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
);