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use alloc::{
collections::{BTreeMap, VecDeque},
vec::Vec,
};
use core::{
cmp::min,
mem,
ops::{Deref, DerefMut},
};
use syscall::error::{
Error, Result, EEXIST, EINVAL, EIO, EISDIR, ENOENT, ENOSPC, ENOTDIR, ENOTEMPTY, ERANGE,
};
use crate::{
AllocEntry, AllocList, Allocator, BlockData, BlockPtr, BlockRaw, DirEntry, DirList, Disk,
FileSystem, Header, Node, NodeLevel, TreeData, TreePtr, ALLOC_LIST_ENTRIES, BLOCK_SIZE,
HEADER_RING,
};
pub struct Transaction<'a, D: Disk> {
fs: &'a mut FileSystem<D>,
//TODO: make private
pub header: Header,
//TODO: make private
pub header_changed: bool,
allocator: Allocator,
allocator_log: VecDeque<AllocEntry>,
deallocate: Vec<u64>,
write_cache: BTreeMap<u64, BlockRaw>,
}
impl<'a, D: Disk> Transaction<'a, D> {
pub(crate) fn new(fs: &'a mut FileSystem<D>) -> Self {
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let allocator = fs.allocator.clone();
Self {
fs,
header,
header_changed: false,
allocator,
allocator_log: VecDeque::new(),
deallocate: Vec::new(),
write_cache: BTreeMap::new(),
}
}
pub fn commit(mut self, squash: bool) -> Result<()> {
self.sync(squash)?;
self.fs.header = self.header;
self.fs.allocator = self.allocator;
Ok(())
}
// Unsafe because order must be done carefully and changes must be flushed to disk
unsafe fn allocate(&mut self) -> Result<u64> {
match self.allocator.allocate() {
Some(addr) => {
self.allocator_log.push_back(AllocEntry::new(addr, -1));
Ok(addr)
}
None => Err(Error::new(ENOSPC)),
}
}
// Unsafe because order must be done carefully and changes must be flushed to disk
unsafe fn deallocate(&mut self, addr: u64) {
//TODO: should we use some sort of not-null abstraction?
assert!(addr != 0);
// Remove from write_cache if it is there, since it no longer needs to be written
self.write_cache.remove(&addr);
// Search and remove the last matching entry in allocator_log
let mut found = false;
for i in (0..self.allocator_log.len()).rev() {
let entry = self.allocator_log[i];
if entry.addr() == addr && entry.count() == -1 {
found = true;
self.allocator_log.remove(i);
break;
}
}
if found {
// Deallocate immediately since it is an allocation that was not needed
self.allocator.deallocate(addr);
} else {
// Deallocate later when syncing filesystem, to avoid re-use
self.deallocate.push(addr);
}
}
fn deallocate_block<T>(&mut self, ptr: BlockPtr<T>) {
if !ptr.is_null() {
unsafe {
self.deallocate(ptr.addr());
}
}
}
fn sync_allocator(&mut self, squash: bool) -> Result<bool> {
let mut prev_ptr = BlockPtr::default();
if squash {
// Clear and rebuild alloc log
self.allocator_log.clear();
let levels = self.allocator.levels();
for level in (0..levels.len()).rev() {
let count = (1 << level) as i64;
'addrs: for &addr in levels[level].iter() {
for entry in self.allocator_log.iter_mut() {
if addr + count as u64 == entry.addr() {
// New entry is at start of existing entry
*entry = AllocEntry::new(addr, count + entry.count());
continue 'addrs;
} else if entry.addr() + entry.count() as u64 == addr {
// New entry is at end of existing entry
*entry = AllocEntry::new(entry.addr(), entry.count() + count);
continue 'addrs;
}
}
self.allocator_log.push_back(AllocEntry::new(addr, count));
}
}
// Prepare to deallocate old alloc blocks
let mut alloc_ptr = self.header.alloc;
while !alloc_ptr.is_null() {
let alloc = self.read_block(alloc_ptr)?;
self.deallocate.push(alloc.addr());
alloc_ptr = alloc.data().prev;
}
} else {
// Return if there are no log changes
if self.allocator_log.is_empty() && self.deallocate.is_empty() {
return Ok(false);
}
// Push old alloc block to front of allocator log
//TODO: just skip this if it is already full?
