Comment # 21 on bug 934202 from Michal Hocko

I have only now noticed this bug. I am not sure this is the same issue or
whether this will be any usefule but let me try at least.

I have encountered the following issue recently. Basically I am doing sshfs for
one directory which is sitting on login.suse.cz nfs. The sshfs connection got
stuck and I managed to reach the limit of ssh connections at login.suse.cz (but
that is not the issue).

sshfs counterparts at login.suse.cz were hanging with the following stacks:
        mhocko   28495  0.0  0.0   5040  1280 ?        Ds   Jun01   0:00
/usr/lib64/ssh/sftp-server
        login:~ # cat /proc/28495/stack
        [<ffffffffa0633a61>] nfs4_handle_exception+0x211/0x3f0 [nfs]
        [<ffffffffa0634958>] nfs4_proc_access+0x58/0x70 [nfs]
        [<ffffffffa06129ba>] nfs_do_access+0x11a/0x1e0 [nfs]
        [<ffffffffa0612c06>] nfs_permission+0x186/0x220 [nfs]
        [<ffffffff8116b3d2>] link_path_walk+0x412/0x8a0
        [<ffffffff8116bf95>] path_lookupat+0x55/0x620
        [<ffffffff8116c58f>] do_path_lookup+0x2f/0xe0
        [<ffffffff8116d53f>] user_path_at_empty+0x9f/0xd0
        [<ffffffff81161e60>] vfs_fstatat+0x50/0xb0
        [<ffffffff81161f4f>] sys_newlstat+0x1f/0x50
        [<ffffffff8146cb92>] system_call_fastpath+0x16/0x1b
        [<00007fcc29ea6df5>] 0x7fcc29ea6df5
        [<ffffffffffffffff>] 0xffffffffffffffff