OpenE2K/qemu-e2k
13
4
Fork 0
Code Issues 4 Pull Requests Projects 2 Releases Activity

qcow2: Use intermediate helper CB for amend

Browse Source 
If there is more than one time-consuming operation to be performed for
qcow2_amend_options(), we need an intermediate CB which coordinates the
progress of the individual operations and passes the result to the
original status callback.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Max Reitz 2015-07-27 17:51:36 +02:00 committed by Kevin Wolf
parent 1038bbb803
commit c293a80927
1 changed files with 79 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

80
block/qcow2.c
View File

@ -2933,6 +2933,75 @@ static int qcow2_downgrade(BlockDriverState *bs, int target_version,
return 0;
}
typedef enum Qcow2AmendOperation {
/* This is the value Qcow2AmendHelperCBInfo::last_operation will be
* statically initialized to so that the helper CB can discern the first
* invocation from an operation change */
QCOW2_NO_OPERATION = 0,
QCOW2_DOWNGRADING,
} Qcow2AmendOperation;
typedef struct Qcow2AmendHelperCBInfo {
/* The code coordinating the amend operations should only modify
* these four fields; the rest will be managed by the CB */
BlockDriverAmendStatusCB *original_status_cb;
void *original_cb_opaque;
Qcow2AmendOperation current_operation;
/* Total number of operations to perform (only set once) */
int total_operations;
/* The following fields are managed by the CB */
/* Number of operations completed */
int operations_completed;
/* Cumulative offset of all completed operations */
int64_t offset_completed;
Qcow2AmendOperation last_operation;
int64_t last_work_size;
} Qcow2AmendHelperCBInfo;
static void qcow2_amend_helper_cb(BlockDriverState *bs,
int64_t operation_offset,
int64_t operation_work_size, void *opaque)
{
Qcow2AmendHelperCBInfo *info = opaque;
int64_t current_work_size;
int64_t projected_work_size;
if (info->current_operation != info->last_operation) {
if (info->last_operation != QCOW2_NO_OPERATION) {
info->offset_completed += info->last_work_size;
info->operations_completed++;
}
info->last_operation = info->current_operation;
}
assert(info->total_operations > 0);
assert(info->operations_completed < info->total_operations);
info->last_work_size = operation_work_size;
current_work_size = info->offset_completed + operation_work_size;
/* current_work_size is the total work size for (operations_completed + 1)
* operations (which includes this one), so multiply it by the number of
* operations not covered and divide it by the number of operations
* covered to get a projection for the operations not covered */
projected_work_size = current_work_size * (info->total_operations -
info->operations_completed - 1)
/ (info->operations_completed + 1);
info->original_status_cb(bs, info->offset_completed + operation_offset,
current_work_size + projected_work_size,
info->original_cb_opaque);
}
static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
BlockDriverAmendStatusCB *status_cb,
void *cb_opaque)
@ -2947,6 +3016,7 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
bool encrypt;
int ret;
QemuOptDesc *desc = opts->list->desc;
Qcow2AmendHelperCBInfo helper_cb_info;
while (desc && desc->name) {
if (!qemu_opt_find(opts, desc->name)) {
@ -3006,6 +3076,12 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
desc++;
}
helper_cb_info = (Qcow2AmendHelperCBInfo){
.original_status_cb = status_cb,
.original_cb_opaque = cb_opaque,
.total_operations = (new_version < old_version)
};
/* Upgrade first (some features may require compat=1.1) */
if (new_version > old_version) {
s->qcow_version = new_version;
@ -3065,7 +3141,9 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
/* Downgrade last (so unsupported features can be removed before) */
if (new_version < old_version) {
ret = qcow2_downgrade(bs, new_version, status_cb, cb_opaque);
helper_cb_info.current_operation = QCOW2_DOWNGRADING;
ret = qcow2_downgrade(bs, new_version, &qcow2_amend_helper_cb,
&helper_cb_info);
if (ret < 0) {
return ret;
}