1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * dlmconvert.c
4 *
5 * underlying calls for lock conversion
6 *
7 * Copyright (C) 2004 Oracle.  All rights reserved.
8 */
9
10
11#include <linux/module.h>
12#include <linux/fs.h>
13#include <linux/types.h>
14#include <linux/highmem.h>
15#include <linux/init.h>
16#include <linux/sysctl.h>
17#include <linux/random.h>
18#include <linux/blkdev.h>
19#include <linux/socket.h>
20#include <linux/inet.h>
21#include <linux/spinlock.h>
22
23
24#include "../cluster/heartbeat.h"
25#include "../cluster/nodemanager.h"
26#include "../cluster/tcp.h"
27
28#include "dlmapi.h"
29#include "dlmcommon.h"
30
31#include "dlmconvert.h"
32
33#define MLOG_MASK_PREFIX ML_DLM
34#include "../cluster/masklog.h"
35
36/* NOTE: __dlmconvert_master is the only function in here that
37 * needs a spinlock held on entry (res->spinlock) and it is the
38 * only one that holds a lock on exit (res->spinlock).
39 * All other functions in here need no locks and drop all of
40 * the locks that they acquire. */
41static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
42					   struct dlm_lock_resource *res,
43					   struct dlm_lock *lock, int flags,
44					   int type, int *call_ast,
45					   int *kick_thread);
46static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
47					   struct dlm_lock_resource *res,
48					   struct dlm_lock *lock, int flags, int type);
49
50/*
51 * this is only called directly by dlmlock(), and only when the
52 * local node is the owner of the lockres
53 * locking:
54 *   caller needs:  none
55 *   taken:         takes and drops res->spinlock
56 *   held on exit:  none
57 * returns: see __dlmconvert_master
58 */
59enum dlm_status dlmconvert_master(struct dlm_ctxt *dlm,
60				  struct dlm_lock_resource *res,
61				  struct dlm_lock *lock, int flags, int type)
62{
63	int call_ast = 0, kick_thread = 0;
64	enum dlm_status status;
65
66	spin_lock(&res->spinlock);
67	/* we are not in a network handler, this is fine */
68	__dlm_wait_on_lockres(res);
69	__dlm_lockres_reserve_ast(res);
70	res->state |= DLM_LOCK_RES_IN_PROGRESS;
71
72	status = __dlmconvert_master(dlm, res, lock, flags, type,
73				     &call_ast, &kick_thread);
74
75	res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
76	spin_unlock(&res->spinlock);
77	wake_up(&res->wq);
78	if (status != DLM_NORMAL && status != DLM_NOTQUEUED)
79		dlm_error(status);
80
81	/* either queue the ast or release it */
82	if (call_ast)
83		dlm_queue_ast(dlm, lock);
84	else
85		dlm_lockres_release_ast(dlm, res);
86
87	if (kick_thread)
88		dlm_kick_thread(dlm, res);
89
90	return status;
91}
92
93/* performs lock conversion at the lockres master site
94 * locking:
95 *   caller needs:  res->spinlock
96 *   taken:         takes and drops lock->spinlock
97 *   held on exit:  res->spinlock
98 * returns: DLM_NORMAL, DLM_NOTQUEUED, DLM_DENIED
99 *   call_ast: whether ast should be called for this lock
100 *   kick_thread: whether dlm_kick_thread should be called
101 */
102static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
