[PATCH v4 00/10] Further bitmaps improvements

[PATCH v4 00/10] Further bitmaps improvements

[Vladimir Sementsov-Ogievskiy]

Hi!

The main feature here is improvement of _next_dirty_area API, which I'm
going to use then for backup / block-copy.

Somehow, I thought that it was merged, but seems I even forgot to send
v4.

v4:
01-04: add Max's r-b
05: switch test_hbitmap_next_zero_check_range args to int64_t too
06: fix s/UINT64_MAX/INT64_MAX/ in comment to hbitmap_next_dirty
    s/firt_dirty_off/first_dirty_off/
    Context changed due to 05 change, but I keep Max's r-b
07: simplify parameter check in hbitmap_next_dirty_area
    drop initialization in hbitmap_sparse_merge
    add Max's r-b
08: commit message tweak
    refactor converted flag to separated converted_to_be and can_add
    do not convert to be automatically in nbd_extent_array_add
    check uint32 overflow in nbd_extent_array_add
10: drop extra check from store_bitmap_data, add Max's r-b

Vladimir Sementsov-Ogievskiy (10):
  hbitmap: assert that we don't create bitmap larger than INT64_MAX
  hbitmap: move hbitmap_iter_next_word to hbitmap.c
  hbitmap: unpublish hbitmap_iter_skip_words
  hbitmap: drop meta bitmaps as they are unused
  block/dirty-bitmap: switch _next_dirty_area and _next_zero to int64_t
  block/dirty-bitmap: add _next_dirty API
  block/dirty-bitmap: improve _next_dirty_area API
  nbd/server: introduce NBDExtentArray
  nbd/server: use bdrv_dirty_bitmap_next_dirty_area
  block/qcow2-bitmap: use bdrv_dirty_bitmap_next_dirty

 include/block/dirty-bitmap.h |   9 +-
 include/qemu/hbitmap.h       |  97 +++--------
 block/dirty-bitmap.c         |  16 +-
 block/qcow2-bitmap.c         |  15 +-
 nbd/server.c                 | 251 ++++++++++++++--------------
 tests/test-hbitmap.c         | 314 +++++++++++++----------------------
 util/hbitmap.c               | 134 +++++++++------
 7 files changed, 375 insertions(+), 461 deletions(-)

-- 
2.21.0

[PATCH v4 01/10] hbitmap: assert that we don't create bitmap larger than INT64_MAX

[Vladimir Sementsov-Ogievskiy]

We have APIs which returns signed int64_t, to be able to return error.
Therefore we can't handle bitmaps with absolute size larger than
(INT64_MAX+1). Still, keep maximum to be INT64_MAX which is a bit
safer.

Note, that bitmaps are used to represent disk images, which can't
exceed INT64_MAX anyway.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 util/hbitmap.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/util/hbitmap.c b/util/hbitmap.c
index 242c6e519c..7f9b3e0cd7 100644
--- a/util/hbitmap.c
+++ b/util/hbitmap.c
@@ -716,6 +716,7 @@ HBitmap *hbitmap_alloc(uint64_t size, int granularity)
     HBitmap *hb = g_new0(struct HBitmap, 1);
     unsigned i;
 
+    assert(size <= INT64_MAX);
     hb->orig_size = size;
 
     assert(granularity >= 0 && granularity < 64);
@@ -746,6 +747,7 @@ void hbitmap_truncate(HBitmap *hb, uint64_t size)
     uint64_t num_elements = size;
     uint64_t old;
 
+    assert(size <= INT64_MAX);
     hb->orig_size = size;
 
     /* Size comes in as logical elements, adjust for granularity. */
-- 
2.21.0

[PATCH v4 02/10] hbitmap: move hbitmap_iter_next_word to hbitmap.c

[Vladimir Sementsov-Ogievskiy]

The function is definitely internal (it's not used by third party and
it has complicated interface). Move it to .c file.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 include/qemu/hbitmap.h | 30 ------------------------------
 util/hbitmap.c         | 29 +++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 30 deletions(-)

diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h
index 1bf944ca3d..ab227b117f 100644
--- a/include/qemu/hbitmap.h
+++ b/include/qemu/hbitmap.h
@@ -362,34 +362,4 @@ 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
diff --git a/util/hbitmap.c b/util/hbitmap.c
index 7f9b3e0cd7..a368dc5ef7 100644
--- a/util/hbitmap.c
+++ b/util/hbitmap.c
@@ -298,6 +298,35 @@ uint64_t hbitmap_count(const HBitmap *hb)
     return hb->count << hb->granularity;
 }
 
+/**
+ * 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 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;
+}
+
 /* Count the number of set bits between start and end, not accounting for
  * the granularity.  Also an example of how to use hbitmap_iter_next_word.
  */
-- 
2.21.0

[PATCH v4 03/10] hbitmap: unpublish hbitmap_iter_skip_words

[Vladimir Sementsov-Ogievskiy]

Function is internal and even commented as internal. Drop its
definition from .h file.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 include/qemu/hbitmap.h | 7 -------
 util/hbitmap.c         | 2 +-
 2 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h
index ab227b117f..15837a0e2d 100644
--- a/include/qemu/hbitmap.h
+++ b/include/qemu/hbitmap.h
@@ -297,13 +297,6 @@ 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.
- *
- * Internal function used by hbitmap_iter_next and hbitmap_iter_next_word.
- */
-unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi);
-
 /* hbitmap_next_zero:
  *
  * Find next not dirty bit within selected range. If not found, return -1.
diff --git a/util/hbitmap.c b/util/hbitmap.c
index a368dc5ef7..26145d4b9e 100644
--- a/util/hbitmap.c
+++ b/util/hbitmap.c
@@ -104,7 +104,7 @@ struct HBitmap {
 /* Advance hbi to the next nonzero word and return it.  hbi->pos
  * is updated.  Returns zero if we reach the end of the bitmap.
  */
-unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi)
+static unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi)
 {
     size_t pos = hbi->pos;
     const HBitmap *hb = hbi->hb;
-- 
2.21.0

[PATCH v4 04/10] hbitmap: drop meta bitmaps as they are unused

[Vladimir Sementsov-Ogievskiy]

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 include/qemu/hbitmap.h |  21 --------
 tests/test-hbitmap.c   | 115 -----------------------------------------
 util/hbitmap.c         |  16 ------
 3 files changed, 152 deletions(-)

diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h
index 15837a0e2d..df922d8517 100644
--- a/include/qemu/hbitmap.h
+++ b/include/qemu/hbitmap.h
@@ -325,27 +325,6 @@ int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start, uint64_t count);
 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);
-
 /**
  * hbitmap_iter_next:
  * @hbi: HBitmapIter to operate on.
diff --git a/tests/test-hbitmap.c b/tests/test-hbitmap.c
index e1f867085f..aeaa0b3f22 100644
--- a/tests/test-hbitmap.c
+++ b/tests/test-hbitmap.c
@@ -22,7 +22,6 @@
 
 typedef struct TestHBitmapData {
     HBitmap       *hb;
-    HBitmap       *meta;
     unsigned long *bits;
     size_t         size;
     size_t         old_size;
@@ -94,14 +93,6 @@ static void hbitmap_test_init(TestHBitmapData *data,
     }
 }
 
-static void hbitmap_test_init_meta(TestHBitmapData *data,
-                                   uint64_t size, int granularity,
-                                   int meta_chunk)
-{
-    hbitmap_test_init(data, size, granularity);
-    data->meta = hbitmap_create_meta(data->hb, meta_chunk);
-}
-
 static inline size_t hbitmap_test_array_size(size_t bits)
 {
     size_t n = DIV_ROUND_UP(bits, BITS_PER_LONG);
@@ -144,9 +135,6 @@ static void hbitmap_test_teardown(TestHBitmapData *data,
                                   const void *unused)
 {
     if (data->hb) {
-        if (data->meta) {
-            hbitmap_free_meta(data->hb);
-        }
         hbitmap_free(data->hb);
         data->hb = NULL;
     }
@@ -648,96 +636,6 @@ static void test_hbitmap_truncate_shrink_large(TestHBitmapData *data,
     hbitmap_test_truncate(data, size, -diff, 0);
 }
 
-static void hbitmap_check_meta(TestHBitmapData *data,
-                               int64_t start, int count)
-{
-    int64_t i;
-
-    for (i = 0; i < data->size; i++) {
-        if (i >= start && i < start + count) {
-            g_assert(hbitmap_get(data->meta, i));
-        } else {
-            g_assert(!hbitmap_get(data->meta, i));
-        }
-    }
-}
-
-static void hbitmap_test_meta(TestHBitmapData *data,
-                              int64_t start, int count,
-                              int64_t check_start, int check_count)
-{
-    hbitmap_reset_all(data->hb);
-    hbitmap_reset_all(data->meta);
-
-    /* Test "unset" -> "unset" will not update meta. */
-    hbitmap_reset(data->hb, start, count);
-    hbitmap_check_meta(data, 0, 0);
-
-    /* Test "unset" -> "set" will update meta */
-    hbitmap_set(data->hb, start, count);
-    hbitmap_check_meta(data, check_start, check_count);
-
-    /* Test "set" -> "set" will not update meta */
-    hbitmap_reset_all(data->meta);
-    hbitmap_set(data->hb, start, count);
-    hbitmap_check_meta(data, 0, 0);
-
-    /* Test "set" -> "unset" will update meta */
-    hbitmap_reset_all(data->meta);
-    hbitmap_reset(data->hb, start, count);
-    hbitmap_check_meta(data, check_start, check_count);
-}
-
-static void hbitmap_test_meta_do(TestHBitmapData *data, int chunk_size)
-{
-    uint64_t size = chunk_size * 100;
-    hbitmap_test_init_meta(data, size, 0, chunk_size);
-
-    hbitmap_test_meta(data, 0, 1, 0, chunk_size);
-    hbitmap_test_meta(data, 0, chunk_size, 0, chunk_size);
-    hbitmap_test_meta(data, chunk_size - 1, 1, 0, chunk_size);
-    hbitmap_test_meta(data, chunk_size - 1, 2, 0, chunk_size * 2);
-    hbitmap_test_meta(data, chunk_size - 1, chunk_size + 1, 0, chunk_size * 2);
-    hbitmap_test_meta(data, chunk_size - 1, chunk_size + 2, 0, chunk_size * 3);
-    hbitmap_test_meta(data, 7 * chunk_size - 1, chunk_size + 2,
-                      6 * chunk_size, chunk_size * 3);
-    hbitmap_test_meta(data, size - 1, 1, size - chunk_size, chunk_size);
-    hbitmap_test_meta(data, 0, size, 0, size);
-}
-
-static void test_hbitmap_meta_byte(TestHBitmapData *data, const void *unused)
-{
-    hbitmap_test_meta_do(data, BITS_PER_BYTE);
-}
-
-static void test_hbitmap_meta_word(TestHBitmapData *data, const void *unused)
-{
-    hbitmap_test_meta_do(data, BITS_PER_LONG);
-}
-
-static void test_hbitmap_meta_sector(TestHBitmapData *data, const void *unused)
-{
-    hbitmap_test_meta_do(data, BDRV_SECTOR_SIZE * BITS_PER_BYTE);
-}
-
-/**
- * Create an HBitmap and test set/unset.
- */
-static void test_hbitmap_meta_one(TestHBitmapData *data, const void *unused)
-{
-    int i;
-    int64_t offsets[] = {
-        0, 1, L1 - 1, L1, L1 + 1, L2 - 1, L2, L2 + 1, L3 - 1, L3, L3 + 1
-    };
-
-    hbitmap_test_init_meta(data, L3 * 2, 0, 1);
-    for (i = 0; i < ARRAY_SIZE(offsets); i++) {
-        hbitmap_test_meta(data, offsets[i], 1, offsets[i], 1);
-        hbitmap_test_meta(data, offsets[i], L1, offsets[i], L1);
-        hbitmap_test_meta(data, offsets[i], L2, offsets[i], L2);
-    }
-}
-
 static void test_hbitmap_serialize_align(TestHBitmapData *data,
                                          const void *unused)
 {
@@ -750,13 +648,6 @@ static void test_hbitmap_serialize_align(TestHBitmapData *data,
     g_assert_cmpint(r, ==, 64 << 3);
 }
 
