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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> | |
5a0e3ad6 | 14 | #include <linux/slab.h> |
1da177e4 | 15 | #include <linux/init.h> |
e8edc6e0 | 16 | #include <linux/sched.h> |
1da177e4 LT |
17 | #include "internal.h" |
18 | ||
c1206a2c AB |
19 | static unsigned afs_vlocation_timeout = 10; /* volume location timeout in seconds */ |
20 | static unsigned afs_vlocation_update_timeout = 10 * 60; | |
1da177e4 | 21 | |
08e0e7c8 DH |
22 | static void afs_vlocation_reaper(struct work_struct *); |
23 | static void afs_vlocation_updater(struct work_struct *); | |
1da177e4 | 24 | |
08e0e7c8 DH |
25 | static LIST_HEAD(afs_vlocation_updates); |
26 | static LIST_HEAD(afs_vlocation_graveyard); | |
27 | static DEFINE_SPINLOCK(afs_vlocation_updates_lock); | |
28 | static DEFINE_SPINLOCK(afs_vlocation_graveyard_lock); | |
29 | static DECLARE_DELAYED_WORK(afs_vlocation_reap, afs_vlocation_reaper); | |
30 | static DECLARE_DELAYED_WORK(afs_vlocation_update, afs_vlocation_updater); | |
31 | static struct workqueue_struct *afs_vlocation_update_worker; | |
1da177e4 | 32 | |
1da177e4 LT |
33 | /* |
34 | * iterate through the VL servers in a cell until one of them admits knowing | |
35 | * about the volume in question | |
1da177e4 | 36 | */ |
08e0e7c8 | 37 | static int afs_vlocation_access_vl_by_name(struct afs_vlocation *vl, |
00d3b7a4 | 38 | struct key *key, |
1da177e4 LT |
39 | struct afs_cache_vlocation *vldb) |
40 | { | |
08e0e7c8 DH |
41 | struct afs_cell *cell = vl->cell; |
42 | struct in_addr addr; | |
1da177e4 LT |
43 | int count, ret; |
44 | ||
08e0e7c8 | 45 | _enter("%s,%s", cell->name, vl->vldb.name); |
1da177e4 | 46 | |
08e0e7c8 | 47 | down_write(&vl->cell->vl_sem); |
1da177e4 LT |
48 | ret = -ENOMEDIUM; |
49 | for (count = cell->vl_naddrs; count > 0; count--) { | |
08e0e7c8 DH |
50 | addr = cell->vl_addrs[cell->vl_curr_svix]; |
51 | ||
52 | _debug("CellServ[%hu]: %08x", cell->vl_curr_svix, addr.s_addr); | |
1da177e4 LT |
53 | |
54 | /* attempt to access the VL server */ | |
00d3b7a4 | 55 | ret = afs_vl_get_entry_by_name(&addr, key, vl->vldb.name, vldb, |
08e0e7c8 | 56 | &afs_sync_call); |
1da177e4 LT |
57 | switch (ret) { |
58 | case 0: | |
1da177e4 LT |
59 | goto out; |
60 | case -ENOMEM: | |
61 | case -ENONET: | |
62 | case -ENETUNREACH: | |
63 | case -EHOSTUNREACH: | |
64 | case -ECONNREFUSED: | |
1da177e4 LT |
65 | if (ret == -ENOMEM || ret == -ENONET) |
66 | goto out; | |
67 | goto rotate; | |
68 | case -ENOMEDIUM: | |
005411c3 DH |
69 | case -EKEYREJECTED: |
70 | case -EKEYEXPIRED: | |
1da177e4 LT |
71 | goto out; |
72 | default: | |
08e0e7c8 | 73 | ret = -EIO; |
1da177e4 LT |
74 | goto rotate; |
75 | } | |
76 | ||
77 | /* rotate the server records upon lookup failure */ | |
78 | rotate: | |
79 | cell->vl_curr_svix++; | |
80 | cell->vl_curr_svix %= cell->vl_naddrs; | |
81 | } | |
82 | ||
ec26815a | 83 | out: |
08e0e7c8 | 84 | up_write(&vl->cell->vl_sem); |
1da177e4 LT |
85 | _leave(" = %d", ret); |
86 | return ret; | |
ec26815a | 87 | } |
1da177e4 | 88 | |
1da177e4 LT |
89 | /* |
90 | * iterate through the VL servers in a cell until one of them admits knowing | |
91 | * about the volume in question | |
1da177e4 | 92 | */ |
08e0e7c8 | 93 | static int afs_vlocation_access_vl_by_id(struct afs_vlocation *vl, |
