Commit 9d5eff78 authored by Shyam Prasad N's avatar Shyam Prasad N Committed by Steve French
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cifs: reset iface weights when we cannot find a candidate 



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: a6d8fb54 ("cifs: distribute channels across interfaces based on speed")
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarShyam Prasad N <sprasad@microsoft.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 59b33fab

fs/smb/client/sess.c

+9 −0
Original line number Diff line number Diff line
@@ -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");

	}