Include qemu/main-loop.h less

[qemu.git] / include / block / block_int.h

diff --git a/include/block/block_int.h b/include/block/block_int.h
index a498c2670b3d2cee3929fbfc241ffb89b84cd3d1..6207a105ff40d698e60b2ab792e55c2e226d4088 100644 (file)
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -33,7 +33,6 @@
 #include "qemu/timer.h"
 #include "qemu/hbitmap.h"
 #include "block/snapshot.h"
-#include "qemu/main-loop.h"
 #include "qemu/throttle.h"
 
 #define BLOCK_FLAG_LAZY_REFCOUNTS   8
@@ -664,11 +663,15 @@ struct BdrvChildRole {
      * These functions must not change the graph (and therefore also must not
      * call aio_poll(), which could change the graph indirectly).
      *
+     * If drained_end() schedules background operations, it must atomically
+     * increment *drained_end_counter for each such operation and atomically
+     * decrement it once the operation has settled.
+     *
      * Note that this can be nested. If drained_begin() was called twice, new
      * I/O is allowed only after drained_end() was called twice, too.
      */
     void (*drained_begin)(BdrvChild *child);
-    void (*drained_end)(BdrvChild *child);
+    void (*drained_end)(BdrvChild *child, int *drained_end_counter);
 
     /*
      * Returns whether the parent has pending requests for the child. This
@@ -729,6 +732,15 @@ struct BdrvChild {
      */
     bool frozen;
 
+    /*
+     * How many times the parent of this child has been drained
+     * (through role->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.
+     */
+    int parent_quiesce_counter;
+
     QLIST_ENTRY(BdrvChild) next;
     QLIST_ENTRY(BdrvChild) next_parent;
 };
@@ -885,6 +897,9 @@ struct BlockDriverState {
 
     /* Only read/written by whoever has set active_flush_req to true.  */
     unsigned int flushed_gen;             /* Flushed write generation */
+
+    /* BdrvChild links to this node may never be frozen */
+    bool never_freeze;
 };
 
 struct BlockBackendRootState {
@@ -1165,9 +1180,24 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
                                   void *opaque, Error **errp);
 void bdrv_root_unref_child(BdrvChild *child);
 
+/**
+ * Sets a BdrvChild's permissions.  Avoid if the parent is a BDS; use
+ * bdrv_child_refresh_perms() instead and make the parent's
+ * .bdrv_child_perm() implementation return the correct values.
+ */
 int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
                             Error **errp);
 
+/**
+ * Calls bs->drv->bdrv_child_perm() and updates the child's permission
+ * masks with the result.
+ * Drivers should invoke this function whenever an event occurs that
+ * makes their .bdrv_child_perm() implementation return different
+ * values than before, but which will not result in the block layer
+ * automatically refreshing the permissions.
+ */
+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 */