* hurd/hurd/signal.h (struct hurd_sigstate): New member `preempters'. cvs/libc-960102

	(hurd_preempt_signals, hurd_unpreempt_signals): Decls removed.
	* hurd/hurd/sigpreempt.h: New file.
	* hurd/preempt-sig.c: Rewritten with new interface.
	* sysdeps/mach/hurd/jmp-unwind.c (_longjmp_unwind): Remove local signal
	preempters being unwound past.

	* db: New directory, 4.4 BSD db package incorporated from BSD db-1.85
	release.

	* sysdeps/unix/sysv/linux/sys/param.h: Several new macros for BSD
	compatibility.

1 files changed, 944 insertions, 0 deletions

diff --git a/db/hash/hash_page.c b/db/hash/hash_page.c
new file mode 100644
index 0000000000..e1dfe6b8d6
--- /dev/null
+++ b/db/hash/hash_page.c
@@ -0,0 +1,944 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Margo Seltzer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)hash_page.c	8.7 (Berkeley) 8/16/94";
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * PACKAGE:  hashing
+ *
+ * DESCRIPTION:
+ *	Page manipulation for hashing package.
+ *
+ * ROUTINES:
+ *
+ * External
+ *	__get_page
+ *	__add_ovflpage
+ * Internal
+ *	overflow_page
+ *	open_temp
+ */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#ifdef DEBUG
+#include <assert.h>
+#endif
+
+#include <db.h>
+#include "hash.h"
+#include "page.h"
+#include "extern.h"
+
+static u_int32_t	*fetch_bitmap __P((HTAB *, int));
+static u_int32_t	 first_free __P((u_int32_t));
+static int	 open_temp __P((HTAB *));
+static u_int16_t	 overflow_page __P((HTAB *));
+static void	 putpair __P((char *, const DBT *, const DBT *));
+static void	 squeeze_key __P((u_int16_t *, const DBT *, const DBT *));
+static int	 ugly_split
+		    __P((HTAB *, u_int32_t, BUFHEAD *, BUFHEAD *, int, int));
+
+#define	PAGE_INIT(P) { \
+	((u_int16_t *)(P))[0] = 0; \
+	((u_int16_t *)(P))[1] = hashp->BSIZE - 3 * sizeof(u_int16_t); \
+	((u_int16_t *)(P))[2] = hashp->BSIZE; \
+}
+
+/*
+ * This is called AFTER we have verified that there is room on the page for
+ * the pair (PAIRFITS has returned true) so we go right ahead and start moving
+ * stuff on.
+ */
+static void
+putpair(p, key, val)
+	char *p;
+	const DBT *key, *val;
+{
+	register u_int16_t *bp, n, off;
+
+	bp = (u_int16_t *)p;
+
+	/* Enter the key first. */
+	n = bp[0];
+
+	off = OFFSET(bp) - key->size;
+	memmove(p + off, key->data, key->size);
+	bp[++n] = off;
+
+	/* Now the data. */
+	off -= val->size;
+	memmove(p + off, val->data, val->size);
+	bp[++n] = off;
+
+	/* Adjust page info. */
+	bp[0] = n;
+	bp[n + 1] = off - ((n + 3) * sizeof(u_int16_t));
+	bp[n + 2] = off;
+}
+
+/*
+ * Returns:
+ *	 0 OK
+ *	-1 error
+ */
+extern int
+__delpair(hashp, bufp, ndx)
+	HTAB *hashp;
+	BUFHEAD *bufp;
+	register int ndx;
+{
+	register u_int16_t *bp, newoff;
+	register int n;
+	u_int16_t pairlen;
+
+	bp = (u_int16_t *)bufp->page;
+	n = bp[0];
+
+	if (bp[ndx + 1] < REAL_KEY)
+		return (__big_delete(hashp, bufp));
+	if (ndx != 1)
+		newoff = bp[ndx - 1];
+	else
+		newoff = hashp->BSIZE;
+	pairlen = newoff - bp[ndx + 1];
