aboutsummaryrefslogtreecommitdiffstats
path: root/fs/smbfs/smbiod.c
blob: 24577e2c489b7997e40a691d076c88dd4ac03f79 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
/*
 *  smbiod.c
 *
 *  Copyright (C) 2000, Charles Loep / Corel Corp.
 *  Copyright (C) 2001, Urban Widmark
 */

#include <linux/config.h>

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/file.h>
#include <linux/dcache.h>
#include <linux/smp_lock.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/kthread.h>
#include <net/ip.h>

#include <linux/smb_fs.h>
#include <linux/smbno.h>
#include <linux/smb_mount.h>

#include <asm/system.h>
#include <asm/uaccess.h>

#include "smb_debug.h"
#include "request.h"
#include "proto.h"

enum smbiod_state {
	SMBIOD_DEAD,
	SMBIOD_STARTING,
	SMBIOD_RUNNING,
};

static enum smbiod_state smbiod_state = SMBIOD_DEAD;
static struct task_struct *smbiod_thread;
static DECLARE_WAIT_QUEUE_HEAD(smbiod_wait);
static LIST_HEAD(smb_servers);
static DEFINE_SPINLOCK(servers_lock);

#define SMBIOD_DATA_READY	(1<<0)
static long smbiod_flags;

static int smbiod(void *);
static int smbiod_start(void);

/*
 * called when there's work for us to do
 */
void smbiod_wake_up(void)
{
	if (smbiod_state == SMBIOD_DEAD)
		return;
	set_bit(SMBIOD_DATA_READY, &smbiod_flags);
	wake_up_interruptible(&smbiod_wait);
}

/*
 * start smbiod if none is running
 */
static int smbiod_start(void)
{
	struct task_struct *tsk;
	int err = 0;

	if (smbiod_state != SMBIOD_DEAD)
		return 0;
	smbiod_state = SMBIOD_STARTING;
	__module_get(THIS_MODULE);
	spin_unlock(&servers_lock);
	tsk = kthread_run(smbiod, NULL, "smbiod");
	if (IS_ERR(tsk)) {
		err = PTR_ERR(tsk);
		module_put(THIS_MODULE);
	}

	spin_lock(&servers_lock);
	if (err < 0) {
		smbiod_state = SMBIOD_DEAD;
		smbiod_thread = NULL;
	} else {
		smbiod_state = SMBIOD_RUNNING;
		smbiod_thread = tsk;
	}
	return err;
}

/*
 * register a server & start smbiod if necessary
 */
int smbiod_register_server(struct smb_sb_info *server)
{
	int ret;
	spin_lock(&servers_lock);
	list_add(&server->entry, &smb_servers);
	VERBOSE("%p\n", server);
	ret = smbiod_start();
	spin_unlock(&servers_lock);
	return ret;
}

/*
 * Unregister a server
 * Must be called with the server lock held.
 */
void smbiod_unregister_server(struct smb_sb_info *server)
{
	spin_lock(&servers_lock);
	list_del_init(&server->entry);
	VERBOSE("%p\n", server);
	spin_unlock(&servers_lock);

	smbiod_wake_up();
	smbiod_flush(server);
}

void smbiod_flush(struct smb_sb_info *server)
{
	struct list_head *tmp, *n;
	struct smb_request *req;

	list_for_each_safe(tmp, n, &server->xmitq) {
		req = list_entry(tmp, struct smb_request, rq_queue);
		req->rq_errno = -EIO;
		list_del_init(&req->rq_queue);
		smb_rput(req);
		wake_up_interruptible(&req->rq_wait);
	}
	list_for_each_safe(tmp, n, &server->recvq) {
		req = list_entry(tmp, struct smb_request, rq_queue);
		req->rq_errno = -EIO;
		list_del_init(&req->rq_queue);
		smb_rput(req);
		wake_up_interruptible(&req->rq_wait);
	}
}

/*
 * Wake up smbmount and make it reconnect to the server.
 * This must be called with the server locked.
 *
 * FIXME: add smbconnect version to this
 */
int smbiod_retry(struct smb_sb_info *server)
{
	struct list_head *head;
	struct smb_request *req;
	pid_t pid = server->conn_pid;
	int result = 0;

	VERBOSE("state: %d\n", server->state);
	if (server->state == CONN_VALID || server->state == CONN_RETRYING)
		goto out;

	smb_invalidate_inodes(server);

	/*
	 * Some requests are meaningless after a retry, so we abort them.
	 * One example are all requests using 'fileid' since the files are
	 * closed on retry.
	 */
	head = server->xmitq.next;
	while (head != &server->xmitq) {
		req = list_entry(head, struct smb_request, rq_queue);
		head = head->next;

		req->rq_bytes_sent = 0;
		if (req->rq_flags & SMB_REQ_NORETRY) {
			VERBOSE("aborting request %p on xmitq\n", req);
			req->rq_errno = -EIO;
			list_del_init(&req->rq_queue);
			smb_rput(req);
			wake_up_interruptible(&req->rq_wait);
		}
	}

