proxmox-backup/pbs-datastore/src/fixed_index.rs

473 lines
13 KiB
Rust

use std::fs::File;
use std::io::Write;
use std::io::{Seek, SeekFrom};
use std::os::unix::io::AsRawFd;
use std::path::{Path, PathBuf};
use std::sync::Arc;
use anyhow::{bail, format_err, Error};
use proxmox_io::ReadExt;
use proxmox_sys::process_locker::ProcessLockSharedGuard;
use proxmox_uuid::Uuid;
use crate::chunk_stat::ChunkStat;
use crate::chunk_store::ChunkStore;
use crate::data_blob::ChunkInfo;
use crate::file_formats;
use crate::index::{ChunkReadInfo, IndexFile};
/// Header format definition for fixed index files (`.fidx`)
#[repr(C)]
pub struct FixedIndexHeader {
pub magic: [u8; 8],
pub uuid: [u8; 16],
pub ctime: i64,
/// Sha256 over the index ``SHA256(digest1||digest2||...)``
pub index_csum: [u8; 32],
pub size: u64,
pub chunk_size: u64,
reserved: [u8; 4016], // overall size is one page (4096 bytes)
}
proxmox_lang::static_assert_size!(FixedIndexHeader, 4096);
// split image into fixed size chunks
pub struct FixedIndexReader {
_file: File,
pub chunk_size: usize,
pub size: u64,
index_length: usize,
index: *mut u8,
pub uuid: [u8; 16],
pub ctime: i64,
pub index_csum: [u8; 32],
}
// `index` is mmap()ed which cannot be thread-local so should be sendable
unsafe impl Send for FixedIndexReader {}
unsafe impl Sync for FixedIndexReader {}
impl Drop for FixedIndexReader {
fn drop(&mut self) {
if let Err(err) = self.unmap() {
eprintln!("Unable to unmap file - {}", err);
}
}
}
impl FixedIndexReader {
pub fn open(path: &Path) -> Result<Self, Error> {
File::open(path)
.map_err(Error::from)
.and_then(Self::new)
.map_err(|err| format_err!("Unable to open fixed index {:?} - {}", path, err))
}
pub fn new(mut file: std::fs::File) -> Result<Self, Error> {
file.seek(SeekFrom::Start(0))?;
let header_size = std::mem::size_of::<FixedIndexHeader>();
let stat = match nix::sys::stat::fstat(file.as_raw_fd()) {
Ok(stat) => stat,
Err(err) => bail!("fstat failed - {}", err),
};
let size = stat.st_size as usize;
if size < header_size {
bail!("index too small ({})", stat.st_size);
}
let header: Box<FixedIndexHeader> = unsafe { file.read_host_value_boxed()? };
if header.magic != file_formats::FIXED_SIZED_CHUNK_INDEX_1_0 {
bail!("got unknown magic number");
}
let size = u64::from_le(header.size);
let ctime = i64::from_le(header.ctime);
let chunk_size = u64::from_le(header.chunk_size);
let index_length = ((size + chunk_size - 1) / chunk_size) as usize;
let index_size = index_length * 32;
let expected_index_size = (stat.st_size as usize) - header_size;
if index_size != expected_index_size {
bail!(
"got unexpected file size ({} != {})",
index_size,
expected_index_size
);
}
let data = unsafe {
nix::sys::mman::mmap(
std::ptr::null_mut(),
index_size,
nix::sys::mman::ProtFlags::PROT_READ,
nix::sys::mman::MapFlags::MAP_PRIVATE,
file.as_raw_fd(),
header_size as i64,
)
}? as *mut u8;
Ok(Self {
_file: file,
chunk_size: chunk_size as usize,
size,
index_length,
index: data,
ctime,
uuid: header.uuid,
index_csum: header.index_csum,
})
}
fn unmap(&mut self) -> Result<(), Error> {
if self.index.is_null() {
return Ok(());
}
let index_size = self.index_length * 32;
if let Err(err) =
unsafe { nix::sys::mman::munmap(self.index as *mut std::ffi::c_void, index_size) }
{
bail!("unmap file failed - {}", err);
}
self.index = std::ptr::null_mut();
Ok(())
}
pub fn print_info(&self) {
println!("Size: {}", self.size);
println!("ChunkSize: {}", self.chunk_size);
