drbd_receiver.c 134.0 KB
Newer Older
P
Philipp Reisner 已提交
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
/*
   drbd_receiver.c

   This file is part of DRBD by Philipp Reisner and Lars Ellenberg.

   Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
   Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
   Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.

   drbd 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, or (at your option)
   any later version.

   drbd 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.

   You should have received a copy of the GNU General Public License
   along with drbd; see the file COPYING.  If not, write to
   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 */


#include <linux/module.h>

#include <asm/uaccess.h>
#include <net/sock.h>

#include <linux/drbd.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/in.h>
#include <linux/mm.h>
#include <linux/memcontrol.h>
#include <linux/mm_inline.h>
#include <linux/slab.h>
#include <linux/pkt_sched.h>
#define __KERNEL_SYSCALLS__
#include <linux/unistd.h>
#include <linux/vmalloc.h>
#include <linux/random.h>
#include <linux/string.h>
#include <linux/scatterlist.h>
#include "drbd_int.h"
#include "drbd_req.h"

#include "drbd_vli.h"

51 52 53 54 55 56
struct packet_info {
	enum drbd_packet cmd;
	int size;
	int vnr;
};

P
Philipp Reisner 已提交
57 58 59 60 61 62
enum finish_epoch {
	FE_STILL_LIVE,
	FE_DESTROYED,
	FE_RECYCLED,
};

63 64 65 66 67
enum mdev_or_conn {
	MDEV,
	CONN,
};

68
static int drbd_do_handshake(struct drbd_tconn *tconn);
69
static int drbd_do_auth(struct drbd_tconn *tconn);
70
static int drbd_disconnected(int vnr, void *p, void *data);
P
Philipp Reisner 已提交
71 72

static enum finish_epoch drbd_may_finish_epoch(struct drbd_conf *, struct drbd_epoch *, enum epoch_event);
73
static int e_end_block(struct drbd_work *, int);
P
Philipp Reisner 已提交
74 75 76 77


#define GFP_TRY	(__GFP_HIGHMEM | __GFP_NOWARN)

78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95
/*
 * some helper functions to deal with single linked page lists,
 * page->private being our "next" pointer.
 */

/* If at least n pages are linked at head, get n pages off.
 * Otherwise, don't modify head, and return NULL.
 * Locking is the responsibility of the caller.
 */
static struct page *page_chain_del(struct page **head, int n)
{
	struct page *page;
	struct page *tmp;

	BUG_ON(!n);
	BUG_ON(!head);

	page = *head;
96 97 98 99

	if (!page)
		return NULL;

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
	while (page) {
		tmp = page_chain_next(page);
		if (--n == 0)
			break; /* found sufficient pages */
		if (tmp == NULL)
			/* insufficient pages, don't use any of them. */
			return NULL;
		page = tmp;
	}

	/* add end of list marker for the returned list */
	set_page_private(page, 0);
	/* actual return value, and adjustment of head */
	page = *head;
	*head = tmp;
	return page;
}

/* may be used outside of locks to find the tail of a (usually short)
 * "private" page chain, before adding it back to a global chain head
 * with page_chain_add() under a spinlock. */
static struct page *page_chain_tail(struct page *page, int *len)
{
	struct page *tmp;
	int i = 1;
	while ((tmp = page_chain_next(page)))
		++i, page = tmp;
	if (len)
		*len = i;
	return page;
}

static int page_chain_free(struct page *page)
{
	struct page *tmp;
	int i = 0;
	page_chain_for_each_safe(page, tmp) {
		put_page(page);
		++i;
	}
	return i;
}

static void page_chain_add(struct page **head,
		struct page *chain_first, struct page *chain_last)
{
#if 1
	struct page *tmp;
	tmp = page_chain_tail(chain_first, NULL);
	BUG_ON(tmp != chain_last);
#endif

	/* add chain to head */
	set_page_private(chain_last, (unsigned long)*head);
	*head = chain_first;
}

static struct page *drbd_pp_first_pages_or_try_alloc(struct drbd_conf *mdev, int number)
P
Philipp Reisner 已提交
158 159
{
	struct page *page = NULL;
160 161
	struct page *tmp = NULL;
	int i = 0;
P
Philipp Reisner 已提交
162 163 164

	/* Yes, testing drbd_pp_vacant outside the lock is racy.
	 * So what. It saves a spin_lock. */
165
	if (drbd_pp_vacant >= number) {
P
Philipp Reisner 已提交
166
		spin_lock(&drbd_pp_lock);
167 168 169
		page = page_chain_del(&drbd_pp_pool, number);
		if (page)
			drbd_pp_vacant -= number;
P
Philipp Reisner 已提交
170
		spin_unlock(&drbd_pp_lock);
171 172
		if (page)
			return page;
P
Philipp Reisner 已提交
173
	}
174

P
Philipp Reisner 已提交
175 176 177
	/* GFP_TRY, because we must not cause arbitrary write-out: in a DRBD
	 * "criss-cross" setup, that might cause write-out on some other DRBD,
	 * which in turn might block on the other node at this very place.  */
178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199
	for (i = 0; i < number; i++) {
		tmp = alloc_page(GFP_TRY);
		if (!tmp)
			break;
		set_page_private(tmp, (unsigned long)page);
		page = tmp;
	}

	if (i == number)
		return page;

	/* Not enough pages immediately available this time.
	 * No need to jump around here, drbd_pp_alloc will retry this
	 * function "soon". */
	if (page) {
		tmp = page_chain_tail(page, NULL);
		spin_lock(&drbd_pp_lock);
		page_chain_add(&drbd_pp_pool, page, tmp);
		drbd_pp_vacant += i;
		spin_unlock(&drbd_pp_lock);
	}
	return NULL;
P
Philipp Reisner 已提交
200 201 202 203
}

static void reclaim_net_ee(struct drbd_conf *mdev, struct list_head *to_be_freed)
{
204
	struct drbd_peer_request *peer_req;
P
Philipp Reisner 已提交
205 206 207 208 209 210 211 212
	struct list_head *le, *tle;

	/* The EEs are always appended to the end of the list. Since
	   they are sent in order over the wire, they have to finish
	   in order. As soon as we see the first not finished we can
	   stop to examine the list... */

	list_for_each_safe(le, tle, &mdev->net_ee) {
213 214
		peer_req = list_entry(le, struct drbd_peer_request, w.list);
		if (drbd_ee_has_active_page(peer_req))
P
Philipp Reisner 已提交
215 216 217 218 219 220 221 222
			break;
		list_move(le, to_be_freed);
	}
}

static void drbd_kick_lo_and_reclaim_net(struct drbd_conf *mdev)
{
	LIST_HEAD(reclaimed);
223
	struct drbd_peer_request *peer_req, *t;
P
Philipp Reisner 已提交
224

225
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
226
	reclaim_net_ee(mdev, &reclaimed);
227
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
228

229 230
	list_for_each_entry_safe(peer_req, t, &reclaimed, w.list)
		drbd_free_net_ee(mdev, peer_req);
P
Philipp Reisner 已提交
231 232 233
}

/**
234
 * drbd_pp_alloc() - Returns @number pages, retries forever (or until signalled)
P
Philipp Reisner 已提交
235
 * @mdev:	DRBD device.
236 237 238 239 240 241
 * @number:	number of pages requested
 * @retry:	whether to retry, if not enough pages are available right now
 *
 * Tries to allocate number pages, first from our own page pool, then from
 * the kernel, unless this allocation would exceed the max_buffers setting.
 * Possibly retry until DRBD frees sufficient pages somewhere else.
P
Philipp Reisner 已提交
242
 *
243
 * Returns a page chain linked via page->private.
P
Philipp Reisner 已提交
244
 */
245
static struct page *drbd_pp_alloc(struct drbd_conf *mdev, unsigned number, bool retry)
P
Philipp Reisner 已提交
246 247 248 249
{
	struct page *page = NULL;
	DEFINE_WAIT(wait);

250 251
	/* Yes, we may run up to @number over max_buffers. If we
	 * follow it strictly, the admin will get it wrong anyways. */
252
	if (atomic_read(&mdev->pp_in_use) < mdev->tconn->net_conf->max_buffers)
253
		page = drbd_pp_first_pages_or_try_alloc(mdev, number);
P
Philipp Reisner 已提交
254

255
	while (page == NULL) {
P
Philipp Reisner 已提交
256 257 258 259
		prepare_to_wait(&drbd_pp_wait, &wait, TASK_INTERRUPTIBLE);

		drbd_kick_lo_and_reclaim_net(mdev);

260
		if (atomic_read(&mdev->pp_in_use) < mdev->tconn->net_conf->max_buffers) {
261
			page = drbd_pp_first_pages_or_try_alloc(mdev, number);
P
Philipp Reisner 已提交
262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277
			if (page)
				break;
		}

		if (!retry)
			break;

		if (signal_pending(current)) {
			dev_warn(DEV, "drbd_pp_alloc interrupted!\n");
			break;
		}

		schedule();
	}
	finish_wait(&drbd_pp_wait, &wait);

278 279
	if (page)
		atomic_add(number, &mdev->pp_in_use);
P
Philipp Reisner 已提交
280 281 282 283
	return page;
}

/* Must not be used from irq, as that may deadlock: see drbd_pp_alloc.
284
 * Is also used from inside an other spin_lock_irq(&mdev->tconn->req_lock);
285 286
 * Either links the page chain back to the global pool,
 * or returns all pages to the system. */
287
static void drbd_pp_free(struct drbd_conf *mdev, struct page *page, int is_net)
P
Philipp Reisner 已提交
288
{
289
	atomic_t *a = is_net ? &mdev->pp_in_use_by_net : &mdev->pp_in_use;
P
Philipp Reisner 已提交
290
	int i;
291

292
	if (drbd_pp_vacant > (DRBD_MAX_BIO_SIZE/PAGE_SIZE) * minor_count)
293 294 295 296 297 298 299 300
		i = page_chain_free(page);
	else {
		struct page *tmp;
		tmp = page_chain_tail(page, &i);
		spin_lock(&drbd_pp_lock);
		page_chain_add(&drbd_pp_pool, page, tmp);
		drbd_pp_vacant += i;
		spin_unlock(&drbd_pp_lock);
P
Philipp Reisner 已提交
301
	}
302
	i = atomic_sub_return(i, a);
303
	if (i < 0)
304 305
		dev_warn(DEV, "ASSERTION FAILED: %s: %d < 0\n",
			is_net ? "pp_in_use_by_net" : "pp_in_use", i);
P
Philipp Reisner 已提交
306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323
	wake_up(&drbd_pp_wait);
}

/*
You need to hold the req_lock:
 _drbd_wait_ee_list_empty()

You must not have the req_lock:
 drbd_free_ee()
 drbd_alloc_ee()
 drbd_init_ee()
 drbd_release_ee()
 drbd_ee_fix_bhs()
 drbd_process_done_ee()
 drbd_clear_done_ee()
 drbd_wait_ee_list_empty()
*/

324 325 326
struct drbd_peer_request *
drbd_alloc_ee(struct drbd_conf *mdev, u64 id, sector_t sector,
	      unsigned int data_size, gfp_t gfp_mask) __must_hold(local)
P
Philipp Reisner 已提交
327
{
328
	struct drbd_peer_request *peer_req;
P
Philipp Reisner 已提交
329
	struct page *page;
330
	unsigned nr_pages = (data_size + PAGE_SIZE -1) >> PAGE_SHIFT;
P
Philipp Reisner 已提交
331

332
	if (drbd_insert_fault(mdev, DRBD_FAULT_AL_EE))
P
Philipp Reisner 已提交
333 334
		return NULL;

335 336
	peer_req = mempool_alloc(drbd_ee_mempool, gfp_mask & ~__GFP_HIGHMEM);
	if (!peer_req) {
P
Philipp Reisner 已提交
337 338 339 340 341
		if (!(gfp_mask & __GFP_NOWARN))
			dev_err(DEV, "alloc_ee: Allocation of an EE failed\n");
		return NULL;
	}

342 343 344
	page = drbd_pp_alloc(mdev, nr_pages, (gfp_mask & __GFP_WAIT));
	if (!page)
		goto fail;
P
Philipp Reisner 已提交
345

346 347 348 349 350 351 352
	drbd_clear_interval(&peer_req->i);
	peer_req->i.size = data_size;
	peer_req->i.sector = sector;
	peer_req->i.local = false;
	peer_req->i.waiting = false;

	peer_req->epoch = NULL;
353
	peer_req->w.mdev = mdev;
354 355 356
	peer_req->pages = page;
	atomic_set(&peer_req->pending_bios, 0);
	peer_req->flags = 0;
357 358 359 360
	/*
	 * The block_id is opaque to the receiver.  It is not endianness
	 * converted, and sent back to the sender unchanged.
	 */
361
	peer_req->block_id = id;
P
Philipp Reisner 已提交
362

363
	return peer_req;
P
Philipp Reisner 已提交
364

365
 fail:
366
	mempool_free(peer_req, drbd_ee_mempool);
P
Philipp Reisner 已提交
367 368 369
	return NULL;
}

370
void drbd_free_some_ee(struct drbd_conf *mdev, struct drbd_peer_request *peer_req,
371
		       int is_net)
P
Philipp Reisner 已提交
372
{
373 374 375 376 377 378
	if (peer_req->flags & EE_HAS_DIGEST)
		kfree(peer_req->digest);
	drbd_pp_free(mdev, peer_req->pages, is_net);
	D_ASSERT(atomic_read(&peer_req->pending_bios) == 0);
	D_ASSERT(drbd_interval_empty(&peer_req->i));
	mempool_free(peer_req, drbd_ee_mempool);
P
Philipp Reisner 已提交
379 380 381 382 383
}

int drbd_release_ee(struct drbd_conf *mdev, struct list_head *list)
{
	LIST_HEAD(work_list);
384
	struct drbd_peer_request *peer_req, *t;
P
Philipp Reisner 已提交
385
	int count = 0;
386
	int is_net = list == &mdev->net_ee;
P
Philipp Reisner 已提交
387

388
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
389
	list_splice_init(list, &work_list);
390
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
391

392 393
	list_for_each_entry_safe(peer_req, t, &work_list, w.list) {
		drbd_free_some_ee(mdev, peer_req, is_net);
P
Philipp Reisner 已提交
394 395 396 397 398 399
		count++;
	}
	return count;
}


400
/* See also comments in _req_mod(,BARRIER_ACKED)
P
Philipp Reisner 已提交
401 402 403 404 405 406 407 408 409 410
 * and receive_Barrier.
 *
 * Move entries from net_ee to done_ee, if ready.
 * Grab done_ee, call all callbacks, free the entries.
 * The callbacks typically send out ACKs.
 */
static int drbd_process_done_ee(struct drbd_conf *mdev)
{
	LIST_HEAD(work_list);
	LIST_HEAD(reclaimed);
411
	struct drbd_peer_request *peer_req, *t;
412
	int err = 0;
P
Philipp Reisner 已提交
413

414
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
415 416
	reclaim_net_ee(mdev, &reclaimed);
	list_splice_init(&mdev->done_ee, &work_list);
417
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
418

419 420
	list_for_each_entry_safe(peer_req, t, &reclaimed, w.list)
		drbd_free_net_ee(mdev, peer_req);
P
Philipp Reisner 已提交
421 422

	/* possible callbacks here:
423
	 * e_end_block, and e_end_resync_block, e_send_discard_write.
P
Philipp Reisner 已提交
424 425
	 * all ignore the last argument.
	 */
426
	list_for_each_entry_safe(peer_req, t, &work_list, w.list) {
427 428
		int err2;

P
Philipp Reisner 已提交
429
		/* list_del not necessary, next/prev members not touched */
430 431 432
		err2 = peer_req->w.cb(&peer_req->w, !!err);
		if (!err)
			err = err2;
433
		drbd_free_ee(mdev, peer_req);
P
Philipp Reisner 已提交
434 435 436
	}
	wake_up(&mdev->ee_wait);

437
	return err;
P
Philipp Reisner 已提交
438 439 440 441 442 443 444 445 446 447
}

void _drbd_wait_ee_list_empty(struct drbd_conf *mdev, struct list_head *head)
{
	DEFINE_WAIT(wait);

	/* avoids spin_lock/unlock
	 * and calling prepare_to_wait in the fast path */
	while (!list_empty(head)) {
		prepare_to_wait(&mdev->ee_wait, &wait, TASK_UNINTERRUPTIBLE);
448
		spin_unlock_irq(&mdev->tconn->req_lock);
J
Jens Axboe 已提交
449
		io_schedule();
P
Philipp Reisner 已提交
450
		finish_wait(&mdev->ee_wait, &wait);
451
		spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
452 453 454 455 456
	}
}

void drbd_wait_ee_list_empty(struct drbd_conf *mdev, struct list_head *head)
{
457
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
458
	_drbd_wait_ee_list_empty(mdev, head);
459
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
460 461 462 463
}

/* see also kernel_accept; which is only present since 2.6.18.
 * also we want to log which part of it failed, exactly */
464
static int drbd_accept(const char **what, struct socket *sock, struct socket **newsock)
P
Philipp Reisner 已提交
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
{
	struct sock *sk = sock->sk;
	int err = 0;

	*what = "listen";
	err = sock->ops->listen(sock, 5);
	if (err < 0)
		goto out;

	*what = "sock_create_lite";
	err = sock_create_lite(sk->sk_family, sk->sk_type, sk->sk_protocol,
			       newsock);
	if (err < 0)
		goto out;

	*what = "accept";
	err = sock->ops->accept(sock, *newsock, 0);
	if (err < 0) {
		sock_release(*newsock);
		*newsock = NULL;
		goto out;
	}
	(*newsock)->ops  = sock->ops;

out:
	return err;
}

493
static int drbd_recv_short(struct socket *sock, void *buf, size_t size, int flags)
P
Philipp Reisner 已提交
494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514
{
	mm_segment_t oldfs;
	struct kvec iov = {
		.iov_base = buf,
		.iov_len = size,
	};
	struct msghdr msg = {
		.msg_iovlen = 1,
		.msg_iov = (struct iovec *)&iov,
		.msg_flags = (flags ? flags : MSG_WAITALL | MSG_NOSIGNAL)
	};
	int rv;

	oldfs = get_fs();
	set_fs(KERNEL_DS);
	rv = sock_recvmsg(sock, &msg, size, msg.msg_flags);
	set_fs(oldfs);

	return rv;
}

515
static int drbd_recv(struct drbd_tconn *tconn, void *buf, size_t size)
P
Philipp Reisner 已提交
516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532
{
	mm_segment_t oldfs;
	struct kvec iov = {
		.iov_base = buf,
		.iov_len = size,
	};
	struct msghdr msg = {
		.msg_iovlen = 1,
		.msg_iov = (struct iovec *)&iov,
		.msg_flags = MSG_WAITALL | MSG_NOSIGNAL
	};
	int rv;

	oldfs = get_fs();
	set_fs(KERNEL_DS);

	for (;;) {
533
		rv = sock_recvmsg(tconn->data.socket, &msg, size, msg.msg_flags);
P
Philipp Reisner 已提交
534 535 536 537 538 539 540 541 542 543
		if (rv == size)
			break;

		/* Note:
		 * ECONNRESET	other side closed the connection
		 * ERESTARTSYS	(on  sock) we got a signal
		 */

		if (rv < 0) {
			if (rv == -ECONNRESET)
544
				conn_info(tconn, "sock was reset by peer\n");
P
Philipp Reisner 已提交
545
			else if (rv != -ERESTARTSYS)
546
				conn_err(tconn, "sock_recvmsg returned %d\n", rv);
P
Philipp Reisner 已提交
547 548
			break;
		} else if (rv == 0) {
549
			conn_info(tconn, "sock was shut down by peer\n");
P
Philipp Reisner 已提交
550 551 552 553 554 555 556 557 558 559 560 561 562
			break;
		} else	{
			/* signal came in, or peer/link went down,
			 * after we read a partial message
			 */
			/* D_ASSERT(signal_pending(current)); */
			break;
		}
	};

	set_fs(oldfs);

	if (rv != size)
563
		conn_request_state(tconn, NS(conn, C_BROKEN_PIPE), CS_HARD);
P
Philipp Reisner 已提交
564 565 566 567

	return rv;
}

568 569 570 571 572 573 574 575 576 577 578 579 580
static int drbd_recv_all(struct drbd_tconn *tconn, void *buf, size_t size)
{
	int err;

	err = drbd_recv(tconn, buf, size);
	if (err != size) {
		if (err >= 0)
			err = -EIO;
	} else
		err = 0;
	return err;
}

581 582 583 584 585 586 587 588 589 590
static int drbd_recv_all_warn(struct drbd_tconn *tconn, void *buf, size_t size)
{
	int err;

	err = drbd_recv_all(tconn, buf, size);
	if (err && !signal_pending(current))
		conn_warn(tconn, "short read (expected size %d)\n", (int)size);
	return err;
}

591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609
/* quoting tcp(7):
 *   On individual connections, the socket buffer size must be set prior to the
 *   listen(2) or connect(2) calls in order to have it take effect.
 * This is our wrapper to do so.
 */
static void drbd_setbufsize(struct socket *sock, unsigned int snd,
		unsigned int rcv)
{
	/* open coded SO_SNDBUF, SO_RCVBUF */
	if (snd) {
		sock->sk->sk_sndbuf = snd;
		sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
	}
	if (rcv) {
		sock->sk->sk_rcvbuf = rcv;
		sock->sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
	}
}

610
static struct socket *drbd_try_connect(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
611 612 613 614 615 616 617
{
	const char *what;
	struct socket *sock;
	struct sockaddr_in6 src_in6;
	int err;
	int disconnect_on_error = 1;

618
	if (!get_net_conf(tconn))
P
Philipp Reisner 已提交
619 620 621
		return NULL;

	what = "sock_create_kern";
622
	err = sock_create_kern(((struct sockaddr *)tconn->net_conf->my_addr)->sa_family,
P
Philipp Reisner 已提交
623 624 625 626 627 628 629
		SOCK_STREAM, IPPROTO_TCP, &sock);
	if (err < 0) {
		sock = NULL;
		goto out;
	}

	sock->sk->sk_rcvtimeo =
630 631 632
	sock->sk->sk_sndtimeo =  tconn->net_conf->try_connect_int*HZ;
	drbd_setbufsize(sock, tconn->net_conf->sndbuf_size,
			tconn->net_conf->rcvbuf_size);
P
Philipp Reisner 已提交
633 634 635 636 637 638 639 640

       /* explicitly bind to the configured IP as source IP
	*  for the outgoing connections.
	*  This is needed for multihomed hosts and to be
	*  able to use lo: interfaces for drbd.
	* Make sure to use 0 as port number, so linux selects
	*  a free one dynamically.
	*/
641 642 643
	memcpy(&src_in6, tconn->net_conf->my_addr,
	       min_t(int, tconn->net_conf->my_addr_len, sizeof(src_in6)));
	if (((struct sockaddr *)tconn->net_conf->my_addr)->sa_family == AF_INET6)
P
Philipp Reisner 已提交
644 645 646 647 648 649 650
		src_in6.sin6_port = 0;
	else
		((struct sockaddr_in *)&src_in6)->sin_port = 0; /* AF_INET & AF_SCI */

	what = "bind before connect";
	err = sock->ops->bind(sock,
			      (struct sockaddr *) &src_in6,
651
			      tconn->net_conf->my_addr_len);
P
Philipp Reisner 已提交
652 653 654 655 656 657 658 659
	if (err < 0)
		goto out;

