Re: sporadic hangs on generic/186

[Chuck Lever III <chuck.lever@oracle.com>]

> On Apr 6, 2022, at 3:54 PM, J. Bruce Fields <bfields@fieldses.org> wrote:
> 
> In the last couple days I've started getting hangs on xfstests
> generic/186 on upstream.  I also notice the test completes after 10+
> hours (usually it takes about 5 minutes).  Sometimes this is accompanied
> by "nfs: RPC call returned error 12" on the client.
> 
> Test description is:
> 
> # Ensuring that copy on write in buffered mode works when free space
> # is heavily fragmented.
> #   - Create two files
> #   - Reflink the odd blocks of the first file into a third file.
> #   - Reflink the even blocks of the second file into the third file.
> #   - Try to fragment the free space by allocating a huge file and
> #     punching out every other block.
> #   - CoW across the halfway mark.
> #   - Check that the files are now different where we say they're
> #   different.
> 
> so maybe it's really some xfs change, I don't know.  Or maybe it's a
> problem with my particular test filesystem (which doesn't get recreated
> for each test run).
> 
> The problem doesn't reproduce easily enough to bisect.
> 
> I may just turn off that test for now.

Thanks for the report.

I don't have a SCRATCH_DEV so generic/186 isn't run on my systems.


--
Chuck Lever