1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * dlmconvert.c
5 *
6 * underlying calls for lock conversion
7 *
8 * Copyright (C) 2004 Oracle.  All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
24 *
25 */
26
27
28#include <linux/module.h>
29#include <linux/fs.h>
30#include <linux/types.h>
31#include <linux/highmem.h>
32#include <linux/init.h>
33#include <linux/sysctl.h>
34#include <linux/random.h>
35#include <linux/blkdev.h>
36#include <linux/socket.h>
37#include <linux/inet.h>
38#include <linux/spinlock.h>
39
40
41#include "cluster/heartbeat.h"
42#include "cluster/nodemanager.h"
43#include "cluster/tcp.h"
44
45#include "dlmapi.h"
46#include "dlmcommon.h"
47
48#include "dlmconvert.h"
49
50#define MLOG_MASK_PREFIX ML_DLM
51#include "cluster/masklog.h"
52
53/* NOTE: __dlmconvert_master is the only function in here that
54 * needs a spinlock held on entry (res->spinlock) and it is the
55 * only one that holds a lock on exit (res->spinlock).
56 * All other functions in here need no locks and drop all of
57 * the locks that they acquire. */
58static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
59					   struct dlm_lock_resource *res,
60					   struct dlm_lock *lock, int flags,
61					   int type, int *call_ast,
62					   int *kick_thread);
63static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
64					   struct dlm_lock_resource *res,
65					   struct dlm_lock *lock, int flags, int type);
66
67/*
68 * this is only called directly by dlmlock(), and only when the
69 * local node is the owner of the lockres
70 * locking:
71 *   caller needs:  none
72 *   taken:         takes and drops res->spinlock
73 *   held on exit:  none
74 * returns: see __dlmconvert_master
75 */
76enum dlm_status dlmconvert_master(struct dlm_ctxt *dlm,
77				  struct dlm_lock_resource *res,
78				  struct dlm_lock *lock, int flags, int type)
79{
80	int call_ast = 0, kick_thread = 0;
81	enum dlm_status status;
82
83	spin_lock(&res->spinlock);
84	/* we are not in a network handler, this is fine */
85	__dlm_wait_on_lockres(res);
86	__dlm_lockres_reserve_ast(res);
87	res->state |= DLM_LOCK_RES_IN_PROGRESS;
88
89	status = __dlmconvert_master(dlm, res, lock, flags, type,
90				     &call_ast, &kick_thread);
91
92	res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
93	spin_unlock(&res->spinlock);
94	wake_up(&res->wq);
95	if (status != DLM_NORMAL && status != DLM_NOTQUEUED)
96		dlm_error(status);
97
98	/* either queue the ast or release it */
99	if (call_ast)
100		dlm_queue_ast(dlm, lock);
101	else
102		dlm_lockres_release_ast(dlm, res);
103
104	if (kick_thread)
105		dlm_kick_thread(dlm, res);
106
107	return status;
108}
109
110/* performs lock conversion at the lockres master site
111 * locking:
112 *   caller needs:  res->spinlock
113 *   taken:         takes and drops lock->spinlock
114 *   held on exit:  res->spinlock
115 * returns: DLM_NORMAL, DLM_NOTQUEUED, DLM_DENIED
116 *   call_ast: whether ast should be called for this lock
117 *   kick_thread: whether dlm_kick_thread should be called
118 */
119static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
120					   struct dlm_lock_resource *res,
121					   struct dlm_lock *lock, int flags,
122					   int type, int *call_ast,
123					   int *kick_thread)
124{
125	enum dlm_status status = DLM_NORMAL;
126	struct dlm_lock *tmplock=NULL;
