db_rec.c

这是国外的resip协议栈

		 * link its next pointer to the free list.
		 */
		P_INIT(pagep, file_dbp->pgsize,
		    argp->pgno, PGNO_INVALID, argp->next, 0, P_INVALID);

		pagep->lsn = argp->page_lsn;
		modified = 1;
	}

do_truncate:
	/*
	 * If the page was newly created, give it back, if
	 * possible.  Otherwise put it into limbo.
	 */
	if ((pagep == NULL || IS_ZERO_LSN(LSN(pagep))) &&
	    IS_ZERO_LSN(argp->page_lsn) && DB_UNDO(op)) {
#ifdef HAVE_FTRUNCATE
		COMPQUIET(info, NULL);
		/* Discard the page. */
		if (pagep != NULL) {
			if ((ret =
			     __memp_fput(mpf, pagep, DB_MPOOL_DISCARD)) != 0)
				goto out;
			pagep = NULL;
			/* Give the page back to the OS. */
			if (meta->last_pgno <= argp->pgno &&
			    (ret = __memp_ftruncate(mpf, argp->pgno, 0)) != 0)
				goto out;
		}
#else
		/* Put the page in limbo.*/
		if ((ret = __db_add_limbo(dbenv,
		    info, argp->fileid, argp->pgno, 1)) != 0)
			goto out;
		/* The last_pgno grows if this was a new page. */
		if (argp->pgno > meta->last_pgno) {
			meta->last_pgno = argp->pgno;
			meta_modified = 1;
		}
#endif
	}

	if (pagep != NULL &&
	     (ret = __memp_fput(mpf,
	     pagep, modified ? DB_MPOOL_DIRTY : 0)) != 0)
		goto out;
	pagep = NULL;

	if ((ret = __memp_fput(mpf,
	    meta, meta_modified ? DB_MPOOL_DIRTY : 0)) != 0)
		goto out;
	meta = NULL;

done:	*lsnp = argp->prev_lsn;
	ret = 0;

out:	if (pagep != NULL)
		(void)__memp_fput(mpf, pagep, 0);
	if (meta != NULL)
		(void)__memp_fput(mpf, meta, 0);
	if (ret == ENOENT && op == DB_TXN_BACKWARD_ALLOC)
		ret = 0;
	REC_CLOSE;
}

/*
 * __db_pg_free_recover_int --
 */
static int
__db_pg_free_recover_int(dbenv, argp, file_dbp, lsnp, mpf, op, data)
	DB_ENV *dbenv;
	__db_pg_freedata_args *argp;
	DB *file_dbp;
	DB_LSN *lsnp;
	DB_MPOOLFILE *mpf;
	db_recops op;
	int data;
{
	DBMETA *meta;
	DB_LSN copy_lsn;
	PAGE *pagep;
	db_pgno_t pgno;
	int cmp_n, cmp_p, meta_modified, modified, ret;

	meta = NULL;
	pagep = NULL;
	meta_modified = modified = 0;

	/*
	 * Get the metapage first so we can see where we are.
	 */
	pgno = PGNO_BASE_MD;
	if ((ret = __memp_fget(mpf, &pgno, 0, &meta)) != 0) {
		/* The metadata page must always exist. */
		ret = __db_pgerr(file_dbp, pgno, ret);
		goto out;
	}
	cmp_n = log_compare(lsnp, &LSN(meta));
	cmp_p = log_compare(&LSN(meta), &argp->meta_lsn);
	CHECK_LSN(op, cmp_p, &LSN(meta), &argp->meta_lsn);

	/*
	 * Fix up the metadata page.  If we're redoing or undoing the operation
	 * we get the page and update its LSN, last and free pointer.
	 */
	if (cmp_p == 0 && DB_REDO(op)) {
#ifdef HAVE_FTRUNCATE
		/*
		 * If we are at the end of the file truncate, otherwise
		 * put on the free list.
		*/
		if (argp->pgno == argp->last_pgno)
			meta->last_pgno = argp->pgno - 1;
		else
			meta->free = argp->pgno;
#else
		/* Need to redo the deallocation. */
		meta->free = argp->pgno;
		/*
		 * If this was a compensating transaction and
		 * we are a replica, then we never executed the
		 * original allocation which incremented meta->free.
		 */
		if (meta->last_pgno < meta->free)
			meta->last_pgno = meta->free;
#endif
		LSN(meta) = *lsnp;
		meta_modified = 1;
	} else if (cmp_n == 0 && DB_UNDO(op)) {
		/* Need to undo the deallocation. */
		meta->free = argp->next;
		LSN(meta) = argp->meta_lsn;
		if (meta->last_pgno < argp->pgno)
			meta->last_pgno = argp->pgno;
		meta_modified = 1;
	}

