block: Convert bdrv_pwrite_zeroes() to BdrvChild

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

block/block-backend.c

@@ -870,6 +870,11 @@ int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
                    flags | BDRV_REQ_ZERO_WRITE);
 }
 
+int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags)
+{
+    return bdrv_make_zero(blk->root, flags);
+}
+
 static void error_callback_bh(void *opaque)
 {
     struct BlockBackendAIOCB *acb = opaque;

block/io.c

@@ -649,7 +649,7 @@ int bdrv_write(BdrvChild *child, int64_t sector_num,
                       true, 0);
 }
 
-int bdrv_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
+int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
                        int count, BdrvRequestFlags flags)
 {
     QEMUIOVector qiov;
@@ -659,7 +659,7 @@ int bdrv_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
     };
 
     qemu_iovec_init_external(&qiov, &iov, 1);
-    return bdrv_prwv_co(bs, offset, &qiov, true,
+    return bdrv_prwv_co(child->bs, offset, &qiov, true,
                         BDRV_REQ_ZERO_WRITE | flags);
 }
 
@@ -672,9 +672,10 @@ int bdrv_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
  *
  * Returns < 0 on error, 0 on success. For error codes see bdrv_write().
  */
-int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
+int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags)
 {
     int64_t target_sectors, ret, nb_sectors, sector_num = 0;
+    BlockDriverState *bs = child->bs;
     BlockDriverState *file;
     int n;
 
@@ -698,7 +699,7 @@ int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
             sector_num += n;
             continue;
         }
-        ret = bdrv_pwrite_zeroes(bs, sector_num << BDRV_SECTOR_BITS,
+        ret = bdrv_pwrite_zeroes(child, sector_num << BDRV_SECTOR_BITS,
                                  n << BDRV_SECTOR_BITS, flags);
         if (ret < 0) {
             error_report("error writing zeroes at sector %" PRId64 ": %s",

block/parallels.c

@@ -210,7 +210,7 @@ static int64_t allocate_clusters(BlockDriverState *bs, int64_t sector_num,
         int ret;
         space += s->prealloc_size;
         if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) {
-            ret = bdrv_pwrite_zeroes(bs->file->bs,
+            ret = bdrv_pwrite_zeroes(bs->file,
                                      s->data_end << BDRV_SECTOR_BITS,
                                      space << BDRV_SECTOR_BITS, 0);
         } else {

block/qcow2-cluster.c

@@ -1752,7 +1752,7 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
                 goto fail;
             }
 
-            ret = bdrv_pwrite_zeroes(bs->file->bs, offset, s->cluster_size, 0);
+            ret = bdrv_pwrite_zeroes(bs->file, offset, s->cluster_size, 0);
             if (ret < 0) {
                 if (!preallocated) {
                     qcow2_free_clusters(bs, offset, s->cluster_size,

block/qcow2.c

@@ -2709,7 +2709,7 @@ static int make_completely_empty(BlockDriverState *bs)
     /* After this call, neither the in-memory nor the on-disk refcount
      * information accurately describe the actual references */
 
-    ret = bdrv_pwrite_zeroes(bs->file->bs, s->l1_table_offset,
+    ret = bdrv_pwrite_zeroes(bs->file, s->l1_table_offset,
                              l1_clusters * s->cluster_size, 0);
     if (ret < 0) {
         goto fail_broken_refcounts;
@@ -2723,7 +2723,7 @@ static int make_completely_empty(BlockDriverState *bs)
      * overwrite parts of the existing refcount and L1 table, which is not
      * an issue because the dirty flag is set, complete data loss is in fact
      * desired and partial data loss is consequently fine as well */
-    ret = bdrv_pwrite_zeroes(bs->file->bs, s->cluster_size,
+    ret = bdrv_pwrite_zeroes(bs->file, s->cluster_size,
                              (2 + l1_clusters) * s->cluster_size, 0);
     /* This call (even if it failed overall) may have overwritten on-disk
      * refcount structures; in that case, the in-memory refcount information

include/block/block.h

@@ -230,9 +230,9 @@ int bdrv_read(BdrvChild *child, int64_t sector_num,
               uint8_t *buf, int nb_sectors);
 int bdrv_write(BdrvChild *child, int64_t sector_num,
                const uint8_t *buf, int nb_sectors);
-int bdrv_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
+int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
                        int count, BdrvRequestFlags flags);
-int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags);
+int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
 int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes);
 int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
 int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes);

include/sysemu/block-backend.h

@@ -124,6 +124,7 @@ int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset,
                                   int count, BdrvRequestFlags flags,
                                   BlockCompletionFunc *cb, void *opaque);
+int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags);
 int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int count);
 int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int count,
                BdrvRequestFlags flags);

qemu-img.c

@@ -1648,7 +1648,7 @@ static int convert_do_copy(ImgConvertState *s)
     if (!s->has_zero_init && !s->target_has_backing &&
         bdrv_can_write_zeroes_with_unmap(blk_bs(s->target)))
     {
-        ret = bdrv_make_zero(blk_bs(s->target), BDRV_REQ_MAY_UNMAP);
+        ret = blk_make_zero(s->target, BDRV_REQ_MAY_UNMAP);
         if (ret == 0) {
             s->has_zero_init = true;
         }