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kernel-fxtec-pro1x/net/9p/trans_fd.c
Tejun Heo 206ca50de7 9p-trans_fd: fix and clean up module init/exit paths 
trans_fd leaked p9_mux_wq on module unload.  Fix it.  While at it,
collapse p9_mux_global_init() into p9_trans_fd_init().  It's easier to
follow this way and the global poll_tasks array is about to removed
anyway.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-09-24 16:22:23 -05:00

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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
* @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;
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 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;
P9_DPRINTK(P9_DEBUG_MUX, "transport %p msize %d\n", trans,
trans->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->msize = trans->msize;
m->extended = trans->extended;
m->trans = trans;
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);
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);
kfree(m);
return (void *)m->poll_waddr; /* the error code */
}
}
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->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);
}
} 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) {
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->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);
}
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);
}
}
/**
* 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, 0);
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;
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;
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 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);
}
/*
* 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 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);
if (valid_ipaddr4(addr) < 0)
return ERR_PTR(-EINVAL);
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,
.owner = THIS_MODULE,
};
static struct p9_trans_module p9_unix_trans = {
.name = "unix",
.maxsize = MAX_SOCK_BUF,
.def = 0,
.create = p9_trans_create_unix,
.owner = THIS_MODULE,
};
static struct p9_trans_module p9_fd_trans = {
.name = "fd",
.maxsize = MAX_SOCK_BUF,
.def = 0,
.create = p9_trans_create_fd,
.owner = THIS_MODULE,
};
int p9_trans_fd_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;
}
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)
{
v9fs_unregister_trans(&p9_tcp_trans);
v9fs_unregister_trans(&p9_unix_trans);
v9fs_unregister_trans(&p9_fd_trans);
destroy_workqueue(p9_mux_wq);
}
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