2 * linux/fs/nfs/delegation.c
4 * Copyright (C) 2004 Trond Myklebust
6 * NFS file delegation management
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>
16 #include <linux/nfs4.h>
17 #include <linux/nfs_fs.h>
18 #include <linux/nfs_xdr.h>
21 #include "delegation.h"
23 #include "nfs4trace.h"
25 static void nfs_free_delegation(struct nfs_delegation *delegation)
27 if (delegation->cred) {
28 put_rpccred(delegation->cred);
29 delegation->cred = NULL;
31 kfree_rcu(delegation, rcu);
35 * nfs_mark_delegation_referenced - set delegation's REFERENCED flag
36 * @delegation: delegation to process
39 void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
41 set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
45 nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark)
47 struct nfs_delegation *delegation;
50 flags &= FMODE_READ|FMODE_WRITE;
52 delegation = rcu_dereference(NFS_I(inode)->delegation);
53 if (delegation != NULL && (delegation->type & flags) == flags &&
54 !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
56 nfs_mark_delegation_referenced(delegation);
63 * nfs_have_delegation - check if inode has a delegation, mark it
64 * NFS_DELEGATION_REFERENCED if there is one.
65 * @inode: inode to check
66 * @flags: delegation types to check for
68 * Returns one if inode has the indicated delegation, otherwise zero.
70 int nfs4_have_delegation(struct inode *inode, fmode_t flags)
72 return nfs4_do_check_delegation(inode, flags, true);
76 * nfs4_check_delegation - check if inode has a delegation, do not mark
77 * NFS_DELEGATION_REFERENCED if it has one.
79 int nfs4_check_delegation(struct inode *inode, fmode_t flags)
81 return nfs4_do_check_delegation(inode, flags, false);
84 static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state, const nfs4_stateid *stateid)
86 struct inode *inode = state->inode;
88 struct file_lock_context *flctx = inode->i_flctx;
89 struct list_head *list;
95 list = &flctx->flc_posix;
96 spin_lock(&flctx->flc_lock);
98 list_for_each_entry(fl, list, fl_list) {
99 if (nfs_file_open_context(fl->fl_file) != ctx)
101 spin_unlock(&flctx->flc_lock);
102 status = nfs4_lock_delegation_recall(fl, state, stateid);
105 spin_lock(&flctx->flc_lock);
107 if (list == &flctx->flc_posix) {
108 list = &flctx->flc_flock;
111 spin_unlock(&flctx->flc_lock);
116 static int nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *stateid)
118 struct nfs_inode *nfsi = NFS_I(inode);
119 struct nfs_open_context *ctx;
120 struct nfs4_state_owner *sp;
121 struct nfs4_state *state;
126 spin_lock(&inode->i_lock);
127 list_for_each_entry(ctx, &nfsi->open_files, list) {
131 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
133 if (!nfs4_valid_open_stateid(state))
135 if (!nfs4_stateid_match(&state->stateid, stateid))
137 get_nfs_open_context(ctx);
138 spin_unlock(&inode->i_lock);
140 /* Block nfs4_proc_unlck */
141 mutex_lock(&sp->so_delegreturn_mutex);
142 seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
143 err = nfs4_open_delegation_recall(ctx, state, stateid);
145 err = nfs_delegation_claim_locks(ctx, state, stateid);
146 if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
148 mutex_unlock(&sp->so_delegreturn_mutex);
149 put_nfs_open_context(ctx);
154 spin_unlock(&inode->i_lock);
159 * nfs_inode_reclaim_delegation - process a delegation reclaim request
160 * @inode: inode to process
161 * @cred: credential to use for request
162 * @res: new delegation state from server
165 void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred,
166 struct nfs_openres *res)
168 struct nfs_delegation *delegation;
169 struct rpc_cred *oldcred = NULL;
172 delegation = rcu_dereference(NFS_I(inode)->delegation);
173 if (delegation != NULL) {
174 spin_lock(&delegation->lock);
175 if (delegation->inode != NULL) {
176 nfs4_stateid_copy(&delegation->stateid, &res->delegation);
177 delegation->type = res->delegation_type;
178 delegation->maxsize = res->maxsize;
179 oldcred = delegation->cred;
180 delegation->cred = get_rpccred(cred);
181 clear_bit(NFS_DELEGATION_NEED_RECLAIM,
183 NFS_I(inode)->delegation_state = delegation->type;
184 spin_unlock(&delegation->lock);
185 put_rpccred(oldcred);
187 trace_nfs4_reclaim_delegation(inode, res->delegation_type);
