linux/net/9p/trans_fd.c

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/*
* 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
*
*/
#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 <net/9p/9p.h>
#include <net/9p/client.h>
#include <net/9p/transport.h>
#define P9_PORT 564
#define MAX_SOCK_BUF (64*1024)
#define ERREQFLUSH 1
#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;
};
/**
* 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;
};
/*
* 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,
};
static const match_table_t tokens = {
{Opt_port, "port=%u"},
{Opt_rfdno, "rfdno=%u"},
{Opt_wfdno, "wfdno=%u"},
{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 */
};
enum {
None,
Flushing,
Flushed,
};
struct p9_req;
typedef void (*p9_conn_req_callback)(struct p9_req *req, void *a);
/**
* struct p9_req - fd mux encoding of an rpc transaction
* @lock: protects req_list
* @tag: numeric tag for rpc transaction
* @tcall: request &p9_fcall structure
* @rcall: response &p9_fcall structure
* @err: error state
* @cb: callback for when response is received
* @cba: argument to pass to callback
* @flush: flag to indicate RPC has been flushed
* @req_list: list link for higher level objects to chain requests
*
*/
struct p9_req {
spinlock_t lock;
int tag;
struct p9_fcall *tcall;
struct p9_fcall *rcall;
int err;
p9_conn_req_callback cb;
void *cba;
int flush;
struct list_head req_list;
};
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
* @lock: protects mux_list (?)
* @mux_list: list link for mux to manage multiple connections (?)
* @client: reference to client instance for this connection
* @tagpool: id accounting for transactions
* @err: error state
* @req_list: accounting for requests which have been sent
* @unsent_req_list: accounting for requests that haven't been sent
* @rcall: current response &p9_fcall structure
* @rpos: read position in current frame
* @rbuf: current read buffer
* @wpos: write position for current frame
* @wsize: amount of data to write for current frame
* @wbuf: current write buffer
* @poll_wait: array of wait_q's for various worker threads
* @poll_waddr: ????
* @pt: poll state
* @rq: current read work
* @wq: current write work
* @wsched: ????
*
*/
struct p9_conn {
spinlock_t lock; /* protect lock structure */
struct list_head mux_list;
struct p9_client *client;
struct p9_idpool *tagpool;
int err;
struct list_head req_list;
struct list_head unsent_req_list;
struct p9_fcall *rcall;
int rpos;
char *rbuf;
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_mux_rpc - fd mux rpc accounting structure
* @m: connection this request was issued on
* @err: error state
* @tcall: request &p9_fcall
* @rcall: response &p9_fcall
* @wqueue: wait queue that client is blocked on for this rpc
*
* Bug: isn't this information duplicated elsewhere like &p9_req
*/
struct p9_mux_rpc {
struct p9_conn *m;
int err;
struct p9_fcall *tcall;
struct p9_fcall *rcall;
wait_queue_head_t wqueue;
};
static int p9_poll_proc(void *);
static void p9_read_work(struct work_struct *work);
static void p9_write_work(struct work_struct *work);
static void p9_pollwait(struct file *filp, wait_queue_head_t *wait_address,
poll_table *p);
static int p9_fd_write(struct p9_client *client, void *v, int len);
static int p9_fd_read(struct p9_client *client, void *v, int len);
static DEFINE_SPINLOCK(p9_poll_lock);
static LIST_HEAD(p9_poll_pending_list);
static struct workqueue_struct *p9_mux_wq;
static struct task_struct *p9_poll_task;
static void p9_conn_destroy(struct p9_conn *);
static unsigned int p9_fd_poll(struct p9_client *client,
struct poll_table_struct *pt);
#ifdef P9_NONBLOCK
static int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
p9_conn_req_callback cb, void *a);
#endif /* P9_NONBLOCK */
static void p9_conn_cancel(struct p9_conn *m, int err);
static u16 p9_mux_get_tag(struct p9_conn *m)
{
int tag;
tag = p9_idpool_get(m->tagpool);
if (tag < 0)
return P9_NOTAG;
else
return (u16) tag;
}
static void p9_mux_put_tag(struct p9_conn *m, u16 tag)
{
if (tag != P9_NOTAG && p9_idpool_check(tag, m->tagpool))
p9_idpool_put(tag, m->tagpool);
}
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);
}
/**
* p9_conn_create - allocate and initialize the per-session mux data
* @client: client instance
*
* Note: Creates the polling task if this is the first session.
