9:13 a.m.
Changes since V4:
- Split out BlockPull() and BlockPullAll().
- BlockPull() cursor changed to a virDomainBlockPullInfo for progress
reporting only (from in/out to out-only parameter).
/* An iterator for initiating and monitoring block pull operations */
typedef unsigned long long virDomainBlockPullCursor;
typedef struct _virDomainBlockPullInfo virDomainBlockPullInfo;
struct _virDomainBlockPullInfo {
/*
* The following fields provide an indication of block pull progress. @cur
* indicates the current position and will be between 0 and @end. @end is
* the final cursor position for this operation and represents completion.
* To approximate progress, divide @cur by @end.
*/
virDomainBlockPullCursor cur;
virDomainBlockPullCursor end;
};
typedef virDomainBlockPullInfo *virDomainBlockPullInfoPtr;
/**
* virDomainBlockPull:
* @dom: pointer to domain object
* @path: Fully-qualified filename of disk
* @pos: A pointer to a virDomainBlockPullInfo structure, or NULL
* @flags: currently unused, for future extension
*
* Populate a disk image with data from its backing image. Once all data from
* its backing image has been pulled, the disk no longer depends on a backing
* image. This function works incrementally, performing a small amount of work
* each time it is called. When successful, @pos is updated with the current
* progress.
*
* Returns -1 in case of failure, 0 when successful.
*/
int virDomainBlockPull(virDomainPtr dom,
const char *path,
virDomainBlockPullInfoPtr *pos,
unsigned int flags);
/**
* virDomainBlockPullAll:
* @dom: pointer to domain object
* @path: Fully-qualified filename of disk
* @flags: currently unused, for future extension
*
* Populate a disk image with data from its backing image. Once all data from
* its backing image has been pulled, the disk no longer depends on a backing
* image. This function pulls data for the entire device in the background.
* Progress of the operation can be checked with virDomainGetBlockPullInfo() and
* the operation can be aborted with virDomainBlockPullAbort(). When finished,
* an asynchronous event is raised to indicate the final status.
*
* Returns 0 if the operation has started, -1 on failure.
*/
int virDomainBlockPullAll(virDomainPtr dom,
const char *path,
unsigned int flags);
/**
* virDomainBlockPullAbort:
* @dom: pointer to domain object
* @path: fully-qualified filename of disk
* @flags: currently unused, for future extension
*
* Cancel a pull operation previously started by virDomainBlockPullAll().
*
* Returns -1 in case of failure, 0 when successful.
*/
int virDomainBlockPullAbort(virDomainPtr dom,
const char *path,
unsigned int flags);
/**
* virDomainGetBlockPullInfo:
* @dom: pointer to domain object
* @path: fully-qualified filename of disk
* @info: pointer to a virDomainBlockPullInfo structure
* @flags: currently unused, for future extension
*
* Request progress information on a block pull operation that has been started
* with virDomainBlockPullAll(). If an operation is active for the given
* parameters, @info will be updated with the current progress.
*
* Returns -1 in case of failure, 0 when successful.
*/
int virDomainGetBlockPullInfo(virDomainPtr dom,
const char *path,
virDomainBlockStreamInfoPtr info,
unsigned int flags);
The following new asynchronous event will be made available for subscription:
VIR_DOMAIN_EVENT_ID_BLOCK_PULL = 7,
typedef enum {
VIR_DOMAIN_BLOCK_PULL_COMPLETED,
VIR_DOMAIN_BLOCK_PULL_FAILED,
} virConnectDomainEventBlockPullStatus;
typedef void (*virConnectDomainEventBlockPullCallback(virConnectPtr conn,
virDomainPtr dom,
const char *path,
int status);
Upon receipt of this event and when the status field indicates success, libvirt
will revoke access to the backing file which is no longer needed by the domain.
NOTE: Qemu will emit an asynchronous event (VIR_DOMAIN_BLOCK_PULL_COMPLETED)
after any operation that eliminates the dependency on the backing file. This
will allow libvirt to manage backing file security. If the operation failed,
an event (VIR_DOMAIN_BLOCK_PULL_FAILED) will indicate that the backing file has
not been removed.
--
Adam Litke
IBM Linux Technology Center