about summary refs log tree commit diff
path: root/db2/mp/mp_fopen.c
blob: a4cbac8d4e9c7041149043141be3e0f08f29831a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996, 1997, 1998
 *	Sleepycat Software.  All rights reserved.
 */
#include "config.h"

#ifndef lint
static const char sccsid[] = "@(#)mp_fopen.c	10.47 (Sleepycat) 5/4/98";
#endif /* not lint */

#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>

#include <errno.h>
#include <string.h>
#endif

#include "db_int.h"
#include "shqueue.h"
#include "db_shash.h"
#include "mp.h"
#include "common_ext.h"

static int __memp_mf_close __P((DB_MPOOL *, DB_MPOOLFILE *));
static int __memp_mf_open __P((DB_MPOOL *,
    const char *, size_t, db_pgno_t, DB_MPOOL_FINFO *, MPOOLFILE **));

/*
 * memp_fopen --
 *	Open a backing file for the memory pool.
 */
int
memp_fopen(dbmp, path, flags, mode, pagesize, finfop, retp)
	DB_MPOOL *dbmp;
	const char *path;
	u_int32_t flags;
	int mode;
	size_t pagesize;
	DB_MPOOL_FINFO *finfop;
	DB_MPOOLFILE **retp;
{
	int ret;

	/* Validate arguments. */
	if ((ret = __db_fchk(dbmp->dbenv,
	    "memp_fopen", flags, DB_CREATE | DB_NOMMAP | DB_RDONLY)) != 0)
		return (ret);

	/* Require a non-zero pagesize. */
	if (pagesize == 0) {
		__db_err(dbmp->dbenv, "memp_fopen: pagesize not specified");
		return (EINVAL);
	}

	return (__memp_fopen(dbmp,
	    NULL, path, flags, mode, pagesize, 1, finfop, retp));
}

/*
 * __memp_fopen --
 *	Open a backing file for the memory pool; internal version.
 *
 * PUBLIC: int __memp_fopen __P((DB_MPOOL *, MPOOLFILE *, const char *,
 * PUBLIC:    u_int32_t, int, size_t, int, DB_MPOOL_FINFO *, DB_MPOOLFILE **));
 */
int
__memp_fopen(dbmp, mfp, path, flags, mode, pagesize, needlock, finfop, retp)
	DB_MPOOL *dbmp;
	MPOOLFILE *mfp;
	const char *path;
	u_int32_t flags;
	int mode, needlock;
	size_t pagesize;
	DB_MPOOL_FINFO *finfop;
	DB_MPOOLFILE **retp;
{
	DB_ENV *dbenv;
	DB_MPOOLFILE *dbmfp;
	DB_MPOOL_FINFO finfo;
	db_pgno_t last_pgno;
	size_t size;
	u_int32_t mbytes, bytes;
	int ret;
	u_int8_t idbuf[DB_FILE_ID_LEN];
	char *rpath;

	dbenv = dbmp->dbenv;
	ret = 0;
	rpath = NULL;

	/*
	 * If mfp is provided, we take the DB_MPOOL_FINFO information from
	 * the mfp.  We don't bother initializing everything, because some
	 * of them are expensive to acquire.  If no mfp is provided and the
	 * finfop argument is NULL, we default the values.
	 */
	if (finfop == NULL) {
		memset(&finfo, 0, sizeof(finfo));
		if (mfp != NULL) {
			finfo.ftype = mfp->ftype;
			finfo.pgcookie = NULL;
			finfo.fileid = NULL;
			finfo.lsn_offset = mfp->lsn_off;
			finfo.clear_len = mfp->clear_len;
		} else {
			finfo.ftype = 0;
			finfo.pgcookie = NULL;
			finfo.fileid = NULL;
			finfo.lsn_offset = -1;
			finfo.clear_len = 0;
		}
		finfop = &finfo;
	}

	/* Allocate and initialize the per-process structure. */
	if ((dbmfp =
	    (DB_MPOOLFILE *)__db_calloc(1, sizeof(DB_MPOOLFILE))) == NULL) {
		__db_err(dbenv, "memp_fopen: %s", strerror(ENOMEM));
		return (ENOMEM);
	}
	dbmfp->dbmp = dbmp;
	dbmfp->fd = -1;
	if (LF_ISSET(DB_RDONLY))
		F_SET(dbmfp, MP_READONLY);

	if (path == NULL) {
		if (LF_ISSET(DB_RDONLY)) {
			__db_err(dbenv,
			    "memp_fopen: temporary files can't be readonly");
			ret = EINVAL;
			goto err;
		}
		size = 0;
		last_pgno = 0;
	} else {
		/* Get the real name for this file and open it. */
		if ((ret = __db_appname(dbenv,
		    DB_APP_DATA, NULL, path, 0, NULL, &rpath)) != 0)
			goto err;
		if ((ret = __db_open(rpath,
		   LF_ISSET(DB_CREATE | DB_RDONLY),
		   DB_CREATE | DB_RDONLY, mode, &dbmfp->fd)) != 0) {
			__db_err(dbenv, "%s: %s", rpath, strerror(ret));
			goto err;
		}

