Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-2.6] / fs / dlm / rcom.c
1 /******************************************************************************
2 *******************************************************************************
3 **
4 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
5 **  Copyright (C) 2005 Red Hat, Inc.  All rights reserved.
6 **
7 **  This copyrighted material is made available to anyone wishing to use,
8 **  modify, copy, or redistribute it subject to the terms and conditions
9 **  of the GNU General Public License v.2.
10 **
11 *******************************************************************************
12 ******************************************************************************/
13
14 #include "dlm_internal.h"
15 #include "lockspace.h"
16 #include "member.h"
17 #include "lowcomms.h"
18 #include "midcomms.h"
19 #include "rcom.h"
20 #include "recover.h"
21 #include "dir.h"
22 #include "config.h"
23 #include "memory.h"
24 #include "lock.h"
25 #include "util.h"
26
27
28 static int rcom_response(struct dlm_ls *ls)
29 {
30         return test_bit(LSFL_RCOM_READY, &ls->ls_flags);
31 }
32
33 static int create_rcom(struct dlm_ls *ls, int to_nodeid, int type, int len,
34                        struct dlm_rcom **rc_ret, struct dlm_mhandle **mh_ret)
35 {
36         struct dlm_rcom *rc;
37         struct dlm_mhandle *mh;
38         char *mb;
39         int mb_len = sizeof(struct dlm_rcom) + len;
40
41         mh = dlm_lowcomms_get_buffer(to_nodeid, mb_len, ls->ls_allocation, &mb);
42         if (!mh) {
43                 log_print("create_rcom to %d type %d len %d ENOBUFS",
44                           to_nodeid, type, len);
45                 return -ENOBUFS;
46         }
47         memset(mb, 0, mb_len);
48
49         rc = (struct dlm_rcom *) mb;
50
51         rc->rc_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
52         rc->rc_header.h_lockspace = ls->ls_global_id;
53         rc->rc_header.h_nodeid = dlm_our_nodeid();
54         rc->rc_header.h_length = mb_len;
55         rc->rc_header.h_cmd = DLM_RCOM;
56
57         rc->rc_type = type;
58
59         spin_lock(&ls->ls_recover_lock);
60         rc->rc_seq = ls->ls_recover_seq;
61         spin_unlock(&ls->ls_recover_lock);
62
63         *mh_ret = mh;
64         *rc_ret = rc;
65         return 0;
66 }
67
68 static void send_rcom(struct dlm_ls *ls, struct dlm_mhandle *mh,
69                       struct dlm_rcom *rc)
70 {
71         dlm_rcom_out(rc);
72         dlm_lowcomms_commit_buffer(mh);
73 }
74
75 /* When replying to a status request, a node also sends back its
76    configuration values.  The requesting node then checks that the remote
77    node is configured the same way as itself. */
78
79 static void make_config(struct dlm_ls *ls, struct rcom_config *rf)
80 {
81         rf->rf_lvblen = ls->ls_lvblen;
82         rf->rf_lsflags = ls->ls_exflags;
83 }
84
85 static int check_config(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
86 {
87         struct rcom_config *rf = (struct rcom_config *) rc->rc_buf;
88
89         if ((rc->rc_header.h_version & 0xFFFF0000) != DLM_HEADER_MAJOR) {
90                 log_error(ls, "version mismatch: %x nodeid %d: %x",
91                           DLM_HEADER_MAJOR | DLM_HEADER_MINOR, nodeid,
92                           rc->rc_header.h_version);
93                 return -EPROTO;
94         }
95
96         if (rf->rf_lvblen != ls->ls_lvblen ||
97             rf->rf_lsflags != ls->ls_exflags) {
98                 log_error(ls, "config mismatch: %d,%x nodeid %d: %d,%x",
99                           ls->ls_lvblen, ls->ls_exflags,
100                           nodeid, rf->rf_lvblen, rf->rf_lsflags);
101                 return -EPROTO;
102         }
103         return 0;
104 }
105
106 static void allow_sync_reply(struct dlm_ls *ls, uint64_t *new_seq)
107 {
108         spin_lock(&ls->ls_rcom_spin);
109         *new_seq = ++ls->ls_rcom_seq;