127
128	assert_spin_locked(&res->spinlock);
129
130	mlog(0, "type=%d, convert_type=%d, new convert_type=%d\n",
131	     lock->ml.type, lock->ml.convert_type, type);
132
133	spin_lock(&lock->spinlock);
134
135	/* already converting? */
136	if (lock->ml.convert_type != LKM_IVMODE) {
137		mlog(ML_ERROR, "attempted to convert a lock with a lock "
138		     "conversion pending\n");
139		status = DLM_DENIED;
140		goto unlock_exit;
141	}
142
143	/* must be on grant queue to convert */
144	if (!dlm_lock_on_list(&res->granted, lock)) {
145		mlog(ML_ERROR, "attempted to convert a lock not on grant "
146		     "queue\n");
147		status = DLM_DENIED;
148		goto unlock_exit;
149	}
150
151	if (flags & LKM_VALBLK) {
152		switch (lock->ml.type) {
153			case LKM_EXMODE:
154				/* EX + LKM_VALBLK + convert == set lvb */
155				mlog(0, "will set lvb: converting %s->%s\n",
156				     dlm_lock_mode_name(lock->ml.type),
157				     dlm_lock_mode_name(type));
158				lock->lksb->flags |= DLM_LKSB_PUT_LVB;
159				break;
160			case LKM_PRMODE:
161			case LKM_NLMODE:
162				/* refetch if new level is not NL */
163				if (type > LKM_NLMODE) {
164					mlog(0, "will fetch new value into "
165					     "lvb: converting %s->%s\n",
166					     dlm_lock_mode_name(lock->ml.type),
167					     dlm_lock_mode_name(type));
168					lock->lksb->flags |= DLM_LKSB_GET_LVB;
169				} else {
170					mlog(0, "will NOT fetch new value "
171					     "into lvb: converting %s->%s\n",
172					     dlm_lock_mode_name(lock->ml.type),
173					     dlm_lock_mode_name(type));
174					flags &= ~(LKM_VALBLK);
175				}
176				break;
177		}
178	}
179
180
181	/* in-place downconvert? */
182	if (type <= lock->ml.type)
183		goto grant;
184
185	/* upconvert from here on */
186	status = DLM_NORMAL;
187	list_for_each_entry(tmplock, &res->granted, list) {
188		if (tmplock == lock)
189			continue;
190		if (!dlm_lock_compatible(tmplock->ml.type, type))
191			goto switch_queues;
192	}
193
194	list_for_each_entry(tmplock, &res->converting, list) {
195		if (!dlm_lock_compatible(tmplock->ml.type, type))
196			goto switch_queues;
197		/* existing conversion requests take precedence */
198		if (!dlm_lock_compatible(tmplock->ml.convert_type, type))
199			goto switch_queues;
200	}
201
202	/* fall thru to grant */
203
204grant:
205	mlog(0, "res %.*s, granting %s lock\n", res->lockname.len,
206	     res->lockname.name, dlm_lock_mode_name(type));
207	/* immediately grant the new lock type */
208	lock->lksb->status = DLM_NORMAL;
209	if (lock->ml.node == dlm->node_num)
210		mlog(0, "doing in-place convert for nonlocal lock\n");
211	lock->ml.type = type;
212	if (lock->lksb->flags & DLM_LKSB_PUT_LVB)
213		memcpy(res->lvb, lock->lksb->lvb, DLM_LVB_LEN);
214
215	status = DLM_NORMAL;
216	*call_ast = 1;
217	goto unlock_exit;
218
219switch_queues:
220	if (flags & LKM_NOQUEUE) {
221		mlog(0, "failed to convert NOQUEUE lock %.*s from "
222		     "%d to %d...\n", res->lockname.len, res->lockname.name,
223		     lock->ml.type, type);
224		status = DLM_NOTQUEUED;
225		goto unlock_exit;
226	}
227	mlog(0, "res %.*s, queueing...\n", res->lockname.len,
228	     res->lockname.name);
229
230	lock->ml.convert_type = type;
231	/* do not alter lock refcount.  switching lists. */
232	list_move_tail(&lock->list, &res->converting);
233
234unlock_exit:
235	spin_unlock(&lock->spinlock);
