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 spin_unlock(&delegation->lock);
185 put_rpccred(oldcred);
186 trace_nfs4_reclaim_delegation(inode, res->delegation_type);
188 /* We appear to have raced with a delegation return. */
189 spin_unlock(&delegation->lock);
191 nfs_inode_set_delegation(inode, cred, res);
198 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
202 if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
203 res = nfs4_proc_delegreturn(inode,
205 &delegation->stateid,
207 nfs_free_delegation(delegation);
211 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
213 struct inode *inode = NULL;
215 spin_lock(&delegation->lock);
216 if (delegation->inode != NULL)
217 inode = igrab(delegation->inode);
218 spin_unlock(&delegation->lock);
222 static struct nfs_delegation *
223 nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
225 struct nfs_delegation *ret = NULL;
226 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
228 if (delegation == NULL)
230 spin_lock(&delegation->lock);
231 if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
233 spin_unlock(&delegation->lock);
238 static struct nfs_delegation *
239 nfs_start_delegation_return(struct nfs_inode *nfsi)
241 struct nfs_delegation *delegation;
244 delegation = nfs_start_delegation_return_locked(nfsi);
250 nfs_abort_delegation_return(struct nfs_delegation *delegation,
251 struct nfs_client *clp)
254 spin_lock(&delegation->lock);
255 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
256 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
257 spin_unlock(&delegation->lock);
258 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
261 static struct nfs_delegation *
262 nfs_detach_delegation_locked(struct nfs_inode *nfsi,
263 struct nfs_delegation *delegation,
264 struct nfs_client *clp)
266 struct nfs_delegation *deleg_cur =
267 rcu_dereference_protected(nfsi->delegation,
268 lockdep_is_held(&clp->cl_lock));
270 if (deleg_cur == NULL || delegation != deleg_cur)
273 spin_lock(&delegation->lock);
274 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
275 list_del_rcu(&delegation->super_list);
276 delegation->inode = NULL;
277 rcu_assign_pointer(nfsi->delegation, NULL);
278 spin_unlock(&delegation->lock);
282 static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
283 struct nfs_delegation *delegation,
284 struct nfs_server *server)
286 struct nfs_client *clp = server->nfs_client;
288 spin_lock(&clp->cl_lock);
289 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp);
290 spin_unlock(&clp->cl_lock);
294 static struct nfs_delegation *
295 nfs_inode_detach_delegation(struct inode *inode)
297 struct nfs_inode *nfsi = NFS_I(inode);
298 struct nfs_server *server = NFS_SERVER(inode);
299 struct nfs_delegation *delegation;
301 delegation = nfs_start_delegation_return(nfsi);
302 if (delegation == NULL)
304 return nfs_detach_delegation(nfsi, delegation, server);
308 nfs_update_inplace_delegation(struct nfs_delegation *delegation,
309 const struct nfs_delegation *update)
311 if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) {
312 delegation->stateid.seqid = update->stateid.seqid;
314 delegation->type = update->type;
319 * nfs_inode_set_delegation - set up a delegation on an inode
320 * @inode: inode to which delegation applies
321 * @cred: cred to use for subsequent delegation processing
322 * @res: new delegation state from server
324 * Returns zero on success, or a negative errno value.
326 int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
328 struct nfs_server *server = NFS_SERVER(inode);
329 struct nfs_client *clp = server->nfs_client;
330 struct nfs_inode *nfsi = NFS_I(inode);
331 struct nfs_delegation *delegation, *old_delegation;
332 struct nfs_delegation *freeme = NULL;
335 delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
336 if (delegation == NULL)
338 nfs4_stateid_copy(&delegation->stateid, &res->delegation);
339 delegation->type = res->delegation_type;
340 delegation->maxsize = res->maxsize;
341 delegation->change_attr = inode->i_version;
342 delegation->cred = get_rpccred(cred);
343 delegation->inode = inode;
344 delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
345 spin_lock_init(&delegation->lock);
347 spin_lock(&clp->cl_lock);
348 old_delegation = rcu_dereference_protected(nfsi->delegation,
349 lockdep_is_held(&clp->cl_lock));
350 if (old_delegation != NULL) {
351 /* Is this an update of the existing delegation? */
352 if (nfs4_stateid_match_other(&old_delegation->stateid,
353 &delegation->stateid)) {
354 nfs_update_inplace_delegation(old_delegation,
359 * Deal with broken servers that hand out two
360 * delegations for the same file.
