Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- Fix crash on write to read-only devices
- iotests: Rewrite 'check' in Python, get rid of 'groups' and allow
  non-numeric test case names

# gpg: Signature made Wed 27 Jan 2021 19:56:00 GMT
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  iotests: rename and move 169 and 199 tests
  iotests: rewrite check into python
  iotests: add testrunner.py
  iotests: add testenv.py
  iotests: add findtests.py
  iotests: 146: drop extra whitespaces from .out file
  virtio-scsi-test: Test writing to scsi-cd device
  block: Separate blk_is_writable() and blk_supports_write_perm()

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 16 insertions, 3 deletions

diff --git a/block/block-backend.c b/block/block-backend.c
index ce78d30794..e493f17515 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1826,17 +1826,30 @@ void blk_error_action(BlockBackend *blk, BlockErrorAction action,
     }
 }
 
-bool blk_is_read_only(BlockBackend *blk)
+/*
+ * Returns true if the BlockBackend can support taking write permissions
+ * (because its root node is not read-only).
+ */
+bool blk_supports_write_perm(BlockBackend *blk)
 {
     BlockDriverState *bs = blk_bs(blk);
 
     if (bs) {
-        return bdrv_is_read_only(bs);
+        return !bdrv_is_read_only(bs);
     } else {
-        return blk->root_state.read_only;
+        return !blk->root_state.read_only;
     }
 }
 
+/*
+ * Returns true if the BlockBackend can be written to in its current
+ * configuration (i.e. if write permission have been requested)
+ */
+bool blk_is_writable(BlockBackend *blk)
+{
+    return blk->perm & BLK_PERM_WRITE;
+}
+
 bool blk_is_sg(BlockBackend *blk)
 {
     BlockDriverState *bs = blk_bs(blk);