Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

21 files changed, 8707 insertions, 0 deletions

diff --git a/fs/lockd/Makefile b/fs/lockd/Makefile
new file mode 100644
index 0000000000..ac9f9d8451
--- /dev/null
+++ b/fs/lockd/Makefile
@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux lock manager stuff
+#
+
+ccflags-y += -I$(src)			# needed for trace events
+
+obj-$(CONFIG_LOCKD) += lockd.o
+
+lockd-objs-y += clntlock.o clntproc.o clntxdr.o host.o svc.o svclock.o \
+	        svcshare.o svcproc.o svcsubs.o mon.o trace.o xdr.o
+lockd-objs-$(CONFIG_LOCKD_V4) += clnt4xdr.o xdr4.o svc4proc.o
+lockd-objs-$(CONFIG_PROC_FS) += procfs.o
+lockd-objs		      := $(lockd-objs-y)
diff --git a/fs/lockd/clnt4xdr.c b/fs/lockd/clnt4xdr.c
new file mode 100644
index 0000000000..8161667c97
--- /dev/null
+++ b/fs/lockd/clnt4xdr.c
@@ -0,0 +1,581 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/lockd/clnt4xdr.c
+ *
+ * XDR functions to encode/decode NLM version 4 RPC arguments and results.
+ *
+ * NLM client-side only.
+ *
+ * Copyright (C) 2010, Oracle.  All rights reserved.
+ */
+
+#include <linux/types.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/stats.h>
+#include <linux/lockd/lockd.h>
+
+#include <uapi/linux/nfs3.h>
+
+#define NLMDBG_FACILITY		NLMDBG_XDR
+
+#if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
+#  error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
+#endif
+
+#if (NLMCLNT_OHSIZE > NLM_MAXSTRLEN)
+#  error "NLM host name cannot be larger than NLM's maximum string length!"
+#endif
+
+/*
+ * Declare the space requirements for NLM arguments and replies as
+ * number of 32bit-words
+ */
+#define NLM4_void_sz		(0)
+#define NLM4_cookie_sz		(1+(NLM_MAXCOOKIELEN>>2))
+#define NLM4_caller_sz		(1+(NLMCLNT_OHSIZE>>2))
+#define NLM4_owner_sz		(1+(NLMCLNT_OHSIZE>>2))
+#define NLM4_fhandle_sz		(1+(NFS3_FHSIZE>>2))
+#define NLM4_lock_sz		(5+NLM4_caller_sz+NLM4_owner_sz+NLM4_fhandle_sz)
+#define NLM4_holder_sz		(6+NLM4_owner_sz)
+
+#define NLM4_testargs_sz	(NLM4_cookie_sz+1+NLM4_lock_sz)
+#define NLM4_lockargs_sz	(NLM4_cookie_sz+4+NLM4_lock_sz)
+#define NLM4_cancargs_sz	(NLM4_cookie_sz+2+NLM4_lock_sz)
+#define NLM4_unlockargs_sz	(NLM4_cookie_sz+NLM4_lock_sz)
+
+#define NLM4_testres_sz		(NLM4_cookie_sz+1+NLM4_holder_sz)
+#define NLM4_res_sz		(NLM4_cookie_sz+1)
+#define NLM4_norep_sz		(0)
+
+
+static s64 loff_t_to_s64(loff_t offset)
+{
+	s64 res;
+
+	if (offset >= NLM4_OFFSET_MAX)
+		res = NLM4_OFFSET_MAX;
+	else if (offset <= -NLM4_OFFSET_MAX)
+		res = -NLM4_OFFSET_MAX;
+	else
+		res = offset;
+	return res;
+}
+
+static void nlm4_compute_offsets(const struct nlm_lock *lock,
+				 u64 *l_offset, u64 *l_len)
+{
+	const struct file_lock *fl = &lock->fl;
+
+	*l_offset = loff_t_to_s64(fl->fl_start);
+	if (fl->fl_end == OFFSET_MAX)
+		*l_len = 0;
+	else
+		*l_len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
+}
+
+/*
+ * Encode/decode NLMv4 basic data types
+ *
+ * Basic NLMv4 data types are defined in Appendix II, section 6.1.4
+ * of RFC 1813: "NFS Version 3 Protocol Specification" and in Chapter
+ * 10 of X/Open's "Protocols for Interworking: XNFS, Version 3W".
+ *
+ * Not all basic data types have their own encoding and decoding
+ * functions.  For run-time efficiency, some data types are encoded
+ * or decoded inline.
+ */
+
+static void encode_bool(struct xdr_stream *xdr, const int value)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = value ? xdr_one : xdr_zero;
+}
+
+static void encode_int32(struct xdr_stream *xdr, const s32 value)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(value);
+}
+
+/*
+ *	typedef opaque netobj<MAXNETOBJ_SZ>
+ */
+static void encode_netobj(struct xdr_stream *xdr,
+			  const u8 *data, const unsigned int length)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4 + length);
+	xdr_encode_opaque(p, data, length);
+}
+
+static int decode_netobj(struct xdr_stream *xdr,
+			 struct xdr_netobj *obj)
+{
+	ssize_t ret;
+
+	ret = xdr_stream_decode_opaque_inline(xdr, (void *)&obj->data,
+						XDR_MAX_NETOBJ);
+	if (unlikely(ret < 0))
+		return -EIO;
+	obj->len = ret;
+	return 0;
+}
+
+/*
+ *	netobj cookie;
+ */
+static void encode_cookie(struct xdr_stream *xdr,
+			  const struct nlm_cookie *cookie)
+{
+	encode_netobj(xdr, (u8 *)&cookie->data, cookie->len);
+}
+
+static int decode_cookie(struct xdr_stream *xdr,
+			     struct nlm_cookie *cookie)
+{
+	u32 length;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	length = be32_to_cpup(p++);
+	/* apparently HPUX can return empty cookies */
+	if (length == 0)
+		goto out_hpux;
+	if (length > NLM_MAXCOOKIELEN)
+		goto out_size;
+	p = xdr_inline_decode(xdr, length);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	cookie->len = length;
+	memcpy(cookie->data, p, length);
+	return 0;
+out_hpux:
+	cookie->len = 4;
+	memset(cookie->data, 0, 4);
+	return 0;
+out_size:
+	dprintk("NFS: returned cookie was too long: %u\n", length);
+	return -EIO;
+out_overflow:
+	return -EIO;
+}
+
+/*
+ *	netobj fh;
+ */
+static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
+{
+	encode_netobj(xdr, (u8 *)&fh->data, fh->size);
+}
+
+/*
+ *	enum nlm4_stats {
+ *		NLM4_GRANTED = 0,
+ *		NLM4_DENIED = 1,
+ *		NLM4_DENIED_NOLOCKS = 2,
+ *		NLM4_BLOCKED = 3,
+ *		NLM4_DENIED_GRACE_PERIOD = 4,
+ *		NLM4_DEADLCK = 5,
+ *		NLM4_ROFS = 6,
+ *		NLM4_STALE_FH = 7,
+ *		NLM4_FBIG = 8,
+ *		NLM4_FAILED = 9
+ *	};
+ *
+ *	struct nlm4_stat {
+ *		nlm4_stats stat;
+ *	};
+ *
+ * NB: we don't swap bytes for the NLM status values.  The upper
+ * layers deal directly with the status value in network byte
+ * order.
+ */
+static void encode_nlm4_stat(struct xdr_stream *xdr,
+			     const __be32 stat)
+{
+	__be32 *p;
+
+	BUG_ON(be32_to_cpu(stat) > NLM_FAILED);
+	p = xdr_reserve_space(xdr, 4);
+	*p = stat;
+}
+
+static int decode_nlm4_stat(struct xdr_stream *xdr, __be32 *stat)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	if (unlikely(ntohl(*p) > ntohl(nlm4_failed)))
+		goto out_bad_xdr;
+	*stat = *p;
+	return 0;
+out_bad_xdr:
+	dprintk("%s: server returned invalid nlm4_stats value: %u\n",
+			__func__, be32_to_cpup(p));
+	return -EIO;
+out_overflow:
+	return -EIO;
+}
+
+/*
+ *	struct nlm4_holder {
+ *		bool	exclusive;
+ *		int32	svid;
+ *		netobj	oh;
+ *		uint64	l_offset;
+ *		uint64	l_len;
+ *	};
+ */
+static void encode_nlm4_holder(struct xdr_stream *xdr,
+			       const struct nlm_res *result)
+{
+	const struct nlm_lock *lock = &result->lock;
+	u64 l_offset, l_len;
+	__be32 *p;
+
+	encode_bool(xdr, lock->fl.fl_type == F_RDLCK);
+	encode_int32(xdr, lock->svid);
+	encode_netobj(xdr, lock->oh.data, lock->oh.len);
+
+	p = xdr_reserve_space(xdr, 4 + 4);
+	nlm4_compute_offsets(lock, &l_offset, &l_len);
+	p = xdr_encode_hyper(p, l_offset);
+	xdr_encode_hyper(p, l_len);
+}
+
+static int decode_nlm4_holder(struct xdr_stream *xdr, struct nlm_res *result)
+{
+	struct nlm_lock *lock = &result->lock;
+	struct file_lock *fl = &lock->fl;
+	u64 l_offset, l_len;
+	u32 exclusive;
+	int error;
+	__be32 *p;
+
+	memset(lock, 0, sizeof(*lock));
+	locks_init_lock(fl);
+
+	p = xdr_inline_decode(xdr, 4 + 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	exclusive = be32_to_cpup(p++);
+	lock->svid = be32_to_cpup(p);
+	fl->fl_pid = (pid_t)lock->svid;
+
+	error = decode_netobj(xdr, &lock->oh);
+	if (unlikely(error))
+		goto out;
+
+	p = xdr_inline_decode(xdr, 8 + 8);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+
+	fl->fl_flags = FL_POSIX;
+	fl->fl_type  = exclusive != 0 ? F_WRLCK : F_RDLCK;
+	p = xdr_decode_hyper(p, &l_offset);
+	xdr_decode_hyper(p, &l_len);
+	nlm4svc_set_file_lock_range(fl, l_offset, l_len);
+	error = 0;
+out:
+	return error;
+out_overflow:
+	return -EIO;
+}
+
+/*
+ *	string caller_name<LM_MAXSTRLEN>;
+ */
+static void encode_caller_name(struct xdr_stream *xdr, const char *name)
+{
+	/* NB: client-side does not set lock->len */
+	u32 length = strlen(name);
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4 + length);
+	xdr_encode_opaque(p, name, length);
+}
+
+/*
+ *	struct nlm4_lock {
+ *		string	caller_name<LM_MAXSTRLEN>;
+ *		netobj	fh;
+ *		netobj	oh;
+ *		int32	svid;
+ *		uint64	l_offset;
+ *		uint64	l_len;
+ *	};
+ */
+static void encode_nlm4_lock(struct xdr_stream *xdr,
+			     const struct nlm_lock *lock)
+{
+	u64 l_offset, l_len;
+	__be32 *p;
+
+	encode_caller_name(xdr, lock->caller);
+	encode_fh(xdr, &lock->fh);
+	encode_netobj(xdr, lock->oh.data, lock->oh.len);
+
+	p = xdr_reserve_space(xdr, 4 + 8 + 8);
+	*p++ = cpu_to_be32(lock->svid);
+
+	nlm4_compute_offsets(lock, &l_offset, &l_len);
+	p = xdr_encode_hyper(p, l_offset);
+	xdr_encode_hyper(p, l_len);
+}
+
+
+/*
+ * NLMv4 XDR encode functions
+ *
+ * NLMv4 argument types are defined in Appendix II of RFC 1813:
+ * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
+ * "Protocols for Interworking: XNFS, Version 3W".
+ */
+
+/*
+ *	struct nlm4_testargs {
+ *		netobj cookie;
+ *		bool exclusive;
+ *		struct nlm4_lock alock;
+ *	};
+ */
+static void nlm4_xdr_enc_testargs(struct rpc_rqst *req,
+				  struct xdr_stream *xdr,
+				  const void *data)
+{
+	const struct nlm_args *args = data;
+	const struct nlm_lock *lock = &args->lock;
+
+	encode_cookie(xdr, &args->cookie);
+	encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
+	encode_nlm4_lock(xdr, lock);
+}
+
+/*
+ *	struct nlm4_lockargs {
+ *		netobj cookie;
+ *		bool block;
+ *		bool exclusive;
+ *		struct nlm4_lock alock;
+ *		bool reclaim;
+ *		int state;
+ *	};
+ */
+static void nlm4_xdr_enc_lockargs(struct rpc_rqst *req,
+				  struct xdr_stream *xdr,
+				  const void *data)
+{
+	const struct nlm_args *args = data;
+	const struct nlm_lock *lock = &args->lock;
+
+	encode_cookie(xdr, &args->cookie);
+	encode_bool(xdr, args->block);
+	encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
+	encode_nlm4_lock(xdr, lock);
+	encode_bool(xdr, args->reclaim);
+	encode_int32(xdr, args->state);
+}
+
+/*
+ *	struct nlm4_cancargs {
+ *		netobj cookie;
+ *		bool block;
+ *		bool exclusive;
+ *		struct nlm4_lock alock;
+ *	};
+ */
+static void nlm4_xdr_enc_cancargs(struct rpc_rqst *req,
+				  struct xdr_stream *xdr,
+				  const void *data)
+{
+	const struct nlm_args *args = data;
+	const struct nlm_lock *lock = &args->lock;
+
+	encode_cookie(xdr, &args->cookie);
+	encode_bool(xdr, args->block);
+	encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
+	encode_nlm4_lock(xdr, lock);
+}
+
+/*
+ *	struct nlm4_unlockargs {
+ *		netobj cookie;
+ *		struct nlm4_lock alock;
+ *	};
+ */
+static void nlm4_xdr_enc_unlockargs(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    const void *data)
+{
+	const struct nlm_args *args = data;
+	const struct nlm_lock *lock = &args->lock;
+
+	encode_cookie(xdr, &args->cookie);
+	encode_nlm4_lock(xdr, lock);
+}
+
+/*
+ *	struct nlm4_res {
+ *		netobj cookie;
+ *		nlm4_stat stat;
+ *	};
+ */
+static void nlm4_xdr_enc_res(struct rpc_rqst *req,
+			     struct xdr_stream *xdr,
+			     const void *data)
+{
+	const struct nlm_res *result = data;
+
+	encode_cookie(xdr, &result->cookie);
+	encode_nlm4_stat(xdr, result->status);
+}
+
+/*
+ *	union nlm4_testrply switch (nlm4_stats stat) {
+ *	case NLM4_DENIED:
+ *		struct nlm4_holder holder;
+ *	default:
+ *		void;
+ *	};
+ *
+ *	struct nlm4_testres {
+ *		netobj cookie;
+ *		nlm4_testrply test_stat;
+ *	};
+ */
+static void nlm4_xdr_enc_testres(struct rpc_rqst *req,
+				 struct xdr_stream *xdr,
+				 const void *data)
+{
+	const struct nlm_res *result = data;
+
+	encode_cookie(xdr, &result->cookie);
+	encode_nlm4_stat(xdr, result->status);
+	if (result->status == nlm_lck_denied)
+		encode_nlm4_holder(xdr, result);
+}
+
+
+/*
+ * NLMv4 XDR decode functions
+ *
+ * NLMv4 argument types are defined in Appendix II of RFC 1813:
+ * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
+ * "Protocols for Interworking: XNFS, Version 3W".
+ */
+
+/*
+ *	union nlm4_testrply switch (nlm4_stats stat) {
+ *	case NLM4_DENIED:
+ *		struct nlm4_holder holder;
+ *	default:
+ *		void;
+ *	};
+ *
+ *	struct nlm4_testres {
+ *		netobj cookie;
+ *		nlm4_testrply test_stat;
+ *	};
+ */
+static int decode_nlm4_testrply(struct xdr_stream *xdr,
+				struct nlm_res *result)
+{
+	int error;
+
+	error = decode_nlm4_stat(xdr, &result->status);
+	if (unlikely(error))
+		goto out;
+	if (result->status == nlm_lck_denied)
+		error = decode_nlm4_holder(xdr, result);
+out:
+	return error;
+}
+
+static int nlm4_xdr_dec_testres(struct rpc_rqst *req,
+				struct xdr_stream *xdr,
+				void *data)
+{
+	struct nlm_res *result = data;
+	int error;
+
+	error = decode_cookie(xdr, &result->cookie);
+	if (unlikely(error))
+		goto out;
+	error = decode_nlm4_testrply(xdr, result);
+out:
+	return error;
+}
+
+/*
+ *	struct nlm4_res {
+ *		netobj cookie;
+ *		nlm4_stat stat;
+ *	};
+ */
+static int nlm4_xdr_dec_res(struct rpc_rqst *req,
+			    struct xdr_stream *xdr,
+			    void *data)
+{
+	struct nlm_res *result = data;
+	int error;
+
+	error = decode_cookie(xdr, &result->cookie);
+	if (unlikely(error))
+		goto out;
+	error = decode_nlm4_stat(xdr, &result->status);
+out:
+	return error;
+}
+
+
+/*
+ * For NLM, a void procedure really returns nothing
+ */
+#define nlm4_xdr_dec_norep	NULL
+
+#define PROC(proc, argtype, restype)					\
+[NLMPROC_##proc] = {							\
+	.p_proc      = NLMPROC_##proc,					\
+	.p_encode    = nlm4_xdr_enc_##argtype,				\
+	.p_decode    = nlm4_xdr_dec_##restype,				\
+	.p_arglen    = NLM4_##argtype##_sz,				\
+	.p_replen    = NLM4_##restype##_sz,				\
+	.p_statidx   = NLMPROC_##proc,					\
+	.p_name      = #proc,						\
+	}
+
+static const struct rpc_procinfo nlm4_procedures[] = {
+	PROC(TEST,		testargs,	testres),
+	PROC(LOCK,		lockargs,	res),
+	PROC(CANCEL,		cancargs,	res),
+	PROC(UNLOCK,		unlockargs,	res),
+	PROC(GRANTED,		testargs,	res),
+	PROC(TEST_MSG,		testargs,	norep),
+	PROC(LOCK_MSG,		lockargs,	norep),
+	PROC(CANCEL_MSG,	cancargs,	norep),
+	PROC(UNLOCK_MSG,	unlockargs,	norep),
+	PROC(GRANTED_MSG,	testargs,	norep),
+	PROC(TEST_RES,		testres,	norep),
+	PROC(LOCK_RES,		res,		norep),
+	PROC(CANCEL_RES,	res,		norep),
+	PROC(UNLOCK_RES,	res,		norep),
+	PROC(GRANTED_RES,	res,		norep),
+};
+
+static unsigned int nlm_version4_counts[ARRAY_SIZE(nlm4_procedures)];
+const struct rpc_version nlm_version4 = {
+	.number		= 4,
+	.nrprocs	= ARRAY_SIZE(nlm4_procedures),
+	.procs		= nlm4_procedures,
+	.counts		= nlm_version4_counts,
+};
diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
new file mode 100644
index 0000000000..5d85715be7
--- /dev/null
+++ b/fs/lockd/clntlock.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/fs/lockd/clntlock.c
+ *
+ * Lock handling for the client side NLM implementation
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/nfs_fs.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include <linux/lockd/lockd.h>
+#include <linux/kthread.h>
+
+#include "trace.h"
+
+#define NLMDBG_FACILITY		NLMDBG_CLIENT
+
+/*
+ * Local function prototypes
+ */
+static int			reclaimer(void *ptr);
+
+/*
+ * The following functions handle blocking and granting from the
+ * client perspective.
+ */
+
+static LIST_HEAD(nlm_blocked);
+static DEFINE_SPINLOCK(nlm_blocked_lock);
+
+/**
+ * nlmclnt_init - Set up per-NFS mount point lockd data structures
+ * @nlm_init: pointer to arguments structure
+ *
+ * Returns pointer to an appropriate nlm_host struct,
+ * or an ERR_PTR value.
+ */
+struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init)
+{
+	struct nlm_host *host;
+	u32 nlm_version = (nlm_init->nfs_version == 2) ? 1 : 4;
+	int status;
+
+	status = lockd_up(nlm_init->net, nlm_init->cred);
+	if (status < 0)
+		return ERR_PTR(status);
+
+	host = nlmclnt_lookup_host(nlm_init->address, nlm_init->addrlen,
+				   nlm_init->protocol, nlm_version,
+				   nlm_init->hostname, nlm_init->noresvport,
+				   nlm_init->net, nlm_init->cred);
+	if (host == NULL)
+		goto out_nohost;
+	if (host->h_rpcclnt == NULL && nlm_bind_host(host) == NULL)
+		goto out_nobind;
+
+	host->h_nlmclnt_ops = nlm_init->nlmclnt_ops;
+	return host;
+out_nobind:
+	nlmclnt_release_host(host);
+out_nohost:
+	lockd_down(nlm_init->net);
+	return ERR_PTR(-ENOLCK);
+}
+EXPORT_SYMBOL_GPL(nlmclnt_init);
+
+/**
+ * nlmclnt_done - Release resources allocated by nlmclnt_init()
+ * @host: nlm_host structure reserved by nlmclnt_init()
+ *
+ */
+void nlmclnt_done(struct nlm_host *host)
+{
+	struct net *net = host->net;
+
+	nlmclnt_release_host(host);
+	lockd_down(net);
+}
+EXPORT_SYMBOL_GPL(nlmclnt_done);
+
+void nlmclnt_prepare_block(struct nlm_wait *block, struct nlm_host *host, struct file_lock *fl)
+{
+	block->b_host = host;
+	block->b_lock = fl;
+	init_waitqueue_head(&block->b_wait);
+	block->b_status = nlm_lck_blocked;
+}
+
+struct rpc_clnt *nlmclnt_rpc_clnt(struct nlm_host *host)
+{
+	return host->h_rpcclnt;
+}
+EXPORT_SYMBOL_GPL(nlmclnt_rpc_clnt);
+
+/*
+ * Queue up a lock for blocking so that the GRANTED request can see it
+ */
+void nlmclnt_queue_block(struct nlm_wait *block)
+{
+	spin_lock(&nlm_blocked_lock);
+	list_add(&block->b_list, &nlm_blocked);
+	spin_unlock(&nlm_blocked_lock);
+}
+
+/*
+ * Dequeue the block and return its final status
+ */
+__be32 nlmclnt_dequeue_block(struct nlm_wait *block)
+{
+	__be32 status;
+
+	spin_lock(&nlm_blocked_lock);
+	list_del(&block->b_list);
+	status = block->b_status;
+	spin_unlock(&nlm_blocked_lock);
+	return status;
+}
+
+/*
+ * Block on a lock
+ */
+int nlmclnt_wait(struct nlm_wait *block, struct nlm_rqst *req, long timeout)
+{
+	long ret;
+
+	/* A borken server might ask us to block even if we didn't
+	 * request it. Just say no!
+	 */
+	if (block == NULL)
+		return -EAGAIN;
+
+	/* Go to sleep waiting for GRANT callback. Some servers seem
+	 * to lose callbacks, however, so we're going to poll from
+	 * time to time just to make sure.
+	 *
+	 * For now, the retry frequency is pretty high; normally 
+	 * a 1 minute timeout would do. See the comment before
+	 * nlmclnt_lock for an explanation.
+	 */
+	ret = wait_event_interruptible_timeout(block->b_wait,
+			block->b_status != nlm_lck_blocked,
+			timeout);
+	if (ret < 0)
+		return -ERESTARTSYS;
+	/* Reset the lock status after a server reboot so we resend */
+	if (block->b_status == nlm_lck_denied_grace_period)
+		block->b_status = nlm_lck_blocked;
+	return 0;
+}
+
+/*
+ * The server lockd has called us back to tell us the lock was granted
+ */
+__be32 nlmclnt_grant(const struct sockaddr *addr, const struct nlm_lock *lock)
+{
+	const struct file_lock *fl = &lock->fl;
+	const struct nfs_fh *fh = &lock->fh;
+	struct nlm_wait	*block;
+	__be32 res = nlm_lck_denied;
+
+	/*
+	 * Look up blocked request based on arguments. 
+	 * Warning: must not use cookie to match it!
+	 */
+	spin_lock(&nlm_blocked_lock);
+	list_for_each_entry(block, &nlm_blocked, b_list) {
+		struct file_lock *fl_blocked = block->b_lock;
+
+		if (fl_blocked->fl_start != fl->fl_start)
+			continue;
+		if (fl_blocked->fl_end != fl->fl_end)
+			continue;
+		/*
+		 * Careful! The NLM server will return the 32-bit "pid" that
+		 * we put on the wire: in this case the lockowner "pid".
+		 */
+		if (fl_blocked->fl_u.nfs_fl.owner->pid != lock->svid)
+			continue;
+		if (!rpc_cmp_addr(nlm_addr(block->b_host), addr))
+			continue;
+		if (nfs_compare_fh(NFS_FH(file_inode(fl_blocked->fl_file)), fh) != 0)
+			continue;
+		/* Alright, we found a lock. Set the return status
+		 * and wake up the caller
+		 */
+		block->b_status = nlm_granted;
+		wake_up(&block->b_wait);
+		res = nlm_granted;
+	}
+	spin_unlock(&nlm_blocked_lock);
+	trace_nlmclnt_grant(lock, addr, svc_addr_len(addr), res);
+	return res;
+}
+
+/*
+ * The following procedures deal with the recovery of locks after a
+ * server crash.
+ */
+
+/*
+ * Reclaim all locks on server host. We do this by spawning a separate
+ * reclaimer thread.
+ */
+void
+nlmclnt_recovery(struct nlm_host *host)
+{
+	struct task_struct *task;
+
+	if (!host->h_reclaiming++) {
+		nlm_get_host(host);
+		task = kthread_run(reclaimer, host, "%s-reclaim", host->h_name);
+		if (IS_ERR(task))
+			printk(KERN_ERR "lockd: unable to spawn reclaimer "
+				"thread. Locks for %s won't be reclaimed! "
+				"(%ld)\n", host->h_name, PTR_ERR(task));
+	}
+}
+
+static int
+reclaimer(void *ptr)
+{
+	struct nlm_host	  *host = (struct nlm_host *) ptr;
+	struct nlm_wait	  *block;
+	struct nlm_rqst   *req;
+	struct file_lock *fl, *next;
+	u32 nsmstate;
+	struct net *net = host->net;
+
+	req = kmalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return 0;
+
+	allow_signal(SIGKILL);
+
+	down_write(&host->h_rwsem);
+	lockd_up(net, NULL);	/* note: this cannot fail as lockd is already running */
+
+	dprintk("lockd: reclaiming locks for host %s\n", host->h_name);
+
+restart:
+	nsmstate = host->h_nsmstate;
+
+	/* Force a portmap getport - the peer's lockd will
+	 * most likely end up on a different port.
+	 */
+	host->h_nextrebind = jiffies;
+	nlm_rebind_host(host);
+
+	/* First, reclaim all locks that have been granted. */
+	list_splice_init(&host->h_granted, &host->h_reclaim);
+	list_for_each_entry_safe(fl, next, &host->h_reclaim, fl_u.nfs_fl.list) {
+		list_del_init(&fl->fl_u.nfs_fl.list);
+
+		/*
+		 * sending this thread a SIGKILL will result in any unreclaimed
+		 * locks being removed from the h_granted list. This means that
+		 * the kernel will not attempt to reclaim them again if a new
+		 * reclaimer thread is spawned for this host.
