Commit | Line | Data |
---|---|---|
426cc91a EVH |
1 | /* |
2 | * linux/fs/9p/mux.c | |
3 | * | |
4 | * Protocol Multiplexer | |
5 | * | |
6 | * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> | |
3cf6429a | 7 | * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net> |
426cc91a EVH |
8 | * |
9 | * This program is free software; you can redistribute it and/or modify | |
42e8c509 EVH |
10 | * it under the terms of the GNU General Public License version 2 |
11 | * as published by the Free Software Foundation. | |
426cc91a EVH |
12 | * |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to: | |
20 | * Free Software Foundation | |
21 | * 51 Franklin Street, Fifth Floor | |
22 | * Boston, MA 02111-1301 USA | |
23 | * | |
24 | */ | |
25 | ||
426cc91a EVH |
26 | #include <linux/module.h> |
27 | #include <linux/errno.h> | |
28 | #include <linux/fs.h> | |
3cf6429a | 29 | #include <linux/poll.h> |
426cc91a EVH |
30 | #include <linux/kthread.h> |
31 | #include <linux/idr.h> | |
4f7a07b8 | 32 | #include <linux/mutex.h> |
426cc91a EVH |
33 | |
34 | #include "debug.h" | |
35 | #include "v9fs.h" | |
36 | #include "9p.h" | |
426cc91a | 37 | #include "conv.h" |
531b1094 | 38 | #include "transport.h" |
426cc91a EVH |
39 | #include "mux.h" |
40 | ||
3cf6429a LI |
41 | #define ERREQFLUSH 1 |
42 | #define SCHED_TIMEOUT 10 | |
43 | #define MAXPOLLWADDR 2 | |
44 | ||
45 | enum { | |
46 | Rworksched = 1, /* read work scheduled or running */ | |
47 | Rpending = 2, /* can read */ | |
48 | Wworksched = 4, /* write work scheduled or running */ | |
49 | Wpending = 8, /* can write */ | |
50 | }; | |
51 | ||
41e5a6ac LI |
52 | enum { |
53 | None, | |
54 | Flushing, | |
55 | Flushed, | |
56 | }; | |
57 | ||
3cf6429a LI |
58 | struct v9fs_mux_poll_task; |
59 | ||
60 | struct v9fs_req { | |
41e5a6ac | 61 | spinlock_t lock; |
3cf6429a LI |
62 | int tag; |
63 | struct v9fs_fcall *tcall; | |
64 | struct v9fs_fcall *rcall; | |
65 | int err; | |
66 | v9fs_mux_req_callback cb; | |
67 | void *cba; | |
41e5a6ac | 68 | int flush; |
3cf6429a LI |
69 | struct list_head req_list; |
70 | }; | |
71 | ||
72 | struct v9fs_mux_data { | |
73 | spinlock_t lock; | |
74 | struct list_head mux_list; | |
75 | struct v9fs_mux_poll_task *poll_task; | |
76 | int msize; | |
77 | unsigned char *extended; | |
78 | struct v9fs_transport *trans; | |
4a26c242 | 79 | struct v9fs_idpool tagpool; |
3cf6429a LI |
80 | int err; |
81 | wait_queue_head_t equeue; | |
82 | struct list_head req_list; | |
83 | struct list_head unsent_req_list; | |
531b1094 | 84 | struct v9fs_fcall *rcall; |
3cf6429a LI |
85 | int rpos; |
86 | char *rbuf; | |
87 | int wpos; | |
88 | int wsize; | |
89 | char *wbuf; | |
90 | wait_queue_t poll_wait[MAXPOLLWADDR]; | |
91 | wait_queue_head_t *poll_waddr[MAXPOLLWADDR]; | |
92 | poll_table pt; | |
93 | struct work_struct rq; | |
94 | struct work_struct wq; | |
95 | unsigned long wsched; | |
96 | }; | |
97 | ||
98 | struct v9fs_mux_poll_task { | |
99 | struct task_struct *task; | |
100 | struct list_head mux_list; | |
101 | int muxnum; | |
102 | }; | |
103 | ||
104 | struct v9fs_mux_rpc { | |
105 | struct v9fs_mux_data *m; | |
3cf6429a | 106 | int err; |
41e5a6ac | 107 | struct v9fs_fcall *tcall; |
3cf6429a LI |
108 | struct v9fs_fcall *rcall; |
109 | wait_queue_head_t wqueue; | |
110 | }; | |
111 | ||
112 | static int v9fs_poll_proc(void *); | |
113 | static void v9fs_read_work(void *); | |
114 | static void v9fs_write_work(void *); | |
115 | static void v9fs_pollwait(struct file *filp, wait_queue_head_t * wait_address, | |
116 | poll_table * p); | |
531b1094 LI |
117 | static u16 v9fs_mux_get_tag(struct v9fs_mux_data *); |
118 | static void v9fs_mux_put_tag(struct v9fs_mux_data *, u16); | |
3cf6429a | 119 | |
4f7a07b8 | 120 | static DEFINE_MUTEX(v9fs_mux_task_lock); |
3cf6429a LI |
121 | static struct workqueue_struct *v9fs_mux_wq; |
122 | ||
123 | static int v9fs_mux_num; | |
124 | static int v9fs_mux_poll_task_num; | |
125 | static struct v9fs_mux_poll_task v9fs_mux_poll_tasks[100]; | |
126 | ||
1dac06b2 | 127 | int v9fs_mux_global_init(void) |
3cf6429a LI |
128 | { |
129 | int i; | |
130 | ||
131 | for (i = 0; i < ARRAY_SIZE(v9fs_mux_poll_tasks); i++) | |
132 | v9fs_mux_poll_tasks[i].task = NULL; | |
133 | ||
134 | v9fs_mux_wq = create_workqueue("v9fs"); | |
1dac06b2 LI |
135 | if (!v9fs_mux_wq) |
136 | return -ENOMEM; | |
137 | ||
138 | return 0; | |
