~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/9p/trans_fd.c

Version: ~ [ linux-5.5-rc1 ] ~ [ linux-5.4.2 ] ~ [ linux-5.3.15 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.88 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.158 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.206 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.206 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.78 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * linux/fs/9p/trans_fd.c
  3  *
  4  * Fd transport layer.  Includes deprecated socket layer.
  5  *
  6  *  Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
  7  *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
  8  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
  9  *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
 10  *
 11  *  This program is free software; you can redistribute it and/or modify
 12  *  it under the terms of the GNU General Public License version 2
 13  *  as published by the Free Software Foundation.
 14  *
 15  *  This program is distributed in the hope that it will be useful,
 16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 18  *  GNU General Public License for more details.
 19  *
 20  *  You should have received a copy of the GNU General Public License
 21  *  along with this program; if not, write to:
 22  *  Free Software Foundation
 23  *  51 Franklin Street, Fifth Floor
 24  *  Boston, MA  02111-1301  USA
 25  *
 26  */
 27 
 28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 29 
 30 #include <linux/in.h>
 31 #include <linux/module.h>
 32 #include <linux/net.h>
 33 #include <linux/ipv6.h>
 34 #include <linux/kthread.h>
 35 #include <linux/errno.h>
 36 #include <linux/kernel.h>
 37 #include <linux/un.h>
 38 #include <linux/uaccess.h>
 39 #include <linux/inet.h>
 40 #include <linux/idr.h>
 41 #include <linux/file.h>
 42 #include <linux/parser.h>
 43 #include <linux/slab.h>
 44 #include <net/9p/9p.h>
 45 #include <net/9p/client.h>
 46 #include <net/9p/transport.h>
 47 
 48 #include <linux/syscalls.h> /* killme */
 49 
 50 #define P9_PORT 564
 51 #define MAX_SOCK_BUF (64*1024)
 52 #define MAXPOLLWADDR    2
 53 
 54 /**
 55  * struct p9_fd_opts - per-transport options
 56  * @rfd: file descriptor for reading (trans=fd)
 57  * @wfd: file descriptor for writing (trans=fd)
 58  * @port: port to connect to (trans=tcp)
 59  *
 60  */
 61 
 62 struct p9_fd_opts {
 63         int rfd;
 64         int wfd;
 65         u16 port;
 66 };
 67 
 68 /**
 69  * struct p9_trans_fd - transport state
 70  * @rd: reference to file to read from
 71  * @wr: reference of file to write to
 72  * @conn: connection state reference
 73  *
 74  */
 75 
 76 struct p9_trans_fd {
 77         struct file *rd;
 78         struct file *wr;
 79         struct p9_conn *conn;
 80 };
 81 
 82 /*
 83   * Option Parsing (code inspired by NFS code)
 84   *  - a little lazy - parse all fd-transport options
 85   */
 86 
 87 enum {
 88         /* Options that take integer arguments */
 89         Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
 90 };
 91 
 92 static const match_table_t tokens = {
 93         {Opt_port, "port=%u"},
 94         {Opt_rfdno, "rfdno=%u"},
 95         {Opt_wfdno, "wfdno=%u"},
 96         {Opt_err, NULL},
 97 };
 98 
 99 enum {
100         Rworksched = 1,         /* read work scheduled or running */
101         Rpending = 2,           /* can read */
102         Wworksched = 4,         /* write work scheduled or running */
103         Wpending = 8,           /* can write */
104 };
105 
106 struct p9_poll_wait {
107         struct p9_conn *conn;
108         wait_queue_t wait;
109         wait_queue_head_t *wait_addr;
110 };
111 
112 /**
113  * struct p9_conn - fd mux connection state information
114  * @mux_list: list link for mux to manage multiple connections (?)
