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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
ec26815a | 2 | /* AFS volume management |
1da177e4 | 3 | * |
08e0e7c8 | 4 | * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved. |
1da177e4 | 5 | * Written by David Howells (dhowells@redhat.com) |
1da177e4 LT |
6 | */ |
7 | ||
8 | #include <linux/kernel.h> | |
1da177e4 | 9 | #include <linux/slab.h> |
1da177e4 LT |
10 | #include "internal.h" |
11 | ||
d2ddc776 DH |
12 | unsigned __read_mostly afs_volume_gc_delay = 10; |
13 | unsigned __read_mostly afs_volume_record_life = 60 * 60; | |
14 | ||
20325960 DH |
15 | /* |
16 | * Insert a volume into a cell. If there's an existing volume record, that is | |
17 | * returned instead with a ref held. | |
18 | */ | |
19 | static struct afs_volume *afs_insert_volume_into_cell(struct afs_cell *cell, | |
20 | struct afs_volume *volume) | |
21 | { | |
22 | struct afs_volume *p; | |
23 | struct rb_node *parent = NULL, **pp; | |
24 | ||
25 | write_seqlock(&cell->volume_lock); | |
26 | ||
27 | pp = &cell->volumes.rb_node; | |
28 | while (*pp) { | |
29 | parent = *pp; | |
30 | p = rb_entry(parent, struct afs_volume, cell_node); | |
31 | if (p->vid < volume->vid) { | |
32 | pp = &(*pp)->rb_left; | |
33 | } else if (p->vid > volume->vid) { | |
34 | pp = &(*pp)->rb_right; | |
35 | } else { | |
36 | volume = afs_get_volume(p, afs_volume_trace_get_cell_insert); | |
37 | goto found; | |
38 | } | |
39 | } | |
40 | ||
41 | rb_link_node_rcu(&volume->cell_node, parent, pp); | |
42 | rb_insert_color(&volume->cell_node, &cell->volumes); | |
43 | hlist_add_head_rcu(&volume->proc_link, &cell->proc_volumes); | |
44 | ||
45 | found: | |
46 | write_sequnlock(&cell->volume_lock); | |
47 | return volume; | |
48 | ||
49 | } | |
50 | ||
51 | static void afs_remove_volume_from_cell(struct afs_volume *volume) | |
52 | { | |
53 | struct afs_cell *cell = volume->cell; | |
54 | ||
55 | if (!hlist_unhashed(&volume->proc_link)) { | |
56 | trace_afs_volume(volume->vid, atomic_read(&volume->usage), | |
57 | afs_volume_trace_remove); | |
58 | write_seqlock(&cell->volume_lock); | |
59 | hlist_del_rcu(&volume->proc_link); | |
60 | rb_erase(&volume->cell_node, &cell->volumes); | |
61 | write_sequnlock(&cell->volume_lock); | |
62 | } | |
63 | } | |
64 | ||
1da177e4 | 65 | /* |
d2ddc776 DH |
66 | * Allocate a volume record and load it up from a vldb record. |
67 | */ | |
13fcc683 | 68 | static struct afs_volume *afs_alloc_volume(struct afs_fs_context *params, |
d2ddc776 DH |
69 | struct afs_vldb_entry *vldb, |
70 | unsigned long type_mask) | |
71 | { | |
72 | struct afs_server_list *slist; | |
d2ddc776 | 73 | struct afs_volume *volume; |
45df8462 | 74 | int ret = -ENOMEM, nr_servers = 0, i; |
d2ddc776 DH |
75 | |
76 | for (i = 0; i < vldb->nr_servers; i++) | |
77 | if (vldb->fs_mask[i] & type_mask) | |
78 | nr_servers++; | |
79 | ||
80 | volume = kzalloc(sizeof(struct afs_volume), GFP_KERNEL); | |
81 | if (!volume) | |
82 | goto error_0; | |
83 | ||
84 | volume->vid = vldb->vid[params->type]; | |
85 | volume->update_at = ktime_get_real_seconds() + afs_volume_record_life; | |