+
+	if (ndx != (n - 1)) {
+		/* Hard Case -- need to shuffle keys */
+		register int i;
+		register char *src = bufp->page + (int)OFFSET(bp);
+		register char *dst = src + (int)pairlen;
+		memmove(dst, src, bp[ndx + 1] - OFFSET(bp));
+
+		/* Now adjust the pointers */
+		for (i = ndx + 2; i <= n; i += 2) {
+			if (bp[i + 1] == OVFLPAGE) {
+				bp[i - 2] = bp[i];
+				bp[i - 1] = bp[i + 1];
+			} else {
+				bp[i - 2] = bp[i] + pairlen;
+				bp[i - 1] = bp[i + 1] + pairlen;
+			}
+		}
+	}
+	/* Finally adjust the page data */
+	bp[n] = OFFSET(bp) + pairlen;
+	bp[n - 1] = bp[n + 1] + pairlen + 2 * sizeof(u_int16_t);
+	bp[0] = n - 2;
+	hashp->NKEYS--;
+
+	bufp->flags |= BUF_MOD;
+	return (0);
+}
+/*
+ * Returns:
+ *	 0 ==> OK
+ *	-1 ==> Error
+ */
+extern int
+__split_page(hashp, obucket, nbucket)
+	HTAB *hashp;
+	u_int32_t obucket, nbucket;
+{
+	register BUFHEAD *new_bufp, *old_bufp;
+	register u_int16_t *ino;
+	register char *np;
+	DBT key, val;
+	int n, ndx, retval;
+	u_int16_t copyto, diff, off, moved;
+	char *op;
+
+	copyto = (u_int16_t)hashp->BSIZE;
+	off = (u_int16_t)hashp->BSIZE;
+	old_bufp = __get_buf(hashp, obucket, NULL, 0);
+	if (old_bufp == NULL)
+		return (-1);
+	new_bufp = __get_buf(hashp, nbucket, NULL, 0);
+	if (new_bufp == NULL)
+		return (-1);
+
+	old_bufp->flags |= (BUF_MOD | BUF_PIN);
+	new_bufp->flags |= (BUF_MOD | BUF_PIN);
+
+	ino = (u_int16_t *)(op = old_bufp->page);
+	np = new_bufp->page;
+
+	moved = 0;
+
+	for (n = 1, ndx = 1; n < ino[0]; n += 2) {
+		if (ino[n + 1] < REAL_KEY) {
+			retval = ugly_split(hashp, obucket, old_bufp, new_bufp,
+			    (int)copyto, (int)moved);
+			old_bufp->flags &= ~BUF_PIN;
+			new_bufp->flags &= ~BUF_PIN;
+			return (retval);
+
+		}
+		key.data = (u_char *)op + ino[n];
+		key.size = off - ino[n];
+
+		if (__call_hash(hashp, key.data, key.size) == obucket) {
+			/* Don't switch page */
+			diff = copyto - off;
+			if (diff) {
+				copyto = ino[n + 1] + diff;
+				memmove(op + copyto, op + ino[n + 1],
+				    off - ino[n + 1]);
+				ino[ndx] = copyto + ino[n] - ino[n + 1];
+				ino[ndx + 1] = copyto;
+			} else
+				copyto = ino[n + 1];
+			ndx += 2;
+		} else {
+			/* Switch page */
+			val.data = (u_char *)op + ino[n + 1];
+			val.size = ino[n] - ino[n + 1];
+			putpair(np, &key, &val);
+			moved += 2;
+		}
+
+		off = ino[n + 1];
+	}
+
+	/* Now clean up the page */
+	ino[0] -= moved;
+	FREESPACE(ino) = copyto - sizeof(u_int16_t) * (ino[0] + 3);
+	OFFSET(ino) = copyto;
+
+#ifdef DEBUG3
+	(void)fprintf(stderr, "split %d/%d\n",
+	    ((u_int16_t *)np)[0] / 2,
+	    ((u_int16_t *)op)[0] / 2);
+#endif
+	/* unpin both pages */
+	old_bufp->flags &= ~BUF_PIN;
+	new_bufp->flags &= ~BUF_PIN;
+	return (0);
+}
+
+/*
+ * Called when we encounter an overflow or big key/data page during split
+ * handling.  This is special cased since we have to begin checking whether
+ * the key/data pairs fit on their respective pages and because we may need
+ * overflow pages for both the old and new pages.
