Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/fs/lockd/svclock.c | |
4 | * | |
5 | * Handling of server-side locks, mostly of the blocked variety. | |
6 | * This is the ugliest part of lockd because we tread on very thin ice. | |
7 | * GRANT and CANCEL calls may get stuck, meet in mid-flight, etc. | |
8 | * IMNSHO introducing the grant callback into the NLM protocol was one | |
9 | * of the worst ideas Sun ever had. Except maybe for the idea of doing | |
10 | * NFS file locking at all. | |
11 | * | |
12 | * I'm trying hard to avoid race conditions by protecting most accesses | |
13 | * to a file's list of blocked locks through a semaphore. The global | |
14 | * list of blocked locks is not protected in this fashion however. | |
15 | * Therefore, some functions (such as the RPC callback for the async grant | |
16 | * call) move blocked locks towards the head of the list *while some other | |
17 | * process might be traversing it*. This should not be a problem in | |
18 | * practice, because this will only cause functions traversing the list | |
19 | * to visit some blocks twice. | |
20 | * | |
21 | * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> | |
22 | */ | |
23 | ||
1da177e4 | 24 | #include <linux/types.h> |
5a0e3ad6 | 25 | #include <linux/slab.h> |
1da177e4 LT |
26 | #include <linux/errno.h> |
27 | #include <linux/kernel.h> | |
28 | #include <linux/sched.h> | |
1da177e4 | 29 | #include <linux/sunrpc/clnt.h> |
5ccb0066 | 30 | #include <linux/sunrpc/svc_xprt.h> |
1da177e4 LT |
31 | #include <linux/lockd/nlm.h> |
32 | #include <linux/lockd/lockd.h> | |
d751a7cd | 33 | #include <linux/kthread.h> |
b840be2f | 34 | #include <linux/exportfs.h> |
1da177e4 LT |
35 | |
36 | #define NLMDBG_FACILITY NLMDBG_SVCLOCK | |
37 | ||
38 | #ifdef CONFIG_LOCKD_V4 | |
39 | #define nlm_deadlock nlm4_deadlock | |
40 | #else | |
41 | #define nlm_deadlock nlm_lck_denied | |
42 | #endif | |
43 | ||
6849c0ca | 44 | static void nlmsvc_release_block(struct nlm_block *block); |
1da177e4 | 45 | static void nlmsvc_insert_block(struct nlm_block *block, unsigned long); |
68a2d76c | 46 | static void nlmsvc_remove_block(struct nlm_block *block); |
963d8fe5 | 47 | |
5e1abf8c TM |
48 | static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock); |
49 | static void nlmsvc_freegrantargs(struct nlm_rqst *call); | |
963d8fe5 | 50 | static const struct rpc_call_ops nlmsvc_grant_ops; |
1da177e4 LT |
51 | |
52 | /* | |
53 | * The list of blocked locks to retry | |
54 | */ | |
68a2d76c | 55 | static LIST_HEAD(nlm_blocked); |
f904be9c | 56 | static DEFINE_SPINLOCK(nlm_blocked_lock); |
1da177e4 | 57 | |
10b89567 | 58 | #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) |
ffa94db6 TM |
59 | static const char *nlmdbg_cookie2a(const struct nlm_cookie *cookie) |
60 | { | |
61 | /* | |
3c519914 JL |
62 | * We can get away with a static buffer because this is only called |
63 | * from lockd, which is single-threaded. | |
ffa94db6 TM |
64 | */ |
65 | static char buf[2*NLM_MAXCOOKIELEN+1]; | |
66 | unsigned int i, len = sizeof(buf); | |
67 | char *p = buf; | |
68 | ||
69 | len--; /* allow for trailing \0 */ | |
70 | if (len < 3) | |
71 | return "???"; | |
72 | for (i = 0 ; i < cookie->len ; i++) { | |
73 | if (len < 2) { | |
74 | strcpy(p-3, "..."); | |
75 | break; | |
76 | } | |
77 | sprintf(p, "%02x", cookie->data[i]); | |
78 | p += 2; | |
79 | len -= 2; | |
80 | } | |
81 | *p = '\0'; | |
82 | ||
83 | return buf; | |
84 | } | |
85 | #endif | |
86 | ||
1da177e4 LT |
87 | /* |
88 | * Insert a blocked lock into the global list | |
89 | */ | |
90 | static void | |
f904be9c | 91 | nlmsvc_insert_block_locked(struct nlm_block *block, unsigned long when) |
1da177e4 | 92 | { |
68a2d76c OK |
93 | struct nlm_block *b; |
94 | struct list_head *pos; | |
1da177e4 LT |
95 | |
96 | dprintk("lockd: nlmsvc_insert_block(%p, %ld)\n", block, when); | |
68a2d76c OK |
97 | if (list_empty(&block->b_list)) { |
98 | kref_get(&block->b_count); | |
99 | } else { | |
100 | list_del_init(&block->b_list); | |
101 | } | |
102 | ||
103 | pos = &nlm_blocked; | |
1da177e4 LT |
104 | if (when != NLM_NEVER) { |
105 | if ((when += jiffies) == NLM_NEVER) | |
106 | when ++; | |
68a2d76c OK |
107 | list_for_each(pos, &nlm_blocked) { |
108 | b = list_entry(pos, struct nlm_block, b_list); | |
109 | if (time_after(b->b_when,when) || b->b_when == NLM_NEVER) | |
110 | break; | |
111 | } | |
112 | /* On normal exit from the loop, pos == &nlm_blocked, | |
113 | * so we will be adding to the end of the list - good | |
114 | */ | |
115 | } | |
1da177e4 | 116 | |
68a2d76c | 117 | list_add_tail(&block->b_list, pos); |
1da177e4 | 118 | block->b_when = when; |
1da177e4 LT |
119 | } |
120 | ||
f904be9c BS |
121 | static void nlmsvc_insert_block(struct nlm_block *block, unsigned long when) |
122 | { | |
123 | spin_lock(&nlm_blocked_lock); | |
124 | nlmsvc_insert_block_locked(block, when); | |
125 | spin_unlock(&nlm_blocked_lock); | |
126 | } | |
127 | ||
1da177e4 LT |
128 | /* |
129 | * Remove a block from the global list | |
130 | */ | |
68a2d76c | 131 | static inline void |
