1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/fs/nfs/delegation.c
4 *
5 * Copyright (C) 2004 Trond Myklebust
6 *
7 * NFS file delegation management
8 *
9 */
10 #include <linux/completion.h>
11 #include <linux/kthread.h>
12 #include <linux/module.h>
13 #include <linux/sched.h>
14 #include <linux/slab.h>
15 #include <linux/spinlock.h>
16 #include <linux/iversion.h>
17
18 #include <linux/nfs4.h>
19 #include <linux/nfs_fs.h>
20 #include <linux/nfs_xdr.h>
21
22 #include "nfs4_fs.h"
23 #include "nfs4session.h"
24 #include "delegation.h"
25 #include "internal.h"
26 #include "nfs4trace.h"
27
28 #define NFS_DEFAULT_DELEGATION_WATERMARK (5000U)
29
30 static atomic_long_t nfs_active_delegations;
31 static unsigned nfs_delegation_watermark = NFS_DEFAULT_DELEGATION_WATERMARK;
32
__nfs_free_delegation(struct nfs_delegation * delegation)33 static void __nfs_free_delegation(struct nfs_delegation *delegation)
34 {
35 put_cred(delegation->cred);
36 delegation->cred = NULL;
37 kfree_rcu(delegation, rcu);
38 }
39
nfs_mark_delegation_revoked(struct nfs_delegation * delegation)40 static void nfs_mark_delegation_revoked(struct nfs_delegation *delegation)
41 {
42 if (!test_and_set_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
43 delegation->stateid.type = NFS4_INVALID_STATEID_TYPE;
44 atomic_long_dec(&nfs_active_delegations);
45 if (!test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
46 nfs_clear_verifier_delegated(delegation->inode);
47 }
48 }
49
nfs_get_delegation(struct nfs_delegation * delegation)50 static struct nfs_delegation *nfs_get_delegation(struct nfs_delegation *delegation)
51 {
52 refcount_inc(&delegation->refcount);
53 return delegation;
54 }
55
nfs_put_delegation(struct nfs_delegation * delegation)56 static void nfs_put_delegation(struct nfs_delegation *delegation)
57 {
58 if (refcount_dec_and_test(&delegation->refcount))
59 __nfs_free_delegation(delegation);
60 }
61
nfs_free_delegation(struct nfs_delegation * delegation)62 static void nfs_free_delegation(struct nfs_delegation *delegation)
63 {
64 nfs_mark_delegation_revoked(delegation);
65 nfs_put_delegation(delegation);
66 }
67
68 /**
69 * nfs_mark_delegation_referenced - set delegation's REFERENCED flag
70 * @delegation: delegation to process
71 *
72 */
nfs_mark_delegation_referenced(struct nfs_delegation * delegation)73 void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
74 {
75 set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
76 }
77
nfs_mark_return_delegation(struct nfs_server * server,struct nfs_delegation * delegation)78 static void nfs_mark_return_delegation(struct nfs_server *server,
79 struct nfs_delegation *delegation)
80 {
81 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
82 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
83 }
84
nfs4_is_valid_delegation(const struct nfs_delegation * delegation,fmode_t type)85 static bool nfs4_is_valid_delegation(const struct nfs_delegation *delegation,
86 fmode_t type)
87 {
88 if (delegation != NULL && (delegation->type & type) == type &&
89 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
90 !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
91 return true;
92 return false;
93 }
94
nfs4_get_valid_delegation(const struct inode * inode)95 struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode)
96 {
97 struct nfs_delegation *delegation;
98
99 delegation = rcu_dereference(NFS_I(inode)->delegation);
100 if (nfs4_is_valid_delegation(delegation, 0))
101 return delegation;
102 return NULL;
103 }
104
nfs4_do_check_delegation(struct inode * inode,fmode_t type,int flags,bool mark)105 static int nfs4_do_check_delegation(struct inode *inode, fmode_t type,
106 int flags, bool mark)
107 {
108 struct nfs_delegation *delegation;
109 int ret = 0;
110
111 type &= FMODE_READ|FMODE_WRITE;
112 rcu_read_lock();
113 delegation = rcu_dereference(NFS_I(inode)->delegation);
114 if (nfs4_is_valid_delegation(delegation, type)) {
115 if (mark)
116 nfs_mark_delegation_referenced(delegation);
117 ret = 1;
118 if ((flags & NFS_DELEGATION_FLAG_TIME) &&
119 !test_bit(NFS_DELEGATION_DELEGTIME, &delegation->flags))
120 ret = 0;
121 }
122 rcu_read_unlock();
123 return ret;
124 }
125 /**
126 * nfs4_have_delegation - check if inode has a delegation, mark it
127 * NFS_DELEGATION_REFERENCED if there is one.
128 * @inode: inode to check
129 * @type: delegation types to check for
130 * @flags: various modifiers
131 *
132 * Returns one if inode has the indicated delegation, otherwise zero.
133 */
nfs4_have_delegation(struct inode * inode,fmode_t type,int flags)134 int nfs4_have_delegation(struct inode *inode, fmode_t type, int flags)
135 {
136 return nfs4_do_check_delegation(inode, type, flags, true);
137 }
138
139 /*
140 * nfs4_check_delegation - check if inode has a delegation, do not mark
141 * NFS_DELEGATION_REFERENCED if it has one.
