1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * dlmast.c |
4 | * |
5 | * AST and BAST functionality for local and remote nodes |
6 | * |
7 | * Copyright (C) 2004 Oracle. All rights reserved. |
8 | */ |
9 | |
10 | |
11 | #include <linux/module.h> |
12 | #include <linux/fs.h> |
13 | #include <linux/types.h> |
14 | #include <linux/highmem.h> |
15 | #include <linux/init.h> |
16 | #include <linux/sysctl.h> |
17 | #include <linux/random.h> |
18 | #include <linux/blkdev.h> |
19 | #include <linux/socket.h> |
20 | #include <linux/inet.h> |
21 | #include <linux/spinlock.h> |
22 | |
23 | |
24 | #include "../cluster/heartbeat.h" |
25 | #include "../cluster/nodemanager.h" |
26 | #include "../cluster/tcp.h" |
27 | |
28 | #include "dlmapi.h" |
29 | #include "dlmcommon.h" |
30 | |
31 | #define MLOG_MASK_PREFIX ML_DLM |
32 | #include "../cluster/masklog.h" |
33 | |
34 | static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, |
35 | struct dlm_lock *lock); |
36 | static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock); |
37 | |
38 | /* Should be called as an ast gets queued to see if the new |
39 | * lock level will obsolete a pending bast. |
40 | * For example, if dlm_thread queued a bast for an EX lock that |
41 | * was blocking another EX, but before sending the bast the |
42 | * lock owner downconverted to NL, the bast is now obsolete. |
43 | * Only the ast should be sent. |
44 | * This is needed because the lock and convert paths can queue |
45 | * asts out-of-band (not waiting for dlm_thread) in order to |
46 | * allow for LKM_NOQUEUE to get immediate responses. */ |
47 | static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock) |
48 | { |
49 | assert_spin_locked(&dlm->ast_lock); |
50 | assert_spin_locked(&lock->spinlock); |
51 | |
52 | if (lock->ml.highest_blocked == LKM_IVMODE) |
53 | return 0; |
54 | BUG_ON(lock->ml.highest_blocked == LKM_NLMODE); |
55 | |
56 | if (lock->bast_pending && |
57 | list_empty(head: &lock->bast_list)) |
58 | /* old bast already sent, ok */ |
59 | return 0; |
60 | |
61 | if (lock->ml.type == LKM_EXMODE) |
62 | /* EX blocks anything left, any bast still valid */ |
63 | return 0; |
64 | else if (lock->ml.type == LKM_NLMODE) |
65 | /* NL blocks nothing, no reason to send any bast, cancel it */ |
66 | return 1; |
67 | else if (lock->ml.highest_blocked != LKM_EXMODE) |
68 | /* PR only blocks EX */ |
69 | return 1; |
70 | |
71 | return 0; |
72 | } |
73 | |
74 | void __dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock) |
75 | { |
76 | struct dlm_lock_resource *res; |
77 | |
78 | BUG_ON(!dlm); |
79 | BUG_ON(!lock); |
80 | |
81 | res = lock->lockres; |
82 | |
83 | assert_spin_locked(&dlm->ast_lock); |
84 | |
85 | if (!list_empty(head: &lock->ast_list)) { |
86 | mlog(ML_ERROR, "%s: res %.*s, lock %u:%llu, " |
87 | "AST list not empty, pending %d, newlevel %d\n" , |
88 | dlm->name, res->lockname.len, res->lockname.name, |
89 | dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), |
90 | dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)), |
91 | lock->ast_pending, lock->ml.type); |
92 | BUG(); |
93 | } |
94 | if (lock->ast_pending) |
95 | mlog(0, "%s: res %.*s, lock %u:%llu, AST getting flushed\n" , |
96 | dlm->name, res->lockname.len, res->lockname.name, |
97 | dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), |