+		 */
+		if (signalled())
+			continue;
+		if (nlmclnt_reclaim(host, fl, req) != 0)
+			continue;
+		list_add_tail(&fl->fl_u.nfs_fl.list, &host->h_granted);
+		if (host->h_nsmstate != nsmstate) {
+			/* Argh! The server rebooted again! */
+			goto restart;
+		}
+	}
+
+	host->h_reclaiming = 0;
+	up_write(&host->h_rwsem);
+	dprintk("NLM: done reclaiming locks for host %s\n", host->h_name);
+
+	/* Now, wake up all processes that sleep on a blocked lock */
+	spin_lock(&nlm_blocked_lock);
+	list_for_each_entry(block, &nlm_blocked, b_list) {
+		if (block->b_host == host) {
+			block->b_status = nlm_lck_denied_grace_period;
+			wake_up(&block->b_wait);
+		}
+	}
+	spin_unlock(&nlm_blocked_lock);
+
+	/* Release host handle after use */
+	nlmclnt_release_host(host);
+	lockd_down(net);
+	kfree(req);
+	return 0;
+}
diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
new file mode 100644
index 0000000000..fba6c7fa74
--- /dev/null
+++ b/fs/lockd/clntproc.c
@@ -0,0 +1,884 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/fs/lockd/clntproc.c
+ *
+ * RPC procedures for the client side NLM implementation
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/filelock.h>
+#include <linux/nfs_fs.h>
+#include <linux/utsname.h>
+#include <linux/freezer.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/lockd/lockd.h>
+
+#include "trace.h"
+
+#define NLMDBG_FACILITY		NLMDBG_CLIENT
+#define NLMCLNT_GRACE_WAIT	(5*HZ)
+#define NLMCLNT_POLL_TIMEOUT	(30*HZ)
+#define NLMCLNT_MAX_RETRIES	3
+
+static int	nlmclnt_test(struct nlm_rqst *, struct file_lock *);
+static int	nlmclnt_lock(struct nlm_rqst *, struct file_lock *);
+static int	nlmclnt_unlock(struct nlm_rqst *, struct file_lock *);
+static int	nlm_stat_to_errno(__be32 stat);
+static void	nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host);
+static int	nlmclnt_cancel(struct nlm_host *, int , struct file_lock *);
+
+static const struct rpc_call_ops nlmclnt_unlock_ops;
+static const struct rpc_call_ops nlmclnt_cancel_ops;
+
+/*
+ * Cookie counter for NLM requests
+ */
+static atomic_t	nlm_cookie = ATOMIC_INIT(0x1234);
+
+void nlmclnt_next_cookie(struct nlm_cookie *c)
+{
+	u32	cookie = atomic_inc_return(&nlm_cookie);
+
+	memcpy(c->data, &cookie, 4);
+	c->len=4;
+}
+
+static struct nlm_lockowner *
+nlmclnt_get_lockowner(struct nlm_lockowner *lockowner)
+{
+	refcount_inc(&lockowner->count);
+	return lockowner;
+}
+
+static void nlmclnt_put_lockowner(struct nlm_lockowner *lockowner)
+{
+	if (!refcount_dec_and_lock(&lockowner->count, &lockowner->host->h_lock))
+		return;
+	list_del(&lockowner->list);
+	spin_unlock(&lockowner->host->h_lock);
+	nlmclnt_release_host(lockowner->host);
+	kfree(lockowner);
+}
+
+static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid)
+{
+	struct nlm_lockowner *lockowner;
+	list_for_each_entry(lockowner, &host->h_lockowners, list) {
+		if (lockowner->pid == pid)
+			return -EBUSY;
+	}
+	return 0;
+}
+
+static inline uint32_t __nlm_alloc_pid(struct nlm_host *host)
+{
+	uint32_t res;
+	do {
+		res = host->h_pidcount++;
+	} while (nlm_pidbusy(host, res) < 0);
+	return res;
+}
+
+static struct nlm_lockowner *__nlmclnt_find_lockowner(struct nlm_host *host, fl_owner_t owner)
+{
+	struct nlm_lockowner *lockowner;
+	list_for_each_entry(lockowner, &host->h_lockowners, list) {
+		if (lockowner->owner != owner)
+			continue;
+		return nlmclnt_get_lockowner(lockowner);
+	}
+	return NULL;
+}
+
+static struct nlm_lockowner *nlmclnt_find_lockowner(struct nlm_host *host, fl_owner_t owner)
+{
+	struct nlm_lockowner *res, *new = NULL;
+
+	spin_lock(&host->h_lock);
+	res = __nlmclnt_find_lockowner(host, owner);
+	if (res == NULL) {
+		spin_unlock(&host->h_lock);
+		new = kmalloc(sizeof(*new), GFP_KERNEL);
+		spin_lock(&host->h_lock);
+		res = __nlmclnt_find_lockowner(host, owner);
+		if (res == NULL && new != NULL) {
+			res = new;
+			refcount_set(&new->count, 1);
+			new->owner = owner;
+			new->pid = __nlm_alloc_pid(host);
+			new->host = nlm_get_host(host);
+			list_add(&new->list, &host->h_lockowners);
+			new = NULL;
+		}
+	}
+	spin_unlock(&host->h_lock);
+	kfree(new);
+	return res;
+}
+
+/*
+ * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls
+ */
+static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl)
+{
+	struct nlm_args	*argp = &req->a_args;
+	struct nlm_lock	*lock = &argp->lock;
+	char *nodename = req->a_host->h_rpcclnt->cl_nodename;
+
+	nlmclnt_next_cookie(&argp->cookie);
+	memcpy(&lock->fh, NFS_FH(file_inode(fl->fl_file)), sizeof(struct nfs_fh));
+	lock->caller  = nodename;
+	lock->oh.data = req->a_owner;
+	lock->oh.len  = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s",
+				(unsigned int)fl->fl_u.nfs_fl.owner->pid,
+				nodename);
+	lock->svid = fl->fl_u.nfs_fl.owner->pid;
+	lock->fl.fl_start = fl->fl_start;
+	lock->fl.fl_end = fl->fl_end;
+	lock->fl.fl_type = fl->fl_type;
+}
+
+static void nlmclnt_release_lockargs(struct nlm_rqst *req)
+{
+	WARN_ON_ONCE(req->a_args.lock.fl.fl_ops != NULL);
+}
+
+/**
+ * nlmclnt_proc - Perform a single client-side lock request
+ * @host: address of a valid nlm_host context representing the NLM server
+ * @cmd: fcntl-style file lock operation to perform
+ * @fl: address of arguments for the lock operation
+ * @data: address of data to be sent to callback operations
+ *
+ */
+int nlmclnt_proc(struct nlm_host *host, int cmd, struct file_lock *fl, void *data)
+{
+	struct nlm_rqst		*call;
+	int			status;
+	const struct nlmclnt_operations *nlmclnt_ops = host->h_nlmclnt_ops;
+
+	call = nlm_alloc_call(host);
+	if (call == NULL)
+		return -ENOMEM;
+
+	if (nlmclnt_ops && nlmclnt_ops->nlmclnt_alloc_call)
+		nlmclnt_ops->nlmclnt_alloc_call(data);
+
+	nlmclnt_locks_init_private(fl, host);
+	if (!fl->fl_u.nfs_fl.owner) {
+		/* lockowner allocation has failed */
+		nlmclnt_release_call(call);
+		return -ENOMEM;
+	}
+	/* Set up the argument struct */
+	nlmclnt_setlockargs(call, fl);
+	call->a_callback_data = data;
+
+	if (IS_SETLK(cmd) || IS_SETLKW(cmd)) {
+		if (fl->fl_type != F_UNLCK) {
+			call->a_args.block = IS_SETLKW(cmd) ? 1 : 0;
+			status = nlmclnt_lock(call, fl);
+		} else
+			status = nlmclnt_unlock(call, fl);
+	} else if (IS_GETLK(cmd))
+		status = nlmclnt_test(call, fl);
+	else
+		status = -EINVAL;
+	fl->fl_ops->fl_release_private(fl);
+	fl->fl_ops = NULL;
+
+	dprintk("lockd: clnt proc returns %d\n", status);
+	return status;
+}
+EXPORT_SYMBOL_GPL(nlmclnt_proc);
+
+/*
+ * Allocate an NLM RPC call struct
+ */
+struct nlm_rqst *nlm_alloc_call(struct nlm_host *host)
+{
+	struct nlm_rqst	*call;
+
+	for(;;) {
+		call = kzalloc(sizeof(*call), GFP_KERNEL);
+		if (call != NULL) {
+			refcount_set(&call->a_count, 1);
+			locks_init_lock(&call->a_args.lock.fl);
+			locks_init_lock(&call->a_res.lock.fl);
+			call->a_host = nlm_get_host(host);
+			return call;
+		}
+		if (signalled())
+			break;
+		printk("nlm_alloc_call: failed, waiting for memory\n");
+		schedule_timeout_interruptible(5*HZ);
+	}
+	return NULL;
+}
+
+void nlmclnt_release_call(struct nlm_rqst *call)
+{
+	const struct nlmclnt_operations *nlmclnt_ops = call->a_host->h_nlmclnt_ops;
+
+	if (!refcount_dec_and_test(&call->a_count))
+		return;
+	if (nlmclnt_ops && nlmclnt_ops->nlmclnt_release_call)
+		nlmclnt_ops->nlmclnt_release_call(call->a_callback_data);
+	nlmclnt_release_host(call->a_host);
+	nlmclnt_release_lockargs(call);
+	kfree(call);
+}
+
+static void nlmclnt_rpc_release(void *data)
+{
+	nlmclnt_release_call(data);
+}
+
+static int nlm_wait_on_grace(wait_queue_head_t *queue)
+{
+	DEFINE_WAIT(wait);
+	int status = -EINTR;
+
+	prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE);
+	if (!signalled ()) {
+		schedule_timeout(NLMCLNT_GRACE_WAIT);
+		try_to_freeze();
+		if (!signalled ())
+			status = 0;
+	}
+	finish_wait(queue, &wait);
+	return status;
+}
+
+/*
+ * Generic NLM call
+ */
+static int
+nlmclnt_call(const struct cred *cred, struct nlm_rqst *req, u32 proc)
+{
+	struct nlm_host	*host = req->a_host;
+	struct rpc_clnt	*clnt;
+	struct nlm_args	*argp = &req->a_args;
+	struct nlm_res	*resp = &req->a_res;
+	struct rpc_message msg = {
+		.rpc_argp	= argp,
+		.rpc_resp	= resp,
+		.rpc_cred	= cred,
+	};
+	int		status;
+
+	dprintk("lockd: call procedure %d on %s\n",
+			(int)proc, host->h_name);
+
+	do {
+		if (host->h_reclaiming && !argp->reclaim)
+			goto in_grace_period;
+
+		/* If we have no RPC client yet, create one. */
+		if ((clnt = nlm_bind_host(host)) == NULL)
+			return -ENOLCK;
+		msg.rpc_proc = &clnt->cl_procinfo[proc];
+
+		/* Perform the RPC call. If an error occurs, try again */
+		if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) {
+			dprintk("lockd: rpc_call returned error %d\n", -status);
+			switch (status) {
+			case -EPROTONOSUPPORT:
+				status = -EINVAL;
+				break;
+			case -ECONNREFUSED:
+			case -ETIMEDOUT:
+			case -ENOTCONN:
+				nlm_rebind_host(host);
+				status = -EAGAIN;
+				break;
+			case -ERESTARTSYS:
+				return signalled () ? -EINTR : status;
+			default:
+				break;
+			}
+			break;
+		} else
+		if (resp->status == nlm_lck_denied_grace_period) {
+			dprintk("lockd: server in grace period\n");
+			if (argp->reclaim) {
+				printk(KERN_WARNING
+				     "lockd: spurious grace period reject?!\n");
+				return -ENOLCK;
+			}
+		} else {
+			if (!argp->reclaim) {
+				/* We appear to be out of the grace period */
+				wake_up_all(&host->h_gracewait);
+			}
+			dprintk("lockd: server returns status %d\n",
+				ntohl(resp->status));
+			return 0;	/* Okay, call complete */
+		}
+
+in_grace_period:
+		/*
+		 * The server has rebooted and appears to be in the grace
+		 * period during which locks are only allowed to be
+		 * reclaimed.
+		 * We can only back off and try again later.
+		 */
+		status = nlm_wait_on_grace(&host->h_gracewait);
+	} while (status == 0);
+
+	return status;
+}
+
+/*
+ * Generic NLM call, async version.
+ */
+static struct rpc_task *__nlm_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops)
+{
+	struct nlm_host	*host = req->a_host;
+	struct rpc_clnt	*clnt;
+	struct rpc_task_setup task_setup_data = {
+		.rpc_message = msg,
+		.callback_ops = tk_ops,
+		.callback_data = req,
+		.flags = RPC_TASK_ASYNC,
+	};
+
+	dprintk("lockd: call procedure %d on %s (async)\n",
+			(int)proc, host->h_name);
+
+	/* If we have no RPC client yet, create one. */
+	clnt = nlm_bind_host(host);
+	if (clnt == NULL)
+		goto out_err;
+	msg->rpc_proc = &clnt->cl_procinfo[proc];
+	task_setup_data.rpc_client = clnt;
+
+        /* bootstrap and kick off the async RPC call */
+	return rpc_run_task(&task_setup_data);
+out_err:
+	tk_ops->rpc_release(req);
+	return ERR_PTR(-ENOLCK);
+}
+
+static int nlm_do_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops)
+{
+	struct rpc_task *task;
+
+	task = __nlm_async_call(req, proc, msg, tk_ops);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	rpc_put_task(task);
+	return 0;
+}
+
+/*
+ * NLM asynchronous call.
+ */
+int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
+{
+	struct rpc_message msg = {
+		.rpc_argp	= &req->a_args,
+		.rpc_resp	= &req->a_res,
+	};
+	return nlm_do_async_call(req, proc, &msg, tk_ops);
+}
+
+int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
+{
+	struct rpc_message msg = {
+		.rpc_argp	= &req->a_res,
+	};
+	return nlm_do_async_call(req, proc, &msg, tk_ops);
+}
+
+/*
+ * NLM client asynchronous call.
+ *
+ * Note that although the calls are asynchronous, and are therefore
+ *      guaranteed to complete, we still always attempt to wait for
+ *      completion in order to be able to correctly track the lock
+ *      state.
+ */
+static int nlmclnt_async_call(const struct cred *cred, struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
+{
+	struct rpc_message msg = {
+		.rpc_argp	= &req->a_args,
+		.rpc_resp	= &req->a_res,
+		.rpc_cred	= cred,
+	};
+	struct rpc_task *task;
+	int err;
+
+	task = __nlm_async_call(req, proc, &msg, tk_ops);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	err = rpc_wait_for_completion_task(task);
+	rpc_put_task(task);
+	return err;
+}
+
+/*
+ * TEST for the presence of a conflicting lock
+ */
+static int
+nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
+{
+	int	status;
+
+	status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_TEST);
+	if (status < 0)
+		goto out;
+
+	switch (req->a_res.status) {
+		case nlm_granted:
+			fl->fl_type = F_UNLCK;
+			break;
+		case nlm_lck_denied:
+			/*
+			 * Report the conflicting lock back to the application.
+			 */
+			fl->fl_start = req->a_res.lock.fl.fl_start;
+			fl->fl_end = req->a_res.lock.fl.fl_end;
+			fl->fl_type = req->a_res.lock.fl.fl_type;
+			fl->fl_pid = -req->a_res.lock.fl.fl_pid;
+			break;
+		default:
+			status = nlm_stat_to_errno(req->a_res.status);
+	}
+out:
+	trace_nlmclnt_test(&req->a_args.lock,
+			   (const struct sockaddr *)&req->a_host->h_addr,
+			   req->a_host->h_addrlen, req->a_res.status);
+	nlmclnt_release_call(req);
+	return status;
+}
+
+static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
+{
+	spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock);
+	new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state;
+	new->fl_u.nfs_fl.owner = nlmclnt_get_lockowner(fl->fl_u.nfs_fl.owner);
+	list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted);
+	spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock);
+}
+
+static void nlmclnt_locks_release_private(struct file_lock *fl)
+{
+	spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock);
+	list_del(&fl->fl_u.nfs_fl.list);
+	spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock);
+	nlmclnt_put_lockowner(fl->fl_u.nfs_fl.owner);
+}
+
+static const struct file_lock_operations nlmclnt_lock_ops = {
+	.fl_copy_lock = nlmclnt_locks_copy_lock,
+	.fl_release_private = nlmclnt_locks_release_private,
+};
+
+static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host)
+{
+	fl->fl_u.nfs_fl.state = 0;
+	fl->fl_u.nfs_fl.owner = nlmclnt_find_lockowner(host, fl->fl_owner);
+	INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list);
+	fl->fl_ops = &nlmclnt_lock_ops;
+}
+
+static int do_vfs_lock(struct file_lock *fl)
+{
+	return locks_lock_file_wait(fl->fl_file, fl);
+}
+
+/*
+ * LOCK: Try to create a lock
+ *
+ *			Programmer Harassment Alert
+ *
+ * When given a blocking lock request in a sync RPC call, the HPUX lockd
+ * will faithfully return LCK_BLOCKED but never cares to notify us when
+ * the lock could be granted. This way, our local process could hang
+ * around forever waiting for the callback.
+ *
+ *  Solution A:	Implement busy-waiting
+ *  Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES})
+ *
+ * For now I am implementing solution A, because I hate the idea of
+ * re-implementing lockd for a third time in two months. The async
+ * calls shouldn't be too hard to do, however.
+ *
+ * This is one of the lovely things about standards in the NFS area:
+ * they're so soft and squishy you can't really blame HP for doing this.
+ */
+static int
+nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
+{
+	const struct cred *cred = nfs_file_cred(fl->fl_file);
+	struct nlm_host	*host = req->a_host;
+	struct nlm_res	*resp = &req->a_res;
+	struct nlm_wait block;
+	unsigned char fl_flags = fl->fl_flags;
+	unsigned char fl_type;
+	__be32 b_status;
+	int status = -ENOLCK;
+
+	if (nsm_monitor(host) < 0)
+		goto out;
+	req->a_args.state = nsm_local_state;
+
+	fl->fl_flags |= FL_ACCESS;
+	status = do_vfs_lock(fl);
+	fl->fl_flags = fl_flags;
+	if (status < 0)
+		goto out;
+
+	nlmclnt_prepare_block(&block, host, fl);
+again:
+	/*
+	 * Initialise resp->status to a valid non-zero value,
+	 * since 0 == nlm_lck_granted
+	 */
+	resp->status = nlm_lck_blocked;
+
+	/*
+	 * A GRANTED callback can come at any time -- even before the reply
+	 * to the LOCK request arrives, so we queue the wait before
+	 * requesting the lock.
+	 */
+	nlmclnt_queue_block(&block);
+	for (;;) {
+		/* Reboot protection */
+		fl->fl_u.nfs_fl.state = host->h_state;
+		status = nlmclnt_call(cred, req, NLMPROC_LOCK);
+		if (status < 0)
+			break;
+		/* Did a reclaimer thread notify us of a server reboot? */
+		if (resp->status == nlm_lck_denied_grace_period)
+			continue;
+		if (resp->status != nlm_lck_blocked)
+			break;
+		/* Wait on an NLM blocking lock */
+		status = nlmclnt_wait(&block, req, NLMCLNT_POLL_TIMEOUT);
+		if (status < 0)
+			break;
+		if (block.b_status != nlm_lck_blocked)
+			break;
+	}
+	b_status = nlmclnt_dequeue_block(&block);
+	if (resp->status == nlm_lck_blocked)
+		resp->status = b_status;
+
+	/* if we were interrupted while blocking, then cancel the lock request
+	 * and exit
+	 */
+	if (resp->status == nlm_lck_blocked) {
+		if (!req->a_args.block)
+			goto out_unlock;
+		if (nlmclnt_cancel(host, req->a_args.block, fl) == 0)
+			goto out;
+	}
+
+	if (resp->status == nlm_granted) {
+		down_read(&host->h_rwsem);
+		/* Check whether or not the server has rebooted */
+		if (fl->fl_u.nfs_fl.state != host->h_state) {
+			up_read(&host->h_rwsem);
+			goto again;
+		}
+		/* Ensure the resulting lock will get added to granted list */
+		fl->fl_flags |= FL_SLEEP;
+		if (do_vfs_lock(fl) < 0)
+			printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __func__);
+		up_read(&host->h_rwsem);
+		fl->fl_flags = fl_flags;
+		status = 0;
+	}
+	if (status < 0)
+		goto out_unlock;
+	/*
+	 * EAGAIN doesn't make sense for sleeping locks, and in some
+	 * cases NLM_LCK_DENIED is returned for a permanent error.  So
+	 * turn it into an ENOLCK.
+	 */
+	if (resp->status == nlm_lck_denied && (fl_flags & FL_SLEEP))
+		status = -ENOLCK;
+	else
+		status = nlm_stat_to_errno(resp->status);
+out:
+	trace_nlmclnt_lock(&req->a_args.lock,
+			   (const struct sockaddr *)&req->a_host->h_addr,
+			   req->a_host->h_addrlen, req->a_res.status);
+	nlmclnt_release_call(req);
+	return status;
+out_unlock:
+	/* Fatal error: ensure that we remove the lock altogether */
+	trace_nlmclnt_lock(&req->a_args.lock,
+			   (const struct sockaddr *)&req->a_host->h_addr,
+			   req->a_host->h_addrlen, req->a_res.status);
+	dprintk("lockd: lock attempt ended in fatal error.\n"
+		"       Attempting to unlock.\n");
+	fl_type = fl->fl_type;
+	fl->fl_type = F_UNLCK;
+	down_read(&host->h_rwsem);
+	do_vfs_lock(fl);
+	up_read(&host->h_rwsem);
+	fl->fl_type = fl_type;
+	fl->fl_flags = fl_flags;
+	nlmclnt_async_call(cred, req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops);
+	return status;
+}
+
+/*
+ * RECLAIM: Try to reclaim a lock
+ */
+int
+nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl,
+		struct nlm_rqst *req)
+{
+	int		status;
+
+	memset(req, 0, sizeof(*req));
+	locks_init_lock(&req->a_args.lock.fl);
+	locks_init_lock(&req->a_res.lock.fl);
+	req->a_host  = host;
+
+	/* Set up the argument struct */
+	nlmclnt_setlockargs(req, fl);
+	req->a_args.reclaim = 1;
+
+	status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_LOCK);
+	if (status >= 0 && req->a_res.status == nlm_granted)
+		return 0;
+
+	printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
+				"(errno %d, status %d)\n", fl->fl_pid,
+				status, ntohl(req->a_res.status));
+
+	/*
+	 * FIXME: This is a serious failure. We can
+	 *
+	 *  a.	Ignore the problem
+	 *  b.	Send the owning process some signal (Linux doesn't have
+	 *	SIGLOST, though...)
+	 *  c.	Retry the operation
+	 *
+	 * Until someone comes up with a simple implementation
+	 * for b or c, I'll choose option a.
+	 */
+
+	return -ENOLCK;
+}
+
+/*
+ * UNLOCK: remove an existing lock
+ */
+static int
+nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
+{
+	struct nlm_host	*host = req->a_host;
+	struct nlm_res	*resp = &req->a_res;
+	int status;
+	unsigned char fl_flags = fl->fl_flags;
+
+	/*
+	 * Note: the server is supposed to either grant us the unlock
+	 * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either
+	 * case, we want to unlock.
+	 */
+	fl->fl_flags |= FL_EXISTS;
+	down_read(&host->h_rwsem);
+	status = do_vfs_lock(fl);
+	up_read(&host->h_rwsem);
+	fl->fl_flags = fl_flags;
+	if (status == -ENOENT) {
+		status = 0;
+		goto out;
+	}
+
+	refcount_inc(&req->a_count);
+	status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req,
+			NLMPROC_UNLOCK, &nlmclnt_unlock_ops);
+	if (status < 0)
+		goto out;
+
+	if (resp->status == nlm_granted)
+		goto out;
+
+	if (resp->status != nlm_lck_denied_nolocks)
+		printk("lockd: unexpected unlock status: %d\n",
+			ntohl(resp->status));
+	/* What to do now? I'm out of my depth... */
+	status = -ENOLCK;
+out:
+	trace_nlmclnt_unlock(&req->a_args.lock,
+			     (const struct sockaddr *)&req->a_host->h_addr,
+			     req->a_host->h_addrlen, req->a_res.status);
+	nlmclnt_release_call(req);
+	return status;
+}
+
+static void nlmclnt_unlock_prepare(struct rpc_task *task, void *data)
+{
+	struct nlm_rqst	*req = data;
+	const struct nlmclnt_operations *nlmclnt_ops = req->a_host->h_nlmclnt_ops;
+	bool defer_call = false;
+
+	if (nlmclnt_ops && nlmclnt_ops->nlmclnt_unlock_prepare)
+		defer_call = nlmclnt_ops->nlmclnt_unlock_prepare(task, req->a_callback_data);
+
+	if (!defer_call)
+		rpc_call_start(task);
+}
+
+static void nlmclnt_unlock_callback(struct rpc_task *task, void *data)
+{
+	struct nlm_rqst	*req = data;
+	u32 status = ntohl(req->a_res.status);
+
+	if (RPC_SIGNALLED(task))
+		goto die;
+
+	if (task->tk_status < 0) {
+		dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
+		switch (task->tk_status) {
+		case -EACCES:
+		case -EIO:
+			goto die;
+		default:
+			goto retry_rebind;
+		}
+	}
+	if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
+		rpc_delay(task, NLMCLNT_GRACE_WAIT);
+		goto retry_unlock;
+	}
+	if (status != NLM_LCK_GRANTED)
+		printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
+die:
+	return;
+ retry_rebind:
+	nlm_rebind_host(req->a_host);
+ retry_unlock:
+	rpc_restart_call(task);
+}
+
+static const struct rpc_call_ops nlmclnt_unlock_ops = {
+	.rpc_call_prepare = nlmclnt_unlock_prepare,
+	.rpc_call_done = nlmclnt_unlock_callback,
+	.rpc_release = nlmclnt_rpc_release,
+};
+
+/*
+ * Cancel a blocked lock request.
+ * We always use an async RPC call for this in order not to hang a
+ * process that has been Ctrl-C'ed.
+ */
+static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl)
+{
+	struct nlm_rqst	*req;
+	int status;
+
+	dprintk("lockd: blocking lock attempt was interrupted by a signal.\n"
+		"       Attempting to cancel lock.\n");
+
+	req = nlm_alloc_call(host);
+	if (!req)
+		return -ENOMEM;
+	req->a_flags = RPC_TASK_ASYNC;
+
+	nlmclnt_setlockargs(req, fl);
+	req->a_args.block = block;
+
+	refcount_inc(&req->a_count);
+	status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req,
+			NLMPROC_CANCEL, &nlmclnt_cancel_ops);
+	if (status == 0 && req->a_res.status == nlm_lck_denied)
+		status = -ENOLCK;
+	nlmclnt_release_call(req);
+	return status;
+}
+
+static void nlmclnt_cancel_callback(struct rpc_task *task, void *data)
+{
+	struct nlm_rqst	*req = data;
+	u32 status = ntohl(req->a_res.status);
+
+	if (RPC_SIGNALLED(task))
+		goto die;
+
+	if (task->tk_status < 0) {
+		dprintk("lockd: CANCEL call error %d, retrying.\n",
+					task->tk_status);
+		goto retry_cancel;
+	}
+
+	switch (status) {
+	case NLM_LCK_GRANTED:
+	case NLM_LCK_DENIED_GRACE_PERIOD:
+	case NLM_LCK_DENIED:
+		/* Everything's good */
+		break;
+	case NLM_LCK_DENIED_NOLOCKS:
+		dprintk("lockd: CANCEL failed (server has no locks)\n");
+		goto retry_cancel;
+	default:
+		printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
+			status);
+	}
+
+die:
+	return;
+
+retry_cancel:
+	/* Don't ever retry more than 3 times */
+	if (req->a_retries++ >= NLMCLNT_MAX_RETRIES)
+		goto die;
+	nlm_rebind_host(req->a_host);
+	rpc_restart_call(task);
+	rpc_delay(task, 30 * HZ);
+}
+
+static const struct rpc_call_ops nlmclnt_cancel_ops = {
+	.rpc_call_done = nlmclnt_cancel_callback,
+	.rpc_release = nlmclnt_rpc_release,
+};
+
+/*
+ * Convert an NLM status code to a generic kernel errno
+ */
+static int
+nlm_stat_to_errno(__be32 status)
+{
+	switch(ntohl(status)) {
+	case NLM_LCK_GRANTED:
+		return 0;
+	case NLM_LCK_DENIED:
+		return -EAGAIN;
+	case NLM_LCK_DENIED_NOLOCKS:
+	case NLM_LCK_DENIED_GRACE_PERIOD:
+		return -ENOLCK;
+	case NLM_LCK_BLOCKED:
+		printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n");
+		return -ENOLCK;
+#ifdef CONFIG_LOCKD_V4
+	case NLM_DEADLCK:
+		return -EDEADLK;
+	case NLM_ROFS:
+		return -EROFS;
+	case NLM_STALE_FH:
+		return -ESTALE;
+	case NLM_FBIG:
+		return -EOVERFLOW;
+	case NLM_FAILED:
+		return -ENOLCK;
+#endif
+	}
+	printk(KERN_NOTICE "lockd: unexpected server status %d\n",
+		 ntohl(status));
+	return -ENOLCK;
+}
diff --git a/fs/lockd/clntxdr.c b/fs/lockd/clntxdr.c
new file mode 100644
index 0000000000..4df62f6355
--- /dev/null
+++ b/fs/lockd/clntxdr.c
@@ -0,0 +1,612 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/lockd/clntxdr.c
+ *
+ * XDR functions to encode/decode NLM version 3 RPC arguments and results.
+ * NLM version 3 is backwards compatible with NLM versions 1 and 2.
+ *
+ * NLM client-side only.
+ *
+ * Copyright (C) 2010, Oracle.  All rights reserved.
+ */
+
+#include <linux/types.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/stats.h>
+#include <linux/lockd/lockd.h>
+
+#include <uapi/linux/nfs2.h>
+
+#define NLMDBG_FACILITY		NLMDBG_XDR
+
+#if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
+#  error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
+#endif
+
+/*
+ * Declare the space requirements for NLM arguments and replies as
+ * number of 32bit-words
+ */
+#define NLM_cookie_sz		(1+(NLM_MAXCOOKIELEN>>2))
+#define NLM_caller_sz		(1+(NLMCLNT_OHSIZE>>2))
+#define NLM_owner_sz		(1+(NLMCLNT_OHSIZE>>2))
+#define NLM_fhandle_sz		(1+(NFS2_FHSIZE>>2))
+#define NLM_lock_sz		(3+NLM_caller_sz+NLM_owner_sz+NLM_fhandle_sz)
+#define NLM_holder_sz		(4+NLM_owner_sz)
+
+#define NLM_testargs_sz		(NLM_cookie_sz+1+NLM_lock_sz)
+#define NLM_lockargs_sz		(NLM_cookie_sz+4+NLM_lock_sz)
+#define NLM_cancargs_sz		(NLM_cookie_sz+2+NLM_lock_sz)
+#define NLM_unlockargs_sz	(NLM_cookie_sz+NLM_lock_sz)
+
+#define NLM_testres_sz		(NLM_cookie_sz+1+NLM_holder_sz)
+#define NLM_res_sz		(NLM_cookie_sz+1)
+#define NLM_norep_sz		(0)
+
+
+static s32 loff_t_to_s32(loff_t offset)
+{
+	s32 res;
+
+	if (offset >= NLM_OFFSET_MAX)
+		res = NLM_OFFSET_MAX;
+	else if (offset <= -NLM_OFFSET_MAX)
+		res = -NLM_OFFSET_MAX;
+	else
+		res = offset;
+	return res;
+}
+
+static void nlm_compute_offsets(const struct nlm_lock *lock,
+				u32 *l_offset, u32 *l_len)
+{
+	const struct file_lock *fl = &lock->fl;
+
+	*l_offset = loff_t_to_s32(fl->fl_start);
+	if (fl->fl_end == OFFSET_MAX)
+		*l_len = 0;
+	else
+		*l_len = loff_t_to_s32(fl->fl_end - fl->fl_start + 1);
+}
+
+/*
+ * Encode/decode NLMv3 basic data types
+ *
+ * Basic NLMv3 data types are not defined in an IETF standards
+ * document.  X/Open has a description of these data types that
+ * is useful.  See Chapter 10 of "Protocols for Interworking:
+ * XNFS, Version 3W".
+ *
+ * Not all basic data types have their own encoding and decoding
+ * functions.  For run-time efficiency, some data types are encoded
+ * or decoded inline.
+ */
+
+static void encode_bool(struct xdr_stream *xdr, const int value)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = value ? xdr_one : xdr_zero;
+}
+
+static void encode_int32(struct xdr_stream *xdr, const s32 value)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(value);
+}
+
+/*
+ *	typedef opaque netobj<MAXNETOBJ_SZ>
+ */
+static void encode_netobj(struct xdr_stream *xdr,
+			  const u8 *data, const unsigned int length)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4 + length);
+	xdr_encode_opaque(p, data, length);
+}
+
+static int decode_netobj(struct xdr_stream *xdr,
+			 struct xdr_netobj *obj)
+{
+	ssize_t ret;
+
+	ret = xdr_stream_decode_opaque_inline(xdr, (void *)&obj->data,
+			XDR_MAX_NETOBJ);
+	if (unlikely(ret < 0))
+		return -EIO;
+	obj->len = ret;
+	return 0;
+}
+
+/*
+ *	netobj cookie;
+ */
+static void encode_cookie(struct xdr_stream *xdr,
+			  const struct nlm_cookie *cookie)
+{
+	encode_netobj(xdr, (u8 *)&cookie->data, cookie->len);
+}
+
+static int decode_cookie(struct xdr_stream *xdr,
+			 struct nlm_cookie *cookie)
+{
+	u32 length;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	length = be32_to_cpup(p++);
+	/* apparently HPUX can return empty cookies */
+	if (length == 0)
+		goto out_hpux;
+	if (length > NLM_MAXCOOKIELEN)
+		goto out_size;
+	p = xdr_inline_decode(xdr, length);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	cookie->len = length;
+	memcpy(cookie->data, p, length);
+	return 0;
+out_hpux:
+	cookie->len = 4;
+	memset(cookie->data, 0, 4);
+	return 0;
+out_size:
+	dprintk("NFS: returned cookie was too long: %u\n", length);
+	return -EIO;
+out_overflow:
+	return -EIO;
+}
+
+/*
+ *	netobj fh;
+ */
+static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
+{
+	encode_netobj(xdr, (u8 *)&fh->data, NFS2_FHSIZE);
+}
+
+/*
+ *	enum nlm_stats {
+ *		LCK_GRANTED = 0,
+ *		LCK_DENIED = 1,
+ *		LCK_DENIED_NOLOCKS = 2,
+ *		LCK_BLOCKED = 3,
+ *		LCK_DENIED_GRACE_PERIOD = 4
+ *	};
+ *
+ *
+ *	struct nlm_stat {
+ *		nlm_stats stat;
+ *	};
+ *
+ * NB: we don't swap bytes for the NLM status values.  The upper
+ * layers deal directly with the status value in network byte
+ * order.
+ */
+
+static void encode_nlm_stat(struct xdr_stream *xdr,
+			    const __be32 stat)
+{
+	__be32 *p;
+
+	WARN_ON_ONCE(be32_to_cpu(stat) > NLM_LCK_DENIED_GRACE_PERIOD);
+	p = xdr_reserve_space(xdr, 4);
+	*p = stat;
+}
+
+static int decode_nlm_stat(struct xdr_stream *xdr,
+			   __be32 *stat)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	if (unlikely(ntohl(*p) > ntohl(nlm_lck_denied_grace_period)))
+		goto out_enum;
+	*stat = *p;
+	return 0;
+out_enum:
+	dprintk("%s: server returned invalid nlm_stats value: %u\n",
+		__func__, be32_to_cpup(p));
+	return -EIO;
+out_overflow:
+	return -EIO;
+}
+
+/*
+ *	struct nlm_holder {
+ *		bool exclusive;
+ *		int uppid;
+ *		netobj oh;
+ *		unsigned l_offset;
+ *		unsigned l_len;
+ *	};
+ */
+static void encode_nlm_holder(struct xdr_stream *xdr,
+			      const struct nlm_res *result)
+{
+	const struct nlm_lock *lock = &result->lock;
+	u32 l_offset, l_len;
+	__be32 *p;
+
+	encode_bool(xdr, lock->fl.fl_type == F_RDLCK);
+	encode_int32(xdr, lock->svid);
+	encode_netobj(xdr, lock->oh.data, lock->oh.len);
+
+	p = xdr_reserve_space(xdr, 4 + 4);
+	nlm_compute_offsets(lock, &l_offset, &l_len);
+	*p++ = cpu_to_be32(l_offset);
+	*p   = cpu_to_be32(l_len);
+}
+
+static int decode_nlm_holder(struct xdr_stream *xdr, struct nlm_res *result)
+{
+	struct nlm_lock *lock = &result->lock;
+	struct file_lock *fl = &lock->fl;
+	u32 exclusive, l_offset, l_len;
+	int error;
+	__be32 *p;
+	s32 end;
+
+	memset(lock, 0, sizeof(*lock));
+	locks_init_lock(fl);
+
+	p = xdr_inline_decode(xdr, 4 + 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	exclusive = be32_to_cpup(p++);
+	lock->svid = be32_to_cpup(p);
+	fl->fl_pid = (pid_t)lock->svid;
+
+	error = decode_netobj(xdr, &lock->oh);
+	if (unlikely(error))
+		goto out;
+
+	p = xdr_inline_decode(xdr, 4 + 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+
+	fl->fl_flags = FL_POSIX;
+	fl->fl_type  = exclusive != 0 ? F_WRLCK : F_RDLCK;
+	l_offset = be32_to_cpup(p++);
+	l_len = be32_to_cpup(p);
+	end = l_offset + l_len - 1;
+
+	fl->fl_start = (loff_t)l_offset;
+	if (l_len == 0 || end < 0)
+		fl->fl_end = OFFSET_MAX;
+	else
+		fl->fl_end = (loff_t)end;
+	error = 0;
+out:
+	return error;
+out_overflow:
+	return -EIO;
+}
+
+/*
+ *	string caller_name<LM_MAXSTRLEN>;
+ */
+static void encode_caller_name(struct xdr_stream *xdr, const char *name)
+{
+	/* NB: client-side does not set lock->len */
+	u32 length = strlen(name);
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4 + length);
+	xdr_encode_opaque(p, name, length);
+}
+
+/*
+ *	struct nlm_lock {
+ *		string caller_name<LM_MAXSTRLEN>;
+ *		netobj fh;
+ *		netobj oh;
+ *		int uppid;
+ *		unsigned l_offset;
+ *		unsigned l_len;
+ *	};
+ */
+static void encode_nlm_lock(struct xdr_stream *xdr,
+			    const struct nlm_lock *lock)
+{
+	u32 l_offset, l_len;
+	__be32 *p;
+
+	encode_caller_name(xdr, lock->caller);
+	encode_fh(xdr, &lock->fh);
+	encode_netobj(xdr, lock->oh.data, lock->oh.len);
+
+	p = xdr_reserve_space(xdr, 4 + 4 + 4);
+	*p++ = cpu_to_be32(lock->svid);
+
+	nlm_compute_offsets(lock, &l_offset, &l_len);
+	*p++ = cpu_to_be32(l_offset);
+	*p   = cpu_to_be32(l_len);
+}
+
+
+/*
+ * NLMv3 XDR encode functions
+ *
+ * NLMv3 argument types are defined in Chapter 10 of The Open Group's
+ * "Protocols for Interworking: XNFS, Version 3W".
