1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/fs/nfs/delegation.c
5 * Copyright (C) 2004 Trond Myklebust
7 * NFS file delegation management
10 #include <linux/completion.h>
11 #include <linux/kthread.h>
12 #include <linux/module.h>
13 #include <linux/sched.h>
14 #include <linux/slab.h>
15 #include <linux/spinlock.h>
16 #include <linux/iversion.h>
18 #include <linux/nfs4.h>
19 #include <linux/nfs_fs.h>
20 #include <linux/nfs_xdr.h>
23 #include "nfs4session.h"
24 #include "delegation.h"
26 #include "nfs4trace.h"
28 #define NFS_DEFAULT_DELEGATION_WATERMARK (5000U)
30 static atomic_long_t nfs_active_delegations;
31 static unsigned nfs_delegation_watermark = NFS_DEFAULT_DELEGATION_WATERMARK;
33 static void __nfs_free_delegation(struct nfs_delegation *delegation)
35 put_cred(delegation->cred);
36 delegation->cred = NULL;
37 kfree_rcu(delegation, rcu);
40 static void nfs_mark_delegation_revoked(struct nfs_delegation *delegation)
42 if (!test_and_set_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
43 delegation->stateid.type = NFS4_INVALID_STATEID_TYPE;
44 atomic_long_dec(&nfs_active_delegations);
45 if (!test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
46 nfs_clear_verifier_delegated(delegation->inode);
50 static struct nfs_delegation *nfs_get_delegation(struct nfs_delegation *delegation)
52 refcount_inc(&delegation->refcount);
56 static void nfs_put_delegation(struct nfs_delegation *delegation)
58 if (refcount_dec_and_test(&delegation->refcount))
59 __nfs_free_delegation(delegation);
62 static void nfs_free_delegation(struct nfs_delegation *delegation)
64 nfs_mark_delegation_revoked(delegation);
65 nfs_put_delegation(delegation);
69 * nfs_mark_delegation_referenced - set delegation's REFERENCED flag
70 * @delegation: delegation to process
73 void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
75 set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
78 static void nfs_mark_return_delegation(struct nfs_server *server,
79 struct nfs_delegation *delegation)
81 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
82 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
86 nfs4_is_valid_delegation(const struct nfs_delegation *delegation,
89 if (delegation != NULL && (delegation->type & flags) == flags &&
90 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
91 !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
96 struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode)
98 struct nfs_delegation *delegation;
100 delegation = rcu_dereference(NFS_I(inode)->delegation);
101 if (nfs4_is_valid_delegation(delegation, 0))
107 nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark)
109 struct nfs_delegation *delegation;
112 flags &= FMODE_READ|FMODE_WRITE;
114 delegation = rcu_dereference(NFS_I(inode)->delegation);
115 if (nfs4_is_valid_delegation(delegation, flags)) {
117 nfs_mark_delegation_referenced(delegation);
124 * nfs4_have_delegation - check if inode has a delegation, mark it
125 * NFS_DELEGATION_REFERENCED if there is one.
126 * @inode: inode to check
127 * @flags: delegation types to check for
129 * Returns one if inode has the indicated delegation, otherwise zero.
131 int nfs4_have_delegation(struct inode *inode, fmode_t flags)
133 return nfs4_do_check_delegation(inode, flags, true);
137 * nfs4_check_delegation - check if inode has a delegation, do not mark
138 * NFS_DELEGATION_REFERENCED if it has one.
