Merge remote-tracking branch 'remotes/jnsnow/tags/bitmaps-pull-request' into staging

Pull request

# gpg: Signature made Wed 18 Mar 2020 20:23:28 GMT
# gpg:                using RSA key F9B7ABDBBCACDF95BE76CBD07DEF8106AAFC390E
# gpg: Good signature from "John Snow (John Huston) <jsnow@redhat.com>" [full]
# Primary key fingerprint: FAEB 9711 A12C F475 812F  18F2 88A9 064D 1835 61EB
#      Subkey fingerprint: F9B7 ABDB BCAC DF95 BE76  CBD0 7DEF 8106 AAFC 390E

* remotes/jnsnow/tags/bitmaps-pull-request:
  block/qcow2-bitmap: use bdrv_dirty_bitmap_next_dirty
  nbd/server: use bdrv_dirty_bitmap_next_dirty_area
  nbd/server: introduce NBDExtentArray
  block/dirty-bitmap: improve _next_dirty_area API
  block/dirty-bitmap: add _next_dirty API
  block/dirty-bitmap: switch _next_dirty_area and _next_zero to int64_t
  hbitmap: drop meta bitmaps as they are unused
  hbitmap: unpublish hbitmap_iter_skip_words
  hbitmap: move hbitmap_iter_next_word to hbitmap.c
  hbitmap: assert that we don't create bitmap larger than INT64_MAX
  build: Silence clang warning on older glib autoptr usage

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 33 insertions, 73 deletions

diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index e2b20ecab9..8a10029418 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -105,10 +105,13 @@ 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);
+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,
-                                       uint64_t *offset, uint64_t *bytes);
+        int64_t start, int64_t end, int64_t max_dirty_count,
+        int64_t *dirty_start, int64_t *dirty_count);
 BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
                                                   Error **errp);
 
diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h
index 1bf944ca3d..5e71b6d6f7 100644
--- a/include/qemu/hbitmap.h
+++ b/include/qemu/hbitmap.h
@@ -297,12 +297,18 @@ void hbitmap_free(HBitmap *hb);
  */
 void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap *hb, uint64_t first);
 
-/* hbitmap_iter_skip_words:
- * @hbi: HBitmapIter to operate on.
+/*
+ * hbitmap_next_dirty:
+ *
+ * Find next dirty bit within selected range. If not found, return -1.
  *
- * Internal function used by hbitmap_iter_next and hbitmap_iter_next_word.
+ * @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 INT64_MAX as @count to search up to
+ * the bitmap end.
  */
-unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi);
+int64_t hbitmap_next_dirty(const HBitmap *hb, int64_t start, int64_t count);
 
 /* hbitmap_next_zero:
  *
@@ -311,47 +317,28 @@ unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi);
  * @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
+ * bitmap is looked through. You can use INT64_MAX as @count to search up to
  * the bitmap end.
  */
-int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start, uint64_t count);
+int64_t hbitmap_next_zero(const HBitmap *hb, int64_t start, int64_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 [@start, @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
- * free it.
- *
- * Currently, we only guarantee that if a bit in the hbitmap is changed it
- * will be reflected in the meta bitmap, but we do not yet guarantee the
- * opposite.
- *
- * @hb: The HBitmap to operate on.
- * @chunk_size: How many bits in @hb does one bit in the meta track.
- */
-HBitmap *hbitmap_create_meta(HBitmap *hb, int chunk_size);
-
-/* hbitmap_free_meta:
- * Free the meta bitmap of @hb.
- *
- * @hb: The HBitmap whose meta bitmap should be freed.
- */
-void hbitmap_free_meta(HBitmap *hb);
+ * @start: the offset to start from
+ * @end: end of requested area
+ * @max_dirty_count: limit for out parameter dirty_count
+ * @dirty_start: on success: start of found area
+ * @dirty_count: on success: length of found area
+ *
+ * If dirty area found within [@start, @end), returns true and sets
+ * @dirty_start and @dirty_count appropriately. @dirty_count will not exceed
+ * @max_dirty_count.
+ * If dirty area was not found, returns false and leaves @dirty_start and
+ * @dirty_count unchanged.
+ */
+bool hbitmap_next_dirty_area(const HBitmap *hb, int64_t start, int64_t end,
+                             int64_t max_dirty_count,
+                             int64_t *dirty_start, int64_t *dirty_count);
 
 /**
  * hbitmap_iter_next:
@@ -362,34 +349,4 @@ void hbitmap_free_meta(HBitmap *hb);
  */
 int64_t hbitmap_iter_next(HBitmapIter *hbi);
 
-/**
- * hbitmap_iter_next_word:
- * @hbi: HBitmapIter to operate on.
- * @p_cur: Location where to store the next non-zero word.
- *
- * Return the index of the next nonzero word that is set in @hbi's
- * associated HBitmap, and set *p_cur to the content of that word
- * (bits before the index that was passed to hbitmap_iter_init are
- * trimmed on the first call).  Return -1, and set *p_cur to zero,
- * if all remaining words are zero.
- */
-static inline size_t hbitmap_iter_next_word(HBitmapIter *hbi, unsigned long *p_cur)
-{
-    unsigned long cur = hbi->cur[HBITMAP_LEVELS - 1];
-
-    if (cur == 0) {
-        cur = hbitmap_iter_skip_words(hbi);
-        if (cur == 0) {
-            *p_cur = 0;
-            return -1;
-        }
-    }
-
-    /* The next call will resume work from the next word.  */
-    hbi->cur[HBITMAP_LEVELS - 1] = 0;
-    *p_cur = cur;
-    return hbi->pos;
-}
-
-
 #endif