Merge tag 'nfsd-5.3' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Highlights:

   - Add a new /proc/fs/nfsd/clients/ directory which exposes some
     long-requested information about NFSv4 clients (like open files)
     and allows forced revocation of client state.

   - Replace the global duplicate reply cache by a cache per network
     namespace; previously, a request in one network namespace could
     incorrectly match an entry from another, though we haven't seen
     this in production. This is the last remaining container bug that
     I'm aware of; at this point you should be able to run separate
     nfsd's in each network namespace, each with their own set of
     exports, and everything should work.

   - Cleanup and modify lock code to show the pid of lockd as the owner
     of NLM locks. This is the correct version of the bugfix originally
     attempted in b8eee0e90f97 ("lockd: Show pid of lockd for remote
     locks")"

* tag 'nfsd-5.3' of git://linux-nfs.org/~bfields/linux: (34 commits)
  nfsd: Make __get_nfsdfs_client() static
  nfsd: Make two functions static
  nfsd: Fix misuse of strlcpy
  sunrpc/cache: remove the exporting of cache_seq_next
  nfsd: decode implementation id
  nfsd: create xdr_netobj_dup helper
  nfsd: allow forced expiration of NFSv4 clients
  nfsd: create get_nfsdfs_clp helper
  nfsd4: show layout stateids
  nfsd: show lock and deleg stateids
  nfsd4: add file to display list of client's opens
  nfsd: add more information to client info file
  nfsd: escape high characters in binary data
  nfsd: copy client's address including port number to cl_addr
  nfsd4: add a client info file
  nfsd: make client/ directory names small ints
  nfsd: add nfsd/clients directory
  nfsd4: use reference count to free client
  nfsd: rename cl_refcount
  nfsd: persist nfsd filesystem across mounts
  ...

21 files changed, 1001 insertions, 238 deletions

diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
index 62f98225abb3..b11f2afa84f1 100644
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -47,13 +47,14 @@ void nlmclnt_next_cookie(struct nlm_cookie *c)
 	c->len=4;
 }
 
-static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner)
+static struct nlm_lockowner *
+nlmclnt_get_lockowner(struct nlm_lockowner *lockowner)
 {
 	refcount_inc(&lockowner->count);
 	return lockowner;
 }
 
-static void nlm_put_lockowner(struct nlm_lockowner *lockowner)
+static void nlmclnt_put_lockowner(struct nlm_lockowner *lockowner)
 {
 	if (!refcount_dec_and_lock(&lockowner->count, &lockowner->host->h_lock))
 		return;
@@ -82,28 +83,28 @@ static inline uint32_t __nlm_alloc_pid(struct nlm_host *host)
 	return res;
 }
 
-static struct nlm_lockowner *__nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
+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 nlm_get_lockowner(lockowner);
+		return nlmclnt_get_lockowner(lockowner);
 	}
 	return NULL;
 }
 
-static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
+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 = __nlm_find_lockowner(host, owner);
+	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 = __nlm_find_lockowner(host, owner);
+		res = __nlmclnt_find_lockowner(host, owner);
 		if (res == NULL && new != NULL) {
 			res = new;
 			refcount_set(&new->count, 1);
@@ -457,7 +458,7 @@ 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 = nlm_get_lockowner(fl->fl_u.nfs_fl.owner);
+	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);
 }
@@ -467,7 +468,7 @@ 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);
-	nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
+	nlmclnt_put_lockowner(fl->fl_u.nfs_fl.owner);
 }
 
 static const struct file_lock_operations nlmclnt_lock_ops = {
@@ -478,7 +479,7 @@ static const struct file_lock_operations nlmclnt_lock_ops = {
 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 = nlm_find_lockowner(host, fl->fl_owner);
+	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;
 }
diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
index 1bddf70d9656..e4d3f783e06a 100644
--- a/fs/lockd/svc4proc.c
+++ b/fs/lockd/svc4proc.c
@@ -46,8 +46,14 @@ nlm4svc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
 
