1/*-
2 * See the file LICENSE for redistribution information.
3 *
4 * Copyright (c) 1996,2008 Oracle.  All rights reserved.
5 *
6 * $Id: mp_method.c,v 12.61 2008/03/13 15:21:21 mbrey Exp $
7 */
8
9#include "db_config.h"
10
11#include "db_int.h"
12#include "dbinc/mp.h"
13#include "dbinc/db_page.h"
14#include "dbinc/hash.h"
15
16/*
17 * __memp_env_create --
18 *	Mpool specific creation of the DB_ENV structure.
19 *
20 * PUBLIC: int __memp_env_create __P((DB_ENV *));
21 */
22int
23__memp_env_create(dbenv)
24	DB_ENV *dbenv;
25{
26	/*
27	 * !!!
28	 * Our caller has not yet had the opportunity to reset the panic
29	 * state or turn off mutex locking, and so we can neither check
30	 * the panic state or acquire a mutex in the DB_ENV create path.
31	 *
32	 * We default to 32 8K pages.  We don't default to a flat 256K, because
33	 * some systems require significantly more memory to hold 32 pages than
34	 * others.  For example, HP-UX with POSIX pthreads needs 88 bytes for
35	 * a POSIX pthread mutex and almost 200 bytes per buffer header, while
36	 * Solaris needs 24 and 52 bytes for the same structures.  The minimum
37	 * number of hash buckets is 37.  These contain a mutex also.
38	 */
39	dbenv->mp_bytes = dbenv->mp_max_bytes =
40	    32 * ((8 * 1024) + sizeof(BH)) + 37 * sizeof(DB_MPOOL_HASH);
41	dbenv->mp_ncache = 1;
42
43	return (0);
44}
45
46/*
47 * __memp_env_destroy --
48 *	Mpool specific destruction of the DB_ENV structure.
49 *
50 * PUBLIC: void __memp_env_destroy __P((DB_ENV *));
51 */
52void
53__memp_env_destroy(dbenv)
54	DB_ENV *dbenv;
55{
56	COMPQUIET(dbenv, NULL);
57}
58
59/*
60 * __memp_get_cachesize --
61 *	{DB_ENV,DB}->get_cachesize.
62 *
63 * PUBLIC: int __memp_get_cachesize
64 * PUBLIC:         __P((DB_ENV *, u_int32_t *, u_int32_t *, int *));
65 */
66int
67__memp_get_cachesize(dbenv, gbytesp, bytesp, ncachep)
68	DB_ENV *dbenv;
69	u_int32_t *gbytesp, *bytesp;
70	int *ncachep;
71{
72	ENV *env;
73	MPOOL *mp;
74
75	env = dbenv->env;
76
77	ENV_NOT_CONFIGURED(env,
78	    env->mp_handle, "DB_ENV->get_cachesize", DB_INIT_MPOOL);
79
80	if (MPOOL_ON(env)) {
81		/* Cannot be set after open, no lock required to read. */
82		mp = env->mp_handle->reginfo[0].primary;
83		if (gbytesp != NULL)
84			*gbytesp = mp->stat.st_gbytes;
85		if (bytesp != NULL)
86			*bytesp = mp->stat.st_bytes;
87		if (ncachep != NULL)
88			*ncachep = (int)mp->nreg;
89	} else {
90		if (gbytesp != NULL)
91			*gbytesp = dbenv->mp_gbytes;
92		if (bytesp != NULL)
93			*bytesp = dbenv->mp_bytes;
94		if (ncachep != NULL)
95			*ncachep = (int)dbenv->mp_ncache;
96	}
97	return (0);
98}
99
100/*
101 * __memp_set_cachesize --
102 *	{DB_ENV,DB}->set_cachesize.