98 | dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie))); |
99 | |
100 | /* putting lock on list, add a ref */ |
101 | dlm_lock_get(lock); |
102 | spin_lock(lock: &lock->spinlock); |
103 | |
104 | /* check to see if this ast obsoletes the bast */ |
105 | if (dlm_should_cancel_bast(dlm, lock)) { |
106 | mlog(0, "%s: res %.*s, lock %u:%llu, Cancelling BAST\n" , |
107 | dlm->name, res->lockname.len, res->lockname.name, |
108 | dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), |
109 | dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie))); |
110 | lock->bast_pending = 0; |
111 | list_del_init(entry: &lock->bast_list); |
112 | lock->ml.highest_blocked = LKM_IVMODE; |
113 | /* removing lock from list, remove a ref. guaranteed |
114 | * this won't be the last ref because of the get above, |
115 | * so res->spinlock will not be taken here */ |
116 | dlm_lock_put(lock); |
117 | /* free up the reserved bast that we are cancelling. |
118 | * guaranteed that this will not be the last reserved |
119 | * ast because *both* an ast and a bast were reserved |
120 | * to get to this point. the res->spinlock will not be |
121 | * taken here */ |
122 | dlm_lockres_release_ast(dlm, res); |
123 | } |
124 | list_add_tail(new: &lock->ast_list, head: &dlm->pending_asts); |
125 | lock->ast_pending = 1; |
126 | spin_unlock(lock: &lock->spinlock); |
127 | } |
128 | |
129 | void dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock) |
130 | { |
131 | BUG_ON(!dlm); |
132 | BUG_ON(!lock); |
133 | |
134 | spin_lock(lock: &dlm->ast_lock); |
135 | __dlm_queue_ast(dlm, lock); |
136 | spin_unlock(lock: &dlm->ast_lock); |
137 | } |
138 | |
139 | |
140 | void __dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock) |
141 | { |
142 | struct dlm_lock_resource *res; |
143 | |
144 | BUG_ON(!dlm); |
145 | BUG_ON(!lock); |
146 | |
147 | assert_spin_locked(&dlm->ast_lock); |
148 | |
149 | res = lock->lockres; |
150 | |
151 | BUG_ON(!list_empty(&lock->bast_list)); |
152 | if (lock->bast_pending) |
153 | mlog(0, "%s: res %.*s, lock %u:%llu, BAST getting flushed\n" , |
154 | dlm->name, res->lockname.len, res->lockname.name, |
155 | dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), |
156 | dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie))); |
157 | |
158 | /* putting lock on list, add a ref */ |
159 | dlm_lock_get(lock); |
160 | spin_lock(lock: &lock->spinlock); |
161 | list_add_tail(new: &lock->bast_list, head: &dlm->pending_basts); |
162 | lock->bast_pending = 1; |
163 | spin_unlock(lock: &lock->spinlock); |
164 | } |
165 | |
166 | static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, |
167 | struct dlm_lock *lock) |
168 | { |
169 | struct dlm_lockstatus *lksb = lock->lksb; |
170 | BUG_ON(!lksb); |
171 | |
172 | /* only updates if this node masters the lockres */ |
173 | spin_lock(lock: &res->spinlock); |
174 | if (res->owner == dlm->node_num) { |
175 | /* check the lksb flags for the direction */ |
176 | if (lksb->flags & DLM_LKSB_GET_LVB) { |
177 | mlog(0, "getting lvb from lockres for %s node\n" , |
178 | lock->ml.node == dlm->node_num ? "master" : |
179 | "remote" ); |
180 | memcpy(lksb->lvb, res->lvb, DLM_LVB_LEN); |
181 | } |
182 | /* Do nothing for lvb put requests - they should be done in |
183 | * place when the lock is downconverted - otherwise we risk |
