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
;
90 if (inode
->i_flock
== NULL
)
93 /* Protect inode->i_flock using the i_lock */
94 spin_lock(&inode
->i_lock
);
95 for (fl
= inode
->i_flock
; fl
!= NULL
; fl
= fl
->fl_next
) {
96 if (!(fl
->fl_flags
& (FL_POSIX
|FL_FLOCK
)))
98 if (nfs_file_open_context(fl
->fl_file
) != ctx
)
100 spin_unlock(&inode
->i_lock
);
101 status
= nfs4_lock_delegation_recall(fl
, state
, stateid
);
104 spin_lock(&inode
->i_lock
);
106 spin_unlock(&inode
->i_lock
);
111 static int nfs_delegation_claim_opens(struct inode
*inode
, const nfs4_stateid
*stateid
)
113 struct nfs_inode
*nfsi
= NFS_I(inode
);
114 struct nfs_open_context
*ctx
;
115 struct nfs4_state_owner
*sp
;
116 struct nfs4_state
*state
;
121 spin_lock(&inode
->i_lock
);
122 list_for_each_entry(ctx
, &nfsi
->open_files
, list
) {
126 if (!test_bit(NFS_DELEGATED_STATE
, &state
->flags
))
128 if (!nfs4_valid_open_stateid(state
))
130 if (!nfs4_stateid_match(&state
->stateid
, stateid
))
132 get_nfs_open_context(ctx
);
133 spin_unlock(&inode
->i_lock
);
135 /* Block nfs4_proc_unlck */
136 mutex_lock(&sp
->so_delegreturn_mutex
);
137 seq
= raw_seqcount_begin(&sp
->so_reclaim_seqcount
);
138 err
= nfs4_open_delegation_recall(ctx
, state
, stateid
);
140 err
= nfs_delegation_claim_locks(ctx
, state
, stateid
);
141 if (!err
&& read_seqcount_retry(&sp
->so_reclaim_seqcount
, seq
))
143 mutex_unlock(&sp
->so_delegreturn_mutex
);
144 put_nfs_open_context(ctx
);
149 spin_unlock(&inode
->i_lock
);
154 * nfs_inode_reclaim_delegation - process a delegation reclaim request
155 * @inode: inode to process
156 * @cred: credential to use for request
157 * @res: new delegation state from server
160 void nfs_inode_reclaim_delegation(struct inode
*inode
, struct rpc_cred
*cred
,
161 struct nfs_openres
*res
)
163 struct nfs_delegation
*delegation
;
164 struct rpc_cred
*oldcred
= NULL
;
167 delegation
= rcu_dereference(NFS_I(inode
)->delegation
);
168 if (delegation
!= NULL
) {
169 spin_lock(&delegation
->lock
);
170 if (delegation
->inode
!= NULL
) {
171 nfs4_stateid_copy(&delegation
->stateid
, &res
->delegation
);
172 delegation
->type
= res
->delegation_type
;
173 delegation
->maxsize
= res
->maxsize
;
174 oldcred
= delegation
->cred
;
175 delegation
->cred
= get_rpccred(cred
);
176 clear_bit(NFS_DELEGATION_NEED_RECLAIM
,
178 NFS_I(inode
)->delegation_state
= delegation
->type
;
179 spin_unlock(&delegation
->lock
);
180 put_rpccred(oldcred
);
182 trace_nfs4_reclaim_delegation(inode
, res
->delegation_type
);
184 /* We appear to have raced with a delegation return. */
185 spin_unlock(&delegation
->lock
);
187 nfs_inode_set_delegation(inode
, cred
, res
);
194 static int nfs_do_return_delegation(struct inode
*inode
, struct nfs_delegation
*delegation
, int issync
)
198 if (!test_bit(NFS_DELEGATION_REVOKED
, &delegation
->flags
))
199 res
= nfs4_proc_delegreturn(inode
,
201 &delegation
->stateid
,
203 nfs_free_delegation(delegation
);
207 static struct inode
*nfs_delegation_grab_inode(struct nfs_delegation
*delegation
)
209 struct inode
*inode
= NULL
;
211 spin_lock(&delegation
->lock
);
212 if (delegation
->inode
!= NULL
)
213 inode
= igrab(delegation
->inode
);
214 spin_unlock(&delegation
->lock
);
218 static struct nfs_delegation
*
219 nfs_start_delegation_return_locked(struct nfs_inode
*nfsi
)
221 struct nfs_delegation
*ret
= NULL
;
222 struct nfs_delegation
*delegation
= rcu_dereference(nfsi
->delegation
);
224 if (delegation
== NULL
)
226 spin_lock(&delegation
->lock
