~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/nfs/delegation.c

Version: ~ [ linux-5.11 ] ~ [ linux-5.10.17 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.99 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.176 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.221 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.257 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.257 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * linux/fs/nfs/delegation.c
  3  *
  4  * Copyright (C) 2004 Trond Myklebust
  5  *
  6  * NFS file delegation management
  7  *
  8  */
  9 #include <linux/completion.h>
 10 #include <linux/kthread.h>
 11 #include <linux/module.h>
 12 #include <linux/sched.h>
 13 #include <linux/slab.h>
 14 #include <linux/spinlock.h>
 15 
 16 #include <linux/nfs4.h>
 17 #include <linux/nfs_fs.h>
 18 #include <linux/nfs_xdr.h>
 19 
 20 #include "nfs4_fs.h"
 21 #include "delegation.h"
 22 #include "internal.h"
 23 #include "nfs4trace.h"
 24 
 25 static void nfs_free_delegation(struct nfs_delegation *delegation)
 26 {
 27         if (delegation->cred) {
 28                 put_rpccred(delegation->cred);
 29                 delegation->cred = NULL;
 30         }
 31         kfree_rcu(delegation, rcu);
 32 }
 33 
 34 /**
 35  * nfs_mark_delegation_referenced - set delegation's REFERENCED flag
 36  * @delegation: delegation to process
 37  *
 38  */
 39 void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
 40 {
 41         set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
 42 }
 43 
 44 static bool
 45 nfs4_is_valid_delegation(const struct nfs_delegation *delegation,
 46                 fmode_t flags)
 47 {
 48         if (delegation != NULL && (delegation->type & flags) == flags &&
 49             !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
 50             !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
 51                 return true;
 52         return false;
 53 }
 54 
 55 static int
 56 nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark)
 57 {
 58         struct nfs_delegation *delegation;
 59         int ret = 0;
 60 
 61         flags &= FMODE_READ|FMODE_WRITE;
 62         rcu_read_lock();
 63         delegation = rcu_dereference(NFS_I(inode)->delegation);
 64         if (nfs4_is_valid_delegation(delegation, flags)) {
 65                 if (mark)
 66                         nfs_mark_delegation_referenced(delegation);
 67                 ret = 1;
 68         }
 69         rcu_read_unlock();
 70         return ret;
 71 }
 72 /**
 73  * nfs_have_delegation - check if inode has a delegation, mark it
 74  * NFS_DELEGATION_REFERENCED if there is one.
 75  * @inode: inode to check
 76  * @flags: delegation types to check for
 77  *
 78  * Returns one if inode has the indicated delegation, otherwise zero.
 79  */
 80 int nfs4_have_delegation(struct inode *inode, fmode_t flags)
 81 {
 82         return nfs4_do_check_delegation(inode, flags, true);
 83 }
 84 
 85 /*
 86  * nfs4_check_delegation - check if inode has a delegation, do not mark
 87  * NFS_DELEGATION_REFERENCED if it has one.
