block: Use blk_make_empty() after commits

bdrv_commit() already has a BlockBackend pointing to the BDS that we
want to empty, it just has the wrong permissions.

qemu-img commit has no BlockBackend pointing to the old backing file
yet, but introducing one is simple.

After this commit, bdrv_make_empty() is the only remaining caller of
BlockDriver.bdrv_make_empty().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200429141126.85159-5-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[kwolf: Fixed up reference output for 098]
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Max Reitz
2020-04-29 16:11:26 +02:00
committed by Kevin Wolf
parent 2b7bbdbdef
commit 2d97fde439
3 changed files with 27 additions and 16 deletions

View File

@@ -1104,11 +1104,20 @@ static int img_commit(int argc, char **argv)
goto unref_backing;
}
if (!drop && bs->drv->bdrv_make_empty) {
ret = bs->drv->bdrv_make_empty(bs);
if (ret) {
error_setg_errno(&local_err, -ret, "Could not empty %s",
filename);
if (!drop) {
BlockBackend *old_backing_blk;
old_backing_blk = blk_new_with_bs(bs, BLK_PERM_WRITE, BLK_PERM_ALL,
&local_err);
if (!old_backing_blk) {
goto unref_backing;
}
ret = blk_make_empty(old_backing_blk, &local_err);
blk_unref(old_backing_blk);
if (ret == -ENOTSUP) {
error_free(local_err);
local_err = NULL;
} else if (ret < 0) {
goto unref_backing;
}
}