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_update_inplace_delegation(struct nfs_delegation *delegation,
311 const struct nfs_delegation *update)
313 if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) {
314 delegation->stateid.seqid = update->stateid.seqid;
316 delegation->type = update->type;
321 * nfs_inode_set_delegation - set up a delegation on an inode
322 * @inode: inode to which delegation applies
323 * @cred: cred to use for subsequent delegation processing
324 * @res: new delegation state from server
326 * Returns zero on success, or a negative errno value.
328 int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
330 struct nfs_server *server = NFS_SERVER(inode);
331 struct nfs_client *clp = server->nfs_client;
332 struct nfs_inode *nfsi = NFS_I(inode);
333 struct nfs_delegation *delegation, *old_delegation;
334 struct nfs_delegation *freeme = NULL;
337 delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
338 if (delegation == NULL)
340 nfs4_stateid_copy(&delegation->stateid, &res->delegation);
341 delegation->type = res->delegation_type;
342 delegation->maxsize = res->maxsize;
343 delegation->change_attr = inode->i_version;
344 delegation->cred = get_rpccred(cred);
345 delegation->inode = inode;
346 delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
347 spin_lock_init(&delegation->lock);
349 spin_lock(&clp->cl_lock);
350 old_delegation = rcu_dereference_protected(nfsi->delegation,
351 lockdep_is_held(&clp->cl_lock));
352 if (old_delegation != NULL) {
353 /* Is this an update of the existing delegation? */
354 if (nfs4_stateid_match_other(&old_delegation->stateid,
355 &delegation->stateid)) {
356 nfs_update_inplace_delegation(old_delegation,
358 nfsi->delegation_state = old_delegation->type;
362 * Deal with broken servers that hand out two
363 * delegations for the same file.
364 * Allow for upgrades to a WRITE delegation, but
367 dfprintk(FILE, "%s: server %s handed out "
368 "a duplicate delegation!\n",
369 __func__, clp->cl_hostname);
370 if (delegation->type == old_delegation->type ||
371 !(delegation->type & FMODE_WRITE)) {
376 freeme = nfs_detach_delegation_locked(nfsi,
377 old_delegation, clp);
381 list_add_rcu(&delegation->super_list, &server->delegations);
382 nfsi->delegation_state = delegation->type;
383 rcu_assign_pointer(nfsi->delegation, delegation);
386 /* Ensure we revalidate the attributes and page cache! */
387 spin_lock(&inode->i_lock);
388 nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
389 spin_unlock(&inode->i_lock);
390 trace_nfs4_set_delegation(inode, res->delegation_type);
393 spin_unlock(&clp->cl_lock);
394 if (delegation != NULL)
395 nfs_free_delegation(delegation);
397 nfs_do_return_delegation(inode, freeme, 0);
402 * Basic procedure for returning a delegation to the server
404 static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
406 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
407 struct nfs_inode *nfsi = NFS_I(inode);
410 if (delegation == NULL)
413 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
415 err = nfs_delegation_claim_opens(inode, &delegation->stateid);
416 if (!issync || err != -EAGAIN)
419 * Guard against state recovery
421 err = nfs4_wait_clnt_recover(clp);
425 nfs_abort_delegation_return(delegation, clp);
428 if (!nfs_detach_delegation(nfsi, delegation, NFS_SERVER(inode)))
431 err = nfs_do_return_delegation(inode, delegation, issync);
436 static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
440 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
442 if (test_and_clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) && !ret) {
445 spin_lock(&delegation->lock);
446 inode = delegation->inode;
447 if (inode && list_empty(&NFS_I(inode)->open_files))
449 spin_unlock(&delegation->lock);
455 * nfs_client_return_marked_delegations - return previously marked delegations
456 * @clp: nfs_client to process
458 * Note that this function is designed to be called by the state
459 * manager thread. For this reason, it cannot flush the dirty data,
460 * since that could deadlock in case of a state recovery error.
