Re: [PATCH] cifs: Make echo interval tunable.

[Sachin Prabhu <sprabhu-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Mon, 2015-12-14 at 21:58 -0600, Shirish Pargaonkar wrote:
> Looks correct. Only comment would be to keep one definition of
> echo_interval,
> preferably unsigned int (instead of unsigned long also).

Sirish,

The event_timeout defined in struct smb_vol contains the timeout value
in seconds while the one defined in struct TCP_Server_Info multiplies
the value from the smb_vol by HZ to get the time in ticks.

Sachin Prabhu

> 
> On Mon, Dec 14, 2015 at 6:54 AM, Sachin Prabhu <sprabhu-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> wrote:
> > Another approach as pointed to by Jeff Layton is to make it a
> > module
> > parameter which is then set for all shares mounted on the client.
> > 
> > Any comments on the patch are welcome.
> > 
> > Sachin Prabhu
> > 
> > On Mon, 2015-12-14 at 18:17 +0530, Sachin Prabhu wrote:
> > > Currently the echo interval is set to 60 seconds using a macro.
> > > This
> > > setting determines the interval at which echo requests are sent
> > > to
> > > the
> > > server on an idling connection. This setting also affects the
> > > time
> > > required for a connection to an unresponsive server to timeout.
> > > 
> > > Making this setting a tunable allows users to control the echo
> > > interval
> > > times as well as control the time after which the connecting to
> > > an
> > > unresponsive server times out.
> > > 
> > > Signed-off-by: Sachin Prabhu <sprabhu-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> > > ---
> > >  fs/cifs/cifsfs.c   |  2 ++
> > >  fs/cifs/cifsglob.h |  8 ++++++--
> > >  fs/cifs/connect.c  | 33 +++++++++++++++++++++++++++------
> > >  3 files changed, 35 insertions(+), 8 deletions(-)
> > > 
> > > diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> > > index cbc0f4b..eab2de6 100644
> > > --- a/fs/cifs/cifsfs.c
> > > +++ b/fs/cifs/cifsfs.c
> > > @@ -507,6 +507,8 @@ cifs_show_options(struct seq_file *s, struct
> > > dentry *root)
> > > 
> > >       seq_printf(s, ",rsize=%u", cifs_sb->rsize);
> > >       seq_printf(s, ",wsize=%u", cifs_sb->wsize);
> > > +     seq_printf(s, ",echo_interval=%lu",
> > > +                     tcon->ses->server->echo_interval / HZ);
> > >       /* convert actimeo and display it in seconds */
> > >       seq_printf(s, ",actimeo=%lu", cifs_sb->actimeo / HZ);
> > > 
> > > diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> > > index 2b510c5..56d3698 100644
> > > --- a/fs/cifs/cifsglob.h
> > > +++ b/fs/cifs/cifsglob.h
> > > @@ -70,8 +70,10 @@
> > >  #define SERVER_NAME_LENGTH 40
> > >  #define SERVER_NAME_LEN_WITH_NULL     (SERVER_NAME_LENGTH + 1)
> > > 
> > > -/* SMB echo "timeout" -- FIXME: tunable? */
> > > -#define SMB_ECHO_INTERVAL (60 * HZ)
> > > +/* echo interval in seconds */
> > > +#define SMB_ECHO_INTERVAL_MIN 10
> > > +#define SMB_ECHO_INTERVAL_MAX 120
> > > +#define SMB_ECHO_INTERVAL_DEFAULT 60
> > > 
> > >  #include "cifspdu.h"
> > > 
> > > @@ -507,6 +509,7 @@ struct smb_vol {
> > >       struct sockaddr_storage dstaddr; /* destination address */
> > >       struct sockaddr_storage srcaddr; /* allow binding to a
> > > local
> > > IP */
> > >       struct nls_table *local_nls;
> > > +     unsigned int echo_interval; /* echo interval in secs */
> > >  };
> > > 
> > >  #define CIFS_MOUNT_MASK (CIFS_MOUNT_NO_PERM | CIFS_MOUNT_SET_UID
> > > | \
> > > @@ -628,6 +631,7 @@ struct TCP_Server_Info {
> > >       unsigned int    max_read;
> > >       unsigned int    max_write;
> > >  #endif /* CONFIG_CIFS_SMB2 */
> > > +     unsigned long echo_interval;
> > >  };
> > > 
> > >  static inline unsigned int
> > > diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> > > index ecb0803..3b44e9e 100644
> > > --- a/fs/cifs/connect.c
> > > +++ b/fs/cifs/connect.c
> > > @@ -95,6 +95,7 @@ enum {
> > >       Opt_cruid, Opt_gid, Opt_file_mode,
> > >       Opt_dirmode, Opt_port,
> > >       Opt_rsize, Opt_wsize, Opt_actimeo,
> > > +     Opt_echo_interval,
> > > 
> > >       /* Mount options which take string value */
> > >       Opt_user, Opt_pass, Opt_ip,
> > > @@ -188,6 +189,7 @@ static const match_table_t
> > > cifs_mount_option_tokens = {
> > >       { Opt_rsize, "rsize=%s" },
> > >       { Opt_wsize, "wsize=%s" },
> > >       { Opt_actimeo, "actimeo=%s" },
> > > +     { Opt_echo_interval, "echo_interval=%s" },
> > > 
> > >       { Opt_blank_user, "user=" },
> > >       { Opt_blank_user, "username=" },
