• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  *  fs/nfs/nfs4state.c
3  *
4  *  Client-side XDR for NFSv4.
5  *
6  *  Copyright (c) 2002 The Regents of the University of Michigan.
7  *  All rights reserved.
8  *
9  *  Kendrick Smith <kmsmith@umich.edu>
10  *
11  *  Redistribution and use in source and binary forms, with or without
12  *  modification, are permitted provided that the following conditions
13  *  are met:
14  *
15  *  1. Redistributions of source code must retain the above copyright
16  *     notice, this list of conditions and the following disclaimer.
17  *  2. Redistributions in binary form must reproduce the above copyright
18  *     notice, this list of conditions and the following disclaimer in the
19  *     documentation and/or other materials provided with the distribution.
20  *  3. Neither the name of the University nor the names of its
21  *     contributors may be used to endorse or promote products derived
22  *     from this software without specific prior written permission.
23  *
24  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
25  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
26  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
27  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
31  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  *
36  * Implementation of the NFSv4 state model.  For the time being,
37  * this is minimal, but will be made much more complex in a
38  * subsequent patch.
39  */
40 
41 #include <linux/kernel.h>
42 #include <linux/slab.h>
43 #include <linux/fs.h>
44 #include <linux/nfs_fs.h>
45 #include <linux/kthread.h>
46 #include <linux/module.h>
47 #include <linux/random.h>
48 #include <linux/ratelimit.h>
49 #include <linux/workqueue.h>
50 #include <linux/bitops.h>
51 #include <linux/jiffies.h>
52 #include <linux/sched/mm.h>
53 
54 #include <linux/sunrpc/clnt.h>
55 
56 #include "nfs4_fs.h"
57 #include "callback.h"
58 #include "delegation.h"
59 #include "internal.h"
60 #include "nfs4idmap.h"
61 #include "nfs4session.h"
62 #include "pnfs.h"
63 #include "netns.h"
64 #include "nfs4trace.h"
65 
66 #define NFSDBG_FACILITY		NFSDBG_STATE
67 
68 #define OPENOWNER_POOL_SIZE	8
69 
70 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp);
71 
72 const nfs4_stateid zero_stateid = {
73 	{ .data = { 0 } },
74 	.type = NFS4_SPECIAL_STATEID_TYPE,
75 };
76 const nfs4_stateid invalid_stateid = {
77 	{
78 		/* Funky initialiser keeps older gcc versions happy */
79 		.data = { 0xff, 0xff, 0xff, 0xff, 0 },
80 	},
81 	.type = NFS4_INVALID_STATEID_TYPE,
82 };
83 
84 const nfs4_stateid current_stateid = {
85 	{
86 		/* Funky initialiser keeps older gcc versions happy */
87 		.data = { 0x0, 0x0, 0x0, 0x1, 0 },
88 	},
89 	.type = NFS4_SPECIAL_STATEID_TYPE,
90 };
91 
92 static DEFINE_MUTEX(nfs_clid_init_mutex);
93 
nfs4_setup_state_renewal(struct nfs_client * clp)94 static int nfs4_setup_state_renewal(struct nfs_client *clp)
95 {
96 	int status;
97 	struct nfs_fsinfo fsinfo;
98 
99 	if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
100 		nfs4_schedule_state_renewal(clp);
101 		return 0;
102 	}
103 
104 	status = nfs4_proc_get_lease_time(clp, &fsinfo);
105 	if (status == 0) {
106 		nfs4_set_lease_period(clp, fsinfo.lease_time * HZ);
107 		nfs4_schedule_state_renewal(clp);
108 	}
109 
110 	return status;
111 }
112 
nfs4_init_clientid(struct nfs_client * clp,const struct cred * cred)113 int nfs4_init_clientid(struct nfs_client *clp, const struct cred *cred)
114 {
115 	struct nfs4_setclientid_res clid = {
116 		.clientid = clp->cl_clientid,
117 		.confirm = clp->cl_confirm,
118 	};
119 	unsigned short port;
120 	int status;
121 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
122 
123 	if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
124 		goto do_confirm;
125 	port = nn->nfs_callback_tcpport;
126 	if (clp->cl_addr.ss_family == AF_INET6)
127 		port = nn->nfs_callback_tcpport6;
128 
129 	status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
130 	if (status != 0)
131 		goto out;
132 	clp->cl_clientid = clid.clientid;
133 	clp->cl_confirm = clid.confirm;
134 	set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
135 do_confirm:
136 	status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
137 	if (status != 0)
138 		goto out;
139 	clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
140 	nfs4_setup_state_renewal(clp);
141 out:
142 	return status;
143 }
144 
145 /**
146  * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
147  *
148  * @clp: nfs_client under test
149  * @result: OUT: found nfs_client, or clp
150  * @cred: credential to use for trunking test
151  *
152  * Returns zero, a negative errno, or a negative NFS4ERR status.
153  * If zero is returned, an nfs_client pointer is planted in
154  * "result".
155  *
156  * Note: The returned client may not yet be marked ready.
157  */
nfs40_discover_server_trunking(struct nfs_client * clp,struct nfs_client ** result,const struct cred * cred)158 int nfs40_discover_server_trunking(struct nfs_client *clp,
159 				   struct nfs_client **result,
160 				   const struct cred *cred)
161 {
162 	struct nfs4_setclientid_res clid = {
163 		.clientid = clp->cl_clientid,
164 		.confirm = clp->cl_confirm,
165 	};
166 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
167 	unsigned short port;
168 	int status;
169 
170 	port = nn->nfs_callback_tcpport;
171 	if (clp->cl_addr.ss_family == AF_INET6)
172 		port = nn->nfs_callback_tcpport6;
173 
174 	status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
175 	if (status != 0)
176 		goto out;
177 	clp->cl_clientid = clid.clientid;
178 	clp->cl_confirm = clid.confirm;
179 
180 	status = nfs40_walk_client_list(clp, result, cred);
181 	if (status == 0) {
182 		/* Sustain the lease, even if it's empty.  If the clientid4
183 		 * goes stale it's of no use for trunking discovery. */
184 		nfs4_schedule_state_renewal(*result);
185 
186 		/* If the client state need to recover, do it. */
187 		if (clp->cl_state)
188 			nfs4_schedule_state_manager(clp);
189 	}
190 out:
191 	return status;
192 }
193 
nfs4_get_machine_cred(struct nfs_client * clp)194 const struct cred *nfs4_get_machine_cred(struct nfs_client *clp)
195 {
196 	return get_cred(rpc_machine_cred());
197 }
198 
nfs4_root_machine_cred(struct nfs_client * clp)199 static void nfs4_root_machine_cred(struct nfs_client *clp)
200 {
201 
202 	/* Force root creds instead of machine */
203 	clp->cl_principal = NULL;
204 	clp->cl_rpcclient->cl_principal = NULL;
205 }
206 
207 static const struct cred *
nfs4_get_renew_cred_server_locked(struct nfs_server * server)208 nfs4_get_renew_cred_server_locked(struct nfs_server *server)
209 {
210 	const struct cred *cred = NULL;
211 	struct nfs4_state_owner *sp;
212 	struct rb_node *pos;
213 
214 	for (pos = rb_first(&server->state_owners);
215 	     pos != NULL;
216 	     pos = rb_next(pos)) {
217 		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
218 		if (list_empty(&sp->so_states))
219 			continue;
220 		cred = get_cred(sp->so_cred);
221 		break;
222 	}
223 	return cred;
224 }
225 
226 /**
227  * nfs4_get_renew_cred - Acquire credential for a renew operation
228  * @clp: client state handle
229  *
230  * Returns an rpc_cred with reference count bumped, or NULL.
231  * Caller must hold clp->cl_lock.
232  */
nfs4_get_renew_cred(struct nfs_client * clp)233 const struct cred *nfs4_get_renew_cred(struct nfs_client *clp)
234 {
235 	const struct cred *cred = NULL;
236 	struct nfs_server *server;
237 
238 	/* Use machine credentials if available */
239 	cred = nfs4_get_machine_cred(clp);
240 	if (cred != NULL)
241 		goto out;
242 
243 	spin_lock(&clp->cl_lock);
244 	rcu_read_lock();
245 	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
246 		cred = nfs4_get_renew_cred_server_locked(server);
247 		if (cred != NULL)
248 			break;
249 	}
250 	rcu_read_unlock();
251 	spin_unlock(&clp->cl_lock);
252 
253 out:
254 	return cred;
255 }
256 
nfs4_end_drain_slot_table(struct nfs4_slot_table * tbl)257 static void nfs4_end_drain_slot_table(struct nfs4_slot_table *tbl)
258 {
259 	if (test_and_clear_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
260 		spin_lock(&tbl->slot_tbl_lock);
261 		nfs41_wake_slot_table(tbl);
262 		spin_unlock(&tbl->slot_tbl_lock);
263 	}
264 }
265 
nfs4_end_drain_session(struct nfs_client * clp)266 static void nfs4_end_drain_session(struct nfs_client *clp)
267 {
268 	struct nfs4_session *ses = clp->cl_session;
269 
270 	if (clp->cl_slot_tbl) {
271 		nfs4_end_drain_slot_table(clp->cl_slot_tbl);
272 		return;
273 	}
274 
275 	if (ses != NULL) {
276 		nfs4_end_drain_slot_table(&ses->bc_slot_table);
277 		nfs4_end_drain_slot_table(&ses->fc_slot_table);
278 	}
279 }
280 
nfs4_drain_slot_tbl(struct nfs4_slot_table * tbl)281 static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)
282 {
283 	set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
284 	spin_lock(&tbl->slot_tbl_lock);
285 	if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
286 		reinit_completion(&tbl->complete);
287 		spin_unlock(&tbl->slot_tbl_lock);
288 		return wait_for_completion_interruptible(&tbl->complete);
289 	}
290 	spin_unlock(&tbl->slot_tbl_lock);
291 	return 0;
292 }
293 
nfs4_begin_drain_session(struct nfs_client * clp)294 static int nfs4_begin_drain_session(struct nfs_client *clp)
295 {
296 	struct nfs4_session *ses = clp->cl_session;
297 	int ret;
298 
299 	if (clp->cl_slot_tbl)
300 		return nfs4_drain_slot_tbl(clp->cl_slot_tbl);
301 
302 	/* back channel */
303 	ret = nfs4_drain_slot_tbl(&ses->bc_slot_table);
304 	if (ret)
305 		return ret;
306 	/* fore channel */
307 	return nfs4_drain_slot_tbl(&ses->fc_slot_table);
308 }
309 
310 #if defined(CONFIG_NFS_V4_1)
311 
nfs41_finish_session_reset(struct nfs_client * clp)312 static void nfs41_finish_session_reset(struct nfs_client *clp)
313 {
314 	clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
315 	clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
316 	/* create_session negotiated new slot table */
317 	clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
318 	nfs4_setup_state_renewal(clp);
319 }
320 
nfs41_init_clientid(struct nfs_client * clp,const struct cred * cred)321 int nfs41_init_clientid(struct nfs_client *clp, const struct cred *cred)
322 {
323 	int status;
324 
325 	if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
326 		goto do_confirm;
327 	status = nfs4_proc_exchange_id(clp, cred);
328 	if (status != 0)
329 		goto out;
330 	set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
331 do_confirm:
332 	status = nfs4_proc_create_session(clp, cred);
333 	if (status != 0)
334 		goto out;
335 	if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R))
336 		nfs4_state_start_reclaim_reboot(clp);
337 	nfs41_finish_session_reset(clp);
338 	nfs_mark_client_ready(clp, NFS_CS_READY);
339 out:
340 	return status;
341 }
342 
343 /**
344  * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
345  *
346  * @clp: nfs_client under test
347  * @result: OUT: found nfs_client, or clp
348  * @cred: credential to use for trunking test
349  *
350  * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
351  * If NFS4_OK is returned, an nfs_client pointer is planted in
352  * "result".
353  *
354  * Note: The returned client may not yet be marked ready.
355  */
nfs41_discover_server_trunking(struct nfs_client * clp,struct nfs_client ** result,const struct cred * cred)356 int nfs41_discover_server_trunking(struct nfs_client *clp,
357 				   struct nfs_client **result,
358 				   const struct cred *cred)
359 {
360 	int status;
361 
362 	status = nfs4_proc_exchange_id(clp, cred);
363 	if (status != NFS4_OK)
364 		return status;
365 
366 	status = nfs41_walk_client_list(clp, result, cred);
367 	if (status < 0)
368 		return status;
369 	if (clp != *result)
370 		return 0;
371 
372 	/*
373 	 * Purge state if the client id was established in a prior
374 	 * instance and the client id could not have arrived on the
375 	 * server via Transparent State Migration.