-static void test_hbitmap_meta_zero(TestHBitmapData *data, const void *unused)
-{
-    hbitmap_test_init_meta(data, 0, 0, 1);
-
-    hbitmap_check_meta(data, 0, 0);
-}
-
 static void hbitmap_test_serialize_range(TestHBitmapData *data,
                                          uint8_t *buf, size_t buf_size,
                                          uint64_t pos, uint64_t count)
@@ -1165,12 +1056,6 @@ int main(int argc, char **argv)
     hbitmap_test_add("/hbitmap/truncate/shrink/large",
                      test_hbitmap_truncate_shrink_large);
 
-    hbitmap_test_add("/hbitmap/meta/zero", test_hbitmap_meta_zero);
-    hbitmap_test_add("/hbitmap/meta/one", test_hbitmap_meta_one);
-    hbitmap_test_add("/hbitmap/meta/byte", test_hbitmap_meta_byte);
-    hbitmap_test_add("/hbitmap/meta/word", test_hbitmap_meta_word);
-    hbitmap_test_add("/hbitmap/meta/sector", test_hbitmap_meta_sector);
-
     hbitmap_test_add("/hbitmap/serialize/align",
                      test_hbitmap_serialize_align);
     hbitmap_test_add("/hbitmap/serialize/basic",
diff --git a/util/hbitmap.c b/util/hbitmap.c
index 26145d4b9e..b6d4b99a06 100644
--- a/util/hbitmap.c
+++ b/util/hbitmap.c
@@ -905,22 +905,6 @@ bool hbitmap_merge(const HBitmap *a, const HBitmap *b, HBitmap *result)
     return true;
 }
 
-HBitmap *hbitmap_create_meta(HBitmap *hb, int chunk_size)
-{
-    assert(!(chunk_size & (chunk_size - 1)));
-    assert(!hb->meta);
-    hb->meta = hbitmap_alloc(hb->size << hb->granularity,
-                             hb->granularity + ctz32(chunk_size));
-    return hb->meta;
-}
-
-void hbitmap_free_meta(HBitmap *hb)
-{
-    assert(hb->meta);
-    hbitmap_free(hb->meta);
-    hb->meta = NULL;
-}
-
 char *hbitmap_sha256(const HBitmap *bitmap, Error **errp)
 {
     size_t size = bitmap->sizes[HBITMAP_LEVELS - 1] * sizeof(unsigned long);
-- 
2.21.0

[PATCH v4 05/10] block/dirty-bitmap: switch _next_dirty_area and _next_zero to int64_t

[Vladimir Sementsov-Ogievskiy]

We are going to introduce bdrv_dirty_bitmap_next_dirty so that same
variable may be used to store its return value and to be its parameter,
so it would int64_t.

Similarly, we are going to refactor hbitmap_next_dirty_area to use
hbitmap_next_dirty together with hbitmap_next_zero, therefore we want
hbitmap_next_zero parameter type to be int64_t too.

So, for convenience update all parameters of *_next_zero and
*_next_dirty_area to be int64_t.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 include/block/dirty-bitmap.h |  6 +++---
 include/qemu/hbitmap.h       |  7 +++----
 block/dirty-bitmap.c         |  6 +++---
 nbd/server.c                 |  2 +-
 tests/test-hbitmap.c         | 36 ++++++++++++++++++------------------
 util/hbitmap.c               | 13 ++++++++-----
 6 files changed, 36 insertions(+), 34 deletions(-)

diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index e2b20ecab9..27c72cc56a 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -105,10 +105,10 @@ 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_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 *offset, int64_t *bytes);
 BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
                                                   Error **errp);
 
diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h
index df922d8517..b6e85f3d5d 100644
--- a/include/qemu/hbitmap.h
+++ b/include/qemu/hbitmap.h
@@ -304,10 +304,10 @@ void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap *hb, uint64_t first);
  * @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
@@ -322,8 +322,7 @@ int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start, uint64_t count);
  * @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);
+bool hbitmap_next_dirty_area(const HBitmap *hb, int64_t *start, int64_t *count);
 
 /**
  * hbitmap_iter_next:
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 7039e82520..af9f5411a6 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -860,14 +860,14 @@ char *bdrv_dirty_bitmap_sha256(const BdrvDirtyBitmap *bitmap, Error **errp)
     return hbitmap_sha256(bitmap->bitmap, errp);
 }
 
-int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, uint64_t offset,
-                                    uint64_t bytes)
+int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, int64_t offset,
+                                    int64_t bytes)
 {
     return hbitmap_next_zero(bitmap->bitmap, offset, bytes);
 }
 
 bool bdrv_dirty_bitmap_next_dirty_area(BdrvDirtyBitmap *bitmap,
-                                       uint64_t *offset, uint64_t *bytes)
+                                       int64_t *offset, int64_t *bytes)
 {
     return hbitmap_next_dirty_area(bitmap->bitmap, offset, bytes);
 }
diff --git a/nbd/server.c b/nbd/server.c
index 87fcd2e7bf..c422265041 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -2055,7 +2055,7 @@ static unsigned int bitmap_to_extents(BdrvDirtyBitmap *bitmap, uint64_t offset,
         bool next_dirty = !dirty;
 
         if (dirty) {
-            end = bdrv_dirty_bitmap_next_zero(bitmap, begin, UINT64_MAX);
+            end = bdrv_dirty_bitmap_next_zero(bitmap, begin, INT64_MAX);
         } else {
             bdrv_set_dirty_iter(it, begin);
             end = bdrv_dirty_iter_next(it);
diff --git a/tests/test-hbitmap.c b/tests/test-hbitmap.c
index aeaa0b3f22..9d210dc18c 100644
--- a/tests/test-hbitmap.c
+++ b/tests/test-hbitmap.c
@@ -817,8 +817,8 @@ static void test_hbitmap_iter_and_reset(TestHBitmapData *data,
 }
 
 static void test_hbitmap_next_zero_check_range(TestHBitmapData *data,
-                                               uint64_t start,
-                                               uint64_t count)
+                                               int64_t start,
+                                               int64_t count)
 {
     int64_t ret1 = hbitmap_next_zero(data->hb, start, count);
     int64_t ret2 = start;
@@ -837,7 +837,7 @@ static void test_hbitmap_next_zero_check_range(TestHBitmapData *data,
 
 static void test_hbitmap_next_zero_check(TestHBitmapData *data, int64_t start)
 {
-    test_hbitmap_next_zero_check_range(data, start, UINT64_MAX);
+    test_hbitmap_next_zero_check_range(data, start, INT64_MAX);
 }
 
 static void test_hbitmap_next_zero_do(TestHBitmapData *data, int granularity)
@@ -905,11 +905,11 @@ static void test_hbitmap_next_zero_after_truncate(TestHBitmapData *data,
 }
 
 static void test_hbitmap_next_dirty_area_check(TestHBitmapData *data,
-                                               uint64_t offset,
-                                               uint64_t count)
+                                               int64_t offset,
+                                               int64_t count)
 {
-    uint64_t off1, off2;
-    uint64_t len1 = 0, len2;
+    int64_t off1, off2;
+    int64_t len1 = 0, len2;
     bool ret1, ret2;
     int64_t end;
 
@@ -945,24 +945,24 @@ static void test_hbitmap_next_dirty_area_do(TestHBitmapData *data,
                                             int granularity)
 {
     hbitmap_test_init(data, L3, granularity);
-    test_hbitmap_next_dirty_area_check(data, 0, UINT64_MAX);
+    test_hbitmap_next_dirty_area_check(data, 0, INT64_MAX);
     test_hbitmap_next_dirty_area_check(data, 0, 1);
     test_hbitmap_next_dirty_area_check(data, L3 - 1, 1);
 
     hbitmap_set(data->hb, L2, 1);
     test_hbitmap_next_dirty_area_check(data, 0, 1);
     test_hbitmap_next_dirty_area_check(data, 0, L2);
-    test_hbitmap_next_dirty_area_check(data, 0, UINT64_MAX);
-    test_hbitmap_next_dirty_area_check(data, L2 - 1, UINT64_MAX);
+    test_hbitmap_next_dirty_area_check(data, 0, INT64_MAX);
+    test_hbitmap_next_dirty_area_check(data, L2 - 1, INT64_MAX);
     test_hbitmap_next_dirty_area_check(data, L2 - 1, 1);
     test_hbitmap_next_dirty_area_check(data, L2 - 1, 2);
     test_hbitmap_next_dirty_area_check(data, L2 - 1, 3);
-    test_hbitmap_next_dirty_area_check(data, L2, UINT64_MAX);
+    test_hbitmap_next_dirty_area_check(data, L2, INT64_MAX);
     test_hbitmap_next_dirty_area_check(data, L2, 1);
     test_hbitmap_next_dirty_area_check(data, L2 + 1, 1);
 
     hbitmap_set(data->hb, L2 + 5, L1);
-    test_hbitmap_next_dirty_area_check(data, 0, UINT64_MAX);
+    test_hbitmap_next_dirty_area_check(data, 0, INT64_MAX);
     test_hbitmap_next_dirty_area_check(data, L2 - 2, 8);
     test_hbitmap_next_dirty_area_check(data, L2 + 1, 5);
     test_hbitmap_next_dirty_area_check(data, L2 + 1, 3);
@@ -974,16 +974,16 @@ static void test_hbitmap_next_dirty_area_do(TestHBitmapData *data,
     test_hbitmap_next_dirty_area_check(data, L2 + 1, 0);
 
     hbitmap_set(data->hb, L2 * 2, L3 - L2 * 2);
-    test_hbitmap_next_dirty_area_check(data, 0, UINT64_MAX);
-    test_hbitmap_next_dirty_area_check(data, L2, UINT64_MAX);
-    test_hbitmap_next_dirty_area_check(data, L2 + 1, UINT64_MAX);
-    test_hbitmap_next_dirty_area_check(data, L2 + 5 + L1 - 1, UINT64_MAX);
+    test_hbitmap_next_dirty_area_check(data, 0, INT64_MAX);
+    test_hbitmap_next_dirty_area_check(data, L2, INT64_MAX);
+    test_hbitmap_next_dirty_area_check(data, L2 + 1, INT64_MAX);
+    test_hbitmap_next_dirty_area_check(data, L2 + 5 + L1 - 1, INT64_MAX);
     test_hbitmap_next_dirty_area_check(data, L2 + 5 + L1, 5);
     test_hbitmap_next_dirty_area_check(data, L2 * 2 - L1, L1 + 1);
     test_hbitmap_next_dirty_area_check(data, L2 * 2, L2);
 
     hbitmap_set(data->hb, 0, L3);
-    test_hbitmap_next_dirty_area_check(data, 0, UINT64_MAX);
+    test_hbitmap_next_dirty_area_check(data, 0, INT64_MAX);
 }
 
 static void test_hbitmap_next_dirty_area_0(TestHBitmapData *data,
@@ -1010,7 +1010,7 @@ static void test_hbitmap_next_dirty_area_after_truncate(TestHBitmapData *data,
     hbitmap_test_init(data, L1, 0);
     hbitmap_test_truncate_impl(data, L1 * 2);
     hbitmap_set(data->hb, L1 + 1, 1);
-    test_hbitmap_next_dirty_area_check(data, 0, UINT64_MAX);
+    test_hbitmap_next_dirty_area_check(data, 0, INT64_MAX);
 }
 
 int main(int argc, char **argv)
diff --git a/util/hbitmap.c b/util/hbitmap.c
index b6d4b99a06..df22f06be6 100644
--- a/util/hbitmap.c
+++ b/util/hbitmap.c
@@ -193,7 +193,7 @@ void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap *hb, uint64_t first)
     }
 }
 
-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)
 {
     size_t pos = (start >> hb->granularity) >> BITS_PER_LEVEL;
     unsigned long *last_lev = hb->levels[HBITMAP_LEVELS - 1];
@@ -202,6 +202,8 @@ int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start, uint64_t count)
     uint64_t end_bit, sz;
     int64_t res;
 
+    assert(start >= 0 && count >= 0);
+
     if (start >= hb->orig_size || count == 0) {
         return -1;
     }
@@ -244,14 +246,15 @@ 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)
+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;
     }
@@ -834,8 +837,8 @@ bool hbitmap_can_merge(const HBitmap *a, const HBitmap *b)
  */
 static void hbitmap_sparse_merge(HBitmap *dst, const HBitmap *src)
 {
-    uint64_t offset = 0;
-    uint64_t count = src->orig_size;
+    int64_t offset = 0;
+    int64_t count = src->orig_size;
 
     while (hbitmap_next_dirty_area(src, &offset, &count)) {
         hbitmap_set(dst, offset, count);
-- 
2.21.0

[PATCH v4 06/10] block/dirty-bitmap: add _next_dirty API

[Vladimir Sementsov-Ogievskiy]

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.

