• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 
22 #define NFSDBG_FACILITY		NFSDBG_CLIENT
23 
24 /*
25  * Get a unique NFSv4.0 callback identifier which will be used
26  * by the V4.0 callback service to lookup the nfs_client struct
27  */
nfs_get_cb_ident_idr(struct nfs_client * clp,int minorversion)28 static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
29 {
30 	int ret = 0;
31 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
32 
33 	if (clp->rpc_ops->version != 4 || minorversion != 0)
34 		return ret;
35 	idr_preload(GFP_KERNEL);
36 	spin_lock(&nn->nfs_client_lock);
37 	ret = idr_alloc(&nn->cb_ident_idr, clp, 1, 0, GFP_NOWAIT);
38 	if (ret >= 0)
39 		clp->cl_cb_ident = ret;
40 	spin_unlock(&nn->nfs_client_lock);
41 	idr_preload_end();
42 	return ret < 0 ? ret : 0;
43 }
44 
45 #ifdef CONFIG_NFS_V4_1
46 /*
47  * Per auth flavor data server rpc clients
48  */
49 struct nfs4_ds_server {
50 	struct list_head	list;   /* ds_clp->cl_ds_clients */
51 	struct rpc_clnt		*rpc_clnt;
52 };
53 
54 /**
55  * nfs4_find_ds_client - Common lookup case for DS I/O
56  * @ds_clp: pointer to the DS's nfs_client
57  * @flavor: rpc auth flavour to match
58  */
59 static struct nfs4_ds_server *
nfs4_find_ds_client(struct nfs_client * ds_clp,rpc_authflavor_t flavor)60 nfs4_find_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
61 {
62 	struct nfs4_ds_server *dss;
63 
64 	rcu_read_lock();
65 	list_for_each_entry_rcu(dss, &ds_clp->cl_ds_clients, list) {
66 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
67 			continue;
68 		goto out;
69 	}
70 	dss = NULL;
71 out:
72 	rcu_read_unlock();
73 	return dss;
74 }
75 
76 static struct nfs4_ds_server *
nfs4_add_ds_client(struct nfs_client * ds_clp,rpc_authflavor_t flavor,struct nfs4_ds_server * new)77 nfs4_add_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor,
78 			   struct nfs4_ds_server *new)
79 {
80 	struct nfs4_ds_server *dss;
81 
82 	spin_lock(&ds_clp->cl_lock);
83 	list_for_each_entry(dss, &ds_clp->cl_ds_clients, list) {
84 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
85 			continue;
86 		goto out;
87 	}
88 	if (new)
89 		list_add_rcu(&new->list, &ds_clp->cl_ds_clients);
90 	dss = new;
91 out:
92 	spin_unlock(&ds_clp->cl_lock); /* need some lock to protect list */
93 	return dss;
94 }
95 
96 static struct nfs4_ds_server *
nfs4_alloc_ds_server(struct nfs_client * ds_clp,rpc_authflavor_t flavor)97 nfs4_alloc_ds_server(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
98 {
99 	struct nfs4_ds_server *dss;
100 
101 	dss = kmalloc(sizeof(*dss), GFP_NOFS);
102 	if (dss == NULL)
103 		return ERR_PTR(-ENOMEM);
104 
105 	dss->rpc_clnt = rpc_clone_client_set_auth(ds_clp->cl_rpcclient, flavor);
106 	if (IS_ERR(dss->rpc_clnt)) {
107 		int err = PTR_ERR(dss->rpc_clnt);
108 		kfree (dss);
109 		return ERR_PTR(err);
110 	}
111 	INIT_LIST_HEAD(&dss->list);
112 
113 	return dss;
114 }
115 
116 static void
nfs4_free_ds_server(struct nfs4_ds_server * dss)117 nfs4_free_ds_server(struct nfs4_ds_server *dss)
118 {
119 	rpc_release_client(dss->rpc_clnt);
120 	kfree(dss);
121 }
122 
123 /**
124  * nfs4_find_or_create_ds_client - Find or create a DS rpc client
125  * @ds_clp: pointer to the DS's nfs_client
126  * @inode: pointer to the inode
127  *
128  * Find or create a DS rpc client with th MDS server rpc client auth flavor
129  * in the nfs_client cl_ds_clients list.
130  */
131 struct rpc_clnt *
nfs4_find_or_create_ds_client(struct nfs_client * ds_clp,struct inode * inode)132 nfs4_find_or_create_ds_client(struct nfs_client *ds_clp, struct inode *inode)
133 {
134 	struct nfs4_ds_server *dss, *new;
135 	rpc_authflavor_t flavor = NFS_SERVER(inode)->client->cl_auth->au_flavor;
136 
137 	dss = nfs4_find_ds_client(ds_clp, flavor);
138 	if (dss != NULL)
139 		goto out;
140 	new = nfs4_alloc_ds_server(ds_clp, flavor);
141 	if (IS_ERR(new))
142 		return ERR_CAST(new);
143 	dss = nfs4_add_ds_client(ds_clp, flavor, new);
144 	if (dss != new)
145 		nfs4_free_ds_server(new);
146 out:
147 	return dss->rpc_clnt;
148 }
149 EXPORT_SYMBOL_GPL(nfs4_find_or_create_ds_client);
150 
151 static void
nfs4_shutdown_ds_clients(struct nfs_client * clp)152 nfs4_shutdown_ds_clients(struct nfs_client *clp)
153 {
154 	struct nfs4_ds_server *dss;
155 
156 	while (!list_empty(&clp->cl_ds_clients)) {
157 		dss = list_entry(clp->cl_ds_clients.next,
158 					struct nfs4_ds_server, list);
159 		list_del(&dss->list);
160 		rpc_shutdown_client(dss->rpc_clnt);
161 		kfree (dss);
162 	}
163 }
164 
165 static void
nfs4_cleanup_callback(struct nfs_client * clp)166 nfs4_cleanup_callback(struct nfs_client *clp)
167 {
168 	struct nfs4_copy_state *cp_state;
169 
170 	while (!list_empty(&clp->pending_cb_stateids)) {
171 		cp_state = list_entry(clp->pending_cb_stateids.next,
172 					struct nfs4_copy_state, copies);
173 		list_del(&cp_state->copies);
174 		kfree(cp_state);
175 	}
176 }
177 
nfs41_shutdown_client(struct nfs_client * clp)178 void nfs41_shutdown_client(struct nfs_client *clp)
179 {
180 	if (nfs4_has_session(clp)) {
181 		nfs4_cleanup_callback(clp);
182 		nfs4_shutdown_ds_clients(clp);
183 		nfs4_destroy_session(clp->cl_session);
184 		nfs4_destroy_clientid(clp);
185 	}
186 
187 }
188 #endif	/* CONFIG_NFS_V4_1 */
189 
nfs40_shutdown_client(struct nfs_client * clp)190 void nfs40_shutdown_client(struct nfs_client *clp)
191 {
192 	if (clp->cl_slot_tbl) {
193 		nfs4_shutdown_slot_table(clp->cl_slot_tbl);
194 		kfree(clp->cl_slot_tbl);
195 	}
196 }
197 
