1/*-
2 * See the file LICENSE for redistribution information.
3 *
4 * Copyright (c) 1996,2008 Oracle.  All rights reserved.
5 *
6 * $Id: dbreg.c,v 12.38 2008/03/12 20:46:37 mbrey Exp $
7 */
8
9#include "db_config.h"
10
11#include "db_int.h"
12#include "dbinc/db_page.h"
13#include "dbinc/log.h"
14#include "dbinc/txn.h"
15#include "dbinc/db_am.h"
16
17static int __dbreg_push_id __P((ENV *, int32_t));
18static int __dbreg_pop_id __P((ENV *, int32_t *));
19static int __dbreg_pluck_id __P((ENV *, int32_t));
20
21/*
22 * The dbreg subsystem, as its name implies, registers database handles so
23 * that we can associate log messages with them without logging a filename
24 * or a full, unique DB ID.  Instead, we assign each dbp an int32_t which is
25 * easy and cheap to log, and use this subsystem to map back and forth.
26 *
27 * Overview of how dbreg ids are managed:
28 *
29 * OPEN
30 *	dbreg_setup (Creates FNAME struct.)
31 *	dbreg_new_id (Assigns new ID to dbp and logs it.  May be postponed
32 *	until we attempt to log something else using that dbp, if the dbp
33 *	was opened on a replication client.)
34 *
35 * CLOSE
36 *	dbreg_close_id  (Logs closure of dbp/revocation of ID.)
37 *	dbreg_revoke_id (As name implies, revokes ID.)
38 *	dbreg_teardown (Destroys FNAME.)
39 *
40 * RECOVERY
41 *	dbreg_setup
42 *	dbreg_assign_id (Assigns a particular ID we have in the log to a dbp.)
43 *
44 *	sometimes: dbreg_revoke_id; dbreg_teardown
45 *	other times: normal close path
46 *
47 * A note about locking:
48 *
49 *	FNAME structures are referenced only by their corresponding dbp's
50 *	until they have a valid id.
51 *
52 *	Once they have a valid id, they must get linked into the log
53 *	region list so they can get logged on checkpoints.
54 *
55 *	An FNAME that may/does have a valid id must be accessed under
56 *	protection of the mtx_filelist, with the following exception:
57 *
58 *	We don't want to have to grab the mtx_filelist on every log
59 *	record, and it should be safe not to do so when we're just
60 *	looking at the id, because once allocated, the id should
61 *	not change under a handle until the handle is closed.
62 *
63 *	If a handle is closed during an attempt by another thread to
64 *	log with it, well, the application doing the close deserves to
65 *	go down in flames and a lot else is about to fail anyway.
66 *
67 *	When in the course of logging we encounter an invalid id
68 *	and go to allocate it lazily, we *do* need to check again
69 *	after grabbing the mutex, because it's possible to race with
70 *	another thread that has also decided that it needs to allocate
71 *	a id lazily.
72 *
73 * See SR #5623 for further discussion of the new dbreg design.
74 */
75
76/*
77 * __dbreg_setup --
78 *	Allocate and initialize an FNAME structure.  The FNAME structures
79 * live in the log shared region and map one-to-one with open database handles.
80 * When the handle needs to be logged, the FNAME should have a valid fid
81 * allocated.  If the handle currently isn't logged, it still has an FNAME
82 * entry.  If we later discover that the handle needs to be logged, we can
83 * allocate a id for it later.  (This happens when the handle is on a
84 * replication client that later becomes a master.)
85 *
86 * PUBLIC: int __dbreg_setup __P((DB *, const char *, const char *, u_int32_t));
87 */
88int
89__dbreg_setup(dbp, fname, dname, create_txnid)
90	DB *dbp;
91	const char *fname, *dname;
92	u_int32_t create_txnid;
93{
94	DB_LOG *dblp;
95	ENV *env;
96	FNAME *fnp;
97	REGINFO *infop;
98	int ret;
99	size_t len;
100	void *p;
101
102	env = dbp->env;
103	dblp = env->lg_handle;
104	infop = &dblp->reginfo;
105
106	fnp = NULL;
107	p = NULL;
108
109	/* Allocate an FNAME and, if necessary, a buffer for the name itself. */
110	LOG_SYSTEM_LOCK(env);
111	if ((ret = __env_alloc(infop, sizeof(FNAME), &fnp)) != 0)
112		goto err;
113	memset(fnp, 0, sizeof(FNAME));
114	if (fname == NULL)
115		fnp->fname_off = INVALID_ROFF;
116	else {
117		len = strlen(fname) + 1;
118		if ((ret = __env_alloc(infop, len, &p)) != 0)
119			goto err;
120		fnp->fname_off = R_OFFSET(infop, p);
121		memcpy(p, fname, len);
122	}
123	if (dname == NULL)
124		fnp->dname_off = INVALID_ROFF;
125	else {
126		len = strlen(dname) + 1;
127		if ((ret = __env_alloc(infop, len, &p)) != 0)
128			goto err;
129		fnp->dname_off = R_OFFSET(infop, p);
130		memcpy(p, dname, len);
131	}
132	LOG_SYSTEM_UNLOCK(env);
133
134	/*
135	 * Fill in all the remaining info that we'll need later to register
136	 * the file, if we use it for logging.
