From: Peter Staubach <staubach@redhat.com>
Date: Thu, 2 Apr 2009 15:54:09 -0400
Subject: [nfs] memory leak when reading files wth option 'noac'
Message-id: 49D517E1.6030209@redhat.com
O-Subject: [RHEL-5.5 PATCH] bz493045 memory leak when reading from files mounted with nfs mount option 'noac'
Bugzilla: 493045
RH-Acked-by: Jeff Layton <jlayton@redhat.com>

Hi.

Attached is a patch to address bz493045, "memory leak when
reading from files mounted with nfs mount option 'noac'".
This bugzilla describes a problem where the system leaks
memory when reading from files located on NFS mounted file
systems mounted with the mount option, "noac".

The use of the mount option, "noac", causes the NFS client
to follow a synchronous path when reading pages.  This path
is not followed except in this case.

This path allocates some memory, performs the over the wire
READ operation, but then fails to free the memory which was
allocated.  Interestingly, if the over the wire READ
operation fails, then the memory is correctly freed.

The solution is to simply add the call to free the allocated
memory.

    Thanx...

       ps

diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 4dde1a0..8b14dfb 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -217,6 +217,7 @@ static int nfs_readpage_sync(struct nfs_open_context *ctx, struct inode *inode,
 	result = 0;
 
 	nfs_readpage_to_fscache(inode, page, 1);
+	nfs_readdata_free(rdata);
 	unlock_page(page);
 
 	return result;