184 | * racing gets and puts which could result in old lvb data |
185 | * being propagated. We leave the put flag set and clear it |
186 | * here. In the future we might want to clear it at the time |
187 | * the put is actually done. |
188 | */ |
189 | } |
190 | spin_unlock(lock: &res->spinlock); |
191 | |
192 | /* reset any lvb flags on the lksb */ |
193 | lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB); |
194 | } |
195 | |
196 | void dlm_do_local_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, |
197 | struct dlm_lock *lock) |
198 | { |
199 | dlm_astlockfunc_t *fn; |
200 | |
201 | mlog(0, "%s: res %.*s, lock %u:%llu, Local AST\n" , dlm->name, |
202 | res->lockname.len, res->lockname.name, |
203 | dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), |
204 | dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie))); |
205 | |
206 | fn = lock->ast; |
207 | BUG_ON(lock->ml.node != dlm->node_num); |
208 | |
209 | dlm_update_lvb(dlm, res, lock); |
210 | (*fn)(lock->astdata); |
211 | } |
212 | |
213 | |
214 | int dlm_do_remote_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, |
215 | struct dlm_lock *lock) |
216 | { |
217 | int ret; |
218 | struct dlm_lockstatus *lksb; |
219 | int lksbflags; |
220 | |
221 | mlog(0, "%s: res %.*s, lock %u:%llu, Remote AST\n" , dlm->name, |
222 | res->lockname.len, res->lockname.name, |
223 | dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), |
224 | dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie))); |
225 | |
226 | lksb = lock->lksb; |
227 | BUG_ON(lock->ml.node == dlm->node_num); |
228 | |
229 | lksbflags = lksb->flags; |
230 | dlm_update_lvb(dlm, res, lock); |
231 | |
232 | /* lock request came from another node |
233 | * go do the ast over there */ |
234 | ret = dlm_send_proxy_ast(dlm, res, lock, flags: lksbflags); |
235 | return ret; |
236 | } |
237 | |
238 | void dlm_do_local_bast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, |
239 | struct dlm_lock *lock, int blocked_type) |
240 | { |
241 | dlm_bastlockfunc_t *fn = lock->bast; |
242 | |
243 | BUG_ON(lock->ml.node != dlm->node_num); |
244 | |
245 | mlog(0, "%s: res %.*s, lock %u:%llu, Local BAST, blocked %d\n" , |
246 | dlm->name, res->lockname.len, res->lockname.name, |
247 | dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), |
248 | dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)), |
249 | blocked_type); |
250 | |
251 | (*fn)(lock->astdata, blocked_type); |
252 | } |
253 | |
254 | |
255 | |
256 | int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data, |
257 | void **ret_data) |
258 | { |
259 | int ret; |
260 | unsigned int locklen; |
261 | struct dlm_ctxt *dlm = data; |
262 | struct dlm_lock_resource *res = NULL; |
263 | struct dlm_lock *lock = NULL; |
264 | struct dlm_proxy_ast *past = (struct dlm_proxy_ast *) msg->buf; |
265 | char *name; |
266 | struct list_head *head = NULL; |
267 | __be64 cookie; |
268 | u32 flags; |
269 | u8 node; |
270 | |
271 | if (!dlm_grab(dlm)) { |
272 | dlm_error(DLM_REJECTED); |
273 | return DLM_REJECTED; |
274 | } |
275 | |
276 | mlog_bug_on_msg(!dlm_domain_fully_joined(dlm), |
277 | "Domain %s not fully joined!\n" , dlm->name); |
278 | |
279 | name = past->name; |
280 | locklen = past->namelen; |
281 | cookie = past->cookie; |
