xref: /openbmc/linux/fs/nfs/nfs4client.c (revision f6723b56)
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 <linux/sunrpc/rpc_pipe_fs.h>
14 #include "internal.h"
15 #include "callback.h"
16 #include "delegation.h"
17 #include "nfs4session.h"
18 #include "pnfs.h"
19 #include "netns.h"
20 
21 #define NFSDBG_FACILITY		NFSDBG_CLIENT
22 
23 /*
24  * Get a unique NFSv4.0 callback identifier which will be used
25  * by the V4.0 callback service to lookup the nfs_client struct
26  */
27 static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
28 {
29 	int ret = 0;
30 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
31 
32 	if (clp->rpc_ops->version != 4 || minorversion != 0)
33 		return ret;
34 	idr_preload(GFP_KERNEL);
35 	spin_lock(&nn->nfs_client_lock);
36 	ret = idr_alloc(&nn->cb_ident_idr, clp, 0, 0, GFP_NOWAIT);
37 	if (ret >= 0)
38 		clp->cl_cb_ident = ret;
39 	spin_unlock(&nn->nfs_client_lock);
40 	idr_preload_end();
41 	return ret < 0 ? ret : 0;
42 }
43 
44 #ifdef CONFIG_NFS_V4_1
45 /**
46  * Per auth flavor data server rpc clients
47  */
48 struct nfs4_ds_server {
49 	struct list_head	list;   /* ds_clp->cl_ds_clients */
50 	struct rpc_clnt		*rpc_clnt;
51 };
52 
53 /**
54  * Common lookup case for DS I/O
55  */
56 static struct nfs4_ds_server *
57 nfs4_find_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
58 {
59 	struct nfs4_ds_server *dss;
60 
61 	rcu_read_lock();
62 	list_for_each_entry_rcu(dss, &ds_clp->cl_ds_clients, list) {
63 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
64 			continue;
65 		goto out;
66 	}
67 	dss = NULL;
68 out:
69 	rcu_read_unlock();
70 	return dss;
71 }
72 
73 static struct nfs4_ds_server *
74 nfs4_add_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor,
75 			   struct nfs4_ds_server *new)
76 {
77 	struct nfs4_ds_server *dss;
78 
79 	spin_lock(&ds_clp->cl_lock);
80 	list_for_each_entry(dss, &ds_clp->cl_ds_clients, list) {
81 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
82 			continue;
83 		goto out;
84 	}
85 	if (new)
86 		list_add_rcu(&new->list, &ds_clp->cl_ds_clients);
87 	dss = new;
88 out:
89 	spin_unlock(&ds_clp->cl_lock); /* need some lock to protect list */
90 	return dss;
91 }
92 
93 static struct nfs4_ds_server *
94 nfs4_alloc_ds_server(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
95 {
96 	struct nfs4_ds_server *dss;
97 
98 	dss = kmalloc(sizeof(*dss), GFP_NOFS);
99 	if (dss == NULL)
100 		return ERR_PTR(-ENOMEM);
101 
102 	dss->rpc_clnt = rpc_clone_client_set_auth(ds_clp->cl_rpcclient, flavor);
103 	if (IS_ERR(dss->rpc_clnt)) {
104 		int err = PTR_ERR(dss->rpc_clnt);
105 		kfree (dss);
106 		return ERR_PTR(err);
107 	}
108 	INIT_LIST_HEAD(&dss->list);
109 
110 	return dss;
111 }
112 
113 static void
114 nfs4_free_ds_server(struct nfs4_ds_server *dss)
115 {
116 	rpc_release_client(dss->rpc_clnt);
117 	kfree(dss);
118 }
119 
120 /**
121 * Find or create a DS rpc client with th MDS server rpc client auth flavor
122 * in the nfs_client cl_ds_clients list.
