proxmox-backup/src/backup/chunk_store.rs

480 lines
15 KiB
Rust

use anyhow::{bail, format_err, Error};
use std::path::{Path, PathBuf};
use std::io::Write;
use std::sync::{Arc, Mutex};
use std::os::unix::io::AsRawFd;
use proxmox::tools::fs::{CreateOptions, create_path, create_dir};
use crate::tools;
use crate::api2::types::GarbageCollectionStatus;
use super::DataBlob;
use crate::task::TaskState;
/// File system based chunk store
pub struct ChunkStore {
name: String, // used for error reporting
pub (crate) base: PathBuf,
chunk_dir: PathBuf,
mutex: Mutex<()>,
locker: Arc<Mutex<tools::ProcessLocker>>,
}
// TODO: what about sysctl setting vm.vfs_cache_pressure (0 - 100) ?
pub fn verify_chunk_size(size: usize) -> Result<(), Error> {
static SIZES: [usize; 7] = [64*1024, 128*1024, 256*1024, 512*1024, 1024*1024, 2048*1024, 4096*1024];
if !SIZES.contains(&size) {
bail!("Got unsupported chunk size '{}'", size);
}
Ok(())
}
fn digest_to_prefix(digest: &[u8]) -> PathBuf {
let mut buf = Vec::<u8>::with_capacity(2+1+2+1);
const HEX_CHARS: &[u8; 16] = b"0123456789abcdef";
buf.push(HEX_CHARS[(digest[0] as usize) >> 4]);
buf.push(HEX_CHARS[(digest[0] as usize) &0xf]);
buf.push(HEX_CHARS[(digest[1] as usize) >> 4]);
buf.push(HEX_CHARS[(digest[1] as usize) & 0xf]);
buf.push(b'/');
let path = unsafe { String::from_utf8_unchecked(buf)};
path.into()
}
impl ChunkStore {
fn chunk_dir<P: AsRef<Path>>(path: P) -> PathBuf {
let mut chunk_dir: PathBuf = PathBuf::from(path.as_ref());
chunk_dir.push(".chunks");
chunk_dir
}
pub fn create<P>(name: &str, path: P, uid: nix::unistd::Uid, gid: nix::unistd::Gid) -> Result<Self, Error>
where
P: Into<PathBuf>,
{
let base: PathBuf = path.into();
if !base.is_absolute() {
bail!("expected absolute path - got {:?}", base);
}
let chunk_dir = Self::chunk_dir(&base);
let options = CreateOptions::new()
.owner(uid)
.group(gid);
let default_options = CreateOptions::new();
match create_path(&base, Some(default_options), Some(options.clone())) {
Err(err) => bail!("unable to create chunk store '{}' at {:?} - {}", name, base, err),
Ok(res) => if ! res { nix::unistd::chown(&base, Some(uid), Some(gid))? },
}
if let Err(err) = create_dir(&chunk_dir, options.clone()) {
bail!("unable to create chunk store '{}' subdir {:?} - {}", name, chunk_dir, err);
}
// create lock file with correct owner/group
let lockfile_path = Self::lockfile_path(&base);
proxmox::tools::fs::replace_file(lockfile_path, b"", options.clone())?;
// create 64*1024 subdirs
let mut last_percentage = 0;
for i in 0..64*1024 {
let mut l1path = chunk_dir.clone();
l1path.push(format!("{:04x}", i));
if let Err(err) = create_dir(&l1path, options.clone()) {
bail!("unable to create chunk store '{}' subdir {:?} - {}", name, l1path, err);
}
let percentage = (i*100)/(64*1024);
if percentage != last_percentage {
// eprintln!("ChunkStore::create {}%", percentage);
last_percentage = percentage;
}
}
Self::open(name, base)
}
fn lockfile_path<P: Into<PathBuf>>(base: P) -> PathBuf {
let mut lockfile_path: PathBuf = base.into();
lockfile_path.push(".lock");
lockfile_path
}
pub fn open<P: Into<PathBuf>>(name: &str, base: P) -> Result<Self, Error> {
let base: PathBuf = base.into();
if !base.is_absolute() {
bail!("expected absolute path - got {:?}", base);
}
let chunk_dir = Self::chunk_dir(&base);
if let Err(err) = std::fs::metadata(&chunk_dir) {
bail!("unable to open chunk store '{}' at {:?} - {}", name, chunk_dir, err);
}
let lockfile_path = Self::lockfile_path(&base);
let locker = tools::ProcessLocker::new(&lockfile_path)?;
Ok(ChunkStore {
name: name.to_owned(),
base,
chunk_dir,
locker,
mutex: Mutex::new(())
})
}
pub fn touch_chunk(&self, digest: &[u8; 32]) -> Result<(), Error> {
self.cond_touch_chunk(digest, true)?;
Ok(())
}
