[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>

1 files changed, 23 insertions, 3 deletions

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index e2b39fdd6a04..5d2b43d9f8fc 100644
--- 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)