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Commit | Line | Data |
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08e0e7c8 | 1 | /* AFS volume location management |
1da177e4 | 2 | * |
08e0e7c8 | 3 | * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved. |
1da177e4 LT |
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> | |
1da177e4 LT |
15 | #include "internal.h" |
16 | ||
08e0e7c8 DH |
17 | unsigned afs_vlocation_timeout = 10; /* volume location timeout in seconds */ |
18 | unsigned afs_vlocation_update_timeout = 10 * 60; | |
1da177e4 | 19 | |
08e0e7c8 DH |
20 | static void afs_vlocation_reaper(struct work_struct *); |
21 | static void afs_vlocation_updater(struct work_struct *); | |
1da177e4 | 22 | |
08e0e7c8 DH |
23 | static LIST_HEAD(afs_vlocation_updates); |
24 | static LIST_HEAD(afs_vlocation_graveyard); | |
25 | static DEFINE_SPINLOCK(afs_vlocation_updates_lock); | |
26 | static DEFINE_SPINLOCK(afs_vlocation_graveyard_lock); | |
27 | static DECLARE_DELAYED_WORK(afs_vlocation_reap, afs_vlocation_reaper); | |
28 | static DECLARE_DELAYED_WORK(afs_vlocation_update, afs_vlocation_updater); | |
29 | static struct workqueue_struct *afs_vlocation_update_worker; | |
1da177e4 | 30 | |
1da177e4 LT |
31 | /* |
32 | * iterate through the VL servers in a cell until one of them admits knowing | |
33 | * about the volume in question | |
1da177e4 | 34 | */ |
08e0e7c8 | 35 | static int afs_vlocation_access_vl_by_name(struct afs_vlocation *vl, |
00d3b7a4 | 36 | struct key *key, |
1da177e4 LT |
37 | struct afs_cache_vlocation *vldb) |
38 | { | |
08e0e7c8 DH |
39 | struct afs_cell *cell = vl->cell; |
40 | struct in_addr addr; | |
1da177e4 LT |
41 | int count, ret; |
42 | ||
08e0e7c8 | 43 | _enter("%s,%s", cell->name, vl->vldb.name); |
1da177e4 | 44 | |
08e0e7c8 | 45 | down_write(&vl->cell->vl_sem); |
1da177e4 LT |
46 | ret = -ENOMEDIUM; |
47 | for (count = cell->vl_naddrs; count > 0; count--) { | |
08e0e7c8 DH |
48 | addr = cell->vl_addrs[cell->vl_curr_svix]; |
49 | ||
50 | _debug("CellServ[%hu]: %08x", cell->vl_curr_svix, addr.s_addr); | |
1da177e4 LT |
51 | |
52 | /* attempt to access the VL server */ | |
00d3b7a4 | 53 | ret = afs_vl_get_entry_by_name(&addr, key, vl->vldb.name, vldb, |
08e0e7c8 | 54 | &afs_sync_call); |
1da177e4 LT |
55 | switch (ret) { |
56 | case 0: | |
1da177e4 LT |
57 | goto out; |
58 | case -ENOMEM: | |
59 | case -ENONET: | |
60 | case -ENETUNREACH: | |
61 | case -EHOSTUNREACH: | |
62 | case -ECONNREFUSED: | |
1da177e4 LT |
63 | if (ret == -ENOMEM || ret == -ENONET) |
64 | goto out; | |
65 | goto rotate; | |
66 | case -ENOMEDIUM: | |
1da177e4 LT |
67 | goto out; |
68 | default: | |
08e0e7c8 | 69 | ret = -EIO; |
1da177e4 LT |
70 | goto rotate; |
71 | } | |
72 | ||
73 | /* rotate the server records upon lookup failure */ | |
74 | rotate: | |
75 | cell->vl_curr_svix++; | |
76 | cell->vl_curr_svix %= cell->vl_naddrs; | |
77 | } | |
78 | ||
ec26815a | 79 | out: |
08e0e7c8 | 80 | up_write(&vl->cell->vl_sem); |
1da177e4 LT |
81 | _leave(" = %d", ret); |
82 | return ret; | |
ec26815a | 83 | } |
1da177e4 | 84 | |
1da177e4 LT |
85 | /* |
86 | * iterate through the VL servers in a cell until one of them admits knowing | |
87 | * about the volume in question | |
1da177e4 | 88 | */ |
