xref: /linux/fs/dlm/rcom.c (revision ed3174d93c342b8b2eeba6bbd124707d55304a7b)
1 /******************************************************************************
2 *******************************************************************************
3 **
4 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
5 **  Copyright (C) 2005-2008 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 = cpu_to_le32(ls->ls_lvblen);
82 	rf->rf_lsflags = cpu_to_le32(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 	size_t conf_size = sizeof(struct dlm_rcom) + sizeof(struct rcom_config);
89 
90 	if ((rc->rc_header.h_version & 0xFFFF0000) != DLM_HEADER_MAJOR) {
91 		log_error(ls, "version mismatch: %x nodeid %d: %x",
92 			  DLM_HEADER_MAJOR | DLM_HEADER_MINOR, nodeid,
93 			  rc->rc_header.h_version);
94 		return -EPROTO;
95 	}
96 
97 	if (rc->rc_header.h_length < conf_size) {
98 		log_error(ls, "config too short: %d nodeid %d",
99 			  rc->rc_header.h_length, nodeid);
100 		return -EPROTO;
101 	}
102 
103 	if (le32_to_cpu(rf->rf_lvblen) != ls->ls_lvblen ||
104 	    le32_to_cpu(rf->rf_lsflags) != ls->ls_exflags) {
105 		log_error(ls, "config mismatch: %d,%x nodeid %d: %d,%x",
106 			  ls->ls_lvblen, ls->ls_exflags, nodeid,
107 			  le32_to_cpu(rf->rf_lvblen),
108 			  le32_to_cpu(rf->rf_lsflags));
109 		return -EPROTO;
110 	}
111 	return 0;
112 }
113 
114 static void allow_sync_reply(struct dlm_ls *ls, uint64_t *new_seq)
115 {
116 	spin_lock(&ls->ls_rcom_spin);
117 	*new_seq = ++ls->ls_rcom_seq;
118 	set_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
119 	spin_unlock(&ls->ls_rcom_spin);
120 }
121 
122 static void disallow_sync_reply(struct dlm_ls *ls)
123 {
124 	spin_lock(&ls->ls_rcom_spin);
125 	clear_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
126 	clear_bit(LSFL_RCOM_READY, &ls->ls_flags);
127 	spin_unlock(&ls->ls_rcom_spin);
128 }
129 
130 int dlm_rcom_status(struct dlm_ls *ls, int nodeid)
131 {
132 	struct dlm_rcom *rc;
133 	struct dlm_mhandle *mh;
134 	int error = 0;
135 
136 	ls->ls_recover_nodeid = nodeid;
137 
138 	if (nodeid == dlm_our_nodeid()) {
139 		rc = ls->ls_recover_buf;
140 		rc->rc_result = dlm_recover_status(ls);
141 		goto out;
142 	}
143 
144 	error = create_rcom(ls, nodeid, DLM_RCOM_STATUS, 0, &rc, &mh);
145 	if (error)
146 		goto out;
147 
148 	allow_sync_reply(ls, &rc->rc_id);
149 	memset(ls->ls_recover_buf, 0, dlm_config.ci_buffer_size);
150 
151 	send_rcom(ls, mh, rc);
152 
153 	error = dlm_wait_function(ls, &rcom_response);
154 	disallow_sync_reply(ls);
155 	if (error)
156 		goto out;
157 
158 	rc = ls->ls_recover_buf;
159 
160 	if (rc->rc_result == -ESRCH) {
161 		/* we pretend the remote lockspace exists with 0 status */
162 		log_debug(ls, "remote node %d not ready", nodeid);
163 		rc->rc_result = 0;
164 	} else
165 		error = check_config(ls, rc, nodeid);
166 	/* the caller looks at rc_result for the remote recovery status */
167  out:
168 	return error;
169 }
170 
171 static void receive_rcom_status(struct dlm_ls *ls, struct dlm_rcom *rc_in)
172 {
173 	struct dlm_rcom *rc;
174 	struct dlm_mhandle *mh;
