db

log_rec.c

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00001 /*-
00002  * See the file LICENSE for redistribution information.
00003  *
00004  * Copyright (c) 1996, 1997, 1998, 1999, 2000
00005  * Sleepycat Software. All rights reserved.
00006  */
00007 /*
00008  * Copyright (c) 1995, 1996
00009  * The President and Fellows of Harvard University. All rights reserved.
00010  *
00011  * Redistribution and use in source and binary forms, with or without
00012  * modification, are permitted provided that the following conditions
00013  * are met:
00014  * 1. Redistributions of source code must retain the above copyright
00015  * notice, this list of conditions and the following disclaimer.
00016  * 2. Redistributions in binary form must reproduce the above copyright
00017  * notice, this list of conditions and the following disclaimer in the
00018  * documentation and/or other materials provided with the distribution.
00019  * 3. Neither the name of the University nor the names of its contributors
00020  * may be used to endorse or promote products derived from this software
00021  * without specific prior written permission.
00022  *
00023  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
00024  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00025  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00026  * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
00027  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00028  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
00029  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
00030  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00031  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
00032  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00033  * SUCH DAMAGE.
00034  */
00035 
00036 #include "config.h"
00037 
00038 #ifndef lint
00039 static const char revid[] = "$Id: log__rec_8c-source.html,v 1.1 2008年06月08日 10:20:28 sebdiaz Exp $";
00040 #endif /* not lint */
00041 
00042 #ifndef NO_SYSTEM_INCLUDES
00043 #include <sys/types.h>
00044 
00045 #include <errno.h>
00046 #include <string.h>
00047 #endif
00048 
00049 #include "db_int.h"
00050 #include "db_page.h"
00051 #include "db_ext.h"
00052 #include "log.h"
00053 
00054 static int __log_do_open __P((DB_ENV *, DB_LOG *,
00055 u_int8_t *, char *, DBTYPE, int32_t, db_pgno_t));
00056 static int __log_lid_to_fname __P((DB_LOG *, int32_t, FNAME **));
00057 static int __log_open_file __P((DB_ENV *, DB_LOG *, __log_register_args *));
00058 
00059 /*
00060  * PUBLIC: int CDB___log_register_recover
00061  * PUBLIC: __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
00062  */
00063 int
00064 CDB___log_register_recover(dbenv, dbtp, lsnp, op, info)
00065 DB_ENV *dbenv;
00066 DBT *dbtp;
00067 DB_LSN *lsnp;
00068 db_recops op;
00069 void *info;
00070 {
00071 DB_ENTRY *dbe;
00072 DB_LOG *logp;
00073 DB *dbp;
00074 __log_register_args *argp;
00075 int do_rem, ret, t_ret;
00076 
00077 logp = dbenv->lg_handle;
00078 dbp = NULL;
00079 
00080 #ifdef DEBUG_RECOVER
00081 CDB___log_register_print(logp, dbtp, lsnp, op, info);
00082 #endif
00083 COMPQUIET(lsnp, NULL);
00084 
00085 if ((ret = CDB___log_register_read(dbenv, dbtp->data, &argp)) != 0)
00086 goto out;
00087 
00088 if ((argp->opcode == LOG_OPEN &&
00089 (DB_REDO(op) || op == DB_TXN_OPENFILES)) ||
00090 (argp->opcode == LOG_CLOSE && DB_UNDO(op))) {
00091 /*
00092  * If we are redoing an open or undoing a close, then we need
00093  * to open a file. We must open the file even if
00094  * the meta page is not yet written as we may be creating it.
00095  */
00096 if (op == DB_TXN_OPENFILES)
00097 F_SET(logp, DBLOG_FORCE_OPEN);
00098 ret = __log_open_file(dbenv, logp, argp);
00099 F_CLR(logp, DBLOG_FORCE_OPEN);
00100 if (ret == ENOENT || ret == EINVAL) {
00101 if (op == DB_TXN_OPENFILES && argp->name.size != 0 &&
00102 (ret = CDB___db_txnlist_delete(dbenv, info,
00103 argp->name.data, argp->fileid, 0)) != 0)
00104 goto out;
00105 ret = 0;
00106 }
00107 } else if (argp->opcode != LOG_CHECKPOINT) {
00108 /*
00109  * If we are undoing an open, then we need to close the file.
00110  *
00111  * If the file is deleted, then we can just ignore this close.
00112  * Otherwise, we should usually have a valid dbp we should
00113  * close or whose reference count should be decremented.
00114  * However, if we shut down without closing a file, we may, in
00115  * fact, not have the file open, and that's OK.
