xref: /titanic_52/usr/src/cmd/sendmail/db/log/log_rec.c (revision b819cea2f73f98c5662230cc9affc8cc84f77fcf)
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) 1995, 1996
9  *	The President and Fellows of Harvard University.  All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the University of
22  *	California, Berkeley and its contributors.
23  * 4. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  */
39 
40 #include "config.h"
41 
42 #ifndef lint
43 static const char sccsid[] = "@(#)log_rec.c	10.26 (Sleepycat) 10/21/98";
44 #endif /* not lint */
45 
46 #ifndef NO_SYSTEM_INCLUDES
47 #include <sys/types.h>
48 
49 #include <errno.h>
50 #include <string.h>
51 #endif
52 
53 #include "db_int.h"
54 #include "shqueue.h"
55 #include "log.h"
56 #include "db_dispatch.h"
57 #include "common_ext.h"
58 
59 static int __log_do_open __P((DB_LOG *,
60     u_int8_t *, char *, DBTYPE, u_int32_t));
61 static int __log_lid_to_fname __P((DB_LOG *, u_int32_t, FNAME **));
62 static int __log_open_file __P((DB_LOG *, __log_register_args *));
63 
64 /*
65  * PUBLIC: int __log_register_recover
66  * PUBLIC:     __P((DB_LOG *, DBT *, DB_LSN *, int, void *));
67  */
68 int
69 __log_register_recover(logp, dbtp, lsnp, redo, info)
70 	DB_LOG *logp;
71 	DBT *dbtp;
72 	DB_LSN *lsnp;
73 	int redo;
74 	void *info;
75 {
76 	DB_ENTRY *dbe;
77 	__log_register_args *argp;
78 	int ret;
79 
80 #ifdef DEBUG_RECOVER
81 	__log_register_print(logp, dbtp, lsnp, redo, info);
82 #endif
83 	COMPQUIET(info, NULL);
84 	COMPQUIET(lsnp, NULL);
85 
86 	F_SET(logp, DBC_RECOVER);
87 
88 	if ((ret = __log_register_read(dbtp->data, &argp)) != 0)
89 		goto out;
90 
91 	if ((argp->opcode == LOG_CHECKPOINT && redo == TXN_OPENFILES) ||
92 	    (argp->opcode == LOG_OPEN &&
93 	    (redo == TXN_REDO || redo == TXN_OPENFILES ||
94 	     redo == TXN_FORWARD_ROLL)) ||
95 	    (argp->opcode == LOG_CLOSE &&
96 	    (redo == TXN_UNDO || redo == TXN_BACKWARD_ROLL))) {
97 		/*
98 		 * If we are redoing an open or undoing a close, then we need
99 		 * to open a file.
100 		 */
101 		ret = __log_open_file(logp, argp);
102 		if (ret == ENOENT) {
103 			if (redo == TXN_OPENFILES)
104 				__db_err(logp->dbenv, "warning: %s: %s",
105 				    argp->name.data, strerror(ENOENT));
106 			ret = 0;
107 		}
108 	} else if (argp->opcode != LOG_CHECKPOINT &&
109 	    argp->opcode != LOG_CLOSE) {
110 		/*
111 		 * If we are undoing an open, then we need to close the file.
112 		 * Note that we do *not* close the file if we are redoing a
113 		 * close, because we do not log the reference counts on log
114 		 * files and we may have had the file open multiple times,
115 		 * and therefore, this close should just dec a reference
116 		 * count.  However, since we only do one open during a
117 		 * checkpoint, this will inadvertently close the file.
118 		 *
119   		 * If the file is deleted, then we can just ignore this close.
120  		 * Otherwise, we should usually have a valid dbp we should
121   		 * close or whose reference count should be decremented.
122  		 * However, if we shut down without closing a file, we
123 		 * may, in fact, not have the file open, and that's OK.