+ *
+ * The first page might be a page with regular key/data pairs in which case
+ * we have a regular overflow condition and just need to go on to the next
+ * page or it might be a big key/data pair in which case we need to fix the
+ * big key/data pair.
+ *
+ * Returns:
+ *	 0 ==> success
+ *	-1 ==> failure
+ */
+static int
+ugly_split(hashp, obucket, old_bufp, new_bufp, copyto, moved)
+	HTAB *hashp;
+	u_int32_t obucket;	/* Same as __split_page. */
+	BUFHEAD *old_bufp, *new_bufp;
+	int copyto;	/* First byte on page which contains key/data values. */
+	int moved;	/* Number of pairs moved to new page. */
+{
+	register BUFHEAD *bufp;	/* Buffer header for ino */
+	register u_int16_t *ino;	/* Page keys come off of */
+	register u_int16_t *np;	/* New page */
+	register u_int16_t *op;	/* Page keys go on to if they aren't moving */
+
+	BUFHEAD *last_bfp;	/* Last buf header OVFL needing to be freed */
+	DBT key, val;
+	SPLIT_RETURN ret;
+	u_int16_t n, off, ov_addr, scopyto;
+	char *cino;		/* Character value of ino */
+
+	bufp = old_bufp;
+	ino = (u_int16_t *)old_bufp->page;
+	np = (u_int16_t *)new_bufp->page;
+	op = (u_int16_t *)old_bufp->page;
+	last_bfp = NULL;
+	scopyto = (u_int16_t)copyto;	/* ANSI */
+
+	n = ino[0] - 1;
+	while (n < ino[0]) {
+		if (ino[2] < REAL_KEY && ino[2] != OVFLPAGE) {
+			if (__big_split(hashp, old_bufp,
+			    new_bufp, bufp, bufp->addr, obucket, &ret))
+				return (-1);
+			old_bufp = ret.oldp;
+			if (!old_bufp)
+				return (-1);
+			op = (u_int16_t *)old_bufp->page;
+			new_bufp = ret.newp;
+			if (!new_bufp)
+				return (-1);
+			np = (u_int16_t *)new_bufp->page;
+			bufp = ret.nextp;
+			if (!bufp)
+				return (0);
+			cino = (char *)bufp->page;
+			ino = (u_int16_t *)cino;
+			last_bfp = ret.nextp;
+		} else if (ino[n + 1] == OVFLPAGE) {
+			ov_addr = ino[n];
+			/*
+			 * Fix up the old page -- the extra 2 are the fields
+			 * which contained the overflow information.
+			 */
+			ino[0] -= (moved + 2);
+			FREESPACE(ino) =
+			    scopyto - sizeof(u_int16_t) * (ino[0] + 3);
+			OFFSET(ino) = scopyto;
+
+			bufp = __get_buf(hashp, ov_addr, bufp, 0);
+			if (!bufp)
+				return (-1);
+
+			ino = (u_int16_t *)bufp->page;
+			n = 1;
+			scopyto = hashp->BSIZE;
+			moved = 0;
+
+			if (last_bfp)
+				__free_ovflpage(hashp, last_bfp);
+			last_bfp = bufp;
+		}
+		/* Move regular sized pairs of there are any */
+		off = hashp->BSIZE;
+		for (n = 1; (n < ino[0]) && (ino[n + 1] >= REAL_KEY); n += 2) {
+			cino = (char *)ino;
+			key.data = (u_char *)cino + ino[n];
+			key.size = off - ino[n];
+			val.data = (u_char *)cino + ino[n + 1];
+			val.size = ino[n] - ino[n + 1];
+			off = ino[n + 1];
+
+			if (__call_hash(hashp, key.data, key.size) == obucket) {
+				/* Keep on old page */
+				if (PAIRFITS(op, (&key), (&val)))
+					putpair((char *)op, &key, &val);
+				else {
+					old_bufp =
+					    __add_ovflpage(hashp, old_bufp);
+					if (!old_bufp)
+						return (-1);
+					op = (u_int16_t *)old_bufp->page;
+					putpair((char *)op, &key, &val);
+				}
+				old_bufp->flags |= BUF_MOD;
+			} else {
+				/* Move to new page */
