1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 */
6#include <linux/module.h>
7#include <linux/nfs_fs.h>
8#include <linux/nfs_mount.h>
9#include <linux/sunrpc/addr.h>
10#include <linux/sunrpc/auth.h>
11#include <linux/sunrpc/xprt.h>
12#include <linux/sunrpc/bc_xprt.h>
13#include <linux/sunrpc/rpc_pipe_fs.h>
14#include "internal.h"
15#include "callback.h"
16#include "delegation.h"
17#include "nfs4session.h"
18#include "nfs4idmap.h"
19#include "pnfs.h"
20#include "netns.h"
21#include "sysfs.h"
22
23#define NFSDBG_FACILITY NFSDBG_CLIENT
24
25/*
26 * Get a unique NFSv4.0 callback identifier which will be used
27 * by the V4.0 callback service to lookup the nfs_client struct
28 */
29static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
30{
31 int ret = 0;
32 struct nfs_net *nn = net_generic(net: clp->cl_net, id: nfs_net_id);
33
34 if (clp->rpc_ops->version != 4 || minorversion != 0)
35 return ret;
36 idr_preload(GFP_KERNEL);
37 spin_lock(lock: &nn->nfs_client_lock);
38 ret = idr_alloc(&nn->cb_ident_idr, ptr: clp, start: 1, end: 0, GFP_NOWAIT);
39 if (ret >= 0)
40 clp->cl_cb_ident = ret;
41 spin_unlock(lock: &nn->nfs_client_lock);
42 idr_preload_end();
43 return ret < 0 ? ret : 0;
44}
45
46#ifdef CONFIG_NFS_V4_1
47/*
48 * Per auth flavor data server rpc clients
49 */
50struct nfs4_ds_server {
51 struct list_head list; /* ds_clp->cl_ds_clients */
52 struct rpc_clnt *rpc_clnt;
53};
54
55/**
56 * nfs4_find_ds_client - Common lookup case for DS I/O
57 * @ds_clp: pointer to the DS's nfs_client
58 * @flavor: rpc auth flavour to match
59 */
60static struct nfs4_ds_server *
61nfs4_find_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
62{
63 struct nfs4_ds_server *dss;
64
65 rcu_read_lock();
66 list_for_each_entry_rcu(dss, &ds_clp->cl_ds_clients, list) {
67 if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
68 continue;
69 goto out;
70 }
71 dss = NULL;
72out:
73 rcu_read_unlock();
74 return dss;
75}
76
77static struct nfs4_ds_server *
78nfs4_add_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor,
79 struct nfs4_ds_server *new)
80{
81 struct nfs4_ds_server *dss;
82
83 spin_lock(lock: &ds_clp->cl_lock);
84 list_for_each_entry(dss, &ds_clp->cl_ds_clients, list) {
85 if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
86 continue;
87 goto out;
88 }
89 if (new)
90 list_add_rcu(new: &new->list, head: &ds_clp->cl_ds_clients);
91 dss = new;
92out:
93 spin_unlock(lock: &ds_clp->cl_lock); /* need some lock to protect list */
94 return dss;
95}
96
97static struct nfs4_ds_server *
98nfs4_alloc_ds_server(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
99{
100 struct nfs4_ds_server *dss;
101
102 dss = kmalloc(size: sizeof(*dss), GFP_NOFS);
103 if (dss == NULL)
104 return ERR_PTR(error: -ENOMEM);
105
106 dss->rpc_clnt = rpc_clone_client_set_auth(ds_clp->cl_rpcclient, flavor);
107 if (IS_ERR(ptr: dss->rpc_clnt)) {
108 int err = PTR_ERR(ptr: dss->rpc_clnt);
109 kfree (objp: dss);
110 return ERR_PTR(error: err);
111 }
112 INIT_LIST_HEAD(list: &dss->list);
113
114 return dss;
115}
116
117static void
118nfs4_free_ds_server(struct nfs4_ds_server *dss)
119{
120 rpc_release_client(dss->rpc_clnt);
121 kfree(objp: dss);
122}
123
124/**
125 * nfs4_find_or_create_ds_client - Find or create a DS rpc client
126 * @ds_clp: pointer to the DS's nfs_client
127 * @inode: pointer to the inode
128 *
129 * Find or create a DS rpc client with th MDS server rpc client auth flavor
130 * in the nfs_client cl_ds_clients list.
