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_stateid_match(&state
->stateid
, stateid
))
130 get_nfs_open_context(ctx
);
131 spin_unlock(&inode
->i_lock
);
133 /* Block nfs4_proc_unlck */
134 mutex_lock(&sp
->so_delegreturn_mutex
);
135 seq
= raw_seqcount_begin(&sp
->so_reclaim_seqcount
);
136 err
= nfs4_open_delegation_recall(ctx
, state
, stateid
);
138 err
= nfs_delegation_claim_locks(ctx
, state
, stateid
);
139 if (!err
&& read_seqcount_retry(&sp
->so_reclaim_seqcount
, seq
))
141 mutex_unlock(&sp
->so_delegreturn_mutex
);
142 put_nfs_open_context(ctx
);
147 spin_unlock(&inode
->i_lock
);
152 * nfs_inode_reclaim_delegation - process a delegation reclaim request
153 * @inode: inode to process
154 * @cred: credential to use for request
155 * @res: new delegation state from server
158 void nfs_inode_reclaim_delegation(struct inode
*inode
, struct rpc_cred
*cred
,
159 struct nfs_openres
*res
)
161 struct nfs_delegation
*delegation
;
162 struct rpc_cred
*oldcred
= NULL
;
165 delegation
= rcu_dereference(NFS_I(inode
)->delegation
);
166 if (delegation
!= NULL
) {
167 spin_lock(&delegation
->lock
);
168 if (delegation
->inode
!= NULL
) {
169 nfs4_stateid_copy(&delegation
->stateid
, &res
->delegation
);
170 delegation
->type
= res
->delegation_type
;
171 delegation
->maxsize
= res
->maxsize
;
172 oldcred
= delegation
->cred
;
173 delegation
->cred
= get_rpccred(cred
);
174 clear_bit(NFS_DELEGATION_NEED_RECLAIM
,
176 NFS_I(inode
)->delegation_state
= delegation
->type
;
177 spin_unlock(&delegation
->lock
);
178 put_rpccred(oldcred
);
180 trace_nfs4_reclaim_delegation(inode
, res
->delegation_type
);
182 /* We appear to have raced with a delegation return. */
183 spin_unlock(&delegation
->lock
);
185 nfs_inode_set_delegation(inode
, cred
, res
);
192 static int nfs_do_return_delegation(struct inode
*inode
, struct nfs_delegation
*delegation
, int issync
)
196 if (!test_bit(NFS_DELEGATION_REVOKED
, &delegation
->flags
))
197 res
= nfs4_proc_delegreturn(inode
,
199 &delegation
->stateid
,
201 nfs_free_delegation(delegation
);
205 static struct inode
*nfs_delegation_grab_inode(struct nfs_delegation
*delegation
)
207 struct inode
*inode
= NULL
;
209 spin_lock(&delegation
->lock
);
210 if (delegation
->inode
!= NULL
)
211 inode
= igrab(delegation
->inode
);
212 spin_unlock(&delegation
->lock
);
216 static struct nfs_delegation
*
217 nfs_start_delegation_return_locked(struct nfs_inode
*nfsi
)
219 struct nfs_delegation
*ret
= NULL
;
220 struct nfs_delegation
*delegation
= rcu_dereference(nfsi
->delegation
);
222 if (delegation
== NULL
)
224 spin_lock(&delegation
->lock
);
225 if (!test_and_set_bit(NFS_DELEGATION_RETURNING
, &delegation
->flags
))
227 spin_unlock(&delegation
->lock
);
232 static struct nfs_delegation
*
233 nfs_start_delegation_return(struct nfs_inode
*nfsi
)
235 struct nfs_delegation
*delegation
;
238 delegation
= nfs_start_delegation_return_locked(nfsi
);
244 nfs_abort_delegation_return(struct nfs_delegation
*delegation
,
245 struct nfs_client
*clp
)
248 spin_lock(&delegation
->lock
);