+				if (PAIRFITS(np, (&key), (&val)))
+					putpair((char *)np, &key, &val);
+				else {
+					new_bufp =
+					    __add_ovflpage(hashp, new_bufp);
+					if (!new_bufp)
+						return (-1);
+					np = (u_int16_t *)new_bufp->page;
+					putpair((char *)np, &key, &val);
+				}
+				new_bufp->flags |= BUF_MOD;
+			}
+		}
+	}
+	if (last_bfp)
+		__free_ovflpage(hashp, last_bfp);
+	return (0);
+}
+
+/*
+ * Add the given pair to the page
+ *
+ * Returns:
+ *	0 ==> OK
+ *	1 ==> failure
+ */
+extern int
+__addel(hashp, bufp, key, val)
+	HTAB *hashp;
+	BUFHEAD *bufp;
+	const DBT *key, *val;
+{
+	register u_int16_t *bp, *sop;
+	int do_expand;
+
+	bp = (u_int16_t *)bufp->page;
+	do_expand = 0;
+	while (bp[0] && (bp[2] < REAL_KEY || bp[bp[0]] < REAL_KEY))
+		/* Exception case */
+		if (bp[2] == FULL_KEY_DATA && bp[0] == 2)
+			/* This is the last page of a big key/data pair
+			   and we need to add another page */
+			break;
+		else if (bp[2] < REAL_KEY && bp[bp[0]] != OVFLPAGE) {
+			bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+			if (!bufp)
+				return (-1);
+			bp = (u_int16_t *)bufp->page;
+		} else
+			/* Try to squeeze key on this page */
+			if (FREESPACE(bp) > PAIRSIZE(key, val)) {
+				squeeze_key(bp, key, val);
+				return (0);
+			} else {
+				bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+				if (!bufp)
+					return (-1);
+				bp = (u_int16_t *)bufp->page;
+			}
+
+	if (PAIRFITS(bp, key, val))
+		putpair(bufp->page, key, val);
+	else {
+		do_expand = 1;
+		bufp = __add_ovflpage(hashp, bufp);
+		if (!bufp)
+			return (-1);
+		sop = (u_int16_t *)bufp->page;
+
+		if (PAIRFITS(sop, key, val))
+			putpair((char *)sop, key, val);
+		else
+			if (__big_insert(hashp, bufp, key, val))
+				return (-1);
+	}
+	bufp->flags |= BUF_MOD;
+	/*
+	 * If the average number of keys per bucket exceeds the fill factor,
+	 * expand the table.
+	 */
+	hashp->NKEYS++;
+	if (do_expand ||
+	    (hashp->NKEYS / (hashp->MAX_BUCKET + 1) > hashp->FFACTOR))
+		return (__expand_table(hashp));
+	return (0);
+}
+
+/*
+ *
+ * Returns:
+ *	pointer on success
+ *	NULL on error
+ */
+extern BUFHEAD *
+__add_ovflpage(hashp, bufp)
+	HTAB *hashp;
+	BUFHEAD *bufp;
+{
+	register u_int16_t *sp;
+	u_int16_t ndx, ovfl_num;
+#ifdef DEBUG1
+	int tmp1, tmp2;
+#endif
+	sp = (u_int16_t *)bufp->page;
+
+	/* Check if we are dynamically determining the fill factor */
+	if (hashp->FFACTOR == DEF_FFACTOR) {
+		hashp->FFACTOR = sp[0] >> 1;
+		if (hashp->FFACTOR < MIN_FFACTOR)
+			hashp->FFACTOR = MIN_FFACTOR;
+	}
+	bufp->flags |= BUF_MOD;
+	ovfl_num = overflow_page(hashp);
+#ifdef DEBUG1
+	tmp1 = bufp->addr;
+	tmp2 = bufp->ovfl ? bufp->ovfl->addr : 0;
+#endif
+	if (!ovfl_num || !(bufp->ovfl = __get_buf(hashp, ovfl_num, bufp, 1)))
+		return (NULL);
+	bufp->ovfl->flags |= BUF_MOD;
+#ifdef DEBUG1
+	(void)fprintf(stderr, "ADDOVFLPAGE: %d->ovfl was %d is now %d\n",
+	    tmp1, tmp2, bufp->ovfl->addr);
+#endif
+	ndx = sp[0];
+	/*
+	 * Since a pair is allocated on a page only if there's room to add
+	 * an overflow page, we know that the OVFL information will fit on
+	 * the page.