189 /* We appear to have raced with a delegation return. */
190 spin_unlock(&delegation->lock);
192 nfs_inode_set_delegation(inode, cred, res);
199 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
203 if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
204 res = nfs4_proc_delegreturn(inode,
206 &delegation->stateid,
208 nfs_free_delegation(delegation);
212 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
214 struct inode *inode = NULL;
216 spin_lock(&delegation->lock);
217 if (delegation->inode != NULL)
218 inode = igrab(delegation->inode);
219 spin_unlock(&delegation->lock);
223 static struct nfs_delegation *
224 nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
226 struct nfs_delegation *ret = NULL;
227 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
229 if (delegation == NULL)
231 spin_lock(&delegation->lock);
232 if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
234 spin_unlock(&delegation->lock);
239 static struct nfs_delegation *
240 nfs_start_delegation_return(struct nfs_inode *nfsi)
242 struct nfs_delegation *delegation;
245 delegation = nfs_start_delegation_return_locked(nfsi);
251 nfs_abort_delegation_return(struct nfs_delegation *delegation,
252 struct nfs_client *clp)
255 spin_lock(&delegation->lock);
256 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
257 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
258 spin_unlock(&delegation->lock);
259 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
262 static struct nfs_delegation *
263 nfs_detach_delegation_locked(struct nfs_inode *nfsi,
264 struct nfs_delegation *delegation,
265 struct nfs_client *clp)
267 struct nfs_delegation *deleg_cur =
268 rcu_dereference_protected(nfsi->delegation,
269 lockdep_is_held(&clp->cl_lock));
271 if (deleg_cur == NULL || delegation != deleg_cur)
274 spin_lock(&delegation->lock);
275 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
276 list_del_rcu(&delegation->super_list);
277 delegation->inode = NULL;
278 nfsi->delegation_state = 0;
279 rcu_assign_pointer(nfsi->delegation, NULL);
280 spin_unlock(&delegation->lock);
284 static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
285 struct nfs_delegation *delegation,
286 struct nfs_server *server)
288 struct nfs_client *clp = server->nfs_client;
290 spin_lock(&clp->cl_lock);
291 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp);
292 spin_unlock(&clp->cl_lock);
296 static struct nfs_delegation *
297 nfs_inode_detach_delegation(struct inode *inode)
299 struct nfs_inode *nfsi = NFS_I(inode);
300 struct nfs_server *server = NFS_SERVER(inode);
301 struct nfs_delegation *delegation;
303 delegation = nfs_start_delegation_return(nfsi);
304 if (delegation == NULL)
306 return nfs_detach_delegation(nfsi, delegation, server);
310 * nfs_inode_set_delegation - set up a delegation on an inode
311 * @inode: inode to which delegation applies
312 * @cred: cred to use for subsequent delegation processing
313 * @res: new delegation state from server
315 * Returns zero on success, or a negative errno value.
317 int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
319 struct nfs_server *server = NFS_SERVER(inode);
320 struct nfs_client *clp = server->nfs_client;
321 struct nfs_inode *nfsi = NFS_I(inode);
322 struct nfs_delegation *delegation, *old_delegation;
323 struct nfs_delegation *freeme = NULL;
326 delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
327 if (delegation == NULL)
329 nfs4_stateid_copy(&delegation->stateid, &res->delegation);
330 delegation->type = res->delegation_type;
331 delegation->maxsize = res->maxsize;
332 delegation->change_attr = inode->i_version;
333 delegation->cred = get_rpccred(cred);
334 delegation->inode = inode;
335 delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
336 spin_lock_init(&delegation->lock);
338 spin_lock(&clp->cl_lock);
339 old_delegation = rcu_dereference_protected(nfsi->delegation,
340 lockdep_is_held(&clp->cl_lock));
341 if (old_delegation != NULL) {
342 if (nfs4_stateid_match(&delegation->stateid,
343 &old_delegation->stateid) &&
344 delegation->type == old_delegation->type) {
348 * Deal with broken servers that hand out two
349 * delegations for the same file.
