xref: /openbmc/linux/fs/nfs/nfs4client.c (revision 79f08d9e)
1 /*
2  * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
3  * Written by David Howells (dhowells@redhat.com)
4  */
5 #include <linux/module.h>
6 #include <linux/nfs_fs.h>
7 #include <linux/nfs_idmap.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 "internal.h"
14 #include "callback.h"
15 #include "delegation.h"
16 #include "nfs4session.h"
17 #include "pnfs.h"
18 #include "netns.h"
19 
20 #define NFSDBG_FACILITY		NFSDBG_CLIENT
21 
22 /*
23  * Get a unique NFSv4.0 callback identifier which will be used
24  * by the V4.0 callback service to lookup the nfs_client struct
25  */
26 static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
27 {
28 	int ret = 0;
29 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
30 
31 	if (clp->rpc_ops->version != 4 || minorversion != 0)
32 		return ret;
33 	idr_preload(GFP_KERNEL);
34 	spin_lock(&nn->nfs_client_lock);
35 	ret = idr_alloc(&nn->cb_ident_idr, clp, 0, 0, GFP_NOWAIT);
36 	if (ret >= 0)
37 		clp->cl_cb_ident = ret;
38 	spin_unlock(&nn->nfs_client_lock);
39 	idr_preload_end();
40 	return ret < 0 ? ret : 0;
41 }
42 
43 #ifdef CONFIG_NFS_V4_1
44 /**
45  * Per auth flavor data server rpc clients
46  */
47 struct nfs4_ds_server {
48 	struct list_head	list;   /* ds_clp->cl_ds_clients */
49 	struct rpc_clnt		*rpc_clnt;
50 };
51 
52 /**
53  * Common lookup case for DS I/O
54  */
55 static struct nfs4_ds_server *
56 nfs4_find_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
57 {
58 	struct nfs4_ds_server *dss;
59 
60 	rcu_read_lock();
61 	list_for_each_entry_rcu(dss, &ds_clp->cl_ds_clients, list) {
62 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
63 			continue;
64 		goto out;
65 	}
66 	dss = NULL;
67 out:
68 	rcu_read_unlock();
69 	return dss;
70 }
71 
72 static struct nfs4_ds_server *
73 nfs4_add_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor,
74 			   struct nfs4_ds_server *new)
75 {
76 	struct nfs4_ds_server *dss;
77 
78 	spin_lock(&ds_clp->cl_lock);
79 	list_for_each_entry(dss, &ds_clp->cl_ds_clients, list) {
80 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
81 			continue;
82 		goto out;
83 	}
84 	if (new)
85 		list_add_rcu(&new->list, &ds_clp->cl_ds_clients);
86 	dss = new;
87 out:
88 	spin_unlock(&ds_clp->cl_lock); /* need some lock to protect list */
89 	return dss;
90 }
91 
92 static struct nfs4_ds_server *
93 nfs4_alloc_ds_server(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
94 {
95 	struct nfs4_ds_server *dss;
96 
97 	dss = kmalloc(sizeof(*dss), GFP_NOFS);
98 	if (dss == NULL)
99 		return ERR_PTR(-ENOMEM);
100 
101 	dss->rpc_clnt = rpc_clone_client_set_auth(ds_clp->cl_rpcclient, flavor);
102 	if (IS_ERR(dss->rpc_clnt)) {
103 		int err = PTR_ERR(dss->rpc_clnt);
104 		kfree (dss);
105 		return ERR_PTR(err);
106 	}
107 	INIT_LIST_HEAD(&dss->list);
108 
109 	return dss;
110 }
111 
112 static void
113 nfs4_free_ds_server(struct nfs4_ds_server *dss)
114 {
115 	rpc_release_client(dss->rpc_clnt);
116 	kfree(dss);
117 }
118 
119 /**
120 * Find or create a DS rpc client with th MDS server rpc client auth flavor
121 * in the nfs_client cl_ds_clients list.