nfs4_alloc_client(const struct nfs_client_initdata * cl_init)198 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
199 {
200 	char buf[INET6_ADDRSTRLEN + 1];
201 	const char *ip_addr = cl_init->ip_addr;
202 	struct nfs_client *clp = nfs_alloc_client(cl_init);
203 	int err;
204 
205 	if (IS_ERR(clp))
206 		return clp;
207 
208 	err = nfs_get_cb_ident_idr(clp, cl_init->minorversion);
209 	if (err)
210 		goto error;
211 
212 	if (cl_init->minorversion > NFS4_MAX_MINOR_VERSION) {
213 		err = -EINVAL;
214 		goto error;
215 	}
216 
217 	spin_lock_init(&clp->cl_lock);
218 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
219 	INIT_LIST_HEAD(&clp->cl_ds_clients);
220 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
221 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
222 	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
223 	clp->cl_mig_gen = 1;
224 #if IS_ENABLED(CONFIG_NFS_V4_1)
225 	init_waitqueue_head(&clp->cl_lock_waitq);
226 #endif
227 	INIT_LIST_HEAD(&clp->pending_cb_stateids);
228 
229 	if (cl_init->minorversion != 0)
230 		__set_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags);
231 	__set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
232 	__set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags);
233 
234 	if (test_bit(NFS_CS_DS, &cl_init->init_flags))
235 		__set_bit(NFS_CS_DS, &clp->cl_flags);
236 	/*
237 	 * Set up the connection to the server before we add add to the
238 	 * global list.
239 	 */
240 	err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_GSS_KRB5I);
241 	if (err == -EINVAL)
242 		err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
243 	if (err < 0)
244 		goto error;
245 
246 	/* If no clientaddr= option was specified, find a usable cb address */
247 	if (ip_addr == NULL) {
248 		struct sockaddr_storage cb_addr;
249 		struct sockaddr *sap = (struct sockaddr *)&cb_addr;
250 
251 		err = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
252 		if (err < 0)
253 			goto error;
254 		err = rpc_ntop(sap, buf, sizeof(buf));
255 		if (err < 0)
256 			goto error;
257 		ip_addr = (const char *)buf;
258 	}
259 	strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
260 
261 	err = nfs_idmap_new(clp);
262 	if (err < 0) {
263 		dprintk("%s: failed to create idmapper. Error = %d\n",
264 			__func__, err);
265 		goto error;
266 	}
267 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
268 	return clp;
269 
270 error:
271 	nfs_free_client(clp);
272 	return ERR_PTR(err);
273 }
274 
275 /*
276  * Destroy the NFS4 callback service
277  */
nfs4_destroy_callback(struct nfs_client * clp)278 static void nfs4_destroy_callback(struct nfs_client *clp)
279 {
280 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
281 		nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
282 }
283 
nfs4_shutdown_client(struct nfs_client * clp)284 static void nfs4_shutdown_client(struct nfs_client *clp)
285 {
286 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
287 		nfs4_kill_renewd(clp);
288 	clp->cl_mvops->shutdown_client(clp);
289 	nfs4_destroy_callback(clp);
290 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
291 		nfs_idmap_delete(clp);
292 
293 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
294 	kfree(clp->cl_serverowner);
295 	kfree(clp->cl_serverscope);
296 	kfree(clp->cl_implid);
297 	kfree(clp->cl_owner_id);
298 }
299 
nfs4_free_client(struct nfs_client * clp)300 void nfs4_free_client(struct nfs_client *clp)
301 {
302 	nfs4_shutdown_client(clp);
303 	nfs_free_client(clp);
304 }
305 
306 /*
307  * Initialize the NFS4 callback service
308  */
nfs4_init_callback(struct nfs_client * clp)309 static int nfs4_init_callback(struct nfs_client *clp)
310 {
311 	struct rpc_xprt *xprt;
312 	int error;
313 
314 	xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
315 
316 	if (nfs4_has_session(clp)) {
317 		error = xprt_setup_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
318 		if (error < 0)
319 			return error;
320 	}
321 
322 	error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
323 	if (error < 0) {
324 		dprintk("%s: failed to start callback. Error = %d\n",
325 			__func__, error);
326 		return error;
327 	}
328 	__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
329 
330 	return 0;
331 }
332 
333 /**
334  * nfs40_init_client - nfs_client initialization tasks for NFSv4.0
335  * @clp: nfs_client to initialize
336  *
337  * Returns zero on success, or a negative errno if some error occurred.
338  */
nfs40_init_client(struct nfs_client * clp)339 int nfs40_init_client(struct nfs_client *clp)
340 {
341 	struct nfs4_slot_table *tbl;
342 	int ret;
343 
344 	tbl = kzalloc(sizeof(*tbl), GFP_NOFS);
345 	if (tbl == NULL)
346 		return -ENOMEM;
347 
348 	ret = nfs4_setup_slot_table(tbl, NFS4_MAX_SLOT_TABLE,
349 					"NFSv4.0 transport Slot table");
350 	if (ret) {
351 		nfs4_shutdown_slot_table(tbl);
352 		kfree(tbl);
353 		return ret;
354 	}
355 
356 	clp->cl_slot_tbl = tbl;
357 	return 0;
358 }
359 
360 #if defined(CONFIG_NFS_V4_1)
361 
362 /**
363  * nfs41_init_client - nfs_client initialization tasks for NFSv4.1+
364  * @clp: nfs_client to initialize
365  *
366  * Returns zero on success, or a negative errno if some error occurred.
367  */
nfs41_init_client(struct nfs_client * clp)368 int nfs41_init_client(struct nfs_client *clp)
369 {
370 	struct nfs4_session *session = NULL;
371 
372 	/*
373 	 * Create the session and mark it expired.
374 	 * When a SEQUENCE operation encounters the expired session
375 	 * it will do session recovery to initialize it.
