */
if (idx >= (1 << p->bits) || p->child[idx] == NULL) if (idx >= (1 << p->bits) || !c)
goto up; goto up;
} }
return (struct leaf*) p->child[idx]; return (struct leaf *) c;
} }
up: up:
/* No more children go up one step */ /* No more children go up one step */
...@@ -1713,6 +1715,7 @@ static int fn_trie_flush(struct fib_table *tb) ...@@ -1713,6 +1715,7 @@ static int fn_trie_flush(struct fib_table *tb)
t->revision++; t->revision++;
rcu_read_lock();
for (h = 0; (l = nextleaf(t, l)) != NULL; h++) { for (h = 0; (l = nextleaf(t, l)) != NULL; h++) {
found += trie_flush_leaf(t, l); found += trie_flush_leaf(t, l);
...@@ -1720,6 +1723,7 @@ static int fn_trie_flush(struct fib_table *tb) ...@@ -1720,6 +1723,7 @@ static int fn_trie_flush(struct fib_table *tb)
trie_leaf_remove(t, ll->key); trie_leaf_remove(t, ll->key);
ll = l; ll = l;
} }
rcu_read_unlock();
if (ll && hlist_empty(&ll->list)) if (ll && hlist_empty(&ll->list))
trie_leaf_remove(t, ll->key); trie_leaf_remove(t, ll->key);
...@@ -1745,7 +1749,7 @@ fn_trie_select_default(struct fib_table *tb, const struct flowi *flp, struct fib ...@@ -1745,7 +1749,7 @@ fn_trie_select_default(struct fib_table *tb, const struct flowi *flp, struct fib
last_resort = NULL; last_resort = NULL;
order = -1; order = -1;
read_lock(&fib_lock); rcu_read_lock();
l = fib_find_node(t, 0); l = fib_find_node(t, 0);
if (!l) if (!l)
...@@ -1758,7 +1762,7 @@ fn_trie_select_default(struct fib_table *tb, const struct flowi *flp, struct fib ...@@ -1758,7 +1762,7 @@ fn_trie_select_default(struct fib_table *tb, const struct flowi *flp, struct fib
if (list_empty(fa_head)) if (list_empty(fa_head))
goto out; goto out;
list_for_each_entry(fa, fa_head, fa_list) { list_for_each_entry_rcu(fa, fa_head, fa_list) {
struct fib_info *next_fi = fa->fa_info; struct fib_info *next_fi = fa->fa_info;
if (fa->fa_scope != res->scope || if (fa->fa_scope != res->scope ||
...@@ -1809,7 +1813,7 @@ fn_trie_select_default(struct fib_table *tb, const struct flowi *flp, struct fib ...@@ -1809,7 +1813,7 @@ fn_trie_select_default(struct fib_table *tb, const struct flowi *flp, struct fib
} }
trie_last_dflt = last_idx; trie_last_dflt = last_idx;
out:; out:;
read_unlock(&fib_lock); rcu_read_unlock();
} }
static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah, struct fib_table *tb, static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah, struct fib_table *tb,
...@@ -1823,7 +1827,9 @@ static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah, struct fi ...@@ -1823,7 +1827,9 @@ static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah, struct fi
s_i = cb->args[3]; s_i = cb->args[3];
i = 0; i = 0;
list_for_each_entry(fa, fah, fa_list) { /* rcu_read_lock is hold by caller */
list_for_each_entry_rcu(fa, fah, fa_list) {
if (i < s_i) { if (i < s_i) {
i++; i++;
continue; continue;
...@@ -1898,7 +1904,7 @@ static int fn_trie_dump(struct fib_table *tb, struct sk_buff *skb, struct netlin ...@@ -1898,7 +1904,7 @@ static int fn_trie_dump(struct fib_table *tb, struct sk_buff *skb, struct netlin
s_m = cb->args[1]; s_m = cb->args[1];
read_lock(&fib_lock); rcu_read_lock();
for (m = 0; m <= 32; m++) { for (m = 0; m <= 32; m++) {
if (m < s_m) if (m < s_m)
continue; continue;
...@@ -1911,11 +1917,11 @@ static int fn_trie_dump(struct fib_table *tb, struct sk_buff *skb, struct netlin ...@@ -1911,11 +1917,11 @@ static int fn_trie_dump(struct fib_table *tb, struct sk_buff *skb, struct netlin
goto out; goto out;
} }
} }
read_unlock(&fib_lock); rcu_read_unlock();
cb->args[1] = m; cb->args[1] = m;
return skb->len; return skb->len;
out: out:
read_unlock(&fib_lock); rcu_read_unlock();
return -1; return -1;
} }
...@@ -2016,7 +2022,7 @@ static void printnode_seq(struct seq_file *seq, int indent, struct node *n, ...@@ -2016,7 +2022,7 @@ static void printnode_seq(struct seq_file *seq, int indent, struct node *n,
putspace_seq(seq, indent+2); putspace_seq(seq, indent+2);
seq_printf(seq, "{/%d...dumping}\n", i); seq_printf(seq, "{/%d...dumping}\n", i);
list_for_each_entry(fa, fa_head, fa_list) { list_for_each_entry_rcu(fa, fa_head, fa_list) {
putspace_seq(seq, indent+2); putspace_seq(seq, indent+2);
if (fa->fa_info == NULL) { if (fa->fa_info == NULL) {
seq_printf(seq, "Error fa_info=NULL\n"); seq_printf(seq, "Error fa_info=NULL\n");
...@@ -2056,28 +2062,28 @@ static void printnode_seq(struct seq_file *seq, int indent, struct node *n, ...@@ -2056,28 +2062,28 @@ static void printnode_seq(struct seq_file *seq, int indent, struct node *n,