3cf6429a | 139 | } |
426cc91a | 140 | |
3cf6429a | 141 | void v9fs_mux_global_exit(void) |
426cc91a | 142 | { |
3cf6429a | 143 | destroy_workqueue(v9fs_mux_wq); |
426cc91a EVH |
144 | } |
145 | ||
146 | /** | |
3cf6429a LI |
147 | * v9fs_mux_calc_poll_procs - calculates the number of polling procs |
148 | * based on the number of mounted v9fs filesystems. | |
426cc91a | 149 | * |
3cf6429a | 150 | * The current implementation returns sqrt of the number of mounts. |
426cc91a | 151 | */ |
29c6e486 | 152 | static int v9fs_mux_calc_poll_procs(int muxnum) |
3cf6429a LI |
153 | { |
154 | int n; | |
155 | ||
156 | if (v9fs_mux_poll_task_num) | |
157 | n = muxnum / v9fs_mux_poll_task_num + | |
158 | (muxnum % v9fs_mux_poll_task_num ? 1 : 0); | |
159 | else | |
160 | n = 1; | |
161 | ||
162 | if (n > ARRAY_SIZE(v9fs_mux_poll_tasks)) | |
163 | n = ARRAY_SIZE(v9fs_mux_poll_tasks); | |
426cc91a | 164 | |
3cf6429a LI |
165 | return n; |
166 | } | |
167 | ||
1dac06b2 | 168 | static int v9fs_mux_poll_start(struct v9fs_mux_data *m) |
426cc91a | 169 | { |
3cf6429a LI |
170 | int i, n; |
171 | struct v9fs_mux_poll_task *vpt, *vptlast; | |
1dac06b2 | 172 | struct task_struct *pproc; |
3cf6429a LI |
173 | |
174 | dprintk(DEBUG_MUX, "mux %p muxnum %d procnum %d\n", m, v9fs_mux_num, | |
175 | v9fs_mux_poll_task_num); | |
4f7a07b8 | 176 | mutex_lock(&v9fs_mux_task_lock); |
3cf6429a LI |
177 | |
178 | n = v9fs_mux_calc_poll_procs(v9fs_mux_num + 1); | |
179 | if (n > v9fs_mux_poll_task_num) { | |
180 | for (i = 0; i < ARRAY_SIZE(v9fs_mux_poll_tasks); i++) { | |
181 | if (v9fs_mux_poll_tasks[i].task == NULL) { | |
182 | vpt = &v9fs_mux_poll_tasks[i]; | |
183 | dprintk(DEBUG_MUX, "create proc %p\n", vpt); | |
1dac06b2 | 184 | pproc = kthread_create(v9fs_poll_proc, vpt, |
531b1094 | 185 | "v9fs-poll"); |
1dac06b2 LI |
186 | |
187 | if (!IS_ERR(pproc)) { | |
188 | vpt->task = pproc; | |
189 | INIT_LIST_HEAD(&vpt->mux_list); | |
190 | vpt->muxnum = 0; | |
191 | v9fs_mux_poll_task_num++; | |
192 | wake_up_process(vpt->task); | |
193 | } | |
3cf6429a LI |
194 | break; |
195 | } | |
426cc91a | 196 | } |
426cc91a | 197 | |
3cf6429a LI |
198 | if (i >= ARRAY_SIZE(v9fs_mux_poll_tasks)) |
199 | dprintk(DEBUG_ERROR, "warning: no free poll slots\n"); | |
200 | } | |
426cc91a | 201 | |
3cf6429a LI |
202 | n = (v9fs_mux_num + 1) / v9fs_mux_poll_task_num + |
203 | ((v9fs_mux_num + 1) % v9fs_mux_poll_task_num ? 1 : 0); | |
204 | ||
205 | vptlast = NULL; | |
206 | for (i = 0; i < ARRAY_SIZE(v9fs_mux_poll_tasks); i++) { | |
207 | vpt = &v9fs_mux_poll_tasks[i]; | |
208 | if (vpt->task != NULL) { | |
209 | vptlast = vpt; | |
210 | if (vpt->muxnum < n) { | |
211 | dprintk(DEBUG_MUX, "put in proc %d\n", i); | |
212 | list_add(&m->mux_list, &vpt->mux_list); | |
213 | vpt->muxnum++; | |
214 | m->poll_task = vpt; | |
215 | memset(&m->poll_waddr, 0, sizeof(m->poll_waddr)); | |
216 | init_poll_funcptr(&m->pt, v9fs_pollwait); | |
217 | break; | |
218 | } | |
219 | } | |
426cc91a EVH |
220 | } |
221 | ||
3cf6429a | 222 | if (i >= ARRAY_SIZE(v9fs_mux_poll_tasks)) { |
1dac06b2 LI |
223 | if (vptlast == NULL) |
224 | return -ENOMEM; | |
225 | ||
3cf6429a LI |
226 | dprintk(DEBUG_MUX, "put in proc %d\n", i); |
227 | list_add(&m->mux_list, &vptlast->mux_list); | |
228 | vptlast->muxnum++; | |
1dac06b2 | 229 | m->poll_task = vptlast; |
3cf6429a LI |
230 | memset(&m->poll_waddr, 0, sizeof(m->poll_waddr)); |
231 | init_poll_funcptr(&m->pt, v9fs_pollwait); | |
426cc91a EVH |
232 | } |
233 | ||
3cf6429a | 234 | v9fs_mux_num++; |
4f7a07b8 | 235 | mutex_unlock(&v9fs_mux_task_lock); |
1dac06b2 LI |
236 | |
237 | return 0; | |
3cf6429a | 238 | } |
426cc91a | 239 | |
3cf6429a LI |
240 | static void v9fs_mux_poll_stop(struct v9fs_mux_data *m) |
241 | { | |
242 | int i; | |
243 | struct v9fs_mux_poll_task *vpt; | |
244 | ||
4f7a07b8 | 245 | mutex_lock(&v9fs_mux_task_lock); |
3cf6429a LI |
246 | vpt = m->poll_task; |
247 | list_del(&m->mux_list); | |
248 | for(i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) { | |
249 | if (m->poll_waddr[i] != NULL) { | |
250 | remove_wait_queue(m->poll_waddr[i], &m->poll_wait[i]); | |
251 | m->poll_waddr[i] = NULL; | |
252 | } | |
253 | } | |
254 | vpt->muxnum--; | |
255 | if (!vpt->muxnum) { | |
256 | dprintk(DEBUG_MUX, "destroy proc %p\n", vpt); | |
257 | send_sig(SIGKILL, vpt->task, 1); | |
258 | vpt->task = NULL; | |
259 | v9fs_mux_poll_task_num--; | |
260 | } | |
