This commit is contained in:
hwzzy666 2022-07-09 17:14:48 +08:00
commit b2e222c253
17 changed files with 1029 additions and 380 deletions

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@ -101,7 +101,8 @@
"stdio.h": "c",
"wait_queue.h": "c",
"stddef.h": "c",
"spinlock.h": "c"
"spinlock.h": "c",
"stat.h": "c"
},
"C_Cpp.errorSquiggles": "Enabled",
"esbonio.sphinx.confDir": ""

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@ -2,33 +2,35 @@
## 简介
DragonOS的虚拟文件系统是内核中的一层适配器为用户程序或者是系统程序提供了通用的文件系统接口。同时对内核中的不同文件系统提供了统一的抽象。各种具体的文件系统可以挂载到VFS的框架之中。
  DragonOS的虚拟文件系统是内核中的一层适配器为用户程序或者是系统程序提供了通用的文件系统接口。同时对内核中的不同文件系统提供了统一的抽象。各种具体的文件系统可以挂载到VFS的框架之中。
与VFS相关的系统调用有open(), read(), write(), create()等。
  与VFS相关的系统调用有open(), read(), write(), create()等。
### dentry对象
dentry的全称为directory entry是VFS中对于目录项的一种抽象数据结构。当读取具体文件系统时将会由创建dentry对象。dentry对象中包含了指向inode的指针。
  dentry的全称为directory entry是VFS中对于目录项的一种抽象数据结构。当读取具体文件系统时将会由创建dentry对象。dentry对象中包含了指向inode的指针。
dentry对象为真实文件系统上的目录结构建立了缓存一旦内存中存在对应路径的dentry对象我们就能直接获取其中的信息而不需要进行费时的磁盘操作。请注意dentry只是为提高文件系统性能而创建的一个缓存它并不会被写入到磁盘之中。
  dentry对象为真实文件系统上的目录结构建立了缓存一旦内存中存在对应路径的dentry对象我们就能直接获取其中的信息而不需要进行费时的磁盘操作。请注意dentry只是为提高文件系统性能而创建的一个缓存它并不会被写入到磁盘之中。
### inode对象
inode的全称叫做index node即索引节点。一般来说每个dentry都应当包含指向其inode的阵阵。inode是VFS提供的对文件对象的抽象。inode中的信息是从具体文件系统中读取而来也可以被刷回具体的文件系统之中。并且一个inode也可以被多个dentry所引用。
  inode的全称叫做index node即索引节点。一般来说每个dentry都应当包含指向其inode的指针。inode是VFS提供的对文件对象的抽象。inode中的信息是从具体文件系统中读取而来也可以被刷回具体的文件系统之中。并且一个inode也可以被多个dentry所引用。
要查找某个路径下的inode我们需要调用父目录的inode的lookup()方法。请注意,该方法与具体文件系统有关,需要在具体文件系统之中实现。
  要查找某个路径下的inode我们需要调用父目录的inode的lookup()方法。请注意,该方法与具体文件系统有关,需要在具体文件系统之中实现。
### 文件描述符对象
当一个进程试图通过VFS打开某个文件时我们需要为这个进程创建文件描述符对象。每个文件对象都会绑定文件的dentry和文件操作方法结构体还有文件对象的私有信息。
  当一个进程试图通过VFS打开某个文件时我们需要为这个进程创建文件描述符对象。每个文件对象都会绑定文件的dentry和文件操作方法结构体还有文件对象的私有信息。
文件描述符对象中还包含了诸如权限控制、当前访问位置信息等内容以便VFS对文件进行操作。
  文件描述符对象中还包含了诸如权限控制、当前访问位置信息等内容以便VFS对文件进行操作。
我们对文件进行操作都会使用到文件描述符具体来说就是要调用文件描述符之中的file_ops所包含的各种方法。
  我们对文件进行操作都会使用到文件描述符具体来说就是要调用文件描述符之中的file_ops所包含的各种方法。
---
## 注册文件系统到VFS
如果需要注册或取消注册某个具体文件系统到VFS之中则需要以下两个接口
  如果需要注册或取消注册某个具体文件系统到VFS之中则需要以下两个接口
```c
#include<filesystem/VFS/VFS.h>
@ -37,13 +39,13 @@ uint64_t vfs_register_filesystem(struct vfs_filesystem_type_t *fs);
uint64_t vfs_unregister_filesystem(struct vfs_filesystem_type_t *fs);
```
这里需要通过`struct vfs_filesystem_type_t`来描述具体的文件系统。
&emsp;&emsp;这里需要通过`struct vfs_filesystem_type_t`来描述具体的文件系统。
### struct vfs_filesystem_type_t
这个数据结构描述了具体文件系统的一些信息。当我们挂载具体文件系统的时候将会调用它的read_superblock方法以确定要被挂载的文件系统的具体信息。
&emsp;&emsp;这个数据结构描述了具体文件系统的一些信息。当我们挂载具体文件系统的时候将会调用它的read_superblock方法以确定要被挂载的文件系统的具体信息。
该数据结构的定义在`kernel/filesystem/VFS/VFS.h`中,结构如下:
&emsp;&emsp;该数据结构的定义在`kernel/filesystem/VFS/VFS.h`中,结构如下:
```c
struct vfs_filesystem_type_t
@ -58,29 +60,31 @@ struct vfs_filesystem_type_t
**name**
文件系统名称字符串
&emsp;&emsp;文件系统名称字符串
**fs_flags**
文件系统的一些标志位。目前DragonOS尚未实现相关功能。
&emsp;&emsp;文件系统的一些标志位。目前DragonOS尚未实现相关功能。
**read_superblock**
当新的文件系统实例将要被挂载时,将会调用此方法,以读取具体的实例的信息。
&emsp;&emsp;当新的文件系统实例将要被挂载时,将会调用此方法,以读取具体的实例的信息。
**next**
指向链表中下一个`struct vfs_filesystem_type_t`的指针。
&emsp;&emsp;指向链表中下一个`struct vfs_filesystem_type_t`的指针。
---
## 超级块(superblock)对象
    一个超级块对象代表了一个被挂载到VFS中的具体文件系统。
&emsp;&emsp;一个超级块对象代表了一个被挂载到VFS中的具体文件系统。
### struct vfs_superblock_t
    该数据结构为超级块结构体。
&emsp;&emsp;该数据结构为超级块结构体。
    该数据结构定义在`kernel/filesystem/VFS/VFS.h`中,结构如下:
&emsp;&emsp;该数据结构定义在`kernel/filesystem/VFS/VFS.h`中,结构如下:
```c
struct vfs_superblock_t
@ -93,21 +97,21 @@ struct vfs_superblock_t
**root**
    该具体文件系统的根目录的dentry
&emsp;&emsp;该具体文件系统的根目录的dentry
**sb_ops**
    该超级块对象的操作方法。
&emsp;&emsp;该超级块对象的操作方法。
**private_sb_info**
    超级块的私有信息。包含了具体文件系统的私有的、全局性的信息。
&emsp;&emsp;超级块的私有信息。包含了具体文件系统的私有的、全局性的信息。
### struct vfs_super_block_operations_t
    该数据结构为超级块的操作接口
&emsp;&emsp;该数据结构为超级块的操作接口。VFS通过这些接口来操作具体的文件系统的超级块
    该数据结构定义在`kernel/filesystem/VFS/VFS.h`中,结构如下:
&emsp;&emsp;该数据结构定义在`kernel/filesystem/VFS/VFS.h`中,结构如下:
```c
struct vfs_super_block_operations_t
@ -120,4 +124,124 @@ struct vfs_super_block_operations_t
**write_superblock**
    
&emsp;&emsp;将superblock中的信息写入磁盘
**put_superblock**
&emsp;&emsp;释放超级块
**write_inode**
&emsp;&emsp;将inode的信息写入磁盘
---
## 索引结点(inode)对象
&emsp;&emsp;每个inode对象代表了具体的文件系统之中的一个对象目录项
### struct vfs_index_node_t
&emsp;&emsp;该数据结构为inode对象的数据结构与文件系统中的具体的文件结点对象具有一对一映射的关系。
&emsp;&emsp;该数据结构定义在`kernel/filesystem/VFS/VFS.h`中,结构如下:
```c
struct vfs_index_node_t
{
uint64_t file_size; // 文件大小
uint64_t blocks; // 占用的扇区数
uint64_t attribute;
struct vfs_superblock_t *sb;
struct vfs_file_operations_t *file_ops;
struct vfs_inode_operations_t *inode_ops;
void *private_inode_info;
};
```
**file_size**
&emsp;&emsp;文件的大小。若为文件夹,则该值为文件夹内所有文件的大小总和(估计值)。
**blocks**
&emsp;&emsp;文件占用的磁盘块数(扇区数)
**attribute**
&emsp;&emsp;inode的属性。可选值如下
> - VFS_ATTR_FILE
>
> - VFS_ATTR_DIR
>
> - VFS_ATTR_DEVICE
**sb**
&emsp;&emsp;指向文件系统超级块的指针
**file_ops**
&emsp;&emsp;当前文件的操作接口
**inode_ops**
&emsp;&emsp;当前inode的操作接口
**private_inode_info**
&emsp;&emsp;与具体文件系统相关的inode信息。该部分由具体文件系统实现包含该inode在具体文件系统之中的特定格式信息。
### struct vfs_inode_operations_t
&emsp;&emsp;该接口为inode的操作方法接口由具体文件系统实现。并与具体文件系统之中的inode相互绑定。
&emsp;&emsp;该接口定义于`kernel/filesystem/VFS/VFS.h`中,结构如下:
```c
struct vfs_inode_operations_t
{
long (*create)(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_t *dest_dEntry, int mode);
struct vfs_dir_entry_t *(*lookup)(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_t *dest_dEntry);
long (*mkdir)(struct vfs_index_node_t *inode, struct vfs_dir_entry_t *dEntry, int mode);
long (*rmdir)(struct vfs_index_node_t *inode, struct vfs_dir_entry_t *dEntry);
long (*rename)(struct vfs_index_node_t *old_inode, struct vfs_dir_entry_t *old_dEntry, struct vfs_index_node_t *new_inode, struct vfs_dir_entry_t *new_dEntry);
