On Thu, Jun 18, 2020 at 09:58:35 -0500, Eric Blake wrote: > On 6/15/20 12:10 PM, Peter Krempa wrote: > > Use test data which conforms to the new semantics which changed in the > > previous patch. > > Well, a recent patch (the previous patch only touched tests, rather than > changing semantics) > > > > > The test data was created by the same set of commands as originally in > > commit 0b27b655b1bac480186ce80457113cd5dc34e6a1 > > > > Signed-off-by: Peter Krempa <pkrempa@xxxxxxxxxx> > > --- > > tests/qemublocktestdata/bitmap/snapshots.json | 1382 +++++++---------- > > tests/qemublocktestdata/bitmap/snapshots.out | 13 +- > > 2 files changed, 588 insertions(+), 807 deletions(-) > > > +++ b/tests/qemublocktestdata/bitmap/snapshots.out > > @@ -1,12 +1,17 @@ > > libvirt-1-format: > > - d: record:0 busy:0 persist:1 inconsist:0 gran:65536 dirty:0 > > + d: record:1 busy:0 persist:1 inconsist:0 gran:65536 dirty:0 > > + a: record:1 busy:0 persist:1 inconsist:0 gran:65536 dirty:0 > > + b: record:1 busy:0 persist:1 inconsist:0 gran:65536 dirty:0 > > + c: record:1 busy:0 persist:1 inconsist:0 gran:65536 dirty:0 > > current: record:1 busy:0 persist:1 inconsist:0 gran:65536 dirty:0 > > So, where the old paradigm stitched bitmaps across snapshots (no need to add > a bitmap to a new snapshot layer if it was already inactive in the old > layer), the new paradigm says that every reachable checkpoint must have an > active bitmap in the current layer, in addition to whatever bitmaps it had > in earlier layers. > > Presumably, upcoming patches will tweak libvirt to actually create these > bitmaps as part of creating an external snapshot, and I also see how you > could utilize qemu adding block-dirty-bitmap-populate as a convenient way > for re-creating such bitmaps after the fact (any bitmap that exists in the > backing chain should basically mirror the allocation of the current layer in > the chain). They are actually already being created by 'qemuDomainSnapshotDiskBitmapsPropagate', and that code is still valid. But I've noticed that the comment needs to be fixed probably.