);
227 if (!test_and_set_bit(NFS_DELEGATION_RETURNING
, &delegation
->flags
))
229 spin_unlock(&delegation
->lock
);
234 static struct nfs_delegation
*
235 nfs_start_delegation_return(struct nfs_inode
*nfsi
)
237 struct nfs_delegation
*delegation
;
240 delegation
= nfs_start_delegation_return_locked(nfsi
);
246 nfs_abort_delegation_return(struct nfs_delegation
*delegation
,
247 struct nfs_client
*clp
)
250 spin_lock(&delegation
->lock
);
251 clear_bit(NFS_DELEGATION_RETURNING
, &delegation
->flags
);
252 set_bit(NFS_DELEGATION_RETURN
, &delegation
->flags
);
253 spin_unlock(&delegation
->lock
);
254 set_bit(NFS4CLNT_DELEGRETURN
, &clp
->cl_state
);
257 static struct nfs_delegation
*
258 nfs_detach_delegation_locked(struct nfs_inode
*nfsi
,
259 struct nfs_delegation
*delegation
,
260 struct nfs_client
*clp
)
262 struct nfs_delegation
*deleg_cur
=
263 rcu_dereference_protected(nfsi
->delegation
,
264 lockdep_is_held(&clp
->cl_lock
));
266 if (deleg_cur
== NULL
|| delegation
!= deleg_cur
)
269 spin_lock(&delegation
->lock
);
270 set_bit(NFS_DELEGATION_RETURNING
, &delegation
->flags
);
271 list_del_rcu(&delegation
->super_list
);
272 delegation
->inode
= NULL
;
273 nfsi
->delegation_state
= 0;
274 rcu_assign_pointer(nfsi
->delegation
, NULL
);
275 spin_unlock(&delegation
->lock
);
279 static struct nfs_delegation
*nfs_detach_delegation(struct nfs_inode
*nfsi
,
280 struct nfs_delegation
*delegation
,
281 struct nfs_server
*server
)
283 struct nfs_client
*clp
= server
->nfs_client
;
285 spin_lock(&clp
->cl_lock
);
286 delegation
= nfs_detach_delegation_locked(nfsi
, delegation
, clp
);
287 spin_unlock(&clp
->cl_lock
);
291 static struct nfs_delegation
*
292 nfs_inode_detach_delegation(struct inode
*inode
)
294 struct nfs_inode
*nfsi
= NFS_I(inode
);
295 struct nfs_server
*server
= NFS_SERVER(inode
);
296 struct nfs_delegation
*delegation
;
298 delegation
= nfs_start_delegation_return(nfsi
);
299 if (delegation
== NULL
)
301 return nfs_detach_delegation(nfsi
, delegation
, server
);
305 * nfs_inode_set_delegation - set up a delegation on an inode
306 * @inode: inode to which delegation applies
307 * @cred: cred to use for subsequent delegation processing
308 * @res: new delegation state from server
310 * Returns zero on success, or a negative errno value.
312 int nfs_inode_set_delegation(struct inode
*inode
, struct rpc_cred
*cred
, struct nfs_openres
*res
)
314 struct nfs_server
*server
= NFS_SERVER(inode
);
315 struct nfs_client
*clp
= server
->nfs_client
;
316 struct nfs_inode
*nfsi
= NFS_I(inode
);
317 struct nfs_delegation
*delegation
, *old_delegation
;
318 struct nfs_delegation
*freeme
= NULL
;
321 delegation
= kmalloc(sizeof(*delegation
), GFP_NOFS
);
322 if (delegation
== NULL
)
324 nfs4_stateid_copy(&delegation
->stateid
, &res
->delegation
);
325 delegation
->type
= res
->delegation_type
;
326 delegation
->maxsize
= res
->maxsize
;
327 delegation
->change_attr
= inode
->i_version
;
328 delegation
->cred
= get_rpccred(cred
);
329 delegation
->inode
= inode
;
330 delegation
->flags
= 1<<NFS_DELEGATION_REFERENCED
;
331 spin_lock_init(&delegation
->lock
);
333 spin_lock(&clp
->cl_lock
);
334 old_delegation
= rcu_dereference_protected(nfsi
->delegation
,
335 lockdep_is_held(&clp
->cl_lock
));
336 if (old_delegation
!= NULL
) {
337 if (nfs4_stateid_match(&delegation
->stateid
,
338 &old_delegation
->stateid
) &&
339 delegation
->type
== old_delegation
->type
) {
343 * Deal with broken servers that hand out two
344 * delegations for the same file.