long (*getAttr)(struct vfs_dir_entry_t *dEntry, uint64_t *attr);
long (*setAttr)(struct vfs_dir_entry_t *dEntry, uint64_t *attr);
};
```
**create**
&emsp;&emsp;在父节点下创建一个新的inode并绑定到dest_dEntry上。
&emsp;&emsp;该函数的应当被`sys_open()`系统调用在使用了`O_CREAT`选项打开文件时调用从而创建一个新的文件。请注意传递给create()函数的`dest_dEntry`参数不应包含一个inode也就是说inode对象应当被具体文件系统所创建。
**lookup**
&emsp;&emsp;当VFS需要在父目录中查找一个inode的时候将会调用lookup方法。被查找的目录项的名称将会通过dest_dEntry传给lookup方法。
&emsp;&emsp;若lookup方法找到对应的目录项将填充完善dest_dEntry对象。否则返回NULL。
**mkdir**
&emsp;&emsp;该函数被mkdir()系统调用所调用用于在inode下创建子目录并将子目录的inode绑定到dEntry对象之中。
**rmdir**
&emsp;&emsp;该函数被rmdir()系统调用所调用用于删除给定inode下的子目录项。
**rename**
&emsp;&emsp;该函数被rename系统调用尚未实现所调用用于将给定的目录项重命名。
**getAttr**
&emsp;&emsp;用来获取目录项的属性。
**setAttr**
&emsp;&emsp;用来设置目录项的属性

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@ -18,7 +18,7 @@ LD_LIST := head.o
OBJ_LIST := head.o
kernel_subdirs := common driver process debug
kernel_subdirs := common driver process debug filesystem
@ -78,14 +78,6 @@ cpu.o: common/cpu.c
softirq.o: exception/softirq.c
gcc $(CFLAGS) -c exception/softirq.c -o exception/softirq.o
fat32.o: filesystem/fat32/fat32.c
gcc $(CFLAGS) -c filesystem/fat32/fat32.c -o filesystem/fat32/fat32.o
MBR.o: filesystem/MBR.c
gcc $(CFLAGS) -c filesystem/MBR.c -o filesystem/MBR.o
VFS.o: filesystem/VFS/VFS.c
gcc $(CFLAGS) -c filesystem/VFS/VFS.c -o filesystem/VFS/VFS.o
# IPI的代码
ifeq ($(ARCH), __x86_64__)
@ -164,7 +156,7 @@ all: kernel
echo "Done."
kernel: head.o entry.o main.o printk.o trap.o mm.o slab.o irq.o pic.o sched.o syscall.o multiboot2.o cpu.o acpi.o ps2_keyboard.o ps2_mouse.o ata.o pci.o ahci.o smp.o apu_boot.o rtc.o HPET.o softirq.o timer.o fat32.o MBR.o VFS.o $(OBJ_LIST)
kernel: head.o entry.o main.o printk.o trap.o mm.o slab.o irq.o pic.o sched.o syscall.o multiboot2.o cpu.o acpi.o ps2_keyboard.o ps2_mouse.o ata.o pci.o ahci.o smp.o apu_boot.o rtc.o HPET.o softirq.o timer.o $(OBJ_LIST)
@list='$(kernel_subdirs)'; for subdir in $$list; do \
echo "make all in $$subdir";\

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@ -0,0 +1,20 @@
CFLAGS += -I .
all: fat32.o MBR.o VFS.o fat_ent.o
fat32.o: fat32/fat32.c
gcc $(CFLAGS) -c fat32/fat32.c -o fat32/fat32.o
MBR.o: MBR.c
gcc $(CFLAGS) -c MBR.c -o MBR.o
VFS.o: VFS/VFS.c
gcc $(CFLAGS) -c VFS/VFS.c -o VFS/VFS.o
fat_ent.o: fat32/fat_ent.c
gcc $(CFLAGS) -c fat32/fat_ent.c -o fat32/fat_ent.o
clean:
echo "Done."

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@ -90,7 +90,7 @@ struct vfs_dir_entry_t *vfs_path_walk(const char *path, uint64_t flags)
return parent;
struct vfs_dir_entry_t *dentry;
// kdebug("path before walk:%s", path);
while (true)
{
// 提取出下一级待搜索的目录名或文件名并保存在dEntry_name中
@ -98,7 +98,6 @@ struct vfs_dir_entry_t *vfs_path_walk(const char *path, uint64_t flags)
while ((*path && *path != '\0') && (*path != '/'))
++path;
int tmp_path_len = path - tmp_path;
dentry = (struct vfs_dir_entry_t *)kmalloc(sizeof(struct vfs_dir_entry_t), 0);
memset(dentry, 0, sizeof(struct vfs_dir_entry_t));
// 为目录项的名称分配内存
@ -106,14 +105,15 @@ struct vfs_dir_entry_t *vfs_path_walk(const char *path, uint64_t flags)
// 貌似这里不需要memset因为空间会被覆盖
// memset(dentry->name, 0, tmp_path_len+1);
memcpy(dentry->name, (void*)tmp_path, tmp_path_len);
memcpy(dentry->name, (void *)tmp_path, tmp_path_len);
dentry->name[tmp_path_len] = '\0';
// kdebug("tmp_path_len=%d, dentry->name= %s", tmp_path_len, dentry->name);
dentry->name_length = tmp_path_len;
if (parent->dir_inode->inode_ops->lookup(parent->dir_inode, dentry) == NULL)
{
// 搜索失败
kerror("cannot find the file/dir : %s", dentry->name);
// kerror("cannot find the file/dir : %s", dentry->name);
kfree(dentry->name);
kfree(dentry);
return NULL;
@ -179,7 +179,7 @@ int vfs_fill_dentry(void *buf, ino_t d_ino, char *name, int namelen, unsigned ch
uint64_t sys_mkdir(struct pt_regs *regs)
{
const char *path = (const char *)regs->r8;
kdebug("path = %s", path);
// kdebug("path = %s", path);
mode_t mode = (mode_t)regs->r9;
uint32_t pathlen;
if (regs->cs & USER_CS)
@ -215,11 +215,13 @@ uint64_t sys_mkdir(struct pt_regs *regs)
else
strncpy(buf, path, last_slash);
buf[last_slash + 1] = '\0';
// kdebug("to walk: %s", buf);
// 查找父目录
struct vfs_dir_entry_t *parent_dir = vfs_path_walk(buf, 0);
if (parent_dir == NULL)
{
kwarn("parent dir is NULL.");
kfree(buf);
return -ENOENT;
}
@ -249,12 +251,12 @@ uint64_t sys_mkdir(struct pt_regs *regs)
}
++subdir_dentry->name_length;
kdebug("last_slash=%d", last_slash);
kdebug("name=%s", path + last_slash + 1);
// kdebug("last_slash=%d", last_slash);
// kdebug("name=%s", path + last_slash + 1);
subdir_dentry->parent = parent_dir;
kdebug("to mkdir, parent name=%s", parent_dir->name);
// kdebug("to mkdir, parent name=%s", parent_dir->name);
int retval = parent_dir->dir_inode->inode_ops->mkdir(parent_dir->dir_inode, subdir_dentry, 0);
list_add(&parent_dir->subdirs_list, &subdir_dentry->child_node_list);
kdebug("retval = %d", retval);
// kdebug("retval = %d", retval);
return 0;
}

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@ -12,6 +12,7 @@
#pragma once
#include <common/glib.h>
#include <common/fcntl.h>
struct vfs_superblock_t *vfs_root_sb = NULL;
@ -107,7 +108,13 @@ struct vfs_super_block_operations_t
*/
struct vfs_inode_operations_t
{
long (*create)(struct vfs_index_node_t *inode, struct vfs_dir_entry_t *dEntry, int mode);
/**
* @brief
* @param parent_inode inode结构体
* @param dest_dEntry dentry
* @param mode
*/
long (*create)(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_t *dest_dEntry, int mode);
/**
* @brief
* @param parent_inode

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@ -6,6 +6,7 @@
#include <mm/slab.h>