1da177e4 LT |
132 | nlmsvc_remove_block(struct nlm_block *block) |
133 | { | |
68a2d76c | 134 | if (!list_empty(&block->b_list)) { |
f904be9c | 135 | spin_lock(&nlm_blocked_lock); |
68a2d76c | 136 | list_del_init(&block->b_list); |
f904be9c | 137 | spin_unlock(&nlm_blocked_lock); |
68a2d76c | 138 | nlmsvc_release_block(block); |
1da177e4 | 139 | } |
1da177e4 LT |
140 | } |
141 | ||
142 | /* | |
d9f6eb75 | 143 | * Find a block for a given lock |
1da177e4 LT |
144 | */ |
145 | static struct nlm_block * | |
d9f6eb75 | 146 | nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock) |
1da177e4 | 147 | { |
68a2d76c | 148 | struct nlm_block *block; |
1da177e4 LT |
149 | struct file_lock *fl; |
150 | ||
151 | dprintk("lockd: nlmsvc_lookup_block f=%p pd=%d %Ld-%Ld ty=%d\n", | |
152 | file, lock->fl.fl_pid, | |
153 | (long long)lock->fl.fl_start, | |
154 | (long long)lock->fl.fl_end, lock->fl.fl_type); | |
68a2d76c | 155 | list_for_each_entry(block, &nlm_blocked, b_list) { |
92737230 | 156 | fl = &block->b_call->a_args.lock.fl; |
1da177e4 LT |
157 | dprintk("lockd: check f=%p pd=%d %Ld-%Ld ty=%d cookie=%s\n", |
158 | block->b_file, fl->fl_pid, | |
159 | (long long)fl->fl_start, | |
160 | (long long)fl->fl_end, fl->fl_type, | |
92737230 | 161 | nlmdbg_cookie2a(&block->b_call->a_args.cookie)); |
1da177e4 | 162 | if (block->b_file == file && nlm_compare_locks(fl, &lock->fl)) { |
6849c0ca | 163 | kref_get(&block->b_count); |
1da177e4 LT |
164 | return block; |
165 | } | |
166 | } | |
167 | ||
168 | return NULL; | |
169 | } | |
170 | ||
171 | static inline int nlm_cookie_match(struct nlm_cookie *a, struct nlm_cookie *b) | |
172 | { | |
6d7bbbba | 173 | if (a->len != b->len) |
1da177e4 | 174 | return 0; |
6d7bbbba | 175 | if (memcmp(a->data, b->data, a->len)) |
1da177e4 LT |
176 | return 0; |
177 | return 1; | |
178 | } | |
179 | ||
180 | /* | |
181 | * Find a block with a given NLM cookie. | |
182 | */ | |
183 | static inline struct nlm_block * | |
39be4502 | 184 | nlmsvc_find_block(struct nlm_cookie *cookie) |
1da177e4 LT |
185 | { |
186 | struct nlm_block *block; | |
187 | ||
68a2d76c | 188 | list_for_each_entry(block, &nlm_blocked, b_list) { |
39be4502 | 189 | if (nlm_cookie_match(&block->b_call->a_args.cookie,cookie)) |
68a2d76c | 190 | goto found; |
1da177e4 LT |
191 | } |
192 | ||
68a2d76c OK |
193 | return NULL; |
194 | ||
195 | found: | |
39be4502 | 196 | dprintk("nlmsvc_find_block(%s): block=%p\n", nlmdbg_cookie2a(cookie), block); |
68a2d76c | 197 | kref_get(&block->b_count); |
1da177e4 LT |
198 | return block; |
199 | } | |
200 | ||
201 | /* | |
202 | * Create a block and initialize it. | |
203 | * | |
204 | * Note: we explicitly set the cookie of the grant reply to that of | |
205 | * the blocked lock request. The spec explicitly mentions that the client | |
206 | * should _not_ rely on the callback containing the same cookie as the | |
207 | * request, but (as I found out later) that's because some implementations | |
208 | * do just this. Never mind the standards comittees, they support our | |
209 | * logging industries. | |
39be4502 OK |
210 | * |
211 | * 10 years later: I hope we can safely ignore these old and broken | |
212 | * clients by now. Let's fix this so we can uniquely identify an incoming | |
213 | * GRANTED_RES message by cookie, without having to rely on the client's IP | |
214 | * address. --okir | |
1da177e4 | 215 | */ |
255129d1 TM |
216 | static struct nlm_block * |
217 | nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_host *host, | |
218 | struct nlm_file *file, struct nlm_lock *lock, | |
219 | struct nlm_cookie *cookie) | |
1da177e4 LT |
220 | { |
221 | struct nlm_block *block; | |
92737230 | 222 | struct nlm_rqst *call = NULL; |
1da177e4 | 223 | |
92737230 TM |
224 | call = nlm_alloc_call(host); |
225 | if (call == NULL) | |
226 | return NULL; | |
227 | ||
1da177e4 | 228 | /* Allocate memory for block, and initialize arguments */ |
92737230 TM |
229 | block = kzalloc(sizeof(*block), GFP_KERNEL); |
230 | if (block == NULL) | |
1da177e4 | 231 | goto failed; |
6849c0ca | 232 | kref_init(&block->b_count); |
68a2d76c OK |
233 | INIT_LIST_HEAD(&block->b_list); |
234 | INIT_LIST_HEAD(&block->b_flist); | |
1da177e4 | 235 | |
92737230 | 236 | if (!nlmsvc_setgrantargs(call, lock)) |
1da177e4 LT |
237 | goto failed_free; |
238 | ||
239 | /* Set notifier function for VFS, and init args */ | |
92737230 TM |
240 | call->a_args.lock.fl.fl_flags |= FL_SLEEP; |
241 | call->a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations; | |
39be4502 | 242 | nlmclnt_next_cookie(&call->a_args.cookie); |
1da177e4 LT |
243 | |
244 | dprintk("lockd: created block %p...\n", block); | |
245 | ||
246 | /* Create and initialize the block */ | |
247 | block->b_daemon = rqstp->rq_server; | |
248 | block->b_host = host; | |
249 | block->b_file = file; | |
d9f6eb75 | 250 | file->f_count++; |
1da177e4 LT |
251 | |
252 | /* Add to file's list of blocks */ | |
68a2d76c | 253 | list_add(&block->b_flist, &file->f_blocks); |
1da177e4 LT |
254 | |
255 | /* Set up RPC arguments for callback */ | |
