Re: [PATCH 0/3] Fixes for races in relocation and avoid start and wait for unrelated IO

[Filipe Manana <fdmanana@kernel.org>]

On Tue, Apr 26, 2016 at 2:42 PM, Holger Hoffstätte
<holger.hoffstaette@googlemail.com> wrote:
> On Mon, Apr 25, 2016 at 3:01 AM,  <fdmanana@kernel.org> wrote:
>> The following patches fix 2 hard to hit races in relocation that make its
>> first phase (MOVE_DATA_EXTENTS) miss extents, triggers a warning in the
>> second phase (UPDATE_DATA_PTRS) and leaves metadata in an invalid state
>> (file extent items pointing to areas corresponding to the deleted block
>> group), leading to a BUG_ON() when attempting to read those extents after
>> the relocation finishes.
>
> Never saw this particular race/error, but decided to give these
> patches a workout
> to see whether they cause any new or unrelated problems.
>
> Continuous rebalancing (full, partial) for ~30m while unpacking and
> deleting kernel
> trees on a 16GB tmpfs-backed loopback device did not cause any problem;
> balance just cruises along at (sometimes) up to ~1GB/s and does its thing.
> Finally btrfs check also found nothing wrong.
>
> Not sure if this qualifies as testing, but anyway:
>
> Tested-by: Holger Hoffstaette <holger.hoffstaette@googlemail.com>

Thanks. I've now realized I sent the wrong version and patch 1
shouldn't be in the set. I'll resend a v2.


>
> cheers,
> Holger