Release 4.11 net/9p/trans_fd.c
/*
* linux/fs/9p/trans_fd.c
*
* Fd transport layer. Includes deprecated socket layer.
*
* Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
* Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
* Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to:
* Free Software Foundation
* 51 Franklin Street, Fifth Floor
* Boston, MA 02111-1301 USA
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/in.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/ipv6.h>
#include <linux/kthread.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/un.h>
#include <linux/uaccess.h>
#include <linux/inet.h>
#include <linux/idr.h>
#include <linux/file.h>
#include <linux/parser.h>
#include <linux/slab.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include <net/9p/transport.h>
#include <linux/syscalls.h> /* killme */
#define P9_PORT 564
#define MAX_SOCK_BUF (64*1024)
#define MAXPOLLWADDR 2
/**
* struct p9_fd_opts - per-transport options
* @rfd: file descriptor for reading (trans=fd)
* @wfd: file descriptor for writing (trans=fd)
* @port: port to connect to (trans=tcp)
*
*/
struct p9_fd_opts {
int rfd;
int wfd;
u16 port;
int privport;
};
/*
* Option Parsing (code inspired by NFS code)
* - a little lazy - parse all fd-transport options
*/
enum {
/* Options that take integer arguments */
Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
/* Options that take no arguments */
Opt_privport,
};
static const match_table_t tokens = {
{Opt_port, "port=%u"},
{Opt_rfdno, "rfdno=%u"},
{Opt_wfdno, "wfdno=%u"},
{Opt_privport, "privport"},
{Opt_err, NULL},
};
enum {
Rworksched = 1, /* read work scheduled or running */
Rpending = 2, /* can read */
Wworksched = 4, /* write work scheduled or running */
Wpending = 8, /* can write */
};
struct p9_poll_wait {
struct p9_conn *conn;
wait_queue_t wait;
wait_queue_head_t *wait_addr;
};
/**
* struct p9_conn - fd mux connection state information
* @mux_list: list link for mux to manage multiple connections (?)
* @client: reference to client instance for this connection
* @err: error state
* @req_list: accounting for requests which have been sent
* @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
* @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
* @poll_pending_link: pending links to be polled per conn
* @poll_wait: array of wait_q's for various worker threads
* @pt: poll state
* @rq: current read work
* @wq: current write work
* @wsched: ????
*
*/
struct p9_conn {
struct list_head mux_list;
struct p9_client *client;
int err;
struct list_head req_list;
struct list_head unsent_req_list;
struct p9_req_t *req;
char tmp_buf[7];
struct p9_fcall rc;
int wpos;
int wsize;
char *wbuf;
struct list_head poll_pending_link;
struct p9_poll_wait poll_wait[MAXPOLLWADDR];
poll_table pt;
struct work_struct rq;
struct work_struct wq;
unsigned long wsched;
};
/**
* struct p9_trans_fd - transport state
* @rd: reference to file to read from
* @wr: reference of file to write to
* @conn: connection state reference
*
*/
struct p9_trans_fd {
struct file *rd;
struct file *wr;
struct p9_conn conn;
};
static void p9_poll_workfn(struct work_struct *work);
static DEFINE_SPINLOCK(p9_poll_lock);
static LIST_HEAD(p9_poll_pending_list);
static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
static unsigned int p9_ipport_resv_min = P9_DEF_MIN_RESVPORT;
static unsigned int p9_ipport_resv_max = P9_DEF_MAX_RESVPORT;
static void p9_mux_poll_stop(struct p9_conn *m)
{
unsigned long flags;
int i;
for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
struct p9_poll_wait *pwait = &m->poll_wait[i];
if (pwait->wait_addr) {
remove_wait_queue(pwait->wait_addr, &pwait->wait);
pwait->wait_addr = NULL;
}
}
spin_lock_irqsave(&p9_poll_lock, flags);
list_del_init(&m->poll_pending_link);
spin_unlock_irqrestore(&p9_poll_lock, flags);
}
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Total | 101 | 100.00% | 2 | 100.00% |
/**
* p9_conn_cancel - cancel all pending requests with error
* @m: mux data
* @err: error code
*
*/
static void p9_conn_cancel(struct p9_conn *m, int err)
{
struct p9_req_t *req, *rtmp;
unsigned long flags;
LIST_HEAD(cancel_list);
p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
spin_lock_irqsave(&m->client->lock, flags);
if (m->err) {
spin_unlock_irqrestore(&m->client->lock, flags);
return;
}
m->err = err;