137	 */
138	fnp->id = fnp->old_id = DB_LOGFILEID_INVALID;
139	fnp->s_type = dbp->type;
140	memcpy(fnp->ufid, dbp->fileid, DB_FILE_ID_LEN);
141	fnp->meta_pgno = dbp->meta_pgno;
142	fnp->create_txnid = create_txnid;
143	dbp->dbenv->thread_id(dbp->dbenv, &fnp->pid, NULL);
144
145	if (F_ISSET(dbp, DB_AM_INMEM))
146		F_SET(fnp, DB_FNAME_INMEM);
147	if (F_ISSET(dbp, DB_AM_RECOVER))
148		F_SET(fnp, DB_FNAME_RECOVER);
149	fnp->txn_ref = 1;
150	fnp->mutex = dbp->mutex;
151
152	dbp->log_filename = fnp;
153
154	return (0);
155
156err:	LOG_SYSTEM_UNLOCK(env);
157	if (ret == ENOMEM)
158		__db_errx(env,
159    "Logging region out of memory; you may need to increase its size");
160
161	return (ret);
162}
163
164/*
165 * __dbreg_teardown --
166 *	Destroy a DB handle's FNAME struct.  This is only called when closing
167 * the DB.
168 *
169 * PUBLIC: int __dbreg_teardown __P((DB *));
170 */
171int
172__dbreg_teardown(dbp)
173	DB *dbp;
174{
175	int ret;
176
177	/*
178	 * We may not have an FNAME if we were never opened.  This is not an
179	 * error.
180	 */
181	if (dbp->log_filename == NULL)
182		return (0);
183
184	ret = __dbreg_teardown_int(dbp->env, dbp->log_filename);
185
186	/* We freed the copy of the mutex from the FNAME. */
187	dbp->log_filename = NULL;
188	dbp->mutex = MUTEX_INVALID;
189
190	return (ret);
191}
192
193/*
194 * __dbreg_teardown_int --
195 *	Destroy an FNAME struct.
196 *
197 * PUBLIC: int __dbreg_teardown_int __P((ENV *, FNAME *));
198 */
199int
200__dbreg_teardown_int(env, fnp)
201	ENV *env;
202	FNAME *fnp;
203{
204	DB_LOG *dblp;
205	REGINFO *infop;
206	int ret;
207
208	if (F_ISSET(fnp, DB_FNAME_NOTLOGGED))
209		return (0);
210	dblp = env->lg_handle;
211	infop = &dblp->reginfo;
212
213	DB_ASSERT(env, fnp->id == DB_LOGFILEID_INVALID);
214	ret = __mutex_free(env, &fnp->mutex);
215
216	LOG_SYSTEM_LOCK(env);
217	if (fnp->fname_off != INVALID_ROFF)
218		__env_alloc_free(infop, R_ADDR(infop, fnp->fname_off));
219	if (fnp->dname_off != INVALID_ROFF)
220		__env_alloc_free(infop, R_ADDR(infop, fnp->dname_off));
221	__env_alloc_free(infop, fnp);
222	LOG_SYSTEM_UNLOCK(env);
223
224	return (ret);
225}
226
227/*
228 * __dbreg_new_id --
229 *	Get an unused dbreg id to this database handle.
230 *	Used as a wrapper to acquire the mutex and
231 *	only set the id on success.
