[PATCH 3/4] fib_trie: print statistics for multiple tables

Stephen Hemminger
2008-02-13T01:03:56Z

[-- Attachment #1: fib-trie-tables.patch --]
[-- Type: text/plain, Size: 8538 bytes --]

Make /proc/net/fib_trie and /proc/net/fib_triestat handle
multiple (alternate) route tables. Need hliist_for_each_entry_continue_rcu
as well.

Notes:
* this usage of seq_file doesn't need/want SEQ_START_TOKEN
* add hlist_for_each_entry_continue_rcu since it needs it

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
---
include/linux/list.h | 13 ++++
net/ipv4/fib_trie.c | 186 ++++++++++++++++++++++++++++----------------------
2 files changed, 117 insertions(+), 82 deletions(-)

--- a/include/linux/list.h 2008-02-12 14:46:49.000000000 -0800
+++ b/include/linux/list.h 2008-02-12 15:09:17.000000000 -0800
@@ -991,6 +991,19 @@ static inline void hlist_add_after_rcu(s
({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
pos = pos->next)

+
+/**
+ * hlist_for_each_entry_continue_rcu - iterate over rcu hlist after current point
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct hlist_node to use as a loop cursor.
+ * @member: the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_continue_rcu(tpos, pos, member) \
+ for (pos = (pos)->next; \
+ rcu_dereference(pos) && ({ prefetch(pos->next); 1;}) && \
+ ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+ pos = pos->next)
+
#else
#warning "don't include kernel headers in userspace"
#endif /* __KERNEL__ */
--- a/net/ipv4/fib_trie.c 2008-02-12 14:56:58.000000000 -0800
+++ b/net/ipv4/fib_trie.c 2008-02-12 15:09:46.000000000 -0800
@@ -2026,14 +2026,13 @@ struct fib_table *fib_hash_table(u32 id)
/* Depth first Trie walk iterator */
struct fib_trie_iter {
struct seq_net_private p;
- struct trie *trie_local, *trie_main;
+ struct fib_table *tb;
struct tnode *tnode;
- struct trie *trie;
unsigned index;
unsigned depth;
};

-static struct node *fib_trie_get_next(struct fib_trie_iter *iter)
+static struct node *trie_get_next(struct fib_trie_iter *iter)
{
struct tnode *tn = iter->tnode;
unsigned cindex = iter->index;
@@ -2078,37 +2077,33 @@ rescan:
return NULL;
}

-static struct node *fib_trie_get_first(struct fib_trie_iter *iter,
- struct trie *t)
+static struct node *trie_get_first(struct fib_trie_iter *iter, struct fib_table *tb)
{
- struct node *n ;
+ struct trie *t = (struct trie *) tb->tb_data;
+ struct node *n;

+ iter->tb = tb;
if (!t)
return NULL;

n = rcu_dereference(t->trie);
-
- if (!iter)
+ if (!n)
return NULL;

- if (n) {
- if (IS_TNODE(n)) {
- iter->tnode = (struct tnode *) n;
- iter->trie = t;
- iter->index = 0;
- iter->depth = 1;
- } else {
- iter->tnode = NULL;
- iter->trie = t;
- iter->index = 0;
- iter->depth = 0;
- }
- return n;
+ if (IS_TNODE(n)) {
+ iter->tnode = (struct tnode *) n;
+ iter->index = 0;
+ iter->depth = 1;
+ } else {
+ iter->tnode = NULL;
+ iter->index = 0;
+ iter->depth = 0;
}
- return NULL;
+
+ return n;
}

-static void trie_collect_stats(struct trie *t, struct trie_stat *s)
+static void trie_collect_stats(struct fib_table *tb, struct trie_stat *s)
{
struct node *n;
struct fib_trie_iter iter;
@@ -2116,8 +2111,7 @@ static void trie_collect_stats(struct tr
memset(s, 0, sizeof(*s));

rcu_read_lock();
- for (n = fib_trie_get_first(&iter, t); n;
- n = fib_trie_get_next(&iter)) {
+ for (n = trie_get_first(&iter, tb); n; n = trie_get_next(&iter)) {
if (IS_LEAF(n)) {
struct leaf *l = (struct leaf *)n;
struct leaf_info *li;
@@ -2206,36 +2200,53 @@ static void trie_show_usage(struct seq_f
}
#endif /* CONFIG_IP_FIB_TRIE_STATS */

-static void fib_trie_show(struct seq_file *seq, const char *name,
- struct trie *trie)
+static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
+{
+ if (tb->tb_id == RT_TABLE_LOCAL)
+ seq_puts(seq, "Local:\n");
+ else if (tb->tb_id == RT_TABLE_MAIN)
+ seq_puts(seq, "Main:\n");
+ else
+ seq_printf(seq, "Id %d:\n", tb->tb_id);
+}
+
+static void fib_trie_show(struct seq_file *seq, struct fib_table *tb)
{
+ struct trie *t = (struct trie *) tb->tb_data;
struct trie_stat stat;

