diff options
Diffstat (limited to 'ayafs')
| -rw-r--r-- | ayafs/Cargo.toml | 18 | ||||
| -rw-r--r-- | ayafs/src/block_device/disk.rs | 47 | ||||
| -rw-r--r-- | ayafs/src/block_device/memory_disk.rs | 33 | ||||
| -rw-r--r-- | ayafs/src/block_device/mod.rs | 10 | ||||
| -rw-r--r-- | ayafs/src/disk/allocation.rs | 542 | ||||
| -rw-r--r-- | ayafs/src/disk/bitmap.rs | 48 | ||||
| -rw-r--r-- | ayafs/src/disk/block.rs | 245 | ||||
| -rw-r--r-- | ayafs/src/disk/inode.rs | 312 | ||||
| -rw-r--r-- | ayafs/src/disk/mod.rs | 6 | ||||
| -rw-r--r-- | ayafs/src/filesystem/mod.rs | 2 | ||||
| -rw-r--r-- | ayafs/src/filesystem/trait_impl.rs | 1247 | ||||
| -rw-r--r-- | ayafs/src/main.rs | 171 | ||||
| -rw-r--r-- | ayafs/src/memory/cached_block.rs | 180 | ||||
| -rw-r--r-- | ayafs/src/memory/cached_inode.rs | 178 | ||||
| -rw-r--r-- | ayafs/src/memory/dir_entry.rs | 305 | ||||
| -rw-r--r-- | ayafs/src/memory/file_handle.rs | 15 | ||||
| -rw-r--r-- | ayafs/src/memory/mod.rs | 6 | ||||
| -rw-r--r-- | ayafs/src/tests/bitmap.rs | 38 | ||||
| -rw-r--r-- | ayafs/src/tests/block_cache.rs | 245 | ||||
| -rw-r--r-- | ayafs/src/tests/common/mod.rs | 9 | ||||
| -rw-r--r-- | ayafs/src/tests/mod.rs | 6 | ||||
| -rw-r--r-- | ayafs/src/utils/constants.rs | 1 | ||||
| -rw-r--r-- | ayafs/src/utils/mod.rs | 92 | ||||
| -rw-r--r-- | ayafs/src/utils/permissions.rs | 62 |
24 files changed, 3818 insertions, 0 deletions
diff --git a/ayafs/Cargo.toml b/ayafs/Cargo.toml new file mode 100644 index 0000000..43585e0 --- /dev/null +++ b/ayafs/Cargo.toml @@ -0,0 +1,18 @@ +[package] +name = "ayafs" +version = "0.1.0" +edition = "2021" + +# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html + +[dependencies] +and_then_some = "1.0.0" +bitflags = "2.4.1" +clap = { version = "4.4.10", features = ["derive"] } +env_logger = "0.10.1" +fuser = "0.14.0" +indexmap = "2.1.0" +libc = "0.2.150" +log = "0.4.20" +lru = "0.12.1" +users = "0.11.0" diff --git a/ayafs/src/block_device/disk.rs b/ayafs/src/block_device/disk.rs new file mode 100644 index 0000000..3f0b018 --- /dev/null +++ b/ayafs/src/block_device/disk.rs @@ -0,0 +1,47 @@ +use std::cell::RefCell; +use std::fs::File; +use std::io::{Read, Seek, SeekFrom, Write}; +use std::path::{Path, PathBuf}; +use crate::block_device::{BLOCK_SIZE, BlockDevice}; + +pub struct Disk { + disk_path: PathBuf, + device: RefCell<File>, +} + +impl Disk { + pub fn new(disk_path: PathBuf) -> Self { + let device = File::options() + .read(true) + .write(true) + .open(disk_path.as_path()) + .unwrap(); + // let device = File::open(disk_path.as_path()).unwrap(); + Self { + disk_path, + device: RefCell::new(device), + } + } +} + +impl BlockDevice for Disk { + fn read(&self, block_id: usize, buffer: &mut [u8]) { + let mut device = self.device.borrow_mut(); + device + .seek(SeekFrom::Start((block_id * BLOCK_SIZE) as u64)) + .expect("Unable to seek!"); + device + .read_exact(buffer) + .expect("Failed to read 4096 bytes!"); + } + + fn write(&self, block_id: usize, buffer: &[u8]) { + let mut device = self.device.borrow_mut(); + device + .seek(SeekFrom::Start((block_id * BLOCK_SIZE) as u64)) + .expect("Unable to seek!"); + device + .write_all(buffer) + .expect("Unable to write 4096 bytes!"); + } +}
\ No newline at end of file diff --git a/ayafs/src/block_device/memory_disk.rs b/ayafs/src/block_device/memory_disk.rs new file mode 100644 index 0000000..0639d3e --- /dev/null +++ b/ayafs/src/block_device/memory_disk.rs @@ -0,0 +1,33 @@ +use crate::block_device::{BlockDevice, BLOCK_SIZE}; +use std::cell::RefCell; + +#[repr(C)] +pub struct MemoryDisk { + /// Emulating a block device with a segment of RAM, + /// which is 64MiB == 4KiB per block * 16384 blocks + pub arena: RefCell<Vec<u8>>, +} + +impl MemoryDisk { + pub fn new(block_number: usize) -> Self { + Self { + arena: RefCell::new(vec![0u8; BLOCK_SIZE * block_number]), + } + } +} + +impl BlockDevice for MemoryDisk { + fn read(&self, block_id: usize, buffer: &mut [u8]) { + let block_front = block_id * BLOCK_SIZE; + let block_back = block_front + BLOCK_SIZE; + let arena = self.arena.borrow(); + buffer.copy_from_slice(&arena[block_front..block_back]); + } + + fn write(&self, block_id: usize, buffer: &[u8]) { + let block_front = block_id * BLOCK_SIZE; + let block_back = block_front + BLOCK_SIZE; + let mut arena = self.arena.borrow_mut(); + arena[block_front..block_back].copy_from_slice(buffer); + } +} diff --git a/ayafs/src/block_device/mod.rs b/ayafs/src/block_device/mod.rs new file mode 100644 index 0000000..a1e6544 --- /dev/null +++ b/ayafs/src/block_device/mod.rs @@ -0,0 +1,10 @@ +/// Abstracts for block devices. +/// Currently only a mock memory disk. +pub mod memory_disk; +pub mod disk; + +pub const BLOCK_SIZE: usize = 4096; +pub trait BlockDevice { + fn read(&self, block_id: usize, buffer: &mut [u8]); + fn write(&self, block_id: usize, buffer: &[u8]); +} diff --git a/ayafs/src/disk/allocation.rs b/ayafs/src/disk/allocation.rs new file mode 100644 index 0000000..a187fad --- /dev/null +++ b/ayafs/src/disk/allocation.rs @@ -0,0 +1,542 @@ +use crate::disk::block::{ + Block, DataBlock, DoubleIndirectBlock, IndirectBlock, TripleIndirectBlock, +}; +use crate::disk::inode::{Inode, DIRECT_NUMBER, ENTRY_PER_BLOCK}; +use crate::memory::cached_block::{convert, CachedBlock}; +use crate::AyaFS; +use libc::c_int; +use log::debug; + +impl AyaFS { + /// 为 Inode 分配新 block, 返回 block 的编号和它在 inode 内的编号 + pub(crate) fn allocate_block_for(&mut self, inode: &mut Inode) -> Option<(u32, usize)> { + // 先看这个 inode 的 direct block 有没有空闲 + for (index_within_direct, index) in inode.direct.iter_mut().enumerate() { + if !self.data_bitmap.query(*index as usize) { + let block_index = self.data_bitmap.allocate().unwrap() as u32; + // println!("allocating {} for direct", block_index); + *index = block_index; + inode.n_blocks += 1; + // 初始化这个 block + self.init_block(block_index as usize); + // 当调用 get_inode_mut 拿出 &mut Inode 的时候对应的 block 在 cache 里已经脏了 + return Some((block_index, index_within_direct)); + } + } + + // direct block 全部分配完了, 先检查 indirect block 有没有分配, 没有就分配一个 + if !self.data_bitmap.query(inode.single_indirect as usize) { + inode.single_indirect = self + .data_bitmap + .allocate() + .expect("No free space for new block") as u32; + self.init_block(inode.single_indirect as usize); + // println!("allocating {} for indirect", inode.single_indirect); + } + // 在 indirect block 里尝试分配 + if let Some((block_index, index_within_indirect)) = + self.allocate_in_indirect(inode.single_indirect) + { + // println!("allocating {} in indirect", block_index); + inode.n_blocks += 1; + + let index_within_block = DIRECT_NUMBER + index_within_indirect; + return Some((block_index, index_within_block)); + } + + // direct & indirect block 全部分配完了, 先检查 double indirect block 有没有分配, 没有就分配一个 + if !self.data_bitmap.query(inode.double_indirect as usize) { + inode.double_indirect = self + .data_bitmap + .allocate() + .expect("No free space for new block") as u32; + self.init_block(inode.double_indirect as usize); + // println!("allocating {} for double indirect", inode.double_indirect); + } + // 在 double indirect block 里尝试分配 + if let Some((block_index, index_within_double)) = + self.alloc_in_double_indirect(inode.double_indirect) + { + // println!("allocating {} in double indirect", block_index); + inode.n_blocks += 1; + let index_within_block = DIRECT_NUMBER + ENTRY_PER_BLOCK + index_within_double; + return Some((block_index, index_within_block)); + } + + // direct, indirect & double indirect block 全部分配完了, 先检查 triple indirect block 有没有分配, 没有就分配一个 + if !self.data_bitmap.query(inode.triple_indirect as usize) { + inode.triple_indirect = self + .data_bitmap + .allocate() + .expect("No free space for new block") as u32; + self.init_block(inode.triple_indirect as usize); + // println!("allocating {} for triple indirect", inode.triple_indirect); + } + // 在 double indirect block 里尝试分配 + if let Some((block_index, index_within_triple)) = + self.alloc_in_triple_indirect(inode.triple_indirect) + { + // println!("allocating {} in triple indirect", block_index); + inode.n_blocks += 1; + let index_within_block = DIRECT_NUMBER + + ENTRY_PER_BLOCK + + ENTRY_PER_BLOCK * ENTRY_PER_BLOCK + + index_within_triple; + return Some((block_index, index_within_block)); + } + None + } + + fn allocate_in_indirect(&mut self, indirect_entry: u32) -> Option<(u32, usize)> { + // 取出 single indirect block, 尝试在里面分配 + let indirect_entry = indirect_entry as usize; + // println!("finding indirect block with number {}, bitmap says {}", indirect_entry, self.data_bitmap.query(indirect_entry)); + + if let Some(block) = self + .get_block(indirect_entry) + .map(convert::<DataBlock, IndirectBlock>) + { + // println!("found indirect block with number {}", indirect_entry); + let mut indirect_block = block.clone(); + for (index_within_indirect, entry) in + indirect_block.block.entries.iter_mut().enumerate() + { + if self.data_bitmap.query(*entry as usize) == false { + indirect_block.dirty = true; // 把这个块标记为 dirty + let block_index = self.data_bitmap.allocate().expect("No free space") as u32; + self.init_block(block_index as usize); + *entry = block_index; + self.update_block(indirect_block); + return Some((block_index, index_within_indirect)); + } + } + } + None + } + + fn alloc_in_double_indirect(&mut self, double_indirect_entry: u32) -> Option<(u32, usize)> { + let double_indirect_entry = double_indirect_entry as usize; + + if let Some(block) = self + .get_block(double_indirect_entry) + .map(convert::<DataBlock, DoubleIndirectBlock>) + { + let mut double_indirect_block = block.clone(); + let mut double_indirect_modified = false; + for (index_within_double_indirect, indirect_entry) in + double_indirect_block.block.indirect.iter_mut().enumerate() + { + if self.data_bitmap.query(*indirect_entry as usize) == false { + double_indirect_block.dirty = true; + double_indirect_modified = true; + + let indirect_index = self.data_bitmap.allocate().expect("No free space"); + *indirect_entry = indirect_index as u32; + self.init_block(indirect_index); + } + + if let Some((block_index, index_within_indirect)) = + self.allocate_in_indirect(*indirect_entry) + { + if double_indirect_modified { + self.update_block(double_indirect_block); + } + let index_within_double = + index_within_double_indirect * ENTRY_PER_BLOCK + index_within_indirect; + return Some((block_index, index_within_double)); + } + } + } + None + } + + fn alloc_in_triple_indirect(&mut self, triple_indirect_entry: u32) -> Option<(u32, usize)> { + let triple_indirect_entry = triple_indirect_entry as usize; + + if let Some(block) = self + .get_block(triple_indirect_entry) + .map(convert::<DataBlock, TripleIndirectBlock>) + { + let mut triple_indirect_block = block.clone(); + let mut triple_indirect_modified = false; + for (index_within_triple_indirect, double_indirect_entry) in triple_indirect_block + .block + .double_indirect + .iter_mut() + .enumerate() + { + if self.data_bitmap.query(*double_indirect_entry as usize) == false { + triple_indirect_block.dirty = true; + triple_indirect_modified = true; + + let double_indirect_index = self.data_bitmap.allocate().expect("No free space"); + *double_indirect_entry = double_indirect_index as u32; + self.init_block(double_indirect_index) + } + if let Some((block_index, index_within_double_indirect)) = + self.alloc_in_double_indirect(*double_indirect_entry) + { + if triple_indirect_modified { + self.update_block(triple_indirect_block); + } + let index_within_triple = + index_within_triple_indirect * ENTRY_PER_BLOCK * ENTRY_PER_BLOCK + + index_within_double_indirect; + return Some((block_index, index_within_triple)); + } + } + } + None + } +} + +impl AyaFS { + pub(crate) fn deallocate_all_blocks_for(&mut self, inode: &Inode) -> Result<(), c_int> { + // 遍历 direct block 并删除 + for block_index in inode.direct { + self.data_bitmap.deallocate(block_index as usize); + } + + // 遍历 indirect block 并删除 + if self.data_bitmap.query(inode.single_indirect as usize) { + let indirect = self + .get_block::<IndirectBlock>(inode.single_indirect as usize) + .unwrap(); + for block_index in indirect.block.entries { + self.data_bitmap.deallocate(block_index as usize); + } + self.data_bitmap.deallocate(inode.single_indirect as usize); + } + + // 遍历 double indirect block 并删除 + if self.data_bitmap.query(inode.double_indirect as usize) { + let double_indirect = self + .get_block::<DoubleIndirectBlock>(inode.double_indirect as usize) + .unwrap(); + for indirect_block_index in double_indirect.block.indirect { + if let Some(indirect) = + self.get_block::<IndirectBlock>(indirect_block_index as usize) + { + for block_index in indirect.block.entries { + self.data_bitmap.deallocate(block_index as usize); + } + self.data_bitmap.deallocate(indirect_block_index as usize); + } + } + self.data_bitmap.deallocate(inode.double_indirect as usize); + } + + // 遍历 triple indirect block 并删除 + if self.data_bitmap.query(inode.triple_indirect as usize) { + let triple_indirect = self + .get_block::<TripleIndirectBlock>(inode.triple_indirect as usize) + .unwrap(); + for double_indirect_block_index in triple_indirect.block.double_indirect { + if let Some(double_indirect) = + self.get_block::<DoubleIndirectBlock>(double_indirect_block_index as usize) + { + for indirect_block_index in double_indirect.block.indirect { + if let Some(indirect) = + self.get_block::<IndirectBlock>(indirect_block_index as usize) + { + for block_index in indirect.block.entries { + self.data_bitmap.deallocate(block_index as usize); + } + self.data_bitmap.deallocate(indirect_block_index as usize); + } + } + self.data_bitmap + .deallocate(double_indirect_block_index as usize); + } + } + self.data_bitmap.deallocate(inode.triple_indirect as usize); + } + + Ok(()) + } + + /// 从 inode 中删去最后一个 block + pub(crate) fn deallocate_block_for(&mut self, inode: &mut Inode) -> Option<u32> { + // 如果 triple indirect 块存在, 则尝试从中销毁一个块 + if self.data_bitmap.query(inode.triple_indirect as usize) { + if let Some(block_index) = self.deallocate_from_triple_indirect(inode.triple_indirect) { + inode.n_blocks -= 1; + return Some(block_index); // 销毁成功, 直接返回 + } else { + // 销毁失败, 说明 triple indirect 空了, 把它也销毁. + self.data_bitmap.deallocate(inode.triple_indirect as usize); + inode.triple_indirect = 0; // 这个地方理论上应该不用? + } + } + // 如果 double indirect 块存在, 则从其中销毁 + if self.data_bitmap.query(inode.double_indirect as usize) { + if let Some(block_index) = self.deallocate_from_double_indirect(inode.double_indirect) { + inode.n_blocks -= 1; + return Some(block_index); + } else { + self.data_bitmap.deallocate(inode.double_indirect as usize); + inode.double_indirect = 0; // 这个地方理论上应该不用? + } + } + // 如果 indirect 块存在, 则从其中销毁 + if self.data_bitmap.query(inode.single_indirect as usize) { + if let Some(block_index) = self.deallocate_from_indirect(inode.single_indirect) { + inode.n_blocks -= 1; + return Some(block_index); + } else { + self.data_bitmap.deallocate(inode.single_indirect as usize); + inode.single_indirect = 0; // 这个地方理论上应该不用? + } + } + // 都没有，直接从 direct 块中销毁 + for entry in inode.direct.iter_mut().rev() { + if self.data_bitmap.query(*entry as usize) { + let index = std::mem::replace(entry, 0); // let index = *entry; *entry = 0; + inode.n_blocks -= 1; + self.data_bitmap.deallocate(index as usize); + return Some(index); + } + } + None + } + + fn deallocate_from_triple_indirect(&mut self, triple_indirect_entry: u32) -> Option<u32> { + let triple_indirect_entry = triple_indirect_entry as usize; + if let Some(triple_indirect_block) = self + .get_block(triple_indirect_entry) + .map(convert::<DataBlock, TripleIndirectBlock>) + { + let mut triple_indirect_block = triple_indirect_block.clone(); + let mut block_modified = false; + for double_indirect_entry in + triple_indirect_block.block.double_indirect.iter_mut().rev() + { + // 如果这个位置的 double indirect 存在 + if self.data_bitmap.query(*double_indirect_entry as usize) { + // 尝试从中销毁一个块 + if let Some(block_index) = + self.deallocate_from_double_indirect(*double_indirect_entry) + { + if block_modified { + self.update_block(triple_indirect_block); + } + return Some(block_index); // 成功则直接返回 + } else { + // 失败则把这个 double indirect 销毁 + let double_indirect_entry_to_deallocate = + std::mem::replace(double_indirect_entry, 0); + self.data_bitmap + .deallocate(double_indirect_entry_to_deallocate as usize); + triple_indirect_block.dirty = true; + block_modified = true; + } + } + } + if block_modified { + self.update_block(triple_indirect_block); + } + } + None + } + + fn deallocate_from_double_indirect(&mut self, double_indirect_entry: u32) -> Option<u32> { + let double_indirect_entry = double_indirect_entry as usize; + if let Some(double_indirect_block) = self + .get_block(double_indirect_entry) + .map(convert::<DataBlock, DoubleIndirectBlock>) + { + let mut double_indirect_block = double_indirect_block.clone(); + let mut block_modified = false; + for indirect_entry in double_indirect_block.block.indirect.iter_mut().rev() { + // 如果这个位置的 indirect 存在 + if self.data_bitmap.query(*indirect_entry as usize) { + // 尝试从中销毁一个块 + if let Some(block_index) = self.deallocate_from_indirect(*indirect_entry) { + if block_modified { + self.update_block(double_indirect_block); + } + return Some(block_index); // 成功则直接返回 + } else { + // 失败则把这个 indirect 销毁 + let indirect_entry_to_deallocate = std::mem::replace(indirect_entry, 0); + self.data_bitmap + .deallocate(indirect_entry_to_deallocate as usize); + double_indirect_block.dirty = true; + block_modified = true; + } + } + } + if block_modified { + self.update_block(double_indirect_block); + } + } + None + } + + fn deallocate_from_indirect(&mut self, indirect_entry: u32) -> Option<u32> { + let indirect_entry = indirect_entry as usize; + if let Some(indirect_block) = self + .get_block(indirect_entry) + .map(convert::<DataBlock, IndirectBlock>) + { + let mut indirect_block = indirect_block.clone(); + // 遍历 indirect block 里的每个 block + for entry in indirect_block.block.entries.iter_mut().rev() { + // 如果这个 block 存在, 销毁它 + if self.data_bitmap.query(*entry as usize) { + let entry_to_deallocate = std::mem::replace(entry, 0); + + self.data_bitmap.deallocate(entry_to_deallocate as usize); + indirect_block.dirty = true; + self.update_block(indirect_block); + + return Some(entry_to_deallocate); + } + } + } + None + } +} + +impl AyaFS { + pub(crate) fn get_block_index( + &mut self, + inode: &Inode, + mut block_index_within_inode: usize, + ) -> Option<usize> { + debug!( + "get_block_index(block_index_within_inode: {})", + block_index_within_inode + ); + // direct block + if block_index_within_inode < DIRECT_NUMBER { + let block_index = inode.direct[block_index_within_inode] as usize; + debug!(" get_block_index -> direct"); + return if self.data_bitmap.query(block_index) { + debug!(" get_block_index -> direct -> ✓"); + Some(block_index) + } else { + debug!(" get_block_index -> direct -> ×"); + None + }; + } else { + block_index_within_inode -= DIRECT_NUMBER; + } + + // indirect block + let indirect_number = ENTRY_PER_BLOCK; + if block_index_within_inode < indirect_number { + return if let Some(indirect_block) = + self.get_block::<IndirectBlock>(inode.single_indirect as usize) + { + debug!(" get_block_index -> indirect"); + let block_index = indirect_block.block.entries[block_index_within_inode] as usize; + if self.data_bitmap.query(block_index) { + debug!(" get_block_index -> indirect -> ✓"); + Some(block_index) + } else { + debug!(" get_block_index -> indirect -> ×"); + None + } + } else { + debug!(" get_block_index -> indirect -> ×"); + None + }; + } else { + block_index_within_inode -= indirect_number; + } + + // double indirect block + let double_indirect_number = ENTRY_PER_BLOCK * ENTRY_PER_BLOCK; + if block_index_within_inode < double_indirect_number { + if let Some(double_indirect_block) = + self.get_block::<DoubleIndirectBlock>(inode.double_indirect as usize) + { + debug!(" get_block_index -> double_indirect"); + // 取出 double indirect block + let indirect_block_index = double_indirect_block.block.indirect + [block_index_within_inode / ENTRY_PER_BLOCK] + as usize; + // 要找的 entry 在 double indirect block 中的第几个 indirect block + if let Some(indirect_block) = self.get_block::<IndirectBlock>(indirect_block_index) + { + debug!(" get_block_index -> double_indirect -> indirect"); + let block_index = indirect_block.block.entries + [block_index_within_inode % ENTRY_PER_BLOCK] + as usize; + // 拿到 DirectoryBlock 的 index + return if self.data_bitmap.query(block_index) { + debug!(" get_block_index -> double_indirect -> indirect -> ✓"); + Some(block_index) + } else { + debug!(" get_block_index -> double_indirect -> indirect -> ×"); + None + }; + } + } + return None; + } else { + block_index_within_inode -= double_indirect_number; + } + + // triple indirect block + if let Some(triple_indirect_block) = + self.get_block::<TripleIndirectBlock>(inode.triple_indirect as usize) + { + // 取出 triple indirect block + let double_indirect_block_index = triple_indirect_block.block.double_indirect + [block_index_within_inode / (ENTRY_PER_BLOCK * ENTRY_PER_BLOCK)] + as usize; + // 要找的 entry 在 triple indirect block 中的第几个 double indirect block + if let Some(double_indirect_block) = + self.get_block::<DoubleIndirectBlock>(double_indirect_block_index) + { + // 取出 double indirect block + let indirect_block_index = double_indirect_block.block.indirect + [block_index_within_inode % (ENTRY_PER_BLOCK * ENTRY_PER_BLOCK) + / ENTRY_PER_BLOCK] as usize; + // 要找的 entry 在 double indirect block 中的第几个 indirect block + if let Some(indirect_block) = self.get_block::<IndirectBlock>(indirect_block_index) + { + let block_index = indirect_block.block.entries + [block_index_within_inode % ENTRY_PER_BLOCK] + as usize; + // DirectoryBlock 的 index + return if self.data_bitmap.query(block_index) { + Some(block_index) + } else { + None + }; + } + } + } + + None + } + + pub(crate) fn access_block<T: Block>( + &mut self, + inode: &Inode, + block_index_within_inode: usize, + ) -> Option<&CachedBlock<T>> { + self.get_block_index(inode, block_index_within_inode) + .map(|block_index| { + self.get_block::<T>(block_index).unwrap() // 可以 unwrap 吧这里 ?? + }) + } + + pub(crate) fn access_block_mut<T: Block>( + &mut self, + inode: &Inode, + block_index_within_inode: usize, + ) -> Option<&mut CachedBlock<T>> { + self.get_block_index(inode, block_index_within_inode) + .map(|block_index| { + debug!( + "access_block_mut(index: {}) found", + block_index_within_inode + ); + self.get_block_mut::<T>(block_index).unwrap() // 可以 unwrap 吧这里 ?? + }) + } +} diff --git a/ayafs/src/disk/bitmap.rs b/ayafs/src/disk/bitmap.rs new file mode 100644 index 0000000..b68c341 --- /dev/null +++ b/ayafs/src/disk/bitmap.rs @@ -0,0 +1,48 @@ +use crate::block_device::{BlockDevice, BLOCK_SIZE}; +use std::sync::Arc; + +pub struct Bitmap { + pub starting_block: usize, + pub length: usize, + pub device: Arc<dyn BlockDevice>, + pub data: Vec<u8>, +} + +impl Bitmap { + pub(crate) fn new(starting_block: usize, length: usize, device: Arc<dyn BlockDevice>) -> Self { + Self { + starting_block, + length, + device, + data: vec![0u8; length * BLOCK_SIZE], + } + } + pub(crate) fn allocate(&mut self) -> Option<usize> { + for (i, byte) in self.data.iter_mut().enumerate() { + let leading_ones = byte.leading_ones(); + if leading_ones != 8 { + *byte |= (1 << (7 - leading_ones)) as u8; + return Some(i * 8 + leading_ones as usize); + } + } + None + } + + pub(crate) fn query(&self, index: usize) -> bool { + if index == 0 { + false + } else { + self.data[index / 8] & ((1 << (7 - index % 8)) as u8) != 0 + } + } + + pub(crate) fn deallocate(&mut self, index: usize) -> bool { + if self.query(index) { + let mask = !(1u8 << (7 - index % 8)); + self.data[index / 8] &= mask; + true + } else { + false + } + } +} diff --git a/ayafs/src/disk/block.rs b/ayafs/src/disk/block.rs new file mode 100644 index 0000000..73819e2 --- /dev/null +++ b/ayafs/src/disk/block.rs @@ -0,0 +1,245 @@ +use crate::disk::inode::Inode; +use std::ffi::{OsStr, OsString}; +use std::os::unix::ffi::OsStrExt; + +pub trait Block: Default + Clone {} + +#[repr(C)] +#[derive(Clone)] +pub struct DataBlock(pub(crate) [u8; 4096]); + +impl Default for DataBlock { + fn default() -> Self { + Self([0; 4096]) + } +} + +impl Block for DataBlock {} + +#[repr(C)] +#[derive(Clone)] +pub struct InodeBlock { + pub(crate) inodes: [Inode; 32], +} + +impl Default for InodeBlock { + fn default() -> Self { + Self { + inodes: [ + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + Inode::empty(), + ], + } + } +} + +impl Block for InodeBlock {} + +#[repr(C)] +#[derive(Clone)] +pub struct DirectoryEntry { + pub inode: u32, + pub record_len: u16, + pub name_len: u8, + pub file_type: u8, + pub name: [u8; 256], +} + +impl DirectoryEntry { + pub(crate) fn name(&self) -> OsString { + let name = &self.name[0..self.name_len as usize]; + OsStr::from_bytes(name).to_os_string() + } +} + +impl Default for DirectoryEntry { + fn default() -> Self { + Self { + inode: 0, + record_len: 0, + name_len: 0, + file_type: 0x0, + name: [0; 256], + } + } +} + +#[repr(C)] +#[derive(Clone)] +pub struct DirectoryBlock { + pub entries: [DirectoryEntry; 15], + pub occupancy: [u8; 2], + reserved: [u8; 134], +} + +impl Default for DirectoryBlock { + fn default() -> Self { + Self { + entries: [ + DirectoryEntry::default(), + DirectoryEntry::default(), + DirectoryEntry::default(), + DirectoryEntry::default(), + DirectoryEntry::default(), + DirectoryEntry::default(), + DirectoryEntry::default(), + DirectoryEntry::default(), + DirectoryEntry::default(), + DirectoryEntry::default(), + DirectoryEntry::default(), + DirectoryEntry::default(), + DirectoryEntry::default(), + DirectoryEntry::default(), + DirectoryEntry::default(), + ], + occupancy: [0x80, 0x00], // 0b1000_0000 + reserved: [0xFF; 134], + } + } +} + +impl DirectoryBlock { + #[allow(unused)] + pub(crate) fn is_full(&self) -> bool { + self.occupancy[0] == 0xFF && self.occupancy[1] == 0xFF + } + + pub(crate) fn query(&self, mut index: usize) -> bool { + if index < 7 { + // 0-6, first u8 + index = index + 1; + self.occupancy[0] & (1 << (7 - index)) as u8 != 0 + } else if index < 15 { + // 7-14, second u8 + index = index - 7; + self.occupancy[1] & (1 << (7 - index)) as u8 != 0 + } else { + false + } + } + + pub(crate) fn allocate(&mut self, mut index: usize) -> bool { + if index < 7 { + index = index + 1; + let mask = (1 << (7 - index)) as u8; + if self.occupancy[0] & mask != 0 { + false + } else { + self.occupancy[0] |= mask; + true + } + } else { + index = index - 7; + let mask = (1 << (7 - index)) as u8; + if self.occupancy[1] & mask != 0 { + false + } else { + self.occupancy[1] |= mask; + true + } + } + } + + // pub(crate) fn allocate(&mut self) -> Option<usize> { + // if self.occupancy[0] != 0xFF { + // let leading_ones = self.occupancy[0].leading_ones(); + // self.occupancy[0] |= (1 << (7 - leading_ones)) as u8; + // Some(leading_ones as usize) + // } else if self.occupancy[1] != 0xFF { + // let leading_ones = self.occupancy[1].leading_ones(); + // self.occupancy[1] |= (1 << (7 - leading_ones)) as u8; + // Some(7 + leading_ones as usize) + // } else { + // None + // } + // } + + pub(crate) fn deallocate(&mut self, mut index: usize) { + if index < 7 { + index = index + 1; + self.occupancy[0] &= !