462 * Returns zero on success, or a negative errno value.
464 int nfs_client_return_marked_delegations(struct nfs_client *clp)
466 struct nfs_delegation *delegation;
467 struct nfs_server *server;
473 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
474 list_for_each_entry_rcu(delegation, &server->delegations,
476 if (!nfs_delegation_need_return(delegation))
478 inode = nfs_delegation_grab_inode(delegation);
481 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
484 err = nfs_end_delegation_return(inode, delegation, 0);
488 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
497 * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
498 * @inode: inode to process
500 * Does not protect against delegation reclaims, therefore really only safe
501 * to be called from nfs4_clear_inode().
503 void nfs_inode_return_delegation_noreclaim(struct inode *inode)
505 struct nfs_delegation *delegation;
507 delegation = nfs_inode_detach_delegation(inode);
508 if (delegation != NULL)
509 nfs_do_return_delegation(inode, delegation, 0);
513 * nfs_inode_return_delegation - synchronously return a delegation
514 * @inode: inode to process
516 * This routine will always flush any dirty data to disk on the
517 * assumption that if we need to return the delegation, then
518 * we should stop caching.
520 * Returns zero on success, or a negative errno value.
522 int nfs4_inode_return_delegation(struct inode *inode)
524 struct nfs_inode *nfsi = NFS_I(inode);
525 struct nfs_delegation *delegation;
529 delegation = nfs_start_delegation_return(nfsi);
530 if (delegation != NULL)
531 err = nfs_end_delegation_return(inode, delegation, 1);
535 static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
536 struct nfs_delegation *delegation)
538 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
539 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
542 static void nfs_mark_return_delegation(struct nfs_server *server,
543 struct nfs_delegation *delegation)
545 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
546 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
549 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
551 struct nfs_delegation *delegation;
554 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
555 nfs_mark_return_delegation(server, delegation);
561 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
563 struct nfs_server *server;
566 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
567 nfs_server_mark_return_all_delegations(server);
571 static void nfs_delegation_run_state_manager(struct nfs_client *clp)
573 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
574 nfs4_schedule_state_manager(clp);
578 * nfs_expire_all_delegations
579 * @clp: client to process
582 void nfs_expire_all_delegations(struct nfs_client *clp)
584 nfs_client_mark_return_all_delegations(clp);
585 nfs_delegation_run_state_manager(clp);
589 * nfs_super_return_all_delegations - return delegations for one superblock
593 void nfs_server_return_all_delegations(struct nfs_server *server)
595 struct nfs_client *clp = server->nfs_client;
602 need_wait = nfs_server_mark_return_all_delegations(server);
606 nfs4_schedule_state_manager(clp);
607 nfs4_wait_clnt_recover(clp);
611 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server,
614 struct nfs_delegation *delegation;
616 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
617 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
619 if (delegation->type & flags)
620 nfs_mark_return_if_closed_delegation(server, delegation);
624 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp,
627 struct nfs_server *server;
630 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
631 nfs_mark_return_unused_delegation_types(server, flags);
635 static void nfs_revoke_delegation(struct inode *inode)
637 struct nfs_delegation *delegation;
639 delegation = rcu_dereference(NFS_I(inode)->delegation);
640 if (delegation != NULL) {
641 set_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
642 nfs_mark_return_delegation(NFS_SERVER(inode), delegation);
647 void nfs_remove_bad_delegation(struct inode *inode)
649 struct nfs_delegation *delegation;
651 nfs_revoke_delegation(inode);
652 delegation = nfs_inode_detach_delegation(inode);
654 nfs_inode_find_state_and_recover(inode, &delegation->stateid);
655 nfs_free_delegation(delegation);
658 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);
661 * nfs_expire_unused_delegation_types
662 * @clp: client to process
663 * @flags: delegation types to expire
666 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags)
668 nfs_client_mark_return_unused_delegation_types(clp, flags);
669 nfs_delegation_run_state_manager(clp);
672 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
674 struct nfs_delegation *delegation;
676 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
677 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
679 nfs_mark_return_if_closed_delegation(server, delegation);
684 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
685 * @clp: nfs_client to process
688 void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
690 struct nfs_server *server;
693 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
694 nfs_mark_return_unreferenced_delegations(server);
697 nfs_delegation_run_state_manager(clp);
701 * nfs_async_inode_return_delegation - asynchronously return a delegation
702 * @inode: inode to process
703 * @stateid: state ID information
705 * Returns zero on success, or a negative errno value.
