Re: [PATCH v1 proxmox-backup 2/2] datastore: rephrase error messages for failed chunk insert

[Christian Ebner <c.ebner@proxmox.com>]

On 8/7/26 11:58 AM, Robert Obkircher wrote:
> The "not allowed" phrasing sounds like an access-right problem, when
> the actual problem is likely file corruption.
> 
> Link: https://forum.proxmox.com/threads/184140
> Signed-off-by: Robert Obkircher <r.obkircher@proxmox.com>
> ---
>   pbs-datastore/src/chunk_store.rs | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/pbs-datastore/src/chunk_store.rs b/pbs-datastore/src/chunk_store.rs
> index 3f637730c..d9d0c9a26 100644
> --- a/pbs-datastore/src/chunk_store.rs
> +++ b/pbs-datastore/src/chunk_store.rs
> @@ -718,7 +718,7 @@ impl ChunkStore {
>                   // includes data derived from the encryption key
>                   if magic == UNCOMPRESSED_BLOB_MAGIC_1_0 || magic == COMPRESSED_BLOB_MAGIC_1_0 {
>                       bail!(
> -                        "Overwriting unencrypted chunk '{digest_str}' on store '{name}' with encrypted chunk with same digest not allowed!"
> +                        "Cannot overwrite existing unencrypted chunk '{digest_str}' on store '{name}' with encrypted chunk."
>                       );
>                   }
>   
> @@ -726,7 +726,7 @@ impl ChunkStore {
>                   // their sizes are different, one of them *must* be invalid
>                   if magic == ENCRYPTED_BLOB_MAGIC_1_0 && !chunk.is_compressed() {
>                       bail!(
> -                        "Overwriting existing (encrypted) chunk '{digest_str}' on store '{name}' is not allowed!"
> +                        "Found existing encrypted chunk '{digest_str}' of different size on store '{name}'. Consider running verification and garbage-collection because it may be corrupted.",

question: pre-existing but since one of the chunks must be the corrupt 
one here, and the server checks the CRC sum on upload, the new chunk is 
most likely to be the fine one. Might be worth to decode the full 
on-disk chunk then and double check its CRC? An only bail if both are 
fine, which is very unlikely?

anyways, I suggest to modify the error message to be a bit more concise:

"Unexpected encrypted chunk {} with different size already present on 
store {}. Run verification to detect possibly corrupt chunks."

>                       )
>                   }
>