+	 */
+	sp[ndx + 4] = OFFSET(sp);
+	sp[ndx + 3] = FREESPACE(sp) - OVFLSIZE;
+	sp[ndx + 1] = ovfl_num;
+	sp[ndx + 2] = OVFLPAGE;
+	sp[0] = ndx + 2;
+#ifdef HASH_STATISTICS
+	hash_overflows++;
+#endif
+	return (bufp->ovfl);
+}
+
+/*
+ * Returns:
+ *	 0 indicates SUCCESS
+ *	-1 indicates FAILURE
+ */
+extern int
+__get_page(hashp, p, bucket, is_bucket, is_disk, is_bitmap)
+	HTAB *hashp;
+	char *p;
+	u_int32_t bucket;
+	int is_bucket, is_disk, is_bitmap;
+{
+	register int fd, page, size;
+	int rsize;
+	u_int16_t *bp;
+
+	fd = hashp->fp;
+	size = hashp->BSIZE;
+
+	if ((fd == -1) || !is_disk) {
+		PAGE_INIT(p);
+		return (0);
+	}
+	if (is_bucket)
+		page = BUCKET_TO_PAGE(bucket);
+	else
+		page = OADDR_TO_PAGE(bucket);
+	if ((lseek(fd, (off_t)page << hashp->BSHIFT, SEEK_SET) == -1) ||
+	    ((rsize = read(fd, p, size)) == -1))
+		return (-1);
+	bp = (u_int16_t *)p;
+	if (!rsize)
+		bp[0] = 0;	/* We hit the EOF, so initialize a new page */
+	else
+		if (rsize != size) {
+			errno = EFTYPE;
+			return (-1);
+		}
+	if (!is_bitmap && !bp[0]) {
+		PAGE_INIT(p);
+	} else
+		if (hashp->LORDER != BYTE_ORDER) {
+			register int i, max;
+
+			if (is_bitmap) {
+				max = hashp->BSIZE >> 2; /* divide by 4 */
+				for (i = 0; i < max; i++)
+					M_32_SWAP(((int *)p)[i]);
+			} else {
+				M_16_SWAP(bp[0]);
+				max = bp[0] + 2;
+				for (i = 1; i <= max; i++)
+					M_16_SWAP(bp[i]);
+			}
+		}
+	return (0);
+}
+
+/*
+ * Write page p to disk
+ *
+ * Returns:
+ *	 0 ==> OK
+ *	-1 ==>failure
+ */
+extern int
+__put_page(hashp, p, bucket, is_bucket, is_bitmap)
+	HTAB *hashp;
+	char *p;
+	u_int32_t bucket;
+	int is_bucket, is_bitmap;
+{
+	register int fd, page, size;
+	int wsize;
+
+	size = hashp->BSIZE;
+	if ((hashp->fp == -1) && open_temp(hashp))
+		return (-1);
+	fd = hashp->fp;
+
+	if (hashp->LORDER != BYTE_ORDER) {
+		register int i;
+		register int max;
+
+		if (is_bitmap) {
+			max = hashp->BSIZE >> 2;	/* divide by 4 */
+			for (i = 0; i < max; i++)
+				M_32_SWAP(((int *)p)[i]);
+		} else {
+			max = ((u_int16_t *)p)[0] + 2;
+			for (i = 0; i <= max; i++)
+				M_16_SWAP(((u_int16_t *)p)[i]);
+		}
+	}
+	if (is_bucket)
+		page = BUCKET_TO_PAGE(bucket);
+	else
+		page = OADDR_TO_PAGE(bucket);
+	if ((lseek(fd, (off_t)page << hashp->BSHIFT, SEEK_SET) == -1) ||
+	    ((wsize = write(fd, p, size)) == -1))
+		/* Errno is set */
+		return (-1);
+	if (wsize != size) {
+		errno = EFTYPE;
+		return (-1);
+	}
+	return (0);
+}
+
+#define BYTE_MASK	((1 << INT_BYTE_SHIFT) -1)
+/*
+ * Initialize a new bitmap page.  Bitmap pages are left in memory
+ * once they are read in.