92737230 | 256 | block->b_call = call; |
1da177e4 | 257 | call->a_flags = RPC_TASK_ASYNC; |
92737230 | 258 | call->a_block = block; |
1da177e4 LT |
259 | |
260 | return block; | |
261 | ||
262 | failed_free: | |
263 | kfree(block); | |
264 | failed: | |
7db836d4 | 265 | nlmsvc_release_call(call); |
1da177e4 LT |
266 | return NULL; |
267 | } | |
268 | ||
269 | /* | |
3c61eecb | 270 | * Delete a block. |
1da177e4 LT |
271 | * It is the caller's responsibility to check whether the file |
272 | * can be closed hereafter. | |
273 | */ | |
6849c0ca | 274 | static int nlmsvc_unlink_block(struct nlm_block *block) |
1da177e4 | 275 | { |
09c7938c | 276 | int status; |
6849c0ca | 277 | dprintk("lockd: unlinking block %p...\n", block); |
1da177e4 LT |
278 | |
279 | /* Remove block from list */ | |
cb03f94f | 280 | status = locks_delete_block(&block->b_call->a_args.lock.fl); |
1da177e4 | 281 | nlmsvc_remove_block(block); |
6849c0ca TM |
282 | return status; |
283 | } | |
1da177e4 | 284 | |
6849c0ca TM |
285 | static void nlmsvc_free_block(struct kref *kref) |
286 | { | |
287 | struct nlm_block *block = container_of(kref, struct nlm_block, b_count); | |
288 | struct nlm_file *file = block->b_file; | |
6849c0ca TM |
289 | |
290 | dprintk("lockd: freeing block %p...\n", block); | |
1da177e4 LT |
291 | |
292 | /* Remove block from file's list of blocks */ | |
68a2d76c | 293 | list_del_init(&block->b_flist); |
89e63ef6 | 294 | mutex_unlock(&file->f_mutex); |
1da177e4 | 295 | |
92737230 | 296 | nlmsvc_freegrantargs(block->b_call); |
7db836d4 | 297 | nlmsvc_release_call(block->b_call); |
d9f6eb75 | 298 | nlm_release_file(block->b_file); |
1da177e4 | 299 | kfree(block); |
6849c0ca TM |
300 | } |
301 | ||
302 | static void nlmsvc_release_block(struct nlm_block *block) | |
303 | { | |
304 | if (block != NULL) | |
c5aa1e55 | 305 | kref_put_mutex(&block->b_count, nlmsvc_free_block, &block->b_file->f_mutex); |
1da177e4 LT |
306 | } |
307 | ||
f2af793d OK |
308 | /* |
309 | * Loop over all blocks and delete blocks held by | |
310 | * a matching host. | |
311 | */ | |
312 | void nlmsvc_traverse_blocks(struct nlm_host *host, | |
313 | struct nlm_file *file, | |
314 | nlm_host_match_fn_t match) | |
d9f6eb75 | 315 | { |
68a2d76c | 316 | struct nlm_block *block, *next; |
d9f6eb75 TM |
317 | |
318 | restart: | |
89e63ef6 | 319 | mutex_lock(&file->f_mutex); |
68a2d76c | 320 | list_for_each_entry_safe(block, next, &file->f_blocks, b_flist) { |
f2af793d | 321 | if (!match(block->b_host, host)) |
d9f6eb75 | 322 | continue; |
68a2d76c OK |
323 | /* Do not destroy blocks that are not on |
324 | * the global retry list - why? */ | |
325 | if (list_empty(&block->b_list)) | |
d9f6eb75 TM |
326 | continue; |
327 | kref_get(&block->b_count); | |
89e63ef6 | 328 | mutex_unlock(&file->f_mutex); |
d9f6eb75 TM |
329 | nlmsvc_unlink_block(block); |
330 | nlmsvc_release_block(block); | |
331 | goto restart; | |
332 | } | |
89e63ef6 | 333 | mutex_unlock(&file->f_mutex); |
d9f6eb75 TM |
334 | } |
335 | ||
89e0edfb BC |
336 | static struct nlm_lockowner * |
337 | nlmsvc_get_lockowner(struct nlm_lockowner *lockowner) | |
338 | { | |
339 | refcount_inc(&lockowner->count); | |
340 | return lockowner; | |
341 | } | |
342 | ||
184cefbe | 343 | void nlmsvc_put_lockowner(struct nlm_lockowner *lockowner) |
89e0edfb BC |
344 | { |
345 | if (!refcount_dec_and_lock(&lockowner->count, &lockowner->host->h_lock)) | |
346 | return; | |
347 | list_del(&lockowner->list); | |
348 | spin_unlock(&lockowner->host->h_lock); | |
349 | nlmsvc_release_host(lockowner->host); | |
350 | kfree(lockowner); | |
351 | } | |
352 | ||
353 | static struct nlm_lockowner *__nlmsvc_find_lockowner(struct nlm_host *host, pid_t pid) | |
354 | { | |
355 | struct nlm_lockowner *lockowner; | |
356 | list_for_each_entry(lockowner, &host->h_lockowners, list) { | |
357 | if (lockowner->pid != pid) | |
358 | continue; | |
359 | return nlmsvc_get_lockowner(lockowner); | |
360 | } | |
361 | return NULL; | |
362 | } | |
363 | ||
364 | static struct nlm_lockowner *nlmsvc_find_lockowner(struct nlm_host *host, pid_t pid) | |
365 | { | |
366 | struct nlm_lockowner *res, *new = NULL; | |
367 | ||
368 | spin_lock(&host->h_lock); | |
369 | res = __nlmsvc_find_lockowner(host, pid); | |
370 | ||
371 | if (res == NULL) { | |
372 | spin_unlock(&host->h_lock); | |
373 | new = kmalloc(sizeof(*res), GFP_KERNEL); | |
374 | spin_lock(&host->h_lock); | |
375 | res = __nlmsvc_find_lockowner(host, pid); | |
376 | if (res == NULL && new != NULL) { | |
377 | res = new; | |
378 | /* fs/locks.c will manage the refcount through lock_ops */ | |
379 | refcount_set(&new->count, 1); | |
380 | new->pid = pid; | |
381 | new->host = nlm_get_host(host); | |
382 | list_add(&new->list, &host->h_lockowners); | |
383 | new = NULL; | |
384 | } | |
385 | } | |
386 | ||
387 | spin_unlock(&host->h_lock); | |
388 | kfree(new); | |
389 | return res; | |
390 | } | |
391 | ||
392 | void | |
393 | nlmsvc_release_lockowner(struct nlm_lock *lock) | |
394 | { | |
395 | if (lock->fl.fl_owner) | |
