nfsd: remove fault injection code

It was an interesting idea but nobody seems to be using it, it's buggy
at this point, and nfs4state.c is already complicated enough without it.
The new nfsd/clients/ code provides some of the same functionality, and
could probably do more if desired.

This feature has been deprecated since 9d60d93198c6 ("Deprecate nfsd
fault injection").

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

8 files changed, 0 insertions, 755 deletions

diff --git a/Documentation/admin-guide/nfs/fault_injection.rst b/Documentation/admin-guide/nfs/fault_injection.rst
deleted file mode 100644
index eb029c0c15ce..000000000000
--- a/Documentation/admin-guide/nfs/fault_injection.rst
+++ /dev/null
@@ -1,70 +0,0 @@
-===================
-NFS Fault Injection
-===================
-
-Fault injection is a method for forcing errors that may not normally occur, or
-may be difficult to reproduce.  Forcing these errors in a controlled environment
-can help the developer find and fix bugs before their code is shipped in a
-production system.  Injecting an error on the Linux NFS server will allow us to
-observe how the client reacts and if it manages to recover its state correctly.
-
-NFSD_FAULT_INJECTION must be selected when configuring the kernel to use this
-feature.
-
-
-Using Fault Injection
-=====================
-On the client, mount the fault injection server through NFS v4.0+ and do some
-work over NFS (open files, take locks, ...).
-
-On the server, mount the debugfs filesystem to <debug_dir> and ls
-<debug_dir>/nfsd.  This will show a list of files that will be used for
-injecting faults on the NFS server.  As root, write a number n to the file
-corresponding to the action you want the server to take.  The server will then
-process the first n items it finds.  So if you want to forget 5 locks, echo '5'
-to <debug_dir>/nfsd/forget_locks.  A value of 0 will tell the server to forget
-all corresponding items.  A log message will be created containing the number
-of items forgotten (check dmesg).
-
-Go back to work on the client and check if the client recovered from the error
-correctly.
-
-
-Available Faults
-================
-forget_clients:
-     The NFS server keeps a list of clients that have placed a mount call.  If
-     this list is cleared, the server will have no knowledge of who the client
-     is, forcing the client to reauthenticate with the server.
-
-forget_openowners:
-     The NFS server keeps a list of what files are currently opened and who
-     they were opened by.  Clearing this list will force the client to reopen
-     its files.
-
-forget_locks:
-     The NFS server keeps a list of what files are currently locked in the VFS.
-     Clearing this list will force the client to reclaim its locks (files are
-     unlocked through the VFS as they are cleared from this list).
-
-forget_delegations:
-     A delegation is used to assure the client that a file, or part of a file,
-     has not changed since the delegation was awarded.  Clearing this list will
-     force the client to reacquire its delegation before accessing the file
-     again.
-
-recall_delegations:
-     Delegations can be recalled by the server when another client attempts to
-     access a file.  This test will notify the client that its delegation has
-     been revoked, forcing the client to reacquire the delegation before using
-     the file again.
-
-
-tools/nfs/inject_faults.sh script
-=================================
-This script has been created to ease the fault injection process.  This script
-will detect the mounted debugfs directory and write to the files located there
-based on the arguments passed by the user.  For example, running
-`inject_faults.sh forget_locks 1` as root will instruct the server to forget
-one lock.  Running `inject_faults forget_locks` will instruct the server to
-forgetall locks.
diff --git a/Documentation/admin-guide/nfs/index.rst b/Documentation/admin-guide/nfs/index.rst
index 6b5a3c90fac5..3601a708f333 100644
--- a/Documentation/admin-guide/nfs/index.rst
+++ b/Documentation/admin-guide/nfs/index.rst
@@ -12,4 +12,3 @@ NFS
     nfs-idmapper
     pnfs-block-server
     pnfs-scsi-server
-    fault_injection
diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig
index 99d2cae91bd6..9223e13c3051 100644
--- a/fs/nfsd/Kconfig
+++ b/fs/nfsd/Kconfig
@@ -156,13 +156,3 @@ config NFSD_V4_SECURITY_LABEL
 
 	If you do not wish to enable fine-grained security labels SELinux or
 	Smack policies on NFSv4 files, say N.
