Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 | /*
* 2007+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/dst.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/socket.h>
#include <net/sock.h>
/*
* Export bioset is used for server block IO requests.
*/
static struct bio_set *dst_bio_set;
int __init dst_export_init(void)
{
int err = -ENOMEM;
dst_bio_set = bioset_create(32, sizeof(struct dst_export_priv));
if (!dst_bio_set)
goto err_out_exit;
return 0;
err_out_exit:
return err;
}
void dst_export_exit(void)
{
bioset_free(dst_bio_set);
}
/*
* When client connects and autonegotiates with the server node,
* its permissions are checked in a security attributes and sent
* back.
*/
static unsigned int dst_check_permissions(struct dst_state *main, struct dst_state *st)
{
struct dst_node *n = main->node;
struct dst_secure *sentry;
struct dst_secure_user *s;
struct saddr *sa = &st->ctl.addr;
unsigned int perm = 0;
mutex_lock(&n->security_lock);
list_for_each_entry(sentry, &n->security_list, sec_entry) {
s = &sentry->sec;
if (s->addr.sa_family != sa->sa_family)
continue;
if (s->addr.sa_data_len != sa->sa_data_len)
continue;
/*
* This '2' below is a port field. This may be very wrong to do
* in atalk for example though. If there will be any need to extent
* protocol to something else, I can create per-family helpers and
* use them instead of this memcmp.
*/
if (memcmp(s->addr.sa_data + 2, sa->sa_data + 2,
sa->sa_data_len - 2))
continue;
perm = s->permissions;
}
mutex_unlock(&n->security_lock);
return perm;
}
/*
* Accept new client: allocate appropriate network state and check permissions.
*/
static struct dst_state *dst_accept_client(struct dst_state *st)
{
unsigned int revents = 0;
unsigned int err_mask = POLLERR | POLLHUP | POLLRDHUP;
unsigned int mask = err_mask | POLLIN;
struct dst_node *n = st->node;
int err = 0;
struct socket *sock = NULL;
struct dst_state *new;
while (!err && !sock) {
revents = dst_state_poll(st);
if (!(revents & mask)) {
DEFINE_WAIT(wait);
for (;;) {
prepare_to_wait(&st->thread_wait,
&wait, TASK_INTERRUPTIBLE);
if (!n->trans_scan_timeout || st->need_exit)
break;
revents = dst_state_poll(st);
if (revents & mask)
break;
if (signal_pending(current))
break;
/*
* Magic HZ? Polling check above is not safe in
* all cases (like socket reset in BH context),
* so it is simpler just to postpone it to the
* process context instead of implementing special
* locking there.
*/
schedule_timeout(HZ);
}
finish_wait(&st->thread_wait, &wait);
}
err = -ECONNRESET;
dst_state_lock(st);
dprintk("%s: st: %p, revents: %x [err: %d, in: %d].\n",
__func__, st, revents, revents & err_mask,
revents & POLLIN);
if (revents & err_mask) {
dprintk("%s: revents: %x, socket: %p, err: %d.\n",
__func__, revents, st->socket, err);
err = -ECONNRESET;
}
if (!n->trans_scan_timeout || st->need_exit)
err = -ENODEV;
if (st->socket && (revents & POLLIN))
err = kernel_accept(st->socket, &sock, 0);
dst_state_unlock(st);
}
if (err)
goto err_out_exit;
new = dst_state_alloc(st->node);
if (!new) {
err = -ENOMEM;
goto err_out_release;
}
new->socket = sock;
new->ctl.addr.sa_data_len = sizeof(struct sockaddr);
err = kernel_getpeername(sock, (struct sockaddr *)&new->ctl.addr,
(int *)&new->ctl.addr.sa_data_len);
if (err)
goto err_out_put;
new->permissions = dst_check_permissions(st, new);
if (new->permissions == 0) {
err = -EPERM;
dst_dump_addr(sock, (struct sockaddr *)&new->ctl.addr,
"Client is not allowed to connect");
goto err_out_put;
}
err = dst_poll_init(new);
if (err)
goto err_out_put;
dst_dump_addr(sock, (struct sockaddr *)&new->ctl.addr,
"Connected client");
return new;
err_out_put:
dst_state_put(new);
err_out_release:
sock_release(sock);
err_out_exit:
return ERR_PTR(err);
}
/*
* Each server's block request sometime finishes.
