panic ffs_truncate3 (maybe fuse being evil)

[Konstantin Belousov]

On Mon, Jan 18, 2016 at 11:25:16PM -0500, Rick Macklem wrote:
> Kostik wrote:
> > On Sat, Jan 16, 2016 at 06:20:31PM -0500, Rick Macklem wrote:
> > > Kostik wrote:
> > > > Was IO_EXT flag passed to the ffs_truncate() invocation where the
> > > > assert ffs_truncate3 fired ?
> > > > 
> > > Yes. The only call to UFS_TRUNCATE() in ufs_inactive() specified both
> > > IO_EXT | IO_NORMAL.
> > 
> > Please try this.
> > 
> Still happens. I put the old panic test in, but with a printf() instead
> of panic() and the printf() happens with this patch.
> Btw, whenever I've looked, the entry is on the clean list.
> No other panics happen and the file system fsck's fine after the test run.

I thought that you posted a stand-alone program which triggered the issue
on non-SU mounts, but I cannot find it.  Does such program exist, or this
is just me misremembering ?