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 nfs_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 nfs_mark_delegation_referenced(delegation);
66 static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state)
68 struct inode *inode = state->inode;
72 if (inode->i_flock == NULL)
75 /* Protect inode->i_flock using the file locks lock */
77 for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
78 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
80 if (nfs_file_open_context(fl->fl_file) != ctx)
83 status = nfs4_lock_delegation_recall(state, fl);
93 static int nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *stateid)
95 struct nfs_inode *nfsi = NFS_I(inode);
96 struct nfs_open_context *ctx;
97 struct nfs4_state *state;
101 spin_lock(&inode->i_lock);
102 list_for_each_entry(ctx, &nfsi->open_files, list) {
106 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
108 if (!nfs4_stateid_match(&state->stateid, stateid))
110 get_nfs_open_context(ctx);
111 spin_unlock(&inode->i_lock);
112 err = nfs4_open_delegation_recall(ctx, state, stateid);
114 err = nfs_delegation_claim_locks(ctx, state);
115 put_nfs_open_context(ctx);
120 spin_unlock(&inode->i_lock);
125 * nfs_inode_reclaim_delegation - process a delegation reclaim request
126 * @inode: inode to process
127 * @cred: credential to use for request
128 * @res: new delegation state from server
131 void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred,
132 struct nfs_openres *res)
134 struct nfs_delegation *delegation;
135 struct rpc_cred *oldcred = NULL;
138 delegation = rcu_dereference(NFS_I(inode)->delegation);
139 if (delegation != NULL) {
140 spin_lock(&delegation->lock);
141 if (delegation->inode != NULL) {
142 nfs4_stateid_copy(&delegation->stateid, &res->delegation);
143 delegation->type = res->delegation_type;
144 delegation->maxsize = res->maxsize;
145 oldcred = delegation->cred;
146 delegation->cred = get_rpccred(cred);
147 clear_bit(NFS_DELEGATION_NEED_RECLAIM,
149 NFS_I(inode)->delegation_state = delegation->type;
150 spin_unlock(&delegation->lock);
151 put_rpccred(oldcred);
154 /* We appear to have raced with a delegation return. */
155 spin_unlock(&delegation->lock);
157 nfs_inode_set_delegation(inode, cred, res);
164 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
168 res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid, issync);
169 nfs_free_delegation(delegation);
173 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
175 struct inode *inode = NULL;
177 spin_lock(&delegation->lock);
178 if (delegation->inode != NULL)
179 inode = igrab(delegation->inode);
180 spin_unlock(&delegation->lock);
184 static struct nfs_delegation *
185 nfs_detach_delegation_locked(struct nfs_inode *nfsi,
186 struct nfs_server *server)
188 struct nfs_delegation *delegation =
189 rcu_dereference_protected(nfsi->delegation,
190 lockdep_is_held(&server->nfs_client->cl_lock));
192 if (delegation == NULL)
195 spin_lock(&delegation->lock);
196 list_del_rcu(&delegation->super_list);
197 delegation->inode = NULL;
198 nfsi->delegation_state = 0;
199 rcu_assign_pointer(nfsi->delegation, NULL);
200 spin_unlock(&delegation->lock);
206 static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
207 struct nfs_server *server)
209 struct nfs_client *clp = server->nfs_client;
210 struct nfs_delegation *delegation;
212 spin_lock(&clp->cl_lock);
213 delegation = nfs_detach_delegation_locked(nfsi, server);
214 spin_unlock(&clp->cl_lock);
219 * nfs_inode_set_delegation - set up a delegation on an inode
220 * @inode: inode to which delegation applies
221 * @cred: cred to use for subsequent delegation processing
222 * @res: new delegation state from server
224 * Returns zero on success, or a negative errno value.
226 int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
228 struct nfs_server *server = NFS_SERVER(inode);
229 struct nfs_client *clp = server->nfs_client;
230 struct nfs_inode *nfsi = NFS_I(inode);
231 struct nfs_delegation *delegation, *old_delegation;
232 struct nfs_delegation *freeme = NULL;
235 delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
236 if (delegation == NULL)
238 nfs4_stateid_copy(&delegation->stateid, &res->delegation);
239 delegation->type = res->delegation_type;
240 delegation->maxsize = res->maxsize;
241 delegation->change_attr = inode->i_version;
242 delegation->cred = get_rpccred(cred);
243 delegation->inode = inode;
244 delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
245 spin_lock_init(&delegation->lock);
247 spin_lock(&clp->cl_lock);
248 old_delegation = rcu_dereference_protected(nfsi->delegation,
249 lockdep_is_held(&clp->cl_lock));
250 if (old_delegation != NULL) {
251 if (nfs4_stateid_match(&delegation->stateid,
252 &old_delegation->stateid) &&
253 delegation->type == old_delegation->type) {
257 * Deal with broken servers that hand out two
258 * delegations for the same file.
