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 }