Am 09.08.2011 14:36, schrieb Markus Armbruster: > Kevin Wolf <kw...@redhat.com> writes: > >> Am 09.08.2011 13:56, schrieb Markus Armbruster: >>> bdrv_is_locked() is about the frontend's media lock. To make this more >>> obvious, my PATCH 29/55 replaces it by bdrv_dev_is_medium_locked(). It >>> does *not* query the backend's lock (which may not even exist!) set by >>> bdrv_set_locked(). >> >> This sounds wrong (the behaviour, not your analysis). Do you plan to >> remove bdrv_dev_is_medium_locked() as well? It is used by IDE and >> scsi-disk (easy to replace) and in eject_device() in blockdev.c. Maybe >> the 'eject' monitor command should be handled by another callback into >> the device. > > Just two users remain after my series: > > * bdrv_info() > > It wants to show the frontend's lock state, and uses > bdrv_dev_is_medium_locked() to get it from the frontend.
bdrv_info() is a nasty reason for keeping this in the block layer. > * eject_device() > > It needs to fail if the frontend has its medium locked. It uses > bdrv_dev_is_medium_locked() to get the lock state from the frontend. > Pseudo code (-f glossed over for simplicity): > > unless frontend has removable media > fail > if frontend medium is not already open > and frontend medium is locked > fail > drop the block driver > > I considered replacing this with "ask the frontend to eject", and then > let the frontend decide whether to order the backend to drop the block > driver. I decided against it, since I need > bdrv_dev_is_medium_locked() anyway for bdrv_info(). Besides, the > series is long enough already. I'm not asking to change it in this series, but in general I think it would be a good change to make. Kevin
