diff mbox series

cifs: after disabling multichannel, mark tcon for reconnect

Message ID 20231229113007.39009-1-sprasad@microsoft.com (mailing list archive)
State New, archived
Headers show
Series cifs: after disabling multichannel, mark tcon for reconnect | expand

Commit Message

Shyam Prasad N Dec. 29, 2023, 11:30 a.m. UTC
From: Shyam Prasad N <sprasad@microsoft.com>

Once the server disables multichannel for an active multichannel
session, on the following reconnect, the client would reduce
the number of channels to 1. However, it could be the case that
the tree connect was active on one of these disabled channels.
This results in an unrecoverable state.

This change fixes that by making sure that whenever a channel
is being terminated, the session and tcon are marked for
reconnect too. This could mean a few redundant tree connect
calls to the server, but considering that this is not a frequent
event, we should be okay.

Fixes: ee1d21794e55 ("cifs: handle when server stops supporting multichannel")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
---
 fs/smb/client/connect.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

Comments

Shyam Prasad N Dec. 29, 2023, 11:32 a.m. UTC | #1
On Fri, Dec 29, 2023 at 5:00 PM <nspmangalore@gmail.com> wrote:
>
> From: Shyam Prasad N <sprasad@microsoft.com>
>
> Once the server disables multichannel for an active multichannel
> session, on the following reconnect, the client would reduce
> the number of channels to 1. However, it could be the case that
> the tree connect was active on one of these disabled channels.
> This results in an unrecoverable state.
>
> This change fixes that by making sure that whenever a channel
> is being terminated, the session and tcon are marked for
> reconnect too. This could mean a few redundant tree connect
> calls to the server, but considering that this is not a frequent
> event, we should be okay.
>
> Fixes: ee1d21794e55 ("cifs: handle when server stops supporting multichannel")
> Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
> ---
>  fs/smb/client/connect.c | 20 ++++++++++++--------
>  1 file changed, 12 insertions(+), 8 deletions(-)
>
> diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
> index 44bfdd88a906..8b7cffba1ad5 100644
> --- a/fs/smb/client/connect.c
> +++ b/fs/smb/client/connect.c
> @@ -216,17 +216,21 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
>         /* If server is a channel, select the primary channel */
>         pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
>
> +       /*
> +        * if the server has been marked for termination, there is a
> +        * chance that the remaining channels all need reconnect. To be
> +        * on the safer side, mark the session and trees for reconnect
> +        * for this scenario. This might cause a few redundant session
> +        * setup and tree connect requests, but it is better than not doing
> +        * a tree connect when needed, and all following requests failing
> +        */
> +       if (server->terminate) {
> +               mark_smb_session = true;
> +               server = pserver;
> +       }
>
>         spin_lock(&cifs_tcp_ses_lock);
>         list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
> -               /*
> -                * if channel has been marked for termination, nothing to do
> -                * for the channel. in fact, we cannot find the channel for the
> -                * server. So safe to exit here
> -                */
> -               if (server->terminate)
> -                       break;
> -
>                 /* check if iface is still active */
>                 if (!cifs_chan_is_iface_active(ses, server))
>                         cifs_chan_update_iface(ses, server);
> --
> 2.34.1
>

Sorry I missed sending out this patch before the other four.
This one needs to be applied first. Then the other four.
diff mbox series

Patch

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 44bfdd88a906..8b7cffba1ad5 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -216,17 +216,21 @@  cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 	/* If server is a channel, select the primary channel */
 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
 
+	/*
+	 * if the server has been marked for termination, there is a
+	 * chance that the remaining channels all need reconnect. To be
+	 * on the safer side, mark the session and trees for reconnect
+	 * for this scenario. This might cause a few redundant session
+	 * setup and tree connect requests, but it is better than not doing
+	 * a tree connect when needed, and all following requests failing
+	 */
+	if (server->terminate) {
+		mark_smb_session = true;
+		server = pserver;
+	}
 
 	spin_lock(&cifs_tcp_ses_lock);
 	list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
-		/*
-		 * if channel has been marked for termination, nothing to do
-		 * for the channel. in fact, we cannot find the channel for the
-		 * server. So safe to exit here
-		 */
-		if (server->terminate)
-			break;
-
 		/* check if iface is still active */
 		if (!cifs_chan_is_iface_active(ses, server))
 			cifs_chan_update_iface(ses, server);