Commit 947867aa authored by Dominique Martinet's avatar Dominique Martinet Committed by Eric Van Hensbergen
Browse files

9p: trans_fd, read rework to use p9_parse_header 



Most of the changes here are no-op and just renaming to use a
fcall struct, needed for p9_parse_header

It fixes the unaligned memory access to read the tag and defers to
common functions for part of the protocol knowledge (although header
length is still hard-coded...)

Reported-By: default avatarRob Landley <rob@landley.net>
Signed-Off-By: default avatarDominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: default avatarEric Van Hensbergen <ericvh@gmail.com>
parent c7c72c5a

net/9p/trans_fd.c

+40 −35
Original line number Diff line number Diff line
@@ -108,9 +108,7 @@ struct p9_poll_wait { 
 * @unsent_req_list: accounting for requests that haven't been sent

 * @req: current request being processed (if any)

 * @tmp_buf: temporary buffer to read in header

 * @rsize: amount to read for current frame

 * @rpos: read position in current frame

 * @rbuf: current read buffer

 * @rc: temporary fcall for reading current frame

 * @wpos: write position for current frame

 * @wsize: amount of data to write for current frame

 * @wbuf: current write buffer
@@ -131,9 +129,7 @@ struct p9_conn { 
	struct list_head unsent_req_list;

	struct p9_req_t *req;

	char tmp_buf[7];

	int rsize;

	int rpos;

	char *rbuf;

	struct p9_fcall rc;

	int wpos;

	int wsize;

	char *wbuf;
@@ -305,49 +301,56 @@ static void p9_read_work(struct work_struct *work) 
	if (m->err < 0)

		return;



	p9_debug(P9_DEBUG_TRANS, "start mux %p pos %d\n", m, m->rpos);

	p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset);



	if (!m->rbuf) {

		m->rbuf = m->tmp_buf;

		m->rpos = 0;

		m->rsize = 7; /* start by reading header */

	if (!m->rc.sdata) {

		m->rc.sdata = m->tmp_buf;

		m->rc.offset = 0;

		m->rc.capacity = 7; /* start by reading header */

	}



	clear_bit(Rpending, &m->wsched);

	p9_debug(P9_DEBUG_TRANS, "read mux %p pos %d size: %d = %d\n",

		 m, m->rpos, m->rsize, m->rsize-m->rpos);

	err = p9_fd_read(m->client, m->rbuf + m->rpos,

						m->rsize - m->rpos);

	p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n",

		 m, m->rc.offset, m->rc.capacity,

		 m->rc.capacity - m->rc.offset);

	err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset,

			 m->rc.capacity - m->rc.offset);

	p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);

	if (err == -EAGAIN) {

	if (err == -EAGAIN)

		goto end_clear;

	}



	if (err <= 0)

		goto error;



	m->rpos += err;

	m->rc.offset += err;



	if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */

		u16 tag;

	/* header read in */

	if ((!m->req) && (m->rc.offset == m->rc.capacity)) {

		p9_debug(P9_DEBUG_TRANS, "got new header\n");



		n = le32_to_cpu(*(__le32 *) m->rbuf); /* read packet size */

		if (n >= m->client->msize) {

		err = p9_parse_header(&m->rc, NULL, NULL, NULL, 0);

		if (err) {

			p9_debug(P9_DEBUG_ERROR,

				 "error parsing header: %d\n", err);

			goto error;

		}



		if (m->rc.size >= m->client->msize) {

			p9_debug(P9_DEBUG_ERROR,

				 "requested packet size too big: %d\n", n);

				 "requested packet size too big: %d\n",

				 m->rc.size);

			err = -EIO;

			goto error;

		}



		tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */

		p9_debug(P9_DEBUG_TRANS,

			 "mux %p pkt: size: %d bytes tag: %d\n", m, n, tag);

			 "mux %p pkt: size: %d bytes tag: %d\n",

			 m, m->rc.size, m->rc.tag);



		m->req = p9_tag_lookup(m->client, tag);

		m->req = p9_tag_lookup(m->client, m->rc.tag);

		if (!m->req || (m->req->status != REQ_STATUS_SENT)) {

			p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",

				 tag);

				 m->rc.tag);

			err = -EIO;

			goto error;

		}
@@ -361,13 +364,15 @@ static void p9_read_work(struct work_struct *work) 
				goto error;

			}

		}

		m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);

		memcpy(m->rbuf, m->tmp_buf, m->rsize);

		m->rsize = n;

		m->rc.sdata = (char *)m->req->rc + sizeof(struct p9_fcall);

		memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity);

		m->rc.capacity = m->rc.size;

	}



	/* not an else because some packets (like clunk) have no payload */

	if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */

	/* packet is read in

	 * not an else because some packets (like clunk) have no payload

	 */

	if ((m->req) && (m->rc.offset == m->rc.capacity)) {

		p9_debug(P9_DEBUG_TRANS, "got new packet\n");

		spin_lock(&m->client->lock);

		if (m->req->status != REQ_STATUS_ERROR)
@@ -375,9 +380,9 @@ static void p9_read_work(struct work_struct *work) 
		list_del(&m->req->req_list);

		spin_unlock(&m->client->lock);

		p9_client_cb(m->client, m->req, status);

		m->rbuf = NULL;

		m->rpos = 0;

		m->rsize = 0;

		m->rc.sdata = NULL;

		m->rc.offset = 0;

		m->rc.capacity = 0;

		m->req = NULL;

	}

CRA Git | Maintained and supported by SUSTech CRA and CCSE