diff options
| -rw-r--r-- | net/ipv4/fib_trie.c | 177 |
1 files changed, 145 insertions, 32 deletions
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 9038b914b4b1..4be234c7d8c3 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -43,7 +43,7 @@ * 2 of the License, or (at your option) any later version. */ -#define VERSION "0.324" +#define VERSION "0.325" #include <linux/config.h> #include <asm/uaccess.h> @@ -136,6 +136,7 @@ struct trie_use_stats { unsigned int semantic_match_passed; unsigned int semantic_match_miss; unsigned int null_node_hit; + unsigned int resize_node_skipped; }; #endif @@ -164,8 +165,8 @@ static void put_child(struct trie *t, struct tnode *tn, int i, struct node *n); static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int wasfull); static int tnode_child_length(struct tnode *tn); static struct node *resize(struct trie *t, struct tnode *tn); -static struct tnode *inflate(struct trie *t, struct tnode *tn); -static struct tnode *halve(struct trie *t, struct tnode *tn); +static struct tnode *inflate(struct trie *t, struct tnode *tn, int *err); +static struct tnode *halve(struct trie *t, struct tnode *tn, int *err); static void tnode_free(struct tnode *tn); static void trie_dump_seq(struct seq_file *seq, struct trie *t); extern struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio); @@ -481,6 +482,7 @@ static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int w static struct node *resize(struct trie *t, struct tnode *tn) { int i; + int err = 0; if (!tn) return NULL; @@ -577,12 +579,20 @@ static struct node *resize(struct trie *t, struct tnode *tn) */ check_tnode(tn); - + + err = 0; while ((tn->full_children > 0 && 50 * (tn->full_children + tnode_child_length(tn) - tn->empty_children) >= inflate_threshold * tnode_child_length(tn))) { - tn = inflate(t, tn); + tn = inflate(t, tn, &err); + + if(err) { +#ifdef CONFIG_IP_FIB_TRIE_STATS + t->stats.resize_node_skipped++; +#endif + break; + } } check_tnode(tn); @@ -591,11 +601,22 @@ static struct node *resize(struct trie *t, struct tnode *tn) * Halve as long as the number of empty children in this * node is above threshold. */ + + err = 0; while (tn->bits > 1 && 100 * (tnode_child_length(tn) - tn->empty_children) < - halve_threshold * tnode_child_length(tn)) + halve_threshold * tnode_child_length(tn)) { + + tn = halve(t, tn, &err); + + if(err) { +#ifdef CONFIG_IP_FIB_TRIE_STATS + t->stats.resize_node_skipped++; +#endif + break; + } + } - tn = halve(t, tn); /* Only one child remains */ @@ -620,7 +641,7 @@ static struct node *resize(struct trie *t, struct tnode *tn) return (struct node *) tn; } -static struct tnode *inflate(struct trie *t, struct tnode *tn) +static struct tnode *inflate(struct trie *t, struct tnode *tn, int *err) { struct tnode *inode; struct tnode *oldtnode = tn; @@ -632,8 +653,63 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn) tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits + 1); - if (!tn) - trie_bug("tnode_new failed"); + if (!tn) { + *err = -ENOMEM; + return oldtnode; + } + + /* + * Preallocate and store tnodes before the actual work so we + * don't get into an inconsistent state if memory allocation + * fails. In case of failure we return the oldnode and inflate + * of tnode is ignored. + */ + + for(i = 0; i < olen; i++) { + struct tnode *inode = (struct tnode *) tnode_get_child(oldtnode, i); + + if (inode && + IS_TNODE(inode) && + inode->pos == oldtnode->pos + oldtnode->bits && + inode->bits > 1) { + struct tnode *left, *right; + + t_key m = TKEY_GET_MASK(inode->pos, 1); + + left = tnode_new(inode->key&(~m), inode->pos + 1, + inode->bits - 1); + + if(!left) { + *err = -ENOMEM; + break; + } + + right = tnode_new(inode->key|m, inode->pos + 1, + inode->bits - 1); + + if(!right) { + *err = -ENOMEM; + break; + } + + put_child(t, tn, 