115  * @client: reference to client instance for this connection
116  * @err: error state
117  * @req_list: accounting for requests which have been sent
118  * @unsent_req_list: accounting for requests that haven't been sent
119  * @req: current request being processed (if any)
120  * @tmp_buf: temporary buffer to read in header
121  * @rsize: amount to read for current frame
122  * @rpos: read position in current frame
123  * @rbuf: current read buffer
124  * @wpos: write position for current frame
125  * @wsize: amount of data to write for current frame
126  * @wbuf: current write buffer
127  * @poll_pending_link: pending links to be polled per conn
128  * @poll_wait: array of wait_q's for various worker threads
129  * @pt: poll state
130  * @rq: current read work
131  * @wq: current write work
132  * @wsched: ????
133  *
134  */
135 
136 struct p9_conn {
137         struct list_head mux_list;
138         struct p9_client *client;
139         int err;
140         struct list_head req_list;
141         struct list_head unsent_req_list;
142         struct p9_req_t *req;
143         char tmp_buf[7];
144         int rsize;
145         int rpos;
146         char *rbuf;
147         int wpos;
148         int wsize;
149         char *wbuf;
150         struct list_head poll_pending_link;
151         struct p9_poll_wait poll_wait[MAXPOLLWADDR];
152         poll_table pt;
153         struct work_struct rq;
154         struct work_struct wq;
155         unsigned long wsched;
156 };
157 
158 static void p9_poll_workfn(struct work_struct *work);
159 
160 static DEFINE_SPINLOCK(p9_poll_lock);
161 static LIST_HEAD(p9_poll_pending_list);
162 static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
163 
164 static void p9_mux_poll_stop(struct p9_conn *m)
165 {
166         unsigned long flags;
167         int i;
168 
169         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
170                 struct p9_poll_wait *pwait = &m->poll_wait[i];
171 
172                 if (pwait->wait_addr) {
173                         remove_wait_queue(pwait->wait_addr, &pwait->wait);
174                         pwait->wait_addr = NULL;
175                 }
176         }
177 
178         spin_lock_irqsave(&p9_poll_lock, flags);
179         list_del_init(&m->poll_pending_link);
180         spin_unlock_irqrestore(&p9_poll_lock, flags);
181 }
182 
183 /**
184  * p9_conn_cancel - cancel all pending requests with error
185  * @m: mux data
186  * @err: error code
187  *
188  */
189 
190 static void p9_conn_cancel(struct p9_conn *m, int err)
191 {
192         struct p9_req_t *req, *rtmp;
193         unsigned long flags;
194         LIST_HEAD(cancel_list);
195 
196         p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
197 
198         spin_lock_irqsave(&m->client->lock, flags);
199 
200         if (m->err) {
201                 spin_unlock_irqrestore(&m->client->lock, flags);
202                 return;
203         }
204 
205         m->err = err;
206 
207         list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
208                 req->status = REQ_STATUS_ERROR;
209                 if (!req->t_err)
210                         req->t_err = err;
211                 list_move(&req->req_list, &cancel_list);
212         }
213         list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
214                 req->status = REQ_STATUS_ERROR;
215                 if (!req->t_err)
216                         req->t_err = err;
217                 list_move(&req->req_list, &cancel_list);
218         }
219         spin_unlock_irqrestore(&m->client->lock, flags);
220 
221         list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
222                 p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
223                 list_del(&req->req_list);
224                 p9_client_cb(m->client, req);
225         }
226 }
227 
228 static int
229 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
230 {
231         int ret, n;
232         struct p9_trans_fd *ts = NULL;
233 
234         if (client && client->status == Connected)
235                 ts = client->trans;
236 
237         if (!ts)
238                 return -EREMOTEIO;
239 
240         if (!ts->rd->f_op || !ts->rd->f_op->poll)
241                 return -EIO;
242 
243         if (!ts->wr->f_op || !ts->wr->f_op->poll)
244                 return -EIO;
245 
246         ret = ts->rd->f_op->poll(ts->rd, pt);
247         if (ret < 0)
248                 return ret;
249 
250         if (ts->rd != ts->wr) {
251                 n = ts->wr->f_op->poll(ts->wr, pt);
252                 if (n < 0)
253                         return n;
254                 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
255         }
256 
257         return ret;
258 }
259 
260 /**
261  * p9_fd_read- read from a fd
262  * @client: client instance
263  * @v: buffer to receive data into
264  * @len: size of receive buffer
265  *
266  */
267 
268 static int p9_fd_read(struct p9_client *client, void *v, int len)
269 {
270         int ret;
271         struct p9_trans_fd *ts = NULL;
272 
273         if (client && client->status != Disconnected)
274                 ts = client->trans;
275 
276         if (!ts)
277                 return -EREMOTEIO;
