diff options
| author | NeilBrown <neilb@suse.de> | 2012-10-31 12:16:01 +1100 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-10-31 16:25:59 -0400 |
| commit | 8d96b10639fb402357b75b055b1e82a65ff95050 (patch) | |
| tree | 13e1e4d63538e1f0177b64fee0b8ab7e96786089 /fs | |
| parent | 2b1bc308f492589f7d49012ed24561534ea2be8c (diff) | |
| download | lwn-8d96b10639fb402357b75b055b1e82a65ff95050.tar.gz lwn-8d96b10639fb402357b75b055b1e82a65ff95050.zip | |
NFS: fix bug in legacy DNS resolver.
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>
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfs/dns_resolve.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/nfs/dns_resolve.c b/fs/nfs/dns_resolve.c index 31c26c4dcc23..ca4b11ec87a2 100644 --- a/fs/nfs/dns_resolve.c +++ b/fs/nfs/dns_resolve.c @@ -217,7 +217,7 @@ static int nfs_dns_parse(struct cache_detail *cd, char *buf, int buflen) { char buf1[NFS_DNS_HOSTNAME_MAXLEN+1]; struct nfs_dns_ent key, *item; - unsigned long ttl; + unsigned int ttl; ssize_t len; int ret = -EINVAL; @@ -240,7 +240,8 @@ static int nfs_dns_parse(struct cache_detail *cd, char *buf, int buflen) key.namelen = len; memset(&key.h, 0, sizeof(key.h)); - ttl = get_expiry(&buf); + if (get_uint(&buf, &ttl) < 0) + goto out; if (ttl == 0) goto out; key.h.expiry_time = ttl + seconds_since_boot(); |