[apple/libc.git] / db / hash / hash_buf-fbsd.c

/*-
 * 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_buf.c	8.5 (Berkeley) 7/15/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/db/hash/hash_buf.c,v 1.7 2002/03/21 22:46:26 obrien Exp $");

/*
 * 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.h>
#include "hash.h"
#include "page.h"
#include "hash_extern.h"

static BUFHEAD *newbuf(HTAB *, u_int32_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)

/*
 * 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;
	u_int32_t addr;
	BUFHEAD *prev_bp;
	int newpage;	/* If prev_bp set, indicates a new overflow page. */
{
	BUFHEAD *bp;
	u_int32_t is_disk_mask;
	int is_disk, segment_ndx;
	SEGMENT segp;

	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;
	u_int32_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;
	u_int16_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 = (u_int16_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 = (u_int16_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);
}
Commit	Line	Data
224c7076 A	1	/*-
	2	* Copyright (c) 1990, 1993, 1994
	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* This code is derived from software contributed to Berkeley by
	6	* Margo Seltzer.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
	16	* 3. All advertising materials mentioning features or use of this software
	17	* must display the following acknowledgement:
	18	* This product includes software developed by the University of
	19	* California, Berkeley and its contributors.
	20	* 4. Neither the name of the University nor the names of its contributors
	21	* may be used to endorse or promote products derived from this software
	22	* without specific prior written permission.
	23	*
	24	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	25	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	28	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	29	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	30	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	31	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	32	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	33	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	34	* SUCH DAMAGE.
	35	*/
	36
	37	#if defined(LIBC_SCCS) && !defined(lint)
	38	static char sccsid[] = "@(#)hash_buf.c 8.5 (Berkeley) 7/15/94";
	39	#endif /* LIBC_SCCS and not lint */
	40	#include <sys/cdefs.h>
	41	__FBSDID("$FreeBSD: src/lib/libc/db/hash/hash_buf.c,v 1.7 2002/03/21 22:46:26 obrien Exp $");
	42
	43	/*
	44	* PACKAGE: hash
	45	*
	46	* DESCRIPTION:
	47	* Contains buffer management
	48	*
	49	* ROUTINES:
	50	* External
	51	* __buf_init
	52	* __get_buf
	53	* __buf_free
	54	* __reclaim_buf
	55	* Internal
	56	* newbuf
	57	*/
	58
	59	#include <sys/param.h>
	60
	61	#include <stddef.h>
	62	#include <stdio.h>
	63	#include <stdlib.h>
	64
65	#ifdef DEBUG
66	#include <assert.h>
67	#endif
68
69	#include <db.h>
70	#include "hash.h"
71	#include "page.h"
72	#include "hash_extern.h"
73
74	static BUFHEAD newbuf(HTAB , u_int32_t, BUFHEAD *);
75
76	/* Unlink B from its place in the lru */
77	#define BUF_REMOVE(B) { \
78	(B)->prev->next = (B)->next; \
79	(B)->next->prev = (B)->prev; \
80	}
81
82	/* Insert B after P */
83	#define BUF_INSERT(B, P) { \
84	(B)->next = (P)->next; \
85	(B)->prev = (P); \
86	(P)->next = (B); \
87	(B)->next->prev = (B); \
88	}
89
90	#define MRU hashp->bufhead.next
91	#define LRU hashp->bufhead.prev