((1 << (7 - index)) as u8); + } else if index < 15 { + // 7-14, second u8 + index = index - 7; + self.occupancy[1] &= !((1 << (7 - index)) as u8); + } + } +} + +impl Block for DirectoryBlock {} + +#[repr(C)] +#[derive(Clone)] +pub struct IndirectBlock { + pub entries: [u32; 1024], +} + +impl Default for IndirectBlock { + fn default() -> Self { + Self { entries: [0; 1024] } + } +} + +impl Block for IndirectBlock {} + +#[repr(C)] +#[derive(Clone)] +pub struct DoubleIndirectBlock { + pub indirect: [u32; 1024], +} + +impl Default for DoubleIndirectBlock { + fn default() -> Self { + Self { + indirect: [0; 1024], + } + } +} + +impl Block for DoubleIndirectBlock {} + +#[repr(C)] +#[derive(Clone)] +pub struct TripleIndirectBlock { + pub double_indirect: [u32; 1024], +} + +impl Default for TripleIndirectBlock { + fn default() -> Self { + Self { + double_indirect: [0; 1024], + } + } +} + +impl Block for TripleIndirectBlock {} diff --git a/ayafs/src/disk/inode.rs b/ayafs/src/disk/inode.rs new file mode 100644 index 0000000..0c801ad --- /dev/null +++ b/ayafs/src/disk/inode.rs @@ -0,0 +1,312 @@ +use crate::utils; +use bitflags::bitflags; +use fuser::FileType; +use crate::block_device::BLOCK_SIZE; + +pub const DIRECT_NUMBER: usize = 15; + +#[derive(Debug, Clone, Copy)] +pub struct InodeMode(pub u16); + +bitflags! { + impl InodeMode: u16 { + const IXOTH = 0x0001; + const IWOTH = 0x0002; + const IROTH = 0x0004; + const IXGRP = 0x0008; + const IWGRP = 0x0010; + const IRGRP = 0x0020; + const IXUSR = 0x0040; + const IWUSR = 0x0080; + const IRUSR = 0x0100; + const ISVTX = 0x0200; + const ISGID = 0x0400; + const ISUID = 0x0800; + // These are mutually-exclusive: + const IFIFO = 0x1000; + const IFCHR = 0x2000; + const IFDIR = 0x4000; + const IFBLK = 0x6000; + const IFREG = 0x8000; + const IFLNK = 0xA000; + const IFSOCK = 0xC000; + } +} + +impl InodeMode { + #[allow(unused)] + pub(crate) fn exec_other(&self) -> bool { + self.0 & Self::IXOTH.0 != 0 + } + #[allow(unused)] + pub(crate) fn write_other(&self) -> bool { + self.0 & Self::IWOTH.0 != 0 + } + #[allow(unused)] + pub(crate) fn read_other(&self) -> bool { + self.0 & Self::IROTH.0 != 0 + } + #[allow(unused)] + pub(crate) fn exec_group(&self) -> bool { + self.0 & Self::IXGRP.0 != 0 + } + #[allow(unused)] + pub(crate) fn write_group(&self) -> bool { + self.0 & Self::IWGRP.0 != 0 + } + #[allow(unused)] + pub(crate) fn read_group(&self) -> bool { + self.0 & Self::IRGRP.0 != 0 + } + #[allow(unused)] + pub(crate) fn exec_user(&self) -> bool { + self.0 & Self::IXUSR.0 != 0 + } + #[allow(unused)] + pub(crate) fn write_user(&self) -> bool { + self.0 & Self::IWUSR.0 != 0 + } + #[allow(unused)] + pub(crate) fn read_user(&self) -> bool { + self.0 & Self::IRUSR.0 != 0 + } + + pub(crate) fn perm(&self) -> u16 { + self.0 & 0x0FFF + } + + pub(crate) fn is_file(&self) -> bool { + (self.0 & 0xF000) == Self::IFREG.0 + } + + pub(crate) fn is_dir(&self) -> bool { + (self.0 & 0xF000) == Self::IFDIR.0 + } + + pub(crate) fn is_symlink(&self) -> bool { + self.0 & 0xF000 == Self::IFLNK.0 + } + + pub(crate) fn validate(mode_value: u16) -> Option<Self> { + let valid_flags: [u16; 7] = [0x1000, 0x2000, 0x4000, 0x6000, 0x8000, 0xA000, 0xC000]; + valid_flags + .contains(&(mode_value & 0xF000)) + .then(|| Self(mode_value)) + } +} + +impl From<InodeMode> for FileType { + fn from(value: InodeMode) -> Self { + let type_flag = value.0 & 0xF000; + match type_flag { + 0x1000 => FileType::NamedPipe, + 0x2000 => FileType::CharDevice, + 0x4000 => FileType::Directory, + 0x6000 => FileType::BlockDevice, + 0x8000 => FileType::RegularFile, + 0xA000 => FileType::Symlink, + 0xC000 => FileType::Socket, + _ => panic!("Invalid inode mode {:x}", type_flag), + } + } +} + +impl From<InodeMode> for u8 { + fn from(value: InodeMode) -> Self { + utils::from_filetype(value.into()) + } +} + +/// Pretty much the same with ext2, with minor changes: +/// - removed OS dependent attributes (osd1 & osd2) +/// - removed i_faddr since fragmentation is not supported +/// - changed uid and gid from u16 to u32 +/// - added more direct blocks for a total size of 128 bytes +/// TODO: do we need to extend time precision? +#[repr(C)] +#[derive(Debug, Clone)] +pub struct Inode { + pub mode: InodeMode, + pub uid: u32, + pub size: u32, + pub atime: u32, // access time, in seconds + pub ctime: u32, // change time, in seconds + pub mtime: u32, // modify time, in seconds + pub crtime: u32, // create time, in seconds + pub gid: u32, + pub n_links: u16, + pub n_blocks: u32, + pub flags: u32, // TODO: do we actually need this? maybe just return 0 + pub direct: [u32; DIRECT_NUMBER], + pub single_indirect: u32, + pub double_indirect: u32, + pub triple_indirect: u32, + pub generation: u32, + pub file_acl: u32, + pub dir_acl: u32, // TODO do we have to implement ACL......? +} + +impl Inode { + fn new( + mode: InodeMode, + uid: u32, + gid: u32, + time: u32, + flags: u32, + generation: u32, + file_acl: u32, + dir_acl: u32, + ) -> Self { + Self { + mode, + uid, + size: 0, + atime: time, + ctime: time, + mtime: time, + crtime: time, + gid, + n_links: 1, + n_blocks: 0, + flags, + direct: [0; DIRECT_NUMBER], + single_indirect: 0, + double_indirect: 0, + triple_indirect: 0, + generation, + file_acl, + dir_acl, + } + } + + #[allow(unused)] + pub fn make_inode( + permissions: u16, + mode: InodeMode, + uid: u32, + gid: u32, + time: u32, + flags: u32, + generation: u32, + file_acl: u32, + dir_acl: u32, + ) -> Self { + Self::new( + InodeMode(permissions) | mode, + uid, + gid, + time, + flags, + generation, + file_acl, + dir_acl, + ) + } + + pub fn directory( + permissions: u16, + uid: u32, + gid: u32, + time: u32, + flags: u32, + generation: u32, + file_acl: u32, + dir_acl: u32, + ) -> Self { + Self::new( + InodeMode(permissions) | InodeMode::IFDIR, + uid, + gid, + time, + flags, + generation, + file_acl, + dir_acl, + ) + } + + pub fn file( + permissions: u16, + uid: u32, + gid: u32, + time: u32, + flags: u32, + generation: u32, + file_acl: u32, + dir_acl: u32, + ) -> Self { + Self::new( + InodeMode(permissions) | InodeMode::IFREG, + uid, + gid, + time, + flags, + generation, + file_acl, + dir_acl, + ) + } + + pub fn symlink( + permissions: u16, + uid: u32, + gid: u32, + time: u32, + flags: u32, + generation: u32, + file_acl: u32, + dir_acl: u32, + ) -> Self { + Self::new( + InodeMode(permissions) | InodeMode::IFLNK, + uid, + gid, + time, + flags, + generation, + file_acl, + dir_acl, + ) + } + + pub(crate) fn is_file(&self) -> bool { + self.mode.is_file() + } + + pub(crate) fn is_dir(&self) -> bool { + self.mode.is_dir() + } + + pub(crate) fn is_symlink(&self) -> bool { + self.mode.is_symlink() + } + + pub(crate) fn file_type(&self) -> FileType { + self.mode.into() + } + + pub fn empty() -> Self { + Self { + mode: InodeMode(0), + uid: 0, + size: 0, + atime: 0, + ctime: 0, + mtime: 0, + crtime: 0, + gid: 0, + n_links: 0, + n_blocks: 0, + flags: 0, + direct: [0; 15], + single_indirect: 0, + double_indirect: 0, + triple_indirect: 0, + generation: 0, + file_acl: 0, + dir_acl: 0, + } + } +} +pub const INODE_SIZE: usize = std::mem::size_of::<Inode>(); +pub const ENTRY_PER_BLOCK: usize = BLOCK_SIZE / 4;
\ No newline at end of file diff --git a/ayafs/src/disk/mod.rs b/ayafs/src/disk/mod.rs new file mode 100644 index 0000000..878e832 --- /dev/null +++ b/ayafs/src/disk/mod.rs @@ -0,0 +1,6 @@ +pub mod allocation; +/// On-disk data structures and logic. +/// Including bitmaps, inodes and blocks. +pub mod bitmap; +pub mod block; +pub mod inode; diff --git a/ayafs/src/filesystem/mod.rs b/ayafs/src/filesystem/mod.rs new file mode 100644 index 0000000..1eaa8e8 --- /dev/null +++ b/ayafs/src/filesystem/mod.rs @@ -0,0 +1,2 @@ +/// Where upper filesystem calls are implemented. +pub mod trait_impl; diff --git a/ayafs/src/filesystem/trait_impl.rs b/ayafs/src/filesystem/trait_impl.rs new file mode 100644 index 0000000..1c40b92 --- /dev/null +++ b/ayafs/src/filesystem/trait_impl.rs @@ -0,0 +1,1247 @@ +use crate::block_device::BLOCK_SIZE; +use crate::disk::block::DataBlock; +use crate::disk::inode::InodeMode; +use crate::utils::permissions::{check_access, clear_suid_sgid, get_groups}; +use crate::utils::{from_filetype, from_systime, time_now, to_fileattr, to_filetype}; +use crate::{AyaFS, TTL}; +use fuser::TimeOrNow::{Now, SpecificTime}; +use fuser::{ + FileType, Filesystem, KernelConfig, ReplyAttr, ReplyData, ReplyDirectory, ReplyEmpty, + ReplyEntry, ReplyOpen, ReplyWrite, Request, TimeOrNow, +}; +use libc::{c_int, EACCES, EBADF, EEXIST, EINVAL, EIO, EISDIR, ENAMETOOLONG, ENOENT, ENOSPC, ENOTDIR, ENOTEMPTY, EPERM, IPOPT_OFFSET, O_ACCMODE, O_RDONLY, O_RDWR, O_WRONLY, R_OK, S_ISGID, S_ISUID, S_IXGRP, S_IXOTH, S_IXUSR, W_OK, RENAME_NOREPLACE, RENAME_EXCHANGE}; +use log::debug; +use std::ffi::OsStr; +use std::os::unix::ffi::OsStrExt; +use std::path::Path; +use std::slice; +use std::time::SystemTime; + +impl AyaFS {} + +impl Filesystem for AyaFS { + fn init(&mut self, _req: &Request<'_>, _config: &mut KernelConfig) -> Result<(), c_int> { + debug!("`init()"); + Ok(()) + } + + fn destroy(&mut self) { + debug!("destroy()"); + // TODO 写回 + } + + fn lookup(&mut self, req: &Request<'_>, parent: u64, name: &OsStr, reply: ReplyEntry) { + if name.len() > 255 { + reply.error(ENAMETOOLONG); + return; + } + + let parent = parent as usize; + if let Some(parent_inode) = self.get_inode(parent) { + if check_access( + req.uid(), + req.gid(), + parent_inode.uid, + parent_inode.gid, + parent_inode.mode, + R_OK, + ) { + let parent_inode = parent_inode.clone(); + match self.lookup_name(parent, &parent_inode, name) { + Ok((inode_index, _, inode)) => { + let attr = to_fileattr(inode_index as usize, &inode); + reply.entry(&TTL, &attr, 0); + } + Err(err_code) => reply.error(err_code), + }; + } else { + reply.error(EACCES); + } + } else { + reply.error(ENOENT); + } + } + + fn getattr(&mut self, _req: &Request<'_>, ino: u64, reply: ReplyAttr) { + if let Some(inode) = self.get_inode(ino as usize) { + reply.attr(&TTL, &to_fileattr(ino as usize, inode)); + } else { + reply.error(ENOENT); + } + } + + fn setattr( + &mut self, + req: &Request<'_>, + ino: u64, + mode: Option<u32>, + uid: Option<u32>, + gid: Option<u32>, + size: Option<u64>, // 当 setattr 被 ftruncate invoke 时会设置 size + atime: Option<TimeOrNow>, + mtime: Option<TimeOrNow>, + _ctime: Option<SystemTime>, + fh: Option<u64>, // 当 setattr 被 ftruncate invoke 时会提供 fh + _crtime: Option<SystemTime>, // 忽略 + _chgtime: Option<SystemTime>, // 忽略 + _bkuptime: Option<SystemTime>, // 忽略 + _flags: Option<u32>, // 忽略 + reply: ReplyAttr, + ) { + if let Some(inode) = self.get_inode_mut(ino as usize) { + // chmod + if let Some(mode) = mode { + debug!("chmod on inode {:#x?} mode {:o}", ino, mode); + if req.uid() != 0 && req.uid() != inode.uid { + reply.error(EPERM); + return; + } // uid == 0 (root) or uid == inode.uid (user itself) + + if req.uid() != 0 + && req.gid() != inode.gid + && !get_groups(req.pid()).contains(&inode.gid) + { + inode.mode = InodeMode((mode & !S_ISGID) as u16); + } else { + inode.mode = InodeMode(mode as u16); + } + + inode.ctime = time_now(); + reply.attr(&TTL, &to_fileattr(ino as usize, inode)); + return; + } + + // chown + if uid.is_some() || gid.is_some() { + debug!("chown on inode {:#x?} uid {:?} gid {:?}", ino, uid, gid); + if let Some(uid) = uid { + // 虽然只有 root 可以 chown 但是 user chown 自己也是不报错的 + if req.uid() != 0 && !