[pbs-devel] [PATCH proxmox-backup v3 15/23] fix #6961: datastore: verify: evict corrupt chunks from in-memory LRU cache

[Christian Ebner]

lock cache store on rename of fs backed datastores and additional
per-chunk file lock on s3 backend.

Chunks detected as corrupt have been renamed on both, the S3 backend
and the local datastore cache, but not evicted from the in-memory
cache containing the LRU chunk digests. This can lead to the chunks
being considered as already present if their digest is still cached,
and therefore not being re-inserted in the local store cache and S3
backend on backup upload.

Fix this by not only renaming the local datastore's chunk marker
file, but also removing it from the in-memory cache while holding the
chunk store mutex lock to exclude interference from concurrent chunk
inserts.

Reported-by: Fabian Grünbichler <f.gruenbichler at proxmox.com>
Fixes: https://bugzilla.proxmox.com/show_bug.cgi?id=6961
Signed-off-by: Christian Ebner <c.ebner at proxmox.com>
---
changes since version 2:
- no changes

 pbs-datastore/src/datastore.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/pbs-datastore/src/datastore.rs b/pbs-datastore/src/datastore.rs
index 81630e7f9..698486ff4 100644
--- a/pbs-datastore/src/datastore.rs
+++ b/pbs-datastore/src/datastore.rs
@@ -2622,6 +2622,11 @@ impl DataStore {
             }
         }
 
+        if let Some(cache) = self.cache() {
+            // Locks are being held, so it is safe to call the method
+            let _ = unsafe { cache.remove(digest) };
+        }
+
         let result = match std::fs::rename(&path, &new_path) {
             Ok(_) => Ok(Some(new_path)),
             Err(err) if err.kind() == std::io::ErrorKind::NotFound => Ok(None),
-- 
2.47.3