142 */
nfs4_check_delegation(struct inode * inode,fmode_t type)143 int nfs4_check_delegation(struct inode *inode, fmode_t type)
144 {
145 return nfs4_do_check_delegation(inode, type, 0, false);
146 }
147
nfs_delegation_claim_locks(struct nfs4_state * state,const nfs4_stateid * stateid)148 static int nfs_delegation_claim_locks(struct nfs4_state *state, const nfs4_stateid *stateid)
149 {
150 struct inode *inode = state->inode;
151 struct file_lock *fl;
152 struct file_lock_context *flctx = locks_inode_context(inode);
153 struct list_head *list;
154 int status = 0;
155
156 if (flctx == NULL)
157 goto out;
158
159 list = &flctx->flc_posix;
160 spin_lock(&flctx->flc_lock);
161 restart:
162 for_each_file_lock(fl, list) {
163 if (nfs_file_open_context(fl->c.flc_file)->state != state)
164 continue;
165 spin_unlock(&flctx->flc_lock);
166 status = nfs4_lock_delegation_recall(fl, state, stateid);
167 if (status < 0)
168 goto out;
169 spin_lock(&flctx->flc_lock);
170 }
171 if (list == &flctx->flc_posix) {
172 list = &flctx->flc_flock;
173 goto restart;
174 }
175 spin_unlock(&flctx->flc_lock);
176 out:
177 return status;
178 }
179
nfs_delegation_claim_opens(struct inode * inode,const nfs4_stateid * stateid,fmode_t type)180 static int nfs_delegation_claim_opens(struct inode *inode,
181 const nfs4_stateid *stateid, fmode_t type)
182 {
183 struct nfs_inode *nfsi = NFS_I(inode);
184 struct nfs_open_context *ctx;
185 struct nfs4_state_owner *sp;
186 struct nfs4_state *state;
187 int err;
188
189 again:
190 rcu_read_lock();
191 list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
192 state = ctx->state;
193 if (state == NULL)
194 continue;
195 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
196 continue;
197 if (!nfs4_valid_open_stateid(state))
198 continue;
199 if (!nfs4_stateid_match(&state->stateid, stateid))
200 continue;
201 if (!get_nfs_open_context(ctx))
202 continue;
203 rcu_read_unlock();
204 sp = state->owner;
205 /* Block nfs4_proc_unlck */
206 mutex_lock(&sp->so_delegreturn_mutex);
207 err = nfs4_open_delegation_recall(ctx, state, stateid);
208 if (!err)
209 err = nfs_delegation_claim_locks(state, stateid);
210 mutex_unlock(&sp->so_delegreturn_mutex);
211 put_nfs_open_context(ctx);
212 if (err != 0)
213 return err;
214 goto again;
215 }
216 rcu_read_unlock();
217 return 0;
218 }
219
220 /**
221 * nfs_inode_reclaim_delegation - process a delegation reclaim request
222 * @inode: inode to process
223 * @cred: credential to use for request
224 * @type: delegation type
225 * @stateid: delegation stateid
226 * @pagemod_limit: write delegation "space_limit"
227 * @deleg_type: raw delegation type
228 *
229 */
nfs_inode_reclaim_delegation(struct inode * inode,const struct cred * cred,fmode_t type,const nfs4_stateid * stateid,unsigned long pagemod_limit,u32 deleg_type)230 void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred,
231 fmode_t type, const nfs4_stateid *stateid,
232 unsigned long pagemod_limit, u32 deleg_type)
233 {
234 struct nfs_delegation *delegation;
235 const struct cred *oldcred = NULL;
236
237 rcu_read_lock();
238 delegation = rcu_dereference(NFS_I(inode)->delegation);
239 if (delegation != NULL) {
240 spin_lock(&delegation->lock);
241 nfs4_stateid_copy(&delegation->stateid, stateid);
242 delegation->type = type;
243 delegation->pagemod_limit = pagemod_limit;
244 oldcred = delegation->cred;
245 delegation->cred = get_cred(cred);
246 switch (deleg_type) {
247 case NFS4_OPEN_DELEGATE_READ_ATTRS_DELEG:
248 case NFS4_OPEN_DELEGATE_WRITE_ATTRS_DELEG:
249 set_bit(NFS_DELEGATION_DELEGTIME, &delegation->flags);
250 break;
251 default:
252 clear_bit(NFS_DELEGATION_DELEGTIME, &delegation->flags);
253 }
254 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
255 if (test_and_clear_bit(NFS_DELEGATION_REVOKED,
256 &delegation->flags))
257 atomic_long_inc(&nfs_active_delegations);
258 spin_unlock(&delegation->lock);
259 rcu_read_unlock();
260 put_cred(oldcred);
261 trace_nfs4_reclaim_delegation(inode, type);
262 } else {
263 rcu_read_unlock();
264 nfs_inode_set_delegation(inode, cred, type, stateid,
265 pagemod_limit, deleg_type);
266 }
267 }
268
nfs_do_return_delegation(struct inode * inode,struct nfs_delegation * delegation,int issync)269 static int nfs_do_return_delegation(struct inode *inode,
270 struct nfs_delegation *delegation,
271 int issync)
272 {
273 const struct cred *cred;
274 int res = 0;
275
276 if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
277 spin_lock(&delegation->lock);
278 cred = get_cred(delegation->cred);
279 spin_unlock(&delegation->lock);
280 res = nfs4_proc_delegreturn(inode, cred, &delegation->stateid,
281 delegation, issync);
282 put_cred(cred);
283 }
284 return res;
285 }
286
nfs_delegation_grab_inode(struct nfs_delegation * delegation)287 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
288 {
289 struct inode *inode = NULL;
290
291 spin_lock(&delegation->lock);
292 if (delegation->inode != NULL)
293 inode = igrab(delegation->inode);
294 if (!inode)
295 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags);
296 spin_unlock(&delegation->lock);
297 return inode;
298 }
299
300 static struct nfs_delegation *
nfs_start_delegation_return_locked(struct nfs_inode * nfsi)301 nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
302 {
303 struct nfs_delegation *ret = NULL;
304 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
305
306 if (delegation == NULL)
307 goto out;
308 spin_lock(&delegation->lock);
309 if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
310 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags);
311 /* Refcount matched in nfs_end_delegation_return() */
312 ret = nfs_get_delegation(delegation);
313 }
314 spin_unlock(&delegation->lock);
315 if (ret)
316 nfs_clear_verifier_delegated(&nfsi->vfs_inode);
317 out:
318 return ret;
319 }
320
321 static struct nfs_delegation *
nfs_start_delegation_return(struct nfs_inode * nfsi)322 nfs_start_delegation_return(struct nfs_inode *nfsi)
323 {
324 struct nfs_delegation *delegation;
325
326 rcu_read_lock();
327 delegation = nfs_start_delegation_return_locked(nfsi);
328 rcu_read_unlock();
329 return delegation;
330 }
331
nfs_abort_delegation_return(struct nfs_delegation * delegation,struct nfs_client * clp,int err)332 static void nfs_abort_delegation_return(struct nfs_delegation *delegation,
333 struct nfs_client *clp, int err)
334 {
335
