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1da177e4 LT |
1 | /* vnode.c: AFS vnode management |
2 | * | |
3 | * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/fs.h> | |
17 | #include <linux/pagemap.h> | |
18 | #include "volume.h" | |
19 | #include "cell.h" | |
20 | #include "cmservice.h" | |
21 | #include "fsclient.h" | |
22 | #include "vlclient.h" | |
23 | #include "vnode.h" | |
24 | #include "internal.h" | |
25 | ||
26 | static void afs_vnode_cb_timed_out(struct afs_timer *timer); | |
27 | ||
28 | struct afs_timer_ops afs_vnode_cb_timed_out_ops = { | |
29 | .timed_out = afs_vnode_cb_timed_out, | |
30 | }; | |
31 | ||
32 | #ifdef AFS_CACHING_SUPPORT | |
33 | static cachefs_match_val_t afs_vnode_cache_match(void *target, | |
34 | const void *entry); | |
35 | static void afs_vnode_cache_update(void *source, void *entry); | |
36 | ||
37 | struct cachefs_index_def afs_vnode_cache_index_def = { | |
38 | .name = "vnode", | |
39 | .data_size = sizeof(struct afs_cache_vnode), | |
40 | .keys[0] = { CACHEFS_INDEX_KEYS_BIN, 4 }, | |
41 | .match = afs_vnode_cache_match, | |
42 | .update = afs_vnode_cache_update, | |
43 | }; | |
44 | #endif | |
45 | ||
46 | /*****************************************************************************/ | |
47 | /* | |
48 | * handle a callback timing out | |
49 | * TODO: retain a ref to vnode struct for an outstanding callback timeout | |
50 | */ | |
51 | static void afs_vnode_cb_timed_out(struct afs_timer *timer) | |
52 | { | |
53 | struct afs_server *oldserver; | |
54 | struct afs_vnode *vnode; | |
55 | ||
56 | vnode = list_entry(timer, struct afs_vnode, cb_timeout); | |
57 | ||
58 | _enter("%p", vnode); | |
59 | ||
60 | /* set the changed flag in the vnode and release the server */ | |
61 | spin_lock(&vnode->lock); | |
62 | ||
63 | oldserver = xchg(&vnode->cb_server, NULL); | |
64 | if (oldserver) { | |
65 | vnode->flags |= AFS_VNODE_CHANGED; | |
66 | ||
67 | spin_lock(&afs_cb_hash_lock); | |
68 | list_del_init(&vnode->cb_hash_link); | |
69 | spin_unlock(&afs_cb_hash_lock); | |
70 | ||
71 | spin_lock(&oldserver->cb_lock); | |
72 | list_del_init(&vnode->cb_link); | |
73 | spin_unlock(&oldserver->cb_lock); | |
74 | } | |
75 | ||
76 | spin_unlock(&vnode->lock); | |
77 | ||
78 | afs_put_server(oldserver); | |
79 | ||
80 | _leave(""); | |
81 | } /* end afs_vnode_cb_timed_out() */ | |
82 | ||
83 | /*****************************************************************************/ | |
84 | /* | |
85 | * finish off updating the recorded status of a file | |
86 | * - starts callback expiry timer | |
87 | * - adds to server's callback list | |
88 | */ | |
89 | static void afs_vnode_finalise_status_update(struct afs_vnode *vnode, | |
90 | struct afs_server *server, | |
91 | int ret) | |
92 | { | |
93 | struct afs_server *oldserver = NULL; | |
94 | ||
95 | _enter("%p,%p,%d", vnode, server, ret); | |
96 | ||
97 | spin_lock(&vnode->lock); | |
98 | ||
99 | vnode->flags &= ~AFS_VNODE_CHANGED; | |
100 | ||
101 | if (ret == 0) { | |
102 | /* adjust the callback timeout appropriately */ | |
103 | afs_kafstimod_add_timer(&vnode->cb_timeout, | |
104 | vnode->cb_expiry * HZ); | |
105 | ||