261 | v9fs_mux_num--; | |
4f7a07b8 | 262 | mutex_unlock(&v9fs_mux_task_lock); |
3cf6429a | 263 | } |
426cc91a | 264 | |
3cf6429a LI |
265 | /** |
266 | * v9fs_mux_init - allocate and initialize the per-session mux data | |
267 | * Creates the polling task if this is the first session. | |
268 | * | |
269 | * @trans - transport structure | |
270 | * @msize - maximum message size | |
271 | * @extended - pointer to the extended flag | |
272 | */ | |
273 | struct v9fs_mux_data *v9fs_mux_init(struct v9fs_transport *trans, int msize, | |
274 | unsigned char *extended) | |
275 | { | |
276 | int i, n; | |
277 | struct v9fs_mux_data *m, *mtmp; | |
278 | ||
279 | dprintk(DEBUG_MUX, "transport %p msize %d\n", trans, msize); | |
531b1094 | 280 | m = kmalloc(sizeof(struct v9fs_mux_data), GFP_KERNEL); |
3cf6429a LI |
281 | if (!m) |
282 | return ERR_PTR(-ENOMEM); | |
283 | ||
284 | spin_lock_init(&m->lock); | |
285 | INIT_LIST_HEAD(&m->mux_list); | |
286 | m->msize = msize; | |
287 | m->extended = extended; | |
288 | m->trans = trans; | |
4a26c242 RC |
289 | idr_init(&m->tagpool.pool); |
290 | init_MUTEX(&m->tagpool.lock); | |
3cf6429a LI |
291 | m->err = 0; |
292 | init_waitqueue_head(&m->equeue); | |
293 | INIT_LIST_HEAD(&m->req_list); | |
294 | INIT_LIST_HEAD(&m->unsent_req_list); | |
531b1094 | 295 | m->rcall = NULL; |
3cf6429a | 296 | m->rpos = 0; |
531b1094 | 297 | m->rbuf = NULL; |
3cf6429a | 298 | m->wpos = m->wsize = 0; |
531b1094 | 299 | m->wbuf = NULL; |
3cf6429a LI |
300 | INIT_WORK(&m->rq, v9fs_read_work, m); |
301 | INIT_WORK(&m->wq, v9fs_write_work, m); | |
302 | m->wsched = 0; | |
303 | memset(&m->poll_waddr, 0, sizeof(m->poll_waddr)); | |
1dac06b2 LI |
304 | m->poll_task = NULL; |
305 | n = v9fs_mux_poll_start(m); | |
306 | if (n) | |
307 | return ERR_PTR(n); | |
3cf6429a LI |
308 | |
309 | n = trans->poll(trans, &m->pt); | |
310 | if (n & POLLIN) { | |
311 | dprintk(DEBUG_MUX, "mux %p can read\n", m); | |
312 | set_bit(Rpending, &m->wsched); | |
426cc91a EVH |
313 | } |
314 | ||
3cf6429a LI |
315 | if (n & POLLOUT) { |
316 | dprintk(DEBUG_MUX, "mux %p can write\n", m); | |
317 | set_bit(Wpending, &m->wsched); | |
426cc91a EVH |
318 | } |
319 | ||
3cf6429a LI |
320 | for(i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) { |
321 | if (IS_ERR(m->poll_waddr[i])) { | |
322 | v9fs_mux_poll_stop(m); | |
323 | mtmp = (void *)m->poll_waddr; /* the error code */ | |
324 | kfree(m); | |
325 | m = mtmp; | |
326 | break; | |
327 | } | |
426cc91a EVH |
328 | } |
329 | ||
3cf6429a LI |
330 | return m; |
331 | } | |
426cc91a | 332 | |
3cf6429a LI |
333 | /** |
334 | * v9fs_mux_destroy - cancels all pending requests and frees mux resources | |
335 | */ | |
336 | void v9fs_mux_destroy(struct v9fs_mux_data *m) | |
337 | { | |
338 | dprintk(DEBUG_MUX, "mux %p prev %p next %p\n", m, | |
339 | m->mux_list.prev, m->mux_list.next); | |
340 | v9fs_mux_cancel(m, -ECONNRESET); | |
341 | ||
342 | if (!list_empty(&m->req_list)) { | |
343 | /* wait until all processes waiting on this session exit */ | |
344 | dprintk(DEBUG_MUX, "mux %p waiting for empty request queue\n", | |
345 | m); | |
346 | wait_event_timeout(m->equeue, (list_empty(&m->req_list)), 5000); | |
347 | dprintk(DEBUG_MUX, "mux %p request queue empty: %d\n", m, | |
348 | list_empty(&m->req_list)); | |
349 | } | |
426cc91a | 350 | |
3cf6429a LI |
351 | v9fs_mux_poll_stop(m); |
352 | m->trans = NULL; | |
426cc91a | 353 | |
3cf6429a | 354 | kfree(m); |
426cc91a EVH |
355 | } |
356 | ||
357 | /** | |
3cf6429a LI |
358 | * v9fs_pollwait - called by files poll operation to add v9fs-poll task |
359 | * to files wait queue | |
426cc91a | 360 | */ |
3cf6429a LI |
361 | static void |
362 | v9fs_pollwait(struct file *filp, wait_queue_head_t * wait_address, | |
363 | poll_table * p) | |
426cc91a | 364 | { |
3cf6429a LI |
365 | int i; |
366 | struct v9fs_mux_data *m; | |
426cc91a | 367 | |
3cf6429a LI |
368 | m = container_of(p, struct v9fs_mux_data, pt); |
369 | for(i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) | |
370 | if (m->poll_waddr[i] == NULL) | |
371 | break; | |
cb2e87a6 | 372 | |
3cf6429a LI |
373 | if (i >= ARRAY_SIZE(m->poll_waddr)) { |
374 | dprintk(DEBUG_ERROR, "not enough wait_address slots\n"); | |
375 | return; | |
376 | } | |
cb2e87a6 | 377 | |
3cf6429a | 378 | m->poll_waddr[i] = wait_address; |
cb2e87a6 | 379 | |
3cf6429a LI |
380 | if (!wait_address) { |