376 	 */
377 	session = nfs4_alloc_session(clp);
378 	if (!session)
379 		return -ENOMEM;
380 
381 	clp->cl_session = session;
382 
383 	/*
384 	 * The create session reply races with the server back
385 	 * channel probe. Mark the client NFS_CS_SESSION_INITING
386 	 * so that the client back channel can find the
387 	 * nfs_client struct
388 	 */
389 	nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
390 	return 0;
391 }
392 
393 #endif	/* CONFIG_NFS_V4_1 */
394 
395 /*
396  * Initialize the minor version specific parts of an NFS4 client record
397  */
nfs4_init_client_minor_version(struct nfs_client * clp)398 static int nfs4_init_client_minor_version(struct nfs_client *clp)
399 {
400 	int ret;
401 
402 	ret = clp->cl_mvops->init_client(clp);
403 	if (ret)
404 		return ret;
405 	return nfs4_init_callback(clp);
406 }
407 
nfs4_add_trunk(struct nfs_client * clp,struct nfs_client * old)408 static void nfs4_add_trunk(struct nfs_client *clp, struct nfs_client *old)
409 {
410 	struct sockaddr_storage clp_addr, old_addr;
411 	struct sockaddr *clp_sap = (struct sockaddr *)&clp_addr;
412 	struct sockaddr *old_sap = (struct sockaddr *)&old_addr;
413 	size_t clp_salen;
414 	struct xprt_create xprt_args = {
415 		.ident = old->cl_proto,
416 		.net = old->cl_net,
417 		.servername = old->cl_hostname,
418 	};
419 	int max_connect = test_bit(NFS_CS_PNFS, &clp->cl_flags) ?
420 		clp->cl_max_connect : old->cl_max_connect;
421 
422 	if (clp->cl_proto != old->cl_proto)
423 		return;
424 	clp_salen = rpc_peeraddr(clp->cl_rpcclient, clp_sap, sizeof(clp_addr));
425 	rpc_peeraddr(old->cl_rpcclient, old_sap, sizeof(old_addr));
426 
427 	if (clp_addr.ss_family != old_addr.ss_family)
428 		return;
429 
430 	xprt_args.dstaddr = clp_sap;
431 	xprt_args.addrlen = clp_salen;
432 
433 	rpc_clnt_add_xprt(old->cl_rpcclient, &xprt_args,
434 			  rpc_clnt_test_and_add_xprt, &max_connect);
435 }
436 
437 /**
438  * nfs4_init_client - Initialise an NFS4 client record
439  *
440  * @clp: nfs_client to initialise
441  * @cl_init: pointer to nfs_client_initdata
442  *
443  * Returns pointer to an NFS client, or an ERR_PTR value.
444  */
nfs4_init_client(struct nfs_client * clp,const struct nfs_client_initdata * cl_init)445 struct nfs_client *nfs4_init_client(struct nfs_client *clp,
446 				    const struct nfs_client_initdata *cl_init)
447 {
448 	struct nfs_client *old;
449 	int error;
450 
451 	if (clp->cl_cons_state == NFS_CS_READY)
452 		/* the client is initialised already */
453 		return clp;
454 
455 	error = nfs4_init_client_minor_version(clp);
456 	if (error < 0)
457 		goto error;
458 
459 	error = nfs4_discover_server_trunking(clp, &old);
460 	if (error < 0)
461 		goto error;
462 
463 	if (clp != old) {
464 		clp->cl_preserve_clid = true;
465 		/*
466 		 * Mark the client as having failed initialization so other
467 		 * processes walking the nfs_client_list in nfs_match_client()
468 		 * won't try to use it.
469 		 */
470 		nfs_mark_client_ready(clp, -EPERM);
471 		if (old->cl_mvops->session_trunk)
472 			nfs4_add_trunk(clp, old);
473 	}
474 	clear_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags);
475 	nfs_put_client(clp);
476 	return old;
477 
478 error:
479 	nfs_mark_client_ready(clp, error);
480 	nfs_put_client(clp);
481 	return ERR_PTR(error);
482 }
483 
484 /*
485  * SETCLIENTID just did a callback update with the callback ident in
486  * "drop," but server trunking discovery claims "drop" and "keep" are
487  * actually the same server.  Swap the callback IDs so that "keep"
488  * will continue to use the callback ident the server now knows about,
489  * and so that "keep"'s original callback ident is destroyed when
490  * "drop" is freed.
491  */
nfs4_swap_callback_idents(struct nfs_client * keep,struct nfs_client * drop)492 static void nfs4_swap_callback_idents(struct nfs_client *keep,
493 				      struct nfs_client *drop)
494 {
495 	struct nfs_net *nn = net_generic(keep->cl_net, nfs_net_id);
496 	unsigned int save = keep->cl_cb_ident;
497 
498 	if (keep->cl_cb_ident == drop->cl_cb_ident)
499 		return;
500 
501 	dprintk("%s: keeping callback ident %u and dropping ident %u\n",
502 		__func__, keep->cl_cb_ident, drop->cl_cb_ident);
503 
504 	spin_lock(&nn->nfs_client_lock);
505 
506 	idr_replace(&nn->cb_ident_idr, keep, drop->cl_cb_ident);
507 	keep->cl_cb_ident = drop->cl_cb_ident;
508 
509 	idr_replace(&nn->cb_ident_idr, drop, save);
510 	drop->cl_cb_ident = save;
511 
512 	spin_unlock(&nn->nfs_client_lock);
513 }
514 
nfs4_match_client_owner_id(const struct nfs_client * clp1,const struct nfs_client * clp2)515 static bool nfs4_match_client_owner_id(const struct nfs_client *clp1,
516 		const struct nfs_client *clp2)
517 {
518 	if (clp1->cl_owner_id == NULL || clp2->cl_owner_id == NULL)
519 		return true;
520 	return strcmp(clp1->cl_owner_id, clp2->cl_owner_id) == 0;
521 }
522 
nfs4_same_verifier(nfs4_verifier * v1,nfs4_verifier * v2)523 static bool nfs4_same_verifier(nfs4_verifier *v1, nfs4_verifier *v2)
524 {
525 	return memcmp(v1->data, v2->data, sizeof(v1->data)) == 0;
526 }
527 
nfs4_match_client(struct nfs_client * pos,struct nfs_client * new,struct nfs_client ** prev,struct nfs_net * nn)528 static int nfs4_match_client(struct nfs_client  *pos,  struct nfs_client *new,
529 			     struct nfs_client **prev, struct nfs_net *nn)
530 {
531 	int status;
532 
533 	if (pos->rpc_ops != new->rpc_ops)
534 		return 1;
535 
536 	if (pos->cl_minorversion != new->cl_minorversion)
537 		return 1;
538 
539 	/* If "pos" isn't marked ready, we can't trust the
540 	 * remaining fields in "pos", especially the client
541 	 * ID and serverowner fields.  Wait for CREATE_SESSION
542 	 * to finish. */
543 	if (pos->cl_cons_state > NFS_CS_READY) {
544 		refcount_inc(&pos->cl_count);
545 		spin_unlock(&nn->nfs_client_lock);
546 
547 		nfs_put_client(*prev);
548 		*prev = pos;
549 
550 		status = nfs_wait_client_init_complete(pos);
551 		spin_lock(&nn->nfs_client_lock);
552 
553 		if (status < 0)
554 			return status;
555 	}
556 
557 	if (pos->cl_cons_state != NFS_CS_READY)
558 		return 1;
559 
560 	if (pos->cl_clientid != new->cl_clientid)
561 		return 1;
562 
563 	/* NFSv4.1 always uses the uniform string, however someone
564 	 * might switch the uniquifier string on us.