345 * Allow for upgrades to a WRITE delegation, but
348 dfprintk(FILE, "%s: server %s handed out "
349 "a duplicate delegation!\n",
350 __func__
, clp
->cl_hostname
);
351 if (delegation
->type
== old_delegation
->type
||
352 !(delegation
->type
& FMODE_WRITE
)) {
357 freeme
= nfs_detach_delegation_locked(nfsi
,
358 old_delegation
, clp
);
362 list_add_rcu(&delegation
->super_list
, &server
->delegations
);
363 nfsi
->delegation_state
= delegation
->type
;
364 rcu_assign_pointer(nfsi
->delegation
, delegation
);
367 /* Ensure we revalidate the attributes and page cache! */
368 spin_lock(&inode
->i_lock
);
369 nfsi
->cache_validity
|= NFS_INO_REVAL_FORCED
;
370 spin_unlock(&inode
->i_lock
);
371 trace_nfs4_set_delegation(inode
, res
->delegation_type
);
374 spin_unlock(&clp
->cl_lock
);
375 if (delegation
!= NULL
)
376 nfs_free_delegation(delegation
);
378 nfs_do_return_delegation(inode
, freeme
, 0);
383 * Basic procedure for returning a delegation to the server
385 static int nfs_end_delegation_return(struct inode
*inode
, struct nfs_delegation
*delegation
, int issync
)
387 struct nfs_client
*clp
= NFS_SERVER(inode
)->nfs_client
;
388 struct nfs_inode
*nfsi
= NFS_I(inode
);
391 if (delegation
== NULL
)
394 if (test_bit(NFS_DELEGATION_REVOKED
, &delegation
->flags
))
396 err
= nfs_delegation_claim_opens(inode
, &delegation
->stateid
);
397 if (!issync
|| err
!= -EAGAIN
)
400 * Guard against state recovery
402 err
= nfs4_wait_clnt_recover(clp
);
406 nfs_abort_delegation_return(delegation
, clp
);
409 if (!nfs_detach_delegation(nfsi
, delegation
, NFS_SERVER(inode
)))
412 err
= nfs_do_return_delegation(inode
, delegation
, issync
);
417 static bool nfs_delegation_need_return(struct nfs_delegation
*delegation
)
421 if (test_and_clear_bit(NFS_DELEGATION_RETURN
, &delegation
->flags
))
423 if (test_and_clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED
, &delegation
->flags
) && !ret
) {
426 spin_lock(&delegation
->lock
);
427 inode
= delegation
->inode
;
428 if (inode
&& list_empty(&NFS_I(inode
)->open_files
))
430 spin_unlock(&delegation
->lock
);
436 * nfs_client_return_marked_delegations - return previously marked delegations
437 * @clp: nfs_client to process
439 * Note that this function is designed to be called by the state
440 * manager thread. For this reason, it cannot flush the dirty data,
441 * since that could deadlock in case of a state recovery error.
443 * Returns zero on success, or a negative errno value.
445 int nfs_client_return_marked_delegations(struct nfs_client
*clp
)
447 struct nfs_delegation
*delegation
;
448 struct nfs_server
*server
;
454 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
) {
455 list_for_each_entry_rcu(delegation
, &server
->delegations
,
457 if (!nfs_delegation_need_return(delegation
))
459 inode
= nfs_delegation_grab_inode(delegation
);
462 delegation
= nfs_start_delegation_return_locked(NFS_I(inode
));
465 err
= nfs_end_delegation_return(inode
, delegation
, 0);
469 set_bit(NFS4CLNT_DELEGRETURN
, &clp
->cl_state
);
478 * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
479 * @inode: inode to process
481 * Does not protect against delegation reclaims, therefore really only safe
482 * to be called from nfs4_clear_inode().
484 void nfs_inode_return_delegation_noreclaim(struct inode
*inode
)
486 struct nfs_delegation
*delegation
;
488 delegation
= nfs_inode_detach_delegation(inode
);
489 if (delegation
!= NULL
)
490 nfs_do_return_delegation(inode
, delegation
, 0);
494 * nfs_inode_return_delegation - synchronously return a delegation
495 * @inode: inode to process
497 * This routine will always flush any dirty data to disk on the
498 * assumption that if we need to return the delegation, then
499 * we should stop caching.
