[lvm-devel] [PATCH 4/8] Add dm_pool_strdup to allocate memory and copy a tag in {lv|vg}_change_tag()

[Zdenek Kabelac]

On 17.2.2010 18:29, Dave Wysochanski wrote:
> We need to allocate memory for the tag and copy the tag value before we
> add it to the list of tags.  We could put this inside lvm2app since the
> tools keep their memory around until vg_write/vg_commit is called, but
> we put it inside the internal library to minimize code in lvm2app.
> We need to copy the tag passed in by the caller to ensure the lifetime of
> the memory until the {vg|lv} handle is released.
> 
> Signed-off-by: Dave Wysochanski <dwysocha at redhat.com>
> ---
>  lib/metadata/metadata.c |   14 ++++++++++++--
>  1 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/metadata/metadata.c b/lib/metadata/metadata.c
> index 2b8a1be..2667e90 100644
> --- a/lib/metadata/metadata.c
> +++ b/lib/metadata/metadata.c
> @@ -667,6 +667,8 @@ int vg_reduce(struct volume_group *vg, char *pv_name)
>  
>  int lv_change_tag(struct logical_volume *lv, const char *tag, int add_tag)
>  {
> +	char *tag_new;
> +
>  	if (!(lv->vg->fid->fmt->features & FMT_TAGS)) {
>  		log_error("Logical volume %s/%s does not support tags",
>  			  lv->vg->name, lv->name);
> @@ -674,7 +676,10 @@ int lv_change_tag(struct logical_volume *lv, const char *tag, int add_tag)
>  	}
>  
>  	if (add_tag) {
> -		if (!str_list_add(lv->vg->vgmem, &lv->tags, tag)) {
> +		if (!(tag_new = dm_pool_strdup(lv->vg->vgmem, tag))) {
> +			return_0;
> +		}

just a tiny change here:

return_0;
prints just backtrace - however dm_pool_strdup() doesn't report allocation
failure message so a better way would be:

+log_error("tag duplication failed")
+return 0;

To remain consistent with the rest of lvm code.


Zdenek