/*- * See the file LICENSE for redistribution information. * * Copyright (c) 1996-2002 * Sleepycat Software. All rights reserved. */ #include "db_config.h" #ifndef lint static const char copyright[] = "Copyright (c) 1996-2002\nSleepycat Software Inc. All rights reserved.\n"; static const char revid[] = "$Id: env_recover.c,v 1.1.1.1 2003/02/15 04:56:05 zarzycki Exp $"; #endif #ifndef NO_SYSTEM_INCLUDES #include #if TIME_WITH_SYS_TIME #include #include #else #if HAVE_SYS_TIME_H #include #else #include #endif #endif #include #endif #include "db_int.h" #include "dbinc/db_page.h" #include "dbinc/db_shash.h" #include "dbinc/lock.h" #include "dbinc/log.h" #include "dbinc/rep.h" #include "dbinc/txn.h" #include "dbinc/db_am.h" static int __log_backup __P((DB_ENV *, DB_LOGC *, DB_LSN *, DB_LSN *)); static int __log_earliest __P((DB_ENV *, DB_LOGC *, int32_t *, DB_LSN *)); static double __lsn_diff __P((DB_LSN *, DB_LSN *, DB_LSN *, u_int32_t, int)); /* * __db_apprec -- * Perform recovery. If max_lsn is non-NULL, then we are trying * to synchronize this system up with another system that has a max * LSN of max_lsn, so we need to roll back sufficiently far for that * to work. See __log_backup for details. * * PUBLIC: int __db_apprec __P((DB_ENV *, DB_LSN *, u_int32_t)); */ int __db_apprec(dbenv, max_lsn, flags) DB_ENV *dbenv; DB_LSN *max_lsn; u_int32_t flags; { DBT data; DB_LOGC *logc; DB_LSN ckp_lsn, first_lsn, last_lsn, lowlsn, lsn, stop_lsn; DB_TXNREGION *region; __txn_ckp_args *ckp_args; time_t now, tlow; int32_t log_size, low; double nfiles; int have_rec, is_thread, progress, ret, t_ret; int (**dtab) __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *)); size_t dtabsize; u_int32_t hi_txn, lockid, txnid; char *p, *pass, t1[60], t2[60]; void *txninfo; COMPQUIET(nfiles, (double)0); logc = NULL; ckp_args = NULL; dtab = NULL; hi_txn = TXN_MAXIMUM; lockid = DB_LOCK_INVALIDID; txninfo = NULL; pass = "initial"; /* * XXX * Get the log size. No locking required because we're single-threaded * during recovery. */ log_size = ((LOG *)(((DB_LOG *)dbenv->lg_handle)->reginfo.primary))->log_size; /* * Save the state of the thread flag -- we don't need it on at the * moment because we're single-threaded until recovery is complete. */ is_thread = F_ISSET(dbenv, DB_ENV_THREAD) ? 1 : 0; F_CLR(dbenv, DB_ENV_THREAD); /* Set in-recovery flags. */ F_SET((DB_LOG *)dbenv->lg_handle, DBLOG_RECOVER); region = ((DB_TXNMGR *)dbenv->tx_handle)->reginfo.primary; F_SET(region, TXN_IN_RECOVERY); /* Allocate a cursor for the log. */ if ((ret = dbenv->log_cursor(dbenv, &logc, 0)) != 0) goto err; /* * If the user is specifying recovery to a particular point in time * or to a particular LSN, find the point to start recovery from. */ ZERO_LSN(lowlsn); if (max_lsn != NULL) { if ((ret = __log_backup(dbenv, logc, max_lsn, &lowlsn)) != 0) goto err; } else if (dbenv->tx_timestamp != 0) { if ((ret = __log_earliest(dbenv, logc, &low, &lowlsn)) != 0) goto err; if ((int32_t)dbenv->tx_timestamp < low) { (void)snprintf(t1, sizeof(t1), "%s", ctime(&dbenv->tx_timestamp)); if ((p = strchr(t1, '\n')) != NULL) *p = '\0'; tlow = (time_t)low; (void)snprintf(t2, sizeof(t2), "%s", ctime(&tlow)); if ((p = strchr(t2, '\n')) != NULL) *p = '\0'; __db_err(dbenv, "Invalid recovery timestamp %s; earliest time is %s", t1, t2); ret = EINVAL; goto err; } } /* * Recovery is done in three passes: * Pass #0: * We need to find the position from which we will open files. * We need to open files beginning with the earlier of the * most recent checkpoint LSN and a checkpoint LSN before the * recovery timestamp, if