131 */
132struct rpc_clnt *
133nfs4_find_or_create_ds_client(struct nfs_client *ds_clp, struct inode *inode)
134{
135 struct nfs4_ds_server *dss, *new;
136 rpc_authflavor_t flavor = NFS_SERVER(inode)->client->cl_auth->au_flavor;
137
138 dss = nfs4_find_ds_client(ds_clp, flavor);
139 if (dss != NULL)
140 goto out;
141 new = nfs4_alloc_ds_server(ds_clp, flavor);
142 if (IS_ERR(ptr: new))
143 return ERR_CAST(ptr: new);
144 dss = nfs4_add_ds_client(ds_clp, flavor, new);
145 if (dss != new)
146 nfs4_free_ds_server(dss: new);
147out:
148 return dss->rpc_clnt;
149}
150EXPORT_SYMBOL_GPL(nfs4_find_or_create_ds_client);
151
152static void
153nfs4_shutdown_ds_clients(struct nfs_client *clp)
154{
155 struct nfs4_ds_server *dss;
156
157 while (!list_empty(head: &clp->cl_ds_clients)) {
158 dss = list_entry(clp->cl_ds_clients.next,
159 struct nfs4_ds_server, list);
160 list_del(entry: &dss->list);
161 rpc_shutdown_client(dss->rpc_clnt);
162 kfree (objp: dss);
163 }
164}
165
166static void
167nfs4_cleanup_callback(struct nfs_client *clp)
168{
169 struct nfs4_copy_state *cp_state;
170
171 while (!list_empty(head: &clp->pending_cb_stateids)) {
172 cp_state = list_entry(clp->pending_cb_stateids.next,
173 struct nfs4_copy_state, copies);
174 list_del(entry: &cp_state->copies);
175 kfree(objp: cp_state);
176 }
177}
178
179void nfs41_shutdown_client(struct nfs_client *clp)
180{
181 if (nfs4_has_session(clp)) {
182 nfs4_cleanup_callback(clp);
183 nfs4_shutdown_ds_clients(clp);
184 nfs4_destroy_session(session: clp->cl_session);
185 nfs4_destroy_clientid(clp);
186 }
187
188}
189#endif /* CONFIG_NFS_V4_1 */
190
191void nfs40_shutdown_client(struct nfs_client *clp)
192{
193 if (clp->cl_slot_tbl) {
194 nfs4_shutdown_slot_table(tbl: clp->cl_slot_tbl);
195 kfree(objp: clp->cl_slot_tbl);
196 }
197}
198
199struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
200{
201 char buf[INET6_ADDRSTRLEN + 1];
202 const char *ip_addr = cl_init->ip_addr;
203 struct nfs_client *clp = nfs_alloc_client(cl_init);
204 int err;
205
206 if (IS_ERR(ptr: clp))
207 return clp;
208
209 err = nfs_get_cb_ident_idr(clp, minorversion: cl_init->minorversion);
210 if (err)
211 goto error;
212
213 if (cl_init->minorversion > NFS4_MAX_MINOR_VERSION) {
214 err = -EINVAL;
215 goto error;
216 }
217
218 spin_lock_init(&clp->cl_lock);
219 INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
220 INIT_LIST_HEAD(list: &clp->cl_ds_clients);
221 rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
222 clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
223 clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
224 clp->cl_mig_gen = 1;
225#if IS_ENABLED(CONFIG_NFS_V4_1)
226 init_waitqueue_head(&clp->cl_lock_waitq);
227#endif
228 INIT_LIST_HEAD(list: &clp->pending_cb_stateids);
229
230 if (cl_init->minorversion != 0)
231 __set_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags);
232 __set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
233 __set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags);
234
235 if (test_bit(NFS_CS_DS, &cl_init->init_flags))
236 __set_bit(NFS_CS_DS, &clp->cl_flags);
237 /*
238 * Set up the connection to the server before we add add to the
239 * global list.
240 */
241 err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_GSS_KRB5I);
242 if (err == -EINVAL)
243 err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
244 if (err < 0)
245 goto error;
246
247 /* If no clientaddr= option was specified, find a usable cb address */
248 if (ip_addr == NULL) {
249 struct sockaddr_storage cb_addr;
250 struct sockaddr *sap = (struct sockaddr *)&cb_addr;
251
252 err = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
253 if (err < 0)
254 goto error;
255 err = rpc_ntop(sap, buf, sizeof(buf));
256 if (err < 0)
257 goto error;
258 ip_addr = (const char *)buf;
259 }
260 strscpy(p: clp->cl_ipaddr, q: ip_addr, size: sizeof(clp->cl_ipaddr));
261
262 err = nfs_idmap_new(clp);
263 if (err < 0) {
264 dprintk("%s: failed to create idmapper. Error = %d\n",
265 __func__, err);
266 goto error;
267 }
268 __set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
269 return clp;
270
271error:
272 nfs_free_client(clp);
273 return ERR_PTR(error: err);
274}
275
276/*
277 * Destroy the NFS4 callback service
278 */
279static void nfs4_destroy_callback(struct nfs_client *clp)
280{
281 if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
282 nfs_callback_down(minorversion: clp->cl_mvops->minor_version, net: clp->cl_net);
283}
284
285static void nfs4_shutdown_client(struct nfs_client *clp)
286{
287 if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
288 nfs4_kill_renewd(clp);
289 clp->cl_mvops->shutdown_client(clp);
290 nfs4_destroy_callback(clp);
291 if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
292 nfs_idmap_delete(clp);
293
294 rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
295 kfree(objp: clp->cl_serverowner);
296 kfree(objp: clp->cl_serverscope);
297 kfree(objp: clp->cl_implid);
298 kfree(objp: clp->cl_owner_id);
299}
300
301void nfs4_free_client(struct nfs_client *clp)
302{
303 nfs4_shutdown_client(clp);
304 nfs_free_client(clp);
305}
306
307/*
308 * Initialize the NFS4 callback service
309 */
310static int nfs4_init_callback(struct nfs_client *clp)
311{
312 struct rpc_xprt *xprt;
313 int error;
314
315 xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
316
317 if (nfs4_has_session(clp)) {
318 error = xprt_setup_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
319 if (error < 0)
320 return error;
321 }
322
323 error = nfs_callback_up(minorversion: clp->cl_mvops->minor_version, xprt);
324 if (error < 0) {
325 dprintk("%s: failed to start callback. Error = %d\n",
326 __func__, error);
327 return error;
328 }
329 __set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
330
331 return 0;
332}
333
334/**
335 * nfs40_init_client - nfs_client initialization tasks for NFSv4.0
336 * @clp: nfs_client to initialize
337 *
338 * Returns zero on success, or a negative errno if some error occurred.
339 */
340int nfs40_init_client(struct nfs_client *clp)
341{
342 struct nfs4_slot_table *tbl;
343 int ret;
344
345 tbl = kzalloc(size: sizeof(*tbl), GFP_NOFS);
346 if (tbl == NULL)
347 return -ENOMEM;
348
349 ret = nfs4_setup_slot_table(tbl, NFS4_MAX_SLOT_TABLE,
350 queue: "NFSv4.0 transport Slot table");
351 if (ret) {
352 nfs4_shutdown_slot_table(tbl);
353 kfree(objp: tbl);
354 return ret;
355 }
356
357 clp->cl_slot_tbl = tbl;
358 return 0;
359}
360
361#if defined(CONFIG_NFS_V4_1)
362
363/**
364 * nfs41_init_client - nfs_client initialization tasks for NFSv4.1+
365 * @clp: nfs_client to initialize
366 *
367 * Returns zero on success, or a negative errno if some error occurred.
368 */
369int nfs41_init_client(struct nfs_client *clp)
370{
371 struct nfs4_session *session = NULL;
372
373 /*
374 * Create the session and mark it expired.
375 * When a SEQUENCE operation encounters the expired session
376 * it will do session recovery to initialize it.
