int ploop_di_remove_image(struct ploop_disk_images_data *di, const char *guid,
int renew_top_uuid, char **fname)
{
int snap_id, image_id, nr_ch;
struct ploop_image_data *image = NULL;
struct ploop_snapshot_data *snapshot = NULL;
snap_id = find_snapshot_by_guid(di, guid);
if (snap_id == -1) {
ploop_err(0, "Unable to find snapshot by uuid %s",
guid);
return SYSEXIT_PARAM;
}
snapshot = di->snapshots[snap_id];
image_id = find_image_idx_by_guid(di, guid);
if (image_id == -1) {
ploop_err(0, "Unable to find image by uuid %s",
guid);
return SYSEXIT_PARAM;
}
nr_ch = ploop_get_child_count_by_uuid(di, guid);
if (nr_ch != 0) {
ploop_err(0, "Unable to delete snapshot %s: "
"it has %d child%s",
guid, nr_ch,
(nr_ch == 1) ? "" : "ren");
return SYSEXIT_PARAM;
}
if (guidcmp(snapshot->parent_guid, NONE_UUID) == 0) {
ploop_err(0, "Unable to delete image %s: it is a base image",
guid);
return SYSEXIT_PARAM;
}
image = di->images[image_id];
if (fname != NULL) {
*fname = strdup(image->file);
if (*fname == NULL)
return SYSEXIT_MALLOC;
}
ploop_log(3, "del snapshot %s", guid);
// update top uuid
if (renew_top_uuid && guidcmp(guid, di->top_guid) == 0)
ploop_di_change_guid(di, snapshot->parent_guid, TOPDELTA_UUID);
remove_data_from_array((void**)di->snapshots, di->nsnapshots, snap_id);
di->nsnapshots--;
remove_data_from_array((void**)di->images, di->nimages, image_id);
di->nimages--;
free_snapshot_data(snapshot);
free_image_data(image);
return 0;
}
/* delete snapshot by guid
* 1) if guid is not active and last -> delete guid
* 2) if guid is not last merge with child -> delete child
*/
static int do_delete_snapshot(struct ploop_disk_images_data *di, const char *guid)
{
int ret;
char conf[PATH_MAX];
int nelem = 0;
char dev[64];
int snap_id;
if (is_old_snapshot_format(di))
return SYSEXIT_PARAM;
snap_id = find_snapshot_by_guid(di, guid);
if (snap_id == -1) {
ploop_err(0, "Can't find snapshot by uuid %s",
guid);
return SYSEXIT_NOSNAP;
}
ret = ploop_find_dev_by_dd(di, dev, sizeof(dev));
if (ret == -1)
return SYSEXIT_SYS;
else if (ret == 0 && strcmp(di->top_guid, guid) == 0) {
ret = SYSEXIT_PARAM;
ploop_err(0, "Unable to delete active snapshot %s",
guid);
return SYSEXIT_PARAM;
}
nelem = ploop_get_child_count_by_uuid(di, guid);
if (nelem == 0) {
struct ploop_snapshot_data *snap = di->snapshots[snap_id];
if (strcmp(snap->parent_guid, NONE_UUID) == 0) {
ploop_err(0, "Unable to delete base image");
return SYSEXIT_PARAM;
}
if (strcmp(di->top_guid, guid) == 0) {
int id = find_snapshot_by_guid(di, snap->parent_guid);
if (id == -1) {
ploop_err(0, "Can't find snapshot by uuid %s",
snap->parent_guid);
return SYSEXIT_PARAM;
}
if (di->snapshots[id]->temporary) {
ploop_err(0, "Unable to delete top delta,"
" parent snapshot is temporary");
return SYSEXIT_PARAM;
}
}
char *fname = find_image_by_guid(di, guid);
if (fname == NULL) {
ploop_err(0, "Unable to find image by uuid %s",
guid);
return SYSEXIT_PARAM;
}
ret = check_snapshot_mount(di, guid, fname, snap->temporary);
if (ret)
return ret;
fname = NULL;
/* snapshot is not active and last -> delete */
ret = ploop_di_remove_image(di, guid, 1, &fname);
if (ret)
return ret;
get_disk_descriptor_fname(di, conf, sizeof(conf));
ret = ploop_store_diskdescriptor(conf, di);
if (ret) {
free(fname);
return ret;
}
ploop_log(0, "Removing %s", fname);
if (fname != NULL && unlink(fname)) {
ploop_err(errno, "unlink %s", fname);
free(fname);
return SYSEXIT_UNLINK;
}
free(fname);
if (ret == 0)
ploop_log(0, "ploop snapshot %s has been successfully deleted",
guid);
} else if (nelem == 1) {
const char *child_guid = ploop_find_child_by_guid(di, guid);
if (child_guid == NULL) {
ploop_err(0, "Can't find child of uuid %s", guid);
return SYSEXIT_PARAM;
}
ret = ploop_merge_snapshot_by_guid(di, child_guid, NULL);
} else if (!di->snapshots[snap_id]->temporary) {
ploop_log(1, "Warning: Unable to delete snapshot %s as there are %d references"
" to it; marking it as temporary instead",
guid, nelem);
di->snapshots[snap_id]->temporary = 1;
get_disk_descriptor_fname(di, conf, sizeof(conf));
ret = ploop_store_diskdescriptor(conf, di);
}
return ret;
}
int ploop_di_merge_image(struct ploop_disk_images_data *di, const char *guid, char **fname)
{
int i, snap_id, image_id, nr_ch;
struct ploop_image_data *image = NULL;
struct ploop_snapshot_data *snapshot = NULL;
snap_id = find_snapshot_by_guid(di, guid);
if (snap_id == -1) {
ploop_err(0, "Unable to find snapshot by uuid %s",
guid);
return SYSEXIT_PARAM;
}
snapshot = di->snapshots[snap_id];
image_id = find_image_idx_by_guid(di, guid);
if (image_id == -1) {
ploop_err(0, "Unable to find image by uuid %s",
guid);
return SYSEXIT_PARAM;
}
nr_ch = ploop_get_child_count_by_uuid(di, snapshot->parent_guid);
if (nr_ch > 1) {
ploop_err(0, "Unable to merge snapshot %s: "
"it has %d children",
guid, nr_ch);
return SYSEXIT_PARAM;
}
if (guidcmp(snapshot->parent_guid, NONE_UUID) == 0) {
ploop_err(0, "Unable to merge image %s: it is a base image",
guid);
return SYSEXIT_PARAM;
}
image = di->images[image_id];
if (fname != NULL) {
*fname = strdup(image->file);
if (*fname == NULL)
return SYSEXIT_MALLOC;
}
ploop_log(3, "merge snapshot %s -> %s",
snapshot->guid, snapshot->parent_guid);
/* Caller passed child_guid S2 to delete S1 (S1 <- S2 <- S3) (S2 <- S3)
* so it has merge S2 to S1 and we should update all S1 referrences to S2
*/
for (i = 0; i < di->nsnapshots; i++) {
if (guidcmp(di->snapshots[i]->guid, snapshot->parent_guid) == 0) {
strcpy(di->snapshots[i]->guid, guid);
/* preserve temporary flag */
di->snapshots[i]->temporary = snapshot->temporary;
}
}
for (i = 0; i < di->nimages; i++)
if (guidcmp(di->images[i]->guid, snapshot->parent_guid) == 0)
strcpy(di->images[i]->guid, guid);
remove_data_from_array((void**)di->snapshots, di->nsnapshots, snap_id);
di->nsnapshots--;
remove_data_from_array((void**)di->images, di->nimages, image_id);
di->nimages--;
if (guidcmp(snapshot->guid, TOPDELTA_UUID) == 0)
ploop_di_change_guid(di, snapshot->parent_guid, TOPDELTA_UUID);
free_snapshot_data(snapshot);
free_image_data(image);
return 0;
}
