Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
e8d6c554 DH |
2 | /* AFS file locking support |
3 | * | |
4 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | |
5 | * Written by David Howells (dhowells@redhat.com) | |
e8d6c554 DH |
6 | */ |
7 | ||
e8d6c554 DH |
8 | #include "internal.h" |
9 | ||
10 | #define AFS_LOCK_GRANTED 0 | |
11 | #define AFS_LOCK_PENDING 1 | |
4be5975a | 12 | #define AFS_LOCK_YOUR_TRY 2 |
e8d6c554 | 13 | |
f044c884 DH |
14 | struct workqueue_struct *afs_lock_manager; |
15 | ||
4be5975a | 16 | static void afs_next_locker(struct afs_vnode *vnode, int error); |
e8d6c554 DH |
17 | static void afs_fl_copy_lock(struct file_lock *new, struct file_lock *fl); |
18 | static void afs_fl_release_private(struct file_lock *fl); | |
19 | ||
6aed6285 | 20 | static const struct file_lock_operations afs_lock_ops = { |
e8d6c554 DH |
21 | .fl_copy_lock = afs_fl_copy_lock, |
22 | .fl_release_private = afs_fl_release_private, | |
23 | }; | |
24 | ||
4be5975a DH |
25 | static inline void afs_set_lock_state(struct afs_vnode *vnode, enum afs_lock_state state) |
26 | { | |
27 | _debug("STATE %u -> %u", vnode->lock_state, state); | |
28 | vnode->lock_state = state; | |
29 | } | |
30 | ||
d4696601 DH |
31 | static atomic_t afs_file_lock_debug_id; |
32 | ||
e8d6c554 DH |
33 | /* |
34 | * if the callback is broken on this vnode, then the lock may now be available | |
35 | */ | |
36 | void afs_lock_may_be_available(struct afs_vnode *vnode) | |
37 | { | |
3b6492df | 38 | _enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode); |
e8d6c554 | 39 | |
4be5975a DH |
40 | spin_lock(&vnode->lock); |
41 | if (vnode->lock_state == AFS_VNODE_LOCK_WAITING_FOR_CB) | |
42 | afs_next_locker(vnode, 0); | |
d4696601 | 43 | trace_afs_flock_ev(vnode, NULL, afs_flock_callback_break, 0); |
4be5975a | 44 | spin_unlock(&vnode->lock); |
e8d6c554 DH |
45 | } |
46 | ||
47 | /* | |
48 | * the lock will time out in 5 minutes unless we extend it, so schedule | |
49 | * extension in a bit less than that time | |
50 | */ | |
51 | static void afs_schedule_lock_extension(struct afs_vnode *vnode) | |
52 | { | |
a690f60a DH |
53 | ktime_t expires_at, now, duration; |
54 | u64 duration_j; | |
55 | ||
56 | expires_at = ktime_add_ms(vnode->locked_at, AFS_LOCKWAIT * 1000 / 2); | |
57 | now = ktime_get_real(); | |
58 | duration = ktime_sub(expires_at, now); | |
59 | if (duration <= 0) | |
60 | duration_j = 0; | |
61 | else | |
62 | duration_j = nsecs_to_jiffies(ktime_to_ns(duration)); | |
63 | ||
64 | queue_delayed_work(afs_lock_manager, &vnode->lock_work, duration_j); | |
65 | } | |
66 | ||
67 | /* | |
68 | * In the case of successful completion of a lock operation, record the time | |
69 | * the reply appeared and start the lock extension timer. | |
70 | */ | |
71 | void afs_lock_op_done(struct afs_call *call) | |
72 | { | |
e49c7b2f | 73 | struct afs_operation *op = call->op; |
5749ce92 | 74 | struct afs_vnode *vnode = op->file[0].vnode; |
a690f60a DH |
75 | |
76 | if (call->error == 0) { | |
77 | spin_lock(&vnode->lock); | |
d4696601 | 78 | trace_afs_flock_ev(vnode, NULL, afs_flock_timestamp, 0); |
7903192c | 79 | vnode->locked_at = call->issue_time; |
a690f60a DH |
80 | afs_schedule_lock_extension(vnode); |
81 | spin_unlock(&vnode->lock); | |
82 | } | |
e8d6c554 DH |
83 | } |
84 | ||
ff8e210a DH |
85 | /* |
86 | * grant one or more locks (readlocks are allowed to jump the queue if the | |
87 | * first lock in the queue is itself a readlock) | |
88 | * - the caller must hold the vnode lock | |
89 | */ | |
4be5975a | 90 | static void afs_grant_locks(struct afs_vnode *vnode) |
ff8e210a DH |
91 | { |
92 | struct file_lock *p, *_p; | |
4be5975a | 93 | bool exclusive = (vnode->lock_type == AFS_LOCK_WRITE); |
ff8e210a | 94 | |
4be5975a | 95 | list_for_each_entry_safe(p, _p, &vnode->pending_locks, fl_u.afs.link) { |
76698510 | 96 | if (!exclusive && lock_is_write(p)) |
4be5975a DH |
97 | continue; |
98 | ||
99 | list_move_tail(&p->fl_u.afs.link, &vnode->granted_locks); | |
100 | p->fl_u.afs.state = AFS_LOCK_GRANTED; | |
d4696601 | 101 | trace_afs_flock_op(vnode, p, afs_flock_op_grant); |
76698510 | 102 | locks_wake_up(p); |
4be5975a DH |
103 | } |
104 | } | |
105 | ||
106 | /* | |
107 | * If an error is specified, reject every pending lock that matches the | |
108 | * authentication and type of the lock we failed to get. If there are any | |