#include <common/errno.h>
#include <common/stdio.h>
#include "fat_ent.h"
struct vfs_super_block_operations_t fat32_sb_ops;
struct vfs_dir_entry_operations_t fat32_dEntry_ops;
@ -54,58 +55,6 @@ static uint8_t fat32_ChkSum(uint8_t *name)
}
return chksum;
}
/**
* @brief FAT表项
*
* @param fsbi fat32超级块私有信息结构体
* @param cluster
* @return uint32_t
*/
uint32_t fat32_read_FAT_entry(fat32_sb_info_t *fsbi, uint32_t cluster)
{
// 计算每个扇区内含有的FAT表项数
// FAT每项4bytes
uint32_t fat_ent_per_sec = (fsbi->bytes_per_sec >> 2); // 该值应为2的n次幂
uint32_t buf[256];
memset(buf, 0, fsbi->bytes_per_sec);
// 读取一个sector的数据
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
(uint64_t)&buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
// 返回下一个fat表项的值也就是下一个cluster
return buf[cluster & (fat_ent_per_sec - 1)] & 0x0fffffff;
}
/**
* @brief FAT表项
*
* @param fsbi fat32超级块私有信息结构体
* @param cluster
* @param value fat表项的值
* @return uint32_t errcode
*/
uint32_t fat32_write_FAT_entry(fat32_sb_info_t *fsbi, uint32_t cluster, uint32_t value)
{
// 计算每个扇区内含有的FAT表项数
// FAT每项4bytes
uint32_t fat_ent_per_sec = (fsbi->bytes_per_sec >> 2); // 该值应为2的n次幂
uint32_t *buf = kmalloc(fsbi->bytes_per_sec, 0);
memset(buf, 0, fsbi->bytes_per_sec);
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
(uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
buf[cluster & (fat_ent_per_sec - 1)] = (buf[cluster & (fat_ent_per_sec - 1)] & 0xf0000000) | (value & 0x0fffffff);
// 向FAT1和FAT2写入数据
ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
(uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, fsbi->FAT2_base_sector + (cluster / fat_ent_per_sec), 1,
(uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
kfree(buf);
return 0;
}
/**
* @brief
@ -190,6 +139,8 @@ struct vfs_dir_entry_t *fat32_lookup(struct vfs_index_node_t *parent_inode, stru
if (js >= dest_dentry->name_length) // 找到需要的目录项,返回
{
// kdebug("found target long name.");
goto find_lookup_success;
}
@ -200,6 +151,7 @@ struct vfs_dir_entry_t *fat32_lookup(struct vfs_index_node_t *parent_inode, stru
js = 0;
for (int x = 0; x < 8; ++x)
{
// kdebug("no long name, comparing short name");
// kdebug("value = %#02x", tmp_dEntry->DIR_Name[x]);
switch (tmp_dEntry->DIR_Name[x])
{
@ -265,11 +217,16 @@ struct vfs_dir_entry_t *fat32_lookup(struct vfs_index_node_t *parent_inode, stru
break;
default:
++js;
// ++js;
goto continue_cmp_fail;
break;
}
}
if (js > dest_dentry->name_length)
{
kdebug("js > namelen");
goto continue_cmp_fail;
}
// 若短目录项为文件,则匹配扩展名
if (!(tmp_dEntry->DIR_Attr & ATTR_DIRECTORY))
{
@ -320,6 +277,11 @@ struct vfs_dir_entry_t *fat32_lookup(struct vfs_index_node_t *parent_inode, stru
}
}
}
if (js > dest_dentry->name_length)
{
kdebug("js > namelen");
goto continue_cmp_fail;
}
goto find_lookup_success;
continue_cmp_fail:;
}
@ -665,38 +627,7 @@ long fat32_read(struct vfs_file_t *file_ptr, char *buf, int64_t count, long *pos
return retval;
}
/**
* @brief
*
* @param fsbi fat32超级块信息结构体
* @return uint64_t 0
*/
uint64_t fat32_find_available_cluster(fat32_sb_info_t *fsbi)
{
uint64_t sec_per_fat = fsbi->sec_per_FAT;
// 申请1扇区的缓冲区
uint32_t *buf = (uint32_t *)kmalloc(fsbi->bytes_per_sec, 0);
int ent_per_sec = (fsbi->bytes_per_sec >> 2);
for (int i = 0; i < sec_per_fat; ++i)
{
memset(buf, 0, fsbi->bytes_per_sec);
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + i, 1, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
// 依次检查簇是否空闲
for (int j = 0; j < ent_per_sec; ++j)
{
// 找到空闲簇
if ((buf[j] & 0x0fffffff) == 0)
{
kfree(buf);
return i * ent_per_sec + j;
}
}
}
kfree(buf);
return 0;
}
/**
* @brief fat32文件系统写入数据
@ -712,11 +643,9 @@ long fat32_write(struct vfs_file_t *file_ptr, char *buf, int64_t count, long *po
fat32_sb_info_t *fsbi = (fat32_sb_info_t *)(file_ptr->dEntry->dir_inode->sb->private_sb_info);
// First cluster num of the file
uint64_t cluster = finode->first_clus;
uint32_t cluster = finode->first_clus;
int64_t flags = 0;
// kdebug("fsbi->bytes_per_clus=%d fsbi->sec_per_clus=%d finode->first_clus=%d *position=%d", fsbi->bytes_per_clus, fsbi->sec_per_clus, finode->first_clus, *position);
// kdebug("buf=%s", buf);
// clus offset in file
uint64_t clus_offset_in_file = (*position) / fsbi->bytes_per_clus;
// bytes offset in clus
@ -724,9 +653,9 @@ long fat32_write(struct vfs_file_t *file_ptr, char *buf, int64_t count, long *po
if (!cluster) // 起始簇号为0说明是空文件
{
// 找一个可用的
cluster = fat32_find_available_cluster(fsbi);
flags = 1;
// 分配空闲
if (fat32_alloc_clusters(file_ptr->dEntry->dir_inode, &cluster, 1) != 0)
return -ENOSPC;
}
else
{
@ -739,14 +668,7 @@ long fat32_write(struct vfs_file_t *file_ptr, char *buf, int64_t count, long *po
if (!cluster)
return -ENOSPC;
if (flags) // 空文件
{
// kdebug("empty file");
finode->first_clus = cluster;
// 写入目录项
file_ptr->dEntry->dir_inode->sb->sb_ops->write_inode(file_ptr->dEntry->dir_inode);
fat32_write_FAT_entry(fsbi, cluster, 0x0ffffff8); // 写入fat表项
}
int64_t bytes_remain = count;
@ -809,15 +731,13 @@ long fat32_write(struct vfs_file_t *file_ptr, char *buf, int64_t count, long *po
break;
if (next_clus >= 0x0ffffff8) // 已经到达了最后一个簇,需要分配新簇
{
next_clus = fat32_find_available_cluster(fsbi);
if (!next_clus) // 没有空闲簇
if (fat32_alloc_clusters(file_ptr->dEntry->dir_inode, &next_clus, 1) != 0)
{
// 没有空闲簇
kfree(tmp_buffer);
return -ENOSPC;
}
// 将簇加入到文件末尾
fat32_write_FAT_entry(fsbi, cluster, next_clus);
fat32_write_FAT_entry(fsbi, next_clus, 0x0ffffff8);
cluster = next_clus; // 切换当前簇
flags = 1; // 标记当前簇是新分配的簇
}
@ -829,7 +749,7 @@ long fat32_write(struct vfs_file_t *file_ptr, char *buf, int64_t count, long *po
{
file_ptr->dEntry->dir_inode->file_size = *position;
file_ptr->dEntry->dir_inode->sb->sb_ops->write_inode(file_ptr->dEntry->dir_inode);
