Patch "cifs: failure to add channel on iface should bump up weight" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    cifs: failure to add channel on iface should bump up weight

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     cifs-failure-to-add-channel-on-iface-should-bump-up-.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 2876fea2926f1980920d82f985add85a6008e32f
Author: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
Date:   Thu Feb 1 11:15:29 2024 +0000

    cifs: failure to add channel on iface should bump up weight
    
    [ Upstream commit 6aac002bcfd554aff6d3ebb55e1660d078d70ab0 ]
    
    After the interface selection policy change to do a weighted
    round robin, each iface maintains a weight_fulfilled. When the
    weight_fulfilled reaches the total weight for the iface, we know
    that the weights can be reset and ifaces can be allocated from
    scratch again.
    
    During channel allocation failures on a particular channel,
    weight_fulfilled is not incremented. If a few interfaces are
    inactive, we could end up in a situation where the active
    interfaces are all allocated for the total_weight, and inactive
    ones are all that remain. This can cause a situation where
    no more channels can be allocated further.
    
    This change fixes it by increasing weight_fulfilled, even when
    channel allocation failure happens. This could mean that if
    there are temporary failures in channel allocation, the iface
    weights may not strictly be adhered to. But that's still okay.
    
    Fixes: a6d8fb54a515 ("cifs: distribute channels across interfaces based on speed")
    Signed-off-by: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
    Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/smb/client/sess.c b/fs/smb/client/sess.c
index 62596299a396..a20a5d0836dc 100644
--- a/fs/smb/client/sess.c
+++ b/fs/smb/client/sess.c
@@ -263,6 +263,8 @@ int cifs_try_adding_channels(struct cifs_ses *ses)
 					 &iface->sockaddr,
 					 rc);
 				kref_put(&iface->refcount, release_iface);
+				/* failure to add chan should increase weight */
+				iface->weight_fulfilled++;
 				continue;
 			}