For test modify test_hbitmap_next_zero_check_range to check both
next_zero and next_dirty and add some new checks.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 include/block/dirty-bitmap.h |   2 +
 include/qemu/hbitmap.h       |  13 ++++
 block/dirty-bitmap.c         |   6 ++
 tests/test-hbitmap.c         | 130 ++++++++++++++++++++---------------
 util/hbitmap.c               |  60 ++++++++--------
 5 files changed, 126 insertions(+), 85 deletions(-)

diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 27c72cc56a..b1f0de12db 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -105,6 +105,8 @@ 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_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 b6e85f3d5d..6e9ae51ed3 100644
--- a/include/qemu/hbitmap.h
+++ b/include/qemu/hbitmap.h
@@ -297,6 +297,19 @@ void hbitmap_free(HBitmap *hb);
  */
 void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap *hb, uint64_t first);
 
+/*
+ * 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 INT64_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 af9f5411a6..1b14c8eb26 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -860,6 +860,12 @@ 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_dirty(bitmap->bitmap, offset, bytes);
+}
+
 int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, int64_t offset,
                                     int64_t bytes)
 {
diff --git a/tests/test-hbitmap.c b/tests/test-hbitmap.c
index 9d210dc18c..8905b8a351 100644
--- a/tests/test-hbitmap.c
+++ b/tests/test-hbitmap.c
@@ -816,92 +816,108 @@ static void test_hbitmap_iter_and_reset(TestHBitmapData *data,
     hbitmap_iter_next(&hbi);
 }
 
-static void test_hbitmap_next_zero_check_range(TestHBitmapData *data,
-                                               int64_t start,
-                                               int64_t count)
+static void test_hbitmap_next_x_check_range(TestHBitmapData *data,
+                                            int64_t start,
+                                            int64_t count)
 {
-    int64_t ret1 = hbitmap_next_zero(data->hb, start, count);
-    int64_t ret2 = start;
+    int64_t next_zero = hbitmap_next_zero(data->hb, start, count);
+    int64_t next_dirty = hbitmap_next_dirty(data->hb, start, count);
+    int64_t next;
     int64_t end = start >= data->size || data->size - start < count ?
                 data->size : start + count;
+    bool first_bit = hbitmap_get(data->hb, start);
 
-    for ( ; ret2 < end && hbitmap_get(data->hb, ret2); ret2++) {
+    for (next = start;
+         next < end && hbitmap_get(data->hb, next) == first_bit;
+         next++)
+    {
         ;
     }
-    if (ret2 == end) {
-        ret2 = -1;
+
+    if (next == end) {
+        next = -1;
     }
 
-    g_assert_cmpint(ret1, ==, ret2);
+    g_assert_cmpint(next_dirty, ==, first_bit ? start : next);
+    g_assert_cmpint(next_zero, ==, first_bit ? next : start);
 }
 
-static void test_hbitmap_next_zero_check(TestHBitmapData *data, int64_t start)
+static void test_hbitmap_next_x_check(TestHBitmapData *data, int64_t start)
 {
-    test_hbitmap_next_zero_check_range(data, start, INT64_MAX);
+    test_hbitmap_next_x_check_range(data, start, INT64_MAX);
 }
 
-static void test_hbitmap_next_zero_do(TestHBitmapData *data, int granularity)
+static void test_hbitmap_next_x_do(TestHBitmapData *data, int granularity)
 {
     hbitmap_test_init(data, L3, granularity);
-    test_hbitmap_next_zero_check(data, 0);
-    test_hbitmap_next_zero_check(data, L3 - 1);
-    test_hbitmap_next_zero_check_range(data, 0, 1);
-    test_hbitmap_next_zero_check_range(data, L3 - 1, 1);
+    test_hbitmap_next_x_check(data, 0);
+    test_hbitmap_next_x_check(data, L3 - 1);
+    test_hbitmap_next_x_check_range(data, 0, 1);
+    test_hbitmap_next_x_check_range(data, L3 - 1, 1);
 
     hbitmap_set(data->hb, L2, 1);
-    test_hbitmap_next_zero_check(data, 0);
-    test_hbitmap_next_zero_check(data, L2 - 1);
-    test_hbitmap_next_zero_check(data, L2);
-    test_hbitmap_next_zero_check(data, L2 + 1);
-    test_hbitmap_next_zero_check_range(data, 0, 1);
-    test_hbitmap_next_zero_check_range(data, 0, L2);
-    test_hbitmap_next_zero_check_range(data, L2 - 1, 1);
-    test_hbitmap_next_zero_check_range(data, L2 - 1, 2);
-    test_hbitmap_next_zero_check_range(data, L2, 1);
-    test_hbitmap_next_zero_check_range(data, L2 + 1, 1);
+    test_hbitmap_next_x_check(data, 0);
+    test_hbitmap_next_x_check(data, L2 - 1);
+    test_hbitmap_next_x_check(data, L2);
+    test_hbitmap_next_x_check(data, L2 + 1);
+    test_hbitmap_next_x_check_range(data, 0, 1);
+    test_hbitmap_next_x_check_range(data, 0, L2);
+    test_hbitmap_next_x_check_range(data, L2 - 1, 1);
+    test_hbitmap_next_x_check_range(data, L2 - 1, 2);
+    test_hbitmap_next_x_check_range(data, L2, 1);
+    test_hbitmap_next_x_check_range(data, L2 + 1, 1);
 
     hbitmap_set(data->hb, L2 + 5, L1);
-    test_hbitmap_next_zero_check(data, 0);
-    test_hbitmap_next_zero_check(data, L2 + 1);
-    test_hbitmap_next_zero_check(data, L2 + 2);
-    test_hbitmap_next_zero_check(data, L2 + 5);
-    test_hbitmap_next_zero_check(data, L2 + L1 - 1);
-    test_hbitmap_next_zero_check(data, L2 + L1);
-    test_hbitmap_next_zero_check_range(data, L2, 6);
-    test_hbitmap_next_zero_check_range(data, L2 + 1, 3);
-    test_hbitmap_next_zero_check_range(data, L2 + 4, L1);
-    test_hbitmap_next_zero_check_range(data, L2 + 5, L1);
+    test_hbitmap_next_x_check(data, 0);
+    test_hbitmap_next_x_check(data, L2 - L1);
+    test_hbitmap_next_x_check(data, L2 + 1);
+    test_hbitmap_next_x_check(data, L2 + 2);
+    test_hbitmap_next_x_check(data, L2 + 5);
+    test_hbitmap_next_x_check(data, L2 + L1 - 1);
+    test_hbitmap_next_x_check(data, L2 + L1);
+    test_hbitmap_next_x_check(data, L2 + L1 + 1);
+    test_hbitmap_next_x_check_range(data, L2 - 2, L1);
+    test_hbitmap_next_x_check_range(data, L2, 4);
+    test_hbitmap_next_x_check_range(data, L2, 6);
+    test_hbitmap_next_x_check_range(data, L2 + 1, 3);
+    test_hbitmap_next_x_check_range(data, L2 + 4, L1);
+    test_hbitmap_next_x_check_range(data, L2 + 5, L1);
+    test_hbitmap_next_x_check_range(data, L2 + 5 + L1 - 1, 1);
+    test_hbitmap_next_x_check_range(data, L2 + 5 + L1, 1);
+    test_hbitmap_next_x_check_range(data, L2 + 5 + L1 + 1, 1);
 
     hbitmap_set(data->hb, L2 * 2, L3 - L2 * 2);
-    test_hbitmap_next_zero_check(data, L2 * 2 - L1);
-    test_hbitmap_next_zero_check(data, L2 * 2 - 2);
-    test_hbitmap_next_zero_check(data, L2 * 2 - 1);
-    test_hbitmap_next_zero_check(data, L2 * 2);
-    test_hbitmap_next_zero_check(data, L3 - 1);
-    test_hbitmap_next_zero_check_range(data, L2 * 2 - L1, L1 + 1);
-    test_hbitmap_next_zero_check_range(data, L2 * 2, L2);
+    test_hbitmap_next_x_check(data, L2 * 2 - L1);
+    test_hbitmap_next_x_check(data, L2 * 2 - 2);
+    test_hbitmap_next_x_check(data, L2 * 2 - 1);
+    test_hbitmap_next_x_check(data, L2 * 2);
+    test_hbitmap_next_x_check(data, L2 * 2 + 1);
+    test_hbitmap_next_x_check(data, L2 * 2 + L1);
+    test_hbitmap_next_x_check(data, L3 - 1);
+    test_hbitmap_next_x_check_range(data, L2 * 2 - L1, L1 + 1);
+    test_hbitmap_next_x_check_range(data, L2 * 2, L2);
 
     hbitmap_set(data->hb, 0, L3);
-    test_hbitmap_next_zero_check(data, 0);
+    test_hbitmap_next_x_check(data, 0);
 }
 
-static void test_hbitmap_next_zero_0(TestHBitmapData *data, const void *unused)
+static void test_hbitmap_next_x_0(TestHBitmapData *data, const void *unused)
 {
-    test_hbitmap_next_zero_do(data, 0);
+    test_hbitmap_next_x_do(data, 0);
 }
 
-static void test_hbitmap_next_zero_4(TestHBitmapData *data, const void *unused)
+static void test_hbitmap_next_x_4(TestHBitmapData *data, const void *unused)
 {
-    test_hbitmap_next_zero_do(data, 4);
+    test_hbitmap_next_x_do(data, 4);
 }
 
-static void test_hbitmap_next_zero_after_truncate(TestHBitmapData *data,
-                                                  const void *unused)
+static void test_hbitmap_next_x_after_truncate(TestHBitmapData *data,
+                                               const void *unused)
 {
     hbitmap_test_init(data, L1, 0);
     hbitmap_test_truncate_impl(data, L1 * 2);
     hbitmap_set(data->hb, 0, L1);
-    test_hbitmap_next_zero_check(data, 0);
+    test_hbitmap_next_x_check(data, 0);
 }
 
 static void test_hbitmap_next_dirty_area_check(TestHBitmapData *data,
@@ -1068,12 +1084,12 @@ int main(int argc, char **argv)
     hbitmap_test_add("/hbitmap/iter/iter_and_reset",
                      test_hbitmap_iter_and_reset);
 
-    hbitmap_test_add("/hbitmap/next_zero/next_zero_0",
-                     test_hbitmap_next_zero_0);
-    hbitmap_test_add("/hbitmap/next_zero/next_zero_4",
-                     test_hbitmap_next_zero_4);
-    hbitmap_test_add("/hbitmap/next_zero/next_zero_after_truncate",
-                     test_hbitmap_next_zero_after_truncate);
+    hbitmap_test_add("/hbitmap/next_zero/next_x_0",
+                     test_hbitmap_next_x_0);
+    hbitmap_test_add("/hbitmap/next_zero/next_x_4",
+                     test_hbitmap_next_x_4);
+    hbitmap_test_add("/hbitmap/next_zero/next_x_after_truncate",
+                     test_hbitmap_next_x_after_truncate);
 
     hbitmap_test_add("/hbitmap/next_dirty_area/next_dirty_area_0",
                      test_hbitmap_next_dirty_area_0);
diff --git a/util/hbitmap.c b/util/hbitmap.c
index df22f06be6..883ca48fa6 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 first_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);
+    first_dirty_off = hbitmap_iter_next(&hbi);
+
+    if (first_dirty_off < 0 || first_dirty_off >= end) {
+        return -1;
+    }
+
+    return MAX(start, first_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 +272,20 @@ 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 = hbitmap_next_zero(hb, area_start, *start + *count - area_start);
+    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;
 }
-- 
2.21.0

[PATCH v4 07/10] block/dirty-bitmap: improve _next_dirty_area API

[Vladimir Sementsov-Ogievskiy]

Firstly, _next_dirty_area is for scenarios when we may contiguously
search for next dirty area inside some limited region, so it is more
comfortable to specify "end" which should not be recalculated on each
iteration.