	/* connect may fail, peer not yet available.
	 * stay C_WF_CONNECTION, don't go Disconnecting! */
	disconnect_on_error = 0;
	what = "connect";
	err = sock->ops->connect(sock,
660 661
				 (struct sockaddr *)tconn->net_conf->peer_addr,
				 tconn->net_conf->peer_addr_len, 0);
P
Philipp Reisner 已提交
662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678

out:
	if (err < 0) {
		if (sock) {
			sock_release(sock);
			sock = NULL;
		}
		switch (-err) {
			/* timeout, busy, signal pending */
		case ETIMEDOUT: case EAGAIN: case EINPROGRESS:
		case EINTR: case ERESTARTSYS:
			/* peer not (yet) available, network problem */
		case ECONNREFUSED: case ENETUNREACH:
		case EHOSTDOWN:    case EHOSTUNREACH:
			disconnect_on_error = 0;
			break;
		default:
679
			conn_err(tconn, "%s failed, err = %d\n", what, err);
P
Philipp Reisner 已提交
680 681
		}
		if (disconnect_on_error)
682
			conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
P
Philipp Reisner 已提交
683
	}
684
	put_net_conf(tconn);
P
Philipp Reisner 已提交
685 686 687
	return sock;
}

688
static struct socket *drbd_wait_for_connect(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
689 690 691 692 693
{
	int timeo, err;
	struct socket *s_estab = NULL, *s_listen;
	const char *what;

694
	if (!get_net_conf(tconn))
P
Philipp Reisner 已提交
695 696 697
		return NULL;

	what = "sock_create_kern";
698
	err = sock_create_kern(((struct sockaddr *)tconn->net_conf->my_addr)->sa_family,
P
Philipp Reisner 已提交
699 700 701 702 703 704
		SOCK_STREAM, IPPROTO_TCP, &s_listen);
	if (err) {
		s_listen = NULL;
		goto out;
	}

705
	timeo = tconn->net_conf->try_connect_int * HZ;
P
Philipp Reisner 已提交
706 707 708 709 710
	timeo += (random32() & 1) ? timeo / 7 : -timeo / 7; /* 28.5% random jitter */

	s_listen->sk->sk_reuse    = 1; /* SO_REUSEADDR */
	s_listen->sk->sk_rcvtimeo = timeo;
	s_listen->sk->sk_sndtimeo = timeo;
711 712
	drbd_setbufsize(s_listen, tconn->net_conf->sndbuf_size,
			tconn->net_conf->rcvbuf_size);
P
Philipp Reisner 已提交
713 714 715

	what = "bind before listen";
	err = s_listen->ops->bind(s_listen,
716 717
			      (struct sockaddr *) tconn->net_conf->my_addr,
			      tconn->net_conf->my_addr_len);
P
Philipp Reisner 已提交
718 719 720
	if (err < 0)
		goto out;

721
	err = drbd_accept(&what, s_listen, &s_estab);
P
Philipp Reisner 已提交
722 723 724 725 726 727

out:
	if (s_listen)
		sock_release(s_listen);
	if (err < 0) {
		if (err != -EAGAIN && err != -EINTR && err != -ERESTARTSYS) {
728
			conn_err(tconn, "%s failed, err = %d\n", what, err);
729
			conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
P
Philipp Reisner 已提交
730 731
		}
	}
732
	put_net_conf(tconn);
P
Philipp Reisner 已提交
733 734 735 736

	return s_estab;
}

737
static int drbd_send_fp(struct drbd_tconn *tconn, struct socket *sock, enum drbd_packet cmd)
P
Philipp Reisner 已提交
738
{
739
	struct p_header *h = &tconn->data.sbuf.header;
P
Philipp Reisner 已提交
740

741
	return !_conn_send_cmd(tconn, 0, sock, cmd, h, sizeof(*h), 0);
P
Philipp Reisner 已提交
742 743
}

744
static enum drbd_packet drbd_recv_fp(struct drbd_tconn *tconn, struct socket *sock)
P
Philipp Reisner 已提交
745
{
746
	struct p_header80 *h = tconn->data.rbuf;
P
Philipp Reisner 已提交
747 748
	int rr;

749
	rr = drbd_recv_short(sock, h, sizeof(*h), 0);
P
Philipp Reisner 已提交
750

751
	if (rr == sizeof(*h) && h->magic == cpu_to_be32(DRBD_MAGIC))
P
Philipp Reisner 已提交
752 753 754 755 756 757 758 759 760
		return be16_to_cpu(h->command);

	return 0xffff;
}

/**
 * drbd_socket_okay() - Free the socket if its connection is not okay
 * @sock:	pointer to the pointer to the socket.
 */
761
static int drbd_socket_okay(struct socket **sock)
P
Philipp Reisner 已提交
762 763 764 765 766
{
	int rr;
	char tb[4];

	if (!*sock)
767
		return false;
P
Philipp Reisner 已提交
768

769
	rr = drbd_recv_short(*sock, tb, 4, MSG_DONTWAIT | MSG_PEEK);
P
Philipp Reisner 已提交
770 771

	if (rr > 0 || rr == -EAGAIN) {
772
		return true;
P
Philipp Reisner 已提交
773 774 775
	} else {
		sock_release(*sock);
		*sock = NULL;
776
		return false;
P
Philipp Reisner 已提交
777 778
	}
}
779 780 781
/* Gets called if a connection is established, or if a new minor gets created
   in a connection */
int drbd_connected(int vnr, void *p, void *data)
782 783
{
	struct drbd_conf *mdev = (struct drbd_conf *)p;
784
	int err;
785 786 787 788

	atomic_set(&mdev->packet_seq, 0);
	mdev->peer_seq = 0;

789 790 791 792
	mdev->state_mutex = mdev->tconn->agreed_pro_version < 100 ?
		&mdev->tconn->cstate_mutex :
		&mdev->own_state_mutex;

793 794 795 796 797 798 799
	err = drbd_send_sync_param(mdev);
	if (!err)
		err = drbd_send_sizes(mdev, 0, 0);
	if (!err)
		err = drbd_send_uuids(mdev);
	if (!err)
		err = drbd_send_state(mdev);
800 801
	clear_bit(USE_DEGR_WFC_T, &mdev->flags);
	clear_bit(RESIZE_PENDING, &mdev->flags);
802
	return err;
803 804
}

P
Philipp Reisner 已提交
805 806 807 808 809 810 811 812
/*
 * return values:
 *   1 yes, we have a valid connection
 *   0 oops, did not work out, please try again
 *  -1 peer talks different language,
 *     no point in trying again, please go standalone.
 *  -2 We do not have a network config...
 */
813
static int drbd_connect(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
814 815 816 817
{
	struct socket *s, *sock, *msock;
	int try, h, ok;

818
	if (conn_request_state(tconn, NS(conn, C_WF_CONNECTION), CS_VERBOSE) < SS_SUCCESS)
P
Philipp Reisner 已提交
819 820
		return -2;

821
	clear_bit(DISCARD_CONCURRENT, &tconn->flags);
822 823 824

	/* Assume that the peer only understands protocol 80 until we know better.  */
	tconn->agreed_pro_version = 80;
P
Philipp Reisner 已提交
825 826 827 828 829 830 831

	sock  = NULL;
	msock = NULL;

	do {
		for (try = 0;;) {
			/* 3 tries, this should take less than a second! */
832
			s = drbd_try_connect(tconn);
P
Philipp Reisner 已提交
833 834 835
			if (s || ++try >= 3)
				break;
			/* give the other side time to call bind() & listen() */
836
			schedule_timeout_interruptible(HZ / 10);
P
Philipp Reisner 已提交
837 838 839 840
		}

		if (s) {
			if (!sock) {
841
				drbd_send_fp(tconn, s, P_HAND_SHAKE_S);
P
Philipp Reisner 已提交
842 843 844
				sock = s;
				s = NULL;
			} else if (!msock) {
845
				drbd_send_fp(tconn, s, P_HAND_SHAKE_M);
P
Philipp Reisner 已提交
846 847 848
				msock = s;
				s = NULL;
			} else {
849
				conn_err(tconn, "Logic error in drbd_connect()\n");
P
Philipp Reisner 已提交
850 851 852 853 854
				goto out_release_sockets;
			}
		}

		if (sock && msock) {
855
			schedule_timeout_interruptible(tconn->net_conf->ping_timeo*HZ/10);
856 857
			ok = drbd_socket_okay(&sock);
			ok = drbd_socket_okay(&msock) && ok;
P
Philipp Reisner 已提交
858 859 860 861 862
			if (ok)
				break;
		}

retry:
863
		s = drbd_wait_for_connect(tconn);
P
Philipp Reisner 已提交
864
		if (s) {
865
			try = drbd_recv_fp(tconn, s);
866 867
			drbd_socket_okay(&sock);
			drbd_socket_okay(&msock);
P
Philipp Reisner 已提交
868 869 870
			switch (try) {
			case P_HAND_SHAKE_S:
				if (sock) {
871
					conn_warn(tconn, "initial packet S crossed\n");
P
Philipp Reisner 已提交
872 873 874 875 876 877
					sock_release(sock);
				}
				sock = s;
				break;
			case P_HAND_SHAKE_M:
				if (msock) {
878
					conn_warn(tconn, "initial packet M crossed\n");
P
Philipp Reisner 已提交
879 880 881
					sock_release(msock);
				}
				msock = s;
882
				set_bit(DISCARD_CONCURRENT, &tconn->flags);
P
Philipp Reisner 已提交
883 884
				break;
			default:
885
				conn_warn(tconn, "Error receiving initial packet\n");
P
Philipp Reisner 已提交
886 887 888 889 890 891
				sock_release(s);
				if (random32() & 1)
					goto retry;
			}
		}

892
		if (tconn->cstate <= C_DISCONNECTING)
P
Philipp Reisner 已提交
893 894 895 896
			goto out_release_sockets;
		if (signal_pending(current)) {
			flush_signals(current);
			smp_rmb();
897
			if (get_t_state(&tconn->receiver) == EXITING)
P
Philipp Reisner 已提交
898 899 900 901
				goto out_release_sockets;
		}

		if (sock && msock) {
902 903
			ok = drbd_socket_okay(&sock);
			ok = drbd_socket_okay(&msock) && ok;
P
Philipp Reisner 已提交
904 905 906 907 908 909 910 911 912 913 914 915 916 917 918
			if (ok)
				break;
		}
	} while (1);

	msock->sk->sk_reuse = 1; /* SO_REUSEADDR */
	sock->sk->sk_reuse = 1; /* SO_REUSEADDR */

	sock->sk->sk_allocation = GFP_NOIO;
	msock->sk->sk_allocation = GFP_NOIO;

	sock->sk->sk_priority = TC_PRIO_INTERACTIVE_BULK;
	msock->sk->sk_priority = TC_PRIO_INTERACTIVE;

	/* NOT YET ...
919
	 * sock->sk->sk_sndtimeo = tconn->net_conf->timeout*HZ/10;
P
Philipp Reisner 已提交
920 921 922 923
	 * sock->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
	 * first set it to the P_HAND_SHAKE timeout,
	 * which we set to 4x the configured ping_timeout. */
	sock->sk->sk_sndtimeo =
924
	sock->sk->sk_rcvtimeo = tconn->net_conf->ping_timeo*4*HZ/10;
P
Philipp Reisner 已提交
925

926 927
	msock->sk->sk_sndtimeo = tconn->net_conf->timeout*HZ/10;
	msock->sk->sk_rcvtimeo = tconn->net_conf->ping_int*HZ;
P
Philipp Reisner 已提交
928 929

	/* we don't want delays.
L
Lucas De Marchi 已提交
930
	 * we use TCP_CORK where appropriate, though */
P
Philipp Reisner 已提交
931 932 933
	drbd_tcp_nodelay(sock);
	drbd_tcp_nodelay(msock);

934 935 936
	tconn->data.socket = sock;
	tconn->meta.socket = msock;
	tconn->last_received = jiffies;
P
Philipp Reisner 已提交
937

938
	h = drbd_do_handshake(tconn);
P
Philipp Reisner 已提交
939 940 941
	if (h <= 0)
		return h;

942
	if (tconn->cram_hmac_tfm) {
P
Philipp Reisner 已提交
943
		/* drbd_request_state(mdev, NS(conn, WFAuth)); */
944
		switch (drbd_do_auth(tconn)) {
945
		case -1:
946
			conn_err(tconn, "Authentication of peer failed\n");
P
Philipp Reisner 已提交
947
			return -1;
948
		case 0:
949
			conn_err(tconn, "Authentication of peer failed, trying again.\n");
950
			return 0;
P
Philipp Reisner 已提交
951 952 953
		}
	}

954
	if (conn_request_state(tconn, NS(conn, C_WF_REPORT_PARAMS), CS_VERBOSE) < SS_SUCCESS)
P
Philipp Reisner 已提交
955 956
		return 0;

957
	sock->sk->sk_sndtimeo = tconn->net_conf->timeout*HZ/10;
P
Philipp Reisner 已提交
958 959
	sock->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;

960
	drbd_thread_start(&tconn->asender);
P
Philipp Reisner 已提交
961

962
	if (drbd_send_protocol(tconn) == -EOPNOTSUPP)
963
		return -1;
P
Philipp Reisner 已提交
964

965
	return !idr_for_each(&tconn->volumes, drbd_connected, tconn);
P
Philipp Reisner 已提交
966 967 968 969 970 971 972 973 974

out_release_sockets:
	if (sock)
		sock_release(sock);
	if (msock)
		sock_release(msock);
	return -1;
}

975
static int decode_header(struct drbd_tconn *tconn, struct p_header *h, struct packet_info *pi)
P
Philipp Reisner 已提交
976
{
P
Philipp Reisner 已提交
977
	if (h->h80.magic == cpu_to_be32(DRBD_MAGIC)) {
978 979
		pi->cmd = be16_to_cpu(h->h80.command);
		pi->size = be16_to_cpu(h->h80.length);
980
		pi->vnr = 0;
981
	} else if (h->h95.magic == cpu_to_be16(DRBD_MAGIC_BIG)) {
982 983 984
		pi->cmd = be16_to_cpu(h->h95.command);
		pi->size = be32_to_cpu(h->h95.length) & 0x00ffffff;
		pi->vnr = 0;
985
	} else {
986
		conn_err(tconn, "magic?? on data m: 0x%08x c: %d l: %d\n",
987 988 989
		    be32_to_cpu(h->h80.magic),
		    be16_to_cpu(h->h80.command),
		    be16_to_cpu(h->h80.length));
990
		return -EINVAL;
P
Philipp Reisner 已提交
991
	}
992
	return 0;
993 994
}

995
static int drbd_recv_header(struct drbd_tconn *tconn, struct packet_info *pi)
996
{
997
	struct p_header *h = tconn->data.rbuf;
998
	int err;
999

1000 1001
	err = drbd_recv_all_warn(tconn, h, sizeof(*h));
	if (err)
1002
		return err;
1003

1004
	err = decode_header(tconn, h, pi);
1005
	tconn->last_received = jiffies;
P
Philipp Reisner 已提交
1006

1007
	return err;
P
Philipp Reisner 已提交
1008 1009
}

1010
static void drbd_flush(struct drbd_conf *mdev)
P
Philipp Reisner 已提交
1011 1012 1013 1014
{
	int rv;

	if (mdev->write_ordering >= WO_bdev_flush && get_ldev(mdev)) {
1015
		rv = blkdev_issue_flush(mdev->ldev->backing_bdev, GFP_KERNEL,
1016
					NULL);
P
Philipp Reisner 已提交
1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037
		if (rv) {
			dev_err(DEV, "local disk flush failed with status %d\n", rv);
			/* would rather check on EOPNOTSUPP, but that is not reliable.
			 * don't try again for ANY return value != 0
			 * if (rv == -EOPNOTSUPP) */
			drbd_bump_write_ordering(mdev, WO_drain_io);
		}
		put_ldev(mdev);
	}
}

/**
 * drbd_may_finish_epoch() - Applies an epoch_event to the epoch's state, eventually finishes it.
 * @mdev:	DRBD device.
 * @epoch:	Epoch object.
 * @ev:		Epoch event.
 */
static enum finish_epoch drbd_may_finish_epoch(struct drbd_conf *mdev,
					       struct drbd_epoch *epoch,
					       enum epoch_event ev)
{
1038
	int epoch_size;
P
Philipp Reisner 已提交
1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061
	struct drbd_epoch *next_epoch;
	enum finish_epoch rv = FE_STILL_LIVE;

	spin_lock(&mdev->epoch_lock);
	do {
		next_epoch = NULL;

		epoch_size = atomic_read(&epoch->epoch_size);

		switch (ev & ~EV_CLEANUP) {
		case EV_PUT:
			atomic_dec(&epoch->active);
			break;
		case EV_GOT_BARRIER_NR:
			set_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags);
			break;
		case EV_BECAME_LAST:
			/* nothing to do*/
			break;
		}

		if (epoch_size != 0 &&
		    atomic_read(&epoch->active) == 0 &&
1062
		    test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags)) {
P
Philipp Reisner 已提交
1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081
			if (!(ev & EV_CLEANUP)) {
				spin_unlock(&mdev->epoch_lock);
				drbd_send_b_ack(mdev, epoch->barrier_nr, epoch_size);
				spin_lock(&mdev->epoch_lock);
			}
			dec_unacked(mdev);

			if (mdev->current_epoch != epoch) {
				next_epoch = list_entry(epoch->list.next, struct drbd_epoch, list);
				list_del(&epoch->list);
				ev = EV_BECAME_LAST | (ev & EV_CLEANUP);
				mdev->epochs--;
				kfree(epoch);

				if (rv == FE_STILL_LIVE)
					rv = FE_DESTROYED;
			} else {
				epoch->flags = 0;
				atomic_set(&epoch->epoch_size, 0);
1082
				/* atomic_set(&epoch->active, 0); is already zero */
P
Philipp Reisner 已提交
1083 1084
				if (rv == FE_STILL_LIVE)
					rv = FE_RECYCLED;
1085
				wake_up(&mdev->ee_wait);
P
Philipp Reisner 已提交
1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120
			}
		}

		if (!next_epoch)
			break;

		epoch = next_epoch;
	} while (1);

	spin_unlock(&mdev->epoch_lock);

	return rv;
}

/**
 * drbd_bump_write_ordering() - Fall back to an other write ordering method
 * @mdev:	DRBD device.
 * @wo:		Write ordering method to try.
 */
void drbd_bump_write_ordering(struct drbd_conf *mdev, enum write_ordering_e wo) __must_hold(local)
{
	enum write_ordering_e pwo;
	static char *write_ordering_str[] = {
		[WO_none] = "none",
		[WO_drain_io] = "drain",
		[WO_bdev_flush] = "flush",
	};

	pwo = mdev->write_ordering;
	wo = min(pwo, wo);
	if (wo == WO_bdev_flush && mdev->ldev->dc.no_disk_flush)
		wo = WO_drain_io;
	if (wo == WO_drain_io && mdev->ldev->dc.no_disk_drain)
		wo = WO_none;
	mdev->write_ordering = wo;
1121
	if (pwo != mdev->write_ordering || wo == WO_bdev_flush)
P
Philipp Reisner 已提交
1122 1123 1124
		dev_info(DEV, "Method to ensure write ordering: %s\n", write_ordering_str[mdev->write_ordering]);
}

1125
/**
1126
 * drbd_submit_peer_request()
1127
 * @mdev:	DRBD device.
1128
 * @peer_req:	peer request
1129
 * @rw:		flag field, see bio->bi_rw
1130 1131 1132 1133 1134 1135 1136 1137 1138 1139
 *
 * May spread the pages to multiple bios,
 * depending on bio_add_page restrictions.
 *
 * Returns 0 if all bios have been submitted,
 * -ENOMEM if we could not allocate enough bios,
 * -ENOSPC (any better suggestion?) if we have not been able to bio_add_page a
 *  single page to an empty bio (which should never happen and likely indicates
 *  that the lower level IO stack is in some way broken). This has been observed
 *  on certain Xen deployments.
1140 1141
 */
/* TODO allocate from our own bio_set. */
1142 1143 1144
int drbd_submit_peer_request(struct drbd_conf *mdev,
			     struct drbd_peer_request *peer_req,
			     const unsigned rw, const int fault_type)
1145 1146 1147
{
	struct bio *bios = NULL;
	struct bio *bio;
1148 1149 1150
	struct page *page = peer_req->pages;
	sector_t sector = peer_req->i.sector;
	unsigned ds = peer_req->i.size;
1151 1152
	unsigned n_bios = 0;
	unsigned nr_pages = (ds + PAGE_SIZE -1) >> PAGE_SHIFT;
1153
	int err = -ENOMEM;
1154 1155 1156 1157

	/* In most cases, we will only need one bio.  But in case the lower
	 * level restrictions happen to be different at this offset on this
	 * side than those of the sending peer, we may need to submit the
1158 1159 1160 1161 1162
	 * request in more than one bio.
	 *
	 * Plain bio_alloc is good enough here, this is no DRBD internally
	 * generated bio, but a bio allocated on behalf of the peer.
	 */
1163 1164 1165 1166 1167 1168
next_bio:
	bio = bio_alloc(GFP_NOIO, nr_pages);
	if (!bio) {
		dev_err(DEV, "submit_ee: Allocation of a bio failed\n");
		goto fail;
	}
1169
	/* > peer_req->i.sector, unless this is the first bio */
1170 1171 1172
	bio->bi_sector = sector;
	bio->bi_bdev = mdev->ldev->backing_bdev;
	bio->bi_rw = rw;
1173
	bio->bi_private = peer_req;
1174
	bio->bi_end_io = drbd_peer_request_endio;
1175 1176 1177 1178 1179 1180 1181 1182

	bio->bi_next = bios;
	bios = bio;
	++n_bios;

	page_chain_for_each(page) {
		unsigned len = min_t(unsigned, ds, PAGE_SIZE);
		if (!bio_add_page(bio, page, len, 0)) {
1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193
			/* A single page must always be possible!
			 * But in case it fails anyways,
			 * we deal with it, and complain (below). */
			if (bio->bi_vcnt == 0) {
				dev_err(DEV,
					"bio_add_page failed for len=%u, "
					"bi_vcnt=0 (bi_sector=%llu)\n",
					len, (unsigned long long)bio->bi_sector);
				err = -ENOSPC;
				goto fail;
			}
1194 1195 1196 1197 1198 1199 1200 1201 1202
			goto next_bio;
		}
		ds -= len;
		sector += len >> 9;
		--nr_pages;
	}
	D_ASSERT(page == NULL);
	D_ASSERT(ds == 0);

1203
	atomic_set(&peer_req->pending_bios, n_bios);
1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218
	do {
		bio = bios;
		bios = bios->bi_next;
		bio->bi_next = NULL;

		drbd_generic_make_request(mdev, fault_type, bio);
	} while (bios);
	return 0;

fail:
	while (bios) {
		bio = bios;
		bios = bios->bi_next;
		bio_put(bio);
	}
1219
	return err;
1220 1221
}

1222
static void drbd_remove_epoch_entry_interval(struct drbd_conf *mdev,
1223
					     struct drbd_peer_request *peer_req)
1224
{
1225
	struct drbd_interval *i = &peer_req->i;
1226 1227 1228 1229

	drbd_remove_interval(&mdev->write_requests, i);
	drbd_clear_interval(i);

A
Andreas Gruenbacher 已提交
1230
	/* Wake up any processes waiting for this peer request to complete.  */
1231 1232 1233 1234
	if (i->waiting)
		wake_up(&mdev->misc_wait);
}

1235 1236
static int receive_Barrier(struct drbd_conf *mdev, enum drbd_packet cmd,
			   unsigned int data_size)
P
Philipp Reisner 已提交
1237
{
1238
	int rv;
1239
	struct p_barrier *p = mdev->tconn->data.rbuf;
P
Philipp Reisner 已提交
1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254
	struct drbd_epoch *epoch;

	inc_unacked(mdev);

	mdev->current_epoch->barrier_nr = p->barrier;
	rv = drbd_may_finish_epoch(mdev, mdev->current_epoch, EV_GOT_BARRIER_NR);

	/* P_BARRIER_ACK may imply that the corresponding extent is dropped from
	 * the activity log, which means it would not be resynced in case the
	 * R_PRIMARY crashes now.
	 * Therefore we must send the barrier_ack after the barrier request was
	 * completed. */
	switch (mdev->write_ordering) {
	case WO_none:
		if (rv == FE_RECYCLED)
1255
			return 0;
1256 1257 1258 1259 1260 1261 1262 1263 1264

		/* receiver context, in the writeout path of the other node.
		 * avoid potential distributed deadlock */
		epoch = kmalloc(sizeof(struct drbd_epoch), GFP_NOIO);
		if (epoch)
			break;
		else
			dev_warn(DEV, "Allocation of an epoch failed, slowing down\n");
			/* Fall through */
P
Philipp Reisner 已提交
1265 1266 1267 1268

	case WO_bdev_flush:
	case WO_drain_io:
		drbd_wait_ee_list_empty(mdev, &mdev->active_ee);
1269 1270 1271 1272 1273 1274
		drbd_flush(mdev);

		if (atomic_read(&mdev->current_epoch->epoch_size)) {
			epoch = kmalloc(sizeof(struct drbd_epoch), GFP_NOIO);
			if (epoch)
				break;
P
Philipp Reisner 已提交
1275 1276
		}

1277 1278 1279 1280 1281
		epoch = mdev->current_epoch;
		wait_event(mdev->ee_wait, atomic_read(&epoch->epoch_size) == 0);

		D_ASSERT(atomic_read(&epoch->active) == 0);
		D_ASSERT(epoch->flags == 0);
P
Philipp Reisner 已提交
1282

1283
		return 0;
1284 1285
	default:
		dev_err(DEV, "Strangeness in mdev->write_ordering %d\n", mdev->write_ordering);
1286
		return -EIO;
P
Philipp Reisner 已提交
1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303
	}

	epoch->flags = 0;
	atomic_set(&epoch->epoch_size, 0);
	atomic_set(&epoch->active, 0);

	spin_lock(&mdev->epoch_lock);
	if (atomic_read(&mdev->current_epoch->epoch_size)) {
		list_add(&epoch->list, &mdev->current_epoch->list);
		mdev->current_epoch = epoch;
		mdev->epochs++;
	} else {
		/* The current_epoch got recycled while we allocated this one... */
		kfree(epoch);
	}
	spin_unlock(&mdev->epoch_lock);

1304
	return 0;
P
Philipp Reisner 已提交
1305 1306 1307 1308
}

/* used from receive_RSDataReply (recv_resync_read)
 * and from receive_Data */
1309 1310 1311
static struct drbd_peer_request *
read_in_block(struct drbd_conf *mdev, u64 id, sector_t sector,
	      int data_size) __must_hold(local)
P
Philipp Reisner 已提交
1312
{
1313
	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
1314
	struct drbd_peer_request *peer_req;
P
Philipp Reisner 已提交
1315
	struct page *page;
1316
	int dgs, ds, err;
1317 1318
	void *dig_in = mdev->tconn->int_dig_in;
	void *dig_vv = mdev->tconn->int_dig_vv;
1319
	unsigned long *data;
P
Philipp Reisner 已提交
1320

1321 1322
	dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_r_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_r_tfm) : 0;
P
Philipp Reisner 已提交
1323 1324

	if (dgs) {
1325 1326
		err = drbd_recv_all_warn(mdev->tconn, dig_in, dgs);
		if (err)
P
Philipp Reisner 已提交
1327 1328 1329 1330 1331
			return NULL;
	}

	data_size -= dgs;

1332 1333 1334 1335 1336 1337
	if (!expect(data_size != 0))
		return NULL;
	if (!expect(IS_ALIGNED(data_size, 512)))
		return NULL;
	if (!expect(data_size <= DRBD_MAX_BIO_SIZE))
		return NULL;
P
Philipp Reisner 已提交
1338

1339 1340 1341
	/* even though we trust out peer,
	 * we sometimes have to double check. */
	if (sector + (data_size>>9) > capacity) {
1342 1343
		dev_err(DEV, "request from peer beyond end of local disk: "
			"capacity: %llus < sector: %llus + size: %u\n",
1344 1345 1346 1347 1348
			(unsigned long long)capacity,
			(unsigned long long)sector, data_size);
		return NULL;
	}

P
Philipp Reisner 已提交
1349 1350 1351
	/* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD
	 * "criss-cross" setup, that might cause write-out on some other DRBD,
	 * which in turn might block on the other node at this very place.  */
1352 1353
	peer_req = drbd_alloc_ee(mdev, id, sector, data_size, GFP_NOIO);
	if (!peer_req)
P
Philipp Reisner 已提交
1354
		return NULL;
1355

P
Philipp Reisner 已提交
1356
	ds = data_size;
1357
	page = peer_req->pages;
1358 1359
	page_chain_for_each(page) {
		unsigned len = min_t(int, ds, PAGE_SIZE);
1360
		data = kmap(page);
1361
		err = drbd_recv_all_warn(mdev->tconn, data, len);
1362
		if (drbd_insert_fault(mdev, DRBD_FAULT_RECEIVE)) {
1363 1364 1365
			dev_err(DEV, "Fault injection: Corrupting data on receive\n");
			data[0] = data[0] ^ (unsigned long)-1;
		}
P
Philipp Reisner 已提交
1366
		kunmap(page);
1367
		if (err) {
1368
			drbd_free_ee(mdev, peer_req);
P
Philipp Reisner 已提交
1369 1370
			return NULL;
		}
1371
		ds -= len;
P
Philipp Reisner 已提交
1372 1373 1374
	}

	if (dgs) {
1375
		drbd_csum_ee(mdev, mdev->tconn->integrity_r_tfm, peer_req, dig_vv);
P
Philipp Reisner 已提交
1376
		if (memcmp(dig_in, dig_vv, dgs)) {
1377 1378
			dev_err(DEV, "Digest integrity check FAILED: %llus +%u\n",
				(unsigned long long)sector, data_size);
1379
			drbd_free_ee(mdev, peer_req);
P
Philipp Reisner 已提交
1380 1381 1382 1383
			return NULL;
		}
	}
	mdev->recv_cnt += data_size>>9;
1384
	return peer_req;
P
Philipp Reisner 已提交
1385 1386 1387 1388 1389 1390 1391 1392
}

/* drbd_drain_block() just takes a data block
 * out of the socket input buffer, and discards it.
 */
static int drbd_drain_block(struct drbd_conf *mdev, int data_size)
{
	struct page *page;
1393
	int err = 0;
P
Philipp Reisner 已提交
1394 1395
	void *data;

1396
	if (!data_size)
1397
		return 0;
1398

1399
	page = drbd_pp_alloc(mdev, 1, 1);
P
Philipp Reisner 已提交
1400 1401 1402

	data = kmap(page);
	while (data_size) {
1403 1404
		unsigned int len = min_t(int, data_size, PAGE_SIZE);

1405 1406
		err = drbd_recv_all_warn(mdev->tconn, data, len);
		if (err)
P
Philipp Reisner 已提交
1407
			break;
1408
		data_size -= len;
P
Philipp Reisner 已提交
1409 1410
	}
	kunmap(page);
1411
	drbd_pp_free(mdev, page, 0);
1412
	return err;
P
Philipp Reisner 已提交
1413 1414 1415 1416 1417 1418 1419
}

static int recv_dless_read(struct drbd_conf *mdev, struct drbd_request *req,
			   sector_t sector, int data_size)
{
	struct bio_vec *bvec;
	struct bio *bio;
1420
	int dgs, err, i, expect;
1421 1422
	void *dig_in = mdev->tconn->int_dig_in;
	void *dig_vv = mdev->tconn->int_dig_vv;
P
Philipp Reisner 已提交
1423

1424 1425
	dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_r_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_r_tfm) : 0;
P
Philipp Reisner 已提交
1426 1427

	if (dgs) {
1428 1429 1430
		err = drbd_recv_all_warn(mdev->tconn, dig_in, dgs);
		if (err)
			return err;
P
Philipp Reisner 已提交
1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442
	}

	data_size -= dgs;

	/* optimistically update recv_cnt.  if receiving fails below,
	 * we disconnect anyways, and counters will be reset. */
	mdev->recv_cnt += data_size>>9;

	bio = req->master_bio;
	D_ASSERT(sector == bio->bi_sector);

	bio_for_each_segment(bvec, bio, i) {
1443
		void *mapped = kmap(bvec->bv_page) + bvec->bv_offset;
P
Philipp Reisner 已提交
1444
		expect = min_t(int, data_size, bvec->bv_len);
1445
		err = drbd_recv_all_warn(mdev->tconn, mapped, expect);
P
Philipp Reisner 已提交
1446
		kunmap(bvec->bv_page);
1447 1448 1449
		if (err)
			return err;
		data_size -= expect;
P
Philipp Reisner 已提交
1450 1451 1452
	}

	if (dgs) {
1453
		drbd_csum_bio(mdev, mdev->tconn->integrity_r_tfm, bio, dig_vv);
P
Philipp Reisner 已提交
1454 1455
		if (memcmp(dig_in, dig_vv, dgs)) {
			dev_err(DEV, "Digest integrity check FAILED. Broken NICs?\n");
1456
			return -EINVAL;
P
Philipp Reisner 已提交
1457 1458 1459 1460
		}
	}

	D_ASSERT(data_size == 0);
1461
	return 0;
P
Philipp Reisner 已提交
1462 1463 1464 1465
}

/* e_end_resync_block() is called via
 * drbd_process_done_ee() by asender only */
1466
static int e_end_resync_block(struct drbd_work *w, int unused)
P
Philipp Reisner 已提交
1467
{
1468 1469
	struct drbd_peer_request *peer_req =
		container_of(w, struct drbd_peer_request, w);
1470
	struct drbd_conf *mdev = w->mdev;
1471
	sector_t sector = peer_req->i.sector;
1472
	int err;
P
Philipp Reisner 已提交
1473

1474
	D_ASSERT(drbd_interval_empty(&peer_req->i));
P
Philipp Reisner 已提交
1475

1476 1477
	if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
		drbd_set_in_sync(mdev, sector, peer_req->i.size);
1478
		err = drbd_send_ack(mdev, P_RS_WRITE_ACK, peer_req);
P
Philipp Reisner 已提交
1479 1480
	} else {
		/* Record failure to sync */
1481
		drbd_rs_failed_io(mdev, sector, peer_req->i.size);
P
Philipp Reisner 已提交
1482

1483
		err  = drbd_send_ack(mdev, P_NEG_ACK, peer_req);
P
Philipp Reisner 已提交
1484 1485 1486
	}
	dec_unacked(mdev);

1487
	return err;
P
Philipp Reisner 已提交
1488 1489 1490 1491
}

static int recv_resync_read(struct drbd_conf *mdev, sector_t sector, int data_size) __releases(local)
{
1492
	struct drbd_peer_request *peer_req;
P
Philipp Reisner 已提交
1493

1494 1495
	peer_req = read_in_block(mdev, ID_SYNCER, sector, data_size);
	if (!peer_req)
1496
		goto fail;
P
Philipp Reisner 已提交
1497 1498 1499 1500 1501 1502 1503

	dec_rs_pending(mdev);

	inc_unacked(mdev);
	/* corresponding dec_unacked() in e_end_resync_block()
	 * respective _drbd_clear_done_ee */

1504
	peer_req->w.cb = e_end_resync_block;
1505

1506
	spin_lock_irq(&mdev->tconn->req_lock);
1507
	list_add(&peer_req->w.list, &mdev->sync_ee);
1508
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1509

1510
	atomic_add(data_size >> 9, &mdev->rs_sect_ev);
1511
	if (drbd_submit_peer_request(mdev, peer_req, WRITE, DRBD_FAULT_RS_WR) == 0)
1512
		return 0;
P
Philipp Reisner 已提交
1513

1514 1515
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
1516
	spin_lock_irq(&mdev->tconn->req_lock);
1517
	list_del(&peer_req->w.list);
1518
	spin_unlock_irq(&mdev->tconn->req_lock);
1519

1520
	drbd_free_ee(mdev, peer_req);
1521 1522
fail:
	put_ldev(mdev);
1523
	return -EIO;
P
Philipp Reisner 已提交
1524 1525
}

1526
static struct drbd_request *
1527 1528
find_request(struct drbd_conf *mdev, struct rb_root *root, u64 id,
	     sector_t sector, bool missing_ok, const char *func)
1529 1530 1531
{
	struct drbd_request *req;

1532 1533
	/* Request object according to our peer */
	req = (struct drbd_request *)(unsigned long)id;
1534
	if (drbd_contains_interval(root, sector, &req->i) && req->i.local)
1535
		return req;
1536 1537 1538 1539
	if (!missing_ok) {
		dev_err(DEV, "%s: failed to find request %lu, sector %llus\n", func,
			(unsigned long)id, (unsigned long long)sector);
	}
1540 1541 1542
	return NULL;
}

1543 1544
static int receive_DataReply(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
1545 1546 1547
{
	struct drbd_request *req;
	sector_t sector;
1548
	int err;
1549
	struct p_data *p = mdev->tconn->data.rbuf;
P
Philipp Reisner 已提交
1550 1551 1552

	sector = be64_to_cpu(p->sector);

1553
	spin_lock_irq(&mdev->tconn->req_lock);
1554
	req = find_request(mdev, &mdev->read_requests, p->block_id, sector, false, __func__);
1555
	spin_unlock_irq(&mdev->tconn->req_lock);
1556
	if (unlikely(!req))
1557
		return -EIO;
P
Philipp Reisner 已提交
1558

B
Bart Van Assche 已提交
1559
	/* hlist_del(&req->collision) is done in _req_may_be_done, to avoid
P
Philipp Reisner 已提交
1560 1561
	 * special casing it there for the various failure cases.
	 * still no race with drbd_fail_pending_reads */
1562 1563
	err = recv_dless_read(mdev, req, sector, data_size);
	if (!err)
1564
		req_mod(req, DATA_RECEIVED);
P
Philipp Reisner 已提交
1565 1566 1567 1568
	/* else: nothing. handled from drbd_disconnect...
	 * I don't think we may complete this just yet
	 * in case we are "on-disconnect: freeze" */

1569
	return err;
P
Philipp Reisner 已提交
1570 1571
}

1572 1573
static int receive_RSDataReply(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int data_size)
P
Philipp Reisner 已提交
1574 1575
{
	sector_t sector;
1576
	int err;
1577
	struct p_data *p = mdev->tconn->data.rbuf;
P
Philipp Reisner 已提交
1578 1579 1580 1581 1582 1583 1584

	sector = be64_to_cpu(p->sector);
	D_ASSERT(p->block_id == ID_SYNCER);

	if (get_ldev(mdev)) {
		/* data is submitted to disk within recv_resync_read.
		 * corresponding put_ldev done below on error,
1585
		 * or in drbd_peer_request_endio. */
1586
		err = recv_resync_read(mdev, sector, data_size);
P
Philipp Reisner 已提交
1587 1588 1589 1590
	} else {
		if (__ratelimit(&drbd_ratelimit_state))
			dev_err(DEV, "Can not write resync data to local disk.\n");

1591
		err = drbd_drain_block(mdev, data_size);
P
Philipp Reisner 已提交
1592

1593
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
P
Philipp Reisner 已提交
1594 1595
	}

1596 1597
	atomic_add(data_size >> 9, &mdev->rs_sect_in);

1598
	return err;
P
Philipp Reisner 已提交
1599 1600
}

1601
static int w_restart_write(struct drbd_work *w, int cancel)
1602 1603 1604 1605 1606 1607 1608 1609 1610 1611
{
	struct drbd_request *req = container_of(w, struct drbd_request, w);
	struct drbd_conf *mdev = w->mdev;
	struct bio *bio;
	unsigned long start_time;
	unsigned long flags;

	spin_lock_irqsave(&mdev->tconn->req_lock, flags);
	if (!expect(req->rq_state & RQ_POSTPONED)) {
		spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
1612
		return -EIO;
1613 1614 1615 1616 1617 1618 1619 1620 1621
	}
	bio = req->master_bio;
	start_time = req->start_time;
	/* Postponed requests will not have their master_bio completed!  */
	__req_mod(req, DISCARD_WRITE, NULL);
	spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);

	while (__drbd_make_request(mdev, bio, start_time))
		/* retry */ ;
1622
	return 0;
1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645
}

static void restart_conflicting_writes(struct drbd_conf *mdev,
				       sector_t sector, int size)
{
	struct drbd_interval *i;
	struct drbd_request *req;

	drbd_for_each_overlap(i, &mdev->write_requests, sector, size) {
		if (!i->local)
			continue;
		req = container_of(i, struct drbd_request, i);
		if (req->rq_state & RQ_LOCAL_PENDING ||
		    !(req->rq_state & RQ_POSTPONED))
			continue;
		if (expect(list_empty(&req->w.list))) {
			req->w.mdev = mdev;
			req->w.cb = w_restart_write;
			drbd_queue_work(&mdev->tconn->data.work, &req->w);
		}
	}
}

P
Philipp Reisner 已提交
1646 1647 1648
/* e_end_block() is called via drbd_process_done_ee().
 * this means this function only runs in the asender thread
 */
1649
static int e_end_block(struct drbd_work *w, int cancel)
P
Philipp Reisner 已提交
1650
{
1651 1652
	struct drbd_peer_request *peer_req =
		container_of(w, struct drbd_peer_request, w);
1653
	struct drbd_conf *mdev = w->mdev;
1654
	sector_t sector = peer_req->i.sector;
1655
	int err = 0, pcmd;
P
Philipp Reisner 已提交
1656

1657
	if (mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C) {
1658
		if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
P
Philipp Reisner 已提交
1659 1660
			pcmd = (mdev->state.conn >= C_SYNC_SOURCE &&
				mdev->state.conn <= C_PAUSED_SYNC_T &&
1661
				peer_req->flags & EE_MAY_SET_IN_SYNC) ?
P
Philipp Reisner 已提交
1662
				P_RS_WRITE_ACK : P_WRITE_ACK;
1663
			err = drbd_send_ack(mdev, pcmd, peer_req);
P
Philipp Reisner 已提交
1664
			if (pcmd == P_RS_WRITE_ACK)
1665
				drbd_set_in_sync(mdev, sector, peer_req->i.size);
P
Philipp Reisner 已提交
1666
		} else {
1667
			err = drbd_send_ack(mdev, P_NEG_ACK, peer_req);
P
Philipp Reisner 已提交
1668 1669 1670 1671 1672 1673 1674
			/* we expect it to be marked out of sync anyways...
			 * maybe assert this?  */
		}
		dec_unacked(mdev);
	}
	/* we delete from the conflict detection hash _after_ we sent out the
	 * P_WRITE_ACK / P_NEG_ACK, to get the sequence number right.  */
1675
	if (mdev->tconn->net_conf->two_primaries) {
1676
		spin_lock_irq(&mdev->tconn->req_lock);
1677 1678
		D_ASSERT(!drbd_interval_empty(&peer_req->i));
		drbd_remove_epoch_entry_interval(mdev, peer_req);
1679 1680
		if (peer_req->flags & EE_RESTART_REQUESTS)
			restart_conflicting_writes(mdev, sector, peer_req->i.size);
1681
		spin_unlock_irq(&mdev->tconn->req_lock);
1682
	} else
1683
		D_ASSERT(drbd_interval_empty(&peer_req->i));
P
Philipp Reisner 已提交
1684

1685
	drbd_may_finish_epoch(mdev, peer_req->epoch, EV_PUT + (cancel ? EV_CLEANUP : 0));
P
Philipp Reisner 已提交
1686

1687
	return err;
P
Philipp Reisner 已提交
1688 1689
}

1690
static int e_send_ack(struct drbd_work *w, enum drbd_packet ack)
P
Philipp Reisner 已提交
1691
{
1692
	struct drbd_conf *mdev = w->mdev;
1693 1694
	struct drbd_peer_request *peer_req =
		container_of(w, struct drbd_peer_request, w);
1695
	int err;
P
Philipp Reisner 已提交
1696

1697
	err = drbd_send_ack(mdev, ack, peer_req);
P
Philipp Reisner 已提交
1698 1699
	dec_unacked(mdev);

1700
	return err;
P
Philipp Reisner 已提交
1701 1702
}

1703
static int e_send_discard_write(struct drbd_work *w, int unused)
1704 1705 1706 1707
{
	return e_send_ack(w, P_DISCARD_WRITE);
}

1708
static int e_send_retry_write(struct drbd_work *w, int unused)
1709 1710 1711 1712 1713 1714 1715
{
	struct drbd_tconn *tconn = w->mdev->tconn;

	return e_send_ack(w, tconn->agreed_pro_version >= 100 ?
			     P_RETRY_WRITE : P_DISCARD_WRITE);
}

1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730
static bool seq_greater(u32 a, u32 b)
{
	/*
	 * We assume 32-bit wrap-around here.
	 * For 24-bit wrap-around, we would have to shift:
	 *  a <<= 8; b <<= 8;
	 */
	return (s32)a - (s32)b > 0;
}

static u32 seq_max(u32 a, u32 b)
{
	return seq_greater(a, b) ? a : b;
}

1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743
static bool need_peer_seq(struct drbd_conf *mdev)
{
	struct drbd_tconn *tconn = mdev->tconn;

	/*
	 * We only need to keep track of the last packet_seq number of our peer
	 * if we are in dual-primary mode and we have the discard flag set; see
	 * handle_write_conflicts().
	 */
	return tconn->net_conf->two_primaries &&
	       test_bit(DISCARD_CONCURRENT, &tconn->flags);
}

