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

[Paulo Alcantara <pc@manguebit.com>]

nspmangalore@gmail.com writes:

> 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);
> +

Why are you exporting this?  smb2_query_server_interfaces() seems to be
used only in fs/smb/client/connect.c.

>  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)
>  {

Ditto.

>  	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;

Maybe also get rid of cifs_dbg() when rc == -EOPNOTSUPP?

>  	}
>  
>  	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);

Why are you removing this optimisation?  For example, session/tcon
reconnect will no longer be triggered after returning back to userspace,
only when next I/O comes in.