[Patch v2 01/19] CIFS: Add RDMA mount option

Long Li
2017-08-20T19:04:25Z

From: Long Li <longli-0li6OtcxBFHby3iVrkZq2A@public.gmane.org>

Add "rdma" to CIFS mount option, which tells CIFS this is for connecting to a SMB server over SMBDirect. Add checks to validate this feature is only used on SMB 3.X dialects.

To connect to SMBDirect, use "mount.cifs -o rdma,vers=3.x".

Signed-off-by: Long Li <longli-0li6OtcxBFHby3iVrkZq2A@public.gmane.org>
---
fs/cifs/cifs_debug.c | 2 ++
fs/cifs/cifsfs.c | 2 ++
fs/cifs/cifsglob.h | 3 +++
fs/cifs/connect.c | 25 ++++++++++++++++++++++++-
4 files changed, 31 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..d5d0ecd 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 +1935,21 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
goto cifs_parse_mount_err;
}

+ if (vol->rdma) {
+ switch (vol->vals->protocol_id) {
+ case SMB30_PROT_ID:
+ case SMB302_PROT_ID:
+ case SMB311_PROT_ID:
+ break;
+ default:
+ cifs_dbg(
+ VFS,
+ "SMBDirect requires Version "
+ "3.0, 3.02 or 3.1.1\n");
+ goto cifs_parse_mount_err;
+ }
+ }
+
#ifndef CONFIG_KEYS
/* Muliuser mounts require CONFIG_KEYS support */
if (vol->multiuser) {
@@ -2134,6 +2153,9 @@ 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 +2256,7 @@ 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