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);