278 
279         if (!(ts->rd->f_flags & O_NONBLOCK))
280                 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
281 
282         ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
283         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
284                 client->status = Disconnected;
285         return ret;
286 }
287 
288 /**
289  * p9_read_work - called when there is some data to be read from a transport
290  * @work: container of work to be done
291  *
292  */
293 
294 static void p9_read_work(struct work_struct *work)
295 {
296         int n, err;
297         struct p9_conn *m;
298 
299         m = container_of(work, struct p9_conn, rq);
300 
301         if (m->err < 0)
302                 return;
303 
304         p9_debug(P9_DEBUG_TRANS, "start mux %p pos %d\n", m, m->rpos);
305 
306         if (!m->rbuf) {
307                 m->rbuf = m->tmp_buf;
308                 m->rpos = 0;
309                 m->rsize = 7; /* start by reading header */
310         }
311 
312         clear_bit(Rpending, &m->wsched);
313         p9_debug(P9_DEBUG_TRANS, "read mux %p pos %d size: %d = %d\n",
314                  m, m->rpos, m->rsize, m->rsize-m->rpos);
315         err = p9_fd_read(m->client, m->rbuf + m->rpos,
316                                                 m->rsize - m->rpos);
317         p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
318         if (err == -EAGAIN) {
319                 goto end_clear;
320         }
321 
322         if (err <= 0)
323                 goto error;
324 
325         m->rpos += err;
326 
327         if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */
328                 u16 tag;
329                 p9_debug(P9_DEBUG_TRANS, "got new header\n");
330 
331                 n = le32_to_cpu(*(__le32 *) m->rbuf); /* read packet size */
332                 if (n >= m->client->msize) {
333                         p9_debug(P9_DEBUG_ERROR,
334                                  "requested packet size too big: %d\n", n);
335                         err = -EIO;
336                         goto error;
337                 }
338 
339                 tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */
340                 p9_debug(P9_DEBUG_TRANS,
341                          "mux %p pkt: size: %d bytes tag: %d\n", m, n, tag);
342 
343                 m->req = p9_tag_lookup(m->client, tag);
344                 if (!m->req || (m->req->status != REQ_STATUS_SENT &&
345                                         m->req->status != REQ_STATUS_FLSH)) {
346                         p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
347                                  tag);
348                         err = -EIO;
349                         goto error;
350                 }
351 
352                 if (m->req->rc == NULL) {
353                         m->req->rc = kmalloc(sizeof(struct p9_fcall) +
354                                                 m->client->msize, GFP_NOFS);
355                         if (!m->req->rc) {
356                                 m->req = NULL;
357                                 err = -ENOMEM;
358                                 goto error;
359                         }
360                 }
361                 m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);
362                 memcpy(m->rbuf, m->tmp_buf, m->rsize);
363                 m->rsize = n;
364         }
365 
366         /* not an else because some packets (like clunk) have no payload */
367         if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
368                 p9_debug(P9_DEBUG_TRANS, "got new packet\n");
369                 spin_lock(&m->client->lock);
370                 if (m->req->status != REQ_STATUS_ERROR)
371                         m->req->status = REQ_STATUS_RCVD;
372                 list_del(&m->req->req_list);
373                 spin_unlock(&m->client->lock);
374                 p9_client_cb(m->client, m->req);
375                 m->rbuf = NULL;
376                 m->rpos = 0;
377                 m->rsize = 0;
378                 m->req = NULL;
379         }
380 
381 end_clear:
382         clear_bit(Rworksched, &m->wsched);
383 
384         if (!list_empty(&m->req_list)) {
385                 if (test_and_clear_bit(Rpending, &m->wsched))
386                         n = POLLIN;
387                 else
388                         n = p9_fd_poll(m->client, NULL);
389 
390                 if ((n & POLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) {
391                         p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
392                         schedule_work(&m->rq);
393                 }
394         }
395 
396         return;
397 error:
398         p9_conn_cancel(m, err);
399         clear_bit(Rworksched, &m->wsched);
400 }
401 
402 /**
403  * p9_fd_write - write to a socket
404  * @client: client instance
405  * @v: buffer to send data from
406  * @len: size of send buffer
407  *
408  */
409 
410 static int p9_fd_write(struct p9_client *client, void *v, int len)
411 {
412         int ret;
413         mm_segment_t oldfs;
414         struct p9_trans_fd *ts = NULL;
415 
416         if (client && client->status != Disconnected)