* Usually it happens in hard irq context of the appropriate controller,
* so to play good with all cases we just queue BIO into the queue
* and wake up processing thread, which gets completed request and
* send (encrypting if needed) it back to the client (if it was a read
* request), or sends back reply that writing succesfully completed.
*/
static int dst_export_process_request_queue(struct dst_state *st)
{
unsigned long flags;
struct dst_export_priv *p = NULL;
struct bio *bio;
int err = 0;
while (!list_empty(&st->request_list)) {
spin_lock_irqsave(&st->request_lock, flags);
if (!list_empty(&st->request_list)) {
p = list_first_entry(&st->request_list,
struct dst_export_priv, request_entry);
list_del(&p->request_entry);
}
spin_unlock_irqrestore(&st->request_lock, flags);
if (!p)
break;
bio = p->bio;
if (dst_need_crypto(st->node) && (bio_data_dir(bio) == READ))
err = dst_export_crypto(st->node, bio);
else
err = dst_export_send_bio(bio);
if (err)
break;
}
return err;
}
/*
* Cleanup export state.
* It has to wait until all requests are finished,
* and then free them all.
*/
static void dst_state_cleanup_export(struct dst_state *st)
{
struct dst_export_priv *p;
unsigned long flags;
/*
* This loop waits for all pending bios to be completed and freed.
*/
while (atomic_read(&st->refcnt) > 1) {
dprintk("%s: st: %p, refcnt: %d, list_empty: %d.\n",
__func__, st, atomic_read(&st->refcnt),
list_empty(&st->request_list));
wait_event_timeout(st->thread_wait,
(atomic_read(&st->refcnt) == 1) ||
!list_empty(&st->request_list),
HZ/2);
while (!list_empty(&st->request_list)) {
p = NULL;
spin_lock_irqsave(&st->request_lock, flags);
if (!list_empty(&st->request_list)) {
p = list_first_entry(&st->request_list,
struct dst_export_priv, request_entry);
list_del(&p->request_entry);
}
spin_unlock_irqrestore(&st->request_lock, flags);
if (p)
bio_put(p->bio);
dprintk("%s: st: %p, refcnt: %d, list_empty: %d, p: %p.\n",
__func__, st, atomic_read(&st->refcnt),
list_empty(&st->request_list), p);
}
}
dst_state_put(st);
}
/*
* Client accepting thread.
* Not only accepts new connection, but also schedules receiving thread
* and performs request completion described above.
*/
static int dst_accept(void *init_data, void *schedule_data)
{
struct dst_state *main_st = schedule_data;
struct dst_node *n = init_data;
struct dst_state *st;
int err;
while (n->trans_scan_timeout && !main_st->need_exit) {
dprintk("%s: main_st: %p, n: %p.\n", __func__, main_st, n);
st = dst_accept_client(main_st);
if (IS_ERR(st))
continue;
err = dst_state_schedule_receiver(st);
if (!err) {
while (n->trans_scan_timeout) {
err = wait_event_interruptible_timeout(st->thread_wait,
!list_empty(&st->request_list) ||
!n->trans_scan_timeout ||
st->need_exit,
HZ);
if (!n->trans_scan_timeout || st->need_exit)
break;
if (list_empty(&st->request_list))
continue;
err = dst_export_process_request_queue(st);
if (err)
break;
}
st->need_exit = 1;
wake_up(&st->thread_wait);
}
dst_state_cleanup_export(st);
}
dprintk("%s: freeing listening socket st: %p.\n", __func__, main_st);
dst_state_lock(main_st);
dst_poll_exit(main_st);
dst_state_socket_release(main_st);
dst_state_unlock(main_st);
dst_state_put(main_st);
dprintk("%s: freed listening socket st: %p.\n", __func__, main_st);
return 0;
}
int dst_start_export(struct dst_node *n)
{
if (list_empty(&n->security_list)) {
printk(KERN_ERR "You are trying to export node '%s' without security attributes.\n"
"No clients will be allowed to connect. Exiting.\n", n->name);
return -EINVAL;
}
return dst_node_trans_init(n, sizeof(struct dst_export_priv));
}
/*
* Initialize listening state and schedule accepting thread.
