Merge git://git.infradead.org/~dwmw2/cafe-2.6
[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, GFP_KERNEL, &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         *mh_ret = mh;
60         *rc_ret = rc;
61         return 0;
62 }
63
64 static void send_rcom(struct dlm_ls *ls, struct dlm_mhandle *mh,
65                       struct dlm_rcom *rc)
66 {
67         dlm_rcom_out(rc);
68         dlm_lowcomms_commit_buffer(mh);
69 }
70
71 /* When replying to a status request, a node also sends back its
72    configuration values.  The requesting node then checks that the remote
73    node is configured the same way as itself. */
74
75 static void make_config(struct dlm_ls *ls, struct rcom_config *rf)
76 {
77         rf->rf_lvblen = ls->ls_lvblen;
78         rf->rf_lsflags = ls->ls_exflags;
79 }
80
81 static int check_config(struct dlm_ls *ls, struct rcom_config *rf, int nodeid)
82 {
83         if (rf->rf_lvblen != ls->ls_lvblen ||
84             rf->rf_lsflags != ls->ls_exflags) {
85                 log_error(ls, "config mismatch: %d,%x nodeid %d: %d,%x",
86                           ls->ls_lvblen, ls->ls_exflags,
87                           nodeid, rf->rf_lvblen, rf->rf_lsflags);
88                 return -EINVAL;
89         }
90         return 0;
91 }
92
93 int dlm_rcom_status(struct dlm_ls *ls, int nodeid)
94 {
95         struct dlm_rcom *rc;
96         struct dlm_mhandle *mh;
97         int error = 0;
98
99         memset(ls->ls_recover_buf, 0, dlm_config.buffer_size);
100         ls->ls_recover_nodeid = nodeid;
101
102         if (nodeid == dlm_our_nodeid()) {
103                 rc = (struct dlm_rcom *) ls->ls_recover_buf;
104                 rc->rc_result = dlm_recover_status(ls);
105                 goto out;
106         }
107
108         error = create_rcom(ls, nodeid, DLM_RCOM_STATUS, 0, &rc, &mh);
109         if (error)
110                 goto out;
111         rc->rc_id = ++ls->ls_rcom_seq;
112
113         send_rcom(ls, mh, rc);
114
115         error = dlm_wait_function(ls, &rcom_response);
116         clear_bit(LSFL_RCOM_READY, &ls->ls_flags);
117         if (error)
118                 goto out;
119
120         rc = (struct dlm_rcom *) ls->ls_recover_buf;
121
122         if (rc->rc_result == -ESRCH) {
123                 /* we pretend the remote lockspace exists with 0 status */
124                 log_debug(ls, "remote node %d not ready", nodeid);
125                 rc->rc_result = 0;
126         } else
127                 error = check_config(ls, (struct rcom_config *) rc->rc_buf,
128                                      nodeid);
129         /* the caller looks at rc_result for the remote recovery status */
130  out:
131         return error;
132 }
133
134 static void receive_rcom_status(struct dlm_ls *ls, struct dlm_rcom *rc_in)
135 {
136         struct dlm_rcom *rc;
137         struct dlm_mhandle *mh;
138         int error, nodeid = rc_in->rc_header.h_nodeid;
139
140         error = create_rcom(ls, nodeid, DLM_RCOM_STATUS_REPLY,
141                             sizeof(struct rcom_config), &rc, &mh);
142         if (error)
143                 return;
144         rc->rc_id = rc_in->rc_id;
145         rc->rc_result = dlm_recover_status(ls);
146         make_config(ls, (struct rcom_config *) rc->rc_buf);
147
148         send_rcom(ls, mh, rc);
149 }
150
151 static void receive_sync_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
152 {
153         if (rc_in->rc_id != ls->ls_rcom_seq) {
154                 log_debug(ls, "reject old reply %d got %llx wanted %llx",
155                           rc_in->rc_type, rc_in->rc_id, ls->ls_rcom_seq);