417                 ts = client->trans;
418 
419         if (!ts)
420                 return -EREMOTEIO;
421 
422         if (!(ts->wr->f_flags & O_NONBLOCK))
423                 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
424 
425         oldfs = get_fs();
426         set_fs(get_ds());
427         /* The cast to a user pointer is valid due to the set_fs() */
428         ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos);
429         set_fs(oldfs);
430 
431         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
432                 client->status = Disconnected;
433         return ret;
434 }
435 
436 /**
437  * p9_write_work - called when a transport can send some data
438  * @work: container for work to be done
439  *
440  */
441 
442 static void p9_write_work(struct work_struct *work)
443 {
444         int n, err;
445         struct p9_conn *m;
446         struct p9_req_t *req;
447 
448         m = container_of(work, struct p9_conn, wq);
449 
450         if (m->err < 0) {
451                 clear_bit(Wworksched, &m->wsched);
452                 return;
453         }
454 
455         if (!m->wsize) {
456                 spin_lock(&m->client->lock);
457                 if (list_empty(&m->unsent_req_list)) {
458                         clear_bit(Wworksched, &m->wsched);
459                         spin_unlock(&m->client->lock);
460                         return;
461                 }
462 
463                 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
464                                req_list);
465                 req->status = REQ_STATUS_SENT;
466                 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
467                 list_move_tail(&req->req_list, &m->req_list);
468 
469                 m->wbuf = req->tc->sdata;
470                 m->wsize = req->tc->size;
471                 m->wpos = 0;
472                 spin_unlock(&m->client->lock);
473         }
474 
475         p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n",
476                  m, m->wpos, m->wsize);
477         clear_bit(Wpending, &m->wsched);
478         err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
479         p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
480         if (err == -EAGAIN)
481                 goto end_clear;
482 
483 
484         if (err < 0)
485                 goto error;
486         else if (err == 0) {
487                 err = -EREMOTEIO;
488                 goto error;
489         }
490 
491         m->wpos += err;
492         if (m->wpos == m->wsize)
493                 m->wpos = m->wsize = 0;
494 
495 end_clear:
496         clear_bit(Wworksched, &m->wsched);
497 
498         if (m->wsize || !list_empty(&m->unsent_req_list)) {
499                 if (test_and_clear_bit(Wpending, &m->wsched))
500                         n = POLLOUT;
501                 else
502                         n = p9_fd_poll(m->client, NULL);
503 
504                 if ((n & POLLOUT) &&
505                    !test_and_set_bit(Wworksched, &m->wsched)) {
506                         p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
507                         schedule_work(&m->wq);
508                 }
509         }
510 
511         return;
512 
513 error:
514         p9_conn_cancel(m, err);
515         clear_bit(Wworksched, &m->wsched);
516 }
517 
518 static int p9_pollwake(wait_queue_t *wait, unsigned int mode, int sync, void *key)
519 {
520         struct p9_poll_wait *pwait =
521                 container_of(wait, struct p9_poll_wait, wait);
522         struct p9_conn *m = pwait->conn;
523         unsigned long flags;
524 
525         spin_lock_irqsave(&p9_poll_lock, flags);
526         if (list_empty(&m->poll_pending_link))
527                 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
528         spin_unlock_irqrestore(&p9_poll_lock, flags);
529 
530         schedule_work(&p9_poll_work);
531         return 1;
532 }
533 
534 /**
535  * p9_pollwait - add poll task to the wait queue
536  * @filp: file pointer being polled
537  * @wait_address: wait_q to block on
538  * @p: poll state
539  *
540  * called by files poll operation to add v9fs-poll task to files wait queue
541  */
542 
543 static void
544 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
545 {
546         struct p9_conn *m = container_of(p, struct p9_conn, pt);
547         struct p9_poll_wait *pwait = NULL;
548         int i;
549 
550         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
551                 if (m->poll_wait[i].wait_addr == NULL) {
552                         pwait = &m->poll_wait[i];
553                         break;
554                 }
555         }
556 
557         if (!pwait) {
558                 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n");
559                 return;
560         }
561 
562         pwait->conn = m;
563         pwait->wait_addr = wait_address;
564         init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
565         add_wait_queue(wait_address, &pwait->wait);
566 }
567 
568 /**
569  * p9_conn_create - allocate and initialize the per-session mux data
570  * @client: client instance
571  *
572  * Note: Creates the polling task if this is the first session.
