Apply FreeBSD-SA-09:07.libc - fix information leak in db(3)
[dragonfly.git] / lib / libc / db / mpool / mpool.c
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1/*-
2 * Copyright (c) 1990, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
cbebfd39 13 * 3. Neither the name of the University nor the names of its contributors
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14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $FreeBSD: src/lib/libc/db/mpool/mpool.c,v 1.5.2.1 2001/03/05 23:05:01 obrien Exp $
17d47efc 30 * $DragonFly: src/lib/libc/db/mpool/mpool.c,v 1.7 2005/11/19 20:46:32 swildner Exp $
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31 *
32 * @(#)mpool.c 8.5 (Berkeley) 7/26/94
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33 */
34
17ea2221 35#include "namespace.h"
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36#include <sys/param.h>
37#include <sys/queue.h>
38#include <sys/stat.h>
39
40#include <errno.h>
41#include <stdio.h>
42#include <stdlib.h>
43#include <string.h>
44#include <unistd.h>
17ea2221 45#include "un-namespace.h"
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46
47#include <db.h>
48
49#define __MPOOLINTERFACE_PRIVATE
50#include <mpool.h>
51
064e1fb3
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52static BKT *mpool_bkt (MPOOL *);
53static BKT *mpool_look (MPOOL *, pgno_t);
54static int mpool_write (MPOOL *, BKT *);
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55
56/*
57 * mpool_open --
58 * Initialize a memory pool.
59 */
60MPOOL *
17d47efc 61mpool_open(void *key __unused, int fd, pgno_t pagesize, pgno_t maxcache)
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62{
63 struct stat sb;
64 MPOOL *mp;
65 int entry;
66
67 /*
68 * Get information about the file.
69 *
70 * XXX
71 * We don't currently handle pipes, although we should.
72 */
17ea2221 73 if (_fstat(fd, &sb))
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74 return (NULL);
75 if (!S_ISREG(sb.st_mode)) {
76 errno = ESPIPE;
77 return (NULL);
78 }
79
80 /* Allocate and initialize the MPOOL cookie. */
81 if ((mp = (MPOOL *)calloc(1, sizeof(MPOOL))) == NULL)
82 return (NULL);
83 TAILQ_INIT(&mp->lqh);
84 for (entry = 0; entry < HASHSIZE; ++entry)
85 TAILQ_INIT(&mp->hqh[entry]);
86 mp->maxcache = maxcache;
87 mp->npages = sb.st_size / pagesize;
88 mp->pagesize = pagesize;
89 mp->fd = fd;
90 return (mp);
91}
92
93/*
94 * mpool_filter --
95 * Initialize input/output filters.
96 */
97void
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98mpool_filter(MPOOL *mp, void (*pgin)(void *, pgno_t, void *),
99 void (*pgout)(void *, pgno_t, void *), void *pgcookie)
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100{
101 mp->pgin = pgin;
102 mp->pgout = pgout;
103 mp->pgcookie = pgcookie;
104}
105
106/*
107 * mpool_new --
108 * Get a new page of memory.
109 */
110void *
c9fbf0d3 111mpool_new(MPOOL *mp, pgno_t *pgnoaddr)
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112{
113 struct _hqh *head;
114 BKT *bp;
115
116 if (mp->npages == MAX_PAGE_NUMBER) {
c9fbf0d3 117 fprintf(stderr, "mpool_new: page allocation overflow.\n");
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118 abort();
119 }
120#ifdef STATISTICS
121 ++mp->pagenew;
122#endif
123 /*
124 * Get a BKT from the cache. Assign a new page number, attach
125 * it to the head of the hash chain, the tail of the lru chain,
126 * and return.
127 */
128 if ((bp = mpool_bkt(mp)) == NULL)
129 return (NULL);
130 *pgnoaddr = bp->pgno = mp->npages++;
131 bp->flags = MPOOL_PINNED;
132
133 head = &mp->hqh[HASHKEY(bp->pgno)];
134 TAILQ_INSERT_HEAD(head, bp, hq);
135 TAILQ_INSERT_TAIL(&mp->lqh, bp, q);
136 return (bp->page);
137}
138
139/*
140 * mpool_get
141 * Get a page.
142 */
143void *
17d47efc 144mpool_get(MPOOL *mp, pgno_t pgno, u_int flags __unused)
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145{
146 struct _hqh *head;
147 BKT *bp;
148 off_t off;
149 int nr;
150
151 /* Check for attempt to retrieve a non-existent page. */
152 if (pgno >= mp->npages) {
153 errno = EINVAL;
154 return (NULL);
155 }
156
157#ifdef STATISTICS
158 ++mp->pageget;
159#endif
160
161 /* Check for a page that is cached. */
162 if ((bp = mpool_look(mp, pgno)) != NULL) {
163#ifdef DEBUG
164 if (bp->flags & MPOOL_PINNED) {
c9fbf0d3 165 fprintf(stderr,
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166 "mpool_get: page %d already pinned\n", bp->pgno);
167 abort();
168 }
169#endif
170 /*
171 * Move the page to the head of the hash chain and the tail
172 * of the lru chain.