specified. We need to be before the * most recent checkpoint LSN because we are going to collect * information about which transactions were begun before we * start rolling forward. Those that were should never be undone * because queue cannot use LSNs to determine what operations can * safely be aborted and it cannot rollback operations in * transactions for which there may be records not processed * during recovery. We need to consider earlier points in time * in case we are recovering to a particular timestamp. * * Pass #1: * Read forward through the log from the position found in pass 0 * opening and closing files, and recording transactions for which * we've seen their first record (the transaction's prev_lsn is * 0,0). At the end of this pass, we know all transactions for * which we've seen begins and we have the "current" set of files * open. * * Pass #2: * Read backward through the log undoing any uncompleted TXNs. * There are four cases: * 1. If doing catastrophic recovery, we read to the * beginning of the log * 2. If we are doing normal reovery, then we have to roll * back to the most recent checkpoint LSN. * 3. If we are recovering to a point in time, then we have * to roll back to the checkpoint whose ckp_lsn is earlier * than the specified time. __log_earliest will figure * this out for us. * 4. If we are recovering back to a particular LSN, then * we have to roll back to the checkpoint whose ckp_lsn * is earlier than the max_lsn. __log_backup will figure * that out for us. * In case 2, "uncompleted TXNs" include all those who commited * after the user's specified timestamp. * * Pass #3: * Read forward through the log from the LSN found in pass #2, * redoing any committed TXNs (which commited after any user- * specified rollback point). During this pass, checkpoint * file information is ignored, and file openings and closings * are redone. * * ckp_lsn -- lsn of the last checkpoint or the first in the log. * first_lsn -- the lsn where the forward passes begin. * last_lsn -- the last lsn in the log, used for feedback * lowlsn -- the lsn we are rolling back to, if we are recovering * to a point in time. * lsn -- temporary use lsn. * stop_lsn -- the point at which forward roll should stop */ /* * Find out the last lsn, so that we can estimate how far along we * are in recovery. This will help us determine how much log there * is between the first LSN that we're going to be working with and * the last one. We assume that each of the three phases takes the * same amount of time (a false assumption) and then use the %-age * of the amount of log traversed to figure out how much of the * pass we've accomplished. * * If we can't find any log records, we're kind of done. */ #ifdef UMRW ZERO_LSN(last_lsn); #endif memset(&data, 0, sizeof(data)); if ((ret = logc->get(logc, &last_lsn, &data, DB_LAST)) != 0) { if (ret == DB_NOTFOUND) ret = 0; else __db_err(dbenv, "Last log record not found"); goto err; } do { /* txnid is after rectype, which is a u_int32. */ memcpy(&txnid, (u_int8_t *)data.data + sizeof(u_int32_t), sizeof(txnid)); if (txnid != 0) break; } while ((ret = logc->get(logc, &lsn, &data, DB_PREV)) == 0); /* * There are no transactions, so there is nothing to do unless * we're recovering to an LSN. If we are, we need to proceed since * we'll still need to do a vtruncate based on information we haven't * yet collected. */ if (ret == DB_NOTFOUND) { ret = 0; if (max_lsn == NULL) goto done; } if (ret != 0) goto err; hi_txn = txnid; /* * Pass #0 * Find the LSN from which we begin OPENFILES. * * If this is a catastrophic recovery, or if no checkpoint