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"
24 static void nfs_free_delegation(struct nfs_delegation *delegation)
26 if (delegation->cred) {
27 put_rpccred(delegation->cred);
28 delegation->cred = NULL;
30 kfree_rcu(delegation, rcu);
34 * nfs_mark_delegation_referenced - set delegation's REFERENCED flag
35 * @delegation: delegation to process
38 void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
40 set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
44 * nfs_have_delegation - check if inode has a delegation
45 * @inode: inode to check
46 * @flags: delegation types to check for
48 * Returns one if inode has the indicated delegation, otherwise zero.
50 int nfs4_have_delegation(struct inode *inode, fmode_t flags)
52 struct nfs_delegation *delegation;
55 flags &= FMODE_READ|FMODE_WRITE;
57 delegation = rcu_dereference(NFS_I(inode)->delegation);
58 if (delegation != NULL && (delegation->type & flags) == flags &&
59 !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
60 nfs_mark_delegation_referenced(delegation);
67 static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state, const nfs4_stateid *stateid)
69 struct inode *inode = state->inode;
73 if (inode->i_flock == NULL)
76 /* Protect inode->i_flock using the file locks lock */
78 for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
79 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
81 if (nfs_file_open_context(fl->fl_file) != ctx)
84 status = nfs4_lock_delegation_recall(fl, state, stateid);
94 static int nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *stateid)
96 struct nfs_inode *nfsi = NFS_I(inode);
97 struct nfs_open_context *ctx;
98 struct nfs4_state_owner *sp;
99 struct nfs4_state *state;
104 spin_lock(&inode->i_lock);
105 list_for_each_entry(ctx, &nfsi->open_files, list) {
109 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
111 if (!nfs4_valid_open_stateid(state))
113 if (!nfs4_stateid_match(&state->stateid, stateid))
115 get_nfs_open_context(ctx);
116 spin_unlock(&inode->i_lock);
118 /* Block nfs4_proc_unlck */
119 mutex_lock(&sp->so_delegreturn_mutex);
120 seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
121 err = nfs4_open_delegation_recall(ctx, state, stateid);
123 err = nfs_delegation_claim_locks(ctx, state, stateid);
124 if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
126 mutex_unlock(&sp->so_delegreturn_mutex);
127 put_nfs_open_context(ctx);
132 spin_unlock(&inode->i_lock);
137 * nfs_inode_reclaim_delegation - process a delegation reclaim request
138 * @inode: inode to process
139 * @cred: credential to use for request
140 * @res: new delegation state from server
143 void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred,
144 struct nfs_openres *res)
146 struct nfs_delegation *delegation;
147 struct rpc_cred *oldcred = NULL;
150 delegation = rcu_dereference(NFS_I(inode)->delegation);
151 if (delegation != NULL) {
152 spin_lock(&delegation->lock);
153 if (delegation->inode != NULL) {
154 nfs4_stateid_copy(&delegation->stateid, &res->delegation);
155 delegation->type = res->delegation_type;
156 delegation->maxsize = res->maxsize;
157 oldcred = delegation->cred;
158 delegation->cred = get_rpccred(cred);
159 clear_bit(NFS_DELEGATION_NEED_RECLAIM,
161 NFS_I(inode)->delegation_state = delegation->type;
162 spin_unlock(&delegation->lock);
163 put_rpccred(oldcred);
166 /* We appear to have raced with a delegation return. */
167 spin_unlock(&delegation->lock);
169 nfs_inode_set_delegation(inode, cred, res);
176 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
180 if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
181 res = nfs4_proc_delegreturn(inode,
183 &delegation->stateid,
185 nfs_free_delegation(delegation);
189 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
191 struct inode *inode = NULL;
193 spin_lock(&delegation->lock);
194 if (delegation->inode != NULL)
195 inode = igrab(delegation->inode);
196 spin_unlock(&delegation->lock);
200 static struct nfs_delegation *
201 nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
203 struct nfs_delegation *ret = NULL;
204 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
206 if (delegation == NULL)
208 spin_lock(&delegation->lock);
209 if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
211 spin_unlock(&delegation->lock);
216 static struct nfs_delegation *
217 nfs_start_delegation_return(struct nfs_inode *nfsi)
219 struct nfs_delegation *delegation;
222 delegation = nfs_start_delegation_return_locked(nfsi);
228 nfs_abort_delegation_return(struct nfs_delegation *delegation,
229 struct nfs_client *clp)
232 spin_lock(&delegation->lock);
233 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
234 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
235 spin_unlock(&delegation->lock);
236 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
239 static struct nfs_delegation *
