[pbs-devel] [PATCH proxmox-backup] garbage-collect: switch to tokio Mutex

[Fabian Grünbichler]

this Mutex is held for the duration of the whole garbage collection run, which
now includes async calls into S3 code. this is not a highly contested lock, so
switching to the more expensive tokio variant shouldn't cause noticeable
overhead, and fix potential deadlock problems that could occur because of
holding the lock guard across await points.

Signed-off-by: Fabian Grünbichler <f.gruenbichler at proxmox.com>
---
also found while going through std::sync::Mutex usage with S3

 pbs-datastore/src/datastore.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pbs-datastore/src/datastore.rs b/pbs-datastore/src/datastore.rs
index 7cf020fc0..68043e7a5 100644
--- a/pbs-datastore/src/datastore.rs
+++ b/pbs-datastore/src/datastore.rs
@@ -136,7 +136,7 @@ pub fn ensure_datastore_is_mounted(config: &DataStoreConfig) -> Result<(), Error
 /// management interface for backup.
 pub struct DataStoreImpl {
     chunk_store: Arc<ChunkStore>,
-    gc_mutex: Mutex<()>,
+    gc_mutex: tokio::sync::Mutex<()>,
     last_gc_status: Mutex<GarbageCollectionStatus>,
     verify_new: bool,
     chunk_order: ChunkOrder,
@@ -152,7 +152,7 @@ impl DataStoreImpl {
     pub(crate) unsafe fn new_test() -> Arc<Self> {
         Arc::new(Self {
             chunk_store: Arc::new(unsafe { ChunkStore::panic_store() }),
-            gc_mutex: Mutex::new(()),
+            gc_mutex: tokio::sync::Mutex::new(()),
             last_gc_status: Mutex::new(GarbageCollectionStatus::default()),
             verify_new: false,
             chunk_order: Default::default(),
@@ -513,7 +513,7 @@ impl DataStore {
 
         Ok(DataStoreImpl {
             chunk_store,
-            gc_mutex: Mutex::new(()),
+            gc_mutex: tokio::sync::Mutex::new(()),
             last_gc_status: Mutex::new(gc_status),
             verify_new: config.verify_new.unwrap_or(false),
             chunk_order: tuning.chunk_order.unwrap_or_default(),
-- 
2.47.3