Secondly, let's add a possibility to limit resulting area size, not
limiting searching area. This will be used in NBD code in further
commit. (Note that now bdrv_dirty_bitmap_next_dirty_area is unused)

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 include/block/dirty-bitmap.h |  3 ++-
 include/qemu/hbitmap.h       | 25 +++++++++++---------
 block/dirty-bitmap.c         |  6 +++--
 tests/test-hbitmap.c         | 43 +++++++++++++++++++++++------------
 util/hbitmap.c               | 44 ++++++++++++++++++++++--------------
 5 files changed, 75 insertions(+), 46 deletions(-)

diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index b1f0de12db..8a10029418 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -110,7 +110,8 @@ int64_t bdrv_dirty_bitmap_next_dirty(BdrvDirtyBitmap *bitmap, int64_t offset,
 int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, int64_t offset,
                                     int64_t bytes);
 bool bdrv_dirty_bitmap_next_dirty_area(BdrvDirtyBitmap *bitmap,
-                                       int64_t *offset, int64_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 6e9ae51ed3..5e71b6d6f7 100644
--- a/include/qemu/hbitmap.h
+++ b/include/qemu/hbitmap.h
@@ -324,18 +324,21 @@ 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.
+ * @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 *count);
+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:
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 1b14c8eb26..063793e316 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -873,9 +873,11 @@ int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, int64_t offset,
 }
 
 bool bdrv_dirty_bitmap_next_dirty_area(BdrvDirtyBitmap *bitmap,
-                                       int64_t *offset, int64_t *bytes)
+        int64_t start, int64_t end, int64_t max_dirty_count,
+        int64_t *dirty_start, int64_t *dirty_count)
 {
-    return hbitmap_next_dirty_area(bitmap->bitmap, offset, bytes);
+    return hbitmap_next_dirty_area(bitmap->bitmap, start, end, max_dirty_count,
+                                   dirty_start, dirty_count);
 }
 
 /**
diff --git a/tests/test-hbitmap.c b/tests/test-hbitmap.c
index 8905b8a351..b6726cf76b 100644
--- a/tests/test-hbitmap.c
+++ b/tests/test-hbitmap.c
@@ -920,18 +920,19 @@ static void test_hbitmap_next_x_after_truncate(TestHBitmapData *data,
     test_hbitmap_next_x_check(data, 0);
 }
 
-static void test_hbitmap_next_dirty_area_check(TestHBitmapData *data,
-                                               int64_t offset,
-                                               int64_t count)
+static void test_hbitmap_next_dirty_area_check_limited(TestHBitmapData *data,
+                                                       int64_t offset,
+                                                       int64_t count,
+                                                       int64_t max_dirty)
 {
     int64_t off1, off2;
     int64_t len1 = 0, len2;
     bool ret1, ret2;
     int64_t end;
 
-    off1 = offset;
-    len1 = count;
-    ret1 = hbitmap_next_dirty_area(data->hb, &off1, &len1);
+    ret1 = hbitmap_next_dirty_area(data->hb,
+            offset, count == INT64_MAX ? INT64_MAX : offset + count, max_dirty,
+            &off1, &len1);
 
     end = offset > data->size || data->size - offset < count ? data->size :
                                                                offset + count;
@@ -940,21 +941,25 @@ static void test_hbitmap_next_dirty_area_check(TestHBitmapData *data,
         ;
     }
 
-    for (len2 = 1; off2 + len2 < end && hbitmap_get(data->hb, off2 + len2);
-         len2++) {
+    for (len2 = 1; (off2 + len2 < end && len2 < max_dirty &&
+                    hbitmap_get(data->hb, off2 + len2)); len2++)
+    {
         ;
     }
 
     ret2 = off2 < end;
-    if (!ret2) {
-        /* leave unchanged */
-        off2 = offset;
-        len2 = count;
+    g_assert_cmpint(ret1, ==, ret2);
+
+    if (ret2) {
+        g_assert_cmpint(off1, ==, off2);
+        g_assert_cmpint(len1, ==, len2);
     }
+}
 
-    g_assert_cmpint(ret1, ==, ret2);
-    g_assert_cmpint(off1, ==, off2);
-    g_assert_cmpint(len1, ==, len2);
+static void test_hbitmap_next_dirty_area_check(TestHBitmapData *data,
+                                               int64_t offset, int64_t count)
+{
+    test_hbitmap_next_dirty_area_check_limited(data, offset, count, INT64_MAX);
 }
 
 static void test_hbitmap_next_dirty_area_do(TestHBitmapData *data,
@@ -964,6 +969,7 @@ static void test_hbitmap_next_dirty_area_do(TestHBitmapData *data,
     test_hbitmap_next_dirty_area_check(data, 0, INT64_MAX);
     test_hbitmap_next_dirty_area_check(data, 0, 1);
     test_hbitmap_next_dirty_area_check(data, L3 - 1, 1);
+    test_hbitmap_next_dirty_area_check_limited(data, 0, INT64_MAX, 1);
 
     hbitmap_set(data->hb, L2, 1);
     test_hbitmap_next_dirty_area_check(data, 0, 1);
@@ -976,6 +982,8 @@ static void test_hbitmap_next_dirty_area_do(TestHBitmapData *data,
     test_hbitmap_next_dirty_area_check(data, L2, INT64_MAX);
     test_hbitmap_next_dirty_area_check(data, L2, 1);
     test_hbitmap_next_dirty_area_check(data, L2 + 1, 1);
+    test_hbitmap_next_dirty_area_check_limited(data, 0, INT64_MAX, 1);
+    test_hbitmap_next_dirty_area_check_limited(data, L2 - 1, 2, 1);
 
     hbitmap_set(data->hb, L2 + 5, L1);
     test_hbitmap_next_dirty_area_check(data, 0, INT64_MAX);
@@ -988,6 +996,8 @@ static void test_hbitmap_next_dirty_area_do(TestHBitmapData *data,
     test_hbitmap_next_dirty_area_check(data, L2 + L1, L1);
     test_hbitmap_next_dirty_area_check(data, L2, 0);
     test_hbitmap_next_dirty_area_check(data, L2 + 1, 0);
+    test_hbitmap_next_dirty_area_check_limited(data, L2 + 3, INT64_MAX, 3);
+    test_hbitmap_next_dirty_area_check_limited(data, L2 + 3, 7, 10);
 
     hbitmap_set(data->hb, L2 * 2, L3 - L2 * 2);
     test_hbitmap_next_dirty_area_check(data, 0, INT64_MAX);
@@ -997,6 +1007,9 @@ static void test_hbitmap_next_dirty_area_do(TestHBitmapData *data,
     test_hbitmap_next_dirty_area_check(data, L2 + 5 + L1, 5);
     test_hbitmap_next_dirty_area_check(data, L2 * 2 - L1, L1 + 1);
     test_hbitmap_next_dirty_area_check(data, L2 * 2, L2);
+    test_hbitmap_next_dirty_area_check_limited(data, L2 * 2 + 1, INT64_MAX, 5);
+    test_hbitmap_next_dirty_area_check_limited(data, L2 * 2 + 1, 10, 5);
+    test_hbitmap_next_dirty_area_check_limited(data, L2 * 2 + 1, 2, 5);
 
     hbitmap_set(data->hb, 0, L3);
     test_hbitmap_next_dirty_area_check(data, 0, INT64_MAX);
diff --git a/util/hbitmap.c b/util/hbitmap.c
index 883ca48fa6..305b894a63 100644
--- a/util/hbitmap.c
+++ b/util/hbitmap.c
@@ -270,22 +270,33 @@ int64_t hbitmap_next_zero(const HBitmap *hb, int64_t start, int64_t count)
     return res;
 }
 
-bool hbitmap_next_dirty_area(const HBitmap *hb, int64_t *start, int64_t *count)
+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)
 {
-    int64_t area_start, area_end;
+    int64_t next_zero;
 
-    area_start = hbitmap_next_dirty(hb, *start, *count);
-    if (area_start < 0) {
+    assert(start >= 0 && end >= 0 && max_dirty_count > 0);
+
+    end = MIN(end, hb->orig_size);
+    if (start >= end) {
         return false;
     }
 
-    area_end = hbitmap_next_zero(hb, area_start, *start + *count - area_start);
-    if (area_end < 0) {
-        area_end = MIN(hb->orig_size, *start + *count);
+    start = hbitmap_next_dirty(hb, start, end - start);
+    if (start < 0) {
+        return false;
     }
 
-    *start = area_start;
-    *count = area_end - area_start;
+    end = start + MIN(end - start, max_dirty_count);
+
+    next_zero = hbitmap_next_zero(hb, start, end - start);
+    if (next_zero >= 0) {
+        end = next_zero;
+    }
+
+    *dirty_start = start;
+    *dirty_count = end - start;
 
     return true;
 }
@@ -841,16 +852,15 @@ bool hbitmap_can_merge(const HBitmap *a, const HBitmap *b)
  */
 static void hbitmap_sparse_merge(HBitmap *dst, const HBitmap *src)
 {
-    int64_t offset = 0;
-    int64_t count = src->orig_size;
+    int64_t offset;
+    int64_t count;
 
-    while (hbitmap_next_dirty_area(src, &offset, &count)) {
+    for (offset = 0;
+         hbitmap_next_dirty_area(src, offset, src->orig_size, INT64_MAX,
+                                 &offset, &count);
+         offset += count)
+    {
         hbitmap_set(dst, offset, count);
-        offset += count;
-        if (offset >= src->orig_size) {
-            break;
-        }
-        count = src->orig_size - offset;
     }
 }
 
-- 
2.21.0

[PATCH v4 08/10] nbd/server: introduce NBDExtentArray

[Vladimir Sementsov-Ogievskiy]

Introduce NBDExtentArray class, to handle extents list creation in more
controlled way and with fewer OUT parameters in functions.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 nbd/server.c | 210 +++++++++++++++++++++++++++++----------------------
 1 file changed, 118 insertions(+), 92 deletions(-)

diff --git a/nbd/server.c b/nbd/server.c
index c422265041..21e665e9e0 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -1909,27 +1909,98 @@ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client,
     return ret;
 }
 
