text: /*-
   * See the file LICENSE for redistribution information.
   *
   * Copyright (c) 1996, 2013 Oracle and/or its affiliates.  All rights reserved.
   */
  /*
   * Copyright (c) 1996
   *	The President and Fellows of Harvard University.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   * $Id$
   */
  
  #include "db_config.h"
  
  #include "db_int.h"
  #include "dbinc/db_page.h"
  #include "dbinc/lock.h"
  #include "dbinc/txn.h"
  #include "dbinc/db_am.h"
  
  /*
   * PUBLIC: int __txn_regop_recover
   * PUBLIC:    __P((ENV *, DBT *, DB_LSN *, db_recops, void *));
   *
   * These records are only ever written for commits.  Normally, we redo any
   * committed transaction, however if we are doing recovery to a timestamp, then
   * we may treat transactions that committed after the timestamp as aborted.
   */
  int
  __txn_regop_recover(env, dbtp, lsnp, op, info)
  	ENV *env;
  	DBT *dbtp;
  	DB_LSN *lsnp;
  	db_recops op;
  	void *info;
  {
  	__txn_regop_args *argp;
  	DB_TXNHEAD *headp;
  	int ret;
  	u_int32_t status;
  
  #ifdef DEBUG_RECOVER
  	(void)__txn_regop_print(env, dbtp, lsnp, op, info);
  #endif
  
  	if ((ret = __txn_regop_read(env, dbtp->data, &argp)) != 0)
  		return (ret);
  
  	headp = info;
  	/*
  	 * We are only ever called during FORWARD_ROLL or BACKWARD_ROLL.
  	 * We check for the former explicitly and the last two clauses
  	 * apply to the BACKWARD_ROLL case.
  	 */
  
  	if (op == DB_TXN_FORWARD_ROLL) {
  		/*
  		 * If this was a 2-phase-commit transaction, then it
  		 * might already have been removed from the list, and
  		 * that's OK.  Ignore the return code from remove.
  		 */
  		if ((ret = __db_txnlist_remove(env,
  		    info, argp->txnp->txnid)) != DB_NOTFOUND && ret != 0)
  			goto err;
  	} else if ((env->dbenv->tx_timestamp != 0 &&
  	    argp->timestamp > (int32_t)env->dbenv->tx_timestamp) ||
  	    (!IS_ZERO_LSN(headp->trunc_lsn) &&
  	    LOG_COMPARE(&headp->trunc_lsn, lsnp) < 0)) {
  		/*
  		 * We failed either the timestamp check or the trunc_lsn check,
  		 * so we treat this as an abort even if it was a commit record.
  		 */
  		if ((ret = __db_txnlist_update(env, info,
  		    argp->txnp->txnid, TXN_ABORT, NULL, &status, 1)) != 0)
  			goto err;
  		else if (status != TXN_IGNORE && status != TXN_OK)
  			goto err;
  	} else {
  		/* This is a normal commit; mark it appropriately. */
  		if ((ret = __db_txnlist_update(env,
  		    info, argp->txnp->txnid, argp->opcode, lsnp,
  		    &status, 0)) == DB_NOTFOUND) {
  			if ((ret = __db_txnlist_add(env,
  			    info, argp->txnp->txnid,
  			    argp->opcode == TXN_ABORT ?
  			    TXN_IGNORE : argp->opcode, lsnp)) != 0)
  				goto err;
  		} else if (ret != 0 ||
  		    (status != TXN_IGNORE && status != TXN_OK))
  			goto err;
  	}
  
  	if (ret == 0)
  		*lsnp = argp->prev_lsn;
  
  	if (0) {
  err:		__db_errx(env, DB_STR_A("4514",
  		    "txnid %lx commit record found, already on commit list",
  		    "%lx"), (u_long)argp->txnp->txnid);
  		ret = EINVAL;
  	}
  	__os_free(env, argp);
  
  	return (ret);
  }
  
  /*
   * PUBLIC: int __txn_prepare_recover
   * PUBLIC:    __P((ENV *, DBT *, DB_LSN *, db_recops, void *));
   *
   * These records are only ever written for prepares.
   */
  int
  __txn_prepare_recover(env, dbtp, lsnp, op, info)
  	ENV *env;
  	DBT *dbtp;
  	DB_LSN *lsnp;
  	db_recops op;
  	void *info;
  {
  	__txn_prepare_args *argp;
  	DBT *lock_dbt;
  	DB_TXNHEAD *headp;
  	DB_LOCKTAB *lt;
  	u_int32_t status;
  	int ret;
  