103 *
104 * PUBLIC: int __memp_set_cachesize __P((DB_ENV *, u_int32_t, u_int32_t, int));
105 */
106int
107__memp_set_cachesize(dbenv, gbytes, bytes, arg_ncache)
108	DB_ENV *dbenv;
109	u_int32_t gbytes, bytes;
110	int arg_ncache;
111{
112	ENV *env;
113	u_int ncache;
114
115	env = dbenv->env;
116
117	/* Normalize the cache count. */
118	ncache = arg_ncache <= 0 ? 1 : (u_int)arg_ncache;
119
120	/*
121	 * You can only store 4GB-1 in an unsigned 32-bit value, so correct for
122	 * applications that specify 4GB cache sizes -- we know what they meant.
123	 */
124	if (sizeof(roff_t) == 4 && gbytes / ncache == 4 && bytes == 0) {
125		--gbytes;
126		bytes = GIGABYTE - 1;
127	} else {
128		gbytes += bytes / GIGABYTE;
129		bytes %= GIGABYTE;
130	}
131
132	/*
133	 * !!!
134	 * With 32-bit region offsets, individual cache regions must be smaller
135	 * than 4GB.  Also, cache sizes larger than 10TB would cause 32-bit
136	 * wrapping in the calculation of the number of hash buckets.  See
137	 * __memp_open for details.
138	 */
139	if (!F_ISSET(env, ENV_OPEN_CALLED)) {
140		if (sizeof(roff_t) <= 4 && gbytes / ncache >= 4) {
141			__db_errx(env,
142			    "individual cache size too large: maximum is 4GB");
143			return (EINVAL);
144		}
145		if (gbytes / ncache > 10000) {
146			__db_errx(env,
147			    "individual cache size too large: maximum is 10TB");
148			return (EINVAL);
149		}
150	}
151
152	/*
153	 * If the application requested less than 500Mb, increase the cachesize
154	 * by 25% and factor in the size of the hash buckets to account for our
155	 * overhead.  (I'm guessing caches over 500Mb are specifically sized,
156	 * that is, it's a large server and the application actually knows how
157	 * much memory is available.  We only document the 25% overhead number,
158	 * not the hash buckets, but I don't see a reason to confuse the issue,
159	 * it shouldn't matter to an application.)
160	 *
161	 * There is a minimum cache size, regardless.
162	 */
163	if (gbytes == 0) {
164		if (bytes < 500 * MEGABYTE)
165			bytes += (bytes / 4) + 37 * sizeof(DB_MPOOL_HASH);
166		if (bytes / ncache < DB_CACHESIZE_MIN)
167			bytes = ncache * DB_CACHESIZE_MIN;
168	}
169
170	if (F_ISSET(env, ENV_OPEN_CALLED))
171		return (__memp_resize(env->mp_handle, gbytes, bytes));
172
173	dbenv->mp_gbytes = gbytes;
174	dbenv->mp_bytes = bytes;
175	dbenv->mp_ncache = ncache;
176
177	return (0);
178}
179
180/*
181 * __memp_set_config --
182 *	Set the cache subsystem configuration.
183 *
184 * PUBLIC: int __memp_set_config __P((DB_ENV *, u_int32_t, int));
185 */
186int
187__memp_set_config(dbenv, which, on)
188	DB_ENV *dbenv;
189	u_int32_t which;
190	int on;
191{
192	DB_MPOOL *dbmp;
193	ENV *env;
194	MPOOL *mp;
195
196	env = dbenv->env;
197
198	ENV_NOT_CONFIGURED(env,
199	    env->mp_handle, "DB_ENV->memp_set_config", DB_INIT_MPOOL);
200
201	switch (which) {
202	case DB_MEMP_SUPPRESS_WRITE:
203	case DB_MEMP_SYNC_INTERRUPT:
204		if (MPOOL_ON(env)) {
205			dbmp = env->mp_handle;
206			mp = dbmp->reginfo[0].primary;
207			if (on)
208				FLD_SET(mp->config_flags, which);
209			else
210				FLD_CLR(mp->config_flags, which);
211		}
212		break;
213	default:
214		return (EINVAL);
215	}
216	return (0);
217}
218
219/*
220 * __memp_get_config --
221 *	Return the cache subsystem configuration.