+ */
+
+/*
+ *	struct nlm_testargs {
+ *		netobj cookie;
+ *		bool exclusive;
+ *		struct nlm_lock alock;
+ *	};
+ */
+static void nlm_xdr_enc_testargs(struct rpc_rqst *req,
+				 struct xdr_stream *xdr,
+				 const void *data)
+{
+	const struct nlm_args *args = data;
+	const struct nlm_lock *lock = &args->lock;
+
+	encode_cookie(xdr, &args->cookie);
+	encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
+	encode_nlm_lock(xdr, lock);
+}
+
+/*
+ *	struct nlm_lockargs {
+ *		netobj cookie;
+ *		bool block;
+ *		bool exclusive;
+ *		struct nlm_lock alock;
+ *		bool reclaim;
+ *		int state;
+ *	};
+ */
+static void nlm_xdr_enc_lockargs(struct rpc_rqst *req,
+				 struct xdr_stream *xdr,
+				 const void *data)
+{
+	const struct nlm_args *args = data;
+	const struct nlm_lock *lock = &args->lock;
+
+	encode_cookie(xdr, &args->cookie);
+	encode_bool(xdr, args->block);
+	encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
+	encode_nlm_lock(xdr, lock);
+	encode_bool(xdr, args->reclaim);
+	encode_int32(xdr, args->state);
+}
+
+/*
+ *	struct nlm_cancargs {
+ *		netobj cookie;
+ *		bool block;
+ *		bool exclusive;
+ *		struct nlm_lock alock;
+ *	};
+ */
+static void nlm_xdr_enc_cancargs(struct rpc_rqst *req,
+				 struct xdr_stream *xdr,
+				 const void *data)
+{
+	const struct nlm_args *args = data;
+	const struct nlm_lock *lock = &args->lock;
+
+	encode_cookie(xdr, &args->cookie);
+	encode_bool(xdr, args->block);
+	encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
+	encode_nlm_lock(xdr, lock);
+}
+
+/*
+ *	struct nlm_unlockargs {
+ *		netobj cookie;
+ *		struct nlm_lock alock;
+ *	};
+ */
+static void nlm_xdr_enc_unlockargs(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct nlm_args *args = data;
+	const struct nlm_lock *lock = &args->lock;
+
+	encode_cookie(xdr, &args->cookie);
+	encode_nlm_lock(xdr, lock);
+}
+
+/*
+ *	struct nlm_res {
+ *		netobj cookie;
+ *		nlm_stat stat;
+ *	};
+ */
+static void nlm_xdr_enc_res(struct rpc_rqst *req,
+			    struct xdr_stream *xdr,
+			    const void *data)
+{
+	const struct nlm_res *result = data;
+
+	encode_cookie(xdr, &result->cookie);
+	encode_nlm_stat(xdr, result->status);
+}
+
+/*
+ *	union nlm_testrply switch (nlm_stats stat) {
+ *	case LCK_DENIED:
+ *		struct nlm_holder holder;
+ *	default:
+ *		void;
+ *	};
+ *
+ *	struct nlm_testres {
+ *		netobj cookie;
+ *		nlm_testrply test_stat;
+ *	};
+ */
+static void encode_nlm_testrply(struct xdr_stream *xdr,
+				const struct nlm_res *result)
+{
+	if (result->status == nlm_lck_denied)
+		encode_nlm_holder(xdr, result);
+}
+
+static void nlm_xdr_enc_testres(struct rpc_rqst *req,
+				struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct nlm_res *result = data;
+
+	encode_cookie(xdr, &result->cookie);
+	encode_nlm_stat(xdr, result->status);
+	encode_nlm_testrply(xdr, result);
+}
+
+
+/*
+ * NLMv3 XDR decode functions
+ *
+ * NLMv3 result types are defined in Chapter 10 of The Open Group's
+ * "Protocols for Interworking: XNFS, Version 3W".
+ */
+
+/*
+ *	union nlm_testrply switch (nlm_stats stat) {
+ *	case LCK_DENIED:
+ *		struct nlm_holder holder;
+ *	default:
+ *		void;
+ *	};
+ *
+ *	struct nlm_testres {
+ *		netobj cookie;
+ *		nlm_testrply test_stat;
+ *	};
+ */
+static int decode_nlm_testrply(struct xdr_stream *xdr,
+			       struct nlm_res *result)
+{
+	int error;
+
+	error = decode_nlm_stat(xdr, &result->status);
+	if (unlikely(error))
+		goto out;
+	if (result->status == nlm_lck_denied)
+		error = decode_nlm_holder(xdr, result);
+out:
+	return error;
+}
+
+static int nlm_xdr_dec_testres(struct rpc_rqst *req,
+			       struct xdr_stream *xdr,
+			       void *data)
+{
+	struct nlm_res *result = data;
+	int error;
+
+	error = decode_cookie(xdr, &result->cookie);
+	if (unlikely(error))
+		goto out;
+	error = decode_nlm_testrply(xdr, result);
+out:
+	return error;
+}
+
+/*
+ *	struct nlm_res {
+ *		netobj cookie;
+ *		nlm_stat stat;
+ *	};
+ */
+static int nlm_xdr_dec_res(struct rpc_rqst *req,
+			   struct xdr_stream *xdr,
+			   void *data)
+{
+	struct nlm_res *result = data;
+	int error;
+
+	error = decode_cookie(xdr, &result->cookie);
+	if (unlikely(error))
+		goto out;
+	error = decode_nlm_stat(xdr, &result->status);
+out:
+	return error;
+}
+
+
+/*
+ * For NLM, a void procedure really returns nothing
+ */
+#define nlm_xdr_dec_norep	NULL
+
+#define PROC(proc, argtype, restype)	\
+[NLMPROC_##proc] = {							\
+	.p_proc      = NLMPROC_##proc,					\
+	.p_encode    = nlm_xdr_enc_##argtype,		\
+	.p_decode    = nlm_xdr_dec_##restype,				\
+	.p_arglen    = NLM_##argtype##_sz,				\
+	.p_replen    = NLM_##restype##_sz,				\
+	.p_statidx   = NLMPROC_##proc,					\
+	.p_name      = #proc,						\
+	}
+
+static const struct rpc_procinfo nlm_procedures[] = {
+	PROC(TEST,		testargs,	testres),
+	PROC(LOCK,		lockargs,	res),
+	PROC(CANCEL,		cancargs,	res),
+	PROC(UNLOCK,		unlockargs,	res),
+	PROC(GRANTED,		testargs,	res),
+	PROC(TEST_MSG,		testargs,	norep),
+	PROC(LOCK_MSG,		lockargs,	norep),
+	PROC(CANCEL_MSG,	cancargs,	norep),
+	PROC(UNLOCK_MSG,	unlockargs,	norep),
+	PROC(GRANTED_MSG,	testargs,	norep),
+	PROC(TEST_RES,		testres,	norep),
+	PROC(LOCK_RES,		res,		norep),
+	PROC(CANCEL_RES,	res,		norep),
+	PROC(UNLOCK_RES,	res,		norep),
+	PROC(GRANTED_RES,	res,		norep),
+};
+
+static unsigned int nlm_version1_counts[ARRAY_SIZE(nlm_procedures)];
+static const struct rpc_version	nlm_version1 = {
+	.number		= 1,
+	.nrprocs	= ARRAY_SIZE(nlm_procedures),
+	.procs		= nlm_procedures,
+	.counts		= nlm_version1_counts,
+};
+
+static unsigned int nlm_version3_counts[ARRAY_SIZE(nlm_procedures)];
+static const struct rpc_version	nlm_version3 = {
+	.number		= 3,
+	.nrprocs	= ARRAY_SIZE(nlm_procedures),
+	.procs		= nlm_procedures,
+	.counts		= nlm_version3_counts,
+};
+
+static const struct rpc_version	*nlm_versions[] = {
+	[1] = &nlm_version1,
+	[3] = &nlm_version3,
+#ifdef CONFIG_LOCKD_V4
+	[4] = &nlm_version4,
+#endif
+};
+
+static struct rpc_stat		nlm_rpc_stats;
+
+const struct rpc_program	nlm_program = {
+	.name		= "lockd",
+	.number		= NLM_PROGRAM,
+	.nrvers		= ARRAY_SIZE(nlm_versions),
+	.version	= nlm_versions,
+	.stats		= &nlm_rpc_stats,
+};
diff --git a/fs/lockd/host.c b/fs/lockd/host.c
new file mode 100644
index 0000000000..127a728fcb
--- /dev/null
+++ b/fs/lockd/host.c
@@ -0,0 +1,695 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/lockd/host.c
+ *
+ * Management for NLM peer hosts. The nlm_host struct is shared
+ * between client and server implementation. The only reason to
+ * do so is to reduce code bloat.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/lockd/lockd.h>
+#include <linux/mutex.h>
+
+#include <linux/sunrpc/svc_xprt.h>
+
+#include <net/ipv6.h>
+
+#include "netns.h"
+
+#define NLMDBG_FACILITY		NLMDBG_HOSTCACHE
+#define NLM_HOST_NRHASH		32
+#define NLM_HOST_REBIND		(60 * HZ)
+#define NLM_HOST_EXPIRE		(300 * HZ)
+#define NLM_HOST_COLLECT	(120 * HZ)
+
+static struct hlist_head	nlm_server_hosts[NLM_HOST_NRHASH];
+static struct hlist_head	nlm_client_hosts[NLM_HOST_NRHASH];
+
+#define for_each_host(host, chain, table) \
+	for ((chain) = (table); \
+	     (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
+		hlist_for_each_entry((host), (chain), h_hash)
+
+#define for_each_host_safe(host, next, chain, table) \
+	for ((chain) = (table); \
+	     (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
+		hlist_for_each_entry_safe((host), (next), \
+						(chain), h_hash)
+
+static unsigned long		nrhosts;
+static DEFINE_MUTEX(nlm_host_mutex);
+
+static void			nlm_gc_hosts(struct net *net);
+
+struct nlm_lookup_host_info {
+	const int		server;		/* search for server|client */
+	const struct sockaddr	*sap;		/* address to search for */
+	const size_t		salen;		/* it's length */
+	const unsigned short	protocol;	/* transport to search for*/
+	const u32		version;	/* NLM version to search for */
+	const char		*hostname;	/* remote's hostname */
+	const size_t		hostname_len;	/* it's length */
+	const int		noresvport;	/* use non-priv port */
+	struct net		*net;		/* network namespace to bind */
+	const struct cred	*cred;
+};
+
+/*
+ * Hash function must work well on big- and little-endian platforms
+ */
+static unsigned int __nlm_hash32(const __be32 n)
+{
+	unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
+	return hash ^ (hash >> 8);
+}
+
+static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
+{
+	const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
+	return __nlm_hash32(sin->sin_addr.s_addr);
+}
+
+static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
+{
+	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
+	const struct in6_addr addr = sin6->sin6_addr;
+	return __nlm_hash32(addr.s6_addr32[0]) ^
+	       __nlm_hash32(addr.s6_addr32[1]) ^
+	       __nlm_hash32(addr.s6_addr32[2]) ^
+	       __nlm_hash32(addr.s6_addr32[3]);
+}
+
+static unsigned int nlm_hash_address(const struct sockaddr *sap)
+{
+	unsigned int hash;
+
+	switch (sap->sa_family) {
+	case AF_INET:
+		hash = __nlm_hash_addr4(sap);
+		break;
+	case AF_INET6:
+		hash = __nlm_hash_addr6(sap);
+		break;
+	default:
+		hash = 0;
+	}
+	return hash & (NLM_HOST_NRHASH - 1);
+}
+
+/*
+ * Allocate and initialize an nlm_host.  Common to both client and server.
+ */
+static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
+				       struct nsm_handle *nsm)
+{
+	struct nlm_host *host = NULL;
+	unsigned long now = jiffies;
+
+	if (nsm != NULL)
+		refcount_inc(&nsm->sm_count);
+	else {
+		host = NULL;
+		nsm = nsm_get_handle(ni->net, ni->sap, ni->salen,
+					ni->hostname, ni->hostname_len);
+		if (unlikely(nsm == NULL)) {
+			dprintk("lockd: %s failed; no nsm handle\n",
+				__func__);
+			goto out;
+		}
+	}
+
+	host = kmalloc(sizeof(*host), GFP_KERNEL);
+	if (unlikely(host == NULL)) {
+		dprintk("lockd: %s failed; no memory\n", __func__);
+		nsm_release(nsm);
+		goto out;
+	}
+
+	memcpy(nlm_addr(host), ni->sap, ni->salen);
+	host->h_addrlen    = ni->salen;
+	rpc_set_port(nlm_addr(host), 0);
+	host->h_srcaddrlen = 0;
+
+	host->h_rpcclnt    = NULL;
+	host->h_name	   = nsm->sm_name;
+	host->h_version    = ni->version;
+	host->h_proto      = ni->protocol;
+	host->h_reclaiming = 0;
+	host->h_server     = ni->server;
+	host->h_noresvport = ni->noresvport;
+	host->h_inuse      = 0;
+	init_waitqueue_head(&host->h_gracewait);
+	init_rwsem(&host->h_rwsem);
+	host->h_state      = 0;
+	host->h_nsmstate   = 0;
+	host->h_pidcount   = 0;
+	refcount_set(&host->h_count, 1);
+	mutex_init(&host->h_mutex);
+	host->h_nextrebind = now + NLM_HOST_REBIND;
+	host->h_expires    = now + NLM_HOST_EXPIRE;
+	INIT_LIST_HEAD(&host->h_lockowners);
+	spin_lock_init(&host->h_lock);
+	INIT_LIST_HEAD(&host->h_granted);
+	INIT_LIST_HEAD(&host->h_reclaim);
+	host->h_nsmhandle  = nsm;
+	host->h_addrbuf    = nsm->sm_addrbuf;
+	host->net	   = ni->net;
+	host->h_cred	   = get_cred(ni->cred);
+	strscpy(host->nodename, utsname()->nodename, sizeof(host->nodename));
+
+out:
+	return host;
+}
+
+/*
+ * Destroy an nlm_host and free associated resources
+ *
+ * Caller must hold nlm_host_mutex.
+ */
+static void nlm_destroy_host_locked(struct nlm_host *host)
+{
+	struct rpc_clnt	*clnt;
+	struct lockd_net *ln = net_generic(host->net, lockd_net_id);
+
+	dprintk("lockd: destroy host %s\n", host->h_name);
+
+	hlist_del_init(&host->h_hash);
+
+	nsm_unmonitor(host);
+	nsm_release(host->h_nsmhandle);
+
+	clnt = host->h_rpcclnt;
+	if (clnt != NULL)
+		rpc_shutdown_client(clnt);
+	put_cred(host->h_cred);
+	kfree(host);
+
+	ln->nrhosts--;
+	nrhosts--;
+}
+
+/**
+ * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
+ * @sap: network address of server
+ * @salen: length of server address
+ * @protocol: transport protocol to use
+ * @version: NLM protocol version
+ * @hostname: '\0'-terminated hostname of server
+ * @noresvport: 1 if non-privileged port should be used
+ * @net: pointer to net namespace
+ * @cred: pointer to cred
+ *
+ * Returns an nlm_host structure that matches the passed-in
+ * [server address, transport protocol, NLM version, server hostname].
+ * If one doesn't already exist in the host cache, a new handle is
+ * created and returned.
+ */
+struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
+				     const size_t salen,
+				     const unsigned short protocol,
+				     const u32 version,
+				     const char *hostname,
+				     int noresvport,
+				     struct net *net,
+				     const struct cred *cred)
+{
+	struct nlm_lookup_host_info ni = {
+		.server		= 0,
+		.sap		= sap,
+		.salen		= salen,
+		.protocol	= protocol,
+		.version	= version,
+		.hostname	= hostname,
+		.hostname_len	= strlen(hostname),
+		.noresvport	= noresvport,
+		.net		= net,
+		.cred		= cred,
+	};
+	struct hlist_head *chain;
+	struct nlm_host	*host;
+	struct nsm_handle *nsm = NULL;
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+	dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
+			(hostname ? hostname : "<none>"), version,
+			(protocol == IPPROTO_UDP ? "udp" : "tcp"));
+
+	mutex_lock(&nlm_host_mutex);
+
+	chain = &nlm_client_hosts[nlm_hash_address(sap)];
+	hlist_for_each_entry(host, chain, h_hash) {
+		if (host->net != net)
+			continue;
+		if (!rpc_cmp_addr(nlm_addr(host), sap))
+			continue;
+
+		/* Same address. Share an NSM handle if we already have one */
+		if (nsm == NULL)
+			nsm = host->h_nsmhandle;
+
+		if (host->h_proto != protocol)
+			continue;
+		if (host->h_version != version)
+			continue;
+
+		nlm_get_host(host);
+		dprintk("lockd: %s found host %s (%s)\n", __func__,
+			host->h_name, host->h_addrbuf);
+		goto out;
+	}
+
+	host = nlm_alloc_host(&ni, nsm);
+	if (unlikely(host == NULL))
+		goto out;
+
+	hlist_add_head(&host->h_hash, chain);
+	ln->nrhosts++;
+	nrhosts++;
+
+	dprintk("lockd: %s created host %s (%s)\n", __func__,
+		host->h_name, host->h_addrbuf);
+
+out:
+	mutex_unlock(&nlm_host_mutex);
+	return host;
+}
+
+/**
+ * nlmclnt_release_host - release client nlm_host
+ * @host: nlm_host to release
+ *
+ */
+void nlmclnt_release_host(struct nlm_host *host)
+{
+	if (host == NULL)
+		return;
+
+	dprintk("lockd: release client host %s\n", host->h_name);
+
+	WARN_ON_ONCE(host->h_server);
+
+	if (refcount_dec_and_mutex_lock(&host->h_count, &nlm_host_mutex)) {
+		WARN_ON_ONCE(!list_empty(&host->h_lockowners));
+		WARN_ON_ONCE(!list_empty(&host->h_granted));
+		WARN_ON_ONCE(!list_empty(&host->h_reclaim));
+
+		nlm_destroy_host_locked(host);
+		mutex_unlock(&nlm_host_mutex);
+	}
+}
+
+/**
+ * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
+ * @rqstp: incoming NLM request
+ * @hostname: name of client host
+ * @hostname_len: length of client hostname
+ *
+ * Returns an nlm_host structure that matches the [client address,
+ * transport protocol, NLM version, client hostname] of the passed-in
+ * NLM request.  If one doesn't already exist in the host cache, a
+ * new handle is created and returned.
+ *
+ * Before possibly creating a new nlm_host, construct a sockaddr
+ * for a specific source address in case the local system has
+ * multiple network addresses.  The family of the address in
+ * rq_daddr is guaranteed to be the same as the family of the
+ * address in rq_addr, so it's safe to use the same family for
+ * the source address.
+ */
+struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
+				    const char *hostname,
+				    const size_t hostname_len)
+{
+	struct hlist_head *chain;
+	struct nlm_host	*host = NULL;
+	struct nsm_handle *nsm = NULL;
+	struct sockaddr *src_sap = svc_daddr(rqstp);
+	size_t src_len = rqstp->rq_daddrlen;
+	struct net *net = SVC_NET(rqstp);
+	struct nlm_lookup_host_info ni = {
+		.server		= 1,
+		.sap		= svc_addr(rqstp),
+		.salen		= rqstp->rq_addrlen,
+		.protocol	= rqstp->rq_prot,
+		.version	= rqstp->rq_vers,
+		.hostname	= hostname,
+		.hostname_len	= hostname_len,
+		.net		= net,
+	};
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+	dprintk("lockd: %s(host='%.*s', vers=%u, proto=%s)\n", __func__,
+			(int)hostname_len, hostname, rqstp->rq_vers,
+			(rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
+
+	mutex_lock(&nlm_host_mutex);
+
+	if (time_after_eq(jiffies, ln->next_gc))
+		nlm_gc_hosts(net);
+
+	chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
+	hlist_for_each_entry(host, chain, h_hash) {
+		if (host->net != net)
+			continue;
+		if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
+			continue;
+
+		/* Same address. Share an NSM handle if we already have one */
+		if (nsm == NULL)
+			nsm = host->h_nsmhandle;
+
+		if (host->h_proto != ni.protocol)
+			continue;
+		if (host->h_version != ni.version)
+			continue;
+		if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap))
+			continue;
+
+		/* Move to head of hash chain. */
+		hlist_del(&host->h_hash);
+		hlist_add_head(&host->h_hash, chain);
+
+		nlm_get_host(host);
+		dprintk("lockd: %s found host %s (%s)\n",
+			__func__, host->h_name, host->h_addrbuf);
+		goto out;
+	}
+
+	host = nlm_alloc_host(&ni, nsm);
+	if (unlikely(host == NULL))
+		goto out;
+
+	memcpy(nlm_srcaddr(host), src_sap, src_len);
+	host->h_srcaddrlen = src_len;
+	hlist_add_head(&host->h_hash, chain);
+	ln->nrhosts++;
+	nrhosts++;
+
+	refcount_inc(&host->h_count);
+
+	dprintk("lockd: %s created host %s (%s)\n",
+		__func__, host->h_name, host->h_addrbuf);
+
+out:
+	mutex_unlock(&nlm_host_mutex);
+	return host;
+}
+
+/**
+ * nlmsvc_release_host - release server nlm_host
+ * @host: nlm_host to release
+ *
+ * Host is destroyed later in nlm_gc_host().
+ */
+void nlmsvc_release_host(struct nlm_host *host)
+{
+	if (host == NULL)
+		return;
+
+	dprintk("lockd: release server host %s\n", host->h_name);
+
+	WARN_ON_ONCE(!host->h_server);
+	refcount_dec(&host->h_count);
+}
+
+/*
+ * Create the NLM RPC client for an NLM peer
+ */
+struct rpc_clnt *
+nlm_bind_host(struct nlm_host *host)
+{
+	struct rpc_clnt	*clnt;
+
+	dprintk("lockd: nlm_bind_host %s (%s)\n",
+			host->h_name, host->h_addrbuf);
+
+	/* Lock host handle */
+	mutex_lock(&host->h_mutex);
+
+	/* If we've already created an RPC client, check whether
+	 * RPC rebind is required
+	 */
+	if ((clnt = host->h_rpcclnt) != NULL) {
+		nlm_rebind_host(host);
+	} else {
+		unsigned long increment = nlmsvc_timeout;
+		struct rpc_timeout timeparms = {
+			.to_initval	= increment,
+			.to_increment	= increment,
+			.to_maxval	= increment * 6UL,
+			.to_retries	= 5U,
+		};
+		struct rpc_create_args args = {
+			.net		= host->net,
+			.protocol	= host->h_proto,
+			.address	= nlm_addr(host),
+			.addrsize	= host->h_addrlen,
+			.timeout	= &timeparms,
+			.servername	= host->h_name,
+			.program	= &nlm_program,
+			.version	= host->h_version,
+			.authflavor	= RPC_AUTH_UNIX,
+			.flags		= (RPC_CLNT_CREATE_NOPING |
+					   RPC_CLNT_CREATE_AUTOBIND |
+					   RPC_CLNT_CREATE_REUSEPORT),
+			.cred		= host->h_cred,
+		};
+
+		/*
+		 * lockd retries server side blocks automatically so we want
+		 * those to be soft RPC calls. Client side calls need to be
+		 * hard RPC tasks.
+		 */
+		if (!host->h_server)
+			args.flags |= RPC_CLNT_CREATE_HARDRTRY;
+		if (host->h_noresvport)
+			args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
+		if (host->h_srcaddrlen)
+			args.saddress = nlm_srcaddr(host);
+
+		clnt = rpc_create(&args);
+		if (!IS_ERR(clnt))
+			host->h_rpcclnt = clnt;
+		else {
+			printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
+			clnt = NULL;
+		}
+	}
+
+	mutex_unlock(&host->h_mutex);
+	return clnt;
+}
+
+/**
+ * nlm_rebind_host - If needed, force a portmap lookup of the peer's lockd port
+ * @host: NLM host handle for peer
+ *
+ * This is not needed when using a connection-oriented protocol, such as TCP.
+ * The existing autobind mechanism is sufficient to force a rebind when
+ * required, e.g. on connection state transitions.
+ */
+void
+nlm_rebind_host(struct nlm_host *host)
+{
+	if (host->h_proto != IPPROTO_UDP)
+		return;
+
+	if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
+		rpc_force_rebind(host->h_rpcclnt);
+		host->h_nextrebind = jiffies + NLM_HOST_REBIND;
+	}
+}
+
+/*
+ * Increment NLM host count
+ */
+struct nlm_host * nlm_get_host(struct nlm_host *host)
+{
+	if (host) {
+		dprintk("lockd: get host %s\n", host->h_name);
+		refcount_inc(&host->h_count);
+		host->h_expires = jiffies + NLM_HOST_EXPIRE;
+	}
+	return host;
+}
+
+static struct nlm_host *next_host_state(struct hlist_head *cache,
+					struct nsm_handle *nsm,
+					const struct nlm_reboot *info)
+{
+	struct nlm_host *host;
+	struct hlist_head *chain;
+
+	mutex_lock(&nlm_host_mutex);
+	for_each_host(host, chain, cache) {
+		if (host->h_nsmhandle == nsm
+		    && host->h_nsmstate != info->state) {
+			host->h_nsmstate = info->state;
+			host->h_state++;
+
+			nlm_get_host(host);
+			mutex_unlock(&nlm_host_mutex);
+			return host;
+		}
+	}
+
+	mutex_unlock(&nlm_host_mutex);
+	return NULL;
+}
+
+/**
+ * nlm_host_rebooted - Release all resources held by rebooted host
+ * @net:  network namespace
+ * @info: pointer to decoded results of NLM_SM_NOTIFY call
+ *
+ * We were notified that the specified host has rebooted.  Release
+ * all resources held by that peer.
+ */
+void nlm_host_rebooted(const struct net *net, const struct nlm_reboot *info)
+{
+	struct nsm_handle *nsm;
+	struct nlm_host	*host;
+
+	nsm = nsm_reboot_lookup(net, info);
+	if (unlikely(nsm == NULL))
+		return;
+
+	/* Mark all hosts tied to this NSM state as having rebooted.
+	 * We run the loop repeatedly, because we drop the host table
+	 * lock for this.
+	 * To avoid processing a host several times, we match the nsmstate.
+	 */
+	while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) {
+		nlmsvc_free_host_resources(host);
+		nlmsvc_release_host(host);
+	}
+	while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
+		nlmclnt_recovery(host);
+		nlmclnt_release_host(host);
+	}
+
+	nsm_release(nsm);
+}
+
+static void nlm_complain_hosts(struct net *net)
+{
+	struct hlist_head *chain;
+	struct nlm_host	*host;
+
+	if (net) {
+		struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+		if (ln->nrhosts == 0)
+			return;
+		pr_warn("lockd: couldn't shutdown host module for net %x!\n",
+			net->ns.inum);
+		dprintk("lockd: %lu hosts left in net %x:\n", ln->nrhosts,
+			net->ns.inum);
+	} else {
+		if (nrhosts == 0)
+			return;
+		printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
+		dprintk("lockd: %lu hosts left:\n", nrhosts);
+	}
+
+	for_each_host(host, chain, nlm_server_hosts) {
+		if (net && host->net != net)
+			continue;
+		dprintk("       %s (cnt %d use %d exp %ld net %x)\n",
+			host->h_name, refcount_read(&host->h_count),
+			host->h_inuse, host->h_expires, host->net->ns.inum);
+	}
+}
+
+void
+nlm_shutdown_hosts_net(struct net *net)
+{
+	struct hlist_head *chain;
+	struct nlm_host	*host;
+
+	mutex_lock(&nlm_host_mutex);
+
+	/* First, make all hosts eligible for gc */
+	dprintk("lockd: nuking all hosts in net %x...\n",
+		net ? net->ns.inum : 0);
+	for_each_host(host, chain, nlm_server_hosts) {
+		if (net && host->net != net)
+			continue;
+		host->h_expires = jiffies - 1;
+		if (host->h_rpcclnt) {
+			rpc_shutdown_client(host->h_rpcclnt);
+			host->h_rpcclnt = NULL;
+		}
+		nlmsvc_free_host_resources(host);
+	}
+
+	/* Then, perform a garbage collection pass */
+	nlm_gc_hosts(net);
+	nlm_complain_hosts(net);
+	mutex_unlock(&nlm_host_mutex);
+}
+
+/*
+ * Shut down the hosts module.
+ * Note that this routine is called only at server shutdown time.
+ */
+void
+nlm_shutdown_hosts(void)
+{
+	dprintk("lockd: shutting down host module\n");
+	nlm_shutdown_hosts_net(NULL);
+}
+
+/*
+ * Garbage collect any unused NLM hosts.
+ * This GC combines reference counting for async operations with
+ * mark & sweep for resources held by remote clients.
+ */
+static void
+nlm_gc_hosts(struct net *net)
+{
+	struct hlist_head *chain;
+	struct hlist_node *next;
+	struct nlm_host	*host;
+
+	dprintk("lockd: host garbage collection for net %x\n",
+		net ? net->ns.inum : 0);
+	for_each_host(host, chain, nlm_server_hosts) {
+		if (net && host->net != net)
+			continue;
+		host->h_inuse = 0;
+	}
+
+	/* Mark all hosts that hold locks, blocks or shares */
+	nlmsvc_mark_resources(net);
+
+	for_each_host_safe(host, next, chain, nlm_server_hosts) {
+		if (net && host->net != net)
+			continue;
+		if (host->h_inuse || time_before(jiffies, host->h_expires)) {
+			dprintk("nlm_gc_hosts skipping %s "
+				"(cnt %d use %d exp %ld net %x)\n",
+				host->h_name, refcount_read(&host->h_count),
+				host->h_inuse, host->h_expires,
+				host->net->ns.inum);
+			continue;
+		}
+		if (refcount_dec_if_one(&host->h_count))
+			nlm_destroy_host_locked(host);
+	}
+
+	if (net) {
+		struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+		ln->next_gc = jiffies + NLM_HOST_COLLECT;
+	}
+}
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
new file mode 100644
index 0000000000..87a0f207df
--- /dev/null
+++ b/fs/lockd/mon.c
@@ -0,0 +1,581 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/lockd/mon.c
+ *
+ * The kernel statd client.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/slab.h>
+
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/sunrpc/xprtsock.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/lockd/lockd.h>
+
+#include <asm/unaligned.h>
+
+#include "netns.h"
+
+#define NLMDBG_FACILITY		NLMDBG_MONITOR
+#define NSM_PROGRAM		100024
+#define NSM_VERSION		1
+
+enum {
+	NSMPROC_NULL,
+	NSMPROC_STAT,
+	NSMPROC_MON,
+	NSMPROC_UNMON,
+	NSMPROC_UNMON_ALL,
+	NSMPROC_SIMU_CRASH,
+	NSMPROC_NOTIFY,
+};
+
+struct nsm_args {
+	struct nsm_private	*priv;
+	u32			prog;		/* RPC callback info */
+	u32			vers;
+	u32			proc;
+
+	char			*mon_name;
+	const char		*nodename;
+};
+
+struct nsm_res {
+	u32			status;
+	u32			state;
+};
+
+static const struct rpc_program	nsm_program;
+static				DEFINE_SPINLOCK(nsm_lock);
+
+/*
+ * Local NSM state
+ */
+u32	__read_mostly		nsm_local_state;
+bool	__read_mostly		nsm_use_hostnames;
+
+static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
+{
+	return (struct sockaddr *)&nsm->sm_addr;
+}
+
+static struct rpc_clnt *nsm_create(struct net *net, const char *nodename)
+{
+	struct sockaddr_in sin = {
+		.sin_family		= AF_INET,
+		.sin_addr.s_addr	= htonl(INADDR_LOOPBACK),
+	};
+	struct rpc_create_args args = {
+		.net			= net,
+		.protocol		= XPRT_TRANSPORT_TCP,
+		.address		= (struct sockaddr *)&sin,
+		.addrsize		= sizeof(sin),
+		.servername		= "rpc.statd",
+		.nodename		= nodename,
+		.program		= &nsm_program,
+		.version		= NSM_VERSION,
+		.authflavor		= RPC_AUTH_NULL,
+		.flags			= RPC_CLNT_CREATE_NOPING,
+		.cred			= current_cred(),
+	};
+
+	return rpc_create(&args);
+}
+
+static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res,
+			 const struct nlm_host *host)
+{
+	int		status;
+	struct rpc_clnt *clnt;
+	struct nsm_args args = {
+		.priv		= &nsm->sm_priv,
+		.prog		= NLM_PROGRAM,
+		.vers		= 3,
+		.proc		= NLMPROC_NSM_NOTIFY,
+		.mon_name	= nsm->sm_mon_name,
+		.nodename	= host->nodename,
+	};
+	struct rpc_message msg = {
+		.rpc_argp	= &args,
+		.rpc_resp	= res,
+	};
+
+	memset(res, 0, sizeof(*res));
+
+	clnt = nsm_create(host->net, host->nodename);
+	if (IS_ERR(clnt)) {
+		dprintk("lockd: failed to create NSM upcall transport, "
+			"status=%ld, net=%x\n", PTR_ERR(clnt),
+			host->net->ns.inum);
+		return PTR_ERR(clnt);
+	}
+
+	msg.rpc_proc = &clnt->cl_procinfo[proc];
+	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
+	if (status == -ECONNREFUSED) {
+		dprintk("lockd:	NSM upcall RPC failed, status=%d, forcing rebind\n",
+				status);
+		rpc_force_rebind(clnt);
+		status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
+	}
+	if (status < 0)
+		dprintk("lockd: NSM upcall RPC failed, status=%d\n",
+				status);
+	else
+		status = 0;
+
+	rpc_shutdown_client(clnt);
+	return status;
+}
+
+/**
+ * nsm_monitor - Notify a peer in case we reboot
+ * @host: pointer to nlm_host of peer to notify
+ *
+ * If this peer is not already monitored, this function sends an
+ * upcall to the local rpc.statd to record the name/address of
+ * the peer to notify in case we reboot.