249 clear_bit(NFS_DELEGATION_RETURNING
, &delegation
->flags
);
250 set_bit(NFS_DELEGATION_RETURN
, &delegation
->flags
);
251 spin_unlock(&delegation
->lock
);
252 set_bit(NFS4CLNT_DELEGRETURN
, &clp
->cl_state
);
255 static struct nfs_delegation
*
256 nfs_detach_delegation_locked(struct nfs_inode
*nfsi
,
257 struct nfs_delegation
*delegation
,
258 struct nfs_client
*clp
)
260 struct nfs_delegation
*deleg_cur
=
261 rcu_dereference_protected(nfsi
->delegation
,
262 lockdep_is_held(&clp
->cl_lock
));
264 if (deleg_cur
== NULL
|| delegation
!= deleg_cur
)
267 spin_lock(&delegation
->lock
);
268 set_bit(NFS_DELEGATION_RETURNING
, &delegation
->flags
);
269 list_del_rcu(&delegation
->super_list
);
270 delegation
->inode
= NULL
;
271 nfsi
->delegation_state
= 0;
272 rcu_assign_pointer(nfsi
->delegation
, NULL
);
273 spin_unlock(&delegation
->lock
);
277 static struct nfs_delegation
*nfs_detach_delegation(struct nfs_inode
*nfsi
,
278 struct nfs_delegation
*delegation
,
279 struct nfs_server
*server
)
281 struct nfs_client
*clp
= server
->nfs_client
;
283 spin_lock(&clp
->cl_lock
);
284 delegation
= nfs_detach_delegation_locked(nfsi
, delegation
, clp
);
285 spin_unlock(&clp
->cl_lock
);
289 static struct nfs_delegation
*
290 nfs_inode_detach_delegation(struct inode
*inode
)
292 struct nfs_inode
*nfsi
= NFS_I(inode
);
293 struct nfs_server
*server
= NFS_SERVER(inode
);
294 struct nfs_delegation
*delegation
;
296 delegation
= nfs_start_delegation_return(nfsi
);
297 if (delegation
== NULL
)
299 return nfs_detach_delegation(nfsi
, delegation
, server
);
303 * nfs_inode_set_delegation - set up a delegation on an inode
304 * @inode: inode to which delegation applies
305 * @cred: cred to use for subsequent delegation processing
306 * @res: new delegation state from server
308 * Returns zero on success, or a negative errno value.
310 int nfs_inode_set_delegation(struct inode
*inode
, struct rpc_cred
*cred
, struct nfs_openres
*res
)
312 struct nfs_server
*server
= NFS_SERVER(inode
);
313 struct nfs_client
*clp
= server
->nfs_client
;
314 struct nfs_inode
*nfsi
= NFS_I(inode
);
315 struct nfs_delegation
*delegation
, *old_delegation
;
316 struct nfs_delegation
*freeme
= NULL
;
319 delegation
= kmalloc(sizeof(*delegation
), GFP_NOFS
);
320 if (delegation
== NULL
)
322 nfs4_stateid_copy(&delegation
->stateid
, &res
->delegation
);
323 delegation
->type
= res
->delegation_type
;
324 delegation
->maxsize
= res
->maxsize
;
325 delegation
->change_attr
= inode
->i_version
;
326 delegation
->cred
= get_rpccred(cred
);
327 delegation
->inode
= inode
;
328 delegation
->flags
= 1<<NFS_DELEGATION_REFERENCED
;
329 spin_lock_init(&delegation
->lock
);
331 spin_lock(&clp
->cl_lock
);
332 old_delegation
= rcu_dereference_protected(nfsi
->delegation
,
333 lockdep_is_held(&clp
->cl_lock
));
334 if (old_delegation
!= NULL
) {
335 if (nfs4_stateid_match(&delegation
->stateid
,
336 &old_delegation
->stateid
) &&
337 delegation
->type
== old_delegation
->type
) {
341 * Deal with broken servers that hand out two
342 * delegations for the same file.
