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

509 lines
14 KiB
Rust

use std::fs::File;
use std::io::{BufWriter, Seek, SeekFrom, Write};
use std::os::unix::io::AsRawFd;
use std::path::{Path, PathBuf};
use std::sync::Arc;
use anyhow::{bail, format_err, Error};
use proxmox::tools::io::ReadExt;
use proxmox::tools::uuid::Uuid;
use proxmox::tools::mmap::Mmap;
use pbs_tools::process_locker::ProcessLockSharedGuard;
use crate::Chunker;
use crate::chunk_stat::ChunkStat;
use crate::chunk_store::ChunkStore;
use crate::data_blob::{DataBlob, DataChunkBuilder};
use crate::file_formats;
use crate::index::{IndexFile, ChunkReadInfo};
/// Header format definition for dynamic index files (`.dixd`)
#[repr(C)]
pub struct DynamicIndexHeader {
pub magic: [u8; 8],
pub uuid: [u8; 16],
pub ctime: i64,
/// Sha256 over the index ``SHA256(offset1||digest1||offset2||digest2||...)``
pub index_csum: [u8; 32],
reserved: [u8; 4032], // overall size is one page (4096 bytes)
}
proxmox::static_assert_size!(DynamicIndexHeader, 4096);
// TODO: Once non-Copy unions are stabilized, use:
// union DynamicIndexHeader {
// reserved: [u8; 4096],
// pub data: DynamicIndexHeaderData,
// }
impl DynamicIndexHeader {
/// Convenience method to allocate a zero-initialized header struct.
pub fn zeroed() -> Box<Self> {
unsafe {
Box::from_raw(std::alloc::alloc_zeroed(std::alloc::Layout::new::<Self>()) as *mut Self)
}
}
pub fn as_bytes(&self) -> &[u8] {
unsafe {
std::slice::from_raw_parts(
self as *const Self as *const u8,
std::mem::size_of::<Self>(),
)
}
}
}
#[derive(Clone, Debug)]
#[repr(C)]
pub struct DynamicEntry {
end_le: u64,
digest: [u8; 32],
}
impl DynamicEntry {
#[inline]
pub fn end(&self) -> u64 {
u64::from_le(self.end_le)
}
}
pub struct DynamicIndexReader {
_file: File,
pub size: usize,
index: Mmap<DynamicEntry>,
pub uuid: [u8; 16],
pub ctime: i64,
pub index_csum: [u8; 32],
}
impl DynamicIndexReader {
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 dynamic index {:?} - {}", path, err))
}
pub fn index(&self) -> &[DynamicEntry] {
&self.index
}
pub fn new(mut file: std::fs::File) -> Result<Self, Error> {
// FIXME: This is NOT OUR job! Check the callers of this method and remove this!
file.seek(SeekFrom::Start(0))?;
let header_size = std::mem::size_of::<DynamicIndexHeader>();
let rawfd = file.as_raw_fd();
let stat = match nix::sys::stat::fstat(rawfd) {
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<DynamicIndexHeader> = unsafe { file.read_host_value_boxed()? };
if header.magic != file_formats::DYNAMIC_SIZED_CHUNK_INDEX_1_0 {
bail!("got unknown magic number");
}
let ctime = proxmox::tools::time::epoch_i64();
let index_size = stat.st_size as usize - header_size;
let index_count = index_size / 40;
if index_count * 40 != index_size {
bail!("got unexpected file size");
}
let index = unsafe {
Mmap::map_fd(
rawfd,
header_size as u64,
index_count,
nix::sys::mman::ProtFlags::PROT_READ,
nix::sys::mman::MapFlags::MAP_PRIVATE,
)?
