diff mbox

[v4,6/9] block: Add bdrv_copy_dirty_bitmap and bdrv_reset_dirty_bitmap

Message ID 1395911388-31027-7-git-send-email-famz@redhat.com
State New
Headers show

Commit Message

Fam Zheng March 27, 2014, 9:09 a.m. UTC 
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block.c               | 30 ++++++++++++++++++++++++++++--
 include/block/block.h |  4 ++++
 2 files changed, 32 insertions(+), 2 deletions(-)

Comments

Stefan Hajnoczi March 28, 2014, 8:04 a.m. UTC | #1 
On Thu, Mar 27, 2014 at 05:09:45PM +0800, Fam Zheng wrote:
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  block.c               | 30 ++++++++++++++++++++++++++++--
>  include/block/block.h |  4 ++++
>  2 files changed, 32 insertions(+), 2 deletions(-)
> 
> diff --git a/block.c b/block.c
> index 6b82bf0..0abc593 100644
> --- a/block.c
> +++ b/block.c
> @@ -52,6 +52,8 @@
>  
>  struct BdrvDirtyBitmap {
>      HBitmap *bitmap;
> +    int64_t size;
> +    int64_t granularity;

HBitmap *hbitmap_alloc(uint64_t size, int granularity)

Please use the same types as hbitmap_alloc() for size and granularity.
This way there's less chance of truncation, signedness, or
overflow/underflow problems later.  Code becomes messy if types are
inconsistent.

> +void bdrv_reset_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
> +{
> +    HBitmap *original = bitmap->bitmap;
> +
> +    bitmap->bitmap = hbitmap_alloc(bitmap->size, bitmap->granularity);
> +    hbitmap_free(original);
> +}

hbitmap_reset() exists, why allocate a new instance?  If speed is a
concern then add a special case to hbitmap_reset() for clearing the
entire bitmap quickly.  That way all callers benefit and don't have to
work around the missing functionality like you did here.
diff mbox

Patch

diff --git a/block.c b/block.c
index 6b82bf0..0abc593 100644
--- a/block.c
+++ b/block.c
@@ -52,6 +52,8 @@ 
 
 struct BdrvDirtyBitmap {
     HBitmap *bitmap;
+    int64_t size;
+    int64_t granularity;
     char *name;
     QLIST_ENTRY(BdrvDirtyBitmap) list;
 };
@@ -5097,6 +5099,29 @@  void bdrv_dirty_bitmap_make_anon(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
     bitmap->name = NULL;
 }
 
+BdrvDirtyBitmap *bdrv_copy_dirty_bitmap(BlockDriverState *bs,
+                                        const BdrvDirtyBitmap *bitmap,
+                                        const char *name)
+{
+    BdrvDirtyBitmap *new_bitmap;
+
+    new_bitmap = g_memdup(bitmap, sizeof(BdrvDirtyBitmap));
+    new_bitmap->bitmap = hbitmap_copy(bitmap->bitmap);
+    if (name) {
+        new_bitmap->name = g_strdup(name);
+    }
+    QLIST_INSERT_HEAD(&bs->dirty_bitmaps, new_bitmap, list);
+    return new_bitmap;
+}
+
+void bdrv_reset_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
+{
+    HBitmap *original = bitmap->bitmap;
+
+    bitmap->bitmap = hbitmap_alloc(bitmap->size, bitmap->granularity);
+    hbitmap_free(original);
+}
+
 BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
                                           int granularity,
                                           const char *name,
@@ -5118,9 +5143,10 @@  BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
         error_setg(errp, "could not get length of device");
         return NULL;
     }
-    bitmap_size >>= BDRV_SECTOR_BITS;
     bitmap = g_malloc0(sizeof(BdrvDirtyBitmap));
-    bitmap->bitmap = hbitmap_alloc(bitmap_size, ffs(granularity) - 1);
+    bitmap->size = bitmap_size >> BDRV_SECTOR_BITS;
+    bitmap->granularity = ffs(granularity) - 1;
+    bitmap->bitmap = hbitmap_alloc(bitmap->size, bitmap->granularity);
     if (name) {
         bitmap->name = g_strdup(name);
     }
diff --git a/include/block/block.h b/include/block/block.h
index ed85f85..a29169f 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -435,6 +435,10 @@  BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
 BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs,
                                         const char *name);
 void bdrv_dirty_bitmap_make_anon(BlockDriverState *bs, BdrvDirtyBitmap *bitmap);
+void bdrv_reset_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap);
+BdrvDirtyBitmap *bdrv_copy_dirty_bitmap(BlockDriverState *bs,
+                                        const BdrvDirtyBitmap *bitmap,
+                                        const char *name);
 void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap);
 BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs);
 int bdrv_dirty_bitmap_granularity(BlockDriverState *bs,