[AGPGART] Replace kmalloc+memset's with kzalloc's
[linux-2.6.22.y-op.git] / fs / 9p / mux.c
blob8835b576f7445c98eae41c69c9afde4f21d91b3a
1 /*
2 * linux/fs/9p/mux.c
4 * Protocol Multiplexer
6 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
7 * Copyright (C) 2004 by Latchesar Ionkov <lucho@ionkov.net>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to:
21 * Free Software Foundation
22 * 51 Franklin Street, Fifth Floor
23 * Boston, MA 02111-1301 USA
27 #include <linux/config.h>
28 #include <linux/module.h>
29 #include <linux/errno.h>
30 #include <linux/fs.h>
31 #include <linux/kthread.h>
32 #include <linux/idr.h>
34 #include "debug.h"
35 #include "v9fs.h"
36 #include "9p.h"
37 #include "transport.h"
38 #include "conv.h"
39 #include "mux.h"
41 /**
42 * dprintcond - print condition of session info
43 * @v9ses: session info structure
44 * @req: RPC request structure
48 static inline int
49 dprintcond(struct v9fs_session_info *v9ses, struct v9fs_rpcreq *req)
51 dprintk(DEBUG_MUX, "condition: %d, %p\n", v9ses->transport->status,
52 req->rcall);
53 return 0;
56 /**
57 * xread - force read of a certain number of bytes
58 * @v9ses: session info structure
59 * @ptr: pointer to buffer
60 * @sz: number of bytes to read
62 * Chuck Cranor CS-533 project1
65 static int xread(struct v9fs_session_info *v9ses, void *ptr, unsigned long sz)
67 int rd = 0;
68 int ret = 0;
69 while (rd < sz) {
70 ret = v9ses->transport->read(v9ses->transport, ptr, sz - rd);
71 if (ret <= 0) {
72 dprintk(DEBUG_ERROR, "xread errno %d\n", ret);
73 return ret;
75 rd += ret;
76 ptr += ret;
78 return (rd);
81 /**
82 * read_message - read a full 9P2000 fcall packet
83 * @v9ses: session info structure
84 * @rcall: fcall structure to read into
85 * @rcalllen: size of fcall buffer
89 static int
90 read_message(struct v9fs_session_info *v9ses,
91 struct v9fs_fcall *rcall, int rcalllen)
93 unsigned char buf[4];
94 void *data;
95 int size = 0;
96 int res = 0;
98 res = xread(v9ses, buf, sizeof(buf));
99 if (res < 0) {
100 dprintk(DEBUG_ERROR,
101 "Reading of count field failed returned: %d\n", res);
102 return res;
105 if (res < 4) {
106 dprintk(DEBUG_ERROR,
107 "Reading of count field failed returned: %d\n", res);
108 return -EIO;
111 size = buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
112 dprintk(DEBUG_MUX, "got a packet count: %d\n", size);
114 /* adjust for the four bytes of size */
115 size -= 4;
117 if (size > v9ses->maxdata) {
118 dprintk(DEBUG_ERROR, "packet too big: %d\n", size);
119 return -E2BIG;
122 data = kmalloc(size, GFP_KERNEL);
123 if (!data) {
124 eprintk(KERN_WARNING, "out of memory\n");
125 return -ENOMEM;
128 res = xread(v9ses, data, size);
129 if (res < size) {
130 dprintk(DEBUG_ERROR, "Reading of fcall failed returned: %d\n",
131 res);
132 kfree(data);
133 return res;
136 /* we now have an in-memory string that is the reply.
137 * deserialize it. There is very little to go wrong at this point
138 * save for v9fs_alloc errors.