kdebug("new file size=%ld", *position);
// kdebug("new file size=%ld", *position);
}
kfree(tmp_buffer);
@ -896,120 +816,48 @@ struct vfs_file_operations_t fat32_file_ops =
.readdir = fat32_readdir,
};
// todo: create
long fat32_create(struct vfs_index_node_t *inode, struct vfs_dir_entry_t *dentry, int mode)
{
}
/**
* @brief inode的目录项簇中num个空的目录项
*
* @param parent_inode inode
* @param num
* @param mode
* @param res_sector
* @param res_cluster
* @param res_data_buf_base
* @return struct fat32_Directory_t* entry的指针num个
* @brief
* @param parent_inode inode结构体
* @param dest_dEntry dentry
* @param mode
*/
struct fat32_Directory_t *fat32_find_empty_dentry(struct vfs_index_node_t *parent_inode, uint32_t num, uint32_t mode, uint32_t *res_sector, uint64_t *res_cluster, uint64_t *res_data_buf_base)
long fat32_create(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_t *dest_dEntry, int mode)
{
kdebug("find empty_dentry");
struct fat32_inode_info_t *finode = (struct fat32_inode_info_t *)parent_inode->private_inode_info;
fat32_sb_info_t *fsbi = (fat32_sb_info_t *)parent_inode->sb->private_sb_info;
uint8_t *buf = kmalloc(fsbi->bytes_per_clus, 0);
memset(buf, 0, fsbi->bytes_per_clus);
// 计算父目录项的起始簇号
uint32_t cluster = finode->first_clus;
struct fat32_Directory_t *tmp_dEntry = NULL;
// 指向最终的有用的dentry的指针
struct fat32_Directory_t *result_dEntry = NULL;
while (true)
{
// 计算父目录项的起始LBA扇区号
uint64_t sector = fsbi->first_data_sector + (cluster - 2) * fsbi->sec_per_clus;
// 读取父目录项的起始簇数据
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
tmp_dEntry = (struct fat32_Directory_t *)buf;
// 计数连续的空目录项
uint32_t count_continuity = 0;
// 查找连续num个空闲目录项
for (int i = 0; (i < fsbi->bytes_per_clus) && count_continuity < num; i += 32, ++tmp_dEntry)
{
if (!(tmp_dEntry->DIR_Name[0] == 0xe5 || tmp_dEntry->DIR_Name[0] == 0x00))
{
count_continuity = 0;
continue;
}
if (count_continuity == 0)
result_dEntry = tmp_dEntry;
++count_continuity;
}
// 成功查找到符合要求的目录项
if (count_continuity == num)
{
result_dEntry += (num - 1);
*res_sector = sector;
*res_data_buf_base = (uint64_t)buf;
*res_cluster = cluster;
return result_dEntry;
}
// 当前簇没有发现符合条件的空闲目录项,寻找下一个簇
uint old_cluster = cluster;
cluster = fat32_read_FAT_entry(fsbi, cluster);
if (cluster >= 0x0ffffff7) // 寻找完父目录的所有簇,都没有找到符合要求的空目录项
{
// 新增一个簇
cluster = fat32_find_available_cluster(fsbi);
kdebug("try to allocate a new cluster to parent dentry, cluster=%d, old_cluster=%d", cluster, old_cluster);
if (cluster == 0)
{
kerror("Cannot allocate a new cluster!");
while (1)
pause();
}
fat32_write_FAT_entry(fsbi, old_cluster, cluster);
fat32_write_FAT_entry(fsbi, cluster, 0x0ffffff8);
// 将这个新的簇清空
sector = fsbi->first_data_sector + (cluster - 2) * fsbi->sec_per_clus;
void *tmp_buf = kmalloc(fsbi->bytes_per_clus, 0);
memset(tmp_buf, 0, fsbi->bytes_per_clus);
ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)tmp_buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
kfree(tmp_buf);
}
}
}
/**
* @brief
* @param inode inode
* @param dEntry dentry
* @param mode mode
*/
int64_t fat32_mkdir(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_t *dEntry, int mode)
{
// 先检查是否有重名的目录项,然后分配一个簇
// 文件系统超级块信息
fat32_sb_info_t *fsbi = (fat32_sb_info_t *)parent_inode->sb->private_sb_info;
// 父目录项的inode
// 父目录项的inode的私有信息
struct fat32_inode_info_t *parent_inode_info = (struct fat32_inode_info_t *)parent_inode->private_inode_info;
// ======== todo:检验名称的合法性
// ====== 找一块连续的区域放置新的目录项 =====
int64_t retval = 0;
// ======== 检验名称的合法性
retval = fat32_check_name_available(dest_dEntry->name, dest_dEntry->name_length, 0);
if (retval != 0)
return retval;
if (dest_dEntry->dir_inode != NULL)
return -EEXIST;
struct vfs_index_node_t *inode = (struct vfs_index_node_t *)kmalloc(sizeof(struct vfs_index_node_t), 0);
memset((void *)inode, 0, sizeof(struct vfs_index_node_t));
dest_dEntry->dir_inode = inode;
dest_dEntry->dir_ops = &fat32_dEntry_ops;
struct fat32_inode_info_t *finode = (struct fat32_inode_info_t *)kmalloc(sizeof(struct fat32_inode_info_t), 0);
memset((void *)finode, 0, sizeof(struct fat32_inode_info_t));
inode->attribute = VFS_ATTR_FILE;
inode->file_ops = &fat32_file_ops;
inode->file_size = 0;
inode->sb = parent_inode->sb;
inode->inode_ops = &fat32_inode_ops;
inode->private_inode_info = (void *)finode;
inode->blocks = fsbi->sec_per_clus;
// 计算总共需要多少个目录项
uint32_t cnt_longname = (dEntry->name_length + 25) / 26;
uint32_t cnt_longname = (dest_dEntry->name_length + 25) / 26;
// 默认都是创建长目录项来存储
if (cnt_longname == 0)
cnt_longname = 1;
@ -1020,82 +868,139 @@ int64_t fat32_mkdir(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_
uint64_t tmp_parent_dentry_clus = 0;
// 寻找空闲目录项
struct fat32_Directory_t *empty_fat32_dentry = fat32_find_empty_dentry(parent_inode, cnt_longname + 1, 0, &tmp_dentry_sector, &tmp_parent_dentry_clus, &tmp_dentry_clus_buf_addr);
kdebug("found empty dentry");
// ====== 为新的文件夹分配一个簇 =======
uint32_t new_dir_clus = fat32_find_available_cluster(fsbi);
kdebug("new_dir_clus=%d", new_dir_clus);
fat32_write_FAT_entry(fsbi, new_dir_clus, 0x0ffffff8);
// kdebug("found empty dentry, cnt_longname=%ld", cnt_longname);
// ====== 填写短目录项
memset(empty_fat32_dentry, 0, sizeof(struct fat32_Directory_t));
finode->first_clus = 0;
finode->dEntry_location_clus = tmp_parent_dentry_clus;
finode->dEntry_location_clus_offset = empty_fat32_dentry - (struct fat32_Directory_t *)tmp_dentry_clus_buf_addr;
// ====== 为新的文件分配一个簇 =======
uint32_t new_dir_clus;
if (fat32_alloc_clusters(inode, &new_dir_clus, 1) != 0)
{
int tmp_index = 0;
// kdebug("dEntry->name_length=%d", dEntry->name_length);
for (tmp_index = 0; tmp_index < min(8, dEntry->name_length); ++tmp_index)
{
if (dEntry->name[tmp_index] == '.')
