GNU Linux-libre 6.1.86-gnu
[releases.git] / fs / ocfs2 / dlm / dlmast.c
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(&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(&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->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(&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(&lock->ast_list, &dlm->pending_asts);
125         lock->ast_pending = 1;
126         spin_unlock(&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(&dlm->ast_lock);
135         __dlm_queue_ast(dlm, lock);
136         spin_unlock(&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->spinlock);
161         list_add_tail(&lock->bast_list, &dlm->pending_basts);
162         lock->bast_pending = 1;
163         spin_unlock(&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(&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(&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, 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, 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(&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(&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(&lock->list, &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(&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, 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(&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(DLM_PROXY_AST_MSG, dlm->key, vec, veclen,
453                                      lock->ml.node, &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 }