[Qemu-devel] [PATCH v8 10/21] parallels: Switch to .bdrv_co_block_status()

[Eric Blake <eblake@redhat.com>]

We are gradually moving away from sector-based interfaces, towards
byte-based.  Update the parallels driver accordingly.  Note that
the internal function block_status() is still sector-based, because
it is still in use by other sector-based functions; but that's okay
because request_alignment is 512 as a result of those functions.
For now, no optimizations are added based on the mapping hint.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>

---
v7: fix bug in *map [Vladimir]
v6: no change
v5: fix pnum when return is 0
v4: rebase to interface tweak, R-b dropped
v3: no change
v2: rebase to mapping parameter; it is ignored, so R-b kept
---
 block/parallels.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/block/parallels.c b/block/parallels.c
index e1e3d80c887..3e952a9c147 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -261,23 +261,31 @@ static coroutine_fn int parallels_co_flush_to_os(BlockDriverState *bs)
 }


-static int64_t coroutine_fn parallels_co_get_block_status(BlockDriverState *bs,
-        int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file)
+static int coroutine_fn parallels_co_block_status(BlockDriverState *bs,
+                                                  bool want_zero,
+                                                  int64_t offset,
+                                                  int64_t bytes,
+                                                  int64_t *pnum,
+                                                  int64_t *map,
+                                                  BlockDriverState **file)
 {
     BDRVParallelsState *s = bs->opaque;
-    int64_t offset;
+    int count;

+    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
     qemu_co_mutex_lock(&s->lock);
-    offset = block_status(s, sector_num, nb_sectors, pnum);
+    offset = block_status(s, offset >> BDRV_SECTOR_BITS,
+                          bytes >> BDRV_SECTOR_BITS, &count);
     qemu_co_mutex_unlock(&s->lock);

+    *pnum = count * BDRV_SECTOR_SIZE;
     if (offset < 0) {
         return 0;
     }

+    *map = offset * BDRV_SECTOR_SIZE;
     *file = bs->file->bs;
-    return (offset << BDRV_SECTOR_BITS) |
-        BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
+    return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
 }

 static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
@@ -782,7 +790,7 @@ static BlockDriver bdrv_parallels = {
     .bdrv_open		= parallels_open,
     .bdrv_close		= parallels_close,
     .bdrv_child_perm          = bdrv_format_default_perms,
-    .bdrv_co_get_block_status = parallels_co_get_block_status,
+    .bdrv_co_block_status     = parallels_co_block_status,
     .bdrv_has_zero_init       = bdrv_has_zero_init_1,
     .bdrv_co_flush_to_os      = parallels_co_flush_to_os,
     .bdrv_co_readv  = parallels_co_readv,
-- 
2.14.3