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

Block layer patches:

- Introduce real BdrvChildRole
- blk/bdrv_make_empty() functions instead of calling callbacks directly
- mirror: Make sure that source and target size match
- block-copy: Fix uninitialized variable
- block/replication: Avoid cancelling the job twice
- ahci: Log lost IRQs
- iotests: Run pylint and mypy in a testcase
- iotests: log messages from notrun()

# gpg: Signature made Mon 18 May 2020 18:05:32 BST
# 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: (52 commits)
  hw: Use QEMU_IS_ALIGNED() on parallel flash block size
  iotests/030: Reduce run time by unthrottling job earlier
  hw/ide/ahci: Log lost IRQs
  iotests: log messages from notrun()
  block/block-copy: Simplify block_copy_do_copy()
  block/block-copy: Fix uninitialized variable in block_copy_task_entry
  block: Drop @child_class from bdrv_child_perm()
  block: Pass BdrvChildRole in remaining cases
  block: Drop child_file
  block: Drop bdrv_format_default_perms()
  block: Make bdrv_filter_default_perms() static
  block: Use bdrv_default_perms()
  tests: Use child_of_bds instead of child_file
  block: Use child_of_bds in remaining places
  block: Make filter drivers use child_of_bds
  block: Make format drivers use child_of_bds
  block: Drop child_backing
  block: Make backing files child_of_bds children
  block: Drop child_format
  block: Switch child_format users to child_of_bds
  ...

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

3 files changed, 92 insertions, 32 deletions

diff --git a/include/block/block.h b/include/block/block.h
index 4de8d8f8a6..25e299605e 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -13,7 +13,7 @@
 /* block.c */
 typedef struct BlockDriver BlockDriver;
 typedef struct BdrvChild BdrvChild;
-typedef struct BdrvChildRole BdrvChildRole;
+typedef struct BdrvChildClass BdrvChildClass;
 
 typedef struct BlockDriverInfo {
     /* in bytes, 0 if irrelevant */
@@ -268,6 +268,62 @@ enum {
     DEFAULT_PERM_UNCHANGED      = BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH,
 };
 
+/*
+ * Flags that parent nodes assign to child nodes to specify what kind of
+ * role(s) they take.
+ *
+ * At least one of DATA, METADATA, FILTERED, or COW must be set for
+ * every child.
+ */
+enum BdrvChildRoleBits {
+    /*
+     * This child stores data.
+     * Any node may have an arbitrary number of such children.
+     */
+    BDRV_CHILD_DATA         = (1 << 0),
+
+    /*
+     * This child stores metadata.
+     * Any node may have an arbitrary number of metadata-storing
+     * children.
+     */
+    BDRV_CHILD_METADATA     = (1 << 1),
+
+    /*
+     * A child that always presents exactly the same visible data as
+     * the parent, e.g. by virtue of the parent forwarding all reads
+     * and writes.
+     * This flag is mutually exclusive with DATA, METADATA, and COW.
+     * Any node may have at most one filtered child at a time.
+     */
+    BDRV_CHILD_FILTERED     = (1 << 2),
+
+    /*
+     * Child from which to read all data that isn’t allocated in the
+     * parent (i.e., the backing child); such data is copied to the
+     * parent through COW (and optionally COR).
+     * This field is mutually exclusive with DATA, METADATA, and
+     * FILTERED.
+     * Any node may have at most one such backing child at a time.
+     */
+    BDRV_CHILD_COW          = (1 << 3),
+
+    /*
+     * The primary child.  For most drivers, this is the child whose
+     * filename applies best to the parent node.
+     * Any node may have at most one primary child at a time.
+     */
+    BDRV_CHILD_PRIMARY      = (1 << 4),
+
+    /* Useful combination of flags */
+    BDRV_CHILD_IMAGE        = BDRV_CHILD_DATA
+                              | BDRV_CHILD_METADATA
+                              | BDRV_CHILD_PRIMARY,
+};
+
+/* Mask of BdrvChildRoleBits values */
+typedef unsigned int BdrvChildRole;
+
 char *bdrv_perm_names(uint64_t perm);
 uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm);
 
@@ -296,7 +352,8 @@ int bdrv_parse_discard_flags(const char *mode, int *flags);
 BdrvChild *bdrv_open_child(const char *filename,
                            QDict *options, const char *bdref_key,
                            BlockDriverState* parent,
-                           const BdrvChildRole *child_role,
+                           const BdrvChildClass *child_class,
+                           BdrvChildRole child_role,
                            bool allow_none, Error **errp);
 BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
 void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
@@ -352,6 +409,7 @@ BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts,
 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
 int bdrv_commit(BlockDriverState *bs);
+int bdrv_make_empty(BdrvChild *c, Error **errp);
 int bdrv_change_backing_file(BlockDriverState *bs,
     const char *backing_file, const char *backing_fmt);
 void bdrv_register(BlockDriver *bdrv);
@@ -540,7 +598,8 @@ void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
                              BlockDriverState *child_bs,
                              const char *child_name,
-                             const BdrvChildRole *child_role,
+                             const BdrvChildClass *child_class,
+                             BdrvChildRole child_role,
                              Error **errp);
 