*/
static struct p9_conn *p9_conn_create(struct p9_client *client)
{
int i, n;
struct p9_conn *m;
P9_DPRINTK(P9_DEBUG_MUX, "client %p msize %d\n", client, client->msize);
m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
if (!m)
return ERR_PTR(-ENOMEM);
spin_lock_init(&m->lock);
INIT_LIST_HEAD(&m->mux_list);
m->client = client;
m->tagpool = p9_idpool_create();
if (IS_ERR(m->tagpool)) {
kfree(m);
return ERR_PTR(-ENOMEM);
}
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_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
set_bit(Rpending, &m->wsched);
}
if (n & POLLOUT) {
P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
set_bit(Wpending, &m->wsched);
}
for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
if (IS_ERR(m->poll_wait[i].wait_addr)) {
p9_mux_poll_stop(m);
kfree(m);
/* return the error code */
return (void *)m->poll_wait[i].wait_addr;
}
}
return m;
}
/**
* p9_mux_destroy - cancels all pending requests and frees mux resources
* @m: mux to destroy
*
*/
static void p9_conn_destroy(struct p9_conn *m)
{
P9_DPRINTK(P9_DEBUG_MUX, "mux %p prev %p next %p\n", m,
m->mux_list.prev, m->mux_list.next);
p9_mux_poll_stop(m);
cancel_work_sync(&m->rq);
cancel_work_sync(&m->wq);
p9_conn_cancel(m, -ECONNRESET);
m->client = NULL;
p9_idpool_destroy(m->tagpool);
kfree(m);
}
static int p9_pollwake(wait_queue_t *wait, unsigned 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;
DECLARE_WAITQUEUE(dummy_wait, p9_poll_task);
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);
/* perform the default wake up operation */
return default_wake_function(&dummy_wait, mode, sync, key);
}
/**
* 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_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
return;
}
if (!wait_address) {
P9_DPRINTK(P9_DEBUG_ERROR, "no wait_address\n");
pwait->wait_addr = ERR_PTR(-EIO);
return;
}
pwait->conn = m;
pwait->wait_addr = wait_address;
init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
add_wait_queue(wait_address, &pwait->wait);
}
/**
* 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_DPRINTK(P9_DEBUG_MUX, "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_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
if (!test_and_set_bit(Rworksched, &m->wsched)) {
P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
queue_work(p9_mux_wq, &m->rq);
}
}
if (n & POLLOUT) {
set_bit(Wpending, &m->wsched);
P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
if ((m->wsize || !list_empty(&m->unsent_req_list))
&& !test_and_set_bit(Wworksched, &m->wsched)) {
P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
queue_work(p9_mux_wq, &m->wq);
}
}
}
/**
* p9_poll_proc - poll worker thread
* @a: thread state and arguments
*
* polls all v9fs transports for new events and queues the appropriate
* work to the work queue
*
*/
static int p9_poll_proc(void *a)
{
unsigned long flags;
P9_DPRINTK(P9_DEBUG_MUX, "start %p\n", current);
repeat:
spin_lock_irqsave(&p9_poll_lock, flags);
while (!list_empty(&p9_poll_pending_list)) {
struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
struct p9_conn,
poll_pending_link);
list_del_init(&conn->poll_pending_link);
spin_unlock_irqrestore(&p9_poll_lock, flags);
p9_poll_mux(conn);
spin_lock_irqsave(&p9_poll_lock, flags);
}
