text: /*-
   * See the file LICENSE for redistribution information.
   *
   * Copyright (c) 1996, 1997, 1998
   *	Sleepycat Software.  All rights reserved.
   */
  /*
   * Copyright (c) 1995, 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. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the University of
   *	California, Berkeley and its contributors.
   * 4. 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.
   */
  
  #include "config.h"
  
  #ifndef lint
  static const char sccsid[] = "@(#)log_rec.c	10.26 (Sleepycat) 10/21/98";
  #endif /* not lint */
  
  #ifndef NO_SYSTEM_INCLUDES
  #include <sys/types.h>
  
  #include <errno.h>
  #include <string.h>
  #endif
  
  #include "db_int.h"
  #include "shqueue.h"
  #include "log.h"
  #include "db_dispatch.h"
  #include "common_ext.h"
  
  static int __log_do_open __P((DB_LOG *,
      u_int8_t *, char *, DBTYPE, u_int32_t));
  static int __log_lid_to_fname __P((DB_LOG *, u_int32_t, FNAME **));
  static int __log_open_file __P((DB_LOG *, __log_register_args *));
  
  /*
   * PUBLIC: int __log_register_recover
   * PUBLIC:     __P((DB_LOG *, DBT *, DB_LSN *, int, void *));
   */
  int
  __log_register_recover(logp, dbtp, lsnp, redo, info)
  	DB_LOG *logp;
  	DBT *dbtp;
  	DB_LSN *lsnp;
  	int redo;
  	void *info;
  {
  	DB_ENTRY *dbe;
  	__log_register_args *argp;
  	int ret;
  
  #ifdef DEBUG_RECOVER
  	__log_register_print(logp, dbtp, lsnp, redo, info);
  #endif
  	COMPQUIET(info, NULL);
  	COMPQUIET(lsnp, NULL);
  
  	F_SET(logp, DBC_RECOVER);
  
  	if ((ret = __log_register_read(dbtp->data, &argp)) != 0)
  		goto out;
  
  	if ((argp->opcode == LOG_CHECKPOINT && redo == TXN_OPENFILES) ||
  	    (argp->opcode == LOG_OPEN &&
  	    (redo == TXN_REDO || redo == TXN_OPENFILES ||
  	     redo == TXN_FORWARD_ROLL)) ||
  	    (argp->opcode == LOG_CLOSE &&
  	    (redo == TXN_UNDO || redo == TXN_BACKWARD_ROLL))) {
  		/*
  		 * If we are redoing an open or undoing a close, then we need
  		 * to open a file.
  		 */
  		ret = __log_open_file(logp, argp);
  		if (ret == ENOENT) {
  			if (redo == TXN_OPENFILES)
  				__db_err(logp->dbenv, "warning: %s: %s",
  				    argp->name.data, strerror(ENOENT));
  			ret = 0;
  		}
  	} else if (argp->opcode != LOG_CHECKPOINT &&
  	    argp->opcode != LOG_CLOSE) {
  		/*
  		 * If we are undoing an open, then we need to close the file.
  		 * Note that we do *not* close the file if we are redoing a
  		 * close, because we do not log the reference counts on log
  		 * files and we may have had the file open multiple times,
  		 * and therefore, this close should just dec a reference
  		 * count.  However, since we only do one open during a
  		 * checkpoint, this will inadvertently close the file.
  		 *
    		 * If the file is deleted, then we can just ignore this close.
   		 * Otherwise, we should usually have a valid dbp we should
    		 * close or whose reference count should be decremented.
   		 * However, if we shut down without closing a file, we
  		 * may, in fact, not have the file open, and that's OK.
  		 */
  		LOCK_LOGTHREAD(logp);
  		if (argp->id < logp->dbentry_cnt) {
  			dbe = &logp->dbentry[argp->id];
  			if (dbe->dbp != NULL && --dbe->refcount == 0) {
  				ret = dbe->dbp->close(dbe->dbp, 0);
  				if (dbe->name != NULL) {
  					__os_freestr(dbe->name);
  					dbe->name = NULL;
  				}
  				(void)__log_rem_logid(logp, argp->id);
  			}
  		}
  		UNLOCK_LOGTHREAD(logp);
   	} else if (argp->opcode == LOG_CHECKPOINT && redo == TXN_UNDO &&
   	    (argp->id >= logp->dbentry_cnt ||
   	    (!logp->dbentry[argp->id].deleted &&
   	    logp->dbentry[argp->id].dbp == NULL))) {
   		/*
   		 * It's a checkpoint and we are rolling backward.  It
   		 * is possible that the system was shut down and thus
   		 * ended with a stable checkpoint; this file was never
   		 * closed and has therefore not been reopened yet.  If
   		 * so, we need to try to open it.
   		 */
   		ret = __log_open_file(logp, argp);
   		if (ret == ENOENT) {
   			__db_err(logp->dbenv, "warning: %s: %s",
  			    argp->name.data, strerror(ENOENT));
   			ret = 0;
   		}
  	}
  
  out:	F_CLR(logp, DBC_RECOVER);
  	if (argp != NULL)
  		__os_free(argp, 0);
  	return (ret);
  }
  
