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 da...@fromorbit.com ------------------------------------------------------------------------------ Dive into the World of Parallel Programming! The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