123 */
124 struct rpc_clnt *
125 nfs4_find_or_create_ds_client(struct nfs_client *ds_clp, struct inode *inode)
126 {
127 	struct nfs4_ds_server *dss, *new;
128 	rpc_authflavor_t flavor = NFS_SERVER(inode)->client->cl_auth->au_flavor;
129 
130 	dss = nfs4_find_ds_client(ds_clp, flavor);
131 	if (dss != NULL)
132 		goto out;
133 	new = nfs4_alloc_ds_server(ds_clp, flavor);
134 	if (IS_ERR(new))
135 		return ERR_CAST(new);
136 	dss = nfs4_add_ds_client(ds_clp, flavor, new);
137 	if (dss != new)
138 		nfs4_free_ds_server(new);
139 out:
140 	return dss->rpc_clnt;
141 }
142 EXPORT_SYMBOL_GPL(nfs4_find_or_create_ds_client);
143 
144 static void
145 nfs4_shutdown_ds_clients(struct nfs_client *clp)
146 {
147 	struct nfs4_ds_server *dss;
148 	LIST_HEAD(shutdown_list);
149 
150 	while (!list_empty(&clp->cl_ds_clients)) {
151 		dss = list_entry(clp->cl_ds_clients.next,
152 					struct nfs4_ds_server, list);
153 		list_del(&dss->list);
154 		rpc_shutdown_client(dss->rpc_clnt);
155 		kfree (dss);
156 	}
157 }
158 
159 void nfs41_shutdown_client(struct nfs_client *clp)
160 {
161 	if (nfs4_has_session(clp)) {
162 		nfs4_shutdown_ds_clients(clp);
163 		nfs4_destroy_session(clp->cl_session);
164 		nfs4_destroy_clientid(clp);
165 	}
166 
167 }
168 #endif	/* CONFIG_NFS_V4_1 */
169 
170 void nfs40_shutdown_client(struct nfs_client *clp)
171 {
172 	if (clp->cl_slot_tbl) {
173 		nfs4_shutdown_slot_table(clp->cl_slot_tbl);
174 		kfree(clp->cl_slot_tbl);
175 	}
176 }
177 
178 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
179 {
180 	int err;
181 	struct nfs_client *clp = nfs_alloc_client(cl_init);
182 	if (IS_ERR(clp))
183 		return clp;
184 
185 	err = nfs_get_cb_ident_idr(clp, cl_init->minorversion);
186 	if (err)
187 		goto error;
188 
189 	if (cl_init->minorversion > NFS4_MAX_MINOR_VERSION) {
190 		err = -EINVAL;
191 		goto error;
192 	}
193 
194 	spin_lock_init(&clp->cl_lock);
195 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
196 	INIT_LIST_HEAD(&clp->cl_ds_clients);
197 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
198 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
199 	clp->cl_minorversion = cl_init->minorversion;
200 	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
201 	clp->cl_mig_gen = 1;
202 	return clp;
203 
204 error:
205 	nfs_free_client(clp);
206 	return ERR_PTR(err);
207 }
208 
209 /*
210  * Destroy the NFS4 callback service
211  */
212 static void nfs4_destroy_callback(struct nfs_client *clp)
213 {
214 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
215 		nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
216 }
217 
218 static void nfs4_shutdown_client(struct nfs_client *clp)
219 {
220 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
221 		nfs4_kill_renewd(clp);
222 	clp->cl_mvops->shutdown_client(clp);
223 	nfs4_destroy_callback(clp);
224 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
225 		nfs_idmap_delete(clp);
226 
227 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
228 	kfree(clp->cl_serverowner);
229 	kfree(clp->cl_serverscope);
230 	kfree(clp->cl_implid);
231 }
232 
233 void nfs4_free_client(struct nfs_client *clp)
234 {
235 	nfs4_shutdown_client(clp);
236 	nfs_free_client(clp);
237 }
238 
239 /*
240  * Initialize the NFS4 callback service
241  */
242 static int nfs4_init_callback(struct nfs_client *clp)
243 {
244 	int error;
245 
246 	if (clp->rpc_ops->version == 4) {
247 		struct rpc_xprt *xprt;
248 
249 		xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
250 
251 		if (nfs4_has_session(clp)) {
252 			error = xprt_setup_backchannel(xprt,
253 						NFS41_BC_MIN_CALLBACKS);
254 			if (error < 0)
255 				return error;
256 		}
257 
258 		error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
259 		if (error < 0) {
260 			dprintk("%s: failed to start callback. Error = %d\n",
261 				__func__, error);
262 			return error;
263 		}
264 		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
265 	}
266 	return 0;
267 }
268 
269 /**
270  * nfs40_init_client - nfs_client initialization tasks for NFSv4.0
271  * @clp - nfs_client to initialize
272  *
273  * Returns zero on success, or a negative errno if some error occurred.
274  */
275 int nfs40_init_client(struct nfs_client *clp)
276 {
277 	struct nfs4_slot_table *tbl;
278 	int ret;
279 
280 	tbl = kzalloc(sizeof(*tbl), GFP_NOFS);
281 	if (tbl == NULL)
282 		return -ENOMEM;
283 
284 	ret = nfs4_setup_slot_table(tbl, NFS4_MAX_SLOT_TABLE,
285 					"NFSv4.0 transport Slot table");
286 	if (ret) {
287 		kfree(tbl);
288 		return ret;
289 	}
290 
291 	clp->cl_slot_tbl = tbl;
292 	return 0;
293 }
294 
295 #if defined(CONFIG_NFS_V4_1)
296 
297 /**
298  * nfs41_init_client - nfs_client initialization tasks for NFSv4.1+
299  * @clp - nfs_client to initialize
300  *
301  * Returns zero on success, or a negative errno if some error occurred.