106 | spin_lock(&afs_cb_hash_lock); | |
107 | list_del(&vnode->cb_hash_link); | |
108 | list_add_tail(&vnode->cb_hash_link, | |
109 | &afs_cb_hash(server, &vnode->fid)); | |
110 | spin_unlock(&afs_cb_hash_lock); | |
111 | ||
112 | /* swap ref to old callback server with that for new callback | |
113 | * server */ | |
114 | oldserver = xchg(&vnode->cb_server, server); | |
115 | if (oldserver != server) { | |
116 | if (oldserver) { | |
117 | spin_lock(&oldserver->cb_lock); | |
118 | list_del_init(&vnode->cb_link); | |
119 | spin_unlock(&oldserver->cb_lock); | |
120 | } | |
121 | ||
122 | afs_get_server(server); | |
123 | spin_lock(&server->cb_lock); | |
124 | list_add_tail(&vnode->cb_link, &server->cb_promises); | |
125 | spin_unlock(&server->cb_lock); | |
126 | } | |
127 | else { | |
128 | /* same server */ | |
129 | oldserver = NULL; | |
130 | } | |
131 | } | |
132 | else if (ret == -ENOENT) { | |
133 | /* the file was deleted - clear the callback timeout */ | |
134 | oldserver = xchg(&vnode->cb_server, NULL); | |
135 | afs_kafstimod_del_timer(&vnode->cb_timeout); | |
136 | ||
137 | _debug("got NOENT from server - marking file deleted"); | |
138 | vnode->flags |= AFS_VNODE_DELETED; | |
139 | } | |
140 | ||
141 | vnode->update_cnt--; | |
142 | ||
143 | spin_unlock(&vnode->lock); | |
144 | ||
145 | wake_up_all(&vnode->update_waitq); | |
146 | ||
147 | afs_put_server(oldserver); | |
148 | ||
149 | _leave(""); | |
150 | ||
151 | } /* end afs_vnode_finalise_status_update() */ | |
152 | ||
153 | /*****************************************************************************/ | |
154 | /* | |
155 | * fetch file status from the volume | |
156 | * - don't issue a fetch if: | |
157 | * - the changed bit is not set and there's a valid callback | |
158 | * - there are any outstanding ops that will fetch the status | |
159 | * - TODO implement local caching | |
160 | */ | |
161 | int afs_vnode_fetch_status(struct afs_vnode *vnode) | |
162 | { | |
163 | struct afs_server *server; | |
164 | int ret; | |
165 | ||
166 | DECLARE_WAITQUEUE(myself, current); | |
167 | ||
168 | _enter("%s,{%u,%u,%u}", | |
169 | vnode->volume->vlocation->vldb.name, | |
170 | vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique); | |
171 | ||
172 | if (!(vnode->flags & AFS_VNODE_CHANGED) && vnode->cb_server) { | |
173 | _leave(" [unchanged]"); | |
174 | return 0; | |
175 | } | |
176 | ||
177 | if (vnode->flags & AFS_VNODE_DELETED) { | |
178 | _leave(" [deleted]"); | |
179 | return -ENOENT; | |
180 | } | |
181 | ||
182 | spin_lock(&vnode->lock); | |
183 | ||
184 | if (!(vnode->flags & AFS_VNODE_CHANGED)) { | |
185 | spin_unlock(&vnode->lock); | |
186 | _leave(" [unchanged]"); | |
187 | return 0; | |
188 | } | |
189 | ||
190 | if (vnode->update_cnt > 0) { | |
191 | /* someone else started a fetch */ | |
192 | set_current_state(TASK_UNINTERRUPTIBLE); | |
193 | add_wait_queue(&vnode->update_waitq, &myself); | |
194 | ||
195 | /* wait for the status to be updated */ | |
196 | for (;;) { | |
197 | if (!(vnode->flags & AFS_VNODE_CHANGED)) | |
198 | break; | |
199 | if (vnode->flags & AFS_VNODE_DELETED) | |
200 | break; | |
201 | ||
