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> | |
e8edc6e0 | 15 | #include <linux/sched.h> |
1da177e4 LT |
16 | #include "internal.h" |
17 | ||
c1206a2c AB |
18 | static unsigned afs_vlocation_timeout = 10; /* volume location timeout in seconds */ |
19 | static unsigned afs_vlocation_update_timeout = 10 * 60; | |
1da177e4 | 20 | |
08e0e7c8 DH |
21 | static void afs_vlocation_reaper(struct work_struct *); |
22 | static void afs_vlocation_updater(struct work_struct *); | |
1da177e4 | 23 | |
08e0e7c8 DH |
24 | static LIST_HEAD(afs_vlocation_updates); |
25 | static LIST_HEAD(afs_vlocation_graveyard); | |
26 | static DEFINE_SPINLOCK(afs_vlocation_updates_lock); | |
27 | static DEFINE_SPINLOCK(afs_vlocation_graveyard_lock); | |
28 | static DECLARE_DELAYED_WORK(afs_vlocation_reap, afs_vlocation_reaper); | |
29 | static DECLARE_DELAYED_WORK(afs_vlocation_update, afs_vlocation_updater); | |
30 | static struct workqueue_struct *afs_vlocation_update_worker; | |
1da177e4 | 31 | |
1da177e4 LT |
32 | /* |
33 | * iterate through the VL servers in a cell until one of them admits knowing | |
34 | * about the volume in question | |
1da177e4 | 35 | */ |
08e0e7c8 | 36 | static int afs_vlocation_access_vl_by_name(struct afs_vlocation *vl, |
00d3b7a4 | 37 | struct key *key, |
1da177e4 LT |
38 | struct afs_cache_vlocation *vldb) |
39 | { | |
08e0e7c8 DH |
40 | struct afs_cell *cell = vl->cell; |
41 | struct in_addr addr; | |
1da177e4 LT |
42 | int count, ret; |
43 | ||
08e0e7c8 | 44 | _enter("%s,%s", cell->name, vl->vldb.name); |
1da177e4 | 45 | |
08e0e7c8 | 46 | down_write(&vl->cell->vl_sem); |
1da177e4 LT |
47 | ret = -ENOMEDIUM; |
48 | for (count = cell->vl_naddrs; count > 0; count--) { | |
08e0e7c8 DH |
49 | addr = cell->vl_addrs[cell->vl_curr_svix]; |
50 | ||
51 | _debug("CellServ[%hu]: %08x", cell->vl_curr_svix, addr.s_addr); | |
1da177e4 LT |
52 | |
53 | /* attempt to access the VL server */ | |
00d3b7a4 | 54 | ret = afs_vl_get_entry_by_name(&addr, key, vl->vldb.name, vldb, |
08e0e7c8 | 55 | &afs_sync_call); |
1da177e4 LT |
56 | switch (ret) { |
57 | case 0: | |
1da177e4 LT |
58 | goto out; |
59 | case -ENOMEM: | |
60 | case -ENONET: | |
61 | case -ENETUNREACH: | |
62 | case -EHOSTUNREACH: | |
63 | case -ECONNREFUSED: | |
1da177e4 LT |
64 | if (ret == -ENOMEM || ret == -ENONET) |
65 | goto out; | |
66 | goto rotate; | |
67 | case -ENOMEDIUM: | |
005411c3 DH |
68 | case -EKEYREJECTED: |
69 | case -EKEYEXPIRED: | |
1da177e4 LT |
70 | goto out; |
71 | default: | |
08e0e7c8 | 72 | ret = -EIO; |
1da177e4 LT |
73 | goto rotate; |
74 | } | |
75 | ||
76 | /* rotate the server records upon lookup failure */ | |
77 | rotate: | |
78 | cell->vl_curr_svix++; | |
79 | cell->vl_curr_svix %= cell->vl_naddrs; | |
80 | } | |
81 | ||
ec26815a | 82 | out: |