+typedef struct NBDExtentArray {
+    NBDExtent *extents;
+    unsigned int nb_alloc;
+    unsigned int count;
+    uint64_t total_length;
+    bool can_add;
+    bool converted_to_be;
+} NBDExtentArray;
+
+static NBDExtentArray *nbd_extent_array_new(unsigned int nb_alloc)
+{
+    NBDExtentArray *ea = g_new0(NBDExtentArray, 1);
+
+    ea->nb_alloc = nb_alloc;
+    ea->extents = g_new(NBDExtent, nb_alloc);
+    ea->can_add = true;
+
+    return ea;
+}
+
+static void nbd_extent_array_free(NBDExtentArray *ea)
+{
+    g_free(ea->extents);
+    g_free(ea);
+}
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(NBDExtentArray, nbd_extent_array_free);
+
+/* Further modifications of the array after conversion are abandoned */
+static void nbd_extent_array_convert_to_be(NBDExtentArray *ea)
+{
+    int i;
+
+    assert(!ea->converted_to_be);
+    ea->can_add = false;
+    ea->converted_to_be = true;
+
+    for (i = 0; i < ea->count; i++) {
+        ea->extents[i].flags = cpu_to_be32(ea->extents[i].flags);
+        ea->extents[i].length = cpu_to_be32(ea->extents[i].length);
+    }
+}
+
 /*
- * Populate @extents from block status. Update @bytes to be the actual
- * length encoded (which may be smaller than the original), and update
- * @nb_extents to the number of extents used.
- *
- * Returns zero on success and -errno on bdrv_block_status_above failure.
+ * Add extent to NBDExtentArray. If extent can't be added (no available space),
+ * return -1.
+ * For safety, when returning -1 for the first time, .can_add is set to false,
+ * further call to nbd_extent_array_add() will crash.
+ * (to avoid the situation, when after failing to add an extent (returned -1),
+ * user miss this failure and add another extent, which is successfully added
+ * (array is full, but new extent may be squashed into the last one), then we
+ * have invalid array with skipped extent)
  */
-static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
-                                  uint64_t *bytes, NBDExtent *extents,
-                                  unsigned int *nb_extents)
+static int nbd_extent_array_add(NBDExtentArray *ea,
+                                uint32_t length, uint32_t flags)
 {
-    uint64_t remaining_bytes = *bytes;
-    NBDExtent *extent = extents, *extents_end = extents + *nb_extents;
-    bool first_extent = true;
+    assert(ea->can_add);
+
+    if (!length) {
+        return 0;
+    }
+
+    /* Extend previous extent if flags are the same */
+    if (ea->count > 0 && flags == ea->extents[ea->count - 1].flags) {
+        uint64_t sum = (uint64_t)length + ea->extents[ea->count - 1].length;
+
+        if (sum <= UINT32_MAX) {
+            ea->extents[ea->count - 1].length = sum;
+            ea->total_length += length;
+            return 0;
+        }
+    }
+
+    if (ea->count >= ea->nb_alloc) {
+        ea->can_add = false;
+        return -1;
+    }
+
+    ea->total_length += length;
+    ea->extents[ea->count] = (NBDExtent) {.length = length, .flags = flags};
+    ea->count++;
 
-    assert(*nb_extents);
-    while (remaining_bytes) {
+    return 0;
+}
+
+static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
+                                  uint64_t bytes, NBDExtentArray *ea)
+{
+    while (bytes) {
         uint32_t flags;
         int64_t num;
-        int ret = bdrv_block_status_above(bs, NULL, offset, remaining_bytes,
-                                          &num, NULL, NULL);
+        int ret = bdrv_block_status_above(bs, NULL, offset, bytes, &num,
+                                          NULL, NULL);
 
         if (ret < 0) {
             return ret;
@@ -1938,60 +2009,37 @@ static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
         flags = (ret & BDRV_BLOCK_ALLOCATED ? 0 : NBD_STATE_HOLE) |
                 (ret & BDRV_BLOCK_ZERO      ? NBD_STATE_ZERO : 0);
 
-        if (first_extent) {
-            extent->flags = flags;
-            extent->length = num;
-            first_extent = false;
-        } else if (flags == extent->flags) {
-            /* extend current extent */
-            extent->length += num;
-        } else {
-            if (extent + 1 == extents_end) {
-                break;
-            }
-
-            /* start new extent */
-            extent++;
-            extent->flags = flags;
-            extent->length = num;
+        if (nbd_extent_array_add(ea, num, flags) < 0) {
+            return 0;
         }
-        offset += num;
-        remaining_bytes -= num;
-    }
-
-    extents_end = extent + 1;
 
-    for (extent = extents; extent < extents_end; extent++) {
-        extent->flags = cpu_to_be32(extent->flags);
-        extent->length = cpu_to_be32(extent->length);
+        offset += num;
+        bytes -= num;
     }
 
-    *bytes -= remaining_bytes;
-    *nb_extents = extents_end - extents;
-
     return 0;
 }
 
-/* nbd_co_send_extents
+/*
+ * nbd_co_send_extents
  *
- * @length is only for tracing purposes (and may be smaller or larger
- * than the client's original request). @last controls whether
- * NBD_REPLY_FLAG_DONE is sent. @extents should already be in
- * big-endian format.
+ * @ea is converted to BE by the function
+ * @last controls whether NBD_REPLY_FLAG_DONE is sent.
  */
 static int nbd_co_send_extents(NBDClient *client, uint64_t handle,
-                               NBDExtent *extents, unsigned int nb_extents,
-                               uint64_t length, bool last,
-                               uint32_t context_id, Error **errp)
+                               NBDExtentArray *ea,
+                               bool last, uint32_t context_id, Error **errp)
 {
     NBDStructuredMeta chunk;
-
     struct iovec iov[] = {
         {.iov_base = &chunk, .iov_len = sizeof(chunk)},
-        {.iov_base = extents, .iov_len = nb_extents * sizeof(extents[0])}
+        {.iov_base = ea->extents, .iov_len = ea->count * sizeof(ea->extents[0])}
     };
 
-    trace_nbd_co_send_extents(handle, nb_extents, context_id, length, last);
+    nbd_extent_array_convert_to_be(ea);
+
+    trace_nbd_co_send_extents(handle, ea->count, context_id, ea->total_length,
+                              last);
     set_be_chunk(&chunk.h, last ? NBD_REPLY_FLAG_DONE : 0,
                  NBD_REPLY_TYPE_BLOCK_STATUS,
                  handle, sizeof(chunk) - sizeof(chunk.h) + iov[1].iov_len);
@@ -2009,39 +2057,27 @@ static int nbd_co_send_block_status(NBDClient *client, uint64_t handle,
 {
     int ret;
     unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS;
-    NBDExtent *extents = g_new(NBDExtent, nb_extents);
-    uint64_t final_length = length;
+    g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents);
 
-    ret = blockstatus_to_extents(bs, offset, &final_length, extents,
-                                 &nb_extents);
+    ret = blockstatus_to_extents(bs, offset, length, ea);
     if (ret < 0) {
-        g_free(extents);
         return nbd_co_send_structured_error(
                 client, handle, -ret, "can't get block status", errp);
     }
 
-    ret = nbd_co_send_extents(client, handle, extents, nb_extents,
-                              final_length, last, context_id, errp);
-
-    g_free(extents);
-
-    return ret;
+    return nbd_co_send_extents(client, handle, ea, last, context_id, errp);
 }
 
 /*
- * Populate @extents from a dirty bitmap. Unless @dont_fragment, the
- * final extent may exceed the original @length. Store in @length the
- * byte length encoded (which may be smaller or larger than the
- * original), and return the number of extents used.
+ * Populate @ea from a dirty bitmap. Unless @dont_fragment, the
+ * final extent may exceed the original @length.
  */
-static unsigned int bitmap_to_extents(BdrvDirtyBitmap *bitmap, uint64_t offset,
-                                      uint64_t *length, NBDExtent *extents,
-                                      unsigned int nb_extents,
-                                      bool dont_fragment)
+static void bitmap_to_extents(BdrvDirtyBitmap *bitmap,
+                              uint64_t offset, uint64_t length,
+                              NBDExtentArray *ea, bool dont_fragment)
 {
     uint64_t begin = offset, end = offset;
-    uint64_t overall_end = offset + *length;
-    unsigned int i = 0;
+    uint64_t overall_end = offset + length;
     BdrvDirtyBitmapIter *it;
     bool dirty;
 
@@ -2050,8 +2086,7 @@ static unsigned int bitmap_to_extents(BdrvDirtyBitmap *bitmap, uint64_t offset,
     it = bdrv_dirty_iter_new(bitmap);
     dirty = bdrv_dirty_bitmap_get_locked(bitmap, offset);
 
-    assert(begin < overall_end && nb_extents);
-    while (begin < overall_end && i < nb_extents) {
+    while (begin < overall_end) {
         bool next_dirty = !dirty;
 
         if (dirty) {
@@ -2071,9 +2106,10 @@ static unsigned int bitmap_to_extents(BdrvDirtyBitmap *bitmap, uint64_t offset,
             end = overall_end;
         }
 
-        extents[i].length = cpu_to_be32(end - begin);
-        extents[i].flags = cpu_to_be32(dirty ? NBD_STATE_DIRTY : 0);
-        i++;
+        if (nbd_extent_array_add(ea, end - begin,
+                                 dirty ? NBD_STATE_DIRTY : 0) < 0) {
+            break;
+        }
         begin = end;
         dirty = next_dirty;
     }
@@ -2083,8 +2119,6 @@ static unsigned int bitmap_to_extents(BdrvDirtyBitmap *bitmap, uint64_t offset,
     bdrv_dirty_bitmap_unlock(bitmap);
 
     assert(offset < end);
-    *length = end - offset;
-    return i;
 }
 
 static int nbd_co_send_bitmap(NBDClient *client, uint64_t handle,
@@ -2092,20 +2126,12 @@ static int nbd_co_send_bitmap(NBDClient *client, uint64_t handle,
                               uint32_t length, bool dont_fragment, bool last,
                               uint32_t context_id, Error **errp)
 {
-    int ret;
     unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS;
-    NBDExtent *extents = g_new(NBDExtent, nb_extents);
-    uint64_t final_length = length;
+    g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents);
 
-    nb_extents = bitmap_to_extents(bitmap, offset, &final_length, extents,
-                                   nb_extents, dont_fragment);
+    bitmap_to_extents(bitmap, offset, length, ea, dont_fragment);
 
-    ret = nbd_co_send_extents(client, handle, extents, nb_extents,
-                              final_length, last, context_id, errp);
-
-    g_free(extents);
-
-    return ret;
+    return nbd_co_send_extents(client, handle, ea, last, context_id, errp);
 }
 
 /* nbd_co_receive_request
-- 
2.21.0

[PATCH v4 09/10] nbd/server: use bdrv_dirty_bitmap_next_dirty_area

[Vladimir Sementsov-Ogievskiy]

Use bdrv_dirty_bitmap_next_dirty_area for bitmap_to_extents. Since
bdrv_dirty_bitmap_next_dirty_area is very accurate in its interface,
we'll never exceed requested region with last chunk. So, we don't need
dont_fragment, and bitmap_to_extents() interface becomes clean enough
to not require any comment.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 nbd/server.c | 59 +++++++++++++++++-----------------------------------
 1 file changed, 19 insertions(+), 40 deletions(-)

diff --git a/nbd/server.c b/nbd/server.c
index 21e665e9e0..0ca9b8b6b8 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -2068,57 +2068,36 @@ static int nbd_co_send_block_status(NBDClient *client, uint64_t handle,
     return nbd_co_send_extents(client, handle, ea, last, context_id, errp);
 }
 
-/*
- * Populate @ea from a dirty bitmap. Unless @dont_fragment, the
- * final extent may exceed the original @length.
- */
+/* Populate @ea from a dirty bitmap. */
 static void bitmap_to_extents(BdrvDirtyBitmap *bitmap,
                               uint64_t offset, uint64_t length,
-                              NBDExtentArray *ea, bool dont_fragment)
+                              NBDExtentArray *es)
 {
-    uint64_t begin = offset, end = offset;
-    uint64_t overall_end = offset + length;
-    BdrvDirtyBitmapIter *it;
-    bool dirty;
+    int64_t start, dirty_start, dirty_count;
+    int64_t end = offset + length;
+    bool full = false;
 
     bdrv_dirty_bitmap_lock(bitmap);
 
-    it = bdrv_dirty_iter_new(bitmap);
-    dirty = bdrv_dirty_bitmap_get_locked(bitmap, offset);
-
-    while (begin < overall_end) {
-        bool next_dirty = !dirty;
-
-        if (dirty) {
-            end = bdrv_dirty_bitmap_next_zero(bitmap, begin, INT64_MAX);
-        } else {
-            bdrv_set_dirty_iter(it, begin);
-            end = bdrv_dirty_iter_next(it);
-        }
-        if (end == -1 || end - begin > UINT32_MAX) {
-            /* Cap to an aligned value < 4G beyond begin. */
-            end = MIN(bdrv_dirty_bitmap_size(bitmap),
-                      begin + UINT32_MAX + 1 -
-                      bdrv_dirty_bitmap_granularity(bitmap));
-            next_dirty = dirty;
-        }
-        if (dont_fragment && end > overall_end) {
-            end = overall_end;
-        }
-
-        if (nbd_extent_array_add(ea, end - begin,
-                                 dirty ? NBD_STATE_DIRTY : 0) < 0) {
+    for (start = offset;
+         bdrv_dirty_bitmap_next_dirty_area(bitmap, start, end, INT32_MAX,
+                                           &dirty_start, &dirty_count);
+         start = dirty_start + dirty_count)
+    {
+        if ((nbd_extent_array_add(es, dirty_start - start, 0) < 0) ||
+            (nbd_extent_array_add(es, dirty_count, NBD_STATE_DIRTY) < 0))
+        {
+            full = true;
             break;
         }
-        begin = end;
-        dirty = next_dirty;
     }
 