302  */
303 int nfs41_init_client(struct nfs_client *clp)
304 {
305 	struct nfs4_session *session = NULL;
306 
307 	/*
308 	 * Create the session and mark it expired.
309 	 * When a SEQUENCE operation encounters the expired session
310 	 * it will do session recovery to initialize it.
311 	 */
312 	session = nfs4_alloc_session(clp);
313 	if (!session)
314 		return -ENOMEM;
315 
316 	clp->cl_session = session;
317 
318 	/*
319 	 * The create session reply races with the server back
320 	 * channel probe. Mark the client NFS_CS_SESSION_INITING
321 	 * so that the client back channel can find the
322 	 * nfs_client struct
323 	 */
324 	nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
325 	return 0;
326 }
327 
328 #endif	/* CONFIG_NFS_V4_1 */
329 
330 /*
331  * Initialize the minor version specific parts of an NFS4 client record
332  */
333 static int nfs4_init_client_minor_version(struct nfs_client *clp)
334 {
335 	int ret;
336 
337 	ret = clp->cl_mvops->init_client(clp);
338 	if (ret)
339 		return ret;
340 	return nfs4_init_callback(clp);
341 }
342 
343 /**
344  * nfs4_init_client - Initialise an NFS4 client record
345  *
346  * @clp: nfs_client to initialise
347  * @timeparms: timeout parameters for underlying RPC transport
348  * @ip_addr: callback IP address in presentation format
349  * @authflavor: authentication flavor for underlying RPC transport
350  *
351  * Returns pointer to an NFS client, or an ERR_PTR value.
352  */
353 struct nfs_client *nfs4_init_client(struct nfs_client *clp,
354 				    const struct rpc_timeout *timeparms,
355 				    const char *ip_addr)
356 {
357 	char buf[INET6_ADDRSTRLEN + 1];
358 	struct nfs_client *old;
359 	int error;
360 
361 	if (clp->cl_cons_state == NFS_CS_READY) {
362 		/* the client is initialised already */
363 		dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
364 		return clp;
365 	}
366 
367 	/* Check NFS protocol revision and initialize RPC op vector */
368 	clp->rpc_ops = &nfs_v4_clientops;
369 
370 	if (clp->cl_minorversion != 0)
371 		__set_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags);
372 	__set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
373 	__set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags);
374 
375 	error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_GSS_KRB5I);
376 	if (error == -EINVAL)
377 		error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_UNIX);
378 	if (error < 0)
379 		goto error;
380 
381 	/* If no clientaddr= option was specified, find a usable cb address */
382 	if (ip_addr == NULL) {
383 		struct sockaddr_storage cb_addr;
384 		struct sockaddr *sap = (struct sockaddr *)&cb_addr;
385 
386 		error = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
387 		if (error < 0)
388 			goto error;
389 		error = rpc_ntop(sap, buf, sizeof(buf));
390 		if (error < 0)
391 			goto error;
392 		ip_addr = (const char *)buf;
393 	}
394 	strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
395 
396 	error = nfs_idmap_new(clp);
397 	if (error < 0) {
398 		dprintk("%s: failed to create idmapper. Error = %d\n",
399 			__func__, error);
400 		goto error;
401 	}
402 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
403 
404 	error = nfs4_init_client_minor_version(clp);
405 	if (error < 0)
406 		goto error;
407 
408 	if (!nfs4_has_session(clp))
409 		nfs_mark_client_ready(clp, NFS_CS_READY);
410 
411 	error = nfs4_discover_server_trunking(clp, &old);
412 	if (error < 0)
413 		goto error;
414 
415 	if (clp != old)
416 		clp->cl_preserve_clid = true;
417 	nfs_put_client(clp);
418 	return old;
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 			if (status < 0)
497 				goto out;
498 			status = -NFS4ERR_STALE_CLIENTID;
499 			spin_lock(&nn->nfs_client_lock);
500 		}
501 		if (pos->cl_cons_state != NFS_CS_READY)
502 			continue;
503 
504 		if (pos->rpc_ops != new->rpc_ops)
505 			continue;
506 
507 		if (pos->cl_proto != new->cl_proto)
508 			continue;
509 
510 		if (pos->cl_minorversion != new->cl_minorversion)
511 			continue;
512 
513 		if (pos->cl_clientid != new->cl_clientid)
514 			continue;
515 
516 		atomic_inc(&pos->cl_count);
517 		spin_unlock(&nn->nfs_client_lock);
518 
519 		if (prev)
520 			nfs_put_client(prev);
521 		prev = pos;
522 
