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
53#include <linux/sunrpc/clnt.h>
54
55#include "nfs4_fs.h"
56#include "callback.h"
57#include "delegation.h"
58#include "internal.h"
59#include "nfs4idmap.h"
60#include "nfs4session.h"
61#include "pnfs.h"
62#include "netns.h"
63
64#define NFSDBG_FACILITY		NFSDBG_STATE
65
66#define OPENOWNER_POOL_SIZE	8
67
68const nfs4_stateid zero_stateid;
69static DEFINE_MUTEX(nfs_clid_init_mutex);
70
71int nfs4_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
72{
73	struct nfs4_setclientid_res clid = {
74		.clientid = clp->cl_clientid,
75		.confirm = clp->cl_confirm,
76	};
77	unsigned short port;
78	int status;
79	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
80
81	if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
82		goto do_confirm;
83	port = nn->nfs_callback_tcpport;
84	if (clp->cl_addr.ss_family == AF_INET6)
85		port = nn->nfs_callback_tcpport6;
86
87	status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
88	if (status != 0)
89		goto out;
90	clp->cl_clientid = clid.clientid;
91	clp->cl_confirm = clid.confirm;
92	set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
93do_confirm:
94	status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
95	if (status != 0)
96		goto out;
97	clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
98	nfs4_schedule_state_renewal(clp);
99out:
100	return status;
101}
102
103/**
104 * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
105 *
106 * @clp: nfs_client under test
107 * @result: OUT: found nfs_client, or clp
108 * @cred: credential to use for trunking test
109 *
110 * Returns zero, a negative errno, or a negative NFS4ERR status.
111 * If zero is returned, an nfs_client pointer is planted in
112 * "result".
113 *
114 * Note: The returned client may not yet be marked ready.
115 */
116int nfs40_discover_server_trunking(struct nfs_client *clp,
117				   struct nfs_client **result,
118				   struct rpc_cred *cred)
119{
120	struct nfs4_setclientid_res clid = {
121		.clientid = clp->cl_clientid,
122		.confirm = clp->cl_confirm,
123	};
124	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
125	unsigned short port;
126	int status;
127
128	port = nn->nfs_callback_tcpport;
129	if (clp->cl_addr.ss_family == AF_INET6)
130		port = nn->nfs_callback_tcpport6;
131
132	status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
133	if (status != 0)
134		goto out;
135	clp->cl_clientid = clid.clientid;
136	clp->cl_confirm = clid.confirm;
137
138	status = nfs40_walk_client_list(clp, result, cred);
139	if (status == 0) {
140		/* Sustain the lease, even if it's empty.  If the clientid4
141		 * goes stale it's of no use for trunking discovery. */
142		nfs4_schedule_state_renewal(*result);
143	}
144out:
145	return status;
146}
147
148struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp)
149{
150	struct rpc_cred *cred = NULL;
151
152	if (clp->cl_machine_cred != NULL)
153		cred = get_rpccred(clp->cl_machine_cred);
154	return cred;
155}
156
157static void nfs4_root_machine_cred(struct nfs_client *clp)
158{
159	struct rpc_cred *cred, *new;
160
161	new = rpc_lookup_machine_cred(NULL);
162	spin_lock(&clp->cl_lock);
163	cred = clp->cl_machine_cred;
164	clp->cl_machine_cred = new;
165	spin_unlock(&clp->cl_lock);
166	if (cred != NULL)
167		put_rpccred(cred);
168}
169
170static struct rpc_cred *
171nfs4_get_renew_cred_server_locked(struct nfs_server *server)
172{
173	struct rpc_cred *cred = NULL;
174	struct nfs4_state_owner *sp;
175	struct rb_node *pos;
176
177	for (pos = rb_first(&server->state_owners);
178	     pos != NULL;
179	     pos = rb_next(pos)) {
180		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
181		if (list_empty(&sp->so_states))
182			continue;
183		cred = get_rpccred(sp->so_cred);
184		break;
185	}
186	return cred;
187}
188
189/**
190 * nfs4_get_renew_cred_locked - Acquire credential for a renew operation
191 * @clp: client state handle
192 *
193 * Returns an rpc_cred with reference count bumped, or NULL.
194 * Caller must hold clp->cl_lock.
195 */
196struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
197{
198	struct rpc_cred *cred = NULL;
199	struct nfs_server *server;
200
201	/* Use machine credentials if available */
202	cred = nfs4_get_machine_cred_locked(clp);
203	if (cred != NULL)
204		goto out;
205
206	rcu_read_lock();
207	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
208		cred = nfs4_get_renew_cred_server_locked(server);
209		if (cred != NULL)
210			break;
211	}
212	rcu_read_unlock();
213
214out:
215	return cred;
216}
217
218static void nfs4_end_drain_slot_table(struct nfs4_slot_table *tbl)
219{
220	if (test_and_clear_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
221		spin_lock(&tbl->slot_tbl_lock);
222		nfs41_wake_slot_table(tbl);
223		spin_unlock(&tbl->slot_tbl_lock);
224	}
225}
226
227static void nfs4_end_drain_session(struct nfs_client *clp)
228{
229	struct nfs4_session *ses = clp->cl_session;
230
231	if (clp->cl_slot_tbl) {
232		nfs4_end_drain_slot_table(clp->cl_slot_tbl);
233		return;
234	}
235
236	if (ses != NULL) {
237		nfs4_end_drain_slot_table(&ses->bc_slot_table);
238		nfs4_end_drain_slot_table(&ses->fc_slot_table);
239	}
240}
241
242static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)
243{
244	set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
245	spin_lock(&tbl->slot_tbl_lock);
246	if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
247		reinit_completion(&tbl->complete);
248		spin_unlock(&tbl->slot_tbl_lock);
249		return wait_for_completion_interruptible(&tbl->complete);
250	}
251	spin_unlock(&tbl->slot_tbl_lock);
252	return 0;
253}
254
255static int nfs4_begin_drain_session(struct nfs_client *clp)
256{
257	struct nfs4_session *ses = clp->cl_session;
258	int ret = 0;
259
260	if (clp->cl_slot_tbl)
261		return nfs4_drain_slot_tbl(clp->cl_slot_tbl);
262
263	/* back channel */
264	ret = nfs4_drain_slot_tbl(&ses->bc_slot_table);
265	if (ret)
266		return ret;
267	/* fore channel */
268	return nfs4_drain_slot_tbl(&ses->fc_slot_table);
269}
270
271#if defined(CONFIG_NFS_V4_1)
272
273static int nfs41_setup_state_renewal(struct nfs_client *clp)
274{
275	int status;
276	struct nfs_fsinfo fsinfo;
277
278	if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
279		nfs4_schedule_state_renewal(clp);
280		return 0;
281	}
282
283	status = nfs4_proc_get_lease_time(clp, &fsinfo);
284	if (status == 0) {
285		/* Update lease time and schedule renewal */
286		spin_lock(&clp->cl_lock);
287		clp->cl_lease_time = fsinfo.lease_time * HZ;
288		clp->cl_last_renewal = jiffies;
289		spin_unlock(&clp->cl_lock);
290
291		nfs4_schedule_state_renewal(clp);
292	}
293
294	return status;
295}
296
297static void nfs41_finish_session_reset(struct nfs_client *clp)
298{
299	clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
300	clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
301	/* create_session negotiated new slot table */
302	clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
303	nfs41_setup_state_renewal(clp);
304}
305
306int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
307{
308	int status;
309
310	if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
311		goto do_confirm;
312	nfs4_begin_drain_session(clp);
313	status = nfs4_proc_exchange_id(clp, cred);
314	if (status != 0)
315		goto out;
316	set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
317do_confirm:
318	status = nfs4_proc_create_session(clp, cred);
319	if (status != 0)
320		goto out;
321	nfs41_finish_session_reset(clp);
322	nfs_mark_client_ready(clp, NFS_CS_READY);
323out:
324	return status;
325}
326
327/**
328 * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
329 *
330 * @clp: nfs_client under test
331 * @result: OUT: found nfs_client, or clp
332 * @cred: credential to use for trunking test
333 *
334 * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
335 * If NFS4_OK is returned, an nfs_client pointer is planted in
336 * "result".
337 *
338 * Note: The returned client may not yet be marked ready.
339 */
340int nfs41_discover_server_trunking(struct nfs_client *clp,
341				   struct nfs_client **result,
342				   struct rpc_cred *cred)
343{
344	int status;
345
346	status = nfs4_proc_exchange_id(clp, cred);
347	if (status != NFS4_OK)
348		return status;
349
350	status = nfs41_walk_client_list(clp, result, cred);
351	if (status < 0)
352		return status;
353	if (clp != *result)
354		return 0;
355
356	/* Purge state if the client id was established in a prior instance */
357	if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R)
358		set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
359	else
360		set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
361	nfs4_schedule_state_manager(clp);
362	status = nfs_wait_client_init_complete(clp);
363	if (status < 0)
364		nfs_put_client(clp);
365	return status;
366}
367
368#endif /* CONFIG_NFS_V4_1 */
369
370/**
371 * nfs4_get_clid_cred - Acquire credential for a setclientid operation
372 * @clp: client state handle
373 *
374 * Returns an rpc_cred with reference count bumped, or NULL.
