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bt_open.c revision 1.25
      1  1.25  christos /*	$NetBSD: bt_open.c,v 1.25 2011/04/17 23:12:38 christos Exp $	*/
      2   1.7       cgd 
      3   1.1       cgd /*-
      4   1.6       cgd  * Copyright (c) 1990, 1993, 1994
      5   1.1       cgd  *	The Regents of the University of California.  All rights reserved.
      6   1.1       cgd  *
      7   1.1       cgd  * This code is derived from software contributed to Berkeley by
      8   1.1       cgd  * Mike Olson.
      9   1.1       cgd  *
     10   1.1       cgd  * Redistribution and use in source and binary forms, with or without
     11   1.1       cgd  * modification, are permitted provided that the following conditions
     12   1.1       cgd  * are met:
     13   1.1       cgd  * 1. Redistributions of source code must retain the above copyright
     14   1.1       cgd  *    notice, this list of conditions and the following disclaimer.
     15   1.1       cgd  * 2. Redistributions in binary form must reproduce the above copyright
     16   1.1       cgd  *    notice, this list of conditions and the following disclaimer in the
     17   1.1       cgd  *    documentation and/or other materials provided with the distribution.
     18  1.17       agc  * 3. Neither the name of the University nor the names of its contributors
     19   1.1       cgd  *    may be used to endorse or promote products derived from this software
     20   1.1       cgd  *    without specific prior written permission.
     21   1.1       cgd  *
     22   1.1       cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23   1.1       cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24   1.1       cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25   1.1       cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26   1.1       cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27   1.1       cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28   1.1       cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29   1.1       cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30   1.1       cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31   1.1       cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32   1.1       cgd  * SUCH DAMAGE.
     33   1.1       cgd  */
     34   1.1       cgd 
     35  1.24     joerg #if HAVE_NBTOOL_CONFIG_H
     36  1.24     joerg #include "nbtool_config.h"
     37  1.24     joerg #endif
     38  1.24     joerg 
     39   1.9  christos #include <sys/cdefs.h>
     40  1.25  christos __RCSID("$NetBSD: bt_open.c,v 1.25 2011/04/17 23:12:38 christos Exp $");
     41   1.1       cgd 
     42   1.1       cgd /*
     43   1.1       cgd  * Implementation of btree access method for 4.4BSD.
     44   1.1       cgd  *
     45   1.1       cgd  * The design here was originally based on that of the btree access method
     46   1.1       cgd  * used in the Postgres database system at UC Berkeley.  This implementation
     47   1.1       cgd  * is wholly independent of the Postgres code.
     48   1.1       cgd  */
     49   1.1       cgd 
     50  1.10       jtc #include "namespace.h"
     51   1.1       cgd #include <sys/stat.h>
     52   1.1       cgd 
     53  1.21  christos #include <assert.h>
     54   1.1       cgd #include <errno.h>
     55   1.1       cgd #include <fcntl.h>
     56   1.1       cgd #include <limits.h>
     57   1.1       cgd #include <signal.h>
     58   1.1       cgd #include <stdio.h>
     59   1.1       cgd #include <stdlib.h>
     60   1.1       cgd #include <string.h>
     61   1.1       cgd #include <unistd.h>
     62  1.11      fair #include <paths.h>
     63   1.1       cgd 
     64   1.1       cgd #include <db.h>
     65   1.1       cgd #include "btree.h"
     66   1.1       cgd 
     67   1.8       cgd #ifdef DEBUG
     68   1.8       cgd #undef	MINPSIZE
     69   1.8       cgd #define	MINPSIZE	128
     70   1.8       cgd #endif
     71   1.8       cgd 
     72  1.21  christos static int byteorder(void);
     73  1.21  christos static int nroot(BTREE *);
     74  1.21  christos static int tmp(void);
     75   1.1       cgd 
     76   1.1       cgd /*
     77   1.1       cgd  * __BT_OPEN -- Open a btree.
     78   1.1       cgd  *
     79   1.1       cgd  * Creates and fills a DB struct, and calls the routine that actually
     80   1.1       cgd  * opens the btree.
     81   1.1       cgd  *
     82   1.1       cgd  * Parameters:
     83   1.1       cgd  *	fname:	filename (NULL for in-memory trees)
     84   1.1       cgd  *	flags:	open flag bits
     85   1.1       cgd  *	mode:	open permission bits
     86   1.1       cgd  *	b:	BTREEINFO pointer
     87   1.1       cgd  *
     88   1.1       cgd  * Returns:
     89   1.1       cgd  *	NULL on failure, pointer to DB on success.
