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Commit b8f57ee8 authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Separate RFC1001 length processing for SMB2 read 



Allocate and initialize SMB2 read request without RFC1001 length
field to directly call cifs_send_recv() rather than SendReceive2()
in a read codepath.

Signed-off-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
parent cb200bd6

fs/cifs/cifsproto.h

+3 −0
Original line number Diff line number Diff line
@@ -79,6 +79,9 @@ extern int cifs_call_async(struct TCP_Server_Info *server, 
			struct smb_rqst *rqst,

			mid_receive_t *receive, mid_callback_t *callback,

			void *cbdata, const int flags);

extern int cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,

			  struct smb_rqst *rqst, int *resp_buf_type,

			  const int flags, struct kvec *resp_iov);

extern int SendReceive(const unsigned int /* xid */ , struct cifs_ses *,

			struct smb_hdr * /* input */ ,

			struct smb_hdr * /* out */ ,

fs/cifs/smb2pdu.c

+67 −22
Original line number Diff line number Diff line
@@ -293,10 +293,46 @@ fill_small_buf(__le16 smb2_command, struct cifs_tcon *tcon, void *buf, 
	*total_len = parmsize + sizeof(struct smb2_sync_hdr);

}



/* init request without RFC1001 length at the beginning */

static int

smb2_plain_req_init(__le16 smb2_command, struct cifs_tcon *tcon,

		    void **request_buf, unsigned int *total_len)

{

	int rc;

	struct smb2_sync_hdr *shdr;



	rc = smb2_reconnect(smb2_command, tcon);

	if (rc)

		return rc;



	/* BB eventually switch this to SMB2 specific small buf size */

	*request_buf = cifs_small_buf_get();

	if (*request_buf == NULL) {

		/* BB should we add a retry in here if not a writepage? */

		return -ENOMEM;

	}



	shdr = (struct smb2_sync_hdr *)(*request_buf);



	fill_small_buf(smb2_command, tcon, shdr, total_len);



	if (tcon != NULL) {

#ifdef CONFIG_CIFS_STATS2

		uint16_t com_code = le16_to_cpu(smb2_command);



		cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_sent[com_code]);

#endif

		cifs_stats_inc(&tcon->num_smbs_sent);

	}



	return rc;

}



/*

 * Allocate and return pointer to an SMB request hdr, and set basic

 * SMB information in the SMB header. If the return code is zero, this

 * function must have filled in request_buf pointer.

 * function must have filled in request_buf pointer. The returned buffer

 * has RFC1001 length at the beginning.

 */

static int

small_smb2_init(__le16 smb2_command, struct cifs_tcon *tcon,
@@ -2140,16 +2176,17 @@ smb2_new_read_req(void **buf, unsigned int *total_len, 
		  int request_type)

{

	int rc = -EACCES;

	struct smb2_read_req *req = NULL;

	struct smb2_read_plain_req *req = NULL;

	struct smb2_sync_hdr *shdr;



	rc = small_smb2_init(SMB2_READ, io_parms->tcon, (void **) &req);

	rc = smb2_plain_req_init(SMB2_READ, io_parms->tcon, (void **) &req,

				 total_len);

	if (rc)

		return rc;

	if (io_parms->tcon->ses->server == NULL)

		return -ECONNABORTED;



	shdr = get_sync_hdr(req);

	shdr = &req->sync_hdr;

	shdr->ProcessId = cpu_to_le32(io_parms->pid);



	req->PersistentFileId = io_parms->persistent_fid;
@@ -2163,9 +2200,9 @@ smb2_new_read_req(void **buf, unsigned int *total_len, 


	if (request_type & CHAINED_REQUEST) {

		if (!(request_type & END_OF_CHAIN)) {

			/* 4 for rfc1002 length field */

			shdr->NextCommand =

				cpu_to_le32(get_rfc1002_length(req) + 4);

			/* next 8-byte aligned request */

			*total_len = DIV_ROUND_UP(*total_len, 8) * 8;

			shdr->NextCommand = cpu_to_le32(*total_len);