350 * Allow for upgrades to a WRITE delegation, but
353 dfprintk(FILE, "%s: server %s handed out "
354 "a duplicate delegation!\n",
355 __func__, clp->cl_hostname);
356 if (delegation->type == old_delegation->type ||
357 !(delegation->type & FMODE_WRITE)) {
362 freeme = nfs_detach_delegation_locked(nfsi,
363 old_delegation, clp);
367 list_add_rcu(&delegation->super_list, &server->delegations);
368 nfsi->delegation_state = delegation->type;
369 rcu_assign_pointer(nfsi->delegation, delegation);
372 /* Ensure we revalidate the attributes and page cache! */
373 spin_lock(&inode->i_lock);
374 nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
375 spin_unlock(&inode->i_lock);
376 trace_nfs4_set_delegation(inode, res->delegation_type);
379 spin_unlock(&clp->cl_lock);
380 if (delegation != NULL)
381 nfs_free_delegation(delegation);
383 nfs_do_return_delegation(inode, freeme, 0);
388 * Basic procedure for returning a delegation to the server
390 static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
392 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
393 struct nfs_inode *nfsi = NFS_I(inode);
396 if (delegation == NULL)
399 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
401 err = nfs_delegation_claim_opens(inode, &delegation->stateid);
402 if (!issync || err != -EAGAIN)
405 * Guard against state recovery
407 err = nfs4_wait_clnt_recover(clp);
411 nfs_abort_delegation_return(delegation, clp);
414 if (!nfs_detach_delegation(nfsi, delegation, NFS_SERVER(inode)))
417 err = nfs_do_return_delegation(inode, delegation, issync);
422 static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
426 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
428 if (test_and_clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) && !ret) {
431 spin_lock(&delegation->lock);
432 inode = delegation->inode;
433 if (inode && list_empty(&NFS_I(inode)->open_files))
435 spin_unlock(&delegation->lock);
441 * nfs_client_return_marked_delegations - return previously marked delegations
442 * @clp: nfs_client to process
444 * Note that this function is designed to be called by the state
445 * manager thread. For this reason, it cannot flush the dirty data,
446 * since that could deadlock in case of a state recovery error.
448 * Returns zero on success, or a negative errno value.
450 int nfs_client_return_marked_delegations(struct nfs_client *clp)
452 struct nfs_delegation *delegation;
453 struct nfs_server *server;
459 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
460 list_for_each_entry_rcu(delegation, &server->delegations,
462 if (!nfs_delegation_need_return(delegation))
464 inode = nfs_delegation_grab_inode(delegation);
467 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
470 err = nfs_end_delegation_return(inode, delegation, 0);
474 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
483 * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
484 * @inode: inode to process
486 * Does not protect against delegation reclaims, therefore really only safe
487 * to be called from nfs4_clear_inode().
489 void nfs_inode_return_delegation_noreclaim(struct inode *inode)
491 struct nfs_delegation *delegation;
493 delegation = nfs_inode_detach_delegation(inode);
494 if (delegation != NULL)
495 nfs_do_return_delegation(inode, delegation, 0);
499 * nfs_inode_return_delegation - synchronously return a delegation
500 * @inode: inode to process
502 * This routine will always flush any dirty data to disk on the
503 * assumption that if we need to return the delegation, then
504 * we should stop caching.
506 * Returns zero on success, or a negative errno value.
508 int nfs4_inode_return_delegation(struct inode *inode)
510 struct nfs_inode *nfsi = NFS_I(inode);
511 struct nfs_delegation *delegation;
515 delegation = nfs_start_delegation_return(nfsi);
516 if (delegation != NULL)
517 err = nfs_end_delegation_return(inode, delegation, 1);
521 static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
522 struct nfs_delegation *delegation)
524 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
525 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
528 static void nfs_mark_return_delegation(struct nfs_server *server,
529 struct nfs_delegation *delegation)
531 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
532 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
535 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
537 struct nfs_delegation *delegation;
540 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
541 nfs_mark_return_delegation(server, delegation);
547 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
549 struct nfs_server *server;
552 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
553 nfs_server_mark_return_all_delegations(server);
557 static void nfs_delegation_run_state_manager(struct nfs_client *clp)
559 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
560 nfs4_schedule_state_manager(clp);
564 * nfs_expire_all_delegations
565 * @clp: client to process
568 void nfs_expire_all_delegations(struct nfs_client *clp)
570 nfs_client_mark_return_all_delegations(clp);
571 nfs_delegation_run_state_manager(clp);
575 * nfs_super_return_all_delegations - return delegations for one superblock
579 void nfs_server_return_all_delegations(struct nfs_server *server)
581 struct nfs_client *clp = server->nfs_client;
588 need_wait = nfs_server_mark_return_all_delegations(server);
592 nfs4_schedule_state_manager(clp);
593 nfs4_wait_clnt_recover(clp);
597 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server,
600 struct nfs_delegation *delegation;
602 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
603 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
605 if (delegation->type & flags)
606 nfs_mark_return_if_closed_delegation(server, delegation);
610 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp,
613 struct nfs_server *server;
616 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
617 nfs_mark_return_unused_delegation_types(server, flags);
621 static void nfs_revoke_delegation(struct inode *inode)
623 struct nfs_delegation *delegation;
625 delegation = rcu_dereference(NFS_I(inode)->delegation);
626 if (delegation != NULL) {
627 set_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
628 nfs_mark_return_delegation(NFS_SERVER(inode), delegation);
633 void nfs_remove_bad_delegation(struct inode *inode)
635 struct nfs_delegation *delegation;
637 nfs_revoke_delegation(inode);
638 delegation = nfs_inode_detach_delegation(inode);
640 nfs_inode_find_state_and_recover(inode, &delegation->stateid);
641 nfs_free_delegation(delegation);
644 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);
647 * nfs_expire_unused_delegation_types
648 * @clp: client to process
649 * @flags: delegation types to expire
652 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags)
654 nfs_client_mark_return_unused_delegation_types(clp, flags);
655 nfs_delegation_run_state_manager(clp);
658 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
660 struct nfs_delegation *delegation;
662 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
663 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
665 nfs_mark_return_if_closed_delegation(server, delegation);
670 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
671 * @clp: nfs_client to process
674 void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
676 struct nfs_server *server;
679 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
680 nfs_mark_return_unreferenced_delegations(server);
683 nfs_delegation_run_state_manager(clp);
687 * nfs_async_inode_return_delegation - asynchronously return a delegation
688 * @inode: inode to process
689 * @stateid: state ID information
691 * Returns zero on success, or a negative errno value.