dca54a7b | 86 | volume->cell = afs_get_cell(params->cell, afs_cell_trace_get_vol); |
d2ddc776 DH |
87 | volume->type = params->type; |
88 | volume->type_force = params->force; | |
89 | volume->name_len = vldb->name_len; | |
90 | ||
91 | atomic_set(&volume->usage, 1); | |
20325960 | 92 | INIT_HLIST_NODE(&volume->proc_link); |
d2ddc776 | 93 | rwlock_init(&volume->servers_lock); |
90fa9b64 | 94 | rwlock_init(&volume->cb_v_break_lock); |
d2ddc776 DH |
95 | memcpy(volume->name, vldb->name, vldb->name_len + 1); |
96 | ||
97 | slist = afs_alloc_server_list(params->cell, params->key, vldb, type_mask); | |
98 | if (IS_ERR(slist)) { | |
99 | ret = PTR_ERR(slist); | |
100 | goto error_1; | |
101 | } | |
102 | ||
103 | refcount_set(&slist->usage, 1); | |
8a070a96 | 104 | rcu_assign_pointer(volume->servers, slist); |
cca37d45 | 105 | trace_afs_volume(volume->vid, 1, afs_volume_trace_alloc); |
d2ddc776 DH |
106 | return volume; |
107 | ||
d2ddc776 | 108 | error_1: |
dca54a7b | 109 | afs_put_cell(volume->cell, afs_cell_trace_put_vol); |
d2ddc776 DH |
110 | kfree(volume); |
111 | error_0: | |
112 | return ERR_PTR(ret); | |
113 | } | |
114 | ||
20325960 DH |
115 | /* |
116 | * Look up or allocate a volume record. | |
117 | */ | |
118 | static struct afs_volume *afs_lookup_volume(struct afs_fs_context *params, | |
119 | struct afs_vldb_entry *vldb, | |
120 | unsigned long type_mask) | |
121 | { | |
122 | struct afs_volume *candidate, *volume; | |
123 | ||
124 | candidate = afs_alloc_volume(params, vldb, type_mask); | |
125 | if (IS_ERR(candidate)) | |
126 | return candidate; | |
127 | ||
128 | volume = afs_insert_volume_into_cell(params->cell, candidate); | |
129 | if (volume != candidate) | |
130 | afs_put_volume(params->net, candidate, afs_volume_trace_put_cell_dup); | |
131 | return volume; | |
132 | } | |
133 | ||
d2ddc776 DH |
134 | /* |
135 | * Look up a VLDB record for a volume. | |
136 | */ | |
137 | static struct afs_vldb_entry *afs_vl_lookup_vldb(struct afs_cell *cell, | |
138 | struct key *key, | |
139 | const char *volname, | |
140 | size_t volnamesz) | |
141 | { | |
0a5143f2 DH |
142 | struct afs_vldb_entry *vldb = ERR_PTR(-EDESTADDRREQ); |
143 | struct afs_vl_cursor vc; | |
d2ddc776 DH |
144 | int ret; |
145 | ||
0a5143f2 DH |
146 | if (!afs_begin_vlserver_operation(&vc, cell, key)) |
147 | return ERR_PTR(-ERESTARTSYS); | |
d2ddc776 | 148 | |
0a5143f2 | 149 | while (afs_select_vlserver(&vc)) { |
0a5143f2 | 150 | vldb = afs_vl_get_entry_by_name_u(&vc, volname, volnamesz); |
d2ddc776 DH |
151 | } |
152 | ||
0a5143f2 DH |
153 | ret = afs_end_vlserver_operation(&vc); |
154 | return ret < 0 ? ERR_PTR(ret) : vldb; | |
d2ddc776 DH |
155 | } |
156 | ||
157 | /* | |
158 | * Look up a volume in the VL server and create a candidate volume record for | |
159 | * it. | |
160 | * | |
161 | * The volume name can be one of the following: | |
1da177e4 LT |
162 | * "%[cell:]volume[.]" R/W volume |
163 | * "#[cell:]volume[.]" R/O or R/W volume (rwparent=0), | |
164 | * or R/W (rwparent=1) volume | |
165 | * "%[cell:]volume.readonly" R/O volume | |
