Hi Vivek, My sincere apologies - it turns out I *was* running on xfs with ftype=0. Someone in the office had moved docker's storage without me noticing. Apologies to all whose time I wasted. Regards, Daniel Vivek Goyal <vgoyal@xxxxxxxxxx> writes: > On Tue, May 17, 2016 at 10:15:21AM +0200, Miklos Szeredi wrote: >> On Tue, May 17, 2016 at 8:28 AM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: >> > On Mon, May 16, 2016 at 09:07:27AM -0400, Vivek Goyal wrote: >> >> So it became clear that we need a check at mount time to make sure >> >> d_type is supported otherwise error out. This will require users to >> >> do mkfs.xfs with ftype=1 to make progress. >> >> >> >> I think new defaults for mkfs.xfs are such that ftype=1 is set. I am >> >> not sure which version that change was made in. >> > >> > Dumb question - can we end up with empty workdir at that point? Because >> > if we do, the check would appear to return a false negative, no matter >> > what fs supports... >> >> ovl_workdir_create() creates a subdirectory of workdir ("work") so >> workdir itself won't be empty after that. If somebody else messes >> with workdir, then we are screwed anyway. > > Right. Initially I was creating a directory of my own and later realized > that ovl_workdir_create() already creates one. > > Having said that, what happens when ovl_workdir_create() fails and we > mount overlayfs read only. In that case I think we will conclude that > underlying fs does not support d_type and mounting will fail. > > Any thoughts, on how to handle this failure path better? > > Daniel, > > Yesterday Eric Sandeen told me that I can run "xfs_info <mount-point>" to > figure out if ftype is 0 or 1. You might want to run "xfs_info /" and > ensure ftype=0 in your case and overlay is not detecting it wrong. > > Thanks > Vivek -- 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