336 spin_lock(&delegation->lock);
337 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
338 if (err == -EAGAIN) {
339 set_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags);
340 set_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state);
341 }
342 spin_unlock(&delegation->lock);
343 }
344
345 static struct nfs_delegation *
nfs_detach_delegation_locked(struct nfs_inode * nfsi,struct nfs_delegation * delegation,struct nfs_client * clp)346 nfs_detach_delegation_locked(struct nfs_inode *nfsi,
347 struct nfs_delegation *delegation,
348 struct nfs_client *clp)
349 {
350 struct nfs_delegation *deleg_cur =
351 rcu_dereference_protected(nfsi->delegation,
352 lockdep_is_held(&clp->cl_lock));
353
354 if (deleg_cur == NULL || delegation != deleg_cur)
355 return NULL;
356
357 spin_lock(&delegation->lock);
358 if (!delegation->inode) {
359 spin_unlock(&delegation->lock);
360 return NULL;
361 }
362 list_del_rcu(&delegation->super_list);
363 delegation->inode = NULL;
364 rcu_assign_pointer(nfsi->delegation, NULL);
365 spin_unlock(&delegation->lock);
366 return delegation;
367 }
368
nfs_detach_delegation(struct nfs_inode * nfsi,struct nfs_delegation * delegation,struct nfs_server * server)369 static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
370 struct nfs_delegation *delegation,
371 struct nfs_server *server)
372 {
373 struct nfs_client *clp = server->nfs_client;
374
375 spin_lock(&clp->cl_lock);
376 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp);
377 spin_unlock(&clp->cl_lock);
378 return delegation;
379 }
380
381 static struct nfs_delegation *
nfs_inode_detach_delegation(struct inode * inode)382 nfs_inode_detach_delegation(struct inode *inode)
383 {
384 struct nfs_inode *nfsi = NFS_I(inode);
385 struct nfs_server *server = NFS_SERVER(inode);
386 struct nfs_delegation *delegation;
387
388 rcu_read_lock();
389 delegation = rcu_dereference(nfsi->delegation);
390 if (delegation != NULL)
391 delegation = nfs_detach_delegation(nfsi, delegation, server);
392 rcu_read_unlock();
393 return delegation;
394 }
395
396 static void
nfs_update_delegation_cred(struct nfs_delegation * delegation,const struct cred * cred)397 nfs_update_delegation_cred(struct nfs_delegation *delegation,
398 const struct cred *cred)
399 {
400 const struct cred *old;
401
402 if (cred_fscmp(delegation->cred, cred) != 0) {
403 old = xchg(&delegation->cred, get_cred(cred));
404 put_cred(old);
405 }
406 }
407
408 static void
nfs_update_inplace_delegation(struct nfs_delegation * delegation,const struct nfs_delegation * update)409 nfs_update_inplace_delegation(struct nfs_delegation *delegation,
410 const struct nfs_delegation *update)
411 {
412 if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) {
413 delegation->stateid.seqid = update->stateid.seqid;
414 smp_wmb();
415 delegation->type = update->type;
416 delegation->pagemod_limit = update->pagemod_limit;
417 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
418 delegation->change_attr = update->change_attr;
419 nfs_update_delegation_cred(delegation, update->cred);
420 /* smp_mb__before_atomic() is implicit due to xchg() */
421 clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
422 atomic_long_inc(&nfs_active_delegations);
423 }
424 }
425 }
426
427 /**
428 * nfs_inode_set_delegation - set up a delegation on an inode
429 * @inode: inode to which delegation applies
430 * @cred: cred to use for subsequent delegation processing
431 * @type: delegation type
432 * @stateid: delegation stateid
433 * @pagemod_limit: write delegation "space_limit"
434 * @deleg_type: raw delegation type
435 *
436 * Returns zero on success, or a negative errno value.
437 */
nfs_inode_set_delegation(struct inode * inode,const struct cred * cred,fmode_t type,const nfs4_stateid * stateid,unsigned long pagemod_limit,u32 deleg_type)438 int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
439 fmode_t type, const nfs4_stateid *stateid,
440 unsigned long pagemod_limit, u32 deleg_type)
441 {
442 struct nfs_server *server = NFS_SERVER(inode);
443 struct nfs_client *clp = server->nfs_client;
444 struct nfs_inode *nfsi = NFS_I(inode);
445 struct nfs_delegation *delegation, *old_delegation;
446 struct nfs_delegation *freeme = NULL;
447 int status = 0;
448
449 delegation = kmalloc(sizeof(*delegation), GFP_KERNEL_ACCOUNT);
450 if (delegation == NULL)
451 return -ENOMEM;
452 nfs4_stateid_copy(&delegation->stateid, stateid);
453 refcount_set(&delegation->refcount, 1);
454 delegation->type = type;
455 delegation->pagemod_limit = pagemod_limit;
456 delegation->change_attr = inode_peek_iversion_raw(inode);
457 delegation->cred = get_cred(cred);
458 delegation->inode = inode;
459 delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
460 switch (deleg_type) {
461 case NFS4_OPEN_DELEGATE_READ_ATTRS_DELEG:
462 case NFS4_OPEN_DELEGATE_WRITE_ATTRS_DELEG:
463 delegation->flags |= BIT(NFS_DELEGATION_DELEGTIME);
464 }
465 delegation->test_gen = 0;
466 spin_lock_init(&delegation->lock);
467
468 spin_lock(&clp->cl_lock);
469 old_delegation = rcu_dereference_protected(nfsi->delegation,
470 lockdep_is_held(&clp->cl_lock));
471 if (old_delegation == NULL)
472 goto add_new;
473 /* Is this an update of the existing delegation? */
474 if (nfs4_stateid_match_other(&old_delegation->stateid,
475 &delegation->stateid)) {
476 spin_lock(&old_delegation->lock);
477 nfs_update_inplace_delegation(old_delegation,
478 delegation);
479 spin_unlock(&old_delegation->lock);
480 goto out;
481 }
482 if (!test_bit(NFS_DELEGATION_REVOKED, &old_delegation->flags)) {
483 /*
484 * Deal with broken servers that hand out two
485 * delegations for the same file.
486 * Allow for upgrades to a WRITE delegation, but
487 * nothing else.
488 */
489 dfprintk(FILE, "%s: server %s handed out "
490 "a duplicate delegation!\n",
491 __func__, clp->cl_hostname);
492 if (delegation->type == old_delegation->type ||
493 !(delegation->type & FMODE_WRITE)) {
494 freeme = delegation;
495 delegation = NULL;
496 goto out;
497 }
498 if (test_and_set_bit(NFS_DELEGATION_RETURNING,
499 &old_delegation->flags))
500 goto out;
501 }
502 freeme = nfs_detach_delegation_locked(nfsi, old_delegation, clp);
503 if (freeme == NULL)
504 goto out;
505 add_new:
506 /*
507 * If we didn't revalidate the change attribute before setting
508 * the delegation, then pre-emptively ask for a full attribute
509 * cache revalidation.
