move tools::process_locker to pbs-tools

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
This commit is contained in:
Wolfgang Bumiller 2021-07-07 14:15:42 +02:00
parent 95f9d67ce9
commit 83771aa037
3 changed files with 44 additions and 24 deletions

View File

@ -3,6 +3,7 @@ pub mod format;
pub mod fs;
pub mod json;
pub mod nom;
pub mod process_locker;
pub mod str;
mod command;

View File

@ -7,11 +7,11 @@
//! the timestamp for the oldest open lock with
//! `oldest_shared_lock()`.
use anyhow::{bail, Error};
use std::sync::{Arc, Mutex};
use std::os::unix::io::AsRawFd;
use std::collections::HashMap;
use std::os::unix::io::AsRawFd;
use std::sync::{Arc, Mutex};
use anyhow::{bail, Error};
// fixme: use F_OFD_ locks when implemented with nix::fcntl
@ -38,12 +38,13 @@ impl Drop for ProcessLockSharedGuard {
fn drop(&mut self) {
let mut data = self.locker.lock().unwrap();
if data.writers == 0 { panic!("unexpected ProcessLocker state"); }
if data.writers == 0 {
panic!("unexpected ProcessLocker state");
}
data.shared_guard_list.remove(&self.guard_id);
if data.writers == 1 && !data.exclusive {
let op = libc::flock {
l_type: libc::F_UNLCK as i16,
l_whence: libc::SEEK_SET as i16,
@ -52,7 +53,9 @@ impl Drop for ProcessLockSharedGuard {
l_pid: 0,
};
if let Err(err) = nix::fcntl::fcntl(data.file.as_raw_fd(), nix::fcntl::FcntlArg::F_SETLKW(&op)) {
if let Err(err) =
nix::fcntl::fcntl(data.file.as_raw_fd(), nix::fcntl::FcntlArg::F_SETLKW(&op))
{
panic!("unable to drop writer lock - {}", err);
}
}
@ -73,9 +76,15 @@ impl Drop for ProcessLockExclusiveGuard {
fn drop(&mut self) {
let mut data = self.locker.lock().unwrap();
if !data.exclusive { panic!("unexpected ProcessLocker state"); }
if !data.exclusive {
panic!("unexpected ProcessLocker state");
}
let ltype = if data.writers != 0 { libc::F_RDLCK } else { libc::F_UNLCK };
let ltype = if data.writers != 0 {
libc::F_RDLCK
} else {
libc::F_UNLCK
};
let op = libc::flock {
l_type: ltype as i16,
l_whence: libc::SEEK_SET as i16,
@ -84,7 +93,9 @@ impl Drop for ProcessLockExclusiveGuard {
l_pid: 0,
};
if let Err(err) = nix::fcntl::fcntl(data.file.as_raw_fd(), nix::fcntl::FcntlArg::F_SETLKW(&op)) {
if let Err(err) =
nix::fcntl::fcntl(data.file.as_raw_fd(), nix::fcntl::FcntlArg::F_SETLKW(&op))
{
panic!("unable to drop exclusive lock - {}", err);
}
@ -93,12 +104,10 @@ impl Drop for ProcessLockExclusiveGuard {
}
impl ProcessLocker {
/// Create a new instance for the specified file.
///
/// This simply creates the file if it does not exist.
pub fn new<P: AsRef<std::path::Path>>(lockfile: P) -> Result<Arc<Mutex<Self>>, Error> {
let file = std::fs::OpenOptions::new()
.create(true)
.read(true)
@ -115,7 +124,6 @@ impl ProcessLocker {
}
fn try_lock(file: &std::fs::File, ltype: i32) -> Result<(), Error> {
let op = libc::flock {
l_type: ltype as i16,
l_whence: libc::SEEK_SET as i16,
@ -133,7 +141,6 @@ impl ProcessLocker {
///
/// On success, this makes sure that no other process can get an exclusive lock for the file.
pub fn try_shared_lock(locker: Arc<Mutex<Self>>) -> Result<ProcessLockSharedGuard, Error> {
let mut data = locker.lock().unwrap();
if data.writers == 0 && !data.exclusive {
@ -144,7 +151,10 @@ impl ProcessLocker {
data.writers += 1;
let guard = ProcessLockSharedGuard { locker: locker.clone(), guard_id: data.next_guard_id };
let guard = ProcessLockSharedGuard {
locker: locker.clone(),
guard_id: data.next_guard_id,
};
data.next_guard_id += 1;
let now = unsafe { libc::time(std::ptr::null_mut()) };
@ -163,7 +173,13 @@ impl ProcessLocker {
for v in data.shared_guard_list.values() {
result = match result {
None => Some(*v),
Some(x) => if x < *v { Some(x) } else { Some(*v) },
Some(x) => {
if x < *v {
Some(x)
} else {
Some(*v)
}
}
};
}
@ -173,8 +189,9 @@ impl ProcessLocker {
/// Try to acquire a exclusive lock
///
/// Make sure the we are the only process which has locks for this file (shared or exclusive).
pub fn try_exclusive_lock(locker: Arc<Mutex<Self>>) -> Result<ProcessLockExclusiveGuard, Error> {
pub fn try_exclusive_lock(
locker: Arc<Mutex<Self>>,
) -> Result<ProcessLockExclusiveGuard, Error> {
let mut data = locker.lock().unwrap();
if data.exclusive {
@ -187,6 +204,8 @@ impl ProcessLocker {
data.exclusive = true;
Ok(ProcessLockExclusiveGuard { locker: locker.clone() })
Ok(ProcessLockExclusiveGuard {
locker: locker.clone(),
})
}
}

View File

@ -26,6 +26,9 @@ use proxmox_http::{
pub use pbs_tools::json;
pub use pbs_tools::nom;
pub use pbs_tools::{run_command, command_output, command_output_as_string};
pub use pbs_tools::process_locker::{
ProcessLocker, ProcessLockExclusiveGuard, ProcessLockSharedGuard
};
pub mod acl;
pub mod apt;
@ -70,9 +73,6 @@ pub use std_channel_writer::StdChannelWriter;
mod tokio_writer_adapter;
pub use tokio_writer_adapter::TokioWriterAdapter;
mod process_locker;
pub use process_locker::{ProcessLocker, ProcessLockExclusiveGuard, ProcessLockSharedGuard};
mod file_logger;
pub use file_logger::{FileLogger, FileLogOptions};