 		/* Set up the missing parts of the file_lock structure */
 		lock->fl.fl_file  = file->f_file;
-		lock->fl.fl_owner = (fl_owner_t) host;
+		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;
@@ -94,6 +100,7 @@ __nlm4svc_proc_test(struct svc_rqst *rqstp, struct nlm_res *resp)
 	else
 		dprintk("lockd: TEST4        status %d\n", ntohl(resp->status));
 
+	nlmsvc_release_lockowner(&argp->lock);
 	nlmsvc_release_host(host);
 	nlm_release_file(file);
 	return rc;
@@ -142,6 +149,7 @@ __nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_res *resp)
 	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;
@@ -178,6 +186,7 @@ __nlm4svc_proc_cancel(struct svc_rqst *rqstp, struct nlm_res *resp)
 	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;
@@ -217,6 +226,7 @@ __nlm4svc_proc_unlock(struct svc_rqst *rqstp, struct nlm_res *resp)
 	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;
@@ -365,6 +375,7 @@ nlm4svc_proc_share(struct svc_rqst *rqstp)
 	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;
@@ -399,6 +410,7 @@ nlm4svc_proc_unshare(struct svc_rqst *rqstp)
 	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;
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index ea719cdd6a36..61d3cc2283dc 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -332,6 +332,93 @@ restart:
 	mutex_unlock(&file->f_mutex);
 }
 
+static struct nlm_lockowner *
+nlmsvc_get_lockowner(struct nlm_lockowner *lockowner)
+{
+	refcount_inc(&lockowner->count);
+	return lockowner;
+}
+
+static 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);
+}
+
+static void nlmsvc_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
+{
+	struct nlm_lockowner *nlm_lo = (struct nlm_lockowner *)fl->fl_owner;
+	new->fl_owner = nlmsvc_get_lockowner(nlm_lo);
+}
+
+static void nlmsvc_locks_release_private(struct file_lock *fl)
+{
+	nlmsvc_put_lockowner((struct nlm_lockowner *)fl->fl_owner);
+}
+
+static const struct file_lock_operations nlmsvc_lock_ops = {
+	.fl_copy_lock = nlmsvc_locks_copy_lock,
+	.fl_release_private = nlmsvc_locks_release_private,
+};
+
+void nlmsvc_locks_init_private(struct file_lock *fl, struct nlm_host *host,
+						pid_t pid)
+{
+	fl->fl_owner = nlmsvc_find_lockowner(host, pid);
+	if (fl->fl_owner != NULL)
+		fl->fl_ops = &nlmsvc_lock_ops;
+}
+
 /*
  * Initialize arguments for GRANTED call. The nlm_rqst structure
  * has been cleared already.
@@ -345,7 +432,7 @@ static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
 
 	/* set default data area */
 	call->a_args.lock.oh.data = call->a_owner;
-	call->a_args.lock.svid = lock->fl.fl_pid;
+	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);
@@ -509,6 +596,7 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
 {
 	int			error;
 	__be32			ret;
+	struct nlm_lockowner	*test_owner;
 
 	dprintk("lockd: nlmsvc_testlock(%s/%ld, ty=%d, %Ld-%Ld)\n",
 				locks_inode(file->f_file)->i_sb->s_id,
@@ -522,6 +610,9 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
 		goto out;
 	}
 
+	/* If there's a conflicting lock, remember to clean up the test lock */
+	test_owner = (struct nlm_lockowner *)lock->fl.fl_owner;
+
 	error = vfs_test_lock(file->f_file, &lock->fl);
 	if (error) {
 		/* We can't currently deal with deferred test requests */
@@ -543,11 +634,16 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
 	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->svid = ((struct nlm_lockowner *)lock->fl.fl_owner)->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);
+
+	/* Clean up the test lock */
+	lock->fl.fl_owner = NULL;
+	nlmsvc_put_lockowner(test_owner);
+
 	ret = nlm_lck_denied;
 out:
 	return ret;
@@ -692,25 +788,7 @@ nlmsvc_notify_blocked(struct file_lock *fl)
 	printk(KERN_WARNING "lockd: notification for unknown block!\n");
 }
 
