On Mon, 02/29 18:00, John Snow wrote:
>
>
> On 02/27/2016 04:20 AM, Fam Zheng wrote:
> > The added group of operations enables tracking of the changed bits in
> > the dirty bitmap.
> >
> > Signed-off-by: Fam Zheng <f...@redhat.com>
> > ---
> > block/dirty-bitmap.c | 51
> > ++++++++++++++++++++++++++++++++++++++++++++
> > include/block/dirty-bitmap.h | 9 ++++++++
> > 2 files changed, 60 insertions(+)
> >
> > diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
> > index 16f73b2..5f19320 100644
> > --- a/block/dirty-bitmap.c
> > +++ b/block/dirty-bitmap.c
> > @@ -38,6 +38,7 @@
> > */
> > struct BdrvDirtyBitmap {
> > HBitmap *bitmap; /* Dirty sector bitmap implementation */
> > + HBitmap *meta; /* Meta dirty bitmap */
> > BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status
> > */
> > char *name; /* Optional non-empty unique ID */
> > int64_t size; /* Size of the bitmap (Number of sectors)
> > */
> > @@ -103,6 +104,56 @@ BdrvDirtyBitmap
> > *bdrv_create_dirty_bitmap(BlockDriverState *bs,
> > return bitmap;
> > }
> >
> > +/* bdrv_create_meta_dirty_bitmap
> > + *
> > + * Create a meta dirty bitmap that tracks the changes of bits in @bitmap.
> > I.e.
> > + * when a dirty status bit in @bitmap is changed (either from reset to set
> > or
> > + * the other way around), its respective meta dirty bitmap bit will be
> > marked
> > + * dirty as well.
> > + *
> > + * @bitmap: the block dirty bitmap for which to create a meta dirty bitmap.
> > + * @chunk_size: how many bytes of bitmap data does each bit in the meta
> > bitmap
> > + * track.
> > + */
> > +void bdrv_create_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap,
> > + int chunk_size)
> > +{
> > + assert(!bitmap->meta);
> > + bitmap->meta = hbitmap_create_meta(bitmap->bitmap,
> > + chunk_size * BITS_PER_BYTE);
> > +}
> > +
> > +void bdrv_release_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap)
> > +{
> > + assert(bitmap->meta);
> > + hbitmap_free_meta(bitmap->bitmap);
> > + bitmap->meta = NULL;
> > +}
> > +
> > +int bdrv_dirty_bitmap_get_meta(BlockDriverState *bs,
> > + BdrvDirtyBitmap *bitmap, int64_t sector,
> > + int nb_sectors)
> > +{
> > + uint64_t i;
> > + int gran = bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS;
> > +
> > + /* To optimize: we can make hbitmap to internally check the range in a
> > + * coarse level, or at least do it word by word. */
> > + for (i = sector; i < sector + nb_sectors; i += gran) {
> > + if (hbitmap_get(bitmap->meta, i)) {
> > + return true;
> > + }
> > + }
> > + return false;
> > +}
> > +
> > +void bdrv_dirty_bitmap_reset_meta(BlockDriverState *bs,
> > + BdrvDirtyBitmap *bitmap, int64_t sector,
> > + int nb_sectors)
> > +{
> > + hbitmap_reset(bitmap->meta, sector, nb_sectors);
> > +}
> > +
> > bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap)
> > {
> > return bitmap->successor;
> > diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
> > index e1dbd8e..3b27742 100644
> > --- a/include/block/dirty-bitmap.h
> > +++ b/include/block/dirty-bitmap.h
> > @@ -9,6 +9,9 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState
> > *bs,
> > uint32_t granularity,
> > const char *name,
> > Error **errp);
> > +void bdrv_create_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap,
> > + int chunk_size);
> > +void bdrv_release_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap);
> > int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs,
> > BdrvDirtyBitmap *bitmap,
> > Error **errp);
> > @@ -37,6 +40,12 @@ void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
> > int64_t cur_sector, int nr_sectors);
> > void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
> > int64_t cur_sector, int nr_sectors);
> > +int bdrv_dirty_bitmap_get_meta(BlockDriverState *bs,
> > + BdrvDirtyBitmap *bitmap, int64_t sector,
> > + int nb_sectors);
> > +void bdrv_dirty_bitmap_reset_meta(BlockDriverState *bs,
> > + BdrvDirtyBitmap *bitmap, int64_t sector,
> > + int nb_sectors);
> > BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap,
> > uint64_t first_sector);
> > void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter);
> >
>
> Do we need to amend the teardown in bdrv_do_release_matching_dirty_bitmap?
Will add an "assert(!bm->meta)" there.
Fam