140 int nfs4_check_delegation(struct inode *inode, fmode_t flags)
142 return nfs4_do_check_delegation(inode, flags, false);
145 static int nfs_delegation_claim_locks(struct nfs4_state *state, const nfs4_stateid *stateid)
147 struct inode *inode = state->inode;
148 struct file_lock *fl;
149 struct file_lock_context *flctx = inode->i_flctx;
150 struct list_head *list;
156 list = &flctx->flc_posix;
157 spin_lock(&flctx->flc_lock);
159 list_for_each_entry(fl, list, fl_list) {
160 if (nfs_file_open_context(fl->fl_file)->state != state)
162 spin_unlock(&flctx->flc_lock);
163 status = nfs4_lock_delegation_recall(fl, state, stateid);
166 spin_lock(&flctx->flc_lock);
168 if (list == &flctx->flc_posix) {
169 list = &flctx->flc_flock;
172 spin_unlock(&flctx->flc_lock);
177 static int nfs_delegation_claim_opens(struct inode *inode,
178 const nfs4_stateid *stateid, fmode_t type)
180 struct nfs_inode *nfsi = NFS_I(inode);
181 struct nfs_open_context *ctx;
182 struct nfs4_state_owner *sp;
183 struct nfs4_state *state;
189 list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
193 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
195 if (!nfs4_valid_open_stateid(state))
197 if (!nfs4_stateid_match(&state->stateid, stateid))
199 if (!get_nfs_open_context(ctx))
203 /* Block nfs4_proc_unlck */
204 mutex_lock(&sp->so_delegreturn_mutex);
205 seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
206 err = nfs4_open_delegation_recall(ctx, state, stateid);
208 err = nfs_delegation_claim_locks(state, stateid);
209 if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
211 mutex_unlock(&sp->so_delegreturn_mutex);
212 put_nfs_open_context(ctx);
222 * nfs_inode_reclaim_delegation - process a delegation reclaim request
223 * @inode: inode to process
224 * @cred: credential to use for request
225 * @type: delegation type
226 * @stateid: delegation stateid
227 * @pagemod_limit: write delegation "space_limit"
230 void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred,
232 const nfs4_stateid *stateid,
233 unsigned long pagemod_limit)
235 struct nfs_delegation *delegation;
236 const struct cred *oldcred = NULL;
239 delegation = rcu_dereference(NFS_I(inode)->delegation);
240 if (delegation != NULL) {
241 spin_lock(&delegation->lock);
242 if (nfs4_is_valid_delegation(delegation, 0)) {
243 nfs4_stateid_copy(&delegation->stateid, stateid);
244 delegation->type = type;
245 delegation->pagemod_limit = pagemod_limit;
246 oldcred = delegation->cred;
247 delegation->cred = get_cred(cred);
248 clear_bit(NFS_DELEGATION_NEED_RECLAIM,
250 spin_unlock(&delegation->lock);
253 trace_nfs4_reclaim_delegation(inode, type);
256 /* We appear to have raced with a delegation return. */
257 spin_unlock(&delegation->lock);
260 nfs_inode_set_delegation(inode, cred, type, stateid, pagemod_limit);
263 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
265 const struct cred *cred;
268 if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
269 spin_lock(&delegation->lock);
270 cred = get_cred(delegation->cred);
271 spin_unlock(&delegation->lock);
272 res = nfs4_proc_delegreturn(inode, cred,
273 &delegation->stateid,
280 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
282 struct inode *inode = NULL;
284 spin_lock(&delegation->lock);
285 if (delegation->inode != NULL)
286 inode = igrab(delegation->inode);
288 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags);
289 spin_unlock(&delegation->lock);
293 static struct nfs_delegation *
294 nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
296 struct nfs_delegation *ret = NULL;
297 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
299 if (delegation == NULL)
301 spin_lock(&delegation->lock);
302 if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
303 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags);
304 /* Refcount matched in nfs_end_delegation_return() */
305 ret = nfs_get_delegation(delegation);
307 spin_unlock(&delegation->lock);
309 nfs_clear_verifier_delegated(&nfsi->vfs_inode);
314 static struct nfs_delegation *
315 nfs_start_delegation_return(struct nfs_inode *nfsi)
317 struct nfs_delegation *delegation;
320 delegation = nfs_start_delegation_return_locked(nfsi);
325 static void nfs_abort_delegation_return(struct nfs_delegation *delegation,
326 struct nfs_client *clp, int err)
329 spin_lock(&delegation->lock);
330 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
331 if (err == -EAGAIN) {
332 set_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags);
333 set_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state);