565 	 */
566 	if (!nfs4_match_client_owner_id(pos, new))
567 		return 1;
568 
569 	return 0;
570 }
571 
572 /**
573  * nfs40_walk_client_list - Find server that recognizes a client ID
574  *
575  * @new: nfs_client with client ID to test
576  * @result: OUT: found nfs_client, or new
577  * @cred: credential to use for trunking test
578  *
579  * Returns zero, a negative errno, or a negative NFS4ERR status.
580  * If zero is returned, an nfs_client pointer is planted in "result."
581  *
582  * NB: nfs40_walk_client_list() relies on the new nfs_client being
583  *     the last nfs_client on the list.
584  */
nfs40_walk_client_list(struct nfs_client * new,struct nfs_client ** result,const struct cred * cred)585 int nfs40_walk_client_list(struct nfs_client *new,
586 			   struct nfs_client **result,
587 			   const struct cred *cred)
588 {
589 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
590 	struct nfs_client *pos, *prev = NULL;
591 	struct nfs4_setclientid_res clid = {
592 		.clientid	= new->cl_clientid,
593 		.confirm	= new->cl_confirm,
594 	};
595 	int status = -NFS4ERR_STALE_CLIENTID;
596 
597 	spin_lock(&nn->nfs_client_lock);
598 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
599 
600 		if (pos == new)
601 			goto found;
602 
603 		status = nfs4_match_client(pos, new, &prev, nn);
604 		if (status < 0)
605 			goto out_unlock;
606 		if (status != 0)
607 			continue;
608 		/*
609 		 * We just sent a new SETCLIENTID, which should have
610 		 * caused the server to return a new cl_confirm.  So if
611 		 * cl_confirm is the same, then this is a different
612 		 * server that just returned the same cl_confirm by
613 		 * coincidence:
614 		 */
615 		if ((new != pos) && nfs4_same_verifier(&pos->cl_confirm,
616 						       &new->cl_confirm))
617 			continue;
618 		/*
619 		 * But if the cl_confirm's are different, then the only
620 		 * way that a SETCLIENTID_CONFIRM to pos can succeed is
621 		 * if new and pos point to the same server:
622 		 */
623 found:
624 		refcount_inc(&pos->cl_count);
625 		spin_unlock(&nn->nfs_client_lock);
626 
627 		nfs_put_client(prev);
628 		prev = pos;
629 
630 		status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
631 		switch (status) {
632 		case -NFS4ERR_STALE_CLIENTID:
633 			break;
634 		case 0:
635 			nfs4_swap_callback_idents(pos, new);
636 			pos->cl_confirm = new->cl_confirm;
637 			nfs_mark_client_ready(pos, NFS_CS_READY);
638 
639 			prev = NULL;
640 			*result = pos;
641 			goto out;
642 		case -ERESTARTSYS:
643 		case -ETIMEDOUT:
644 			/* The callback path may have been inadvertently
645 			 * changed. Schedule recovery!
646 			 */
647 			nfs4_schedule_path_down_recovery(pos);
648 			goto out;
649 		default:
650 			goto out;
651 		}
652 
653 		spin_lock(&nn->nfs_client_lock);
654 	}
655 out_unlock:
656 	spin_unlock(&nn->nfs_client_lock);
657 
658 	/* No match found. The server lost our clientid */
659 out:
660 	nfs_put_client(prev);
661 	return status;
662 }
663 
664 #ifdef CONFIG_NFS_V4_1
665 /*
666  * Returns true if the server major ids match
667  */
668 bool
nfs4_check_serverowner_major_id(struct nfs41_server_owner * o1,struct nfs41_server_owner * o2)669 nfs4_check_serverowner_major_id(struct nfs41_server_owner *o1,
670 				struct nfs41_server_owner *o2)
671 {
672 	if (o1->major_id_sz != o2->major_id_sz)
673 		return false;
674 	return memcmp(o1->major_id, o2->major_id, o1->major_id_sz) == 0;
675 }
676 
677 /*
678  * Returns true if the server scopes match
679  */
680 static bool
nfs4_check_server_scope(struct nfs41_server_scope * s1,struct nfs41_server_scope * s2)681 nfs4_check_server_scope(struct nfs41_server_scope *s1,
682 			struct nfs41_server_scope *s2)
683 {
684 	if (s1->server_scope_sz != s2->server_scope_sz)
685 		return false;
686 	return memcmp(s1->server_scope, s2->server_scope,
687 					s1->server_scope_sz) == 0;
688 }
689 
690 /**
691  * nfs4_detect_session_trunking - Checks for session trunking.
692  * @clp:    original mount nfs_client
693  * @res:    result structure from an exchange_id using the original mount
694  *          nfs_client with a new multi_addr transport
695  * @xprt:   pointer to the transport to add.
696  *
697  * Called after a successful EXCHANGE_ID on a multi-addr connection.
698  * Upon success, add the transport.
699  *
700  * Returns zero on success, otherwise -EINVAL
701  *
702  * Note: since the exchange_id for the new multi_addr transport uses the
703  * same nfs_client from the original mount, the cl_owner_id is reused,
704  * so eir_clientowner is the same.