pub fn cond_touch_chunk(&self, digest: &[u8; 32], fail_if_not_exist: bool) -> Result<bool, Error> {
let (chunk_path, _digest_str) = self.chunk_path(digest);
self.cond_touch_path(&chunk_path, fail_if_not_exist)
}
pub fn cond_touch_path(&self, path: &Path, fail_if_not_exist: bool) -> Result<bool, Error> {
const UTIME_NOW: i64 = (1 << 30) - 1;
const UTIME_OMIT: i64 = (1 << 30) - 2;
let times: [libc::timespec; 2] = [
libc::timespec { tv_sec: 0, tv_nsec: UTIME_NOW },
libc::timespec { tv_sec: 0, tv_nsec: UTIME_OMIT }
];
use nix::NixPath;
let res = path.with_nix_path(|cstr| unsafe {
let tmp = libc::utimensat(-1, cstr.as_ptr(), &times[0], libc::AT_SYMLINK_NOFOLLOW);
nix::errno::Errno::result(tmp)
})?;
if let Err(err) = res {
if !fail_if_not_exist && err.as_errno() == Some(nix::errno::Errno::ENOENT) {
return Ok(false);
}
bail!("update atime failed for chunk/file {:?} - {}", path, err);
}
Ok(true)
}
pub fn get_chunk_iterator(
&self,
) -> Result<
impl Iterator<Item = (Result<tools::fs::ReadDirEntry, Error>, usize, bool)> + std::iter::FusedIterator,
Error
> {
use nix::dir::Dir;
use nix::fcntl::OFlag;
use nix::sys::stat::Mode;
let base_handle = Dir::open(&self.chunk_dir, OFlag::O_RDONLY, Mode::empty())
.map_err(|err| {
format_err!(
"unable to open store '{}' chunk dir {:?} - {}",
self.name,
self.chunk_dir,
err,
)
})?;
let mut done = false;
let mut inner: Option<tools::fs::ReadDir> = None;
let mut at = 0;
let mut percentage = 0;
Ok(std::iter::from_fn(move || {
if done {
return None;
}
loop {
if let Some(ref mut inner) = inner {
match inner.next() {
Some(Ok(entry)) => {
// skip files if they're not a hash
let bytes = entry.file_name().to_bytes();
if bytes.len() != 64 && bytes.len() != 64 + ".0.bad".len() {
continue;
}
if !bytes.iter().take(64).all(u8::is_ascii_hexdigit) {
continue;
}
let bad = bytes.ends_with(b".bad");
return Some((Ok(entry), percentage, bad));
}
Some(Err(err)) => {
// stop after first error
done = true;
// and pass the error through:
return Some((Err(err), percentage, false));
}
None => (), // open next directory
}
}
inner = None;
if at == 0x10000 {
done = true;
return None;
}
let subdir: &str = &format!("{:04x}", at);
percentage = (at * 100) / 0x10000;
at += 1;
match tools::fs::read_subdir(base_handle.as_raw_fd(), subdir) {
Ok(dir) => {
inner = Some(dir);
// start reading:
continue;
}
Err(ref err) if err.as_errno() == Some(nix::errno::Errno::ENOENT) => {
// non-existing directories are okay, just keep going:
continue;
}
Err(err) => {
// other errors are fatal, so end our iteration
done = true;
// and pass the error through:
return Some((Err(format_err!("unable to read subdir '{}' - {}", subdir, err)), percentage, false));
}
}
}
}).fuse())
}
pub fn oldest_writer(&self) -> Option<i64> {
tools::ProcessLocker::oldest_shared_lock(self.locker.clone())
}
pub fn sweep_unused_chunks(
&self,
oldest_writer: i64,
phase1_start_time: i64,
status: &mut GarbageCollectionStatus,
worker: &dyn TaskState,
) -> Result<(), Error> {
use nix::sys::stat::fstatat;
use nix::unistd::{unlinkat, UnlinkatFlags};
let mut min_atime = phase1_start_time - 3600*24; // at least 24h (see mount option relatime)
if oldest_writer < min_atime {
min_atime = oldest_writer;
}
min_atime -= 300; // add 5 mins gap for safety
let mut last_percentage = 0;
let mut chunk_count = 0;
for (entry, percentage, bad) in self.get_chunk_iterator()? {
if last_percentage != percentage {
last_percentage = percentage;
crate::task_log!(
worker,
"processed {}% ({} chunks)",
percentage,
chunk_count,
);
}
worker.check_abort()?;
tools::fail_on_shutdown()?;
let (dirfd, entry) = match entry {
Ok(entry) => (entry.parent_fd(), entry),
Err(err) => bail!("chunk iterator on chunk store '{}' failed - {}", self.name, err),
};