 88  */
 89 int nfs4_check_delegation(struct inode *inode, fmode_t flags)
 90 {
 91         return nfs4_do_check_delegation(inode, flags, false);
 92 }
 93 
 94 static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state, const nfs4_stateid *stateid)
 95 {
 96         struct inode *inode = state->inode;
 97         struct file_lock *fl;
 98         struct file_lock_context *flctx = inode->i_flctx;
 99         struct list_head *list;
100         int status = 0;
101 
102         if (flctx == NULL)
103                 goto out;
104 
105         list = &flctx->flc_posix;
106         spin_lock(&flctx->flc_lock);
107 restart:
108         list_for_each_entry(fl, list, fl_list) {
109                 if (nfs_file_open_context(fl->fl_file) != ctx)
110                         continue;
111                 spin_unlock(&flctx->flc_lock);
112                 status = nfs4_lock_delegation_recall(fl, state, stateid);
113                 if (status < 0)
114                         goto out;
115                 spin_lock(&flctx->flc_lock);
116         }
117         if (list == &flctx->flc_posix) {
118                 list = &flctx->flc_flock;
119                 goto restart;
120         }
121         spin_unlock(&flctx->flc_lock);
122 out:
123         return status;
124 }
125 
126 static int nfs_delegation_claim_opens(struct inode *inode,
127                 const nfs4_stateid *stateid, fmode_t type)
128 {
129         struct nfs_inode *nfsi = NFS_I(inode);
130         struct nfs_open_context *ctx;
131         struct nfs4_state_owner *sp;
132         struct nfs4_state *state;
133         unsigned int seq;
134         int err;
135 
136 again:
137         spin_lock(&inode->i_lock);
138         list_for_each_entry(ctx, &nfsi->open_files, list) {
139                 state = ctx->state;
140                 if (state == NULL)
141                         continue;
142                 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
143                         continue;
144                 if (!nfs4_valid_open_stateid(state))
145                         continue;
146                 if (!nfs4_stateid_match(&state->stateid, stateid))
147                         continue;
148                 get_nfs_open_context(ctx);
149                 spin_unlock(&inode->i_lock);
150                 sp = state->owner;
151                 /* Block nfs4_proc_unlck */
152                 mutex_lock(&sp->so_delegreturn_mutex);
153                 seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
154                 err = nfs4_open_delegation_recall(ctx, state, stateid, type);
155                 if (!err)
156                         err = nfs_delegation_claim_locks(ctx, state, stateid);
157                 if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
158                         err = -EAGAIN;
159                 mutex_unlock(&sp->so_delegreturn_mutex);
160                 put_nfs_open_context(ctx);
161                 if (err != 0)
162                         return err;
163                 goto again;
164         }
165         spin_unlock(&inode->i_lock);
166         return 0;
167 }
168 
169 /**
170  * nfs_inode_reclaim_delegation - process a delegation reclaim request
171  * @inode: inode to process
172  * @cred: credential to use for request
173  * @res: new delegation state from server
174  *
175  */
176 void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred,
177                                   struct nfs_openres *res)
178 {
179         struct nfs_delegation *delegation;
180         struct rpc_cred *oldcred = NULL;
181 
182         rcu_read_lock();
183         delegation = rcu_dereference(NFS_I(inode)->delegation);
184         if (delegation != NULL) {
185                 spin_lock(&delegation->lock);
186                 if (delegation->inode != NULL) {
187                         nfs4_stateid_copy(&delegation->stateid, &res->delegation);
188                         delegation->type = res->delegation_type;
189                         delegation->pagemod_limit = res->pagemod_limit;
190                         oldcred = delegation->cred;
191                         delegation->cred = get_rpccred(cred);
192                         clear_bit(NFS_DELEGATION_NEED_RECLAIM,
193                                   &delegation->flags);
194                         spin_unlock(&delegation->lock);
195                         rcu_read_unlock();
196                         put_rpccred(oldcred);
197                         trace_nfs4_reclaim_delegation(inode, res->delegation_type);
198                 } else {
199                         /* We appear to have raced with a delegation return. */
200                         spin_unlock(&delegation->lock);
201                         rcu_read_unlock();
202                         nfs_inode_set_delegation(inode, cred, res);
203                 }
204         } else {
205                 rcu_read_unlock();
206         }
207 }
208 
209 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
210 {
211         int res = 0;
212 
213         if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
214                 res = nfs4_proc_delegreturn(inode,
215                                 delegation->cred,
216                                 &delegation->stateid,
217                                 issync);
218         nfs_free_delegation(delegation);
219         return res;
220 }
221 
222 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
223 {
224         struct inode *inode = NULL;
225 
226         spin_lock(&delegation->lock);
227         if (delegation->inode != NULL)
228                 inode = igrab(delegation->inode);