-
-config NFSD_FAULT_INJECTION
-	bool "NFS server manual fault injection"
-	depends on NFSD_V4 && DEBUG_KERNEL && DEBUG_FS && BROKEN
-	help
-	  This option enables support for manually injecting faults
-	  into the NFS server.  This is intended to be used for
-	  testing error recovery on the NFS client.
-
-	  If unsure, say N.
diff --git a/fs/nfsd/Makefile b/fs/nfsd/Makefile
index 6a40b1afe703..3f0983e93a99 100644
--- a/fs/nfsd/Makefile
+++ b/fs/nfsd/Makefile
@@ -13,7 +13,6 @@ nfsd-y			+= trace.o
 nfsd-y 			+= nfssvc.o nfsctl.o nfsproc.o nfsfh.o vfs.o \
 			   export.o auth.o lockd.o nfscache.o nfsxdr.o \
 			   stats.o filecache.o
-nfsd-$(CONFIG_NFSD_FAULT_INJECTION) += fault_inject.o
 nfsd-$(CONFIG_NFSD_V2_ACL) += nfs2acl.o
 nfsd-$(CONFIG_NFSD_V3)	+= nfs3proc.o nfs3xdr.o
 nfsd-$(CONFIG_NFSD_V3_ACL) += nfs3acl.o
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index c09a2a4281ec..a31ba0e4ef2f 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -7253,599 +7253,6 @@ nfs4_check_open_reclaim(clientid_t *clid,
 	return nfs_ok;
 }
 
-#ifdef CONFIG_NFSD_FAULT_INJECTION
-static inline void
-put_client(struct nfs4_client *clp)
-{
-	atomic_dec(&clp->cl_rpc_users);
-}
-
-static struct nfs4_client *
-nfsd_find_client(struct sockaddr_storage *addr, size_t addr_size)
-{
-	struct nfs4_client *clp;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-					  nfsd_net_id);
-
-	if (!nfsd_netns_ready(nn))
-		return NULL;
-
-	list_for_each_entry(clp, &nn->client_lru, cl_lru) {
-		if (memcmp(&clp->cl_addr, addr, addr_size) == 0)
-			return clp;
-	}
-	return NULL;
-}
-
-u64
-nfsd_inject_print_clients(void)
-{
-	struct nfs4_client *clp;
-	u64 count = 0;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-					  nfsd_net_id);
-	char buf[INET6_ADDRSTRLEN];
-
-	if (!nfsd_netns_ready(nn))
-		return 0;
-
-	spin_lock(&nn->client_lock);
-	list_for_each_entry(clp, &nn->client_lru, cl_lru) {
-		rpc_ntop((struct sockaddr *)&clp->cl_addr, buf, sizeof(buf));
-		pr_info("NFS Client: %s\n", buf);
-		++count;
-	}
-	spin_unlock(&nn->client_lock);
-
-	return count;
-}
-
-u64
-nfsd_inject_forget_client(struct sockaddr_storage *addr, size_t addr_size)
-{
-	u64 count = 0;
-	struct nfs4_client *clp;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-					  nfsd_net_id);
-
-	if (!nfsd_netns_ready(nn))
-		return count;
-
-	spin_lock(&nn->client_lock);
-	clp = nfsd_find_client(addr, addr_size);
-	if (clp) {
-		if (mark_client_expired_locked(clp) == nfs_ok)
-			++count;
-		else
-			clp = NULL;
-	}
-	spin_unlock(&nn->client_lock);
-
-	if (clp)
-		expire_client(clp);
-
-	return count;
-}
-
-u64
-nfsd_inject_forget_clients(u64 max)
-{
-	u64 count = 0;
-	struct nfs4_client *clp, *next;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-	LIST_HEAD(reaplist);
-
-	if (!nfsd_netns_ready(nn))
-		return count;
-
-	spin_lock(&nn->client_lock);
-	list_for_each_entry_safe(clp, next, &nn->client_lru, cl_lru) {
-		if (mark_client_expired_locked(clp) == nfs_ok) {
-			list_add(&clp->cl_lru, &reaplist);
-			if (max != 0 && ++count >= max)
-				break;
-		}
-	}
-	spin_unlock(&nn->client_lock);
-