92
93	#define MRU_INSERT(B) BUF_INSERT((B), &hashp->bufhead)
94	#define LRU_INSERT(B) BUF_INSERT((B), LRU)
95
96	/*
97	* We are looking for a buffer with address "addr". If prev_bp is NULL, then
98	* address is a bucket index. If prev_bp is not NULL, then it points to the
99	* page previous to an overflow page that we are trying to find.
100	*
101	* CAVEAT: The buffer header accessed via prev_bp's ovfl field may no longer
102	* be valid. Therefore, you must always verify that its address matches the
103	* address you are seeking.
104	*/
105	extern BUFHEAD *
106	__get_buf(hashp, addr, prev_bp, newpage)
107	HTAB *hashp;
108	u_int32_t addr;
109	BUFHEAD *prev_bp;
110	int newpage; /* If prev_bp set, indicates a new overflow page. */
111	{
112	BUFHEAD *bp;
113	u_int32_t is_disk_mask;
114	int is_disk, segment_ndx;
115	SEGMENT segp;
116
117	is_disk = 0;
118	is_disk_mask = 0;
119	if (prev_bp) {
120	bp = prev_bp->ovfl;
121	if (!bp \|\| (bp->addr != addr))
122	bp = NULL;
123	if (!newpage)
124	is_disk = BUF_DISK;
125	} else {
126	/* Grab buffer out of directory */
127	segment_ndx = addr & (hashp->SGSIZE - 1);
128
129	/* valid segment ensured by __call_hash() */
130	segp = hashp->dir[addr >> hashp->SSHIFT];
131	#ifdef DEBUG
132	assert(segp != NULL);
133	#endif
134	bp = PTROF(segp[segment_ndx]);
135	is_disk_mask = ISDISK(segp[segment_ndx]);
136	is_disk = is_disk_mask \|\| !hashp->new_file;
137	}
138
139	if (!bp) {
140	bp = newbuf(hashp, addr, prev_bp);
141	if (!bp \|\|
142	__get_page(hashp, bp->page, addr, !prev_bp, is_disk, 0))
143	return (NULL);
144	if (!prev_bp)
145	segp[segment_ndx] =
146	(BUFHEAD *)((ptrdiff_t)bp \| is_disk_mask);
147	} else {
148	BUF_REMOVE(bp);
149	MRU_INSERT(bp);
150	}
151	return (bp);
152	}
153
154	/*
155	* We need a buffer for this page. Either allocate one, or evict a resident
156	* one (if we have as many buffers as we're allowed) and put this one in.
157	*
158	* If newbuf finds an error (returning NULL), it also sets errno.
159	*/
160	static BUFHEAD *
161	newbuf(hashp, addr, prev_bp)
162	HTAB *hashp;
163	u_int32_t addr;
164	BUFHEAD *prev_bp;
165	{
166	BUFHEAD bp; / The buffer we're going to use */
167	BUFHEAD xbp; / Temp pointer */
168	BUFHEAD *next_xbp;
169	SEGMENT segp;
170	int segment_ndx;
171	u_int16_t oaddr, *shortp;
172
173	oaddr = 0;
174	bp = LRU;
175	/*
176	* If LRU buffer is pinned, the buffer pool is too small. We need to
177	* allocate more buffers.
178	*/
179	if (hashp->nbufs \|\| (bp->flags & BUF_PIN)) {
180	/* Allocate a new one */
181	if ((bp = (BUFHEAD *)malloc(sizeof(BUFHEAD))) == NULL)
182	return (NULL);
183	#ifdef PURIFY
184	memset(bp, 0xff, sizeof(BUFHEAD));
185	#endif
186	if ((bp->page = (char *)malloc(hashp->BSIZE)) == NULL) {
187	free(bp);
188	return (NULL);
189	}
190	#ifdef PURIFY
191	memset(bp->page, 0xff, hashp->BSIZE);
192	#endif
193	if (hashp->nbufs)
194	hashp->nbufs--;
195	} else {
196	/* Kick someone out */
197	BUF_REMOVE(bp);
198	/*
199	* If this is an overflow page with addr 0, it's already been
200	* flushed back in an overflow chain and initialized.
201	*/
202	if ((bp->addr != 0) \|\| (bp->flags & BUF_BUCKET)) {
203	/*
204	* Set oaddr before __put_page so that you get it
205	* before bytes are swapped.
206	*/
207	shortp = (u_int16_t *)bp->page;
208	if (shortp[0])
209	oaddr = shortp[shortp[0] - 1];
210	if ((bp->flags & BUF_MOD) && __put_page(hashp, bp->page,
211	bp->addr, (int)IS_BUCKET(bp->flags), 0))