exists * in the log, the LSN is the first LSN in the log. * * Otherwise, it is the minimum of (1) the LSN in the last checkpoint * and (2) the LSN in the checkpoint before any specified recovery * timestamp or max_lsn. */ /* * Get the first LSN in the log; it's an initial default * even if this is not a catastrophic recovery. */ if ((ret = logc->get(logc, &ckp_lsn, &data, DB_FIRST)) != 0) { if (ret == DB_NOTFOUND) ret = 0; else __db_err(dbenv, "First log record not found"); goto err; } first_lsn = ckp_lsn; have_rec = 1; if (!LF_ISSET(DB_RECOVER_FATAL)) { if ((ret = __txn_getckp(dbenv, &ckp_lsn)) == 0 && (ret = logc->get(logc, &ckp_lsn, &data, DB_SET)) == 0) { /* We have a recent checkpoint. This is LSN (1). */ if ((ret = __txn_ckp_read(dbenv, data.data, &ckp_args)) != 0) { __db_err(dbenv, "Invalid checkpoint record at [%ld][%ld]", (u_long)ckp_lsn.file, (u_long)ckp_lsn.offset); goto err; } first_lsn = ckp_args->ckp_lsn; have_rec = 0; } /* * If LSN (2) exists, use it if it's before LSN (1). * (If LSN (1) doesn't exist, first_lsn is the * beginning of the log, so will "win" this check.) * * XXX * In the recovery-to-a-timestamp case, lowlsn is chosen by * __log_earliest, and is the checkpoint LSN of the * *earliest* checkpoint in the unreclaimed log. I * (krinsky) believe that we could optimize this by looking * instead for the LSN of the *latest* checkpoint before * the timestamp of interest, but I'm not sure that this * is worth doing right now. (We have to look for lowlsn * and low anyway, to make sure the requested timestamp is * somewhere in the logs we have, and all that's required * is that we pick *some* checkpoint after the beginning of * the logs and before the timestamp. */ if ((dbenv->tx_timestamp != 0 || max_lsn != NULL) && log_compare(&lowlsn, &first_lsn) < 0) { DB_ASSERT(have_rec == 0); first_lsn = lowlsn; } } /* Get the record at first_lsn if we don't have it already. */ if (!have_rec && (ret = logc->get(logc, &first_lsn, &data, DB_SET)) != 0) { __db_err(dbenv, "Checkpoint LSN record [%ld][%ld] not found", (u_long)first_lsn.file, (u_long)first_lsn.offset); goto err; } if (dbenv->db_feedback != NULL) { if (last_lsn.file == first_lsn.file) nfiles = (double) (last_lsn.offset - first_lsn.offset) / log_size; else nfiles = (double)(last_lsn.file - first_lsn.file) + (double)(log_size - first_lsn.offset + last_lsn.offset) / log_size; /* We are going to divide by nfiles; make sure it isn't 0. */ if (nfiles == 0) nfiles = (double)0.001; } /* Find a low txnid. */ ret = 0; do { /* txnid is after rectype, which is a u_int32. */ memcpy(&txnid, (u_int8_t *)data.data + sizeof(u_int32_t), sizeof(txnid)); if (txnid != 0) break; } while ((ret = logc->get(logc, &lsn, &data, DB_NEXT)) == 0); /* * There are no transactions and we're not recovering to an LSN (see * above), so there is nothing to do. */ if (ret == DB_NOTFOUND) { ret = 0; if (max_lsn == NULL) goto done; } /* Reset to the first lsn. */ if (ret != 0 || (ret = logc->get(logc, &first_lsn, &data, DB_SET)) != 0) goto err; /* Initialize the transaction list. */ if ((ret = __db_txnlist_init(dbenv, txnid, hi_txn, max_lsn, &txninfo)) != 0) goto err; /* * Pass #1 * Run forward through the log starting at the first relevant lsn. */ if ((ret = __env_openfiles(dbenv, logc, txninfo, &data, &first_lsn, &last_lsn, nfiles, 1)) != 0) goto err; /* * Pass #2. * * We used first_lsn to tell us how far back we need to recover, * use it here. */ if (FLD_ISSET(dbenv->verbose, DB_VERB_RECOVERY)) __db_err(dbenv, "Recovery starting from [%lu][%lu]", (u_long)first_lsn.file, (u_long)first_lsn.offset); /* * If we