573  */
574 
575 static struct p9_conn *p9_conn_create(struct p9_client *client)
576 {
577         int n;
578         struct p9_conn *m;
579 
580         p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
581         m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
582         if (!m)
583                 return ERR_PTR(-ENOMEM);
584 
585         INIT_LIST_HEAD(&m->mux_list);
586         m->client = client;
587 
588         INIT_LIST_HEAD(&m->req_list);
589         INIT_LIST_HEAD(&m->unsent_req_list);
590         INIT_WORK(&m->rq, p9_read_work);
591         INIT_WORK(&m->wq, p9_write_work);
592         INIT_LIST_HEAD(&m->poll_pending_link);
593         init_poll_funcptr(&m->pt, p9_pollwait);
594 
595         n = p9_fd_poll(client, &m->pt);
596         if (n & POLLIN) {
597                 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
598                 set_bit(Rpending, &m->wsched);
599         }
600 
601         if (n & POLLOUT) {
602                 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
603                 set_bit(Wpending, &m->wsched);
604         }
605 
606         return m;
607 }
608 
609 /**
610  * p9_poll_mux - polls a mux and schedules read or write works if necessary
611  * @m: connection to poll
612  *
613  */
614 
615 static void p9_poll_mux(struct p9_conn *m)
616 {
617         int n;
618 
619         if (m->err < 0)
620                 return;
621 
622         n = p9_fd_poll(m->client, NULL);
623         if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
624                 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
625                 if (n >= 0)
626                         n = -ECONNRESET;
627                 p9_conn_cancel(m, n);
628         }
629 
630         if (n & POLLIN) {
631                 set_bit(Rpending, &m->wsched);
632                 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
633                 if (!test_and_set_bit(Rworksched, &m->wsched)) {
634                         p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
635                         schedule_work(&m->rq);
636                 }
637         }
638 
639         if (n & POLLOUT) {
640                 set_bit(Wpending, &m->wsched);
641                 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
642                 if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
643                     !test_and_set_bit(Wworksched, &m->wsched)) {
644                         p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
645                         schedule_work(&m->wq);
646                 }
647         }
648 }
649 
650 /**
651  * p9_fd_request - send 9P request
652  * The function can sleep until the request is scheduled for sending.
653  * The function can be interrupted. Return from the function is not
654  * a guarantee that the request is sent successfully.
