1 /*-
2 * See the file LICENSE for redistribution information.
3 *
4 * Copyright (c) 1996, 1997, 1998
5 * Sleepycat Software. All rights reserved.
6 */
7 /*
8 * Copyright (c) 1990, 1993, 1994, 1995, 1996
9 * Keith Bostic. All rights reserved.
10 */
11 /*
12 * Copyright (c) 1990, 1993, 1994, 1995
13 * The Regents of the University of California. All rights reserved.
14 *
15 * This code is derived from software contributed to Berkeley by
16 * Mike Olson.
17 *
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions
20 * are met:
21 * 1. Redistributions of source code must retain the above copyright
22 * notice, this list of conditions and the following disclaimer.
23 * 2. Redistributions in binary form must reproduce the above copyright
24 * notice, this list of conditions and the following disclaimer in the
25 * documentation and/or other materials provided with the distribution.
26 * 3. All advertising materials mentioning features or use of this software
27 * must display the following acknowledgement:
28 * This product includes software developed by the University of
29 * California, Berkeley and its contributors.
30 * 4. Neither the name of the University nor the names of its contributors
31 * may be used to endorse or promote products derived from this software
32 * without specific prior written permission.
33 *
34 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
35 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
36 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
37 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
38 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
39 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
40 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
41 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
42 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
43 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44 * SUCH DAMAGE.
45 */
46
47 #include "config.h"
48
49 #ifndef lint
50 static const char sccsid[] = "@(#)bt_page.c 10.17 (Sleepycat) 1/3/99";
51 #endif /* not lint */
52
53 #ifndef NO_SYSTEM_INCLUDES
54 #include <sys/types.h>
55
56 #include <errno.h>
57 #include <string.h>
58 #endif
59
60 #include "db_int.h"
61 #include "db_page.h"
62 #include "btree.h"
63
64 /*
65 * __bam_new --
66 * Get a new page, preferably from the freelist.
67 *
68 * PUBLIC: int __bam_new __P((DBC *, u_int32_t, PAGE **));
69 */
70 int
__bam_new(dbc,type,pagepp)71 __bam_new(dbc, type, pagepp)
72 DBC *dbc;
73 u_int32_t type;
74 PAGE **pagepp;
75 {
76 BTMETA *meta;
77 DB *dbp;
78 DB_LOCK metalock;
79 PAGE *h;
80 db_pgno_t pgno;
81 int ret;
82
83 dbp = dbc->dbp;
84 meta = NULL;
85 h = NULL;
86 metalock = LOCK_INVALID;
87
88 pgno = PGNO_METADATA;
89 if ((ret = __bam_lget(dbc, 0, pgno, DB_LOCK_WRITE, &metalock)) != 0)
90 goto err;
91 if ((ret = memp_fget(dbp->mpf, &pgno, 0, (PAGE **)&meta)) != 0)
92 goto err;
93
94 if (meta->free == PGNO_INVALID) {
95 if ((ret = memp_fget(dbp->mpf, &pgno, DB_MPOOL_NEW, &h)) != 0)
96 goto err;
97 ZERO_LSN(h->lsn);
98 h->pgno = pgno;
99 } else {
100 pgno = meta->free;
101 if ((ret = memp_fget(dbp->mpf, &pgno, 0, &h)) != 0)
102 goto err;
103 meta->free = h->next_pgno;
104 }
105
106 /* Log the change. */
107 if (DB_LOGGING(dbc)) {
108 if ((ret = __bam_pg_alloc_log(dbp->dbenv->lg_info, dbc->txn,
109 &meta->lsn, 0, dbp->log_fileid, &meta->lsn, &h->lsn,
110 h->pgno, (u_int32_t)type, meta->free)) != 0)
111 goto err;
112 LSN(h) = LSN(meta);
113 }
114
115 (void)memp_fput(dbp->mpf, (PAGE *)meta, DB_MPOOL_DIRTY);
116 (void)__BT_TLPUT(dbc, metalock);
117
118 P_INIT(h, dbp->pgsize, h->pgno, PGNO_INVALID, PGNO_INVALID, 0, type);
119 *pagepp = h;
120 return (0);
121
122 err: if (h != NULL)
123 (void)memp_fput(dbp->mpf, h, 0);
124 if (meta != NULL)
125 (void)memp_fput(dbp->mpf, meta, 0);
126 if (metalock != LOCK_INVALID)
127 (void)__BT_TLPUT(dbc, metalock);
128 return (ret);
129 }
130
131 /*
132 * __bam_lput --
133 * The standard lock put call.
134 *
135 * PUBLIC: int __bam_lput __P((DBC *, DB_LOCK));
136 */
137 int
__bam_lput(dbc,lock)138 __bam_lput(dbc, lock)
139 DBC *dbc;
140 DB_LOCK lock;
141 {
142 return (__BT_LPUT(dbc, lock));
143 }
144
145 /*
146 * __bam_free --
147 * Add a page to the head of the freelist.
148 *
149 * PUBLIC: int __bam_free __P((DBC *, PAGE *));
150 */
151 int
__bam_free(dbc,h)152 __bam_free(dbc, h)
153 DBC *dbc;
154 PAGE *h;
155 {
156 BTMETA *meta;
157 DB *dbp;
158 DBT ldbt;
159 DB_LOCK metalock;
160 db_pgno_t pgno;
161 u_int32_t dirty_flag;
162 int ret, t_ret;
163
164 dbp = dbc->dbp;
165
166 /*
167 * Retrieve the metadata page and insert the page at the head of
168 * the free list. If either the lock get or page get routines
169 * fail, then we need to put the page with which we were called
170 * back because our caller assumes we take care of it.