1744
static void update_peer_seq(struct drbd_conf *mdev, unsigned int peer_seq)
1745
{
1746
	unsigned int newest_peer_seq;
1747

1748 1749
	if (need_peer_seq(mdev)) {
		spin_lock(&mdev->peer_seq_lock);
1750 1751
		newest_peer_seq = seq_max(mdev->peer_seq, peer_seq);
		mdev->peer_seq = newest_peer_seq;
1752
		spin_unlock(&mdev->peer_seq_lock);
1753 1754
		/* wake up only if we actually changed mdev->peer_seq */
		if (peer_seq == newest_peer_seq)
1755 1756
			wake_up(&mdev->seq_wait);
	}
1757 1758
}

P
Philipp Reisner 已提交
1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779
/* Called from receive_Data.
 * Synchronize packets on sock with packets on msock.
 *
 * This is here so even when a P_DATA packet traveling via sock overtook an Ack
 * packet traveling on msock, they are still processed in the order they have
 * been sent.
 *
 * Note: we don't care for Ack packets overtaking P_DATA packets.
 *
 * In case packet_seq is larger than mdev->peer_seq number, there are
 * outstanding packets on the msock. We wait for them to arrive.
 * In case we are the logically next packet, we update mdev->peer_seq
 * ourselves. Correctly handles 32bit wrap around.
 *
 * Assume we have a 10 GBit connection, that is about 1<<30 byte per second,
 * about 1<<21 sectors per second. So "worst" case, we have 1<<3 == 8 seconds
 * for the 24bit wrap (historical atomic_t guarantee on some archs), and we have
 * 1<<9 == 512 seconds aka ages for the 32bit wrap around...
 *
 * returns 0 if we may process the packet,
 * -ERESTARTSYS if we were interrupted (by disconnect signal). */
1780
static int wait_for_and_update_peer_seq(struct drbd_conf *mdev, const u32 peer_seq)
P
Philipp Reisner 已提交
1781 1782 1783
{
	DEFINE_WAIT(wait);
	long timeout;
1784 1785 1786 1787 1788
	int ret;

	if (!need_peer_seq(mdev))
		return 0;

P
Philipp Reisner 已提交
1789 1790
	spin_lock(&mdev->peer_seq_lock);
	for (;;) {
1791 1792 1793
		if (!seq_greater(peer_seq - 1, mdev->peer_seq)) {
			mdev->peer_seq = seq_max(mdev->peer_seq, peer_seq);
			ret = 0;
P
Philipp Reisner 已提交
1794
			break;
1795
		}
P
Philipp Reisner 已提交
1796 1797 1798 1799
		if (signal_pending(current)) {
			ret = -ERESTARTSYS;
			break;
		}
1800
		prepare_to_wait(&mdev->seq_wait, &wait, TASK_INTERRUPTIBLE);
P
Philipp Reisner 已提交
1801
		spin_unlock(&mdev->peer_seq_lock);
1802 1803
		timeout = mdev->tconn->net_conf->ping_timeo*HZ/10;
		timeout = schedule_timeout(timeout);
P
Philipp Reisner 已提交
1804
		spin_lock(&mdev->peer_seq_lock);
1805
		if (!timeout) {
P
Philipp Reisner 已提交
1806
			ret = -ETIMEDOUT;
1807
			dev_err(DEV, "Timed out waiting for missing ack packets; disconnecting\n");
P
Philipp Reisner 已提交
1808 1809 1810 1811
			break;
		}
	}
	spin_unlock(&mdev->peer_seq_lock);
1812
	finish_wait(&mdev->seq_wait, &wait);
P
Philipp Reisner 已提交
1813 1814 1815
	return ret;
}

1816 1817 1818 1819
/* see also bio_flags_to_wire()
 * DRBD_REQ_*, because we need to semantically map the flags to data packet
 * flags and back. We may replicate to other kernel versions. */
static unsigned long wire_flags_to_bio(struct drbd_conf *mdev, u32 dpf)
1820
{
1821 1822 1823 1824
	return  (dpf & DP_RW_SYNC ? REQ_SYNC : 0) |
		(dpf & DP_FUA ? REQ_FUA : 0) |
		(dpf & DP_FLUSH ? REQ_FLUSH : 0) |
		(dpf & DP_DISCARD ? REQ_DISCARD : 0);
1825 1826
}

1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959
static void fail_postponed_requests(struct drbd_conf *mdev, sector_t sector,
				    unsigned int size)
{
	struct drbd_interval *i;

    repeat:
	drbd_for_each_overlap(i, &mdev->write_requests, sector, size) {
		struct drbd_request *req;
		struct bio_and_error m;

		if (!i->local)
			continue;
		req = container_of(i, struct drbd_request, i);
		if (!(req->rq_state & RQ_POSTPONED))
			continue;
		req->rq_state &= ~RQ_POSTPONED;
		__req_mod(req, NEG_ACKED, &m);
		spin_unlock_irq(&mdev->tconn->req_lock);
		if (m.bio)
			complete_master_bio(mdev, &m);
		spin_lock_irq(&mdev->tconn->req_lock);
		goto repeat;
	}
}

static int handle_write_conflicts(struct drbd_conf *mdev,
				  struct drbd_peer_request *peer_req)
{
	struct drbd_tconn *tconn = mdev->tconn;
	bool resolve_conflicts = test_bit(DISCARD_CONCURRENT, &tconn->flags);
	sector_t sector = peer_req->i.sector;
	const unsigned int size = peer_req->i.size;
	struct drbd_interval *i;
	bool equal;
	int err;

	/*
	 * Inserting the peer request into the write_requests tree will prevent
	 * new conflicting local requests from being added.
	 */
	drbd_insert_interval(&mdev->write_requests, &peer_req->i);

    repeat:
	drbd_for_each_overlap(i, &mdev->write_requests, sector, size) {
		if (i == &peer_req->i)
			continue;

		if (!i->local) {
			/*
			 * Our peer has sent a conflicting remote request; this
			 * should not happen in a two-node setup.  Wait for the
			 * earlier peer request to complete.
			 */
			err = drbd_wait_misc(mdev, i);
			if (err)
				goto out;
			goto repeat;
		}

		equal = i->sector == sector && i->size == size;
		if (resolve_conflicts) {
			/*
			 * If the peer request is fully contained within the
			 * overlapping request, it can be discarded; otherwise,
			 * it will be retried once all overlapping requests
			 * have completed.
			 */
			bool discard = i->sector <= sector && i->sector +
				       (i->size >> 9) >= sector + (size >> 9);

			if (!equal)
				dev_alert(DEV, "Concurrent writes detected: "
					       "local=%llus +%u, remote=%llus +%u, "
					       "assuming %s came first\n",
					  (unsigned long long)i->sector, i->size,
					  (unsigned long long)sector, size,
					  discard ? "local" : "remote");

			inc_unacked(mdev);
			peer_req->w.cb = discard ? e_send_discard_write :
						   e_send_retry_write;
			list_add_tail(&peer_req->w.list, &mdev->done_ee);
			wake_asender(mdev->tconn);

			err = -ENOENT;
			goto out;
		} else {
			struct drbd_request *req =
				container_of(i, struct drbd_request, i);

			if (!equal)
				dev_alert(DEV, "Concurrent writes detected: "
					       "local=%llus +%u, remote=%llus +%u\n",
					  (unsigned long long)i->sector, i->size,
					  (unsigned long long)sector, size);

			if (req->rq_state & RQ_LOCAL_PENDING ||
			    !(req->rq_state & RQ_POSTPONED)) {
				/*
				 * Wait for the node with the discard flag to
				 * decide if this request will be discarded or
				 * retried.  Requests that are discarded will
				 * disappear from the write_requests tree.
				 *
				 * In addition, wait for the conflicting
				 * request to finish locally before submitting
				 * the conflicting peer request.
				 */
				err = drbd_wait_misc(mdev, &req->i);
				if (err) {
					_conn_request_state(mdev->tconn,
							    NS(conn, C_TIMEOUT),
							    CS_HARD);
					fail_postponed_requests(mdev, sector, size);
					goto out;
				}
				goto repeat;
			}
			/*
			 * Remember to restart the conflicting requests after
			 * the new peer request has completed.
			 */
			peer_req->flags |= EE_RESTART_REQUESTS;
		}
	}
	err = 0;

    out:
	if (err)
		drbd_remove_epoch_entry_interval(mdev, peer_req);
	return err;
}

P
Philipp Reisner 已提交
1960
/* mirrored write */
1961 1962
static int receive_Data(struct drbd_conf *mdev, enum drbd_packet cmd,
			unsigned int data_size)
P
Philipp Reisner 已提交
1963 1964
{
	sector_t sector;
1965
	struct drbd_peer_request *peer_req;
1966
	struct p_data *p = mdev->tconn->data.rbuf;
1967
	u32 peer_seq = be32_to_cpu(p->seq_num);
P
Philipp Reisner 已提交
1968 1969
	int rw = WRITE;
	u32 dp_flags;
1970
	int err;
P
Philipp Reisner 已提交
1971

1972
	if (!get_ldev(mdev)) {
1973 1974
		int err2;

1975
		err = wait_for_and_update_peer_seq(mdev, peer_seq);
1976
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
P
Philipp Reisner 已提交
1977
		atomic_inc(&mdev->current_epoch->epoch_size);
1978 1979 1980 1981
		err2 = drbd_drain_block(mdev, data_size);
		if (!err)
			err = err2;
		return err;
P
Philipp Reisner 已提交
1982 1983
	}

1984 1985 1986 1987 1988
	/*
	 * Corresponding put_ldev done either below (on various errors), or in
	 * drbd_peer_request_endio, if we successfully submit the data at the
	 * end of this function.
	 */
P
Philipp Reisner 已提交
1989 1990

	sector = be64_to_cpu(p->sector);
1991 1992
	peer_req = read_in_block(mdev, p->block_id, sector, data_size);
	if (!peer_req) {
P
Philipp Reisner 已提交
1993
		put_ldev(mdev);
1994
		return -EIO;
P
Philipp Reisner 已提交
1995 1996
	}

1997
	peer_req->w.cb = e_end_block;
P
Philipp Reisner 已提交
1998

1999 2000 2001 2002
	dp_flags = be32_to_cpu(p->dp_flags);
	rw |= wire_flags_to_bio(mdev, dp_flags);

	if (dp_flags & DP_MAY_SET_IN_SYNC)
2003
		peer_req->flags |= EE_MAY_SET_IN_SYNC;
2004

P
Philipp Reisner 已提交
2005
	spin_lock(&mdev->epoch_lock);
2006 2007 2008
	peer_req->epoch = mdev->current_epoch;
	atomic_inc(&peer_req->epoch->epoch_size);
	atomic_inc(&peer_req->epoch->active);
P
Philipp Reisner 已提交
2009 2010
	spin_unlock(&mdev->epoch_lock);

2011 2012 2013
	if (mdev->tconn->net_conf->two_primaries) {
		err = wait_for_and_update_peer_seq(mdev, peer_seq);
		if (err)
P
Philipp Reisner 已提交
2014
			goto out_interrupted;
2015
		spin_lock_irq(&mdev->tconn->req_lock);
2016 2017 2018 2019
		err = handle_write_conflicts(mdev, peer_req);
		if (err) {
			spin_unlock_irq(&mdev->tconn->req_lock);
			if (err == -ENOENT) {
P
Philipp Reisner 已提交
2020
				put_ldev(mdev);
2021
				return 0;
P
Philipp Reisner 已提交
2022
			}
2023
			goto out_interrupted;
P
Philipp Reisner 已提交
2024
		}
2025 2026
	} else
		spin_lock_irq(&mdev->tconn->req_lock);
2027
	list_add(&peer_req->w.list, &mdev->active_ee);
2028
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
2029

2030
	switch (mdev->tconn->net_conf->wire_protocol) {
P
Philipp Reisner 已提交
2031 2032 2033 2034 2035 2036 2037 2038
	case DRBD_PROT_C:
		inc_unacked(mdev);
		/* corresponding dec_unacked() in e_end_block()
		 * respective _drbd_clear_done_ee */
		break;
	case DRBD_PROT_B:
		/* I really don't like it that the receiver thread
		 * sends on the msock, but anyways */
2039
		drbd_send_ack(mdev, P_RECV_ACK, peer_req);
P
Philipp Reisner 已提交
2040 2041 2042 2043 2044 2045
		break;
	case DRBD_PROT_A:
		/* nothing to do */
		break;
	}

2046
	if (mdev->state.pdsk < D_INCONSISTENT) {
P
Philipp Reisner 已提交
2047
		/* In case we have the only disk of the cluster, */
2048 2049 2050 2051
		drbd_set_out_of_sync(mdev, peer_req->i.sector, peer_req->i.size);
		peer_req->flags |= EE_CALL_AL_COMPLETE_IO;
		peer_req->flags &= ~EE_MAY_SET_IN_SYNC;
		drbd_al_begin_io(mdev, peer_req->i.sector);
P
Philipp Reisner 已提交
2052 2053
	}

2054 2055 2056
	err = drbd_submit_peer_request(mdev, peer_req, rw, DRBD_FAULT_DT_WR);
	if (!err)
		return 0;
P
Philipp Reisner 已提交
2057

2058 2059
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
2060
	spin_lock_irq(&mdev->tconn->req_lock);
2061 2062
	list_del(&peer_req->w.list);
	drbd_remove_epoch_entry_interval(mdev, peer_req);
2063
	spin_unlock_irq(&mdev->tconn->req_lock);
2064 2065
	if (peer_req->flags & EE_CALL_AL_COMPLETE_IO)
		drbd_al_complete_io(mdev, peer_req->i.sector);
2066

P
Philipp Reisner 已提交
2067
out_interrupted:
2068
	drbd_may_finish_epoch(mdev, peer_req->epoch, EV_PUT + EV_CLEANUP);
P
Philipp Reisner 已提交
2069
	put_ldev(mdev);
2070
	drbd_free_ee(mdev, peer_req);
2071
	return err;
P
Philipp Reisner 已提交
2072 2073
}

2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084
/* We may throttle resync, if the lower device seems to be busy,
 * and current sync rate is above c_min_rate.
 *
 * To decide whether or not the lower device is busy, we use a scheme similar
 * to MD RAID is_mddev_idle(): if the partition stats reveal "significant"
 * (more than 64 sectors) of activity we cannot account for with our own resync
 * activity, it obviously is "busy".
 *
 * The current sync rate used here uses only the most recent two step marks,
 * to have a short time average so we can react faster.
 */
2085
int drbd_rs_should_slow_down(struct drbd_conf *mdev, sector_t sector)
2086 2087 2088
{
	struct gendisk *disk = mdev->ldev->backing_bdev->bd_contains->bd_disk;
	unsigned long db, dt, dbdt;
2089
	struct lc_element *tmp;
2090 2091 2092 2093
	int curr_events;
	int throttle = 0;

	/* feature disabled? */
2094
	if (mdev->ldev->dc.c_min_rate == 0)
2095 2096
		return 0;

2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108
	spin_lock_irq(&mdev->al_lock);
	tmp = lc_find(mdev->resync, BM_SECT_TO_EXT(sector));
	if (tmp) {
		struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce);
		if (test_bit(BME_PRIORITY, &bm_ext->flags)) {
			spin_unlock_irq(&mdev->al_lock);
			return 0;
		}
		/* Do not slow down if app IO is already waiting for this extent */
	}
	spin_unlock_irq(&mdev->al_lock);

2109 2110 2111
	curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
		      (int)part_stat_read(&disk->part0, sectors[1]) -
			atomic_read(&mdev->rs_sect_ev);
2112

2113 2114 2115 2116 2117 2118 2119 2120
	if (!mdev->rs_last_events || curr_events - mdev->rs_last_events > 64) {
		unsigned long rs_left;
		int i;

		mdev->rs_last_events = curr_events;

		/* sync speed average over the last 2*DRBD_SYNC_MARK_STEP,
		 * approx. */
2121 2122 2123 2124 2125 2126
		i = (mdev->rs_last_mark + DRBD_SYNC_MARKS-1) % DRBD_SYNC_MARKS;

		if (mdev->state.conn == C_VERIFY_S || mdev->state.conn == C_VERIFY_T)
			rs_left = mdev->ov_left;
		else
			rs_left = drbd_bm_total_weight(mdev) - mdev->rs_failed;
2127 2128 2129 2130 2131 2132 2133

		dt = ((long)jiffies - (long)mdev->rs_mark_time[i]) / HZ;
		if (!dt)
			dt++;
		db = mdev->rs_mark_left[i] - rs_left;
		dbdt = Bit2KB(db/dt);

2134
		if (dbdt > mdev->ldev->dc.c_min_rate)
2135 2136 2137 2138 2139 2140
			throttle = 1;
	}
	return throttle;
}


2141 2142
static int receive_DataRequest(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int digest_size)
P
Philipp Reisner 已提交
2143 2144 2145
{
	sector_t sector;
	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
2146
	struct drbd_peer_request *peer_req;
P
Philipp Reisner 已提交
2147
	struct digest_info *di = NULL;
2148
	int size, verb;
P
Philipp Reisner 已提交
2149
	unsigned int fault_type;
2150
	struct p_block_req *p =	mdev->tconn->data.rbuf;
P
Philipp Reisner 已提交
2151 2152 2153 2154

	sector = be64_to_cpu(p->sector);
	size   = be32_to_cpu(p->blksize);

2155
	if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
P
Philipp Reisner 已提交
2156 2157
		dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
				(unsigned long long)sector, size);
2158
		return -EINVAL;
P
Philipp Reisner 已提交
2159 2160 2161 2162
	}
	if (sector + (size>>9) > capacity) {
		dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
				(unsigned long long)sector, size);
2163
		return -EINVAL;
P
Philipp Reisner 已提交
2164 2165 2166
	}

	if (!get_ldev_if_state(mdev, D_UP_TO_DATE)) {
2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186
		verb = 1;
		switch (cmd) {
		case P_DATA_REQUEST:
			drbd_send_ack_rp(mdev, P_NEG_DREPLY, p);
			break;
		case P_RS_DATA_REQUEST:
		case P_CSUM_RS_REQUEST:
		case P_OV_REQUEST:
			drbd_send_ack_rp(mdev, P_NEG_RS_DREPLY , p);
			break;
		case P_OV_REPLY:
			verb = 0;
			dec_rs_pending(mdev);
			drbd_send_ack_ex(mdev, P_OV_RESULT, sector, size, ID_IN_SYNC);
			break;
		default:
			dev_err(DEV, "unexpected command (%s) in receive_DataRequest\n",
				cmdname(cmd));
		}
		if (verb && __ratelimit(&drbd_ratelimit_state))
P
Philipp Reisner 已提交
2187 2188
			dev_err(DEV, "Can not satisfy peer's read request, "
			    "no local data.\n");
2189

L
Lars Ellenberg 已提交
2190
		/* drain possibly payload */
2191
		return drbd_drain_block(mdev, digest_size);
P
Philipp Reisner 已提交
2192 2193 2194 2195 2196
	}

	/* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD
	 * "criss-cross" setup, that might cause write-out on some other DRBD,
	 * which in turn might block on the other node at this very place.  */
2197 2198
	peer_req = drbd_alloc_ee(mdev, p->block_id, sector, size, GFP_NOIO);
	if (!peer_req) {
P
Philipp Reisner 已提交
2199
		put_ldev(mdev);
2200
		return -ENOMEM;
P
Philipp Reisner 已提交
2201 2202
	}

2203
	switch (cmd) {
P
Philipp Reisner 已提交
2204
	case P_DATA_REQUEST:
2205
		peer_req->w.cb = w_e_end_data_req;
P
Philipp Reisner 已提交
2206
		fault_type = DRBD_FAULT_DT_RD;
2207 2208 2209
		/* application IO, don't drbd_rs_begin_io */
		goto submit;

P
Philipp Reisner 已提交
2210
	case P_RS_DATA_REQUEST:
2211
		peer_req->w.cb = w_e_end_rsdata_req;
P
Philipp Reisner 已提交
2212
		fault_type = DRBD_FAULT_RS_RD;
2213 2214
		/* used in the sector offset progress display */
		mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
P
Philipp Reisner 已提交
2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226
		break;

	case P_OV_REPLY:
	case P_CSUM_RS_REQUEST:
		fault_type = DRBD_FAULT_RS_RD;
		di = kmalloc(sizeof(*di) + digest_size, GFP_NOIO);
		if (!di)
			goto out_free_e;

		di->digest_size = digest_size;
		di->digest = (((char *)di)+sizeof(struct digest_info));

2227 2228
		peer_req->digest = di;
		peer_req->flags |= EE_HAS_DIGEST;
2229

2230
		if (drbd_recv(mdev->tconn, di->digest, digest_size) != digest_size)
P
Philipp Reisner 已提交
2231 2232
			goto out_free_e;

2233
		if (cmd == P_CSUM_RS_REQUEST) {
2234
			D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
2235
			peer_req->w.cb = w_e_end_csum_rs_req;
2236 2237
			/* used in the sector offset progress display */
			mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
2238
		} else if (cmd == P_OV_REPLY) {
2239 2240
			/* track progress, we may need to throttle */
			atomic_add(size >> 9, &mdev->rs_sect_in);
2241
			peer_req->w.cb = w_e_end_ov_reply;
P
Philipp Reisner 已提交
2242
			dec_rs_pending(mdev);
2243 2244 2245
			/* drbd_rs_begin_io done when we sent this request,
			 * but accounting still needs to be done. */
			goto submit_for_resync;
P
Philipp Reisner 已提交
2246 2247 2248 2249 2250
		}
		break;

	case P_OV_REQUEST:
		if (mdev->ov_start_sector == ~(sector_t)0 &&
2251
		    mdev->tconn->agreed_pro_version >= 90) {
2252 2253
			unsigned long now = jiffies;
			int i;
P
Philipp Reisner 已提交
2254 2255
			mdev->ov_start_sector = sector;
			mdev->ov_position = sector;
2256 2257
			mdev->ov_left = drbd_bm_bits(mdev) - BM_SECT_TO_BIT(sector);
			mdev->rs_total = mdev->ov_left;
2258 2259 2260 2261
			for (i = 0; i < DRBD_SYNC_MARKS; i++) {
				mdev->rs_mark_left[i] = mdev->ov_left;
				mdev->rs_mark_time[i] = now;
			}
P
Philipp Reisner 已提交
2262 2263 2264
			dev_info(DEV, "Online Verify start sector: %llu\n",
					(unsigned long long)sector);
		}
2265
		peer_req->w.cb = w_e_end_ov_req;
P
Philipp Reisner 已提交
2266 2267 2268 2269 2270
		fault_type = DRBD_FAULT_RS_RD;
		break;

	default:
		dev_err(DEV, "unexpected command (%s) in receive_DataRequest\n",
2271
		    cmdname(cmd));
P
Philipp Reisner 已提交
2272
		fault_type = DRBD_FAULT_MAX;
2273
		goto out_free_e;
P
Philipp Reisner 已提交
2274 2275
	}

2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297
	/* Throttle, drbd_rs_begin_io and submit should become asynchronous
	 * wrt the receiver, but it is not as straightforward as it may seem.
	 * Various places in the resync start and stop logic assume resync
	 * requests are processed in order, requeuing this on the worker thread
	 * introduces a bunch of new code for synchronization between threads.
	 *
	 * Unlimited throttling before drbd_rs_begin_io may stall the resync
	 * "forever", throttling after drbd_rs_begin_io will lock that extent
	 * for application writes for the same time.  For now, just throttle
	 * here, where the rest of the code expects the receiver to sleep for
	 * a while, anyways.
	 */

	/* Throttle before drbd_rs_begin_io, as that locks out application IO;
	 * this defers syncer requests for some time, before letting at least
	 * on request through.  The resync controller on the receiving side
	 * will adapt to the incoming rate accordingly.
	 *
	 * We cannot throttle here if remote is Primary/SyncTarget:
	 * we would also throttle its application reads.
	 * In that case, throttling is done on the SyncTarget only.
	 */
2298 2299 2300
	if (mdev->state.peer != R_PRIMARY && drbd_rs_should_slow_down(mdev, sector))
		schedule_timeout_uninterruptible(HZ/10);
	if (drbd_rs_begin_io(mdev, sector))
2301
		goto out_free_e;
P
Philipp Reisner 已提交
2302

2303 2304 2305
submit_for_resync:
	atomic_add(size >> 9, &mdev->rs_sect_ev);

2306
submit:
P
Philipp Reisner 已提交
2307
	inc_unacked(mdev);
2308
	spin_lock_irq(&mdev->tconn->req_lock);
2309
	list_add_tail(&peer_req->w.list, &mdev->read_ee);
2310
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
2311

2312
	if (drbd_submit_peer_request(mdev, peer_req, READ, fault_type) == 0)
2313
		return 0;
P
Philipp Reisner 已提交
2314

2315 2316
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
2317
	spin_lock_irq(&mdev->tconn->req_lock);
2318
	list_del(&peer_req->w.list);
2319
	spin_unlock_irq(&mdev->tconn->req_lock);
2320 2321
	/* no drbd_rs_complete_io(), we are dropping the connection anyways */

P
Philipp Reisner 已提交
2322 2323
out_free_e:
	put_ldev(mdev);
2324
	drbd_free_ee(mdev, peer_req);
2325
	return -EIO;
P
Philipp Reisner 已提交
2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338
}

static int drbd_asb_recover_0p(struct drbd_conf *mdev) __must_hold(local)
{
	int self, peer, rv = -100;
	unsigned long ch_self, ch_peer;

	self = mdev->ldev->md.uuid[UI_BITMAP] & 1;
	peer = mdev->p_uuid[UI_BITMAP] & 1;

	ch_peer = mdev->p_uuid[UI_SIZE];
	ch_self = mdev->comm_bm_set;

2339
	switch (mdev->tconn->net_conf->after_sb_0p) {
P
Philipp Reisner 已提交
2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366
	case ASB_CONSENSUS:
	case ASB_DISCARD_SECONDARY:
	case ASB_CALL_HELPER:
		dev_err(DEV, "Configuration error.\n");
		break;
	case ASB_DISCONNECT:
		break;
	case ASB_DISCARD_YOUNGER_PRI:
		if (self == 0 && peer == 1) {
			rv = -1;
			break;
		}
		if (self == 1 && peer == 0) {
			rv =  1;
			break;
		}
		/* Else fall through to one of the other strategies... */
	case ASB_DISCARD_OLDER_PRI:
		if (self == 0 && peer == 1) {
			rv = 1;
			break;
		}
		if (self == 1 && peer == 0) {
			rv = -1;
			break;
		}
		/* Else fall through to one of the other strategies... */
L
Lars Ellenberg 已提交
2367
		dev_warn(DEV, "Discard younger/older primary did not find a decision\n"
P
Philipp Reisner 已提交
2368 2369 2370
		     "Using discard-least-changes instead\n");
	case ASB_DISCARD_ZERO_CHG:
		if (ch_peer == 0 && ch_self == 0) {
2371
			rv = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags)
P
Philipp Reisner 已提交
2372 2373 2374 2375 2376 2377
				? -1 : 1;
			break;
		} else {
			if (ch_peer == 0) { rv =  1; break; }
			if (ch_self == 0) { rv = -1; break; }
		}
2378
		if (mdev->tconn->net_conf->after_sb_0p == ASB_DISCARD_ZERO_CHG)
P
Philipp Reisner 已提交
2379 2380 2381 2382 2383 2384 2385 2386
			break;
	case ASB_DISCARD_LEAST_CHG:
		if	(ch_self < ch_peer)
			rv = -1;
		else if (ch_self > ch_peer)
			rv =  1;
		else /* ( ch_self == ch_peer ) */
		     /* Well, then use something else. */
2387
			rv = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags)
P
Philipp Reisner 已提交
2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401
				? -1 : 1;
		break;
	case ASB_DISCARD_LOCAL:
		rv = -1;
		break;
	case ASB_DISCARD_REMOTE:
		rv =  1;
	}

	return rv;
}

static int drbd_asb_recover_1p(struct drbd_conf *mdev) __must_hold(local)
{
2402
	int hg, rv = -100;
P
Philipp Reisner 已提交
2403

2404
	switch (mdev->tconn->net_conf->after_sb_1p) {
P
Philipp Reisner 已提交
2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428
	case ASB_DISCARD_YOUNGER_PRI:
	case ASB_DISCARD_OLDER_PRI:
	case ASB_DISCARD_LEAST_CHG:
	case ASB_DISCARD_LOCAL:
	case ASB_DISCARD_REMOTE:
		dev_err(DEV, "Configuration error.\n");
		break;
	case ASB_DISCONNECT:
		break;
	case ASB_CONSENSUS:
		hg = drbd_asb_recover_0p(mdev);
		if (hg == -1 && mdev->state.role == R_SECONDARY)
			rv = hg;
		if (hg == 1  && mdev->state.role == R_PRIMARY)
			rv = hg;
		break;
	case ASB_VIOLENTLY:
		rv = drbd_asb_recover_0p(mdev);
		break;
	case ASB_DISCARD_SECONDARY:
		return mdev->state.role == R_PRIMARY ? 1 : -1;
	case ASB_CALL_HELPER:
		hg = drbd_asb_recover_0p(mdev);
		if (hg == -1 && mdev->state.role == R_PRIMARY) {
2429 2430 2431
			enum drbd_state_rv rv2;

			drbd_set_role(mdev, R_SECONDARY, 0);
P
Philipp Reisner 已提交
2432 2433 2434
			 /* drbd_change_state() does not sleep while in SS_IN_TRANSIENT_STATE,
			  * we might be here in C_WF_REPORT_PARAMS which is transient.
			  * we do not need to wait for the after state change work either. */
2435 2436
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
P
Philipp Reisner 已提交
2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450
				drbd_khelper(mdev, "pri-lost-after-sb");
			} else {
				dev_warn(DEV, "Successfully gave up primary role.\n");
				rv = hg;
			}
		} else
			rv = hg;
	}

	return rv;
}

static int drbd_asb_recover_2p(struct drbd_conf *mdev) __must_hold(local)
{
2451
	int hg, rv = -100;
P
Philipp Reisner 已提交
2452

2453
	switch (mdev->tconn->net_conf->after_sb_2p) {
P
Philipp Reisner 已提交
2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470
	case ASB_DISCARD_YOUNGER_PRI:
	case ASB_DISCARD_OLDER_PRI:
	case ASB_DISCARD_LEAST_CHG:
	case ASB_DISCARD_LOCAL:
	case ASB_DISCARD_REMOTE:
	case ASB_CONSENSUS:
	case ASB_DISCARD_SECONDARY:
		dev_err(DEV, "Configuration error.\n");
		break;
	case ASB_VIOLENTLY:
		rv = drbd_asb_recover_0p(mdev);
		break;
	case ASB_DISCONNECT:
		break;
	case ASB_CALL_HELPER:
		hg = drbd_asb_recover_0p(mdev);
		if (hg == -1) {
2471 2472
			enum drbd_state_rv rv2;

P
Philipp Reisner 已提交
2473 2474 2475
			 /* drbd_change_state() does not sleep while in SS_IN_TRANSIENT_STATE,
			  * we might be here in C_WF_REPORT_PARAMS which is transient.
			  * we do not need to wait for the after state change work either. */
2476 2477
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
P
Philipp Reisner 已提交
2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515
				drbd_khelper(mdev, "pri-lost-after-sb");
			} else {
				dev_warn(DEV, "Successfully gave up primary role.\n");
				rv = hg;
			}
		} else
			rv = hg;
	}

	return rv;
}

static void drbd_uuid_dump(struct drbd_conf *mdev, char *text, u64 *uuid,
			   u64 bits, u64 flags)
{
	if (!uuid) {
		dev_info(DEV, "%s uuid info vanished while I was looking!\n", text);
		return;
	}
	dev_info(DEV, "%s %016llX:%016llX:%016llX:%016llX bits:%llu flags:%llX\n",
	     text,
	     (unsigned long long)uuid[UI_CURRENT],
	     (unsigned long long)uuid[UI_BITMAP],
	     (unsigned long long)uuid[UI_HISTORY_START],
	     (unsigned long long)uuid[UI_HISTORY_END],
	     (unsigned long long)bits,
	     (unsigned long long)flags);
}

/*
  100	after split brain try auto recover
    2	C_SYNC_SOURCE set BitMap
    1	C_SYNC_SOURCE use BitMap
    0	no Sync
   -1	C_SYNC_TARGET use BitMap
   -2	C_SYNC_TARGET set BitMap
 -100	after split brain, disconnect
-1000	unrelated data
2516 2517
-1091   requires proto 91
-1096   requires proto 96
P
Philipp Reisner 已提交
2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545
 */
static int drbd_uuid_compare(struct drbd_conf *mdev, int *rule_nr) __must_hold(local)
{
	u64 self, peer;
	int i, j;

	self = mdev->ldev->md.uuid[UI_CURRENT] & ~((u64)1);
	peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);

	*rule_nr = 10;
	if (self == UUID_JUST_CREATED && peer == UUID_JUST_CREATED)
		return 0;

	*rule_nr = 20;
	if ((self == UUID_JUST_CREATED || self == (u64)0) &&
	     peer != UUID_JUST_CREATED)
		return -2;

	*rule_nr = 30;
	if (self != UUID_JUST_CREATED &&
	    (peer == UUID_JUST_CREATED || peer == (u64)0))
		return 2;

	if (self == peer) {
		int rct, dc; /* roles at crash time */

		if (mdev->p_uuid[UI_BITMAP] == (u64)0 && mdev->ldev->md.uuid[UI_BITMAP] != (u64)0) {

2546
			if (mdev->tconn->agreed_pro_version < 91)
2547
				return -1091;
P
Philipp Reisner 已提交
2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566

			if ((mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1)) == (mdev->p_uuid[UI_HISTORY_START] & ~((u64)1)) &&
			    (mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (mdev->p_uuid[UI_HISTORY_START + 1] & ~((u64)1))) {
				dev_info(DEV, "was SyncSource, missed the resync finished event, corrected myself:\n");
				drbd_uuid_set_bm(mdev, 0UL);

				drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid,
					       mdev->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(mdev) : 0, 0);
				*rule_nr = 34;
			} else {
				dev_info(DEV, "was SyncSource (peer failed to write sync_uuid)\n");
				*rule_nr = 36;
			}

			return 1;
		}

		if (mdev->ldev->md.uuid[UI_BITMAP] == (u64)0 && mdev->p_uuid[UI_BITMAP] != (u64)0) {

2567
			if (mdev->tconn->agreed_pro_version < 91)
2568
				return -1091;
P
Philipp Reisner 已提交
2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599

			if ((mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (mdev->p_uuid[UI_BITMAP] & ~((u64)1)) &&
			    (mdev->ldev->md.uuid[UI_HISTORY_START + 1] & ~((u64)1)) == (mdev->p_uuid[UI_HISTORY_START] & ~((u64)1))) {
				dev_info(DEV, "was SyncTarget, peer missed the resync finished event, corrected peer:\n");

				mdev->p_uuid[UI_HISTORY_START + 1] = mdev->p_uuid[UI_HISTORY_START];
				mdev->p_uuid[UI_HISTORY_START] = mdev->p_uuid[UI_BITMAP];
				mdev->p_uuid[UI_BITMAP] = 0UL;

				drbd_uuid_dump(mdev, "peer", mdev->p_uuid, mdev->p_uuid[UI_SIZE], mdev->p_uuid[UI_FLAGS]);
				*rule_nr = 35;
			} else {
				dev_info(DEV, "was SyncTarget (failed to write sync_uuid)\n");
				*rule_nr = 37;
			}

			return -1;
		}

		/* Common power [off|failure] */
		rct = (test_bit(CRASHED_PRIMARY, &mdev->flags) ? 1 : 0) +
			(mdev->p_uuid[UI_FLAGS] & 2);
		/* lowest bit is set when we were primary,
		 * next bit (weight 2) is set when peer was primary */
		*rule_nr = 40;

		switch (rct) {
		case 0: /* !self_pri && !peer_pri */ return 0;
		case 1: /*  self_pri && !peer_pri */ return 1;
		case 2: /* !self_pri &&  peer_pri */ return -1;
		case 3: /*  self_pri &&  peer_pri */
2600
			dc = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags);
P
Philipp Reisner 已提交
2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612
			return dc ? -1 : 1;
		}
	}

	*rule_nr = 50;
	peer = mdev->p_uuid[UI_BITMAP] & ~((u64)1);
	if (self == peer)
		return -1;

	*rule_nr = 51;
	peer = mdev->p_uuid[UI_HISTORY_START] & ~((u64)1);
	if (self == peer) {
2613
		if (mdev->tconn->agreed_pro_version < 96 ?
2614 2615 2616
		    (mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) ==
		    (mdev->p_uuid[UI_HISTORY_START + 1] & ~((u64)1)) :
		    peer + UUID_NEW_BM_OFFSET == (mdev->p_uuid[UI_BITMAP] & ~((u64)1))) {
P
Philipp Reisner 已提交
2617 2618 2619
			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of the peer's UUIDs. */

2620
			if (mdev->tconn->agreed_pro_version < 91)
2621
				return -1091;
P
Philipp Reisner 已提交
2622 2623 2624

			mdev->p_uuid[UI_BITMAP] = mdev->p_uuid[UI_HISTORY_START];
			mdev->p_uuid[UI_HISTORY_START] = mdev->p_uuid[UI_HISTORY_START + 1];
2625 2626 2627 2628

			dev_info(DEV, "Did not got last syncUUID packet, corrected:\n");
			drbd_uuid_dump(mdev, "peer", mdev->p_uuid, mdev->p_uuid[UI_SIZE], mdev->p_uuid[UI_FLAGS]);

P
Philipp Reisner 已提交
2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649
			return -1;
		}
	}

	*rule_nr = 60;
	self = mdev->ldev->md.uuid[UI_CURRENT] & ~((u64)1);
	for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) {
		peer = mdev->p_uuid[i] & ~((u64)1);
		if (self == peer)
			return -2;
	}

	*rule_nr = 70;
	self = mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1);
	peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);
	if (self == peer)
		return 1;

	*rule_nr = 71;
	self = mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1);
	if (self == peer) {
2650
		if (mdev->tconn->agreed_pro_version < 96 ?
2651 2652 2653
		    (mdev->ldev->md.uuid[UI_HISTORY_START + 1] & ~((u64)1)) ==
		    (mdev->p_uuid[UI_HISTORY_START] & ~((u64)1)) :
		    self + UUID_NEW_BM_OFFSET == (mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1))) {
P
Philipp Reisner 已提交
2654 2655 2656
			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of our UUIDs. */

2657
			if (mdev->tconn->agreed_pro_version < 91)
2658
				return -1091;
P
Philipp Reisner 已提交
2659 2660 2661 2662

			_drbd_uuid_set(mdev, UI_BITMAP, mdev->ldev->md.uuid[UI_HISTORY_START]);
			_drbd_uuid_set(mdev, UI_HISTORY_START, mdev->ldev->md.uuid[UI_HISTORY_START + 1]);

2663
			dev_info(DEV, "Last syncUUID did not get through, corrected:\n");
P
Philipp Reisner 已提交
2664 2665 2666 2667 2668 2669 2670 2671 2672
			drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid,
				       mdev->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(mdev) : 0, 0);

			return 1;
		}
	}


	*rule_nr = 80;
2673
	peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);
P
Philipp Reisner 已提交
2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725
	for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) {
		self = mdev->ldev->md.uuid[i] & ~((u64)1);
		if (self == peer)
			return 2;
	}

	*rule_nr = 90;
	self = mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1);
	peer = mdev->p_uuid[UI_BITMAP] & ~((u64)1);
	if (self == peer && self != ((u64)0))
		return 100;

	*rule_nr = 100;
	for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) {
		self = mdev->ldev->md.uuid[i] & ~((u64)1);
		for (j = UI_HISTORY_START; j <= UI_HISTORY_END; j++) {
			peer = mdev->p_uuid[j] & ~((u64)1);
			if (self == peer)
				return -100;
		}
	}

	return -1000;
}

/* drbd_sync_handshake() returns the new conn state on success, or
   CONN_MASK (-1) on failure.
 */
static enum drbd_conns drbd_sync_handshake(struct drbd_conf *mdev, enum drbd_role peer_role,
					   enum drbd_disk_state peer_disk) __must_hold(local)
{
	int hg, rule_nr;
	enum drbd_conns rv = C_MASK;
	enum drbd_disk_state mydisk;

	mydisk = mdev->state.disk;
	if (mydisk == D_NEGOTIATING)
		mydisk = mdev->new_state_tmp.disk;

	dev_info(DEV, "drbd_sync_handshake:\n");
	drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid, mdev->comm_bm_set, 0);
	drbd_uuid_dump(mdev, "peer", mdev->p_uuid,
		       mdev->p_uuid[UI_SIZE], mdev->p_uuid[UI_FLAGS]);

	hg = drbd_uuid_compare(mdev, &rule_nr);

	dev_info(DEV, "uuid_compare()=%d by rule %d\n", hg, rule_nr);

	if (hg == -1000) {
		dev_alert(DEV, "Unrelated data, aborting!\n");
		return C_MASK;
	}
2726 2727
	if (hg < -1000) {
		dev_alert(DEV, "To resolve this both sides have to support at least protocol %d\n", -hg - 1000);
P
Philipp Reisner 已提交
2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740
		return C_MASK;
	}

	if    ((mydisk == D_INCONSISTENT && peer_disk > D_INCONSISTENT) ||
	    (peer_disk == D_INCONSISTENT && mydisk    > D_INCONSISTENT)) {
		int f = (hg == -100) || abs(hg) == 2;
		hg = mydisk > D_INCONSISTENT ? 1 : -1;
		if (f)
			hg = hg*2;
		dev_info(DEV, "Becoming sync %s due to disk states.\n",
		     hg > 0 ? "source" : "target");
	}

2741 2742 2743
	if (abs(hg) == 100)
		drbd_khelper(mdev, "initial-split-brain");

2744
	if (hg == 100 || (hg == -100 && mdev->tconn->net_conf->always_asbp)) {
P
Philipp Reisner 已提交
2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772
		int pcount = (mdev->state.role == R_PRIMARY)
			   + (peer_role == R_PRIMARY);
		int forced = (hg == -100);

		switch (pcount) {
		case 0:
			hg = drbd_asb_recover_0p(mdev);
			break;
		case 1:
			hg = drbd_asb_recover_1p(mdev);
			break;
		case 2:
			hg = drbd_asb_recover_2p(mdev);
			break;
		}
		if (abs(hg) < 100) {
			dev_warn(DEV, "Split-Brain detected, %d primaries, "
			     "automatically solved. Sync from %s node\n",
			     pcount, (hg < 0) ? "peer" : "this");
			if (forced) {
				dev_warn(DEV, "Doing a full sync, since"
				     " UUIDs where ambiguous.\n");
				hg = hg*2;
			}
		}
	}

	if (hg == -100) {
2773
		if (mdev->tconn->net_conf->want_lose && !(mdev->p_uuid[UI_FLAGS]&1))
P
Philipp Reisner 已提交
2774
			hg = -1;
2775
		if (!mdev->tconn->net_conf->want_lose && (mdev->p_uuid[UI_FLAGS]&1))
P
Philipp Reisner 已提交
2776 2777 2778 2779 2780 2781 2782 2783 2784
			hg = 1;

		if (abs(hg) < 100)
			dev_warn(DEV, "Split-Brain detected, manually solved. "
			     "Sync from %s node\n",
			     (hg < 0) ? "peer" : "this");
	}

	if (hg == -100) {
2785 2786 2787 2788
		/* FIXME this log message is not correct if we end up here
		 * after an attempted attach on a diskless node.
		 * We just refuse to attach -- well, we drop the "connection"
		 * to that disk, in a way... */
2789
		dev_alert(DEV, "Split-Brain detected but unresolved, dropping connection!\n");
P
Philipp Reisner 已提交
2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800
		drbd_khelper(mdev, "split-brain");
		return C_MASK;
	}

	if (hg > 0 && mydisk <= D_INCONSISTENT) {
		dev_err(DEV, "I shall become SyncSource, but I am inconsistent!\n");
		return C_MASK;
	}

	if (hg < 0 && /* by intention we do not use mydisk here. */
	    mdev->state.role == R_PRIMARY && mdev->state.disk >= D_CONSISTENT) {
2801
		switch (mdev->tconn->net_conf->rr_conflict) {
P
Philipp Reisner 已提交
2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813
		case ASB_CALL_HELPER:
			drbd_khelper(mdev, "pri-lost");
			/* fall through */
		case ASB_DISCONNECT:
			dev_err(DEV, "I shall become SyncTarget, but I am primary!\n");
			return C_MASK;
		case ASB_VIOLENTLY:
			dev_warn(DEV, "Becoming SyncTarget, violating the stable-data"
			     "assumption\n");
		}
	}

2814
	if (mdev->tconn->net_conf->dry_run || test_bit(CONN_DRY_RUN, &mdev->tconn->flags)) {
2815 2816 2817 2818 2819 2820 2821 2822 2823
		if (hg == 0)
			dev_info(DEV, "dry-run connect: No resync, would become Connected immediately.\n");
		else
			dev_info(DEV, "dry-run connect: Would become %s, doing a %s resync.",
				 drbd_conn_str(hg > 0 ? C_SYNC_SOURCE : C_SYNC_TARGET),
				 abs(hg) >= 2 ? "full" : "bit-map based");
		return C_MASK;
	}