109 | * remaining lockers, try to wake up one of them to have a go. | |
110 | */ | |
111 | static void afs_next_locker(struct afs_vnode *vnode, int error) | |
112 | { | |
113 | struct file_lock *p, *_p, *next = NULL; | |
114 | struct key *key = vnode->lock_key; | |
76698510 | 115 | unsigned int type = F_RDLCK; |
4be5975a DH |
116 | |
117 | _enter(""); | |
118 | ||
119 | if (vnode->lock_type == AFS_LOCK_WRITE) | |
76698510 | 120 | type = F_WRLCK; |
4be5975a DH |
121 | |
122 | list_for_each_entry_safe(p, _p, &vnode->pending_locks, fl_u.afs.link) { | |
123 | if (error && | |
82a8cb96 JL |
124 | p->c.flc_type == type && |
125 | afs_file_key(p->c.flc_file) == key) { | |
4be5975a DH |
126 | list_del_init(&p->fl_u.afs.link); |
127 | p->fl_u.afs.state = error; | |
76698510 | 128 | locks_wake_up(p); |
ff8e210a | 129 | } |
4be5975a DH |
130 | |
131 | /* Select the next locker to hand off to. */ | |
82a8cb96 | 132 | if (next && (lock_is_write(next) || lock_is_read(p))) |
4be5975a DH |
133 | continue; |
134 | next = p; | |
ff8e210a | 135 | } |
4be5975a DH |
136 | |
137 | vnode->lock_key = NULL; | |
138 | key_put(key); | |
139 | ||
140 | if (next) { | |
141 | afs_set_lock_state(vnode, AFS_VNODE_LOCK_SETTING); | |
142 | next->fl_u.afs.state = AFS_LOCK_YOUR_TRY; | |
d4696601 | 143 | trace_afs_flock_op(vnode, next, afs_flock_op_wake); |
76698510 | 144 | locks_wake_up(next); |
4be5975a DH |
145 | } else { |
146 | afs_set_lock_state(vnode, AFS_VNODE_LOCK_NONE); | |
d4696601 | 147 | trace_afs_flock_ev(vnode, NULL, afs_flock_no_lockers, 0); |
4be5975a DH |
148 | } |
149 | ||
150 | _leave(""); | |
ff8e210a DH |
151 | } |
152 | ||
cdfb26b4 DH |
153 | /* |
154 | * Kill off all waiters in the the pending lock queue due to the vnode being | |
155 | * deleted. | |
156 | */ | |
157 | static void afs_kill_lockers_enoent(struct afs_vnode *vnode) | |
158 | { | |
159 | struct file_lock *p; | |
160 | ||
161 | afs_set_lock_state(vnode, AFS_VNODE_LOCK_DELETED); | |
162 | ||
163 | while (!list_empty(&vnode->pending_locks)) { | |
164 | p = list_entry(vnode->pending_locks.next, | |
165 | struct file_lock, fl_u.afs.link); | |
166 | list_del_init(&p->fl_u.afs.link); | |
167 | p->fl_u.afs.state = -ENOENT; | |
76698510 | 168 | locks_wake_up(p); |
cdfb26b4 DH |
169 | } |
170 | ||
171 | key_put(vnode->lock_key); | |
172 | vnode->lock_key = NULL; | |
ff8e210a DH |
173 | } |
174 | ||
e49c7b2f DH |
175 | static void afs_lock_success(struct afs_operation *op) |
176 | { | |
e49c7b2f | 177 | _enter("op=%08x", op->debug_id); |
e49c7b2f DH |
178 | afs_vnode_commit_status(op, &op->file[0]); |
179 | } | |
180 | ||
181 | static const struct afs_operation_ops afs_set_lock_operation = { | |
182 | .issue_afs_rpc = afs_fs_set_lock, | |
183 | .issue_yfs_rpc = yfs_fs_set_lock, | |
184 | .success = afs_lock_success, | |
728279a5 | 185 | .aborted = afs_check_for_remote_deletion, |
e49c7b2f DH |
186 | }; |
187 | ||
d2ddc776 DH |
188 | /* |
189 | * Get a lock on a file | |
190 | */ | |
191 | static int afs_set_lock(struct afs_vnode *vnode, struct key *key, | |
192 | afs_lock_type_t type) | |
193 | { | |
e49c7b2f | 194 | struct afs_operation *op; |
d2ddc776 | 195 | |
3b6492df | 196 | _enter("%s{%llx:%llu.%u},%x,%u", |
d2ddc776 DH |
197 | vnode->volume->name, |
198 | vnode->fid.vid, | |
199 | vnode->fid.vnode, | |
200 | vnode->fid.unique, | |
201 | key_serial(key), type); | |
202 | ||
e49c7b2f DH |
203 | op = afs_alloc_operation(key, vnode->volume); |
204 | if (IS_ERR(op)) | |
205 | return PTR_ERR(op); | |
a58823ac | 206 | |
e49c7b2f | 207 | afs_op_set_vnode(op, 0, vnode); |
d2ddc776 | 208 | |
e49c7b2f DH |
209 | op->lock.type = type; |
210 | op->ops = &afs_set_lock_operation; | |
211 | return afs_do_sync_operation(op); | |
d2ddc776 DH |
212 | } |
213 | ||
e49c7b2f DH |
214 | static const struct afs_operation_ops afs_extend_lock_operation = { |
215 | .issue_afs_rpc = afs_fs_extend_lock, | |
216 | .issue_yfs_rpc = yfs_fs_extend_lock, | |
217 | .success = afs_lock_success, | |
218 | }; | |
219 | ||
d2ddc776 DH |
220 | /* |
221 | * Extend a lock on a file | |
222 | */ | |
223 | static int afs_extend_lock(struct afs_vnode *vnode, struct key *key) | |
224 | { | |
e49c7b2f | 225 | struct afs_operation *op; |
d2ddc776 | 226 | |
3b6492df | 227 | _enter("%s{%llx:%llu.%u},%x", |
d2ddc776 DH |
228 | vnode->volume->name, |
229 | vnode->fid.vid, | |