+ */
+extern int
+__ibitmap(hashp, pnum, nbits, ndx)
+	HTAB *hashp;
+	int pnum, nbits, ndx;
+{
+	u_int32_t *ip;
+	int clearbytes, clearints;
+
+	if ((ip = (u_int32_t *)malloc(hashp->BSIZE)) == NULL)
+		return (1);
+	hashp->nmaps++;
+	clearints = ((nbits - 1) >> INT_BYTE_SHIFT) + 1;
+	clearbytes = clearints << INT_TO_BYTE;
+	(void)memset((char *)ip, 0, clearbytes);
+	(void)memset(((char *)ip) + clearbytes, 0xFF,
+	    hashp->BSIZE - clearbytes);
+	ip[clearints - 1] = ALL_SET << (nbits & BYTE_MASK);
+	SETBIT(ip, 0);
+	hashp->BITMAPS[ndx] = (u_int16_t)pnum;
+	hashp->mapp[ndx] = ip;
+	return (0);
+}
+
+static u_int32_t
+first_free(map)
+	u_int32_t map;
+{
+	register u_int32_t i, mask;
+
+	mask = 0x1;
+	for (i = 0; i < BITS_PER_MAP; i++) {
+		if (!(mask & map))
+			return (i);
+		mask = mask << 1;
+	}
+	return (i);
+}
+
+static u_int16_t
+overflow_page(hashp)
+	HTAB *hashp;
+{
+	register u_int32_t *freep;
+	register int max_free, offset, splitnum;
+	u_int16_t addr;
+	int bit, first_page, free_bit, free_page, i, in_use_bits, j;
+#ifdef DEBUG2
+	int tmp1, tmp2;
+#endif
+	splitnum = hashp->OVFL_POINT;
+	max_free = hashp->SPARES[splitnum];
+
+	free_page = (max_free - 1) >> (hashp->BSHIFT + BYTE_SHIFT);
+	free_bit = (max_free - 1) & ((hashp->BSIZE << BYTE_SHIFT) - 1);
+
+	/* Look through all the free maps to find the first free block */
+	first_page = hashp->LAST_FREED >>(hashp->BSHIFT + BYTE_SHIFT);
+	for ( i = first_page; i <= free_page; i++ ) {
+		if (!(freep = (u_int32_t *)hashp->mapp[i]) &&
+		    !(freep = fetch_bitmap(hashp, i)))
+			return (0);
+		if (i == free_page)
+			in_use_bits = free_bit;
+		else
+			in_use_bits = (hashp->BSIZE << BYTE_SHIFT) - 1;
+		
+		if (i == first_page) {
+			bit = hashp->LAST_FREED &
+			    ((hashp->BSIZE << BYTE_SHIFT) - 1);
+			j = bit / BITS_PER_MAP;
+			bit = bit & ~(BITS_PER_MAP - 1);
+		} else {
+			bit = 0;
+			j = 0;
+		}
+		for (; bit <= in_use_bits; j++, bit += BITS_PER_MAP)
+			if (freep[j] != ALL_SET)
+				goto found;
+	}
+
+	/* No Free Page Found */
+	hashp->LAST_FREED = hashp->SPARES[splitnum];
+	hashp->SPARES[splitnum]++;
+	offset = hashp->SPARES[splitnum] -
+	    (splitnum ? hashp->SPARES[splitnum - 1] : 0);
+
+#define	OVMSG	"HASH: Out of overflow pages.  Increase page size\n"
+	if (offset > SPLITMASK) {
+		if (++splitnum >= NCACHED) {
+			(void)write(STDERR_FILENO, OVMSG, sizeof(OVMSG) - 1);
+			return (0);
+		}
+		hashp->OVFL_POINT = splitnum;
+		hashp->SPARES[splitnum] = hashp->SPARES[splitnum-1];
+		hashp->SPARES[splitnum-1]--;
+		offset = 1;
+	}
+
+	/* Check if we need to allocate a new bitmap page */
+	if (free_bit == (hashp->BSIZE << BYTE_SHIFT) - 1) {
+		free_page++;
+		if (free_page >= NCACHED) {
+			(void)write(STDERR_FILENO, OVMSG, sizeof(OVMSG) - 1);
+			return (0);
+		}
+		/*
+		 * This is tricky.  The 1 indicates that you want the new page
+		 * allocated with 1 clear bit.  Actually, you are going to
+		 * allocate 2 pages from this map.  The first is going to be
+		 * the map page, the second is the overflow page we were
+		 * looking for.  The init_bitmap routine automatically, sets
+		 * the first bit of itself to indicate that the bitmap itself
+		 * is in use.  We would explicitly set the second bit, but
+		 * don't have to if we tell init_bitmap not to leave it clear
+		 * in the first place.
