Hello, As Hui Wang reported, there is a problem with handling of eject button for read-write media (i.e. CD-RW & DVD-RW). Although these are mounted read-only, block layer thinks they are used read-write (unlike the case when the media is normal CD or DVD disk) and thus blocks the eject button. This appears inconsistent to users and as Hui reports it is a regression against pre-3.0 kernels. Tejun suggested we can always use read-only access when filesystem is going to be used read-only. With iso9660 this would work as it is always read-only. But for udf this doesn't work as it can be used read-write. Whether it is read-only or read-write depends on filesystem features so we cannot tell before reading the disk. The solution I've taken is that we return EACCES if we are asked to mount a filesystem which can be mounted only read-only without MS_RDONLY set (so far we just silently set the MS_RDONLY flag during mount). This is userspace visible change which is why I'm CCing more people than usual. But I'm convinced we should be fine for several reasons: 1) The behavior isn't new - when the media is read-only, userspace will already get EACCES when trying to mount it without MS_RDONLY set. 2) mount(8) retries with MS_RDONLY set when it gets EACCESS. 3) mount(2) manpage documents this behavior. If noone will object to this change, I'll push the patches via my tree to Linus. Honza -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
