1 files changed, 40 insertions, 21 deletions

diff --git a/include/block/block_int.h b/include/block/block_int.h
index cb78c4fa82..748970055e 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -29,6 +29,7 @@
 #include "qemu/option.h"
 #include "qemu/queue.h"
 #include "qemu/coroutine.h"
+#include "qemu/stats64.h"
 #include "qemu/timer.h"
 #include "qapi-types.h"
 #include "qemu/hbitmap.h"
@@ -595,11 +596,6 @@ struct BlockDriverState {
 
     /* Protected by AioContext lock */
 
-    /* If true, copy read backing sectors into image.  Can be >1 if more
-     * than one client has requested copy-on-read.
-     */
-    int copy_on_read;
-
     /* If we are reading a disk image, give its size in sectors.
      * Generally read-only; it is written to by load_snapshot and
      * save_snaphost, but the block layer is quiescent during those.
@@ -609,34 +605,57 @@ struct BlockDriverState {
     /* Callback before write request is processed */
     NotifierWithReturnList before_write_notifiers;
 
-    /* number of in-flight requests; overall and serialising */
-    unsigned int in_flight;
-    unsigned int serialising_in_flight;
+    /* threshold limit for writes, in bytes. "High water mark". */
+    uint64_t write_threshold_offset;
+    NotifierWithReturn write_threshold_notifier;
 
-    bool wakeup;
+    /* 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.  */
+    QemuMutex dirty_bitmap_mutex;
+    QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
 
     /* Offset after the highest byte written to */
-    uint64_t wr_highest_offset;
+    Stat64 wr_highest_offset;
 
-    /* threshold limit for writes, in bytes. "High water mark". */
-    uint64_t write_threshold_offset;
-    NotifierWithReturn write_threshold_notifier;
+    /* If true, copy read backing sectors into image.  Can be >1 if more
+     * than one client has requested copy-on-read.  Accessed with atomic
+     * ops.
+     */
+    int copy_on_read;
 
-    /* counter for nested bdrv_io_plug */
-    unsigned io_plugged;
+    /* number of in-flight requests; overall and serialising.
+     * Accessed with atomic ops.
+     */
+    unsigned int in_flight;
+    unsigned int serialising_in_flight;
 
-    QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
-    CoQueue flush_queue;                  /* Serializing flush queue */
-    bool active_flush_req;                /* Flush request in flight? */
-    unsigned int write_gen;               /* Current data generation */
-    unsigned int flushed_gen;             /* Flushed write generation */
+    /* Internal to BDRV_POLL_WHILE and bdrv_wakeup.  Accessed with atomic
+     * ops.
+     */
+    bool wakeup;
 
-    QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
+    /* counter for nested bdrv_io_plug.
+     * Accessed with atomic ops.
+    */
+    unsigned io_plugged;
 
     /* do we need to tell the quest if we have a volatile write cache? */
     int enable_write_cache;
 
+    /* Accessed with atomic ops.  */
     int quiesce_counter;
+    unsigned int write_gen;               /* Current data generation */
+
+    /* Protected by reqs_lock.  */
+    CoMutex reqs_lock;
+    QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
+    CoQueue flush_queue;                  /* Serializing flush queue */
+    bool active_flush_req;                /* Flush request in flight? */
+
+    /* Only read/written by whoever has set active_flush_req to true.  */
+    unsigned int flushed_gen;             /* Flushed write generation */
 };
 
 struct BlockBackendRootState {