-	list_for_each_entry_safe(clp, next, &reaplist, cl_lru)
-		expire_client(clp);
-
-	return count;
-}
-
-static void nfsd_print_count(struct nfs4_client *clp, unsigned int count,
-			     const char *type)
-{
-	char buf[INET6_ADDRSTRLEN];
-	rpc_ntop((struct sockaddr *)&clp->cl_addr, buf, sizeof(buf));
-	printk(KERN_INFO "NFS Client: %s has %u %s\n", buf, count, type);
-}
-
-static void
-nfsd_inject_add_lock_to_list(struct nfs4_ol_stateid *lst,
-			     struct list_head *collect)
-{
-	struct nfs4_client *clp = lst->st_stid.sc_client;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-					  nfsd_net_id);
-
-	if (!collect)
-		return;
-
-	lockdep_assert_held(&nn->client_lock);
-	atomic_inc(&clp->cl_rpc_users);
-	list_add(&lst->st_locks, collect);
-}
-
-static u64 nfsd_foreach_client_lock(struct nfs4_client *clp, u64 max,
-				    struct list_head *collect,
-				    bool (*func)(struct nfs4_ol_stateid *))
-{
-	struct nfs4_openowner *oop;
-	struct nfs4_ol_stateid *stp, *st_next;
-	struct nfs4_ol_stateid *lst, *lst_next;
-	u64 count = 0;
-
-	spin_lock(&clp->cl_lock);
-	list_for_each_entry(oop, &clp->cl_openowners, oo_perclient) {
-		list_for_each_entry_safe(stp, st_next,
-				&oop->oo_owner.so_stateids, st_perstateowner) {
-			list_for_each_entry_safe(lst, lst_next,
-					&stp->st_locks, st_locks) {
-				if (func) {
-					if (func(lst))
-						nfsd_inject_add_lock_to_list(lst,
-									collect);
-				}
-				++count;
-				/*
-				 * Despite the fact that these functions deal
-				 * with 64-bit integers for "count", we must
-				 * ensure that it doesn't blow up the
-				 * clp->cl_rpc_users. Throw a warning if we
-				 * start to approach INT_MAX here.
-				 */
-				WARN_ON_ONCE(count == (INT_MAX / 2));
-				if (count == max)
-					goto out;
-			}
-		}
-	}
-out:
-	spin_unlock(&clp->cl_lock);
-
-	return count;
-}
-
-static u64
-nfsd_collect_client_locks(struct nfs4_client *clp, struct list_head *collect,
-			  u64 max)
-{
-	return nfsd_foreach_client_lock(clp, max, collect, unhash_lock_stateid);
-}
-
-static u64
-nfsd_print_client_locks(struct nfs4_client *clp)
-{
-	u64 count = nfsd_foreach_client_lock(clp, 0, NULL, NULL);
-	nfsd_print_count(clp, count, "locked files");
-	return count;
-}
-
-u64
-nfsd_inject_print_locks(void)
-{
-	struct nfs4_client *clp;
-	u64 count = 0;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-
-	if (!nfsd_netns_ready(nn))
-		return 0;
-
-	spin_lock(&nn->client_lock);
-	list_for_each_entry(clp, &nn->client_lru, cl_lru)
-		count += nfsd_print_client_locks(clp);
-	spin_unlock(&nn->client_lock);
-
-	return count;
-}
-
-static void
-nfsd_reap_locks(struct list_head *reaplist)
-{
-	struct nfs4_client *clp;
-	struct nfs4_ol_stateid *stp, *next;
-
-	list_for_each_entry_safe(stp, next, reaplist, st_locks) {
-		list_del_init(&stp->st_locks);
-		clp = stp->st_stid.sc_client;
-		nfs4_put_stid(&stp->st_stid);
-		put_client(clp);
-	}
-}
-
-u64
-nfsd_inject_forget_client_locks(struct sockaddr_storage *addr, size_t addr_size)
-{
-	unsigned int count = 0;
-	struct nfs4_client *clp;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-	LIST_HEAD(reaplist);
-
-	if (!nfsd_netns_ready(nn))
