diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 1db588a3f08b28c93bb491d354662c346ccee3fc..90cb10d7b6936d1fc478f46572728e65e3874f29 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -826,9 +826,10 @@ static void nfs3_proc_read_setup(struct nfs_read_data *data, struct rpc_message
 	msg->rpc_proc = &nfs3_procedures[NFS3PROC_READ];
 }
 
-static void nfs3_proc_read_rpc_prepare(struct rpc_task *task, struct nfs_read_data *data)
+static int nfs3_proc_read_rpc_prepare(struct rpc_task *task, struct nfs_read_data *data)
 {
 	rpc_call_start(task);
+	return 0;
 }
 
 static int nfs3_write_done(struct rpc_task *task, struct nfs_write_data *data)
@@ -847,9 +848,10 @@ static void nfs3_proc_write_setup(struct nfs_write_data *data, struct rpc_messag
 	msg->rpc_proc = &nfs3_procedures[NFS3PROC_WRITE];
 }
 
-static void nfs3_proc_write_rpc_prepare(struct rpc_task *task, struct nfs_write_data *data)
+static int nfs3_proc_write_rpc_prepare(struct rpc_task *task, struct nfs_write_data *data)
 {
 	rpc_call_start(task);
+	return 0;
 }
 
 static void nfs3_proc_commit_rpc_prepare(struct rpc_task *task, struct nfs_commit_data *data)
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index af2d5bf043f0d75ca489cf85dc7a6c5261f8ed01..64118316a407f0d58f0c3cf0d1b69ab2b499455b 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -133,6 +133,7 @@ struct nfs4_lock_state {
 	struct list_head	ls_locks;	/* Other lock stateids */
 	struct nfs4_state *	ls_state;	/* Pointer to open state */
 #define NFS_LOCK_INITIALIZED 0
+#define NFS_LOCK_LOST        1
 	unsigned long		ls_flags;
 	struct nfs_seqid_counter	ls_seqid;
 	nfs4_stateid		ls_stateid;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 0122919a311aa8306324bda95290d2af0ffb9714..1eb694e0f305b98a0e612dbf21db9a1fff3f1295 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4028,15 +4028,19 @@ static void nfs4_proc_read_setup(struct nfs_read_data *data, struct rpc_message
 	nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 0);
 }
 
-static void nfs4_proc_read_rpc_prepare(struct rpc_task *task, struct nfs_read_data *data)
+static int nfs4_proc_read_rpc_prepare(struct rpc_task *task, struct nfs_read_data *data)
 {
 	if (nfs4_setup_sequence(NFS_SERVER(data->header->inode),
 			&data->args.seq_args,
 			&data->res.seq_res,
 			task))
-		return;
-	nfs4_set_rw_stateid(&data->args.stateid, data->args.context,
-			data->args.lock_context, FMODE_READ);
+		return 0;
+	if (nfs4_set_rw_stateid(&data->args.stateid, data->args.context,
+				data->args.lock_context, FMODE_READ) == -EIO)
+		return -EIO;
+	if (unlikely(test_bit(NFS_CONTEXT_BAD, &data->args.context->flags)))
+		return -EIO;
+	return 0;
 }
 
 static int nfs4_write_done_cb(struct rpc_task *task, struct nfs_write_data *data)
@@ -4112,15 +4116,19 @@ static void nfs4_proc_write_setup(struct nfs_write_data *data, struct rpc_messag
 	nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 1);
 }
 
-static void nfs4_proc_write_rpc_prepare(struct rpc_task *task, struct nfs_write_data *data)
+static int nfs4_proc_write_rpc_prepare(struct rpc_task *task, struct nfs_write_data *data)
 {
 	if (nfs4_setup_sequence(NFS_SERVER(data->header->inode),
 			&data->args.seq_args,
 			&data->res.seq_res,
 			task))
-		return;
-	nfs4_set_rw_stateid(&data->args.stateid, data->args.context,
-			data->args.lock_context, FMODE_WRITE);
+		return 0;
+	if (nfs4_set_rw_stateid(&data->args.stateid, data->args.context,
+				data->args.lock_context, FMODE_WRITE) == -EIO)
+		return -EIO;
+	if (unlikely(test_bit(NFS_CONTEXT_BAD, &data->args.context->flags)))
+		return -EIO;
+	return 0;
 }
 
 static void nfs4_proc_commit_rpc_prepare(struct rpc_task *task, struct nfs_commit_data *data)
@@ -5515,6 +5523,12 @@ static int nfs4_lock_reclaim(struct nfs4_state *state, struct file_lock *request
 	return err;
 }
 