705  */
nfs4_detect_session_trunking(struct nfs_client * clp,struct nfs41_exchange_id_res * res,struct rpc_xprt * xprt)706 int nfs4_detect_session_trunking(struct nfs_client *clp,
707 				 struct nfs41_exchange_id_res *res,
708 				 struct rpc_xprt *xprt)
709 {
710 	/* Check eir_clientid */
711 	if (clp->cl_clientid != res->clientid)
712 		goto out_err;
713 
714 	/* Check eir_server_owner so_major_id */
715 	if (!nfs4_check_serverowner_major_id(clp->cl_serverowner,
716 					     res->server_owner))
717 		goto out_err;
718 
719 	/* Check eir_server_owner so_minor_id */
720 	if (clp->cl_serverowner->minor_id != res->server_owner->minor_id)
721 		goto out_err;
722 
723 	/* Check eir_server_scope */
724 	if (!nfs4_check_server_scope(clp->cl_serverscope, res->server_scope))
725 		goto out_err;
726 
727 	pr_info("NFS:  %s: Session trunking succeeded for %s\n",
728 		clp->cl_hostname,
729 		xprt->address_strings[RPC_DISPLAY_ADDR]);
730 
731 	return 0;
732 out_err:
733 	pr_info("NFS:  %s: Session trunking failed for %s\n", clp->cl_hostname,
734 		xprt->address_strings[RPC_DISPLAY_ADDR]);
735 
736 	return -EINVAL;
737 }
738 
739 /**
740  * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
741  *
742  * @new: nfs_client with client ID to test
743  * @result: OUT: found nfs_client, or new
744  * @cred: credential to use for trunking test
745  *
746  * Returns zero, a negative errno, or a negative NFS4ERR status.
747  * If zero is returned, an nfs_client pointer is planted in "result."
748  *
749  * NB: nfs41_walk_client_list() relies on the new nfs_client being
750  *     the last nfs_client on the list.
751  */
nfs41_walk_client_list(struct nfs_client * new,struct nfs_client ** result,const struct cred * cred)752 int nfs41_walk_client_list(struct nfs_client *new,
753 			   struct nfs_client **result,
754 			   const struct cred *cred)
755 {
756 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
757 	struct nfs_client *pos, *prev = NULL;
758 	int status = -NFS4ERR_STALE_CLIENTID;
759 
760 	spin_lock(&nn->nfs_client_lock);
761 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
762 
763 		if (pos == new)
764 			goto found;
765 
766 		status = nfs4_match_client(pos, new, &prev, nn);
767 		if (status < 0)
768 			goto out;
769 		if (status != 0)
770 			continue;
771 
772 		/*
773 		 * Note that session trunking is just a special subcase of
774 		 * client id trunking. In either case, we want to fall back
775 		 * to using the existing nfs_client.
776 		 */
777 		if (!nfs4_check_serverowner_major_id(pos->cl_serverowner,
778 						     new->cl_serverowner))
779 			continue;
780 
781 found:
782 		refcount_inc(&pos->cl_count);
783 		*result = pos;
784 		status = 0;
785 		break;
786 	}
787 
788 out:
789 	spin_unlock(&nn->nfs_client_lock);
790 	nfs_put_client(prev);
791 	return status;
792 }
793 #endif	/* CONFIG_NFS_V4_1 */
794 
nfs4_destroy_server(struct nfs_server * server)795 static void nfs4_destroy_server(struct nfs_server *server)
796 {
797 	LIST_HEAD(freeme);
798 
799 	nfs_server_return_all_delegations(server);
800 	unset_pnfs_layoutdriver(server);
801 	nfs4_purge_state_owners(server, &freeme);
802 	nfs4_free_state_owners(&freeme);
803 }
804 
805 /*
806  * NFSv4.0 callback thread helper
807  *
808  * Find a client by callback identifier
809  */
810 struct nfs_client *
nfs4_find_client_ident(struct net * net,int cb_ident)811 nfs4_find_client_ident(struct net *net, int cb_ident)
812 {
813 	struct nfs_client *clp;
814 	struct nfs_net *nn = net_generic(net, nfs_net_id);
815 
816 	spin_lock(&nn->nfs_client_lock);
817 	clp = idr_find(&nn->cb_ident_idr, cb_ident);
818 	if (clp)
819 		refcount_inc(&clp->cl_count);
820 	spin_unlock(&nn->nfs_client_lock);
821 	return clp;
822 }
823 
824 #if defined(CONFIG_NFS_V4_1)
825 /* Common match routine for v4.0 and v4.1 callback services */
nfs4_cb_match_client(const struct sockaddr * addr,struct nfs_client * clp,u32 minorversion)826 static bool nfs4_cb_match_client(const struct sockaddr *addr,
827 		struct nfs_client *clp, u32 minorversion)
828 {
829 	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
830 
831 	/* Don't match clients that failed to initialise */
832 	if (!(clp->cl_cons_state == NFS_CS_READY ||
833 	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
834 		return false;
835 
836 	smp_rmb();
837 
838 	/* Match the version and minorversion */
839 	if (clp->rpc_ops->version != 4 ||
840 	    clp->cl_minorversion != minorversion)
841 		return false;
842 
843 	/* Match only the IP address, not the port number */
844 	return rpc_cmp_addr(addr, clap);
845 }
846 
847 /*
848  * NFSv4.1 callback thread helper
849  * For CB_COMPOUND calls, find a client by IP address, protocol version,
850  * minorversion, and sessionID
851  *
852  * Returns NULL if no such client
853  */
854 struct nfs_client *
nfs4_find_client_sessionid(struct net * net,const struct sockaddr * addr,struct nfs4_sessionid * sid,u32 minorversion)855 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
856 			   struct nfs4_sessionid *sid, u32 minorversion)
857 {
858 	struct nfs_client *clp;
859 	struct nfs_net *nn = net_generic(net, nfs_net_id);
860 
861 	spin_lock(&nn->nfs_client_lock);
862 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
863 		if (!nfs4_cb_match_client(addr, clp, minorversion))
864 			continue;
865 
866 		if (!nfs4_has_session(clp))
867 			continue;
868 
869 		/* Match sessionid*/
870 		if (memcmp(clp->cl_session->sess_id.data,
871 		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
872 			continue;
873 
874 		refcount_inc(&clp->cl_count);
875 		spin_unlock(&nn->nfs_client_lock);
876 		return clp;
877 	}
878 	spin_unlock(&nn->nfs_client_lock);
879 	return NULL;
880 }
881 
882 #else /* CONFIG_NFS_V4_1 */