335 spin_unlock(&delegation->lock);
338 static struct nfs_delegation *
339 nfs_detach_delegation_locked(struct nfs_inode *nfsi,
340 struct nfs_delegation *delegation,
341 struct nfs_client *clp)
343 struct nfs_delegation *deleg_cur =
344 rcu_dereference_protected(nfsi->delegation,
345 lockdep_is_held(&clp->cl_lock));
347 if (deleg_cur == NULL || delegation != deleg_cur)
350 spin_lock(&delegation->lock);
351 if (!delegation->inode) {
352 spin_unlock(&delegation->lock);
355 list_del_rcu(&delegation->super_list);
356 delegation->inode = NULL;
357 rcu_assign_pointer(nfsi->delegation, NULL);
358 spin_unlock(&delegation->lock);
362 static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
363 struct nfs_delegation *delegation,
364 struct nfs_server *server)
366 struct nfs_client *clp = server->nfs_client;
368 spin_lock(&clp->cl_lock);
369 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp);
370 spin_unlock(&clp->cl_lock);
374 static struct nfs_delegation *
375 nfs_inode_detach_delegation(struct inode *inode)
377 struct nfs_inode *nfsi = NFS_I(inode);
378 struct nfs_server *server = NFS_SERVER(inode);
379 struct nfs_delegation *delegation;
382 delegation = rcu_dereference(nfsi->delegation);
383 if (delegation != NULL)
384 delegation = nfs_detach_delegation(nfsi, delegation, server);
390 nfs_update_delegation_cred(struct nfs_delegation *delegation,
391 const struct cred *cred)
393 const struct cred *old;
395 if (cred_fscmp(delegation->cred, cred) != 0) {
396 old = xchg(&delegation->cred, get_cred(cred));
402 nfs_update_inplace_delegation(struct nfs_delegation *delegation,
403 const struct nfs_delegation *update)
405 if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) {
406 delegation->stateid.seqid = update->stateid.seqid;
408 delegation->type = update->type;
409 delegation->pagemod_limit = update->pagemod_limit;
410 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
411 delegation->change_attr = update->change_attr;
412 nfs_update_delegation_cred(delegation, update->cred);
413 /* smp_mb__before_atomic() is implicit due to xchg() */
414 clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
415 atomic_long_inc(&nfs_active_delegations);
421 * nfs_inode_set_delegation - set up a delegation on an inode
422 * @inode: inode to which delegation applies
423 * @cred: cred to use for subsequent delegation processing
424 * @type: delegation type
425 * @stateid: delegation stateid
426 * @pagemod_limit: write delegation "space_limit"
428 * Returns zero on success, or a negative errno value.
430 int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
432 const nfs4_stateid *stateid,
433 unsigned long pagemod_limit)
435 struct nfs_server *server = NFS_SERVER(inode);
436 struct nfs_client *clp = server->nfs_client;
437 struct nfs_inode *nfsi = NFS_I(inode);
438 struct nfs_delegation *delegation, *old_delegation;
439 struct nfs_delegation *freeme = NULL;
442 delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
443 if (delegation == NULL)
445 nfs4_stateid_copy(&delegation->stateid, stateid);
446 refcount_set(&delegation->refcount, 1);
447 delegation->type = type;
448 delegation->pagemod_limit = pagemod_limit;
449 delegation->change_attr = inode_peek_iversion_raw(inode);
450 delegation->cred = get_cred(cred);
451 delegation->inode = inode;
452 delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
453 spin_lock_init(&delegation->lock);
455 spin_lock(&clp->cl_lock);
456 old_delegation = rcu_dereference_protected(nfsi->delegation,
457 lockdep_is_held(&clp->cl_lock));
458 if (old_delegation == NULL)
460 /* Is this an update of the existing delegation? */
461 if (nfs4_stateid_match_other(&old_delegation->stateid,
462 &delegation->stateid)) {
463 spin_lock(&old_delegation->lock);
464 nfs_update_inplace_delegation(old_delegation,
466 spin_unlock(&old_delegation->lock);
469 if (!test_bit(NFS_DELEGATION_REVOKED, &old_delegation->flags)) {
471 * Deal with broken servers that hand out two
472 * delegations for the same file.
473 * Allow for upgrades to a WRITE delegation, but
476 dfprintk(FILE, "%s: server %s handed out "
477 "a duplicate delegation!\n",
478 __func__, clp->cl_hostname);
479 if (delegation->type == old_delegation->type ||
480 !(delegation->type & FMODE_WRITE)) {
485 if (test_and_set_bit(NFS_DELEGATION_RETURNING,
486 &old_delegation->flags))
489 freeme = nfs_detach_delegation_locked(nfsi, old_delegation, clp);
494 * If we didn't revalidate the change attribute before setting
495 * the delegation, then pre-emptively ask for a full attribute
496 * cache revalidation.