376 	 */
377 	if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R) {
378 		if (!test_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags))
379 			set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
380 		else
381 			set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
382 	}
383 	nfs4_schedule_state_manager(clp);
384 	status = nfs_wait_client_init_complete(clp);
385 	if (status < 0)
386 		nfs_put_client(clp);
387 	return status;
388 }
389 
390 #endif /* CONFIG_NFS_V4_1 */
391 
392 /**
393  * nfs4_get_clid_cred - Acquire credential for a setclientid operation
394  * @clp: client state handle
395  *
396  * Returns a cred with reference count bumped, or NULL.
397  */
nfs4_get_clid_cred(struct nfs_client * clp)398 const struct cred *nfs4_get_clid_cred(struct nfs_client *clp)
399 {
400 	const struct cred *cred;
401 
402 	cred = nfs4_get_machine_cred(clp);
403 	return cred;
404 }
405 
406 static struct nfs4_state_owner *
nfs4_find_state_owner_locked(struct nfs_server * server,const struct cred * cred)407 nfs4_find_state_owner_locked(struct nfs_server *server, const struct cred *cred)
408 {
409 	struct rb_node **p = &server->state_owners.rb_node,
410 		       *parent = NULL;
411 	struct nfs4_state_owner *sp;
412 	int cmp;
413 
414 	while (*p != NULL) {
415 		parent = *p;
416 		sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
417 		cmp = cred_fscmp(cred, sp->so_cred);
418 
419 		if (cmp < 0)
420 			p = &parent->rb_left;
421 		else if (cmp > 0)
422 			p = &parent->rb_right;
423 		else {
424 			if (!list_empty(&sp->so_lru))
425 				list_del_init(&sp->so_lru);
426 			atomic_inc(&sp->so_count);
427 			return sp;
428 		}
429 	}
430 	return NULL;
431 }
432 
433 static struct nfs4_state_owner *
nfs4_insert_state_owner_locked(struct nfs4_state_owner * new)434 nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
435 {
436 	struct nfs_server *server = new->so_server;
437 	struct rb_node **p = &server->state_owners.rb_node,
438 		       *parent = NULL;
439 	struct nfs4_state_owner *sp;
440 	int cmp;
441 
442 	while (*p != NULL) {
443 		parent = *p;
444 		sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
445 		cmp = cred_fscmp(new->so_cred, sp->so_cred);
446 
447 		if (cmp < 0)
448 			p = &parent->rb_left;
449 		else if (cmp > 0)
450 			p = &parent->rb_right;
451 		else {
452 			if (!list_empty(&sp->so_lru))
453 				list_del_init(&sp->so_lru);
454 			atomic_inc(&sp->so_count);
455 			return sp;
456 		}
457 	}
458 	rb_link_node(&new->so_server_node, parent, p);
459 	rb_insert_color(&new->so_server_node, &server->state_owners);
460 	return new;
461 }
462 
463 static void
nfs4_remove_state_owner_locked(struct nfs4_state_owner * sp)464 nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
465 {
466 	struct nfs_server *server = sp->so_server;
467 
468 	if (!RB_EMPTY_NODE(&sp->so_server_node))
469 		rb_erase(&sp->so_server_node, &server->state_owners);
470 }
471 
472 static void
nfs4_init_seqid_counter(struct nfs_seqid_counter * sc)473 nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
474 {
475 	sc->create_time = ktime_get();
476 	sc->flags = 0;
477 	sc->counter = 0;
478 	spin_lock_init(&sc->lock);
479 	INIT_LIST_HEAD(&sc->list);
480 	rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
481 }
482 
483 static void
nfs4_destroy_seqid_counter(struct nfs_seqid_counter * sc)484 nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
485 {
486 	rpc_destroy_wait_queue(&sc->wait);
487 }
488 
489 /*
490  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
491  * create a new state_owner.
492  *
493  */
494 static struct nfs4_state_owner *
nfs4_alloc_state_owner(struct nfs_server * server,const struct cred * cred,gfp_t gfp_flags)495 nfs4_alloc_state_owner(struct nfs_server *server,
496 		const struct cred *cred,
497 		gfp_t gfp_flags)
498 {
499 	struct nfs4_state_owner *sp;
500 
501 	sp = kzalloc(sizeof(*sp), gfp_flags);
502 	if (!sp)
503 		return NULL;
504 	sp->so_seqid.owner_id = ida_simple_get(&server->openowner_id, 0, 0,
505 						gfp_flags);
506 	if (sp->so_seqid.owner_id < 0) {
507 		kfree(sp);
508 		return NULL;
509 	}
510 	sp->so_server = server;
511 	sp->so_cred = get_cred(cred);
512 	spin_lock_init(&sp->so_lock);
513 	INIT_LIST_HEAD(&sp->so_states);
514 	nfs4_init_seqid_counter(&sp->so_seqid);
515 	atomic_set(&sp->so_count, 1);
516 	INIT_LIST_HEAD(&sp->so_lru);
517 	seqcount_spinlock_init(&sp->so_reclaim_seqcount, &sp->so_lock);
518 	mutex_init(&sp->so_delegreturn_mutex);
519 	return sp;
520 }
521 
522 static void
nfs4_reset_state_owner(struct nfs4_state_owner * sp)523 nfs4_reset_state_owner(struct nfs4_state_owner *sp)
524 {
525 	/* This state_owner is no longer usable, but must
526 	 * remain in place so that state recovery can find it
527 	 * and the opens associated with it.
528 	 * It may also be used for new 'open' request to
529 	 * return a delegation to the server.
530 	 * So update the 'create_time' so that it looks like
531 	 * a new state_owner.  This will cause the server to
532 	 * request an OPEN_CONFIRM to start a new sequence.
533 	 */
534 	sp->so_seqid.create_time = ktime_get();
535 }
536 
nfs4_free_state_owner(struct nfs4_state_owner * sp)537 static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
538 {
539 	nfs4_destroy_seqid_counter(&sp->so_seqid);
540 	put_cred(sp->so_cred);
541 	ida_simple_remove(&sp->so_server->openowner_id, sp->so_seqid.owner_id);
542 	kfree(sp);
543 }
544 
nfs4_gc_state_owners(struct nfs_server * server)545 static void nfs4_gc_state_owners(struct nfs_server *server)
546 {
547 	struct nfs_client *clp = server->nfs_client;
548 	struct nfs4_state_owner *sp, *tmp;
549 	unsigned long time_min, time_max;
550 	LIST_HEAD(doomed);
551 
552 	spin_lock(&clp->cl_lock);
553 	time_max = jiffies;
554 	time_min = (long)time_max - (long)clp->cl_lease_time;
555 	list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
556 		/* NB: LRU is sorted so that oldest is at the head */
557 		if (time_in_range(sp->so_expires, time_min, time_max))
558 			break;
559 		list_move(&sp->so_lru, &doomed);
560 		nfs4_remove_state_owner_locked(sp);
561 	}
562 	spin_unlock(&clp->cl_lock);
563 
564 	list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
565 		list_del(&sp->so_lru);
566 		nfs4_free_state_owner(sp);
567 	}
568 }
569 
570 /**
571  * nfs4_get_state_owner - Look up a state owner given a credential
572  * @server: nfs_server to search
573  * @cred: RPC credential to match
574  * @gfp_flags: allocation mode
575  *
576  * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
577  */
nfs4_get_state_owner(struct nfs_server * server,const struct cred * cred,gfp_t gfp_flags)578 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
579 					      const struct cred *cred,
580 					      gfp_t gfp_flags)
581 {
582 	struct nfs_client *clp = server->nfs_client;
583 	struct nfs4_state_owner *sp, *new;
584 
585 	spin_lock(&clp->cl_lock);
586 	sp = nfs4_find_state_owner_locked(server, cred);
587 	spin_unlock(&clp->cl_lock);
588 	if (sp != NULL)
589 		goto out;
590 	new = nfs4_alloc_state_owner(server, cred, gfp_flags);
591 	if (new == NULL)
592 		goto out;
593 	spin_lock(&clp->cl_lock);
594 	sp = nfs4_insert_state_owner_locked(new);
595 	spin_unlock(&clp->cl_lock);
596 	if (sp != new)
597 		nfs4_free_state_owner(new);
598 out:
599 	nfs4_gc_state_owners(server);
600 	return sp;
601 }
602 
603 /**
604  * nfs4_put_state_owner - Release a nfs4_state_owner
605  * @sp: state owner data to release
606  *
607  * Note that we keep released state owners on an LRU
608  * list.
609  * This caches valid state owners so that they can be
610  * reused, to avoid the OPEN_CONFIRM on minor version 0.
611  * It also pins the uniquifier of dropped state owners for
612  * a while, to ensure that those state owner names are
613  * never reused.
614  */
nfs4_put_state_owner(struct nfs4_state_owner * sp)615 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
616 {
617 	struct nfs_server *server = sp->so_server;
618 	struct nfs_client *clp = server->nfs_client;
619 
620 	if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
621 		return;
622 
623 	sp->so_expires = jiffies;
624 	list_add_tail(&sp->so_lru, &server->state_owners_lru);
625 	spin_unlock(&clp->cl_lock);
626 }
627 
628 /**
629  * nfs4_purge_state_owners - Release all cached state owners
630  * @server: nfs_server with cached state owners to release
631  * @head: resulting list of state owners
632  *
633  * Called at umount time.  Remaining state owners will be on
634  * the LRU with ref count of zero.
635  * Note that the state owners are not freed, but are added
636  * to the list @head, which can later be used as an argument
637  * to nfs4_free_state_owners.
638  */
nfs4_purge_state_owners(struct nfs_server * server,struct list_head * head)639 void nfs4_purge_state_owners(struct nfs_server *server, struct list_head *head)
640 {
641 	struct nfs_client *clp = server->nfs_client;
642 	struct nfs4_state_owner *sp, *tmp;
643 
644 	spin_lock(&clp->cl_lock);
645 	list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
646 		list_move(&sp->so_lru, head);
647 		nfs4_remove_state_owner_locked(sp);
648 	}
649 	spin_unlock(&clp->cl_lock);
650 }
651 
652 /**
653  * nfs4_free_state_owners - Release all cached state owners
654  * @head: resulting list of state owners
655  *
656  * Frees a list of state owners that was generated by
657  * nfs4_purge_state_owners
658  */
nfs4_free_state_owners(struct list_head * head)659 void nfs4_free_state_owners(struct list_head *head)
660 {
661 	struct nfs4_state_owner *sp, *tmp;
662 
663 	list_for_each_entry_safe(sp, tmp, head, so_lru) {
664 		list_del(&sp->so_lru);
665 		nfs4_free_state_owner(sp);
666 	}
667 }
668 
669 static struct nfs4_state *
nfs4_alloc_open_state(void)670 nfs4_alloc_open_state(void)
671 {
672 	struct nfs4_state *state;
673 
674 	state = kzalloc(sizeof(*state), GFP_NOFS);
675 	if (!state)
676 		return NULL;
677 	refcount_set(&state->count, 1);
678 	INIT_LIST_HEAD(&state->lock_states);
679 	spin_lock_init(&state->state_lock);
680 	seqlock_init(&state->seqlock);
681 	init_waitqueue_head(&state->waitq);
682 	return state;
683 }
684 
685 void
nfs4_state_set_mode_locked(struct nfs4_state * state,fmode_t fmode)686 nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
687 {
688 	if (state->state == fmode)
689 		return;
690 	/* NB! List reordering - see the reclaim code for why.  */
691 	if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
692 		if (fmode & FMODE_WRITE)
693 			list_move(&state->open_states, &state->owner->so_states);
694 		else
695 			list_move_tail(&state->open_states, &state->owner->so_states);
696 	}
697 	state->state = fmode;
698 }
699 
700 static struct nfs4_state *
__nfs4_find_state_byowner(struct inode * inode,struct nfs4_state_owner * owner)701 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
702 {
703 	struct nfs_inode *nfsi = NFS_I(inode);
704 	struct nfs4_state *state;
705 
706 	list_for_each_entry_rcu(state, &nfsi->open_states, inode_states) {
707 		if (state->owner != owner)
708 			continue;
709 		if (!nfs4_valid_open_stateid(state))
710 			continue;
711 		if (refcount_inc_not_zero(&state->count))
712 			return state;
713 	}
714 	return NULL;
715 }
716 
717 static void
nfs4_free_open_state(struct nfs4_state * state)718 nfs4_free_open_state(struct nfs4_state *state)
719 {
720 	kfree_rcu(state, rcu_head);
721 }
722 
723 struct nfs4_state *
nfs4_get_open_state(struct inode * inode,struct nfs4_state_owner * owner)724 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
725 {
726 	struct nfs4_state *state, *new;
727 	struct nfs_inode *nfsi = NFS_I(inode);
728 
729 	rcu_read_lock();
730 	state = __nfs4_find_state_byowner(inode, owner);
731 	rcu_read_unlock();
732 	if (state)
733 		goto out;
734 	new = nfs4_alloc_open_state();
735 	spin_lock(&owner->so_lock);
736 	spin_lock(&inode->i_lock);
737 	state = __nfs4_find_state_byowner(inode, owner);
738 	if (state == NULL && new != NULL) {
739 		state = new;
740 		state->owner = owner;
741 		atomic_inc(&owner->so_count);
742 		ihold(inode);
743 		state->inode = inode;
744 		list_add_rcu(&state->inode_states, &nfsi->open_states);
745 		spin_unlock(&inode->i_lock);
746 		/* Note: The reclaim code dictates that we add stateless
747 		 * and read-only stateids to the end of the list */
748 		list_add_tail(&state->open_states, &owner->so_states);
749 		spin_unlock(&owner->so_lock);
750 	} else {
751 		spin_unlock(&inode->i_lock);
752 		spin_unlock(&owner->so_lock);
753 		if (new)
754 			nfs4_free_open_state(new);
755 	}
756 out:
757 	return state;
758 }
759 
nfs4_put_open_state(struct nfs4_state * state)760 void nfs4_put_open_state(struct nfs4_state *state)
761 {
762 	struct inode *inode = state->inode;
763 	struct nfs4_state_owner *owner = state->owner;
764 
765 	if (!refcount_dec_and_lock(&state->count, &owner->so_lock))
766 		return;
767 	spin_lock(&inode->i_lock);
768 	list_del_rcu(&state->inode_states);
769 	list_del(&state->open_states);
770 	spin_unlock(&inode->i_lock);
771 	spin_unlock(&owner->so_lock);
772 	nfs4_inode_return_delegation_on_close(inode);
773 	iput(inode);
774 	nfs4_free_open_state(state);
775 	nfs4_put_state_owner(owner);
776 }
777 
778 /*
779  * Close the current file.
