[dm-devel] [PATCH 00/54] multipath-tools series part IV: identify paths by dev_t

[Benjamin Marzinski]

On Thu, Jul 09, 2020 at 12:36:11PM +0200, mwilck at suse.com wrote:
> From: Martin Wilck <mwilck at suse.com>
> 
> Hi Christophe, hi Ben,
> 
> This is part IV of a larger patch series for multipath-tools I've been preparing.
> It's based on the previously submitted part III.
> 
> The full series will also be available here:
> https://github.com/mwilck/multipath-tools/tree/ups/submit-2007
> 
> There are tags in that repo for each part of the series.
> This part is tagged "submit-200709-4".

For the part, with the exception of patches 44 & 46
Reviewed-by: Benjamin Marzinski <bmarzins at redhat.com>
 
> The dominant idea of the patches in this subseries is to move away from
> the device node name as the main path identifier towards the dev_t aka
> major/minor number. This is motivated by the fact that dev_t is used by the
> kernel device mapper for referring to devices, both maps and paths.
> If searching a device by dev_t fails, it's basically certain not to exist.
> DM calls with major/minor number may even succeed if the respective devnode
> has not been created yet. dev_t also works better for devices that aren't
> fully initialized yet. Of course we still track the device name, but mostly
> for log messages and user-directed output.
> 
> In short, using dev_t as primary identifier makes our code more robust.
> 
> The subseries also contains some unrelated fixes for functions I worked on
> while making these changes.
> 
> Regards,
> Martin
> 
> Martin Wilck (12):
>   libmultipath: adopt_paths(): use find_path_by_devt()
>   libmultipath: adopt_paths(): don't bail out on single path failure
>   libmultipath: path_discover(): use find_path_by_devt()
>   libmultipath: path_discover(): always set DI_BLACKLIST
>   libmultipath: get_refwwid(): use find_path_by_devt()
>   libmultipath: get_refwwid(): call get_multipath_config() only once
>   libmultipath: get_refwwid(): get rid of "check" label
>   libmultipath: get_refwwid(): use symbolic return values
>   libmultipath: get_refwwid(): use switch statement
>   libmultipath: constify get_mpe_wwid()
>   multipath: call strchop() on command line argument
>   libmultipath: get_refwwid(): skip strchop(), and constify dev
>     parameter
> 
>  libmultipath/config.c      |   2 +-
>  libmultipath/config.h      |   2 +-
>  libmultipath/configure.c   | 200 +++++++++++++------------------------
>  libmultipath/configure.h   |   2 +-
>  libmultipath/discovery.c   |  32 +++---
>  libmultipath/structs_vec.c |  14 ++-
>  multipath/main.c           |   2 +
>  7 files changed, 94 insertions(+), 160 deletions(-)
> 
> -- 
> 2.26.2