08e0e7c8 | 89 | static int afs_vlocation_access_vl_by_id(struct afs_vlocation *vl, |
00d3b7a4 | 90 | struct key *key, |
1da177e4 LT |
91 | afs_volid_t volid, |
92 | afs_voltype_t voltype, | |
93 | struct afs_cache_vlocation *vldb) | |
94 | { | |
08e0e7c8 DH |
95 | struct afs_cell *cell = vl->cell; |
96 | struct in_addr addr; | |
1da177e4 LT |
97 | int count, ret; |
98 | ||
99 | _enter("%s,%x,%d,", cell->name, volid, voltype); | |
100 | ||
08e0e7c8 | 101 | down_write(&vl->cell->vl_sem); |
1da177e4 LT |
102 | ret = -ENOMEDIUM; |
103 | for (count = cell->vl_naddrs; count > 0; count--) { | |
08e0e7c8 DH |
104 | addr = cell->vl_addrs[cell->vl_curr_svix]; |
105 | ||
106 | _debug("CellServ[%hu]: %08x", cell->vl_curr_svix, addr.s_addr); | |
1da177e4 LT |
107 | |
108 | /* attempt to access the VL server */ | |
00d3b7a4 | 109 | ret = afs_vl_get_entry_by_id(&addr, key, volid, voltype, vldb, |
08e0e7c8 | 110 | &afs_sync_call); |
1da177e4 LT |
111 | switch (ret) { |
112 | case 0: | |
1da177e4 LT |
113 | goto out; |
114 | case -ENOMEM: | |
115 | case -ENONET: | |
116 | case -ENETUNREACH: | |
117 | case -EHOSTUNREACH: | |
118 | case -ECONNREFUSED: | |
1da177e4 LT |
119 | if (ret == -ENOMEM || ret == -ENONET) |
120 | goto out; | |
121 | goto rotate; | |
08e0e7c8 DH |
122 | case -EBUSY: |
123 | vl->upd_busy_cnt++; | |
124 | if (vl->upd_busy_cnt <= 3) { | |
125 | if (vl->upd_busy_cnt > 1) { | |
126 | /* second+ BUSY - sleep a little bit */ | |
127 | set_current_state(TASK_UNINTERRUPTIBLE); | |
128 | schedule_timeout(1); | |
129 | __set_current_state(TASK_RUNNING); | |
130 | } | |
131 | continue; | |
132 | } | |
133 | break; | |
1da177e4 | 134 | case -ENOMEDIUM: |
08e0e7c8 DH |
135 | vl->upd_rej_cnt++; |
136 | goto rotate; | |
1da177e4 | 137 | default: |
08e0e7c8 | 138 | ret = -EIO; |
1da177e4 LT |
139 | goto rotate; |
140 | } | |
141 | ||
142 | /* rotate the server records upon lookup failure */ | |
143 | rotate: | |
144 | cell->vl_curr_svix++; | |
145 | cell->vl_curr_svix %= cell->vl_naddrs; | |
08e0e7c8 | 146 | vl->upd_busy_cnt = 0; |
1da177e4 LT |
147 | } |
148 | ||
ec26815a | 149 | out: |
08e0e7c8 DH |
150 | if (ret < 0 && vl->upd_rej_cnt > 0) { |
151 | printk(KERN_NOTICE "kAFS:" | |
152 | " Active volume no longer valid '%s'\n", | |
153 | vl->vldb.name); | |
154 | vl->valid = 0; | |
155 | ret = -ENOMEDIUM; | |
156 | } | |
157 | ||
158 | up_write(&vl->cell->vl_sem); | |
1da177e4 LT |
159 | _leave(" = %d", ret); |
160 | return ret; | |
ec26815a | 161 | } |
1da177e4 | 162 | |
1da177e4 | 163 | /* |
08e0e7c8 | 164 | * allocate a volume location record |
1da177e4 | 165 | */ |
08e0e7c8 DH |
166 | static struct afs_vlocation *afs_vlocation_alloc(struct afs_cell *cell, |
167 | const char *name, | |
168 | size_t namesz) | |
1da177e4 | 169 | { |
08e0e7c8 DH |
170 | struct afs_vlocation *vl; |
171 | ||
172 | vl = kzalloc(sizeof(struct afs_vlocation), GFP_KERNEL); | |
173 | if (vl) { | |
174 | vl->cell = cell; | |
175 | vl->state = AFS_VL_NEW; | |
176 | atomic_set(&vl->usage, 1); | |
177 | INIT_LIST_HEAD(&vl->link); | |
178 | INIT_LIST_HEAD(&vl->grave); | |
179 | INIT_LIST_HEAD(&vl->update); | |
180 | init_waitqueue_head(&vl->waitq); | |
39bf0949 | 181 | spin_lock_init(&vl->lock); |
08e0e7c8 | 182 | memcpy(vl->vldb.name, name, namesz); |
1da177e4 LT |
183 | } |
184 | ||
08e0e7c8 DH |
185 | _leave(" = %p", vl); |