 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 7ba8c89036..5e4f4c348c 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -96,6 +96,13 @@ struct BlockDriver {
      */
     bool is_filter;
     /*
+     * Set to true if the BlockDriver is a format driver.  Format nodes
+     * generally do not expect their children to be other format nodes
+     * (except for backing files), and so format probing is disabled
+     * on those children.
+     */
+    bool is_format;
+    /*
      * Return true if @to_replace can be replaced by a BDS with the
      * same data as @bs without it affecting @bs's behavior (that is,
      * without it being visible to @bs's parents).
@@ -549,14 +556,14 @@ struct BlockDriver {
      * the parents in @parent_perm and @parent_shared.
      *
      * If @c is NULL, return the permissions for attaching a new child for the
-     * given @role.
+     * 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
      * @reopen_queue.
      */
      void (*bdrv_child_perm)(BlockDriverState *bs, BdrvChild *c,
-                             const BdrvChildRole *role,
+                             BdrvChildRole role,
                              BlockReopenQueue *reopen_queue,
                              uint64_t parent_perm, uint64_t parent_shared,
                              uint64_t *nperm, uint64_t *nshared);
@@ -658,7 +665,7 @@ typedef struct BdrvAioNotifier {
     QLIST_ENTRY(BdrvAioNotifier) list;
 } BdrvAioNotifier;
 
-struct BdrvChildRole {
+struct BdrvChildClass {
     /* If true, bdrv_replace_node() doesn't change the node this BdrvChild
      * points to. */
     bool stay_at_node;
@@ -669,7 +676,8 @@ struct BdrvChildRole {
      * non-BDS parents. */
     bool parent_is_bds;
 
-    void (*inherit_options)(int *child_flags, QDict *child_options,
+    void (*inherit_options)(BdrvChildRole role, bool parent_is_format,
+                            int *child_flags, QDict *child_options,
                             int parent_flags, QDict *parent_options);
 
     void (*change_media)(BdrvChild *child, bool load);
@@ -731,14 +739,13 @@ struct BdrvChildRole {
     void (*set_aio_ctx)(BdrvChild *child, AioContext *ctx, GSList **ignore);
 };
 
-extern const BdrvChildRole child_file;
-extern const BdrvChildRole child_format;
-extern const BdrvChildRole child_backing;
+extern const BdrvChildClass child_of_bds;
 
 struct BdrvChild {
     BlockDriverState *bs;
     char *name;
-    const BdrvChildRole *role;
+    const BdrvChildClass *klass;
+    BdrvChildRole role;
     void *opaque;
 
     /**
@@ -765,7 +772,7 @@ struct BdrvChild {
 
     /*
      * How many times the parent of this child has been drained
-     * (through role->drained_*).
+     * (through klass->drained_*).
      * Usually, this is equal to bs->quiesce_counter (potentially
      * reduced by bdrv_drain_all_count).  It may differ while the
      * child is entering or leaving a drained section.
@@ -1225,7 +1232,8 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
 
 BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
                                   const char *child_name,
-                                  const BdrvChildRole *child_role,
+                                  const BdrvChildClass *child_class,
+                                  BdrvChildRole child_role,
                                   AioContext *ctx,
                                   uint64_t perm, uint64_t shared_perm,
                                   void *opaque, Error **errp);
@@ -1252,29 +1260,20 @@ int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
  */
 int bdrv_child_refresh_perms(BlockDriverState *bs, BdrvChild *c, Error **errp);
 
-/* Default implementation for BlockDriver.bdrv_child_perm() that can be used by
- * block filters: Forward CONSISTENT_READ, WRITE, WRITE_UNCHANGED and RESIZE to
- * all children */
-void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c,
-                               const BdrvChildRole *role,
-                               BlockReopenQueue *reopen_queue,
-                               uint64_t perm, uint64_t shared,
-                               uint64_t *nperm, uint64_t *nshared);
-
-/* Default implementation for BlockDriver.bdrv_child_perm() that can be used by
- * (non-raw) image formats: Like above for bs->backing, but for bs->file it
- * requires WRITE | RESIZE for read-write images, always requires
- * CONSISTENT_READ and doesn't share WRITE. */
-void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
-                               const BdrvChildRole *role,
-                               BlockReopenQueue *reopen_queue,
-                               uint64_t perm, uint64_t shared,
-                               uint64_t *nperm, uint64_t *nshared);
-
 bool bdrv_recurse_can_replace(BlockDriverState *bs,
                               BlockDriverState *to_replace);
 
 /*
+ * Default implementation for BlockDriver.bdrv_child_perm() that can
+ * be used by block filters and image formats, as long as they use the
+ * child_of_bds child class and set an appropriate BdrvChildRole.
+ */
+void bdrv_default_perms(BlockDriverState *bs, BdrvChild *c,
+                        BdrvChildRole role, BlockReopenQueue *reopen_queue,
+                        uint64_t perm, uint64_t shared,
+                        uint64_t *nperm, uint64_t *nshared);
+
+/*
  * Default implementation for drivers to pass bdrv_co_block_status() to
  * their file.
  */
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 0917663d89..8203d7f6f9 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -266,4 +266,6 @@ int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
 
 const BdrvChild *blk_root(BlockBackend *blk);
 
+int blk_make_empty(BlockBackend *blk, Error **errp);
+
 #endif