523 		status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
524 		switch (status) {
525 		case -NFS4ERR_STALE_CLIENTID:
526 			break;
527 		case 0:
528 			nfs4_swap_callback_idents(pos, new);
529 
530 			prev = NULL;
531 			*result = pos;
532 			dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
533 				__func__, pos, atomic_read(&pos->cl_count));
534 		default:
535 			goto out;
536 		}
537 
538 		spin_lock(&nn->nfs_client_lock);
539 	}
540 	spin_unlock(&nn->nfs_client_lock);
541 
542 	/* No match found. The server lost our clientid */
543 out:
544 	if (prev)
545 		nfs_put_client(prev);
546 	dprintk("NFS: <-- %s status = %d\n", __func__, status);
547 	return status;
548 }
549 
550 #ifdef CONFIG_NFS_V4_1
551 /*
552  * Returns true if the client IDs match
553  */
554 static bool nfs4_match_clientids(struct nfs_client *a, struct nfs_client *b)
555 {
556 	if (a->cl_clientid != b->cl_clientid) {
557 		dprintk("NFS: --> %s client ID %llx does not match %llx\n",
558 			__func__, a->cl_clientid, b->cl_clientid);
559 		return false;
560 	}
561 	dprintk("NFS: --> %s client ID %llx matches %llx\n",
562 		__func__, a->cl_clientid, b->cl_clientid);
563 	return true;
564 }
565 
566 /*
567  * Returns true if the server owners match
568  */
569 static bool
570 nfs4_match_serverowners(struct nfs_client *a, struct nfs_client *b)
571 {
572 	struct nfs41_server_owner *o1 = a->cl_serverowner;
573 	struct nfs41_server_owner *o2 = b->cl_serverowner;
574 
575 	if (o1->minor_id != o2->minor_id) {
576 		dprintk("NFS: --> %s server owner minor IDs do not match\n",
577 			__func__);
578 		return false;
579 	}
580 
581 	if (o1->major_id_sz != o2->major_id_sz)
582 		goto out_major_mismatch;
583 	if (memcmp(o1->major_id, o2->major_id, o1->major_id_sz) != 0)
584 		goto out_major_mismatch;
585 
586 	dprintk("NFS: --> %s server owners match\n", __func__);
587 	return true;
588 
589 out_major_mismatch:
590 	dprintk("NFS: --> %s server owner major IDs do not match\n",
591 		__func__);
592 	return false;
593 }
594 
595 /**
596  * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
597  *
598  * @new: nfs_client with client ID to test
599  * @result: OUT: found nfs_client, or new
600  * @cred: credential to use for trunking test
601  *
602  * Returns zero, a negative errno, or a negative NFS4ERR status.
603  * If zero is returned, an nfs_client pointer is planted in "result."
604  *
605  * NB: nfs41_walk_client_list() relies on the new nfs_client being
606  *     the last nfs_client on the list.
607  */
608 int nfs41_walk_client_list(struct nfs_client *new,
609 			   struct nfs_client **result,
610 			   struct rpc_cred *cred)
611 {
612 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
613 	struct nfs_client *pos, *prev = NULL;
614 	int status = -NFS4ERR_STALE_CLIENTID;
615 
616 	spin_lock(&nn->nfs_client_lock);
617 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
618 		/* If "pos" isn't marked ready, we can't trust the
619 		 * remaining fields in "pos", especially the client
620 		 * ID and serverowner fields.  Wait for CREATE_SESSION
621 		 * to finish. */
622 		if (pos->cl_cons_state > NFS_CS_READY) {
623 			atomic_inc(&pos->cl_count);
624 			spin_unlock(&nn->nfs_client_lock);
625 
626 			if (prev)
627 				nfs_put_client(prev);
628 			prev = pos;
629 
630 			status = nfs_wait_client_init_complete(pos);
631 			if (status == 0) {
632 				nfs4_schedule_lease_recovery(pos);
633 				status = nfs4_wait_clnt_recover(pos);
634 			}
635 			spin_lock(&nn->nfs_client_lock);
636 			if (status < 0)
637 				break;
638 			status = -NFS4ERR_STALE_CLIENTID;
639 		}
640 		if (pos->cl_cons_state != NFS_CS_READY)
641 			continue;
642 
643 		if (pos->rpc_ops != new->rpc_ops)
644 			continue;
645 
646 		if (pos->cl_proto != new->cl_proto)
647 			continue;
648 
649 		if (pos->cl_minorversion != new->cl_minorversion)
650 			continue;
651 
652 		if (!nfs4_match_clientids(pos, new))
653 			continue;
654 
655 		if (!nfs4_match_serverowners(pos, new))
656 			continue;
657 
658 		atomic_inc(&pos->cl_count);
659 		*result = pos;
660 		status = 0;
661 		dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
662 			__func__, pos, atomic_read(&pos->cl_count));
663 		break;
664 	}
665 
666 	/* No matching nfs_client found. */
667 	spin_unlock(&nn->nfs_client_lock);
