935 lines
23 KiB
Rust
935 lines
23 KiB
Rust
use anyhow::{anyhow, Result};
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use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
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use rand::prelude::*;
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use std::collections::VecDeque;
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use std::fs::OpenOptions;
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use std::io::{Cursor, Read, Seek, SeekFrom, Write};
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use std::ops::Range;
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use std::path::{Path, PathBuf};
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use tempfile::tempdir;
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use thinp::file_utils;
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use thinp::thin::xml::{self, Visit};
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//------------------------------------
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#[derive(Debug)]
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struct ThinBlock {
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thin_id: u32,
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thin_block: u64,
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data_block: u64,
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block_size: usize,
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}
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struct ThinReadRef {
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pub data: Vec<u8>,
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}
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struct ThinWriteRef<'a, W: Write + Seek> {
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file: &'a mut W,
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block_byte: u64,
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pub data: Vec<u8>,
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}
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impl ThinBlock {
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fn read_ref<R: Read + Seek>(&self, r: &mut R) -> Result<ThinReadRef> {
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let mut rr = ThinReadRef {
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data: vec![0; self.block_size * 512],
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};
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let byte = self.data_block * (self.block_size as u64) * 512;
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r.seek(SeekFrom::Start(byte))?;
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r.read_exact(&mut rr.data)?;
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Ok(rr)
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}
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fn zero_ref<'a, W: Write + Seek>(&self, w: &'a mut W) -> ThinWriteRef<'a, W> {
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ThinWriteRef {
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file: w,
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block_byte: self.data_block * (self.block_size as u64) * 512,
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data: vec![0; self.block_size * 512],
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}
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}
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//fn write_ref<'a, W>(&self, w: &'a mut W) -> Result<ThinWriteRef<'a, W>>
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//where
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//W: Read + Write + Seek,
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//{
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//let mut data = vec![0; self.block_size];
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//w.seek(SeekFrom::Start(self.data_block * (self.block_size as u64)))?;
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//w.read_exact(&mut data[0..])?;
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//
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//let wr = ThinWriteRef {
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//file: w,
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//block_byte: self.data_block * (self.block_size as u64),
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//data: vec![0; self.block_size],
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//};
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//
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//Ok(wr)
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//}
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}
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impl<'a, W: Write + Seek> Drop for ThinWriteRef<'a, W> {
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fn drop(&mut self) {
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// FIXME: We shouldn't panic in a drop function, so any IO
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// errors will have to make their way back to the user
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// another way (eg, via a flush() method).
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self.file.seek(SeekFrom::Start(self.block_byte)).unwrap();
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self.file.write_all(&self.data).unwrap();
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}
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}
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//------------------------------------
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trait ThinVisitor {
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fn thin_block(&mut self, tb: &ThinBlock) -> Result<()>;
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}
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struct ThinXmlVisitor<'a, V: ThinVisitor> {
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inner: &'a mut V,
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block_size: Option<u32>,
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thin_id: Option<u32>,
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}
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impl<'a, V: ThinVisitor> xml::MetadataVisitor for ThinXmlVisitor<'a, V> {
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fn superblock_b(&mut self, sb: &xml::Superblock) -> Result<Visit> {
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self.block_size = Some(sb.data_block_size);
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Ok(Visit::Continue)
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}
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fn superblock_e(&mut self) -> Result<Visit> {
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Ok(Visit::Continue)
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}
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fn device_b(&mut self, d: &xml::Device) -> Result<Visit> {
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self.thin_id = Some(d.dev_id);
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Ok(Visit::Continue)
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}
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fn device_e(&mut self) -> Result<Visit> {
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Ok(Visit::Continue)
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}
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fn map(&mut self, m: &xml::Map) -> Result<Visit> {
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for i in 0..m.len {
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let block = ThinBlock {
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thin_id: self.thin_id.unwrap(),
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thin_block: m.thin_begin + i,
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data_block: m.data_begin + i,
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block_size: self.block_size.unwrap() as usize,
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};
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self.inner.thin_block(&block)?;
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}
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Ok(Visit::Continue)
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}
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fn eof(&mut self) -> Result<Visit> {
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Ok(Visit::Stop)
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}
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}
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fn thin_visit<R, M>(input: R, visitor: &mut M) -> Result<()>
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where
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R: Read,
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M: ThinVisitor,
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{
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let mut xml_visitor = ThinXmlVisitor {
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inner: visitor,
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block_size: None,
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thin_id: None,
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};
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xml::read(input, &mut xml_visitor)
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}
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//------------------------------------
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// To test thin_shrink we'd like to stamp a known pattern across the
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// provisioned areas of the thins in the pool, do the shrink, verify
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// the patterns.
