2017-11-23 00:45:45

by Long Li

[permalink] [raw]
Subject: [Patch v8 00/16] CIFS: Implement SMB Direct protocol

From: Long Li <[email protected]>

Starting with SMB2 dialect 3.0, Microsoft introduced SMB Direct transport
protocol for transferring upper layer (SMB2) payload over RDMA via Infiniband,
RoCE or iWARP. The prococol is published in [MS-SMBD]
(https://msdn.microsoft.com/en-us/library/hh536346.aspx).

Change log:
v2:
Implemented RDMA read/write via memory registration.
Re-arranged patches for review [Christoph Hellwig <[email protected]>].
Restructured the code and fixed bugs on protocol timer and keepalive
[Tom Talpey <[email protected]>].

v3:
Improved performance by introducing an additional queue for handling
empty packets and reducing lock contention on IRQ path.
Added light weight profiling by reading TSC.
Improved the code for checking SMB versions when mounting with rdma option
[Leon Romanovsky <[email protected]>].
Moved to use pages instead of buffers for passing I/O for RDMA
[Christoph Hellwig <[email protected]>].
Removed redundant code and refactored I/O code paths
[Christoph Hellwig <[email protected]>, Tom Talpey <[email protected]>].

v4:
Fixed connectivity issues with iWAPR devices.
Exported configurable protocol parameters to /proc/fs/cifs
[Steve French <[email protected]>]
Re-arranged patches for review
[Pavel Shilovsky <[email protected]>].

v5:
Fixed compiling errors on ia64, i386 and when INFINIBAND is not
configured. [kbuild test robot]
Profiling is removed and will be introduced in a seperate patch.

v6:
Report internal code error via WARN_ON(). Change description in
Kconfig [Pavel Shilovsky <[email protected]>].

v7:
Removed the use of #ifdef CONFIG_CIFS_SMB_DIRECT in upper layer
code calling transport I/O. [Matthew Wilcox <[email protected]>,
Tom Talpey <[email protected]>]

v8:
Fixed comment typos and removed unused code
[Ronnie Sahlberg <[email protected]>]
Removed the first 7 patches in v7, which have been merged.
Restructed the code to move relevant function definitions to later patches.
[Pavel Shilovsky <[email protected]>]
Added a patch to disable signing when RDMA is in use. Signing will be
enabled after it is properly implemented in SMB Direct code paths.
Fixed an issue on passing the incorrect offset to smbd_buffer_descriptor_v1
when RDMA read is used for SMB write. This was caused by recent CIFS
patches to remove packet length from SMB2 packet header.

Long Li (16):
CIFS: SMBD: Upper layer connects to SMBDirect session
CIFS: SMBD: Implement function to reconnect to a SMB Direct transport
CIFS: SMBD: Upper layer reconnects to SMB Direct session
CIFS: SMBD: Implement function to destroy a SMB Direct connection
CIFS: SMBD: Upper layer destroys SMB Direct session on shutdown or
umount
CIFS: SMBD: Set SMB Direct maximum read or write size for I/O
CIFS: SMBD: Implement function to receive data via RDMA receive
CIFS: SMBD: Upper layer receives data via RDMA receive
CIFS: SMBD: Implement function to send data via RDMA send
CIFS: SMBD: Upper layer sends data via RDMA send
CIFS: SMBD: Implement RDMA memory registration
CIFS: SMBD: Upper layer performs SMB write via RDMA read through
memory registration
CIFS: SMBD: Read correct returned data length for RDMA write (SMB
read) I/O
CIFS: SMBD: Upper layer performs SMB read via RDMA write through
memory registration
CIFS: SMBD: Add SMB Direct debug counters
CIFS: SMBD: Disable signing on SMB direct transport

fs/cifs/cifs_debug.c | 66 ++++
fs/cifs/cifsglob.h | 16 +-
fs/cifs/cifssmb.c | 15 +-
fs/cifs/connect.c | 46 ++-
fs/cifs/file.c | 17 +-
fs/cifs/smb1ops.c | 4 +-
fs/cifs/smb2ops.c | 24 +-
fs/cifs/smb2pdu.c | 117 ++++++-
fs/cifs/smbdirect.c | 947 +++++++++++++++++++++++++++++++++++++++++++++++++++
fs/cifs/smbdirect.h | 72 ++++
fs/cifs/transport.c | 8 +-
11 files changed, 1308 insertions(+), 24 deletions(-)

--
2.7.4


From 1584820411039302614@xxx Thu Nov 23 02:02:02 +0000 2017
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2017-11-23 00:44:25

by Long Li

[permalink] [raw]
Subject: [Patch v8 15/16] CIFS: SMBD: Add SMB Direct debug counters

From: Long Li <[email protected]>

For debugging and troubleshooting, export SMBDirect debug counters to
/proc/fs/cifs/DebugData.

Signed-off-by: Long Li <[email protected]>
---
fs/cifs/cifs_debug.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 66 insertions(+)

diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index e6045fd..05be9b4 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -155,6 +155,72 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
list_for_each(tmp1, &cifs_tcp_ses_list) {
server = list_entry(tmp1, struct TCP_Server_Info,
tcp_ses_list);
+
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ if (!server->rdma)
+ goto skip_rdma;
+
+ seq_printf(m, "\nSMBDirect (in hex) protocol version: %x "
+ "transport status: %x",
+ server->smbd_conn->protocol,
+ server->smbd_conn->transport_status);
+ seq_printf(m, "\nConn receive_credit_max: %x "
+ "send_credit_target: %x max_send_size: %x",
+ server->smbd_conn->receive_credit_max,
+ server->smbd_conn->send_credit_target,
+ server->smbd_conn->max_send_size);
+ seq_printf(m, "\nConn max_fragmented_recv_size: %x "
+ "max_fragmented_send_size: %x max_receive_size:%x",
+ server->smbd_conn->max_fragmented_recv_size,
+ server->smbd_conn->max_fragmented_send_size,
+ server->smbd_conn->max_receive_size);
+ seq_printf(m, "\nConn keep_alive_interval: %x "
+ "max_readwrite_size: %x rdma_readwrite_threshold: %x",
+ server->smbd_conn->keep_alive_interval,
+ server->smbd_conn->max_readwrite_size,
+ server->smbd_conn->rdma_readwrite_threshold);
+ seq_printf(m, "\nDebug count_get_receive_buffer: %x "
+ "count_put_receive_buffer: %x count_send_empty: %x",
+ server->smbd_conn->count_get_receive_buffer,
+ server->smbd_conn->count_put_receive_buffer,
+ server->smbd_conn->count_send_empty);
+ seq_printf(m, "\nRead Queue count_reassembly_queue: %x "
+ "count_enqueue_reassembly_queue: %x "
+ "count_dequeue_reassembly_queue: %x "
+ "fragment_reassembly_remaining: %x "
+ "reassembly_data_length: %x "
+ "reassembly_queue_length: %x",
+ server->smbd_conn->count_reassembly_queue,
+ server->smbd_conn->count_enqueue_reassembly_queue,
+ server->smbd_conn->count_dequeue_reassembly_queue,
+ server->smbd_conn->fragment_reassembly_remaining,
+ server->smbd_conn->reassembly_data_length,
+ server->smbd_conn->reassembly_queue_length);
+ seq_printf(m, "\nCurrent Credits send_credits: %x "
+ "receive_credits: %x receive_credit_target: %x",
+ atomic_read(&server->smbd_conn->send_credits),
+ atomic_read(&server->smbd_conn->receive_credits),
+ server->smbd_conn->receive_credit_target);
+ seq_printf(m, "\nPending send_pending: %x send_payload_pending:"
+ " %x smbd_send_pending: %x smbd_recv_pending: %x",
+ atomic_read(&server->smbd_conn->send_pending),
+ atomic_read(&server->smbd_conn->send_payload_pending),
+ server->smbd_conn->smbd_send_pending,
+ server->smbd_conn->smbd_recv_pending);
+ seq_printf(m, "\nReceive buffers count_receive_queue: %x "
+ "count_empty_packet_queue: %x",
+ server->smbd_conn->count_receive_queue,
+ server->smbd_conn->count_empty_packet_queue);
+ seq_printf(m, "\nMR responder_resources: %x "
+ "max_frmr_depth: %x mr_type: %x",
+ server->smbd_conn->responder_resources,
+ server->smbd_conn->max_frmr_depth,
+ server->smbd_conn->mr_type);
+ seq_printf(m, "\nMR mr_ready_count: %x mr_used_count: %x",
+ atomic_read(&server->smbd_conn->mr_ready_count),
+ atomic_read(&server->smbd_conn->mr_used_count));
+skip_rdma:
+#endif
seq_printf(m, "\nNumber of credits: %d", server->credits);
i++;
list_for_each(tmp2, &server->smb_ses_list) {
--
2.7.4


From 1584851443482187715@xxx Thu Nov 23 10:15:16 +0000 2017
X-GM-THRID: 1584783660551394622
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2017-11-23 00:41:46

by Long Li

[permalink] [raw]
Subject: [Patch v8 03/16] CIFS: SMBD: Upper layer reconnects to SMB Direct session

From: Long Li <[email protected]>

Do a reconnect on SMB Direct when it is used as the connection. Reconnect can
happen for many reasons and it's mostly the decision of SMB2 upper layer.

