snapshot: distinguish id and name in load_tmp

Since later this function will be used so improve it. The only caller of it
now is qemu-img, and it is not impacted by introduce function
bdrv_snapshot_load_tmp_by_id_or_name() that call bdrv_snapshot_load_tmp()
twice to keep old search logic. bdrv_snapshot_load_tmp_by_id_or_name() return
int to let caller know the errno, and errno will be used later.
Also fix a typo in comments of bdrv_snapshot_delete().

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
master
Wenchao Xia 2013-12-04 17:10:54 +08:00 committed by Stefan Hajnoczi
parent 34602dd642
commit 7b4c4781e3
6 changed files with 83 additions and 10 deletions

View File

@ -675,7 +675,10 @@ int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
return s->nb_snapshots;
}
int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name)
int qcow2_snapshot_load_tmp(BlockDriverState *bs,
const char *snapshot_id,
const char *name,
Error **errp)
{
int i, snapshot_index;
BDRVQcowState *s = bs->opaque;
@ -687,8 +690,10 @@ int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name)
assert(bs->read_only);
/* Search the snapshot */
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_name);
snapshot_index = find_snapshot_by_id_and_name(bs, snapshot_id, name);
if (snapshot_index < 0) {
error_setg(errp,
"Can't find snapshot");
return -ENOENT;
}
sn = &s->snapshots[snapshot_index];
@ -699,6 +704,7 @@ int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name)
ret = bdrv_pread(bs->file, sn->l1_table_offset, new_l1_table, new_l1_bytes);
if (ret < 0) {
error_setg(errp, "Failed to read l1 table for snapshot");
g_free(new_l1_table);
return ret;
}

View File

@ -488,7 +488,10 @@ int qcow2_snapshot_delete(BlockDriverState *bs,
const char *name,
Error **errp);
int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name);
int qcow2_snapshot_load_tmp(BlockDriverState *bs,
const char *snapshot_id,
const char *name,
Error **errp);
void qcow2_free_snapshots(BlockDriverState *bs);
int qcow2_read_snapshots(BlockDriverState *bs);

View File

@ -194,7 +194,7 @@ int bdrv_snapshot_goto(BlockDriverState *bs,
* If only @snapshot_id is specified, delete the first one with id
* @snapshot_id.
* If only @name is specified, delete the first one with name @name.
* if none is specified, return -ENINVAL.
* if none is specified, return -EINVAL.
*
* Returns: 0 on success, -errno on failure. If @bs is not inserted, return
* -ENOMEDIUM. If @snapshot_id and @name are both NULL, return -EINVAL. If @bs
@ -265,18 +265,71 @@ int bdrv_snapshot_list(BlockDriverState *bs,
return -ENOTSUP;
}
/**
* Temporarily load an internal snapshot by @snapshot_id and @name.
* @bs: block device used in the operation
* @snapshot_id: unique snapshot ID, or NULL
* @name: snapshot name, or NULL
* @errp: location to store error
*
* If both @snapshot_id and @name are specified, load the first one with
* id @snapshot_id and name @name.
* If only @snapshot_id is specified, load the first one with id
* @snapshot_id.
* If only @name is specified, load the first one with name @name.
* if none is specified, return -EINVAL.
*
* Returns: 0 on success, -errno on fail. If @bs is not inserted, return
* -ENOMEDIUM. If @bs is not readonly, return -EINVAL. If @bs did not support
* internal snapshot, return -ENOTSUP. If qemu can't find a matching @id and
* @name, return -ENOENT. If @errp != NULL, it will always be filled on
* failure.
*/
int bdrv_snapshot_load_tmp(BlockDriverState *bs,
const char *snapshot_name)
const char *snapshot_id,
const char *name,
Error **errp)
{
BlockDriver *drv = bs->drv;
if (!drv) {
error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs));
return -ENOMEDIUM;
}
if (!snapshot_id && !name) {
error_setg(errp, "snapshot_id and name are both NULL");
return -EINVAL;
}
if (!bs->read_only) {
error_setg(errp, "Device is not readonly");
return -EINVAL;
}
if (drv->bdrv_snapshot_load_tmp) {
return drv->bdrv_snapshot_load_tmp(bs, snapshot_name);
return drv->bdrv_snapshot_load_tmp(bs, snapshot_id, name, errp);
}
error_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
drv->format_name, bdrv_get_device_name(bs),
"temporarily load internal snapshot");
return -ENOTSUP;
}
int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
const char *id_or_name,
Error **errp)
{
int ret;
Error *local_err = NULL;
ret = bdrv_snapshot_load_tmp(bs, id_or_name, NULL, &local_err);
if (ret == -ENOENT || ret == -EINVAL) {
error_free(local_err);
local_err = NULL;
ret = bdrv_snapshot_load_tmp(bs, NULL, id_or_name, &local_err);
}
if (error_is_set(&local_err)) {
error_propagate(errp, local_err);
}
return ret;
}

View File

@ -176,7 +176,9 @@ struct BlockDriver {
int (*bdrv_snapshot_list)(BlockDriverState *bs,
QEMUSnapshotInfo **psn_info);
int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
const char *snapshot_name);
const char *snapshot_id,
const char *name,
Error **errp);
int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);

View File

@ -61,5 +61,10 @@ void bdrv_snapshot_delete_by_id_or_name(BlockDriverState *bs,
int bdrv_snapshot_list(BlockDriverState *bs,
QEMUSnapshotInfo **psn_info);
int bdrv_snapshot_load_tmp(BlockDriverState *bs,
const char *snapshot_name);
const char *snapshot_id,
const char *name,
Error **errp);
int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
const char *id_or_name,
Error **errp);
#endif

View File

@ -1264,8 +1264,12 @@ static int img_convert(int argc, char **argv)
ret = -1;
goto out;
}
if (bdrv_snapshot_load_tmp(bs[0], snapshot_name) < 0) {
error_report("Failed to load snapshot");
bdrv_snapshot_load_tmp_by_id_or_name(bs[0], snapshot_name, &local_err);
if (error_is_set(&local_err)) {
error_report("Failed to load snapshot: %s",
error_get_pretty(local_err));
error_free(local_err);
ret = -1;
goto out;
}