[pbs-devel] [PATCH proxmox-backup v2 3/3] index writers: remove chunk store lock

[Fabian Grünbichler]

the only user of these (the backup session) now holds its own chunk store lock
for the duration of the backup, like pull and tape already do as well.

Signed-off-by: Fabian Grünbichler <f.gruenbichler at proxmox.com>
---

Notes:
    we could extend the process locker to allow checking whether a certain guard id
    is still valid as a safeguard. passing around references to the guard itself
    from the backup session down here is very cumbersome..

 pbs-datastore/src/datastore.rs     | 2 ++
 pbs-datastore/src/dynamic_index.rs | 6 +-----
 pbs-datastore/src/fixed_index.rs   | 6 +-----
 3 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/pbs-datastore/src/datastore.rs b/pbs-datastore/src/datastore.rs
index 319d82faa..34401f231 100644
--- a/pbs-datastore/src/datastore.rs
+++ b/pbs-datastore/src/datastore.rs
@@ -533,6 +533,7 @@ impl DataStore {
         self.inner.chunk_store.get_chunk_iterator()
     }
 
+    // Requires obtaining a shared chunk store lock beforehand
     pub fn create_fixed_writer<P: AsRef<Path>>(
         &self,
         filename: P,
@@ -560,6 +561,7 @@ impl DataStore {
         Ok(index)
     }
 
+    // Requires obtaining a shared chunk store lock beforehand
     pub fn create_dynamic_writer<P: AsRef<Path>>(
         &self,
         filename: P,
diff --git a/pbs-datastore/src/dynamic_index.rs b/pbs-datastore/src/dynamic_index.rs
index 83e13b311..ff6c36782 100644
--- a/pbs-datastore/src/dynamic_index.rs
+++ b/pbs-datastore/src/dynamic_index.rs
@@ -11,7 +11,6 @@ use anyhow::{bail, format_err, Error};
 
 use proxmox_io::ReadExt;
 use proxmox_sys::mmap::Mmap;
-use proxmox_sys::process_locker::ProcessLockSharedGuard;
 use proxmox_uuid::Uuid;
 use pxar::accessor::{MaybeReady, ReadAt, ReadAtOperation};
 
@@ -277,7 +276,6 @@ impl IndexFile for DynamicIndexReader {
 /// Create dynamic index files (`.dixd`)
 pub struct DynamicIndexWriter {
     store: Arc<ChunkStore>,
-    _lock: ProcessLockSharedGuard,
     writer: BufWriter<File>,
     closed: bool,
     filename: PathBuf,
@@ -294,9 +292,8 @@ impl Drop for DynamicIndexWriter {
 }
 
 impl DynamicIndexWriter {
+    // Requires obtaining a shared chunk store lock beforehand
     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");
@@ -325,7 +322,6 @@ impl DynamicIndexWriter {
 
         Ok(Self {
             store,
-            _lock: shared_lock,
             writer,
             closed: false,
             filename: full_path,
diff --git a/pbs-datastore/src/fixed_index.rs b/pbs-datastore/src/fixed_index.rs
index 8d9173e86..0f289543f 100644
--- a/pbs-datastore/src/fixed_index.rs
+++ b/pbs-datastore/src/fixed_index.rs
@@ -9,7 +9,6 @@ use std::sync::Arc;
 use anyhow::{bail, format_err, Error};
 
 use proxmox_io::ReadExt;
-use proxmox_sys::process_locker::ProcessLockSharedGuard;
 use proxmox_uuid::Uuid;
 
 use crate::chunk_stat::ChunkStat;
@@ -218,7 +217,6 @@ impl IndexFile for FixedIndexReader {
 pub struct FixedIndexWriter {
     store: Arc<ChunkStore>,
     file: File,
-    _lock: ProcessLockSharedGuard,
     filename: PathBuf,
     tmp_filename: PathBuf,
     chunk_size: usize,
@@ -243,14 +241,13 @@ impl Drop for FixedIndexWriter {
 
 impl FixedIndexWriter {
     #[allow(clippy::cast_ptr_alignment)]
+    // Requires obtaining a shared chunk store lock beforehand
     pub fn create(
         store: Arc<ChunkStore>,
         path: &Path,
         size: usize,
         chunk_size: usize,
     ) -> 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_fidx");
@@ -307,7 +304,6 @@ impl FixedIndexWriter {
         Ok(Self {
             store,
             file,
-            _lock: shared_lock,
             filename: full_path,
             tmp_filename: tmp_path,
             chunk_size,
-- 
2.47.3