};
Ok(Self {
_file: file,
size,
index,
ctime,
uuid: header.uuid,
index_csum: header.index_csum,
})
}
#[inline]
#[allow(clippy::cast_ptr_alignment)]
pub fn chunk_end(&self, pos: usize) -> u64 {
if pos >= self.index.len() {
panic!("chunk index out of range");
}
self.index[pos].end()
}
#[inline]
fn chunk_digest(&self, pos: usize) -> &[u8; 32] {
if pos >= self.index.len() {
panic!("chunk index out of range");
}
&self.index[pos].digest
}
pub fn binary_search(
&self,
start_idx: usize,
start: u64,
end_idx: usize,
end: u64,
offset: u64,
) -> Result<usize, Error> {
if (offset >= end) || (offset < start) {
bail!("offset out of range");
}
if end_idx == start_idx {
return Ok(start_idx); // found
}
let middle_idx = (start_idx + end_idx) / 2;
let middle_end = self.chunk_end(middle_idx);
if offset < middle_end {
self.binary_search(start_idx, start, middle_idx, middle_end, offset)
} else {
self.binary_search(middle_idx + 1, middle_end, end_idx, end, offset)
}
}
}
impl IndexFile for DynamicIndexReader {
fn index_count(&self) -> usize {
self.index.len()
}
fn index_digest(&self, pos: usize) -> Option<&[u8; 32]> {
if pos >= self.index.len() {
None
} else {
Some(unsafe { &*(self.chunk_digest(pos).as_ptr() as *const [u8; 32]) })
}
}
fn index_bytes(&self) -> u64 {
if self.index.is_empty() {
0
} else {
self.chunk_end(self.index.len() - 1)
}
}
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(&chunk_end.to_le_bytes());
csum.update(&info.digest);
}
let csum = csum.finish();
(csum, chunk_end)
}
fn chunk_info(&self, pos: usize) -> Option<ChunkReadInfo> {
if pos >= self.index.len() {
return None;
}
let start = if pos == 0 { 0 } else { self.index[pos - 1].end() };
let end = self.index[pos].end();
Some(ChunkReadInfo {
range: start..end,
digest: self.index[pos].digest,
})
}
fn index_ctime(&self) -> i64 {
self.ctime
}
fn index_size(&self) -> usize {
self.size as usize
}
fn chunk_from_offset(&self, offset: u64) -> Option<(usize, u64)> {
let end_idx = self.index.len() - 1;
let end = self.chunk_end(end_idx);
let found_idx = self.binary_search(0, 0, end_idx, end, offset);
let found_idx = match found_idx {
Ok(i) => i,
Err(_) => return None
};
let found_start = if found_idx == 0 {
0
} else {
self.chunk_end(found_idx - 1)
};
Some((found_idx, offset - found_start))
}
}
/// Create dynamic index files (`.dixd`)
pub struct DynamicIndexWriter {
store: Arc<ChunkStore>,
_lock: ProcessLockSharedGuard,
writer: BufWriter<File>,
closed: bool,
filename: PathBuf,
tmp_filename: PathBuf,
csum: Option<openssl::sha::Sha256>,
pub uuid: [u8; 16],
pub ctime: i64,
}
impl Drop for DynamicIndexWriter {
fn drop(&mut self) {
let _ = std::fs::remove_file(&self.tmp_filename); // ignore errors
}
}
impl DynamicIndexWriter {
pub fn create(store: Arc<ChunkStore>, path: &Path) -> 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_didx");
let file = std::fs::OpenOptions::new()
.create(true)
.truncate(true)
.read(true)
.write(true)
.open(&tmp_path)?;
let mut writer = BufWriter::with_capacity(1024 * 1024, file);
let ctime = proxmox::tools::time::epoch_i64();
let uuid = Uuid::generate();
let mut header = DynamicIndexHeader::zeroed();
header.magic = file_formats::DYNAMIC_SIZED_CHUNK_INDEX_1_0;
header.ctime = i64::to_le(ctime);
header.uuid = *uuid.as_bytes();
// header.index_csum = [0u8; 32];
writer.write_all(header.as_bytes())?;
let csum = Some(openssl::sha::Sha256::new());
Ok(Self {
store,
_lock: shared_lock,
writer,
closed: false,
filename: full_path,
tmp_filename: tmp_path,
ctime,
uuid: *uuid.as_bytes(),
csum,
})
}
// fixme: use add_chunk instead?