375 */
376struct rpc_cred *nfs4_get_clid_cred(struct nfs_client *clp)
377{
378	struct rpc_cred *cred;
379
380	spin_lock(&clp->cl_lock);
381	cred = nfs4_get_machine_cred_locked(clp);
382	spin_unlock(&clp->cl_lock);
383	return cred;
384}
385
386static struct nfs4_state_owner *
387nfs4_find_state_owner_locked(struct nfs_server *server, struct rpc_cred *cred)
388{
389	struct rb_node **p = &server->state_owners.rb_node,
390		       *parent = NULL;
391	struct nfs4_state_owner *sp;
392
393	while (*p != NULL) {
394		parent = *p;
395		sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
396
397		if (cred < sp->so_cred)
398			p = &parent->rb_left;
399		else if (cred > sp->so_cred)
400			p = &parent->rb_right;
401		else {
402			if (!list_empty(&sp->so_lru))
403				list_del_init(&sp->so_lru);
404			atomic_inc(&sp->so_count);
405			return sp;
406		}
407	}
408	return NULL;
409}
410
411static struct nfs4_state_owner *
412nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
413{
414	struct nfs_server *server = new->so_server;
415	struct rb_node **p = &server->state_owners.rb_node,
416		       *parent = NULL;
417	struct nfs4_state_owner *sp;
418	int err;
419
420	while (*p != NULL) {
421		parent = *p;
422		sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
423
424		if (new->so_cred < sp->so_cred)
425			p = &parent->rb_left;
426		else if (new->so_cred > sp->so_cred)
427			p = &parent->rb_right;
428		else {
429			if (!list_empty(&sp->so_lru))
430				list_del_init(&sp->so_lru);
431			atomic_inc(&sp->so_count);
432			return sp;
433		}
434	}
435	err = ida_get_new(&server->openowner_id, &new->so_seqid.owner_id);
436	if (err)
437		return ERR_PTR(err);
438	rb_link_node(&new->so_server_node, parent, p);
439	rb_insert_color(&new->so_server_node, &server->state_owners);
440	return new;
441}
442
443static void
444nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
445{
446	struct nfs_server *server = sp->so_server;
447
448	if (!RB_EMPTY_NODE(&sp->so_server_node))
449		rb_erase(&sp->so_server_node, &server->state_owners);
450	ida_remove(&server->openowner_id, sp->so_seqid.owner_id);
451}
452
453static void
454nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
455{
456	sc->create_time = ktime_get();
457	sc->flags = 0;
458	sc->counter = 0;
459	spin_lock_init(&sc->lock);
460	INIT_LIST_HEAD(&sc->list);
461	rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
462}
463
464static void
465nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
466{
467	rpc_destroy_wait_queue(&sc->wait);
468}
469
470/*
471 * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
472 * create a new state_owner.
473 *
474 */
475static struct nfs4_state_owner *
476nfs4_alloc_state_owner(struct nfs_server *server,
477		struct rpc_cred *cred,
478		gfp_t gfp_flags)
479{
480	struct nfs4_state_owner *sp;
481
482	sp = kzalloc(sizeof(*sp), gfp_flags);
483	if (!sp)
484		return NULL;
485	sp->so_server = server;
486	sp->so_cred = get_rpccred(cred);
487	spin_lock_init(&sp->so_lock);
488	INIT_LIST_HEAD(&sp->so_states);
489	nfs4_init_seqid_counter(&sp->so_seqid);
490	atomic_set(&sp->so_count, 1);
491	INIT_LIST_HEAD(&sp->so_lru);
492	seqcount_init(&sp->so_reclaim_seqcount);
493	mutex_init(&sp->so_delegreturn_mutex);
494	return sp;
495}
496
497static void
498nfs4_drop_state_owner(struct nfs4_state_owner *sp)
499{
500	struct rb_node *rb_node = &sp->so_server_node;
501
502	if (!RB_EMPTY_NODE(rb_node)) {
503		struct nfs_server *server = sp->so_server;
504		struct nfs_client *clp = server->nfs_client;
505
506		spin_lock(&clp->cl_lock);
507		if (!RB_EMPTY_NODE(rb_node)) {
508			rb_erase(rb_node, &server->state_owners);
509			RB_CLEAR_NODE(rb_node);
510		}
511		spin_unlock(&clp->cl_lock);
512	}
513}
514
515static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
516{
517	nfs4_destroy_seqid_counter(&sp->so_seqid);
518	put_rpccred(sp->so_cred);
519	kfree(sp);
520}
521
522static void nfs4_gc_state_owners(struct nfs_server *server)
523{
524	struct nfs_client *clp = server->nfs_client;
525	struct nfs4_state_owner *sp, *tmp;
526	unsigned long time_min, time_max;
527	LIST_HEAD(doomed);
528
529	spin_lock(&clp->cl_lock);
530	time_max = jiffies;
531	time_min = (long)time_max - (long)clp->cl_lease_time;
532	list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
533		/* NB: LRU is sorted so that oldest is at the head */
534		if (time_in_range(sp->so_expires, time_min, time_max))
535			break;
536		list_move(&sp->so_lru, &doomed);
537		nfs4_remove_state_owner_locked(sp);
538	}
539	spin_unlock(&clp->cl_lock);
540
541	list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
542		list_del(&sp->so_lru);
543		nfs4_free_state_owner(sp);
544	}
545}
546
547/**
548 * nfs4_get_state_owner - Look up a state owner given a credential
549 * @server: nfs_server to search
550 * @cred: RPC credential to match
551 *
552 * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
553 */
554struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
555					      struct rpc_cred *cred,
556					      gfp_t gfp_flags)
557{
558	struct nfs_client *clp = server->nfs_client;
559	struct nfs4_state_owner *sp, *new;
560
561	spin_lock(&clp->cl_lock);
562	sp = nfs4_find_state_owner_locked(server, cred);
563	spin_unlock(&clp->cl_lock);
564	if (sp != NULL)
565		goto out;
566	new = nfs4_alloc_state_owner(server, cred, gfp_flags);
567	if (new == NULL)
568		goto out;
569	do {
570		if (ida_pre_get(&server->openowner_id, gfp_flags) == 0)
571			break;
572		spin_lock(&clp->cl_lock);
573		sp = nfs4_insert_state_owner_locked(new);
574		spin_unlock(&clp->cl_lock);
575	} while (sp == ERR_PTR(-EAGAIN));
576	if (sp != new)
577		nfs4_free_state_owner(new);
578out:
579	nfs4_gc_state_owners(server);
580	return sp;
581}
582
583/**
584 * nfs4_put_state_owner - Release a nfs4_state_owner
585 * @sp: state owner data to release
586 *
587 * Note that we keep released state owners on an LRU
588 * list.
589 * This caches valid state owners so that they can be
590 * reused, to avoid the OPEN_CONFIRM on minor version 0.
591 * It also pins the uniquifier of dropped state owners for
592 * a while, to ensure that those state owner names are
593 * never reused.
594 */
595void nfs4_put_state_owner(struct nfs4_state_owner *sp)
596{
597	struct nfs_server *server = sp->so_server;
598	struct nfs_client *clp = server->nfs_client;
599
600	if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
601		return;
602
603	sp->so_expires = jiffies;
604	list_add_tail(&sp->so_lru, &server->state_owners_lru);
605	spin_unlock(&clp->cl_lock);
606}
607
608/**
609 * nfs4_purge_state_owners - Release all cached state owners
610 * @server: nfs_server with cached state owners to release
611 *
612 * Called at umount time.  Remaining state owners will be on
613 * the LRU with ref count of zero.
