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"
24 static void nfs_free_delegation(struct nfs_delegation
*delegation
)
26 if (delegation
->cred
) {
27 put_rpccred(delegation
->cred
);
28 delegation
->cred
= NULL
;
30 kfree_rcu(delegation
, rcu
);
34 * nfs_mark_delegation_referenced - set delegation's REFERENCED flag
35 * @delegation: delegation to process
38 void nfs_mark_delegation_referenced(struct nfs_delegation
*delegation
)
40 set_bit(NFS_DELEGATION_REFERENCED
, &delegation
->flags
);
44 * nfs_have_delegation - check if inode has a delegation
45 * @inode: inode to check
46 * @flags: delegation types to check for
48 * Returns one if inode has the indicated delegation, otherwise zero.
50 int nfs4_have_delegation(struct inode
*inode
, fmode_t flags
)
52 struct nfs_delegation
*delegation
;
55 flags
&= FMODE_READ
|FMODE_WRITE
;
57 delegation
= rcu_dereference(NFS_I(inode
)->delegation
);
58 if (delegation
!= NULL
&& (delegation
->type
& flags
) == flags
&&
59 !test_bit(NFS_DELEGATION_RETURNING
, &delegation
->flags
)) {
60 nfs_mark_delegation_referenced(delegation
);
67 static int nfs_delegation_claim_locks(struct nfs_open_context
*ctx
, struct nfs4_state
*state
, const nfs4_stateid
*stateid
)
69 struct inode
*inode
= state
->inode
;
73 if (inode
->i_flock
== NULL
)
76 /* Protect inode->i_flock using the i_lock */
77 spin_lock(&inode
->i_lock
);
78 for (fl
= inode
->i_flock
; fl
!= NULL
; fl
= fl
->fl_next
) {
79 if (!(fl
->fl_flags
& (FL_POSIX
|FL_FLOCK
)))
81 if (nfs_file_open_context(fl
->fl_file
) != ctx
)
83 spin_unlock(&inode
->i_lock
);
84 status
= nfs4_lock_delegation_recall(fl
, state
, stateid
);
87 spin_lock(&inode
->i_lock
);
89 spin_unlock(&inode
->i_lock
);
94 static int nfs_delegation_claim_opens(struct inode
*inode
, const nfs4_stateid
*stateid
)
96 struct nfs_inode
*nfsi
= NFS_I(inode
);
97 struct nfs_open_context
*ctx
;
98 struct nfs4_state_owner
*sp
;
99 struct nfs4_state
*state
;
104 spin_lock(&inode
->i_lock
);
105 list_for_each_entry(ctx
, &nfsi
->open_files
, list
) {
109 if (!test_bit(NFS_DELEGATED_STATE
, &state
->flags
))
111 if (!nfs4_stateid_match(&state
->stateid
, stateid
))
113 get_nfs_open_context(ctx
);
114 spin_unlock(&inode
->i_lock
);
116 /* Block nfs4_proc_unlck */
117 mutex_lock(&sp
->so_delegreturn_mutex
);
118 seq
= raw_seqcount_begin(&sp
->so_reclaim_seqcount
);
119 err
= nfs4_open_delegation_recall(ctx
, state
, stateid
);
121 err
= nfs_delegation_claim_locks(ctx
, state
, stateid
);
122 if (!err
&& read_seqcount_retry(&sp
->so_reclaim_seqcount
, seq
))
124 mutex_unlock(&sp
->so_delegreturn_mutex
);
125 put_nfs_open_context(ctx
);
130 spin_unlock(&inode
->i_lock
);
135 * nfs_inode_reclaim_delegation - process a delegation reclaim request
136 * @inode: inode to process
137 * @cred: credential to use for request
138 * @res: new delegation state from server
141 void nfs_inode_reclaim_delegation(struct inode
*inode
, struct rpc_cred
*cred
,
142 struct nfs_openres
*res
)
144 struct nfs_delegation
*delegation
;
145 struct rpc_cred
*oldcred
= NULL
;
148 delegation
= rcu_dereference(NFS_I(inode
)->delegation
);
149 if (delegation
!= NULL
) {
150 spin_lock(&delegation
->lock
);
151 if (delegation
->inode
!= NULL
) {
152 nfs4_stateid_copy(&delegation
->stateid
, &res
->delegation
);
153 delegation
->type
= res
->delegation_type
;
154 delegation
->maxsize
= res
->maxsize
;
155 oldcred
= delegation
->cred
;
156 delegation
