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

From: Long Li
Date: Tue Aug 29 2017 - 18:57:03 EST



> -----Original Message-----
> From: Pavel Shilovsky [mailto:piastryyy@xxxxxxxxx]
> Sent: Tuesday, August 29, 2017 3:37 PM
> To: Long Li <longli@xxxxxxxxxxxxx>
> Cc: Steve French <sfrench@xxxxxxxxx>; linux-cifs <linux-
> cifs@xxxxxxxxxxxxxxx>; samba-technical <samba-technical@xxxxxxxxxxxxxxx>;
> Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>; linux-
> rdma@xxxxxxxxxxxxxxx; Christoph Hellwig <hch@xxxxxxxxxxxxx>; Tom Talpey
> <ttalpey@xxxxxxxxxxxxx>; Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>;
> Long Li <longli@xxxxxxxxxxxxx>
> Subject: Re: [Patch v3 01/19] CIFS: Add rdma mount option
>
> 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.

I can move this patch to later.

However it doesnât break the build, just does nothing at all.

>
> --
> Best regards,
> Pavel Shilovsky