lkml.org 
[lkml]   [2020]   [Mar]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[Patch v2] cifs: smbd: Calculate the correct maximum packet size for segmented SMBDirect send/receive
Date
From: Long Li <longli@microsoft.com>

The packet size needs to take account of SMB2 header size and possible
encryption header size. This is only done when signing is used and it is for
RDMA send/receive, not read/write.

Also remove the dead SMBD code in smb2_negotiate_r(w)size.

Signed-off-by: Long Li <longli@microsoft.com>
---

Change since v1: defined SMB2_READWRITE_PDU_HEADER_SIZE for header size and corrected miscalculation

fs/cifs/smb2ops.c | 38 ++++++++++++++++----------------------
fs/cifs/smb2pdu.h | 3 +++
fs/cifs/smbdirect.c | 3 +--
3 files changed, 20 insertions(+), 24 deletions(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 9c9258fc8756..b36c46f48705 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -328,16 +328,6 @@ 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) {
- if (server->sign)
- wsize = min_t(unsigned int,
- wsize, server->smbd_conn->max_fragmented_send_size);
- else
- 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);

@@ -356,8 +346,15 @@ smb3_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
#ifdef CONFIG_CIFS_SMB_DIRECT
if (server->rdma) {
if (server->sign)
+ /*
+ * Account for SMB2 data transfer packet header and
+ * possible encryption header
+ */
wsize = min_t(unsigned int,
- wsize, server->smbd_conn->max_fragmented_send_size);
+ wsize,
+ server->smbd_conn->max_fragmented_send_size -
+ SMB2_READWRITE_PDU_HEADER_SIZE -
+ sizeof(struct smb2_transform_hdr));
else
wsize = min_t(unsigned int,
wsize, server->smbd_conn->max_readwrite_size);
@@ -378,16 +375,6 @@ 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) {
- if (server->sign)
- rsize = min_t(unsigned int,
- rsize, server->smbd_conn->max_fragmented_recv_size);
- else
- 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);
@@ -407,8 +394,15 @@ smb3_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
#ifdef CONFIG_CIFS_SMB_DIRECT
if (server->rdma) {
if (server->sign)
+ /*
+ * Account for SMB2 data transfer packet header and
+ * possible encryption header
+ */
rsize = min_t(unsigned int,
- rsize, server->smbd_conn->max_fragmented_recv_size);
+ rsize,
+ server->smbd_conn->max_fragmented_recv_size -
+ SMB2_READWRITE_PDU_HEADER_SIZE -
+ sizeof(struct smb2_transform_hdr));
else
rsize = min_t(unsigned int,
rsize, server->smbd_conn->max_readwrite_size);
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index dda928d05c13..10acf90f858d 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -120,6 +120,9 @@ struct smb2_sync_hdr {
__u8 Signature[16];
} __packed;

+/* The total header size for SMB2 read and write */
+#define SMB2_READWRITE_PDU_HEADER_SIZE (48 + sizeof(struct smb2_sync_hdr))
+
struct smb2_sync_pdu {
struct smb2_sync_hdr sync_hdr;
__le16 StructureSize2; /* size of wct area (varies, request specific) */
diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index 5b1b97e9e0c9..a6ae29b3c4e7 100644
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -2097,8 +2097,7 @@ int smbd_send(struct TCP_Server_Info *server,
for (i = 0; i < num_rqst; i++)
remaining_data_length += smb_rqst_len(server, &rqst_array[i]);

- if (remaining_data_length + sizeof(struct smbd_data_transfer) >
- info->max_fragmented_send_size) {
+ if (remaining_data_length > info->max_fragmented_send_size) {
log_write(ERR, "payload size %d > max size %d\n",
remaining_data_length, info->max_fragmented_send_size);
rc = -EINVAL;
--
2.17.1
\
 
 \ /
  Last update: 2020-03-27 03:42    [W:0.024 / U:5.848 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site