229         spin_unlock(&delegation->lock);
230         return inode;
231 }
232 
233 static struct nfs_delegation *
234 nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
235 {
236         struct nfs_delegation *ret = NULL;
237         struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
238 
239         if (delegation == NULL)
240                 goto out;
241         spin_lock(&delegation->lock);
242         if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
243                 ret = delegation;
244         spin_unlock(&delegation->lock);
245 out:
246         return ret;
247 }
248 
249 static struct nfs_delegation *
250 nfs_start_delegation_return(struct nfs_inode *nfsi)
251 {
252         struct nfs_delegation *delegation;
253 
254         rcu_read_lock();
255         delegation = nfs_start_delegation_return_locked(nfsi);
256         rcu_read_unlock();
257         return delegation;
258 }
259 
260 static void
261 nfs_abort_delegation_return(struct nfs_delegation *delegation,
262                 struct nfs_client *clp)
263 {
264 
265         spin_lock(&delegation->lock);
266         clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
267         set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
268         spin_unlock(&delegation->lock);
269         set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
270 }
271 
272 static struct nfs_delegation *
273 nfs_detach_delegation_locked(struct nfs_inode *nfsi,
274                 struct nfs_delegation *delegation,
275                 struct nfs_client *clp)
276 {
277         struct nfs_delegation *deleg_cur =
278                 rcu_dereference_protected(nfsi->delegation,
279                                 lockdep_is_held(&clp->cl_lock));
280 
281         if (deleg_cur == NULL || delegation != deleg_cur)
282                 return NULL;
283 
284         spin_lock(&delegation->lock);
285         set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
286         list_del_rcu(&delegation->super_list);
287         delegation->inode = NULL;
288         rcu_assign_pointer(nfsi->delegation, NULL);
289         spin_unlock(&delegation->lock);
290         return delegation;
291 }
292 
293 static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
294                 struct nfs_delegation *delegation,
295                 struct nfs_server *server)
296 {
297         struct nfs_client *clp = server->nfs_client;
298 
299         spin_lock(&clp->cl_lock);
300         delegation = nfs_detach_delegation_locked(nfsi, delegation, clp);
301         spin_unlock(&clp->cl_lock);
302         return delegation;
303 }
304 
305 static struct nfs_delegation *
306 nfs_inode_detach_delegation(struct inode *inode)
307 {
308         struct nfs_inode *nfsi = NFS_I(inode);
309         struct nfs_server *server = NFS_SERVER(inode);
310         struct nfs_delegation *delegation;
311 
312         delegation = nfs_start_delegation_return(nfsi);
313         if (delegation == NULL)
314                 return NULL;
315         return nfs_detach_delegation(nfsi, delegation, server);
316 }
317 
318 static void
319 nfs_update_inplace_delegation(struct nfs_delegation *delegation,
320                 const struct nfs_delegation *update)
321 {
322         if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) {
323                 delegation->stateid.seqid = update->stateid.seqid;
324                 smp_wmb();
325                 delegation->type = update->type;
326         }
327 }
328 
329 /**
330  * nfs_inode_set_delegation - set up a delegation on an inode
331  * @inode: inode to which delegation applies
332  * @cred: cred to use for subsequent delegation processing
333  * @res: new delegation state from server
334  *
335  * Returns zero on success, or a negative errno value.
336  */
337 int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
338 {
339         struct nfs_server *server = NFS_SERVER(inode);
340         struct nfs_client *clp = server->nfs_client;
341         struct nfs_inode *nfsi = NFS_I(inode);
342         struct nfs_delegation *delegation, *old_delegation;
343         struct nfs_delegation *freeme = NULL;
344         int status = 0;
345 
346         delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
347         if (delegation == NULL)
348                 return -ENOMEM;
349         nfs4_stateid_copy(&delegation->stateid, &res->delegation);
350         delegation->type = res->delegation_type;
351         delegation->pagemod_limit = res->pagemod_limit;
352         delegation->change_attr = inode->i_version;
353         delegation->cred = get_rpccred(cred);
354         delegation->inode = inode;
355         delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
356         spin_lock_init(&delegation->lock);
357 
358         spin_lock(&clp->cl_lock);
359         old_delegation = rcu_dereference_protected(nfsi->delegation,
360                                         lockdep_is_held(&clp->cl_lock));
361         if (old_delegation != NULL) {
362                 /* Is this an update of the existing delegation? */
363                 if (nfs4_stateid_match_other(&old_delegation->stateid,
364                                         &delegation->stateid)) {
365                         nfs_update_inplace_delegation(old_delegation,
366                                         delegation);
367                         goto out;
368                 }
369                 /*
370                  * Deal with broken servers that hand out two
371                  * delegations for the same file.
372                  * Allow for upgrades to a WRITE delegation, but
373                  * nothing else.