186 | return vl; | |
187 | } | |
1da177e4 | 188 | |
08e0e7c8 DH |
189 | /* |
190 | * update record if we found it in the cache | |
191 | */ | |
192 | static int afs_vlocation_update_record(struct afs_vlocation *vl, | |
00d3b7a4 | 193 | struct key *key, |
08e0e7c8 DH |
194 | struct afs_cache_vlocation *vldb) |
195 | { | |
196 | afs_voltype_t voltype; | |
197 | afs_volid_t vid; | |
198 | int ret; | |
1da177e4 | 199 | |
1da177e4 | 200 | /* try to look up a cached volume in the cell VL databases by ID */ |
1da177e4 | 201 | _debug("Locally Cached: %s %02x { %08x(%x) %08x(%x) %08x(%x) }", |
08e0e7c8 DH |
202 | vl->vldb.name, |
203 | vl->vldb.vidmask, | |
204 | ntohl(vl->vldb.servers[0].s_addr), | |
205 | vl->vldb.srvtmask[0], | |
206 | ntohl(vl->vldb.servers[1].s_addr), | |
207 | vl->vldb.srvtmask[1], | |
208 | ntohl(vl->vldb.servers[2].s_addr), | |
209 | vl->vldb.srvtmask[2]); | |
1da177e4 LT |
210 | |
211 | _debug("Vids: %08x %08x %08x", | |
08e0e7c8 DH |
212 | vl->vldb.vid[0], |
213 | vl->vldb.vid[1], | |
214 | vl->vldb.vid[2]); | |
1da177e4 | 215 | |
08e0e7c8 DH |
216 | if (vl->vldb.vidmask & AFS_VOL_VTM_RW) { |
217 | vid = vl->vldb.vid[0]; | |
1da177e4 | 218 | voltype = AFSVL_RWVOL; |
08e0e7c8 DH |
219 | } else if (vl->vldb.vidmask & AFS_VOL_VTM_RO) { |
220 | vid = vl->vldb.vid[1]; | |
1da177e4 | 221 | voltype = AFSVL_ROVOL; |
08e0e7c8 DH |
222 | } else if (vl->vldb.vidmask & AFS_VOL_VTM_BAK) { |
223 | vid = vl->vldb.vid[2]; | |
1da177e4 | 224 | voltype = AFSVL_BACKVOL; |
ec26815a | 225 | } else { |
1da177e4 LT |
226 | BUG(); |
227 | vid = 0; | |
228 | voltype = 0; | |
229 | } | |
230 | ||
08e0e7c8 DH |
231 | /* contact the server to make sure the volume is still available |
232 | * - TODO: need to handle disconnected operation here | |
233 | */ | |
00d3b7a4 | 234 | ret = afs_vlocation_access_vl_by_id(vl, key, vid, voltype, vldb); |
1da177e4 LT |
235 | switch (ret) { |
236 | /* net error */ | |
237 | default: | |
08e0e7c8 DH |
238 | printk(KERN_WARNING "kAFS:" |
239 | " failed to update volume '%s' (%x) up in '%s': %d\n", | |
240 | vl->vldb.name, vid, vl->cell->name, ret); | |
241 | _leave(" = %d", ret); | |
242 | return ret; | |
1da177e4 LT |
243 | |
244 | /* pulled from local cache into memory */ | |
245 | case 0: | |
08e0e7c8 DH |
246 | _leave(" = 0"); |
247 | return 0; | |
1da177e4 LT |
248 | |
249 | /* uh oh... looks like the volume got deleted */ | |
250 | case -ENOMEDIUM: | |
08e0e7c8 DH |
251 | printk(KERN_ERR "kAFS:" |
252 | " volume '%s' (%x) does not exist '%s'\n", | |
253 | vl->vldb.name, vid, vl->cell->name); | |
1da177e4 LT |
254 | |
255 | /* TODO: make existing record unavailable */ | |
08e0e7c8 DH |
256 | _leave(" = %d", ret); |
257 | return ret; | |
1da177e4 | 258 | } |
08e0e7c8 | 259 | } |
1da177e4 | 260 | |
08e0e7c8 DH |
261 | /* |
262 | * apply the update to a VL record | |
263 | */ | |
264 | static void afs_vlocation_apply_update(struct afs_vlocation *vl, | |
265 | struct afs_cache_vlocation *vldb) | |
266 | { | |
267 | _debug("Done VL Lookup: %s %02x { %08x(%x) %08x(%x) %08x(%x) }", | |
268 | vldb->name, vldb->vidmask, | |
269 | ntohl(vldb->servers[0].s_addr), vldb->srvtmask[0], | |
270 | ntohl(vldb->servers[1].s_addr), vldb->srvtmask[1], | |
271 | ntohl(vldb->servers[2].s_addr), vldb->srvtmask[2]); | |
1da177e4 | 272 | |