232 *
233 * PUBLIC: int __dbreg_new_id __P((DB *, DB_TXN *));
234 */
235int
236__dbreg_new_id(dbp, txn)
237	DB *dbp;
238	DB_TXN *txn;
239{
240	DB_LOG *dblp;
241	ENV *env;
242	FNAME *fnp;
243	LOG *lp;
244	int32_t id;
245	int ret;
246
247	env = dbp->env;
248	dblp = env->lg_handle;
249	lp = dblp->reginfo.primary;
250	fnp = dbp->log_filename;
251
252	/* The mtx_filelist protects the FNAME list and id management. */
253	MUTEX_LOCK(env, lp->mtx_filelist);
254	if (fnp->id != DB_LOGFILEID_INVALID) {
255		MUTEX_UNLOCK(env, lp->mtx_filelist);
256		return (0);
257	}
258	if ((ret = __dbreg_get_id(dbp, txn, &id)) == 0)
259		fnp->id = id;
260	MUTEX_UNLOCK(env, lp->mtx_filelist);
261	return (ret);
262}
263
264/*
265 * __dbreg_get_id --
266 *	Assign an unused dbreg id to this database handle.
267 *	Assume the caller holds the mtx_filelist locked.  Assume the
268 *	caller will set the fnp->id field with the id we return.
269 *
270 * PUBLIC: int __dbreg_get_id __P((DB *, DB_TXN *, int32_t *));
271 */
272int
273__dbreg_get_id(dbp, txn, idp)
274	DB *dbp;
275	DB_TXN *txn;
276	int32_t *idp;
277{
278	DB_LOG *dblp;
279	ENV *env;
280	FNAME *fnp;
281	LOG *lp;
282	int32_t id;
283	int ret;
284
285	env = dbp->env;
286	dblp = env->lg_handle;
287	lp = dblp->reginfo.primary;
288	fnp = dbp->log_filename;
289
290	/*
291	 * It's possible that after deciding we needed to call this function,
292	 * someone else allocated an ID before we grabbed the lock.  Check
293	 * to make sure there was no race and we have something useful to do.
294	 */
295	/* Get an unused ID from the free list. */
296	if ((ret = __dbreg_pop_id(env, &id)) != 0)
297		goto err;
298
299	/* If no ID was found, allocate a new one. */
300	if (id == DB_LOGFILEID_INVALID)
301		id = lp->fid_max++;
302
303	/* If the file is durable (i.e., not, not-durable), mark it as such. */
304	if (!F_ISSET(dbp, DB_AM_NOT_DURABLE))
305		F_SET(fnp, DB_FNAME_DURABLE);
306
307	/* Hook the FNAME into the list of open files. */
308	SH_TAILQ_INSERT_HEAD(&lp->fq, fnp, q, __fname);
309
310	/*
311	 * Log the registry.  We should only request a new ID in situations
312	 * where logging is reasonable.
313	 */
314	DB_ASSERT(env, !F_ISSET(dbp, DB_AM_RECOVER));
315
316	if ((ret = __dbreg_log_id(dbp, txn, id, 0)) != 0)
317		goto err;
318
319	/*
320	 * Once we log the create_txnid, we need to make sure we never
321	 * log it again (as might happen if this is a replication client
322	 * that later upgrades to a master).
323	 */
324	fnp->create_txnid = TXN_INVALID;
325
326	DB_ASSERT(env, dbp->type == fnp->s_type);
327	DB_ASSERT(env, dbp->meta_pgno == fnp->meta_pgno);
328
329	if ((ret = __dbreg_add_dbentry(env, dblp, dbp, id)) != 0)
330		goto err;
331	/*
332	 * If we have a successful call, set the ID.  Otherwise
333	 * we have to revoke it and remove it from all the lists
334	 * it has been added to, and return an invalid id.
335	 */
336err:
337	if (ret != 0 && id != DB_LOGFILEID_INVALID) {
338		(void)__dbreg_revoke_id(dbp, 1, id);
339		id = DB_LOGFILEID_INVALID;
340	}
341	*idp = id;
342	return (ret);
343}
344
345/*
346 * __dbreg_assign_id --
347 *	Assign a particular dbreg id to this database handle.
348 *
349 * PUBLIC: int __dbreg_assign_id __P((DB *, int32_t));
350 */
351int
352__dbreg_assign_id(dbp, id)
353	DB *dbp;
354	int32_t id;
355{
356	DB *close_dbp;
357	DB_LOG *dblp;
358	ENV *env;
359	FNAME *close_fnp, *fnp;
360	LOG *lp;
361	int ret;
362
363	env = dbp->env;
364	dblp = env->lg_handle;
365	lp = dblp->reginfo.primary;
366	fnp = dbp->log_filename;
367
368	close_dbp = NULL;
369	close_fnp = NULL;
370
371	/* The mtx_filelist protects the FNAME list and id management. */
372	MUTEX_LOCK(env, lp->mtx_filelist);
373
374	/* We should only call this on DB handles that have no ID. */
375	DB_ASSERT(env, fnp->id == DB_LOGFILEID_INVALID);
376
377	/*
378	 * Make sure there isn't already a file open with this ID. There can
379	 * be in recovery, if we're recovering across a point where an ID got
380	 * reused.