+ *
+ * Returns zero if the peer is monitored by the local rpc.statd;
+ * otherwise a negative errno value is returned.
+ */
+int nsm_monitor(const struct nlm_host *host)
+{
+	struct nsm_handle *nsm = host->h_nsmhandle;
+	struct nsm_res	res;
+	int		status;
+
+	dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
+
+	if (nsm->sm_monitored)
+		return 0;
+
+	/*
+	 * Choose whether to record the caller_name or IP address of
+	 * this peer in the local rpc.statd's database.
+	 */
+	nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
+
+	status = nsm_mon_unmon(nsm, NSMPROC_MON, &res, host);
+	if (unlikely(res.status != 0))
+		status = -EIO;
+	if (unlikely(status < 0)) {
+		pr_notice_ratelimited("lockd: cannot monitor %s\n", nsm->sm_name);
+		return status;
+	}
+
+	nsm->sm_monitored = 1;
+	if (unlikely(nsm_local_state != res.state)) {
+		nsm_local_state = res.state;
+		dprintk("lockd: NSM state changed to %d\n", nsm_local_state);
+	}
+	return 0;
+}
+
+/**
+ * nsm_unmonitor - Unregister peer notification
+ * @host: pointer to nlm_host of peer to stop monitoring
+ *
+ * If this peer is monitored, this function sends an upcall to
+ * tell the local rpc.statd not to send this peer a notification
+ * when we reboot.
+ */
+void nsm_unmonitor(const struct nlm_host *host)
+{
+	struct nsm_handle *nsm = host->h_nsmhandle;
+	struct nsm_res	res;
+	int status;
+
+	if (refcount_read(&nsm->sm_count) == 1
+	 && nsm->sm_monitored && !nsm->sm_sticky) {
+		dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
+
+		status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res, host);
+		if (res.status != 0)
+			status = -EIO;
+		if (status < 0)
+			printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
+					nsm->sm_name);
+		else
+			nsm->sm_monitored = 0;
+	}
+}
+
+static struct nsm_handle *nsm_lookup_hostname(const struct list_head *nsm_handles,
+					const char *hostname, const size_t len)
+{
+	struct nsm_handle *nsm;
+
+	list_for_each_entry(nsm, nsm_handles, sm_link)
+		if (strlen(nsm->sm_name) == len &&
+		    memcmp(nsm->sm_name, hostname, len) == 0)
+			return nsm;
+	return NULL;
+}
+
+static struct nsm_handle *nsm_lookup_addr(const struct list_head *nsm_handles,
+					const struct sockaddr *sap)
+{
+	struct nsm_handle *nsm;
+
+	list_for_each_entry(nsm, nsm_handles, sm_link)
+		if (rpc_cmp_addr(nsm_addr(nsm), sap))
+			return nsm;
+	return NULL;
+}
+
+static struct nsm_handle *nsm_lookup_priv(const struct list_head *nsm_handles,
+					const struct nsm_private *priv)
+{
+	struct nsm_handle *nsm;
+
+	list_for_each_entry(nsm, nsm_handles, sm_link)
+		if (memcmp(nsm->sm_priv.data, priv->data,
+					sizeof(priv->data)) == 0)
+			return nsm;
+	return NULL;
+}
+
+/*
+ * Construct a unique cookie to match this nsm_handle to this monitored
+ * host.  It is passed to the local rpc.statd via NSMPROC_MON, and
+ * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
+ * requests.
+ *
+ * The NSM protocol requires that these cookies be unique while the
+ * system is running.  We prefer a stronger requirement of making them
+ * unique across reboots.  If user space bugs cause a stale cookie to
+ * be sent to the kernel, it could cause the wrong host to lose its
+ * lock state if cookies were not unique across reboots.
+ *
+ * The cookies are exposed only to local user space via loopback.  They
+ * do not appear on the physical network.  If we want greater security
+ * for some reason, nsm_init_private() could perform a one-way hash to
+ * obscure the contents of the cookie.
+ */
+static void nsm_init_private(struct nsm_handle *nsm)
+{
+	u64 *p = (u64 *)&nsm->sm_priv.data;
+	s64 ns;
+
+	ns = ktime_get_ns();
+	put_unaligned(ns, p);
+	put_unaligned((unsigned long)nsm, p + 1);
+}
+
+static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
+					    const size_t salen,
+					    const char *hostname,
+					    const size_t hostname_len)
+{
+	struct nsm_handle *new;
+
+	if (!hostname)
+		return NULL;
+
+	new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
+	if (unlikely(new == NULL))
+		return NULL;
+
+	refcount_set(&new->sm_count, 1);
+	new->sm_name = (char *)(new + 1);
+	memcpy(nsm_addr(new), sap, salen);
+	new->sm_addrlen = salen;
+	nsm_init_private(new);
+
+	if (rpc_ntop(nsm_addr(new), new->sm_addrbuf,
+					sizeof(new->sm_addrbuf)) == 0)
+		(void)snprintf(new->sm_addrbuf, sizeof(new->sm_addrbuf),
+				"unsupported address family");
+	memcpy(new->sm_name, hostname, hostname_len);
+	new->sm_name[hostname_len] = '\0';
+
+	return new;
+}
+
+/**
+ * nsm_get_handle - Find or create a cached nsm_handle
+ * @net: network namespace
+ * @sap: pointer to socket address of handle to find
+ * @salen: length of socket address
+ * @hostname: pointer to C string containing hostname to find
+ * @hostname_len: length of C string
+ *
+ * Behavior is modulated by the global nsm_use_hostnames variable.
+ *
+ * Returns a cached nsm_handle after bumping its ref count, or
+ * returns a fresh nsm_handle if a handle that matches @sap and/or
+ * @hostname cannot be found in the handle cache.  Returns NULL if
+ * an error occurs.
+ */
+struct nsm_handle *nsm_get_handle(const struct net *net,
+				  const struct sockaddr *sap,
+				  const size_t salen, const char *hostname,
+				  const size_t hostname_len)
+{
+	struct nsm_handle *cached, *new = NULL;
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+	if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
+		if (printk_ratelimit()) {
+			printk(KERN_WARNING "Invalid hostname \"%.*s\" "
+					    "in NFS lock request\n",
+				(int)hostname_len, hostname);
+		}
+		return NULL;
+	}
+
+retry:
+	spin_lock(&nsm_lock);
+
+	if (nsm_use_hostnames && hostname != NULL)
+		cached = nsm_lookup_hostname(&ln->nsm_handles,
+					hostname, hostname_len);
+	else
+		cached = nsm_lookup_addr(&ln->nsm_handles, sap);
+
+	if (cached != NULL) {
+		refcount_inc(&cached->sm_count);
+		spin_unlock(&nsm_lock);
+		kfree(new);
+		dprintk("lockd: found nsm_handle for %s (%s), "
+				"cnt %d\n", cached->sm_name,
+				cached->sm_addrbuf,
+				refcount_read(&cached->sm_count));
+		return cached;
+	}
+
+	if (new != NULL) {
+		list_add(&new->sm_link, &ln->nsm_handles);
+		spin_unlock(&nsm_lock);
+		dprintk("lockd: created nsm_handle for %s (%s)\n",
+				new->sm_name, new->sm_addrbuf);
+		return new;
+	}
+
+	spin_unlock(&nsm_lock);
+
+	new = nsm_create_handle(sap, salen, hostname, hostname_len);
+	if (unlikely(new == NULL))
+		return NULL;
+	goto retry;
+}
+
+/**
+ * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
+ * @net:  network namespace
+ * @info: pointer to NLMPROC_SM_NOTIFY arguments
+ *
+ * Returns a matching nsm_handle if found in the nsm cache. The returned
+ * nsm_handle's reference count is bumped. Otherwise returns NULL if some
+ * error occurred.
+ */
+struct nsm_handle *nsm_reboot_lookup(const struct net *net,
+				const struct nlm_reboot *info)
+{
+	struct nsm_handle *cached;
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+	spin_lock(&nsm_lock);
+
+	cached = nsm_lookup_priv(&ln->nsm_handles, &info->priv);
+	if (unlikely(cached == NULL)) {
+		spin_unlock(&nsm_lock);
+		dprintk("lockd: never saw rebooted peer '%.*s' before\n",
+				info->len, info->mon);
+		return cached;
+	}
+
+	refcount_inc(&cached->sm_count);
+	spin_unlock(&nsm_lock);
+
+	dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
+			cached->sm_name, cached->sm_addrbuf,
+			refcount_read(&cached->sm_count));
+	return cached;
+}
+
+/**
+ * nsm_release - Release an NSM handle
+ * @nsm: pointer to handle to be released
+ *
+ */
+void nsm_release(struct nsm_handle *nsm)
+{
+	if (refcount_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
+		list_del(&nsm->sm_link);
+		spin_unlock(&nsm_lock);
+		dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
+				nsm->sm_name, nsm->sm_addrbuf);
+		kfree(nsm);
+	}
+}
+
+/*
+ * XDR functions for NSM.
+ *
+ * See https://www.opengroup.org/ for details on the Network
+ * Status Monitor wire protocol.
+ */
+
+static void encode_nsm_string(struct xdr_stream *xdr, const char *string)
+{
+	const u32 len = strlen(string);
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4 + len);
+	xdr_encode_opaque(p, string, len);
+}
+
+/*
+ * "mon_name" specifies the host to be monitored.
+ */
+static void encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
+{
+	encode_nsm_string(xdr, argp->mon_name);
+}
+
+/*
+ * The "my_id" argument specifies the hostname and RPC procedure
+ * to be called when the status manager receives notification
+ * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
+ * has changed.
+ */
+static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
+{
+	__be32 *p;
+
+	encode_nsm_string(xdr, argp->nodename);
+	p = xdr_reserve_space(xdr, 4 + 4 + 4);
+	*p++ = cpu_to_be32(argp->prog);
+	*p++ = cpu_to_be32(argp->vers);
+	*p = cpu_to_be32(argp->proc);
+}
+
+/*
+ * The "mon_id" argument specifies the non-private arguments
+ * of an NSMPROC_MON or NSMPROC_UNMON call.
+ */
+static void encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
+{
+	encode_mon_name(xdr, argp);
+	encode_my_id(xdr, argp);
+}
+
+/*
+ * The "priv" argument may contain private information required
+ * by the NSMPROC_MON call. This information will be supplied in the
+ * NLMPROC_SM_NOTIFY call.
+ */
+static void encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
+	xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
+}
+
+static void nsm_xdr_enc_mon(struct rpc_rqst *req, struct xdr_stream *xdr,
+			    const void *argp)
+{
+	encode_mon_id(xdr, argp);
+	encode_priv(xdr, argp);
+}
+
+static void nsm_xdr_enc_unmon(struct rpc_rqst *req, struct xdr_stream *xdr,
+			      const void *argp)
+{
+	encode_mon_id(xdr, argp);
+}
+
+static int nsm_xdr_dec_stat_res(struct rpc_rqst *rqstp,
+				struct xdr_stream *xdr,
+				void *data)
+{
+	struct nsm_res *resp = data;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4 + 4);
+	if (unlikely(p == NULL))
+		return -EIO;
+	resp->status = be32_to_cpup(p++);
+	resp->state = be32_to_cpup(p);
+
+	dprintk("lockd: %s status %d state %d\n",
+		__func__, resp->status, resp->state);
+	return 0;
+}
+
+static int nsm_xdr_dec_stat(struct rpc_rqst *rqstp,
+			    struct xdr_stream *xdr,
+			    void *data)
+{
+	struct nsm_res *resp = data;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -EIO;
+	resp->state = be32_to_cpup(p);
+
+	dprintk("lockd: %s state %d\n", __func__, resp->state);
+	return 0;
+}
+
+#define SM_my_name_sz	(1+XDR_QUADLEN(SM_MAXSTRLEN))
+#define SM_my_id_sz	(SM_my_name_sz+3)
+#define SM_mon_name_sz	(1+XDR_QUADLEN(SM_MAXSTRLEN))
+#define SM_mon_id_sz	(SM_mon_name_sz+SM_my_id_sz)
+#define SM_priv_sz	(XDR_QUADLEN(SM_PRIV_SIZE))
+#define SM_mon_sz	(SM_mon_id_sz+SM_priv_sz)
+#define SM_monres_sz	2
+#define SM_unmonres_sz	1
+
+static const struct rpc_procinfo nsm_procedures[] = {
+[NSMPROC_MON] = {
+		.p_proc		= NSMPROC_MON,
+		.p_encode	= nsm_xdr_enc_mon,
+		.p_decode	= nsm_xdr_dec_stat_res,
+		.p_arglen	= SM_mon_sz,
+		.p_replen	= SM_monres_sz,
+		.p_statidx	= NSMPROC_MON,
+		.p_name		= "MONITOR",
+	},
+[NSMPROC_UNMON] = {
+		.p_proc		= NSMPROC_UNMON,
+		.p_encode	= nsm_xdr_enc_unmon,
+		.p_decode	= nsm_xdr_dec_stat,
+		.p_arglen	= SM_mon_id_sz,
+		.p_replen	= SM_unmonres_sz,
+		.p_statidx	= NSMPROC_UNMON,
+		.p_name		= "UNMONITOR",
+	},
+};
+
+static unsigned int nsm_version1_counts[ARRAY_SIZE(nsm_procedures)];
+static const struct rpc_version nsm_version1 = {
+	.number		= 1,
+	.nrprocs	= ARRAY_SIZE(nsm_procedures),
+	.procs		= nsm_procedures,
+	.counts		= nsm_version1_counts,
+};
+
+static const struct rpc_version *nsm_version[] = {
+	[1] = &nsm_version1,
+};
+
+static struct rpc_stat		nsm_stats;
+
+static const struct rpc_program nsm_program = {
+	.name		= "statd",
+	.number		= NSM_PROGRAM,
+	.nrvers		= ARRAY_SIZE(nsm_version),
+	.version	= nsm_version,
+	.stats		= &nsm_stats
+};
diff --git a/fs/lockd/netns.h b/fs/lockd/netns.h
new file mode 100644
index 0000000000..17432c445f
--- /dev/null
+++ b/fs/lockd/netns.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LOCKD_NETNS_H__
+#define __LOCKD_NETNS_H__
+
+#include <linux/fs.h>
+#include <linux/filelock.h>
+#include <net/netns/generic.h>
+
+struct lockd_net {
+	unsigned int nlmsvc_users;
+	unsigned long next_gc;
+	unsigned long nrhosts;
+
+	struct delayed_work grace_period_end;
+	struct lock_manager lockd_manager;
+
+	struct list_head nsm_handles;
+};
+
+extern unsigned int lockd_net_id;
+
+#endif
diff --git a/fs/lockd/procfs.c b/fs/lockd/procfs.c
new file mode 100644
index 0000000000..a01f08c8c2
--- /dev/null
+++ b/fs/lockd/procfs.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Procfs support for lockd
+ *
+ * Copyright (c) 2014 Jeff Layton <jlayton@primarydata.com>
+ */
+
+#include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/module.h>
+#include <linux/nsproxy.h>
+#include <net/net_namespace.h>
+
+#include "netns.h"
+#include "procfs.h"
+
+/*
+ * We only allow strings that start with 'Y', 'y', or '1'.
+ */
+static ssize_t
+nlm_end_grace_write(struct file *file, const char __user *buf, size_t size,
+		    loff_t *pos)
+{
+	char *data;
+	struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
+					   lockd_net_id);
+
+	if (size < 1)
+		return -EINVAL;
+
+	data = simple_transaction_get(file, buf, size);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	switch(data[0]) {
+	case 'Y':
+	case 'y':
+	case '1':
+		locks_end_grace(&ln->lockd_manager);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return size;
+}
+
+static ssize_t
+nlm_end_grace_read(struct file *file, char __user *buf, size_t size,
+		   loff_t *pos)
+{
+	struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
+					   lockd_net_id);
+	char resp[3];
+
+	resp[0] = list_empty(&ln->lockd_manager.list) ? 'Y' : 'N';
+	resp[1] = '\n';
+	resp[2] = '\0';
+
+	return simple_read_from_buffer(buf, size, pos, resp, sizeof(resp));
+}
+
+static const struct proc_ops lockd_end_grace_proc_ops = {
+	.proc_write	= nlm_end_grace_write,
+	.proc_read	= nlm_end_grace_read,
+	.proc_lseek	= default_llseek,
+	.proc_release	= simple_transaction_release,
+};
+
+int __init
+lockd_create_procfs(void)
+{
+	struct proc_dir_entry *entry;
+
+	entry = proc_mkdir("fs/lockd", NULL);
+	if (!entry)
+		return -ENOMEM;
+	entry = proc_create("nlm_end_grace", S_IRUGO|S_IWUSR, entry,
+			    &lockd_end_grace_proc_ops);
+	if (!entry) {
+		remove_proc_entry("fs/lockd", NULL);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+void __exit
+lockd_remove_procfs(void)
+{
+	remove_proc_entry("fs/lockd/nlm_end_grace", NULL);
+	remove_proc_entry("fs/lockd", NULL);
+}
diff --git a/fs/lockd/procfs.h b/fs/lockd/procfs.h
new file mode 100644
index 0000000000..ba9a82f4ce
--- /dev/null
+++ b/fs/lockd/procfs.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Procfs support for lockd
+ *
+ * Copyright (c) 2014 Jeff Layton <jlayton@primarydata.com>
+ */
+#ifndef _LOCKD_PROCFS_H
+#define _LOCKD_PROCFS_H
+
+#if IS_ENABLED(CONFIG_PROC_FS)
+int lockd_create_procfs(void);
+void lockd_remove_procfs(void);
+#else
+static inline int
+lockd_create_procfs(void)
+{
+	return 0;
+}
+
+static inline void
+lockd_remove_procfs(void)
+{
+	return;
+}
+#endif /* IS_ENABLED(CONFIG_PROC_FS) */
+
+#endif /* _LOCKD_PROCFS_H */
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
new file mode 100644
index 0000000000..6579948070
--- /dev/null
+++ b/fs/lockd/svc.c
@@ -0,0 +1,728 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/fs/lockd/svc.c
+ *
+ * This is the central lockd service.
+ *
+ * FIXME: Separate the lockd NFS server functionality from the lockd NFS
+ * 	  client functionality. Oh why didn't Sun create two separate
+ *	  services in the first place?
+ *
+ * Authors:	Olaf Kirch (okir@monad.swb.de)
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sysctl.h>
+#include <linux/moduleparam.h>
+
+#include <linux/sched/signal.h>
+#include <linux/errno.h>
+#include <linux/in.h>
+#include <linux/uio.h>
+#include <linux/smp.h>
+#include <linux/mutex.h>
+#include <linux/kthread.h>
+#include <linux/freezer.h>
+#include <linux/inetdevice.h>
+
+#include <linux/sunrpc/types.h>
+#include <linux/sunrpc/stats.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include <net/ip.h>
+#include <net/addrconf.h>
+#include <net/ipv6.h>
+#include <linux/lockd/lockd.h>
+#include <linux/nfs.h>
+
+#include "netns.h"
+#include "procfs.h"
+
+#define NLMDBG_FACILITY		NLMDBG_SVC
+#define LOCKD_BUFSIZE		(1024 + NLMSVC_XDRSIZE)
+
+static struct svc_program	nlmsvc_program;
+
+const struct nlmsvc_binding	*nlmsvc_ops;
+EXPORT_SYMBOL_GPL(nlmsvc_ops);
+
+static DEFINE_MUTEX(nlmsvc_mutex);
+static unsigned int		nlmsvc_users;
+static struct svc_serv		*nlmsvc_serv;
+unsigned long			nlmsvc_timeout;
+
+static void nlmsvc_request_retry(struct timer_list *tl)
+{
+	svc_wake_up(nlmsvc_serv);
+}
+DEFINE_TIMER(nlmsvc_retry, nlmsvc_request_retry);
+
+unsigned int lockd_net_id;
+
+/*
+ * These can be set at insmod time (useful for NFS as root filesystem),
+ * and also changed through the sysctl interface.  -- Jamie Lokier, Aug 2003
+ */
+static unsigned long		nlm_grace_period;
+static unsigned long		nlm_timeout = LOCKD_DFLT_TIMEO;
+static int			nlm_udpport, nlm_tcpport;
+
+/* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */
+static unsigned int		nlm_max_connections = 1024;
+
+/*
+ * Constants needed for the sysctl interface.
+ */
+static const unsigned long	nlm_grace_period_min = 0;
+static const unsigned long	nlm_grace_period_max = 240;
+static const unsigned long	nlm_timeout_min = 3;
+static const unsigned long	nlm_timeout_max = 20;
+
+#ifdef CONFIG_SYSCTL
+static const int		nlm_port_min = 0, nlm_port_max = 65535;
+static struct ctl_table_header * nlm_sysctl_table;
+#endif
+
+static unsigned long get_lockd_grace_period(void)
+{
+	/* Note: nlm_timeout should always be nonzero */
+	if (nlm_grace_period)
+		return roundup(nlm_grace_period, nlm_timeout) * HZ;
+	else
+		return nlm_timeout * 5 * HZ;
+}
+
+static void grace_ender(struct work_struct *grace)
+{
+	struct delayed_work *dwork = to_delayed_work(grace);
+	struct lockd_net *ln = container_of(dwork, struct lockd_net,
+					    grace_period_end);
+
+	locks_end_grace(&ln->lockd_manager);
+}
+
+static void set_grace_period(struct net *net)
+{
+	unsigned long grace_period = get_lockd_grace_period();
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+	locks_start_grace(net, &ln->lockd_manager);
+	cancel_delayed_work_sync(&ln->grace_period_end);
+	schedule_delayed_work(&ln->grace_period_end, grace_period);
+}
+
+/*
+ * This is the lockd kernel thread
+ */
+static int
+lockd(void *vrqstp)
+{
+	struct svc_rqst *rqstp = vrqstp;
+	struct net *net = &init_net;
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+	/* try_to_freeze() is called from svc_recv() */
+	set_freezable();
+
+	dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
+
+	/*
+	 * The main request loop. We don't terminate until the last
+	 * NFS mount or NFS daemon has gone away.
+	 */
+	while (!kthread_should_stop()) {
+		/* update sv_maxconn if it has changed */
+		rqstp->rq_server->sv_maxconn = nlm_max_connections;
+
+		nlmsvc_retry_blocked();
+		svc_recv(rqstp);
+	}
+	if (nlmsvc_ops)
+		nlmsvc_invalidate_all();
+	nlm_shutdown_hosts();
+	cancel_delayed_work_sync(&ln->grace_period_end);
+	locks_end_grace(&ln->lockd_manager);
+
+	dprintk("lockd_down: service stopped\n");
+
+	svc_exit_thread(rqstp);
+	return 0;
+}
+
+static int create_lockd_listener(struct svc_serv *serv, const char *name,
+				 struct net *net, const int family,
+				 const unsigned short port,
+				 const struct cred *cred)
+{
+	struct svc_xprt *xprt;
+
+	xprt = svc_find_xprt(serv, name, net, family, 0);
+	if (xprt == NULL)
+		return svc_xprt_create(serv, name, net, family, port,
+				       SVC_SOCK_DEFAULTS, cred);
+	svc_xprt_put(xprt);
+	return 0;
+}
+
+static int create_lockd_family(struct svc_serv *serv, struct net *net,
+			       const int family, const struct cred *cred)
+{
+	int err;
+
+	err = create_lockd_listener(serv, "udp", net, family, nlm_udpport,
+			cred);
+	if (err < 0)
+		return err;
+
+	return create_lockd_listener(serv, "tcp", net, family, nlm_tcpport,
+			cred);
+}
+
+/*
+ * Ensure there are active UDP and TCP listeners for lockd.
+ *
+ * Even if we have only TCP NFS mounts and/or TCP NFSDs, some
+ * local services (such as rpc.statd) still require UDP, and
+ * some NFS servers do not yet support NLM over TCP.
+ *
+ * Returns zero if all listeners are available; otherwise a
+ * negative errno value is returned.
+ */
+static int make_socks(struct svc_serv *serv, struct net *net,
+		const struct cred *cred)
+{
+	static int warned;
+	int err;
+
+	err = create_lockd_family(serv, net, PF_INET, cred);
+	if (err < 0)
+		goto out_err;
+
+	err = create_lockd_family(serv, net, PF_INET6, cred);
+	if (err < 0 && err != -EAFNOSUPPORT)
+		goto out_err;
+
+	warned = 0;
+	return 0;
+
+out_err:
+	if (warned++ == 0)
+		printk(KERN_WARNING
+			"lockd_up: makesock failed, error=%d\n", err);
+	svc_xprt_destroy_all(serv, net);
+	svc_rpcb_cleanup(serv, net);
+	return err;
+}
+
+static int lockd_up_net(struct svc_serv *serv, struct net *net,
+		const struct cred *cred)
+{
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
+	int error;
+
+	if (ln->nlmsvc_users++)
+		return 0;
+
+	error = svc_bind(serv, net);
+	if (error)
+		goto err_bind;
+
+	error = make_socks(serv, net, cred);
+	if (error < 0)
+		goto err_bind;
+	set_grace_period(net);
+	dprintk("%s: per-net data created; net=%x\n", __func__, net->ns.inum);
+	return 0;
+
+err_bind:
+	ln->nlmsvc_users--;
+	return error;
+}
+
+static void lockd_down_net(struct svc_serv *serv, struct net *net)
+{
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+	if (ln->nlmsvc_users) {
+		if (--ln->nlmsvc_users == 0) {
+			nlm_shutdown_hosts_net(net);
+			cancel_delayed_work_sync(&ln->grace_period_end);
+			locks_end_grace(&ln->lockd_manager);
+			svc_xprt_destroy_all(serv, net);
+			svc_rpcb_cleanup(serv, net);
+		}
+	} else {
+		pr_err("%s: no users! net=%x\n",
+			__func__, net->ns.inum);
+		BUG();
+	}
+}
+
+static int lockd_inetaddr_event(struct notifier_block *this,
+	unsigned long event, void *ptr)
+{
+	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
+	struct sockaddr_in sin;
+
+	if (event != NETDEV_DOWN)
+		goto out;
+
+	if (nlmsvc_serv) {
+		dprintk("lockd_inetaddr_event: removed %pI4\n",
+			&ifa->ifa_local);
+		sin.sin_family = AF_INET;
+		sin.sin_addr.s_addr = ifa->ifa_local;
+		svc_age_temp_xprts_now(nlmsvc_serv, (struct sockaddr *)&sin);
+	}
+
+out:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block lockd_inetaddr_notifier = {
+	.notifier_call = lockd_inetaddr_event,
+};
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int lockd_inet6addr_event(struct notifier_block *this,
+	unsigned long event, void *ptr)
+{
+	struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
+	struct sockaddr_in6 sin6;
+
+	if (event != NETDEV_DOWN)
+		goto out;
+
+	if (nlmsvc_serv) {
+		dprintk("lockd_inet6addr_event: removed %pI6\n", &ifa->addr);
+		sin6.sin6_family = AF_INET6;
+		sin6.sin6_addr = ifa->addr;
+		if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
+			sin6.sin6_scope_id = ifa->idev->dev->ifindex;
+		svc_age_temp_xprts_now(nlmsvc_serv, (struct sockaddr *)&sin6);
+	}
+
+out:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block lockd_inet6addr_notifier = {
+	.notifier_call = lockd_inet6addr_event,
+};
+#endif
+
+static int lockd_get(void)
+{
+	struct svc_serv *serv;
+	int error;
+
+	if (nlmsvc_serv) {
+		nlmsvc_users++;
+		return 0;
+	}
+
+	/*
+	 * Sanity check: if there's no pid,
+	 * we should be the first user ...
+	 */
+	if (nlmsvc_users)
+		printk(KERN_WARNING
+			"lockd_up: no pid, %d users??\n", nlmsvc_users);
+
+	if (!nlm_timeout)
+		nlm_timeout = LOCKD_DFLT_TIMEO;
+	nlmsvc_timeout = nlm_timeout * HZ;
+
+	serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, lockd);
+	if (!serv) {
+		printk(KERN_WARNING "lockd_up: create service failed\n");
+		return -ENOMEM;
+	}
+
+	serv->sv_maxconn = nlm_max_connections;
+	error = svc_set_num_threads(serv, NULL, 1);
+	/* The thread now holds the only reference */
+	svc_put(serv);
+	if (error < 0)
+		return error;
+
+	nlmsvc_serv = serv;
+	register_inetaddr_notifier(&lockd_inetaddr_notifier);
+#if IS_ENABLED(CONFIG_IPV6)
+	register_inet6addr_notifier(&lockd_inet6addr_notifier);
+#endif
+	dprintk("lockd_up: service created\n");
+	nlmsvc_users++;
+	return 0;
+}
+
+static void lockd_put(void)
+{
+	if (WARN(nlmsvc_users <= 0, "lockd_down: no users!\n"))
+		return;
+	if (--nlmsvc_users)
+		return;
+
+	unregister_inetaddr_notifier(&lockd_inetaddr_notifier);
+#if IS_ENABLED(CONFIG_IPV6)
+	unregister_inet6addr_notifier(&lockd_inet6addr_notifier);
+#endif
+
+	svc_set_num_threads(nlmsvc_serv, NULL, 0);
+	timer_delete_sync(&nlmsvc_retry);
+	nlmsvc_serv = NULL;
+	dprintk("lockd_down: service destroyed\n");
+}
+
+/*
+ * Bring up the lockd process if it's not already up.
+ */
+int lockd_up(struct net *net, const struct cred *cred)
+{
+	int error;
+
+	mutex_lock(&nlmsvc_mutex);
+
+	error = lockd_get();
+	if (error)
+		goto err;
+
+	error = lockd_up_net(nlmsvc_serv, net, cred);
+	if (error < 0) {
+		lockd_put();
+		goto err;
+	}
+
+err:
+	mutex_unlock(&nlmsvc_mutex);
+	return error;
+}
+EXPORT_SYMBOL_GPL(lockd_up);
+
+/*
+ * Decrement the user count and bring down lockd if we're the last.
+ */
+void
+lockd_down(struct net *net)
+{
+	mutex_lock(&nlmsvc_mutex);
+	lockd_down_net(nlmsvc_serv, net);
+	lockd_put();
+	mutex_unlock(&nlmsvc_mutex);
+}
+EXPORT_SYMBOL_GPL(lockd_down);
+
+#ifdef CONFIG_SYSCTL
+
+/*
+ * Sysctl parameters (same as module parameters, different interface).