381 | dprintk(DEBUG_ERROR, "no wait_address\n"); | |
382 | m->poll_waddr[i] = ERR_PTR(-EIO); | |
383 | return; | |
384 | } | |
426cc91a | 385 | |
3cf6429a LI |
386 | init_waitqueue_entry(&m->poll_wait[i], m->poll_task->task); |
387 | add_wait_queue(wait_address, &m->poll_wait[i]); | |
426cc91a EVH |
388 | } |
389 | ||
390 | /** | |
3cf6429a | 391 | * v9fs_poll_mux - polls a mux and schedules read or write works if necessary |
426cc91a | 392 | */ |
29c6e486 | 393 | static void v9fs_poll_mux(struct v9fs_mux_data *m) |
426cc91a | 394 | { |
3cf6429a | 395 | int n; |
426cc91a | 396 | |
3cf6429a LI |
397 | if (m->err < 0) |
398 | return; | |
399 | ||
400 | n = m->trans->poll(m->trans, NULL); | |
401 | if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) { | |
402 | dprintk(DEBUG_MUX, "error mux %p err %d\n", m, n); | |
403 | if (n >= 0) | |
404 | n = -ECONNRESET; | |
405 | v9fs_mux_cancel(m, n); | |
406 | } | |
407 | ||
408 | if (n & POLLIN) { | |
409 | set_bit(Rpending, &m->wsched); | |
410 | dprintk(DEBUG_MUX, "mux %p can read\n", m); | |
411 | if (!test_and_set_bit(Rworksched, &m->wsched)) { | |
412 | dprintk(DEBUG_MUX, "schedule read work mux %p\n", m); | |
413 | queue_work(v9fs_mux_wq, &m->rq); | |
414 | } | |
415 | } | |
426cc91a | 416 | |
3cf6429a LI |
417 | if (n & POLLOUT) { |
418 | set_bit(Wpending, &m->wsched); | |
419 | dprintk(DEBUG_MUX, "mux %p can write\n", m); | |
420 | if ((m->wsize || !list_empty(&m->unsent_req_list)) | |
421 | && !test_and_set_bit(Wworksched, &m->wsched)) { | |
422 | dprintk(DEBUG_MUX, "schedule write work mux %p\n", m); | |
423 | queue_work(v9fs_mux_wq, &m->wq); | |
424 | } | |
425 | } | |
426cc91a EVH |
426 | } |
427 | ||
428 | /** | |
3cf6429a LI |
429 | * v9fs_poll_proc - polls all v9fs transports for new events and queues |
430 | * the appropriate work to the work queue | |
426cc91a | 431 | */ |
3cf6429a | 432 | static int v9fs_poll_proc(void *a) |
426cc91a | 433 | { |
3cf6429a LI |
434 | struct v9fs_mux_data *m, *mtmp; |
435 | struct v9fs_mux_poll_task *vpt; | |
426cc91a | 436 | |
3cf6429a LI |
437 | vpt = a; |
438 | dprintk(DEBUG_MUX, "start %p %p\n", current, vpt); | |
439 | allow_signal(SIGKILL); | |
440 | while (!kthread_should_stop()) { | |
441 | set_current_state(TASK_INTERRUPTIBLE); | |
442 | if (signal_pending(current)) | |
443 | break; | |
426cc91a | 444 | |
3cf6429a LI |
445 | list_for_each_entry_safe(m, mtmp, &vpt->mux_list, mux_list) { |
446 | v9fs_poll_mux(m); | |
447 | } | |
448 | ||
449 | dprintk(DEBUG_MUX, "sleeping...\n"); | |
450 | schedule_timeout(SCHED_TIMEOUT * HZ); | |
451 | } | |
cb2e87a6 | 452 | |
3cf6429a LI |
453 | __set_current_state(TASK_RUNNING); |
454 | dprintk(DEBUG_MUX, "finish\n"); | |
455 | return 0; | |
456 | } | |
426cc91a | 457 | |
3cf6429a LI |
458 | /** |
459 | * v9fs_write_work - called when a transport can send some data | |
460 | */ | |
461 | static void v9fs_write_work(void *a) | |
462 | { | |
463 | int n, err; | |
464 | struct v9fs_mux_data *m; | |
531b1094 | 465 | struct v9fs_req *req; |
426cc91a | 466 | |
3cf6429a | 467 | m = a; |
426cc91a | 468 | |
3cf6429a LI |
469 | if (m->err < 0) { |
470 | clear_bit(Wworksched, &m->wsched); | |
471 | return; | |
426cc91a EVH |
472 | } |
473 | ||
3cf6429a LI |
474 | if (!m->wsize) { |
475 | if (list_empty(&m->unsent_req_list)) { | |
476 | clear_bit(Wworksched, &m->wsched); | |
477 | return; | |
426cc91a EVH |
478 | } |
479 | ||
3cf6429a | 480 | spin_lock(&m->lock); |
034b91a3 LI |
481 | again: |
482 | req = list_entry(m->unsent_req_list.next, struct v9fs_req, | |
531b1094 LI |
483 | req_list); |
484 | list_move_tail(&req->req_list, &m->req_list); | |
034b91a3 LI |
485 | if (req->err == ERREQFLUSH) |
486 | goto again; | |
487 | ||
531b1094 LI |
488 | m->wbuf = req->tcall->sdata; |
489 | m->wsize = req->tcall->size; | |
3cf6429a | 490 | m->wpos = 0; |
531b1094 | 491 | dump_data(m->wbuf, m->wsize); |
3cf6429a | 492 | spin_unlock(&m->lock); |
426cc91a EVH |
493 | } |
494 | ||
3cf6429a LI |
495 | dprintk(DEBUG_MUX, "mux %p pos %d size %d\n", m, m->wpos, m->wsize); |
496 | clear_bit(Wpending, &m->wsched); | |
497 | err = m->trans->write(m->trans, m->wbuf + m->wpos, m->wsize - m->wpos); | |
498 | dprintk(DEBUG_MUX, "mux %p sent %d bytes\n", m, err); | |
499 | if (err == -EAGAIN) { | |
500 | clear_bit(Wworksched, &m->wsched); | |
501 | return; | |
502 | } | |
503 | ||
504 | if (err <= 0) | |
505 | goto error; | |