Signed-off-by: Long Li <[email protected]>
---
fs/cifs/connect.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index fafaecb..fc46066 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -406,7 +406,10 @@ cifs_reconnect(struct TCP_Server_Info *server)

/* we should try only the port we connected to before */
mutex_lock(&server->srv_mutex);
- rc = generic_ip_connect(server);
+ if (cifs_rdma_enabled(server))
+ rc = smbd_reconnect(server);
+ else
+ rc = generic_ip_connect(server);
if (rc) {
cifs_dbg(FYI, "reconnect error %d\n", rc);
mutex_unlock(&server->srv_mutex);
--
2.7.4


From 1584827884630898061@xxx Thu Nov 23 04:00:49 +0000 2017
X-GM-THRID: 1584667180237862520
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread

2017-11-23 00:44:59

by Long Li

[permalink] [raw]
Subject: [Patch v8 14/16] CIFS: SMBD: Upper layer performs SMB read via RDMA write through memory registration

From: Long Li <[email protected]>

If I/O size is larger than rdma_readwrite_threshold, use RDMA write for
SMB read by specifying channel SMB2_CHANNEL_RDMA_V1 or
SMB2_CHANNEL_RDMA_V1_INVALIDATE in the SMB packet, depending on SMB dialect
used. Append a smbd_buffer_descriptor_v1 to the end of the SMB packet and fill
in other values to indicate this SMB read uses RDMA write.

There is no need to read from the transport for incoming payload. At the time
SMB read response comes back, the data is already transfered and placed in the
pages by RDMA hardware.

When SMB read is finished, deregister the memory regions if RDMA write is used
for this SMB read. smbd_deregister_mr may need to do local invalidation and
sleep, if server remote invalidation is not used.

There are situations where the MID may not be created on I/O failure, under
which memory region is deregistered when read data context is released.

Signed-off-by: Long Li <[email protected]>
---
fs/cifs/file.c | 17 +++++++++++++++--
fs/cifs/smb2pdu.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 59 insertions(+), 3 deletions(-)

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index df9f682..93259a16 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -42,7 +42,7 @@
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "fscache.h"
-
+#include "smbdirect.h"

static inline int cifs_convert_flags(unsigned int flags)
{
@@ -2902,7 +2902,12 @@ cifs_readdata_release(struct kref *refcount)
{
struct cifs_readdata *rdata = container_of(refcount,
struct cifs_readdata, refcount);
-
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ if (rdata->mr) {
+ smbd_deregister_mr(rdata->mr);
+ rdata->mr = NULL;
+ }
+#endif
if (rdata->cfile)
cifsFileInfo_put(rdata->cfile);

@@ -3031,6 +3036,10 @@ uncached_fill_pages(struct TCP_Server_Info *server,
}
if (iter)
result = copy_page_from_iter(page, 0, n, iter);
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ else if (rdata->mr)
+ result = n;
+#endif
else
result = cifs_read_page_from_socket(server, page, n);
if (result < 0)
@@ -3600,6 +3609,10 @@ readpages_fill_pages(struct TCP_Server_Info *server,

if (iter)
result = copy_page_from_iter(page, 0, n, iter);
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ else if (rdata->mr)
+ result = n;
+#endif
else
result = cifs_read_page_from_socket(server, page, n);
if (result < 0)
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 908d777..bee0871d 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2458,7 +2458,40 @@ smb2_new_read_req(void **buf, unsigned int *total_len,
req->MinimumCount = 0;
req->Length = cpu_to_le32(io_parms->length);
req->Offset = cpu_to_le64(io_parms->offset);
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ /*
+ * If we want to do a RDMA write, fill in and append
+ * smbd_buffer_descriptor_v1 to the end of read request
+ */
+ if (server->rdma && rdata &&
+ rdata->bytes >= server->smbd_conn->rdma_readwrite_threshold) {
+
+ struct smbd_buffer_descriptor_v1 *v1;
+ bool need_invalidate =
+ io_parms->tcon->ses->server->dialect == SMB30_PROT_ID;
+
+ rdata->mr = smbd_register_mr(
+ server->smbd_conn, rdata->pages,
+ rdata->nr_pages, rdata->tailsz,
+ true, need_invalidate);
+ if (!rdata->mr)
+ return -ENOBUFS;
+
+ req->Channel = SMB2_CHANNEL_RDMA_V1_INVALIDATE;
+ if (need_invalidate)
+ req->Channel = SMB2_CHANNEL_RDMA_V1;
+ req->ReadChannelInfoOffset =
+ offsetof(struct smb2_read_plain_req, Buffer);
+ req->ReadChannelInfoLength =
+ sizeof(struct smbd_buffer_descriptor_v1);
+ v1 = (struct smbd_buffer_descriptor_v1 *) &req->Buffer[0];
+ v1->offset = rdata->mr->mr->iova;
+ v1->token = rdata->mr->mr->rkey;
+ v1->length = rdata->mr->mr->length;

+ *total_len += sizeof(*v1) - 1;
+ }
+#endif
if (request_type & CHAINED_REQUEST) {
if (!(request_type & END_OF_CHAIN)) {
/* next 8-byte aligned request */
@@ -2537,7 +2570,17 @@ smb2_readv_callback(struct mid_q_entry *mid)
if (rdata->result != -ENODATA)
rdata->result = -EIO;
}
-
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ /*
+ * If this rdata has a memmory registered, the MR can be freed
+ * MR needs to be freed as soon as I/O finishes to prevent deadlock
+ * because they have limited number and are used for future I/Os
+ */
+ if (rdata->mr) {
+ smbd_deregister_mr(rdata->mr);
+ rdata->mr = NULL;
+ }
+#endif
if (rdata->result)
cifs_stats_fail_inc(tcon, SMB2_READ_HE);

--
2.7.4


From 1584808407086245032@xxx Wed Nov 22 22:51:14 +0000 2017
X-GM-THRID: 1584808407086245032
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread

2017-11-23 00:42:49

by Long Li

[permalink] [raw]
Subject: [Patch v8 09/16] CIFS: SMBD: Implement function to send data via RDMA send

From: Long Li <[email protected]>

The transport doesn't maintain send buffers or send queue for transferring
payload via RDMA send. There is no data copy in the transport on send.

