On Mon, 2019-08-19 at 12:25 +0000, Rantala, Tommi T. (Nokia - FI/Espoo) wrote: > Hello, > > I have two VMs, exporting some directories in one VM: > # cat /etc/exports > /mnt 192.168.1.0/24(ro,fsid=0,no_subtree_check,sync) > /mnt/export > 192.168.1.0/24(rw,no_root_squash,sync,no_wdelay,no_subtree_check) > [...] Are /mnt and /mnt/export on different filesystems? If not, then your server configuration is pretty much guaranteed to be broken, with conflicting sets of rules being imposed on /mnt/export. I'm guessing that is the case, because I'm not seeing any 'nohide' or 'crossmnt' entries above. > > And NFS mounting in the second VM: > # grep nfs /proc/mounts > server:/export /mnt/export nfs4 > rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255, > acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,nordirplus, > proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.11, > local_lock=none,addr=192.168.1.10 0 0 > [...] > > If I keep some file descriptor open for several minutes in the second > VM, > for example by running this: > # sleep 10m >/mnt/export/test > > Then result is that the NFS mount stops responding: the sleep process > never finished but is "forever" stuck in (killable) D state, and any > I/O > attempt from other processes in /mnt/export never finish. > It's always reproducible with this sleep command. > To recover the mountpoint I need to reboot the second VM. > > Kernel version is 5.3.0-rc4 in both VMs. > Also reproducible with 4.14.x and 4.19.x > > # ps aux|grep sleep > root 2524 0.0 0.0 5900 688 pts/0 D 14:04 0:00 > sleep 5m > > # grep -C100 nfs /proc/*/stack > /proc/2524/stack:[<0>] nfs4_do_close+0x87d/0xb20 [nfsv4] > /proc/2524/stack:[<0>] __put_nfs_open_context+0x297/0x4f0 [nfs] > /proc/2524/stack:[<0>] nfs_file_release+0xbe/0xf0 [nfs] > /proc/2524/stack-[<0>] __fput+0x1df/0x690 > /proc/2524/stack-[<0>] task_work_run+0x123/0x1b0 > /proc/2524/stack-[<0>] exit_to_usermode_loop+0x121/0x140 > /proc/2524/stack-[<0>] do_syscall_64+0x2d1/0x370 > /proc/2524/stack-[<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > -- > /proc/561/stack-[<0>] __rpc_execute+0x692/0xb10 [sunrpc] > /proc/561/stack-[<0>] rpc_run_task+0x45f/0x5d0 [sunrpc] > /proc/561/stack:[<0>] nfs4_call_sync_sequence+0x12a/0x210 [nfsv4] > /proc/561/stack:[<0>] _nfs4_proc_getattr+0x19a/0x200 [nfsv4] > /proc/561/stack:[<0>] nfs4_proc_getattr+0xda/0x230 [nfsv4] > /proc/561/stack:[<0>] __nfs_revalidate_inode+0x2ed/0x7a0 [nfs] > /proc/561/stack:[<0>] nfs_do_access+0x605/0xd00 [nfs] > /proc/561/stack:[<0>] nfs_permission+0x500/0x5e0 [nfs] > /proc/561/stack-[<0>] inode_permission+0x2dd/0x3f0 > /proc/561/stack-[<0>] link_path_walk.part.60+0x681/0xe40 > /proc/561/stack-[<0>] path_lookupat.isra.63+0x1af/0x850 > /proc/561/stack-[<0>] filename_lookup.part.79+0x165/0x360 > /proc/561/stack-[<0>] vfs_statx+0xb9/0x140 > /proc/561/stack-[<0>] __do_sys_newstat+0x77/0xd0 > /proc/561/stack-[<0>] do_syscall_64+0x9a/0x370 > /proc/561/stack-[<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > In dmesg of second VM sometimes nfs complaints are seen: > > [ 386.362897] nfs: server xyz not responding, still trying > > Any ideas what's going wrong here...? > The 'server not responding' implies that there is a network connection issue. Does 'netstat -nt | grep :2049' show a correctly established TCP connection between the client and server VMs? -- Trond Myklebust Linux NFS client maintainer, Hammerspace trond.myklebust@xxxxxxxxxxxxxxx
