/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* linux/include/linux/jbd2.h
*
* Written by Stephen C. Tweedie <sct@redhat.com>
*
* Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved
*
* Definitions for transaction data structures for the buffer cache
* filesystem journaling support.
*/
#ifndef _LINUX_JBD2_H
#define _LINUX_JBD2_H
/* Allow this file to be included directly into e2fsprogs */
#ifndef __KERNEL__
#include "jfs_compat.h"
#define JBD2_DEBUG
#else
#include <linux/types.h>
#include <linux/buffer_head.h>
#include <linux/journal-head.h>
#include <linux/stddef.h>
#include <linux/mutex.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/bit_spinlock.h>
#include <linux/blkdev.h>
#include <crypto/hash.h>
#endif
#define journal_oom_retry 1
/*
* Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds
* certain classes of error which can occur due to failed IOs. Under
* normal use we want ext4 to continue after such errors, because
* hardware _can_ fail, but for debugging purposes when running tests on
* known-good hardware we may want to trap these errors.
*/
#undef JBD2_PARANOID_IOFAIL
/*
* The default maximum commit age, in seconds.
*/
#define JBD2_DEFAULT_MAX_COMMIT_AGE 5
#ifdef CONFIG_JBD2_DEBUG
/*
* Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal
* consistency checks. By default we don't do this unless
* CONFIG_JBD2_DEBUG is on.
*/
#define JBD2_EXPENSIVE_CHECKING
extern ushort jbd2_journal_enable_debug;
void __jbd2_debug(int level, const char *file, const char *func,
unsigned int line, const char *fmt, ...);
#define jbd_debug(n, fmt, a...) \
__jbd2_debug((n), __FILE__, __func__, __LINE__, (fmt), ##a)
#else
#define jbd_debug(n, fmt, a...) /**/
#endif
extern void *jbd2_alloc(size_t size, gfp_t flags);
extern void jbd2_free(void *ptr, size_t size);
#define JBD2_MIN_JOURNAL_BLOCKS 1024
#ifdef __KERNEL__
/**
* typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
*
* All filesystem modifications made by the process go
* through this handle. Recursive operations (such as quota operations)
* are gathered into a single update.
*
* The buffer credits field is used to account for journaled buffers
* being modified by the running process. To ensure that there is
* enough log space for all outstanding operations, we need to limit the
* number of outstanding buffers possible at any time. When the
* operation completes, any buffer credits not used are credited back to
* the transaction, so that at all times we know how many buffers the
* outstanding updates on a transaction might possibly touch.
*
* This is an
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