668 	dprintk("NFS: <-- %s status = %d\n", __func__, status);
669 	if (prev)
670 		nfs_put_client(prev);
671 	return status;
672 }
673 #endif	/* CONFIG_NFS_V4_1 */
674 
675 static void nfs4_destroy_server(struct nfs_server *server)
676 {
677 	nfs_server_return_all_delegations(server);
678 	unset_pnfs_layoutdriver(server);
679 	nfs4_purge_state_owners(server);
680 }
681 
682 /*
683  * NFSv4.0 callback thread helper
684  *
685  * Find a client by callback identifier
686  */
687 struct nfs_client *
688 nfs4_find_client_ident(struct net *net, int cb_ident)
689 {
690 	struct nfs_client *clp;
691 	struct nfs_net *nn = net_generic(net, nfs_net_id);
692 
693 	spin_lock(&nn->nfs_client_lock);
694 	clp = idr_find(&nn->cb_ident_idr, cb_ident);
695 	if (clp)
696 		atomic_inc(&clp->cl_count);
697 	spin_unlock(&nn->nfs_client_lock);
698 	return clp;
699 }
700 
701 #if defined(CONFIG_NFS_V4_1)
702 /* Common match routine for v4.0 and v4.1 callback services */
703 static bool nfs4_cb_match_client(const struct sockaddr *addr,
704 		struct nfs_client *clp, u32 minorversion)
705 {
706 	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
707 
708 	/* Don't match clients that failed to initialise */
709 	if (!(clp->cl_cons_state == NFS_CS_READY ||
710 	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
711 		return false;
712 
713 	smp_rmb();
714 
715 	/* Match the version and minorversion */
716 	if (clp->rpc_ops->version != 4 ||
717 	    clp->cl_minorversion != minorversion)
718 		return false;
719 
720 	/* Match only the IP address, not the port number */
721 	if (!nfs_sockaddr_match_ipaddr(addr, clap))
722 		return false;
723 
724 	return true;
725 }
726 
727 /*
728  * NFSv4.1 callback thread helper
729  * For CB_COMPOUND calls, find a client by IP address, protocol version,
730  * minorversion, and sessionID
731  *
732  * Returns NULL if no such client
733  */
734 struct nfs_client *
735 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
736 			   struct nfs4_sessionid *sid, u32 minorversion)
737 {
738 	struct nfs_client *clp;
739 	struct nfs_net *nn = net_generic(net, nfs_net_id);
740 
741 	spin_lock(&nn->nfs_client_lock);
742 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
743 		if (nfs4_cb_match_client(addr, clp, minorversion) == false)
744 			continue;
745 
746 		if (!nfs4_has_session(clp))
747 			continue;
748 
749 		/* Match sessionid*/
750 		if (memcmp(clp->cl_session->sess_id.data,
751 		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
752 			continue;
753 
754 		atomic_inc(&clp->cl_count);
755 		spin_unlock(&nn->nfs_client_lock);
756 		return clp;
757 	}
758 	spin_unlock(&nn->nfs_client_lock);
759 	return NULL;
760 }
761 
762 #else /* CONFIG_NFS_V4_1 */
763 
764 struct nfs_client *
765 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
766 			   struct nfs4_sessionid *sid, u32 minorversion)
767 {
768 	return NULL;
769 }
770 #endif /* CONFIG_NFS_V4_1 */
771 
772 /*
773  * Set up an NFS4 client
774  */
775 static int nfs4_set_client(struct nfs_server *server,
776 		const char *hostname,
777 		const struct sockaddr *addr,
778 		const size_t addrlen,
779 		const char *ip_addr,
780 		rpc_authflavor_t authflavour,
781 		int proto, const struct rpc_timeout *timeparms,
782 		u32 minorversion, struct net *net)
783 {
784 	struct nfs_client_initdata cl_init = {
785 		.hostname = hostname,
786 		.addr = addr,
787 		.addrlen = addrlen,
788 		.nfs_mod = &nfs_v4,
789 		.proto = proto,
790 		.minorversion = minorversion,
791 		.net = net,
792 	};
793 	struct nfs_client *clp;
794 	int error;
795 
796 	dprintk("--> nfs4_set_client()\n");
797 
798 	if (server->flags & NFS_MOUNT_NORESVPORT)
799 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
800 	if (server->options & NFS_OPTION_MIGRATION)
801 		set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
802 
803 	/* Allocate or find a client reference we can use */
804 	clp = nfs_get_client(&cl_init, timeparms, ip_addr, authflavour);
805 	if (IS_ERR(clp)) {
806 		error = PTR_ERR(clp);
807 		goto error;
808 	}
809 
810 	/*
811 	 * Query for the lease time on clientid setup or renewal
812 	 *
813 	 * Note that this will be set on nfs_clients that were created
814 	 * only for the DS role and did not set this bit, but now will
815 	 * serve a dual role.