614 */
615void nfs4_purge_state_owners(struct nfs_server *server)
616{
617	struct nfs_client *clp = server->nfs_client;
618	struct nfs4_state_owner *sp, *tmp;
619	LIST_HEAD(doomed);
620
621	spin_lock(&clp->cl_lock);
622	list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
623		list_move(&sp->so_lru, &doomed);
624		nfs4_remove_state_owner_locked(sp);
625	}
626	spin_unlock(&clp->cl_lock);
627
628	list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
629		list_del(&sp->so_lru);
630		nfs4_free_state_owner(sp);
631	}
632}
633
634static struct nfs4_state *
635nfs4_alloc_open_state(void)
636{
637	struct nfs4_state *state;
638
639	state = kzalloc(sizeof(*state), GFP_NOFS);
640	if (!state)
641		return NULL;
642	atomic_set(&state->count, 1);
643	INIT_LIST_HEAD(&state->lock_states);
644	spin_lock_init(&state->state_lock);
645	seqlock_init(&state->seqlock);
646	return state;
647}
648
649void
650nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
651{
652	if (state->state == fmode)
653		return;
654	/* NB! List reordering - see the reclaim code for why.  */
655	if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
656		if (fmode & FMODE_WRITE)
657			list_move(&state->open_states, &state->owner->so_states);
658		else
659			list_move_tail(&state->open_states, &state->owner->so_states);
660	}
661	state->state = fmode;
662}
663
664static struct nfs4_state *
665__nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
666{
667	struct nfs_inode *nfsi = NFS_I(inode);
668	struct nfs4_state *state;
669
670	list_for_each_entry(state, &nfsi->open_states, inode_states) {
671		if (state->owner != owner)
672			continue;
673		if (!nfs4_valid_open_stateid(state))
674			continue;
675		if (atomic_inc_not_zero(&state->count))
676			return state;
677	}
678	return NULL;
679}
680
681static void
682nfs4_free_open_state(struct nfs4_state *state)
683{
684	kfree(state);
685}
686
687struct nfs4_state *
688nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
689{
690	struct nfs4_state *state, *new;
691	struct nfs_inode *nfsi = NFS_I(inode);
692
693	spin_lock(&inode->i_lock);
694	state = __nfs4_find_state_byowner(inode, owner);
695	spin_unlock(&inode->i_lock);
696	if (state)
697		goto out;
698	new = nfs4_alloc_open_state();
699	spin_lock(&owner->so_lock);
700	spin_lock(&inode->i_lock);
701	state = __nfs4_find_state_byowner(inode, owner);
702	if (state == NULL && new != NULL) {
703		state = new;
704		state->owner = owner;
705		atomic_inc(&owner->so_count);
706		list_add(&state->inode_states, &nfsi->open_states);
707		ihold(inode);
708		state->inode = inode;
709		spin_unlock(&inode->i_lock);
710		/* Note: The reclaim code dictates that we add stateless
711		 * and read-only stateids to the end of the list */
712		list_add_tail(&state->open_states, &owner->so_states);
713		spin_unlock(&owner->so_lock);
714	} else {
715		spin_unlock(&inode->i_lock);
716		spin_unlock(&owner->so_lock);
717		if (new)
718			nfs4_free_open_state(new);
719	}
720out:
721	return state;
722}
723
724void nfs4_put_open_state(struct nfs4_state *state)
725{
726	struct inode *inode = state->inode;
727	struct nfs4_state_owner *owner = state->owner;
728
729	if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
730		return;
731	spin_lock(&inode->i_lock);
732	list_del(&state->inode_states);
733	list_del(&state->open_states);
734	spin_unlock(&inode->i_lock);
735	spin_unlock(&owner->so_lock);
736	iput(inode);
737	nfs4_free_open_state(state);
738	nfs4_put_state_owner(owner);
739}
740
741/*
742 * Close the current file.
743 */
744static void __nfs4_close(struct nfs4_state *state,
745		fmode_t fmode, gfp_t gfp_mask, int wait)
746{
747	struct nfs4_state_owner *owner = state->owner;
748	int call_close = 0;
749	fmode_t newstate;
750
751	atomic_inc(&owner->so_count);
752	/* Protect against nfs4_find_state() */
753	spin_lock(&owner->so_lock);
754	switch (fmode & (FMODE_READ | FMODE_WRITE)) {
755		case FMODE_READ:
756			state->n_rdonly--;
757			break;
758		case FMODE_WRITE:
759			state->n_wronly--;
760			break;
761		case FMODE_READ|FMODE_WRITE:
762			state->n_rdwr--;
763	}
764	newstate = FMODE_READ|FMODE_WRITE;
765	if (state->n_rdwr == 0) {
766		if (state->n_rdonly == 0) {
767			newstate &= ~FMODE_READ;
768			call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
769			call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
770		}
771		if (state->n_wronly == 0) {
772			newstate &= ~FMODE_WRITE;
773			call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
774			call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
775		}
776		if (newstate == 0)
777			clear_bit(NFS_DELEGATED_STATE, &state->flags);
778	}
779	nfs4_state_set_mode_locked(state, newstate);
780	spin_unlock(&owner->so_lock);
781
782	if (!call_close) {
783		nfs4_put_open_state(state);
784		nfs4_put_state_owner(owner);
785	} else
786		nfs4_do_close(state, gfp_mask, wait);
787}
788
789void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
790{
791	__nfs4_close(state, fmode, GFP_NOFS, 0);
792}
793
794void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
795{
796	__nfs4_close(state, fmode, GFP_KERNEL, 1);
797}
798
799/*
800 * Search the state->lock_states for an existing lock_owner
801 * that is compatible with current->files
802 */
803static struct nfs4_lock_state *
804__nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
805{
806	struct nfs4_lock_state *pos;
807	list_for_each_entry(pos, &state->lock_states, ls_locks) {
808		if (pos->ls_owner != fl_owner)
809			continue;
810		atomic_inc(&pos->ls_count);
811		return pos;
812	}
813	return NULL;
814}
815
816/*
817 * Return a compatible lock_state. If no initialized lock_state structure
818 * exists, return an uninitialized one.
819 *
820 */
821static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
822{
823	struct nfs4_lock_state *lsp;
824	struct nfs_server *server = state->owner->so_server;
825
826	lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
827	if (lsp == NULL)
828		return NULL;
829	nfs4_init_seqid_counter(&lsp->ls_seqid);
830	atomic_set(&lsp->ls_count, 1);
831	lsp->ls_state = state;
832	lsp->ls_owner = fl_owner;
833	lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
834	if (lsp->ls_seqid.owner_id < 0)
835		goto out_free;
836	INIT_LIST_HEAD(&lsp->ls_locks);
837	return lsp;
838out_free:
839	kfree(lsp);
840	return NULL;
841}
842
843void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
844{
845	ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
846	nfs4_destroy_seqid_counter(&lsp->ls_seqid);
847	kfree(lsp);
848}
849
850/*
851 * Return a compatible lock_state. If no initialized lock_state structure
852 * exists, return an uninitialized one.
853 *
854 */
855static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
856{
857	struct nfs4_lock_state *lsp, *new = NULL;
858
859	for(;;) {
860		spin_lock(&state->state_lock);
861		lsp = __nfs4_find_lock_state(state, owner);
862		if (lsp != NULL)
863			break;
864		if (new != NULL) {
865			list_add(&new->ls_locks, &state->lock_states);
866			set_bit(LK_STATE_IN_USE, &state->flags);
867			lsp = new;
868			new = NULL;
869			break;
870		}
871		spin_unlock(&state->state_lock);
872		new = nfs4_alloc_lock_state(state, owner);
873		if (new == NULL)
874			return NULL;
875	}
876	spin_unlock(&state->state_lock);
877	if (new != NULL)
878		nfs4_free_lock_state(state->owner->so_server, new);
879	return lsp;
880}
881
882/*
883 * Release reference to lock_state, and free it if we see that
884 * it is no longer in use
885 */
886void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
887{
888	struct nfs_server *server;
889	struct nfs4_state *state;
890
891	if (lsp == NULL)
892		return;
893	state = lsp->ls_state;
894	if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
895		return;
896	list_del(&lsp->ls_locks);
897	if (list_empty(&state->lock_states))
898		clear_bit(LK_STATE_IN_USE, &state->flags);
899	spin_unlock(&state->state_lock);
900	server = state->owner->so_server;
901	if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
902		struct nfs_client *clp = server->nfs_client;
903
904		clp->cl_mvops->free_lock_state(server, lsp);
905	} else
906		nfs4_free_lock_state(server, lsp);
907}
908
909static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
910{
911	struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
912
913	dst->fl_u.nfs4_fl.owner = lsp;
914	atomic_inc(&lsp->ls_count);
915}
916
917static void nfs4_fl_release_lock(struct file_lock *fl)
918{
919	nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
920}
921
922static const struct file_lock_operations nfs4_fl_lock_ops = {
923	.fl_copy_lock = nfs4_fl_copy_lock,
924	.fl_release_private = nfs4_fl_release_lock,
925};
926
927int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
928{
929	struct nfs4_lock_state *lsp;
930
931	if (fl->fl_ops != NULL)
932		return 0;
933	lsp = nfs4_get_lock_state(state, fl->fl_owner);
934	if (lsp == NULL)
935		return -ENOMEM;
936	fl->fl_u.nfs4_fl.owner = lsp;
937	fl->fl_ops = &nfs4_fl_lock_ops;
938	return 0;
939}
940
941static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
942		struct nfs4_state *state,
943		const struct nfs_lockowner *lockowner)
944{
945	struct nfs4_lock_state *lsp;
946	fl_owner_t fl_owner;
947	int ret = -ENOENT;
948
949
950	if (lockowner == NULL)
951		goto out;
952
953	if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
954		goto out;
955
956	fl_owner = lockowner->l_owner;
957	spin_lock(&state->state_lock);
958	lsp = __nfs4_find_lock_state(state, fl_owner);
959	if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
960		ret = -EIO;
961	else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
962		nfs4_stateid_copy(dst, &lsp->ls_stateid);
963		ret = 0;
964	}
965	spin_unlock(&state->state_lock);
966	nfs4_put_lock_state(lsp);
967out:
968	return ret;
969}
970
971static void nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
972{
973	const nfs4_stateid *src;
974	int seq;
975
976	do {
977		src = &zero_stateid;
978		seq = read_seqbegin(&state->seqlock);
979		if (test_bit(NFS_OPEN_STATE, &state->flags))
980			src = &state->open_stateid;
981		nfs4_stateid_copy(dst, src);
982	} while (read_seqretry(&state->seqlock, seq));
983}
984
985/*
986 * Byte-range lock aware utility to initialize the stateid of read/write
987 * requests.