spin_unlock_irqrestore(&p9_poll_lock, flags);
set_current_state(TASK_INTERRUPTIBLE);
if (list_empty(&p9_poll_pending_list)) {
P9_DPRINTK(P9_DEBUG_MUX, "sleeping...\n");
schedule();
}
__set_current_state(TASK_RUNNING);
if (!kthread_should_stop())
goto repeat;
P9_DPRINTK(P9_DEBUG_MUX, "finish\n");
return 0;
}
/**
* 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 *req;
m = container_of(work, struct p9_conn, wq);
if (m->err < 0) {
clear_bit(Wworksched, &m->wsched);
return;
}
if (!m->wsize) {
if (list_empty(&m->unsent_req_list)) {
clear_bit(Wworksched, &m->wsched);
return;
}
spin_lock(&m->lock);
again:
req = list_entry(m->unsent_req_list.next, struct p9_req,
req_list);
list_move_tail(&req->req_list, &m->req_list);
if (req->err == ERREQFLUSH)
goto again;
m->wbuf = req->tcall->sdata;
m->wsize = req->tcall->size;
m->wpos = 0;
spin_unlock(&m->lock);
}
P9_DPRINTK(P9_DEBUG_MUX, "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_DPRINTK(P9_DEBUG_MUX, "mux %p sent %d bytes\n", m, err);
if (err == -EAGAIN) {
clear_bit(Wworksched, &m->wsched);
return;
}
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;
if (m->wsize == 0 && !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) {
P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
queue_work(p9_mux_wq, &m->wq);
} else
clear_bit(Wworksched, &m->wsched);
} else
clear_bit(Wworksched, &m->wsched);
return;
error:
p9_conn_cancel(m, err);
clear_bit(Wworksched, &m->wsched);
}
static void process_request(struct p9_conn *m, struct p9_req *req)
{
int ecode;
struct p9_str *ename;
if (!req->err && req->rcall->id == P9_RERROR) {
ecode = req->rcall->params.rerror.errno;
ename = &req->rcall->params.rerror.error;
P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
ename->str);
if (m->client->dotu)
req->err = -ecode;
if (!req->err) {
req->err = p9_errstr2errno(ename->str, ename->len);
/* string match failed */
if (!req->err) {
PRINT_FCALL_ERROR("unknown error", req->rcall);
req->err = -ESERVERFAULT;
}
}
} else if (req->tcall && req->rcall->id != req->tcall->id + 1) {
P9_DPRINTK(P9_DEBUG_ERROR,
"fcall mismatch: expected %d, got %d\n",
req->tcall->id + 1, req->rcall->id);
if (!req->err)
req->err = -EIO;
}
}
/**
* 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;
struct p9_req *req, *rptr, *rreq;
struct p9_fcall *rcall;
char *rbuf;
m = container_of(work, struct p9_conn, rq);
if (m->err < 0)
return;
rcall = NULL;
P9_DPRINTK(P9_DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos);
if (!m->rcall) {
m->rcall =
kmalloc(sizeof(struct p9_fcall) + m->client->msize,
GFP_KERNEL);
if (!m->rcall) {
err = -ENOMEM;
goto error;
}
m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
m->rpos = 0;
}
clear_bit(Rpending, &m->wsched);
err = p9_fd_read(m->client, m->rbuf + m->rpos,
m->client->msize - m->rpos);
P9_DPRINTK(P9_DEBUG_MUX, "mux %p got %d bytes\n", m, err);
if (err == -EAGAIN) {
clear_bit(Rworksched, &m->wsched);
return;
}
if (err <= 0)
goto error;
m->rpos += err;
while (m->rpos > 4) {
n = le32_to_cpu(*(__le32 *) m->rbuf);
if (n >= m->client->msize) {
P9_DPRINTK(P9_DEBUG_ERROR,
"requested packet size too big: %d\n", n);
err = -EIO;
goto error;
}
if (m->rpos < n)
break;
err =
p9_deserialize_fcall(m->rbuf, n, m->rcall, m->client->dotu);
if (err < 0)
goto error;
#ifdef CONFIG_NET_9P_DEBUG
