[dm-devel] [PATCH 0/3] multipath: fixes for SAS expanders and root FS access

[Benjamin Marzinski]

On Thu, Jan 28, 2021 at 09:45:41PM +0100, mwilck at suse.com wrote:
> From: Martin Wilck <mwilck at suse.com>
> 
> Hi Christophe, hi Ben,
> 
> here are 3 patches I'd like to get reviewed before we create a pull
> request. The first two are related to complex SAS setups, the second
> one is to avoid accessing the root file system in a possible dangerous
> situation.
> 
> Wrt 2/3: while testing it, I discovered that "I_T_nexus_loss_timeout"
> is a read-only sysfs attribute, therefore this code does nothing.
> I considered removing it altogether, observing that the attribute has
> been read-only as long as it existed (v2.6.17, 2006). I'd like some
> feedback beforehand, though, perhaps some distros use patched kernels
> that make this attribute r/w?

I_T_nexus_loss_timeout appears to have always been read-only on RHEL and
Fedora.

-Ben

> 
> Regards
> Martin
> 
> Martin Wilck (3):
>   libmultipath: use 3rd digit as transport_id for expanders
>   libmultipath: sysfs_set_nexus_loss_tmo(): support SAS expanders
>   multipathd: add code to initalize unwinder
> 
>  libmultipath/discovery.c   | 35 ++++++++++++++++++++++++++++-------
>  multipathd/Makefile        |  2 +-
>  multipathd/init_unwinder.c | 34 ++++++++++++++++++++++++++++++++++
>  multipathd/init_unwinder.h | 21 +++++++++++++++++++++
>  multipathd/main.c          |  2 ++
>  5 files changed, 86 insertions(+), 8 deletions(-)
>  create mode 100644 multipathd/init_unwinder.c
>  create mode 100644 multipathd/init_unwinder.h
> 
> -- 
> 2.29.2