		/* Don't permit files that aren't a multiple of the pagesize. */
		if ((ret = __db_ioinfo(rpath,
		    dbmfp->fd, &mbytes, &bytes, NULL)) != 0) {
			__db_err(dbenv, "%s: %s", rpath, strerror(ret));
			goto err;
		}
		if (bytes % pagesize) {
			__db_err(dbenv,
			    "%s: file size not a multiple of the pagesize",
			    rpath);
			ret = EINVAL;
			goto err;
		}
		size = mbytes * MEGABYTE + bytes;
		last_pgno = size == 0 ? 0 : (size - 1) / pagesize;

		/*
		 * Get the file id if we weren't given one.  Generated file id's
		 * don't use timestamps, otherwise there'd be no chance of any
		 * other process joining the party.
		 */
		if (finfop->fileid == NULL) {
			if ((ret = __db_fileid(dbenv, rpath, 0, idbuf)) != 0)
				goto err;
			finfop->fileid = idbuf;
		}
	}

	/*
	 * If we weren't provided an underlying shared object to join with,
	 * find/allocate the shared file objects.  Also allocate space for
	 * for the per-process thread lock.
	 */
	if (needlock)
		LOCKREGION(dbmp);

	if (mfp == NULL)
		ret = __memp_mf_open(dbmp,
		    path, pagesize, last_pgno, finfop, &mfp);
	else {
		++mfp->ref;
		ret = 0;
	}
	if (ret == 0 &&
	    F_ISSET(dbmp, MP_LOCKHANDLE) && (ret =
	    __memp_ralloc(dbmp, sizeof(db_mutex_t), NULL, &dbmfp->mutexp)) == 0)
		LOCKINIT(dbmp, dbmfp->mutexp);

	if (needlock)
		UNLOCKREGION(dbmp);
	if (ret != 0)
		goto err;

	dbmfp->mfp = mfp;

	/*
	 * If a file:
	 *	+ is read-only
	 *	+ isn't temporary
	 *	+ doesn't require any pgin/pgout support
	 *	+ the DB_NOMMAP flag wasn't set
	 *	+ and is less than mp_mmapsize bytes in size
	 *
	 * we can mmap it instead of reading/writing buffers.  Don't do error
	 * checking based on the mmap call failure.  We want to do normal I/O
	 * on the file if the reason we failed was because the file was on an
	 * NFS mounted partition, and we can fail in buffer I/O just as easily
	 * as here.
	 *
	 * XXX
	 * We'd like to test to see if the file is too big to mmap.  Since we
	 * don't know what size or type off_t's or size_t's are, or the largest
	 * unsigned integral type is, or what random insanity the local C
	 * compiler will perpetrate, doing the comparison in a portable way is
	 * flatly impossible.  Hope that mmap fails if the file is too large.
	 */
#define	DB_MAXMMAPSIZE	(10 * 1024 * 1024)	/* 10 Mb. */
	if (F_ISSET(mfp, MP_CAN_MMAP)) {
		if (!F_ISSET(dbmfp, MP_READONLY))
			F_CLR(mfp, MP_CAN_MMAP);
		if (path == NULL)
			F_CLR(mfp, MP_CAN_MMAP);
		if (finfop->ftype != 0)
			F_CLR(mfp, MP_CAN_MMAP);
		if (LF_ISSET(DB_NOMMAP))
			F_CLR(mfp, MP_CAN_MMAP);
		if (size > (dbenv == NULL || dbenv->mp_mmapsize == 0 ?
		    DB_MAXMMAPSIZE : dbenv->mp_mmapsize))
			F_CLR(mfp, MP_CAN_MMAP);
	}
	dbmfp->addr = NULL;
	if (F_ISSET(mfp, MP_CAN_MMAP)) {
		dbmfp->len = size;
		if (__db_mapfile(rpath,
		    dbmfp->fd, dbmfp->len, 1, &dbmfp->addr) != 0) {
			dbmfp->addr = NULL;
			F_CLR(mfp, MP_CAN_MMAP);
		}
	}
	if (rpath != NULL)
		FREES(rpath);

	LOCKHANDLE(dbmp, dbmp->mutexp);
	TAILQ_INSERT_TAIL(&dbmp->dbmfq, dbmfp, q);
	UNLOCKHANDLE(dbmp, dbmp->mutexp);

