[Qemu-devel] [PATCH 3/4] block/dirty-bitmap: drop BdrvDirtyBitmap.mutex

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

mutex field is just a pointer to bs->dirty_bitmap_mutex, so no needs
to store it in BdrvDirtyBitmap when we have bs pointer in it (since
previous patch).

Drop mutex field. Constantly use bdrv_dirty_bitmaps_lock/unlock in
block/dirty-bitmap.c to make it more obvious that it's not per-bitmap
lock. Still, for simplicity, leave bdrv_dirty_bitmap_lock/unlock
functions as an external API.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/dirty-bitmap.c | 84 +++++++++++++++++++++-----------------------
 1 file changed, 41 insertions(+), 43 deletions(-)

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index f3dc7b3ca5..76a8e59e61 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -28,7 +28,6 @@
 #include "block/blockjob.h"
 
 struct BdrvDirtyBitmap {
-    QemuMutex *mutex;
     BlockDriverState *bs;
     HBitmap *bitmap;            /* Dirty bitmap implementation */
     bool busy;                  /* Bitmap is busy, it can't be used via QMP */
@@ -71,12 +70,12 @@ static inline void bdrv_dirty_bitmaps_unlock(BlockDriverState *bs)
 
 void bdrv_dirty_bitmap_lock(BdrvDirtyBitmap *bitmap)
 {
-    qemu_mutex_lock(bitmap->mutex);
+    bdrv_dirty_bitmaps_lock(bitmap->bs);
 }
 
 void bdrv_dirty_bitmap_unlock(BdrvDirtyBitmap *bitmap)
 {
-    qemu_mutex_unlock(bitmap->mutex);
+    bdrv_dirty_bitmaps_unlock(bitmap->bs);
 }
 
 /* Called with BQL or dirty_bitmap lock taken.  */
@@ -116,7 +115,6 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
     }
     bitmap = g_new0(BdrvDirtyBitmap, 1);
     bitmap->bs = bs;
-    bitmap->mutex = &bs->dirty_bitmap_mutex;
     bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(granularity));
     bitmap->size = bitmap_size;
     bitmap->name = g_strdup(name);
@@ -150,9 +148,9 @@ static bool bdrv_dirty_bitmap_busy(const BdrvDirtyBitmap *bitmap)
 
 void bdrv_dirty_bitmap_set_busy(BdrvDirtyBitmap *bitmap, bool busy)
 {
-    qemu_mutex_lock(bitmap->mutex);
+    bdrv_dirty_bitmaps_lock(bitmap->bs);
     bitmap->busy = busy;
-    qemu_mutex_unlock(bitmap->mutex);
+    bdrv_dirty_bitmaps_unlock(bitmap->bs);
 }
 
 /* Called with BQL taken.  */
@@ -277,10 +275,10 @@ void bdrv_enable_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap)
 /* Called with BQL taken. */
 void bdrv_dirty_bitmap_enable_successor(BdrvDirtyBitmap *bitmap)
 {
-    assert(bitmap->mutex == bitmap->successor->mutex);
-    qemu_mutex_lock(bitmap->mutex);
+    assert(bitmap->bs == bitmap->successor->bs);
+    bdrv_dirty_bitmaps_lock(bitmap->bs);
     bdrv_enable_dirty_bitmap_locked(bitmap->successor);
-    qemu_mutex_unlock(bitmap->mutex);
+    bdrv_dirty_bitmaps_unlock(bitmap->bs);
 }
 
 /* Called within bdrv_dirty_bitmap_lock..unlock and with BQL taken.  */
@@ -360,9 +358,9 @@ BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BdrvDirtyBitmap *parent,
 {
     BdrvDirtyBitmap *ret;
 
-    qemu_mutex_lock(parent->mutex);
+    bdrv_dirty_bitmaps_lock(parent->bs);
     ret = bdrv_reclaim_dirty_bitmap_locked(parent, errp);
-    qemu_mutex_unlock(parent->mutex);
+    bdrv_dirty_bitmaps_unlock(parent->bs);
 
     return ret;
 }
@@ -434,16 +432,16 @@ void bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs,
 
 void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 {
-    bdrv_dirty_bitmap_lock(bitmap);
+    bdrv_dirty_bitmaps_lock(bitmap->bs);
     bitmap->disabled = true;
-    bdrv_dirty_bitmap_unlock(bitmap);
+    bdrv_dirty_bitmaps_unlock(bitmap->bs);
 }
 
 void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 {
-    bdrv_dirty_bitmap_lock(bitmap);
+    bdrv_dirty_bitmaps_lock(bitmap->bs);
     bdrv_enable_dirty_bitmap_locked(bitmap);
-    bdrv_dirty_bitmap_unlock(bitmap);
+    bdrv_dirty_bitmaps_unlock(bitmap->bs);
 }
 
 BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
@@ -484,9 +482,9 @@ bool bdrv_dirty_bitmap_get_locked(BdrvDirtyBitmap *bitmap, int64_t offset)
 bool bdrv_dirty_bitmap_get(BdrvDirtyBitmap *bitmap, int64_t offset)
 {
     bool ret;
-    bdrv_dirty_bitmap_lock(bitmap);
+    bdrv_dirty_bitmaps_lock(bitmap->bs);
     ret = bdrv_dirty_bitmap_get_locked(bitmap, offset);
-    bdrv_dirty_bitmap_unlock(bitmap);
+    bdrv_dirty_bitmaps_unlock(bitmap->bs);
 
     return ret;
 }
@@ -551,9 +549,9 @@ void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
 void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
                            int64_t offset, int64_t bytes)
 {
-    bdrv_dirty_bitmap_lock(bitmap);
+    bdrv_dirty_bitmaps_lock(bitmap->bs);
     bdrv_set_dirty_bitmap_locked(bitmap, offset, bytes);
-    bdrv_dirty_bitmap_unlock(bitmap);
+    bdrv_dirty_bitmaps_unlock(bitmap->bs);
 }
 
 /* Called within bdrv_dirty_bitmap_lock..unlock */
@@ -567,15 +565,15 @@ void bdrv_reset_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
 void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
                              int64_t offset, int64_t bytes)
 {
-    bdrv_dirty_bitmap_lock(bitmap);
+    bdrv_dirty_bitmaps_lock(bitmap->bs);
     bdrv_reset_dirty_bitmap_locked(bitmap, offset, bytes);
-    bdrv_dirty_bitmap_unlock(bitmap);
+    bdrv_dirty_bitmaps_unlock(bitmap->bs);
 }
 
 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
 {
     assert(!bdrv_dirty_bitmap_readonly(bitmap));
-    bdrv_dirty_bitmap_lock(bitmap);
+    bdrv_dirty_bitmaps_lock(bitmap->bs);
     if (!out) {
         hbitmap_reset_all(bitmap->bitmap);
     } else {
@@ -584,7 +582,7 @@ void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
                                        hbitmap_granularity(backup));
         *out = backup;
     }
-    bdrv_dirty_bitmap_unlock(bitmap);
+    bdrv_dirty_bitmaps_unlock(bitmap->bs);
 }
 
 void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *backup)
@@ -679,9 +677,9 @@ bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap *bitmap)
 /* Called with BQL taken. */
 void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap, bool value)
 {
-    qemu_mutex_lock(bitmap->mutex);
+    bdrv_dirty_bitmaps_lock(bitmap->bs);
     bitmap->readonly = value;
-    qemu_mutex_unlock(bitmap->mutex);
+    bdrv_dirty_bitmaps_unlock(bitmap->bs);
 }
 
 bool bdrv_has_readonly_bitmaps(BlockDriverState *bs)
@@ -699,27 +697,27 @@ bool bdrv_has_readonly_bitmaps(BlockDriverState *bs)
 /* Called with BQL taken. */
 void bdrv_dirty_bitmap_set_persistence(BdrvDirtyBitmap *bitmap, bool persistent)
 {
-    qemu_mutex_lock(bitmap->mutex);
+    bdrv_dirty_bitmaps_lock(bitmap->bs);
     bitmap->persistent = persistent;
-    qemu_mutex_unlock(bitmap->mutex);
+    bdrv_dirty_bitmaps_unlock(bitmap->bs);
 }
 
