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authorKevin Wolf <kwolf@redhat.com>2016-12-16 18:52:37 +0100
committerKevin Wolf <kwolf@redhat.com>2017-02-24 16:09:23 +0100
commit4e4bf5c42c8b2847a90367936a6df6c277f4a76a (patch)
tree2b2003718fbd7652d35daf6bb209db90792ce88f /block/qcow2.c
parent52cdbc5869a3fbbe4d91c83e97dffb212af28ce3 (diff)
downloadqemu-4e4bf5c42c8b2847a90367936a6df6c277f4a76a.tar.gz
block: Attach bs->file only during .bdrv_open()
The way that attaching bs->file worked was a bit unusual in that it was the only child that would be attached to a node which is not opened yet. Because of this, the block layer couldn't know yet which permissions the driver would eventually need. This patch moves the point where bs->file is attached to the beginning of the individual .bdrv_open() implementations, so drivers already know what they are going to do with the child. This is also more consistent with how driver-specific children work. For a moment, bdrv_open() gets its own BdrvChild to perform image probing, but instead of directly assigning this BdrvChild to the BDS, it becomes a temporary one and the node name is passed as an option to the drivers, so that they can simply use bdrv_open_child() to create another reference for their own use. This duplicated child for (the not opened yet) bs is not the final state, a follow-up patch will change the image probing code to use a BlockBackend, which is completely independent of bs. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block/qcow2.c')
-rw-r--r--block/qcow2.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/block/qcow2.c b/block/qcow2.c
index 3e1172b325..21e61427eb 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -814,8 +814,8 @@ static int qcow2_update_options(BlockDriverState *bs, QDict *options,
return ret;
}
-static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
- Error **errp)
+static int qcow2_do_open(BlockDriverState *bs, QDict *options, int flags,
+ Error **errp)
{
BDRVQcow2State *s = bs->opaque;
unsigned int len, i;
@@ -1205,6 +1205,18 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
return ret;
}
+static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
+ Error **errp)
+{
+ bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
+ false, errp);
+ if (!bs->file) {
+ return -EINVAL;
+ }
+
+ return qcow2_do_open(bs, options, flags, errp);
+}
+
static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp)
{
BDRVQcow2State *s = bs->opaque;
@@ -1785,7 +1797,7 @@ static void qcow2_invalidate_cache(BlockDriverState *bs, Error **errp)
options = qdict_clone_shallow(bs->options);
flags &= ~BDRV_O_INACTIVE;
- ret = qcow2_open(bs, options, flags, &local_err);
+ ret = qcow2_do_open(bs, options, flags, &local_err);
QDECREF(options);
if (local_err) {
error_propagate(errp, local_err);