[PATCH 2.6.24] fib_trie: apply fixes from fib_hash

[PATCH 2.6.24] fib_trie: apply fixes from fib_hash

[Julian Anastasov]

	Update fib_trie with some fib_hash fixes:
- check for duplicate alternative routes for prefix+tos+priority when
replacing route
- properly insert by matching tos together with priority
- fix alias walking to use list_for_each_entry_continue for insertion
and deletion when fa_head is not NULL
- copy state from fa to new_fa on replace (not a problem for now)

Signed-off-by: Julian Anastasov <ja@ssi.bg>
---

	Not tested, someone please check the findings

--- linux-2.6.24/net/ipv4/fib_trie.c_orig	2008-01-25 10:45:06.000000000 +0200
+++ linux-2.6.24/net/ipv4/fib_trie.c	2008-01-26 03:54:33.000000000 +0200
@@ -1203,20 +1203,42 @@ static int fn_trie_insert(struct fib_tab
 	 * and we need to allocate a new one of those as well.
 	 */
 
-	if (fa && fa->fa_info->fib_priority == fi->fib_priority) {
-		struct fib_alias *fa_orig;
+	if (fa && fa->fa_tos == tos &&
+	    fa->fa_info->fib_priority == fi->fib_priority) {
+		struct fib_alias *fa_first, *fa_match;
 
 		err = -EEXIST;
 		if (cfg->fc_nlflags & NLM_F_EXCL)
 			goto out;
 
+		/* We have 2 goals:
+		 * 1. Find exact match for type, scope, fib_info to avoid
+		 * duplicate routes
+		 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
+		 */
+		fa_match = NULL;
+		fa_first = fa;
+		fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
+		list_for_each_entry_continue(fa, fa_head, fa_list) {
+			if (fa->fa_tos != tos)
+				break;
+			if (fa->fa_info->fib_priority != fi->fib_priority)
+				break;
+			if (fa->fa_type == cfg->fc_type &&
+			    fa->fa_scope == cfg->fc_scope &&
+			    fa->fa_info == fi) {
+				fa_match = fa;
+				break;
+			}
+		}
+
 		if (cfg->fc_nlflags & NLM_F_REPLACE) {
 			struct fib_info *fi_drop;
 			u8 state;
 
-			if (fi->fib_treeref > 1)
+			fa = fa_first;
+			if (fa_match && fa != fa_match)
 				goto out;
-
 			err = -ENOBUFS;
 			new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
 			if (new_fa == NULL)
@@ -1228,7 +1250,7 @@ static int fn_trie_insert(struct fib_tab
 			new_fa->fa_type = cfg->fc_type;
 			new_fa->fa_scope = cfg->fc_scope;
 			state = fa->fa_state;
-			new_fa->fa_state &= ~FA_S_ACCESSED;
+			new_fa->fa_state = state & ~FA_S_ACCESSED;
 
 			list_replace_rcu(&fa->fa_list, &new_fa->fa_list);
 			alias_free_mem_rcu(fa);
@@ -1245,20 +1267,11 @@ static int fn_trie_insert(struct fib_tab
 		 * uses the same scope, type, and nexthop
 		 * information.
 		 */
-		fa_orig = fa;
-		list_for_each_entry(fa, fa_orig->fa_list.prev, fa_list) {
-			if (fa->fa_tos != tos)
-				break;
-			if (fa->fa_info->fib_priority != fi->fib_priority)
-				break;
-			if (fa->fa_type == cfg->fc_type &&
-			    fa->fa_scope == cfg->fc_scope &&
-			    fa->fa_info == fi) {
-				goto out;
-			}
-		}
+		if (fa_match)
+			goto out;
+
 		if (!(cfg->fc_nlflags & NLM_F_APPEND))
-			fa = fa_orig;
+			fa = fa_first;
 	}
 	err = -ENOENT;
 	if (!(cfg->fc_nlflags & NLM_F_CREATE))
@@ -1614,9 +1627,8 @@ static int fn_trie_delete(struct fib_tab
 	pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
 
 	fa_to_delete = NULL;
-	fa_head = fa->fa_list.prev;
-
-	list_for_each_entry(fa, fa_head, fa_list) {
+	fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
+	list_for_each_entry_continue(fa, fa_head, fa_list) {
 		struct fib_info *fi = fa->fa_info;
 
 		if (fa->fa_tos != tos)

Re: [PATCH 2.6.24] fib_trie: apply fixes from fib_hash

[Joonwoo Park]

On Sat, Jan 26, 2008 at 04:40:30AM +0200, Julian Anastasov wrote:
> 
> Signed-off-by: Julian Anastasov <ja@ssi.bg>
> ---
> 
> 	Not tested, someone please check the findings
> 
> --- linux-2.6.24/net/ipv4/fib_trie.c_orig	2008-01-25 10:45:06.000000000 +0200
> +
>  		if (cfg->fc_nlflags & NLM_F_REPLACE) {
>  			struct fib_info *fi_drop;
>  			u8 state;
>  
> -			if (fi->fib_treeref > 1)
> +			fa = fa_first;
> +			if (fa_match && fa != fa_match)
>  				goto out;
> -

Isn't it possible to do this (fib_hash too)?
			if (fa_match) {
				if (fa != fa_match)
					return 0;
				goto out;
			}

Thanks,
Joonwoo

Re: [PATCH 2.6.24] fib_trie: apply fixes from fib_hash

[Joonwoo Park]

2008/1/26, Joonwoo Park <joonwpark81@gmail.com>:
> On Sat, Jan 26, 2008 at 04:40:30AM +0200, Julian Anastasov wrote:
> >
> > Signed-off-by: Julian Anastasov <ja@ssi.bg>
> > ---
> >
> >       Not tested, someone please check the findings
> >
> > --- linux-2.6.24/net/ipv4/fib_trie.c_orig     2008-01-25 10:45:06.000000000 +0200
> > +
> >               if (cfg->fc_nlflags & NLM_F_REPLACE) {
> >                       struct fib_info *fi_drop;
> >                       u8 state;
> >
> > -                     if (fi->fib_treeref > 1)
> > +                     fa = fa_first;
> > +                     if (fa_match && fa != fa_match)
> >                               goto out;
> > -
>
> Isn't it possible to do this (fib_hash too)?
>                        if (fa_match) {
>                                if (fa != fa_match)
Sorry!
                                  if (fa == fa_match)
>                                        return 0;
>                                goto out;
>                        }
>
> Thanks,
> Joonwoo
>

Re: [PATCH 2.6.24] fib_trie: apply fixes from fib_hash

[Julian Anastasov]

	Hello,

On Sat, 26 Jan 2008, Joonwoo Park wrote:

> > >       Not tested, someone please check the findings

	news: simple testing of patched fib_trie seems to work

> > > -                     if (fi->fib_treeref > 1)
> > > +                     fa = fa_first;
> > > +                     if (fa_match && fa != fa_match)
> > >                               goto out;
> > > -
> >
> > Isn't it possible to do this (fib_hash too)?
> >                        if (fa_match) {
> >                                if (fa != fa_match)
> Sorry!
>                                   if (fa == fa_match)
> >                                        return 0;
> >                                goto out;
> >                        }

	I see, your idea is to optimize the case when matched
parameters are same. Considering the used fi is same I don't see
any problems. I'll prepare 2nd version of both patches in
next hours.

Regards

--
Julian Anastasov <ja@ssi.bg>