343 * Allow for upgrades to a WRITE delegation, but
346 dfprintk(FILE, "%s: server %s handed out "
347 "a duplicate delegation!\n",
348 __func__
, clp
->cl_hostname
);
349 if (delegation
->type
== old_delegation
->type
||
350 !(delegation
->type
& FMODE_WRITE
)) {
355 freeme
= nfs_detach_delegation_locked(nfsi
,
356 old_delegation
, clp
);
360 list_add_rcu(&delegation
->super_list
, &server
->delegations
);
361 nfsi
->delegation_state
= delegation
->type
;
362 rcu_assign_pointer(nfsi
->delegation
, delegation
);
365 /* Ensure we revalidate the attributes and page cache! */
366 spin_lock(&inode
->i_lock
);
367 nfsi
->cache_validity
|= NFS_INO_REVAL_FORCED
;
368 spin_unlock(&inode
->i_lock
);
369 trace_nfs4_set_delegation(inode
, res
->delegation_type
);
372 spin_unlock(&clp
->cl_lock
);
373 if (delegation
!= NULL
)
374 nfs_free_delegation(delegation
);
376 nfs_do_return_delegation(inode
, freeme
, 0);
381 * Basic procedure for returning a delegation to the server
383 static int nfs_end_delegation_return(struct inode
*inode
, struct nfs_delegation
*delegation
, int issync
)
385 struct nfs_client
*clp
= NFS_SERVER(inode
)->nfs_client
;
386 struct nfs_inode
*nfsi
= NFS_I(inode
);
389 if (delegation
== NULL
)
392 if (test_bit(NFS_DELEGATION_REVOKED
, &delegation
->flags
))
394 err
= nfs_delegation_claim_opens(inode
, &delegation
->stateid
);
395 if (!issync
|| err
!= -EAGAIN
)
398 * Guard against state recovery
400 err
= nfs4_wait_clnt_recover(clp
);
404 nfs_abort_delegation_return(delegation
, clp
);
407 if (!nfs_detach_delegation(nfsi
, delegation
, NFS_SERVER(inode
)))
410 err
= nfs_do_return_delegation(inode
, delegation
, issync
);
415 static bool nfs_delegation_need_return(struct nfs_delegation
*delegation
)
419 if (test_and_clear_bit(NFS_DELEGATION_RETURN
, &delegation
->flags
))
421 if (test_and_clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED
, &delegation
->flags
) && !ret
) {
424 spin_lock(&delegation
->lock
);
425 inode
= delegation
->inode
;
426 if (inode
&& list_empty(&NFS_I(inode
)->open_files
))
428 spin_unlock(&delegation
->lock
);
434 * nfs_client_return_marked_delegations - return previously marked delegations
435 * @clp: nfs_client to process
437 * Note that this function is designed to be called by the state
438 * manager thread. For this reason, it cannot flush the dirty data,
439 * since that could deadlock in case of a state recovery error.
441 * Returns zero on success, or a negative errno value.
443 int nfs_client_return_marked_delegations(struct nfs_client
*clp
)
445 struct nfs_delegation
*delegation
;
446 struct nfs_server
*server
;
452 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
) {
453 list_for_each_entry_rcu(delegation
, &server
->delegations
,
455 if (!nfs_delegation_need_return(delegation
))
457 inode
= nfs_delegation_grab_inode(delegation
);
460 delegation
= nfs_start_delegation_return_locked(NFS_I(inode
));
463 err
= nfs_end_delegation_return(inode
, delegation
, 0);
467 set_bit(NFS4CLNT_DELEGRETURN
, &clp
->cl_state
);
476 * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
477 * @inode: inode to process
479 * Does not protect against delegation reclaims, therefore really only safe
480 * to be called from nfs4_clear_inode().
482 void nfs_inode_return_delegation_noreclaim(struct inode
*inode
)
484 struct nfs_delegation
*delegation
;
486 delegation
= nfs_inode_detach_delegation(inode
);
487 if (delegation
!= NULL
)
488 nfs_do_return_delegation(inode
, delegation
, 0);
492 * nfs_inode_return_delegation - synchronously return a delegation
493 * @inode: inode to process
495 * This routine will always flush any dirty data to disk on the
496 * assumption that if we need to return the delegation, then
497 * we should stop caching.
499 * Returns zero on success, or a negative errno value.