+ */
+
+static struct ctl_table nlm_sysctls[] = {
+	{
+		.procname	= "nlm_grace_period",
+		.data		= &nlm_grace_period,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+		.extra1		= (unsigned long *) &nlm_grace_period_min,
+		.extra2		= (unsigned long *) &nlm_grace_period_max,
+	},
+	{
+		.procname	= "nlm_timeout",
+		.data		= &nlm_timeout,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+		.extra1		= (unsigned long *) &nlm_timeout_min,
+		.extra2		= (unsigned long *) &nlm_timeout_max,
+	},
+	{
+		.procname	= "nlm_udpport",
+		.data		= &nlm_udpport,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (int *) &nlm_port_min,
+		.extra2		= (int *) &nlm_port_max,
+	},
+	{
+		.procname	= "nlm_tcpport",
+		.data		= &nlm_tcpport,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (int *) &nlm_port_min,
+		.extra2		= (int *) &nlm_port_max,
+	},
+	{
+		.procname	= "nsm_use_hostnames",
+		.data		= &nsm_use_hostnames,
+		.maxlen		= sizeof(bool),
+		.mode		= 0644,
+		.proc_handler	= proc_dobool,
+	},
+	{
+		.procname	= "nsm_local_state",
+		.data		= &nsm_local_state,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{ }
+};
+
+#endif	/* CONFIG_SYSCTL */
+
+/*
+ * Module (and sysfs) parameters.
+ */
+
+#define param_set_min_max(name, type, which_strtol, min, max)		\
+static int param_set_##name(const char *val, const struct kernel_param *kp) \
+{									\
+	char *endp;							\
+	__typeof__(type) num = which_strtol(val, &endp, 0);		\
+	if (endp == val || *endp || num < (min) || num > (max))		\
+		return -EINVAL;						\
+	*((type *) kp->arg) = num;					\
+	return 0;							\
+}
+
+static inline int is_callback(u32 proc)
+{
+	return proc == NLMPROC_GRANTED
+		|| proc == NLMPROC_GRANTED_MSG
+		|| proc == NLMPROC_TEST_RES
+		|| proc == NLMPROC_LOCK_RES
+		|| proc == NLMPROC_CANCEL_RES
+		|| proc == NLMPROC_UNLOCK_RES
+		|| proc == NLMPROC_NSM_NOTIFY;
+}
+
+
+static enum svc_auth_status lockd_authenticate(struct svc_rqst *rqstp)
+{
+	rqstp->rq_client = NULL;
+	switch (rqstp->rq_authop->flavour) {
+		case RPC_AUTH_NULL:
+		case RPC_AUTH_UNIX:
+			rqstp->rq_auth_stat = rpc_auth_ok;
+			if (rqstp->rq_proc == 0)
+				return SVC_OK;
+			if (is_callback(rqstp->rq_proc)) {
+				/* Leave it to individual procedures to
+				 * call nlmsvc_lookup_host(rqstp)
+				 */
+				return SVC_OK;
+			}
+			return svc_set_client(rqstp);
+	}
+	rqstp->rq_auth_stat = rpc_autherr_badcred;
+	return SVC_DENIED;
+}
+
+
+param_set_min_max(port, int, simple_strtol, 0, 65535)
+param_set_min_max(grace_period, unsigned long, simple_strtoul,
+		  nlm_grace_period_min, nlm_grace_period_max)
+param_set_min_max(timeout, unsigned long, simple_strtoul,
+		  nlm_timeout_min, nlm_timeout_max)
+
+MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
+MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
+MODULE_LICENSE("GPL");
+
+module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
+		  &nlm_grace_period, 0644);
+module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
+		  &nlm_timeout, 0644);
+module_param_call(nlm_udpport, param_set_port, param_get_int,
+		  &nlm_udpport, 0644);
+module_param_call(nlm_tcpport, param_set_port, param_get_int,
+		  &nlm_tcpport, 0644);
+module_param(nsm_use_hostnames, bool, 0644);
+module_param(nlm_max_connections, uint, 0644);
+
+static int lockd_init_net(struct net *net)
+{
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+	INIT_DELAYED_WORK(&ln->grace_period_end, grace_ender);
+	INIT_LIST_HEAD(&ln->lockd_manager.list);
+	ln->lockd_manager.block_opens = false;
+	INIT_LIST_HEAD(&ln->nsm_handles);
+	return 0;
+}
+
+static void lockd_exit_net(struct net *net)
+{
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+	WARN_ONCE(!list_empty(&ln->lockd_manager.list),
+		  "net %x %s: lockd_manager.list is not empty\n",
+		  net->ns.inum, __func__);
+	WARN_ONCE(!list_empty(&ln->nsm_handles),
+		  "net %x %s: nsm_handles list is not empty\n",
+		  net->ns.inum, __func__);
+	WARN_ONCE(delayed_work_pending(&ln->grace_period_end),
+		  "net %x %s: grace_period_end was not cancelled\n",
+		  net->ns.inum, __func__);
+}
+
+static struct pernet_operations lockd_net_ops = {
+	.init = lockd_init_net,
+	.exit = lockd_exit_net,
+	.id = &lockd_net_id,
+	.size = sizeof(struct lockd_net),
+};
+
+
+/*
+ * Initialising and terminating the module.
+ */
+
+static int __init init_nlm(void)
+{
+	int err;
+
+#ifdef CONFIG_SYSCTL
+	err = -ENOMEM;
+	nlm_sysctl_table = register_sysctl("fs/nfs", nlm_sysctls);
+	if (nlm_sysctl_table == NULL)
+		goto err_sysctl;
+#endif
+	err = register_pernet_subsys(&lockd_net_ops);
+	if (err)
+		goto err_pernet;
+
+	err = lockd_create_procfs();
+	if (err)
+		goto err_procfs;
+
+	return 0;
+
+err_procfs:
+	unregister_pernet_subsys(&lockd_net_ops);
+err_pernet:
+#ifdef CONFIG_SYSCTL
+	unregister_sysctl_table(nlm_sysctl_table);
+err_sysctl:
+#endif
+	return err;
+}
+
+static void __exit exit_nlm(void)
+{
+	/* FIXME: delete all NLM clients */
+	nlm_shutdown_hosts();
+	lockd_remove_procfs();
+	unregister_pernet_subsys(&lockd_net_ops);
+#ifdef CONFIG_SYSCTL
+	unregister_sysctl_table(nlm_sysctl_table);
+#endif
+}
+
+module_init(init_nlm);
+module_exit(exit_nlm);
+
+/**
+ * nlmsvc_dispatch - Process an NLM Request
+ * @rqstp: incoming request
+ *
+ * Return values:
+ *  %0: Processing complete; do not send a Reply
+ *  %1: Processing complete; send Reply in rqstp->rq_res
+ */
+static int nlmsvc_dispatch(struct svc_rqst *rqstp)
+{
+	const struct svc_procedure *procp = rqstp->rq_procinfo;
+	__be32 *statp = rqstp->rq_accept_statp;
+
+	if (!procp->pc_decode(rqstp, &rqstp->rq_arg_stream))
+		goto out_decode_err;
+
+	*statp = procp->pc_func(rqstp);
+	if (*statp == rpc_drop_reply)
+		return 0;
+	if (*statp != rpc_success)
+		return 1;
+
+	if (!procp->pc_encode(rqstp, &rqstp->rq_res_stream))
+		goto out_encode_err;
+
+	return 1;
+
+out_decode_err:
+	*statp = rpc_garbage_args;
+	return 1;
+
+out_encode_err:
+	*statp = rpc_system_err;
+	return 1;
+}
+
+/*
+ * Define NLM program and procedures
+ */
+static DEFINE_PER_CPU_ALIGNED(unsigned long, nlmsvc_version1_count[17]);
+static const struct svc_version	nlmsvc_version1 = {
+	.vs_vers	= 1,
+	.vs_nproc	= 17,
+	.vs_proc	= nlmsvc_procedures,
+	.vs_count	= nlmsvc_version1_count,
+	.vs_dispatch	= nlmsvc_dispatch,
+	.vs_xdrsize	= NLMSVC_XDRSIZE,
+};
+
+static DEFINE_PER_CPU_ALIGNED(unsigned long,
+			      nlmsvc_version3_count[ARRAY_SIZE(nlmsvc_procedures)]);
+static const struct svc_version	nlmsvc_version3 = {
+	.vs_vers	= 3,
+	.vs_nproc	= ARRAY_SIZE(nlmsvc_procedures),
+	.vs_proc	= nlmsvc_procedures,
+	.vs_count	= nlmsvc_version3_count,
+	.vs_dispatch	= nlmsvc_dispatch,
+	.vs_xdrsize	= NLMSVC_XDRSIZE,
+};
+
+#ifdef CONFIG_LOCKD_V4
+static DEFINE_PER_CPU_ALIGNED(unsigned long,
+			      nlmsvc_version4_count[ARRAY_SIZE(nlmsvc_procedures4)]);
+static const struct svc_version	nlmsvc_version4 = {
+	.vs_vers	= 4,
+	.vs_nproc	= ARRAY_SIZE(nlmsvc_procedures4),
+	.vs_proc	= nlmsvc_procedures4,
+	.vs_count	= nlmsvc_version4_count,
+	.vs_dispatch	= nlmsvc_dispatch,
+	.vs_xdrsize	= NLMSVC_XDRSIZE,
+};
+#endif
+
+static const struct svc_version *nlmsvc_version[] = {
+	[1] = &nlmsvc_version1,
+	[3] = &nlmsvc_version3,
+#ifdef CONFIG_LOCKD_V4
+	[4] = &nlmsvc_version4,
+#endif
+};
+
+static struct svc_stat		nlmsvc_stats;
+
+#define NLM_NRVERS	ARRAY_SIZE(nlmsvc_version)
+static struct svc_program	nlmsvc_program = {
+	.pg_prog		= NLM_PROGRAM,		/* program number */
+	.pg_nvers		= NLM_NRVERS,		/* number of entries in nlmsvc_version */
+	.pg_vers		= nlmsvc_version,	/* version table */
+	.pg_name		= "lockd",		/* service name */
+	.pg_class		= "nfsd",		/* share authentication with nfsd */
+	.pg_stats		= &nlmsvc_stats,	/* stats table */
+	.pg_authenticate	= &lockd_authenticate,	/* export authentication */
+	.pg_init_request	= svc_generic_init_request,
+	.pg_rpcbind_set		= svc_generic_rpcbind_set,
+};
diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
new file mode 100644
index 0000000000..b72023a6b4
--- /dev/null
+++ b/fs/lockd/svc4proc.c
@@ -0,0 +1,760 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/lockd/svc4proc.c
+ *
+ * Lockd server procedures. We don't implement the NLM_*_RES 
+ * procedures because we don't use the async procedures.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/lockd/lockd.h>
+#include <linux/lockd/share.h>
+#include <linux/sunrpc/svc_xprt.h>
+
+#define NLMDBG_FACILITY		NLMDBG_CLIENT
+
+/*
+ * Obtain client and file from arguments
+ */
+static __be32
+nlm4svc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
+			struct nlm_host **hostp, struct nlm_file **filp)
+{
+	struct nlm_host		*host = NULL;
+	struct nlm_file		*file = NULL;
+	struct nlm_lock		*lock = &argp->lock;
+	__be32			error = 0;
+
+	/* nfsd callbacks must have been installed for this procedure */
+	if (!nlmsvc_ops)
+		return nlm_lck_denied_nolocks;
+
+	if (lock->lock_start > OFFSET_MAX ||
+	    (lock->lock_len && ((lock->lock_len - 1) > (OFFSET_MAX - lock->lock_start))))
+		return nlm4_fbig;
+
+	/* Obtain host handle */
+	if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
+	 || (argp->monitor && nsm_monitor(host) < 0))
+		goto no_locks;
+	*hostp = host;
+
+	/* Obtain file pointer. Not used by FREE_ALL call. */
+	if (filp != NULL) {
+		int mode = lock_to_openmode(&lock->fl);
+
+		error = nlm_lookup_file(rqstp, &file, lock);
+		if (error)
+			goto no_locks;
+		*filp = file;
+
+		/* Set up the missing parts of the file_lock structure */
+		lock->fl.fl_flags = FL_POSIX;
+		lock->fl.fl_file  = file->f_file[mode];
+		lock->fl.fl_pid = current->tgid;
+		lock->fl.fl_start = (loff_t)lock->lock_start;
+		lock->fl.fl_end = lock->lock_len ?
+				   (loff_t)(lock->lock_start + lock->lock_len - 1) :
+				   OFFSET_MAX;
+		lock->fl.fl_lmops = &nlmsvc_lock_operations;
+		nlmsvc_locks_init_private(&lock->fl, host, (pid_t)lock->svid);
+		if (!lock->fl.fl_owner) {
+			/* lockowner allocation has failed */
+			nlmsvc_release_host(host);
+			return nlm_lck_denied_nolocks;
+		}
+	}
+
+	return 0;
+
+no_locks:
+	nlmsvc_release_host(host);
+ 	if (error)
+		return error;	
+	return nlm_lck_denied_nolocks;
+}
+
+/*
+ * NULL: Test for presence of service
+ */
+static __be32
+nlm4svc_proc_null(struct svc_rqst *rqstp)
+{
+	dprintk("lockd: NULL          called\n");
+	return rpc_success;
+}
+
+/*
+ * TEST: Check for conflicting lock
+ */
+static __be32
+__nlm4svc_proc_test(struct svc_rqst *rqstp, struct nlm_res *resp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_host	*host;
+	struct nlm_file	*file;
+	struct nlm_lockowner *test_owner;
+	__be32 rc = rpc_success;
+
+	dprintk("lockd: TEST4        called\n");
+	resp->cookie = argp->cookie;
+
+	/* Obtain client and file */
+	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
+		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
+
+	test_owner = argp->lock.fl.fl_owner;
+	/* Now check for conflicting locks */
+	resp->status = nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie);
+	if (resp->status == nlm_drop_reply)
+		rc = rpc_drop_reply;
+	else
+		dprintk("lockd: TEST4        status %d\n", ntohl(resp->status));
+
+	nlmsvc_put_lockowner(test_owner);
+	nlmsvc_release_host(host);
+	nlm_release_file(file);
+	return rc;
+}
+
+static __be32
+nlm4svc_proc_test(struct svc_rqst *rqstp)
+{
+	return __nlm4svc_proc_test(rqstp, rqstp->rq_resp);
+}
+
+static __be32
+__nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_res *resp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_host	*host;
+	struct nlm_file	*file;
+	__be32 rc = rpc_success;
+
+	dprintk("lockd: LOCK          called\n");
+
+	resp->cookie = argp->cookie;
+
+	/* Obtain client and file */
+	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
+		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
+
+#if 0
+	/* If supplied state doesn't match current state, we assume it's
+	 * an old request that time-warped somehow. Any error return would
+	 * do in this case because it's irrelevant anyway.
+	 *
+	 * NB: We don't retrieve the remote host's state yet.
+	 */
+	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
+		resp->status = nlm_lck_denied_nolocks;
+	} else
+#endif
+
+	/* Now try to lock the file */
+	resp->status = nlmsvc_lock(rqstp, file, host, &argp->lock,
+					argp->block, &argp->cookie,
+					argp->reclaim);
+	if (resp->status == nlm_drop_reply)
+		rc = rpc_drop_reply;
+	else
+		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
+
+	nlmsvc_release_lockowner(&argp->lock);
+	nlmsvc_release_host(host);
+	nlm_release_file(file);
+	return rc;
+}
+
+static __be32
+nlm4svc_proc_lock(struct svc_rqst *rqstp)
+{
+	return __nlm4svc_proc_lock(rqstp, rqstp->rq_resp);
+}
+
+static __be32
+__nlm4svc_proc_cancel(struct svc_rqst *rqstp, struct nlm_res *resp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_host	*host;
+	struct nlm_file	*file;
+
+	dprintk("lockd: CANCEL        called\n");
+
+	resp->cookie = argp->cookie;
+
+	/* Don't accept requests during grace period */
+	if (locks_in_grace(SVC_NET(rqstp))) {
+		resp->status = nlm_lck_denied_grace_period;
+		return rpc_success;
+	}
+
+	/* Obtain client and file */
+	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
+		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
+
+	/* Try to cancel request. */
+	resp->status = nlmsvc_cancel_blocked(SVC_NET(rqstp), file, &argp->lock);
+
+	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
+	nlmsvc_release_lockowner(&argp->lock);
+	nlmsvc_release_host(host);
+	nlm_release_file(file);
+	return rpc_success;
+}
+
+static __be32
+nlm4svc_proc_cancel(struct svc_rqst *rqstp)
+{
+	return __nlm4svc_proc_cancel(rqstp, rqstp->rq_resp);
+}
+
+/*
+ * UNLOCK: release a lock
+ */
+static __be32
+__nlm4svc_proc_unlock(struct svc_rqst *rqstp, struct nlm_res *resp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_host	*host;
+	struct nlm_file	*file;
+
+	dprintk("lockd: UNLOCK        called\n");
+
+	resp->cookie = argp->cookie;
+
+	/* Don't accept new lock requests during grace period */
+	if (locks_in_grace(SVC_NET(rqstp))) {
+		resp->status = nlm_lck_denied_grace_period;
+		return rpc_success;
+	}
+
+	/* Obtain client and file */
+	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
+		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
+
+	/* Now try to remove the lock */
+	resp->status = nlmsvc_unlock(SVC_NET(rqstp), file, &argp->lock);
+
+	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
+	nlmsvc_release_lockowner(&argp->lock);
+	nlmsvc_release_host(host);
+	nlm_release_file(file);
+	return rpc_success;
+}
+
+static __be32
+nlm4svc_proc_unlock(struct svc_rqst *rqstp)
+{
+	return __nlm4svc_proc_unlock(rqstp, rqstp->rq_resp);
+}
+
+/*
+ * GRANTED: A server calls us to tell that a process' lock request
+ * was granted
+ */
+static __be32
+__nlm4svc_proc_granted(struct svc_rqst *rqstp, struct nlm_res *resp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+
+	resp->cookie = argp->cookie;
+
+	dprintk("lockd: GRANTED       called\n");
+	resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
+	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
+	return rpc_success;
+}
+
+static __be32
+nlm4svc_proc_granted(struct svc_rqst *rqstp)
+{
+	return __nlm4svc_proc_granted(rqstp, rqstp->rq_resp);
+}
+
+/*
+ * This is the generic lockd callback for async RPC calls
+ */
+static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
+{
+}
+
+static void nlm4svc_callback_release(void *data)
+{
+	nlmsvc_release_call(data);
+}
+
+static const struct rpc_call_ops nlm4svc_callback_ops = {
+	.rpc_call_done = nlm4svc_callback_exit,
+	.rpc_release = nlm4svc_callback_release,
+};
+
+/*
+ * `Async' versions of the above service routines. They aren't really,
+ * because we send the callback before the reply proper. I hope this
+ * doesn't break any clients.
+ */
+static __be32 nlm4svc_callback(struct svc_rqst *rqstp, u32 proc,
+		__be32 (*func)(struct svc_rqst *,  struct nlm_res *))
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_host	*host;
+	struct nlm_rqst	*call;
+	__be32 stat;
+
+	host = nlmsvc_lookup_host(rqstp,
+				  argp->lock.caller,
+				  argp->lock.len);
+	if (host == NULL)
+		return rpc_system_err;
+
+	call = nlm_alloc_call(host);
+	nlmsvc_release_host(host);
+	if (call == NULL)
+		return rpc_system_err;
+
+	stat = func(rqstp, &call->a_res);
+	if (stat != 0) {
+		nlmsvc_release_call(call);
+		return stat;
+	}
+
+	call->a_flags = RPC_TASK_ASYNC;
+	if (nlm_async_reply(call, proc, &nlm4svc_callback_ops) < 0)
+		return rpc_system_err;
+	return rpc_success;
+}
+
+static __be32 nlm4svc_proc_test_msg(struct svc_rqst *rqstp)
+{
+	dprintk("lockd: TEST_MSG      called\n");
+	return nlm4svc_callback(rqstp, NLMPROC_TEST_RES, __nlm4svc_proc_test);
+}
+
+static __be32 nlm4svc_proc_lock_msg(struct svc_rqst *rqstp)
+{
+	dprintk("lockd: LOCK_MSG      called\n");
+	return nlm4svc_callback(rqstp, NLMPROC_LOCK_RES, __nlm4svc_proc_lock);
+}
+
+static __be32 nlm4svc_proc_cancel_msg(struct svc_rqst *rqstp)
+{
+	dprintk("lockd: CANCEL_MSG    called\n");
+	return nlm4svc_callback(rqstp, NLMPROC_CANCEL_RES, __nlm4svc_proc_cancel);
+}
+
+static __be32 nlm4svc_proc_unlock_msg(struct svc_rqst *rqstp)
+{
+	dprintk("lockd: UNLOCK_MSG    called\n");
+	return nlm4svc_callback(rqstp, NLMPROC_UNLOCK_RES, __nlm4svc_proc_unlock);
+}
+
+static __be32 nlm4svc_proc_granted_msg(struct svc_rqst *rqstp)
+{
+	dprintk("lockd: GRANTED_MSG   called\n");
+	return nlm4svc_callback(rqstp, NLMPROC_GRANTED_RES, __nlm4svc_proc_granted);
+}
+
+/*
+ * SHARE: create a DOS share or alter existing share.
+ */
+static __be32
+nlm4svc_proc_share(struct svc_rqst *rqstp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_res *resp = rqstp->rq_resp;
+	struct nlm_host	*host;
+	struct nlm_file	*file;
+
+	dprintk("lockd: SHARE         called\n");
+
+	resp->cookie = argp->cookie;
+
+	/* Don't accept new lock requests during grace period */
+	if (locks_in_grace(SVC_NET(rqstp)) && !argp->reclaim) {
+		resp->status = nlm_lck_denied_grace_period;
+		return rpc_success;
+	}
+
+	/* Obtain client and file */
+	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
+		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
+
+	/* Now try to create the share */
+	resp->status = nlmsvc_share_file(host, file, argp);
+
+	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
+	nlmsvc_release_lockowner(&argp->lock);
+	nlmsvc_release_host(host);
+	nlm_release_file(file);
+	return rpc_success;
+}
+
+/*
+ * UNSHARE: Release a DOS share.
+ */
+static __be32
+nlm4svc_proc_unshare(struct svc_rqst *rqstp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_res *resp = rqstp->rq_resp;
+	struct nlm_host	*host;
+	struct nlm_file	*file;
+
+	dprintk("lockd: UNSHARE       called\n");
+
+	resp->cookie = argp->cookie;
+
+	/* Don't accept requests during grace period */
+	if (locks_in_grace(SVC_NET(rqstp))) {
+		resp->status = nlm_lck_denied_grace_period;
+		return rpc_success;
+	}
+
+	/* Obtain client and file */
+	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
+		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
+
+	/* Now try to lock the file */
+	resp->status = nlmsvc_unshare_file(host, file, argp);
+
+	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
+	nlmsvc_release_lockowner(&argp->lock);
+	nlmsvc_release_host(host);
+	nlm_release_file(file);
+	return rpc_success;
+}
+
+/*
+ * NM_LOCK: Create an unmonitored lock
+ */
+static __be32
+nlm4svc_proc_nm_lock(struct svc_rqst *rqstp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+
+	dprintk("lockd: NM_LOCK       called\n");
+
+	argp->monitor = 0;		/* just clean the monitor flag */
+	return nlm4svc_proc_lock(rqstp);
+}
+
+/*
+ * FREE_ALL: Release all locks and shares held by client
+ */
+static __be32
+nlm4svc_proc_free_all(struct svc_rqst *rqstp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_host	*host;
+
+	/* Obtain client */
+	if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
+		return rpc_success;
+
+	nlmsvc_free_host_resources(host);
+	nlmsvc_release_host(host);
+	return rpc_success;
+}
+
+/*
+ * SM_NOTIFY: private callback from statd (not part of official NLM proto)
+ */
+static __be32
+nlm4svc_proc_sm_notify(struct svc_rqst *rqstp)
+{
+	struct nlm_reboot *argp = rqstp->rq_argp;
+
+	dprintk("lockd: SM_NOTIFY     called\n");
+
+	if (!nlm_privileged_requester(rqstp)) {
+		char buf[RPC_MAX_ADDRBUFLEN];
+		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
+				svc_print_addr(rqstp, buf, sizeof(buf)));
+		return rpc_system_err;
+	}
+
+	nlm_host_rebooted(SVC_NET(rqstp), argp);
+	return rpc_success;
+}
+
+/*
+ * client sent a GRANTED_RES, let's remove the associated block
+ */
+static __be32
+nlm4svc_proc_granted_res(struct svc_rqst *rqstp)
+{
+	struct nlm_res *argp = rqstp->rq_argp;
+
+        if (!nlmsvc_ops)
+                return rpc_success;
+
+        dprintk("lockd: GRANTED_RES   called\n");
+
+        nlmsvc_grant_reply(&argp->cookie, argp->status);
+        return rpc_success;
+}
+
+static __be32
+nlm4svc_proc_unused(struct svc_rqst *rqstp)
+{
+	return rpc_proc_unavail;
+}
+
+
+/*
+ * NLM Server procedures.
+ */
+
+struct nlm_void			{ int dummy; };
+
+#define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
+#define	No	(1+1024/4)				/* netobj */
+#define	St	1					/* status */
+#define	Rg	4					/* range (offset + length) */
+
+const struct svc_procedure nlmsvc_procedures4[24] = {
+	[NLMPROC_NULL] = {
+		.pc_func = nlm4svc_proc_null,
+		.pc_decode = nlm4svc_decode_void,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_void),
+		.pc_argzero = sizeof(struct nlm_void),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "NULL",
+	},
+	[NLMPROC_TEST] = {
+		.pc_func = nlm4svc_proc_test,
+		.pc_decode = nlm4svc_decode_testargs,
+		.pc_encode = nlm4svc_encode_testres,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St+2+No+Rg,
+		.pc_name = "TEST",
+	},
+	[NLMPROC_LOCK] = {
+		.pc_func = nlm4svc_proc_lock,
+		.pc_decode = nlm4svc_decode_lockargs,
+		.pc_encode = nlm4svc_encode_res,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St,
+		.pc_name = "LOCK",
+	},
+	[NLMPROC_CANCEL] = {
+		.pc_func = nlm4svc_proc_cancel,
+		.pc_decode = nlm4svc_decode_cancargs,
+		.pc_encode = nlm4svc_encode_res,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St,
+		.pc_name = "CANCEL",
+	},
+	[NLMPROC_UNLOCK] = {
+		.pc_func = nlm4svc_proc_unlock,
+		.pc_decode = nlm4svc_decode_unlockargs,
+		.pc_encode = nlm4svc_encode_res,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St,
+		.pc_name = "UNLOCK",
+	},
+	[NLMPROC_GRANTED] = {
+		.pc_func = nlm4svc_proc_granted,
+		.pc_decode = nlm4svc_decode_testargs,
+		.pc_encode = nlm4svc_encode_res,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St,
+		.pc_name = "GRANTED",
+	},
+	[NLMPROC_TEST_MSG] = {
+		.pc_func = nlm4svc_proc_test_msg,
+		.pc_decode = nlm4svc_decode_testargs,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "TEST_MSG",
+	},
+	[NLMPROC_LOCK_MSG] = {
+		.pc_func = nlm4svc_proc_lock_msg,
+		.pc_decode = nlm4svc_decode_lockargs,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "LOCK_MSG",
+	},
+	[NLMPROC_CANCEL_MSG] = {
+		.pc_func = nlm4svc_proc_cancel_msg,
+		.pc_decode = nlm4svc_decode_cancargs,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "CANCEL_MSG",
+	},
+	[NLMPROC_UNLOCK_MSG] = {
+		.pc_func = nlm4svc_proc_unlock_msg,
+		.pc_decode = nlm4svc_decode_unlockargs,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "UNLOCK_MSG",
+	},
+	[NLMPROC_GRANTED_MSG] = {
+		.pc_func = nlm4svc_proc_granted_msg,
+		.pc_decode = nlm4svc_decode_testargs,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "GRANTED_MSG",
+	},
+	[NLMPROC_TEST_RES] = {
+		.pc_func = nlm4svc_proc_null,
+		.pc_decode = nlm4svc_decode_void,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_res),
+		.pc_argzero = sizeof(struct nlm_res),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "TEST_RES",
+	},
+	[NLMPROC_LOCK_RES] = {
+		.pc_func = nlm4svc_proc_null,
+		.pc_decode = nlm4svc_decode_void,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_res),
+		.pc_argzero = sizeof(struct nlm_res),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "LOCK_RES",
+	},
+	[NLMPROC_CANCEL_RES] = {
+		.pc_func = nlm4svc_proc_null,
+		.pc_decode = nlm4svc_decode_void,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_res),
+		.pc_argzero = sizeof(struct nlm_res),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "CANCEL_RES",
+	},
+	[NLMPROC_UNLOCK_RES] = {
+		.pc_func = nlm4svc_proc_null,
+		.pc_decode = nlm4svc_decode_void,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_res),
+		.pc_argzero = sizeof(struct nlm_res),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "UNLOCK_RES",
+	},
+	[NLMPROC_GRANTED_RES] = {
+		.pc_func = nlm4svc_proc_granted_res,
+		.pc_decode = nlm4svc_decode_res,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_res),
+		.pc_argzero = sizeof(struct nlm_res),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "GRANTED_RES",
+	},
+	[NLMPROC_NSM_NOTIFY] = {
+		.pc_func = nlm4svc_proc_sm_notify,
+		.pc_decode = nlm4svc_decode_reboot,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_reboot),
+		.pc_argzero = sizeof(struct nlm_reboot),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "SM_NOTIFY",
+	},
+	[17] = {
+		.pc_func = nlm4svc_proc_unused,
+		.pc_decode = nlm4svc_decode_void,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_void),
+		.pc_argzero = sizeof(struct nlm_void),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = 0,
+		.pc_name = "UNUSED",
+	},
+	[18] = {
+		.pc_func = nlm4svc_proc_unused,
+		.pc_decode = nlm4svc_decode_void,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_void),
+		.pc_argzero = sizeof(struct nlm_void),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = 0,
+		.pc_name = "UNUSED",
+	},
+	[19] = {
+		.pc_func = nlm4svc_proc_unused,
+		.pc_decode = nlm4svc_decode_void,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_void),
+		.pc_argzero = sizeof(struct nlm_void),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = 0,
+		.pc_name = "UNUSED",
+	},
+	[NLMPROC_SHARE] = {
+		.pc_func = nlm4svc_proc_share,
+		.pc_decode = nlm4svc_decode_shareargs,
+		.pc_encode = nlm4svc_encode_shareres,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St+1,
+		.pc_name = "SHARE",
+	},
+	[NLMPROC_UNSHARE] = {
+		.pc_func = nlm4svc_proc_unshare,
+		.pc_decode = nlm4svc_decode_shareargs,
+		.pc_encode = nlm4svc_encode_shareres,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St+1,
+		.pc_name = "UNSHARE",
+	},
+	[NLMPROC_NM_LOCK] = {
+		.pc_func = nlm4svc_proc_nm_lock,
+		.pc_decode = nlm4svc_decode_lockargs,
+		.pc_encode = nlm4svc_encode_res,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St,
+		.pc_name = "NM_LOCK",
+	},
+	[NLMPROC_FREE_ALL] = {
+		.pc_func = nlm4svc_proc_free_all,
+		.pc_decode = nlm4svc_decode_notify,
+		.pc_encode = nlm4svc_encode_void,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "FREE_ALL",
+	},
+};
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
new file mode 100644
index 0000000000..43aeba9de5
--- /dev/null
+++ b/fs/lockd/svclock.c
@@ -0,0 +1,1054 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/lockd/svclock.c
+ *
+ * Handling of server-side locks, mostly of the blocked variety.
+ * This is the ugliest part of lockd because we tread on very thin ice.
+ * GRANT and CANCEL calls may get stuck, meet in mid-flight, etc.
+ * IMNSHO introducing the grant callback into the NLM protocol was one
+ * of the worst ideas Sun ever had. Except maybe for the idea of doing
+ * NFS file locking at all.
+ *
+ * I'm trying hard to avoid race conditions by protecting most accesses
+ * to a file's list of blocked locks through a semaphore. The global
+ * list of blocked locks is not protected in this fashion however.