+		 */
+		if (__ibitmap(hashp,
+		    (int)OADDR_OF(splitnum, offset), 1, free_page))
+			return (0);
+		hashp->SPARES[splitnum]++;
+#ifdef DEBUG2
+		free_bit = 2;
+#endif
+		offset++;
+		if (offset > SPLITMASK) {
+			if (++splitnum >= NCACHED) {
+				(void)write(STDERR_FILENO, OVMSG,
+				    sizeof(OVMSG) - 1);
+				return (0);
+			}
+			hashp->OVFL_POINT = splitnum;
+			hashp->SPARES[splitnum] = hashp->SPARES[splitnum-1];
+			hashp->SPARES[splitnum-1]--;
+			offset = 0;
+		}
+	} else {
+		/*
+		 * Free_bit addresses the last used bit.  Bump it to address
+		 * the first available bit.
+		 */
+		free_bit++;
+		SETBIT(freep, free_bit);
+	}
+
+	/* Calculate address of the new overflow page */
+	addr = OADDR_OF(splitnum, offset);
+#ifdef DEBUG2
+	(void)fprintf(stderr, "OVERFLOW_PAGE: ADDR: %d BIT: %d PAGE %d\n",
+	    addr, free_bit, free_page);
+#endif
+	return (addr);
+
+found:
+	bit = bit + first_free(freep[j]);
+	SETBIT(freep, bit);
+#ifdef DEBUG2
+	tmp1 = bit;
+	tmp2 = i;
+#endif
+	/*
+	 * Bits are addressed starting with 0, but overflow pages are addressed
+	 * beginning at 1. Bit is a bit addressnumber, so we need to increment
+	 * it to convert it to a page number.
+	 */
+	bit = 1 + bit + (i * (hashp->BSIZE << BYTE_SHIFT));
+	if (bit >= hashp->LAST_FREED)
+		hashp->LAST_FREED = bit - 1;
+
+	/* Calculate the split number for this page */
+	for (i = 0; (i < splitnum) && (bit > hashp->SPARES[i]); i++);
+	offset = (i ? bit - hashp->SPARES[i - 1] : bit);
+	if (offset >= SPLITMASK)
+		return (0);	/* Out of overflow pages */
+	addr = OADDR_OF(i, offset);
+#ifdef DEBUG2
+	(void)fprintf(stderr, "OVERFLOW_PAGE: ADDR: %d BIT: %d PAGE %d\n",
+	    addr, tmp1, tmp2);
+#endif
+
+	/* Allocate and return the overflow page */
+	return (addr);
+}
+
+/*
+ * Mark this overflow page as free.
+ */
+extern void
+__free_ovflpage(hashp, obufp)
+	HTAB *hashp;
+	BUFHEAD *obufp;
+{
+	register u_int16_t addr;
+	u_int32_t *freep;
+	int bit_address, free_page, free_bit;
+	u_int16_t ndx;
+
+	addr = obufp->addr;
+#ifdef DEBUG1
+	(void)fprintf(stderr, "Freeing %d\n", addr);
+#endif
+	ndx = (((u_int16_t)addr) >> SPLITSHIFT);
+	bit_address =
+	    (ndx ? hashp->SPARES[ndx - 1] : 0) + (addr & SPLITMASK) - 1;
+	 if (bit_address < hashp->LAST_FREED)
+		hashp->LAST_FREED = bit_address;
+	free_page = (bit_address >> (hashp->BSHIFT + BYTE_SHIFT));
+	free_bit = bit_address & ((hashp->BSIZE << BYTE_SHIFT) - 1);
+
+	if (!(freep = hashp->mapp[free_page]))
+		freep = fetch_bitmap(hashp, free_page);
+#ifdef DEBUG
+	/*
+	 * This had better never happen.  It means we tried to read a bitmap
+	 * that has already had overflow pages allocated off it, and we
+	 * failed to read it from the file.