if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
char buf[150];
p9_printfcall(buf, sizeof(buf), m->rcall,
m->client->dotu);
printk(KERN_NOTICE ">>> %p %s\n", m, buf);
}
#endif
rcall = m->rcall;
rbuf = m->rbuf;
if (m->rpos > n) {
m->rcall = kmalloc(sizeof(struct p9_fcall) +
m->client->msize, GFP_KERNEL);
if (!m->rcall) {
err = -ENOMEM;
goto error;
}
m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
memmove(m->rbuf, rbuf + n, m->rpos - n);
m->rpos -= n;
} else {
m->rcall = NULL;
m->rbuf = NULL;
m->rpos = 0;
}
P9_DPRINTK(P9_DEBUG_MUX, "mux %p fcall id %d tag %d\n", m,
rcall->id, rcall->tag);
req = NULL;
spin_lock(&m->lock);
list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
if (rreq->tag == rcall->tag) {
req = rreq;
if (req->flush != Flushing)
list_del(&req->req_list);
break;
}
}
spin_unlock(&m->lock);
if (req) {
req->rcall = rcall;
process_request(m, req);
if (req->flush != Flushing) {
if (req->cb)
(*req->cb) (req, req->cba);
else
kfree(req->rcall);
}
} else {
if (err >= 0 && rcall->id != P9_RFLUSH)
P9_DPRINTK(P9_DEBUG_ERROR,
"unexpected response mux %p id %d tag %d\n",
m, rcall->id, rcall->tag);
kfree(rcall);
}
}
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) {
P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
queue_work(p9_mux_wq, &m->rq);
} else
clear_bit(Rworksched, &m->wsched);
} else
clear_bit(Rworksched, &m->wsched);
return;
error:
p9_conn_cancel(m, err);
clear_bit(Rworksched, &m->wsched);
}
/**
* p9_send_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. Can return errors
* that can be retrieved by PTR_ERR macros.
*
* @m: mux data
* @tc: request to be sent
* @cb: callback function to call when response is received
* @cba: parameter to pass to the callback function
*
*/
static struct p9_req *p9_send_request(struct p9_conn *m,
struct p9_fcall *tc,
p9_conn_req_callback cb, void *cba)
{
int n;
struct p9_req *req;
P9_DPRINTK(P9_DEBUG_MUX, "mux %p task %p tcall %p id %d\n", m, current,
tc, tc->id);
if (m->err < 0)
return ERR_PTR(m->err);
req = kmalloc(sizeof(struct p9_req), GFP_KERNEL);
if (!req)
return ERR_PTR(-ENOMEM);
if (tc->id == P9_TVERSION)
n = P9_NOTAG;
else
n = p9_mux_get_tag(m);
if (n < 0) {
kfree(req);
return ERR_PTR(-ENOMEM);
}
p9_set_tag(tc, n);
#ifdef CONFIG_NET_9P_DEBUG
if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
char buf[150];
p9_printfcall(buf, sizeof(buf), tc, m->client->dotu);
printk(KERN_NOTICE "<<< %p %s\n", m, buf);
}
#endif
spin_lock_init(&req->lock);
req->tag = n;
req->tcall = tc;
req->rcall = NULL;
req->err = 0;
req->cb = cb;
req->cba = cba;
req->flush = None;
spin_lock(&m->lock);
list_add_tail(&req->req_list, &m->unsent_req_list);
spin_unlock(&m->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))
queue_work(p9_mux_wq, &m->wq);
return req;
}
static void p9_mux_free_request(struct p9_conn *m, struct p9_req *req)
{
p9_mux_put_tag(m, req->tag);
kfree(req);
}
static void p9_mux_flush_cb(struct p9_req *freq, void *a)
{
int tag;
struct p9_conn *m;
struct p9_req *req, *rreq, *rptr;
m = a;
P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m,
freq->tcall, freq->rcall, freq->err,
freq->tcall->params.tflush.oldtag);
spin_lock(&m->lock);
tag = freq->tcall->params.tflush.oldtag;
req = NULL;
list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