     90   1.1       cgd  *
     91   1.1       cgd  */
     92   1.1       cgd DB *
     93  1.21  christos __bt_open(const char *fname, int flags, mode_t mode, const BTREEINFO *openinfo,
     94  1.21  christos     int dflags)
     95   1.1       cgd {
     96   1.6       cgd 	struct stat sb;
     97   1.1       cgd 	BTMETA m;
     98   1.1       cgd 	BTREE *t;
     99   1.1       cgd 	BTREEINFO b;
    100   1.1       cgd 	DB *dbp;
    101   1.1       cgd 	pgno_t ncache;
    102   1.6       cgd 	ssize_t nr;
    103  1.21  christos 	size_t temp;
    104   1.6       cgd 	int machine_lorder;
    105   1.1       cgd 
    106   1.1       cgd 	t = NULL;
    107   1.1       cgd 
    108   1.1       cgd 	/*
    109   1.1       cgd 	 * Intention is to make sure all of the user's selections are okay
    110   1.1       cgd 	 * here and then use them without checking.  Can't be complete, since
    111   1.1       cgd 	 * we don't know the right page size, lorder or flags until the backing
    112   1.1       cgd 	 * file is opened.  Also, the file's page size can cause the cachesize
    113   1.1       cgd 	 * to change.
    114   1.1       cgd 	 */
    115   1.1       cgd 	machine_lorder = byteorder();
    116   1.1       cgd 	if (openinfo) {
    117   1.1       cgd 		b = *openinfo;
    118   1.1       cgd 
    119   1.1       cgd 		/* Flags: R_DUP. */
    120   1.1       cgd 		if (b.flags & ~(R_DUP))
    121   1.1       cgd 			goto einval;
    122   1.1       cgd 
    123   1.1       cgd 		/*
    124   1.1       cgd 		 * Page size must be indx_t aligned and >= MINPSIZE.  Default
    125   1.1       cgd 		 * page size is set farther on, based on the underlying file
    126   1.1       cgd 		 * transfer size.
    127   1.1       cgd 		 */
    128   1.1       cgd 		if (b.psize &&
    129   1.1       cgd 		    (b.psize < MINPSIZE || b.psize > MAX_PAGE_OFFSET + 1 ||
    130   1.9  christos 		    b.psize & (sizeof(indx_t) - 1)))
    131   1.1       cgd 			goto einval;
    132   1.1       cgd 
    133   1.1       cgd 		/* Minimum number of keys per page; absolute minimum is 2. */
    134   1.1       cgd 		if (b.minkeypage) {
    135   1.1       cgd 			if (b.minkeypage < 2)
    136   1.1       cgd 				goto einval;
    137   1.1       cgd 		} else
    138   1.1       cgd 			b.minkeypage = DEFMINKEYPAGE;
    139   1.1       cgd 
    140   1.1       cgd 		/* If no comparison, use default comparison and prefix. */
    141   1.1       cgd 		if (b.compare == NULL) {
    142   1.1       cgd 			b.compare = __bt_defcmp;
    143   1.1       cgd 			if (b.prefix == NULL)
    144   1.1       cgd 				b.prefix = __bt_defpfx;
    145   1.1       cgd 		}
    146   1.1       cgd 
    147   1.1       cgd 		if (b.lorder == 0)
    148   1.1       cgd 			b.lorder = machine_lorder;
    149   1.1       cgd 	} else {
    150   1.1       cgd 		b.compare = __bt_defcmp;
    151   1.1       cgd 		b.cachesize = 0;
    152   1.1       cgd 		b.flags = 0;
    153   1.1       cgd 		b.lorder = machine_lorder;
    154   1.1       cgd 		b.minkeypage = DEFMINKEYPAGE;
    155   1.1       cgd 		b.prefix = __bt_defpfx;
    156   1.1       cgd 		b.psize = 0;
    157   1.1       cgd 	}
    158   1.1       cgd 
    159   1.1       cgd 	/* Check for the ubiquitous PDP-11. */
    160   1.1       cgd 	if (b.lorder != BIG_ENDIAN && b.lorder != LITTLE_ENDIAN)
    161   1.1       cgd 		goto einval;
    162   1.1       cgd 
    163   1.1       cgd 	/* Allocate and initialize DB and BTREE structures. */
