On Mon, Sep 18, 2017 at 05:00:58PM -0500, Eric Sandeen wrote: > On 9/18/17 4:31 PM, Dave Chinner wrote: > > On Mon, Sep 18, 2017 at 09:28:55AM -0600, Jens Axboe wrote: > >> On 09/18/2017 09:27 AM, Christoph Hellwig wrote: > >>> On Mon, Sep 18, 2017 at 08:26:05PM +0530, Abdul Haleem wrote: > >>>> Hi, > >>>> > >>>> A warning is triggered from: > >>>> > >>>> file fs/iomap.c in function iomap_dio_rw > >>>> > >>>> if (ret) > >>>> goto out_free_dio; > >>>> > >>>> ret = invalidate_inode_pages2_range(mapping, > >>>> start >> PAGE_SHIFT, end >> PAGE_SHIFT); > >>>>>> WARN_ON_ONCE(ret); > >>>> ret = 0; > >>>> > >>>> inode_dio_begin(inode); > >>> > >>> This is expected and an indication of a problematic workload - which > >>> may be triggered by a fuzzer. > >> > >> If it's expected, why don't we kill the WARN_ON_ONCE()? I get it all > >> the time running xfstests as well. > > > > Because when a user reports a data corruption, the only evidence we > > have that they are running an app that does something stupid is this > > warning in their syslogs. Tracepoints are not useful for replacing > > warnings about data corruption vectors being triggered. > > Is the full WARN_ON spew really helpful to us, though? Certainly > the user has no idea what it means, and will come away terrified > but none the wiser. > > Would a more informative printk_once() still give us the evidence > without the ZOMG I THINK I OOPSED that a WARN_ON produces? Or do we > want/need the backtrace? Maybe we could state a little more directly what's going on: if (err) printk_once(KERN_INFO "Urk, collision detected between direct IO and page cache, YHL. HAND.\n"); ? 8-) --D > > -Eric > > > It needs to be on by default, bu tI'm sure we can wrap it with > > something like an xfs_alert_tag() type of construct so the tag can > > be set in /proc/fs/xfs/panic_mask to suppress it if testers so > > desire. > > > > Cheers, > > > > Dave. > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-next" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
