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[Qemu-devel] [PATCH 2/4] block/dirty-bitmap: add _next_dirty API
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[Qemu-devel] [PATCH 2/4] block/dirty-bitmap: add _next_dirty API |
Date: |
Wed, 14 Aug 2019 17:43:13 +0300 |
We have bdrv_dirty_bitmap_next_zero, let's add corresponding
bdrv_dirty_bitmap_next_dirty, which is more comfortable to use than
bitmap iterators in some cases. It will be used in the following
commit.
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
include/block/dirty-bitmap.h | 2 ++
include/qemu/hbitmap.h | 13 ++++++++
block/dirty-bitmap.c | 6 ++++
util/hbitmap.c | 61 +++++++++++++++++++-----------------
4 files changed, 54 insertions(+), 28 deletions(-)
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 493c4566d3..d1310ee76e 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -108,6 +108,8 @@ bool bdrv_has_changed_persistent_bitmaps(BlockDriverState
*bs);
BdrvDirtyBitmap *bdrv_dirty_bitmap_next(BlockDriverState *bs,
BdrvDirtyBitmap *bitmap);
char *bdrv_dirty_bitmap_sha256(const BdrvDirtyBitmap *bitmap, Error **errp);
+int64_t bdrv_dirty_bitmap_next_dirty(BdrvDirtyBitmap *bitmap, int64_t offset,
+ int64_t bytes);
int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, int64_t offset,
int64_t bytes);
bool bdrv_dirty_bitmap_next_dirty_area(BdrvDirtyBitmap *bitmap,
diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h
index 5149ac7721..80ecabe8e2 100644
--- a/include/qemu/hbitmap.h
+++ b/include/qemu/hbitmap.h
@@ -299,6 +299,19 @@ void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap
*hb, uint64_t first);
*/
unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi);
+/*
+ * hbitmap_next_dirty:
+ *
+ * Find next dirty bit within selected range. If not found, return -1.
+ *
+ * @hb: The HBitmap to operate on
+ * @start: The bit to start from.
+ * @count: Number of bits to proceed. If @start+@count > bitmap size, the whole
+ * bitmap is looked through. You can use UINT64_MAX as @count to search up to
+ * the bitmap end.
+ */
+int64_t hbitmap_next_dirty(const HBitmap *hb, int64_t start, int64_t count);
+
/* hbitmap_next_zero:
*
* Find next not dirty bit within selected range. If not found, return -1.
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index eeccdb48f5..efe3a39d49 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -802,6 +802,12 @@ char *bdrv_dirty_bitmap_sha256(const BdrvDirtyBitmap
*bitmap, Error **errp)
return hbitmap_sha256(bitmap->bitmap, errp);
}
+int64_t bdrv_dirty_bitmap_next_dirty(BdrvDirtyBitmap *bitmap, int64_t offset,
+ int64_t bytes)
+{
+ return hbitmap_next_zero(bitmap->bitmap, offset, bytes);
+}
+
int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, int64_t offset,
int64_t bytes)
{
diff --git a/util/hbitmap.c b/util/hbitmap.c
index c08751fb50..3f2d7451ce 100644
--- a/util/hbitmap.c
+++ b/util/hbitmap.c
@@ -193,6 +193,30 @@ void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap
*hb, uint64_t first)
}
}
+int64_t hbitmap_next_dirty(const HBitmap *hb, int64_t start, int64_t count)
+{
+ HBitmapIter hbi;
+ int64_t firt_dirty_off;
+ uint64_t end;
+
+ assert(start >= 0 && count >= 0);
+
+ if (start >= hb->orig_size || count == 0) {
+ return -1;
+ }
+
+ end = count > hb->orig_size - start ? hb->orig_size : start + count;
+
+ hbitmap_iter_init(&hbi, hb, start);
+ firt_dirty_off = hbitmap_iter_next(&hbi);
+
+ if (firt_dirty_off < 0 || firt_dirty_off >= end) {
+ return -1;
+ }
+
+ return MAX(start, firt_dirty_off);
+}
+
int64_t hbitmap_next_zero(const HBitmap *hb, int64_t start, int64_t count)
{
size_t pos = (start >> hb->granularity) >> BITS_PER_LEVEL;
@@ -248,40 +272,21 @@ int64_t hbitmap_next_zero(const HBitmap *hb, int64_t
start, int64_t count)
bool hbitmap_next_dirty_area(const HBitmap *hb, int64_t *start, int64_t *count)
{
- HBitmapIter hbi;
- int64_t firt_dirty_off, area_end;
- uint32_t granularity = 1UL << hb->granularity;
- uint64_t end;
-
- assert(*start >= 0 && *count >= 0);
-
- if (*start >= hb->orig_size || *count == 0) {
- return false;
- }
-
- end = *count > hb->orig_size - *start ? hb->orig_size : *start + *count;
-
- hbitmap_iter_init(&hbi, hb, *start);
- firt_dirty_off = hbitmap_iter_next(&hbi);
+ int64_t area_start, area_end;
- if (firt_dirty_off < 0 || firt_dirty_off >= end) {
+ area_start = hbitmap_next_dirty(hb, *start, *count);
+ if (area_start < 0) {
return false;
}
- if (firt_dirty_off + granularity >= end) {
- area_end = end;
- } else {
- area_end = hbitmap_next_zero(hb, firt_dirty_off + granularity,
- end - firt_dirty_off - granularity);
- if (area_end < 0) {
- area_end = end;
- }
+ area_end = QEMU_ALIGN_UP(area_start + 1, 1UL << hb->granularity);
+ area_end = hbitmap_next_zero(hb, area_end, *start + *count - area_end);
+ if (area_end < 0) {
+ area_end = MIN(hb->orig_size, *start + *count);
}
- if (firt_dirty_off > *start) {
- *start = firt_dirty_off;
- }
- *count = area_end - *start;
+ *start = area_start;
+ *count = area_end - area_start;
return true;
}
--
2.18.0