yaffs2 文件系统在Linux上的移植问题
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
* 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
#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
#endif
#include
#include
#include
#include
#include
#include
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 39))
#include
#endif
#include
#include
#include
#include
#include
#if (YAFFS_NEW_FOLLOW_LINK == 1)
#include
#endif
#ifdef YAFFS_COMPILE_EXPORTFS
#include
#endif
#ifdef YAFFS_COMPILE_BACKGROUND
#include
#include
#endif
#ifdef YAFFS_COMPILE_FREEZER
#include
#endif
#include
#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
#include
#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
#define BDEVNAME_SIZE 0
#define yaffs_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 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~