08e0e7c8 | 83 | up_write(&vl->cell->vl_sem); |
1da177e4 LT |
84 | _leave(" = %d", ret); |
85 | return ret; | |
ec26815a | 86 | } |
1da177e4 | 87 | |
1da177e4 LT |
88 | /* |
89 | * iterate through the VL servers in a cell until one of them admits knowing | |
90 | * about the volume in question | |
1da177e4 | 91 | */ |
08e0e7c8 | 92 | static int afs_vlocation_access_vl_by_id(struct afs_vlocation *vl, |
00d3b7a4 | 93 | struct key *key, |
1da177e4 LT |
94 | afs_volid_t volid, |
95 | afs_voltype_t voltype, | |
96 | struct afs_cache_vlocation *vldb) | |
97 | { | |
08e0e7c8 DH |
98 | struct afs_cell *cell = vl->cell; |
99 | struct in_addr addr; | |
1da177e4 LT |
100 | int count, ret; |
101 | ||
102 | _enter("%s,%x,%d,", cell->name, volid, voltype); | |
103 | ||
08e0e7c8 | 104 | down_write(&vl->cell->vl_sem); |
1da177e4 LT |
105 | ret = -ENOMEDIUM; |
106 | for (count = cell->vl_naddrs; count > 0; count--) { | |
08e0e7c8 DH |
107 | addr = cell->vl_addrs[cell->vl_curr_svix]; |
108 | ||
109 | _debug("CellServ[%hu]: %08x", cell->vl_curr_svix, addr.s_addr); | |
1da177e4 LT |
110 | |
111 | /* attempt to access the VL server */ | |
00d3b7a4 | 112 | ret = afs_vl_get_entry_by_id(&addr, key, volid, voltype, vldb, |
08e0e7c8 | 113 | &afs_sync_call); |
1da177e4 LT |
114 | switch (ret) { |
115 | case 0: | |
1da177e4 LT |
116 | goto out; |
117 | case -ENOMEM: | |
118 | case -ENONET: | |
119 | case -ENETUNREACH: | |
120 | case -EHOSTUNREACH: | |
121 | case -ECONNREFUSED: | |
1da177e4 LT |
122 | if (ret == -ENOMEM || ret == -ENONET) |
123 | goto out; | |
124 | goto rotate; | |
08e0e7c8 DH |
125 | case -EBUSY: |
126 | vl->upd_busy_cnt++; | |
127 | if (vl->upd_busy_cnt <= 3) { | |
128 | if (vl->upd_busy_cnt > 1) { | |
129 | /* second+ BUSY - sleep a little bit */ | |
130 | set_current_state(TASK_UNINTERRUPTIBLE); | |
131 | schedule_timeout(1); | |
132 | __set_current_state(TASK_RUNNING); | |
133 | } | |
134 | continue; | |
135 | } | |
136 | break; | |
1da177e4 | 137 | case -ENOMEDIUM: |
08e0e7c8 DH |
138 | vl->upd_rej_cnt++; |
139 | goto rotate; | |
1da177e4 | 140 | default: |
08e0e7c8 | 141 | ret = -EIO; |
1da177e4 LT |
142 | goto rotate; |
143 | } | |
144 | ||
145 | /* rotate the server records upon lookup failure */ | |
146 | rotate: | |
147 | cell->vl_curr_svix++; | |
148 | cell->vl_curr_svix %= cell->vl_naddrs; | |
08e0e7c8 | 149 | vl->upd_busy_cnt = 0; |
1da177e4 LT |
150 | } |
151 | ||
ec26815a | 152 | out: |
08e0e7c8 DH |
153 | if (ret < 0 && vl->upd_rej_cnt > 0) { |
154 | printk(KERN_NOTICE "kAFS:" | |
155 | " Active volume no longer valid '%s'\n", | |
156 | vl->vldb.name); | |
157 | vl->valid = 0; | |
158 | ret = -ENOMEDIUM; | |
159 | } | |
160 | ||
161 | up_write(&vl->cell->vl_sem); | |
1da177e4 LT |
162 | _leave(" = %d", ret); |
163 | return ret; | |
