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Commit c9f2b6ae authored by Al Viro's avatar Al Viro
Browse files

[nbd] pass iov_iter to nbd_xmit() 



... and don't mess with kmap() - just use BVEC_ITER for those parts.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent c1696cab

drivers/block/nbd.c

+27 −39
Original line number Diff line number Diff line
@@ -209,13 +209,12 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req, 
/*

 *  Send or receive packet.

 */

static int sock_xmit(struct nbd_device *nbd, int index, int send, void *buf,

		     int size, int msg_flags)

static int sock_xmit(struct nbd_device *nbd, int index, int send,

		     struct iov_iter *iter, int msg_flags)

{

	struct socket *sock = nbd->socks[index]->sock;

	int result;

	struct msghdr msg;

	struct kvec iov = {.iov_base = buf, .iov_len = size};

	unsigned long pflags = current->flags;



	if (unlikely(!sock)) {
@@ -225,8 +224,7 @@ static int sock_xmit(struct nbd_device *nbd, int index, int send, void *buf, 
		return -EINVAL;

	}



	iov_iter_kvec(&msg.msg_iter, (send ? WRITE : READ) | ITER_KVEC,

		      &iov, 1, size);

	msg.msg_iter = *iter;



	current->flags |= PF_MEMALLOC;

	do {
@@ -254,28 +252,21 @@ static int sock_xmit(struct nbd_device *nbd, int index, int send, void *buf, 
	return result;

}



static inline int sock_send_bvec(struct nbd_device *nbd, int index,

				 struct bio_vec *bvec, int flags)

{

	int result;

	void *kaddr = kmap(bvec->bv_page);

	result = sock_xmit(nbd, index, 1, kaddr + bvec->bv_offset,

			   bvec->bv_len, flags);

	kunmap(bvec->bv_page);

	return result;

}



/* always call with the tx_lock held */

static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)

{

	struct request *req = blk_mq_rq_from_pdu(cmd);

	int result, flags;

	struct nbd_request request;

	struct nbd_request request = {.magic = htonl(NBD_REQUEST_MAGIC)};

	struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)};

	struct iov_iter from;

	unsigned long size = blk_rq_bytes(req);

	struct bio *bio;

	u32 type;

	u32 tag = blk_mq_unique_tag(req);



	iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request));



	if (req_op(req) == REQ_OP_DISCARD)

		type = NBD_CMD_TRIM;

	else if (req_op(req) == REQ_OP_FLUSH)
@@ -285,8 +276,6 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) 
	else

		type = NBD_CMD_READ;



	memset(&request, 0, sizeof(request));

	request.magic = htonl(NBD_REQUEST_MAGIC);

	request.type = htonl(type);

	if (type != NBD_CMD_FLUSH) {

		request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9);
@@ -297,7 +286,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) 
	dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n",

		cmd, nbdcmd_to_ascii(type),

		(unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req));

	result = sock_xmit(nbd, index, 1, &request, sizeof(request),

	result = sock_xmit(nbd, index, 1, &from,

			(type == NBD_CMD_WRITE) ? MSG_MORE : 0);

	if (result <= 0) {

		dev_err_ratelimited(disk_to_dev(nbd->disk),
@@ -322,7 +311,9 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) 
				flags = MSG_MORE;

			dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n",

				cmd, bvec.bv_len);

			result = sock_send_bvec(nbd, index, &bvec, flags);

			iov_iter_bvec(&from, ITER_BVEC | WRITE,

				      &bvec, 1, bvec.bv_len);

			result = sock_xmit(nbd, index, 1, &from, flags);

			if (result <= 0) {

				dev_err(disk_to_dev(nbd->disk),

					"Send data failed (result %d)\n",
@@ -343,17 +334,6 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) 
	return 0;

}



static inline int sock_recv_bvec(struct nbd_device *nbd, int index,

				 struct bio_vec *bvec)

{

	int result;

	void *kaddr = kmap(bvec->bv_page);

	result = sock_xmit(nbd, index, 0, kaddr + bvec->bv_offset,

			   bvec->bv_len, MSG_WAITALL);

	kunmap(bvec->bv_page);

	return result;

}



/* NULL returned = something went wrong, inform userspace */

static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)

{
@@ -363,9 +343,12 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) 
	struct request *req = NULL;

	u16 hwq;

	u32 tag;

	struct kvec iov = {.iov_base = &reply, .iov_len = sizeof(reply)};

	struct iov_iter to;



	reply.magic = 0;

	result = sock_xmit(nbd, index, 0, &reply, sizeof(reply), MSG_WAITALL);

	iov_iter_kvec(&to, READ | ITER_KVEC, &iov, 1, sizeof(reply));

	result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL);

	if (result <= 0) {

		if (!test_bit(NBD_DISCONNECTED, &nbd->runtime_flags) &&

		    !test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags))
@@ -405,7 +388,9 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) 
		struct bio_vec bvec;



		rq_for_each_segment(bvec, req, iter) {

			result = sock_recv_bvec(nbd, index, &bvec);

			iov_iter_bvec(&to, ITER_BVEC | READ,

				      &bvec, 1, bvec.bv_len);

			result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL);

			if (result <= 0) {

				dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n",

					result);
@@ -645,14 +630,17 @@ static void nbd_parse_flags(struct nbd_device *nbd, struct block_device *bdev) 


static void send_disconnects(struct nbd_device *nbd)

{

	struct nbd_request request = {};

	struct nbd_request request = {

		.magic = htonl(NBD_REQUEST_MAGIC),

		.type = htonl(NBD_CMD_DISC),

	};

	struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)};

	struct iov_iter from;

	int i, ret;



	request.magic = htonl(NBD_REQUEST_MAGIC);

	request.type = htonl(NBD_CMD_DISC);



	for (i = 0; i < nbd->num_connections; i++) {

		ret = sock_xmit(nbd, i, 1, &request, sizeof(request), 0);

		iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request));

		ret = sock_xmit(nbd, i, 1, &from, 0);

		if (ret <= 0)

			dev_err(disk_to_dev(nbd->disk),

				"Send disconnect failed %d\n", ret);