->cred
= get_rpccred(cred
);
157 clear_bit(NFS_DELEGATION_NEED_RECLAIM
,
159 NFS_I(inode
)->delegation_state
= delegation
->type
;
160 spin_unlock(&delegation
->lock
);
161 put_rpccred(oldcred
);
164 /* We appear to have raced with a delegation return. */
165 spin_unlock(&delegation
->lock
);
167 nfs_inode_set_delegation(inode
, cred
, res
);
174 static int nfs_do_return_delegation(struct inode
*inode
, struct nfs_delegation
*delegation
, int issync
)
178 res
= nfs4_proc_delegreturn(inode
, delegation
->cred
, &delegation
->stateid
, issync
);
179 nfs_free_delegation(delegation
);
183 static struct inode
*nfs_delegation_grab_inode(struct nfs_delegation
*delegation
)
185 struct inode
*inode
= NULL
;
187 spin_lock(&delegation
->lock
);
188 if (delegation
->inode
!= NULL
)
189 inode
= igrab(delegation
->inode
);
190 spin_unlock(&delegation
->lock
);
194 static struct nfs_delegation
*
195 nfs_start_delegation_return_locked(struct nfs_inode
*nfsi
)
197 struct nfs_delegation
*ret
= NULL
;
198 struct nfs_delegation
*delegation
= rcu_dereference(nfsi
->delegation
);
200 if (delegation
== NULL
)
202 spin_lock(&delegation
->lock
);
203 if (!test_and_set_bit(NFS_DELEGATION_RETURNING
, &delegation
->flags
))
205 spin_unlock(&delegation
->lock
);
210 static struct nfs_delegation
*
211 nfs_start_delegation_return(struct nfs_inode
*nfsi
)
213 struct nfs_delegation
*delegation
;
216 delegation
= nfs_start_delegation_return_locked(nfsi
);
222 nfs_abort_delegation_return(struct nfs_delegation
*delegation
,
223 struct nfs_client
*clp
)
226 spin_lock(&delegation
->lock
);
227 clear_bit(NFS_DELEGATION_RETURNING
, &delegation
->flags
);
228 set_bit(NFS_DELEGATION_RETURN
, &delegation
->flags
);
229 spin_unlock(&delegation
->lock
);
230 set_bit(NFS4CLNT_DELEGRETURN
, &clp
->cl_state
);
233 static struct nfs_delegation
*
234 nfs_detach_delegation_locked(struct nfs_inode
*nfsi
,
235 struct nfs_delegation
*delegation
,
236 struct nfs_client
*clp
)
238 struct nfs_delegation
*deleg_cur
=
239 rcu_dereference_protected(nfsi
->delegation
,
240 lockdep_is_held(&clp
->cl_lock
));
242 if (deleg_cur
== NULL
|| delegation
!= deleg_cur
)
245 spin_lock(&delegation
->lock
);
246 set_bit(NFS_DELEGATION_RETURNING
, &delegation
->flags
);
247 list_del_rcu(&delegation
->super_list
);
248 delegation
->inode
= NULL
;
249 nfsi
->delegation_state
= 0;
250 rcu_assign_pointer(nfsi
->delegation
, NULL
);
251 spin_unlock(&delegation
->lock
);
255 static struct nfs_delegation
*nfs_detach_delegation(struct nfs_inode
*nfsi
,
256 struct nfs_delegation
*delegation
,
257 struct nfs_server
*server
)
259 struct nfs_client
*clp
= server
->nfs_client
;
261 spin_lock(&clp
->cl_lock
);
262 delegation
= nfs_detach_delegation_locked(nfsi
, delegation
, clp
);
263 spin_unlock(&clp
->cl_lock
);
267 static struct nfs_delegation
*
268 nfs_inode_detach_delegation(struct inode
*inode
)
270 struct nfs_inode
*nfsi
= NFS_I(inode
);
271 struct nfs_server
*server
= NFS_SERVER(inode
);
272 struct nfs_delegation
*delegation
;
274 delegation
= nfs_start_delegation_return(nfsi
);
275 if (delegation
== NULL
)
277 return nfs_detach_delegation(nfsi
, delegation
, server
);
281 * nfs_inode_set_delegation - set up a delegation on an inode
282 * @inode: inode to which delegation applies
283 * @cred: cred to use for subsequent delegation processing
284 * @res: new delegation state from server
286 * Returns zero on success, or a negative errno value.
