2015-07-30 21:54:31

by James Harvey

[permalink] [raw]
Subject: NFS with RDMA mounts, but can't actually be used

Running 2 up to date Arch systems, on kernel 4.1.3 (-1 Arch).
nfs-utils 1.3.2 (-6 Arch). 2 Mellanox ConnectX MT25418 cards, using
latest firmware.

Have a working InfiniBand subnet. Able to connect via IPoIB and
InfiniBand protocols. Able to use iSCSI via IPoIB and iSER. Able to
use nfs over IPoIB just fine.

If I use nfs using rdma, I can mount a nfs volume, but any process
that tries to use it hangs. Even "cd" or "ls".

I've tried using a directory being shared from the server that is a
single disk partition with btrfs, so there's no raid involved.


I believe I have everything setup correctly. Kernel modules are
loaded (including mlx4, ib_ipoib, svcrdma on server, xprtrdma on
client.) "rdma 20049" echoed to /proc/fs/nfsd/portlist. Server is
running nfs-server.service.

Server exports the directory using:
/bench 192.168.2.0/24(rw,async,insecure,no_subtree_check)

Client mounts the directory using:
mount -t nfs4 -o rdma,port=20049 192.168.2.1:/bench /ben

It returns from the mount command almost immediately, and with "--verbose" says:
==========
mount.nfs4: timeout set for Thu Jul 30 17:22:26 2015
mount.nfs4: trying text-based options
'rdma,port=20049,vers=4.2,addr=192.168.2.1,clientaddr=192.168.2.2'
==========

After, checking mount shows:
==========
192.168.2.1:/bench on /bench type nfs4
(rw,relatime,vers=4.2,rsize=262144,wsize=262144,namlen=255,hard,proto=rdma,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.2.2,local_lock=none,addr=192.168.2.1)
==========

BUT, the client with sunrpc.nfs_debug=1023, then within 0.1 seconds,
dmesg has overflown and has 8510 lines. Don't think it's supposed to
be that verbose. It seems to be repeating (with seqid changing):
==========
[ 1271.325354] systemd-journald[232]: /dev/kmsg buffer overrun, some
messages lost.
[ 1271.325365] <-- nfs4_proc_bind_conn_to_session status= 0
[ 1271.325370] --> nfs41_setup_sequence
[ 1271.325371] <-- nfs41_setup_sequence slotid=0 seqid=1191326
[ 1271.325375] encode_sequence: sessionid=1438289348:4:5:0
seqid=1191326 slotid=0 max_slotid=0 cache_this=0
[ 1271.325424] nfs41_sequence_done: Error 0 free the slot
[ 1271.325425] nfs41_sequence_call_done rpc_cred ffff880877238240
[ 1271.325425] <-- nfs41_sequence_call_done
[ 1271.325435] --> nfs_put_client({3})
[ 1271.325436] <-- nfs4_proc_sequence status=0
[ 1271.325438] --> nfs4_proc_bind_conn_to_session
[ 1271.325463] systemd-journald[232]: /dev/kmsg buffer overrun, some
messages lost.
==========

The server even with debug=1023 gets no new dmesg during or after the mount.

At this point, "cd /bench" and "ls /bench" hang. Can't strace cd, but
if I strace the ls, I get:
==========
execve("/usr/bin/ls", ["ls", "/bench"], [/* 58 vars */]) = 0
brk(0) = 0x175e000
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=157039, ...}) = 0
mmap(NULL, 157039, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fa524f93000
close(3) = 0
open("/usr/lib/libcap.so.2", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\240\25\0\0\0\0\0\0"...,
832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=17320, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7fa524f92000
mmap(NULL, 2112568, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3,
0) = 0x7fa524b95000
mprotect(0x7fa524b99000, 2093056, PROT_NONE) = 0
mmap(0x7fa524d98000, 4096, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7fa524d98000
close(3) = 0
open("/usr/lib/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\260\10\2\0\0\0\0\0"...,
832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1979984, ...}) = 0
mmap(NULL, 3807760, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3,
0) = 0x7fa5247f3000
mprotect(0x7fa52498c000, 2093056, PROT_NONE) = 0
mmap(0x7fa524b8b000, 24576, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x198000) = 0x7fa524b8b000
mmap(0x7fa524b91000, 14864, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fa524b91000
close(3) = 0
open("/usr/lib/libattr.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0`\24\0\0\0\0\0\0"...,
832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=18736, ...}) = 0
mmap(NULL, 2113912, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3,
0) = 0x7fa5245ee000
mprotect(0x7fa5245f2000, 2093056, PROT_NONE) = 0
mmap(0x7fa5247f1000, 8192, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7fa5247f1000
close(3) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7fa524f91000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7fa524f90000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7fa524f8f000
arch_prctl(ARCH_SET_FS, 0x7fa524f90700) = 0
mprotect(0x7fa524b8b000, 16384, PROT_READ) = 0
mprotect(0x7fa5247f1000, 4096, PROT_READ) = 0
mprotect(0x61c000, 4096, PROT_READ) = 0
mprotect(0x7fa524fba000, 4096, PROT_READ) = 0
munmap(0x7fa524f93000, 157039) = 0
brk(0) = 0x175e000
brk(0x177f000) = 0x177f000
open("/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=1852560, ...}) = 0
mmap(NULL, 1852560, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fa524dca000
close(3) = 0
ioctl(1, TCGETS, {B38400 opost isig icanon echo ...}) = 0
ioctl(1, TIOCGWINSZ, {ws_row=33, ws_col=211, ws_xpixel=0, ws_ypixel=0}) = 0
stat("/bench",
==========

The server even with debug=1023 gets no new dmesg during the ls.

And it never gets past this stat. Strace has to be kill -9'ed. Just
kill doesn't do anything.


2015-07-30 21:56:43

by Chuck Lever III

[permalink] [raw]
Subject: Re: NFS with RDMA mounts, but can't actually be used

Cc: nfs-rdma-devel removed. I think that's a dead list.


On Jul 30, 2015, at 5:54 PM, james harvey <[email protected]> wrote:

> Running 2 up to date Arch systems, on kernel 4.1.3 (-1 Arch).
> nfs-utils 1.3.2 (-6 Arch). 2 Mellanox ConnectX MT25418 cards, using
> latest firmware.
>
> Have a working InfiniBand subnet. Able to connect via IPoIB and
> InfiniBand protocols. Able to use iSCSI via IPoIB and iSER. Able to
> use nfs over IPoIB just fine.
>
> If I use nfs using rdma, I can mount a nfs volume, but any process
> that tries to use it hangs. Even "cd" or "ls".
>
> I've tried using a directory being shared from the server that is a
> single disk partition with btrfs, so there's no raid involved.
>
>
> I believe I have everything setup correctly. Kernel modules are
> loaded (including mlx4, ib_ipoib, svcrdma on server, xprtrdma on
> client.) "rdma 20049" echoed to /proc/fs/nfsd/portlist. Server is
> running nfs-server.service.
>
> Server exports the directory using:
> /bench 192.168.2.0/24(rw,async,insecure,no_subtree_check)
>
> Client mounts the directory using:
> mount -t nfs4 -o rdma,port=20049 192.168.2.1:/bench /ben
>
> It returns from the mount command almost immediately, and with "--verbose" says:
> ==========
> mount.nfs4: timeout set for Thu Jul 30 17:22:26 2015
> mount.nfs4: trying text-based options
> 'rdma,port=20049,vers=4.2,addr=192.168.2.1,clientaddr=192.168.2.2'

Try specifying vers=4.0 explicitly.