377 */
378 session = nfs4_alloc_session(clp);
379 if (!session)
380 return -ENOMEM;
381
382 clp->cl_session = session;
383
384 /*
385 * The create session reply races with the server back
386 * channel probe. Mark the client NFS_CS_SESSION_INITING
387 * so that the client back channel can find the
388 * nfs_client struct
389 */
390 nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
391 return 0;
392}
393
394#endif /* CONFIG_NFS_V4_1 */
395
396/*
397 * Initialize the minor version specific parts of an NFS4 client record
398 */
399static int nfs4_init_client_minor_version(struct nfs_client *clp)
400{
401 int ret;
402
403 ret = clp->cl_mvops->init_client(clp);
404 if (ret)
405 return ret;
406 return nfs4_init_callback(clp);
407}
408
409static void nfs4_add_trunk(struct nfs_client *clp, struct nfs_client *old)
410{
411 struct sockaddr_storage clp_addr, old_addr;
412 struct sockaddr *clp_sap = (struct sockaddr *)&clp_addr;
413 struct sockaddr *old_sap = (struct sockaddr *)&old_addr;
414 size_t clp_salen;
415 struct xprt_create xprt_args = {
416 .ident = old->cl_proto,
417 .net = old->cl_net,
418 .servername = old->cl_hostname,
419 };
420 int max_connect = test_bit(NFS_CS_PNFS, &clp->cl_flags) ?
421 clp->cl_max_connect : old->cl_max_connect;
422
423 if (clp->cl_proto != old->cl_proto)
424 return;
425 clp_salen = rpc_peeraddr(clp->cl_rpcclient, clp_sap, sizeof(clp_addr));
426 rpc_peeraddr(old->cl_rpcclient, old_sap, sizeof(old_addr));
427
428 if (clp_addr.ss_family != old_addr.ss_family)
429 return;
430
431 xprt_args.dstaddr = clp_sap;
432 xprt_args.addrlen = clp_salen;
433
434 rpc_clnt_add_xprt(old->cl_rpcclient, &xprt_args,
435 setup: rpc_clnt_test_and_add_xprt, data: &max_connect);
436}
437
438/**
439 * nfs4_init_client - Initialise an NFS4 client record
440 *
441 * @clp: nfs_client to initialise
442 * @cl_init: pointer to nfs_client_initdata
443 *
444 * Returns pointer to an NFS client, or an ERR_PTR value.
445 */
446struct nfs_client *nfs4_init_client(struct nfs_client *clp,
447 const struct nfs_client_initdata *cl_init)
448{
449 struct nfs_client *old;
450 int error;
451
452 if (clp->cl_cons_state == NFS_CS_READY)
453 /* the client is initialised already */
454 return clp;
455
456 error = nfs4_init_client_minor_version(clp);
457 if (error < 0)
458 goto error;
459
460 error = nfs4_discover_server_trunking(clp, &old);
461 if (error < 0)
462 goto error;
463
464 if (clp != old) {
465 clp->cl_preserve_clid = true;
466 /*
467 * Mark the client as having failed initialization so other
468 * processes walking the nfs_client_list in nfs_match_client()
469 * won't try to use it.
470 */
471 nfs_mark_client_ready(clp, state: -EPERM);
472 if (old->cl_mvops->session_trunk)
473 nfs4_add_trunk(clp, old);
474 }
475 clear_bit(NFS_CS_TSM_POSSIBLE, addr: &clp->cl_flags);
476 nfs_put_client(clp);
477 return old;
478
479error:
480 nfs_mark_client_ready(clp, state: error);
481 nfs_put_client(clp);
482 return ERR_PTR(error);
483}
484
485/*
486 * SETCLIENTID just did a callback update with the callback ident in
487 * "drop," but server trunking discovery claims "drop" and "keep" are
488 * actually the same server. Swap the callback IDs so that "keep"
489 * will continue to use the callback ident the server now knows about,
490 * and so that "keep"'s original callback ident is destroyed when
491 * "drop" is freed.
492 */
493static void nfs4_swap_callback_idents(struct nfs_client *keep,
494 struct nfs_client *drop)
495{
496 struct nfs_net *nn = net_generic(net: keep->cl_net, id: nfs_net_id);
497 unsigned int save = keep->cl_cb_ident;
498
499 if (keep->cl_cb_ident == drop->cl_cb_ident)
500 return;
501
502 dprintk("%s: keeping callback ident %u and dropping ident %u\n",
503 __func__, keep->cl_cb_ident, drop->cl_cb_ident);
504
505 spin_lock(lock: &nn->nfs_client_lock);
506
507 idr_replace(&nn->cb_ident_idr, keep, id: drop->cl_cb_ident);
508 keep->cl_cb_ident = drop->cl_cb_ident;
509
510 idr_replace(&nn->cb_ident_idr, drop, id: save);
511 drop->cl_cb_ident = save;
512
513 spin_unlock(lock: &nn->nfs_client_lock);
514}
515
516static bool nfs4_match_client_owner_id(const struct nfs_client *clp1,
517 const struct nfs_client *clp2)
518{
519 if (clp1->cl_owner_id == NULL || clp2->cl_owner_id == NULL)
520 return true;
521 return strcmp(clp1->cl_owner_id, clp2->cl_owner_id) == 0;
522}
523
524static bool nfs4_same_verifier(nfs4_verifier *v1, nfs4_verifier *v2)
525{
526 return memcmp(p: v1->data, q: v2->data, size: sizeof(v1->data)) == 0;
527}
528
529static int nfs4_match_client(struct nfs_client *pos, struct nfs_client *new,
530 struct nfs_client **prev, struct nfs_net *nn)
531{
532 int status;
533
534 if (pos->rpc_ops != new->rpc_ops)
535 return 1;
536
537 if (pos->cl_minorversion != new->cl_minorversion)
538 return 1;
539
540 /* If "pos" isn't marked ready, we can't trust the
541 * remaining fields in "pos", especially the client
542 * ID and serverowner fields. Wait for CREATE_SESSION
543 * to finish. */
544 if (pos->cl_cons_state > NFS_CS_READY) {
545 refcount_inc(r: &pos->cl_count);
546 spin_unlock(lock: &nn->nfs_client_lock);
547
548 nfs_put_client(*prev);
549 *prev = pos;
550
551 status = nfs_wait_client_init_complete(clp: pos);
552 spin_lock(lock: &nn->nfs_client_lock);
553
554 if (status < 0)
555 return status;
556 }
557
558 if (pos->cl_cons_state != NFS_CS_READY)
559 return 1;
560
561 if (pos->cl_clientid != new->cl_clientid)
562 return 1;
563
564 /* NFSv4.1 always uses the uniform string, however someone
565 * might switch the uniquifier string on us.