if (rreq->tag == tag) {
req = rreq;
list_del(&req->req_list);
break;
}
}
spin_unlock(&m->lock);
if (req) {
spin_lock(&req->lock);
req->flush = Flushed;
spin_unlock(&req->lock);
if (req->cb)
(*req->cb) (req, req->cba);
else
kfree(req->rcall);
}
kfree(freq->tcall);
kfree(freq->rcall);
p9_mux_free_request(m, freq);
}
static int
p9_mux_flush_request(struct p9_conn *m, struct p9_req *req)
{
struct p9_fcall *fc;
struct p9_req *rreq, *rptr;
P9_DPRINTK(P9_DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag);
/* if a response was received for a request, do nothing */
spin_lock(&req->lock);
if (req->rcall || req->err) {
spin_unlock(&req->lock);
P9_DPRINTK(P9_DEBUG_MUX,
"mux %p req %p response already received\n", m, req);
return 0;
}
req->flush = Flushing;
spin_unlock(&req->lock);
spin_lock(&m->lock);
/* if the request is not sent yet, just remove it from the list */
list_for_each_entry_safe(rreq, rptr, &m->unsent_req_list, req_list) {
if (rreq->tag == req->tag) {
P9_DPRINTK(P9_DEBUG_MUX,
"mux %p req %p request is not sent yet\n", m, req);
list_del(&rreq->req_list);
req->flush = Flushed;
spin_unlock(&m->lock);
if (req->cb)
(*req->cb) (req, req->cba);
return 0;
}
}
spin_unlock(&m->lock);
clear_thread_flag(TIF_SIGPENDING);
fc = p9_create_tflush(req->tag);
p9_send_request(m, fc, p9_mux_flush_cb, m);
return 1;
}
static void
p9_conn_rpc_cb(struct p9_req *req, void *a)
{
struct p9_mux_rpc *r;
P9_DPRINTK(P9_DEBUG_MUX, "req %p r %p\n", req, a);
r = a;
r->rcall = req->rcall;
r->err = req->err;
if (req->flush != None && !req->err)
r->err = -ERESTARTSYS;
wake_up(&r->wqueue);
}
/**
* p9_fd_rpc- sends 9P request and waits until a response is available.
* The function can be interrupted.
* @client: client instance
* @tc: request to be sent
* @rc: pointer where a pointer to the response is stored
*
*/
int
p9_fd_rpc(struct p9_client *client, struct p9_fcall *tc, struct p9_fcall **rc)
{
struct p9_trans_fd *p = client->trans;
struct p9_conn *m = p->conn;
int err, sigpending;
unsigned long flags;
struct p9_req *req;
struct p9_mux_rpc r;
r.err = 0;
r.tcall = tc;
r.rcall = NULL;
r.m = m;
init_waitqueue_head(&r.wqueue);
if (rc)
*rc = NULL;
sigpending = 0;
if (signal_pending(current)) {
sigpending = 1;
clear_thread_flag(TIF_SIGPENDING);
}
req = p9_send_request(m, tc, p9_conn_rpc_cb, &r);
if (IS_ERR(req)) {
err = PTR_ERR(req);
P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
return err;
}
err = wait_event_interruptible(r.wqueue, r.rcall != NULL || r.err < 0);
if (r.err < 0)
err = r.err;
if (err == -ERESTARTSYS && client->status == Connected
&& m->err == 0) {
if (p9_mux_flush_request(m, req)) {
/* wait until we get response of the flush message */
do {
clear_thread_flag(TIF_SIGPENDING);
err = wait_event_interruptible(r.wqueue,
r.rcall || r.err);
} while (!r.rcall && !r.err && err == -ERESTARTSYS &&
client->status == Connected && !m->err);
err = -ERESTARTSYS;
}
sigpending = 1;
}
if (sigpending) {
spin_lock_irqsave(&current->sighand->siglock, flags);
recalc_sigpending();
spin_unlock_irqrestore(&current->sighand->siglock, flags);
}
if (rc)
*rc = r.rcall;
else
kfree(r.rcall);
p9_mux_free_request(m, req);
if (err > 0)
err = -EIO;
return err;
}
#ifdef P9_NONBLOCK
/**
* p9_conn_rpcnb - sends 9P request without waiting for response.