173 */
174 head = &mp->hqh[HASHKEY(bp->pgno)];
175 TAILQ_REMOVE(head, bp, hq);
176 TAILQ_INSERT_HEAD(head, bp, hq);
177 TAILQ_REMOVE(&mp->lqh, bp, q);
178 TAILQ_INSERT_TAIL(&mp->lqh, bp, q);
179
180 /* Return a pinned page. */
181 bp->flags |= MPOOL_PINNED;
182 return (bp->page);
183 }
184
185 /* Get a page from the cache. */
186 if ((bp = mpool_bkt(mp)) == NULL)
187 return (NULL);
188
189 /* Read in the contents. */
190#ifdef STATISTICS
191 ++mp->pageread;
192#endif
193 off = mp->pagesize * pgno;
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194 nr = pread(mp->fd, bp->page, mp->pagesize, off);
195 if (nr != mp->pagesize) {
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196 if (nr >= 0)
197 errno = EFTYPE;
198 return (NULL);
199 }
200
201 /* Set the page number, pin the page. */
202 bp->pgno = pgno;
203 bp->flags = MPOOL_PINNED;
204
205 /*
206 * Add the page to the head of the hash chain and the tail
207 * of the lru chain.
208 */
209 head = &mp->hqh[HASHKEY(bp->pgno)];
210 TAILQ_INSERT_HEAD(head, bp, hq);
211 TAILQ_INSERT_TAIL(&mp->lqh, bp, q);
212
213 /* Run through the user's filter. */
214 if (mp->pgin != NULL)
215 (mp->pgin)(mp->pgcookie, bp->pgno, bp->page);
216
217 return (bp->page);
218}
219
220/*
221 * mpool_put
222 * Return a page.
223 */
224int
17d47efc 225mpool_put(MPOOL *mp __unused, void *page, u_int flags)
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226{
227 BKT *bp;
228
229#ifdef STATISTICS
230 ++mp->pageput;
231#endif
232 bp = (BKT *)((char *)page - sizeof(BKT));
233#ifdef DEBUG
234 if (!(bp->flags & MPOOL_PINNED)) {
c9fbf0d3 235 fprintf(stderr,
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236 "mpool_put: page %d not pinned\n", bp->pgno);
237 abort();
238 }
239#endif
240 bp->flags &= ~MPOOL_PINNED;
241 bp->flags |= flags & MPOOL_DIRTY;
242 return (RET_SUCCESS);
243}
244
245/*
246 * mpool_close
247 * Close the buffer pool.
248 */
249int
c9fbf0d3 250mpool_close(MPOOL *mp)
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251{
252 BKT *bp;
253
254 /* Free up any space allocated to the lru pages. */
255 while (!TAILQ_EMPTY(&mp->lqh)) {
256 bp = TAILQ_FIRST(&mp->lqh);
257 TAILQ_REMOVE(&mp->lqh, bp, q);
258 free(bp);
259 }
260
261 /* Free the MPOOL cookie. */
262 free(mp);
263 return (RET_SUCCESS);
264}
265
266/*
267 * mpool_sync
268 * Sync the pool to disk.
269 */
270int
c9fbf0d3 271mpool_sync(MPOOL *mp)
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272{
273 BKT *bp;
274
275 /* Walk the lru chain, flushing any dirty pages to disk. */
276 TAILQ_FOREACH(bp, &mp->lqh, q)
277 if (bp->flags & MPOOL_DIRTY &&
278 mpool_write(mp, bp) == RET_ERROR)
279 return (RET_ERROR);
280
281 /* Sync the file descriptor. */
282 return (_fsync(mp->fd) ? RET_ERROR : RET_SUCCESS);
283}
284
285/*
286 * mpool_bkt
287 * Get a page from the cache (or create one).
288 */
289static BKT *
c9fbf0d3 290mpool_bkt(MPOOL *mp)
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291{
292 struct _hqh *head;
293 BKT *bp;
294
295 /* If under the max cached, always create a new page. */
296 if (mp->curcache < mp->maxcache)
297 goto new;
298
299 /*
300 * If the cache is max'd out, walk the lru list for a buffer we
301 * can flush. If we find one, write it (if necessary) and take it
302 * off any lists. If we don't find anything we grow the cache anyway.
303 * The cache never shrinks.