2*i, (struct node *) left); + put_child(t, tn, 2*i+1, (struct node *) right); + } + } + + if(*err) { + int size = tnode_child_length(tn); + int j; + + for(j = 0; j < size; j++) + if( tn->child[j]) + tnode_free((struct tnode *)tn->child[j]); + + tnode_free(tn); + + *err = -ENOMEM; + return oldtnode; + } for(i = 0; i < olen; i++) { struct node *node = tnode_get_child(oldtnode, i); @@ -646,7 +722,7 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn) if(IS_LEAF(node) || ((struct tnode *) node)->pos > tn->pos + tn->bits - 1) { - if(tkey_extract_bits(node->key, tn->pos + tn->bits - 1, + if(tkey_extract_bits(node->key, oldtnode->pos + oldtnode->bits, 1) == 0) put_child(t, tn, 2*i, node); else @@ -686,27 +762,22 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn) * the position (inode->pos) */ - t_key m = TKEY_GET_MASK(inode->pos, 1); - /* Use the old key, but set the new significant * bit to zero. */ - left = tnode_new(inode->key&(~m), inode->pos + 1, - inode->bits - 1); - if(!left) - trie_bug("tnode_new failed"); - - - /* Use the old key, but set the new significant - * bit to one. - */ - right = tnode_new(inode->key|m, inode->pos + 1, - inode->bits - 1); + left = (struct tnode *) tnode_get_child(tn, 2*i); + put_child(t, tn, 2*i, NULL); + + if(!left) + BUG(); + + right = (struct tnode *) tnode_get_child(tn, 2*i+1); + put_child(t, tn, 2*i+1, NULL); + + if(!right) + BUG(); - if(!right) - trie_bug("tnode_new failed"); - size = tnode_child_length(left); for(j = 0; j < size; j++) { put_child(t, left, j, inode->child[j]); @@ -722,7 +793,7 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn) return tn; } -static struct tnode *halve(struct trie *t, struct tnode *tn) +static struct tnode *halve(struct trie *t, struct tnode *tn, int *err) { struct tnode *oldtnode = tn; struct node *left, *right; @@ -733,8 +804,48 @@ static struct tnode *halve(struct trie *t, struct tnode *tn) tn=tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits - 1); - if(!tn) - trie_bug("tnode_new failed"); + if (!tn) { + *err = -ENOMEM; + return oldtnode; + } + + /* + * Preallocate and store tnodes before the actual work so we + * don't get into an inconsistent state if memory allocation + * fails. In case of failure we return the oldnode and halve + * of tnode is ignored. + */ + + for(i = 0; i < olen; i += 2) { + left = tnode_get_child(oldtnode, i); + right = tnode_get_child(oldtnode, i+1); + + /* Two nonempty children */ + if( left && right) { + struct tnode *newBinNode = + tnode_new(left->key, tn->pos + tn->bits, 1); + + if(!newBinNode) { + *err = -ENOMEM; + break; + } + put_child(t, tn, i/2, (struct node *)newBinNode); + } + } + + if(*err) { + int size = tnode_child_length(tn); + int j; + + for(j = 0; j < size; j++) + if( tn->child[j]) + tnode_free((struct tnode *)tn->child[j]); + + tnode_free(tn); + + *err = -ENOMEM; + return oldtnode; + } for(i = 0; i < olen; i += 2) { left = tnode_get_child(oldtnode, i); @@ -751,10 +862,11 @@ static struct tnode *halve(struct trie *t, struct tnode *tn) /* Two nonempty children */ else { struct tnode *newBinNode = - tnode_new(left->key, tn->pos + tn->bits, 1); + (struct tnode *) tnode_get_child(tn, i/2); + put_child(t, tn, i/2, NULL); if(!newBinNode) - trie_bug("tnode_new failed"); + BUG(); put_child(t, newBinNode, 0, left); put_child(t, newBinNode, 1, right); @@ -2322,6 +2434,7 @@ static void collect_and_show(struct trie *t, struct seq_file *seq) seq_printf(seq,"semantic match passed = %d\n", t->stats.semantic_match_passed); seq_printf(seq,"semantic match miss = %d\n", t->stats.semantic_match_miss); seq_printf(seq,"null node hit= %d\n", t->stats.null_node_hit); + seq_printf(seq,"skipped node resize = %d\n", t->stats.resize_node_skipped); #ifdef CLEAR_STATS memset(&(t->stats), 0, sizeof(t->stats)); #endif |