+ * Therefore, some functions (such as the RPC callback for the async grant
+ * call) move blocked locks towards the head of the list *while some other
+ * process might be traversing it*. This should not be a problem in
+ * practice, because this will only cause functions traversing the list
+ * to visit some blocks twice.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include <linux/lockd/nlm.h>
+#include <linux/lockd/lockd.h>
+#include <linux/kthread.h>
+#include <linux/exportfs.h>
+
+#define NLMDBG_FACILITY		NLMDBG_SVCLOCK
+
+#ifdef CONFIG_LOCKD_V4
+#define nlm_deadlock	nlm4_deadlock
+#else
+#define nlm_deadlock	nlm_lck_denied
+#endif
+
+static void nlmsvc_release_block(struct nlm_block *block);
+static void	nlmsvc_insert_block(struct nlm_block *block, unsigned long);
+static void	nlmsvc_remove_block(struct nlm_block *block);
+
+static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock);
+static void nlmsvc_freegrantargs(struct nlm_rqst *call);
+static const struct rpc_call_ops nlmsvc_grant_ops;
+
+/*
+ * The list of blocked locks to retry
+ */
+static LIST_HEAD(nlm_blocked);
+static DEFINE_SPINLOCK(nlm_blocked_lock);
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+static const char *nlmdbg_cookie2a(const struct nlm_cookie *cookie)
+{
+	/*
+	 * We can get away with a static buffer because this is only called
+	 * from lockd, which is single-threaded.
+	 */
+	static char buf[2*NLM_MAXCOOKIELEN+1];
+	unsigned int i, len = sizeof(buf);
+	char *p = buf;
+
+	len--;	/* allow for trailing \0 */
+	if (len < 3)
+		return "???";
+	for (i = 0 ; i < cookie->len ; i++) {
+		if (len < 2) {
+			strcpy(p-3, "...");
+			break;
+		}
+		sprintf(p, "%02x", cookie->data[i]);
+		p += 2;
+		len -= 2;
+	}
+	*p = '\0';
+
+	return buf;
+}
+#endif
+
+/*
+ * Insert a blocked lock into the global list
+ */
+static void
+nlmsvc_insert_block_locked(struct nlm_block *block, unsigned long when)
+{
+	struct nlm_block *b;
+	struct list_head *pos;
+
+	dprintk("lockd: nlmsvc_insert_block(%p, %ld)\n", block, when);
+	if (list_empty(&block->b_list)) {
+		kref_get(&block->b_count);
+	} else {
+		list_del_init(&block->b_list);
+	}
+
+	pos = &nlm_blocked;
+	if (when != NLM_NEVER) {
+		if ((when += jiffies) == NLM_NEVER)
+			when ++;
+		list_for_each(pos, &nlm_blocked) {
+			b = list_entry(pos, struct nlm_block, b_list);
+			if (time_after(b->b_when,when) || b->b_when == NLM_NEVER)
+				break;
+		}
+		/* On normal exit from the loop, pos == &nlm_blocked,
+		 * so we will be adding to the end of the list - good
+		 */
+	}
+
+	list_add_tail(&block->b_list, pos);
+	block->b_when = when;
+}
+
+static void nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
+{
+	spin_lock(&nlm_blocked_lock);
+	nlmsvc_insert_block_locked(block, when);
+	spin_unlock(&nlm_blocked_lock);
+}
+
+/*
+ * Remove a block from the global list
+ */
+static inline void
+nlmsvc_remove_block(struct nlm_block *block)
+{
+	spin_lock(&nlm_blocked_lock);
+	if (!list_empty(&block->b_list)) {
+		list_del_init(&block->b_list);
+		spin_unlock(&nlm_blocked_lock);
+		nlmsvc_release_block(block);
+		return;
+	}
+	spin_unlock(&nlm_blocked_lock);
+}
+
+/*
+ * Find a block for a given lock
+ */
+static struct nlm_block *
+nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock)
+{
+	struct nlm_block	*block;
+	struct file_lock	*fl;
+
+	dprintk("lockd: nlmsvc_lookup_block f=%p pd=%d %Ld-%Ld ty=%d\n",
+				file, lock->fl.fl_pid,
+				(long long)lock->fl.fl_start,
+				(long long)lock->fl.fl_end, lock->fl.fl_type);
+	spin_lock(&nlm_blocked_lock);
+	list_for_each_entry(block, &nlm_blocked, b_list) {
+		fl = &block->b_call->a_args.lock.fl;
+		dprintk("lockd: check f=%p pd=%d %Ld-%Ld ty=%d cookie=%s\n",
+				block->b_file, fl->fl_pid,
+				(long long)fl->fl_start,
+				(long long)fl->fl_end, fl->fl_type,
+				nlmdbg_cookie2a(&block->b_call->a_args.cookie));
+		if (block->b_file == file && nlm_compare_locks(fl, &lock->fl)) {
+			kref_get(&block->b_count);
+			spin_unlock(&nlm_blocked_lock);
+			return block;
+		}
+	}
+	spin_unlock(&nlm_blocked_lock);
+
+	return NULL;
+}
+
+static inline int nlm_cookie_match(struct nlm_cookie *a, struct nlm_cookie *b)
+{
+	if (a->len != b->len)
+		return 0;
+	if (memcmp(a->data, b->data, a->len))
+		return 0;
+	return 1;
+}
+
+/*
+ * Find a block with a given NLM cookie.
+ */
+static inline struct nlm_block *
+nlmsvc_find_block(struct nlm_cookie *cookie)
+{
+	struct nlm_block *block;
+
+	spin_lock(&nlm_blocked_lock);
+	list_for_each_entry(block, &nlm_blocked, b_list) {
+		if (nlm_cookie_match(&block->b_call->a_args.cookie,cookie))
+			goto found;
+	}
+	spin_unlock(&nlm_blocked_lock);
+
+	return NULL;
+
+found:
+	dprintk("nlmsvc_find_block(%s): block=%p\n", nlmdbg_cookie2a(cookie), block);
+	kref_get(&block->b_count);
+	spin_unlock(&nlm_blocked_lock);
+	return block;
+}
+
+/*
+ * Create a block and initialize it.
+ *
+ * Note: we explicitly set the cookie of the grant reply to that of
+ * the blocked lock request. The spec explicitly mentions that the client
+ * should _not_ rely on the callback containing the same cookie as the
+ * request, but (as I found out later) that's because some implementations
+ * do just this. Never mind the standards comittees, they support our
+ * logging industries.
+ *
+ * 10 years later: I hope we can safely ignore these old and broken
+ * clients by now. Let's fix this so we can uniquely identify an incoming
+ * GRANTED_RES message by cookie, without having to rely on the client's IP
+ * address. --okir
+ */
+static struct nlm_block *
+nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_host *host,
+		    struct nlm_file *file, struct nlm_lock *lock,
+		    struct nlm_cookie *cookie)
+{
+	struct nlm_block	*block;
+	struct nlm_rqst		*call = NULL;
+
+	call = nlm_alloc_call(host);
+	if (call == NULL)
+		return NULL;
+
+	/* Allocate memory for block, and initialize arguments */
+	block = kzalloc(sizeof(*block), GFP_KERNEL);
+	if (block == NULL)
+		goto failed;
+	kref_init(&block->b_count);
+	INIT_LIST_HEAD(&block->b_list);
+	INIT_LIST_HEAD(&block->b_flist);
+
+	if (!nlmsvc_setgrantargs(call, lock))
+		goto failed_free;
+
+	/* Set notifier function for VFS, and init args */
+	call->a_args.lock.fl.fl_flags |= FL_SLEEP;
+	call->a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations;
+	nlmclnt_next_cookie(&call->a_args.cookie);
+
+	dprintk("lockd: created block %p...\n", block);
+
+	/* Create and initialize the block */
+	block->b_daemon = rqstp->rq_server;
+	block->b_host   = host;
+	block->b_file   = file;
+	file->f_count++;
+
+	/* Add to file's list of blocks */
+	list_add(&block->b_flist, &file->f_blocks);
+
+	/* Set up RPC arguments for callback */
+	block->b_call = call;
+	call->a_flags   = RPC_TASK_ASYNC;
+	call->a_block = block;
+
+	return block;
+
+failed_free:
+	kfree(block);
+failed:
+	nlmsvc_release_call(call);
+	return NULL;
+}
+
+/*
+ * Delete a block.
+ * It is the caller's responsibility to check whether the file
+ * can be closed hereafter.
+ */
+static int nlmsvc_unlink_block(struct nlm_block *block)
+{
+	int status;
+	dprintk("lockd: unlinking block %p...\n", block);
+
+	/* Remove block from list */
+	status = locks_delete_block(&block->b_call->a_args.lock.fl);
+	nlmsvc_remove_block(block);
+	return status;
+}
+
+static void nlmsvc_free_block(struct kref *kref)
+{
+	struct nlm_block *block = container_of(kref, struct nlm_block, b_count);
+	struct nlm_file		*file = block->b_file;
+
+	dprintk("lockd: freeing block %p...\n", block);
+
+	/* Remove block from file's list of blocks */
+	list_del_init(&block->b_flist);
+	mutex_unlock(&file->f_mutex);
+
+	nlmsvc_freegrantargs(block->b_call);
+	nlmsvc_release_call(block->b_call);
+	nlm_release_file(block->b_file);
+	kfree(block);
+}
+
+static void nlmsvc_release_block(struct nlm_block *block)
+{
+	if (block != NULL)
+		kref_put_mutex(&block->b_count, nlmsvc_free_block, &block->b_file->f_mutex);
+}
+
+/*
+ * Loop over all blocks and delete blocks held by
+ * a matching host.
+ */
+void nlmsvc_traverse_blocks(struct nlm_host *host,
+			struct nlm_file *file,
+			nlm_host_match_fn_t match)
+{
+	struct nlm_block *block, *next;
+
+restart:
+	mutex_lock(&file->f_mutex);
+	spin_lock(&nlm_blocked_lock);
+	list_for_each_entry_safe(block, next, &file->f_blocks, b_flist) {
+		if (!match(block->b_host, host))
+			continue;
+		/* Do not destroy blocks that are not on
+		 * the global retry list - why? */
+		if (list_empty(&block->b_list))
+			continue;
+		kref_get(&block->b_count);
+		spin_unlock(&nlm_blocked_lock);
+		mutex_unlock(&file->f_mutex);
+		nlmsvc_unlink_block(block);
+		nlmsvc_release_block(block);
+		goto restart;
+	}
+	spin_unlock(&nlm_blocked_lock);
+	mutex_unlock(&file->f_mutex);
+}
+
+static struct nlm_lockowner *
+nlmsvc_get_lockowner(struct nlm_lockowner *lockowner)
+{
+	refcount_inc(&lockowner->count);
+	return lockowner;
+}
+
+void nlmsvc_put_lockowner(struct nlm_lockowner *lockowner)
+{
+	if (!refcount_dec_and_lock(&lockowner->count, &lockowner->host->h_lock))
+		return;
+	list_del(&lockowner->list);
+	spin_unlock(&lockowner->host->h_lock);
+	nlmsvc_release_host(lockowner->host);
+	kfree(lockowner);
+}
+
+static struct nlm_lockowner *__nlmsvc_find_lockowner(struct nlm_host *host, pid_t pid)
+{
+	struct nlm_lockowner *lockowner;
+	list_for_each_entry(lockowner, &host->h_lockowners, list) {
+		if (lockowner->pid != pid)
+			continue;
+		return nlmsvc_get_lockowner(lockowner);
+	}
+	return NULL;
+}
+
+static struct nlm_lockowner *nlmsvc_find_lockowner(struct nlm_host *host, pid_t pid)
+{
+	struct nlm_lockowner *res, *new = NULL;
+
+	spin_lock(&host->h_lock);
+	res = __nlmsvc_find_lockowner(host, pid);
+
+	if (res == NULL) {
+		spin_unlock(&host->h_lock);
+		new = kmalloc(sizeof(*res), GFP_KERNEL);
+		spin_lock(&host->h_lock);
+		res = __nlmsvc_find_lockowner(host, pid);
+		if (res == NULL && new != NULL) {
+			res = new;
+			/* fs/locks.c will manage the refcount through lock_ops */
+			refcount_set(&new->count, 1);
+			new->pid = pid;
+			new->host = nlm_get_host(host);
+			list_add(&new->list, &host->h_lockowners);
+			new = NULL;
+		}
+	}
+
+	spin_unlock(&host->h_lock);
+	kfree(new);
+	return res;
+}
+
+void
+nlmsvc_release_lockowner(struct nlm_lock *lock)
+{
+	if (lock->fl.fl_owner)
+		nlmsvc_put_lockowner(lock->fl.fl_owner);
+}
+
+void nlmsvc_locks_init_private(struct file_lock *fl, struct nlm_host *host,
+						pid_t pid)
+{
+	fl->fl_owner = nlmsvc_find_lockowner(host, pid);
+}
+
+/*
+ * Initialize arguments for GRANTED call. The nlm_rqst structure
+ * has been cleared already.
+ */
+static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
+{
+	locks_copy_lock(&call->a_args.lock.fl, &lock->fl);
+	memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh));
+	call->a_args.lock.caller = utsname()->nodename;
+	call->a_args.lock.oh.len = lock->oh.len;
+
+	/* set default data area */
+	call->a_args.lock.oh.data = call->a_owner;
+	call->a_args.lock.svid = ((struct nlm_lockowner *)lock->fl.fl_owner)->pid;
+
+	if (lock->oh.len > NLMCLNT_OHSIZE) {
+		void *data = kmalloc(lock->oh.len, GFP_KERNEL);
+		if (!data)
+			return 0;
+		call->a_args.lock.oh.data = (u8 *) data;
+	}
+
+	memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len);
+	return 1;
+}
+
+static void nlmsvc_freegrantargs(struct nlm_rqst *call)
+{
+	if (call->a_args.lock.oh.data != call->a_owner)
+		kfree(call->a_args.lock.oh.data);
+
+	locks_release_private(&call->a_args.lock.fl);
+}
+
+/*
+ * Deferred lock request handling for non-blocking lock
+ */
+static __be32
+nlmsvc_defer_lock_rqst(struct svc_rqst *rqstp, struct nlm_block *block)
+{
+	__be32 status = nlm_lck_denied_nolocks;
+
+	block->b_flags |= B_QUEUED;
+
+	nlmsvc_insert_block(block, NLM_TIMEOUT);
+
+	block->b_cache_req = &rqstp->rq_chandle;
+	if (rqstp->rq_chandle.defer) {
+		block->b_deferred_req =
+			rqstp->rq_chandle.defer(block->b_cache_req);
+		if (block->b_deferred_req != NULL)
+			status = nlm_drop_reply;
+	}
+	dprintk("lockd: nlmsvc_defer_lock_rqst block %p flags %d status %d\n",
+		block, block->b_flags, ntohl(status));
+
+	return status;
+}
+
+/*
+ * Attempt to establish a lock, and if it can't be granted, block it
+ * if required.
+ */
+__be32
+nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
+	    struct nlm_host *host, struct nlm_lock *lock, int wait,
+	    struct nlm_cookie *cookie, int reclaim)
+{
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+	struct inode		*inode = nlmsvc_file_inode(file);
+#endif
+	struct nlm_block	*block = NULL;
+	int			error;
+	int			mode;
+	int			async_block = 0;
+	__be32			ret;
+
+	dprintk("lockd: nlmsvc_lock(%s/%ld, ty=%d, pi=%d, %Ld-%Ld, bl=%d)\n",
+				inode->i_sb->s_id, inode->i_ino,
+				lock->fl.fl_type, lock->fl.fl_pid,
+				(long long)lock->fl.fl_start,
+				(long long)lock->fl.fl_end,
+				wait);
+
+	if (nlmsvc_file_file(file)->f_op->lock) {
+		async_block = wait;
+		wait = 0;
+	}
+
+	/* Lock file against concurrent access */
+	mutex_lock(&file->f_mutex);
+	/* Get existing block (in case client is busy-waiting)
+	 * or create new block
+	 */
+	block = nlmsvc_lookup_block(file, lock);
+	if (block == NULL) {
+		block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
+		ret = nlm_lck_denied_nolocks;
+		if (block == NULL)
+			goto out;
+		lock = &block->b_call->a_args.lock;
+	} else
+		lock->fl.fl_flags &= ~FL_SLEEP;
+
+	if (block->b_flags & B_QUEUED) {
+		dprintk("lockd: nlmsvc_lock deferred block %p flags %d\n",
+							block, block->b_flags);
+		if (block->b_granted) {
+			nlmsvc_unlink_block(block);
+			ret = nlm_granted;
+			goto out;
+		}
+		if (block->b_flags & B_TIMED_OUT) {
+			nlmsvc_unlink_block(block);
+			ret = nlm_lck_denied;
+			goto out;
+		}
+		ret = nlm_drop_reply;
+		goto out;
+	}
+
+	if (locks_in_grace(SVC_NET(rqstp)) && !reclaim) {
+		ret = nlm_lck_denied_grace_period;
+		goto out;
+	}
+	if (reclaim && !locks_in_grace(SVC_NET(rqstp))) {
+		ret = nlm_lck_denied_grace_period;
+		goto out;
+	}
+
+	if (!wait)
+		lock->fl.fl_flags &= ~FL_SLEEP;
+	mode = lock_to_openmode(&lock->fl);
+	error = vfs_lock_file(file->f_file[mode], F_SETLK, &lock->fl, NULL);
+	lock->fl.fl_flags &= ~FL_SLEEP;
+
+	dprintk("lockd: vfs_lock_file returned %d\n", error);
+	switch (error) {
+		case 0:
+			ret = nlm_granted;
+			goto out;
+		case -EAGAIN:
+			/*
+			 * If this is a blocking request for an
+			 * already pending lock request then we need
+			 * to put it back on lockd's block list
+			 */
+			if (wait)
+				break;
+			ret = async_block ? nlm_lck_blocked : nlm_lck_denied;
+			goto out;
+		case FILE_LOCK_DEFERRED:
+			if (wait)
+				break;
+			/* Filesystem lock operation is in progress
+			   Add it to the queue waiting for callback */
+			ret = nlmsvc_defer_lock_rqst(rqstp, block);
+			goto out;
+		case -EDEADLK:
+			ret = nlm_deadlock;
+			goto out;
+		default:			/* includes ENOLCK */
+			ret = nlm_lck_denied_nolocks;
+			goto out;
+	}
+
+	ret = nlm_lck_blocked;
+
+	/* Append to list of blocked */
+	nlmsvc_insert_block(block, NLM_NEVER);
+out:
+	mutex_unlock(&file->f_mutex);
+	nlmsvc_release_block(block);
+	dprintk("lockd: nlmsvc_lock returned %u\n", ret);
+	return ret;
+}
+
+/*
+ * Test for presence of a conflicting lock.
+ */
+__be32
+nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
+		struct nlm_host *host, struct nlm_lock *lock,
+		struct nlm_lock *conflock, struct nlm_cookie *cookie)
+{
+	int			error;
+	int			mode;
+	__be32			ret;
+
+	dprintk("lockd: nlmsvc_testlock(%s/%ld, ty=%d, %Ld-%Ld)\n",
+				nlmsvc_file_inode(file)->i_sb->s_id,
+				nlmsvc_file_inode(file)->i_ino,
+				lock->fl.fl_type,
+				(long long)lock->fl.fl_start,
+				(long long)lock->fl.fl_end);
+
+	if (locks_in_grace(SVC_NET(rqstp))) {
+		ret = nlm_lck_denied_grace_period;
+		goto out;
+	}
+
+	mode = lock_to_openmode(&lock->fl);
+	error = vfs_test_lock(file->f_file[mode], &lock->fl);
+	if (error) {
+		/* We can't currently deal with deferred test requests */
+		if (error == FILE_LOCK_DEFERRED)
+			WARN_ON_ONCE(1);
+
+		ret = nlm_lck_denied_nolocks;
+		goto out;
+	}
+
+	if (lock->fl.fl_type == F_UNLCK) {
+		ret = nlm_granted;
+		goto out;
+	}
+
+	dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n",
+		lock->fl.fl_type, (long long)lock->fl.fl_start,
+		(long long)lock->fl.fl_end);
+	conflock->caller = "somehost";	/* FIXME */
+	conflock->len = strlen(conflock->caller);
+	conflock->oh.len = 0;		/* don't return OH info */
+	conflock->svid = lock->fl.fl_pid;
+	conflock->fl.fl_type = lock->fl.fl_type;
+	conflock->fl.fl_start = lock->fl.fl_start;
+	conflock->fl.fl_end = lock->fl.fl_end;
+	locks_release_private(&lock->fl);
+
+	ret = nlm_lck_denied;
+out:
+	return ret;
+}
+
+/*
+ * Remove a lock.
+ * This implies a CANCEL call: We send a GRANT_MSG, the client replies
+ * with a GRANT_RES call which gets lost, and calls UNLOCK immediately
+ * afterwards. In this case the block will still be there, and hence
+ * must be removed.
+ */
+__be32
+nlmsvc_unlock(struct net *net, struct nlm_file *file, struct nlm_lock *lock)
+{
+	int	error = 0;
+
+	dprintk("lockd: nlmsvc_unlock(%s/%ld, pi=%d, %Ld-%Ld)\n",
+				nlmsvc_file_inode(file)->i_sb->s_id,
+				nlmsvc_file_inode(file)->i_ino,
+				lock->fl.fl_pid,
+				(long long)lock->fl.fl_start,
+				(long long)lock->fl.fl_end);
+
+	/* First, cancel any lock that might be there */
+	nlmsvc_cancel_blocked(net, file, lock);
+
+	lock->fl.fl_type = F_UNLCK;
+	lock->fl.fl_file = file->f_file[O_RDONLY];
+	if (lock->fl.fl_file)
+		error = vfs_lock_file(lock->fl.fl_file, F_SETLK,
+					&lock->fl, NULL);
+	lock->fl.fl_file = file->f_file[O_WRONLY];
+	if (lock->fl.fl_file)
+		error |= vfs_lock_file(lock->fl.fl_file, F_SETLK,
+					&lock->fl, NULL);
+
+	return (error < 0)? nlm_lck_denied_nolocks : nlm_granted;
+}
+
+/*
+ * Cancel a previously blocked request.
+ *
+ * A cancel request always overrides any grant that may currently
+ * be in progress.
+ * The calling procedure must check whether the file can be closed.
+ */
+__be32
+nlmsvc_cancel_blocked(struct net *net, struct nlm_file *file, struct nlm_lock *lock)
+{
+	struct nlm_block	*block;
+	int status = 0;
+	int mode;
+
+	dprintk("lockd: nlmsvc_cancel(%s/%ld, pi=%d, %Ld-%Ld)\n",
+				nlmsvc_file_inode(file)->i_sb->s_id,
+				nlmsvc_file_inode(file)->i_ino,
+				lock->fl.fl_pid,
+				(long long)lock->fl.fl_start,
+				(long long)lock->fl.fl_end);
+
+	if (locks_in_grace(net))
+		return nlm_lck_denied_grace_period;
+
+	mutex_lock(&file->f_mutex);
+	block = nlmsvc_lookup_block(file, lock);
+	mutex_unlock(&file->f_mutex);
+	if (block != NULL) {
+		struct file_lock *fl = &block->b_call->a_args.lock.fl;
+
+		mode = lock_to_openmode(fl);
+		vfs_cancel_lock(block->b_file->f_file[mode], fl);
+		status = nlmsvc_unlink_block(block);
+		nlmsvc_release_block(block);
+	}
+	return status ? nlm_lck_denied : nlm_granted;
+}
+
+/*
+ * This is a callback from the filesystem for VFS file lock requests.
+ * It will be used if lm_grant is defined and the filesystem can not
+ * respond to the request immediately.
+ * For SETLK or SETLKW request it will get the local posix lock.
+ * In all cases it will move the block to the head of nlm_blocked q where
+ * nlmsvc_retry_blocked() can send back a reply for SETLKW or revisit the
+ * deferred rpc for GETLK and SETLK.
+ */
+static void
+nlmsvc_update_deferred_block(struct nlm_block *block, int result)
+{
+	block->b_flags |= B_GOT_CALLBACK;
+	if (result == 0)
+		block->b_granted = 1;
+	else
+		block->b_flags |= B_TIMED_OUT;
+}
+
+static int nlmsvc_grant_deferred(struct file_lock *fl, int result)
+{
+	struct nlm_block *block;
+	int rc = -ENOENT;
+
+	spin_lock(&nlm_blocked_lock);
+	list_for_each_entry(block, &nlm_blocked, b_list) {
+		if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
+			dprintk("lockd: nlmsvc_notify_blocked block %p flags %d\n",
+							block, block->b_flags);
+			if (block->b_flags & B_QUEUED) {
+				if (block->b_flags & B_TIMED_OUT) {
+					rc = -ENOLCK;
+					break;
+				}
+				nlmsvc_update_deferred_block(block, result);
+			} else if (result == 0)
+				block->b_granted = 1;
+
+			nlmsvc_insert_block_locked(block, 0);
+			svc_wake_up(block->b_daemon);
+			rc = 0;
+			break;
+		}
+	}
+	spin_unlock(&nlm_blocked_lock);
+	if (rc == -ENOENT)
+		printk(KERN_WARNING "lockd: grant for unknown block\n");
+	return rc;
+}
+
+/*
+ * Unblock a blocked lock request. This is a callback invoked from the
+ * VFS layer when a lock on which we blocked is removed.
+ *
+ * This function doesn't grant the blocked lock instantly, but rather moves
+ * the block to the head of nlm_blocked where it can be picked up by lockd.
+ */
+static void
+nlmsvc_notify_blocked(struct file_lock *fl)
+{
+	struct nlm_block	*block;
+
+	dprintk("lockd: VFS unblock notification for block %p\n", fl);
+	spin_lock(&nlm_blocked_lock);
+	list_for_each_entry(block, &nlm_blocked, b_list) {
+		if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
+			nlmsvc_insert_block_locked(block, 0);
+			spin_unlock(&nlm_blocked_lock);
+			svc_wake_up(block->b_daemon);
+			return;
+		}
+	}
+	spin_unlock(&nlm_blocked_lock);
+	printk(KERN_WARNING "lockd: notification for unknown block!\n");
+}
+
+static fl_owner_t nlmsvc_get_owner(fl_owner_t owner)
+{
+	return nlmsvc_get_lockowner(owner);
+}
+
+static void nlmsvc_put_owner(fl_owner_t owner)
+{
+	nlmsvc_put_lockowner(owner);
+}
+
+const struct lock_manager_operations nlmsvc_lock_operations = {
+	.lm_notify = nlmsvc_notify_blocked,
+	.lm_grant = nlmsvc_grant_deferred,
+	.lm_get_owner = nlmsvc_get_owner,
+	.lm_put_owner = nlmsvc_put_owner,
+};
+
+/*
+ * Try to claim a lock that was previously blocked.
+ *
+ * Note that we use both the RPC_GRANTED_MSG call _and_ an async
+ * RPC thread when notifying the client. This seems like overkill...
+ * Here's why:
+ *  -	we don't want to use a synchronous RPC thread, otherwise
+ *	we might find ourselves hanging on a dead portmapper.
+ *  -	Some lockd implementations (e.g. HP) don't react to
+ *	RPC_GRANTED calls; they seem to insist on RPC_GRANTED_MSG calls.
+ */
+static void
+nlmsvc_grant_blocked(struct nlm_block *block)
+{
+	struct nlm_file		*file = block->b_file;
+	struct nlm_lock		*lock = &block->b_call->a_args.lock;
+	int			mode;
+	int			error;
+	loff_t			fl_start, fl_end;
+
+	dprintk("lockd: grant blocked lock %p\n", block);
+
+	kref_get(&block->b_count);
+
+	/* Unlink block request from list */
+	nlmsvc_unlink_block(block);
+
+	/* If b_granted is true this means we've been here before.
+	 * Just retry the grant callback, possibly refreshing the RPC
+	 * binding */
+	if (block->b_granted) {
+		nlm_rebind_host(block->b_host);
+		goto callback;
+	}
+
+	/* Try the lock operation again */
+	/* vfs_lock_file() can mangle fl_start and fl_end, but we need
+	 * them unchanged for the GRANT_MSG
+	 */
+	lock->fl.fl_flags |= FL_SLEEP;
+	fl_start = lock->fl.fl_start;
+	fl_end = lock->fl.fl_end;
+	mode = lock_to_openmode(&lock->fl);
+	error = vfs_lock_file(file->f_file[mode], F_SETLK, &lock->fl, NULL);
+	lock->fl.fl_flags &= ~FL_SLEEP;
+	lock->fl.fl_start = fl_start;
+	lock->fl.fl_end = fl_end;
+
+	switch (error) {
+	case 0:
+		break;
+	case FILE_LOCK_DEFERRED:
+		dprintk("lockd: lock still blocked error %d\n", error);
+		nlmsvc_insert_block(block, NLM_NEVER);
+		nlmsvc_release_block(block);
+		return;
+	default:
+		printk(KERN_WARNING "lockd: unexpected error %d in %s!\n",
+				-error, __func__);
+		nlmsvc_insert_block(block, 10 * HZ);
+		nlmsvc_release_block(block);
+		return;
+	}
+
+callback:
+	/* Lock was granted by VFS. */
+	dprintk("lockd: GRANTing blocked lock.\n");
+	block->b_granted = 1;
+
+	/* keep block on the list, but don't reattempt until the RPC
+	 * completes or the submission fails
+	 */
+	nlmsvc_insert_block(block, NLM_NEVER);
+
+	/* Call the client -- use a soft RPC task since nlmsvc_retry_blocked
+	 * will queue up a new one if this one times out
+	 */
+	error = nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG,
+				&nlmsvc_grant_ops);
+
+	/* RPC submission failed, wait a bit and retry */
+	if (error < 0)
+		nlmsvc_insert_block(block, 10 * HZ);
+}
+
+/*
+ * This is the callback from the RPC layer when the NLM_GRANTED_MSG
+ * RPC call has succeeded or timed out.
+ * Like all RPC callbacks, it is invoked by the rpciod process, so it
+ * better not sleep. Therefore, we put the blocked lock on the nlm_blocked
+ * chain once more in order to have it removed by lockd itself (which can
+ * then sleep on the file semaphore without disrupting e.g. the nfs client).
+ */
+static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
+{
+	struct nlm_rqst		*call = data;
+	struct nlm_block	*block = call->a_block;
+	unsigned long		timeout;
+
+	dprintk("lockd: GRANT_MSG RPC callback\n");
+
+	spin_lock(&nlm_blocked_lock);
+	/* if the block is not on a list at this point then it has
+	 * been invalidated. Don't try to requeue it.
+	 *
+	 * FIXME: it's possible that the block is removed from the list
+	 * after this check but before the nlmsvc_insert_block. In that
+	 * case it will be added back. Perhaps we need better locking
+	 * for nlm_blocked?
+	 */
+	if (list_empty(&block->b_list))
+		goto out;
+
+	/* Technically, we should down the file semaphore here. Since we
+	 * move the block towards the head of the queue only, no harm
+	 * can be done, though. */
+	if (task->tk_status < 0) {
+		/* RPC error: Re-insert for retransmission */
+		timeout = 10 * HZ;
+	} else {
+		/* Call was successful, now wait for client callback */
+		timeout = 60 * HZ;
+	}
+	nlmsvc_insert_block_locked(block, timeout);
+	svc_wake_up(block->b_daemon);
+out:
+	spin_unlock(&nlm_blocked_lock);
+}
+
+/*
+ * FIXME: nlmsvc_release_block() grabs a mutex.  This is not allowed for an
+ * .rpc_release rpc_call_op
+ */
+static void nlmsvc_grant_release(void *data)
+{
+	struct nlm_rqst		*call = data;
+	nlmsvc_release_block(call->a_block);
+}
+
+static const struct rpc_call_ops nlmsvc_grant_ops = {
+	.rpc_call_done = nlmsvc_grant_callback,
+	.rpc_release = nlmsvc_grant_release,
+};
+
+/*
+ * We received a GRANT_RES callback. Try to find the corresponding
+ * block.
+ */
+void
+nlmsvc_grant_reply(struct nlm_cookie *cookie, __be32 status)
+{
+	struct nlm_block	*block;
+	struct file_lock	*fl;
+	int			error;
+
+	dprintk("grant_reply: looking for cookie %x, s=%d \n",
+		*(unsigned int *)(cookie->data), status);
+	if (!(block = nlmsvc_find_block(cookie)))
+		return;
+
+	switch (status) {
+	case nlm_lck_denied_grace_period:
+		/* Try again in a couple of seconds */
+		nlmsvc_insert_block(block, 10 * HZ);
+		break;
+	case nlm_lck_denied:
+		/* Client doesn't want it, just unlock it */
+		nlmsvc_unlink_block(block);
+		fl = &block->b_call->a_args.lock.fl;
+		fl->fl_type = F_UNLCK;
+		error = vfs_lock_file(fl->fl_file, F_SETLK, fl, NULL);
+		if (error)
+			pr_warn("lockd: unable to unlock lock rejected by client!\n");
+		break;
+	default:
+		/*
+		 * Either it was accepted or the status makes no sense
+		 * just unlink it either way.
+		 */
+		nlmsvc_unlink_block(block);
+	}
+	nlmsvc_release_block(block);
+}
+
+/* Helper function to handle retry of a deferred block.
+ * If it is a blocking lock, call grant_blocked.
+ * For a non-blocking lock or test lock, revisit the request.