122 */
123 struct rpc_clnt *
124 nfs4_find_or_create_ds_client(struct nfs_client *ds_clp, struct inode *inode)
125 {
126 	struct nfs4_ds_server *dss, *new;
127 	rpc_authflavor_t flavor = NFS_SERVER(inode)->client->cl_auth->au_flavor;
128 
129 	dss = nfs4_find_ds_client(ds_clp, flavor);
130 	if (dss != NULL)
131 		goto out;
132 	new = nfs4_alloc_ds_server(ds_clp, flavor);
133 	if (IS_ERR(new))
134 		return ERR_CAST(new);
135 	dss = nfs4_add_ds_client(ds_clp, flavor, new);
136 	if (dss != new)
137 		nfs4_free_ds_server(new);
138 out:
139 	return dss->rpc_clnt;
140 }
141 EXPORT_SYMBOL_GPL(nfs4_find_or_create_ds_client);
142 
143 static void
144 nfs4_shutdown_ds_clients(struct nfs_client *clp)
145 {
146 	struct nfs4_ds_server *dss;
147 	LIST_HEAD(shutdown_list);
148 
149 	while (!list_empty(&clp->cl_ds_clients)) {
150 		dss = list_entry(clp->cl_ds_clients.next,
151 					struct nfs4_ds_server, list);
152 		list_del(&dss->list);
153 		rpc_shutdown_client(dss->rpc_clnt);
154 		kfree (dss);
155 	}
156 }
157 
158 void nfs41_shutdown_client(struct nfs_client *clp)
159 {
160 	if (nfs4_has_session(clp)) {
161 		nfs4_shutdown_ds_clients(clp);
162 		nfs4_destroy_session(clp->cl_session);
163 		nfs4_destroy_clientid(clp);
164 	}
165 
166 }
167 #endif	/* CONFIG_NFS_V4_1 */
168 
169 void nfs40_shutdown_client(struct nfs_client *clp)
170 {
171 	if (clp->cl_slot_tbl) {
172 		nfs4_release_slot_table(clp->cl_slot_tbl);
173 		kfree(clp->cl_slot_tbl);
174 	}
175 }
176 
177 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
178 {
179 	int err;
180 	struct nfs_client *clp = nfs_alloc_client(cl_init);
181 	if (IS_ERR(clp))
182 		return clp;
183 
184 	err = nfs_get_cb_ident_idr(clp, cl_init->minorversion);
185 	if (err)
186 		goto error;
187 
188 	if (cl_init->minorversion > NFS4_MAX_MINOR_VERSION) {
189 		err = -EINVAL;
190 		goto error;
191 	}
192 
193 	spin_lock_init(&clp->cl_lock);
194 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
195 	INIT_LIST_HEAD(&clp->cl_ds_clients);
196 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
197 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
198 	clp->cl_minorversion = cl_init->minorversion;
199 	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
200 	clp->cl_mig_gen = 1;
201 	return clp;
202 
203 error:
204 	nfs_free_client(clp);
205 	return ERR_PTR(err);
206 }
207 
208 /*
209  * Destroy the NFS4 callback service
210  */
211 static void nfs4_destroy_callback(struct nfs_client *clp)
212 {
213 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
214 		nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
215 }
216 
217 static void nfs4_shutdown_client(struct nfs_client *clp)
218 {
219 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
220 		nfs4_kill_renewd(clp);
221 	clp->cl_mvops->shutdown_client(clp);
222 	nfs4_destroy_callback(clp);
223 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
224 		nfs_idmap_delete(clp);
225 
226 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
227 	kfree(clp->cl_serverowner);
228 	kfree(clp->cl_serverscope);
229 	kfree(clp->cl_implid);
230 }
231 
232 void nfs4_free_client(struct nfs_client *clp)
233 {
234 	nfs4_shutdown_client(clp);
235 	nfs_free_client(clp);
236 }
237 
238 /*
239  * Initialize the NFS4 callback service
240  */
241 static int nfs4_init_callback(struct nfs_client *clp)
242 {
243 	int error;
244 
245 	if (clp->rpc_ops->version == 4) {
246 		struct rpc_xprt *xprt;
247 
248 		xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
249 
250 		if (nfs4_has_session(clp)) {
251 			error = xprt_setup_backchannel(xprt,
252 						NFS41_BC_MIN_CALLBACKS);
253 			if (error < 0)
254 				return error;
255 		}
256 
257 		error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
258 		if (error < 0) {
259 			dprintk("%s: failed to start callback. Error = %d\n",
260 				__func__, error);
261 			return error;
262 		}
263 		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
264 	}
265 	return 0;
266 }
267 
268 /**
269  * nfs40_init_client - nfs_client initialization tasks for NFSv4.0
270  * @clp - nfs_client to initialize
271  *
272  * Returns zero on success, or a negative errno if some error occurred.
273  */
274 int nfs40_init_client(struct nfs_client *clp)
275 {
276 	struct nfs4_slot_table *tbl;
277 	int ret;
278 
279 	tbl = kzalloc(sizeof(*tbl), GFP_NOFS);
280 	if (tbl == NULL)
281 		return -ENOMEM;
282 
283 	ret = nfs4_setup_slot_table(tbl, NFS4_MAX_SLOT_TABLE,
284 					"NFSv4.0 transport Slot table");
285 	if (ret) {
286 		kfree(tbl);
287 		return ret;
288 	}
289 
290 	clp->cl_slot_tbl = tbl;
291 	return 0;
292 }
293 
294 #if defined(CONFIG_NFS_V4_1)
295 
296 /**
297  * nfs41_init_client - nfs_client initialization tasks for NFSv4.1+
298  * @clp - nfs_client to initialize
299  *
300  * Returns zero on success, or a negative errno if some error occurred.
301  */
302 int nfs41_init_client(struct nfs_client *clp)
303 {
304 	struct nfs4_session *session = NULL;
305 
306 	/*
307 	 * Create the session and mark it expired.
308 	 * When a SEQUENCE operation encounters the expired session
309 	 * it will do session recovery to initialize it.