506 | ||
507 | m->wpos += err; | |
508 | if (m->wpos == m->wsize) | |
509 | m->wpos = m->wsize = 0; | |
510 | ||
511 | if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) { | |
512 | if (test_and_clear_bit(Wpending, &m->wsched)) | |
513 | n = POLLOUT; | |
514 | else | |
515 | n = m->trans->poll(m->trans, NULL); | |
516 | ||
517 | if (n & POLLOUT) { | |
518 | dprintk(DEBUG_MUX, "schedule write work mux %p\n", m); | |
519 | queue_work(v9fs_mux_wq, &m->wq); | |
520 | } else | |
521 | clear_bit(Wworksched, &m->wsched); | |
522 | } else | |
523 | clear_bit(Wworksched, &m->wsched); | |
426cc91a | 524 | |
3cf6429a LI |
525 | return; |
526 | ||
527 | error: | |
528 | v9fs_mux_cancel(m, err); | |
529 | clear_bit(Wworksched, &m->wsched); | |
426cc91a EVH |
530 | } |
531 | ||
3cf6429a | 532 | static void process_request(struct v9fs_mux_data *m, struct v9fs_req *req) |
322b329a | 533 | { |
41e5a6ac | 534 | int ecode; |
531b1094 | 535 | struct v9fs_str *ename; |
3cf6429a | 536 | |
034b91a3 | 537 | if (!req->err && req->rcall->id == RERROR) { |
3cf6429a | 538 | ecode = req->rcall->params.rerror.errno; |
531b1094 | 539 | ename = &req->rcall->params.rerror.error; |
322b329a | 540 | |
531b1094 | 541 | dprintk(DEBUG_MUX, "Rerror %.*s\n", ename->len, ename->str); |
3cf6429a LI |
542 | |
543 | if (*m->extended) | |
544 | req->err = -ecode; | |
545 | ||
546 | if (!req->err) { | |
531b1094 | 547 | req->err = v9fs_errstr2errno(ename->str, ename->len); |
3cf6429a LI |
548 | |
549 | if (!req->err) { /* string match failed */ | |
531b1094 | 550 | PRINT_FCALL_ERROR("unknown error", req->rcall); |
3cf6429a LI |
551 | } |
552 | ||
553 | if (!req->err) | |
554 | req->err = -ESERVERFAULT; | |
555 | } | |
556 | } else if (req->tcall && req->rcall->id != req->tcall->id + 1) { | |
557 | dprintk(DEBUG_ERROR, "fcall mismatch: expected %d, got %d\n", | |
558 | req->tcall->id + 1, req->rcall->id); | |
559 | if (!req->err) | |
560 | req->err = -EIO; | |
322b329a | 561 | } |
322b329a EVH |
562 | } |
563 | ||
426cc91a | 564 | /** |
3cf6429a | 565 | * v9fs_read_work - called when there is some data to be read from a transport |
426cc91a | 566 | */ |
3cf6429a | 567 | static void v9fs_read_work(void *a) |
426cc91a | 568 | { |
531b1094 | 569 | int n, err; |
3cf6429a LI |
570 | struct v9fs_mux_data *m; |
571 | struct v9fs_req *req, *rptr, *rreq; | |
572 | struct v9fs_fcall *rcall; | |
531b1094 | 573 | char *rbuf; |
3cf6429a LI |
574 | |
575 | m = a; | |
576 | ||
577 | if (m->err < 0) | |
578 | return; | |
579 | ||
580 | rcall = NULL; | |
581 | dprintk(DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos); | |
531b1094 LI |
582 | |
583 | if (!m->rcall) { | |
584 | m->rcall = | |
585 | kmalloc(sizeof(struct v9fs_fcall) + m->msize, GFP_KERNEL); | |
586 | if (!m->rcall) { | |
587 | err = -ENOMEM; | |
588 | goto error; | |
589 | } | |
590 | ||
591 | m->rbuf = (char *)m->rcall + sizeof(struct v9fs_fcall); | |
592 | m->rpos = 0; | |
593 | } | |
594 | ||
3cf6429a LI |
595 | clear_bit(Rpending, &m->wsched); |
596 | err = m->trans->read(m->trans, m->rbuf + m->rpos, m->msize - m->rpos); | |
597 | dprintk(DEBUG_MUX, "mux %p got %d bytes\n", m, err); | |
598 | if (err == -EAGAIN) { | |
599 | clear_bit(Rworksched, &m->wsched); | |
600 | return; | |
601 | } | |
426cc91a | 602 | |
3cf6429a LI |
603 | if (err <= 0) |
604 | goto error; | |
426cc91a | 605 | |
3cf6429a LI |
606 | m->rpos += err; |
607 | while (m->rpos > 4) { | |
608 | n = le32_to_cpu(*(__le32 *) m->rbuf); | |
609 | if (n >= m->msize) { | |
610 | dprintk(DEBUG_ERROR, | |
611 | "requested packet size too big: %d\n", n); | |
612 | err = -EIO; | |
613 | goto error; | |
614 | } | |
615 | ||
616 | if (m->rpos < n) | |
426cc91a | 617 | break; |
3cf6429a | 618 | |
3cf6429a | 619 | dump_data(m->rbuf, n); |
531b1094 LI |
620 | err = |
621 | v9fs_deserialize_fcall(m->rbuf, n, m->rcall, *m->extended); | |
cb2e87a6 | 622 | if (err < 0) { |
3cf6429a | 623 | goto error; |
426cc91a EVH |
624 | } |
625 | ||
5174fdab LI |
626 | if ((v9fs_debug_level&DEBUG_FCALL) == DEBUG_FCALL) { |
627 | char buf[150]; | |
628 | ||
629 | v9fs_printfcall(buf, sizeof(buf), m->rcall, | |
630 | *m->extended); | |
631 | printk(KERN_NOTICE ">>> %p %s\n", m, buf); | |
632 | } | |
633 | ||
531b1094 LI |
634 | rcall = m->rcall; |
635 | rbuf = m->rbuf; | |
636 | if (m->rpos > n) { | |
637 | m->rcall = kmalloc(sizeof(struct v9fs_fcall) + m->msize, | |