566 */
567 if (!nfs4_match_client_owner_id(clp1: pos, clp2: new))
568 return 1;
569
570 return 0;
571}
572
573/**
574 * nfs40_walk_client_list - Find server that recognizes a client ID
575 *
576 * @new: nfs_client with client ID to test
577 * @result: OUT: found nfs_client, or new
578 * @cred: credential to use for trunking test
579 *
580 * Returns zero, a negative errno, or a negative NFS4ERR status.
581 * If zero is returned, an nfs_client pointer is planted in "result."
582 *
583 * NB: nfs40_walk_client_list() relies on the new nfs_client being
584 * the last nfs_client on the list.
585 */
586int nfs40_walk_client_list(struct nfs_client *new,
587 struct nfs_client **result,
588 const struct cred *cred)
589{
590 struct nfs_net *nn = net_generic(net: new->cl_net, id: nfs_net_id);
591 struct nfs_client *pos, *prev = NULL;
592 struct nfs4_setclientid_res clid = {
593 .clientid = new->cl_clientid,
594 .confirm = new->cl_confirm,
595 };
596 int status = -NFS4ERR_STALE_CLIENTID;
597
598 spin_lock(lock: &nn->nfs_client_lock);
599 list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
600
601 if (pos == new)
602 goto found;
603
604 status = nfs4_match_client(pos, new, prev: &prev, nn);
605 if (status < 0)
606 goto out_unlock;
607 if (status != 0)
608 continue;
609 /*
610 * We just sent a new SETCLIENTID, which should have
611 * caused the server to return a new cl_confirm. So if
612 * cl_confirm is the same, then this is a different
613 * server that just returned the same cl_confirm by
614 * coincidence:
615 */
616 if ((new != pos) && nfs4_same_verifier(v1: &pos->cl_confirm,
617 v2: &new->cl_confirm))
618 continue;
619 /*
620 * But if the cl_confirm's are different, then the only
621 * way that a SETCLIENTID_CONFIRM to pos can succeed is
622 * if new and pos point to the same server:
623 */
624found:
625 refcount_inc(r: &pos->cl_count);
626 spin_unlock(lock: &nn->nfs_client_lock);
627
628 nfs_put_client(prev);
629 prev = pos;
630
631 status = nfs4_proc_setclientid_confirm(pos, arg: &clid, cred);
632 switch (status) {
633 case -NFS4ERR_STALE_CLIENTID:
634 break;
635 case 0:
636 nfs4_swap_callback_idents(keep: pos, drop: new);
637 pos->cl_confirm = new->cl_confirm;
638 nfs_mark_client_ready(clp: pos, NFS_CS_READY);
639
640 prev = NULL;
641 *result = pos;
642 goto out;
643 case -ERESTARTSYS:
644 case -ETIMEDOUT:
645 /* The callback path may have been inadvertently
646 * changed. Schedule recovery!
647 */
648 nfs4_schedule_path_down_recovery(clp: pos);
649 goto out;
650 default:
651 goto out;
652 }
653
654 spin_lock(lock: &nn->nfs_client_lock);
655 }
656out_unlock:
657 spin_unlock(lock: &nn->nfs_client_lock);
658
659 /* No match found. The server lost our clientid */
660out:
661 nfs_put_client(prev);
662 return status;
663}
664
665#ifdef CONFIG_NFS_V4_1
666/*
667 * Returns true if the server major ids match
668 */
669bool
670nfs4_check_serverowner_major_id(struct nfs41_server_owner *o1,
671 struct nfs41_server_owner *o2)
672{
673 if (o1->major_id_sz != o2->major_id_sz)
674 return false;
675 return memcmp(p: o1->major_id, q: o2->major_id, size: o1->major_id_sz) == 0;
676}
677
678/*
679 * Returns true if the server scopes match
680 */
681static bool
682nfs4_check_server_scope(struct nfs41_server_scope *s1,
683 struct nfs41_server_scope *s2)
684{
685 if (s1->server_scope_sz != s2->server_scope_sz)
686 return false;
687 return memcmp(p: s1->server_scope, q: s2->server_scope,
688 size: s1->server_scope_sz) == 0;
689}
690
691/**
692 * nfs4_detect_session_trunking - Checks for session trunking.
693 * @clp: original mount nfs_client
694 * @res: result structure from an exchange_id using the original mount
695 * nfs_client with a new multi_addr transport
696 * @xprt: pointer to the transport to add.
697 *
698 * Called after a successful EXCHANGE_ID on a multi-addr connection.
699 * Upon success, add the transport.
700 *
701 * Returns zero on success, otherwise -EINVAL
702 *
703 * Note: since the exchange_id for the new multi_addr transport uses the
704 * same nfs_client from the original mount, the cl_owner_id is reused,
705 * so eir_clientowner is the same.
706 */
707int nfs4_detect_session_trunking(struct nfs_client *clp,
708 struct nfs41_exchange_id_res *res,
709 struct rpc_xprt *xprt)
710{
711 /* Check eir_clientid */
712 if (clp->cl_clientid != res->clientid)
713 goto out_err;
714
715 /* Check eir_server_owner so_major_id */
716 if (!nfs4_check_serverowner_major_id(o1: clp->cl_serverowner,
717 o2: res->server_owner))
718 goto out_err;
719
720 /* Check eir_server_owner so_minor_id */
721 if (clp->cl_serverowner->minor_id != res->server_owner->minor_id)
722 goto out_err;
723
724 /* Check eir_server_scope */
725 if (!nfs4_check_server_scope(s1: clp->cl_serverscope, s2: res->server_scope))
726 goto out_err;
727
728 pr_info("NFS: %s: Session trunking succeeded for %s\n",
729 clp->cl_hostname,
730 xprt->address_strings[RPC_DISPLAY_ADDR]);
731
732 return 0;
733out_err:
734 pr_info("NFS: %s: Session trunking failed for %s\n", clp->cl_hostname,
735 xprt->address_strings[RPC_DISPLAY_ADDR]);
736
737 return -EINVAL;
738}
739
740/**
741 * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
742 *
743 * @new: nfs_client with client ID to test
744 * @result: OUT: found nfs_client, or new
745 * @cred: credential to use for trunking test
746 *
747 * Returns zero, a negative errno, or a negative NFS4ERR status.
