On Mon, Apr 28, 2008 at 07:31:23PM +0900, Takashi Sato wrote:[...]+ /* Initialize semaphore for freeze. */
+ sema_init(&bdev->bd_freeze_sem, 1);
The freezing process is already protected by bd_mount_sem, so I don't
think there's need for another one.
down(&bdev->bd_mount_sem);
sb = get_super(bdev);
I think the protection against double freezes would be better done by
using a trylock on bd_mount_sem.
In fact after that it could be changed
from a semaphore to a simple test_and_set_bit.
error = -ENOTTY;
break;
+
+ case FIFREEZE: {
This would be better to split intot a small helper ala ioctl_fibmap()
+ case FITHAW: {
Same here.