CIFS: SMBD: Read correct returned data length for RDMA write (SMB read) I/O

This patch is for preparing upper layer doing SMB read via RDMA write.

When RDMA write is used for SMB read, the returned data length is in
DataRemaining in the response packet. Reading it properly by adding a
parameter to specifiy where the returned data length is.

Add the defition for memory registration to wdata and return the correct
length based on if RDMA write is used.

Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
This commit is contained in:
Long Li 2017-11-22 17:38:46 -07:00 committed by Steve French
parent db223a590d
commit 74dcf418fe
4 changed files with 30 additions and 7 deletions

View File

@ -230,8 +230,14 @@ struct smb_version_operations {
__u64 (*get_next_mid)(struct TCP_Server_Info *); __u64 (*get_next_mid)(struct TCP_Server_Info *);
/* data offset from read response message */ /* data offset from read response message */
unsigned int (*read_data_offset)(char *); unsigned int (*read_data_offset)(char *);
/* data length from read response message */ /*
unsigned int (*read_data_length)(char *); * Data length from read response message
* When in_remaining is true, the returned data length is in
* message field DataRemaining for out-of-band data read (e.g through
* Memory Registration RDMA write in SMBD).
* Otherwise, the returned data length is in message field DataLength.
*/
unsigned int (*read_data_length)(char *, bool in_remaining);
/* map smb to linux error */ /* map smb to linux error */
int (*map_error)(char *, bool); int (*map_error)(char *, bool);
/* find mid corresponding to the response message */ /* find mid corresponding to the response message */
@ -1152,6 +1158,9 @@ struct cifs_readdata {
struct cifs_readdata *rdata, struct cifs_readdata *rdata,
struct iov_iter *iter); struct iov_iter *iter);
struct kvec iov[2]; struct kvec iov[2];
#ifdef CONFIG_CIFS_SMB_DIRECT
struct smbd_mr *mr;
#endif
unsigned int pagesz; unsigned int pagesz;
unsigned int tailsz; unsigned int tailsz;
unsigned int credits; unsigned int credits;

View File

@ -1455,6 +1455,7 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
struct cifs_readdata *rdata = mid->callback_data; struct cifs_readdata *rdata = mid->callback_data;
char *buf = server->smallbuf; char *buf = server->smallbuf;
unsigned int buflen = get_rfc1002_length(buf) + 4; unsigned int buflen = get_rfc1002_length(buf) + 4;
bool use_rdma_mr = false;
cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n", cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n",
__func__, mid->mid, rdata->offset, rdata->bytes); __func__, mid->mid, rdata->offset, rdata->bytes);
@ -1543,8 +1544,11 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
rdata->iov[0].iov_base, server->total_read); rdata->iov[0].iov_base, server->total_read);
/* how much data is in the response? */ /* how much data is in the response? */
data_len = server->ops->read_data_length(buf); #ifdef CONFIG_CIFS_SMB_DIRECT
if (data_offset + data_len > buflen) { use_rdma_mr = rdata->mr;
#endif
data_len = server->ops->read_data_length(buf, use_rdma_mr);
if (!use_rdma_mr && (data_offset + data_len > buflen)) {
/* data_len is corrupt -- discard frame */ /* data_len is corrupt -- discard frame */
rdata->result = -EIO; rdata->result = -EIO;
return cifs_readv_discard(server, mid); return cifs_readv_discard(server, mid);

View File

@ -87,9 +87,11 @@ cifs_read_data_offset(char *buf)
} }
static unsigned int static unsigned int
cifs_read_data_length(char *buf) cifs_read_data_length(char *buf, bool in_remaining)
{ {
READ_RSP *rsp = (READ_RSP *)buf; READ_RSP *rsp = (READ_RSP *)buf;
/* It's a bug reading remaining data for SMB1 packets */
WARN_ON(in_remaining);
return (le16_to_cpu(rsp->DataLengthHigh) << 16) + return (le16_to_cpu(rsp->DataLengthHigh) << 16) +
le16_to_cpu(rsp->DataLength); le16_to_cpu(rsp->DataLength);
} }

View File

@ -957,9 +957,13 @@ smb2_read_data_offset(char *buf)
} }
static unsigned int static unsigned int
smb2_read_data_length(char *buf) smb2_read_data_length(char *buf, bool in_remaining)
{ {
struct smb2_read_rsp *rsp = (struct smb2_read_rsp *)buf; struct smb2_read_rsp *rsp = (struct smb2_read_rsp *)buf;
if (in_remaining)
return le32_to_cpu(rsp->DataRemaining);
return le32_to_cpu(rsp->DataLength); return le32_to_cpu(rsp->DataLength);
} }
@ -2421,6 +2425,7 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
struct iov_iter iter; struct iov_iter iter;
struct kvec iov; struct kvec iov;
int length; int length;
bool use_rdma_mr = false;
if (shdr->Command != SMB2_READ) { if (shdr->Command != SMB2_READ) {
cifs_dbg(VFS, "only big read responses are supported\n"); cifs_dbg(VFS, "only big read responses are supported\n");
@ -2447,7 +2452,10 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
} }
data_offset = server->ops->read_data_offset(buf) + 4; data_offset = server->ops->read_data_offset(buf) + 4;
data_len = server->ops->read_data_length(buf); #ifdef CONFIG_CIFS_SMB_DIRECT
use_rdma_mr = rdata->mr;
#endif
data_len = server->ops->read_data_length(buf, use_rdma_mr);
if (data_offset < server->vals->read_rsp_size) { if (data_offset < server->vals->read_rsp_size) {
/* /*