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