304 */
305 TAILQ_FOREACH(bp, &mp->lqh, q)
306 if (!(bp->flags & MPOOL_PINNED)) {
307 /* Flush if dirty. */
308 if (bp->flags & MPOOL_DIRTY &&
309 mpool_write(mp, bp) == RET_ERROR)
310 return (NULL);
311#ifdef STATISTICS
312 ++mp->pageflush;
313#endif
314 /* Remove from the hash and lru queues. */
315 head = &mp->hqh[HASHKEY(bp->pgno)];
316 TAILQ_REMOVE(head, bp, hq);
317 TAILQ_REMOVE(&mp->lqh, bp, q);
318#ifdef DEBUG
319 { void *spage;
320 spage = bp->page;
321 memset(bp, 0xff, sizeof(BKT) + mp->pagesize);
322 bp->page = spage;
323 }
324#endif
325 return (bp);
326 }
327
7895edcd 328new: if ((bp = (BKT *)calloc(1, sizeof(BKT) + mp->pagesize)) == NULL)
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329 return (NULL);
330#ifdef STATISTICS
331 ++mp->pagealloc;
332#endif
333#if defined(DEBUG) || defined(PURIFY)
334 memset(bp, 0xff, sizeof(BKT) + mp->pagesize);
335#endif
336 bp->page = (char *)bp + sizeof(BKT);
337 ++mp->curcache;
338 return (bp);
339}
340
341/*
342 * mpool_write
343 * Write a page to disk.
344 */
345static int
c9fbf0d3 346mpool_write(MPOOL *mp, BKT *bp)
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347{
348 off_t off;
349
350#ifdef STATISTICS
351 ++mp->pagewrite;
352#endif
353
354 /* Run through the user's filter. */
355 if (mp->pgout)
356 (mp->pgout)(mp->pgcookie, bp->pgno, bp->page);
357
358 off = mp->pagesize * bp->pgno;
380a1760 359 if (pwrite(mp->fd, bp->page, mp->pagesize, off) != mp->pagesize)
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360 return (RET_ERROR);
361
362 bp->flags &= ~MPOOL_DIRTY;
363 return (RET_SUCCESS);
364}
365
366/*
367 * mpool_look
368 * Lookup a page in the cache.
369 */
370static BKT *
c9fbf0d3 371mpool_look(MPOOL *mp, pgno_t pgno)
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372{
373 struct _hqh *head;
374 BKT *bp;
375
376 head = &mp->hqh[HASHKEY(pgno)];
377 TAILQ_FOREACH(bp, head, hq)
378 if (bp->pgno == pgno) {
379#ifdef STATISTICS
380 ++mp->cachehit;
381#endif
382 return (bp);
383 }
384#ifdef STATISTICS
385 ++mp->cachemiss;
386#endif
387 return (NULL);
388}
389
390#ifdef STATISTICS
391/*
392 * mpool_stat
393 * Print out cache statistics.
394 */
395void
c9fbf0d3 396mpool_stat(MPOOL *mp)
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397{
398 BKT *bp;
399 int cnt;
400 char *sep;
401
574005c4 402 fprintf(stderr, "%u pages in the file\n", mp->npages);
c9fbf0d3 403 fprintf(stderr,
574005c4 404 "page size %lu, caching %u pages of %u page max cache\n",
984263bc 405 mp->pagesize, mp->curcache, mp->maxcache);
c9fbf0d3 406 fprintf(stderr, "%lu page puts, %lu page gets, %lu page new\n",
984263bc 407 mp->pageput, mp->pageget, mp->pagenew);
c9fbf0d3 408 fprintf(stderr, "%lu page allocs, %lu page flushes\n",
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409 mp->pagealloc, mp->pageflush);
410 if (mp->cachehit + mp->cachemiss)
c9fbf0d3 411 fprintf(stderr,
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412 "%.0f%% cache hit rate (%lu hits, %lu misses)\n",
413 ((double)mp->cachehit / (mp->cachehit + mp->cachemiss))
414 * 100, mp->cachehit, mp->cachemiss);
c9fbf0d3 415 fprintf(stderr, "%lu page reads, %lu page writes\n",
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416 mp->pageread, mp->pagewrite);
417
418 sep = "";
419 cnt = 0;
420 TAILQ_FOREACH(bp, &mp->lqh, q) {
c9fbf0d3 421 fprintf(stderr, "%s%d", sep, bp->pgno);
984263bc 422 if (bp->flags & MPOOL_DIRTY)
c9fbf0d3 423 fprintf(stderr, "d");
984263bc 424 if (bp->flags & MPOOL_PINNED)
c9fbf0d3 425 fprintf(stderr, "P");
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426 if (++cnt == 10) {
427 sep = "\n";
428 cnt = 0;
429 } else
430 sep = ", ";
431
432 }
c9fbf0d3 433 fprintf(stderr, "\n");
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434}
435#endif