-		return count;
-
-	spin_lock(&nn->client_lock);
-	clp = nfsd_find_client(addr, addr_size);
-	if (clp)
-		count = nfsd_collect_client_locks(clp, &reaplist, 0);
-	spin_unlock(&nn->client_lock);
-	nfsd_reap_locks(&reaplist);
-	return count;
-}
-
-u64
-nfsd_inject_forget_locks(u64 max)
-{
-	u64 count = 0;
-	struct nfs4_client *clp;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-	LIST_HEAD(reaplist);
-
-	if (!nfsd_netns_ready(nn))
-		return count;
-
-	spin_lock(&nn->client_lock);
-	list_for_each_entry(clp, &nn->client_lru, cl_lru) {
-		count += nfsd_collect_client_locks(clp, &reaplist, max - count);
-		if (max != 0 && count >= max)
-			break;
-	}
-	spin_unlock(&nn->client_lock);
-	nfsd_reap_locks(&reaplist);
-	return count;
-}
-
-static u64
-nfsd_foreach_client_openowner(struct nfs4_client *clp, u64 max,
-			      struct list_head *collect,
-			      void (*func)(struct nfs4_openowner *))
-{
-	struct nfs4_openowner *oop, *next;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-	u64 count = 0;
-
-	lockdep_assert_held(&nn->client_lock);
-
-	spin_lock(&clp->cl_lock);
-	list_for_each_entry_safe(oop, next, &clp->cl_openowners, oo_perclient) {
-		if (func) {
-			func(oop);
-			if (collect) {
-				atomic_inc(&clp->cl_rpc_users);
-				list_add(&oop->oo_perclient, collect);
-			}
-		}
-		++count;
-		/*
-		 * Despite the fact that these functions deal with
-		 * 64-bit integers for "count", we must ensure that
-		 * it doesn't blow up the clp->cl_rpc_users. Throw a
-		 * warning if we start to approach INT_MAX here.
-		 */
-		WARN_ON_ONCE(count == (INT_MAX / 2));
-		if (count == max)
-			break;
-	}
-	spin_unlock(&clp->cl_lock);
-
-	return count;
-}
-
-static u64
-nfsd_print_client_openowners(struct nfs4_client *clp)
-{
-	u64 count = nfsd_foreach_client_openowner(clp, 0, NULL, NULL);
-
-	nfsd_print_count(clp, count, "openowners");
-	return count;
-}
-
-static u64
-nfsd_collect_client_openowners(struct nfs4_client *clp,
-			       struct list_head *collect, u64 max)
-{
-	return nfsd_foreach_client_openowner(clp, max, collect,
-						unhash_openowner_locked);
-}
-
-u64
-nfsd_inject_print_openowners(void)
-{
-	struct nfs4_client *clp;
-	u64 count = 0;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-
-	if (!nfsd_netns_ready(nn))
-		return 0;
-
-	spin_lock(&nn->client_lock);
-	list_for_each_entry(clp, &nn->client_lru, cl_lru)
-		count += nfsd_print_client_openowners(clp);
-	spin_unlock(&nn->client_lock);
-
-	return count;
-}
-
-static void
-nfsd_reap_openowners(struct list_head *reaplist)
-{
-	struct nfs4_client *clp;
-	struct nfs4_openowner *oop, *next;
-
-	list_for_each_entry_safe(oop, next, reaplist, oo_perclient) {
-		list_del_init(&oop->oo_perclient);
-		clp = oop->oo_owner.so_client;
-		release_openowner(oop);
-		put_client(clp);
-	}
-}
-
-u64
-nfsd_inject_forget_client_openowners(struct sockaddr_storage *addr,
-				     size_t addr_size)
-{
-	unsigned int count = 0;
-	struct nfs4_client *clp;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-	LIST_HEAD(reaplist);
-
-	if (!nfsd_netns_ready(nn))
-		return count;
-
-	spin_lock(&nn->client_lock);
