Re: [PATCH proxmox-backup] api/tools: avoid showing error on missing manifest during file listing

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

On 4/27/26 11:22 AM, Fabian Grünbichler wrote:
> On April 26, 2026 10:03 am, Christian Ebner wrote:
>> When listing the contents of a datastore, a missing manifest blob
>> file is currently being logged as error to the systemd journal [0].
>> The manifest missing is however normal operation in case of a still
>> ongoing backup. Therefore, refactor the code such that a missing
>> manifest is not treated as regular error by returning an Option::None
>> in the read_backup_index() helper, and handle this case accordingly.
>>
>> The actual check for the missing manifest should further be improved,
>> but requires a more in depth refactoring, the changes here acting as
>> a stop gap for not showing the benign error the time being.
> 
> how about the following instead? only log the error if the manifest file
> has existed before we tried to load and parse it? that should limit the
> log spam to
> - actually broken manifests
> - manifests which disappear right between those two calls
> 

That has one major downside though: This is a highly critical code path, 
the content listing having already been reworked quite a bit int the 
past to not be slow.

So your suggested changes would now unconditionally add more syscalls 
and IO?

I think it would be better to refactor the code in the long run, so a 
missing manifest would be treated differently from parsing and other IO 
errors, and bubbled up to the call site for logging.