break;
empty_fat32_dentry->DIR_Name[tmp_index] = dEntry->name[tmp_index];
}
// 不满的部分使用0x20填充
while (tmp_index < 11)
{
// kdebug("tmp index = %d", tmp_index);
dEntry->name[tmp_index] = 0x20;
++tmp_index;
}
retval = -ENOSPC;
goto fail;
}
empty_fat32_dentry->DIR_Attr = ATTR_DIRECTORY;
empty_fat32_dentry->DIR_FileSize = fsbi->bytes_per_clus;
empty_fat32_dentry->DIR_FstClusHI = (uint16_t)((new_dir_clus >> 16) & 0x0fff);
empty_fat32_dentry->DIR_FstClusLO = (uint16_t)(new_dir_clus & 0xffff);
// kdebug("new dir clus=%ld", new_dir_clus);
// kdebug("dest_dEntry->name=%s",dest_dEntry->name);
// ====== 填写短目录项
fat32_fill_shortname(dest_dEntry, empty_fat32_dentry, new_dir_clus);
// kdebug("dest_dEntry->name=%s",dest_dEntry->name);
// 计算校验和
uint8_t short_dentry_ChkSum = fat32_ChkSum(empty_fat32_dentry->DIR_Name);
// todo: 填写短目录项中的时间信息
// kdebug("dest_dEntry->name=%s",dest_dEntry->name);
// ======== 填写长目录项
uint32_t current_name_index = 0;
struct fat32_LongDirectory_t *Ldentry = (struct fat32_LongDirectory_t *)(empty_fat32_dentry - 1);
for (int i = 1; i <= cnt_longname; ++i, --Ldentry)
{
Ldentry->LDIR_Ord = i;
for (int j = 0; j < 5; ++j, ++current_name_index)
{
if (current_name_index < dEntry->name_length)
Ldentry->LDIR_Name1[j] = dEntry->name[current_name_index];
else
Ldentry->LDIR_Name1[j] = 0xffff;
}
for (int j = 0; j < 6; ++j, ++current_name_index)
{
if (current_name_index < dEntry->name_length)
Ldentry->LDIR_Name2[j] = dEntry->name[current_name_index];
else
Ldentry->LDIR_Name2[j] = 0xffff;
}
for (int j = 0; j < 2; ++j, ++current_name_index)
{
if (current_name_index < dEntry->name_length)
Ldentry->LDIR_Name3[j] = dEntry->name[current_name_index];
else
Ldentry->LDIR_Name3[j] = 0xffff;
}
Ldentry->LDIR_Attr = ATTR_LONG_NAME;
Ldentry->LDIR_FstClusLO = 0;
Ldentry->LDIR_Type = 0;
Ldentry->LDIR_Chksum = short_dentry_ChkSum;
}
// 最后一个长目录项的ord要|=0x40
Ldentry->LDIR_Ord = 0xe5 | 0x40;
fat32_fill_longname(dest_dEntry, (struct fat32_LongDirectory_t *)(empty_fat32_dentry - 1), short_dentry_ChkSum, cnt_longname);
// ====== 将目录项写回磁盘
// kdebug("tmp_dentry_sector=%ld", tmp_dentry_sector);
ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, tmp_dentry_sector, fsbi->sec_per_clus, tmp_dentry_clus_buf_addr, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
// 注意parent字段需要在调用函数的地方进行设置
// 释放在find empty dentry中动态申请的缓冲区
kfree((void *)tmp_dentry_clus_buf_addr);
return 0;
fail:;
// 释放在find empty dentry中动态申请的缓冲区
kfree((void *)tmp_dentry_clus_buf_addr);
dest_dEntry->dir_inode = NULL;
dest_dEntry->dir_ops = NULL;
kfree(finode);
kfree(inode);
return retval;
}
/**
* @brief
* @param inode inode
* @param dEntry dentry
* @param mode mode
*/
int64_t fat32_mkdir(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_t *dEntry, int mode)
{
int64_t retval = 0;
// 文件系统超级块信息
fat32_sb_info_t *fsbi = (fat32_sb_info_t *)parent_inode->sb->private_sb_info;
// 父目录项的inode私有信息
struct fat32_inode_info_t *parent_inode_info = (struct fat32_inode_info_t *)parent_inode->private_inode_info;
// ======== 检验名称的合法性
retval = fat32_check_name_available(dEntry->name, dEntry->name_length, 0);
if (retval != 0)
return retval;
// ====== 找一块连续的区域放置新的目录项 =====
// 计算总共需要多少个目录项
uint32_t cnt_longname = (dEntry->name_length + 25) / 26;
// 默认都是创建长目录项来存储
if (cnt_longname == 0)
cnt_longname = 1;
// 空闲dentry所在的扇区号
uint32_t tmp_dentry_sector = 0;
// 空闲dentry所在的缓冲区的基地址
uint64_t tmp_dentry_clus_buf_addr = 0;
uint64_t tmp_parent_dentry_clus = 0;
// 寻找空闲目录项
struct fat32_Directory_t *empty_fat32_dentry = fat32_find_empty_dentry(parent_inode, cnt_longname + 1, 0, &tmp_dentry_sector, &tmp_parent_dentry_clus, &tmp_dentry_clus_buf_addr);
// ====== 初始化inode =======
struct vfs_index_node_t *inode = (struct vfs_index_node_t *)kmalloc(sizeof(struct vfs_index_node_t), 0);
memset(inode, 0, sizeof(struct vfs_index_node_t));
inode->attribute = VFS_ATTR_DIR;
inode->blocks = fsbi->sec_per_clus;
inode->file_ops = &fat32_file_ops;
inode->file_size = 0;
inode->inode_ops = &fat32_inode_ops;
inode->sb = parent_inode->sb;
// ===== 初始化inode的文件系统私有信息 ====
inode->private_inode_info = (fat32_inode_info_t *)kmalloc(sizeof(fat32_inode_info_t), 0);
memset(inode->private_inode_info, 0, sizeof(fat32_inode_info_t));
fat32_inode_info_t *p = (fat32_inode_info_t *)inode->private_inode_info;
p->first_clus = 0;
p->dEntry_location_clus = tmp_parent_dentry_clus;
p->dEntry_location_clus_offset = empty_fat32_dentry - (struct fat32_Directory_t *)tmp_dentry_clus_buf_addr;
// kdebug(" p->dEntry_location_clus_offset=%d", p->dEntry_location_clus_offset);
// todo: 填写完全fat32_inode_info的信息
// 初始化dentry信息
list_init(&dEntry->child_node_list);
list_init(&dEntry->subdirs_list);
dEntry->dir_ops = &fat32_dEntry_ops;
dEntry->dir_inode = inode;
// ====== 为新的文件夹分配一个簇 =======
uint32_t new_dir_clus;
if (fat32_alloc_clusters(inode, &new_dir_clus, 1) != 0)
{
retval = -ENOSPC;
goto fail;
}
// kdebug("new dir clus=%ld", new_dir_clus);
// ====== 填写短目录项
fat32_fill_shortname(dEntry, empty_fat32_dentry, new_dir_clus);
// 计算校验和
uint8_t short_dentry_ChkSum = fat32_ChkSum(empty_fat32_dentry->DIR_Name);
// ======== 填写长目录项
fat32_fill_longname(dEntry, (struct fat32_LongDirectory_t *)(empty_fat32_dentry - 1), short_dentry_ChkSum, cnt_longname);
// ====== 将目录项写回磁盘
// kdebug("tmp_dentry_sector=%ld", tmp_dentry_sector);
ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, tmp_dentry_sector, fsbi->sec_per_clus, tmp_dentry_clus_buf_addr, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
// ====== 初始化新的文件夹的目录项 =====
{
// kdebug("to create dot and dot dot.");
void *buf = kmalloc(fsbi->bytes_per_clus, 0);
struct fat32_Directory_t *new_dir_dentries = (struct fat32_Directory_t *)buf;
memset((void *)new_dir_dentries, 0, fsbi->bytes_per_clus);
@ -1106,7 +1011,7 @@ int64_t fat32_mkdir(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_
new_dir_dentries->DIR_Name[0] = '.';
for (int i = 1; i < 11; ++i)
new_dir_dentries->DIR_Name[i] = 0x20;
new_dir_dentries->DIR_FstClusHI = empty_fat32_dentry->DIR_FstClusHI;
new_dir_dentries->DIR_FstClusLO = empty_fat32_dentry->DIR_FstClusLO;
@ -1124,31 +1029,9 @@ int64_t fat32_mkdir(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_
// 写入磁盘
uint64_t sector = fsbi->first_data_sector + (new_dir_clus - 2) * fsbi->sec_per_clus;
// kdebug("add dot and dot dot: sector=%ld", sector);
ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
}
// ===== 初始化inode ====
struct vfs_index_node_t *finode = (struct vfs_index_node_t *)kmalloc(sizeof(struct vfs_index_node_t), 0);
memset(finode, 0, sizeof(struct vfs_index_node_t));
finode->attribute = VFS_ATTR_DIR;
finode->blocks = fsbi->sec_per_clus;
finode->file_ops = &fat32_file_ops;
finode->file_size = fsbi->bytes_per_clus;
finode->inode_ops = &fat32_inode_ops;
finode->sb = parent_inode->sb;
finode->private_inode_info = (fat32_inode_info_t *)kmalloc(sizeof(fat32_inode_info_t), 0);
memset(finode->private_inode_info, 0, sizeof(fat32_inode_info_t));
fat32_inode_info_t *p = (fat32_inode_info_t *)finode->private_inode_info;
p->first_clus = new_dir_clus;
p->dEntry_location_clus = tmp_parent_dentry_clus;
p->dEntry_location_clus_offset = empty_fat32_dentry - (struct fat32_Directory_t *)tmp_dentry_clus_buf_addr;
// todo: 填写fat32_inode_info的信息
// 初始化dentry信息
list_init(&dEntry->child_node_list);
list_init(&dEntry->subdirs_list);
dEntry->dir_ops = &fat32_dEntry_ops;
dEntry->dir_inode = finode;
// 注意parent字段需要在调用函数的地方进行设置
// 注意需要将当前dentry加入父目录的subdirs_list
@ -1157,6 +1040,10 @@ int64_t fat32_mkdir(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_
kfree((void *)tmp_dentry_clus_buf_addr);
return 0;
fail:;
// 释放在find empty dentry中动态申请的缓冲区