*/
int dst_node_init_listened(struct dst_node *n, struct dst_export_ctl *le)
{
struct dst_state *st;
int err = -ENOMEM;
struct dst_network_ctl *ctl = &le->ctl;
memcpy(&n->info->net, ctl, sizeof(struct dst_network_ctl));
st = dst_state_alloc(n);
if (IS_ERR(st)) {
err = PTR_ERR(st);
goto err_out_exit;
}
memcpy(&st->ctl, ctl, sizeof(struct dst_network_ctl));
err = dst_state_socket_create(st);
if (err)
goto err_out_put;
st->socket->sk->sk_reuse = 1;
err = kernel_bind(st->socket, (struct sockaddr *)&ctl->addr,
ctl->addr.sa_data_len);
if (err)
goto err_out_socket_release;
err = kernel_listen(st->socket, 1024);
if (err)
goto err_out_socket_release;
n->state = st;
err = dst_poll_init(st);
if (err)
goto err_out_socket_release;
dst_state_get(st);
err = thread_pool_schedule(n->pool, dst_thread_setup,
dst_accept, st, MAX_SCHEDULE_TIMEOUT);
if (err)
goto err_out_poll_exit;
return 0;
err_out_poll_exit:
dst_poll_exit(st);
err_out_socket_release:
dst_state_socket_release(st);
err_out_put:
dst_state_put(st);
err_out_exit:
n->state = NULL;
return err;
}
/*
* Free bio and related private data.
* Also drop a reference counter for appropriate state,
* which waits when there are no more block IOs in-flight.
*/
static void dst_bio_destructor(struct bio *bio)
{
struct bio_vec *bv;
struct dst_export_priv *priv = bio->bi_private;
int i;
bio_for_each_segment(bv, bio, i) {
if (!bv->bv_page)
break;
__free_page(bv->bv_page);
}
if (priv)
dst_state_put(priv->state);
bio_free(bio, dst_bio_set);
}
/*
* Block IO completion. Queue request to be sent back to
* the client (or just confirmation).
*/
static void dst_bio_end_io(struct bio *bio, int err)
{
struct dst_export_priv *p = bio->bi_private;
struct dst_state *st = p->state;
unsigned long flags;
spin_lock_irqsave(&st->request_lock, flags);
list_add_tail(&p->request_entry, &st->request_list);
spin_unlock_irqrestore(&st->request_lock, flags);
wake_up(&st->thread_wait);
}
/*
* Allocate read request for the server.
*/
static int dst_export_read_request(struct bio *bio, unsigned int total_size)
{
unsigned int size;
struct page *page;
int err;
while (total_size) {
err = -ENOMEM;
page = alloc_page(GFP_KERNEL);
if (!page)
goto err_out_exit;
size = min_t(unsigned int, PAGE_SIZE, total_size);
err = bio_add_page(bio, page, size, 0);
dprintk("%s: bio: %llu/%u, size: %u, err: %d.\n",
__func__, (u64)bio->bi_sector, bio->bi_size,
size, err);
if (err <= 0)
goto err_out_free_page;
total_size -= size;
}
return 0;
err_out_free_page:
__free_page(page);
err_out_exit:
return err;
}
/*
* Allocate write request for the server.
* Should not only get pages, but also read data from the network.