396 | nlmsvc_put_lockowner(lock->fl.fl_owner); | |
397 | } | |
398 | ||
89e0edfb BC |
399 | void nlmsvc_locks_init_private(struct file_lock *fl, struct nlm_host *host, |
400 | pid_t pid) | |
401 | { | |
402 | fl->fl_owner = nlmsvc_find_lockowner(host, pid); | |
89e0edfb BC |
403 | } |
404 | ||
5e1abf8c TM |
405 | /* |
406 | * Initialize arguments for GRANTED call. The nlm_rqst structure | |
407 | * has been cleared already. | |
408 | */ | |
409 | static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock) | |
410 | { | |
411 | locks_copy_lock(&call->a_args.lock.fl, &lock->fl); | |
412 | memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh)); | |
e9ff3990 | 413 | call->a_args.lock.caller = utsname()->nodename; |
5e1abf8c TM |
414 | call->a_args.lock.oh.len = lock->oh.len; |
415 | ||
416 | /* set default data area */ | |
417 | call->a_args.lock.oh.data = call->a_owner; | |
646d73e9 | 418 | call->a_args.lock.svid = ((struct nlm_lockowner *)lock->fl.fl_owner)->pid; |
5e1abf8c TM |
419 | |
420 | if (lock->oh.len > NLMCLNT_OHSIZE) { | |
421 | void *data = kmalloc(lock->oh.len, GFP_KERNEL); | |
92737230 | 422 | if (!data) |
5e1abf8c | 423 | return 0; |
5e1abf8c TM |
424 | call->a_args.lock.oh.data = (u8 *) data; |
425 | } | |
426 | ||
427 | memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len); | |
428 | return 1; | |
429 | } | |
430 | ||
431 | static void nlmsvc_freegrantargs(struct nlm_rqst *call) | |
432 | { | |
92737230 | 433 | if (call->a_args.lock.oh.data != call->a_owner) |
5e1abf8c | 434 | kfree(call->a_args.lock.oh.data); |
a9e61e25 FB |
435 | |
436 | locks_release_private(&call->a_args.lock.fl); | |
5e1abf8c TM |
437 | } |
438 | ||
2b36f412 ME |
439 | /* |
440 | * Deferred lock request handling for non-blocking lock | |
441 | */ | |
ca5c8cde | 442 | static __be32 |
2b36f412 ME |
443 | nlmsvc_defer_lock_rqst(struct svc_rqst *rqstp, struct nlm_block *block) |
444 | { | |
ca5c8cde | 445 | __be32 status = nlm_lck_denied_nolocks; |
2b36f412 ME |
446 | |
447 | block->b_flags |= B_QUEUED; | |
448 | ||
449 | nlmsvc_insert_block(block, NLM_TIMEOUT); | |
450 | ||
451 | block->b_cache_req = &rqstp->rq_chandle; | |
452 | if (rqstp->rq_chandle.defer) { | |
453 | block->b_deferred_req = | |
454 | rqstp->rq_chandle.defer(block->b_cache_req); | |
455 | if (block->b_deferred_req != NULL) | |
456 | status = nlm_drop_reply; | |
457 | } | |
458 | dprintk("lockd: nlmsvc_defer_lock_rqst block %p flags %d status %d\n", | |
ca5c8cde | 459 | block, block->b_flags, ntohl(status)); |
2b36f412 ME |
460 | |
461 | return status; | |
462 | } | |
463 | ||
1da177e4 LT |
464 | /* |
465 | * Attempt to establish a lock, and if it can't be granted, block it | |
466 | * if required. | |
467 | */ | |
52921e02 | 468 | __be32 |
1da177e4 | 469 | nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, |
6cde4de8 | 470 | struct nlm_host *host, struct nlm_lock *lock, int wait, |
b2b50289 | 471 | struct nlm_cookie *cookie, int reclaim) |
1da177e4 | 472 | { |
40595cdc | 473 | #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) |
b840be2f | 474 | struct inode *inode = nlmsvc_file_inode(file); |
40595cdc BF |
475 | #endif |
476 | struct nlm_block *block = NULL; | |
1da177e4 | 477 | int error; |
7f024fcd | 478 | int mode; |
b840be2f | 479 | int async_block = 0; |
52921e02 | 480 | __be32 ret; |
1da177e4 LT |
481 | |
482 | dprintk("lockd: nlmsvc_lock(%s/%ld, ty=%d, pi=%d, %Ld-%Ld, bl=%d)\n", | |
b840be2f | 483 | inode->i_sb->s_id, inode->i_ino, |
1da177e4 LT |
484 | lock->fl.fl_type, lock->fl.fl_pid, |
485 | (long long)lock->fl.fl_start, | |
486 | (long long)lock->fl.fl_end, | |
487 | wait); | |
488 | ||
40595cdc | 489 | if (nlmsvc_file_file(file)->f_op->lock) { |
b840be2f BF |
490 | async_block = wait; |
491 | wait = 0; | |
492 | } | |
493 | ||
1da177e4 | 494 | /* Lock file against concurrent access */ |
89e63ef6 | 495 | mutex_lock(&file->f_mutex); |
f8120480 ME |
496 | /* Get existing block (in case client is busy-waiting) |
497 | * or create new block | |
498 | */ | |
d9f6eb75 | 499 | block = nlmsvc_lookup_block(file, lock); |
09c7938c | 500 | if (block == NULL) { |
560de0e6 | 501 | block = nlmsvc_create_block(rqstp, host, file, lock, cookie); |
f8120480 ME |
502 | ret = nlm_lck_denied_nolocks; |
503 | if (block == NULL) | |
504 | goto out; | |
92737230 | 505 | lock = &block->b_call->a_args.lock; |
f8120480 ME |
506 | } else |
507 | lock->fl.fl_flags &= ~FL_SLEEP; | |
1da177e4 | 508 | |
1a8322b2 ME |
509 | if (block->b_flags & B_QUEUED) { |
510 | dprintk("lockd: nlmsvc_lock deferred block %p flags %d\n", | |
511 | block, block->b_flags); | |
512 | if (block->b_granted) { | |
513 | nlmsvc_unlink_block(block); | |
514 | ret = nlm_granted; | |
515 | goto out; | |
516 | } | |
517 | if (block->b_flags & B_TIMED_OUT) { | |
518 | nlmsvc_unlink_block(block); | |
519 | ret = nlm_lck_denied; | |
520 | goto out; | |
521 | } | |
522 | ret = nlm_drop_reply; | |
523 | goto out; | |
524 | } | |
1da177e4 | 525 | |
5ccb0066 | 526 | if (locks_in_grace(SVC_NET(rqstp)) && !reclaim) { |
b2b50289 BF |
527 | ret = nlm_lck_denied_grace_period; |