(uid == inode.uid && uid == req.uid()) { + reply.error(EPERM); + return; + } + } + if let Some(gid) = gid { + // 只有 root 和 file owner 才可以 chgrp + if req.uid() != 0 && req.uid() != inode.uid { + reply.error(EPERM); + return; + } + // root 可以任意 chgrp, 非 root 只能修改到用户自己所在的组里 + if req.gid() != 0 && !get_groups(req.pid()).contains(&gid) { + reply.error(EPERM); + return; + } + } + + // 可执行文件要清除 suid & sgid + if inode.mode.0 & (S_IXUSR | S_IXGRP | S_IXOTH) as u16 != 0 { + inode.mode = clear_suid_sgid(inode.mode); + } + + // chown 要清除 suid + if let Some(uid) = uid { + inode.uid = uid; + inode.mode.0 &= !S_ISUID as u16; + } + + if let Some(gid) = gid { + inode.gid = gid; + if req.uid() != 0 { + inode.mode.0 &= !S_ISGID as u16; + } + } + inode.ctime = time_now(); + reply.attr(&TTL, &to_fileattr(ino as usize, inode)); + return; + } + + // ftruncate + if let Some(size) = size { + // TODO 当大小减小的时候对应 deallocate 块 + debug!("ftruncate on inode {:#x?} size {:?}", ino, size); + if let Some(file_handle) = fh { + let mut inode = inode.clone(); + let (inode_index, _read, write) = + self.file_handle_map.get(&file_handle).unwrap(); + assert_eq!(ino as usize, *inode_index); + if !write { + reply.error(EACCES); + } else { + inode.size = size as u32; + reply.attr(&TTL, &to_fileattr(*inode_index, &inode)); + self.update_inode(*inode_index, inode); + } + } else { + if !check_access(req.uid(), req.gid(), inode.uid, inode.gid, inode.mode, W_OK) { + reply.error(EACCES); + } else { + inode.size = size as u32; + reply.attr(&TTL, &to_fileattr(ino as usize, &inode)); + } + } + return; + } + + // time 相关 + if atime.is_some() || mtime.is_some() { + let current_time = time_now(); + if let Some(atime) = atime { + debug!("utimensat on inode {:#x?}, atime {:?}", ino, atime); + // root 和 user 可以随意修改 atime, 其他用户只能 touch (即 atime == Now) + if req.uid() != 0 && req.uid() != inode.uid && atime != Now { + reply.error(EPERM); + return; + } + + if req.uid() != 0 + && req.uid() != inode.uid + && check_access( + req.uid(), + req.gid(), + inode.uid, + inode.gid, + inode.mode, + R_OK, // atime 来说是 read TODO 对吗 + ) + { + reply.error(EACCES); + return; + } + + inode.atime = match atime { + SpecificTime(time) => from_systime(time), + Now => current_time, + }; + inode.ctime = current_time; + } + if let Some(mtime) = mtime { + debug!("utimensat on inode {:#x?}, mtime {:?}", ino, mtime); + // root 和 user 可以随意修改 mtime, 其他用户只能 mtime == Now + if req.uid() != 0 && req.uid() != inode.uid && mtime != Now { + reply.error(EPERM); + return; + } + + if req.uid() != 0 + && req.uid() != inode.uid + && check_access( + req.uid(), + req.gid(), + inode.uid, + inode.gid, + inode.mode, + W_OK, // mtime 来说是 write + ) + { + reply.error(EACCES); + return; + } + + inode.mtime = match mtime { + SpecificTime(time) => from_systime(time), + Now => current_time, + }; + inode.ctime = current_time; + } + } + reply.attr(&TTL, &to_fileattr(ino as usize, inode)); + return; + } else { + reply.error(ENOENT); + } + } + + // 这啥语义啊?? + fn readlink(&mut self, req: &Request<'_>, ino: u64, reply: ReplyData) { + debug!("readlink(ino: {})", ino); + if let Some(inode) = self.get_inode(ino as usize) { + if !inode.is_symlink() { + reply.error(ENOENT); + return; + } + if !check_access(req.uid(), req.gid(), inode.uid, inode.gid, inode.mode, R_OK) { + reply.error(EACCES); + return; + } + let path_length = inode.size as usize; + let mut path = vec![0u8; path_length]; + if path_length < 60 { + debug!( + "symlink path length is {}, reading directly from inode.direct", + path_length + ); + let copy_src = unsafe { + let src = (&inode.direct) as *const u32 as *const u8; + slice::from_raw_parts(src, path_length) + }; + path.as_mut_slice().copy_from_slice(copy_src); + } else { + debug!( + "symlink path length is {}, using original read", + path_length + ); + let inode = inode.clone(); + let mut read_ptr = 0usize; + while read_ptr < path_length { + let block_index = read_ptr / BLOCK_SIZE; + let offset = read_ptr % BLOCK_SIZE; + + let read_length_within_block = if BLOCK_SIZE - offset < path_length - read_ptr { + BLOCK_SIZE - offset + } else { + path_length - read_ptr + }; + + if let Some(block) = self.access_block::<DataBlock>(&inode, block_index) { + (&mut path[read_ptr..read_ptr + read_length_within_block]).copy_from_slice( + &block.block.0[offset..offset + read_length_within_block], + ); + read_ptr += read_length_within_block; + } else { + reply.error(EIO); + return; + } + } + } + debug!( + "readlink path read is {:?}", + OsStr::from_bytes(path.as_slice()) + ); + reply.data(path.as_slice()); + } else { + reply.error(ENOENT); + } + } + + fn mknod( + &mut self, + req: &Request<'_>, + parent: u64, + name: &OsStr, + mode: u32, + _umask: u32, // umask 是用不到的 + _rdev: u32, // the device number (only valid if created file is a device) + reply: ReplyEntry, + ) { + debug!( + "mknod(parent: {}, name: {:?}, mode: {}, umask: {})", + parent, name, mode, _umask + ); + + let parent = parent as usize; + if let Some(parent_inode) = self.get_inode(parent) { + if !check_access( + req.uid(), + req.gid(), + parent_inode.uid, + parent_inode.gid, + parent_inode.mode, + W_OK, + ) { + reply.error(EACCES); + return; + } + + // parent 不是 IFDIR -> Not a directory + if !parent_inode.is_dir() { + reply.error(ENOTDIR); + return; + } + + // 文件名长度超过 255, 返回 filename too long + if name.len() > 255 { + reply.error(ENAMETOOLONG); + return; + } + + let mut parent_inode = parent_inode.clone(); + // 如果已经存在, 返回 already exists + if self.lookup_name(parent, &parent_inode, name).is_ok() { + reply.error(EEXIST); + return; + } + + let mode = mode as u16; + if let Some((child_inode_index, child_inode)) = + self.create_file(mode, req.uid(), req.gid(), 0) + { + let mode = child_inode.mode; + let file_attr = to_fileattr(child_inode_index, child_inode); + if let Err(err_code) = self.add_direntry( + parent, + &mut parent_inode, + child_inode_index, + name, + mode.into(), + ) { + reply.error(err_code); + return; + } + self.update_inode(parent, parent_inode); // 前面 clone 了, 这里写回 + reply.entry(&TTL, &file_attr, 0); + } else { + // create_inode 失败 -> no enough space + reply.error(ENOSPC); + } + } else { + // parent 不存在 -> No such file or directory + reply.error(ENOENT); + } + } + + fn mkdir( + &mut self, + req: &Request<'_>, + parent: u64, + name: &OsStr, + mode: u32, + _umask: u32, // umask 应该也是用不到的 + reply: ReplyEntry, + ) { + if let Some(parent_inode) = self.get_inode(parent as usize) { + // 无权限创建 -> EACCES + if !check_access( + req.uid(), + req.gid(), + parent_inode.uid, + parent_inode.gid, + parent_inode.mode, + W_OK, + ) { + reply.error(EACCES); + return; + } + + // parent 不是 IFDIR -> Not a directory + if !parent_inode.is_dir() { + reply.error(ENOTDIR); + return; + } + + // 文件名长度超过 255 -> filename too long + if name.len() > 255 { + reply.error(ENAMETOOLONG); + return; + } + + let mut parent_inode = parent_inode.clone(); + // 已经存在 -> File exists + if self + .lookup_name(parent as usize, &parent_inode, name) + .is_ok() + { + reply.error(EEXIST); + return; + } + + let mode = mode as u16; + if let Some((child_inode_index, child_inode)) = + self.create_directory(mode, req.uid(), req.gid(), 0, Some(parent as usize)) + { + let child_inode = child_inode.clone(); + let file_attr = to_fileattr(child_inode_index, &child_inode); + if let Err(err_code) = self.add_direntry( + parent as usize, + &mut parent_inode, + child_inode_index, + name, + child_inode.mode.into(), + ) { + reply.error(err_code); + return; + } + self.update_inode(parent as usize, parent_inode); // 前面 clone 了, 这里写回 + reply.entry(&TTL, &file_attr, 0); + } else { + // create_inode 失败 -> no enough space + reply.error(ENOSPC); + } + } else { + // parent 不存在 -> No such file or directory + reply.error(ENOENT); + } + } + + fn unlink(&mut self, req: &Request<'_>, parent: u64, name: &OsStr, reply: ReplyEmpty) { + debug!("unlink(parent: {:#x?}, name: {:?})", parent, name,); + if let Some(parent_inode) = self.get_inode(parent as usize) { + // 无权限删除 -> EACCES + if !check_access( + req.uid(), + req.gid(), + parent_inode.uid, + parent_inode.gid, + parent_inode.mode, + W_OK, + ) { + reply.error(EACCES); + return; + } + + // parent 不是 dir -> ENOTDIR + if !parent_inode.is_dir() { + reply.error(ENOTDIR); + return; + } + + // 文件名长度超过 255 -> filename too long + if name.len() > 255 { + reply.error(ENAMETOOLONG); + return; + } + + let mut parent_inode = parent_inode.clone(); + // 不存在 -> No such file or directory + if let Ok((inode_index, entry_index, mut inode)) = + self.lookup_name(parent as usize, &parent_inode, name) + { + let inode_index = inode_index as usize; + + match inode.file_type() { + FileType::RegularFile => { + inode.n_links -= 1; + if inode.n_links == 0 { + // n_links == 0 -> 整个 inode 都要删除掉 + match self.remove_file(inode_index) { + Ok(flag) => debug!(" unlink {}", flag), + Err(err_code) => { + reply.error(err_code); + return; + } + } + } else { + // n_links > 0 -> 只是移除了一个 hard link, 将改动写回 + self.update_inode(inode_index, inode); + } + } + FileType::Symlink => {} + FileType::Directory => { + reply.error(EISDIR); + return; + } + _ => { + // Not implemented! + reply.error(EIO); + return; + } + } + + // 删除 dir entry + if let Err(err_code) = + self.remove_direntry(parent as usize, &mut parent_inode, name, entry_index) + { + reply.error(err_code); + return; + } + reply.ok(); + } else { + reply.error(ENOENT); + } + } else { + reply.error(ENOENT); + } + } + + fn rmdir(&mut self, req: &Request<'_>, parent: u64, name: &OsStr, reply: ReplyEmpty) { + debug!("rmdir(parent: {:#x?}, name: {:?}", parent, name,); + if let Some(parent_inode) = self.get_inode(parent as usize) { + // 无权限删除 -> EACCES + if !check_access( + req.uid(), + req.gid(), + parent_inode.uid, + parent_inode.gid, + parent_inode.mode, + W_OK, + ) { + reply.error(EACCES); + return; + } + + // parent 不是 dir -> ENOTDIR + if !parent_inode.is_dir() { + reply.error(ENOTDIR); + return; + } + + // 文件名长度超过 255 -> filename too long + if name.len() > 255 { + reply.error(ENAMETOOLONG); + return; + } + + let mut parent_inode = parent_inode.clone(); + // 不存在 -> No such file or directory + if let Ok((inode_index, entry_index, inode)) = + self.lookup_name(parent as usize, &parent_inode, name) + { + let inode_index = inode_index as usize; + // 要删除的 entry 是一般文件, 不用 rmdir + if inode.is_file() { + reply.error(ENOTDIR); + return; + } + + // 一定有 . 和 .. 所以 size == 2 就是空目录 + // 目录非空 -> ENOTEMPTY + if inode.size > 2 { + reply.error(ENOTEMPTY); + return; + } + + // directory 没有 hard link, 删了就是删了 + match self.remove_dir(inode_index) { + Ok(flag) => debug!(" rmdir {}", flag), + Err(err_code) => { + reply.error(err_code); + return; + } + } + + // 删除 dir entry + if let Err(err_code) = + self.remove_direntry(parent as usize, &mut parent_inode, name, entry_index) + { + reply.error(err_code); + return; + } + + reply.ok(); + } else { + reply.error(ENOENT); + } + } else { + reply.error(ENOENT); + } + } + + fn symlink( + &mut self, + req: &Request<'_>, + parent: u64, + link_name: &OsStr, + target: &Path, + reply: ReplyEntry, + ) { + debug!( + "symlink(parent: {}, name: {:?}, target: {:?})", + parent, link_name, target + ); + let parent = parent as usize; + + // let root_inode_index = 1usize; + // if let Some(root_inode) = self.get_inode(root_inode_index) { + // let mut curr_inode_index = root_inode_index; + // let mut curr_inode = root_inode.clone(); + // for segment in target.iter() { + // match self.lookup_name(curr_inode_index, &curr_inode, segment) { + // Ok((next_inode_index, _, next_inode)) => { + // curr_inode_index = next_inode_index as usize; + // curr_inode = next_inode; + // } + // Err(err_code) => { + // reply.error(err_code); + // return; + // } + // } + // } + // } else { + // reply.error(EIO); + // return; + // } + + if let Some(parent_inode) = self.get_inode(parent) { + if !check_access( + req.uid(), + req.gid(), + parent_inode.uid, + parent_inode.gid, + parent_inode.mode, + W_OK, + ) { + reply.error(EACCES); + return; + } + + if !parent_inode.is_dir() { + reply.error(ENOTDIR); + return; + } + + if link_name.len() > 255 { + reply.error(ENAMETOOLONG); + return; + } + + let target = target.as_os_str(); + let mut parent_inode = parent_inode.clone(); + if self.lookup_name(parent, &parent_inode, link_name).is_ok() { + reply.error(EEXIST); + return; + } + + if let Some((child_inode_index, child_inode)) = + self.create_symlink(0o777, req.uid(), req.gid(), 0) + { + let mut child_inode = child_inode.clone(); + child_inode.size = target.len() as u32; + if target.len() < 60 { + debug!("create_symlink: target length < 60, allocating in 'direct' section."); + let target_path = target.as_bytes(); + let copy_dst = unsafe { + let dst = (&mut child_inode.direct) as *mut u32 as *mut u8; + slice::from_raw_parts_mut(dst, target_path.len()) + }; + copy_dst.copy_from_slice(target_path); + } else { + debug!("create_symlink: target length >= 60, using original layout."); + let mut write_ptr = 0usize; + while write_ptr < target.len() { + let block_index = write_ptr / BLOCK_SIZE; + let offset = write_ptr % BLOCK_SIZE; + + let write_length_within_block = + if BLOCK_SIZE - offset < target.len() - write_ptr { + BLOCK_SIZE - offset + } else { + target.len() - write_ptr + }; + + if let Some(block) = + self.access_block_mut::<DataBlock>(&child_inode, block_index) + { + block.block.0[offset..offset + write_length_within_block] + .copy_from_slice( + &target.as_bytes() + [write_ptr..write_ptr + write_length_within_block], + ); + write_ptr += write_length_within_block; + } else { + if let Some((_block_index, block_index_within_inode)) = + self.allocate_block_for(&mut child_inode) + { + let block = self + .access_block_mut::<DataBlock>( + &child_inode, + block_index_within_inode, + ) + .unwrap(); + block.block.0[offset..offset + write_length_within_block] + .copy_from_slice( + &target.as_bytes() + [write_ptr..write_ptr + write_length_within_block], + ); + write_ptr += write_length_within_block; + } else { + reply.error(ENOSPC); + return; + } + } + } + } + + let file_attr = to_fileattr(child_inode_index, &child_inode); + self.update_inode(child_inode_index, child_inode); + + if let Err(err_code) = self.add_direntry( + parent, + &mut parent_inode, + child_inode_index, + link_name, + from_filetype(FileType::Symlink), + ) { + reply.error(err_code); + return; + } + self.update_inode(parent, parent_inode); + reply.entry(&TTL, &file_attr, 0); + } else { + reply.error(ENOSPC); + } + } else { + reply.error(ENOENT); + } + } + + fn rename( + &mut self, + req: &Request<'_>, + parent: u64, + name: &OsStr, + new_parent: u64, + new_name: &OsStr, + flags: u32, + reply: ReplyEmpty, + ) { + debug!( + "rename(parent: {}, name: {:?}, new_parent: {}, new_name: {:?})", + parent, name, new_parent, new_name + ); + + let parent = parent as usize; + let new_parent = new_parent as usize; + if let Some(parent_inode) = self.get_inode(parent) { + if !check_access( + req.uid(), + req.gid(), + parent_inode.uid, + parent_inode.gid, + parent_inode.mode, + R_OK, + ) { + reply.error(EACCES); + return; + } + + if name.len() > 255 { + reply.error(ENAMETOOLONG); + return; + } + + let mut parent_inode = parent_inode.clone(); + match self.lookup_name(parent, &parent_inode, name) { + Ok((inode_index, entry_index, inode)) => { + if let Some(new_parent_inode) = self.get_inode(new_parent) { + if !check_access( + req.uid(), + req.gid(), + new_parent_inode.uid, + new_parent_inode.gid, + new_parent_inode.mode, + W_OK, + ) { + reply.error(EACCES); + return; + } + if new_name.len() > 255 { + reply.error(ENAMETOOLONG); + return; + } + + let mut new_parent_inode = new_parent_inode.clone(); + match self.lookup_name(new_parent, &new_parent_inode, new_name) { + Ok((new_inode_index, new_entry_index, new_inode)) => { + // 新文件存在 + if flags & RENAME_NOREPLACE != 0 { // 指定 noreplace 之后不允许覆盖文件 + reply.error(EEXIST); + return; + } + if flags & RENAME_EXCHANGE != 0 { // 交换两个文件 + if let Err(err_code) = self.exchange_direntry( + parent, + &mut parent_inode, + name, + new_parent, + &mut new_parent_inode, + new_name + ) { + reply.error(err_code); + return; + } + } else { // 用新文件替换旧文件 + let dir_entry = self.get_direntry_by_name(parent, &parent_inode, name) + .unwrap(); + if let Err(err_code) = self.remove_direntry(parent, &mut parent_inode, name, entry_index) { + reply.error(err_code); + return; + } + if let Err(err_code) = self.remove_direntry(new_parent, &mut new_parent_inode, new_name, new_entry_index) { + reply.error(err_code); + return; + } + if let Err(err_code) = self.add_direntry_2(new_parent, &mut new_parent_inode, new_name, dir_entry) { + reply.error(err_code); + return; + } + } + reply.ok(); + }, + Err(ENOENT) => { // 新文件不存在, 删除旧的创建新的 + let dir_entry = self.get_direntry_by_name(parent, &parent_inode, name) + .unwrap(); + if let Err(err_code) = self.remove_direntry(parent, &mut parent_inode, name, entry_index) { + reply.error(err_code); + return; + } + if let Err(err_code) = self.add_direntry_2(new_parent, &mut new_parent_inode, new_name, dir_entry) { + reply.error(err_code); + return; + } + reply.ok(); + }, + Err(err_code) => { + // 其他 Err code + reply.error(err_code); + return; + } + } + } else { + reply.error(ENOENT); + } + }, + Err(err_code) => { + reply.error(err_code); + return; + } + } + } else { + reply.error(ENOENT); + } + } + + fn open(&mut self, req: &Request<'_>, ino: u64, flags: i32, reply: ReplyOpen) { + debug!("open(ino: {:#x?}, flags: {:#x?})", ino, flags); + let (access_mask, read, write) = match flags & O_ACCMODE { + O_RDONLY => { + // Behavior is undefined, but most filesystems return EACCES + if flags & libc::O_TRUNC != 0 { + reply.error(EACCES); + return; + } + (R_OK, true, false) + } + O_WRONLY => (W_OK, false, true), + O_RDWR => (R_OK | W_OK, true, true), + _ => { + // flag 非法 + reply.error(EINVAL); + return; + } + }; + + match self.get_inode(ino as usize) { + Some(inode) => { + if !check_access( + req.uid(), + req.gid(), + inode.uid, + inode.gid, + inode.mode, + access_mask, + ) { + reply.error(EACCES); + return; + } + let fd = self.allocate_file_descriptor(ino as usize, read, write); + reply.opened(fd, 0); + } + None => { + reply.error(ENOENT); + } + } + } + + // read [offset, offset + size) + // - EOF < offset + size -> return EOF - offset + // - EOF > offset + size -> return size + fn read( + &mut self, + req: &Request<'_>, + ino: u64, + fh: u64, + offset: i64, + size: u32, + _flags: i32, + _lock_owner: Option<u64>, // 用不到! + reply: ReplyData, + ) { + assert_eq!(self.file_handle_map.get(&fh).unwrap().0, ino as usize); + if let Some(inode) = self.get_inode(ino as usize) { + if inode.is_dir() { + reply.error(EISDIR); + return; + } + if !check_access(req.uid(), req.gid(), inode.uid, inode.gid, inode.mode, R_OK) { + reply.error(EACCES); + return; + } + debug!("reading inode {:#x} (offset {} size {})", ino, offset, size); + + if offset as u32 >= inode.size { + // offset 在 EOF 后面, 直接返回一个 0 长度的空 buffer + reply.data(&Vec::new()); + return; + } + + // let read_length = size.min(inode.size.saturating_sub(offset as u32)) as usize; + // 这和下面那个是等同的但是不利于让人看懂…… + let read_length = if offset as u32 + size <= inode.size { + size // 没有越过 EOF, 读取 size 个 byte + } else { + inode.size - offset as u32 // 越过了 EOF, 读取 inode.size - offset 个 byte + } as usize; + + let mut read_buffer = vec![0u8; read_length]; + let mut read_ptr = 0usize; + + let inode = inode.clone(); + + while read_ptr < read_length { + let current_point = offset as usize + read_ptr; + let current_block_index = current_point / BLOCK_SIZE; + let current_offset = current_point % BLOCK_SIZE; + + let read_length_within_block = + if BLOCK_SIZE - current_offset < read_length - read_ptr { + BLOCK_SIZE - current_offset // 可以读到 block 最后 + } else { + read_length - read_ptr // 读到中途会停下来 + }; + + if let Some(block) = self.access_block::<DataBlock>(&inode, current_block_index) { + (&mut read_buffer[read_ptr..read_ptr + read_length_within_block]) + .copy_from_slice( + &block.block.0 + [current_offset..current_offset + read_length_within_block], + ); + read_ptr += read_length_within_block; + } else { + reply.error(EIO); + return; + } + } + + reply.data(&read_buffer); + } + } + + // 写了多少就返回多少 + fn write( + &mut self, + req: &Request<'_>, + ino: u64, + fh: u64, + offset: i64, + data: &[u8], + _write_flags: u32, + _flags: i32, + _lock_owner: Option<u64>, + reply: ReplyWrite, + ) { + assert_eq!(self.file_handle_map.get(&fh).unwrap().0, ino as usize); + if let Some(inode) = self.get_inode(ino as usize) { + if inode.is_dir() { + reply.error(EISDIR); + return; + } + if !check_access(req.uid(), req.gid(), inode.uid, inode.gid, inode.mode, W_OK) { + reply.error(EACCES); + return; + } + debug!( + "writing inode {:#x} (offset {} size {})", + ino, + offset, + data.len() + ); + let write_length = data.len(); + let mut write_ptr = 0usize; + + let mut inode = inode.clone(); + + while write_ptr < write_length { + let current_point = offset as usize + write_ptr; + let current_block_index = current_point / BLOCK_SIZE; + let current_offset = current_point % BLOCK_SIZE; + + let write_length_within_block = + if BLOCK_SIZE - current_offset < write_length - write_ptr { + BLOCK_SIZE - current_offset // 可以写满 block + } else { + write_length - write_ptr // 写完 buffer 就停下来 + }; + + // 当前块已分配, 直接往里写 + if let Some(block) = self.access_block_mut::<DataBlock>(&inode, current_block_index) + { + debug!( + "writing {} bytes in block {} within inode", + write_length_within_block, current_block_index + ); + (block.block.0[current_offset..current_offset + write_length_within_block]) + .copy_from_slice(&data[write_ptr..write_ptr + write_length_within_block]); + write_ptr += write_length_within_block; + } else { + // 当前块未分配，尝试分配 + if let Some((block_index, block_index_within_inode)) = + self.allocate_block_for(&mut inode) + { + debug!("writing {} bytes in allocated block {} within inode, block index is {}", write_length_within_block, block_index_within_inode, block_index); + // 能分配, 往里写 + let block = self + .access_block_mut::<DataBlock>(&inode, block_index_within_inode) + .unwrap(); + (block.block.0[current_offset..current_offset + write_length_within_block]) + .copy_from_slice( + &data[write_ptr..write_ptr + write_length_within_block], + ); + write_ptr += write_length_within_block; + } else { + // 分配不了, 没空间了 + break; + } + } + } + + inode.size = inode.size.max(offset as u32 + write_length as u32); + self.update_inode(ino as usize, inode); + reply.written(write_length as u32); + } else { + reply.error(ENOENT); + } + } + + fn release( + &mut self, + _req: &Request<'_>, + ino: u64, + fh: u64, + _flags: i32, + _lock_owner: Option<u64>, + _flush: bool, + reply: ReplyEmpty, + ) { + debug!("release(ino: {:#x?}, fh: {}", ino, fh); + if self.file_handle_map.contains_key(&fh) { + self.file_handle_map.remove(&fh); + reply.ok(); + } else { + reply.error(EBADF); + } + } + + fn opendir(&mut self, req: &Request<'_>, ino: u64, flags: i32, reply: ReplyOpen) { + debug!("opendir(ino: {:#x?}, flags: {:#x?})", ino, flags); + let (access_mask, read, write) = match flags & O_ACCMODE { + O_RDONLY => { + // Behavior is undefined, but most filesystems return EACCES + if flags & libc::O_TRUNC != 0 { + reply.error(EACCES); + return; + } + (R_OK, true, false) + } + O_WRONLY => (W_OK, false, true), + O_RDWR => (R_OK | W_OK, true, true), + _ => { + // flag 非法 + reply.error(EINVAL); + return; + } + }; + + match self.get_inode(ino as usize) { + Some(inode) => { + if !check_access( + req.uid(), + req.gid(), + inode.uid, + inode.gid, + inode.mode, + access_mask, + ) { + reply.error(EACCES); + return; + } + let fd = self.allocate_file_descriptor(ino as usize, read, write); + reply.opened(fd, 0); + } + None => { + reply.error(ENOENT); + } + } + } + + fn readdir( + &mut self, + req: &Request<'_>, + ino: u64, + fh: u64, // 如果 invoke 它的 opendir 里有指定 fh, 那么这里会收到 fh 参数 + offset: i64, + mut reply: ReplyDirectory, + ) { + assert_eq!(self.file_handle_map.get(&fh).unwrap().0, ino as usize); + if let Some(inode) = self.get_inode(ino as usize) { + if !inode.is_dir() { + reply.error(ENOTDIR); + return; + } + + if !check_access(req.uid(), req.gid(), inode.uid, inode.gid, inode.mode, R_OK) { + reply.error(EACCES); + return; + } + + debug!( + "reading dir entries from inode {:#x} with offset {}", + ino, offset + ); + let inode = inode.clone(); + + self.load_direntry_map(ino as usize, &inode).unwrap(); + for (entry_index, (name, dir_entry)) in self + .dir_entry_map + .get(&(ino as usize)) + .unwrap() + .iter() + .enumerate() + .skip(offset as usize) + { + debug!( + " entry {} from inode {:#x} with name {:?}", + entry_index, dir_entry.inode, name + ); + if reply.add( + dir_entry.inode as u64, + entry_index as i64 + 1, + to_filetype(dir_entry.file_type).expect("not 0x0!"), + name, + ) { + break; + } + } + + reply.ok(); + } else { + reply.error(ENOENT); + } + } + + fn releasedir( + &mut self, + _req: &Request<'_>, + ino: u64, + fh: u64, + _flags: i32, + reply: ReplyEmpty, + ) { + debug!("releasedir(ino: {:#x?}, fh: {}", ino, fh); + if self.file_handle_map.contains_key(&fh) { + self.file_handle_map.remove(&fh); + reply.ok(); + } else { + reply.error(EBADF); + } + } + + fn access(&mut self, req: &Request<'_>, ino: u64, mask: i32, reply: ReplyEmpty) { + // mask: + // - 要么是 libc::F_OK (aka 0), 检查文件是否存在 + // - 要么是 libc::R_OK,libc::W_OK,libc::X_OK (aka 4/2/1) 构成的 bitmask, 检查是否有对应权限 + debug!