  /* Hand coded routines. */
  
  /*
   * Called during log_register recovery.  Make sure that we have an
   * entry in the dbentry table for this ndx.
   * Returns 0 on success, non-zero on error.
   */
  static int
  __log_open_file(lp, argp)
  	DB_LOG *lp;
  	__log_register_args *argp;
  {
  	DB_ENTRY *dbe;
    
  	if (argp->name.size == 0)
  		return(0);
    
  	/*
  	 * Because of reference counting, we cannot automatically close files
  	 * during recovery, so when we're opening, we have to check that the
  	 * name we are opening is what we expect.  If it's not, then we close
  	 * the old file and open the new one.
  	 */
  	LOCK_LOGTHREAD(lp);
  	if (argp->id < lp->dbentry_cnt)
  		dbe = &lp->dbentry[argp->id];
  	else
  		dbe = NULL;
  
  	if (dbe != NULL && (dbe->deleted == 1 || dbe->dbp != NULL) &&
  	    dbe->name != NULL && argp->name.data != NULL &&
  	    strncmp(argp->name.data, dbe->name, argp->name.size) == 0) {
  
  		dbe->refcount++;
  		UNLOCK_LOGTHREAD(lp);
  		return (0);
  	}
    	UNLOCK_LOGTHREAD(lp);
  
  	if (dbe != NULL && dbe->dbp != NULL) {
                  (void)dbe->dbp->close(dbe->dbp, 0);
  		if (dbe->name != NULL)
  			__os_freestr(dbe->name);
                  dbe->name = NULL;
  		(void)__log_rem_logid(lp, argp->id);
          }
  
  
  	return (__log_do_open(lp,
  	    argp->uid.data, argp->name.data, argp->ftype, argp->id));
  }
  
  /*
   * __log_do_open --
   * 	Open files referenced in the log.  This is the part of the open that
   * is not protected by the thread mutex.
   */
  
  static int
  __log_do_open(lp, uid, name, ftype, ndx)
  	DB_LOG *lp;
  	u_int8_t *uid;
  	char *name;
  	DBTYPE ftype;
  	u_int32_t ndx;
  {
  	DB *dbp;
  	int ret;
  
  	dbp = NULL;
  	if ((ret = db_open(name, ftype, 0, 0, lp->dbenv, NULL, &dbp)) == 0) {
  		/*
  		 * Verify that we are opening the same file that we were
  		 * referring to when we wrote this log record.
  		 */
  		if (memcmp(uid, dbp->fileid, DB_FILE_ID_LEN) != 0) {
  			(void)dbp->close(dbp, 0);
  			dbp = NULL;
  			ret = ENOENT;
  		}
  	}
  
  	if (ret == 0 || ret == ENOENT)
  		(void)__log_add_logid(lp, dbp, name, ndx);
  
  	return (ret);
  }
  
  /*
   * __log_add_logid --
   *	Adds a DB entry to the log's DB entry table.
   *
   * PUBLIC: int __log_add_logid __P((DB_LOG *, DB *, const char *, u_int32_t));
   */
  int
  __log_add_logid(logp, dbp, name, ndx)
  	DB_LOG *logp;
  	DB *dbp;
  	const char *name;
  	u_int32_t ndx;
  {
  	u_int32_t i;
  	int ret;
  
  	ret = 0;
  
  	LOCK_LOGTHREAD(logp);
  
  	/*
  	 * Check if we need to grow the table.  Note, ndx is 0-based (the
  	 * index into the DB entry table) an dbentry_cnt is 1-based, the
  	 * number of available slots.
  	 */
  	if (logp->dbentry_cnt <= ndx) {
  		if ((ret = __os_realloc(&logp->dbentry,
  		    (ndx + DB_GROW_SIZE) * sizeof(DB_ENTRY))) != 0)
  			goto err;
  
  		/* Initialize the new entries. */
  		for (i = logp->dbentry_cnt; i < ndx + DB_GROW_SIZE; i++) {
  			logp->dbentry[i].dbp = NULL;
  			logp->dbentry[i].deleted = 0;
  			logp->dbentry[i].name = NULL;
  		}
  
  		logp->dbentry_cnt = i;
  	}
  
  	/* Make space for the name and copy it in. */
  	if (name != NULL) {
  		if ((ret = __os_malloc(strlen(name) + 1, 
  		    NULL, &logp->dbentry[ndx].name)) != 0)
  			goto err;
  		strcpy(logp->dbentry[ndx].name, name);
  	}
  