528 | goto out; | |
529 | } | |
5ccb0066 | 530 | if (reclaim && !locks_in_grace(SVC_NET(rqstp))) { |
d22b1cff BF |
531 | ret = nlm_lck_denied_grace_period; |
532 | goto out; | |
533 | } | |
b2b50289 | 534 | |
1a8322b2 ME |
535 | if (!wait) |
536 | lock->fl.fl_flags &= ~FL_SLEEP; | |
7f024fcd BF |
537 | mode = lock_to_openmode(&lock->fl); |
538 | error = vfs_lock_file(file->f_file[mode], F_SETLK, &lock->fl, NULL); | |
1a8322b2 | 539 | lock->fl.fl_flags &= ~FL_SLEEP; |
a85f193e | 540 | |
1a8322b2 | 541 | dprintk("lockd: vfs_lock_file returned %d\n", error); |
6d7bbbba | 542 | switch (error) { |
1da177e4 | 543 | case 0: |
15dadef9 AA |
544 | ret = nlm_granted; |
545 | goto out; | |
09c7938c | 546 | case -EAGAIN: |
e33d1ea6 MS |
547 | /* |
548 | * If this is a blocking request for an | |
549 | * already pending lock request then we need | |
550 | * to put it back on lockd's block list | |
551 | */ | |
552 | if (wait) | |
553 | break; | |
b840be2f | 554 | ret = async_block ? nlm_lck_blocked : nlm_lck_denied; |
e33d1ea6 | 555 | goto out; |
bde74e4b | 556 | case FILE_LOCK_DEFERRED: |
1a8322b2 ME |
557 | if (wait) |
558 | break; | |
559 | /* Filesystem lock operation is in progress | |
560 | Add it to the queue waiting for callback */ | |
561 | ret = nlmsvc_defer_lock_rqst(rqstp, block); | |
562 | goto out; | |
09c7938c | 563 | case -EDEADLK: |
15dadef9 AA |
564 | ret = nlm_deadlock; |
565 | goto out; | |
1da177e4 | 566 | default: /* includes ENOLCK */ |
15dadef9 AA |
567 | ret = nlm_lck_denied_nolocks; |
568 | goto out; | |
1da177e4 LT |
569 | } |
570 | ||
09c7938c | 571 | ret = nlm_lck_blocked; |
1da177e4 LT |
572 | |
573 | /* Append to list of blocked */ | |
f8120480 | 574 | nlmsvc_insert_block(block, NLM_NEVER); |
15dadef9 | 575 | out: |
89e63ef6 | 576 | mutex_unlock(&file->f_mutex); |
6849c0ca | 577 | nlmsvc_release_block(block); |
15dadef9 AA |
578 | dprintk("lockd: nlmsvc_lock returned %u\n", ret); |
579 | return ret; | |
1da177e4 LT |
580 | } |
581 | ||
582 | /* | |
583 | * Test for presence of a conflicting lock. | |
584 | */ | |
52921e02 | 585 | __be32 |
85f3f1b3 | 586 | nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file, |
8f920d5e JL |
587 | struct nlm_host *host, struct nlm_lock *lock, |
588 | struct nlm_lock *conflock, struct nlm_cookie *cookie) | |
1da177e4 | 589 | { |
5ea0d750 | 590 | int error; |
7f024fcd | 591 | int mode; |
5ea0d750 ME |
592 | __be32 ret; |
593 | ||
1da177e4 | 594 | dprintk("lockd: nlmsvc_testlock(%s/%ld, ty=%d, %Ld-%Ld)\n", |
a81041b7 BF |
595 | nlmsvc_file_inode(file)->i_sb->s_id, |
596 | nlmsvc_file_inode(file)->i_ino, | |
1da177e4 LT |
597 | lock->fl.fl_type, |
598 | (long long)lock->fl.fl_start, | |
599 | (long long)lock->fl.fl_end); | |
600 | ||
5ccb0066 | 601 | if (locks_in_grace(SVC_NET(rqstp))) { |
b2b50289 BF |
602 | ret = nlm_lck_denied_grace_period; |
603 | goto out; | |
604 | } | |
09802fd2 | 605 | |
7f024fcd BF |
606 | mode = lock_to_openmode(&lock->fl); |
607 | error = vfs_test_lock(file->f_file[mode], &lock->fl); | |
5ea0d750 | 608 | if (error) { |
09802fd2 JL |
609 | /* We can't currently deal with deferred test requests */ |
610 | if (error == FILE_LOCK_DEFERRED) | |
611 | WARN_ON_ONCE(1); | |
612 | ||
5ea0d750 ME |
613 | ret = nlm_lck_denied_nolocks; |
614 | goto out; | |
615 | } | |
09802fd2 | 616 | |
5ea0d750 ME |
617 | if (lock->fl.fl_type == F_UNLCK) { |
618 | ret = nlm_granted; | |
619 | goto out; | |
620 | } | |
621 | ||
5ea0d750 ME |
622 | dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n", |
623 | lock->fl.fl_type, (long long)lock->fl.fl_start, | |
624 | (long long)lock->fl.fl_end); | |
625 | conflock->caller = "somehost"; /* FIXME */ | |
626 | conflock->len = strlen(conflock->caller); | |
627 | conflock->oh.len = 0; /* don't return OH info */ | |
cd2d644d | 628 | conflock->svid = lock->fl.fl_pid; |
5ea0d750 ME |
629 | conflock->fl.fl_type = lock->fl.fl_type; |
630 | conflock->fl.fl_start = lock->fl.fl_start; | |
631 | conflock->fl.fl_end = lock->fl.fl_end; | |
f328296e | 632 | locks_release_private(&lock->fl); |
89e0edfb | 633 | |
5ea0d750 ME |
634 | ret = nlm_lck_denied; |
635 | out: | |
5ea0d750 | 636 | return ret; |
1da177e4 LT |
637 | } |
638 | ||
639 | /* | |
640 | * Remove a lock. | |
641 | * This implies a CANCEL call: We send a GRANT_MSG, the client replies | |
642 | * with a GRANT_RES call which gets lost, and calls UNLOCK immediately | |
643 | * afterwards. In this case the block will still be there, and hence | |
644 | * must be removed. | |
645 | */ | |
52921e02 | 646 | __be32 |
5ccb0066 | 647 | nlmsvc_unlock(struct net *net, struct nlm_file *file, struct nlm_lock *lock) |
1da177e4 | 648 | { |
7f024fcd | 649 | int error = 0; |
1da177e4 LT |
650 | |
651 | dprintk("lockd: nlmsvc_unlock(%s/%ld, pi=%d, %Ld-%Ld)\n", | |
a81041b7 BF |
652 | nlmsvc_file_inode(file)->i_sb->s_id, |
653 | nlmsvc_file_inode(file)->i_ino, | |
1da177e4 LT |
654 | lock->fl.fl_pid, |
655 | (long long)lock->fl.fl_start, | |
656 | (long long)lock->fl.fl_end); | |
657 | ||
658 | /* First, cancel any lock that might be there */ | |