498 spin_lock(&inode->i_lock);
499 if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_CHANGE)
500 nfs_set_cache_invalid(inode,
501 NFS_INO_INVALID_ATIME | NFS_INO_INVALID_CTIME |
502 NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE |
503 NFS_INO_INVALID_BLOCKS | NFS_INO_INVALID_NLINK |
504 NFS_INO_INVALID_OTHER | NFS_INO_INVALID_DATA |
505 NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL |
506 NFS_INO_INVALID_XATTR);
507 spin_unlock(&inode->i_lock);
509 list_add_tail_rcu(&delegation->super_list, &server->delegations);
510 rcu_assign_pointer(nfsi->delegation, delegation);
513 atomic_long_inc(&nfs_active_delegations);
515 trace_nfs4_set_delegation(inode, type);
517 spin_unlock(&clp->cl_lock);
518 if (delegation != NULL)
519 __nfs_free_delegation(delegation);
520 if (freeme != NULL) {
521 nfs_do_return_delegation(inode, freeme, 0);
522 nfs_free_delegation(freeme);
528 * Basic procedure for returning a delegation to the server
530 static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
532 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
533 unsigned int mode = O_WRONLY | O_RDWR;
536 if (delegation == NULL)
541 /* Recall of any remaining application leases */
542 err = break_lease(inode, mode);
545 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
547 err = nfs_delegation_claim_opens(inode, &delegation->stateid,
549 if (!issync || err != -EAGAIN)
552 * Guard against state recovery
554 err = nfs4_wait_clnt_recover(clp);
558 nfs_abort_delegation_return(delegation, clp, err);
562 err = nfs_do_return_delegation(inode, delegation, issync);
564 /* Refcount matched in nfs_start_delegation_return_locked() */
565 nfs_put_delegation(delegation);
569 static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
573 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
575 else if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags)) {
578 spin_lock(&delegation->lock);
579 inode = delegation->inode;
580 if (inode && list_empty(&NFS_I(inode)->open_files))
582 spin_unlock(&delegation->lock);
585 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
586 if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags) ||
587 test_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags) ||
588 test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
594 static int nfs_server_return_marked_delegations(struct nfs_server *server,
595 void __always_unused *data)
597 struct nfs_delegation *delegation;
598 struct nfs_delegation *prev;
600 struct inode *place_holder = NULL;
601 struct nfs_delegation *place_holder_deleg = NULL;
606 * To avoid quadratic looping we hold a reference
607 * to an inode place_holder. Each time we restart, we
608 * list delegation in the server from the delegations
610 * prev is an RCU-protected pointer to a delegation which
611 * wasn't marked for return and might be a good choice for
612 * the next place_holder.
618 delegation = rcu_dereference(NFS_I(place_holder)->delegation);
619 if (!delegation || delegation != place_holder_deleg)
620 delegation = list_entry_rcu(server->delegations.next,
621 struct nfs_delegation, super_list);
622 list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) {
623 struct inode *to_put = NULL;
625 if (test_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags))
627 if (!nfs_delegation_need_return(delegation)) {
628 if (nfs4_is_valid_delegation(delegation, 0))
634 struct inode *tmp = nfs_delegation_grab_inode(prev);
636 to_put = place_holder;
638 place_holder_deleg = prev;
642 inode = nfs_delegation_grab_inode(delegation);
648 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
653 err = nfs_end_delegation_return(inode, delegation, 0);
658 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
667 static bool nfs_server_clear_delayed_delegations(struct nfs_server *server)
669 struct nfs_delegation *d;
672 list_for_each_entry_rcu (d, &server->delegations, super_list) {
673 if (!test_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags))
675 nfs_mark_return_delegation(server, d);
676 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags);
682 static bool nfs_client_clear_delayed_delegations(struct nfs_client *clp)
684 struct nfs_server *server;
687 if (!test_and_clear_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state))
690 list_for_each_entry_rcu (server, &clp->cl_superblocks, client_link) {
691 if (nfs_server_clear_delayed_delegations(server))
700 * nfs_client_return_marked_delegations - return previously marked delegations
701 * @clp: nfs_client to process
703 * Note that this function is designed to be called by the state
704 * manager thread. For this reason, it cannot flush the dirty data,
705 * since that could deadlock in case of a state recovery error.
707 * Returns zero on success, or a negative errno value.