175 	int error, nodeid = rc_in->rc_header.h_nodeid;
176 
177 	error = create_rcom(ls, nodeid, DLM_RCOM_STATUS_REPLY,
178 			    sizeof(struct rcom_config), &rc, &mh);
179 	if (error)
180 		return;
181 	rc->rc_id = rc_in->rc_id;
182 	rc->rc_seq_reply = rc_in->rc_seq;
183 	rc->rc_result = dlm_recover_status(ls);
184 	make_config(ls, (struct rcom_config *) rc->rc_buf);
185 
186 	send_rcom(ls, mh, rc);
187 }
188 
189 static void receive_sync_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
190 {
191 	spin_lock(&ls->ls_rcom_spin);
192 	if (!test_bit(LSFL_RCOM_WAIT, &ls->ls_flags) ||
193 	    rc_in->rc_id != ls->ls_rcom_seq) {
194 		log_debug(ls, "reject reply %d from %d seq %llx expect %llx",
195 			  rc_in->rc_type, rc_in->rc_header.h_nodeid,
196 			  (unsigned long long)rc_in->rc_id,
197 			  (unsigned long long)ls->ls_rcom_seq);
198 		goto out;
199 	}
200 	memcpy(ls->ls_recover_buf, rc_in, rc_in->rc_header.h_length);
201 	set_bit(LSFL_RCOM_READY, &ls->ls_flags);
202 	clear_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
203 	wake_up(&ls->ls_wait_general);
204  out:
205 	spin_unlock(&ls->ls_rcom_spin);
206 }
207 
208 int dlm_rcom_names(struct dlm_ls *ls, int nodeid, char *last_name, int last_len)
209 {
210 	struct dlm_rcom *rc;
211 	struct dlm_mhandle *mh;
212 	int error = 0;
213 	int max_size = dlm_config.ci_buffer_size - sizeof(struct dlm_rcom);
214 
215 	ls->ls_recover_nodeid = nodeid;
216 
217 	if (nodeid == dlm_our_nodeid()) {
218 		dlm_copy_master_names(ls, last_name, last_len,
219 		                      ls->ls_recover_buf->rc_buf,
220 		                      max_size, nodeid);
221 		goto out;
222 	}
223 
224 	error = create_rcom(ls, nodeid, DLM_RCOM_NAMES, last_len, &rc, &mh);
225 	if (error)
226 		goto out;
227 	memcpy(rc->rc_buf, last_name, last_len);
228 
229 	allow_sync_reply(ls, &rc->rc_id);
230 	memset(ls->ls_recover_buf, 0, dlm_config.ci_buffer_size);
231 
232 	send_rcom(ls, mh, rc);
233 
234 	error = dlm_wait_function(ls, &rcom_response);
235 	disallow_sync_reply(ls);
236  out:
237 	return error;
238 }
239 
240 static void receive_rcom_names(struct dlm_ls *ls, struct dlm_rcom *rc_in)
241 {
242 	struct dlm_rcom *rc;
243 	struct dlm_mhandle *mh;
244 	int error, inlen, outlen, nodeid;
245 
246 	nodeid = rc_in->rc_header.h_nodeid;
247 	inlen = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
248 	outlen = dlm_config.ci_buffer_size - sizeof(struct dlm_rcom);
249 
250 	error = create_rcom(ls, nodeid, DLM_RCOM_NAMES_REPLY, outlen, &rc, &mh);
251 	if (error)
252 		return;
253 	rc->rc_id = rc_in->rc_id;
254 	rc->rc_seq_reply = rc_in->rc_seq;
255 
256 	dlm_copy_master_names(ls, rc_in->rc_buf, inlen, rc->rc_buf, outlen,
257 			      nodeid);
258 	send_rcom(ls, mh, rc);
259 }
260 
261 int dlm_send_rcom_lookup(struct dlm_rsb *r, int dir_nodeid)
262 {
263 	struct dlm_rcom *rc;
264 	struct dlm_mhandle *mh;
265 	struct dlm_ls *ls = r->res_ls;
266 	int error;
267 
268 	error = create_rcom(ls, dir_nodeid, DLM_RCOM_LOOKUP, r->res_length,
269 			    &rc, &mh);
270 	if (error)
271 		goto out;