-static int nlmsvc_same_owner(struct file_lock *fl1, struct file_lock *fl2)
-{
-	return fl1->fl_owner == fl2->fl_owner && fl1->fl_pid == fl2->fl_pid;
-}
-
-/*
- * Since NLM uses two "keys" for tracking locks, we need to hash them down
- * to one for the blocked_hash. Here, we're just xor'ing the host address
- * with the pid in order to create a key value for picking a hash bucket.
- */
-static unsigned long
-nlmsvc_owner_key(struct file_lock *fl)
-{
-	return (unsigned long)fl->fl_owner ^ (unsigned long)fl->fl_pid;
-}
-
 const struct lock_manager_operations nlmsvc_lock_operations = {
-	.lm_compare_owner = nlmsvc_same_owner,
-	.lm_owner_key = nlmsvc_owner_key,
 	.lm_notify = nlmsvc_notify_blocked,
 	.lm_grant = nlmsvc_grant_deferred,
 };
diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
index ea77c66d3cc3..d0bb7a6bf005 100644
--- a/fs/lockd/svcproc.c
+++ b/fs/lockd/svcproc.c
@@ -76,8 +76,14 @@ nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
 
 		/* Set up the missing parts of the file_lock structure */
 		lock->fl.fl_file  = file->f_file;
-		lock->fl.fl_owner = (fl_owner_t) host;
+		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;
@@ -125,6 +131,7 @@ __nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_res *resp)
 		dprintk("lockd: TEST          status %d vers %d\n",
 			ntohl(resp->status), rqstp->rq_vers);
 
+	nlmsvc_release_lockowner(&argp->lock);
 	nlmsvc_release_host(host);
 	nlm_release_file(file);
 	return rc;
@@ -173,6 +180,7 @@ __nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_res *resp)
 	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;
@@ -210,6 +218,7 @@ __nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_res *resp)
 	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;
@@ -250,6 +259,7 @@ __nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_res *resp)
 	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;
@@ -408,6 +418,7 @@ nlmsvc_proc_share(struct svc_rqst *rqstp)
 	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;
@@ -442,6 +453,7 @@ nlmsvc_proc_unshare(struct svc_rqst *rqstp)
 	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;
diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c
index 0e610f422406..028fc152da22 100644
--- a/fs/lockd/svcsubs.c
+++ b/fs/lockd/svcsubs.c
@@ -180,7 +180,7 @@ again:
 		/* update current lock count */
 		file->f_locks++;
 
-		lockhost = (struct nlm_host *) fl->fl_owner;
+		lockhost = ((struct nlm_lockowner *)fl->fl_owner)->host;
 		if (match(lockhost, host)) {
 			struct file_lock lock = *fl;
 
diff --git a/fs/lockd/xdr.c b/fs/lockd/xdr.c
index 7147e4aebecc..982629f7b120 100644
--- a/fs/lockd/xdr.c
+++ b/fs/lockd/xdr.c
@@ -126,8 +126,6 @@ nlm_decode_lock(__be32 *p, struct nlm_lock *lock)
 	lock->svid  = ntohl(*p++);
 
 	locks_init_lock(fl);
-	fl->fl_owner = current->files;
-	fl->fl_pid   = (pid_t)lock->svid;
 	fl->fl_flags = FL_POSIX;
 	fl->fl_type  = F_RDLCK;		/* as good as anything else */
 	start = ntohl(*p++);
@@ -269,7 +267,6 @@ nlmsvc_decode_shareargs(struct svc_rqst *rqstp, __be32 *p)
 	memset(lock, 0, sizeof(*lock));
 	locks_init_lock(&lock->fl);
 	lock->svid = ~(u32) 0;
-	lock->fl.fl_pid = (pid_t)lock->svid;
 
 	if (!(p = nlm_decode_cookie(p, &argp->cookie))
 	 || !(p = xdr_decode_string_inplace(p, &lock->caller,
diff --git a/fs/lockd/xdr4.c b/fs/lockd/xdr4.c
index 7ed9edf9aed4..5fa9f48a9dba 100644
--- a/fs/lockd/xdr4.c
+++ b/fs/lockd/xdr4.c
@@ -118,8 +118,6 @@ nlm4_decode_lock(__be32 *p, struct nlm_lock *lock)
 	lock->svid  = ntohl(*p++);
 
