[PATCH 1/4] rcu_assign_pointer: null check fix

[PATCH 1/4] rcu_assign_pointer: null check fix

[Stephen Hemminger]

[-- Attachment #1: rcu-assign-warn.patch --]
[-- Type: text/plain, Size: 637 bytes --]

Goofed on last change, should avoid barrier only on rcu_assign_pointer(p, NULL)

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
---
 include/linux/rcupdate.h |   13 +++++++------
 1 files changed, 7 insertions(+), 6 deletions(-)

--- a/include/linux/rcupdate.h	2008-02-12 14:46:49.000000000 -0800
+++ b/include/linux/rcupdate.h	2008-02-12 14:56:17.000000000 -0800
@@ -178,7 +178,7 @@ struct rcu_head {
 
 #define rcu_assign_pointer(p, v)			\
 	({						\
-		if (!(__builtin_constant_p(v) && v))	\
+		if (!__builtin_constant_p(v) || v)	\
 			smp_wmb();			\
 		(p) = (v);				\
 	})

-- 
Stephen Hemminger <shemminger@vyatta.com>

Re: [PATCH 1/4] rcu_assign_pointer: null check fix

[David Miller]

From: Stephen Hemminger <shemminger@vyatta.com>
Date: Tue, 12 Feb 2008 16:50:43 -0800

> Goofed on last change, should avoid barrier only on rcu_assign_pointer(p, NULL)
> 
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>

Like the original change this needs to be merged upstream outside of
the networking tree, sorry.

Re: [PATCH 1/4] rcu_assign_pointer: null check fix

[Jarek Poplawski]

On 13-02-2008 01:50, Stephen Hemminger wrote:
...
> --- a/include/linux/rcupdate.h	2008-02-12 14:46:49.000000000 -0800
> +++ b/include/linux/rcupdate.h	2008-02-12 14:56:17.000000000 -0800
> @@ -178,7 +178,7 @@ struct rcu_head {
>  
>  #define rcu_assign_pointer(p, v)			\
>  	({						\
> -		if (!(__builtin_constant_p(v) && v))	\
> +		if (!__builtin_constant_p(v) || v)	\

Isn't it a bit safer with this Paul's version yet?:

 +		if (!__builtin_constant_p(v) || (v))	\

Jarek P.

[PATCH 2/4] fib_trie: improve output format for /proc/net/fib_trie

[Stephen Hemminger]

[-- Attachment #1: fib-trie-format.patch --]
[-- Type: text/plain, Size: 5136 bytes --]

Make output format prettier (more tree like).

   <local>:
   --- 0.0.0.0/0
     |--- 10.111.111.0/24
     |  +-- 10.111.111.0/32 link broadcast
     |  |--- 10.111.111.254/31
     |  |  +-- 10.111.111.254/32 host local
     |  |  +-- 10.111.111.255/32 link broadcast
     |--- 127.0.0.0/8
     |  |--- 127.0.0.0/31
     |  |  +-- 127.0.0.0/32 link broadcast
     |  |  +-- 127.0.0.0/8 host local
     |  |  +-- 127.0.0.1/32 host local
     |  +-- 127.255.255.255/32 link broadcast
     |--- 192.168.1.0/24
     |  |--- 192.168.1.0/28
     |  |  +-- 192.168.1.0/32 link broadcast
     |  |  +-- 192.168.1.9/32 host local
     |  +-- 192.168.1.255/32 link broadcast
   <main>:
   --- 0.0.0.0/0
     |--- 0.0.0.0/4
     |  +-- 0.0.0.0/0 universe unicast
     |  +-- 10.111.111.0/24 link unicast
     +-- 169.254.0.0/16 link unicast
     +-- 192.168.1.0/24 link unicast
   
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
---
 net/ipv4/fib_trie.c |  106 ++++++++++++++++++++++++++------------------------
 1 files changed, 55 insertions(+), 51 deletions(-)

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 1ff446d..72338cd 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -2340,46 +2340,57 @@ static void fib_trie_seq_stop(struct seq_file *seq, void *v)
 	rcu_read_unlock();
 }
 
+/* print left side of tree */
 static void seq_indent(struct seq_file *seq, int n)
 {
-	while (n-- > 0) seq_puts(seq, "   ");
-}
-
-static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
-{
-	switch (s) {
-	case RT_SCOPE_UNIVERSE: return "universe";
-	case RT_SCOPE_SITE:	return "site";
-	case RT_SCOPE_LINK:	return "link";
-	case RT_SCOPE_HOST:	return "host";
-	case RT_SCOPE_NOWHERE:	return "nowhere";
-	default:
-		snprintf(buf, len, "scope=%d", s);
-		return buf;
-	}
+	while (n-- > 0)
+		seq_puts(seq, "  |");
 }
 
