diff options
Diffstat (limited to 'include/block/block_int.h')
| -rw-r--r-- | include/block/block_int.h | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/include/block/block_int.h b/include/block/block_int.h index 5090253..3aa1e83 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -664,11 +664,15 @@ 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 +733,15 @@ 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; }; |