-	clp = nfsd_find_client(addr, addr_size);
-	if (clp)
-		count = nfsd_collect_client_openowners(clp, &reaplist, 0);
-	spin_unlock(&nn->client_lock);
-	nfsd_reap_openowners(&reaplist);
-	return count;
-}
-
-u64
-nfsd_inject_forget_openowners(u64 max)
-{
-	u64 count = 0;
-	struct nfs4_client *clp;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-	LIST_HEAD(reaplist);
-
-	if (!nfsd_netns_ready(nn))
-		return count;
-
-	spin_lock(&nn->client_lock);
-	list_for_each_entry(clp, &nn->client_lru, cl_lru) {
-		count += nfsd_collect_client_openowners(clp, &reaplist,
-							max - count);
-		if (max != 0 && count >= max)
-			break;
-	}
-	spin_unlock(&nn->client_lock);
-	nfsd_reap_openowners(&reaplist);
-	return count;
-}
-
-static u64 nfsd_find_all_delegations(struct nfs4_client *clp, u64 max,
-				     struct list_head *victims)
-{
-	struct nfs4_delegation *dp, *next;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-	u64 count = 0;
-
-	lockdep_assert_held(&nn->client_lock);
-
-	spin_lock(&state_lock);
-	list_for_each_entry_safe(dp, next, &clp->cl_delegations, dl_perclnt) {
-		if (victims) {
-			/*
-			 * It's not safe to mess with delegations that have a
-			 * non-zero dl_time. They might have already been broken
-			 * and could be processed by the laundromat outside of
-			 * the state_lock. Just leave them be.
-			 */
-			if (dp->dl_time != 0)
-				continue;
-
-			atomic_inc(&clp->cl_rpc_users);
-			WARN_ON(!unhash_delegation_locked(dp));
-			list_add(&dp->dl_recall_lru, victims);
-		}
-		++count;
-		/*
-		 * Despite the fact that these functions deal with
-		 * 64-bit integers for "count", we must ensure that
-		 * it doesn't blow up the clp->cl_rpc_users. Throw a
-		 * warning if we start to approach INT_MAX here.
-		 */
-		WARN_ON_ONCE(count == (INT_MAX / 2));
-		if (count == max)
-			break;
-	}
-	spin_unlock(&state_lock);
-	return count;
-}
-
-static u64
-nfsd_print_client_delegations(struct nfs4_client *clp)
-{
-	u64 count = nfsd_find_all_delegations(clp, 0, NULL);
-
-	nfsd_print_count(clp, count, "delegations");
-	return count;
-}
-
-u64
-nfsd_inject_print_delegations(void)
-{
-	struct nfs4_client *clp;
-	u64 count = 0;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-
-	if (!nfsd_netns_ready(nn))
-		return 0;
-
-	spin_lock(&nn->client_lock);
-	list_for_each_entry(clp, &nn->client_lru, cl_lru)
-		count += nfsd_print_client_delegations(clp);
-	spin_unlock(&nn->client_lock);
-
-	return count;
-}
-
-static void
-nfsd_forget_delegations(struct list_head *reaplist)
-{
-	struct nfs4_client *clp;
-	struct nfs4_delegation *dp, *next;
-
-	list_for_each_entry_safe(dp, next, reaplist, dl_recall_lru) {
-		list_del_init(&dp->dl_recall_lru);
-		clp = dp->dl_stid.sc_client;
-		revoke_delegation(dp);
-		put_client(clp);
-	}
-}
-
-u64
-nfsd_inject_forget_client_delegations(struct sockaddr_storage *addr,
-				      size_t addr_size)
-{
-	u64 count = 0;
-	struct nfs4_client *clp;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-	LIST_HEAD(reaplist);
-
-	if (!nfsd_netns_ready(nn))
-		return count;
-
-	spin_lock(&nn->client_lock);
-	clp = nfsd_find_client(addr, addr_size);