156                 return;
157         }
158         memcpy(ls->ls_recover_buf, rc_in, rc_in->rc_header.h_length);
159         set_bit(LSFL_RCOM_READY, &ls->ls_flags);
160         wake_up(&ls->ls_wait_general);
161 }
162
163 static void receive_rcom_status_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
164 {
165         receive_sync_reply(ls, rc_in);
166 }
167
168 int dlm_rcom_names(struct dlm_ls *ls, int nodeid, char *last_name, int last_len)
169 {
170         struct dlm_rcom *rc;
171         struct dlm_mhandle *mh;
172         int error = 0, len = sizeof(struct dlm_rcom);
173
174         memset(ls->ls_recover_buf, 0, dlm_config.buffer_size);
175         ls->ls_recover_nodeid = nodeid;
176
177         if (nodeid == dlm_our_nodeid()) {
178                 dlm_copy_master_names(ls, last_name, last_len,
179                                       ls->ls_recover_buf + len,
180                                       dlm_config.buffer_size - len, nodeid);
181                 goto out;
182         }
183
184         error = create_rcom(ls, nodeid, DLM_RCOM_NAMES, last_len, &rc, &mh);
185         if (error)
186                 goto out;
187         memcpy(rc->rc_buf, last_name, last_len);
188         rc->rc_id = ++ls->ls_rcom_seq;
189
190         send_rcom(ls, mh, rc);
191
192         error = dlm_wait_function(ls, &rcom_response);
193         clear_bit(LSFL_RCOM_READY, &ls->ls_flags);
194  out:
195         return error;
196 }
197
198 static void receive_rcom_names(struct dlm_ls *ls, struct dlm_rcom *rc_in)
199 {
200         struct dlm_rcom *rc;
201         struct dlm_mhandle *mh;
202         int error, inlen, outlen;
203         int nodeid = rc_in->rc_header.h_nodeid;
204         uint32_t status = dlm_recover_status(ls);
205
206         /*
207          * We can't run dlm_dir_rebuild_send (which uses ls_nodes) while
208          * dlm_recoverd is running ls_nodes_reconfig (which changes ls_nodes).
209          * It could only happen in rare cases where we get a late NAMES
210          * message from a previous instance of recovery.
211          */
212
213         if (!(status & DLM_RS_NODES)) {
214                 log_debug(ls, "ignoring RCOM_NAMES from %u", nodeid);
215                 return;
216         }
217
218         nodeid = rc_in->rc_header.h_nodeid;
219         inlen = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
220         outlen = dlm_config.buffer_size - sizeof(struct dlm_rcom);
221
222         error = create_rcom(ls, nodeid, DLM_RCOM_NAMES_REPLY, outlen, &rc, &mh);
223         if (error)
224                 return;
225         rc->rc_id = rc_in->rc_id;
226
227         dlm_copy_master_names(ls, rc_in->rc_buf, inlen, rc->rc_buf, outlen,
228                               nodeid);
229         send_rcom(ls, mh, rc);
230 }
231
232 static void receive_rcom_names_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
233 {
234         receive_sync_reply(ls, rc_in);
235 }
236
237 int dlm_send_rcom_lookup(struct dlm_rsb *r, int dir_nodeid)
238 {
239         struct dlm_rcom *rc;
240         struct dlm_mhandle *mh;
241         struct dlm_ls *ls = r->res_ls;
242         int error;
243
244         error = create_rcom(ls, dir_nodeid, DLM_RCOM_LOOKUP, r->res_length,
245                             &rc, &mh);
246         if (error)
247                 goto out;
248         memcpy(rc->rc_buf, r->res_name, r->res_length);
249         rc->rc_id = (unsigned long) r;
250
251         send_rcom(ls, mh, rc);
252  out:
253         return error;
254 }
255
256 static void receive_rcom_lookup(struct dlm_ls *ls, struct dlm_rcom *rc_in)
257 {