("Filesystem::access(ino: {}, mask: {})", ino, mask); + + if let Some(inode) = self.get_inode(ino as usize) { + if mask == libc::F_OK // 只要检查是否存在 + || check_access(req.uid(), req.gid(), inode.uid, inode.gid, inode.mode, mask) + // 需要检查 rwx 权限 + { + reply.ok(); + } else { + reply.error(EACCES); + } + } else { + reply.error(ENOENT); + } + } +} diff --git a/ayafs/src/main.rs b/ayafs/src/main.rs new file mode 100644 index 0000000..db4a017 --- /dev/null +++ b/ayafs/src/main.rs @@ -0,0 +1,171 @@ +mod block_device; +mod disk; +mod filesystem; +mod memory; +mod tests; +mod utils; + +use clap::Parser; +use fuser::MountOption; +use indexmap::IndexMap; +use log::{debug, LevelFilter}; +use lru::LruCache; +use std::collections::HashMap; +use std::ffi::OsString; +use std::num::NonZeroUsize; +use std::path::PathBuf; +use std::sync::atomic::AtomicU64; +use std::sync::Arc; +use std::time::Duration; + +use crate::disk::block::{DirectoryEntry, InodeBlock}; +use crate::memory::cached_block::BlockCache; +use block_device::{memory_disk::MemoryDisk, BlockDevice, BLOCK_SIZE}; +use disk::bitmap::Bitmap; +use disk::block::DataBlock; +use disk::inode::INODE_SIZE; +use users::{get_current_gid, get_current_uid}; +use crate::block_device::disk::Disk; + +#[derive(Parser, Debug)] +#[command(author, version, about)] +struct Args { + mount_point: Option<String>, + #[arg(short, action = clap::ArgAction::Count)] + verbosity: u8, + #[arg(long)] + auto_unmount: bool, + #[arg(long)] + allow_root: bool, +} + +const TTL: Duration = Duration::new(0, 0); +const INODE_PER_BLOCK: usize = BLOCK_SIZE / INODE_SIZE; + +/// The design of MyFS is rather simple: +/// +-------------------+ +/// | Super Block | +/// +-------------------+ +/// | Inode Bitmap | +/// +-------------------+ +/// | ... | +/// +-------------------+ +/// | Data Block Bitmap | +/// +-------------------+ +/// | ... | +/// +-------------------+ +/// | Inode Block | +/// +-------------------+ +/// | ... | +/// +-------------------+ +/// | Data Block | +/// +-------------------+ +/// With each block 4KiB, each Inode entry 128B + +#[repr(C)] +struct AyaFS { + device: Arc<dyn BlockDevice>, + data_bitmap: Bitmap, + inode_bitmap: Bitmap, + inode_start_block: usize, + data_start_block: usize, + + next_file_handle: AtomicU64, + // file descriptor -> (inode index, read, write) + file_handle_map: HashMap<u64, (usize, bool, bool)>, + + // inode index -> (index aware) hashmap that maps dir entry name to inode index + dir_entry_map: LruCache<usize, IndexMap<OsString, DirectoryEntry>>, + + cached_inodes: BlockCache<InodeBlock>, + cached_blocks: BlockCache<DataBlock>, +} + +impl AyaFS { + fn new(device: Arc<dyn BlockDevice>, total_block_number: usize) -> Self { + let max_inode_number: usize = 16384; // TODO: remove hard-coded magic number + let inode_block_number = max_inode_number / INODE_PER_BLOCK; // == 128 + let inode_bitmap_block_number = (inode_block_number + BLOCK_SIZE - 1) / BLOCK_SIZE; + + let blocks_remaining = + total_block_number - inode_block_number - inode_bitmap_block_number - 1; + // let number of data blocks be x, the remaining block number be C, + // the corresponding data bitmap length should be ceil(x / BLK_SIZE), + // thus we have BLK_SIZE * (C-1) / (BLK_SIZE+1) <= x <= BLK_SIZE * C / (BLK_SIZE+1) + // the difference of the two bounds is less than 1, + // meaning only 1 integer could be in between. + // Thus we have x = floor(BLK_SIZE * C / (BLK_SIZE + 1)) + let data_block_number = BLOCK_SIZE * blocks_remaining / (BLOCK_SIZE + 1); + let data_bitmap_block_number = blocks_remaining - data_block_number; + debug!("data_bitmap_block_number: {}", data_bitmap_block_number); + debug!("inode_bitmap_block_number: {}", inode_bitmap_block_number); + debug!("inode_block_number: {}", inode_block_number); + debug!("data_block_number: {}", data_block_number); + debug!( + "sum: {}", + 1 + data_bitmap_block_number + + inode_bitmap_block_number + + inode_block_number + + data_block_number + ); + + let mut data_bitmap = Bitmap::new(1, data_bitmap_block_number, device.clone()); + let _ = data_bitmap.allocate().unwrap(); // data block 0 is not usable + let mut inode_bitmap = Bitmap::new( + data_bitmap_block_number + 1, + inode_bitmap_block_number, + device.clone(), + ); + let _ = inode_bitmap.allocate().unwrap(); // inode block 0 is not usable + + let mut fs = Self { + device: device.clone(), + data_bitmap, + inode_bitmap, + inode_start_block: data_bitmap_block_number + inode_bitmap_block_number + 1, + data_start_block: data_bitmap_block_number + + inode_bitmap_block_number + + inode_block_number + + 1, + + next_file_handle: AtomicU64::new(3), // 0,1,2 are stdin, stdout and stderr + file_handle_map: HashMap::new(), + + dir_entry_map: LruCache::new(NonZeroUsize::new(1024).unwrap()), + + cached_inodes: BlockCache::new(device.clone(), 1024), + cached_blocks: BlockCache::new(device.clone(), 8192), + }; + + fs.create_directory(0o755, get_current_uid(), get_current_gid(), 0, None); + + fs + } +} + +fn main() { + let args = Args::parse(); + let mount_point = args.mount_point.unwrap(); + let verbosity = args.verbosity; + let log_level = match verbosity { + 0 => LevelFilter::Error, + 1 => LevelFilter::Warn, + 2 => LevelFilter::Info, + 3 => LevelFilter::Debug, + _ => LevelFilter::Trace, + }; + env_logger::builder() + .filter_level(log_level) + .init(); + let options = vec![ + // MountOption::RO, + MountOption::FSName("hello".to_string()), + MountOption::AutoUnmount, + MountOption::AllowRoot, + ]; + let disk = Arc::new(Disk::new(PathBuf::from("/dev/nvme0n1p4"))); + // let disk = Arc::new(MemoryDisk::new(16384)); + let filesystem = AyaFS::new(disk, 7864320); + + fuser::mount2(filesystem, mount_point, &options).unwrap(); +} diff --git a/ayafs/src/memory/cached_block.rs b/ayafs/src/memory/cached_block.rs new file mode 100644 index 0000000..c3d0338 --- /dev/null +++ b/ayafs/src/memory/cached_block.rs @@ -0,0 +1,180 @@ +use crate::block_device::{BlockDevice, BLOCK_SIZE}; +use crate::disk::block::Block; +use crate::AyaFS; +use lru::LruCache; +use std::num::NonZeroUsize; +use std::sync::Arc; + +#[derive(Clone)] +pub struct CachedBlock<T: Block> { + pub block: T, + pub index: usize, + pub dirty: bool, +} + +pub fn convert_mut<U: Block, T: Block>(input_block: &mut CachedBlock<U>) -> &mut CachedBlock<T> { + let ptr = input_block as *const CachedBlock<U> as *mut u8; + let block = ptr.cast::<CachedBlock<T>>(); + unsafe { &mut *block } +} + +pub fn convert<U: Block, T: Block>(input_block: &CachedBlock<U>) -> &CachedBlock<T> { + let ptr = input_block as *const CachedBlock<U> as *mut u8; + let block = ptr.cast::<CachedBlock<T>>(); + unsafe { &*block } +} + +pub(crate) struct BlockCache<T: Block> { + device: Arc<dyn BlockDevice>, + cache: LruCache<usize, CachedBlock<T>>, +} + +impl<T: Block> BlockCache<T> { + pub(crate) fn new(device: Arc<dyn BlockDevice>, cache_size: usize) -> Self { + Self { + device, + cache: LruCache::new(NonZeroUsize::new(cache_size).unwrap()), + } + } + + pub(crate) fn load_block(&mut self, index: usize) -> bool { + if self.cache.contains(&index) == false { + let mut buffer = [0u8; BLOCK_SIZE]; + self.device.read(index, &mut buffer); + let block: T = unsafe { std::mem::transmute_copy(&buffer) }; + let cached_block = CachedBlock { + block, + index, + dirty: false, + }; + if let Some((old_index, old_block)) = self.cache.push(index, cached_block) { + assert_ne!(old_index, index); // 只有 block 不在 cache 里的时候才会插入 + if old_block.dirty { + let old_block_ptr = &old_block.block as *const T as *mut u8; + let old_block_buffer = + unsafe { std::slice::from_raw_parts(old_block_ptr, BLOCK_SIZE) }; + self.device.write(old_index, old_block_buffer); + } + } + } + true + } + + /// 从 LRU cache 里获取一个 block 的引用, 如果没有在 cache 中会加载. + /// 这个函数不应该返回 None + pub(crate) fn get_block<U: Block>(&mut self, index: usize) -> Option<&CachedBlock<U>> { + if !self.cache.contains(&index) { + self.load_block(index); + } + self.cache.get(&index).map(convert::<T, U>) + } + + /// 从 LRU cache 里获取一个 block 的可变引用, 如果没有在 cache 中会加载. + /// 这个函数不应该返回 None + pub(crate) fn get_block_mut<U: Block>(&mut self, index: usize) -> Option<&mut CachedBlock<U>> { + if !self.cache.contains(&index) { + self.load_block(index); + } + self.cache.get_mut(&index).map(|block| { + block.dirty = true; + convert_mut::<T, U>(block) + }) + } + + /// 向 LRU cache 中插入一个全新初始化的 block + /// 这个 block 全 0, 而且是 dirty 的, 即使被挤出去也会触发一次落盘 + pub(crate) fn init_block(&mut self, index: usize) { + let allocated_block = CachedBlock { + block: T::default(), + index, + dirty: true, + }; + if let Some((old_index, old_block)) = self.cache.push(index, allocated_block) { + if old_block.dirty { + let old_block_ptr = &old_block.block as *const T as *mut u8; + let old_block_buffer = + unsafe { std::slice::from_raw_parts(old_block_ptr, BLOCK_SIZE) }; + self.device.write(old_index, old_block_buffer); + } + } + } + + #[allow(unused)] + /// 从 LRU cache 中读取一个 block 的引用, *不会* 影响 LRU cache 的结构, 如果没有在 cache 中不会加载. + pub(crate) fn peek_block<U: Block>(&self, index: usize) -> Option<&CachedBlock<U>> { + self.cache.peek(&index).map(convert::<T, U>) + } + + #[allow(unused)] + /// 从 LRU cache 中读取一个 block 的可变引用, *不会* 影响 LRU cache 的结构, 如果没有在 cache 中不会加载. + pub(crate) fn peek_block_mut<U: Block>(&mut self, index: usize) -> Option<&mut CachedBlock<U>> { + self.cache.peek_mut(&index).map(convert_mut::<T, U>) + } + + pub(crate) fn update_block<U: Block>(&mut self, block: CachedBlock<U>) -> bool { + if self.cache.contains(&block.index) { + let mut data_block = convert::<U, T>(&block).clone(); + data_block.dirty = true; // TODO 需要把显式写回的都标记为 dirty 吗 + self.cache.push(block.index, data_block); + true + } else { + false + } + } + + fn pop(&mut self, entry: &usize) -> Option<CachedBlock<T>> { + self.cache.pop(entry) + } +} + +impl AyaFS { + pub(crate) fn init_block(&mut self, index: usize) { + self.cached_blocks.init_block(index); + } + + pub(crate) fn get_block<T: Block>(&mut self, index: usize) -> Option<&CachedBlock<T>> { + if self.data_bitmap.query(index) { + Some(self.cached_blocks.get_block::<T>(index).unwrap()) + } else { + self.cached_blocks.pop(&index); + None + } + // self.data_bitmap + // .query(index) + // .then(|| self.cached_blocks.get_block::<T>(index).unwrap()) + // 返回 None 当且仅当 data_bitmap 中这个 block 为 invalid + } + + pub(crate) fn get_block_mut<T: Block>(&mut self, index: usize) -> Option<&mut CachedBlock<T>> { + if self.data_bitmap.query(index) { + Some(self.cached_blocks.get_block_mut::<T>(index).unwrap()) + } else { + self.cached_blocks.pop(&index); + None + } + // self.data_bitmap + // .query(index) + // .then(|| self.cached_blocks.get_block_mut::<T>(index).unwrap()) + // 返回 None 当且仅当 data_bitmap 中这个 block 为 invalid + } + + #[allow(unused)] + pub(crate) fn peek_block<T: Block>(&self, index: usize) -> Option<&CachedBlock<T>> { + self.data_bitmap + .query(index) + .then(|| self.cached_blocks.peek_block::<T>(index).unwrap()) + // 返回 None 当且仅当 data_bitmap 中这个 block 为 invalid + } + + #[allow(unused)] + pub(crate) fn peek_block_mut<T: Block>(&mut self, index: usize) -> Option<&mut CachedBlock<T>> { + self.data_bitmap + .query(index) + .then(|| self.cached_blocks.peek_block_mut::<T>(index).unwrap()) + // 返回 None 当且仅当 data_bitmap 中这个 block 为 invalid + } + + pub(crate) fn update_block<T: Block>(&mut self, block: CachedBlock<T>) -> bool { + self.cached_blocks.update_block(block) + } +} diff --git a/ayafs/src/memory/cached_inode.rs b/ayafs/src/memory/cached_inode.rs new file mode 100644 index 0000000..2f26dde --- /dev/null +++ b/ayafs/src/memory/cached_inode.rs @@ -0,0 +1,178 @@ +use crate::disk::block::InodeBlock; +use crate::disk::inode::{Inode, INODE_SIZE}; +use crate::{utils, AyaFS}; +use and_then_some::BoolExt; +use fuser::FileType; +use libc::{c_int, EIO, EISDIR, ENOENT, ENOTDIR, ENOTEMPTY}; + +impl AyaFS { + pub(crate) fn create_file( + &mut self, + permissions: u16, + uid: u32, + gid: u32, + flags: u32, + ) -> Option<(usize, &Inode)> { + self.inode_bitmap.allocate().map(|inode_index| { + self.get_inode_mut(inode_index).map(|inode| { + *inode = Inode::file(permissions, uid, gid, utils::time_now(), flags, 0, 0, 0); + }); + (inode_index, self.get_inode(inode_index).unwrap()) + }) + } + + pub(crate) fn create_symlink( + &mut self, + permissions: u16, + uid: u32, + gid: u32, + flags: u32, + ) -> Option<(usize, &Inode)> { + self.inode_bitmap.allocate().map(|inode_index| { + self.get_inode_mut(inode_index).map(|inode| { + *inode = Inode::symlink(permissions, uid, gid, utils::time_now(), flags, 0, 0, 0); + }); + (inode_index, self.get_inode(inode_index).unwrap()) + }) + } + + /// 根目录的 parent_inode_number 传入 None, 会直接以自己作为 .. 