[PATCH 09/11] cifs: account for primary channel in the interface list

[Shyam Prasad N <nspmangalore@gmail.com>]

The refcounting of server interfaces should account
for the primary channel too. Although this is not
strictly necessary, doing so will account for the primary
channel in DebugData.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
---
 fs/cifs/sess.c    | 40 +++++++++++++++++++++++++++++++++++-----
 fs/cifs/smb2ops.c |  6 ++++++
 2 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index 78a7cfa75e91..9b51b2309e9c 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -291,11 +291,6 @@ cifs_chan_update_iface(struct cifs_ses *ses, struct TCP_Server_Info *server)
 
 	spin_lock(&ses->chan_lock);
 	chan_index = cifs_ses_get_chan_index(ses, server);
-	if (!chan_index) {
-		spin_unlock(&ses->chan_lock);
-		return 0;
-	}
-
 	if (ses->chans[chan_index].iface) {
 		old_iface = ses->chans[chan_index].iface;
 		if (old_iface->is_active) {
@@ -318,6 +313,16 @@ cifs_chan_update_iface(struct cifs_ses *ses, struct TCP_Server_Info *server)
 
 	/* then look for a new one */
 	list_for_each_entry(iface, &ses->iface_list, iface_head) {
+		if (!chan_index) {
+			/* if we're trying to get the updated iface for primary channel */
+			if (!cifs_match_ipaddr((struct sockaddr *) &server->dstaddr,
+					       (struct sockaddr *) &iface->sockaddr))
+				continue;
+
+			kref_get(&iface->refcount);
+			break;
+		}
+
 		/* do not mix rdma and non-rdma interfaces */
 		if (iface->rdma_capable != server->rdma)
 			continue;
@@ -344,16 +349,41 @@ cifs_chan_update_iface(struct cifs_ses *ses, struct TCP_Server_Info *server)
 		cifs_dbg(FYI, "unable to find a suitable iface\n");
 	}
 
+	if (!chan_index && !iface) {
+		cifs_dbg(VFS, "unable to get the interface matching: %pIS\n",
+			 &server->dstaddr);
+		spin_unlock(&ses->iface_lock);
+		return 0;
+	}
+
 	/* now drop the ref to the current iface */
 	if (old_iface && iface) {
 		cifs_dbg(FYI, "replacing iface: %pIS with %pIS\n",
 			 &old_iface->sockaddr,
 			 &iface->sockaddr);
+
+		old_iface->num_channels--;
+		if (--old_iface->weight_fulfilled < 0)
+			old_iface->weight_fulfilled = 0;
+		iface->num_channels++;
+		iface->weight_fulfilled++;
+
 		kref_put(&old_iface->refcount, release_iface);
 	} else if (old_iface) {
 		cifs_dbg(FYI, "releasing ref to iface: %pIS\n",
 			 &old_iface->sockaddr);
+
+		old_iface->num_channels--;
+		if (--old_iface->weight_fulfilled < 0)
+			old_iface->weight_fulfilled = 0;
+
 		kref_put(&old_iface->refcount, release_iface);
+	} else if (!chan_index) {
+		/* special case: update interface for primary channel */
+		cifs_dbg(FYI, "referencing primary channel iface: %pIS\n",
+			 &iface->sockaddr);
+		iface->num_channels++;
+		iface->weight_fulfilled++;
 	} else {
 		WARN_ON(!iface);
 		cifs_dbg(FYI, "adding new iface: %pIS\n", &iface->sockaddr);
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index c342a1db33ed..a5e53cb1ac49 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -740,6 +740,7 @@ SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon, bool in_
 	unsigned int ret_data_len = 0;
 	struct network_interface_info_ioctl_rsp *out_buf = NULL;
 	struct cifs_ses *ses = tcon->ses;
+	struct TCP_Server_Info *pserver;
 
 	/* do not query too frequently */
 	if (ses->iface_last_update &&
@@ -764,6 +765,11 @@ SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon, bool in_
 	if (rc)
 		goto out;
 
+	/* check if iface is still active */
+	pserver = ses->chans[0].server;
+	if (pserver && !cifs_chan_is_iface_active(ses, pserver))
+		cifs_chan_update_iface(ses, pserver);
+
 out:
 	kfree(out_buf);
 	return rc;
-- 
2.34.1