381	 */
382	if (__dbreg_id_to_fname(dblp, id, 1, &close_fnp) == 0) {
383		/*
384		 * We want to save off any dbp we have open with this id.  We
385		 * can't safely close it now, because we hold the mtx_filelist,
386		 * but we should be able to rely on it being open in this
387		 * process, and we're running recovery, so no other thread
388		 * should muck with it if we just put off closing it until
389		 * we're ready to return.
390		 *
391		 * Once we have the dbp, revoke its id;  we're about to
392		 * reuse it.
393		 */
394		ret = __dbreg_id_to_db(env, NULL, &close_dbp, id, 0);
395		if (ret == ENOENT) {
396			ret = 0;
397			goto cont;
398		} else if (ret != 0)
399			goto err;
400
401		if ((ret = __dbreg_revoke_id(close_dbp, 1,
402		    DB_LOGFILEID_INVALID)) != 0)
403			goto err;
404	}
405
406	/*
407	 * Remove this ID from the free list, if it's there, and make sure
408	 * we don't allocate it anew.
409	 */
410cont:	if ((ret = __dbreg_pluck_id(env, id)) != 0)
411		goto err;
412	if (id >= lp->fid_max)
413		lp->fid_max = id + 1;
414
415	/* Now go ahead and assign the id to our dbp. */
416	fnp->id = id;
417	/* If the file is durable (i.e., not, not-durable), mark it as such. */
418	if (!F_ISSET(dbp, DB_AM_NOT_DURABLE))
419		F_SET(fnp, DB_FNAME_DURABLE);
420	SH_TAILQ_INSERT_HEAD(&lp->fq, fnp, q, __fname);
421
422	/*
423	 * If we get an error adding the dbentry, revoke the id.
424	 * We void the return value since we want to retain and
425	 * return the original error in ret anyway.
426	 */
427	if ((ret = __dbreg_add_dbentry(env, dblp, dbp, id)) != 0)
428		(void)__dbreg_revoke_id(dbp, 1, id);
429
430err:	MUTEX_UNLOCK(env, lp->mtx_filelist);
431
432	/* There's nothing useful that our caller can do if this close fails. */
433	if (close_dbp != NULL)
434		(void)__db_close(close_dbp, NULL, DB_NOSYNC);
435
436	return (ret);
437}
438
439/*
440 * __dbreg_revoke_id --
441 *	Take a log id away from a dbp, in preparation for closing it,
442 *	but without logging the close.
443 *
444 * PUBLIC: int __dbreg_revoke_id __P((DB *, int, int32_t));
445 */
446int
447__dbreg_revoke_id(dbp, have_lock, force_id)
448	DB *dbp;
449	int have_lock;
450	int32_t force_id;
451{
452	DB_REP *db_rep;
453	ENV *env;
454	int push;
455
456	env = dbp->env;
457
458	/*
459	 * If we are not in recovery but the file was opened for a recovery
460	 * operation, then this process aborted a transaction for another
461	 * process and the id may still be in use, so don't reuse this id.
462	 * If our fid generation in replication has changed, this fid
463	 * should not be reused
464	 */
465	db_rep = env->rep_handle;
466	push = (!F_ISSET(dbp, DB_AM_RECOVER) || IS_RECOVERING(env)) &&
467	    (!REP_ON(env) || ((REP *)db_rep->region)->gen == dbp->fid_gen);
468
469	return (__dbreg_revoke_id_int(dbp->env,
470	      dbp->log_filename, have_lock, push, force_id));
471}
472/*
473 * __dbreg_revoke_id_int --
474 *	Revoke a log, in preparation for closing it, but without logging
475 *	the close.
476 *
477 * PUBLIC: int __dbreg_revoke_id_int
478 * PUBLIC:     __P((ENV *, FNAME *, int, int, int32_t));
479 */
480int
481__dbreg_revoke_id_int(env, fnp, have_lock, push, force_id)
482	ENV *env;
483	FNAME *fnp;
484	int have_lock, push;
485	int32_t force_id;
486{
487	DB_LOG *dblp;
488	LOG *lp;
489	int32_t id;
490	int ret;
491
492	dblp = env->lg_handle;
493	lp = dblp->reginfo.primary;
494	ret = 0;
495
496	/* If we lack an ID, this is a null-op. */
497	if (fnp == NULL)
498		return (0);
499
500	/*
501	 * If we have a force_id, we had an error after allocating
502	 * the id, and putting it on the fq list, but before we
503	 * finished setting up fnp.  So, if we have a force_id use it.
