[PATCH proxmox-backup v2 2/3] fix #7400: api: gracefully handle corrupted job statefiles

["Michael Köppl" <m.koeppl@proxmox.com>]

Previously, if a job statefile was empty or corrupted (e.g. due to an
I/O error or an abrupt shutdown), the JobStatus::load method would
return an error that would be propagated up, causing the endpoint to
return an error to the user, meaning users would not see any of their
jobs if a single job had a corrupted statefile.

Instead, handle the error explicitly, logging an error message and
returning a default JobScheduleStatus such that jobs lists can still be
fetched, displaying the affected job as configured but simply missing
its last run status.

Signed-off-by: Michael Köppl <m.koeppl@proxmox.com>
---
 src/server/jobstate.rs | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/server/jobstate.rs b/src/server/jobstate.rs
index cfb0b8945..638beac3e 100644
--- a/src/server/jobstate.rs
+++ b/src/server/jobstate.rs
@@ -305,8 +305,17 @@ pub fn compute_schedule_status(
     jobname: &str,
     schedule: Option<&str>,
 ) -> Result<JobScheduleStatus, Error> {
-    let job_state = JobState::load(jobtype, jobname)
-        .map_err(|err| format_err!("could not open statefile for {}: {}", jobname, err))?;
+    let job_state = match JobState::load(jobtype, jobname) {
+        Ok(job_state) => job_state,
+        Err(err) => {
+            log::error!(
+                "could not open statefile for {}: {} - falling back to default job schedule status",
+                jobname,
+                err
+            );
+            return Ok(JobScheduleStatus::default());
+        }
+    };
 
     let (upid, endtime, state, last) = match job_state {
         JobState::Created { time } => (None, None, None, time),
-- 
2.47.3