288 int nfs_inode_set_delegation(struct inode
*inode
, struct rpc_cred
*cred
, struct nfs_openres
*res
)
290 struct nfs_server
*server
= NFS_SERVER(inode
);
291 struct nfs_client
*clp
= server
->nfs_client
;
292 struct nfs_inode
*nfsi
= NFS_I(inode
);
293 struct nfs_delegation
*delegation
, *old_delegation
;
294 struct nfs_delegation
*freeme
= NULL
;
297 delegation
= kmalloc(sizeof(*delegation
), GFP_NOFS
);
298 if (delegation
== NULL
)
300 nfs4_stateid_copy(&delegation
->stateid
, &res
->delegation
);
301 delegation
->type
= res
->delegation_type
;
302 delegation
->maxsize
= res
->maxsize
;
303 delegation
->change_attr
= inode
->i_version
;
304 delegation
->cred
= get_rpccred(cred
);
305 delegation
->inode
= inode
;
306 delegation
->flags
= 1<<NFS_DELEGATION_REFERENCED
;
307 spin_lock_init(&delegation
->lock
);
309 spin_lock(&clp
->cl_lock
);
310 old_delegation
= rcu_dereference_protected(nfsi
->delegation
,
311 lockdep_is_held(&clp
->cl_lock
));
312 if (old_delegation
!= NULL
) {
313 if (nfs4_stateid_match(&delegation
->stateid
,
314 &old_delegation
->stateid
) &&
315 delegation
->type
== old_delegation
->type
) {
319 * Deal with broken servers that hand out two
320 * delegations for the same file.
321 * Allow for upgrades to a WRITE delegation, but
324 dfprintk(FILE, "%s: server %s handed out "
325 "a duplicate delegation!\n",
326 __func__
, clp
->cl_hostname
);
327 if (delegation
->type
== old_delegation
->type
||
328 !(delegation
->type
& FMODE_WRITE
)) {
333 freeme
= nfs_detach_delegation_locked(nfsi
,
334 old_delegation
, clp
);
338 list_add_rcu(&delegation
->super_list
, &server
->delegations
);
339 nfsi
->delegation_state
= delegation
->type
;
340 rcu_assign_pointer(nfsi
->delegation
, delegation
);
343 /* Ensure we revalidate the attributes and page cache! */
344 spin_lock(&inode
->i_lock
);
345 nfsi
->cache_validity
|= NFS_INO_REVAL_FORCED
;
346 spin_unlock(&inode
->i_lock
);
349 spin_unlock(&clp
->cl_lock
);
350 if (delegation
!= NULL
)
351 nfs_free_delegation(delegation
);
353 nfs_do_return_delegation(inode
, freeme
, 0);
358 * Basic procedure for returning a delegation to the server
360 static int nfs_end_delegation_return(struct inode
*inode
, struct nfs_delegation
*delegation
, int issync
)
362 struct nfs_client
*clp
= NFS_SERVER(inode
)->nfs_client
;
363 struct nfs_inode
*nfsi
= NFS_I(inode
);
366 if (delegation
== NULL
)
369 err
= nfs_delegation_claim_opens(inode
, &delegation
->stateid
);
370 if (!issync
|| err
!= -EAGAIN
)
373 * Guard against state recovery
375 err
= nfs4_wait_clnt_recover(clp
);
379 nfs_abort_delegation_return(delegation
, clp
);
382 if (!nfs_detach_delegation(nfsi
, delegation
, NFS_SERVER(inode
)))
385 err
= nfs_do_return_delegation(inode
, delegation
, issync
);
390 static bool nfs_delegation_need_return(struct nfs_delegation
*delegation
)
394 if (test_and_clear_bit(NFS_DELEGATION_RETURN
, &delegation
->flags
))
396 if (test_and_clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED
, &delegation
->flags
) && !ret
) {
399 spin_lock(&delegation
->lock
);
400 inode
= delegation
->inode
;
401 if (inode
&& list_empty(&NFS_I(inode
)->open_files
))
403 spin_unlock(&delegation
->lock
);
409 * nfs_client_return_marked_delegations - return previously marked delegations
410 * @clp: nfs_client to process
412 * Note that this function is designed to be called by the state
413 * manager thread. For this reason, it cannot flush the dirty data,
414 * since that could deadlock in case of a state recovery error.
416 * Returns zero on success, or a negative errno value.
418 int nfs_client_return_marked_delegations(struct nfs_client
*clp
)
420 struct nfs_delegation
*delegation
;
421 struct nfs_server
*server
;
427 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
) {
428 list_for_each_entry_rcu(delegation
, &server
->delegations
,
430 if (!nfs_delegation_need_return(delegation
))
432 inode
= nfs_delegation_grab_inode(delegation
);
435 delegation
= nfs_start_delegation_return_locked(NFS_I(inode
));
438 err
= nfs_end_delegation_return(inode
, delegation
, 0);
442 set_bit(NFS4CLNT_DELEGRETURN
, &clp
->cl_state
);
451 * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
452 * @inode: inode to process
454 * Does not protect against delegation reclaims, therefore really only safe
455 * to be called from nfs4_clear_inode().