 static const char *rtn_type_names[__RTN_MAX] = {
-	[RTN_UNSPEC] = "UNSPEC",
-	[RTN_UNICAST] = "UNICAST",
-	[RTN_LOCAL] = "LOCAL",
-	[RTN_BROADCAST] = "BROADCAST",
-	[RTN_ANYCAST] = "ANYCAST",
-	[RTN_MULTICAST] = "MULTICAST",
-	[RTN_BLACKHOLE] = "BLACKHOLE",
-	[RTN_UNREACHABLE] = "UNREACHABLE",
-	[RTN_PROHIBIT] = "PROHIBIT",
-	[RTN_THROW] = "THROW",
-	[RTN_NAT] = "NAT",
-	[RTN_XRESOLVE] = "XRESOLVE",
+	[RTN_UNSPEC]	= "unspec",
+	[RTN_UNICAST]	= "unicast",
+	[RTN_LOCAL]	= "local",
+	[RTN_BROADCAST] = "broadcast",
+	[RTN_ANYCAST]	= "anycast",
+	[RTN_MULTICAST] = "multicast",
+	[RTN_BLACKHOLE] = "blackhole",
+	[RTN_UNREACHABLE] = "unreachable",
+	[RTN_PROHIBIT] 	= "prohibit",
+	[RTN_THROW]	= "throw",
+	[RTN_NAT]	= "nat",
+	[RTN_XRESOLVE]	= "xresolve",
 };
 
-static inline const char *rtn_type(char *buf, size_t len, unsigned t)
-{
-	if (t < __RTN_MAX && rtn_type_names[t])
-		return rtn_type_names[t];
-	snprintf(buf, len, "type %u", t);
-	return buf;
+static void fib_trie_show_alias(struct seq_file *seq, const struct fib_alias *fa)
+{
+	switch (fa->fa_scope) {
+	case RT_SCOPE_UNIVERSE:
+		seq_puts(seq, "universe");
+		break;
+	case RT_SCOPE_SITE:
+		seq_puts(seq,  "site");
+		break;
+	case RT_SCOPE_LINK:
+		seq_puts(seq,  "link");
+		break;
+	case RT_SCOPE_HOST:
+		seq_puts(seq,  "host");
+		break;
+	case RT_SCOPE_NOWHERE:
+		seq_puts(seq,  "nowhere");
+		break;
+	default:
+		seq_printf(seq, "scope:%d", fa->fa_scope);
+	}
+
+	if (fa->fa_type < __RTN_MAX && rtn_type_names[fa->fa_type])
+		seq_printf(seq, " %s", rtn_type_names[fa->fa_type]);
+	else
+		seq_printf(seq, " type:%u", fa->fa_type);
+	
+	if (fa->fa_tos)
+		seq_printf(seq, " tos:%#x", fa->fa_tos);
 }
 
 /* Pretty print the trie */
@@ -2402,10 +2413,8 @@ static int fib_trie_seq_show(struct seq_file *seq, void *v)
 		struct tnode *tn = (struct tnode *) n;
 		__be32 prf = htonl(mask_pfx(tn->key, tn->pos));
 
-		seq_indent(seq, iter->depth-1);
-		seq_printf(seq, "  +-- %d.%d.%d.%d/%d %d %d %d\n",
-			   NIPQUAD(prf), tn->pos, tn->bits, tn->full_children,
-			   tn->empty_children);
+		seq_indent(seq, iter->depth - 1);
+		seq_printf(seq, "--- %d.%d.%d.%d/%d\n", NIPQUAD(prf), tn->pos);
 
 	} else {
 		struct leaf *l = (struct leaf *) n;
@@ -2413,24 +2422,19 @@ static int fib_trie_seq_show(struct seq_file *seq, void *v)
 		struct hlist_node *node;
 		__be32 val = htonl(l->key);
 
-		seq_indent(seq, iter->depth);
-		seq_printf(seq, "  |-- %d.%d.%d.%d\n", NIPQUAD(val));
-
 		hlist_for_each_entry_rcu(li, node, &l->list, hlist) {
 			struct fib_alias *fa;
+			
+			seq_indent(seq, iter->depth - 1);	
+			seq_printf(seq, "  +-- %d.%d.%d.%d/%d ",
+				   NIPQUAD(val), li->plen);
 
 			list_for_each_entry_rcu(fa, &li->falh, fa_list) {
-				char buf1[32], buf2[32];
-
-				seq_indent(seq, iter->depth+1);
-				seq_printf(seq, "  /%d %s %s", li->plen,
-					   rtn_scope(buf1, sizeof(buf1),
-						     fa->fa_scope),
-					   rtn_type(buf2, sizeof(buf2),
-						    fa->fa_type));
-				if (fa->fa_tos)
-					seq_printf(seq, " tos=%d", fa->fa_tos);
-				seq_putc(seq, '\n');
+				fib_trie_show_alias(seq, fa);
+				if (list_is_last(&fa->fa_list, &li->falh))
+					seq_putc(seq, '\n');
+				else
+					seq_puts(seq, ", ");
 			}
 		}
 	}
-- 
1.5.3.8