230 | vnode->fid.vnode, | |
231 | vnode->fid.unique, | |
232 | key_serial(key)); | |
233 | ||
e49c7b2f DH |
234 | op = afs_alloc_operation(key, vnode->volume); |
235 | if (IS_ERR(op)) | |
236 | return PTR_ERR(op); | |
d2ddc776 | 237 | |
e49c7b2f | 238 | afs_op_set_vnode(op, 0, vnode); |
d2ddc776 | 239 | |
e49c7b2f DH |
240 | op->flags |= AFS_OPERATION_UNINTR; |
241 | op->ops = &afs_extend_lock_operation; | |
242 | return afs_do_sync_operation(op); | |
d2ddc776 DH |
243 | } |
244 | ||
e49c7b2f DH |
245 | static const struct afs_operation_ops afs_release_lock_operation = { |
246 | .issue_afs_rpc = afs_fs_release_lock, | |
247 | .issue_yfs_rpc = yfs_fs_release_lock, | |
248 | .success = afs_lock_success, | |
249 | }; | |
250 | ||
d2ddc776 DH |
251 | /* |
252 | * Release a lock on a file | |
253 | */ | |
254 | static int afs_release_lock(struct afs_vnode *vnode, struct key *key) | |
255 | { | |
e49c7b2f | 256 | struct afs_operation *op; |
d2ddc776 | 257 | |
3b6492df | 258 | _enter("%s{%llx:%llu.%u},%x", |
d2ddc776 DH |
259 | vnode->volume->name, |
260 | vnode->fid.vid, | |
261 | vnode->fid.vnode, | |
262 | vnode->fid.unique, | |
263 | key_serial(key)); | |
264 | ||
e49c7b2f DH |
265 | op = afs_alloc_operation(key, vnode->volume); |
266 | if (IS_ERR(op)) | |
267 | return PTR_ERR(op); | |
a58823ac | 268 | |
e49c7b2f | 269 | afs_op_set_vnode(op, 0, vnode); |
d2ddc776 | 270 | |
e49c7b2f DH |
271 | op->flags |= AFS_OPERATION_UNINTR; |
272 | op->ops = &afs_release_lock_operation; | |
273 | return afs_do_sync_operation(op); | |
d2ddc776 DH |
274 | } |
275 | ||
e8d6c554 DH |
276 | /* |
277 | * do work for a lock, including: | |
278 | * - probing for a lock we're waiting on but didn't get immediately | |
279 | * - extending a lock that's close to timing out | |
280 | */ | |
281 | void afs_lock_work(struct work_struct *work) | |
282 | { | |
283 | struct afs_vnode *vnode = | |
284 | container_of(work, struct afs_vnode, lock_work.work); | |
e8d6c554 DH |
285 | struct key *key; |
286 | int ret; | |
287 | ||
3b6492df | 288 | _enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode); |
e8d6c554 DH |
289 | |
290 | spin_lock(&vnode->lock); | |
291 | ||
0fafdc9f DH |
292 | again: |
293 | _debug("wstate %u for %p", vnode->lock_state, vnode); | |
294 | switch (vnode->lock_state) { | |
295 | case AFS_VNODE_LOCK_NEED_UNLOCK: | |
4be5975a | 296 | afs_set_lock_state(vnode, AFS_VNODE_LOCK_UNLOCKING); |
d4696601 | 297 | trace_afs_flock_ev(vnode, NULL, afs_flock_work_unlocking, 0); |
e8d6c554 DH |
298 | spin_unlock(&vnode->lock); |
299 | ||
300 | /* attempt to release the server lock; if it fails, we just | |
0fafdc9f DH |
301 | * wait 5 minutes and it'll expire anyway */ |
302 | ret = afs_release_lock(vnode, vnode->lock_key); | |
79ddbfa5 | 303 | if (ret < 0 && vnode->lock_state != AFS_VNODE_LOCK_DELETED) { |
cdfb26b4 DH |
304 | trace_afs_flock_ev(vnode, NULL, afs_flock_release_fail, |
305 | ret); | |
e8d6c554 | 306 | printk(KERN_WARNING "AFS:" |
3b6492df | 307 | " Failed to release lock on {%llx:%llx} error %d\n", |
e8d6c554 | 308 | vnode->fid.vid, vnode->fid.vnode, ret); |
0fafdc9f DH |
309 | } |
310 | ||
e8d6c554 | 311 | spin_lock(&vnode->lock); |
cdfb26b4 DH |
312 | if (ret == -ENOENT) |
313 | afs_kill_lockers_enoent(vnode); | |
314 | else | |
315 | afs_next_locker(vnode, 0); | |
4be5975a DH |
316 | spin_unlock(&vnode->lock); |
317 | return; | |
e8d6c554 | 318 | |
0fafdc9f DH |
319 | /* If we've already got a lock, then it must be time to extend that |
320 | * lock as AFS locks time out after 5 minutes. | |
321 | */ | |
322 | case AFS_VNODE_LOCK_GRANTED: | |
e8d6c554 DH |
323 | _debug("extend"); |
324 | ||
0fafdc9f DH |
325 | ASSERT(!list_empty(&vnode->granted_locks)); |
326 | ||
327 | key = key_get(vnode->lock_key); | |
4be5975a | 328 | afs_set_lock_state(vnode, AFS_VNODE_LOCK_EXTENDING); |
d4696601 | 329 | trace_afs_flock_ev(vnode, NULL, afs_flock_work_extending, 0); |
e8d6c554 DH |
330 | spin_unlock(&vnode->lock); |
331 | ||
0fafdc9f | 332 | ret = afs_extend_lock(vnode, key); /* RPC */ |
e8d6c554 | 333 | key_put(key); |
0fafdc9f | 334 | |
cdfb26b4 DH |
335 | if (ret < 0) { |
336 | trace_afs_flock_ev(vnode, NULL, afs_flock_extend_fail, | |
337 | ret); | |
a4e530ae KW |
338 | pr_warn("AFS: Failed to extend lock on {%llx:%llx} error %d\n", |
339 | vnode->fid.vid, vnode->fid.vnode, ret); | |
cdfb26b4 | 340 | } |
0fafdc9f DH |
341 | |
