Commit 74dcf418 authored by Long Li's avatar Long Li Committed by Steve French
Browse files

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: default avatarLong Li <longli@microsoft.com>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
Reviewed-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: default avatarRonnie Sahlberg <lsahlber@redhat.com>
parent db223a59

fs/cifs/cifsglob.h

+11 −2
Original line number Diff line number Diff line
@@ -230,8 +230,14 @@ struct smb_version_operations { 
	__u64 (*get_next_mid)(struct TCP_Server_Info *);

	/* data offset from read response message */

	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 */

	int (*map_error)(char *, bool);

	/* find mid corresponding to the response message */
@@ -1152,6 +1158,9 @@ struct cifs_readdata { 
				struct cifs_readdata *rdata,

				struct iov_iter *iter);

	struct kvec			iov[2];

#ifdef CONFIG_CIFS_SMB_DIRECT

	struct smbd_mr			*mr;

#endif

	unsigned int			pagesz;

	unsigned int			tailsz;

	unsigned int			credits;

fs/cifs/cifssmb.c

+6 −2
Original line number Diff line number Diff line
@@ -1455,6 +1455,7 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid) 
	struct cifs_readdata *rdata = mid->callback_data;

	char *buf = server->smallbuf;

	unsigned int buflen = get_rfc1002_length(buf) + 4;

	bool use_rdma_mr = false;



	cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n",

		 __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);



	/* how much data is in the response? */

	data_len = server->ops->read_data_length(buf);

	if (data_offset + data_len > buflen) {

#ifdef CONFIG_CIFS_SMB_DIRECT

	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 */

		rdata->result = -EIO;

		return cifs_readv_discard(server, mid);

fs/cifs/smb1ops.c

+3 −1
Original line number Diff line number Diff line
@@ -87,9 +87,11 @@ cifs_read_data_offset(char *buf) 
}



static unsigned int

cifs_read_data_length(char *buf)

cifs_read_data_length(char *buf, bool in_remaining)

{

	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) +

	       le16_to_cpu(rsp->DataLength);

}

fs/cifs/smb2ops.c

+10 −2
Original line number Diff line number Diff line
@@ -957,9 +957,13 @@ smb2_read_data_offset(char *buf) 
}



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;



	if (in_remaining)

		return le32_to_cpu(rsp->DataRemaining);



	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 kvec iov;

	int length;

	bool use_rdma_mr = false;



	if (shdr->Command != SMB2_READ) {

		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_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) {

		/*

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