ec26815a | 164 | } |
1da177e4 | 165 | |
1da177e4 | 166 | /* |
08e0e7c8 | 167 | * allocate a volume location record |
1da177e4 | 168 | */ |
08e0e7c8 DH |
169 | static struct afs_vlocation *afs_vlocation_alloc(struct afs_cell *cell, |
170 | const char *name, | |
171 | size_t namesz) | |
1da177e4 | 172 | { |
08e0e7c8 DH |
173 | struct afs_vlocation *vl; |
174 | ||
175 | vl = kzalloc(sizeof(struct afs_vlocation), GFP_KERNEL); | |
176 | if (vl) { | |
177 | vl->cell = cell; | |
178 | vl->state = AFS_VL_NEW; | |
179 | atomic_set(&vl->usage, 1); | |
180 | INIT_LIST_HEAD(&vl->link); | |
181 | INIT_LIST_HEAD(&vl->grave); | |
182 | INIT_LIST_HEAD(&vl->update); | |
183 | init_waitqueue_head(&vl->waitq); | |
39bf0949 | 184 | spin_lock_init(&vl->lock); |
08e0e7c8 | 185 | memcpy(vl->vldb.name, name, namesz); |
1da177e4 LT |
186 | } |
187 | ||
08e0e7c8 DH |
188 | _leave(" = %p", vl); |
189 | return vl; | |
190 | } | |
1da177e4 | 191 | |
08e0e7c8 DH |
192 | /* |
193 | * update record if we found it in the cache | |
194 | */ | |
195 | static int afs_vlocation_update_record(struct afs_vlocation *vl, | |
00d3b7a4 | 196 | struct key *key, |
08e0e7c8 DH |
197 | struct afs_cache_vlocation *vldb) |
198 | { | |
199 | afs_voltype_t voltype; | |
200 | afs_volid_t vid; | |
201 | int ret; | |
1da177e4 | 202 | |
1da177e4 | 203 | /* try to look up a cached volume in the cell VL databases by ID */ |
1da177e4 | 204 | _debug("Locally Cached: %s %02x { %08x(%x) %08x(%x) %08x(%x) }", |
08e0e7c8 DH |
205 | vl->vldb.name, |
206 | vl->vldb.vidmask, | |
207 | ntohl(vl->vldb.servers[0].s_addr), | |
208 | vl->vldb.srvtmask[0], | |
209 | ntohl(vl->vldb.servers[1].s_addr), | |
210 | vl->vldb.srvtmask[1], | |
211 | ntohl(vl->vldb.servers[2].s_addr), | |
212 | vl->vldb.srvtmask[2]); | |
1da177e4 LT |
213 | |
214 | _debug("Vids: %08x %08x %08x", | |
08e0e7c8 DH |
215 | vl->vldb.vid[0], |
216 | vl->vldb.vid[1], | |
217 | vl->vldb.vid[2]); | |
1da177e4 | 218 | |
08e0e7c8 DH |
219 | if (vl->vldb.vidmask & AFS_VOL_VTM_RW) { |
220 | vid = vl->vldb.vid[0]; | |
1da177e4 | 221 | voltype = AFSVL_RWVOL; |
08e0e7c8 DH |
222 | } else if (vl->vldb.vidmask & AFS_VOL_VTM_RO) { |
223 | vid = vl->vldb.vid[1]; | |
1da177e4 | 224 | voltype = AFSVL_ROVOL; |
08e0e7c8 DH |
225 | } else if (vl->vldb.vidmask & AFS_VOL_VTM_BAK) { |
226 | vid = vl->vldb.vid[2]; | |
1da177e4 | 227 | voltype = AFSVL_BACKVOL; |
ec26815a | 228 | } else { |
1da177e4 LT |
229 | BUG(); |
230 | vid = 0; | |
231 | voltype = 0; | |
232 | } | |
233 | ||
08e0e7c8 DH |
234 | /* contact the server to make sure the volume is still available |
235 | * - TODO: need to handle disconnected operation here | |
236 | */ | |
00d3b7a4 | 237 | ret = afs_vlocation_access_vl_by_id(vl, key, vid, voltype, vldb); |
1da177e4 LT |
238 | switch (ret) { |