342 | spin_lock(&vnode->lock); | |
343 | ||
cdfb26b4 DH |
344 | if (ret == -ENOENT) { |
345 | afs_kill_lockers_enoent(vnode); | |
346 | spin_unlock(&vnode->lock); | |
347 | return; | |
348 | } | |
349 | ||
0fafdc9f DH |
350 | if (vnode->lock_state != AFS_VNODE_LOCK_EXTENDING) |
351 | goto again; | |
4be5975a | 352 | afs_set_lock_state(vnode, AFS_VNODE_LOCK_GRANTED); |
0fafdc9f | 353 | |
4be5975a | 354 | if (ret != 0) |
e8d6c554 DH |
355 | queue_delayed_work(afs_lock_manager, &vnode->lock_work, |
356 | HZ * 10); | |
0fafdc9f DH |
357 | spin_unlock(&vnode->lock); |
358 | _leave(" [ext]"); | |
e8d6c554 | 359 | return; |
e8d6c554 | 360 | |
4be5975a DH |
361 | /* If we're waiting for a callback to indicate lock release, we can't |
362 | * actually rely on this, so need to recheck at regular intervals. The | |
363 | * problem is that the server might not notify us if the lock just | |
364 | * expires (say because a client died) rather than being explicitly | |
365 | * released. | |
366 | */ | |
0fafdc9f | 367 | case AFS_VNODE_LOCK_WAITING_FOR_CB: |
4be5975a DH |
368 | _debug("retry"); |
369 | afs_next_locker(vnode, 0); | |
e8d6c554 | 370 | spin_unlock(&vnode->lock); |
4be5975a | 371 | return; |
e8d6c554 | 372 | |
cdfb26b4 DH |
373 | case AFS_VNODE_LOCK_DELETED: |
374 | afs_kill_lockers_enoent(vnode); | |
375 | spin_unlock(&vnode->lock); | |
376 | return; | |
0fafdc9f DH |
377 | |
378 | default: | |
379 | /* Looks like a lock request was withdrawn. */ | |
380 | spin_unlock(&vnode->lock); | |
381 | _leave(" [no]"); | |
e8d6c554 DH |
382 | return; |
383 | } | |
e8d6c554 DH |
384 | } |
385 | ||
386 | /* | |
387 | * pass responsibility for the unlocking of a vnode on the server to the | |
388 | * manager thread, lest a pending signal in the calling thread interrupt | |
389 | * AF_RXRPC | |
390 | * - the caller must hold the vnode lock | |
391 | */ | |
0fafdc9f | 392 | static void afs_defer_unlock(struct afs_vnode *vnode) |
e8d6c554 | 393 | { |
4be5975a | 394 | _enter("%u", vnode->lock_state); |
0fafdc9f | 395 | |
4be5975a DH |
396 | if (list_empty(&vnode->granted_locks) && |
397 | (vnode->lock_state == AFS_VNODE_LOCK_GRANTED || | |
398 | vnode->lock_state == AFS_VNODE_LOCK_EXTENDING)) { | |
0fafdc9f DH |
399 | cancel_delayed_work(&vnode->lock_work); |
400 | ||
4be5975a | 401 | afs_set_lock_state(vnode, AFS_VNODE_LOCK_NEED_UNLOCK); |
d4696601 | 402 | trace_afs_flock_ev(vnode, NULL, afs_flock_defer_unlock, 0); |
4be5975a | 403 | queue_delayed_work(afs_lock_manager, &vnode->lock_work, 0); |
0fafdc9f DH |
404 | } |
405 | } | |
406 | ||
407 | /* | |
408 | * Check that our view of the file metadata is up to date and check to see | |
409 | * whether we think that we have a locking permit. | |
410 | */ | |
411 | static int afs_do_setlk_check(struct afs_vnode *vnode, struct key *key, | |
6c6c1d63 | 412 | enum afs_flock_mode mode, afs_lock_type_t type) |
0fafdc9f DH |
413 | { |
414 | afs_access_t access; | |
415 | int ret; | |
416 | ||
417 | /* Make sure we've got a callback on this file and that our view of the | |
418 | * data version is up to date. | |
419 | */ | |
420 | ret = afs_validate(vnode, key); | |
421 | if (ret < 0) | |
422 | return ret; | |
423 | ||
424 | /* Check the permission set to see if we're actually going to be | |
425 | * allowed to get a lock on this file. | |
426 | */ | |
427 | ret = afs_check_permit(vnode, key, &access); | |
428 | if (ret < 0) | |
429 | return ret; | |
430 | ||
431 | /* At a rough estimation, you need LOCK, WRITE or INSERT perm to | |
432 | * read-lock a file and WRITE or INSERT perm to write-lock a file. | |
433 | * | |
434 | * We can't rely on the server to do this for us since if we want to | |
435 | * share a read lock that we already have, we won't go the server. | |
436 | */ | |
437 | if (type == AFS_LOCK_READ) { | |
438 | if (!(access & (AFS_ACE_INSERT | AFS_ACE_WRITE | AFS_ACE_LOCK))) | |
439 | return -EACCES; | |
0fafdc9f DH |
440 | } else { |
441 | if (!(access & (AFS_ACE_INSERT | AFS_ACE_WRITE))) | |
442 | return -EACCES; | |
0fafdc9f DH |
443 | } |
444 | ||
445 | return 0; | |
446 | } | |
447 | ||
e8d6c554 DH |
448 | /* |
449 | * request a lock on a file on the server | |
450 | */ | |
451 | static int afs_do_setlk(struct file *file, struct file_lock *fl) | |
452 | { | |
c65454a9 | 453 | struct inode *inode = file_inode(file); |
1c8c601a | 454 | struct afs_vnode *vnode = AFS_FS_I(inode); |