202 | /* it got updated and invalidated all before we saw | |
203 | * it */ | |
204 | if (vnode->update_cnt == 0) { | |
205 | remove_wait_queue(&vnode->update_waitq, | |
206 | &myself); | |
207 | set_current_state(TASK_RUNNING); | |
208 | goto get_anyway; | |
209 | } | |
210 | ||
211 | spin_unlock(&vnode->lock); | |
212 | ||
213 | schedule(); | |
214 | set_current_state(TASK_UNINTERRUPTIBLE); | |
215 | ||
216 | spin_lock(&vnode->lock); | |
217 | } | |
218 | ||
219 | remove_wait_queue(&vnode->update_waitq, &myself); | |
220 | spin_unlock(&vnode->lock); | |
221 | set_current_state(TASK_RUNNING); | |
222 | ||
223 | return vnode->flags & AFS_VNODE_DELETED ? -ENOENT : 0; | |
224 | } | |
225 | ||
226 | get_anyway: | |
227 | /* okay... we're going to have to initiate the op */ | |
228 | vnode->update_cnt++; | |
229 | ||
230 | spin_unlock(&vnode->lock); | |
231 | ||
232 | /* merge AFS status fetches and clear outstanding callback on this | |
233 | * vnode */ | |
234 | do { | |
235 | /* pick a server to query */ | |
236 | ret = afs_volume_pick_fileserver(vnode->volume, &server); | |
237 | if (ret<0) | |
238 | return ret; | |
239 | ||
240 | _debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr)); | |
241 | ||
242 | ret = afs_rxfs_fetch_file_status(server, vnode, NULL); | |
243 | ||
244 | } while (!afs_volume_release_fileserver(vnode->volume, server, ret)); | |
245 | ||
246 | /* adjust the flags */ | |
247 | afs_vnode_finalise_status_update(vnode, server, ret); | |
248 | ||
249 | _leave(" = %d", ret); | |
250 | return ret; | |
251 | } /* end afs_vnode_fetch_status() */ | |
252 | ||
253 | /*****************************************************************************/ | |
254 | /* | |
255 | * fetch file data from the volume | |
256 | * - TODO implement caching and server failover | |
257 | */ | |
258 | int afs_vnode_fetch_data(struct afs_vnode *vnode, | |
259 | struct afs_rxfs_fetch_descriptor *desc) | |
260 | { | |
261 | struct afs_server *server; | |
262 | int ret; | |
263 | ||
264 | _enter("%s,{%u,%u,%u}", | |
265 | vnode->volume->vlocation->vldb.name, | |
266 | vnode->fid.vid, | |
267 | vnode->fid.vnode, | |
268 | vnode->fid.unique); | |
269 | ||
270 | /* this op will fetch the status */ | |
271 | spin_lock(&vnode->lock); | |
272 | vnode->update_cnt++; | |
273 | spin_unlock(&vnode->lock); | |
274 | ||
275 | /* merge in AFS status fetches and clear outstanding callback on this | |
276 | * vnode */ | |
277 | do { | |
278 | /* pick a server to query */ | |
279 | ret = afs_volume_pick_fileserver(vnode->volume, &server); | |
280 | if (ret < 0) | |
281 | return ret; | |
282 | ||
283 | _debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr)); | |
284 | ||
285 | ret = afs_rxfs_fetch_file_data(server, vnode, desc, NULL); | |
286 | ||
287 | } while (!afs_volume_release_fileserver(vnode->volume, server, ret)); | |
288 | ||
289 | /* adjust the flags */ | |
290 | afs_vnode_finalise_status_update(vnode, server, ret); | |
291 | ||
292 | _leave(" = %d", ret); | |
293 | return ret; | |
294 | ||
295 | } /* end afs_vnode_fetch_data() */ | |
296 | ||
297 | /*****************************************************************************/ | |
298 | /* | |
