NFS: fix bug in legacy DNS resolver.
authorNeilBrown <neilb@suse.de>
Wed, 31 Oct 2012 01:16:01 +0000 (12:16 +1100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 17 Nov 2012 21:16:12 +0000 (13:16 -0800)
commit088eb1bed178645788538611ac31ba9991cd88c4
treeee637ef3a4b53b4c4f25605865ed6a252de15105
parent588c72e88125b1abe50efb3f1b6b768b98302e2c
NFS: fix bug in legacy DNS resolver.

commit 8d96b10639fb402357b75b055b1e82a65ff95050 upstream.

The DNS resolver's use of the sunrpc cache involves a 'ttl' number
(relative) rather that a timeout (absolute).  This confused me when
I wrote
  commit c5b29f885afe890f953f7f23424045cdad31d3e4
     "sunrpc: use seconds since boot in expiry cache"

and I managed to break it.  The effect is that any TTL is interpreted
as 0, and nothing useful gets into the cache.

This patch removes the use of get_expiry() - which really expects an
expiry time - and uses get_uint() instead, treating the int correctly
as a ttl.

This fixes a regression that has been present since 2.6.37, causing
certain NFS accesses in certain environments to incorrectly fail.

Reported-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/nfs/dns_resolve.c