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* 对mkdir加锁 * 给mkdir和do_open的dentry加锁 * 对加锁进行了修改 * modified * bugfix: 修复一些死锁及空指针的错误 Co-authored-by: longjin <longjin@RinGoTek.cn>
279 lines
8.1 KiB
C
279 lines
8.1 KiB
C
/**
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* @file VFS.h
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* @author fslongjin (longjin@RinGoTek.cn)
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* @brief 虚拟文件系统
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* @version 0.1
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* @date 2022-04-20
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*
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* @copyright Copyright (c) 2022
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*
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*/
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#pragma once
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#include <common/blk_types.h>
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#include <common/fcntl.h>
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#include <common/glib.h>
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#include <common/lockref.h>
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#include <mm/slab.h>
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extern struct vfs_superblock_t *vfs_root_sb;
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#define VFS_DPT_MBR 0 // MBR分区表
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#define VFS_DPT_GPT 1 // GPT分区表
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#define VFS_MAX_PATHLEN 1024
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/**
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* @brief inode的属性
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*
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*/
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#define VFS_IF_FILE (1UL << 0)
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#define VFS_IF_DIR (1UL << 1) // 文件夹
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#define VFS_IF_DEVICE (1UL << 2)
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#define VFS_IF_DEAD (1UL << 3) /* removed, but still open directory */
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struct vfs_super_block_operations_t;
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struct vfs_inode_operations_t;
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struct vfs_index_node_t;
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struct vfs_dir_entry_operations_t;
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#define VFS_DF_MOUNTED (1 << 0) // 当前dentry是一个挂载点
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#define VFS_DF_CANNOT_MOUNT (1 << 1) // 当前dentry是一个挂载点
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struct vfs_dir_entry_t
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{
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char *name;
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int name_length; // 名字的长度(不包含字符串末尾的'\0')
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uint32_t d_flags; // dentry标志位
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struct List child_node_list;
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struct List subdirs_list;
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struct lockref lockref; // 该lockref包含了dentry的自旋锁以及引用计数
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struct vfs_index_node_t *dir_inode;
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struct vfs_dir_entry_t *parent;
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struct vfs_dir_entry_operations_t *dir_ops;
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};
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struct vfs_superblock_t
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{
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struct vfs_dir_entry_t *root;
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struct vfs_super_block_operations_t *sb_ops;
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struct vfs_dir_entry_operations_t *dir_ops; // dentry's operations
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struct block_device *blk_device;
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void *private_sb_info;
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};
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/**
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* @brief inode结构体
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*
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*/
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struct vfs_index_node_t
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{
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uint64_t file_size; // 文件大小
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uint64_t blocks; // 占用的扇区数
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uint64_t attribute;
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struct lockref lockref; // 自旋锁与引用计数
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struct vfs_superblock_t *sb;
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struct vfs_file_operations_t *file_ops;
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struct vfs_inode_operations_t *inode_ops;
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void *private_inode_info;
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};
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/**
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* @brief 文件的mode
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*
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*/
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#define VFS_FILE_MODE_READ (1 << 0)
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#define VFS_FILE_MODE_WRITE (1 << 1)
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#define VFS_FILE_MODE_RW (VFS_FILE_MODE_READ | VFS_FILE_MODE_WRITE)
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#define vfs_file_can_read(file) (((file)->mode) & VFS_FILE_MODE_READ)
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#define vfs_file_can_write(file) (((file)->mode) & VFS_FILE_MODE_WRITE)
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#define vfs_file_can_rw(file) ((((file)->mode) & VFS_FILE_MODE_RW) == VFS_FILE_MODE_RW)
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/**
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* @brief 文件描述符
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*
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*/
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struct vfs_file_t
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{
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long position;
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uint64_t mode;
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struct vfs_dir_entry_t *dEntry;
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struct vfs_file_operations_t *file_ops;
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void *private_data;
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};
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struct vfs_filesystem_type_t
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{
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char *name;
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int fs_flags;
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struct vfs_superblock_t *(*read_superblock)(
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struct block_device *blk); // 解析文件系统引导扇区的函数,为文件系统创建超级块结构。
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struct vfs_filesystem_type_t *next;
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};
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struct vfs_super_block_operations_t
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{
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void (*write_superblock)(struct vfs_superblock_t *sb); // 将超级块信息写入磁盘
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void (*put_superblock)(struct vfs_superblock_t *sb);
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void (*write_inode)(struct vfs_index_node_t *inode); // 将inode信息写入磁盘
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};
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/**
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* @brief 对vfs的inode的操作抽象
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*
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*/
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struct vfs_inode_operations_t
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{
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/**
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* @brief 创建新的文件
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* @param parent_inode 父目录的inode结构体
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* @param dest_dEntry 新文件的dentry
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* @param mode 创建模式
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*/
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long (*create)(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_t *dest_dEntry, int mode);
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/**
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* @brief 在文件系统中查找指定的目录项
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* @param parent_inode 父目录项(在这个目录下查找)
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* @param dest_dEntry 构造的目标目录项的结构体(传入名称,然后更多的详细信息将在本函数中完成填写)
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*
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*/