707 int nfs_async_inode_return_delegation(struct inode *inode,
708 const nfs4_stateid *stateid)
710 struct nfs_server *server = NFS_SERVER(inode);
711 struct nfs_client *clp = server->nfs_client;
712 struct nfs_delegation *delegation;
714 filemap_flush(inode->i_mapping);
717 delegation = rcu_dereference(NFS_I(inode)->delegation);
718 if (delegation == NULL)
721 if (!clp->cl_mvops->match_stateid(&delegation->stateid, stateid))
723 nfs_mark_return_delegation(server, delegation);
726 nfs_delegation_run_state_manager(clp);
733 static struct inode *
734 nfs_delegation_find_inode_server(struct nfs_server *server,
735 const struct nfs_fh *fhandle)
737 struct nfs_delegation *delegation;
738 struct inode *res = NULL;
740 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
741 spin_lock(&delegation->lock);
742 if (delegation->inode != NULL &&
743 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
744 res = igrab(delegation->inode);
746 spin_unlock(&delegation->lock);
754 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
755 * @clp: client state handle
756 * @fhandle: filehandle from a delegation recall
758 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
761 struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
762 const struct nfs_fh *fhandle)
764 struct nfs_server *server;
765 struct inode *res = NULL;
768 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
769 res = nfs_delegation_find_inode_server(server, fhandle);
777 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
779 struct nfs_delegation *delegation;
781 list_for_each_entry_rcu(delegation, &server->delegations, super_list)
782 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
786 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
787 * @clp: nfs_client to process
790 void nfs_delegation_mark_reclaim(struct nfs_client *clp)
792 struct nfs_server *server;
795 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
796 nfs_delegation_mark_reclaim_server(server);
801 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
802 * @clp: nfs_client to process
805 void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
807 struct nfs_delegation *delegation;
808 struct nfs_server *server;
813 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
814 list_for_each_entry_rcu(delegation, &server->delegations,
816 if (test_bit(NFS_DELEGATION_NEED_RECLAIM,
817 &delegation->flags) == 0)
819 inode = nfs_delegation_grab_inode(delegation);
822 delegation = nfs_detach_delegation(NFS_I(inode),
826 if (delegation != NULL)
827 nfs_free_delegation(delegation);
836 * nfs_delegations_present - check for existence of delegations
837 * @clp: client state handle
839 * Returns one if there are any nfs_delegation structures attached
840 * to this nfs_client.
842 int nfs_delegations_present(struct nfs_client *clp)
844 struct nfs_server *server;
848 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
849 if (!list_empty(&server->delegations)) {
858 * nfs4_copy_delegation_stateid - Copy inode's state ID information
859 * @dst: stateid data structure to fill in
860 * @inode: inode to check
861 * @flags: delegation type requirement
863 * Returns "true" and fills in "dst->data" * if inode had a delegation,
864 * otherwise "false" is returned.
866 bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode,
869 struct nfs_inode *nfsi = NFS_I(inode);
870 struct nfs_delegation *delegation;
873 flags &= FMODE_READ|FMODE_WRITE;
875 delegation = rcu_dereference(nfsi->delegation);
876 ret = (delegation != NULL && (delegation->type & flags) == flags);
878 nfs4_stateid_copy(dst, &delegation->stateid);
879 nfs_mark_delegation_referenced(delegation);