list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
list_move(&req->req_list, &cancel_list);
}
list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
list_move(&req->req_list, &cancel_list);
}
spin_unlock_irqrestore(&m->client->lock, flags);
list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
list_del(&req->req_list);
if (!req->t_err)
req->t_err = err;
p9_client_cb(m->client, req, REQ_STATUS_ERROR);
}
}
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Eric Van Hensbergen | 167 | 86.98% | 5 | 62.50% |
Dominique Martinet | 15 | 7.81% | 1 | 12.50% |
Latchesar Ionkov | 8 | 4.17% | 1 | 12.50% |
Joe Perches | 2 | 1.04% | 1 | 12.50% |
Total | 192 | 100.00% | 8 | 100.00% |
static int
p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
{
int ret, n;
struct p9_trans_fd *ts = NULL;
if (client && client->status == Connected)
ts = client->trans;
if (!ts)
return -EREMOTEIO;
if (!ts->rd->f_op->poll)
return -EIO;
if (!ts->wr->f_op->poll)
return -EIO;
ret = ts->rd->f_op->poll(ts->rd, pt);
if (ret < 0)
return ret;
if (ts->rd != ts->wr) {
n = ts->wr->f_op->poll(ts->wr, pt);
if (n < 0)
return n;
ret = (ret & ~POLLOUT) | (n & ~POLLIN);
}
return ret;
}
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Eric Van Hensbergen | 150 | 90.36% | 4 | 80.00% |
Tejun Heo | 16 | 9.64% | 1 | 20.00% |
Total | 166 | 100.00% | 5 | 100.00% |
/**
* p9_fd_read- read from a fd
* @client: client instance
* @v: buffer to receive data into
* @len: size of receive buffer
*
*/
static int p9_fd_read(struct p9_client *client, void *v, int len)
{
int ret;
struct p9_trans_fd *ts = NULL;
if (client && client->status != Disconnected)
ts = client->trans;
if (!ts)
return -EREMOTEIO;
if (!(ts->rd->f_flags & O_NONBLOCK))
p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
client->status = Disconnected;
return ret;
}
Contributors
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Eric Van Hensbergen | 105 | 89.74% | 2 | 50.00% |
Tejun Heo | 11 | 9.40% | 1 | 25.00% |
Joe Perches | 1 | 0.85% | 1 | 25.00% |
Total | 117 | 100.00% | 4 | 100.00% |
/**
* p9_read_work - called when there is some data to be read from a transport
* @work: container of work to be done
*
*/
static void p9_read_work(struct work_struct *work)
{
int n, err;
struct p9_conn *m;
int status = REQ_STATUS_ERROR;
m = container_of(work, struct p9_conn, rq);
if (m->err < 0)
return;
p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset);
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 %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)
goto end_clear;
if (err <= 0)
goto error;
m->rc.offset += err;
/* header read in */
if ((!m->req) && (m->rc.offset == m->rc.capacity)) {
p9_debug(P9_DEBUG_TRANS, "got new header\n");
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",
m->rc.size);
err = -EIO;
goto error;
}
p9_debug(P9_DEBUG_TRANS,
"mux %p pkt: size: %d bytes tag: %d\n",
m, m->rc.size, m->rc.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",
m->rc.tag);
err = -EIO;
goto error;
}
if (m->req->rc == NULL) {
p9_debug(P9_DEBUG_ERROR,
"No recv fcall for tag %d (req %p), disconnecting!\n",
m->rc.tag, m->req);
m->req = NULL;
err = -EIO;
goto error;
}
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;
}
/* 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)
status = REQ_STATUS_RCVD;
list_del(&m->req->req_list);
spin_unlock(&m->client->lock);
p9_client_cb(m->client, m->req, status);
m->rc.sdata = NULL;
m->rc.offset = 0;
m->rc.capacity = 0;
m->req = NULL;
}
end_clear:
clear_bit(Rworksched, &m->wsched);
if (!list_empty(&m->req_list)) {
if (test_and_clear_bit(Rpending, &m->wsched))
n = POLLIN;
else
n = p9_fd_poll(m->client, NULL);
if ((n & POLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) {
p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
schedule_work(&m->rq);
}
}
return;
error:
p9_conn_cancel(m, err);
clear_bit(Rworksched, &m->wsched);
}
Contributors
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Eric Van Hensbergen | 487 | 67.27% | 7 | 46.67% |
Dominique Martinet | 159 | 21.96% | 3 | 20.00% |
Simon Derr | 28 | 3.87% | 1 | 6.67% |
Latchesar Ionkov | 24 | 3.31% | 1 | 6.67% |
Tejun Heo | 17 | 2.35% | 2 | 13.33% |
Joe Perches | 9 | 1.24% | 1 | 6.67% |
Total | 724 | 100.00% | 15 | 100.00% |
/**
* p9_fd_write - write to a socket
* @client: client instance
* @v: buffer to send data from
* @len: size of send buffer
*
*/
