[dm-devel] flood of "dm-X: error: dax access failed" due to 5.9 commit 231609785cbfb

[Verma, Vishal L]

On Thu, 2020-09-03 at 00:40 +0800, Coly Li wrote:
> On 2020/9/3 00:04, Mike Snitzer wrote:
> > 5.9 commit 231609785cbfb ("dax: print error message by pr_info() in
> > __generic_fsdax_supported()") switched from pr_debug() to pr_info().
> > 
> > The justification in the commit header is really inadequate.  If there
> > is a problem that you need to drill in on, repeat the testing after
> > enabling the dynamic debugging.
> > 
> > Otherwise, now all DM devices that aren't layered on DAX capable devices
> > spew really confusing noise to users when they simply activate their
> > non-DAX DM devices:
> > 
> > [66567.129798] dm-6: error: dax access failed (-5)
> > [66567.134400] dm-6: error: dax access failed (-5)
> > [66567.139152] dm-6: error: dax access failed (-5)
> > [66567.314546] dm-2: error: dax access failed (-95)
> > [66567.319380] dm-2: error: dax access failed (-95)
> > [66567.324254] dm-2: error: dax access failed (-95)
> > [66567.479025] dm-2: error: dax access failed (-95)
> > [66567.483713] dm-2: error: dax access failed (-95)
> > [66567.488722] dm-2: error: dax access failed (-95)
> > [66567.494061] dm-2: error: dax access failed (-95)
> > [66567.498823] dm-2: error: dax access failed (-95)
> > [66567.503693] dm-2: error: dax access failed (-95)
> > 
> > commit 231609785cbfb must be reverted.
> > 
> > Please advise, thanks.
> 
> Adrian Huang from Lenovo posted a patch, which titled: dax: do not print
> error message for non-persistent memory block device
> 
> It fixes the issue, but no response for now. Maybe we should take this fix.
> 

Mike, Coly,

I applied Adrians patch, and submitted it - it is already in v5.9-rc3 -
c2affe920b0e dax: do not print error message for non-persistent memory block device