> ==========
>
> After, checking mount shows:
> ==========
> 192.168.2.1:/bench on /bench type nfs4
> (rw,relatime,vers=4.2,rsize=262144,wsize=262144,namlen=255,hard,proto=rdma,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.2.2,local_lock=none,addr=192.168.2.1)
> ==========
>
> BUT, the client with sunrpc.nfs_debug=1023, then within 0.1 seconds,
> dmesg has overflown and has 8510 lines. Don't think it's supposed to
> be that verbose. It seems to be repeating (with seqid changing):
> ==========
> [ 1271.325354] systemd-journald[232]: /dev/kmsg buffer overrun, some
> messages lost.
> [ 1271.325365] <-- nfs4_proc_bind_conn_to_session status= 0
> [ 1271.325370] --> nfs41_setup_sequence
> [ 1271.325371] <-- nfs41_setup_sequence slotid=0 seqid=1191326
> [ 1271.325375] encode_sequence: sessionid=1438289348:4:5:0
> seqid=1191326 slotid=0 max_slotid=0 cache_this=0
> [ 1271.325424] nfs41_sequence_done: Error 0 free the slot
> [ 1271.325425] nfs41_sequence_call_done rpc_cred ffff880877238240
> [ 1271.325425] <-- nfs41_sequence_call_done
> [ 1271.325435] --> nfs_put_client({3})
> [ 1271.325436] <-- nfs4_proc_sequence status=0
> [ 1271.325438] --> nfs4_proc_bind_conn_to_session
> [ 1271.325463] systemd-journald[232]: /dev/kmsg buffer overrun, some
> messages lost.
> ==========
>
> The server even with debug=1023 gets no new dmesg during or after the mount.
>
> At this point, "cd /bench" and "ls /bench" hang. Can't strace cd, but
> if I strace the ls, I get:
> ==========
> execve("/usr/bin/ls", ["ls", "/bench"], [/* 58 vars */]) = 0
> brk(0) = 0x175e000
> access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
> open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
> fstat(3, {st_mode=S_IFREG|0644, st_size=157039, ...}) = 0
> mmap(NULL, 157039, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fa524f93000
> close(3) = 0
> open("/usr/lib/libcap.so.2", O_RDONLY|O_CLOEXEC) = 3
> read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\240\25\0\0\0\0\0\0"...,
> 832) = 832
> fstat(3, {st_mode=S_IFREG|0644, st_size=17320, ...}) = 0
> mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
> 0) = 0x7fa524f92000
> mmap(NULL, 2112568, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3,
> 0) = 0x7fa524b95000
> mprotect(0x7fa524b99000, 2093056, PROT_NONE) = 0
> mmap(0x7fa524d98000, 4096, PROT_READ|PROT_WRITE,
> MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7fa524d98000
> close(3) = 0
> open("/usr/lib/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
> read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\260\10\2\0\0\0\0\0"...,
> 832) = 832
> fstat(3, {st_mode=S_IFREG|0755, st_size=1979984, ...}) = 0
> mmap(NULL, 3807760, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3,
> 0) = 0x7fa5247f3000
> mprotect(0x7fa52498c000, 2093056, PROT_NONE) = 0
> mmap(0x7fa524b8b000, 24576, PROT_READ|PROT_WRITE,
> MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x198000) = 0x7fa524b8b000
> mmap(0x7fa524b91000, 14864, PROT_READ|PROT_WRITE,
> MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fa524b91000
> close(3) = 0
> open("/usr/lib/libattr.so.1", O_RDONLY|O_CLOEXEC) = 3
> read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0`\24\0\0\0\0\0\0"...,
> 832) = 832
> fstat(3, {st_mode=S_IFREG|0755, st_size=18736, ...}) = 0
> mmap(NULL, 2113912, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3,
> 0) = 0x7fa5245ee000
> mprotect(0x7fa5245f2000, 2093056, PROT_NONE) = 0
> mmap(0x7fa5247f1000, 8192, PROT_READ|PROT_WRITE,
> MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7fa5247f1000
> close(3) = 0
> mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
> 0) = 0x7fa524f91000
> mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
> 0) = 0x7fa524f90000
> mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
> 0) = 0x7fa524f8f000
> arch_prctl(ARCH_SET_FS, 0x7fa524f90700) = 0
> mprotect(0x7fa524b8b000, 16384, PROT_READ) = 0
> mprotect(0x7fa5247f1000, 4096, PROT_READ) = 0
> mprotect(0x61c000, 4096, PROT_READ) = 0
> mprotect(0x7fa524fba000, 4096, PROT_READ) = 0
> munmap(0x7fa524f93000, 157039) = 0
> brk(0) = 0x175e000
> brk(0x177f000) = 0x177f000
> open("/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
> fstat(3, {st_mode=S_IFREG|0644, st_size=1852560, ...}) = 0
> mmap(NULL, 1852560, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fa524dca000
> close(3) = 0
> ioctl(1, TCGETS, {B38400 opost isig icanon echo ...}) = 0
> ioctl(1, TIOCGWINSZ, {ws_row=33, ws_col=211, ws_xpixel=0, ws_ypixel=0}) = 0
> stat("/bench",
> ==========
>
> The server even with debug=1023 gets no new dmesg during the ls.
>
> And it never gets past this stat. Strace has to be kill -9'ed. Just
> kill doesn't do anything.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

--
Chuck Lever




2015-07-30 23:06:42

by Michael Darling

[permalink] [raw]
Subject: Re: NFS with RDMA mounts, but can't actually be used

On Thu, Jul 30, 2015 at 9:56 PM, Chuck Lever <[email protected]> wrote:
> Cc: nfs-rdma-devel removed. I think that's a dead list.

Looks like you're right. My initial mail to it bounced back.

> Try specifying vers=4.0 explicitly.

This works! Also, vers=4.1 fails with the same behavior in my original post.

Does this mean there's a bug in vers 4.1-4.2, or something else?

2015-07-30 23:23:46

by Chuck Lever III

[permalink] [raw]
Subject: Re: NFS with RDMA mounts, but can't actually be used


On Jul 30, 2015, at 7:06 PM, Michael Darling <[email protected]> wrote:

> On Thu, Jul 30, 2015 at 9:56 PM, Chuck Lever <[email protected]> wrote:
>> Cc: nfs-rdma-devel removed. I think that's a dead list.
>
> Looks like you're right. My initial mail to it bounced back.
>
>> Try specifying vers=4.0 explicitly.
>
> This works! Also, vers=4.1 fails with the same behavior in my original post.
>
> Does this mean there's a bug in vers 4.1-4.2, or something else?

NFS/RDMA is not yet working with NFSv4.1 and NFSv4.2. It's a
known issue.

If no "vers=" mount option is specified, mount.nfs will start
negotiating now at 4.2. It used to start at 4.0.

--
Chuck Lever