[Qemu-devel] [PATCH 3/5] block/dirty-bitmap: rework bdrv_remove_persistent_dirty_bitmap

[John Snow]

Allow propagating error code information from
bdrv_remove_persistent_dirty_bitmap as well.

Give it an interface that matches the newly revised
bdrv_add_persistent_dirty_bitmap, including removing the persistent flag
when the operation succeeds and refusing to operate on bitmaps that are
not persistent.

Signed-off-by: John Snow <address@hidden>
---
 block/qcow2.h                |  6 +++---
 include/block/block_int.h    |  6 +++---
 include/block/dirty-bitmap.h |  6 +++---
 block/dirty-bitmap.c         | 25 ++++++++++++++++++++-----
 block/qcow2-bitmap.c         | 16 +++++++++-------
 blockdev.c                   | 15 ++++++---------
 6 files changed, 44 insertions(+), 30 deletions(-)

diff --git a/block/qcow2.h b/block/qcow2.h
index 95d723d3c0..ce07f003f7 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -745,9 +745,9 @@ int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error 
**errp);
 int qcow2_add_persistent_dirty_bitmap(BlockDriverState *bs,
                                       BdrvDirtyBitmap *bitmap,
                                       Error **errp);
-void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
-                                          const char *name,
-                                          Error **errp);
+int qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
+                                         BdrvDirtyBitmap *bitmap,
+                                         Error **errp);
 
 ssize_t coroutine_fn
 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 93bbb66cd0..59f8cb9c12 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -540,9 +540,9 @@ struct BlockDriver {
     int (*bdrv_add_persistent_dirty_bitmap)(BlockDriverState *bs,
                                             BdrvDirtyBitmap *bitmap,
                                             Error **errp);
-    void (*bdrv_remove_persistent_dirty_bitmap)(BlockDriverState *bs,
-                                                const char *name,
-                                                Error **errp);
+    int (*bdrv_remove_persistent_dirty_bitmap)(BlockDriverState *bs,
+                                               BdrvDirtyBitmap *bitmap,
+                                               Error **errp);
 
     /**
      * Register/unregister a buffer for I/O. For example, when the driver is
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index c37edbe05f..88a9832ddc 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -41,9 +41,9 @@ void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs);
 int bdrv_add_persistent_dirty_bitmap(BlockDriverState *bs,
                                       BdrvDirtyBitmap *bitmap,
                                       Error **errp);
-void bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs,
-                                         const char *name,
-                                         Error **errp);
+int bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs,
+                                        BdrvDirtyBitmap *bitmap,
+                                        Error **errp);
 void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap);
 void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap);
 void bdrv_enable_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap);
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 615f8480b2..4667f9e65a 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -455,15 +455,30 @@ void bdrv_release_named_dirty_bitmaps(BlockDriverState 
*bs)
  * BdrvDirtyBitmap can have .persistent = true but not yet saved and have no
  * stored version. For such bitmap bdrv_remove_persistent_dirty_bitmap() should
  * not fail.
- * This function doesn't release corresponding BdrvDirtyBitmap.
+ * This function doesn't release the corresponding BdrvDirtyBitmap.
  */
-void bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs,
-                                         const char *name,
-                                         Error **errp)
+int bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs,
+                                        BdrvDirtyBitmap *bitmap,
+                                        Error **errp)
 {
+    int ret = 0;
+
+    if (!bdrv_dirty_bitmap_get_persistence(bitmap)) {
+        error_setg(errp, "Bitmap '%s' is not persistent, "
+                   "so it cannot be removed from node '%s'",
+                   bdrv_dirty_bitmap_name(bitmap),
+                   bdrv_get_device_or_node_name(bs));
+        return -EINVAL;
+    }
+
     if (bs->drv && bs->drv->bdrv_remove_persistent_dirty_bitmap) {
-        bs->drv->bdrv_remove_persistent_dirty_bitmap(bs, name, errp);
+        ret = bs->drv->bdrv_remove_persistent_dirty_bitmap(bs, bitmap, errp);
     }
+    if (!ret) {
+        bdrv_dirty_bitmap_set_persistence(bitmap, false);
+    }
+
+    return ret;
 }
 
 int bdrv_add_persistent_dirty_bitmap(BlockDriverState *bs,
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index c3a72ca782..930a6c91ff 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -1402,23 +1402,24 @@ static Qcow2Bitmap *find_bitmap_by_name(Qcow2BitmapList 
*bm_list,
     return NULL;
 }
 
-void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
-                                          const char *name,
-                                          Error **errp)
+int qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
+                                         BdrvDirtyBitmap *bitmap,
+                                         Error **errp)
 {
-    int ret;
+    int ret = 0;
     BDRVQcow2State *s = bs->opaque;
     Qcow2Bitmap *bm;
     Qcow2BitmapList *bm_list;
+    const char *name = bdrv_dirty_bitmap_name(bitmap);
 
     if (s->nb_bitmaps == 0) {
         /* Absence of the bitmap is not an error: see explanation above
          * bdrv_remove_persistent_dirty_bitmap() definition. */
-        return;
+        return 0;
     }
 
-    if (bitmap_list_load(bs, &bm_list, errp)) {
-        return;
+    if ((ret = bitmap_list_load(bs, &bm_list, errp))) {
+        return ret;
     }
 
     bm = find_bitmap_by_name(bm_list, name);
@@ -1439,6 +1440,7 @@ void 
qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
 fail:
     bitmap_free(bm);
     bitmap_list_free(bm_list);
+    return ret;
 }
 
 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp)
diff --git a/blockdev.c b/blockdev.c
index 169a8da831..82f02d8e72 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2875,7 +2875,6 @@ void qmp_block_dirty_bitmap_remove(const char *node, 
const char *name,
 {
     BlockDriverState *bs;
     BdrvDirtyBitmap *bitmap;
-    Error *local_err = NULL;
     AioContext *aio_context = NULL;
 
     bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
@@ -2889,20 +2888,18 @@ void qmp_block_dirty_bitmap_remove(const char *node, 
const char *name,
     }
 
     if (bdrv_dirty_bitmap_get_persistence(bitmap)) {
+        int ret;
+
         aio_context = bdrv_get_aio_context(bs);
         aio_context_acquire(aio_context);
-        bdrv_remove_persistent_dirty_bitmap(bs, name, &local_err);
-        if (local_err != NULL) {
-            error_propagate(errp, local_err);
-            goto out;
+        ret = bdrv_remove_persistent_dirty_bitmap(bs, bitmap, errp);
+        aio_context_release(aio_context);
+        if (ret) {
+            return;
         }
     }
 
     bdrv_release_dirty_bitmap(bs, bitmap);
- out:
-    if (aio_context) {
-        aio_context_release(aio_context);
-    }
 }
 
 /**
-- 
2.20.1