310 	 */
311 	session = nfs4_alloc_session(clp);
312 	if (!session)
313 		return -ENOMEM;
314 
315 	clp->cl_session = session;
316 
317 	/*
318 	 * The create session reply races with the server back
319 	 * channel probe. Mark the client NFS_CS_SESSION_INITING
320 	 * so that the client back channel can find the
321 	 * nfs_client struct
322 	 */
323 	nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
324 	return 0;
325 }
326 
327 #endif	/* CONFIG_NFS_V4_1 */
328 
329 /*
330  * Initialize the minor version specific parts of an NFS4 client record
331  */
332 static int nfs4_init_client_minor_version(struct nfs_client *clp)
333 {
334 	int ret;
335 
336 	ret = clp->cl_mvops->init_client(clp);
337 	if (ret)
338 		return ret;
339 	return nfs4_init_callback(clp);
340 }
341 
342 /**
343  * nfs4_init_client - Initialise an NFS4 client record
344  *
345  * @clp: nfs_client to initialise
346  * @timeparms: timeout parameters for underlying RPC transport
347  * @ip_addr: callback IP address in presentation format
348  * @authflavor: authentication flavor for underlying RPC transport
349  *
350  * Returns pointer to an NFS client, or an ERR_PTR value.
351  */
352 struct nfs_client *nfs4_init_client(struct nfs_client *clp,
353 				    const struct rpc_timeout *timeparms,
354 				    const char *ip_addr)
355 {
356 	char buf[INET6_ADDRSTRLEN + 1];
357 	struct nfs_client *old;
358 	int error;
359 
360 	if (clp->cl_cons_state == NFS_CS_READY) {
361 		/* the client is initialised already */
362 		dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
363 		return clp;
364 	}
365 
366 	/* Check NFS protocol revision and initialize RPC op vector */
367 	clp->rpc_ops = &nfs_v4_clientops;
368 
369 	if (clp->cl_minorversion != 0)
370 		__set_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags);
371 	__set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
372 	__set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags);
373 	error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_GSS_KRB5I);
374 	if (error == -EINVAL)
375 		error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_UNIX);
376 	if (error < 0)
377 		goto error;
378 
379 	/* If no clientaddr= option was specified, find a usable cb address */
380 	if (ip_addr == NULL) {
381 		struct sockaddr_storage cb_addr;
382 		struct sockaddr *sap = (struct sockaddr *)&cb_addr;
383 
384 		error = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
385 		if (error < 0)
386 			goto error;
387 		error = rpc_ntop(sap, buf, sizeof(buf));
388 		if (error < 0)
389 			goto error;
390 		ip_addr = (const char *)buf;
391 	}
392 	strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
393 
394 	error = nfs_idmap_new(clp);
395 	if (error < 0) {
396 		dprintk("%s: failed to create idmapper. Error = %d\n",
397 			__func__, error);
398 		goto error;
399 	}
400 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
401 
402 	error = nfs4_init_client_minor_version(clp);
403 	if (error < 0)
404 		goto error;
405 
406 	if (!nfs4_has_session(clp))
407 		nfs_mark_client_ready(clp, NFS_CS_READY);
408 
409 	error = nfs4_discover_server_trunking(clp, &old);
410 	if (error < 0)
411 		goto error;
412 	nfs_put_client(clp);
413 	if (clp != old) {
414 		clp->cl_preserve_clid = true;
415 		clp = old;
416 	}
417 
418 	return clp;
419 
420 error:
421 	nfs_mark_client_ready(clp, error);
422 	nfs_put_client(clp);
423 	dprintk("<-- nfs4_init_client() = xerror %d\n", error);
424 	return ERR_PTR(error);
425 }
426 
427 /*
428  * SETCLIENTID just did a callback update with the callback ident in
429  * "drop," but server trunking discovery claims "drop" and "keep" are
430  * actually the same server.  Swap the callback IDs so that "keep"
431  * will continue to use the callback ident the server now knows about,
432  * and so that "keep"'s original callback ident is destroyed when
433  * "drop" is freed.
434  */
435 static void nfs4_swap_callback_idents(struct nfs_client *keep,
436 				      struct nfs_client *drop)
437 {
438 	struct nfs_net *nn = net_generic(keep->cl_net, nfs_net_id);
439 	unsigned int save = keep->cl_cb_ident;
440 
441 	if (keep->cl_cb_ident == drop->cl_cb_ident)
442 		return;
443 
444 	dprintk("%s: keeping callback ident %u and dropping ident %u\n",
445 		__func__, keep->cl_cb_ident, drop->cl_cb_ident);
446 
447 	spin_lock(&nn->nfs_client_lock);
448 
449 	idr_replace(&nn->cb_ident_idr, keep, drop->cl_cb_ident);
450 	keep->cl_cb_ident = drop->cl_cb_ident;
451 
452 	idr_replace(&nn->cb_ident_idr, drop, save);
453 	drop->cl_cb_ident = save;
454 
455 	spin_unlock(&nn->nfs_client_lock);
456 }
457 
458 /**
459  * nfs40_walk_client_list - Find server that recognizes a client ID
460  *
461  * @new: nfs_client with client ID to test
462  * @result: OUT: found nfs_client, or new
463  * @cred: credential to use for trunking test
464  *
465  * Returns zero, a negative errno, or a negative NFS4ERR status.
466  * If zero is returned, an nfs_client pointer is planted in "result."
