Patch "ipv4: Restore fib_trie_flush_external function and fix call ordering" has been added to the 4.8-stable tree

Patch "ipv4: Restore fib_trie_flush_external function and fix call ordering" has been added to the 4.8-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    ipv4: Restore fib_trie_flush_external function and fix call ordering

to the 4.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ipv4-restore-fib_trie_flush_external-function-and-fix-call-ordering.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Thu Dec  8 07:19:12 CET 2016
From: Alexander Duyck <alexander.h.duyck@intel.com>
Date: Tue, 15 Nov 2016 05:46:06 -0500
Subject: ipv4: Restore fib_trie_flush_external function and fix call ordering

From: Alexander Duyck <alexander.h.duyck@intel.com>


[ Upstream commit 3b7093346b326e5d3590c7d49f6aefe6fa5b2c9a, the FIB offload
  removal didn't occur in 4.8 so that part of this patch isn't here.  However
  we still need to fib_unmerge() bits. ]

The patch that removed the FIB offload infrastructure was a bit too
aggressive and also removed code needed to clean up us splitting the table
if additional rules were added.  Specifically the function
fib_trie_flush_external was called at the end of a new rule being added to
flush the foreign trie entries from the main trie.

I updated the code so that we only call fib_trie_flush_external on the main
table so that we flush the entries for local from main.  This way we don't
call it for every rule change which is what was happening previously.

Fixes: 347e3b28c1ba2 ("switchdev: remove FIB offload infrastructure")
Reported-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv4/fib_frontend.c |   20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -157,7 +157,7 @@ static void fib_replace_table(struct net
 
 int fib_unmerge(struct net *net)
 {
-	struct fib_table *old, *new;
+	struct fib_table *old, *new, *main_table;
 
 	/* attempt to fetch local table if it has been allocated */
 	old = fib_get_table(net, RT_TABLE_LOCAL);
@@ -168,11 +168,21 @@ int fib_unmerge(struct net *net)
 	if (!new)
 		return -ENOMEM;
 
+	/* table is already unmerged */
+	if (new == old)
+		return 0;
+
 	/* replace merged table with clean table */
-	if (new != old) {
-		fib_replace_table(net, old, new);
-		fib_free_table(old);
-	}
+	fib_replace_table(net, old, new);
+	fib_free_table(old);
+
+	/* attempt to fetch main table if it has been allocated */
+	main_table = fib_get_table(net, RT_TABLE_MAIN);
+	if (!main_table)
+		return 0;
+
+	/* flush local entries from main table */
+	fib_table_flush_external(main_table);
 
 	return 0;
 }


Patches currently in stable-queue which might be from alexander.h.duyck@intel.com are

queue-4.8/ipv4-fix-memory-leak-in-exception-case-for-splitting-tries.patch
queue-4.8/ipv4-restore-fib_trie_flush_external-function-and-fix-call-ordering.patch
queue-4.8/gso-reload-iph-after-pskb_may_pull.patch
queue-4.8/ipv4-drop-suffix-update-from-resize-code.patch
queue-4.8/ipv4-drop-leaf-from-suffix-pull-push-functions.patch