xref: /linux/fs/dlm/rcom.c (revision 606d099cdd1080bbb50ea50dc52d98252f8f10a1)
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 static void allow_sync_reply(struct dlm_ls *ls, uint64_t *new_seq)
94 {
95 	spin_lock(&ls->ls_rcom_spin);
96 	*new_seq = ++ls->ls_rcom_seq;
97 	set_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
98 	spin_unlock(&ls->ls_rcom_spin);
99 }
100 
101 static void disallow_sync_reply(struct dlm_ls *ls)
102 {
103 	spin_lock(&ls->ls_rcom_spin);
104 	clear_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
105 	clear_bit(LSFL_RCOM_READY, &ls->ls_flags);
106 	spin_unlock(&ls->ls_rcom_spin);
107 }
108 
109 int dlm_rcom_status(struct dlm_ls *ls, int nodeid)
110 {
111 	struct dlm_rcom *rc;
112 	struct dlm_mhandle *mh;
113 	int error = 0;
114 
115 	ls->ls_recover_nodeid = nodeid;
116 
117 	if (nodeid == dlm_our_nodeid()) {
118 		rc = (struct dlm_rcom *) ls->ls_recover_buf;
119 		rc->rc_result = dlm_recover_status(ls);
120 		goto out;
121 	}
122 
123 	error = create_rcom(ls, nodeid, DLM_RCOM_STATUS, 0, &rc, &mh);
124 	if (error)
125 		goto out;
126 
127 	allow_sync_reply(ls, &rc->rc_id);
128 	memset(ls->ls_recover_buf, 0, dlm_config.buffer_size);
129 
130 	send_rcom(ls, mh, rc);
131 
132 	error = dlm_wait_function(ls, &rcom_response);
133 	disallow_sync_reply(ls);
134 	if (error)
135 		goto out;
136 
137 	rc = (struct dlm_rcom *) ls->ls_recover_buf;
138 
139 	if (rc->rc_result == -ESRCH) {
140 		/* we pretend the remote lockspace exists with 0 status */
141 		log_debug(ls, "remote node %d not ready", nodeid);
142 		rc->rc_result = 0;
143 	} else
144 		error = check_config(ls, (struct rcom_config *) rc->rc_buf,
145 				     nodeid);
146 	/* the caller looks at rc_result for the remote recovery status */
147  out:
148 	return error;
149 }
150 
151 static void receive_rcom_status(struct dlm_ls *ls, struct dlm_rcom *rc_in)
152 {
153 	struct dlm_rcom *rc;
154 	struct dlm_mhandle *mh;
155 	int error, nodeid = rc_in->rc_header.h_nodeid;
156 
157 	error = create_rcom(ls, nodeid, DLM_RCOM_STATUS_REPLY,
158 			    sizeof(struct rcom_config), &rc, &mh);
159 	if (error)
160 		return;
161 	rc->rc_id = rc_in->rc_id;
162 	rc->rc_result = dlm_recover_status(ls);
163 	make_config(ls, (struct rcom_config *) rc->rc_buf);
164 
165 	send_rcom(ls, mh, rc);
166 }
167 
168 static void receive_sync_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
169 {
170 	spin_lock(&ls->ls_rcom_spin);
171 	if (!test_bit(LSFL_RCOM_WAIT, &ls->ls_flags) ||
172 	    rc_in->rc_id != ls->ls_rcom_seq) {
173 		log_debug(ls, "reject reply %d from %d seq %llx expect %llx",
174 			  rc_in->rc_type, rc_in->rc_header.h_nodeid,
175 			  (unsigned long long)rc_in->rc_id,
176 			  (unsigned long long)ls->ls_rcom_seq);
177 		goto out;
178 	}
179 	memcpy(ls->ls_recover_buf, rc_in, rc_in->rc_header.h_length);
180 	set_bit(LSFL_RCOM_READY, &ls->ls_flags);
181 	clear_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
182 	wake_up(&ls->ls_wait_general);
183  out:
184 	spin_unlock(&ls->ls_rcom_spin);
185 }
186 
187 static void receive_rcom_status_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