709 int nfs_client_return_marked_delegations(struct nfs_client *clp)
711 int err = nfs_client_for_each_server(
712 clp, nfs_server_return_marked_delegations, NULL);
715 /* If a return was delayed, sleep to prevent hard looping */
716 if (nfs_client_clear_delayed_delegations(clp))
722 * nfs_inode_evict_delegation - return delegation, don't reclaim opens
723 * @inode: inode to process
725 * Does not protect against delegation reclaims, therefore really only safe
726 * to be called from nfs4_clear_inode(). Guaranteed to always free
727 * the delegation structure.
729 void nfs_inode_evict_delegation(struct inode *inode)
731 struct nfs_delegation *delegation;
733 delegation = nfs_inode_detach_delegation(inode);
734 if (delegation != NULL) {
735 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
736 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags);
737 nfs_do_return_delegation(inode, delegation, 1);
738 nfs_free_delegation(delegation);
743 * nfs4_inode_return_delegation - synchronously return a delegation
744 * @inode: inode to process
746 * This routine will always flush any dirty data to disk on the
747 * assumption that if we need to return the delegation, then
748 * we should stop caching.
750 * Returns zero on success, or a negative errno value.
752 int nfs4_inode_return_delegation(struct inode *inode)
754 struct nfs_inode *nfsi = NFS_I(inode);
755 struct nfs_delegation *delegation;
757 delegation = nfs_start_delegation_return(nfsi);
758 /* Synchronous recall of any application leases */
759 break_lease(inode, O_WRONLY | O_RDWR);
761 if (delegation != NULL)
762 return nfs_end_delegation_return(inode, delegation, 1);
767 * nfs4_inode_return_delegation_on_close - asynchronously return a delegation
768 * @inode: inode to process
770 * This routine is called on file close in order to determine if the
771 * inode delegation needs to be returned immediately.
773 void nfs4_inode_return_delegation_on_close(struct inode *inode)
775 struct nfs_delegation *delegation;
776 struct nfs_delegation *ret = NULL;
781 delegation = nfs4_get_valid_delegation(inode);
784 if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) ||
785 atomic_long_read(&nfs_active_delegations) >= nfs_delegation_watermark) {
786 spin_lock(&delegation->lock);
787 if (delegation->inode &&
788 list_empty(&NFS_I(inode)->open_files) &&
789 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
790 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
791 /* Refcount matched in nfs_end_delegation_return() */
792 ret = nfs_get_delegation(delegation);
794 spin_unlock(&delegation->lock);
796 nfs_clear_verifier_delegated(inode);
800 nfs_end_delegation_return(inode, ret, 0);
804 * nfs4_inode_make_writeable
805 * @inode: pointer to inode
807 * Make the inode writeable by returning the delegation if necessary
809 * Returns zero on success, or a negative errno value.
811 int nfs4_inode_make_writeable(struct inode *inode)
813 struct nfs_delegation *delegation;
816 delegation = nfs4_get_valid_delegation(inode);
817 if (delegation == NULL ||
818 (nfs4_has_session(NFS_SERVER(inode)->nfs_client) &&
819 (delegation->type & FMODE_WRITE))) {
824 return nfs4_inode_return_delegation(inode);
827 static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
828 struct nfs_delegation *delegation)
830 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
831 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
834 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
836 struct nfs_delegation *delegation;
839 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
840 nfs_mark_return_delegation(server, delegation);
846 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
848 struct nfs_server *server;
851 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
852 nfs_server_mark_return_all_delegations(server);
856 static void nfs_delegation_run_state_manager(struct nfs_client *clp)
858 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
859 nfs4_schedule_state_manager(clp);
863 * nfs_expire_all_delegations
864 * @clp: client to process
867 void nfs_expire_all_delegations(struct nfs_client *clp)
869 nfs_client_mark_return_all_delegations(clp);
870 nfs_delegation_run_state_manager(clp);
874 * nfs_server_return_all_delegations - return delegations for one superblock
875 * @server: pointer to nfs_server to process
878 void nfs_server_return_all_delegations(struct nfs_server *server)
880 struct nfs_client *clp = server->nfs_client;
887 need_wait = nfs_server_mark_return_all_delegations(server);
891 nfs4_schedule_state_manager(clp);
892 nfs4_wait_clnt_recover(clp);
896 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server,
899 struct nfs_delegation *delegation;
901 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
902 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
904 if (delegation->type & flags)
905 nfs_mark_return_if_closed_delegation(server, delegation);
909 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp,
912 struct nfs_server *server;
915 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
