drivers/staging/pohmelfs/net.c

   1 /*
   2  * 2007+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
   3  * All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/fsnotify.h>
  17 #include <linux/jhash.h>
  18 #include <linux/in.h>
  19 #include <linux/in6.h>
  20 #include <linux/kthread.h>
  21 #include <linux/pagemap.h>
  22 #include <linux/poll.h>
  23 #include <linux/swap.h>
  24 #include <linux/syscalls.h>
  25 #include <linux/vmalloc.h>
  26
  27 #include "netfs.h"
  28
  29 static int pohmelfs_ftrans_size = 10240;
  30 static u32 *pohmelfs_ftrans;
  31
  32 int pohmelfs_ftrans_init(void)
  33 {
  34         pohmelfs_ftrans = vmalloc(pohmelfs_ftrans_size * 4);
  35         if (!pohmelfs_ftrans)
  36                 return -ENOMEM;
  37
  38         return 0;
  39 }
  40
  41 void pohmelfs_ftrans_exit(void)
  42 {
  43         vfree(pohmelfs_ftrans);
  44 }
  45
  46 void pohmelfs_ftrans_clean(u64 id)
  47 {
  48         if (pohmelfs_ftrans) {
  49                 u32 i = id & 0xffffffff;
  50                 int idx = i % pohmelfs_ftrans_size;
  51
  52                 pohmelfs_ftrans[idx] = 0;
  53         }
  54 }
  55
  56 void pohmelfs_ftrans_update(u64 id)
  57 {
  58         if (pohmelfs_ftrans) {
  59                 u32 i = id & 0xffffffff;
  60                 int idx = i % pohmelfs_ftrans_size;
  61
  62                 pohmelfs_ftrans[idx] = i;
  63         }
  64 }
  65
  66 int pohmelfs_ftrans_check(u64 id)
  67 {
  68         if (pohmelfs_ftrans) {
  69                 u32 i = id & 0xffffffff;
  70                 int idx = i % pohmelfs_ftrans_size;
  71
  72                 return (pohmelfs_ftrans[idx] == i);
  73         }
  74
  75         return -1;
  76 }
  77
  78 /*
  79  * Async machinery lives here.
  80  * All commands being sent to server do _not_ require sync reply,
  81  * instead, if it is really needed, like readdir or readpage, caller
  82  * sleeps waiting for data, which will be placed into provided buffer
  83  * and caller will be awakened.
  84  *
  85  * Every command response can come without some listener. For example
  86  * readdir response will add new objects into cache without appropriate
  87  * request from userspace. This is used in cache coherency.
  88  *
  89  * If object is not found for given data, it is discarded.
  90  *
  91  * All requests are received by dedicated kernel thread.
  92  */
  93
  94 /*
  95  * Basic network sending/receiving functions.
  96  * Blocked mode is used.
  97  */
  98 static int netfs_data_recv(struct netfs_state *st, void *buf, u64 size)
  99 {
 100         struct msghdr msg;
 101         struct kvec iov;
 102         int err;
 103
 104         BUG_ON(!size);
 105
 106         iov.iov_base = buf;
 107         iov.iov_len = size;
 108
 109         msg.msg_iov = (struct iovec *)&iov;
 110         msg.msg_iovlen = 1;
 111         msg.msg_name = NULL;
 112         msg.msg_namelen = 0;
 113         msg.msg_control = NULL;
 114         msg.msg_controllen = 0;
 115         msg.msg_flags = MSG_DONTWAIT;
 116
 117         err = kernel_recvmsg(st->socket, &msg, &iov, 1, iov.iov_len,
 118                         msg.msg_flags);
 119         if (err <= 0) {
 120                 printk("%s: failed to recv data: size: %llu, err: %d.\n", __func__, size, err);
 121                 if (err == 0)
 122                         err = -ECONNRESET;
 123         }
 124
 125         return err;
 126 }
 127
 128 static int pohmelfs_data_recv(struct netfs_state *st, void *data, unsigned int size)
 129 {
 130         unsigned int revents = 0;
 131         unsigned int err_mask = POLLERR | POLLHUP | POLLRDHUP;
 132         unsigned int mask = err_mask | POLLIN;
 133         int err = 0;
 134
 135         while (size && !err) {
 136                 revents = netfs_state_poll(st);
 137
 138                 if (!(revents & mask)) {
 139                         DEFINE_WAIT(wait);
 140
 141                         for (;;) {
 142                                 prepare_to_wait(&st->thread_wait, &wait, TASK_INTERRUPTIBLE);
 143                                 if (kthread_should_stop())
 144                                         break;
 145
 146                                 revents = netfs_state_poll(st);
 147
 148                                 if (revents & mask)
 149                                         break;
 150
 151                                 if (signal_pending(current))
 152                                         break;
 153
 154                                 schedule();
 155                                 continue;
 156                         }
 157                         finish_wait(&st->thread_wait, &wait);
 158                 }
 159
 160                 err = 0;
 161                 netfs_state_lock(st);
 162                 if (st->socket && (st->read_socket == st->socket) && (revents & POLLIN)) {
 163                         err = netfs_data_recv(st, data, size);
 164                         if (err > 0) {
 165                                 data += err;
 166                                 size -= err;
 167                                 err = 0;
 168                         } else if (err == 0)
 169                                 err = -ECONNRESET;
 170                 }
 171
 172                 if (revents & err_mask) {
 173                         printk("%s: revents: %x, socket: %p, size: %u, err: %d.\n",
 174                                         __func__, revents, st->socket, size, err);
 175                         err = -ECONNRESET;
 176                 }
 177                 netfs_state_unlock(st);
 178
 179                 if (err < 0) {
 180                         if (netfs_state_trylock_send(st)) {
 181                                 netfs_state_exit(st);
 182                                 err = netfs_state_init(st);
 183                                 if (!err)
 184                                         err = -EAGAIN;
 185                                 netfs_state_unlock_send(st);
 186                         } else {
 187                                 st->need_reset = 1;
 188                         }
 189                 }
 190
 191                 if (kthread_should_stop())
 192                         err = -ENODEV;
 193
 194                 if (err)
 195                         printk("%s: socket: %p, read_socket: %p, revents: %x, rev_error: %d, "
 196                                         "should_stop: %d, size: %u, err: %d.\n",
 197                                 __func__, st->socket, st->read_socket,
 198                                 revents, revents & err_mask, kthread_should_stop(), size, err);
 199         }
 200
 201         return err;
 202 }
 203
 204 int pohmelfs_data_recv_and_check(struct netfs_state *st, void *data, unsigned int size)
 205 {
 206         struct netfs_cmd *cmd = &st->cmd;
 207         int err;
 208
 209         err = pohmelfs_data_recv(st, data, size);
 210         if (err)
 211                 return err;
 212
 213         return pohmelfs_crypto_process_input_data(&st->eng, cmd->iv, data, NULL, size);
 214 }
 215
 216 /*
 217  * Polling machinery.