504	 */
505	if (force_id != DB_LOGFILEID_INVALID)
506		id = force_id;
507	else if (fnp->id == DB_LOGFILEID_INVALID) {
508		if (fnp->old_id == DB_LOGFILEID_INVALID)
509			return (0);
510		id = fnp->old_id;
511	} else
512		id = fnp->id;
513	if (!have_lock)
514		MUTEX_LOCK(env, lp->mtx_filelist);
515
516	fnp->id = DB_LOGFILEID_INVALID;
517	fnp->old_id = DB_LOGFILEID_INVALID;
518
519	/* Remove the FNAME from the list of open files. */
520	SH_TAILQ_REMOVE(&lp->fq, fnp, q, __fname);
521
522	/*
523	 * This FNAME may be for a DBP which is already closed.  Its ID may
524	 * still be in use by an aborting transaction.  If not,
525	 * remove this id from the dbentry table and push it onto the
526	 * free list.
527	 */
528	if (!F_ISSET(fnp, DB_FNAME_CLOSED) &&
529	    (ret = __dbreg_rem_dbentry(dblp, id)) == 0 && push)
530		ret = __dbreg_push_id(env, id);
531
532	if (!have_lock)
533		MUTEX_UNLOCK(env, lp->mtx_filelist);
534	return (ret);
535}
536
537/*
538 * __dbreg_close_id --
539 *	Take a dbreg id away from a dbp that we're closing, and log
540 * the unregistry if the refcount goes to 0.
541 *
542 * PUBLIC: int __dbreg_close_id __P((DB *, DB_TXN *, u_int32_t));
543 */
544int
545__dbreg_close_id(dbp, txn, op)
546	DB *dbp;
547	DB_TXN *txn;
548	u_int32_t op;
549{
550	DB_LOG *dblp;
551	ENV *env;
552	FNAME *fnp;
553	LOG *lp;
554	int ret, t_ret;
555
556	env = dbp->env;
557	dblp = env->lg_handle;
558	lp = dblp->reginfo.primary;
559	fnp = dbp->log_filename;
560
561	/* If we lack an ID, this is a null-op. */
562	if (fnp == NULL)
563		return (0);
564
565	if (fnp->id == DB_LOGFILEID_INVALID) {
566		ret = __dbreg_revoke_id(dbp, 0, DB_LOGFILEID_INVALID);
567		goto done;
568	}
569
570	/*
571	 * If we are the last reference to this db then we need to log it
572	 * as closed.  Otherwise the last transaction will do the logging.
573	 * Remove the DBP from the db entry table since it can nolonger
574	 * be used.  If we abort it will have to be reopened.
575	 */
576	ret = 0;
577	DB_ASSERT(env, fnp->txn_ref > 0);
578	if (fnp->txn_ref > 1) {
579		MUTEX_LOCK(env, dbp->mutex);
580		if (fnp->txn_ref > 1) {
581			if (!F_ISSET(fnp, DB_FNAME_CLOSED) &&
582			    (t_ret = __dbreg_rem_dbentry(
583			    env->lg_handle, fnp->id)) != 0 && ret == 0)
584				ret = t_ret;
585
586			/*
587			 * The DB handle has been closed in the logging system.
588			 * Transactions may still have a ref to this name.
589			 * Mark it so that if recovery reopens the file id
590			 * the transaction will not close the wrong handle.
591			 */
592			F_SET(fnp, DB_FNAME_CLOSED);
593			fnp->txn_ref--;
594			MUTEX_UNLOCK(env, dbp->mutex);
595			/* The mutex now lives only in the FNAME. */
596			dbp->mutex = MUTEX_INVALID;
597			dbp->log_filename = NULL;
598			goto no_log;
599		}
600	}
601	MUTEX_LOCK(env, lp->mtx_filelist);
602
603	if ((ret = __dbreg_log_close(env, fnp, txn, op)) != 0)
604		goto err;
605	ret = __dbreg_revoke_id(dbp, 1, DB_LOGFILEID_INVALID);
606
607err:	MUTEX_UNLOCK(env, lp->mtx_filelist);
608
609done:	if ((t_ret = __dbreg_teardown(dbp)) != 0 && ret == 0)
610		ret = t_ret;
611no_log:
612	return (ret);
613}
614/*
615 * __dbreg_close_id_int --
616 *	Close down a dbreg id and log the unregistry.  This is called only
617 * when a transaction has the last ref to the fname.
