NFSv4: State recovery cleanup

 Use wait_on_bit() when waiting for state recovery to complete.

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

3 files changed, 28 insertions, 25 deletions

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 4ad5981f9375..1d4c5b339b4d 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -38,7 +38,7 @@ struct idmap;
  ((err) != NFSERR_NOFILEHANDLE))
 
 enum nfs4_client_state {
-        NFS4CLNT_OK  = 0,
+        NFS4CLNT_STATE_RECOVER  = 0,
 };
 
 /*
@@ -76,7 +76,6 @@ struct nfs4_client {
         struct work_struct      cl_renewd;
         struct work_struct      cl_recoverd;
 
-        wait_queue_head_t       cl_waitq;
         struct rpc_wait_queue   cl_rpcwaitq;
 
         /* used for the setclientid verifier */
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 76d7d0259b6c..46623ac3ce86 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2736,7 +2736,7 @@ nfs4_async_handle_error(struct rpc_task *task, const struct nfs_server *server)
                 case -NFS4ERR_EXPIRED:
                         rpc_sleep_on(&clp->cl_rpcwaitq, task, NULL, NULL);
                         nfs4_schedule_state_recovery(clp);
-                        if (test_bit(NFS4CLNT_OK, &clp->cl_state))
+                        if (test_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) == 0)
                                 rpc_wake_up_task(task);
                         task->tk_status = 0;
                         return -EAGAIN;
@@ -2753,25 +2753,25 @@ nfs4_async_handle_error(struct rpc_task *task, const struct nfs_server *server)
         return 0;
 }
 
+static int nfs4_wait_bit_interruptible(void *word)
+{
+        if (signal_pending(current))
+                return -ERESTARTSYS;
+        schedule();
+        return 0;
+}
+
 static int nfs4_wait_clnt_recover(struct rpc_clnt *clnt, struct nfs4_client *clp)
 {
-        DEFINE_WAIT(wait);
         sigset_t oldset;
-        int interruptible, res = 0;
+        int res;
 
         might_sleep();
 
         rpc_clnt_sigmask(clnt, &oldset);
-        interruptible = TASK_UNINTERRUPTIBLE;
-        if (clnt->cl_intr)
-                interruptible = TASK_INTERRUPTIBLE;
-        prepare_to_wait(&clp->cl_waitq, &wait, interruptible);
-        nfs4_schedule_state_recovery(clp);
-        if (clnt->cl_intr && signalled())
-                res = -ERESTARTSYS;
-        else if (!test_bit(NFS4CLNT_OK, &clp->cl_state))
-                schedule();
-        finish_wait(&clp->cl_waitq, &wait);
+        res = wait_on_bit(&clp->cl_state, NFS4CLNT_STATE_RECOVER,
+                        nfs4_wait_bit_interruptible,
+                        TASK_INTERRUPTIBLE);
         rpc_clnt_sigunmask(clnt, &oldset);
         return res;
 }
@@ -2814,6 +2814,7 @@ int nfs4_handle_exception(const struct nfs_server *server, int errorcode, struct
                 case -NFS4ERR_STALE_CLIENTID:
                 case -NFS4ERR_STALE_STATEID:
                 case -NFS4ERR_EXPIRED:
+                        nfs4_schedule_state_recovery(clp);
                         ret = nfs4_wait_clnt_recover(server->client, clp);
                         if (ret == 0)
                                 exception->retry = 1;
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 41a5f1a8a984..4ebf4df7f191 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -106,11 +106,10 @@ nfs4_alloc_client(struct in_addr *addr)
         INIT_WORK(&clp->cl_recoverd, nfs4_recover_state, clp);
         INIT_WORK(&clp->cl_renewd, nfs4_renew_state, clp);
         INIT_LIST_HEAD(&clp->cl_superblocks);
-        init_waitqueue_head(&clp->cl_waitq);
         rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS4 client");
         clp->cl_rpcclient = ERR_PTR(-EINVAL);
         clp->cl_boot_time = CURRENT_TIME;
-        clp->cl_state = 1 << NFS4CLNT_OK;
+        clp->cl_state = 0;
         return clp;
 }
 
@@ -193,7 +192,6 @@ nfs4_put_client(struct nfs4_client *clp)
         list_del(&clp->cl_servers);
         spin_unlock(&state_spinlock);
         BUG_ON(!list_empty(&clp->cl_superblocks));
-        wake_up_all(&clp->cl_waitq);
         rpc_wake_up(&clp->cl_rpcwaitq);
         nfs4_kill_renewd(clp);
         nfs4_free_client(clp);
@@ -741,6 +739,15 @@ struct reclaimer_args {
         struct completion complete;
 };
 
+static inline void nfs4_clear_recover_bit(struct nfs4_client *clp)
+{
+        smp_mb__before_clear_bit();
+        clear_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state);
+        smp_mb__after_clear_bit();
+        wake_up_bit(&clp->cl_state, NFS4CLNT_STATE_RECOVER);
+        rpc_wake_up(&clp->cl_rpcwaitq);
+}
+
 /*
  * State recovery routine
  */
@@ -760,9 +767,7 @@ nfs4_recover_state(void *data)
         wait_for_completion(&args.complete);
         return;
 out_failed_clear:
-        set_bit(NFS4CLNT_OK, &clp->cl_state);
-        wake_up_all(&clp->cl_waitq);
-        rpc_wake_up(&clp->cl_rpcwaitq);
+        nfs4_clear_recover_bit(clp);
 }
 
 /*
@@ -773,7 +778,7 @@ nfs4_schedule_state_recovery(struct nfs4_client *clp)
 {
         if (!clp)
                 return;
-        if (test_and_clear_bit(NFS4CLNT_OK, &clp->cl_state))
+        if (test_and_set_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) == 0)
                 schedule_work(&clp->cl_recoverd);
 }
 
@@ -943,13 +948,11 @@ restart_loop:
         }
         nfs_delegation_reap_unclaimed(clp);
 out:
-        set_bit(NFS4CLNT_OK, &clp->cl_state);
         up_write(&clp->cl_sem);
         unlock_kernel();
-        wake_up_all(&clp->cl_waitq);
-        rpc_wake_up(&clp->cl_rpcwaitq);
         if (status == -NFS4ERR_CB_PATH_DOWN)
                 nfs_handle_cb_pathdown(clp);
+        nfs4_clear_recover_bit(clp);
         nfs4_put_client(clp);
         return 0;
 out_error: