commit 7658341eb936889420d68cc9a07e82e367d74b8e
Author: WangRunji <wangrunji0408@163.com>
Date:   Sat Apr 28 23:49:46 2018 +0800

    Init. Basic structures.

diff --git a/.gitignore b/.gitignore
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+++ b/.gitignore
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+/target
+**/*.rs.bk
+Cargo.lock
+.idea
+/sfs.img
diff --git a/Cargo.toml b/Cargo.toml
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+++ b/Cargo.toml
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+[package]
+name = "simple-filesystem"
+version = "0.1.0"
+authors = ["WangRunji <wangrunji0408@163.com>"]
+
+[dependencies]
+spin = "0.4"
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diff --git a/src/lib.rs b/src/lib.rs
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+++ b/src/lib.rs
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+#![feature(alloc)]
+#![no_std]
+
+extern crate spin;
+extern crate alloc;
+
+mod vfs;
+mod structs;
+#[cfg(test)]
+mod tests;
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diff --git a/src/structs.rs b/src/structs.rs
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+use spin::Mutex;
+use alloc::Vec;
+//use core::fmt::{Debug, Formatter, Error};
+
+/// On-disk superblock
+#[repr(C, packed)]
+struct SuperBlock {
+    /// magic number, should be SFS_MAGIC
+    magic: u32,
+    /// number of blocks in fs
+    blocks: u32,
+    /// number of unused blocks in fs
+    unused_blocks: u32,
+    /// infomation for sfs
+    info: [u8; MAX_INFO_LEN + 1],
+}
+
+/// inode (on disk)
+#[repr(C, packed)]
+#[derive(Debug)]
+struct DiskInode {
+    /// size of the file (in bytes)
+    size: u32,
+    /// one of SYS_TYPE_* above
+    type_: u16,
+    /// number of hard links to this file
+    nlinks: u16,
+    /// number of blocks
+    blocks: u32,
+    /// direct blocks
+    direct: [u32; NDIRECT],
+    /// indirect blocks
+    indirect: u32,
+    /// double indirect blocks
+    db_indirect: u32,
+}
+
+/// file entry (on disk)
+#[repr(C, packed)]
+struct DiskEntry {
+    /// inode number
+    inode_number: u32,
+    /// file name
+    name: [u8; MAX_FNAME_LEN + 1],
+}
+
+/// inode for sfs
+struct Inode {
+    /// on-disk inode
+    disk_inode: *mut DiskInode,
+    /// inode number
+    id: u32,
+    /// true if inode modified
+    dirty: bool,
+    /// kill inode if it hits zero
+    reclaim_count: u32,
+    /// semaphore for din
+    mutex: Mutex<()>,
+}
+
+/// filesystem for sfs
+struct SimpleFileSystem {
+    /// on-disk superblock
+    super_block: SuperBlock,
+    /// blocks in use are mared 0
+    free_map: [u8; 0],
+    /// true if super/freemap modified
+    super_dirty: bool,
+    /// buffer for non-block aligned io
+    buffer: [u8; 0],
+    /// semaphore for fs
+    fs_mutex: Mutex<()>,
+    /// semaphore for io
+    io_mutex: Mutex<()>,
+    /// semaphore for link/unlink and rename
+    link_mutex: Mutex<()>,
+    /// inode list
+    inodes: Vec<DiskInode>
+}
+
+/*
+ * Simple FS (SFS) definitions visible to ucore. This covers the on-disk format
+ * and is used by tools that work on SFS volumes, such as mksfs.
+ */
+/// magic number for sfs
+const MAGIC: usize = 0x2f8dbe2a;
+/// size of block
+const BLKSIZE: usize = 4096;
+/// number of direct blocks in inode
+const NDIRECT: usize = 12;
+/// max length of infomation
+const MAX_INFO_LEN: usize = 31;
+/// max length of filename
+const MAX_FNAME_LEN: usize = 255;
+/// max file size (128M)
+const MAX_FILE_SIZE: usize = 1024 * 1024 * 128;
+/// block the superblock lives in
+const BLKN_SUPER: usize = 0;
+/// location of the root dir inode
+const BLKN_ROOT: usize = 1;
+/// 1st block of the freemap
+const BLKN_FREEMAP: usize = 2;
+/// number of bits in a block
+const BLKBITS: usize = BLKSIZE * 8;
+/// number of entries in a block
+const BLK_NENTRY: usize = BLKSIZE / 4;
+
+/// file types
+enum FileType {
+    Invalid = 0, File = 1, Dir = 2, Link = 3,
+}
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diff --git a/src/tests.rs b/src/tests.rs
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+#[test]
+fn test() {
+
+}
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