501 * Returns zero on success, or a negative errno value.
503 int nfs4_inode_return_delegation(struct inode
*inode
)
505 struct nfs_inode
*nfsi
= NFS_I(inode
);
506 struct nfs_delegation
*delegation
;
510 delegation
= nfs_start_delegation_return(nfsi
);
511 if (delegation
!= NULL
)
512 err
= nfs_end_delegation_return(inode
, delegation
, 1);
516 static void nfs_mark_return_if_closed_delegation(struct nfs_server
*server
,
517 struct nfs_delegation
*delegation
)
519 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED
, &delegation
->flags
);
520 set_bit(NFS4CLNT_DELEGRETURN
, &server
->nfs_client
->cl_state
);
523 static void nfs_mark_return_delegation(struct nfs_server
*server
,
524 struct nfs_delegation
*delegation
)
526 set_bit(NFS_DELEGATION_RETURN
, &delegation
->flags
);
527 set_bit(NFS4CLNT_DELEGRETURN
, &server
->nfs_client
->cl_state
);
530 static bool nfs_server_mark_return_all_delegations(struct nfs_server
*server
)
532 struct nfs_delegation
*delegation
;
535 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
) {
536 nfs_mark_return_delegation(server
, delegation
);
542 static void nfs_client_mark_return_all_delegations(struct nfs_client
*clp
)
544 struct nfs_server
*server
;
547 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
548 nfs_server_mark_return_all_delegations(server
);
552 static void nfs_delegation_run_state_manager(struct nfs_client
*clp
)
554 if (test_bit(NFS4CLNT_DELEGRETURN
, &clp
->cl_state
))
555 nfs4_schedule_state_manager(clp
);
559 * nfs_expire_all_delegations
560 * @clp: client to process
563 void nfs_expire_all_delegations(struct nfs_client
*clp
)
565 nfs_client_mark_return_all_delegations(clp
);
566 nfs_delegation_run_state_manager(clp
);
570 * nfs_super_return_all_delegations - return delegations for one superblock
574 void nfs_server_return_all_delegations(struct nfs_server
*server
)
576 struct nfs_client
*clp
= server
->nfs_client
;
583 need_wait
= nfs_server_mark_return_all_delegations(server
);
587 nfs4_schedule_state_manager(clp
);
588 nfs4_wait_clnt_recover(clp
);
592 static void nfs_mark_return_unused_delegation_types(struct nfs_server
*server
,
595 struct nfs_delegation
*delegation
;
597 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
) {
598 if ((delegation
->type
== (FMODE_READ
|FMODE_WRITE
)) && !(flags
& FMODE_WRITE
))
600 if (delegation
->type
& flags
)
601 nfs_mark_return_if_closed_delegation(server
, delegation
);
605 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client
*clp
,
608 struct nfs_server
*server
;
611 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
612 nfs_mark_return_unused_delegation_types(server
, flags
);
616 static void nfs_revoke_delegation(struct inode
*inode
)
618 struct nfs_delegation
*delegation
;
620 delegation
= rcu_dereference(NFS_I(inode
)->delegation
);
621 if (delegation
!= NULL
) {
622 set_bit(NFS_DELEGATION_REVOKED
, &delegation
->flags
);
623 nfs_mark_return_delegation(NFS_SERVER(inode
), delegation
);
628 void nfs_remove_bad_delegation(struct inode
*inode
)
630 struct nfs_delegation
*delegation
;
632 nfs_revoke_delegation(inode
);
633 delegation
= nfs_inode_detach_delegation(inode
);
635 nfs_inode_find_state_and_recover(inode
, &delegation
->stateid
);
636 nfs_free_delegation(delegation
);
639 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation
);
642 * nfs_expire_unused_delegation_types
643 * @clp: client to process
644 * @flags: delegation types to expire
647 void nfs_expire_unused_delegation_types(struct nfs_client
*clp
, fmode_t flags
)
649 nfs_client_mark_return_unused_delegation_types(clp
, flags
);
650 nfs_delegation_run_state_manager(clp
);
653 static void nfs_mark_return_unreferenced_delegations(struct nfs_server
*server
)
655 struct nfs_delegation
*delegation
;
657 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
) {
658 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED
, &delegation
->flags
))
660 nfs_mark_return_if_closed_delegation(server
, delegation
);
665 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
666 * @clp: nfs_client to process
669 void nfs_expire_unreferenced_delegations(struct nfs_client
*clp
)
671 struct nfs_server
*server
;
674 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
675 nfs_mark_return_unreferenced_delegations(server
);
678 nfs_delegation_run_state_manager(clp
);
682 * nfs_async_inode_return_delegation - asynchronously return a delegation
683 * @inode: inode to process
684 * @stateid: state ID information
686 * Returns zero on success, or a negative errno value.