510 */
511 spin_lock(&inode->i_lock);
512 if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_CHANGE)
513 nfs_set_cache_invalid(inode,
514 NFS_INO_INVALID_ATIME | NFS_INO_INVALID_CTIME |
515 NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE |
516 NFS_INO_INVALID_BLOCKS | NFS_INO_INVALID_NLINK |
517 NFS_INO_INVALID_OTHER | NFS_INO_INVALID_DATA |
518 NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL |
519 NFS_INO_INVALID_XATTR);
520 spin_unlock(&inode->i_lock);
521
522 list_add_tail_rcu(&delegation->super_list, &server->delegations);
523 rcu_assign_pointer(nfsi->delegation, delegation);
524 delegation = NULL;
525
526 atomic_long_inc(&nfs_active_delegations);
527
528 trace_nfs4_set_delegation(inode, type);
529
530 /* If we hold writebacks and have delegated mtime then update */
531 if (deleg_type == NFS4_OPEN_DELEGATE_WRITE_ATTRS_DELEG &&
532 nfs_have_writebacks(inode))
533 nfs_update_delegated_mtime(inode);
534 out:
535 spin_unlock(&clp->cl_lock);
536 if (delegation != NULL)
537 __nfs_free_delegation(delegation);
538 if (freeme != NULL) {
539 nfs_do_return_delegation(inode, freeme, 0);
540 nfs_free_delegation(freeme);
541 }
542 return status;
543 }
544
545 /*
546 * Basic procedure for returning a delegation to the server
547 */
nfs_end_delegation_return(struct inode * inode,struct nfs_delegation * delegation,int issync)548 static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
549 {
550 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
551 unsigned int mode = O_WRONLY | O_RDWR;
552 int err = 0;
553
554 if (delegation == NULL)
555 return 0;
556
557 if (!issync)
558 mode |= O_NONBLOCK;
559 /* Recall of any remaining application leases */
560 err = break_lease(inode, mode);
561
562 while (err == 0) {
563 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
564 break;
565 err = nfs_delegation_claim_opens(inode, &delegation->stateid,
566 delegation->type);
567 if (!issync || err != -EAGAIN)
568 break;
569 /*
570 * Guard against state recovery
571 */
572 err = nfs4_wait_clnt_recover(clp);
573 }
574
575 if (err) {
576 nfs_abort_delegation_return(delegation, clp, err);
577 goto out;
578 }
579
580 err = nfs_do_return_delegation(inode, delegation, issync);
581 out:
582 /* Refcount matched in nfs_start_delegation_return_locked() */
583 nfs_put_delegation(delegation);
584 return err;
585 }
586
nfs_delegation_need_return(struct nfs_delegation * delegation)587 static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
588 {
589 bool ret = false;
590
591 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
592 ret = true;
593 else if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags)) {
594 struct inode *inode;
595
596 spin_lock(&delegation->lock);
597 inode = delegation->inode;
598 if (inode && list_empty(&NFS_I(inode)->open_files))
599 ret = true;
600 spin_unlock(&delegation->lock);
601 }
602 if (ret)
603 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
604 if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags) ||
605 test_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags) ||
606 test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
607 ret = false;
608
609 return ret;
610 }
611
nfs_server_return_marked_delegations(struct nfs_server * server,void __always_unused * data)612 static int nfs_server_return_marked_delegations(struct nfs_server *server,
613 void __always_unused *data)
614 {
615 struct nfs_delegation *delegation;
616 struct nfs_delegation *prev;
617 struct inode *inode;
618 struct inode *place_holder = NULL;
619 struct nfs_delegation *place_holder_deleg = NULL;
620 int err = 0;
621
622 restart:
623 /*
624 * To avoid quadratic looping we hold a reference
625 * to an inode place_holder. Each time we restart, we
626 * list delegation in the server from the delegations
627 * of that inode.
628 * prev is an RCU-protected pointer to a delegation which
629 * wasn't marked for return and might be a good choice for
630 * the next place_holder.
631 */
632 prev = NULL;
633 delegation = NULL;
634 rcu_read_lock();
635 if (place_holder)
636 delegation = rcu_dereference(NFS_I(place_holder)->delegation);
637 if (!delegation || delegation != place_holder_deleg)
638 delegation = list_entry_rcu(server->delegations.next,
639 struct nfs_delegation, super_list);
640 list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) {
641 struct inode *to_put = NULL;
642
643 if (test_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags))
644 continue;
645 if (!nfs_delegation_need_return(delegation)) {
646 if (nfs4_is_valid_delegation(delegation, 0))
647 prev = delegation;
648 continue;
649 }
650
651 if (prev) {
652 struct inode *tmp = nfs_delegation_grab_inode(prev);
653 if (tmp) {
654 to_put = place_holder;
655 place_holder = tmp;
656 place_holder_deleg = prev;
657 }
658 }
659
660 inode = nfs_delegation_grab_inode(delegation);
661 if (inode == NULL) {
662 rcu_read_unlock();
663 iput(to_put);
664 goto restart;
665 }
666 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
667 rcu_read_unlock();
668
669 iput(to_put);
670
671 err = nfs_end_delegation_return(inode, delegation, 0);
672 iput(inode);
673 cond_resched();
674 if (!err)
675 goto restart;
676 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
677 goto out;
678 }
679 rcu_read_unlock();
680 out:
681 iput(place_holder);
682 return err;
683 }
684
nfs_server_clear_delayed_delegations(struct nfs_server * server)685 static bool nfs_server_clear_delayed_delegations(struct nfs_server *server)
686 {
687 struct nfs_delegation *d;
688 bool ret = false;
689
690 list_for_each_entry_rcu (d, &server->delegations, super_list) {
691 if (!test_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags))
692 continue;
693 nfs_mark_return_delegation(server, d);
694 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags);
695 ret = true;
696 }
697 return ret;
698 }
699
nfs_client_clear_delayed_delegations(struct nfs_client * clp)700 static bool nfs_client_clear_delayed_delegations(struct nfs_client *clp)
701 {
702 struct nfs_server *server;
703 bool ret = false;
704
705 if (!test_and_clear_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state))
706 goto out;
707 rcu_read_lock();
708 list_for_each_entry_rcu (server, &clp->cl_superblocks, client_link) {
709 if (nfs_server_clear_delayed_delegations(server))
710 ret = true;
711 }
712 rcu_read_unlock();
713 out:
714 return ret;
715 }
716
717 /**
718 * nfs_client_return_marked_delegations - return previously marked delegations
719 * @clp: nfs_client to process
720 *
721 * Note that this function is designed to be called by the state
722 * manager thread. For this reason, it cannot flush the dirty data,
723 * since that could deadlock in case of a state recovery error.
724 *
725 * Returns zero on success, or a negative errno value.
726 */
nfs_client_return_marked_delegations(struct nfs_client * clp)727 int nfs_client_return_marked_delegations(struct nfs_client *clp)
728 {
729 int err = nfs_client_for_each_server(
730 clp, nfs_server_return_marked_delegations, NULL);
731 if (err)
732 return err;
733 /* If a return was delayed, sleep to prevent hard looping */
734 if (nfs_client_clear_delayed_delegations(clp))
735 ssleep(1);
736 return 0;
737 }
738
739 /**
740 * nfs_inode_evict_delegation - return delegation, don't reclaim opens
741 * @inode: inode to process
742 *
743 * Does not protect against delegation reclaims, therefore really only safe
744 * to be called from nfs4_clear_inode(). Guaranteed to always free
745 * the delegation structure.
