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