P
Philipp Reisner 已提交
2824 2825
	if (abs(hg) >= 2) {
		dev_info(DEV, "Writing the whole bitmap, full sync required after drbd_sync_handshake.\n");
2826 2827
		if (drbd_bitmap_io(mdev, &drbd_bmio_set_n_write, "set_n_write from sync_handshake",
					BM_LOCKED_SET_ALLOWED))
P
Philipp Reisner 已提交
2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866
			return C_MASK;
	}

	if (hg > 0) { /* become sync source. */
		rv = C_WF_BITMAP_S;
	} else if (hg < 0) { /* become sync target */
		rv = C_WF_BITMAP_T;
	} else {
		rv = C_CONNECTED;
		if (drbd_bm_total_weight(mdev)) {
			dev_info(DEV, "No resync, but %lu bits in bitmap!\n",
			     drbd_bm_total_weight(mdev));
		}
	}

	return rv;
}

/* returns 1 if invalid */
static int cmp_after_sb(enum drbd_after_sb_p peer, enum drbd_after_sb_p self)
{
	/* ASB_DISCARD_REMOTE - ASB_DISCARD_LOCAL is valid */
	if ((peer == ASB_DISCARD_REMOTE && self == ASB_DISCARD_LOCAL) ||
	    (self == ASB_DISCARD_REMOTE && peer == ASB_DISCARD_LOCAL))
		return 0;

	/* any other things with ASB_DISCARD_REMOTE or ASB_DISCARD_LOCAL are invalid */
	if (peer == ASB_DISCARD_REMOTE || peer == ASB_DISCARD_LOCAL ||
	    self == ASB_DISCARD_REMOTE || self == ASB_DISCARD_LOCAL)
		return 1;

	/* everything else is valid if they are equal on both sides. */
	if (peer == self)
		return 0;

	/* everything es is invalid. */
	return 1;
}

2867
static int receive_protocol(struct drbd_tconn *tconn, enum drbd_packet cmd,
2868
			    unsigned int data_size)
P
Philipp Reisner 已提交
2869
{
2870
	struct p_protocol *p = tconn->data.rbuf;
P
Philipp Reisner 已提交
2871
	int p_proto, p_after_sb_0p, p_after_sb_1p, p_after_sb_2p;
2872
	int p_want_lose, p_two_primaries, cf;
P
Philipp Reisner 已提交
2873 2874 2875 2876 2877 2878 2879
	char p_integrity_alg[SHARED_SECRET_MAX] = "";

	p_proto		= be32_to_cpu(p->protocol);
	p_after_sb_0p	= be32_to_cpu(p->after_sb_0p);
	p_after_sb_1p	= be32_to_cpu(p->after_sb_1p);
	p_after_sb_2p	= be32_to_cpu(p->after_sb_2p);
	p_two_primaries = be32_to_cpu(p->two_primaries);
2880 2881 2882
	cf		= be32_to_cpu(p->conn_flags);
	p_want_lose = cf & CF_WANT_LOSE;

2883
	clear_bit(CONN_DRY_RUN, &tconn->flags);
2884 2885

	if (cf & CF_DRY_RUN)
2886
		set_bit(CONN_DRY_RUN, &tconn->flags);
P
Philipp Reisner 已提交
2887

2888 2889
	if (p_proto != tconn->net_conf->wire_protocol) {
		conn_err(tconn, "incompatible communication protocols\n");
P
Philipp Reisner 已提交
2890 2891 2892
		goto disconnect;
	}

2893 2894
	if (cmp_after_sb(p_after_sb_0p, tconn->net_conf->after_sb_0p)) {
		conn_err(tconn, "incompatible after-sb-0pri settings\n");
P
Philipp Reisner 已提交
2895 2896 2897
		goto disconnect;
	}

2898 2899
	if (cmp_after_sb(p_after_sb_1p, tconn->net_conf->after_sb_1p)) {
		conn_err(tconn, "incompatible after-sb-1pri settings\n");
P
Philipp Reisner 已提交
2900 2901 2902
		goto disconnect;
	}

2903 2904
	if (cmp_after_sb(p_after_sb_2p, tconn->net_conf->after_sb_2p)) {
		conn_err(tconn, "incompatible after-sb-2pri settings\n");
P
Philipp Reisner 已提交
2905 2906 2907
		goto disconnect;
	}

2908 2909
	if (p_want_lose && tconn->net_conf->want_lose) {
		conn_err(tconn, "both sides have the 'want_lose' flag set\n");
P
Philipp Reisner 已提交
2910 2911 2912
		goto disconnect;
	}

2913 2914
	if (p_two_primaries != tconn->net_conf->two_primaries) {
		conn_err(tconn, "incompatible setting of the two-primaries options\n");
P
Philipp Reisner 已提交
2915 2916 2917
		goto disconnect;
	}

2918 2919
	if (tconn->agreed_pro_version >= 87) {
		unsigned char *my_alg = tconn->net_conf->integrity_alg;
2920
		int err;
P
Philipp Reisner 已提交
2921

2922 2923 2924
		err = drbd_recv_all(tconn, p_integrity_alg, data_size);
		if (err)
			return err;
P
Philipp Reisner 已提交
2925 2926 2927

		p_integrity_alg[SHARED_SECRET_MAX-1] = 0;
		if (strcmp(p_integrity_alg, my_alg)) {
2928
			conn_err(tconn, "incompatible setting of the data-integrity-alg\n");
P
Philipp Reisner 已提交
2929 2930
			goto disconnect;
		}
2931
		conn_info(tconn, "data-integrity-alg: %s\n",
P
Philipp Reisner 已提交
2932 2933 2934
		     my_alg[0] ? my_alg : (unsigned char *)"<not-used>");
	}

2935
	return 0;
P
Philipp Reisner 已提交
2936 2937

disconnect:
2938
	conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
2939
	return -EIO;
P
Philipp Reisner 已提交
2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968
}

/* helper function
 * input: alg name, feature name
 * return: NULL (alg name was "")
 *         ERR_PTR(error) if something goes wrong
 *         or the crypto hash ptr, if it worked out ok. */
struct crypto_hash *drbd_crypto_alloc_digest_safe(const struct drbd_conf *mdev,
		const char *alg, const char *name)
{
	struct crypto_hash *tfm;

	if (!alg[0])
		return NULL;

	tfm = crypto_alloc_hash(alg, 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(tfm)) {
		dev_err(DEV, "Can not allocate \"%s\" as %s (reason: %ld)\n",
			alg, name, PTR_ERR(tfm));
		return tfm;
	}
	if (!drbd_crypto_is_hash(crypto_hash_tfm(tfm))) {
		crypto_free_hash(tfm);
		dev_err(DEV, "\"%s\" is not a digest (%s)\n", alg, name);
		return ERR_PTR(-EINVAL);
	}
	return tfm;
}

2969 2970
static int receive_SyncParam(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int packet_size)
P
Philipp Reisner 已提交
2971
{
2972
	struct p_rs_param_95 *p = mdev->tconn->data.rbuf;
P
Philipp Reisner 已提交
2973 2974 2975
	unsigned int header_size, data_size, exp_max_sz;
	struct crypto_hash *verify_tfm = NULL;
	struct crypto_hash *csums_tfm = NULL;
2976
	const int apv = mdev->tconn->agreed_pro_version;
2977 2978
	int *rs_plan_s = NULL;
	int fifo_size = 0;
2979
	int err;
P
Philipp Reisner 已提交
2980 2981 2982 2983

	exp_max_sz  = apv <= 87 ? sizeof(struct p_rs_param)
		    : apv == 88 ? sizeof(struct p_rs_param)
					+ SHARED_SECRET_MAX
2984 2985
		    : apv <= 94 ? sizeof(struct p_rs_param_89)
		    : /* apv >= 95 */ sizeof(struct p_rs_param_95);
P
Philipp Reisner 已提交
2986

2987
	if (packet_size > exp_max_sz) {
P
Philipp Reisner 已提交
2988
		dev_err(DEV, "SyncParam packet too long: received %u, expected <= %u bytes\n",
2989
		    packet_size, exp_max_sz);
2990
		return -EIO;
P
Philipp Reisner 已提交
2991 2992 2993
	}

	if (apv <= 88) {
2994
		header_size = sizeof(struct p_rs_param) - sizeof(struct p_header);
2995
		data_size   = packet_size  - header_size;
2996
	} else if (apv <= 94) {
2997
		header_size = sizeof(struct p_rs_param_89) - sizeof(struct p_header);
2998
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
2999
		D_ASSERT(data_size == 0);
3000
	} else {
3001
		header_size = sizeof(struct p_rs_param_95) - sizeof(struct p_header);
3002
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
3003 3004 3005 3006 3007 3008
		D_ASSERT(data_size == 0);
	}

	/* initialize verify_alg and csums_alg */
	memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);

3009 3010 3011
	err = drbd_recv_all(mdev->tconn, &p->head.payload, header_size);
	if (err)
		return err;
P
Philipp Reisner 已提交
3012

3013 3014 3015 3016
	if (get_ldev(mdev)) {
		mdev->ldev->dc.resync_rate = be32_to_cpu(p->rate);
		put_ldev(mdev);
	}
P
Philipp Reisner 已提交
3017 3018 3019 3020 3021 3022 3023

	if (apv >= 88) {
		if (apv == 88) {
			if (data_size > SHARED_SECRET_MAX) {
				dev_err(DEV, "verify-alg too long, "
				    "peer wants %u, accepting only %u byte\n",
						data_size, SHARED_SECRET_MAX);
3024
				return -EIO;
P
Philipp Reisner 已提交
3025 3026
			}

3027 3028 3029
			err = drbd_recv_all(mdev->tconn, p->verify_alg, data_size);
			if (err)
				return err;
P
Philipp Reisner 已提交
3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044

			/* we expect NUL terminated string */
			/* but just in case someone tries to be evil */
			D_ASSERT(p->verify_alg[data_size-1] == 0);
			p->verify_alg[data_size-1] = 0;

		} else /* apv >= 89 */ {
			/* we still expect NUL terminated strings */
			/* but just in case someone tries to be evil */
			D_ASSERT(p->verify_alg[SHARED_SECRET_MAX-1] == 0);
			D_ASSERT(p->csums_alg[SHARED_SECRET_MAX-1] == 0);
			p->verify_alg[SHARED_SECRET_MAX-1] = 0;
			p->csums_alg[SHARED_SECRET_MAX-1] = 0;
		}

3045
		if (strcmp(mdev->tconn->net_conf->verify_alg, p->verify_alg)) {
P
Philipp Reisner 已提交
3046 3047
			if (mdev->state.conn == C_WF_REPORT_PARAMS) {
				dev_err(DEV, "Different verify-alg settings. me=\"%s\" peer=\"%s\"\n",
3048
				    mdev->tconn->net_conf->verify_alg, p->verify_alg);
P
Philipp Reisner 已提交
3049 3050 3051 3052 3053 3054 3055 3056 3057 3058
				goto disconnect;
			}
			verify_tfm = drbd_crypto_alloc_digest_safe(mdev,
					p->verify_alg, "verify-alg");
			if (IS_ERR(verify_tfm)) {
				verify_tfm = NULL;
				goto disconnect;
			}
		}

3059
		if (apv >= 89 && strcmp(mdev->tconn->net_conf->csums_alg, p->csums_alg)) {
P
Philipp Reisner 已提交
3060 3061
			if (mdev->state.conn == C_WF_REPORT_PARAMS) {
				dev_err(DEV, "Different csums-alg settings. me=\"%s\" peer=\"%s\"\n",
3062
				    mdev->tconn->net_conf->csums_alg, p->csums_alg);
P
Philipp Reisner 已提交
3063 3064 3065 3066 3067 3068 3069 3070 3071 3072
				goto disconnect;
			}
			csums_tfm = drbd_crypto_alloc_digest_safe(mdev,
					p->csums_alg, "csums-alg");
			if (IS_ERR(csums_tfm)) {
				csums_tfm = NULL;
				goto disconnect;
			}
		}

3073 3074 3075 3076 3077 3078
		if (apv > 94 && get_ldev(mdev)) {
			mdev->ldev->dc.resync_rate = be32_to_cpu(p->rate);
			mdev->ldev->dc.c_plan_ahead = be32_to_cpu(p->c_plan_ahead);
			mdev->ldev->dc.c_delay_target = be32_to_cpu(p->c_delay_target);
			mdev->ldev->dc.c_fill_target = be32_to_cpu(p->c_fill_target);
			mdev->ldev->dc.c_max_rate = be32_to_cpu(p->c_max_rate);
3079

3080
			fifo_size = (mdev->ldev->dc.c_plan_ahead * 10 * SLEEP_TIME) / HZ;
3081 3082 3083 3084
			if (fifo_size != mdev->rs_plan_s.size && fifo_size > 0) {
				rs_plan_s   = kzalloc(sizeof(int) * fifo_size, GFP_KERNEL);
				if (!rs_plan_s) {
					dev_err(DEV, "kmalloc of fifo_buffer failed");
3085
					put_ldev(mdev);
3086 3087 3088
					goto disconnect;
				}
			}
3089
			put_ldev(mdev);
3090
		}
P
Philipp Reisner 已提交
3091 3092 3093 3094

		spin_lock(&mdev->peer_seq_lock);
		/* lock against drbd_nl_syncer_conf() */
		if (verify_tfm) {
3095 3096 3097 3098
			strcpy(mdev->tconn->net_conf->verify_alg, p->verify_alg);
			mdev->tconn->net_conf->verify_alg_len = strlen(p->verify_alg) + 1;
			crypto_free_hash(mdev->tconn->verify_tfm);
			mdev->tconn->verify_tfm = verify_tfm;
P
Philipp Reisner 已提交
3099 3100 3101
			dev_info(DEV, "using verify-alg: \"%s\"\n", p->verify_alg);
		}
		if (csums_tfm) {
3102 3103 3104 3105
			strcpy(mdev->tconn->net_conf->csums_alg, p->csums_alg);
			mdev->tconn->net_conf->csums_alg_len = strlen(p->csums_alg) + 1;
			crypto_free_hash(mdev->tconn->csums_tfm);
			mdev->tconn->csums_tfm = csums_tfm;
P
Philipp Reisner 已提交
3106 3107
			dev_info(DEV, "using csums-alg: \"%s\"\n", p->csums_alg);
		}
3108 3109 3110 3111 3112 3113
		if (fifo_size != mdev->rs_plan_s.size) {
			kfree(mdev->rs_plan_s.values);
			mdev->rs_plan_s.values = rs_plan_s;
			mdev->rs_plan_s.size   = fifo_size;
			mdev->rs_planed = 0;
		}
P
Philipp Reisner 已提交
3114 3115
		spin_unlock(&mdev->peer_seq_lock);
	}
3116
	return 0;
P
Philipp Reisner 已提交
3117 3118 3119 3120 3121 3122 3123

disconnect:
	/* just for completeness: actually not needed,
	 * as this is not reached if csums_tfm was ok. */
	crypto_free_hash(csums_tfm);
	/* but free the verify_tfm again, if csums_tfm did not work out */
	crypto_free_hash(verify_tfm);
3124
	conn_request_state(mdev->tconn, NS(conn, C_DISCONNECTING), CS_HARD);
3125
	return -EIO;
P
Philipp Reisner 已提交
3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140
}

/* warn if the arguments differ by more than 12.5% */
static void warn_if_differ_considerably(struct drbd_conf *mdev,
	const char *s, sector_t a, sector_t b)
{
	sector_t d;
	if (a == 0 || b == 0)
		return;
	d = (a > b) ? (a - b) : (b - a);
	if (d > (a>>3) || d > (b>>3))
		dev_warn(DEV, "Considerable difference in %s: %llus vs. %llus\n", s,
		     (unsigned long long)a, (unsigned long long)b);
}

3141 3142
static int receive_sizes(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3143
{
3144
	struct p_sizes *p = mdev->tconn->data.rbuf;
P
Philipp Reisner 已提交
3145 3146 3147
	enum determine_dev_size dd = unchanged;
	sector_t p_size, p_usize, my_usize;
	int ldsc = 0; /* local disk size changed */
3148
	enum dds_flags ddsf;
P
Philipp Reisner 已提交
3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178

	p_size = be64_to_cpu(p->d_size);
	p_usize = be64_to_cpu(p->u_size);

	/* just store the peer's disk size for now.
	 * we still need to figure out whether we accept that. */
	mdev->p_size = p_size;

	if (get_ldev(mdev)) {
		warn_if_differ_considerably(mdev, "lower level device sizes",
			   p_size, drbd_get_max_capacity(mdev->ldev));
		warn_if_differ_considerably(mdev, "user requested size",
					    p_usize, mdev->ldev->dc.disk_size);

		/* if this is the first connect, or an otherwise expected
		 * param exchange, choose the minimum */
		if (mdev->state.conn == C_WF_REPORT_PARAMS)
			p_usize = min_not_zero((sector_t)mdev->ldev->dc.disk_size,
					     p_usize);

		my_usize = mdev->ldev->dc.disk_size;

		if (mdev->ldev->dc.disk_size != p_usize) {
			mdev->ldev->dc.disk_size = p_usize;
			dev_info(DEV, "Peer sets u_size to %lu sectors\n",
			     (unsigned long)mdev->ldev->dc.disk_size);
		}

		/* Never shrink a device with usable data during connect.
		   But allow online shrinking if we are connected. */
3179
		if (drbd_new_dev_size(mdev, mdev->ldev, 0) <
P
Philipp Reisner 已提交
3180 3181 3182 3183
		   drbd_get_capacity(mdev->this_bdev) &&
		   mdev->state.disk >= D_OUTDATED &&
		   mdev->state.conn < C_CONNECTED) {
			dev_err(DEV, "The peer's disk size is too small!\n");
3184
			conn_request_state(mdev->tconn, NS(conn, C_DISCONNECTING), CS_HARD);
P
Philipp Reisner 已提交
3185 3186
			mdev->ldev->dc.disk_size = my_usize;
			put_ldev(mdev);
3187
			return -EIO;
P
Philipp Reisner 已提交
3188 3189 3190 3191
		}
		put_ldev(mdev);
	}

3192
	ddsf = be16_to_cpu(p->dds_flags);
P
Philipp Reisner 已提交
3193
	if (get_ldev(mdev)) {
B
Bart Van Assche 已提交
3194
		dd = drbd_determine_dev_size(mdev, ddsf);
P
Philipp Reisner 已提交
3195 3196
		put_ldev(mdev);
		if (dd == dev_size_error)
3197
			return -EIO;
P
Philipp Reisner 已提交
3198 3199 3200 3201 3202 3203
		drbd_md_sync(mdev);
	} else {
		/* I am diskless, need to accept the peer's size. */
		drbd_set_my_capacity(mdev, p_size);
	}

3204 3205 3206
	mdev->peer_max_bio_size = be32_to_cpu(p->max_bio_size);
	drbd_reconsider_max_bio_size(mdev);

P
Philipp Reisner 已提交
3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220
	if (get_ldev(mdev)) {
		if (mdev->ldev->known_size != drbd_get_capacity(mdev->ldev->backing_bdev)) {
			mdev->ldev->known_size = drbd_get_capacity(mdev->ldev->backing_bdev);
			ldsc = 1;
		}

		put_ldev(mdev);
	}

	if (mdev->state.conn > C_WF_REPORT_PARAMS) {
		if (be64_to_cpu(p->c_size) !=
		    drbd_get_capacity(mdev->this_bdev) || ldsc) {
			/* we have different sizes, probably peer
			 * needs to know my new size... */
3221
			drbd_send_sizes(mdev, 0, ddsf);
P
Philipp Reisner 已提交
3222 3223 3224 3225
		}
		if (test_and_clear_bit(RESIZE_PENDING, &mdev->flags) ||
		    (dd == grew && mdev->state.conn == C_CONNECTED)) {
			if (mdev->state.pdsk >= D_INCONSISTENT &&
3226 3227 3228 3229 3230 3231
			    mdev->state.disk >= D_INCONSISTENT) {
				if (ddsf & DDSF_NO_RESYNC)
					dev_info(DEV, "Resync of new storage suppressed with --assume-clean\n");
				else
					resync_after_online_grow(mdev);
			} else
P
Philipp Reisner 已提交
3232 3233 3234 3235
				set_bit(RESYNC_AFTER_NEG, &mdev->flags);
		}
	}

3236
	return 0;
P
Philipp Reisner 已提交
3237 3238
}

3239 3240
static int receive_uuids(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3241
{
3242
	struct p_uuids *p = mdev->tconn->data.rbuf;
P
Philipp Reisner 已提交
3243
	u64 *p_uuid;
3244
	int i, updated_uuids = 0;
P
Philipp Reisner 已提交
3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259

	p_uuid = kmalloc(sizeof(u64)*UI_EXTENDED_SIZE, GFP_NOIO);

	for (i = UI_CURRENT; i < UI_EXTENDED_SIZE; i++)
		p_uuid[i] = be64_to_cpu(p->uuid[i]);

	kfree(mdev->p_uuid);
	mdev->p_uuid = p_uuid;

	if (mdev->state.conn < C_CONNECTED &&
	    mdev->state.disk < D_INCONSISTENT &&
	    mdev->state.role == R_PRIMARY &&
	    (mdev->ed_uuid & ~((u64)1)) != (p_uuid[UI_CURRENT] & ~((u64)1))) {
		dev_err(DEV, "Can only connect to data with current UUID=%016llX\n",
		    (unsigned long long)mdev->ed_uuid);
3260
		conn_request_state(mdev->tconn, NS(conn, C_DISCONNECTING), CS_HARD);
3261
		return -EIO;
P
Philipp Reisner 已提交
3262 3263 3264 3265 3266
	}

	if (get_ldev(mdev)) {
		int skip_initial_sync =
			mdev->state.conn == C_CONNECTED &&
3267
			mdev->tconn->agreed_pro_version >= 90 &&
P
Philipp Reisner 已提交
3268 3269 3270 3271 3272
			mdev->ldev->md.uuid[UI_CURRENT] == UUID_JUST_CREATED &&
			(p_uuid[UI_FLAGS] & 8);
		if (skip_initial_sync) {
			dev_info(DEV, "Accepted new current UUID, preparing to skip initial sync\n");
			drbd_bitmap_io(mdev, &drbd_bmio_clear_n_write,
3273 3274
					"clear_n_write from receive_uuids",
					BM_LOCKED_TEST_ALLOWED);
P
Philipp Reisner 已提交
3275 3276 3277 3278 3279
			_drbd_uuid_set(mdev, UI_CURRENT, p_uuid[UI_CURRENT]);
			_drbd_uuid_set(mdev, UI_BITMAP, 0);
			_drbd_set_state(_NS2(mdev, disk, D_UP_TO_DATE, pdsk, D_UP_TO_DATE),
					CS_VERBOSE, NULL);
			drbd_md_sync(mdev);
3280
			updated_uuids = 1;
P
Philipp Reisner 已提交
3281 3282
		}
		put_ldev(mdev);
3283 3284 3285 3286
	} else if (mdev->state.disk < D_INCONSISTENT &&
		   mdev->state.role == R_PRIMARY) {
		/* I am a diskless primary, the peer just created a new current UUID
		   for me. */
3287
		updated_uuids = drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
P
Philipp Reisner 已提交
3288 3289 3290 3291 3292 3293
	}