916 nfs_mark_return_unused_delegation_types(server, flags);
920 static void nfs_revoke_delegation(struct inode *inode,
921 const nfs4_stateid *stateid)
923 struct nfs_delegation *delegation;
928 delegation = rcu_dereference(NFS_I(inode)->delegation);
929 if (delegation == NULL)
931 if (stateid == NULL) {
932 nfs4_stateid_copy(&tmp, &delegation->stateid);
935 if (!nfs4_stateid_match_other(stateid, &delegation->stateid))
937 spin_lock(&delegation->lock);
938 if (stateid->seqid) {
939 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) {
940 spin_unlock(&delegation->lock);
943 delegation->stateid.seqid = stateid->seqid;
945 spin_unlock(&delegation->lock);
947 nfs_mark_delegation_revoked(delegation);
952 nfs_inode_find_state_and_recover(inode, stateid);
955 void nfs_remove_bad_delegation(struct inode *inode,
956 const nfs4_stateid *stateid)
958 nfs_revoke_delegation(inode, stateid);
960 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);
962 void nfs_delegation_mark_returned(struct inode *inode,
963 const nfs4_stateid *stateid)
965 struct nfs_delegation *delegation;
971 delegation = rcu_dereference(NFS_I(inode)->delegation);
975 spin_lock(&delegation->lock);
976 if (!nfs4_stateid_match_other(stateid, &delegation->stateid))
977 goto out_spin_unlock;
978 if (stateid->seqid) {
979 /* If delegation->stateid is newer, dont mark as returned */
980 if (nfs4_stateid_is_newer(&delegation->stateid, stateid))
981 goto out_clear_returning;
982 if (delegation->stateid.seqid != stateid->seqid)
983 delegation->stateid.seqid = stateid->seqid;
986 nfs_mark_delegation_revoked(delegation);
989 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
991 spin_unlock(&delegation->lock);
995 nfs_inode_find_state_and_recover(inode, stateid);
999 * nfs_expire_unused_delegation_types
1000 * @clp: client to process
1001 * @flags: delegation types to expire
1004 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags)
1006 nfs_client_mark_return_unused_delegation_types(clp, flags);
1007 nfs_delegation_run_state_manager(clp);
1010 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
1012 struct nfs_delegation *delegation;
1014 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1015 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
1017 nfs_mark_return_if_closed_delegation(server, delegation);
1022 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
1023 * @clp: nfs_client to process
1026 void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
1028 struct nfs_server *server;
1031 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1032 nfs_mark_return_unreferenced_delegations(server);
1035 nfs_delegation_run_state_manager(clp);
1039 * nfs_async_inode_return_delegation - asynchronously return a delegation
1040 * @inode: inode to process
1041 * @stateid: state ID information
1043 * Returns zero on success, or a negative errno value.
1045 int nfs_async_inode_return_delegation(struct inode *inode,
1046 const nfs4_stateid *stateid)
1048 struct nfs_server *server = NFS_SERVER(inode);
1049 struct nfs_client *clp = server->nfs_client;
1050 struct nfs_delegation *delegation;
1053 delegation = nfs4_get_valid_delegation(inode);
1054 if (delegation == NULL)
1056 if (stateid != NULL &&
1057 !clp->cl_mvops->match_stateid(&delegation->stateid, stateid))
1059 nfs_mark_return_delegation(server, delegation);
1062 /* If there are any application leases or delegations, recall them */
1063 break_lease(inode, O_WRONLY | O_RDWR | O_NONBLOCK);
1065 nfs_delegation_run_state_manager(clp);
1072 static struct inode *
1073 nfs_delegation_find_inode_server(struct nfs_server *server,
1074 const struct nfs_fh *fhandle)
1076 struct nfs_delegation *delegation;
1077 struct super_block *freeme = NULL;
1078 struct inode *res = NULL;
1080 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1081 spin_lock(&delegation->lock);
1082 if (delegation->inode != NULL &&
1083 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
1084 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
1085 if (nfs_sb_active(server->super)) {
1086 freeme = server->super;
1087 res = igrab(delegation->inode);
1089 spin_unlock(&delegation->lock);
1094 nfs_sb_deactive(freeme);
1097 return ERR_PTR(-EAGAIN);
1099 spin_unlock(&delegation->lock);
1101 return ERR_PTR(-ENOENT);
1105 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
1106 * @clp: client state handle
1107 * @fhandle: filehandle from a delegation recall
1109 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
1112 struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
1113 const struct nfs_fh *fhandle)
1115 struct nfs_server *server;
1119 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1120 res = nfs_delegation_find_inode_server(server, fhandle);
1121 if (res != ERR_PTR(-ENOENT)) {
1127 return ERR_PTR(-ENOENT);
1130 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
1132 struct nfs_delegation *delegation;
1134 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1136 * If the delegation may have been admin revoked, then we
1137 * cannot reclaim it.