 218  */
 219
 220 struct netfs_poll_helper
 221 {
 222         poll_table              pt;
 223         struct netfs_state      *st;
 224 };
 225
 226 static int netfs_queue_wake(wait_queue_t *wait, unsigned mode, int sync, void *key)
 227 {
 228         struct netfs_state *st = container_of(wait, struct netfs_state, wait);
 229
 230         wake_up(&st->thread_wait);
 231         return 1;
 232 }
 233
 234 static void netfs_queue_func(struct file *file, wait_queue_head_t *whead,
 235                                  poll_table *pt)
 236 {
 237         struct netfs_state *st = container_of(pt, struct netfs_poll_helper, pt)->st;
 238
 239         st->whead = whead;
 240         init_waitqueue_func_entry(&st->wait, netfs_queue_wake);
 241         add_wait_queue(whead, &st->wait);
 242 }
 243
 244 static void netfs_poll_exit(struct netfs_state *st)
 245 {
 246         if (st->whead) {
 247                 remove_wait_queue(st->whead, &st->wait);
 248                 st->whead = NULL;
 249         }
 250 }
 251
 252 static int netfs_poll_init(struct netfs_state *st)
 253 {
 254         struct netfs_poll_helper ph;
 255
 256         ph.st = st;
 257         init_poll_funcptr(&ph.pt, &netfs_queue_func);
 258
 259         st->socket->ops->poll(NULL, st->socket, &ph.pt);
 260         return 0;
 261 }
 262
 263 /*
 264  * Get response for readpage command. We search inode and page in its mapping
 265  * and copy data into. If it was async request, then we queue page into shared
 266  * data and wakeup listener, who will copy it to userspace.
 267  *
 268  * There is a work in progress of allowing to call copy_to_user() directly from
 269  * async receiving kernel thread.
 270  */
 271 static int pohmelfs_read_page_response(struct netfs_state *st)
 272 {
 273         struct pohmelfs_sb *psb = st->psb;
 274         struct netfs_cmd *cmd = &st->cmd;
 275         struct inode *inode;
 276         struct page *page;
 277         int err = 0;
 278
 279         if (cmd->size > PAGE_CACHE_SIZE) {
 280                 err = -EINVAL;
 281                 goto err_out_exit;
 282         }
 283
 284         inode = ilookup(st->psb->sb, cmd->id);
 285         if (!inode) {
 286                 printk("%s: failed to find inode: id: %llu.\n", __func__, cmd->id);
 287                 err = -ENOENT;
 288                 goto err_out_exit;
 289         }
 290
 291         page = find_get_page(inode->i_mapping, cmd->start >> PAGE_CACHE_SHIFT);
 292         if (!page || !PageLocked(page)) {
 293                 printk("%s: failed to find/lock page: page: %p, id: %llu, start: %llu, index: %llu.\n",
 294                                 __func__, page, cmd->id, cmd->start, cmd->start >> PAGE_CACHE_SHIFT);
 295
 296                 while (cmd->size) {
 297                         unsigned int sz = min(cmd->size, st->size);
 298
 299                         err = pohmelfs_data_recv(st, st->data, sz);
 300                         if (err)
 301                                 break;
 302
 303                         cmd->size -= sz;
 304                 }
 305
 306                 err = -ENODEV;
 307                 if (page)
 308                         goto err_out_page_put;
 309                 goto err_out_put;
 310         }
 311
 312         if (cmd->size) {
 313                 void *addr;
 314
 315                 addr = kmap(page);
 316                 err = pohmelfs_data_recv(st, addr, cmd->size);
 317                 kunmap(page);
 318
 319                 if (err)
 320                         goto err_out_page_unlock;
 321         }
 322
 323         dprintk("%s: page: %p, start: %llu, size: %u, locked: %d.\n",
 324                 __func__, page, cmd->start, cmd->size, PageLocked(page));
 325
 326         SetPageChecked(page);
 327         if ((psb->hash_string || psb->cipher_string) && psb->perform_crypto && cmd->size) {
 328                 err = pohmelfs_crypto_process_input_page(&st->eng, page, cmd->size, cmd->iv);
 329                 if (err < 0)
 330                         goto err_out_page_unlock;
 331         } else {
 332                 SetPageUptodate(page);
 333                 unlock_page(page);
 334                 page_cache_release(page);
 335         }
 336
 337         pohmelfs_put_inode(POHMELFS_I(inode));
 338         wake_up(&st->psb->wait);
 339
 340         return 0;
 341
 342 err_out_page_unlock:
 343         SetPageError(page);
 344         unlock_page(page);
 345 err_out_page_put:
 346         page_cache_release(page);
 347 err_out_put:
 348         pohmelfs_put_inode(POHMELFS_I(inode));
 349 err_out_exit:
 350         wake_up(&st->psb->wait);
 351         return err;
 352 }
 353
 354 static int pohmelfs_check_name(struct pohmelfs_inode *parent, struct qstr *str,
 355                 struct netfs_inode_info *info)
 356 {
 357         struct inode *inode;
 358         struct pohmelfs_name *n;
 359         int err = 0;
 360         u64 ino = 0;
 361
 362         mutex_lock(&parent->offset_lock);
 363         n = pohmelfs_search_hash(parent, str->hash);
 364         if (n)
 365                 ino = n->ino;
 366         mutex_unlock(&parent->offset_lock);
 367
 368         if (!ino)
 369                 goto out;
 370
 371         inode = ilookup(parent->vfs_inode.i_sb, ino);
 372         if (!inode)
 373                 goto out;
 374
 375         dprintk("%s: parent: %llu, inode: %llu.\n", __func__, parent->ino, ino);
 376
 377         pohmelfs_fill_inode(inode, info);
 378         pohmelfs_put_inode(POHMELFS_I(inode));
 379         err = -EEXIST;
 380 out:
 381         return err;
 382 }
 383
 384 /*
 385  * Readdir response from server. If special field is set, we wakeup
 386  * listener (readdir() call), which will copy data to userspace.
