[PATCH 01/17] Add pvid parameter to create_instance function.

[Petr Rockai <prockai@redhat.com>]

Peter Rajnoha <prajnoha@redhat.com> writes:
> The format instance holds the information about current metadata areas and it
> is a snapshot of what we have in the cache at the moment of the instance
> creation. Through the command exection, we use this instance to modify, set
> and access modified metadata areas (like we use it to support the
> --metadataignore and we store the metadata areas that are in use and the
> ones that are ignored).
>
> But to support modifying metadata areas fully (with add/remove metadata
> area support), we need to be able to create format instances for PVs as well.
> Hence, add the pvid parameter for the create_instance function.

> The rules we will follow:
>
>  - the format instance is VG-based or PV-based, but *never both*
>    at the same time,
>
>  - when a PV (structure) is alone, not part of any VG, we will have
>    a PV based format_instance attached to the PV structure,
>
>  - when a PV is part of the VG, any existing PV-based format_instance
>    is destroyed and the PV strucutre will reference VG based format
>    instance instead.
>
>  - whatever we need change for mdas, we'll use the format_instance,
>    we don't touch the cache directly! This will be synchronized with the
>    format instance after pv_write automatically.

Sounds sane. Implementation looks OK too.

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

> ---
>  lib/cache/lvmcache.c          |    2 +-
>  lib/format1/format1.c         |    1 +
>  lib/format_pool/format_pool.c |    1 +
>  lib/format_text/archive.c     |    2 +-
>  lib/format_text/archiver.c    |    8 ++++----
>  lib/format_text/format-text.c |   20 +++++++++++---------
>  lib/metadata/metadata.c       |   10 +++++-----
>  lib/metadata/metadata.h       |    5 +++--
>  8 files changed, 27 insertions(+), 22 deletions(-)
>
> diff --git a/lib/cache/lvmcache.c b/lib/cache/lvmcache.c
> index 0e9cae1..476b176 100644
> --- a/lib/cache/lvmcache.c
> +++ b/lib/cache/lvmcache.c
> @@ -653,7 +653,7 @@ struct volume_group *lvmcache_get_vg(const char *vgid, unsigned precommitted)
>  		return NULL;
>  
>  	if (!(fid = vginfo->fmt->ops->create_instance(vginfo->fmt,
> -						      vginfo->vgname,
> +						      NULL, vginfo->vgname,
>  						      vgid, NULL)))
>  		return_NULL;
>  
> diff --git a/lib/format1/format1.c b/lib/format1/format1.c
> index fc14444..13b757d 100644
> --- a/lib/format1/format1.c
> +++ b/lib/format1/format1.c
> @@ -522,6 +522,7 @@ static struct metadata_area_ops _metadata_format1_ops = {
>  };
>  
>  static struct format_instance *_format1_create_instance(const struct format_type *fmt,
> +						const char *pvid __attribute__((unused)),
>  						const char *vgname __attribute__((unused)),
>  						const char *vgid __attribute__((unused)),
>  						void *private __attribute__((unused)))
> diff --git a/lib/format_pool/format_pool.c b/lib/format_pool/format_pool.c
> index 730da87..814d80c 100644
> --- a/lib/format_pool/format_pool.c
> +++ b/lib/format_pool/format_pool.c
> @@ -249,6 +249,7 @@ static struct metadata_area_ops _metadata_format_pool_ops = {
>  /* *INDENT-ON* */
>  
>  static struct format_instance *_pool_create_instance(const struct format_type *fmt,
> +						const char *pvid __attribute__((unused)),
>  						const char *vgname __attribute__((unused)),
>  						const char *vgid __attribute__((unused)),
>  						void *private __attribute__((unused)))
> diff --git a/lib/format_text/archive.c b/lib/format_text/archive.c
> index 43425dc..760153c 100644
> --- a/lib/format_text/archive.c
> +++ b/lib/format_text/archive.c
> @@ -309,7 +309,7 @@ static void _display_archive(struct cmd_context *cmd, struct archive_file *af)
>  
>  	if (!(context = create_text_context(cmd, af->path, NULL)) ||
>  	    !(tf = cmd->fmt_backup->ops->create_instance(cmd->fmt_backup, NULL,
> -							 NULL, context))) {
> +							 NULL, NULL, context))) {
>  		log_error("Couldn't create text instance object.");
>  		return;
>  	}
> diff --git a/lib/format_text/archiver.c b/lib/format_text/archiver.c
> index e0212a2..b7dcad9 100644
> --- a/lib/format_text/archiver.c
> +++ b/lib/format_text/archiver.c
> @@ -278,7 +278,7 @@ struct volume_group *backup_read_vg(struct cmd_context *cmd,
>  	if (!(context = create_text_context(cmd, file,
>  					    cmd->cmd_line)) ||
>  	    !(tf = cmd->fmt_backup->ops->create_instance(cmd->fmt_backup, NULL,
> -							 NULL, context))) {
> +							 NULL, NULL, context))) {
>  		log_error("Couldn't create text format object.");
>  		return NULL;
>  	}
> @@ -306,8 +306,8 @@ int backup_restore_vg(struct cmd_context *cmd, struct volume_group *vg)
>  	 */
>  
>  	/* Attempt to write out using currently active format */
> -	if (!(vg->fid = cmd->fmt->ops->create_instance(cmd->fmt, vg->name,
> -						       NULL, NULL))) {
> +	if (!(vg->fid = cmd->fmt->ops->create_instance(cmd->fmt, NULL,
> +						vg->name, NULL, NULL))) {
>  		log_error("Failed to allocate format instance");
>  		return 0;
>  	}
> @@ -398,7 +398,7 @@ int backup_to_file(const char *file, const char *desc, struct volume_group *vg)
>  
>  	if (!(context = create_text_context(cmd, file, desc)) ||
>  	    !(tf = cmd->fmt_backup->ops->create_instance(cmd->fmt_backup, NULL,
> -							 NULL, context))) {
> +							 NULL, NULL, context))) {
>  		log_error("Couldn't create backup object.");
>  		return 0;
>  	}
> diff --git a/lib/format_text/format-text.c b/lib/format_text/format-text.c
> index c186757..fda8255 100644
> --- a/lib/format_text/format-text.c
> +++ b/lib/format_text/format-text.c
> @@ -37,10 +37,11 @@
>  #include <dirent.h>
>  #include <ctype.h>
>  
> -static struct format_instance *_text_create_text_instance(const struct format_type
> -						     *fmt, const char *vgname,
> -						     const char *vgid,
> -						     void *context);
> +static struct format_instance *_text_create_text_instance(const struct format_type *fmt,
> +							  const char *pvid,
> +							  const char *vgname,
> +							  const char *vgid,
> +							  void *context);
>  
>  struct text_fid_context {
>  	char *raw_metadata_buf;
> @@ -1085,7 +1086,7 @@ static int _scan_file(const struct format_type *fmt, const char *vgname)
>  
>  				/* FIXME stat file to see if it's changed */
>  				fid = _text_create_text_instance(fmt, NULL, NULL,
> -							    NULL);
> +								 NULL, NULL);
>  				if ((vg = _vg_read_file_name(fid, scanned_vgname,
>  							     path))) {
>  					/* FIXME Store creation host in vg */
> @@ -1912,10 +1913,11 @@ static int _text_pv_setup(const struct format_type *fmt,
>  }
>  
>  /* 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 *vgname,
> -						     const char *vgid,
> -						     void *context)
> +static struct format_instance *_text_create_text_instance(const struct format_type*fmt,
> +							  const char *pvid,
> +							  const char *vgname,
> +							  const char *vgid,
> +							  void *context)
>  {
>  	struct format_instance *fid;
>  	struct text_fid_context *fidtc;
> diff --git a/lib/metadata/metadata.c b/lib/metadata/metadata.c
> index 771cdb0..fd1948a 100644
> --- a/lib/metadata/metadata.c
> +++ b/lib/metadata/metadata.c
> @@ -974,8 +974,8 @@ struct volume_group *vg_create(struct cmd_context *cmd, const char *vg_name)
>  	/* initialize removed_pvs list */
>  	dm_list_init(&vg->removed_pvs);
>  
> -	if (!(vg->fid = cmd->fmt->ops->create_instance(cmd->fmt, vg_name,
> -						       NULL, NULL))) {
> +	if (!(vg->fid = cmd->fmt->ops->create_instance(cmd->fmt, NULL,
> +						vg_name, NULL, NULL))) {
>  		log_error("Failed to create format instance");
>  		goto bad;
>  	}
> @@ -2629,7 +2629,7 @@ static struct volume_group *_vg_read_orphans(struct cmd_context *cmd,
>  	}
>  
>  	/* create format instance with appropriate metadata area */
> -	if (!(vg->fid = vginfo->fmt->ops->create_instance(vginfo->fmt,
> +	if (!(vg->fid = vginfo->fmt->ops->create_instance(vginfo->fmt, NULL,
>  							  orphan_vgname, NULL,
>  							  NULL))) {
>  		log_error("Failed to create format instance");
> @@ -2808,7 +2808,7 @@ static struct volume_group *_vg_read(struct cmd_context *cmd,
>  		use_precommitted = 0;
>  
>  	/* create format instance with appropriate metadata area */
> -	if (!(fid = fmt->ops->create_instance(fmt, vgname, vgid, NULL))) {
> +	if (!(fid = fmt->ops->create_instance(fmt, NULL, vgname, vgid, NULL))) {
>  		log_error("Failed to create format instance");
>  		return NULL;
>  	}
> @@ -2962,7 +2962,7 @@ static struct volume_group *_vg_read(struct cmd_context *cmd,
>  			use_precommitted = 0;
>  
>  		/* create format instance with appropriate metadata area */
> -		if (!(fid = fmt->ops->create_instance(fmt, vgname, vgid, NULL))) {
> +		if (!(fid = fmt->ops->create_instance(fmt, NULL, vgname, vgid, NULL))) {
>  			log_error("Failed to create format instance");
>  			return NULL;
>  		}
> diff --git a/lib/metadata/metadata.h b/lib/metadata/metadata.h
> index c0f9148..ab7cff0 100644
> --- a/lib/metadata/metadata.h
> +++ b/lib/metadata/metadata.h
> @@ -279,8 +279,9 @@ struct format_handler {
>  	/*
>  	 * Create format instance with a particular metadata area
>  	 */
> -	struct format_instance *(*create_instance) (const struct format_type *
> -						    fmt, const char *vgname,
> +	struct format_instance *(*create_instance) (const struct format_type *fmt,
> +						    const char *pvid,
> +						    const char *vgname,
>  						    const char *vgid,
>  						    void *context);