00116  */
00117 do_rem = 0;
00118 MUTEX_THREAD_LOCK(logp->mutexp);
00119 if (argp->fileid < logp->dbentry_cnt) {
00120 dbe = &logp->dbentry[argp->fileid];
00121 if (dbe->refcount == 1) {
00122 ret = CDB___db_txnlist_close(info,
00123 argp->fileid, dbe->count);
00124 if ((dbp = TAILQ_FIRST(&dbe->dblist)) != NULL)
00125 (void) CDB_log_unregister(dbenv, dbp);
00126 do_rem = 1;
00127 } else
00128 dbe->refcount--;
00129 }
00130 MUTEX_THREAD_UNLOCK(logp->mutexp);
00131 if (do_rem) {
00132 (void)CDB___log_rem_logid(logp, dbp, argp->fileid);
00133 /*
00134  * If remove or rename has closed the file, don't
00135  * sync.
00136  */
00137 if (dbp != NULL &&
00138 (t_ret = dbp->close(dbp,
00139 dbp->mpf == NULL ? DB_NOSYNC : 0)) != 0 && ret == 0)
00140 ret = t_ret;
00141 }
00142 } else if (DB_UNDO(op) || op == DB_TXN_OPENFILES) {
00143 /*
00144  * It's a checkpoint and we are rolling backward. It
00145  * is possible that the system was shut down and thus
00146  * ended with a stable checkpoint; this file was never
00147  * closed and has therefore not been reopened yet. If
00148  * so, we need to try to open it.
00149  */
00150 ret = __log_open_file(dbenv, logp, argp);
00151 if (ret == ENOENT || ret == EINVAL) {
00152 if (argp->name.size != 0 && (ret =
00153 CDB___db_txnlist_delete(dbenv, info,
00154 argp->name.data, argp->fileid, 0)) != 0)
00155 goto out;
00156 ret = 0;
00157 }
00158 }
00159 
00160 out: if (argp != NULL)
00161 CDB___os_free(argp, 0);
00162 return (ret);
00163 }
00164 
00165 /*
00166  * __log_open_file --
00167  * Called during CDB_log_register recovery. Make sure that we have an
00168  * entry in the dbentry table for this ndx. Returns 0 on success,
00169  * non-zero on error.
00170  */
00171 static int
00172 __log_open_file(dbenv, lp, argp)
00173 DB_ENV *dbenv;
00174 DB_LOG *lp;
00175 __log_register_args *argp;
00176 {
00177 DB_ENTRY *dbe;
00178 DB *dbp;
00179 
00180 /*
00181  * We never re-open temporary files. Temp files are only
00182  * useful during aborts in which case the dbp was entered
00183  * when the file was registered. During recovery, we treat
00184  * temp files as properly deleted files, allowing the open to
00185  * fail and not reporting any errors when recovery fails to
00186  * get a valid dbp from db_fileid_to_db.
00187  */
00188 if (argp->name.size == 0) {
00189 (void)CDB___log_add_logid(dbenv, lp, NULL, argp->fileid);
00190 return (ENOENT);
00191 }
00192 
00193 /*
00194  * Because of reference counting, we cannot automatically close files
00195  * during recovery, so when we're opening, we have to check that the
00196  * name we are opening is what we expect. If it's not, then we close
00197  * the old file and open the new one.
00198  */
00199 MUTEX_THREAD_LOCK(lp->mutexp);
00200 if (argp->fileid < lp->dbentry_cnt)
00201 dbe = &lp->dbentry[argp->fileid];
00202 else
00203 dbe = NULL;
00204 
00205 if (dbe != NULL) {
00206 dbe->deleted = 0;
00207 if ((dbp = TAILQ_FIRST(&dbe->dblist)) != NULL) {
00208 if (dbp->meta_pgno != argp->meta_pgno ||
00209 memcmp(dbp->fileid,
00210 argp->uid.data, DB_FILE_ID_LEN) != 0) {
00211 MUTEX_THREAD_UNLOCK(lp->mutexp);
00212 goto reopen;
00213 }
00214 if (!F_ISSET(lp, DBLOG_RECOVER))
00215 dbe->refcount++;
00216 MUTEX_THREAD_UNLOCK(lp->mutexp);
00217 return (0);
00218 }
00219 }
00220 
00221 MUTEX_THREAD_UNLOCK(lp->mutexp);
00222 if (0) {
00223 reopen: (void) CDB_log_unregister(dbp->dbenv, dbp);
00224 (void) CDB___log_rem_logid(lp, dbp, argp->fileid);
00225 dbp->close(dbp, 0);
00226 }
00227 
00228 return (__log_do_open(dbenv, lp,
00229 argp->uid.data, argp->name.data,
00230 argp->ftype, argp->fileid, argp->meta_pgno));
00231 }
00232 
00233 /*
00234  * log_reopen_file -- close and reopen a db file.