- trie_collect_stats(trie, &stat);
- seq_printf(seq, "%s:\n", name);
+ if (!t)
+ return;
+
+ fib_table_print(seq, tb);
+
+ trie_collect_stats(tb, &stat);
trie_show_stats(seq, &stat);
#ifdef CONFIG_IP_FIB_TRIE_STATS
- trie_show_usage(seq, &trie->stats);
+ trie_show_usage(seq, &t->stats);
#endif
}

static int fib_triestat_seq_show(struct seq_file *seq, void *v)
{
struct net *net = (struct net *)seq->private;
- struct fib_table *tb;
+ unsigned int h;

seq_printf(seq,
"Basic info: size of leaf:"
" %Zd bytes, size of tnode: %Zd bytes.\n",
sizeof(struct leaf), sizeof(struct tnode));

- tb = fib_get_table(net, RT_TABLE_LOCAL);
- if (tb)
- fib_trie_show(seq, "Local", (struct trie *) tb->tb_data);
-
- tb = fib_get_table(net, RT_TABLE_MAIN);
- if (tb)
- fib_trie_show(seq, "Main", (struct trie *) tb->tb_data);
+ for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
+ struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+ struct hlist_node *node;
+ struct fib_table *tb;
+
+ hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
+ fib_trie_show(seq, tb);
+
+ }
+ }

return 0;
}
@@ -2271,23 +2282,29 @@ static const struct file_operations fib_
.release = fib_triestat_seq_release,
};

-static struct node *fib_trie_get_idx(struct fib_trie_iter *iter,
- loff_t pos)
+static struct node *fib_trie_get_idx(struct fib_trie_iter *iter, loff_t pos)
{
+ struct net *net = iter->p.net;
loff_t idx = 0;
- struct node *n;
+ unsigned int h;

- for (n = fib_trie_get_first(iter, iter->trie_local);
- n; ++idx, n = fib_trie_get_next(iter)) {
- if (pos == idx)
- return n;
- }
+ for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
+ struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+ struct hlist_node *node;
+ struct fib_table *tb;

- for (n = fib_trie_get_first(iter, iter->trie_main);
- n; ++idx, n = fib_trie_get_next(iter)) {
- if (pos == idx)
- return n;
+ hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
+ struct node *n;
+
+ for (n = trie_get_first(iter, tb);
+ n; n = trie_get_next(iter))
+ if (pos == idx++) {
+ iter->tb = tb;
+ return n;
+ }
+ }
}
+
return NULL;
}

@@ -2295,43 +2312,49 @@ static void *fib_trie_seq_start(struct s
__acquires(RCU)
{
struct fib_trie_iter *iter = seq->private;
- struct fib_table *tb;

- if (!iter->trie_local) {
- tb = fib_get_table(iter->p.net, RT_TABLE_LOCAL);
- if (tb)
- iter->trie_local = (struct trie *) tb->tb_data;
- }
- if (!iter->trie_main) {
- tb = fib_get_table(iter->p.net, RT_TABLE_MAIN);
- if (tb)
- iter->trie_main = (struct trie *) tb->tb_data;
- }
rcu_read_lock();
- if (*pos == 0)
- return SEQ_START_TOKEN;
- return fib_trie_get_idx(iter, *pos - 1);
+ return fib_trie_get_idx(iter, *pos);
}

static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct fib_trie_iter *iter = seq->private;
- void *l = v;
+ struct net *net = iter->p.net;
+ struct fib_table *tb = iter->tb;
+ struct hlist_node *tb_node;
+ unsigned int h;
+ struct node *n;

++*pos;
- if (v == SEQ_START_TOKEN)
- return fib_trie_get_idx(iter, 0);
+ n = trie_get_next(iter);
+ if (n)
+ return n;

- v = fib_trie_get_next(iter);
- BUG_ON(v == l);
- if (v)
- return v;
-
- /* continue scan in next trie */
- if (iter->trie == iter->trie_local)
- return fib_trie_get_first(iter, iter->trie_main);
+ /* walk rest of this hash chain */
+ h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
+ tb_node = &tb->tb_hlist;
+ hlist_for_each_entry_continue_rcu(tb, tb_node, tb_hlist) {
+ n = trie_get_first(iter, tb);
+ if (n)
+ goto found;
+ }
+
+ /* new hash chain */
+ while (++h < FIB_TABLE_HASHSZ) {
+ struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+ hlist_for_each_entry_rcu(tb, tb_node, head, tb_hlist) {
+ n = trie_get_first(iter, tb);
+ if (n)
+ goto found;
+ }
+ }

return NULL;
+
+found:
+ iter->tb = tb;
+ return n;
}

static void fib_trie_seq_stop(struct seq_file *seq, void *v)
@@ -2399,15 +2422,8 @@ static int fib_trie_seq_show(struct seq_
const struct fib_trie_iter *iter = seq->private;
struct node *n = v;

- if (v == SEQ_START_TOKEN)
- return 0;
-
- if (!node_parent_rcu(n)) {
- if (iter->trie == iter->trie_local)
- seq_puts(seq, "<local>:\n");
- else
- seq_puts(seq, " :\n");
- }
+ if (!node_parent_rcu(n))
+ fib_table_print(seq, iter->tb);

if (IS_TNODE(n)) {
struct tnode *tn = (struct tnode *) n;