166 | * "#[cell:]volume.readonly" R/O volume | |
167 | * "%[cell:]volume.backup" Backup volume | |
168 | * "#[cell:]volume.backup" Backup volume | |
169 | * | |
170 | * The cell name is optional, and defaults to the current cell. | |
171 | * | |
172 | * See "The Rules of Mount Point Traversal" in Chapter 5 of the AFS SysAdmin | |
173 | * Guide | |
174 | * - Rule 1: Explicit type suffix forces access of that type or nothing | |
175 | * (no suffix, then use Rule 2 & 3) | |
176 | * - Rule 2: If parent volume is R/O, then mount R/O volume by preference, R/W | |
177 | * if not available | |
178 | * - Rule 3: If parent volume is R/W, then only mount R/W volume unless | |
179 | * explicitly told otherwise | |
180 | */ | |
13fcc683 | 181 | struct afs_volume *afs_create_volume(struct afs_fs_context *params) |
1da177e4 | 182 | { |
d2ddc776 DH |
183 | struct afs_vldb_entry *vldb; |
184 | struct afs_volume *volume; | |
185 | unsigned long type_mask = 1UL << params->type; | |
1da177e4 | 186 | |
d2ddc776 DH |
187 | vldb = afs_vl_lookup_vldb(params->cell, params->key, |
188 | params->volname, params->volnamesz); | |
189 | if (IS_ERR(vldb)) | |
190 | return ERR_CAST(vldb); | |
1da177e4 | 191 | |
d2ddc776 DH |
192 | if (test_bit(AFS_VLDB_QUERY_ERROR, &vldb->flags)) { |
193 | volume = ERR_PTR(vldb->error); | |
194 | goto error; | |
195 | } | |
1da177e4 | 196 | |
d2ddc776 DH |
197 | /* Make the final decision on the type we want */ |
198 | volume = ERR_PTR(-ENOMEDIUM); | |
00d3b7a4 | 199 | if (params->force) { |
d2ddc776 | 200 | if (!(vldb->flags & type_mask)) |
1da177e4 | 201 | goto error; |
d2ddc776 | 202 | } else if (test_bit(AFS_VLDB_HAS_RO, &vldb->flags)) { |
00d3b7a4 | 203 | params->type = AFSVL_ROVOL; |
d2ddc776 | 204 | } else if (test_bit(AFS_VLDB_HAS_RW, &vldb->flags)) { |
00d3b7a4 | 205 | params->type = AFSVL_RWVOL; |
ec26815a | 206 | } else { |
1da177e4 LT |
207 | goto error; |
208 | } | |
209 | ||
d2ddc776 | 210 | type_mask = 1UL << params->type; |
20325960 | 211 | volume = afs_lookup_volume(params, vldb, type_mask); |
1da177e4 | 212 | |
d2ddc776 DH |
213 | error: |
214 | kfree(vldb); | |
215 | return volume; | |
216 | } | |
1da177e4 | 217 | |
d2ddc776 DH |
218 | /* |
219 | * Destroy a volume record | |
220 | */ | |
221 | static void afs_destroy_volume(struct afs_net *net, struct afs_volume *volume) | |
222 | { | |
223 | _enter("%p", volume); | |
1da177e4 | 224 | |
d2ddc776 DH |
225 | #ifdef CONFIG_AFS_FSCACHE |
226 | ASSERTCMP(volume->cache, ==, NULL); | |
227 | #endif | |
1da177e4 | 228 | |
20325960 | 229 | afs_remove_volume_from_cell(volume); |
8a070a96 | 230 | afs_put_serverlist(net, rcu_access_pointer(volume->servers)); |
dca54a7b | 231 | afs_put_cell(volume->cell, afs_cell_trace_put_vol); |
cca37d45 DH |
232 | trace_afs_volume(volume->vid, atomic_read(&volume->usage), |
233 | afs_volume_trace_free); | |
20325960 | 234 | kfree_rcu(volume, rcu); |
1da177e4 | 235 | |
d2ddc776 DH |
236 | _leave(" [destroyed]"); |
237 | } | |
238 | ||
239 | /* | |
cca37d45 | 240 | * Get a reference on a volume record. |
d2ddc776 | 241 | */ |
cca37d45 DH |
