applied to cifs-2.6.git for-next pending additional testing and review

On Thu, Jul 17, 2025 at 7:06 AM nspmangalore@gmail.com wrote:

From: Shyam Prasad N sprasad@microsoft.com

We now do a weighted selection of server interfaces when allocating new channels. The weights are decided based on the speed advertised. The fulfilled weight for an interface is a counter that is used to track the interface selection. It should be reset back to zero once all interfaces fulfilling their weight.

In cifs_chan_update_iface, this reset logic was missing. As a result when the server interface list changes, the client may not be able to find a new candidate for other channels after all interfaces have been fulfilled.

Fixes: a6d8fb54a515 ("cifs: distribute channels across interfaces based on speed") Cc: stable@vger.kernel.org Signed-off-by: Shyam Prasad N sprasad@microsoft.com

---

fs/smb/client/sess.c | 9 +++++++++ 1 file changed, 9 insertions(+)

diff --git a/fs/smb/client/sess.c b/fs/smb/client/sess.c index 330bc3d25bad..0a8c2fcc9ded 100644 --- a/fs/smb/client/sess.c +++ b/fs/smb/client/sess.c @@ -332,6 +332,7 @@ cifs_chan_update_iface(struct cifs_ses *ses, struct TCP_Server_Info *server) struct cifs_server_iface *old_iface = NULL; struct cifs_server_iface *last_iface = NULL; struct sockaddr_storage ss;

•   int retry = 0;
  
    spin_lock(&ses->chan_lock);
    chan_index = cifs_ses_get_chan_index(ses, server);
  

@@ -360,6 +361,7 @@ cifs_chan_update_iface(struct cifs_ses *ses, struct TCP_Server_Info *server) return; }

+try_again: last_iface = list_last_entry(&ses->iface_list, struct cifs_server_iface, iface_head); iface_min_speed = last_iface->speed; @@ -397,6 +399,13 @@ cifs_chan_update_iface(struct cifs_ses *ses, struct TCP_Server_Info *server) }

    if (list_entry_is_head(iface, &ses->iface_list, iface_head)) {

•           list_for_each_entry(iface, &ses->iface_list, iface_head)
  

•                   iface->weight_fulfilled = 0;
  

•           /* see if it can be satisfied in second attempt */
  

•           if (!retry++)
  

•                   goto try_again;
  

•           iface = NULL;
            cifs_dbg(FYI, "unable to find a suitable iface\n");
    }
  

-- 2.43.0