5ccb0066 | 659 | nlmsvc_cancel_blocked(net, file, lock); |
1da177e4 LT |
660 | |
661 | lock->fl.fl_type = F_UNLCK; | |
7f024fcd BF |
662 | if (file->f_file[O_RDONLY]) |
663 | error = vfs_lock_file(file->f_file[O_RDONLY], F_SETLK, | |
664 | &lock->fl, NULL); | |
665 | if (file->f_file[O_WRONLY]) | |
666 | error = vfs_lock_file(file->f_file[O_WRONLY], F_SETLK, | |
667 | &lock->fl, NULL); | |
1da177e4 LT |
668 | |
669 | return (error < 0)? nlm_lck_denied_nolocks : nlm_granted; | |
670 | } | |
671 | ||
672 | /* | |
673 | * Cancel a previously blocked request. | |
674 | * | |
675 | * A cancel request always overrides any grant that may currently | |
676 | * be in progress. | |
677 | * The calling procedure must check whether the file can be closed. | |
678 | */ | |
52921e02 | 679 | __be32 |
5ccb0066 | 680 | nlmsvc_cancel_blocked(struct net *net, struct nlm_file *file, struct nlm_lock *lock) |
1da177e4 LT |
681 | { |
682 | struct nlm_block *block; | |
64a318ee | 683 | int status = 0; |
7f024fcd | 684 | int mode; |
1da177e4 LT |
685 | |
686 | dprintk("lockd: nlmsvc_cancel(%s/%ld, pi=%d, %Ld-%Ld)\n", | |
a81041b7 BF |
687 | nlmsvc_file_inode(file)->i_sb->s_id, |
688 | nlmsvc_file_inode(file)->i_ino, | |
1da177e4 LT |
689 | lock->fl.fl_pid, |
690 | (long long)lock->fl.fl_start, | |
691 | (long long)lock->fl.fl_end); | |
692 | ||
5ccb0066 | 693 | if (locks_in_grace(net)) |
b2b50289 BF |
694 | return nlm_lck_denied_grace_period; |
695 | ||
89e63ef6 | 696 | mutex_lock(&file->f_mutex); |
d9f6eb75 | 697 | block = nlmsvc_lookup_block(file, lock); |
89e63ef6 | 698 | mutex_unlock(&file->f_mutex); |
d9f6eb75 | 699 | if (block != NULL) { |
7f024fcd BF |
700 | mode = lock_to_openmode(&lock->fl); |
701 | vfs_cancel_lock(block->b_file->f_file[mode], | |
1a8322b2 | 702 | &block->b_call->a_args.lock.fl); |
6849c0ca TM |
703 | status = nlmsvc_unlink_block(block); |
704 | nlmsvc_release_block(block); | |
705 | } | |
64a318ee | 706 | return status ? nlm_lck_denied : nlm_granted; |
1da177e4 LT |
707 | } |
708 | ||
0e4ac9d9 ME |
709 | /* |
710 | * This is a callback from the filesystem for VFS file lock requests. | |
8fb47a4f | 711 | * It will be used if lm_grant is defined and the filesystem can not |
0e4ac9d9 | 712 | * respond to the request immediately. |
0e4ac9d9 ME |
713 | * For SETLK or SETLKW request it will get the local posix lock. |
714 | * In all cases it will move the block to the head of nlm_blocked q where | |
715 | * nlmsvc_retry_blocked() can send back a reply for SETLKW or revisit the | |
716 | * deferred rpc for GETLK and SETLK. | |
717 | */ | |
718 | static void | |
d0449b90 | 719 | nlmsvc_update_deferred_block(struct nlm_block *block, int result) |
0e4ac9d9 ME |
720 | { |
721 | block->b_flags |= B_GOT_CALLBACK; | |
722 | if (result == 0) | |
723 | block->b_granted = 1; | |
724 | else | |
725 | block->b_flags |= B_TIMED_OUT; | |
0e4ac9d9 ME |
726 | } |
727 | ||
d0449b90 | 728 | static int nlmsvc_grant_deferred(struct file_lock *fl, int result) |
0e4ac9d9 ME |
729 | { |
730 | struct nlm_block *block; | |
731 | int rc = -ENOENT; | |
732 | ||
f904be9c | 733 | spin_lock(&nlm_blocked_lock); |
0e4ac9d9 ME |
734 | list_for_each_entry(block, &nlm_blocked, b_list) { |
735 | if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) { | |
736 | dprintk("lockd: nlmsvc_notify_blocked block %p flags %d\n", | |
737 | block, block->b_flags); | |
738 | if (block->b_flags & B_QUEUED) { | |
739 | if (block->b_flags & B_TIMED_OUT) { | |
740 | rc = -ENOLCK; | |
741 | break; | |
742 | } | |
d0449b90 | 743 | nlmsvc_update_deferred_block(block, result); |
0e4ac9d9 ME |
744 | } else if (result == 0) |
745 | block->b_granted = 1; | |
746 | ||
f904be9c | 747 | nlmsvc_insert_block_locked(block, 0); |
0e4ac9d9 ME |
748 | svc_wake_up(block->b_daemon); |
749 | rc = 0; | |
750 | break; | |
751 | } | |
752 | } | |
f904be9c | 753 | spin_unlock(&nlm_blocked_lock); |
0e4ac9d9 ME |
754 | if (rc == -ENOENT) |
755 | printk(KERN_WARNING "lockd: grant for unknown block\n"); | |
756 | return rc; | |
757 | } | |
758 | ||
1da177e4 LT |
759 | /* |
760 | * Unblock a blocked lock request. This is a callback invoked from the | |
761 | * VFS layer when a lock on which we blocked is removed. | |
762 | * | |
763 | * This function doesn't grant the blocked lock instantly, but rather moves | |
764 | * the block to the head of nlm_blocked where it can be picked up by lockd. | |
765 | */ | |
766 | static void | |
767 | nlmsvc_notify_blocked(struct file_lock *fl) | |
768 | { | |
68a2d76c | 769 | struct nlm_block *block; |
1da177e4 LT |
770 | |
771 | dprintk("lockd: VFS unblock notification for block %p\n", fl); | |
a282a1fa | 772 | spin_lock(&nlm_blocked_lock); |
68a2d76c | 773 | list_for_each_entry(block, &nlm_blocked, b_list) { |
92737230 | 774 | if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) { |
a282a1fa BF |
775 | nlmsvc_insert_block_locked(block, 0); |
776 | spin_unlock(&nlm_blocked_lock); | |
1da177e4 LT |
777 | svc_wake_up(block->b_daemon); |
778 | return; | |
779 | } | |
780 | } | |
a282a1fa | 781 | spin_unlock(&nlm_blocked_lock); |