  #ifdef DEBUG_RECOVER
  	(void)__txn_prepare_print(env, dbtp, lsnp, op, info);
  #endif
  
  	if ((ret = __txn_prepare_read(env, dbtp->data, &argp)) != 0)
  		return (ret);
  
  	if (argp->opcode != TXN_PREPARE && argp->opcode != TXN_ABORT) {
  		ret = EINVAL;
  		goto err;
  	}
  	headp = info;
  
  	/*
  	 * The return value here is either a DB_NOTFOUND or it is
  	 * the transaction status from the list.  It is not a normal
  	 * error return, so we must make sure that in each of the
  	 * cases below, we overwrite the ret value so we return
  	 * appropriately.
  	 */
  	ret = __db_txnlist_find(env, info, argp->txnp->txnid, &status);
  
  	/*
  	 * If we are rolling forward, then an aborted prepare
  	 * indicates that this may be the last record we'll see for
  	 * this transaction ID, so we should remove it from the list.
  	 */
  
  	if (op == DB_TXN_FORWARD_ROLL) {
  		if ((ret = __db_txnlist_remove(env,
  		    info, argp->txnp->txnid)) != 0)
  			goto txn_err;
  	} else if (op == DB_TXN_BACKWARD_ROLL && status == TXN_PREPARE) {
  		/*
  		 * On the backward pass, we have four possibilities:
  		 * 1. The transaction is already committed, no-op.
  		 * 2. The transaction is already aborted, no-op.
  		 * 3. The prepare failed and was aborted, mark as abort.
  		 * 4. The transaction is neither committed nor aborted.
  		 *	 Treat this like a commit and roll forward so that
  		 *	 the transaction can be resurrected in the region.
  		 * We handle cases 3 and 4 here; cases 1 and 2
  		 * are the final clause below.
  		 */
  		if (argp->opcode == TXN_ABORT) {
  			if ((ret = __db_txnlist_update(env,
  			     info, argp->txnp->txnid,
  			     TXN_ABORT, NULL, &status, 0)) != 0 &&
  			     status != TXN_PREPARE)
  				goto txn_err;
  			ret = 0;
  		}
  		/*
  		 * This is prepared, but not yet committed transaction.  We
  		 * need to add it to the transaction list, so that it gets
  		 * rolled forward. We also have to add it to the region's
  		 * internal state so it can be properly aborted or committed
  		 * after recovery (see txn_recover).
  		 */
  		else if ((ret = __db_txnlist_remove(env,
  		    info, argp->txnp->txnid)) != 0) {
  txn_err:		__db_errx(env,
  			    DB_STR_A("4515",
  			    "transaction not in list %lx", "%lx"),
  			    (u_long)argp->txnp->txnid);
  			ret = DB_NOTFOUND;
  		} else if (IS_ZERO_LSN(headp->trunc_lsn) ||
  		    LOG_COMPARE(&headp->trunc_lsn, lsnp) >= 0) {
  			if ((ret = __db_txnlist_add(env,
  			   info, argp->txnp->txnid, TXN_COMMIT, lsnp)) == 0) {
  				/* Re-acquire the locks for this transaction. */
  				lock_dbt = &argp->locks;
  				if (LOCKING_ON(env)) {
  					lt = env->lk_handle;
  					if ((ret = __lock_getlocker(lt,
  						argp->txnp->txnid, 1,
  						&argp->txnp->locker)) != 0)
  						goto err;
  					if ((ret = __lock_get_list(env,
  					    argp->txnp->locker, 0,
  					    DB_LOCK_WRITE, lock_dbt)) != 0)
  						goto err;
  				}
  
  				ret = __txn_restore_txn(env, lsnp, argp);
  			}
  		}
  	} else
  		ret = 0;
  
  	if (ret == 0)
  		*lsnp = argp->prev_lsn;
  
  err:	__os_free(env, argp);
  
  	return (ret);
  }
  
  /*
   * PUBLIC: int __txn_ckp_recover
   * PUBLIC: __P((ENV *, DBT *, DB_LSN *, db_recops, void *));
   */
  int
  __txn_ckp_recover(env, dbtp, lsnp, op, info)
  	ENV *env;
  	DBT *dbtp;
  	DB_LSN *lsnp;
  	db_recops op;
  	void *info;
  {
  	__txn_ckp_args *argp;
  	int ret;
  