	*retp = dbmfp;
	return (0);

err:	/*
	 * Note that we do not have to free the thread mutex, because we
	 * never get to here after we have successfully allocated it.
	 */
	if (rpath != NULL)
		FREES(rpath);
	if (dbmfp->fd != -1)
		(void)__db_close(dbmfp->fd);
	if (dbmfp != NULL)
		FREE(dbmfp, sizeof(DB_MPOOLFILE));
	return (ret);
}

/*
 * __memp_mf_open --
 *	Open an MPOOLFILE.
 */
static int
__memp_mf_open(dbmp, path, pagesize, last_pgno, finfop, retp)
	DB_MPOOL *dbmp;
	const char *path;
	size_t pagesize;
	db_pgno_t last_pgno;
	DB_MPOOL_FINFO *finfop;
	MPOOLFILE **retp;
{
	MPOOLFILE *mfp;
	int ret;
	void *p;

#define	ISTEMPORARY	(path == NULL)

	/*
	 * Walk the list of MPOOLFILE's, looking for a matching file.
	 * Temporary files can't match previous files.
	 */
	if (!ISTEMPORARY)
		for (mfp = SH_TAILQ_FIRST(&dbmp->mp->mpfq, __mpoolfile);
		    mfp != NULL; mfp = SH_TAILQ_NEXT(mfp, q, __mpoolfile)) {
			if (F_ISSET(mfp, MP_TEMP))
				continue;
			if (!memcmp(finfop->fileid,
			    R_ADDR(dbmp, mfp->fileid_off), DB_FILE_ID_LEN)) {
				if (finfop->clear_len != mfp->clear_len ||
				    finfop->ftype != mfp->ftype ||
				    pagesize != mfp->stat.st_pagesize) {
					__db_err(dbmp->dbenv,
			    "%s: ftype, clear length or pagesize changed",
					    path);
					return (EINVAL);
				}

				/* Found it: increment the reference count. */
				++mfp->ref;
				*retp = mfp;
				return (0);
			}
		}

	/* Allocate a new MPOOLFILE. */
	if ((ret = __memp_ralloc(dbmp, sizeof(MPOOLFILE), NULL, &mfp)) != 0)
		return (ret);
	*retp = mfp;

	/* Initialize the structure. */
	memset(mfp, 0, sizeof(MPOOLFILE));
	mfp->ref = 1;
	mfp->ftype = finfop->ftype;
	mfp->lsn_off = finfop->lsn_offset;
	mfp->clear_len = finfop->clear_len;

	/*
	 * If the user specifies DB_MPOOL_LAST or DB_MPOOL_NEW on a memp_fget,
	 * we have to know the last page in the file.  Figure it out and save
	 * it away.
	 */
	mfp->stat.st_pagesize = pagesize;
	mfp->orig_last_pgno = mfp->last_pgno = last_pgno;

	F_SET(mfp, MP_CAN_MMAP);
	if (ISTEMPORARY)
		F_SET(mfp, MP_TEMP);
	else {
		/* Copy the file path into shared memory. */
		if ((ret = __memp_ralloc(dbmp,
		    strlen(path) + 1, &mfp->path_off, &p)) != 0)
			goto err;
		memcpy(p, path, strlen(path) + 1);

		/* Copy the file identification string into shared memory. */
		if ((ret = __memp_ralloc(dbmp,
		    DB_FILE_ID_LEN, &mfp->fileid_off, &p)) != 0)
			goto err;
		memcpy(p, finfop->fileid, DB_FILE_ID_LEN);
	}

	/* Copy the page cookie into shared memory. */
	if (finfop->pgcookie == NULL || finfop->pgcookie->size == 0) {
		mfp->pgcookie_len = 0;
		mfp->pgcookie_off = 0;
	} else {
		if ((ret = __memp_ralloc(dbmp,
		    finfop->pgcookie->size, &mfp->pgcookie_off, &p)) != 0)
			goto err;
		memcpy(p, finfop->pgcookie->data, finfop->pgcookie->size);
		mfp->pgcookie_len = finfop->pgcookie->size;
	}

	/* Prepend the MPOOLFILE to the list of MPOOLFILE's. */
	SH_TAILQ_INSERT_HEAD(&dbmp->mp->mpfq, mfp, q, __mpoolfile);

	if (0) {
err:		if (mfp->path_off != 0)
			__db_shalloc_free(dbmp->addr,
			    R_ADDR(dbmp, mfp->path_off));
		if (mfp->fileid_off != 0)
			__db_shalloc_free(dbmp->addr,
			    R_ADDR(dbmp, mfp->fileid_off));
		if (mfp != NULL)
			__db_shalloc_free(dbmp->addr, mfp);
		mfp = NULL;
	}
	return (0);
}

