fdctrl_change_cb() gets called on a virtual media change via monitor.
It would be nice if host device block drivers called it on physical
media change, but they don't.
bdrv_media_changed() lets you poll for media change, but it returns
"don't know" except with block driver "host_floppy".
FDrive member media_changed gets set on device initialization and by
fdctrl_change_cb(), and cleared by fdctrl_media_changed(). Thus, it's
set on first entry to fdctrl_media_changed() since device
initialization or virtual media change.
fdctrl_media_changed() ignores media_changed unless
bdrv_media_changed() returns "don't know". If we change media via
monitor (setting media_changed), and the new media's block driver
returns 0, we lose. Fortunately, "host_floppy" always returns 1 on
first call. Brittle. Clean it up not to rely on it.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
if (!drv->bs)
return 0;
- ret = bdrv_media_changed(drv->bs);
- if (ret < 0) {
- ret = drv->media_changed;
+ if (drv->media_changed) {
+ drv->media_changed = 0;
+ ret = 1;
+ } else {
+ ret = bdrv_media_changed(drv->bs);
+ if (ret < 0) {
+ ret = 0; /* we don't know, assume no */
+ }
}
- drv->media_changed = 0;
if (ret) {
fd_revalidate(drv);
}