NFSv4: Iterate through all nfs_clients when the server recalls a delegation

The same delegation may have been handed out to more than one nfs_client.
Ensure that if a recall occurs, we return all instances.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

3 files changed, 58 insertions, 17 deletions

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index e89a9007c91c..15f7785048d3 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -75,23 +75,28 @@ __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy)
         dprintk("NFS: RECALL callback request from %s\n",
                 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
 
-        inode = nfs_delegation_find_inode(clp, &args->fh);
-        if (inode == NULL)
-                goto out_putclient;
-        /* Set up a helper thread to actually return the delegation */
-        switch(nfs_async_inode_return_delegation(inode, &args->stateid)) {
-                case 0:
-                        res = 0;
-                        break;
-                case -ENOENT:
-                        res = htonl(NFS4ERR_BAD_STATEID);
-                        break;
-                default:
-                        res = htonl(NFS4ERR_RESOURCE);
-        }
-        iput(inode);
-out_putclient:
-        nfs_put_client(clp);
+        do {
+                struct nfs_client *prev = clp;
+
+                inode = nfs_delegation_find_inode(clp, &args->fh);
+                if (inode != NULL) {
+                        /* Set up a helper thread to actually return the delegation */
+                        switch(nfs_async_inode_return_delegation(inode, &args->stateid)) {
+                                case 0:
+                                        res = 0;
+                                        break;
+                                case -ENOENT:
+                                        if (res != 0)
+                                                res = htonl(NFS4ERR_BAD_STATEID);
+                                        break;
+                                default:
+                                        res = htonl(NFS4ERR_RESOURCE);
+                        }
+                        iput(inode);
+                }
+                clp = nfs_find_client_next(prev);
+                nfs_put_client(prev);
+        } while (clp != NULL);
 out:
         dprintk("%s: exit with status = %d\n", __FUNCTION__, ntohl(res));
         return res;
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 7a15832369e9..685c43f810c1 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -276,6 +276,41 @@ struct nfs_client *nfs_find_client(const struct sockaddr *addr, u32 nfsversion)
 }
 
 /*
+ * Find a client by IP address and protocol version
+ * - returns NULL if no such client
+ */
+struct nfs_client *nfs_find_client_next(struct nfs_client *clp)
+{
+        struct sockaddr *sap = (struct sockaddr *)&clp->cl_addr;
+        u32 nfsvers = clp->rpc_ops->version;
+
+        spin_lock(&nfs_client_lock);
+        list_for_each_entry_continue(clp, &nfs_client_list, cl_share_link) {
+                struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
+
+                /* Don't match clients that failed to initialise properly */
+                if (clp->cl_cons_state != NFS_CS_READY)
+                        continue;
+
+                /* Different NFS versions cannot share the same nfs_client */
+                if (clp->rpc_ops->version != nfsvers)
+                        continue;
+
+                if (sap->sa_family != clap->sa_family)
+                        continue;
+                /* Match only the IP address, not the port number */
+                if (!nfs_sockaddr_match_ipaddr(sap, clap))
+                        continue;
+
+                atomic_inc(&clp->cl_count);
+                spin_unlock(&nfs_client_lock);
+                return clp;
+        }
+        spin_unlock(&nfs_client_lock);
+        return NULL;
+}
+
+/*
  * Find an nfs_client on the list that matches the initialisation data
  * that is supplied.
  */
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index a80621199086..0f5619611b8d 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -64,6 +64,7 @@ extern struct rpc_program nfs_program;
 
 extern void nfs_put_client(struct nfs_client *);
 extern struct nfs_client *nfs_find_client(const struct sockaddr *, u32);
+extern struct nfs_client *nfs_find_client_next(struct nfs_client *);
 extern struct nfs_server *nfs_create_server(
                                         const struct nfs_parsed_mount_data *,
                                         struct nfs_fh *);