static void trie_dump_seq(struct seq_file *seq, struct trie *t) static void trie_dump_seq(struct seq_file *seq, struct trie *t)
{ {
struct node *n = t->trie; struct node *n;
int cindex = 0; int cindex = 0;
int indent = 1; int indent = 1;
int pend = 0; int pend = 0;
int depth = 0; int depth = 0;
struct tnode *tn; struct tnode *tn;
read_lock(&fib_lock); rcu_read_lock();
n = rcu_dereference(t->trie);
seq_printf(seq, "------ trie_dump of t=%p ------\n", t); seq_printf(seq, "------ trie_dump of t=%p ------\n", t);
if (!n) { if (!n) {
seq_printf(seq, "------ trie is empty\n"); seq_printf(seq, "------ trie is empty\n");
read_unlock(&fib_lock); rcu_read_unlock();
return; return;
} }
printnode_seq(seq, indent, n, pend, cindex, 0); printnode_seq(seq, indent, n, pend, cindex, 0);
if (!IS_TNODE(n)) { if (!IS_TNODE(n)) {
read_unlock(&fib_lock); rcu_read_unlock();
return; return;
} }
...@@ -2088,26 +2094,32 @@ static void trie_dump_seq(struct seq_file *seq, struct trie *t) ...@@ -2088,26 +2094,32 @@ static void trie_dump_seq(struct seq_file *seq, struct trie *t)
depth++; depth++;
while (tn && cindex < (1 << tn->bits)) { while (tn && cindex < (1 << tn->bits)) {
if (tn->child[cindex]) { struct node *child = rcu_dereference(tn->child[cindex]);
if (!child)
cindex++;
else {
/* Got a child */ /* Got a child */
printnode_seq(seq, indent, child, pend,
cindex, tn->bits);
printnode_seq(seq, indent, tn->child[cindex], pend, cindex, tn->bits); if (IS_LEAF(child))
if (IS_LEAF(tn->child[cindex])) {
cindex++; cindex++;
} else {
else {
/* /*
* New tnode. Decend one level * New tnode. Decend one level
*/ */
depth++; depth++;
tn = (struct tnode *)tn->child[cindex]; n = child;
pend = tn->pos + tn->bits; tn = (struct tnode *)n;
putspace_seq(seq, indent); seq_printf(seq, "\\--\n"); pend = tn->pos+tn->bits;
putspace_seq(seq, indent);
seq_printf(seq, "\\--\n");
indent += 3; indent += 3;
cindex = 0; cindex = 0;
} }
} else }
cindex++;
/* /*
* Test if we are done * Test if we are done
...@@ -2132,8 +2144,7 @@ static void trie_dump_seq(struct seq_file *seq, struct trie *t) ...@@ -2132,8 +2144,7 @@ static void trie_dump_seq(struct seq_file *seq, struct trie *t)
depth--; depth--;
} }
} }
rcu_read_unlock();
read_unlock(&fib_lock);
} }
static struct trie_stat *trie_stat_new(void) static struct trie_stat *trie_stat_new(void)
...@@ -2159,7 +2170,7 @@ static struct trie_stat *trie_stat_new(void) ...@@ -2159,7 +2170,7 @@ static struct trie_stat *trie_stat_new(void)
static struct trie_stat *trie_collect_stats(struct trie *t) static struct trie_stat *trie_collect_stats(struct trie *t)
{ {
struct node *n = t->trie; struct node *n;
struct trie_stat *s = trie_stat_new(); struct trie_stat *s = trie_stat_new();
int cindex = 0; int cindex = 0;
int pend = 0; int pend = 0;
...@@ -2167,11 +2178,13 @@ static struct trie_stat *trie_collect_stats(struct trie *t) ...@@ -2167,11 +2178,13 @@ static struct trie_stat *trie_collect_stats(struct trie *t)
if (!s) if (!s)
return NULL; return NULL;
rcu_read_lock();
n = rcu_dereference(t->trie);
if (!n) if (!n)
return s; return s;
read_lock(&fib_lock);
if (IS_TNODE(n)) { if (IS_TNODE(n)) {
struct tnode *tn = (struct tnode *)n; struct tnode *tn = (struct tnode *)n;
pend = tn->pos+tn->bits; pend = tn->pos+tn->bits;
...@@ -2179,7 +2192,9 @@ static struct trie_stat *trie_collect_stats(struct trie *t) ...@@ -2179,7 +2192,9 @@ static struct trie_stat *trie_collect_stats(struct trie *t)
depth++; depth++;
while (tn && cindex < (1 << tn->bits)) { while (tn && cindex < (1 << tn->bits)) {
if (tn->child[cindex]) { struct node *ch = rcu_dereference(tn->child[cindex]);
if (ch) {
/* Got a child */ /* Got a child */
if (IS_LEAF(tn->child[cindex])) { if (IS_LEAF(tn->child[cindex])) {
...@@ -2199,7 +2214,7 @@ static struct trie_stat *trie_collect_stats(struct trie *t) ...@@ -2199,7 +2214,7 @@ static struct trie_stat *trie_collect_stats(struct trie *t)
s->nodesizes[tn->bits]++; s->nodesizes[tn->bits]++;
depth++; depth++;
n = tn->child[cindex]; n = ch;
tn = (struct tnode *)n; tn = (struct tnode *)n;
pend = tn->pos+tn->bits; pend = tn->pos+tn->bits;
...@@ -2236,7 +2251,7 @@ static struct trie_stat *trie_collect_stats(struct trie *t) ...@@ -2236,7 +2251,7 @@ static struct trie_stat *trie_collect_stats(struct trie *t)
} }
} }
read_unlock(&fib_lock); rcu_read_unlock();
return s; return s;
} }
......
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