yaffs2 文件系统在Linux上的移植问题

来源：互联网发布：大津阈值分割算法编辑：程序博客网时间：2024/05/01 23:36

最近刚学嵌入式Linux这块儿，在参考朱兆琪的《嵌入式Linux手册》中的文件系统移植，书中写到

下载好yaffs2之后打补丁，之后配置，在执行make uImage，可是没有出现书中所说的错误，在网上搜索一些资料，在Linux 2.6之后确实存在 yaffs2 在Linux 上的移植问题，

大概原因是之后的Linux版本的 VFS发生了一些变化。但当我下载亚飞yaffs2后，并给Linux打补丁，make uImage ,发现并没有问题，这是什么原因的？当我打开文件

./Linux 3.6.7/fs/yaffs2/yaffs2_vfs.c 文件，发现了一个地方

/* * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. * * Copyright (C) 2002-2011 Aleph One Ltd. *   for Toby Churchill Ltd and Brightstar Engineering * * Created by Charles Manning <charles@aleph1.co.uk> * Acknowledgements: * Luc van OostenRyck for numerous patches. * Nick Bane for numerous patches. * Nick Bane for 2.5/2.6 integration. * Andras Toth for mknod rdev issue. * Michael Fischer for finding the problem with inode inconsistency. * Some code bodily lifted from JFFS * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. *//* * * This is the file system front-end to YAFFS that hooks it up to * the VFS. * * Special notes: * >> 2.4: sb->u.generic_sbp points to the struct yaffs_dev associated with *         this superblock * >> 2.6: sb->s_fs_info  points to the struct yaffs_dev associated with this *         superblock * >> inode->u.generic_ip points to the associated struct yaffs_obj. *//* * There are two variants of the VFS glue code. This variant should compile * for any version of Linux. */#include <linux/version.h>#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 10))#define YAFFS_COMPILE_BACKGROUND#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 23))#define YAFFS_COMPILE_FREEZER#endif#endif#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 28))#define YAFFS_COMPILE_EXPORTFS#endif#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 35))#define YAFFS_USE_SETATTR_COPY#define YAFFS_USE_TRUNCATE_SETSIZE#endif#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 35))#define YAFFS_HAS_EVICT_INODE#endif#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 13))#define YAFFS_NEW_FOLLOW_LINK 1#else#define YAFFS_NEW_FOLLOW_LINK 0#endif#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 6, 0))#define YAFFS_HAS_WRITE_SUPER#endif#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19))#include <linux/config.h>#endif#include <linux/kernel.h>#include <linux/module.h>#include <linux/slab.h>#include <linux/init.h>#include <linux/fs.h>#include <linux/proc_fs.h>#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 39))#include <linux/smp_lock.h>#endif#include <linux/pagemap.h>#include <linux/mtd/mtd.h>#include <linux/interrupt.h>#include <linux/string.h>#include <linux/ctype.h>#if (YAFFS_NEW_FOLLOW_LINK == 1)#include <linux/namei.h>#endif#ifdef YAFFS_COMPILE_EXPORTFS#include <linux/exportfs.h>#endif#ifdef YAFFS_COMPILE_BACKGROUND#include <linux/kthread.h>#include <linux/delay.h>#endif#ifdef YAFFS_COMPILE_FREEZER#include <linux/freezer.h>#endif#include <asm/div64.h>#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))#include <linux/statfs.h>#define UnlockPage(p) unlock_page(p)#define Page_Uptodate(page)test_bit(PG_uptodate, &(page)->flags)/* FIXME: use sb->s_id instead ? */#define yaffs_devname(sb, buf)bdevname(sb->s_bdev, buf)#else#include <linux/locks.h>#defineBDEVNAME_SIZE0#defineyaffs_devname(sb, buf)kdevname(sb->s_dev)#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 5, 0))/* added NCB 26/5/2006 for 2.4.25-vrs2-tcl1 kernel */#define __user#endif#endif#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 26))#define YPROC_ROOT  (&proc_root)#else#define YPROC_ROOT  NULL#endif#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 26))#define Y_INIT_TIMER(a)init_timer(a)#else#define Y_INIT_TIMER(a)init_timer_on_stack(a)#endif#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 27))#define YAFFS_USE_WRITE_BEGIN_END 1#else#define YAFFS_USE_WRITE_BEGIN_END 0#endif#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 6, 0))#define YAFFS_SUPER_HAS_DIRTY#endif#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 2, 0))#define set_nlink(inode, count)  do { (inode)->i_nlink = (count); } while(0)#endif#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 28))static uint32_t YCALCBLOCKS(uint64_t partition_size, uint32_t block_size){uint64_t result = partition_size;do_div(result, block_size);return (uint32_t) result;}#else#define YCALCBLOCKS(s, b) ((s)/(b))#endif

具体查看该文件。

经过分析，最新的yaffs2是应该支持 linux 3.6.7 的，意即可以直接给Linux 3.6.7以上版本打补丁而不需修改，但是目前没有发现时候是其他地方的问题，如有发现分析错误的地方可以与我联系，一起分享。

好了，新手第一篇博客，我会更加努力改进学习~

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