816 	 */
817 	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
818 
819 	server->nfs_client = clp;
820 	dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
821 	return 0;
822 error:
823 	dprintk("<-- nfs4_set_client() = xerror %d\n", error);
824 	return error;
825 }
826 
827 /*
828  * Set up a pNFS Data Server client.
829  *
830  * Return any existing nfs_client that matches server address,port,version
831  * and minorversion.
832  *
833  * For a new nfs_client, use a soft mount (default), a low retrans and a
834  * low timeout interval so that if a connection is lost, we retry through
835  * the MDS.
836  */
837 struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
838 		const struct sockaddr *ds_addr, int ds_addrlen,
839 		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans)
840 {
841 	struct nfs_client_initdata cl_init = {
842 		.addr = ds_addr,
843 		.addrlen = ds_addrlen,
844 		.nfs_mod = &nfs_v4,
845 		.proto = ds_proto,
846 		.minorversion = mds_clp->cl_minorversion,
847 		.net = mds_clp->cl_net,
848 	};
849 	struct rpc_timeout ds_timeout;
850 	struct nfs_client *clp;
851 
852 	/*
853 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
854 	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
855 	 * (section 13.1 RFC 5661).
856 	 */
857 	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
858 	clp = nfs_get_client(&cl_init, &ds_timeout, mds_clp->cl_ipaddr,
859 			     mds_clp->cl_rpcclient->cl_auth->au_flavor);
860 
861 	dprintk("<-- %s %p\n", __func__, clp);
862 	return clp;
863 }
864 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
865 
866 /*
867  * Session has been established, and the client marked ready.
868  * Set the mount rsize and wsize with negotiated fore channel
869  * attributes which will be bound checked in nfs_server_set_fsinfo.
870  */
871 static void nfs4_session_set_rwsize(struct nfs_server *server)
872 {
873 #ifdef CONFIG_NFS_V4_1
874 	struct nfs4_session *sess;
875 	u32 server_resp_sz;
876 	u32 server_rqst_sz;
877 
878 	if (!nfs4_has_session(server->nfs_client))
879 		return;
880 	sess = server->nfs_client->cl_session;
881 	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
882 	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
883 
884 	if (server->rsize > server_resp_sz)
885 		server->rsize = server_resp_sz;
886 	if (server->wsize > server_rqst_sz)
887 		server->wsize = server_rqst_sz;
888 #endif /* CONFIG_NFS_V4_1 */
889 }
890 
891 static int nfs4_server_common_setup(struct nfs_server *server,
892 		struct nfs_fh *mntfh, bool auth_probe)
893 {
894 	struct nfs_fattr *fattr;
895 	int error;
896 
897 	/* data servers support only a subset of NFSv4.1 */
898 	if (is_ds_only_client(server->nfs_client))
899 		return -EPROTONOSUPPORT;
900 
901 	fattr = nfs_alloc_fattr();
902 	if (fattr == NULL)
903 		return -ENOMEM;
904 
905 	/* We must ensure the session is initialised first */
906 	error = nfs4_init_session(server->nfs_client);
907 	if (error < 0)
908 		goto out;
909 
910 	/* Set the basic capabilities */
911 	server->caps |= server->nfs_client->cl_mvops->init_caps;
912 	if (server->flags & NFS_MOUNT_NORDIRPLUS)
913 			server->caps &= ~NFS_CAP_READDIRPLUS;
914 	/*
915 	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
916 	 * authentication.