	/*
	 * Get the freed page.  If we support truncate then don't
	 * create the page if we are going to free it.  If we're
	 * redoing the operation we get the page and explicitly discard
	 * its contents, then update its LSN.  If we're undoing the
	 * operation, we get the page and restore its header.
	 * If we don't support truncate, then we must create the page
	 * and roll it back.
	 */
#ifdef HAVE_FTRUNCATE
	if (DB_REDO(op) || meta->last_pgno < argp->pgno) {
		if ((ret = __memp_fget(mpf, &argp->pgno, 0, &pagep)) != 0) {
			if (ret == DB_PAGE_NOTFOUND)
				goto done;
			goto out;
		}
	} else
#endif
	if ((ret =
	    __memp_fget(mpf, &argp->pgno, DB_MPOOL_CREATE, &pagep)) != 0)
		goto out;

	(void)__ua_memcpy(&copy_lsn, &LSN(argp->header.data), sizeof(DB_LSN));
	cmp_n = IS_ZERO_LSN(LSN(pagep)) ? 0 : log_compare(lsnp, &LSN(pagep));
	cmp_p = log_compare(&LSN(pagep), &copy_lsn);

#ifdef HAVE_FTRUNCATE
	/*
	 * This page got extended by a later allocation,
	 * but its allocation was not in the scope of this
	 * recovery pass.
	 */
	if (IS_ZERO_LSN(LSN(pagep)))
		cmp_p = 0;
#endif

	CHECK_LSN(op, cmp_p, &LSN(pagep), &copy_lsn);
	if (DB_REDO(op) &&
	    (cmp_p == 0 ||
	    (IS_ZERO_LSN(copy_lsn) &&
	    log_compare(&LSN(pagep), &argp->meta_lsn) <= 0))) {
		/* Need to redo the deallocation. */
#ifdef HAVE_FTRUNCATE
		if (meta->last_pgno <= argp->pgno) {
			if ((ret =
			    __memp_fput(mpf, pagep, DB_MPOOL_DISCARD)) != 0)
				goto out;
			pagep = NULL;
			if ((ret = __memp_ftruncate(mpf, argp->pgno, 0)) != 0)
				goto out;
		} else if (argp->last_pgno == argp->pgno) {
			/* The page was truncated at runtime, zero it out. */
			P_INIT(pagep, 0, PGNO_INVALID,
			    PGNO_INVALID, PGNO_INVALID, 0, P_INVALID);
			ZERO_LSN(pagep->lsn);
			modified = 1;
		} else
#endif
		{
			P_INIT(pagep, file_dbp->pgsize,
			    argp->pgno, PGNO_INVALID, argp->next, 0, P_INVALID);
			pagep->lsn = *lsnp;

			modified = 1;
		}
	} else if (cmp_n == 0 && DB_UNDO(op)) {
		/* Need to reallocate the page. */
		memcpy(pagep, argp->header.data, argp->header.size);
		if (data)
			memcpy((u_int8_t*)pagep + pagep->hf_offset,
			     argp->data.data, argp->data.size);

		modified = 1;
	}
	if (pagep != NULL &&
	    (ret = __memp_fput(mpf, pagep, modified ? DB_MPOOL_DIRTY : 0)) != 0)
		goto out;

	pagep = NULL;
#ifdef HAVE_FTRUNCATE
done:
#endif
	if ((ret = __memp_fput(mpf,
	     meta, meta_modified ? DB_MPOOL_DIRTY : 0)) != 0)
		goto out;
	meta = NULL;

	ret = 0;

out:	if (pagep != NULL)
		(void)__memp_fput(mpf, pagep, 0);
	if (meta != NULL)
		(void)__memp_fput(mpf, meta, 0);

	return (ret);
}

/*
 * __db_pg_free_recover --
 *	Recovery function for pg_free.
 *
 * PUBLIC: int __db_pg_free_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__db_pg_free_recover(dbenv, dbtp, lsnp, op, info)
	DB_ENV *dbenv;
	DBT *dbtp;
	DB_LSN *lsnp;
	db_recops op;
	void *info;
{
	DB *file_dbp;
	DBC *dbc;
	DB_MPOOLFILE *mpf;
	__db_pg_free_args *argp;
	int ret;