988 */
989int nfs4_select_rw_stateid(nfs4_stateid *dst, struct nfs4_state *state,
990		fmode_t fmode, const struct nfs_lockowner *lockowner)
991{
992	int ret = nfs4_copy_lock_stateid(dst, state, lockowner);
993	if (ret == -EIO)
994		/* A lost lock - don't even consider delegations */
995		goto out;
996	/* returns true if delegation stateid found and copied */
997	if (nfs4_copy_delegation_stateid(dst, state->inode, fmode)) {
998		ret = 0;
999		goto out;
1000	}
1001	if (ret != -ENOENT)
1002		/* nfs4_copy_delegation_stateid() didn't over-write
1003		 * dst, so it still has the lock stateid which we now
1004		 * choose to use.
1005		 */
1006		goto out;
1007	nfs4_copy_open_stateid(dst, state);
1008	ret = 0;
1009out:
1010	if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1011		dst->seqid = 0;
1012	return ret;
1013}
1014
1015struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1016{
1017	struct nfs_seqid *new;
1018
1019	new = kmalloc(sizeof(*new), gfp_mask);
1020	if (new == NULL)
1021		return ERR_PTR(-ENOMEM);
1022	new->sequence = counter;
1023	INIT_LIST_HEAD(&new->list);
1024	new->task = NULL;
1025	return new;
1026}
1027
1028void nfs_release_seqid(struct nfs_seqid *seqid)
1029{
1030	struct nfs_seqid_counter *sequence;
1031
1032	if (seqid == NULL || list_empty(&seqid->list))
1033		return;
1034	sequence = seqid->sequence;
1035	spin_lock(&sequence->lock);
1036	list_del_init(&seqid->list);
1037	if (!list_empty(&sequence->list)) {
1038		struct nfs_seqid *next;
1039
1040		next = list_first_entry(&sequence->list,
1041				struct nfs_seqid, list);
1042		rpc_wake_up_queued_task(&sequence->wait, next->task);
1043	}
1044	spin_unlock(&sequence->lock);
1045}
1046
1047void nfs_free_seqid(struct nfs_seqid *seqid)
1048{
1049	nfs_release_seqid(seqid);
1050	kfree(seqid);
1051}
1052
1053/*
1054 * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1055 * failed with a seqid incrementing error -
1056 * see comments nfs4.h:seqid_mutating_error()
1057 */
1058static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1059{
1060	switch (status) {
1061		case 0:
1062			break;
1063		case -NFS4ERR_BAD_SEQID:
1064			if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1065				return;
1066			pr_warn_ratelimited("NFS: v4 server returned a bad"
1067					" sequence-id error on an"
1068					" unconfirmed sequence %p!\n",
1069					seqid->sequence);
1070		case -NFS4ERR_STALE_CLIENTID:
1071		case -NFS4ERR_STALE_STATEID:
1072		case -NFS4ERR_BAD_STATEID:
1073		case -NFS4ERR_BADXDR:
1074		case -NFS4ERR_RESOURCE:
1075		case -NFS4ERR_NOFILEHANDLE:
1076			/* Non-seqid mutating errors */
1077			return;
1078	};
1079	/*
1080	 * Note: no locking needed as we are guaranteed to be first
1081	 * on the sequence list
1082	 */
1083	seqid->sequence->counter++;
1084}
1085
1086void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1087{
1088	struct nfs4_state_owner *sp;
1089
1090	if (seqid == NULL)
1091		return;
1092
1093	sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1094	if (status == -NFS4ERR_BAD_SEQID)
1095		nfs4_drop_state_owner(sp);
1096	if (!nfs4_has_session(sp->so_server->nfs_client))
1097		nfs_increment_seqid(status, seqid);
1098}
1099
1100/*
1101 * Increment the seqid if the LOCK/LOCKU succeeded, or
1102 * failed with a seqid incrementing error -
1103 * see comments nfs4.h:seqid_mutating_error()
1104 */
1105void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1106{
1107	if (seqid != NULL)
1108		nfs_increment_seqid(status, seqid);
1109}
1110
1111int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1112{
1113	struct nfs_seqid_counter *sequence;
1114	int status = 0;
1115
1116	if (seqid == NULL)
1117		goto out;
1118	sequence = seqid->sequence;
1119	spin_lock(&sequence->lock);
1120	seqid->task = task;
1121	if (list_empty(&seqid->list))
1122		list_add_tail(&seqid->list, &sequence->list);
1123	if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1124		goto unlock;
1125	rpc_sleep_on(&sequence->wait, task, NULL);
1126	status = -EAGAIN;
1127unlock:
1128	spin_unlock(&sequence->lock);
1129out:
1130	return status;
1131}
1132
1133static int nfs4_run_state_manager(void *);
1134
1135static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1136{
1137	smp_mb__before_atomic();
1138	clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1139	smp_mb__after_atomic();
1140	wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1141	rpc_wake_up(&clp->cl_rpcwaitq);
1142}
1143
1144/*
1145 * Schedule the nfs_client asynchronous state management routine
1146 */
1147void nfs4_schedule_state_manager(struct nfs_client *clp)
1148{
1149	struct task_struct *task;
1150	char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1151
1152	if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1153		return;
1154	__module_get(THIS_MODULE);
1155	atomic_inc(&clp->cl_count);
1156
1157	/* The rcu_read_lock() is not strictly necessary, as the state
1158	 * manager is the only thread that ever changes the rpc_xprt
1159	 * after it's initialized.  At this point, we're single threaded. */
1160	rcu_read_lock();
1161	snprintf(buf, sizeof(buf), "%s-manager",
1162			rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1163	rcu_read_unlock();
1164	task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1165	if (IS_ERR(task)) {
1166		printk(KERN_ERR "%s: kthread_run: %ld\n",
1167			__func__, PTR_ERR(task));
1168		nfs4_clear_state_manager_bit(clp);
1169		nfs_put_client(clp);
1170		module_put(THIS_MODULE);
1171	}
1172}
1173
1174/*
1175 * Schedule a lease recovery attempt
1176 */
1177void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1178{
1179	if (!clp)
1180		return;
1181	if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1182		set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1183	dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1184			clp->cl_hostname);
1185	nfs4_schedule_state_manager(clp);
1186}
1187EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1188
1189/**
1190 * nfs4_schedule_migration_recovery - trigger migration recovery
1191 *
1192 * @server: FSID that is migrating
1193 *
1194 * Returns zero if recovery has started, otherwise a negative NFS4ERR
1195 * value is returned.
1196 */
1197int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1198{
1199	struct nfs_client *clp = server->nfs_client;
1200
1201	if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1202		pr_err("NFS: volatile file handles not supported (server %s)\n",
1203				clp->cl_hostname);
1204		return -NFS4ERR_IO;
1205	}
1206
1207	if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1208		return -NFS4ERR_IO;
1209
1210	dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1211			__func__,
1212			(unsigned long long)server->fsid.major,
1213			(unsigned long long)server->fsid.minor,
1214			clp->cl_hostname);
1215
1216	set_bit(NFS_MIG_IN_TRANSITION,
1217			&((struct nfs_server *)server)->mig_status);
1218	set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1219
1220	nfs4_schedule_state_manager(clp);
1221	return 0;
1222}
1223EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1224
1225/**
1226 * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1227 *
1228 * @clp: server to check for moved leases
1229 *
1230 */
1231void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1232{
1233	dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1234		__func__, clp->cl_clientid, clp->cl_hostname);
1235
1236	set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1237	nfs4_schedule_state_manager(clp);
1238}
1239EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1240
1241int nfs4_wait_clnt_recover(struct nfs_client *clp)
1242{
1243	int res;
1244
1245	might_sleep();
1246
1247	atomic_inc(&clp->cl_count);
1248	res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1249				 nfs_wait_bit_killable, TASK_KILLABLE);
1250	if (res)
1251		goto out;
1252	if (clp->cl_cons_state < 0)
1253		res = clp->cl_cons_state;
1254out:
1255	nfs_put_client(clp);
1256	return res;
1257}
1258
1259int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1260{
1261	unsigned int loop;
1262	int ret;
1263
1264	for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1265		ret = nfs4_wait_clnt_recover(clp);
1266		if (ret != 0)
1267			break;
1268		if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1269		    !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1270			break;
1271		nfs4_schedule_state_manager(clp);
1272		ret = -EIO;
1273	}
1274	return ret;
1275}
1276
1277/*
1278 * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1279 * @clp: client to process
1280 *
1281 * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1282 * resend of the SETCLIENTID and hence re-establish the
1283 * callback channel. Then return all existing delegations.