239 | /* net error */ | |
240 | default: | |
08e0e7c8 DH |
241 | printk(KERN_WARNING "kAFS:" |
242 | " failed to update volume '%s' (%x) up in '%s': %d\n", | |
243 | vl->vldb.name, vid, vl->cell->name, ret); | |
244 | _leave(" = %d", ret); | |
245 | return ret; | |
1da177e4 LT |
246 | |
247 | /* pulled from local cache into memory */ | |
248 | case 0: | |
08e0e7c8 DH |
249 | _leave(" = 0"); |
250 | return 0; | |
1da177e4 LT |
251 | |
252 | /* uh oh... looks like the volume got deleted */ | |
253 | case -ENOMEDIUM: | |
08e0e7c8 DH |
254 | printk(KERN_ERR "kAFS:" |
255 | " volume '%s' (%x) does not exist '%s'\n", | |
256 | vl->vldb.name, vid, vl->cell->name); | |
1da177e4 LT |
257 | |
258 | /* TODO: make existing record unavailable */ | |
08e0e7c8 DH |
259 | _leave(" = %d", ret); |
260 | return ret; | |
1da177e4 | 261 | } |
08e0e7c8 | 262 | } |
1da177e4 | 263 | |
08e0e7c8 DH |
264 | /* |
265 | * apply the update to a VL record | |
266 | */ | |
267 | static void afs_vlocation_apply_update(struct afs_vlocation *vl, | |
268 | struct afs_cache_vlocation *vldb) | |
269 | { | |
270 | _debug("Done VL Lookup: %s %02x { %08x(%x) %08x(%x) %08x(%x) }", | |
271 | vldb->name, vldb->vidmask, | |
272 | ntohl(vldb->servers[0].s_addr), vldb->srvtmask[0], | |
273 | ntohl(vldb->servers[1].s_addr), vldb->srvtmask[1], | |
274 | ntohl(vldb->servers[2].s_addr), vldb->srvtmask[2]); | |
1da177e4 | 275 | |
08e0e7c8 DH |
276 | _debug("Vids: %08x %08x %08x", |
277 | vldb->vid[0], vldb->vid[1], vldb->vid[2]); | |
1da177e4 | 278 | |
08e0e7c8 DH |
279 | if (strcmp(vldb->name, vl->vldb.name) != 0) |
280 | printk(KERN_NOTICE "kAFS:" | |
281 | " name of volume '%s' changed to '%s' on server\n", | |
282 | vl->vldb.name, vldb->name); | |
1da177e4 | 283 | |
08e0e7c8 | 284 | vl->vldb = *vldb; |
1da177e4 | 285 | |
9b3f26c9 DH |
286 | #ifdef CONFIG_AFS_FSCACHE |
287 | fscache_update_cookie(vl->cache); | |
1da177e4 | 288 | #endif |
ec26815a | 289 | } |
1da177e4 | 290 | |
1da177e4 | 291 | /* |
08e0e7c8 DH |
292 | * fill in a volume location record, consulting the cache and the VL server |
293 | * both | |
1da177e4 | 294 | */ |
00d3b7a4 DH |
295 | static int afs_vlocation_fill_in_record(struct afs_vlocation *vl, |
296 | struct key *key) | |
1da177e4 | 297 | { |
08e0e7c8 DH |
298 | struct afs_cache_vlocation vldb; |
299 | int ret; | |
1da177e4 | 300 | |
08e0e7c8 | 301 | _enter(""); |
1da177e4 | 302 | |
08e0e7c8 | 303 | ASSERTCMP(vl->valid, ==, 0); |
1da177e4 | 304 | |
08e0e7c8 | 305 | memset(&vldb, 0, sizeof(vldb)); |
1da177e4 | 306 | |
08e0e7c8 | 307 | /* see if we have an in-cache copy (will set vl->valid if there is) */ |
9b3f26c9 DH |
308 | #ifdef CONFIG_AFS_FSCACHE |
309 | vl->cache = fscache_acquire_cookie(vl->cell->cache, | |
310 | &afs_vlocation_cache_index_def, vl); | |
