1// SPDX-License-Identifier: GPL-2.0-or-later
2/* -*- mode: c; c-basic-offset: 8; -*-
3 * vim: noexpandtab sw=8 ts=8 sts=0:
4 *
5 * dlmconvert.c
6 *
7 * underlying calls for lock conversion
8 *
9 * Copyright (C) 2004 Oracle.  All rights reserved.
10 */
11
12
13#include <linux/module.h>
14#include <linux/fs.h>
15#include <linux/types.h>
16#include <linux/highmem.h>
17#include <linux/init.h>
18#include <linux/sysctl.h>
19#include <linux/random.h>
20#include <linux/blkdev.h>
21#include <linux/socket.h>
22#include <linux/inet.h>
23#include <linux/spinlock.h>
24
25
26#include "../cluster/heartbeat.h"
27#include "../cluster/nodemanager.h"
28#include "../cluster/tcp.h"
29
30#include "dlmapi.h"
31#include "dlmcommon.h"
32
33#include "dlmconvert.h"
34
35#define MLOG_MASK_PREFIX ML_DLM
36#include "../cluster/masklog.h"
37
38/* NOTE: __dlmconvert_master is the only function in here that
39 * needs a spinlock held on entry (res->spinlock) and it is the
40 * only one that holds a lock on exit (res->spinlock).
41 * All other functions in here need no locks and drop all of
42 * the locks that they acquire. */
43static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
44					   struct dlm_lock_resource *res,
45					   struct dlm_lock *lock, int flags,
46					   int type, int *call_ast,
47					   int *kick_thread);
48static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
49					   struct dlm_lock_resource *res,
50					   struct dlm_lock *lock, int flags, int type);
51
52/*
53 * this is only called directly by dlmlock(), and only when the
54 * local node is the owner of the lockres
55 * locking:
56 *   caller needs:  none
57 *   taken:         takes and drops res->spinlock
58 *   held on exit:  none
59 * returns: see __dlmconvert_master
60 */
61enum dlm_status dlmconvert_master(struct dlm_ctxt *dlm,
62				  struct dlm_lock_resource *res,
63				  struct dlm_lock *lock, int flags, int type)
64{
65	int call_ast = 0, kick_thread = 0;
66	enum dlm_status status;
67
68	spin_lock(&res->spinlock);
69	/* we are not in a network handler, this is fine */
70	__dlm_wait_on_lockres(res);
71	__dlm_lockres_reserve_ast(res);
72	res->state |= DLM_LOCK_RES_IN_PROGRESS;
73
74	status = __dlmconvert_master(dlm, res, lock, flags, type,
75				     &call_ast, &kick_thread);
76
77	res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
78	spin_unlock(&res->spinlock);
79	wake_up(&res->wq);
80	if (status != DLM_NORMAL && status != DLM_NOTQUEUED)
81		dlm_error(status);
82
83	/* either queue the ast or release it */
84	if (call_ast)
85		dlm_queue_ast(dlm, lock);
86	else
87		dlm_lockres_release_ast(dlm, res);
88
89	if (kick_thread)
90		dlm_kick_thread(dlm, res);
91
92	return status;
93}
94
95/* performs lock conversion at the lockres master site
96 * locking:
97 *   caller needs:  res->spinlock
98 *   taken:         takes and drops lock->spinlock
99 *   held on exit:  res->spinlock
100 * returns: DLM_NORMAL, DLM_NOTQUEUED, DLM_DENIED
101 *   call_ast: whether ast should be called for this lock
102 *   kick_thread: whether dlm_kick_thread should be called
103 */