6c6c1d63 | 455 | enum afs_flock_mode mode = AFS_FS_S(inode->i_sb)->flock_mode; |
e8d6c554 | 456 | afs_lock_type_t type; |
215804a9 | 457 | struct key *key = afs_file_key(file); |
6c6c1d63 | 458 | bool partial, no_server_lock = false; |
e8d6c554 DH |
459 | int ret; |
460 | ||
6c6c1d63 DH |
461 | if (mode == afs_flock_mode_unset) |
462 | mode = afs_flock_mode_openafs; | |
e8d6c554 | 463 | |
6c6c1d63 DH |
464 | _enter("{%llx:%llu},%llu-%llu,%u,%u", |
465 | vnode->fid.vid, vnode->fid.vnode, | |
82a8cb96 | 466 | fl->fl_start, fl->fl_end, fl->c.flc_type, mode); |
e8d6c554 | 467 | |
e8d6c554 DH |
468 | fl->fl_ops = &afs_lock_ops; |
469 | INIT_LIST_HEAD(&fl->fl_u.afs.link); | |
470 | fl->fl_u.afs.state = AFS_LOCK_PENDING; | |
471 | ||
6c6c1d63 | 472 | partial = (fl->fl_start != 0 || fl->fl_end != OFFSET_MAX); |
76698510 | 473 | type = lock_is_read(fl) ? AFS_LOCK_READ : AFS_LOCK_WRITE; |
6c6c1d63 DH |
474 | if (mode == afs_flock_mode_write && partial) |
475 | type = AFS_LOCK_WRITE; | |
e8d6c554 | 476 | |
6c6c1d63 | 477 | ret = afs_do_setlk_check(vnode, key, mode, type); |
e8d6c554 | 478 | if (ret < 0) |
0fafdc9f | 479 | return ret; |
e8d6c554 | 480 | |
d4696601 | 481 | trace_afs_flock_op(vnode, fl, afs_flock_op_set_lock); |
e8d6c554 | 482 | |
6c6c1d63 DH |
483 | /* AFS3 protocol only supports full-file locks and doesn't provide any |
484 | * method of upgrade/downgrade, so we need to emulate for partial-file | |
485 | * locks. | |
486 | * | |
487 | * The OpenAFS client only gets a server lock for a full-file lock and | |
488 | * keeps partial-file locks local. Allow this behaviour to be emulated | |
489 | * (as the default). | |
0fafdc9f | 490 | */ |
6c6c1d63 DH |
491 | if (mode == afs_flock_mode_local || |
492 | (partial && mode == afs_flock_mode_openafs)) { | |
493 | no_server_lock = true; | |
494 | goto skip_server_lock; | |
ff8e210a | 495 | } |
e8d6c554 | 496 | |
e8d6c554 | 497 | spin_lock(&vnode->lock); |
0fafdc9f | 498 | list_add_tail(&fl->fl_u.afs.link, &vnode->pending_locks); |
e8d6c554 | 499 | |
cdfb26b4 DH |
500 | ret = -ENOENT; |
501 | if (vnode->lock_state == AFS_VNODE_LOCK_DELETED) | |
502 | goto error_unlock; | |
503 | ||
4be5975a DH |
504 | /* If we've already got a lock on the server then try to move to having |
505 | * the VFS grant the requested lock. Note that this means that other | |
506 | * clients may get starved out. | |
0fafdc9f | 507 | */ |
4be5975a DH |
508 | _debug("try %u", vnode->lock_state); |
509 | if (vnode->lock_state == AFS_VNODE_LOCK_GRANTED) { | |
510 | if (type == AFS_LOCK_READ) { | |
511 | _debug("instant readlock"); | |
512 | list_move_tail(&fl->fl_u.afs.link, &vnode->granted_locks); | |
513 | fl->fl_u.afs.state = AFS_LOCK_GRANTED; | |
514 | goto vnode_is_locked_u; | |
515 | } | |
e8d6c554 | 516 | |
4be5975a DH |
517 | if (vnode->lock_type == AFS_LOCK_WRITE) { |
518 | _debug("instant writelock"); | |
519 | list_move_tail(&fl->fl_u.afs.link, &vnode->granted_locks); | |
520 | fl->fl_u.afs.state = AFS_LOCK_GRANTED; | |
521 | goto vnode_is_locked_u; | |
522 | } | |
523 | } | |
e8d6c554 | 524 | |
6c6c1d63 | 525 | if (vnode->lock_state == AFS_VNODE_LOCK_NONE && |
82a8cb96 | 526 | !(fl->c.flc_flags & FL_SLEEP)) { |
6c6c1d63 DH |
527 | ret = -EAGAIN; |
528 | if (type == AFS_LOCK_READ) { | |
529 | if (vnode->status.lock_count == -1) | |
530 | goto lock_is_contended; /* Write locked */ | |
531 | } else { | |
532 | if (vnode->status.lock_count != 0) | |
533 | goto lock_is_contended; /* Locked */ | |
534 | } | |
535 | } | |
536 | ||
0fafdc9f DH |
537 | if (vnode->lock_state != AFS_VNODE_LOCK_NONE) |
538 | goto need_to_wait; | |
e8d6c554 | 539 | |
4be5975a | 540 | try_to_lock: |
0fafdc9f DH |
541 | /* We don't have a lock on this vnode and we aren't currently waiting |
542 | * for one either, so ask the server for a lock. | |
543 | * | |
544 | * Note that we need to be careful if we get interrupted by a signal | |
545 | * after dispatching the request as we may still get the lock, even | |
546 | * though we don't wait for the reply (it's not too bad a problem - the | |
4be5975a | 547 | * lock will expire in 5 mins anyway). |
0fafdc9f | 548 | */ |
d4696601 | 549 | trace_afs_flock_ev(vnode, fl, afs_flock_try_to_lock, 0); |
0fafdc9f DH |
550 | vnode->lock_key = key_get(key); |
551 | vnode->lock_type = type; | |
4be5975a | 552 | afs_set_lock_state(vnode, AFS_VNODE_LOCK_SETTING); |