    164   1.6       cgd 	if ((t = (BTREE *)malloc(sizeof(BTREE))) == NULL)
    165   1.1       cgd 		goto err;
    166   1.5       cgd 	memset(t, 0, sizeof(BTREE));
    167   1.1       cgd 	t->bt_fd = -1;			/* Don't close unopened fd on error. */
    168   1.1       cgd 	t->bt_lorder = b.lorder;
    169   1.1       cgd 	t->bt_order = NOT;
    170   1.1       cgd 	t->bt_cmp = b.compare;
    171   1.1       cgd 	t->bt_pfx = b.prefix;
    172   1.5       cgd 	t->bt_rfd = -1;
    173   1.5       cgd 
    174   1.6       cgd 	if ((t->bt_dbp = dbp = (DB *)malloc(sizeof(DB))) == NULL)
    175   1.5       cgd 		goto err;
    176   1.8       cgd 	memset(t->bt_dbp, 0, sizeof(DB));
    177   1.1       cgd 	if (t->bt_lorder != machine_lorder)
    178   1.8       cgd 		F_SET(t, B_NEEDSWAP);
    179   1.1       cgd 
    180   1.1       cgd 	dbp->type = DB_BTREE;
    181   1.1       cgd 	dbp->internal = t;
    182   1.1       cgd 	dbp->close = __bt_close;
    183   1.1       cgd 	dbp->del = __bt_delete;
    184   1.1       cgd 	dbp->fd = __bt_fd;
    185   1.1       cgd 	dbp->get = __bt_get;
    186   1.1       cgd 	dbp->put = __bt_put;
    187   1.1       cgd 	dbp->seq = __bt_seq;
    188   1.1       cgd 	dbp->sync = __bt_sync;
    189   1.1       cgd 
    190   1.1       cgd 	/*
    191   1.1       cgd 	 * If no file name was supplied, this is an in-memory btree and we
    192   1.1       cgd 	 * open a backing temporary file.  Otherwise, it's a disk-based tree.
    193   1.1       cgd 	 */
    194   1.1       cgd 	if (fname) {
    195   1.8       cgd 		switch (flags & O_ACCMODE) {
    196   1.1       cgd 		case O_RDONLY:
    197   1.8       cgd 			F_SET(t, B_RDONLY);
    198   1.1       cgd 			break;
    199   1.1       cgd 		case O_RDWR:
    200   1.1       cgd 			break;
    201   1.1       cgd 		case O_WRONLY:
    202   1.1       cgd 		default:
    203   1.1       cgd 			goto einval;
    204   1.1       cgd 		}
    205   1.1       cgd 
    206  1.18   mycroft 		if ((t->bt_fd = open(fname, flags, mode)) == -1)
    207  1.18   mycroft 			goto err;
    208  1.18   mycroft 		if (fcntl(t->bt_fd, F_SETFD, FD_CLOEXEC) == -1)
    209   1.1       cgd 			goto err;
    210   1.1       cgd 	} else {
    211   1.1       cgd 		if ((flags & O_ACCMODE) != O_RDWR)
    212   1.1       cgd 			goto einval;
    213   1.1       cgd 		if ((t->bt_fd = tmp()) == -1)
    214   1.1       cgd 			goto err;
    215   1.8       cgd 		F_SET(t, B_INMEM);
    216   1.1       cgd 	}
    217   1.1       cgd 
    218  1.20  christos 	if (fcntl(t->bt_fd, F_SETFD, FD_CLOEXEC) == -1)
    219   1.1       cgd 		goto err;
    220   1.1       cgd 
    221   1.1       cgd 	if (fstat(t->bt_fd, &sb))
    222   1.1       cgd 		goto err;
    223   1.1       cgd 	if (sb.st_size) {
    224   1.6       cgd 		if ((nr = read(t->bt_fd, &m, sizeof(BTMETA))) < 0)
    225   1.1       cgd 			goto err;
    226   1.1       cgd 		if (nr != sizeof(BTMETA))
    227   1.1       cgd 			goto eftype;
    228   1.1       cgd 
    229   1.1       cgd 		/*
    230   1.1       cgd 		 * Read in the meta-data.  This can change the notion of what
    231   1.1       cgd 		 * the lorder, page size and flags are, and, when the page size
    232   1.1       cgd 		 * changes, the cachesize value can change too.  If the user
    233   1.1       cgd 		 * specified the wrong byte order for an existing database, we
    234   1.1       cgd 		 * don't bother to return an error, we just clear the NEEDSWAP
    235   1.1       cgd 		 * bit.