 387  */
 388 static int pohmelfs_readdir_response(struct netfs_state *st)
 389 {
 390         struct inode *inode;
 391         struct netfs_cmd *cmd = &st->cmd;
 392         struct netfs_inode_info *info;
 393         struct pohmelfs_inode *parent = NULL, *npi;
 394         int err = 0, last = cmd->ext;
 395         struct qstr str;
 396
 397         if (cmd->size > st->size)
 398                 return -EINVAL;
 399
 400         inode = ilookup(st->psb->sb, cmd->id);
 401         if (!inode) {
 402                 printk("%s: failed to find inode: id: %llu.\n", __func__, cmd->id);
 403                 return -ENOENT;
 404         }
 405         parent = POHMELFS_I(inode);
 406
 407         if (!cmd->size && cmd->start) {
 408                 err = -cmd->start;
 409                 goto out;
 410         }
 411
 412         if (cmd->size) {
 413                 char *name;
 414
 415                 err = pohmelfs_data_recv_and_check(st, st->data, cmd->size);
 416                 if (err)
 417                         goto err_out_put;
 418
 419                 info = (struct netfs_inode_info *)(st->data);
 420
 421                 name = (char *)(info + 1);
 422                 str.len = cmd->size - sizeof(struct netfs_inode_info) - 1 - cmd->cpad;
 423                 name[str.len] = 0;
 424                 str.name = name;
 425                 str.hash = jhash(str.name, str.len, 0);
 426
 427                 netfs_convert_inode_info(info);
 428
 429                 if (parent) {
 430                         err = pohmelfs_check_name(parent, &str, info);
 431                         if (err) {
 432                                 if (err == -EEXIST)
 433                                         err = 0;
 434                                 goto out;
 435                         }
 436                 }
 437
 438                 info->ino = cmd->start;
 439                 if (!info->ino)
 440                         info->ino = pohmelfs_new_ino(st->psb);
 441
 442                 dprintk("%s: parent: %llu, ino: %llu, name: '%s', hash: %x, len: %u, mode: %o.\n",
 443                                 __func__, parent->ino, info->ino, str.name, str.hash, str.len,
 444                                 info->mode);
 445
 446                 npi = pohmelfs_new_inode(st->psb, parent, &str, info, 0);
 447                 if (IS_ERR(npi)) {
 448                         err = PTR_ERR(npi);
 449
 450                         if (err != -EEXIST)
 451                                 goto err_out_put;
 452                 } else {
 453                         set_bit(NETFS_INODE_REMOTE_SYNCED, &npi->state);
 454                         clear_bit(NETFS_INODE_OWNED, &npi->state);
 455                 }
 456         }
 457 out:
 458         if (last) {
 459                 set_bit(NETFS_INODE_REMOTE_DIR_SYNCED, &parent->state);
 460                 set_bit(NETFS_INODE_REMOTE_SYNCED, &parent->state);
 461                 wake_up(&st->psb->wait);
 462         }
 463         pohmelfs_put_inode(parent);
 464
 465         return err;
 466
 467 err_out_put:
 468         clear_bit(NETFS_INODE_REMOTE_DIR_SYNCED, &parent->state);
 469         printk("%s: parent: %llu, ino: %llu, cmd_id: %llu.\n", __func__, parent->ino, cmd->start, cmd->id);
 470         pohmelfs_put_inode(parent);
 471         wake_up(&st->psb->wait);
 472         return err;
 473 }
 474
 475 /*
 476  * Lookup command response.
 477  * It searches for inode to be looked at (if it exists) and substitutes
 478  * its inode information (size, permission, mode and so on), if inode does
 479  * not exist, new one will be created and inserted into caches.
