/*
* Normal snapshot or thinly-provisioned snapshot?
*/
static int _determine_snapshot_type(struct volume_group *vg,
struct lvcreate_params *lp)
{
struct lv_list *lvl;
if (!(lvl = find_lv_in_vg(vg, lp->origin))) {
log_error("Snapshot origin LV %s not found in Volume group %s.",
lp->origin, vg->name);
return 0;
}
if (!arg_count(vg->cmd, extents_ARG) && !arg_count(vg->cmd, size_ARG)) {
if (!lv_is_thin_volume(lvl->lv)) {
log_error("Please specify either size or extents with snapshots.");
return 0;
}
lp->thin = 1;
if (!(lp->segtype = get_segtype_from_string(vg->cmd, "thin")))
return_0;
lp->pool = first_seg(lvl->lv)->pool_lv->name;
}
return 1;
}
static percent_t _data_percent(const struct logical_volume *lv)
{
percent_t perc;
if (lv_is_cow(lv))
return _snap_percent(lv);
if (lv_is_thin_volume(lv))
return lv_thin_percent(lv, 0, &perc) ? perc : PERCENT_INVALID;
return lv_thin_pool_percent(lv, 0, &perc) ? perc : PERCENT_INVALID;
}
/* Check if given LV is usable as snapshot origin LV */
int validate_snapshot_origin(const struct logical_volume *origin_lv)
{
const char *err = NULL; /* For error string */
if (lv_is_cow(origin_lv))
err = "snapshots";
else if (lv_is_locked(origin_lv))
err = "locked volumes";
else if (lv_is_pvmove(origin_lv))
err = "pvmoved volumes";
else if (!lv_is_visible(origin_lv))
err = "hidden volumes";
else if (lv_is_merging_origin(origin_lv))
err = "an origin that has a merging snapshot";
else if (lv_is_cache_type(origin_lv) && !lv_is_cache(origin_lv))
err = "cache type volumes";
else if (lv_is_thin_type(origin_lv) && !lv_is_thin_volume(origin_lv))
err = "thin pool type volumes";
else if (lv_is_mirror_type(origin_lv)) {
if (!lv_is_mirror(origin_lv))
err = "mirror subvolumes";
else {
log_warn("WARNING: Snapshots of mirrors can deadlock under rare device failures.");
log_warn("WARNING: Consider using the raid1 mirror type to avoid this.");
log_warn("WARNING: See global/mirror_segtype_default in lvm.conf.");
}
} else if (lv_is_raid_type(origin_lv) && !lv_is_raid(origin_lv))
err = "raid subvolumes";
if (err) {
log_error("Snapshots of %s are not supported.", err);
return 0;
}
if (vg_is_clustered(origin_lv->vg) && lv_is_active(origin_lv) &&
!lv_is_active_exclusive_locally(origin_lv)) {
log_error("Snapshot origin must be active exclusively.");
return 0;
}
return 1;
}
static dm_percent_t _data_percent(const struct logical_volume *lv)
{
dm_percent_t percent;
struct lv_status_cache *status;
if (lv_is_cow(lv))
return _snap_percent(lv);
if (lv_is_cache(lv) || lv_is_cache_pool(lv)) {
if (!lv_cache_status(lv, &status)) {
stack;
return DM_PERCENT_INVALID;
}
percent = status->dirty_usage;
dm_pool_destroy(status->mem);
return percent;
}
if (lv_is_thin_volume(lv))
return lv_thin_percent(lv, 0, &percent) ? percent : DM_PERCENT_INVALID;
return lv_thin_pool_percent(lv, 0, &percent) ? percent : DM_PERCENT_INVALID;
}
int lv_is_cow(const struct logical_volume *lv)
{
/* Make sure a merging thin origin isn't confused as a cow LV */
return (!lv_is_thin_volume(lv) && !lv_is_origin(lv) && lv->snapshot) ? 1 : 0;
}