-	if (clp)
-		count = nfsd_find_all_delegations(clp, 0, &reaplist);
-	spin_unlock(&nn->client_lock);
-
-	nfsd_forget_delegations(&reaplist);
-	return count;
-}
-
-u64
-nfsd_inject_forget_delegations(u64 max)
-{
-	u64 count = 0;
-	struct nfs4_client *clp;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-	LIST_HEAD(reaplist);
-
-	if (!nfsd_netns_ready(nn))
-		return count;
-
-	spin_lock(&nn->client_lock);
-	list_for_each_entry(clp, &nn->client_lru, cl_lru) {
-		count += nfsd_find_all_delegations(clp, max - count, &reaplist);
-		if (max != 0 && count >= max)
-			break;
-	}
-	spin_unlock(&nn->client_lock);
-	nfsd_forget_delegations(&reaplist);
-	return count;
-}
-
-static void
-nfsd_recall_delegations(struct list_head *reaplist)
-{
-	struct nfs4_client *clp;
-	struct nfs4_delegation *dp, *next;
-
-	list_for_each_entry_safe(dp, next, reaplist, dl_recall_lru) {
-		list_del_init(&dp->dl_recall_lru);
-		clp = dp->dl_stid.sc_client;
-
-		trace_nfsd_deleg_recall(&dp->dl_stid.sc_stateid);
-
-		/*
-		 * We skipped all entries that had a zero dl_time before,
-		 * so we can now reset the dl_time back to 0. If a delegation
-		 * break comes in now, then it won't make any difference since
-		 * we're recalling it either way.
-		 */
-		spin_lock(&state_lock);
-		dp->dl_time = 0;
-		spin_unlock(&state_lock);
-		nfsd_break_one_deleg(dp);
-		put_client(clp);
-	}
-}
-
-u64
-nfsd_inject_recall_client_delegations(struct sockaddr_storage *addr,
-				      size_t addr_size)
-{
-	u64 count = 0;
-	struct nfs4_client *clp;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-	LIST_HEAD(reaplist);
-
-	if (!nfsd_netns_ready(nn))
-		return count;
-
-	spin_lock(&nn->client_lock);
-	clp = nfsd_find_client(addr, addr_size);
-	if (clp)
-		count = nfsd_find_all_delegations(clp, 0, &reaplist);
-	spin_unlock(&nn->client_lock);
-
-	nfsd_recall_delegations(&reaplist);
-	return count;
-}
-
-u64
-nfsd_inject_recall_delegations(u64 max)
-{
-	u64 count = 0;
-	struct nfs4_client *clp, *next;
-	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
-						nfsd_net_id);
-	LIST_HEAD(reaplist);
-
-	if (!nfsd_netns_ready(nn))
-		return count;
-
-	spin_lock(&nn->client_lock);
-	list_for_each_entry_safe(clp, next, &nn->client_lru, cl_lru) {
-		count += nfsd_find_all_delegations(clp, max - count, &reaplist);
-		if (max != 0 && ++count >= max)
-			break;
-	}
-	spin_unlock(&nn->client_lock);
-	nfsd_recall_delegations(&reaplist);
-	return count;
-}
-#endif /* CONFIG_NFSD_FAULT_INJECTION */
-
 /*
  * Since the lifetime of a delegation isn't limited to that of an open, a
  * client may quite reasonably hang on to a delegation as long as it has
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 7ae236113040..f6d5d783f4a4 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1534,7 +1534,6 @@ static int __init init_nfsd(void)
 	retval = nfsd4_init_pnfs();
 	if (retval)
 		goto out_free_slabs;
-	nfsd_fault_inject_init(); /* nfsd fault injection controls */
 	nfsd_stat_init();	/* Statistics */
 	retval = nfsd_drc_slab_create();
 	if (retval)
@@ -1555,7 +1554,6 @@ out_free_lockd:
 	nfsd_drc_slab_free();
 out_free_stat:
 	nfsd_stat_shutdown();
-	nfsd_fault_inject_cleanup();
 	nfsd4_exit_pnfs();
 out_free_slabs:
 	nfsd4_free_slabs();
@@ -1575,7 +1573,6 @@ static void __exit exit_nfsd(void)
 	nfsd_lockd_shutdown();
 	nfsd4_free_slabs();
 	nfsd4_exit_pnfs();
-	nfsd_fault_inject_cleanup();
 	unregister_filesystem(&nfsd_fs_type);
 	unregister_cld_notifier();
 	unregister_pernet_subsys(&nfsd_net_ops);
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 3b408532a5dc..9eae11a9d21c 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -693,31 +693,4 @@ extern void nfsd4_client_record_remove(struct nfs4_client *clp);
 extern int nfsd4_client_record_check(struct nfs4_client *clp);
 extern void nfsd4_record_grace_done(struct nfsd_net *nn);
 
-/* nfs fault injection functions */
-#ifdef CONFIG_NFSD_FAULT_INJECTION
-void nfsd_fault_inject_init(void);
-void nfsd_fault_inject_cleanup(void);
-
-u64 nfsd_inject_print_clients(void);
-u64 nfsd_inject_forget_client(struct sockaddr_storage *, size_t);
-u64 nfsd_inject_forget_clients(u64);
-
-u64 nfsd_inject_print_locks(void);
-u64 nfsd_inject_forget_client_locks(struct sockaddr_storage *, size_t);
-u64 nfsd_inject_forget_locks(u64);
-
-u64 nfsd_inject_print_openowners(void);
-u64 nfsd_inject_forget_client_openowners(struct sockaddr_storage *, size_t);
-u64 nfsd_inject_forget_openowners(u64);
-
-u64 nfsd_inject_print_delegations(void);
-u64 nfsd_inject_forget_client_delegations(struct sockaddr_storage *, size_t);
-u64 nfsd_inject_forget_delegations(u64);
-u64 nfsd_inject_recall_client_delegations(struct sockaddr_storage *, size_t);
-u64 nfsd_inject_recall_delegations(u64);
-#else /* CONFIG_NFSD_FAULT_INJECTION */
-static inline void nfsd_fault_inject_init(void) {}
-static inline void nfsd_fault_inject_cleanup(void) {}
-#endif /* CONFIG_NFSD_FAULT_INJECTION */
-
 #endif   /* NFSD4_STATE_H */
diff --git a/tools/nfsd/inject_fault.sh b/tools/nfsd/inject_fault.sh
deleted file mode 100755
index 10ceee64a09a..000000000000
--- a/tools/nfsd/inject_fault.sh
+++ /dev/null
@@ -1,50 +0,0 @@
-#!/bin/bash
-# SPDX-License-Identifier: GPL-2.0
-#
-# Copyright (c) 2011 Bryan Schumaker <bjschuma@netapp.com>
-#
-# Script for easier NFSD fault injection
-
-# Check that debugfs has been mounted
-DEBUGFS=`cat /proc/mounts | grep debugfs`
-if [ "$DEBUGFS" == "" ]; then
-	echo "debugfs does not appear to be mounted!"
-	echo "Please mount debugfs and try again"
-	exit 1
-fi
-
-# Check that the fault injection directory exists
-DEBUGDIR=`echo $DEBUGFS | awk '{print $2}'`/nfsd
-if [ ! -d "$DEBUGDIR" ]; then
-	echo "$DEBUGDIR does not exist"
-	echo "Check that your .config selects CONFIG_NFSD_FAULT_INJECTION"
-	exit 1
-fi
-
-function help()
-{
-	echo "Usage $0 injection_type [count]"
-	echo ""
-	echo "Injection types are:"
-	ls $DEBUGDIR
-	exit 1
-}
-
-if [ $# == 0 ]; then
-	help
-elif [ ! -f $DEBUGDIR/$1 ]; then
-	help
-elif [ $# != 2 ]; then
-	COUNT=0
-else
-	COUNT=$2
-fi
-
-BEFORE=`mktemp`
-AFTER=`mktemp`
-dmesg > $BEFORE
-echo $COUNT > $DEBUGDIR/$1
-dmesg > $AFTER
-# Capture lines that only exist in the $AFTER file
-diff $BEFORE $AFTER | grep ">"
-rm -f $BEFORE $AFTER