 	locks_init_lock(fl);
-	fl->fl_owner = current->files;
-	fl->fl_pid   = (pid_t)lock->svid;
 	fl->fl_flags = FL_POSIX;
 	fl->fl_type  = F_RDLCK;		/* as good as anything else */
 	p = xdr_decode_hyper(p, &start);
@@ -266,7 +264,6 @@ nlm4svc_decode_shareargs(struct svc_rqst *rqstp, __be32 *p)
 	memset(lock, 0, sizeof(*lock));
 	locks_init_lock(&lock->fl);
 	lock->svid = ~(u32) 0;
-	lock->fl.fl_pid = (pid_t)lock->svid;
 
 	if (!(p = nlm4_decode_cookie(p, &argp->cookie))
 	 || !(p = xdr_decode_string_inplace(p, &lock->caller,
diff --git a/fs/locks.c b/fs/locks.c
index de87a3231789..686eae21daf6 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -658,9 +658,6 @@ static inline int locks_overlap(struct file_lock *fl1, struct file_lock *fl2)
  */
 static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2)
 {
-	if (fl1->fl_lmops && fl1->fl_lmops->lm_compare_owner)
-		return fl2->fl_lmops == fl1->fl_lmops &&
-			fl1->fl_lmops->lm_compare_owner(fl1, fl2);
 	return fl1->fl_owner == fl2->fl_owner;
 }
 
@@ -701,8 +698,6 @@ static void locks_delete_global_locks(struct file_lock *fl)
 static unsigned long
 posix_owner_key(struct file_lock *fl)
 {
-	if (fl->fl_lmops && fl->fl_lmops->lm_owner_key)
-		return fl->fl_lmops->lm_owner_key(fl);
 	return (unsigned long)fl->fl_owner;
 }
 
diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c
index 4fb1f72a25fb..66d4c55eb48e 100644
--- a/fs/nfsd/blocklayout.c
+++ b/fs/nfsd/blocklayout.c
@@ -121,15 +121,13 @@ nfsd4_block_commit_blocks(struct inode *inode, struct nfsd4_layoutcommit *lcp,
 {
 	loff_t new_size = lcp->lc_last_wr + 1;
 	struct iattr iattr = { .ia_valid = 0 };
-	struct timespec ts;
 	int error;
 
-	ts = timespec64_to_timespec(inode->i_mtime);
 	if (lcp->lc_mtime.tv_nsec == UTIME_NOW ||
-	    timespec_compare(&lcp->lc_mtime, &ts) < 0)
-		lcp->lc_mtime = timespec64_to_timespec(current_time(inode));
+	    timespec64_compare(&lcp->lc_mtime, &inode->i_mtime) < 0)
+		lcp->lc_mtime = current_time(inode);
 	iattr.ia_valid |= ATTR_ATIME | ATTR_CTIME | ATTR_MTIME;
-	iattr.ia_atime = iattr.ia_ctime = iattr.ia_mtime = timespec_to_timespec64(lcp->lc_mtime);
+	iattr.ia_atime = iattr.ia_ctime = iattr.ia_mtime = lcp->lc_mtime;
 
 	if (new_size > i_size_read(inode)) {
 		iattr.ia_valid |= ATTR_SIZE;
diff --git a/fs/nfsd/cache.h b/fs/nfsd/cache.h
index 4a98537efb0f..10ec5ecdf117 100644
--- a/fs/nfsd/cache.h
+++ b/fs/nfsd/cache.h
@@ -10,6 +10,7 @@
 #define NFSCACHE_H
 
 #include <linux/sunrpc/svc.h>
+#include "netns.h"
 
 /*
  * Representation of a reply cache entry.
@@ -77,8 +78,8 @@ enum {
 /* Checksum this amount of the request */
 #define RC_CSUMLEN		(256U)
 
