Re: [EXTERNAL] Re: [PATCH 4.19 013/247] cifs: Set CIFS_MOUNT_USE_PREFIX_PATH flag on setting cifs_sb->prepath.

[Greg Kroah-Hartman]

On Thu, Apr 08, 2021 at 01:41:05PM +0200, Salvatore Bonaccorso wrote:
> Hi Shyam,
> 
> On Tue, Apr 06, 2021 at 05:01:17PM +0200, Salvatore Bonaccorso wrote:
> > Hi,
> > 
> > On Tue, Apr 06, 2021 at 02:00:48PM +0000, Shyam Prasad wrote:
> > > Hi Greg,
> > > We'll need to debug this further to understand what's going on. 
> > 
> > Greg asked it the same happens with 5.4 as well, I do not know I was
> > not able to test 5.4.y (yet) but only 5.10.y and 4.19.y.
> > > 
> > > Hi Salvatore,
> > > Any chance that you'll be able to provide us the cifsFYI logs from the time of mount failure?
> > > https://wiki.samba.org/index.php/LinuxCIFS_troubleshooting#Enabling_Debugging
> > 
> > Please find it attached. Is this enough information?
> > 
> > The mentioned home DFS link 'home' is a DFS link to
> > msdfs:SECONDHOST\REDACTED on a Samba host.
> > 
> > The mount is triggered as
> > 
> > mount -t cifs //HOSTIP/REDACTED/home /mnt --verbose -o username='REDACTED,domain=DOMAIN'
> 
> So I can confirm the issue is both present in 4.19.185 and 5.4.110
> upstream (without any Debian patches applied, we do not anyway apply
> any cifs related one on top of the respetive upstream version).
> 
> The issue is not present in 5.10.28.
> 
> So I think there are commits as dependency of a738c93fb1c1 ("cifs: Set
> CIFS_MOUNT_USE_PREFIX_PATH flag on setting cifs_sb->prepath.") which
> are required and not applied in the released before 5.10.y which make
> introducing the regression.

Ok, I've dropped this from 5.4 and older kernel trees now, thanks for
the report.

greg k-h