dirty-bitmap: Set iterator start by offset, not sector

All callers to bdrv_dirty_iter_new() passed 0 for their initial
starting point, drop that parameter.

Most callers to bdrv_set_dirty_iter() were scaling a byte offset to
a sector number; the exception qcow2-bitmap will be converted later
to use byte rather than sector iteration.  Move the scaling to occur
internally to dirty bitmap code instead, so that callers now pass
in bytes.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/backup.c

@@ -372,7 +372,7 @@ static int coroutine_fn backup_run_incremental(BackupBlockJob *job)
 
     granularity = bdrv_dirty_bitmap_granularity(job->sync_bitmap);
     clusters_per_iter = MAX((granularity / job->cluster_size), 1);
-    dbi = bdrv_dirty_iter_new(job->sync_bitmap, 0);
+    dbi = bdrv_dirty_iter_new(job->sync_bitmap);
 
     /* Find the next dirty sector(s) */
     while ((offset = bdrv_dirty_iter_next(dbi) * BDRV_SECTOR_SIZE) >= 0) {
@@ -403,8 +403,7 @@ static int coroutine_fn backup_run_incremental(BackupBlockJob *job)
         /* If the bitmap granularity is smaller than the backup granularity,
          * we need to advance the iterator pointer to the next cluster. */
         if (granularity < job->cluster_size) {
-            bdrv_set_dirty_iter(dbi,
-                                cluster * job->cluster_size / BDRV_SECTOR_SIZE);
+            bdrv_set_dirty_iter(dbi, cluster * job->cluster_size);
         }
 
         last_cluster = cluster - 1;

block/dirty-bitmap.c

@@ -473,11 +473,10 @@ uint32_t bdrv_dirty_bitmap_granularity(const BdrvDirtyBitmap *bitmap)
     return BDRV_SECTOR_SIZE << hbitmap_granularity(bitmap->bitmap);
 }
 
-BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap,
-                                         uint64_t first_sector)
+BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap)
 {
     BdrvDirtyBitmapIter *iter = g_new(BdrvDirtyBitmapIter, 1);
-    hbitmap_iter_init(&iter->hbi, bitmap->bitmap, first_sector);
+    hbitmap_iter_init(&iter->hbi, bitmap->bitmap, 0);
     iter->bitmap = bitmap;
     bitmap->active_iterators++;
     return iter;
@@ -645,9 +644,9 @@ void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
 /**
  * Advance a BdrvDirtyBitmapIter to an arbitrary offset.
  */
-void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *iter, int64_t sector_num)
+void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *iter, int64_t offset)
 {
-    hbitmap_iter_init(&iter->hbi, iter->hbi.hb, sector_num);
+    hbitmap_iter_init(&iter->hbi, iter->hbi.hb, offset >> BDRV_SECTOR_BITS);
 }
 
 int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap)

block/mirror.c

@@ -373,7 +373,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
         next_dirty = bdrv_dirty_iter_next(s->dbi) * BDRV_SECTOR_SIZE;
         if (next_dirty > next_offset || next_dirty < 0) {
             /* The bitmap iterator's cache is stale, refresh it */
-            bdrv_set_dirty_iter(s->dbi, next_offset >> BDRV_SECTOR_BITS);
+            bdrv_set_dirty_iter(s->dbi, next_offset);
             next_dirty = bdrv_dirty_iter_next(s->dbi) * BDRV_SECTOR_SIZE;
         }
         assert(next_dirty == next_offset);
@@ -796,7 +796,7 @@ static void coroutine_fn mirror_run(void *opaque)
     }
 
     assert(!s->dbi);
-    s->dbi = bdrv_dirty_iter_new(s->dirty_bitmap, 0);
+    s->dbi = bdrv_dirty_iter_new(s->dirty_bitmap);
     for (;;) {
         uint64_t delay_ns = 0;
         int64_t cnt, delta;

block/qcow2-bitmap.c

@@ -1103,7 +1103,7 @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
         return NULL;
     }
 
-    dbi = bdrv_dirty_iter_new(bitmap, 0);
+    dbi = bdrv_dirty_iter_new(bitmap);
     buf = g_malloc(s->cluster_size);
     limit = bytes_covered_by_bitmap_cluster(s, bitmap);
     sbc = limit >> BDRV_SECTOR_BITS;
@@ -1153,7 +1153,7 @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
             break;
         }
 
-        bdrv_set_dirty_iter(dbi, end);
+        bdrv_set_dirty_iter(dbi, end * BDRV_SECTOR_SIZE);
     }
 
     *bitmap_table_size = tb_size;

include/block/dirty-bitmap.h

@@ -44,8 +44,7 @@ void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
 void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
                              int64_t cur_sector, int64_t nr_sectors);
 BdrvDirtyBitmapIter *bdrv_dirty_meta_iter_new(BdrvDirtyBitmap *bitmap);
-BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap,
-                                         uint64_t first_sector);
+BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap);
 void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter);
 
 uint64_t bdrv_dirty_bitmap_serialization_size(const BdrvDirtyBitmap *bitmap,
@@ -80,7 +79,7 @@ void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
 void bdrv_reset_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
                                     int64_t cur_sector, int64_t nr_sectors);
 int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter);
-void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *hbi, int64_t sector_num);
+void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *hbi, int64_t offset);
 int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap);
 int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bitmap);
 void bdrv_dirty_bitmap_truncate(BlockDriverState *bs, int64_t bytes);