124 		 */
125 		LOCK_LOGTHREAD(logp);
126 		if (argp->id < logp->dbentry_cnt) {
127 			dbe = &logp->dbentry[argp->id];
128 			if (dbe->dbp != NULL && --dbe->refcount == 0) {
129 				ret = dbe->dbp->close(dbe->dbp, 0);
130 				if (dbe->name != NULL) {
131 					__os_freestr(dbe->name);
132 					dbe->name = NULL;
133 				}
134 				(void)__log_rem_logid(logp, argp->id);
135 			}
136 		}
137 		UNLOCK_LOGTHREAD(logp);
138  	} else if (argp->opcode == LOG_CHECKPOINT && redo == TXN_UNDO &&
139  	    (argp->id >= logp->dbentry_cnt ||
140  	    (!logp->dbentry[argp->id].deleted &&
141  	    logp->dbentry[argp->id].dbp == NULL))) {
142  		/*
143  		 * It's a checkpoint and we are rolling backward.  It
144  		 * is possible that the system was shut down and thus
145  		 * ended with a stable checkpoint; this file was never
146  		 * closed and has therefore not been reopened yet.  If
147  		 * so, we need to try to open it.
148  		 */
149  		ret = __log_open_file(logp, argp);
150  		if (ret == ENOENT) {
151  			__db_err(logp->dbenv, "warning: %s: %s",
152 			    argp->name.data, strerror(ENOENT));
153  			ret = 0;
154  		}
155 	}
156 
157 out:	F_CLR(logp, DBC_RECOVER);
158 	if (argp != NULL)
159 		__os_free(argp, 0);
160 	return (ret);
161 }
162 
163 /* Hand coded routines. */
164 
165 /*
166  * Called during log_register recovery.  Make sure that we have an
167  * entry in the dbentry table for this ndx.
168  * Returns 0 on success, non-zero on error.
169  */
170 static int
171 __log_open_file(lp, argp)
172 	DB_LOG *lp;
173 	__log_register_args *argp;
174 {
175 	DB_ENTRY *dbe;
176 
177 	if (argp->name.size == 0)
178 		return(0);
179 
180 	/*
181 	 * Because of reference counting, we cannot automatically close files
182 	 * during recovery, so when we're opening, we have to check that the
183 	 * name we are opening is what we expect.  If it's not, then we close
184 	 * the old file and open the new one.
185 	 */
186 	LOCK_LOGTHREAD(lp);
187 	if (argp->id < lp->dbentry_cnt)
188 		dbe = &lp->dbentry[argp->id];
189 	else
190 		dbe = NULL;
191 
192 	if (dbe != NULL && (dbe->deleted == 1 || dbe->dbp != NULL) &&
193 	    dbe->name != NULL && argp->name.data != NULL &&
194 	    strncmp(argp->name.data, dbe->name, argp->name.size) == 0) {
195 
196 		dbe->refcount++;
197 		UNLOCK_LOGTHREAD(lp);
198 		return (0);
199 	}
200   	UNLOCK_LOGTHREAD(lp);
201 
202 	if (dbe != NULL && dbe->dbp != NULL) {
203                 (void)dbe->dbp->close(dbe->dbp, 0);
204 		if (dbe->name != NULL)
205 			__os_freestr(dbe->name);
206                 dbe->name = NULL;
207 		(void)__log_rem_logid(lp, argp->id);
208         }
209 
210 
211 	return (__log_do_open(lp,
212 	    argp->uid.data, argp->name.data, argp->ftype, argp->id));
213 }
214 
215 /*
216  * __log_do_open --
217  * 	Open files referenced in the log.  This is the part of the open that
218  * is not protected by the thread mutex.
219  */
220 
221 static int
222 __log_do_open(lp, uid, name, ftype, ndx)
223 	DB_LOG *lp;
224 	u_int8_t *uid;
225 	char *name;
226 	DBTYPE ftype;
227 	u_int32_t ndx;
228 {
229 	DB *dbp;
230 	int ret;
231 
232 	dbp = NULL;
233 	if ((ret = db_open(name, ftype, 0, 0, lp->dbenv, NULL, &dbp)) == 0) {
234 		/*
235 		 * Verify that we are opening the same file that we were
236 		 * referring to when we wrote this log record.
