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linux/net/9p/trans_fd.c
Eric Van Hensbergen bb8ffdfc3e 9p: propagate parse_option changes to client and transports 
Propagate changes that were made to the parse_options code to the
other parse options pieces present in the other modules.  Looks like
the client parse options was probably corrupting the parse string
and causing problems for others.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-05-14 19:23:26 -05:00

1648 lines
35 KiB
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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/transport.h>
#define P9_PORT 564
#define MAX_SOCK_BUF (64*1024)
#define ERREQFLUSH 1
#define SCHED_TIMEOUT 10
#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 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_mux_poll_task {
struct task_struct *task;
struct list_head mux_list;
int muxnum;
};
/**
* struct p9_conn - fd mux connection state information
* @lock: protects mux_list (?)
* @mux_list: list link for mux to manage multiple connections (?)
* @poll_task: task polling on this connection
* @msize: maximum size for connection (dup)
* @extended: 9p2000.u flag (dup)
* @trans: reference to transport instance for this connection
* @tagpool: id accounting for transactions
* @err: error state
* @equeue: event wait_q (?)
* @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_mux_poll_task *poll_task;
int msize;
unsigned char extended;
struct p9_trans *trans;
struct p9_idpool *tagpool;
int err;
wait_queue_head_t equeue;
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;
wait_queue_t poll_wait[MAXPOLLWADDR];
wait_queue_head_t *poll_waddr[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_trans *trans, void *v, int len);
static int p9_fd_read(struct p9_trans *trans, void *v, int len);
static DEFINE_MUTEX(p9_mux_task_lock);
static struct workqueue_struct *p9_mux_wq;
static int p9_mux_num;
static int p9_mux_poll_task_num;
static struct p9_mux_poll_task p9_mux_poll_tasks[100];
static void p9_conn_destroy(struct p9_conn *);
static unsigned int p9_fd_poll(struct p9_trans *trans,
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 int p9_mux_global_init(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++)
p9_mux_poll_tasks[i].task = NULL;
p9_mux_wq = create_workqueue("v9fs");
if (!p9_mux_wq) {
printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
return -ENOMEM;
}
return 0;
}
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);
}
/**
* p9_mux_calc_poll_procs - calculates the number of polling procs
* @muxnum: number of mounts
*
* Calculation is based on the number of mounted v9fs filesystems.
* The current implementation returns sqrt of the number of mounts.
*/
static int p9_mux_calc_poll_procs(int muxnum)
{
int n;
if (p9_mux_poll_task_num)
n = muxnum / p9_mux_poll_task_num +
(muxnum % p9_mux_poll_task_num ? 1 : 0);
else
n = 1;
if (n > ARRAY_SIZE(p9_mux_poll_tasks))
n = ARRAY_SIZE(p9_mux_poll_tasks);
return n;
}
static int p9_mux_poll_start(struct p9_conn *m)
{
int i, n;
struct p9_mux_poll_task *vpt, *vptlast;
struct task_struct *pproc;
P9_DPRINTK(P9_DEBUG_MUX, "mux %p muxnum %d procnum %d\n", m, p9_mux_num,
p9_mux_poll_task_num);
mutex_lock(&p9_mux_task_lock);
n = p9_mux_calc_poll_procs(p9_mux_num + 1);
if (n > p9_mux_poll_task_num) {
for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++) {
if (p9_mux_poll_tasks[i].task == NULL) {
vpt = &p9_mux_poll_tasks[i];
P9_DPRINTK(P9_DEBUG_MUX, "create proc %p\n",
vpt);
pproc = kthread_create(p9_poll_proc, vpt,
"v9fs-poll");
if (!IS_ERR(pproc)) {
vpt->task = pproc;
INIT_LIST_HEAD(&vpt->mux_list);
vpt->muxnum = 0;
p9_mux_poll_task_num++;
wake_up_process(vpt->task);
}
break;
}
}
if (i >= ARRAY_SIZE(p9_mux_poll_tasks))
P9_DPRINTK(P9_DEBUG_ERROR,