kfree((void *)tmp_dentry_clus_buf_addr);
return retval;
}
// todo: rmdir

View File

@ -155,7 +155,7 @@ typedef struct fat32_partition_info_t fat32_sb_info_t;
struct fat32_inode_info_t
{
uint64_t first_clus; // 文件的起始簇号
uint32_t first_clus; // 文件的起始簇号
uint64_t dEntry_location_clus; // fat entry的起始簇号 dEntry struct in cluster (0 is root, 1 is invalid)
uint64_t dEntry_location_clus_offset; // fat entry在起始簇中的偏移量(是第几个entry) dEntry struct offset in cluster
@ -176,7 +176,6 @@ typedef struct fat32_inode_info_t fat32_inode_info_t;
*/
struct vfs_superblock_t *fat32_register_partition(uint8_t ahci_ctrl_num, uint8_t ahci_port_num, uint8_t part_num);
/**
* @brief fat32文件系统的超级块
*
@ -187,7 +186,13 @@ struct vfs_superblock_t *fat32_register_partition(uint8_t ahci_ctrl_num, uint8_t
*/
struct vfs_superblock_t *fat32_read_superblock(void *DPTE, uint8_t DPT_type, void *buf, int8_t ahci_ctrl_num, int8_t ahci_port_num, int8_t part_num);
long fat32_create(struct vfs_index_node_t *inode, struct vfs_dir_entry_t *dentry, int mode);
/**
* @brief
* @param parent_inode inode结构体
* @param dest_dEntry dentry
* @param mode
*/
long fat32_create(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_t *dest_dEntry, int mode);
void fat32_init();

View File

@ -0,0 +1,414 @@
#include "fat_ent.h"
#include <driver/disk/ahci/ahci.h>
#include <common/errno.h>
#include <mm/slab.h>
static const char unavailable_character_in_short_name[] = {0x22, 0x2a, 0x2b, 0x2c, 0x2e, 0x2f, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x5b, 0x5c, 0x5d, 0x7c};
/**
* @brief
*
* @param inode inode
* @param clusters
* @param num_clusters
* @return int
*/
int fat32_alloc_clusters(struct vfs_index_node_t *inode, uint32_t *clusters, int32_t num_clusters)
{
int retval = 0;
fat32_sb_info_t *fsbi = (fat32_sb_info_t *)inode->sb->private_sb_info;
struct fat32_inode_info_t *finode = (struct fat32_inode_info_t *)inode->private_inode_info;
uint64_t sec_per_fat = fsbi->sec_per_FAT;
// todo: 对alloc的过程加锁
// 申请1扇区的缓冲区
uint32_t *buf = (uint32_t *)kmalloc(fsbi->bytes_per_sec, 0);
int ent_per_sec = (fsbi->bytes_per_sec >> 2);
int clus_idx = 0;
for (int i = 0; i < sec_per_fat; ++i)
{
if (clus_idx >= num_clusters)
goto done;
memset(buf, 0, fsbi->bytes_per_sec);
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + i, 1, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
// 依次检查簇是否空闲
for (int j = 0; j < ent_per_sec; ++j)
{
if (clus_idx >= num_clusters)
goto done;
// 找到空闲簇
if ((buf[j] & 0x0fffffff) == 0)
{
// kdebug("clus[%d] = %d", clus_idx, i * ent_per_sec + j);
clusters[clus_idx] = i * ent_per_sec + j;
++clus_idx;
}
}
}
// 空间不足
retval = -ENOSPC;
done:;
kfree(buf);
if (retval == 0) // 成功
{
int cluster, idx;
if (finode->first_clus == 0)
{
// 空文件
finode->first_clus = clusters[0];
cluster = finode->first_clus;
// 写入inode到磁盘
inode->sb->sb_ops->write_inode(inode);
idx = 1;
}
else
{
// todo: 跳转到文件当前的最后一个簇
idx = 0;
int tmp_clus = finode->first_clus;
cluster = tmp_clus;
while (true)
{
tmp_clus = fat32_read_FAT_entry(fsbi, cluster);
if (tmp_clus <= 0x0ffffff7)
cluster = tmp_clus;
else
break;
}
}
// 写入fat表
for (int i = idx; i < num_clusters; ++i)
{
// kdebug("write cluster i=%d : cluster=%d, value= %d", i, cluster, clusters[i]);
fat32_write_FAT_entry(fsbi, cluster, clusters[i]);
cluster = clusters[i];
}
fat32_write_FAT_entry(fsbi, cluster, 0x0ffffff8);
return 0;
}
else // 出现错误
{
kwarn("err in alloc clusters");
if (clus_idx < num_clusters)
fat32_free_clusters(inode, clusters[0]);
return retval;
}
return 0;
}
/**
* @brief inode的cluster开始的所有簇
*
* @param inode inode
* @param cluster
* @return int
*/
int fat32_free_clusters(struct vfs_index_node_t *inode, int32_t cluster)
{
// todo: 释放簇
return 0;
}
/**
* @brief FAT表项
*
* @param fsbi fat32超级块私有信息结构体
* @param cluster
* @return uint32_t
*/
uint32_t fat32_read_FAT_entry(fat32_sb_info_t *fsbi, uint32_t cluster)
{
// 计算每个扇区内含有的FAT表项数
// FAT每项4bytes
uint32_t fat_ent_per_sec = (fsbi->bytes_per_sec >> 2); // 该值应为2的n次幂
uint32_t buf[256];
memset(buf, 0, fsbi->bytes_per_sec);
// 读取一个sector的数据
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
(uint64_t)&buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
// 返回下一个fat表项的值也就是下一个cluster
return buf[cluster & (fat_ent_per_sec - 1)] & 0x0fffffff;
}
/**
* @brief FAT表项
*
* @param fsbi fat32超级块私有信息结构体
* @param cluster
* @param value fat表项的值
* @return uint32_t errcode
*/
uint32_t fat32_write_FAT_entry(fat32_sb_info_t *fsbi, uint32_t cluster, uint32_t value)
{
// 计算每个扇区内含有的FAT表项数
// FAT每项4bytes
uint32_t fat_ent_per_sec = (fsbi->bytes_per_sec >> 2); // 该值应为2的n次幂
uint32_t *buf = kmalloc(fsbi->bytes_per_sec, 0);
memset(buf, 0, fsbi->bytes_per_sec);
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
(uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
buf[cluster & (fat_ent_per_sec - 1)] = (buf[cluster & (fat_ent_per_sec - 1)] & 0xf0000000) | (value & 0x0fffffff);
// 向FAT1和FAT2写入数据
ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
(uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, fsbi->FAT2_base_sector + (cluster / fat_ent_per_sec), 1,
(uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
kfree(buf);
return 0;
}
/**
* @brief inode的目录项簇中num个空的目录项
*
* @param parent_inode inode
* @param num
* @param mode
* @param res_sector
* @param res_cluster
* @param res_data_buf_base
* @return struct fat32_Directory_t* entry的指针num个
*/
struct fat32_Directory_t *fat32_find_empty_dentry(struct vfs_index_node_t *parent_inode, uint32_t num, uint32_t mode, uint32_t *res_sector, uint64_t *res_cluster, uint64_t *res_data_buf_base)
{
// kdebug("find empty_dentry");
struct fat32_inode_info_t *finode = (struct fat32_inode_info_t *)parent_inode->private_inode_info;
fat32_sb_info_t *fsbi = (fat32_sb_info_t *)parent_inode->sb->private_sb_info;
uint8_t *buf = kmalloc(fsbi->bytes_per_clus, 0);
memset(buf, 0, fsbi->bytes_per_clus);
// 计算父目录项的起始簇号
uint32_t cluster = finode->first_clus;
struct fat32_Directory_t *tmp_dEntry = NULL;
// 指向最终的有用的dentry的指针
struct fat32_Directory_t *result_dEntry = NULL;
while (true)
{
// 计算父目录项的起始LBA扇区号
uint64_t sector = fsbi->first_data_sector + (cluster - 2) * fsbi->sec_per_clus;
// 读取父目录项的起始簇数据
ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
tmp_dEntry = (struct fat32_Directory_t *)buf;
// 计数连续的空目录项
uint32_t count_continuity = 0;
// 查找连续num个空闲目录项
for (int i = 0; (i < fsbi->bytes_per_clus) && count_continuity < num; i += 32, ++tmp_dEntry)
{
if (!(tmp_dEntry->DIR_Name[0] == 0xe5 || tmp_dEntry->DIR_Name[0] == 0x00))
{
count_continuity = 0;
continue;
}
if (count_continuity == 0)
result_dEntry = tmp_dEntry;
++count_continuity;
}
// 成功查找到符合要求的目录项
if (count_continuity == num)
{
result_dEntry += (num - 1);
*res_sector = sector;
*res_data_buf_base = (uint64_t)buf;
*res_cluster = cluster;
return result_dEntry;
}
// 当前簇没有发现符合条件的空闲目录项,寻找下一个簇
uint64_t old_cluster = cluster;
cluster = fat32_read_FAT_entry(fsbi, cluster);
if (cluster >= 0x0ffffff7) // 寻找完父目录的所有簇,都没有找到符合要求的空目录项
{
// 新增一个簇
if (fat32_alloc_clusters(parent_inode, &cluster, 1) != 0)
{
kerror("Cannot allocate a new cluster!");
while (1)
pause();
}
// 将这个新的簇清空
sector = fsbi->first_data_sector + (cluster - 2) * fsbi->sec_per_clus;
void *tmp_buf = kmalloc(fsbi->bytes_per_clus, 0);
memset(tmp_buf, 0, fsbi->bytes_per_clus);
ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)tmp_buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
kfree(tmp_buf);
}
}
}
/**
* @brief
*
* @param name
* @param namelen
* @param reserved
* @return int 0
*/
int fat32_check_name_available(const char *name, int namelen, int8_t reserved)
{
if (namelen > 255 || namelen <= 0)
return -ENAMETOOLONG;
// 首个字符不能是空格或者'.'