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// A simple linear congruence generator used to create the data to
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// go into the thin blocks.
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struct Generator {
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x: u64,
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a: u64,
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c: u64,
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}
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impl Generator {
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fn new() -> Generator {
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Generator {
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x: 0,
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a: 6364136223846793005,
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c: 1442695040888963407,
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}
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}
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fn step(&mut self) {
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self.x = self.a.wrapping_mul(self.x).wrapping_add(self.c)
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}
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fn fill_buffer(&mut self, seed: u64, bytes: &mut [u8]) -> Result<()> {
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self.x = seed;
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assert!(bytes.len() % 8 == 0);
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let nr_words = bytes.len() / 8;
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let mut out = Cursor::new(bytes);
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for _ in 0..nr_words {
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out.write_u64::<LittleEndian>(self.x)?;
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self.step();
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}
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Ok(())
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}
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fn verify_buffer(&mut self, seed: u64, bytes: &[u8]) -> Result<bool> {
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self.x = seed;
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assert!(bytes.len() % 8 == 0);
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let nr_words = bytes.len() / 8;
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let mut input = Cursor::new(bytes);
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for _ in 0..nr_words {
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let w = input.read_u64::<LittleEndian>()?;
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if w != self.x {
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eprintln!("{} != {}", w, self.x);
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return Ok(false);
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}
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self.step();
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}
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Ok(true)
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}
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}
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//------------------------------------
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struct Stamper<'a, W: Write + Seek> {
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data_file: &'a mut W,
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seed: u64,
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}
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impl<'a, W: Write + Seek> Stamper<'a, W> {
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fn new(w: &'a mut W, seed: u64) -> Stamper<'a, W> {
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Stamper { data_file: w, seed }
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}
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}
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impl<'a, W: Write + Seek> ThinVisitor for Stamper<'a, W> {
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fn thin_block(&mut self, b: &ThinBlock) -> Result<()> {
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let mut wr = b.zero_ref(self.data_file);
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let mut gen = Generator::new();
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gen.fill_buffer(self.seed ^ (b.thin_id as u64) ^ b.thin_block, &mut wr.data)?;
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Ok(())
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}
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}
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//------------------------------------
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struct Verifier<'a, R: Read + Seek> {
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data_file: &'a mut R,
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seed: u64,
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}
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impl<'a, R: Read + Seek> Verifier<'a, R> {
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fn new(r: &'a mut R, seed: u64) -> Verifier<'a, R> {
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Verifier { data_file: r, seed }
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}
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}
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impl<'a, R: Read + Seek> ThinVisitor for Verifier<'a, R> {
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fn thin_block(&mut self, b: &ThinBlock) -> Result<()> {
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let rr = b.read_ref(self.data_file)?;
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let mut gen = Generator::new();
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if !gen.verify_buffer(self.seed ^ (b.thin_id as u64) ^ b.thin_block, &rr.data)? {
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return Err(anyhow!("data verify failed for {:?}", b));
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}
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Ok(())
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}
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}
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//------------------------------------
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fn mk_path(dir: &Path, file: &str) -> PathBuf {
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let mut p = PathBuf::new();
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p.push(dir);
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p.push(PathBuf::from(file));
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p
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}
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fn generate_xml(path: &Path, g: &mut dyn Scenario) -> Result<()> {
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let xml_out = OpenOptions::new()
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.read(false)
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.write(true)
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.create(true)
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.truncate(true)
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.open(path)?;
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let mut w = xml::XmlWriter::new(xml_out);
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g.generate_xml(&mut w)
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}
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fn create_data_file(data_path: &Path, xml_path: &Path) -> Result<()> {
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let input = OpenOptions::new().read(true).write(false).open(xml_path)?;
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let sb = xml::read_superblock(input)?;
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let nr_blocks = sb.nr_data_blocks as u64;
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let block_size = sb.data_block_size as u64 * 512;
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let _file = file_utils::create_sized_file(data_path, nr_blocks * block_size)?;
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Ok(())