08e0e7c8 DH |
273 | _debug("Vids: %08x %08x %08x", |
274 | vldb->vid[0], vldb->vid[1], vldb->vid[2]); | |
1da177e4 | 275 | |
08e0e7c8 DH |
276 | if (strcmp(vldb->name, vl->vldb.name) != 0) |
277 | printk(KERN_NOTICE "kAFS:" | |
278 | " name of volume '%s' changed to '%s' on server\n", | |
279 | vl->vldb.name, vldb->name); | |
1da177e4 | 280 | |
08e0e7c8 | 281 | vl->vldb = *vldb; |
1da177e4 LT |
282 | |
283 | #ifdef AFS_CACHING_SUPPORT | |
284 | /* update volume entry in local cache */ | |
08e0e7c8 | 285 | cachefs_update_cookie(vl->cache); |
1da177e4 | 286 | #endif |
ec26815a | 287 | } |
1da177e4 | 288 | |
1da177e4 | 289 | /* |
08e0e7c8 DH |
290 | * fill in a volume location record, consulting the cache and the VL server |
291 | * both | |
1da177e4 | 292 | */ |
00d3b7a4 DH |
293 | static int afs_vlocation_fill_in_record(struct afs_vlocation *vl, |
294 | struct key *key) | |
1da177e4 | 295 | { |
08e0e7c8 DH |
296 | struct afs_cache_vlocation vldb; |
297 | int ret; | |
1da177e4 | 298 | |
08e0e7c8 | 299 | _enter(""); |
1da177e4 | 300 | |
08e0e7c8 | 301 | ASSERTCMP(vl->valid, ==, 0); |
1da177e4 | 302 | |
08e0e7c8 | 303 | memset(&vldb, 0, sizeof(vldb)); |
1da177e4 | 304 | |
08e0e7c8 DH |
305 | /* see if we have an in-cache copy (will set vl->valid if there is) */ |
306 | #ifdef AFS_CACHING_SUPPORT | |
307 | cachefs_acquire_cookie(cell->cache, | |
308 | &afs_volume_cache_index_def, | |
309 | vlocation, | |
310 | &vl->cache); | |
311 | #endif | |
1da177e4 | 312 | |
08e0e7c8 DH |
313 | if (vl->valid) { |
314 | /* try to update a known volume in the cell VL databases by | |
315 | * ID as the name may have changed */ | |
316 | _debug("found in cache"); | |
00d3b7a4 | 317 | ret = afs_vlocation_update_record(vl, key, &vldb); |
08e0e7c8 DH |
318 | } else { |
319 | /* try to look up an unknown volume in the cell VL databases by | |
320 | * name */ | |
00d3b7a4 | 321 | ret = afs_vlocation_access_vl_by_name(vl, key, &vldb); |
08e0e7c8 DH |
322 | if (ret < 0) { |
323 | printk("kAFS: failed to locate '%s' in cell '%s'\n", | |
324 | vl->vldb.name, vl->cell->name); | |
325 | return ret; | |
326 | } | |
1da177e4 LT |
327 | } |
328 | ||
08e0e7c8 DH |
329 | afs_vlocation_apply_update(vl, &vldb); |
330 | _leave(" = 0"); | |
331 | return 0; | |
ec26815a | 332 | } |
1da177e4 | 333 | |
1da177e4 | 334 | /* |
08e0e7c8 | 335 | * queue a vlocation record for updates |
1da177e4 | 336 | */ |
08e0e7c8 | 337 | void afs_vlocation_queue_for_updates(struct afs_vlocation *vl) |
1da177e4 | 338 | { |
08e0e7c8 | 339 | struct afs_vlocation *xvl; |
1da177e4 | 340 | |
08e0e7c8 DH |
341 | /* wait at least 10 minutes before updating... */ |
342 | vl->update_at = get_seconds() + afs_vlocation_update_timeout; | |
343 | ||
344 | spin_lock(&afs_vlocation_updates_lock); | |
345 | ||
346 | if (!list_empty(&afs_vlocation_updates)) { | |
347 | /* ... but wait at least 1 second more than the newest record | |
348 | * already queued so that we don't spam the VL server suddenly | |
349 | * with lots of requests | |
350 | */ | |
351 | xvl = list_entry(afs_vlocation_updates.prev, | |
352 | struct afs_vlocation, update); | |
353 | if (vl->update_at <= xvl->update_at) | |
354 | vl->update_at = xvl->update_at + 1; | |
355 | } else { | |
356 | queue_delayed_work(afs_vlocation_update_worker, | |