272 	memcpy(rc->rc_buf, r->res_name, r->res_length);
273 	rc->rc_id = (unsigned long) r;
274 
275 	send_rcom(ls, mh, rc);
276  out:
277 	return error;
278 }
279 
280 static void receive_rcom_lookup(struct dlm_ls *ls, struct dlm_rcom *rc_in)
281 {
282 	struct dlm_rcom *rc;
283 	struct dlm_mhandle *mh;
284 	int error, ret_nodeid, nodeid = rc_in->rc_header.h_nodeid;
285 	int len = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
286 
287 	error = create_rcom(ls, nodeid, DLM_RCOM_LOOKUP_REPLY, 0, &rc, &mh);
288 	if (error)
289 		return;
290 
291 	error = dlm_dir_lookup(ls, nodeid, rc_in->rc_buf, len, &ret_nodeid);
292 	if (error)
293 		ret_nodeid = error;
294 	rc->rc_result = ret_nodeid;
295 	rc->rc_id = rc_in->rc_id;
296 	rc->rc_seq_reply = rc_in->rc_seq;
297 
298 	send_rcom(ls, mh, rc);
299 }
300 
301 static void receive_rcom_lookup_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
302 {
303 	dlm_recover_master_reply(ls, rc_in);
304 }
305 
306 static void pack_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb,
307 			   struct rcom_lock *rl)
308 {
309 	memset(rl, 0, sizeof(*rl));
310 
311 	rl->rl_ownpid = cpu_to_le32(lkb->lkb_ownpid);
312 	rl->rl_lkid = cpu_to_le32(lkb->lkb_id);
313 	rl->rl_exflags = cpu_to_le32(lkb->lkb_exflags);
314 	rl->rl_flags = cpu_to_le32(lkb->lkb_flags);
315 	rl->rl_lvbseq = cpu_to_le32(lkb->lkb_lvbseq);
316 	rl->rl_rqmode = lkb->lkb_rqmode;
317 	rl->rl_grmode = lkb->lkb_grmode;
318 	rl->rl_status = lkb->lkb_status;
319 	rl->rl_wait_type = cpu_to_le16(lkb->lkb_wait_type);
320 
321 	if (lkb->lkb_bastfn)
322 		rl->rl_asts |= AST_BAST;
323 	if (lkb->lkb_astfn)
324 		rl->rl_asts |= AST_COMP;
325 
326 	rl->rl_namelen = cpu_to_le16(r->res_length);
327 	memcpy(rl->rl_name, r->res_name, r->res_length);
328 
329 	/* FIXME: might we have an lvb without DLM_LKF_VALBLK set ?
330 	   If so, receive_rcom_lock_args() won't take this copy. */
331 
332 	if (lkb->lkb_lvbptr)
333 		memcpy(rl->rl_lvb, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
334 }
335 
336 int dlm_send_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
337 {
338 	struct dlm_ls *ls = r->res_ls;
339 	struct dlm_rcom *rc;
340 	struct dlm_mhandle *mh;
341 	struct rcom_lock *rl;
342 	int error, len = sizeof(struct rcom_lock);
343 
344 	if (lkb->lkb_lvbptr)
345 		len += ls->ls_lvblen;
346 
347 	error = create_rcom(ls, r->res_nodeid, DLM_RCOM_LOCK, len, &rc, &mh);
348 	if (error)
349 		goto out;
350 
351 	rl = (struct rcom_lock *) rc->rc_buf;
352 	pack_rcom_lock(r, lkb, rl);
353 	rc->rc_id = (unsigned long) r;
354 
355 	send_rcom(ls, mh, rc);
356  out:
357 	return error;
358 }
359 
360 /* needs at least dlm_rcom + rcom_lock */
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 /* If the lockspace doesn't exist then still send a status message
385    back; it's possible that it just doesn't have its global_id yet. */
386 
387 int dlm_send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in)
388 {
389 	struct dlm_rcom *rc;
390 	struct rcom_config *rf;
391 	struct dlm_mhandle *mh;
392 	char *mb;
393 	int mb_len = sizeof(struct dlm_rcom) + sizeof(struct rcom_config);
