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

Pull request

# gpg: Signature made Wed 16 Jan 2019 01:00:25 GMT
# gpg:                using RSA key 7DEF8106AAFC390E
# gpg: Good signature from "John Snow (John Huston) <jsnow@redhat.com>"
# Primary key fingerprint: FAEB 9711 A12C F475 812F  18F2 88A9 064D 1835 61EB
#      Subkey fingerprint: F9B7 ABDB BCAC DF95 BE76  CBD0 7DEF 8106 AAFC 390E

* remotes/jnsnow/tags/bitmaps-pull-request:
  Revert "hbitmap: Add @advance param to hbitmap_iter_next()"
  Revert "test-hbitmap: Add non-advancing iter_next tests"
  Revert "block/dirty-bitmap: Add bdrv_dirty_iter_next_area"
  block/mirror: fix and improve do_sync_target_write
  tests: add tests for hbitmap_next_dirty_area
  dirty-bitmap: add bdrv_dirty_bitmap_next_dirty_area
  tests: add tests for hbitmap_next_zero with specified end parameter
  dirty-bitmap: improve bdrv_dirty_bitmap_next_zero

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

3 files changed, 21 insertions, 69 deletions

diff --git a/block/backup.c b/block/backup.c
index b829b251eb..435414e964 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -385,7 +385,7 @@ static int coroutine_fn backup_run_incremental(BackupBlockJob *job)
     HBitmapIter hbi;
 
     hbitmap_iter_init(&hbi, job->copy_bitmap, 0);
-    while ((cluster = hbitmap_iter_next(&hbi, true)) != -1) {
+    while ((cluster = hbitmap_iter_next(&hbi)) != -1) {
         do {
             if (yield_and_check(job)) {
                 return 0;
@@ -422,7 +422,8 @@ static void backup_incremental_init_copy_bitmap(BackupBlockJob *job)
             break;
         }
 
-        offset = bdrv_dirty_bitmap_next_zero(job->sync_bitmap, offset);
+        offset = bdrv_dirty_bitmap_next_zero(job->sync_bitmap, offset,
+                                             UINT64_MAX);
         if (offset == -1) {
             hbitmap_set(job->copy_bitmap, cluster, end - cluster);
             break;
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 6b688394e4..00ea36f554 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -515,62 +515,7 @@ void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter)
 
 int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter)
 {
-    return hbitmap_iter_next(&iter->hbi, true);
-}
-
-/**
- * Return the next consecutively dirty area in the dirty bitmap
- * belonging to the given iterator @iter.
- *
- * @max_offset: Maximum value that may be returned for
- *              *offset + *bytes
- * @offset:     Will contain the start offset of the next dirty area
- * @bytes:      Will contain the length of the next dirty area
- *
- * Returns: True if a dirty area could be found before max_offset
- *          (which means that *offset and *bytes then contain valid
- *          values), false otherwise.
- *
- * Note that @iter is never advanced if false is returned.  If an area
- * is found (which means that true is returned), it will be advanced
- * past that area.
- */
-bool bdrv_dirty_iter_next_area(BdrvDirtyBitmapIter *iter, uint64_t max_offset,
-                               uint64_t *offset, int *bytes)
-{
-    uint32_t granularity = bdrv_dirty_bitmap_granularity(iter->bitmap);
-    uint64_t gran_max_offset;
-    int64_t ret;
-    int size;
-
-    if (max_offset == iter->bitmap->size) {
-        /* If max_offset points to the image end, round it up by the
-         * bitmap granularity */
-        gran_max_offset = ROUND_UP(max_offset, granularity);
-    } else {
-        gran_max_offset = max_offset;
-    }
-
-    ret = hbitmap_iter_next(&iter->hbi, false);
-    if (ret < 0 || ret + granularity > gran_max_offset) {
-        return false;
-    }
-
-    *offset = ret;
-    size = 0;
-
-    assert(granularity <= INT_MAX);
-
-    do {
-        /* Advance iterator */
-        ret = hbitmap_iter_next(&iter->hbi, true);
-        size += granularity;
-    } while (ret + granularity <= gran_max_offset &&
-             hbitmap_iter_next(&iter->hbi, false) == ret + granularity &&
-             size <= INT_MAX - granularity);
-
-    *bytes = MIN(size, max_offset - *offset);
-    return true;
+    return hbitmap_iter_next(&iter->hbi);
 }
 
 /* Called within bdrv_dirty_bitmap_lock..unlock */
@@ -781,9 +726,16 @@ 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)
+int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, uint64_t offset,
+                                    uint64_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)
 {
-    return hbitmap_next_zero(bitmap->bitmap, offset);
+    return hbitmap_next_dirty_area(bitmap->bitmap, offset, bytes);
 }
 
 void bdrv_merge_dirty_bitmap(BdrvDirtyBitmap *dest, const BdrvDirtyBitmap *src,
diff --git a/block/mirror.c b/block/mirror.c
index f0b211a9c8..24ede6fdaa 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1185,25 +1185,23 @@ do_sync_target_write(MirrorBlockJob *job, MirrorMethod method,
                      uint64_t offset, uint64_t bytes,
                      QEMUIOVector *qiov, int flags)
 {
-    BdrvDirtyBitmapIter *iter;
     QEMUIOVector target_qiov;
-    uint64_t dirty_offset;
-    int dirty_bytes;
+    uint64_t dirty_offset = offset;
+    uint64_t dirty_bytes;
 
     if (qiov) {
         qemu_iovec_init(&target_qiov, qiov->niov);
     }
 
-    iter = bdrv_dirty_iter_new(job->dirty_bitmap);
-    bdrv_set_dirty_iter(iter, offset);
-
     while (true) {
         bool valid_area;
         int ret;
 
         bdrv_dirty_bitmap_lock(job->dirty_bitmap);
-        valid_area = bdrv_dirty_iter_next_area(iter, offset + bytes,
-                                               &dirty_offset, &dirty_bytes);
+        dirty_bytes = MIN(offset + bytes - dirty_offset, INT_MAX);
+        valid_area = bdrv_dirty_bitmap_next_dirty_area(job->dirty_bitmap,
+                                                       &dirty_offset,
+                                                       &dirty_bytes);
         if (!valid_area) {
             bdrv_dirty_bitmap_unlock(job->dirty_bitmap);
             break;
@@ -1259,9 +1257,10 @@ do_sync_target_write(MirrorBlockJob *job, MirrorMethod method,
                 break;
             }
         }
+
+        dirty_offset += dirty_bytes;
     }
 
-    bdrv_dirty_iter_free(iter);
     if (qiov) {
         qemu_iovec_destroy(&target_qiov);
     }