newlib/libc/search/hash_buf.c - native_client/nacl-newlib - Git at Google

 /*-
  * 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.
  */

 #include <sys/param.h>
 #if defined(LIBC_SCCS) && !defined(lint)
 static char sccsid[] = "@(#)hash_buf.c	8.5 (Berkeley) 7/15/94";
 #endif /* LIBC_SCCS and not lint */
 #include <sys/cdefs.h>

 /*
  * PACKAGE: hash
  *
  * DESCRIPTION:
  *	Contains buffer management
  *
  * ROUTINES:
  * External
  *	__buf_init
  *	__get_buf
  *	__buf_free
  *	__reclaim_buf
  * Internal
  *	newbuf
  */

 #include <sys/param.h>

 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>

 #ifdef DEBUG
 #include <assert.h>
 #endif

 #include "db_local.h"
 #include "hash.h"
 #include "page.h"
 #include "extern.h"

 static BUFHEAD *newbuf(HTAB *, __uint32_t, BUFHEAD *);

 /* Unlink B from its place in the lru */
 #define BUF_REMOVE(B) { \
 	(B)->prev->next = (B)->next; \
 	(B)->next->prev = (B)->prev; \
 }

 /* Insert B after P */
 #define BUF_INSERT(B, P) { \
 	(B)->next = (P)->next; \
 	(B)->prev = (P); \
 	(P)->next = (B); \
 	(B)->next->prev = (B); \
 }

 #define	MRU	hashp->bufhead.next
 #define	LRU	hashp->bufhead.prev

 #define MRU_INSERT(B)	BUF_INSERT((B), &hashp->bufhead)
 #define LRU_INSERT(B)	BUF_INSERT((B), LRU)

 /* Macros for min/max.  */
 #ifndef MIN
 #define MIN(a,b) (((a)<(b))?(a):(b))
 #endif
 #ifndef MAX
 #define MAX(a,b) (((a)>(b))?(a):(b))
 #endif

 /*
  * We are looking for a buffer with address "addr".  If prev_bp is NULL, then
  * address is a bucket index.  If prev_bp is not NULL, then it points to the
  * page previous to an overflow page that we are trying to find.
  *
  * CAVEAT:  The buffer header accessed via prev_bp's ovfl field may no longer
  * be valid.  Therefore, you must always verify that its address matches the
  * address you are seeking.
  */
 extern BUFHEAD *
 __get_buf(hashp, addr, prev_bp, newpage)
 	HTAB *hashp;
 	__uint32_t addr;
 	BUFHEAD *prev_bp;
 	int newpage;	/* If prev_bp set, indicates a new overflow page. */
 {
 	BUFHEAD *bp;
 	__uint32_t is_disk_mask;
 	int is_disk, segment_ndx = 0;
 	SEGMENT segp = NULL;

 	is_disk = 0;
 	is_disk_mask = 0;
 	if (prev_bp) {
 		bp = prev_bp->ovfl;
 		if (!bp || (bp->addr != addr))
 			bp = NULL;
 		if (!newpage)
 			is_disk = BUF_DISK;
 	} else {
 		/* Grab buffer out of directory */
 		segment_ndx = addr & (hashp->SGSIZE - 1);

 		/* valid segment ensured by __call_hash() */
 		segp = hashp->dir[addr >> hashp->SSHIFT];
 #ifdef DEBUG
 		assert(segp != NULL);
 #endif
 		bp = PTROF(segp[segment_ndx]);
 		is_disk_mask = ISDISK(segp[segment_ndx]);
 		is_disk = is_disk_mask || !hashp->new_file;
 	}

 	if (!bp) {
 		bp = newbuf(hashp, addr, prev_bp);
 		if (!bp ||
 		    __get_page(hashp, bp->page, addr, !prev_bp, is_disk, 0))
 			return (NULL);
 		if (!prev_bp)
 			segp[segment_ndx] =
 			    (BUFHEAD *)((ptrdiff_t)bp | is_disk_mask);
 	} else {
 		BUF_REMOVE(bp);
 		MRU_INSERT(bp);
 	}
 	return (bp);
 }

