Re: [PATCH 0/2] New timeout while waiting for mdmon

[Kinga Tanska <kinga.tanska@linux.intel.com>]

On Mon, 6 May 2024 21:28:59 -0700
Paul E Luse <paul.e.luse@linux.intel.com> wrote:

> On Tue,  7 May 2024 05:38:54 +0200
> Kinga Stefaniuk <kinga.stefaniuk@intel.com> wrote:
> 
> > This series of patches contains adding new timeout
> > which is needed to have mdmon started completely.
> >   
> 
> Thanks Kinga!  What is the end user experience w/o this patch? (ie
> what negative impact does this patch address? mystery hang?  missing
> events?)
> 
> -Paul
> 
> > Kinga Stefaniuk (2):
> >   util.c: change devnm to const in mdmon functions
> >   Wait for mdmon when it is stared via systemd
> > 
> >  Assemble.c |  4 ++--
> >  Grow.c     |  7 ++++---
> >  mdadm.h    |  6 ++++--
> >  util.c     | 33 +++++++++++++++++++++++++++++++--
> >  4 files changed, 41 insertions(+), 9 deletions(-)
> >   
> 
> 

Hi Paul,

we have an issue for R0 - if grow is run for R0 to n-number of drives,
R0 has to move to R4, then mdmon is started for it. After that, mdadm
finishes --grow command, and systemd runs --grow-continue to have this
reshape continued for prepared array. With new kernels, we noticed that
R4 has not enough time to has mdmon started during this process, and for
this reason, the next command, --grow-continue failed.
Another problem is reboot during resync, sometimes mdmon has not
enough time to start too, and resync has been not continued after
reboot.
That's why I've proposed timeout which will address this problem.

Kinga