374                  */
375                 dfprintk(FILE, "%s: server %s handed out "
376                                 "a duplicate delegation!\n",
377                                 __func__, clp->cl_hostname);
378                 if (delegation->type == old_delegation->type ||
379                     !(delegation->type & FMODE_WRITE)) {
380                         freeme = delegation;
381                         delegation = NULL;
382                         goto out;
383                 }
384                 if (test_and_set_bit(NFS_DELEGATION_RETURNING,
385                                         &old_delegation->flags))
386                         goto out;
387                 freeme = nfs_detach_delegation_locked(nfsi,
388                                 old_delegation, clp);
389                 if (freeme == NULL)
390                         goto out;
391         }
392         list_add_tail_rcu(&delegation->super_list, &server->delegations);
393         rcu_assign_pointer(nfsi->delegation, delegation);
394         delegation = NULL;
395 
396         /* Ensure we revalidate the attributes and page cache! */
397         spin_lock(&inode->i_lock);
398         nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
399         spin_unlock(&inode->i_lock);
400         trace_nfs4_set_delegation(inode, res->delegation_type);
401 
402 out:
403         spin_unlock(&clp->cl_lock);
404         if (delegation != NULL)
405                 nfs_free_delegation(delegation);
406         if (freeme != NULL)
407                 nfs_do_return_delegation(inode, freeme, 0);
408         return status;
409 }
410 
411 /*
412  * Basic procedure for returning a delegation to the server
413  */
414 static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
415 {
416         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
417         struct nfs_inode *nfsi = NFS_I(inode);
418         int err = 0;
419 
420         if (delegation == NULL)
421                 return 0;
422         do {
423                 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
424                         break;
425                 err = nfs_delegation_claim_opens(inode, &delegation->stateid,
426                                 delegation->type);
427                 if (!issync || err != -EAGAIN)
428                         break;
429                 /*
430                  * Guard against state recovery
431                  */
432                 err = nfs4_wait_clnt_recover(clp);
433         } while (err == 0);
434 
435         if (err) {
436                 nfs_abort_delegation_return(delegation, clp);
437                 goto out;
438         }
439         if (!nfs_detach_delegation(nfsi, delegation, NFS_SERVER(inode)))
440                 goto out;
441 
442         err = nfs_do_return_delegation(inode, delegation, issync);
443 out:
444         return err;
445 }
446 
447 static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
448 {
449         bool ret = false;
450 
451         if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
452                 goto out;
453         if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
454                 ret = true;
455         if (test_and_clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) && !ret) {
456                 struct inode *inode;
457 
458                 spin_lock(&delegation->lock);
459                 inode = delegation->inode;
460                 if (inode && list_empty(&NFS_I(inode)->open_files))
461                         ret = true;
462                 spin_unlock(&delegation->lock);
463         }
464 out:
465         return ret;
466 }
467 
468 /**
469  * nfs_client_return_marked_delegations - return previously marked delegations
470  * @clp: nfs_client to process
471  *
472  * Note that this function is designed to be called by the state
473  * manager thread. For this reason, it cannot flush the dirty data,
474  * since that could deadlock in case of a state recovery error.
475  *
476  * Returns zero on success, or a negative errno value.
477  */
478 int nfs_client_return_marked_delegations(struct nfs_client *clp)
479 {
480         struct nfs_delegation *delegation;
481         struct nfs_server *server;
482         struct inode *inode;
483         int err = 0;
484 
485 restart:
486         rcu_read_lock();
487         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
488                 list_for_each_entry_rcu(delegation, &server->delegations,
489                                                                 super_list) {
490                         if (!nfs_delegation_need_return(delegation))
491                                 continue;
492                         if (!nfs_sb_active(server->super))
493                                 continue;
494                         inode = nfs_delegation_grab_inode(delegation);
495                         if (inode == NULL) {
496                                 rcu_read_unlock();
497                                 nfs_sb_deactive(server->super);
498                                 goto restart;
499                         }
500                         delegation = nfs_start_delegation_return_locked(NFS_I(inode));
501                         rcu_read_unlock();
502 
503                         err = nfs_end_delegation_return(inode, delegation, 0);
504                         iput(inode);
505                         nfs_sb_deactive(server->super);
506                         if (!err)
507                                 goto restart;
508                         set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
509                         return err;
510                 }
511         }
512         rcu_read_unlock();
513         return 0;
514 }
515 
516 /**
517  * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
518  * @inode: inode to process
519  *
520  * Does not protect against delegation reclaims, therefore really only safe
521  * to be called from nfs4_clear_inode().