 /*
  * We need a buffer for this page. Either allocate one, or evict a resident
  * one (if we have as many buffers as we're allowed) and put this one in.
  *
  * If newbuf finds an error (returning NULL), it also sets errno.
  */
 static BUFHEAD *
 newbuf(hashp, addr, prev_bp)
 	HTAB *hashp;
 	__uint32_t addr;
 	BUFHEAD *prev_bp;
 {
 	BUFHEAD *bp;		/* The buffer we're going to use */
 	BUFHEAD *xbp;		/* Temp pointer */
 	BUFHEAD *next_xbp;
 	SEGMENT segp;
 	int segment_ndx;
 	__uint16_t oaddr, *shortp;

 	oaddr = 0;
 	bp = LRU;
 	/*
 	 * If LRU buffer is pinned, the buffer pool is too small. We need to
 	 * allocate more buffers.
 	 */
 	if (hashp->nbufs || (bp->flags & BUF_PIN)) {
 		/* Allocate a new one */
 		if ((bp = (BUFHEAD *)malloc(sizeof(BUFHEAD))) == NULL)
 			return (NULL);
 #ifdef PURIFY
 		memset(bp, 0xff, sizeof(BUFHEAD));
 #endif
 		if ((bp->page = (char *)malloc(hashp->BSIZE)) == NULL) {
 			free(bp);
 			return (NULL);
 		}
 #ifdef PURIFY
 		memset(bp->page, 0xff, hashp->BSIZE);
 #endif
 		if (hashp->nbufs)
 			hashp->nbufs--;
 	} else {
 		/* Kick someone out */
 		BUF_REMOVE(bp);
 		/*
 		 * If this is an overflow page with addr 0, it's already been
 		 * flushed back in an overflow chain and initialized.
 		 */
 		if ((bp->addr != 0) || (bp->flags & BUF_BUCKET)) {
 			/*
 			 * Set oaddr before __put_page so that you get it
 			 * before bytes are swapped.
 			 */
 			shortp = (__uint16_t *)bp->page;
 			if (shortp[0])
 				oaddr = shortp[shortp[0] - 1];
 			if ((bp->flags & BUF_MOD) && __put_page(hashp, bp->page,
 			    bp->addr, (int)IS_BUCKET(bp->flags), 0))
 				return (NULL);
 			/*
 			 * Update the pointer to this page (i.e. invalidate it).
 			 *
 			 * If this is a new file (i.e. we created it at open
 			 * time), make sure that we mark pages which have been
 			 * written to disk so we retrieve them from disk later,
 			 * rather than allocating new pages.
 			 */
 			if (IS_BUCKET(bp->flags)) {
 				segment_ndx = bp->addr & (hashp->SGSIZE - 1);
 				segp = hashp->dir[bp->addr >> hashp->SSHIFT];
 #ifdef DEBUG
 				assert(segp != NULL);
 #endif

 				if (hashp->new_file &&
 				    ((bp->flags & BUF_MOD) ||
 				    ISDISK(segp[segment_ndx])))
 					segp[segment_ndx] = (BUFHEAD *)BUF_DISK;
 				else
 					segp[segment_ndx] = NULL;
 			}
 			/*
 			 * Since overflow pages can only be access by means of
 			 * their bucket, free overflow pages associated with
 			 * this bucket.
 			 */
 			for (xbp = bp; xbp->ovfl;) {
 				next_xbp = xbp->ovfl;
 				xbp->ovfl = 0;
 				xbp = next_xbp;

 				/* Check that ovfl pointer is up date. */
 				if (IS_BUCKET(xbp->flags) ||
 				    (oaddr != xbp->addr))
 					break;

 				shortp = (__uint16_t *)xbp->page;
 				if (shortp[0])
 					/* set before __put_page */
 					oaddr = shortp[shortp[0] - 1];
 				if ((xbp->flags & BUF_MOD) && __put_page(hashp,
 				    xbp->page, xbp->addr, 0, 0))
 					return (NULL);
 				xbp->addr = 0;
 				xbp->flags = 0;
 				BUF_REMOVE(xbp);
 				LRU_INSERT(xbp);
 			}
 		}
 	}

