block: introduce bdrv_open_file_child() helper
Almost all drivers call bdrv_open_child() similarly. Let's create a
helper for this.
The only not updated drivers that call bdrv_open_child() to set
bs->file are raw-format and snapshot-access:
raw-format sometimes want to have filtered child but
don't set drv->is_filter to true.
snapshot-access wants only DATA | PRIMARY
Possibly we should implement drv->is_filter_func() handler, to consider
raw-format as filter when it works as filter.. But it's another story.
Note also, that we decrease assignments to bs->file in code: it helps
us restrict modifying this field in further commit.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220726201134.924743-3-vsementsov@yandex-team.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block/blklogwrites.c b/block/blklogwrites.c
index e3c6c40..12b4c3c 100644
--- a/block/blklogwrites.c
+++ b/block/blklogwrites.c
@@ -155,11 +155,8 @@
}
/* Open the file */
- bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
- BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY, false,
- errp);
- if (!bs->file) {
- ret = -EINVAL;
+ ret = bdrv_open_file_child(NULL, options, "file", bs, errp);
+ if (ret < 0) {
goto fail;
}