522  */
523 void nfs_inode_return_delegation_noreclaim(struct inode *inode)
524 {
525         struct nfs_delegation *delegation;
526 
527         delegation = nfs_inode_detach_delegation(inode);
528         if (delegation != NULL)
529                 nfs_do_return_delegation(inode, delegation, 1);
530 }
531 
532 /**
533  * nfs_inode_return_delegation - synchronously return a delegation
534  * @inode: inode to process
535  *
536  * This routine will always flush any dirty data to disk on the
537  * assumption that if we need to return the delegation, then
538  * we should stop caching.
539  *
540  * Returns zero on success, or a negative errno value.
541  */
542 int nfs4_inode_return_delegation(struct inode *inode)
543 {
544         struct nfs_inode *nfsi = NFS_I(inode);
545         struct nfs_delegation *delegation;
546         int err = 0;
547 
548         nfs_wb_all(inode);
549         delegation = nfs_start_delegation_return(nfsi);
550         if (delegation != NULL)
551                 err = nfs_end_delegation_return(inode, delegation, 1);
552         return err;
553 }
554 
555 static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
556                 struct nfs_delegation *delegation)
557 {
558         set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
559         set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
560 }
561 
562 static void nfs_mark_return_delegation(struct nfs_server *server,
563                 struct nfs_delegation *delegation)
564 {
565         set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
566         set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
567 }
568 
569 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
570 {
571         struct nfs_delegation *delegation;
572         bool ret = false;
573 
574         list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
575                 nfs_mark_return_delegation(server, delegation);
576                 ret = true;
577         }
578         return ret;
579 }
580 
581 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
582 {
583         struct nfs_server *server;
584 
585         rcu_read_lock();
586         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
587                 nfs_server_mark_return_all_delegations(server);
588         rcu_read_unlock();
589 }
590 
591 static void nfs_delegation_run_state_manager(struct nfs_client *clp)
592 {
593         if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
594                 nfs4_schedule_state_manager(clp);
595 }
596 
597 /**
598  * nfs_expire_all_delegations
599  * @clp: client to process
600  *
601  */
602 void nfs_expire_all_delegations(struct nfs_client *clp)
603 {
604         nfs_client_mark_return_all_delegations(clp);
605         nfs_delegation_run_state_manager(clp);
606 }
607 
608 /**
609  * nfs_super_return_all_delegations - return delegations for one superblock
610  * @sb: sb to process
611  *
612  */
613 void nfs_server_return_all_delegations(struct nfs_server *server)
614 {
615         struct nfs_client *clp = server->nfs_client;
616         bool need_wait;
617 
618         if (clp == NULL)
619                 return;
620 
621         rcu_read_lock();
622         need_wait = nfs_server_mark_return_all_delegations(server);
623         rcu_read_unlock();
624 
625         if (need_wait) {
626                 nfs4_schedule_state_manager(clp);
627                 nfs4_wait_clnt_recover(clp);
628         }
629 }
630 
631 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server,
632                                                  fmode_t flags)
633 {
634         struct nfs_delegation *delegation;
635 
636         list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
637                 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
638                         continue;
639                 if (delegation->type & flags)
640                         nfs_mark_return_if_closed_delegation(server, delegation);
641         }
642 }
643 
644 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp,
645                                                         fmode_t flags)
646 {
647         struct nfs_server *server;
648 
649         rcu_read_lock();
650         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
651                 nfs_mark_return_unused_delegation_types(server, flags);