361 * Allow for upgrades to a WRITE delegation, but
364 dfprintk(FILE, "%s: server %s handed out "
365 "a duplicate delegation!\n",
366 __func__, clp->cl_hostname);
367 if (delegation->type == old_delegation->type ||
368 !(delegation->type & FMODE_WRITE)) {
373 if (test_and_set_bit(NFS_DELEGATION_RETURNING,
374 &old_delegation->flags))
376 freeme = nfs_detach_delegation_locked(nfsi,
377 old_delegation, clp);
381 list_add_rcu(&delegation->super_list, &server->delegations);
382 rcu_assign_pointer(nfsi->delegation, delegation);
385 /* Ensure we revalidate the attributes and page cache! */
386 spin_lock(&inode->i_lock);
387 nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
388 spin_unlock(&inode->i_lock);
389 trace_nfs4_set_delegation(inode, res->delegation_type);
392 spin_unlock(&clp->cl_lock);
393 if (delegation != NULL)
394 nfs_free_delegation(delegation);
396 nfs_do_return_delegation(inode, freeme, 0);
401 * Basic procedure for returning a delegation to the server
403 static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
405 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
406 struct nfs_inode *nfsi = NFS_I(inode);
409 if (delegation == NULL)
412 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
414 err = nfs_delegation_claim_opens(inode, &delegation->stateid);
415 if (!issync || err != -EAGAIN)
418 * Guard against state recovery
420 err = nfs4_wait_clnt_recover(clp);
424 nfs_abort_delegation_return(delegation, clp);
427 if (!nfs_detach_delegation(nfsi, delegation, NFS_SERVER(inode)))
430 err = nfs_do_return_delegation(inode, delegation, issync);
435 static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
439 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
441 if (test_and_clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) && !ret) {
444 spin_lock(&delegation->lock);
445 inode = delegation->inode;
446 if (inode && list_empty(&NFS_I(inode)->open_files))
448 spin_unlock(&delegation->lock);
454 * nfs_client_return_marked_delegations - return previously marked delegations
455 * @clp: nfs_client to process
457 * Note that this function is designed to be called by the state
458 * manager thread. For this reason, it cannot flush the dirty data,
459 * since that could deadlock in case of a state recovery error.
461 * Returns zero on success, or a negative errno value.
463 int nfs_client_return_marked_delegations(struct nfs_client *clp)
465 struct nfs_delegation *delegation;
466 struct nfs_server *server;
472 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
473 list_for_each_entry_rcu(delegation, &server->delegations,
475 if (!nfs_delegation_need_return(delegation))
477 if (!nfs_sb_active(server->super))
479 inode = nfs_delegation_grab_inode(delegation);
482 nfs_sb_deactive(server->super);
485 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
488 err = nfs_end_delegation_return(inode, delegation, 0);
490 nfs_sb_deactive(server->super);
493 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
502 * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
503 * @inode: inode to process
505 * Does not protect against delegation reclaims, therefore really only safe
506 * to be called from nfs4_clear_inode().
508 void nfs_inode_return_delegation_noreclaim(struct inode *inode)
510 struct nfs_delegation *delegation;
512 delegation = nfs_inode_detach_delegation(inode);
513 if (delegation != NULL)
514 nfs_do_return_delegation(inode, delegation, 0);
518 * nfs_inode_return_delegation - synchronously return a delegation
519 * @inode: inode to process
521 * This routine will always flush any dirty data to disk on the
522 * assumption that if we need to return the delegation, then
523 * we should stop caching.
525 * Returns zero on success, or a negative errno value.
527 int nfs4_inode_return_delegation(struct inode *inode)
529 struct nfs_inode *nfsi = NFS_I(inode);
530 struct nfs_delegation *delegation;
534 delegation = nfs_start_delegation_return(nfsi);
535 if (delegation != NULL)
536 err = nfs_end_delegation_return(inode, delegation, 1);
540 static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
541 struct nfs_delegation *delegation)
543 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
544 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
547 static void nfs_mark_return_delegation(struct nfs_server *server,
548 struct nfs_delegation *delegation)
550 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
551 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
554 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
556 struct nfs_delegation *delegation;
559 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
560 nfs_mark_return_delegation(server, delegation);
566 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
568 struct nfs_server *server;
571 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
572 nfs_server_mark_return_all_delegations(server);
576 static void nfs_delegation_run_state_manager(struct nfs_client *clp)
578 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
579 nfs4_schedule_state_manager(clp);
583 * nfs_expire_all_delegations
584 * @clp: client to process
587 void nfs_expire_all_delegations(struct nfs_client *clp)
589 nfs_client_mark_return_all_delegations(clp);
590 nfs_delegation_run_state_manager(clp);
594 * nfs_super_return_all_delegations - return delegations for one superblock
598 void nfs_server_return_all_delegations(struct nfs_server *server)
600 struct nfs_client *clp = server->nfs_client;
607 need_wait = nfs_server_mark_return_all_delegations(server);
611 nfs4_schedule_state_manager(clp);
612 nfs4_wait_clnt_recover(clp);
616 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server,
619 struct nfs_delegation *delegation;
621 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
622 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
624 if (delegation->type & flags)
625 nfs_mark_return_if_closed_delegation(server, delegation);
629 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp,
632 struct nfs_server *server;
635 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
636 nfs_mark_return_unused_delegation_types(server, flags);
640 static void nfs_revoke_delegation(struct inode *inode)
642 struct nfs_delegation *delegation;
644 delegation = rcu_dereference(NFS_I(inode)->delegation);
645 if (delegation != NULL) {
646 set_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
647 nfs_mark_return_delegation(NFS_SERVER(inode), delegation);
652 void nfs_remove_bad_delegation(struct inode *inode)
654 struct nfs_delegation *delegation;
656 nfs_revoke_delegation(inode);
657 delegation = nfs_inode_detach_delegation(inode);
659 nfs_inode_find_state_and_recover(inode, &delegation->stateid);
660 nfs_free_delegation(delegation);
663 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);
666 * nfs_expire_unused_delegation_types
667 * @clp: client to process
668 * @flags: delegation types to expire
671 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags)
673 nfs_client_mark_return_unused_delegation_types(clp, flags);
674 nfs_delegation_run_state_manager(clp);
677 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
679 struct nfs_delegation *delegation;
681 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
682 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
684 nfs_mark_return_if_closed_delegation(server, delegation);
689 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
690 * @clp: nfs_client to process
693 void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
695 struct nfs_server *server;
698 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
699 nfs_mark_return_unreferenced_delegations(server);
702 nfs_delegation_run_state_manager(clp);
706 * nfs_async_inode_return_delegation - asynchronously return a delegation
707 * @inode: inode to process
708 * @stateid: state ID information
710 * Returns zero on success, or a negative errno value.
