Re: [PATCH 11/14] cifs: handle when server starts supporting multichannel

Steve French
2023-11-03T00:44:13Z

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removed cc:stable and changed

> + cifs_dbg(VFS, "server %s supports multichannel now\n",
> + ses->server->hostname);

to`

+ cifs_server_dbg(VFS, "supports
multichannel now\n");

Let me know if that is ok for you. (See attached updated patch)

On Thu, Nov 2, 2023 at 3:28 PM Paulo Alcantara <pc@manguebit.com> wrote:
>
> nspmangalore@gmail.com writes:
>
> > @@ -307,17 +308,41 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
> > tcon->need_reopen_files = true;
> >
> > rc = cifs_tree_connect(0, tcon, nls_codepage);
> > - mutex_unlock(&ses->session_mutex);
> >
> > cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
> > if (rc) {
> > /* If sess reconnected but tcon didn't, something strange ... */
> > + mutex_unlock(&ses->session_mutex);
> > cifs_dbg(VFS, "reconnect tcon failed rc = %d\n", rc);
> > goto out;
> > }
> >
> > - if (smb2_command != SMB2_INTERNAL_CMD)
> > - mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
> > + if (!rc &&
> > + (server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
> > + mutex_unlock(&ses->session_mutex);
> > +
> > + /*
> > + * query server network interfaces, in case they change
> > + */
> > + xid = get_xid();
> > + rc = SMB3_request_interfaces(xid, tcon, false);
> > + free_xid(xid);
> > +
> > + if (rc)
> > + cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
> > + __func__, rc);
> > +
> > + if (ses->chan_max > ses->chan_count &&
> > + !SERVER_IS_CHAN(server)) {
> > + if (ses->chan_count == 1)
> > + cifs_dbg(VFS, "server %s supports multichannel now\n",
> > + ses->server->hostname);
>
> Sorry, forgot to mention that you should call cifs_dbg_server() which
> protects access of @server->hostname as cifsd thread could have it freed
> before you access it.

--
Thanks,

Steve

[-- Attachment #2: 0001-cifs-handle-when-server-starts-supporting-multichann.patch --]
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From d012d89c90a47f1250956ef2d9b515927bcc4ec9 Mon Sep 17 00:00:00 2001
From: Shyam Prasad N <sprasad@microsoft.com>
Date: Mon, 30 Oct 2023 11:00:17 +0000
Subject: [PATCH] cifs: handle when server starts supporting multichannel

When the user mounts with multichannel option, but the
server does not support it, there can be a time in future
where it can be supported.

With this change, such a case is handled.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
---
fs/smb/client/cifsproto.h | 4 ++++
fs/smb/client/connect.c | 6 +++++-
fs/smb/client/smb2pdu.c | 30 +++++++++++++++++++++++++++---
3 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h
index 890ceddae07e..bb3bf3cac828 100644
--- a/fs/smb/client/cifsproto.h
+++ b/fs/smb/client/cifsproto.h
@@ -132,6 +132,10 @@ extern int SendReceiveBlockingLock(const unsigned int xid,
struct smb_hdr *in_buf,
struct smb_hdr *out_buf,
int *bytes_returned);
+
+void
+smb2_query_server_interfaces(struct work_struct *work);
+
void
cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
bool all_channels);
diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 6c7701422d4c..6d6e334a079b 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -116,7 +116,8 @@ static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
return rc;
}

-static void smb2_query_server_interfaces(struct work_struct *work)
+void
+smb2_query_server_interfaces(struct work_struct *work)
{
int rc;
int xid;
@@ -134,6 +135,9 @@ static void smb2_query_server_interfaces(struct work_struct *work)
if (rc) {
cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
__func__, rc);
+
+ if (rc == -EOPNOTSUPP)
+ return;
}

queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index c75a80bb6d9e..3a1651772486 100644
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -163,6 +163,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
int rc = 0;
struct nls_table *nls_codepage = NULL;
struct cifs_ses *ses;
+ int xid;

/*
* SMB2s NegProt, SessSetup, Logoff do not have tcon yet so
@@ -307,17 +308,40 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
tcon->need_reopen_files = true;

rc = cifs_tree_connect(0, tcon, nls_codepage);
- mutex_unlock(&ses->session_mutex);

cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
if (rc) {
/* If sess reconnected but tcon didn't, something strange ... */
+ mutex_unlock(&ses->session_mutex);
cifs_dbg(VFS, "reconnect tcon failed rc = %d\n", rc);
goto out;
}

- if (smb2_command != SMB2_INTERNAL_CMD)
- mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
+ if (!rc &&
+ (server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
+ mutex_unlock(&ses->session_mutex);
+
+ /*
+ * query server network interfaces, in case they change
+ */
+ xid = get_xid();
+ rc = SMB3_request_interfaces(xid, tcon, false);
+ free_xid(xid);
+
+ if (rc)
+ cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
+ __func__, rc);
+
+ if (ses->chan_max > ses->chan_count &&
+ !SERVER_IS_CHAN(server)) {
+ if (ses->chan_count == 1)
+ cifs_server_dbg(VFS, "supports multichannel now\n");
+
+ cifs_try_adding_channels(tcon->cifs_sb, ses);
+ }
+ } else {
+ mutex_unlock(&ses->session_mutex);
+ }

atomic_inc(&tconInfoReconnectCount);
out:
--
2.39.2