140 res = v9fs_deserialize_fcall(v9ses, size, data, v9ses->maxdata,
141 rcall, rcalllen);
143 kfree(data);
145 if (res < 0)
146 return res;
148 return 0;
152 * v9fs_recv - receive an RPC response for a particular tag
153 * @v9ses: session info structure
154 * @req: RPC request structure
158 static int v9fs_recv(struct v9fs_session_info *v9ses, struct v9fs_rpcreq *req)
160 int ret = 0;
162 dprintk(DEBUG_MUX, "waiting for response: %d\n", req->tcall->tag);
163 ret = wait_event_interruptible(v9ses->read_wait,
164 ((v9ses->transport->status != Connected) ||
165 (req->rcall != 0) || (req->err < 0) ||
166 dprintcond(v9ses, req)));
168 dprintk(DEBUG_MUX, "got it: rcall %p\n", req->rcall);
170 spin_lock(&v9ses->muxlock);
171 list_del(&req->next);
172 spin_unlock(&v9ses->muxlock);
174 if (req->err < 0)
175 return req->err;
177 if (v9ses->transport->status == Disconnected)
178 return -ECONNRESET;
180 return ret;
184 * v9fs_send - send a 9P request
185 * @v9ses: session info structure
186 * @req: RPC request to send
190 static int v9fs_send(struct v9fs_session_info *v9ses, struct v9fs_rpcreq *req)
192 int ret = -1;
193 void *data = NULL;
194 struct v9fs_fcall *tcall = req->tcall;
196 data = kmalloc(v9ses->maxdata + V9FS_IOHDRSZ, GFP_KERNEL);
197 if (!data)
198 return -ENOMEM;
200 tcall->size = 0; /* enforce size recalculation */
201 ret =
202 v9fs_serialize_fcall(v9ses, tcall, data,
203 v9ses->maxdata + V9FS_IOHDRSZ);
204 if (ret < 0)
205 goto free_data;
207 spin_lock(&v9ses->muxlock);
208 list_add(&req->next, &v9ses->mux_fcalls);
209 spin_unlock(&v9ses->muxlock);
211 dprintk(DEBUG_MUX, "sending message: tag %d size %d\n", tcall->tag,
212 tcall->size);
213 ret = v9ses->transport->write(v9ses->transport, data, tcall->size);
215 if (ret != tcall->size) {
216 spin_lock(&v9ses->muxlock);
217 list_del(&req->next);
218 kfree(req->rcall);
220 spin_unlock(&v9ses->muxlock);
221 if (ret >= 0)
222 ret = -EREMOTEIO;
223 } else
224 ret = 0;
226 free_data:
227 kfree(data);
228 return ret;
232 * v9fs_mux_rpc - send a request, receive a response
233 * @v9ses: session info structure
234 * @tcall: fcall to send
235 * @rcall: buffer to place response into
239 long
240 v9fs_mux_rpc(struct v9fs_session_info *v9ses, struct v9fs_fcall *tcall,
241 struct v9fs_fcall **rcall)
243 int tid = -1;
244 struct v9fs_fcall *fcall = NULL;
245 struct v9fs_rpcreq req;
246 int ret = -1;
248 if (!v9ses)
249 return -EINVAL;
251 if (!v9ses->transport || v9ses->transport->status != Connected)
252 return -EIO;
254 if (rcall)
255 *rcall = NULL;
257 if (tcall->id != TVERSION) {
258 tid = v9fs_get_idpool(&v9ses->tidpool);
259 if (tid < 0)
260 return -ENOMEM;
263 tcall->tag = tid;
265 req.tcall = tcall;
266 req.err = 0;
267 req.rcall = NULL;
269 ret = v9fs_send(v9ses, &req);
271 if (ret < 0) {
272 if (tcall->id != TVERSION)
273 v9fs_put_idpool(tid, &v9ses->tidpool);
274 dprintk(DEBUG_MUX, "error %d\n", ret);
275 return ret;
278 ret = v9fs_recv(v9ses, &req);
280 fcall = req.rcall;
282 dprintk(DEBUG_MUX, "received: tag=%x, ret=%d\n", tcall->tag, ret);
283 if (ret == -ERESTARTSYS) {
284 if (v9ses->transport->status != Disconnected
285 && tcall->id != TFLUSH) {
286 unsigned long flags;
288 dprintk(DEBUG_MUX, "flushing the tag: %d\n",
289 tcall->tag);
290 clear_thread_flag(TIF_SIGPENDING);
291 v9fs_t_flush(v9ses, tcall->tag);
292 spin_lock_irqsave(&current->sighand->siglock, flags);
293 recalc_sigpending();
294 spin_unlock_irqrestore(&current->sighand->siglock,
295 flags);
296 dprintk(DEBUG_MUX, "flushing done\n");
299 goto release_req;
300 } else if (ret < 0)
301 goto release_req;
303 if (!fcall)
304 ret = -EIO;
305 else {
306 if (fcall->id == RERROR) {
307 ret = v9fs_errstr2errno(fcall->params.rerror.error);
308 if (ret == 0) { /* string match failed */
309 if (fcall->params.rerror.errno)
310 ret = -(fcall->params.rerror.errno);
