diff options
| -rw-r--r-- | src/disk/allocation.rs | 159 | ||||
| -rw-r--r-- | src/disk/block.rs | 50 | ||||
| -rw-r--r-- | src/filesystem/trait_impl.rs | 2 | ||||
| -rw-r--r-- | src/memory/cached_block.rs | 22 | ||||
| -rw-r--r-- | src/memory/cached_inode.rs | 2 | ||||
| -rw-r--r-- | src/memory/dir_entry.rs | 103 | ||||
| -rw-r--r-- | src/memory/inode_iter.rs | 233 | ||||
| -rw-r--r-- | src/memory/mod.rs | 2 |
8 files changed, 301 insertions, 272 deletions
diff --git a/src/disk/allocation.rs b/src/disk/allocation.rs index bde2014..57cca0e 100644 --- a/src/disk/allocation.rs +++ b/src/disk/allocation.rs @@ -1,20 +1,20 @@ -use crate::disk::block::{DataBlock, DoubleIndirectBlock, IndirectBlock, TripleIndirectBlock}; -use crate::disk::inode::Inode; -use crate::memory::cached_block::convert; -use crate::AyaFS; +use crate::disk::block::{Block, DataBlock, DoubleIndirectBlock, IndirectBlock, TripleIndirectBlock}; +use crate::disk::inode::{DIRECT_NUMBER, Inode}; +use crate::memory::cached_block::{CachedBlock, convert}; +use crate::{AyaFS, INODE_PER_BLOCK}; impl AyaFS { - /// 为 Inode 分配新 block, 返回 block 的编号 - pub(crate) fn allocate_block_for(&mut self, inode: &mut Inode) -> Option<u32> { + /// 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 in inode.direct.iter_mut() { + 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; // 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); + return Some((block_index, index_within_direct)); } } @@ -27,10 +27,11 @@ impl AyaFS { // println!("allocating {} for indirect", inode.single_indirect); } // 在 indirect block 里尝试分配 - if let Some(block_index) = self.allocate_in_indirect(inode.single_indirect) { + 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; - return Some(block_index); + 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 @@ -42,10 +43,11 @@ impl AyaFS { // println!("allocating {} for double indirect", inode.double_indirect); } // 在 double indirect block 里尝试分配 - if let Some(block_index) = self.alloc_in_double_indirect(inode.double_indirect) { + 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; - return Some(block_index); + let index_within_block = DIRECT_NUMBER + INODE_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 @@ -57,15 +59,16 @@ impl AyaFS { // println!("allocating {} for triple indirect", inode.triple_indirect); } // 在 double indirect block 里尝试分配 - if let Some(block_index) = self.alloc_in_triple_indirect(inode.triple_indirect) { + 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; - return Some(block_index); + let index_within_block = DIRECT_NUMBER + INODE_PER_BLOCK + INODE_PER_BLOCK * INODE_PER_BLOCK + index_within_triple; + return Some((block_index, index_within_block)); } None } - fn allocate_in_indirect(&mut self, indirect_entry: u32) -> Option<u32> { + 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)); @@ -76,20 +79,20 @@ impl AyaFS { { // println!("found indirect block with number {}", indirect_entry); let mut indirect_block = block.clone(); - for entry in indirect_block.block.entries.iter_mut() { + 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; *entry = block_index; self.update_block(indirect_block); - return Some(block_index); + return Some((block_index, index_within_indirect)); } } } None } - fn alloc_in_double_indirect(&mut self, double_indirect_entry: u32) -> Option<u32> { + 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 @@ -97,24 +100,27 @@ impl AyaFS { .map(convert::<DataBlock, DoubleIndirectBlock>) { let mut double_indirect_block = block.clone(); - for indirect_entry in double_indirect_block.block.indirect.iter_mut() { + 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; *indirect_entry = self.data_bitmap.allocate().expect("No free space") as u32; } - if let Some(block_index) = self.allocate_in_indirect(*indirect_entry) { - if double_indirect_block.dirty { + if let Some((block_index, index_within_indirect)) = self.allocate_in_indirect(*indirect_entry) { + if