618 *
619 * PUBLIC: int __dbreg_close_id_int __P((ENV *, FNAME *, u_int32_t, int));
620 */
621int
622__dbreg_close_id_int(env, fnp, op, locked)
623	ENV *env;
624	FNAME *fnp;
625	u_int32_t op;
626	int locked;
627{
628	DB_LOG *dblp;
629	LOG *lp;
630	int ret, t_ret;
631
632	DB_ASSERT(env, fnp->txn_ref == 1);
633	dblp = env->lg_handle;
634	lp = dblp->reginfo.primary;
635
636	if (fnp->id == DB_LOGFILEID_INVALID)
637		return (__dbreg_revoke_id_int(env,
638		     fnp, locked, 1, DB_LOGFILEID_INVALID));
639
640	if (F_ISSET(fnp, DB_FNAME_RECOVER))
641		return (__dbreg_close_file(env, fnp));
642	/*
643	 * If log_close fails then it will mark the name DB_FNAME_NOTLOGGED
644	 * and the id must persist.
645	 */
646	if (!locked)
647		MUTEX_LOCK(env, lp->mtx_filelist);
648	if ((ret = __dbreg_log_close(env, fnp, NULL, op)) != 0)
649		goto err;
650
651	ret = __dbreg_revoke_id_int(env, fnp, 1, 1, DB_LOGFILEID_INVALID);
652
653err:	if (!locked)
654		MUTEX_UNLOCK(env, lp->mtx_filelist);
655
656	if ((t_ret = __dbreg_teardown_int(env, fnp)) != 0 && ret == 0)
657		ret = t_ret;
658	return (ret);
659}
660
661/*
662 * __dbreg_failchk --
663 *
664 * Look for entries that belong to dead processes and either close them
665 * out or, if there are pending transactions, just remove the mutex which
666 * will get discarded later.
667 *
668 * PUBLIC: int __dbreg_failchk __P((ENV *));
669 */
670int
671__dbreg_failchk(env)
672	ENV *env;
673{
674	DB_ENV *dbenv;
675	DB_LOG *dblp;
676	FNAME *fnp, *nnp;
677	LOG *lp;
678	int ret, t_ret;
679	char buf[DB_THREADID_STRLEN];
680
681	if ((dblp = env->lg_handle) == NULL)
682		return (0);
683
684	lp = dblp->reginfo.primary;
685	dbenv = env->dbenv;
686	ret = 0;
687
688	MUTEX_LOCK(env, lp->mtx_filelist);
689	for (fnp = SH_TAILQ_FIRST(&lp->fq, __fname); fnp != NULL; fnp = nnp) {
690		nnp = SH_TAILQ_NEXT(fnp, q, __fname);
691		if (dbenv->is_alive(dbenv, fnp->pid, 0, DB_MUTEX_PROCESS_ONLY))
692			continue;
693		MUTEX_LOCK(env, fnp->mutex);
694		__db_msg(env,
695		    "Freeing log information for process: %s, (ref %lu)",
696		    dbenv->thread_id_string(dbenv, fnp->pid, 0, buf),
697		    (u_long)fnp->txn_ref);
698		if (fnp->txn_ref > 1 || F_ISSET(fnp, DB_FNAME_CLOSED)) {
699			if (!F_ISSET(fnp, DB_FNAME_CLOSED)) {
700				fnp->txn_ref--;
701				F_SET(fnp, DB_FNAME_CLOSED);
702			}
703			MUTEX_UNLOCK(env, fnp->mutex);
704			fnp->mutex = MUTEX_INVALID;
705			fnp->pid = 0;
706		} else {
707			F_SET(fnp, DB_FNAME_CLOSED);
708			if ((t_ret = __dbreg_close_id_int(env,
709			    fnp, DBREG_CLOSE, 1)) && ret == 0)
710				ret = t_ret;
711		}
712	}
713
714	MUTEX_UNLOCK(env, lp->mtx_filelist);
715	return (ret);
716}
717/*
718 * __dbreg_log_close --
719 *
720 * Log a close of a database.  Called when closing a file or when a
721 * replication client is becoming a master.  That closes all the
722 * files it previously had open.
723 *
724 * Assumes caller holds the lp->mutex_filelist lock already.