693 int nfs_async_inode_return_delegation(struct inode *inode,
694 const nfs4_stateid *stateid)
696 struct nfs_server *server = NFS_SERVER(inode);
697 struct nfs_client *clp = server->nfs_client;
698 struct nfs_delegation *delegation;
700 filemap_flush(inode->i_mapping);
703 delegation = rcu_dereference(NFS_I(inode)->delegation);
704 if (delegation == NULL)
707 if (!clp->cl_mvops->match_stateid(&delegation->stateid, stateid))
709 nfs_mark_return_delegation(server, delegation);
712 nfs_delegation_run_state_manager(clp);
719 static struct inode *
720 nfs_delegation_find_inode_server(struct nfs_server *server,
721 const struct nfs_fh *fhandle)
723 struct nfs_delegation *delegation;
724 struct inode *res = NULL;
726 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
727 spin_lock(&delegation->lock);
728 if (delegation->inode != NULL &&
729 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
730 res = igrab(delegation->inode);
732 spin_unlock(&delegation->lock);
740 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
741 * @clp: client state handle
742 * @fhandle: filehandle from a delegation recall
744 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
747 struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
748 const struct nfs_fh *fhandle)
750 struct nfs_server *server;
751 struct inode *res = NULL;
754 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
755 res = nfs_delegation_find_inode_server(server, fhandle);
763 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
765 struct nfs_delegation *delegation;
767 list_for_each_entry_rcu(delegation, &server->delegations, super_list)
768 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
772 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
773 * @clp: nfs_client to process
776 void nfs_delegation_mark_reclaim(struct nfs_client *clp)
778 struct nfs_server *server;
781 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
782 nfs_delegation_mark_reclaim_server(server);
787 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
788 * @clp: nfs_client to process
791 void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
793 struct nfs_delegation *delegation;
794 struct nfs_server *server;
799 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
800 list_for_each_entry_rcu(delegation, &server->delegations,
802 if (test_bit(NFS_DELEGATION_NEED_RECLAIM,
803 &delegation->flags) == 0)
805 inode = nfs_delegation_grab_inode(delegation);
808 delegation = nfs_detach_delegation(NFS_I(inode),
812 if (delegation != NULL)
813 nfs_free_delegation(delegation);
822 * nfs_delegations_present - check for existence of delegations
823 * @clp: client state handle
825 * Returns one if there are any nfs_delegation structures attached
826 * to this nfs_client.
828 int nfs_delegations_present(struct nfs_client *clp)
830 struct nfs_server *server;
834 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
835 if (!list_empty(&server->delegations)) {
844 * nfs4_copy_delegation_stateid - Copy inode's state ID information
845 * @dst: stateid data structure to fill in
846 * @inode: inode to check
847 * @flags: delegation type requirement
849 * Returns "true" and fills in "dst->data" * if inode had a delegation,
850 * otherwise "false" is returned.
852 bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode,
855 struct nfs_inode *nfsi = NFS_I(inode);
856 struct nfs_delegation *delegation;
859 flags &= FMODE_READ|FMODE_WRITE;
861 delegation = rcu_dereference(nfsi->delegation);
862 ret = (delegation != NULL && (delegation->type & flags) == flags);
864 nfs4_stateid_copy(dst, &delegation->stateid);
865 nfs_mark_delegation_referenced(delegation);