00d3b7a4 | 94 | struct key *key, |
1da177e4 LT |
95 | afs_volid_t volid, |
96 | afs_voltype_t voltype, | |
97 | struct afs_cache_vlocation *vldb) | |
98 | { | |
08e0e7c8 DH |
99 | struct afs_cell *cell = vl->cell; |
100 | struct in_addr addr; | |
1da177e4 LT |
101 | int count, ret; |
102 | ||
103 | _enter("%s,%x,%d,", cell->name, volid, voltype); | |
104 | ||
08e0e7c8 | 105 | down_write(&vl->cell->vl_sem); |
1da177e4 LT |
106 | ret = -ENOMEDIUM; |
107 | for (count = cell->vl_naddrs; count > 0; count--) { | |
08e0e7c8 DH |
108 | addr = cell->vl_addrs[cell->vl_curr_svix]; |
109 | ||
110 | _debug("CellServ[%hu]: %08x", cell->vl_curr_svix, addr.s_addr); | |
1da177e4 LT |
111 | |
112 | /* attempt to access the VL server */ | |
00d3b7a4 | 113 | ret = afs_vl_get_entry_by_id(&addr, key, volid, voltype, vldb, |
08e0e7c8 | 114 | &afs_sync_call); |
1da177e4 LT |
115 | switch (ret) { |
116 | case 0: | |
1da177e4 LT |
117 | goto out; |
118 | case -ENOMEM: | |
119 | case -ENONET: | |
120 | case -ENETUNREACH: | |
121 | case -EHOSTUNREACH: | |
122 | case -ECONNREFUSED: | |
1da177e4 LT |
123 | if (ret == -ENOMEM || ret == -ENONET) |
124 | goto out; | |
125 | goto rotate; | |
08e0e7c8 DH |
126 | case -EBUSY: |
127 | vl->upd_busy_cnt++; | |
128 | if (vl->upd_busy_cnt <= 3) { | |
129 | if (vl->upd_busy_cnt > 1) { | |
130 | /* second+ BUSY - sleep a little bit */ | |
131 | set_current_state(TASK_UNINTERRUPTIBLE); | |
132 | schedule_timeout(1); | |
133 | __set_current_state(TASK_RUNNING); | |
134 | } | |
135 | continue; | |
136 | } | |
137 | break; | |
1da177e4 | 138 | case -ENOMEDIUM: |
08e0e7c8 DH |
139 | vl->upd_rej_cnt++; |
140 | goto rotate; | |
1da177e4 | 141 | default: |
08e0e7c8 | 142 | ret = -EIO; |
1da177e4 LT |
143 | goto rotate; |
144 | } | |
145 | ||
146 | /* rotate the server records upon lookup failure */ | |
147 | rotate: | |
148 | cell->vl_curr_svix++; | |
149 | cell->vl_curr_svix %= cell->vl_naddrs; | |
08e0e7c8 | 150 | vl->upd_busy_cnt = 0; |
1da177e4 LT |
151 | } |
152 | ||
ec26815a | 153 | out: |
08e0e7c8 DH |
154 | if (ret < 0 && vl->upd_rej_cnt > 0) { |
155 | printk(KERN_NOTICE "kAFS:" | |
156 | " Active volume no longer valid '%s'\n", | |
157 | vl->vldb.name); | |
158 | vl->valid = 0; | |
159 | ret = -ENOMEDIUM; | |
160 | } | |
161 | ||
162 | up_write(&vl->cell->vl_sem); | |
1da177e4 LT |
163 | _leave(" = %d", ret); |
164 | return ret; | |
ec26815a | 165 | } |
1da177e4 | 166 | |
1da177e4 | 167 | /* |
08e0e7c8 | 168 | * allocate a volume location record |
1da177e4 | 169 | */ |
08e0e7c8 DH |
170 | static struct afs_vlocation *afs_vlocation_alloc(struct afs_cell *cell, |
171 | const char *name, | |
172 | size_t namesz) | |
1da177e4 | 173 | { |
08e0e7c8 DH |
174 | struct afs_vlocation *vl; |
175 | ||
176 | vl = kzalloc(sizeof(struct afs_vlocation), GFP_KERNEL); | |
177 | if (vl) { | |
178 | vl->cell = cell; | |
179 | vl->state = AFS_VL_NEW; | |
180 | atomic_set(&vl->usage, 1); | |
181 | INIT_LIST_HEAD(&vl->link); | |
182 | INIT_LIST_HEAD(&vl->grave); | |
183 | INIT_LIST_HEAD(&vl->update); | |
184 | init_waitqueue_head(&vl->waitq); | |
39bf0949 | 185 | spin_lock_init(&vl->lock); |
08e0e7c8 | 186 | memcpy(vl->vldb.name, name, namesz); |
1da177e4 LT |
187 | } |
188 | ||
08e0e7c8 DH |
189 | _leave(" = %p", vl); |
190 | return vl; | |
