[PATCH] NFS: Fix NFSv4 callback regression

The change in semantics for nfs_find_client() introduced by David breaks the
NFSv4 callback channel.

Also, replace another completely broken BUG_ON() in nfs_find_client().  In
initialised clients, clp->cl_cons_state == 0, and callers of that function
should in any case never want to see clients that are uninitialised.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 12 insertions, 7 deletions

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 8b123f6a7d02..5fea638743e4 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -232,11 +232,15 @@ void nfs_put_client(struct nfs_client *clp)
  * Find a client by address
  * - caller must hold nfs_client_lock
  */
-static struct nfs_client *__nfs_find_client(const struct sockaddr_in *addr, int nfsversion)
+static struct nfs_client *__nfs_find_client(const struct sockaddr_in *addr, int nfsversion, int match_port)
 {
         struct nfs_client *clp;
 
         list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
+                /* Don't match clients that failed to initialise properly */
+                if (clp->cl_cons_state < 0)
+                        continue;
+
                 /* Different NFS versions cannot share the same nfs_client */
                 if (clp->cl_nfsversion != nfsversion)
                         continue;
@@ -245,7 +249,7 @@ static struct nfs_client *__nfs_find_client(const struct sockaddr_in *addr, int
                            sizeof(clp->cl_addr.sin_addr)) != 0)
                         continue;
 
-                if (clp->cl_addr.sin_port == addr->sin_port)
+                if (!match_port || clp->cl_addr.sin_port == addr->sin_port)
                         goto found;
         }
 
@@ -265,11 +269,12 @@ struct nfs_client *nfs_find_client(const struct sockaddr_in *addr, int nfsversio
         struct nfs_client *clp;
 
         spin_lock(&nfs_client_lock);
-        clp = __nfs_find_client(addr, nfsversion);
+        clp = __nfs_find_client(addr, nfsversion, 0);
         spin_unlock(&nfs_client_lock);
-
-        BUG_ON(clp && clp->cl_cons_state == 0);
-
+        if (clp != NULL && clp->cl_cons_state != NFS_CS_READY) {
+                nfs_put_client(clp);
+                clp = NULL;
+        }
         return clp;
 }
 
@@ -292,7 +297,7 @@ static struct nfs_client *nfs_get_client(const char *hostname,
         do {
                 spin_lock(&nfs_client_lock);
 
-                clp = __nfs_find_client(addr, nfsversion);
+                clp = __nfs_find_client(addr, nfsversion, 1);
                 if (clp)
                         goto found_client;
                 if (new)