Am 18.09.2017 um 09:37 hat Fam Zheng geschrieben:
> On Fri, 09/15 12:10, Kevin Wolf wrote:
> > If we switch between read-only and read-write, the permissions that
> > image format drivers need on bs->file change, too. Make sure to update
> > the permissions during bdrv_reopen().
> >
> > Signed-off-by: Kevin Wolf <kw...@redhat.com>
> > ---
> > include/block/block.h | 1 +
> > block.c | 64
> > +++++++++++++++++++++++++++++++++++++++++++++++++++
> > 2 files changed, 65 insertions(+)
> >
> > diff --git a/include/block/block.h b/include/block/block.h
> > index 082eb2cd9c..3c3af462e4 100644
> > --- a/include/block/block.h
> > +++ b/include/block/block.h
> > @@ -166,6 +166,7 @@ typedef QSIMPLEQ_HEAD(BlockReopenQueue,
> > BlockReopenQueueEntry) BlockReopenQueue;
> > typedef struct BDRVReopenState {
> > BlockDriverState *bs;
> > int flags;
> > + uint64_t perm, shared_perm;
> > QDict *options;
> > QDict *explicit_options;
> > void *opaque;
> > diff --git a/block.c b/block.c
> > index 204cbb46c7..5c65fac672 100644
> > --- a/block.c
> > +++ b/block.c
> > @@ -2781,6 +2781,10 @@ static BlockReopenQueue
> > *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
> > bs_entry->state.explicit_options = explicit_options;
> > bs_entry->state.flags = flags;
> >
> > + /* This needs to be overwritten in bdrv_reopen_prepare() */
> > + bs_entry->state.perm = UINT64_MAX;
>
> Probably doesn't matter because as the comment says it will be overwritten
> soon,
> but is BLK_PERM_ALL more appropriate?
I had BLK_PERM_ALL at first, but after debugging some assertion failures
in gdb, I came to the conclusion that UINT64_MAX is easier to identify as
uninitialised than BLK_PERM_ALL, which could be a valid result of the
permission calculation.
Kevin