104static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
105					   struct dlm_lock_resource *res,
106					   struct dlm_lock *lock, int flags,
107					   int type, int *call_ast,
108					   int *kick_thread)
109{
110	enum dlm_status status = DLM_NORMAL;
111	struct dlm_lock *tmplock=NULL;
112
113	assert_spin_locked(&res->spinlock);
114
115	mlog(0, "type=%d, convert_type=%d, new convert_type=%d\n",
116	     lock->ml.type, lock->ml.convert_type, type);
117
118	spin_lock(&lock->spinlock);
119
120	/* already converting? */
121	if (lock->ml.convert_type != LKM_IVMODE) {
122		mlog(ML_ERROR, "attempted to convert a lock with a lock "
123		     "conversion pending\n");
124		status = DLM_DENIED;
125		goto unlock_exit;
126	}
127
128	/* must be on grant queue to convert */
129	if (!dlm_lock_on_list(&res->granted, lock)) {
130		mlog(ML_ERROR, "attempted to convert a lock not on grant "
131		     "queue\n");
132		status = DLM_DENIED;
133		goto unlock_exit;
134	}
135
136	if (flags & LKM_VALBLK) {
137		switch (lock->ml.type) {
138			case LKM_EXMODE:
139				/* EX + LKM_VALBLK + convert == set lvb */
140				mlog(0, "will set lvb: converting %s->%s\n",
141				     dlm_lock_mode_name(lock->ml.type),
142				     dlm_lock_mode_name(type));
143				lock->lksb->flags |= DLM_LKSB_PUT_LVB;
144				break;
145			case LKM_PRMODE:
146			case LKM_NLMODE:
147				/* refetch if new level is not NL */
148				if (type > LKM_NLMODE) {
149					mlog(0, "will fetch new value into "
150					     "lvb: converting %s->%s\n",
151					     dlm_lock_mode_name(lock->ml.type),
152					     dlm_lock_mode_name(type));
153					lock->lksb->flags |= DLM_LKSB_GET_LVB;
154				} else {
155					mlog(0, "will NOT fetch new value "
156					     "into lvb: converting %s->%s\n",
157					     dlm_lock_mode_name(lock->ml.type),
158					     dlm_lock_mode_name(type));
159					flags &= ~(LKM_VALBLK);
160				}
161				break;
162		}
163	}
164
165
166	/* in-place downconvert? */
167	if (type <= lock->ml.type)
168		goto grant;
169
170	/* upconvert from here on */
171	status = DLM_NORMAL;
172	list_for_each_entry(tmplock, &res->granted, list) {
173		if (tmplock == lock)
174			continue;
175		if (!dlm_lock_compatible(tmplock->ml.type, type))
176			goto switch_queues;
177	}
178
179	list_for_each_entry(tmplock, &res->converting, list) {
180		if (!dlm_lock_compatible(tmplock->ml.type, type))
181			goto switch_queues;
182		/* existing conversion requests take precedence */
183		if (!dlm_lock_compatible(tmplock->ml.convert_type, type))
184			goto switch_queues;
185	}
186
187	/* fall thru to grant */
188
189grant:
190	mlog(0, "res %.*s, granting %s lock\n", res->lockname.len,
191	     res->lockname.name, dlm_lock_mode_name(type));
192	/* immediately grant the new lock type */
193	lock->lksb->status = DLM_NORMAL;
194	if (lock->ml.node == dlm->node_num)
195		mlog(0, "doing in-place convert for nonlocal lock\n");
196	lock->ml.type = type;
197	if (lock->lksb->flags & DLM_LKSB_PUT_LVB)
198		memcpy(res->lvb, lock->lksb->lvb, DLM_LVB_LEN);
199
200	/*
201	 * Move the lock to the tail because it may be the only lock which has
202	 * an invalid lvb.