1284 */
1285static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1286{
1287	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1288	nfs_expire_all_delegations(clp);
1289	dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1290			clp->cl_hostname);
1291}
1292
1293void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1294{
1295	nfs40_handle_cb_pathdown(clp);
1296	nfs4_schedule_state_manager(clp);
1297}
1298
1299static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1300{
1301
1302	set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1303	/* Don't recover state that expired before the reboot */
1304	if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1305		clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1306		return 0;
1307	}
1308	set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1309	set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1310	return 1;
1311}
1312
1313int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1314{
1315	set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1316	clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1317	set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1318	set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1319	return 1;
1320}
1321
1322int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1323{
1324	struct nfs_client *clp = server->nfs_client;
1325
1326	if (!nfs4_valid_open_stateid(state))
1327		return -EBADF;
1328	nfs4_state_mark_reclaim_nograce(clp, state);
1329	dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1330			clp->cl_hostname);
1331	nfs4_schedule_state_manager(clp);
1332	return 0;
1333}
1334EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1335
1336void nfs_inode_find_state_and_recover(struct inode *inode,
1337		const nfs4_stateid *stateid)
1338{
1339	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1340	struct nfs_inode *nfsi = NFS_I(inode);
1341	struct nfs_open_context *ctx;
1342	struct nfs4_state *state;
1343	bool found = false;
1344
1345	spin_lock(&inode->i_lock);
1346	list_for_each_entry(ctx, &nfsi->open_files, list) {
1347		state = ctx->state;
1348		if (state == NULL)
1349			continue;
1350		if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
1351			continue;
1352		if (!nfs4_stateid_match(&state->stateid, stateid))
1353			continue;
1354		nfs4_state_mark_reclaim_nograce(clp, state);
1355		found = true;
1356	}
1357	spin_unlock(&inode->i_lock);
1358	if (found)
1359		nfs4_schedule_state_manager(clp);
1360}
1361
1362static void nfs4_state_mark_open_context_bad(struct nfs4_state *state)
1363{
1364	struct inode *inode = state->inode;
1365	struct nfs_inode *nfsi = NFS_I(inode);
1366	struct nfs_open_context *ctx;
1367
1368	spin_lock(&inode->i_lock);
1369	list_for_each_entry(ctx, &nfsi->open_files, list) {
1370		if (ctx->state != state)
1371			continue;
1372		set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1373	}
1374	spin_unlock(&inode->i_lock);
1375}
1376
1377static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1378{
1379	set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1380	nfs4_state_mark_open_context_bad(state);
1381}
1382
1383
1384static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1385{
1386	struct inode *inode = state->inode;
1387	struct nfs_inode *nfsi = NFS_I(inode);
1388	struct file_lock *fl;
1389	int status = 0;
1390	struct file_lock_context *flctx = inode->i_flctx;
1391	struct list_head *list;
1392
1393	if (flctx == NULL)
1394		return 0;
1395
1396	list = &flctx->flc_posix;
1397
1398	/* Guard against delegation returns and new lock/unlock calls */
1399	down_write(&nfsi->rwsem);
1400	spin_lock(&flctx->flc_lock);
1401restart:
1402	list_for_each_entry(fl, list, fl_list) {
1403		if (nfs_file_open_context(fl->fl_file)->state != state)
1404			continue;
1405		spin_unlock(&flctx->flc_lock);
1406		status = ops->recover_lock(state, fl);
1407		switch (status) {
1408		case 0:
1409			break;
1410		case -ESTALE:
1411		case -NFS4ERR_ADMIN_REVOKED:
1412		case -NFS4ERR_STALE_STATEID:
1413		case -NFS4ERR_BAD_STATEID:
1414		case -NFS4ERR_EXPIRED:
1415		case -NFS4ERR_NO_GRACE:
1416		case -NFS4ERR_STALE_CLIENTID:
1417		case -NFS4ERR_BADSESSION:
1418		case -NFS4ERR_BADSLOT:
1419		case -NFS4ERR_BAD_HIGH_SLOT:
1420		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1421			goto out;
1422		default:
1423			pr_err("NFS: %s: unhandled error %d\n",
1424					__func__, status);
1425		case -ENOMEM:
1426		case -NFS4ERR_DENIED:
1427		case -NFS4ERR_RECLAIM_BAD:
1428		case -NFS4ERR_RECLAIM_CONFLICT:
1429			/* kill_proc(fl->fl_pid, SIGLOST, 1); */
1430			status = 0;
1431		}
1432		spin_lock(&flctx->flc_lock);
1433	}
1434	if (list == &flctx->flc_posix) {
1435		list = &flctx->flc_flock;
1436		goto restart;
1437	}
1438	spin_unlock(&flctx->flc_lock);
1439out:
1440	up_write(&nfsi->rwsem);
1441	return status;
1442}
1443
1444static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1445{
1446	struct nfs4_state *state;
1447	struct nfs4_lock_state *lock;
1448	int status = 0;
1449
1450	/* Note: we rely on the sp->so_states list being ordered
1451	 * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1452	 * states first.
1453	 * This is needed to ensure that the server won't give us any
1454	 * read delegations that we have to return if, say, we are
1455	 * recovering after a network partition or a reboot from a
1456	 * server that doesn't support a grace period.
1457	 */
1458	spin_lock(&sp->so_lock);
1459	raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1460restart:
1461	list_for_each_entry(state, &sp->so_states, open_states) {
1462		if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1463			continue;
1464		if (!nfs4_valid_open_stateid(state))
1465			continue;
1466		if (state->state == 0)
1467			continue;
1468		atomic_inc(&state->count);
1469		spin_unlock(&sp->so_lock);
1470		status = ops->recover_open(sp, state);
1471		if (status >= 0) {
1472			status = nfs4_reclaim_locks(state, ops);
1473			if (status >= 0) {
1474				if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1475					spin_lock(&state->state_lock);
1476					list_for_each_entry(lock, &state->lock_states, ls_locks) {
1477						if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1478							pr_warn_ratelimited("NFS: "
1479									    "%s: Lock reclaim "
1480									    "failed!\n", __func__);
1481					}
1482					spin_unlock(&state->state_lock);
1483				}
1484				nfs4_put_open_state(state);
1485				clear_bit(NFS4CLNT_RECLAIM_NOGRACE,
1486					&state->flags);
1487				spin_lock(&sp->so_lock);
1488				goto restart;
1489			}
1490		}
1491		switch (status) {
1492			default:
1493				printk(KERN_ERR "NFS: %s: unhandled error %d\n",
1494					__func__, status);
1495			case -ENOENT:
1496			case -ENOMEM:
1497			case -ESTALE:
1498				/* Open state on this file cannot be recovered */
1499				nfs4_state_mark_recovery_failed(state, status);
1500				break;
1501			case -EAGAIN:
1502				ssleep(1);
1503			case -NFS4ERR_ADMIN_REVOKED:
1504			case -NFS4ERR_STALE_STATEID:
1505			case -NFS4ERR_BAD_STATEID:
1506			case -NFS4ERR_RECLAIM_BAD:
1507			case -NFS4ERR_RECLAIM_CONFLICT:
1508				nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1509				break;
1510			case -NFS4ERR_EXPIRED:
1511			case -NFS4ERR_NO_GRACE:
1512				nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1513			case -NFS4ERR_STALE_CLIENTID:
1514			case -NFS4ERR_BADSESSION:
1515			case -NFS4ERR_BADSLOT:
1516			case -NFS4ERR_BAD_HIGH_SLOT:
1517			case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1518				goto out_err;
1519		}
1520		nfs4_put_open_state(state);
1521		spin_lock(&sp->so_lock);
1522		goto restart;
1523	}
1524	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1525	spin_unlock(&sp->so_lock);
1526	return 0;
1527out_err:
1528	nfs4_put_open_state(state);
1529	spin_lock(&sp->so_lock);
1530	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1531	spin_unlock(&sp->so_lock);
1532	return status;
1533}
1534
1535static void nfs4_clear_open_state(struct nfs4_state *state)
1536{
1537	struct nfs4_lock_state *lock;
1538
1539	clear_bit(NFS_DELEGATED_STATE, &state->flags);
1540	clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1541	clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1542	clear_bit(NFS_O_RDWR_STATE, &state->flags);
1543	spin_lock(&state->state_lock);
1544	list_for_each_entry(lock, &state->lock_states, ls_locks) {
1545		lock->ls_seqid.flags = 0;
1546		clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1547	}
1548	spin_unlock(&state->state_lock);
1549}
1550
1551static void nfs4_reset_seqids(struct nfs_server *server,
1552	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1553{
1554	struct nfs_client *clp = server->nfs_client;
1555	struct nfs4_state_owner *sp;
1556	struct rb_node *pos;
1557	struct nfs4_state *state;
1558
1559	spin_lock(&clp->cl_lock);
1560	for (pos = rb_first(&server->state_owners);
