Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6.git] / fs / smbfs / smbiod.c
1 /*
2  *  smbiod.c
3  *
4  *  Copyright (C) 2000, Charles Loep / Corel Corp.
5  *  Copyright (C) 2001, Urban Widmark
6  */
7
8
9 #include <linux/sched.h>
10 #include <linux/kernel.h>
11 #include <linux/mm.h>
12 #include <linux/string.h>
13 #include <linux/stat.h>
14 #include <linux/errno.h>
15 #include <linux/slab.h>
16 #include <linux/init.h>
17 #include <linux/file.h>
18 #include <linux/dcache.h>
19 #include <linux/module.h>
20 #include <linux/net.h>
21 #include <linux/kthread.h>
22 #include <net/ip.h>
23
24 #include <linux/smb_fs.h>
25 #include <linux/smbno.h>
26 #include <linux/smb_mount.h>
27
28 #include <asm/system.h>
29 #include <asm/uaccess.h>
30
31 #include "smb_debug.h"
32 #include "request.h"
33 #include "proto.h"
34
35 enum smbiod_state {
36         SMBIOD_DEAD,
37         SMBIOD_STARTING,
38         SMBIOD_RUNNING,
39 };
40
41 static enum smbiod_state smbiod_state = SMBIOD_DEAD;
42 static struct task_struct *smbiod_thread;
43 static DECLARE_WAIT_QUEUE_HEAD(smbiod_wait);
44 static LIST_HEAD(smb_servers);
45 static DEFINE_SPINLOCK(servers_lock);
46
47 #define SMBIOD_DATA_READY       (1<<0)
48 static unsigned long smbiod_flags;
49
50 static int smbiod(void *);
51 static int smbiod_start(void);
52
53 /*
54  * called when there's work for us to do
55  */
56 void smbiod_wake_up(void)
57 {
58         if (smbiod_state == SMBIOD_DEAD)
59                 return;
60         set_bit(SMBIOD_DATA_READY, &smbiod_flags);
61         wake_up_interruptible(&smbiod_wait);
62 }
63
64 /*
65  * start smbiod if none is running
66  */
67 static int smbiod_start(void)
68 {
69         struct task_struct *tsk;
70         int err = 0;
71
72         if (smbiod_state != SMBIOD_DEAD)
73                 return 0;
74         smbiod_state = SMBIOD_STARTING;
75         __module_get(THIS_MODULE);
76         spin_unlock(&servers_lock);
77         tsk = kthread_run(smbiod, NULL, "smbiod");
78         if (IS_ERR(tsk)) {
79                 err = PTR_ERR(tsk);
80                 module_put(THIS_MODULE);
81         }
82
83         spin_lock(&servers_lock);
84         if (err < 0) {
85                 smbiod_state = SMBIOD_DEAD;
86                 smbiod_thread = NULL;
87         } else {
88                 smbiod_state = SMBIOD_RUNNING;
89                 smbiod_thread = tsk;
90         }
91         return err;
92 }
93
94 /*
95  * register a server & start smbiod if necessary
96  */
97 int smbiod_register_server(struct smb_sb_info *server)
98 {
99         int ret;
100         spin_lock(&servers_lock);
101         list_add(&server->entry, &smb_servers);
102         VERBOSE("%p\n", server);
103         ret = smbiod_start();
104         spin_unlock(&servers_lock);
105         return ret;
106 }
107
108 /*
109  * Unregister a server
110  * Must be called with the server lock held.
111  */
112 void smbiod_unregister_server(struct smb_sb_info *server)
113 {
114         spin_lock(&servers_lock);
115         list_del_init(&server->entry);
116         VERBOSE("%p\n", server);
117         spin_unlock(&servers_lock);
118
119         smbiod_wake_up();
120         smbiod_flush(server);
121 }
122
123 void smbiod_flush(struct smb_sb_info *server)
124 {
125         struct list_head *tmp, *n;
126         struct smb_request *req;
127
128         list_for_each_safe(tmp, n, &server->xmitq) {
129                 req = list_entry(tmp, struct smb_request, rq_queue);
130                 req->rq_errno = -EIO;
131                 list_del_init(&req->rq_queue);
132                 smb_rput(req);
133                 wake_up_interruptible(&req->rq_wait);
134         }
135         list_for_each_safe(tmp, n, &server->recvq) {
136                 req = list_entry(tmp, struct smb_request, rq_queue);
137                 req->rq_errno = -EIO;
138                 list_del_init(&req->rq_queue);
139                 smb_rput(req);
140                 wake_up_interruptible(&req->rq_wait);
141         }
142 }
143
144 /*
145  * Wake up smbmount and make it reconnect to the server.
146  * This must be called with the server locked.
147  *
148  * FIXME: add smbconnect version to this
149  */
150 int smbiod_retry(struct smb_sb_info *server)
151 {
152         struct list_head *head;
153         struct smb_request *req;
154         struct pid *pid = get_pid(server->conn_pid);
155         int result = 0;
156
157         VERBOSE("state: %d\n", server->state);
158         if (server->state == CONN_VALID || server->state == CONN_RETRYING)
159                 goto out;
160
161         smb_invalidate_inodes(server);
162
163         /*
164          * Some requests are meaningless after a retry, so we abort them.
165          * One example are all requests using 'fileid' since the files are
166          * closed on retry.
167          */
168         head = server->xmitq.next;
169         while (head != &server->xmitq) {
170                 req = list_entry(head, struct smb_request, rq_queue);
171                 head = head->next;
172
173                 req->rq_bytes_sent = 0;
174                 if (req->rq_flags & SMB_REQ_NORETRY) {
175                         VERBOSE("aborting request %p on xmitq\n", req);
176                         req->rq_errno = -EIO;
177                         list_del_init(&req->rq_queue);
178                         smb_rput(req);
179                         wake_up_interruptible(&req->rq_wait);
180                 }
181         }
182
183         /*
184          * FIXME: test the code for retrying request we already sent
185          */
186         head = server->recvq.next;
187         while (head != &server->recvq) {
188                 req = list_entry(head, struct smb_request, rq_queue);
189                 head = head->next;
190 #if 0
191                 if (req->rq_flags & SMB_REQ_RETRY) {
192                         /* must move the request to the xmitq */
193                         VERBOSE("retrying request %p on recvq\n", req);
194                         list_move(&req->rq_queue, &server->xmitq);
195                         continue;
196                 }
197 #endif
198
199                 VERBOSE("aborting request %p on recvq\n", req);
200                 /* req->rq_rcls = ???; */ /* FIXME: set smb error code too? */
201                 req->rq_errno = -EIO;
202                 list_del_init(&req->rq_queue);
203                 smb_rput(req);
204                 wake_up_interruptible(&req->rq_wait);
205         }
206
207         smb_close_socket(server);
208
209         if (!pid) {
210                 /* FIXME: this is fatal, umount? */
211                 printk(KERN_ERR "smb_retry: no connection process\n");
212                 server->state = CONN_RETRIED;
213                 goto out;
214         }
215
216         /*
217          * Change state so that only one retry per server will be started.
218          */
219         server->state = CONN_RETRYING;
220
221         /*
222          * Note: use the "priv" flag, as a user process may need to reconnect.
223          */
224         result = kill_pid(pid, SIGUSR1, 1);
225         if (result) {
226                 /* FIXME: this is most likely fatal, umount? */
227                 printk(KERN_ERR "smb_retry: signal failed [%d]\n", result);
228                 goto out;
229         }
230         VERBOSE("signalled pid %d\n", pid_nr(pid));
231
232         /* FIXME: The retried requests should perhaps get a "time boost". */
233
234 out:
235         put_pid(pid);
236         return result;
237 }
238
239 /*
240  * Currently handles lockingX packets.
241  */
242 static void smbiod_handle_request(struct smb_sb_info *server)
243 {
244         PARANOIA("smbiod got a request ... and we don't implement oplocks!\n");
245         server->rstate = SMB_RECV_DROP;
246 }
247
248 /*
249  * Do some IO for one server.
250  */
251 static void smbiod_doio(struct smb_sb_info *server)
252 {
253         int result;
254         int maxwork = 7;
255
256         if (server->state != CONN_VALID)
257                 goto out;
258
259         do {
260                 result = smb_request_recv(server);
261                 if (result < 0) {
262                         server->state = CONN_INVALID;
263                         smbiod_retry(server);
264                         goto out;       /* reconnecting is slow */
265                 } else if (server->rstate == SMB_RECV_REQUEST)
266                         smbiod_handle_request(server);
267         } while (result > 0 && maxwork-- > 0);
268
269         /*
270          * If there is more to read then we want to be sure to wake up again.
271          */
272         if (server->state != CONN_VALID)
273                 goto out;
274         if (smb_recv_available(server) > 0)
275                 set_bit(SMBIOD_DATA_READY, &smbiod_flags);
276
277         do {
278                 result = smb_request_send_server(server);
279                 if (result < 0) {
280                         server->state = CONN_INVALID;
281                         smbiod_retry(server);
282                         goto out;       /* reconnecting is slow */
283                 }
284         } while (result > 0);
285
286         /*
287          * If the last request was not sent out we want to wake up again.
288          */
289         if (!list_empty(&server->xmitq))
290                 set_bit(SMBIOD_DATA_READY, &smbiod_flags);
291
292 out:
293         return;
294 }
295
296 /*
297  * smbiod kernel thread
298  */
299 static int smbiod(void *unused)
300 {
301         VERBOSE("SMB Kernel thread starting (%d) ...\n", current->pid);
302
303         for (;;) {
304                 struct smb_sb_info *server;
305                 struct list_head *pos, *n;
306
307                 /* FIXME: Use poll? */
308                 wait_event_interruptible(smbiod_wait,
309                          test_bit(SMBIOD_DATA_READY, &smbiod_flags));
310                 if (signal_pending(current)) {
311                         spin_lock(&servers_lock);
312                         smbiod_state = SMBIOD_DEAD;
313                         spin_unlock(&servers_lock);
314                         break;
315                 }
316
317                 clear_bit(SMBIOD_DATA_READY, &smbiod_flags);
318
319                 spin_lock(&servers_lock);
320                 if (list_empty(&smb_servers)) {
321                         smbiod_state = SMBIOD_DEAD;
322                         spin_unlock(&servers_lock);
323                         break;
324                 }
325
326                 list_for_each_safe(pos, n, &smb_servers) {
327                         server = list_entry(pos, struct smb_sb_info, entry);
328                         VERBOSE("checking server %p\n", server);
329
330                         if (server->state == CONN_VALID) {
331                                 spin_unlock(&servers_lock);
332
333                                 smb_lock_server(server);
334                                 smbiod_doio(server);
335                                 smb_unlock_server(server);
336
337                                 spin_lock(&servers_lock);
338                         }
339                 }
340                 spin_unlock(&servers_lock);
341         }
342
343         VERBOSE("SMB Kernel thread exiting (%d) ...\n", current->pid);
344         module_put_and_exit(0);
345 }