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Code Issues Releases Wiki Activity

Devfs初步实现 (#41)

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* new: 在devfs中使用键盘文件（仍存在bug）

* new:支持dev目录下的readdir
This commit is contained in:
login
2022-09-07 23:27:27 +08:00
committed by GitHub
parent 86a5f25e07
commit 7d44599447
16 changed files with 683 additions and 215 deletions
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183
kernel/syscall/syscall.c
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@ -9,7 +9,6 @@
#include <common/string.h>
#include <filesystem/fat32/fat32.h>
#include <filesystem/VFS/VFS.h>
#include <driver/keyboard/ps2_keyboard.h>
#include <process/process.h>
#include <time/sleep.h>
@ -19,6 +18,7 @@ extern void syscall_int(void);
extern uint64_t sys_clock(struct pt_regs *regs);
extern uint64_t sys_mstat(struct pt_regs *regs);
extern uint64_t sys_open(struct pt_regs *regs);
/**
* @brief 导出系统调用处理函数的符号
@ -121,186 +121,7 @@ ul sys_put_string(struct pt_regs *regs)
return 0;
}
uint64_t sys_open(struct pt_regs *regs)
{
char *filename = (char *)(regs->r8);
int flags = (int)(regs->r9);
// kdebug("filename=%s", filename);
long path_len = strnlen_user(filename, PAGE_4K_SIZE) + 1;
if (path_len <= 0) // 地址空间错误
{
return -EFAULT;
}
else if (path_len >= PAGE_4K_SIZE) // 名称过长
{
return -ENAMETOOLONG;
}
// 为待拷贝文件路径字符串分配内存空间
char *path = (char *)kmalloc(path_len, 0);
if (path == NULL)
return -ENOMEM;
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);
// if (dentry != NULL)
// 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;
// 要求打开文件夹而目标不是文件夹
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;
// 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] == '/')
{
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
struct vfs_file_t *file_ptr = (struct vfs_file_t *)kmalloc(sizeof(struct vfs_file_t), 0);
memset(file_ptr, 0, sizeof(struct vfs_file_t));
int errcode = -1;
file_ptr->dEntry = dentry;
file_ptr->mode = flags;
// todo: 接入devfs
// 特判一下是否为键盘文件
if (dentry->dir_inode->attribute & VFS_ATTR_DEVICE)
{
file_ptr->file_ops = &ps2_keyboard_fops; // 如果是设备文件，暂时认为它是键盘文件
}
else
file_ptr->file_ops = dentry->dir_inode->file_ops;
// 如果文件系统实现了打开文件的函数
if (file_ptr->file_ops && file_ptr->file_ops->open)
errcode = file_ptr->file_ops->open(dentry->dir_inode, file_ptr);
if (errcode != VFS_SUCCESS)
{
kfree(file_ptr);
return -EFAULT;
}
if (file_ptr->mode & O_TRUNC) // 清空文件
file_ptr->dEntry->dir_inode->file_size = 0;
if (file_ptr->mode & O_APPEND)
file_ptr->position = file_ptr->dEntry->dir_inode->file_size;
else
file_ptr->position = 0;
struct vfs_file_t **f = current_pcb->fds;
int fd_num = -1;
// 在指针数组中寻找空位
// todo: 当pcb中的指针数组改为动态指针数组之后，需要更改这里（目前还是静态指针数组）
for (int i = 0; i < PROC_MAX_FD_NUM; ++i)
{
if (f[i] == NULL) // 找到指针数组中的空位
{
fd_num = i;
break;
}
}
// 指针数组没有空位了
if (fd_num == -1)
{
kfree(file_ptr);
return -EMFILE;
}
// 保存文件描述符
f[fd_num] = file_ptr;
return fd_num;
}
/**
* @brief 关闭文件系统调用
@ -624,7 +445,7 @@ uint64_t sys_getdents(struct pt_regs *regs)
uint64_t retval = 0;
if (filp->file_ops && filp->file_ops->readdir)
retval = filp->file_ops->readdir(filp, dirent, &vfs_fill_dentry);
retval = filp->file_ops->readdir(filp, dirent, &vfs_fill_dirent);
return retval;
}