+	 */
+	if (!freep)
+		assert(0);
+#endif
+	CLRBIT(freep, free_bit);
+#ifdef DEBUG2
+	(void)fprintf(stderr, "FREE_OVFLPAGE: ADDR: %d BIT: %d PAGE %d\n",
+	    obufp->addr, free_bit, free_page);
+#endif
+	__reclaim_buf(hashp, obufp);
+}
+
+/*
+ * Returns:
+ *	 0 success
+ *	-1 failure
+ */
+static int
+open_temp(hashp)
+	HTAB *hashp;
+{
+	sigset_t set, oset;
+	static char namestr[] = "_hashXXXXXX";
+
+	/* Block signals; make sure file goes away at process exit. */
+	(void)sigfillset(&set);
+	(void)sigprocmask(SIG_BLOCK, &set, &oset);
+	if ((hashp->fp = mkstemp(namestr)) != -1) {
+		(void)unlink(namestr);
+		(void)fcntl(hashp->fp, F_SETFD, 1);
+	}
+	(void)sigprocmask(SIG_SETMASK, &oset, (sigset_t *)NULL);
+	return (hashp->fp != -1 ? 0 : -1);
+}
+
+/*
+ * We have to know that the key will fit, but the last entry on the page is
+ * an overflow pair, so we need to shift things.
+ */
+static void
+squeeze_key(sp, key, val)
+	u_int16_t *sp;
+	const DBT *key, *val;
+{
+	register char *p;
+	u_int16_t free_space, n, off, pageno;
+
+	p = (char *)sp;
+	n = sp[0];
+	free_space = FREESPACE(sp);
+	off = OFFSET(sp);
+
+	pageno = sp[n - 1];
+	off -= key->size;
+	sp[n - 1] = off;
+	memmove(p + off, key->data, key->size);
+	off -= val->size;
+	sp[n] = off;
+	memmove(p + off, val->data, val->size);
+	sp[0] = n + 2;
+	sp[n + 1] = pageno;
+	sp[n + 2] = OVFLPAGE;
+	FREESPACE(sp) = free_space - PAIRSIZE(key, val);
+	OFFSET(sp) = off;
+}
+
+static u_int32_t *
+fetch_bitmap(hashp, ndx)
+	HTAB *hashp;
+	int ndx;
+{
+	if (ndx >= hashp->nmaps)
+		return (NULL);
+	if ((hashp->mapp[ndx] = (u_int32_t *)malloc(hashp->BSIZE)) == NULL)
+		return (NULL);
+	if (__get_page(hashp,
+	    (char *)hashp->mapp[ndx], hashp->BITMAPS[ndx], 0, 1, 1)) {
+		free(hashp->mapp[ndx]);
+		return (NULL);
+	}
+	return (hashp->mapp[ndx]);
+}
+
+#ifdef DEBUG4
+int
+print_chain(addr)
+	int addr;
+{
+	BUFHEAD *bufp;
+	short *bp, oaddr;
+
+	(void)fprintf(stderr, "%d ", addr);
+	bufp = __get_buf(hashp, addr, NULL, 0);
+	bp = (short *)bufp->page;
+	while (bp[0] && ((bp[bp[0]] == OVFLPAGE) ||
+		((bp[0] > 2) && bp[2] < REAL_KEY))) {
+		oaddr = bp[bp[0] - 1];
+		(void)fprintf(stderr, "%d ", (int)oaddr);
+		bufp = __get_buf(hashp, (int)oaddr, bufp, 0);
+		bp = (short *)bufp->page;
+	}
+	(void)fprintf(stderr, "\n");
+}
+#endif