652         rcu_read_unlock();
653 }
654 
655 static void nfs_revoke_delegation(struct inode *inode)
656 {
657         struct nfs_delegation *delegation;
658         rcu_read_lock();
659         delegation = rcu_dereference(NFS_I(inode)->delegation);
660         if (delegation != NULL) {
661                 set_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
662                 nfs_mark_return_delegation(NFS_SERVER(inode), delegation);
663         }
664         rcu_read_unlock();
665 }
666 
667 void nfs_remove_bad_delegation(struct inode *inode)
668 {
669         struct nfs_delegation *delegation;
670 
671         nfs_revoke_delegation(inode);
672         delegation = nfs_inode_detach_delegation(inode);
673         if (delegation) {
674                 nfs_inode_find_state_and_recover(inode, &delegation->stateid);
675                 nfs_free_delegation(delegation);
676         }
677 }
678 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);
679 
680 /**
681  * nfs_expire_unused_delegation_types
682  * @clp: client to process
683  * @flags: delegation types to expire
684  *
685  */
686 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags)
687 {
688         nfs_client_mark_return_unused_delegation_types(clp, flags);
689         nfs_delegation_run_state_manager(clp);
690 }
691 
692 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
693 {
694         struct nfs_delegation *delegation;
695 
696         list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
697                 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
698                         continue;
699                 nfs_mark_return_if_closed_delegation(server, delegation);
700         }
701 }
702 
703 /**
704  * nfs_expire_unreferenced_delegations - Eliminate unused delegations
705  * @clp: nfs_client to process
706  *
707  */
708 void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
709 {
710         struct nfs_server *server;
711 
712         rcu_read_lock();
713         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
714                 nfs_mark_return_unreferenced_delegations(server);
715         rcu_read_unlock();
716 
717         nfs_delegation_run_state_manager(clp);
718 }
719 
720 /**
721  * nfs_async_inode_return_delegation - asynchronously return a delegation
722  * @inode: inode to process
723  * @stateid: state ID information
724  *
725  * Returns zero on success, or a negative errno value.
726  */
727 int nfs_async_inode_return_delegation(struct inode *inode,
728                                       const nfs4_stateid *stateid)
729 {
730         struct nfs_server *server = NFS_SERVER(inode);
731         struct nfs_client *clp = server->nfs_client;
732         struct nfs_delegation *delegation;
733 
734         rcu_read_lock();
735         delegation = rcu_dereference(NFS_I(inode)->delegation);
736         if (delegation == NULL)
737                 goto out_enoent;
738         if (stateid != NULL &&
739             !clp->cl_mvops->match_stateid(&delegation->stateid, stateid))
740                 goto out_enoent;
741         nfs_mark_return_delegation(server, delegation);
742         rcu_read_unlock();
743 
744         nfs_delegation_run_state_manager(clp);
745         return 0;
746 out_enoent:
747         rcu_read_unlock();
748         return -ENOENT;
749 }
750 
751 static struct inode *
752 nfs_delegation_find_inode_server(struct nfs_server *server,
753                                  const struct nfs_fh *fhandle)
754 {
755         struct nfs_delegation *delegation;
756         struct inode *res = NULL;
757 
758         list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
759                 spin_lock(&delegation->lock);
760                 if (delegation->inode != NULL &&
761                     nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
762                         res = igrab(delegation->inode);
763                 }
764                 spin_unlock(&delegation->lock);
765                 if (res != NULL)
766                         break;
767         }
768         return res;
769 }
770 
771 /**
772  * nfs_delegation_find_inode - retrieve the inode associated with a delegation
773  * @clp: client state handle
774  * @fhandle: filehandle from a delegation recall
775  *
776  * Returns pointer to inode matching "fhandle," or NULL if a matching inode
777  * cannot be found.
