[PATCH][SMB3] follow on patch to make sure secondary channels use the primary channels hostname

[Steve French <smfrench@gmail.com>]

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See attached.


-- 
Thanks,

Steve

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From 97b422704940b97ea259d97f974ad327f648225b Mon Sep 17 00:00:00 2001
From: Shyam Prasad N <sprasad@microsoft.com>
Date: Wed, 22 Jun 2022 12:36:36 -0500
Subject: [PATCH] smb3: use netname when available on secondary channels

Some servers do not allow null netname contexts, which would cause
multichannel to revert to single channel when mounting to some
servers (e.g. Azure xSMB). The previous patch fixed that, this
patch also fixes the secondary channel case by using the netname
context used for primary channel for the secondary channel.

Fixes: 4c14d7043fede ("cifs: populate empty hostnames for extra channels")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
---
 fs/cifs/smb2pdu.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 5e8c4737b183..12b4dddaedb0 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -543,6 +543,7 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 		      struct TCP_Server_Info *server, unsigned int *total_len)
 {
 	char *pneg_ctxt;
+	char *hostname = NULL;
 	unsigned int ctxt_len, neg_context_count;
 
 	if (*total_len > 200) {
@@ -574,9 +575,15 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 	*total_len += sizeof(struct smb2_posix_neg_context);
 	pneg_ctxt += sizeof(struct smb2_posix_neg_context);
 
-	if (server->hostname && (server->hostname[0] != 0)) {
+	/*
+	 * secondary channels don't have the hostname field populated
+	 * use the hostname field in the primary channel instead
+	 */
+	hostname = CIFS_SERVER_IS_CHAN(server) ?
+		server->primary_server->hostname : server->hostname;
+	if (hostname && (hostname[0] != 0)) {
 		ctxt_len = build_netname_ctxt((struct smb2_netname_neg_context *)pneg_ctxt,
-					server->hostname);
+					      hostname);
 		*total_len += ctxt_len;
 		pneg_ctxt += ctxt_len;
 		neg_context_count = 4;
-- 
2.34.1