[thin_check (rust)] start decoding the space maps.

This commit is contained in:
Joe Thornber 2020-08-06 07:51:48 +01:00
parent 904d9b0c84
commit 4a0582bb5d
7 changed files with 266 additions and 10 deletions

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@ -18,7 +18,7 @@ const ALIGN: usize = 4096;
#[derive(Debug)]
pub struct Block {
pub loc: u64,
data: *mut u8,
pub data: *mut u8,
}
impl Block {

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@ -18,6 +18,15 @@ pub trait Unpack {
Self: std::marker::Sized;
}
pub fn unpack<U: Unpack>(data: &[u8]) -> Result<U> {
match U::unpack(data) {
Err(_e) => {
Err(anyhow!("couldn't parse SMRoot"))
},
Ok((_i, v)) => Ok(v),
}
}
const NODE_HEADER_SIZE: usize = 32;
pub struct NodeHeader {
@ -164,6 +173,16 @@ impl Unpack for u64 {
}
}
impl Unpack for u32 {
fn disk_size() -> u32 {
4
}
fn unpack(i: &[u8]) -> IResult<&[u8], u32> {
le_u32(i)
}
}
//------------------------------------------
pub trait NodeVisitor<V: Unpack> {

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@ -1,2 +1,3 @@
pub mod btree;
pub mod space_map;

135
src/pdata/space_map.rs Normal file
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@ -0,0 +1,135 @@
use anyhow::{anyhow, Result};
use nom::{number::complete::*, IResult};
use crate::block_manager::*;
use crate::pdata::btree::Unpack;
//------------------------------------------
#[derive(Debug)]
pub struct SMRoot {
pub nr_blocks: u64,
pub nr_allocated: u64,
pub bitmap_root: u64,
pub ref_count_root: u64,
}
pub fn unpack_root(data: &[u8]) -> Result<SMRoot> {
match SMRoot::unpack(data) {
Err(_e) => {
Err(anyhow!("couldn't parse SMRoot"))
},
Ok((_i, v)) => Ok(v),
}
}
impl Unpack for SMRoot {
fn disk_size() -> u32 {
32
}
fn unpack(data: &[u8]) -> IResult<&[u8], SMRoot> {
let (i, nr_blocks) = le_u64(data)?;
let (i, nr_allocated) = le_u64(i)?;
let (i, bitmap_root) = le_u64(i)?;
let (i, ref_count_root) = le_u64(i)?;
Ok ((i, SMRoot {
nr_blocks,
nr_allocated,
bitmap_root,
ref_count_root,
}))
}
}
//------------------------------------------
#[derive(Clone, Debug)]
pub struct IndexEntry {
pub blocknr: u64,
pub nr_free: u32,
pub none_free_before: u32,
}
impl Unpack for IndexEntry {
fn disk_size() -> u32 {
16
}
fn unpack(data: &[u8]) -> IResult<&[u8], Self> {
let (i, blocknr) = le_u64(data)?;
let (i, nr_free) = le_u32(i)?;
let (i, none_free_before) = le_u32(i)?;
Ok((i, IndexEntry {blocknr, nr_free, none_free_before}))
}
}
//------------------------------------------
#[derive(Debug)]
pub struct BitmapHeader {
pub csum: u32,
pub not_used: u32,
pub blocknr: u64,
}
impl Unpack for BitmapHeader {
fn disk_size() -> u32 {
16
}
fn unpack(data: &[u8]) -> IResult<&[u8], Self> {
let (i, csum) = le_u32(data)?;
let (i, not_used) = le_u32(i)?;
let (i, blocknr) = le_u64(i)?;
Ok((i, BitmapHeader {csum, not_used, blocknr} ))
}
}
#[derive(Debug)]
pub enum BitmapEntry {
Small(u8),
Overflow,
}
#[derive(Debug)]
pub struct Bitmap {
pub header: BitmapHeader,
pub entries: Vec<BitmapEntry>,
}
impl Unpack for Bitmap {
fn disk_size() -> u32 {
BLOCK_SIZE as u32
}
fn unpack(data: &[u8]) -> IResult<&[u8], Self> {
let (mut i, header) = BitmapHeader::unpack(data)?;
let mut entries = Vec::new();
let nr_words = (BLOCK_SIZE - BitmapHeader::disk_size() as usize) / 8;
for _w in 0..nr_words {
let (tmp, mut word) = le_u64(i)?;
for _b in 0..32 {
let val = word & 0x3;
word = word >> 2;
if val < 3 {
entries.push(BitmapEntry::Small(val as u8));
} else {
entries.push(BitmapEntry::Overflow);
}
}
i = tmp;
}
Ok((i, Bitmap {header, entries}))
}
}
//------------------------------------------

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@ -133,6 +133,7 @@ impl<W: Write> xml::MetadataVisitor for Pass2<W> {
}
//---------------------------------------
type BlockRange = std::ops::Range<u64>;
fn bits_to_ranges(bits: &FixedBitSet) -> Vec<BlockRange> {