748 * If zero is returned, an nfs_client pointer is planted in "result."
749 *
750 * NB: nfs41_walk_client_list() relies on the new nfs_client being
751 * the last nfs_client on the list.
752 */
753int nfs41_walk_client_list(struct nfs_client *new,
754 struct nfs_client **result,
755 const struct cred *cred)
756{
757 struct nfs_net *nn = net_generic(net: new->cl_net, id: nfs_net_id);
758 struct nfs_client *pos, *prev = NULL;
759 int status = -NFS4ERR_STALE_CLIENTID;
760
761 spin_lock(lock: &nn->nfs_client_lock);
762 list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
763
764 if (pos == new)
765 goto found;
766
767 status = nfs4_match_client(pos, new, prev: &prev, nn);
768 if (status < 0)
769 goto out;
770 if (status != 0)
771 continue;
772
773 /*
774 * Note that session trunking is just a special subcase of
775 * client id trunking. In either case, we want to fall back
776 * to using the existing nfs_client.
777 */
778 if (!nfs4_check_serverowner_major_id(o1: pos->cl_serverowner,
779 o2: new->cl_serverowner))
780 continue;
781
782found:
783 refcount_inc(r: &pos->cl_count);
784 *result = pos;
785 status = 0;
786 break;
787 }
788
789out:
790 spin_unlock(lock: &nn->nfs_client_lock);
791 nfs_put_client(prev);
792 return status;
793}
794#endif /* CONFIG_NFS_V4_1 */
795
796static void nfs4_destroy_server(struct nfs_server *server)
797{
798 LIST_HEAD(freeme);
799
800 nfs_server_return_all_delegations(server);
801 unset_pnfs_layoutdriver(server);
802 nfs4_purge_state_owners(server, &freeme);
803 nfs4_free_state_owners(head: &freeme);
804}
805
806/*
807 * NFSv4.0 callback thread helper
808 *
809 * Find a client by callback identifier
810 */
811struct nfs_client *
812nfs4_find_client_ident(struct net *net, int cb_ident)
813{
814 struct nfs_client *clp;
815 struct nfs_net *nn = net_generic(net, id: nfs_net_id);
816
817 spin_lock(lock: &nn->nfs_client_lock);
818 clp = idr_find(&nn->cb_ident_idr, id: cb_ident);
819 if (clp)
820 refcount_inc(r: &clp->cl_count);
821 spin_unlock(lock: &nn->nfs_client_lock);
822 return clp;
823}
824
825#if defined(CONFIG_NFS_V4_1)
826/* Common match routine for v4.0 and v4.1 callback services */
827static bool nfs4_cb_match_client(const struct sockaddr *addr,
828 struct nfs_client *clp, u32 minorversion)
829{
830 struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
831
832 /* Don't match clients that failed to initialise */
833 if (!(clp->cl_cons_state == NFS_CS_READY ||
834 clp->cl_cons_state == NFS_CS_SESSION_INITING))
835 return false;
836
837 smp_rmb();
838
839 /* Match the version and minorversion */
840 if (clp->rpc_ops->version != 4 ||
841 clp->cl_minorversion != minorversion)
842 return false;
843
844 /* Match only the IP address, not the port number */
845 return rpc_cmp_addr(sap1: addr, sap2: clap);
846}
847
848/*
849 * NFSv4.1 callback thread helper
850 * For CB_COMPOUND calls, find a client by IP address, protocol version,
851 * minorversion, and sessionID
852 *
853 * Returns NULL if no such client
854 */
855struct nfs_client *
856nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
857 struct nfs4_sessionid *sid, u32 minorversion)
858{
859 struct nfs_client *clp;
860 struct nfs_net *nn = net_generic(net, id: nfs_net_id);
861
862 spin_lock(lock: &nn->nfs_client_lock);
863 list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
864 if (!nfs4_cb_match_client(addr, clp, minorversion))
865 continue;
866
867 if (!nfs4_has_session(clp))
868 continue;
869
870 /* Match sessionid*/
871 if (memcmp(p: clp->cl_session->sess_id.data,
872 q: sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
873 continue;
874
875 refcount_inc(r: &clp->cl_count);
876 spin_unlock(lock: &nn->nfs_client_lock);
877 return clp;
878 }
879 spin_unlock(lock: &nn->nfs_client_lock);
880 return NULL;
881}
882
883#else /* CONFIG_NFS_V4_1 */
884
885struct nfs_client *
886nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
887 struct nfs4_sessionid *sid, u32 minorversion)
888{
889 return NULL;
890}
891#endif /* CONFIG_NFS_V4_1 */
892
893/*
894 * Set up an NFS4 client
895 */
896static int nfs4_set_client(struct nfs_server *server,
897 const char *hostname,
898 const struct sockaddr_storage *addr,
899 const size_t addrlen,
900 const char *ip_addr,
901 int proto, const struct rpc_timeout *timeparms,
902 u32 minorversion, unsigned int nconnect,
903 unsigned int max_connect,
904 struct net *net,
905 struct xprtsec_parms *xprtsec)
906{
907 struct nfs_client_initdata cl_init = {
908 .hostname = hostname,
909 .addr = addr,
910 .addrlen = addrlen,
911 .ip_addr = ip_addr,
912 .nfs_mod = &nfs_v4,
913 .proto = proto,
914 .minorversion = minorversion,
915 .net = net,
916 .timeparms = timeparms,
917 .cred = server->cred,
918 .xprtsec = *xprtsec,
919 };
920 struct nfs_client *clp;
921
922 if (minorversion == 0)
923 __set_bit(NFS_CS_REUSEPORT, &cl_init.init_flags);
924 else
925 cl_init.max_connect = max_connect;
926 switch (proto) {
927 case XPRT_TRANSPORT_TCP:
928 case XPRT_TRANSPORT_TCP_TLS:
929 cl_init.nconnect = nconnect;
930 }
931
932 if (server->flags & NFS_MOUNT_NORESVPORT)
933 __set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
934 if (server->options & NFS_OPTION_MIGRATION)
935 __set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
936 if (test_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status))
937 __set_bit(NFS_CS_TSM_POSSIBLE, &cl_init.init_flags);
938 server->port = rpc_get_port(sap: (struct sockaddr *)addr);
939
940 /* Allocate or find a client reference we can use */
941 clp = nfs_get_client(&cl_init);
942 if (IS_ERR(ptr: clp))
943 return PTR_ERR(ptr: clp);
944
945 if (server->nfs_client == clp) {
946 nfs_put_client(clp);
947 return -ELOOP;
948 }
949
950 /*
951 * Query for the lease time on clientid setup or renewal
952 *
953 * Note that this will be set on nfs_clients that were created
954 * only for the DS role and did not set this bit, but now will
955 * serve a dual role.