191 | } | |
1da177e4 | 192 | |
08e0e7c8 DH |
193 | /* |
194 | * update record if we found it in the cache | |
195 | */ | |
196 | static int afs_vlocation_update_record(struct afs_vlocation *vl, | |
00d3b7a4 | 197 | struct key *key, |
08e0e7c8 DH |
198 | struct afs_cache_vlocation *vldb) |
199 | { | |
200 | afs_voltype_t voltype; | |
201 | afs_volid_t vid; | |
202 | int ret; | |
1da177e4 | 203 | |
1da177e4 | 204 | /* try to look up a cached volume in the cell VL databases by ID */ |
1da177e4 | 205 | _debug("Locally Cached: %s %02x { %08x(%x) %08x(%x) %08x(%x) }", |
08e0e7c8 DH |
206 | vl->vldb.name, |
207 | vl->vldb.vidmask, | |
208 | ntohl(vl->vldb.servers[0].s_addr), | |
209 | vl->vldb.srvtmask[0], | |
210 | ntohl(vl->vldb.servers[1].s_addr), | |
211 | vl->vldb.srvtmask[1], | |
212 | ntohl(vl->vldb.servers[2].s_addr), | |
213 | vl->vldb.srvtmask[2]); | |
1da177e4 LT |
214 | |
215 | _debug("Vids: %08x %08x %08x", | |
08e0e7c8 DH |
216 | vl->vldb.vid[0], |
217 | vl->vldb.vid[1], | |
218 | vl->vldb.vid[2]); | |
1da177e4 | 219 | |
08e0e7c8 DH |
220 | if (vl->vldb.vidmask & AFS_VOL_VTM_RW) { |
221 | vid = vl->vldb.vid[0]; | |
1da177e4 | 222 | voltype = AFSVL_RWVOL; |
08e0e7c8 DH |
223 | } else if (vl->vldb.vidmask & AFS_VOL_VTM_RO) { |
224 | vid = vl->vldb.vid[1]; | |
1da177e4 | 225 | voltype = AFSVL_ROVOL; |
08e0e7c8 DH |
226 | } else if (vl->vldb.vidmask & AFS_VOL_VTM_BAK) { |
227 | vid = vl->vldb.vid[2]; | |
1da177e4 | 228 | voltype = AFSVL_BACKVOL; |
ec26815a | 229 | } else { |
1da177e4 LT |
230 | BUG(); |
231 | vid = 0; | |
232 | voltype = 0; | |
233 | } | |
234 | ||
08e0e7c8 DH |
235 | /* contact the server to make sure the volume is still available |
236 | * - TODO: need to handle disconnected operation here | |
237 | */ | |
00d3b7a4 | 238 | ret = afs_vlocation_access_vl_by_id(vl, key, vid, voltype, vldb); |
1da177e4 LT |
239 | switch (ret) { |
240 | /* net error */ | |
241 | default: | |
08e0e7c8 DH |
242 | printk(KERN_WARNING "kAFS:" |
243 | " failed to update volume '%s' (%x) up in '%s': %d\n", | |
244 | vl->vldb.name, vid, vl->cell->name, ret); | |
245 | _leave(" = %d", ret); | |
246 | return ret; | |
1da177e4 LT |
247 | |
248 | /* pulled from local cache into memory */ | |
249 | case 0: | |
08e0e7c8 DH |
250 | _leave(" = 0"); |
251 | return 0; | |
1da177e4 LT |
252 | |
253 | /* uh oh... looks like the volume got deleted */ | |
254 | case -ENOMEDIUM: | |
08e0e7c8 DH |
255 | printk(KERN_ERR "kAFS:" |
256 | " volume '%s' (%x) does not exist '%s'\n", | |
257 | vl->vldb.name, vid, vl->cell->name); | |
1da177e4 LT |
258 | |
259 | /* TODO: make existing record unavailable */ | |
08e0e7c8 DH |
260 | _leave(" = %d", ret); |
261 | return ret; | |
1da177e4 | 262 | } |
08e0e7c8 | 263 | } |
1da177e4 | 264 | |
08e0e7c8 DH |
265 | /* |
266 | * apply the update to a VL record | |
267 | */ | |
268 | static void afs_vlocation_apply_update(struct afs_vlocation *vl, | |
269 | struct afs_cache_vlocation *vldb) | |
270 | { | |
271 | _debug("Done VL Lookup: %s %02x { %08x(%x) %08x(%x) %08x(%x) }", | |
272 | vldb->name, vldb->vidmask, | |
273 | ntohl(vldb->servers[0].s_addr), vldb->srvtmask[0], | |
274 | ntohl(vldb->servers[1].s_addr), vldb->srvtmask[1], | |
275 | ntohl(vldb->servers[2].s_addr), vldb->srvtmask[2]); | |
1da177e4 | 276 | |
08e0e7c8 DH |