		} else /* END_OF_CHAIN */

			shdr->NextCommand = 0;

		if (request_type & RELATED_REQUEST) {
@@ -2186,8 +2223,6 @@ smb2_new_read_req(void **buf, unsigned int *total_len, 
		req->RemainingBytes = 0;



	*buf = req;

	/* 4 for rfc1002 length field */

	*total_len = get_rfc1002_length(req) + 4;

	return rc;

}
@@ -2264,6 +2299,7 @@ smb2_async_readv(struct cifs_readdata *rdata) 
				 .rq_nvec = 2 };

	struct TCP_Server_Info *server;

	unsigned int total_len;

	__be32 req_len;



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

		 __func__, rdata->offset, rdata->bytes);
@@ -2290,12 +2326,14 @@ smb2_async_readv(struct cifs_readdata *rdata) 
		return rc;

	}



	shdr = get_sync_hdr(buf);

	/* 4 for rfc1002 length field */

	rdata->iov[0].iov_len = 4;

	rdata->iov[0].iov_base = buf;

	rdata->iov[1].iov_len = total_len - 4;

	rdata->iov[1].iov_base = buf + 4;

	req_len = cpu_to_be32(total_len);



	rdata->iov[0].iov_base = &req_len;

	rdata->iov[0].iov_len = sizeof(__be32);

	rdata->iov[1].iov_base = buf;

	rdata->iov[1].iov_len = total_len;



	shdr = (struct smb2_sync_hdr *)buf;



	if (rdata->credits) {

		shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(rdata->bytes,
@@ -2327,24 +2365,31 @@ SMB2_read(const unsigned int xid, struct cifs_io_parms *io_parms, 
	  unsigned int *nbytes, char **buf, int *buf_type)

{

	int resp_buftype, rc = -EACCES;

	struct smb2_read_plain_req *req = NULL;

	struct smb2_read_rsp *rsp = NULL;

	struct smb2_sync_hdr *shdr;

	struct kvec iov[1];

	struct kvec iov[2];

	struct kvec rsp_iov;

	unsigned int total_len;

	char *req;

	__be32 req_len;

	struct smb_rqst rqst = { .rq_iov = iov,

				 .rq_nvec = 2 };



	*nbytes = 0;

	rc = smb2_new_read_req((void **)&req, &total_len, io_parms, 0, 0);

	if (rc)

		return rc;



	iov[0].iov_base = buf;

	iov[0].iov_len = total_len;

	req_len = cpu_to_be32(total_len);



	rc = SendReceive2(xid, io_parms->tcon->ses, iov, 1,

			  &resp_buftype, CIFS_LOG_ERROR, &rsp_iov);

	cifs_small_buf_release(iov[0].iov_base);

	iov[0].iov_base = &req_len;

	iov[0].iov_len = sizeof(__be32);

	iov[1].iov_base = req;

	iov[1].iov_len = total_len;



	rc = cifs_send_recv(xid, io_parms->tcon->ses, &rqst, &resp_buftype,

			    CIFS_LOG_ERROR, &rsp_iov);

	cifs_small_buf_release(req);



	rsp = (struct smb2_read_rsp *)rsp_iov.iov_base;

	shdr = get_sync_hdr(rsp);

fs/cifs/smb2pdu.h

+3 −2
Original line number Diff line number Diff line
@@ -823,8 +823,9 @@ struct smb2_flush_rsp { 
#define SMB2_CHANNEL_RDMA_V1		0x00000001 /* SMB3 or later */

#define SMB2_CHANNEL_RDMA_V1_INVALIDATE 0x00000001 /* SMB3.02 or later */



struct smb2_read_req {

	struct smb2_hdr hdr;

/* SMB2 read request without RFC1001 length at the beginning */

struct smb2_read_plain_req {

	struct smb2_sync_hdr sync_hdr;

	__le16 StructureSize; /* Must be 49 */

	__u8   Padding; /* offset from start of SMB2 header to place read */

	__u8   Flags; /* MBZ unless SMB3.02 or later */

fs/cifs/transport.c

+1 −1
Original line number Diff line number Diff line
@@ -666,7 +666,7 @@ cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst) 
	return mid;

}



static int

int

cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,

	       struct smb_rqst *rqst, int *resp_buf_type, const int flags,

	       struct kvec *resp_iov)