258         struct dlm_rcom *rc;
259         struct dlm_mhandle *mh;
260         int error, ret_nodeid, nodeid = rc_in->rc_header.h_nodeid;
261         int len = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
262
263         error = create_rcom(ls, nodeid, DLM_RCOM_LOOKUP_REPLY, 0, &rc, &mh);
264         if (error)
265                 return;
266
267         error = dlm_dir_lookup(ls, nodeid, rc_in->rc_buf, len, &ret_nodeid);
268         if (error)
269                 ret_nodeid = error;
270         rc->rc_result = ret_nodeid;
271         rc->rc_id = rc_in->rc_id;
272
273         send_rcom(ls, mh, rc);
274 }
275
276 static void receive_rcom_lookup_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
277 {
278         dlm_recover_master_reply(ls, rc_in);
279 }
280
281 static void pack_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb,
282                            struct rcom_lock *rl)
283 {
284         memset(rl, 0, sizeof(*rl));
285
286         rl->rl_ownpid = lkb->lkb_ownpid;
287         rl->rl_lkid = lkb->lkb_id;
288         rl->rl_exflags = lkb->lkb_exflags;
289         rl->rl_flags = lkb->lkb_flags;
290         rl->rl_lvbseq = lkb->lkb_lvbseq;
291         rl->rl_rqmode = lkb->lkb_rqmode;
292         rl->rl_grmode = lkb->lkb_grmode;
293         rl->rl_status = lkb->lkb_status;
294         rl->rl_wait_type = lkb->lkb_wait_type;
295
296         if (lkb->lkb_bastaddr)
297                 rl->rl_asts |= AST_BAST;
298         if (lkb->lkb_astaddr)
299                 rl->rl_asts |= AST_COMP;
300
301         rl->rl_namelen = r->res_length;
302         memcpy(rl->rl_name, r->res_name, r->res_length);
303
304         /* FIXME: might we have an lvb without DLM_LKF_VALBLK set ?
305            If so, receive_rcom_lock_args() won't take this copy. */
306
307         if (lkb->lkb_lvbptr)
308                 memcpy(rl->rl_lvb, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
309 }
310
311 int dlm_send_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
312 {
313         struct dlm_ls *ls = r->res_ls;
314         struct dlm_rcom *rc;
315         struct dlm_mhandle *mh;
316         struct rcom_lock *rl;
317         int error, len = sizeof(struct rcom_lock);
318
319         if (lkb->lkb_lvbptr)
320                 len += ls->ls_lvblen;
321
322         error = create_rcom(ls, r->res_nodeid, DLM_RCOM_LOCK, len, &rc, &mh);
323         if (error)
324                 goto out;
325
326         rl = (struct rcom_lock *) rc->rc_buf;
327         pack_rcom_lock(r, lkb, rl);
328         rc->rc_id = (unsigned long) r;
329
330         send_rcom(ls, mh, rc);
331  out:
332         return error;
333 }
334
335 static void receive_rcom_lock(struct dlm_ls *ls, struct dlm_rcom *rc_in)
336 {
337         struct dlm_rcom *rc;
338         struct dlm_mhandle *mh;
339         int error, nodeid = rc_in->rc_header.h_nodeid;
340
341         dlm_recover_master_copy(ls, rc_in);
342
343         error = create_rcom(ls, nodeid, DLM_RCOM_LOCK_REPLY,
344                             sizeof(struct rcom_lock), &rc, &mh);
345         if (error)
346                 return;
347
348         /* We send back the same rcom_lock struct we received, but
349            dlm_recover_master_copy() has filled in rl_remid and rl_result */
350
351         memcpy(rc->rc_buf, rc_in->rc_buf, sizeof(struct rcom_lock));
352         rc->rc_id = rc_in->rc_id;
353
354         send_rcom(ls, mh, rc);
355 }
356
357 static void receive_rcom_lock_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
358 {
359         uint32_t status = dlm_recover_status(ls);
360
361         if (!(status & DLM_RS_DIR)) {