222 *
223 * PUBLIC: int __memp_get_config __P((DB_ENV *, u_int32_t, int *));
224 */
225int
226__memp_get_config(dbenv, which, onp)
227	DB_ENV *dbenv;
228	u_int32_t which;
229	int *onp;
230{
231	DB_MPOOL *dbmp;
232	ENV *env;
233	MPOOL *mp;
234
235	env = dbenv->env;
236
237	ENV_REQUIRES_CONFIG(env,
238	    env->mp_handle, "DB_ENV->memp_get_config", DB_INIT_MPOOL);
239
240	switch (which) {
241	case DB_MEMP_SUPPRESS_WRITE:
242	case DB_MEMP_SYNC_INTERRUPT:
243		if (MPOOL_ON(env)) {
244			dbmp = env->mp_handle;
245			mp = dbmp->reginfo[0].primary;
246			*onp = FLD_ISSET(mp->config_flags, which) ? 1 : 0;
247		} else
248			*onp = 0;
249		break;
250	default:
251		return (EINVAL);
252	}
253	return (0);
254}
255
256/*
257 * PUBLIC: int __memp_get_mp_max_openfd __P((DB_ENV *, int *));
258 */
259int
260__memp_get_mp_max_openfd(dbenv, maxopenfdp)
261	DB_ENV *dbenv;
262	int *maxopenfdp;
263{
264	DB_MPOOL *dbmp;
265	DB_THREAD_INFO *ip;
266	ENV *env;
267	MPOOL *mp;
268
269	env = dbenv->env;
270
271	ENV_NOT_CONFIGURED(env,
272	    env->mp_handle, "DB_ENV->get_mp_max_openfd", DB_INIT_MPOOL);
273
274	if (MPOOL_ON(env)) {
275		dbmp = env->mp_handle;
276		mp = dbmp->reginfo[0].primary;
277		ENV_ENTER(env, ip);
278		MPOOL_SYSTEM_LOCK(env);
279		*maxopenfdp = mp->mp_maxopenfd;
280		MPOOL_SYSTEM_UNLOCK(env);
281		ENV_LEAVE(env, ip);
282	} else
283		*maxopenfdp = dbenv->mp_maxopenfd;
284	return (0);
285}
286
287/*
288 * __memp_set_mp_max_openfd --
289 *	Set the maximum number of open fd's when flushing the cache.
290 * PUBLIC: int __memp_set_mp_max_openfd __P((DB_ENV *, int));
291 */
292int
293__memp_set_mp_max_openfd(dbenv, maxopenfd)
294	DB_ENV *dbenv;
295	int maxopenfd;
296{
297	DB_MPOOL *dbmp;
298	DB_THREAD_INFO *ip;
299	ENV *env;
300	MPOOL *mp;
301
302	env = dbenv->env;
303
304	ENV_NOT_CONFIGURED(env,
305	    env->mp_handle, "DB_ENV->set_mp_max_openfd", DB_INIT_MPOOL);
306
307	if (MPOOL_ON(env)) {
308		dbmp = env->mp_handle;
309		mp = dbmp->reginfo[0].primary;
310		ENV_ENTER(env, ip);
311		MPOOL_SYSTEM_LOCK(env);
312		mp->mp_maxopenfd = maxopenfd;
313		MPOOL_SYSTEM_UNLOCK(env);
314		ENV_LEAVE(env, ip);
315	} else
316		dbenv->mp_maxopenfd = maxopenfd;
317	return (0);
318}
319
320/*
321 * PUBLIC: int __memp_get_mp_max_write __P((DB_ENV *, int *, db_timeout_t *));
322 */
323int
324__memp_get_mp_max_write(dbenv, maxwritep, maxwrite_sleepp)
325	DB_ENV *dbenv;
326	int *maxwritep;
327	db_timeout_t *maxwrite_sleepp;
328{
329	DB_MPOOL *dbmp;
330	DB_THREAD_INFO *ip;
331	ENV *env;
332	MPOOL *mp;
333
334	env = dbenv->env;
335
336	ENV_NOT_CONFIGURED(env,
337	    env->mp_handle, "DB_ENV->get_mp_max_write", DB_INIT_MPOOL);
338
339	if (MPOOL_ON(env)) {
340		dbmp = env->mp_handle;
341		mp = dbmp->reginfo[0].primary;
342		ENV_ENTER(env, ip);
343		MPOOL_SYSTEM_LOCK(env);
344		*maxwritep = mp->mp_maxwrite;
345		*maxwrite_sleepp = mp->mp_maxwrite_sleep;
346		MPOOL_SYSTEM_UNLOCK(env);
347		ENV_LEAVE(env, ip);
348	} else {
349		*maxwritep = dbenv->mp_maxwrite;
350		*maxwrite_sleepp = dbenv->mp_maxwrite_sleep;
351	}
352	return (0);
353}
354
355/*
356 * __memp_set_mp_max_write --
357 *	Set the maximum continuous I/O count.
