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/spinlock.h>
15 #include <linux/nfs4.h>
16 #include <linux/nfs_fs.h>
17 #include <linux/nfs_xdr.h>
20 #include "delegation.h"
23 static void nfs_do_free_delegation(struct nfs_delegation *delegation)
28 static void nfs_free_delegation_callback(struct rcu_head *head)
30 struct nfs_delegation *delegation = container_of(head, struct nfs_delegation, rcu);
32 nfs_do_free_delegation(delegation);
35 static void nfs_free_delegation(struct nfs_delegation *delegation)
37 struct rpc_cred *cred;
39 cred = rcu_dereference(delegation->cred);
40 rcu_assign_pointer(delegation->cred, NULL);
41 call_rcu(&delegation->rcu, nfs_free_delegation_callback);
46 void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
48 set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
51 int nfs_have_delegation(struct inode *inode, fmode_t flags)
53 struct nfs_delegation *delegation;
56 flags &= FMODE_READ|FMODE_WRITE;
58 delegation = rcu_dereference(NFS_I(inode)->delegation);
59 if (delegation != NULL && (delegation->type & flags) == flags) {
60 nfs_mark_delegation_referenced(delegation);
67 static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state)
69 struct inode *inode = state->inode;
73 for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
74 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
76 if (nfs_file_open_context(fl->fl_file) != ctx)
78 status = nfs4_lock_delegation_recall(state, fl);
83 printk(KERN_ERR "%s: unhandled error %d.\n",
85 case -NFS4ERR_EXPIRED:
86 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
87 case -NFS4ERR_STALE_CLIENTID:
88 nfs4_schedule_state_recovery(NFS_SERVER(inode)->nfs_client);
97 static void nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *stateid)
99 struct nfs_inode *nfsi = NFS_I(inode);
100 struct nfs_open_context *ctx;
101 struct nfs4_state *state;
105 spin_lock(&inode->i_lock);
106 list_for_each_entry(ctx, &nfsi->open_files, list) {
110 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
112 if (memcmp(state->stateid.data, stateid->data, sizeof(state->stateid.data)) != 0)
114 get_nfs_open_context(ctx);
115 spin_unlock(&inode->i_lock);
116 err = nfs4_open_delegation_recall(ctx, state, stateid);
118 err = nfs_delegation_claim_locks(ctx, state);
119 put_nfs_open_context(ctx);
124 spin_unlock(&inode->i_lock);
128 * Set up a delegation on an inode
130 void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
132 struct nfs_delegation *delegation = NFS_I(inode)->delegation;
133 struct rpc_cred *oldcred;
135 if (delegation == NULL)
137 memcpy(delegation->stateid.data, res->delegation.data,
138 sizeof(delegation->stateid.data));
139 delegation->type = res->delegation_type;
140 delegation->maxsize = res->maxsize;
141 oldcred = delegation->cred;
142 delegation->cred = get_rpccred(cred);
143 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
144 NFS_I(inode)->delegation_state = delegation->type;
146 put_rpccred(oldcred);
149 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
153 res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid, issync);
154 nfs_free_delegation(delegation);
158 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
160 struct inode *inode = NULL;
162 spin_lock(&delegation->lock);
163 if (delegation->inode != NULL)
164 inode = igrab(delegation->inode);
165 spin_unlock(&delegation->lock);
169 static struct nfs_delegation *nfs_detach_delegation_locked(struct nfs_inode *nfsi, const nfs4_stateid *stateid)
171 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
173 if (delegation == NULL)
175 spin_lock(&delegation->lock);
176 if (stateid != NULL && memcmp(delegation->stateid.data, stateid->data,
177 sizeof(delegation->stateid.data)) != 0)
179 list_del_rcu(&delegation->super_list);
180 delegation->inode = NULL;
181 nfsi->delegation_state = 0;
182 rcu_assign_pointer(nfsi->delegation, NULL);
183 spin_unlock(&delegation->lock);
186 spin_unlock(&delegation->lock);
192 * Set up a delegation on an inode
194 int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
196 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
197 struct nfs_inode *nfsi = NFS_I(inode);
198 struct nfs_delegation *delegation;
199 struct nfs_delegation *freeme = NULL;
202 delegation = kmalloc(sizeof(*delegation), GFP_KERNEL);
203 if (delegation == NULL)
205 memcpy(delegation->stateid.data, res->delegation.data,
206 sizeof(delegation->stateid.data));
207 delegation->type = res->delegation_type;
208 delegation->maxsize = res->maxsize;
209 delegation->change_attr = nfsi->change_attr;
210 delegation->cred = get_rpccred(cred);
211 delegation->inode = inode;
212 delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
213 spin_lock_init(&delegation->lock);
215 spin_lock(&clp->cl_lock);
216 if (rcu_dereference(nfsi->delegation) != NULL) {
217 if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
218 sizeof(delegation->stateid)) == 0 &&
219 delegation->type == nfsi->delegation->type) {
223 * Deal with broken servers that hand out two
224 * delegations for the same file.