let alloc = self.read_block(self.header.alloc)?;
for i in (0..alloc.data().entries.len()).rev() {
let entry = alloc.data().entries[i];
if !entry.is_null() {
self.allocator_log.push_front(entry);
}
}
// Prepare to deallocate old alloc block
self.deallocate.push(alloc.addr());
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// Link to previous alloc block
prev_ptr = alloc.data().prev;
}
// Allocate required blocks, including CoW of current alloc tail
let mut new_blocks = Vec::new();
while new_blocks.len() * ALLOC_LIST_ENTRIES
<= self.allocator_log.len() + self.deallocate.len()
{
new_blocks.push(unsafe { self.allocate()? });
}
// De-allocate old blocks (after allocation to prevent re-use)
//TODO: optimize allocator log in memory
while let Some(addr) = self.deallocate.pop() {
self.allocator.deallocate(addr);
self.allocator_log.push_back(AllocEntry::new(addr, 1));
}
for new_block in new_blocks {
let mut alloc = BlockData::new(new_block, AllocList::default());
alloc.data_mut().prev = prev_ptr;
for entry in alloc.data_mut().entries.iter_mut() {
if let Some(log_entry) = self.allocator_log.pop_front() {
*entry = log_entry;
} else {
break;
}
}
prev_ptr = unsafe { self.write_block(alloc)? };
}
self.header.alloc = prev_ptr;
self.header_changed = true;
Ok(true)
}
//TODO: change this function, provide another way to squash, only write header in commit
pub fn sync(&mut self, squash: bool) -> Result<bool> {
// Make sure alloc is synced
self.sync_allocator(squash)?;
// Write all items in write cache
for (addr, raw) in self.write_cache.iter_mut() {
assert!(self.header_changed);
self.fs.encrypt(raw);
let count = unsafe { self.fs.disk.write_at(self.fs.block + addr, raw)? };
if count != mem::size_of::<BlockRaw>() {
// Read wrong number of bytes
log::error!("SYNC WRITE_CACHE: WRONG NUMBER OF BYTES");
return Err(Error::new(EIO));
}
}
self.write_cache.clear();
if !self.header_changed {
return Ok(false);
}
// Update header to next generation
let gen = self.header.update(self.fs.aes_opt.as_ref());
let gen_block = gen % HEADER_RING;
// Write header
let count = unsafe {
self.fs
.disk
.write_at(self.fs.block + gen_block, &self.header)?
};
if count != mem::size_of_val(&self.header) {
// Read wrong number of bytes
log::error!("SYNC: WRONG NUMBER OF BYTES");
return Err(Error::new(EIO));
}
self.header_changed = false;
Ok(true)
}
pub fn read_block<T: Default + DerefMut<Target = [u8]>>(
&mut self,
ptr: BlockPtr<T>,
) -> Result<BlockData<T>> {
if ptr.is_null() {
// Pointer is invalid (should this return None?)
log::error!("READ_BLOCK: POINTER IS NULL");
return Err(Error::new(ENOENT));
}
let mut data = T::default();
if let Some(raw) = self.write_cache.get(&ptr.addr()) {
data.copy_from_slice(raw);
} else {
let count = unsafe {
self.fs
.disk
.read_at(self.fs.block + ptr.addr(), &mut data)?
};
if count != mem::size_of::<T>() {
// Read wrong number of bytes
log::error!("READ_BLOCK: WRONG NUMBER OF BYTES");
return Err(Error::new(EIO));
}
self.fs.decrypt(&mut data);
}
let block = BlockData::new(ptr.addr(), data);
let block_ptr = block.create_ptr();
if block_ptr.hash() != ptr.hash() {
// Incorrect hash
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log::error!(
"READ_BLOCK: INCORRECT HASH {} != {} for block {}",
block_ptr.hash(),
ptr.hash(),
ptr.addr()
);
return Err(Error::new(EIO));
}
Ok(block)
}
/// Read block data or, if pointer is null, return default block data
///
/// # Safety
/// Unsafe because it creates strange BlockData types that must be swapped before use
unsafe fn read_block_or_default<T: Default + DerefMut<Target = [u8]>>(
&mut self,
ptr: BlockPtr<T>,
) -> Result<BlockData<T>> {
if ptr.is_null() {
Ok(BlockData::new(0, T::default()))
} else {
self.read_block(ptr)
}
}
/// Write block data to a new address, returning new address
pub fn sync_block<T: Deref<Target = [u8]>>(
&mut self,
mut block: BlockData<T>,
) -> Result<BlockPtr<T>> {
// Swap block to new address
let old_addr = block.swap_addr(unsafe { self.allocate()? });
// Deallocate old address (will only take effect after sync_allocator, which helps to
// prevent re-use before a new header is written
if old_addr != 0 {
unsafe {
self.deallocate(old_addr);
}
}
// Write new block
unsafe { self.write_block(block) }
}
/// Write block data, returning a calculated block pointer
///
/// # Safety
/// Unsafe to encourage CoW semantics
pub(crate) unsafe fn write_block<T: Deref<Target = [u8]>>(
&mut self,
block: BlockData<T>,
) -> Result<BlockPtr<T>> {
if block.addr() == 0 {
// Pointer is invalid
log::error!("WRITE_BLOCK: POINTER IS NULL");
return Err(Error::new(ENOENT));
}
//TODO: transmute?
let mut raw = BlockRaw::default();
raw.copy_from_slice(block.data());
self.write_cache.insert(block.addr(), raw);
Ok(block.create_ptr())
}
pub fn read_tree<T: Default + DerefMut<Target = [u8]>>(
&mut self,
ptr: TreePtr<T>,
) -> Result<TreeData<T>> {
if ptr.is_null() {
// ID is invalid (should this return None?)
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log::error!("READ_TREE: ID IS NULL");
return Err(Error::new(ENOENT));
}
let (i3, i2, i1, i0) = ptr.indexes();
let l3 = self.read_block(self.header.tree)?;
let l2 = self.read_block(l3.data().ptrs[i3])?;
let l1 = self.read_block(l2.data().ptrs[i2])?;
let l0 = self.read_block(l1.data().ptrs[i1])?;
let raw = self.read_block(l0.data().ptrs[i0])?;
//TODO: transmute instead of copy?
let mut data = T::default();
data.copy_from_slice(raw.data());
Ok(TreeData::new(ptr.id(), data))
}
//TODO: improve performance, reduce writes
pub fn insert_tree<T: Deref<Target = [u8]>>(
&mut self,
block_ptr: BlockPtr<T>,
) -> Result<TreePtr<T>> {
// Remember that if there is a free block at any level it will always sync when it
// allocates at the lowest level, so we can save a write by not writing each level as it
// is allocated.
unsafe {
let mut l3 = self.read_block(self.header.tree)?;
for i3 in 0..l3.data().ptrs.len() {
let mut l2 = self.read_block_or_default(l3.data().ptrs[i3])?;
for i2 in 0..l2.data().ptrs.len() {
let mut l1 = self.read_block_or_default(l2.data().ptrs[i2])?;
for i1 in 0..l1.data().ptrs.len() {
let mut l0 = self.read_block_or_default(l1.data().ptrs[i1])?;
for i0 in 0..l0.data().ptrs.len() {
let pn = l0.data().ptrs[i0];
// Skip if already in use
if !pn.is_null() {
continue;
}
let tree_ptr = TreePtr::from_indexes((i3, i2, i1, i0));
// Skip if this is a reserved node (null)
if tree_ptr.is_null() {
continue;
}
// Write updates to newly allocated blocks
l0.data_mut().ptrs[i0] = block_ptr.cast();
l1.data_mut().ptrs[i1] = self.sync_block(l0)?;
l2.data_mut().ptrs[i2] = self.sync_block(l1)?;
l3.data_mut().ptrs[i3] = self.sync_block(l2)?;
self.header.tree = self.sync_block(l3)?;
self.header_changed = true;
return Ok(tree_ptr);
}
}
}
}
}
Err(Error::new(ENOSPC))
}
pub fn sync_trees<T: Deref<Target = [u8]>>(&mut self, nodes: &[TreeData<T>]) -> Result<()> {
for node in nodes.iter().rev() {
let ptr = node.ptr();
if ptr.is_null() {
// ID is invalid
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log::error!("SYNC_TREE: ID IS NULL");
return Err(Error::new(ENOENT));
}
}
for node in nodes.iter().rev() {
let (i3, i2, i1, i0) = node.ptr().indexes();
let mut l3 = self.read_block(self.header.tree)?;
let mut l2 = self.read_block(l3.data().ptrs[i3])?;
let mut l1 = self.read_block(l2.data().ptrs[i2])?;
let mut l0 = self.read_block(l1.data().ptrs[i1])?;
let mut raw = self.read_block(l0.data().ptrs[i0])?;
// Return if data is equal
if raw.data().deref() == node.data().deref() {
continue;
}
//TODO: transmute instead of copy?
raw.data_mut().copy_from_slice(node.data());
// Write updates to newly allocated blocks
l0.data_mut().ptrs[i0] = self.sync_block(raw)?;
l1.data_mut().ptrs[i1] = self.sync_block(l0)?;
l2.data_mut().ptrs[i2] = self.sync_block(l1)?;
l3.data_mut().ptrs[i3] = self.sync_block(l2)?;
self.header.tree = self.sync_block(l3)?;
self.header_changed = true;
}
Ok(())
}
pub fn sync_tree<T: Deref<Target = [u8]>>(&mut self, node: TreeData<T>) -> Result<()> {
self.sync_trees(&[node])
}
//TODO: use more efficient methods for reading directories
pub fn child_nodes(
&mut self,
parent_ptr: TreePtr<Node>,
children: &mut Vec<DirEntry>,
) -> Result<()> {
let parent = self.read_tree(parent_ptr)?;
for block_offset in 0..(parent.data().size() / BLOCK_SIZE) {
let block_ptr = self.node_block_ptr(&parent, block_offset)?;
let dir_ptr: BlockPtr<DirList> = unsafe { block_ptr.cast() };
let dir = self.read_block(dir_ptr)?;
for entry in dir.data().entries {
let node_ptr = entry.node_ptr();
// Skip empty entries
if node_ptr.is_null() {
continue;
}
children.push(entry);
}
}
Ok(())
}
//TODO: improve performance (h-tree?)
pub fn find_node(&mut self, parent_ptr: TreePtr<Node>, name: &str) -> Result<TreeData<Node>> {
let parent = self.read_tree(parent_ptr)?;
for block_offset in 0..(parent.data().size() / BLOCK_SIZE) {
let block_ptr = self.node_block_ptr(&parent, block_offset)?;
let dir_ptr: BlockPtr<DirList> = unsafe { block_ptr.cast() };
let dir = self.read_block(dir_ptr)?;
for entry in dir.data().entries {
let node_ptr = entry.node_ptr();
// Skip empty entries
if node_ptr.is_null() {
continue;
}
// Return node pointer if name matches
if let Some(entry_name) = entry.name() {
if entry_name == name {
//TODO: Do not require read of node
return self.read_tree(node_ptr);
}
}
}
}
Err(Error::new(ENOENT))
}
//TODO: improve performance (h-tree?)
