Re: [PATCH v2 03/20] libmultipath: should_multipath: keep existing maps

["Benjamin Marzinski" <bmarzins@redhat.com>]

On Mon, Mar 19, 2018 at 04:01:38PM +0100, Martin Wilck wrote:
> with find_multipaths "yes" and without the "-n" option to multipathd,
> if a path is already multipathed, keep it. The same logic is applied by
> "multipath -u -i".
> 
> To do this, we need to add a "mpvec" parameter to should_multipath().
> 
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
> Signed-off-by: Martin Wilck <mwilck@suse.com>
> ---
>  libmultipath/configure.c |  2 +-
>  libmultipath/wwids.c     | 12 +++++++++++-
>  libmultipath/wwids.h     |  2 +-
>  multipathd/main.c        |  2 +-
>  4 files changed, 14 insertions(+), 4 deletions(-)
> 
> diff --git a/libmultipath/configure.c b/libmultipath/configure.c
> index fa6e21cb31af..16ce797c7d44 100644
> --- a/libmultipath/configure.c
> +++ b/libmultipath/configure.c
> @@ -979,7 +979,7 @@ int coalesce_paths (struct vectors * vecs, vector newmp, char * refwwid,
>  			continue;
>  
>  		/* If find_multipaths was selected check if the path is valid */
> -		if (!refwwid && !should_multipath(pp1, pathvec)) {
> +		if (!refwwid && !should_multipath(pp1, pathvec, curmp)) {
>  			orphan_path(pp1, "only one path");
>  			continue;
>  		}
> diff --git a/libmultipath/wwids.c b/libmultipath/wwids.c
> index bc70a27409d3..cb6ab52aaa5b 100644
> --- a/libmultipath/wwids.c
> +++ b/libmultipath/wwids.c
> @@ -15,6 +15,7 @@
>  #include "wwids.h"
>  #include "defaults.h"
>  #include "config.h"
> +#include "devmapper.h"
>  
>  /*
>   * Copyright (c) 2010 Benjamin Marzinski, Redhat
> @@ -271,7 +272,7 @@ out:
>  }
>  
>  int
> -should_multipath(struct path *pp1, vector pathvec)
> +should_multipath(struct path *pp1, vector pathvec, vector mpvec)
>  {
>  	int i, ignore_new_devs;
>  	struct path *pp2;
> @@ -287,6 +288,15 @@ should_multipath(struct path *pp1, vector pathvec)
>  
>  	condlog(4, "checking if %s should be multipathed", pp1->dev);
>  	if (!ignore_new_devs) {
> +		char tmp_wwid[WWID_SIZE];
> +		struct multipath *mp = find_mp_by_wwid(mpvec, pp1->wwid);
> +
> +		if (mp != NULL && dm_get_uuid(mp->alias, tmp_wwid) == 0 &&
> +		    !strncmp(tmp_wwid, pp1->wwid, WWID_SIZE)) {
> +			condlog(3, "wwid %s is already multipathed, keeping it",
> +				pp1->wwid);
> +			return 1;
> +		}
>  		vector_foreach_slot(pathvec, pp2, i) {
>  			if (pp1->dev == pp2->dev)
>  				continue;
> diff --git a/libmultipath/wwids.h b/libmultipath/wwids.h
> index 95270129daa0..d9a78b38ccf8 100644
> --- a/libmultipath/wwids.h
> +++ b/libmultipath/wwids.h
> @@ -12,7 +12,7 @@
>  "#\n" \
>  "# Valid WWIDs:\n"
>  
> -int should_multipath(struct path *pp, vector pathvec);
> +int should_multipath(struct path *pp, vector pathvec, vector mpvec);
>  int remember_wwid(char *wwid);
>  int check_wwids_file(char *wwid, int write_wwid);
>  int remove_wwid(char *wwid);
> diff --git a/multipathd/main.c b/multipathd/main.c
> index 0435133fadfb..707245c67231 100644
> --- a/multipathd/main.c
> +++ b/multipathd/main.c
> @@ -933,7 +933,7 @@ rescan:
>  		mpp->action = ACT_RELOAD;
>  		extract_hwe_from_path(mpp);
>  	} else {
> -		if (!should_multipath(pp, vecs->pathvec)) {
> +		if (!should_multipath(pp, vecs->pathvec, vecs->mpvec)) {
>  			orphan_path(pp, "only one path");
>  			return 0;
>  		}
> -- 
> 2.16.1