[IPV4]: fib_trie resize break

The patch below adds break condition for the resize operations. If
we don't achieve the desired fill factor a warning is printed. Trie
should still be operational but new thresholds should be considered.

Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index e2b39fdd6a0453e30cbeefa15909a104e6cdc857..5d2b43d9f8fcdc0c1ff3fe14b463656bab0424ff 100644 (file)
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -50,7 +50,7 @@
  *             Patrick McHardy <kaber@trash.net>
  */
 
-#define VERSION "0.407"
+#define VERSION "0.408"
 
 #include <asm/uaccess.h>
 #include <asm/system.h>
@@ -458,6 +458,7 @@ static struct node *resize(struct trie *t, struct tnode *tn)
        struct tnode *old_tn;
        int inflate_threshold_use;
        int halve_threshold_use;
+       int max_resize;
 
        if (!tn)
                return NULL;
@@ -558,7 +559,8 @@ static struct node *resize(struct trie *t, struct tnode *tn)
                inflate_threshold_use = inflate_threshold;
 
        err = 0;
-       while ((tn->full_children > 0 &&
+       max_resize = 10;
+       while ((tn->full_children > 0 &&  max_resize-- &&
               50 * (tn->full_children + tnode_child_length(tn) - tn->empty_children) >=
                                inflate_threshold_use * tnode_child_length(tn))) {
 
@@ -573,6 +575,15 @@ static struct node *resize(struct trie *t, struct tnode *tn)
                }
        }
 
+       if (max_resize < 0) {
+               if (!tn->parent)
+                       printk(KERN_WARNING "Fix inflate_threshold_root. Now=%d size=%d bits\n",
+                              inflate_threshold_root, tn->bits);
+               else
+                       printk(KERN_WARNING "Fix inflate_threshold. Now=%d size=%d bits\n",
+                              inflate_threshold, tn->bits);
+       }
+
        check_tnode(tn);
 
        /*
@@ -589,7 +600,8 @@ static struct node *resize(struct trie *t, struct tnode *tn)
                halve_threshold_use = halve_threshold;
 
        err = 0;
-       while (tn->bits > 1 &&
+       max_resize = 10;
+       while (tn->bits > 1 &&  max_resize-- &&
               100 * (tnode_child_length(tn) - tn->empty_children) <
               halve_threshold_use * tnode_child_length(tn)) {
 
@@ -604,6 +616,14 @@ static struct node *resize(struct trie *t, struct tnode *tn)
                }
        }
 
+       if (max_resize < 0) {
+               if (!tn->parent)
+                       printk(KERN_WARNING "Fix halve_threshold_root. Now=%d size=%d bits\n",
+                              halve_threshold_root, tn->bits);
+               else
+                       printk(KERN_WARNING "Fix halve_threshold. Now=%d size=%d bits\n",
+                              halve_threshold, tn->bits);
+       }
 
        /* Only one child remains */
        if (tn->empty_children == tnode_child_length(tn) - 1)