110         set_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
111         spin_unlock(&ls->ls_rcom_spin);
112 }
113
114 static void disallow_sync_reply(struct dlm_ls *ls)
115 {
116         spin_lock(&ls->ls_rcom_spin);
117         clear_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
118         clear_bit(LSFL_RCOM_READY, &ls->ls_flags);
119         spin_unlock(&ls->ls_rcom_spin);
120 }
121
122 int dlm_rcom_status(struct dlm_ls *ls, int nodeid)
123 {
124         struct dlm_rcom *rc;
125         struct dlm_mhandle *mh;
126         int error = 0;
127
128         ls->ls_recover_nodeid = nodeid;
129
130         if (nodeid == dlm_our_nodeid()) {
131                 rc = (struct dlm_rcom *) ls->ls_recover_buf;
132                 rc->rc_result = dlm_recover_status(ls);
133                 goto out;
134         }
135
136         error = create_rcom(ls, nodeid, DLM_RCOM_STATUS, 0, &rc, &mh);
137         if (error)
138                 goto out;
139
140         allow_sync_reply(ls, &rc->rc_id);
141         memset(ls->ls_recover_buf, 0, dlm_config.ci_buffer_size);
142
143         send_rcom(ls, mh, rc);
144
145         error = dlm_wait_function(ls, &rcom_response);
146         disallow_sync_reply(ls);
147         if (error)
148                 goto out;
149
150         rc = (struct dlm_rcom *) ls->ls_recover_buf;
151
152         if (rc->rc_result == -ESRCH) {
153                 /* we pretend the remote lockspace exists with 0 status */
154                 log_debug(ls, "remote node %d not ready", nodeid);
155                 rc->rc_result = 0;
156         } else
157                 error = check_config(ls, rc, nodeid);
158         /* the caller looks at rc_result for the remote recovery status */
159  out:
160         return error;
161 }
162
163 static void receive_rcom_status(struct dlm_ls *ls, struct dlm_rcom *rc_in)
164 {
165         struct dlm_rcom *rc;
166         struct dlm_mhandle *mh;
167         int error, nodeid = rc_in->rc_header.h_nodeid;
168
169         error = create_rcom(ls, nodeid, DLM_RCOM_STATUS_REPLY,
170                             sizeof(struct rcom_config), &rc, &mh);
171         if (error)
172                 return;
173         rc->rc_id = rc_in->rc_id;
174         rc->rc_seq_reply = rc_in->rc_seq;
175         rc->rc_result = dlm_recover_status(ls);
176         make_config(ls, (struct rcom_config *) rc->rc_buf);
177
178         send_rcom(ls, mh, rc);
179 }
180
181 static void receive_sync_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
182 {
183         spin_lock(&ls->ls_rcom_spin);
184         if (!test_bit(LSFL_RCOM_WAIT, &ls->ls_flags) ||
185             rc_in->rc_id != ls->ls_rcom_seq) {
186                 log_debug(ls, "reject reply %d from %d seq %llx expect %llx",
187                           rc_in->rc_type, rc_in->rc_header.h_nodeid,
188                           (unsigned long long)rc_in->rc_id,
189                           (unsigned long long)ls->ls_rcom_seq);
190                 goto out;
191         }
192         memcpy(ls->ls_recover_buf, rc_in, rc_in->rc_header.h_length);
193         set_bit(LSFL_RCOM_READY, &ls->ls_flags);
194         clear_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
195         wake_up(&ls->ls_wait_general);
196  out:
197         spin_unlock(&ls->ls_rcom_spin);
198 }
199
200 static void receive_rcom_status_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
201 {
202         receive_sync_reply(ls, rc_in);
203 }
204
205 int dlm_rcom_names(struct dlm_ls *ls, int nodeid, char *last_name, int last_len)
206 {
207         struct dlm_rcom *rc;
208         struct dlm_mhandle *mh;
209         int error = 0, len = sizeof(struct dlm_rcom);
210
211         ls->ls_recover_nodeid = nodeid;
212
213         if (nodeid == dlm_our_nodeid()) {
214                 dlm_copy_master_names(ls, last_name, last_len,
215                                       ls->ls_recover_buf + len,
