Right now, bdrv_format_default_perms() is used by format parents
(generally). We want to switch to a model where most parents use a
single BdrvChildClass, which then decides the permissions based on the
child role. To do so, we have to split bdrv_format_default_perms() into
separate functions for each such role.
Note that bdrv_default_perms_for_storage() currently handles all DATA |
METADATA children. A follow-up patch is going to split it further into
one function for each case.
Signed-off-by: Max Reitz <mre...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
---
block.c | 71 +++++++++++++++++++++++++++++++++++++--------------------
1 file changed, 46 insertions(+), 25 deletions(-)
diff --git a/block.c b/block.c
index 8b97412cbc..64b5635122 100644
--- a/block.c
+++ b/block.c
@@ -2340,6 +2340,50 @@ static void
bdrv_default_perms_for_backing(BlockDriverState *bs, BdrvChild *c,
*nshared = shared;
}
+static void bdrv_default_perms_for_storage(BlockDriverState *bs, BdrvChild *c,
+ const BdrvChildClass *child_class,
+ BdrvChildRole role,
+ BlockReopenQueue *reopen_queue,
+ uint64_t perm, uint64_t shared,
+ uint64_t *nperm, uint64_t *nshared)
+{
+ int flags;
+
+ assert(child_class == &child_file ||
+ (child_class == &child_of_bds &&
+ (role & (BDRV_CHILD_METADATA | BDRV_CHILD_DATA))));
+
+ flags = bdrv_reopen_get_flags(reopen_queue, bs);
+
+ /*
+ * Apart from the modifications below, the same permissions are
+ * forwarded and left alone as for filters
+ */
+ bdrv_filter_default_perms(bs, c, child_class, role, reopen_queue,
+ perm, shared, &perm, &shared);
+
+ /* Format drivers may touch metadata even if the guest doesn't write */
+ if (bdrv_is_writable_after_reopen(bs, reopen_queue)) {
+ perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
+ }
+
+ /*
+ * bs->file always needs to be consistent because of the metadata. We
+ * can never allow other users to resize or write to it.
+ */
+ if (!(flags & BDRV_O_NO_IO)) {
+ perm |= BLK_PERM_CONSISTENT_READ;
+ }
+ shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE);
+
+ if (bs->open_flags & BDRV_O_INACTIVE) {
+ shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
+ }
+
+ *nperm = perm;
+ *nshared = shared;
+}
+
void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
const BdrvChildClass *child_class,
BdrvChildRole role,
@@ -2351,31 +2395,8 @@ void bdrv_format_default_perms(BlockDriverState *bs,
BdrvChild *c,
assert(child_class == &child_backing || child_class == &child_file);
if (!backing) {
- int flags = bdrv_reopen_get_flags(reopen_queue, bs);
-
- /* Apart from the modifications below, the same permissions are
- * forwarded and left alone as for filters */
- bdrv_filter_default_perms(bs, c, child_class, role, reopen_queue,
- perm, shared, &perm, &shared);
-
- /* Format drivers may touch metadata even if the guest doesn't write */
- if (bdrv_is_writable_after_reopen(bs, reopen_queue)) {
- perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
- }
-
- /* bs->file always needs to be consistent because of the metadata. We
- * can never allow other users to resize or write to it. */
- if (!(flags & BDRV_O_NO_IO)) {
- perm |= BLK_PERM_CONSISTENT_READ;
- }
- shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE);
-
- if (bs->open_flags & BDRV_O_INACTIVE) {
- shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
- }
-
- *nperm = perm;
- *nshared = shared;
+ bdrv_default_perms_for_storage(bs, c, child_class, role, reopen_queue,
+ perm, shared, nperm, nshared);
} else {
bdrv_default_perms_for_backing(bs, c, child_class, role, reopen_queue,
perm, shared, nperm, nshared);
--
2.24.1