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}
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fn stamp(xml_path: &Path, data_path: &Path, seed: u64) -> Result<()> {
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let mut data = OpenOptions::new()
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.read(false)
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.write(true)
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.open(&data_path)?;
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let xml = OpenOptions::new().read(true).write(false).open(&xml_path)?;
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let mut stamper = Stamper::new(&mut data, seed);
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thin_visit(xml, &mut stamper)
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}
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fn verify(xml_path: &Path, data_path: &Path, seed: u64) -> Result<()> {
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let mut data = OpenOptions::new()
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.read(true)
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.write(false)
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.open(&data_path)?;
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let xml = OpenOptions::new().read(true).write(false).open(&xml_path)?;
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let mut verifier = Verifier::new(&mut data, seed);
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thin_visit(xml, &mut verifier)
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}
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trait Scenario {
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fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()>;
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fn get_new_nr_blocks(&self) -> u64;
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}
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fn test_shrink(scenario: &mut dyn Scenario) -> Result<()> {
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let dir = tempdir()?;
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let xml_before = mk_path(dir.path(), "before.xml");
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let xml_after = mk_path(dir.path(), "after.xml");
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let data_path = mk_path(dir.path(), "metadata.bin");
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generate_xml(&xml_before, scenario)?;
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create_data_file(&data_path, &xml_before)?;
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let mut rng = rand::thread_rng();
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let seed = rng.gen::<u64>();
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stamp(&xml_before, &data_path, seed)?;
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verify(&xml_before, &data_path, seed)?;
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let new_nr_blocks = scenario.get_new_nr_blocks();
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thinp::shrink::toplevel::shrink(&xml_before, &xml_after, &data_path, new_nr_blocks, true)?;
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verify(&xml_after, &data_path, seed)?;
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Ok(())
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}
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//------------------------------------
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fn common_sb(nr_blocks: u64) -> xml::Superblock {
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xml::Superblock {
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uuid: "".to_string(),
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time: 0,
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transaction: 0,
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flags: None,
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version: None,
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data_block_size: 32,
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nr_data_blocks: nr_blocks,
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metadata_snap: None,
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}
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}
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struct EmptyPoolS {}
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impl Scenario for EmptyPoolS {
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fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()> {
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v.superblock_b(&common_sb(1024))?;
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v.superblock_e()?;
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Ok(())
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}
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fn get_new_nr_blocks(&self) -> u64 {
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512
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}
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}
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#[test]
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fn shrink_empty_pool() -> Result<()> {
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let mut s = EmptyPoolS {};
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test_shrink(&mut s)
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}
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//------------------------------------
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struct SingleThinS {
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offset: u64,
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len: u64,
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old_nr_data_blocks: u64,
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new_nr_data_blocks: u64,
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}
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impl SingleThinS {
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fn new(offset: u64, len: u64, old_nr_data_blocks: u64, new_nr_data_blocks: u64) -> Self {
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SingleThinS {
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offset,
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len,
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old_nr_data_blocks,
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new_nr_data_blocks,
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}
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}
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}
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impl Scenario for SingleThinS {
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fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()> {
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v.superblock_b(&common_sb(self.old_nr_data_blocks))?;
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v.device_b(&xml::Device {
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dev_id: 0,
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mapped_blocks: self.len,
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transaction: 0,
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creation_time: 0,
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snap_time: 0,
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})?;
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v.map(&xml::Map {
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thin_begin: 0,
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data_begin: self.offset,
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time: 0,
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len: self.len,
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})?;
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v.device_e()?;
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v.superblock_e()?;
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Ok(())
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}
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fn get_new_nr_blocks(&self) -> u64 {
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self.new_nr_data_blocks
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}
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}
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#[test]
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fn shrink_single_no_move_1() -> Result<()> {
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let mut s = SingleThinS::new(0, 1024, 2048, 1280);
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test_shrink(&mut s)
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}
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#[test]
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fn shrink_single_no_move_2() -> Result<()> {
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let mut s = SingleThinS::new(100, 1024, 2048, 1280);
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test_shrink(&mut s)
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}
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#[test]
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fn shrink_single_no_move_3() -> Result<()> {
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let mut s = SingleThinS::new(1024, 1024, 2048, 2048);
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test_shrink(&mut s)
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}
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#[test]
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fn shrink_single_partial_move() -> Result<()> {
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let mut s = SingleThinS::new(1024, 1024, 2048, 1280);
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test_shrink(&mut s)
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}
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#[test]
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fn shrink_single_total_move() -> Result<()> {
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let mut s = SingleThinS::new(2048, 1024, 1024 + 2048, 1280);
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test_shrink(&mut s)
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}
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#[test]
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fn shrink_insufficient_space() -> Result<()> {
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let mut s = SingleThinS::new(0, 2048, 3000, 1280);
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match test_shrink(&mut s) {
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Ok(_) => Err(anyhow!("Shrink unexpectedly succeeded")),
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Err(_) => Ok(()),
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}
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}
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//------------------------------------
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struct FragmentedS {
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nr_thins: u32,
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thin_size: u64,
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old_nr_data_blocks: u64,
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new_nr_data_blocks: u64,
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}
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impl FragmentedS {
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fn new(nr_thins: u32, thin_size: u64) -> Self {
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let old_size = (nr_thins as u64) * thin_size;
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FragmentedS {
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nr_thins,
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thin_size,
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old_nr_data_blocks: (nr_thins as u64) * thin_size,
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new_nr_data_blocks: old_size * 3 / 4,
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}
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}
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}
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|
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#[derive(Clone)]
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struct ThinRun {
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thin_id: u32,
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thin_begin: u64,
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len: u64,
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}
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|
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#[derive(Clone, Debug, Copy)]
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struct MappedRun {
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thin_id: u32,
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thin_begin: u64,
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data_begin: u64,
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len: u64,
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}
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fn mk_runs(thin_id: u32, total_len: u64, run_len: std::ops::Range<u64>) -> Vec<ThinRun> {
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let mut runs = Vec::new();
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let mut b = 0u64;
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while b < total_len {
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let len = u64::min(
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total_len - b,
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thread_rng().gen_range(run_len.start, run_len.end),
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);
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runs.push(ThinRun {
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thin_id: thin_id,
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thin_begin: b,
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len,
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});
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b += len;
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}
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runs
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}
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|
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impl Scenario for FragmentedS {
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fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()> {
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// Allocate each thin fully, in runs between 1 and 16.
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let mut runs = Vec::new();
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for thin in 0..self.nr_thins {
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runs.append(&mut mk_runs(thin, self.thin_size, 1..17));
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}
|
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|
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// Shuffle
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runs.shuffle(&mut rand::thread_rng());
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|
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// map across the data
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let mut maps = Vec::new();
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let mut b = 0;
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for r in &runs {
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maps.push(MappedRun {
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thin_id: r.thin_id,
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thin_begin: r.thin_begin,
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data_begin: b,
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len: r.len,
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});
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b += r.len;
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}
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|
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// drop half the mappings, which leaves us free runs
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let mut dropped = Vec::new();
|
|
for i in 0..maps.len() {
|
|
if i % 2 == 0 {
|
|
dropped.push(maps[i].clone());
|
|
}
|
|
}
|
|
|
|
// Unshuffle. This isn't strictly necc. but makes the xml
|
|
// more readable.