let mut ctime_str = self.ctime.to_string();
if let Ok(s) = proxmox_time::strftime_local("%c", self.ctime) {
ctime_str = s;
}
println!("CTime: {}", ctime_str);
println!("UUID: {:?}", self.uuid);
}
}
impl IndexFile for FixedIndexReader {
fn index_count(&self) -> usize {
self.index_length
}
fn index_digest(&self, pos: usize) -> Option<&[u8; 32]> {
if pos >= self.index_length {
None
} else {
Some(unsafe { &*(self.index.add(pos * 32) as *const [u8; 32]) })
}
}
fn index_bytes(&self) -> u64 {
self.size
}
fn chunk_info(&self, pos: usize) -> Option<ChunkReadInfo> {
if pos >= self.index_length {
return None;
}
let start = (pos * self.chunk_size) as u64;
let mut end = start + self.chunk_size as u64;
if end > self.size {
end = self.size;
}
let digest = self.index_digest(pos).unwrap();
Some(ChunkReadInfo {
range: start..end,
digest: *digest,
})
}
fn index_ctime(&self) -> i64 {
self.ctime
}
fn index_size(&self) -> usize {
self.size as usize
}
fn compute_csum(&self) -> ([u8; 32], u64) {
let mut csum = openssl::sha::Sha256::new();
let mut chunk_end = 0;
for pos in 0..self.index_count() {
let info = self.chunk_info(pos).unwrap();
chunk_end = info.range.end;
csum.update(&info.digest);
}
let csum = csum.finish();
(csum, chunk_end)
}
fn chunk_from_offset(&self, offset: u64) -> Option<(usize, u64)> {
if offset >= self.size {
return None;
}
Some((
(offset / self.chunk_size as u64) as usize,
offset & (self.chunk_size - 1) as u64, // fast modulo, valid for 2^x chunk_size
))
}
}
pub struct FixedIndexWriter {
store: Arc<ChunkStore>,
file: File,
_lock: ProcessLockSharedGuard,
filename: PathBuf,
tmp_filename: PathBuf,
chunk_size: usize,
size: usize,
index_length: usize,
index: *mut u8,
pub uuid: [u8; 16],
pub ctime: i64,
}
// `index` is mmap()ed which cannot be thread-local so should be sendable
unsafe impl Send for FixedIndexWriter {}
impl Drop for FixedIndexWriter {
fn drop(&mut self) {
let _ = std::fs::remove_file(&self.tmp_filename); // ignore errors
if let Err(err) = self.unmap() {
eprintln!("Unable to unmap file {:?} - {}", self.tmp_filename, err);
}
}
}
impl FixedIndexWriter {
#[allow(clippy::cast_ptr_alignment)]
pub fn create(
store: Arc<ChunkStore>,
path: &Path,
size: usize,
chunk_size: usize,
) -> Result<Self, Error> {
let shared_lock = store.try_shared_lock()?;
let full_path = store.relative_path(path);
let mut tmp_path = full_path.clone();
tmp_path.set_extension("tmp_fidx");
let mut file = std::fs::OpenOptions::new()
.create(true)
.truncate(true)
.read(true)
.write(true)
.open(&tmp_path)?;
let header_size = std::mem::size_of::<FixedIndexHeader>();
// todo: use static assertion when available in rust
if header_size != 4096 {
panic!("got unexpected header size");
}
let ctime = proxmox_time::epoch_i64();
let uuid = Uuid::generate();
let buffer = vec![0u8; header_size];
let header = unsafe { &mut *(buffer.as_ptr() as *mut FixedIndexHeader) };
header.magic = file_formats::FIXED_SIZED_CHUNK_INDEX_1_0;
header.ctime = i64::to_le(ctime);
header.size = u64::to_le(size as u64);
header.chunk_size = u64::to_le(chunk_size as u64);
header.uuid = *uuid.as_bytes();
header.index_csum = [0u8; 32];
file.write_all(&buffer)?;
let index_length = (size + chunk_size - 1) / chunk_size;
let index_size = index_length * 32;
nix::unistd::ftruncate(file.as_raw_fd(), (header_size + index_size) as i64)?;
let data = unsafe {
nix::sys::mman::mmap(
std::ptr::null_mut(),
index_size,
nix::sys::mman::ProtFlags::PROT_READ | nix::sys::mman::ProtFlags::PROT_WRITE,
