On Thu, Jul 08, 2021 at 09:12:09PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong <djwong@xxxxxxxxxx> > > Commit 603f000b15f2 changed xfs_ioctl_setattr_check_extsize to reject an > attempt to set an EXTSZINHERIT extent size hint on a directory with > RTINHERIT set if the hint isn't a multiple of the realtime extent size. > However, I have recently discovered that it is possible to change the > realtime extent size when adding a rt device to a filesystem, which > means that the existence of directories with misaligned inherited hints > is not an accident. > > As a result, it's possible that someone could have set a valid hint and > added an rt volume with a different rt extent size, which invalidates > the ondisk hints. After such a sequence, FSGETXATTR will report a > misaligned hint, which FSSETXATTR will trip over, causing confusion if > the user was doing the usual GET/SET sequence to change some other > attribute. Change xfs_fill_fsxattr to omit the hint if it isn't aligned > properly. Looks sensible, but maybe we need a pr_info_ratelimited to inform the user of this case?