* @m: mux data
* @tc: request to be sent
* @cb: callback function to be called when response arrives
* @a: value to pass to the callback function
*
*/
int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
p9_conn_req_callback cb, void *a)
{
int err;
struct p9_req *req;
req = p9_send_request(m, tc, cb, a);
if (IS_ERR(req)) {
err = PTR_ERR(req);
P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
return PTR_ERR(req);
}
P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p tag %d\n", m, tc, req->tag);
return 0;
}
#endif /* P9_NONBLOCK */
/**
* p9_conn_cancel - cancel all pending requests with error
* @m: mux data
* @err: error code
*
*/
void p9_conn_cancel(struct p9_conn *m, int err)
{
struct p9_req *req, *rtmp;
LIST_HEAD(cancel_list);
P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
m->err = err;
spin_lock(&m->lock);
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(&m->lock);
list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
list_del(&req->req_list);
if (!req->err)
req->err = err;
if (req->cb)
(*req->cb) (req, req->cba);
else
kfree(req->rcall);
}
}
/**
* parse_options - parse mount options into session structure
* @options: options string passed from mount
* @opts: transport-specific structure to parse options into
*
* Returns 0 upon success, -ERRNO upon failure
*/
static int parse_opts(char *params, struct p9_fd_opts *opts)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int option;
char *options;
int ret;
opts->port = P9_PORT;
opts->rfd = ~0;
opts->wfd = ~0;
if (!params)
return 0;
options = kstrdup(params, GFP_KERNEL);
if (!options) {
P9_DPRINTK(P9_DEBUG_ERROR,
"failed to allocate copy of option string\n");
return -ENOMEM;
}
while ((p = strsep(&options, ",")) != NULL) {
int token;
int r;
if (!*p)
continue;
token = match_token(p, tokens, args);
r = match_int(&args[0], &option);
if (r < 0) {
P9_DPRINTK(P9_DEBUG_ERROR,
"integer field, but no integer?\n");
ret = r;
continue;
}
switch (token) {
case Opt_port:
opts->port = option;
break;
case Opt_rfdno:
opts->rfd = option;
break;
case Opt_wfdno:
opts->wfd = option;
break;
default:
continue;
}
}
kfree(options);
return 0;
}
static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
{
struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
GFP_KERNEL);
if (!ts)
return -ENOMEM;
ts->rd = fget(rfd);
ts->wr = fget(wfd);
if (!ts->rd || !ts->wr) {
if (ts->rd)
fput(ts->rd);
if (ts->wr)
fput(ts->wr);
kfree(ts);
return -EIO;
}
client->trans = ts;
client->status = Connected;
return 0;
}
static int p9_socket_open(struct p9_client *client, struct socket *csocket)
{
int fd, ret;
csocket->sk->sk_allocation = GFP_NOIO;
flag parameters: socket and socketpair This patch adds support for flag values which are ORed to the type passwd to socket and socketpair. The additional code is minimal. The flag values in this implementation can and must match the O_* flags. This avoids overhead in the conversion. The internal functions sock_alloc_fd and sock_map_fd get a new parameters and all callers are changed. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #include <fcntl.h> #include <stdio.h> #include <unistd.h> #include <netinet/in.h> #include <sys/socket.h> #define PORT 57392 /* For Linux these must be the same. */ #define SOCK_CLOEXEC O_CLOEXEC int main (void) { int fd; fd = socket (PF_INET, SOCK_STREAM, 0); if (fd == -1) { puts ("socket(0) failed"); return 1; } int coe = fcntl (fd, F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if (coe & FD_CLOEXEC) { puts ("socket(0) set close-on-exec flag"); return 1; } close (fd); fd = socket (PF_INET, SOCK_STREAM|SOCK_CLOEXEC, 0); if (fd == -1) { puts ("socket(SOCK_CLOEXEC) failed"); return 1; } coe = fcntl (fd, F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if ((coe & FD_CLOEXEC) == 0) { puts ("socket(SOCK_CLOEXEC) does not set close-on-exec flag"); return 1; } close (fd); int fds[2]; if (socketpair (PF_UNIX, SOCK_STREAM, 0, fds) == -1) { puts ("socketpair(0) failed"); return 1; } for (int i = 0; i < 2; ++i) { coe = fcntl (fds[i], F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if (coe & FD_CLOEXEC) { printf ("socketpair(0) set close-on-exec flag for fds[%d]\n", i); return 1; } close (fds[i]); } if (socketpair (PF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0, fds) == -1) { puts ("socketpair(SOCK_CLOEXEC) failed"); return 1; } for (int i = 0; i < 2; ++i) { coe = fcntl (fds[i], F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if ((coe & FD_CLOEXEC) == 0) { printf ("socketpair(SOCK_CLOEXEC) does not set close-on-exec flag for fds[%d]\n", i); return 1; } close (fds[i]); } puts ("OK"); return 0; } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 04:29:17 +00:00
fd = sock_map_fd(csocket, 0);
if (fd < 0) {
P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
return fd;
}
ret = p9_fd_open(client, fd, fd);
if (ret < 0) {
P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to open fd\n");
sockfd_put(csocket);
return ret;
}
((struct p9_trans_fd *)client->trans)->rd->f_flags |= O_NONBLOCK;
return 0;
}
/**
* 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_DPRINTK(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;
}
/**
* 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_DPRINTK(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, (void __user *)v, len, &ts->wr->f_pos);
set_fs(oldfs);
if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
client->status = Disconnected;
return ret;
}
static unsigned 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 || !ts->rd->f_op->poll)
return -EIO;
if (!ts->wr->f_op || !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;
}
/**
* p9_fd_close - shutdown file descriptor transport
* @client: client instance
*
*/
static void p9_fd_close(struct p9_client *client)
{
struct p9_trans_fd *ts;
if (!client)
return;
ts = client->trans;
if (!ts)
return;
client->status = Disconnected;
p9_conn_destroy(ts->conn);
if (ts->rd)
fput(ts->rd);
if (ts->wr)
fput(ts->wr);
kfree(ts);
}
/*
* stolen from NFS - maybe should be made a generic function?
*/
static inline int valid_ipaddr4(const char *buf)
{
int rc, count, in[4];
rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
if (rc != 4)
return -EINVAL;
for (count = 0; count < 4; count++) {
if (in[count] > 255)
return -EINVAL;
}
return 0;
}
static int
p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
{
int err;
struct socket *csocket;
struct sockaddr_in sin_server;
struct p9_fd_opts opts;
struct p9_trans_fd *p = NULL; /* this gets allocated in p9_fd_open */
err = parse_opts(args, &opts);
if (err < 0)
return err;
if (valid_ipaddr4(addr) < 0)
return -EINVAL;
csocket = NULL;
sin_server.sin_family = AF_INET;
sin_server.sin_addr.s_addr = in_aton(addr);
sin_server.sin_port = htons(opts.port);
sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
