dirty-bitmap: Change bdrv_dirty_iter_next() to report byte offset

Thanks to recent cleanups, most callers were scaling a return value
of sectors into bytes (the exception, in qcow2-bitmap, will be
converted to byte-based iteration later).  Update the interface to
do the scaling internally instead.

In qcow2-bitmap, the code was specifically checking for an error
return of -1.  To avoid a regression, we either have to make sure
we continue to return -1 (rather than a scaled -512) on error, or
we have to fix the caller to treat all negative values as error
rather than just one magic value.  It's easy enough to make both
changes at the same time, even though either one in isolation
would work.

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>

diff --git a/block/backup.c b/block/backup.c
index ac9c0187172b6f602734808c3ed7b5433a159ba4..06ddbfd03d1b1bed72dfa5701603fa799ccf2bbe 100644 (file)
--- a/block/backup.c
+++ b/block/backup.c
@@ -375,7 +375,7 @@ static int coroutine_fn backup_run_incremental(BackupBlockJob *job)
     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) {
+    while ((offset = bdrv_dirty_iter_next(dbi)) >= 0) {
         cluster = offset / job->cluster_size;
 
         /* Fake progress updates for any clusters we skipped */

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 84509476bab2f3223325360ab2d24e3a7dd2d63b..e451916187a5d8fb7d39c7452cb9f64c4a72a158 100644 (file)
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -503,7 +503,8 @@ void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter)
 
 int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter)
 {
-    return hbitmap_iter_next(&iter->hbi);
+    int64_t ret = hbitmap_iter_next(&iter->hbi);
+    return ret < 0 ? -1 : ret * BDRV_SECTOR_SIZE;
 }
 
 /* Called within bdrv_dirty_bitmap_lock..unlock */

diff --git a/block/mirror.c b/block/mirror.c
index 0c705e0b4ff8c0b4965b100b458760657f7cd5dc..de0a02778c65b72e807f59481e6ed4fb2c9c95b7 100644 (file)
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -336,10 +336,10 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
     int max_io_bytes = MAX(s->buf_size / MAX_IN_FLIGHT, MAX_IO_BYTES);
 
     bdrv_dirty_bitmap_lock(s->dirty_bitmap);
-    offset = bdrv_dirty_iter_next(s->dbi) * BDRV_SECTOR_SIZE;
+    offset = bdrv_dirty_iter_next(s->dbi);
     if (offset < 0) {
         bdrv_set_dirty_iter(s->dbi, 0);
-        offset = bdrv_dirty_iter_next(s->dbi) * BDRV_SECTOR_SIZE;
+        offset = bdrv_dirty_iter_next(s->dbi);
         trace_mirror_restart_iter(s, bdrv_get_dirty_count(s->dirty_bitmap) *
                                   BDRV_SECTOR_SIZE);
         assert(offset >= 0);
@@ -370,11 +370,11 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
             break;
         }
 
-        next_dirty = bdrv_dirty_iter_next(s->dbi) * BDRV_SECTOR_SIZE;
+        next_dirty = bdrv_dirty_iter_next(s->dbi);
         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);
-            next_dirty = bdrv_dirty_iter_next(s->dbi) * BDRV_SECTOR_SIZE;
+            next_dirty = bdrv_dirty_iter_next(s->dbi);
         }
         assert(next_dirty == next_offset);
         nb_chunks++;

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index 90756cf5610861f7fb7d9285a5761f9ef9d7c015..2d8dcba3e8612a33589c2716b2696963edabc47a 100644 (file)
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -1109,7 +1109,7 @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
     sbc = limit >> BDRV_SECTOR_BITS;
     assert(DIV_ROUND_UP(bm_size, limit) == tb_size);
 
-    while ((sector = bdrv_dirty_iter_next(dbi)) != -1) {
+    while ((sector = bdrv_dirty_iter_next(dbi) >> BDRV_SECTOR_BITS) >= 0) {
         uint64_t cluster = sector / sbc;
         uint64_t end, write_size;
         int64_t off;