457 void nfs_inode_return_delegation_noreclaim(struct inode
*inode
)
459 struct nfs_delegation
*delegation
;
461 delegation
= nfs_inode_detach_delegation(inode
);
462 if (delegation
!= NULL
)
463 nfs_do_return_delegation(inode
, delegation
, 0);
467 * nfs_inode_return_delegation - synchronously return a delegation
468 * @inode: inode to process
470 * This routine will always flush any dirty data to disk on the
471 * assumption that if we need to return the delegation, then
472 * we should stop caching.
474 * Returns zero on success, or a negative errno value.
476 int nfs4_inode_return_delegation(struct inode
*inode
)
478 struct nfs_inode
*nfsi
= NFS_I(inode
);
479 struct nfs_delegation
*delegation
;
483 delegation
= nfs_start_delegation_return(nfsi
);
484 if (delegation
!= NULL
)
485 err
= nfs_end_delegation_return(inode
, delegation
, 1);
489 static void nfs_mark_return_if_closed_delegation(struct nfs_server
*server
,
490 struct nfs_delegation
*delegation
)
492 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED
, &delegation
->flags
);
493 set_bit(NFS4CLNT_DELEGRETURN
, &server
->nfs_client
->cl_state
);
496 static void nfs_mark_return_delegation(struct nfs_server
*server
,
497 struct nfs_delegation
*delegation
)
499 set_bit(NFS_DELEGATION_RETURN
, &delegation
->flags
);
500 set_bit(NFS4CLNT_DELEGRETURN
, &server
->nfs_client
->cl_state
);
503 static bool nfs_server_mark_return_all_delegations(struct nfs_server
*server
)
505 struct nfs_delegation
*delegation
;
508 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
) {
509 nfs_mark_return_delegation(server
, delegation
);
515 static void nfs_client_mark_return_all_delegations(struct nfs_client
*clp
)
517 struct nfs_server
*server
;
520 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
521 nfs_server_mark_return_all_delegations(server
);
525 static void nfs_delegation_run_state_manager(struct nfs_client
*clp
)
527 if (test_bit(NFS4CLNT_DELEGRETURN
, &clp
->cl_state
))
528 nfs4_schedule_state_manager(clp
);
532 * nfs_expire_all_delegations
533 * @clp: client to process
536 void nfs_expire_all_delegations(struct nfs_client
*clp
)
538 nfs_client_mark_return_all_delegations(clp
);
539 nfs_delegation_run_state_manager(clp
);
543 * nfs_super_return_all_delegations - return delegations for one superblock
547 void nfs_server_return_all_delegations(struct nfs_server
*server
)
549 struct nfs_client
*clp
= server
->nfs_client
;
556 need_wait
= nfs_server_mark_return_all_delegations(server
);
560 nfs4_schedule_state_manager(clp
);
561 nfs4_wait_clnt_recover(clp
);
565 static void nfs_mark_return_unused_delegation_types(struct nfs_server
*server
,
568 struct nfs_delegation
*delegation
;
570 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
) {
571 if ((delegation
->type
== (FMODE_READ
|FMODE_WRITE
)) && !(flags
& FMODE_WRITE
))
573 if (delegation
->type
& flags
)
574 nfs_mark_return_if_closed_delegation(server
, delegation
);
578 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client
*clp
,
581 struct nfs_server
*server
;
584 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
585 nfs_mark_return_unused_delegation_types(server
, flags
);
589 void nfs_remove_bad_delegation(struct inode
*inode
)
591 struct nfs_delegation
*delegation
;
593 delegation
= nfs_inode_detach_delegation(inode
);
595 nfs_inode_find_state_and_recover(inode
, &delegation
->stateid
);
596 nfs_free_delegation(delegation
);
599 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation
);
602 * nfs_expire_unused_delegation_types
603 * @clp: client to process
604 * @flags: delegation types to expire
607 void nfs_expire_unused_delegation_types(struct nfs_client
*clp
, fmode_t flags
)
609 nfs_client_mark_return_unused_delegation_types(clp
, flags
);
610 nfs_delegation_run_state_manager(clp
);
613 static void nfs_mark_return_unreferenced_delegations(struct nfs_server
*server
)
615 struct nfs_delegation
*delegation
;
617 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
) {
618 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED
, &delegation
->flags
))
620 nfs_mark_return_if_closed_delegation(server
, delegation
);
625 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
626 * @clp: nfs_client to process
629 void nfs_expire_unreferenced_delegations(struct nfs_client
*clp
)
631 struct nfs_server
*server
;
634 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
635 nfs_mark_return_unreferenced_delegations(server
);
638 nfs_delegation_run_state_manager(clp
);
642 * nfs_async_inode_return_delegation - asynchronously return a delegation
643 * @inode: inode to process
644 * @stateid: state ID information
646 * Returns zero on success, or a negative errno value.