    236   1.1       cgd 		 */
    237   1.8       cgd 		if (m.magic == BTREEMAGIC)
    238   1.8       cgd 			F_CLR(t, B_NEEDSWAP);
    239   1.1       cgd 		else {
    240   1.8       cgd 			F_SET(t, B_NEEDSWAP);
    241   1.8       cgd 			M_32_SWAP(m.magic);
    242   1.8       cgd 			M_32_SWAP(m.version);
    243   1.8       cgd 			M_32_SWAP(m.psize);
    244   1.8       cgd 			M_32_SWAP(m.free);
    245   1.8       cgd 			M_32_SWAP(m.nrecs);
    246   1.8       cgd 			M_32_SWAP(m.flags);
    247   1.1       cgd 		}
    248   1.8       cgd 		if (m.magic != BTREEMAGIC || m.version != BTREEVERSION)
    249   1.1       cgd 			goto eftype;
    250   1.8       cgd 		if (m.psize < MINPSIZE || m.psize > MAX_PAGE_OFFSET + 1 ||
    251   1.9  christos 		    m.psize & (sizeof(indx_t) - 1))
    252   1.1       cgd 			goto eftype;
    253   1.8       cgd 		if (m.flags & ~SAVEMETA)
    254   1.1       cgd 			goto eftype;
    255   1.8       cgd 		b.psize = m.psize;
    256   1.8       cgd 		F_SET(t, m.flags);
    257   1.8       cgd 		t->bt_free = m.free;
    258   1.8       cgd 		t->bt_nrecs = m.nrecs;
    259   1.1       cgd 	} else {
    260   1.1       cgd 		/*
    261   1.1       cgd 		 * Set the page size to the best value for I/O to this file.
    262   1.1       cgd 		 * Don't overflow the page offset type.
    263   1.1       cgd 		 */
    264   1.1       cgd 		if (b.psize == 0) {
    265   1.1       cgd 			b.psize = sb.st_blksize;
    266   1.1       cgd 			if (b.psize < MINPSIZE)
    267   1.1       cgd 				b.psize = MINPSIZE;
    268   1.1       cgd 			if (b.psize > MAX_PAGE_OFFSET + 1)
    269   1.1       cgd 				b.psize = MAX_PAGE_OFFSET + 1;
    270   1.1       cgd 		}
    271   1.1       cgd 
    272   1.1       cgd 		/* Set flag if duplicates permitted. */
    273   1.1       cgd 		if (!(b.flags & R_DUP))
    274   1.8       cgd 			F_SET(t, B_NODUPS);
    275   1.1       cgd 
    276   1.1       cgd 		t->bt_free = P_INVALID;
    277   1.1       cgd 		t->bt_nrecs = 0;
    278   1.8       cgd 		F_SET(t, B_METADIRTY);
    279   1.1       cgd 	}
    280   1.1       cgd 
    281   1.1       cgd 	t->bt_psize = b.psize;
    282   1.1       cgd 
    283   1.1       cgd 	/* Set the cache size; must be a multiple of the page size. */
    284   1.9  christos 	if (b.cachesize && b.cachesize & (b.psize - 1))
    285   1.9  christos 		b.cachesize += (~b.cachesize & (b.psize - 1)) + 1;
    286   1.1       cgd 	if (b.cachesize < b.psize * MINCACHE)
    287   1.1       cgd 		b.cachesize = b.psize * MINCACHE;
    288   1.1       cgd 
    289   1.1       cgd 	/* Calculate number of pages to cache. */
    290   1.1       cgd 	ncache = (b.cachesize + t->bt_psize - 1) / t->bt_psize;
    291   1.1       cgd 
    292   1.1       cgd 	/*
    293   1.1       cgd 	 * The btree data structure requires that at least two keys can fit on
    294   1.1       cgd 	 * a page, but other than that there's no fixed requirement.  The user
    295   1.1       cgd 	 * specified a minimum number per page, and we translated that into the
    296   1.1       cgd 	 * number of bytes a key/data pair can use before being placed on an
    297   1.1       cgd 	 * overflow page.  This calculation includes the page header, the size
    298   1.1       cgd 	 * of the index referencing the leaf item and the size of the leaf item
    299   1.1       cgd 	 * structure.  Also, don't let the user specify a minkeypage such that
    300   1.1       cgd 	 * a key/data pair won't fit even if both key and data are on overflow
    301   1.1       cgd 	 * pages.