	/* Before we test for the disk state, we should wait until an eventually
	   ongoing cluster wide state change is finished. That is important if
	   we are primary and are detaching from our disk. We need to see the
	   new disk state... */
3294 3295
	mutex_lock(mdev->state_mutex);
	mutex_unlock(mdev->state_mutex);
P
Philipp Reisner 已提交
3296
	if (mdev->state.conn >= C_CONNECTED && mdev->state.disk < D_INCONSISTENT)
3297 3298 3299 3300
		updated_uuids |= drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);

	if (updated_uuids)
		drbd_print_uuids(mdev, "receiver updated UUIDs to");
P
Philipp Reisner 已提交
3301

3302
	return 0;
P
Philipp Reisner 已提交
3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334
}

/**
 * convert_state() - Converts the peer's view of the cluster state to our point of view
 * @ps:		The state as seen by the peer.
 */
static union drbd_state convert_state(union drbd_state ps)
{
	union drbd_state ms;

	static enum drbd_conns c_tab[] = {
		[C_CONNECTED] = C_CONNECTED,

		[C_STARTING_SYNC_S] = C_STARTING_SYNC_T,
		[C_STARTING_SYNC_T] = C_STARTING_SYNC_S,
		[C_DISCONNECTING] = C_TEAR_DOWN, /* C_NETWORK_FAILURE, */
		[C_VERIFY_S]       = C_VERIFY_T,
		[C_MASK]   = C_MASK,
	};

	ms.i = ps.i;

	ms.conn = c_tab[ps.conn];
	ms.peer = ps.role;
	ms.role = ps.peer;
	ms.pdsk = ps.disk;
	ms.disk = ps.pdsk;
	ms.peer_isp = (ps.aftr_isp | ps.user_isp);

	return ms;
}

3335 3336
static int receive_req_state(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
3337
{
3338
	struct p_req_state *p = mdev->tconn->data.rbuf;
P
Philipp Reisner 已提交
3339
	union drbd_state mask, val;
3340
	enum drbd_state_rv rv;
P
Philipp Reisner 已提交
3341 3342 3343 3344

	mask.i = be32_to_cpu(p->mask);
	val.i = be32_to_cpu(p->val);

3345
	if (test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags) &&
3346
	    mutex_is_locked(mdev->state_mutex)) {
P
Philipp Reisner 已提交
3347
		drbd_send_sr_reply(mdev, SS_CONCURRENT_ST_CHG);
3348
		return 0;
P
Philipp Reisner 已提交
3349 3350 3351 3352 3353
	}

	mask = convert_state(mask);
	val = convert_state(val);

3354 3355
	rv = drbd_change_state(mdev, CS_VERBOSE, mask, val);
	drbd_send_sr_reply(mdev, rv);
P
Philipp Reisner 已提交
3356 3357 3358

	drbd_md_sync(mdev);

3359
	return 0;
P
Philipp Reisner 已提交
3360 3361
}

3362 3363 3364
static int receive_req_conn_state(struct drbd_tconn *tconn, enum drbd_packet cmd,
				  unsigned int data_size)
{
3365
	struct p_req_state *p = tconn->data.rbuf;
3366 3367 3368 3369 3370 3371 3372 3373 3374
	union drbd_state mask, val;
	enum drbd_state_rv rv;

	mask.i = be32_to_cpu(p->mask);
	val.i = be32_to_cpu(p->val);

	if (test_bit(DISCARD_CONCURRENT, &tconn->flags) &&
	    mutex_is_locked(&tconn->cstate_mutex)) {
		conn_send_sr_reply(tconn, SS_CONCURRENT_ST_CHG);
3375
		return 0;
3376 3377 3378 3379 3380 3381 3382 3383
	}

	mask = convert_state(mask);
	val = convert_state(val);

	rv = conn_request_state(tconn, mask, val, CS_VERBOSE | CS_LOCAL_ONLY);
	conn_send_sr_reply(tconn, rv);

3384
	return 0;
3385 3386
}

3387 3388
static int receive_state(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3389
{
3390
	struct p_state *p = mdev->tconn->data.rbuf;
3391
	union drbd_state os, ns, peer_state;
P
Philipp Reisner 已提交
3392
	enum drbd_disk_state real_peer_disk;
3393
	enum chg_state_flags cs_flags;
P
Philipp Reisner 已提交
3394 3395 3396 3397 3398 3399 3400 3401 3402 3403
	int rv;

	peer_state.i = be32_to_cpu(p->state);

	real_peer_disk = peer_state.disk;
	if (peer_state.disk == D_NEGOTIATING) {
		real_peer_disk = mdev->p_uuid[UI_FLAGS] & 4 ? D_INCONSISTENT : D_CONSISTENT;
		dev_info(DEV, "real peer disk state = %s\n", drbd_disk_str(real_peer_disk));
	}

3404
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3405
 retry:
3406
	os = ns = mdev->state;
3407
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3408

3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429
	/* peer says his disk is uptodate, while we think it is inconsistent,
	 * and this happens while we think we have a sync going on. */
	if (os.pdsk == D_INCONSISTENT && real_peer_disk == D_UP_TO_DATE &&
	    os.conn > C_CONNECTED && os.disk == D_UP_TO_DATE) {
		/* If we are (becoming) SyncSource, but peer is still in sync
		 * preparation, ignore its uptodate-ness to avoid flapping, it
		 * will change to inconsistent once the peer reaches active
		 * syncing states.
		 * It may have changed syncer-paused flags, however, so we
		 * cannot ignore this completely. */
		if (peer_state.conn > C_CONNECTED &&
		    peer_state.conn < C_SYNC_SOURCE)
			real_peer_disk = D_INCONSISTENT;

		/* if peer_state changes to connected at the same time,
		 * it explicitly notifies us that it finished resync.
		 * Maybe we should finish it up, too? */
		else if (os.conn >= C_SYNC_SOURCE &&
			 peer_state.conn == C_CONNECTED) {
			if (drbd_bm_total_weight(mdev) <= mdev->rs_failed)
				drbd_resync_finished(mdev);
3430
			return 0;
3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442
		}
	}

	/* peer says his disk is inconsistent, while we think it is uptodate,
	 * and this happens while the peer still thinks we have a sync going on,
	 * but we think we are already done with the sync.
	 * We ignore this to avoid flapping pdsk.
	 * This should not happen, if the peer is a recent version of drbd. */
	if (os.pdsk == D_UP_TO_DATE && real_peer_disk == D_INCONSISTENT &&
	    os.conn == C_CONNECTED && peer_state.conn > C_SYNC_SOURCE)
		real_peer_disk = D_UP_TO_DATE;

3443 3444
	if (ns.conn == C_WF_REPORT_PARAMS)
		ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3445

3446 3447 3448
	if (peer_state.conn == C_AHEAD)
		ns.conn = C_BEHIND;

P
Philipp Reisner 已提交
3449 3450 3451 3452 3453
	if (mdev->p_uuid && peer_state.disk >= D_NEGOTIATING &&
	    get_ldev_if_state(mdev, D_NEGOTIATING)) {
		int cr; /* consider resync */

		/* if we established a new connection */
3454
		cr  = (os.conn < C_CONNECTED);
P
Philipp Reisner 已提交
3455 3456
		/* if we had an established connection
		 * and one of the nodes newly attaches a disk */
3457
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3458
		       (peer_state.disk == D_NEGOTIATING ||
3459
			os.disk == D_NEGOTIATING));
P
Philipp Reisner 已提交
3460 3461 3462 3463 3464
		/* if we have both been inconsistent, and the peer has been
		 * forced to be UpToDate with --overwrite-data */
		cr |= test_bit(CONSIDER_RESYNC, &mdev->flags);
		/* if we had been plain connected, and the admin requested to
		 * start a sync by "invalidate" or "invalidate-remote" */
3465
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3466 3467 3468 3469
				(peer_state.conn >= C_STARTING_SYNC_S &&
				 peer_state.conn <= C_WF_BITMAP_T));

		if (cr)
3470
			ns.conn = drbd_sync_handshake(mdev, peer_state.role, real_peer_disk);
P
Philipp Reisner 已提交
3471 3472

		put_ldev(mdev);
3473 3474
		if (ns.conn == C_MASK) {
			ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3475
			if (mdev->state.disk == D_NEGOTIATING) {
3476
				drbd_force_state(mdev, NS(disk, D_FAILED));
P
Philipp Reisner 已提交
3477 3478 3479
			} else if (peer_state.disk == D_NEGOTIATING) {
				dev_err(DEV, "Disk attach process on the peer node was aborted.\n");
				peer_state.disk = D_DISKLESS;
3480
				real_peer_disk = D_DISKLESS;
P
Philipp Reisner 已提交
3481
			} else {
3482
				if (test_and_clear_bit(CONN_DRY_RUN, &mdev->tconn->flags))
3483
					return -EIO;
3484
				D_ASSERT(os.conn == C_WF_REPORT_PARAMS);
3485
				conn_request_state(mdev->tconn, NS(conn, C_DISCONNECTING), CS_HARD);
3486
				return -EIO;
P
Philipp Reisner 已提交
3487 3488 3489 3490
			}
		}
	}

3491
	spin_lock_irq(&mdev->tconn->req_lock);
3492
	if (mdev->state.i != os.i)
P
Philipp Reisner 已提交
3493 3494 3495 3496 3497
		goto retry;
	clear_bit(CONSIDER_RESYNC, &mdev->flags);
	ns.peer = peer_state.role;
	ns.pdsk = real_peer_disk;
	ns.peer_isp = (peer_state.aftr_isp | peer_state.user_isp);
3498
	if ((ns.conn == C_CONNECTED || ns.conn == C_WF_BITMAP_S) && ns.disk == D_NEGOTIATING)
P
Philipp Reisner 已提交
3499
		ns.disk = mdev->new_state_tmp.disk;
3500 3501
	cs_flags = CS_VERBOSE + (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED ? 0 : CS_HARD);
	if (ns.pdsk == D_CONSISTENT && is_susp(ns) && ns.conn == C_CONNECTED && os.conn < C_CONNECTED &&
3502
	    test_bit(NEW_CUR_UUID, &mdev->flags)) {
3503
		/* Do not allow tl_restart(RESEND) for a rebooted peer. We can only allow this
3504
		   for temporal network outages! */
3505
		spin_unlock_irq(&mdev->tconn->req_lock);
3506
		dev_err(DEV, "Aborting Connect, can not thaw IO with an only Consistent peer\n");
3507
		tl_clear(mdev->tconn);
3508 3509
		drbd_uuid_new_current(mdev);
		clear_bit(NEW_CUR_UUID, &mdev->flags);
3510
		conn_request_state(mdev->tconn, NS2(conn, C_PROTOCOL_ERROR, susp, 0), CS_HARD);
3511
		return -EIO;
3512
	}
3513
	rv = _drbd_set_state(mdev, ns, cs_flags, NULL);
P
Philipp Reisner 已提交
3514
	ns = mdev->state;
3515
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3516 3517

	if (rv < SS_SUCCESS) {
3518
		conn_request_state(mdev->tconn, NS(conn, C_DISCONNECTING), CS_HARD);
3519
		return -EIO;
P
Philipp Reisner 已提交
3520 3521
	}

3522 3523
	if (os.conn > C_WF_REPORT_PARAMS) {
		if (ns.conn > C_CONNECTED && peer_state.conn <= C_CONNECTED &&
P
Philipp Reisner 已提交
3524 3525 3526 3527 3528 3529 3530 3531 3532
		    peer_state.disk != D_NEGOTIATING ) {
			/* we want resync, peer has not yet decided to sync... */
			/* Nowadays only used when forcing a node into primary role and
			   setting its disk to UpToDate with that */
			drbd_send_uuids(mdev);
			drbd_send_state(mdev);
		}
	}

3533
	mdev->tconn->net_conf->want_lose = 0;
P
Philipp Reisner 已提交
3534 3535 3536

	drbd_md_sync(mdev); /* update connected indicator, la_size, ... */

3537
	return 0;
P
Philipp Reisner 已提交
3538 3539
}

3540 3541
static int receive_sync_uuid(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
3542
{
3543
	struct p_rs_uuid *p = mdev->tconn->data.rbuf;
P
Philipp Reisner 已提交
3544 3545 3546

	wait_event(mdev->misc_wait,
		   mdev->state.conn == C_WF_SYNC_UUID ||
3547
		   mdev->state.conn == C_BEHIND ||
P
Philipp Reisner 已提交
3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558
		   mdev->state.conn < C_CONNECTED ||
		   mdev->state.disk < D_NEGOTIATING);

	/* D_ASSERT( mdev->state.conn == C_WF_SYNC_UUID ); */

	/* Here the _drbd_uuid_ functions are right, current should
	   _not_ be rotated into the history */
	if (get_ldev_if_state(mdev, D_NEGOTIATING)) {
		_drbd_uuid_set(mdev, UI_CURRENT, be64_to_cpu(p->uuid));
		_drbd_uuid_set(mdev, UI_BITMAP, 0UL);

3559
		drbd_print_uuids(mdev, "updated sync uuid");
P
Philipp Reisner 已提交
3560 3561 3562 3563 3564 3565
		drbd_start_resync(mdev, C_SYNC_TARGET);

		put_ldev(mdev);
	} else
		dev_err(DEV, "Ignoring SyncUUID packet!\n");

3566
	return 0;
P
Philipp Reisner 已提交
3567 3568
}

3569 3570 3571 3572 3573 3574 3575
/**
 * receive_bitmap_plain
 *
 * Return 0 when done, 1 when another iteration is needed, and a negative error
 * code upon failure.
 */
static int
3576
receive_bitmap_plain(struct drbd_conf *mdev, unsigned int data_size,
3577
		     struct p_header *h, struct bm_xfer_ctx *c)
P
Philipp Reisner 已提交
3578
{
3579
	unsigned long *buffer = (unsigned long *)h->payload;
P
Philipp Reisner 已提交
3580 3581
	unsigned num_words = min_t(size_t, BM_PACKET_WORDS, c->bm_words - c->word_offset);
	unsigned want = num_words * sizeof(long);
3582
	int err;
P
Philipp Reisner 已提交
3583

3584 3585
	if (want != data_size) {
		dev_err(DEV, "%s:want (%u) != data_size (%u)\n", __func__, want, data_size);
3586
		return -EIO;
P
Philipp Reisner 已提交
3587 3588
	}
	if (want == 0)
3589
		return 0;
3590 3591
	err = drbd_recv_all(mdev->tconn, buffer, want);
	if (err)
3592
		return err;
P
Philipp Reisner 已提交
3593 3594 3595 3596 3597 3598 3599 3600

	drbd_bm_merge_lel(mdev, c->word_offset, num_words, buffer);

	c->word_offset += num_words;
	c->bit_offset = c->word_offset * BITS_PER_LONG;
	if (c->bit_offset > c->bm_bits)
		c->bit_offset = c->bm_bits;

3601
	return 1;
P
Philipp Reisner 已提交
3602 3603
}

3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618
static enum drbd_bitmap_code dcbp_get_code(struct p_compressed_bm *p)
{
	return (enum drbd_bitmap_code)(p->encoding & 0x0f);
}

static int dcbp_get_start(struct p_compressed_bm *p)
{
	return (p->encoding & 0x80) != 0;
}

static int dcbp_get_pad_bits(struct p_compressed_bm *p)
{
	return (p->encoding >> 4) & 0x7;
}

3619 3620 3621 3622 3623 3624 3625
/**
 * recv_bm_rle_bits
 *
 * Return 0 when done, 1 when another iteration is needed, and a negative error
 * code upon failure.
 */
static int
P
Philipp Reisner 已提交
3626 3627
recv_bm_rle_bits(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
3628 3629
		 struct bm_xfer_ctx *c,
		 unsigned int len)
P
Philipp Reisner 已提交
3630 3631 3632 3633 3634 3635 3636
{
	struct bitstream bs;
	u64 look_ahead;
	u64 rl;
	u64 tmp;
	unsigned long s = c->bit_offset;
	unsigned long e;
3637
	int toggle = dcbp_get_start(p);
P
Philipp Reisner 已提交
3638 3639 3640
	int have;
	int bits;

3641
	bitstream_init(&bs, p->code, len, dcbp_get_pad_bits(p));
P
Philipp Reisner 已提交
3642 3643 3644

	bits = bitstream_get_bits(&bs, &look_ahead, 64);
	if (bits < 0)
3645
		return -EIO;
P
Philipp Reisner 已提交
3646 3647 3648 3649

	for (have = bits; have > 0; s += rl, toggle = !toggle) {
		bits = vli_decode_bits(&rl, look_ahead);
		if (bits <= 0)
3650
			return -EIO;
P
Philipp Reisner 已提交
3651 3652 3653 3654 3655

		if (toggle) {
			e = s + rl -1;
			if (e >= c->bm_bits) {
				dev_err(DEV, "bitmap overflow (e:%lu) while decoding bm RLE packet\n", e);
3656
				return -EIO;
P
Philipp Reisner 已提交
3657 3658 3659 3660 3661 3662 3663 3664 3665
			}
			_drbd_bm_set_bits(mdev, s, e);
		}

		if (have < bits) {
			dev_err(DEV, "bitmap decoding error: h:%d b:%d la:0x%08llx l:%u/%u\n",
				have, bits, look_ahead,
				(unsigned int)(bs.cur.b - p->code),
				(unsigned int)bs.buf_len);
3666
			return -EIO;
P
Philipp Reisner 已提交
3667 3668 3669 3670 3671 3672
		}
		look_ahead >>= bits;
		have -= bits;

		bits = bitstream_get_bits(&bs, &tmp, 64 - have);
		if (bits < 0)
3673
			return -EIO;
P
Philipp Reisner 已提交
3674 3675 3676 3677 3678 3679 3680
		look_ahead |= tmp << have;
		have += bits;
	}

	c->bit_offset = s;
	bm_xfer_ctx_bit_to_word_offset(c);

3681
	return (s != c->bm_bits);
P
Philipp Reisner 已提交
3682 3683
}

3684 3685 3686 3687 3688 3689 3690
/**
 * decode_bitmap_c
 *
 * Return 0 when done, 1 when another iteration is needed, and a negative error
 * code upon failure.
 */
static int
P
Philipp Reisner 已提交
3691 3692
decode_bitmap_c(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
3693 3694
		struct bm_xfer_ctx *c,
		unsigned int len)
P
Philipp Reisner 已提交
3695
{
3696
	if (dcbp_get_code(p) == RLE_VLI_Bits)
3697
		return recv_bm_rle_bits(mdev, p, c, len);
P
Philipp Reisner 已提交
3698 3699 3700 3701 3702 3703

	/* other variants had been implemented for evaluation,
	 * but have been dropped as this one turned out to be "best"
	 * during all our tests. */

	dev_err(DEV, "receive_bitmap_c: unknown encoding %u\n", p->encoding);
3704
	conn_request_state(mdev->tconn, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
3705
	return -EIO;
P
Philipp Reisner 已提交
3706 3707 3708 3709 3710 3711
}

void INFO_bm_xfer_stats(struct drbd_conf *mdev,
		const char *direction, struct bm_xfer_ctx *c)
{
	/* what would it take to transfer it "plaintext" */
3712
	unsigned plain = sizeof(struct p_header) *
P
Philipp Reisner 已提交
3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749
		((c->bm_words+BM_PACKET_WORDS-1)/BM_PACKET_WORDS+1)
		+ c->bm_words * sizeof(long);
	unsigned total = c->bytes[0] + c->bytes[1];
	unsigned r;

	/* total can not be zero. but just in case: */
	if (total == 0)
		return;

	/* don't report if not compressed */
	if (total >= plain)
		return;

	/* total < plain. check for overflow, still */
	r = (total > UINT_MAX/1000) ? (total / (plain/1000))
		                    : (1000 * total / plain);

	if (r > 1000)
		r = 1000;

	r = 1000 - r;
	dev_info(DEV, "%s bitmap stats [Bytes(packets)]: plain %u(%u), RLE %u(%u), "
	     "total %u; compression: %u.%u%%\n",
			direction,
			c->bytes[1], c->packets[1],
			c->bytes[0], c->packets[0],
			total, r/10, r % 10);
}

/* Since we are processing the bitfield from lower addresses to higher,
   it does not matter if the process it in 32 bit chunks or 64 bit
   chunks as long as it is little endian. (Understand it as byte stream,
   beginning with the lowest byte...) If we would use big endian
   we would need to process it from the highest address to the lowest,
   in order to be agnostic to the 32 vs 64 bits issue.

   returns 0 on failure, 1 if we successfully received it. */
3750 3751
static int receive_bitmap(struct drbd_conf *mdev, enum drbd_packet cmd,
			  unsigned int data_size)
P
Philipp Reisner 已提交
3752 3753
{
	struct bm_xfer_ctx c;
3754
	int err;
3755
	struct p_header *h = mdev->tconn->data.rbuf;
3756
	struct packet_info pi;
P
Philipp Reisner 已提交
3757

3758 3759 3760
	drbd_bm_lock(mdev, "receive bitmap", BM_LOCKED_SET_ALLOWED);
	/* you are supposed to send additional out-of-sync information
	 * if you actually set bits during this phase */
P
Philipp Reisner 已提交
3761 3762 3763 3764 3765 3766

	c = (struct bm_xfer_ctx) {
		.bm_bits = drbd_bm_bits(mdev),
		.bm_words = drbd_bm_words(mdev),
	};

3767
	for(;;) {
3768
		if (cmd == P_BITMAP) {
3769
			err = receive_bitmap_plain(mdev, data_size, h, &c);
3770
		} else if (cmd == P_COMPRESSED_BITMAP) {
P
Philipp Reisner 已提交
3771 3772 3773 3774
			/* MAYBE: sanity check that we speak proto >= 90,
			 * and the feature is enabled! */
			struct p_compressed_bm *p;

3775
			if (data_size > BM_PACKET_PAYLOAD_BYTES) {
P
Philipp Reisner 已提交
3776
				dev_err(DEV, "ReportCBitmap packet too large\n");
3777
				err = -EIO;
P
Philipp Reisner 已提交
3778 3779
				goto out;
			}
3780 3781

			p = mdev->tconn->data.rbuf;
3782 3783 3784
			err = drbd_recv_all(mdev->tconn, p->head.payload, data_size);
			if (err)
			       goto out;
3785 3786
			if (data_size <= (sizeof(*p) - sizeof(p->head))) {
				dev_err(DEV, "ReportCBitmap packet too small (l:%u)\n", data_size);
3787
				err = -EIO;
3788
				goto out;
P
Philipp Reisner 已提交
3789
			}
3790
			err = decode_bitmap_c(mdev, p, &c, data_size);
P
Philipp Reisner 已提交
3791
		} else {
3792
			dev_warn(DEV, "receive_bitmap: cmd neither ReportBitMap nor ReportCBitMap (is 0x%x)", cmd);
3793
			err = -EIO;
P
Philipp Reisner 已提交
3794 3795 3796
			goto out;
		}

3797
		c.packets[cmd == P_BITMAP]++;
3798
		c.bytes[cmd == P_BITMAP] += sizeof(struct p_header) + data_size;
P
Philipp Reisner 已提交
3799