237 		 */
238 		if (memcmp(uid, dbp->fileid, DB_FILE_ID_LEN) != 0) {
239 			(void)dbp->close(dbp, 0);
240 			dbp = NULL;
241 			ret = ENOENT;
242 		}
243 	}
244 
245 	if (ret == 0 || ret == ENOENT)
246 		(void)__log_add_logid(lp, dbp, name, ndx);
247 
248 	return (ret);
249 }
250 
251 /*
252  * __log_add_logid --
253  *	Adds a DB entry to the log's DB entry table.
254  *
255  * PUBLIC: int __log_add_logid __P((DB_LOG *, DB *, const char *, u_int32_t));
256  */
257 int
258 __log_add_logid(logp, dbp, name, ndx)
259 	DB_LOG *logp;
260 	DB *dbp;
261 	const char *name;
262 	u_int32_t ndx;
263 {
264 	u_int32_t i;
265 	int ret;
266 
267 	ret = 0;
268 
269 	LOCK_LOGTHREAD(logp);
270 
271 	/*
272 	 * Check if we need to grow the table.  Note, ndx is 0-based (the
273 	 * index into the DB entry table) an dbentry_cnt is 1-based, the
274 	 * number of available slots.
275 	 */
276 	if (logp->dbentry_cnt <= ndx) {
277 		if ((ret = __os_realloc(&logp->dbentry,
278 		    (ndx + DB_GROW_SIZE) * sizeof(DB_ENTRY))) != 0)
279 			goto err;
280 
281 		/* Initialize the new entries. */
282 		for (i = logp->dbentry_cnt; i < ndx + DB_GROW_SIZE; i++) {
283 			logp->dbentry[i].dbp = NULL;
284 			logp->dbentry[i].deleted = 0;
285 			logp->dbentry[i].name = NULL;
286 		}
287 
288 		logp->dbentry_cnt = i;
289 	}
290 
291 	/* Make space for the name and copy it in. */
292 	if (name != NULL) {
293 		if ((ret = __os_malloc(strlen(name) + 1,
294 		    NULL, &logp->dbentry[ndx].name)) != 0)
295 			goto err;
296 		strcpy(logp->dbentry[ndx].name, name);
297 	}
298 
299 	if (logp->dbentry[ndx].deleted == 0 && logp->dbentry[ndx].dbp == NULL) {
300 		logp->dbentry[ndx].dbp = dbp;
301 		logp->dbentry[ndx].refcount = 1;
302 		logp->dbentry[ndx].deleted = dbp == NULL;
303 	} else
304 		logp->dbentry[ndx].refcount++;
305 
306 
307 err:	UNLOCK_LOGTHREAD(logp);
308 	return (ret);
309 }
310 
311 
312 /*
313  * __db_fileid_to_db --
314  *	Return the DB corresponding to the specified fileid.
315  *
316  * PUBLIC: int __db_fileid_to_db __P((DB_LOG *, DB **, u_int32_t));
317  */
318 int
319 __db_fileid_to_db(logp, dbpp, ndx)
320 	DB_LOG *logp;
321 	DB **dbpp;
322 	u_int32_t ndx;
323 {
324 	int ret;
325 	char *name;
326 	FNAME *fname;
327 
328 	ret = 0;
329 	LOCK_LOGTHREAD(logp);
330 
331 	/*
332 	 * Under XA, a process different than the one issuing DB
333 	 * operations may abort a transaction.  In this case,
334 	 * recovery routines are run by a process that does not
335 	 * necessarily have the file open.  In this case, we must
336 	 * open the file explicitly.