+ */
+static void
+retry_deferred_block(struct nlm_block *block)
+{
+	if (!(block->b_flags & B_GOT_CALLBACK))
+		block->b_flags |= B_TIMED_OUT;
+	nlmsvc_insert_block(block, NLM_TIMEOUT);
+	dprintk("revisit block %p flags %d\n",	block, block->b_flags);
+	if (block->b_deferred_req) {
+		block->b_deferred_req->revisit(block->b_deferred_req, 0);
+		block->b_deferred_req = NULL;
+	}
+}
+
+/*
+ * Retry all blocked locks that have been notified. This is where lockd
+ * picks up locks that can be granted, or grant notifications that must
+ * be retransmitted.
+ */
+void
+nlmsvc_retry_blocked(void)
+{
+	unsigned long	timeout = MAX_SCHEDULE_TIMEOUT;
+	struct nlm_block *block;
+
+	spin_lock(&nlm_blocked_lock);
+	while (!list_empty(&nlm_blocked) && !kthread_should_stop()) {
+		block = list_entry(nlm_blocked.next, struct nlm_block, b_list);
+
+		if (block->b_when == NLM_NEVER)
+			break;
+		if (time_after(block->b_when, jiffies)) {
+			timeout = block->b_when - jiffies;
+			break;
+		}
+		spin_unlock(&nlm_blocked_lock);
+
+		dprintk("nlmsvc_retry_blocked(%p, when=%ld)\n",
+			block, block->b_when);
+		if (block->b_flags & B_QUEUED) {
+			dprintk("nlmsvc_retry_blocked delete block (%p, granted=%d, flags=%d)\n",
+				block, block->b_granted, block->b_flags);
+			retry_deferred_block(block);
+		} else
+			nlmsvc_grant_blocked(block);
+		spin_lock(&nlm_blocked_lock);
+	}
+	spin_unlock(&nlm_blocked_lock);
+
+	if (timeout < MAX_SCHEDULE_TIMEOUT)
+		mod_timer(&nlmsvc_retry, jiffies + timeout);
+}
diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
new file mode 100644
index 0000000000..32784f508c
--- /dev/null
+++ b/fs/lockd/svcproc.c
@@ -0,0 +1,794 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/lockd/svcproc.c
+ *
+ * Lockd server procedures. We don't implement the NLM_*_RES 
+ * procedures because we don't use the async procedures.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/lockd/lockd.h>
+#include <linux/lockd/share.h>
+#include <linux/sunrpc/svc_xprt.h>
+
+#define NLMDBG_FACILITY		NLMDBG_CLIENT
+
+#ifdef CONFIG_LOCKD_V4
+static __be32
+cast_to_nlm(__be32 status, u32 vers)
+{
+	/* Note: status is assumed to be in network byte order !!! */
+	if (vers != 4){
+		switch (status) {
+		case nlm_granted:
+		case nlm_lck_denied:
+		case nlm_lck_denied_nolocks:
+		case nlm_lck_blocked:
+		case nlm_lck_denied_grace_period:
+		case nlm_drop_reply:
+			break;
+		case nlm4_deadlock:
+			status = nlm_lck_denied;
+			break;
+		default:
+			status = nlm_lck_denied_nolocks;
+		}
+	}
+
+	return (status);
+}
+#define	cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
+#else
+#define cast_status(status) (status)
+#endif
+
+/*
+ * Obtain client and file from arguments
+ */
+static __be32
+nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
+			struct nlm_host **hostp, struct nlm_file **filp)
+{
+	struct nlm_host		*host = NULL;
+	struct nlm_file		*file = NULL;
+	struct nlm_lock		*lock = &argp->lock;
+	int			mode;
+	__be32			error = 0;
+
+	/* nfsd callbacks must have been installed for this procedure */
+	if (!nlmsvc_ops)
+		return nlm_lck_denied_nolocks;
+
+	/* Obtain host handle */
+	if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
+	 || (argp->monitor && nsm_monitor(host) < 0))
+		goto no_locks;
+	*hostp = host;
+
+	/* Obtain file pointer. Not used by FREE_ALL call. */
+	if (filp != NULL) {
+		error = cast_status(nlm_lookup_file(rqstp, &file, lock));
+		if (error != 0)
+			goto no_locks;
+		*filp = file;
+
+		/* Set up the missing parts of the file_lock structure */
+		mode = lock_to_openmode(&lock->fl);
+		lock->fl.fl_flags = FL_POSIX;
+		lock->fl.fl_file  = file->f_file[mode];
+		lock->fl.fl_pid = current->tgid;
+		lock->fl.fl_lmops = &nlmsvc_lock_operations;
+		nlmsvc_locks_init_private(&lock->fl, host, (pid_t)lock->svid);
+		if (!lock->fl.fl_owner) {
+			/* lockowner allocation has failed */
+			nlmsvc_release_host(host);
+			return nlm_lck_denied_nolocks;
+		}
+	}
+
+	return 0;
+
+no_locks:
+	nlmsvc_release_host(host);
+	if (error)
+		return error;
+	return nlm_lck_denied_nolocks;
+}
+
+/*
+ * NULL: Test for presence of service
+ */
+static __be32
+nlmsvc_proc_null(struct svc_rqst *rqstp)
+{
+	dprintk("lockd: NULL          called\n");
+	return rpc_success;
+}
+
+/*
+ * TEST: Check for conflicting lock
+ */
+static __be32
+__nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_res *resp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_host	*host;
+	struct nlm_file	*file;
+	struct nlm_lockowner *test_owner;
+	__be32 rc = rpc_success;
+
+	dprintk("lockd: TEST          called\n");
+	resp->cookie = argp->cookie;
+
+	/* Obtain client and file */
+	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
+		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
+
+	test_owner = argp->lock.fl.fl_owner;
+
+	/* Now check for conflicting locks */
+	resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
+	if (resp->status == nlm_drop_reply)
+		rc = rpc_drop_reply;
+	else
+		dprintk("lockd: TEST          status %d vers %d\n",
+			ntohl(resp->status), rqstp->rq_vers);
+
+	nlmsvc_put_lockowner(test_owner);
+	nlmsvc_release_host(host);
+	nlm_release_file(file);
+	return rc;
+}
+
+static __be32
+nlmsvc_proc_test(struct svc_rqst *rqstp)
+{
+	return __nlmsvc_proc_test(rqstp, rqstp->rq_resp);
+}
+
+static __be32
+__nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_res *resp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_host	*host;
+	struct nlm_file	*file;
+	__be32 rc = rpc_success;
+
+	dprintk("lockd: LOCK          called\n");
+
+	resp->cookie = argp->cookie;
+
+	/* Obtain client and file */
+	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
+		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
+
+#if 0
+	/* If supplied state doesn't match current state, we assume it's
+	 * an old request that time-warped somehow. Any error return would
+	 * do in this case because it's irrelevant anyway.
+	 *
+	 * NB: We don't retrieve the remote host's state yet.
+	 */
+	if (host->h_nsmstate && host->h_nsmstate != argp->state) {
+		resp->status = nlm_lck_denied_nolocks;
+	} else
+#endif
+
+	/* Now try to lock the file */
+	resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
+					       argp->block, &argp->cookie,
+					       argp->reclaim));
+	if (resp->status == nlm_drop_reply)
+		rc = rpc_drop_reply;
+	else
+		dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
+
+	nlmsvc_release_lockowner(&argp->lock);
+	nlmsvc_release_host(host);
+	nlm_release_file(file);
+	return rc;
+}
+
+static __be32
+nlmsvc_proc_lock(struct svc_rqst *rqstp)
+{
+	return __nlmsvc_proc_lock(rqstp, rqstp->rq_resp);
+}
+
+static __be32
+__nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_res *resp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_host	*host;
+	struct nlm_file	*file;
+	struct net *net = SVC_NET(rqstp);
+
+	dprintk("lockd: CANCEL        called\n");
+
+	resp->cookie = argp->cookie;
+
+	/* Don't accept requests during grace period */
+	if (locks_in_grace(net)) {
+		resp->status = nlm_lck_denied_grace_period;
+		return rpc_success;
+	}
+
+	/* Obtain client and file */
+	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
+		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
+
+	/* Try to cancel request. */
+	resp->status = cast_status(nlmsvc_cancel_blocked(net, file, &argp->lock));
+
+	dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
+	nlmsvc_release_lockowner(&argp->lock);
+	nlmsvc_release_host(host);
+	nlm_release_file(file);
+	return rpc_success;
+}
+
+static __be32
+nlmsvc_proc_cancel(struct svc_rqst *rqstp)
+{
+	return __nlmsvc_proc_cancel(rqstp, rqstp->rq_resp);
+}
+
+/*
+ * UNLOCK: release a lock
+ */
+static __be32
+__nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_res *resp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_host	*host;
+	struct nlm_file	*file;
+	struct net *net = SVC_NET(rqstp);
+
+	dprintk("lockd: UNLOCK        called\n");
+
+	resp->cookie = argp->cookie;
+
+	/* Don't accept new lock requests during grace period */
+	if (locks_in_grace(net)) {
+		resp->status = nlm_lck_denied_grace_period;
+		return rpc_success;
+	}
+
+	/* Obtain client and file */
+	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
+		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
+
+	/* Now try to remove the lock */
+	resp->status = cast_status(nlmsvc_unlock(net, file, &argp->lock));
+
+	dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
+	nlmsvc_release_lockowner(&argp->lock);
+	nlmsvc_release_host(host);
+	nlm_release_file(file);
+	return rpc_success;
+}
+
+static __be32
+nlmsvc_proc_unlock(struct svc_rqst *rqstp)
+{
+	return __nlmsvc_proc_unlock(rqstp, rqstp->rq_resp);
+}
+
+/*
+ * GRANTED: A server calls us to tell that a process' lock request
+ * was granted
+ */
+static __be32
+__nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_res *resp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+
+	resp->cookie = argp->cookie;
+
+	dprintk("lockd: GRANTED       called\n");
+	resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
+	dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
+	return rpc_success;
+}
+
+static __be32
+nlmsvc_proc_granted(struct svc_rqst *rqstp)
+{
+	return __nlmsvc_proc_granted(rqstp, rqstp->rq_resp);
+}
+
+/*
+ * This is the generic lockd callback for async RPC calls
+ */
+static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
+{
+}
+
+void nlmsvc_release_call(struct nlm_rqst *call)
+{
+	if (!refcount_dec_and_test(&call->a_count))
+		return;
+	nlmsvc_release_host(call->a_host);
+	kfree(call);
+}
+
+static void nlmsvc_callback_release(void *data)
+{
+	nlmsvc_release_call(data);
+}
+
+static const struct rpc_call_ops nlmsvc_callback_ops = {
+	.rpc_call_done = nlmsvc_callback_exit,
+	.rpc_release = nlmsvc_callback_release,
+};
+
+/*
+ * `Async' versions of the above service routines. They aren't really,
+ * because we send the callback before the reply proper. I hope this
+ * doesn't break any clients.
+ */
+static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc,
+		__be32 (*func)(struct svc_rqst *, struct nlm_res *))
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_host	*host;
+	struct nlm_rqst	*call;
+	__be32 stat;
+
+	host = nlmsvc_lookup_host(rqstp,
+				  argp->lock.caller,
+				  argp->lock.len);
+	if (host == NULL)
+		return rpc_system_err;
+
+	call = nlm_alloc_call(host);
+	nlmsvc_release_host(host);
+	if (call == NULL)
+		return rpc_system_err;
+
+	stat = func(rqstp, &call->a_res);
+	if (stat != 0) {
+		nlmsvc_release_call(call);
+		return stat;
+	}
+
+	call->a_flags = RPC_TASK_ASYNC;
+	if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
+		return rpc_system_err;
+	return rpc_success;
+}
+
+static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp)
+{
+	dprintk("lockd: TEST_MSG      called\n");
+	return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, __nlmsvc_proc_test);
+}
+
+static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp)
+{
+	dprintk("lockd: LOCK_MSG      called\n");
+	return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, __nlmsvc_proc_lock);
+}
+
+static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp)
+{
+	dprintk("lockd: CANCEL_MSG    called\n");
+	return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, __nlmsvc_proc_cancel);
+}
+
+static __be32
+nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp)
+{
+	dprintk("lockd: UNLOCK_MSG    called\n");
+	return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, __nlmsvc_proc_unlock);
+}
+
+static __be32
+nlmsvc_proc_granted_msg(struct svc_rqst *rqstp)
+{
+	dprintk("lockd: GRANTED_MSG   called\n");
+	return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, __nlmsvc_proc_granted);
+}
+
+/*
+ * SHARE: create a DOS share or alter existing share.
+ */
+static __be32
+nlmsvc_proc_share(struct svc_rqst *rqstp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_res *resp = rqstp->rq_resp;
+	struct nlm_host	*host;
+	struct nlm_file	*file;
+
+	dprintk("lockd: SHARE         called\n");
+
+	resp->cookie = argp->cookie;
+
+	/* Don't accept new lock requests during grace period */
+	if (locks_in_grace(SVC_NET(rqstp)) && !argp->reclaim) {
+		resp->status = nlm_lck_denied_grace_period;
+		return rpc_success;
+	}
+
+	/* Obtain client and file */
+	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
+		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
+
+	/* Now try to create the share */
+	resp->status = cast_status(nlmsvc_share_file(host, file, argp));
+
+	dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
+	nlmsvc_release_lockowner(&argp->lock);
+	nlmsvc_release_host(host);
+	nlm_release_file(file);
+	return rpc_success;
+}
+
+/*
+ * UNSHARE: Release a DOS share.
+ */
+static __be32
+nlmsvc_proc_unshare(struct svc_rqst *rqstp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_res *resp = rqstp->rq_resp;
+	struct nlm_host	*host;
+	struct nlm_file	*file;
+
+	dprintk("lockd: UNSHARE       called\n");
+
+	resp->cookie = argp->cookie;
+
+	/* Don't accept requests during grace period */
+	if (locks_in_grace(SVC_NET(rqstp))) {
+		resp->status = nlm_lck_denied_grace_period;
+		return rpc_success;
+	}
+
+	/* Obtain client and file */
+	if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
+		return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
+
+	/* Now try to unshare the file */
+	resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
+
+	dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
+	nlmsvc_release_lockowner(&argp->lock);
+	nlmsvc_release_host(host);
+	nlm_release_file(file);
+	return rpc_success;
+}
+
+/*
+ * NM_LOCK: Create an unmonitored lock
+ */
+static __be32
+nlmsvc_proc_nm_lock(struct svc_rqst *rqstp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+
+	dprintk("lockd: NM_LOCK       called\n");
+
+	argp->monitor = 0;		/* just clean the monitor flag */
+	return nlmsvc_proc_lock(rqstp);
+}
+
+/*
+ * FREE_ALL: Release all locks and shares held by client
+ */
+static __be32
+nlmsvc_proc_free_all(struct svc_rqst *rqstp)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_host	*host;
+
+	/* Obtain client */
+	if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
+		return rpc_success;
+
+	nlmsvc_free_host_resources(host);
+	nlmsvc_release_host(host);
+	return rpc_success;
+}
+
+/*
+ * SM_NOTIFY: private callback from statd (not part of official NLM proto)
+ */
+static __be32
+nlmsvc_proc_sm_notify(struct svc_rqst *rqstp)
+{
+	struct nlm_reboot *argp = rqstp->rq_argp;
+
+	dprintk("lockd: SM_NOTIFY     called\n");
+
+	if (!nlm_privileged_requester(rqstp)) {
+		char buf[RPC_MAX_ADDRBUFLEN];
+		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
+				svc_print_addr(rqstp, buf, sizeof(buf)));
+		return rpc_system_err;
+	}
+
+	nlm_host_rebooted(SVC_NET(rqstp), argp);
+	return rpc_success;
+}
+
+/*
+ * client sent a GRANTED_RES, let's remove the associated block
+ */
+static __be32
+nlmsvc_proc_granted_res(struct svc_rqst *rqstp)
+{
+	struct nlm_res *argp = rqstp->rq_argp;
+
+	if (!nlmsvc_ops)
+		return rpc_success;
+
+	dprintk("lockd: GRANTED_RES   called\n");
+
+	nlmsvc_grant_reply(&argp->cookie, argp->status);
+	return rpc_success;
+}
+
+static __be32
+nlmsvc_proc_unused(struct svc_rqst *rqstp)
+{
+	return rpc_proc_unavail;
+}
+
+/*
+ * NLM Server procedures.
+ */
+
+struct nlm_void			{ int dummy; };
+
+#define	Ck	(1+XDR_QUADLEN(NLM_MAXCOOKIELEN))	/* cookie */
+#define	St	1				/* status */
+#define	No	(1+1024/4)			/* Net Obj */
+#define	Rg	2				/* range - offset + size */
+
+const struct svc_procedure nlmsvc_procedures[24] = {
+	[NLMPROC_NULL] = {
+		.pc_func = nlmsvc_proc_null,
+		.pc_decode = nlmsvc_decode_void,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_void),
+		.pc_argzero = sizeof(struct nlm_void),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "NULL",
+	},
+	[NLMPROC_TEST] = {
+		.pc_func = nlmsvc_proc_test,
+		.pc_decode = nlmsvc_decode_testargs,
+		.pc_encode = nlmsvc_encode_testres,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St+2+No+Rg,
+		.pc_name = "TEST",
+	},
+	[NLMPROC_LOCK] = {
+		.pc_func = nlmsvc_proc_lock,
+		.pc_decode = nlmsvc_decode_lockargs,
+		.pc_encode = nlmsvc_encode_res,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St,
+		.pc_name = "LOCK",
+	},
+	[NLMPROC_CANCEL] = {
+		.pc_func = nlmsvc_proc_cancel,
+		.pc_decode = nlmsvc_decode_cancargs,
+		.pc_encode = nlmsvc_encode_res,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St,
+		.pc_name = "CANCEL",
+	},
+	[NLMPROC_UNLOCK] = {
+		.pc_func = nlmsvc_proc_unlock,
+		.pc_decode = nlmsvc_decode_unlockargs,
+		.pc_encode = nlmsvc_encode_res,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St,
+		.pc_name = "UNLOCK",
+	},
+	[NLMPROC_GRANTED] = {
+		.pc_func = nlmsvc_proc_granted,
+		.pc_decode = nlmsvc_decode_testargs,
+		.pc_encode = nlmsvc_encode_res,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St,
+		.pc_name = "GRANTED",
+	},
+	[NLMPROC_TEST_MSG] = {
+		.pc_func = nlmsvc_proc_test_msg,
+		.pc_decode = nlmsvc_decode_testargs,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "TEST_MSG",
+	},
+	[NLMPROC_LOCK_MSG] = {
+		.pc_func = nlmsvc_proc_lock_msg,
+		.pc_decode = nlmsvc_decode_lockargs,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "LOCK_MSG",
+	},
+	[NLMPROC_CANCEL_MSG] = {
+		.pc_func = nlmsvc_proc_cancel_msg,
+		.pc_decode = nlmsvc_decode_cancargs,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "CANCEL_MSG",
+	},
+	[NLMPROC_UNLOCK_MSG] = {
+		.pc_func = nlmsvc_proc_unlock_msg,
+		.pc_decode = nlmsvc_decode_unlockargs,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "UNLOCK_MSG",
+	},
+	[NLMPROC_GRANTED_MSG] = {
+		.pc_func = nlmsvc_proc_granted_msg,
+		.pc_decode = nlmsvc_decode_testargs,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "GRANTED_MSG",
+	},
+	[NLMPROC_TEST_RES] = {
+		.pc_func = nlmsvc_proc_null,
+		.pc_decode = nlmsvc_decode_void,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_res),
+		.pc_argzero = sizeof(struct nlm_res),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "TEST_RES",
+	},
+	[NLMPROC_LOCK_RES] = {
+		.pc_func = nlmsvc_proc_null,
+		.pc_decode = nlmsvc_decode_void,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_res),
+		.pc_argzero = sizeof(struct nlm_res),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "LOCK_RES",
+	},
+	[NLMPROC_CANCEL_RES] = {
+		.pc_func = nlmsvc_proc_null,
+		.pc_decode = nlmsvc_decode_void,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_res),
+		.pc_argzero = sizeof(struct nlm_res),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "CANCEL_RES",
+	},
+	[NLMPROC_UNLOCK_RES] = {
+		.pc_func = nlmsvc_proc_null,
+		.pc_decode = nlmsvc_decode_void,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_res),
+		.pc_argzero = sizeof(struct nlm_res),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "UNLOCK_RES",
+	},
+	[NLMPROC_GRANTED_RES] = {
+		.pc_func = nlmsvc_proc_granted_res,
+		.pc_decode = nlmsvc_decode_res,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_res),
+		.pc_argzero = sizeof(struct nlm_res),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "GRANTED_RES",
+	},
+	[NLMPROC_NSM_NOTIFY] = {
+		.pc_func = nlmsvc_proc_sm_notify,
+		.pc_decode = nlmsvc_decode_reboot,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_reboot),
+		.pc_argzero = sizeof(struct nlm_reboot),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "SM_NOTIFY",
+	},
+	[17] = {
+		.pc_func = nlmsvc_proc_unused,
+		.pc_decode = nlmsvc_decode_void,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_void),
+		.pc_argzero = sizeof(struct nlm_void),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "UNUSED",
+	},
+	[18] = {
+		.pc_func = nlmsvc_proc_unused,
+		.pc_decode = nlmsvc_decode_void,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_void),
+		.pc_argzero = sizeof(struct nlm_void),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "UNUSED",
+	},
+	[19] = {
+		.pc_func = nlmsvc_proc_unused,
+		.pc_decode = nlmsvc_decode_void,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_void),
+		.pc_argzero = sizeof(struct nlm_void),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = St,
+		.pc_name = "UNUSED",
+	},
+	[NLMPROC_SHARE] = {
+		.pc_func = nlmsvc_proc_share,
+		.pc_decode = nlmsvc_decode_shareargs,
+		.pc_encode = nlmsvc_encode_shareres,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St+1,
+		.pc_name = "SHARE",
+	},
+	[NLMPROC_UNSHARE] = {
+		.pc_func = nlmsvc_proc_unshare,
+		.pc_decode = nlmsvc_decode_shareargs,
+		.pc_encode = nlmsvc_encode_shareres,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St+1,
+		.pc_name = "UNSHARE",
+	},
+	[NLMPROC_NM_LOCK] = {
+		.pc_func = nlmsvc_proc_nm_lock,
+		.pc_decode = nlmsvc_decode_lockargs,
+		.pc_encode = nlmsvc_encode_res,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_res),
+		.pc_xdrressize = Ck+St,
+		.pc_name = "NM_LOCK",
+	},
+	[NLMPROC_FREE_ALL] = {
+		.pc_func = nlmsvc_proc_free_all,
+		.pc_decode = nlmsvc_decode_notify,
+		.pc_encode = nlmsvc_encode_void,
+		.pc_argsize = sizeof(struct nlm_args),
+		.pc_argzero = sizeof(struct nlm_args),
+		.pc_ressize = sizeof(struct nlm_void),
+		.pc_xdrressize = 0,
+		.pc_name = "FREE_ALL",
+	},
+};
diff --git a/fs/lockd/svcshare.c b/fs/lockd/svcshare.c
new file mode 100644
index 0000000000..ade4931b2d
--- /dev/null
+++ b/fs/lockd/svcshare.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/lockd/svcshare.c
+ *
+ * Management of DOS shares.
+ *
+ * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/time.h>
+#include <linux/unistd.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/lockd/lockd.h>
+#include <linux/lockd/share.h>
+
+static inline int
+nlm_cmp_owner(struct nlm_share *share, struct xdr_netobj *oh)
+{
+	return share->s_owner.len == oh->len
+	    && !memcmp(share->s_owner.data, oh->data, oh->len);
+}
+
+__be32
+nlmsvc_share_file(struct nlm_host *host, struct nlm_file *file,
+			struct nlm_args *argp)
+{
+	struct nlm_share	*share;
+	struct xdr_netobj	*oh = &argp->lock.oh;
+	u8			*ohdata;
+
+	for (share = file->f_shares; share; share = share->s_next) {
+		if (share->s_host == host && nlm_cmp_owner(share, oh))
+			goto update;
+		if ((argp->fsm_access & share->s_mode)
+		 || (argp->fsm_mode   & share->s_access ))
+			return nlm_lck_denied;
+	}
+
+	share = kmalloc(sizeof(*share) + oh->len,
+						GFP_KERNEL);
+	if (share == NULL)
+		return nlm_lck_denied_nolocks;
+
+	/* Copy owner handle */
+	ohdata = (u8 *) (share + 1);
+	memcpy(ohdata, oh->data, oh->len);
+
+	share->s_file	    = file;
+	share->s_host       = host;
+	share->s_owner.data = ohdata;
+	share->s_owner.len  = oh->len;
+	share->s_next       = file->f_shares;
+	file->f_shares      = share;
+
+update:
+	share->s_access = argp->fsm_access;
+	share->s_mode   = argp->fsm_mode;
+	return nlm_granted;
+}
+
+/*
+ * Delete a share.
+ */
+__be32
+nlmsvc_unshare_file(struct nlm_host *host, struct nlm_file *file,
+			struct nlm_args *argp)
+{
+	struct nlm_share	*share, **shpp;
+	struct xdr_netobj	*oh = &argp->lock.oh;
+
+	for (shpp = &file->f_shares; (share = *shpp) != NULL;
+					shpp = &share->s_next) {
+		if (share->s_host == host && nlm_cmp_owner(share, oh)) {
+			*shpp = share->s_next;
+			kfree(share);
+			return nlm_granted;
+		}
+	}
+
+	/* X/Open spec says return success even if there was no
+	 * corresponding share. */
+	return nlm_granted;
+}
+
+/*
+ * Traverse all shares for a given file, and delete
+ * those owned by the given (type of) host
+ */
+void nlmsvc_traverse_shares(struct nlm_host *host, struct nlm_file *file,
+		nlm_host_match_fn_t match)
+{
+	struct nlm_share	*share, **shpp;
+
+	shpp = &file->f_shares;
+	while ((share = *shpp) !=  NULL) {
+		if (match(share->s_host, host)) {
+			*shpp = share->s_next;
+			kfree(share);
+			continue;
+		}
+		shpp = &share->s_next;
+	}
+}
diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c
new file mode 100644
index 0000000000..e3b6229e7a
--- /dev/null
+++ b/fs/lockd/svcsubs.c
@@ -0,0 +1,505 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/fs/lockd/svcsubs.c
+ *
+ * Various support routines for the NLM server.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/time.h>
+#include <linux/in.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/lockd/lockd.h>
+#include <linux/lockd/share.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <uapi/linux/nfs2.h>
+
+#define NLMDBG_FACILITY		NLMDBG_SVCSUBS
+
+
+/*
+ * Global file hash table
+ */
+#define FILE_HASH_BITS		7
+#define FILE_NRHASH		(1<<FILE_HASH_BITS)
+static struct hlist_head	nlm_files[FILE_NRHASH];
+static DEFINE_MUTEX(nlm_file_mutex);
+
+#ifdef CONFIG_SUNRPC_DEBUG
+static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
+{
+	u32 *fhp = (u32*)f->data;
+
+	/* print the first 32 bytes of the fh */
+	dprintk("lockd: %s (%08x %08x %08x %08x %08x %08x %08x %08x)\n",
+		msg, fhp[0], fhp[1], fhp[2], fhp[3],
+		fhp[4], fhp[5], fhp[6], fhp[7]);
+}
+
+static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
+{
+	struct inode *inode = nlmsvc_file_inode(file);
+
+	dprintk("lockd: %s %s/%ld\n",
+		msg, inode->i_sb->s_id, inode->i_ino);
+}
+#else
+static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
+{
+	return;
+}
+
+static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
+{
+	return;
+}
+#endif
+
+static inline unsigned int file_hash(struct nfs_fh *f)
+{
+	unsigned int tmp=0;
+	int i;
+	for (i=0; i<NFS2_FHSIZE;i++)
+		tmp += f->data[i];
+	return tmp & (FILE_NRHASH - 1);
+}
+
+int lock_to_openmode(struct file_lock *lock)
+{
+	return (lock->fl_type == F_WRLCK) ? O_WRONLY : O_RDONLY;
+}
+
+/*
+ * Open the file. Note that if we're reexporting, for example,
+ * this could block the lockd thread for a while.
+ *
+ * We have to make sure we have the right credential to open
+ * the file.
+ */
+static __be32 nlm_do_fopen(struct svc_rqst *rqstp,
+			   struct nlm_file *file, int mode)
+{
+	struct file **fp = &file->f_file[mode];
+	__be32	nfserr;
+
+	if (*fp)
+		return 0;
+	nfserr = nlmsvc_ops->fopen(rqstp, &file->f_handle, fp, mode);
+	if (nfserr)
+		dprintk("lockd: open failed (error %d)\n", nfserr);
+	return nfserr;
+}
+
+/*
+ * Lookup file info. If it doesn't exist, create a file info struct
+ * and open a (VFS) file for the given inode.
+ */
+__be32
+nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
+					struct nlm_lock *lock)
+{
+	struct nlm_file	*file;
+	unsigned int	hash;
+	__be32		nfserr;
+	int		mode;
+
+	nlm_debug_print_fh("nlm_lookup_file", &lock->fh);
+
+	hash = file_hash(&lock->fh);
+	mode = lock_to_openmode(&lock->fl);
+
+	/* Lock file table */
+	mutex_lock(&nlm_file_mutex);
+
+	hlist_for_each_entry(file, &nlm_files[hash], f_list)
+		if (!nfs_compare_fh(&file->f_handle, &lock->fh)) {
+			mutex_lock(&file->f_mutex);
+			nfserr = nlm_do_fopen(rqstp, file, mode);
+			mutex_unlock(&file->f_mutex);
+			goto found;
+		}
+	nlm_debug_print_fh("creating file for", &lock->fh);
+
+	nfserr = nlm_lck_denied_nolocks;
+	file = kzalloc(sizeof(*file), GFP_KERNEL);
+	if (!file)
+		goto out_free;
+
+	memcpy(&file->f_handle, &lock->fh, sizeof(struct nfs_fh));
+	mutex_init(&file->f_mutex);
+	INIT_HLIST_NODE(&file->f_list);
+	INIT_LIST_HEAD(&file->f_blocks);
+
+	nfserr = nlm_do_fopen(rqstp, file, mode);
+	if (nfserr)
+		goto out_unlock;
+
+	hlist_add_head(&file->f_list, &nlm_files[hash]);
+
+found:
+	dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
+	*result = file;
+	file->f_count++;
+
+out_unlock:
+	mutex_unlock(&nlm_file_mutex);
+	return nfserr;
+
+out_free:
+	kfree(file);
+	goto out_unlock;
+}
+
+/*
+ * Delete a file after having released all locks, blocks and shares
+ */
+static inline void
+nlm_delete_file(struct nlm_file *file)
+{
+	nlm_debug_print_file("closing file", file);
+	if (!hlist_unhashed(&file->f_list)) {
+		hlist_del(&file->f_list);
+		if (file->f_file[O_RDONLY])
+			nlmsvc_ops->fclose(file->f_file[O_RDONLY]);
+		if (file->f_file[O_WRONLY])
+			nlmsvc_ops->fclose(file->f_file[O_WRONLY]);
+		kfree(file);
+	} else {
+		printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
+	}
+}
+
+static int nlm_unlock_files(struct nlm_file *file, const struct file_lock *fl)
+{
+	struct file_lock lock;
+
+	locks_init_lock(&lock);
+	lock.fl_type  = F_UNLCK;
+	lock.fl_start = 0;
+	lock.fl_end   = OFFSET_MAX;
+	lock.fl_owner = fl->fl_owner;
+	lock.fl_pid   = fl->fl_pid;
+	lock.fl_flags = FL_POSIX;
+
+	lock.fl_file = file->f_file[O_RDONLY];
+	if (lock.fl_file && vfs_lock_file(lock.fl_file, F_SETLK, &lock, NULL))
+		goto out_err;
+	lock.fl_file = file->f_file[O_WRONLY];
+	if (lock.fl_file && vfs_lock_file(lock.fl_file, F_SETLK, &lock, NULL))
+		goto out_err;
+	return 0;
+out_err:
+	pr_warn("lockd: unlock failure in %s:%d\n", __FILE__, __LINE__);
+	return 1;
+}
+
+/*
+ * Loop over all locks on the given file and perform the specified
+ * action.
+ */
+static int
+nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
+			nlm_host_match_fn_t match)
+{
+	struct inode	 *inode = nlmsvc_file_inode(file);
+	struct file_lock *fl;
+	struct file_lock_context *flctx = locks_inode_context(inode);
+	struct nlm_host	 *lockhost;
+
+	if (!flctx || list_empty_careful(&flctx->flc_posix))
+		return 0;
+again:
+	file->f_locks = 0;
+	spin_lock(&flctx->flc_lock);
+	list_for_each_entry(fl, &flctx->flc_posix, fl_list) {
+		if (fl->fl_lmops != &nlmsvc_lock_operations)
+			continue;
+
+		/* update current lock count */
+		file->f_locks++;
+
+		lockhost = ((struct nlm_lockowner *)fl->fl_owner)->host;
+		if (match(lockhost, host)) {
+
+			spin_unlock(&flctx->flc_lock);
+			if (nlm_unlock_files(file, fl))
+				return 1;
+			goto again;
+		}
+	}
+	spin_unlock(&flctx->flc_lock);
+
+	return 0;
+}
+
+static int
+nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2)
+{
+	return 1;
+}
+
+/*
+ * Inspect a single file
+ */
+static inline int
+nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, nlm_host_match_fn_t match)
+{
+	nlmsvc_traverse_blocks(host, file, match);
+	nlmsvc_traverse_shares(host, file, match);
+	return nlm_traverse_locks(host, file, match);
+}
+
+/*
+ * Quick check whether there are still any locks, blocks or
+ * shares on a given file.