467  *
468  * NB: nfs40_walk_client_list() relies on the new nfs_client being
469  *     the last nfs_client on the list.
470  */
471 int nfs40_walk_client_list(struct nfs_client *new,
472 			   struct nfs_client **result,
473 			   struct rpc_cred *cred)
474 {
475 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
476 	struct nfs_client *pos, *prev = NULL;
477 	struct nfs4_setclientid_res clid = {
478 		.clientid	= new->cl_clientid,
479 		.confirm	= new->cl_confirm,
480 	};
481 	int status = -NFS4ERR_STALE_CLIENTID;
482 
483 	spin_lock(&nn->nfs_client_lock);
484 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
485 		/* If "pos" isn't marked ready, we can't trust the
486 		 * remaining fields in "pos" */
487 		if (pos->cl_cons_state > NFS_CS_READY) {
488 			atomic_inc(&pos->cl_count);
489 			spin_unlock(&nn->nfs_client_lock);
490 
491 			if (prev)
492 				nfs_put_client(prev);
493 			prev = pos;
494 
495 			status = nfs_wait_client_init_complete(pos);
496 			spin_lock(&nn->nfs_client_lock);
497 			if (status < 0)
498 				continue;
499 		}
500 		if (pos->cl_cons_state != NFS_CS_READY)
501 			continue;
502 
503 		if (pos->rpc_ops != new->rpc_ops)
504 			continue;
505 
506 		if (pos->cl_proto != new->cl_proto)
507 			continue;
508 
509 		if (pos->cl_minorversion != new->cl_minorversion)
510 			continue;
511 
512 		if (pos->cl_clientid != new->cl_clientid)
513 			continue;
514 
515 		atomic_inc(&pos->cl_count);
516 		spin_unlock(&nn->nfs_client_lock);
517 
518 		if (prev)
519 			nfs_put_client(prev);
520 		prev = pos;
521 
522 		status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
523 		switch (status) {
524 		case -NFS4ERR_STALE_CLIENTID:
525 			break;
526 		case 0:
527 			nfs4_swap_callback_idents(pos, new);
528 
529 			prev = NULL;
530 			*result = pos;
531 			dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
532 				__func__, pos, atomic_read(&pos->cl_count));
533 		default:
534 			goto out;
535 		}
536 
537 		spin_lock(&nn->nfs_client_lock);
538 	}
539 	spin_unlock(&nn->nfs_client_lock);
540 
541 	/* No match found. The server lost our clientid */
542 out:
543 	if (prev)
544 		nfs_put_client(prev);
545 	dprintk("NFS: <-- %s status = %d\n", __func__, status);
546 	return status;
547 }
548 
549 #ifdef CONFIG_NFS_V4_1
550 /*
551  * Returns true if the client IDs match
552  */
553 static bool nfs4_match_clientids(struct nfs_client *a, struct nfs_client *b)
554 {
555 	if (a->cl_clientid != b->cl_clientid) {
556 		dprintk("NFS: --> %s client ID %llx does not match %llx\n",
557 			__func__, a->cl_clientid, b->cl_clientid);
558 		return false;
559 	}
560 	dprintk("NFS: --> %s client ID %llx matches %llx\n",
561 		__func__, a->cl_clientid, b->cl_clientid);
562 	return true;
563 }
564 
565 /*
566  * Returns true if the server owners match
567  */
568 static bool
569 nfs4_match_serverowners(struct nfs_client *a, struct nfs_client *b)
570 {
571 	struct nfs41_server_owner *o1 = a->cl_serverowner;
572 	struct nfs41_server_owner *o2 = b->cl_serverowner;
573 
574 	if (o1->minor_id != o2->minor_id) {
575 		dprintk("NFS: --> %s server owner minor IDs do not match\n",
576 			__func__);
577 		return false;
578 	}
579 
580 	if (o1->major_id_sz != o2->major_id_sz)
581 		goto out_major_mismatch;
582 	if (memcmp(o1->major_id, o2->major_id, o1->major_id_sz) != 0)
583 		goto out_major_mismatch;
584 
585 	dprintk("NFS: --> %s server owners match\n", __func__);
586 	return true;
587 
588 out_major_mismatch:
589 	dprintk("NFS: --> %s server owner major IDs do not match\n",
590 		__func__);
591 	return false;
592 }
593 
594 /**
595  * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
596  *
597  * @new: nfs_client with client ID to test
598  * @result: OUT: found nfs_client, or new
599  * @cred: credential to use for trunking test
600  *
601  * Returns zero, a negative errno, or a negative NFS4ERR status.
602  * If zero is returned, an nfs_client pointer is planted in "result."
603  *
604  * NB: nfs41_walk_client_list() relies on the new nfs_client being
605  *     the last nfs_client on the list.