746 */
nfs_inode_evict_delegation(struct inode * inode)747 void nfs_inode_evict_delegation(struct inode *inode)
748 {
749 struct nfs_delegation *delegation;
750
751 delegation = nfs_inode_detach_delegation(inode);
752 if (delegation != NULL) {
753 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
754 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags);
755 nfs_do_return_delegation(inode, delegation, 1);
756 nfs_free_delegation(delegation);
757 }
758 }
759
760 /**
761 * nfs4_inode_return_delegation - synchronously return a delegation
762 * @inode: inode to process
763 *
764 * This routine will always flush any dirty data to disk on the
765 * assumption that if we need to return the delegation, then
766 * we should stop caching.
767 *
768 * Returns zero on success, or a negative errno value.
769 */
nfs4_inode_return_delegation(struct inode * inode)770 int nfs4_inode_return_delegation(struct inode *inode)
771 {
772 struct nfs_inode *nfsi = NFS_I(inode);
773 struct nfs_delegation *delegation;
774
775 delegation = nfs_start_delegation_return(nfsi);
776 if (delegation != NULL) {
777 /* Synchronous recall of any application leases */
778 break_lease(inode, O_WRONLY | O_RDWR);
779 if (S_ISREG(inode->i_mode))
780 nfs_wb_all(inode);
781 return nfs_end_delegation_return(inode, delegation, 1);
782 }
783 return 0;
784 }
785
786 /**
787 * nfs4_inode_return_delegation_on_close - asynchronously return a delegation
788 * @inode: inode to process
789 *
790 * This routine is called on file close in order to determine if the
791 * inode delegation needs to be returned immediately.
792 */
nfs4_inode_return_delegation_on_close(struct inode * inode)793 void nfs4_inode_return_delegation_on_close(struct inode *inode)
794 {
795 struct nfs_delegation *delegation;
796 struct nfs_delegation *ret = NULL;
797
798 if (!inode)
799 return;
800 rcu_read_lock();
801 delegation = nfs4_get_valid_delegation(inode);
802 if (!delegation)
803 goto out;
804 if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) ||
805 atomic_long_read(&nfs_active_delegations) >= nfs_delegation_watermark) {
806 spin_lock(&delegation->lock);
807 if (delegation->inode &&
808 list_empty(&NFS_I(inode)->open_files) &&
809 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
810 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
811 /* Refcount matched in nfs_end_delegation_return() */
812 ret = nfs_get_delegation(delegation);
813 }
814 spin_unlock(&delegation->lock);
815 if (ret)
816 nfs_clear_verifier_delegated(inode);
817 }
818 out:
819 rcu_read_unlock();
820 nfs_end_delegation_return(inode, ret, 0);
821 }
822
823 /**
824 * nfs4_inode_make_writeable
825 * @inode: pointer to inode
826 *
827 * Make the inode writeable by returning the delegation if necessary
828 *
829 * Returns zero on success, or a negative errno value.
830 */
nfs4_inode_make_writeable(struct inode * inode)831 int nfs4_inode_make_writeable(struct inode *inode)
832 {
833 struct nfs_delegation *delegation;
834
835 rcu_read_lock();
836 delegation = nfs4_get_valid_delegation(inode);
837 if (delegation == NULL ||
838 (nfs4_has_session(NFS_SERVER(inode)->nfs_client) &&
839 (delegation->type & FMODE_WRITE))) {
840 rcu_read_unlock();
841 return 0;
842 }
843 rcu_read_unlock();
844 return nfs4_inode_return_delegation(inode);
845 }
846
nfs_mark_return_if_closed_delegation(struct nfs_server * server,struct nfs_delegation * delegation)847 static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
848 struct nfs_delegation *delegation)
849 {
850 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
851 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
852 }
853
nfs_server_mark_return_all_delegations(struct nfs_server * server)854 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
855 {
856 struct nfs_delegation *delegation;
857 bool ret = false;
858
859 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
860 nfs_mark_return_delegation(server, delegation);
861 ret = true;
862 }
863 return ret;
864 }
865
nfs_client_mark_return_all_delegations(struct nfs_client * clp)866 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
867 {
868 struct nfs_server *server;
869
870 rcu_read_lock();
871 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
872 nfs_server_mark_return_all_delegations(server);
873 rcu_read_unlock();
874 }
875
nfs_delegation_run_state_manager(struct nfs_client * clp)876 static void nfs_delegation_run_state_manager(struct nfs_client *clp)
877 {
878 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
879 nfs4_schedule_state_manager(clp);
880 }
881
882 /**
883 * nfs_expire_all_delegations
884 * @clp: client to process
885 *
886 */
nfs_expire_all_delegations(struct nfs_client * clp)887 void nfs_expire_all_delegations(struct nfs_client *clp)
888 {
889 nfs_client_mark_return_all_delegations(clp);
890 nfs_delegation_run_state_manager(clp);
891 }
892
893 /**
894 * nfs_server_return_all_delegations - return delegations for one superblock
895 * @server: pointer to nfs_server to process
896 *
897 */
nfs_server_return_all_delegations(struct nfs_server * server)898 void nfs_server_return_all_delegations(struct nfs_server *server)
899 {
900 struct nfs_client *clp = server->nfs_client;
901 bool need_wait;
902
903 if (clp == NULL)
904 return;
905
906 rcu_read_lock();
907 need_wait = nfs_server_mark_return_all_delegations(server);
908 rcu_read_unlock();
909
910 if (need_wait) {
911 nfs4_schedule_state_manager(clp);
912 nfs4_wait_clnt_recover(clp);
913 }
914 }
915
nfs_mark_return_unused_delegation_types(struct nfs_server * server,fmode_t flags)916 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server,
917 fmode_t flags)
918 {
919 struct nfs_delegation *delegation;
920
921 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
922 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
923 continue;
924 if (delegation->type & flags)
925 nfs_mark_return_if_closed_delegation(server, delegation);
926 }
927 }
928
nfs_client_mark_return_unused_delegation_types(struct nfs_client * clp,fmode_t flags)929 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp,
930 fmode_t flags)
931 {
932 struct nfs_server *server;
933
934 rcu_read_lock();
935 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