 	/* Now assign this buffer */
 	bp->addr = addr;
 #ifdef DEBUG1
 	(void)fprintf(stderr, "NEWBUF1: %d->ovfl was %d is now %d\n",
 	    bp->addr, (bp->ovfl ? bp->ovfl->addr : 0), 0);
 #endif
 	bp->ovfl = NULL;
 	if (prev_bp) {
 		/*
 		 * If prev_bp is set, this is an overflow page, hook it in to
 		 * the buffer overflow links.
 		 */
 #ifdef DEBUG1
 		(void)fprintf(stderr, "NEWBUF2: %d->ovfl was %d is now %d\n",
 		    prev_bp->addr, (prev_bp->ovfl ? bp->ovfl->addr : 0),
 		    (bp ? bp->addr : 0));
 #endif
 		prev_bp->ovfl = bp;
 		bp->flags = 0;
 	} else
 		bp->flags = BUF_BUCKET;
 	MRU_INSERT(bp);
 	return (bp);
 }

 extern void
 __buf_init(hashp, nbytes)
 	HTAB *hashp;
 	int nbytes;
 {
 	BUFHEAD *bfp;
 	int npages;

 	bfp = &(hashp->bufhead);
 	npages = (nbytes + hashp->BSIZE - 1) >> hashp->BSHIFT;
 	npages = MAX(npages, MIN_BUFFERS);

 	hashp->nbufs = npages;
 	bfp->next = bfp;
 	bfp->prev = bfp;
 	/*
 	 * This space is calloc'd so these are already null.
 	 *
 	 * bfp->ovfl = NULL;
 	 * bfp->flags = 0;
 	 * bfp->page = NULL;
 	 * bfp->addr = 0;
 	 */
 }

 extern int
 __buf_free(hashp, do_free, to_disk)
 	HTAB *hashp;
 	int do_free, to_disk;
 {
 	BUFHEAD *bp;

 	/* Need to make sure that buffer manager has been initialized */
 	if (!LRU)
 		return (0);
 	for (bp = LRU; bp != &hashp->bufhead;) {
 		/* Check that the buffer is valid */
 		if (bp->addr || IS_BUCKET(bp->flags)) {
 			if (to_disk && (bp->flags & BUF_MOD) &&
 			    __put_page(hashp, bp->page,
 			    bp->addr, IS_BUCKET(bp->flags), 0))
 				return (-1);
 		}
 		/* Check if we are freeing stuff */
 		if (do_free) {
 			if (bp->page)
 				free(bp->page);
 			BUF_REMOVE(bp);
 			free(bp);
 			bp = LRU;
 		} else
 			bp = bp->prev;
 	}
 	return (0);
 }

 extern void
 __reclaim_buf(hashp, bp)
 	HTAB *hashp;
 	BUFHEAD *bp;
 {
 	bp->ovfl = 0;
 	bp->addr = 0;
 	bp->flags = 0;
 	BUF_REMOVE(bp);
 	LRU_INSERT(bp);
 }
	/*-
	* 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.
	*/

	#include <sys/param.h>
	#if defined(LIBC_SCCS) && !defined(lint)
	static char sccsid[] = "@(#)hash_buf.c 8.5 (Berkeley) 7/15/94";
	#endif /* LIBC_SCCS and not lint */
	#include <sys/cdefs.h>

	/*
	* PACKAGE: hash
	*
	* DESCRIPTION:
	* Contains buffer management
	*
	* ROUTINES:
	* External
	* __buf_init
	* __get_buf
	* __buf_free
	* __reclaim_buf
	* Internal
	* newbuf
	*/

	#include <sys/param.h>

	#include <stddef.h>
	#include <stdio.h>
	#include <stdlib.h>

	#ifdef DEBUG
	#include <assert.h>
	#endif

	#include "db_local.h"
	#include "hash.h"
	#include "page.h"
	#include "extern.h"

	static BUFHEAD newbuf(HTAB , __uint32_t, BUFHEAD *);

	/* Unlink B from its place in the lru */
	#define BUF_REMOVE(B) { \
	(B)->prev->next = (B)->next; \
	(B)->next->prev = (B)->prev; \
	}

	/* Insert B after P */
	#define BUF_INSERT(B, P) { \
	(B)->next = (P)->next; \
	(B)->prev = (P); \
	(P)->next = (B); \
	(B)->next->prev = (B); \
	}

	#define MRU hashp->bufhead.next
	#define LRU hashp->bufhead.prev

	#define MRU_INSERT(B) BUF_INSERT((B), &hashp->bufhead)
	#define LRU_INSERT(B) BUF_INSERT((B), LRU)

	/* Macros for min/max. */
	#ifndef MIN
	#define MIN(a,b) (((a)<(b))?(a):(b))
	#endif
	#ifndef MAX
	#define MAX(a,b) (((a)>(b))?(a):(b))
	#endif