-int	nfsd_reply_cache_init(void);
-void	nfsd_reply_cache_shutdown(void);
+int	nfsd_reply_cache_init(struct nfsd_net *);
+void	nfsd_reply_cache_shutdown(struct nfsd_net *);
 int	nfsd_cache_lookup(struct svc_rqst *);
 void	nfsd_cache_update(struct svc_rqst *, int, __be32 *);
 int	nfsd_reply_cache_stats_open(struct inode *, struct file *);
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index 7c686a270d60..bdfe5bcb3dcd 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -42,6 +42,11 @@ struct nfsd_net {
 	bool grace_ended;
 	time_t boot_time;
 
+	/* internal mount of the "nfsd" pseudofilesystem: */
+	struct vfsmount *nfsd_mnt;
+
+	struct dentry *nfsd_client_dir;
+
 	/*
 	 * reclaim_str_hashtbl[] holds known client info from previous reset/reboot
 	 * used in reboot/reset lease grace period processing
@@ -106,6 +111,7 @@ struct nfsd_net {
 	 */
 	unsigned int max_connections;
 
+	u32 clientid_base;
 	u32 clientid_counter;
 	u32 clverifier_counter;
 
@@ -127,6 +133,44 @@ struct nfsd_net {
 	 */
 	bool *nfsd_versions;
 	bool *nfsd4_minorversions;
+
+	/*
+	 * Duplicate reply cache
+	 */
+	struct nfsd_drc_bucket   *drc_hashtbl;
+	struct kmem_cache        *drc_slab;
+
+	/* max number of entries allowed in the cache */
+	unsigned int             max_drc_entries;
+
+	/* number of significant bits in the hash value */
+	unsigned int             maskbits;
+	unsigned int             drc_hashsize;
+
+	/*
+	 * Stats and other tracking of on the duplicate reply cache.
+	 * These fields and the "rc" fields in nfsdstats are modified
+	 * with only the per-bucket cache lock, which isn't really safe
+	 * and should be fixed if we want the statistics to be
+	 * completely accurate.
+	 */
+
+	/* total number of entries */
+	atomic_t                 num_drc_entries;
+
+	/* cache misses due only to checksum comparison failures */
+	unsigned int             payload_misses;
+
+	/* amount of memory (in bytes) currently consumed by the DRC */
+	unsigned int             drc_mem_usage;
+
+	/* longest hash chain seen */
+	unsigned int             longest_chain;
+
+	/* size of cache when we saw the longest hash chain */
+	unsigned int             longest_chain_cachesize;
+
+	struct shrinker		nfsd_reply_cache_shrinker;
 };
 
 /* Simple check to find out if a given net was properly initialized */
diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
index 2961016097ac..d1f285245af8 100644
--- a/fs/nfsd/nfs4idmap.c
+++ b/fs/nfsd/nfs4idmap.c
@@ -83,7 +83,7 @@ ent_init(struct cache_head *cnew, struct cache_head *citm)
 	new->type = itm->type;
 
 	strlcpy(new->name, itm->name, sizeof(new->name));
-	strlcpy(new->authname, itm->authname, sizeof(new->name));
+	strlcpy(new->authname, itm->authname, sizeof(new->authname));
 }
 
 static void
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 1a0cdeb3b875..7857942c5ca6 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -42,6 +42,7 @@
 #include <linux/sunrpc/svcauth_gss.h>
 #include <linux/sunrpc/addr.h>
 #include <linux/jhash.h>
+#include <linux/string_helpers.h>
 #include "xdr4.h"
 #include "xdr4cb.h"
 #include "vfs.h"
@@ -99,6 +100,13 @@ enum nfsd4_st_mutex_lock_subclass {
  */
 static DECLARE_WAIT_QUEUE_HEAD(close_wq);
 
+/*
+ * A waitqueue where a writer to clients/#/ctl destroying a client can
+ * wait for cl_rpc_users to drop to 0 and then for the client to be
+ * unhashed.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(expiry_wq);
+
 static struct kmem_cache *client_slab;
 static struct kmem_cache *openowner_slab;
 static struct kmem_cache *lockowner_slab;
@@ -138,7 +146,7 @@ static __be32 get_client_locked(struct nfs4_client *clp)
 
 	if (is_client_expired(clp))
 		return nfserr_expired;
-	atomic_inc(&clp->cl_refcount);
+	atomic_inc(&clp->cl_rpc_users);
 	return nfs_ok;
 }
 