08e0e7c8 | 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 | */ |
c1206a2c | 337 | static 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 | |
6551198a | 384 | if (namesz >= sizeof(vl->vldb.name)) { |
08e0e7c8 DH |
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 | |
9b3f26c9 DH |
422 | /* update volume entry in local cache */ |
423 | #ifdef CONFIG_AFS_FSCACHE | |
424 | fscache_update_cookie(vl->cache); | |
425 | #endif | |
426 | ||
08e0e7c8 DH |
427 | /* schedule for regular updates */ |
428 | afs_vlocation_queue_for_updates(vl); | |
429 | goto success; | |
1da177e4 | 430 | |
08e0e7c8 DH |
431 | found_in_memory: |
432 | /* found in memory */ | |
433 | _debug("found in memory"); | |
434 | atomic_inc(&vl->usage); | |
435 | spin_unlock(&cell->vl_lock); | |
436 | if (!list_empty(&vl->grave)) { | |
437 | spin_lock(&afs_vlocation_graveyard_lock); | |
438 | list_del_init(&vl->grave); | |
439 | spin_unlock(&afs_vlocation_graveyard_lock); | |
1da177e4 | 440 | } |
08e0e7c8 | 441 | up_write(&cell->vl_sem); |
1da177e4 | 442 | |
08e0e7c8 | 443 | /* see if it was an abandoned record that we might try filling in */ |
39bf0949 | 444 | spin_lock(&vl->lock); |
08e0e7c8 DH |
445 | while (vl->state != AFS_VL_VALID) { |
446 | afs_vlocation_state_t state = vl->state; | |
1da177e4 | 447 | |
08e0e7c8 | 448 | _debug("invalid [state %d]", state); |
1da177e4 | 449 | |
47051a21 | 450 | if (state == AFS_VL_NEW || state == AFS_VL_NO_VOLUME) { |
39bf0949 DM |
451 | vl->state = AFS_VL_CREATING; |
452 | spin_unlock(&vl->lock); | |
453 | goto fill_in_record; | |
08e0e7c8 DH |
454 | } |
455 | ||
456 | /* must now wait for creation or update by someone else to | |
457 | * complete */ | |
458 | _debug("wait"); | |
459 | ||
39bf0949 | 460 | spin_unlock(&vl->lock); |
47051a21 DH |
461 | ret = wait_event_interruptible(vl->waitq, |
462 | vl->state == AFS_VL_NEW || | |
463 | vl->state == AFS_VL_VALID || | |
464 | vl->state == AFS_VL_NO_VOLUME); | |
08e0e7c8 DH |
465 | if (ret < 0) |
466 | goto error; | |
39bf0949 | 467 | spin_lock(&vl->lock); |
1da177e4 | 468 | } |
39bf0949 | 469 | spin_unlock(&vl->lock); |
1da177e4 | 470 | |
08e0e7c8 | 471 | success: |
9b3f26c9 | 472 | _leave(" = %p", vl); |
08e0e7c8 DH |
473 | return vl; |
474 | ||
475 | error_abandon: | |
39bf0949 | 476 | spin_lock(&vl->lock); |
08e0e7c8 | 477 | vl->state = AFS_VL_NEW; |
39bf0949 | 478 | spin_unlock(&vl->lock); |
47051a21 | 479 | wake_up(&vl->waitq); |
08e0e7c8 DH |
480 | error: |
481 | ASSERT(vl != NULL); | |
482 | afs_put_vlocation(vl); | |
1da177e4 | 483 | _leave(" = %d", ret); |
08e0e7c8 | 484 | return ERR_PTR(ret); |
ec26815a | 485 | } |
1da177e4 | 486 | |
1da177e4 | 487 | /* |
08e0e7c8 | 488 | * finish using a volume location record |
1da177e4 | 489 | */ |
08e0e7c8 | 490 | void afs_put_vlocation(struct afs_vlocation *vl) |