 480  */
 481 static int pohmelfs_lookup_response(struct netfs_state *st)
 482 {
 483         struct inode *inode = NULL;
 484         struct netfs_cmd *cmd = &st->cmd;
 485         struct netfs_inode_info *info;
 486         struct pohmelfs_inode *parent = NULL, *npi;
 487         int err = -EINVAL;
 488         char *name;
 489
 490         inode = ilookup(st->psb->sb, cmd->id);
 491         if (!inode) {
 492                 printk("%s: lookup response: id: %llu, start: %llu, size: %u.\n",
 493                                 __func__, cmd->id, cmd->start, cmd->size);
 494                 err = -ENOENT;
 495                 goto err_out_exit;
 496         }
 497         parent = POHMELFS_I(inode);
 498
 499         if (!cmd->size) {
 500                 err = -cmd->start;
 501                 goto err_out_put;
 502         }
 503
 504         if (cmd->size < sizeof(struct netfs_inode_info)) {
 505                 printk("%s: broken lookup response: id: %llu, start: %llu, size: %u.\n",
 506                                 __func__, cmd->id, cmd->start, cmd->size);
 507                 err = -EINVAL;
 508                 goto err_out_put;
 509         }
 510
 511         err = pohmelfs_data_recv_and_check(st, st->data, cmd->size);
 512         if (err)
 513                 goto err_out_put;
 514
 515         info = (struct netfs_inode_info *)(st->data);
 516         name = (char *)(info + 1);
 517
 518         netfs_convert_inode_info(info);
 519
 520         info->ino = cmd->start;
 521         if (!info->ino)
 522                 info->ino = pohmelfs_new_ino(st->psb);
 523
 524         dprintk("%s: parent: %llu, ino: %llu, name: '%s', start: %llu.\n",
 525                         __func__, parent->ino, info->ino, name, cmd->start);
 526
 527         if (cmd->start)
 528                 npi = pohmelfs_new_inode(st->psb, parent, NULL, info, 0);
 529         else {
 530                 struct qstr str;
 531
 532                 str.name = name;
 533                 str.len = cmd->size - sizeof(struct netfs_inode_info) - 1 - cmd->cpad;
 534                 str.hash = jhash(name, str.len, 0);
 535
 536                 npi = pohmelfs_new_inode(st->psb, parent, &str, info, 0);
 537         }
 538         if (IS_ERR(npi)) {
 539                 err = PTR_ERR(npi);
 540
 541                 if (err != -EEXIST)
 542                         goto err_out_put;
 543         } else {
 544                 set_bit(NETFS_INODE_REMOTE_SYNCED, &npi->state);
 545                 clear_bit(NETFS_INODE_OWNED, &npi->state);
 546         }
 547
 548         clear_bit(NETFS_COMMAND_PENDING, &parent->state);
 549         pohmelfs_put_inode(parent);
 550
 551         wake_up(&st->psb->wait);
 552
 553         return 0;
 554
 555 err_out_put:
 556         pohmelfs_put_inode(parent);
 557 err_out_exit:
 558         clear_bit(NETFS_COMMAND_PENDING, &parent->state);
 559         wake_up(&st->psb->wait);
 560         printk("%s: inode: %p, id: %llu, start: %llu, size: %u, err: %d.\n",
 561                         __func__, inode, cmd->id, cmd->start, cmd->size, err);
 562         return err;
 563 }
 564
 565 /*
 566  * Create response, just marks local inode as 'created', so that writeback
 567  * for any of its children (or own) would not try to sync it again.
 568  */
 569 static int pohmelfs_create_response(struct netfs_state *st)
 570 {
 571         struct inode *inode;
 572         struct netfs_cmd *cmd = &st->cmd;
 573         struct pohmelfs_inode *pi;
 574
 575         inode = ilookup(st->psb->sb, cmd->id);
 576         if (!inode) {
 577                 printk("%s: failed to find inode: id: %llu, start: %llu.\n",
 578                                 __func__, cmd->id, cmd->start);
 579                 goto err_out_exit;
 580         }
 581
 582         pi = POHMELFS_I(inode);
 583
 584         /*
 585          * To lock or not to lock?
 586          * We actually do not care if it races...
 587          */
 588         if (cmd->start)
 589                 make_bad_inode(inode);
 590         set_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state);
 591
 592         pohmelfs_put_inode(pi);
 593
 594         wake_up(&st->psb->wait);
 595         return 0;
 596
 597 err_out_exit:
 598         wake_up(&st->psb->wait);
 599         return -ENOENT;
 600 }
 601
 602 /*
 603  * Object remove response. Just says that remove request has been received.
 604  * Used in cache coherency protocol.
 605  */
 606 static int pohmelfs_remove_response(struct netfs_state *st)
 607 {
 608         struct netfs_cmd *cmd = &st->cmd;
 609         int err;
 610
 611         err = pohmelfs_data_recv_and_check(st, st->data, cmd->size);
 612         if (err)
 613                 return err;
 614
 615         dprintk("%s: parent: %llu, path: '%s'.\n", __func__, cmd->id, (char *)st->data);
 616
 617         return 0;
 618 }
 619
 620 /*
 621  * Transaction reply processing.
 622  *
 623  * Find transaction based on its generation number, bump its reference counter,
 624  * so that none could free it under us, drop from the trees and lists and
 625  * drop reference counter. When it hits zero (when all destinations replied
 626  * and all timeout handled by async scanning code), completion will be called
 627  * and transaction will be freed.
 628  */
 629 static int pohmelfs_transaction_response(struct netfs_state *st)
 630 {
 631         struct netfs_trans_dst *dst;
 632         struct netfs_trans *t = NULL;
 633         struct netfs_cmd *cmd = &st->cmd;
 634         short err = (signed)cmd->ext;
 635
 636         mutex_lock(&st->trans_lock);
 637         dst = netfs_trans_search(st, cmd->start);
 638         if (dst) {
 639                 netfs_trans_remove_nolock(dst, st);
 640                 t = dst->trans;
 641
 642                 pohmelfs_ftrans_update(cmd->start);
 643         }
 644         mutex_unlock(&st->trans_lock);
 645
 646         if (!t) {
 647                 int check = pohmelfs_ftrans_check(cmd->start);
 648                 printk("%s: failed to find transaction: start: %llu: id: %llu, size: %u, ext: %u, double: %d.\n",
 649                                 __func__, cmd->start, cmd->id, cmd->size, cmd->ext, check);
 650                 err = -EINVAL;
 651                 goto out;
 652         }
 653
 654         t->result = err;
 655         netfs_trans_drop_dst_nostate(dst);
 656
 657 out:
 658         wake_up(&st->psb->wait);
 659         return err;
 660 }
 661
 662 /*
 663  * Inode metadata cache coherency message.