780  */
__nfs4_close(struct nfs4_state * state,fmode_t fmode,gfp_t gfp_mask,int wait)781 static void __nfs4_close(struct nfs4_state *state,
782 		fmode_t fmode, gfp_t gfp_mask, int wait)
783 {
784 	struct nfs4_state_owner *owner = state->owner;
785 	int call_close = 0;
786 	fmode_t newstate;
787 
788 	atomic_inc(&owner->so_count);
789 	/* Protect against nfs4_find_state() */
790 	spin_lock(&owner->so_lock);
791 	switch (fmode & (FMODE_READ | FMODE_WRITE)) {
792 		case FMODE_READ:
793 			state->n_rdonly--;
794 			break;
795 		case FMODE_WRITE:
796 			state->n_wronly--;
797 			break;
798 		case FMODE_READ|FMODE_WRITE:
799 			state->n_rdwr--;
800 	}
801 	newstate = FMODE_READ|FMODE_WRITE;
802 	if (state->n_rdwr == 0) {
803 		if (state->n_rdonly == 0) {
804 			newstate &= ~FMODE_READ;
805 			call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
806 			call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
807 		}
808 		if (state->n_wronly == 0) {
809 			newstate &= ~FMODE_WRITE;
810 			call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
811 			call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
812 		}
813 		if (newstate == 0)
814 			clear_bit(NFS_DELEGATED_STATE, &state->flags);
815 	}
816 	nfs4_state_set_mode_locked(state, newstate);
817 	spin_unlock(&owner->so_lock);
818 
819 	if (!call_close) {
820 		nfs4_put_open_state(state);
821 		nfs4_put_state_owner(owner);
822 	} else
823 		nfs4_do_close(state, gfp_mask, wait);
824 }
825 
nfs4_close_state(struct nfs4_state * state,fmode_t fmode)826 void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
827 {
828 	__nfs4_close(state, fmode, GFP_KERNEL, 0);
829 }
830 
nfs4_close_sync(struct nfs4_state * state,fmode_t fmode)831 void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
832 {
833 	__nfs4_close(state, fmode, GFP_KERNEL, 1);
834 }
835 
836 /*
837  * Search the state->lock_states for an existing lock_owner
838  * that is compatible with either of the given owners.
839  * If the second is non-zero, then the first refers to a Posix-lock
840  * owner (current->files) and the second refers to a flock/OFD
841  * owner (struct file*).  In that case, prefer a match for the first
842  * owner.
843  * If both sorts of locks are held on the one file we cannot know
844  * which stateid was intended to be used, so a "correct" choice cannot
845  * be made.  Failing that, a "consistent" choice is preferable.  The
846  * consistent choice we make is to prefer the first owner, that of a
847  * Posix lock.
848  */
849 static struct nfs4_lock_state *
__nfs4_find_lock_state(struct nfs4_state * state,fl_owner_t fl_owner,fl_owner_t fl_owner2)850 __nfs4_find_lock_state(struct nfs4_state *state,
851 		       fl_owner_t fl_owner, fl_owner_t fl_owner2)
852 {
853 	struct nfs4_lock_state *pos, *ret = NULL;
854 	list_for_each_entry(pos, &state->lock_states, ls_locks) {
855 		if (pos->ls_owner == fl_owner) {
856 			ret = pos;
857 			break;
858 		}
859 		if (pos->ls_owner == fl_owner2)
860 			ret = pos;
861 	}
862 	if (ret)
863 		refcount_inc(&ret->ls_count);
864 	return ret;
865 }
866 
867 /*
868  * Return a compatible lock_state. If no initialized lock_state structure
869  * exists, return an uninitialized one.
870  *
871  */
nfs4_alloc_lock_state(struct nfs4_state * state,fl_owner_t fl_owner)872 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
873 {
874 	struct nfs4_lock_state *lsp;
875 	struct nfs_server *server = state->owner->so_server;
876 
877 	lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
878 	if (lsp == NULL)
879 		return NULL;
880 	nfs4_init_seqid_counter(&lsp->ls_seqid);
881 	refcount_set(&lsp->ls_count, 1);
882 	lsp->ls_state = state;
883 	lsp->ls_owner = fl_owner;
884 	lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
885 	if (lsp->ls_seqid.owner_id < 0)
886 		goto out_free;
887 	INIT_LIST_HEAD(&lsp->ls_locks);
888 	return lsp;
889 out_free:
890 	kfree(lsp);
891 	return NULL;
892 }
893 
nfs4_free_lock_state(struct nfs_server * server,struct nfs4_lock_state * lsp)894 void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
895 {
896 	ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
897 	nfs4_destroy_seqid_counter(&lsp->ls_seqid);
898 	kfree(lsp);
899 }
900 
901 /*
902  * Return a compatible lock_state. If no initialized lock_state structure
903  * exists, return an uninitialized one.
904  *
905  */
nfs4_get_lock_state(struct nfs4_state * state,fl_owner_t owner)906 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
907 {
908 	struct nfs4_lock_state *lsp, *new = NULL;
909 
910 	for(;;) {
911 		spin_lock(&state->state_lock);
912 		lsp = __nfs4_find_lock_state(state, owner, NULL);
913 		if (lsp != NULL)
914 			break;
915 		if (new != NULL) {
916 			list_add(&new->ls_locks, &state->lock_states);
917 			set_bit(LK_STATE_IN_USE, &state->flags);
918 			lsp = new;
919 			new = NULL;
920 			break;
921 		}
922 		spin_unlock(&state->state_lock);
923 		new = nfs4_alloc_lock_state(state, owner);
924 		if (new == NULL)
925 			return NULL;
926 	}
927 	spin_unlock(&state->state_lock);
928 	if (new != NULL)
929 		nfs4_free_lock_state(state->owner->so_server, new);
930 	return lsp;
931 }
932 
933 /*
934  * Release reference to lock_state, and free it if we see that
935  * it is no longer in use
936  */
nfs4_put_lock_state(struct nfs4_lock_state * lsp)937 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
938 {
939 	struct nfs_server *server;
940 	struct nfs4_state *state;
941 
942 	if (lsp == NULL)
943 		return;
944 	state = lsp->ls_state;
945 	if (!refcount_dec_and_lock(&lsp->ls_count, &state->state_lock))
946 		return;
947 	list_del(&lsp->ls_locks);
948 	if (list_empty(&state->lock_states))
949 		clear_bit(LK_STATE_IN_USE, &state->flags);
950 	spin_unlock(&state->state_lock);
951 	server = state->owner->so_server;
952 	if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
953 		struct nfs_client *clp = server->nfs_client;
954 
955 		clp->cl_mvops->free_lock_state(server, lsp);
956 	} else
957 		nfs4_free_lock_state(server, lsp);
958 }
959 
nfs4_fl_copy_lock(struct file_lock * dst,struct file_lock * src)960 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
961 {
962 	struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
963 
964 	dst->fl_u.nfs4_fl.owner = lsp;
965 	refcount_inc(&lsp->ls_count);
966 }
967 
nfs4_fl_release_lock(struct file_lock * fl)968 static void nfs4_fl_release_lock(struct file_lock *fl)
969 {
970 	nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
971 }
972 
973 static const struct file_lock_operations nfs4_fl_lock_ops = {
974 	.fl_copy_lock = nfs4_fl_copy_lock,
975 	.fl_release_private = nfs4_fl_release_lock,
976 };
977 
nfs4_set_lock_state(struct nfs4_state * state,struct file_lock * fl)978 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
979 {
980 	struct nfs4_lock_state *lsp;
981 
982 	if (fl->fl_ops != NULL)
983 		return 0;
984 	lsp = nfs4_get_lock_state(state, fl->fl_owner);
985 	if (lsp == NULL)
986 		return -ENOMEM;
987 	fl->fl_u.nfs4_fl.owner = lsp;
988 	fl->fl_ops = &nfs4_fl_lock_ops;
989 	return 0;
990 }
991 
nfs4_copy_lock_stateid(nfs4_stateid * dst,struct nfs4_state * state,const struct nfs_lock_context * l_ctx)992 static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
993 		struct nfs4_state *state,
994 		const struct nfs_lock_context *l_ctx)
995 {
996 	struct nfs4_lock_state *lsp;
997 	fl_owner_t fl_owner, fl_flock_owner;
998 	int ret = -ENOENT;
999 
1000 	if (l_ctx == NULL)
1001 		goto out;
1002 
1003 	if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
1004 		goto out;
1005 
1006 	fl_owner = l_ctx->lockowner;
1007 	fl_flock_owner = l_ctx->open_context->flock_owner;
1008 
1009 	spin_lock(&state->state_lock);
1010 	lsp = __nfs4_find_lock_state(state, fl_owner, fl_flock_owner);
1011 	if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
1012 		ret = -EIO;
1013 	else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
1014 		nfs4_stateid_copy(dst, &lsp->ls_stateid);
1015 		ret = 0;
1016 	}
1017 	spin_unlock(&state->state_lock);
1018 	nfs4_put_lock_state(lsp);
1019 out:
1020 	return ret;
1021 }
1022 
nfs4_copy_open_stateid(nfs4_stateid * dst,struct nfs4_state * state)1023 bool nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1024 {
1025 	bool ret;
1026 	const nfs4_stateid *src;
1027 	int seq;
1028 
1029 	do {
1030 		ret = false;
1031 		src = &zero_stateid;
1032 		seq = read_seqbegin(&state->seqlock);
1033 		if (test_bit(NFS_OPEN_STATE, &state->flags)) {
1034 			src = &state->open_stateid;
1035 			ret = true;
1036 		}
1037 		nfs4_stateid_copy(dst, src);
1038 	} while (read_seqretry(&state->seqlock, seq));
1039 	return ret;
1040 }
1041 
1042 /*
1043  * Byte-range lock aware utility to initialize the stateid of read/write
1044  * requests.