-    bdrv_dirty_iter_free(it);
+    if (!full) {
+        /* last non dirty extent */
+        nbd_extent_array_add(es, end - start, 0);
+    }
 
     bdrv_dirty_bitmap_unlock(bitmap);
-
-    assert(offset < end);
 }
 
 static int nbd_co_send_bitmap(NBDClient *client, uint64_t handle,
@@ -2129,7 +2108,7 @@ static int nbd_co_send_bitmap(NBDClient *client, uint64_t handle,
     unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS;
     g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents);
 
-    bitmap_to_extents(bitmap, offset, length, ea, dont_fragment);
+    bitmap_to_extents(bitmap, offset, length, ea);
 
     return nbd_co_send_extents(client, handle, ea, last, context_id, errp);
 }
-- 
2.21.0

[PATCH v4 10/10] block/qcow2-bitmap: use bdrv_dirty_bitmap_next_dirty

[Vladimir Sementsov-Ogievskiy]

store_bitmap_data() loop does bdrv_set_dirty_iter() on each iteration,
which means that we actually don't need iterator itself and we can use
simpler bitmap API.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 block/qcow2-bitmap.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index d41f5d049b..82646c53bd 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -1289,7 +1289,6 @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
     uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap);
     const char *bm_name = bdrv_dirty_bitmap_name(bitmap);
     uint8_t *buf = NULL;
-    BdrvDirtyBitmapIter *dbi;
     uint64_t *tb;
     uint64_t tb_size =
             size_to_clusters(s,
@@ -1308,12 +1307,14 @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
         return NULL;
     }
 
-    dbi = bdrv_dirty_iter_new(bitmap);
     buf = g_malloc(s->cluster_size);
     limit = bytes_covered_by_bitmap_cluster(s, bitmap);
     assert(DIV_ROUND_UP(bm_size, limit) == tb_size);
 
-    while ((offset = bdrv_dirty_iter_next(dbi)) >= 0) {
+    offset = 0;
+    while ((offset = bdrv_dirty_bitmap_next_dirty(bitmap, offset, INT64_MAX))
+           >= 0)
+    {
         uint64_t cluster = offset / limit;
         uint64_t end, write_size;
         int64_t off;
@@ -1356,23 +1357,17 @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
             goto fail;
         }
 
-        if (end >= bm_size) {
-            break;
-        }
-
-        bdrv_set_dirty_iter(dbi, end);
+        offset = end;
     }
 
     *bitmap_table_size = tb_size;
     g_free(buf);
-    bdrv_dirty_iter_free(dbi);
 
     return tb;
 
 fail:
     clear_bitmap_table(bs, tb, tb_size);
     g_free(buf);
-    bdrv_dirty_iter_free(dbi);
     g_free(tb);
 
     return NULL;
-- 
2.21.0

Re: [PATCH v4 01/10] hbitmap: assert that we don't create bitmap larger than INT64_MAX

[Eric Blake]

On 2/5/20 5:20 AM, Vladimir Sementsov-Ogievskiy wrote:
> We have APIs which returns signed int64_t, to be able to return error.

s/returns/return/

> Therefore we can't handle bitmaps with absolute size larger than
> (INT64_MAX+1). Still, keep maximum to be INT64_MAX which is a bit
> safer.
> 
> Note, that bitmaps are used to represent disk images, which can't

s/Note,/Note/

> exceed INT64_MAX anyway.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> Reviewed-by: Max Reitz <mreitz@redhat.com>
> ---
>   util/hbitmap.c | 2 ++
>   1 file changed, 2 insertions(+)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

Re: [PATCH v4 00/10] Further bitmaps improvements

[Vladimir Sementsov-Ogievskiy]

gently ping.. almost all patches has r-b marks (except for 5 and 8)

05.02.2020 14:20, Vladimir Sementsov-Ogievskiy wrote:
> Hi!
> 
> The main feature here is improvement of _next_dirty_area API, which I'm
> going to use then for backup / block-copy.
> 
> Somehow, I thought that it was merged, but seems I even forgot to send
> v4.
> 
> v4:
> 01-04: add Max's r-b
> 05: switch test_hbitmap_next_zero_check_range args to int64_t too
> 06: fix s/UINT64_MAX/INT64_MAX/ in comment to hbitmap_next_dirty
>      s/firt_dirty_off/first_dirty_off/
>      Context changed due to 05 change, but I keep Max's r-b
> 07: simplify parameter check in hbitmap_next_dirty_area
>      drop initialization in hbitmap_sparse_merge
>      add Max's r-b
> 08: commit message tweak
>      refactor converted flag to separated converted_to_be and can_add
>      do not convert to be automatically in nbd_extent_array_add
>      check uint32 overflow in nbd_extent_array_add
> 10: drop extra check from store_bitmap_data, add Max's r-b
> 
> Vladimir Sementsov-Ogievskiy (10):
>    hbitmap: assert that we don't create bitmap larger than INT64_MAX
>    hbitmap: move hbitmap_iter_next_word to hbitmap.c
>    hbitmap: unpublish hbitmap_iter_skip_words
>    hbitmap: drop meta bitmaps as they are unused
>    block/dirty-bitmap: switch _next_dirty_area and _next_zero to int64_t
>    block/dirty-bitmap: add _next_dirty API
>    block/dirty-bitmap: improve _next_dirty_area API
>    nbd/server: introduce NBDExtentArray
>    nbd/server: use bdrv_dirty_bitmap_next_dirty_area
>    block/qcow2-bitmap: use bdrv_dirty_bitmap_next_dirty
> 
>   include/block/dirty-bitmap.h |   9 +-
>   include/qemu/hbitmap.h       |  97 +++--------
>   block/dirty-bitmap.c         |  16 +-
>   block/qcow2-bitmap.c         |  15 +-
>   nbd/server.c                 | 251 ++++++++++++++--------------
>   tests/test-hbitmap.c         | 314 +++++++++++++----------------------
>   util/hbitmap.c               | 134 +++++++++------
>   7 files changed, 375 insertions(+), 461 deletions(-)
> 


-- 
Best regards,
Vladimir

Re: [PATCH v4 05/10] block/dirty-bitmap: switch _next_dirty_area and _next_zero to int64_t

[Max Reitz]

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On 05.02.20 12:20, Vladimir Sementsov-Ogievskiy wrote:
> We are going to introduce bdrv_dirty_bitmap_next_dirty so that same
> variable may be used to store its return value and to be its parameter,
> so it would int64_t.
> 
> Similarly, we are going to refactor hbitmap_next_dirty_area to use
> hbitmap_next_dirty together with hbitmap_next_zero, therefore we want
> hbitmap_next_zero parameter type to be int64_t too.
> 
> So, for convenience update all parameters of *_next_zero and
> *_next_dirty_area to be int64_t.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  include/block/dirty-bitmap.h |  6 +++---
>  include/qemu/hbitmap.h       |  7 +++----
>  block/dirty-bitmap.c         |  6 +++---
>  nbd/server.c                 |  2 +-
>  tests/test-hbitmap.c         | 36 ++++++++++++++++++------------------
>  util/hbitmap.c               | 13 ++++++++-----
>  6 files changed, 36 insertions(+), 34 deletions(-)

Reviewed-by: Max Reitz <mreitz@redhat.com>


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Re: [PATCH v4 00/10] Further bitmaps improvements

[Max Reitz]

[-- Attachment #1.1: Type: text/plain, Size: 369 bytes --]

On 05.02.20 12:20, Vladimir Sementsov-Ogievskiy wrote:
> Hi!
> 
> The main feature here is improvement of _next_dirty_area API, which I'm
> going to use then for backup / block-copy.
> 
> Somehow, I thought that it was merged, but seems I even forgot to send
> v4.

The changes from v3 look good to me, but I’d prefer a review from Eric
on patch 8.

Max


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Re: [PATCH v4 08/10] nbd/server: introduce NBDExtentArray

[Eric Blake]

On 2/5/20 5:20 AM, Vladimir Sementsov-Ogievskiy wrote:
> Introduce NBDExtentArray class, to handle extents list creation in more
> controlled way and with fewer OUT parameters in functions.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>   nbd/server.c | 210 +++++++++++++++++++++++++++++----------------------
>   1 file changed, 118 insertions(+), 92 deletions(-)
> 

> +
> +/* Further modifications of the array after conversion are abandoned */
> +static void nbd_extent_array_convert_to_be(NBDExtentArray *ea)
> +{
> +    int i;
> +
> +    assert(!ea->converted_to_be);

Comment is stale - further modifications after conversion are a bug that 
aborts the program, not abandoned.


>   /*
> - * Populate @extents from block status. Update @bytes to be the actual
> - * length encoded (which may be smaller than the original), and update
> - * @nb_extents to the number of extents used.
> - *
> - * Returns zero on success and -errno on bdrv_block_status_above failure.
> + * Add extent to NBDExtentArray. If extent can't be added (no available space),
> + * return -1.
> + * For safety, when returning -1 for the first time, .can_add is set to false,
> + * further call to nbd_extent_array_add() will crash.

s/further call/so further calls/

> + * (to avoid the situation, when after failing to add an extent (returned -1),
> + * user miss this failure and add another extent, which is successfully added
> + * (array is full, but new extent may be squashed into the last one), then we
> + * have invalid array with skipped extent)

Long comment with nested ().  I'm not sure it adds much value, I think 
it can safely be dropped.  But if it is kept, I suggest:

(this ensures that after a failure, no further extents can accidentally 
change the bounds of the last extent in the array)

>    */
> -static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
> -                                  uint64_t *bytes, NBDExtent *extents,
> -                                  unsigned int *nb_extents)
> +static int nbd_extent_array_add(NBDExtentArray *ea,
> +                                uint32_t length, uint32_t flags)
>   {
> -    uint64_t remaining_bytes = *bytes;
> -    NBDExtent *extent = extents, *extents_end = extents + *nb_extents;
> -    bool first_extent = true;
> +    assert(ea->can_add);
> +
> +    if (!length) {
> +        return 0;
> +    }
> +
> +    /* Extend previous extent if flags are the same */
> +    if (ea->count > 0 && flags == ea->extents[ea->count - 1].flags) {
> +        uint64_t sum = (uint64_t)length + ea->extents[ea->count - 1].length;
> +
> +        if (sum <= UINT32_MAX) {
> +            ea->extents[ea->count - 1].length = sum;
> +            ea->total_length += length;
> +            return 0;
> +        }
> +    }
> +
> +    if (ea->count >= ea->nb_alloc) {
> +        ea->can_add = false;
> +        return -1;
> +    }
> +
> +    ea->total_length += length;
> +    ea->extents[ea->count] = (NBDExtent) {.length = length, .flags = flags};
> +    ea->count++;
>   
> -    assert(*nb_extents);
> -    while (remaining_bytes) {
> +    return 0;
> +}

Looks like you properly addressed my concerns from v3.

Comment changes are trivial, so you can add:

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

Re: [PATCH v4 08/10] nbd/server: introduce NBDExtentArray

[Vladimir Sementsov-Ogievskiy]

26.02.2020 18:06, Eric Blake wrote:
> On 2/5/20 5:20 AM, Vladimir Sementsov-Ogievskiy wrote:
>> Introduce NBDExtentArray class, to handle extents list creation in more
>> controlled way and with fewer OUT parameters in functions.
>>
>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>> ---
>>   nbd/server.c | 210 +++++++++++++++++++++++++++++----------------------
>>   1 file changed, 118 insertions(+), 92 deletions(-)
>>
> 
>> +
>> +/* Further modifications of the array after conversion are abandoned */
>> +static void nbd_extent_array_convert_to_be(NBDExtentArray *ea)
>> +{
>> +    int i;
>> +
>> +    assert(!ea->converted_to_be);
> 
> Comment is stale - further modifications after conversion are a bug that aborts the program, not abandoned.