1da177e4 | 491 | { |
08e0e7c8 DH |
492 | if (!vl) |
493 | return; | |
1da177e4 | 494 | |
08e0e7c8 | 495 | _enter("%s", vl->vldb.name); |
1da177e4 | 496 | |
08e0e7c8 | 497 | ASSERTCMP(atomic_read(&vl->usage), >, 0); |
1da177e4 | 498 | |
08e0e7c8 DH |
499 | if (likely(!atomic_dec_and_test(&vl->usage))) { |
500 | _leave(""); | |
501 | return; | |
502 | } | |
1da177e4 | 503 | |
08e0e7c8 DH |
504 | spin_lock(&afs_vlocation_graveyard_lock); |
505 | if (atomic_read(&vl->usage) == 0) { | |
506 | _debug("buried"); | |
507 | list_move_tail(&vl->grave, &afs_vlocation_graveyard); | |
508 | vl->time_of_death = get_seconds(); | |
509 | schedule_delayed_work(&afs_vlocation_reap, | |
510 | afs_vlocation_timeout * HZ); | |
511 | ||
512 | /* suspend updates on this record */ | |
513 | if (!list_empty(&vl->update)) { | |
514 | spin_lock(&afs_vlocation_updates_lock); | |
515 | list_del_init(&vl->update); | |
516 | spin_unlock(&afs_vlocation_updates_lock); | |
517 | } | |
518 | } | |
519 | spin_unlock(&afs_vlocation_graveyard_lock); | |
520 | _leave(" [killed?]"); | |
ec26815a | 521 | } |
1da177e4 | 522 | |
1da177e4 | 523 | /* |
08e0e7c8 | 524 | * destroy a dead volume location record |
1da177e4 | 525 | */ |
08e0e7c8 | 526 | static void afs_vlocation_destroy(struct afs_vlocation *vl) |
1da177e4 | 527 | { |
08e0e7c8 | 528 | _enter("%p", vl); |
1da177e4 | 529 | |
9b3f26c9 DH |
530 | #ifdef CONFIG_AFS_FSCACHE |
531 | fscache_relinquish_cookie(vl->cache, 0); | |
08e0e7c8 | 532 | #endif |
08e0e7c8 DH |
533 | afs_put_cell(vl->cell); |
534 | kfree(vl); | |
535 | } | |
536 | ||
537 | /* | |
538 | * reap dead volume location records | |
539 | */ | |
540 | static void afs_vlocation_reaper(struct work_struct *work) | |
541 | { | |
542 | LIST_HEAD(corpses); | |
543 | struct afs_vlocation *vl; | |
544 | unsigned long delay, expiry; | |
545 | time_t now; | |
1da177e4 | 546 | |
08e0e7c8 | 547 | _enter(""); |
1da177e4 | 548 | |
08e0e7c8 DH |
549 | now = get_seconds(); |
550 | spin_lock(&afs_vlocation_graveyard_lock); | |
551 | ||
552 | while (!list_empty(&afs_vlocation_graveyard)) { | |
553 | vl = list_entry(afs_vlocation_graveyard.next, | |
554 | struct afs_vlocation, grave); | |
555 | ||
556 | _debug("check %p", vl); | |
557 | ||
558 | /* the queue is ordered most dead first */ | |
559 | expiry = vl->time_of_death + afs_vlocation_timeout; | |
560 | if (expiry > now) { | |
561 | delay = (expiry - now) * HZ; | |
562 | _debug("delay %lu", delay); | |
563 | if (!schedule_delayed_work(&afs_vlocation_reap, | |
564 | delay)) { | |
565 | cancel_delayed_work(&afs_vlocation_reap); | |
566 | schedule_delayed_work(&afs_vlocation_reap, | |
567 | delay); | |
568 | } | |
569 | break; | |
570 | } | |
1da177e4 | 571 | |
08e0e7c8 DH |
572 | spin_lock(&vl->cell->vl_lock); |