203	 */
204	list_move_tail(&lock->list, &res->granted);
205
206	status = DLM_NORMAL;
207	*call_ast = 1;
208	goto unlock_exit;
209
210switch_queues:
211	if (flags & LKM_NOQUEUE) {
212		mlog(0, "failed to convert NOQUEUE lock %.*s from "
213		     "%d to %d...\n", res->lockname.len, res->lockname.name,
214		     lock->ml.type, type);
215		status = DLM_NOTQUEUED;
216		goto unlock_exit;
217	}
218	mlog(0, "res %.*s, queueing...\n", res->lockname.len,
219	     res->lockname.name);
220
221	lock->ml.convert_type = type;
222	/* do not alter lock refcount.  switching lists. */
223	list_move_tail(&lock->list, &res->converting);
224
225unlock_exit:
226	spin_unlock(&lock->spinlock);
227	if (status == DLM_DENIED) {
228		__dlm_print_one_lock_resource(res);
229	}
230	if (status == DLM_NORMAL)
231		*kick_thread = 1;
232	return status;
233}
234
235void dlm_revert_pending_convert(struct dlm_lock_resource *res,
236				struct dlm_lock *lock)
237{
238	/* do not alter lock refcount.  switching lists. */
239	list_move_tail(&lock->list, &res->granted);
240	lock->ml.convert_type = LKM_IVMODE;
241	lock->lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
242}
243
244/* messages the master site to do lock conversion
245 * locking:
246 *   caller needs:  none
247 *   taken:         takes and drops res->spinlock, uses DLM_LOCK_RES_IN_PROGRESS
248 *   held on exit:  none
249 * returns: DLM_NORMAL, DLM_RECOVERING, status from remote node
250 */
251enum dlm_status dlmconvert_remote(struct dlm_ctxt *dlm,
252				  struct dlm_lock_resource *res,
253				  struct dlm_lock *lock, int flags, int type)
254{
255	enum dlm_status status;
256
257	mlog(0, "type=%d, convert_type=%d, busy=%d\n", lock->ml.type,
258	     lock->ml.convert_type, res->state & DLM_LOCK_RES_IN_PROGRESS);
259
260	spin_lock(&res->spinlock);
261	if (res->state & DLM_LOCK_RES_RECOVERING) {
262		mlog(0, "bailing out early since res is RECOVERING "
263		     "on secondary queue\n");
264		/* __dlm_print_one_lock_resource(res); */
265		status = DLM_RECOVERING;
266		goto bail;
267	}
268	/* will exit this call with spinlock held */
269	__dlm_wait_on_lockres(res);
270
271	if (lock->ml.convert_type != LKM_IVMODE) {
272		__dlm_print_one_lock_resource(res);
273		mlog(ML_ERROR, "converting a remote lock that is already "
274		     "converting! (cookie=%u:%llu, conv=%d)\n",
275		     dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
276		     dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
277		     lock->ml.convert_type);
278		status = DLM_DENIED;
279		goto bail;
280	}
281
282	if (lock->ml.type == type && lock->ml.convert_type == LKM_IVMODE) {
283		mlog(0, "last convert request returned DLM_RECOVERING, but "
284		     "owner has already queued and sent ast to me. res %.*s, "
285		     "(cookie=%u:%llu, type=%d, conv=%d)\n",
286		     res->lockname.len, res->lockname.name,
287		     dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
288		     dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
289		     lock->ml.type, lock->ml.convert_type);
290		status = DLM_NORMAL;
291		goto bail;
292	}
293
294	res->state |= DLM_LOCK_RES_IN_PROGRESS;
295	/* move lock to local convert queue */
296	/* do not alter lock refcount.  switching lists. */
297	list_move_tail(&lock->list, &res->converting);
298	lock->convert_pending = 1;
299	lock->ml.convert_type = type;
300
301	if (flags & LKM_VALBLK) {
302		if (lock->ml.type == LKM_EXMODE) {
303			flags |= LKM_PUT_LVB;
304			lock->lksb->flags |= DLM_LKSB_PUT_LVB;
305		} else {
306			if (lock->ml.convert_type == LKM_NLMODE)
307				flags &= ~LKM_VALBLK;
308			else {
309				flags |= LKM_GET_LVB;
310				lock->lksb->flags |= DLM_LKSB_GET_LVB;
311			}
312		}
313	}
314	spin_unlock(&res->spinlock);
315
316	/* no locks held here.
317	 * need to wait for a reply as to whether it got queued or not. */
318	status = dlm_send_remote_convert_request(dlm, res, lock, flags, type);
319
320	spin_lock(&res->spinlock);
321	res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
322	/* if it failed, move it back to granted queue.