394 
395 	mh = dlm_lowcomms_get_buffer(nodeid, mb_len, GFP_NOFS, &mb);
396 	if (!mh)
397 		return -ENOBUFS;
398 	memset(mb, 0, mb_len);
399 
400 	rc = (struct dlm_rcom *) mb;
401 
402 	rc->rc_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
403 	rc->rc_header.h_lockspace = rc_in->rc_header.h_lockspace;
404 	rc->rc_header.h_nodeid = dlm_our_nodeid();
405 	rc->rc_header.h_length = mb_len;
406 	rc->rc_header.h_cmd = DLM_RCOM;
407 
408 	rc->rc_type = DLM_RCOM_STATUS_REPLY;
409 	rc->rc_id = rc_in->rc_id;
410 	rc->rc_seq_reply = rc_in->rc_seq;
411 	rc->rc_result = -ESRCH;
412 
413 	rf = (struct rcom_config *) rc->rc_buf;
414 	rf->rf_lvblen = cpu_to_le32(~0U);
415 
416 	dlm_rcom_out(rc);
417 	dlm_lowcomms_commit_buffer(mh);
418 
419 	return 0;
420 }
421 
422 static int is_old_reply(struct dlm_ls *ls, struct dlm_rcom *rc)
423 {
424 	uint64_t seq;
425 	int rv = 0;
426 
427 	switch (rc->rc_type) {
428 	case DLM_RCOM_STATUS_REPLY:
429 	case DLM_RCOM_NAMES_REPLY:
430 	case DLM_RCOM_LOOKUP_REPLY:
431 	case DLM_RCOM_LOCK_REPLY:
432 		spin_lock(&ls->ls_recover_lock);
433 		seq = ls->ls_recover_seq;
434 		spin_unlock(&ls->ls_recover_lock);
435 		if (rc->rc_seq_reply != seq) {
436 			log_debug(ls, "ignoring old reply %x from %d "
437 				      "seq_reply %llx expect %llx",
438 				      rc->rc_type, rc->rc_header.h_nodeid,
439 				      (unsigned long long)rc->rc_seq_reply,
440 				      (unsigned long long)seq);
441 			rv = 1;
442 		}
443 	}
444 	return rv;
445 }
446 
447 /* Called by dlm_recv; corresponds to dlm_receive_message() but special
448    recovery-only comms are sent through here. */
449 
450 void dlm_receive_rcom(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
451 {
452 	int lock_size = sizeof(struct dlm_rcom) + sizeof(struct rcom_lock);
453 
454 	if (dlm_recovery_stopped(ls) && (rc->rc_type != DLM_RCOM_STATUS)) {
455 		log_debug(ls, "ignoring recovery message %x from %d",
456 			  rc->rc_type, nodeid);
457 		goto out;
458 	}
459 
460 	if (is_old_reply(ls, rc))
461 		goto out;
462 
463 	switch (rc->rc_type) {
464 	case DLM_RCOM_STATUS:
465 		receive_rcom_status(ls, rc);
466 		break;
467 
468 	case DLM_RCOM_NAMES:
469 		receive_rcom_names(ls, rc);
470 		break;
471 
472 	case DLM_RCOM_LOOKUP:
473 		receive_rcom_lookup(ls, rc);
474 		break;
475 
476 	case DLM_RCOM_LOCK:
477 		if (rc->rc_header.h_length < lock_size)
478 			goto Eshort;
479 		receive_rcom_lock(ls, rc);
480 		break;
481 
482 	case DLM_RCOM_STATUS_REPLY:
483 		receive_sync_reply(ls, rc);
484 		break;
485 
486 	case DLM_RCOM_NAMES_REPLY:
487 		receive_sync_reply(ls, rc);
488 		break;
489 
490 	case DLM_RCOM_LOOKUP_REPLY:
491 		receive_rcom_lookup_reply(ls, rc);
492 		break;
493 
494 	case DLM_RCOM_LOCK_REPLY:
495 		if (rc->rc_header.h_length < lock_size)
496 			goto Eshort;
497 		dlm_recover_process_copy(ls, rc);
498 		break;
499 
500 	default:
501 		log_error(ls, "receive_rcom bad type %d", rc->rc_type);
502 	}
503 out:
504 	return;
505 Eshort:
506 	log_error(ls, "recovery message %x from %d is too short",
507 			  rc->rc_type, nodeid);
508 }
509 
510