188 {
189 	receive_sync_reply(ls, rc_in);
190 }
191 
192 int dlm_rcom_names(struct dlm_ls *ls, int nodeid, char *last_name, int last_len)
193 {
194 	struct dlm_rcom *rc;
195 	struct dlm_mhandle *mh;
196 	int error = 0, len = sizeof(struct dlm_rcom);
197 
198 	ls->ls_recover_nodeid = nodeid;
199 
200 	if (nodeid == dlm_our_nodeid()) {
201 		dlm_copy_master_names(ls, last_name, last_len,
202 		                      ls->ls_recover_buf + len,
203 		                      dlm_config.buffer_size - len, nodeid);
204 		goto out;
205 	}
206 
207 	error = create_rcom(ls, nodeid, DLM_RCOM_NAMES, last_len, &rc, &mh);
208 	if (error)
209 		goto out;
210 	memcpy(rc->rc_buf, last_name, last_len);
211 
212 	allow_sync_reply(ls, &rc->rc_id);
213 	memset(ls->ls_recover_buf, 0, dlm_config.buffer_size);
214 
215 	send_rcom(ls, mh, rc);
216 
217 	error = dlm_wait_function(ls, &rcom_response);
218 	disallow_sync_reply(ls);
219  out:
220 	return error;
221 }
222 
223 static void receive_rcom_names(struct dlm_ls *ls, struct dlm_rcom *rc_in)
224 {
225 	struct dlm_rcom *rc;
226 	struct dlm_mhandle *mh;
227 	int error, inlen, outlen;
228 	int nodeid = rc_in->rc_header.h_nodeid;
229 	uint32_t status = dlm_recover_status(ls);
230 
231 	/*
232 	 * We can't run dlm_dir_rebuild_send (which uses ls_nodes) while
233 	 * dlm_recoverd is running ls_nodes_reconfig (which changes ls_nodes).
234 	 * It could only happen in rare cases where we get a late NAMES
235 	 * message from a previous instance of recovery.
236 	 */
237 
238 	if (!(status & DLM_RS_NODES)) {
239 		log_debug(ls, "ignoring RCOM_NAMES from %u", nodeid);
240 		return;
241 	}
242 
243 	nodeid = rc_in->rc_header.h_nodeid;
244 	inlen = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
245 	outlen = dlm_config.buffer_size - sizeof(struct dlm_rcom);
246 
247 	error = create_rcom(ls, nodeid, DLM_RCOM_NAMES_REPLY, outlen, &rc, &mh);
248 	if (error)
249 		return;
250 	rc->rc_id = rc_in->rc_id;
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 
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 = lkb->lkb_ownpid;
312 	rl->rl_lkid = lkb->lkb_id;
313 	rl->rl_exflags = lkb->lkb_exflags;
314 	rl->rl_flags = lkb->lkb_flags;
315 	rl->rl_lvbseq = 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 = lkb->lkb_wait_type;
320 
321 	if (lkb->lkb_bastaddr)
322 		rl->rl_asts |= AST_BAST;
323 	if (lkb->lkb_astaddr)
324 		rl->rl_asts |= AST_COMP;
325 
326 	rl->rl_namelen = 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 static void receive_rcom_lock(struct dlm_ls *ls, struct dlm_rcom *rc_in)
361 {
362 	struct dlm_rcom *rc;
363 	struct dlm_mhandle *mh;
364 	int error, nodeid = rc_in->rc_header.h_nodeid;
365 
366 	dlm_recover_master_copy(ls, rc_in);
367 
368 	error = create_rcom(ls, nodeid, DLM_RCOM_LOCK_REPLY,
369 			    sizeof(struct rcom_lock), &rc, &mh);
370 	if (error)
371 		return;
372 
373 	/* We send back the same rcom_lock struct we received, but
374 	   dlm_recover_master_copy() has filled in rl_remid and rl_result */
375 
376 	memcpy(rc->rc_buf, rc_in->rc_buf, sizeof(struct rcom_lock));
377 	rc->rc_id = rc_in->rc_id;
378 
379 	send_rcom(ls, mh, rc);
380 }
381 
382 static void receive_rcom_lock_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
383 {
384 	uint32_t status = dlm_recover_status(ls);
385 
386 	if (!(status & DLM_RS_DIR)) {
387 		log_debug(ls, "ignoring RCOM_LOCK_REPLY from %u",
388 			  rc_in->rc_header.h_nodeid);
389 		return;
390 	}
391 
392 	dlm_recover_process_copy(ls, rc_in);
393 }
394 
395 static int send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in)
396 {
397 	struct dlm_rcom *rc;
398 	struct rcom_config *rf;
399 	struct dlm_mhandle *mh;
400 	char *mb;
401 	int mb_len = sizeof(struct dlm_rcom) + sizeof(struct rcom_config);
402 
403 	mh = dlm_lowcomms_get_buffer(nodeid, mb_len, GFP_KERNEL, &mb);
404 	if (!mh)
405 		return -ENOBUFS;
406 	memset(mb, 0, mb_len);
407 
408 	rc = (struct dlm_rcom *) mb;
409 
410 	rc->rc_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
411 	rc->rc_header.h_lockspace = rc_in->rc_header.h_lockspace;
412 	rc->rc_header.h_nodeid = dlm_our_nodeid();
413 	rc->rc_header.h_length = mb_len;
414 	rc->rc_header.h_cmd = DLM_RCOM;
415 
416 	rc->rc_type = DLM_RCOM_STATUS_REPLY;
417 	rc->rc_id = rc_in->rc_id;
418 	rc->rc_result = -ESRCH;
419 
420 	rf = (struct rcom_config *) rc->rc_buf;
421 	rf->rf_lvblen = -1;
422 
423 	dlm_rcom_out(rc);
424 	dlm_lowcomms_commit_buffer(mh);
425 
426 	return 0;
427 }
428 
429 /* Called by dlm_recvd; corresponds to dlm_receive_message() but special
430    recovery-only comms are sent through here. */
431 
432 void dlm_receive_rcom(struct dlm_header *hd, int nodeid)
433 {
434 	struct dlm_rcom *rc = (struct dlm_rcom *) hd;
435 	struct dlm_ls *ls;
436 
437 	dlm_rcom_in(rc);
438 
439 	/* If the lockspace doesn't exist then still send a status message
440 	   back; it's possible that it just doesn't have its global_id yet. */
441 
442 	ls = dlm_find_lockspace_global(hd->h_lockspace);
443 	if (!ls) {
444 		log_print("lockspace %x from %d type %x not found",
445 			  hd->h_lockspace, nodeid, rc->rc_type);
446 		if (rc->rc_type == DLM_RCOM_STATUS)
447 			send_ls_not_ready(nodeid, rc);
448 		return;
449 	}
450 
451 	if (dlm_recovery_stopped(ls) && (rc->rc_type != DLM_RCOM_STATUS)) {
452 		log_error(ls, "ignoring recovery message %x from %d",
453 			  rc->rc_type, nodeid);
454 		goto out;
455 	}
456 
457 	if (nodeid != rc->rc_header.h_nodeid) {
458 		log_error(ls, "bad rcom nodeid %d from %d",
459 			  rc->rc_header.h_nodeid, nodeid);
460 		goto out;
461 	}
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 		receive_rcom_lock(ls, rc);
478 		break;
479 
480 	case DLM_RCOM_STATUS_REPLY:
481 		receive_rcom_status_reply(ls, rc);
482 		break;
483 
484 	case DLM_RCOM_NAMES_REPLY:
485 		receive_rcom_names_reply(ls, rc);
486 		break;
487 
488 	case DLM_RCOM_LOOKUP_REPLY:
489 		receive_rcom_lookup_reply(ls, rc);
490 		break;
491 
492 	case DLM_RCOM_LOCK_REPLY:
493 		receive_rcom_lock_reply(ls, rc);
494 		break;
495 
496 	default:
497 		DLM_ASSERT(0, printk("rc_type=%x\n", rc->rc_type););
498 	}
499  out:
500 	dlm_put_lockspace(ls);
501 }
502 
503