Re: [PATCH v3] ceph: defer flushing the capsnap if the Fb is used

[Jeff Layton <jlayton@kernel.org>]

On Mon, 2021-01-18 at 17:10 +0800, Xiubo Li wrote:
> On 2021/1/13 5:48, Jeff Layton wrote:
> > On Sun, 2021-01-10 at 10:01 +0800, xiubli@redhat.com wrote:
> > > From: Xiubo Li <xiubli@redhat.com>
> > > 
> > > If the Fb cap is used it means the current inode is flushing the
> > > dirty data to OSD, just defer flushing the capsnap.
> > > 
> > > URL: https://tracker.ceph.com/issues/48679
> > > URL: https://tracker.ceph.com/issues/48640
> > > Signed-off-by: Xiubo Li <xiubli@redhat.com>
> > > ---
> > > 
> > > V3:
> > > - Add more comments about putting the inode ref
> > > - A small change about the code style
> > > 
> > > V2:
> > > - Fix inode reference leak bug
> > > 
> > >   fs/ceph/caps.c | 32 +++++++++++++++++++-------------
> > >   fs/ceph/snap.c |  6 +++---
> > >   2 files changed, 22 insertions(+), 16 deletions(-)
> > > 
> > Hi Xiubo,
> > 
> > This patch seems to cause hangs in some xfstests (generic/013, in
> > particular). I'll take a closer look when I have a chance, but I'm
> > dropping this for now.
> 
> Okay.
> 
> BTW, what's your test commands to reproduce it ? I will take a look when 
> I am free these days or later.
> 
> BRs
> 

I set up xfstests to run on cephfs, and then just run:

    $ sudo ./check generic/013

It wouldn't reliably complete with this patch in place. Setting up
xfstests is the "hard part". I'll plan to roll up a wiki page on how to
do that soon (that's good info to have out there anyway).
> 

Cheers,
-- 
Jeff Layton <jlayton@kernel.org>