thin-provisioning-tools/tests/thin_shrink.rs
2020-06-26 16:44:47 +01:00

260 lines
6.4 KiB
Rust

use anyhow::Result;
use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
use rand::Rng;
use std::fs::OpenOptions;
use std::io::{Cursor, Read, Seek, SeekFrom, Write};
use thinp::file_utils;
use thinp::thin::xml::{self, Visit};
//------------------------------------
struct ThinBlock {
thin_id: u32,
thin_block: u64,
data_block: u64,
block_size: usize,
}
struct ThinReadRef {
pub data: Vec<u8>,
}
struct ThinWriteRef<'a, W: Write + Seek> {
file: &'a mut W,
pub data: Vec<u8>,
}
impl ThinBlock {
fn read_ref<R: Read + Seek>(&self, r: &mut R) -> Result<ThinReadRef> {
let mut rr = ThinReadRef {
data: vec![0; self.block_size],
};
r.seek(SeekFrom::Start(self.data_block * (self.block_size as u64)))?;
r.read_exact(&mut rr.data[0..])?;
Ok(rr)
}
fn zero_ref<'a, W: Write + Seek>(&self, w: &'a mut W) -> ThinWriteRef<'a, W> {
ThinWriteRef {
file: w,
data: vec![0; self.block_size],
}
}
fn write_ref<'a, W>(&self, w: &'a mut W) -> Result<ThinWriteRef<'a, W>>
where
W: Read + Write + Seek,
{
let mut data = vec![0; self.block_size];
w.seek(SeekFrom::Start(self.data_block * (self.block_size as u64)))?;
w.read_exact(&mut data[0..])?;
let wr = ThinWriteRef {
file: w,
data: vec![0; self.block_size],
};
Ok(wr)
}
}
impl<'a, W: Write + Seek> Drop for ThinWriteRef<'a, W> {
fn drop(&mut self) {
self.file.write_all(&self.data[0..]).unwrap();
}
}
//------------------------------------
trait ThinVisitor {
fn thin_block(&mut self, tb: &ThinBlock) -> Result<()>;
}
struct ThinXmlVisitor<'a, V: ThinVisitor> {
inner: &'a mut V,
block_size: Option<u32>,
thin_id: Option<u32>,
}
impl<'a, V: ThinVisitor> xml::MetadataVisitor for ThinXmlVisitor<'a, V> {
fn superblock_b(&mut self, sb: &xml::Superblock) -> Result<Visit> {
self.block_size = Some(sb.data_block_size);
Ok(Visit::Continue)
}
fn superblock_e(&mut self) -> Result<Visit> {
Ok(Visit::Continue)
}
fn device_b(&mut self, d: &xml::Device) -> Result<Visit> {
self.thin_id = Some(d.dev_id);
Ok(Visit::Continue)
}
fn device_e(&mut self) -> Result<Visit> {
Ok(Visit::Continue)
}
fn map(&mut self, m: &xml::Map) -> Result<Visit> {
for i in 0..m.len {
let block = ThinBlock {
thin_id: self.thin_id.unwrap(),
thin_block: m.thin_begin + i,
data_block: m.data_begin + i,
block_size: self.block_size.unwrap() as usize,
};
self.inner.thin_block(&block)?;
}
Ok(Visit::Continue)
}
fn eof(&mut self) -> Result<Visit> {
Ok(Visit::Stop)
}
}
fn thin_visit<R, M>(input: R, visitor: &mut M) -> Result<()>
where
R: Read,
M: ThinVisitor,
{
let mut xml_visitor = ThinXmlVisitor {
inner: visitor,
block_size: None,
thin_id: None,
};
xml::read(input, &mut xml_visitor)
}
//------------------------------------
// To test thin_shrink we'd like to stamp a known pattern across the
// provisioned areas of the thins in the pool, do the shrink, verify
// the patterns.
// A simple linear congruence generator used to create the data to
// go into the thin blocks.
struct Generator {
x: u64,
a: u64,
c: u64,
}
impl Generator {
fn new() -> Generator {
Generator {
x: 0,
a: 6364136223846793005,
c: 1442695040888963407,
}
}
fn step(&mut self) {
self.x = (self.a * self.x) + self.c
}
fn fill_buffer(&mut self, seed: u64, bytes: &mut [u8]) {
self.x = seed;
assert!(bytes.len() % 8 == 64);
let nr_words = bytes.len() / 8;
let mut out = Cursor::new(bytes);
for _ in 0..nr_words {
out.write_u64::<LittleEndian>(self.x).unwrap();
self.step();
}
}
fn verify_buffer(&mut self, seed: u64, bytes: &[u8]) {
self.x = seed;
assert!(bytes.len() % 8 == 64);
let nr_words = bytes.len() / 8;
let mut input = Cursor::new(bytes);
for _ in 0..nr_words {
let w = input.read_u64::<LittleEndian>().unwrap();
assert_eq!(w, self.x);
self.step();
}
}
}
//------------------------------------
struct Stamper<'a, W: Write + Seek> {
data_file: &'a mut W,
seed: u64,
}
impl<'a, W: Write + Seek> Stamper<'a, W> {
fn new(w: &'a mut W, seed: u64) -> Stamper<'a, W> {
Stamper { data_file: w, seed }
}
}
impl<'a, W: Write + Seek> ThinVisitor for Stamper<'a, W> {
fn thin_block(&mut self, b: &ThinBlock) -> Result<()> {
let mut wr = b.zero_ref(self.data_file);
let mut gen = Generator::new();
gen.fill_buffer(
self.seed ^ (b.thin_id as u64) ^ b.thin_block,
&mut wr.data[0..],
);
Ok(())
}
}
//------------------------------------
struct Verifier<'a, R: Read + Seek> {
data_file: &'a mut R,
seed: u64,
}
impl<'a, R: Read + Seek> Verifier<'a, R> {
fn new(r: &'a mut R, seed: u64) -> Verifier<'a, R> {
Verifier { data_file: r, seed }
}
}
impl<'a, R: Read + Seek> ThinVisitor for Verifier<'a, R> {
fn thin_block(&mut self, b: &ThinBlock) -> Result<()> {
let rr = b.read_ref(self.data_file)?;
let mut gen = Generator::new();
gen.verify_buffer(self.seed ^ (b.thin_id as u64) ^ b.thin_block, &rr.data[0..]);
Ok(())
}
}
//------------------------------------
fn create_data_file(xml_path: &str) -> Result<std::fs::File> {
let input = OpenOptions::new().read(true).write(false).open(xml_path)?;
let sb = xml::read_superblock(input)?;
let nr_blocks = sb.nr_data_blocks as u64;
let block_size = sb.data_block_size as u64 * 512;
let file = file_utils::temp_file_sized(nr_blocks * block_size)?;
Ok(file)
}
fn main(xml_path: &str) -> Result<()> {
let mut data_file = create_data_file(xml_path)?;
let mut xml_in = OpenOptions::new().read(true).write(false).open(xml_path)?;
let mut rng = rand::thread_rng();
let seed = rng.gen::<u64>();
let mut stamper = Stamper::new(&mut data_file, seed);
thin_visit(&mut xml_in, &mut stamper)?;
let mut verifier = Verifier::new(&mut data_file, seed);
thin_visit(&mut xml_in, &mut verifier)?;
Ok(())
}