e8d6c554 DH |
553 | spin_unlock(&vnode->lock); |
554 | ||
0fafdc9f | 555 | ret = afs_set_lock(vnode, key, type); /* RPC */ |
e8d6c554 DH |
556 | |
557 | spin_lock(&vnode->lock); | |
0fafdc9f | 558 | switch (ret) { |
4be5975a DH |
559 | case -EKEYREJECTED: |
560 | case -EKEYEXPIRED: | |
561 | case -EKEYREVOKED: | |
562 | case -EPERM: | |
563 | case -EACCES: | |
564 | fl->fl_u.afs.state = ret; | |
d4696601 | 565 | trace_afs_flock_ev(vnode, fl, afs_flock_fail_perm, ret); |
4be5975a DH |
566 | list_del_init(&fl->fl_u.afs.link); |
567 | afs_next_locker(vnode, ret); | |
568 | goto error_unlock; | |
569 | ||
cdfb26b4 DH |
570 | case -ENOENT: |
571 | fl->fl_u.afs.state = ret; | |
572 | trace_afs_flock_ev(vnode, fl, afs_flock_fail_other, ret); | |
573 | list_del_init(&fl->fl_u.afs.link); | |
574 | afs_kill_lockers_enoent(vnode); | |
575 | goto error_unlock; | |
576 | ||
0fafdc9f | 577 | default: |
4be5975a | 578 | fl->fl_u.afs.state = ret; |
d4696601 | 579 | trace_afs_flock_ev(vnode, fl, afs_flock_fail_other, ret); |
4be5975a DH |
580 | list_del_init(&fl->fl_u.afs.link); |
581 | afs_next_locker(vnode, 0); | |
582 | goto error_unlock; | |
e8d6c554 | 583 | |
0fafdc9f DH |
584 | case -EWOULDBLOCK: |
585 | /* The server doesn't have a lock-waiting queue, so the client | |
586 | * will have to retry. The server will break the outstanding | |
587 | * callbacks on a file when a lock is released. | |
588 | */ | |
0fafdc9f DH |
589 | ASSERT(list_empty(&vnode->granted_locks)); |
590 | ASSERTCMP(vnode->pending_locks.next, ==, &fl->fl_u.afs.link); | |
4be5975a | 591 | goto lock_is_contended; |
0fafdc9f DH |
592 | |
593 | case 0: | |
4be5975a | 594 | afs_set_lock_state(vnode, AFS_VNODE_LOCK_GRANTED); |
d4696601 | 595 | trace_afs_flock_ev(vnode, fl, afs_flock_acquired, type); |
4be5975a DH |
596 | afs_grant_locks(vnode); |
597 | goto vnode_is_locked_u; | |
e8d6c554 | 598 | } |
e8d6c554 | 599 | |
4be5975a | 600 | vnode_is_locked_u: |
0fafdc9f | 601 | spin_unlock(&vnode->lock); |
4be5975a DH |
602 | vnode_is_locked: |
603 | /* the lock has been granted by the server... */ | |
604 | ASSERTCMP(fl->fl_u.afs.state, ==, AFS_LOCK_GRANTED); | |
0fafdc9f | 605 | |
6c6c1d63 | 606 | skip_server_lock: |
4be5975a | 607 | /* ... but the VFS still needs to distribute access on this client. */ |
d4696601 | 608 | trace_afs_flock_ev(vnode, fl, afs_flock_vfs_locking, 0); |
4be5975a | 609 | ret = locks_lock_file_wait(file, fl); |
d4696601 | 610 | trace_afs_flock_ev(vnode, fl, afs_flock_vfs_lock, ret); |
e8d6c554 DH |
611 | if (ret < 0) |
612 | goto vfs_rejected_lock; | |
e8d6c554 | 613 | |
0fafdc9f | 614 | /* Again, make sure we've got a callback on this file and, again, make |
e8d6c554 | 615 | * sure that our view of the data version is up to date (we ignore |
0fafdc9f DH |
616 | * errors incurred here and deal with the consequences elsewhere). |
617 | */ | |
d2ddc776 | 618 | afs_validate(vnode, key); |
0fafdc9f DH |
619 | _leave(" = 0"); |
620 | return 0; | |
e8d6c554 | 621 | |
4be5975a | 622 | lock_is_contended: |
82a8cb96 | 623 | if (!(fl->c.flc_flags & FL_SLEEP)) { |
4be5975a DH |
624 | list_del_init(&fl->fl_u.afs.link); |
625 | afs_next_locker(vnode, 0); | |
626 | ret = -EAGAIN; | |
627 | goto error_unlock; | |
628 | } | |
629 | ||
630 | afs_set_lock_state(vnode, AFS_VNODE_LOCK_WAITING_FOR_CB); | |
d4696601 | 631 | trace_afs_flock_ev(vnode, fl, afs_flock_would_block, ret); |
4be5975a DH |
632 | queue_delayed_work(afs_lock_manager, &vnode->lock_work, HZ * 5); |
633 | ||
0fafdc9f DH |
634 | need_to_wait: |
635 | /* We're going to have to wait. Either this client doesn't have a lock | |
636 | * on the server yet and we need to wait for a callback to occur, or | |
4be5975a DH |
637 | * the client does have a lock on the server, but it's shared and we |
638 | * need an exclusive lock. | |
0fafdc9f | 639 | */ |
4be5975a | 640 | spin_unlock(&vnode->lock); |
0fafdc9f | 641 | |
d4696601 | 642 | trace_afs_flock_ev(vnode, fl, afs_flock_waiting, 0); |
82a8cb96 | 643 | ret = wait_event_interruptible(fl->c.flc_wait, |
4be5975a | 644 | fl->fl_u.afs.state != AFS_LOCK_PENDING); |
d4696601 | 645 | trace_afs_flock_ev(vnode, fl, afs_flock_waited, ret); |
0fafdc9f | 646 | |
4be5975a | 647 | if (fl->fl_u.afs.state >= 0 && fl->fl_u.afs.state != AFS_LOCK_GRANTED) { |
0fafdc9f | 648 | spin_lock(&vnode->lock); |
0fafdc9f | 649 | |