242 | struct afs_volume *afs_get_volume(struct afs_volume *volume, |
243 | enum afs_volume_trace reason) | |
d2ddc776 DH |
244 | { |
245 | if (volume) { | |
cca37d45 DH |
246 | int u = atomic_inc_return(&volume->usage); |
247 | trace_afs_volume(volume->vid, u, reason); | |
248 | } | |
249 | return volume; | |
250 | } | |
251 | ||
d2ddc776 | 252 | |
cca37d45 DH |
253 | /* |
254 | * Drop a reference on a volume record. | |
255 | */ | |
256 | void afs_put_volume(struct afs_net *net, struct afs_volume *volume, | |
257 | enum afs_volume_trace reason) | |
258 | { | |
259 | if (volume) { | |
260 | afs_volid_t vid = volume->vid; | |
261 | int u = atomic_dec_return(&volume->usage); | |
262 | trace_afs_volume(vid, u, reason); | |
263 | if (u == 0) | |
e49c7b2f | 264 | afs_destroy_volume(net, volume); |
1da177e4 | 265 | } |
d2ddc776 | 266 | } |
1da177e4 | 267 | |
d2ddc776 DH |
268 | /* |
269 | * Activate a volume. | |
270 | */ | |
271 | void afs_activate_volume(struct afs_volume *volume) | |
272 | { | |
9b3f26c9 | 273 | #ifdef CONFIG_AFS_FSCACHE |
ad6a942a | 274 | volume->cache = fscache_acquire_cookie(volume->cell->cache, |
9b3f26c9 | 275 | &afs_volume_cache_index_def, |
402cb8dd DH |
276 | &volume->vid, sizeof(volume->vid), |
277 | NULL, 0, | |
ee1235a9 | 278 | volume, 0, true); |
1da177e4 | 279 | #endif |
d2ddc776 | 280 | } |
1da177e4 | 281 | |
d2ddc776 DH |
282 | /* |
283 | * Deactivate a volume. | |
284 | */ | |
285 | void afs_deactivate_volume(struct afs_volume *volume) | |
286 | { | |
287 | _enter("%s", volume->name); | |
1da177e4 | 288 | |
d2ddc776 | 289 | #ifdef CONFIG_AFS_FSCACHE |
402cb8dd | 290 | fscache_relinquish_cookie(volume->cache, NULL, |
d2ddc776 DH |
291 | test_bit(AFS_VOLUME_DELETED, &volume->flags)); |
292 | volume->cache = NULL; | |
293 | #endif | |
1da177e4 | 294 | |
d2ddc776 | 295 | _leave(""); |
ec26815a | 296 | } |
1da177e4 | 297 | |
1da177e4 | 298 | /* |
d2ddc776 | 299 | * Query the VL service to update the volume status. |
1da177e4 | 300 | */ |
d2ddc776 | 301 | static int afs_update_volume_status(struct afs_volume *volume, struct key *key) |
1da177e4 | 302 | { |
d2ddc776 DH |
303 | struct afs_server_list *new, *old, *discard; |
304 | struct afs_vldb_entry *vldb; | |
305 | char idbuf[16]; | |
306 | int ret, idsz; | |
1da177e4 | 307 | |
d2ddc776 | 308 | _enter(""); |
1da177e4 | 309 | |
d2ddc776 DH |
310 | /* We look up an ID by passing it as a decimal string in the |
311 | * operation's name parameter. | |
312 | */ | |
3b6492df | 313 | idsz = sprintf(idbuf, "%llu", volume->vid); |
1da177e4 | 314 | |
d2ddc776 DH |
315 | vldb = afs_vl_lookup_vldb(volume->cell, key, idbuf, idsz); |
316 | if (IS_ERR(vldb)) { | |
317 | ret = PTR_ERR(vldb); | |
318 | goto error; | |
319 | } | |
1da177e4 | 320 | |
d2ddc776 DH |
321 | /* See if the volume got renamed. */ |
322 | if (vldb->name_len != volume->name_len || | |
323 | memcmp(vldb->name, volume->name, vldb->name_len) != 0) { | |
324 | /* TODO: Use RCU'd string. */ | |
325 | memcpy(volume->name, vldb->name, AFS_MAXVOLNAME); | |
326 | volume->name_len = vldb->name_len; | |
327 | } | |
328 | ||
329 | /* See if the volume's server list got updated. */ | |