277 | _debug("Vids: %08x %08x %08x", |
278 | vldb->vid[0], vldb->vid[1], vldb->vid[2]); | |
1da177e4 | 279 | |
08e0e7c8 DH |
280 | if (strcmp(vldb->name, vl->vldb.name) != 0) |
281 | printk(KERN_NOTICE "kAFS:" | |
282 | " name of volume '%s' changed to '%s' on server\n", | |
283 | vl->vldb.name, vldb->name); | |
1da177e4 | 284 | |
08e0e7c8 | 285 | vl->vldb = *vldb; |
1da177e4 | 286 | |
9b3f26c9 DH |
287 | #ifdef CONFIG_AFS_FSCACHE |
288 | fscache_update_cookie(vl->cache); | |
1da177e4 | 289 | #endif |
ec26815a | 290 | } |
1da177e4 | 291 | |
1da177e4 | 292 | /* |
08e0e7c8 DH |
293 | * fill in a volume location record, consulting the cache and the VL server |
294 | * both | |
1da177e4 | 295 | */ |
00d3b7a4 DH |
296 | static int afs_vlocation_fill_in_record(struct afs_vlocation *vl, |
297 | struct key *key) | |
1da177e4 | 298 | { |
08e0e7c8 DH |
299 | struct afs_cache_vlocation vldb; |
300 | int ret; | |
1da177e4 | 301 | |
08e0e7c8 | 302 | _enter(""); |
1da177e4 | 303 | |
08e0e7c8 | 304 | ASSERTCMP(vl->valid, ==, 0); |
1da177e4 | 305 | |
08e0e7c8 | 306 | memset(&vldb, 0, sizeof(vldb)); |
1da177e4 | 307 | |
08e0e7c8 | 308 | /* see if we have an in-cache copy (will set vl->valid if there is) */ |
9b3f26c9 DH |
309 | #ifdef CONFIG_AFS_FSCACHE |
310 | vl->cache = fscache_acquire_cookie(vl->cell->cache, | |
94d30ae9 DH |
311 | &afs_vlocation_cache_index_def, vl, |
312 | true); | |
08e0e7c8 | 313 | #endif |
1da177e4 | 314 | |
08e0e7c8 DH |
315 | if (vl->valid) { |
316 | /* try to update a known volume in the cell VL databases by | |
317 | * ID as the name may have changed */ | |
318 | _debug("found in cache"); | |
00d3b7a4 | 319 | ret = afs_vlocation_update_record(vl, key, &vldb); |
08e0e7c8 DH |
320 | } else { |
321 | /* try to look up an unknown volume in the cell VL databases by | |
322 | * name */ | |
00d3b7a4 | 323 | ret = afs_vlocation_access_vl_by_name(vl, key, &vldb); |
08e0e7c8 DH |
324 | if (ret < 0) { |
325 | printk("kAFS: failed to locate '%s' in cell '%s'\n", | |
326 | vl->vldb.name, vl->cell->name); | |
327 | return ret; | |
328 | } | |
1da177e4 LT |
329 | } |
330 | ||
08e0e7c8 DH |
331 | afs_vlocation_apply_update(vl, &vldb); |
332 | _leave(" = 0"); | |
333 | return 0; | |
ec26815a | 334 | } |
1da177e4 | 335 | |
1da177e4 | 336 | /* |
08e0e7c8 | 337 | * queue a vlocation record for updates |
1da177e4 | 338 | */ |
c1206a2c | 339 | static void afs_vlocation_queue_for_updates(struct afs_vlocation *vl) |
1da177e4 | 340 | { |
08e0e7c8 | 341 | struct afs_vlocation *xvl; |
1da177e4 | 342 | |
08e0e7c8 DH |
343 | /* wait at least 10 minutes before updating... */ |
344 | vl->update_at = get_seconds() + afs_vlocation_update_timeout; | |
345 | ||
346 | spin_lock(&afs_vlocation_updates_lock); | |
347 | ||
348 | if (!list_empty(&afs_vlocation_updates)) { | |
349 | /* ... but wait at least 1 second more than the newest record | |
350 | * already queued so that we don't spam the VL server suddenly | |
351 | * with lots of requests | |
352 | */ | |
353 | xvl = list_entry(afs_vlocation_updates.prev, | |
354 | struct afs_vlocation, update); | |
355 | if (vl->update_at <= xvl->update_at) | |
356 | vl->update_at = xvl->update_at + 1; | |
357 | } else { | |
358 | queue_delayed_work(afs_vlocation_update_worker, | |
359 | &afs_vlocation_update, | |