pub fn create_node(
&mut self,
parent_ptr: TreePtr<Node>,
name: &str,
mode: u16,
ctime: u64,
ctime_nsec: u32,
) -> Result<TreeData<Node>> {
if name.contains(':') {
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return Err(Error::new(EINVAL));
}
if self.find_node(parent_ptr, name).is_ok() {
return Err(Error::new(EEXIST));
}
unsafe {
let parent = self.read_tree(parent_ptr)?;
let node_block_data = BlockData::new(
self.allocate()?,
Node::new(
mode,
parent.data().uid(),
parent.data().gid(),
ctime,
ctime_nsec,
),
);
let node_block_ptr = self.write_block(node_block_data)?;
let node_ptr = self.insert_tree(node_block_ptr)?;
self.link_node(parent_ptr, name, node_ptr)?;
//TODO: do not re-read node
self.read_tree(node_ptr)
}
}
pub fn link_node(
&mut self,
parent_ptr: TreePtr<Node>,
name: &str,
node_ptr: TreePtr<Node>,
) -> Result<()> {
if name.contains(':') {
return Err(Error::new(EINVAL));
}
if self.find_node(parent_ptr, name).is_ok() {
return Err(Error::new(EEXIST));
}
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let mut parent = self.read_tree(parent_ptr)?;
let mut node = self.read_tree(node_ptr)?;
let links = node.data().links();
node.data_mut().set_links(links + 1);
let entry = DirEntry::new(node_ptr, name).ok_or(Error::new(EINVAL))?;
let block_end = parent.data().size() / BLOCK_SIZE;
for block_offset in 0..block_end {
let mut dir_block_ptr = self.node_block_ptr(&parent, block_offset)?;
let mut dir_ptr: BlockPtr<DirList> = unsafe { dir_block_ptr.cast() };
let mut dir = self.read_block(dir_ptr)?;
let mut dir_changed = false;
for old_entry in dir.data_mut().entries.iter_mut() {
// Skip filled entries
if !old_entry.node_ptr().is_null() {
continue;
}
*old_entry = entry;
dir_changed = true;
break;
}
if dir_changed {
dir_ptr = self.sync_block(dir)?;
dir_block_ptr = unsafe { dir_ptr.cast() };
self.sync_node_block_ptr(&mut parent, block_offset, dir_block_ptr)?;
self.sync_trees(&[parent, node])?;
return Ok(());
}
}
// Append a new dirlist, with first entry set to new entry
let mut dir = BlockData::new(unsafe { self.allocate()? }, DirList::default());
dir.data_mut().entries[0] = entry;
let dir_ptr = unsafe { self.write_block(dir)? };
let dir_block_ptr: BlockPtr<BlockRaw> = unsafe { dir_ptr.cast() };
self.sync_node_block_ptr(&mut parent, block_end, dir_block_ptr)?;
parent.data_mut().set_size((block_end + 1) * BLOCK_SIZE);
self.sync_trees(&[parent, node])?;
Ok(())
}
pub fn remove_node(&mut self, parent_ptr: TreePtr<Node>, name: &str, mode: u16) -> Result<()> {
let mut parent = self.read_tree(parent_ptr)?;
let blocks = parent.data().size() / BLOCK_SIZE;
for block_offset in 0..blocks {
let mut dir_block_ptr = self.node_block_ptr(&parent, block_offset)?;
let mut dir_ptr: BlockPtr<DirList> = unsafe { dir_block_ptr.cast() };
let mut dir = self.read_block(dir_ptr)?;
let mut node_opt = None;
for entry in dir.data_mut().entries.iter_mut() {
let node_ptr = entry.node_ptr();
// Skip empty entries
if node_ptr.is_null() {
continue;
}
// Check if name matches
if let Some(entry_name) = entry.name() {
if entry_name == name {
// Read node and test type against requested type
let node = self.read_tree(node_ptr)?;
if node.data().mode() & Node::MODE_TYPE == mode {
if node.data().is_dir()
&& node.data().size() > 0
&& node.data().links() == 1
{
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// Tried to remove directory that still has entries
return Err(Error::new(ENOTEMPTY));
}
// Save node and clear entry
node_opt = Some(node);
*entry = DirEntry::default();
break;
} else if node.data().is_dir() {
// Found directory instead of requested type
return Err(Error::new(EISDIR));
} else {
// Did not find directory when requested
return Err(Error::new(ENOTDIR));
}
}
}
}
if let Some(mut node) = node_opt {
let links = node.data().links();
if links > 1 {
node.data_mut().set_links(links - 1);
} else {
node.data_mut().set_links(0);
self.truncate_node_inner(&mut node, 0)?;
}
if block_offset == blocks - 1 && dir.data().is_empty() {
// Remove empty parent block, if it is at the end
self.remove_node_block_ptr(&mut parent, block_offset)?;
parent.data_mut().set_size(block_offset * BLOCK_SIZE);
} else {
// Save new parent block
dir_ptr = self.sync_block(dir)?;
dir_block_ptr = unsafe { dir_ptr.cast() };
self.sync_node_block_ptr(&mut parent, block_offset, dir_block_ptr)?;
}
// Sync both parent and node at the same time
self.sync_trees(&[parent, node])?;
return Ok(());
}
}
Err(Error::new(ENOENT))
}
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pub fn rename_node(
&mut self,
orig_parent_ptr: TreePtr<Node>,
orig_name: &str,
new_parent_ptr: TreePtr<Node>,
new_name: &str,
) -> Result<()> {
let orig = self.find_node(orig_parent_ptr, orig_name)?;
//TODO: only allow ENOENT as an error?