1139 if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags))
1141 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
1146 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
1147 * @clp: nfs_client to process
1150 void nfs_delegation_mark_reclaim(struct nfs_client *clp)
1152 struct nfs_server *server;
1155 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1156 nfs_delegation_mark_reclaim_server(server);
1160 static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server,
1161 void __always_unused *data)
1163 struct nfs_delegation *delegation;
1164 struct inode *inode;
1168 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1169 if (test_bit(NFS_DELEGATION_INODE_FREEING,
1170 &delegation->flags) ||
1171 test_bit(NFS_DELEGATION_RETURNING,
1172 &delegation->flags) ||
1173 test_bit(NFS_DELEGATION_NEED_RECLAIM,
1174 &delegation->flags) == 0)
1176 inode = nfs_delegation_grab_inode(delegation);
1178 goto restart_locked;
1179 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
1181 if (delegation != NULL) {
1182 if (nfs_detach_delegation(NFS_I(inode), delegation,
1184 nfs_free_delegation(delegation);
1185 /* Match nfs_start_delegation_return_locked */
1186 nfs_put_delegation(delegation);
1197 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
1198 * @clp: nfs_client to process
1201 void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
1203 nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations,
1207 static inline bool nfs4_server_rebooted(const struct nfs_client *clp)
1209 return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) |
1210 BIT(NFS4CLNT_LEASE_EXPIRED) |
1211 BIT(NFS4CLNT_SESSION_RESET))) != 0;
1214 static void nfs_mark_test_expired_delegation(struct nfs_server *server,
1215 struct nfs_delegation *delegation)
1217 if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE)
1219 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
1220 set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
1221 set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state);
1224 static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server,
1225 struct inode *inode)
1227 struct nfs_delegation *delegation;
1230 delegation = rcu_dereference(NFS_I(inode)->delegation);
1232 nfs_mark_test_expired_delegation(server, delegation);
1237 static void nfs_delegation_mark_test_expired_server(struct nfs_server *server)
1239 struct nfs_delegation *delegation;
1241 list_for_each_entry_rcu(delegation, &server->delegations, super_list)
1242 nfs_mark_test_expired_delegation(server, delegation);
1246 * nfs_mark_test_expired_all_delegations - mark all delegations for testing
1247 * @clp: nfs_client to process
1249 * Iterates through all the delegations associated with this server and
1250 * marks them as needing to be checked for validity.
1252 void nfs_mark_test_expired_all_delegations(struct nfs_client *clp)
1254 struct nfs_server *server;
1257 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1258 nfs_delegation_mark_test_expired_server(server);
1263 * nfs_test_expired_all_delegations - test all delegations for a client
1264 * @clp: nfs_client to process
1266 * Helper for handling "recallable state revoked" status from server.