  #ifdef DEBUG_RECOVER
  	__txn_ckp_print(env, dbtp, lsnp, op, info);
  #endif
  	if ((ret = __txn_ckp_read(env, dbtp->data, &argp)) != 0)
  		return (ret);
  
  	if (op == DB_TXN_BACKWARD_ROLL)
  		__db_txnlist_ckp(env, info, lsnp);
  
  	*lsnp = argp->last_ckp;
  	__os_free(env, argp);
  	return (DB_TXN_CKP);
  }
  
  /*
   * __txn_child_recover
   *	Recover a commit record for a child transaction.
   *
   * PUBLIC: int __txn_child_recover
   * PUBLIC:    __P((ENV *, DBT *, DB_LSN *, db_recops, void *));
   */
  int
  __txn_child_recover(env, dbtp, lsnp, op, info)
  	ENV *env;
  	DBT *dbtp;
  	DB_LSN *lsnp;
  	db_recops op;
  	void *info;
  {
  	__txn_child_args *argp;
  	u_int32_t c_stat, p_stat, tmpstat;
  	int ret, t_ret;
  
  #ifdef DEBUG_RECOVER
  	(void)__txn_child_print(env, dbtp, lsnp, op, info);
  #endif
  	if ((ret = __txn_child_read(env, dbtp->data, &argp)) != 0)
  		return (ret);
  
  	/*
  	 * This is a record in a PARENT's log trail indicating that a
  	 * child committed.  If we are aborting, return the childs last
  	 * record's LSN.  If we are in recovery, then if the
  	 * parent is committing, we set ourselves up to commit, else
  	 * we do nothing.
  	 */
  	if (op == DB_TXN_ABORT) {
  		*lsnp = argp->c_lsn;
  		ret = __db_txnlist_lsnadd(env, info, &argp->prev_lsn);
  		goto out;
  	} else if (op == DB_TXN_BACKWARD_ROLL) {
  		/* Child might exist -- look for it. */
  		ret = __db_txnlist_find(env, info, argp->child, &c_stat);
  		t_ret =
  		    __db_txnlist_find(env, info, argp->txnp->txnid, &p_stat);
  		if (ret != 0 && ret != DB_NOTFOUND)
  			goto out;
  		if (t_ret != 0 && t_ret != DB_NOTFOUND) {
  			ret = t_ret;
  			goto out;
  		}
  		/*
  		 * If the parent is in state COMMIT or IGNORE, then we apply
  		 * that to the child, else we need to abort the child.
  		 */
  
  		if (ret == DB_NOTFOUND  ||
  		    c_stat == TXN_OK || c_stat == TXN_COMMIT) {
  			if (t_ret == DB_NOTFOUND ||
  			     (p_stat != TXN_COMMIT  && p_stat != TXN_IGNORE))
  				c_stat = TXN_ABORT;
  			else
  				c_stat = p_stat;
  
  			if (ret == DB_NOTFOUND)
  				ret = __db_txnlist_add(env,
  				     info, argp->child, c_stat, NULL);
  			else
  				ret = __db_txnlist_update(env, info,
  				     argp->child, c_stat, NULL, &tmpstat, 0);
  		} else if (c_stat == TXN_EXPECTED) {
  			/*
  			 * The open after this create succeeded.  If the
  			 * parent succeeded, we don't want to redo; if the
  			 * parent aborted, we do want to undo.
  			 */
  			switch (p_stat) {
  			case TXN_COMMIT:
  			case TXN_IGNORE:
  				c_stat = TXN_IGNORE;
  				break;
  			default:
  				c_stat = TXN_ABORT;
  			}
  			ret = __db_txnlist_update(env,
  			    info, argp->child, c_stat, NULL, &tmpstat, 0);
  		} else if (c_stat == TXN_UNEXPECTED) {
  			/*
  			 * The open after this create failed.  If the parent
  			 * is rolling forward, we need to roll forward.  If
  			 * the parent failed, then we do not want to abort
  			 * (because the file may not be the one in which we
  			 * are interested).
  			 */
  			ret = __db_txnlist_update(env, info, argp->child,
  			    p_stat == TXN_COMMIT ? TXN_COMMIT : TXN_IGNORE,
  			    NULL, &tmpstat, 0);
  		}
  	} else if (op == DB_TXN_OPENFILES) {
  		/*
  		 * If we have a partial subtransaction, then the whole
  		 * transaction should be ignored.
  		 */
  		if ((ret = __db_txnlist_find(env,
  		    info, argp->child, &c_stat)) == DB_NOTFOUND)
  			ret = __db_txnlist_update(env, info,
  			     argp->txnp->txnid, TXN_IGNORE,
  			     NULL, &p_stat, 1);
  	} else if (DB_REDO(op)) {
  		/* Forward Roll */
  		if ((ret =
  		    __db_txnlist_remove(env, info, argp->child)) != 0)
  			__db_errx(env, DB_STR_A("4516",
  			    "Transaction not in list %x", "%x"), argp->child);
  	}
  
