On Thu, Nov 21, 2024 at 06:08:53PM +0530, Ojaswin Mujoo wrote: > Changes since v1: Forgot to link v1: https://lore.kernel.org/linux-ext4/20241115183449.2058590-1-ojaswin@xxxxxxxxxxxxx/T/#t > > * Patch 1: Move flush_delayed_work() to start of function > * Patch 2: Guard ext4_release_dquot against freeze > > Regarding patch 2, as per my understanding of the journalling code, > right now ext4_release_dquot() can only be called from the > quota_realease_work workqueue and hence ideally should never have a > journal open but to future-proof it we make sure the journal is not > opened when calling sb_start_inwrite(). > > ** Original Cover ** > > Recently we noticed generic/390 failing on powerpc systems. This test > basically does a freeze-unfreeze loop in parallel with fsstress on the > FS to detect any races in the code paths. > > We noticed that the test started failing due to kernel WARN_ONs because > quota_release_work workqueue started executing while the FS was frozen > which led to creating new transactions in ext4_release_quota. > > Most of the details are in the bug however I'd just like to add that > I'm completely new to quota code so the patch, although fixing the > issue, might be not be logically the right thing to do. So reviews and > suggestions are welcome. > > Also, I can only replicate this race on one of my machines reliably and > does not appear on others. I've tested with with fstests -g quota and > don't see any new failures. > > Ojaswin Mujoo (2): > quota: flush quota_release_work upon quota writeback > ext4: protect ext4_release_dquot against freezing > > fs/ext4/super.c | 17 +++++++++++++++++ > fs/quota/dquot.c | 2 ++ > 2 files changed, 19 insertions(+) > > -- > 2.43.5 >