240 nfs_detach_delegation_locked(struct nfs_inode *nfsi,
241 struct nfs_delegation *delegation,
242 struct nfs_client *clp)
244 struct nfs_delegation *deleg_cur =
245 rcu_dereference_protected(nfsi->delegation,
246 lockdep_is_held(&clp->cl_lock));
248 if (deleg_cur == NULL || delegation != deleg_cur)
251 spin_lock(&delegation->lock);
252 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
253 list_del_rcu(&delegation->super_list);
254 delegation->inode = NULL;
255 nfsi->delegation_state = 0;
256 rcu_assign_pointer(nfsi->delegation, NULL);
257 spin_unlock(&delegation->lock);
261 static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
262 struct nfs_delegation *delegation,
263 struct nfs_server *server)
265 struct nfs_client *clp = server->nfs_client;
267 spin_lock(&clp->cl_lock);
268 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp);
269 spin_unlock(&clp->cl_lock);
273 static struct nfs_delegation *
274 nfs_inode_detach_delegation(struct inode *inode)
276 struct nfs_inode *nfsi = NFS_I(inode);
277 struct nfs_server *server = NFS_SERVER(inode);
278 struct nfs_delegation *delegation;
280 delegation = nfs_start_delegation_return(nfsi);
281 if (delegation == NULL)
283 return nfs_detach_delegation(nfsi, delegation, server);
287 * nfs_inode_set_delegation - set up a delegation on an inode
288 * @inode: inode to which delegation applies
289 * @cred: cred to use for subsequent delegation processing
290 * @res: new delegation state from server
292 * Returns zero on success, or a negative errno value.
294 int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
296 struct nfs_server *server = NFS_SERVER(inode);
297 struct nfs_client *clp = server->nfs_client;
298 struct nfs_inode *nfsi = NFS_I(inode);
299 struct nfs_delegation *delegation, *old_delegation;
300 struct nfs_delegation *freeme = NULL;
303 delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
304 if (delegation == NULL)
306 nfs4_stateid_copy(&delegation->stateid, &res->delegation);
307 delegation->type = res->delegation_type;
308 delegation->maxsize = res->maxsize;
309 delegation->change_attr = inode->i_version;
310 delegation->cred = get_rpccred(cred);
311 delegation->inode = inode;
312 delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
313 spin_lock_init(&delegation->lock);
315 spin_lock(&clp->cl_lock);
316 old_delegation = rcu_dereference_protected(nfsi->delegation,
317 lockdep_is_held(&clp->cl_lock));
318 if (old_delegation != NULL) {
319 if (nfs4_stateid_match(&delegation->stateid,
320 &old_delegation->stateid) &&
321 delegation->type == old_delegation->type) {
325 * Deal with broken servers that hand out two
326 * delegations for the same file.
327 * Allow for upgrades to a WRITE delegation, but
330 dfprintk(FILE, "%s: server %s handed out "
331 "a duplicate delegation!\n",
332 __func__, clp->cl_hostname);
333 if (delegation->type == old_delegation->type ||
334 !(delegation->type & FMODE_WRITE)) {
339 freeme = nfs_detach_delegation_locked(nfsi,
340 old_delegation, clp);
344 list_add_rcu(&delegation->super_list, &server->delegations);
345 nfsi->delegation_state = delegation->type;
346 rcu_assign_pointer(nfsi->delegation, delegation);
349 /* Ensure we revalidate the attributes and page cache! */
350 spin_lock(&inode->i_lock);
351 nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
352 spin_unlock(&inode->i_lock);
355 spin_unlock(&clp->cl_lock);
356 if (delegation != NULL)
357 nfs_free_delegation(delegation);
359 nfs_do_return_delegation(inode, freeme, 0);
364 * Basic procedure for returning a delegation to the server
366 static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
368 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
369 struct nfs_inode *nfsi = NFS_I(inode);
372 if (delegation == NULL)
375 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
377 err = nfs_delegation_claim_opens(inode, &delegation->stateid);
378 if (!issync || err != -EAGAIN)
381 * Guard against state recovery
383 err = nfs4_wait_clnt_recover(clp);
387 nfs_abort_delegation_return(delegation, clp);
390 if (!nfs_detach_delegation(nfsi, delegation, NFS_SERVER(inode)))
393 err = nfs_do_return_delegation(inode, delegation, issync);
398 static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
402 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
404 if (test_and_clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) && !ret) {
407 spin_lock(&delegation->lock);
408 inode = delegation->inode;
409 if (inode && list_empty(&NFS_I(inode)->open_files))
411 spin_unlock(&delegation->lock);
417 * nfs_client_return_marked_delegations - return previously marked delegations
418 * @clp: nfs_client to process
420 * Note that this function is designed to be called by the state
421 * manager thread. For this reason, it cannot flush the dirty data,
422 * since that could deadlock in case of a state recovery error.