236	if (status == DLM_DENIED) {
237		__dlm_print_one_lock_resource(res);
238	}
239	if (status == DLM_NORMAL)
240		*kick_thread = 1;
241	return status;
242}
243
244void dlm_revert_pending_convert(struct dlm_lock_resource *res,
245				struct dlm_lock *lock)
246{
247	/* do not alter lock refcount.  switching lists. */
248	list_move_tail(&lock->list, &res->granted);
249	lock->ml.convert_type = LKM_IVMODE;
250	lock->lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
251}
252
253/* messages the master site to do lock conversion
254 * locking:
255 *   caller needs:  none
256 *   taken:         takes and drops res->spinlock, uses DLM_LOCK_RES_IN_PROGRESS
257 *   held on exit:  none
258 * returns: DLM_NORMAL, DLM_RECOVERING, status from remote node
259 */
260enum dlm_status dlmconvert_remote(struct dlm_ctxt *dlm,
261				  struct dlm_lock_resource *res,
262				  struct dlm_lock *lock, int flags, int type)
263{
264	enum dlm_status status;
265	u8 old_owner = res->owner;
266
267	mlog(0, "type=%d, convert_type=%d, busy=%d\n", lock->ml.type,
268	     lock->ml.convert_type, res->state & DLM_LOCK_RES_IN_PROGRESS);
269
270	spin_lock(&res->spinlock);
271	if (res->state & DLM_LOCK_RES_RECOVERING) {
272		mlog(0, "bailing out early since res is RECOVERING "
273		     "on secondary queue\n");
274		/* __dlm_print_one_lock_resource(res); */
275		status = DLM_RECOVERING;
276		goto bail;
277	}
278	/* will exit this call with spinlock held */
279	__dlm_wait_on_lockres(res);
280
281	if (lock->ml.convert_type != LKM_IVMODE) {
282		__dlm_print_one_lock_resource(res);
283		mlog(ML_ERROR, "converting a remote lock that is already "
284		     "converting! (cookie=%u:%llu, conv=%d)\n",
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.convert_type);
288		status = DLM_DENIED;
289		goto bail;
290	}
291
292	if (lock->ml.type == type && lock->ml.convert_type == LKM_IVMODE) {
293		mlog(0, "last convert request returned DLM_RECOVERING, but "
294		     "owner has already queued and sent ast to me. res %.*s, "
295		     "(cookie=%u:%llu, type=%d, conv=%d)\n",
296		     res->lockname.len, res->lockname.name,
297		     dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
298		     dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
299		     lock->ml.type, lock->ml.convert_type);
300		status = DLM_NORMAL;
301		goto bail;
302	}
303
304	res->state |= DLM_LOCK_RES_IN_PROGRESS;
305	/* move lock to local convert queue */
306	/* do not alter lock refcount.  switching lists. */
307	list_move_tail(&lock->list, &res->converting);
308	lock->convert_pending = 1;
309	lock->ml.convert_type = type;
310
311	if (flags & LKM_VALBLK) {
312		if (lock->ml.type == LKM_EXMODE) {
313			flags |= LKM_PUT_LVB;
314			lock->lksb->flags |= DLM_LKSB_PUT_LVB;
315		} else {
316			if (lock->ml.convert_type == LKM_NLMODE)
317				flags &= ~LKM_VALBLK;
318			else {
319				flags |= LKM_GET_LVB;
320				lock->lksb->flags |= DLM_LKSB_GET_LVB;
321			}
322		}
323	}
324	spin_unlock(&res->spinlock);
325
326	/* no locks held here.
327	 * need to wait for a reply as to whether it got queued or not. */
328	status = dlm_send_remote_convert_request(dlm, res, lock, flags, type);
329
330	spin_lock(&res->spinlock);
331	res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
332	lock->convert_pending = 0;
333	/* if it failed, move it back to granted queue.
