On Mon, Oct 01, 2018 at 07:07:12PM -0700, Darrick J. Wong wrote: > On Tue, Oct 02, 2018 at 02:31:06AM +0100, Al Viro wrote: > > On Mon, Oct 01, 2018 at 03:45:00PM -0700, Darrick J. Wong wrote: > > > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > > > > > Teach callers of inode->i_op->get_link in the vfs code to check for a > > > NULL return value and return an error status instead of blindly > > > dereferencing the returned NULL pointer. > > > > IDGI. If you want it to fail with -EUCLEAN, then by all means return > > it as you would any other error. > > > > I've no problem with "fs image is fucked, return an error". However, > > "fs driver is fucked, paper over that if we'd caught one of the > > symptoms" is a different story. > > This whole thread got started from a suggestion Christoph made about a > patch I had to fix the XFS side to return an error instead of a null > pointer: > > https://www.spinics.net/lists/linux-xfs/msg21372.html Ugh... What should happen for that to trigger? If anything, I would rather validate that somewhere around xfs_setup_iops() *AND* set ->i_link at the same time, killing the whole xfs_vn_get_link_inline() thing (just use simple_get_link() instead)... See another reply for the reasons why such mitigation makes no sense.