00235  * Must be called when a metadata page changes.
00236  *
00237  * PUBLIC: int CDB___log_reopen_file __P((DB_ENV *,
00238  * PUBLIC: char *, int32_t, u_int8_t *, db_pgno_t));
00239  *
00240  */
00241 int
00242 CDB___log_reopen_file(dbenv, name, ndx, fileid, meta_pgno)
00243 DB_ENV *dbenv;
00244 char *name;
00245 int32_t ndx;
00246 u_int8_t *fileid;
00247 db_pgno_t meta_pgno;
00248 {
00249 DB *dbp;
00250 DB_LOG *logp;
00251 DBTYPE ftype;
00252 int ret;
00253 
00254 logp = dbenv->lg_handle;
00255 
00256 if ((ret = CDB___db_fileid_to_db(dbenv, &dbp, ndx, 0)) != 0)
00257 goto out;
00258 ftype = dbp->type;
00259 (void) CDB_log_unregister(dbenv, dbp);
00260 (void) CDB___log_rem_logid(logp, dbp, ndx);
00261 (void) dbp->close(dbp, 0);
00262 
00263 ret = __log_do_open(dbenv, logp, fileid, name, ftype, ndx, meta_pgno);
00264 
00265 out: return (ret);
00266 }
00267 
00268 /*
00269  * __log_do_open --
00270  * Open files referenced in the log. This is the part of the open that
00271  * is not protected by the thread mutex.
00272  */
00273 static int
00274 __log_do_open(dbenv, lp, uid, name, ftype, ndx, meta_pgno)
00275 DB_ENV *dbenv;
00276 DB_LOG *lp;
00277 u_int8_t *uid;
00278 char *name;
00279 DBTYPE ftype;
00280 int32_t ndx;
00281 db_pgno_t meta_pgno;
00282 {
00283 DB *dbp;
00284 int ret;
00285 u_int8_t zeroid[DB_FILE_ID_LEN];
00286 
00287 if ((ret = CDB_db_create(&dbp, lp->dbenv, 0)) != 0)
00288 return (ret);
00289 
00290 dbp->log_fileid = ndx;
00291 
00292 /*
00293  * This is needed to signal to the locking routines called while
00294  * opening databases that we are potentially undoing a transaction
00295  * from an XA process. Since the XA process does not share
00296  * locks with the aborting transaction this prevents us from
00297  * deadlocking during the open during rollback.
00298  * Because this routine is called either during recovery or during an
00299  * XA_ABORT, we can safely set DB_AM_RECOVER in the dbp since it
00300  * will not be shared with other threads.
00301  */
00302 F_SET(dbp, DB_AM_RECOVER);
00303 if (meta_pgno != PGNO_BASE_MD)
00304 memcpy(dbp->fileid, uid, DB_FILE_ID_LEN);
00305 dbp->type = ftype;
00306 if ((ret = CDB___db_dbopen(dbp, name, 0, 0600, meta_pgno)) == 0) {
00307 /*
00308  * Verify that we are opening the same file that we were
00309  * referring to when we wrote this log record.
00310  */
00311 if (memcmp(uid, dbp->fileid, DB_FILE_ID_LEN) != 0) {
00312 memset(zeroid, 0, DB_FILE_ID_LEN);
00313 if (memcmp(dbp->fileid, zeroid, DB_FILE_ID_LEN) != 0)
00314 goto not_right;
00315 memcpy(dbp->fileid, uid, DB_FILE_ID_LEN);
00316 }
00317 if (IS_RECOVERING(dbenv)) {
00318 (void)CDB_log_register(dbp->dbenv, dbp, name);
00319 (void)CDB___log_add_logid(dbenv, lp, dbp, ndx);
00320 }
00321 return (0);
00322 }
00323 
00324 not_right:
00325 (void)dbp->close(dbp, 0);
00326 (void)CDB___log_add_logid(dbenv, lp, NULL, ndx);
00327 
00328 return (ENOENT);
00329 }
00330 
00331 /*
00332  * CDB___log_add_logid --
00333  * Adds a DB entry to the log's DB entry table.