358 *
359 * PUBLIC: int __memp_set_mp_max_write __P((DB_ENV *, int, db_timeout_t));
360 */
361int
362__memp_set_mp_max_write(dbenv, maxwrite, maxwrite_sleep)
363	DB_ENV *dbenv;
364	int maxwrite;
365	db_timeout_t maxwrite_sleep;
366{
367	DB_MPOOL *dbmp;
368	DB_THREAD_INFO *ip;
369	ENV *env;
370	MPOOL *mp;
371
372	env = dbenv->env;
373
374	ENV_NOT_CONFIGURED(env,
375	    env->mp_handle, "DB_ENV->get_mp_max_write", DB_INIT_MPOOL);
376
377	if (MPOOL_ON(env)) {
378		dbmp = env->mp_handle;
379		mp = dbmp->reginfo[0].primary;
380		ENV_ENTER(env, ip);
381		MPOOL_SYSTEM_LOCK(env);
382		mp->mp_maxwrite = maxwrite;
383		mp->mp_maxwrite_sleep = maxwrite_sleep;
384		MPOOL_SYSTEM_UNLOCK(env);
385		ENV_LEAVE(env, ip);
386	} else {
387		dbenv->mp_maxwrite = maxwrite;
388		dbenv->mp_maxwrite_sleep = maxwrite_sleep;
389	}
390	return (0);
391}
392
393/*
394 * PUBLIC: int __memp_get_mp_mmapsize __P((DB_ENV *, size_t *));
395 */
396int
397__memp_get_mp_mmapsize(dbenv, mp_mmapsizep)
398	DB_ENV *dbenv;
399	size_t *mp_mmapsizep;
400{
401	DB_MPOOL *dbmp;
402	DB_THREAD_INFO *ip;
403	ENV *env;
404	MPOOL *mp;
405
406	env = dbenv->env;
407
408	ENV_NOT_CONFIGURED(env,
409	    env->mp_handle, "DB_ENV->get_mp_max_mmapsize", DB_INIT_MPOOL);
410
411	if (MPOOL_ON(env)) {
412		dbmp = env->mp_handle;
413		mp = dbmp->reginfo[0].primary;
414		ENV_ENTER(env, ip);
415		MPOOL_SYSTEM_LOCK(env);
416		*mp_mmapsizep = mp->mp_mmapsize;
417		MPOOL_SYSTEM_UNLOCK(env);
418		ENV_LEAVE(env, ip);
419	} else
420		*mp_mmapsizep = dbenv->mp_mmapsize;
421	return (0);
422}
423
424/*
425 * __memp_set_mp_mmapsize --
426 *	DB_ENV->set_mp_mmapsize.
427 *
428 * PUBLIC: int __memp_set_mp_mmapsize __P((DB_ENV *, size_t));
429 */
430int
431__memp_set_mp_mmapsize(dbenv, mp_mmapsize)
432	DB_ENV *dbenv;
433	size_t mp_mmapsize;
434{
435	DB_MPOOL *dbmp;
436	DB_THREAD_INFO *ip;
437	ENV *env;
438	MPOOL *mp;
439
440	env = dbenv->env;
441
442	ENV_NOT_CONFIGURED(env,
443	    env->mp_handle, "DB_ENV->get_mp_max_mmapsize", DB_INIT_MPOOL);
444
445	if (MPOOL_ON(env)) {
446		dbmp = env->mp_handle;
447		mp = dbmp->reginfo[0].primary;
448		ENV_ENTER(env, ip);
449		MPOOL_SYSTEM_LOCK(env);
450		mp->mp_mmapsize = mp_mmapsize;
451		MPOOL_SYSTEM_UNLOCK(env);
452		ENV_LEAVE(env, ip);
453	} else
454		dbenv->mp_mmapsize = mp_mmapsize;
455	return (0);
456}
457
458/*
459 * __memp_nameop
460 *	Remove or rename a file in the pool.