nix::sys::mman::MapFlags::MAP_SHARED,
file.as_raw_fd(),
header_size as i64,
)
}? as *mut u8;
Ok(Self {
store,
file,
_lock: shared_lock,
filename: full_path,
tmp_filename: tmp_path,
chunk_size,
size,
index_length,
index: data,
ctime,
uuid: *uuid.as_bytes(),
})
}
pub fn index_length(&self) -> usize {
self.index_length
}
fn unmap(&mut self) -> Result<(), Error> {
if self.index.is_null() {
return Ok(());
}
let index_size = self.index_length * 32;
if let Err(err) =
unsafe { nix::sys::mman::munmap(self.index as *mut std::ffi::c_void, index_size) }
{
bail!("unmap file {:?} failed - {}", self.tmp_filename, err);
}
self.index = std::ptr::null_mut();
Ok(())
}
pub fn close(&mut self) -> Result<[u8; 32], Error> {
if self.index.is_null() {
bail!("cannot close already closed index file.");
}
let index_size = self.index_length * 32;
let data = unsafe { std::slice::from_raw_parts(self.index, index_size) };
let index_csum = openssl::sha::sha256(data);
self.unmap()?;
let csum_offset = proxmox_lang::offsetof!(FixedIndexHeader, index_csum);
self.file.seek(SeekFrom::Start(csum_offset as u64))?;
self.file.write_all(&index_csum)?;
self.file.flush()?;
if let Err(err) = std::fs::rename(&self.tmp_filename, &self.filename) {
bail!("Atomic rename file {:?} failed - {}", self.filename, err);
}
Ok(index_csum)
}
pub fn check_chunk_alignment(&self, offset: usize, chunk_len: usize) -> Result<usize, Error> {
if offset < chunk_len {
bail!("got chunk with small offset ({} < {}", offset, chunk_len);
}
let pos = offset - chunk_len;
if offset > self.size {
bail!("chunk data exceeds size ({} >= {})", offset, self.size);
}
// last chunk can be smaller
if ((offset != self.size) && (chunk_len != self.chunk_size))
|| (chunk_len > self.chunk_size)
|| (chunk_len == 0)
{
bail!(
"chunk with unexpected length ({} != {}",
chunk_len,
self.chunk_size
);
}
if pos & (self.chunk_size - 1) != 0 {
bail!("got unaligned chunk (pos = {})", pos);
}
Ok(pos / self.chunk_size)
}
// Note: We want to add data out of order, so do not assume any order here.
pub fn add_chunk(&mut self, chunk_info: &ChunkInfo, stat: &mut ChunkStat) -> Result<(), Error> {
let chunk_len = chunk_info.chunk_len as usize;
let offset = chunk_info.offset as usize; // end of chunk
let idx = self.check_chunk_alignment(offset, chunk_len)?;
let (is_duplicate, compressed_size) = self
.store
.insert_chunk(&chunk_info.chunk, &chunk_info.digest)?;
stat.chunk_count += 1;
stat.compressed_size += compressed_size;
let digest = &chunk_info.digest;
println!(
"ADD CHUNK {} {} {}% {} {}",
idx,
chunk_len,
(compressed_size * 100) / (chunk_len as u64),
is_duplicate,
hex::encode(digest)
);
if is_duplicate {
stat.duplicate_chunks += 1;
} else {
stat.disk_size += compressed_size;
}
self.add_digest(idx, digest)
}
pub fn add_digest(&mut self, index: usize, digest: &[u8; 32]) -> Result<(), Error> {
if index >= self.index_length {
bail!(
"add digest failed - index out of range ({} >= {})",
index,
self.index_length
);
}
if self.index.is_null() {
bail!("cannot write to closed index file.");
}
let index_pos = index * 32;
unsafe {
let dst = self.index.add(index_pos);
dst.copy_from_nonoverlapping(digest.as_ptr(), 32);
}
Ok(())
}
pub fn clone_data_from(&mut self, reader: &FixedIndexReader) -> Result<(), Error> {
if self.index_length != reader.index_count() {
bail!("clone_data_from failed - index sizes not equal");
}
for i in 0..self.index_length {
self.add_digest(i, reader.index_digest(i).unwrap())?;
}
Ok(())
}
}