1045  */
nfs4_select_rw_stateid(struct nfs4_state * state,fmode_t fmode,const struct nfs_lock_context * l_ctx,nfs4_stateid * dst,const struct cred ** cred)1046 int nfs4_select_rw_stateid(struct nfs4_state *state,
1047 		fmode_t fmode, const struct nfs_lock_context *l_ctx,
1048 		nfs4_stateid *dst, const struct cred **cred)
1049 {
1050 	int ret;
1051 
1052 	if (!nfs4_valid_open_stateid(state))
1053 		return -EIO;
1054 	if (cred != NULL)
1055 		*cred = NULL;
1056 	ret = nfs4_copy_lock_stateid(dst, state, l_ctx);
1057 	if (ret == -EIO)
1058 		/* A lost lock - don't even consider delegations */
1059 		goto out;
1060 	/* returns true if delegation stateid found and copied */
1061 	if (nfs4_copy_delegation_stateid(state->inode, fmode, dst, cred)) {
1062 		ret = 0;
1063 		goto out;
1064 	}
1065 	if (ret != -ENOENT)
1066 		/* nfs4_copy_delegation_stateid() didn't over-write
1067 		 * dst, so it still has the lock stateid which we now
1068 		 * choose to use.
1069 		 */
1070 		goto out;
1071 	ret = nfs4_copy_open_stateid(dst, state) ? 0 : -EAGAIN;
1072 out:
1073 	if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1074 		dst->seqid = 0;
1075 	return ret;
1076 }
1077 
nfs_alloc_seqid(struct nfs_seqid_counter * counter,gfp_t gfp_mask)1078 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1079 {
1080 	struct nfs_seqid *new;
1081 
1082 	new = kmalloc(sizeof(*new), gfp_mask);
1083 	if (new == NULL)
1084 		return ERR_PTR(-ENOMEM);
1085 	new->sequence = counter;
1086 	INIT_LIST_HEAD(&new->list);
1087 	new->task = NULL;
1088 	return new;
1089 }
1090 
nfs_release_seqid(struct nfs_seqid * seqid)1091 void nfs_release_seqid(struct nfs_seqid *seqid)
1092 {
1093 	struct nfs_seqid_counter *sequence;
1094 
1095 	if (seqid == NULL || list_empty(&seqid->list))
1096 		return;
1097 	sequence = seqid->sequence;
1098 	spin_lock(&sequence->lock);
1099 	list_del_init(&seqid->list);
1100 	if (!list_empty(&sequence->list)) {
1101 		struct nfs_seqid *next;
1102 
1103 		next = list_first_entry(&sequence->list,
1104 				struct nfs_seqid, list);
1105 		rpc_wake_up_queued_task(&sequence->wait, next->task);
1106 	}
1107 	spin_unlock(&sequence->lock);
1108 }
1109 
nfs_free_seqid(struct nfs_seqid * seqid)1110 void nfs_free_seqid(struct nfs_seqid *seqid)
1111 {
1112 	nfs_release_seqid(seqid);
1113 	kfree(seqid);
1114 }
1115 
1116 /*
1117  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1118  * failed with a seqid incrementing error -
1119  * see comments nfs4.h:seqid_mutating_error()
1120  */
nfs_increment_seqid(int status,struct nfs_seqid * seqid)1121 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1122 {
1123 	switch (status) {
1124 		case 0:
1125 			break;
1126 		case -NFS4ERR_BAD_SEQID:
1127 			if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1128 				return;
1129 			pr_warn_ratelimited("NFS: v4 server returned a bad"
1130 					" sequence-id error on an"
1131 					" unconfirmed sequence %p!\n",
1132 					seqid->sequence);
1133 			return;
1134 		case -NFS4ERR_STALE_CLIENTID:
1135 		case -NFS4ERR_STALE_STATEID:
1136 		case -NFS4ERR_BAD_STATEID:
1137 		case -NFS4ERR_BADXDR:
1138 		case -NFS4ERR_RESOURCE:
1139 		case -NFS4ERR_NOFILEHANDLE:
1140 		case -NFS4ERR_MOVED:
1141 			/* Non-seqid mutating errors */
1142 			return;
1143 	}
1144 	/*
1145 	 * Note: no locking needed as we are guaranteed to be first
1146 	 * on the sequence list
1147 	 */
1148 	seqid->sequence->counter++;
1149 }
1150 
nfs_increment_open_seqid(int status,struct nfs_seqid * seqid)1151 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1152 {
1153 	struct nfs4_state_owner *sp;
1154 
1155 	if (seqid == NULL)
1156 		return;
1157 
1158 	sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1159 	if (status == -NFS4ERR_BAD_SEQID)
1160 		nfs4_reset_state_owner(sp);
1161 	if (!nfs4_has_session(sp->so_server->nfs_client))
1162 		nfs_increment_seqid(status, seqid);
1163 }
1164 
1165 /*
1166  * Increment the seqid if the LOCK/LOCKU succeeded, or
1167  * failed with a seqid incrementing error -
1168  * see comments nfs4.h:seqid_mutating_error()
1169  */
nfs_increment_lock_seqid(int status,struct nfs_seqid * seqid)1170 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1171 {
1172 	if (seqid != NULL)
1173 		nfs_increment_seqid(status, seqid);
1174 }
1175 
nfs_wait_on_sequence(struct nfs_seqid * seqid,struct rpc_task * task)1176 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1177 {
1178 	struct nfs_seqid_counter *sequence;
1179 	int status = 0;
1180 
1181 	if (seqid == NULL)
1182 		goto out;
1183 	sequence = seqid->sequence;
1184 	spin_lock(&sequence->lock);
1185 	seqid->task = task;
1186 	if (list_empty(&seqid->list))
1187 		list_add_tail(&seqid->list, &sequence->list);
1188 	if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1189 		goto unlock;
1190 	rpc_sleep_on(&sequence->wait, task, NULL);
1191 	status = -EAGAIN;
1192 unlock:
1193 	spin_unlock(&sequence->lock);
1194 out:
1195 	return status;
1196 }
1197 
1198 static int nfs4_run_state_manager(void *);
1199 
nfs4_clear_state_manager_bit(struct nfs_client * clp)1200 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1201 {
1202 	smp_mb__before_atomic();
1203 	clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1204 	smp_mb__after_atomic();
1205 	wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1206 	rpc_wake_up(&clp->cl_rpcwaitq);
1207 }
1208 
1209 /*
1210  * Schedule the nfs_client asynchronous state management routine
1211  */
nfs4_schedule_state_manager(struct nfs_client * clp)1212 void nfs4_schedule_state_manager(struct nfs_client *clp)
1213 {
1214 	struct task_struct *task;
1215 	char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1216 	struct rpc_clnt *clnt = clp->cl_rpcclient;
1217 	bool swapon = false;
1218 
1219 	set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
1220 
1221 	if (atomic_read(&clnt->cl_swapper)) {
1222 		swapon = !test_and_set_bit(NFS4CLNT_MANAGER_AVAILABLE,
1223 					   &clp->cl_state);
1224 		if (!swapon) {
1225 			wake_up_var(&clp->cl_state);
1226 			return;
1227 		}
1228 	}
1229 
1230 	if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1231 		return;
1232 
1233 	__module_get(THIS_MODULE);
1234 	refcount_inc(&clp->cl_count);
1235 
1236 	/* The rcu_read_lock() is not strictly necessary, as the state
1237 	 * manager is the only thread that ever changes the rpc_xprt
1238 	 * after it's initialized.  At this point, we're single threaded. */
1239 	rcu_read_lock();
1240 	snprintf(buf, sizeof(buf), "%s-manager",
1241 			rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1242 	rcu_read_unlock();
1243 	task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1244 	if (IS_ERR(task)) {
1245 		printk(KERN_ERR "%s: kthread_run: %ld\n",
1246 			__func__, PTR_ERR(task));
1247 		if (!nfs_client_init_is_complete(clp))
1248 			nfs_mark_client_ready(clp, PTR_ERR(task));
1249 		if (swapon)
1250 			clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
1251 		nfs4_clear_state_manager_bit(clp);
1252 		nfs_put_client(clp);
1253 		module_put(THIS_MODULE);
1254 	}
1255 }
1256 
1257 /*
1258  * Schedule a lease recovery attempt
1259  */
nfs4_schedule_lease_recovery(struct nfs_client * clp)1260 void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1261 {
1262 	if (!clp)
1263 		return;
1264 	if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1265 		set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1266 	dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1267 			clp->cl_hostname);
1268 	nfs4_schedule_state_manager(clp);
1269 }
1270 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1271 
1272 /**
1273  * nfs4_schedule_migration_recovery - trigger migration recovery
1274  *
1275  * @server: FSID that is migrating
1276  *
1277  * Returns zero if recovery has started, otherwise a negative NFS4ERR
1278  * value is returned.
1279  */
nfs4_schedule_migration_recovery(const struct nfs_server * server)1280 int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1281 {
1282 	struct nfs_client *clp = server->nfs_client;
1283 
1284 	if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1285 		pr_err("NFS: volatile file handles not supported (server %s)\n",
1286 				clp->cl_hostname);
1287 		return -NFS4ERR_IO;
1288 	}
1289 
1290 	if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1291 		return -NFS4ERR_IO;
1292 
1293 	dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1294 			__func__,
1295 			(unsigned long long)server->fsid.major,
1296 			(unsigned long long)server->fsid.minor,
1297 			clp->cl_hostname);
1298 
1299 	set_bit(NFS_MIG_IN_TRANSITION,
1300 			&((struct nfs_server *)server)->mig_status);
1301 	set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1302 
1303 	nfs4_schedule_state_manager(clp);
1304 	return 0;
1305 }
1306 EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1307 
1308 /**
1309  * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1310  *
1311  * @clp: server to check for moved leases
1312  *
1313  */
nfs4_schedule_lease_moved_recovery(struct nfs_client * clp)1314 void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1315 {
1316 	dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1317 		__func__, clp->cl_clientid, clp->cl_hostname);
1318 
1319 	set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1320 	nfs4_schedule_state_manager(clp);
1321 }
1322 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1323 
nfs4_wait_clnt_recover(struct nfs_client * clp)1324 int nfs4_wait_clnt_recover(struct nfs_client *clp)
1325 {
1326 	int res;
1327 
1328 	might_sleep();
1329 
1330 	refcount_inc(&clp->cl_count);
1331 	res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1332 				 nfs_wait_bit_killable, TASK_KILLABLE);
1333 	if (res)
1334 		goto out;
1335 	if (clp->cl_cons_state < 0)
1336 		res = clp->cl_cons_state;
1337 out:
1338 	nfs_put_client(clp);
1339 	return res;
1340 }
1341 
nfs4_client_recover_expired_lease(struct nfs_client * clp)1342 int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1343 {
1344 	unsigned int loop;
1345 	int ret;
1346 
1347 	for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1348 		ret = nfs4_wait_clnt_recover(clp);
1349 		if (ret != 0)
1350 			break;
1351 		if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1352 		    !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1353 			break;
1354 		nfs4_schedule_state_manager(clp);
1355 		ret = -EIO;
1356 	}
1357 	return ret;
1358 }
1359 
1360 /*
1361  * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1362  * @clp: client to process
1363  *
1364  * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1365  * resend of the SETCLIENTID and hence re-establish the
1366  * callback channel. Then return all existing delegations.