334	 * if master returns DLM_NORMAL and then down before sending ast,
335	 * it may have already been moved to granted queue, reset to
336	 * DLM_RECOVERING and retry convert */
337	if (status != DLM_NORMAL) {
338		if (status != DLM_NOTQUEUED)
339			dlm_error(status);
340		dlm_revert_pending_convert(res, lock);
341	} else if ((res->state & DLM_LOCK_RES_RECOVERING) ||
342			(old_owner != res->owner)) {
343		mlog(0, "res %.*s is in recovering or has been recovered.\n",
344				res->lockname.len, res->lockname.name);
345		status = DLM_RECOVERING;
346	}
347bail:
348	spin_unlock(&res->spinlock);
349
350	/* TODO: should this be a wake_one? */
351	/* wake up any IN_PROGRESS waiters */
352	wake_up(&res->wq);
353
354	return status;
355}
356
357/* sends DLM_CONVERT_LOCK_MSG to master site
358 * locking:
359 *   caller needs:  none
360 *   taken:         none
361 *   held on exit:  none
362 * returns: DLM_NOLOCKMGR, status from remote node
363 */
364static enum dlm_status dlm_send_remote_convert_request(struct dlm_ctxt *dlm,
365					   struct dlm_lock_resource *res,
366					   struct dlm_lock *lock, int flags, int type)
367{
368	struct dlm_convert_lock convert;
369	int tmpret;
370	enum dlm_status ret;
371	int status = 0;
372	struct kvec vec[2];
373	size_t veclen = 1;
374
375	mlog(0, "%.*s\n", res->lockname.len, res->lockname.name);
376
377	memset(&convert, 0, sizeof(struct dlm_convert_lock));
378	convert.node_idx = dlm->node_num;
379	convert.requested_type = type;
380	convert.cookie = lock->ml.cookie;
381	convert.namelen = res->lockname.len;
382	convert.flags = cpu_to_be32(flags);
383	memcpy(convert.name, res->lockname.name, convert.namelen);
384
385	vec[0].iov_len = sizeof(struct dlm_convert_lock);
386	vec[0].iov_base = &convert;
387
388	if (flags & LKM_PUT_LVB) {
389		/* extra data to send if we are updating lvb */
390		vec[1].iov_len = DLM_LVB_LEN;
391		vec[1].iov_base = lock->lksb->lvb;
392		veclen++;
393	}
394
395	tmpret = o2net_send_message_vec(DLM_CONVERT_LOCK_MSG, dlm->key,
396					vec, veclen, res->owner, &status);
397	if (tmpret >= 0) {
398		// successfully sent and received
399		ret = status;  // this is already a dlm_status
400		if (ret == DLM_RECOVERING) {
401			mlog(0, "node %u returned DLM_RECOVERING from convert "
402			     "message!\n", res->owner);
403		} else if (ret == DLM_MIGRATING) {
404			mlog(0, "node %u returned DLM_MIGRATING from convert "
405			     "message!\n", res->owner);
406		} else if (ret == DLM_FORWARD) {
407			mlog(0, "node %u returned DLM_FORWARD from convert "
408			     "message!\n", res->owner);
409		} else if (ret != DLM_NORMAL && ret != DLM_NOTQUEUED)
410			dlm_error(ret);
411	} else {
412		mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
413		     "node %u\n", tmpret, DLM_CONVERT_LOCK_MSG, dlm->key,
414		     res->owner);
415		if (dlm_is_host_down(tmpret)) {
416			/* instead of logging the same network error over
417			 * and over, sleep here and wait for the heartbeat
418			 * to notice the node is dead.  times out after 5s. */
419			dlm_wait_for_node_death(dlm, res->owner,
420						DLM_NODE_DEATH_WAIT_MAX);
421			ret = DLM_RECOVERING;
422			mlog(0, "node %u died so returning DLM_RECOVERING "
423			     "from convert message!\n", res->owner);
424		} else {
425			ret = dlm_err_to_dlm_status(tmpret);
426		}
427	}
428
429	return ret;
430}
431
432/* handler for DLM_CONVERT_LOCK_MSG on master site
433 * locking:
434 *   caller needs:  none
435 *   taken:         takes and drop res->spinlock
436 *   held on exit:  none
437 * returns: DLM_NORMAL, DLM_IVLOCKID, DLM_BADARGS,
438 *          status from __dlmconvert_master