357 | &afs_vlocation_update, | |
358 | afs_vlocation_update_timeout * HZ); | |
1da177e4 | 359 | } |
08e0e7c8 DH |
360 | |
361 | list_add_tail(&vl->update, &afs_vlocation_updates); | |
362 | spin_unlock(&afs_vlocation_updates_lock); | |
ec26815a | 363 | } |
1da177e4 | 364 | |
1da177e4 | 365 | /* |
08e0e7c8 DH |
366 | * lookup volume location |
367 | * - iterate through the VL servers in a cell until one of them admits knowing | |
368 | * about the volume in question | |
369 | * - lookup in the local cache if not able to find on the VL server | |
370 | * - insert/update in the local cache if did get a VL response | |
1da177e4 | 371 | */ |
08e0e7c8 | 372 | struct afs_vlocation *afs_vlocation_lookup(struct afs_cell *cell, |
00d3b7a4 | 373 | struct key *key, |
08e0e7c8 DH |
374 | const char *name, |
375 | size_t namesz) | |
1da177e4 | 376 | { |
08e0e7c8 DH |
377 | struct afs_vlocation *vl; |
378 | int ret; | |
1da177e4 | 379 | |
00d3b7a4 DH |
380 | _enter("{%s},{%x},%*.*s,%zu", |
381 | cell->name, key_serial(key), | |
382 | (int) namesz, (int) namesz, name, namesz); | |
1da177e4 | 383 | |
08e0e7c8 DH |
384 | if (namesz > sizeof(vl->vldb.name)) { |
385 | _leave(" = -ENAMETOOLONG"); | |
386 | return ERR_PTR(-ENAMETOOLONG); | |
387 | } | |
1da177e4 | 388 | |
08e0e7c8 DH |
389 | /* see if we have an in-memory copy first */ |
390 | down_write(&cell->vl_sem); | |
391 | spin_lock(&cell->vl_lock); | |
392 | list_for_each_entry(vl, &cell->vl_list, link) { | |
393 | if (vl->vldb.name[namesz] != '\0') | |
394 | continue; | |
395 | if (memcmp(vl->vldb.name, name, namesz) == 0) | |
396 | goto found_in_memory; | |
1da177e4 | 397 | } |
08e0e7c8 | 398 | spin_unlock(&cell->vl_lock); |
1da177e4 | 399 | |
08e0e7c8 DH |
400 | /* not in the cell's in-memory lists - create a new record */ |
401 | vl = afs_vlocation_alloc(cell, name, namesz); | |
402 | if (!vl) { | |
403 | up_write(&cell->vl_sem); | |
404 | return ERR_PTR(-ENOMEM); | |
405 | } | |
1da177e4 | 406 | |
08e0e7c8 | 407 | afs_get_cell(cell); |
1da177e4 | 408 | |
08e0e7c8 DH |
409 | list_add_tail(&vl->link, &cell->vl_list); |
410 | vl->state = AFS_VL_CREATING; | |
411 | up_write(&cell->vl_sem); | |
1da177e4 | 412 | |
08e0e7c8 | 413 | fill_in_record: |
00d3b7a4 | 414 | ret = afs_vlocation_fill_in_record(vl, key); |
08e0e7c8 DH |
415 | if (ret < 0) |
416 | goto error_abandon; | |
39bf0949 | 417 | spin_lock(&vl->lock); |
08e0e7c8 | 418 | vl->state = AFS_VL_VALID; |
39bf0949 | 419 | spin_unlock(&vl->lock); |
47051a21 | 420 | wake_up(&vl->waitq); |
1da177e4 | 421 | |
08e0e7c8 DH |
422 | /* schedule for regular updates */ |
423 | afs_vlocation_queue_for_updates(vl); | |
424 | goto success; | |
1da177e4 | 425 | |
08e0e7c8 DH |
426 | found_in_memory: |
427 | /* found in memory */ | |
428 | _debug("found in memory"); | |
429 | atomic_inc(&vl->usage); | |
430 | spin_unlock(&cell->vl_lock); | |
431 | if (!list_empty(&vl->grave)) { | |
432 | spin_lock(&afs_vlocation_graveyard_lock); | |
433 | list_del_init(&vl->grave); | |
434 | spin_unlock(&afs_vlocation_graveyard_lock); | |
1da177e4 | 435 | } |
08e0e7c8 | 436 | up_write(&cell->vl_sem); |
1da177e4 | 437 | |
08e0e7c8 | 438 | /* see if it was an abandoned record that we might try filling in */ |
39bf0949 | 439 | spin_lock(&vl->lock); |
08e0e7c8 DH |
440 | while (vl->state != AFS_VL_VALID) { |