  	if (ret == 0)
  		*lsnp = argp->prev_lsn;
  
  out:	__os_free(env, argp);
  
  	return (ret);
  }
  
  /*
   * __txn_restore_txn --
   *	Using only during XA recovery.  If we find any transactions that are
   * prepared, but not yet committed, then we need to restore the transaction's
   * state into the shared region, because the TM is going to issue an abort
   * or commit and we need to respond correctly.
   *
   * lsnp is the LSN of the returned LSN
   * argp is the prepare record (in an appropriate structure)
   *
   * PUBLIC: int __txn_restore_txn __P((ENV *, DB_LSN *, __txn_prepare_args *));
   */
  int
  __txn_restore_txn(env, lsnp, argp)
  	ENV *env;
  	DB_LSN *lsnp;
  	__txn_prepare_args *argp;
  {
  	DB_TXNMGR *mgr;
  	DB_TXNREGION *region;
  	TXN_DETAIL *td;
  	int ret;
  
  	if (argp->gid.size == 0)
  		return (0);
  
  	mgr = env->tx_handle;
  	region = mgr->reginfo.primary;
  	TXN_SYSTEM_LOCK(env);
  
  	/* Allocate a new transaction detail structure. */
  	if ((ret = __env_alloc(&mgr->reginfo, sizeof(TXN_DETAIL), &td)) != 0) {
  		TXN_SYSTEM_UNLOCK(env);
  		return (ret);
  	}
  
  	/* Place transaction on active transaction list. */
  	SH_TAILQ_INSERT_HEAD(&region->active_txn, td, links, __txn_detail);
  	region->curtxns++;
  
  	td->txnid = argp->txnp->txnid;
  	__os_id(env->dbenv, &td->pid, &td->tid);
  	td->last_lsn = *lsnp;
  	td->begin_lsn = argp->begin_lsn;
  	td->parent = INVALID_ROFF;
  	td->name = INVALID_ROFF;
  	SH_TAILQ_INIT(&td->kids);
  	MAX_LSN(td->read_lsn);
  	MAX_LSN(td->visible_lsn);
  	td->mvcc_ref = 0;
  	td->mvcc_mtx = MUTEX_INVALID;
  	td->status = TXN_PREPARED;
  	td->flags = TXN_DTL_RESTORED;
  	memcpy(td->gid, argp->gid.data, argp->gid.size);
  	td->nlog_dbs = 0;
  	td->nlog_slots = TXN_NSLOTS;
  	td->log_dbs = R_OFFSET(&mgr->reginfo, td->slots);
  
  	region->stat.st_nrestores++;
  #ifdef HAVE_STATISTICS
  	STAT_INC(env, txn, nactive, region->stat.st_nactive, td->txnid);
  	if (region->stat.st_nactive > region->stat.st_maxnactive)
  		STAT_SET(env, txn, maxnactive, region->stat.st_maxnactive,
  		    region->stat.st_nactive, td->txnid);
  #endif
  	TXN_SYSTEM_UNLOCK(env);
  	return (0);
  }
  
  /*
   * __txn_recycle_recover --
   *	Recovery function for recycle.
   *
   * PUBLIC: int __txn_recycle_recover
   * PUBLIC:   __P((ENV *, DBT *, DB_LSN *, db_recops, void *));
   */
  int
  __txn_recycle_recover(env, dbtp, lsnp, op, info)
  	ENV *env;
  	DBT *dbtp;
  	DB_LSN *lsnp;
  	db_recops op;
  	void *info;
  {
  	__txn_recycle_args *argp;
  	int ret;
  
  #ifdef DEBUG_RECOVER
  	(void)__txn_child_print(env, dbtp, lsnp, op, info);
  #endif
  	if ((ret = __txn_recycle_read(env, dbtp->data, &argp)) != 0)
  		return (ret);
  
  	COMPQUIET(lsnp, NULL);
  
  	if ((ret = __db_txnlist_gen(env, info,
  	    DB_UNDO(op) ? -1 : 1, argp->min, argp->max)) != 0)
  		return (ret);
  