1561	     pos != NULL;
1562	     pos = rb_next(pos)) {
1563		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1564		sp->so_seqid.flags = 0;
1565		spin_lock(&sp->so_lock);
1566		list_for_each_entry(state, &sp->so_states, open_states) {
1567			if (mark_reclaim(clp, state))
1568				nfs4_clear_open_state(state);
1569		}
1570		spin_unlock(&sp->so_lock);
1571	}
1572	spin_unlock(&clp->cl_lock);
1573}
1574
1575static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1576	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1577{
1578	struct nfs_server *server;
1579
1580	rcu_read_lock();
1581	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1582		nfs4_reset_seqids(server, mark_reclaim);
1583	rcu_read_unlock();
1584}
1585
1586static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1587{
1588	/* Mark all delegations for reclaim */
1589	nfs_delegation_mark_reclaim(clp);
1590	nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1591}
1592
1593static void nfs4_reclaim_complete(struct nfs_client *clp,
1594				 const struct nfs4_state_recovery_ops *ops,
1595				 struct rpc_cred *cred)
1596{
1597	/* Notify the server we're done reclaiming our state */
1598	if (ops->reclaim_complete)
1599		(void)ops->reclaim_complete(clp, cred);
1600}
1601
1602static void nfs4_clear_reclaim_server(struct nfs_server *server)
1603{
1604	struct nfs_client *clp = server->nfs_client;
1605	struct nfs4_state_owner *sp;
1606	struct rb_node *pos;
1607	struct nfs4_state *state;
1608
1609	spin_lock(&clp->cl_lock);
1610	for (pos = rb_first(&server->state_owners);
1611	     pos != NULL;
1612	     pos = rb_next(pos)) {
1613		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1614		spin_lock(&sp->so_lock);
1615		list_for_each_entry(state, &sp->so_states, open_states) {
1616			if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1617						&state->flags))
1618				continue;
1619			nfs4_state_mark_reclaim_nograce(clp, state);
1620		}
1621		spin_unlock(&sp->so_lock);
1622	}
1623	spin_unlock(&clp->cl_lock);
1624}
1625
1626static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1627{
1628	struct nfs_server *server;
1629
1630	if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1631		return 0;
1632
1633	rcu_read_lock();
1634	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1635		nfs4_clear_reclaim_server(server);
1636	rcu_read_unlock();
1637
1638	nfs_delegation_reap_unclaimed(clp);
1639	return 1;
1640}
1641
1642static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1643{
1644	const struct nfs4_state_recovery_ops *ops;
1645	struct rpc_cred *cred;
1646
1647	if (!nfs4_state_clear_reclaim_reboot(clp))
1648		return;
1649	ops = clp->cl_mvops->reboot_recovery_ops;
1650	cred = nfs4_get_clid_cred(clp);
1651	nfs4_reclaim_complete(clp, ops, cred);
1652	put_rpccred(cred);
1653}
1654
1655static void nfs_delegation_clear_all(struct nfs_client *clp)
1656{
1657	nfs_delegation_mark_reclaim(clp);
1658	nfs_delegation_reap_unclaimed(clp);
1659}
1660
1661static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1662{
1663	nfs_delegation_clear_all(clp);
1664	nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1665}
1666
1667static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1668{
1669	switch (error) {
1670		case 0:
1671			break;
1672		case -NFS4ERR_CB_PATH_DOWN:
1673			nfs40_handle_cb_pathdown(clp);
1674			break;
1675		case -NFS4ERR_NO_GRACE:
1676			nfs4_state_end_reclaim_reboot(clp);
1677			break;
1678		case -NFS4ERR_STALE_CLIENTID:
1679			set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1680			nfs4_state_clear_reclaim_reboot(clp);
1681			nfs4_state_start_reclaim_reboot(clp);
1682			break;
1683		case -NFS4ERR_EXPIRED:
1684			set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1685			nfs4_state_start_reclaim_nograce(clp);
1686			break;
1687		case -NFS4ERR_BADSESSION:
1688		case -NFS4ERR_BADSLOT:
1689		case -NFS4ERR_BAD_HIGH_SLOT:
1690		case -NFS4ERR_DEADSESSION:
1691		case -NFS4ERR_SEQ_FALSE_RETRY:
1692		case -NFS4ERR_SEQ_MISORDERED:
1693			set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1694			/* Zero session reset errors */
1695			break;
1696		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1697			set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1698			break;
1699		default:
1700			dprintk("%s: failed to handle error %d for server %s\n",
1701					__func__, error, clp->cl_hostname);
1702			return error;
1703	}
1704	dprintk("%s: handled error %d for server %s\n", __func__, error,
1705			clp->cl_hostname);
1706	return 0;
1707}
1708
1709static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1710{
1711	struct nfs4_state_owner *sp;
1712	struct nfs_server *server;
1713	struct rb_node *pos;
1714	int status = 0;
1715
1716restart:
1717	rcu_read_lock();
1718	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1719		nfs4_purge_state_owners(server);
1720		spin_lock(&clp->cl_lock);
1721		for (pos = rb_first(&server->state_owners);
1722		     pos != NULL;
1723		     pos = rb_next(pos)) {
1724			sp = rb_entry(pos,
1725				struct nfs4_state_owner, so_server_node);
1726			if (!test_and_clear_bit(ops->owner_flag_bit,
1727							&sp->so_flags))
1728				continue;
1729			atomic_inc(&sp->so_count);
1730			spin_unlock(&clp->cl_lock);
1731			rcu_read_unlock();
1732
1733			status = nfs4_reclaim_open_state(sp, ops);
1734			if (status < 0) {
1735				set_bit(ops->owner_flag_bit, &sp->so_flags);
1736				nfs4_put_state_owner(sp);
1737				status = nfs4_recovery_handle_error(clp, status);
1738				return (status != 0) ? status : -EAGAIN;
1739			}
1740
1741			nfs4_put_state_owner(sp);
1742			goto restart;
1743		}
1744		spin_unlock(&clp->cl_lock);
1745	}
1746	rcu_read_unlock();
1747	return 0;
1748}
1749
1750static int nfs4_check_lease(struct nfs_client *clp)
1751{
1752	struct rpc_cred *cred;
1753	const struct nfs4_state_maintenance_ops *ops =
1754		clp->cl_mvops->state_renewal_ops;
1755	int status;
1756
1757	/* Is the client already known to have an expired lease? */
1758	if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1759		return 0;
1760	spin_lock(&clp->cl_lock);
1761	cred = ops->get_state_renewal_cred_locked(clp);
1762	spin_unlock(&clp->cl_lock);
1763	if (cred == NULL) {
1764		cred = nfs4_get_clid_cred(clp);
1765		status = -ENOKEY;
1766		if (cred == NULL)
1767			goto out;
1768	}
1769	status = ops->renew_lease(clp, cred);
1770	put_rpccred(cred);
1771	if (status == -ETIMEDOUT) {
1772		set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1773		return 0;
1774	}
1775out:
1776	return nfs4_recovery_handle_error(clp, status);
1777}
1778
1779/* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1780 * and for recoverable errors on EXCHANGE_ID for v4.1
1781 */
1782static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1783{
1784	switch (status) {
1785	case -NFS4ERR_SEQ_MISORDERED:
1786		if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1787			return -ESERVERFAULT;
1788		/* Lease confirmation error: retry after purging the lease */
1789		ssleep(1);
1790		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1791		break;
1792	case -NFS4ERR_STALE_CLIENTID:
1793		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1794		nfs4_state_start_reclaim_reboot(clp);
1795		break;
1796	case -NFS4ERR_CLID_INUSE:
1797		pr_err("NFS: Server %s reports our clientid is in use\n",
1798			clp->cl_hostname);
1799		nfs_mark_client_ready(clp, -EPERM);
1800		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1801		return -EPERM;
1802	case -EACCES:
1803	case -NFS4ERR_DELAY:
1804	case -ETIMEDOUT:
1805	case -EAGAIN:
1806		ssleep(1);
1807		break;
1808
1809	case -NFS4ERR_MINOR_VERS_MISMATCH:
1810		if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
1811			nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
1812		dprintk("%s: exit with error %d for server %s\n",
1813				__func__, -EPROTONOSUPPORT, clp->cl_hostname);
1814		return -EPROTONOSUPPORT;
1815	case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1816				 * in nfs4_exchange_id */
1817	default:
1818		dprintk("%s: exit with error %d for server %s\n", __func__,
1819				status, clp->cl_hostname);
1820		return status;
1821	}
1822	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1823	dprintk("%s: handled error %d for server %s\n", __func__, status,
1824			clp->cl_hostname);
1825	return 0;
1826}
1827
1828static int nfs4_establish_lease(struct nfs_client *clp)
1829{
1830	struct rpc_cred *cred;
1831	const struct nfs4_state_recovery_ops *ops =
1832		clp->cl_mvops->reboot_recovery_ops;
1833	int status;
1834
1835	cred = nfs4_get_clid_cred(clp);
1836	if (cred == NULL)
1837		return -ENOENT;
1838	status = ops->establish_clid(clp, cred);
1839	put_rpccred(cred);
1840	if (status != 0)
1841		return status;
1842	pnfs_destroy_all_layouts(clp);
1843	return 0;
1844}
1845
1846/*
1847 * Returns zero or a negative errno.  NFS4ERR values are converted
1848 * to local errno values.