226 dfprintk(FILE, "%s: server %s handed out "
227 "a duplicate delegation!\n",
228 __func__, clp->cl_hostname);
229 if (delegation->type <= nfsi->delegation->type) {
234 freeme = nfs_detach_delegation_locked(nfsi, NULL);
236 list_add_rcu(&delegation->super_list, &clp->cl_delegations);
237 nfsi->delegation_state = delegation->type;
238 rcu_assign_pointer(nfsi->delegation, delegation);
241 /* Ensure we revalidate the attributes and page cache! */
242 spin_lock(&inode->i_lock);
243 nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
244 spin_unlock(&inode->i_lock);
247 spin_unlock(&clp->cl_lock);
248 if (delegation != NULL)
249 nfs_free_delegation(delegation);
251 nfs_do_return_delegation(inode, freeme, 0);
255 /* Sync all data to disk upon delegation return */
256 static void nfs_msync_inode(struct inode *inode)
258 filemap_fdatawrite(inode->i_mapping);
260 filemap_fdatawait(inode->i_mapping);
264 * Basic procedure for returning a delegation to the server
266 static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
268 struct nfs_inode *nfsi = NFS_I(inode);
270 nfs_msync_inode(inode);
271 /* Guard against new delegated open calls */
272 down_write(&nfsi->rwsem);
273 nfs_delegation_claim_opens(inode, &delegation->stateid);
274 up_write(&nfsi->rwsem);
275 nfs_msync_inode(inode);
277 return nfs_do_return_delegation(inode, delegation, 1);
281 * Return all delegations that have been marked for return
283 void nfs_client_return_marked_delegations(struct nfs_client *clp)
285 struct nfs_delegation *delegation;
290 list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
291 if (!test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
293 inode = nfs_delegation_grab_inode(delegation);
296 spin_lock(&clp->cl_lock);
297 delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
298 spin_unlock(&clp->cl_lock);
300 if (delegation != NULL)
301 __nfs_inode_return_delegation(inode, delegation);
309 * This function returns the delegation without reclaiming opens
310 * or protecting against delegation reclaims.
311 * It is therefore really only safe to be called from
314 void nfs_inode_return_delegation_noreclaim(struct inode *inode)
316 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
317 struct nfs_inode *nfsi = NFS_I(inode);
318 struct nfs_delegation *delegation;
320 if (rcu_dereference(nfsi->delegation) != NULL) {
321 spin_lock(&clp->cl_lock);
322 delegation = nfs_detach_delegation_locked(nfsi, NULL);
323 spin_unlock(&clp->cl_lock);
324 if (delegation != NULL)
325 nfs_do_return_delegation(inode, delegation, 0);
329 int nfs_inode_return_delegation(struct inode *inode)
331 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
332 struct nfs_inode *nfsi = NFS_I(inode);
333 struct nfs_delegation *delegation;
336 if (rcu_dereference(nfsi->delegation) != NULL) {
337 spin_lock(&clp->cl_lock);
338 delegation = nfs_detach_delegation_locked(nfsi, NULL);
339 spin_unlock(&clp->cl_lock);
340 if (delegation != NULL)
341 err = __nfs_inode_return_delegation(inode, delegation);
346 static void nfs_mark_return_delegation(struct nfs_client *clp, struct nfs_delegation *delegation)
348 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
349 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
353 * Return all delegations associated to a super block
355 void nfs_super_return_all_delegations(struct super_block *sb)
357 struct nfs_client *clp = NFS_SB(sb)->nfs_client;
358 struct nfs_delegation *delegation;
363 list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
364 spin_lock(&delegation->lock);
365 if (delegation->inode != NULL && delegation->inode->i_sb == sb)
366 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
367 spin_unlock(&delegation->lock);
370 nfs_client_return_marked_delegations(clp);
373 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
375 struct nfs_delegation *delegation;
378 list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
379 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
380 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
385 static void nfs_delegation_run_state_manager(struct nfs_client *clp)
387 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
388 nfs4_schedule_state_manager(clp);
391 void nfs_expire_all_delegations(struct nfs_client *clp)
393 nfs_client_mark_return_all_delegations(clp);
394 nfs_delegation_run_state_manager(clp);
398 * Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
400 void nfs_handle_cb_pathdown(struct nfs_client *clp)
404 nfs_client_mark_return_all_delegations(clp);
407 static void nfs_client_mark_return_unreferenced_delegations(struct nfs_client *clp)
409 struct nfs_delegation *delegation;
412 list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
413 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
415 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
416 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
421 void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
423 nfs_client_mark_return_unreferenced_delegations(clp);
424 nfs_delegation_run_state_manager(clp);
428 * Asynchronous delegation recall!
430 int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid)
432 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
433 struct nfs_delegation *delegation;
436 delegation = rcu_dereference(NFS_I(inode)->delegation);
437 if (delegation == NULL || memcmp(delegation->stateid.data, stateid->data,
438 sizeof(delegation->stateid.data)) != 0) {
442 nfs_mark_return_delegation(clp, delegation);
444 nfs_delegation_run_state_manager(clp);
449 * Retrieve the inode associated with a delegation
451 struct inode *nfs_delegation_find_inode(struct nfs_client *clp, const struct nfs_fh *fhandle)
453 struct nfs_delegation *delegation;
454 struct inode *res = NULL;
456 list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
457 spin_lock(&delegation->lock);
458 if (delegation->inode != NULL &&
459 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
460 res = igrab(delegation->inode);
462 spin_unlock(&delegation->lock);
471 * Mark all delegations as needing to be reclaimed
473 void nfs_delegation_mark_reclaim(struct nfs_client *clp)
475 struct nfs_delegation *delegation;
477 list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list)
478 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
483 * Reap all unclaimed delegations after reboot recovery is done
485 void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
487 struct nfs_delegation *delegation;
491 list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
492 if (test_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags) == 0)
494 inode = nfs_delegation_grab_inode(delegation);
497 spin_lock(&clp->cl_lock);
498 delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
499 spin_unlock(&clp->cl_lock);
501 if (delegation != NULL)
502 nfs_free_delegation(delegation);
509 int nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
511 struct nfs_inode *nfsi = NFS_I(inode);
512 struct nfs_delegation *delegation;
516 delegation = rcu_dereference(nfsi->delegation);
517 if (delegation != NULL) {
518 memcpy(dst->data, delegation->stateid.data, sizeof(dst->data));