936 nfs_mark_return_unused_delegation_types(server, flags);
937 rcu_read_unlock();
938 }
939
nfs_revoke_delegation(struct inode * inode,const nfs4_stateid * stateid)940 static void nfs_revoke_delegation(struct inode *inode,
941 const nfs4_stateid *stateid)
942 {
943 struct nfs_delegation *delegation;
944 nfs4_stateid tmp;
945 bool ret = false;
946
947 rcu_read_lock();
948 delegation = rcu_dereference(NFS_I(inode)->delegation);
949 if (delegation == NULL)
950 goto out;
951 if (stateid == NULL) {
952 nfs4_stateid_copy(&tmp, &delegation->stateid);
953 stateid = &tmp;
954 } else {
955 if (!nfs4_stateid_match_other(stateid, &delegation->stateid))
956 goto out;
957 spin_lock(&delegation->lock);
958 if (stateid->seqid) {
959 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) {
960 spin_unlock(&delegation->lock);
961 goto out;
962 }
963 delegation->stateid.seqid = stateid->seqid;
964 }
965 spin_unlock(&delegation->lock);
966 }
967 nfs_mark_delegation_revoked(delegation);
968 ret = true;
969 out:
970 rcu_read_unlock();
971 if (ret)
972 nfs_inode_find_state_and_recover(inode, stateid);
973 }
974
nfs_remove_bad_delegation(struct inode * inode,const nfs4_stateid * stateid)975 void nfs_remove_bad_delegation(struct inode *inode,
976 const nfs4_stateid *stateid)
977 {
978 nfs_revoke_delegation(inode, stateid);
979 }
980 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);
981
nfs_delegation_mark_returned(struct inode * inode,const nfs4_stateid * stateid)982 void nfs_delegation_mark_returned(struct inode *inode,
983 const nfs4_stateid *stateid)
984 {
985 struct nfs_delegation *delegation;
986
987 if (!inode)
988 return;
989
990 rcu_read_lock();
991 delegation = rcu_dereference(NFS_I(inode)->delegation);
992 if (!delegation)
993 goto out_rcu_unlock;
994
995 spin_lock(&delegation->lock);
996 if (!nfs4_stateid_match_other(stateid, &delegation->stateid))
997 goto out_spin_unlock;
998 if (stateid->seqid) {
999 /* If delegation->stateid is newer, dont mark as returned */
1000 if (nfs4_stateid_is_newer(&delegation->stateid, stateid))
1001 goto out_clear_returning;
1002 if (delegation->stateid.seqid != stateid->seqid)
1003 delegation->stateid.seqid = stateid->seqid;
1004 }
1005
1006 nfs_mark_delegation_revoked(delegation);
1007
1008 out_clear_returning:
1009 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
1010 out_spin_unlock:
1011 spin_unlock(&delegation->lock);
1012 out_rcu_unlock:
1013 rcu_read_unlock();
1014
1015 nfs_inode_find_state_and_recover(inode, stateid);
1016 }
1017
1018 /**
1019 * nfs_expire_unused_delegation_types
1020 * @clp: client to process
1021 * @flags: delegation types to expire
1022 *
1023 */
nfs_expire_unused_delegation_types(struct nfs_client * clp,fmode_t flags)1024 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags)
1025 {
1026 nfs_client_mark_return_unused_delegation_types(clp, flags);
1027 nfs_delegation_run_state_manager(clp);
1028 }
1029
nfs_mark_return_unreferenced_delegations(struct nfs_server * server)1030 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
1031 {
1032 struct nfs_delegation *delegation;
1033
1034 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1035 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
1036 continue;
1037 nfs_mark_return_if_closed_delegation(server, delegation);
1038 }
1039 }
1040
1041 /**
1042 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
1043 * @clp: nfs_client to process
1044 *
1045 */
nfs_expire_unreferenced_delegations(struct nfs_client * clp)1046 void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
1047 {
1048 struct nfs_server *server;
1049
1050 rcu_read_lock();
1051 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1052 nfs_mark_return_unreferenced_delegations(server);
1053 rcu_read_unlock();
1054
1055 nfs_delegation_run_state_manager(clp);
1056 }
1057
1058 /**
1059 * nfs_async_inode_return_delegation - asynchronously return a delegation
1060 * @inode: inode to process
1061 * @stateid: state ID information
1062 *
1063 * Returns zero on success, or a negative errno value.
1064 */
nfs_async_inode_return_delegation(struct inode * inode,const nfs4_stateid * stateid)1065 int nfs_async_inode_return_delegation(struct inode *inode,
1066 const nfs4_stateid *stateid)
1067 {
1068 struct nfs_server *server = NFS_SERVER(inode);
1069 struct nfs_client *clp = server->nfs_client;
1070 struct nfs_delegation *delegation;
1071
1072 rcu_read_lock();
1073 delegation = nfs4_get_valid_delegation(inode);
1074 if (delegation == NULL)
1075 goto out_enoent;
1076 if (stateid != NULL &&
1077 !clp->cl_mvops->match_stateid(&delegation->stateid, stateid))
1078 goto out_enoent;
1079 nfs_mark_return_delegation(server, delegation);
1080 rcu_read_unlock();
1081
1082 /* If there are any application leases or delegations, recall them */
1083 break_lease(inode, O_WRONLY | O_RDWR | O_NONBLOCK);
1084
1085 nfs_delegation_run_state_manager(clp);
1086 return 0;
1087 out_enoent:
1088 rcu_read_unlock();
1089 return -ENOENT;
1090 }
1091
1092 static struct inode *
nfs_delegation_find_inode_server(struct nfs_server * server,const struct nfs_fh * fhandle)1093 nfs_delegation_find_inode_server(struct nfs_server *server,
1094 const struct nfs_fh *fhandle)
1095 {
1096 struct nfs_delegation *delegation;
1097 struct super_block *freeme = NULL;
1098 struct inode *res = NULL;
1099
1100 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1101 spin_lock(&delegation->lock);
1102 if (delegation->inode != NULL &&
1103 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
1104 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
1105 if (nfs_sb_active(server->super)) {
1106 freeme = server->super;
1107 res = igrab(delegation->inode);
1108 }
1109 spin_unlock(&delegation->lock);
1110 if (res != NULL)
1111 return res;
1112 if (freeme) {
1113 rcu_read_unlock();
1114 nfs_sb_deactive(freeme);
1115 rcu_read_lock();
1116 }
1117 return ERR_PTR(-EAGAIN);
1118 }
1119 spin_unlock(&delegation->lock);
1120 }
1121 return ERR_PTR(-ENOENT);
1122 }
1123
1124 /**
1125 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
1126 * @clp: client state handle
1127 * @fhandle: filehandle from a delegation recall
1128 *
1129 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
1130 * cannot be found.