259 * Allow for upgrades to a WRITE delegation, but
262 dfprintk(FILE, "%s: server %s handed out "
263 "a duplicate delegation!\n",
264 __func__, clp->cl_hostname);
265 if (delegation->type == old_delegation->type ||
266 !(delegation->type & FMODE_WRITE)) {
271 freeme = nfs_detach_delegation_locked(nfsi, server);
273 list_add_rcu(&delegation->super_list, &server->delegations);
274 nfsi->delegation_state = delegation->type;
275 rcu_assign_pointer(nfsi->delegation, delegation);
278 /* Ensure we revalidate the attributes and page cache! */
279 spin_lock(&inode->i_lock);
280 nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
281 spin_unlock(&inode->i_lock);
284 spin_unlock(&clp->cl_lock);
285 if (delegation != NULL)
286 nfs_free_delegation(delegation);
288 nfs_do_return_delegation(inode, freeme, 0);
293 * Basic procedure for returning a delegation to the server
295 static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
297 struct nfs_inode *nfsi = NFS_I(inode);
301 * Guard against new delegated open/lock/unlock calls and against
304 down_write(&nfsi->rwsem);
305 err = nfs_delegation_claim_opens(inode, &delegation->stateid);
306 up_write(&nfsi->rwsem);
310 err = nfs_do_return_delegation(inode, delegation, issync);
316 * nfs_client_return_marked_delegations - return previously marked delegations
317 * @clp: nfs_client to process
319 * Returns zero on success, or a negative errno value.
321 int nfs_client_return_marked_delegations(struct nfs_client *clp)
323 struct nfs_delegation *delegation;
324 struct nfs_server *server;
330 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
331 list_for_each_entry_rcu(delegation, &server->delegations,
333 if (!test_and_clear_bit(NFS_DELEGATION_RETURN,
336 inode = nfs_delegation_grab_inode(delegation);
339 delegation = nfs_detach_delegation(NFS_I(inode),
343 if (delegation != NULL) {
344 filemap_flush(inode->i_mapping);
345 err = __nfs_inode_return_delegation(inode,
351 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
360 * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
361 * @inode: inode to process
363 * Does not protect against delegation reclaims, therefore really only safe
364 * to be called from nfs4_clear_inode().
366 void nfs_inode_return_delegation_noreclaim(struct inode *inode)
368 struct nfs_server *server = NFS_SERVER(inode);
369 struct nfs_inode *nfsi = NFS_I(inode);
370 struct nfs_delegation *delegation;
372 if (rcu_access_pointer(nfsi->delegation) != NULL) {
373 delegation = nfs_detach_delegation(nfsi, server);
374 if (delegation != NULL)
375 nfs_do_return_delegation(inode, delegation, 0);
380 * nfs_inode_return_delegation - synchronously return a delegation
381 * @inode: inode to process
383 * Returns zero on success, or a negative errno value.
385 int nfs_inode_return_delegation(struct inode *inode)
387 struct nfs_server *server = NFS_SERVER(inode);
388 struct nfs_inode *nfsi = NFS_I(inode);
389 struct nfs_delegation *delegation;
392 if (rcu_access_pointer(nfsi->delegation) != NULL) {
393 delegation = nfs_detach_delegation(nfsi, server);
394 if (delegation != NULL) {
396 err = __nfs_inode_return_delegation(inode, delegation, 1);
402 static void nfs_mark_return_delegation(struct nfs_server *server,
403 struct nfs_delegation *delegation)
405 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
406 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
410 * nfs_super_return_all_delegations - return delegations for one superblock
414 void nfs_super_return_all_delegations(struct super_block *sb)
416 struct nfs_server *server = NFS_SB(sb);
417 struct nfs_client *clp = server->nfs_client;
418 struct nfs_delegation *delegation;
424 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
425 spin_lock(&delegation->lock);
426 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
427 spin_unlock(&delegation->lock);
431 if (nfs_client_return_marked_delegations(clp) != 0)
432 nfs4_schedule_state_manager(clp);
435 static void nfs_mark_return_all_delegation_types(struct nfs_server *server,
438 struct nfs_delegation *delegation;
440 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
441 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
443 if (delegation->type & flags)
444 nfs_mark_return_delegation(server, delegation);
448 static void nfs_client_mark_return_all_delegation_types(struct nfs_client *clp,
451 struct nfs_server *server;
454 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
455 nfs_mark_return_all_delegation_types(server, flags);
459 static void nfs_delegation_run_state_manager(struct nfs_client *clp)
461 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
462 nfs4_schedule_state_manager(clp);
465 void nfs_remove_bad_delegation(struct inode *inode)
467 struct nfs_delegation *delegation;
469 delegation = nfs_detach_delegation(NFS_I(inode), NFS_SERVER(inode));
471 nfs_inode_find_state_and_recover(inode, &delegation->stateid);
472 nfs_free_delegation(delegation);
