[PATCH 08/17] Add pv_remove_metadata_area fn to support removing metadata areas on demand.

[Petr Rockai <prockai@redhat.com>]

Peter Rajnoha <prajnoha@redhat.com> writes:

> The same as for pv_add_metadata_area, but removing...
These look OK (although the FMT_TEXT_MAX_MDAS_PER_PV is a bit fiddly).

> Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Reviewed-by: Petr Rockai <prockai@redhat.com>

> ---
>  lib/format_text/format-text.c |   24 ++++++++++++++++++++++++
>  lib/format_text/format-text.h |    2 ++
>  lib/metadata/metadata.h       |    7 +++++++
>  3 files changed, 33 insertions(+), 0 deletions(-)
>
> diff --git a/lib/format_text/format-text.c b/lib/format_text/format-text.c
> index cf18f25..99f691f 100644
> --- a/lib/format_text/format-text.c
> +++ b/lib/format_text/format-text.c
> @@ -2275,6 +2275,29 @@ bad:
>  	return 0;
>  }
>  
> +int remove_metadata_area_from_pv(struct physical_volume *pv,
> +				 unsigned mda_index)
> +{
> +	if (mda_index >= FMT_TEXT_MAX_MDAS_PER_PV) {
> +		log_error(INTERNAL_ERROR "can't remove metadata area with "
> +					 "index %u from PV %s. Metadata "
> +					 "layou not supported by %s format.",
> +					  mda_index, dev_name(pv->dev),
> +					  pv->fmt->name);
> +		return 0;
> +	}
> +
> +	return fid_remove_mda(pv->fid, NULL, (const char *) &pv->id,
> +			      ID_LEN, mda_index);
> +}
> +
> +static int _text_pv_remove_metadata_area(const struct format_type *fmt,
> +					 struct physical_volume *pv,
> +					 unsigned mda_index)
> +{
> +	return remove_metadata_area_from_pv(pv, mda_index);
> +}
> +
>  /* NULL vgname means use only the supplied context e.g. an archive file */
>  static struct format_instance *_text_create_text_instance(const struct format_type *fmt,
>  							  const char *pvid,
> @@ -2356,6 +2379,7 @@ static struct format_handler _text_handler = {
>  	.pv_read = _text_pv_read,
>  	.pv_setup = _text_pv_setup,
>  	.pv_add_metadata_area = _text_pv_add_metadata_area,
> +	.pv_remove_metadata_area = _text_pv_remove_metadata_area,
>  	.pv_write = _text_pv_write,
>  	.vg_setup = _text_vg_setup,
>  	.lv_setup = _text_lv_setup,
> diff --git a/lib/format_text/format-text.h b/lib/format_text/format-text.h
> index f65be74..694b5c1 100644
> --- a/lib/format_text/format-text.h
> +++ b/lib/format_text/format-text.h
> @@ -61,6 +61,8 @@ int add_metadata_area_to_pv(struct physical_volume *pv,
>  			    uint64_t mda_start,
>  			    uint64_t mda_size,
>  			    unsigned mda_ignored);
> +int remove_metadata_area_from_pv(struct physical_volume *pv,
> +				 unsigned mda_index);
>  int add_mda(const struct format_type *fmt, struct dm_pool *mem, struct dm_list *mdas,
>  	    struct device *dev, uint64_t start, uint64_t size, unsigned ignored);
>  void del_mdas(struct dm_list *mdas);
> diff --git a/lib/metadata/metadata.h b/lib/metadata/metadata.h
> index 0da8b3d..ed72551 100644
> --- a/lib/metadata/metadata.h
> +++ b/lib/metadata/metadata.h
> @@ -266,6 +266,13 @@ struct format_handler {
>  				     unsigned metadata_ignored);
>  
>  	/*
> +	 * Remove metadata area from a PV. Changes will take effect on pv_write.
> +	 */
> +	int (*pv_remove_metadata_area) (const struct format_type *fmt,
> +					struct physical_volume *pv,
> +					unsigned metadata_index);
> +
> +	/*
>  	 * Write a PV structure to disk. Fails if the PV is in a VG ie
>  	 * pv->vg_name must be a valid orphan VG name
>  	 */