Re: [Patch v3 01/19] CIFS: Add rdma mount option

[Pavel Shilovsky]

2017-08-29 12:28 GMT-07:00 Long Li <longli@xxxxxxxxxxxxxxxxxxxxxx>:
> From: Long Li <longli@xxxxxxxxxxxxx>
>
> Add "rdma" to CIFS mount options to connect to SMB Direct.
> Add checks to validate this is used on SMB 3.X dialects.
>
> To connect to SMBDirect, use "mount.cifs -o rdma,vers=3.x".
> At the time of this patch, 3.x can be 3.0, 3.02 or 3.1.1.
>
> Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
> ---
>  fs/cifs/cifs_debug.c |  2 ++
>  fs/cifs/cifsfs.c     |  2 ++
>  fs/cifs/cifsglob.h   |  3 +++
>  fs/cifs/connect.c    | 15 ++++++++++++++-
>  4 files changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
> index 9727e1d..ba0870d 100644
> --- a/fs/cifs/cifs_debug.c
> +++ b/fs/cifs/cifs_debug.c
> @@ -171,6 +171,8 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
>                                 ses->ses_count, ses->serverOS, ses->serverNOS,
>                                 ses->capabilities, ses->status);
>                         }
> +                       if (server->rdma)
> +                               seq_printf(m, "RDMA\n\t");
>                         seq_printf(m, "TCP status: %d\n\tLocal Users To "
>                                    "Server: %d SecMode: 0x%x Req On Wire: %d",
>                                    server->tcpStatus, server->srv_count,
> diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> index fe0c8dc..a628800 100644
> --- a/fs/cifs/cifsfs.c
> +++ b/fs/cifs/cifsfs.c
> @@ -330,6 +330,8 @@ cifs_show_address(struct seq_file *s, struct TCP_Server_Info *server)
>         default:
>                 seq_puts(s, "(unknown)");
>         }
> +       if (server->rdma)
> +               seq_puts(s, ",rdma");
>  }
>
>  static void
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index 8289f95..703c2fb 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -531,6 +531,7 @@ struct smb_vol {
>         bool nopersistent:1;
>         bool resilient:1; /* noresilient not required since not fored for CA */
>         bool domainauto:1;
> +       bool rdma:1;
>         unsigned int rsize;
>         unsigned int wsize;
>         bool sockopt_tcp_nodelay:1;
> @@ -649,6 +650,8 @@ struct TCP_Server_Info {
>         bool    sec_kerberos;           /* supports plain Kerberos */
>         bool    sec_mskerberos;         /* supports legacy MS Kerberos */
>         bool    large_buf;              /* is current buffer large? */
> +       /* use SMBD connection instead of socket */
> +       bool    rdma;
>         struct delayed_work     echo; /* echo ping workqueue job */
>         char    *smallbuf;      /* pointer to current "small" buffer */
>         char    *bigbuf;        /* pointer to current "big" buffer */
> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> index 2eeaac6..19fdca8 100644
> --- a/fs/cifs/connect.c
> +++ b/fs/cifs/connect.c
> @@ -94,7 +94,7 @@ enum {
>         Opt_multiuser, Opt_sloppy, Opt_nosharesock,
>         Opt_persistent, Opt_nopersistent,
>         Opt_resilient, Opt_noresilient,
> -       Opt_domainauto,
> +       Opt_domainauto, Opt_rdma,
>
>         /* Mount options which take numeric value */
>         Opt_backupuid, Opt_backupgid, Opt_uid,
> @@ -185,6 +185,7 @@ static const match_table_t cifs_mount_option_tokens = {
>         { Opt_resilient, "resilienthandles"},
>         { Opt_noresilient, "noresilienthandles"},
>         { Opt_domainauto, "domainauto"},
> +       { Opt_rdma, "rdma"},
>
>         { Opt_backupuid, "backupuid=%s" },
>         { Opt_backupgid, "backupgid=%s" },
> @@ -1541,6 +1542,9 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
>                 case Opt_domainauto:
>                         vol->domainauto = true;
>                         break;
> +               case Opt_rdma:
> +                       vol->rdma = true;
> +                       break;
>
>                 /* Numeric Values */
>                 case Opt_backupuid:
> @@ -1931,6 +1935,11 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
>                 goto cifs_parse_mount_err;
>         }
>
> +       if (vol->rdma && vol->vals->protocol_id < SMB30_PROT_ID) {
> +               cifs_dbg(VFS, "SMB Direct requires Version >=3.0\n");
> +               goto cifs_parse_mount_err;
> +       }
> +
>  #ifndef CONFIG_KEYS
>         /* Muliuser mounts require CONFIG_KEYS support */
>         if (vol->multiuser) {
> @@ -2134,6 +2143,9 @@ static int match_server(struct TCP_Server_Info *server, struct smb_vol *vol)
>         if (server->echo_interval != vol->echo_interval * HZ)
>                 return 0;
>
> +       if (server->rdma != vol->rdma)
> +               return 0;
> +
>         return 1;
>  }
>
> @@ -2234,6 +2246,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
>         tcp_ses->noblocksnd = volume_info->noblocksnd;
>         tcp_ses->noautotune = volume_info->noautotune;
>         tcp_ses->tcp_nodelay = volume_info->sockopt_tcp_nodelay;
> +       tcp_ses->rdma = volume_info->rdma;
>         tcp_ses->in_flight = 0;
>         tcp_ses->credits = 1;
>         init_waitqueue_head(&tcp_ses->response_q);
> --
> 2.7.4
>
> --
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It is better to introduce a mount option after the functional changes
not before them. In this case we do not result in having the mount
option that does nothing if we break the patchset.

--
Best regards,
Pavel Shilovsky