12.05.2018 04:25, John Snow wrote:
For the purposes of qemu-img manipulation and querying of bitmaps, load bitmaps that are "in use" -- if the image is read only. This will allow us to diagnose problems with this flag using the qemu-img tool.
It looks unsafe.. We can load them, then reopen rw and then store them on vm close, the result would be unpredictable. And they become available for qmp commands..
If we want to load them, we may need some additional state for such dirty bitmaps, something like "invalid", to be sure, that they will not be used like normal bitmap. And we may need some additional flag to load or not load them, and this behavior will be unrelated to can_write().
Signed-off-by: John Snow <js...@redhat.com> --- block/qcow2-bitmap.c | 32 +++++++++++++++----------------- 1 file changed, 15 insertions(+), 17 deletions(-) diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index fc8d52fc3e..b556dbdccd 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -346,7 +346,7 @@ static BdrvDirtyBitmap *load_bitmap(BlockDriverState *bs, uint32_t granularity; BdrvDirtyBitmap *bitmap = NULL;- if (bm->flags & BME_FLAG_IN_USE) {+ if (can_write(bs) && (bm->flags & BME_FLAG_IN_USE)) { error_setg(errp, "Bitmap '%s' is in use", bm->name); goto fail; } @@ -974,23 +974,21 @@ bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp) }QSIMPLEQ_FOREACH(bm, bm_list, entry) {- if (!(bm->flags & BME_FLAG_IN_USE)) { - BdrvDirtyBitmap *bitmap = load_bitmap(bs, bm, errp); - if (bitmap == NULL) { - goto fail; - } - bm->dirty_bitmap = bitmap; + BdrvDirtyBitmap *bitmap = load_bitmap(bs, bm, errp); + if (bitmap == NULL) { + goto fail; + } + bm->dirty_bitmap = bitmap;- if (!(bm->flags & BME_FLAG_AUTO)) {- bdrv_disable_dirty_bitmap(bitmap); - } - bdrv_dirty_bitmap_set_persistance(bitmap, true); - if (can_write(bs)) { - bm->flags |= BME_FLAG_IN_USE; - needs_update = true; - } else { - bdrv_dirty_bitmap_set_readonly(bitmap, true); - } + if (!(bm->flags & BME_FLAG_AUTO)) { + bdrv_disable_dirty_bitmap(bitmap); + } + bdrv_dirty_bitmap_set_persistance(bitmap, true); + if (can_write(bs)) { + bm->flags |= BME_FLAG_IN_USE; + needs_update = true; + } else { + bdrv_dirty_bitmap_set_readonly(bitmap, true); } }
-- Best regards, Vladimir