if let Ok(new) = self.find_node(new_parent_ptr, new_name) {
// Move to same name, return
if new.id() == orig.id() {
return Ok(());
}
// Remove new name
self.remove_node(
new_parent_ptr,
new_name,
new.data().mode() & Node::MODE_TYPE,
)?;
}
// Link original file to new name
self.link_node(new_parent_ptr, new_name, orig.ptr())?;
// Remove original file
self.remove_node(
orig_parent_ptr,
orig_name,
orig.data().mode() & Node::MODE_TYPE,
)?;
Ok(())
}
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fn node_block_ptr(
&mut self,
node: &TreeData<Node>,
block_offset: u64,
) -> Result<BlockPtr<BlockRaw>> {
match NodeLevel::new(block_offset).ok_or(Error::new(ERANGE))? {
NodeLevel::L0(i0) => Ok(node.data().level0[i0]),
NodeLevel::L1(i1, i0) => {
let l0 = self.read_block(node.data().level1[i1])?;
Ok(l0.data().ptrs[i0])
}
NodeLevel::L2(i2, i1, i0) => {
let l1 = self.read_block(node.data().level2[i2])?;
let l0 = self.read_block(l1.data().ptrs[i1])?;
Ok(l0.data().ptrs[i0])
}
NodeLevel::L3(i3, i2, i1, i0) => {
let l2 = self.read_block(node.data().level3[i3])?;
let l1 = self.read_block(l2.data().ptrs[i2])?;
let l0 = self.read_block(l1.data().ptrs[i1])?;
Ok(l0.data().ptrs[i0])
}
NodeLevel::L4(i4, i3, i2, i1, i0) => {
let l3 = self.read_block(node.data().level4[i4])?;
let l2 = self.read_block(l3.data().ptrs[i3])?;
let l1 = self.read_block(l2.data().ptrs[i2])?;
let l0 = self.read_block(l1.data().ptrs[i1])?;
Ok(l0.data().ptrs[i0])
}
}
}
fn remove_node_block_ptr(
&mut self,
node: &mut TreeData<Node>,
block_offset: u64,
) -> Result<()> {
match NodeLevel::new(block_offset).ok_or(Error::new(ERANGE))? {
NodeLevel::L0(i0) => {
self.deallocate_block(node.data_mut().level0[i0].clear());
}
NodeLevel::L1(i1, i0) => {
let mut l0 = self.read_block(node.data().level1[i1])?;
self.deallocate_block(l0.data_mut().ptrs[i0].clear());
if l0.data().is_empty() {
self.deallocate_block(node.data_mut().level1[i1].clear());
} else {
node.data_mut().level1[i1] = self.sync_block(l0)?;
}
}
NodeLevel::L2(i2, i1, i0) => {
let mut l1 = self.read_block(node.data().level2[i2])?;
let mut l0 = self.read_block(l1.data().ptrs[i1])?;
self.deallocate_block(l0.data_mut().ptrs[i0].clear());
if l0.data().is_empty() {
self.deallocate_block(l1.data_mut().ptrs[i1].clear());
} else {
l1.data_mut().ptrs[i1] = self.sync_block(l0)?;
}
if l1.data().is_empty() {
self.deallocate_block(node.data_mut().level2[i2].clear());
} else {
node.data_mut().level2[i2] = self.sync_block(l1)?;
}
}
NodeLevel::L3(i3, i2, i1, i0) => {
let mut l2 = self.read_block(node.data().level3[i3])?;
let mut l1 = self.read_block(l2.data().ptrs[i2])?;
let mut l0 = self.read_block(l1.data().ptrs[i1])?;
self.deallocate_block(l0.data_mut().ptrs[i0].clear());