 /* Called with BQL taken. */
 void bdrv_dirty_bitmap_set_inconsistent(BdrvDirtyBitmap *bitmap)
 {
-    qemu_mutex_lock(bitmap->mutex);
+    bdrv_dirty_bitmaps_lock(bitmap->bs);
     assert(bitmap->persistent == true);
     bitmap->inconsistent = true;
     bitmap->disabled = true;
-    qemu_mutex_unlock(bitmap->mutex);
+    bdrv_dirty_bitmaps_unlock(bitmap->bs);
 }
 
 /* Called with BQL taken. */
 void bdrv_dirty_bitmap_skip_store(BdrvDirtyBitmap *bitmap, bool skip)
 {
-    qemu_mutex_lock(bitmap->mutex);
+    bdrv_dirty_bitmaps_lock(bitmap->bs);
     bitmap->skip_store = skip;
-    qemu_mutex_unlock(bitmap->mutex);
+    bdrv_dirty_bitmaps_unlock(bitmap->bs);
 }
 
 bool bdrv_dirty_bitmap_get_persistence(BdrvDirtyBitmap *bitmap)
@@ -779,9 +777,9 @@ void bdrv_merge_dirty_bitmap(BdrvDirtyBitmap *dest, const BdrvDirtyBitmap *src,
 {
     bool ret;
 
-    qemu_mutex_lock(dest->mutex);
-    if (src->mutex != dest->mutex) {
-        qemu_mutex_lock(src->mutex);
+    bdrv_dirty_bitmaps_lock(dest->bs);
+    if (src->bs != dest->bs) {
+        bdrv_dirty_bitmaps_lock(src->bs);
     }
 
     if (bdrv_dirty_bitmap_check(dest, BDRV_BITMAP_DEFAULT, errp)) {
@@ -801,9 +799,9 @@ void bdrv_merge_dirty_bitmap(BdrvDirtyBitmap *dest, const BdrvDirtyBitmap *src,
     assert(ret);
 
 out:
-    qemu_mutex_unlock(dest->mutex);
-    if (src->mutex != dest->mutex) {
-        qemu_mutex_unlock(src->mutex);
+    bdrv_dirty_bitmaps_unlock(dest->bs);
+    if (src->bs != dest->bs) {
+        bdrv_dirty_bitmaps_unlock(src->bs);
     }
 }
 
@@ -827,9 +825,9 @@ bool bdrv_dirty_bitmap_merge_internal(BdrvDirtyBitmap *dest,
     assert(!bdrv_dirty_bitmap_inconsistent(src));
 
     if (lock) {
-        qemu_mutex_lock(dest->mutex);
-        if (src->mutex != dest->mutex) {
-            qemu_mutex_lock(src->mutex);
+        bdrv_dirty_bitmaps_lock(dest->bs);
+        if (src->bs != dest->bs) {
+            bdrv_dirty_bitmaps_lock(src->bs);
         }
     }
 
@@ -842,9 +840,9 @@ bool bdrv_dirty_bitmap_merge_internal(BdrvDirtyBitmap *dest,
     }
 
     if (lock) {
-        qemu_mutex_unlock(dest->mutex);
-        if (src->mutex != dest->mutex) {
-            qemu_mutex_unlock(src->mutex);
+        bdrv_dirty_bitmaps_unlock(dest->bs);
+        if (src->bs != dest->bs) {
+            bdrv_dirty_bitmaps_unlock(src->bs);
         }
     }
 
-- 
2.21.0