NFSv4.1: Don't loop forever in nfs4_proc_create_session

If a server for some reason keeps sending NFS4ERR_DELAY errors, we can end
up looping forever inside nfs4_proc_create_session, and so the usual
mechanisms for detecting if the nfs_client is dead don't work.

Fix this by ensuring that we loop inside the nfs4_state_manager thread
instead.

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

3 files changed, 39 insertions, 53 deletions

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index e1c261ddd65d..c4a69833dd0d 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -47,6 +47,7 @@ enum nfs4_client_state {
         NFS4CLNT_LAYOUTRECALL,
         NFS4CLNT_SESSION_RESET,
         NFS4CLNT_RECALL_SLOT,
+        NFS4CLNT_LEASE_CONFIRM,
 };
 
 enum nfs4_session_state {
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 628e35f75307..50c814828fcb 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3754,18 +3754,17 @@ int nfs4_proc_setclientid(struct nfs_client *clp, u32 program,
                 status = rpc_call_sync(clp->cl_rpcclient, &msg, 0);
                 if (status != -NFS4ERR_CLID_INUSE)
                         break;
-                if (signalled())
+                if (loop != 0) {
+                        ++clp->cl_id_uniquifier;
                         break;
-                if (loop++ & 1)
-                        ssleep(clp->cl_lease_time / HZ + 1);
-                else
-                        if (++clp->cl_id_uniquifier == 0)
-                                break;
+                }
+                ++loop;
+                ssleep(clp->cl_lease_time / HZ + 1);
         }
         return status;
 }
 
-static int _nfs4_proc_setclientid_confirm(struct nfs_client *clp,
+int nfs4_proc_setclientid_confirm(struct nfs_client *clp,
                 struct nfs4_setclientid_res *arg,
                 struct rpc_cred *cred)
 {
@@ -3790,26 +3789,6 @@ static int _nfs4_proc_setclientid_confirm(struct nfs_client *clp,
         return status;
 }
 
-int nfs4_proc_setclientid_confirm(struct nfs_client *clp,
-                struct nfs4_setclientid_res *arg,
-                struct rpc_cred *cred)
-{
-        long timeout = 0;
-        int err;
-        do {
-                err = _nfs4_proc_setclientid_confirm(clp, arg, cred);
-                switch (err) {
-                        case 0:
-                                return err;
-                        case -NFS4ERR_RESOURCE:
-                                /* The IBM lawyers misread another document! */
-                        case -NFS4ERR_DELAY:
-                                err = nfs4_delay(clp->cl_rpcclient, &timeout);
-                }
-        } while (err == 0);
-        return err;
-}
-
 struct nfs4_delegreturndata {
         struct nfs4_delegreturnargs args;
         struct nfs4_delegreturnres res;
@@ -5222,20 +5201,10 @@ int nfs4_proc_create_session(struct nfs_client *clp)
         int status;
         unsigned *ptr;
         struct nfs4_session *session = clp->cl_session;
-        long timeout = 0;
-        int err;
 
         dprintk("--> %s clp=%p session=%p\n", __func__, clp, session);
 
-        do {
-                status = _nfs4_proc_create_session(clp);
-                if (status == -NFS4ERR_DELAY) {
-                        err = nfs4_delay(clp->cl_rpcclient, &timeout);
-                        if (err)
-                                status = err;
-                }
-        } while (status == -NFS4ERR_DELAY);
-
+        status = _nfs4_proc_create_session(clp);
         if (status)
                 goto out;
 
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 4dfb34b43ffb..4a810c8b0753 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -64,10 +64,15 @@ static LIST_HEAD(nfs4_clientid_list);
 
 int nfs4_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
 {
-        struct nfs4_setclientid_res clid;
+        struct nfs4_setclientid_res clid = {
+                .clientid = clp->cl_clientid,
+                .confirm = clp->cl_confirm,
+        };
         unsigned short port;
         int status;
 
+        if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
+                goto do_confirm;
         port = nfs_callback_tcpport;
         if (clp->cl_addr.ss_family == AF_INET6)
                 port = nfs_callback_tcpport6;
@@ -75,10 +80,14 @@ int nfs4_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
         if (status != 0)
                 goto out;
+        clp->cl_clientid = clid.clientid;
+        clp->cl_confirm = clid.confirm;
+        set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
+do_confirm:
         status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
         if (status != 0)
                 goto out;
-        clp->cl_clientid = clid.clientid;
+        clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
         nfs4_schedule_state_renewal(clp);
 out:
         return status;
@@ -230,13 +239,18 @@ int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
 {
         int status;
 
+        if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
+                goto do_confirm;
         nfs4_begin_drain_session(clp);
         status = nfs4_proc_exchange_id(clp, cred);
         if (status != 0)
                 goto out;
+        set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
+do_confirm:
         status = nfs4_proc_create_session(clp);
         if (status != 0)
                 goto out;
+        clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
         nfs41_setup_state_renewal(clp);
         nfs_mark_client_ready(clp, NFS_CS_READY);
 out:
@@ -1584,20 +1598,22 @@ static int nfs4_recall_slot(struct nfs_client *clp) { return 0; }
  */
 static void nfs4_set_lease_expired(struct nfs_client *clp, int status)
 {
-        if (nfs4_has_session(clp)) {
-                switch (status) {
-                case -NFS4ERR_DELAY:
-                case -NFS4ERR_CLID_INUSE:
-                case -EAGAIN:
-                        break;
+        switch (status) {
+        case -NFS4ERR_CLID_INUSE:
+        case -NFS4ERR_STALE_CLIENTID:
+                clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
+                break;
+        case -NFS4ERR_DELAY:
+        case -EAGAIN:
+                ssleep(1);
+                break;
 
-                case -EKEYEXPIRED:
-                        nfs4_warn_keyexpired(clp->cl_hostname);
-                case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
-                                         * in nfs4_exchange_id */
-                default:
-                        return;
-                }
+        case -EKEYEXPIRED:
+                nfs4_warn_keyexpired(clp->cl_hostname);
+        case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
+                                 * in nfs4_exchange_id */
+        default:
+                return;
         }
         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
 }