的 inode number + pub(crate) fn create_directory( + &mut self, + permissions: u16, + uid: u32, + gid: u32, + flags: u32, + parent_inode_number: Option<usize>, + ) -> Option<(usize, &Inode)> { + self.inode_bitmap.allocate().map(|inode_index| { + // 创建 Inode + let mut new_inode = + Inode::directory(permissions, uid, gid, utils::time_now(), flags, 0, 0, 0); + self.init_direntry_map(inode_index); + self.add_direntry(inode_index, &mut new_inode, inode_index, ".", 0x2) + .unwrap(); + self.add_direntry( + inode_index, + &mut new_inode, + parent_inode_number.unwrap_or(inode_index), + "..", + 0x2, + ) + .unwrap(); + // 把 inode 放到指定位置 + self.get_inode_mut(inode_index).map(|inode| { + *inode = new_inode; + }); + + (inode_index, self.get_inode(inode_index).unwrap()) + }) + } + + pub(crate) fn remove_file(&mut self, inode_index: usize) -> Result<bool, c_int> { + if self.inode_bitmap.query(inode_index) { + let (block_index, offset) = self.locate_inode(inode_index); + if let Some(cached_block) = self.cached_inodes.get_block::<InodeBlock>(block_index) { + let inode = cached_block.block.inodes[offset / INODE_SIZE].clone(); + match inode.file_type() { + FileType::RegularFile => self.deallocate_all_blocks_for(&inode).unwrap(), + FileType::Symlink => { + if inode.size >= 60 { + self.deallocate_all_blocks_for(&inode).unwrap(); + } + } + FileType::Directory => return Err(EISDIR), + _ => return Err(EIO), + } + } + self.inode_bitmap.deallocate(inode_index); + Ok(true) + } else { + Err(ENOENT) + } + } + + // 要删除的 inode 一定得是空的 + pub(crate) fn remove_dir(&mut self, inode_index: usize) -> Result<bool, c_int> { + if self.inode_bitmap.query(inode_index) { + let (block_index, offset) = self.locate_inode(inode_index); + if let Some(cached_block) = self.cached_inodes.get_block::<InodeBlock>(block_index) { + let inode = &cached_block.block.inodes[offset / INODE_SIZE].clone(); + if !inode.is_dir() { + // 不是 dir -> ENOTDIR + return Err(ENOTDIR); + } + if inode.size > 2 { + // 有 . 和 .. 以外的 entry -> ENOTEMPTY + return Err(ENOTEMPTY); + } + // 销毁 inode 里的所有 block + self.deallocate_all_blocks_for(inode).unwrap(); + } + // 销毁 inode + self.inode_bitmap.deallocate(inode_index); + Ok(true) + } else { + Err(ENOENT) + } + } + + pub(crate) fn update_inode(&mut self, inode_index: usize, inode: Inode) -> bool { + if self.inode_bitmap.query(inode_index) { + let (block_index, offset) = self.locate_inode(inode_index); + if let Some(cached_block) = self.cached_inodes.get_block_mut::<InodeBlock>(block_index) + { + cached_block.block.inodes[offset / INODE_SIZE] = inode; + } + true + } else { + false + } + } + + pub(crate) fn get_inode(&mut self, inode_index: usize) -> Option<&Inode> { + self.inode_bitmap.query(inode_index).and_then(|| { + let (block_index, offset) = self.locate_inode(inode_index); + // debug!("get_inode(inode_index: {}) -> block_index: {}, offset: {}", inode_index, block_index, offset); + self.cached_inodes + .get_block::<InodeBlock>(block_index) + .map(|cached_block| &cached_block.block.inodes[offset / INODE_SIZE]) + }) + } + + pub(crate) fn get_inode_mut(&mut self, inode_index: usize) -> Option<&mut Inode> { + self.inode_bitmap.query(inode_index).and_then(|| { + let (block_index, offset) = self.locate_inode(inode_index); + // debug!("get_inode_mut(inode_index: {}) -> block_index: {}, offset: {}", inode_index, block_index, offset); + self.cached_inodes + .get_block_mut::<InodeBlock>(block_index) + .map(|cached_block| { + cached_block.dirty = true; // 保守一些, 只要返回了 &mut Inode 这个页一定标记为脏 + &mut cached_block.block.inodes[offset / INODE_SIZE] + }) + }) + } + + #[allow(unused)] + pub(crate) fn peek_inode(&self, inode_index: usize) -> Option<&Inode> { + self.inode_bitmap.query(inode_index).and_then(|| { + let (block_index, offset) = self.locate_inode(inode_index); + self.cached_inodes + .peek_block::<InodeBlock>(block_index) + .map(|cached_block| &cached_block.block.inodes[offset / INODE_SIZE]) + }) + } + + #[allow(unused)] + pub(crate) fn peek_inode_mut(&mut self, inode_index: usize) -> Option<&mut Inode> { + self.inode_bitmap.query(inode_index).and_then(|| { + let (block_index, offset) = self.locate_inode(inode_index); + self.cached_inodes + .peek_block_mut::<InodeBlock>(block_index) + .map(|cached_block| { + cached_block.dirty = true; // 保守一些, 只要返回了 &mut Inode 这个页一定标记为脏 + &mut cached_block.block.inodes[offset / INODE_SIZE] + }) + }) + } +} diff --git a/ayafs/src/memory/dir_entry.rs b/ayafs/src/memory/dir_entry.rs new file mode 100644 index 0000000..c013e1e --- /dev/null +++ b/ayafs/src/memory/dir_entry.rs @@ -0,0 +1,305 @@ +use crate::disk::block::{DirectoryBlock, DirectoryEntry}; +use crate::disk::inode::Inode; +use crate::AyaFS; +use indexmap::IndexMap; +use libc::{c_int, ENOENT, ENOSPC}; +use log::debug; +use std::ffi::{OsStr, OsString}; +use std::os::unix::ffi::OsStrExt; +use indexmap::map::Entry::Occupied; + +impl AyaFS { + pub(crate) fn init_direntry_map(&mut self, index: usize) { + let direntry_map: IndexMap<OsString, DirectoryEntry> = IndexMap::new(); + if let Some((old_inode_index, old_dir_entry_map)) = + self.dir_entry_map.push(index, direntry_map) + { + if let Some(old_inode) = self.get_inode(old_inode_index) { + let mut old_inode = old_inode.clone(); + self.write_back_direntry(old_inode_index, &mut old_inode, old_dir_entry_map) + .unwrap(); + self.update_inode(old_inode_index, old_inode); + } + } + } + + pub(crate) fn load_direntry_map(&mut self, index: usize, inode: &Inode) -> Result<(), c_int> { + if self.dir_entry_map.contains(&index) { + debug!("load_direntry_map(ino: {}) already in cache", index); + return Ok(()); + } + + debug!("load_direntry_map(ino: {}) loading", index); + let mut dir_entry_map: IndexMap<OsString, DirectoryEntry> = IndexMap::new(); + let mut entry_index: usize = 0; + loop { + let block_index_within_inode = entry_index / 15; + let entry_index_within_block = entry_index % 15; + + match self.access_block::<DirectoryBlock>(inode, block_index_within_inode) { + Some(directory_block) => { + if directory_block.block.query(entry_index_within_block) { + let dir_entry = &directory_block.block.entries[entry_index_within_block]; + let name = dir_entry.name(); + dir_entry_map.insert(name, dir_entry.clone()); + } else { + break; + } + } + None => break, + } + entry_index += 1; + } + + if let Some((old_inode_index, old_dir_entry_map)) = + self.dir_entry_map.push(index, dir_entry_map) + { + if let Some(old_inode) = self.get_inode(old_inode_index) { + let mut old_inode = old_inode.clone(); + self.write_back_direntry(old_inode_index, &mut old_inode, old_dir_entry_map)?; + self.update_inode(old_inode_index, old_inode); + } + } + + Ok(()) + } + + pub(crate) fn write_back_direntry( + &mut self, + _parent_index: usize, + parent_inode: &mut Inode, + dir_entry_map: IndexMap<OsString, DirectoryEntry>, + ) -> Result<(), c_int> { + for (entry_index, (_, dir_entry)) in dir_entry_map.into_iter().enumerate() { + let block_index_within_inode = entry_index / 15; + let entry_index_within_block = entry_index % 15; + // 不够就新分配 + if self + .get_block_index(parent_inode, block_index_within_inode) + .is_none() + { + match self.allocate_block_for(parent_inode) { + Some((_, block_index_within)) => { + assert_eq!(block_index_within, block_index_within_inode); + } + None => { + return Err(ENOSPC); + } + } + } + match self.access_block_mut::<DirectoryBlock>(parent_inode, block_index_within_inode) { + Some(directory_block) => { + directory_block.block.allocate(entry_index_within_block); + directory_block.block.entries[entry_index_within_block] = dir_entry; + } + None => { + return Err(ENOENT); + } + } + } + Ok(()) + } + + pub(crate) fn exchange_direntry<T: AsRef<OsStr>>( + &mut self, + parent_index: usize, + parent_inode: &mut Inode, + name: T, + new_parent_index: usize, + new_parent_inode: &mut Inode, + new_name: T, + ) -> Result<(), c_int> { + self.load_direntry_map(parent_index, parent_inode)?; + self.load_direntry_map(new_parent_index, new_parent_inode)?; + + let dir_entry = self.dir_entry_map + .get(&parent_index) + .ok_or(ENOENT)? + .get(name.as_ref()) + .cloned() + .ok_or(ENOENT)?; + let new_dir_entry = self.dir_entry_map + .get(&new_parent_index) + .ok_or(ENOENT)? + .get(new_name.as_ref()) + .cloned() + .ok_or(ENOENT)?; + + let name: &OsStr = name.as_ref(); + let new_name: &OsStr = new_name.as_ref(); + + self.dir_entry_map + .get_mut(&parent_index) + .map(|dir_entry_map| { + if let Occupied(mut entry) = dir_entry_map.entry(name.to_os_string()) { + *entry.get_mut() = new_dir_entry.clone(); + } + }) + .ok_or(ENOENT)?; + self.dir_entry_map + .get_mut(&new_parent_index) + .map(|new_dir_entry_map| { + if let Occupied(mut entry) = new_dir_entry_map.entry(new_name.to_os_string()) { + *entry.get_mut() = dir_entry.clone(); + } + }) + .ok_or(ENOENT)?; + + Ok(()) + } + + /// 删除第 entry_index 个 dir entry + pub(crate) fn remove_direntry<T: AsRef<OsStr>>( + &mut self, + parent_index: usize, + parent_inode: &mut Inode, + name: T, + _entry_index: u32, + ) -> Result<(), c_int> { + self.load_direntry_map(parent_index, parent_inode)?; + if let Some(dir_entry_map) = self.dir_entry_map.get_mut(&parent_index) { + debug!(" remove_direntry(ino: {}) using hashmap", parent_index); + if dir_entry_map.shift_remove(name.as_ref()).is_some() { + Ok(()) + } else { + Err(ENOENT) + } + } else { + Err(ENOENT) + } + } + + pub(crate) fn add_direntry_2<T: AsRef<OsStr>>( + &mut self, + parent_index: usize, + parent_inode: &mut Inode, + child_inode_name: T, + dir_entry: DirectoryEntry, + ) -> Result<u32, c_int> { + let child_inode_name = child_inode_name.as_ref(); + self.load_direntry_map(parent_index, parent_inode)?; + if let Some(dir_entry_map) = self.dir_entry_map.get_mut(&parent_index) { + let (entry_index, _) = + dir_entry_map.insert_full(child_inode_name.to_os_string(), dir_entry); + debug!( + " add_direntry(ino: {}) using hashmap, entry {}", + parent_index, entry_index + ); + parent_inode.size += 1; + Ok(entry_index as u32) + } else { + Err(ENOENT) + } + } + + pub(crate) fn add_direntry<T: AsRef<OsStr>>( + &mut self, + parent_index: usize, + parent_inode: &mut Inode, + child_inode_index: usize, + child_inode_name: T, + file_type: u8, + ) -> Result<u32, c_int> { + let child_inode_name = child_inode_name.as_ref(); + self.load_direntry_map(parent_index, parent_inode)?; + if let Some(dir_entry_map) = self.dir_entry_map.get_mut(&parent_index) { + let name_len = child_inode_name.len() as u8; + let mut name = [0u8; 256]; + (&mut name[0..child_inode_name.len()]).copy_from_slice(child_inode_name.as_bytes()); + + let dir_entry = DirectoryEntry { + inode: child_inode_index as u32, + record_len: 264, + name_len, + file_type, + name, + }; + + let (entry_index, _) = + dir_entry_map.insert_full(child_inode_name.to_os_string(), dir_entry); + debug!( + " add_direntry(ino: {}) using hashmap, entry {}", + parent_index, entry_index + ); + parent_inode.size += 1; + Ok(entry_index as u32) + } else { + Err(ENOENT) + } + } + + pub(crate) fn get_direntry_by_name<T: AsRef<OsStr>>( + &mut self, + parent_index: usize, + parent_inode: &Inode, + name: T, + ) -> Result<DirectoryEntry, c_int> { + self.load_direntry_map(parent_index, parent_inode)?; + if let Some(dir_entry_map) = self.dir_entry_map.get(&parent_index) { + debug!( + " get_direntry(ino: {}, name: {:?}) using hashmap", + parent_index, name.as_ref() + ); + dir_entry_map + .get(name.as_ref()) + .cloned() + .ok_or(ENOENT) + } else { + Err(ENOENT) + } + } + + pub(crate) fn get_direntry( + &mut self, + parent_index: usize, + parent_inode: &Inode, + entry_index: u32, + ) -> Result<DirectoryEntry, c_int> { + self.load_direntry_map(parent_index, parent_inode)?; + if let Some(dir_entry_map) = self.dir_entry_map.get(&parent_index) { + debug!( + " get_direntry(ino: {}, entry_index: {}) using hashmap", + parent_index, entry_index + ); + dir_entry_map + .iter() + .skip(entry_index as usize) + .next() + .map(|entry| entry.1.clone()) + .ok_or(ENOENT) + } else { + Err(ENOENT) + } + } + + /// 返回 inode_index, inode 在 parent 里的 index, inode 本身 + pub fn lookup_name( + &mut self, + parent_index: usize, + parent_inode: &Inode, + name: &OsStr, + ) -> Result<(u32, u32, Inode), c_int> { + self.load_direntry_map(parent_index, parent_inode)?; + if let Some(dir_entry_map) = self.dir_entry_map.get(&parent_index) { + if let Some((entry_index, _, dir_entry)) = dir_entry_map.get_full(name) { + let inode_index = dir_entry.inode; + let inode = self.get_inode(inode_index as usize).unwrap().clone(); + Ok((inode_index, entry_index as u32, inode)) + } else { + Err(ENOENT) + } + } else { + let mut entry_index = 0; + while entry_index < parent_inode.size { + if let Ok(entry) = self.get_direntry(parent_index, parent_inode, entry_index) { + if entry.name() == name { + let inode = self.get_inode(entry.inode as usize).unwrap().clone(); + return Ok((entry.inode, entry_index, inode)); + } + } + entry_index += 1; + } + Err(ENOENT) + } + } +} diff --git a/ayafs/src/memory/file_handle.rs b/ayafs/src/memory/file_handle.rs new file mode 100644 index 0000000..c821619 --- /dev/null +++ b/ayafs/src/memory/file_handle.rs @@ -0,0 +1,15 @@ +use crate::AyaFS; +use std::sync::atomic::Ordering; + +impl AyaFS { + pub(crate) fn allocate_file_descriptor( + &mut self, + inode_index: usize, + read: bool, + write: bool, + ) -> u64 { + let fd = self.next_file_handle.fetch_add(1, Ordering::SeqCst); + self.file_handle_map.insert(fd, (inode_index, read, write)); + fd + } +} diff --git a/ayafs/src/memory/mod.rs b/ayafs/src/memory/mod.rs new file mode 100644 index 0000000..d1f1ab8 --- /dev/null +++ b/ayafs/src/memory/mod.rs @@ -0,0 +1,6 @@ +/// In-memory data structures and logic. +/// This is where the crucial block and inode methods presented to upper calls implemented. +pub mod cached_block; +pub mod cached_inode; +mod dir_entry; +mod file_handle; diff --git a/ayafs/src/tests/bitmap.rs b/ayafs/src/tests/bitmap.rs new file mode 100644 index 0000000..1a43f09 --- /dev/null +++ b/ayafs/src/tests/bitmap.rs @@ -0,0 +1,38 @@ +use crate::tests::common; +use indexmap::IndexMap; + +#[test] +fn test_allocate() { + let mut fs = common::setup(); + for _ in 0..10 { + fs.data_bitmap.allocate().unwrap(); + } + assert!