778  */
779 struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
780                                         const struct nfs_fh *fhandle)
781 {
782         struct nfs_server *server;
783         struct inode *res = NULL;
784 
785         rcu_read_lock();
786         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
787                 res = nfs_delegation_find_inode_server(server, fhandle);
788                 if (res != NULL)
789                         break;
790         }
791         rcu_read_unlock();
792         return res;
793 }
794 
795 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
796 {
797         struct nfs_delegation *delegation;
798 
799         list_for_each_entry_rcu(delegation, &server->delegations, super_list)
800                 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
801 }
802 
803 /**
804  * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
805  * @clp: nfs_client to process
806  *
807  */
808 void nfs_delegation_mark_reclaim(struct nfs_client *clp)
809 {
810         struct nfs_server *server;
811 
812         rcu_read_lock();
813         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
814                 nfs_delegation_mark_reclaim_server(server);
815         rcu_read_unlock();
816 }
817 
818 /**
819  * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
820  * @clp: nfs_client to process
821  *
822  */
823 void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
824 {
825         struct nfs_delegation *delegation;
826         struct nfs_server *server;
827         struct inode *inode;
828 
829 restart:
830         rcu_read_lock();
831         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
832                 list_for_each_entry_rcu(delegation, &server->delegations,
833                                                                 super_list) {
834                         if (test_bit(NFS_DELEGATION_RETURNING,
835                                                 &delegation->flags))
836                                 continue;
837                         if (test_bit(NFS_DELEGATION_NEED_RECLAIM,
838                                                 &delegation->flags) == 0)
839                                 continue;
840                         if (!nfs_sb_active(server->super))
841                                 continue;
842                         inode = nfs_delegation_grab_inode(delegation);
843                         if (inode == NULL) {
844                                 rcu_read_unlock();
845                                 nfs_sb_deactive(server->super);
846                                 goto restart;
847                         }
848                         delegation = nfs_start_delegation_return_locked(NFS_I(inode));
849                         rcu_read_unlock();
850                         if (delegation != NULL) {
851                                 delegation = nfs_detach_delegation(NFS_I(inode),
852                                         delegation, server);
853                                 if (delegation != NULL)
854                                         nfs_free_delegation(delegation);
855                         }
856                         iput(inode);
857                         nfs_sb_deactive(server->super);
858                         goto restart;
859                 }
860         }
861         rcu_read_unlock();
862 }
863 
864 /**
865  * nfs_delegations_present - check for existence of delegations
866  * @clp: client state handle
867  *
868  * Returns one if there are any nfs_delegation structures attached
869  * to this nfs_client.
870  */
871 int nfs_delegations_present(struct nfs_client *clp)
872 {
873         struct nfs_server *server;
874         int ret = 0;
875 
876         rcu_read_lock();
877         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
878                 if (!list_empty(&server->delegations)) {
879                         ret = 1;
880                         break;
881                 }
882         rcu_read_unlock();
883         return ret;
884 }
885 
886 /**
887  * nfs4_copy_delegation_stateid - Copy inode's state ID information
888  * @inode: inode to check
889  * @flags: delegation type requirement
890  * @dst: stateid data structure to fill in
891  * @cred: optional argument to retrieve credential
892  *
893  * Returns "true" and fills in "dst->data" * if inode had a delegation,
894  * otherwise "false" is returned.
895  */
896 bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags,
897                 nfs4_stateid *dst, struct rpc_cred **cred)
898 {
899         struct nfs_inode *nfsi = NFS_I(inode);
900         struct nfs_delegation *delegation;
901         bool ret;
902 
903         flags &= FMODE_READ|FMODE_WRITE;
904         rcu_read_lock();
905         delegation = rcu_dereference(nfsi->delegation);
906         ret = nfs4_is_valid_delegation(delegation, flags);
907         if (ret) {
908                 nfs4_stateid_copy(dst, &delegation->stateid);
909                 nfs_mark_delegation_referenced(delegation);
910                 if (cred)
911                         *cred = get_rpccred(delegation->cred);
912         }
913         rcu_read_unlock();
914         return ret;
915 }
916 
917 /**
918  * nfs4_delegation_flush_on_close - Check if we must flush file on close
919  * @inode: inode to check
920  *
921  * This function checks the number of outstanding writes to the file
922  * against the delegation 'space_limit' field to see if
923  * the spec requires us to flush the file on close.
924  */
925 bool nfs4_delegation_flush_on_close(const struct inode *inode)
926 {
927         struct nfs_inode *nfsi = NFS_I(inode);
928         struct nfs_delegation *delegation;
929         bool ret = true;
930 
931         rcu_read_lock();
932         delegation = rcu_dereference(nfsi->delegation);
933         if (delegation == NULL || !(delegation->type & FMODE_WRITE))
934                 goto out;
935         if (nfsi->nrequests < delegation->pagemod_limit)
936                 ret = false;
937 out:
938         rcu_read_unlock();
939         return ret;
940 }
941 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp