diff mbox series

[4 of 4,SMB3] multichannel: try to rebind when reconnecting a channel

Message ID CAH2r5ms6z3ApsMhCBCh5kOO=ezqCwePUpV=dmOUT-HLus5wr5Q@mail.gmail.com (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

Steve French May 31, 2020, 7:45 p.m. UTC 
Here is the final patch of Aurelien's 4 patch series for improving
multichannel performance.  There is still some work to do (on
additional reconnect improvements e.g.) but the performance numbers in
my testing looked really good.

first steps in trying to make channels properly reconnect.

* add cifs_ses_find_chan() function to find the enclosing cifs_chan
  struct it belongs to
* while we have the session lock and are redoing negprot and
  sess.setup in smb2_reconnect() redo the binding of channels.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
diff mbox series

Patch

From 2d82ec2eff07b545c093097bb5bb9043c525a5e6 Mon Sep 17 00:00:00 2001
From: Aurelien Aptel <aaptel@suse.com>
Date: Fri, 24 Apr 2020 16:55:31 +0200
Subject: [PATCH 4/4] cifs: multichannel: try to rebind when reconnecting a
 channel

first steps in trying to make channels properly reconnect.

* add cifs_ses_find_chan() function to find the enclosing cifs_chan
  struct it belongs to
* while we have the session lock and are redoing negprot and
  sess.setup in smb2_reconnect() redo the binding of channels.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
---
 fs/cifs/cifsproto.h |  2 ++
 fs/cifs/sess.c      | 16 ++++++++++++++++
 fs/cifs/smb2pdu.c   | 16 ++++++++++++++++
 3 files changed, 34 insertions(+)

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 8fd44645e9b5..5852d74c1dde 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -592,6 +592,8 @@  void cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc);
 
 extern void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
 				unsigned int *len, unsigned int *offset);
+struct cifs_chan *
+cifs_ses_find_chan(struct cifs_ses *ses, struct TCP_Server_Info *server);
 int cifs_try_adding_channels(struct cifs_ses *ses);
 int cifs_ses_add_channel(struct cifs_ses *ses,
 				struct cifs_server_iface *iface);
diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index 9a426db21fae..ae6a8125e8cf 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -150,6 +150,22 @@  int cifs_try_adding_channels(struct cifs_ses *ses)
 	return ses->chan_count - old_chan_count;
 }
 
+/*
+ * If server is a channel of ses, return the corresponding enclosing
+ * cifs_chan otherwise return NULL.
+ */
+struct cifs_chan *
+cifs_ses_find_chan(struct cifs_ses *ses, struct TCP_Server_Info *server)
+{
+	int i;
+
+	for (i = 0; i < ses->chan_count; i++) {
+		if (ses->chans[i].server == server)
+			return &ses->chans[i];
+	}
+	return NULL;
+}
+
 int
 cifs_ses_add_channel(struct cifs_ses *ses, struct cifs_server_iface *iface)
 {
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index e41cffd8c95b..341d1b60c5a6 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -355,15 +355,31 @@  smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
 		goto out;
 	}
 
+	/*
+	 * If we are reconnecting an extra channel, bind
+	 */
+	if (server->is_channel) {
+		ses->binding = true;
+		ses->binding_chan = cifs_ses_find_chan(ses, server);
+	}
+
 	rc = cifs_negotiate_protocol(0, tcon->ses);
 	if (!rc && tcon->ses->need_reconnect) {
 		rc = cifs_setup_session(0, tcon->ses, nls_codepage);
 		if ((rc == -EACCES) && !tcon->retry) {
 			rc = -EHOSTDOWN;
+			ses->binding = false;
+			ses->binding_chan = NULL;
 			mutex_unlock(&tcon->ses->session_mutex);
 			goto failed;
 		}
 	}
+	/*
+	 * End of channel binding
+	 */
+	ses->binding = false;
+	ses->binding_chan = NULL;
+
 	if (rc || !tcon->need_reconnect) {
 		mutex_unlock(&tcon->ses->session_mutex);
 		goto out;
-- 
2.20.1