330 | new = afs_alloc_server_list(volume->cell, key, | |
45df8462 | 331 | vldb, (1 << volume->type)); |
d2ddc776 DH |
332 | if (IS_ERR(new)) { |
333 | ret = PTR_ERR(new); | |
334 | goto error_vldb; | |
335 | } | |
1da177e4 | 336 | |
d2ddc776 | 337 | write_lock(&volume->servers_lock); |
1da177e4 | 338 | |
d2ddc776 | 339 | discard = new; |
8a070a96 DH |
340 | old = rcu_dereference_protected(volume->servers, |
341 | lockdep_is_held(&volume->servers_lock)); | |
d2ddc776 DH |
342 | if (afs_annotate_server_list(new, old)) { |
343 | new->seq = volume->servers_seq + 1; | |
8a070a96 | 344 | rcu_assign_pointer(volume->servers, new); |
d2ddc776 DH |
345 | smp_wmb(); |
346 | volume->servers_seq++; | |
347 | discard = old; | |
1da177e4 LT |
348 | } |
349 | ||
d2ddc776 | 350 | volume->update_at = ktime_get_real_seconds() + afs_volume_record_life; |
d2ddc776 DH |
351 | write_unlock(&volume->servers_lock); |
352 | ret = 0; | |
1da177e4 | 353 | |
d2ddc776 DH |
354 | afs_put_serverlist(volume->cell->net, discard); |
355 | error_vldb: | |
356 | kfree(vldb); | |
357 | error: | |
358 | _leave(" = %d", ret); | |
359 | return ret; | |
360 | } | |
1da177e4 | 361 | |
d2ddc776 DH |
362 | /* |
363 | * Make sure the volume record is up to date. | |
364 | */ | |
e49c7b2f | 365 | int afs_check_volume_status(struct afs_volume *volume, struct afs_operation *op) |
d2ddc776 | 366 | { |
d2ddc776 | 367 | int ret, retries = 0; |
1da177e4 | 368 | |
d2ddc776 DH |
369 | _enter(""); |
370 | ||
d2ddc776 | 371 | retry: |
f6cbb368 DH |
372 | if (test_bit(AFS_VOLUME_WAIT, &volume->flags)) |
373 | goto wait; | |
374 | if (volume->update_at <= ktime_get_real_seconds() || | |
375 | test_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags)) | |
376 | goto update; | |
377 | _leave(" = 0"); | |
378 | return 0; | |
379 | ||
380 | update: | |
d2ddc776 | 381 | if (!test_and_set_bit_lock(AFS_VOLUME_UPDATING, &volume->flags)) { |
f6cbb368 | 382 | clear_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags); |
e49c7b2f | 383 | ret = afs_update_volume_status(volume, op->key); |
f6cbb368 DH |
384 | if (ret < 0) |
385 | set_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags); | |
d2ddc776 DH |
386 | clear_bit_unlock(AFS_VOLUME_WAIT, &volume->flags); |
387 | clear_bit_unlock(AFS_VOLUME_UPDATING, &volume->flags); | |
388 | wake_up_bit(&volume->flags, AFS_VOLUME_WAIT); | |
389 | _leave(" = %d", ret); | |
390 | return ret; | |
391 | } | |
1da177e4 | 392 | |
f6cbb368 | 393 | wait: |
d2ddc776 DH |
394 | if (!test_bit(AFS_VOLUME_WAIT, &volume->flags)) { |
395 | _leave(" = 0 [no wait]"); | |
396 | return 0; | |
397 | } | |
398 | ||
c4bfda16 | 399 | ret = wait_on_bit(&volume->flags, AFS_VOLUME_WAIT, |
e49c7b2f DH |
400 | (op->flags & AFS_OPERATION_UNINTR) ? |
401 | TASK_UNINTERRUPTIBLE : TASK_INTERRUPTIBLE); | |
d2ddc776 DH |
402 | if (ret == -ERESTARTSYS) { |
403 | _leave(" = %d", ret); | |
404 | return ret; | |
405 | } | |
406 | ||
407 | retries++; | |
408 | if (retries == 4) { | |
409 | _leave(" = -ESTALE"); | |
410 | return -ESTALE; | |
411 | } | |
412 | goto retry; | |
ec26815a | 413 | } |