[pbs-devel] [PATCH proxmox-backup] async_lru_cache: fix handling of errors in fetch

[pbs-devel] [PATCH proxmox-backup] async_lru_cache: fix handling of errors in fetch

[Stefan Reiter]

The future needs to be removed from the pending map in any case, even if
it returned an error, else all upcoming calls to access this key will
always return the same error.

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
---

I don't think this can happen at the moment, as we only use this in parts of the
code were one returned error already causes an abort, but should still be fixed.

 src/tools/async_lru_cache.rs | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/tools/async_lru_cache.rs b/src/tools/async_lru_cache.rs
index cc385ec9..62e74fcd 100644
--- a/src/tools/async_lru_cache.rs
+++ b/src/tools/async_lru_cache.rs
@@ -65,15 +65,16 @@ impl<K: std::cmp::Eq + std::hash::Hash + Copy, V: Clone + Send + 'static> AsyncL
         };
 
         let result = result_fut.await;
-        match result {
-            Ok(Some(ref value)) if owner => {
-                // this call was the one initiating the request, put into LRU and remove from map
-                let mut maps = self.maps.lock().unwrap();
+
+        if owner {
+            // this call was the one initiating the request, put into LRU and remove from map
+            let mut maps = self.maps.lock().unwrap();
+            if let Ok(Some(ref value)) = result {
                 maps.0.insert(key, value.clone());
-                maps.1.remove(&key);
             }
-            _ => {}
+            maps.1.remove(&key);
         }
+
         result
     }
 }
-- 
2.30.2

[pbs-devel] applied: [PATCH proxmox-backup] async_lru_cache: fix handling of errors in fetch

[Wolfgang Bumiller]

applied

On Thu, Jun 17, 2021 at 11:02:32AM +0200, Stefan Reiter wrote:
> The future needs to be removed from the pending map in any case, even if
> it returned an error, else all upcoming calls to access this key will
> always return the same error.
> 
> Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
> ---
> 
> I don't think this can happen at the moment, as we only use this in parts of the
> code were one returned error already causes an abort, but should still be fixed.
> 
>  src/tools/async_lru_cache.rs | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/src/tools/async_lru_cache.rs b/src/tools/async_lru_cache.rs
> index cc385ec9..62e74fcd 100644
> --- a/src/tools/async_lru_cache.rs
> +++ b/src/tools/async_lru_cache.rs
> @@ -65,15 +65,16 @@ impl<K: std::cmp::Eq + std::hash::Hash + Copy, V: Clone + Send + 'static> AsyncL
>          };
>  
>          let result = result_fut.await;
> -        match result {
> -            Ok(Some(ref value)) if owner => {
> -                // this call was the one initiating the request, put into LRU and remove from map
> -                let mut maps = self.maps.lock().unwrap();
> +
> +        if owner {
> +            // this call was the one initiating the request, put into LRU and remove from map
> +            let mut maps = self.maps.lock().unwrap();
> +            if let Ok(Some(ref value)) = result {
>                  maps.0.insert(key, value.clone());
> -                maps.1.remove(&key);
>              }
> -            _ => {}
> +            maps.1.remove(&key);
>          }
> +
>          result
>      }
>  }
> -- 
> 2.30.2