20.11.2017 17:50, Kevin Wolf wrote:
Loading a snapshot invalidates the bitmap. Just marking all blocks dirty
is not a useful response in practice, instead the user needs to be aware
that we switch to a completely different state. If they are okay with
losing the dirty bitmap, they can just explicitly delete it.
This effectively reverts commit 04dec3c3ae5.
Signed-off-by: Kevin Wolf <[email protected]>
Reviewed-by: Vladimir Sementsov-Ogievskiy <[email protected]>
---
block/snapshot.c | 15 +++------------
1 file changed, 3 insertions(+), 12 deletions(-)
diff --git a/block/snapshot.c b/block/snapshot.c
index 13ec3b1c8c..6b338978c5 100644
--- a/block/snapshot.c
+++ b/block/snapshot.c
@@ -182,25 +182,16 @@ int bdrv_snapshot_goto(BlockDriverState *bs,
{
BlockDriver *drv = bs->drv;
int ret, open_ret;
- int64_t len;
if (!drv) {
error_setg(errp, "Block driver is closed");
return -ENOMEDIUM;
}
- len = bdrv_getlength(bs);
- if (len < 0) {
- error_setg_errno(errp, -len, "Cannot get block device size");
- return len;
+ if (!QLIST_EMPTY(&bs->dirty_bitmaps)) {
+ error_setg(errp, "Device has active dirty bitmaps");
+ return -EBUSY;
}
- /* We should set all bits in all enabled dirty bitmaps, because dirty
- * bitmaps reflect active state of disk and snapshot switch operation
- * actually dirties active state.
- * TODO: It may make sense not to set all bits but analyze block status of
- * current state and destination snapshot and do not set bits corresponding
- * to both-zero or both-unallocated areas. */
- bdrv_set_dirty(bs, 0, len);
if (drv->bdrv_snapshot_goto) {
ret = drv->bdrv_snapshot_goto(bs, snapshot_id);
--
Best regards,
Vladimir