362                 log_debug(ls, "ignoring RCOM_LOCK_REPLY from %u",
363                           rc_in->rc_header.h_nodeid);
364                 return;
365         }
366
367         dlm_recover_process_copy(ls, rc_in);
368 }
369
370 static int send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in)
371 {
372         struct dlm_rcom *rc;
373         struct dlm_mhandle *mh;
374         char *mb;
375         int mb_len = sizeof(struct dlm_rcom);
376
377         mh = dlm_lowcomms_get_buffer(nodeid, mb_len, GFP_KERNEL, &mb);
378         if (!mh)
379                 return -ENOBUFS;
380         memset(mb, 0, mb_len);
381
382         rc = (struct dlm_rcom *) mb;
383
384         rc->rc_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
385         rc->rc_header.h_lockspace = rc_in->rc_header.h_lockspace;
386         rc->rc_header.h_nodeid = dlm_our_nodeid();
387         rc->rc_header.h_length = mb_len;
388         rc->rc_header.h_cmd = DLM_RCOM;
389
390         rc->rc_type = DLM_RCOM_STATUS_REPLY;
391         rc->rc_id = rc_in->rc_id;
392         rc->rc_result = -ESRCH;
393
394         dlm_rcom_out(rc);
395         dlm_lowcomms_commit_buffer(mh);
396
397         return 0;
398 }
399
400 /* Called by dlm_recvd; corresponds to dlm_receive_message() but special
401    recovery-only comms are sent through here. */
402
403 void dlm_receive_rcom(struct dlm_header *hd, int nodeid)
404 {
405         struct dlm_rcom *rc = (struct dlm_rcom *) hd;
406         struct dlm_ls *ls;
407
408         dlm_rcom_in(rc);
409
410         /* If the lockspace doesn't exist then still send a status message
411            back; it's possible that it just doesn't have its global_id yet. */
412
413         ls = dlm_find_lockspace_global(hd->h_lockspace);
414         if (!ls) {
415                 log_print("lockspace %x from %d not found",
416                           hd->h_lockspace, nodeid);
417                 send_ls_not_ready(nodeid, rc);
418                 return;
419         }
420
421         if (dlm_recovery_stopped(ls) && (rc->rc_type != DLM_RCOM_STATUS)) {
422                 log_error(ls, "ignoring recovery message %x from %d",
423                           rc->rc_type, nodeid);
424                 goto out;
425         }
426
427         if (nodeid != rc->rc_header.h_nodeid) {
428                 log_error(ls, "bad rcom nodeid %d from %d",
429                           rc->rc_header.h_nodeid, nodeid);
430                 goto out;
431         }
432
433         switch (rc->rc_type) {
434         case DLM_RCOM_STATUS:
435                 receive_rcom_status(ls, rc);
436                 break;
437
438         case DLM_RCOM_NAMES:
439                 receive_rcom_names(ls, rc);
440                 break;
441
442         case DLM_RCOM_LOOKUP:
443                 receive_rcom_lookup(ls, rc);
444                 break;
445
446         case DLM_RCOM_LOCK:
447                 receive_rcom_lock(ls, rc);
448                 break;
449
450         case DLM_RCOM_STATUS_REPLY:
451                 receive_rcom_status_reply(ls, rc);
452                 break;
453
454         case DLM_RCOM_NAMES_REPLY:
455                 receive_rcom_names_reply(ls, rc);
456                 break;
457
458         case DLM_RCOM_LOOKUP_REPLY:
459                 receive_rcom_lookup_reply(ls, rc);
460                 break;
461
462         case DLM_RCOM_LOCK_REPLY:
463                 receive_rcom_lock_reply(ls, rc);
464                 break;
465
466         default:
467                 DLM_ASSERT(0, printk("rc_type=%x\n", rc->rc_type););
468         }
469  out:
470         dlm_put_lockspace(ls);
471 }
472