Re: [PATCH 11/14] cifs: handle when server starts supporting multichannel

Steve French
2023-11-01T03:30:24Z

merged into cifs-2.6.git for-next pending more testing

added cc:stable

On Mon, Oct 30, 2023 at 6:00 AM <nspmangalore@gmail.com> wrote:
>
> From: Shyam Prasad N <sprasad@microsoft.com>
>
> When the user mounts with multichannel option, but the
> server does not support it, there can be a time in future
> where it can be supported.
>
> With this change, such a case is handled.
>
> Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
> ---
> fs/smb/client/cifsproto.h | 4 ++++
> fs/smb/client/connect.c | 6 +++++-
> fs/smb/client/smb2pdu.c | 31 ++++++++++++++++++++++++++++---
> 3 files changed, 37 insertions(+), 4 deletions(-)
>
> diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h
> index 65c84b3d1a65..5a4c1f1e0d91 100644
> --- a/fs/smb/client/cifsproto.h
> +++ b/fs/smb/client/cifsproto.h
> @@ -132,6 +132,10 @@ extern int SendReceiveBlockingLock(const unsigned int xid,
> struct smb_hdr *in_buf,
> struct smb_hdr *out_buf,
> int *bytes_returned);
> +
> +void
> +smb2_query_server_interfaces(struct work_struct *work);
> +
> void
> cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
> bool all_channels);
> diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
> index e71aa33bf026..149cde77500e 100644
> --- a/fs/smb/client/connect.c
> +++ b/fs/smb/client/connect.c
> @@ -116,7 +116,8 @@ static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
> return rc;
> }
>
> -static void smb2_query_server_interfaces(struct work_struct *work)
> +void
> +smb2_query_server_interfaces(struct work_struct *work)
> {
> int rc;
> int xid;
> @@ -134,6 +135,9 @@ static void smb2_query_server_interfaces(struct work_struct *work)
> if (rc) {
> cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
> __func__, rc);
> +
> + if (rc == -EOPNOTSUPP)
> + return;
> }
>
> queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
> diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
> index b7665155f4e2..2617437a4627 100644
> --- a/fs/smb/client/smb2pdu.c
> +++ b/fs/smb/client/smb2pdu.c
> @@ -163,6 +163,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
> int rc = 0;
> struct nls_table *nls_codepage = NULL;
> struct cifs_ses *ses;
> + int xid;
>
> /*
> * SMB2s NegProt, SessSetup, Logoff do not have tcon yet so
> @@ -307,17 +308,41 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
> tcon->need_reopen_files = true;
>
> rc = cifs_tree_connect(0, tcon, nls_codepage);
> - mutex_unlock(&ses->session_mutex);
>
> cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
> if (rc) {
> /* If sess reconnected but tcon didn't, something strange ... */
> + mutex_unlock(&ses->session_mutex);
> cifs_dbg(VFS, "reconnect tcon failed rc = %d\n", rc);
> goto out;
> }
>
> - if (smb2_command != SMB2_INTERNAL_CMD)
> - mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
> + if (!rc &&
> + (server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
> + mutex_unlock(&ses->session_mutex);
> +
> + /*
> + * query server network interfaces, in case they change
> + */
> + xid = get_xid();
> + rc = SMB3_request_interfaces(xid, tcon, false);
> + free_xid(xid);
> +
> + if (rc)
> + cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
> + __func__, rc);
> +
> + if (ses->chan_max > ses->chan_count &&
> + !SERVER_IS_CHAN(server)) {
> + if (ses->chan_count == 1)
> + cifs_dbg(VFS, "server %s supports multichannel now\n",
> + ses->server->hostname);
> +
> + cifs_try_adding_channels(tcon->cifs_sb, ses);
> + }
> + } else {
> + mutex_unlock(&ses->session_mutex);
> + }
>
> atomic_inc(&tconInfoReconnectCount);
> out:
> --
> 2.34.1
>

--
Thanks,

Steve