"warning: no free poll slots\n");
}
n = (p9_mux_num + 1) / p9_mux_poll_task_num +
((p9_mux_num + 1) % p9_mux_poll_task_num ? 1 : 0);
vptlast = NULL;
for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++) {
vpt = &p9_mux_poll_tasks[i];
if (vpt->task != NULL) {
vptlast = vpt;
if (vpt->muxnum < n) {
P9_DPRINTK(P9_DEBUG_MUX, "put in proc %d\n", i);
list_add(&m->mux_list, &vpt->mux_list);
vpt->muxnum++;
m->poll_task = vpt;
memset(&m->poll_waddr, 0,
sizeof(m->poll_waddr));
init_poll_funcptr(&m->pt, p9_pollwait);
break;
}
}
}
if (i >= ARRAY_SIZE(p9_mux_poll_tasks)) {
if (vptlast == NULL) {
mutex_unlock(&p9_mux_task_lock);
return -ENOMEM;
}
P9_DPRINTK(P9_DEBUG_MUX, "put in proc %d\n", i);
list_add(&m->mux_list, &vptlast->mux_list);
vptlast->muxnum++;
m->poll_task = vptlast;
memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
init_poll_funcptr(&m->pt, p9_pollwait);
}
p9_mux_num++;
mutex_unlock(&p9_mux_task_lock);
return 0;
}
static void p9_mux_poll_stop(struct p9_conn *m)
{
int i;
struct p9_mux_poll_task *vpt;
mutex_lock(&p9_mux_task_lock);
vpt = m->poll_task;
list_del(&m->mux_list);
for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) {
if (m->poll_waddr[i] != NULL) {
remove_wait_queue(m->poll_waddr[i], &m->poll_wait[i]);
m->poll_waddr[i] = NULL;
}
}
vpt->muxnum--;
if (!vpt->muxnum) {
P9_DPRINTK(P9_DEBUG_MUX, "destroy proc %p\n", vpt);
kthread_stop(vpt->task);
vpt->task = NULL;
p9_mux_poll_task_num--;
}
p9_mux_num--;
mutex_unlock(&p9_mux_task_lock);
}
/**
* p9_conn_create - allocate and initialize the per-session mux data
* @trans: transport structure
*
* Note: Creates the polling task if this is the first session.
*/
static struct p9_conn *p9_conn_create(struct p9_trans *trans)
{
int i, n;
struct p9_conn *m, *mtmp;
P9_DPRINTK(P9_DEBUG_MUX, "transport %p msize %d\n", trans,
trans->msize);
m = kmalloc(sizeof(struct p9_conn), GFP_KERNEL);
if (!m)
return ERR_PTR(-ENOMEM);
spin_lock_init(&m->lock);
INIT_LIST_HEAD(&m->mux_list);
m->msize = trans->msize;
m->extended = trans->extended;
m->trans = trans;
m->tagpool = p9_idpool_create();
if (IS_ERR(m->tagpool)) {
mtmp = ERR_PTR(-ENOMEM);
kfree(m);
return mtmp;
}
m->err = 0;
init_waitqueue_head(&m->equeue);
INIT_LIST_HEAD(&m->req_list);
INIT_LIST_HEAD(&m->unsent_req_list);
m->rcall = NULL;
m->rpos = 0;
m->rbuf = NULL;
m->wpos = m->wsize = 0;
m->wbuf = NULL;
INIT_WORK(&m->rq, p9_read_work);
INIT_WORK(&m->wq, p9_write_work);
m->wsched = 0;
memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
m->poll_task = NULL;
n = p9_mux_poll_start(m);
if (n) {
kfree(m);
return ERR_PTR(n);
}
n = p9_fd_poll(trans, &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_waddr); i++) {
if (IS_ERR(m->poll_waddr[i])) {
p9_mux_poll_stop(m);
mtmp = (void *)m->poll_waddr; /* the error code */
kfree(m);
m = mtmp;
break;
}
}
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_conn_cancel(m, -ECONNRESET);
if (!list_empty(&m->req_list)) {
/* wait until all processes waiting on this session exit */
P9_DPRINTK(P9_DEBUG_MUX,
"mux %p waiting for empty request queue\n", m);
wait_event_timeout(m->equeue, (list_empty(&m->req_list)), 5000);
P9_DPRINTK(P9_DEBUG_MUX, "mux %p request queue empty: %d\n", m,
list_empty(&m->req_list));
}
p9_mux_poll_stop(m);
m->trans = NULL;
p9_idpool_destroy(m->tagpool);
kfree(m);
}
/**
* 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)
{
int i;
struct p9_conn *m;
m = container_of(p, struct p9_conn, pt);
for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++)
if (m->poll_waddr[i] == NULL)
break;
if (i >= ARRAY_SIZE(m->poll_waddr)) {
P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
return;
}
m->poll_waddr[i] = wait_address;
if (!wait_address) {
P9_DPRINTK(P9_DEBUG_ERROR, "no wait_address\n");
m->poll_waddr[i] = ERR_PTR(-EIO);
return;
}
