[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 4/4] block/dirty-bitmap: refactor bdrv_dirty_bit
From: |
John Snow |
Subject: |
Re: [Qemu-devel] [PATCH 4/4] block/dirty-bitmap: refactor bdrv_dirty_bitmap_next |
Date: |
Thu, 26 Sep 2019 14:54:42 -0400 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.0 |
On 9/16/19 10:19 AM, Vladimir Sementsov-Ogievskiy wrote:
> bdrv_dirty_bitmap_next is always used in same pattern. So, split it
> into _next and _first, instead of combining two functions into one and
> add FOR_EACH_DIRTY_BITMAP macro.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
> ---
> include/block/dirty-bitmap.h | 9 +++++++--
> block.c | 4 +---
> block/dirty-bitmap.c | 11 +++++++----
> block/qcow2-bitmap.c | 8 ++------
> migration/block-dirty-bitmap.c | 4 +---
> 5 files changed, 18 insertions(+), 18 deletions(-)
I'm not as sure that this is an improvement.
>
> diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
> index 4c58d922e4..89e52db7ec 100644
> --- a/include/block/dirty-bitmap.h
> +++ b/include/block/dirty-bitmap.h
> @@ -97,8 +97,13 @@ bool bdrv_dirty_bitmap_get_autoload(const BdrvDirtyBitmap
> *bitmap);
> bool bdrv_dirty_bitmap_get_persistence(BdrvDirtyBitmap *bitmap);
> bool bdrv_dirty_bitmap_inconsistent(const BdrvDirtyBitmap *bitmap);
> bool bdrv_has_changed_persistent_bitmaps(BlockDriverState *bs);
> -BdrvDirtyBitmap *bdrv_dirty_bitmap_next(BlockDriverState *bs,
> - BdrvDirtyBitmap *bitmap);
> +
> +BdrvDirtyBitmap *bdrv_dirty_bitmap_first(BlockDriverState *bs);
> +BdrvDirtyBitmap *bdrv_dirty_bitmap_next(BdrvDirtyBitmap *bitmap);
> +#define FOR_EACH_DIRTY_BITMAP(bs, bitmap) \
> +for (bitmap = bdrv_dirty_bitmap_first(bs); bitmap; \
> + bitmap = bdrv_dirty_bitmap_next(bitmap))
> +
> char *bdrv_dirty_bitmap_sha256(const BdrvDirtyBitmap *bitmap, Error **errp);
> int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, uint64_t offset,
> uint64_t bytes);
> diff --git a/block.c b/block.c
> index 5944124845..96c2c5ae2d 100644
> --- a/block.c
> +++ b/block.c
> @@ -5363,9 +5363,7 @@ static void coroutine_fn
> bdrv_co_invalidate_cache(BlockDriverState *bs,
> }
> }
>
> - for (bm = bdrv_dirty_bitmap_next(bs, NULL); bm;
> - bm = bdrv_dirty_bitmap_next(bs, bm))
> - {
> + FOR_EACH_DIRTY_BITMAP(bs, bm) {
> bdrv_dirty_bitmap_skip_store(bm, false);
> }
... and I kind of prefer loops with explicit function calls more than I
like macro-loops.
>
> diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
> index 76a8e59e61..e2df82af01 100644
> --- a/block/dirty-bitmap.c
> +++ b/block/dirty-bitmap.c
> @@ -742,11 +742,14 @@ bool
> bdrv_has_changed_persistent_bitmaps(BlockDriverState *bs)
> return false;
> }
>
> -BdrvDirtyBitmap *bdrv_dirty_bitmap_next(BlockDriverState *bs,
> - BdrvDirtyBitmap *bitmap)
> +BdrvDirtyBitmap *bdrv_dirty_bitmap_first(BlockDriverState *bs)
> {
> - return bitmap == NULL ? QLIST_FIRST(&bs->dirty_bitmaps) :
> - QLIST_NEXT(bitmap, list);
> + return QLIST_FIRST(&bs->dirty_bitmaps);
> +}
> +
> +BdrvDirtyBitmap *bdrv_dirty_bitmap_next(BdrvDirtyBitmap *bitmap)
> +{
> + return QLIST_NEXT(bitmap, list);
> }
>
> char *bdrv_dirty_bitmap_sha256(const BdrvDirtyBitmap *bitmap, Error **errp)
> diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
> index 6d795a2255..73ebd2ff6a 100644
> --- a/block/qcow2-bitmap.c
> +++ b/block/qcow2-bitmap.c
> @@ -1480,9 +1480,7 @@ void
> qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp)
> }
>
> /* check constraints and names */
> - for (bitmap = bdrv_dirty_bitmap_next(bs, NULL); bitmap != NULL;
> - bitmap = bdrv_dirty_bitmap_next(bs, bitmap))
> - {
> + FOR_EACH_DIRTY_BITMAP(bs, bitmap) {
> const char *name = bdrv_dirty_bitmap_name(bitmap);
> uint32_t granularity = bdrv_dirty_bitmap_granularity(bitmap);
> Qcow2Bitmap *bm;
> @@ -1602,9 +1600,7 @@ int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error
> **errp)
> return -EINVAL;
> }
>
> - for (bitmap = bdrv_dirty_bitmap_next(bs, NULL); bitmap != NULL;
> - bitmap = bdrv_dirty_bitmap_next(bs, bitmap))
> - {
> + FOR_EACH_DIRTY_BITMAP(bs, bitmap) {
> if (bdrv_dirty_bitmap_get_persistence(bitmap)) {
> bdrv_dirty_bitmap_set_readonly(bitmap, true);
> }
> diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
> index 793f249aa5..7eafface61 100644
> --- a/migration/block-dirty-bitmap.c
> +++ b/migration/block-dirty-bitmap.c
> @@ -283,9 +283,7 @@ static int init_dirty_bitmap_migration(void)
> for (bs = bdrv_next_all_states(NULL); bs; bs = bdrv_next_all_states(bs))
> {
> const char *name = bdrv_get_device_or_node_name(bs);
>
> - for (bitmap = bdrv_dirty_bitmap_next(bs, NULL); bitmap;
> - bitmap = bdrv_dirty_bitmap_next(bs, bitmap))
> - {
> + FOR_EACH_DIRTY_BITMAP(bs, bitmap) {
> if (!bdrv_dirty_bitmap_name(bitmap)) {
> continue;
> }
>
Well, I guess explicit first and next functions is harder to mess up,
anyway.
Reviewed-by: John Snow <address@hidden>
(Any other thoughts?)
[Qemu-block] [PATCH 1/4] block/dirty-bitmap: drop meta, Vladimir Sementsov-Ogievskiy, 2019/09/16
[Qemu-block] [PATCH 2/4] block/dirty-bitmap: add bs link, Vladimir Sementsov-Ogievskiy, 2019/09/16
[Qemu-block] [PATCH 3/4] block/dirty-bitmap: drop BdrvDirtyBitmap.mutex, Vladimir Sementsov-Ogievskiy, 2019/09/16