|
|
@@ -0,0 +1,101 @@
|
|
|
+:::{note}
|
|
|
+**AI Translation Notice**
|
|
|
+
|
|
|
+This document was automatically translated by `hunyuan-turbos-latest` model, for reference only.
|
|
|
+
|
|
|
+- Source document: kernel/filesystem/vfs/mountable_fs.md
|
|
|
+
|
|
|
+- Translation time: 2025-06-29 09:58:15
|
|
|
+
|
|
|
+- Translation model: `hunyuan-turbos-latest`
|
|
|
+
|
|
|
+Please report issues via [Community Channel](https://github.com/DragonOS-Community/DragonOS/issues)
|
|
|
+
|
|
|
+:::
|
|
|
+
|
|
|
+:::{note}
|
|
|
+Author: Zhuang Kaiye
|
|
|
+
|
|
|
+Email: <sparkhhhhhhhhhh@outlook.com>
|
|
|
+:::
|
|
|
+
|
|
|
+# Design
|
|
|
+
|
|
|
+```mermaid
|
|
|
+ graph TD
|
|
|
+ subgraph 用户层 / 系统调用
|
|
|
+ A[sys_mount] --> B[produce_fs!]
|
|
|
+ end
|
|
|
+
|
|
|
+ subgraph 文件系统注册与创建
|
|
|
+ B --> C{查找 FSMAKER}
|
|
|
+ C -- 找到匹配 --> D[FileSystemMaker::builder && FileSystemMaker::maker]
|
|
|
+ D --> G[FileSystem 实例]
|
|
|
+ G --> H[挂载成功]
|
|
|
+ C -- 未找到 --> I[错误: EINVAL]
|
|
|
+ end
|
|
|
+
|
|
|
+ subgraph 文件系统实现者
|
|
|
+ J[RamFS / 其他文件系统] --> K[实现 MountableFileSystem trait]
|
|
|
+ K --> L[make_mount_data]
|
|
|
+ K --> M[make_fs]
|
|
|
+ L --> N[register_mountable_fs!宏]
|
|
|
+ M --> N
|
|
|
+ end
|
|
|
+
|
|
|
+ N --> O[分布式切片 FSMAKER ]
|
|
|
+ O --> C
|
|
|
+
|
|
|
+ click J "#" "RamFS - 文件系统示例"
|
|
|
+ click B "#" "produce_fs 函数"
|
|
|
+ click O "#" "FSMAKER - 文件系统工厂数组"
|
|
|
+```
|
|
|
+
|
|
|
+## Process Description:
|
|
|
+
|
|
|
+- A specific file system (e.g., `RamFS`) registers its creation logic with `FSMAKER` by implementing `MountableFileSystem trait` and using the `register_mountable_fs!` macro.
|
|
|
+- Users request to mount a file system via the `sys_mount` system call.
|
|
|
+- `sys_mount` calls the `produce_fs` function, passing the file system type, raw mount data, and source path.
|
|
|
+- `produce_fs` traverses the global `FSMAKER` array to find a FileSystemMaker matching the requested file system type name.
|
|
|
+- If found, it first calls `maker.builder` (which internally invokes the specific file system's `make_mount_data` method) to process the raw data and generate an optional `mount_data` object.
|
|
|
+- Next, it calls `maker.build` (which internally invokes the specific file system's `make_fs` method), passing the mount_data generated in the previous step, thereby creating the file system instance.
|
|
|
+- The successfully created file system instance (`Arc<dyn FileSystem>`) is returned and used for subsequent mount operations.
|
|
|
+- If no matching file system type is found, an error is returned.
|
|
|
+
|
|
|
+## Additional Notes
|
|
|
+
|
|
|
+Currently, DragonOS supports mounting the following file systems: `ramfs`, `ext4`, and `vfat`. When mounting disk files in DragonOS, note the following:
|
|
|
+
|
|
|
+- Since the system cannot directly determine the file system type of a disk, the target partition's file system type must be explicitly known before mounting.
|
|
|
+- The mount operation requires specifying the corresponding disk device name (located under /dev).
|
|
|
+- These disk device files are generated by modifying the `tools/run-qemu.sh` startup script to load the prepared disk image files into the system. Examples of virtio disk device naming include `vda1` and `vdb1`. The device names of disks in DragonOS are automatically assigned based on the order in which images are loaded in `run-qemu.sh` (a, b, c, etc.), with numbers indicating partition numbers.
|
|
|
+
|
|
|
+Therefore, to mount a disk currently, you can modify the `test-mount-ext4` executable to mount the specified disk file with the corresponding file system format. Below is an example of the mount operation:
|
|
|
+
|
|
|
+```Rust
|
|
|
+use core::ffi::{c_char, c_void};
|
|
|
+use libc::{mount, MS_BIND};
|
|
|
+use std::fs;
|
|
|
+use std::path::Path;
|
|
|
+
|
|
|
+fn main() {
|
|
|
+ let ext4_path = Path::new("mnt/ext4");
|
|
|
+ let dir = fs::create_dir_all(ext4_path);
|
|
|
+ if dir.is_err() {
|
|
|
+ panic!("mkdir /mnt/ext4 fail.");
|
|
|
+ }
|
|
|
+
|
|
|
+ // 硬盘名称，由传入顺序决定
|
|
|
+ let source = b"/dev/vdb1\0".as_ptr() as *const c_char;
|
|
|
+ let target = b"/mnt/ext4\0".as_ptr() as *const c_char;
|
|
|
+ // 文件系统类型
|
|
|
+ let fstype = b"ext4\0".as_ptr() as *const c_char;
|
|
|
+ let flags = MS_BIND;
|
|
|
+ let data = std::ptr::null() as *const c_void;
|
|
|
+ let _ = unsafe { mount(source, target, fstype, flags, data) };
|
|
|
+
|
|
|
+ println!("Mount successfully!");
|
|
|
+}
|
|
|
+```
|
|
|
+
|
|
|
+As for disk image creation, you can run `sudo bash tools/make_fs_image.sh` to simultaneously create disk images for `ext4` and `fat`. After entering the system, two additional disk files (`vdb1` and `vdc1`) will appear in the dev directory. You can then execute the `test-mount-ext4` and `test-mount-fat` test programs to verify the setup.
|
github-actions[bot]