Message ID | 20170412174920.8744-5-eblake@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
On 04/12/2017 01:49 PM, Eric Blake wrote: > We are still using an internal hbitmap that tracks a size in sectors, > with the granularity scaled down accordingly, because it lets us > use a shortcut for our iterators which are currently sector-based. > But there's no reason we can't track the dirty bitmap size in bytes, > since it is an internal-only variable. > > Signed-off-by: Eric Blake <eblake@redhat.com> > --- > block/dirty-bitmap.c | 23 +++++++++++++---------- > 1 file changed, 13 insertions(+), 10 deletions(-) > > diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c > index 32698d5..a413df1 100644 > --- a/block/dirty-bitmap.c > +++ b/block/dirty-bitmap.c > @@ -41,7 +41,7 @@ struct BdrvDirtyBitmap { > 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) */ > + int64_t size; /* Size of the bitmap, in bytes */ > bool disabled; /* Bitmap is read-only */ > int active_iterators; /* How many iterators are active */ > QLIST_ENTRY(BdrvDirtyBitmap) list; > @@ -79,24 +79,26 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, > { > int64_t bitmap_size; > BdrvDirtyBitmap *bitmap; > - uint32_t sector_granularity; > > - assert((granularity & (granularity - 1)) == 0); > + assert(is_power_of_2(granularity) && granularity >= BDRV_SECTOR_SIZE); > > if (name && bdrv_find_dirty_bitmap(bs, name)) { > error_setg(errp, "Bitmap already exists: %s", name); > return NULL; > } > - sector_granularity = granularity >> BDRV_SECTOR_BITS; > - assert(sector_granularity); > - bitmap_size = bdrv_nb_sectors(bs); > + bitmap_size = bdrv_getlength(bs); > if (bitmap_size < 0) { > error_setg_errno(errp, -bitmap_size, "could not get length of device"); > errno = -bitmap_size; > return NULL; > } > bitmap = g_new0(BdrvDirtyBitmap, 1); > - bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(sector_granularity)); > + /* > + * TODO - let hbitmap track full granularity. For now, it is tracking > + * only sector granularity, as a shortcut for our iterators. > + */ > + bitmap->bitmap = hbitmap_alloc(bitmap_size >> BDRV_SECTOR_BITS, > + ctz32(granularity) - BDRV_SECTOR_BITS); > bitmap->size = bitmap_size; > bitmap->name = g_strdup(name); > bitmap->disabled = false; > @@ -246,12 +248,13 @@ BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs, > void bdrv_dirty_bitmap_truncate(BlockDriverState *bs) > { > BdrvDirtyBitmap *bitmap; > - uint64_t size = bdrv_nb_sectors(bs); > + int64_t size = bdrv_getlength(bs); > > + assert(size >= 0); > QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { > assert(!bdrv_dirty_bitmap_frozen(bitmap)); > assert(!bitmap->active_iterators); > - hbitmap_truncate(bitmap->bitmap, size); > + hbitmap_truncate(bitmap->bitmap, size >> BDRV_SECTOR_BITS); > bitmap->size = size; > } > } > @@ -419,7 +422,7 @@ void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out) > hbitmap_reset_all(bitmap->bitmap); > } else { > HBitmap *backup = bitmap->bitmap; > - bitmap->bitmap = hbitmap_alloc(bitmap->size, > + bitmap->bitmap = hbitmap_alloc(bitmap->size >> BDRV_SECTOR_BITS, > hbitmap_granularity(backup)); > *out = backup; > } > Reviewed-by: John Snow <jsnow@redhat.com>
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c index 32698d5..a413df1 100644 --- a/block/dirty-bitmap.c +++ b/block/dirty-bitmap.c @@ -41,7 +41,7 @@ struct BdrvDirtyBitmap { 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) */ + int64_t size; /* Size of the bitmap, in bytes */ bool disabled; /* Bitmap is read-only */ int active_iterators; /* How many iterators are active */ QLIST_ENTRY(BdrvDirtyBitmap) list; @@ -79,24 +79,26 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, { int64_t bitmap_size; BdrvDirtyBitmap *bitmap; - uint32_t sector_granularity; - assert((granularity & (granularity - 1)) == 0); + assert(is_power_of_2(granularity) && granularity >= BDRV_SECTOR_SIZE); if (name && bdrv_find_dirty_bitmap(bs, name)) { error_setg(errp, "Bitmap already exists: %s", name); return NULL; } - sector_granularity = granularity >> BDRV_SECTOR_BITS; - assert(sector_granularity); - bitmap_size = bdrv_nb_sectors(bs); + bitmap_size = bdrv_getlength(bs); if (bitmap_size < 0) { error_setg_errno(errp, -bitmap_size, "could not get length of device"); errno = -bitmap_size; return NULL; } bitmap = g_new0(BdrvDirtyBitmap, 1); - bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(sector_granularity)); + /* + * TODO - let hbitmap track full granularity. For now, it is tracking + * only sector granularity, as a shortcut for our iterators. + */ + bitmap->bitmap = hbitmap_alloc(bitmap_size >> BDRV_SECTOR_BITS, + ctz32(granularity) - BDRV_SECTOR_BITS); bitmap->size = bitmap_size; bitmap->name = g_strdup(name); bitmap->disabled = false; @@ -246,12 +248,13 @@ BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs, void bdrv_dirty_bitmap_truncate(BlockDriverState *bs) { BdrvDirtyBitmap *bitmap; - uint64_t size = bdrv_nb_sectors(bs); + int64_t size = bdrv_getlength(bs); + assert(size >= 0); QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { assert(!bdrv_dirty_bitmap_frozen(bitmap)); assert(!bitmap->active_iterators); - hbitmap_truncate(bitmap->bitmap, size); + hbitmap_truncate(bitmap->bitmap, size >> BDRV_SECTOR_BITS); bitmap->size = size; } } @@ -419,7 +422,7 @@ void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out) hbitmap_reset_all(bitmap->bitmap); } else { HBitmap *backup = bitmap->bitmap; - bitmap->bitmap = hbitmap_alloc(bitmap->size, + bitmap->bitmap = hbitmap_alloc(bitmap->size >> BDRV_SECTOR_BITS, hbitmap_granularity(backup)); *out = backup; }
We are still using an internal hbitmap that tracks a size in sectors, with the granularity scaled down accordingly, because it lets us use a shortcut for our iterators which are currently sector-based. But there's no reason we can't track the dirty bitmap size in bytes, since it is an internal-only variable. Signed-off-by: Eric Blake <eblake@redhat.com> --- block/dirty-bitmap.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-)