1849 */
1850static int nfs4_reclaim_lease(struct nfs_client *clp)
1851{
1852	int status;
1853
1854	status = nfs4_establish_lease(clp);
1855	if (status < 0)
1856		return nfs4_handle_reclaim_lease_error(clp, status);
1857	if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
1858		nfs4_state_start_reclaim_nograce(clp);
1859	if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
1860		set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1861	clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1862	clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1863	return 0;
1864}
1865
1866static int nfs4_purge_lease(struct nfs_client *clp)
1867{
1868	int status;
1869
1870	status = nfs4_establish_lease(clp);
1871	if (status < 0)
1872		return nfs4_handle_reclaim_lease_error(clp, status);
1873	clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
1874	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1875	nfs4_state_start_reclaim_nograce(clp);
1876	return 0;
1877}
1878
1879/*
1880 * Try remote migration of one FSID from a source server to a
1881 * destination server.  The source server provides a list of
1882 * potential destinations.
1883 *
1884 * Returns zero or a negative NFS4ERR status code.
1885 */
1886static int nfs4_try_migration(struct nfs_server *server, struct rpc_cred *cred)
1887{
1888	struct nfs_client *clp = server->nfs_client;
1889	struct nfs4_fs_locations *locations = NULL;
1890	struct inode *inode;
1891	struct page *page;
1892	int status, result;
1893
1894	dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
1895			(unsigned long long)server->fsid.major,
1896			(unsigned long long)server->fsid.minor,
1897			clp->cl_hostname);
1898
1899	result = 0;
1900	page = alloc_page(GFP_KERNEL);
1901	locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
1902	if (page == NULL || locations == NULL) {
1903		dprintk("<-- %s: no memory\n", __func__);
1904		goto out;
1905	}
1906
1907	inode = d_inode(server->super->s_root);
1908	result = nfs4_proc_get_locations(inode, locations, page, cred);
1909	if (result) {
1910		dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
1911			__func__, result);
1912		goto out;
1913	}
1914
1915	result = -NFS4ERR_NXIO;
1916	if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
1917		dprintk("<-- %s: No fs_locations data, migration skipped\n",
1918			__func__);
1919		goto out;
1920	}
1921
1922	nfs4_begin_drain_session(clp);
1923
1924	status = nfs4_replace_transport(server, locations);
1925	if (status != 0) {
1926		dprintk("<-- %s: failed to replace transport: %d\n",
1927			__func__, status);
1928		goto out;
1929	}
1930
1931	result = 0;
1932	dprintk("<-- %s: migration succeeded\n", __func__);
1933
1934out:
1935	if (page != NULL)
1936		__free_page(page);
1937	kfree(locations);
1938	if (result) {
1939		pr_err("NFS: migration recovery failed (server %s)\n",
1940				clp->cl_hostname);
1941		set_bit(NFS_MIG_FAILED, &server->mig_status);
1942	}
1943	return result;
1944}
1945
1946/*
1947 * Returns zero or a negative NFS4ERR status code.
1948 */
1949static int nfs4_handle_migration(struct nfs_client *clp)
1950{
1951	const struct nfs4_state_maintenance_ops *ops =
1952				clp->cl_mvops->state_renewal_ops;
1953	struct nfs_server *server;
1954	struct rpc_cred *cred;
1955
1956	dprintk("%s: migration reported on \"%s\"\n", __func__,
1957			clp->cl_hostname);
1958
1959	spin_lock(&clp->cl_lock);
1960	cred = ops->get_state_renewal_cred_locked(clp);
1961	spin_unlock(&clp->cl_lock);
1962	if (cred == NULL)
1963		return -NFS4ERR_NOENT;
1964
1965	clp->cl_mig_gen++;
1966restart:
1967	rcu_read_lock();
1968	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1969		int status;
1970
1971		if (server->mig_gen == clp->cl_mig_gen)
1972			continue;
1973		server->mig_gen = clp->cl_mig_gen;
1974
1975		if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
1976						&server->mig_status))
1977			continue;
1978
1979		rcu_read_unlock();
1980		status = nfs4_try_migration(server, cred);
1981		if (status < 0) {
1982			put_rpccred(cred);
1983			return status;
1984		}
1985		goto restart;
1986	}
1987	rcu_read_unlock();
1988	put_rpccred(cred);
1989	return 0;
1990}
1991
1992/*
1993 * Test each nfs_server on the clp's cl_superblocks list to see
1994 * if it's moved to another server.  Stop when the server no longer
1995 * returns NFS4ERR_LEASE_MOVED.
1996 */
1997static int nfs4_handle_lease_moved(struct nfs_client *clp)
1998{
1999	const struct nfs4_state_maintenance_ops *ops =
2000				clp->cl_mvops->state_renewal_ops;
2001	struct nfs_server *server;
2002	struct rpc_cred *cred;
2003
2004	dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2005			clp->cl_hostname);
2006
2007	spin_lock(&clp->cl_lock);
2008	cred = ops->get_state_renewal_cred_locked(clp);
2009	spin_unlock(&clp->cl_lock);
2010	if (cred == NULL)
2011		return -NFS4ERR_NOENT;
2012
2013	clp->cl_mig_gen++;
2014restart:
2015	rcu_read_lock();
2016	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2017		struct inode *inode;
2018		int status;
2019
2020		if (server->mig_gen == clp->cl_mig_gen)
2021			continue;
2022		server->mig_gen = clp->cl_mig_gen;
2023
2024		rcu_read_unlock();
2025
2026		inode = d_inode(server->super->s_root);
2027		status = nfs4_proc_fsid_present(inode, cred);
2028		if (status != -NFS4ERR_MOVED)
2029			goto restart;	/* wasn't this one */
2030		if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2031			goto restart;	/* there are more */
2032		goto out;
2033	}
2034	rcu_read_unlock();
2035
2036out:
2037	put_rpccred(cred);
2038	return 0;
2039}
2040
2041/**
2042 * nfs4_discover_server_trunking - Detect server IP address trunking
2043 *
2044 * @clp: nfs_client under test
2045 * @result: OUT: found nfs_client, or clp
2046 *
2047 * Returns zero or a negative errno.  If zero is returned,
2048 * an nfs_client pointer is planted in "result".
2049 *
2050 * Note: since we are invoked in process context, and
2051 * not from inside the state manager, we cannot use
2052 * nfs4_handle_reclaim_lease_error().
2053 */
2054int nfs4_discover_server_trunking(struct nfs_client *clp,
2055				  struct nfs_client **result)
2056{
2057	const struct nfs4_state_recovery_ops *ops =
2058				clp->cl_mvops->reboot_recovery_ops;
2059	struct rpc_clnt *clnt;
2060	struct rpc_cred *cred;
2061	int i, status;
2062
2063	dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2064
2065	clnt = clp->cl_rpcclient;
2066	i = 0;
2067
2068	mutex_lock(&nfs_clid_init_mutex);
2069again:
2070	status  = -ENOENT;
2071	cred = nfs4_get_clid_cred(clp);
2072	if (cred == NULL)
2073		goto out_unlock;
2074
2075	status = ops->detect_trunking(clp, result, cred);
2076	put_rpccred(cred);
2077	switch (status) {
2078	case 0:
2079		break;
2080	case -ETIMEDOUT:
2081		if (clnt->cl_softrtry)
2082			break;
2083	case -NFS4ERR_DELAY:
2084	case -EAGAIN:
2085		ssleep(1);
2086	case -NFS4ERR_STALE_CLIENTID:
2087		dprintk("NFS: %s after status %d, retrying\n",
2088			__func__, status);
2089		goto again;
2090	case -EACCES:
2091		if (i++ == 0) {
2092			nfs4_root_machine_cred(clp);
2093			goto again;
2094		}
2095		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2096			break;
2097	case -NFS4ERR_CLID_INUSE:
2098	case -NFS4ERR_WRONGSEC:
2099		/* No point in retrying if we already used RPC_AUTH_UNIX */
2100		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2101			status = -EPERM;
2102			break;
2103		}
2104		clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2105		if (IS_ERR(clnt)) {
2106			status = PTR_ERR(clnt);
2107			break;
2108		}
2109		/* Note: this is safe because we haven't yet marked the
2110		 * client as ready, so we are the only user of
2111		 * clp->cl_rpcclient
2112		 */
2113		clnt = xchg(&clp->cl_rpcclient, clnt);
2114		rpc_shutdown_client(clnt);
2115		clnt = clp->cl_rpcclient;
2116		goto again;
2117
2118	case -NFS4ERR_MINOR_VERS_MISMATCH:
2119		status = -EPROTONOSUPPORT;
2120		break;
2121
2122	case -EKEYEXPIRED:
2123	case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2124				 * in nfs4_exchange_id */
2125		status = -EKEYEXPIRED;
2126		break;
2127	default:
2128		pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2129				__func__, status);
2130		status = -EIO;
2131	}
2132
2133out_unlock:
2134	mutex_unlock(&nfs_clid_init_mutex);
2135	dprintk("NFS: %s: status = %d\n", __func__, status);
2136	return status;
2137}
2138
2139#ifdef CONFIG_NFS_V4_1
2140void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2141{
2142	struct nfs_client *clp = session->clp;
2143
2144	switch (err) {
2145	default:
2146		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2147		break;
2148	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2149		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2150	}
2151	nfs4_schedule_lease_recovery(clp);
2152}
2153EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2154
2155static void nfs41_ping_server(struct nfs_client *clp)
2156{
2157	/* Use CHECK_LEASE to ping the server with a SEQUENCE */
2158	set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2159	nfs4_schedule_state_manager(clp);
