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 if (inode->i_flock == NULL)
78 /* Protect inode->i_flock using the file locks lock */
80 for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
81 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
83 if (nfs_file_open_context(fl->fl_file) != ctx)
86 status = nfs4_lock_delegation_recall(fl, state, stateid);
96 static int nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *stateid)
98 struct nfs_inode *nfsi = NFS_I(inode);
99 struct nfs_open_context *ctx;
100 struct nfs4_state_owner *sp;
101 struct nfs4_state *state;
106 spin_lock(&inode->i_lock);
107 list_for_each_entry(ctx, &nfsi->open_files, list) {
111 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
113 if (!nfs4_stateid_match(&state->stateid, stateid))
115 get_nfs_open_context(ctx);
116 spin_unlock(&inode->i_lock);
118 /* Block nfs4_proc_unlck */
119 mutex_lock(&sp->so_delegreturn_mutex);
120 seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
121 err = nfs4_open_delegation_recall(ctx, state, stateid);
123 err = nfs_delegation_claim_locks(ctx, state, stateid);
124 if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
126 mutex_unlock(&sp->so_delegreturn_mutex);
127 put_nfs_open_context(ctx);
132 spin_unlock(&inode->i_lock);
137 * nfs_inode_reclaim_delegation - process a delegation reclaim request
138 * @inode: inode to process
139 * @cred: credential to use for request
140 * @res: new delegation state from server
143 void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred,
144 struct nfs_openres *res)
146 struct nfs_delegation *delegation;
147 struct rpc_cred *oldcred = NULL;
150 delegation = rcu_dereference(NFS_I(inode)->delegation);
151 if (delegation != NULL) {
152 spin_lock(&delegation->lock);
153 if (delegation->inode != NULL) {
154 nfs4_stateid_copy(&delegation->stateid, &res->delegation);
155 delegation->type = res->delegation_type;
156 delegation->maxsize = res->maxsize;
157 oldcred = delegation->cred;
158 delegation->cred = get_rpccred(cred);
159 clear_bit(NFS_DELEGATION_NEED_RECLAIM,
161 NFS_I(inode)->delegation_state = delegation->type;
162 spin_unlock(&delegation->lock);
163 put_rpccred(oldcred);
166 /* We appear to have raced with a delegation return. */
167 spin_unlock(&delegation->lock);
169 nfs_inode_set_delegation(inode, cred, res);
176 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
180 res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid, issync);
181 nfs_free_delegation(delegation);
185 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
187 struct inode *inode = NULL;
189 spin_lock(&delegation->lock);
190 if (delegation->inode != NULL)
191 inode = igrab(delegation->inode);
192 spin_unlock(&delegation->lock);
196 static struct nfs_delegation *
197 nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
199 struct nfs_delegation *ret = NULL;
200 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
202 if (delegation == NULL)
204 spin_lock(&delegation->lock);
205 if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
207 spin_unlock(&delegation->lock);
212 static struct nfs_delegation *
213 nfs_start_delegation_return(struct nfs_inode *nfsi)
215 struct nfs_delegation *delegation;
218 delegation = nfs_start_delegation_return_locked(nfsi);
224 nfs_abort_delegation_return(struct nfs_delegation *delegation,
225 struct nfs_client *clp)
228 spin_lock(&delegation->lock);
229 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
230 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
231 spin_unlock(&delegation->lock);
232 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
235 static struct nfs_delegation *
236 nfs_detach_delegation_locked(struct nfs_inode *nfsi,
237 struct nfs_delegation *delegation,
238 struct nfs_client *clp)
240 struct nfs_delegation *deleg_cur =
241 rcu_dereference_protected(nfsi->delegation,
242 lockdep_is_held(&clp->cl_lock));
244 if (deleg_cur == NULL || delegation != deleg_cur)
247 spin_lock(&delegation->lock);
248 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
249 list_del_rcu(&delegation->super_list);
250 delegation->inode = NULL;
251 nfsi->delegation_state = 0;
252 rcu_assign_pointer(nfsi->delegation, NULL);
253 spin_unlock(&delegation->lock);
257 static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
258 struct nfs_delegation *delegation,
259 struct nfs_server *server)
261 struct nfs_client *clp = server->nfs_client;
263 spin_lock(&clp->cl_lock);
264 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp);
265 spin_unlock(&clp->cl_lock);
269 static struct nfs_delegation *
270 nfs_inode_detach_delegation(struct inode *inode)
272 struct nfs_inode *nfsi = NFS_I(inode);
273 struct nfs_server *server = NFS_SERVER(inode);
274 struct nfs_delegation *delegation;
276 delegation = nfs_start_delegation_return(nfsi);
277 if (delegation == NULL)
279 return nfs_detach_delegation(nfsi, delegation, server);
283 * nfs_inode_set_delegation - set up a delegation on an inode
284 * @inode: inode to which delegation applies
285 * @cred: cred to use for subsequent delegation processing
286 * @res: new delegation state from server
288 * Returns zero on success, or a negative errno value.
290 int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
292 struct nfs_server *server = NFS_SERVER(inode);
293 struct nfs_client *clp = server->nfs_client;
294 struct nfs_inode *nfsi = NFS_I(inode);
295 struct nfs_delegation *delegation, *old_delegation;
296 struct nfs_delegation *freeme = NULL;
299 delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
300 if (delegation == NULL)
302 nfs4_stateid_copy(&delegation->stateid, &res->delegation);
303 delegation->type = res->delegation_type;
304 delegation->maxsize = res->maxsize;
305 delegation->change_attr = inode->i_version;
306 delegation->cred = get_rpccred(cred);
307 delegation->inode = inode;
308 delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
309 spin_lock_init(&delegation->lock);
311 spin_lock(&clp->cl_lock);
312 old_delegation = rcu_dereference_protected(nfsi->delegation,
313 lockdep_is_held(&clp->cl_lock));
314 if (old_delegation != NULL) {
315 if (nfs4_stateid_match(&delegation->stateid,
316 &old_delegation->stateid) &&
317 delegation->type == old_delegation->type) {
321 * Deal with broken servers that hand out two
322 * delegations for the same file.
323 * Allow for upgrades to a WRITE delegation, but
326 dfprintk(FILE, "%s: server %s handed out "
327 "a duplicate delegation!\n",
328 __func__, clp->cl_hostname);
329 if (delegation->type == old_delegation->type ||
330 !(delegation->type & FMODE_WRITE)) {
335 freeme = nfs_detach_delegation_locked(nfsi,
336 old_delegation, clp);
340 list_add_rcu(&delegation->super_list, &server->delegations);
341 nfsi->delegation_state = delegation->type;
342 rcu_assign_pointer(nfsi->delegation, delegation);
345 /* Ensure we revalidate the attributes and page cache! */
346 spin_lock(&inode->i_lock);
347 nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
348 spin_unlock(&inode->i_lock);
351 spin_unlock(&clp->cl_lock);
352 if (delegation != NULL)
353 nfs_free_delegation(delegation);
355 nfs_do_return_delegation(inode, freeme, 0);
360 * Basic procedure for returning a delegation to the server
362 static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
364 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
365 struct nfs_inode *nfsi = NFS_I(inode);
368 if (delegation == NULL)
371 err = nfs_delegation_claim_opens(inode, &delegation->stateid);
372 if (!issync || err != -EAGAIN)
375 * Guard against state recovery
377 err = nfs4_wait_clnt_recover(clp);
381 nfs_abort_delegation_return(delegation, clp);
384 if (!nfs_detach_delegation(nfsi, delegation, NFS_SERVER(inode)))
387 err = nfs_do_return_delegation(inode, delegation, issync);
392 static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
396 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
398 if (test_and_clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) && !ret) {
401 spin_lock(&delegation->lock);
402 inode = delegation->inode;
403 if (inode && list_empty(&NFS_I(inode)->open_files))
405 spin_unlock(&delegation->lock);
411 * nfs_client_return_marked_delegations - return previously marked delegations
412 * @clp: nfs_client to process
414 * Note that this function is designed to be called by the state
415 * manager thread. For this reason, it cannot flush the dirty data,
416 * since that could deadlock in case of a state recovery error.
418 * Returns zero on success, or a negative errno value.
420 int nfs_client_return_marked_delegations(struct nfs_client *clp)
422 struct nfs_delegation *delegation;
423 struct nfs_server *server;
429 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
430 list_for_each_entry_rcu(delegation, &server->delegations,
432 if (!nfs_delegation_need_return(delegation))
434 inode = nfs_delegation_grab_inode(delegation);
437 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
440 err = nfs_end_delegation_return(inode, delegation, 0);
444 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
453 * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
454 * @inode: inode to process
456 * Does not protect against delegation reclaims, therefore really only safe
457 * to be called from nfs4_clear_inode().
459 void nfs_inode_return_delegation_noreclaim(struct inode *inode)
461 struct nfs_delegation *delegation;
463 delegation = nfs_inode_detach_delegation(inode);
464 if (delegation != NULL)
465 nfs_do_return_delegation(inode, delegation, 0);
469 * nfs_inode_return_delegation - synchronously return a delegation
470 * @inode: inode to process
472 * This routine will always flush any dirty data to disk on the
473 * assumption that if we need to return the delegation, then
474 * we should stop caching.
476 * Returns zero on success, or a negative errno value.
478 int nfs4_inode_return_delegation(struct inode *inode)
480 struct nfs_inode *nfsi = NFS_I(inode);
481 struct nfs_delegation *delegation;
485 delegation = nfs_start_delegation_return(nfsi);
486 if (delegation != NULL)
487 err = nfs_end_delegation_return(inode, delegation, 1);
491 static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
492 struct nfs_delegation *delegation)
494 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
495 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
498 static void nfs_mark_return_delegation(struct nfs_server *server,
499 struct nfs_delegation *delegation)
501 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
502 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
506 * nfs_super_return_all_delegations - return delegations for one superblock
510 void nfs_server_return_all_delegations(struct nfs_server *server)
512 struct nfs_client *clp = server->nfs_client;
513 struct nfs_delegation *delegation;
519 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
520 spin_lock(&delegation->lock);
521 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
522 spin_unlock(&delegation->lock);
526 if (nfs_client_return_marked_delegations(clp) != 0)
527 nfs4_schedule_state_manager(clp);
530 static void nfs_mark_return_all_delegation_types(struct nfs_server *server,
533 struct nfs_delegation *delegation;
535 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
536 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
538 if (delegation->type & flags)
539 nfs_mark_return_delegation(server, delegation);
543 static void nfs_client_mark_return_all_delegation_types(struct nfs_client *clp,
546 struct nfs_server *server;
549 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
550 nfs_mark_return_all_delegation_types(server, flags);
554 static void nfs_delegation_run_state_manager(struct nfs_client *clp)
556 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
557 nfs4_schedule_state_manager(clp);
560 void nfs_remove_bad_delegation(struct inode *inode)
562 struct nfs_delegation *delegation;
564 delegation = nfs_inode_detach_delegation(inode);
566 nfs_inode_find_state_and_recover(inode, &delegation->stateid);
567 nfs_free_delegation(delegation);
570 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);
573 * nfs_expire_all_delegation_types
574 * @clp: client to process
575 * @flags: delegation types to expire
578 void nfs_expire_all_delegation_types(struct nfs_client *clp, fmode_t flags)
580 nfs_client_mark_return_all_delegation_types(clp, flags);
581 nfs_delegation_run_state_manager(clp);
585 * nfs_expire_all_delegations
586 * @clp: client to process
589 void nfs_expire_all_delegations(struct nfs_client *clp)
591 nfs_expire_all_delegation_types(clp, FMODE_READ|FMODE_WRITE);
594 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
596 struct nfs_delegation *delegation;
598 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
599 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
601 nfs_mark_return_if_closed_delegation(server, delegation);
606 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
607 * @clp: nfs_client to process
610 void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
612 struct nfs_server *server;
615 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
616 nfs_mark_return_unreferenced_delegations(server);
619 nfs_delegation_run_state_manager(clp);
623 * nfs_async_inode_return_delegation - asynchronously return a delegation
624 * @inode: inode to process
625 * @stateid: state ID information
627 * Returns zero on success, or a negative errno value.
629 int nfs_async_inode_return_delegation(struct inode *inode,
630 const nfs4_stateid *stateid)
632 struct nfs_server *server = NFS_SERVER(inode);
633 struct nfs_client *clp = server->nfs_client;
634 struct nfs_delegation *delegation;
636 filemap_flush(inode->i_mapping);
639 delegation = rcu_dereference(NFS_I(inode)->delegation);
641 if (!clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) {
645 nfs_mark_return_delegation(server, delegation);
648 nfs_delegation_run_state_manager(clp);
652 static struct inode *
653 nfs_delegation_find_inode_server(struct nfs_server *server,
654 const struct nfs_fh *fhandle)
656 struct nfs_delegation *delegation;
657 struct inode *res = NULL;
659 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
660 spin_lock(&delegation->lock);
661 if (delegation->inode != NULL &&
662 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
663 res = igrab(delegation->inode);
665 spin_unlock(&delegation->lock);
673 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
674 * @clp: client state handle
675 * @fhandle: filehandle from a delegation recall
677 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
680 struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
681 const struct nfs_fh *fhandle)
683 struct nfs_server *server;
684 struct inode *res = NULL;
687 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
688 res = nfs_delegation_find_inode_server(server, fhandle);
696 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
698 struct nfs_delegation *delegation;
700 list_for_each_entry_rcu(delegation, &server->delegations, super_list)
701 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
705 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
706 * @clp: nfs_client to process
709 void nfs_delegation_mark_reclaim(struct nfs_client *clp)
711 struct nfs_server *server;
714 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
715 nfs_delegation_mark_reclaim_server(server);
720 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
721 * @clp: nfs_client to process
724 void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
726 struct nfs_delegation *delegation;
727 struct nfs_server *server;
732 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
733 list_for_each_entry_rcu(delegation, &server->delegations,
735 if (test_bit(NFS_DELEGATION_NEED_RECLAIM,
736 &delegation->flags) == 0)
738 inode = nfs_delegation_grab_inode(delegation);
741 delegation = nfs_detach_delegation(NFS_I(inode),
745 if (delegation != NULL)
746 nfs_free_delegation(delegation);
755 * nfs_delegations_present - check for existence of delegations
756 * @clp: client state handle
758 * Returns one if there are any nfs_delegation structures attached
759 * to this nfs_client.
761 int nfs_delegations_present(struct nfs_client *clp)
763 struct nfs_server *server;
767 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
768 if (!list_empty(&server->delegations)) {
777 * nfs4_copy_delegation_stateid - Copy inode's state ID information
778 * @dst: stateid data structure to fill in
779 * @inode: inode to check
780 * @flags: delegation type requirement
782 * Returns "true" and fills in "dst->data" * if inode had a delegation,
783 * otherwise "false" is returned.
785 bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode,
788 struct nfs_inode *nfsi = NFS_I(inode);
789 struct nfs_delegation *delegation;
792 flags &= FMODE_READ|FMODE_WRITE;
794 delegation = rcu_dereference(nfsi->delegation);
795 ret = (delegation != NULL && (delegation->type & flags) == flags);
797 nfs4_stateid_copy(dst, &delegation->stateid);
798 nfs_mark_delegation_referenced(delegation);