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/smp_lock.h>
  20 #include <linux/module.h>
  21 #include <linux/net.h>
  22 #include <linux/kthread.h>
  23 #include <net/ip.h>
  24
  25 #include <linux/smb_fs.h>
  26 #include <linux/smbno.h>
  27 #include <linux/smb_mount.h>
  28
  29 #include <asm/system.h>
  30 #include <asm/uaccess.h>
  31
  32 #include "smb_debug.h"
  33 #include "request.h"
  34 #include "proto.h"
  35
  36 enum smbiod_state {
  37         SMBIOD_DEAD,
  38         SMBIOD_STARTING,
  39         SMBIOD_RUNNING,
  40 };
  41
  42 static enum smbiod_state smbiod_state = SMBIOD_DEAD;
  43 static struct task_struct *smbiod_thread;
  44 static DECLARE_WAIT_QUEUE_HEAD(smbiod_wait);
  45 static LIST_HEAD(smb_servers);
  46 static DEFINE_SPINLOCK(servers_lock);
  47
  48 #define SMBIOD_DATA_READY       (1<<0)
  49 static long smbiod_flags;
  50
  51 static int smbiod(void *);
  52 static int smbiod_start(void);
  53
  54 /*
  55  * called when there's work for us to do
  56  */
  57 void smbiod_wake_up(void)
  58 {
  59         if (smbiod_state == SMBIOD_DEAD)
  60                 return;
  61         set_bit(SMBIOD_DATA_READY, &smbiod_flags);
  62         wake_up_interruptible(&smbiod_wait);
  63 }
  64
  65 /*
  66  * start smbiod if none is running
  67  */
  68 static int smbiod_start(void)
  69 {
  70         struct task_struct *tsk;
  71         int err = 0;
  72
  73         if (smbiod_state != SMBIOD_DEAD)
  74                 return 0;
  75         smbiod_state = SMBIOD_STARTING;
  76         __module_get(THIS_MODULE);
  77         spin_unlock(&servers_lock);
  78         tsk = kthread_run(smbiod, NULL, "smbiod");
  79         if (IS_ERR(tsk)) {
  80                 err = PTR_ERR(tsk);
  81                 module_put(THIS_MODULE);
  82         }
  83
  84         spin_lock(&servers_lock);
  85         if (err < 0) {
  86                 smbiod_state = SMBIOD_DEAD;
  87                 smbiod_thread = NULL;
  88         } else {
  89                 smbiod_state = SMBIOD_RUNNING;
  90                 smbiod_thread = tsk;
  91         }
  92         return err;
  93 }
  94
  95 /*
  96  * register a server & start smbiod if necessary
  97  */
  98 int smbiod_register_server(struct smb_sb_info *server)
  99 {
 100         int ret;
 101         spin_lock(&servers_lock);
 102         list_add(&server->entry, &smb_servers);
 103         VERBOSE("%p\n", server);
 104         ret = smbiod_start();
 105         spin_unlock(&servers_lock);
 106         return ret;
 107 }
 108
 109 /*
 110  * Unregister a server
 111  * Must be called with the server lock held.
 112  */
 113 void smbiod_unregister_server(struct smb_sb_info *server)
 114 {
 115         spin_lock(&servers_lock);
 116         list_del_init(&server->entry);
 117         VERBOSE("%p\n", server);
 118         spin_unlock(&servers_lock);
 119
 120         smbiod_wake_up();
 121         smbiod_flush(server);
 122 }
 123
 124 void smbiod_flush(struct smb_sb_info *server)
 125 {
 126         struct list_head *tmp, *n;
 127         struct smb_request *req;
 128
 129         list_for_each_safe(tmp, n, &server->xmitq) {
 130                 req = list_entry(tmp, struct smb_request, rq_queue);
 131                 req->rq_errno = -EIO;
 132                 list_del_init(&req->rq_queue);
 133                 smb_rput(req);
 134                 wake_up_interruptible(&req->rq_wait);
 135         }
 136         list_for_each_safe(tmp, n, &server->recvq) {
 137                 req = list_entry(tmp, struct smb_request, rq_queue);
 138                 req->rq_errno = -EIO;
 139                 list_del_init(&req->rq_queue);
 140                 smb_rput(req);
 141                 wake_up_interruptible(&req->rq_wait);
 142         }
 143 }
 144
 145 /*
 146  * Wake up smbmount and make it reconnect to the server.
 147  * This must be called with the server locked.
 148  *
 149  * FIXME: add smbconnect version to this
 150  */
 151 int smbiod_retry(struct smb_sb_info *server)
 152 {
 153         struct list_head *head;
 154         struct smb_request *req;
 155         struct pid *pid = get_pid(server->conn_pid);
 156         int result = 0;
 157
 158         VERBOSE("state: %d\n", server->state);
 159         if (server->state == CONN_VALID || server->state == CONN_RETRYING)
 160                 goto out;
 161
 162         smb_invalidate_inodes(server);
 163
 164         /*
 165          * Some requests are meaningless after a retry, so we abort them.
 166          * One example are all requests using 'fileid' since the files are
 167          * closed on retry.