|
|
use std::cmp::Ordering;
|
|
maps.sort_by(|&l, &r| match l.thin_id.cmp(&r.thin_id) {
|
|
Ordering::Equal => l.thin_begin.cmp(&r.thin_begin),
|
|
o => o,
|
|
});
|
|
|
|
// write the xml
|
|
v.superblock_b(&common_sb(self.old_nr_data_blocks))?;
|
|
for thin in 0..self.nr_thins {
|
|
v.device_b(&xml::Device {
|
|
dev_id: thin,
|
|
mapped_blocks: self.thin_size,
|
|
transaction: 0,
|
|
creation_time: 0,
|
|
snap_time: 0,
|
|
})?;
|
|
|
|
for m in &dropped {
|
|
if m.thin_id != thin {
|
|
continue;
|
|
}
|
|
|
|
v.map(&xml::Map {
|
|
thin_begin: m.thin_begin,
|
|
data_begin: m.data_begin,
|
|
time: 0,
|
|
len: m.len,
|
|
})?;
|
|
}
|
|
|
|
v.device_e()?;
|
|
}
|
|
v.superblock_e()?;
|
|
Ok(())
|
|
}
|
|
|
|
fn get_new_nr_blocks(&self) -> u64 {
|
|
self.new_nr_data_blocks
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn shrink_fragmented_thin_1() -> Result<()> {
|
|
let mut s = FragmentedS::new(1, 2048);
|
|
test_shrink(&mut s)
|
|
}
|
|
|
|
#[test]
|
|
fn shrink_fragmented_thin_2() -> Result<()> {
|
|
let mut s = FragmentedS::new(2, 2048);
|
|
test_shrink(&mut s)
|
|
}
|
|
|
|
#[test]
|
|
fn shrink_fragmented_thin_8() -> Result<()> {
|
|
let mut s = FragmentedS::new(2, 2048);
|
|
test_shrink(&mut s)
|
|
}
|
|
|
|
#[test]
|
|
fn shrink_fragmented_thin_64() -> Result<()> {
|
|
let mut s = FragmentedS::new(2, 2048);
|
|
test_shrink(&mut s)
|
|
}
|
|
|
|
//------------------------------------
|
|
|
|
struct Allocator {
|
|
runs: VecDeque<Range<u64>>,
|
|
}
|
|
|
|
impl Allocator {
|
|
fn new_shuffled(total_len: u64, run_len: Range<u64>) -> Allocator {
|
|
let mut runs = Vec::new();
|
|
|
|
let mut b = 0u64;
|
|
while b < total_len {
|
|
let len = u64::min(
|
|
total_len - b,
|
|
thread_rng().gen_range(run_len.start, run_len.end),
|
|
);
|
|
runs.push(b..(b + len));
|
|
b += len;
|
|
}
|
|
|
|
runs.shuffle(&mut thread_rng());
|
|
let runs: VecDeque<Range<u64>> = runs.iter().map(|r| r.clone()).collect();
|
|
Allocator { runs }
|
|
}
|
|
|
|
fn is_empty(&self) -> bool {
|
|
self.runs.is_empty()
|
|
}
|
|
|
|
fn alloc(&mut self, len: u64) -> Result<Vec<Range<u64>>> {
|
|
let mut len = len;
|
|
let mut runs = Vec::new();
|
|
|
|
while len > 0 {
|
|
let r = self.runs.pop_front();
|
|
|
|
if r.is_none() {
|
|
return Err(anyhow!("could not allocate; out of space"));
|
|
}
|
|
|
|
let mut r = r.unwrap();
|
|
let rlen = r.end - r.start;
|
|
if len < rlen {
|
|
runs.push(r.start..(r.start + len));
|
|
|
|
// We need to push something back.
|
|
self.runs.push_front((r.start + len)..r.end);
|
|
len = 0;
|
|
} else {
|
|
runs.push(r.start..r.end);
|
|
len -= rlen;
|
|
}
|
|
}
|
|
|
|
Ok(runs)
|
|
}
|
|
}
|
|
|
|
// Having explicitly unmapped regions makes it easier to
|
|
// apply snapshots.