655  *
656  * @client: client instance
657  * @req: request to be sent
658  *
659  */
660 
661 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
662 {
663         int n;
664         struct p9_trans_fd *ts = client->trans;
665         struct p9_conn *m = ts->conn;
666 
667         p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
668                  m, current, req->tc, req->tc->id);
669         if (m->err < 0)
670                 return m->err;
671 
672         spin_lock(&client->lock);
673         req->status = REQ_STATUS_UNSENT;
674         list_add_tail(&req->req_list, &m->unsent_req_list);
675         spin_unlock(&client->lock);
676 
677         if (test_and_clear_bit(Wpending, &m->wsched))
678                 n = POLLOUT;
679         else
680                 n = p9_fd_poll(m->client, NULL);
681 
682         if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
683                 schedule_work(&m->wq);
684 
685         return 0;
686 }
687 
688 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
689 {
690         int ret = 1;
691 
692         p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
693 
694         spin_lock(&client->lock);
695 
696         if (req->status == REQ_STATUS_UNSENT) {
697                 list_del(&req->req_list);
698                 req->status = REQ_STATUS_FLSHD;
699                 ret = 0;
700         } else if (req->status == REQ_STATUS_SENT)
701                 req->status = REQ_STATUS_FLSH;
702 
703         spin_unlock(&client->lock);
704 
705         return ret;
706 }
707 
708 /**
709  * parse_opts - parse mount options into p9_fd_opts structure
710  * @params: options string passed from mount
711  * @opts: fd transport-specific structure to parse options into
712  *
713  * Returns 0 upon success, -ERRNO upon failure
714  */
715 
716 static int parse_opts(char *params, struct p9_fd_opts *opts)
717 {
718         char *p;
719         substring_t args[MAX_OPT_ARGS];
720         int option;
721         char *options, *tmp_options;
722 
723         opts->port = P9_PORT;
724         opts->rfd = ~0;
725         opts->wfd = ~0;
726 
727         if (!params)
728                 return 0;
729 
730         tmp_options = kstrdup(params, GFP_KERNEL);
731         if (!tmp_options) {
732                 p9_debug(P9_DEBUG_ERROR,
733                          "failed to allocate copy of option string\n");
734                 return -ENOMEM;
735         }
736         options = tmp_options;
737 
738         while ((p = strsep(&options, ",")) != NULL) {
739                 int token;
740                 int r;
741                 if (!*p)
742                         continue;
743                 token = match_token(p, tokens, args);
744                 if (token != Opt_err) {
745                         r = match_int(&args[0], &option);
746                         if (r < 0) {
747                                 p9_debug(P9_DEBUG_ERROR,
748                                          "integer field, but no integer?\n");
749                                 continue;
750                         }
751                 }
752                 switch (token) {
753                 case Opt_port:
754                         opts->port = option;
755                         break;
756                 case Opt_rfdno:
757                         opts->rfd = option;
758                         break;
759                 case Opt_wfdno:
760                         opts->wfd = option;
761                         break;
762                 default:
763                         continue;
764                 }
765         }
766 
767         kfree(tmp_options);
768         return 0;
769 }
770 
771 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
772 {
773         struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
774                                            GFP_KERNEL);
775         if (!ts)
776                 return -ENOMEM;
777 
778         ts->rd = fget(rfd);
779         ts->wr = fget(wfd);
780         if (!ts->rd || !ts->wr) {
781                 if (ts->rd)
782                         fput(ts->rd);
783                 if (ts->wr)
784                         fput(ts->wr);
785                 kfree(ts);
786                 return -EIO;
787         }
788 
789         client->trans = ts;
790         client->status = Connected;
791 
792         return 0;
793 }
794 
795 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
796 {
797         struct p9_trans_fd *p;
798         struct file *file;
799         int ret;
800 
801         p = kmalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
802         if (!p)
803                 return -ENOMEM;
804 
805         csocket->sk->sk_allocation = GFP_NOIO;
806         file = sock_alloc_file(csocket, 0, NULL);
807         if (IS_ERR(file)) {
808                 pr_err("%s (%d): failed to map fd\n",
809                        __func__, task_pid_nr(current));
810                 sock_release(csocket);
811                 kfree(p);
812                 return PTR_ERR(file);
813         }
814 
815         get_file(file);
816         p->wr = p->rd = file;
817         client->trans = p;
818         client->status = Connected;
819 
820         p->rd->f_flags |= O_NONBLOCK;
821 
822         p->conn = p9_conn_create(client);
823         if (IS_ERR(p->conn)) {
824                 ret = PTR_ERR(p->conn);
825                 p->conn = NULL;
826                 kfree(p);
827                 sockfd_put(csocket);
828                 sockfd_put(csocket);
829                 return ret;
830         }
831         return 0;
832 }
833 
834 /**
835  * p9_mux_destroy - cancels all pending requests and frees mux resources
836  * @m: mux to destroy
837  *
838  */
839 
840 static void p9_conn_destroy(struct p9_conn *m)
841 {
842         p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n",
843                  m, m->mux_list.prev, m->mux_list.next);
844 
845         p9_mux_poll_stop(m);
846         cancel_work_sync(&m->rq);
847         cancel_work_sync(&m->wq);
848 
849         p9_conn_cancel(m, -ECONNRESET);
850 
851         m->client = NULL;
852         kfree(m);
853 }
854 
855 /**
856  * p9_fd_close - shutdown file descriptor transport
857  * @client: client instance
858  *
859  */
860 
861 static void p9_fd_close(struct p9_client *client)
862 {
863         struct p9_trans_fd *ts;
864 
865         if (!client)
866                 return;
867 
868         ts = client->trans;
869         if (!ts)
870                 return;
871 
872         client->status = Disconnected;
873 
874         p9_conn_destroy(ts->conn);
875 
876         if (ts->rd)
877                 fput(ts->rd);
878         if (ts->wr)
879                 fput(ts->wr);
880 
881         kfree(ts);
882 }
883 
884 /*
885  * stolen from NFS - maybe should be made a generic function?
886  */
887 static inline int valid_ipaddr4(const char *buf)
888 {
889         int rc, count, in[4];
890 
891         rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
892         if (rc != 4)
893                 return -EINVAL;
894         for (count = 0; count < 4; count++) {
895                 if (in[count] > 255)
896                         return -EINVAL;
897         }
898         return 0;
899 }
900 
901 static int
902 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
903 {
904         int err;
905         struct socket *csocket;
906         struct sockaddr_in sin_server;
907         struct p9_fd_opts opts;
908 
909         err = parse_opts(args, &opts);
910         if (err < 0)
911                 return err;
912 
913         if (valid_ipaddr4(addr) < 0)
914                 return -EINVAL;
915 
916         csocket = NULL;
917 
918         sin_server.sin_family = AF_INET;
919         sin_server.sin_addr.s_addr = in_aton(addr);
920         sin_server.sin_port = htons(opts.port);
921         err = __sock_create(read_pnet(&current->nsproxy->net_ns), PF_INET,
922                             SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
923         if (err) {
924                 pr_err("%s (%d): problem creating socket\n",
925                        __func__, task_pid_nr(current));
926                 return err;
927         }
928 
929         err = csocket->ops->connect(csocket,
930                                     (struct sockaddr *)&sin_server,
931                                     sizeof(struct sockaddr_in), 0);
932         if (err < 0) {
933                 pr_err("%s (%d): problem connecting socket to %s\n",
934                        __func__, task_pid_nr(current), addr);
935                 sock_release(csocket);
936                 return err;
937         }
938 
939         return p9_socket_open(client, csocket);
940 }
941 
942 static int
943 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
944 {
945         int err;
946         struct socket *csocket;
947         struct sockaddr_un sun_server;
948 
949         csocket = NULL;
950 
951         if (strlen(addr) >= UNIX_PATH_MAX) {
952                 pr_err("%s (%d): address too long: %s\n",
953                        __func__, task_pid_nr(current), addr);