pub fn insert_chunk(&self, chunk: &DataBlob, digest: &[u8; 32]) -> Result<(bool, u64), Error> {
self.store.insert_chunk(chunk, digest)
}
pub fn close(&mut self) -> Result<[u8; 32], Error> {
if self.closed {
bail!(
"cannot close already closed archive index file {:?}",
self.filename
);
}
self.closed = true;
self.writer.flush()?;
let csum_offset = proxmox::offsetof!(DynamicIndexHeader, index_csum);
self.writer.seek(SeekFrom::Start(csum_offset as u64))?;
let csum = self.csum.take().unwrap();
let index_csum = csum.finish();
self.writer.write_all(&index_csum)?;
self.writer.flush()?;
if let Err(err) = std::fs::rename(&self.tmp_filename, &self.filename) {
bail!("Atomic rename file {:?} failed - {}", self.filename, err);
}
Ok(index_csum)
}
// fixme: rename to add_digest
pub fn add_chunk(&mut self, offset: u64, digest: &[u8; 32]) -> Result<(), Error> {
if self.closed {
bail!(
"cannot write to closed dynamic index file {:?}",
self.filename
);
}
let offset_le: &[u8; 8] = unsafe { &std::mem::transmute::<u64, [u8; 8]>(offset.to_le()) };
if let Some(ref mut csum) = self.csum {
csum.update(offset_le);
csum.update(digest);
}
self.writer.write_all(offset_le)?;
self.writer.write_all(digest)?;
Ok(())
}
}
/// Writer which splits a binary stream into dynamic sized chunks
///
/// And store the resulting chunk list into the index file.
pub struct DynamicChunkWriter {
index: DynamicIndexWriter,
closed: bool,
chunker: Chunker,
stat: ChunkStat,
chunk_offset: usize,
last_chunk: usize,
chunk_buffer: Vec<u8>,
}
impl DynamicChunkWriter {
pub fn new(index: DynamicIndexWriter, chunk_size: usize) -> Self {
Self {
index,
closed: false,
chunker: Chunker::new(chunk_size),
stat: ChunkStat::new(0),
chunk_offset: 0,
last_chunk: 0,
chunk_buffer: Vec::with_capacity(chunk_size * 4),
}
}
pub fn stat(&self) -> &ChunkStat {
&self.stat
}
pub fn close(&mut self) -> Result<(), Error> {
if self.closed {
return Ok(());
}
self.closed = true;
self.write_chunk_buffer()?;
self.index.close()?;
self.stat.size = self.chunk_offset as u64;
// add size of index file
self.stat.size +=
(self.stat.chunk_count * 40 + std::mem::size_of::<DynamicIndexHeader>()) as u64;
Ok(())
}
fn write_chunk_buffer(&mut self) -> Result<(), Error> {
let chunk_size = self.chunk_buffer.len();
if chunk_size == 0 {
return Ok(());
}
let expected_chunk_size = self.chunk_offset - self.last_chunk;
if expected_chunk_size != self.chunk_buffer.len() {
bail!("wrong chunk size {} != {}", expected_chunk_size, chunk_size);
}
self.stat.chunk_count += 1;
self.last_chunk = self.chunk_offset;
let (chunk, digest) = DataChunkBuilder::new(&self.chunk_buffer)
.compress(true)
.build()?;
match self.index.insert_chunk(&chunk, &digest) {
Ok((is_duplicate, compressed_size)) => {
self.stat.compressed_size += compressed_size;
if is_duplicate {
self.stat.duplicate_chunks += 1;
} else {
self.stat.disk_size += compressed_size;
}
println!(
"ADD CHUNK {:016x} {} {}% {} {}",
self.chunk_offset,
chunk_size,
(compressed_size * 100) / (chunk_size as u64),
is_duplicate,
proxmox::tools::digest_to_hex(&digest)
);
self.index.add_chunk(self.chunk_offset as u64, &digest)?;
self.chunk_buffer.truncate(0);
Ok(())
}
Err(err) => {
self.chunk_buffer.truncate(0);
Err(err)
}
}
}
}
impl Write for DynamicChunkWriter {
fn write(&mut self, data: &[u8]) -> std::result::Result<usize, std::io::Error> {
let chunker = &mut self.chunker;
let pos = chunker.scan(data);
if pos > 0 {
self.chunk_buffer.extend_from_slice(&data[0..pos]);
self.chunk_offset += pos;
if let Err(err) = self.write_chunk_buffer() {
return Err(std::io::Error::new(
std::io::ErrorKind::Other,
err.to_string(),
));
}
Ok(pos)
} else {
self.chunk_offset += data.len();
self.chunk_buffer.extend_from_slice(data);
Ok(data.len())
}
}
fn flush(&mut self) -> std::result::Result<(), std::io::Error> {
Err(std::io::Error::new(
std::io::ErrorKind::Other,
"please use close() instead of flush()",
))
}
}