|
|
#[derive(Clone)]
|
|
enum Run {
|
|
Mapped { data_begin: u64, len: u64 },
|
|
UnMapped { len: u64 },
|
|
}
|
|
|
|
impl Run {
|
|
fn len(&self) -> u64 {
|
|
match self {
|
|
Run::Mapped {
|
|
data_begin: _data_begin,
|
|
len,
|
|
} => *len,
|
|
Run::UnMapped { len } => *len,
|
|
}
|
|
}
|
|
|
|
fn split(&self, n: u64) -> (Option<Run>, Option<Run>) {
|
|
if n == 0 {
|
|
return (None, Some(self.clone()));
|
|
} else {
|
|
if self.len() <= n {
|
|
return (Some(self.clone()), None);
|
|
} else {
|
|
match self {
|
|
Run::Mapped { data_begin, len } => (
|
|
Some(Run::Mapped {
|
|
data_begin: *data_begin,
|
|
len: n,
|
|
}),
|
|
Some(Run::Mapped {
|
|
data_begin: data_begin + n,
|
|
len: len - n,
|
|
}),
|
|
),
|
|
Run::UnMapped { len } => (
|
|
Some(Run::UnMapped { len: n }),
|
|
Some(Run::UnMapped { len: len - n }),
|
|
),
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#[derive(Clone)]
|
|
struct ThinDev {
|
|
thin_id: u32,
|
|
dev_size: u64,
|
|
runs: Vec<Run>,
|
|
}
|
|
|
|
impl ThinDev {
|
|
fn emit(&self, v: &mut dyn xml::MetadataVisitor) -> Result<()> {
|
|
v.device_b(&xml::Device {
|
|
dev_id: self.thin_id,
|
|
mapped_blocks: self.dev_size,
|
|
transaction: 0,
|
|
creation_time: 0,
|
|
snap_time: 0,
|
|
})?;
|
|
|
|
let mut b = 0;
|
|
for r in &self.runs {
|
|
match r {
|
|
Run::Mapped { data_begin, len } => {
|
|
v.map(&xml::Map {
|
|
thin_begin: b,
|
|
data_begin: *data_begin,
|
|
time: 0,
|
|
len: *len,
|
|
})?;
|
|
b += len;
|
|
}
|
|
Run::UnMapped { len } => {
|
|
b += len;
|
|
}
|
|
}
|
|
}
|
|
|
|
v.device_e()?;
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
#[derive(Clone)]
|
|
enum SnapRunType {
|
|
Same,
|
|
Diff,
|
|
Hole,
|
|
}
|
|
|
|
#[derive(Clone)]
|
|
struct SnapRun(SnapRunType, u64);
|
|
|
|
fn mk_origin(thin_id: u32, total_len: u64, allocator: &mut Allocator) -> Result<ThinDev> {
|
|
let mut runs = Vec::new();
|
|
let mut b = 0;
|
|
while b < total_len {
|
|
let len = u64::min(thread_rng().gen_range(16, 64), total_len - b);
|
|
match thread_rng().gen_range(0, 2) {
|
|
0 => {
|
|
for data in allocator.alloc(len)? {
|
|
assert!(data.end >= data.start);
|
|
runs.push(Run::Mapped {
|
|
data_begin: data.start,
|
|
len: data.end - data.start,
|
|
});
|
|
}
|
|
}
|
|
1 => {
|
|
runs.push(Run::UnMapped { len });
|
|
}
|
|
_ => {
|
|
return Err(anyhow!("bad value returned from rng"));
|
|
}
|
|
};
|
|
|
|
b += len;
|
|
}
|
|
|
|
Ok(ThinDev {
|
|
thin_id,
|
|
dev_size: total_len,
|
|
runs,
|
|
})
|
|
}
|
|
|
|
fn mk_snap_mapping(
|
|
total_len: u64,
|
|
run_len: Range<u64>,
|
|
same_percent: usize,
|
|
diff_percent: usize,
|
|
) -> Vec<SnapRun> {
|
|
let mut runs = Vec::new();
|
|
|
|
let mut b = 0u64;
|
|
while b < total_len {
|
|
let len = u64::min(
|
|
total_len - b,
|
|
thread_rng().gen_range(run_len.start, run_len.end),
|
|
);
|
|
|
|