1268 void nfs_test_expired_all_delegations(struct nfs_client *clp)
1270 nfs_mark_test_expired_all_delegations(clp);
1271 nfs4_schedule_state_manager(clp);
1275 nfs_delegation_test_free_expired(struct inode *inode,
1276 nfs4_stateid *stateid,
1277 const struct cred *cred)
1279 struct nfs_server *server = NFS_SERVER(inode);
1280 const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops;
1285 status = ops->test_and_free_expired(server, stateid, cred);
1286 if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID)
1287 nfs_remove_bad_delegation(inode, stateid);
1290 static int nfs_server_reap_expired_delegations(struct nfs_server *server,
1291 void __always_unused *data)
1293 struct nfs_delegation *delegation;
1294 struct inode *inode;
1295 const struct cred *cred;
1296 nfs4_stateid stateid;
1300 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1301 if (test_bit(NFS_DELEGATION_INODE_FREEING,
1302 &delegation->flags) ||
1303 test_bit(NFS_DELEGATION_RETURNING,
1304 &delegation->flags) ||
1305 test_bit(NFS_DELEGATION_TEST_EXPIRED,
1306 &delegation->flags) == 0)
1308 inode = nfs_delegation_grab_inode(delegation);
1310 goto restart_locked;
1311 spin_lock(&delegation->lock);
1312 cred = get_cred_rcu(delegation->cred);
1313 nfs4_stateid_copy(&stateid, &delegation->stateid);
1314 spin_unlock(&delegation->lock);
1315 clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
1317 nfs_delegation_test_free_expired(inode, &stateid, cred);
1319 if (!nfs4_server_rebooted(server->nfs_client)) {
1324 nfs_inode_mark_test_expired_delegation(server,inode);
1333 * nfs_reap_expired_delegations - reap expired delegations
1334 * @clp: nfs_client to process
1336 * Iterates through all the delegations associated with this server and
1337 * checks if they have may have been revoked. This function is usually
1338 * expected to be called in cases where the server may have lost its
1341 void nfs_reap_expired_delegations(struct nfs_client *clp)
1343 nfs_client_for_each_server(clp, nfs_server_reap_expired_delegations,
1347 void nfs_inode_find_delegation_state_and_recover(struct inode *inode,
1348 const nfs4_stateid *stateid)
1350 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1351 struct nfs_delegation *delegation;
1355 delegation = rcu_dereference(NFS_I(inode)->delegation);
1357 nfs4_stateid_match_or_older(&delegation->stateid, stateid) &&
1358 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
1359 nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation);
1364 nfs4_schedule_state_manager(clp);
1368 * nfs_delegations_present - check for existence of delegations
1369 * @clp: client state handle
1371 * Returns one if there are any nfs_delegation structures attached
1372 * to this nfs_client.
1374 int nfs_delegations_present(struct nfs_client *clp)
1376 struct nfs_server *server;
1380 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1381 if (!list_empty(&server->delegations)) {
1390 * nfs4_refresh_delegation_stateid - Update delegation stateid seqid
1391 * @dst: stateid to refresh
1392 * @inode: inode to check
1394 * Returns "true" and updates "dst->seqid" * if inode had a delegation
1395 * that matches our delegation stateid. Otherwise "false" is returned.
1397 bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
1399 struct nfs_delegation *delegation;
1405 delegation = rcu_dereference(NFS_I(inode)->delegation);
1406 if (delegation != NULL &&
1407 nfs4_stateid_match_other(dst, &delegation->stateid) &&
1408 nfs4_stateid_is_newer(&delegation->stateid, dst) &&
1409 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
1410 dst->seqid = delegation->stateid.seqid;
1419 * nfs4_copy_delegation_stateid - Copy inode's state ID information
1420 * @inode: inode to check
1421 * @flags: delegation type requirement
1422 * @dst: stateid data structure to fill in
1423 * @cred: optional argument to retrieve credential
1425 * Returns "true" and fills in "dst->data" * if inode had a delegation,
1426 * otherwise "false" is returned.
1428 bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags,
1429 nfs4_stateid *dst, const struct cred **cred)
1431 struct nfs_inode *nfsi = NFS_I(inode);
1432 struct nfs_delegation *delegation;
1435 flags &= FMODE_READ|FMODE_WRITE;
1437 delegation = rcu_dereference(nfsi->delegation);
1440 spin_lock(&delegation->lock);
1441 ret = nfs4_is_valid_delegation(delegation, flags);
1443 nfs4_stateid_copy(dst, &delegation->stateid);
1444 nfs_mark_delegation_referenced(delegation);
1446 *cred = get_cred(delegation->cred);
1448 spin_unlock(&delegation->lock);
1455 * nfs4_delegation_flush_on_close - Check if we must flush file on close
1456 * @inode: inode to check
1458 * This function checks the number of outstanding writes to the file
1459 * against the delegation 'space_limit' field to see if
1460 * the spec requires us to flush the file on close.
1462 bool nfs4_delegation_flush_on_close(const struct inode *inode)
1464 struct nfs_inode *nfsi = NFS_I(inode);
1465 struct nfs_delegation *delegation;
1469 delegation = rcu_dereference(nfsi->delegation);
1470 if (delegation == NULL || !(delegation->type & FMODE_WRITE))
1472 if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit)
1479 module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644);