216                                       dlm_config.ci_buffer_size - len, nodeid);
217                 goto out;
218         }
219
220         error = create_rcom(ls, nodeid, DLM_RCOM_NAMES, last_len, &rc, &mh);
221         if (error)
222                 goto out;
223         memcpy(rc->rc_buf, last_name, last_len);
224
225         allow_sync_reply(ls, &rc->rc_id);
226         memset(ls->ls_recover_buf, 0, dlm_config.ci_buffer_size);
227
228         send_rcom(ls, mh, rc);
229
230         error = dlm_wait_function(ls, &rcom_response);
231         disallow_sync_reply(ls);
232  out:
233         return error;
234 }
235
236 static void receive_rcom_names(struct dlm_ls *ls, struct dlm_rcom *rc_in)
237 {
238         struct dlm_rcom *rc;
239         struct dlm_mhandle *mh;
240         int error, inlen, outlen, nodeid;
241
242         nodeid = rc_in->rc_header.h_nodeid;
243         inlen = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
244         outlen = dlm_config.ci_buffer_size - sizeof(struct dlm_rcom);
245
246         error = create_rcom(ls, nodeid, DLM_RCOM_NAMES_REPLY, outlen, &rc, &mh);
247         if (error)
248                 return;
249         rc->rc_id = rc_in->rc_id;
250         rc->rc_seq_reply = rc_in->rc_seq;
251
252         dlm_copy_master_names(ls, rc_in->rc_buf, inlen, rc->rc_buf, outlen,
253                               nodeid);
254         send_rcom(ls, mh, rc);
255 }
256
257 static void receive_rcom_names_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
258 {
259         receive_sync_reply(ls, rc_in);
260 }
261
262 int dlm_send_rcom_lookup(struct dlm_rsb *r, int dir_nodeid)
263 {
264         struct dlm_rcom *rc;
265         struct dlm_mhandle *mh;
266         struct dlm_ls *ls = r->res_ls;
267         int error;
268
269         error = create_rcom(ls, dir_nodeid, DLM_RCOM_LOOKUP, r->res_length,
270                             &rc, &mh);
271         if (error)
272                 goto out;
273         memcpy(rc->rc_buf, r->res_name, r->res_length);
274         rc->rc_id = (unsigned long) r;
275
276         send_rcom(ls, mh, rc);
277  out:
278         return error;
279 }
280
281 static void receive_rcom_lookup(struct dlm_ls *ls, struct dlm_rcom *rc_in)
282 {
283         struct dlm_rcom *rc;
284         struct dlm_mhandle *mh;
285         int error, ret_nodeid, nodeid = rc_in->rc_header.h_nodeid;
286         int len = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
287
288         error = create_rcom(ls, nodeid, DLM_RCOM_LOOKUP_REPLY, 0, &rc, &mh);
289         if (error)
290                 return;
291
292         error = dlm_dir_lookup(ls, nodeid, rc_in->rc_buf, len, &ret_nodeid);
293         if (error)
294                 ret_nodeid = error;
295         rc->rc_result = ret_nodeid;
296         rc->rc_id = rc_in->rc_id;
297         rc->rc_seq_reply = rc_in->rc_seq;
298
299         send_rcom(ls, mh, rc);
300 }
301
302 static void receive_rcom_lookup_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
303 {
304         dlm_recover_master_reply(ls, rc_in);
305 }
306
307 static void pack_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb,
308                            struct rcom_lock *rl)
309 {
310         memset(rl, 0, sizeof(*rl));
311
312         rl->rl_ownpid = lkb->lkb_ownpid;
313         rl->rl_lkid = lkb->lkb_id;
314         rl->rl_exflags = lkb->lkb_exflags;
315         rl->rl_flags = lkb->lkb_flags;
316         rl->rl_lvbseq = lkb->lkb_lvbseq;
317         rl->rl_rqmode = lkb->lkb_rqmode;
318         rl->rl_grmode = lkb->lkb_grmode;
319         rl->rl_status = lkb->lkb_status;
320         rl->rl_wait_type = lkb->lkb_wait_type;
321
322         if (lkb->lkb_bastaddr)
323                 rl->rl_asts |= AST_BAST;
324         if (lkb->lkb_astaddr)
325                 rl->rl_asts |= AST_COMP;
326
327         rl->rl_namelen = r->res_length;
328         memcpy(rl->rl_name, r->res_name, r->res_length);
329
330         /* FIXME: might we have an lvb without DLM_LKF_VALBLK set ?