static int p9_fd_write(struct p9_client *client, void *v, int len)
{
int ret;
mm_segment_t oldfs;
struct p9_trans_fd *ts = NULL;
if (client && client->status != Disconnected)
ts = client->trans;
if (!ts)
return -EREMOTEIO;
if (!(ts->wr->f_flags & O_NONBLOCK))
p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
oldfs = get_fs();
set_fs(get_ds());
/* The cast to a user pointer is valid due to the set_fs() */
ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos);
set_fs(oldfs);
if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
client->status = Disconnected;
return ret;
}
Contributors
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Eric Van Hensbergen | 142 | 98.61% | 3 | 60.00% |
Joe Perches | 1 | 0.69% | 1 | 20.00% |
Hannes Eder | 1 | 0.69% | 1 | 20.00% |
Total | 144 | 100.00% | 5 | 100.00% |
/**
* p9_write_work - called when a transport can send some data
* @work: container for work to be done
*
*/
static void p9_write_work(struct work_struct *work)
{
int n, err;
struct p9_conn *m;
struct p9_req_t *req;
m = container_of(work, struct p9_conn, wq);
if (m->err < 0) {
clear_bit(Wworksched, &m->wsched);
return;
}
if (!m->wsize) {
spin_lock(&m->client->lock);
if (list_empty(&m->unsent_req_list)) {
clear_bit(Wworksched, &m->wsched);
spin_unlock(&m->client->lock);
return;
}
req = list_entry(m->unsent_req_list.next, struct p9_req_t,
req_list);
req->status = REQ_STATUS_SENT;
p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
list_move_tail(&req->req_list, &m->req_list);
m->wbuf = req->tc->sdata;
m->wsize = req->tc->size;
m->wpos = 0;
spin_unlock(&m->client->lock);
}
p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n",
m, m->wpos, m->wsize);
clear_bit(Wpending, &m->wsched);
err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
if (err == -EAGAIN)
goto end_clear;
if (err < 0)
goto error;
else if (err == 0) {
err = -EREMOTEIO;
goto error;
}
m->wpos += err;
if (m->wpos == m->wsize)
m->wpos = m->wsize = 0;
end_clear:
clear_bit(Wworksched, &m->wsched);
if (m->wsize || !list_empty(&m->unsent_req_list)) {
if (test_and_clear_bit(Wpending, &m->wsched))
n = POLLOUT;
else
n = p9_fd_poll(m->client, NULL);
if ((n & POLLOUT) &&
!test_and_set_bit(Wworksched, &m->wsched)) {
p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
schedule_work(&m->wq);
}
}
return;
error:
p9_conn_cancel(m, err);
clear_bit(Wworksched, &m->wsched);
}
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Latchesar Ionkov | 8 | 1.86% | 1 | 9.09% |
Joe Perches | 4 | 0.93% | 1 | 9.09% |
Tejun Heo | 1 | 0.23% | 1 | 9.09% |
Total | 431 | 100.00% | 11 | 100.00% |
static int p9_pollwake(wait_queue_t *wait, unsigned int mode, int sync, void *key)
{
struct p9_poll_wait *pwait =
container_of(wait, struct p9_poll_wait, wait);
struct p9_conn *m = pwait->conn;
unsigned long flags;
spin_lock_irqsave(&p9_poll_lock, flags);
if (list_empty(&m->poll_pending_link))
list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
spin_unlock_irqrestore(&p9_poll_lock, flags);
schedule_work(&p9_poll_work);
return 1;
}
Contributors
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Eric Van Hensbergen | 89 | 93.68% | 2 | 50.00% |
Tejun Heo | 5 | 5.26% | 1 | 25.00% |
Eric Dumazet | 1 | 1.05% | 1 | 25.00% |
Total | 95 | 100.00% | 4 | 100.00% |
/**
* p9_pollwait - add poll task to the wait queue
* @filp: file pointer being polled
* @wait_address: wait_q to block on
* @p: poll state
*
* called by files poll operation to add v9fs-poll task to files wait queue
*/
static void
p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
{
struct p9_conn *m = container_of(p, struct p9_conn, pt);
struct p9_poll_wait *pwait = NULL;
int i;
for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
if (m->poll_wait[i].wait_addr == NULL) {
pwait = &m->poll_wait[i];
break;
}
}
if (!pwait) {
p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n");
return;
}
pwait->conn = m;
pwait->wait_addr = wait_address;
init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
add_wait_queue(wait_address, &pwait->wait);
}
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Eric Van Hensbergen | 136 | 99.27% | 2 | 66.67% |
Joe Perches | 1 | 0.73% | 1 | 33.33% |
Total | 137 | 100.00% | 3 | 100.00% |
/**
* p9_conn_create - initialize the per-session mux data
* @client: client instance
*
* Note: Creates the polling task if this is the first session.