606  */
607 int nfs41_walk_client_list(struct nfs_client *new,
608 			   struct nfs_client **result,
609 			   struct rpc_cred *cred)
610 {
611 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
612 	struct nfs_client *pos, *prev = NULL;
613 	int status = -NFS4ERR_STALE_CLIENTID;
614 
615 	spin_lock(&nn->nfs_client_lock);
616 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
617 		/* If "pos" isn't marked ready, we can't trust the
618 		 * remaining fields in "pos", especially the client
619 		 * ID and serverowner fields.  Wait for CREATE_SESSION
620 		 * to finish. */
621 		if (pos->cl_cons_state > NFS_CS_READY) {
622 			atomic_inc(&pos->cl_count);
623 			spin_unlock(&nn->nfs_client_lock);
624 
625 			if (prev)
626 				nfs_put_client(prev);
627 			prev = pos;
628 
629 			status = nfs_wait_client_init_complete(pos);
630 			if (status == 0) {
631 				nfs4_schedule_lease_recovery(pos);
632 				status = nfs4_wait_clnt_recover(pos);
633 			}
634 			spin_lock(&nn->nfs_client_lock);
635 			if (status < 0)
636 				continue;
637 		}
638 		if (pos->cl_cons_state != NFS_CS_READY)
639 			continue;
640 
641 		if (pos->rpc_ops != new->rpc_ops)
642 			continue;
643 
644 		if (pos->cl_proto != new->cl_proto)
645 			continue;
646 
647 		if (pos->cl_minorversion != new->cl_minorversion)
648 			continue;
649 
650 		if (!nfs4_match_clientids(pos, new))
651 			continue;
652 
653 		if (!nfs4_match_serverowners(pos, new))
654 			continue;
655 
656 		atomic_inc(&pos->cl_count);
657 		*result = pos;
658 		status = 0;
659 		dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
660 			__func__, pos, atomic_read(&pos->cl_count));
661 		break;
662 	}
663 
664 	/* No matching nfs_client found. */
665 	spin_unlock(&nn->nfs_client_lock);
666 	dprintk("NFS: <-- %s status = %d\n", __func__, status);
667 	if (prev)
668 		nfs_put_client(prev);
669 	return status;
670 }
671 #endif	/* CONFIG_NFS_V4_1 */
672 
673 static void nfs4_destroy_server(struct nfs_server *server)
674 {
675 	nfs_server_return_all_delegations(server);
676 	unset_pnfs_layoutdriver(server);
677 	nfs4_purge_state_owners(server);
678 }
679 
680 /*
681  * NFSv4.0 callback thread helper
682  *
683  * Find a client by callback identifier
684  */
685 struct nfs_client *
686 nfs4_find_client_ident(struct net *net, int cb_ident)
687 {
688 	struct nfs_client *clp;
689 	struct nfs_net *nn = net_generic(net, nfs_net_id);
690 
691 	spin_lock(&nn->nfs_client_lock);
692 	clp = idr_find(&nn->cb_ident_idr, cb_ident);
693 	if (clp)
694 		atomic_inc(&clp->cl_count);
695 	spin_unlock(&nn->nfs_client_lock);
696 	return clp;
697 }
698 
699 #if defined(CONFIG_NFS_V4_1)
700 /* Common match routine for v4.0 and v4.1 callback services */
701 static bool nfs4_cb_match_client(const struct sockaddr *addr,
702 		struct nfs_client *clp, u32 minorversion)
703 {
704 	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
705 
706 	/* Don't match clients that failed to initialise */
707 	if (!(clp->cl_cons_state == NFS_CS_READY ||
708 	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
709 		return false;
710 
711 	smp_rmb();
712 
713 	/* Match the version and minorversion */
714 	if (clp->rpc_ops->version != 4 ||
715 	    clp->cl_minorversion != minorversion)
716 		return false;
717 
718 	/* Match only the IP address, not the port number */
719 	if (!nfs_sockaddr_match_ipaddr(addr, clap))
720 		return false;
721 
722 	return true;
723 }
724 
725 /*
726  * NFSv4.1 callback thread helper
727  * For CB_COMPOUND calls, find a client by IP address, protocol version,
728  * minorversion, and sessionID
729  *
730  * Returns NULL if no such client
731  */
732 struct nfs_client *
733 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
734 			   struct nfs4_sessionid *sid, u32 minorversion)
735 {
736 	struct nfs_client *clp;
737 	struct nfs_net *nn = net_generic(net, nfs_net_id);
738 
739 	spin_lock(&nn->nfs_client_lock);
740 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
741 		if (nfs4_cb_match_client(addr, clp, minorversion) == false)
742 			continue;
743 
744 		if (!nfs4_has_session(clp))
745 			continue;
746 
747 		/* Match sessionid*/
748 		if (memcmp(clp->cl_session->sess_id.data,
749 		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
750 			continue;
751 
752 		atomic_inc(&clp->cl_count);
753 		spin_unlock(&nn->nfs_client_lock);
754 		return clp;
755 	}
756 	spin_unlock(&nn->nfs_client_lock);
757 	return NULL;
758 }
759 
760 #else /* CONFIG_NFS_V4_1 */
761 
762 struct nfs_client *
763 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
764 			   struct nfs4_sessionid *sid, u32 minorversion)
765 {
766 	return NULL;
767 }
768 #endif /* CONFIG_NFS_V4_1 */
769 
770 /*
771  * Set up an NFS4 client
772  */
773 static int nfs4_set_client(struct nfs_server *server,
774 		const char *hostname,
775 		const struct sockaddr *addr,
776 		const size_t addrlen,
777 		const char *ip_addr,
778 		rpc_authflavor_t authflavour,
779 		int proto, const struct rpc_timeout *timeparms,
780 		u32 minorversion, struct net *net)
781 {
782 	struct nfs_client_initdata cl_init = {
783 		.hostname = hostname,
784 		.addr = addr,
785 		.addrlen = addrlen,
786 		.nfs_mod = &nfs_v4,
787 		.proto = proto,
788 		.minorversion = minorversion,
789 		.net = net,
790 	};
791 	struct nfs_client *clp;
792 	int error;
793 
794 	dprintk("--> nfs4_set_client()\n");
795 
796 	if (server->flags & NFS_MOUNT_NORESVPORT)
797 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
798 	if (server->options & NFS_OPTION_MIGRATION)
799 		set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
800 
801 	/* Allocate or find a client reference we can use */
802 	clp = nfs_get_client(&cl_init, timeparms, ip_addr, authflavour);
803 	if (IS_ERR(clp)) {
804 		error = PTR_ERR(clp);
805 		goto error;
806 	}
807 
808 	/*
809 	 * Query for the lease time on clientid setup or renewal
810 	 *
811 	 * Note that this will be set on nfs_clients that were created
812 	 * only for the DS role and did not set this bit, but now will
813 	 * serve a dual role.