1131 */
nfs_delegation_find_inode(struct nfs_client * clp,const struct nfs_fh * fhandle)1132 struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
1133 const struct nfs_fh *fhandle)
1134 {
1135 struct nfs_server *server;
1136 struct inode *res;
1137
1138 rcu_read_lock();
1139 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1140 res = nfs_delegation_find_inode_server(server, fhandle);
1141 if (res != ERR_PTR(-ENOENT)) {
1142 rcu_read_unlock();
1143 return res;
1144 }
1145 }
1146 rcu_read_unlock();
1147 return ERR_PTR(-ENOENT);
1148 }
1149
nfs_delegation_mark_reclaim_server(struct nfs_server * server)1150 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
1151 {
1152 struct nfs_delegation *delegation;
1153
1154 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1155 /*
1156 * If the delegation may have been admin revoked, then we
1157 * cannot reclaim it.
1158 */
1159 if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags))
1160 continue;
1161 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
1162 }
1163 }
1164
1165 /**
1166 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
1167 * @clp: nfs_client to process
1168 *
1169 */
nfs_delegation_mark_reclaim(struct nfs_client * clp)1170 void nfs_delegation_mark_reclaim(struct nfs_client *clp)
1171 {
1172 struct nfs_server *server;
1173
1174 rcu_read_lock();
1175 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1176 nfs_delegation_mark_reclaim_server(server);
1177 rcu_read_unlock();
1178 }
1179
nfs_server_reap_unclaimed_delegations(struct nfs_server * server,void __always_unused * data)1180 static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server,
1181 void __always_unused *data)
1182 {
1183 struct nfs_delegation *delegation;
1184 struct inode *inode;
1185 restart:
1186 rcu_read_lock();
1187 restart_locked:
1188 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1189 if (test_bit(NFS_DELEGATION_INODE_FREEING,
1190 &delegation->flags) ||
1191 test_bit(NFS_DELEGATION_RETURNING,
1192 &delegation->flags) ||
1193 test_bit(NFS_DELEGATION_NEED_RECLAIM,
1194 &delegation->flags) == 0)
1195 continue;
1196 inode = nfs_delegation_grab_inode(delegation);
1197 if (inode == NULL)
1198 goto restart_locked;
1199 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
1200 rcu_read_unlock();
1201 if (delegation != NULL) {
1202 if (nfs_detach_delegation(NFS_I(inode), delegation,
1203 server) != NULL)
1204 nfs_free_delegation(delegation);
1205 /* Match nfs_start_delegation_return_locked */
1206 nfs_put_delegation(delegation);
1207 }
1208 iput(inode);
1209 cond_resched();
1210 goto restart;
1211 }
1212 rcu_read_unlock();
1213 return 0;
1214 }
1215
1216 /**
1217 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
1218 * @clp: nfs_client to process
1219 *
1220 */
nfs_delegation_reap_unclaimed(struct nfs_client * clp)1221 void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
1222 {
1223 nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations,
1224 NULL);
1225 }
1226
nfs4_server_rebooted(const struct nfs_client * clp)1227 static inline bool nfs4_server_rebooted(const struct nfs_client *clp)
1228 {
1229 return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) |
1230 BIT(NFS4CLNT_LEASE_EXPIRED) |
1231 BIT(NFS4CLNT_SESSION_RESET))) != 0;
1232 }
1233
nfs_mark_test_expired_delegation(struct nfs_server * server,struct nfs_delegation * delegation)1234 static void nfs_mark_test_expired_delegation(struct nfs_server *server,
1235 struct nfs_delegation *delegation)
1236 {
1237 if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE)
1238 return;
1239 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
1240 set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
1241 set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state);
1242 }
1243
nfs_inode_mark_test_expired_delegation(struct nfs_server * server,struct inode * inode)1244 static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server,
1245 struct inode *inode)
1246 {
1247 struct nfs_delegation *delegation;
1248
1249 rcu_read_lock();
1250 delegation = rcu_dereference(NFS_I(inode)->delegation);
1251 if (delegation)
1252 nfs_mark_test_expired_delegation(server, delegation);
1253 rcu_read_unlock();
1254
1255 }
1256
nfs_delegation_mark_test_expired_server(struct nfs_server * server)1257 static void nfs_delegation_mark_test_expired_server(struct nfs_server *server)
1258 {
1259 struct nfs_delegation *delegation;
1260
1261 list_for_each_entry_rcu(delegation, &server->delegations, super_list)
1262 nfs_mark_test_expired_delegation(server, delegation);
1263 }
1264
1265 /**
1266 * nfs_mark_test_expired_all_delegations - mark all delegations for testing
1267 * @clp: nfs_client to process
1268 *
1269 * Iterates through all the delegations associated with this server and
1270 * marks them as needing to be checked for validity.
1271 */
nfs_mark_test_expired_all_delegations(struct nfs_client * clp)1272 void nfs_mark_test_expired_all_delegations(struct nfs_client *clp)
1273 {
1274 struct nfs_server *server;
1275
1276 rcu_read_lock();
1277 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1278 nfs_delegation_mark_test_expired_server(server);
1279 rcu_read_unlock();
1280 }
1281
1282 /**
1283 * nfs_test_expired_all_delegations - test all delegations for a client
1284 * @clp: nfs_client to process
1285 *
1286 * Helper for handling "recallable state revoked" status from server.
1287 */
nfs_test_expired_all_delegations(struct nfs_client * clp)1288 void nfs_test_expired_all_delegations(struct nfs_client *clp)
1289 {
1290 nfs_mark_test_expired_all_delegations(clp);
1291 nfs4_schedule_state_manager(clp);
1292 }
1293
1294 static void
nfs_delegation_test_free_expired(struct inode * inode,nfs4_stateid * stateid,const struct cred * cred)1295 nfs_delegation_test_free_expired(struct inode *inode,
1296 nfs4_stateid *stateid,
1297 const struct cred *cred)
1298 {
1299 struct nfs_server *server = NFS_SERVER(inode);
1300 const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops;
1301 int status;
1302
1303 if (!cred)
1304 return;
1305 status = ops->test_and_free_expired(server, stateid, cred);
1306 if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID)
1307 nfs_remove_bad_delegation(inode, stateid);
1308 }
1309
nfs_server_reap_expired_delegations(struct nfs_server * server,void __always_unused * data)1310 static int nfs_server_reap_expired_delegations(struct nfs_server *server,
1311 void __always_unused *data)
1312 {
1313 struct nfs_delegation *delegation;
1314 struct inode *inode;
1315 const struct cred *cred;
1316 nfs4_stateid stateid;
1317 unsigned long gen = ++server->delegation_gen;
1318
1319 restart:
1320 rcu_read_lock();
1321 restart_locked:
1322 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1323 if (test_bit(NFS_DELEGATION_INODE_FREEING,
1324 &delegation->flags) ||
1325 test_bit(NFS_DELEGATION_RETURNING,
1326 &delegation->flags) ||
1327 test_bit(NFS_DELEGATION_TEST_EXPIRED,
1328 &delegation->flags) == 0 ||
1329 delegation->test_gen == gen)
1330 continue;
1331 inode = nfs_delegation_grab_inode(delegation);
1332 if (inode == NULL)
1333 goto restart_locked;
1334 spin_lock(&delegation->lock);
1335 cred = get_cred_rcu(delegation->cred);
1336 nfs4_stateid_copy(&stateid, &delegation->stateid);
1337 spin_unlock(&delegation->lock);
1338 delegation->test_gen = gen;
1339 clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
1340 rcu_read_unlock();
1341 nfs_delegation_test_free_expired(inode, &stateid, cred);
1342 put_cred(cred);
1343 if (!nfs4_server_rebooted(server->nfs_client)) {
1344 iput(inode);
1345 cond_resched();
1346 goto restart;
1347 }
1348 nfs_inode_mark_test_expired_delegation(server,inode);
1349 iput(inode);
1350 return -EAGAIN;
1351 }
1352 rcu_read_unlock();
1353 return 0;
1354 }
1355
1356 /**
1357 * nfs_reap_expired_delegations - reap expired delegations
1358 * @clp: nfs_client to process
1359 *
1360 * Iterates through all the delegations associated with this server and
1361 * checks if they have may have been revoked. This function is usually
1362 * expected to be called in cases where the server may have lost its
1363 * lease.