171 */
172 dirty_flag = 0;
173 pgno = PGNO_METADATA;
174 if ((ret = __bam_lget(dbc, 0, pgno, DB_LOCK_WRITE, &metalock)) != 0)
175 goto err;
176 if ((ret = memp_fget(dbp->mpf, &pgno, 0, (PAGE **)&meta)) != 0) {
177 (void)__BT_TLPUT(dbc, metalock);
178 goto err;
179 }
180
181 /* Log the change. */
182 if (DB_LOGGING(dbc)) {
183 memset(&ldbt, 0, sizeof(ldbt));
184 ldbt.data = h;
185 ldbt.size = P_OVERHEAD;
186 if ((ret = __bam_pg_free_log(dbp->dbenv->lg_info,
187 dbc->txn, &meta->lsn, 0, dbp->log_fileid, h->pgno,
188 &meta->lsn, &ldbt, meta->free)) != 0) {
189 (void)memp_fput(dbp->mpf, (PAGE *)meta, 0);
190 (void)__BT_TLPUT(dbc, metalock);
191 return (ret);
192 }
193 LSN(h) = LSN(meta);
194 }
195
196 /*
197 * The page should have nothing interesting on it, re-initialize it,
198 * leaving only the page number and the LSN.
199 */
200 #ifdef DIAGNOSTIC
201 { db_pgno_t __pgno; DB_LSN __lsn;
202 __pgno = h->pgno;
203 __lsn = h->lsn;
204 memset(h, 0xdb, dbp->pgsize);
205 h->pgno = __pgno;
206 h->lsn = __lsn;
207 }
208 #endif
209 P_INIT(h, dbp->pgsize, h->pgno, PGNO_INVALID, meta->free, 0, P_INVALID);
210
211 /* Link the page on the metadata free list. */
212 meta->free = h->pgno;
213
214 /* Discard the metadata page. */
215 ret = memp_fput(dbp->mpf, (PAGE *)meta, DB_MPOOL_DIRTY);
216 if ((t_ret = __BT_TLPUT(dbc, metalock)) != 0)
217 ret = t_ret;
218
219 /* Discard the caller's page reference. */
220 dirty_flag = DB_MPOOL_DIRTY;
221 err: if ((t_ret = memp_fput(dbp->mpf, h, dirty_flag)) != 0 && ret == 0)
222 ret = t_ret;
223
224 /*
225 * XXX
226 * We have to unlock the caller's page in the caller!
227 */
228 return (ret);
229 }
230
231 #ifdef DEBUG
232 /*
233 * __bam_lt --
234 * Print out the list of locks currently held by a cursor.
235 *
236 * PUBLIC: int __bam_lt __P((DBC *));
237 */
238 int
__bam_lt(dbc)239 __bam_lt(dbc)
240 DBC *dbc;
241 {
242 DB *dbp;
243 DB_LOCKREQ req;
244
245 dbp = dbc->dbp;
246 if (F_ISSET(dbp, DB_AM_LOCKING)) {
247 req.op = DB_LOCK_DUMP;
248 lock_vec(dbp->dbenv->lk_info, dbc->locker, 0, &req, 1, NULL);
249 }
250 return (0);
251 }
252 #endif
253
254 /*
255 * __bam_lget --
256 * The standard lock get call.
257 *
258 * PUBLIC: int __bam_lget
259 * PUBLIC: __P((DBC *, int, db_pgno_t, db_lockmode_t, DB_LOCK *));
260 */
261 int
__bam_lget(dbc,do_couple,pgno,mode,lockp)262 __bam_lget(dbc, do_couple, pgno, mode, lockp)
263 DBC *dbc;
264 int do_couple;
265 db_pgno_t pgno;
266 db_lockmode_t mode;
267 DB_LOCK *lockp;
268 {
269 DB *dbp;
270 DB_LOCKREQ couple[2];
271 int ret;
272
273 dbp = dbc->dbp;
274
275 if (!F_ISSET(dbp, DB_AM_LOCKING)) {
276 *lockp = LOCK_INVALID;
277 return (0);
278 }
279
280 dbc->lock.pgno = pgno;
281
282 /*
283 * If the object not currently locked, acquire the lock and return,
284 * otherwise, lock couple. If we fail and it's not a system error,
285 * convert to EAGAIN.
286 */
287 if (do_couple) {
288 couple[0].op = DB_LOCK_GET;
289 couple[0].obj = &dbc->lock_dbt;
290 couple[0].mode = mode;
291 couple[1].op = DB_LOCK_PUT;
292 couple[1].lock = *lockp;
293
294 if (dbc->txn == NULL)
295 ret = lock_vec(dbp->dbenv->lk_info,
296 dbc->locker, 0, couple, 2, NULL);
297 else
298 ret = lock_tvec(dbp->dbenv->lk_info,
299 dbc->txn, 0, couple, 2, NULL);
300 if (ret != 0) {
301 /* If we fail, discard the lock we held. */
302 __BT_LPUT(dbc, *lockp);
303
304 return (ret < 0 ? EAGAIN : ret);
305 }
306 *lockp = couple[0].lock;
307 } else {
308 if (dbc->txn == NULL)
309 ret = lock_get(dbp->dbenv->lk_info,
310 dbc->locker, 0, &dbc->lock_dbt, mode, lockp);
311 else
312 ret = lock_tget(dbp->dbenv->lk_info,
313 dbc->txn, 0, &dbc->lock_dbt, mode, lockp);
314 return (ret < 0 ? EAGAIN : ret);
315 }
316 return (0);
317 }
318