461 *
462 * PUBLIC: int __memp_nameop __P((ENV *,
463 * PUBLIC:     u_int8_t *, const char *, const char *, const char *, int));
464 *
465 * XXX
466 * Undocumented interface: DB private.
467 */
468int
469__memp_nameop(env, fileid, newname, fullold, fullnew, inmem)
470	ENV *env;
471	u_int8_t *fileid;
472	const char *newname, *fullold, *fullnew;
473	int inmem;
474{
475	DB_MPOOL *dbmp;
476	DB_MPOOL_HASH *hp, *nhp;
477	MPOOL *mp;
478	MPOOLFILE *mfp;
479	roff_t newname_off;
480	u_int32_t bucket;
481	int locked, ret;
482	size_t nlen;
483	void *p;
484
485#undef	op_is_remove
486#define	op_is_remove	(newname == NULL)
487
488	COMPQUIET(bucket, 0);
489	COMPQUIET(hp, NULL);
490	COMPQUIET(newname_off, 0);
491	COMPQUIET(nlen, 0);
492
493	dbmp = NULL;
494	mfp = NULL;
495	nhp = NULL;
496	p = NULL;
497	locked = ret = 0;
498
499	if (!MPOOL_ON(env))
500		goto fsop;
501
502	dbmp = env->mp_handle;
503	mp = dbmp->reginfo[0].primary;
504	hp = R_ADDR(dbmp->reginfo, mp->ftab);
505
506	if (!op_is_remove) {
507		nlen = strlen(newname);
508		if ((ret = __memp_alloc(dbmp, dbmp->reginfo,
509		    NULL,  nlen + 1, &newname_off, &p)) != 0)
510			return (ret);
511		memcpy(p, newname, nlen + 1);
512	}
513
514	/*
515	 * Remove or rename a file that the mpool might know about.  We assume
516	 * that the fop layer has the file locked for exclusive access, so we
517	 * don't worry about locking except for the mpool mutexes.  Checkpoint
518	 * can happen at any time, independent of file locking, so we have to
519	 * do the actual unlink or rename system call while holding
520	 * all affected buckets locked.
521	 *
522	 * If this is a rename and this is a memory file then we need
523	 * to make sure that the new name does not exist.  Since we
524	 * are locking two buckets lock them in ascending order.
525	 */
526	if (inmem) {
527		DB_ASSERT(env, fullold != NULL);
528		hp += FNBUCKET(fullold, strlen(fullold));
529		if (!op_is_remove) {
530			bucket = FNBUCKET(newname, nlen);
531			nhp = R_ADDR(dbmp->reginfo, mp->ftab);
532			nhp += bucket;
533		}
534	} else
535		hp += FNBUCKET(fileid, DB_FILE_ID_LEN);
536
537	if (nhp != NULL && nhp < hp)
538		MUTEX_LOCK(env, nhp->mtx_hash);
539	MUTEX_LOCK(env, hp->mtx_hash);
540	if (nhp != NULL && nhp > hp)
541		MUTEX_LOCK(env, nhp->mtx_hash);
542	locked = 1;
543
544	if (!op_is_remove && inmem) {
545		SH_TAILQ_FOREACH(mfp, &nhp->hash_bucket, q, __mpoolfile)
546			if (!mfp->deadfile &&
547			    mfp->no_backing_file && strcmp(newname,
548			    R_ADDR(dbmp->reginfo, mfp->path_off)) == 0)
549				break;
550		if (mfp != NULL) {
551			ret = EEXIST;
552			goto err;
553		}
554	}
555
556	/*
557	 * Find the file -- if mpool doesn't know about this file, that may
558	 * not be an error.