 168          */
 169         head = server->xmitq.next;
 170         while (head != &server->xmitq) {
 171                 req = list_entry(head, struct smb_request, rq_queue);
 172                 head = head->next;
 173
 174                 req->rq_bytes_sent = 0;
 175                 if (req->rq_flags & SMB_REQ_NORETRY) {
 176                         VERBOSE("aborting request %p on xmitq\n", req);
 177                         req->rq_errno = -EIO;
 178                         list_del_init(&req->rq_queue);
 179                         smb_rput(req);
 180                         wake_up_interruptible(&req->rq_wait);
 181                 }
 182         }
 183
 184         /*
 185          * FIXME: test the code for retrying request we already sent
 186          */
 187         head = server->recvq.next;
 188         while (head != &server->recvq) {
 189                 req = list_entry(head, struct smb_request, rq_queue);
 190                 head = head->next;
 191 #if 0
 192                 if (req->rq_flags & SMB_REQ_RETRY) {
 193                         /* must move the request to the xmitq */
 194                         VERBOSE("retrying request %p on recvq\n", req);
 195                         list_move(&req->rq_queue, &server->xmitq);
 196                         continue;
 197                 }
 198 #endif
 199
 200                 VERBOSE("aborting request %p on recvq\n", req);
 201                 /* req->rq_rcls = ???; */ /* FIXME: set smb error code too? */
 202                 req->rq_errno = -EIO;
 203                 list_del_init(&req->rq_queue);
 204                 smb_rput(req);
 205                 wake_up_interruptible(&req->rq_wait);
 206         }
 207
 208         smb_close_socket(server);
 209
 210         if (pid == 0) {
 211                 /* FIXME: this is fatal, umount? */
 212                 printk(KERN_ERR "smb_retry: no connection process\n");
 213                 server->state = CONN_RETRIED;
 214                 goto out;
 215         }
 216
 217         /*
 218          * Change state so that only one retry per server will be started.
 219          */
 220         server->state = CONN_RETRYING;
 221
 222         /*
 223          * Note: use the "priv" flag, as a user process may need to reconnect.
 224          */
 225         result = kill_pid(pid, SIGUSR1, 1);
 226         if (result) {
 227                 /* FIXME: this is most likely fatal, umount? */
 228                 printk(KERN_ERR "smb_retry: signal failed [%d]\n", result);
 229                 goto out;
 230         }
 231         VERBOSE("signalled pid %d\n", pid);
 232
 233         /* FIXME: The retried requests should perhaps get a "time boost". */
 234
 235 out:
 236         put_pid(pid);
 237         return result;
 238 }
 239
 240 /*
 241  * Currently handles lockingX packets.
 242  */
 243 static void smbiod_handle_request(struct smb_sb_info *server)
 244 {
 245         PARANOIA("smbiod got a request ... and we don't implement oplocks!\n");
 246         server->rstate = SMB_RECV_DROP;
 247 }
 248
 249 /*
 250  * Do some IO for one server.
 251  */
 252 static void smbiod_doio(struct smb_sb_info *server)
 253 {
 254         int result;
 255         int maxwork = 7;
 256
 257         if (server->state != CONN_VALID)
 258                 goto out;
 259
 260         do {
 261                 result = smb_request_recv(server);
 262                 if (result < 0) {
 263                         server->state = CONN_INVALID;
 264                         smbiod_retry(server);
 265                         goto out;       /* reconnecting is slow */
 266                 } else if (server->rstate == SMB_RECV_REQUEST)
 267                         smbiod_handle_request(server);
 268         } while (result > 0 && maxwork-- > 0);
 269
 270         /*
 271          * If there is more to read then we want to be sure to wake up again.
 272          */
 273         if (server->state != CONN_VALID)
 274                 goto out;
 275         if (smb_recv_available(server) > 0)
 276                 set_bit(SMBIOD_DATA_READY, &smbiod_flags);
 277
 278         do {
 279                 result = smb_request_send_server(server);
 280                 if (result < 0) {
 281                         server->state = CONN_INVALID;
 282                         smbiod_retry(server);
 283                         goto out;       /* reconnecting is slow */
 284                 }
 285         } while (result > 0);
 286
 287         /*
 288          * If the last request was not sent out we want to wake up again.
 289          */
 290         if (!list_empty(&server->xmitq))
 291                 set_bit(SMBIOD_DATA_READY, &smbiod_flags);
 292
 293 out:
 294         return;
 295 }
 296
 297 /*
 298  * smbiod kernel thread
 299  */
 300 static int smbiod(void *unused)
 301 {
 302         allow_signal(SIGKILL);
 303
 304         VERBOSE("SMB Kernel thread starting (%d) ...\n", current->pid);
 305
 306         for (;;) {
 307                 struct smb_sb_info *server;
 308                 struct list_head *pos, *n;
 309
 310                 /* FIXME: Use poll? */
 311                 wait_event_interruptible(smbiod_wait,
 312                          test_bit(SMBIOD_DATA_READY, &smbiod_flags));
 313                 if (signal_pending(current)) {
 314                         spin_lock(&servers_lock);
 315                         smbiod_state = SMBIOD_DEAD;
 316                         spin_unlock(&servers_lock);
 317                         break;
 318                 }
 319
 320                 clear_bit(SMBIOD_DATA_READY, &smbiod_flags);
 321
 322                 spin_lock(&servers_lock);
 323                 if (list_empty(&smb_servers)) {
 324                         smbiod_state = SMBIOD_DEAD;
 325                         spin_unlock(&servers_lock);
 326                         break;
 327                 }
 328
 329                 list_for_each_safe(pos, n, &smb_servers) {
 330                         server = list_entry(pos, struct smb_sb_info, entry);
 331                         VERBOSE("checking server %p\n", server);
 332
 333                         if (server->state == CONN_VALID) {
 334                                 spin_unlock(&servers_lock);
 335
 336                                 smb_lock_server(server);
 337                                 smbiod_doio(server);
 338                                 smb_unlock_server(server);
 339
 340                                 spin_lock(&servers_lock);
 341                         }
 342                 }
 343                 spin_unlock(&servers_lock);
 344         }
 345
 346         VERBOSE("SMB Kernel thread exiting (%d) ...\n", current->pid);
 347         module_put_and_exit(0);
 348 }