I always thought that "abandoned" is something that must not be done, so the word works here. But I don't know English well).
May be:

"No further modifications of the array allowed after converting to BE."? Is it better?

Or just drop the comment.


> 
> 
>>   /*
>> - * Populate @extents from block status. Update @bytes to be the actual
>> - * length encoded (which may be smaller than the original), and update
>> - * @nb_extents to the number of extents used.
>> - *
>> - * Returns zero on success and -errno on bdrv_block_status_above failure.
>> + * Add extent to NBDExtentArray. If extent can't be added (no available space),
>> + * return -1.
>> + * For safety, when returning -1 for the first time, .can_add is set to false,
>> + * further call to nbd_extent_array_add() will crash.
> 
> s/further call/so further calls/
> 
>> + * (to avoid the situation, when after failing to add an extent (returned -1),
>> + * user miss this failure and add another extent, which is successfully added
>> + * (array is full, but new extent may be squashed into the last one), then we
>> + * have invalid array with skipped extent)
> 
> Long comment with nested ().  I'm not sure it adds much value, I think it can safely be dropped.  But if it is kept, I suggest:
> 
> (this ensures that after a failure, no further extents can accidentally change the bounds of the last extent in the array)

works for me

> 
>>    */
>> -static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
>> -                                  uint64_t *bytes, NBDExtent *extents,
>> -                                  unsigned int *nb_extents)
>> +static int nbd_extent_array_add(NBDExtentArray *ea,
>> +                                uint32_t length, uint32_t flags)
>>   {
>> -    uint64_t remaining_bytes = *bytes;
>> -    NBDExtent *extent = extents, *extents_end = extents + *nb_extents;
>> -    bool first_extent = true;
>> +    assert(ea->can_add);
>> +
>> +    if (!length) {
>> +        return 0;
>> +    }
>> +
>> +    /* Extend previous extent if flags are the same */
>> +    if (ea->count > 0 && flags == ea->extents[ea->count - 1].flags) {
>> +        uint64_t sum = (uint64_t)length + ea->extents[ea->count - 1].length;
>> +
>> +        if (sum <= UINT32_MAX) {
>> +            ea->extents[ea->count - 1].length = sum;
>> +            ea->total_length += length;
>> +            return 0;
>> +        }
>> +    }
>> +
>> +    if (ea->count >= ea->nb_alloc) {
>> +        ea->can_add = false;
>> +        return -1;
>> +    }
>> +
>> +    ea->total_length += length;
>> +    ea->extents[ea->count] = (NBDExtent) {.length = length, .flags = flags};
>> +    ea->count++;
>> -    assert(*nb_extents);
>> -    while (remaining_bytes) {
>> +    return 0;
>> +}
> 
> Looks like you properly addressed my concerns from v3.
> 
> Comment changes are trivial, so you can add:
> 
> Reviewed-by: Eric Blake <eblake@redhat.com>
> 

Thanks!

-- 
Best regards,
Vladimir

Re: [PATCH v4 08/10] nbd/server: introduce NBDExtentArray

[Eric Blake]

On 2/27/20 6:46 AM, Vladimir Sementsov-Ogievskiy wrote:
> 26.02.2020 18:06, Eric Blake wrote:
>> On 2/5/20 5:20 AM, Vladimir Sementsov-Ogievskiy wrote:
>>> Introduce NBDExtentArray class, to handle extents list creation in more
>>> controlled way and with fewer OUT parameters in functions.
>>>
>>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>>> ---
>>>   nbd/server.c | 210 +++++++++++++++++++++++++++++----------------------
>>>   1 file changed, 118 insertions(+), 92 deletions(-)
>>>
>>
>>> +
>>> +/* Further modifications of the array after conversion are abandoned */
>>> +static void nbd_extent_array_convert_to_be(NBDExtentArray *ea)
>>> +{
>>> +    int i;
>>> +
>>> +    assert(!ea->converted_to_be);
>>
>> Comment is stale - further modifications after conversion are a bug 
>> that aborts the program, not abandoned.
> 
> I always thought that "abandoned" is something that must not be done, so 
> the word works here. But I don't know English well).

Rephrasing my comment, further modifications are "a bug that aborts the 
program", rather than "an ignored action that gets abandoned".

> May be:
> 
> "No further modifications of the array allowed after converting to BE."? 

Yes, that wording is better.

> Is it better?
> 
> Or just drop the comment.

That's also viable; the code reads fairly well even without the comment.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

Re: [PATCH v4 08/10] nbd/server: introduce NBDExtentArray

[Vladimir Sementsov-Ogievskiy]

27.02.2020 16:21, Eric Blake wrote:
> On 2/27/20 6:46 AM, Vladimir Sementsov-Ogievskiy wrote:
>> 26.02.2020 18:06, Eric Blake wrote:
>>> On 2/5/20 5:20 AM, Vladimir Sementsov-Ogievskiy wrote:
>>>> Introduce NBDExtentArray class, to handle extents list creation in more
>>>> controlled way and with fewer OUT parameters in functions.
>>>>
>>>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>>>> ---
>>>>   nbd/server.c | 210 +++++++++++++++++++++++++++++----------------------
>>>>   1 file changed, 118 insertions(+), 92 deletions(-)
>>>>
>>>
>>>> +
>>>> +/* Further modifications of the array after conversion are abandoned */
>>>> +static void nbd_extent_array_convert_to_be(NBDExtentArray *ea)
>>>> +{
>>>> +    int i;
>>>> +
>>>> +    assert(!ea->converted_to_be);
>>>
>>> Comment is stale - further modifications after conversion are a bug that aborts the program, not abandoned.
>>
>> I always thought that "abandoned" is something that must not be done, so the word works here. But I don't know English well).
> 
> Rephrasing my comment, further modifications are "a bug that aborts the program", rather than "an ignored action that gets abandoned".
> 
>> May be:
>>
>> "No further modifications of the array allowed after converting to BE."? 
> 
> Yes, that wording is better.
> 
>> Is it better?
>>
>> Or just drop the comment.
> 
> That's also viable; the code reads fairly well even without the comment.
> 

OK, let's just drop it.

-- 
Best regards,
Vladimir

Re: [PATCH v4 00/10] Further bitmaps improvements

[Vladimir Sementsov-Ogievskiy]

26.02.2020 16:13, Max Reitz wrote:
> On 05.02.20 12:20, Vladimir Sementsov-Ogievskiy wrote:
>> Hi!
>>
>> The main feature here is improvement of _next_dirty_area API, which I'm
>> going to use then for backup / block-copy.
>>
>> Somehow, I thought that it was merged, but seems I even forgot to send
>> v4.
> 
> The changes from v3 look good to me, but I’d prefer a review from Eric
> on patch 8.
> 

Hi!

Could you take it now, or do you prefer me to resend?


-- 
Best regards,
Vladimir

Re: [PATCH v4 00/10] Further bitmaps improvements

[Max Reitz]

[-- Attachment #1.1: Type: text/plain, Size: 904 bytes --]

On 06.03.20 08:45, Vladimir Sementsov-Ogievskiy wrote:
> 26.02.2020 16:13, Max Reitz wrote:
>> On 05.02.20 12:20, Vladimir Sementsov-Ogievskiy wrote:
>>> Hi!
>>>
>>> The main feature here is improvement of _next_dirty_area API, which I'm
>>> going to use then for backup / block-copy.
>>>
>>> Somehow, I thought that it was merged, but seems I even forgot to send
>>> v4.
>>
>> The changes from v3 look good to me, but I’d prefer a review from Eric
>> on patch 8.
>>
> 
> Hi!
> 
> Could you take it now, or do you prefer me to resend?

I understand that you agreed to drop the comment above
bd_extent_array_convert_to_be(), then do the
“s/further call/so further calls/” replacement, and finally replace the
whole four lines Eric has quoted by “(this ensures that after a failure,
no further extents can accidentally change the bounds of the last extent
in the array)”?

Max


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Re: [PATCH v4 00/10] Further bitmaps improvements

[Vladimir Sementsov-Ogievskiy]

10.03.2020 20:17, Max Reitz wrote:
> On 06.03.20 08:45, Vladimir Sementsov-Ogievskiy wrote:
>> 26.02.2020 16:13, Max Reitz wrote:
>>> On 05.02.20 12:20, Vladimir Sementsov-Ogievskiy wrote:
>>>> Hi!
>>>>
>>>> The main feature here is improvement of _next_dirty_area API, which I'm
>>>> going to use then for backup / block-copy.
>>>>
>>>> Somehow, I thought that it was merged, but seems I even forgot to send
>>>> v4.
>>>
>>> The changes from v3 look good to me, but I’d prefer a review from Eric
>>> on patch 8.
>>>
>>
>> Hi!
>>
>> Could you take it now, or do you prefer me to resend?
> 
> I understand that you agreed to drop the comment above
> bd_extent_array_convert_to_be(), then do the
> “s/further call/so further calls/” replacement, and finally replace the
> whole four lines Eric has quoted by “(this ensures that after a failure,
> no further extents can accidentally change the bounds of the last extent
> in the array)”?
> 

Yes, all true.


-- 
Best regards,
Vladimir

Re: [PATCH v4 00/10] Further bitmaps improvements

[Max Reitz]

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On 11.03.20 07:17, Vladimir Sementsov-Ogievskiy wrote:
> 10.03.2020 20:17, Max Reitz wrote:
>> On 06.03.20 08:45, Vladimir Sementsov-Ogievskiy wrote:
>>> 26.02.2020 16:13, Max Reitz wrote:
>>>> On 05.02.20 12:20, Vladimir Sementsov-Ogievskiy wrote:
>>>>> Hi!
>>>>>
>>>>> The main feature here is improvement of _next_dirty_area API, which
>>>>> I'm
>>>>> going to use then for backup / block-copy.
>>>>>
>>>>> Somehow, I thought that it was merged, but seems I even forgot to send
>>>>> v4.
>>>>
>>>> The changes from v3 look good to me, but I’d prefer a review from Eric
>>>> on patch 8.
>>>>
>>>
>>> Hi!
>>>
>>> Could you take it now, or do you prefer me to resend?
>>
>> I understand that you agreed to drop the comment above
>> bd_extent_array_convert_to_be(), then do the
>> “s/further call/so further calls/” replacement, and finally replace the
>> whole four lines Eric has quoted by “(this ensures that after a failure,
>> no further extents can accidentally change the bounds of the last extent
>> in the array)”?
>>
> 
> Yes, all true.

Hm, I could take it then, but on second thought, John is the maintainer
for 8/10 patches, and Eric is for the other two...  So I’m not sure
whether I’m even the right person to do so.

Max


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Re: [PATCH v4 00/10] Further bitmaps improvements

[Vladimir Sementsov-Ogievskiy]

11.03.2020 12:55, Max Reitz wrote:
> On 11.03.20 07:17, Vladimir Sementsov-Ogievskiy wrote:
>> 10.03.2020 20:17, Max Reitz wrote:
>>> On 06.03.20 08:45, Vladimir Sementsov-Ogievskiy wrote:
>>>> 26.02.2020 16:13, Max Reitz wrote:
>>>>> On 05.02.20 12:20, Vladimir Sementsov-Ogievskiy wrote:
>>>>>> Hi!
>>>>>>
>>>>>> The main feature here is improvement of _next_dirty_area API, which
>>>>>> I'm
>>>>>> going to use then for backup / block-copy.
>>>>>>
>>>>>> Somehow, I thought that it was merged, but seems I even forgot to send
>>>>>> v4.
>>>>>
>>>>> The changes from v3 look good to me, but I’d prefer a review from Eric
>>>>> on patch 8.
>>>>>
>>>>
>>>> Hi!
>>>>
>>>> Could you take it now, or do you prefer me to resend?jjjjj
>>>
>>> I understand that you agreed to drop the comment above
>>> bd_extent_array_convert_to_be(), then do the
>>> “s/further call/so further calls/” replacement, and finally replace the
>>> whole four lines Eric has quoted by “(this ensures that after a failure,
>>> no further extents can accidentally change the bounds of the last extent
>>> in the array)”?
>>>
>>
>> Yes, all true.
> 
> Hm, I could take it then, but on second thought, John is the maintainer
> for 8/10 patches, and Eric is for the other two...  So I’m not sure
> whether I’m even the right person to do so.
> 

Hmm, true. Let's wait for John?