883 
884 struct nfs_client *
nfs4_find_client_sessionid(struct net * net,const struct sockaddr * addr,struct nfs4_sessionid * sid,u32 minorversion)885 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
886 			   struct nfs4_sessionid *sid, u32 minorversion)
887 {
888 	return NULL;
889 }
890 #endif /* CONFIG_NFS_V4_1 */
891 
892 /*
893  * Set up an NFS4 client
894  */
nfs4_set_client(struct nfs_server * server,const char * hostname,const struct sockaddr * addr,const size_t addrlen,const char * ip_addr,int proto,const struct rpc_timeout * timeparms,u32 minorversion,unsigned int nconnect,unsigned int max_connect,struct net * net)895 static int nfs4_set_client(struct nfs_server *server,
896 		const char *hostname,
897 		const struct sockaddr *addr,
898 		const size_t addrlen,
899 		const char *ip_addr,
900 		int proto, const struct rpc_timeout *timeparms,
901 		u32 minorversion, unsigned int nconnect,
902 		unsigned int max_connect,
903 		struct net *net)
904 {
905 	struct nfs_client_initdata cl_init = {
906 		.hostname = hostname,
907 		.addr = addr,
908 		.addrlen = addrlen,
909 		.ip_addr = ip_addr,
910 		.nfs_mod = &nfs_v4,
911 		.proto = proto,
912 		.minorversion = minorversion,
913 		.net = net,
914 		.timeparms = timeparms,
915 		.cred = server->cred,
916 	};
917 	struct nfs_client *clp;
918 
919 	if (minorversion == 0)
920 		__set_bit(NFS_CS_REUSEPORT, &cl_init.init_flags);
921 	else
922 		cl_init.max_connect = max_connect;
923 	if (proto == XPRT_TRANSPORT_TCP)
924 		cl_init.nconnect = nconnect;
925 
926 	if (server->flags & NFS_MOUNT_NORESVPORT)
927 		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
928 	if (server->options & NFS_OPTION_MIGRATION)
929 		__set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
930 	if (test_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status))
931 		__set_bit(NFS_CS_TSM_POSSIBLE, &cl_init.init_flags);
932 	server->port = rpc_get_port(addr);
933 
934 	/* Allocate or find a client reference we can use */
935 	clp = nfs_get_client(&cl_init);
936 	if (IS_ERR(clp))
937 		return PTR_ERR(clp);
938 
939 	if (server->nfs_client == clp) {
940 		nfs_put_client(clp);
941 		return -ELOOP;
942 	}
943 
944 	/*
945 	 * Query for the lease time on clientid setup or renewal
946 	 *
947 	 * Note that this will be set on nfs_clients that were created
948 	 * only for the DS role and did not set this bit, but now will
949 	 * serve a dual role.
950 	 */
951 	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
952 
953 	server->nfs_client = clp;
954 	return 0;
955 }
956 
957 /*
958  * Set up a pNFS Data Server client.
959  *
960  * Return any existing nfs_client that matches server address,port,version
961  * and minorversion.
962  *
963  * For a new nfs_client, use a soft mount (default), a low retrans and a
964  * low timeout interval so that if a connection is lost, we retry through
965  * the MDS.
966  */
nfs4_set_ds_client(struct nfs_server * mds_srv,const struct sockaddr * ds_addr,int ds_addrlen,int ds_proto,unsigned int ds_timeo,unsigned int ds_retrans,u32 minor_version)967 struct nfs_client *nfs4_set_ds_client(struct nfs_server *mds_srv,
968 		const struct sockaddr *ds_addr, int ds_addrlen,
969 		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans,
970 		u32 minor_version)
971 {
972 	struct rpc_timeout ds_timeout;
973 	struct nfs_client *mds_clp = mds_srv->nfs_client;
974 	struct nfs_client_initdata cl_init = {
975 		.addr = ds_addr,
976 		.addrlen = ds_addrlen,
977 		.nodename = mds_clp->cl_rpcclient->cl_nodename,
978 		.ip_addr = mds_clp->cl_ipaddr,
979 		.nfs_mod = &nfs_v4,
980 		.proto = ds_proto,
981 		.minorversion = minor_version,
982 		.net = mds_clp->cl_net,
983 		.timeparms = &ds_timeout,
984 		.cred = mds_srv->cred,
985 	};
986 	char buf[INET6_ADDRSTRLEN + 1];
987 
988 	if (rpc_ntop(ds_addr, buf, sizeof(buf)) <= 0)
989 		return ERR_PTR(-EINVAL);
990 	cl_init.hostname = buf;
991 
992 	if (mds_clp->cl_nconnect > 1 && ds_proto == XPRT_TRANSPORT_TCP) {
993 		cl_init.nconnect = mds_clp->cl_nconnect;
994 		cl_init.max_connect = NFS_MAX_TRANSPORTS;
995 	}
996 
997 	if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
998 		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
999 
1000 	__set_bit(NFS_CS_DS, &cl_init.init_flags);
1001 	__set_bit(NFS_CS_PNFS, &cl_init.init_flags);
1002 	cl_init.max_connect = NFS_MAX_TRANSPORTS;
1003 	/*
1004 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
1005 	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
1006 	 * (section 13.1 RFC 5661).
1007 	 */
1008 	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
1009 	return nfs_get_client(&cl_init);
1010 }
1011 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
1012 
1013 /*
1014  * Session has been established, and the client marked ready.
1015  * Limit the mount rsize, wsize and dtsize using negotiated fore
1016  * channel attributes.
1017  */
nfs4_session_limit_rwsize(struct nfs_server * server)1018 static void nfs4_session_limit_rwsize(struct nfs_server *server)
1019 {
1020 #ifdef CONFIG_NFS_V4_1
1021 	struct nfs4_session *sess;
1022 	u32 server_resp_sz;
1023 	u32 server_rqst_sz;
1024 
1025 	if (!nfs4_has_session(server->nfs_client))
1026 		return;
1027 	sess = server->nfs_client->cl_session;
1028 	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
1029 	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
1030 
1031 	if (server->dtsize > server_resp_sz)
1032 		server->dtsize = server_resp_sz;
1033 	if (server->rsize > server_resp_sz)
1034 		server->rsize = server_resp_sz;
1035 	if (server->wsize > server_rqst_sz)
1036 		server->wsize = server_rqst_sz;
1037 #endif /* CONFIG_NFS_V4_1 */
1038 }
1039 
1040 /*
1041  * Limit xattr sizes using the channel attributes.
