proxmox-backup/src/backup/dynamic_index.rs

664 lines
19 KiB
Rust

use std::convert::TryInto;
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 failure::*;
use proxmox::tools::io::ReadExt;
use proxmox::tools::uuid::Uuid;
use proxmox::tools::vec;
use super::chunk_stat::ChunkStat;
use super::chunk_store::ChunkStore;
use super::read_chunk::ReadChunk;
use super::Chunker;
use super::IndexFile;
use super::{DataBlob, DataChunkBuilder};
use crate::tools;
/// Header format definition for dynamic index files (`.dixd`)
#[repr(C)]
pub struct DynamicIndexHeader {
pub magic: [u8; 8],
pub uuid: [u8; 16],
pub ctime: u64,
/// 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::tools::static_assert_size!(DynamicIndexHeader, 4096);
// TODO: Once non-Copy unions are stabilized, use:
// union DynamicIndexHeader {
// reserved: [u8; 4096],
// pub data: DynamicIndexHeaderData,
// }
pub struct DynamicIndexReader {
_file: File,
pub size: usize,
index: *const u8,
index_entries: usize,
pub uuid: [u8; 16],
pub ctime: u64,
pub index_csum: [u8; 32],
}
// `index` is mmap()ed which cannot be thread-local so should be sendable
// FIXME: Introduce an mmap wrapper type for this?
unsafe impl Send for DynamicIndexReader {}
unsafe impl Sync for DynamicIndexReader {}
impl Drop for DynamicIndexReader {
fn drop(&mut self) {
if let Err(err) = self.unmap() {
eprintln!("Unable to unmap dynamic index - {}", err);
}
}
}
impl DynamicIndexReader {
pub fn open(path: &Path) -> Result<Self, Error> {
File::open(path)
.map_err(Error::from)
.and_then(|file| Self::new(file))
.map_err(|err| format_err!("Unable to open dynamic index {:?} - {}", path, err))
}
pub fn new(mut file: std::fs::File) -> Result<Self, Error> {
if let Err(err) =
nix::fcntl::flock(file.as_raw_fd(), nix::fcntl::FlockArg::LockSharedNonblock)
{
bail!("unable to get shared lock - {}", err);
}
file.seek(SeekFrom::Start(0))?;
let header_size = std::mem::size_of::<DynamicIndexHeader>();
let header: Box<DynamicIndexHeader> = unsafe { file.read_host_value_boxed()? };
if header.magic != super::DYNAMIC_SIZED_CHUNK_INDEX_1_0 {
bail!("got unknown magic number");
}
let ctime = u64::from_le(header.ctime);
let rawfd = file.as_raw_fd();
let stat = nix::sys::stat::fstat(rawfd)?;
let size = stat.st_size as usize;
let index_size = size - header_size;
if (index_size % 40) != 0 {
bail!("got unexpected file 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,
rawfd,
header_size as i64,
)
}? as *const u8;
Ok(Self {
_file: file,
size,
index: data,
index_entries: index_size / 40,
ctime,
uuid: header.uuid,
index_csum: header.index_csum,
})
}
fn unmap(&mut self) -> Result<(), Error> {
if self.index == std::ptr::null_mut() {
return Ok(());
}
if let Err(err) = unsafe {
nix::sys::mman::munmap(self.index as *mut std::ffi::c_void, self.index_entries * 40)
} {
bail!("unmap dynamic index failed - {}", err);
}
self.index = std::ptr::null_mut();
Ok(())
}
#[allow(clippy::cast_ptr_alignment)]
pub fn chunk_info(&self, pos: usize) -> Result<(u64, u64, [u8; 32]), Error> {
if pos >= self.index_entries {
bail!("chunk index out of range");
}
let start = if pos == 0 {
0
} else {
unsafe { *(self.index.add((pos - 1) * 40) as *const u64) }
};
let end = unsafe { *(self.index.add(pos * 40) as *const u64) };
let mut digest = std::mem::MaybeUninit::<[u8; 32]>::uninit();
unsafe {
std::ptr::copy_nonoverlapping(
self.index.add(pos * 40 + 8),
(*digest.as_mut_ptr()).as_mut_ptr(),
32,
);
}
Ok((start, end, unsafe { digest.assume_init() }))
}
#[inline]
#[allow(clippy::cast_ptr_alignment)]
fn chunk_end(&self, pos: usize) -> u64 {
if pos >= self.index_entries {
panic!("chunk index out of range");
}
unsafe { *(self.index.add(pos * 40) as *const u64) }
}
#[inline]
fn chunk_digest(&self, pos: usize) -> &[u8; 32] {
if pos >= self.index_entries {
panic!("chunk index out of range");
}
let slice = unsafe { std::slice::from_raw_parts(self.index.add(pos * 40 + 8), 32) };
slice.try_into().unwrap()
}
/// Compute checksum and data size
pub 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_entries {
chunk_end = self.chunk_end(pos);
let digest = self.chunk_digest(pos);
csum.update(&chunk_end.to_le_bytes());
csum.update(digest);
}
let csum = csum.finish();
(csum, chunk_end)
}
/*
pub fn dump_pxar(&self, mut writer: Box<dyn Write>) -> Result<(), Error> {
for pos in 0..self.index_entries {
let _end = self.chunk_end(pos);
let digest = self.chunk_digest(pos);
//println!("Dump {:08x}", end );
let chunk = self.store.read_chunk(digest)?;
// fimxe: handle encrypted chunks
let data = chunk.decode(None)?;
writer.write_all(&data)?;
}
Ok(())
}
*/
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_entries
}
fn index_digest(&self, pos: usize) -> Option<&[u8; 32]> {
if pos >= self.index_entries {