559	 */
560	SH_TAILQ_FOREACH(mfp, &hp->hash_bucket, q, __mpoolfile) {
561		/* Ignore non-active files. */
562		if (mfp->deadfile || F_ISSET(mfp, MP_TEMP))
563			continue;
564
565		/* Try to match on fileid. */
566		if (memcmp(fileid, R_ADDR(
567		    dbmp->reginfo, mfp->fileid_off), DB_FILE_ID_LEN) != 0)
568			continue;
569
570		break;
571	}
572
573	if (mfp == NULL) {
574		if (inmem) {
575			ret = ENOENT;
576			goto err;
577		}
578		goto fsop;
579	}
580
581	if (op_is_remove) {
582		MUTEX_LOCK(env, mfp->mutex);
583		/*
584		 * In-memory dbs have an artificially incremented ref count so
585		 * they do not get reclaimed as long as they exist.  Since we
586		 * are now deleting the database, we need to dec that count.
587		 */
588		if (mfp->no_backing_file)
589			mfp->mpf_cnt--;
590		mfp->deadfile = 1;
591		MUTEX_UNLOCK(env, mfp->mutex);
592	} else {
593		/*
594		 * Else, it's a rename.  We've allocated memory for the new
595		 * name.  Swap it with the old one.  If it's in memory we
596		 * need to move it the right bucket.
597		 */
598		p = R_ADDR(dbmp->reginfo, mfp->path_off);
599		mfp->path_off = newname_off;
600
601		if (inmem && hp != nhp) {
602			DB_ASSERT(env, nhp != NULL);
603			SH_TAILQ_REMOVE(&hp->hash_bucket, mfp, q, __mpoolfile);
604			mfp->bucket = bucket;
605			SH_TAILQ_INSERT_TAIL(&nhp->hash_bucket, mfp, q);
606		}
607	}
608
609fsop:	/*
610	 * If this is a real file, then mfp could be NULL, because
611	 * mpool isn't turned on, and we still need to do the file ops.
612	 */
613	if (mfp == NULL || !mfp->no_backing_file) {
614		if (op_is_remove) {
615			/*
616			 * !!!
617			 * Replication may ask us to unlink a file that's been
618			 * renamed.  Don't complain if it doesn't exist.
619			 */
620			if ((ret = __os_unlink(env, fullold, 0)) == ENOENT)
621				ret = 0;
622		} else {
623			/*
624			 * Defensive only, fullnew should never be
625			 * NULL.
626			 */
627			DB_ASSERT(env, fullnew != NULL);
628			if (fullnew == NULL) {
629				ret = EINVAL;
630				goto err;
631			}
632			ret = __os_rename(env, fullold, fullnew, 1);
633		}
634	}
635
636	/* Delete the memory we no longer need. */
637err:	if (p != NULL)
638		__memp_free(&dbmp->reginfo[0], NULL, p);
639
640	/* If we have buckets locked, unlock them when done moving files. */
641	if (locked == 1) {
642		MUTEX_UNLOCK(env, hp->mtx_hash);
643		if (nhp != NULL && nhp != hp)
644			MUTEX_UNLOCK(env, nhp->mtx_hash);
645	}
646	return (ret);
647}
648
649/*
650 * __memp_ftruncate __
651 *	Truncate the file.