814 	 */
815 	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
816 
817 	server->nfs_client = clp;
818 	dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
819 	return 0;
820 error:
821 	dprintk("<-- nfs4_set_client() = xerror %d\n", error);
822 	return error;
823 }
824 
825 /*
826  * Set up a pNFS Data Server client.
827  *
828  * Return any existing nfs_client that matches server address,port,version
829  * and minorversion.
830  *
831  * For a new nfs_client, use a soft mount (default), a low retrans and a
832  * low timeout interval so that if a connection is lost, we retry through
833  * the MDS.
834  */
835 struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
836 		const struct sockaddr *ds_addr, int ds_addrlen,
837 		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans)
838 {
839 	struct nfs_client_initdata cl_init = {
840 		.addr = ds_addr,
841 		.addrlen = ds_addrlen,
842 		.nfs_mod = &nfs_v4,
843 		.proto = ds_proto,
844 		.minorversion = mds_clp->cl_minorversion,
845 		.net = mds_clp->cl_net,
846 	};
847 	struct rpc_timeout ds_timeout;
848 	struct nfs_client *clp;
849 
850 	/*
851 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
852 	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
853 	 * (section 13.1 RFC 5661).
854 	 */
855 	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
856 	clp = nfs_get_client(&cl_init, &ds_timeout, mds_clp->cl_ipaddr,
857 			     mds_clp->cl_rpcclient->cl_auth->au_flavor);
858 
859 	dprintk("<-- %s %p\n", __func__, clp);
860 	return clp;
861 }
862 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
863 
864 /*
865  * Session has been established, and the client marked ready.
866  * Set the mount rsize and wsize with negotiated fore channel
867  * attributes which will be bound checked in nfs_server_set_fsinfo.
868  */
869 static void nfs4_session_set_rwsize(struct nfs_server *server)
870 {
871 #ifdef CONFIG_NFS_V4_1
872 	struct nfs4_session *sess;
873 	u32 server_resp_sz;
874 	u32 server_rqst_sz;
875 
876 	if (!nfs4_has_session(server->nfs_client))
877 		return;
878 	sess = server->nfs_client->cl_session;
879 	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
880 	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
881 
882 	if (server->rsize > server_resp_sz)
883 		server->rsize = server_resp_sz;
884 	if (server->wsize > server_rqst_sz)
885 		server->wsize = server_rqst_sz;
886 #endif /* CONFIG_NFS_V4_1 */
887 }
888 
889 static int nfs4_server_common_setup(struct nfs_server *server,
890 		struct nfs_fh *mntfh, bool auth_probe)
891 {
892 	struct nfs_fattr *fattr;
893 	int error;
894 
895 	/* data servers support only a subset of NFSv4.1 */
896 	if (is_ds_only_client(server->nfs_client))
897 		return -EPROTONOSUPPORT;
898 
899 	fattr = nfs_alloc_fattr();
900 	if (fattr == NULL)
901 		return -ENOMEM;
902 
903 	/* We must ensure the session is initialised first */
904 	error = nfs4_init_session(server->nfs_client);
905 	if (error < 0)
906 		goto out;
907 
908 	/* Set the basic capabilities */
909 	server->caps |= server->nfs_client->cl_mvops->init_caps;
910 	if (server->flags & NFS_MOUNT_NORDIRPLUS)
911 			server->caps &= ~NFS_CAP_READDIRPLUS;
912 	/*
913 	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
914 	 * authentication.