  	__os_free(env, argp);
  
  	return (0);
  }
  
  /*
   * PUBLIC: int __txn_regop_42_recover
   * PUBLIC:    __P((ENV *, DBT *, DB_LSN *, db_recops, void *));
   *
   * These records are only ever written for commits.  Normally, we redo any
   * committed transaction, however if we are doing recovery to a timestamp, then
   * we may treat transactions that committed after the timestamp as aborted.
   */
  int
  __txn_regop_42_recover(env, dbtp, lsnp, op, info)
  	ENV *env;
  	DBT *dbtp;
  	DB_LSN *lsnp;
  	db_recops op;
  	void *info;
  {
  	__txn_regop_42_args *argp;
  	DB_TXNHEAD *headp;
  	u_int32_t status;
  	int ret;
  
  #ifdef DEBUG_RECOVER
  	(void)__txn_regop_42_print(env, dbtp, lsnp, op, info);
  #endif
  
  	if ((ret = __txn_regop_42_read(env, dbtp->data, &argp)) != 0)
  		return (ret);
  
  	headp = info;
  	/*
  	 * We are only ever called during FORWARD_ROLL or BACKWARD_ROLL.
  	 * We check for the former explicitly and the last two clauses
  	 * apply to the BACKWARD_ROLL case.
  	 */
  
  	if (op == DB_TXN_FORWARD_ROLL) {
  		/*
  		 * If this was a 2-phase-commit transaction, then it
  		 * might already have been removed from the list, and
  		 * that's OK.  Ignore the return code from remove.
  		 */
  		if ((ret = __db_txnlist_remove(env,
  		    info, argp->txnp->txnid)) != DB_NOTFOUND && ret != 0)
  			goto err;
  	} else if ((env->dbenv->tx_timestamp != 0 &&
  	    argp->timestamp > (int32_t)env->dbenv->tx_timestamp) ||
  	    (!IS_ZERO_LSN(headp->trunc_lsn) &&
  	    LOG_COMPARE(&headp->trunc_lsn, lsnp) < 0)) {
  		/*
  		 * We failed either the timestamp check or the trunc_lsn check,
  		 * so we treat this as an abort even if it was a commit record.
  		 */
  		if ((ret = __db_txnlist_update(env, info,
  		    argp->txnp->txnid, TXN_ABORT, NULL, &status, 1)) != 0)
  			goto err;
  		else if (status != TXN_IGNORE && status != TXN_OK)
  			goto err;
  	} else {
  		/* This is a normal commit; mark it appropriately. */
  		if ((ret = __db_txnlist_update(env,
  		    info, argp->txnp->txnid, argp->opcode, lsnp,
  		    &status, 0)) == DB_NOTFOUND) {
  			if ((ret = __db_txnlist_add(env,
  			    info, argp->txnp->txnid,
  			    argp->opcode == TXN_ABORT ?
  			    TXN_IGNORE : argp->opcode, lsnp)) != 0)
  				goto err;
  		} else if (ret != 0 ||
  		    (status != TXN_IGNORE && status != TXN_OK))
  			goto err;
  	}
  
  	if (ret == 0)
  		*lsnp = argp->prev_lsn;
  
  	if (0) {
  err:		__db_errx(env, DB_STR_A("4517",
  		    "txnid %lx commit record found, already on commit list",
  		    "%lx"), (u_long)argp->txnp->txnid);
  		ret = EINVAL;
  	}
  	__os_free(env, argp);
  
  	return (ret);
  }
  
  /*
   * PUBLIC: int __txn_ckp_42_recover
   * PUBLIC: __P((ENV *, DBT *, DB_LSN *, db_recops, void *));
   */
  int
  __txn_ckp_42_recover(env, dbtp, lsnp, op, info)
  	ENV *env;
  	DBT *dbtp;
  	DB_LSN *lsnp;
  	db_recops op;
  	void *info;
  {
  	__txn_ckp_42_args *argp;
  	int ret;
  
  #ifdef DEBUG_RECOVER
  	__txn_ckp_42_print(env, dbtp, lsnp, op, info);
  #endif
  	if ((ret = __txn_ckp_42_read(env, dbtp->data, &argp)) != 0)
  		return (ret);
  
  	if (op == DB_TXN_BACKWARD_ROLL)
  		__db_txnlist_ckp(env, info, lsnp);
  
  	*lsnp = argp->last_ckp;
  	__os_free(env, argp);
  	return (DB_TXN_CKP);
  }
  