638 | GFP_KERNEL); | |
639 | if (!m->rcall) { | |
640 | err = -ENOMEM; | |
641 | goto error; | |
642 | } | |
643 | ||
644 | m->rbuf = (char *)m->rcall + sizeof(struct v9fs_fcall); | |
645 | memmove(m->rbuf, rbuf + n, m->rpos - n); | |
646 | m->rpos -= n; | |
647 | } else { | |
648 | m->rcall = NULL; | |
649 | m->rbuf = NULL; | |
650 | m->rpos = 0; | |
651 | } | |
652 | ||
3cf6429a LI |
653 | dprintk(DEBUG_MUX, "mux %p fcall id %d tag %d\n", m, rcall->id, |
654 | rcall->tag); | |
655 | ||
656 | req = NULL; | |
657 | spin_lock(&m->lock); | |
658 | list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) { | |
659 | if (rreq->tag == rcall->tag) { | |
660 | req = rreq; | |
41e5a6ac LI |
661 | if (req->flush != Flushing) |
662 | list_del(&req->req_list); | |
3cf6429a | 663 | break; |
426cc91a EVH |
664 | } |
665 | } | |
41e5a6ac | 666 | spin_unlock(&m->lock); |
426cc91a | 667 | |
41e5a6ac LI |
668 | if (req) { |
669 | req->rcall = rcall; | |
670 | process_request(m, req); | |
671 | ||
672 | if (req->flush != Flushing) { | |
673 | if (req->cb) | |
674 | (*req->cb) (req, req->cba); | |
675 | else | |
676 | kfree(req->rcall); | |
677 | ||
678 | wake_up(&m->equeue); | |
679 | } | |
680 | } else { | |
3cf6429a | 681 | if (err >= 0 && rcall->id != RFLUSH) |
cb2e87a6 | 682 | dprintk(DEBUG_ERROR, |
3cf6429a LI |
683 | "unexpected response mux %p id %d tag %d\n", |
684 | m, rcall->id, rcall->tag); | |
426cc91a EVH |
685 | kfree(rcall); |
686 | } | |
426cc91a EVH |
687 | } |
688 | ||
3cf6429a LI |
689 | if (!list_empty(&m->req_list)) { |
690 | if (test_and_clear_bit(Rpending, &m->wsched)) | |
691 | n = POLLIN; | |
692 | else | |
693 | n = m->trans->poll(m->trans, NULL); | |
694 | ||
695 | if (n & POLLIN) { | |
696 | dprintk(DEBUG_MUX, "schedule read work mux %p\n", m); | |
697 | queue_work(v9fs_mux_wq, &m->rq); | |
698 | } else | |
699 | clear_bit(Rworksched, &m->wsched); | |
700 | } else | |
701 | clear_bit(Rworksched, &m->wsched); | |
426cc91a | 702 | |
3cf6429a | 703 | return; |
426cc91a | 704 | |
3cf6429a LI |
705 | error: |
706 | v9fs_mux_cancel(m, err); | |
707 | clear_bit(Rworksched, &m->wsched); | |
426cc91a EVH |
708 | } |
709 | ||
710 | /** | |
3cf6429a LI |
711 | * v9fs_send_request - send 9P request |
712 | * The function can sleep until the request is scheduled for sending. | |
713 | * The function can be interrupted. Return from the function is not | |
d6e05edc | 714 | * a guarantee that the request is sent successfully. Can return errors |
3cf6429a | 715 | * that can be retrieved by PTR_ERR macros. |
426cc91a | 716 | * |
3cf6429a LI |
717 | * @m: mux data |
718 | * @tc: request to be sent | |
719 | * @cb: callback function to call when response is received | |
720 | * @cba: parameter to pass to the callback function | |
426cc91a | 721 | */ |
3cf6429a LI |
722 | static struct v9fs_req *v9fs_send_request(struct v9fs_mux_data *m, |
723 | struct v9fs_fcall *tc, | |
724 | v9fs_mux_req_callback cb, void *cba) | |
725 | { | |
726 | int n; | |
727 | struct v9fs_req *req; | |
728 | ||
729 | dprintk(DEBUG_MUX, "mux %p task %p tcall %p id %d\n", m, current, | |
730 | tc, tc->id); | |
731 | if (m->err < 0) | |
732 | return ERR_PTR(m->err); | |
733 | ||
734 | req = kmalloc(sizeof(struct v9fs_req), GFP_KERNEL); | |
735 | if (!req) | |
736 | return ERR_PTR(-ENOMEM); | |
426cc91a | 737 | |
3cf6429a LI |
738 | if (tc->id == TVERSION) |
739 | n = V9FS_NOTAG; | |
740 | else | |
531b1094 | 741 | n = v9fs_mux_get_tag(m); |
3cf6429a LI |
742 | |
743 | if (n < 0) | |
744 | return ERR_PTR(-ENOMEM); | |
745 | ||
531b1094 | 746 | v9fs_set_tag(tc, n); |
5174fdab LI |
747 | if ((v9fs_debug_level&DEBUG_FCALL) == DEBUG_FCALL) { |
748 | char buf[150]; | |
749 | ||
750 | v9fs_printfcall(buf, sizeof(buf), tc, *m->extended); | |
751 | printk(KERN_NOTICE "<<< %p %s\n", m, buf); | |
752 | } | |
753 | ||
41e5a6ac | 754 | spin_lock_init(&req->lock); |
3cf6429a LI |
755 | req->tag = n; |
756 | req->tcall = tc; | |
757 | req->rcall = NULL; | |
758 | req->err = 0; | |
759 | req->cb = cb; | |
760 | req->cba = cba; | |
41e5a6ac | 761 | req->flush = None; |
3cf6429a LI |
762 | |
763 | spin_lock(&m->lock); | |
764 | list_add_tail(&req->req_list, &m->unsent_req_list); | |
765 | spin_unlock(&m->lock); | |
766 | ||
767 | if (test_and_clear_bit(Wpending, &m->wsched)) | |
768 | n = POLLOUT; | |
769 | else | |
770 | n = m->trans->poll(m->trans, NULL); | |
771 | ||