282 | flags = be32_to_cpu(past->flags); |
283 | node = past->node_idx; |
284 | |
285 | if (locklen > DLM_LOCKID_NAME_MAX) { |
286 | ret = DLM_IVBUFLEN; |
287 | mlog(ML_ERROR, "Invalid name length (%d) in proxy ast " |
288 | "handler!\n" , locklen); |
289 | goto leave; |
290 | } |
291 | |
292 | if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) == |
293 | (LKM_PUT_LVB|LKM_GET_LVB)) { |
294 | mlog(ML_ERROR, "Both PUT and GET lvb specified, (0x%x)\n" , |
295 | flags); |
296 | ret = DLM_BADARGS; |
297 | goto leave; |
298 | } |
299 | |
300 | mlog(0, "lvb: %s\n" , flags & LKM_PUT_LVB ? "put lvb" : |
301 | (flags & LKM_GET_LVB ? "get lvb" : "none" )); |
302 | |
303 | mlog(0, "type=%d, blocked_type=%d\n" , past->type, past->blocked_type); |
304 | |
305 | if (past->type != DLM_AST && |
306 | past->type != DLM_BAST) { |
307 | mlog(ML_ERROR, "Unknown ast type! %d, cookie=%u:%llu" |
308 | "name=%.*s, node=%u\n" , past->type, |
309 | dlm_get_lock_cookie_node(be64_to_cpu(cookie)), |
310 | dlm_get_lock_cookie_seq(be64_to_cpu(cookie)), |
311 | locklen, name, node); |
312 | ret = DLM_IVLOCKID; |
313 | goto leave; |
314 | } |
315 | |
316 | res = dlm_lookup_lockres(dlm, name, len: locklen); |
317 | if (!res) { |
318 | mlog(0, "Got %sast for unknown lockres! cookie=%u:%llu, " |
319 | "name=%.*s, node=%u\n" , (past->type == DLM_AST ? "" : "b" ), |
320 | dlm_get_lock_cookie_node(be64_to_cpu(cookie)), |
321 | dlm_get_lock_cookie_seq(be64_to_cpu(cookie)), |
322 | locklen, name, node); |
323 | ret = DLM_IVLOCKID; |
324 | goto leave; |
325 | } |
326 | |
327 | /* cannot get a proxy ast message if this node owns it */ |
328 | BUG_ON(res->owner == dlm->node_num); |
329 | |
330 | mlog(0, "%s: res %.*s\n" , dlm->name, res->lockname.len, |
331 | res->lockname.name); |
332 | |
333 | spin_lock(lock: &res->spinlock); |
334 | if (res->state & DLM_LOCK_RES_RECOVERING) { |
335 | mlog(0, "Responding with DLM_RECOVERING!\n" ); |
336 | ret = DLM_RECOVERING; |
337 | goto unlock_out; |
338 | } |
339 | if (res->state & DLM_LOCK_RES_MIGRATING) { |
340 | mlog(0, "Responding with DLM_MIGRATING!\n" ); |
341 | ret = DLM_MIGRATING; |
342 | goto unlock_out; |
343 | } |
344 | /* try convert queue for both ast/bast */ |
345 | head = &res->converting; |
346 | lock = NULL; |
347 | list_for_each_entry(lock, head, list) { |
348 | if (lock->ml.cookie == cookie) |
349 | goto do_ast; |
350 | } |
351 | |
352 | /* if not on convert, try blocked for ast, granted for bast */ |
353 | if (past->type == DLM_AST) |
354 | head = &res->blocked; |
355 | else |
356 | head = &res->granted; |
357 | |
358 | list_for_each_entry(lock, head, list) { |
359 | /* if lock is found but unlock is pending ignore the bast */ |
360 | if (lock->ml.cookie == cookie) { |
361 | if (lock->unlock_pending) |
362 | break; |
363 | goto do_ast; |
364 | } |
365 | } |
366 | |
367 | mlog(0, "Got %sast for unknown lock! cookie=%u:%llu, name=%.*s, " |
368 | "node=%u\n" , past->type == DLM_AST ? "" : "b" , |
369 | dlm_get_lock_cookie_node(be64_to_cpu(cookie)), |
370 | dlm_get_lock_cookie_seq(be64_to_cpu(cookie)), |
371 | locklen, name, node); |
372 | |
373 | ret = DLM_NORMAL; |
374 | unlock_out: |
375 | spin_unlock(lock: &res->spinlock); |
376 | goto leave; |
377 | |
378 | do_ast: |
379 | ret = DLM_NORMAL; |
380 | if (past->type == DLM_AST) { |