Signed-off-by: Long Li <[email protected]>
---
fs/cifs/smbdirect.c | 246 ++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/cifs/smbdirect.h | 5 ++
2 files changed, 251 insertions(+)

diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index 6cff234..cb062e2 100644
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -41,6 +41,12 @@ static int smbd_post_recv(
struct smbd_response *response);

static int smbd_post_send_empty(struct smbd_connection *info);
+static int smbd_post_send_data(
+ struct smbd_connection *info,
+ struct kvec *iov, int n_vec, int remaining_data_length);
+static int smbd_post_send_page(struct smbd_connection *info,
+ struct page *page, unsigned long offset,
+ size_t size, int remaining_data_length);

/* SMBD version number */
#define SMBD_V1 0x0100
@@ -177,6 +183,10 @@ static void smbd_destroy_rdma_work(struct work_struct *work)
log_rdma_event(INFO, "cancelling send immediate work\n");
cancel_delayed_work_sync(&info->send_immediate_work);

+ log_rdma_event(INFO, "wait for all send to finish\n");
+ wait_event(info->wait_smbd_send_pending,
+ info->smbd_send_pending == 0);
+
log_rdma_event(INFO, "wait for all recv to finish\n");
wake_up_interruptible(&info->wait_reassembly_queue);
wait_event(info->wait_smbd_recv_pending,
@@ -1078,6 +1088,24 @@ static int smbd_post_send_sgl(struct smbd_connection *info,
}

/*
+ * Send a page
+ * page: the page to send
+ * offset: offset in the page to send
+ * size: length in the page to send
+ * remaining_data_length: remaining data to send in this payload
+ */
+static int smbd_post_send_page(struct smbd_connection *info, struct page *page,
+ unsigned long offset, size_t size, int remaining_data_length)
+{
+ struct scatterlist sgl;
+
+ sg_init_table(&sgl, 1);
+ sg_set_page(&sgl, page, size, offset);
+
+ return smbd_post_send_sgl(info, &sgl, size, remaining_data_length);
+}
+
+/*
* Send an empty message
* Empty message is used to extend credits to peer to for keep live
* while there is no upper layer payload to send at the time
@@ -1089,6 +1117,35 @@ static int smbd_post_send_empty(struct smbd_connection *info)
}

/*
+ * Send a data buffer
+ * iov: the iov array describing the data buffers
+ * n_vec: number of iov array
+ * remaining_data_length: remaining data to send following this packet
+ * in segmented SMBD packet
+ */
+static int smbd_post_send_data(
+ struct smbd_connection *info, struct kvec *iov, int n_vec,
+ int remaining_data_length)
+{
+ int i;
+ u32 data_length = 0;
+ struct scatterlist sgl[SMBDIRECT_MAX_SGE];
+
+ if (n_vec > SMBDIRECT_MAX_SGE) {
+ cifs_dbg(VFS, "Can't fit data to SGL, n_vec=%d\n", n_vec);
+ return -ENOMEM;
+ }
+
+ sg_init_table(sgl, n_vec);
+ for (i = 0; i < n_vec; i++) {
+ data_length += iov[i].iov_len;
+ sg_set_buf(&sgl[i], iov[i].iov_base, iov[i].iov_len);
+ }
+
+ return smbd_post_send_sgl(info, sgl, data_length, remaining_data_length);
+}
+
+/*
* Post a receive request to the transport
* The remote peer can only send data when a receive request is posted
* The interaction is controlled by send/receive credit system
@@ -1652,6 +1709,9 @@ struct smbd_connection *_smbd_get_connection(
queue_delayed_work(info->workqueue, &info->idle_timer_work,
info->keep_alive_interval*HZ);

+ init_waitqueue_head(&info->wait_smbd_send_pending);
+ info->smbd_send_pending = 0;
+
init_waitqueue_head(&info->wait_smbd_recv_pending);
info->smbd_recv_pending = 0;

@@ -1943,3 +2003,189 @@ int smbd_recv(struct smbd_connection *info, struct msghdr *msg)
msg->msg_iter.count = 0;
return rc;
}
+
+/*
+ * Send data to transport
+ * Each rqst is transported as a SMBDirect payload
+ * rqst: the data to write
+ * return value: 0 if successfully write, otherwise error code
+ */
+int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst)
+{
+ struct kvec vec;
+ int nvecs;
+ int size;
+ int buflen = 0, remaining_data_length;
+ int start, i, j;
+ int max_iov_size =
+ info->max_send_size - sizeof(struct smbd_data_transfer);
+ struct kvec iov[SMBDIRECT_MAX_SGE];
+ int rc;
+
+ info->smbd_send_pending++;
+ if (info->transport_status != SMBD_CONNECTED) {
+ rc = -ENODEV;
+ goto done;
+ }
+
+ /*
+ * This usually means a configuration error
+ * We use RDMA read/write for packet size > rdma_readwrite_threshold
+ * as long as it's properly configured we should never get into this
+ * situation
+ */
+ if (rqst->rq_nvec + rqst->rq_npages > SMBDIRECT_MAX_SGE) {
+ log_write(ERR, "maximum send segment %x exceeding %x\n",
+ rqst->rq_nvec + rqst->rq_npages, SMBDIRECT_MAX_SGE);
+ rc = -EINVAL;
+ goto done;
+ }
+
+ /*
+ * Remove the RFC1002 length defined in MS-SMB2 section 2.1
+ * It is used only for TCP transport
+ * In future we may want to add a transport layer under protocol
+ * layer so this will only be issued to TCP transport
+ */
+ iov[0].iov_base = (char *)rqst->rq_iov[0].iov_base + 4;
+ iov[0].iov_len = rqst->rq_iov[0].iov_len - 4;
+ buflen += iov[0].iov_len;
+
+ /* total up iov array first */
+ for (i = 1; i < rqst->rq_nvec; i++) {
+ iov[i].iov_base = rqst->rq_iov[i].iov_base;
+ iov[i].iov_len = rqst->rq_iov[i].iov_len;
+ buflen += iov[i].iov_len;
+ }
+
+ /* add in the page array if there is one */
+ if (rqst->rq_npages) {
+ buflen += rqst->rq_pagesz * (rqst->rq_npages - 1);
+ buflen += rqst->rq_tailsz;
+ }
+
+ if (buflen + sizeof(struct smbd_data_transfer) >
+ info->max_fragmented_send_size) {
+ log_write(ERR, "payload size %d > max size %d\n",
+ buflen, info->max_fragmented_send_size);
+ rc = -EINVAL;
+ goto done;
+ }
+
+ remaining_data_length = buflen;
+
+ log_write(INFO, "rqst->rq_nvec=%d rqst->rq_npages=%d rq_pagesz=%d "
+ "rq_tailsz=%d buflen=%d\n",
+ rqst->rq_nvec, rqst->rq_npages, rqst->rq_pagesz,
+ rqst->rq_tailsz, buflen);
+
+ start = i = iov[0].iov_len ? 0 : 1;
+ buflen = 0;
+ while (true) {
+ buflen += iov[i].iov_len;
+ if (buflen > max_iov_size) {
+ if (i > start) {
+ remaining_data_length -=
+ (buflen-iov[i].iov_len);
+ log_write(INFO, "sending iov[] from start=%d "
+ "i=%d nvecs=%d "
+ "remaining_data_length=%d\n",
+ start, i, i-start,
+ remaining_data_length);
+ rc = smbd_post_send_data(
+ info, &iov[start], i-start,
+ remaining_data_length);
+ if (rc)
+ goto done;
+ } else {
+ /* iov[start] is too big, break it */
+ nvecs = (buflen+max_iov_size-1)/max_iov_size;
+ log_write(INFO, "iov[%d] iov_base=%p buflen=%d"
+ " break to %d vectors\n",
+ start, iov[start].iov_base,
+ buflen, nvecs);
+ for (j = 0; j < nvecs; j++) {
+ vec.iov_base =
+ (char *)iov[start].iov_base +
+ j*max_iov_size;
+ vec.iov_len = max_iov_size;
+ if (j == nvecs-1)
+ vec.iov_len =
+ buflen -
+ max_iov_size*(nvecs-1);
+ remaining_data_length -= vec.iov_len;
+ log_write(INFO,
+ "sending vec j=%d iov_base=%p"
+ " iov_len=%zu "
+ "remaining_data_length=%d\n",
+ j, vec.iov_base, vec.iov_len,
+ remaining_data_length);
+ rc = smbd_post_send_data(
+ info, &vec, 1,
+ remaining_data_length);
+ if (rc)
+ goto done;
+ }
+ i++;
+ }
+ start = i;
+ buflen = 0;
+ } else {
+ i++;
+ if (i == rqst->rq_nvec) {
+ /* send out all remaining vecs */
+ remaining_data_length -= buflen;
+ log_write(INFO,
+ "sending iov[] from start=%d i=%d "
+ "nvecs=%d remaining_data_length=%d\n",
+ start, i, i-start,
+ remaining_data_length);
+ rc = smbd_post_send_data(info, &iov[start],
+ i-start, remaining_data_length);
+ if (rc)
+ goto done;
+ break;
+ }
+ }
+ log_write(INFO, "looping i=%d buflen=%d\n", i, buflen);
+ }
+
+ /* now sending pages if there are any */
+ for (i = 0; i < rqst->rq_npages; i++) {
+ buflen = (i == rqst->rq_npages-1) ?
+ rqst->rq_tailsz : rqst->rq_pagesz;
+ nvecs = (buflen + max_iov_size - 1) / max_iov_size;
+ log_write(INFO, "sending pages buflen=%d nvecs=%d\n",
+ buflen, nvecs);
+ for (j = 0; j < nvecs; j++) {
+ size = max_iov_size;
+ if (j == nvecs-1)
+ size = buflen - j*max_iov_size;
+ remaining_data_length -= size;
+ log_write(INFO, "sending pages i=%d offset=%d size=%d"
+ " remaining_data_length=%d\n",
+ i, j*max_iov_size, size, remaining_data_length);
+ rc = smbd_post_send_page(
+ info, rqst->rq_pages[i], j*max_iov_size,
+ size, remaining_data_length);
+ if (rc)
+ goto done;
+ }
+ }
+
+done:
+ /*
+ * As an optimization, we don't wait for individual I/O to finish
+ * before sending the next one.
+ * Send them all and wait for pending send count to get to 0
+ * that means all the I/Os have been out and we are good to return
+ */
+
+ wait_event(info->wait_send_payload_pending,
+ atomic_read(&info->send_payload_pending) == 0);
+
+ info->smbd_send_pending--;
+ wake_up(&info->wait_smbd_send_pending);
+
+ return rc;
+}
diff --git a/fs/cifs/smbdirect.h b/fs/cifs/smbdirect.h
index 990342e..d1cafa1 100644
--- a/fs/cifs/smbdirect.h
+++ b/fs/cifs/smbdirect.h
@@ -92,6 +92,9 @@ struct smbd_connection {