00334  *
00335  * PUBLIC: int CDB___log_add_logid __P((DB_ENV *, DB_LOG *, DB *, int32_t));
00336  */
00337 int
00338 CDB___log_add_logid(dbenv, logp, dbp, ndx)
00339 DB_ENV *dbenv;
00340 DB_LOG *logp;
00341 DB *dbp;
00342 int32_t ndx;
00343 {
00344 int32_t i;
00345 int ret;
00346 
00347 ret = 0;
00348 
00349 MUTEX_THREAD_LOCK(logp->mutexp);
00350 
00351 /*
00352  * Check if we need to grow the table. Note, ndx is 0-based (the
00353  * index into the DB entry table) an dbentry_cnt is 1-based, the
00354  * number of available slots.
00355  */
00356 if (logp->dbentry_cnt <= ndx) {
00357 if ((ret = CDB___os_realloc(dbenv,
00358 (ndx + DB_GROW_SIZE) * sizeof(DB_ENTRY),
00359 NULL, &logp->dbentry)) != 0)
00360 goto err;
00361 
00362 /* Initialize the new entries. */
00363 for (i = logp->dbentry_cnt; i < ndx + DB_GROW_SIZE; i++) {
00364 logp->dbentry[i].count = 0;
00365 TAILQ_INIT(&logp->dbentry[i].dblist);
00366 logp->dbentry[i].deleted = 0;
00367 logp->dbentry[i].refcount = 0;
00368 }
00369 
00370 logp->dbentry_cnt = i;
00371 }
00372 
00373 if (logp->dbentry[ndx].deleted == 0 &&
00374 TAILQ_FIRST(&logp->dbentry[ndx].dblist) == NULL) {
00375 logp->dbentry[ndx].count = 0;
00376 if (dbp != NULL)
00377 TAILQ_INSERT_HEAD(&logp->dbentry[ndx].dblist,
00378 dbp, links);
00379 logp->dbentry[ndx].deleted = dbp == NULL;
00380 logp->dbentry[ndx].refcount = 1;
00381 } else if (!F_ISSET(logp, DBLOG_RECOVER)) {
00382 if (dbp != NULL)
00383 TAILQ_INSERT_HEAD(&logp->dbentry[ndx].dblist,
00384 dbp, links);
00385 logp->dbentry[ndx].refcount++;
00386 }
00387 
00388 err: MUTEX_THREAD_UNLOCK(logp->mutexp);
00389 return (ret);
00390 }
00391 
00392 /*
00393  * CDB___db_fileid_to_db --
00394  * Return the DB corresponding to the specified fileid.
00395  *
00396  * PUBLIC: int CDB___db_fileid_to_db __P((DB_ENV *, DB **, int32_t, int));
00397  */
00398 int
00399 CDB___db_fileid_to_db(dbenv, dbpp, ndx, inc)
00400 DB_ENV *dbenv;
00401 DB **dbpp;
00402 int32_t ndx;
00403 int inc;
00404 {
00405 DB_LOG *logp;
00406 DB *dbp;
00407 FNAME *fname;
00408 int ret;
00409 char *name;
00410 
00411 ret = 0;
00412 logp = dbenv->lg_handle;
00413 
00414 MUTEX_THREAD_LOCK(logp->mutexp);
00415 
00416 /*
00417  * Under XA, a process different than the one issuing DB operations
00418  * may abort a transaction. In this case, recovery routines are run
00419  * by a process that does not necessarily have the file open, so we
00420  * we must open the file explicitly.
00421  */
00422 if (ndx >= logp->dbentry_cnt ||
00423 (!logp->dbentry[ndx].deleted &&
00424 (dbp = TAILQ_FIRST(&logp->dbentry[ndx].dblist)) == NULL)) {
00425 if (F_ISSET(logp, DBLOG_RECOVER)) {
00426 ret = ENOENT;
00427 goto err;
00428 }
00429 if (__log_lid_to_fname(logp, ndx, &fname) != 0) {
00430 /* Couldn't find entry; this is a fatal error. */
00431 CDB___db_err(dbenv, "Missing log fileid entry");
00432 ret = EINVAL;
00433 goto err;
00434 }
00435 name = R_ADDR(&logp->reginfo, fname->name_off);
00436 
00437 /*
00438  * __log_do_open is called without protection of the
00439  * log thread lock.
00440  */
00441 MUTEX_THREAD_UNLOCK(logp->mutexp);
00442 
00443 /*
00444  * At this point, we are not holding the thread lock, so exit
00445  * directly instead of going through the exit code at the
00446  * bottom. If the __log_do_open succeeded, then we don't need
00447  * to do any of the remaining error checking at the end of this
00448  * routine.
