block: Pass BdrvChildRole to bdrv_child_perm()

For now, all callers pass 0 and no callee evaluates this value.  Later
patches will change both.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-7-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block.c b/block.c
index 14810e0..5d9a331 100644
--- a/block.c
+++ b/block.c
@@ -1954,12 +1954,12 @@
 
 static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs,
                             BdrvChild *c, const BdrvChildClass *child_class,
-                            BlockReopenQueue *reopen_queue,
+                            BdrvChildRole role, BlockReopenQueue *reopen_queue,
                             uint64_t parent_perm, uint64_t parent_shared,
                             uint64_t *nperm, uint64_t *nshared)
 {
     assert(bs->drv && bs->drv->bdrv_child_perm);
-    bs->drv->bdrv_child_perm(bs, c, child_class, reopen_queue,
+    bs->drv->bdrv_child_perm(bs, c, child_class, role, reopen_queue,
                              parent_perm, parent_shared,
                              nperm, nshared);
     /* TODO Take force_share from reopen_queue */
@@ -2053,7 +2053,7 @@
         uint64_t cur_perm, cur_shared;
         bool child_tighten_restr;
 
-        bdrv_child_perm(bs, c->bs, c, c->klass, q,
+        bdrv_child_perm(bs, c->bs, c, c->klass, c->role, q,
                         cumulative_perms, cumulative_shared_perms,
                         &cur_perm, &cur_shared);
         ret = bdrv_child_check_perm(c, q, cur_perm, cur_shared, ignore_children,
@@ -2120,7 +2120,7 @@
     /* Update all children */
     QLIST_FOREACH(c, &bs->children, next) {
         uint64_t cur_perm, cur_shared;
-        bdrv_child_perm(bs, c->bs, c, c->klass, NULL,
+        bdrv_child_perm(bs, c->bs, c, c->klass, c->role, NULL,
                         cumulative_perms, cumulative_shared_perms,
                         &cur_perm, &cur_shared);
         bdrv_child_set_perm(c, cur_perm, cur_shared);
@@ -2348,14 +2348,15 @@
     uint64_t perms, shared;
 
     bdrv_get_cumulative_perm(bs, &parent_perms, &parent_shared);
-    bdrv_child_perm(bs, c->bs, c, c->klass, NULL, parent_perms, parent_shared,
-                    &perms, &shared);
+    bdrv_child_perm(bs, c->bs, c, c->klass, c->role, NULL,
+                    parent_perms, parent_shared, &perms, &shared);
 
     return bdrv_child_try_set_perm(c, perms, shared, errp);
 }
 
 void bdrv_filter_default_perms(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)
@@ -2366,6 +2367,7 @@
 
 void bdrv_format_default_perms(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)
@@ -2378,7 +2380,7 @@
 
         /* Apart from the modifications below, the same permissions are
          * forwarded and left alone as for filters */
-        bdrv_filter_default_perms(bs, c, child_class, reopen_queue,
+        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 */
@@ -2655,7 +2657,7 @@
     bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm);
 
     assert(parent_bs->drv);
-    bdrv_child_perm(parent_bs, child_bs, NULL, child_class, NULL,
+    bdrv_child_perm(parent_bs, child_bs, NULL, child_class, child_role, NULL,
                     perm, shared_perm, &perm, &shared_perm);
 
     child = bdrv_root_attach_child(child_bs, child_name, child_class,
@@ -3683,7 +3685,7 @@
         if (state->replace_backing_bs && state->new_backing_bs) {
             uint64_t nperm, nshared;
             bdrv_child_perm(state->bs, state->new_backing_bs,
-                            NULL, &child_backing, bs_queue,
+                            NULL, &child_backing, 0, bs_queue,
                             state->perm, state->shared_perm,
                             &nperm, &nshared);
             ret = bdrv_check_update_perm(state->new_backing_bs, NULL,
@@ -3806,7 +3808,7 @@
         } else {
             uint64_t nperm, nshared;
 
-            bdrv_child_perm(parent->state.bs, bs, c, c->klass, q,
+            bdrv_child_perm(parent->state.bs, bs, c, c->klass, c->role, q,
                             parent->state.perm, parent->state.shared_perm,
                             &nperm, &nshared);
 
diff --git a/block/backup-top.c b/block/backup-top.c
index f891dd7..e2b4d2a 100644
--- a/block/backup-top.c
+++ b/block/backup-top.c
@@ -123,6 +123,7 @@
 
 static void backup_top_child_perm(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)
@@ -155,7 +156,7 @@
         *nperm = BLK_PERM_WRITE;
     } else {
         /* Source child */
-        bdrv_filter_default_perms(bs, c, child_class, reopen_queue,
+        bdrv_filter_default_perms(bs, c, child_class, role, reopen_queue,
                                   perm, shared, nperm, nshared);
 
         if (perm & BLK_PERM_WRITE) {
diff --git a/block/blkdebug.c b/block/blkdebug.c
index c91e78d..8dd8ed6 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -994,14 +994,15 @@
 
 static void blkdebug_child_perm(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)
 {
     BDRVBlkdebugState *s = bs->opaque;
 