if (name[0] == 0x20 || name[0] == '.')
return -EINVAL;
return 0;
}
/**
* @brief
*
* @param c
* @param index
* @return true
* @return false
*/
bool fat32_check_char_available_in_short_name(const char c, int index)
{
// todo: 严格按照fat规范完善合法性检查功能
if (index == 0)
{
if (c < 0x20)
{
if (c != 0x05)
return false;
return true;
}
}
for (int i = 0; i < sizeof(unavailable_character_in_short_name) / sizeof(char); ++i)
{
if (c == unavailable_character_in_short_name[i])
return false;
}
return true;
}
/**
* @brief
*
* @param dEntry dentry
* @param target dentry对应的短目录项
* @param cluster /
*/
void fat32_fill_shortname(struct vfs_dir_entry_t *dEntry, struct fat32_Directory_t *target, uint32_t cluster)
{
memset(target, 0, sizeof(struct fat32_Directory_t));
{
int tmp_index = 0;
// kdebug("dEntry->name_length=%d", dEntry->name_length);
for (tmp_index = 0; tmp_index < min(8, dEntry->name_length); ++tmp_index)
{
if (dEntry->name[tmp_index] == '.')
break;
if (fat32_check_char_available_in_short_name(dEntry->name[tmp_index], tmp_index))
target->DIR_Name[tmp_index] = dEntry->name[tmp_index];
else
target->DIR_Name[tmp_index] = 0x20;
}
// 不满的部分使用0x20填充
while (tmp_index < 8)
{
// kdebug("tmp index = %d", tmp_index);
target->DIR_Name[tmp_index] = 0x20;
++tmp_index;
}
if (dEntry->dir_inode->attribute & VFS_ATTR_DIR)
{
while (tmp_index < 11)
{
// kdebug("tmp index = %d", tmp_index);
target->DIR_Name[tmp_index] = 0x20;
++tmp_index;
}
}
else
{
for(int j = 8;j<11;++j)
{
target->DIR_Name[j] = 'a';
}
}
}
struct vfs_index_node_t *inode = dEntry->dir_inode;
target->DIR_Attr = 0;
if (inode->attribute & VFS_ATTR_DIR)
target->DIR_Attr |= ATTR_DIRECTORY;
target->DIR_FileSize = dEntry->dir_inode->file_size;
target->DIR_FstClusHI = (uint16_t)((cluster >> 16) & 0x0fff);
target->DIR_FstClusLO = (uint16_t)(cluster & 0xffff);
// todo: 填写短目录项中的时间信息
}
/**
* @brief
*
* @param dEntry dentry
* @param target
* @param checksum
* @param cnt_longname
*/
void fat32_fill_longname(struct vfs_dir_entry_t *dEntry, struct fat32_LongDirectory_t *target, uint8_t checksum, uint32_t cnt_longname)
{
uint32_t current_name_index = 0;
struct fat32_LongDirectory_t *Ldentry = (struct fat32_LongDirectory_t *)(target + 1);
// kdebug("filling long name, name=%s, namelen=%d", dEntry->name, dEntry->name_length);
for (int i = 1; i <= cnt_longname; ++i)
{
--Ldentry;
Ldentry->LDIR_Ord = i;
for (int j = 0; j < 5; ++j, ++current_name_index)
{
if (current_name_index < dEntry->name_length)
Ldentry->LDIR_Name1[j] = dEntry->name[current_name_index];
else
Ldentry->LDIR_Name1[j] = 0xffff;
}
for (int j = 0; j < 6; ++j, ++current_name_index)
{
if (current_name_index < dEntry->name_length)
Ldentry->LDIR_Name2[j] = dEntry->name[current_name_index];
else
Ldentry->LDIR_Name2[j] = 0xffff;
}
for (int j = 0; j < 2; ++j, ++current_name_index)
{
if (current_name_index < dEntry->name_length)
Ldentry->LDIR_Name3[j] = dEntry->name[current_name_index];
else
Ldentry->LDIR_Name3[j] = 0xffff;
}
Ldentry->LDIR_Attr = ATTR_LONG_NAME;
Ldentry->LDIR_FstClusLO = 0;
Ldentry->LDIR_Type = 0;
Ldentry->LDIR_Chksum = checksum;
}
// 最后一个长目录项的ord要|=0x40
Ldentry->LDIR_Ord |= 0x40;
}

View File

@ -0,0 +1,95 @@
#pragma once
#include "fat32.h"
#include <filesystem/VFS/VFS.h>
#include <stdbool.h>
/**
* @brief
*
* @param inode inode
* @param clusters
* @param num_clusters
* @return int
*/
int fat32_alloc_clusters(struct vfs_index_node_t *inode, uint32_t *clusters, int32_t num_clusters);
/**
* @brief inode的cluster开始的所有簇
*
* @param inode inode
* @param cluster
* @return int
*/
int fat32_free_clusters(struct vfs_index_node_t *inode, int32_t cluster);
/**
* @brief FAT表项
*
* @param fsbi fat32超级块私有信息结构体
* @param cluster
* @return uint32_t
*/
uint32_t fat32_read_FAT_entry(fat32_sb_info_t *fsbi, uint32_t cluster);
/**
* @brief FAT表项
*
* @param fsbi fat32超级块私有信息结构体
* @param cluster
* @param value fat表项的值
* @return uint32_t errcode
*/
uint32_t fat32_write_FAT_entry(fat32_sb_info_t *fsbi, uint32_t cluster, uint32_t value);
/**
* @brief inode的目录项簇中num个空的目录项
*
* @param parent_inode inode
* @param num
* @param mode
* @param res_sector
* @param res_cluster
* @param res_data_buf_base
* @return struct fat32_Directory_t* entry的指针num个
*/
struct fat32_Directory_t *fat32_find_empty_dentry(struct vfs_index_node_t *parent_inode, uint32_t num, uint32_t mode, uint32_t *res_sector, uint64_t *res_cluster, uint64_t *res_data_buf_base);
/**
* @brief
*
* @param name
* @param namelen
* @param reserved
* @return int 0
*/
int fat32_check_name_available(const char *name, int namelen, int8_t reserved);
/**
* @brief
*
* @param c
* @param index
* @return true
* @return false
*/
bool fat32_check_char_available_in_short_name(const char c, int index);
/**
* @brief
*
* @param dEntry dentry
* @param target dentry对应的短目录项
* @param cluster /
*/
void fat32_fill_shortname(struct vfs_dir_entry_t *dEntry, struct fat32_Directory_t *target, uint32_t cluster);
/**
* @brief
*
* @param dEntry dentry
* @param target
* @param checksum
* @param cnt_longname
*/
void fat32_fill_longname(struct vfs_dir_entry_t *dEntry, struct fat32_LongDirectory_t *target, uint8_t checksum, uint32_t cnt_longname);

View File

@ -108,7 +108,6 @@ ul sys_put_string(struct pt_regs *regs)
uint64_t sys_open(struct pt_regs *regs)
{
char *filename = (char *)(regs->r8);
int flags = (int)(regs->r9);
// kdebug("filename=%s", filename);
@ -131,6 +130,12 @@ uint64_t sys_open(struct pt_regs *regs)
memset(path, 0, path_len);
strncpy_from_user(path, filename, path_len);
// 去除末尾的 '/'
if (path_len >= 2 && path[path_len - 2] == '/')
{
path[path_len - 2] = '\0';
--path_len;
}
// 寻找文件
struct vfs_dir_entry_t *dentry = vfs_path_walk(path, 0);
@ -139,7 +144,61 @@ uint64_t sys_open(struct pt_regs *regs)
// printk_color(ORANGE, BLACK, "Found %s\nDIR_FstClus:%#018lx\tDIR_FileSize:%#018lx\n", path, ((struct fat32_inode_info_t *)(dentry->dir_inode->private_inode_info))->first_clus, dentry->dir_inode->file_size);
// else
// printk_color(ORANGE, BLACK, "Can`t find file\n");
// kdebug("flags=%#018lx", flags);
if (dentry == NULL && flags & O_CREAT)
{
// 先找到倒数第二级目录
int tmp_index = -1;
for (int i = path_len - 1; i >= 0; --i)
{
if (path[i] == '/')
{
tmp_index = i;
break;
}
}
struct vfs_dir_entry_t *parent_dentry = NULL;
// kdebug("tmp_index=%d", tmp_index);
if (tmp_index > 0)
{
path[tmp_index] = '\0';
dentry = vfs_path_walk(path, 0);
if (dentry == NULL)
{
kfree(path);
return -ENOENT;
}
parent_dentry = dentry;
}
else
parent_dentry = vfs_root_sb->root;
// 创建新的文件
dentry = (struct vfs_dir_entry_t *)kmalloc(sizeof(struct vfs_dir_entry_t), 0);