441 | afs_vlocation_state_t state = vl->state; | |
1da177e4 | 442 | |
08e0e7c8 | 443 | _debug("invalid [state %d]", state); |
1da177e4 | 444 | |
47051a21 | 445 | if (state == AFS_VL_NEW || state == AFS_VL_NO_VOLUME) { |
39bf0949 DM |
446 | vl->state = AFS_VL_CREATING; |
447 | spin_unlock(&vl->lock); | |
448 | goto fill_in_record; | |
08e0e7c8 DH |
449 | } |
450 | ||
451 | /* must now wait for creation or update by someone else to | |
452 | * complete */ | |
453 | _debug("wait"); | |
454 | ||
39bf0949 | 455 | spin_unlock(&vl->lock); |
47051a21 DH |
456 | ret = wait_event_interruptible(vl->waitq, |
457 | vl->state == AFS_VL_NEW || | |
458 | vl->state == AFS_VL_VALID || | |
459 | vl->state == AFS_VL_NO_VOLUME); | |
08e0e7c8 DH |
460 | if (ret < 0) |
461 | goto error; | |
39bf0949 | 462 | spin_lock(&vl->lock); |
1da177e4 | 463 | } |
39bf0949 | 464 | spin_unlock(&vl->lock); |
1da177e4 | 465 | |
08e0e7c8 DH |
466 | success: |
467 | _leave(" = %p",vl); | |
468 | return vl; | |
469 | ||
470 | error_abandon: | |
39bf0949 | 471 | spin_lock(&vl->lock); |
08e0e7c8 | 472 | vl->state = AFS_VL_NEW; |
39bf0949 | 473 | spin_unlock(&vl->lock); |
47051a21 | 474 | wake_up(&vl->waitq); |
08e0e7c8 DH |
475 | error: |
476 | ASSERT(vl != NULL); | |
477 | afs_put_vlocation(vl); | |
1da177e4 | 478 | _leave(" = %d", ret); |
08e0e7c8 | 479 | return ERR_PTR(ret); |
ec26815a | 480 | } |
1da177e4 | 481 | |
1da177e4 | 482 | /* |
08e0e7c8 | 483 | * finish using a volume location record |
1da177e4 | 484 | */ |
08e0e7c8 | 485 | void afs_put_vlocation(struct afs_vlocation *vl) |
1da177e4 | 486 | { |
08e0e7c8 DH |
487 | if (!vl) |
488 | return; | |
1da177e4 | 489 | |
08e0e7c8 | 490 | _enter("%s", vl->vldb.name); |
1da177e4 | 491 | |
08e0e7c8 | 492 | ASSERTCMP(atomic_read(&vl->usage), >, 0); |
1da177e4 | 493 | |
08e0e7c8 DH |
494 | if (likely(!atomic_dec_and_test(&vl->usage))) { |
495 | _leave(""); | |
496 | return; | |
497 | } | |
1da177e4 | 498 | |
08e0e7c8 DH |
499 | spin_lock(&afs_vlocation_graveyard_lock); |
500 | if (atomic_read(&vl->usage) == 0) { | |
501 | _debug("buried"); | |
502 | list_move_tail(&vl->grave, &afs_vlocation_graveyard); | |
503 | vl->time_of_death = get_seconds(); | |
504 | schedule_delayed_work(&afs_vlocation_reap, | |
505 | afs_vlocation_timeout * HZ); | |
506 | ||
507 | /* suspend updates on this record */ | |
508 | if (!list_empty(&vl->update)) { | |
509 | spin_lock(&afs_vlocation_updates_lock); | |
510 | list_del_init(&vl->update); | |
511 | spin_unlock(&afs_vlocation_updates_lock); | |
512 | } | |
513 | } | |
514 | spin_unlock(&afs_vlocation_graveyard_lock); | |
515 | _leave(" [killed?]"); | |
ec26815a | 516 | } |
1da177e4 | 517 | |
1da177e4 | 518 | /* |
08e0e7c8 | 519 | * destroy a dead volume location record |
1da177e4 | 520 | */ |
08e0e7c8 | 521 | static void afs_vlocation_destroy(struct afs_vlocation *vl) |
1da177e4 | 522 | { |
08e0e7c8 | 523 | _enter("%p", vl); |
1da177e4 | 524 | |
08e0e7c8 DH |
525 | #ifdef AFS_CACHING_SUPPORT |
526 | cachefs_relinquish_cookie(vl->cache, 0); | |
527 | #endif | |
1da177e4 | 528 | |
08e0e7c8 DH |
529 | afs_put_cell(vl->cell); |
530 | kfree(vl); | |
531 | } | |
532 | ||
533 | /* | |
534 | * reap dead volume location records | |
535 | */ | |
536 | static void afs_vlocation_reaper(struct work_struct *work) | |
