On Thu, Jan 08, 2015 at 01:21:29PM -0800, Jaegeuk Kim wrote: > On Fri, Jan 09, 2015 at 07:54:16AM +1100, Dave Chinner wrote: > > 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 I should point out that this is really "consistent metadata on disk before shutdown", so it really doesn't matter if your filesystem has a journal or not, it can still be implemented. Perhaps it woul dbe best to rename them for a generic ioctl to FS_GOING_DOWN_SYNC, FS_GOING_DOWN_METADATA_METASYNC and FS_GOING_DOWN_NOSYNC... 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