772 | if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched)) | |
773 | queue_work(v9fs_mux_wq, &m->wq); | |
774 | ||
775 | return req; | |
776 | } | |
777 | ||
41e5a6ac LI |
778 | static void v9fs_mux_free_request(struct v9fs_mux_data *m, struct v9fs_req *req) |
779 | { | |
780 | v9fs_mux_put_tag(m, req->tag); | |
781 | kfree(req); | |
782 | } | |
783 | ||
784 | static void v9fs_mux_flush_cb(struct v9fs_req *freq, void *a) | |
426cc91a | 785 | { |
3cf6429a LI |
786 | v9fs_mux_req_callback cb; |
787 | int tag; | |
788 | struct v9fs_mux_data *m; | |
41e5a6ac | 789 | struct v9fs_req *req, *rreq, *rptr; |
3cf6429a LI |
790 | |
791 | m = a; | |
41e5a6ac LI |
792 | dprintk(DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m, |
793 | freq->tcall, freq->rcall, freq->err, | |
794 | freq->tcall->params.tflush.oldtag); | |
3cf6429a LI |
795 | |
796 | spin_lock(&m->lock); | |
797 | cb = NULL; | |
41e5a6ac LI |
798 | tag = freq->tcall->params.tflush.oldtag; |
799 | req = NULL; | |
800 | list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) { | |
801 | if (rreq->tag == tag) { | |
802 | req = rreq; | |
3cf6429a | 803 | list_del(&req->req_list); |
3cf6429a LI |
804 | break; |
805 | } | |
806 | } | |
41e5a6ac | 807 | spin_unlock(&m->lock); |
3cf6429a | 808 | |
41e5a6ac LI |
809 | if (req) { |
810 | spin_lock(&req->lock); | |
811 | req->flush = Flushed; | |
812 | spin_unlock(&req->lock); | |
813 | ||
814 | if (req->cb) | |
815 | (*req->cb) (req, req->cba); | |
816 | else | |
817 | kfree(req->rcall); | |
818 | ||
819 | wake_up(&m->equeue); | |
820 | } | |
3cf6429a | 821 | |
41e5a6ac LI |
822 | kfree(freq->tcall); |
823 | kfree(freq->rcall); | |
824 | v9fs_mux_free_request(m, freq); | |
3cf6429a LI |
825 | } |
826 | ||
41e5a6ac | 827 | static int |
3cf6429a LI |
828 | v9fs_mux_flush_request(struct v9fs_mux_data *m, struct v9fs_req *req) |
829 | { | |
830 | struct v9fs_fcall *fc; | |
41e5a6ac | 831 | struct v9fs_req *rreq, *rptr; |
3cf6429a LI |
832 | |
833 | dprintk(DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag); | |
834 | ||
41e5a6ac LI |
835 | /* if a response was received for a request, do nothing */ |
836 | spin_lock(&req->lock); | |
837 | if (req->rcall || req->err) { | |
838 | spin_unlock(&req->lock); | |
839 | dprintk(DEBUG_MUX, "mux %p req %p response already received\n", m, req); | |
840 | return 0; | |
841 | } | |
842 | ||
843 | req->flush = Flushing; | |
844 | spin_unlock(&req->lock); | |
845 | ||
846 | spin_lock(&m->lock); | |
847 | /* if the request is not sent yet, just remove it from the list */ | |
848 | list_for_each_entry_safe(rreq, rptr, &m->unsent_req_list, req_list) { | |
849 | if (rreq->tag == req->tag) { | |
850 | dprintk(DEBUG_MUX, "mux %p req %p request is not sent yet\n", m, req); | |
851 | list_del(&rreq->req_list); | |
852 | req->flush = Flushed; | |
853 | spin_unlock(&m->lock); | |
854 | if (req->cb) | |
855 | (*req->cb) (req, req->cba); | |
856 | return 0; | |
857 | } | |
858 | } | |
859 | spin_unlock(&m->lock); | |
860 | ||
861 | clear_thread_flag(TIF_SIGPENDING); | |
531b1094 | 862 | fc = v9fs_create_tflush(req->tag); |
3cf6429a | 863 | v9fs_send_request(m, fc, v9fs_mux_flush_cb, m); |
41e5a6ac | 864 | return 1; |
3cf6429a LI |
865 | } |
866 | ||
867 | static void | |
41e5a6ac | 868 | v9fs_mux_rpc_cb(struct v9fs_req *req, void *a) |
3cf6429a LI |
869 | { |
870 | struct v9fs_mux_rpc *r; | |
871 | ||
41e5a6ac | 872 | dprintk(DEBUG_MUX, "req %p r %p\n", req, a); |
3cf6429a | 873 | r = a; |
41e5a6ac LI |
874 | r->rcall = req->rcall; |
875 | r->err = req->err; | |
876 | ||
877 | if (req->flush!=None && !req->err) | |
878 | r->err = -ERESTARTSYS; | |
879 | ||
3cf6429a LI |
880 | wake_up(&r->wqueue); |
881 | } | |
882 | ||
883 | /** | |
884 | * v9fs_mux_rpc - sends 9P request and waits until a response is available. | |
885 | * The function can be interrupted. | |
886 | * @m: mux data | |
887 | * @tc: request to be sent | |
888 | * @rc: pointer where a pointer to the response is stored | |
889 | */ | |
890 | int | |
891 | v9fs_mux_rpc(struct v9fs_mux_data *m, struct v9fs_fcall *tc, | |
892 | struct v9fs_fcall **rc) | |
893 | { | |
41e5a6ac | 894 | int err, sigpending; |
3cf6429a LI |
895 | unsigned long flags; |
896 | struct v9fs_req *req; | |
897 | struct v9fs_mux_rpc r; | |
898 | ||
899 | r.err = 0; | |
41e5a6ac | 900 | r.tcall = tc; |
3cf6429a LI |
901 | r.rcall = NULL; |
902 | r.m = m; | |