are doing client recovery, then we need to allocate * the page-info lock table. */ if (max_lsn != NULL) { if ((ret = __rep_lockpgno_init(dbenv, &dtab, &dtabsize)) != 0) goto err; if ((ret = dbenv->lock_id(dbenv, &lockid)) != 0) goto err; } pass = "backward"; for (ret = logc->get(logc, &lsn, &data, DB_LAST); ret == 0 && log_compare(&lsn, &first_lsn) >= 0; ret = logc->get(logc, &lsn, &data, DB_PREV)) { if (dbenv->db_feedback != NULL) { progress = 34 + (int)(33 * (__lsn_diff(&first_lsn, &last_lsn, &lsn, log_size, 0) / nfiles)); dbenv->db_feedback(dbenv, DB_RECOVER, progress); } if (max_lsn != NULL && (ret = __rep_lockpages(dbenv, dtab, dtabsize, &lsn, NULL, NULL, lockid)) != 0) continue; ret = __db_dispatch(dbenv, dbenv->recover_dtab, dbenv->recover_dtab_size, &data, &lsn, DB_TXN_BACKWARD_ROLL, txninfo); if (ret != 0) { if (ret != DB_TXN_CKP) goto msgerr; else ret = 0; } } if (ret != 0 && ret != DB_NOTFOUND) goto err; /* * Pass #3. If we are recovering to a timestamp or to an LSN, * we need to make sure that we don't roll-forward beyond that * point because there may be non-transactional operations (e.g., * closes that would fail). The last_lsn variable is used for * feedback calculations, but use it to set an initial stopping * point for the forward pass, and then reset appropriately to * derive a real stop_lsn that tells how far the forward pass * should go. */ pass = "forward"; stop_lsn = last_lsn; if (max_lsn != NULL || dbenv->tx_timestamp != 0) stop_lsn = ((DB_TXNHEAD *)txninfo)->maxlsn; for (ret = logc->get(logc, &lsn, &data, DB_NEXT); ret == 0; ret = logc->get(logc, &lsn, &data, DB_NEXT)) { /* * If we are recovering to a timestamp or an LSN, * we need to make sure that we don't try to roll * forward beyond the soon-to-be end of log. */ if (log_compare(&lsn, &stop_lsn) > 0) break; if (dbenv->db_feedback != NULL) { progress = 67 + (int)(33 * (__lsn_diff(&first_lsn, &last_lsn, &lsn, log_size, 1) / nfiles)); dbenv->db_feedback(dbenv, DB_RECOVER, progress); } ret = __db_dispatch(dbenv, dbenv->recover_dtab, dbenv->recover_dtab_size, &data, &lsn, DB_TXN_FORWARD_ROLL, txninfo); if (ret != 0) { if (ret != DB_TXN_CKP) goto msgerr; else ret = 0; } } if (ret != 0 && ret != DB_NOTFOUND) goto err; /* * Process any pages that were on the limbo list and move them to * the free list. Do this before checkpointing the database. */ if ((ret = __db_do_the_limbo(dbenv, NULL, NULL, txninfo)) != 0) goto err; if (max_lsn == NULL) region->last_txnid = ((DB_TXNHEAD *)txninfo)->maxid; /* Take a checkpoint here to force any dirty data pages to disk. */ if (dbenv->tx_timestamp != 0) { region->last_ckp = ((DB_TXNHEAD *)txninfo)->ckplsn; __log_vtruncate(dbenv, &((DB_TXNHEAD *)txninfo)->maxlsn, &((DB_TXNHEAD *)txninfo)->ckplsn); } if ((ret = dbenv->txn_checkpoint(dbenv, 0, 0, DB_FORCE)) != 0) goto err; /* Close all the db files that are open. */ if ((ret = __dbreg_close_files(dbenv)) != 0) goto err; if (max_lsn != NULL) { region->last_ckp = ((DB_TXNHEAD *)txninfo)->ckplsn; /* We are going to truncate, so we'd best close the cursor. */ if (logc != NULL && (ret = logc->close(logc, 0)) != 0) goto err; __log_vtruncate(dbenv, max_lsn, &((DB_TXNHEAD *)txninfo)->ckplsn); /* * Now we need to open files that should be open in order for * client processing to continue. However, since we've * truncated the log, we need to recompute from where the * openfiles pass should begin. */ if ((ret = dbenv->log_cursor(dbenv, &logc, 0)) != 0) goto err; if ((ret = logc->get(logc, &first_lsn, &data, DB_FIRST)) != 0) { if (ret == DB_NOTFOUND) ret = 0; else __db_err(dbenv, "First log record not