4be5975a DH |
650 | switch (fl->fl_u.afs.state) { |
651 | case AFS_LOCK_YOUR_TRY: | |
652 | fl->fl_u.afs.state = AFS_LOCK_PENDING; | |
653 | goto try_to_lock; | |
654 | case AFS_LOCK_PENDING: | |
655 | if (ret > 0) { | |
656 | /* We need to retry the lock. We may not be | |
657 | * notified by the server if it just expired | |
658 | * rather than being released. | |
659 | */ | |
660 | ASSERTCMP(vnode->lock_state, ==, AFS_VNODE_LOCK_WAITING_FOR_CB); | |
661 | afs_set_lock_state(vnode, AFS_VNODE_LOCK_SETTING); | |
662 | fl->fl_u.afs.state = AFS_LOCK_PENDING; | |
663 | goto try_to_lock; | |
664 | } | |
665 | goto error_unlock; | |
666 | case AFS_LOCK_GRANTED: | |
667 | default: | |
668 | break; | |
669 | } | |
0fafdc9f | 670 | |
4be5975a DH |
671 | spin_unlock(&vnode->lock); |
672 | } | |
0fafdc9f | 673 | |
4be5975a DH |
674 | if (fl->fl_u.afs.state == AFS_LOCK_GRANTED) |
675 | goto vnode_is_locked; | |
676 | ret = fl->fl_u.afs.state; | |
677 | goto error; | |
e8d6c554 DH |
678 | |
679 | vfs_rejected_lock: | |
0fafdc9f DH |
680 | /* The VFS rejected the lock we just obtained, so we have to discard |
681 | * what we just got. We defer this to the lock manager work item to | |
682 | * deal with. | |
683 | */ | |
e8d6c554 | 684 | _debug("vfs refused %d", ret); |
6c6c1d63 DH |
685 | if (no_server_lock) |
686 | goto error; | |
0fafdc9f | 687 | spin_lock(&vnode->lock); |
e8d6c554 | 688 | list_del_init(&fl->fl_u.afs.link); |
4be5975a DH |
689 | afs_defer_unlock(vnode); |
690 | ||
691 | error_unlock: | |
692 | spin_unlock(&vnode->lock); | |
693 | error: | |
694 | _leave(" = %d", ret); | |
695 | return ret; | |
e8d6c554 DH |
696 | } |
697 | ||
698 | /* | |
699 | * unlock on a file on the server | |
700 | */ | |
701 | static int afs_do_unlk(struct file *file, struct file_lock *fl) | |
702 | { | |
c65454a9 | 703 | struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); |
e8d6c554 DH |
704 | int ret; |
705 | ||
82a8cb96 JL |
706 | _enter("{%llx:%llu},%u", vnode->fid.vid, vnode->fid.vnode, |
707 | fl->c.flc_type); | |
e8d6c554 | 708 | |
d4696601 DH |
709 | trace_afs_flock_op(vnode, fl, afs_flock_op_unlock); |
710 | ||
0fafdc9f DH |
711 | /* Flush all pending writes before doing anything with locks. */ |
712 | vfs_fsync(file, 0); | |
713 | ||
4be5975a | 714 | ret = locks_lock_file_wait(file, fl); |
0fafdc9f DH |
715 | _leave(" = %d [%u]", ret, vnode->lock_state); |
716 | return ret; | |
e8d6c554 DH |
717 | } |
718 | ||
719 | /* | |
720 | * return information about a lock we currently hold, if indeed we hold one | |
721 | */ | |
722 | static int afs_do_getlk(struct file *file, struct file_lock *fl) | |
723 | { | |
c65454a9 | 724 | struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); |
215804a9 | 725 | struct key *key = afs_file_key(file); |
e8d6c554 DH |
726 | int ret, lock_count; |
727 | ||
728 | _enter(""); | |
729 | ||
cdfb26b4 DH |
730 | if (vnode->lock_state == AFS_VNODE_LOCK_DELETED) |
731 | return -ENOENT; | |
732 | ||
82a8cb96 | 733 | fl->c.flc_type = F_UNLCK; |
e8d6c554 | 734 | |
e8d6c554 | 735 | /* check local lock records first */ |
275afcac | 736 | posix_test_lock(file, fl); |
76698510 | 737 | if (lock_is_unlock(fl)) { |
e8d6c554 | 738 | /* no local locks; consult the server */ |
a58823ac | 739 | ret = afs_fetch_status(vnode, key, false, NULL); |
e8d6c554 DH |
740 | if (ret < 0) |
741 | goto error; | |
0fafdc9f DH |
742 | |
743 | lock_count = READ_ONCE(vnode->status.lock_count); | |
68ce801f DH |
744 | if (lock_count != 0) { |
745 | if (lock_count > 0) | |
82a8cb96 | 746 | fl->c.flc_type = F_RDLCK; |
68ce801f | 747 | else |
82a8cb96 | 748 | fl->c.flc_type = F_WRLCK; |
68ce801f DH |
749 | fl->fl_start = 0; |
750 | fl->fl_end = OFFSET_MAX; | |
82a8cb96 | 751 | fl->c.flc_pid = 0; |
68ce801f | 752 | } |
e8d6c554 DH |
753 | } |
754 | ||
0fafdc9f | 755 | ret = 0; |
e8d6c554 | 756 | error: |
82a8cb96 | 757 | _leave(" = %d [%hd]", ret, fl->c.flc_type); |
e8d6c554 DH |
758 | return ret; |
759 | } | |
760 | ||
761 | /* | |
762 | * manage POSIX locks on a file | |
763 | */ | |
764 | int afs_lock(struct file *file, int cmd, struct file_lock *fl) | |
765 | { | |
c65454a9 | 766 | struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); |
d4696601 DH |
767 | enum afs_flock_operation op; |
768 | int ret; | |
e8d6c554 | 769 | |
3b6492df | 770 | _enter("{%llx:%llu},%d,{t=%x,fl=%x,r=%Ld:%Ld}", |