501 int nfs4_inode_return_delegation(struct inode
*inode
)
503 struct nfs_inode
*nfsi
= NFS_I(inode
);
504 struct nfs_delegation
*delegation
;
508 delegation
= nfs_start_delegation_return(nfsi
);
509 if (delegation
!= NULL
)
510 err
= nfs_end_delegation_return(inode
, delegation
, 1);
514 static void nfs_mark_return_if_closed_delegation(struct nfs_server
*server
,
515 struct nfs_delegation
*delegation
)
517 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED
, &delegation
->flags
);
518 set_bit(NFS4CLNT_DELEGRETURN
, &server
->nfs_client
->cl_state
);
521 static void nfs_mark_return_delegation(struct nfs_server
*server
,
522 struct nfs_delegation
*delegation
)
524 set_bit(NFS_DELEGATION_RETURN
, &delegation
->flags
);
525 set_bit(NFS4CLNT_DELEGRETURN
, &server
->nfs_client
->cl_state
);
528 static bool nfs_server_mark_return_all_delegations(struct nfs_server
*server
)
530 struct nfs_delegation
*delegation
;
533 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
) {
534 nfs_mark_return_delegation(server
, delegation
);
540 static void nfs_client_mark_return_all_delegations(struct nfs_client
*clp
)
542 struct nfs_server
*server
;
545 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
546 nfs_server_mark_return_all_delegations(server
);
550 static void nfs_delegation_run_state_manager(struct nfs_client
*clp
)
552 if (test_bit(NFS4CLNT_DELEGRETURN
, &clp
->cl_state
))
553 nfs4_schedule_state_manager(clp
);
557 * nfs_expire_all_delegations
558 * @clp: client to process
561 void nfs_expire_all_delegations(struct nfs_client
*clp
)
563 nfs_client_mark_return_all_delegations(clp
);
564 nfs_delegation_run_state_manager(clp
);
568 * nfs_super_return_all_delegations - return delegations for one superblock
572 void nfs_server_return_all_delegations(struct nfs_server
*server
)
574 struct nfs_client
*clp
= server
->nfs_client
;
581 need_wait
= nfs_server_mark_return_all_delegations(server
);
585 nfs4_schedule_state_manager(clp
);
586 nfs4_wait_clnt_recover(clp
);
590 static void nfs_mark_return_unused_delegation_types(struct nfs_server
*server
,
593 struct nfs_delegation
*delegation
;
595 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
) {
596 if ((delegation
->type
== (FMODE_READ
|FMODE_WRITE
)) && !(flags
& FMODE_WRITE
))
598 if (delegation
->type
& flags
)
599 nfs_mark_return_if_closed_delegation(server
, delegation
);
603 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client
*clp
,
606 struct nfs_server
*server
;
609 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
610 nfs_mark_return_unused_delegation_types(server
, flags
);
614 static void nfs_revoke_delegation(struct inode
*inode
)
616 struct nfs_delegation
*delegation
;
618 delegation
= rcu_dereference(NFS_I(inode
)->delegation
);
619 if (delegation
!= NULL
) {
620 set_bit(NFS_DELEGATION_REVOKED
, &delegation
->flags
);
621 nfs_mark_return_delegation(NFS_SERVER(inode
), delegation
);
626 void nfs_remove_bad_delegation(struct inode
*inode
)
628 struct nfs_delegation
*delegation
;
630 nfs_revoke_delegation(inode
);
631 delegation
= nfs_inode_detach_delegation(inode
);
633 nfs_inode_find_state_and_recover(inode
, &delegation
->stateid
);
634 nfs_free_delegation(delegation
);
637 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation
);
640 * nfs_expire_unused_delegation_types
641 * @clp: client to process
642 * @flags: delegation types to expire
645 void nfs_expire_unused_delegation_types(struct nfs_client
*clp
, fmode_t flags
)
647 nfs_client_mark_return_unused_delegation_types(clp
, flags
);
648 nfs_delegation_run_state_manager(clp
);
651 static void nfs_mark_return_unreferenced_delegations(struct nfs_server
*server
)
653 struct nfs_delegation
*delegation
;
655 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
) {
656 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED
, &delegation
->flags
))
658 nfs_mark_return_if_closed_delegation(server
, delegation
);
663 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
664 * @clp: nfs_client to process
667 void nfs_expire_unreferenced_delegations(struct nfs_client
*clp
)
669 struct nfs_server
*server
;
672 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
673 nfs_mark_return_unreferenced_delegations(server
);
676 nfs_delegation_run_state_manager(clp
);
680 * nfs_async_inode_return_delegation - asynchronously return a delegation
681 * @inode: inode to process
682 * @stateid: state ID information
684 * Returns zero on success, or a negative errno value.