1364 */
nfs_reap_expired_delegations(struct nfs_client * clp)1365 void nfs_reap_expired_delegations(struct nfs_client *clp)
1366 {
1367 nfs_client_for_each_server(clp, nfs_server_reap_expired_delegations,
1368 NULL);
1369 }
1370
nfs_inode_find_delegation_state_and_recover(struct inode * inode,const nfs4_stateid * stateid)1371 void nfs_inode_find_delegation_state_and_recover(struct inode *inode,
1372 const nfs4_stateid *stateid)
1373 {
1374 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1375 struct nfs_delegation *delegation;
1376 bool found = false;
1377
1378 rcu_read_lock();
1379 delegation = rcu_dereference(NFS_I(inode)->delegation);
1380 if (delegation &&
1381 nfs4_stateid_match_or_older(&delegation->stateid, stateid) &&
1382 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
1383 nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation);
1384 found = true;
1385 }
1386 rcu_read_unlock();
1387 if (found)
1388 nfs4_schedule_state_manager(clp);
1389 }
1390
1391 /**
1392 * nfs_delegations_present - check for existence of delegations
1393 * @clp: client state handle
1394 *
1395 * Returns one if there are any nfs_delegation structures attached
1396 * to this nfs_client.
1397 */
nfs_delegations_present(struct nfs_client * clp)1398 int nfs_delegations_present(struct nfs_client *clp)
1399 {
1400 struct nfs_server *server;
1401 int ret = 0;
1402
1403 rcu_read_lock();
1404 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1405 if (!list_empty(&server->delegations)) {
1406 ret = 1;
1407 break;
1408 }
1409 rcu_read_unlock();
1410 return ret;
1411 }
1412
1413 /**
1414 * nfs4_refresh_delegation_stateid - Update delegation stateid seqid
1415 * @dst: stateid to refresh
1416 * @inode: inode to check
1417 *
1418 * Returns "true" and updates "dst->seqid" * if inode had a delegation
1419 * that matches our delegation stateid. Otherwise "false" is returned.
1420 */
nfs4_refresh_delegation_stateid(nfs4_stateid * dst,struct inode * inode)1421 bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
1422 {
1423 struct nfs_delegation *delegation;
1424 bool ret = false;
1425 if (!inode)
1426 goto out;
1427
1428 rcu_read_lock();
1429 delegation = rcu_dereference(NFS_I(inode)->delegation);
1430 if (delegation != NULL &&
1431 nfs4_stateid_match_other(dst, &delegation->stateid) &&
1432 nfs4_stateid_is_newer(&delegation->stateid, dst) &&
1433 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
1434 dst->seqid = delegation->stateid.seqid;
1435 ret = true;
1436 }
1437 rcu_read_unlock();
1438 out:
1439 return ret;
1440 }
1441
1442 /**
1443 * nfs4_copy_delegation_stateid - Copy inode's state ID information
1444 * @inode: inode to check
1445 * @flags: delegation type requirement
1446 * @dst: stateid data structure to fill in
1447 * @cred: optional argument to retrieve credential
1448 *
1449 * Returns "true" and fills in "dst->data" * if inode had a delegation,
1450 * otherwise "false" is returned.
1451 */
nfs4_copy_delegation_stateid(struct inode * inode,fmode_t flags,nfs4_stateid * dst,const struct cred ** cred)1452 bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags,
1453 nfs4_stateid *dst, const struct cred **cred)
1454 {
1455 struct nfs_inode *nfsi = NFS_I(inode);
1456 struct nfs_delegation *delegation;
1457 bool ret = false;
1458
1459 flags &= FMODE_READ|FMODE_WRITE;
1460 rcu_read_lock();
1461 delegation = rcu_dereference(nfsi->delegation);
1462 if (!delegation)
1463 goto out;
1464 spin_lock(&delegation->lock);
1465 ret = nfs4_is_valid_delegation(delegation, flags);
1466 if (ret) {
1467 nfs4_stateid_copy(dst, &delegation->stateid);
1468 nfs_mark_delegation_referenced(delegation);
1469 if (cred)
1470 *cred = get_cred(delegation->cred);
1471 }
1472 spin_unlock(&delegation->lock);
1473 out:
1474 rcu_read_unlock();
1475 return ret;
1476 }
1477
1478 /**
1479 * nfs4_delegation_flush_on_close - Check if we must flush file on close
1480 * @inode: inode to check
1481 *
1482 * This function checks the number of outstanding writes to the file
1483 * against the delegation 'space_limit' field to see if
1484 * the spec requires us to flush the file on close.
1485 */
nfs4_delegation_flush_on_close(const struct inode * inode)1486 bool nfs4_delegation_flush_on_close(const struct inode *inode)
1487 {
1488 struct nfs_inode *nfsi = NFS_I(inode);
1489 struct nfs_delegation *delegation;
1490 bool ret = true;
1491
1492 rcu_read_lock();
1493 delegation = rcu_dereference(nfsi->delegation);
1494 if (delegation == NULL || !(delegation->type & FMODE_WRITE))
1495 goto out;
1496 if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit)
1497 ret = false;
1498 out:
1499 rcu_read_unlock();
1500 return ret;
1501 }
1502
1503 module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644);
1504