@@ -170,20 +178,24 @@ static void put_client_renew_locked(struct nfs4_client *clp)
 
 	lockdep_assert_held(&nn->client_lock);
 
-	if (!atomic_dec_and_test(&clp->cl_refcount))
+	if (!atomic_dec_and_test(&clp->cl_rpc_users))
 		return;
 	if (!is_client_expired(clp))
 		renew_client_locked(clp);
+	else
+		wake_up_all(&expiry_wq);
 }
 
 static void put_client_renew(struct nfs4_client *clp)
 {
 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 
-	if (!atomic_dec_and_lock(&clp->cl_refcount, &nn->client_lock))
+	if (!atomic_dec_and_lock(&clp->cl_rpc_users, &nn->client_lock))
 		return;
 	if (!is_client_expired(clp))
 		renew_client_locked(clp);
+	else
+		wake_up_all(&expiry_wq);
 	spin_unlock(&nn->client_lock);
 }
 
@@ -694,7 +706,8 @@ struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *sla
 
 	idr_preload(GFP_KERNEL);
 	spin_lock(&cl->cl_lock);
-	new_id = idr_alloc_cyclic(&cl->cl_stateids, stid, 0, 0, GFP_NOWAIT);
+	/* Reserving 0 for start of file in nfsdfs "states" file: */
+	new_id = idr_alloc_cyclic(&cl->cl_stateids, stid, 1, 0, GFP_NOWAIT);
 	spin_unlock(&cl->cl_lock);
 	idr_preload_end();
 	if (new_id < 0)
@@ -1844,7 +1857,7 @@ static struct nfs4_client *alloc_client(struct xdr_netobj name)
 	clp = kmem_cache_zalloc(client_slab, GFP_KERNEL);
 	if (clp == NULL)
 		return NULL;
-	clp->cl_name.data = kmemdup(name.data, name.len, GFP_KERNEL);
+	xdr_netobj_dup(&clp->cl_name, &name, GFP_KERNEL);
 	if (clp->cl_name.data == NULL)
 		goto err_no_name;
 	clp->cl_ownerstr_hashtbl = kmalloc_array(OWNER_HASH_SIZE,
@@ -1854,10 +1867,9 @@ static struct nfs4_client *alloc_client(struct xdr_netobj name)
 		goto err_no_hashtbl;
 	for (i = 0; i < OWNER_HASH_SIZE; i++)
 		INIT_LIST_HEAD(&clp->cl_ownerstr_hashtbl[i]);
-	clp->cl_name.len = name.len;
 	INIT_LIST_HEAD(&clp->cl_sessions);
 	idr_init(&clp->cl_stateids);
-	atomic_set(&clp->cl_refcount, 0);
+	atomic_set(&clp->cl_rpc_users, 0);
 	clp->cl_cb_state = NFSD4_CB_UNKNOWN;
 	INIT_LIST_HEAD(&clp->cl_idhash);
 	INIT_LIST_HEAD(&clp->cl_openowners);
@@ -1879,6 +1891,25 @@ err_no_name:
 	return NULL;
 }
 
+static void __free_client(struct kref *k)
+{
+	struct nfsdfs_client *c = container_of(k, struct nfsdfs_client, cl_ref);
+	struct nfs4_client *clp = container_of(c, struct nfs4_client, cl_nfsdfs);
+
+	free_svc_cred(&clp->cl_cred);
+	kfree(clp->cl_ownerstr_hashtbl);
+	kfree(clp->cl_name.data);
+	kfree(clp->cl_nii_domain.data);
+	kfree(clp->cl_nii_name.data);
+	idr_destroy(&clp->cl_stateids);
+	kmem_cache_free(client_slab, clp);
+}
+
+static void drop_client(struct nfs4_client *clp)
+{
+	kref_put(&clp->cl_nfsdfs.cl_ref, __free_client);
+}
+
 static void
 free_client(struct nfs4_client *clp)
 {
@@ -1891,11 +1922,12 @@ free_client(struct nfs4_client *clp)
 		free_session(ses);
 	}
 	rpc_destroy_wait_queue(&clp->cl_cb_waitq);
-	free_svc_cred(&clp->cl_cred);
-	kfree(clp->cl_ownerstr_hashtbl);
-	kfree(clp->cl_name.data);
-	idr_destroy(&clp->cl_stateids);
-	kmem_cache_free(client_slab, clp);
+	if (clp->cl_nfsd_dentry) {
+		nfsd_client_rmdir(clp->cl_nfsd_dentry);
+		clp->cl_nfsd_dentry = NULL;
+		wake_up_all(&expiry_wq);
+	}
+	drop_client(clp);
 }
 