573 | if (atomic_read(&vl->usage) > 0) { | |
574 | _debug("no reap"); | |
575 | list_del_init(&vl->grave); | |
ec26815a | 576 | } else { |
08e0e7c8 DH |
577 | _debug("reap"); |
578 | list_move_tail(&vl->grave, &corpses); | |
579 | list_del_init(&vl->link); | |
1da177e4 | 580 | } |
08e0e7c8 | 581 | spin_unlock(&vl->cell->vl_lock); |
1da177e4 LT |
582 | } |
583 | ||
08e0e7c8 | 584 | spin_unlock(&afs_vlocation_graveyard_lock); |
1da177e4 | 585 | |
08e0e7c8 DH |
586 | /* now reap the corpses we've extracted */ |
587 | while (!list_empty(&corpses)) { | |
588 | vl = list_entry(corpses.next, struct afs_vlocation, grave); | |
589 | list_del(&vl->grave); | |
590 | afs_vlocation_destroy(vl); | |
1da177e4 LT |
591 | } |
592 | ||
593 | _leave(""); | |
08e0e7c8 | 594 | } |
1da177e4 | 595 | |
08e0e7c8 DH |
596 | /* |
597 | * initialise the VL update process | |
598 | */ | |
599 | int __init afs_vlocation_update_init(void) | |
600 | { | |
601 | afs_vlocation_update_worker = | |
602 | create_singlethread_workqueue("kafs_vlupdated"); | |
603 | return afs_vlocation_update_worker ? 0 : -ENOMEM; | |
604 | } | |
605 | ||
606 | /* | |
607 | * discard all the volume location records for rmmod | |
608 | */ | |
fbb3fcba | 609 | void afs_vlocation_purge(void) |
08e0e7c8 DH |
610 | { |
611 | afs_vlocation_timeout = 0; | |
612 | ||
613 | spin_lock(&afs_vlocation_updates_lock); | |
614 | list_del_init(&afs_vlocation_updates); | |
615 | spin_unlock(&afs_vlocation_updates_lock); | |
616 | cancel_delayed_work(&afs_vlocation_update); | |
617 | queue_delayed_work(afs_vlocation_update_worker, | |
618 | &afs_vlocation_update, 0); | |
619 | destroy_workqueue(afs_vlocation_update_worker); | |
620 | ||
621 | cancel_delayed_work(&afs_vlocation_reap); | |
622 | schedule_delayed_work(&afs_vlocation_reap, 0); | |
ec26815a | 623 | } |
1da177e4 | 624 | |
1da177e4 | 625 | /* |
08e0e7c8 | 626 | * update a volume location |
1da177e4 | 627 | */ |
08e0e7c8 | 628 | static void afs_vlocation_updater(struct work_struct *work) |
1da177e4 LT |
629 | { |
630 | struct afs_cache_vlocation vldb; | |
08e0e7c8 DH |
631 | struct afs_vlocation *vl, *xvl; |
632 | time_t now; | |
633 | long timeout; | |
1da177e4 LT |
634 | int ret; |
635 | ||
08e0e7c8 | 636 | _enter(""); |
1da177e4 | 637 | |
08e0e7c8 | 638 | now = get_seconds(); |
1da177e4 | 639 | |
08e0e7c8 DH |
640 | /* find a record to update */ |
641 | spin_lock(&afs_vlocation_updates_lock); | |
642 | for (;;) { | |
643 | if (list_empty(&afs_vlocation_updates)) { | |
644 | spin_unlock(&afs_vlocation_updates_lock); | |
645 | _leave(" [nothing]"); | |
646 | return; | |
647 | } | |
1da177e4 | 648 | |
08e0e7c8 DH |
649 | vl = list_entry(afs_vlocation_updates.next, |
650 | struct afs_vlocation, update); | |
651 | if (atomic_read(&vl->usage) > 0) | |
