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[Qemu-block] [PATCH v4 3/8] dirty-bitmap: add bdrv_dirty_bitmap_next_dir
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[Qemu-block] [PATCH v4 3/8] dirty-bitmap: add bdrv_dirty_bitmap_next_dirty_area |
Date: |
Mon, 17 Sep 2018 17:57:27 +0300 |
The function alters bdrv_dirty_iter_next_area(), which is wrong and
less efficient (see further commit
"block/mirror: fix and improve do_sync_target_write" for description).
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
include/block/dirty-bitmap.h | 2 ++
include/qemu/hbitmap.h | 16 +++++++++++++++
block/dirty-bitmap.c | 6 ++++++
util/hbitmap.c | 39 ++++++++++++++++++++++++++++++++++++
4 files changed, 63 insertions(+)
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 1a23c76862..7ad2a1357a 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -100,6 +100,8 @@ BdrvDirtyBitmap *bdrv_dirty_bitmap_next(BlockDriverState
*bs,
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);
+bool bdrv_dirty_bitmap_next_dirty_area(BdrvDirtyBitmap *bitmap,
+ uint64_t *offset, uint64_t *bytes);
BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap_locked(BlockDriverState *bs,
BdrvDirtyBitmap *bitmap,
Error **errp);
diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h
index 8a399c1c9c..495a99e78e 100644
--- a/include/qemu/hbitmap.h
+++ b/include/qemu/hbitmap.h
@@ -304,6 +304,22 @@ unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi);
*/
int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start, uint64_t count);
+/* hbitmap_next_dirty_area:
+ * @hb: The HBitmap to operate on
+ * @start: in-out parameter.
+ * in: the offset to start from
+ * out: (if area found) start of found area
+ * @count: in-out parameter.
+ * in: length of requested region
+ * out: length of found area
+ *
+ * If dirty area found within address@hidden, @start + @count), returns true
and sets
+ * @offset and @bytes appropriately. Otherwise returns false and leaves @offset
+ * and @bytes unchanged.
+ */
+bool hbitmap_next_dirty_area(const HBitmap *hb, uint64_t *start,
+ uint64_t *count);
+
/* hbitmap_create_meta:
* Create a "meta" hbitmap to track dirtiness of the bits in this HBitmap.
* The caller owns the created bitmap and must call hbitmap_free_meta(hb) to
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index a9ee814da7..7ee8b27368 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -791,6 +791,12 @@ int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap
*bitmap, uint64_t offset,
return hbitmap_next_zero(bitmap->bitmap, offset, bytes);
}
+bool bdrv_dirty_bitmap_next_dirty_area(BdrvDirtyBitmap *bitmap,
+ uint64_t *offset, uint64_t *bytes)
+{
+ return hbitmap_next_dirty_area(bitmap->bitmap, offset, bytes);
+}
+
void bdrv_merge_dirty_bitmap(BdrvDirtyBitmap *dest, const BdrvDirtyBitmap *src,
Error **errp)
{
diff --git a/util/hbitmap.c b/util/hbitmap.c
index a18c68fb2f..5beca86740 100644
--- a/util/hbitmap.c
+++ b/util/hbitmap.c
@@ -246,6 +246,45 @@ int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t
start, uint64_t count)
return res;
}
+bool hbitmap_next_dirty_area(const HBitmap *hb, uint64_t *start,
+ uint64_t *count)
+{
+ HBitmapIter hbi;
+ int64_t firt_dirty_off, area_end;
+ uint32_t granularity = 1UL << hb->granularity;
+ uint64_t end;
+
+ 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, false);
+
+ if (firt_dirty_off < 0 || firt_dirty_off >= end) {
+ 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;
+ }
+ }
+
+ if (firt_dirty_off > *start) {
+ *start = firt_dirty_off;
+ }
+ *count = area_end - *start;
+
+ return true;
+}
+
bool hbitmap_empty(const HBitmap *hb)
{
return hb->count == 0;
--
2.18.0
- [Qemu-block] [PATCH v4 0/8] dirty-bitmap: rewrite bdrv_dirty_iter_next_area, Vladimir Sementsov-Ogievskiy, 2018/09/17
- [Qemu-block] [PATCH v4 5/8] block/mirror: fix and improve do_sync_target_write, Vladimir Sementsov-Ogievskiy, 2018/09/17
- [Qemu-block] [PATCH v4 3/8] dirty-bitmap: add bdrv_dirty_bitmap_next_dirty_area,
Vladimir Sementsov-Ogievskiy <=
- [Qemu-block] [PATCH v4 4/8] tests: add tests for hbitmap_next_dirty_area, Vladimir Sementsov-Ogievskiy, 2018/09/17
- [Qemu-block] [PATCH v4 2/8] tests: add tests for hbitmap_next_zero with specified end parameter, Vladimir Sementsov-Ogievskiy, 2018/09/17
- [Qemu-block] [PATCH v4 7/8] Revert "test-hbitmap: Add non-advancing iter_next tests", Vladimir Sementsov-Ogievskiy, 2018/09/17
- [Qemu-block] [PATCH v4 6/8] Revert "block/dirty-bitmap: Add bdrv_dirty_iter_next_area", Vladimir Sementsov-Ogievskiy, 2018/09/17
- [Qemu-block] [PATCH v4 8/8] Revert "hbitmap: Add @advance param to hbitmap_iter_next()", Vladimir Sementsov-Ogievskiy, 2018/09/17
- [Qemu-block] [PATCH v4 1/8] dirty-bitmap: improve bdrv_dirty_bitmap_next_zero, Vladimir Sementsov-Ogievskiy, 2018/09/17