652 *
653 * PUBLIC: int __memp_ftruncate __P((DB_MPOOLFILE *,
654 * PUBLIC:     DB_THREAD_INFO *, db_pgno_t, u_int32_t));
655 */
656int
657__memp_ftruncate(dbmfp, ip, pgno, flags)
658	DB_MPOOLFILE *dbmfp;
659	DB_THREAD_INFO *ip;
660	db_pgno_t pgno;
661	u_int32_t flags;
662{
663	ENV *env;
664	MPOOLFILE *mfp;
665	void *pagep;
666	db_pgno_t last_pgno, pg;
667	int ret;
668
669	env = dbmfp->env;
670	mfp = dbmfp->mfp;
671
672	MUTEX_LOCK(env, mfp->mutex);
673	last_pgno = mfp->last_pgno;
674	MUTEX_UNLOCK(env, mfp->mutex);
675
676	if (pgno > last_pgno) {
677		if (LF_ISSET(MP_TRUNC_RECOVER))
678			return (0);
679		__db_errx(env, "Truncate beyond the end of file");
680		return (EINVAL);
681	}
682
683	pg = pgno;
684	do {
685		if ((ret = __memp_fget(dbmfp, &pg,
686		    ip, NULL, DB_MPOOL_FREE, &pagep)) != 0)
687			return (ret);
688	} while (pg++ < last_pgno);
689
690	/*
691	 * If we are aborting an extend of a file, the call to __os_truncate
692	 * could extend the file if the new page(s) had not yet been
693	 * written to disk.  We do not want to extend the file to pages
694	 * whose log records are not yet flushed [#14031].  In addition if
695	 * we are out of disk space we can generate an error [#12743].
696	 */
697	MUTEX_LOCK(env, mfp->mutex);
698	if (!F_ISSET(mfp, MP_TEMP) &&
699	    !mfp->no_backing_file && pgno <= mfp->last_flushed_pgno)
700#ifdef HAVE_FTRUNCATE
701		ret = __os_truncate(env,
702		    dbmfp->fhp, pgno, mfp->stat.st_pagesize);
703#else
704		ret = __db_zero_extend(env,
705		    dbmfp->fhp, pgno, mfp->last_pgno, mfp->stat.st_pagesize);
706#endif
707
708	/*
709	 * This set could race with another thread of control that extending
710	 * the file.  It's not a problem because we should have the page
711	 * locked at a higher level of the system.
712	 */
713	if (ret == 0) {
714		mfp->last_pgno = pgno - 1;
715		if (mfp->last_flushed_pgno > mfp->last_pgno)
716			mfp->last_flushed_pgno = mfp->last_pgno;
717	}
718	MUTEX_UNLOCK(env, mfp->mutex);
719
720	return (ret);
721}
722
723#ifdef HAVE_FTRUNCATE
724/*
725 * Support routines for maintaining a sorted freelist while we try to rearrange
726 * and truncate the file.
727 */
728
729/*
730 * __memp_alloc_freelist --
731 *	Allocate mpool space for the freelist.
732 *
733 * PUBLIC: int __memp_alloc_freelist __P((DB_MPOOLFILE *,
734 * PUBLIC:	 u_int32_t, db_pgno_t **));
735 */
736int
737__memp_alloc_freelist(dbmfp, nelems, listp)
738	DB_MPOOLFILE *dbmfp;
739	u_int32_t nelems;
740	db_pgno_t **listp;
741{
742	DB_MPOOL *dbmp;
743	ENV *env;
744	MPOOLFILE *mfp;
745	void *retp;
746	int ret;
747
748	env = dbmfp->env;
749	dbmp = env->mp_handle;
750	mfp = dbmfp->mfp;
751
752	*listp = NULL;
753
754	/*
755	 * These fields are protected because the database layer
756	 * has the metapage locked while manipulating them.
757	 */
758	mfp->free_ref++;
759	if (mfp->free_size != 0)
760		return (EBUSY);
761
762	/* Allocate at least a few slots. */
763	mfp->free_cnt = nelems;
764	if (nelems == 0)
765		nelems = 50;
766
767	if ((ret = __memp_alloc(dbmp, dbmp->reginfo,
768	    NULL, nelems * sizeof(db_pgno_t), &mfp->free_list, &retp)) != 0)
769		return (ret);
770
771	mfp->free_size = nelems * sizeof(db_pgno_t);
772	*listp = retp;
773	return (0);
774}
775
776/*
777 * __memp_free_freelist --
778 *	Free the list.