1367  */
nfs40_handle_cb_pathdown(struct nfs_client * clp)1368 static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1369 {
1370 	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1371 	nfs_expire_all_delegations(clp);
1372 	dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1373 			clp->cl_hostname);
1374 }
1375 
nfs4_schedule_path_down_recovery(struct nfs_client * clp)1376 void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1377 {
1378 	nfs40_handle_cb_pathdown(clp);
1379 	nfs4_schedule_state_manager(clp);
1380 }
1381 
nfs4_state_mark_reclaim_reboot(struct nfs_client * clp,struct nfs4_state * state)1382 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1383 {
1384 
1385 	if (!nfs4_valid_open_stateid(state))
1386 		return 0;
1387 	set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1388 	/* Don't recover state that expired before the reboot */
1389 	if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1390 		clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1391 		return 0;
1392 	}
1393 	set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1394 	set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1395 	return 1;
1396 }
1397 
nfs4_state_mark_reclaim_nograce(struct nfs_client * clp,struct nfs4_state * state)1398 int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1399 {
1400 	if (!nfs4_valid_open_stateid(state))
1401 		return 0;
1402 	set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1403 	clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1404 	set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1405 	set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1406 	return 1;
1407 }
1408 
nfs4_schedule_stateid_recovery(const struct nfs_server * server,struct nfs4_state * state)1409 int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1410 {
1411 	struct nfs_client *clp = server->nfs_client;
1412 
1413 	if (!nfs4_state_mark_reclaim_nograce(clp, state))
1414 		return -EBADF;
1415 	nfs_inode_find_delegation_state_and_recover(state->inode,
1416 			&state->stateid);
1417 	dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1418 			clp->cl_hostname);
1419 	nfs4_schedule_state_manager(clp);
1420 	return 0;
1421 }
1422 EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1423 
1424 static struct nfs4_lock_state *
nfs_state_find_lock_state_by_stateid(struct nfs4_state * state,const nfs4_stateid * stateid)1425 nfs_state_find_lock_state_by_stateid(struct nfs4_state *state,
1426 		const nfs4_stateid *stateid)
1427 {
1428 	struct nfs4_lock_state *pos;
1429 
1430 	list_for_each_entry(pos, &state->lock_states, ls_locks) {
1431 		if (!test_bit(NFS_LOCK_INITIALIZED, &pos->ls_flags))
1432 			continue;
1433 		if (nfs4_stateid_match_or_older(&pos->ls_stateid, stateid))
1434 			return pos;
1435 	}
1436 	return NULL;
1437 }
1438 
nfs_state_lock_state_matches_stateid(struct nfs4_state * state,const nfs4_stateid * stateid)1439 static bool nfs_state_lock_state_matches_stateid(struct nfs4_state *state,
1440 		const nfs4_stateid *stateid)
1441 {
1442 	bool found = false;
1443 
1444 	if (test_bit(LK_STATE_IN_USE, &state->flags)) {
1445 		spin_lock(&state->state_lock);
1446 		if (nfs_state_find_lock_state_by_stateid(state, stateid))
1447 			found = true;
1448 		spin_unlock(&state->state_lock);
1449 	}
1450 	return found;
1451 }
1452 
nfs_inode_find_state_and_recover(struct inode * inode,const nfs4_stateid * stateid)1453 void nfs_inode_find_state_and_recover(struct inode *inode,
1454 		const nfs4_stateid *stateid)
1455 {
1456 	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1457 	struct nfs_inode *nfsi = NFS_I(inode);
1458 	struct nfs_open_context *ctx;
1459 	struct nfs4_state *state;
1460 	bool found = false;
1461 
1462 	rcu_read_lock();
1463 	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1464 		state = ctx->state;
1465 		if (state == NULL)
1466 			continue;
1467 		if (nfs4_stateid_match_or_older(&state->stateid, stateid) &&
1468 		    nfs4_state_mark_reclaim_nograce(clp, state)) {
1469 			found = true;
1470 			continue;
1471 		}
1472 		if (test_bit(NFS_OPEN_STATE, &state->flags) &&
1473 		    nfs4_stateid_match_or_older(&state->open_stateid, stateid) &&
1474 		    nfs4_state_mark_reclaim_nograce(clp, state)) {
1475 			found = true;
1476 			continue;
1477 		}
1478 		if (nfs_state_lock_state_matches_stateid(state, stateid) &&
1479 		    nfs4_state_mark_reclaim_nograce(clp, state))
1480 			found = true;
1481 	}
1482 	rcu_read_unlock();
1483 
1484 	nfs_inode_find_delegation_state_and_recover(inode, stateid);
1485 	if (found)
1486 		nfs4_schedule_state_manager(clp);
1487 }
1488 
nfs4_state_mark_open_context_bad(struct nfs4_state * state,int err)1489 static void nfs4_state_mark_open_context_bad(struct nfs4_state *state, int err)
1490 {
1491 	struct inode *inode = state->inode;
1492 	struct nfs_inode *nfsi = NFS_I(inode);
1493 	struct nfs_open_context *ctx;
1494 
1495 	rcu_read_lock();
1496 	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1497 		if (ctx->state != state)
1498 			continue;
1499 		set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1500 		pr_warn("NFSv4: state recovery failed for open file %pd2, "
1501 				"error = %d\n", ctx->dentry, err);
1502 	}
1503 	rcu_read_unlock();
1504 }
1505 
nfs4_state_mark_recovery_failed(struct nfs4_state * state,int error)1506 static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1507 {
1508 	set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1509 	nfs4_state_mark_open_context_bad(state, error);
1510 }
1511 
1512 
nfs4_reclaim_locks(struct nfs4_state * state,const struct nfs4_state_recovery_ops * ops)1513 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1514 {
1515 	struct inode *inode = state->inode;
1516 	struct nfs_inode *nfsi = NFS_I(inode);
1517 	struct file_lock *fl;
1518 	struct nfs4_lock_state *lsp;
1519 	int status = 0;
1520 	struct file_lock_context *flctx = inode->i_flctx;
1521 	struct list_head *list;
1522 
1523 	if (flctx == NULL)
1524 		return 0;
1525 
1526 	list = &flctx->flc_posix;
1527 
1528 	/* Guard against delegation returns and new lock/unlock calls */
1529 	down_write(&nfsi->rwsem);
1530 	spin_lock(&flctx->flc_lock);
1531 restart:
1532 	list_for_each_entry(fl, list, fl_list) {
1533 		if (nfs_file_open_context(fl->fl_file)->state != state)
1534 			continue;
1535 		spin_unlock(&flctx->flc_lock);
1536 		status = ops->recover_lock(state, fl);
1537 		switch (status) {
1538 		case 0:
1539 			break;
1540 		case -ETIMEDOUT:
1541 		case -ESTALE:
1542 		case -NFS4ERR_ADMIN_REVOKED:
1543 		case -NFS4ERR_STALE_STATEID:
1544 		case -NFS4ERR_BAD_STATEID:
1545 		case -NFS4ERR_EXPIRED:
1546 		case -NFS4ERR_NO_GRACE:
1547 		case -NFS4ERR_STALE_CLIENTID:
1548 		case -NFS4ERR_BADSESSION:
1549 		case -NFS4ERR_BADSLOT:
1550 		case -NFS4ERR_BAD_HIGH_SLOT:
1551 		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1552 			goto out;
1553 		default:
1554 			pr_err("NFS: %s: unhandled error %d\n",
1555 					__func__, status);
1556 			fallthrough;
1557 		case -ENOMEM:
1558 		case -NFS4ERR_DENIED:
1559 		case -NFS4ERR_RECLAIM_BAD:
1560 		case -NFS4ERR_RECLAIM_CONFLICT:
1561 			lsp = fl->fl_u.nfs4_fl.owner;
1562 			if (lsp)
1563 				set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
1564 			status = 0;
1565 		}
1566 		spin_lock(&flctx->flc_lock);
1567 	}
1568 	if (list == &flctx->flc_posix) {
1569 		list = &flctx->flc_flock;
1570 		goto restart;
1571 	}
1572 	spin_unlock(&flctx->flc_lock);
1573 out:
1574 	up_write(&nfsi->rwsem);
1575 	return status;
1576 }
1577 
1578 #ifdef CONFIG_NFS_V4_2
nfs42_complete_copies(struct nfs4_state_owner * sp,struct nfs4_state * state)1579 static void nfs42_complete_copies(struct nfs4_state_owner *sp, struct nfs4_state *state)
1580 {
1581 	struct nfs4_copy_state *copy;
1582 
1583 	if (!test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags) &&
1584 		!test_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags))
1585 		return;
1586 
1587 	spin_lock(&sp->so_server->nfs_client->cl_lock);
1588 	list_for_each_entry(copy, &sp->so_server->ss_copies, copies) {
1589 		if ((test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags) &&
1590 				!nfs4_stateid_match_other(&state->stateid,
1591 				&copy->parent_dst_state->stateid)))
1592 				continue;
1593 		copy->flags = 1;
1594 		if (test_and_clear_bit(NFS_CLNT_DST_SSC_COPY_STATE,
1595 				&state->flags)) {
1596 			clear_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags);
1597 			complete(&copy->completion);
1598 		}
1599 	}
1600 	list_for_each_entry(copy, &sp->so_server->ss_copies, src_copies) {
1601 		if ((test_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags) &&
1602 				!nfs4_stateid_match_other(&state->stateid,
1603 				&copy->parent_src_state->stateid)))
1604 				continue;
1605 		copy->flags = 1;
1606 		if (test_and_clear_bit(NFS_CLNT_DST_SSC_COPY_STATE,
1607 				&state->flags))
1608 			complete(&copy->completion);
1609 	}
1610 	spin_unlock(&sp->so_server->nfs_client->cl_lock);
1611 }
1612 #else /* !CONFIG_NFS_V4_2 */
nfs42_complete_copies(struct nfs4_state_owner * sp,struct nfs4_state * state)1613 static inline void nfs42_complete_copies(struct nfs4_state_owner *sp,
1614 					 struct nfs4_state *state)
1615 {
1616 }
1617 #endif /* CONFIG_NFS_V4_2 */
1618 
__nfs4_reclaim_open_state(struct nfs4_state_owner * sp,struct nfs4_state * state,const struct nfs4_state_recovery_ops * ops)1619 static int __nfs4_reclaim_open_state(struct nfs4_state_owner *sp, struct nfs4_state *state,
1620 				     const struct nfs4_state_recovery_ops *ops)
1621 {
1622 	struct nfs4_lock_state *lock;
1623 	int status;
1624 
1625 	status = ops->recover_open(sp, state);
1626 	if (status < 0)
1627 		return status;
1628 
1629 	status = nfs4_reclaim_locks(state, ops);
1630 	if (status < 0)
1631 		return status;
1632 
1633 	if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1634 		spin_lock(&state->state_lock);
1635 		list_for_each_entry(lock, &state->lock_states, ls_locks) {
1636 			trace_nfs4_state_lock_reclaim(state, lock);
1637 			if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1638 				pr_warn_ratelimited("NFS: %s: Lock reclaim failed!\n", __func__);
1639 		}
1640 		spin_unlock(&state->state_lock);
1641 	}
1642 
1643 	nfs42_complete_copies(sp, state);
1644 	clear_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1645 	return status;
1646 }
1647 
nfs4_reclaim_open_state(struct nfs4_state_owner * sp,const struct nfs4_state_recovery_ops * ops)1648 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1649 {
1650 	struct nfs4_state *state;
1651 	unsigned int loop = 0;
1652 	int status = 0;
1653 #ifdef CONFIG_NFS_V4_2
1654 	bool found_ssc_copy_state = false;
1655 #endif /* CONFIG_NFS_V4_2 */
1656 
1657 	/* Note: we rely on the sp->so_states list being ordered
1658 	 * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1659 	 * states first.
1660 	 * This is needed to ensure that the server won't give us any
1661 	 * read delegations that we have to return if, say, we are
1662 	 * recovering after a network partition or a reboot from a
1663 	 * server that doesn't support a grace period.