331            If so, receive_rcom_lock_args() won't take this copy. */
332
333         if (lkb->lkb_lvbptr)
334                 memcpy(rl->rl_lvb, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
335 }
336
337 int dlm_send_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
338 {
339         struct dlm_ls *ls = r->res_ls;
340         struct dlm_rcom *rc;
341         struct dlm_mhandle *mh;
342         struct rcom_lock *rl;
343         int error, len = sizeof(struct rcom_lock);
344
345         if (lkb->lkb_lvbptr)
346                 len += ls->ls_lvblen;
347
348         error = create_rcom(ls, r->res_nodeid, DLM_RCOM_LOCK, len, &rc, &mh);
349         if (error)
350                 goto out;
351
352         rl = (struct rcom_lock *) rc->rc_buf;
353         pack_rcom_lock(r, lkb, rl);
354         rc->rc_id = (unsigned long) r;
355
356         send_rcom(ls, mh, rc);
357  out:
358         return error;
359 }
360
361 static void receive_rcom_lock(struct dlm_ls *ls, struct dlm_rcom *rc_in)
362 {
363         struct dlm_rcom *rc;
364         struct dlm_mhandle *mh;
365         int error, nodeid = rc_in->rc_header.h_nodeid;
366
367         dlm_recover_master_copy(ls, rc_in);
368
369         error = create_rcom(ls, nodeid, DLM_RCOM_LOCK_REPLY,
370                             sizeof(struct rcom_lock), &rc, &mh);
371         if (error)
372                 return;
373
374         /* We send back the same rcom_lock struct we received, but
375            dlm_recover_master_copy() has filled in rl_remid and rl_result */
376
377         memcpy(rc->rc_buf, rc_in->rc_buf, sizeof(struct rcom_lock));
378         rc->rc_id = rc_in->rc_id;
379         rc->rc_seq_reply = rc_in->rc_seq;
380
381         send_rcom(ls, mh, rc);
382 }
383
384 static void receive_rcom_lock_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
385 {
386         dlm_recover_process_copy(ls, rc_in);
387 }
388
389 static int send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in)
390 {
391         struct dlm_rcom *rc;
392         struct rcom_config *rf;
393         struct dlm_mhandle *mh;
394         char *mb;
395         int mb_len = sizeof(struct dlm_rcom) + sizeof(struct rcom_config);
396
397         mh = dlm_lowcomms_get_buffer(nodeid, mb_len, GFP_NOFS, &mb);
398         if (!mh)
399                 return -ENOBUFS;
400         memset(mb, 0, mb_len);
401
402         rc = (struct dlm_rcom *) mb;
403
404         rc->rc_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
405         rc->rc_header.h_lockspace = rc_in->rc_header.h_lockspace;
406         rc->rc_header.h_nodeid = dlm_our_nodeid();
407         rc->rc_header.h_length = mb_len;
408         rc->rc_header.h_cmd = DLM_RCOM;
409
410         rc->rc_type = DLM_RCOM_STATUS_REPLY;
411         rc->rc_id = rc_in->rc_id;
412         rc->rc_seq_reply = rc_in->rc_seq;
413         rc->rc_result = -ESRCH;
414
415         rf = (struct rcom_config *) rc->rc_buf;
416         rf->rf_lvblen = -1;
417
418         dlm_rcom_out(rc);
419         dlm_lowcomms_commit_buffer(mh);
420
421         return 0;
422 }
423
424 static int is_old_reply(struct dlm_ls *ls, struct dlm_rcom *rc)
425 {
426         uint64_t seq;
427         int rv = 0;
428
429         switch (rc->rc_type) {
430         case DLM_RCOM_STATUS_REPLY:
431         case DLM_RCOM_NAMES_REPLY:
432         case DLM_RCOM_LOOKUP_REPLY:
433         case DLM_RCOM_LOCK_REPLY:
434                 spin_lock(&ls->ls_recover_lock);
435                 seq = ls->ls_recover_seq;
436                 spin_unlock(&ls->ls_recover_lock);
437                 if (rc->rc_seq_reply != seq) {
438                         log_debug(ls, "ignoring old reply %x from %d "
439                                       "seq_reply %llx expect %llx",
440                                       rc->rc_type, rc->rc_header.h_nodeid,
441                                       (unsigned long long)rc->rc_seq_reply,
442                                       (unsigned long long)seq);
443                         rv = 1;
444                 }
445         }
446         return rv;
447 }
448
449 /* Called by dlm_recvd; corresponds to dlm_receive_message() but special
450    recovery-only comms are sent through here. */
451
452 void dlm_receive_rcom(struct dlm_header *hd, int nodeid)
453 {
454         struct dlm_rcom *rc = (struct dlm_rcom *) hd;
455         struct dlm_ls *ls;
456
457         dlm_rcom_in(rc);
458
459         /* If the lockspace doesn't exist then still send a status message
460            back; it's possible that it just doesn't have its global_id yet. */
461
462         ls = dlm_find_lockspace_global(hd->h_lockspace);
463         if (!ls) {
464                 log_print("lockspace %x from %d type %x not found",
465                           hd->h_lockspace, nodeid, rc->rc_type);
466                 if (rc->rc_type == DLM_RCOM_STATUS)
467                         send_ls_not_ready(nodeid, rc);
468                 return;
469         }
470
471         if (dlm_recovery_stopped(ls) && (rc->rc_type != DLM_RCOM_STATUS)) {
472                 log_debug(ls, "ignoring recovery message %x from %d",
473                           rc->rc_type, nodeid);
474                 goto out;
475         }
476
477         if (is_old_reply(ls, rc))
478                 goto out;
479
480         if (nodeid != rc->rc_header.h_nodeid) {
481                 log_error(ls, "bad rcom nodeid %d from %d",
482                           rc->rc_header.h_nodeid, nodeid);
483                 goto out;
484         }
485
486         switch (rc->rc_type) {
487         case DLM_RCOM_STATUS:
488                 receive_rcom_status(ls, rc);
489                 break;
490
491         case DLM_RCOM_NAMES:
492                 receive_rcom_names(ls, rc);
493                 break;
494
495         case DLM_RCOM_LOOKUP:
496                 receive_rcom_lookup(ls, rc);
497                 break;
498
499         case DLM_RCOM_LOCK:
500                 receive_rcom_lock(ls, rc);
501                 break;
502
503         case DLM_RCOM_STATUS_REPLY:
504                 receive_rcom_status_reply(ls, rc);
505                 break;
506
507         case DLM_RCOM_NAMES_REPLY:
508                 receive_rcom_names_reply(ls, rc);
509                 break;
510
511         case DLM_RCOM_LOOKUP_REPLY:
512                 receive_rcom_lookup_reply(ls, rc);
513                 break;
514
515         case DLM_RCOM_LOCK_REPLY:
516                 receive_rcom_lock_reply(ls, rc);
517                 break;
518
519         default:
520                 DLM_ASSERT(0, printk("rc_type=%x\n", rc->rc_type););
521         }
522  out:
523         dlm_put_lockspace(ls);
524 }
525