+bool recover_locks = true;
+module_param(recover_locks, bool, 0644);
+MODULE_PARM_DESC(recover_locks,
+		 "If the server reports that a lock might be lost, "
+		 "try to recovery it risking corruption.");
+
 static int nfs4_lock_expired(struct nfs4_state *state, struct file_lock *request)
 {
 	struct nfs_server *server = NFS_SERVER(state->inode);
@@ -5526,6 +5540,10 @@ static int nfs4_lock_expired(struct nfs4_state *state, struct file_lock *request
 	err = nfs4_set_lock_state(state, request);
 	if (err != 0)
 		return err;
+	if (!recover_locks) {
+		set_bit(NFS_LOCK_LOST, &request->fl_u.nfs4_fl.owner->ls_flags);
+		return 0;
+	}
 	do {
 		if (test_bit(NFS_DELEGATED_STATE, &state->flags) != 0)
 			return 0;
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index da608ee8d5ffc6fd1d744c80fe33e339c91bc1fb..cc14cbb78b7322637ae74f6ad013c9183e7a996a 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -969,7 +969,9 @@ static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
 	fl_pid = lockowner->l_pid;
 	spin_lock(&state->state_lock);
 	lsp = __nfs4_find_lock_state(state, fl_owner, fl_pid, NFS4_ANY_LOCK_TYPE);
-	if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
+	if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
+		ret = -EIO;
+	else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
 		nfs4_stateid_copy(dst, &lsp->ls_stateid);
 		ret = 0;
 		smp_rmb();
@@ -1009,11 +1011,17 @@ static int nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
 int nfs4_select_rw_stateid(nfs4_stateid *dst, struct nfs4_state *state,
 		fmode_t fmode, const struct nfs_lockowner *lockowner)
 {
-	int ret = 0;
+	int ret = nfs4_copy_lock_stateid(dst, state, lockowner);
+	if (ret == -EIO)
+		/* A lost lock - don't even consider delegations */
+		goto out;
 	if (nfs4_copy_delegation_stateid(dst, state->inode, fmode))
 		goto out;
-	ret = nfs4_copy_lock_stateid(dst, state, lockowner);
 	if (ret != -ENOENT)
+		/* nfs4_copy_delegation_stateid() didn't over-write
+		 * dst, so it still has the lock stateid which we now
+		 * choose to use.
+		 */
 		goto out;
 	ret = nfs4_copy_open_stateid(dst, state);
 out:
diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index c041c41f7a52bcc849400bd55eae238c47b1ad0d..a8f57c728df561ac58e158c9fb46ca3b7c77004e 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -623,9 +623,10 @@ static void nfs_proc_read_setup(struct nfs_read_data *data, struct rpc_message *
 	msg->rpc_proc = &nfs_procedures[NFSPROC_READ];
 }
 
-static void nfs_proc_read_rpc_prepare(struct rpc_task *task, struct nfs_read_data *data)
+static int nfs_proc_read_rpc_prepare(struct rpc_task *task, struct nfs_read_data *data)
 {
 	rpc_call_start(task);
+	return 0;
 }
 
 static int nfs_write_done(struct rpc_task *task, struct nfs_write_data *data)
@@ -644,9 +645,10 @@ static void nfs_proc_write_setup(struct nfs_write_data *data, struct rpc_message
 	msg->rpc_proc = &nfs_procedures[NFSPROC_WRITE];
 }
 
-static void nfs_proc_write_rpc_prepare(struct rpc_task *task, struct nfs_write_data *data)
+static int nfs_proc_write_rpc_prepare(struct rpc_task *task, struct nfs_write_data *data)
 {
 	rpc_call_start(task);
+	return 0;
 }
 
 static void nfs_proc_commit_rpc_prepare(struct rpc_task *task, struct nfs_commit_data *data)
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 70a26c651f0952e596cebd8191f53c2ac937d939..31db5c366b816e4c18d806ae0ae80d0c9207905e 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -513,9 +513,10 @@ static void nfs_readpage_release_common(void *calldata)
 void nfs_read_prepare(struct rpc_task *task, void *calldata)
 {
 	struct nfs_read_data *data = calldata;
-	NFS_PROTO(data->header->inode)->read_rpc_prepare(task, data);
-	if (unlikely(test_bit(NFS_CONTEXT_BAD, &data->args.context->flags)))
-		rpc_exit(task, -EIO);
+	int err;
+	err = NFS_PROTO(data->header->inode)->read_rpc_prepare(task, data);
+	if (err)
+		rpc_exit(task, err);
 }
 
 static const struct rpc_call_ops nfs_read_common_ops = {
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 94eb4504731a5c82fedfcdd926c288ec257f0d9b..379450c8d04b027c7e19a6b11d5f8037f7405fc1 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1294,9 +1294,10 @@ EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds);
 void nfs_write_prepare(struct rpc_task *task, void *calldata)
 {
 	struct nfs_write_data *data = calldata;
-	NFS_PROTO(data->header->inode)->write_rpc_prepare(task, data);
-	if (unlikely(test_bit(NFS_CONTEXT_BAD, &data->args.context->flags)))
-		rpc_exit(task, -EIO);
+	int err;
+	err = NFS_PROTO(data->header->inode)->write_rpc_prepare(task, data);
+	if (err)
+		rpc_exit(task, err);
 }
 
 void nfs_commit_prepare(struct rpc_task *task, void *calldata)
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index ddc3e32178c31c3ec09f56a3263e85d8de55fdd2..7c3956d65b3ea151c9e4fcfd71c61ba968092cb2 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1419,12 +1419,12 @@ struct nfs_rpc_ops {
 	void	(*read_setup)   (struct nfs_read_data *, struct rpc_message *);
 	void	(*read_pageio_init)(struct nfs_pageio_descriptor *, struct inode *,
 				    const struct nfs_pgio_completion_ops *);
-	void	(*read_rpc_prepare)(struct rpc_task *, struct nfs_read_data *);
+	int	(*read_rpc_prepare)(struct rpc_task *, struct nfs_read_data *);
 	int	(*read_done)  (struct rpc_task *, struct nfs_read_data *);
 	void	(*write_setup)  (struct nfs_write_data *, struct rpc_message *);
 	void	(*write_pageio_init)(struct nfs_pageio_descriptor *, struct inode *, int,
 				     const struct nfs_pgio_completion_ops *);
-	void	(*write_rpc_prepare)(struct rpc_task *, struct nfs_write_data *);
+	int	(*write_rpc_prepare)(struct rpc_task *, struct nfs_write_data *);
 	int	(*write_done)  (struct rpc_task *, struct nfs_write_data *);
 	void	(*commit_setup) (struct nfs_commit_data *, struct rpc_message *);
 	void	(*commit_rpc_prepare)(struct rpc_task *, struct nfs_commit_data *);