1664 	 */
1665 	spin_lock(&sp->so_lock);
1666 	raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1667 restart:
1668 	list_for_each_entry(state, &sp->so_states, open_states) {
1669 		if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1670 			continue;
1671 		if (!nfs4_valid_open_stateid(state))
1672 			continue;
1673 		if (state->state == 0)
1674 			continue;
1675 #ifdef CONFIG_NFS_V4_2
1676 		if (test_bit(NFS_SRV_SSC_COPY_STATE, &state->flags)) {
1677 			nfs4_state_mark_recovery_failed(state, -EIO);
1678 			found_ssc_copy_state = true;
1679 			continue;
1680 		}
1681 #endif /* CONFIG_NFS_V4_2 */
1682 		refcount_inc(&state->count);
1683 		spin_unlock(&sp->so_lock);
1684 		status = __nfs4_reclaim_open_state(sp, state, ops);
1685 
1686 		switch (status) {
1687 		default:
1688 			if (status >= 0) {
1689 				loop = 0;
1690 				break;
1691 			}
1692 			printk(KERN_ERR "NFS: %s: unhandled error %d\n", __func__, status);
1693 			fallthrough;
1694 		case -ENOENT:
1695 		case -ENOMEM:
1696 		case -EACCES:
1697 		case -EROFS:
1698 		case -EIO:
1699 		case -ESTALE:
1700 			/* Open state on this file cannot be recovered */
1701 			nfs4_state_mark_recovery_failed(state, status);
1702 			break;
1703 		case -EAGAIN:
1704 			ssleep(1);
1705 			if (loop++ < 10) {
1706 				set_bit(ops->state_flag_bit, &state->flags);
1707 				break;
1708 			}
1709 			fallthrough;
1710 		case -NFS4ERR_ADMIN_REVOKED:
1711 		case -NFS4ERR_STALE_STATEID:
1712 		case -NFS4ERR_OLD_STATEID:
1713 		case -NFS4ERR_BAD_STATEID:
1714 		case -NFS4ERR_RECLAIM_BAD:
1715 		case -NFS4ERR_RECLAIM_CONFLICT:
1716 			nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1717 			break;
1718 		case -NFS4ERR_EXPIRED:
1719 		case -NFS4ERR_NO_GRACE:
1720 			nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1721 			fallthrough;
1722 		case -NFS4ERR_STALE_CLIENTID:
1723 		case -NFS4ERR_BADSESSION:
1724 		case -NFS4ERR_BADSLOT:
1725 		case -NFS4ERR_BAD_HIGH_SLOT:
1726 		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1727 		case -ETIMEDOUT:
1728 			goto out_err;
1729 		}
1730 		nfs4_put_open_state(state);
1731 		spin_lock(&sp->so_lock);
1732 		goto restart;
1733 	}
1734 	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1735 	spin_unlock(&sp->so_lock);
1736 #ifdef CONFIG_NFS_V4_2
1737 	if (found_ssc_copy_state)
1738 		return -EIO;
1739 #endif /* CONFIG_NFS_V4_2 */
1740 	return 0;
1741 out_err:
1742 	nfs4_put_open_state(state);
1743 	spin_lock(&sp->so_lock);
1744 	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1745 	spin_unlock(&sp->so_lock);
1746 	return status;
1747 }
1748 
nfs4_clear_open_state(struct nfs4_state * state)1749 static void nfs4_clear_open_state(struct nfs4_state *state)
1750 {
1751 	struct nfs4_lock_state *lock;
1752 
1753 	clear_bit(NFS_DELEGATED_STATE, &state->flags);
1754 	clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1755 	clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1756 	clear_bit(NFS_O_RDWR_STATE, &state->flags);
1757 	spin_lock(&state->state_lock);
1758 	list_for_each_entry(lock, &state->lock_states, ls_locks) {
1759 		lock->ls_seqid.flags = 0;
1760 		clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1761 	}
1762 	spin_unlock(&state->state_lock);
1763 }
1764 
nfs4_reset_seqids(struct nfs_server * server,int (* mark_reclaim)(struct nfs_client * clp,struct nfs4_state * state))1765 static void nfs4_reset_seqids(struct nfs_server *server,
1766 	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1767 {
1768 	struct nfs_client *clp = server->nfs_client;
1769 	struct nfs4_state_owner *sp;
1770 	struct rb_node *pos;
1771 	struct nfs4_state *state;
1772 
1773 	spin_lock(&clp->cl_lock);
1774 	for (pos = rb_first(&server->state_owners);
1775 	     pos != NULL;
1776 	     pos = rb_next(pos)) {
1777 		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1778 		sp->so_seqid.flags = 0;
1779 		spin_lock(&sp->so_lock);
1780 		list_for_each_entry(state, &sp->so_states, open_states) {
1781 			if (mark_reclaim(clp, state))
1782 				nfs4_clear_open_state(state);
1783 		}
1784 		spin_unlock(&sp->so_lock);
1785 	}
1786 	spin_unlock(&clp->cl_lock);
1787 }
1788 
nfs4_state_mark_reclaim_helper(struct nfs_client * clp,int (* mark_reclaim)(struct nfs_client * clp,struct nfs4_state * state))1789 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1790 	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1791 {
1792 	struct nfs_server *server;
1793 
1794 	rcu_read_lock();
1795 	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1796 		nfs4_reset_seqids(server, mark_reclaim);
1797 	rcu_read_unlock();
1798 }
1799 
nfs4_state_start_reclaim_reboot(struct nfs_client * clp)1800 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1801 {
1802 	set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1803 	/* Mark all delegations for reclaim */
1804 	nfs_delegation_mark_reclaim(clp);
1805 	nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1806 }
1807 
nfs4_reclaim_complete(struct nfs_client * clp,const struct nfs4_state_recovery_ops * ops,const struct cred * cred)1808 static int nfs4_reclaim_complete(struct nfs_client *clp,
1809 				 const struct nfs4_state_recovery_ops *ops,
1810 				 const struct cred *cred)
1811 {
1812 	/* Notify the server we're done reclaiming our state */
1813 	if (ops->reclaim_complete)
1814 		return ops->reclaim_complete(clp, cred);
1815 	return 0;
1816 }
1817 
nfs4_clear_reclaim_server(struct nfs_server * server)1818 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1819 {
1820 	struct nfs_client *clp = server->nfs_client;
1821 	struct nfs4_state_owner *sp;
1822 	struct rb_node *pos;
1823 	struct nfs4_state *state;
1824 
1825 	spin_lock(&clp->cl_lock);
1826 	for (pos = rb_first(&server->state_owners);
1827 	     pos != NULL;
1828 	     pos = rb_next(pos)) {
1829 		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1830 		spin_lock(&sp->so_lock);
1831 		list_for_each_entry(state, &sp->so_states, open_states) {
1832 			if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1833 						&state->flags))
1834 				continue;
1835 			nfs4_state_mark_reclaim_nograce(clp, state);
1836 		}
1837 		spin_unlock(&sp->so_lock);
1838 	}
1839 	spin_unlock(&clp->cl_lock);
1840 }
1841 
nfs4_state_clear_reclaim_reboot(struct nfs_client * clp)1842 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1843 {
1844 	struct nfs_server *server;
1845 
1846 	if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1847 		return 0;
1848 
1849 	rcu_read_lock();
1850 	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1851 		nfs4_clear_reclaim_server(server);
1852 	rcu_read_unlock();
1853 
1854 	nfs_delegation_reap_unclaimed(clp);
1855 	return 1;
1856 }
1857 
nfs4_state_end_reclaim_reboot(struct nfs_client * clp)1858 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1859 {
1860 	const struct nfs4_state_recovery_ops *ops;
1861 	const struct cred *cred;
1862 	int err;
1863 
1864 	if (!nfs4_state_clear_reclaim_reboot(clp))
1865 		return;
1866 	ops = clp->cl_mvops->reboot_recovery_ops;
1867 	cred = nfs4_get_clid_cred(clp);
1868 	err = nfs4_reclaim_complete(clp, ops, cred);
1869 	put_cred(cred);
1870 	if (err == -NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
1871 		set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1872 }
1873 
nfs4_state_start_reclaim_nograce(struct nfs_client * clp)1874 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1875 {
1876 	nfs_mark_test_expired_all_delegations(clp);
1877 	nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1878 }
1879 
nfs4_recovery_handle_error(struct nfs_client * clp,int error)1880 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1881 {
1882 	switch (error) {
1883 	case 0:
1884 		break;
1885 	case -NFS4ERR_CB_PATH_DOWN:
1886 		nfs40_handle_cb_pathdown(clp);
1887 		break;
1888 	case -NFS4ERR_NO_GRACE:
1889 		nfs4_state_end_reclaim_reboot(clp);
1890 		break;
1891 	case -NFS4ERR_STALE_CLIENTID:
1892 		set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1893 		nfs4_state_start_reclaim_reboot(clp);
1894 		break;
1895 	case -NFS4ERR_EXPIRED:
1896 		set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1897 		nfs4_state_start_reclaim_nograce(clp);
1898 		break;
1899 	case -NFS4ERR_BADSESSION:
1900 	case -NFS4ERR_BADSLOT:
1901 	case -NFS4ERR_BAD_HIGH_SLOT:
1902 	case -NFS4ERR_DEADSESSION:
1903 	case -NFS4ERR_SEQ_FALSE_RETRY:
1904 	case -NFS4ERR_SEQ_MISORDERED:
1905 		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1906 		/* Zero session reset errors */
1907 		break;
1908 	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1909 		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1910 		break;
1911 	default:
1912 		dprintk("%s: failed to handle error %d for server %s\n",
1913 				__func__, error, clp->cl_hostname);
1914 		return error;
1915 	}
1916 	dprintk("%s: handled error %d for server %s\n", __func__, error,
1917 			clp->cl_hostname);
1918 	return 0;
1919 }
1920 
nfs4_do_reclaim(struct nfs_client * clp,const struct nfs4_state_recovery_ops * ops)1921 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1922 {
1923 	struct nfs4_state_owner *sp;
1924 	struct nfs_server *server;
1925 	struct rb_node *pos;
1926 	LIST_HEAD(freeme);
1927 	int status = 0;
1928 
1929 restart:
1930 	rcu_read_lock();
1931 	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1932 		nfs4_purge_state_owners(server, &freeme);
1933 		spin_lock(&clp->cl_lock);
1934 		for (pos = rb_first(&server->state_owners);
1935 		     pos != NULL;
1936 		     pos = rb_next(pos)) {
1937 			sp = rb_entry(pos,
1938 				struct nfs4_state_owner, so_server_node);
1939 			if (!test_and_clear_bit(ops->owner_flag_bit,
1940 							&sp->so_flags))
1941 				continue;
1942 			if (!atomic_inc_not_zero(&sp->so_count))
1943 				continue;
1944 			spin_unlock(&clp->cl_lock);
1945 			rcu_read_unlock();
1946 
1947 			status = nfs4_reclaim_open_state(sp, ops);
1948 			if (status < 0) {
1949 				set_bit(ops->owner_flag_bit, &sp->so_flags);
1950 				nfs4_put_state_owner(sp);
1951 				status = nfs4_recovery_handle_error(clp, status);
1952 				return (status != 0) ? status : -EAGAIN;
1953 			}
1954 
1955 			nfs4_put_state_owner(sp);
1956 			goto restart;
1957 		}
1958 		spin_unlock(&clp->cl_lock);
1959 	}
1960 	rcu_read_unlock();
1961 	nfs4_free_state_owners(&freeme);
1962 	return 0;
1963 }
1964 
nfs4_check_lease(struct nfs_client * clp)1965 static int nfs4_check_lease(struct nfs_client *clp)
1966 {
1967 	const struct cred *cred;
1968 	const struct nfs4_state_maintenance_ops *ops =
1969 		clp->cl_mvops->state_renewal_ops;
1970 	int status;
1971 
1972 	/* Is the client already known to have an expired lease? */
1973 	if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1974 		return 0;
1975 	cred = ops->get_state_renewal_cred(clp);
1976 	if (cred == NULL) {
1977 		cred = nfs4_get_clid_cred(clp);
1978 		status = -ENOKEY;
1979 		if (cred == NULL)
1980 			goto out;
1981 	}
1982 	status = ops->renew_lease(clp, cred);
1983 	put_cred(cred);
1984 	if (status == -ETIMEDOUT) {
1985 		set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1986 		return 0;
1987 	}
1988 out:
1989 	return nfs4_recovery_handle_error(clp, status);
1990 }
1991 
1992 /* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1993  * and for recoverable errors on EXCHANGE_ID for v4.1
1994  */
nfs4_handle_reclaim_lease_error(struct nfs_client * clp,int status)1995 static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1996 {
1997 	switch (status) {
1998 	case -NFS4ERR_SEQ_MISORDERED:
1999 		if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
2000 			return -ESERVERFAULT;
2001 		/* Lease confirmation error: retry after purging the lease */
2002 		ssleep(1);
2003 		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2004 		break;
2005 	case -NFS4ERR_STALE_CLIENTID:
2006 		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2007 		nfs4_state_start_reclaim_reboot(clp);
2008 		break;
2009 	case -NFS4ERR_CLID_INUSE:
2010 		pr_err("NFS: Server %s reports our clientid is in use\n",
2011 			clp->cl_hostname);
2012 		nfs_mark_client_ready(clp, -EPERM);
2013 		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2014 		return -EPERM;
2015 	case -EACCES:
2016 	case -NFS4ERR_DELAY:
2017 	case -EAGAIN:
2018 		ssleep(1);
2019 		break;
2020 
2021 	case -NFS4ERR_MINOR_VERS_MISMATCH:
2022 		if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
2023 			nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
2024 		dprintk("%s: exit with error %d for server %s\n",
2025 				__func__, -EPROTONOSUPPORT, clp->cl_hostname);
2026 		return -EPROTONOSUPPORT;
2027 	case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2028 				 * in nfs4_exchange_id */
2029 	default:
2030 		dprintk("%s: exit with error %d for server %s\n", __func__,
2031 				status, clp->cl_hostname);
2032 		return status;
2033 	}
2034 	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2035 	dprintk("%s: handled error %d for server %s\n", __func__, status,
2036 			clp->cl_hostname);
2037 	return 0;
2038 }
2039 
nfs4_establish_lease(struct nfs_client * clp)2040 static int nfs4_establish_lease(struct nfs_client *clp)
2041 {
2042 	const struct cred *cred;
2043 	const struct nfs4_state_recovery_ops *ops =
2044 		clp->cl_mvops->reboot_recovery_ops;
2045 	int status;
2046 
2047 	status = nfs4_begin_drain_session(clp);
2048 	if (status != 0)
2049 		return status;
2050 	cred = nfs4_get_clid_cred(clp);
2051 	if (cred == NULL)
2052 		return -ENOENT;
2053 	status = ops->establish_clid(clp, cred);
2054 	put_cred(cred);
2055 	if (status != 0)
2056 		return status;
2057 	pnfs_destroy_all_layouts(clp);
2058 	return 0;
2059 }
2060 
2061 /*
2062  * Returns zero or a negative errno.  NFS4ERR values are converted
2063  * to local errno values.