	/*
	* We are looking for a buffer with address "addr". If prev_bp is NULL, then
	* address is a bucket index. If prev_bp is not NULL, then it points to the
	* page previous to an overflow page that we are trying to find.
	*
	* CAVEAT: The buffer header accessed via prev_bp's ovfl field may no longer
	* be valid. Therefore, you must always verify that its address matches the
	* address you are seeking.
	*/
	extern BUFHEAD *
	__get_buf(hashp, addr, prev_bp, newpage)
	HTAB *hashp;
	__uint32_t addr;
	BUFHEAD *prev_bp;
	int newpage; /* If prev_bp set, indicates a new overflow page. */
	{
	BUFHEAD *bp;
	__uint32_t is_disk_mask;
	int is_disk, segment_ndx = 0;
	SEGMENT segp = NULL;

	is_disk = 0;
	is_disk_mask = 0;
	if (prev_bp) {
	bp = prev_bp->ovfl;
	if (!bp \|\| (bp->addr != addr))
	bp = NULL;
	if (!newpage)
	is_disk = BUF_DISK;
	} else {
	/* Grab buffer out of directory */
	segment_ndx = addr & (hashp->SGSIZE - 1);

	/* valid segment ensured by __call_hash() */
	segp = hashp->dir[addr >> hashp->SSHIFT];
	#ifdef DEBUG
	assert(segp != NULL);
	#endif
	bp = PTROF(segp[segment_ndx]);
	is_disk_mask = ISDISK(segp[segment_ndx]);
	is_disk = is_disk_mask \|\| !hashp->new_file;
	}

	if (!bp) {
	bp = newbuf(hashp, addr, prev_bp);
	if (!bp \|\|
	__get_page(hashp, bp->page, addr, !prev_bp, is_disk, 0))
	return (NULL);
	if (!prev_bp)
	segp[segment_ndx] =
	(BUFHEAD *)((ptrdiff_t)bp \| is_disk_mask);
	} else {
	BUF_REMOVE(bp);
	MRU_INSERT(bp);
	}
	return (bp);
	}

	/*
	* We need a buffer for this page. Either allocate one, or evict a resident
	* one (if we have as many buffers as we're allowed) and put this one in.
	*
	* If newbuf finds an error (returning NULL), it also sets errno.
	*/
	static BUFHEAD *
	newbuf(hashp, addr, prev_bp)
	HTAB *hashp;
	__uint32_t addr;
	BUFHEAD *prev_bp;
	{
	BUFHEAD bp; / The buffer we're going to use */
	BUFHEAD xbp; / Temp pointer */
	BUFHEAD *next_xbp;
	SEGMENT segp;
	int segment_ndx;
	__uint16_t oaddr, *shortp;

	oaddr = 0;
	bp = LRU;
	/*
	* If LRU buffer is pinned, the buffer pool is too small. We need to
	* allocate more buffers.
	*/
	if (hashp->nbufs \|\| (bp->flags & BUF_PIN)) {
	/* Allocate a new one */
	if ((bp = (BUFHEAD *)malloc(sizeof(BUFHEAD))) == NULL)
	return (NULL);
	#ifdef PURIFY
	memset(bp, 0xff, sizeof(BUFHEAD));
	#endif
	if ((bp->page = (char *)malloc(hashp->BSIZE)) == NULL) {
	free(bp);
	return (NULL);
	}
	#ifdef PURIFY
	memset(bp->page, 0xff, hashp->BSIZE);
	#endif
	if (hashp->nbufs)
	hashp->nbufs--;
	} else {
	/* Kick someone out */
	BUF_REMOVE(bp);
	/*
	* If this is an overflow page with addr 0, it's already been
	* flushed back in an overflow chain and initialized.
	*/
	if ((bp->addr != 0) \|\| (bp->flags & BUF_BUCKET)) {
	/*
	* Set oaddr before __put_page so that you get it
	* before bytes are swapped.
	*/
	shortp = (__uint16_t *)bp->page;
	if (shortp[0])
	oaddr = shortp[shortp[0] - 1];
	if ((bp->flags & BUF_MOD) && __put_page(hashp, bp->page,
	bp->addr, (int)IS_BUCKET(bp->flags), 0))
	return (NULL);
	/*
	* Update the pointer to this page (i.e. invalidate it).
	*
	* If this is a new file (i.e. we created it at open
	* time), make sure that we mark pages which have been
	* written to disk so we retrieve them from disk later,
	* rather than allocating new pages.
	*/
	if (IS_BUCKET(bp->flags)) {
	segment_ndx = bp->addr & (hashp->SGSIZE - 1);
	segp = hashp->dir[bp->addr >> hashp->SSHIFT];
	#ifdef DEBUG
	assert(segp != NULL);
	#endif