None
} else {
Some(unsafe { std::mem::transmute(self.chunk_digest(pos).as_ptr()) })
}
}
fn index_bytes(&self) -> u64 {
if self.index_entries == 0 {
0
} else {
self.chunk_end((self.index_entries - 1) as usize)
}
}
}
pub struct BufferedDynamicReader<S> {
store: S,
index: DynamicIndexReader,
archive_size: u64,
read_buffer: Vec<u8>,
buffered_chunk_idx: usize,
buffered_chunk_start: u64,
read_offset: u64,
}
impl<S: ReadChunk> BufferedDynamicReader<S> {
pub fn new(index: DynamicIndexReader, store: S) -> Self {
let archive_size = index.chunk_end(index.index_entries - 1);
Self {
store,
index,
archive_size,
read_buffer: Vec::with_capacity(1024 * 1024),
buffered_chunk_idx: 0,
buffered_chunk_start: 0,
read_offset: 0,
}
}
pub fn archive_size(&self) -> u64 {
self.archive_size
}
fn buffer_chunk(&mut self, idx: usize) -> Result<(), Error> {
let index = &self.index;
let (start, end, digest) = index.chunk_info(idx)?;
// fixme: avoid copy
let data = self.store.read_chunk(&digest)?;
if (end - start) != data.len() as u64 {
bail!(
"read chunk with wrong size ({} != {}",
(end - start),
data.len()
);
}
self.read_buffer.clear();
self.read_buffer.extend_from_slice(&data);
self.buffered_chunk_idx = idx;
self.buffered_chunk_start = start as u64;
//println!("BUFFER {} {}", self.buffered_chunk_start, end);
Ok(())
}
}
impl<S: ReadChunk> crate::tools::BufferedRead for BufferedDynamicReader<S> {
fn buffered_read(&mut self, offset: u64) -> Result<&[u8], Error> {
if offset == self.archive_size {
return Ok(&self.read_buffer[0..0]);
}
let buffer_len = self.read_buffer.len();
let index = &self.index;
// optimization for sequential read
if buffer_len > 0
&& ((self.buffered_chunk_idx + 1) < index.index_entries)
&& (offset >= (self.buffered_chunk_start + (self.read_buffer.len() as u64)))
{
let next_idx = self.buffered_chunk_idx + 1;
let next_end = index.chunk_end(next_idx);
if offset < next_end {
self.buffer_chunk(next_idx)?;
let buffer_offset = (offset - self.buffered_chunk_start) as usize;
return Ok(&self.read_buffer[buffer_offset..]);
}
}
if (buffer_len == 0)
|| (offset < self.buffered_chunk_start)
|| (offset >= (self.buffered_chunk_start + (self.read_buffer.len() as u64)))
{
let end_idx = index.index_entries - 1;
let end = index.chunk_end(end_idx);
let idx = index.binary_search(0, 0, end_idx, end, offset)?;
self.buffer_chunk(idx)?;
}
let buffer_offset = (offset - self.buffered_chunk_start) as usize;
Ok(&self.read_buffer[buffer_offset..])
}
}
impl<S: ReadChunk> std::io::Read for BufferedDynamicReader<S> {
fn read(&mut self, buf: &mut [u8]) -> Result<usize, std::io::Error> {
use crate::tools::BufferedRead;
use std::io::{Error, ErrorKind};
let data = match self.buffered_read(self.read_offset) {
Ok(v) => v,
Err(err) => return Err(Error::new(ErrorKind::Other, err.to_string())),
};
let n = if data.len() > buf.len() {
buf.len()
} else {
data.len()
};
unsafe {
std::ptr::copy_nonoverlapping(data.as_ptr(), buf.as_mut_ptr(), n);
}
self.read_offset += n as u64;
Ok(n)
}
}
impl<S: ReadChunk> std::io::Seek for BufferedDynamicReader<S> {
fn seek(&mut self, pos: SeekFrom) -> Result<u64, std::io::Error> {
let new_offset = match pos {
SeekFrom::Start(start_offset) => start_offset as i64,
SeekFrom::End(end_offset) => (self.archive_size as i64) + end_offset,
SeekFrom::Current(offset) => (self.read_offset as i64) + offset,
};
use std::io::{Error, ErrorKind};
if (new_offset < 0) || (new_offset > (self.archive_size as i64)) {
return Err(Error::new(
ErrorKind::Other,
format!(
"seek is out of range {} ([0..{}])",
new_offset, self.archive_size
),
));
}
self.read_offset = new_offset as u64;
Ok(self.read_offset)
}
}
/// Create dynamic index files (`.dixd`)
pub struct DynamicIndexWriter {
store: Arc<ChunkStore>,
_lock: tools::ProcessLockSharedGuard,
writer: BufWriter<File>,
closed: bool,
filename: PathBuf,
tmp_filename: PathBuf,
csum: Option<openssl::sha::Sha256>,
pub uuid: [u8; 16],
pub ctime: u64,
}
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 header_size = std::mem::size_of::<DynamicIndexHeader>();
// todo: use static assertion when available in rust
if header_size != 4096 {
panic!("got unexpected header size");
}
let ctime = std::time::SystemTime::now()
.duration_since(std::time::SystemTime::UNIX_EPOCH)?
.as_secs();
let uuid = Uuid::generate();
let mut buffer = vec::zeroed(header_size);
let header = crate::tools::map_struct_mut::<DynamicIndexHeader>(&mut buffer)?;
header.magic = super::DYNAMIC_SIZED_CHUNK_INDEX_1_0;
header.ctime = u64::to_le(ctime);
header.uuid = *uuid.as_bytes();
header.index_csum = [0u8; 32];
writer.write_all(&buffer)?;
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::tools::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()",
))
}
}