On Thu, Sep 15, 2016 at 10:09 AM, Darrick J. Wong <darrick.wong@xxxxxxxxxx> wrote: > On Thu, Sep 15, 2016 at 10:01:03AM -0700, Dan Williams wrote: >> On Thu, Sep 15, 2016 at 1:26 AM, Christoph Hellwig <hch@xxxxxx> wrote: >> > On Wed, Sep 14, 2016 at 11:54:38PM -0700, Dan Williams wrote: >> >> The DAX property, page cache bypass, of a VMA is only detectable via the >> >> vma_is_dax() helper to check the S_DAX inode flag. However, this is >> >> only available internal to the kernel and is a property that userspace >> >> applications would like to interrogate. >> > >> > They have absolutely no business knowing such an implementation detail. >> >> Hasn't that train already left the station with FS_XFLAG_DAX? > > Seeing as FS_IOC_FSGETXATTR is a "generic" ioctl now, why not just > implement it for all the DAX fses and block devices? Aside from xflags, > the other fields are probably all zero for non-xfs (aside from project > quota id I guess). > > (Yeah, sort of awkward, I know...) It would solve the problem at hand, I'll take a look. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>