[PATCH v6 proxmox-backup 01/18] datastore: remove Arc<ChunkStore> from FixedIndexWriter

[Robert Obkircher <r.obkircher@proxmox.com>]

The ChunkStore reference can be safely removed, because it was only
needed for the base directory. As discussed previously in the context
of the DynamicIndexWriter [1], it is the callers responsibility to
ensure that the writer doesn't outlive any locks.

This simplifies testing the writer, which would otherwise require a
workaround to avoid creating 65k directories.

[1] https://lore.proxmox.com/pbs-devel/1761822027.sm41v71zmk.astroid@yuna.none/

Signed-off-by: Robert Obkircher <r.obkircher@proxmox.com>
---
 pbs-datastore/src/datastore.rs   | 10 ++--------
 pbs-datastore/src/fixed_index.rs |  7 ++-----
 2 files changed, 4 insertions(+), 13 deletions(-)

diff --git a/pbs-datastore/src/datastore.rs b/pbs-datastore/src/datastore.rs
index 7ad3d917..1c631817 100644
--- a/pbs-datastore/src/datastore.rs
+++ b/pbs-datastore/src/datastore.rs
@@ -698,14 +698,8 @@ impl DataStore {
         size: usize,
         chunk_size: usize,
     ) -> Result<FixedIndexWriter, Error> {
-        let index = FixedIndexWriter::create(
-            self.inner.chunk_store.clone(),
-            filename.as_ref(),
-            size,
-            chunk_size,
-        )?;
-
-        Ok(index)
+        let full_path = self.inner.chunk_store.relative_path(filename.as_ref());
+        FixedIndexWriter::create(full_path, size, chunk_size)
     }
 
     pub fn open_fixed_reader<P: AsRef<Path>>(
diff --git a/pbs-datastore/src/fixed_index.rs b/pbs-datastore/src/fixed_index.rs
index 6c3be2d4..becbe3e3 100644
--- a/pbs-datastore/src/fixed_index.rs
+++ b/pbs-datastore/src/fixed_index.rs
@@ -4,14 +4,12 @@ use std::io::{Seek, SeekFrom};
 use std::os::unix::io::AsRawFd;
 use std::path::{Path, PathBuf};
 use std::ptr::NonNull;
-use std::sync::Arc;
 
 use anyhow::{bail, format_err, Error};
 
 use proxmox_io::ReadExt;
 use proxmox_uuid::Uuid;
 
-use crate::chunk_store::ChunkStore;
 use crate::file_formats;
 use crate::index::{ChunkReadInfo, IndexFile};
 
@@ -240,12 +238,11 @@ impl FixedIndexWriter {
     #[allow(clippy::cast_ptr_alignment)]
     // Requires obtaining a shared chunk store lock beforehand
     pub fn create(
-        store: Arc<ChunkStore>,
-        path: &Path,
+        full_path: impl Into<PathBuf>,
         size: usize,
         chunk_size: usize,
     ) -> Result<Self, Error> {
-        let full_path = store.relative_path(path);
+        let full_path = full_path.into();
         let mut tmp_path = full_path.clone();
         tmp_path.set_extension("tmp_fidx");
 
-- 
2.47.3