if (!csocket) {
P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
err = -EIO;
goto error;
}
err = csocket->ops->connect(csocket,
(struct sockaddr *)&sin_server,
sizeof(struct sockaddr_in), 0);
if (err < 0) {
P9_EPRINTK(KERN_ERR,
"p9_trans_tcp: problem connecting socket to %s\n",
addr);
goto error;
}
err = p9_socket_open(client, csocket);
if (err < 0)
goto error;
p = (struct p9_trans_fd *) client->trans;
p->conn = p9_conn_create(client);
if (IS_ERR(p->conn)) {
err = PTR_ERR(p->conn);
p->conn = NULL;
goto error;
}
return 0;
error:
if (csocket)
sock_release(csocket);
kfree(p);
return err;
}
static int
p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
{
int err;
struct socket *csocket;
struct sockaddr_un sun_server;
struct p9_trans_fd *p = NULL; /* this gets allocated in p9_fd_open */
csocket = NULL;
if (strlen(addr) > UNIX_PATH_MAX) {
P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
addr);
err = -ENAMETOOLONG;
goto error;
}
sun_server.sun_family = PF_UNIX;
strcpy(sun_server.sun_path, addr);
sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
sizeof(struct sockaddr_un) - 1, 0);
if (err < 0) {
P9_EPRINTK(KERN_ERR,
"p9_trans_unix: problem connecting socket: %s: %d\n",
addr, err);
goto error;
}
err = p9_socket_open(client, csocket);
if (err < 0)
goto error;
p = (struct p9_trans_fd *) client->trans;
p->conn = p9_conn_create(client);
if (IS_ERR(p->conn)) {
err = PTR_ERR(p->conn);
p->conn = NULL;
goto error;
}
return 0;
error:
if (csocket)
sock_release(csocket);
kfree(p);
return err;
}
static int
p9_fd_create(struct p9_client *client, const char *addr, char *args)
{
int err;
struct p9_fd_opts opts;
struct p9_trans_fd *p = NULL; /* this get allocated in p9_fd_open */
parse_opts(args, &opts);
if (opts.rfd == ~0 || opts.wfd == ~0) {
printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
return -ENOPROTOOPT;
}
err = p9_fd_open(client, opts.rfd, opts.wfd);
if (err < 0)
goto error;
p = (struct p9_trans_fd *) client->trans;
p->conn = p9_conn_create(client);
if (IS_ERR(p->conn)) {
err = PTR_ERR(p->conn);
p->conn = NULL;
goto error;
}
return 0;
error:
kfree(p);
return err;
}
static struct p9_trans_module p9_tcp_trans = {
.name = "tcp",
.maxsize = MAX_SOCK_BUF,
.def = 1,
.create = p9_fd_create_tcp,
.close = p9_fd_close,
.rpc = p9_fd_rpc,
.owner = THIS_MODULE,
};
static struct p9_trans_module p9_unix_trans = {
.name = "unix",
.maxsize = MAX_SOCK_BUF,
.def = 0,
.create = p9_fd_create_unix,
.close = p9_fd_close,
.rpc = p9_fd_rpc,
.owner = THIS_MODULE,
};
static struct p9_trans_module p9_fd_trans = {
.name = "fd",
.maxsize = MAX_SOCK_BUF,
.def = 0,
.create = p9_fd_create,
.close = p9_fd_close,
.rpc = p9_fd_rpc,
.owner = THIS_MODULE,
};
int p9_trans_fd_init(void)
{
p9_mux_wq = create_workqueue("v9fs");
if (!p9_mux_wq) {
printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
return -ENOMEM;
}
p9_poll_task = kthread_run(p9_poll_proc, NULL, "v9fs-poll");
if (IS_ERR(p9_poll_task)) {
destroy_workqueue(p9_mux_wq);
printk(KERN_WARNING "v9fs: mux: creating poll task failed\n");
return PTR_ERR(p9_poll_task);
}
v9fs_register_trans(&p9_tcp_trans);
v9fs_register_trans(&p9_unix_trans);
v9fs_register_trans(&p9_fd_trans);
return 0;
}
void p9_trans_fd_exit(void)
{
kthread_stop(p9_poll_task);
v9fs_unregister_trans(&p9_tcp_trans);
v9fs_unregister_trans(&p9_unix_trans);
v9fs_unregister_trans(&p9_fd_trans);
destroy_workqueue(p9_mux_wq);
}