let n = thread_rng().gen_range(0, 100);
|
|
|
|
if n < same_percent {
|
|
runs.push(SnapRun(SnapRunType::Same, len));
|
|
} else if n < diff_percent {
|
|
runs.push(SnapRun(SnapRunType::Diff, len));
|
|
} else {
|
|
runs.push(SnapRun(SnapRunType::Hole, len));
|
|
}
|
|
|
|
b += len;
|
|
}
|
|
|
|
runs
|
|
}
|
|
|
|
fn split_runs(mut n: u64, runs: &Vec<Run>) -> (Vec<Run>, Vec<Run>) {
|
|
let mut before = Vec::new();
|
|
let mut after = Vec::new();
|
|
|
|
for r in runs {
|
|
match r.split(n) {
|
|
(Some(lhs), None) => {
|
|
before.push(lhs);
|
|
}
|
|
(Some(lhs), Some(rhs)) => {
|
|
before.push(lhs);
|
|
after.push(rhs);
|
|
}
|
|
(None, Some(rhs)) => {
|
|
after.push(rhs);
|
|
}
|
|
(None, None) => {}
|
|
}
|
|
n -= r.len();
|
|
}
|
|
|
|
(before, after)
|
|
}
|
|
|
|
fn apply_snap_runs(
|
|
origin: &Vec<Run>,
|
|
snap: &Vec<SnapRun>,
|
|
allocator: &mut Allocator,
|
|
) -> Result<Vec<Run>> {
|
|
let mut origin = origin.clone();
|
|
let mut runs = Vec::new();
|
|
|
|
for SnapRun(st, slen) in snap {
|
|
let (os, rest) = split_runs(*slen, &origin);
|
|
match st {
|
|
SnapRunType::Same => {
|
|
for o in os {
|
|
runs.push(o);
|
|
}
|
|
}
|
|
SnapRunType::Diff => {
|
|
for data in allocator.alloc(*slen)? {
|
|
runs.push(Run::Mapped {
|
|
data_begin: data.start,
|
|
len: data.end - data.start,
|
|
});
|
|
}
|
|
}
|
|
SnapRunType::Hole => {
|
|
runs.push(Run::UnMapped { len: *slen });
|
|
}
|
|
}
|
|
|
|
origin = rest;
|
|
}
|
|
|
|
Ok(runs)
|
|
}
|
|
|
|
// Snapshots share mappings, not neccessarily the entire ranges.
|
|
struct SnapS {
|
|
len: u64,
|
|
nr_snaps: u32,
|
|
|
|
// Snaps will differ from the origin by this percentage
|
|
percent_change: usize,
|
|
old_nr_data_blocks: u64,
|
|
new_nr_data_blocks: u64,
|
|
}
|
|
|
|
impl SnapS {
|
|
fn new(len: u64, nr_snaps: u32, percent_change: usize) -> Self {
|
|
let delta = len * (nr_snaps as u64) * (percent_change as u64) / 100;
|
|
let old_nr_data_blocks = len + 3 * delta;
|
|
let new_nr_data_blocks = len + 2 * delta;
|
|
|
|
SnapS {
|
|
len,
|
|
nr_snaps,
|
|
percent_change,
|
|
old_nr_data_blocks,
|
|
new_nr_data_blocks,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl Scenario for SnapS {
|
|
fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()> {
|
|
let mut allocator = Allocator::new_shuffled(self.old_nr_data_blocks, 64..512);
|
|
let origin = mk_origin(0, self.len, &mut allocator)?;
|
|
|
|
v.superblock_b(&common_sb(self.old_nr_data_blocks))?;
|
|
origin.emit(v)?;
|
|
v.superblock_e()?;
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn get_new_nr_blocks(&self) -> u64 {
|
|
self.new_nr_data_blocks
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn shrink_identical_snap() -> Result<()> {
|
|
let mut s = SnapS::new(1024, 1, 0);
|
|
test_shrink(&mut s)
|
|
}
|
|
|
|
//------------------------------------
|