  	if (logp->dbentry[ndx].deleted == 0 && logp->dbentry[ndx].dbp == NULL) {
  		logp->dbentry[ndx].dbp = dbp;
  		logp->dbentry[ndx].refcount = 1;
  		logp->dbentry[ndx].deleted = dbp == NULL;
  	} else
  		logp->dbentry[ndx].refcount++;
  
  
  err:	UNLOCK_LOGTHREAD(logp);
  	return (ret);
  }
  
  
  /*
   * __db_fileid_to_db --
   *	Return the DB corresponding to the specified fileid.
   *
   * PUBLIC: int __db_fileid_to_db __P((DB_LOG *, DB **, u_int32_t));
   */
  int
  __db_fileid_to_db(logp, dbpp, ndx)
  	DB_LOG *logp;
  	DB **dbpp;
  	u_int32_t ndx;
  {
  	int ret;
  	char *name;
  	FNAME *fname;
  
  	ret = 0;
  	LOCK_LOGTHREAD(logp);
  
  	/*
  	 * Under XA, a process different than the one issuing DB
  	 * operations may abort a transaction.  In this case, 
  	 * recovery routines are run by a process that does not
  	 * necessarily have the file open.  In this case, we must
  	 * open the file explicitly.
  	 */
  	if (ndx >= logp->dbentry_cnt ||
  	    (!logp->dbentry[ndx].deleted && logp->dbentry[ndx].dbp == NULL)) {
  		if (__log_lid_to_fname(logp, ndx, &fname) != 0) {
  			/* Couldn't find entry; this is a fatal error. */
  			ret = EINVAL;
  			goto err;
  		}
  		name = R_ADDR(logp, fname->name_off);
  		/*
  		 * __log_do_open is called without protection of the
  		 * log thread lock.
  		 */
  		UNLOCK_LOGTHREAD(logp);
  		/*
  		 * At this point, we are not holding the thread lock, so
  		 * exit directly instead of going through the exit code
  		 * at the bottom.  If the __log_do_open succeeded, then
  		 * we don't need to do any of the remaining error checking
  		 * at the end of this routine.
  		 */
  		if ((ret = __log_do_open(logp,
  		    fname->ufid, name, fname->s_type, ndx)) != 0)
  			return (ret);
  		*dbpp = logp->dbentry[ndx].dbp;
  		return (0);
  	}
  
  	/*
  	 * Return DB_DELETED if the file has been deleted
  	 * (it's not an error).
  	 */
  	if (logp->dbentry[ndx].deleted) {
  		ret = DB_DELETED;
  		goto err;
  	}
  
  	/*
  	 * Otherwise return 0, but if we don't have a corresponding DB,
  	 * it's an error.
  	 */
  	if ((*dbpp = logp->dbentry[ndx].dbp) == NULL)
  		ret = ENOENT;
  
  err:	UNLOCK_LOGTHREAD(logp);
  	return (ret);
  }
  
  /*
   * Close files that were opened by the recovery daemon.
   *
   * PUBLIC: void __log_close_files __P((DB_LOG *));
   */
  void
  __log_close_files(logp)
  	DB_LOG *logp;
  {
  	u_int32_t i;
  
  	LOCK_LOGTHREAD(logp);
  	for (i = 0; i < logp->dbentry_cnt; i++)
  		if (logp->dbentry[i].dbp) {
  			logp->dbentry[i].dbp->close(logp->dbentry[i].dbp, 0);
  			logp->dbentry[i].dbp = NULL;
  			logp->dbentry[i].deleted = 0;
  		}
  	F_CLR(logp, DBC_RECOVER);
  	UNLOCK_LOGTHREAD(logp);
  }
  
  /*
   * PUBLIC: void __log_rem_logid __P((DB_LOG *, u_int32_t));
   */
  void
  __log_rem_logid(logp, ndx)
  	DB_LOG *logp;
  	u_int32_t ndx;
  {
  	LOCK_LOGTHREAD(logp);
  	if (--logp->dbentry[ndx].refcount == 0) {
  		logp->dbentry[ndx].dbp = NULL;
  		logp->dbentry[ndx].deleted = 0;
  	}
  	UNLOCK_LOGTHREAD(logp);
  }
  
  /*
   * __log_lid_to_fname --
   * 	Traverse the shared-memory region looking for the entry that
   * matches the passed log fileid.  Returns 0 on success; -1 on error.
   */
  static int
  __log_lid_to_fname(dblp, lid, fnamep)
  	DB_LOG *dblp;
  	u_int32_t lid;
  	FNAME **fnamep;
  {
  	FNAME *fnp;
  
  	for (fnp = SH_TAILQ_FIRST(&dblp->lp->fq, __fname);
  	    fnp != NULL; fnp = SH_TAILQ_NEXT(fnp, q, __fname)) {
  		if (fnp->ref == 0)	/* Entry not in use. */
  			continue;
  		if (fnp->id == lid) {
  			*fnamep = fnp;
  			return (0);
  		}
  	}
  	return (-1);
  }
  