299 | * break any outstanding callback on a vnode | |
300 | * - only relevent to server that issued it | |
301 | */ | |
302 | int afs_vnode_give_up_callback(struct afs_vnode *vnode) | |
303 | { | |
304 | struct afs_server *server; | |
305 | int ret; | |
306 | ||
307 | _enter("%s,{%u,%u,%u}", | |
308 | vnode->volume->vlocation->vldb.name, | |
309 | vnode->fid.vid, | |
310 | vnode->fid.vnode, | |
311 | vnode->fid.unique); | |
312 | ||
313 | spin_lock(&afs_cb_hash_lock); | |
314 | list_del_init(&vnode->cb_hash_link); | |
315 | spin_unlock(&afs_cb_hash_lock); | |
316 | ||
317 | /* set the changed flag in the vnode and release the server */ | |
318 | spin_lock(&vnode->lock); | |
319 | ||
320 | afs_kafstimod_del_timer(&vnode->cb_timeout); | |
321 | ||
322 | server = xchg(&vnode->cb_server, NULL); | |
323 | if (server) { | |
324 | vnode->flags |= AFS_VNODE_CHANGED; | |
325 | ||
326 | spin_lock(&server->cb_lock); | |
327 | list_del_init(&vnode->cb_link); | |
328 | spin_unlock(&server->cb_lock); | |
329 | } | |
330 | ||
331 | spin_unlock(&vnode->lock); | |
332 | ||
333 | ret = 0; | |
334 | if (server) { | |
335 | ret = afs_rxfs_give_up_callback(server, vnode); | |
336 | afs_put_server(server); | |
337 | } | |
338 | ||
339 | _leave(" = %d", ret); | |
340 | return ret; | |
341 | } /* end afs_vnode_give_up_callback() */ | |
342 | ||
343 | /*****************************************************************************/ | |
344 | /* | |
345 | * match a vnode record stored in the cache | |
346 | */ | |
347 | #ifdef AFS_CACHING_SUPPORT | |
348 | static cachefs_match_val_t afs_vnode_cache_match(void *target, | |
349 | const void *entry) | |
350 | { | |
351 | const struct afs_cache_vnode *cvnode = entry; | |
352 | struct afs_vnode *vnode = target; | |
353 | ||
354 | _enter("{%x,%x,%Lx},{%x,%x,%Lx}", | |
355 | vnode->fid.vnode, | |
356 | vnode->fid.unique, | |
357 | vnode->status.version, | |
358 | cvnode->vnode_id, | |
359 | cvnode->vnode_unique, | |
360 | cvnode->data_version); | |
361 | ||
362 | if (vnode->fid.vnode != cvnode->vnode_id) { | |
363 | _leave(" = FAILED"); | |
364 | return CACHEFS_MATCH_FAILED; | |
365 | } | |
366 | ||
367 | if (vnode->fid.unique != cvnode->vnode_unique || | |
368 | vnode->status.version != cvnode->data_version) { | |
369 | _leave(" = DELETE"); | |
370 | return CACHEFS_MATCH_SUCCESS_DELETE; | |
371 | } | |
372 | ||
373 | _leave(" = SUCCESS"); | |
374 | return CACHEFS_MATCH_SUCCESS; | |
375 | } /* end afs_vnode_cache_match() */ | |
376 | #endif | |
377 | ||
378 | /*****************************************************************************/ | |
379 | /* | |
380 | * update a vnode record stored in the cache | |
381 | */ | |
382 | #ifdef AFS_CACHING_SUPPORT | |
383 | static void afs_vnode_cache_update(void *source, void *entry) | |
384 | { | |
385 | struct afs_cache_vnode *cvnode = entry; | |
386 | struct afs_vnode *vnode = source; | |
387 | ||
388 | _enter(""); | |
389 | ||
390 | cvnode->vnode_id = vnode->fid.vnode; | |
391 | cvnode->vnode_unique = vnode->fid.unique; | |
392 | cvnode->data_version = vnode->status.version; | |
393 | ||
394 | } /* end afs_vnode_cache_update() */ | |
395 | #endif |