/* Activity accoutning */
/* Pending reqeusts issued from upper layer */
+ int smbd_send_pending;
+ wait_queue_head_t wait_smbd_send_pending;
+
int smbd_recv_pending;
wait_queue_head_t wait_smbd_recv_pending;

@@ -257,6 +260,7 @@ void smbd_destroy(struct smbd_connection *info);

/* Interface for carrying upper layer I/O through send/recv */
int smbd_recv(struct smbd_connection *info, struct msghdr *msg);
+int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst);

#else
#define cifs_rdma_enabled(server) 0
@@ -266,6 +270,7 @@ static inline void *smbd_get_connection(
static inline int smbd_reconnect(struct TCP_Server_Info *server) {return -1;}
static inline void smbd_destroy(struct smbd_connection *info) {}
static inline int smbd_recv(struct smbd_connection *info, struct msghdr *msg) {return -1;}
+static inline int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst) {return -1;}
#endif

#endif
--
2.7.4


From 1585539238975270695@xxx Fri Dec 01 00:27:29 +0000 2017
X-GM-THRID: 1585539238975270695
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread

2017-11-23 00:43:37

by Long Li

[permalink] [raw]
Subject: [Patch v8 08/16] CIFS: SMBD: Upper layer receives data via RDMA receive

From: Long Li <[email protected]>

With SMB Direct connected, use it for receiving data via RDMA receive.

Signed-off-by: Long Li <[email protected]>
---
fs/cifs/connect.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index d8bfa89..1677401 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -542,8 +542,10 @@ cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)

if (server_unresponsive(server))
return -ECONNABORTED;
-
- length = sock_recvmsg(server->ssocket, smb_msg, 0);
+ if (cifs_rdma_enabled(server) && server->smbd_conn)
+ length = smbd_recv(server->smbd_conn, smb_msg);
+ else
+ length = sock_recvmsg(server->ssocket, smb_msg, 0);

if (server->tcpStatus == CifsExiting)
return -ESHUTDOWN;
--
2.7.4


From 1584833916262089216@xxx Thu Nov 23 05:36:41 +0000 2017
X-GM-THRID: 1584833916262089216
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread

2017-11-23 00:43:20

by Long Li

[permalink] [raw]
Subject: [Patch v8 12/16] CIFS: SMBD: Upper layer performs SMB write via RDMA read through memory registration

From: Long Li <[email protected]>

When sending I/O, if size is larger than rdma_readwrite_threshold we prepare
to send SMB write packet for a RDMA read via memory registration. The actual
I/O is done by remote peer through local RDMA hardware. Modify the relevant
fields in the packet accordingly, and append a smbd_buffer_descriptor_v1 to
the end of the SMB write packet.

On write I/O finish, deregister the memory region if this was for a RDMA read.
If remote invalidation is not used, the call to smbd_deregister_mr will do
local invalidation and possibly wait. Memory region is normally deregistered
in MID callback as soon as it's used. There are situations where the MID may
not be created on I/O failure, under which memory region is deregistered when
write data context is released.

Signed-off-by: Long Li <[email protected]>
---
fs/cifs/cifsglob.h | 3 +++
fs/cifs/cifssmb.c | 7 ++++++
fs/cifs/smb2pdu.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++---
3 files changed, 72 insertions(+), 3 deletions(-)

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 3fb1a2f..22bfda0 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1174,6 +1174,9 @@ struct cifs_writedata {
pid_t pid;
unsigned int bytes;
int result;
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ struct smbd_mr *mr;
+#endif
unsigned int pagesz;
unsigned int tailsz;
unsigned int credits;
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 35dc5bf..66d1ebf 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -43,6 +43,7 @@
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "fscache.h"
+#include "smbdirect.h"

#ifdef CONFIG_CIFS_POSIX
static struct {
@@ -1923,6 +1924,12 @@ cifs_writedata_release(struct kref *refcount)
{
struct cifs_writedata *wdata = container_of(refcount,
struct cifs_writedata, refcount);
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ if (wdata->mr) {
+ smbd_deregister_mr(wdata->mr);
+ wdata->mr = NULL;
+ }
+#endif

if (wdata->cfile)
cifsFileInfo_put(wdata->cfile);
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index c0dc049..908d777 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -48,6 +48,7 @@
#include "smb2glob.h"
#include "cifspdu.h"
#include "cifs_spnego.h"
+#include "smbdirect.h"

/*
* The following table defines the expected "StructureSize" of SMB2 requests
@@ -2728,7 +2729,19 @@ smb2_writev_callback(struct mid_q_entry *mid)
wdata->result = -EIO;
break;
}
-
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ /*
+ * If this wdata has a memory registered, the MR can be freed
+ * The number of MRs available is limited, it's important to recover
+ * used MR as soon as I/O is finished. Hold MR longer in the later
+ * I/O process can possibly result in I/O deadlock due to lack of MR
+ * to send request on I/O retry
+ */
+ if (wdata->mr) {
+ smbd_deregister_mr(wdata->mr);
+ wdata->mr = NULL;
+ }
+#endif
if (wdata->result)
cifs_stats_fail_inc(tcon, SMB2_WRITE_HE);

@@ -2780,7 +2793,42 @@ smb2_async_writev(struct cifs_writedata *wdata,
req->DataOffset = cpu_to_le16(
offsetof(struct smb2_write_req, Buffer));
req->RemainingBytes = 0;
-
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ /*
+ * If we want to do a server RDMA read, fill in and append
+ * smbd_buffer_descriptor_v1 to the end of write request
+ */
+ if (server->rdma && wdata->bytes >=
+ server->smbd_conn->rdma_readwrite_threshold) {
+
+ struct smbd_buffer_descriptor_v1 *v1;
+ bool need_invalidate = server->dialect == SMB30_PROT_ID;
+
+ wdata->mr = smbd_register_mr(
+ server->smbd_conn, wdata->pages,
+ wdata->nr_pages, wdata->tailsz,
+ false, need_invalidate);
+ if (!wdata->mr) {
+ rc = -ENOBUFS;
+ goto async_writev_out;
+ }
+ req->Length = 0;
+ req->DataOffset = 0;
+ req->RemainingBytes =
+ (wdata->nr_pages-1)*PAGE_SIZE + wdata->tailsz;
+ req->Channel = SMB2_CHANNEL_RDMA_V1_INVALIDATE;
+ if (need_invalidate)
+ req->Channel = SMB2_CHANNEL_RDMA_V1;
+ req->WriteChannelInfoOffset =
+ offsetof(struct smb2_write_req, Buffer);
+ req->WriteChannelInfoLength =
+ sizeof(struct smbd_buffer_descriptor_v1);
+ v1 = (struct smbd_buffer_descriptor_v1 *) &req->Buffer[0];
+ v1->offset = wdata->mr->mr->iova;
+ v1->token = wdata->mr->mr->rkey;
+ v1->length = wdata->mr->mr->length;
+ }
+#endif
/* 4 for rfc1002 length field and 1 for Buffer */
iov[0].iov_len = 4;
rfc1002_marker = cpu_to_be32(total_len - 1 + wdata->bytes);
@@ -2794,11 +2842,22 @@ smb2_async_writev(struct cifs_writedata *wdata,
rqst.rq_npages = wdata->nr_pages;
rqst.rq_pagesz = wdata->pagesz;
rqst.rq_tailsz = wdata->tailsz;
-
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ if (wdata->mr) {
+ iov[1].iov_len += sizeof(struct smbd_buffer_descriptor_v1);
+ rqst.rq_npages = 0;
+ }
+#endif
cifs_dbg(FYI, "async write at %llu %u bytes\n",
wdata->offset, wdata->bytes);

