Pull altix-fpga-reset into release branch
[linux-2.6] / fs / nfs / delegation.c
1 /*
2  * linux/fs/nfs/delegation.c
3  *
4  * Copyright (C) 2004 Trond Myklebust
5  *
6  * NFS file delegation management
7  *
8  */
9 #include <linux/config.h>
10 #include <linux/completion.h>
11 #include <linux/module.h>
12 #include <linux/sched.h>
13 #include <linux/spinlock.h>
14
15 #include <linux/nfs4.h>
16 #include <linux/nfs_fs.h>
17 #include <linux/nfs_xdr.h>
18
19 #include "nfs4_fs.h"
20 #include "delegation.h"
21
22 static struct nfs_delegation *nfs_alloc_delegation(void)
23 {
24         return (struct nfs_delegation *)kmalloc(sizeof(struct nfs_delegation), GFP_KERNEL);
25 }
26
27 static void nfs_free_delegation(struct nfs_delegation *delegation)
28 {
29         if (delegation->cred)
30                 put_rpccred(delegation->cred);
31         kfree(delegation);
32 }
33
34 static void nfs_delegation_claim_opens(struct inode *inode)
35 {
36         struct nfs_inode *nfsi = NFS_I(inode);
37         struct nfs_open_context *ctx;
38         struct nfs4_state *state;
39
40 again:
41         spin_lock(&inode->i_lock);
42         list_for_each_entry(ctx, &nfsi->open_files, list) {
43                 state = ctx->state;
44                 if (state == NULL)
45                         continue;
46                 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
47                         continue;
48                 get_nfs_open_context(ctx);
49                 spin_unlock(&inode->i_lock);
50                 if (nfs4_open_delegation_recall(ctx->dentry, state) < 0)
51                         return;
52                 put_nfs_open_context(ctx);
53                 goto again;
54         }
55         spin_unlock(&inode->i_lock);
56 }
57
58 /*
59  * Set up a delegation on an inode
60  */
61 void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
62 {
63         struct nfs_delegation *delegation = NFS_I(inode)->delegation;
64
65         if (delegation == NULL)
66                 return;
67         memcpy(delegation->stateid.data, res->delegation.data,
68                         sizeof(delegation->stateid.data));
69         delegation->type = res->delegation_type;
70         delegation->maxsize = res->maxsize;
71         put_rpccred(cred);
72         delegation->cred = get_rpccred(cred);
73         delegation->flags &= ~NFS_DELEGATION_NEED_RECLAIM;
74         NFS_I(inode)->delegation_state = delegation->type;
75         smp_wmb();
76 }
77
78 /*
79  * Set up a delegation on an inode
80  */
81 int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
82 {
83         struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
84         struct nfs_inode *nfsi = NFS_I(inode);
85         struct nfs_delegation *delegation;
86         int status = 0;
87
88         /* Ensure we first revalidate the attributes and page cache! */
89         if ((nfsi->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_ATTR)))
90                 __nfs_revalidate_inode(NFS_SERVER(inode), inode);
91
92         delegation = nfs_alloc_delegation();
93         if (delegation == NULL)
94                 return -ENOMEM;
95         memcpy(delegation->stateid.data, res->delegation.data,
96                         sizeof(delegation->stateid.data));
97         delegation->type = res->delegation_type;
98         delegation->maxsize = res->maxsize;
99         delegation->cred = get_rpccred(cred);
100         delegation->inode = inode;
101
102         spin_lock(&clp->cl_lock);
103         if (nfsi->delegation == NULL) {
104                 list_add(&delegation->super_list, &clp->cl_delegations);
105                 nfsi->delegation = delegation;
106                 nfsi->delegation_state = delegation->type;
107                 delegation = NULL;
108         } else {
109                 if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
110                                         sizeof(delegation->stateid)) != 0 ||
111                                 delegation->type != nfsi->delegation->type) {
112                         printk("%s: server %u.%u.%u.%u, handed out a duplicate delegation!\n",
113                                         __FUNCTION__, NIPQUAD(clp->cl_addr));
114                         status = -EIO;
115                 }
116         }
117         spin_unlock(&clp->cl_lock);
118         if (delegation != NULL)
119                 kfree(delegation);
120         return status;
121 }
122
123 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
124 {
125         int res = 0;
126
127         __nfs_revalidate_inode(NFS_SERVER(inode), inode);
128
129         res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid);
130         nfs_free_delegation(delegation);
131         return res;
132 }
133
134 /* Sync all data to disk upon delegation return */
135 static void nfs_msync_inode(struct inode *inode)
136 {
137         filemap_fdatawrite(inode->i_mapping);
138         nfs_wb_all(inode);
139         filemap_fdatawait(inode->i_mapping);
140 }
141
142 /*
143  * Basic procedure for returning a delegation to the server
144  */
145 int nfs_inode_return_delegation(struct inode *inode)
146 {
147         struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
148         struct nfs_inode *nfsi = NFS_I(inode);
149         struct nfs_delegation *delegation;
150         int res = 0;
151
152         nfs_msync_inode(inode);
153         down_read(&clp->cl_sem);
154         /* Guard against new delegated open calls */
155         down_write(&nfsi->rwsem);
156         spin_lock(&clp->cl_lock);
157         delegation = nfsi->delegation;
158         if (delegation != NULL) {
159                 list_del_init(&delegation->super_list);
160                 nfsi->delegation = NULL;
161                 nfsi->delegation_state = 0;
162         }
163         spin_unlock(&clp->cl_lock);
164         nfs_delegation_claim_opens(inode);
165         up_write(&nfsi->rwsem);
166         up_read(&clp->cl_sem);
167         nfs_msync_inode(inode);
168
169         if (delegation != NULL)
170                 res = nfs_do_return_delegation(inode, delegation);
171         return res;
172 }
173
174 /*