2064  */
nfs4_reclaim_lease(struct nfs_client * clp)2065 static int nfs4_reclaim_lease(struct nfs_client *clp)
2066 {
2067 	int status;
2068 
2069 	status = nfs4_establish_lease(clp);
2070 	if (status < 0)
2071 		return nfs4_handle_reclaim_lease_error(clp, status);
2072 	if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
2073 		nfs4_state_start_reclaim_nograce(clp);
2074 	if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
2075 		set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
2076 	clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2077 	clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2078 	return 0;
2079 }
2080 
nfs4_purge_lease(struct nfs_client * clp)2081 static int nfs4_purge_lease(struct nfs_client *clp)
2082 {
2083 	int status;
2084 
2085 	status = nfs4_establish_lease(clp);
2086 	if (status < 0)
2087 		return nfs4_handle_reclaim_lease_error(clp, status);
2088 	clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2089 	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2090 	nfs4_state_start_reclaim_nograce(clp);
2091 	return 0;
2092 }
2093 
2094 /*
2095  * Try remote migration of one FSID from a source server to a
2096  * destination server.  The source server provides a list of
2097  * potential destinations.
2098  *
2099  * Returns zero or a negative NFS4ERR status code.
2100  */
nfs4_try_migration(struct nfs_server * server,const struct cred * cred)2101 static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred)
2102 {
2103 	struct nfs_client *clp = server->nfs_client;
2104 	struct nfs4_fs_locations *locations = NULL;
2105 	struct inode *inode;
2106 	struct page *page;
2107 	int status, result;
2108 
2109 	dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
2110 			(unsigned long long)server->fsid.major,
2111 			(unsigned long long)server->fsid.minor,
2112 			clp->cl_hostname);
2113 
2114 	result = 0;
2115 	page = alloc_page(GFP_KERNEL);
2116 	locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
2117 	if (page == NULL || locations == NULL) {
2118 		dprintk("<-- %s: no memory\n", __func__);
2119 		goto out;
2120 	}
2121 	locations->fattr = nfs_alloc_fattr();
2122 	if (locations->fattr == NULL) {
2123 		dprintk("<-- %s: no memory\n", __func__);
2124 		goto out;
2125 	}
2126 
2127 	inode = d_inode(server->super->s_root);
2128 	result = nfs4_proc_get_locations(server, NFS_FH(inode), locations,
2129 					 page, cred);
2130 	if (result) {
2131 		dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
2132 			__func__, result);
2133 		goto out;
2134 	}
2135 
2136 	result = -NFS4ERR_NXIO;
2137 	if (!locations->nlocations)
2138 		goto out;
2139 
2140 	if (!(locations->fattr->valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
2141 		dprintk("<-- %s: No fs_locations data, migration skipped\n",
2142 			__func__);
2143 		goto out;
2144 	}
2145 
2146 	status = nfs4_begin_drain_session(clp);
2147 	if (status != 0) {
2148 		result = status;
2149 		goto out;
2150 	}
2151 
2152 	status = nfs4_replace_transport(server, locations);
2153 	if (status != 0) {
2154 		dprintk("<-- %s: failed to replace transport: %d\n",
2155 			__func__, status);
2156 		goto out;
2157 	}
2158 
2159 	result = 0;
2160 	dprintk("<-- %s: migration succeeded\n", __func__);
2161 
2162 out:
2163 	if (page != NULL)
2164 		__free_page(page);
2165 	if (locations != NULL)
2166 		kfree(locations->fattr);
2167 	kfree(locations);
2168 	if (result) {
2169 		pr_err("NFS: migration recovery failed (server %s)\n",
2170 				clp->cl_hostname);
2171 		set_bit(NFS_MIG_FAILED, &server->mig_status);
2172 	}
2173 	return result;
2174 }
2175 
2176 /*
2177  * Returns zero or a negative NFS4ERR status code.
2178  */
nfs4_handle_migration(struct nfs_client * clp)2179 static int nfs4_handle_migration(struct nfs_client *clp)
2180 {
2181 	const struct nfs4_state_maintenance_ops *ops =
2182 				clp->cl_mvops->state_renewal_ops;
2183 	struct nfs_server *server;
2184 	const struct cred *cred;
2185 
2186 	dprintk("%s: migration reported on \"%s\"\n", __func__,
2187 			clp->cl_hostname);
2188 
2189 	cred = ops->get_state_renewal_cred(clp);
2190 	if (cred == NULL)
2191 		return -NFS4ERR_NOENT;
2192 
2193 	clp->cl_mig_gen++;
2194 restart:
2195 	rcu_read_lock();
2196 	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2197 		int status;
2198 
2199 		if (server->mig_gen == clp->cl_mig_gen)
2200 			continue;
2201 		server->mig_gen = clp->cl_mig_gen;
2202 
2203 		if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
2204 						&server->mig_status))
2205 			continue;
2206 
2207 		rcu_read_unlock();
2208 		status = nfs4_try_migration(server, cred);
2209 		if (status < 0) {
2210 			put_cred(cred);
2211 			return status;
2212 		}
2213 		goto restart;
2214 	}
2215 	rcu_read_unlock();
2216 	put_cred(cred);
2217 	return 0;
2218 }
2219 
2220 /*
2221  * Test each nfs_server on the clp's cl_superblocks list to see
2222  * if it's moved to another server.  Stop when the server no longer
2223  * returns NFS4ERR_LEASE_MOVED.
2224  */
nfs4_handle_lease_moved(struct nfs_client * clp)2225 static int nfs4_handle_lease_moved(struct nfs_client *clp)
2226 {
2227 	const struct nfs4_state_maintenance_ops *ops =
2228 				clp->cl_mvops->state_renewal_ops;
2229 	struct nfs_server *server;
2230 	const struct cred *cred;
2231 
2232 	dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2233 			clp->cl_hostname);
2234 
2235 	cred = ops->get_state_renewal_cred(clp);
2236 	if (cred == NULL)
2237 		return -NFS4ERR_NOENT;
2238 
2239 	clp->cl_mig_gen++;
2240 restart:
2241 	rcu_read_lock();
2242 	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2243 		struct inode *inode;
2244 		int status;
2245 
2246 		if (server->mig_gen == clp->cl_mig_gen)
2247 			continue;
2248 		server->mig_gen = clp->cl_mig_gen;
2249 
2250 		rcu_read_unlock();
2251 
2252 		inode = d_inode(server->super->s_root);
2253 		status = nfs4_proc_fsid_present(inode, cred);
2254 		if (status != -NFS4ERR_MOVED)
2255 			goto restart;	/* wasn't this one */
2256 		if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2257 			goto restart;	/* there are more */
2258 		goto out;
2259 	}
2260 	rcu_read_unlock();
2261 
2262 out:
2263 	put_cred(cred);
2264 	return 0;
2265 }
2266 
2267 /**
2268  * nfs4_discover_server_trunking - Detect server IP address trunking
2269  *
2270  * @clp: nfs_client under test
2271  * @result: OUT: found nfs_client, or clp
2272  *
2273  * Returns zero or a negative errno.  If zero is returned,
2274  * an nfs_client pointer is planted in "result".
2275  *
2276  * Note: since we are invoked in process context, and
2277  * not from inside the state manager, we cannot use
2278  * nfs4_handle_reclaim_lease_error().
2279  */
nfs4_discover_server_trunking(struct nfs_client * clp,struct nfs_client ** result)2280 int nfs4_discover_server_trunking(struct nfs_client *clp,
2281 				  struct nfs_client **result)
2282 {
2283 	const struct nfs4_state_recovery_ops *ops =
2284 				clp->cl_mvops->reboot_recovery_ops;
2285 	struct rpc_clnt *clnt;
2286 	const struct cred *cred;
2287 	int i, status;
2288 
2289 	dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2290 
2291 	clnt = clp->cl_rpcclient;
2292 	i = 0;
2293 
2294 	mutex_lock(&nfs_clid_init_mutex);
2295 again:
2296 	status  = -ENOENT;
2297 	cred = nfs4_get_clid_cred(clp);
2298 	if (cred == NULL)
2299 		goto out_unlock;
2300 
2301 	status = ops->detect_trunking(clp, result, cred);
2302 	put_cred(cred);
2303 	switch (status) {
2304 	case 0:
2305 	case -EINTR:
2306 	case -ERESTARTSYS:
2307 		break;
2308 	case -ETIMEDOUT:
2309 		if (clnt->cl_softrtry)
2310 			break;
2311 		fallthrough;
2312 	case -NFS4ERR_DELAY:
2313 	case -EAGAIN:
2314 		ssleep(1);
2315 		fallthrough;
2316 	case -NFS4ERR_STALE_CLIENTID:
2317 		dprintk("NFS: %s after status %d, retrying\n",
2318 			__func__, status);
2319 		goto again;
2320 	case -EACCES:
2321 		if (i++ == 0) {
2322 			nfs4_root_machine_cred(clp);
2323 			goto again;
2324 		}
2325 		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2326 			break;
2327 		fallthrough;
2328 	case -NFS4ERR_CLID_INUSE:
2329 	case -NFS4ERR_WRONGSEC:
2330 		/* No point in retrying if we already used RPC_AUTH_UNIX */
2331 		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2332 			status = -EPERM;
2333 			break;
2334 		}
2335 		clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2336 		if (IS_ERR(clnt)) {
2337 			status = PTR_ERR(clnt);
2338 			break;
2339 		}
2340 		/* Note: this is safe because we haven't yet marked the
2341 		 * client as ready, so we are the only user of
2342 		 * clp->cl_rpcclient
2343 		 */
2344 		clnt = xchg(&clp->cl_rpcclient, clnt);
2345 		rpc_shutdown_client(clnt);
2346 		clnt = clp->cl_rpcclient;
2347 		goto again;
2348 
2349 	case -NFS4ERR_MINOR_VERS_MISMATCH:
2350 		status = -EPROTONOSUPPORT;
2351 		break;
2352 
2353 	case -EKEYEXPIRED:
2354 	case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2355 				 * in nfs4_exchange_id */
2356 		status = -EKEYEXPIRED;
2357 		break;
2358 	default:
2359 		pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2360 				__func__, status);
2361 		status = -EIO;
2362 	}
2363 
2364 out_unlock:
2365 	mutex_unlock(&nfs_clid_init_mutex);
2366 	dprintk("NFS: %s: status = %d\n", __func__, status);
2367 	return status;
2368 }
2369 
2370 #ifdef CONFIG_NFS_V4_1
nfs4_schedule_session_recovery(struct nfs4_session * session,int err)2371 void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2372 {
2373 	struct nfs_client *clp = session->clp;
2374 
2375 	switch (err) {
2376 	default:
2377 		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2378 		break;
2379 	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2380 		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2381 	}
2382 	nfs4_schedule_state_manager(clp);
2383 }
2384 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2385 
nfs41_notify_server(struct nfs_client * clp)2386 void nfs41_notify_server(struct nfs_client *clp)
2387 {
2388 	/* Use CHECK_LEASE to ping the server with a SEQUENCE */
2389 	set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2390 	nfs4_schedule_state_manager(clp);
2391 }
2392 
nfs4_reset_all_state(struct nfs_client * clp)2393 static void nfs4_reset_all_state(struct nfs_client *clp)
2394 {
2395 	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2396 		set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2397 		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2398 		nfs4_state_start_reclaim_nograce(clp);
2399 		dprintk("%s: scheduling reset of all state for server %s!\n",
2400 				__func__, clp->cl_hostname);
2401 		nfs4_schedule_state_manager(clp);
2402 	}
2403 }
2404 
nfs41_handle_server_reboot(struct nfs_client * clp)2405 static void nfs41_handle_server_reboot(struct nfs_client *clp)
2406 {
2407 	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2408 		nfs4_state_start_reclaim_reboot(clp);
2409 		dprintk("%s: server %s rebooted!\n", __func__,
2410 				clp->cl_hostname);
2411 		nfs4_schedule_state_manager(clp);
2412 	}
2413 }
2414 
nfs41_handle_all_state_revoked(struct nfs_client * clp)2415 static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2416 {
2417 	nfs4_reset_all_state(clp);
2418 	dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2419 }
2420 
nfs41_handle_some_state_revoked(struct nfs_client * clp)2421 static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2422 {
2423 	nfs4_state_start_reclaim_nograce(clp);
2424 	nfs4_schedule_state_manager(clp);
2425 
2426 	dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2427 }
2428 
nfs41_handle_recallable_state_revoked(struct nfs_client * clp)2429 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2430 {
2431 	/* FIXME: For now, we destroy all layouts. */
2432 	pnfs_destroy_all_layouts(clp);
2433 	nfs_test_expired_all_delegations(clp);
2434 	dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2435 			clp->cl_hostname);
2436 }
2437 
nfs41_handle_backchannel_fault(struct nfs_client * clp)2438 static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2439 {
2440 	set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2441 	nfs4_schedule_state_manager(clp);
2442 
2443 	dprintk("%s: server %s declared a backchannel fault\n", __func__,
2444 			clp->cl_hostname);
2445 }
2446 
nfs41_handle_cb_path_down(struct nfs_client * clp)2447 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2448 {
2449 	if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2450 		&clp->cl_state) == 0)
2451 		nfs4_schedule_state_manager(clp);
2452 }
2453 
nfs41_handle_sequence_flag_errors(struct nfs_client * clp,u32 flags,bool recovery)2454 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags,
2455 		bool recovery)
2456 {
2457 	if (!flags)
2458 		return;
2459 
2460 	dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2461 		__func__, clp->cl_hostname, clp->cl_clientid, flags);
2462 	/*
2463 	 * If we're called from the state manager thread, then assume we're
2464 	 * already handling the RECLAIM_NEEDED and/or STATE_REVOKED.
