I suspect that there is a relationship between this and the queueing
problems we saw with Windows Vista and Windows 7 depending on max
multiplex request size (for cifs).
On Sat, Aug 4, 2012 at 3:51 PM, Pavel Shilovsky <piastryyy@xxxxxxxxx> wrote:
> 2012/8/1 Jeff Layton <jlayton@xxxxxxxxx>:
>> On Wed, 1 Aug 2012 15:37:57 +0200
>> Pavel Shilovsky <piastryyy@xxxxxxxxx> wrote:
>>
>>> 2012/7/31 Jeff Layton <jlayton@xxxxxxxxx>:
>>> > On Mon, 30 Jul 2012 21:17:53 -0400
>>> > Jeff Layton <jlayton@xxxxxxxxxx> wrote:
>>> >
>>> >> On Mon, 30 Jul 2012 23:11:10 +0200
>>> >> Pavel Shilovsky <piastryyy@xxxxxxxxx> wrote:
>>> >>
>>> >> > 2012/7/29 Jeff Layton <jlayton@xxxxxxxxxx>:
>>> >> > > On Fri, 27 Jul 2012 10:05:32 +0400
>>> >> > > Pavel Shilovsky <piastryyy@xxxxxxxxx> wrote:
>>> >> > >
>>> >> > >> 2012/7/27 Jeff Layton <jlayton@xxxxxxxxxx>:
>>> >> > >> > On Fri, 27 Jul 2012 03:57:44 +0400
>>> >> > >> > Pavel Shilovsky <piastryyy@xxxxxxxxx> wrote:
>>> >> > >> >
>>> >> > >> >> 2012/7/25 Jeff Layton <jlayton@xxxxxxxxxx>:
>>> >> > >> >> > We want to send SMBs as "atomically" as possible. Prior to sending any
>>> >> > >> >> > data on the socket, cork it to make sure that no non-full frames go
>>> >> > >> >> > out. Afterward, uncork it to make sure all of the data gets pushed out
>>> >> > >> >> > to the wire.
>>> >> > >> >> >
>>> >> > >> >> > Note that this more or less renders the socket=TCP_NODELAY mount option
>>> >> > >> >> > obsolete. When TCP_CORK and TCP_NODELAY are used on the same socket,
>>> >> > >> >> > TCP_NODELAY is essentially ignored.
>>> >> > >> >> >
>>> >> > >> >> > Acked-by: Pavel Shilovsky <pshilovsky@xxxxxxxxx>
>>> >> > >> >> > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
>>> >> > >> >> > ---
>>> >> > >> >> > fs/cifs/connect.c | 4 ++++
>>> >> > >> >> > fs/cifs/transport.c | 12 ++++++++++++
>>> >> > >> >> > 2 files changed, 16 insertions(+)
>>> >> > >> >> >
>>> >> > >> >> > diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
>>> >> > >> >> > index 6df6fa1..a828a8c 100644
>>> >> > >> >> > --- a/fs/cifs/connect.c
>>> >> > >> >> > +++ b/fs/cifs/connect.c
>>> >> > >> >> > @@ -1676,6 +1676,10 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
>>> >> > >> >> > if (string == NULL)
>>> >> > >> >> > goto out_nomem;
>>> >> > >> >> >
>>> >> > >> >> > + /*
>>> >> > >> >> > + * FIXME: since we now cork/uncork the socket while
>>> >> > >> >> > + * sending, should we deprecate this option?
