[dm-devel] [PATCH 5/6] correctly set partition delimiter on rename

[Christophe Varoqui]

Ben,

I'm willing to apply this one.
Care to rebase it.

Best regards,
Christophe

On Wed, Nov 19, 2014 at 7:17 AM, Benjamin Marzinski <bmarzins at redhat.com>
wrote:

> When multipath renames a device and the name switches from ending in a
> number to ending in a letter or vice versa, it currently just keeps any
> existing delimiter between the device name and partition number.
> However the default behaviour in kpartx is to only use the 'p' delimiter
> when the name ends in a number. Unfortunately, without adding a
> kpartx.conf that kpartx uses to set the delimiter behavior, there's no
> way for multipath to know how kpartx was run for certain device names
> (ones ending in a number with a 'p' delimiter).
>
> The patch adds a new multipath.conf defaults parameter,
> "partition_delimiter". If this value is not set, when multipath renames
> a device, it will act just like the kpartx default does, only adding a
> 'p' to names ending in a number.  If this parameter is set, multipath
> will act like kpartx does with the -p option is used, and always add
> delimiter.
>
> Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
> ---
>  libmultipath/config.c    |  3 +++
>  libmultipath/config.h    |  1 +
>  libmultipath/devmapper.c | 14 ++++++++++++--
>  libmultipath/dict.c      |  4 ++++
>  4 files changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/libmultipath/config.c b/libmultipath/config.c
> index 3c72b59..701e177 100644
> --- a/libmultipath/config.c
> +++ b/libmultipath/config.c
> @@ -502,6 +502,8 @@ free_config (struct config * conf)
>
>         if (conf->alias_prefix)
>                 FREE(conf->alias_prefix);
> +       if (conf->partition_delim)
> +               FREE(conf->partition_delim);
>
>         if (conf->prio_args)
>                 FREE(conf->prio_args);
> @@ -564,6 +566,7 @@ load_config (char * file, struct udev *udev)
>         conf->detect_prio = DEFAULT_DETECT_PRIO;
>         conf->force_sync = 0;
>         conf->find_multipaths = DEFAULT_FIND_MULTIPATHS;
> +       conf->partition_delim = NULL;
>
>         /*
>          * preload default hwtable
> diff --git a/libmultipath/config.h b/libmultipath/config.h
> index 801387c..a6205ee 100644
> --- a/libmultipath/config.h
> +++ b/libmultipath/config.h
> @@ -141,6 +141,7 @@ struct config {
>         char * prio_args;
>         char * checker_name;
>         char * alias_prefix;
> +       char * partition_delim;
>         unsigned char * reservation_key;
>
>         vector keywords;
> diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
> index 3d4c111..9e585f9 100644
> --- a/libmultipath/devmapper.c
> +++ b/libmultipath/devmapper.c
> @@ -1142,6 +1142,8 @@ dm_rename_partmaps (char * old, char * new)
>         unsigned long long size;
>         char dev_t[32];
>         int r = 1;
> +       int offset;
> +       char *delim;
>
>         if (!(dmt = dm_task_create(DM_DEVICE_LIST)))
>                 return 1;
> @@ -1162,6 +1164,13 @@ dm_rename_partmaps (char * old, char * new)
>         if (dm_dev_t(old, &dev_t[0], 32))
>                 goto out;
>
> +       if (conf->partition_delim)
> +               delim = conf->partition_delim;
> +       if (isdigit(new[strlen(new)-1]))
> +               delim = "p";
> +       else
> +               delim = "";
> +
>         do {
>                 if (
>                     /*
> @@ -1189,8 +1198,9 @@ dm_rename_partmaps (char * old, char * new)
>                                  * then it's a kpartx generated partition.
>                                  * Rename it.
>                                  */
> -                               snprintf(buff, PARAMS_SIZE, "%s%s",
> -                                        new, names->name + strlen(old));
> +                               for (offset = strlen(old);
> names->name[offset] && !(isdigit(names->name[offset])); offset++); /* do
> nothing */
> +                               snprintf(buff, PARAMS_SIZE, "%s%s%s",
> +                                        new, delim, names->name + offset);
>                                 dm_rename(names->name, buff);
>                                 condlog(4, "partition map %s renamed",
>                                         names->name);
> diff --git a/libmultipath/dict.c b/libmultipath/dict.c
> index d1e2e96..f95f30c 100644
> --- a/libmultipath/dict.c
> +++ b/libmultipath/dict.c
> @@ -233,6 +233,9 @@ declare_def_snprint(multipath_dir, print_str)
>  declare_def_handler(find_multipaths, set_yes_no)
>  declare_def_snprint(find_multipaths, print_yes_no)
>
> +declare_def_handler(partition_delim, set_str)
> +declare_def_snprint(partition_delim, print_str)
> +
>  declare_def_handler(selector, set_str)
>  declare_def_snprint_defstr(selector, print_str, DEFAULT_SELECTOR)
>  declare_hw_handler(selector, set_str)
> @@ -1246,6 +1249,7 @@ init_keywords(void)
>         install_keyword("detect_prio", &def_detect_prio_handler,
> &snprint_def_detect_prio);
>         install_keyword("force_sync", &def_force_sync_handler,
> &snprint_def_force_sync);
>         install_keyword("find_multipaths", &def_find_multipaths_handler,
> &snprint_def_find_multipaths);
> +       install_keyword("partition_delimiter",
> &def_partition_delim_handler, &snprint_def_partition_delim);
>         __deprecated install_keyword("default_selector",
> &def_selector_handler, NULL);
>         __deprecated install_keyword("default_path_grouping_policy",
> &def_pgpolicy_handler, NULL);
>         __deprecated install_keyword("default_uid_attribute",
> &def_uid_attribute_handler, NULL);
> --
> 1.8.3.1
>
>
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