1da177e4 LT |
782 | printk(KERN_WARNING "lockd: notification for unknown block!\n"); |
783 | } | |
784 | ||
7de875b2 BF |
785 | static fl_owner_t nlmsvc_get_owner(fl_owner_t owner) |
786 | { | |
787 | return nlmsvc_get_lockowner(owner); | |
788 | } | |
789 | ||
790 | static void nlmsvc_put_owner(fl_owner_t owner) | |
791 | { | |
792 | nlmsvc_put_lockowner(owner); | |
793 | } | |
794 | ||
7b021967 | 795 | const struct lock_manager_operations nlmsvc_lock_operations = { |
8fb47a4f BF |
796 | .lm_notify = nlmsvc_notify_blocked, |
797 | .lm_grant = nlmsvc_grant_deferred, | |
7de875b2 BF |
798 | .lm_get_owner = nlmsvc_get_owner, |
799 | .lm_put_owner = nlmsvc_put_owner, | |
1da177e4 LT |
800 | }; |
801 | ||
802 | /* | |
803 | * Try to claim a lock that was previously blocked. | |
804 | * | |
805 | * Note that we use both the RPC_GRANTED_MSG call _and_ an async | |
806 | * RPC thread when notifying the client. This seems like overkill... | |
807 | * Here's why: | |
808 | * - we don't want to use a synchronous RPC thread, otherwise | |
809 | * we might find ourselves hanging on a dead portmapper. | |
810 | * - Some lockd implementations (e.g. HP) don't react to | |
811 | * RPC_GRANTED calls; they seem to insist on RPC_GRANTED_MSG calls. | |
812 | */ | |
813 | static void | |
814 | nlmsvc_grant_blocked(struct nlm_block *block) | |
815 | { | |
816 | struct nlm_file *file = block->b_file; | |
92737230 | 817 | struct nlm_lock *lock = &block->b_call->a_args.lock; |
7f024fcd | 818 | int mode; |
1da177e4 | 819 | int error; |
2ec197db | 820 | loff_t fl_start, fl_end; |
1da177e4 LT |
821 | |
822 | dprintk("lockd: grant blocked lock %p\n", block); | |
823 | ||
0e4ac9d9 ME |
824 | kref_get(&block->b_count); |
825 | ||
1da177e4 | 826 | /* Unlink block request from list */ |
6849c0ca | 827 | nlmsvc_unlink_block(block); |
1da177e4 LT |
828 | |
829 | /* If b_granted is true this means we've been here before. | |
830 | * Just retry the grant callback, possibly refreshing the RPC | |
831 | * binding */ | |
832 | if (block->b_granted) { | |
833 | nlm_rebind_host(block->b_host); | |
834 | goto callback; | |
835 | } | |
836 | ||
837 | /* Try the lock operation again */ | |
2ec197db N |
838 | /* vfs_lock_file() can mangle fl_start and fl_end, but we need |
839 | * them unchanged for the GRANT_MSG | |
840 | */ | |
09c7938c | 841 | lock->fl.fl_flags |= FL_SLEEP; |
2ec197db N |
842 | fl_start = lock->fl.fl_start; |
843 | fl_end = lock->fl.fl_end; | |
7f024fcd BF |
844 | mode = lock_to_openmode(&lock->fl); |
845 | error = vfs_lock_file(file->f_file[mode], F_SETLK, &lock->fl, NULL); | |
09c7938c | 846 | lock->fl.fl_flags &= ~FL_SLEEP; |
2ec197db N |
847 | lock->fl.fl_start = fl_start; |
848 | lock->fl.fl_end = fl_end; | |
09c7938c | 849 | |
5de0e502 AA |
850 | switch (error) { |
851 | case 0: | |
852 | break; | |
bde74e4b | 853 | case FILE_LOCK_DEFERRED: |
1a8322b2 | 854 | dprintk("lockd: lock still blocked error %d\n", error); |
1da177e4 | 855 | nlmsvc_insert_block(block, NLM_NEVER); |
0e4ac9d9 | 856 | nlmsvc_release_block(block); |
d9f6eb75 | 857 | return; |
5de0e502 | 858 | default: |
1da177e4 | 859 | printk(KERN_WARNING "lockd: unexpected error %d in %s!\n", |
8e24eea7 | 860 | -error, __func__); |
1da177e4 | 861 | nlmsvc_insert_block(block, 10 * HZ); |
0e4ac9d9 | 862 | nlmsvc_release_block(block); |
d9f6eb75 | 863 | return; |
1da177e4 LT |
864 | } |
865 | ||
866 | callback: | |
867 | /* Lock was granted by VFS. */ | |
868 | dprintk("lockd: GRANTing blocked lock.\n"); | |
869 | block->b_granted = 1; | |
1da177e4 | 870 | |
9706501e JL |
871 | /* keep block on the list, but don't reattempt until the RPC |
872 | * completes or the submission fails | |
873 | */ | |
874 | nlmsvc_insert_block(block, NLM_NEVER); | |
1da177e4 | 875 | |
9706501e JL |
876 | /* Call the client -- use a soft RPC task since nlmsvc_retry_blocked |
877 | * will queue up a new one if this one times out | |
878 | */ | |
879 | error = nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG, | |
880 | &nlmsvc_grant_ops); | |
881 | ||
882 | /* RPC submission failed, wait a bit and retry */ | |
883 | if (error < 0) | |
884 | nlmsvc_insert_block(block, 10 * HZ); | |
1da177e4 LT |
885 | } |
886 | ||
887 | /* | |
888 | * This is the callback from the RPC layer when the NLM_GRANTED_MSG | |
889 | * RPC call has succeeded or timed out. | |
890 | * Like all RPC callbacks, it is invoked by the rpciod process, so it | |
891 | * better not sleep. Therefore, we put the blocked lock on the nlm_blocked | |
892 | * chain once more in order to have it removed by lockd itself (which can | |
893 | * then sleep on the file semaphore without disrupting e.g. the nfs client). | |
894 | */ | |
963d8fe5 | 895 | static void nlmsvc_grant_callback(struct rpc_task *task, void *data) |
1da177e4 | 896 | { |
963d8fe5 | 897 | struct nlm_rqst *call = data; |
92737230 | 898 | struct nlm_block *block = call->a_block; |
1da177e4 | 899 | unsigned long timeout; |
1da177e4 LT |
900 | |
901 | dprintk("lockd: GRANT_MSG RPC callback\n"); | |
1da177e4 | 902 | |