903 | init_waitqueue_head(&r.wqueue); | |
904 | ||
905 | if (rc) | |
906 | *rc = NULL; | |
907 | ||
41e5a6ac LI |
908 | sigpending = 0; |
909 | if (signal_pending(current)) { | |
910 | sigpending = 1; | |
911 | clear_thread_flag(TIF_SIGPENDING); | |
912 | } | |
913 | ||
3cf6429a LI |
914 | req = v9fs_send_request(m, tc, v9fs_mux_rpc_cb, &r); |
915 | if (IS_ERR(req)) { | |
916 | err = PTR_ERR(req); | |
917 | dprintk(DEBUG_MUX, "error %d\n", err); | |
41e5a6ac | 918 | return err; |
3cf6429a LI |
919 | } |
920 | ||
3cf6429a LI |
921 | err = wait_event_interruptible(r.wqueue, r.rcall != NULL || r.err < 0); |
922 | if (r.err < 0) | |
923 | err = r.err; | |
924 | ||
925 | if (err == -ERESTARTSYS && m->trans->status == Connected && m->err == 0) { | |
41e5a6ac LI |
926 | if (v9fs_mux_flush_request(m, req)) { |
927 | /* wait until we get response of the flush message */ | |
928 | do { | |
929 | clear_thread_flag(TIF_SIGPENDING); | |
930 | err = wait_event_interruptible(r.wqueue, | |
931 | r.rcall || r.err); | |
932 | } while (!r.rcall && !r.err && err==-ERESTARTSYS && | |
933 | m->trans->status==Connected && !m->err); | |
94374e7c LI |
934 | |
935 | err = -ERESTARTSYS; | |
41e5a6ac LI |
936 | } |
937 | sigpending = 1; | |
938 | } | |
3cf6429a | 939 | |
41e5a6ac | 940 | if (sigpending) { |
3cf6429a LI |
941 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
942 | recalc_sigpending(); | |
943 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
426cc91a EVH |
944 | } |
945 | ||
41e5a6ac LI |
946 | if (rc) |
947 | *rc = r.rcall; | |
948 | else | |
3cf6429a | 949 | kfree(r.rcall); |
41e5a6ac LI |
950 | |
951 | v9fs_mux_free_request(m, req); | |
952 | if (err > 0) | |
953 | err = -EIO; | |
3cf6429a LI |
954 | |
955 | return err; | |
956 | } | |
957 | ||
29c6e486 | 958 | #if 0 |
3cf6429a LI |
959 | /** |
960 | * v9fs_mux_rpcnb - sends 9P request without waiting for response. | |
961 | * @m: mux data | |
962 | * @tc: request to be sent | |
963 | * @cb: callback function to be called when response arrives | |
964 | * @cba: value to pass to the callback function | |
965 | */ | |
966 | int v9fs_mux_rpcnb(struct v9fs_mux_data *m, struct v9fs_fcall *tc, | |
967 | v9fs_mux_req_callback cb, void *a) | |
968 | { | |
969 | int err; | |
970 | struct v9fs_req *req; | |
971 | ||
972 | req = v9fs_send_request(m, tc, cb, a); | |
973 | if (IS_ERR(req)) { | |
974 | err = PTR_ERR(req); | |
975 | dprintk(DEBUG_MUX, "error %d\n", err); | |
976 | return PTR_ERR(req); | |
977 | } | |
426cc91a | 978 | |
3cf6429a | 979 | dprintk(DEBUG_MUX, "mux %p tc %p tag %d\n", m, tc, req->tag); |
426cc91a EVH |
980 | return 0; |
981 | } | |
29c6e486 | 982 | #endif /* 0 */ |
3cf6429a LI |
983 | |
984 | /** | |
985 | * v9fs_mux_cancel - cancel all pending requests with error | |
986 | * @m: mux data | |
987 | * @err: error code | |
988 | */ | |
989 | void v9fs_mux_cancel(struct v9fs_mux_data *m, int err) | |
990 | { | |
991 | struct v9fs_req *req, *rtmp; | |
992 | LIST_HEAD(cancel_list); | |
993 | ||
41e5a6ac | 994 | dprintk(DEBUG_ERROR, "mux %p err %d\n", m, err); |
3cf6429a LI |
995 | m->err = err; |
996 | spin_lock(&m->lock); | |
997 | list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) { | |
998 | list_move(&req->req_list, &cancel_list); | |
999 | } | |
41e5a6ac LI |
1000 | list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) { |
1001 | list_move(&req->req_list, &cancel_list); | |
1002 | } | |
3cf6429a LI |
1003 | spin_unlock(&m->lock); |
1004 | ||
1005 | list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) { | |
1006 | list_del(&req->req_list); | |
1007 | if (!req->err) | |
1008 | req->err = err; | |
1009 | ||
1010 | if (req->cb) | |
41e5a6ac | 1011 | (*req->cb) (req, req->cba); |
3cf6429a LI |
1012 | else |
1013 | kfree(req->rcall); | |
3cf6429a LI |
1014 | } |
1015 | ||
1016 | wake_up(&m->equeue); | |
1017 | } | |
531b1094 LI |
1018 | |
1019 | static u16 v9fs_mux_get_tag(struct v9fs_mux_data *m) | |
1020 | { | |
1021 | int tag; | |
1022 | ||
4a26c242 | 1023 | tag = v9fs_get_idpool(&m->tagpool); |
531b1094 LI |
1024 | if (tag < 0) |
1025 | return V9FS_NOTAG; | |
1026 | else | |
1027 | return (u16) tag; | |
1028 | } | |
1029 | ||
1030 | static void v9fs_mux_put_tag(struct v9fs_mux_data *m, u16 tag) | |
1031 | { | |
4a26c242 RC |
1032 | if (tag != V9FS_NOTAG && v9fs_check_idpool(tag, &m->tagpool)) |
1033 | v9fs_put_idpool(tag, &m->tagpool); | |
531b1094 | 1034 | } |