NFS: DNS resolver cache per network namespace context introduced

This patch implements DNS resolver cache creation and registration for each
alive network namespace context.
This was done by registering NFS per-net operations, responsible for DNS cache
allocation/register and unregister/destructioning instead of initialization and
destruction of static "nfs_dns_resolve" cache detail (this one was removed).
Pointer to network dns resolver cache is stored in new per-net "nfs_net"
structure.
This patch also changes nfs_dns_resolve_name() function prototype (and it's
calls) by adding network pointer parameter, which is used to get proper DNS
resolver cache pointer for do_cache_lookup_wait() call.

Note: empty nfs_dns_resolver_init() and nfs_dns_resolver_destroy() functions
will be used in next patch in the series.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index bb80c49b6533..919a36935924 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -94,13 +94,14 @@ static int nfs4_validate_fspath(struct dentry *dentry,
 }
 
 static size_t nfs_parse_server_name(char *string, size_t len,
-		struct sockaddr *sa, size_t salen)
+		struct sockaddr *sa, size_t salen, struct nfs_server *server)
 {
 	ssize_t ret;
 
 	ret = rpc_pton(string, len, sa, salen);
 	if (ret == 0) {
-		ret = nfs_dns_resolve_name(string, len, sa, salen);
+		ret = nfs_dns_resolve_name(server->client->cl_xprt->xprt_net,
+					   string, len, sa, salen);
 		if (ret < 0)
 			ret = 0;
 	}
@@ -137,7 +138,8 @@ static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
 			continue;
 
 		mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
-				mountdata->addr, addr_bufsize);
+				mountdata->addr, addr_bufsize,
+				NFS_SB(mountdata->sb));
 		if (mountdata->addrlen == 0)
 			continue;