From: Wendy Cheng <wcheng@redhat.com>
Subject: [PATCH] Fix lockd oops caused by f_count
Date: Wed, 18 Apr 2007 11:09:53 -0400
Message-ID: <1176908994.8837.11.camel@wendyc-t.rdu.redhat.com>
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Code segment breaks out of the original NLM failover patch set since it
is a bug fix for current lockd (server) code. 

When posix locks are still held by NLM clients, lockd server side could
oops if nlm_traverse_files() is invoked. The code falsely relies on
f_count to identify whether the file lock is in-use. The f_count can be
zero as soon as NLM server RPC call is returned while client is having
the lock.

Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>

 svcsubs.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- gfs2-nmw/fs/lockd/svcsubs.c	2007-04-10 11:59:09.000000000 -0400
+++ linux/fs/lockd/svcsubs.c	2007-04-18 10:01:23.000000000 -0400
@@ -250,8 +250,7 @@ nlm_traverse_files(struct nlm_host *host
 			mutex_lock(&nlm_file_mutex);
 			file->f_count--;
 			/* No more references to this file. Let go of it. */
-			if (list_empty(&file->f_blocks) && !file->f_locks
-			 && !file->f_shares && !file->f_count) {
+			if (!nlm_file_inuse(file)) {
 				hlist_del(&file->f_list);
 				nlmsvc_ops->fclose(file->f_file);
 				kfree(file);


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