956 */
957 set_bit(NFS_CS_CHECK_LEASE_TIME, addr: &clp->cl_res_state);
958
959 server->nfs_client = clp;
960 nfs_sysfs_add_server(s: server);
961 nfs_sysfs_link_rpc_client(server, clnt: clp->cl_rpcclient, sysfs_prefix: "_state");
962
963 return 0;
964}
965
966/*
967 * Set up a pNFS Data Server client.
968 *
969 * Return any existing nfs_client that matches server address,port,version
970 * and minorversion.
971 *
972 * For a new nfs_client, use a soft mount (default), a low retrans and a
973 * low timeout interval so that if a connection is lost, we retry through
974 * the MDS.
975 */
976struct nfs_client *nfs4_set_ds_client(struct nfs_server *mds_srv,
977 const struct sockaddr_storage *ds_addr, int ds_addrlen,
978 int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans,
979 u32 minor_version)
980{
981 struct rpc_timeout ds_timeout;
982 struct nfs_client *mds_clp = mds_srv->nfs_client;
983 struct nfs_client_initdata cl_init = {
984 .addr = ds_addr,
985 .addrlen = ds_addrlen,
986 .nodename = mds_clp->cl_rpcclient->cl_nodename,
987 .ip_addr = mds_clp->cl_ipaddr,
988 .nfs_mod = &nfs_v4,
989 .proto = ds_proto,
990 .minorversion = minor_version,
991 .net = mds_clp->cl_net,
992 .timeparms = &ds_timeout,
993 .cred = mds_srv->cred,
994 .xprtsec = mds_srv->nfs_client->cl_xprtsec,
995 };
996 char buf[INET6_ADDRSTRLEN + 1];
997
998 if (rpc_ntop((struct sockaddr *)ds_addr, buf, sizeof(buf)) <= 0)
999 return ERR_PTR(error: -EINVAL);
1000 cl_init.hostname = buf;
1001
1002 switch (ds_proto) {
1003 case XPRT_TRANSPORT_TCP:
1004 case XPRT_TRANSPORT_TCP_TLS:
1005 if (mds_clp->cl_nconnect > 1) {
1006 cl_init.nconnect = mds_clp->cl_nconnect;
1007 cl_init.max_connect = NFS_MAX_TRANSPORTS;
1008 }
1009 }
1010
1011 if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
1012 __set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
1013
1014 __set_bit(NFS_CS_DS, &cl_init.init_flags);
1015 __set_bit(NFS_CS_PNFS, &cl_init.init_flags);
1016 cl_init.max_connect = NFS_MAX_TRANSPORTS;
1017 /*
1018 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
1019 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
1020 * (section 13.1 RFC 5661).
1021 */
1022 nfs_init_timeout_values(to: &ds_timeout, proto: ds_proto, timeo: ds_timeo, retrans: ds_retrans);
1023 return nfs_get_client(&cl_init);
1024}
1025EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
1026
1027/*
1028 * Session has been established, and the client marked ready.
1029 * Limit the mount rsize, wsize and dtsize using negotiated fore
1030 * channel attributes.
1031 */
1032static void nfs4_session_limit_rwsize(struct nfs_server *server)
1033{
1034#ifdef CONFIG_NFS_V4_1
1035 struct nfs4_session *sess;
1036 u32 server_resp_sz;
1037 u32 server_rqst_sz;
1038
1039 if (!nfs4_has_session(clp: server->nfs_client))
1040 return;
1041 sess = server->nfs_client->cl_session;
1042 server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
1043 server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
1044
1045 if (server->dtsize > server_resp_sz)
1046 server->dtsize = server_resp_sz;
1047 if (server->rsize > server_resp_sz)
1048 server->rsize = server_resp_sz;
1049 if (server->wsize > server_rqst_sz)
1050 server->wsize = server_rqst_sz;
1051#endif /* CONFIG_NFS_V4_1 */
1052}
1053
1054/*
1055 * Limit xattr sizes using the channel attributes.
1056 */
1057static void nfs4_session_limit_xasize(struct nfs_server *server)
1058{
1059#ifdef CONFIG_NFS_V4_2
1060 struct nfs4_session *sess;
1061 u32 server_gxa_sz;
1062 u32 server_sxa_sz;
1063 u32 server_lxa_sz;
1064
1065 if (!nfs4_has_session(clp: server->nfs_client))
1066 return;
1067
1068 sess = server->nfs_client->cl_session;
1069
1070 server_gxa_sz = sess->fc_attrs.max_resp_sz - nfs42_maxgetxattr_overhead;
1071 server_sxa_sz = sess->fc_attrs.max_rqst_sz - nfs42_maxsetxattr_overhead;
1072 server_lxa_sz = sess->fc_attrs.max_resp_sz -
1073 nfs42_maxlistxattrs_overhead;
1074
1075 if (server->gxasize > server_gxa_sz)
1076 server->gxasize = server_gxa_sz;
1077 if (server->sxasize > server_sxa_sz)
1078 server->sxasize = server_sxa_sz;
1079 if (server->lxasize > server_lxa_sz)
1080 server->lxasize = server_lxa_sz;
1081#endif
1082}
1083
1084void nfs4_server_set_init_caps(struct nfs_server *server)
1085{
1086 /* Set the basic capabilities */
1087 server->caps |= server->nfs_client->cl_mvops->init_caps;
1088 if (server->flags & NFS_MOUNT_NORDIRPLUS)
1089 server->caps &= ~NFS_CAP_READDIRPLUS;
1090 if (server->nfs_client->cl_proto == XPRT_TRANSPORT_RDMA)
1091 server->caps &= ~NFS_CAP_READ_PLUS;
1092
1093 /*
1094 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
1095 * authentication.