311 else
312 ret = -ESERVERFAULT;
314 } else if (fcall->id != tcall->id + 1) {
315 dprintk(DEBUG_ERROR,
316 "fcall mismatch: expected %d, got %d\n",
317 tcall->id + 1, fcall->id);
318 ret = -EIO;
322 release_req:
323 if (tcall->id != TVERSION)
324 v9fs_put_idpool(tid, &v9ses->tidpool);
325 if (rcall)
326 *rcall = fcall;
327 else
328 kfree(fcall);
330 return ret;
334 * v9fs_mux_cancel_requests - cancels all pending requests
336 * @v9ses: session info structure
337 * @err: error code to return to the requests
339 void v9fs_mux_cancel_requests(struct v9fs_session_info *v9ses, int err)
341 struct v9fs_rpcreq *rptr;
342 struct v9fs_rpcreq *rreq;
344 dprintk(DEBUG_MUX, " %d\n", err);
345 spin_lock(&v9ses->muxlock);
346 list_for_each_entry_safe(rreq, rptr, &v9ses->mux_fcalls, next) {
347 rreq->err = err;
349 spin_unlock(&v9ses->muxlock);
350 wake_up_all(&v9ses->read_wait);
354 * v9fs_recvproc - kproc to handle demultiplexing responses
355 * @data: session info structure
359 static int v9fs_recvproc(void *data)
361 struct v9fs_session_info *v9ses = (struct v9fs_session_info *)data;
362 struct v9fs_fcall *rcall = NULL;
363 struct v9fs_rpcreq *rptr;
364 struct v9fs_rpcreq *req;
365 struct v9fs_rpcreq *rreq;
366 int err = 0;
368 allow_signal(SIGKILL);
369 set_current_state(TASK_INTERRUPTIBLE);
370 complete(&v9ses->proccmpl);
371 while (!kthread_should_stop() && err >= 0) {
372 req = rptr = rreq = NULL;
374 rcall = kmalloc(v9ses->maxdata + V9FS_IOHDRSZ, GFP_KERNEL);
375 if (!rcall) {
376 eprintk(KERN_ERR, "no memory for buffers\n");
377 break;
380 err = read_message(v9ses, rcall, v9ses->maxdata + V9FS_IOHDRSZ);
381 spin_lock(&v9ses->muxlock);
382 if (err < 0) {
383 list_for_each_entry_safe(rreq, rptr, &v9ses->mux_fcalls, next) {
384 rreq->err = err;
386 if(err != -ERESTARTSYS)
387 eprintk(KERN_ERR,
388 "Transport error while reading message %d\n", err);
389 } else {
390 list_for_each_entry_safe(rreq, rptr, &v9ses->mux_fcalls, next) {
391 if (rreq->tcall->tag == rcall->tag) {
392 req = rreq;
393 req->rcall = rcall;
394 break;
399 if (req && (req->tcall->id == TFLUSH)) {
400 struct v9fs_rpcreq *treq = NULL;
401 list_for_each_entry_safe(treq, rptr, &v9ses->mux_fcalls, next) {
402 if (treq->tcall->tag ==
403 req->tcall->params.tflush.oldtag) {
404 list_del(&rptr->next);
405 kfree(treq->rcall);
406 break;
411 spin_unlock(&v9ses->muxlock);
413 if (!req) {
414 if (err >= 0)
415 dprintk(DEBUG_ERROR,
416 "unexpected response: id %d tag %d\n",
417 rcall->id, rcall->tag);
419 kfree(rcall);
422 wake_up_all(&v9ses->read_wait);
423 set_current_state(TASK_INTERRUPTIBLE);
426 v9ses->transport->close(v9ses->transport);
428 /* Inform all pending processes about the failure */
429 wake_up_all(&v9ses->read_wait);
431 if (signal_pending(current))
432 complete(&v9ses->proccmpl);
434 dprintk(DEBUG_MUX, "recvproc: end\n");
435 v9ses->recvproc = NULL;
437 return err >= 0;
441 * v9fs_mux_init - initialize multiplexer (spawn kproc)
442 * @v9ses: session info structure
443 * @dev_name: mount device information (to create unique kproc)
447 int v9fs_mux_init(struct v9fs_session_info *v9ses, const char *dev_name)
449 char procname[60];
451 strncpy(procname, dev_name, sizeof(procname));
452 procname[sizeof(procname) - 1] = 0;
454 init_waitqueue_head(&v9ses->read_wait);
455 init_completion(&v9ses->fcread);
456 init_completion(&v9ses->proccmpl);
457 spin_lock_init(&v9ses->muxlock);
458 INIT_LIST_HEAD(&v9ses->mux_fcalls);
459 v9ses->recvproc = NULL;
460 v9ses->curfcall = NULL;
462 v9ses->recvproc = kthread_create(v9fs_recvproc, v9ses,
463 "v9fs_recvproc %s", procname);
465 if (IS_ERR(v9ses->recvproc)) {
466 eprintk(KERN_ERR, "cannot create receiving thread\n");
467 v9fs_session_close(v9ses);
468 return -ECONNABORTED;
471 wake_up_process(v9ses->recvproc);
472 wait_for_completion(&v9ses->proccmpl);
474 return 0;