init_waitqueue_entry(&m->poll_wait[i], m->poll_task->task);
add_wait_queue(wait_address, &m->poll_wait[i]);
}
/**
* 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->trans, 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)
{
struct p9_conn *m, *mtmp;
struct p9_mux_poll_task *vpt;
vpt = a;
P9_DPRINTK(P9_DEBUG_MUX, "start %p %p\n", current, vpt);
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
list_for_each_entry_safe(m, mtmp, &vpt->mux_list, mux_list) {
p9_poll_mux(m);
}
P9_DPRINTK(P9_DEBUG_MUX, "sleeping...\n");
schedule_timeout(SCHED_TIMEOUT * HZ);
}
__set_current_state(TASK_RUNNING);
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->trans, 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->trans, 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->extended)
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->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->trans, m->rbuf + m->rpos, m->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->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->extended);
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->extended);
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->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);
wake_up(&m->equeue);
}
} 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->trans, 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)
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->extended);
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->trans, 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);
wake_up(&m->equeue);
}
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.
* @t: transport data
* @tc: request to be sent
* @rc: pointer where a pointer to the response is stored
*
*/
int
p9_fd_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
{
struct p9_trans_fd *p = t->priv;
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 && m->trans->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 &&
m->trans->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);
}
wake_up(&m->equeue);
}
/**
* 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_trans *trans, 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;
}
trans->priv = ts;
trans->status = Connected;
return 0;
}
static int p9_socket_open(struct p9_trans *trans, struct socket *csocket)
{
int fd, ret;
csocket->sk->sk_allocation = GFP_NOIO;
fd = sock_map_fd(csocket);
if (fd < 0) {
P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
return fd;
}
ret = p9_fd_open(trans, 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 *)trans->priv)->rd->f_flags |= O_NONBLOCK;
return 0;
}
/**
* p9_fd_read- read from a fd
* @trans: transport instance state
* @v: buffer to receive data into
* @len: size of receive buffer
*
*/
static int p9_fd_read(struct p9_trans *trans, void *v, int len)
{
int ret;
struct p9_trans_fd *ts = NULL;
if (trans && trans->status != Disconnected)
ts = trans->priv;
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)
trans->status = Disconnected;
return ret;
}
/**
* p9_fd_write - write to a socket
* @trans: transport instance state
* @v: buffer to send data from
* @len: size of send buffer
*
*/
static int p9_fd_write(struct p9_trans *trans, void *v, int len)
{
int ret;
mm_segment_t oldfs;
struct p9_trans_fd *ts = NULL;
if (trans && trans->status != Disconnected)
ts = trans->priv;
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)
trans->status = Disconnected;
return ret;
}
static unsigned int
p9_fd_poll(struct p9_trans *trans, struct poll_table_struct *pt)
{
int ret, n;
struct p9_trans_fd *ts = NULL;
mm_segment_t oldfs;
if (trans && trans->status == Connected)
ts = trans->priv;
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;
oldfs = get_fs();
set_fs(get_ds());
ret = ts->rd->f_op->poll(ts->rd, pt);
if (ret < 0)
goto end;