917 	 */
918 	if (nfs4_disable_idmapping &&
919 			server->client->cl_auth->au_flavor == RPC_AUTH_UNIX)
920 		server->caps |= NFS_CAP_UIDGID_NOMAP;
921 
922 
923 	/* Probe the root fh to retrieve its FSID and filehandle */
924 	error = nfs4_get_rootfh(server, mntfh, auth_probe);
925 	if (error < 0)
926 		goto out;
927 
928 	dprintk("Server FSID: %llx:%llx\n",
929 			(unsigned long long) server->fsid.major,
930 			(unsigned long long) server->fsid.minor);
931 	nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
932 
933 	nfs4_session_set_rwsize(server);
934 
935 	error = nfs_probe_fsinfo(server, mntfh, fattr);
936 	if (error < 0)
937 		goto out;
938 
939 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
940 		server->namelen = NFS4_MAXNAMLEN;
941 
942 	nfs_server_insert_lists(server);
943 	server->mount_time = jiffies;
944 	server->destroy = nfs4_destroy_server;
945 out:
946 	nfs_free_fattr(fattr);
947 	return error;
948 }
949 
950 /*
951  * Create a version 4 volume record
952  */
953 static int nfs4_init_server(struct nfs_server *server,
954 		struct nfs_parsed_mount_data *data)
955 {
956 	struct rpc_timeout timeparms;
957 	int error;
958 
959 	dprintk("--> nfs4_init_server()\n");
960 
961 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
962 			data->timeo, data->retrans);
963 
964 	/* Initialise the client representation from the mount data */
965 	server->flags = data->flags;
966 	server->options = data->options;
967 	server->auth_info = data->auth_info;
968 
969 	/* Use the first specified auth flavor. If this flavor isn't
970 	 * allowed by the server, use the SECINFO path to try the
971 	 * other specified flavors */
972 	if (data->auth_info.flavor_len >= 1)
973 		data->selected_flavor = data->auth_info.flavors[0];
974 	else
975 		data->selected_flavor = RPC_AUTH_UNIX;
976 
977 	/* Get a client record */
978 	error = nfs4_set_client(server,
979 			data->nfs_server.hostname,
980 			(const struct sockaddr *)&data->nfs_server.address,
981 			data->nfs_server.addrlen,
982 			data->client_address,
983 			data->selected_flavor,
984 			data->nfs_server.protocol,
985 			&timeparms,
986 			data->minorversion,
987 			data->net);
988 	if (error < 0)
989 		goto error;
990 
991 	if (data->rsize)
992 		server->rsize = nfs_block_size(data->rsize, NULL);
993 	if (data->wsize)
994 		server->wsize = nfs_block_size(data->wsize, NULL);
995 
996 	server->acregmin = data->acregmin * HZ;
997 	server->acregmax = data->acregmax * HZ;
998 	server->acdirmin = data->acdirmin * HZ;
999 	server->acdirmax = data->acdirmax * HZ;
1000 
1001 	server->port = data->nfs_server.port;
1002 
1003 	error = nfs_init_server_rpcclient(server, &timeparms,
1004 					  data->selected_flavor);
1005 
1006 error:
1007 	/* Done */
1008 	dprintk("<-- nfs4_init_server() = %d\n", error);
1009 	return error;
1010 }
1011 
1012 /*
1013  * Create a version 4 volume record
1014  * - keyed on server and FSID
1015  */
1016 /*struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
1017 				      struct nfs_fh *mntfh)*/
1018 struct nfs_server *nfs4_create_server(struct nfs_mount_info *mount_info,
1019 				      struct nfs_subversion *nfs_mod)
1020 {
1021 	struct nfs_server *server;
1022 	bool auth_probe;
1023 	int error;
1024 
1025 	dprintk("--> nfs4_create_server()\n");
1026 
1027 	server = nfs_alloc_server();
1028 	if (!server)
1029 		return ERR_PTR(-ENOMEM);
1030 
1031 	auth_probe = mount_info->parsed->auth_info.flavor_len < 1;
1032 
1033 	/* set up the general RPC client */
1034 	error = nfs4_init_server(server, mount_info->parsed);
1035 	if (error < 0)
1036 		goto error;
1037 
1038 	error = nfs4_server_common_setup(server, mount_info->mntfh, auth_probe);
1039 	if (error < 0)
1040 		goto error;
1041 
1042 	dprintk("<-- nfs4_create_server() = %p\n", server);
1043 	return server;
1044 
1045 error:
1046 	nfs_free_server(server);
1047 	dprintk("<-- nfs4_create_server() = error %d\n", error);
1048 	return ERR_PTR(error);
1049 }
1050 
1051 /*
1052  * Create an NFS4 referral server record
1053  */
1054 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
1055 					       struct nfs_fh *mntfh)
1056 {
1057 	struct nfs_client *parent_client;
1058 	struct nfs_server *server, *parent_server;
1059 	bool auth_probe;
1060 	int error;
1061 
1062 	dprintk("--> nfs4_create_referral_server()\n");
1063 
1064 	server = nfs_alloc_server();
1065 	if (!server)
1066 		return ERR_PTR(-ENOMEM);
1067 
1068 	parent_server = NFS_SB(data->sb);
1069 	parent_client = parent_server->nfs_client;
1070 
1071 	/* Initialise the client representation from the parent server */
1072 	nfs_server_copy_userdata(server, parent_server);
1073 
1074 	/* Get a client representation.