let file_type = match entry.file_type() {
Some(file_type) => file_type,
None => bail!("unsupported file system type on chunk store '{}'", self.name),
};
if file_type != nix::dir::Type::File {
continue;
}
chunk_count += 1;
let filename = entry.file_name();
let lock = self.mutex.lock();
if let Ok(stat) = fstatat(dirfd, filename, nix::fcntl::AtFlags::AT_SYMLINK_NOFOLLOW) {
if stat.st_atime < min_atime {
//let age = now - stat.st_atime;
//println!("UNLINK {} {:?}", age/(3600*24), filename);
if let Err(err) = unlinkat(Some(dirfd), filename, UnlinkatFlags::NoRemoveDir) {
if bad {
status.still_bad += 1;
}
bail!(
"unlinking chunk {:?} failed on store '{}' - {}",
filename,
self.name,
err,
);
}
if bad {
status.removed_bad += 1;
} else {
status.removed_chunks += 1;
}
status.removed_bytes += stat.st_size as u64;
} else if stat.st_atime < oldest_writer {
if bad {
status.still_bad += 1;
} else {
status.pending_chunks += 1;
}
status.pending_bytes += stat.st_size as u64;
} else {
if !bad {
status.disk_chunks += 1;
}
status.disk_bytes += stat.st_size as u64;
}
}
drop(lock);
}
Ok(())
}
pub fn insert_chunk(
&self,
chunk: &DataBlob,
digest: &[u8; 32],
) -> Result<(bool, u64), Error> {
//println!("DIGEST {}", proxmox::tools::digest_to_hex(digest));
let (chunk_path, digest_str) = self.chunk_path(digest);
let lock = self.mutex.lock();
if let Ok(metadata) = std::fs::metadata(&chunk_path) {
if metadata.is_file() {
self.touch_chunk(digest)?;
return Ok((true, metadata.len()));
} else {
bail!("Got unexpected file type on store '{}' for chunk {}", self.name, digest_str);
}
}
let mut tmp_path = chunk_path.clone();
tmp_path.set_extension("tmp");
let mut file = std::fs::File::create(&tmp_path)?;
let raw_data = chunk.raw_data();
let encoded_size = raw_data.len() as u64;
file.write_all(raw_data)?;
if let Err(err) = std::fs::rename(&tmp_path, &chunk_path) {
if std::fs::remove_file(&tmp_path).is_err() { /* ignore */ }
bail!(
"Atomic rename on store '{}' failed for chunk {} - {}",
self.name,
digest_str,
err,
);
}
drop(lock);
Ok((false, encoded_size))
}
pub fn chunk_path(&self, digest:&[u8; 32]) -> (PathBuf, String) {
let mut chunk_path = self.chunk_dir.clone();
let prefix = digest_to_prefix(digest);
chunk_path.push(&prefix);
let digest_str = proxmox::tools::digest_to_hex(digest);
chunk_path.push(&digest_str);
(chunk_path, digest_str)
}
pub fn relative_path(&self, path: &Path) -> PathBuf {
let mut full_path = self.base.clone();
full_path.push(path);
full_path
}
pub fn name(&self) -> &str {
&self.name
}
pub fn base_path(&self) -> PathBuf {
self.base.clone()
}
pub fn try_shared_lock(&self) -> Result<tools::ProcessLockSharedGuard, Error> {
tools::ProcessLocker::try_shared_lock(self.locker.clone())
}
pub fn try_exclusive_lock(&self) -> Result<tools::ProcessLockExclusiveGuard, Error> {
tools::ProcessLocker::try_exclusive_lock(self.locker.clone())
}
}
#[test]
fn test_chunk_store1() {
let mut path = std::fs::canonicalize(".").unwrap(); // we need absolute path
path.push(".testdir");
if let Err(_e) = std::fs::remove_dir_all(".testdir") { /* ignore */ }
let chunk_store = ChunkStore::open("test", &path);
assert!(chunk_store.is_err());
let user = nix::unistd::User::from_uid(nix::unistd::Uid::current()).unwrap().unwrap();
let chunk_store = ChunkStore::create("test", &path, user.uid, user.gid).unwrap();
let (chunk, digest) = super::DataChunkBuilder::new(&[0u8, 1u8]).build().unwrap();
let (exists, _) = chunk_store.insert_chunk(&chunk, &digest).unwrap();
assert!(!exists);
let (exists, _) = chunk_store.insert_chunk(&chunk, &digest).unwrap();
assert!(exists);
let chunk_store = ChunkStore::create("test", &path, user.uid, user.gid);
assert!(chunk_store.is_err());
if let Err(_e) = std::fs::remove_dir_all(".testdir") { /* ignore */ }
}