712 int nfs_async_inode_return_delegation(struct inode *inode,
713 const nfs4_stateid *stateid)
715 struct nfs_server *server = NFS_SERVER(inode);
716 struct nfs_client *clp = server->nfs_client;
717 struct nfs_delegation *delegation;
719 filemap_flush(inode->i_mapping);
722 delegation = rcu_dereference(NFS_I(inode)->delegation);
723 if (delegation == NULL)
726 if (!clp->cl_mvops->match_stateid(&delegation->stateid, stateid))
728 nfs_mark_return_delegation(server, delegation);
731 nfs_delegation_run_state_manager(clp);
738 static struct inode *
739 nfs_delegation_find_inode_server(struct nfs_server *server,
740 const struct nfs_fh *fhandle)
742 struct nfs_delegation *delegation;
743 struct inode *res = NULL;
745 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
746 spin_lock(&delegation->lock);
747 if (delegation->inode != NULL &&
748 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
749 res = igrab(delegation->inode);
751 spin_unlock(&delegation->lock);
759 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
760 * @clp: client state handle
761 * @fhandle: filehandle from a delegation recall
763 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
766 struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
767 const struct nfs_fh *fhandle)
769 struct nfs_server *server;
770 struct inode *res = NULL;
773 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
774 res = nfs_delegation_find_inode_server(server, fhandle);
782 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
784 struct nfs_delegation *delegation;
786 list_for_each_entry_rcu(delegation, &server->delegations, super_list)
787 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
791 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
792 * @clp: nfs_client to process
795 void nfs_delegation_mark_reclaim(struct nfs_client *clp)
797 struct nfs_server *server;
800 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
801 nfs_delegation_mark_reclaim_server(server);
806 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
807 * @clp: nfs_client to process
810 void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
812 struct nfs_delegation *delegation;
813 struct nfs_server *server;
818 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
819 list_for_each_entry_rcu(delegation, &server->delegations,
821 if (test_bit(NFS_DELEGATION_NEED_RECLAIM,
822 &delegation->flags) == 0)
824 if (!nfs_sb_active(server->super))
826 inode = nfs_delegation_grab_inode(delegation);
829 nfs_sb_deactive(server->super);
832 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
834 if (delegation != NULL) {
835 delegation = nfs_detach_delegation(NFS_I(inode),
837 if (delegation != NULL)
838 nfs_free_delegation(delegation);
841 nfs_sb_deactive(server->super);
849 * nfs_delegations_present - check for existence of delegations
850 * @clp: client state handle
852 * Returns one if there are any nfs_delegation structures attached
853 * to this nfs_client.
855 int nfs_delegations_present(struct nfs_client *clp)
857 struct nfs_server *server;
861 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
862 if (!list_empty(&server->delegations)) {
871 * nfs4_copy_delegation_stateid - Copy inode's state ID information
872 * @dst: stateid data structure to fill in
873 * @inode: inode to check
874 * @flags: delegation type requirement
876 * Returns "true" and fills in "dst->data" * if inode had a delegation,
877 * otherwise "false" is returned.
879 bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode,
882 struct nfs_inode *nfsi = NFS_I(inode);
883 struct nfs_delegation *delegation;
886 flags &= FMODE_READ|FMODE_WRITE;
888 delegation = rcu_dereference(nfsi->delegation);
889 ret = (delegation != NULL && (delegation->type & flags) == flags);
891 nfs4_stateid_copy(dst, &delegation->stateid);
892 nfs_mark_delegation_referenced(delegation);