On 21.02.2017 15:58, Kevin Wolf wrote: > Most filters need permissions related to read and write for their > children, but only if the node has a parent that wants to use the same > operation on the filter. The same is true for resize. > > This adds a default implementation that simply forwards all necessary > permissions to all children of the node and leaves the other permissions > unchanged. > > Signed-off-by: Kevin Wolf <[email protected]> > --- > block.c | 24 ++++++++++++++++++++++++ > include/block/block_int.h | 8 ++++++++ > 2 files changed, 32 insertions(+) > > diff --git a/block.c b/block.c > index 2a86781..523cbd3 100644 > --- a/block.c > +++ b/block.c > @@ -1531,6 +1531,30 @@ int bdrv_child_try_set_perm(BdrvChild *c, uint64_t > perm, uint64_t shared, > return 0; > } > > +#define DEFAULT_PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \ > + | BLK_PERM_WRITE \ > + | BLK_PERM_WRITE_UNCHANGED \ > + | BLK_PERM_RESIZE) > +#define DEFAULT_PERM_UNCHANGED (BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH) > + > +void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c, > + const BdrvChildRole *role, > + uint64_t perm, uint64_t shared, > + uint64_t *nperm, uint64_t *nshared) > +{ > + if (c == NULL) { > + *nperm = 0; > + *nshared = BLK_PERM_ALL;
On second thought, I don't understand this. Why isn't this
*nperm = perm & DEFAULT_PERM_PASSTHROUGH;
*nshared = shared & DEFAULT_PERM_PASSTHROUGH;
?
Max
> + return;
> + }
> +
> + *nperm = (perm & DEFAULT_PERM_PASSTHROUGH) |
> + (c->perm & DEFAULT_PERM_UNCHANGED);
> + *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) |
> + (c->shared_perm & DEFAULT_PERM_UNCHANGED);
> +}
> +
> +
> static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs)
> {
> BlockDriverState *old_bs = child->bs;
signature.asc
Description: OpenPGP digital signature