212	return (NULL);
213	/*
214	* Update the pointer to this page (i.e. invalidate it).
215	*
216	* If this is a new file (i.e. we created it at open
217	* time), make sure that we mark pages which have been
218	* written to disk so we retrieve them from disk later,
219	* rather than allocating new pages.
220	*/
221	if (IS_BUCKET(bp->flags)) {
222	segment_ndx = bp->addr & (hashp->SGSIZE - 1);
223	segp = hashp->dir[bp->addr >> hashp->SSHIFT];
224	#ifdef DEBUG
225	assert(segp != NULL);
226	#endif
227
228	if (hashp->new_file &&
229	((bp->flags & BUF_MOD) \|\|
230	ISDISK(segp[segment_ndx])))
231	segp[segment_ndx] = (BUFHEAD *)BUF_DISK;
232	else
233	segp[segment_ndx] = NULL;
234	}
235	/*
236	* Since overflow pages can only be access by means of
237	* their bucket, free overflow pages associated with
238	* this bucket.
239	*/
240	for (xbp = bp; xbp->ovfl;) {
241	next_xbp = xbp->ovfl;
242	xbp->ovfl = 0;
243	xbp = next_xbp;
244
245	/* Check that ovfl pointer is up date. */
246	if (IS_BUCKET(xbp->flags) \|\|
247	(oaddr != xbp->addr))
248	break;
249
250	shortp = (u_int16_t *)xbp->page;
251	if (shortp[0])
252	/* set before __put_page */
253	oaddr = shortp[shortp[0] - 1];
254	if ((xbp->flags & BUF_MOD) && __put_page(hashp,
255	xbp->page, xbp->addr, 0, 0))
256	return (NULL);
257	xbp->addr = 0;
258	xbp->flags = 0;
259	BUF_REMOVE(xbp);
260	LRU_INSERT(xbp);
261	}
262	}
263	}
264
265	/* Now assign this buffer */
266	bp->addr = addr;
267	#ifdef DEBUG1
268	(void)fprintf(stderr, "NEWBUF1: %d->ovfl was %d is now %d\n",
269	bp->addr, (bp->ovfl ? bp->ovfl->addr : 0), 0);
270	#endif
271	bp->ovfl = NULL;
272	if (prev_bp) {
273	/*
274	* If prev_bp is set, this is an overflow page, hook it in to
275	* the buffer overflow links.
276	*/
277	#ifdef DEBUG1
278	(void)fprintf(stderr, "NEWBUF2: %d->ovfl was %d is now %d\n",
279	prev_bp->addr, (prev_bp->ovfl ? bp->ovfl->addr : 0),
280	(bp ? bp->addr : 0));
281	#endif
282	prev_bp->ovfl = bp;
283	bp->flags = 0;
284	} else
285	bp->flags = BUF_BUCKET;
286	MRU_INSERT(bp);
287	return (bp);
288	}
289
290	extern void
291	__buf_init(hashp, nbytes)
292	HTAB *hashp;
293	int nbytes;
294	{
295	BUFHEAD *bfp;
296	int npages;
297
298	bfp = &(hashp->bufhead);
299	npages = (nbytes + hashp->BSIZE - 1) >> hashp->BSHIFT;
300	npages = MAX(npages, MIN_BUFFERS);
301
302	hashp->nbufs = npages;
303	bfp->next = bfp;
304	bfp->prev = bfp;
305	/*
306	* This space is calloc'd so these are already null.
307	*
308	* bfp->ovfl = NULL;
309	* bfp->flags = 0;
310	* bfp->page = NULL;
311	* bfp->addr = 0;
312	*/
313	}
314
315	extern int
316	__buf_free(hashp, do_free, to_disk)
317	HTAB *hashp;
318	int do_free, to_disk;
319	{
320	BUFHEAD *bp;
321
322	/* Need to make sure that buffer manager has been initialized */
323	if (!LRU)
324	return (0);
325	for (bp = LRU; bp != &hashp->bufhead;) {
326	/* Check that the buffer is valid */
327	if (bp->addr \|\| IS_BUCKET(bp->flags)) {
328	if (to_disk && (bp->flags & BUF_MOD) &&
329	__put_page(hashp, bp->page,
330	bp->addr, IS_BUCKET(bp->flags), 0))
331	return (-1);
332	}
333	/* Check if we are freeing stuff */
334	if (do_free) {
335	if (bp->page)
336	free(bp->page);
337	BUF_REMOVE(bp);
338	free(bp);
339	bp = LRU;
340	} else
341	bp = bp->prev;
342	}
343	return (0);
344	}
345
346	extern void
347	__reclaim_buf(hashp, bp)
348	HTAB *hashp;
349	BUFHEAD *bp;
350	{
351	bp->ovfl = 0;
352	bp->addr = 0;
353	bp->flags = 0;
354	BUF_REMOVE(bp);
355	LRU_INSERT(bp);
356	}