>>> >> > >> >> > + */
>>> >> > >> >> > if (strnicmp(string, "TCP_NODELAY", 11) == 0)
>>> >> > >> >> > vol->sockopt_tcp_nodelay = 1;
>>> >> > >> >> > break;
>>> >> > >> >> > diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
>>> >> > >> >> > index d93f15d..a3e58b2 100644
>>> >> > >> >> > --- a/fs/cifs/transport.c
>>> >> > >> >> > +++ b/fs/cifs/transport.c
>>> >> > >> >> > @@ -27,6 +27,7 @@
>>> >> > >> >> > #include <linux/net.h>
>>> >> > >> >> > #include <linux/delay.h>
>>> >> > >> >> > #include <linux/freezer.h>
>>> >> > >> >> > +#include <linux/tcp.h>
>>> >> > >> >> > #include <asm/uaccess.h>
>>> >> > >> >> > #include <asm/processor.h>
>>> >> > >> >> > #include <linux/mempool.h>
>>> >> > >> >> > @@ -247,12 +248,23 @@ smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
>>> >> > >> >> > int n_vec = rqst->rq_nvec;
>>> >> > >> >> > unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
>>> >> > >> >> > size_t total_len;
>>> >> > >> >> > + struct socket *ssocket = server->ssocket;
>>> >> > >> >> > + int val = 1;
>>> >> > >> >> >
>>> >> > >> >> > cFYI(1, "Sending smb: smb_len=%u", smb_buf_length);
>>> >> > >> >> > dump_smb(iov[0].iov_base, iov[0].iov_len);
>>> >> > >> >> >
>>> >> > >> >> > + /* cork the socket */
>>> >> > >> >> > + kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
>>> >> > >> >> > + (char *)&val, sizeof(val));
>>> >> > >> >> > +
>>> >> > >> >> > rc = smb_send_kvec(server, iov, n_vec, &total_len);
>>> >> > >> >> >
>>> >> > >> >> > + /* uncork it */
>>> >> > >> >> > + val = 0;
>>> >> > >> >> > + kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
>>> >> > >> >> > + (char *)&val, sizeof(val));
>>> >> > >> >> > +
>>> >> > >> >> > if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
>>> >> > >> >> > cFYI(1, "partial send (wanted=%u sent=%zu): terminating "
>>> >> > >> >> > "session", smb_buf_length + 4, total_len);
>>> >> > >> >> > --
>>> >> > >> >> > 1.7.11.2
>>> >> > >> >> >
>>> >> > >> >> > --
>>> >> > >> >> > To unsubscribe from this list: send the line "unsubscribe linux-cifs" in
>>> >> > >> >> > the body of a message to majordomo@xxxxxxxxxxxxxxx
>>> >> > >> >> > More majordomo info at http://vger.kernel.org/majordomo-info.html
>>> >> > >> >>
>>> >> > >> >> I tested it with SMB2 against Windows 7 server. When iosize is 64K
>>> >> > >> >> everything is ok but when we increase iosize to 1M (by using
>>> >> > >> >> multicredit requests) and the server loses the network connection and
>>> >> > >> >> only reboot helps.
>>> >> > >> >>
>>> >> > >> >> Also if I commented corking/uncorking the socket - everything is ok. I
>>> >> > >> >> think this change needs some more investigation (how does it deals
>>> >> > >> >> with 1M iosize on Samba, etc?)
>>> >> > >> >>
>>> >> > >> >
>>> >> > >> > Hmm, haven't seen that with a 1M iosize with smb1 against samba.
>>> >> > >> >
>>> >> > >> > I'll see if I can reproduce it.
>>> >> > >> >
>>> >> > >> > --
>>> >> > >> > Jeff Layton <jlayton@xxxxxxxxxx>
>>> >> > >>
>>> >> > >> Forgot to mentioned how I reproduce it - dbench with 5 clients.
>>> >> > >>
>>> >> > >
>>> >> > > Ok, I've built a cifs.ko from your smb2-dev-cifs-3.6 branch. Here are my mount options:
>>> >> > >
>>> >> > > //win7.poochiereds.net/export /mnt/win7 cifs rw,relatime,vers=2.1,sec=ntlmsspi,cache=strict,unc=\\win7.poochiereds.net\export,username=testuser,domain=WIN7,uid=0,noforceuid,gid=0,noforcegid,addr=192.168.1.32,file_mode=0755,dir_mode=0755,nounix,serverino,rsize=1048576,wsize=1048576,actimeo=1 0 0
>>> >> >
>>> >> > I don't set rsize and wsize explicitly but I don't think it's related.
>>> >> > On what connection did you test it? I use 100Mbit LAN.
>>> >> >
>>> >>
>>> >> The clients and servers are both KVM guests. I'll give it a go over a
>>> >> physical network tomorrow.
>>> >>
>>> >
>>> > Ok, ran it with client as a KVM guest and the server as win7 running on
>>> > bare metal over a gigE network. It still ran just fine.
>>> >
>>> > So what are the symptoms that you see here? Does dbench just hang? If
>>> > so, could you collect /proc/<pid>/stack from the hung process(es)?
>>> > Maybe that would tell us what's going on...
>>>
>>> Windows 7 server doesn't response to packets after some time running
>>> dbench. Also, I even can't ping google.com from this Windows machine.
>>> It seems that everything ok with dbench and Linux machine.
>>>
>>> So, it looks like Windows server problem on my configuration but of
>>> course seems very strage. I will try this patch with Samba server
>>> further.
>>>
>>> This patch doesn't break things with Windows untill we use multicredit
>>> requests (more than 64K, that are not targeted to 3.6 kernel). But I
>>> am going to target multicredit requests feature for 3.7. May be we
>>> should make cork/nodelay switchable? Or just merge the patchset
>>> without this patch for 3.6 and delay this patch for 3.7 - we will have
>>> much time to investigate this strange behavior?
>>>
>>> Thoughts?
>>>
>>
>> If the server isn't responding then that seems like something is broken
>> on the server. Maybe you have a broken network driver? Do you have any
>> captures?
>
> Now I don't have them but I can collect captures when return from vacations.
>
> --
> Best regards,
> Pavel Shilovsky.
--
Thanks,
Steve
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