Re: [PATCH] generic/793: limit number of overwrites

On Apr 24, 2026 / 08:22, Johannes Thumshirn wrote:
> Testcase generic/793 overwrites a 1GB file "number of sequential zones"
> times in order to trigger a bug in zoned BTRFS' garbage collection. But on
> scratch devices with a huge number of sequential zones (like SMR drives)
> this can cause very long runtimes.
> 
> As the testcase also limits the filesystem size to 16GB, constraint the
> number of overwrite loops to the number of sequential zones in the
> filesystem. This still guarantees that the file will be overwritten often
> enough to trigger the bug while not exploding the overall test runtime.
> 
> Reported-by: Shin'ichiro Kawasaki <[email protected]>
> Signed-off-by: Johannes Thumshirn <[email protected]>

Thanks for the fix. Without this fix, the testcase run for SMR drives did not
complete even after 10 hours run. I applied the patch and confrimed that the
testcase completes within 7 minutes or so.

Tested-by: Shin'ichiro Kawasaki <[email protected]>