found"); goto err; } if ((ret = __txn_getckp(dbenv, &first_lsn)) == 0 && (ret = logc->get(logc, &first_lsn, &data, DB_SET)) == 0) { /* We have a recent checkpoint. This is LSN (1). */ if ((ret = __txn_ckp_read(dbenv, data.data, &ckp_args)) != 0) { __db_err(dbenv, "Invalid checkpoint record at [%ld][%ld]", (u_long)first_lsn.file, (u_long)first_lsn.offset); goto err; } first_lsn = ckp_args->ckp_lsn; } if ((ret = logc->get(logc, &first_lsn, &data, DB_SET)) != 0) goto err; if ((ret = __env_openfiles(dbenv, logc, txninfo, &data, &first_lsn, NULL, nfiles, 1)) != 0) goto err; } else if (region->stat.st_nrestores == 0) /* * If there are no prepared transactions that need resolution, * we need to reset the transaction ID space and log this fact. */ if ((ret = __txn_reset(dbenv)) != 0) goto err; if (FLD_ISSET(dbenv->verbose, DB_VERB_RECOVERY)) { (void)time(&now); __db_err(dbenv, "Recovery complete at %.24s", ctime(&now)); __db_err(dbenv, "%s %lx %s [%lu][%lu]", "Maximum transaction ID", ((DB_TXNHEAD *)txninfo)->maxid, "Recovery checkpoint", (u_long)region->last_ckp.file, (u_long)region->last_ckp.offset); } if (0) { msgerr: __db_err(dbenv, "Recovery function for LSN %lu %lu failed on %s pass", (u_long)lsn.file, (u_long)lsn.offset, pass); } done: err: if (lockid != DB_LOCK_INVALIDID) { if ((t_ret = __rep_unlockpages(dbenv, lockid)) != 0 && ret == 0) ret = t_ret; if ((t_ret = dbenv->lock_id_free(dbenv, lockid)) != 0 && ret == 0) ret = t_ret; } if (logc != NULL && (t_ret = logc->close(logc, 0)) != 0 && ret == 0) ret = t_ret; if (txninfo != NULL) __db_txnlist_end(dbenv, txninfo); if (dtab != NULL) __os_free(dbenv, dtab); if (ckp_args != NULL) __os_free(dbenv, ckp_args); dbenv->tx_timestamp = 0; /* Restore the state of the thread flag, clear in-recovery flags. */ if (is_thread) F_SET(dbenv, DB_ENV_THREAD); F_CLR((DB_LOG *)dbenv->lg_handle, DBLOG_RECOVER); F_CLR(region, TXN_IN_RECOVERY); return (ret); } /* * Figure out how many logfiles we have processed. If we are moving * forward (is_forward != 0), then we're computing current - low. If * we are moving backward, we are computing high - current. max is * the number of bytes per logfile. */ static double __lsn_diff(low, high, current, max, is_forward) DB_LSN *low, *high, *current; u_int32_t max; int is_forward; { double nf; /* * There are three cases in each direction. If you are in the * same file, then all you need worry about is the difference in * offsets. If you are in different files, then either your offsets * put you either more or less than the integral difference in the * number of files -- we need to handle both of these. */ if (is_forward) { if (current->file == low->file) nf = (double)(current->offset - low->offset) / max; else if (current->offset < low->offset) nf = (double)(current->file - low->file - 1) + (double)(max - low->offset + current->offset) / max; else nf = (double)(current->file - low->file) + (double)(current->offset - low->offset) / max; } else { if (current->file == high->file) nf = (double)(high->offset - current->offset) / max; else if (current->offset > high->offset) nf = (double)(high->file - current->file - 1) + (double) (max - current->offset + high->offset) / max; else nf = (double)(high->file - current->file) + (double)(high->offset - current->offset) / max; } return (nf); } /* * __log_backup -- * * This is used to find the earliest log record to process when a client * is trying to sync up with a master whose max LSN is less than this * client's max lsn; we want to roll back everything after that * * Find the latest checkpoint whose ckp_lsn is less than the max lsn. */ static int __log_backup(dbenv, logc, max_lsn, start_lsn) DB_ENV *dbenv; DB_LOGC *logc; DB_LSN *max_lsn, *start_lsn; { DB_LSN lsn; DBT data; __txn_ckp_args *ckp_args; int ret; memset(&data, 0, sizeof(data)); ckp_args = NULL; /* * Follow checkpoints through the log until we find one with * a ckp_lsn less than max_lsn. */ if ((ret = __txn_getckp(dbenv, &lsn)) != 0) goto err; while ((ret = logc->get(logc, &lsn, &data, DB_SET)) == 0) { if ((ret = __txn_ckp_read(dbenv, data.data, &ckp_args)) != 0) return (ret); if (log_compare(&ckp_args->ckp_lsn, max_lsn) <= 0) { *start_lsn = ckp_args->ckp_lsn; break; } lsn = ckp_args->prev_lsn; if (IS_ZERO_LSN(lsn)) break; __os_free(dbenv, ckp_args); } if (ckp_args != NULL) __os_free(dbenv, ckp_args); err: if (IS_ZERO_LSN(*start_lsn) && (ret == 0 || ret == DB_NOTFOUND)) ret = logc->get(logc, start_lsn, &data, DB_FIRST); return (ret); } /* * __log_earliest -- * * Return the earliest recovery point for the log files present. The * earliest recovery time is the time stamp of the first checkpoint record * whose checkpoint LSN is greater than the first LSN we process. */ static int __log_earliest(dbenv, logc, lowtime, lowlsn) DB_ENV *dbenv; DB_LOGC *logc; int32_t *lowtime; DB_LSN *lowlsn; { DB_LSN first_lsn, lsn; DBT data; __txn_ckp_args *ckpargs; u_int32_t rectype; int cmp, ret; memset(&data, 0, sizeof(data)); /* * Read forward through the log looking for the first checkpoint * record whose ckp_lsn is greater than first_lsn. */ for (ret = logc->get(logc, &first_lsn, &data, DB_FIRST); ret == 0; ret = logc->get(logc, &lsn, &data, DB_NEXT)) { memcpy(&rectype, data.data, sizeof(rectype)); if (rectype != DB___txn_ckp) continue; if ((ret = __txn_ckp_read(dbenv, data.data, &ckpargs)) == 0) { cmp = log_compare(&ckpargs->ckp_lsn, &first_lsn); *lowlsn = ckpargs->ckp_lsn; *lowtime = ckpargs->timestamp; __os_free(dbenv, ckpargs); if (cmp >= 0) break; } } return (ret); } /* * __env_openfiles -- * Perform the pass of recovery that opens files. This is used * both during regular recovery and an initial call to txn_recover (since * we need files open in order to abort prepared, but not yet committed * transactions). * * See the comments in db_apprec for a detailed description of the * various recovery passes. * * If we are not doing feedback processing (i.e., we are doing txn_recover * processing and in_recovery is zero), then last_lsn can be NULL. * * PUBLIC: int __env_openfiles __P((DB_ENV *, DB_LOGC *, * PUBLIC: void *, DBT *, DB_LSN *, DB_LSN *, double, int)); */ int __env_openfiles(dbenv, logc, txninfo, data, open_lsn, last_lsn, nfiles, in_recovery) DB_ENV *dbenv; DB_LOGC *logc; void *txninfo; DBT *data; DB_LSN *open_lsn, *last_lsn; int in_recovery; double nfiles; { DB_LSN lsn; u_int32_t log_size; int progress, ret; /* * XXX * Get the log size. No locking required because we're single-threaded * during recovery. */ log_size = ((LOG *)(((DB_LOG *)dbenv->lg_handle)->reginfo.primary))->log_size; lsn = *open_lsn; for (;;) { if (in_recovery && dbenv->db_feedback != NULL) { DB_ASSERT(last_lsn != NULL); progress = (int)(33 * (__lsn_diff(open_lsn, last_lsn, &lsn, log_size, 1) / nfiles)); dbenv->db_feedback(dbenv, DB_RECOVER, progress); } ret = __db_dispatch(dbenv, dbenv->recover_dtab, dbenv->recover_dtab_size, data, &lsn, in_recovery ? DB_TXN_OPENFILES : DB_TXN_POPENFILES, txninfo); if (ret != 0 && ret != DB_TXN_CKP) { __db_err(dbenv, "Recovery function for LSN %lu %lu failed", (u_long)lsn.file, (u_long)lsn.offset); break; } if ((ret = logc->get(logc, &lsn, data, DB_NEXT)) != 0) { if (ret == DB_NOTFOUND) ret = 0; break; } } return (ret); }