Re: [btrfs] 62bd8124e2: WARNING:at_fs/btrfs/block-rsv.c:#btrfs_release_global_block_rsv[btrfs]

From: Filipe Manana
Date: Fri Jun 17 2022 - 06:32:58 EST


On Thu, Jun 16, 2022 at 10:42:04AM +0800, Oliver Sang wrote:
> hi, Filipe Manana,
>
> On Mon, Jun 13, 2022 at 11:50:05AM +0100, Filipe Manana wrote:
> >
> > Thanks for running the test again Oliver.
> > Running the fxmark test on my machines, I can't trigger anything.
> >
> > May I ask you to run again the test but with the attached debug patch
> > on top of it?
>
> I reran the test by applied your patch upon 62bd8124e2. one dmesg is attached.
>
> not sure if it supplies enough information? we need some extra effort to
> enable below ftrace in our auto-test framework. so if dmesg is good enough,
> please let us know, then we can save some efforts :) Thanks a lot!

Thanks Oliver.

In the meanwhile I found a way to reproduce the issue with a test case
from fstests, so I now have everything I need to debug and fix the issue.

Thanks!

>
> >
> > Also, if possible, with ftrace enabled like this:
> >
> > modprobe btrfs
> > echo 0 > /sys/kernel/debug/tracing/tracing_on
> > echo > /sys/kernel/debug/tracing/trace
> > echo $((1 << 24)) > /sys/kernel/debug/tracing/buffer_size_kb
> > echo nop > /sys/kernel/debug/tracing/current_tracer
> > echo 1 > /sys/kernel/tracing/events/btrfs/btrfs_space_reservation/enable
> >
> > echo 1 > /sys/kernel/debug/tracing/tracing_on
> >
> > <run the test>
> >
> > echo 0 > /sys/kernel/debug/tracing/tracing_on
> >
> > Then collect the trace to a file and send it over to me:
> >
> > cat /sys/kernel/debug/tracing/trace | xz -9 > trace.txt.xz
> >
> > And of course, the dmesg result as well.
> >
> > Thanks!
> >
> >
> >
> > >
> > > >
>