 664  */
 665 static int pohmelfs_page_cache_response(struct netfs_state *st)
 666 {
 667         struct netfs_cmd *cmd = &st->cmd;
 668         struct inode *inode;
 669
 670         dprintk("%s: st: %p, id: %llu, start: %llu, size: %u.\n", __func__, st, cmd->id, cmd->start, cmd->size);
 671
 672         inode = ilookup(st->psb->sb, cmd->id);
 673         if (!inode) {
 674                 printk("%s: failed to find inode: id: %llu.\n", __func__, cmd->id);
 675                 return -ENOENT;
 676         }
 677
 678         set_bit(NETFS_INODE_NEED_FLUSH, &POHMELFS_I(inode)->state);
 679         pohmelfs_put_inode(POHMELFS_I(inode));
 680
 681         return 0;
 682 }
 683
 684 /*
 685  * Root capabilities response: export statistics
 686  * like used and available size, number of files and dirs,
 687  * permissions.
 688  */
 689 static int pohmelfs_root_cap_response(struct netfs_state *st)
 690 {
 691         struct netfs_cmd *cmd = &st->cmd;
 692         struct netfs_root_capabilities *cap;
 693         struct pohmelfs_sb *psb = st->psb;
 694
 695         if (cmd->size != sizeof(struct netfs_root_capabilities)) {
 696                 psb->flags = EPROTO;
 697                 wake_up(&psb->wait);
 698                 return -EPROTO;
 699         }
 700
 701         cap = st->data;
 702
 703         netfs_convert_root_capabilities(cap);
 704
 705         if (psb->total_size < cap->used + cap->avail)
 706                 psb->total_size = cap->used + cap->avail;
 707         if (cap->avail)
 708                 psb->avail_size = cap->avail;
 709         psb->state_flags = cap->flags;
 710
 711         if (psb->state_flags & POHMELFS_FLAGS_RO) {
 712                 psb->sb->s_flags |= MS_RDONLY;
 713                 printk(KERN_INFO "Mounting POHMELFS (%d) read-only.\n", psb->idx);
 714         }
 715
 716         if (psb->state_flags & POHMELFS_FLAGS_XATTR)
 717                 printk(KERN_INFO "Mounting POHMELFS (%d) "
 718                         "with extended attributes support.\n", psb->idx);
 719
 720         if (atomic_read(&psb->total_inodes) <= 1)
 721                 atomic_long_set(&psb->total_inodes, cap->nr_files);
 722
 723         dprintk("%s: total: %llu, avail: %llu, flags: %llx, inodes: %llu.\n",
 724                 __func__, psb->total_size, psb->avail_size, psb->state_flags, cap->nr_files);
 725
 726         psb->flags = 0;
 727         wake_up(&psb->wait);
 728         return 0;
 729 }
 730
 731 /*
 732  * Crypto capabilities of the server, where it says that
 733  * it supports or does not requested hash/cipher algorithms.
 734  */
 735 static int pohmelfs_crypto_cap_response(struct netfs_state *st)
 736 {
 737         struct netfs_cmd *cmd = &st->cmd;
 738         struct netfs_crypto_capabilities *cap;
 739         struct pohmelfs_sb *psb = st->psb;
 740         int err = 0;
 741
 742         if (cmd->size != sizeof(struct netfs_crypto_capabilities)) {
 743                 psb->flags = EPROTO;
 744                 wake_up(&psb->wait);
 745                 return -EPROTO;
 746         }
 747
 748         cap = st->data;
 749
 750         dprintk("%s: cipher '%s': %s, hash: '%s': %s.\n",
 751                         __func__,
 752                         psb->cipher_string, (cap->cipher_strlen)?"SUPPORTED":"NOT SUPPORTED",
 753                         psb->hash_string, (cap->hash_strlen)?"SUPPORTED":"NOT SUPPORTED");
 754
 755         if (!cap->hash_strlen) {
 756                 if (psb->hash_strlen && psb->crypto_fail_unsupported)
 757                         err = -ENOTSUPP;
 758                 psb->hash_strlen = 0;
 759                 kfree(psb->hash_string);
 760                 psb->hash_string = NULL;
 761         }
 762
 763         if (!cap->cipher_strlen) {
 764                 if (psb->cipher_strlen && psb->crypto_fail_unsupported)
 765                         err = -ENOTSUPP;
 766                 psb->cipher_strlen = 0;
 767                 kfree(psb->cipher_string);
 768                 psb->cipher_string = NULL;
 769         }
 770
 771         return err;
 772 }
 773
 774 /*
 775  * Capabilities handshake response.
 776  */
 777 static int pohmelfs_capabilities_response(struct netfs_state *st)
 778 {
 779         struct netfs_cmd *cmd = &st->cmd;
 780         int err = 0;
 781
 782         err = pohmelfs_data_recv(st, st->data, cmd->size);
 783         if (err)
 784                 return err;
 785
 786         switch (cmd->id) {
 787                 case POHMELFS_CRYPTO_CAPABILITIES:
 788                         return pohmelfs_crypto_cap_response(st);
 789                 case POHMELFS_ROOT_CAPABILITIES:
 790                         return pohmelfs_root_cap_response(st);
 791                 default:
 792                         break;
 793         }
 794         return -EINVAL;
 795 }
 796
 797 /*
 798  * Receiving extended attribute.
 799  * Does not work properly if received size is more than requested one,
 800  * it should not happen with current request/reply model though.