381 | /* do not alter lock refcount. switching lists. */ |
382 | list_move_tail(list: &lock->list, head: &res->granted); |
383 | mlog(0, "%s: res %.*s, lock %u:%llu, Granted type %d => %d\n" , |
384 | dlm->name, res->lockname.len, res->lockname.name, |
385 | dlm_get_lock_cookie_node(be64_to_cpu(cookie)), |
386 | dlm_get_lock_cookie_seq(be64_to_cpu(cookie)), |
387 | lock->ml.type, lock->ml.convert_type); |
388 | |
389 | if (lock->ml.convert_type != LKM_IVMODE) { |
390 | lock->ml.type = lock->ml.convert_type; |
391 | lock->ml.convert_type = LKM_IVMODE; |
392 | } else { |
393 | // should already be there.... |
394 | } |
395 | |
396 | lock->lksb->status = DLM_NORMAL; |
397 | |
398 | /* if we requested the lvb, fetch it into our lksb now */ |
399 | if (flags & LKM_GET_LVB) { |
400 | BUG_ON(!(lock->lksb->flags & DLM_LKSB_GET_LVB)); |
401 | memcpy(lock->lksb->lvb, past->lvb, DLM_LVB_LEN); |
402 | } |
403 | } |
404 | spin_unlock(lock: &res->spinlock); |
405 | |
406 | if (past->type == DLM_AST) |
407 | dlm_do_local_ast(dlm, res, lock); |
408 | else |
409 | dlm_do_local_bast(dlm, res, lock, blocked_type: past->blocked_type); |
410 | |
411 | leave: |
412 | if (res) |
413 | dlm_lockres_put(res); |
414 | |
415 | dlm_put(dlm); |
416 | return ret; |
417 | } |
418 | |
419 | |
420 | |
421 | int dlm_send_proxy_ast_msg(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, |
422 | struct dlm_lock *lock, int msg_type, |
423 | int blocked_type, int flags) |
424 | { |
425 | int ret = 0; |
426 | struct dlm_proxy_ast past; |
427 | struct kvec vec[2]; |
428 | size_t veclen = 1; |
429 | int status; |
430 | |
431 | mlog(0, "%s: res %.*s, to %u, type %d, blocked_type %d\n" , dlm->name, |
432 | res->lockname.len, res->lockname.name, lock->ml.node, msg_type, |
433 | blocked_type); |
434 | |
435 | memset(&past, 0, sizeof(struct dlm_proxy_ast)); |
436 | past.node_idx = dlm->node_num; |
437 | past.type = msg_type; |
438 | past.blocked_type = blocked_type; |
439 | past.namelen = res->lockname.len; |
440 | memcpy(past.name, res->lockname.name, past.namelen); |
441 | past.cookie = lock->ml.cookie; |
442 | |
443 | vec[0].iov_len = sizeof(struct dlm_proxy_ast); |
444 | vec[0].iov_base = &past; |
445 | if (flags & DLM_LKSB_GET_LVB) { |
446 | be32_add_cpu(var: &past.flags, LKM_GET_LVB); |
447 | vec[1].iov_len = DLM_LVB_LEN; |
448 | vec[1].iov_base = lock->lksb->lvb; |
449 | veclen++; |
450 | } |
451 | |
452 | ret = o2net_send_message_vec(msg_type: DLM_PROXY_AST_MSG, key: dlm->key, vec, veclen, |
453 | target_node: lock->ml.node, status: &status); |
454 | if (ret < 0) |
455 | mlog(ML_ERROR, "%s: res %.*s, error %d send AST to node %u\n" , |
456 | dlm->name, res->lockname.len, res->lockname.name, ret, |
457 | lock->ml.node); |
458 | else { |
459 | if (status == DLM_RECOVERING) { |
460 | mlog(ML_ERROR, "sent AST to node %u, it thinks this " |
461 | "node is dead!\n" , lock->ml.node); |
462 | BUG(); |
463 | } else if (status == DLM_MIGRATING) { |
464 | mlog(ML_ERROR, "sent AST to node %u, it returned " |
465 | "DLM_MIGRATING!\n" , lock->ml.node); |
466 | BUG(); |
467 | } else if (status != DLM_NORMAL && status != DLM_IVLOCKID) { |
468 | mlog(ML_ERROR, "AST to node %u returned %d!\n" , |
469 | lock->ml.node, status); |
470 | /* ignore it */ |
471 | } |
472 | ret = 0; |
473 | } |
474 | return ret; |
475 | } |
476 | |