360 | afs_vlocation_update_timeout * HZ); | |
1da177e4 | 361 | } |
08e0e7c8 DH |
362 | |
363 | list_add_tail(&vl->update, &afs_vlocation_updates); | |
364 | spin_unlock(&afs_vlocation_updates_lock); | |
ec26815a | 365 | } |
1da177e4 | 366 | |
1da177e4 | 367 | /* |
08e0e7c8 DH |
368 | * lookup volume location |
369 | * - iterate through the VL servers in a cell until one of them admits knowing | |
370 | * about the volume in question | |
371 | * - lookup in the local cache if not able to find on the VL server | |
372 | * - insert/update in the local cache if did get a VL response | |
1da177e4 | 373 | */ |
08e0e7c8 | 374 | struct afs_vlocation *afs_vlocation_lookup(struct afs_cell *cell, |
00d3b7a4 | 375 | struct key *key, |
08e0e7c8 DH |
376 | const char *name, |
377 | size_t namesz) | |
1da177e4 | 378 | { |
08e0e7c8 DH |
379 | struct afs_vlocation *vl; |
380 | int ret; | |
1da177e4 | 381 | |
00d3b7a4 DH |
382 | _enter("{%s},{%x},%*.*s,%zu", |
383 | cell->name, key_serial(key), | |
384 | (int) namesz, (int) namesz, name, namesz); | |
1da177e4 | 385 | |
6551198a | 386 | if (namesz >= sizeof(vl->vldb.name)) { |
08e0e7c8 DH |
387 | _leave(" = -ENAMETOOLONG"); |
388 | return ERR_PTR(-ENAMETOOLONG); | |
389 | } | |
1da177e4 | 390 | |
08e0e7c8 DH |
391 | /* see if we have an in-memory copy first */ |
392 | down_write(&cell->vl_sem); | |
393 | spin_lock(&cell->vl_lock); | |
394 | list_for_each_entry(vl, &cell->vl_list, link) { | |
395 | if (vl->vldb.name[namesz] != '\0') | |
396 | continue; | |
397 | if (memcmp(vl->vldb.name, name, namesz) == 0) | |
398 | goto found_in_memory; | |
1da177e4 | 399 | } |
08e0e7c8 | 400 | spin_unlock(&cell->vl_lock); |
1da177e4 | 401 | |
08e0e7c8 DH |
402 | /* not in the cell's in-memory lists - create a new record */ |
403 | vl = afs_vlocation_alloc(cell, name, namesz); | |
404 | if (!vl) { | |
405 | up_write(&cell->vl_sem); | |
406 | return ERR_PTR(-ENOMEM); | |
407 | } | |
1da177e4 | 408 | |
08e0e7c8 | 409 | afs_get_cell(cell); |
1da177e4 | 410 | |
08e0e7c8 DH |
411 | list_add_tail(&vl->link, &cell->vl_list); |
412 | vl->state = AFS_VL_CREATING; | |
413 | up_write(&cell->vl_sem); | |
1da177e4 | 414 | |
08e0e7c8 | 415 | fill_in_record: |
00d3b7a4 | 416 | ret = afs_vlocation_fill_in_record(vl, key); |
08e0e7c8 DH |
417 | if (ret < 0) |
418 | goto error_abandon; | |
39bf0949 | 419 | spin_lock(&vl->lock); |
08e0e7c8 | 420 | vl->state = AFS_VL_VALID; |
39bf0949 | 421 | spin_unlock(&vl->lock); |
47051a21 | 422 | wake_up(&vl->waitq); |
1da177e4 | 423 | |
9b3f26c9 DH |
424 | /* update volume entry in local cache */ |
425 | #ifdef CONFIG_AFS_FSCACHE | |
426 | fscache_update_cookie(vl->cache); | |
427 | #endif | |
428 | ||
08e0e7c8 DH |
429 | /* schedule for regular updates */ |
430 | afs_vlocation_queue_for_updates(vl); | |
431 | goto success; | |
1da177e4 | 432 | |
08e0e7c8 DH |
433 | found_in_memory: |
434 | /* found in memory */ | |
435 | _debug("found in memory"); | |
436 | atomic_inc(&vl->usage); | |
437 | spin_unlock(&cell->vl_lock); | |
438 | if (!list_empty(&vl->grave)) { | |
439 | spin_lock(&afs_vlocation_graveyard_lock); | |
440 | list_del_init(&vl->grave); | |
441 | spin_unlock(&afs_vlocation_graveyard_lock); | |
1da177e4 | 442 | } |
08e0e7c8 | 443 | up_write(&cell->vl_sem); |
1da177e4 | 444 | |
