[lvm-devel] [PATCH 4/8] Add dm_pool_strdup to allocate memory and copy a tag in {lv|vg}_change_tag()
Dave Wysochanski
dwysocha at redhat.com
Thu Feb 18 12:17:31 UTC 2010
On Thu, 2010-02-18 at 09:55 +0100, Zdenek Kabelac wrote:
> 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;
>
Ok. Changed to:
- if (!str_list_add(lv->vg->vgmem, &lv->tags, tag)) {
+ if (!(tag_new = dm_pool_strdup(lv->vg->vgmem, tag))) {
+ log_error("Failed to duplicate tag %s from %s/%s",
+ tag, lv->vg->name, lv->name);
+ return 0;
+ }
> To remain consistent with the rest of lvm code.
>
>
> Zdenek
>
> --
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