memset(dentry, 0, sizeof(struct vfs_dir_entry_t));
dentry->name_length = path_len - tmp_index - 1;
dentry->name = (char *)kmalloc(dentry->name_length, 0);
memset(dentry->name, 0, dentry->name_length);
strncpy(dentry->name, path + tmp_index + 1, dentry->name_length);
// kdebug("to create new file:%s namelen=%d", dentry->name, dentry->name_length)
dentry->parent = parent_dentry;
uint64_t retval = parent_dentry->dir_inode->inode_ops->create(parent_dentry->dir_inode, dentry, 0);
if (retval != 0)
{
kfree(dentry->name);
kfree(dentry);
kfree(path);
return retval;
}
list_init(&dentry->child_node_list);
list_init(&dentry->subdirs_list);
list_add(&parent_dentry->subdirs_list, &dentry->child_node_list);
// kdebug("created.");
}
kfree(path);
if (dentry == NULL)
return -ENOENT;
@ -148,18 +207,21 @@ uint64_t sys_open(struct pt_regs *regs)
if ((flags & O_DIRECTORY) && (dentry->dir_inode->attribute != VFS_ATTR_DIR))
return -ENOTDIR;
// 要找的目标是文件夹
if ((flags & O_DIRECTORY) && dentry->dir_inode->attribute == VFS_ATTR_DIR)
return -EISDIR;
// // 要找的目标是文件夹
// if ((flags & O_DIRECTORY) && dentry->dir_inode->attribute == VFS_ATTR_DIR)
// return -EISDIR;
// todo: 引入devfs后删除这段代码
// 暂时遇到设备文件的话就将其first clus设置为特定值
if (path_len >= 5 && filename[0] == '/' && filename[1] == 'd' && filename[2] == 'e' && filename[3] == 'v' && filename[4] == '/')
{
// 对于fat32文件系统上面的设备文件设置其起始扇区
((struct fat32_inode_info_t *)(dentry->dir_inode->private_inode_info))->first_clus |= 0xf0000000;
dentry->dir_inode->sb->sb_ops->write_inode(dentry->dir_inode);
dentry->dir_inode->attribute |= VFS_ATTR_DEVICE;
if (dentry->dir_inode->attribute & VFS_ATTR_FILE)
{
// 对于fat32文件系统上面的设备文件设置其起始扇区
((struct fat32_inode_info_t *)(dentry->dir_inode->private_inode_info))->first_clus |= 0xf0000000;
dentry->dir_inode->sb->sb_ops->write_inode(dentry->dir_inode);
dentry->dir_inode->attribute |= VFS_ATTR_DEVICE;
}
}
// 创建文件描述符
@ -404,12 +466,7 @@ uint64_t sys_brk(struct pt_regs *regs)
else
offset = -(int64_t)(current_pcb->mm->brk_end - new_brk);
/*
if (offset < 0)
{
kdebug("decrease brk, offset = %#010lx", (uint64_t)(-offset));
}
*/
new_brk = mm_do_brk(current_pcb->mm->brk_end, offset); // 扩展堆内存空间
@ -517,14 +574,14 @@ uint64_t sys_chdir(struct pt_regs *regs)
}
else
strncpy(path, dest_path, dest_path_len + 1);
// kdebug("chdir: path = %s", path);
struct vfs_dir_entry_t *dentry = vfs_path_walk(path, 0);
kfree(path);
if (dentry == NULL)
return -ENOENT;
// kdebug("dentry->name=%s, namelen=%d", dentry->name, dentry->name_length);
// 目标不是目录
if (dentry->dir_inode->attribute != VFS_ATTR_DIR)
return -ENOTDIR;

1
run.sh
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@ -91,6 +91,7 @@ fi
# 拷贝应用程序到硬盘
cd tools
bash m*
sudo mkdir -p ${root_folder}/bin/disk_mount
sudo cp ${root_folder}/bin/user/shell.elf ${root_folder}/bin/disk_mount
sudo cp ${root_folder}/bin/user/about.elf ${root_folder}/bin/disk_mount
sudo mkdir ${root_folder}/bin/disk_mount/dev

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@ -5,6 +5,12 @@ qemu-img create -f raw disk.img 16M
# 按顺序输入,并且,每次输入完成后要按下回车)
fdisk disk.img
echo "Successfully created disk image, please make a FAT32 filesystem on it"
sudo mkdir -p ../bin
sudo cp ./disk.img ../bin/
LOOP_DEVICE=$(sudo losetup -f --show -P disk.img) \
|| exit 1
echo ${LOOP_DEVICE}p1
sudo mkfs.vfat -F 32 ${LOOP_DEVICE}p1
sudo losetup -d ${LOOP_DEVICE}
echo "Successfully created disk image."
mkdir -p ../bin
mv ./disk.img ../bin/

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@ -2,7 +2,7 @@ LOOP_DEVICE=$(sudo losetup -f --show -P ../bin/disk.img) \
|| exit 1
echo ${LOOP_DEVICE}p1
sudo mkfs.vfat -F 32 ${LOOP_DEVICE}p1
mkdir -p ../bin/disk_mount/
sudo mount ${LOOP_DEVICE}p1 ../bin/disk_mount/
lsblk

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@ -10,7 +10,7 @@
#include <libc/fcntl.h>
#include <libc/dirent.h>
#include <libc/sys/wait.h>
#include <libc/sys/stat.h>
#include "cmd_help.h"
// 当前工作目录在main_loop中初始化
@ -181,7 +181,7 @@ int shell_cmd_cd(int argc, char **argv)
goto fail;
; // 出错则直接忽略
}
else
else // ======进入相对路径=====
{
int dest_offset = 0;
if (dest_len > 2)
@ -191,7 +191,7 @@ int shell_cmd_cd(int argc, char **argv)
}
int new_len = current_dir_len + dest_len - dest_offset;
// ======进入相对路径=====
if (new_len >= SHELL_CWD_MAX_SIZE - 1)
{
printf("ERROR: Path too long!\n");
@ -210,7 +210,8 @@ int shell_cmd_cd(int argc, char **argv)
if (chdir(new_path) == 0) // 成功切换目录
{
free(shell_current_path);
new_path[new_len] = '\0';
// printf("new_path=%s, newlen= %d\n", new_path, new_len);
new_path[new_len + 1] = '\0';
shell_current_path = new_path;
goto done;
}
@ -329,8 +330,30 @@ int shell_cmd_cat(int argc, char **argv)
* @param argv
* @return int
*/
// todo:
int shell_cmd_touch(int argc, char **argv) {}
int shell_cmd_touch(int argc, char **argv)
{
int path_len = 0;
char *file_path;
if (argv[1][0] == '/')
file_path = argv[1];
else
file_path = get_target_filepath(argv[1], &path_len);
// 打开文件
int fd = open(file_path, O_CREAT);
switch (fd)
{
case -ENOENT:
put_string("Parent dir not exists.\n", COLOR_RED, COLOR_BLACK);
break;
default:
break;
}
close(fd);
if (argv != NULL)
free(argv);
}
/**
* @brief
@ -349,8 +372,24 @@ int shell_cmd_rm(int argc, char **argv) {}
* @param argv
* @return int
*/
// todo:
int shell_cmd_mkdir(int argc, char **argv) {}
int shell_cmd_mkdir(int argc, char **argv)
{
int result_path_len = -1;
const char *full_path = NULL;
if (argv[1][0] == '/')
full_path = argv[1];
else
{
full_path = get_target_filepath(argv[1], &result_path_len);
}
printf("mkdir: full_path = %s\n", full_path);
int retval = mkdir(full_path, 0);
if (argv != NULL)
free(argv);
return retval;
}
/**
* @brief
@ -406,13 +445,12 @@ int shell_cmd_about(int argc, char **argv)
char **aav;
unsigned char input_buffer[INPUT_BUFFER_SIZE] = {0};
strcpy(input_buffer, "exec /about.elf\0");
parse_command(input_buffer, &aac, &aav);
shell_cmd_exec(aac, aav);
}
/**

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@ -73,9 +73,9 @@ int main()
int kb_fd = open(kb_file_path, 0);
// printf("keyboard fd = %d\n", kb_fd);
print_ascii_logo();
printf("before mkdir\n");
mkdir("/aaac", 0);
printf("after mkdir\n");
// printf("before mkdir\n");
// mkdir("/aaac", 0);
// printf("after mkdir\n");
main_loop(kb_fd);
while (1)
;

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@ -11,5 +11,5 @@
*/
int open(const char *path, int options, ...)
{
return syscall_invoke(SYS_OPEN, (uint64_t)path, 0, 0, 0, 0, 0, 0, 0);
return syscall_invoke(SYS_OPEN, (uint64_t)path, options, 0, 0, 0, 0, 0, 0);
}