e8d6c554 | 771 | vnode->fid.vid, vnode->fid.vnode, cmd, |
82a8cb96 | 772 | fl->c.flc_type, fl->c.flc_flags, |
e8d6c554 DH |
773 | (long long) fl->fl_start, (long long) fl->fl_end); |
774 | ||
e8d6c554 DH |
775 | if (IS_GETLK(cmd)) |
776 | return afs_do_getlk(file, fl); | |
d4696601 DH |
777 | |
778 | fl->fl_u.afs.debug_id = atomic_inc_return(&afs_file_lock_debug_id); | |
779 | trace_afs_flock_op(vnode, fl, afs_flock_op_lock); | |
780 | ||
76698510 | 781 | if (lock_is_unlock(fl)) |
d4696601 DH |
782 | ret = afs_do_unlk(file, fl); |
783 | else | |
784 | ret = afs_do_setlk(file, fl); | |
785 | ||
786 | switch (ret) { | |
787 | case 0: op = afs_flock_op_return_ok; break; | |
788 | case -EAGAIN: op = afs_flock_op_return_eagain; break; | |
789 | case -EDEADLK: op = afs_flock_op_return_edeadlk; break; | |
790 | default: op = afs_flock_op_return_error; break; | |
791 | } | |
792 | trace_afs_flock_op(vnode, fl, op); | |
793 | return ret; | |
e8d6c554 DH |
794 | } |
795 | ||
796 | /* | |
797 | * manage FLOCK locks on a file | |
798 | */ | |
799 | int afs_flock(struct file *file, int cmd, struct file_lock *fl) | |
800 | { | |
c65454a9 | 801 | struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); |
d4696601 DH |
802 | enum afs_flock_operation op; |
803 | int ret; | |
e8d6c554 | 804 | |
3b6492df | 805 | _enter("{%llx:%llu},%d,{t=%x,fl=%x}", |
e8d6c554 | 806 | vnode->fid.vid, vnode->fid.vnode, cmd, |
82a8cb96 | 807 | fl->c.flc_type, fl->c.flc_flags); |
e8d6c554 DH |
808 | |
809 | /* | |
810 | * No BSD flocks over NFS allowed. | |
811 | * Note: we could try to fake a POSIX lock request here by | |
812 | * using ((u32) filp | 0x80000000) or some such as the pid. | |
813 | * Not sure whether that would be unique, though, or whether | |
814 | * that would break in other places. | |
815 | */ | |
82a8cb96 | 816 | if (!(fl->c.flc_flags & FL_FLOCK)) |
e8d6c554 DH |
817 | return -ENOLCK; |
818 | ||
d4696601 DH |
819 | fl->fl_u.afs.debug_id = atomic_inc_return(&afs_file_lock_debug_id); |
820 | trace_afs_flock_op(vnode, fl, afs_flock_op_flock); | |
821 | ||
e8d6c554 | 822 | /* we're simulating flock() locks using posix locks on the server */ |
76698510 | 823 | if (lock_is_unlock(fl)) |
d4696601 DH |
824 | ret = afs_do_unlk(file, fl); |
825 | else | |
826 | ret = afs_do_setlk(file, fl); | |
827 | ||
828 | switch (ret) { | |
829 | case 0: op = afs_flock_op_return_ok; break; | |
830 | case -EAGAIN: op = afs_flock_op_return_eagain; break; | |
831 | case -EDEADLK: op = afs_flock_op_return_edeadlk; break; | |
832 | default: op = afs_flock_op_return_error; break; | |
833 | } | |
834 | trace_afs_flock_op(vnode, fl, op); | |
835 | return ret; | |
e8d6c554 DH |
836 | } |
837 | ||
838 | /* | |
839 | * the POSIX lock management core VFS code copies the lock record and adds the | |
840 | * copy into its own list, so we need to add that copy to the vnode's lock | |
841 | * queue in the same place as the original (which will be deleted shortly | |
842 | * after) | |
843 | */ | |
844 | static void afs_fl_copy_lock(struct file_lock *new, struct file_lock *fl) | |
845 | { | |
82a8cb96 | 846 | struct afs_vnode *vnode = AFS_FS_I(file_inode(fl->c.flc_file)); |
0fafdc9f | 847 | |
e8d6c554 DH |
848 | _enter(""); |
849 | ||
d4696601 DH |
850 | new->fl_u.afs.debug_id = atomic_inc_return(&afs_file_lock_debug_id); |
851 | ||
0fafdc9f | 852 | spin_lock(&vnode->lock); |
d4696601 | 853 | trace_afs_flock_op(vnode, new, afs_flock_op_copy_lock); |
e8d6c554 | 854 | list_add(&new->fl_u.afs.link, &fl->fl_u.afs.link); |
0fafdc9f | 855 | spin_unlock(&vnode->lock); |
e8d6c554 DH |
856 | } |
857 | ||
858 | /* | |
859 | * need to remove this lock from the vnode queue when it's removed from the | |
860 | * VFS's list | |
861 | */ | |
862 | static void afs_fl_release_private(struct file_lock *fl) | |
863 | { | |
82a8cb96 | 864 | struct afs_vnode *vnode = AFS_FS_I(file_inode(fl->c.flc_file)); |
0fafdc9f | 865 | |
e8d6c554 DH |
866 | _enter(""); |
867 | ||
0fafdc9f | 868 | spin_lock(&vnode->lock); |
4be5975a | 869 | |
d4696601 | 870 | trace_afs_flock_op(vnode, fl, afs_flock_op_release_lock); |
4be5975a DH |
871 | list_del_init(&fl->fl_u.afs.link); |
872 | if (list_empty(&vnode->granted_locks)) | |
873 | afs_defer_unlock(vnode); | |
874 | ||
0fafdc9f DH |
875 | _debug("state %u for %p", vnode->lock_state, vnode); |
876 | spin_unlock(&vnode->lock); | |
e8d6c554 | 877 | } |