 801  */
 802 static int pohmelfs_getxattr_response(struct netfs_state *st)
 803 {
 804         struct pohmelfs_sb *psb = st->psb;
 805         struct netfs_cmd *cmd = &st->cmd;
 806         struct pohmelfs_mcache *m;
 807         short error = (signed short)cmd->ext, err;
 808         unsigned int sz, total_size;
 809
 810         m = pohmelfs_mcache_search(psb, cmd->id);
 811
 812         dprintk("%s: id: %llu, gen: %llu, err: %d.\n",
 813                 __func__, cmd->id, (m)?m->gen:0, error);
 814
 815         if (!m) {
 816                 printk("%s: failed to find getxattr cache entry: id: %llu.\n", __func__, cmd->id);
 817                 return -ENOENT;
 818         }
 819
 820         if (cmd->size) {
 821                 sz = min_t(unsigned int, cmd->size, m->size);
 822                 err = pohmelfs_data_recv_and_check(st, m->data, sz);
 823                 if (err) {
 824                         error = err;
 825                         goto out;
 826                 }
 827
 828                 m->size = sz;
 829                 total_size = cmd->size - sz;
 830
 831                 while (total_size) {
 832                         sz = min(total_size, st->size);
 833
 834                         err = pohmelfs_data_recv_and_check(st, st->data, sz);
 835                         if (err) {
 836                                 error = err;
 837                                 break;
 838                         }
 839
 840                         total_size -= sz;
 841                 }
 842         }
 843
 844 out:
 845         m->err = error;
 846         complete(&m->complete);
 847         pohmelfs_mcache_put(psb, m);
 848
 849         return error;
 850 }
 851
 852 int pohmelfs_data_lock_response(struct netfs_state *st)
 853 {
 854         struct pohmelfs_sb *psb = st->psb;
 855         struct netfs_cmd *cmd = &st->cmd;
 856         struct pohmelfs_mcache *m;
 857         short err = (signed short)cmd->ext;
 858         u64 id = cmd->id;
 859
 860         m = pohmelfs_mcache_search(psb, id);
 861
 862         dprintk("%s: id: %llu, gen: %llu, err: %d.\n",
 863                 __func__, cmd->id, (m)?m->gen:0, err);
 864
 865         if (!m) {
 866                 pohmelfs_data_recv(st, st->data, cmd->size);
 867                 printk("%s: failed to find data lock response: id: %llu.\n", __func__, cmd->id);
 868                 return -ENOENT;
 869         }
 870
 871         if (cmd->size)
 872                 err = pohmelfs_data_recv_and_check(st, &m->info, cmd->size);
 873
 874         m->err = err;
 875         complete(&m->complete);
 876         pohmelfs_mcache_put(psb, m);
 877
 878         return err;
 879 }
 880
 881 static void __inline__ netfs_state_reset(struct netfs_state *st)
 882 {
 883         netfs_state_lock_send(st);
 884         netfs_state_exit(st);
 885         netfs_state_init(st);
 886         netfs_state_unlock_send(st);
 887 }
 888
 889 /*
 890  * Main receiving function, called from dedicated kernel thread.
 891  */
 892 static int pohmelfs_recv(void *data)
 893 {
 894         int err = -EINTR;
 895         struct netfs_state *st = data;
 896         struct netfs_cmd *cmd = &st->cmd;
 897
 898         while (!kthread_should_stop()) {
 899                 /*
 900                  * If socket will be reset after this statement, then
 901                  * pohmelfs_data_recv() will just fail and loop will
 902                  * start again, so it can be done without any locks.
 903                  *
 904                  * st->read_socket is needed to prevents state machine
 905                  * breaking between this data reading and subsequent one
 906                  * in protocol specific functions during connection reset.
 907                  * In case of reset we have to read next command and do
 908                  * not expect data for old command to magically appear in
 909                  * new connection.
 910                  */
 911                 st->read_socket = st->socket;
 912                 err = pohmelfs_data_recv(st, cmd, sizeof(struct netfs_cmd));
 913                 if (err) {
 914                         msleep(1000);
 915                         continue;
 916                 }
 917
 918                 netfs_convert_cmd(cmd);
 919
 920                 dprintk("%s: cmd: %u, id: %llu, start: %llu, size: %u, "
 921                                 "ext: %u, csize: %u, cpad: %u.\n",
 922                                 __func__, cmd->cmd, cmd->id, cmd->start,
 923                                 cmd->size, cmd->ext, cmd->csize, cmd->cpad);
 924
 925                 if (cmd->csize) {
 926                         struct pohmelfs_crypto_engine *e = &st->eng;
 927
 928                         if (unlikely(cmd->csize > e->size/2)) {
 929                                 netfs_state_reset(st);
 930                                 continue;
 931                         }
 932
 933                         if (e->hash && unlikely(cmd->csize != st->psb->crypto_attached_size)) {
 934                                 dprintk("%s: cmd: cmd: %u, id: %llu, start: %llu, size: %u, "
 935                                                 "csize: %u != digest size %u.\n",
 936                                                 __func__, cmd->cmd, cmd->id, cmd->start, cmd->size,
 937                                                 cmd->csize, st->psb->crypto_attached_size);
 938                                 netfs_state_reset(st);
 939                                 continue;
 940                         }
 941
 942                         err = pohmelfs_data_recv(st, e->data, cmd->csize);
 943                         if (err) {
 944                                 netfs_state_reset(st);
 945                                 continue;
 946                         }
 947
 948 #ifdef CONFIG_POHMELFS_DEBUG
 949                         {
 950                                 unsigned int i;
 951                                 unsigned char *hash = e->data;
 952
 953                                 dprintk("%s: received hash: ", __func__);
 954                                 for (i=0; i<cmd->csize; ++i) {
 955                                         printk("%02x ", hash[i]);
 956                                 }
 957                                 printk("\n");
 958                         }
 959 #endif
 960                         cmd->size -= cmd->csize;
 961                 }
 962
 963                 /*
 964                  * This should catch protocol breakage and random garbage instead of commands.