648 int nfs_async_inode_return_delegation(struct inode
*inode
,
649 const nfs4_stateid
*stateid
)
651 struct nfs_server
*server
= NFS_SERVER(inode
);
652 struct nfs_client
*clp
= server
->nfs_client
;
653 struct nfs_delegation
*delegation
;
655 filemap_flush(inode
->i_mapping
);
658 delegation
= rcu_dereference(NFS_I(inode
)->delegation
);
660 if (!clp
->cl_mvops
->match_stateid(&delegation
->stateid
, stateid
)) {
664 nfs_mark_return_delegation(server
, delegation
);
667 nfs_delegation_run_state_manager(clp
);
671 static struct inode
*
672 nfs_delegation_find_inode_server(struct nfs_server
*server
,
673 const struct nfs_fh
*fhandle
)
675 struct nfs_delegation
*delegation
;
676 struct inode
*res
= NULL
;
678 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
) {
679 spin_lock(&delegation
->lock
);
680 if (delegation
->inode
!= NULL
&&
681 nfs_compare_fh(fhandle
, &NFS_I(delegation
->inode
)->fh
) == 0) {
682 res
= igrab(delegation
->inode
);
684 spin_unlock(&delegation
->lock
);
692 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
693 * @clp: client state handle
694 * @fhandle: filehandle from a delegation recall
696 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
699 struct inode
*nfs_delegation_find_inode(struct nfs_client
*clp
,
700 const struct nfs_fh
*fhandle
)
702 struct nfs_server
*server
;
703 struct inode
*res
= NULL
;
706 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
) {
707 res
= nfs_delegation_find_inode_server(server
, fhandle
);
715 static void nfs_delegation_mark_reclaim_server(struct nfs_server
*server
)
717 struct nfs_delegation
*delegation
;
719 list_for_each_entry_rcu(delegation
, &server
->delegations
, super_list
)
720 set_bit(NFS_DELEGATION_NEED_RECLAIM
, &delegation
->flags
);
724 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
725 * @clp: nfs_client to process
728 void nfs_delegation_mark_reclaim(struct nfs_client
*clp
)
730 struct nfs_server
*server
;
733 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
734 nfs_delegation_mark_reclaim_server(server
);
739 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
740 * @clp: nfs_client to process
743 void nfs_delegation_reap_unclaimed(struct nfs_client
*clp
)
745 struct nfs_delegation
*delegation
;
746 struct nfs_server
*server
;
751 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
) {
752 list_for_each_entry_rcu(delegation
, &server
->delegations
,
754 if (test_bit(NFS_DELEGATION_NEED_RECLAIM
,
755 &delegation
->flags
) == 0)
757 inode
= nfs_delegation_grab_inode(delegation
);
760 delegation
= nfs_detach_delegation(NFS_I(inode
),
764 if (delegation
!= NULL
)
765 nfs_free_delegation(delegation
);
774 * nfs_delegations_present - check for existence of delegations
775 * @clp: client state handle
777 * Returns one if there are any nfs_delegation structures attached
778 * to this nfs_client.
780 int nfs_delegations_present(struct nfs_client
*clp
)
782 struct nfs_server
*server
;
786 list_for_each_entry_rcu(server
, &clp
->cl_superblocks
, client_link
)
787 if (!list_empty(&server
->delegations
)) {
796 * nfs4_copy_delegation_stateid - Copy inode's state ID information
797 * @dst: stateid data structure to fill in
798 * @inode: inode to check
799 * @flags: delegation type requirement
801 * Returns "true" and fills in "dst->data" * if inode had a delegation,
802 * otherwise "false" is returned.
804 bool nfs4_copy_delegation_stateid(nfs4_stateid
*dst
, struct inode
*inode
,
807 struct nfs_inode
*nfsi
= NFS_I(inode
);
808 struct nfs_delegation
*delegation
;
811 flags
&= FMODE_READ
|FMODE_WRITE
;
813 delegation
= rcu_dereference(nfsi
->delegation
);
814 ret
= (delegation
!= NULL
&& (delegation
->type
& flags
) == flags
);
816 nfs4_stateid_copy(dst
, &delegation
->stateid
);
817 nfs_mark_delegation_referenced(delegation
);