537 | { | |
538 | LIST_HEAD(corpses); | |
539 | struct afs_vlocation *vl; | |
540 | unsigned long delay, expiry; | |
541 | time_t now; | |
1da177e4 | 542 | |
08e0e7c8 | 543 | _enter(""); |
1da177e4 | 544 | |
08e0e7c8 DH |
545 | now = get_seconds(); |
546 | spin_lock(&afs_vlocation_graveyard_lock); | |
547 | ||
548 | while (!list_empty(&afs_vlocation_graveyard)) { | |
549 | vl = list_entry(afs_vlocation_graveyard.next, | |
550 | struct afs_vlocation, grave); | |
551 | ||
552 | _debug("check %p", vl); | |
553 | ||
554 | /* the queue is ordered most dead first */ | |
555 | expiry = vl->time_of_death + afs_vlocation_timeout; | |
556 | if (expiry > now) { | |
557 | delay = (expiry - now) * HZ; | |
558 | _debug("delay %lu", delay); | |
559 | if (!schedule_delayed_work(&afs_vlocation_reap, | |
560 | delay)) { | |
561 | cancel_delayed_work(&afs_vlocation_reap); | |
562 | schedule_delayed_work(&afs_vlocation_reap, | |
563 | delay); | |
564 | } | |
565 | break; | |
566 | } | |
1da177e4 | 567 | |
08e0e7c8 DH |
568 | spin_lock(&vl->cell->vl_lock); |
569 | if (atomic_read(&vl->usage) > 0) { | |
570 | _debug("no reap"); | |
571 | list_del_init(&vl->grave); | |
ec26815a | 572 | } else { |
08e0e7c8 DH |
573 | _debug("reap"); |
574 | list_move_tail(&vl->grave, &corpses); | |
575 | list_del_init(&vl->link); | |
1da177e4 | 576 | } |
08e0e7c8 | 577 | spin_unlock(&vl->cell->vl_lock); |
1da177e4 LT |
578 | } |
579 | ||
08e0e7c8 | 580 | spin_unlock(&afs_vlocation_graveyard_lock); |
1da177e4 | 581 | |
08e0e7c8 DH |
582 | /* now reap the corpses we've extracted */ |
583 | while (!list_empty(&corpses)) { | |
584 | vl = list_entry(corpses.next, struct afs_vlocation, grave); | |
585 | list_del(&vl->grave); | |
586 | afs_vlocation_destroy(vl); | |
1da177e4 LT |
587 | } |
588 | ||
589 | _leave(""); | |
08e0e7c8 | 590 | } |
1da177e4 | 591 | |
08e0e7c8 DH |
592 | /* |
593 | * initialise the VL update process | |
594 | */ | |
595 | int __init afs_vlocation_update_init(void) | |
596 | { | |
597 | afs_vlocation_update_worker = | |
598 | create_singlethread_workqueue("kafs_vlupdated"); | |
599 | return afs_vlocation_update_worker ? 0 : -ENOMEM; | |
600 | } | |
601 | ||
602 | /* | |
603 | * discard all the volume location records for rmmod | |
604 | */ | |
fbb3fcba | 605 | void afs_vlocation_purge(void) |
08e0e7c8 DH |
606 | { |
607 | afs_vlocation_timeout = 0; | |
608 | ||
609 | spin_lock(&afs_vlocation_updates_lock); | |
610 | list_del_init(&afs_vlocation_updates); | |
611 | spin_unlock(&afs_vlocation_updates_lock); | |
612 | cancel_delayed_work(&afs_vlocation_update); | |
613 | queue_delayed_work(afs_vlocation_update_worker, | |
614 | &afs_vlocation_update, 0); | |
615 | destroy_workqueue(afs_vlocation_update_worker); | |
616 | ||
617 | cancel_delayed_work(&afs_vlocation_reap); | |
618 | schedule_delayed_work(&afs_vlocation_reap, 0); | |
ec26815a | 619 | } |
1da177e4 | 620 | |
1da177e4 | 621 | /* |
08e0e7c8 | 622 | * update a volume location |
1da177e4 | 623 | */ |
08e0e7c8 | 624 | static void afs_vlocation_updater(struct work_struct *work) |
1da177e4 LT |
625 | { |
626 | struct afs_cache_vlocation vldb; | |
08e0e7c8 DH |
627 | struct afs_vlocation *vl, *xvl; |
628 | time_t now; | |
629 | long timeout; | |
1da177e4 LT |
630 | int ret; |
631 | ||
08e0e7c8 | 632 | _enter(""); |
