On Tue, Mar 06, 2018 at 12:14:56AM +0100, Martin Wilck wrote:
> This patch adds a simplified abstract interface to the multipath data
> structures.
> The idea is to allow "foreign" data structures to be treated by libmultipath
> if they implement the same interface. Currently, the intention is to use this
> only to provide formatted output about from this interface.
>
> This interface assumes only that the data structure is organized in maps
> containing path groups containing paths, and that formatted printing (using
> the wildcards defined in libmultipath) is possible on each level of the data
> structure.
>
> The patch also implements the interface for the internal dm_multipath data
> structure.
>
> The style() method looks a bit exotic, but it's necessary because
> print_multipath_topology() uses different formats depending on the mpp
> properties. This needs to be in the generic interface, too, if we want to
> produce identical output.
>
Reviewed-by: Benjamin Marzinski
> Signed-off-by: Martin Wilck
> ---
> libmultipath/Makefile | 2 +-
> libmultipath/dm-generic.c | 70
> libmultipath/dm-generic.h | 41 ++
> libmultipath/generic.c| 39 +
> libmultipath/generic.h| 136
> ++
> libmultipath/list.h | 4 ++
> libmultipath/print.c | 33 +++
> libmultipath/print.h | 12
> libmultipath/structs.c| 4 ++
> libmultipath/structs.h| 4 ++
> 10 files changed, 344 insertions(+), 1 deletion(-)
> create mode 100644 libmultipath/dm-generic.c
> create mode 100644 libmultipath/dm-generic.h
> create mode 100644 libmultipath/generic.c
> create mode 100644 libmultipath/generic.h
>
> diff --git a/libmultipath/Makefile b/libmultipath/Makefile
> index 25b052729d48..0099d9d6cc39 100644
> --- a/libmultipath/Makefile
> +++ b/libmultipath/Makefile
> @@ -43,7 +43,7 @@ OBJS = memory.o parser.o vector.o devmapper.o callout.o \
> switchgroup.o uxsock.o print.o alias.o log_pthread.o \
> log.o configure.o structs_vec.o sysfs.o prio.o checkers.o \
> lock.o waiter.o file.o wwids.o prioritizers/alua_rtpg.o prkey.o \
> - io_err_stat.o
> + io_err_stat.o dm-generic.o generic.o
>
> all: $(LIBS)
>
> diff --git a/libmultipath/dm-generic.c b/libmultipath/dm-generic.c
> new file mode 100644
> index ..42a26085d087
> --- /dev/null
> +++ b/libmultipath/dm-generic.c
> @@ -0,0 +1,70 @@
> +/*
> + Copyright (c) 2018 Martin Wilck, SUSE Linux GmbH
> +
> + This program is free software; you can redistribute it and/or
> + modify it under the terms of the GNU General Public License
> + as published by the Free Software Foundation; either version 2
> + of the License, or (at your option) any later version.
> +
> + This program is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + GNU General Public License for more details.
> +
> + You should have received a copy of the GNU General Public License
> + along with this program; if not, write to the Free Software
> + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
> + USA.
> + */
> +
> +#include
> +#include
> +#include "generic.h"
> +#include "dm-generic.h"
> +#include "structs.h"
> +#include "structs_vec.h"
> +#include "config.h"
> +#include "print.h"
> +
> +static const struct _vector*
> +dm_mp_get_pgs(const struct gen_multipath *gmp)
> +{
> + return vector_convert(NULL, gen_multipath_to_dm(gmp)->pg,
> + struct pathgroup, dm_pathgroup_to_gen);
> +}
> +
> +static void dm_mp_rel_pgs(const struct gen_multipath *gmp,
> + const struct _vector* v)
> +{
> + vector_free_const(v);
> +}
> +
> +static const struct _vector*
> +dm_pg_get_paths(const struct gen_pathgroup *gpg)
> +{
> + return vector_convert(NULL, gen_pathgroup_to_dm(gpg)->paths,
> + struct path, dm_path_to_gen);
> +}
> +
> +static void dm_mp_rel_paths(const struct gen_pathgroup *gpg,
> + const struct _vector* v)
> +{
> + vector_free_const(v);
> +}
> +
> +const struct gen_multipath_ops dm_gen_multipath_ops = {
> + .get_pathgroups = dm_mp_get_pgs,
> + .rel_pathgroups = dm_mp_rel_pgs,
> + .snprint = snprint_multipath_attr,
> + /* .style = snprint_multipath_style, TBD */
> +};
> +
> +const struct gen_pathgroup_ops dm_gen_pathgroup_ops = {
> + .get_paths = dm_pg_get_paths,
> + .rel_paths = dm_mp_rel_paths,
> + .snprint = snprint_pathgroup_attr,
> +};
> +
> +const struct gen_path_ops dm_gen_path_ops = {
> + .snprint = snprint_path_attr,
> +};
> diff --git a/libmultipath/dm-generic.h b/libmultipath/dm-generic.h
> new file mode 100644
> index ..5d5972406819
> --- /dev/null
> +++ b/libmultipath/dm-generic.h
> @@ -0,0 +1,41 @@
> +/*