725 *
726 * PUBLIC: int __dbreg_log_close __P((ENV *, FNAME *,
727 * PUBLIC:    DB_TXN *, u_int32_t));
728 */
729int
730__dbreg_log_close(env, fnp, txn, op)
731	ENV *env;
732	FNAME *fnp;
733	DB_TXN *txn;
734	u_int32_t op;
735{
736	DBT fid_dbt, r_name, *dbtp;
737	DB_LOG *dblp;
738	DB_LSN r_unused;
739	int ret;
740
741	dblp = env->lg_handle;
742	ret = 0;
743
744	if (fnp->fname_off == INVALID_ROFF)
745		dbtp = NULL;
746	else {
747		memset(&r_name, 0, sizeof(r_name));
748		r_name.data = R_ADDR(&dblp->reginfo, fnp->fname_off);
749		r_name.size = (u_int32_t)strlen((char *)r_name.data) + 1;
750		dbtp = &r_name;
751	}
752	memset(&fid_dbt, 0, sizeof(fid_dbt));
753	fid_dbt.data = fnp->ufid;
754	fid_dbt.size = DB_FILE_ID_LEN;
755	if ((ret = __dbreg_register_log(env, txn, &r_unused,
756	    F_ISSET(fnp, DB_FNAME_DURABLE) ? 0 : DB_LOG_NOT_DURABLE,
757	    op, dbtp, &fid_dbt, fnp->id,
758	    fnp->s_type, fnp->meta_pgno, TXN_INVALID)) != 0) {
759		/*
760		 * We are trying to close, but the log write failed.
761		 * Unfortunately, close needs to plow forward, because
762		 * the application can't do anything with the handle.
763		 * Make the entry in the shared memory region so that
764		 * when we close the environment, we know that this
765		 * happened.  Also, make sure we remove this from the
766		 * per-process table, so that we don't try to close it
767		 * later.
768		 */
769		F_SET(fnp, DB_FNAME_NOTLOGGED);
770		(void)__dbreg_rem_dbentry(dblp, fnp->id);
771	}
772	return (ret);
773}
774
775/*
776 * __dbreg_push_id and __dbreg_pop_id --
777 *	Dbreg ids from closed files are kept on a stack in shared memory
778 * for recycling.  (We want to reuse them as much as possible because each
779 * process keeps open files in an array by ID.)  Push them to the stack and
780 * pop them from it, managing memory as appropriate.
781 *
782 * The stack is protected by the mtx_filelist, and both functions assume it
783 * is already locked.
784 */
785static int
786__dbreg_push_id(env, id)
787	ENV *env;
788	int32_t id;
789{
790	DB_LOG *dblp;
791	LOG *lp;
792	REGINFO *infop;
793	int32_t *stack, *newstack;
794	int ret;
795
796	dblp = env->lg_handle;
797	infop = &dblp->reginfo;
798	lp = infop->primary;
799
800	if (id == lp->fid_max - 1) {
801		lp->fid_max--;
802		return (0);
803	}
804
805	/* Check if we have room on the stack. */
806	if (lp->free_fid_stack == INVALID_ROFF ||
807	    lp->free_fids_alloced <= lp->free_fids + 1) {
808		LOG_SYSTEM_LOCK(env);
809		if ((ret = __env_alloc(infop,
810		    (lp->free_fids_alloced + 20) * sizeof(u_int32_t),
811		    &newstack)) != 0) {
812			LOG_SYSTEM_UNLOCK(env);
813			return (ret);
814		}
815
816		if (lp->free_fid_stack != INVALID_ROFF) {
817			stack = R_ADDR(infop, lp->free_fid_stack);
818			memcpy(newstack, stack,
819			    lp->free_fids_alloced * sizeof(u_int32_t));
820			__env_alloc_free(infop, stack);
821		}
822		lp->free_fid_stack = R_OFFSET(infop, newstack);
823		lp->free_fids_alloced += 20;
824		LOG_SYSTEM_UNLOCK(env);
825	}
826
827	stack = R_ADDR(infop, lp->free_fid_stack);
828	stack[lp->free_fids++] = id;
829	return (0);
830}
831
832static int
833__dbreg_pop_id(env, id)
834	ENV *env;
835	int32_t *id;
836{
837	DB_LOG *dblp;
838	LOG *lp;
839	int32_t *stack;
840
841	dblp = env->lg_handle;
842	lp = dblp->reginfo.primary;
843
844	/* Do we have anything to pop? */
845	if (lp->free_fid_stack != INVALID_ROFF && lp->free_fids > 0) {
846		stack = R_ADDR(&dblp->reginfo, lp->free_fid_stack);
847		*id = stack[--lp->free_fids];
848	} else
849		*id = DB_LOGFILEID_INVALID;
850
851	return (0);
852}
853
854/*
855 * __dbreg_pluck_id --
856 *	Remove a particular dbreg id from the stack of free ids.  This is
857 * used when we open a file, as in recovery, with a specific ID that might
858 * be on the stack.