08e0e7c8 | 445 | /* see if it was an abandoned record that we might try filling in */ |
39bf0949 | 446 | spin_lock(&vl->lock); |
08e0e7c8 DH |
447 | while (vl->state != AFS_VL_VALID) { |
448 | afs_vlocation_state_t state = vl->state; | |
1da177e4 | 449 | |
08e0e7c8 | 450 | _debug("invalid [state %d]", state); |
1da177e4 | 451 | |
47051a21 | 452 | if (state == AFS_VL_NEW || state == AFS_VL_NO_VOLUME) { |
39bf0949 DM |
453 | vl->state = AFS_VL_CREATING; |
454 | spin_unlock(&vl->lock); | |
455 | goto fill_in_record; | |
08e0e7c8 DH |
456 | } |
457 | ||
458 | /* must now wait for creation or update by someone else to | |
459 | * complete */ | |
460 | _debug("wait"); | |
461 | ||
39bf0949 | 462 | spin_unlock(&vl->lock); |
47051a21 DH |
463 | ret = wait_event_interruptible(vl->waitq, |
464 | vl->state == AFS_VL_NEW || | |
465 | vl->state == AFS_VL_VALID || | |
466 | vl->state == AFS_VL_NO_VOLUME); | |
08e0e7c8 DH |
467 | if (ret < 0) |
468 | goto error; | |
39bf0949 | 469 | spin_lock(&vl->lock); |
1da177e4 | 470 | } |
39bf0949 | 471 | spin_unlock(&vl->lock); |
1da177e4 | 472 | |
08e0e7c8 | 473 | success: |
9b3f26c9 | 474 | _leave(" = %p", vl); |
08e0e7c8 DH |
475 | return vl; |
476 | ||
477 | error_abandon: | |
39bf0949 | 478 | spin_lock(&vl->lock); |
08e0e7c8 | 479 | vl->state = AFS_VL_NEW; |
39bf0949 | 480 | spin_unlock(&vl->lock); |
47051a21 | 481 | wake_up(&vl->waitq); |
08e0e7c8 DH |
482 | error: |
483 | ASSERT(vl != NULL); | |
484 | afs_put_vlocation(vl); | |
1da177e4 | 485 | _leave(" = %d", ret); |
08e0e7c8 | 486 | return ERR_PTR(ret); |
ec26815a | 487 | } |
1da177e4 | 488 | |
1da177e4 | 489 | /* |
08e0e7c8 | 490 | * finish using a volume location record |
1da177e4 | 491 | */ |
08e0e7c8 | 492 | void afs_put_vlocation(struct afs_vlocation *vl) |
1da177e4 | 493 | { |
08e0e7c8 DH |
494 | if (!vl) |
495 | return; | |
1da177e4 | 496 | |
08e0e7c8 | 497 | _enter("%s", vl->vldb.name); |
1da177e4 | 498 | |
08e0e7c8 | 499 | ASSERTCMP(atomic_read(&vl->usage), >, 0); |
1da177e4 | 500 | |
08e0e7c8 DH |
501 | if (likely(!atomic_dec_and_test(&vl->usage))) { |
502 | _leave(""); | |
503 | return; | |
504 | } | |
1da177e4 | 505 | |
08e0e7c8 DH |
506 | spin_lock(&afs_vlocation_graveyard_lock); |
507 | if (atomic_read(&vl->usage) == 0) { | |
508 | _debug("buried"); | |
509 | list_move_tail(&vl->grave, &afs_vlocation_graveyard); | |
510 | vl->time_of_death = get_seconds(); | |
0ad53eee TH |
511 | queue_delayed_work(afs_wq, &afs_vlocation_reap, |
512 | afs_vlocation_timeout * HZ); | |
08e0e7c8 DH |
513 | |
514 | /* suspend updates on this record */ | |
515 | if (!list_empty(&vl->update)) { | |
516 | spin_lock(&afs_vlocation_updates_lock); | |
517 | list_del_init(&vl->update); | |
518 | spin_unlock(&afs_vlocation_updates_lock); | |
519 | } | |
520 | } | |
521 | spin_unlock(&afs_vlocation_graveyard_lock); | |
522 | _leave(" [killed?]"); | |
ec26815a | 523 | } |
1da177e4 | 524 | |
1da177e4 | 525 | /* |
08e0e7c8 | 526 | * destroy a dead volume location record |
1da177e4 | 527 | */ |
08e0e7c8 | 528 | static void afs_vlocation_destroy(struct afs_vlocation *vl) |
1da177e4 | 529 | { |
08e0e7c8 | 530 | _enter("%p", vl); |
1da177e4 | 531 | |
9b3f26c9 DH |
532 | #ifdef CONFIG_AFS_FSCACHE |
533 | fscache_relinquish_cookie(vl->cache, 0); | |
08e0e7c8 | 534 | #endif |
08e0e7c8 DH |
