block: Require auto-read-only for existing fallbacks

Some block drivers have traditionally changed their node to read-only
mode without asking the user. This behaviour has been marked deprecated
since 2.11, expecting users to provide an explicit read-only=on option.

Now that we have auto-read-only=on, enable these drivers to make use of
the option.

This is the only use of bdrv_set_read_only(), so we can make it a bit
more specific and turn it into a bdrv_apply_auto_read_only() that is
more convenient for drivers to use.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Kevin Wolf 2018-10-12 11:27:41 +02:00
parent a51b9c4862
commit eaa2410f1e
7 changed files with 51 additions and 68 deletions

View file

@ -105,23 +105,18 @@ static int bochs_open(BlockDriverState *bs, QDict *options, int flags,
struct bochs_header bochs;
int ret;
/* No write support yet */
ret = bdrv_apply_auto_read_only(bs, NULL, errp);
if (ret < 0) {
return ret;
}
bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
false, errp);
if (!bs->file) {
return -EINVAL;
}
if (!bdrv_is_read_only(bs)) {
error_report("Opening bochs images without an explicit read-only=on "
"option is deprecated. Future versions will refuse to "
"open the image instead of automatically marking the "
"image read-only.");
ret = bdrv_set_read_only(bs, true, errp); /* no write support yet */
if (ret < 0) {
return ret;
}
}
ret = bdrv_pread(bs->file, 0, &bochs, sizeof(bochs));
if (ret < 0) {
return ret;