+#ifdef CONFIG_CIFS_SMB_DIRECT
+ /* For RDMA read, I/O size is in RemainingBytes not in Length */
+ if (!wdata->mr)
+ req->Length = cpu_to_le32(wdata->bytes);
+#else
req->Length = cpu_to_le32(wdata->bytes);
+#endif

if (wdata->credits) {
shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(wdata->bytes,
--
2.7.4


From 1584808246833488230@xxx Wed Nov 22 22:48:41 +0000 2017
X-GM-THRID: 1584807290218277234
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread

2017-11-23 00:44:03

by Long Li

[permalink] [raw]
Subject: [Patch v8 10/16] CIFS: SMBD: Upper layer sends data via RDMA send

From: Long Li <[email protected]>

With SMB Direct connected, use it for sending data via RDMA send.

Signed-off-by: Long Li <[email protected]>
---
fs/cifs/transport.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index e678307..4001842 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -37,6 +37,7 @@
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
+#include "smbdirect.h"

void
cifs_wake_up_task(struct mid_q_entry *mid)
@@ -229,7 +230,10 @@ __smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
struct socket *ssocket = server->ssocket;
struct msghdr smb_msg;
int val = 1;
-
+ if (cifs_rdma_enabled(server) && server->smbd_conn) {
+ rc = smbd_send(server->smbd_conn, rqst);
+ goto smbd_done;
+ }
if (ssocket == NULL)
return -ENOTSOCK;

@@ -298,7 +302,7 @@ __smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
*/
server->tcpStatus = CifsNeedReconnect;
}
-
+smbd_done:
if (rc < 0 && rc != -EINTR)
cifs_dbg(VFS, "Error %d sending data on socket to server\n",
rc);
--
2.7.4


From 1584803482186693621@xxx Wed Nov 22 21:32:57 +0000 2017
X-GM-THRID: 1584803482186693621
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread

2017-11-23 00:44:17

by Long Li

[permalink] [raw]
Subject: [Patch v8 06/16] CIFS: SMBD: Set SMB Direct maximum read or write size for I/O

From: Long Li <[email protected]>

When connecting over SMB Direct, the transport negotiates its maximum I/O sizes
with the server and determines how to choose to do RDMA send/recv vs
read/write. Expose these maximum I/O sizes to upper layer so we will get the
correct sized payloads.

Signed-off-by: Long Li <[email protected]>
---
fs/cifs/smb2ops.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index e067404..5e6a5e6 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -32,6 +32,7 @@
#include "smb2status.h"
#include "smb2glob.h"
#include "cifs_ioctl.h"
+#include "smbdirect.h"

static int
change_conf(struct TCP_Server_Info *server)
@@ -250,7 +251,11 @@ smb2_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
/* start with specified wsize, or default */
wsize = volume_info->wsize ? volume_info->wsize : CIFS_DEFAULT_IOSIZE;
wsize = min_t(unsigned int, wsize, server->max_write);
-
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ if (server->rdma)
+ wsize = min_t(unsigned int,
+ wsize, server->smbd_conn->max_readwrite_size);
+#endif
if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
wsize = min_t(unsigned int, wsize, SMB2_MAX_BUFFER_SIZE);

@@ -266,6 +271,11 @@ smb2_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
/* start with specified rsize, or default */
rsize = volume_info->rsize ? volume_info->rsize : CIFS_DEFAULT_IOSIZE;
rsize = min_t(unsigned int, rsize, server->max_read);
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ if (server->rdma)
+ rsize = min_t(unsigned int,
+ rsize, server->smbd_conn->max_readwrite_size);
+#endif

if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
rsize = min_t(unsigned int, rsize, SMB2_MAX_BUFFER_SIZE);
--
2.7.4


From 1584802809631084598@xxx Wed Nov 22 21:22:16 +0000 2017
X-GM-THRID: 1584802809631084598
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread

2017-11-23 00:43:07

by Long Li

[permalink] [raw]
Subject: [Patch v8 11/16] CIFS: SMBD: Implement RDMA memory registration

From: Long Li <[email protected]>

Memory registration is used for transferring payload via RDMA read or write.
After I/O is done, memory registrations are recovered and reused. This
process can be time consuming and is done in a work queue.

Signed-off-by: Long Li <[email protected]>
---
fs/cifs/smbdirect.c | 421 ++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/cifs/smbdirect.h | 53 +++++++
2 files changed, 474 insertions(+)

diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index cb062e2..238e310 100644
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -48,6 +48,9 @@ static int smbd_post_send_page(struct smbd_connection *info,
struct page *page, unsigned long offset,
size_t size, int remaining_data_length);

+static void destroy_mr_list(struct smbd_connection *info);
+static int allocate_mr_list(struct smbd_connection *info);
+
/* SMBD version number */
#define SMBD_V1 0x0100

@@ -198,6 +201,12 @@ static void smbd_destroy_rdma_work(struct work_struct *work)
wait_event(info->wait_send_payload_pending,
atomic_read(&info->send_payload_pending) == 0);

+ log_rdma_event(INFO, "freeing mr list\n");
+ wake_up_interruptible_all(&info->wait_mr);
+ wait_event(info->wait_for_mr_cleanup,
+ atomic_read(&info->mr_used_count) == 0);
+ destroy_mr_list(info);
+
/* It's not posssible for upper layer to get to reassembly */
log_rdma_event(INFO, "drain the reassembly queue\n");
do {
@@ -453,6 +462,16 @@ static bool process_negotiation_response(
}
info->max_fragmented_send_size =
le32_to_cpu(packet->max_fragmented_size);
+ info->rdma_readwrite_threshold =
+ rdma_readwrite_threshold > info->max_fragmented_send_size ?
+ info->max_fragmented_send_size :
+ rdma_readwrite_threshold;
+
+
+ info->max_readwrite_size = min_t(u32,
+ le32_to_cpu(packet->max_readwrite_size),
+ info->max_frmr_depth * PAGE_SIZE);
+ info->max_frmr_depth = info->max_readwrite_size / PAGE_SIZE;

return true;
}
@@ -748,6 +767,12 @@ static int smbd_ia_open(
rc = -EPROTONOSUPPORT;
goto out2;
}
+ info->max_frmr_depth = min_t(int,
+ smbd_max_frmr_depth,
+ info->id->device->attrs.max_fast_reg_page_list_len);
+ info->mr_type = IB_MR_TYPE_MEM_REG;
+ if (info->id->device->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG)
+ info->mr_type = IB_MR_TYPE_SG_GAPS;

info->pd = ib_alloc_pd(info->id->device, 0);
if (IS_ERR(info->pd)) {
@@ -1582,6 +1607,8 @@ struct smbd_connection *_smbd_get_connection(
struct rdma_conn_param conn_param;
struct ib_qp_init_attr qp_attr;
struct sockaddr_in *addr_in = (struct sockaddr_in *) dstaddr;
+ struct ib_port_immutable port_immutable;
+ u32 ird_ord_hdr[2];

info = kzalloc(sizeof(struct smbd_connection), GFP_KERNEL);
if (!info)
@@ -1670,6 +1697,28 @@ struct smbd_connection *_smbd_get_connection(
memset(&conn_param, 0, sizeof(conn_param));
conn_param.initiator_depth = 0;