915 	 */
916 	if (nfs4_disable_idmapping &&
917 			server->client->cl_auth->au_flavor == RPC_AUTH_UNIX)
918 		server->caps |= NFS_CAP_UIDGID_NOMAP;
919 
920 
921 	/* Probe the root fh to retrieve its FSID and filehandle */
922 	error = nfs4_get_rootfh(server, mntfh, auth_probe);
923 	if (error < 0)
924 		goto out;
925 
926 	dprintk("Server FSID: %llx:%llx\n",
927 			(unsigned long long) server->fsid.major,
928 			(unsigned long long) server->fsid.minor);
929 	nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
930 
931 	nfs4_session_set_rwsize(server);
932 
933 	error = nfs_probe_fsinfo(server, mntfh, fattr);
934 	if (error < 0)
935 		goto out;
936 
937 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
938 		server->namelen = NFS4_MAXNAMLEN;
939 
940 	nfs_server_insert_lists(server);
941 	server->mount_time = jiffies;
942 	server->destroy = nfs4_destroy_server;
943 out:
944 	nfs_free_fattr(fattr);
945 	return error;
946 }
947 
948 /*
949  * Create a version 4 volume record
950  */
951 static int nfs4_init_server(struct nfs_server *server,
952 		struct nfs_parsed_mount_data *data)
953 {
954 	struct rpc_timeout timeparms;
955 	int error;
956 
957 	dprintk("--> nfs4_init_server()\n");
958 
959 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
960 			data->timeo, data->retrans);
961 
962 	/* Initialise the client representation from the mount data */
963 	server->flags = data->flags;
964 	server->options = data->options;
965 	server->auth_info = data->auth_info;
966 
967 	/* Use the first specified auth flavor. If this flavor isn't
968 	 * allowed by the server, use the SECINFO path to try the
969 	 * other specified flavors */
970 	if (data->auth_info.flavor_len >= 1)
971 		data->selected_flavor = data->auth_info.flavors[0];
972 	else
973 		data->selected_flavor = RPC_AUTH_UNIX;
974 
975 	/* Get a client record */
976 	error = nfs4_set_client(server,
977 			data->nfs_server.hostname,
978 			(const struct sockaddr *)&data->nfs_server.address,
979 			data->nfs_server.addrlen,
980 			data->client_address,
981 			data->selected_flavor,
982 			data->nfs_server.protocol,
983 			&timeparms,
984 			data->minorversion,
985 			data->net);
986 	if (error < 0)
987 		goto error;
988 
989 	if (data->rsize)
990 		server->rsize = nfs_block_size(data->rsize, NULL);
991 	if (data->wsize)
992 		server->wsize = nfs_block_size(data->wsize, NULL);
993 
994 	server->acregmin = data->acregmin * HZ;
995 	server->acregmax = data->acregmax * HZ;
996 	server->acdirmin = data->acdirmin * HZ;
997 	server->acdirmax = data->acdirmax * HZ;
998 
999 	server->port = data->nfs_server.port;
1000 
1001 	error = nfs_init_server_rpcclient(server, &timeparms,
1002 					  data->selected_flavor);
1003 
1004 error:
1005 	/* Done */
1006 	dprintk("<-- nfs4_init_server() = %d\n", error);
1007 	return error;
1008 }
1009 
1010 /*
1011  * Create a version 4 volume record
1012  * - keyed on server and FSID
1013  */
1014 /*struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
1015 				      struct nfs_fh *mntfh)*/
1016 struct nfs_server *nfs4_create_server(struct nfs_mount_info *mount_info,
1017 				      struct nfs_subversion *nfs_mod)
1018 {
1019 	struct nfs_server *server;
1020 	bool auth_probe;
1021 	int error;
1022 
1023 	dprintk("--> nfs4_create_server()\n");
1024 
1025 	server = nfs_alloc_server();
1026 	if (!server)
1027 		return ERR_PTR(-ENOMEM);
1028 
1029 	auth_probe = mount_info->parsed->auth_info.flavor_len < 1;
1030 
1031 	/* set up the general RPC client */
1032 	error = nfs4_init_server(server, mount_info->parsed);
1033 	if (error < 0)
1034 		goto error;
1035 
1036 	error = nfs4_server_common_setup(server, mount_info->mntfh, auth_probe);
1037 	if (error < 0)
1038 		goto error;
1039 
1040 	dprintk("<-- nfs4_create_server() = %p\n", server);
1041 	return server;
1042 
1043 error:
1044 	nfs_free_server(server);
1045 	dprintk("<-- nfs4_create_server() = error %d\n", error);
1046 	return ERR_PTR(error);
1047 }
1048 
1049 /*
1050  * Create an NFS4 referral server record
1051  */
1052 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
1053 					       struct nfs_fh *mntfh)
1054 {
1055 	struct nfs_client *parent_client;
1056 	struct nfs_server *server, *parent_server;
1057 	bool auth_probe;
1058 	int error;
1059 
1060 	dprintk("--> nfs4_create_referral_server()\n");
1061 
1062 	server = nfs_alloc_server();
1063 	if (!server)
1064 		return ERR_PTR(-ENOMEM);
1065 
1066 	parent_server = NFS_SB(data->sb);
1067 	parent_client = parent_server->nfs_client;
1068 
1069 	/* Initialise the client representation from the parent server */
1070 	nfs_server_copy_userdata(server, parent_server);
1071 
1072 	/* Get a client representation.