+ */
+static inline int
+nlm_file_inuse(struct nlm_file *file)
+{
+	struct inode	 *inode = nlmsvc_file_inode(file);
+	struct file_lock *fl;
+	struct file_lock_context *flctx = locks_inode_context(inode);
+
+	if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares)
+		return 1;
+
+	if (flctx && !list_empty_careful(&flctx->flc_posix)) {
+		spin_lock(&flctx->flc_lock);
+		list_for_each_entry(fl, &flctx->flc_posix, fl_list) {
+			if (fl->fl_lmops == &nlmsvc_lock_operations) {
+				spin_unlock(&flctx->flc_lock);
+				return 1;
+			}
+		}
+		spin_unlock(&flctx->flc_lock);
+	}
+	file->f_locks = 0;
+	return 0;
+}
+
+static void nlm_close_files(struct nlm_file *file)
+{
+	if (file->f_file[O_RDONLY])
+		nlmsvc_ops->fclose(file->f_file[O_RDONLY]);
+	if (file->f_file[O_WRONLY])
+		nlmsvc_ops->fclose(file->f_file[O_WRONLY]);
+}
+
+/*
+ * Loop over all files in the file table.
+ */
+static int
+nlm_traverse_files(void *data, nlm_host_match_fn_t match,
+		int (*is_failover_file)(void *data, struct nlm_file *file))
+{
+	struct hlist_node *next;
+	struct nlm_file	*file;
+	int i, ret = 0;
+
+	mutex_lock(&nlm_file_mutex);
+	for (i = 0; i < FILE_NRHASH; i++) {
+		hlist_for_each_entry_safe(file, next, &nlm_files[i], f_list) {
+			if (is_failover_file && !is_failover_file(data, file))
+				continue;
+			file->f_count++;
+			mutex_unlock(&nlm_file_mutex);
+
+			/* Traverse locks, blocks and shares of this file
+			 * and update file->f_locks count */
+			if (nlm_inspect_file(data, file, match))
+				ret = 1;
+
+			mutex_lock(&nlm_file_mutex);
+			file->f_count--;
+			/* No more references to this file. Let go of it. */
+			if (list_empty(&file->f_blocks) && !file->f_locks
+			 && !file->f_shares && !file->f_count) {
+				hlist_del(&file->f_list);
+				nlm_close_files(file);
+				kfree(file);
+			}
+		}
+	}
+	mutex_unlock(&nlm_file_mutex);
+	return ret;
+}
+
+/*
+ * Release file. If there are no more remote locks on this file,
+ * close it and free the handle.
+ *
+ * Note that we can't do proper reference counting without major
+ * contortions because the code in fs/locks.c creates, deletes and
+ * splits locks without notification. Our only way is to walk the
+ * entire lock list each time we remove a lock.
+ */
+void
+nlm_release_file(struct nlm_file *file)
+{
+	dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
+				file, file->f_count);
+
+	/* Lock file table */
+	mutex_lock(&nlm_file_mutex);
+
+	/* If there are no more locks etc, delete the file */
+	if (--file->f_count == 0 && !nlm_file_inuse(file))
+		nlm_delete_file(file);
+
+	mutex_unlock(&nlm_file_mutex);
+}
+
+/*
+ * Helpers function for resource traversal
+ *
+ * nlmsvc_mark_host:
+ *	used by the garbage collector; simply sets h_inuse only for those
+ *	hosts, which passed network check.
+ *	Always returns 0.
+ *
+ * nlmsvc_same_host:
+ *	returns 1 iff the two hosts match. Used to release
+ *	all resources bound to a specific host.
+ *
+ * nlmsvc_is_client:
+ *	returns 1 iff the host is a client.
+ *	Used by nlmsvc_invalidate_all
+ */
+
+static int
+nlmsvc_mark_host(void *data, struct nlm_host *hint)
+{
+	struct nlm_host *host = data;
+
+	if ((hint->net == NULL) ||
+	    (host->net == hint->net))
+		host->h_inuse = 1;
+	return 0;
+}
+
+static int
+nlmsvc_same_host(void *data, struct nlm_host *other)
+{
+	struct nlm_host *host = data;
+
+	return host == other;
+}
+
+static int
+nlmsvc_is_client(void *data, struct nlm_host *dummy)
+{
+	struct nlm_host *host = data;
+
+	if (host->h_server) {
+		/* we are destroying locks even though the client
+		 * hasn't asked us too, so don't unmonitor the
+		 * client
+		 */
+		if (host->h_nsmhandle)
+			host->h_nsmhandle->sm_sticky = 1;
+		return 1;
+	} else
+		return 0;
+}
+
+/*
+ * Mark all hosts that still hold resources
+ */
+void
+nlmsvc_mark_resources(struct net *net)
+{
+	struct nlm_host hint;
+
+	dprintk("lockd: %s for net %x\n", __func__, net ? net->ns.inum : 0);
+	hint.net = net;
+	nlm_traverse_files(&hint, nlmsvc_mark_host, NULL);
+}
+
+/*
+ * Release all resources held by the given client
+ */
+void
+nlmsvc_free_host_resources(struct nlm_host *host)
+{
+	dprintk("lockd: nlmsvc_free_host_resources\n");
+
+	if (nlm_traverse_files(host, nlmsvc_same_host, NULL)) {
+		printk(KERN_WARNING
+			"lockd: couldn't remove all locks held by %s\n",
+			host->h_name);
+		BUG();
+	}
+}
+
+/**
+ * nlmsvc_invalidate_all - remove all locks held for clients
+ *
+ * Release all locks held by NFS clients.
+ *
+ */
+void
+nlmsvc_invalidate_all(void)
+{
+	/*
+	 * Previously, the code would call
+	 * nlmsvc_free_host_resources for each client in
+	 * turn, which is about as inefficient as it gets.
+	 * Now we just do it once in nlm_traverse_files.
+	 */
+	nlm_traverse_files(NULL, nlmsvc_is_client, NULL);
+}
+
+
+static int
+nlmsvc_match_sb(void *datap, struct nlm_file *file)
+{
+	struct super_block *sb = datap;
+
+	return sb == nlmsvc_file_inode(file)->i_sb;
+}
+
+/**
+ * nlmsvc_unlock_all_by_sb - release locks held on this file system
+ * @sb: super block
+ *
+ * Release all locks held by clients accessing this file system.
+ */
+int
+nlmsvc_unlock_all_by_sb(struct super_block *sb)
+{
+	int ret;
+
+	ret = nlm_traverse_files(sb, nlmsvc_always_match, nlmsvc_match_sb);
+	return ret ? -EIO : 0;
+}
+EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb);
+
+static int
+nlmsvc_match_ip(void *datap, struct nlm_host *host)
+{
+	return rpc_cmp_addr(nlm_srcaddr(host), datap);
+}
+
+/**
+ * nlmsvc_unlock_all_by_ip - release local locks by IP address
+ * @server_addr: server's IP address as seen by clients
+ *
+ * Release all locks held by clients accessing this host
+ * via the passed in IP address.
+ */
+int
+nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr)
+{
+	int ret;
+
+	ret = nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
+	return ret ? -EIO : 0;
+}
+EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_ip);
diff --git a/fs/lockd/svcxdr.h b/fs/lockd/svcxdr.h
new file mode 100644
index 0000000000..4f1a451da5
--- /dev/null
+++ b/fs/lockd/svcxdr.h
@@ -0,0 +1,142 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Encode/decode NLM basic data types
+ *
+ * Basic NLMv3 XDR data types are not defined in an IETF standards
+ * document.  X/Open has a description of these data types that
+ * is useful.  See Chapter 10 of "Protocols for Interworking:
+ * XNFS, Version 3W".
+ *
+ * Basic NLMv4 XDR data types are defined in Appendix II.1.4 of
+ * RFC 1813: "NFS Version 3 Protocol Specification".
+ *
+ * Author: Chuck Lever <chuck.lever@oracle.com>
+ *
+ * Copyright (c) 2020, Oracle and/or its affiliates.
+ */
+
+#ifndef _LOCKD_SVCXDR_H_
+#define _LOCKD_SVCXDR_H_
+
+static inline bool
+svcxdr_decode_stats(struct xdr_stream *xdr, __be32 *status)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, XDR_UNIT);
+	if (!p)
+		return false;
+	*status = *p;
+
+	return true;
+}
+
+static inline bool
+svcxdr_encode_stats(struct xdr_stream *xdr, __be32 status)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT);
+	if (!p)
+		return false;
+	*p = status;
+
+	return true;
+}
+
+static inline bool
+svcxdr_decode_string(struct xdr_stream *xdr, char **data, unsigned int *data_len)
+{
+	__be32 *p;
+	u32 len;
+
+	if (xdr_stream_decode_u32(xdr, &len) < 0)
+		return false;
+	if (len > NLM_MAXSTRLEN)
+		return false;
+	p = xdr_inline_decode(xdr, len);
+	if (!p)
+		return false;
+	*data_len = len;
+	*data = (char *)p;
+
+	return true;
+}
+
+/*
+ * NLM cookies are defined by specification to be a variable-length
+ * XDR opaque no longer than 1024 bytes. However, this implementation
+ * limits their length to 32 bytes, and treats zero-length cookies
+ * specially.
+ */
+static inline bool
+svcxdr_decode_cookie(struct xdr_stream *xdr, struct nlm_cookie *cookie)
+{
+	__be32 *p;
+	u32 len;
+
+	if (xdr_stream_decode_u32(xdr, &len) < 0)
+		return false;
+	if (len > NLM_MAXCOOKIELEN)
+		return false;
+	if (!len)
+		goto out_hpux;
+
+	p = xdr_inline_decode(xdr, len);
+	if (!p)
+		return false;
+	cookie->len = len;
+	memcpy(cookie->data, p, len);
+
+	return true;
+
+	/* apparently HPUX can return empty cookies */
+out_hpux:
+	cookie->len = 4;
+	memset(cookie->data, 0, 4);
+	return true;
+}
+
+static inline bool
+svcxdr_encode_cookie(struct xdr_stream *xdr, const struct nlm_cookie *cookie)
+{
+	__be32 *p;
+
+	if (xdr_stream_encode_u32(xdr, cookie->len) < 0)
+		return false;
+	p = xdr_reserve_space(xdr, cookie->len);
+	if (!p)
+		return false;
+	memcpy(p, cookie->data, cookie->len);
+
+	return true;
+}
+
+static inline bool
+svcxdr_decode_owner(struct xdr_stream *xdr, struct xdr_netobj *obj)
+{
+	__be32 *p;
+	u32 len;
+
+	if (xdr_stream_decode_u32(xdr, &len) < 0)
+		return false;
+	if (len > XDR_MAX_NETOBJ)
+		return false;
+	p = xdr_inline_decode(xdr, len);
+	if (!p)
+		return false;
+	obj->len = len;
+	obj->data = (u8 *)p;
+
+	return true;
+}
+
+static inline bool
+svcxdr_encode_owner(struct xdr_stream *xdr, const struct xdr_netobj *obj)
+{
+	if (obj->len > XDR_MAX_NETOBJ)
+		return false;
+	return xdr_stream_encode_opaque(xdr, obj->data, obj->len) > 0;
+}
+
+#endif /* _LOCKD_SVCXDR_H_ */
diff --git a/fs/lockd/trace.c b/fs/lockd/trace.c
new file mode 100644
index 0000000000..d9a6ff6e67
--- /dev/null
+++ b/fs/lockd/trace.c
@@ -0,0 +1,3 @@
+// SPDX-License-Identifier: GPL-2.0
+#define CREATE_TRACE_POINTS
+#include "trace.h"
diff --git a/fs/lockd/trace.h b/fs/lockd/trace.h
new file mode 100644
index 0000000000..7461b13b6e
--- /dev/null
+++ b/fs/lockd/trace.h
@@ -0,0 +1,106 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM lockd
+
+#if !defined(_TRACE_LOCKD_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_LOCKD_H
+
+#include <linux/tracepoint.h>
+#include <linux/crc32.h>
+#include <linux/nfs.h>
+#include <linux/lockd/lockd.h>
+
+#ifdef CONFIG_LOCKD_V4
+#define NLM_STATUS_LIST					\
+	nlm_status_code(LCK_GRANTED)			\
+	nlm_status_code(LCK_DENIED)			\
+	nlm_status_code(LCK_DENIED_NOLOCKS)		\
+	nlm_status_code(LCK_BLOCKED)			\
+	nlm_status_code(LCK_DENIED_GRACE_PERIOD)	\
+	nlm_status_code(DEADLCK)			\
+	nlm_status_code(ROFS)				\
+	nlm_status_code(STALE_FH)			\
+	nlm_status_code(FBIG)				\
+	nlm_status_code_end(FAILED)
+#else
+#define NLM_STATUS_LIST					\
+	nlm_status_code(LCK_GRANTED)			\
+	nlm_status_code(LCK_DENIED)			\
+	nlm_status_code(LCK_DENIED_NOLOCKS)		\
+	nlm_status_code(LCK_BLOCKED)			\
+	nlm_status_code_end(LCK_DENIED_GRACE_PERIOD)
+#endif
+
+#undef nlm_status_code
+#undef nlm_status_code_end
+#define nlm_status_code(x)	TRACE_DEFINE_ENUM(NLM_##x);
+#define nlm_status_code_end(x)	TRACE_DEFINE_ENUM(NLM_##x);
+
+NLM_STATUS_LIST
+
+#undef nlm_status_code
+#undef nlm_status_code_end
+#define nlm_status_code(x)	{ NLM_##x, #x },
+#define nlm_status_code_end(x)	{ NLM_##x, #x }
+
+#define show_nlm_status(x)	__print_symbolic(x, NLM_STATUS_LIST)
+
+DECLARE_EVENT_CLASS(nlmclnt_lock_event,
+		TP_PROTO(
+			const struct nlm_lock *lock,
+			const struct sockaddr *addr,
+			unsigned int addrlen,
+			__be32 status
+		),
+
+		TP_ARGS(lock, addr, addrlen, status),
+
+		TP_STRUCT__entry(
+			__field(u32, oh)
+			__field(u32, svid)
+			__field(u32, fh)
+			__field(unsigned long, status)
+			__field(u64, start)
+			__field(u64, len)
+			__sockaddr(addr, addrlen)
+		),
+
+		TP_fast_assign(
+			__entry->oh = ~crc32_le(0xffffffff, lock->oh.data, lock->oh.len);
+			__entry->svid = lock->svid;
+			__entry->fh = nfs_fhandle_hash(&lock->fh);
+			__entry->start = lock->lock_start;
+			__entry->len = lock->lock_len;
+			__entry->status = be32_to_cpu(status);
+			__assign_sockaddr(addr, addr, addrlen);
+		),
+
+		TP_printk(
+			"addr=%pISpc oh=0x%08x svid=0x%08x fh=0x%08x start=%llu len=%llu status=%s",
+			__get_sockaddr(addr), __entry->oh, __entry->svid,
+			__entry->fh, __entry->start, __entry->len,
+			show_nlm_status(__entry->status)
+		)
+);
+
+#define DEFINE_NLMCLNT_EVENT(name)				\
+	DEFINE_EVENT(nlmclnt_lock_event, name,			\
+			TP_PROTO(				\
+				const struct nlm_lock *lock,	\
+				const struct sockaddr *addr,	\
+				unsigned int addrlen,		\
+				__be32	status			\
+			),					\
+			TP_ARGS(lock, addr, addrlen, status))
+
+DEFINE_NLMCLNT_EVENT(nlmclnt_test);
+DEFINE_NLMCLNT_EVENT(nlmclnt_lock);
+DEFINE_NLMCLNT_EVENT(nlmclnt_unlock);
+DEFINE_NLMCLNT_EVENT(nlmclnt_grant);
+
+#endif /* _TRACE_LOCKD_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE trace
+#include <trace/define_trace.h>
diff --git a/fs/lockd/xdr.c b/fs/lockd/xdr.c
new file mode 100644
index 0000000000..2fb5748dae
--- /dev/null
+++ b/fs/lockd/xdr.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/lockd/xdr.c
+ *
+ * XDR support for lockd and the lock client.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/nfs.h>
+
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/sunrpc/stats.h>
+#include <linux/lockd/lockd.h>
+
+#include <uapi/linux/nfs2.h>
+
+#include "svcxdr.h"
+
+
+static inline loff_t
+s32_to_loff_t(__s32 offset)
+{
+	return (loff_t)offset;
+}
+
+static inline __s32
+loff_t_to_s32(loff_t offset)
+{
+	__s32 res;
+	if (offset >= NLM_OFFSET_MAX)
+		res = NLM_OFFSET_MAX;
+	else if (offset <= -NLM_OFFSET_MAX)
+		res = -NLM_OFFSET_MAX;
+	else
+		res = offset;
+	return res;
+}
+
+/*
+ * NLM file handles are defined by specification to be a variable-length
+ * XDR opaque no longer than 1024 bytes. However, this implementation
+ * constrains their length to exactly the length of an NFSv2 file
+ * handle.
+ */
+static bool
+svcxdr_decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
+{
+	__be32 *p;
+	u32 len;
+
+	if (xdr_stream_decode_u32(xdr, &len) < 0)
+		return false;
+	if (len != NFS2_FHSIZE)
+		return false;
+
+	p = xdr_inline_decode(xdr, len);
+	if (!p)
+		return false;
+	fh->size = NFS2_FHSIZE;
+	memcpy(fh->data, p, len);
+	memset(fh->data + NFS2_FHSIZE, 0, sizeof(fh->data) - NFS2_FHSIZE);
+
+	return true;
+}
+
+static bool
+svcxdr_decode_lock(struct xdr_stream *xdr, struct nlm_lock *lock)
+{
+	struct file_lock *fl = &lock->fl;
+	s32 start, len, end;
+
+	if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
+		return false;
+	if (!svcxdr_decode_fhandle(xdr, &lock->fh))
+		return false;
+	if (!svcxdr_decode_owner(xdr, &lock->oh))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &lock->svid) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &start) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &len) < 0)
+		return false;
+
+	locks_init_lock(fl);
+	fl->fl_flags = FL_POSIX;
+	fl->fl_type  = F_RDLCK;
+	end = start + len - 1;
+	fl->fl_start = s32_to_loff_t(start);
+	if (len == 0 || end < 0)
+		fl->fl_end = OFFSET_MAX;
+	else
+		fl->fl_end = s32_to_loff_t(end);
+
+	return true;
+}
+
+static bool
+svcxdr_encode_holder(struct xdr_stream *xdr, const struct nlm_lock *lock)
+{
+	const struct file_lock *fl = &lock->fl;
+	s32 start, len;
+
+	/* exclusive */
+	if (xdr_stream_encode_bool(xdr, fl->fl_type != F_RDLCK) < 0)
+		return false;
+	if (xdr_stream_encode_u32(xdr, lock->svid) < 0)
+		return false;
+	if (!svcxdr_encode_owner(xdr, &lock->oh))
+		return false;
+	start = loff_t_to_s32(fl->fl_start);
+	if (fl->fl_end == OFFSET_MAX)
+		len = 0;
+	else
+		len = loff_t_to_s32(fl->fl_end - fl->fl_start + 1);
+	if (xdr_stream_encode_u32(xdr, start) < 0)
+		return false;
+	if (xdr_stream_encode_u32(xdr, len) < 0)
+		return false;
+
+	return true;
+}
+
+static bool
+svcxdr_encode_testrply(struct xdr_stream *xdr, const struct nlm_res *resp)
+{
+	if (!svcxdr_encode_stats(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nlm_lck_denied:
+		if (!svcxdr_encode_holder(xdr, &resp->lock))
+			return false;
+	}
+
+	return true;
+}
+
+
+/*
+ * Decode Call arguments
+ */
+
+bool
+nlmsvc_decode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	return true;
+}
+
+bool
+nlmsvc_decode_testargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	u32 exclusive;
+
+	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
+		return false;
+	if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
+		return false;
+	if (!svcxdr_decode_lock(xdr, &argp->lock))
+		return false;
+	if (exclusive)
+		argp->lock.fl.fl_type = F_WRLCK;
+
+	return true;
+}
+
+bool
+nlmsvc_decode_lockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	u32 exclusive;
+
+	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
+		return false;
+	if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
+		return false;
+	if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
+		return false;
+	if (!svcxdr_decode_lock(xdr, &argp->lock))
+		return false;
+	if (exclusive)
+		argp->lock.fl.fl_type = F_WRLCK;
+	if (xdr_stream_decode_bool(xdr, &argp->reclaim) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
+		return false;
+	argp->monitor = 1;		/* monitor client by default */
+
+	return true;
+}
+
+bool
+nlmsvc_decode_cancargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	u32 exclusive;
+
+	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
+		return false;
+	if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
+		return false;
+	if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
+		return false;
+	if (!svcxdr_decode_lock(xdr, &argp->lock))
+		return false;
+	if (exclusive)
+		argp->lock.fl.fl_type = F_WRLCK;
+
+	return true;
+}
+
+bool
+nlmsvc_decode_unlockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+
+	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
+		return false;
+	if (!svcxdr_decode_lock(xdr, &argp->lock))
+		return false;
+	argp->lock.fl.fl_type = F_UNLCK;
+
+	return true;
+}
+
+bool
+nlmsvc_decode_res(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_res *resp = rqstp->rq_argp;
+
+	if (!svcxdr_decode_cookie(xdr, &resp->cookie))
+		return false;
+	if (!svcxdr_decode_stats(xdr, &resp->status))
+		return false;
+
+	return true;
+}
+
+bool
+nlmsvc_decode_reboot(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_reboot *argp = rqstp->rq_argp;
+	__be32 *p;
+	u32 len;
+
+	if (xdr_stream_decode_u32(xdr, &len) < 0)
+		return false;
+	if (len > SM_MAXSTRLEN)
+		return false;
+	p = xdr_inline_decode(xdr, len);
+	if (!p)
+		return false;
+	argp->len = len;
+	argp->mon = (char *)p;
+	if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
+		return false;
+	p = xdr_inline_decode(xdr, SM_PRIV_SIZE);
+	if (!p)
+		return false;
+	memcpy(&argp->priv.data, p, sizeof(argp->priv.data));
+
+	return true;
+}
+
+bool
+nlmsvc_decode_shareargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_lock	*lock = &argp->lock;
+
+	memset(lock, 0, sizeof(*lock));
+	locks_init_lock(&lock->fl);
+	lock->svid = ~(u32)0;
+
+	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
+		return false;
+	if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
+		return false;
+	if (!svcxdr_decode_fhandle(xdr, &lock->fh))
+		return false;
+	if (!svcxdr_decode_owner(xdr, &lock->oh))
+		return false;
+	/* XXX: Range checks are missing in the original code */
+	if (xdr_stream_decode_u32(xdr, &argp->fsm_mode) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &argp->fsm_access) < 0)
+		return false;
+
+	return true;
+}
+
+bool
+nlmsvc_decode_notify(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_lock	*lock = &argp->lock;
+
+	if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
+		return false;
+
+	return true;
+}
+
+
+/*
+ * Encode Reply results
+ */
+
+bool
+nlmsvc_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	return true;
+}
+
+bool
+nlmsvc_encode_testres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_res *resp = rqstp->rq_resp;
+
+	return svcxdr_encode_cookie(xdr, &resp->cookie) &&
+		svcxdr_encode_testrply(xdr, resp);
+}
+
+bool
+nlmsvc_encode_res(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_res *resp = rqstp->rq_resp;
+
+	return svcxdr_encode_cookie(xdr, &resp->cookie) &&
+		svcxdr_encode_stats(xdr, resp->status);
+}
+
+bool
+nlmsvc_encode_shareres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_res *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_cookie(xdr, &resp->cookie))
+		return false;
+	if (!svcxdr_encode_stats(xdr, resp->status))
+		return false;
+	/* sequence */
+	if (xdr_stream_encode_u32(xdr, 0) < 0)
+		return false;
+
+	return true;
+}
diff --git a/fs/lockd/xdr4.c b/fs/lockd/xdr4.c
new file mode 100644
index 0000000000..5fcbf30cd2
--- /dev/null
+++ b/fs/lockd/xdr4.c
@@ -0,0 +1,349 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/lockd/xdr4.c
+ *
+ * XDR support for lockd and the lock client.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ * Copyright (C) 1999, Trond Myklebust <trond.myklebust@fys.uio.no>
+ */
+
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/nfs.h>
+
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/sunrpc/stats.h>
+#include <linux/lockd/lockd.h>
+
+#include "svcxdr.h"
+
+static inline s64
+loff_t_to_s64(loff_t offset)
+{
+	s64 res;
+	if (offset > NLM4_OFFSET_MAX)
+		res = NLM4_OFFSET_MAX;
+	else if (offset < -NLM4_OFFSET_MAX)
+		res = -NLM4_OFFSET_MAX;
+	else
+		res = offset;
+	return res;
+}
+
+void nlm4svc_set_file_lock_range(struct file_lock *fl, u64 off, u64 len)
+{
+	s64 end = off + len - 1;
+
+	fl->fl_start = off;
+	if (len == 0 || end < 0)
+		fl->fl_end = OFFSET_MAX;
+	else
+		fl->fl_end = end;
+}
+
+/*
+ * NLM file handles are defined by specification to be a variable-length
+ * XDR opaque no longer than 1024 bytes. However, this implementation
+ * limits their length to the size of an NFSv3 file handle.
+ */
+static bool
+svcxdr_decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
+{
+	__be32 *p;
+	u32 len;
+
+	if (xdr_stream_decode_u32(xdr, &len) < 0)
+		return false;
+	if (len > NFS_MAXFHSIZE)
+		return false;
+
+	p = xdr_inline_decode(xdr, len);
+	if (!p)
+		return false;
+	fh->size = len;
+	memcpy(fh->data, p, len);
+	memset(fh->data + len, 0, sizeof(fh->data) - len);
+
+	return true;
+}
+
+static bool
+svcxdr_decode_lock(struct xdr_stream *xdr, struct nlm_lock *lock)
+{
+	struct file_lock *fl = &lock->fl;
+
+	if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
+		return false;
+	if (!svcxdr_decode_fhandle(xdr, &lock->fh))
+		return false;
+	if (!svcxdr_decode_owner(xdr, &lock->oh))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &lock->svid) < 0)
+		return false;
+	if (xdr_stream_decode_u64(xdr, &lock->lock_start) < 0)
+		return false;
+	if (xdr_stream_decode_u64(xdr, &lock->lock_len) < 0)
+		return false;
+
+	locks_init_lock(fl);
+	fl->fl_flags = FL_POSIX;
+	fl->fl_type  = F_RDLCK;
+	nlm4svc_set_file_lock_range(fl, lock->lock_start, lock->lock_len);
+	return true;
+}
+
+static bool
+svcxdr_encode_holder(struct xdr_stream *xdr, const struct nlm_lock *lock)
+{
+	const struct file_lock *fl = &lock->fl;
+	s64 start, len;
+
+	/* exclusive */
+	if (xdr_stream_encode_bool(xdr, fl->fl_type != F_RDLCK) < 0)
+		return false;
+	if (xdr_stream_encode_u32(xdr, lock->svid) < 0)
+		return false;
+	if (!svcxdr_encode_owner(xdr, &lock->oh))
+		return false;
+	start = loff_t_to_s64(fl->fl_start);
+	if (fl->fl_end == OFFSET_MAX)
+		len = 0;
+	else
+		len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
+	if (xdr_stream_encode_u64(xdr, start) < 0)
+		return false;
+	if (xdr_stream_encode_u64(xdr, len) < 0)
+		return false;
+
+	return true;
+}
+
+static bool
+svcxdr_encode_testrply(struct xdr_stream *xdr, const struct nlm_res *resp)
+{
+	if (!svcxdr_encode_stats(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nlm_lck_denied:
+		if (!svcxdr_encode_holder(xdr, &resp->lock))
+			return false;
+	}
+
+	return true;
+}
+
+
+/*
+ * Decode Call arguments
+ */
+
+bool
+nlm4svc_decode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	return true;
+}
+
+bool
+nlm4svc_decode_testargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	u32 exclusive;
+
+	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
+		return false;
+	if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
+		return false;
+	if (!svcxdr_decode_lock(xdr, &argp->lock))
+		return false;
+	if (exclusive)
+		argp->lock.fl.fl_type = F_WRLCK;
+
+	return true;
+}
+
+bool
+nlm4svc_decode_lockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	u32 exclusive;
+
+	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
+		return false;
+	if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
+		return false;
+	if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
+		return false;
+	if (!svcxdr_decode_lock(xdr, &argp->lock))
+		return false;
+	if (exclusive)
+		argp->lock.fl.fl_type = F_WRLCK;
+	if (xdr_stream_decode_bool(xdr, &argp->reclaim) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
+		return false;
+	argp->monitor = 1;		/* monitor client by default */
+
+	return true;
+}
+
+bool
+nlm4svc_decode_cancargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	u32 exclusive;
+
+	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
+		return false;
+	if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
+		return false;
+	if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
+		return false;
+	if (!svcxdr_decode_lock(xdr, &argp->lock))
+		return false;
+	if (exclusive)
+		argp->lock.fl.fl_type = F_WRLCK;
+
+	return true;
+}
+
+bool
+nlm4svc_decode_unlockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+
+	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
+		return false;
+	if (!svcxdr_decode_lock(xdr, &argp->lock))
+		return false;
+	argp->lock.fl.fl_type = F_UNLCK;
+
+	return true;
+}
+
+bool
+nlm4svc_decode_res(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_res *resp = rqstp->rq_argp;
+
+	if (!svcxdr_decode_cookie(xdr, &resp->cookie))
+		return false;
+	if (!svcxdr_decode_stats(xdr, &resp->status))
+		return false;
+
+	return true;
+}
+
+bool
+nlm4svc_decode_reboot(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_reboot *argp = rqstp->rq_argp;
+	__be32 *p;
+	u32 len;
+
+	if (xdr_stream_decode_u32(xdr, &len) < 0)
+		return false;
+	if (len > SM_MAXSTRLEN)
+		return false;
+	p = xdr_inline_decode(xdr, len);
+	if (!p)
+		return false;
+	argp->len = len;
+	argp->mon = (char *)p;
+	if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
+		return false;
+	p = xdr_inline_decode(xdr, SM_PRIV_SIZE);
+	if (!p)
+		return false;
+	memcpy(&argp->priv.data, p, sizeof(argp->priv.data));
+
+	return true;
+}
+
+bool
+nlm4svc_decode_shareargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_lock	*lock = &argp->lock;
+
+	memset(lock, 0, sizeof(*lock));
+	locks_init_lock(&lock->fl);
+	lock->svid = ~(u32)0;
+
+	if (!svcxdr_decode_cookie(xdr, &argp->cookie))
+		return false;
+	if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
+		return false;
+	if (!svcxdr_decode_fhandle(xdr, &lock->fh))
+		return false;
+	if (!svcxdr_decode_owner(xdr, &lock->oh))
+		return false;
+	/* XXX: Range checks are missing in the original code */
+	if (xdr_stream_decode_u32(xdr, &argp->fsm_mode) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &argp->fsm_access) < 0)
+		return false;
+
+	return true;
+}
+
+bool
+nlm4svc_decode_notify(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_args *argp = rqstp->rq_argp;
+	struct nlm_lock	*lock = &argp->lock;
+
+	if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
+		return false;
+
+	return true;
+}
+
+
+/*
+ * Encode Reply results
+ */
+
+bool
+nlm4svc_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	return true;
+}
+
+bool
+nlm4svc_encode_testres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_res *resp = rqstp->rq_resp;
+
+	return svcxdr_encode_cookie(xdr, &resp->cookie) &&
+		svcxdr_encode_testrply(xdr, resp);
+}
+
+bool
+nlm4svc_encode_res(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_res *resp = rqstp->rq_resp;
+
+	return svcxdr_encode_cookie(xdr, &resp->cookie) &&
+		svcxdr_encode_stats(xdr, resp->status);
+}
+
+bool
+nlm4svc_encode_shareres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nlm_res *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_cookie(xdr, &resp->cookie))
+		return false;
+	if (!svcxdr_encode_stats(xdr, resp->status))
+		return false;
+	/* sequence */
+	if (xdr_stream_encode_u32(xdr, 0) < 0)
+		return false;
+
+	return true;
+}