323	 * if master returns DLM_NORMAL and then down before sending ast,
324	 * it may have already been moved to granted queue, reset to
325	 * DLM_RECOVERING and retry convert */
326	if (status != DLM_NORMAL) {
327		if (status != DLM_NOTQUEUED)
328			dlm_error(status);
329		dlm_revert_pending_convert(res, lock);
330	} else if (!lock->convert_pending) {
331		mlog(0, "%s: res %.*s, owner died and lock has been moved back "
332				"to granted list, retry convert.\n",
333				dlm->name, res->lockname.len, res->lockname.name);
334		status = DLM_RECOVERING;
335	}
336
337	lock->convert_pending = 0;
338bail:
339	spin_unlock(&res->spinlock);
340
341	/* TODO: should this be a wake_one? */
342	/* wake up any IN_PROGRESS waiters */
343	wake_up(&res->wq);
344
345	return status;
346}
347
348/* sends DLM_CONVERT_LOCK_MSG to master site
349 * locking:
350 *   caller needs:  none
351 *   taken:         none
352 *   held on exit:  none
353 * returns: DLM_NOLOCKMGR, status from remote node
354 */
355static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
356					   struct dlm_lock_resource *res,
357					   struct dlm_lock *lock, int flags, int type)
358{
359	struct dlm_convert_lock convert;
360	int tmpret;
361	enum dlm_status ret;
362	int status = 0;
363	struct kvec vec[2];
364	size_t veclen = 1;
365
366	mlog(0, "%.*s\n", res->lockname.len, res->lockname.name);
367
368	memset(&convert, 0, sizeof(struct dlm_convert_lock));
369	convert.node_idx = dlm->node_num;
370	convert.requested_type = type;
371	convert.cookie = lock->ml.cookie;
372	convert.namelen = res->lockname.len;
373	convert.flags = cpu_to_be32(flags);
374	memcpy(convert.name, res->lockname.name, convert.namelen);
375
376	vec[0].iov_len = sizeof(struct dlm_convert_lock);
377	vec[0].iov_base = &convert;
378
379	if (flags & LKM_PUT_LVB) {
380		/* extra data to send if we are updating lvb */
381		vec[1].iov_len = DLM_LVB_LEN;
382		vec[1].iov_base = lock->lksb->lvb;
383		veclen++;
384	}
385
386	tmpret = o2net_send_message_vec(DLM_CONVERT_LOCK_MSG, dlm->key,
387					vec, veclen, res->owner, &status);
388	if (tmpret >= 0) {
389		// successfully sent and received
390		ret = status;  // this is already a dlm_status
391		if (ret == DLM_RECOVERING) {
392			mlog(0, "node %u returned DLM_RECOVERING from convert "
393			     "message!\n", res->owner);
394		} else if (ret == DLM_MIGRATING) {
395			mlog(0, "node %u returned DLM_MIGRATING from convert "
396			     "message!\n", res->owner);
397		} else if (ret == DLM_FORWARD) {
398			mlog(0, "node %u returned DLM_FORWARD from convert "
399			     "message!\n", res->owner);
400		} else if (ret != DLM_NORMAL && ret != DLM_NOTQUEUED)
401			dlm_error(ret);
402	} else {
403		mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
404		     "node %u\n", tmpret, DLM_CONVERT_LOCK_MSG, dlm->key,
405		     res->owner);
406		if (dlm_is_host_down(tmpret)) {
407			/* instead of logging the same network error over
408			 * and over, sleep here and wait for the heartbeat
409			 * to notice the node is dead.  times out after 5s. */
410			dlm_wait_for_node_death(dlm, res->owner,
411						DLM_NODE_DEATH_WAIT_MAX);
412			ret = DLM_RECOVERING;
413			mlog(0, "node %u died so returning DLM_RECOVERING "
414			     "from convert message!\n", res->owner);
415		} else {
416			ret = dlm_err_to_dlm_status(tmpret);
417		}
418	}
419
420	return ret;
421}
422
423/* handler for DLM_CONVERT_LOCK_MSG on master site
424 * locking:
425 *   caller needs:  none
426 *   taken:         takes and drop res->spinlock
427 *   held on exit:  none
428 * returns: DLM_NORMAL, DLM_IVLOCKID, DLM_BADARGS,
429 *          status from __dlmconvert_master
