On 11/13/2017 10:20 AM, Vladimir Sementsov-Ogievskiy wrote: > Like other setters here these functions should take a lock. > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> > --- > block/dirty-bitmap.c | 4 ++++ > 1 file changed, 4 insertions(+)
Should this patch be in 2.11?
>
> diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
> index bd04e991b1..2a0bcd9e51 100644
> --- a/block/dirty-bitmap.c
> +++ b/block/dirty-bitmap.c
> @@ -397,15 +397,19 @@ void
> bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs,
> /* Called with BQL taken. */
> void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
> {
> + bdrv_dirty_bitmap_lock(bitmap);
> assert(!bdrv_dirty_bitmap_frozen(bitmap));
> bitmap->disabled = true;
> + bdrv_dirty_bitmap_unlock(bitmap);
Why do we need this lock in addition to BQL?
> }
>
> /* Called with BQL taken. */
> void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
> {
> + bdrv_dirty_bitmap_lock(bitmap);
> assert(!bdrv_dirty_bitmap_frozen(bitmap));
> bitmap->disabled = false;
> + bdrv_dirty_bitmap_unlock(bitmap);
Again, why do we need this in addition to BQL?
The commit message needs more details about a scenario where our
existing BQL lock is insufficient to prevent misuse of bitmap->disabled.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
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