424 * Returns zero on success, or a negative errno value.
426 int nfs_client_return_marked_delegations(struct nfs_client *clp)
428 struct nfs_delegation *delegation;
429 struct nfs_server *server;
435 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
436 list_for_each_entry_rcu(delegation, &server->delegations,
438 if (!nfs_delegation_need_return(delegation))
440 inode = nfs_delegation_grab_inode(delegation);
443 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
446 err = nfs_end_delegation_return(inode, delegation, 0);
450 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
459 * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
460 * @inode: inode to process
462 * Does not protect against delegation reclaims, therefore really only safe
463 * to be called from nfs4_clear_inode().
465 void nfs_inode_return_delegation_noreclaim(struct inode *inode)
467 struct nfs_delegation *delegation;
469 delegation = nfs_inode_detach_delegation(inode);
470 if (delegation != NULL)
471 nfs_do_return_delegation(inode, delegation, 0);
475 * nfs_inode_return_delegation - synchronously return a delegation
476 * @inode: inode to process
478 * This routine will always flush any dirty data to disk on the
479 * assumption that if we need to return the delegation, then
480 * we should stop caching.
482 * Returns zero on success, or a negative errno value.
484 int nfs4_inode_return_delegation(struct inode *inode)
486 struct nfs_inode *nfsi = NFS_I(inode);
487 struct nfs_delegation *delegation;
491 delegation = nfs_start_delegation_return(nfsi);
492 if (delegation != NULL)
493 err = nfs_end_delegation_return(inode, delegation, 1);
497 static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
498 struct nfs_delegation *delegation)
500 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
501 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
504 static void nfs_mark_return_delegation(struct nfs_server *server,
505 struct nfs_delegation *delegation)
507 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
508 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
511 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
513 struct nfs_delegation *delegation;
516 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
517 nfs_mark_return_delegation(server, delegation);
523 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
525 struct nfs_server *server;
528 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
529 nfs_server_mark_return_all_delegations(server);
533 static void nfs_delegation_run_state_manager(struct nfs_client *clp)
535 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
536 nfs4_schedule_state_manager(clp);
540 * nfs_expire_all_delegations
541 * @clp: client to process
544 void nfs_expire_all_delegations(struct nfs_client *clp)
546 nfs_client_mark_return_all_delegations(clp);
547 nfs_delegation_run_state_manager(clp);
551 * nfs_super_return_all_delegations - return delegations for one superblock
555 void nfs_server_return_all_delegations(struct nfs_server *server)
557 struct nfs_client *clp = server->nfs_client;
564 need_wait = nfs_server_mark_return_all_delegations(server);
568 nfs4_schedule_state_manager(clp);
569 nfs4_wait_clnt_recover(clp);
573 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server,
576 struct nfs_delegation *delegation;
578 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
579 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
581 if (delegation->type & flags)
582 nfs_mark_return_if_closed_delegation(server, delegation);
586 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp,
589 struct nfs_server *server;
592 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
593 nfs_mark_return_unused_delegation_types(server, flags);
597 static void nfs_revoke_delegation(struct inode *inode)
599 struct nfs_delegation *delegation;
601 delegation = rcu_dereference(NFS_I(inode)->delegation);
602 if (delegation != NULL) {
603 set_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
604 nfs_mark_return_delegation(NFS_SERVER(inode), delegation);
609 void nfs_remove_bad_delegation(struct inode *inode)
611 struct nfs_delegation *delegation;
613 nfs_revoke_delegation(inode);
614 delegation = nfs_inode_detach_delegation(inode);
616 nfs_inode_find_state_and_recover(inode, &delegation->stateid);
617 nfs_free_delegation(delegation);
620 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);
623 * nfs_expire_unused_delegation_types
624 * @clp: client to process
625 * @flags: delegation types to expire
628 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags)
630 nfs_client_mark_return_unused_delegation_types(clp, flags);
631 nfs_delegation_run_state_manager(clp);
634 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
636 struct nfs_delegation *delegation;
638 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
639 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
641 nfs_mark_return_if_closed_delegation(server, delegation);
646 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
647 * @clp: nfs_client to process
650 void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
652 struct nfs_server *server;
655 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
656 nfs_mark_return_unreferenced_delegations(server);
659 nfs_delegation_run_state_manager(clp);
663 * nfs_async_inode_return_delegation - asynchronously return a delegation
664 * @inode: inode to process
665 * @stateid: state ID information
667 * Returns zero on success, or a negative errno value.