 /* must be called under the client_lock */
@@ -1936,7 +1968,7 @@ unhash_client(struct nfs4_client *clp)
 
 static __be32 mark_client_expired_locked(struct nfs4_client *clp)
 {
-	if (atomic_read(&clp->cl_refcount))
+	if (atomic_read(&clp->cl_rpc_users))
 		return nfserr_jukebox;
 	unhash_client_locked(clp);
 	return nfs_ok;
@@ -1989,6 +2021,7 @@ __destroy_client(struct nfs4_client *clp)
 	if (clp->cl_cb_conn.cb_xprt)
 		svc_xprt_put(clp->cl_cb_conn.cb_xprt);
 	free_client(clp);
+	wake_up_all(&expiry_wq);
 }
 
 static void
@@ -2199,6 +2232,342 @@ find_stateid_by_type(struct nfs4_client *cl, stateid_t *t, char typemask)
 	return s;
 }
 
+static struct nfs4_client *get_nfsdfs_clp(struct inode *inode)
+{
+	struct nfsdfs_client *nc;
+	nc = get_nfsdfs_client(inode);
+	if (!nc)
+		return NULL;
+	return container_of(nc, struct nfs4_client, cl_nfsdfs);
+}
+
+static void seq_quote_mem(struct seq_file *m, char *data, int len)
+{
+	seq_printf(m, "\"");
+	seq_escape_mem_ascii(m, data, len);
+	seq_printf(m, "\"");
+}
+
+static int client_info_show(struct seq_file *m, void *v)
+{
+	struct inode *inode = m->private;
+	struct nfs4_client *clp;
+	u64 clid;
+
+	clp = get_nfsdfs_clp(inode);
+	if (!clp)
+		return -ENXIO;
+	memcpy(&clid, &clp->cl_clientid, sizeof(clid));
+	seq_printf(m, "clientid: 0x%llx\n", clid);
+	seq_printf(m, "address: \"%pISpc\"\n", (struct sockaddr *)&clp->cl_addr);
+	seq_printf(m, "name: ");
+	seq_quote_mem(m, clp->cl_name.data, clp->cl_name.len);
+	seq_printf(m, "\nminor version: %d\n", clp->cl_minorversion);
+	if (clp->cl_nii_domain.data) {
+		seq_printf(m, "Implementation domain: ");
+		seq_quote_mem(m, clp->cl_nii_domain.data,
+					clp->cl_nii_domain.len);
+		seq_printf(m, "\nImplementation name: ");
+		seq_quote_mem(m, clp->cl_nii_name.data, clp->cl_nii_name.len);
+		seq_printf(m, "\nImplementation time: [%ld, %ld]\n",
+			clp->cl_nii_time.tv_sec, clp->cl_nii_time.tv_nsec);
+	}
+	drop_client(clp);
+
+	return 0;
+}
+
+static int client_info_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, client_info_show, inode);
+}
+
+static const struct file_operations client_info_fops = {
+	.open		= client_info_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static void *states_start(struct seq_file *s, loff_t *pos)
+	__acquires(&clp->cl_lock)
+{
+	struct nfs4_client *clp = s->private;
+	unsigned long id = *pos;
+	void *ret;
+
+	spin_lock(&clp->cl_lock);
+	ret = idr_get_next_ul(&clp->cl_stateids, &id);
+	*pos = id;