2160}
2161
2162void nfs41_server_notify_target_slotid_update(struct nfs_client *clp)
2163{
2164	nfs41_ping_server(clp);
2165}
2166
2167void nfs41_server_notify_highest_slotid_update(struct nfs_client *clp)
2168{
2169	nfs41_ping_server(clp);
2170}
2171
2172static void nfs4_reset_all_state(struct nfs_client *clp)
2173{
2174	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2175		set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2176		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2177		nfs4_state_start_reclaim_nograce(clp);
2178		dprintk("%s: scheduling reset of all state for server %s!\n",
2179				__func__, clp->cl_hostname);
2180		nfs4_schedule_state_manager(clp);
2181	}
2182}
2183
2184static void nfs41_handle_server_reboot(struct nfs_client *clp)
2185{
2186	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2187		nfs4_state_start_reclaim_reboot(clp);
2188		dprintk("%s: server %s rebooted!\n", __func__,
2189				clp->cl_hostname);
2190		nfs4_schedule_state_manager(clp);
2191	}
2192}
2193
2194static void nfs41_handle_state_revoked(struct nfs_client *clp)
2195{
2196	nfs4_reset_all_state(clp);
2197	dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2198}
2199
2200static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2201{
2202	/* This will need to handle layouts too */
2203	nfs_expire_all_delegations(clp);
2204	dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2205			clp->cl_hostname);
2206}
2207
2208static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2209{
2210	nfs_expire_all_delegations(clp);
2211	if (test_and_set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state) == 0)
2212		nfs4_schedule_state_manager(clp);
2213	dprintk("%s: server %s declared a backchannel fault\n", __func__,
2214			clp->cl_hostname);
2215}
2216
2217static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2218{
2219	if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2220		&clp->cl_state) == 0)
2221		nfs4_schedule_state_manager(clp);
2222}
2223
2224void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags)
2225{
2226	if (!flags)
2227		return;
2228
2229	dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2230		__func__, clp->cl_hostname, clp->cl_clientid, flags);
2231
2232	if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2233		nfs41_handle_server_reboot(clp);
2234	if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED |
2235			    SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2236			    SEQ4_STATUS_ADMIN_STATE_REVOKED))
2237		nfs41_handle_state_revoked(clp);
2238	if (flags & SEQ4_STATUS_LEASE_MOVED)
2239		nfs4_schedule_lease_moved_recovery(clp);
2240	if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2241		nfs41_handle_recallable_state_revoked(clp);
2242	if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2243		nfs41_handle_backchannel_fault(clp);
2244	else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2245				SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2246		nfs41_handle_cb_path_down(clp);
2247}
2248
2249static int nfs4_reset_session(struct nfs_client *clp)
2250{
2251	struct rpc_cred *cred;
2252	int status;
2253
2254	if (!nfs4_has_session(clp))
2255		return 0;
2256	nfs4_begin_drain_session(clp);
2257	cred = nfs4_get_clid_cred(clp);
2258	status = nfs4_proc_destroy_session(clp->cl_session, cred);
2259	switch (status) {
2260	case 0:
2261	case -NFS4ERR_BADSESSION:
2262	case -NFS4ERR_DEADSESSION:
2263		break;
2264	case -NFS4ERR_BACK_CHAN_BUSY:
2265	case -NFS4ERR_DELAY:
2266		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2267		status = 0;
2268		ssleep(1);
2269		goto out;
2270	default:
2271		status = nfs4_recovery_handle_error(clp, status);
2272		goto out;
2273	}
2274
2275	memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2276	status = nfs4_proc_create_session(clp, cred);
2277	if (status) {
2278		dprintk("%s: session reset failed with status %d for server %s!\n",
2279			__func__, status, clp->cl_hostname);
2280		status = nfs4_handle_reclaim_lease_error(clp, status);
2281		goto out;
2282	}
2283	nfs41_finish_session_reset(clp);
2284	dprintk("%s: session reset was successful for server %s!\n",
2285			__func__, clp->cl_hostname);
2286out:
2287	if (cred)
2288		put_rpccred(cred);
2289	return status;
2290}
2291
2292static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2293{
2294	struct rpc_cred *cred;
2295	int ret;
2296
2297	if (!nfs4_has_session(clp))
2298		return 0;
2299	nfs4_begin_drain_session(clp);
2300	cred = nfs4_get_clid_cred(clp);
2301	ret = nfs4_proc_bind_conn_to_session(clp, cred);
2302	if (cred)
2303		put_rpccred(cred);
2304	clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2305	switch (ret) {
2306	case 0:
2307		dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2308			__func__, clp->cl_hostname);
2309		break;
2310	case -NFS4ERR_DELAY:
2311		ssleep(1);
2312		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2313		break;
2314	default:
2315		return nfs4_recovery_handle_error(clp, ret);
2316	}
2317	return 0;
2318}
2319#else /* CONFIG_NFS_V4_1 */
2320static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2321
2322static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2323{
2324	return 0;
2325}
2326#endif /* CONFIG_NFS_V4_1 */
2327
2328static void nfs4_state_manager(struct nfs_client *clp)
2329{
2330	int status = 0;
2331	const char *section = "", *section_sep = "";
2332
2333	/* Ensure exclusive access to NFSv4 state */
2334	do {
2335		if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2336			section = "purge state";
2337			status = nfs4_purge_lease(clp);
2338			if (status < 0)
2339				goto out_error;
2340			continue;
2341		}
2342
2343		if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2344			section = "lease expired";
2345			/* We're going to have to re-establish a clientid */
2346			status = nfs4_reclaim_lease(clp);
2347			if (status < 0)
2348				goto out_error;
2349			continue;
2350		}
2351
2352		/* Initialize or reset the session */
2353		if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2354			section = "reset session";
2355			status = nfs4_reset_session(clp);
2356			if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2357				continue;
2358			if (status < 0)
2359				goto out_error;
2360		}
2361
2362		/* Send BIND_CONN_TO_SESSION */
2363		if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2364				&clp->cl_state)) {
2365			section = "bind conn to session";
2366			status = nfs4_bind_conn_to_session(clp);
2367			if (status < 0)
2368				goto out_error;
2369			continue;
2370		}
2371
2372		if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2373			section = "check lease";
2374			status = nfs4_check_lease(clp);
2375			if (status < 0)
2376				goto out_error;
2377			continue;
2378		}
2379
2380		if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2381			section = "migration";
2382			status = nfs4_handle_migration(clp);
2383			if (status < 0)
2384				goto out_error;
2385		}
2386
2387		if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2388			section = "lease moved";
2389			status = nfs4_handle_lease_moved(clp);
2390			if (status < 0)
2391				goto out_error;
2392		}
2393
2394		/* First recover reboot state... */
2395		if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2396			section = "reclaim reboot";
2397			status = nfs4_do_reclaim(clp,
2398				clp->cl_mvops->reboot_recovery_ops);
2399			if (status == -EAGAIN)
2400				continue;
2401			if (status < 0)
2402				goto out_error;
2403			nfs4_state_end_reclaim_reboot(clp);
2404		}
2405
2406		/* Now recover expired state... */
2407		if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2408			section = "reclaim nograce";
2409			status = nfs4_do_reclaim(clp,
2410				clp->cl_mvops->nograce_recovery_ops);
2411			if (status == -EAGAIN)
2412				continue;
2413			if (status < 0)
2414				goto out_error;
2415		}
2416
2417		nfs4_end_drain_session(clp);
2418		if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2419			nfs_client_return_marked_delegations(clp);
2420			continue;
2421		}
2422
2423		nfs4_clear_state_manager_bit(clp);
2424		/* Did we race with an attempt to give us more work? */
2425		if (clp->cl_state == 0)
2426			break;
2427		if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2428			break;
2429	} while (atomic_read(&clp->cl_count) > 1);
2430	return;
2431out_error:
2432	if (strlen(section))
2433		section_sep = ": ";
2434	pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2435			" with error %d\n", section_sep, section,
2436			clp->cl_hostname, -status);
2437	ssleep(1);
2438	nfs4_end_drain_session(clp);
2439	nfs4_clear_state_manager_bit(clp);
2440}
2441
2442static int nfs4_run_state_manager(void *ptr)
2443{
2444	struct nfs_client *clp = ptr;
2445
2446	allow_signal(SIGKILL);
2447	nfs4_state_manager(clp);
2448	nfs_put_client(clp);
2449	module_put_and_exit(0);
2450	return 0;
2451}
2452
2453/*
2454 * Local variables:
2455 *  c-basic-offset: 8
2456 * End:
2457 */
2458