+ conn_param.responder_resources =
+ info->id->device->attrs.max_qp_rd_atom
+ < SMBD_CM_RESPONDER_RESOURCES ?
+ info->id->device->attrs.max_qp_rd_atom :
+ SMBD_CM_RESPONDER_RESOURCES;
+ info->responder_resources = conn_param.responder_resources;
+ log_rdma_mr(INFO, "responder_resources=%d\n",
+ info->responder_resources);
+
+ /* Need to send IRD/ORD in private data for iWARP */
+ info->id->device->get_port_immutable(
+ info->id->device, info->id->port_num, &port_immutable);
+ if (port_immutable.core_cap_flags & RDMA_CORE_PORT_IWARP) {
+ ird_ord_hdr[0] = info->responder_resources;
+ ird_ord_hdr[1] = 1;
+ conn_param.private_data = ird_ord_hdr;
+ conn_param.private_data_len = sizeof(ird_ord_hdr);
+ } else {
+ conn_param.private_data = NULL;
+ conn_param.private_data_len = 0;
+ }
+
conn_param.retry_count = SMBD_CM_RETRY;
conn_param.rnr_retry_count = SMBD_CM_RNR_RETRY;
conn_param.flow_control = 0;
@@ -1734,8 +1783,19 @@ struct smbd_connection *_smbd_get_connection(
goto negotiation_failed;
}

+ rc = allocate_mr_list(info);
+ if (rc) {
+ log_rdma_mr(ERR, "memory registration allocation failed\n");
+ goto allocate_mr_failed;
+ }
+
return info;

+allocate_mr_failed:
+ /* At this point, need to a full transport shutdown */
+ smbd_destroy(info);
+ return NULL;
+
negotiation_failed:
cancel_delayed_work_sync(&info->idle_timer_work);
destroy_caches_and_workqueue(info);
@@ -2189,3 +2249,364 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst)