103					   struct dlm_lock_resource *res,
104					   struct dlm_lock *lock, int flags,
105					   int type, int *call_ast,
106					   int *kick_thread)
107{
108	enum dlm_status status = DLM_NORMAL;
109	struct dlm_lock *tmplock=NULL;
110
111	assert_spin_locked(&res->spinlock);
112
113	mlog(0, "type=%d, convert_type=%d, new convert_type=%d\n",
114	     lock->ml.type, lock->ml.convert_type, type);
115
116	spin_lock(&lock->spinlock);
117
118	/* already converting? */
119	if (lock->ml.convert_type != LKM_IVMODE) {
120		mlog(ML_ERROR, "attempted to convert a lock with a lock "
121		     "conversion pending\n");
122		status = DLM_DENIED;
123		goto unlock_exit;
124	}
125
126	/* must be on grant queue to convert */
127	if (!dlm_lock_on_list(&res->granted, lock)) {
128		mlog(ML_ERROR, "attempted to convert a lock not on grant "
129		     "queue\n");
130		status = DLM_DENIED;
131		goto unlock_exit;
132	}
133
134	if (flags & LKM_VALBLK) {
135		switch (lock->ml.type) {
136			case LKM_EXMODE:
137				/* EX + LKM_VALBLK + convert == set lvb */
138				mlog(0, "will set lvb: converting %s->%s\n",
139				     dlm_lock_mode_name(lock->ml.type),
140				     dlm_lock_mode_name(type));
141				lock->lksb->flags |= DLM_LKSB_PUT_LVB;
142				break;
143			case LKM_PRMODE:
144			case LKM_NLMODE:
145				/* refetch if new level is not NL */
146				if (type > LKM_NLMODE) {
147					mlog(0, "will fetch new value into "
148					     "lvb: converting %s->%s\n",
149					     dlm_lock_mode_name(lock->ml.type),
150					     dlm_lock_mode_name(type));
151					lock->lksb->flags |= DLM_LKSB_GET_LVB;
152				} else {
153					mlog(0, "will NOT fetch new value "
154					     "into lvb: converting %s->%s\n",
155					     dlm_lock_mode_name(lock->ml.type),
156					     dlm_lock_mode_name(type));
157					flags &= ~(LKM_VALBLK);
158				}
159				break;
160		}
161	}
162
163
164	/* in-place downconvert? */
165	if (type <= lock->ml.type)
166		goto grant;
167
168	/* upconvert from here on */
169	status = DLM_NORMAL;
170	list_for_each_entry(tmplock, &res->granted, list) {
171		if (tmplock == lock)
172			continue;
173		if (!dlm_lock_compatible(tmplock->ml.type, type))
174			goto switch_queues;
175	}
176
177	list_for_each_entry(tmplock, &res->converting, list) {
178		if (!dlm_lock_compatible(tmplock->ml.type, type))
179			goto switch_queues;
180		/* existing conversion requests take precedence */
181		if (!dlm_lock_compatible(tmplock->ml.convert_type, type))
182			goto switch_queues;
183	}
184
185	/* fall thru to grant */
186
187grant:
188	mlog(0, "res %.*s, granting %s lock\n", res->lockname.len,
189	     res->lockname.name, dlm_lock_mode_name(type));
190	/* immediately grant the new lock type */
191	lock->lksb->status = DLM_NORMAL;
192	if (lock->ml.node == dlm->node_num)
193		mlog(0, "doing in-place convert for nonlocal lock\n");
194	lock->ml.type = type;
195	if (lock->lksb->flags & DLM_LKSB_PUT_LVB)
196		memcpy(res->lvb, lock->lksb->lvb, DLM_LVB_LEN);
197
198	/*
199	 * Move the lock to the tail because it may be the only lock which has
200	 * an invalid lvb.
201	 */
202	list_move_tail(&lock->list, &res->granted);
203
204	status = DLM_NORMAL;
205	*call_ast = 1;
206	goto unlock_exit;
207
208switch_queues:
209	if (flags & LKM_NOQUEUE) {
210		mlog(0, "failed to convert NOQUEUE lock %.*s from "
211		     "%d to %d...\n", res->lockname.len, res->lockname.name,
212		     lock->ml.type, type);
213		status = DLM_NOTQUEUED;
214		goto unlock_exit;
215	}
216	mlog(0, "res %.*s, queueing...\n", res->lockname.len,
217	     res->lockname.name);
218
219	lock->ml.convert_type = type;
220	/* do not alter lock refcount.  switching lists. */
221	list_move_tail(&lock->list, &res->converting);
222
223unlock_exit:
224	spin_unlock(&lock->spinlock);
225	if (status == DLM_DENIED) {
226		__dlm_print_one_lock_resource(res);
227	}
228	if (status == DLM_NORMAL)
229		*kick_thread = 1;
230	return status;
231}
232
233void dlm_revert_pending_convert(struct dlm_lock_resource *res,
234				struct dlm_lock *lock)
235{
236	/* do not alter lock refcount.  switching lists. */
237	list_move_tail(&lock->list, &res->granted);
238	lock->ml.convert_type = LKM_IVMODE;
239	lock->lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
240}
241
242/* messages the master site to do lock conversion
243 * locking:
244 *   caller needs:  none
245 *   taken:         takes and drops res->spinlock, uses DLM_LOCK_RES_IN_PROGRESS
246 *   held on exit:  none
247 * returns: DLM_NORMAL, DLM_RECOVERING, status from remote node
248 */
249enum dlm_status dlmconvert_remote(struct dlm_ctxt *dlm,
250				  struct dlm_lock_resource *res,
251				  struct dlm_lock *lock, int flags, int type)
252{
253	enum dlm_status status;
254
255	mlog(0, "type=%d, convert_type=%d, busy=%d\n", lock->ml.type,
256	     lock->ml.convert_type, res->state & DLM_LOCK_RES_IN_PROGRESS);
257
258	spin_lock(&res->spinlock);
259	if (res->state & DLM_LOCK_RES_RECOVERING) {
260		mlog(0, "bailing out early since res is RECOVERING "
261		     "on secondary queue\n");
262		/* __dlm_print_one_lock_resource(res); */
263		status = DLM_RECOVERING;
264		goto bail;
265	}
266	/* will exit this call with spinlock held */
267	__dlm_wait_on_lockres(res);
268
269	if (lock->ml.convert_type != LKM_IVMODE) {
270		__dlm_print_one_lock_resource(res);
271		mlog(ML_ERROR, "converting a remote lock that is already "
272		     "converting! (cookie=%u:%llu, conv=%d)\n",
273		     dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
274		     dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
275		     lock->ml.convert_type);
276		status = DLM_DENIED;
277		goto bail;
278	}
279
280	if (lock->ml.type == type && lock->ml.convert_type == LKM_IVMODE) {
281		mlog(0, "last convert request returned DLM_RECOVERING, but "
282		     "owner has already queued and sent ast to me. res %.*s, "
283		     "(cookie=%u:%llu, type=%d, conv=%d)\n",
284		     res->lockname.len, res->lockname.name,
285		     dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
286		     dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
287		     lock->ml.type, lock->ml.convert_type);
288		status = DLM_NORMAL;
289		goto bail;
290	}
291
292	res->state |= DLM_LOCK_RES_IN_PROGRESS;
293	/* move lock to local convert queue */
294	/* do not alter lock refcount.  switching lists. */
295	list_move_tail(&lock->list, &res->converting);
296	lock->convert_pending = 1;
297	lock->ml.convert_type = type;
298
299	if (flags & LKM_VALBLK) {
300		if (lock->ml.type == LKM_EXMODE) {
301			flags |= LKM_PUT_LVB;
302			lock->lksb->flags |= DLM_LKSB_PUT_LVB;
303		} else {
304			if (lock->ml.convert_type == LKM_NLMODE)
305				flags &= ~LKM_VALBLK;
306			else {
307				flags |= LKM_GET_LVB;
308				lock->lksb->flags |= DLM_LKSB_GET_LVB;
309			}
310		}
311	}
312	spin_unlock(&res->spinlock);
313
314	/* no locks held here.
315	 * need to wait for a reply as to whether it got queued or not. */
316	status = dlm_send_remote_convert_request(dlm, res, lock, flags, type);
317
318	spin_lock(&res->spinlock);
319	res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
320	/* if it failed, move it back to granted queue.
321	 * if master returns DLM_NORMAL and then down before sending ast,
322	 * it may have already been moved to granted queue, reset to
323	 * DLM_RECOVERING and retry convert */
324	if (status != DLM_NORMAL) {
325		if (status != DLM_NOTQUEUED)
326			dlm_error(status);
327		dlm_revert_pending_convert(res, lock);
328	} else if (!lock->convert_pending) {
329		mlog(0, "%s: res %.*s, owner died and lock has been moved back "
330				"to granted list, retry convert.\n",
331				dlm->name, res->lockname.len, res->lockname.name);
332		status = DLM_RECOVERING;
333	}
334
335	lock->convert_pending = 0;
336bail:
337	spin_unlock(&res->spinlock);
338
339	/* TODO: should this be a wake_one? */
340	/* wake up any IN_PROGRESS waiters */
341	wake_up(&res->wq);
342
343	return status;
344}
345
346/* sends DLM_CONVERT_LOCK_MSG to master site
347 * locking:
348 *   caller needs:  none
349 *   taken:         none
350 *   held on exit:  none
351 * returns: DLM_NOLOCKMGR, status from remote node
352 */
353static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
354					   struct dlm_lock_resource *res,
355					   struct dlm_lock *lock, int flags, int type)
356{
357	struct dlm_convert_lock convert;
358	int tmpret;
359	enum dlm_status ret;
360	int status = 0;
361	struct kvec vec[2];
362	size_t veclen = 1;
363
364	mlog(0, "%.*s\n", res->lockname.len, res->lockname.name);
365
366	memset(&convert, 0, sizeof(struct dlm_convert_lock));
367	convert.node_idx = dlm->node_num;
368	convert.requested_type = type;
369	convert.cookie = lock->ml.cookie;
370	convert.namelen = res->lockname.len;
371	convert.flags = cpu_to_be32(flags);
372	memcpy(convert.name, res->lockname.name, convert.namelen);
373
374	vec[0].iov_len = sizeof(struct dlm_convert_lock);
375	vec[0].iov_base = &convert;
376
377	if (flags & LKM_PUT_LVB) {
378		/* extra data to send if we are updating lvb */
379		vec[1].iov_len = DLM_LVB_LEN;
380		vec[1].iov_base = lock->lksb->lvb;
381		veclen++;
382	}
383
384	tmpret = o2net_send_message_vec(DLM_CONVERT_LOCK_MSG, dlm->key,
385					vec, veclen, res->owner, &status);
386	if (tmpret >= 0) {
387		// successfully sent and received
388		ret = status;  // this is already a dlm_status
389		if (ret == DLM_RECOVERING) {
390			mlog(0, "node %u returned DLM_RECOVERING from convert "
391			     "message!\n", res->owner);
392		} else if (ret == DLM_MIGRATING) {
393			mlog(0, "node %u returned DLM_MIGRATING from convert "
394			     "message!\n", res->owner);
395		} else if (ret == DLM_FORWARD) {
396			mlog(0, "node %u returned DLM_FORWARD from convert "
397			     "message!\n", res->owner);
398		} else if (ret != DLM_NORMAL && ret != DLM_NOTQUEUED)
399			dlm_error(ret);
400	} else {
401		mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
402		     "node %u\n", tmpret, DLM_CONVERT_LOCK_MSG, dlm->key,
403		     res->owner);
404		if (dlm_is_host_down(tmpret)) {
405			/* instead of logging the same network error over
406			 * and over, sleep here and wait for the heartbeat
407			 * to notice the node is dead.  times out after 5s. */
408			dlm_wait_for_node_death(dlm, res->owner,
409						DLM_NODE_DEATH_WAIT_MAX);
410			ret = DLM_RECOVERING;
411			mlog(0, "node %u died so returning DLM_RECOVERING "
412			     "from convert message!\n", res->owner);
413		} else {
414			ret = dlm_err_to_dlm_status(tmpret);
415		}
416	}
417
418	return ret;
419}
420
421/* handler for DLM_CONVERT_LOCK_MSG on master site
422 * locking:
423 *   caller needs:  none
424 *   taken:         takes and drop res->spinlock
425 *   held on exit:  none
426 * returns: DLM_NORMAL, DLM_IVLOCKID, DLM_BADARGS,
427 *          status from __dlmconvert_master
428 */
429int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data,
430			     void **ret_data)
431{
432	struct dlm_ctxt *dlm = data;
433	struct dlm_convert_lock *cnv = (struct dlm_convert_lock *)msg->buf;
434	struct dlm_lock_resource *res = NULL;
435	struct dlm_lock *lock = NULL;
436	struct dlm_lock *tmp_lock;
437	struct dlm_lockstatus *lksb;
438	enum dlm_status status = DLM_NORMAL;
439	u32 flags;
440	int call_ast = 0, kick_thread = 0, ast_reserved = 0, wake = 0;
441
442	if (!dlm_grab(dlm)) {
443		dlm_error(DLM_REJECTED);
444		return DLM_REJECTED;
445	}
446
447	mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
448			"Domain %s not fully joined!\n", dlm->name);
449
450	if (cnv->namelen > DLM_LOCKID_NAME_MAX) {
451		status = DLM_IVBUFLEN;
452		dlm_error(status);
453		goto leave;
454	}
455
456	flags = be32_to_cpu(cnv->flags);
457
458	if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) ==
459	     (LKM_PUT_LVB|LKM_GET_LVB)) {
460		mlog(ML_ERROR, "both PUT and GET lvb specified\n");
461		status = DLM_BADARGS;
462		goto leave;
463	}
464
465	mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" :
466	     (flags & LKM_GET_LVB ? "get lvb" : "none"));
467
468	status = DLM_IVLOCKID;
469	res = dlm_lookup_lockres(dlm, cnv->name, cnv->namelen);
470	if (!res) {
471		dlm_error(status);
472		goto leave;
473	}
474
475	spin_lock(&res->spinlock);
476	status = __dlm_lockres_state_to_status(res);
477	if (status != DLM_NORMAL) {
478		spin_unlock(&res->spinlock);
479		dlm_error(status);
480		goto leave;
481	}
482	list_for_each_entry(tmp_lock, &res->granted, list) {
483		if (tmp_lock->ml.cookie == cnv->cookie &&
484		    tmp_lock->ml.node == cnv->node_idx) {
485			lock = tmp_lock;
486			dlm_lock_get(lock);
487			break;
488		}
489	}
490	spin_unlock(&res->spinlock);
491	if (!lock) {
492		status = DLM_IVLOCKID;
493		mlog(ML_ERROR, "did not find lock to convert on grant queue! "
494			       "cookie=%u:%llu\n",
495		     dlm_get_lock_cookie_node(be64_to_cpu(cnv->cookie)),
496		     dlm_get_lock_cookie_seq(be64_to_cpu(cnv->cookie)));
497		dlm_print_one_lock_resource(res);
498		goto leave;
499	}
500
501	/* found the lock */
502	lksb = lock->lksb;
503
504	/* see if caller needed to get/put lvb */
505	if (flags & LKM_PUT_LVB) {
506		BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
507		lksb->flags |= DLM_LKSB_PUT_LVB;
508		memcpy(&lksb->lvb[0], &cnv->lvb[0], DLM_LVB_LEN);
509	} else if (flags & LKM_GET_LVB) {
510		BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
511		lksb->flags |= DLM_LKSB_GET_LVB;
512	}
513
514	spin_lock(&res->spinlock);
515	status = __dlm_lockres_state_to_status(res);
516	if (status == DLM_NORMAL) {
517		__dlm_lockres_reserve_ast(res);
518		ast_reserved = 1;
519		res->state |= DLM_LOCK_RES_IN_PROGRESS;
520		status = __dlmconvert_master(dlm, res, lock, flags,
521					     cnv->requested_type,
522					     &call_ast, &kick_thread);
523		res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
524		wake = 1;
525	}
526	spin_unlock(&res->spinlock);
527	if (wake)
528		wake_up(&res->wq);
529
530	if (status != DLM_NORMAL) {
531		if (status != DLM_NOTQUEUED)
532			dlm_error(status);
533		lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
534	}
535
536leave:
537	if (lock)
538		dlm_lock_put(lock);
539
540	/* either queue the ast or release it, if reserved */
541	if (call_ast)
542		dlm_queue_ast(dlm, lock);
543	else if (ast_reserved)
544		dlm_lockres_release_ast(dlm, res);
545
546	if (kick_thread)
547		dlm_kick_thread(dlm, res);
548
549	if (res)
550		dlm_lockres_put(res);
551
552	dlm_put(dlm);
553
554	return status;
555}
556