if l0.data().is_empty() {
self.deallocate_block(l1.data_mut().ptrs[i1].clear());
} else {
l1.data_mut().ptrs[i1] = self.sync_block(l0)?;
}
if l1.data().is_empty() {
self.deallocate_block(l2.data_mut().ptrs[i2].clear());
} else {
l2.data_mut().ptrs[i2] = self.sync_block(l1)?;
}
if l2.data().is_empty() {
self.deallocate_block(node.data_mut().level3[i3].clear());
} else {
node.data_mut().level3[i3] = self.sync_block(l2)?;
}
}
NodeLevel::L4(i4, i3, i2, i1, i0) => {
let mut l3 = self.read_block(node.data().level4[i4])?;
let mut l2 = self.read_block(l3.data().ptrs[i3])?;
let mut l1 = self.read_block(l2.data().ptrs[i2])?;
let mut l0 = self.read_block(l1.data().ptrs[i1])?;
self.deallocate_block(l0.data_mut().ptrs[i0].clear());
if l0.data().is_empty() {
self.deallocate_block(l1.data_mut().ptrs[i1].clear());
} else {
l1.data_mut().ptrs[i1] = self.sync_block(l0)?;
}
if l1.data().is_empty() {
self.deallocate_block(l2.data_mut().ptrs[i2].clear());
} else {
l2.data_mut().ptrs[i2] = self.sync_block(l1)?;
}
if l2.data().is_empty() {
self.deallocate_block(l3.data_mut().ptrs[i3].clear());
} else {
l3.data_mut().ptrs[i3] = self.sync_block(l2)?;
}
if l3.data().is_empty() {
self.deallocate_block(node.data_mut().level4[i4].clear());
} else {
node.data_mut().level4[i4] = self.sync_block(l3)?;
}
}
}
Ok(())
}
fn sync_node_block_ptr(
&mut self,
node: &mut TreeData<Node>,
block_offset: u64,
ptr: BlockPtr<BlockRaw>,
) -> Result<()> {
unsafe {
match NodeLevel::new(block_offset).ok_or(Error::new(ERANGE))? {
NodeLevel::L0(i0) => {
node.data_mut().level0[i0] = ptr;
}
NodeLevel::L1(i1, i0) => {
let mut l0 = self.read_block_or_default(node.data().level1[i1])?;
l0.data_mut().ptrs[i0] = ptr;
node.data_mut().level1[i1] = self.sync_block(l0)?;
}
NodeLevel::L2(i2, i1, i0) => {
let mut l1 = self.read_block_or_default(node.data().level2[i2])?;
let mut l0 = self.read_block_or_default(l1.data().ptrs[i1])?;
l0.data_mut().ptrs[i0] = ptr;
l1.data_mut().ptrs[i1] = self.sync_block(l0)?;
node.data_mut().level2[i2] = self.sync_block(l1)?;
}
NodeLevel::L3(i3, i2, i1, i0) => {
let mut l2 = self.read_block_or_default(node.data().level3[i3])?;
let mut l1 = self.read_block_or_default(l2.data().ptrs[i2])?;
let mut l0 = self.read_block_or_default(l1.data().ptrs[i1])?;
l0.data_mut().ptrs[i0] = ptr;
l1.data_mut().ptrs[i1] = self.sync_block(l0)?;
l2.data_mut().ptrs[i2] = self.sync_block(l1)?;
node.data_mut().level3[i3] = self.sync_block(l2)?;
}
NodeLevel::L4(i4, i3, i2, i1, i0) => {
let mut l3 = self.read_block_or_default(node.data().level4[i4])?;
let mut l2 = self.read_block_or_default(l3.data().ptrs[i3])?;
let mut l1 = self.read_block_or_default(l2.data().ptrs[i2])?;
let mut l0 = self.read_block_or_default(l1.data().ptrs[i1])?;
