Re: [PATCH] [REGRESSION] ovl: Handle ENOSYS when fileattr support is missing in lower/upper fs

[Jonathan Katz <jkatz@eitmlabs.org>]

Confirmed bindfs interaction:

Based on your bindfs comment I redid my configuration as follows:
ORIGINAL  (FAILS):
    FS1 - exports "/Data"  (nfs)
    FS2 - Mounts "/Data", does a bindfs, does an overlay

TEST (SUCCEEDS):
    FS1 - does a bindfs and exports a series of directories:
              # bindfs -u 5007, -g 5007 /Data /Data-jiajun
              /etc/exports:
                    /Data  machine.org(ro,sync,no_subtree_check)
                    /Data-jiajun machine.org(ro,fsid=12,sync,no_subtree_check)
     FS2 - used to do bindfs to make the lowers, but, now mounts
"/Data-jiajun" as the lower
               FS2 then does the overlay and samba share.
                It would not let me do the 2nd export if I did not
include the fsid entry....

WOOT WOOT.


Not an ideal solution as I have to make changes to 2 servers in order
to accomplish my goal :/.








On Tue, Mar 14, 2023 at 7:43 PM Jonathan Katz <jkatz@eitmlabs.org> wrote:
>
> On Thu, Mar 9, 2023 at 7:31 AM Miklos Szeredi <miklos@szeredi.hu> wrote:
> >
> > On Tue, 7 Mar 2023 at 18:14, Jonathan Katz <jkatz@eitmlabs.org> wrote:
> > >
> > > On Tue, Mar 7, 2023 at 12:38 AM Miklos Szeredi <miklos@szeredi.hu> wrote:
> > > >
> > > > On Tue, 7 Mar 2023 at 02:12, Jonathan Katz <jkatz@eitmlabs.org> wrote:
> > > > >
> > > > > Hi all,
> > > > >
> > > > > In pursuing this issue, I downloaded the kernel source to see if I
> > > > > could debug it further.  In so doing, it looks like Christian's patch
> > > > > was never committed to the main source tree (sorry if my terminology
> > > > > is wrong).  This is up to and including the 6.3-rc1.  I could also
> > > > > find no mention of the fix in the log.
> > > > >
> > > > > I am trying to manually apply this patch now, but, I am wondering if
> > > > > there was some reason that it was not applied (e.g. it introduces some
> > > > > instability?)?
> > > >
> > > > It's fixing the bug in the wrong place, i.e. it's checking for an
> > > > -ENOSYS return from vfs_fileattr_get(), but that return value is not
> > > > valid at that point.
> > > >
> > > > The right way to fix this bug is to prevent -ENOSYS from being
> > > > returned in the first place.
> > > >
> > > > Commit 02c0cab8e734 ("fuse: ioctl: translate ENOSYS") fixes one of
> > > > those bugs, but of course it's possible that I missed something in
> > > > that fix.
> > > >
> > > > Can you please first verify that an upstream kernel (>v6.0) can also
> > > > reproduce this issue?
> > >
> > > Got ya.  that makes a lot of sense, thank you.
> > >
> > > I have confirmed that I continue to get the error with 6.2 .
> > > quick summary of the lowerdir:
> > >    server ---- NFS(ro) ---- > client "/nfs"
> > >    client "/nfs" --- bindfs(uidmap) --- > client "/lower"
> >
> > Can you please run bindfs in debugging mode (-d) and send the
> > resulting log after reproducing the issue?
> >
> > Thanks,
> > Miklos
>
> OUCH -- MY LAST EMAIL WAS REJECTED FOR BEING TOO BIG
> I HOPE THAT I AM SUMMARIZING THE RELEVANT INFORMATION HERE:
>
>
> Hi Miklos, thank you.... I am sorry for the delay.
>
> The log is somewhat long and was sent in a separate email.
>
> I broke up the log into entries to try to match the chronology of actions:
>    * ENTRY 1 nfs mount the external drive
>    * ENTRY 2 perform the bind fs
>    * ENTRY 3 perform the overlay
>    * ENTRY 4 restart smb
>    * ENTRY 5 mount the filesystem on a windows box
>    * ENTRY 6 performing some navigation on the windows file explorer
>    * ENTRY 7 attempt to open a data file with the windows application.
>
> The only place that generated a kernel error in dmesg was at ENTRY 7.
>
> Because the logs are so big, I tried to parse them, I may have made a
> mistake or omitted information -- if you think so, as mentioned, the
> full bindfs logs were sent separately
>
>
> Here is my attempt to parse out the errors associated with this dmesg entry:
>
> [ 1925.705908] overlayfs: failed to retrieve lower fileattr (8020
> MeOHH2O RecoverySample1-20221216-A-JJL-WebinarHilic10C-TOF-TT54-Neg-1632.d/chromatography-data.sqlite,
> err=-38)
>
> --
> unique: 1550, opcode: GETXATTR (22), nodeid: 71, insize: 73, pid: 3458
> getxattr /eimstims1/deleteme2/8020 MeOHH2O
> RecoverySample1-20221216-A-JJL-WebinarHilic10C-TOF-TT54-Neg-1632.d/chromatography-data-pre.sqlite
> trusted.overlay.metacopy 0
>    unique: 1550, error: -95 (Operation not supported), outsize: 16
> --
> unique: 3922, opcode: GETXATTR (22), nodeid: 71, insize: 72, pid: 3458
> getxattr /eimstims1/deleteme2/8020 MeOHH2O
> RecoverySample1-20221216-A-JJL-WebinarHilic10C-TOF-TT54-Neg-1632.d/chromatography-data-pre.sqlite
> system.posix_acl_access 132
>    unique: 3922, error: -95 (Operation not supported), outsize: 16
> --
> unique: 3954, opcode: GETXATTR (22), nodeid: 71, insize: 72, pid: 3458
> getxattr /eimstims1/deleteme2/8020 MeOHH2O
> RecoverySample1-20221216-A-JJL-WebinarHilic10C-TOF-TT54-Neg-1632.d/chromatography-data-pre.sqlite
> system.posix_acl_access 132
>    unique: 3954, error: -95 (Operation not supported), outsize: 16
> --
> unique: 3960, opcode: GETXATTR (22), nodeid: 71, insize: 72, pid: 3458
> getxattr /eimstims1/deleteme2/8020 MeOHH2O
> RecoverySample1-20221216-A-JJL-WebinarHilic10C-TOF-TT54-Neg-1632.d/chromatography-data-pre.sqlite
> system.posix_acl_access 132
>    unique: 3960, error: -95 (Operation not supported), outsize: 16
>
>
> Thank you again!
>
> -Jonathan