1042  */
nfs4_session_limit_xasize(struct nfs_server * server)1043 static void nfs4_session_limit_xasize(struct nfs_server *server)
1044 {
1045 #ifdef CONFIG_NFS_V4_2
1046 	struct nfs4_session *sess;
1047 	u32 server_gxa_sz;
1048 	u32 server_sxa_sz;
1049 	u32 server_lxa_sz;
1050 
1051 	if (!nfs4_has_session(server->nfs_client))
1052 		return;
1053 
1054 	sess = server->nfs_client->cl_session;
1055 
1056 	server_gxa_sz = sess->fc_attrs.max_resp_sz - nfs42_maxgetxattr_overhead;
1057 	server_sxa_sz = sess->fc_attrs.max_rqst_sz - nfs42_maxsetxattr_overhead;
1058 	server_lxa_sz = sess->fc_attrs.max_resp_sz -
1059 	    nfs42_maxlistxattrs_overhead;
1060 
1061 	if (server->gxasize > server_gxa_sz)
1062 		server->gxasize = server_gxa_sz;
1063 	if (server->sxasize > server_sxa_sz)
1064 		server->sxasize = server_sxa_sz;
1065 	if (server->lxasize > server_lxa_sz)
1066 		server->lxasize = server_lxa_sz;
1067 #endif
1068 }
1069 
nfs4_server_common_setup(struct nfs_server * server,struct nfs_fh * mntfh,bool auth_probe)1070 static int nfs4_server_common_setup(struct nfs_server *server,
1071 		struct nfs_fh *mntfh, bool auth_probe)
1072 {
1073 	struct nfs_fattr *fattr;
1074 	int error;
1075 
1076 	/* data servers support only a subset of NFSv4.1 */
1077 	if (is_ds_only_client(server->nfs_client))
1078 		return -EPROTONOSUPPORT;
1079 
1080 	fattr = nfs_alloc_fattr();
1081 	if (fattr == NULL)
1082 		return -ENOMEM;
1083 
1084 	/* We must ensure the session is initialised first */
1085 	error = nfs4_init_session(server->nfs_client);
1086 	if (error < 0)
1087 		goto out;
1088 
1089 	/* Set the basic capabilities */
1090 	server->caps |= server->nfs_client->cl_mvops->init_caps;
1091 	if (server->flags & NFS_MOUNT_NORDIRPLUS)
1092 			server->caps &= ~NFS_CAP_READDIRPLUS;
1093 	if (server->nfs_client->cl_proto == XPRT_TRANSPORT_RDMA)
1094 		server->caps &= ~NFS_CAP_READ_PLUS;
1095 	/*
1096 	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
1097 	 * authentication.
1098 	 */
1099 	if (nfs4_disable_idmapping &&
1100 			server->client->cl_auth->au_flavor == RPC_AUTH_UNIX)
1101 		server->caps |= NFS_CAP_UIDGID_NOMAP;
1102 
1103 
1104 	/* Probe the root fh to retrieve its FSID and filehandle */
1105 	error = nfs4_get_rootfh(server, mntfh, auth_probe);
1106 	if (error < 0)
1107 		goto out;
1108 
1109 	dprintk("Server FSID: %llx:%llx\n",
1110 			(unsigned long long) server->fsid.major,
1111 			(unsigned long long) server->fsid.minor);
1112 	nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
1113 
1114 	error = nfs_probe_fsinfo(server, mntfh, fattr);
1115 	if (error < 0)
1116 		goto out;
1117 
1118 	nfs4_session_limit_rwsize(server);
1119 	nfs4_session_limit_xasize(server);
1120 
1121 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1122 		server->namelen = NFS4_MAXNAMLEN;
1123 
1124 	nfs_server_insert_lists(server);
1125 	server->mount_time = jiffies;
1126 	server->destroy = nfs4_destroy_server;
1127 out:
1128 	nfs_free_fattr(fattr);
1129 	return error;
1130 }
1131 
1132 /*
1133  * Create a version 4 volume record
1134  */
nfs4_init_server(struct nfs_server * server,struct fs_context * fc)1135 static int nfs4_init_server(struct nfs_server *server, struct fs_context *fc)
1136 {
1137 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1138 	struct rpc_timeout timeparms;
1139 	int error;
1140 
1141 	nfs_init_timeout_values(&timeparms, ctx->nfs_server.protocol,
1142 				ctx->timeo, ctx->retrans);
1143 
1144 	/* Initialise the client representation from the mount data */
1145 	server->flags = ctx->flags;
1146 	server->options = ctx->options;
1147 	server->auth_info = ctx->auth_info;
1148 
1149 	/* Use the first specified auth flavor. If this flavor isn't
1150 	 * allowed by the server, use the SECINFO path to try the
1151 	 * other specified flavors */
1152 	if (ctx->auth_info.flavor_len >= 1)
1153 		ctx->selected_flavor = ctx->auth_info.flavors[0];
1154 	else
1155 		ctx->selected_flavor = RPC_AUTH_UNIX;
1156 
1157 	/* Get a client record */
1158 	error = nfs4_set_client(server,
1159 				ctx->nfs_server.hostname,
1160 				&ctx->nfs_server.address,
1161 				ctx->nfs_server.addrlen,
1162 				ctx->client_address,
1163 				ctx->nfs_server.protocol,
1164 				&timeparms,
1165 				ctx->minorversion,
1166 				ctx->nfs_server.nconnect,
1167 				ctx->nfs_server.max_connect,
1168 				fc->net_ns);
1169 	if (error < 0)
1170 		return error;
1171 
1172 	if (ctx->rsize)
1173 		server->rsize = nfs_block_size(ctx->rsize, NULL);
1174 	if (ctx->wsize)
1175 		server->wsize = nfs_block_size(ctx->wsize, NULL);
1176 
1177 	server->acregmin = ctx->acregmin * HZ;
1178 	server->acregmax = ctx->acregmax * HZ;
1179 	server->acdirmin = ctx->acdirmin * HZ;
1180 	server->acdirmax = ctx->acdirmax * HZ;
1181 	server->port     = ctx->nfs_server.port;
1182 
1183 	return nfs_init_server_rpcclient(server, &timeparms,
1184 					 ctx->selected_flavor);
1185 }
1186 
1187 /*
1188  * Create a version 4 volume record
1189  * - keyed on server and FSID
1190  */
nfs4_create_server(struct fs_context * fc)1191 struct nfs_server *nfs4_create_server(struct fs_context *fc)
1192 {
1193 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1194 	struct nfs_server *server;
1195 	bool auth_probe;
1196 	int error;
1197 
1198 	server = nfs_alloc_server();
1199 	if (!server)
1200 		return ERR_PTR(-ENOMEM);
1201 
1202 	server->cred = get_cred(fc->cred);
1203 
1204 	auth_probe = ctx->auth_info.flavor_len < 1;
1205 
1206 	/* set up the general RPC client */
1207 	error = nfs4_init_server(server, fc);
1208 	if (error < 0)
1209 		goto error;
1210 
1211 	error = nfs4_server_common_setup(server, ctx->mntfh, auth_probe);
1212 	if (error < 0)
1213 		goto error;
1214 
1215 	return server;
1216 
1217 error:
1218 	nfs_free_server(server);
1219 	return ERR_PTR(error);
1220 }
1221 
1222 /*
1223  * Create an NFS4 referral server record
1224  */
nfs4_create_referral_server(struct fs_context * fc)1225 struct nfs_server *nfs4_create_referral_server(struct fs_context *fc)
1226 {
1227 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1228 	struct nfs_client *parent_client;
1229 	struct nfs_server *server, *parent_server;
1230 	bool auth_probe;
1231 	int error;
1232 
1233 	server = nfs_alloc_server();
1234 	if (!server)
1235 		return ERR_PTR(-ENOMEM);
1236 
1237 	parent_server = NFS_SB(ctx->clone_data.sb);
1238 	parent_client = parent_server->nfs_client;
1239 
1240 	server->cred = get_cred(parent_server->cred);
1241 
1242 	/* Initialise the client representation from the parent server */
1243 	nfs_server_copy_userdata(server, parent_server);
1244 
1245 	/* Get a client representation */
1246 #if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
1247 	rpc_set_port(&ctx->nfs_server.address, NFS_RDMA_PORT);
1248 	error = nfs4_set_client(server,
1249 				ctx->nfs_server.hostname,
1250 				&ctx->nfs_server.address,
1251 				ctx->nfs_server.addrlen,
1252 				parent_client->cl_ipaddr,
1253 				XPRT_TRANSPORT_RDMA,
1254 				parent_server->client->cl_timeout,
1255 				parent_client->cl_mvops->minor_version,
1256 				parent_client->cl_nconnect,
1257 				parent_client->cl_max_connect,
1258 				parent_client->cl_net);
1259 	if (!error)
1260 		goto init_server;
1261 #endif	/* IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA) */
1262 
1263 	rpc_set_port(&ctx->nfs_server.address, NFS_PORT);
1264 	error = nfs4_set_client(server,
1265 				ctx->nfs_server.hostname,
1266 				&ctx->nfs_server.address,
1267 				ctx->nfs_server.addrlen,
1268 				parent_client->cl_ipaddr,
1269 				XPRT_TRANSPORT_TCP,
1270 				parent_server->client->cl_timeout,
1271 				parent_client->cl_mvops->minor_version,
1272 				parent_client->cl_nconnect,
1273 				parent_client->cl_max_connect,
1274 				parent_client->cl_net);
1275 	if (error < 0)
1276 		goto error;
1277 
1278 #if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
1279 init_server:
1280 #endif
1281 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout,
1282 					  ctx->selected_flavor);
1283 	if (error < 0)
1284 		goto error;
1285 
1286 	auth_probe = parent_server->auth_info.flavor_len < 1;
1287 
1288 	error = nfs4_server_common_setup(server, ctx->mntfh, auth_probe);
1289 	if (error < 0)
1290 		goto error;
1291 
1292 	return server;
1293 
1294 error:
1295 	nfs_free_server(server);
1296 	return ERR_PTR(error);
1297 }
1298 
1299 /*
1300  * Grab the destination's particulars, including lease expiry time.
1301  *
1302  * Returns zero if probe succeeded and retrieved FSID matches the FSID
1303  * we have cached.
1304  */
nfs_probe_destination(struct nfs_server * server)1305 static int nfs_probe_destination(struct nfs_server *server)
1306 {
1307 	struct inode *inode = d_inode(server->super->s_root);
1308 	struct nfs_fattr *fattr;
1309 	int error;
1310 
1311 	fattr = nfs_alloc_fattr();
1312 	if (fattr == NULL)
1313 		return -ENOMEM;
1314 
1315 	/* Sanity: the probe won't work if the destination server
1316 	 * does not recognize the migrated FH. */
1317 	error = nfs_probe_fsinfo(server, NFS_FH(inode), fattr);
1318 
1319 	nfs_free_fattr(fattr);
1320 	return error;
1321 }
1322 
1323 /**
1324  * nfs4_update_server - Move an nfs_server to a different nfs_client
1325  *
1326  * @server: represents FSID to be moved
1327  * @hostname: new end-point's hostname
1328  * @sap: new end-point's socket address
1329  * @salen: size of "sap"
1330  * @net: net namespace
1331  *
1332  * The nfs_server must be quiescent before this function is invoked.
1333  * Either its session is drained (NFSv4.1+), or its transport is
1334  * plugged and drained (NFSv4.0).
1335  *
1336  * Returns zero on success, or a negative errno value.
1337  */
nfs4_update_server(struct nfs_server * server,const char * hostname,struct sockaddr * sap,size_t salen,struct net * net)1338 int nfs4_update_server(struct nfs_server *server, const char *hostname,
1339 		       struct sockaddr *sap, size_t salen, struct net *net)
1340 {
1341 	struct nfs_client *clp = server->nfs_client;
1342 	struct rpc_clnt *clnt = server->client;
1343 	struct xprt_create xargs = {
1344 		.ident		= clp->cl_proto,
1345 		.net		= net,
1346 		.dstaddr	= sap,
1347 		.addrlen	= salen,
1348 		.servername	= hostname,
1349 	};
1350 	char buf[INET6_ADDRSTRLEN + 1];
1351 	struct sockaddr_storage address;
1352 	struct sockaddr *localaddr = (struct sockaddr *)&address;
1353 	int error;
1354 
1355 	error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
1356 	if (error != 0)
1357 		return error;
1358 
1359 	error = rpc_localaddr(clnt, localaddr, sizeof(address));
1360 	if (error != 0)
1361 		return error;
1362 
1363 	if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0)
1364 		return -EAFNOSUPPORT;
1365 
1366 	nfs_server_remove_lists(server);
1367 	set_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
1368 	error = nfs4_set_client(server, hostname, sap, salen, buf,
1369 				clp->cl_proto, clnt->cl_timeout,
1370 				clp->cl_minorversion,
1371 				clp->cl_nconnect, clp->cl_max_connect, net);
1372 	clear_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
1373 	if (error != 0) {
1374 		nfs_server_insert_lists(server);
1375 		return error;
1376 	}
1377 	nfs_put_client(clp);
1378 
1379 	if (server->nfs_client->cl_hostname == NULL) {
1380 		server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
1381 		if (server->nfs_client->cl_hostname == NULL)
1382 			return -ENOMEM;
1383 	}
1384 	nfs_server_insert_lists(server);
1385 
1386 	return nfs_probe_destination(server);
1387 }
1388