return rc;
}
+
+static void register_mr_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+ struct smbd_mr *mr;
+ struct ib_cqe *cqe;
+
+ if (wc->status) {
+ log_rdma_mr(ERR, "status=%d\n", wc->status);
+ cqe = wc->wr_cqe;
+ mr = container_of(cqe, struct smbd_mr, cqe);
+ smbd_disconnect_rdma_connection(mr->conn);
+ }
+}
+
+/*
+ * The work queue function that recovers MRs
+ * We need to call ib_dereg_mr() and ib_alloc_mr() before this MR can be used
+ * again. Both calls are slow, so finish them in a workqueue. This will not
+ * block I/O path.
+ * There is one workqueue that recovers MRs, there is no need to lock as the
+ * I/O requests calling smbd_register_mr will never update the links in the
+ * mr_list.
+ */
+static void smbd_mr_recovery_work(struct work_struct *work)
+{
+ struct smbd_connection *info =
+ container_of(work, struct smbd_connection, mr_recovery_work);
+ struct smbd_mr *smbdirect_mr;
+ int rc;
+
+ list_for_each_entry(smbdirect_mr, &info->mr_list, list) {
+ if (smbdirect_mr->state == MR_INVALIDATED ||
+ smbdirect_mr->state == MR_ERROR) {
+
+ if (smbdirect_mr->state == MR_INVALIDATED) {
+ ib_dma_unmap_sg(
+ info->id->device, smbdirect_mr->sgl,
+ smbdirect_mr->sgl_count,
+ smbdirect_mr->dir);
+ smbdirect_mr->state = MR_READY;
+ } else if (smbdirect_mr->state == MR_ERROR) {
+
+ /* recover this MR entry */
+ rc = ib_dereg_mr(smbdirect_mr->mr);
+ if (rc) {
+ log_rdma_mr(ERR,
+ "ib_dereg_mr faield rc=%x\n",
+ rc);
+ smbd_disconnect_rdma_connection(info);
+ }
+
+ smbdirect_mr->mr = ib_alloc_mr(
+ info->pd, info->mr_type,
+ info->max_frmr_depth);
+ if (IS_ERR(smbdirect_mr->mr)) {
+ log_rdma_mr(ERR,
+ "ib_alloc_mr failed mr_type=%x "
+ "max_frmr_depth=%x\n",
+ info->mr_type,
+ info->max_frmr_depth);
+ smbd_disconnect_rdma_connection(info);
+ }
+
+ smbdirect_mr->state = MR_READY;
+ }
+ /* smbdirect_mr->state is updated by this function
+ * and is read and updated by I/O issuing CPUs trying
+ * to get a MR, the call to atomic_inc_return
+ * implicates a memory barrier and guarantees this
+ * value is updated before waking up any calls to
+ * get_mr() from the I/O issuing CPUs
+ */
+ if (atomic_inc_return(&info->mr_ready_count) == 1)
+ wake_up_interruptible(&info->wait_mr);
+ }
+ }
+}
+
+static void destroy_mr_list(struct smbd_connection *info)
+{
+ struct smbd_mr *mr, *tmp;
+
+ cancel_work_sync(&info->mr_recovery_work);
+ list_for_each_entry_safe(mr, tmp, &info->mr_list, list) {
+ if (mr->state == MR_INVALIDATED)
+ ib_dma_unmap_sg(info->id->device, mr->sgl,
+ mr->sgl_count, mr->dir);
+ ib_dereg_mr(mr->mr);
+ kfree(mr->sgl);
+ kfree(mr);
+ }
+}
+
+/*
+ * Allocate MRs used for RDMA read/write
+ * The number of MRs will not exceed hardware capability in responder_resources
+ * All MRs are kept in mr_list. The MR can be recovered after it's used
+ * Recovery is done in smbd_mr_recovery_work. The content of list entry changes
+ * as MRs are used and recovered for I/O, but the list links will not change
+ */
+static int allocate_mr_list(struct smbd_connection *info)
+{
+ int i;
+ struct smbd_mr *smbdirect_mr, *tmp;
+
+ INIT_LIST_HEAD(&info->mr_list);
+ init_waitqueue_head(&info->wait_mr);
+ spin_lock_init(&info->mr_list_lock);
+ atomic_set(&info->mr_ready_count, 0);
+ atomic_set(&info->mr_used_count, 0);
+ init_waitqueue_head(&info->wait_for_mr_cleanup);
+ /* Allocate more MRs (2x) than hardware responder_resources */
+ for (i = 0; i < info->responder_resources * 2; i++) {
+ smbdirect_mr = kzalloc(sizeof(*smbdirect_mr), GFP_KERNEL);
+ if (!smbdirect_mr)
+ goto out;
+ smbdirect_mr->mr = ib_alloc_mr(info->pd, info->mr_type,
+ info->max_frmr_depth);
+ if (IS_ERR(smbdirect_mr->mr)) {
+ log_rdma_mr(ERR, "ib_alloc_mr failed mr_type=%x "
+ "max_frmr_depth=%x\n",
+ info->mr_type, info->max_frmr_depth);
+ goto out;
+ }
+ smbdirect_mr->sgl = kcalloc(
+ info->max_frmr_depth,
+ sizeof(struct scatterlist),
+ GFP_KERNEL);
+ if (!smbdirect_mr->sgl) {
+ log_rdma_mr(ERR, "failed to allocate sgl\n");
+ ib_dereg_mr(smbdirect_mr->mr);
+ goto out;
+ }
+ smbdirect_mr->state = MR_READY;
+ smbdirect_mr->conn = info;
+
+ list_add_tail(&smbdirect_mr->list, &info->mr_list);
+ atomic_inc(&info->mr_ready_count);
+ }
+ INIT_WORK(&info->mr_recovery_work, smbd_mr_recovery_work);
+ return 0;
+
+out:
+ kfree(smbdirect_mr);
+
+ list_for_each_entry_safe(smbdirect_mr, tmp, &info->mr_list, list) {
+ ib_dereg_mr(smbdirect_mr->mr);
+ kfree(smbdirect_mr->sgl);
+ kfree(smbdirect_mr);
+ }
+ return -ENOMEM;
+}
+
+/*
+ * Get a MR from mr_list. This function waits until there is at least one
+ * MR available in the list. It may access the list while the
+ * smbd_mr_recovery_work is recovering the MR list. This doesn't need a lock
+ * as they never modify the same places. However, there may be several CPUs
+ * issueing I/O trying to get MR at the same time, mr_list_lock is used to
+ * protect this situation.
+ */
+static struct smbd_mr *get_mr(struct smbd_connection *info)
+{
+ struct smbd_mr *ret;
+ int rc;
+again:
+ rc = wait_event_interruptible(info->wait_mr,
+ atomic_read(&info->mr_ready_count) ||
+ info->transport_status != SMBD_CONNECTED);
+ if (rc) {
+ log_rdma_mr(ERR, "wait_event_interruptible rc=%x\n", rc);
+ return NULL;
+ }
+
+ if (info->transport_status != SMBD_CONNECTED) {
+ log_rdma_mr(ERR, "info->transport_status=%x\n",
+ info->transport_status);
+ return NULL;
+ }
+
+ spin_lock(&info->mr_list_lock);
+ list_for_each_entry(ret, &info->mr_list, list) {
+ if (ret->state == MR_READY) {
+ ret->state = MR_REGISTERED;
+ spin_unlock(&info->mr_list_lock);
+ atomic_dec(&info->mr_ready_count);
+ atomic_inc(&info->mr_used_count);
+ return ret;
+ }
+ }
+
+ spin_unlock(&info->mr_list_lock);
+ /*
+ * It is possible that we can get a MR because other processes may try
+ * to acquire a MR at the same time. If this is the case, retry it.
+ */
+ goto again;
+}
+
+/*
+ * Register memory for RDMA read/write
+ * pages[]: the list of pages to register memory with
+ * num_pages: the number of pages to register
+ * tailsz: if non-zero, the bytes to register in the last page
+ * writing: true if this is a RDMA write (SMB read), false for RDMA read
+ * need_invalidate: true if this MR needs to be locally invalidated after I/O
+ * return value: the MR registered, NULL if failed.
+ */
+struct smbd_mr *smbd_register_mr(
+ struct smbd_connection *info, struct page *pages[], int num_pages,
+ int tailsz, bool writing, bool need_invalidate)
+{
+ struct smbd_mr *smbdirect_mr;
+ int rc, i;
+ enum dma_data_direction dir;
+ struct ib_reg_wr *reg_wr;
+ struct ib_send_wr *bad_wr;
+
+ if (num_pages > info->max_frmr_depth) {
+ log_rdma_mr(ERR, "num_pages=%d max_frmr_depth=%d\n",
+ num_pages, info->max_frmr_depth);
+ return NULL;
+ }
+
+ smbdirect_mr = get_mr(info);
+ if (!smbdirect_mr) {
+ log_rdma_mr(ERR, "get_mr returning NULL\n");
+ return NULL;
+ }
+ smbdirect_mr->need_invalidate = need_invalidate;
+ smbdirect_mr->sgl_count = num_pages;
+ sg_init_table(smbdirect_mr->sgl, num_pages);
+
+ for (i = 0; i < num_pages - 1; i++)
+ sg_set_page(&smbdirect_mr->sgl[i], pages[i], PAGE_SIZE, 0);
+
+ sg_set_page(&smbdirect_mr->sgl[i], pages[i],
+ tailsz ? tailsz : PAGE_SIZE, 0);
+
+ dir = writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+ smbdirect_mr->dir = dir;
+ rc = ib_dma_map_sg(info->id->device, smbdirect_mr->sgl, num_pages, dir);
+ if (!rc) {
+ log_rdma_mr(INFO, "ib_dma_map_sg num_pages=%x dir=%x rc=%x\n",
+ num_pages, dir, rc);
+ goto dma_map_error;
+ }
+
+ rc = ib_map_mr_sg(smbdirect_mr->mr, smbdirect_mr->sgl, num_pages,
+ NULL, PAGE_SIZE);
+ if (rc != num_pages) {
+ log_rdma_mr(INFO,
+ "ib_map_mr_sg failed rc = %x num_pages = %x\n",
+ rc, num_pages);
+ goto map_mr_error;
+ }
+
+ ib_update_fast_reg_key(smbdirect_mr->mr,
+ ib_inc_rkey(smbdirect_mr->mr->rkey));
+ reg_wr = &smbdirect_mr->wr;
+ reg_wr->wr.opcode = IB_WR_REG_MR;
+ smbdirect_mr->cqe.done = register_mr_done;
+ reg_wr->wr.wr_cqe = &smbdirect_mr->cqe;
+ reg_wr->wr.num_sge = 0;
+ reg_wr->wr.send_flags = IB_SEND_SIGNALED;
+ reg_wr->mr = smbdirect_mr->mr;
+ reg_wr->key = smbdirect_mr->mr->rkey;
+ reg_wr->access = writing ?
+ IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
+ IB_ACCESS_REMOTE_READ;
+
+ /*
+ * There is no need for waiting for complemtion on ib_post_send
+ * on IB_WR_REG_MR. Hardware enforces a barrier and order of execution
+ * on the next ib_post_send when we actaully send I/O to remote peer
+ */
+ rc = ib_post_send(info->id->qp, &reg_wr->wr, &bad_wr);
+ if (!rc)
+ return smbdirect_mr;
+
+ log_rdma_mr(ERR, "ib_post_send failed rc=%x reg_wr->key=%x\n",
+ rc, reg_wr->key);
+
+ /* If all failed, attempt to recover this MR by setting it MR_ERROR*/
+map_mr_error:
+ ib_dma_unmap_sg(info->id->device, smbdirect_mr->sgl,
+ smbdirect_mr->sgl_count, smbdirect_mr->dir);
+
+dma_map_error:
+ smbdirect_mr->state = MR_ERROR;
+ if (atomic_dec_and_test(&info->mr_used_count))
+ wake_up(&info->wait_for_mr_cleanup);
+
+ return NULL;
+}
+
+static void local_inv_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+ struct smbd_mr *smbdirect_mr;
+ struct ib_cqe *cqe;
+
+ cqe = wc->wr_cqe;
+ smbdirect_mr = container_of(cqe, struct smbd_mr, cqe);
+ smbdirect_mr->state = MR_INVALIDATED;
+ if (wc->status != IB_WC_SUCCESS) {
+ log_rdma_mr(ERR, "invalidate failed status=%x\n", wc->status);
+ smbdirect_mr->state = MR_ERROR;
+ }
+ complete(&smbdirect_mr->invalidate_done);
+}
+
+/*
+ * Deregister a MR after I/O is done
+ * This function may wait if remote invalidation is not used
+ * and we have to locally invalidate the buffer to prevent data is being
+ * modified by remote peer after upper layer consumes it
+ */
+int smbd_deregister_mr(struct smbd_mr *smbdirect_mr)
+{
+ struct ib_send_wr *wr, *bad_wr;
+ struct smbd_connection *info = smbdirect_mr->conn;
+ int rc = 0;
+
+ if (smbdirect_mr->need_invalidate) {
+ /* Need to finish local invalidation before returning */
+ wr = &smbdirect_mr->inv_wr;
+ wr->opcode = IB_WR_LOCAL_INV;
+ smbdirect_mr->cqe.done = local_inv_done;
+ wr->wr_cqe = &smbdirect_mr->cqe;
+ wr->num_sge = 0;
+ wr->ex.invalidate_rkey = smbdirect_mr->mr->rkey;
+ wr->send_flags = IB_SEND_SIGNALED;
+
+ init_completion(&smbdirect_mr->invalidate_done);
+ rc = ib_post_send(info->id->qp, wr, &bad_wr);
+ if (rc) {
+ log_rdma_mr(ERR, "ib_post_send failed rc=%x\n", rc);
+ smbd_disconnect_rdma_connection(info);
+ goto done;
+ }
+ wait_for_completion(&smbdirect_mr->invalidate_done);
+ smbdirect_mr->need_invalidate = false;
+ } else
+ /*
+ * For remote invalidation, just set it to MR_INVALIDATED
+ * and defer to mr_recovery_work to recover the MR for next use
+ */
+ smbdirect_mr->state = MR_INVALIDATED;
+
+ /*
+ * Schedule the work to do MR recovery for future I/Os
+ * MR recovery is slow and we don't want it to block the current I/O
+ */
+ queue_work(info->workqueue, &info->mr_recovery_work);
+
+done:
+ if (atomic_dec_and_test(&info->mr_used_count))
+ wake_up(&info->wait_for_mr_cleanup);
+
+ return rc;
+}
diff --git a/fs/cifs/smbdirect.h b/fs/cifs/smbdirect.h
index d1cafa1..c8a274c 100644
--- a/fs/cifs/smbdirect.h
+++ b/fs/cifs/smbdirect.h
@@ -90,6 +90,29 @@ struct smbd_connection {
int receive_credit_target;
int fragment_reassembly_remaining;