954                 return -ENAMETOOLONG;
955         }
956 
957         sun_server.sun_family = PF_UNIX;
958         strcpy(sun_server.sun_path, addr);
959         err = __sock_create(read_pnet(&current->nsproxy->net_ns), PF_UNIX,
960                             SOCK_STREAM, 0, &csocket, 1);
961         if (err < 0) {
962                 pr_err("%s (%d): problem creating socket\n",
963                        __func__, task_pid_nr(current));
964 
965                 return err;
966         }
967         err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
968                         sizeof(struct sockaddr_un) - 1, 0);
969         if (err < 0) {
970                 pr_err("%s (%d): problem connecting socket: %s: %d\n",
971                        __func__, task_pid_nr(current), addr, err);
972                 sock_release(csocket);
973                 return err;
974         }
975 
976         return p9_socket_open(client, csocket);
977 }
978 
979 static int
980 p9_fd_create(struct p9_client *client, const char *addr, char *args)
981 {
982         int err;
983         struct p9_fd_opts opts;
984         struct p9_trans_fd *p;
985 
986         parse_opts(args, &opts);
987 
988         if (opts.rfd == ~0 || opts.wfd == ~0) {
989                 pr_err("Insufficient options for proto=fd\n");
990                 return -ENOPROTOOPT;
991         }
992 
993         err = p9_fd_open(client, opts.rfd, opts.wfd);
994         if (err < 0)
995                 return err;
996 
997         p = (struct p9_trans_fd *) client->trans;
998         p->conn = p9_conn_create(client);
999         if (IS_ERR(p->conn)) {
1000                 err = PTR_ERR(p->conn);
1001                 p->conn = NULL;
1002                 fput(p->rd);
1003                 fput(p->wr);
1004                 return err;
1005         }
1006 
1007         return 0;
1008 }
1009 
1010 static struct p9_trans_module p9_tcp_trans = {
1011         .name = "tcp",
1012         .maxsize = MAX_SOCK_BUF,
1013         .def = 1,
1014         .create = p9_fd_create_tcp,
1015         .close = p9_fd_close,
1016         .request = p9_fd_request,
1017         .cancel = p9_fd_cancel,
1018         .owner = THIS_MODULE,
1019 };
1020 
1021 static struct p9_trans_module p9_unix_trans = {
1022         .name = "unix",
1023         .maxsize = MAX_SOCK_BUF,
1024         .def = 0,
1025         .create = p9_fd_create_unix,
1026         .close = p9_fd_close,
1027         .request = p9_fd_request,
1028         .cancel = p9_fd_cancel,
1029         .owner = THIS_MODULE,
1030 };
1031 
1032 static struct p9_trans_module p9_fd_trans = {
1033         .name = "fd",
1034         .maxsize = MAX_SOCK_BUF,
1035         .def = 0,
1036         .create = p9_fd_create,
1037         .close = p9_fd_close,
1038         .request = p9_fd_request,
1039         .cancel = p9_fd_cancel,
1040         .owner = THIS_MODULE,
1041 };
1042 
1043 /**
1044  * p9_poll_proc - poll worker thread
1045  * @a: thread state and arguments
1046  *
1047  * polls all v9fs transports for new events and queues the appropriate
1048  * work to the work queue
1049  *
1050  */
1051 
1052 static void p9_poll_workfn(struct work_struct *work)
1053 {
1054         unsigned long flags;
1055 
1056         p9_debug(P9_DEBUG_TRANS, "start %p\n", current);
1057 
1058         spin_lock_irqsave(&p9_poll_lock, flags);
1059         while (!list_empty(&p9_poll_pending_list)) {
1060                 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1061                                                         struct p9_conn,
1062                                                         poll_pending_link);
1063                 list_del_init(&conn->poll_pending_link);
1064                 spin_unlock_irqrestore(&p9_poll_lock, flags);
1065 
1066                 p9_poll_mux(conn);
1067 
1068                 spin_lock_irqsave(&p9_poll_lock, flags);
1069         }
1070         spin_unlock_irqrestore(&p9_poll_lock, flags);
1071 
1072         p9_debug(P9_DEBUG_TRANS, "finish\n");
1073 }
1074 
1075 int p9_trans_fd_init(void)
1076 {
1077         v9fs_register_trans(&p9_tcp_trans);
1078         v9fs_register_trans(&p9_unix_trans);
1079         v9fs_register_trans(&p9_fd_trans);
1080 
1081         return 0;
1082 }
1083 
1084 void p9_trans_fd_exit(void)
1085 {
1086         flush_work(&p9_poll_work);
1087         v9fs_unregister_trans(&p9_tcp_trans);
1088         v9fs_unregister_trans(&p9_unix_trans);
1089         v9fs_unregister_trans(&p9_fd_trans);
1090 }
1091 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp