[PATCH 1/4] cifs: cifs_chan_is_iface_active should be called with chan_lock held

[nspmangalore@gmail.com]

From: Shyam Prasad N <sprasad@microsoft.com>

cifs_chan_is_iface_active checks the channels of a session to see
if the associated iface is active. This should always happen
with chan_lock held. However, these two callers of this function
were missing this locking.

This change makes sure the function calls are protected with
proper locking.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
---
 fs/smb/client/connect.c | 7 +++++--
 fs/smb/client/smb2ops.c | 7 ++++++-
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 8b7cffba1ad5..3052a208c6ca 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -232,10 +232,13 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 	spin_lock(&cifs_tcp_ses_lock);
 	list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
 		/* check if iface is still active */
-		if (!cifs_chan_is_iface_active(ses, server))
+		spin_lock(&ses->chan_lock);
+		if (!cifs_chan_is_iface_active(ses, server)) {
+			spin_unlock(&ses->chan_lock);
 			cifs_chan_update_iface(ses, server);
+			spin_lock(&ses->chan_lock);
+		}
 
-		spin_lock(&ses->chan_lock);
 		if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server)) {
 			spin_unlock(&ses->chan_lock);
 			continue;
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index 441d144bd712..104c58df0368 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -784,9 +784,14 @@ SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon, bool in_
 		goto out;
 
 	/* check if iface is still active */
+	spin_lock(&ses->chan_lock);
 	pserver = ses->chans[0].server;
-	if (pserver && !cifs_chan_is_iface_active(ses, pserver))
+	if (pserver && !cifs_chan_is_iface_active(ses, pserver)) {
+		spin_unlock(&ses->chan_lock);
 		cifs_chan_update_iface(ses, pserver);
+		spin_lock(&ses->chan_lock);
+	}
+	spin_unlock(&ses->chan_lock);
 
 out:
 	kfree(out_buf);
-- 
2.34.1