+ /* Memory registrations */
+ /* Maximum number of RDMA read/write outstanding on this connection */
+ int responder_resources;
+ /* Maximum number of SGEs in a RDMA write/read */
+ int max_frmr_depth;
+ /*
+ * If payload is less than or equal to the threshold,
+ * use RDMA send/recv to send upper layer I/O.
+ * If payload is more than the threshold,
+ * use RDMA read/write through memory registration for I/O.
+ */
+ int rdma_readwrite_threshold;
+ enum ib_mr_type mr_type;
+ struct list_head mr_list;
+ spinlock_t mr_list_lock;
+ /* The number of available MRs ready for memory registration */
+ atomic_t mr_ready_count;
+ atomic_t mr_used_count;
+ wait_queue_head_t wait_mr;
+ struct work_struct mr_recovery_work;
+ /* Used by transport to wait until all MRs are returned */
+ wait_queue_head_t wait_for_mr_cleanup;
+
/* Activity accoutning */
/* Pending reqeusts issued from upper layer */
int smbd_send_pending;
@@ -262,6 +285,36 @@ void smbd_destroy(struct smbd_connection *info);
int smbd_recv(struct smbd_connection *info, struct msghdr *msg);
int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst);

+enum mr_state {
+ MR_READY,
+ MR_REGISTERED,
+ MR_INVALIDATED,
+ MR_ERROR
+};
+
+struct smbd_mr {
+ struct smbd_connection *conn;
+ struct list_head list;
+ enum mr_state state;
+ struct ib_mr *mr;
+ struct scatterlist *sgl;
+ int sgl_count;
+ enum dma_data_direction dir;
+ union {
+ struct ib_reg_wr wr;
+ struct ib_send_wr inv_wr;
+ };
+ struct ib_cqe cqe;
+ bool need_invalidate;
+ struct completion invalidate_done;
+};
+
+/* Interfaces to register and deregister MR for RDMA read/write */
+struct smbd_mr *smbd_register_mr(
+ struct smbd_connection *info, struct page *pages[], int num_pages,
+ int tailsz, bool writing, bool need_invalidate);
+int smbd_deregister_mr(struct smbd_mr *mr);
+
#else
#define cifs_rdma_enabled(server) 0
struct smbd_connection {};
--
2.7.4


From 1584959828891329739@xxx Fri Nov 24 14:58:01 +0000 2017
X-GM-THRID: 1584956324922793949
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread

2017-11-23 00:42:55

by Long Li

[permalink] [raw]
Subject: [Patch v8 02/16] CIFS: SMBD: Implement function to reconnect to a SMB Direct transport

From: Long Li <[email protected]>

Add function to implement a reconnect to SMB Direct. This involves tearing down
the current connection and establishing/negotiating a new connection.

Signed-off-by: Long Li <[email protected]>
---
fs/cifs/smbdirect.c | 36 ++++++++++++++++++++++++++++++++++++
fs/cifs/smbdirect.h | 4 ++++
2 files changed, 40 insertions(+)

diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index 862cdf9..a96058a 100644
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -1387,6 +1387,42 @@ static void idle_connection_timer(struct work_struct *work)
info->keep_alive_interval*HZ);
}

+/*
+ * Reconnect this SMBD connection, called from upper layer
+ * return value: 0 on success, or actual error code
+ */
+int smbd_reconnect(struct TCP_Server_Info *server)
+{
+ log_rdma_event(INFO, "reconnecting rdma session\n");
+
+ if (!server->smbd_conn) {
+ log_rdma_event(ERR, "rdma session already destroyed\n");
+ return -EINVAL;
+ }
+
+ /*
+ * This is possible if transport is disconnected and we haven't received
+ * notification from RDMA, but upper layer has detected timeout
+ */
+ if (server->smbd_conn->transport_status == SMBD_CONNECTED) {
+ log_rdma_event(INFO, "disconnecting transport\n");
+ smbd_disconnect_rdma_connection(server->smbd_conn);
+ }
+
+ /* wait until the transport is destroyed */
+ wait_event(server->smbd_conn->wait_destroy,
+ server->smbd_conn->transport_status == SMBD_DESTROYED);
+
+ destroy_workqueue(server->smbd_conn->workqueue);
+ kfree(server->smbd_conn);
+
+ log_rdma_event(INFO, "creating rdma session\n");
+ server->smbd_conn = smbd_get_connection(
+ server, (struct sockaddr *) &server->dstaddr);
+
+ return server->smbd_conn ? 0 : -ENOENT;
+}
+
static void destroy_caches_and_workqueue(struct smbd_connection *info)
{
destroy_receive_buffers(info);
diff --git a/fs/cifs/smbdirect.h b/fs/cifs/smbdirect.h
index 25b3782..8948f06 100644
--- a/fs/cifs/smbdirect.h
+++ b/fs/cifs/smbdirect.h
@@ -247,11 +247,15 @@ struct smbd_response {
struct smbd_connection *smbd_get_connection(
struct TCP_Server_Info *server, struct sockaddr *dstaddr);

+/* Reconnect SMBDirect session */
+int smbd_reconnect(struct TCP_Server_Info *server);
+
#else
#define cifs_rdma_enabled(server) 0
struct smbd_connection {};
static inline void *smbd_get_connection(
struct TCP_Server_Info *server, struct sockaddr *dstaddr) {return NULL;}
+static inline int smbd_reconnect(struct TCP_Server_Info *server) {return -1;}
#endif

#endif
--
2.7.4


From 1584808775033030189@xxx Wed Nov 22 22:57:05 +0000 2017
X-GM-THRID: 1584808775033030189
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread

2017-11-23 00:44:45

by Long Li

[permalink] [raw]
Subject: [Patch v8 01/16] CIFS: SMBD: Upper layer connects to SMBDirect session

From: Long Li <[email protected]>

When "rdma" is specified in the mount option, make CIFS connect to
SMB Direct.

Signed-off-by: Long Li <[email protected]>
---
fs/cifs/connect.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 64be6f9..fafaecb 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -44,7 +44,6 @@
#include <net/ipv6.h>
#include <linux/parser.h>
#include <linux/bvec.h>
-
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
@@ -56,6 +55,7 @@
#include "rfc1002pdu.h"
#include "fscache.h"
#include "smb2proto.h"
+#include "smbdirect.h"

#define CIFS_PORT 445
#define RFC1001_PORT 139
@@ -2310,13 +2310,29 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
tcp_ses->echo_interval = volume_info->echo_interval * HZ;
else
tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
-
+ if (tcp_ses->rdma) {
+#ifndef CONFIG_CIFS_SMB_DIRECT
+ cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
+ rc = -ENOENT;
+ goto out_err_crypto_release;
+#endif
+ tcp_ses->smbd_conn = smbd_get_connection(
+ tcp_ses, (struct sockaddr *)&volume_info->dstaddr);
+ if (tcp_ses->smbd_conn) {
+ cifs_dbg(VFS, "RDMA transport established\n");
+ rc = 0;
+ goto smbd_connected;
+ } else {
+ rc = -ENOENT;
+ goto out_err_crypto_release;
+ }
+ }
rc = ip_connect(tcp_ses);
if (rc < 0) {
cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
goto out_err_crypto_release;
}
-
+smbd_connected:
/*
* since we're in a cifs function already, we know that
* this will succeed. No need for try_module_get().
--
2.7.4


From 1584761022419102322@xxx Wed Nov 22 10:18:04 +0000 2017
X-GM-THRID: 1584761022419102322
X-Gmail-Labels: Inbox,Category Promotions,HistoricalUnread