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9p: trans_fd, read rework to use p9_parse_header

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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: Rob Landley <rob@landley.net>
Signed-Off-By: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This commit is contained in:
Dominique Martinet 2015-09-03 11:28:20 +02:00 committed by Eric Van Hensbergen
parent c7c72c5a12
commit 947867aa19
1 changed files with 40 additions and 35 deletions
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75
net/9p/trans_fd.c
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@ -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,
"requested packet size too big: %d\n", n);
"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",
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;
}