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/*
* linux/include/linux/ext3_jbd.h
*
* Written by Stephen C. Tweedie <sct@redhat.com>, 1999
*
* Copyright 1998--1999 Red Hat corp --- All Rights Reserved
*
* This file is part of the Linux kernel and is made available under
* the terms of the GNU General Public License, version 2, or at your
* option, any later version, incorporated herein by reference.
*
* Ext3-specific journaling extensions.
*/
#ifndef _LINUX_EXT3_JBD_H
#define _LINUX_EXT3_JBD_H
#include <linux/fs.h>
#include <linux/jbd.h>
#include <linux/ext3_fs.h>
/* Define the number of blocks we need to account to a transaction to
* modify one block of data.
*
* We may have to touch one inode, one bitmap buffer, up to three
* indirection blocks, the group and superblock summaries, and the data
* block to complete the transaction. */
#define EXT3_SINGLEDATA_TRANS_BLOCKS 8
/* Define the minimum size for a transaction which modifies data. This
* needs to take into account the fact that we may end up modifying two
* quota files too (one for the group, one for the user quota). The
* superblock only gets updated once, of course, so don't bother
* counting that again for the quota updates. */
#define EXT3_DATA_TRANS_BLOCKS (3 * EXT3_SINGLEDATA_TRANS_BLOCKS - 2)
extern int ext3_writepage_trans_blocks(struct inode *inode);
/* Delete operations potentially hit one directory's namespace plus an
* entire inode, plus arbitrary amounts of bitmap/indirection data. Be
* generous. We can grow the delete transaction later if necessary. */
#define EXT3_DELETE_TRANS_BLOCKS (2 * EXT3_DATA_TRANS_BLOCKS + 64)
/* Define an arbitrary limit for the amount of data we will anticipate
* writing to any given transaction. For unbounded transactions such as
* write(2) and truncate(2) we can write more than this, but we always
* start off at the maximum transaction size and grow the transaction
* optimistically as we go. */
#define EXT3_MAX_TRANS_DATA 64
/* We break up a large truncate or write transaction once the handle's
* buffer credits gets this low, we need either to extend the
* transaction or to start a new one. Reserve enough space here for
* inode, bitmap, superblock, group and indirection updates for at least
* one block, plus two quota updates. Quota allocations are not
* needed. */
#define EXT3_RESERVE_TRANS_BLOCKS 12
#endif /* _LINUX_EXT3_JBD_H */
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