1096 */
1097 if (nfs4_disable_idmapping &&
1098 server->client->cl_auth->au_flavor == RPC_AUTH_UNIX)
1099 server->caps |= NFS_CAP_UIDGID_NOMAP;
1100}
1101
1102static int nfs4_server_common_setup(struct nfs_server *server,
1103 struct nfs_fh *mntfh, bool auth_probe)
1104{
1105 int error;
1106
1107 /* data servers support only a subset of NFSv4.1 */
1108 if (is_ds_only_client(clp: server->nfs_client))
1109 return -EPROTONOSUPPORT;
1110
1111 /* We must ensure the session is initialised first */
1112 error = nfs4_init_session(clp: server->nfs_client);
1113 if (error < 0)
1114 goto out;
1115
1116 nfs4_server_set_init_caps(server);
1117
1118 /* Probe the root fh to retrieve its FSID and filehandle */
1119 error = nfs4_get_rootfh(server, mntfh, auth_probe);
1120 if (error < 0)
1121 goto out;
1122
1123 dprintk("Server FSID: %llx:%llx\n",
1124 (unsigned long long) server->fsid.major,
1125 (unsigned long long) server->fsid.minor);
1126 nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
1127
1128 error = nfs_probe_server(server, mntfh);
1129 if (error < 0)
1130 goto out;
1131
1132 nfs4_session_limit_rwsize(server);
1133 nfs4_session_limit_xasize(server);
1134
1135 if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1136 server->namelen = NFS4_MAXNAMLEN;
1137
1138 nfs_server_insert_lists(server);
1139 server->mount_time = jiffies;
1140 server->destroy = nfs4_destroy_server;
1141out:
1142 return error;
1143}
1144
1145/*
1146 * Create a version 4 volume record
1147 */
1148static int nfs4_init_server(struct nfs_server *server, struct fs_context *fc)
1149{
1150 struct nfs_fs_context *ctx = nfs_fc2context(fc);
1151 struct rpc_timeout timeparms;
1152 int error;
1153
1154 nfs_init_timeout_values(to: &timeparms, proto: ctx->nfs_server.protocol,
1155 timeo: ctx->timeo, retrans: ctx->retrans);
1156
1157 /* Initialise the client representation from the mount data */
1158 server->flags = ctx->flags;
1159 server->options = ctx->options;
1160 server->auth_info = ctx->auth_info;
1161
1162 /* Use the first specified auth flavor. If this flavor isn't
1163 * allowed by the server, use the SECINFO path to try the
1164 * other specified flavors */
1165 if (ctx->auth_info.flavor_len >= 1)
1166 ctx->selected_flavor = ctx->auth_info.flavors[0];
1167 else
1168 ctx->selected_flavor = RPC_AUTH_UNIX;
1169
1170 /* Get a client record */
1171 error = nfs4_set_client(server,
1172 hostname: ctx->nfs_server.hostname,
1173 addr: &ctx->nfs_server._address,
1174 addrlen: ctx->nfs_server.addrlen,
1175 ip_addr: ctx->client_address,
1176 proto: ctx->nfs_server.protocol,
1177 timeparms: &timeparms,
1178 minorversion: ctx->minorversion,
1179 nconnect: ctx->nfs_server.nconnect,
1180 max_connect: ctx->nfs_server.max_connect,
1181 net: fc->net_ns,
1182 xprtsec: &ctx->xprtsec);
1183 if (error < 0)
1184 return error;
1185
1186 if (ctx->rsize)
1187 server->rsize = nfs_io_size(iosize: ctx->rsize, proto: server->nfs_client->cl_proto);
1188 if (ctx->wsize)
1189 server->wsize = nfs_io_size(iosize: ctx->wsize, proto: server->nfs_client->cl_proto);
1190
1191 server->acregmin = ctx->acregmin * HZ;
1192 server->acregmax = ctx->acregmax * HZ;
1193 server->acdirmin = ctx->acdirmin * HZ;
1194 server->acdirmax = ctx->acdirmax * HZ;
1195 server->port = ctx->nfs_server.port;
1196
1197 return nfs_init_server_rpcclient(server, t: &timeparms,
1198 ctx->selected_flavor);
1199}
1200
1201/*
1202 * Create a version 4 volume record
1203 * - keyed on server and FSID
1204 */
1205struct nfs_server *nfs4_create_server(struct fs_context *fc)
1206{
1207 struct nfs_fs_context *ctx = nfs_fc2context(fc);
1208 struct nfs_server *server;
1209 bool auth_probe;
1210 int error;
1211
1212 server = nfs_alloc_server();
1213 if (!server)
1214 return ERR_PTR(error: -ENOMEM);
1215
1216 server->cred = get_cred(cred: fc->cred);
1217
1218 auth_probe = ctx->auth_info.flavor_len < 1;
1219
1220 /* set up the general RPC client */
1221 error = nfs4_init_server(server, fc);
1222 if (error < 0)
1223 goto error;
1224
1225 error = nfs4_server_common_setup(server, mntfh: ctx->mntfh, auth_probe);
1226 if (error < 0)
1227 goto error;
1228
1229 return server;
1230
1231error:
1232 nfs_free_server(server);
1233 return ERR_PTR(error);
1234}
1235
1236/*
1237 * Create an NFS4 referral server record
1238 */
1239struct nfs_server *nfs4_create_referral_server(struct fs_context *fc)
1240{
1241 struct nfs_fs_context *ctx = nfs_fc2context(fc);
1242 struct nfs_client *parent_client;
1243 struct nfs_server *server, *parent_server;
1244 int proto, error;
1245 bool auth_probe;
1246
1247 server = nfs_alloc_server();
1248 if (!server)
1249 return ERR_PTR(error: -ENOMEM);
1250
1251 parent_server = NFS_SB(s: ctx->clone_data.sb);
1252 parent_client = parent_server->nfs_client;