	if (hashp->new_file &&
	((bp->flags & BUF_MOD) \|\|
	ISDISK(segp[segment_ndx])))
	segp[segment_ndx] = (BUFHEAD *)BUF_DISK;
	else
	segp[segment_ndx] = NULL;
	}
	/*
	* Since overflow pages can only be access by means of
	* their bucket, free overflow pages associated with
	* this bucket.
	*/
	for (xbp = bp; xbp->ovfl;) {
	next_xbp = xbp->ovfl;
	xbp->ovfl = 0;
	xbp = next_xbp;

	/* Check that ovfl pointer is up date. */
	if (IS_BUCKET(xbp->flags) \|\|
	(oaddr != xbp->addr))
	break;

	shortp = (__uint16_t *)xbp->page;
	if (shortp[0])
	/* set before __put_page */
	oaddr = shortp[shortp[0] - 1];
	if ((xbp->flags & BUF_MOD) && __put_page(hashp,
	xbp->page, xbp->addr, 0, 0))
	return (NULL);
	xbp->addr = 0;
	xbp->flags = 0;
	BUF_REMOVE(xbp);
	LRU_INSERT(xbp);
	}
	}
	}

	/* Now assign this buffer */
	bp->addr = addr;
	#ifdef DEBUG1
	(void)fprintf(stderr, "NEWBUF1: %d->ovfl was %d is now %d\n",
	bp->addr, (bp->ovfl ? bp->ovfl->addr : 0), 0);
	#endif
	bp->ovfl = NULL;
	if (prev_bp) {
	/*
	* If prev_bp is set, this is an overflow page, hook it in to
	* the buffer overflow links.
	*/
	#ifdef DEBUG1
	(void)fprintf(stderr, "NEWBUF2: %d->ovfl was %d is now %d\n",
	prev_bp->addr, (prev_bp->ovfl ? bp->ovfl->addr : 0),
	(bp ? bp->addr : 0));
	#endif
	prev_bp->ovfl = bp;
	bp->flags = 0;
	} else
	bp->flags = BUF_BUCKET;
	MRU_INSERT(bp);
	return (bp);
	}

	extern void
	__buf_init(hashp, nbytes)
	HTAB *hashp;
	int nbytes;
	{
	BUFHEAD *bfp;
	int npages;

	bfp = &(hashp->bufhead);
	npages = (nbytes + hashp->BSIZE - 1) >> hashp->BSHIFT;
	npages = MAX(npages, MIN_BUFFERS);

	hashp->nbufs = npages;
	bfp->next = bfp;
	bfp->prev = bfp;
	/*
	* This space is calloc'd so these are already null.
	*
	* bfp->ovfl = NULL;
	* bfp->flags = 0;
	* bfp->page = NULL;
	* bfp->addr = 0;
	*/
	}

	extern int
	__buf_free(hashp, do_free, to_disk)
	HTAB *hashp;
	int do_free, to_disk;
	{
	BUFHEAD *bp;

	/* Need to make sure that buffer manager has been initialized */
	if (!LRU)
	return (0);
	for (bp = LRU; bp != &hashp->bufhead;) {
	/* Check that the buffer is valid */
	if (bp->addr \|\| IS_BUCKET(bp->flags)) {
	if (to_disk && (bp->flags & BUF_MOD) &&
	__put_page(hashp, bp->page,
	bp->addr, IS_BUCKET(bp->flags), 0))
	return (-1);
	}
	/* Check if we are freeing stuff */
	if (do_free) {
	if (bp->page)
	free(bp->page);
	BUF_REMOVE(bp);
	free(bp);
	bp = LRU;
	} else
	bp = bp->prev;
	}
	return (0);
	}

	extern void
	__reclaim_buf(hashp, bp)
	HTAB *hashp;
	BUFHEAD *bp;
	{
	bp->ovfl = 0;
	bp->addr = 0;
	bp->flags = 0;
	BUF_REMOVE(bp);
	LRU_INSERT(bp);
	}