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struct vfs_dir_entry_t *(*lookup)(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_t *dest_dEntry);
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/**
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* @brief 创建文件夹
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* @param inode 父目录的inode
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* @param dEntry 新的文件夹的dentry
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* @param mode 创建文件夹的mode
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*/
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long (*mkdir)(struct vfs_index_node_t *inode, struct vfs_dir_entry_t *dEntry, int mode);
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long (*rmdir)(struct vfs_index_node_t *inode, struct vfs_dir_entry_t *dEntry);
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long (*rename)(struct vfs_index_node_t *old_inode, struct vfs_dir_entry_t *old_dEntry,
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struct vfs_index_node_t *new_inode, struct vfs_dir_entry_t *new_dEntry);
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long (*getAttr)(struct vfs_dir_entry_t *dEntry, uint64_t *attr);
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long (*setAttr)(struct vfs_dir_entry_t *dEntry, uint64_t *attr);
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};
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struct vfs_dir_entry_operations_t
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{
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long (*compare)(struct vfs_dir_entry_t *parent_dEntry, char *source_filename, char *dest_filename);
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long (*hash)(struct vfs_dir_entry_t *dEntry, char *filename);
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long (*release)(struct vfs_dir_entry_t *dEntry);
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long (*iput)(struct vfs_dir_entry_t *dEntry, struct vfs_index_node_t *inode);
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};
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/**
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* @brief 填充dirent的函数指针的类型定义
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*
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*/
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typedef int (*vfs_filldir_t)(void *buf, ino_t d_ino, char *name, int namelen, unsigned char type, off_t offset);
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struct vfs_file_operations_t
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{
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long (*open)(struct vfs_index_node_t *inode, struct vfs_file_t *file_ptr);
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long (*close)(struct vfs_index_node_t *inode, struct vfs_file_t *file_ptr);
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long (*read)(struct vfs_file_t *file_ptr, char *buf, int64_t count, long *position);
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long (*write)(struct vfs_file_t *file_ptr, char *buf, int64_t count, long *position);
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long (*lseek)(struct vfs_file_t *file_ptr, long offset, long origin);
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long (*ioctl)(struct vfs_index_node_t *inode, struct vfs_file_t *file_ptr, uint64_t cmd, uint64_t arg);
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long (*readdir)(struct vfs_file_t *file_ptr, void *dirent, vfs_filldir_t filler); // 读取文件夹
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};
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/**
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* @brief 在VFS中注册文件系统
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*
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* @param fs 文件系统类型结构体
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* @return uint64_t
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*/
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uint64_t vfs_register_filesystem(struct vfs_filesystem_type_t *fs);
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uint64_t vfs_unregister_filesystem(struct vfs_filesystem_type_t *fs);
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/**
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* @brief 挂载文件系统
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*
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* @param path 要挂载到的路径
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* @param name 文件系统名
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* @param blk 块设备结构体
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* @return struct vfs_superblock_t* 挂载后,文件系统的超级块
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*/
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struct vfs_superblock_t *vfs_mount_fs(const char *path, char *name, struct block_device *blk);
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/**
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* @brief 按照路径查找文件
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*
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* @param path 路径
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* @param flags 1:返回父目录项, 0:返回结果目录项
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* @return struct vfs_dir_entry_t* 目录项
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*/
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struct vfs_dir_entry_t *vfs_path_walk(const char *path, uint64_t flags);
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/**
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* @brief 填充dentry
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*
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*/
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int vfs_fill_dirent(void *buf, ino_t d_ino, char *name, int namelen, unsigned char type, off_t offset);
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/**
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* @brief 初始化vfs
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*
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* @return int 错误码
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*/
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int vfs_init();
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/**
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* @brief 动态分配dentry以及路径字符串名称
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*
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* @param name_size 名称字符串大小(字节)(注意考虑字符串最后需要有一个‘\0’作为结尾)
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* @return struct vfs_dir_entry_t* 创建好的dentry
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*/
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struct vfs_dir_entry_t *vfs_alloc_dentry(const int name_size);
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/**
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* @brief 分配inode并将引用计数初始化为1
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*
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* @return struct vfs_index_node_t * 分配得到的inode
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*/
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struct vfs_index_node_t *vfs_alloc_inode();
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/**
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* @brief 打开文件
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*
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* @param filename 文件路径
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* @param flags 标志位
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* @return uint64_t 错误码
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*/
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uint64_t do_open(const char *filename, int flags);
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/**
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* @brief 创建文件夹
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*
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* @param path 文件夹路径
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* @param mode 创建模式
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* @param from_userland 该创建请求是否来自用户态
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* @return int64_t 错误码
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*/
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int64_t vfs_mkdir(const char *path, mode_t mode, bool from_userland);
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/**
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* @brief 删除文件夹
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*
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* @param path 文件夹路径
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* @param from_userland 请求是否来自用户态
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* @return int64_t 错误码
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*/
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int64_t vfs_rmdir(const char *path, bool from_userland);
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/**
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* @brief 释放dentry,并视情况自动释放inode。 在调用该函数前,需要将dentry加锁。
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*
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* @param dentry 目标dentry
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*
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* @return 错误码
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* 注意,当dentry指向文件时,如果返回值为正数,则表示在释放了该dentry后,该dentry指向的inode的引用计数。
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*/
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int vfs_dentry_put(struct vfs_dir_entry_t *dentry); |