f904be9c | 903 | spin_lock(&nlm_blocked_lock); |
c64e80d5 JL |
904 | /* if the block is not on a list at this point then it has |
905 | * been invalidated. Don't try to requeue it. | |
906 | * | |
907 | * FIXME: it's possible that the block is removed from the list | |
908 | * after this check but before the nlmsvc_insert_block. In that | |
909 | * case it will be added back. Perhaps we need better locking | |
910 | * for nlm_blocked? | |
911 | */ | |
912 | if (list_empty(&block->b_list)) | |
a86dc496 | 913 | goto out; |
c64e80d5 | 914 | |
1da177e4 LT |
915 | /* Technically, we should down the file semaphore here. Since we |
916 | * move the block towards the head of the queue only, no harm | |
917 | * can be done, though. */ | |
918 | if (task->tk_status < 0) { | |
919 | /* RPC error: Re-insert for retransmission */ | |
920 | timeout = 10 * HZ; | |
1da177e4 LT |
921 | } else { |
922 | /* Call was successful, now wait for client callback */ | |
923 | timeout = 60 * HZ; | |
924 | } | |
f904be9c | 925 | nlmsvc_insert_block_locked(block, timeout); |
1da177e4 | 926 | svc_wake_up(block->b_daemon); |
a86dc496 | 927 | out: |
f904be9c | 928 | spin_unlock(&nlm_blocked_lock); |
5e1abf8c TM |
929 | } |
930 | ||
f904be9c BS |
931 | /* |
932 | * FIXME: nlmsvc_release_block() grabs a mutex. This is not allowed for an | |
933 | * .rpc_release rpc_call_op | |
934 | */ | |
ec535ce1 | 935 | static void nlmsvc_grant_release(void *data) |
5e1abf8c | 936 | { |
6041b791 | 937 | struct nlm_rqst *call = data; |
6041b791 | 938 | nlmsvc_release_block(call->a_block); |
1da177e4 LT |
939 | } |
940 | ||
963d8fe5 TM |
941 | static const struct rpc_call_ops nlmsvc_grant_ops = { |
942 | .rpc_call_done = nlmsvc_grant_callback, | |
5e1abf8c | 943 | .rpc_release = nlmsvc_grant_release, |
963d8fe5 TM |
944 | }; |
945 | ||
1da177e4 LT |
946 | /* |
947 | * We received a GRANT_RES callback. Try to find the corresponding | |
948 | * block. | |
949 | */ | |
950 | void | |
e8c5c045 | 951 | nlmsvc_grant_reply(struct nlm_cookie *cookie, __be32 status) |
1da177e4 LT |
952 | { |
953 | struct nlm_block *block; | |
1da177e4 | 954 | |
39be4502 OK |
955 | dprintk("grant_reply: looking for cookie %x, s=%d \n", |
956 | *(unsigned int *)(cookie->data), status); | |
957 | if (!(block = nlmsvc_find_block(cookie))) | |
1da177e4 | 958 | return; |
1da177e4 | 959 | |
e56efe93 CIK |
960 | if (status == nlm_lck_denied_grace_period) { |
961 | /* Try again in a couple of seconds */ | |
962 | nlmsvc_insert_block(block, 10 * HZ); | |
963 | } else { | |
964 | /* | |
965 | * Lock is now held by client, or has been rejected. | |
966 | * In both cases, the block should be removed. | |
967 | */ | |
968 | nlmsvc_unlink_block(block); | |
1da177e4 | 969 | } |
6849c0ca | 970 | nlmsvc_release_block(block); |
1da177e4 LT |
971 | } |
972 | ||
0e4ac9d9 ME |
973 | /* Helper function to handle retry of a deferred block. |
974 | * If it is a blocking lock, call grant_blocked. | |
975 | * For a non-blocking lock or test lock, revisit the request. | |
976 | */ | |
977 | static void | |
978 | retry_deferred_block(struct nlm_block *block) | |
979 | { | |
980 | if (!(block->b_flags & B_GOT_CALLBACK)) | |
981 | block->b_flags |= B_TIMED_OUT; | |
982 | nlmsvc_insert_block(block, NLM_TIMEOUT); | |
983 | dprintk("revisit block %p flags %d\n", block, block->b_flags); | |
984 | if (block->b_deferred_req) { | |
985 | block->b_deferred_req->revisit(block->b_deferred_req, 0); | |
986 | block->b_deferred_req = NULL; | |
987 | } | |
988 | } | |
989 | ||
1da177e4 LT |
990 | /* |
991 | * Retry all blocked locks that have been notified. This is where lockd | |
992 | * picks up locks that can be granted, or grant notifications that must | |
993 | * be retransmitted. | |
994 | */ | |
995 | unsigned long | |
996 | nlmsvc_retry_blocked(void) | |
997 | { | |
68a2d76c OK |
998 | unsigned long timeout = MAX_SCHEDULE_TIMEOUT; |
999 | struct nlm_block *block; | |
1000 | ||
1c327d96 | 1001 | spin_lock(&nlm_blocked_lock); |
d751a7cd | 1002 | while (!list_empty(&nlm_blocked) && !kthread_should_stop()) { |
68a2d76c | 1003 | block = list_entry(nlm_blocked.next, struct nlm_block, b_list); |
1da177e4 | 1004 | |
1da177e4 LT |
1005 | if (block->b_when == NLM_NEVER) |
1006 | break; | |
6d7bbbba | 1007 | if (time_after(block->b_when, jiffies)) { |
68a2d76c | 1008 | timeout = block->b_when - jiffies; |
1da177e4 | 1009 | break; |
68a2d76c | 1010 | } |
1c327d96 | 1011 | spin_unlock(&nlm_blocked_lock); |
68a2d76c | 1012 | |
f3d43c76 BF |
1013 | dprintk("nlmsvc_retry_blocked(%p, when=%ld)\n", |
1014 | block, block->b_when); | |
0e4ac9d9 ME |
1015 | if (block->b_flags & B_QUEUED) { |
1016 | dprintk("nlmsvc_retry_blocked delete block (%p, granted=%d, flags=%d)\n", | |
1017 | block, block->b_granted, block->b_flags); | |
1018 | retry_deferred_block(block); | |
1019 | } else | |
1020 | nlmsvc_grant_blocked(block); | |
1c327d96 | 1021 | spin_lock(&nlm_blocked_lock); |
1da177e4 | 1022 | } |
1c327d96 | 1023 | spin_unlock(&nlm_blocked_lock); |
1da177e4 | 1024 | |
68a2d76c | 1025 | return timeout; |
1da177e4 | 1026 | } |