779 *
780 * PUBLIC: int __memp_free_freelist __P((DB_MPOOLFILE *));
781 */
782int
783__memp_free_freelist(dbmfp)
784	DB_MPOOLFILE *dbmfp;
785{
786	DB_MPOOL *dbmp;
787	ENV *env;
788	MPOOLFILE *mfp;
789
790	env = dbmfp->env;
791	dbmp = env->mp_handle;
792	mfp = dbmfp->mfp;
793
794	DB_ASSERT(env, mfp->free_ref > 0);
795	if (--mfp->free_ref > 0)
796		return (0);
797
798	DB_ASSERT(env, mfp->free_size != 0);
799
800	MPOOL_SYSTEM_LOCK(env);
801	__memp_free(dbmp->reginfo, NULL, R_ADDR(dbmp->reginfo, mfp->free_list));
802	MPOOL_SYSTEM_UNLOCK(env);
803
804	mfp->free_cnt = 0;
805	mfp->free_list = 0;
806	mfp->free_size = 0;
807	return (0);
808}
809
810/*
811 * __memp_get_freelst --
812 *	Return current list.
813 *
814 * PUBLIC: int __memp_get_freelist __P((
815 * PUBLIC:	DB_MPOOLFILE *, u_int32_t *, db_pgno_t **));
816 */
817int
818__memp_get_freelist(dbmfp, nelemp, listp)
819	DB_MPOOLFILE *dbmfp;
820	u_int32_t *nelemp;
821	db_pgno_t **listp;
822{
823	DB_MPOOL *dbmp;
824	ENV *env;
825	MPOOLFILE *mfp;
826
827	env = dbmfp->env;
828	dbmp = env->mp_handle;
829	mfp = dbmfp->mfp;
830
831	if (mfp->free_size == 0) {
832		*nelemp = 0;
833		*listp = NULL;
834	} else {
835		*nelemp = mfp->free_cnt;
836		*listp = R_ADDR(dbmp->reginfo, mfp->free_list);
837	}
838
839	return (0);
840}
841
842/*
843 * __memp_extend_freelist --
844 *	Extend the list.
845 *
846 * PUBLIC: int __memp_extend_freelist __P((
847 * PUBLIC:	DB_MPOOLFILE *, u_int32_t , db_pgno_t **));
848 */
849int
850__memp_extend_freelist(dbmfp, count, listp)
851	DB_MPOOLFILE *dbmfp;
852	u_int32_t count;
853	db_pgno_t **listp;
854{
855	DB_MPOOL *dbmp;
856	ENV *env;
857	MPOOLFILE *mfp;
858	int ret;
859	void *retp;
860
861	env = dbmfp->env;
862	dbmp = env->mp_handle;
863	mfp = dbmfp->mfp;
864
865	if (mfp->free_size == 0)
866		return (EINVAL);
867
868	if (count * sizeof(db_pgno_t) > mfp->free_size) {
869		mfp->free_size =
870		     (size_t)DB_ALIGN(count * sizeof(db_pgno_t), 512);
871		*listp = R_ADDR(dbmp->reginfo, mfp->free_list);
872		if ((ret = __memp_alloc(dbmp, dbmp->reginfo,
873		    NULL, mfp->free_size, &mfp->free_list, &retp)) != 0)
874			return (ret);
875
876		memcpy(retp, *listp, mfp->free_cnt * sizeof(db_pgno_t));
877
878		MPOOL_SYSTEM_LOCK(env);
879		__memp_free(dbmp->reginfo, NULL, *listp);
880		MPOOL_SYSTEM_UNLOCK(env);
881	}
882
883	mfp->free_cnt = count;
884	*listp = R_ADDR(dbmp->reginfo, mfp->free_list);
885
886	return (0);
887}
888#endif
889
890/*
891 * __memp_set_last_pgno -- set the last page of the file
892 *
893 * PUBLIC: void __memp_set_last_pgno __P((DB_MPOOLFILE *, db_pgno_t));
894 */
895void
896__memp_set_last_pgno(dbmfp, pgno)
897	DB_MPOOLFILE *dbmfp;
898	db_pgno_t pgno;
899{
900	dbmfp->mfp->last_pgno = pgno;
901}
902