	COMPQUIET(info, NULL);
	REC_PRINT(__db_pg_free_print);
	REC_INTRO(__db_pg_free_read, 1);

	ret = __db_pg_free_recover_int(dbenv,
	     (__db_pg_freedata_args *)argp, file_dbp, lsnp, mpf, op, 0);

done:	*lsnp = argp->prev_lsn;
out:
	REC_CLOSE;
}

/*
 * __db_pg_new_recover --
 *	A new page from the file was put on the free list.
 * This record is only generated during a LIMBO_COMPENSATE.
 *
 * PUBLIC: int __db_pg_new_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__db_pg_new_recover(dbenv, dbtp, lsnp, op, info)
	DB_ENV *dbenv;
	DBT *dbtp;
	DB_LSN *lsnp;
	db_recops op;
	void *info;
{
#ifndef HAVE_FTRUNCATE
	DB *file_dbp;
	DBC *dbc;
	DB_MPOOLFILE *mpf;
	__db_pg_free_args *argp;
	int ret;

	REC_PRINT(__db_pg_free_print);
	REC_INTRO(__db_pg_free_read, 1);
	COMPQUIET(op, DB_TXN_ABORT);

	if ((ret =
	    __db_add_limbo(dbenv, info, argp->fileid, argp->pgno, 1)) == 0)
		*lsnp = argp->prev_lsn;

done:
out:
	REC_CLOSE;
#else
	COMPQUIET(dbenv, NULL);
	COMPQUIET(dbtp, NULL);
	COMPQUIET(lsnp, NULL);
	COMPQUIET(op, DB_TXN_PRINT);
	COMPQUIET(info, NULL);
	return (0);
#endif
}

/*
 * __db_pg_freedata_recover --
 *	Recovery function for pg_freedata.
 *
 * PUBLIC: int __db_pg_freedata_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__db_pg_freedata_recover(dbenv, dbtp, lsnp, op, info)
	DB_ENV *dbenv;
	DBT *dbtp;
	DB_LSN *lsnp;
	db_recops op;
	void *info;
{
	DB *file_dbp;
	DBC *dbc;
	DB_MPOOLFILE *mpf;
	__db_pg_freedata_args *argp;
	int ret;

	COMPQUIET(info, NULL);
	REC_PRINT(__db_pg_freedata_print);
	REC_INTRO(__db_pg_freedata_read, 1);

	ret = __db_pg_free_recover_int(dbenv, argp, file_dbp, lsnp, mpf, op, 1);

done:	*lsnp = argp->prev_lsn;
out:
	REC_CLOSE;
}

/*
 * __db_cksum_recover --
 *	Recovery function for checksum failure log record.
 *
 * PUBLIC: int __db_cksum_recover __P((DB_ENV *,
 * PUBLIC:      DBT *, DB_LSN *, db_recops, void *));
 */
int
__db_cksum_recover(dbenv, dbtp, lsnp, op, info)
	DB_ENV *dbenv;
	DBT *dbtp;
	DB_LSN *lsnp;
	db_recops op;
	void *info;
{
	__db_cksum_args *argp;

	int ret;

	COMPQUIET(info, NULL);
	COMPQUIET(lsnp, NULL);
	COMPQUIET(op, DB_TXN_ABORT);

	REC_PRINT(__db_cksum_print);

	if ((ret = __db_cksum_read(dbenv, dbtp->data, &argp)) != 0)
		return (ret);

	/*
	 * We had a checksum failure -- the only option is to run catastrophic
	 * recovery.
	 */
	if (F_ISSET(dbenv, DB_ENV_FATAL))
		ret = 0;
	else {
		__db_err(dbenv,
		    "Checksum failure requires catastrophic recovery");
		ret = __db_panic(dbenv, DB_RUNRECOVERY);
	}

	__os_free(dbenv, argp);
	return (ret);
}

/*
 * __db_pg_prepare_recover --
 *	Recovery function for pg_prepare.
 *
 * PUBLIC: int __db_pg_prepare_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__db_pg_prepare_recover(dbenv, dbtp, lsnp, op, info)
	DB_ENV *dbenv;
	DBT *dbtp;
	DB_LSN *lsnp;
	db_recops op;
	void *info;
{
#ifndef HAVE_FTRUNCATE
	__db_pg_prepare_args *argp;
	DB *file_dbp;
	DBC *dbc;
	DB_MPOOLFILE *mpf;
	PAGE *pagep;
	int ret, t_ret;

