Clarify first two cases and fix Modify -> Any access in third case.
Also, drop 'only' from third case, as it a bit confuses, when thinking
about case where we modify BdrvDirtyBitmap and access HBitmap.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
---
include/block/block_int.h | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index c4dd1d4bb8..189666efa5 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -709,10 +709,14 @@ struct BlockDriverState {
uint64_t write_threshold_offset;
NotifierWithReturn write_threshold_notifier;
- /* Writing to the list requires the BQL _and_ the dirty_bitmap_mutex.
- * Reading from the list can be done with either the BQL or the
- * dirty_bitmap_mutex. Modifying a bitmap only requires
- * dirty_bitmap_mutex. */
+ /* Writing to the list (i.e. to any field of BdrvDirtyBitmap or to the
+ * list-head) requires both the BQL _and_ the dirty_bitmap_mutex.
+ *
+ * Reading from the list (from any field of BdrvDirtyBitmap or from the
+ * list-head) can be done with either the BQL or the dirty_bitmap_mutex.
+ *
+ * Any access to underlying HBitmap requires dirty_bitmap_mutex.
+ */
QemuMutex dirty_bitmap_mutex;
QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
--
2.11.1