2465 	 * Those flags are expected to remain set until we're done
2466 	 * recovering (see RFC5661, section 18.46.3).
2467 	 */
2468 	if (recovery)
2469 		goto out_recovery;
2470 
2471 	if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2472 		nfs41_handle_server_reboot(clp);
2473 	if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2474 		nfs41_handle_all_state_revoked(clp);
2475 	if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2476 			    SEQ4_STATUS_ADMIN_STATE_REVOKED))
2477 		nfs41_handle_some_state_revoked(clp);
2478 	if (flags & SEQ4_STATUS_LEASE_MOVED)
2479 		nfs4_schedule_lease_moved_recovery(clp);
2480 	if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2481 		nfs41_handle_recallable_state_revoked(clp);
2482 out_recovery:
2483 	if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2484 		nfs41_handle_backchannel_fault(clp);
2485 	else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2486 				SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2487 		nfs41_handle_cb_path_down(clp);
2488 }
2489 
nfs4_reset_session(struct nfs_client * clp)2490 static int nfs4_reset_session(struct nfs_client *clp)
2491 {
2492 	const struct cred *cred;
2493 	int status;
2494 
2495 	if (!nfs4_has_session(clp))
2496 		return 0;
2497 	status = nfs4_begin_drain_session(clp);
2498 	if (status != 0)
2499 		return status;
2500 	cred = nfs4_get_clid_cred(clp);
2501 	status = nfs4_proc_destroy_session(clp->cl_session, cred);
2502 	switch (status) {
2503 	case 0:
2504 	case -NFS4ERR_BADSESSION:
2505 	case -NFS4ERR_DEADSESSION:
2506 		break;
2507 	case -NFS4ERR_BACK_CHAN_BUSY:
2508 	case -NFS4ERR_DELAY:
2509 		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2510 		status = 0;
2511 		ssleep(1);
2512 		goto out;
2513 	default:
2514 		status = nfs4_recovery_handle_error(clp, status);
2515 		goto out;
2516 	}
2517 
2518 	memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2519 	status = nfs4_proc_create_session(clp, cred);
2520 	if (status) {
2521 		dprintk("%s: session reset failed with status %d for server %s!\n",
2522 			__func__, status, clp->cl_hostname);
2523 		status = nfs4_handle_reclaim_lease_error(clp, status);
2524 		goto out;
2525 	}
2526 	nfs41_finish_session_reset(clp);
2527 	dprintk("%s: session reset was successful for server %s!\n",
2528 			__func__, clp->cl_hostname);
2529 out:
2530 	put_cred(cred);
2531 	return status;
2532 }
2533 
nfs4_bind_conn_to_session(struct nfs_client * clp)2534 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2535 {
2536 	const struct cred *cred;
2537 	int ret;
2538 
2539 	if (!nfs4_has_session(clp))
2540 		return 0;
2541 	ret = nfs4_begin_drain_session(clp);
2542 	if (ret != 0)
2543 		return ret;
2544 	cred = nfs4_get_clid_cred(clp);
2545 	ret = nfs4_proc_bind_conn_to_session(clp, cred);
2546 	put_cred(cred);
2547 	clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2548 	switch (ret) {
2549 	case 0:
2550 		dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2551 			__func__, clp->cl_hostname);
2552 		break;
2553 	case -NFS4ERR_DELAY:
2554 		ssleep(1);
2555 		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2556 		break;
2557 	default:
2558 		return nfs4_recovery_handle_error(clp, ret);
2559 	}
2560 	return 0;
2561 }
2562 
nfs4_layoutreturn_any_run(struct nfs_client * clp)2563 static void nfs4_layoutreturn_any_run(struct nfs_client *clp)
2564 {
2565 	int iomode = 0;
2566 
2567 	if (test_and_clear_bit(NFS4CLNT_RECALL_ANY_LAYOUT_READ, &clp->cl_state))
2568 		iomode += IOMODE_READ;
2569 	if (test_and_clear_bit(NFS4CLNT_RECALL_ANY_LAYOUT_RW, &clp->cl_state))
2570 		iomode += IOMODE_RW;
2571 	/* Note: IOMODE_READ + IOMODE_RW == IOMODE_ANY */
2572 	if (iomode) {
2573 		pnfs_layout_return_unused_byclid(clp, iomode);
2574 		set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2575 	}
2576 }
2577 #else /* CONFIG_NFS_V4_1 */
nfs4_reset_session(struct nfs_client * clp)2578 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2579 
nfs4_bind_conn_to_session(struct nfs_client * clp)2580 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2581 {
2582 	return 0;
2583 }
2584 
nfs4_layoutreturn_any_run(struct nfs_client * clp)2585 static void nfs4_layoutreturn_any_run(struct nfs_client *clp)
2586 {
2587 }
2588 #endif /* CONFIG_NFS_V4_1 */
2589 
nfs4_state_manager(struct nfs_client * clp)2590 static void nfs4_state_manager(struct nfs_client *clp)
2591 {
2592 	unsigned int memflags;
2593 	int status = 0;
2594 	const char *section = "", *section_sep = "";
2595 
2596 	/*
2597 	 * State recovery can deadlock if the direct reclaim code tries
2598 	 * start NFS writeback. So ensure memory allocations are all
2599 	 * GFP_NOFS.
2600 	 */
2601 	memflags = memalloc_nofs_save();
2602 
2603 	/* Ensure exclusive access to NFSv4 state */
2604 	do {
2605 		trace_nfs4_state_mgr(clp);
2606 		clear_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2607 		if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2608 			section = "purge state";
2609 			status = nfs4_purge_lease(clp);
2610 			if (status < 0)
2611 				goto out_error;
2612 			continue;
2613 		}
2614 
2615 		if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2616 			section = "lease expired";
2617 			/* We're going to have to re-establish a clientid */
2618 			status = nfs4_reclaim_lease(clp);
2619 			if (status < 0)
2620 				goto out_error;
2621 			continue;
2622 		}
2623 
2624 		/* Initialize or reset the session */
2625 		if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2626 			section = "reset session";
2627 			status = nfs4_reset_session(clp);
2628 			if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2629 				continue;
2630 			if (status < 0)
2631 				goto out_error;
2632 		}
2633 
2634 		/* Send BIND_CONN_TO_SESSION */
2635 		if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2636 				&clp->cl_state)) {
2637 			section = "bind conn to session";
2638 			status = nfs4_bind_conn_to_session(clp);
2639 			if (status < 0)
2640 				goto out_error;
2641 			continue;
2642 		}
2643 
2644 		if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2645 			section = "check lease";
2646 			status = nfs4_check_lease(clp);
2647 			if (status < 0)
2648 				goto out_error;
2649 			continue;
2650 		}
2651 
2652 		if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2653 			section = "migration";
2654 			status = nfs4_handle_migration(clp);
2655 			if (status < 0)
2656 				goto out_error;
2657 		}
2658 
2659 		if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2660 			section = "lease moved";
2661 			status = nfs4_handle_lease_moved(clp);
2662 			if (status < 0)
2663 				goto out_error;
2664 		}
2665 
2666 		/* First recover reboot state... */
2667 		if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2668 			section = "reclaim reboot";
2669 			status = nfs4_do_reclaim(clp,
2670 				clp->cl_mvops->reboot_recovery_ops);
2671 			if (status == -EAGAIN)
2672 				continue;
2673 			if (status < 0)
2674 				goto out_error;
2675 			nfs4_state_end_reclaim_reboot(clp);
2676 			continue;
2677 		}
2678 
2679 		/* Detect expired delegations... */
2680 		if (test_and_clear_bit(NFS4CLNT_DELEGATION_EXPIRED, &clp->cl_state)) {
2681 			section = "detect expired delegations";
2682 			nfs_reap_expired_delegations(clp);
2683 			continue;
2684 		}
2685 
2686 		/* Now recover expired state... */
2687 		if (test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2688 			section = "reclaim nograce";
2689 			status = nfs4_do_reclaim(clp,
2690 				clp->cl_mvops->nograce_recovery_ops);
2691 			if (status == -EAGAIN)
2692 				continue;
2693 			if (status < 0)
2694 				goto out_error;
2695 			clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
2696 		}
2697 
2698 		memalloc_nofs_restore(memflags);
2699 		nfs4_end_drain_session(clp);
2700 		nfs4_clear_state_manager_bit(clp);
2701 
2702 		if (test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state) &&
2703 		    !test_and_set_bit(NFS4CLNT_MANAGER_RUNNING,
2704 				      &clp->cl_state)) {
2705 			memflags = memalloc_nofs_save();
2706 			continue;
2707 		}
2708 
2709 		if (!test_and_set_bit(NFS4CLNT_RECALL_RUNNING, &clp->cl_state)) {
2710 			if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2711 				nfs_client_return_marked_delegations(clp);
2712 				set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2713 			}
2714 			nfs4_layoutreturn_any_run(clp);
2715 			clear_bit(NFS4CLNT_RECALL_RUNNING, &clp->cl_state);
2716 		}
2717 
2718 		return;
2719 
2720 	} while (refcount_read(&clp->cl_count) > 1 && !signalled());
2721 	goto out_drain;
2722 
2723 out_error:
2724 	if (strlen(section))
2725 		section_sep = ": ";
2726 	trace_nfs4_state_mgr_failed(clp, section, status);
2727 	pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2728 			" with error %d\n", section_sep, section,
2729 			clp->cl_hostname, -status);
2730 	ssleep(1);
2731 out_drain:
2732 	memalloc_nofs_restore(memflags);
2733 	nfs4_end_drain_session(clp);
2734 	nfs4_clear_state_manager_bit(clp);
2735 }
2736 
nfs4_run_state_manager(void * ptr)2737 static int nfs4_run_state_manager(void *ptr)
2738 {
2739 	struct nfs_client *clp = ptr;
2740 	struct rpc_clnt *cl = clp->cl_rpcclient;
2741 
2742 	while (cl != cl->cl_parent)
2743 		cl = cl->cl_parent;
2744 
2745 	allow_signal(SIGKILL);
2746 again:
2747 	nfs4_state_manager(clp);
2748 
2749 	if (test_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state) &&
2750 	    !test_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state)) {
2751 		wait_var_event_interruptible(&clp->cl_state,
2752 					     test_bit(NFS4CLNT_RUN_MANAGER,
2753 						      &clp->cl_state));
2754 		if (!atomic_read(&cl->cl_swapper))
2755 			clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
2756 		if (refcount_read(&clp->cl_count) > 1 && !signalled() &&
2757 		    !test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state))
2758 			goto again;
2759 		/* Either no longer a swapper, or were signalled */
2760 		clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
2761 	}
2762 
2763 	if (refcount_read(&clp->cl_count) > 1 && !signalled() &&
2764 	    test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state) &&
2765 	    !test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state))
2766 		goto again;
2767 
2768 	nfs_put_client(clp);
2769 	module_put_and_exit(0);
2770 	return 0;
2771 }
2772