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-rw-r--r--include/block/block.h65
-rw-r--r--include/block/block_int.h57
-rw-r--r--include/sysemu/block-backend.h2
3 files changed, 92 insertions, 32 deletions
diff --git a/include/block/block.h b/include/block/block.h
index 4de8d8f..25e2996 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 7ba8c89..5e4f4c3 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 0917663..8203d7f 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
generated by cgit v1.1 at 2025-01-08 18:19:09 +0000