1253
1254 server->cred = get_cred(cred: parent_server->cred);
1255
1256 /* Initialise the client representation from the parent server */
1257 nfs_server_copy_userdata(server, parent_server);
1258
1259 /* Get a client representation */
1260#if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
1261 rpc_set_port(sap: &ctx->nfs_server.address, NFS_RDMA_PORT);
1262 error = nfs4_set_client(server,
1263 hostname: ctx->nfs_server.hostname,
1264 addr: &ctx->nfs_server._address,
1265 addrlen: ctx->nfs_server.addrlen,
1266 ip_addr: parent_client->cl_ipaddr,
1267 proto: XPRT_TRANSPORT_RDMA,
1268 timeparms: parent_server->client->cl_timeout,
1269 minorversion: parent_client->cl_mvops->minor_version,
1270 nconnect: parent_client->cl_nconnect,
1271 max_connect: parent_client->cl_max_connect,
1272 net: parent_client->cl_net,
1273 xprtsec: &parent_client->cl_xprtsec);
1274 if (!error)
1275 goto init_server;
1276#endif /* IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA) */
1277
1278 proto = XPRT_TRANSPORT_TCP;
1279 if (parent_client->cl_xprtsec.policy != RPC_XPRTSEC_NONE)
1280 proto = XPRT_TRANSPORT_TCP_TLS;
1281 rpc_set_port(sap: &ctx->nfs_server.address, NFS_PORT);
1282 error = nfs4_set_client(server,
1283 hostname: ctx->nfs_server.hostname,
1284 addr: &ctx->nfs_server._address,
1285 addrlen: ctx->nfs_server.addrlen,
1286 ip_addr: parent_client->cl_ipaddr,
1287 proto,
1288 timeparms: parent_server->client->cl_timeout,
1289 minorversion: parent_client->cl_mvops->minor_version,
1290 nconnect: parent_client->cl_nconnect,
1291 max_connect: parent_client->cl_max_connect,
1292 net: parent_client->cl_net,
1293 xprtsec: &parent_client->cl_xprtsec);
1294 if (error < 0)
1295 goto error;
1296
1297#if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
1298init_server:
1299#endif
1300 error = nfs_init_server_rpcclient(server, t: parent_server->client->cl_timeout,
1301 ctx->selected_flavor);
1302 if (error < 0)
1303 goto error;
1304
1305 auth_probe = parent_server->auth_info.flavor_len < 1;
1306
1307 error = nfs4_server_common_setup(server, mntfh: ctx->mntfh, auth_probe);
1308 if (error < 0)
1309 goto error;
1310
1311 return server;
1312
1313error:
1314 nfs_free_server(server);
1315 return ERR_PTR(error);
1316}
1317
1318/**
1319 * nfs4_update_server - Move an nfs_server to a different nfs_client
1320 *
1321 * @server: represents FSID to be moved
1322 * @hostname: new end-point's hostname
1323 * @sap: new end-point's socket address
1324 * @salen: size of "sap"
1325 * @net: net namespace
1326 *
1327 * The nfs_server must be quiescent before this function is invoked.
1328 * Either its session is drained (NFSv4.1+), or its transport is
1329 * plugged and drained (NFSv4.0).
1330 *
1331 * Returns zero on success, or a negative errno value.
1332 */
1333int nfs4_update_server(struct nfs_server *server, const char *hostname,
1334 struct sockaddr_storage *sap, size_t salen, struct net *net)
1335{
1336 struct nfs_client *clp = server->nfs_client;
1337 struct rpc_clnt *clnt = server->client;
1338 struct xprt_create xargs = {
1339 .ident = clp->cl_proto,
1340 .net = net,
1341 .dstaddr = (struct sockaddr *)sap,
1342 .addrlen = salen,
1343 .servername = hostname,
1344 /* cel: bleh. We might need to pass TLS parameters here */
1345 };
1346 char buf[INET6_ADDRSTRLEN + 1];
1347 struct sockaddr_storage address;
1348 struct sockaddr *localaddr = (struct sockaddr *)&address;
1349 int error;
1350
1351 error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
1352 if (error != 0)
1353 return error;
1354
1355 error = rpc_localaddr(clnt, localaddr, sizeof(address));
1356 if (error != 0)
1357 return error;
1358
1359 if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0)
1360 return -EAFNOSUPPORT;
1361
1362 nfs_server_remove_lists(server);
1363 set_bit(NFS_MIG_TSM_POSSIBLE, addr: &server->mig_status);
1364 error = nfs4_set_client(server, hostname, addr: sap, addrlen: salen, ip_addr: buf,
1365 proto: clp->cl_proto, timeparms: clnt->cl_timeout,
1366 minorversion: clp->cl_minorversion,
1367 nconnect: clp->cl_nconnect, max_connect: clp->cl_max_connect,
1368 net, xprtsec: &clp->cl_xprtsec);
1369 clear_bit(NFS_MIG_TSM_POSSIBLE, addr: &server->mig_status);
1370 if (error != 0) {
1371 nfs_server_insert_lists(server);
1372 return error;
1373 }
1374 nfs_put_client(clp);
1375
1376 if (server->nfs_client->cl_hostname == NULL) {
1377 server->nfs_client->cl_hostname = kstrdup(s: hostname, GFP_KERNEL);
1378 if (server->nfs_client->cl_hostname == NULL)
1379 return -ENOMEM;
1380 }
1381 nfs_server_insert_lists(server);
1382
1383 return nfs_probe_server(server, NFS_FH(inode: d_inode(dentry: server->super->s_root)));
1384}
1385

source code of linux/fs/nfs/nfs4client.c