859 *
860 * Returns success whether or not the particular id was found, and like
861 * push and pop, assumes that the mtx_filelist is locked.
862 */
863static int
864__dbreg_pluck_id(env, id)
865	ENV *env;
866	int32_t id;
867{
868	DB_LOG *dblp;
869	LOG *lp;
870	int32_t *stack;
871	u_int i;
872
873	dblp = env->lg_handle;
874	lp = dblp->reginfo.primary;
875
876	if (id >= lp->fid_max)
877		return (0);
878
879	/* Do we have anything to look at? */
880	if (lp->free_fid_stack != INVALID_ROFF) {
881		stack = R_ADDR(&dblp->reginfo, lp->free_fid_stack);
882		for (i = 0; i < lp->free_fids; i++)
883			if (id == stack[i]) {
884				/*
885				 * Found it.  Overwrite it with the top
886				 * id (which may harmlessly be itself),
887				 * and shorten the stack by one.
888				 */
889				stack[i] = stack[lp->free_fids - 1];
890				lp->free_fids--;
891				return (0);
892			}
893	}
894
895	return (0);
896}
897
898/*
899 * __dbreg_log_id --
900 *	Used for in-memory named files.  They are created in mpool and
901 * are given id's early in the open process so that we can read and
902 * create pages in the mpool for the files.  However, at the time that
903 * the mpf is created, the file may not be fully created and/or its
904 * meta-data may not be fully known, so we can't do a full dbregister.
905 * This is a routine exported that will log a complete dbregister
906 * record that will allow for both recovery and replication.
907 *
908 * PUBLIC: int __dbreg_log_id __P((DB *, DB_TXN *, int32_t, int));
909 */
910int
911__dbreg_log_id(dbp, txn, id, needlock)
912	DB *dbp;
913	DB_TXN *txn;
914	int32_t id;
915	int needlock;
916{
917	DBT fid_dbt, r_name;
918	DB_LOG *dblp;
919	DB_LSN unused;
920	ENV *env;
921	FNAME *fnp;
922	LOG *lp;
923	u_int32_t op;
924	int ret;
925
926	env = dbp->env;
927	dblp = env->lg_handle;
928	lp = dblp->reginfo.primary;
929	fnp = dbp->log_filename;
930
931	/* Verify that the fnp has been initialized. */
932	if (fnp->s_type == DB_UNKNOWN) {
933		memcpy(fnp->ufid, dbp->fileid, DB_FILE_ID_LEN);
934		fnp->s_type = dbp->type;
935	}
936
937	/*
938	 * Log the registry.  We should only request a new ID in situations
939	 * where logging is reasonable.
940	 */
941	memset(&fid_dbt, 0, sizeof(fid_dbt));
942	memset(&r_name, 0, sizeof(r_name));
943
944	if (needlock)
945		MUTEX_LOCK(env, lp->mtx_filelist);
946
947	if (fnp->fname_off != INVALID_ROFF) {
948		r_name.data = R_ADDR(&dblp->reginfo, fnp->fname_off);
949		r_name.size = (u_int32_t)strlen((char *)r_name.data) + 1;
950	}
951
952	fid_dbt.data = dbp->fileid;
953	fid_dbt.size = DB_FILE_ID_LEN;
954
955	op = !F_ISSET(dbp, DB_AM_OPEN_CALLED) ? DBREG_PREOPEN :
956	    (F_ISSET(dbp, DB_AM_INMEM) ? DBREG_REOPEN : DBREG_OPEN);
957	ret = __dbreg_register_log(env, txn, &unused,
958	    F_ISSET(dbp, DB_AM_NOT_DURABLE) ? DB_LOG_NOT_DURABLE : 0,
959	    op, r_name.size == 0 ? NULL : &r_name, &fid_dbt, id,
960	    fnp->s_type, fnp->meta_pgno, fnp->create_txnid);
961
962	if (needlock)
963		MUTEX_UNLOCK(env, lp->mtx_filelist);
964
965	return (ret);
966}
967