[linux-cifs-client] kernel BUG at /tmp/cifs-2.6-devel/fs/cifs/cifs_dfs_ref.c:274!

[Igor Mammedov]

> I do not remember why BUGON is there,

Well, BUGON there is because overlapped mount over fs root makes impossible to
unmount this mount point any more.
For example:
  mount //srv/share/prefix/path /mnt
  creates root inode with //srv/share path
  but when we try 'ls /mnt' the second lookup on the same inode
  takes into account 'prefix/path' and server returns PATH_UNCOVERED error
  that converts inode into dfs link kind with following it and making
  overlapped mount.
  When we try to unmount it we unmount only last mount but the first one is still
  there. If we try unmount the second time then check on open inodes or whatever
  cause following link again and we have overlapped mount again on top of what want
  to unmount. So we stuck there.

PS:
  If you desperately need to mount your share and do not mind that you will not
  be able to unmount it, then apply patch I've posted here with subj
   "try 3: [PATCH] [CIFS] Fixed parsing of mount options when doing DFS submount"
  and comment out BUG_ON(IS_ROOT(dentry)) in cifs_dfs_ref.c



> I'll be at work in a week and I'll see what could be done.
> 
>> [sorry for not attaching it directly to my earlier email, but I'm not keen
>> on having my hashed password archived for the rest of time...]
>>
>> --
>> .....................................................................
>>  Peter Desnoyers                                  pjd at ccs.neu.edu
>>  Northeastern Computer & Information Science
>>
>>

-- 

Best regards,

-------------------------
Igor Mammedov,
niallain "at" gmail.com