l0.data_mut().ptrs[i0] = ptr;
l1.data_mut().ptrs[i1] = self.sync_block(l0)?;
l2.data_mut().ptrs[i2] = self.sync_block(l1)?;
l3.data_mut().ptrs[i3] = self.sync_block(l2)?;
node.data_mut().level4[i4] = self.sync_block(l3)?;
}
}
}
Ok(())
}
pub fn read_node_inner(
&mut self,
node: &TreeData<Node>,
mut offset: u64,
buf: &mut [u8],
) -> Result<usize> {
let node_size = node.data().size();
let mut i = 0;
while i < buf.len() && offset < node_size {
let block_ptr = self.node_block_ptr(node, offset / BLOCK_SIZE)?;
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let block = self.read_block(block_ptr)?;
let j = (offset % BLOCK_SIZE) as usize;
let len = min(
buf.len() - i,
min(BLOCK_SIZE - j as u64, node_size - offset) as usize,
);
buf[i..i + len].copy_from_slice(&block.data()[j..j + len]);
i += len;
offset += len as u64;
}
Ok(i)
}
pub fn read_node(
&mut self,
node_ptr: TreePtr<Node>,
offset: u64,
buf: &mut [u8],
atime: u64,
atime_nsec: u32,
) -> Result<usize> {
let mut node = self.read_tree(node_ptr)?;
let mut node_changed = false;
let i = self.read_node_inner(&node, offset, buf)?;
if i > 0 {
let node_atime = node.data().atime();
if atime > node_atime.0 || (atime == node_atime.0 && atime_nsec > node_atime.1) {
let is_old = atime - node_atime.0 > 3600; // Last read was more than a day ago
if is_old {
node.data_mut().set_atime(atime, atime_nsec);
node_changed = true;
}
}
}
if node_changed {
self.sync_tree(node)?;
}
Ok(i)
}
pub fn truncate_node_inner(&mut self, node: &mut TreeData<Node>, size: u64) -> Result<bool> {
let old_size = node.data().size();
// Size already matches, return
if old_size == size {
return Ok(false);
}
if old_size < size {
// If size is smaller, write zeroes until the size matches
let zeroes = [0; BLOCK_SIZE as usize];
let mut offset = old_size;
while offset < size {
let start = offset % BLOCK_SIZE;
let end = if offset / BLOCK_SIZE == size / BLOCK_SIZE {
size % BLOCK_SIZE
} else {
BLOCK_SIZE
};
self.write_node_inner(node, &mut offset, &zeroes[start as usize..end as usize])?;
}
assert_eq!(offset, size);
} else {
// Deallocate blocks
for block in ((size + BLOCK_SIZE - 1) / BLOCK_SIZE..old_size / BLOCK_SIZE).rev() {
self.remove_node_block_ptr(node, block)?;
}
}
// Update size
node.data_mut().set_size(size);
Ok(true)
}
pub fn truncate_node(
&mut self,
node_ptr: TreePtr<Node>,
size: u64,
mtime: u64,
mtime_nsec: u32,
) -> Result<()> {
let mut node = self.read_tree(node_ptr)?;
if self.truncate_node_inner(&mut node, size)? {
let node_mtime = node.data().mtime();
if mtime > node_mtime.0 || (mtime == node_mtime.0 && mtime_nsec > node_mtime.1) {
node.data_mut().set_mtime(mtime, mtime_nsec);
}
self.sync_tree(node)?;
}
Ok(())
}