00449  */
00450 if ((ret = __log_do_open(dbenv, logp,
00451 fname->ufid, name, fname->s_type,
00452 ndx, fname->meta_pgno)) != 0)
00453 return (ret);
00454 
00455 *dbpp = TAILQ_FIRST(&logp->dbentry[ndx].dblist);
00456 return (0);
00457 }
00458 
00459 /*
00460  * Return DB_DELETED if the file has been deleted (it's not an error).
00461  */
00462 if (logp->dbentry[ndx].deleted) {
00463 ret = DB_DELETED;
00464 if (inc)
00465 logp->dbentry[ndx].count++;
00466 goto err;
00467 }
00468 
00469 /*
00470  * Otherwise return 0, but if we don't have a corresponding DB, it's
00471  * an error.
00472  */
00473 if ((*dbpp = TAILQ_FIRST(&logp->dbentry[ndx].dblist)) == NULL)
00474 ret = ENOENT;
00475 
00476 err: MUTEX_THREAD_UNLOCK(logp->mutexp);
00477 return (ret);
00478 }
00479 
00480 /*
00481  * Close files that were opened by the recovery daemon.
00482  *
00483  * PUBLIC: void CDB___log_close_files __P((DB_ENV *));
00484  */
00485 void
00486 CDB___log_close_files(dbenv)
00487 DB_ENV *dbenv;
00488 {
00489 DB_ENTRY *dbe;
00490 DB_LOG *logp;
00491 DB *dbp;
00492 int32_t i;
00493 
00494 logp = dbenv->lg_handle;
00495 MUTEX_THREAD_LOCK(logp->mutexp);
00496 for (i = 0; i < logp->dbentry_cnt; i++) {
00497 dbe = &logp->dbentry[i];
00498 while ((dbp = TAILQ_FIRST(&dbe->dblist)) != NULL) {
00499 (void)CDB_log_unregister(dbenv, dbp);
00500 TAILQ_REMOVE(&dbe->dblist, dbp, links);
00501 (void)dbp->close(dbp, 0);
00502 }
00503 dbe->deleted = 0;
00504 dbe->refcount = 0;
00505 }
00506 MUTEX_THREAD_UNLOCK(logp->mutexp);
00507 }
00508 
00509 /*
00510  * CDB___log_rem_logid
00511  * Remove an entry from the log table. Find the appropriate DB and
00512  * unlink it from the linked list off the table. If the DB is NULL, treat
00513  * this as a simple refcount decrement.
00514  *
00515  * PUBLIC: void CDB___log_rem_logid __P((DB_LOG *, DB *, int32_t));
00516  */
00517 void
00518 CDB___log_rem_logid(logp, dbp, ndx)
00519 DB_LOG *logp;
00520 DB *dbp;
00521 int32_t ndx;
00522 {
00523 DB *xdbp;
00524 
00525 MUTEX_THREAD_LOCK(logp->mutexp);
00526 if (--logp->dbentry[ndx].refcount == 0) {
00527 TAILQ_INIT(&logp->dbentry[ndx].dblist);
00528 logp->dbentry[ndx].deleted = 0;
00529 } else if (dbp != NULL)
00530 for (xdbp = TAILQ_FIRST(&logp->dbentry[ndx].dblist);
00531 xdbp != NULL;
00532 xdbp = TAILQ_NEXT(xdbp, links))
00533 if (xdbp == dbp) {
00534 TAILQ_REMOVE(&logp->dbentry[ndx].dblist,
00535 xdbp, links);
00536 break;
00537 }
00538 
00539 MUTEX_THREAD_UNLOCK(logp->mutexp);
00540 }
00541 
00542 /*
00543  * __log_lid_to_fname --
00544  * Traverse the shared-memory region looking for the entry that
00545  * matches the passed log fileid. Returns 0 on success; -1 on error.
00546  */
00547 static int
00548 __log_lid_to_fname(dblp, lid, fnamep)
00549 DB_LOG *dblp;
00550 int32_t lid;
00551 FNAME **fnamep;
00552 {
00553 FNAME *fnp;
00554 LOG *lp;
00555 
00556 lp = dblp->reginfo.primary;
00557 
00558 for (fnp = SH_TAILQ_FIRST(&lp->fq, __fname);
00559 fnp != NULL; fnp = SH_TAILQ_NEXT(fnp, q, __fname)) {
00560 if (fnp->ref == 0) /* Entry not in use. */
00561 continue;
00562 if (fnp->id == lid) {
00563 *fnamep = fnp;
00564 return (0);
00565 }
00566 }
00567 return (-1);
00568 }

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