1073 	 * Note: NFSv4 always uses TCP, */
1074 	error = nfs4_set_client(server, data->hostname,
1075 				data->addr,
1076 				data->addrlen,
1077 				parent_client->cl_ipaddr,
1078 				data->authflavor,
1079 				rpc_protocol(parent_server->client),
1080 				parent_server->client->cl_timeout,
1081 				parent_client->cl_mvops->minor_version,
1082 				parent_client->cl_net);
1083 	if (error < 0)
1084 		goto error;
1085 
1086 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor);
1087 	if (error < 0)
1088 		goto error;
1089 
1090 	auth_probe = parent_server->auth_info.flavor_len < 1;
1091 
1092 	error = nfs4_server_common_setup(server, mntfh, auth_probe);
1093 	if (error < 0)
1094 		goto error;
1095 
1096 	dprintk("<-- nfs_create_referral_server() = %p\n", server);
1097 	return server;
1098 
1099 error:
1100 	nfs_free_server(server);
1101 	dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
1102 	return ERR_PTR(error);
1103 }
1104 
1105 /*
1106  * Grab the destination's particulars, including lease expiry time.
1107  *
1108  * Returns zero if probe succeeded and retrieved FSID matches the FSID
1109  * we have cached.
1110  */
1111 static int nfs_probe_destination(struct nfs_server *server)
1112 {
1113 	struct inode *inode = server->super->s_root->d_inode;
1114 	struct nfs_fattr *fattr;
1115 	int error;
1116 
1117 	fattr = nfs_alloc_fattr();
1118 	if (fattr == NULL)
1119 		return -ENOMEM;
1120 
1121 	/* Sanity: the probe won't work if the destination server
1122 	 * does not recognize the migrated FH. */
1123 	error = nfs_probe_fsinfo(server, NFS_FH(inode), fattr);
1124 
1125 	nfs_free_fattr(fattr);
1126 	return error;
1127 }
1128 
1129 /**
1130  * nfs4_update_server - Move an nfs_server to a different nfs_client
1131  *
1132  * @server: represents FSID to be moved
1133  * @hostname: new end-point's hostname
1134  * @sap: new end-point's socket address
1135  * @salen: size of "sap"
1136  *
1137  * The nfs_server must be quiescent before this function is invoked.
1138  * Either its session is drained (NFSv4.1+), or its transport is
1139  * plugged and drained (NFSv4.0).
1140  *
1141  * Returns zero on success, or a negative errno value.
1142  */
1143 int nfs4_update_server(struct nfs_server *server, const char *hostname,
1144 		       struct sockaddr *sap, size_t salen)
1145 {
1146 	struct nfs_client *clp = server->nfs_client;
1147 	struct rpc_clnt *clnt = server->client;
1148 	struct xprt_create xargs = {
1149 		.ident		= clp->cl_proto,
1150 		.net		= &init_net,
1151 		.dstaddr	= sap,
1152 		.addrlen	= salen,
1153 		.servername	= hostname,
1154 	};
1155 	char buf[INET6_ADDRSTRLEN + 1];
1156 	struct sockaddr_storage address;
1157 	struct sockaddr *localaddr = (struct sockaddr *)&address;
1158 	int error;
1159 
1160 	dprintk("--> %s: move FSID %llx:%llx to \"%s\")\n", __func__,
1161 			(unsigned long long)server->fsid.major,
1162 			(unsigned long long)server->fsid.minor,
1163 			hostname);
1164 
1165 	error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
1166 	if (error != 0) {
1167 		dprintk("<-- %s(): rpc_switch_client_transport returned %d\n",
1168 			__func__, error);
1169 		goto out;
1170 	}
1171 
1172 	error = rpc_localaddr(clnt, localaddr, sizeof(address));
1173 	if (error != 0) {
1174 		dprintk("<-- %s(): rpc_localaddr returned %d\n",
1175 			__func__, error);
1176 		goto out;
1177 	}
1178 
1179 	error = -EAFNOSUPPORT;
1180 	if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0) {
1181 		dprintk("<-- %s(): rpc_ntop returned %d\n",
1182 			__func__, error);
1183 		goto out;
1184 	}
1185 
1186 	nfs_server_remove_lists(server);
1187 	error = nfs4_set_client(server, hostname, sap, salen, buf,
1188 				clp->cl_rpcclient->cl_auth->au_flavor,
1189 				clp->cl_proto, clnt->cl_timeout,
1190 				clp->cl_minorversion, clp->cl_net);
1191 	nfs_put_client(clp);
1192 	if (error != 0) {
1193 		nfs_server_insert_lists(server);
1194 		dprintk("<-- %s(): nfs4_set_client returned %d\n",
1195 			__func__, error);
1196 		goto out;
1197 	}
1198 
1199 	if (server->nfs_client->cl_hostname == NULL)
1200 		server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
1201 	nfs_server_insert_lists(server);
1202 
1203 	error = nfs_probe_destination(server);
1204 	if (error < 0)
1205 		goto out;
1206 
1207 	dprintk("<-- %s() succeeded\n", __func__);
1208 
1209 out:
1210 	return error;
1211 }
1212