Re: How to cope with two incompatible overlayfs formats out in the wild

2014-11-19 Thread Miklos Szeredi
On Tue, Nov 18, 2014 at 03:28:03PM +0100, Miklos Szeredi wrote: > If we'd have a different filesystem type for the old and new formats, > then that would solve both (checking /proc/filesystems would indicate > which one is supported). > > Unfortunately that would mean having to change "overlayfs"

Re: How to cope with two incompatible overlayfs formats out in the wild

2014-11-19 Thread Miklos Szeredi
On Wed, Nov 19, 2014 at 2:59 AM, Al Viro wrote: > On Tue, Nov 18, 2014 at 03:28:03PM +0100, Miklos Szeredi wrote: > >> So from mainline we need two things: >> >> - when mounting distinguish between old and new format. >> >> - userspace can detect which formats are supported by the kernel. >> >

Re: How to cope with two incompatible overlayfs formats out in the wild

2014-11-18 Thread Al Viro
On Tue, Nov 18, 2014 at 03:28:03PM +0100, Miklos Szeredi wrote: > So from mainline we need two things: > > - when mounting distinguish between old and new format. > > - userspace can detect which formats are supported by the kernel. > > If we'd have a different filesystem type for the old a

Re: How to cope with two incompatible overlayfs formats out in the wild

2014-11-18 Thread Andy Whitcroft
On Tue, Nov 18, 2014 at 03:28:03PM +0100, Miklos Szeredi wrote: > [CC-ing mailing lists, Al and Linus for wider exposure] > > This issue is this: Ubuntu and SUSE carry an "old" format of overlayfs > while mainline has a "new" format. The differences are: > > - whiteouts are represented differen