 965                  */
 966                 if (unlikely((cmd->size > st->size) && (cmd->cmd != NETFS_XATTR_GET))) {
 967                         netfs_state_reset(st);
 968                         continue;
 969                 }
 970
 971                 switch (cmd->cmd) {
 972                         case NETFS_READ_PAGE:
 973                                 err = pohmelfs_read_page_response(st);
 974                                 break;
 975                         case NETFS_READDIR:
 976                                 err = pohmelfs_readdir_response(st);
 977                                 break;
 978                         case NETFS_LOOKUP:
 979                                 err = pohmelfs_lookup_response(st);
 980                                 break;
 981                         case NETFS_CREATE:
 982                                 err = pohmelfs_create_response(st);
 983                                 break;
 984                         case NETFS_REMOVE:
 985                                 err = pohmelfs_remove_response(st);
 986                                 break;
 987                         case NETFS_TRANS:
 988                                 err = pohmelfs_transaction_response(st);
 989                                 break;
 990                         case NETFS_PAGE_CACHE:
 991                                 err = pohmelfs_page_cache_response(st);
 992                                 break;
 993                         case NETFS_CAPABILITIES:
 994                                 err = pohmelfs_capabilities_response(st);
 995                                 break;
 996                         case NETFS_LOCK:
 997                                 err = pohmelfs_data_lock_response(st);
 998                                 break;
 999                         case NETFS_XATTR_GET:
1000                                 err = pohmelfs_getxattr_response(st);
1001                                 break;
1002                         default:
1003                                 printk("%s: wrong cmd: %u, id: %llu, start: %llu, size: %u, ext: %u.\n",
1004                                         __func__, cmd->cmd, cmd->id, cmd->start, cmd->size, cmd->ext);
1005                                 netfs_state_reset(st);
1006                                 break;
1007                 }
1008         }
1009
1010         while (!kthread_should_stop())
1011                 schedule_timeout_uninterruptible(msecs_to_jiffies(10));
1012
1013         return err;
1014 }
1015
1016 int netfs_state_init(struct netfs_state *st)
1017 {
1018         int err;
1019         struct pohmelfs_ctl *ctl = &st->ctl;
1020
1021         err = sock_create(ctl->addr.sa_family, ctl->type, ctl->proto, &st->socket);
1022         if (err) {
1023                 printk("%s: failed to create a socket: family: %d, type: %d, proto: %d, err: %d.\n",
1024                                 __func__, ctl->addr.sa_family, ctl->type, ctl->proto, err);
1025                 goto err_out_exit;
1026         }
1027
1028         st->socket->sk->sk_allocation = GFP_NOIO;
1029         st->socket->sk->sk_sndtimeo = st->socket->sk->sk_rcvtimeo = msecs_to_jiffies(60000);
1030
1031         err = kernel_connect(st->socket, (struct sockaddr *)&ctl->addr, ctl->addrlen, 0);
1032         if (err) {
1033                 printk("%s: failed to connect to server: idx: %u, err: %d.\n",
1034                                 __func__, st->psb->idx, err);
1035                 goto err_out_release;
1036         }
1037         st->socket->sk->sk_sndtimeo = st->socket->sk->sk_rcvtimeo = msecs_to_jiffies(60000);
1038
1039         err = netfs_poll_init(st);
1040         if (err)
1041                 goto err_out_release;
1042
1043         if (st->socket->ops->family == AF_INET) {
1044                 struct sockaddr_in *sin = (struct sockaddr_in *)&ctl->addr;
1045                 printk(KERN_INFO "%s: (re)connected to peer %u.%u.%u.%u:%d.\n", __func__,
1046                         NIPQUAD(sin->sin_addr.s_addr), ntohs(sin->sin_port));
1047         } else if (st->socket->ops->family == AF_INET6) {
1048                 struct sockaddr_in6 *sin = (struct sockaddr_in6 *)&ctl->addr;
1049                 printk(KERN_INFO "%s: (re)connected to peer "
1050                         "%pi6:%d",
1051                         __func__, &sin->sin6_addr, ntohs(sin->sin6_port));
1052         }
1053
1054         return 0;
1055
1056 err_out_release:
1057         sock_release(st->socket);
1058 err_out_exit:
1059         st->socket = NULL;
1060         return err;
1061 }
1062
1063 void netfs_state_exit(struct netfs_state *st)
1064 {
1065         if (st->socket) {
1066                 netfs_poll_exit(st);
1067                 st->socket->ops->shutdown(st->socket, 2);
1068
1069                 if (st->socket->ops->family == AF_INET) {
1070                         struct sockaddr_in *sin = (struct sockaddr_in *)&st->ctl.addr;
1071                         printk("%s: disconnected from peer %u.%u.%u.%u:%d.\n", __func__,
1072                                 NIPQUAD(sin->sin_addr.s_addr), ntohs(sin->sin_port));
1073                 } else if (st->socket->ops->family == AF_INET6) {
1074                         struct sockaddr_in6 *sin = (struct sockaddr_in6 *)&st->ctl.addr;
1075                         printk("%s: disconnected from peer "
1076                                 "%pi6:%d",
1077                                 __func__, &sin->sin6_addr, ntohs(sin->sin6_port));
1078                 }
1079
1080                 sock_release(st->socket);
1081                 st->socket = NULL;
1082                 st->read_socket = NULL;