-- 
Best regards,
Vladimir

Re: [PATCH v4 00/10] Further bitmaps improvements

[John Snow]

On 3/11/20 9:58 AM, Vladimir Sementsov-Ogievskiy wrote:
> 11.03.2020 12:55, Max Reitz wrote:
>> On 11.03.20 07:17, Vladimir Sementsov-Ogievskiy wrote:
>>> 10.03.2020 20:17, Max Reitz wrote:
>>>> On 06.03.20 08:45, Vladimir Sementsov-Ogievskiy wrote:
>>>>> 26.02.2020 16:13, Max Reitz wrote:
>>>>>> On 05.02.20 12:20, Vladimir Sementsov-Ogievskiy wrote:
>>>>>>> Hi!
>>>>>>>
>>>>>>> The main feature here is improvement of _next_dirty_area API, which
>>>>>>> I'm
>>>>>>> going to use then for backup / block-copy.
>>>>>>>
>>>>>>> Somehow, I thought that it was merged, but seems I even forgot to
>>>>>>> send
>>>>>>> v4.
>>>>>>
>>>>>> The changes from v3 look good to me, but I’d prefer a review from
>>>>>> Eric
>>>>>> on patch 8.
>>>>>>
>>>>>
>>>>> Hi!
>>>>>
>>>>> Could you take it now, or do you prefer me to resend?jjjjj
>>>>
>>>> I understand that you agreed to drop the comment above
>>>> bd_extent_array_convert_to_be(), then do the
>>>> “s/further call/so further calls/” replacement, and finally replace the
>>>> whole four lines Eric has quoted by “(this ensures that after a
>>>> failure,
>>>> no further extents can accidentally change the bounds of the last
>>>> extent
>>>> in the array)”?
>>>>
>>>
>>> Yes, all true.
>>
>> Hm, I could take it then, but on second thought, John is the maintainer
>> for 8/10 patches, and Eric is for the other two...  So I’m not sure
>> whether I’m even the right person to do so.
>>
> 
> Hmm, true. Let's wait for John?
> 
> 

I am *VERY* behind on my email, and this patch series is sitting in my
to-review folder. However, if it's ready to go and reviewed, I'm willing
to merge it, test it, and give it a quick look-over and get you on your way.

--js

Re: [PATCH v4 00/10] Further bitmaps improvements

[Vladimir Sementsov-Ogievskiy]

11.03.2020 20:03, John Snow wrote:
> 
> 
> On 3/11/20 9:58 AM, Vladimir Sementsov-Ogievskiy wrote:
>> 11.03.2020 12:55, Max Reitz wrote:
>>> On 11.03.20 07:17, Vladimir Sementsov-Ogievskiy wrote:
>>>> 10.03.2020 20:17, Max Reitz wrote:
>>>>> On 06.03.20 08:45, Vladimir Sementsov-Ogievskiy wrote:
>>>>>> 26.02.2020 16:13, Max Reitz wrote:
>>>>>>> On 05.02.20 12:20, Vladimir Sementsov-Ogievskiy wrote:
>>>>>>>> Hi!
>>>>>>>>
>>>>>>>> The main feature here is improvement of _next_dirty_area API, which
>>>>>>>> I'm
>>>>>>>> going to use then for backup / block-copy.
>>>>>>>>
>>>>>>>> Somehow, I thought that it was merged, but seems I even forgot to
>>>>>>>> send
>>>>>>>> v4.
>>>>>>>
>>>>>>> The changes from v3 look good to me, but I’d prefer a review from
>>>>>>> Eric
>>>>>>> on patch 8.
>>>>>>>
>>>>>>
>>>>>> Hi!
>>>>>>
>>>>>> Could you take it now, or do you prefer me to resend?jjjjj
>>>>>
>>>>> I understand that you agreed to drop the comment above
>>>>> bd_extent_array_convert_to_be(), then do the
>>>>> “s/further call/so further calls/” replacement, and finally replace the
>>>>> whole four lines Eric has quoted by “(this ensures that after a
>>>>> failure,
>>>>> no further extents can accidentally change the bounds of the last
>>>>> extent
>>>>> in the array)”?
>>>>>
>>>>
>>>> Yes, all true.
>>>
>>> Hm, I could take it then, but on second thought, John is the maintainer
>>> for 8/10 patches, and Eric is for the other two...  So I’m not sure
>>> whether I’m even the right person to do so.
>>>
>>
>> Hmm, true. Let's wait for John?
>>
>>
> 
> I am *VERY* behind on my email, and this patch series is sitting in my
> to-review folder. However, if it's ready to go and reviewed, I'm willing
> to merge it, test it, and give it a quick look-over and get you on your way.
> 

It would be great, if it is convenient for you. Thanks!
All patches are reviewed now by Max or Eric, so, I'd be very glad if this get in 5.0.



-- 
Best regards,
Vladimir

Re: [PATCH v4 00/10] Further bitmaps improvements

[John Snow]

On 3/12/20 1:59 AM, Vladimir Sementsov-Ogievskiy wrote:
> 
> It would be great, if it is convenient for you. Thanks!
> All patches are reviewed now by Max or Eric, so, I'd be very glad if
> this get in 5.0.

Testing and staging right now.

--js

Re: [PATCH v4 00/10] Further bitmaps improvements

[John Snow]

On 3/12/20 1:59 AM, Vladimir Sementsov-Ogievskiy wrote:
> 11.03.2020 20:03, John Snow wrote:
>>
>>
>> On 3/11/20 9:58 AM, Vladimir Sementsov-Ogievskiy wrote:
>>> 11.03.2020 12:55, Max Reitz wrote:
>>>> On 11.03.20 07:17, Vladimir Sementsov-Ogievskiy wrote:
>>>>> 10.03.2020 20:17, Max Reitz wrote:
>>>>>> On 06.03.20 08:45, Vladimir Sementsov-Ogievskiy wrote:
>>>>>>> 26.02.2020 16:13, Max Reitz wrote:
>>>>>>>> On 05.02.20 12:20, Vladimir Sementsov-Ogievskiy wrote:
>>>>>>>>> Hi!
>>>>>>>>>
>>>>>>>>> The main feature here is improvement of _next_dirty_area API,
>>>>>>>>> which
>>>>>>>>> I'm
>>>>>>>>> going to use then for backup / block-copy.
>>>>>>>>>
>>>>>>>>> Somehow, I thought that it was merged, but seems I even forgot to
>>>>>>>>> send
>>>>>>>>> v4.
>>>>>>>>
>>>>>>>> The changes from v3 look good to me, but I’d prefer a review from
>>>>>>>> Eric
>>>>>>>> on patch 8.
>>>>>>>>
>>>>>>>
>>>>>>> Hi!
>>>>>>>
>>>>>>> Could you take it now, or do you prefer me to resend?jjjjj
>>>>>>
>>>>>> I understand that you agreed to drop the comment above
>>>>>> bd_extent_array_convert_to_be(), then do the
>>>>>> “s/further call/so further calls/” replacement, and finally
>>>>>> replace the
>>>>>> whole four lines Eric has quoted by “(this ensures that after a
>>>>>> failure,
>>>>>> no further extents can accidentally change the bounds of the last
>>>>>> extent
>>>>>> in the array)”?
>>>>>>
>>>>>
>>>>> Yes, all true.
>>>>
>>>> Hm, I could take it then, but on second thought, John is the maintainer
>>>> for 8/10 patches, and Eric is for the other two...  So I’m not sure
>>>> whether I’m even the right person to do so.
>>>>
>>>
>>> Hmm, true. Let's wait for John?
>>>
>>>
>>
>> I am *VERY* behind on my email, and this patch series is sitting in my
>> to-review folder. However, if it's ready to go and reviewed, I'm willing
>> to merge it, test it, and give it a quick look-over and get you on
>> your way.
>>
> 
> It would be great, if it is convenient for you. Thanks!
> All patches are reviewed now by Max or Eric, so, I'd be very glad if
> this get in 5.0.
> 
> 
> 

Thanks, applied to my bitmaps tree:

https://github.com/jnsnow/qemu/commits/bitmaps
https://github.com/jnsnow/qemu.git

--js

Re: [PATCH v4 00/10] Further bitmaps improvements

[Vladimir Sementsov-Ogievskiy]

12.03.2020 23:41, John Snow wrote:
> 
> 
> On 3/12/20 1:59 AM, Vladimir Sementsov-Ogievskiy wrote:
>> 11.03.2020 20:03, John Snow wrote:
>>>
>>>
>>> On 3/11/20 9:58 AM, Vladimir Sementsov-Ogievskiy wrote:
>>>> 11.03.2020 12:55, Max Reitz wrote:
>>>>> On 11.03.20 07:17, Vladimir Sementsov-Ogievskiy wrote:
>>>>>> 10.03.2020 20:17, Max Reitz wrote:
>>>>>>> On 06.03.20 08:45, Vladimir Sementsov-Ogievskiy wrote:
>>>>>>>> 26.02.2020 16:13, Max Reitz wrote:
>>>>>>>>> On 05.02.20 12:20, Vladimir Sementsov-Ogievskiy wrote:
>>>>>>>>>> Hi!
>>>>>>>>>>
>>>>>>>>>> The main feature here is improvement of _next_dirty_area API,
>>>>>>>>>> which
>>>>>>>>>> I'm
>>>>>>>>>> going to use then for backup / block-copy.
>>>>>>>>>>
>>>>>>>>>> Somehow, I thought that it was merged, but seems I even forgot to
>>>>>>>>>> send
>>>>>>>>>> v4.
>>>>>>>>>
>>>>>>>>> The changes from v3 look good to me, but I’d prefer a review from
>>>>>>>>> Eric
>>>>>>>>> on patch 8.
>>>>>>>>>
>>>>>>>>
>>>>>>>> Hi!
>>>>>>>>
>>>>>>>> Could you take it now, or do you prefer me to resend?jjjjj
>>>>>>>
>>>>>>> I understand that you agreed to drop the comment above
>>>>>>> bd_extent_array_convert_to_be(), then do the
>>>>>>> “s/further call/so further calls/” replacement, and finally
>>>>>>> replace the
>>>>>>> whole four lines Eric has quoted by “(this ensures that after a
>>>>>>> failure,
>>>>>>> no further extents can accidentally change the bounds of the last
>>>>>>> extent
>>>>>>> in the array)”?
>>>>>>>
>>>>>>
>>>>>> Yes, all true.
>>>>>
>>>>> Hm, I could take it then, but on second thought, John is the maintainer
>>>>> for 8/10 patches, and Eric is for the other two...  So I’m not sure
>>>>> whether I’m even the right person to do so.
>>>>>
>>>>
>>>> Hmm, true. Let's wait for John?
>>>>
>>>>
>>>
>>> I am *VERY* behind on my email, and this patch series is sitting in my
>>> to-review folder. However, if it's ready to go and reviewed, I'm willing
>>> to merge it, test it, and give it a quick look-over and get you on
>>> your way.
>>>
>>
>> It would be great, if it is convenient for you. Thanks!
>> All patches are reviewed now by Max or Eric, so, I'd be very glad if
>> this get in 5.0.
>>
>>
>>
> 
> Thanks, applied to my bitmaps tree:
> 
> https://github.com/jnsnow/qemu/commits/bitmaps
> https://github.com/jnsnow/qemu.git
> 

Thank you!


-- 
Best regards,
Vladimir