337 	 */
338 	if (ndx >= logp->dbentry_cnt ||
339 	    (!logp->dbentry[ndx].deleted && logp->dbentry[ndx].dbp == NULL)) {
340 		if (__log_lid_to_fname(logp, ndx, &fname) != 0) {
341 			/* Couldn't find entry; this is a fatal error. */
342 			ret = EINVAL;
343 			goto err;
344 		}
345 		name = R_ADDR(logp, fname->name_off);
346 		/*
347 		 * __log_do_open is called without protection of the
348 		 * log thread lock.
349 		 */
350 		UNLOCK_LOGTHREAD(logp);
351 		/*
352 		 * At this point, we are not holding the thread lock, so
353 		 * exit directly instead of going through the exit code
354 		 * at the bottom.  If the __log_do_open succeeded, then
355 		 * we don't need to do any of the remaining error checking
356 		 * at the end of this routine.
357 		 */
358 		if ((ret = __log_do_open(logp,
359 		    fname->ufid, name, fname->s_type, ndx)) != 0)
360 			return (ret);
361 		*dbpp = logp->dbentry[ndx].dbp;
362 		return (0);
363 	}
364 
365 	/*
366 	 * Return DB_DELETED if the file has been deleted
367 	 * (it's not an error).
368 	 */
369 	if (logp->dbentry[ndx].deleted) {
370 		ret = DB_DELETED;
371 		goto err;
372 	}
373 
374 	/*
375 	 * Otherwise return 0, but if we don't have a corresponding DB,
376 	 * it's an error.
377 	 */
378 	if ((*dbpp = logp->dbentry[ndx].dbp) == NULL)
379 		ret = ENOENT;
380 
381 err:	UNLOCK_LOGTHREAD(logp);
382 	return (ret);
383 }
384 
385 /*
386  * Close files that were opened by the recovery daemon.
387  *
388  * PUBLIC: void __log_close_files __P((DB_LOG *));
389  */
390 void
391 __log_close_files(logp)
392 	DB_LOG *logp;
393 {
394 	u_int32_t i;
395 
396 	LOCK_LOGTHREAD(logp);
397 	for (i = 0; i < logp->dbentry_cnt; i++)
398 		if (logp->dbentry[i].dbp) {
399 			logp->dbentry[i].dbp->close(logp->dbentry[i].dbp, 0);
400 			logp->dbentry[i].dbp = NULL;
401 			logp->dbentry[i].deleted = 0;
402 		}
403 	F_CLR(logp, DBC_RECOVER);
404 	UNLOCK_LOGTHREAD(logp);
405 }
406 
407 /*
408  * PUBLIC: void __log_rem_logid __P((DB_LOG *, u_int32_t));
409  */
410 void
411 __log_rem_logid(logp, ndx)
412 	DB_LOG *logp;
413 	u_int32_t ndx;
414 {
415 	LOCK_LOGTHREAD(logp);
416 	if (--logp->dbentry[ndx].refcount == 0) {
417 		logp->dbentry[ndx].dbp = NULL;
418 		logp->dbentry[ndx].deleted = 0;
419 	}
420 	UNLOCK_LOGTHREAD(logp);
421 }
422 
423 /*
424  * __log_lid_to_fname --
425  * 	Traverse the shared-memory region looking for the entry that
426  * matches the passed log fileid.  Returns 0 on success; -1 on error.
427  */
428 static int
429 __log_lid_to_fname(dblp, lid, fnamep)
430 	DB_LOG *dblp;
431 	u_int32_t lid;
432 	FNAME **fnamep;
433 {
434 	FNAME *fnp;
435 
436 	for (fnp = SH_TAILQ_FIRST(&dblp->lp->fq, __fname);
437 	    fnp != NULL; fnp = SH_TAILQ_NEXT(fnp, q, __fname)) {
438 		if (fnp->ref == 0)	/* Entry not in use. */
439 			continue;
440 		if (fnp->id == lid) {
441 			*fnamep = fnp;
442 			return (0);
443 		}
444 	}
445 	return (-1);
446 }
447