/*
 * memp_fclose --
 *	Close a backing file for the memory pool.
 */
int
memp_fclose(dbmfp)
	DB_MPOOLFILE *dbmfp;
{
	DB_MPOOL *dbmp;
	int ret, t_ret;

	dbmp = dbmfp->dbmp;
	ret = 0;

	/* Complain if pinned blocks never returned. */
	if (dbmfp->pinref != 0)
		__db_err(dbmp->dbenv, "%s: close: %lu blocks left pinned",
		    __memp_fn(dbmfp), (u_long)dbmfp->pinref);

	/* Remove the DB_MPOOLFILE structure from the list. */
	LOCKHANDLE(dbmp, dbmp->mutexp);
	TAILQ_REMOVE(&dbmp->dbmfq, dbmfp, q);
	UNLOCKHANDLE(dbmp, dbmp->mutexp);

	/* Close the underlying MPOOLFILE. */
	(void)__memp_mf_close(dbmp, dbmfp);

	/* Discard any mmap information. */
	if (dbmfp->addr != NULL &&
	    (ret = __db_unmapfile(dbmfp->addr, dbmfp->len)) != 0)
		__db_err(dbmp->dbenv,
		    "%s: %s", __memp_fn(dbmfp), strerror(ret));

	/* Close the file; temporary files may not yet have been created. */
	if (dbmfp->fd != -1 && (t_ret = __db_close(dbmfp->fd)) != 0) {
		__db_err(dbmp->dbenv,
		    "%s: %s", __memp_fn(dbmfp), strerror(t_ret));
		if (ret != 0)
			t_ret = ret;
	}

	/* Free memory. */
	if (dbmfp->mutexp != NULL) {
		LOCKREGION(dbmp);
		__db_shalloc_free(dbmp->addr, dbmfp->mutexp);
		UNLOCKREGION(dbmp);
	}

	/* Discard the DB_MPOOLFILE structure. */
	FREE(dbmfp, sizeof(DB_MPOOLFILE));

	return (ret);
}

/*
 * __memp_mf_close --
 *	Close down an MPOOLFILE.
 */
static int
__memp_mf_close(dbmp, dbmfp)
	DB_MPOOL *dbmp;
	DB_MPOOLFILE *dbmfp;
{
	BH *bhp, *nbhp;
	MPOOL *mp;
	MPOOLFILE *mfp;
	size_t mf_offset;

	mp = dbmp->mp;
	mfp = dbmfp->mfp;

	LOCKREGION(dbmp);

	/* If more than a single reference, simply decrement. */
	if (mfp->ref > 1) {
		--mfp->ref;
		goto ret1;
	}

	/*
	 * Move any BH's held by the file to the free list.  We don't free the
	 * memory itself because we may be discarding the memory pool, and it's
	 * fairly expensive to reintegrate the buffers back into the region for
	 * no purpose.
	 */
	mf_offset = R_OFFSET(dbmp, mfp);
	for (bhp = SH_TAILQ_FIRST(&mp->bhq, __bh); bhp != NULL; bhp = nbhp) {
		nbhp = SH_TAILQ_NEXT(bhp, q, __bh);

#ifdef DEBUG_NO_DIRTY
		/* Complain if we find any blocks that were left dirty. */
		if (F_ISSET(bhp, BH_DIRTY))
			__db_err(dbmp->dbenv,
			    "%s: close: pgno %lu left dirty; ref %lu",
			    __memp_fn(dbmfp),
			    (u_long)bhp->pgno, (u_long)bhp->ref);
#endif

		if (bhp->mf_offset == mf_offset) {
			if (F_ISSET(bhp, BH_DIRTY)) {
				++mp->stat.st_page_clean;
				--mp->stat.st_page_dirty;
			}
			__memp_bhfree(dbmp, mfp, bhp, 0);
			SH_TAILQ_INSERT_HEAD(&mp->bhfq, bhp, q, __bh);
		}
	}

	/* Delete from the list of MPOOLFILEs. */
	SH_TAILQ_REMOVE(&mp->mpfq, mfp, q, __mpoolfile);

	/* Free the space. */
	if (mfp->path_off != 0)
		__db_shalloc_free(dbmp->addr, R_ADDR(dbmp, mfp->path_off));
	if (mfp->fileid_off != 0)
		__db_shalloc_free(dbmp->addr, R_ADDR(dbmp, mfp->fileid_off));
	if (mfp->pgcookie_off != 0)
		__db_shalloc_free(dbmp->addr, R_ADDR(dbmp, mfp->pgcookie_off));
	__db_shalloc_free(dbmp->addr, mfp);

ret1:	UNLOCKREGION(dbmp);
	return (0);
}