    302   1.1       cgd 	 */
    303  1.21  christos 	temp = (t->bt_psize - BTDATAOFF) / b.minkeypage -
    304   1.1       cgd 	    (sizeof(indx_t) + NBLEAFDBT(0, 0));
    305  1.21  christos 	_DBFIT(temp, indx_t);
    306  1.21  christos 	t->bt_ovflsize = (indx_t)temp;
    307   1.1       cgd 	if (t->bt_ovflsize < NBLEAFDBT(NOVFLSIZE, NOVFLSIZE) + sizeof(indx_t))
    308   1.1       cgd 		t->bt_ovflsize =
    309   1.1       cgd 		    NBLEAFDBT(NOVFLSIZE, NOVFLSIZE) + sizeof(indx_t);
    310   1.1       cgd 
    311   1.1       cgd 	/* Initialize the buffer pool. */
    312   1.1       cgd 	if ((t->bt_mp =
    313   1.1       cgd 	    mpool_open(NULL, t->bt_fd, t->bt_psize, ncache)) == NULL)
    314   1.1       cgd 		goto err;
    315   1.8       cgd 	if (!F_ISSET(t, B_INMEM))
    316   1.1       cgd 		mpool_filter(t->bt_mp, __bt_pgin, __bt_pgout, t);
    317   1.1       cgd 
    318   1.1       cgd 	/* Create a root page if new tree. */
    319   1.1       cgd 	if (nroot(t) == RET_ERROR)
    320   1.1       cgd 		goto err;
    321   1.1       cgd 
    322   1.4       cgd 	/* Global flags. */
    323   1.4       cgd 	if (dflags & DB_LOCK)
    324   1.8       cgd 		F_SET(t, B_DB_LOCK);
    325   1.4       cgd 	if (dflags & DB_SHMEM)
    326   1.8       cgd 		F_SET(t, B_DB_SHMEM);
    327   1.4       cgd 	if (dflags & DB_TXN)
    328   1.8       cgd 		F_SET(t, B_DB_TXN);
    329   1.4       cgd 
    330   1.1       cgd 	return (dbp);
    331   1.1       cgd 
    332   1.1       cgd einval:	errno = EINVAL;
    333   1.1       cgd 	goto err;
    334   1.1       cgd 
    335   1.1       cgd eftype:	errno = EFTYPE;
    336   1.1       cgd 	goto err;
    337   1.1       cgd 
    338   1.1       cgd err:	if (t) {
    339   1.1       cgd 		if (t->bt_dbp)
    340   1.1       cgd 			free(t->bt_dbp);
    341   1.1       cgd 		if (t->bt_fd != -1)
    342   1.1       cgd 			(void)close(t->bt_fd);
    343   1.1       cgd 		free(t);
    344   1.1       cgd 	}
    345   1.1       cgd 	return (NULL);
    346   1.1       cgd }
    347   1.1       cgd 
    348   1.1       cgd /*
    349   1.1       cgd  * NROOT -- Create the root of a new tree.
    350   1.1       cgd  *
    351   1.1       cgd  * Parameters:
    352   1.1       cgd  *	t:	tree
    353   1.1       cgd  *
    354   1.1       cgd  * Returns:
    355   1.1       cgd  *	RET_ERROR, RET_SUCCESS
    356   1.1       cgd  */
    357   1.1       cgd static int
    358  1.21  christos nroot(BTREE *t)
    359   1.1       cgd {
    360   1.1       cgd 	PAGE *meta, *root;
    361   1.1       cgd 	pgno_t npg;
    362   1.1       cgd 
    363   1.1       cgd 	if ((meta = mpool_get(t->bt_mp, 0, 0)) != NULL) {
    364   1.1       cgd 		mpool_put(t->bt_mp, meta, 0);
    365   1.1       cgd 		return (RET_SUCCESS);
    366   1.1       cgd 	}
    367   1.6       cgd 	if (errno != EINVAL)		/* It's OK to not exist. */
    368   1.1       cgd 		return (RET_ERROR);
    369   1.6       cgd 	errno = 0;
    370   1.1       cgd 
    371   1.1       cgd 	if ((meta = mpool_new(t->bt_mp, &npg)) == NULL)
    372   1.1       cgd 		return (RET_ERROR);
    373   1.1       cgd 
    374   1.1       cgd 	if ((root = mpool_new(t->bt_mp, &npg)) == NULL)
    375   1.1       cgd 		return (RET_ERROR);
    376   1.1       cgd 
    377   1.1       cgd 	if (npg != P_ROOT)
    378   1.1       cgd 		return (RET_ERROR);