439 */
440int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data,
441			     void **ret_data)
442{
443	struct dlm_ctxt *dlm = data;
444	struct dlm_convert_lock *cnv = (struct dlm_convert_lock *)msg->buf;
445	struct dlm_lock_resource *res = NULL;
446	struct dlm_lock *lock = NULL;
447	struct dlm_lock *tmp_lock;
448	struct dlm_lockstatus *lksb;
449	enum dlm_status status = DLM_NORMAL;
450	u32 flags;
451	int call_ast = 0, kick_thread = 0, ast_reserved = 0, wake = 0;
452
453	if (!dlm_grab(dlm)) {
454		dlm_error(DLM_REJECTED);
455		return DLM_REJECTED;
456	}
457
458	mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
459			"Domain %s not fully joined!\n", dlm->name);
460
461	if (cnv->namelen > DLM_LOCKID_NAME_MAX) {
462		status = DLM_IVBUFLEN;
463		dlm_error(status);
464		goto leave;
465	}
466
467	flags = be32_to_cpu(cnv->flags);
468
469	if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) ==
470	     (LKM_PUT_LVB|LKM_GET_LVB)) {
471		mlog(ML_ERROR, "both PUT and GET lvb specified\n");
472		status = DLM_BADARGS;
473		goto leave;
474	}
475
476	mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" :
477	     (flags & LKM_GET_LVB ? "get lvb" : "none"));
478
479	status = DLM_IVLOCKID;
480	res = dlm_lookup_lockres(dlm, cnv->name, cnv->namelen);
481	if (!res) {
482		dlm_error(status);
483		goto leave;
484	}
485
486	spin_lock(&res->spinlock);
487	status = __dlm_lockres_state_to_status(res);
488	if (status != DLM_NORMAL) {
489		spin_unlock(&res->spinlock);
490		dlm_error(status);
491		goto leave;
492	}
493	list_for_each_entry(tmp_lock, &res->granted, list) {
494		if (tmp_lock->ml.cookie == cnv->cookie &&
495		    tmp_lock->ml.node == cnv->node_idx) {
496			lock = tmp_lock;
497			dlm_lock_get(lock);
498			break;
499		}
500	}
501	spin_unlock(&res->spinlock);
502	if (!lock) {
503		status = DLM_IVLOCKID;
504		mlog(ML_ERROR, "did not find lock to convert on grant queue! "
505			       "cookie=%u:%llu\n",
506		     dlm_get_lock_cookie_node(be64_to_cpu(cnv->cookie)),
507		     dlm_get_lock_cookie_seq(be64_to_cpu(cnv->cookie)));
508		dlm_print_one_lock_resource(res);
509		goto leave;
510	}
511
512	/* found the lock */
513	lksb = lock->lksb;
514
515	/* see if caller needed to get/put lvb */
516	if (flags & LKM_PUT_LVB) {
517		BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
518		lksb->flags |= DLM_LKSB_PUT_LVB;
519		memcpy(&lksb->lvb[0], &cnv->lvb[0], DLM_LVB_LEN);
520	} else if (flags & LKM_GET_LVB) {
521		BUG_ON(lksb->flags & (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
522		lksb->flags |= DLM_LKSB_GET_LVB;
523	}
524
525	spin_lock(&res->spinlock);
526	status = __dlm_lockres_state_to_status(res);
527	if (status == DLM_NORMAL) {
528		__dlm_lockres_reserve_ast(res);
529		ast_reserved = 1;
530		res->state |= DLM_LOCK_RES_IN_PROGRESS;
531		status = __dlmconvert_master(dlm, res, lock, flags,
532					     cnv->requested_type,
533					     &call_ast, &kick_thread);
534		res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
535		wake = 1;
536	}
537	spin_unlock(&res->spinlock);
538	if (wake)
539		wake_up(&res->wq);
540
541	if (status != DLM_NORMAL) {
542		if (status != DLM_NOTQUEUED)
543			dlm_error(status);
544		lksb->flags &= ~(DLM_LKSB_GET_LVB|DLM_LKSB_PUT_LVB);
545	}
546
547leave:
548	if (lock)
549		dlm_lock_put(lock);
550
551	/* either queue the ast or release it, if reserved */
552	if (call_ast)
553		dlm_queue_ast(dlm, lock);
554	else if (ast_reserved)
555		dlm_lockres_release_ast(dlm, res);
556
557	if (kick_thread)
558		dlm_kick_thread(dlm, res);
559
560	if (res)
561		dlm_lockres_put(res);
562
563	dlm_put(dlm);
564
565	return status;
566}
567