688 int nfs_async_inode_return_delegation(struct inode
*inode
,
689 const nfs4_stateid
*stateid
)
691 struct nfs_server
*server
= NFS_SERVER(inode
);
692 struct nfs_client
*clp
= server
->nfs_client
;
693 struct nfs_delegation
*delegation
;
695 filemap_flush(inode
->i_mapping
);
698 delegation
= rcu_dereference(NFS_I(inode
)->delegation
);
699 if (delegation
== NULL
)
702 if (!clp
->cl_mvops
->match_stateid(&delegation
->stateid
, stateid
))
704 nfs_mark_return_delegation(server
, delegation
);
707 nfs_delegation_run_state_manager(clp
);
714 static struct inode
*
715 nfs_delegation_find_inode_server(struct nfs_server
*server
,
716 const struct nfs_fh
*fhandle
)
718 struct nfs_delegation
*delegation
;
719 struct inode
*res
= NULL
;
721 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
) {
722 spin_lock(&delegation
->lock
);
723 if (delegation
->inode
!= NULL
&&
724 nfs_compare_fh(fhandle
, &NFS_I(delegation
->inode
)->fh
) == 0) {
725 res
= igrab(delegation
->inode
);
727 spin_unlock(&delegation
->lock
);
735 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
736 * @clp: client state handle
737 * @fhandle: filehandle from a delegation recall
739 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
742 struct inode
*nfs_delegation_find_inode(struct nfs_client
*clp
,
743 const struct nfs_fh
*fhandle
)
745 struct nfs_server
*server
;
746 struct inode
*res
= NULL
;
749 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
) {
750 res
= nfs_delegation_find_inode_server(server
, fhandle
);
758 static void nfs_delegation_mark_reclaim_server(struct nfs_server
*server
)
760 struct nfs_delegation
*delegation
;
762 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
)
763 set_bit(NFS_DELEGATION_NEED_RECLAIM
, &delegation
->flags
);
767 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
768 * @clp: nfs_client to process
771 void nfs_delegation_mark_reclaim(struct nfs_client
*clp
)
773 struct nfs_server
*server
;
776 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
777 nfs_delegation_mark_reclaim_server(server
);
782 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
783 * @clp: nfs_client to process
786 void nfs_delegation_reap_unclaimed(struct nfs_client
*clp
)
788 struct nfs_delegation
*delegation
;
789 struct nfs_server
*server
;
794 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
) {
795 list_for_each_entry_rcu(delegation
, &server
->delegations
,
797 if (test_bit(NFS_DELEGATION_NEED_RECLAIM
,
798 &delegation
->flags
) == 0)
800 inode
= nfs_delegation_grab_inode(delegation
);
803 delegation
= nfs_detach_delegation(NFS_I(inode
),
807 if (delegation
!= NULL
)
808 nfs_free_delegation(delegation
);
817 * nfs_delegations_present - check for existence of delegations
818 * @clp: client state handle
820 * Returns one if there are any nfs_delegation structures attached
821 * to this nfs_client.
823 int nfs_delegations_present(struct nfs_client
*clp
)
825 struct nfs_server
*server
;
829 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
830 if (!list_empty(&server
->delegations
)) {
839 * nfs4_copy_delegation_stateid - Copy inode's state ID information
840 * @dst: stateid data structure to fill in
841 * @inode: inode to check
842 * @flags: delegation type requirement
844 * Returns "true" and fills in "dst->data" * if inode had a delegation,
845 * otherwise "false" is returned.
847 bool nfs4_copy_delegation_stateid(nfs4_stateid
*dst
, struct inode
*inode
,
850 struct nfs_inode
*nfsi
= NFS_I(inode
);
851 struct nfs_delegation
*delegation
;
854 flags
&= FMODE_READ
|FMODE_WRITE
;
856 delegation
= rcu_dereference(nfsi
->delegation
);
857 ret
= (delegation
!= NULL
&& (delegation
->type
& flags
) == flags
);
859 nfs4_stateid_copy(dst
, &delegation
->stateid
);
860 nfs_mark_delegation_referenced(delegation
);