    379   1.1       cgd 	root->pgno = npg;
    380   1.1       cgd 	root->prevpg = root->nextpg = P_INVALID;
    381   1.1       cgd 	root->lower = BTDATAOFF;
    382   1.1       cgd 	root->upper = t->bt_psize;
    383   1.1       cgd 	root->flags = P_BLEAF;
    384   1.1       cgd 	memset(meta, 0, t->bt_psize);
    385   1.1       cgd 	mpool_put(t->bt_mp, meta, MPOOL_DIRTY);
    386   1.1       cgd 	mpool_put(t->bt_mp, root, MPOOL_DIRTY);
    387   1.1       cgd 	return (RET_SUCCESS);
    388   1.1       cgd }
    389   1.1       cgd 
    390   1.1       cgd static int
    391  1.21  christos tmp(void)
    392   1.1       cgd {
    393   1.1       cgd 	sigset_t set, oset;
    394  1.25  christos 	int len;
    395  1.16   thorpej 	int fd;
    396   1.1       cgd 	char *envtmp;
    397  1.14   thorpej 	char path[PATH_MAX];
    398   1.1       cgd 
    399  1.15      groo 	if (issetugid())
    400  1.15      groo 		envtmp = NULL;
    401  1.15      groo 	else
    402  1.15      groo 		envtmp = getenv("TMPDIR");
    403  1.15      groo 
    404  1.15      groo 	len = snprintf(path,
    405  1.11      fair 	    sizeof(path), "%s/bt.XXXXXX", envtmp ? envtmp : _PATH_TMP);
    406  1.25  christos 	if (len < 0 || (size_t)len >= sizeof(path)) {
    407  1.25  christos 		errno = ENAMETOOLONG;
    408  1.15      groo 		return -1;
    409  1.25  christos 	}
    410  1.15      groo 
    411   1.1       cgd 	(void)sigfillset(&set);
    412   1.1       cgd 	(void)sigprocmask(SIG_BLOCK, &set, &oset);
    413  1.19       rtr 	if ((fd = mkstemp(path)) != -1) {
    414   1.1       cgd 		(void)unlink(path);
    415  1.20  christos 		(void)fcntl(fd, F_SETFD, FD_CLOEXEC);
    416  1.19       rtr 	}
    417   1.1       cgd 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
    418   1.1       cgd 	return(fd);
    419   1.1       cgd }
    420   1.1       cgd 
    421   1.1       cgd static int
    422  1.21  christos byteorder(void)
    423   1.1       cgd {
    424  1.22     joerg 	uint32_t x;
    425  1.22     joerg 	uint8_t *p;
    426   1.1       cgd 
    427   1.1       cgd 	x = 0x01020304;
    428  1.22     joerg 	p = (uint8_t *)(void *)&x;
    429   1.1       cgd 	switch (*p) {
    430   1.1       cgd 	case 1:
    431   1.1       cgd 		return (BIG_ENDIAN);
    432   1.1       cgd 	case 4:
    433   1.1       cgd 		return (LITTLE_ENDIAN);
    434   1.1       cgd 	default:
    435   1.1       cgd 		return (0);
    436   1.1       cgd 	}
    437   1.1       cgd }
    438   1.1       cgd 
    439   1.1       cgd int
    440  1.21  christos __bt_fd(const DB *dbp)
    441   1.1       cgd {
    442   1.1       cgd 	BTREE *t;
    443   1.1       cgd 
    444   1.1       cgd 	t = dbp->internal;
    445   1.1       cgd 
    446   1.4       cgd 	/* Toss any page pinned across calls. */
    447   1.4       cgd 	if (t->bt_pinned != NULL) {
    448   1.4       cgd 		mpool_put(t->bt_mp, t->bt_pinned, 0);
    449   1.4       cgd 		t->bt_pinned = NULL;
    450   1.4       cgd 	}
    451   1.4       cgd 
    452   1.4       cgd 	/* In-memory database can't have a file descriptor. */
    453   1.8       cgd 	if (F_ISSET(t, B_INMEM)) {
    454   1.1       cgd 		errno = ENOENT;
    455   1.1       cgd 		return (-1);
    456   1.1       cgd 	}
    457   1.1       cgd 	return (t->bt_fd);
    458   1.1       cgd }
    459