xref: /openbmc/linux/fs/dlm/rcom.c (revision 643d1f7f)
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 = 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 int dlm_rcom_names(struct dlm_ls *ls, int nodeid, char *last_name, int last_len)
201 {
202 	struct dlm_rcom *rc;
203 	struct dlm_mhandle *mh;
204 	int error = 0, len = sizeof(struct dlm_rcom);
205 
206 	ls->ls_recover_nodeid = nodeid;
207 
208 	if (nodeid == dlm_our_nodeid()) {
209 		dlm_copy_master_names(ls, last_name, last_len,
210 		                      ls->ls_recover_buf + len,
211 		                      dlm_config.ci_buffer_size - len, nodeid);
212 		goto out;
213 	}
214 
215 	error = create_rcom(ls, nodeid, DLM_RCOM_NAMES, last_len, &rc, &mh);
216 	if (error)
217 		goto out;
218 	memcpy(rc->rc_buf, last_name, last_len);
219 
220 	allow_sync_reply(ls, &rc->rc_id);
221 	memset(ls->ls_recover_buf, 0, dlm_config.ci_buffer_size);
222 
223 	send_rcom(ls, mh, rc);
224 
225 	error = dlm_wait_function(ls, &rcom_response);
226 	disallow_sync_reply(ls);
227  out:
228 	return error;
229 }
230 
231 static void receive_rcom_names(struct dlm_ls *ls, struct dlm_rcom *rc_in)
232 {
233 	struct dlm_rcom *rc;
234 	struct dlm_mhandle *mh;
235 	int error, inlen, outlen, nodeid;
236 
237 	nodeid = rc_in->rc_header.h_nodeid;
238 	inlen = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
239 	outlen = dlm_config.ci_buffer_size - sizeof(struct dlm_rcom);
240 
241 	error = create_rcom(ls, nodeid, DLM_RCOM_NAMES_REPLY, outlen, &rc, &mh);
242 	if (error)
243 		return;
244 	rc->rc_id = rc_in->rc_id;
245 	rc->rc_seq_reply = rc_in->rc_seq;
246 
247 	dlm_copy_master_names(ls, rc_in->rc_buf, inlen, rc->rc_buf, outlen,
248 			      nodeid);
249 	send_rcom(ls, mh, rc);
250 }
251 
252 int dlm_send_rcom_lookup(struct dlm_rsb *r, int dir_nodeid)
253 {
254 	struct dlm_rcom *rc;
255 	struct dlm_mhandle *mh;
256 	struct dlm_ls *ls = r->res_ls;
257 	int error;
258 
259 	error = create_rcom(ls, dir_nodeid, DLM_RCOM_LOOKUP, r->res_length,
260 			    &rc, &mh);
261 	if (error)
262 		goto out;
263 	memcpy(rc->rc_buf, r->res_name, r->res_length);
264 	rc->rc_id = (unsigned long) r;
265 
266 	send_rcom(ls, mh, rc);
267  out:
268 	return error;
269 }
270 
271 static void receive_rcom_lookup(struct dlm_ls *ls, struct dlm_rcom *rc_in)
272 {
273 	struct dlm_rcom *rc;
274 	struct dlm_mhandle *mh;
275 	int error, ret_nodeid, nodeid = rc_in->rc_header.h_nodeid;
276 	int len = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
277 
278 	error = create_rcom(ls, nodeid, DLM_RCOM_LOOKUP_REPLY, 0, &rc, &mh);
279 	if (error)
280 		return;
281 
282 	error = dlm_dir_lookup(ls, nodeid, rc_in->rc_buf, len, &ret_nodeid);
283 	if (error)
284 		ret_nodeid = error;
285 	rc->rc_result = ret_nodeid;
286 	rc->rc_id = rc_in->rc_id;
287 	rc->rc_seq_reply = rc_in->rc_seq;
288 
289 	send_rcom(ls, mh, rc);
290 }
291 
292 static void receive_rcom_lookup_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
293 {
294 	dlm_recover_master_reply(ls, rc_in);
295 }
296 
297 static void pack_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb,
298 			   struct rcom_lock *rl)
299 {
300 	memset(rl, 0, sizeof(*rl));
301 
302 	rl->rl_ownpid = lkb->lkb_ownpid;
303 	rl->rl_lkid = lkb->lkb_id;
304 	rl->rl_exflags = lkb->lkb_exflags;
305 	rl->rl_flags = lkb->lkb_flags;
306 	rl->rl_lvbseq = lkb->lkb_lvbseq;
307 	rl->rl_rqmode = lkb->lkb_rqmode;
308 	rl->rl_grmode = lkb->lkb_grmode;
309 	rl->rl_status = lkb->lkb_status;
310 	rl->rl_wait_type = lkb->lkb_wait_type;
311 
312 	if (lkb->lkb_bastaddr)
313 		rl->rl_asts |= AST_BAST;
314 	if (lkb->lkb_astaddr)
315 		rl->rl_asts |= AST_COMP;
316 
317 	rl->rl_namelen = r->res_length;
318 	memcpy(rl->rl_name, r->res_name, r->res_length);
319 
320 	/* FIXME: might we have an lvb without DLM_LKF_VALBLK set ?
321 	   If so, receive_rcom_lock_args() won't take this copy. */
322 
323 	if (lkb->lkb_lvbptr)
324 		memcpy(rl->rl_lvb, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
325 }
326 
327 int dlm_send_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
328 {
329 	struct dlm_ls *ls = r->res_ls;
330 	struct dlm_rcom *rc;
331 	struct dlm_mhandle *mh;
332 	struct rcom_lock *rl;
333 	int error, len = sizeof(struct rcom_lock);
334 
335 	if (lkb->lkb_lvbptr)
336 		len += ls->ls_lvblen;
337 
338 	error = create_rcom(ls, r->res_nodeid, DLM_RCOM_LOCK, len, &rc, &mh);
339 	if (error)
340 		goto out;
341 
342 	rl = (struct rcom_lock *) rc->rc_buf;
343 	pack_rcom_lock(r, lkb, rl);
344 	rc->rc_id = (unsigned long) r;
345 
346 	send_rcom(ls, mh, rc);
347  out:
348 	return error;
349 }
350 
351 static void receive_rcom_lock(struct dlm_ls *ls, struct dlm_rcom *rc_in)
352 {
353 	struct dlm_rcom *rc;
354 	struct dlm_mhandle *mh;
355 	int error, nodeid = rc_in->rc_header.h_nodeid;
356 
357 	dlm_recover_master_copy(ls, rc_in);
358 
359 	error = create_rcom(ls, nodeid, DLM_RCOM_LOCK_REPLY,
360 			    sizeof(struct rcom_lock), &rc, &mh);
361 	if (error)
362 		return;
363 
364 	/* We send back the same rcom_lock struct we received, but
365 	   dlm_recover_master_copy() has filled in rl_remid and rl_result */
366 
367 	memcpy(rc->rc_buf, rc_in->rc_buf, sizeof(struct rcom_lock));
368 	rc->rc_id = rc_in->rc_id;
369 	rc->rc_seq_reply = rc_in->rc_seq;
370 
371 	send_rcom(ls, mh, rc);
372 }
373 
374 /* If the lockspace doesn't exist then still send a status message
375    back; it's possible that it just doesn't have its global_id yet. */
376 
377 int dlm_send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in)
378 {
379 	struct dlm_rcom *rc;
380 	struct rcom_config *rf;
381 	struct dlm_mhandle *mh;
382 	char *mb;
383 	int mb_len = sizeof(struct dlm_rcom) + sizeof(struct rcom_config);
384 
385 	mh = dlm_lowcomms_get_buffer(nodeid, mb_len, GFP_NOFS, &mb);
386 	if (!mh)
387 		return -ENOBUFS;
388 	memset(mb, 0, mb_len);
389 
390 	rc = (struct dlm_rcom *) mb;
391 
392 	rc->rc_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
393 	rc->rc_header.h_lockspace = rc_in->rc_header.h_lockspace;
394 	rc->rc_header.h_nodeid = dlm_our_nodeid();
395 	rc->rc_header.h_length = mb_len;
396 	rc->rc_header.h_cmd = DLM_RCOM;
397 
398 	rc->rc_type = DLM_RCOM_STATUS_REPLY;
399 	rc->rc_id = rc_in->rc_id;
400 	rc->rc_seq_reply = rc_in->rc_seq;
401 	rc->rc_result = -ESRCH;
402 
403 	rf = (struct rcom_config *) rc->rc_buf;
404 	rf->rf_lvblen = -1;
405 
406 	dlm_rcom_out(rc);
407 	dlm_lowcomms_commit_buffer(mh);
408 
409 	return 0;
410 }
411 
412 static int is_old_reply(struct dlm_ls *ls, struct dlm_rcom *rc)
413 {
414 	uint64_t seq;
415 	int rv = 0;
416 
417 	switch (rc->rc_type) {
418 	case DLM_RCOM_STATUS_REPLY:
419 	case DLM_RCOM_NAMES_REPLY:
420 	case DLM_RCOM_LOOKUP_REPLY:
421 	case DLM_RCOM_LOCK_REPLY:
422 		spin_lock(&ls->ls_recover_lock);
423 		seq = ls->ls_recover_seq;
424 		spin_unlock(&ls->ls_recover_lock);
425 		if (rc->rc_seq_reply != seq) {
426 			log_debug(ls, "ignoring old reply %x from %d "
427 				      "seq_reply %llx expect %llx",
428 				      rc->rc_type, rc->rc_header.h_nodeid,
429 				      (unsigned long long)rc->rc_seq_reply,
430 				      (unsigned long long)seq);
431 			rv = 1;
432 		}
433 	}
434 	return rv;
435 }
436 
437 /* Called by dlm_recv; corresponds to dlm_receive_message() but special
438    recovery-only comms are sent through here. */
439 
440 void dlm_receive_rcom(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
441 {
442 	if (dlm_recovery_stopped(ls) && (rc->rc_type != DLM_RCOM_STATUS)) {
443 		log_debug(ls, "ignoring recovery message %x from %d",
444 			  rc->rc_type, nodeid);
445 		goto out;
446 	}
447 
448 	if (is_old_reply(ls, rc))
449 		goto out;
450 
451 	switch (rc->rc_type) {
452 	case DLM_RCOM_STATUS:
453 		receive_rcom_status(ls, rc);
454 		break;
455 
456 	case DLM_RCOM_NAMES:
457 		receive_rcom_names(ls, rc);
458 		break;
459 
460 	case DLM_RCOM_LOOKUP:
461 		receive_rcom_lookup(ls, rc);
462 		break;
463 
464 	case DLM_RCOM_LOCK:
465 		receive_rcom_lock(ls, rc);
466 		break;
467 
468 	case DLM_RCOM_STATUS_REPLY:
469 		receive_sync_reply(ls, rc);
470 		break;
471 
472 	case DLM_RCOM_NAMES_REPLY:
473 		receive_sync_reply(ls, rc);
474 		break;
475 
476 	case DLM_RCOM_LOOKUP_REPLY:
477 		receive_rcom_lookup_reply(ls, rc);
478 		break;
479 
480 	case DLM_RCOM_LOCK_REPLY:
481 		dlm_recover_process_copy(ls, rc);
482 		break;
483 
484 	default:
485 		log_error(ls, "receive_rcom bad type %d", rc->rc_type);
486 	}
487  out:
488 	return;
489 }
490 
491