	REC_PRINT(__db_pg_prepare_print);
	REC_INTRO(__db_pg_prepare_read, 1);

	mpf = file_dbp->mpf;

	/*
	 * If this made it into the limbo list at prepare time then
	 * it was a new free page allocated by an aborted subtransaction.
	 * Only that subtransaction could have toched the page.
	 * All other pages in the free list at this point are
	 * either of the same nature or were put there by this subtransactions
	 * other subtransactions that followed this one.  If
	 * they were put there by this subtransaction the log records
	 * of the following allocations will reflect that.
	 * Note that only one transaction could have had the
	 * metapage locked at the point of the crash.
	 * All this is to say that we can P_INIT this page without
	 * loosing other pages on the free list because they
	 * will be linked in by records earlier in the log for
	 * this transaction which we will roll back.
	 */
	if (op == DB_TXN_ABORT) {
		if ((ret = __memp_fget(
		    mpf, &argp->pgno, DB_MPOOL_CREATE, &pagep)) != 0)
			goto out;
		P_INIT(pagep, file_dbp->pgsize,
		    argp->pgno, PGNO_INVALID, PGNO_INVALID, 0, P_INVALID);
		ZERO_LSN(pagep->lsn);
		ret = __db_add_limbo(dbenv, info, argp->fileid, argp->pgno, 1);
		if ((t_ret =
		    __memp_fput(mpf, pagep, DB_MPOOL_DIRTY)) != 0 && ret == 0)
			ret = t_ret;
	}

done:	if (ret == 0)
		*lsnp = argp->prev_lsn;
out:	REC_CLOSE;
#else
	COMPQUIET(dbenv, NULL);
	COMPQUIET(dbtp, NULL);
	COMPQUIET(lsnp, NULL);
	COMPQUIET(op, DB_TXN_PRINT);
	COMPQUIET(info, NULL);
	return (0);
#endif

}

/*
 * __db_pg_init_recover --
 *	Recovery function to reinit pages for truncate.
 *
 * PUBLIC: int __db_pg_init_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__db_pg_init_recover(dbenv, dbtp, lsnp, op, info)
	DB_ENV *dbenv;
	DBT *dbtp;
	DB_LSN *lsnp;
	db_recops op;
	void *info;
{
	__db_pg_init_args *argp;
	DB *file_dbp;
	DBC *dbc;
	DB_LSN copy_lsn;
	DB_MPOOLFILE *mpf;
	PAGE *pagep;
	int cmp_n, cmp_p, modified, ret;

	COMPQUIET(info, NULL);
	REC_PRINT(__db_pg_init_print);
	REC_INTRO(__db_pg_init_read, 1);

	mpf = file_dbp->mpf;
	REC_FGET(mpf, argp->pgno, &pagep, done);

	modified = 0;
	(void)__ua_memcpy(&copy_lsn, &LSN(argp->header.data), sizeof(DB_LSN));
	cmp_n = log_compare(lsnp, &LSN(pagep));
	cmp_p = log_compare(&LSN(pagep), &copy_lsn);
	CHECK_LSN(op, cmp_p, &LSN(pagep), &copy_lsn);

	if (cmp_p == 0 && DB_REDO(op)) {
		P_INIT(pagep, file_dbp->pgsize, PGNO(pagep), PGNO_INVALID,
		    PGNO_INVALID, TYPE(pagep) == P_HASH ? 0 : 1, TYPE(pagep));
		pagep->lsn = *lsnp;
		modified = 1;
	} else if (cmp_n == 0 && DB_UNDO(op)) {
		/* Put the data back on the page. */
		memcpy(pagep, argp->header.data, argp->header.size);
		if (argp->data.size > 0)
			memcpy((u_int8_t*)pagep + pagep->hf_offset,
			     argp->data.data, argp->data.size);

		modified = 1;
	}
	if ((ret = __memp_fput(mpf, pagep, modified ? DB_MPOOL_DIRTY : 0)) != 0)
		goto out;

done:	*lsnp = argp->prev_lsn;
out:
	REC_CLOSE;
}