> > > @@ -418,6 +420,7 @@ cifs_echo_request(struct work_struct *work)
> > >       int rc;
> > >       struct TCP_Server_Info *server = container_of(work,
> > >                                       struct TCP_Server_Info,
> > > echo.work);
> > > +     unsigned long echo_interval = server->echo_interval;
> > > 
> > >       /*
> > >        * We cannot send an echo if it is disabled or until the
> > > @@ -427,7 +430,7 @@ cifs_echo_request(struct work_struct *work)
> > >        */
> > >       if (!server->ops->need_neg || server->ops->need_neg(server)
> > > > > 
> > >           (server->ops->can_echo && !server->ops
> > > ->can_echo(server)) ||
> > > -         time_before(jiffies, server->lstrp + SMB_ECHO_INTERVAL
> > > -
> > > HZ))
> > > +         time_before(jiffies, server->lstrp + echo_interval -
> > > HZ))
> > >               goto requeue_echo;
> > > 
> > >       rc = server->ops->echo ? server->ops->echo(server) :
> > > -ENOSYS;
> > > @@ -436,7 +439,7 @@ cifs_echo_request(struct work_struct *work)
> > >                        server->hostname);
> > > 
> > >  requeue_echo:
> > > -     queue_delayed_work(cifsiod_wq, &server->echo,
> > > SMB_ECHO_INTERVAL);
> > > +     queue_delayed_work(cifsiod_wq, &server->echo,
> > > echo_interval);
> > >  }
> > > 
> > >  static bool
> > > @@ -487,9 +490,9 @@ server_unresponsive(struct TCP_Server_Info
> > > *server)
> > >        *     a response in >60s.
> > >        */
> > >       if (server->tcpStatus == CifsGood &&
> > > -         time_after(jiffies, server->lstrp + 2 *
> > > SMB_ECHO_INTERVAL)) {
> > > -             cifs_dbg(VFS, "Server %s has not responded in %d
> > > seconds. Reconnecting...\n",
> > > -                      server->hostname, (2 * SMB_ECHO_INTERVAL)
> > > /
> > > HZ);
> > > +         time_after(jiffies, server->lstrp + 2 * server
> > > ->echo_interval)) {
> > > +             cifs_dbg(VFS, "Server %s has not responded in %lu
> > > seconds. Reconnecting...\n",
> > > +                      server->hostname, (2 * server
> > > ->echo_interval) / HZ);
> > >               cifs_reconnect(server);
> > >               wake_up(&server->response_q);
> > >               return true;
> > > @@ -1624,6 +1627,14 @@ cifs_parse_mount_options(const char
> > > *mountdata, const char *devname,
> > >                               goto cifs_parse_mount_err;
> > >                       }
> > >                       break;
> > > +             case Opt_echo_interval:
> > > +                     if (get_option_ul(args, &option)) {
> > > +                             cifs_dbg(VFS, "%s: Invalid echo
> > > interval value\n",
> > > +                                      __func__);
> > > +                             goto cifs_parse_mount_err;
> > > +                     }
> > > +                     vol->echo_interval = option;
> > > +                     break;
> > > 
> > >               /* String Arguments */
> > > 
> > > @@ -2089,6 +2100,9 @@ static int match_server(struct
> > > TCP_Server_Info
> > > *server, struct smb_vol *vol)
> > >       if (!match_security(server, vol))
> > >               return 0;
> > > 
> > > +     if (server->echo_interval != vol->echo_interval)
> > > +             return 0;
> > > +
> > >       return 1;
> > >  }
> > > 
> > > @@ -2208,6 +2222,13 @@ cifs_get_tcp_session(struct smb_vol
> > > *volume_info)
> > >       tcp_ses->tcpStatus = CifsNew;
> > >       ++tcp_ses->srv_count;
> > > 
> > > +     /* echo interval should be between 10 and 120 secs */
> > > +     if (volume_info->echo_interval > SMB_ECHO_INTERVAL_MIN ||
> > > +             volume_info->echo_interval < SMB_ECHO_INTERVAL_MAX)
> > > +             tcp_ses->echo_interval = volume_info->echo_interval
> > > * HZ;
> > > +     else
> > > +             tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT
> > > *
> > > HZ;
> > > +
> > >       rc = ip_connect(tcp_ses);
> > >       if (rc < 0) {
> > >               cifs_dbg(VFS, "Error connecting to socket. Aborting
> > > operation.\n");
> > > @@ -2237,7 +2258,7 @@ cifs_get_tcp_session(struct smb_vol
> > > *volume_info)
> > >       cifs_fscache_get_client_cookie(tcp_ses);
> > > 
> > >       /* queue echo request delayed work */
> > > -     queue_delayed_work(cifsiod_wq, &tcp_ses->echo,
> > > SMB_ECHO_INTERVAL);
> > > +     queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses
> > > ->echo_interval);
> > > 
> > >       return tcp_ses;
> > > 
> > 
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