1da177e4 | 633 | |
08e0e7c8 | 634 | now = get_seconds(); |
1da177e4 | 635 | |
08e0e7c8 DH |
636 | /* find a record to update */ |
637 | spin_lock(&afs_vlocation_updates_lock); | |
638 | for (;;) { | |
639 | if (list_empty(&afs_vlocation_updates)) { | |
640 | spin_unlock(&afs_vlocation_updates_lock); | |
641 | _leave(" [nothing]"); | |
642 | return; | |
643 | } | |
1da177e4 | 644 | |
08e0e7c8 DH |
645 | vl = list_entry(afs_vlocation_updates.next, |
646 | struct afs_vlocation, update); | |
647 | if (atomic_read(&vl->usage) > 0) | |
648 | break; | |
649 | list_del_init(&vl->update); | |
1da177e4 LT |
650 | } |
651 | ||
08e0e7c8 DH |
652 | timeout = vl->update_at - now; |
653 | if (timeout > 0) { | |
654 | queue_delayed_work(afs_vlocation_update_worker, | |
655 | &afs_vlocation_update, timeout * HZ); | |
656 | spin_unlock(&afs_vlocation_updates_lock); | |
657 | _leave(" [nothing]"); | |
1da177e4 LT |
658 | return; |
659 | } | |
660 | ||
08e0e7c8 DH |
661 | list_del_init(&vl->update); |
662 | atomic_inc(&vl->usage); | |
663 | spin_unlock(&afs_vlocation_updates_lock); | |
1da177e4 | 664 | |
08e0e7c8 DH |
665 | /* we can now perform the update */ |
666 | _debug("update %s", vl->vldb.name); | |
667 | vl->state = AFS_VL_UPDATING; | |
668 | vl->upd_rej_cnt = 0; | |
669 | vl->upd_busy_cnt = 0; | |
1da177e4 | 670 | |
00d3b7a4 | 671 | ret = afs_vlocation_update_record(vl, NULL, &vldb); |
39bf0949 | 672 | spin_lock(&vl->lock); |
08e0e7c8 DH |
673 | switch (ret) { |
674 | case 0: | |
675 | afs_vlocation_apply_update(vl, &vldb); | |
676 | vl->state = AFS_VL_VALID; | |
677 | break; | |
678 | case -ENOMEDIUM: | |
679 | vl->state = AFS_VL_VOLUME_DELETED; | |
680 | break; | |
681 | default: | |
682 | vl->state = AFS_VL_UNCERTAIN; | |
683 | break; | |
684 | } | |
39bf0949 | 685 | spin_unlock(&vl->lock); |
47051a21 | 686 | wake_up(&vl->waitq); |
1da177e4 | 687 | |
08e0e7c8 DH |
688 | /* and then reschedule */ |
689 | _debug("reschedule"); | |
690 | vl->update_at = get_seconds() + afs_vlocation_update_timeout; | |
1da177e4 | 691 | |
08e0e7c8 | 692 | spin_lock(&afs_vlocation_updates_lock); |
1da177e4 | 693 | |
08e0e7c8 DH |
694 | if (!list_empty(&afs_vlocation_updates)) { |
695 | /* next update in 10 minutes, but wait at least 1 second more | |
696 | * than the newest record already queued so that we don't spam | |
697 | * the VL server suddenly with lots of requests | |
698 | */ | |
699 | xvl = list_entry(afs_vlocation_updates.prev, | |
700 | struct afs_vlocation, update); | |
701 | if (vl->update_at <= xvl->update_at) | |
702 | vl->update_at = xvl->update_at + 1; | |
703 | xvl = list_entry(afs_vlocation_updates.next, | |
704 | struct afs_vlocation, update); | |
705 | timeout = xvl->update_at - now; | |
706 | if (timeout < 0) | |
707 | timeout = 0; | |
708 | } else { | |
709 | timeout = afs_vlocation_update_timeout; | |
1da177e4 LT |
710 | } |
711 | ||
08e0e7c8 | 712 | ASSERT(list_empty(&vl->update)); |
1da177e4 | 713 | |
08e0e7c8 | 714 | list_add_tail(&vl->update, &afs_vlocation_updates); |
1da177e4 | 715 | |
08e0e7c8 DH |
716 | _debug("timeout %ld", timeout); |
717 | queue_delayed_work(afs_vlocation_update_worker, | |
718 | &afs_vlocation_update, timeout * HZ); | |
719 | spin_unlock(&afs_vlocation_updates_lock); | |
720 | afs_put_vlocation(vl); | |
ec26815a | 721 | } |