Merge tag 'nfsd-5.8' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Highlights:

   - Keep nfsd clients from unnecessarily breaking their own
     delegations.

     Note this requires a small kthreadd addition. The result is Tejun
     Heo's suggestion (see link), and he was OK with this going through
     my tree.

   - Patch nfsd/clients/ to display filenames, and to fix byte-order
     when displaying stateid's.

   - fix a module loading/unloading bug, from Neil Brown.

   - A big series from Chuck Lever with RPC/RDMA and tracing
     improvements, and lay some groundwork for RPC-over-TLS"

Link: https://lore.kernel.org/r/1588348912-24781-1-git-send-email-bfields@redhat.com

* tag 'nfsd-5.8' of git://linux-nfs.org/~bfields/linux: (49 commits)
  sunrpc: use kmemdup_nul() in gssp_stringify()
  nfsd: safer handling of corrupted c_type
  nfsd4: make drc_slab global, not per-net
  SUNRPC: Remove unreachable error condition in rpcb_getport_async()
  nfsd: Fix svc_xprt refcnt leak when setup callback client failed
  sunrpc: clean up properly in gss_mech_unregister()
  sunrpc: svcauth_gss_register_pseudoflavor must reject duplicate registrations.
  sunrpc: check that domain table is empty at module unload.
  NFSD: Fix improperly-formatted Doxygen comments
  NFSD: Squash an annoying compiler warning
  SUNRPC: Clean up request deferral tracepoints
  NFSD: Add tracepoints for monitoring NFSD callbacks
  NFSD: Add tracepoints to the NFSD state management code
  NFSD: Add tracepoints to NFSD's duplicate reply cache
  SUNRPC: svc_show_status() macro should have enum definitions
  SUNRPC: Restructure svc_udp_recvfrom()
  SUNRPC: Refactor svc_recvfrom()
  SUNRPC: Clean up svc_release_skb() functions
  SUNRPC: Refactor recvfrom path dealing with incomplete TCP receives
  SUNRPC: Replace dprintk() call sites in TCP receive path
  ...

Documentation/filesystems/locking.rst

@@ -429,6 +429,7 @@ prototypes::
 	int (*lm_grant)(struct file_lock *, struct file_lock *, int);
 	void (*lm_break)(struct file_lock *); /* break_lease callback */
 	int (*lm_change)(struct file_lock **, int);
+	bool (*lm_breaker_owns_lease)(struct file_lock *);
 
 locking rules:
 
@@ -439,6 +440,7 @@ lm_notify:		yes		yes			no
 lm_grant:		no		no			no
 lm_break:		yes		no			no
 lm_change		yes		no			no
+lm_breaker_owns_lease:	no		no			no
 ==========		=============	=================	=========
 
 buffer_head

fs/locks.c

@@ -1557,6 +1557,9 @@ static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker)
 {
 	bool rc;
 
+	if (lease->fl_lmops->lm_breaker_owns_lease
+			&& lease->fl_lmops->lm_breaker_owns_lease(lease))
+		return false;
 	if ((breaker->fl_flags & FL_LAYOUT) != (lease->fl_flags & FL_LAYOUT)) {
 		rc = false;
 		goto trace;

fs/nfsd/cache.h

@@ -78,6 +78,8 @@ enum {
 /* Checksum this amount of the request */
 #define RC_CSUMLEN		(256U)
 
+int	nfsd_drc_slab_create(void);
+void	nfsd_drc_slab_free(void);
 int	nfsd_reply_cache_init(struct nfsd_net *);
 void	nfsd_reply_cache_shutdown(struct nfsd_net *);
 int	nfsd_cache_lookup(struct svc_rqst *);

fs/nfsd/netns.h

@@ -139,7 +139,6 @@ struct nfsd_net {
 	 * 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;

fs/nfsd/nfs4callback.c

@@ -38,6 +38,7 @@
 #include "nfsd.h"
 #include "state.h"
 #include "netns.h"
+#include "trace.h"
 #include "xdr4cb.h"
 #include "xdr4.h"
 
@@ -904,16 +905,20 @@ static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *c
 
 	if (clp->cl_minorversion == 0) {
 		if (!clp->cl_cred.cr_principal &&
-				(clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
+		    (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
+			trace_nfsd_cb_setup_err(clp, -EINVAL);
 			return -EINVAL;
+		}
 		args.client_name = clp->cl_cred.cr_principal;
 		args.prognumber	= conn->cb_prog;
 		args.protocol = XPRT_TRANSPORT_TCP;
 		args.authflavor = clp->cl_cred.cr_flavor;
 		clp->cl_cb_ident = conn->cb_ident;
 	} else {
-		if (!conn->cb_xprt)
+		if (!conn->cb_xprt) {
+			trace_nfsd_cb_setup_err(clp, -EINVAL);
 			return -EINVAL;
+		}
 		clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
 		clp->cl_cb_session = ses;
 		args.bc_xprt = conn->cb_xprt;
@@ -925,50 +930,48 @@ static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *c
 	/* Create RPC client */
 	client = rpc_create(&args);
 	if (IS_ERR(client)) {
-		dprintk("NFSD: couldn't create callback client: %ld\n",
-			PTR_ERR(client));
+		trace_nfsd_cb_setup_err(clp, PTR_ERR(client));
 		return PTR_ERR(client);
 	}
 	cred = get_backchannel_cred(clp, client, ses);
 	if (!cred) {
+		trace_nfsd_cb_setup_err(clp, -ENOMEM);
 		rpc_shutdown_client(client);
 		return -ENOMEM;
 	}
 	clp->cl_cb_client = client;
 	clp->cl_cb_cred = cred;
+	trace_nfsd_cb_setup(clp);
 	return 0;
 }
 