175  * Return all delegations associated to a super block
176  */
177 void nfs_return_all_delegations(struct super_block *sb)
178 {
179         struct nfs4_client *clp = NFS_SB(sb)->nfs4_state;
180         struct nfs_delegation *delegation;
181         struct inode *inode;
182
183         if (clp == NULL)
184                 return;
185 restart:
186         spin_lock(&clp->cl_lock);
187         list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
188                 if (delegation->inode->i_sb != sb)
189                         continue;
190                 inode = igrab(delegation->inode);
191                 if (inode == NULL)
192                         continue;
193                 spin_unlock(&clp->cl_lock);
194                 nfs_inode_return_delegation(inode);
195                 iput(inode);
196                 goto restart;
197         }
198         spin_unlock(&clp->cl_lock);
199 }
200
201 /*
202  * Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
203  */
204 void nfs_handle_cb_pathdown(struct nfs4_client *clp)
205 {
206         struct nfs_delegation *delegation;
207         struct inode *inode;
208
209         if (clp == NULL)
210                 return;
211 restart:
212         spin_lock(&clp->cl_lock);
213         list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
214                 inode = igrab(delegation->inode);
215                 if (inode == NULL)
216                         continue;
217                 spin_unlock(&clp->cl_lock);
218                 nfs_inode_return_delegation(inode);
219                 iput(inode);
220                 goto restart;
221         }
222         spin_unlock(&clp->cl_lock);
223 }
224
225 struct recall_threadargs {
226         struct inode *inode;
227         struct nfs4_client *clp;
228         const nfs4_stateid *stateid;
229
230         struct completion started;
231         int result;
232 };
233
234 static int recall_thread(void *data)
235 {
236         struct recall_threadargs *args = (struct recall_threadargs *)data;
237         struct inode *inode = igrab(args->inode);
238         struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
239         struct nfs_inode *nfsi = NFS_I(inode);
240         struct nfs_delegation *delegation;
241
242         daemonize("nfsv4-delegreturn");
243
244         nfs_msync_inode(inode);
245         down_read(&clp->cl_sem);
246         down_write(&nfsi->rwsem);
247         spin_lock(&clp->cl_lock);
248         delegation = nfsi->delegation;
249         if (delegation != NULL && memcmp(delegation->stateid.data,
250                                 args->stateid->data,
251                                 sizeof(delegation->stateid.data)) == 0) {
252                 list_del_init(&delegation->super_list);
253                 nfsi->delegation = NULL;
254                 nfsi->delegation_state = 0;
255                 args->result = 0;
256         } else {
257                 delegation = NULL;
258                 args->result = -ENOENT;
259         }
260         spin_unlock(&clp->cl_lock);
261         complete(&args->started);
262         nfs_delegation_claim_opens(inode);
263         up_write(&nfsi->rwsem);
264         up_read(&clp->cl_sem);
265         nfs_msync_inode(inode);
266
267         if (delegation != NULL)
268                 nfs_do_return_delegation(inode, delegation);
269         iput(inode);
270         module_put_and_exit(0);
271 }
272
273 /*
274  * Asynchronous delegation recall!
275  */
276 int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid)
277 {
278         struct recall_threadargs data = {
279                 .inode = inode,
280                 .stateid = stateid,
281         };
282         int status;
283
284         init_completion(&data.started);
285         __module_get(THIS_MODULE);
286         status = kernel_thread(recall_thread, &data, CLONE_KERNEL);
287         if (status < 0)
288                 goto out_module_put;
289         wait_for_completion(&data.started);
290         return data.result;
291 out_module_put:
292         module_put(THIS_MODULE);
293         return status;
294 }
295
296 /*
297  * Retrieve the inode associated with a delegation
298  */
299 struct inode *nfs_delegation_find_inode(struct nfs4_client *clp, const struct nfs_fh *fhandle)
300 {
301         struct nfs_delegation *delegation;
302         struct inode *res = NULL;
303         spin_lock(&clp->cl_lock);
304         list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
305                 if (nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
306                         res = igrab(delegation->inode);
307                         break;
308                 }
309         }
310         spin_unlock(&clp->cl_lock);
311         return res;
312 }
313
314 /*
315  * Mark all delegations as needing to be reclaimed
316  */
317 void nfs_delegation_mark_reclaim(struct nfs4_client *clp)
318 {
319         struct nfs_delegation *delegation;
320         spin_lock(&clp->cl_lock);
321         list_for_each_entry(delegation, &clp->cl_delegations, super_list)
322                 delegation->flags |= NFS_DELEGATION_NEED_RECLAIM;
323         spin_unlock(&clp->cl_lock);
324 }
325
326 /*
327  * Reap all unclaimed delegations after reboot recovery is done
328  */
329 void nfs_delegation_reap_unclaimed(struct nfs4_client *clp)
330 {
331         struct nfs_delegation *delegation, *n;
332         LIST_HEAD(head);
333         spin_lock(&clp->cl_lock);
334         list_for_each_entry_safe(delegation, n, &clp->cl_delegations, super_list) {
335                 if ((delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0)
336                         continue;
337                 list_move(&delegation->super_list, &head);
338                 NFS_I(delegation->inode)->delegation = NULL;
339                 NFS_I(delegation->inode)->delegation_state = 0;
340         }
341         spin_unlock(&clp->cl_lock);
342         while(!list_empty(&head)) {
343                 delegation = list_entry(head.next, struct nfs_delegation, super_list);
344                 list_del(&delegation->super_list);
345                 nfs_free_delegation(delegation);
346         }
347 }