double_indirect_modified { self.update_block(double_indirect_block); } - return Some(block_index); + let index_within_double = index_within_double_indirect * INODE_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> { + 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 @@ -122,17 +128,20 @@ impl AyaFS { .map(convert::<DataBlock, TripleIndirectBlock>) { let mut triple_indirect_block = block.clone(); - for double_indirect_entry in triple_indirect_block.block.double_indirect.iter_mut() { + 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; *double_indirect_entry = self.data_bitmap.allocate().expect("No free space") as u32; } - if let Some(block_index) = self.alloc_in_double_indirect(*double_indirect_entry) { - if triple_indirect_block.dirty { + 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); } - return Some(block_index); + let index_within_triple = index_within_triple_indirect * INODE_PER_BLOCK * INODE_PER_BLOCK + index_within_double_indirect; + return Some((block_index, index_within_triple)); } } } @@ -283,3 +292,99 @@ impl AyaFS { None } } + +impl AyaFS { + fn get_block_index(&mut self, inode: &Inode, mut block_index_within_inode: usize) -> Option<usize> { + // direct block + if block_index_within_inode < DIRECT_NUMBER { + let block_index = inode.direct[block_index_within_inode] as usize; + return Some(block_index); + } else { + block_index_within_inode -= DIRECT_NUMBER; + } + + // indirect block + let indirect_number = INODE_PER_BLOCK; + if block_index_within_inode < indirect_number { + return if let Some(indirect_block) = + self.get_block::<IndirectBlock>(inode.single_indirect as usize) + { + let block_index = indirect_block.block.entries[block_index_within_inode] as usize; + Some(block_index) + } else { + None + }; + } else { + block_index_within_inode -= indirect_number; + } + + // double indirect block + let double_indirect_number = INODE_PER_BLOCK * INODE_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) + { + // 取出 double indirect block + let indirect_block_index = double_indirect_block.block.indirect + [block_index_within_inode / INODE_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 % INODE_PER_BLOCK] + as usize; + // 拿到 DirectoryBlock 的 index + return Some(block_index) + } + } + 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 / (INODE_PER_BLOCK * INODE_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 % (INODE_PER_BLOCK * INODE_PER_BLOCK) + / INODE_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 % INODE_PER_BLOCK] + as usize; + // DirectoryBlock 的 index + return Some(block_index) + } + } + } + + 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| { + self.get_block_mut::<T>(block_index).unwrap() // 可以 unwrap 吧这里 ?? + }) + } +}
\ No newline at end of file diff --git a/src/disk/block.rs b/src/disk/block.rs index 0058b3e..be3d85a 100644 --- a/src/disk/block.rs +++ b/src/disk/block.rs @@ -49,7 +49,7 @@ impl Default for InodeBlock { impl Block for InodeBlock {} -const FULL_MAP: u32 = 0b111_111_111_111_111; +const FULL_MAP: u16 = 0b111_111_111_111_111; #[repr(C)] #[derive(Clone)] @@ -84,7 +84,8 @@ impl Default for DirectoryEntry { #[derive(Clone)] pub struct DirectoryBlock { pub entries: [DirectoryEntry; 15], - reserved: [u8; 136], + pub occupancy: [u8; 2], + reserved: [u8; 134], } impl Default for DirectoryBlock { @@ -107,7 +108,50 @@ impl Default for DirectoryBlock { DirectoryEntry::default(), DirectoryEntry::default(), ], - reserved: [0xFF; 136], + occupancy: [0x80, 0x00], // 0b1000_0000 + reserved: [0xFF; 134], + } + } +} + +impl DirectoryBlock { + 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) -> 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); } } } diff --git a/src/filesystem/trait_impl.rs b/src/filesystem/trait_impl.rs index c533c41..73ae878 100644 --- a/src/filesystem/trait_impl.rs +++ b/src/filesystem/trait_impl.rs @@ -46,7 +46,7 @@ impl Filesystem for AyaFS { ) { let parent_inode = parent_inode.clone(); match self.lookup_name(&parent_inode, name) { - Ok((inode_index, inode)) => { + Ok((inode_index, _, inode)) => { let attr = to_fileattr(inode_index as usize, &inode); reply.entry(&TTL, &attr, 0); }, diff --git a/src/memory/cached_block.rs b/src/memory/cached_block.rs index 77cdf61..783e987 100644 --- a/src/memory/cached_block.rs +++ b/src/memory/cached_block.rs @@ -70,6 +70,7 @@ impl<T: Block> BlockCache<T> { } /// 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); @@ -78,11 +79,15 @@ impl<T: Block> BlockCache<T> { } /// 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(convert_mut::<T, U>) + self.cache.get_mut(&index).map(|block| { + block.dirty = true; + convert_mut::<T, U>(block) + }) } /// 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. @@ -97,7 +102,8 @@ impl<T: Block> BlockCache<T> { pub(crate) fn update_block<U: Block>(&mut self, block: CachedBlock<U>) -> bool { if self.cache.contains(&block.index) { - let data_block = convert::<U, T>(&block).clone(); + 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 { @@ -123,25 +129,29 @@ impl AyaFS { pub(crate) fn get_block<T: Block>(&mut self, index: usize) -> Option<&CachedBlock<T>> { self.data_bitmap .query(index) - .and_then(|| self.cached_blocks.get_block::<T>(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>> { self.data_bitmap .query(index) - .and_then(|| self.cached_blocks.get_block_mut::<T>(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 } pub(crate) fn peek_block<T: Block>(&self, index: usize) -> Option<&CachedBlock<T>> { self.data_bitmap .query(index) - .and_then(|| self.cached_blocks.peek_block::<T>(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 } pub(crate) fn peek_block_mut<T: Block>(&mut self, index: usize) -> Option<&mut CachedBlock<T>> { self.data_bitmap .query(index) - .and_then(|| self.cached_blocks.peek_block_mut::<T>(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 { diff --git a/src/memory/cached_inode.rs b/src/memory/cached_inode.rs index be87850..b1be2de 100644 --- a/src/memory/cached_inode.rs +++ b/src/memory/cached_inode.rs @@ -34,7 +34,7 @@ impl AyaFS { let mut new_inode = Inode::directory(permissions, uid, gid, utils::time_now(), flags, 0, 0, 0); // 分配第一个 direct block - new_inode.direct[0] = self.allocate_block_for(&mut new_inode).unwrap(); + (new_inode.direct[0], _) = self.allocate_block_for(&mut new_inode).unwrap(); new_inode.size = 2; // 在 direct block 里分配 . 和 .. if let Some(directory_block) = diff --git a/src/memory/dir_entry.rs b/src/memory/dir_entry.rs new file mode 100644 index 0000000..0ade23f --- /dev/null +++ b/src/memory/dir_entry.rs @@ -0,0 +1,103 @@ +use std::ffi::OsStr; +use std::os::unix::ffi::OsStrExt; +use libc::{c_int, ENOENT, ENOSPC}; +use crate::disk::block::{DirectoryBlock, DirectoryEntry}; +use crate::disk::inode::{Inode}; +use crate::AyaFS; + +impl AyaFS { + pub(crate) fn remove_direntry( + &mut self, + parent_inode: &mut Inode, + entry_index: u32 + ) -> Result<(), c_int> { + let block_index_within_inode = (entry_index / 15) as usize; + let entry_index_within_block = (entry_index % 15) as usize; + + match self.access_block_mut::<DirectoryBlock>(parent_inode, block_index_within_inode) { + Some(directory_block) => { + if directory_block.block.query(entry_index_within_block) { + directory_block.block.deallocate(entry_index_within_block); + directory_block.block.entries[entry_index_within_block] = DirectoryEntry::default(); + Ok(()) + } else { + Err(ENOENT) + } + } + None => Err(ENOENT), + } + } + + pub(crate) fn add_direntry( + &mut self, + parent_inode: &mut Inode, + child_inode_index: u32, + child_inode_name: &OsStr, + child_inode: &Inode, + ) -> Result<u32, c_int> { + // 找到第一个有空闲 DirEntry 的块, 从中分配一个 entry + let mut block_index_within_inode: usize = 0; + loop { + // 所有已经分配的块都用完, 需要额外分配一个块了 + if block_index_within_inode as u32 == parent_inode.n_blocks { + if self.allocate_block_for(parent_inode).is_none() { + return Err(ENOSPC); + } + } + // 寻找当前块里有没有空闲空间 + if let Some(directory_block) = self.access_block_mut::<DirectoryBlock>(parent_inode, block_index_within_inode) { + if let Some(entry_index_within_block) = directory_block.block.allocate() { + // 如果有空闲空间, 可以分配一个块 + let name_len = child_inode_name.len() as u8; + let file_type = child_inode.mode.into(); + let mut name = [0u8; 256]; + name.copy_from_slice(child_inode_name.as_bytes()); + + let dir_entry = DirectoryEntry { + inode: child_inode_index, + record_len: 264, + name_len, + file_type, + name, + }; + directory_block.block.entries[entry_index_within_block] = dir_entry; + let entry_index = block_index_within_inode * 15 + entry_index_within_block; + return Ok(entry_index as u32); + } + } + block_index_within_inode += 1; + }; + } + pub(crate) fn get_direntry( + &mut self, + parent_inode: &Inode, + entry_index: u32 + ) -> Option<DirectoryEntry> { + let block_index_within_inode = (entry_index / 15) as usize; + let entry_index_within_block = (entry_index % 15) as usize; + + self.access_block::<DirectoryBlock>(parent_inode, block_index_within_inode) + .and_then(|directory_block| { + if directory_block.block.query(entry_index_within_block) { + Some(directory_block.block.entries[entry_index_within_block].clone()) + } else { + None + } + }) + } + + // TODO 实现一个带 cache 的版本 + pub fn lookup_name(&mut self, parent_inode: &Inode, name: &OsStr) -> Result<(u32, u32, Inode), c_int> { + let mut entry_index = 0; + while entry_index < parent_inode.size { + if let Some(entry) = self.get_direntry(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/src/memory/inode_iter.rs b/src/memory/inode_iter.rs deleted file mode 100644 index d5909bc..0000000 --- a/src/memory/inode_iter.rs +++ /dev/null @@ -1,233 +0,0 @@ -use std::ffi::OsStr; -use std::os::unix::ffi::OsStrExt; -use libc::{c_int, ENOENT, ENOSPC}; -use crate::disk::block::{Block, DirectoryBlock, DirectoryEntry, DoubleIndirectBlock, IndirectBlock, TripleIndirectBlock}; -use crate::disk::inode::{Inode, DIRECT_NUMBER}; -use crate::{AyaFS, INODE_PER_BLOCK}; -use crate::memory::cached_block::CachedBlock; - -impl AyaFS { - pub(crate) fn access_block<T: Block>(&mut self, inode: &Inode, mut block_index_within_inode: usize) -> Option<&CachedBlock<T>> { - // direct block - if block_index_within_inode < DIRECT_NUMBER { - let block_index = inode.direct[block_index_within_inode] as usize; - return self.get_block::<T>(block_index); - } else { - block_index_within_inode -= DIRECT_NUMBER; - } - - // indirect block - let indirect_number = INODE_PER_BLOCK; - if block_index_within_inode < indirect_number { - return if let Some(indirect_block) = - self.get_block::<IndirectBlock>(inode.single_indirect as usize) - { - let block_index = indirect_block.block.entries[block_index_within_inode] as usize; - self.get_block::<T>(block_index) - } else { - None - }; - } else { - block_index_within_inode -= indirect_number; - } - - // double indirect block - let double_indirect_number = INODE_PER_BLOCK * INODE_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) - { - // 取出 double indirect block - let indirect_block_index = double_indirect_block.block.indirect - [block_index_within_inode / INODE_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 % INODE_PER_BLOCK] - as usize; - // 拿到 DirectoryBlock 的 index - return self.get_block::<T>(block_index); - } - } - 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 / (INODE_PER_BLOCK * INODE_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 % (INODE_PER_BLOCK * INODE_PER_BLOCK) - / INODE_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 % INODE_PER_BLOCK] - as usize; - // DirectoryBlock 的 index - return self.get_block::<T>(block_index); - } - } - } - - None - } - - pub(crate) fn add_direntry( - &mut self, - parent_inode: &mut Inode, - child_inode_index: u32, - child_inode_name: &OsStr, - child_inode: &Inode, - ) -> Result<u32, c_int> { - let entry_index = parent_inode.size; - let block_index_within_inode = (entry_index / 15) as usize; - let entry_index_within_block = (entry_index % 15) as usize; - - // TODO 如果 block 内 offset 是 0 （或者访问到 block_index_within_inode 无效?）则为 Inode 分配新的 block - - // TODO 把新的 entry 写到对应位置 - - Err(ENOSPC) - } - pub(crate) fn get_direntry( - &mut self, - inode: &Inode, - entry_index: u32 - ) -> Option<DirectoryEntry> { - let block_index_within_inode = (entry_index / 15) as usize; - let entry_index_within_block = (entry_index % 15) as usize; - - self.access_block::<DirectoryBlock>(inode, block_index_within_inode) - .map(|directory_block| { - directory_block.block.entries[entry_index_within_block].clone() - }) - } - - // pub(crate) fn get_direntry( - // &mut self, - // inode: &Inode, - // entry_index: u32, - // ) -> Option<DirectoryEntry> { - // // 每个 DirectoryBlock 里有 15 个 entry, 先确定 block 再确定 offset - // let mut block_index_within_inode = (entry_index / 15) as usize; - // let entry_index_within_block = (entry_index % 15) as usize; - // - // // direct block - // if block_index_within_inode < DIRECT_NUMBER { - // let block_index = inode.direct[block_index_within_inode] as usize; - // return self - // .get_block::<DirectoryBlock>(block_index) - // .map(|inode_block| inode_block.block.entries[entry_index_within_block].clone()); - // } else { - // block_index_within_inode -= DIRECT_NUMBER; - // } - // - // // indirect block - // let indirect_number = INODE_PER_BLOCK; - // if block_index_within_inode < indirect_number { - // return if let Some(indirect_block) = - // self.get_block::<IndirectBlock>(inode.single_indirect as usize) - // { - // let block_index = indirect_block.block.entries[block_index_within_inode] as usize; - // self.get_block::<DirectoryBlock>(block_index) - // .map(|inode_block| inode_block.block.entries[entry_index_within_block].clone()) - // } else { - // None - // }; - // } else { - // block_index_within_inode -= indirect_number; - // } - // - // // double indirect block - // let double_indirect_number = INODE_PER_BLOCK * INODE_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) - // { - // // 取出 double indirect block - // let indirect_block_index = double_indirect_block.block.indirect - // [block_index_within_inode / INODE_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 % INODE_PER_BLOCK] - // as usize; - // // 拿到 DirectoryBlock 的 index - // return self - // .get_block::<DirectoryBlock>(block_index) - // .map(|inode_block| { - // inode_block.block.entries[entry_index_within_block].clone() - // }); - // } - // } - // 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 / (INODE_PER_BLOCK * INODE_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 % (INODE_PER_BLOCK * INODE_PER_BLOCK) - // / INODE_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 % INODE_PER_BLOCK] - // as usize; - // // DirectoryBlock 的 index - // return self - // .get_block::<DirectoryBlock>(block_index) - // .map(|inode_block| { - // inode_block.block.entries[entry_index_within_block].clone() - // }); - // } - // } - // } - // None - // } - - // TODO 实现一个带 cache 的版本 - pub fn lookup_name(&mut self, parent_inode: &Inode, name: &OsStr) -> Result<(u32, Inode), c_int> { - let mut entry_index = 0; - while entry_index < parent_inode.size { - if let Some(entry) = self.get_direntry(parent_inode, entry_index) { - if entry.name() == name { - let inode = self.get_inode(entry.inode as usize).unwrap().clone(); - return Ok((entry.inode, inode)) - } - } - entry_index += 1; - } - Err(ENOENT) - } -} diff --git a/src/memory/mod.rs b/src/memory/mod.rs index dce7c42..4080114 100644 --- a/src/memory/mod.rs +++ b/src/memory/mod.rs @@ -2,4 +2,4 @@ /// This is where the crucial block and inode methods presented to upper calls implemented. pub mod cached_block; pub mod cached_inode; -mod inode_iter; +mod dir_entry; |