On Thu, Jun 27, 2013 at 10:41:43AM +0800, Wenchao Xia wrote:
> + /* check whether a snapshot with name exist, no need to check id, since
> + name will be checked later to make sure it does not mess up with id.
> */
> + ret = bdrv_snapshot_find_by_id_and_name(bs, NULL, name, &sn, errp);
> + if (error_is_set(errp)) {
> + return;
> + }
> + if (ret) {
> + error_setg(errp,
> + "Snapshot with name '%s' already exist on device '%s'",
s/exist/exists/
> + name, device);
> + return;
> + }
> +
> + /* Forbid having a name similar to id, empty name is also forbidden. */
> + if (!snapshot_name_wellformed(name)) {
> + error_setg(errp, "Name '%s' on device '%s' is not a valid one",
> + name, device);
> + return;
> + }
> +
> + /* 3. take the snapshot */
> + sn1 = &state->sn;
> + pstrcpy(sn1->name, sizeof(sn1->name), name);
> + qemu_gettimeofday(&tv);
> + sn1->date_sec = tv.tv_sec;
> + sn1->date_nsec = tv.tv_usec * 1000;
> + sn1->vm_clock_nsec = qemu_get_clock_ns(vm_clock);
> +
> + if (bdrv_snapshot_create(bs, sn1) < 0) {
> + error_setg(errp, "Failed to create snapshot '%s' on device '%s'",
> + name, device);
Please use error_setg_errno() to include the bdrv_snapshot_create()
error message.
> @@ -1009,6 +1010,18 @@ the new image file has the same contents as the
> current one; QEMU cannot
> perform any meaningful check. Typically this is achieved by using the
> current image file as the backing file for the new image.
>
> +On failure, the original disks pre-snapshot attempt will be used.
> +
> +For internal snapshots, the dictionary contains the device and the snapshot's
> +name. If name is a numeric string which will mess up with ID, the request
> will
This is about namespace collision. "Collide" or "conflict" are usually
used to describe identical naming problems. Instead of "mess up" I
would say something like:
The name must not be a numeric string since this collides with snapshot
IDs and an error will be returned.
> +be rejected. For example, name "99" is not a valid name. If an internal
> +snapshot matching name already exists, the request will be also rejected.
> Only
> +some image formats support it, for example, qcow2, rbd, and sheepdog.
> +
> +On failure, qemu will try delete new created internal snapshot in the
s/new created/the newly created/
> +transaction. When I/O error causes deletion failure, the user needs to fix
> it
When an I/O error occurs during deletion, ...