*/
static void p9_conn_create(struct p9_client *client)
{
int n;
struct p9_trans_fd *ts = client->trans;
struct p9_conn *m = &ts->conn;
p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
INIT_LIST_HEAD(&m->mux_list);
m->client = client;
INIT_LIST_HEAD(&m->req_list);
INIT_LIST_HEAD(&m->unsent_req_list);
INIT_WORK(&m->rq, p9_read_work);
INIT_WORK(&m->wq, p9_write_work);
INIT_LIST_HEAD(&m->poll_pending_link);
init_poll_funcptr(&m->pt, p9_pollwait);
n = p9_fd_poll(client, &m->pt);
if (n & POLLIN) {
p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
set_bit(Rpending, &m->wsched);
}
if (n & POLLOUT) {
p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
set_bit(Wpending, &m->wsched);
}
}
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Eric Van Hensbergen | 162 | 90.00% | 3 | 60.00% |
Simon Derr | 15 | 8.33% | 1 | 20.00% |
Joe Perches | 3 | 1.67% | 1 | 20.00% |
Total | 180 | 100.00% | 5 | 100.00% |
/**
* p9_poll_mux - polls a mux and schedules read or write works if necessary
* @m: connection to poll
*
*/
static void p9_poll_mux(struct p9_conn *m)
{
int n;
if (m->err < 0)
return;
n = p9_fd_poll(m->client, NULL);
if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
if (n >= 0)
n = -ECONNRESET;
p9_conn_cancel(m, n);
}
if (n & POLLIN) {
set_bit(Rpending, &m->wsched);
p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
if (!test_and_set_bit(Rworksched, &m->wsched)) {
p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
schedule_work(&m->rq);
}
}
if (n & POLLOUT) {
set_bit(Wpending, &m->wsched);
p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
!test_and_set_bit(Wworksched, &m->wsched)) {
p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
schedule_work(&m->wq);
}
}
}
Contributors
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Eric Van Hensbergen | 207 | 96.73% | 3 | 60.00% |
Joe Perches | 5 | 2.34% | 1 | 20.00% |
Tejun Heo | 2 | 0.93% | 1 | 20.00% |
Total | 214 | 100.00% | 5 | 100.00% |
/**
* p9_fd_request - send 9P request
* The function can sleep until the request is scheduled for sending.
* The function can be interrupted. Return from the function is not
* a guarantee that the request is sent successfully.
*
* @client: client instance
* @req: request to be sent
*
*/
static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
{
int n;
struct p9_trans_fd *ts = client->trans;
struct p9_conn *m = &ts->conn;
p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
m, current, req->tc, req->tc->id);
if (m->err < 0)
return m->err;
spin_lock(&client->lock);
req->status = REQ_STATUS_UNSENT;
list_add_tail(&req->req_list, &m->unsent_req_list);
spin_unlock(&client->lock);
if (test_and_clear_bit(Wpending, &m->wsched))
n = POLLOUT;
else
n = p9_fd_poll(m->client, NULL);
if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
schedule_work(&m->wq);
return 0;
}
Contributors
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Eric Van Hensbergen | 150 | 92.02% | 9 | 69.23% |
Latchesar Ionkov | 10 | 6.13% | 1 | 7.69% |
Simon Derr | 1 | 0.61% | 1 | 7.69% |
Joe Perches | 1 | 0.61% | 1 | 7.69% |
Tejun Heo | 1 | 0.61% | 1 | 7.69% |
Total | 163 | 100.00% | 13 | 100.00% |
static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
{
int ret = 1;
p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
spin_lock(&client->lock);
if (req->