if (ts->rd != ts->wr) {
n = ts->wr->f_op->poll(ts->wr, pt);
if (n < 0) {
ret = n;
goto end;
}
ret = (ret & ~POLLOUT) | (n & ~POLLIN);
}
end:
set_fs(oldfs);
return ret;
}
/**
* p9_fd_close - shutdown socket
* @trans: private socket structure
*
*/
static void p9_fd_close(struct p9_trans *trans)
{
struct p9_trans_fd *ts;
if (!trans)
return;
ts = xchg(&trans->priv, NULL);
if (!ts)
return;
p9_conn_destroy(ts->conn);
trans->status = Disconnected;
if (ts->rd)
fput(ts->rd);
if (ts->wr)
fput(ts->wr);
kfree(ts);
}
static struct p9_trans *
p9_trans_create_tcp(const char *addr, char *args, int msize, unsigned char dotu)
{
int err;
struct p9_trans *trans;
struct socket *csocket;
struct sockaddr_in sin_server;
struct p9_fd_opts opts;
struct p9_trans_fd *p;
err = parse_opts(args, &opts);
if (err < 0)
return ERR_PTR(err);
csocket = NULL;
trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
if (!trans)
return ERR_PTR(-ENOMEM);
trans->msize = msize;
trans->extended = dotu;
trans->rpc = p9_fd_rpc;
trans->close = p9_fd_close;
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(trans, csocket);
if (err < 0)
goto error;
p = (struct p9_trans_fd *) trans->priv;
p->conn = p9_conn_create(trans);
if (IS_ERR(p->conn)) {
err = PTR_ERR(p->conn);
p->conn = NULL;
goto error;
}
return trans;
error:
if (csocket)
sock_release(csocket);
kfree(trans);
return ERR_PTR(err);
}
static struct p9_trans *
p9_trans_create_unix(const char *addr, char *args, int msize,
unsigned char dotu)
{
int err;
struct socket *csocket;
struct sockaddr_un sun_server;
struct p9_trans *trans;
struct p9_trans_fd *p;
csocket = NULL;
trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
if (!trans)
return ERR_PTR(-ENOMEM);
trans->rpc = p9_fd_rpc;
trans->close = p9_fd_close;
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(trans, csocket);
if (err < 0)
goto error;
trans->msize = msize;
trans->extended = dotu;
p = (struct p9_trans_fd *) trans->priv;
p->conn = p9_conn_create(trans);
if (IS_ERR(p->conn)) {
err = PTR_ERR(p->conn);
p->conn = NULL;
goto error;
}
return trans;
error:
if (csocket)
sock_release(csocket);
kfree(trans);
return ERR_PTR(err);
}
static struct p9_trans *
p9_trans_create_fd(const char *name, char *args, int msize,
unsigned char extended)
{
int err;
struct p9_trans *trans;
struct p9_fd_opts opts;
struct p9_trans_fd *p;
parse_opts(args, &opts);
if (opts.rfd == ~0 || opts.wfd == ~0) {
printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
return ERR_PTR(-ENOPROTOOPT);
}
trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
if (!trans)
return ERR_PTR(-ENOMEM);
trans->rpc = p9_fd_rpc;
trans->close = p9_fd_close;
err = p9_fd_open(trans, opts.rfd, opts.wfd);
if (err < 0)
goto error;
trans->msize = msize;
trans->extended = extended;
p = (struct p9_trans_fd *) trans->priv;
p->conn = p9_conn_create(trans);
if (IS_ERR(p->conn)) {
err = PTR_ERR(p->conn);
p->conn = NULL;
goto error;
}
return trans;
error:
kfree(trans);
return ERR_PTR(err);
}
static struct p9_trans_module p9_tcp_trans = {
.name = "tcp",
.maxsize = MAX_SOCK_BUF,
.def = 1,
.create = p9_trans_create_tcp,
};
static struct p9_trans_module p9_unix_trans = {
.name = "unix",
.maxsize = MAX_SOCK_BUF,
.def = 0,
.create = p9_trans_create_unix,
};
static struct p9_trans_module p9_fd_trans = {
.name = "fd",
.maxsize = MAX_SOCK_BUF,
.def = 0,
.create = p9_trans_create_fd,
};
static int __init p9_trans_fd_init(void)
{
int ret = p9_mux_global_init();
if (ret) {
printk(KERN_WARNING "9p: starting mux failed\n");
return ret;
}
v9fs_register_trans(&p9_tcp_trans);
v9fs_register_trans(&p9_unix_trans);
v9fs_register_trans(&p9_fd_trans);
return 0;
}
module_init(p9_trans_fd_init);
MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
MODULE_LICENSE("GPL");
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