-- 
Stephen Hemminger <shemminger@vyatta.com>

Re: [PATCH 2/4] fib_trie: improve output format for /proc/net/fib_trie

[Andrew Morton]

On Tue, 12 Feb 2008 16:50:44 -0800 Stephen Hemminger <shemminger@vyatta.com> wrote:

> Make output format prettier (more tree like).
> 
>    <local>:
>    --- 0.0.0.0/0
>      |--- 10.111.111.0/24
>      |  +-- 10.111.111.0/32 link broadcast
>      |  |--- 10.111.111.254/31
>      |  |  +-- 10.111.111.254/32 host local
>      |  |  +-- 10.111.111.255/32 link broadcast
>      |--- 127.0.0.0/8
>      |  |--- 127.0.0.0/31
>      |  |  +-- 127.0.0.0/32 link broadcast
>      |  |  +-- 127.0.0.0/8 host local
>      |  |  +-- 127.0.0.1/32 host local
>      |  +-- 127.255.255.255/32 link broadcast
>      |--- 192.168.1.0/24
>      |  |--- 192.168.1.0/28
>      |  |  +-- 192.168.1.0/32 link broadcast
>      |  |  +-- 192.168.1.9/32 host local
>      |  +-- 192.168.1.255/32 link broadcast
>    <main>:
>    --- 0.0.0.0/0
>      |--- 0.0.0.0/4
>      |  +-- 0.0.0.0/0 universe unicast
>      |  +-- 10.111.111.0/24 link unicast
>      +-- 169.254.0.0/16 link unicast
>      +-- 192.168.1.0/24 link unicast

isn't that a non-back-compatible kernel ABI change?  It might
break pre-existing parsers?

aside: how lame are we to put pretty-printers in the kernel?
English-only ones, at that?  Root cause: kernel developers still
don't have a sufficiently easy way of shipping userspace tools.

Re: [PATCH 2/4] fib_trie: improve output format for /proc/net/fib_trie

[Stephen Hemminger]

Andrew Morton wrote:
> On Tue, 12 Feb 2008 16:50:44 -0800 Stephen Hemminger <shemminger@vyatta.com> wrote:
>
>   
>> Make output format prettier (more tree like).
>>
>>    <local>:
>>    --- 0.0.0.0/0
>>      |--- 10.111.111.0/24
>>      |  +-- 10.111.111.0/32 link broadcast
>>      |  |--- 10.111.111.254/31
>>      |  |  +-- 10.111.111.254/32 host local
>>      |  |  +-- 10.111.111.255/32 link broadcast
>>      |--- 127.0.0.0/8
>>      |  |--- 127.0.0.0/31
>>      |  |  +-- 127.0.0.0/32 link broadcast
>>      |  |  +-- 127.0.0.0/8 host local
>>      |  |  +-- 127.0.0.1/32 host local
>>      |  +-- 127.255.255.255/32 link broadcast
>>      |--- 192.168.1.0/24
>>      |  |--- 192.168.1.0/28
>>      |  |  +-- 192.168.1.0/32 link broadcast
>>      |  |  +-- 192.168.1.9/32 host local
>>      |  +-- 192.168.1.255/32 link broadcast
>>    <main>:
>>    --- 0.0.0.0/0
>>      |--- 0.0.0.0/4
>>      |  +-- 0.0.0.0/0 universe unicast
>>      |  +-- 10.111.111.0/24 link unicast
>>      +-- 169.254.0.0/16 link unicast
>>      +-- 192.168.1.0/24 link unicast
>>     
>
> isn't that a non-back-compatible kernel ABI change?  It might
> break pre-existing parsers?
>
>   
Fib trie was always experimental and the output format was intended to 
be tree like
but was broken. There are no known parsers of fib trie, and I think 
Vyatta will probably
be the first distro to ship with it enabled.
> aside: how lame are we to put pretty-printers in the kernel?
> English-only ones, at that?  Root cause: kernel developers still
> don't have a sufficiently easy way of shipping userspace tools.
Agreed, the structure of the trie doesn't come out via netlink (only the 
addresses).

Re: [PATCH 4/4] hlist_for_each_entry_continue simplification

[David Miller]

From: Stephen Hemminger <shemminger@vyatta.com>
Date: Tue, 12 Feb 2008 16:50:46 -0800

> All the users of hlist_for_each_entry_continue had to intialize pos
> before use; change API so pos is a pure temporary variable which matches
> the usage of other xxxx_for_each_entry routines.
> 
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>

linux/list.h changes need to be reviewed on linux-kernel and
merged into Linus's tree via some means other than the
networking tree.

I just got chewed out for a similar issue wrt. the rcupdate.h
changes of yesterday and thus have to remove them from my
tree.