535 | afs_put_cell(vl->cell); |
536 | kfree(vl); | |
537 | } | |
538 | ||
539 | /* | |
540 | * reap dead volume location records | |
541 | */ | |
542 | static void afs_vlocation_reaper(struct work_struct *work) | |
543 | { | |
544 | LIST_HEAD(corpses); | |
545 | struct afs_vlocation *vl; | |
546 | unsigned long delay, expiry; | |
547 | time_t now; | |
1da177e4 | 548 | |
08e0e7c8 | 549 | _enter(""); |
1da177e4 | 550 | |
08e0e7c8 DH |
551 | now = get_seconds(); |
552 | spin_lock(&afs_vlocation_graveyard_lock); | |
553 | ||
554 | while (!list_empty(&afs_vlocation_graveyard)) { | |
555 | vl = list_entry(afs_vlocation_graveyard.next, | |
556 | struct afs_vlocation, grave); | |
557 | ||
558 | _debug("check %p", vl); | |
559 | ||
560 | /* the queue is ordered most dead first */ | |
561 | expiry = vl->time_of_death + afs_vlocation_timeout; | |
562 | if (expiry > now) { | |
563 | delay = (expiry - now) * HZ; | |
564 | _debug("delay %lu", delay); | |
41f63c53 | 565 | mod_delayed_work(afs_wq, &afs_vlocation_reap, delay); |
08e0e7c8 DH |
566 | break; |
567 | } | |
1da177e4 | 568 | |
08e0e7c8 DH |
569 | spin_lock(&vl->cell->vl_lock); |
570 | if (atomic_read(&vl->usage) > 0) { | |
571 | _debug("no reap"); | |
572 | list_del_init(&vl->grave); | |
ec26815a | 573 | } else { |
08e0e7c8 DH |
574 | _debug("reap"); |
575 | list_move_tail(&vl->grave, &corpses); | |
576 | list_del_init(&vl->link); | |
1da177e4 | 577 | } |
08e0e7c8 | 578 | spin_unlock(&vl->cell->vl_lock); |
1da177e4 LT |
579 | } |
580 | ||
08e0e7c8 | 581 | spin_unlock(&afs_vlocation_graveyard_lock); |
1da177e4 | 582 | |
08e0e7c8 DH |
583 | /* now reap the corpses we've extracted */ |
584 | while (!list_empty(&corpses)) { | |
585 | vl = list_entry(corpses.next, struct afs_vlocation, grave); | |
586 | list_del(&vl->grave); | |
587 | afs_vlocation_destroy(vl); | |
1da177e4 LT |
588 | } |
589 | ||
590 | _leave(""); | |
08e0e7c8 | 591 | } |
1da177e4 | 592 | |
08e0e7c8 DH |
593 | /* |
594 | * initialise the VL update process | |
595 | */ | |
596 | int __init afs_vlocation_update_init(void) | |
597 | { | |
598 | afs_vlocation_update_worker = | |
599 | create_singlethread_workqueue("kafs_vlupdated"); | |
600 | return afs_vlocation_update_worker ? 0 : -ENOMEM; | |
601 | } | |
602 | ||
603 | /* | |
604 | * discard all the volume location records for rmmod | |
605 | */ | |
fbb3fcba | 606 | void afs_vlocation_purge(void) |
08e0e7c8 DH |
607 | { |
608 | afs_vlocation_timeout = 0; | |
609 | ||
610 | spin_lock(&afs_vlocation_updates_lock); | |
611 | list_del_init(&afs_vlocation_updates); | |
612 | spin_unlock(&afs_vlocation_updates_lock); | |
41f63c53 | 613 | mod_delayed_work(afs_vlocation_update_worker, &afs_vlocation_update, 0); |
08e0e7c8 DH |
614 | destroy_workqueue(afs_vlocation_update_worker); |
615 | ||
41f63c53 | 616 | mod_delayed_work(afs_wq, &afs_vlocation_reap, 0); |
ec26815a | 617 | } |
1da177e4 | 618 | |
1da177e4 | 619 | /* |
08e0e7c8 | 620 | * update a volume location |
1da177e4 | 621 | */ |
08e0e7c8 | 622 | static void afs_vlocation_updater(struct work_struct *work) |
1da177e4 LT |
623 | { |
624 | struct afs_cache_vlocation vldb; | |
08e0e7c8 DH |
625 | struct afs_vlocation *vl, *xvl; |
626 | time_t now; | |
627 | long timeout; | |
1da177e4 LT |
628 | int ret; |
629 | ||
08e0e7c8 | 630 | _enter(""); |