	/*
	 * FIXME: test the code for retrying request we already sent
	 */
	head = server->recvq.next;
	while (head != &server->recvq) {
		req = list_entry(head, struct smb_request, rq_queue);
		head = head->next;
#if 0
		if (req->rq_flags & SMB_REQ_RETRY) {
			/* must move the request to the xmitq */
			VERBOSE("retrying request %p on recvq\n", req);
			list_move(&req->rq_queue, &server->xmitq);
			continue;
		}
#endif

		VERBOSE("aborting request %p on recvq\n", req);
		/* req->rq_rcls = ???; */ /* FIXME: set smb error code too? */
		req->rq_errno = -EIO;
		list_del_init(&req->rq_queue);
		smb_rput(req);
		wake_up_interruptible(&req->rq_wait);
	}

	smb_close_socket(server);

	if (pid == 0) {
		/* FIXME: this is fatal, umount? */
		printk(KERN_ERR "smb_retry: no connection process\n");
		server->state = CONN_RETRIED;
		goto out;
	}

	/*
	 * Change state so that only one retry per server will be started.
	 */
	server->state = CONN_RETRYING;

	/*
	 * Note: use the "priv" flag, as a user process may need to reconnect.
	 */
	result = kill_proc(pid, SIGUSR1, 1);
	if (result) {
		/* FIXME: this is most likely fatal, umount? */
		printk(KERN_ERR "smb_retry: signal failed [%d]\n", result);
		goto out;
	}
	VERBOSE("signalled pid %d\n", pid);

	/* FIXME: The retried requests should perhaps get a "time boost". */

out:
	return result;
}

/*
 * Currently handles lockingX packets.
 */
static void smbiod_handle_request(struct smb_sb_info *server)
{
	PARANOIA("smbiod got a request ... and we don't implement oplocks!\n");
	server->rstate = SMB_RECV_DROP;
}

/*
 * Do some IO for one server.
 */
static void smbiod_doio(struct smb_sb_info *server)
{
	int result;
	int maxwork = 7;

	if (server->state != CONN_VALID)
		goto out;

	do {
		result = smb_request_recv(server);
		if (result < 0) {
			server->state = CONN_INVALID;
			smbiod_retry(server);
			goto out;	/* reconnecting is slow */
		} else if (server->rstate == SMB_RECV_REQUEST)
			smbiod_handle_request(server);
	} while (result > 0 && maxwork-- > 0);

	/*
	 * If there is more to read then we want to be sure to wake up again.
	 */
	if (server->state != CONN_VALID)
		goto out;
	if (smb_recv_available(server) > 0)
		set_bit(SMBIOD_DATA_READY, &smbiod_flags);

	do {
		result = smb_request_send_server(server);
		if (result < 0) {
			server->state = CONN_INVALID;
			smbiod_retry(server);
			goto out;	/* reconnecting is slow */
		}
	} while (result > 0);

	/*
	 * If the last request was not sent out we want to wake up again.
	 */
	if (!list_empty(&server->xmitq))
		set_bit(SMBIOD_DATA_READY, &smbiod_flags);

out:
	return;
}

/*
 * smbiod kernel thread
 */
static int smbiod(void *unused)
{
	allow_signal(SIGKILL);

	VERBOSE("SMB Kernel thread starting (%d) ...\n", current->pid);

	for (;;) {
		struct smb_sb_info *server;
		struct list_head *pos, *n;

		/* FIXME: Use poll? */
		wait_event_interruptible(smbiod_wait,
			 test_bit(SMBIOD_DATA_READY, &smbiod_flags));
		if (signal_pending(current)) {
			spin_lock(&servers_lock);
			smbiod_state = SMBIOD_DEAD;
			spin_unlock(&servers_lock);
			break;
		}

		clear_bit(SMBIOD_DATA_READY, &smbiod_flags);

		spin_lock(&servers_lock);
		if (list_empty(&smb_servers)) {
			smbiod_state = SMBIOD_DEAD;
			spin_unlock(&servers_lock);
			break;
		}

		list_for_each_safe(pos, n, &smb_servers) {
			server = list_entry(pos, struct smb_sb_info, entry);
			VERBOSE("checking server %p\n", server);

			if (server->state == CONN_VALID) {
				spin_unlock(&servers_lock);

				smb_lock_server(server);
				smbiod_doio(server);
				smb_unlock_server(server);

				spin_lock(&servers_lock);
			}
		}
		spin_unlock(&servers_lock);
	}

	VERBOSE("SMB Kernel thread exiting (%d) ...\n", current->pid);
	module_put_and_exit(0);
}