430 */
431int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data,
432			     void **ret_data)
433{
434	struct dlm_ctxt *dlm = data;
435	struct dlm_convert_lock *cnv = (struct dlm_convert_lock *)msg->buf;
436	struct dlm_lock_resource *res = NULL;
437	struct dlm_lock *lock = NULL;
438	struct dlm_lock *tmp_lock;
439	struct dlm_lockstatus *lksb;
440	enum dlm_status status = DLM_NORMAL;
441	u32 flags;
442	int call_ast = 0, kick_thread = 0, ast_reserved = 0, wake = 0;
443
444	if (!dlm_grab(dlm)) {
445		dlm_error(DLM_REJECTED);
446		return DLM_REJECTED;
447	}
448
449	mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
450			"Domain %s not fully joined!\n", dlm->name);
451
452	if (cnv->namelen > DLM_LOCKID_NAME_MAX) {
453		status = DLM_IVBUFLEN;
454		dlm_error(status);
455		goto leave;
456	}
457
458	flags = be32_to_cpu(cnv->flags);
459
460	if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) ==
461	     (LKM_PUT_LVB|LKM_GET_LVB)) {
462		mlog(ML_ERROR, "both PUT and GET lvb specified\n");
463		status = DLM_BADARGS;
464		goto leave;
465	}
466
467	mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" :
468	     (flags & LKM_GET_LVB ? "get lvb" : "none"));
469
470	status = DLM_IVLOCKID;
471	res = dlm_lookup_lockres(dlm, cnv->name, cnv->namelen);
472	if (!res) {
473		dlm_error(status);
474		goto leave;
475	}
476
477	spin_lock(&res->spinlock);
478	status = __dlm_lockres_state_to_status(res);
479	if (status != DLM_NORMAL) {
480		spin_unlock(&res->spinlock);
481		dlm_error(status);
482		goto leave;
483	}
484	list_for_each_entry(tmp_lock, &res->granted, list) {
485		if (tmp_lock->ml.cookie == cnv->cookie &&
486		    tmp_lock->ml.node == cnv->node_idx) {
487			lock = tmp_lock;
488			dlm_lock_get(lock);
489			break;
490		}
491	}
492	spin_unlock(&res->spinlock);
493	if (!lock) {
494		status = DLM_IVLOCKID;
495		mlog(ML_ERROR, "did not find lock to convert on grant queue! "
496			       "cookie=%u:%llu\n",
497		     dlm_get_lock_cookie_node(be64_to_cpu(cnv->cookie)),
498		     dlm_get_lock_cookie_seq(be64_to_cpu(cnv->cookie)));
499		dlm_print_one_lock_resource(res);
500		goto leave;
501	}
502
503	/* found the lock */
504	lksb = lock->lksb;
505
506	/* see if caller needed to get/put lvb */
507	if (flags & LKM_PUT_LVB) {
508		BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
509		lksb->flags |= DLM_LKSB_PUT_LVB;
510		memcpy(&lksb->lvb[0], &cnv->lvb[0], DLM_LVB_LEN);
511	} else if (flags & LKM_GET_LVB) {
512		BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
513		lksb->flags |= DLM_LKSB_GET_LVB;
514	}
515
516	spin_lock(&res->spinlock);
517	status = __dlm_lockres_state_to_status(res);
518	if (status == DLM_NORMAL) {
519		__dlm_lockres_reserve_ast(res);
520		ast_reserved = 1;
521		res->state |= DLM_LOCK_RES_IN_PROGRESS;
522		status = __dlmconvert_master(dlm, res, lock, flags,
523					     cnv->requested_type,
524					     &call_ast, &kick_thread);
525		res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
526		wake = 1;
527	}
528	spin_unlock(&res->spinlock);
529	if (wake)
530		wake_up(&res->wq);
531
532	if (status != DLM_NORMAL) {
533		if (status != DLM_NOTQUEUED)
534			dlm_error(status);
535		lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
536	}
537
538leave:
539	if (lock)
540		dlm_lock_put(lock);
541
542	/* either queue the ast or release it, if reserved */
543	if (call_ast)
544		dlm_queue_ast(dlm, lock);
545	else if (ast_reserved)
546		dlm_lockres_release_ast(dlm, res);
547
548	if (kick_thread)
549		dlm_kick_thread(dlm, res);
550
551	if (res)
552		dlm_lockres_put(res);
553
554	dlm_put(dlm);
555
556	return status;
557}
558