[PATCH] nfsd: remove fault injection code

[bfields@fieldses.org (J. Bruce Fields)]

From: "J. Bruce Fields" <bfields@redhat.com>

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.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 .../admin-guide/nfs/fault_injection.rst       |  70 ---
 Documentation/admin-guide/nfs/index.rst       |   1 -
 fs/nfsd/Kconfig                               |  10 -
 fs/nfsd/Makefile                              |   1 -
 fs/nfsd/nfs4state.c                           | 593 ------------------
 fs/nfsd/nfsctl.c                              |   3 -
 fs/nfsd/state.h                               |  27 -
 tools/nfsd/inject_fault.sh                    |  50 --
 8 files changed, 755 deletions(-)
 delete mode 100644 Documentation/admin-guide/nfs/fault_injection.rst
 delete mode 100755 tools/nfsd/inject_fault.sh

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 81ed8e8bab3f..4c9c79fdc3b8 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -7251,599 +7251,6 @@ 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 @@ static int __init init_nfsd(void)
 	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
-- 
2.26.2