On Thu, Jan 08, 2015 at 02:33:17PM -0600, Eric Sandeen wrote: > On 1/8/15 2:18 PM, Jaegeuk Kim wrote: > > On Thu, Jan 08, 2015 at 01:54:20PM -0600, Eric Sandeen wrote: > >> On 1/8/15 12:10 PM, Jaegeuk Kim wrote: > >>> This patch add an ioctl to shutdown f2fs, which stops all the further block > >>> writes after this point. > >> > >> would it make sense to just re-use the xfs ioctl nr, if the semantics are > >> the same? > > > > The semantics are not same for now. > > In order to reuse xfs ioctl, it needs to support options for flushing logs. > > the xfs iotl has 3 behaviors optional: > > #define XFS_FSOP_GOING_FLAGS_DEFAULT 0x0 /* going down */ > #define XFS_FSOP_GOING_FLAGS_LOGFLUSH 0x1 /* flush log but not data */ > #define XFS_FSOP_GOING_FLAGS_NOLOGFLUSH 0x2 /* don't flush log nor data */ > > if f2fs currently supports a subset, you could just -EOPNOTSUPP on the others. No, just do a default shutdown operation if the semantics cannot be supported. - XFS_FSOP_GOING_FLAGS_DEFAULT == consistent on disk before shutdown + implemented by freeze/thaw/shutdown sequence - XFS_FSOP_GOING_FLAGS_LOGFLUSH == consistent journal on disk before shutdown + implemented by journal flush/shutdown sequence - XFS_FSOP_GOING_FLAGS_NOLOGFLUSH == nothing consistent on disk before shutdown + just a shutdown call. f2fs can at least support XFS_FSOP_GOING_FLAGS_DEFAULT and XFS_FSOP_GOING_FLAGS_NOLOGFLUSH.... > If the semantics are completely different, maybe it shouldn't share the > name at all. ;) The semantics are quite clear and generic - when you look at what they actually mean rather than looking at the implementation. There's no need for new ioctls here. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- 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