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@ -8,8 +8,10 @@ use std::time::Instant;
use threadpool::ThreadPool;
use crate::block_manager::{AsyncIoEngine, Block, IoEngine};
use crate::pdata::btree::{BTreeWalker, Node, NodeVisitor, Unpack};
use crate::pdata::btree::{BTreeWalker, Node, NodeVisitor, Unpack, unpack};
use crate::pdata::space_map::*;
use crate::thin::superblock::*;
use crate::checksum;
//------------------------------------------
@ -128,7 +130,64 @@ impl NodeVisitor<DeviceDetail> for DeviceVisitor {
for n in 0..keys.len() {
let k = keys[n] as u32;
let v = values[n].clone();
self.devs.insert(k, v.clone());
self.devs.insert(k, v);
}
}
Ok(())
}
}
//------------------------------------------
struct IndexVisitor {
entries: Vec<IndexEntry>,
}
impl NodeVisitor<IndexEntry> for IndexVisitor {
fn visit(&mut self, _w: &BTreeWalker, _b: &Block, node: &Node<IndexEntry>) -> Result<()> {
if let Node::Leaf {
header: _h,
keys,
values,
} = node {
for n in 0..keys.len() {
// FIXME: check keys are in incremental order
let v = values[n].clone();
self.entries.push(v);
}
}
Ok(())
}
}
//------------------------------------------
// FIXME: move to btree
struct ValueCollector<V> {
values: Vec<(u64, V)>,
}
impl<V> ValueCollector<V> {
fn new() -> ValueCollector<V> {
ValueCollector {
values: Vec::new(),
}
}
}
impl<V: Unpack + Clone> NodeVisitor<V> for ValueCollector<V> {
fn visit(&mut self, _w: &BTreeWalker, _b: &Block, node: &Node<V>) -> Result<()> {
if let Node::Leaf {
header: _h,
keys,
values,
} = node {
for n in 0..keys.len() {
let k = keys[n];
let v = values[n].clone();
self.values.push((k, v));
}
}
@ -145,6 +204,7 @@ pub fn check(dev: &Path) -> Result<()> {
let sb = read_superblock(engine.as_ref(), SUPERBLOCK_LOCATION)?;
eprintln!("{:?}", sb);
// device details
{
let mut visitor = DeviceVisitor::new();
let mut w = BTreeWalker::new(engine.clone(), false);
@ -152,6 +212,8 @@ pub fn check(dev: &Path) -> Result<()> {
println!("found {} devices", visitor.devs.len());
}
/*
// mapping top level
let mut roots = HashMap::new();
{
let mut visitor = TopLevelVisitor { roots: &mut roots };
@ -160,8 +222,9 @@ pub fn check(dev: &Path) -> Result<()> {
println!("read mapping tree in {} ms", now.elapsed().as_millis());
}
// FIXME: with a thread pool we need to return errors another way.
// mapping bottom level
{
// FIXME: with a thread pool we need to return errors another way.
let nr_workers = 4;
let pool = ThreadPool::new(nr_workers);
let seen = Arc::new(Mutex::new(FixedBitSet::with_capacity(
@ -179,6 +242,43 @@ pub fn check(dev: &Path) -> Result<()> {
pool.join();
}
*/
// data space map
{
let root = unpack::<SMRoot>(&sb.data_sm_root[0..])?;
eprintln!("data root: {:?}", root);
// overflow btree
let mut overflow: HashMap<u64, u32> = HashMap::new();
{
let mut v: ValueCollector<u32> = ValueCollector::new();
let mut w = BTreeWalker::new(engine.clone(), false);
w.walk(&mut v, root.ref_count_root)?;
for (k, v) in v.values {
overflow.insert(k, v);
}
}
eprintln!("{} overflow entries", overflow.len());
// Bitmaps
let mut v = IndexVisitor {entries: Vec::new()};
let mut w = BTreeWalker::new(engine.clone(), false);
let _result = w.walk(&mut v, root.bitmap_root);
eprintln!("{} index entries", v.entries.len());
for i in v.entries {
let mut b = Block::new(i.blocknr);
engine.read(&mut b)?;
if checksum::metadata_block_type(&b.get_data()) != checksum::BT::BITMAP {
return Err(anyhow!("Index entry points to block ({}) that isn't a bitmap", b.loc));
}
let bitmap = unpack::<Bitmap>(b.get_data())?;
}
}
Ok(())
}

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@ -14,8 +14,8 @@ pub struct Superblock {
pub time: u32,
pub transaction_id: u64,
pub metadata_snap: u64,
//data_sm_root: [u8; SPACE_MAP_ROOT_SIZE],
//metadata_sm_root: [u8; SPACE_MAP_ROOT_SIZE],
pub data_sm_root: Vec<u8>,
pub metadata_sm_root: Vec<u8>,
pub mapping_root: u64,
pub details_root: u64,
pub data_block_size: u32,
@ -59,8 +59,8 @@ fn unpack(data: &[u8]) -> IResult<&[u8], Superblock> {
let (i, time) = le_u32(i)?;
let (i, transaction_id) = le_u64(i)?;
let (i, metadata_snap) = le_u64(i)?;
let (i, _data_sm_root) = take(SPACE_MAP_ROOT_SIZE)(i)?;
let (i, _metadata_sm_root) = take(SPACE_MAP_ROOT_SIZE)(i)?;
let (i, data_sm_root) = take(SPACE_MAP_ROOT_SIZE)(i)?;
let (i, metadata_sm_root) = take(SPACE_MAP_ROOT_SIZE)(i)?;
let (i, mapping_root) = le_u64(i)?;
let (i, details_root) = le_u64(i)?;
let (i, data_block_size) = le_u32(i)?;
@ -76,8 +76,8 @@ fn unpack(data: &[u8]) -> IResult<&[u8], Superblock> {
time,
transaction_id,
metadata_snap,
//data_sm_root,
//metadata_sm_root,
data_sm_root: data_sm_root.to_vec(),
metadata_sm_root: metadata_sm_root.to_vec(),
mapping_root,
details_root,
data_block_size,