652 | break; | |
653 | list_del_init(&vl->update); | |
1da177e4 LT |
654 | } |
655 | ||
08e0e7c8 DH |
656 | timeout = vl->update_at - now; |
657 | if (timeout > 0) { | |
658 | queue_delayed_work(afs_vlocation_update_worker, | |
659 | &afs_vlocation_update, timeout * HZ); | |
660 | spin_unlock(&afs_vlocation_updates_lock); | |
661 | _leave(" [nothing]"); | |
1da177e4 LT |
662 | return; |
663 | } | |
664 | ||
08e0e7c8 DH |
665 | list_del_init(&vl->update); |
666 | atomic_inc(&vl->usage); | |
667 | spin_unlock(&afs_vlocation_updates_lock); | |
1da177e4 | 668 | |
08e0e7c8 DH |
669 | /* we can now perform the update */ |
670 | _debug("update %s", vl->vldb.name); | |
671 | vl->state = AFS_VL_UPDATING; | |
672 | vl->upd_rej_cnt = 0; | |
673 | vl->upd_busy_cnt = 0; | |
1da177e4 | 674 | |
00d3b7a4 | 675 | ret = afs_vlocation_update_record(vl, NULL, &vldb); |
39bf0949 | 676 | spin_lock(&vl->lock); |
08e0e7c8 DH |
677 | switch (ret) { |
678 | case 0: | |
679 | afs_vlocation_apply_update(vl, &vldb); | |
680 | vl->state = AFS_VL_VALID; | |
681 | break; | |
682 | case -ENOMEDIUM: | |
683 | vl->state = AFS_VL_VOLUME_DELETED; | |
684 | break; | |
685 | default: | |
686 | vl->state = AFS_VL_UNCERTAIN; | |
687 | break; | |
688 | } | |
39bf0949 | 689 | spin_unlock(&vl->lock); |
47051a21 | 690 | wake_up(&vl->waitq); |
1da177e4 | 691 | |
08e0e7c8 DH |
692 | /* and then reschedule */ |
693 | _debug("reschedule"); | |
694 | vl->update_at = get_seconds() + afs_vlocation_update_timeout; | |
1da177e4 | 695 | |
08e0e7c8 | 696 | spin_lock(&afs_vlocation_updates_lock); |
1da177e4 | 697 | |
08e0e7c8 DH |
698 | if (!list_empty(&afs_vlocation_updates)) { |
699 | /* next update in 10 minutes, but wait at least 1 second more | |
700 | * than the newest record already queued so that we don't spam | |
701 | * the VL server suddenly with lots of requests | |
702 | */ | |
703 | xvl = list_entry(afs_vlocation_updates.prev, | |
704 | struct afs_vlocation, update); | |
705 | if (vl->update_at <= xvl->update_at) | |
706 | vl->update_at = xvl->update_at + 1; | |
707 | xvl = list_entry(afs_vlocation_updates.next, | |
708 | struct afs_vlocation, update); | |
709 | timeout = xvl->update_at - now; | |
710 | if (timeout < 0) | |
711 | timeout = 0; | |
712 | } else { | |
713 | timeout = afs_vlocation_update_timeout; | |
1da177e4 LT |
714 | } |
715 | ||
08e0e7c8 | 716 | ASSERT(list_empty(&vl->update)); |
1da177e4 | 717 | |
08e0e7c8 | 718 | list_add_tail(&vl->update, &afs_vlocation_updates); |
1da177e4 | 719 | |
08e0e7c8 DH |
720 | _debug("timeout %ld", timeout); |
721 | queue_delayed_work(afs_vlocation_update_worker, | |
722 | &afs_vlocation_update, timeout * HZ); | |
723 | spin_unlock(&afs_vlocation_updates_lock); | |
724 | afs_put_vlocation(vl); | |
ec26815a | 725 | } |