669 int nfs_async_inode_return_delegation(struct inode *inode,
670 const nfs4_stateid *stateid)
672 struct nfs_server *server = NFS_SERVER(inode);
673 struct nfs_client *clp = server->nfs_client;
674 struct nfs_delegation *delegation;
676 filemap_flush(inode->i_mapping);
679 delegation = rcu_dereference(NFS_I(inode)->delegation);
680 if (delegation == NULL)
683 if (!clp->cl_mvops->match_stateid(&delegation->stateid, stateid))
685 nfs_mark_return_delegation(server, delegation);
688 nfs_delegation_run_state_manager(clp);
695 static struct inode *
696 nfs_delegation_find_inode_server(struct nfs_server *server,
697 const struct nfs_fh *fhandle)
699 struct nfs_delegation *delegation;
700 struct inode *res = NULL;
702 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
703 spin_lock(&delegation->lock);
704 if (delegation->inode != NULL &&
705 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
706 res = igrab(delegation->inode);
708 spin_unlock(&delegation->lock);
716 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
717 * @clp: client state handle
718 * @fhandle: filehandle from a delegation recall
720 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
723 struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
724 const struct nfs_fh *fhandle)
726 struct nfs_server *server;
727 struct inode *res = NULL;
730 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
731 res = nfs_delegation_find_inode_server(server, fhandle);
739 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
741 struct nfs_delegation *delegation;
743 list_for_each_entry_rcu(delegation, &server->delegations, super_list)
744 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
748 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
749 * @clp: nfs_client to process
752 void nfs_delegation_mark_reclaim(struct nfs_client *clp)
754 struct nfs_server *server;
757 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
758 nfs_delegation_mark_reclaim_server(server);
763 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
764 * @clp: nfs_client to process
767 void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
769 struct nfs_delegation *delegation;
770 struct nfs_server *server;
775 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
776 list_for_each_entry_rcu(delegation, &server->delegations,
778 if (test_bit(NFS_DELEGATION_NEED_RECLAIM,
779 &delegation->flags) == 0)
781 inode = nfs_delegation_grab_inode(delegation);
784 delegation = nfs_detach_delegation(NFS_I(inode),
788 if (delegation != NULL)
789 nfs_free_delegation(delegation);
798 * nfs_delegations_present - check for existence of delegations
799 * @clp: client state handle
801 * Returns one if there are any nfs_delegation structures attached
802 * to this nfs_client.
804 int nfs_delegations_present(struct nfs_client *clp)
806 struct nfs_server *server;
810 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
811 if (!list_empty(&server->delegations)) {
820 * nfs4_copy_delegation_stateid - Copy inode's state ID information
821 * @dst: stateid data structure to fill in
822 * @inode: inode to check
823 * @flags: delegation type requirement
825 * Returns "true" and fills in "dst->data" * if inode had a delegation,
826 * otherwise "false" is returned.
828 bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode,
831 struct nfs_inode *nfsi = NFS_I(inode);
832 struct nfs_delegation *delegation;
835 flags &= FMODE_READ|FMODE_WRITE;
837 delegation = rcu_dereference(nfsi->delegation);
838 ret = (delegation != NULL && (delegation->type & flags) == flags);
840 nfs4_stateid_copy(dst, &delegation->stateid);
841 nfs_mark_delegation_referenced(delegation);