-static void warn_no_callback_path(struct nfs4_client *clp, int reason)
-{
-	dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
-		(int)clp->cl_name.len, clp->cl_name.data, reason);
-}
-
 static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
 {
 	if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
 		return;
 	clp->cl_cb_state = NFSD4_CB_DOWN;
-	warn_no_callback_path(clp, reason);
+	trace_nfsd_cb_state(clp);
 }
 
 static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
 {
 	if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
 		return;
 	clp->cl_cb_state = NFSD4_CB_FAULT;
-	warn_no_callback_path(clp, reason);
+	trace_nfsd_cb_state(clp);
 }
 
 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
 {
 	struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
 
+	trace_nfsd_cb_done(clp, task->tk_status);
 	if (task->tk_status)
 		nfsd4_mark_cb_down(clp, task->tk_status);
-	else
+	else {
 		clp->cl_cb_state = NFSD4_CB_UP;
+		trace_nfsd_cb_state(clp);
+	}
 }
 
 static void nfsd4_cb_probe_release(void *calldata)
@@ -993,6 +996,7 @@ static const struct rpc_call_ops nfsd4_cb_probe_ops = {
 void nfsd4_probe_callback(struct nfs4_client *clp)
 {
 	clp->cl_cb_state = NFSD4_CB_UNKNOWN;
+	trace_nfsd_cb_state(clp);
 	set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
 	nfsd4_run_cb(&clp->cl_cb_null);
 }
@@ -1009,6 +1013,7 @@ void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
 	spin_lock(&clp->cl_lock);
 	memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
 	spin_unlock(&clp->cl_lock);
+	trace_nfsd_cb_state(clp);
 }
 
 /*
@@ -1165,8 +1170,7 @@ static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
 	struct nfsd4_callback *cb = calldata;
 	struct nfs4_client *clp = cb->cb_clp;
 
-	dprintk("%s: minorversion=%d\n", __func__,
-		clp->cl_minorversion);
+	trace_nfsd_cb_done(clp, task->tk_status);
 
 	if (!nfsd4_cb_sequence_done(task, cb))
 		return;
@@ -1271,6 +1275,7 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
 	 * kill the old client:
 	 */
 	if (clp->cl_cb_client) {
+		trace_nfsd_cb_shutdown(clp);
 		rpc_shutdown_client(clp->cl_cb_client);
 		clp->cl_cb_client = NULL;
 		put_cred(clp->cl_cb_cred);
@@ -1301,6 +1306,8 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
 	err = setup_callback_client(clp, &conn, ses);
 	if (err) {
 		nfsd4_mark_cb_down(clp, err);
+		if (c)
+			svc_xprt_put(c->cn_xprt);
 		return;
 	}
 }
@@ -1314,6 +1321,8 @@ nfsd4_run_cb_work(struct work_struct *work)
 	struct rpc_clnt *clnt;
 	int flags;
 
+	trace_nfsd_cb_work(clp, cb->cb_msg.rpc_proc->p_name);
+
 	if (cb->cb_need_restart) {
 		cb->cb_need_restart = false;
 	} else {

fs/nfsd/nfs4proc.c

@@ -1155,7 +1155,7 @@ extern void nfs_sb_deactive(struct super_block *sb);
 
 #define NFSD42_INTERSSC_MOUNTOPS "vers=4.2,addr=%s,sec=sys"
 
-/**
+/*
  * Support one copy source server for now.
  */
 static __be32
@@ -1245,10 +1245,9 @@ nfsd4_interssc_disconnect(struct vfsmount *ss_mnt)
 	mntput(ss_mnt);
 }
 
-/**
- * nfsd4_setup_inter_ssc
- *
+/*
  * Verify COPY destination stateid.
+ *
  * Connect to the source server with NFSv4.1.
  * Create the source struct file for nfsd_copy_range.
  * Called with COPY cstate:
@@ -2302,6 +2301,8 @@ nfsd4_proc_compound(struct svc_rqst *rqstp)
 	}
 	check_if_stalefh_allowed(args);
 
+	rqstp->rq_lease_breaker = (void **)&cstate->clp;
+
 	trace_nfsd_compound(rqstp, args->opcnt);
 	while (!status && resp->opcnt < args->opcnt) {
 		op = &args->ops[resp->opcnt++];