1083                 st->need_reset = 0;
1084         }
1085 }
1086
1087 int pohmelfs_state_init_one(struct pohmelfs_sb *psb, struct pohmelfs_config *conf)
1088 {
1089         struct netfs_state *st = &conf->state;
1090         int err = -ENOMEM;
1091
1092         mutex_init(&st->__state_lock);
1093         mutex_init(&st->__state_send_lock);
1094         init_waitqueue_head(&st->thread_wait);
1095
1096         st->psb = psb;
1097         st->trans_root = RB_ROOT;
1098         mutex_init(&st->trans_lock);
1099
1100         st->size = psb->trans_data_size;
1101         st->data = kmalloc(st->size, GFP_KERNEL);
1102         if (!st->data)
1103                 goto err_out_exit;
1104
1105         if (psb->perform_crypto) {
1106                 err = pohmelfs_crypto_engine_init(&st->eng, psb);
1107                 if (err)
1108                         goto err_out_free_data;
1109         }
1110
1111         err = netfs_state_init(st);
1112         if (err)
1113                 goto err_out_free_engine;
1114
1115         st->thread = kthread_run(pohmelfs_recv, st, "pohmelfs/%u", psb->idx);
1116         if (IS_ERR(st->thread)) {
1117                 err = PTR_ERR(st->thread);
1118                 goto err_out_netfs_exit;
1119         }
1120
1121         if (!psb->active_state)
1122                 psb->active_state = conf;
1123
1124         dprintk("%s: conf: %p, st: %p, socket: %p.\n",
1125                         __func__, conf, st, st->socket);
1126         return 0;
1127
1128 err_out_netfs_exit:
1129         netfs_state_exit(st);
1130 err_out_free_engine:
1131         pohmelfs_crypto_engine_exit(&st->eng);
1132 err_out_free_data:
1133         kfree(st->data);
1134 err_out_exit:
1135         return err;
1136
1137 }
1138
1139 void pohmelfs_state_flush_transactions(struct netfs_state *st)
1140 {
1141         struct rb_node *rb_node;
1142         struct netfs_trans_dst *dst;
1143
1144         mutex_lock(&st->trans_lock);
1145         for (rb_node = rb_first(&st->trans_root); rb_node; ) {
1146                 dst = rb_entry(rb_node, struct netfs_trans_dst, state_entry);
1147                 rb_node = rb_next(rb_node);
1148
1149                 dst->trans->result = -EINVAL;
1150                 netfs_trans_remove_nolock(dst, st);
1151                 netfs_trans_drop_dst_nostate(dst);
1152         }
1153         mutex_unlock(&st->trans_lock);
1154 }
1155
1156 static void pohmelfs_state_exit_one(struct pohmelfs_config *c)
1157 {
1158         struct netfs_state *st = &c->state;
1159
1160         dprintk("%s: exiting, st: %p.\n", __func__, st);
1161         if (st->thread) {
1162                 kthread_stop(st->thread);
1163                 st->thread = NULL;
1164         }
1165
1166         netfs_state_lock_send(st);
1167         netfs_state_exit(st);
1168         netfs_state_unlock_send(st);
1169
1170         pohmelfs_state_flush_transactions(st);
1171
1172         pohmelfs_crypto_engine_exit(&st->eng);
1173         kfree(st->data);
1174
1175         kfree(c);
1176 }
1177
1178 /*
1179  * Initialize network stack. It searches for given ID in global
1180  * configuration table, this contains information of the remote server
1181  * (address (any supported by socket interface) and port, protocol and so on).
1182  */
1183 int pohmelfs_state_init(struct pohmelfs_sb *psb)
1184 {
1185         int err = -ENOMEM;
1186
1187         err = pohmelfs_copy_config(psb);
1188         if (err) {
1189                 pohmelfs_state_exit(psb);
1190                 return err;
1191         }
1192
1193         return 0;
1194 }
1195
1196 void pohmelfs_state_exit(struct pohmelfs_sb *psb)
1197 {
1198         struct pohmelfs_config *c, *tmp;
1199
1200         list_for_each_entry_safe(c, tmp, &psb->state_list, config_entry) {
1201                 list_del(&c->config_entry);
1202                 pohmelfs_state_exit_one(c);
1203         }
1204 }
1205
1206 void pohmelfs_switch_active(struct pohmelfs_sb *psb)
1207 {
1208         struct pohmelfs_config *c = psb->active_state;
1209
1210         if (!list_empty(&psb->state_list)) {
1211                 if (c->config_entry.next != &psb->state_list) {
1212                         psb->active_state = list_entry(c->config_entry.next,
1213                                 struct pohmelfs_config, config_entry);
1214                 } else {
1215                         psb->active_state = list_entry(psb->state_list.next,
1216                                 struct pohmelfs_config, config_entry);
1217                 }
1218
1219                 dprintk("%s: empty: %d, active %p -> %p.\n",
1220                         __func__, list_empty(&psb->state_list), c,
1221                         psb->active_state);
1222         } else
1223                 psb->active_state = NULL;
1224 }
1225
1226 void pohmelfs_check_states(struct pohmelfs_sb *psb)
1227 {
1228         struct pohmelfs_config *c, *tmp;
1229         LIST_HEAD(delete_list);
1230
1231         mutex_lock(&psb->state_lock);
1232         list_for_each_entry_safe(c, tmp, &psb->state_list, config_entry) {
1233                 if (pohmelfs_config_check(c, psb->idx)) {
1234
1235                         if (psb->active_state == c)
1236                                 pohmelfs_switch_active(psb);
1237                         list_move(&c->config_entry, &delete_list);
1238                 }
1239         }
1240         pohmelfs_copy_config(psb);
1241         mutex_unlock(&psb->state_lock);
1242
1243         list_for_each_entry_safe(c, tmp, &delete_list, config_entry) {
1244                 list_del(&c->config_entry);
1245                 pohmelfs_state_exit_one(c);
1246         }
1247 }