475 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);
478 * nfs_expire_all_delegation_types
479 * @clp: client to process
480 * @flags: delegation types to expire
483 void nfs_expire_all_delegation_types(struct nfs_client *clp, fmode_t flags)
485 nfs_client_mark_return_all_delegation_types(clp, flags);
486 nfs_delegation_run_state_manager(clp);
490 * nfs_expire_all_delegations
491 * @clp: client to process
494 void nfs_expire_all_delegations(struct nfs_client *clp)
496 nfs_expire_all_delegation_types(clp, FMODE_READ|FMODE_WRITE);
499 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
501 struct nfs_delegation *delegation;
503 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
504 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
506 nfs_mark_return_delegation(server, delegation);
511 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
512 * @clp: nfs_client to process
515 void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
517 struct nfs_server *server;
520 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
521 nfs_mark_return_unreferenced_delegations(server);
524 nfs_delegation_run_state_manager(clp);
528 * nfs_async_inode_return_delegation - asynchronously return a delegation
529 * @inode: inode to process
530 * @stateid: state ID information
532 * Returns zero on success, or a negative errno value.
534 int nfs_async_inode_return_delegation(struct inode *inode,
535 const nfs4_stateid *stateid)
537 struct nfs_server *server = NFS_SERVER(inode);
538 struct nfs_client *clp = server->nfs_client;
539 struct nfs_delegation *delegation;
542 delegation = rcu_dereference(NFS_I(inode)->delegation);
544 if (!clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) {
548 nfs_mark_return_delegation(server, delegation);
551 nfs_delegation_run_state_manager(clp);
555 static struct inode *
556 nfs_delegation_find_inode_server(struct nfs_server *server,
557 const struct nfs_fh *fhandle)
559 struct nfs_delegation *delegation;
560 struct inode *res = NULL;
562 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
563 spin_lock(&delegation->lock);
564 if (delegation->inode != NULL &&
565 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
566 res = igrab(delegation->inode);
568 spin_unlock(&delegation->lock);
576 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
577 * @clp: client state handle
578 * @fhandle: filehandle from a delegation recall
580 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
583 struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
584 const struct nfs_fh *fhandle)
586 struct nfs_server *server;
587 struct inode *res = NULL;
590 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
591 res = nfs_delegation_find_inode_server(server, fhandle);
599 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
601 struct nfs_delegation *delegation;
603 list_for_each_entry_rcu(delegation, &server->delegations, super_list)
604 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
608 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
609 * @clp: nfs_client to process
612 void nfs_delegation_mark_reclaim(struct nfs_client *clp)
614 struct nfs_server *server;
617 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
618 nfs_delegation_mark_reclaim_server(server);
623 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
624 * @clp: nfs_client to process
627 void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
629 struct nfs_delegation *delegation;
630 struct nfs_server *server;
635 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
636 list_for_each_entry_rcu(delegation, &server->delegations,
638 if (test_bit(NFS_DELEGATION_NEED_RECLAIM,
639 &delegation->flags) == 0)
641 inode = nfs_delegation_grab_inode(delegation);
644 delegation = nfs_detach_delegation(NFS_I(inode),
648 if (delegation != NULL)
649 nfs_free_delegation(delegation);
658 * nfs_delegations_present - check for existence of delegations
659 * @clp: client state handle
661 * Returns one if there are any nfs_delegation structures attached
662 * to this nfs_client.
664 int nfs_delegations_present(struct nfs_client *clp)
666 struct nfs_server *server;
670 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
671 if (!list_empty(&server->delegations)) {
680 * nfs4_copy_delegation_stateid - Copy inode's state ID information
681 * @dst: stateid data structure to fill in
682 * @inode: inode to check
683 * @flags: delegation type requirement
685 * Returns "true" and fills in "dst->data" * if inode had a delegation,
686 * otherwise "false" is returned.
688 bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode,
691 struct nfs_inode *nfsi = NFS_I(inode);
692 struct nfs_delegation *delegation;
695 flags &= FMODE_READ|FMODE_WRITE;
697 delegation = rcu_dereference(nfsi->delegation);
698 ret = (delegation != NULL && (delegation->type & flags) == flags);
700 nfs4_stateid_copy(dst, &delegation->stateid);
701 nfs_mark_delegation_referenced(delegation);