*/
static int dst_export_write_request(struct dst_state *st,
struct bio *bio, unsigned int total_size)
{
unsigned int size;
struct page *page;
void *data;
int err;
while (total_size) {
err = -ENOMEM;
page = alloc_page(GFP_KERNEL);
if (!page)
goto err_out_exit;
data = kmap(page);
if (!data)
goto err_out_free_page;
size = min_t(unsigned int, PAGE_SIZE, total_size);
err = dst_data_recv(st, data, size);
if (err)
goto err_out_unmap_page;
err = bio_add_page(bio, page, size, 0);
if (err <= 0)
goto err_out_unmap_page;
kunmap(page);
total_size -= size;
}
return 0;
err_out_unmap_page:
kunmap(page);
err_out_free_page:
__free_page(page);
err_out_exit:
return err;
}
/*
* Groovy, we've gotten an IO request from the client.
* Allocate BIO from the bioset, private data from the mempool
* and lots of pages for IO.
*/
int dst_process_io(struct dst_state *st)
{
struct dst_node *n = st->node;
struct dst_cmd *cmd = st->data;
struct bio *bio;
struct dst_export_priv *priv;
int err = -ENOMEM;
if (unlikely(!n->bdev)) {
err = -EINVAL;
goto err_out_exit;
}
bio = bio_alloc_bioset(GFP_KERNEL,
PAGE_ALIGN(cmd->size) >> PAGE_SHIFT,
dst_bio_set);
if (!bio)
goto err_out_exit;
priv = (struct dst_export_priv *)(((void *)bio) - sizeof (struct dst_export_priv));
priv->state = dst_state_get(st);
priv->bio = bio;
bio->bi_private = priv;
bio->bi_end_io = dst_bio_end_io;
bio->bi_destructor = dst_bio_destructor;
bio->bi_bdev = n->bdev;
/*
* Server side is only interested in two low bits:
* uptodate (set by itself actually) and rw block
*/
bio->bi_flags |= cmd->flags & 3;
bio->bi_rw = cmd->rw;
bio->bi_size = 0;
bio->bi_sector = cmd->sector;
dst_bio_to_cmd(bio, &priv->cmd, DST_IO_RESPONSE, cmd->id);
priv->cmd.flags = 0;
priv->cmd.size = cmd->size;
if (bio_data_dir(bio) == WRITE) {
err = dst_recv_cdata(st, priv->cmd.hash);
if (err)
goto err_out_free;
err = dst_export_write_request(st, bio, cmd->size);
if (err)
goto err_out_free;
if (dst_need_crypto(n))
return dst_export_crypto(n, bio);
} else {
err = dst_export_read_request(bio, cmd->size);
if (err)
goto err_out_free;
}
dprintk("%s: bio: %llu/%u, rw: %lu, dir: %lu, flags: %lx, phys: %d.\n",
__func__, (u64)bio->bi_sector, bio->bi_size,
bio->bi_rw, bio_data_dir(bio),
bio->bi_flags, bio->bi_phys_segments);
generic_make_request(bio);
return 0;
err_out_free:
bio_put(bio);
err_out_exit:
return err;
}
/*
* Ok, block IO is ready, let's send it back to the client...
*/
int dst_export_send_bio(struct bio *bio)
{
struct dst_export_priv *p = bio->bi_private;
struct dst_state *st = p->state;
struct dst_cmd *cmd = &p->cmd;
int err;
dprintk("%s: id: %llu, bio: %llu/%u, csize: %u, flags: %lu, rw: %lu.\n",
__func__, cmd->id, (u64)bio->bi_sector, bio->bi_size,
cmd->csize, bio->bi_flags, bio->bi_rw);
dst_convert_cmd(cmd);
dst_state_lock(st);
if (!st->socket) {
err = -ECONNRESET;
goto err_out_unlock;
}
if (bio_data_dir(bio) == WRITE) {
/* ... or just confirmation that writing has completed. */
cmd->size = cmd->csize = 0;
err = dst_data_send_header(st->socket, cmd,
sizeof(struct dst_cmd), 0);
if (err)
goto err_out_unlock;
} else {
err = dst_send_bio(st, cmd, bio);
if (err)
goto err_out_unlock;
}
dst_state_unlock(st);
bio_put(bio);
return 0;
err_out_unlock:
dst_state_unlock(st);
bio_put(bio);
return err;
}
|