1075 	 * Note: NFSv4 always uses TCP, */
1076 	error = nfs4_set_client(server, data->hostname,
1077 				data->addr,
1078 				data->addrlen,
1079 				parent_client->cl_ipaddr,
1080 				data->authflavor,
1081 				rpc_protocol(parent_server->client),
1082 				parent_server->client->cl_timeout,
1083 				parent_client->cl_mvops->minor_version,
1084 				parent_client->cl_net);
1085 	if (error < 0)
1086 		goto error;
1087 
1088 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor);
1089 	if (error < 0)
1090 		goto error;
1091 
1092 	auth_probe = parent_server->auth_info.flavor_len < 1;
1093 
1094 	error = nfs4_server_common_setup(server, mntfh, auth_probe);
1095 	if (error < 0)
1096 		goto error;
1097 
1098 	dprintk("<-- nfs_create_referral_server() = %p\n", server);
1099 	return server;
1100 
1101 error:
1102 	nfs_free_server(server);
1103 	dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
1104 	return ERR_PTR(error);
1105 }
1106 
1107 /*
1108  * Grab the destination's particulars, including lease expiry time.
1109  *
1110  * Returns zero if probe succeeded and retrieved FSID matches the FSID
1111  * we have cached.
1112  */
1113 static int nfs_probe_destination(struct nfs_server *server)
1114 {
1115 	struct inode *inode = server->super->s_root->d_inode;
1116 	struct nfs_fattr *fattr;
1117 	int error;
1118 
1119 	fattr = nfs_alloc_fattr();
1120 	if (fattr == NULL)
1121 		return -ENOMEM;
1122 
1123 	/* Sanity: the probe won't work if the destination server
1124 	 * does not recognize the migrated FH. */
1125 	error = nfs_probe_fsinfo(server, NFS_FH(inode), fattr);
1126 
1127 	nfs_free_fattr(fattr);
1128 	return error;
1129 }
1130 
1131 /**
1132  * nfs4_update_server - Move an nfs_server to a different nfs_client
1133  *
1134  * @server: represents FSID to be moved
1135  * @hostname: new end-point's hostname
1136  * @sap: new end-point's socket address
1137  * @salen: size of "sap"
1138  *
1139  * The nfs_server must be quiescent before this function is invoked.
1140  * Either its session is drained (NFSv4.1+), or its transport is
1141  * plugged and drained (NFSv4.0).
1142  *
1143  * Returns zero on success, or a negative errno value.
1144  */
1145 int nfs4_update_server(struct nfs_server *server, const char *hostname,
1146 		       struct sockaddr *sap, size_t salen)
1147 {
1148 	struct nfs_client *clp = server->nfs_client;
1149 	struct rpc_clnt *clnt = server->client;
1150 	struct xprt_create xargs = {
1151 		.ident		= clp->cl_proto,
1152 		.net		= &init_net,
1153 		.dstaddr	= sap,
1154 		.addrlen	= salen,
1155 		.servername	= hostname,
1156 	};
1157 	char buf[INET6_ADDRSTRLEN + 1];
1158 	struct sockaddr_storage address;
1159 	struct sockaddr *localaddr = (struct sockaddr *)&address;
1160 	int error;
1161 
1162 	dprintk("--> %s: move FSID %llx:%llx to \"%s\")\n", __func__,
1163 			(unsigned long long)server->fsid.major,
1164 			(unsigned long long)server->fsid.minor,
1165 			hostname);
1166 
1167 	error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
1168 	if (error != 0) {
1169 		dprintk("<-- %s(): rpc_switch_client_transport returned %d\n",
1170 			__func__, error);
1171 		goto out;
1172 	}
1173 
1174 	error = rpc_localaddr(clnt, localaddr, sizeof(address));
1175 	if (error != 0) {
1176 		dprintk("<-- %s(): rpc_localaddr returned %d\n",
1177 			__func__, error);
1178 		goto out;
1179 	}
1180 
1181 	error = -EAFNOSUPPORT;
1182 	if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0) {
1183 		dprintk("<-- %s(): rpc_ntop returned %d\n",
1184 			__func__, error);
1185 		goto out;
1186 	}
1187 
1188 	nfs_server_remove_lists(server);
1189 	error = nfs4_set_client(server, hostname, sap, salen, buf,
1190 				clp->cl_rpcclient->cl_auth->au_flavor,
1191 				clp->cl_proto, clnt->cl_timeout,
1192 				clp->cl_minorversion, clp->cl_net);
1193 	nfs_put_client(clp);
1194 	if (error != 0) {
1195 		nfs_server_insert_lists(server);
1196 		dprintk("<-- %s(): nfs4_set_client returned %d\n",
1197 			__func__, error);
1198 		goto out;
1199 	}
1200 
1201 	if (server->nfs_client->cl_hostname == NULL)
1202 		server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
1203 	nfs_server_insert_lists(server);
1204 
1205 	error = nfs_probe_destination(server);
1206 	if (error < 0)
1207 		goto out;
1208 
1209 	dprintk("<-- %s() succeeded\n", __func__);
1210 
1211 out:
1212 	return error;
1213 }
1214