-    bdrv_filter_default_perms(bs, c, child_class, reopen_queue, perm, shared,
-                              nperm, nshared);
+    bdrv_filter_default_perms(bs, c, child_class, role, reopen_queue,
+                              perm, shared, nperm, nshared);
 
     *nperm |= s->take_child_perms;
     *nshared &= ~s->unshare_child_perms;
diff --git a/block/blklogwrites.c b/block/blklogwrites.c
index 739db6d..4faf912 100644
--- a/block/blklogwrites.c
+++ b/block/blklogwrites.c
@@ -283,6 +283,7 @@
 
 static void blk_log_writes_child_perm(BlockDriverState *bs, BdrvChild *c,
                                       const BdrvChildClass *child_class,
+                                      BdrvChildRole role,
                                       BlockReopenQueue *ro_q,
                                       uint64_t perm, uint64_t shrd,
                                       uint64_t *nperm, uint64_t *nshrd)
@@ -294,11 +295,11 @@
     }
 
     if (!strcmp(c->name, "log")) {
-        bdrv_format_default_perms(bs, c, child_class, ro_q, perm, shrd, nperm,
-                                  nshrd);
+        bdrv_format_default_perms(bs, c, child_class, role, ro_q, perm, shrd,
+                                  nperm, nshrd);
     } else {
-        bdrv_filter_default_perms(bs, c, child_class, ro_q, perm, shrd, nperm,
-                                  nshrd);
+        bdrv_filter_default_perms(bs, c, child_class, role, ro_q, perm, shrd,
+                                  nperm, nshrd);
     }
 }
 
diff --git a/block/commit.c b/block/commit.c
index 834eeae..6af1c80 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -224,6 +224,7 @@
 
 static void bdrv_commit_top_child_perm(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)
diff --git a/block/copy-on-read.c b/block/copy-on-read.c
index a2c4e6d..a2d92ac 100644
--- a/block/copy-on-read.c
+++ b/block/copy-on-read.c
@@ -52,6 +52,7 @@
 
 static void cor_child_perm(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)
diff --git a/block/mirror.c b/block/mirror.c
index d659846..cb4bdad 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1493,6 +1493,7 @@
 
 static void bdrv_mirror_top_child_perm(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)
diff --git a/block/quorum.c b/block/quorum.c
index 024de76..d37b77a 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -1152,6 +1152,7 @@
 
 static void quorum_child_perm(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)
diff --git a/block/replication.c b/block/replication.c
index 052c7ef..ea87b1a 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -164,6 +164,7 @@
 
 static void replication_child_perm(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)
diff --git a/block/vvfat.c b/block/vvfat.c
index cd8ae50..6cf3c74 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -3211,6 +3211,7 @@
 
 static void vvfat_child_perm(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)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 1c6641c..dc4bc48 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -556,7 +556,7 @@
      * the parents in @parent_perm and @parent_shared.
      *
      * If @c is NULL, return the permissions for attaching a new child for the
-     * given @child_class.
+     * given @child_class and @role.
      *
      * If @reopen_queue is non-NULL, don't return the currently needed
      * permissions, but those that will be needed after applying the
@@ -564,6 +564,7 @@
      */
      void (*bdrv_child_perm)(BlockDriverState *bs, BdrvChild *c,
                              const BdrvChildClass *child_class,
+                             BdrvChildRole role,
                              BlockReopenQueue *reopen_queue,
                              uint64_t parent_perm, uint64_t parent_shared,
                              uint64_t *nperm, uint64_t *nshared);
@@ -1266,6 +1267,7 @@
  * all children */
 void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c,
                                const BdrvChildClass *child_class,
+                               BdrvChildRole child_role,
                                BlockReopenQueue *reopen_queue,
                                uint64_t perm, uint64_t shared,
                                uint64_t *nperm, uint64_t *nshared);
@@ -1276,6 +1278,7 @@
  * CONSISTENT_READ and doesn't share WRITE. */
 void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
                                const BdrvChildClass *child_class,
+                               BdrvChildRole child_role,
                                BlockReopenQueue *reopen_queue,
                                uint64_t perm, uint64_t shared,
                                uint64_t *nperm, uint64_t *nshared);
diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index c03705e..b3d7960 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -87,6 +87,7 @@
 
 static void bdrv_test_child_perm(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)
@@ -99,8 +100,8 @@
         child_class = &child_file;
     }
 
-    bdrv_format_default_perms(bs, c, child_class, reopen_queue, perm, shared,
-                              nperm, nshared);
+    bdrv_format_default_perms(bs, c, child_class, role, reopen_queue,
+                              perm, shared, nperm, nshared);
 }
 
 static int bdrv_test_change_backing_file(BlockDriverState *bs,
diff --git a/tests/test-bdrv-graph-mod.c b/tests/test-bdrv-graph-mod.c
index 8b8c186..3707e25 100644
--- a/tests/test-bdrv-graph-mod.c
+++ b/tests/test-bdrv-graph-mod.c
@@ -31,6 +31,7 @@
 
 static void no_perm_default_perms(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)