Hi Salvatore, Thanks for reminding me. I had to do some reading to reply to this one. The situation right now is this: The patch "cifs: Set CIFS_MOUNT_USE_PREFIX_PATH flag on setting cifs_sb->prepath." has been reverted. Which means that the DFS bug which you originally faced will not be seen. Hi Greg, Here are the two patches which I'm referring to: 1. cifs: Set CIFS_MOUNT_USE_PREFIX_PATH flag on setting cifs_sb->prepath. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.12&id=a738c93fb1c17e386a09304b517b1c6b2a6a5a8b This fixed an issue when two cifs mount points shared a common prefix in the path which they mounted from the same server. The patch was marked for CC:stable considering that this fix can be important for some users. However, there was a dependent change for DFS scenario, which is present in the Linus' mainline tree, but were not marked for CC:stable, so missing from the stable trees. Due to the missing dependent changes, DFS users faced issues with pre-5.11 kernels, and this patch was reverted in the stable trees. 2. Due to a major change that went into the 5.11 kernel (the new mount API support), the code differs significantly, and the missing patch cannot be applied to pre-5.11 trees. Hence, Paulo submitted the attached patch (cifs: fix prefix path in dfs mounts), which fixes this for pre-5.11 kernels. I was referring to these two patches to be applied to all stable trees. Salvatore has verified that with both patches applied, the DFS scenario starts working again. @Paulo Alcantara Please add if I missed something here. Regards, Shyam -----Original Message----- From: Salvatore Bonaccorso <salvatore.bonaccorso@xxxxxxxxx> On Behalf Of Salvatore Bonaccorso Sent: Saturday, May 8, 2021 6:52 PM To: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Shyam Prasad <Shyam.Prasad@xxxxxxxxxxxxx>; pc <pc@xxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; stable@xxxxxxxxxxxxxxx; Aurelien Aptel <aaptel@xxxxxxxx>; Steven French <Steven.French@xxxxxxxxxxxxx>; Sasha Levin <sashal@xxxxxxxxxx> Subject: Re: [EXTERNAL] Re: [PATCH 4.19 013/247] cifs: Set CIFS_MOUNT_USE_PREFIX_PATH flag on setting cifs_sb->prepath. Shyam, Paulo, On Fri, Apr 23, 2021 at 09:42:35AM +0200, Greg Kroah-Hartman wrote: > On Thu, Apr 22, 2021 at 03:36:07PM +0000, Shyam Prasad wrote: > > Hi Salvatore and Santiago, > > > > Thanks for testing this out. > > > > @Greg Kroah-Hartman: The reverted patch used in combination with Paulo's fix seems to fix both use cases. > > Can we have both these taken in on stable kernels? Paulo's patch is needed only for kernels 5.10 and older. > > I do not know what "both" is here at all. > > Please resubmit all of the needed commits in a format that I can apply > them in, and I will be glad to review them and queue them up. > > Note, patches that are not in Linus's tree better be documented really > really really really well for why that is not so... Did you saw the ping from Greg? Otherwise I think the situation as it is now for the older stable series is probably just as fine as it is now with the repsective original commit reverted. Regards, Salvatore
Attachment:
0001-cifs-fix-prefix-path-in-dfs-mounts.patch
Description: 0001-cifs-fix-prefix-path-in-dfs-mounts.patch