(fs.data_bitmap.deallocate(5)); + assert_eq!(fs.data_bitmap.allocate().unwrap(), 5); + assert_eq!(fs.data_bitmap.allocate().unwrap(), 11); +} + +#[test] +fn test_query() { + let mut fs = common::setup(); + for _ in 0..10 { + fs.data_bitmap.allocate().unwrap(); + } + assert_eq!(fs.data_bitmap.query(0), false); + assert_eq!(fs.data_bitmap.query(5), true); + assert_eq!(fs.data_bitmap.query(11), false); +} + +#[test] +fn test_index_map() { + let mut map: IndexMap<i32, i32> = IndexMap::new(); + map.insert(1, 2); + map.insert(2, 3); + map.insert(3, 4); + map.insert(4, 5); + map.remove(&3); + + for (entry_index, (key, value)) in map.iter().enumerate() { + println!("index {}, key {}, value {}", entry_index, key, value); + } +} diff --git a/ayafs/src/tests/block_cache.rs b/ayafs/src/tests/block_cache.rs new file mode 100644 index 0000000..52117b9 --- /dev/null +++ b/ayafs/src/tests/block_cache.rs @@ -0,0 +1,245 @@ +use crate::disk::block::{DataBlock, DoubleIndirectBlock, IndirectBlock}; +use crate::disk::inode::InodeMode; +use crate::tests::common; + +#[test] +fn test_basic_lru() { + let mut fs = common::setup(); + + let v: Vec<usize> = (1..=256) + .map(|_| { + let index = fs.data_bitmap.allocate().unwrap(); + fs.get_block::<DataBlock>(index).unwrap(); + index + }) + .collect(); + assert!(fs.peek_block::<DataBlock>(v[0]).is_some()); + + for i in 0..256 { + let index = fs.data_bitmap.allocate().unwrap(); + fs.get_block::<DataBlock>(index).unwrap(); + assert!(fs.peek_block::<DataBlock>(v[i]).is_none()); + } +} + +#[test] +fn test_inode_allocation() { + let mut fs = common::setup(); + + let (inode_index, inode) = fs.create_directory(0o755, 0, 0, 0, None).unwrap(); + let mut inode = inode.clone(); + + const DIRECT_NUMBER: u32 = 15; + const INDIRECT_NUMBER: u32 = 1024; + // const DOUBLE_INDIRECT_NUMBER: u32 = 1024 * 1024; + + for i in 0..DIRECT_NUMBER { + fs.allocate_block_for(&mut inode).unwrap(); + assert!(fs.data_bitmap.query(inode.direct[i as usize] as usize)) + } + + for _i in 0..INDIRECT_NUMBER { + fs.allocate_block_for(&mut inode).unwrap(); + } + + println!("single indirect is {}", inode.single_indirect); + println!("double indirect is {}", inode.double_indirect); + println!("triple indirect is {}", inode.triple_indirect); + + let indirect_block = fs + .peek_block::<IndirectBlock>(inode.single_indirect as usize) + .unwrap(); + for entry in indirect_block.block.entries { + assert_ne!(entry, 0); + assert!(fs.data_bitmap.query(entry as usize)); + } + + assert_eq!(fs.data_bitmap.query(inode.double_indirect as usize), false); + assert_eq!(fs.data_bitmap.query(inode.triple_indirect as usize), false); + + for _i in 0..INDIRECT_NUMBER { + fs.allocate_block_for(&mut inode).unwrap(); + } + + let double_indirect = inode.double_indirect; + println!( + "double indirect is {} after allocation", + inode.double_indirect + ); + + fs.update_inode(inode_index, inode); + + assert!(fs.data_bitmap.query(double_indirect as usize)); +} + +#[test] +fn test_inode_deallocation() { + let mut fs = common::setup(); + + let (inode_index, inode) = fs.create_directory(0o755, 0, 0, 0, None).unwrap(); + let mut inode = inode.clone(); + + const DIRECT_NUMBER: u32 = 15; + const INDIRECT_NUMBER: u32 = 1024; + // const DOUBLE_INDIRECT_NUMBER: u32 = 1024 * 1024; + + for i in 0..DIRECT_NUMBER { + println!("Allocated {:?}", fs.allocate_block_for(&mut inode).unwrap()); + assert!(fs.data_bitmap.query(inode.direct[i as usize] as usize)) + } + + for _i in 0..2 * INDIRECT_NUMBER { + println!("Allocated {:?}", fs.allocate_block_for(&mut inode).unwrap()); + } + + println!("single indirect is {}", inode.single_indirect); + println!("double indirect is {}", inode.double_indirect); + println!("triple indirect is {}", inode.triple_indirect); + + assert!(fs.data_bitmap.query(inode.double_indirect as usize)); + + for i in 0..INDIRECT_NUMBER + 5 { + println!( + "Deallocated {}", + fs.deallocate_block_for(&mut inode).unwrap() + ); + } + + println!("single indirect is {}", inode.single_indirect); + println!("double indirect is {}", inode.double_indirect); + println!("triple indirect is {}", inode.triple_indirect); + + assert_eq!(fs.data_bitmap.query(inode.double_indirect as usize), false); + + fs.update_inode(inode_index, inode); +} + +#[test] +fn test_multiple_inode_allocation() { + let mut fs = common::setup(); + + let (inode_index_1, inode_1) = fs.create_directory(0o755, 0, 0, 0, None).unwrap(); + let mut inode_1 = inode_1.clone(); + + let (inode_index_2, inode_2) = fs.create_file(0o755, 0, 0, 0).unwrap(); + let mut inode_2 = inode_2.clone(); + // let mut inode_1 = fs.get_inode(inode_index_1).unwrap().clone(); + // let mut inode_2 = fs.get_inode(inode_index_2).unwrap().clone(); + + const DIRECT_NUMBER: u32 = 15; + const INDIRECT_NUMBER: u32 = 1024; + + for i in 0..DIRECT_NUMBER + INDIRECT_NUMBER { + println!( + "Allocated {:?} in inode {}", + fs.allocate_block_for(&mut inode_1).unwrap(), + inode_index_1 + ); + println!( + "Allocated {:?} in inode {}", + fs.allocate_block_for(&mut inode_2).unwrap(), + inode_index_2 + ); + } + + let (inode_index_3, inode_3) = fs.create_directory(0o755, 0, 0, 0, None).unwrap(); + let mut inode_3 = inode_3.clone(); + // let mut inode_3 = fs.get_inode(inode_index_3).unwrap().clone(); + + for _i in 0..INDIRECT_NUMBER { + println!( + "Deallocated {} in inode {}", + fs.deallocate_block_for(&mut inode_1).unwrap(), + inode_index_1 + ); + println!( + "Allocated {:?} in inode {}", + fs.allocate_block_for(&mut inode_3).unwrap(), + inode_index_3 + ); + } + + for _i in 0..DIRECT_NUMBER { + println!( + "Deallocated {} in inode {}", + fs.deallocate_block_for(&mut inode_1).unwrap(), + inode_index_1 + ); + } + + assert!(fs.deallocate_block_for(&mut inode_1).is_none()); + + println!( + "single indirect is {} for {}", + inode_1.single_indirect, inode_index_1 + ); + println!( + "double indirect is {} for {}", + inode_1.double_indirect, inode_index_1 + ); + println!( + "single indirect is {} for {}", + inode_2.single_indirect, inode_index_2 + ); + println!( + "double indirect is {} for {}", + inode_2.double_indirect, inode_index_2 + ); + println!( + "single indirect is {} for {}", + inode_3.single_indirect, inode_index_3 + ); + println!( + "double indirect is {} for {}", + inode_3.double_indirect, inode_index_3 + ); + + assert_eq!( + fs.data_bitmap.query(inode_1.single_indirect as usize), + false + ); + assert!(fs.data_bitmap.query(inode_2.single_indirect as usize)); + assert_eq!( + fs.data_bitmap.query(inode_2.double_indirect as usize), + false + ); + assert!(fs.data_bitmap.query(inode_3.single_indirect as usize)); + assert_eq!( + fs.data_bitmap.query(inode_3.double_indirect as usize), + false + ); + + fs.allocate_block_for(&mut inode_2).unwrap(); + println!("-----------------"); + println!( + "double indirect is {} for {}", + inode_2.double_indirect, inode_index_2 + ); + + assert!(fs.data_bitmap.query(inode_2.double_indirect as usize)); + + for _i in 0..DIRECT_NUMBER { + fs.allocate_block_for(&mut inode_3).unwrap(); + } + println!("-----------------"); + println!( + "double indirect is {} for {}", + inode_3.double_indirect, inode_index_3 + ); + assert_eq!( + fs.data_bitmap.query(inode_3.double_indirect as usize), + false + ); + + fs.allocate_block_for(&mut inode_3).unwrap(); + println!("-----------------"); + println!( + "double indirect is {} for {}", + inode_3.double_indirect, inode_index_3 + ); + assert!(fs.data_bitmap.query(inode_3.double_indirect as usize)); + + fs.update_inode(inode_index_1, inode_1); + fs.update_inode(inode_index_2, inode_2); + fs.update_inode(inode_index_3, inode_3); +} diff --git a/ayafs/src/tests/common/mod.rs b/ayafs/src/tests/common/mod.rs new file mode 100644 index 0000000..3abfcb4 --- /dev/null +++ b/ayafs/src/tests/common/mod.rs @@ -0,0 +1,9 @@ +use crate::block_device::memory_disk::MemoryDisk; +use crate::AyaFS; +use std::sync::Arc; + +#[allow(unused)] +pub(crate) fn setup() -> AyaFS { + let mem_disk = Arc::new(MemoryDisk::new(1059715)); + AyaFS::new(mem_disk, 1059715) +} diff --git a/ayafs/src/tests/mod.rs b/ayafs/src/tests/mod.rs new file mode 100644 index 0000000..df442c1 --- /dev/null +++ b/ayafs/src/tests/mod.rs @@ -0,0 +1,6 @@ +#[cfg(test)] +mod bitmap; +mod common; + +#[cfg(test)] +mod block_cache; diff --git a/ayafs/src/utils/constants.rs b/ayafs/src/utils/constants.rs new file mode 100644 index 0000000..8b13789 --- /dev/null +++ b/ayafs/src/utils/constants.rs @@ -0,0 +1 @@ + diff --git a/ayafs/src/utils/mod.rs b/ayafs/src/utils/mod.rs new file mode 100644 index 0000000..468ebdb --- /dev/null +++ b/ayafs/src/utils/mod.rs @@ -0,0 +1,92 @@ +mod constants; +pub mod permissions; + +use crate::block_device::BLOCK_SIZE; +use crate::disk::inode::{Inode, INODE_SIZE}; +use crate::{AyaFS, INODE_PER_BLOCK}; +use fuser::{FileAttr, FileType}; +use std::time::{Duration, SystemTime, UNIX_EPOCH}; + +pub(crate) fn time_now() -> u32 { + SystemTime::now() + .duration_since(UNIX_EPOCH) + .expect("How can current time be earlier than UNIX_EPOCH?") + .as_secs() as u32 +} + +pub(crate) fn from_systime(system_time: SystemTime) -> u32 { + system_time + .duration_since(UNIX_EPOCH) + .expect("How can current time be earlier than UNIX_EPOCH?") + .as_secs() as u32 +} + +pub(crate) fn to_systime(time: u32) -> SystemTime { + UNIX_EPOCH + Duration::from_secs(time as u64) +} + +// File type code, one of: +// 0x0 Unknown. +// 0x1 Regular file. +// 0x2 Directory. +// 0x3 Character device file. +// 0x4 Block device file. +// 0x5 FIFO. +// 0x6 Socket. +// 0x7 Symbolic link. + +pub(crate) fn from_filetype(file_type: FileType) -> u8 { + match file_type { + FileType::NamedPipe => 0x5, + FileType::CharDevice => 0x3, + FileType::BlockDevice => 0x4, + FileType::Directory => 0x2, + FileType::RegularFile => 0x1, + FileType::Symlink => 0x7, + FileType::Socket => 0x6, + } +} + +pub(crate) fn to_filetype(file_type: u8) -> Option<FileType> { + match file_type { + 0x0 => None, + 0x1 => Some(FileType::RegularFile), + 0x2 => Some(FileType::Directory), + 0x3 => Some(FileType::CharDevice), + 0x4 => Some(FileType::BlockDevice), + 0x5 => Some(FileType::NamedPipe), + 0x6 => Some(FileType::Socket), + 0x7 => Some(FileType::Symlink), + _ => panic!("bad filetype"), + } +} + +pub(crate) fn to_fileattr(inode_index: usize, inode: &Inode) -> FileAttr { + FileAttr { + ino: inode_index as u64, + size: inode.size as u64, + blocks: inode.n_blocks as u64, + atime: to_systime(inode.atime), + mtime: to_systime(inode.mtime), + ctime: to_systime(inode.ctime), + crtime: to_systime(inode.crtime), + kind: inode.mode.into(), + perm: inode.mode.perm(), + nlink: inode.n_links as u32, + uid: inode.uid, + gid: inode.gid, + rdev: 0, + blksize: BLOCK_SIZE as u32, + flags: inode.flags, + } +} + +impl AyaFS { + /// 输入 inode 编号, 返回它对应的 block number 和 block 内 offset + pub(crate) fn locate_inode(&self, inode_index: usize) -> (usize, usize) { + let block_number = + inode_index / INODE_PER_BLOCK + 1 + self.inode_bitmap.length + self.data_bitmap.length; + let block_offset = inode_index % INODE_PER_BLOCK * INODE_SIZE; + (block_number, block_offset) + } +} diff --git a/ayafs/src/utils/permissions.rs b/ayafs/src/utils/permissions.rs new file mode 100644 index 0000000..6773511 --- /dev/null +++ b/ayafs/src/utils/permissions.rs @@ -0,0 +1,62 @@ +use crate::disk::inode::InodeMode; +use libc::{F_OK, S_ISGID, S_ISUID, S_IXGRP, X_OK}; +use std::fs::File; +use std::io::BufRead; + +pub(crate) fn get_groups(pid: u32) -> Vec<u32> { + let file = File::open(format!("/proc/{pid}/task/{pid}/status")) + .expect(format!("pid {pid} incorrect!").as_str()); + for line in std::io::BufReader::new(file).lines() { + let line = line.unwrap(); + if line.starts_with("Groups:") { + return line["Groups: ".len()..] + .split(' ') + .filter(|x| !x.trim().is_empty()) + .map(|x| x.parse::<u32>().unwrap()) + .collect(); + } + } + + Vec::new() +} + +pub(crate) fn clear_suid_sgid(mut mode: InodeMode) -> InodeMode { + mode.0 &= !S_ISUID as u16; + if mode.0 & S_IXGRP as u16 != 0 { + mode.0 &= !S_ISGID as u16; + } + mode +} + +pub(crate) fn check_access( + incoming_uid: u32, + incoming_gid: u32, + uid: u32, + gid: u32, + mode: InodeMode, + mut mask: i32, +) -> bool { + if mask == F_OK { + return true; + } + + let perm = i32::from(mode.0); + // root + if incoming_uid == 0 { + // 读写任何东西都是可以的, 执行只有 IXOTH/IXGRP/IXUSR 之一设置才可以 + mask &= X_OK; + mask -= mask & (perm >> 6); + mask -= mask & (perm >> 3); + mask -= mask & perm; + return mask == 0; + } + + if incoming_uid == uid { + mask -= mask & (perm >> 6); + } else if incoming_gid == gid { + mask -= mask & (perm >> 3); + } else { + mask -= mask & perm; + } + mask == 0 +} |