tyler/proxmox-backup
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use new atomic_open_or_create_file

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Factor out open_backup_lockfile() method to acquire locks owned by
user backup with permission 0660.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
This commit is contained in:
Dietmar Maurer
2021-07-20 13:51:54 +02:00
committed by Thomas Lamprecht
parent a00888e93f
commit 7526d86419
29 changed files with 161 additions and 270 deletions
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46
src/tape/drive/mod.rs
View File

@ -5,19 +5,21 @@ mod virtual_tape;
mod lto;
pub use lto::*;
use std::os::unix::io::AsRawFd;
use std::path::PathBuf;
use anyhow::{bail, format_err, Error};
use ::serde::{Deserialize};
use serde_json::Value;
use nix::fcntl::OFlag;
use nix::sys::stat::Mode;
use proxmox::{
tools::{
Uuid,
io::ReadExt,
fs::{
fchown,
lock_file,
atomic_open_or_create_file,
file_read_optional_string,
replace_file,
CreateOptions,
@ -604,20 +606,34 @@ fn tape_device_path(
pub struct DeviceLockGuard(std::fs::File);
// Acquires an exclusive lock on `device_path`
//
// Uses systemd escape_unit to compute a file name from `device_path`, the try
// to lock `/var/lock/<name>`.
fn lock_device_path(device_path: &str) -> Result<DeviceLockGuard, TapeLockError> {
fn open_device_lock(device_path: &str) -> Result<std::fs::File, Error> {
let lock_name = crate::tools::systemd::escape_unit(device_path, true);
let mut path = std::path::PathBuf::from(crate::tape::DRIVE_LOCK_DIR);
path.push(lock_name);
let user = crate::backup::backup_user()?;
let options = CreateOptions::new()
.perm(Mode::from_bits_truncate(0o660))
.owner(user.uid)
.group(user.gid);
atomic_open_or_create_file(
path,
OFlag::O_RDWR | OFlag::O_CLOEXEC | OFlag::O_APPEND,
&[],
options,
)
}
// Acquires an exclusive lock on `device_path`
//
fn lock_device_path(device_path: &str) -> Result<DeviceLockGuard, TapeLockError> {
let mut file = open_device_lock(device_path)?;
let timeout = std::time::Duration::new(10, 0);
let mut file = std::fs::OpenOptions::new().create(true).append(true).open(path)?;
if let Err(err) = proxmox::tools::fs::lock_file(&mut file, true, Some(timeout)) {
if let Err(err) = lock_file(&mut file, true, Some(timeout)) {
if err.kind() == std::io::ErrorKind::Interrupted {
return Err(TapeLockError::TimeOut);
} else {
@ -625,9 +641,6 @@ fn lock_device_path(device_path: &str) -> Result<DeviceLockGuard, TapeLockError>
}
}
let backup_user = crate::backup::backup_user()?;
fchown(file.as_raw_fd(), Some(backup_user.uid), Some(backup_user.gid))?;
Ok(DeviceLockGuard(file))
}
@ -635,14 +648,10 @@ fn lock_device_path(device_path: &str) -> Result<DeviceLockGuard, TapeLockError>
// non-blocking, and returning if the file is locked or not
fn test_device_path_lock(device_path: &str) -> Result<bool, Error> {
let lock_name = crate::tools::systemd::escape_unit(device_path, true);
let mut path = std::path::PathBuf::from(crate::tape::DRIVE_LOCK_DIR);
path.push(lock_name);
let mut file = open_device_lock(device_path)?;
let timeout = std::time::Duration::new(0, 0);
let mut file = std::fs::OpenOptions::new().create(true).append(true).open(path)?;
match proxmox::tools::fs::lock_file(&mut file, true, Some(timeout)) {
match lock_file(&mut file, true, Some(timeout)) {
// file was not locked, continue
Ok(()) => {},
// file was locked, return true
@ -650,8 +659,5 @@ fn test_device_path_lock(device_path: &str) -> Result<bool, Error> {
Err(err) => bail!("{}", err),
}
let backup_user = crate::backup::backup_user()?;
fchown(file.as_raw_fd(), Some(backup_user.uid), Some(backup_user.gid))?;
Ok(false)
}

3
src/tape/drive/virtual_tape.rs
View File

@ -49,8 +49,9 @@ impl VirtualTapeDrive {
let mut lock_path = std::path::PathBuf::from(&self.path);
lock_path.push(".drive.lck");
let options = CreateOptions::new();
let timeout = std::time::Duration::new(10, 0);
let lock = proxmox::tools::fs::open_file_locked(&lock_path, timeout, true)?;
let lock = proxmox::tools::fs::open_file_locked(&lock_path, timeout, true, options)?;
Ok(VirtualTapeHandle {
_lock: lock,