1da177e4 | 631 | |
08e0e7c8 | 632 | now = get_seconds(); |
1da177e4 | 633 | |
08e0e7c8 DH |
634 | /* find a record to update */ |
635 | spin_lock(&afs_vlocation_updates_lock); | |
636 | for (;;) { | |
637 | if (list_empty(&afs_vlocation_updates)) { | |
638 | spin_unlock(&afs_vlocation_updates_lock); | |
639 | _leave(" [nothing]"); | |
640 | return; | |
641 | } | |
1da177e4 | 642 | |
08e0e7c8 DH |
643 | vl = list_entry(afs_vlocation_updates.next, |
644 | struct afs_vlocation, update); | |
645 | if (atomic_read(&vl->usage) > 0) | |
646 | break; | |
647 | list_del_init(&vl->update); | |
1da177e4 LT |
648 | } |
649 | ||
08e0e7c8 DH |
650 | timeout = vl->update_at - now; |
651 | if (timeout > 0) { | |
652 | queue_delayed_work(afs_vlocation_update_worker, | |
653 | &afs_vlocation_update, timeout * HZ); | |
654 | spin_unlock(&afs_vlocation_updates_lock); | |
655 | _leave(" [nothing]"); | |
1da177e4 LT |
656 | return; |
657 | } | |
658 | ||
08e0e7c8 DH |
659 | list_del_init(&vl->update); |
660 | atomic_inc(&vl->usage); | |
661 | spin_unlock(&afs_vlocation_updates_lock); | |
1da177e4 | 662 | |
08e0e7c8 DH |
663 | /* we can now perform the update */ |
664 | _debug("update %s", vl->vldb.name); | |
665 | vl->state = AFS_VL_UPDATING; | |
666 | vl->upd_rej_cnt = 0; | |
667 | vl->upd_busy_cnt = 0; | |
1da177e4 | 668 | |
00d3b7a4 | 669 | ret = afs_vlocation_update_record(vl, NULL, &vldb); |
39bf0949 | 670 | spin_lock(&vl->lock); |
08e0e7c8 DH |
671 | switch (ret) { |
672 | case 0: | |
673 | afs_vlocation_apply_update(vl, &vldb); | |
674 | vl->state = AFS_VL_VALID; | |
675 | break; | |
676 | case -ENOMEDIUM: | |
677 | vl->state = AFS_VL_VOLUME_DELETED; | |
678 | break; | |
679 | default: | |
680 | vl->state = AFS_VL_UNCERTAIN; | |
681 | break; | |
682 | } | |
39bf0949 | 683 | spin_unlock(&vl->lock); |
47051a21 | 684 | wake_up(&vl->waitq); |
1da177e4 | 685 | |
08e0e7c8 DH |
686 | /* and then reschedule */ |
687 | _debug("reschedule"); | |
688 | vl->update_at = get_seconds() + afs_vlocation_update_timeout; | |
1da177e4 | 689 | |
08e0e7c8 | 690 | spin_lock(&afs_vlocation_updates_lock); |
1da177e4 | 691 | |
08e0e7c8 DH |
692 | if (!list_empty(&afs_vlocation_updates)) { |
693 | /* next update in 10 minutes, but wait at least 1 second more | |
694 | * than the newest record already queued so that we don't spam | |
695 | * the VL server suddenly with lots of requests | |
696 | */ | |
697 | xvl = list_entry(afs_vlocation_updates.prev, | |
698 | struct afs_vlocation, update); | |
699 | if (vl->update_at <= xvl->update_at) | |
700 | vl->update_at = xvl->update_at + 1; | |
701 | xvl = list_entry(afs_vlocation_updates.next, | |
702 | struct afs_vlocation, update); | |
703 | timeout = xvl->update_at - now; | |
704 | if (timeout < 0) | |
705 | timeout = 0; | |
706 | } else { | |
707 | timeout = afs_vlocation_update_timeout; | |
1da177e4 LT |
708 | } |
709 | ||
08e0e7c8 | 710 | ASSERT(list_empty(&vl->update)); |
1da177e4 | 711 | |
08e0e7c8 | 712 | list_add_tail(&vl->update, &afs_vlocation_updates); |
1da177e4 | 713 | |
08e0e7c8 DH |
714 | _debug("timeout %ld", timeout); |
715 | queue_delayed_work(afs_vlocation_update_worker, | |
716 | &afs_vlocation_update, timeout * HZ); | |
717 | spin_unlock(&afs_vlocation_updates_lock); | |
718 | afs_put_vlocation(vl); | |
ec26815a | 719 | } |