686 int nfs_async_inode_return_delegation(struct inode
*inode
,
687 const nfs4_stateid
*stateid
)
689 struct nfs_server
*server
= NFS_SERVER(inode
);
690 struct nfs_client
*clp
= server
->nfs_client
;
691 struct nfs_delegation
*delegation
;
693 filemap_flush(inode
->i_mapping
);
696 delegation
= rcu_dereference(NFS_I(inode
)->delegation
);
697 if (delegation
== NULL
)
700 if (!clp
->cl_mvops
->match_stateid(&delegation
->stateid
, stateid
))
702 nfs_mark_return_delegation(server
, delegation
);
705 nfs_delegation_run_state_manager(clp
);
712 static struct inode
*
713 nfs_delegation_find_inode_server(struct nfs_server
*server
,
714 const struct nfs_fh
*fhandle
)
716 struct nfs_delegation
*delegation
;
717 struct inode
*res
= NULL
;
719 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
) {
720 spin_lock(&delegation
->lock
);
721 if (delegation
->inode
!= NULL
&&
722 nfs_compare_fh(fhandle
, &NFS_I(delegation
->inode
)->fh
) == 0) {
723 res
= igrab(delegation
->inode
);
725 spin_unlock(&delegation
->lock
);
733 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
734 * @clp: client state handle
735 * @fhandle: filehandle from a delegation recall
737 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
740 struct inode
*nfs_delegation_find_inode(struct nfs_client
*clp
,
741 const struct nfs_fh
*fhandle
)
743 struct nfs_server
*server
;
744 struct inode
*res
= NULL
;
747 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
) {
748 res
= nfs_delegation_find_inode_server(server
, fhandle
);
756 static void nfs_delegation_mark_reclaim_server(struct nfs_server
*server
)
758 struct nfs_delegation
*delegation
;
760 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
)
761 set_bit(NFS_DELEGATION_NEED_RECLAIM
, &delegation
->flags
);
765 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
766 * @clp: nfs_client to process
769 void nfs_delegation_mark_reclaim(struct nfs_client
*clp
)
771 struct nfs_server
*server
;
774 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
775 nfs_delegation_mark_reclaim_server(server
);
780 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
781 * @clp: nfs_client to process
784 void nfs_delegation_reap_unclaimed(struct nfs_client
*clp
)
786 struct nfs_delegation
*delegation
;
787 struct nfs_server
*server
;
792 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
) {
793 list_for_each_entry_rcu(delegation
, &server
->delegations
,
795 if (test_bit(NFS_DELEGATION_NEED_RECLAIM
,
796 &delegation
->flags
) == 0)
798 inode
= nfs_delegation_grab_inode(delegation
);
801 delegation
= nfs_detach_delegation(NFS_I(inode
),
805 if (delegation
!= NULL
)
806 nfs_free_delegation(delegation
);
815 * nfs_delegations_present - check for existence of delegations
816 * @clp: client state handle
818 * Returns one if there are any nfs_delegation structures attached
819 * to this nfs_client.
821 int nfs_delegations_present(struct nfs_client
*clp
)
823 struct nfs_server
*server
;
827 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
828 if (!list_empty(&server
->delegations
)) {
837 * nfs4_copy_delegation_stateid - Copy inode's state ID information
838 * @dst: stateid data structure to fill in
839 * @inode: inode to check
840 * @flags: delegation type requirement
842 * Returns "true" and fills in "dst->data" * if inode had a delegation,
843 * otherwise "false" is returned.
845 bool nfs4_copy_delegation_stateid(nfs4_stateid
*dst
, struct inode
*inode
,
848 struct nfs_inode
*nfsi
= NFS_I(inode
);
849 struct nfs_delegation
*delegation
;
852 flags
&= FMODE_READ
|FMODE_WRITE
;
854 delegation
= rcu_dereference(nfsi
->delegation
);
855 ret
= (delegation
!= NULL
&& (delegation
->type
& flags
) == flags
);
857 nfs4_stateid_copy(dst
, &delegation
->stateid
);
858 nfs_mark_delegation_referenced(delegation
);