From: Stefan Sterz <s.sterz@proxmox.com>
To: pbs-devel@lists.proxmox.com
Subject: [pbs-devel] [PATCH proxmox-backup v4 4/5] fix #3935: datastore: move manifest locking to new locking method
Date: Tue, 5 Jul 2022 16:54:17 +0200 [thread overview]
Message-ID: <20220705145418.388066-5-s.sterz@proxmox.com> (raw)
In-Reply-To: <20220705145418.388066-1-s.sterz@proxmox.com>
adds double stat'ing and removes directory hierarchy to bring manifest
locking in-line with other locks used by the BackupDir trait.
Signed-off-by: Stefan Sterz <s.sterz@proxmox.com>
---
pbs-datastore/src/backup_info.rs | 35 ++++++++++++++++----------------
1 file changed, 18 insertions(+), 17 deletions(-)
diff --git a/pbs-datastore/src/backup_info.rs b/pbs-datastore/src/backup_info.rs
index 046ed6e9..43712700 100644
--- a/pbs-datastore/src/backup_info.rs
+++ b/pbs-datastore/src/backup_info.rs
@@ -443,25 +443,29 @@ impl BackupDir {
/// Returns the filename to lock a manifest
///
/// Also creates the basedir. The lockfile is located in
- /// '/run/proxmox-backup/locks/{datastore}/[ns/{ns}/]+{type}/{id}/{timestamp}.index.json.lck'
- fn manifest_lock_path(&self) -> Result<PathBuf, Error> {
- let mut path = PathBuf::from(&format!("/run/proxmox-backup/locks/{}", self.store.name()));
- path.push(self.relative_path());
+ /// `${DATASTORE_LOCKS_DIR}/${datastore name}/${lock_file_name_helper(rpath)}.index.json.lck`
+ /// where rpath is the relative path of the snapshot.
+ ///
+ /// If the snapshot's relative path contains non-Unicode sequences they will be replaced via
+ /// [std::ffi::OsStr::to_string_lossy()].
+ fn manifest_lock_path(&self) -> PathBuf {
+ let path = Path::new(DATASTORE_LOCKS_DIR).join(self.store.name());
- std::fs::create_dir_all(&path)?;
- let ts = self.backup_time_string();
- path.push(&format!("{ts}{MANIFEST_LOCK_NAME}"));
+ let rpath = self.relative_path().join(&format!("{MANIFEST_LOCK_NAME}"));
+ let rpath = rpath.as_os_str().to_string_lossy();
- Ok(path)
+ path.join(lock_file_name_helper(&rpath))
}
/// Locks the manifest of a snapshot, for example, to update or delete it.
pub(crate) fn lock_manifest(&self) -> Result<BackupLockGuard, Error> {
- let path = self.manifest_lock_path()?;
-
- // actions locking the manifest should be relatively short, only wait a few seconds
- open_backup_lockfile(&path, Some(std::time::Duration::from_secs(5)), true)
- .map_err(|err| format_err!("unable to acquire manifest lock {:?} - {}", &path, err))
+ lock_helper(self.store.name(), &self.manifest_lock_path(), |p| {
+ // update_manifest should never take a long time, so if
+ // someone else has the lock we can simply block a bit
+ // and should get it soon
+ open_backup_lockfile(&p, Some(Duration::from_secs(5)), true)
+ .map_err(|err| format_err!("unable to acquire manifest lock {p:?} - {err}"))
+ })
}
/// Returns a file name for locking a snapshot.
@@ -518,10 +522,7 @@ impl BackupDir {
})?;
// remove no longer needed lock files
- if let Ok(path) = self.manifest_lock_path() {
- let _ = std::fs::remove_file(path); // ignore errors
- }
-
+ let _ = std::fs::remove_file(self.manifest_lock_path()); // ignore errors
let _ = std::fs::remove_file(self.lock_path()); // ignore errors
Ok(())
--
2.30.2
next prev parent reply other threads:[~2022-07-05 14:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-05 14:54 [pbs-devel] [PATCH proxmox-backup v4 0/5] refactor datastore locking to use tmpfs Stefan Sterz
2022-07-05 14:54 ` [pbs-devel] [PATCH proxmox-backup v4 1/5] fix: datastore: make relative_group_path() return relative path Stefan Sterz
2022-07-05 14:54 ` [pbs-devel] [PATCH proxmox-backup v4 2/5] fix #3935: datastore/api/backup: add lock helpers to backup dir/group Stefan Sterz
2022-07-05 14:54 ` [pbs-devel] [PATCH proxmox-backup v4 3/5] fix #3935: datastore/api/backup: move datastore locking to '/run' Stefan Sterz
2022-07-05 14:54 ` Stefan Sterz [this message]
2022-07-05 14:54 ` [pbs-devel] [PATCH proxmox-backup v4 5/5] fix: api: avoid race condition in set_backup_owner Stefan Sterz
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