3800 3801 3802
		if (err <= 0) {
			if (err < 0)
				goto out;
P
Philipp Reisner 已提交
3803
			break;
3804
		}
3805 3806
		err = drbd_recv_header(mdev->tconn, &pi);
		if (err)
P
Philipp Reisner 已提交
3807
			goto out;
3808 3809
		cmd = pi.cmd;
		data_size = pi.size;
3810
	}
P
Philipp Reisner 已提交
3811 3812 3813 3814

	INFO_bm_xfer_stats(mdev, "receive", &c);

	if (mdev->state.conn == C_WF_BITMAP_T) {
3815 3816
		enum drbd_state_rv rv;

3817 3818
		err = drbd_send_bitmap(mdev);
		if (err)
P
Philipp Reisner 已提交
3819 3820
			goto out;
		/* Omit CS_ORDERED with this state transition to avoid deadlocks. */
3821 3822
		rv = _drbd_request_state(mdev, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE);
		D_ASSERT(rv == SS_SUCCESS);
P
Philipp Reisner 已提交
3823 3824 3825 3826 3827 3828
	} else if (mdev->state.conn != C_WF_BITMAP_S) {
		/* admin may have requested C_DISCONNECTING,
		 * other threads may have noticed network errors */
		dev_info(DEV, "unexpected cstate (%s) in receive_bitmap\n",
		    drbd_conn_str(mdev->state.conn));
	}
3829
	err = 0;
P
Philipp Reisner 已提交
3830 3831

 out:
3832
	drbd_bm_unlock(mdev);
3833
	if (!err && mdev->state.conn == C_WF_BITMAP_S)
P
Philipp Reisner 已提交
3834
		drbd_start_resync(mdev, C_SYNC_SOURCE);
3835
	return err;
P
Philipp Reisner 已提交
3836 3837
}

3838
static int _tconn_receive_skip(struct drbd_tconn *tconn, unsigned int data_size)
P
Philipp Reisner 已提交
3839 3840 3841 3842 3843
{
	/* TODO zero copy sink :) */
	static char sink[128];
	int size, want, r;

3844
	size = data_size;
P
Philipp Reisner 已提交
3845 3846
	while (size > 0) {
		want = min_t(int, size, sizeof(sink));
3847 3848
		r = drbd_recv(tconn, sink, want);
		if (r <= 0)
3849
			break;
P
Philipp Reisner 已提交
3850 3851
		size -= r;
	}
3852
	return size ? -EIO : 0;
P
Philipp Reisner 已提交
3853 3854
}

3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871
static int receive_skip(struct drbd_conf *mdev, enum drbd_packet cmd,
			unsigned int data_size)
{
	dev_warn(DEV, "skipping unknown optional packet type %d, l: %d!\n",
		 cmd, data_size);

	return _tconn_receive_skip(mdev->tconn, data_size);
}

static int tconn_receive_skip(struct drbd_tconn *tconn, enum drbd_packet cmd, unsigned int data_size)
{
	conn_warn(tconn, "skipping packet for non existing volume type %d, l: %d!\n",
		  cmd, data_size);

	return _tconn_receive_skip(tconn, data_size);
}

3872 3873
static int receive_UnplugRemote(struct drbd_conf *mdev, enum drbd_packet cmd,
				unsigned int data_size)
3874
{
3875 3876
	/* Make sure we've acked all the TCP data associated
	 * with the data requests being unplugged */
3877
	drbd_tcp_quickack(mdev->tconn->data.socket);
3878

3879
	return 0;
3880 3881
}

3882 3883
static int receive_out_of_sync(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int data_size)
3884
{
3885
	struct p_block_desc *p = mdev->tconn->data.rbuf;
3886

3887 3888 3889 3890 3891 3892 3893 3894 3895 3896
	switch (mdev->state.conn) {
	case C_WF_SYNC_UUID:
	case C_WF_BITMAP_T:
	case C_BEHIND:
			break;
	default:
		dev_err(DEV, "ASSERT FAILED cstate = %s, expected: WFSyncUUID|WFBitMapT|Behind\n",
				drbd_conn_str(mdev->state.conn));
	}

3897 3898
	drbd_set_out_of_sync(mdev, be64_to_cpu(p->sector), be32_to_cpu(p->blksize));

3899
	return 0;
3900 3901
}

3902 3903 3904
struct data_cmd {
	int expect_payload;
	size_t pkt_size;
3905
	enum mdev_or_conn fa_type; /* first argument's type */
3906 3907 3908 3909 3910 3911
	union {
		int (*mdev_fn)(struct drbd_conf *, enum drbd_packet cmd,
				  unsigned int to_receive);
		int (*conn_fn)(struct drbd_tconn *, enum drbd_packet cmd,
				  unsigned int to_receive);
	};
3912 3913 3914
};

static struct data_cmd drbd_cmd_handler[] = {
3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925
	[P_DATA]	    = { 1, sizeof(struct p_data), MDEV, { receive_Data } },
	[P_DATA_REPLY]	    = { 1, sizeof(struct p_data), MDEV, { receive_DataReply } },
	[P_RS_DATA_REPLY]   = { 1, sizeof(struct p_data), MDEV, { receive_RSDataReply } } ,
	[P_BARRIER]	    = { 0, sizeof(struct p_barrier), MDEV, { receive_Barrier } } ,
	[P_BITMAP]	    = { 1, sizeof(struct p_header), MDEV, { receive_bitmap } } ,
	[P_COMPRESSED_BITMAP] = { 1, sizeof(struct p_header), MDEV, { receive_bitmap } } ,
	[P_UNPLUG_REMOTE]   = { 0, sizeof(struct p_header), MDEV, { receive_UnplugRemote } },
	[P_DATA_REQUEST]    = { 0, sizeof(struct p_block_req), MDEV, { receive_DataRequest } },
	[P_RS_DATA_REQUEST] = { 0, sizeof(struct p_block_req), MDEV, { receive_DataRequest } },
	[P_SYNC_PARAM]	    = { 1, sizeof(struct p_header), MDEV, { receive_SyncParam } },
	[P_SYNC_PARAM89]    = { 1, sizeof(struct p_header), MDEV, { receive_SyncParam } },
3926
	[P_PROTOCOL]        = { 1, sizeof(struct p_protocol), CONN, { .conn_fn = receive_protocol } },
3927 3928 3929 3930 3931 3932 3933 3934 3935 3936
	[P_UUIDS]	    = { 0, sizeof(struct p_uuids), MDEV, { receive_uuids } },
	[P_SIZES]	    = { 0, sizeof(struct p_sizes), MDEV, { receive_sizes } },
	[P_STATE]	    = { 0, sizeof(struct p_state), MDEV, { receive_state } },
	[P_STATE_CHG_REQ]   = { 0, sizeof(struct p_req_state), MDEV, { receive_req_state } },
	[P_SYNC_UUID]       = { 0, sizeof(struct p_rs_uuid), MDEV, { receive_sync_uuid } },
	[P_OV_REQUEST]      = { 0, sizeof(struct p_block_req), MDEV, { receive_DataRequest } },
	[P_OV_REPLY]        = { 1, sizeof(struct p_block_req), MDEV, { receive_DataRequest } },
	[P_CSUM_RS_REQUEST] = { 1, sizeof(struct p_block_req), MDEV, { receive_DataRequest } },
	[P_DELAY_PROBE]     = { 0, sizeof(struct p_delay_probe93), MDEV, { receive_skip } },
	[P_OUT_OF_SYNC]     = { 0, sizeof(struct p_block_desc), MDEV, { receive_out_of_sync } },
3937
	[P_CONN_ST_CHG_REQ] = { 0, sizeof(struct p_req_state), CONN, { .conn_fn = receive_req_conn_state } },
P
Philipp Reisner 已提交
3938 3939
};

3940
static void drbdd(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
3941
{
3942
	struct p_header *header = tconn->data.rbuf;
3943
	struct packet_info pi;
3944
	size_t shs; /* sub header size */
3945
	int err;
P
Philipp Reisner 已提交
3946

3947 3948
	while (get_t_state(&tconn->receiver) == RUNNING) {
		drbd_thread_current_set_cpu(&tconn->receiver);
3949
		if (drbd_recv_header(tconn, &pi))
3950
			goto err_out;
P
Philipp Reisner 已提交
3951

A
Andreas Gruenbacher 已提交
3952
		if (unlikely(pi.cmd >= ARRAY_SIZE(drbd_cmd_handler) ||
3953
		    !drbd_cmd_handler[pi.cmd].mdev_fn)) {
3954
			conn_err(tconn, "unknown packet type %d, l: %d!\n", pi.cmd, pi.size);
3955
			goto err_out;
3956
		}
P
Philipp Reisner 已提交
3957

3958 3959
		shs = drbd_cmd_handler[pi.cmd].pkt_size - sizeof(struct p_header);
		if (pi.size - shs > 0 && !drbd_cmd_handler[pi.cmd].expect_payload) {
3960
			conn_err(tconn, "No payload expected %s l:%d\n", cmdname(pi.cmd), pi.size);
3961
			goto err_out;
P
Philipp Reisner 已提交
3962 3963
		}

3964
		if (shs) {
3965 3966
			err = drbd_recv_all_warn(tconn, &header->payload, shs);
			if (err)
3967 3968 3969
				goto err_out;
		}

3970
		if (drbd_cmd_handler[pi.cmd].fa_type == CONN) {
3971
			err = drbd_cmd_handler[pi.cmd].conn_fn(tconn, pi.cmd, pi.size - shs);
3972 3973
		} else {
			struct drbd_conf *mdev = vnr_to_mdev(tconn, pi.vnr);
3974
			err = mdev ?
3975 3976 3977
				drbd_cmd_handler[pi.cmd].mdev_fn(mdev, pi.cmd, pi.size - shs) :
				tconn_receive_skip(tconn, pi.cmd, pi.size - shs);
		}
P
Philipp Reisner 已提交
3978

3979
		if (unlikely(err)) {
3980
			conn_err(tconn, "error receiving %s, l: %d!\n",
3981
			    cmdname(pi.cmd), pi.size);
3982
			goto err_out;
P
Philipp Reisner 已提交
3983 3984
		}
	}
3985
	return;
P
Philipp Reisner 已提交
3986

3987 3988
    err_out:
	conn_request_state(tconn, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
P
Philipp Reisner 已提交
3989 3990
}

3991
void conn_flush_workqueue(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
3992 3993 3994 3995
{
	struct drbd_wq_barrier barr;

	barr.w.cb = w_prev_work_done;
3996
	barr.w.tconn = tconn;
P
Philipp Reisner 已提交
3997
	init_completion(&barr.done);
3998
	drbd_queue_work(&tconn->data.work, &barr.w);
P
Philipp Reisner 已提交
3999 4000 4001
	wait_for_completion(&barr.done);
}

4002
static void drbd_disconnect(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
4003
{
4004
	enum drbd_conns oc;
P
Philipp Reisner 已提交
4005 4006
	int rv = SS_UNKNOWN_ERROR;

4007
	if (tconn->cstate == C_STANDALONE)
P
Philipp Reisner 已提交
4008 4009 4010
		return;

	/* asender does not clean up anything. it must not interfere, either */
4011 4012 4013 4014 4015 4016
	drbd_thread_stop(&tconn->asender);
	drbd_free_sock(tconn);

	idr_for_each(&tconn->volumes, drbd_disconnected, tconn);
	conn_info(tconn, "Connection closed\n");

4017 4018 4019
	if (conn_highest_role(tconn) == R_PRIMARY && conn_highest_pdsk(tconn) >= D_UNKNOWN)
		conn_try_outdate_peer_async(tconn);

4020
	spin_lock_irq(&tconn->req_lock);
4021 4022 4023 4024
	oc = tconn->cstate;
	if (oc >= C_UNCONNECTED)
		rv = _conn_request_state(tconn, NS(conn, C_UNCONNECTED), CS_VERBOSE);

4025 4026
	spin_unlock_irq(&tconn->req_lock);

4027
	if (oc == C_DISCONNECTING) {
4028 4029 4030 4031 4032 4033 4034
		wait_event(tconn->net_cnt_wait, atomic_read(&tconn->net_cnt) == 0);

		crypto_free_hash(tconn->cram_hmac_tfm);
		tconn->cram_hmac_tfm = NULL;

		kfree(tconn->net_conf);
		tconn->net_conf = NULL;
4035
		conn_request_state(tconn, NS(conn, C_STANDALONE), CS_VERBOSE);
4036 4037 4038 4039 4040 4041 4042 4043
	}
}

static int drbd_disconnected(int vnr, void *p, void *data)
{
	struct drbd_conf *mdev = (struct drbd_conf *)p;
	enum drbd_fencing_p fp;
	unsigned int i;
P
Philipp Reisner 已提交
4044

4045
	/* wait for current activity to cease. */
4046
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
4047 4048 4049
	_drbd_wait_ee_list_empty(mdev, &mdev->active_ee);
	_drbd_wait_ee_list_empty(mdev, &mdev->sync_ee);
	_drbd_wait_ee_list_empty(mdev, &mdev->read_ee);
4050
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067

	/* We do not have data structures that would allow us to
	 * get the rs_pending_cnt down to 0 again.
	 *  * On C_SYNC_TARGET we do not have any data structures describing
	 *    the pending RSDataRequest's we have sent.
	 *  * On C_SYNC_SOURCE there is no data structure that tracks
	 *    the P_RS_DATA_REPLY blocks that we sent to the SyncTarget.
	 *  And no, it is not the sum of the reference counts in the
	 *  resync_LRU. The resync_LRU tracks the whole operation including
	 *  the disk-IO, while the rs_pending_cnt only tracks the blocks
	 *  on the fly. */
	drbd_rs_cancel_all(mdev);
	mdev->rs_total = 0;
	mdev->rs_failed = 0;
	atomic_set(&mdev->rs_pending_cnt, 0);
	wake_up(&mdev->misc_wait);

4068 4069
	del_timer(&mdev->request_timer);

P
Philipp Reisner 已提交
4070 4071 4072 4073 4074 4075
	del_timer_sync(&mdev->resync_timer);
	resync_timer_fn((unsigned long)mdev);

	/* wait for all w_e_end_data_req, w_e_end_rsdata_req, w_send_barrier,
	 * w_make_resync_request etc. which may still be on the worker queue
	 * to be "canceled" */
4076
	drbd_flush_workqueue(mdev);
P
Philipp Reisner 已提交
4077 4078 4079 4080 4081 4082 4083 4084

	/* This also does reclaim_net_ee().  If we do this too early, we might
	 * miss some resync ee and pages.*/
	drbd_process_done_ee(mdev);

	kfree(mdev->p_uuid);
	mdev->p_uuid = NULL;

4085
	if (!is_susp(mdev->state))
4086
		tl_clear(mdev->tconn);
P
Philipp Reisner 已提交
4087 4088 4089 4090 4091 4092 4093 4094 4095

	drbd_md_sync(mdev);

	fp = FP_DONT_CARE;
	if (get_ldev(mdev)) {
		fp = mdev->ldev->dc.fencing;
		put_ldev(mdev);
	}

4096 4097 4098 4099
	/* serialize with bitmap writeout triggered by the state change,
	 * if any. */
	wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));

P
Philipp Reisner 已提交
4100 4101 4102 4103 4104 4105 4106 4107 4108 4109
	/* tcp_close and release of sendpage pages can be deferred.  I don't
	 * want to use SO_LINGER, because apparently it can be deferred for
	 * more than 20 seconds (longest time I checked).
	 *
	 * Actually we don't care for exactly when the network stack does its
	 * put_page(), but release our reference on these pages right here.
	 */
	i = drbd_release_ee(mdev, &mdev->net_ee);
	if (i)
		dev_info(DEV, "net_ee not empty, killed %u entries\n", i);
4110 4111 4112
	i = atomic_read(&mdev->pp_in_use_by_net);
	if (i)
		dev_info(DEV, "pp_in_use_by_net = %d, expected 0\n", i);
P
Philipp Reisner 已提交
4113 4114
	i = atomic_read(&mdev->pp_in_use);
	if (i)
4115
		dev_info(DEV, "pp_in_use = %d, expected 0\n", i);
P
Philipp Reisner 已提交
4116 4117 4118 4119 4120 4121 4122 4123 4124

	D_ASSERT(list_empty(&mdev->read_ee));
	D_ASSERT(list_empty(&mdev->active_ee));
	D_ASSERT(list_empty(&mdev->sync_ee));
	D_ASSERT(list_empty(&mdev->done_ee));

	/* ok, no more ee's on the fly, it is safe to reset the epoch_size */
	atomic_set(&mdev->current_epoch->epoch_size, 0);
	D_ASSERT(list_empty(&mdev->current_epoch->list));
4125 4126

	return 0;
P
Philipp Reisner 已提交
4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137
}

/*
 * We support PRO_VERSION_MIN to PRO_VERSION_MAX. The protocol version
 * we can agree on is stored in agreed_pro_version.
 *
 * feature flags and the reserved array should be enough room for future
 * enhancements of the handshake protocol, and possible plugins...
 *
 * for now, they are expected to be zero, but ignored.
 */
4138
static int drbd_send_handshake(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
4139
{
4140
	/* ASSERT current == mdev->tconn->receiver ... */
4141
	struct p_handshake *p = &tconn->data.sbuf.handshake;
4142
	int err;
P
Philipp Reisner 已提交
4143

4144 4145
	if (mutex_lock_interruptible(&tconn->data.mutex)) {
		conn_err(tconn, "interrupted during initial handshake\n");
4146
		return -EINTR;
P
Philipp Reisner 已提交
4147 4148
	}

4149 4150
	if (tconn->data.socket == NULL) {
		mutex_unlock(&tconn->data.mutex);
4151
		return -EIO;
P
Philipp Reisner 已提交
4152 4153 4154 4155 4156
	}

	memset(p, 0, sizeof(*p));
	p->protocol_min = cpu_to_be32(PRO_VERSION_MIN);
	p->protocol_max = cpu_to_be32(PRO_VERSION_MAX);
4157
	err = _conn_send_cmd(tconn, 0, tconn->data.socket, P_HAND_SHAKE,
4158
			     &p->head, sizeof(*p), 0);
4159
	mutex_unlock(&tconn->data.mutex);
4160
	return err;
P
Philipp Reisner 已提交
4161 4162 4163 4164 4165 4166 4167 4168 4169
}

/*
 * return values:
 *   1 yes, we have a valid connection
 *   0 oops, did not work out, please try again
 *  -1 peer talks different language,
 *     no point in trying again, please go standalone.
 */
4170
static int drbd_do_handshake(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
4171
{
4172
	/* ASSERT current == tconn->receiver ... */
4173
	struct p_handshake *p = tconn->data.rbuf;
4174
	const int expect = sizeof(struct p_handshake) - sizeof(struct p_header80);
4175
	struct packet_info pi;
4176
	int err;
P
Philipp Reisner 已提交
4177

4178 4179
	err = drbd_send_handshake(tconn);
	if (err)
P
Philipp Reisner 已提交
4180 4181
		return 0;

4182 4183
	err = drbd_recv_header(tconn, &pi);
	if (err)
P
Philipp Reisner 已提交
4184 4185
		return 0;

4186
	if (pi.cmd != P_HAND_SHAKE) {
4187
		conn_err(tconn, "expected HandShake packet, received: %s (0x%04x)\n",
4188
		     cmdname(pi.cmd), pi.cmd);
P
Philipp Reisner 已提交
4189 4190 4191
		return -1;
	}

4192
	if (pi.size != expect) {
4193
		conn_err(tconn, "expected HandShake length: %u, received: %u\n",
4194
		     expect, pi.size);
P
Philipp Reisner 已提交
4195 4196 4197
		return -1;
	}

4198 4199
	err = drbd_recv_all_warn(tconn, &p->head.payload, expect);
	if (err)
P
Philipp Reisner 已提交
4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210
		return 0;

	p->protocol_min = be32_to_cpu(p->protocol_min);
	p->protocol_max = be32_to_cpu(p->protocol_max);
	if (p->protocol_max == 0)
		p->protocol_max = p->protocol_min;

	if (PRO_VERSION_MAX < p->protocol_min ||
	    PRO_VERSION_MIN > p->protocol_max)
		goto incompat;

4211
	tconn->agreed_pro_version = min_t(int, PRO_VERSION_MAX, p->protocol_max);
P
Philipp Reisner 已提交
4212

4213 4214
	conn_info(tconn, "Handshake successful: "
	     "Agreed network protocol version %d\n", tconn->agreed_pro_version);
P
Philipp Reisner 已提交
4215 4216 4217 4218

	return 1;

 incompat:
4219
	conn_err(tconn, "incompatible DRBD dialects: "
P
Philipp Reisner 已提交
4220 4221 4222 4223 4224 4225 4226
	    "I support %d-%d, peer supports %d-%d\n",
	    PRO_VERSION_MIN, PRO_VERSION_MAX,
	    p->protocol_min, p->protocol_max);
	return -1;
}

#if !defined(CONFIG_CRYPTO_HMAC) && !defined(CONFIG_CRYPTO_HMAC_MODULE)
4227
static int drbd_do_auth(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
4228 4229 4230
{
	dev_err(DEV, "This kernel was build without CONFIG_CRYPTO_HMAC.\n");
	dev_err(DEV, "You need to disable 'cram-hmac-alg' in drbd.conf.\n");
4231
	return -1;
P
Philipp Reisner 已提交
4232 4233 4234
}
#else
#define CHALLENGE_LEN 64
4235 4236 4237 4238 4239 4240 4241

/* Return value:
	1 - auth succeeded,
	0 - failed, try again (network error),
	-1 - auth failed, don't try again.
*/

4242
static int drbd_do_auth(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
4243 4244 4245 4246 4247 4248
{
	char my_challenge[CHALLENGE_LEN];  /* 64 Bytes... */
	struct scatterlist sg;
	char *response = NULL;
	char *right_response = NULL;
	char *peers_ch = NULL;
4249
	unsigned int key_len = strlen(tconn->net_conf->shared_secret);
P
Philipp Reisner 已提交
4250 4251
	unsigned int resp_size;
	struct hash_desc desc;
4252
	struct packet_info pi;
4253
	int err, rv;
P
Philipp Reisner 已提交
4254

4255
	desc.tfm = tconn->cram_hmac_tfm;
P
Philipp Reisner 已提交
4256 4257
	desc.flags = 0;

4258 4259
	rv = crypto_hash_setkey(tconn->cram_hmac_tfm,
				(u8 *)tconn->net_conf->shared_secret, key_len);
P
Philipp Reisner 已提交
4260
	if (rv) {
4261
		conn_err(tconn, "crypto_hash_setkey() failed with %d\n", rv);
4262
		rv = -1;
P
Philipp Reisner 已提交
4263 4264 4265 4266 4267
		goto fail;
	}

	get_random_bytes(my_challenge, CHALLENGE_LEN);

4268
	rv = !conn_send_cmd2(tconn, P_AUTH_CHALLENGE, my_challenge, CHALLENGE_LEN);
P
Philipp Reisner 已提交
4269 4270 4271
	if (!rv)
		goto fail;

4272 4273 4274
	err = drbd_recv_header(tconn, &pi);
	if (err) {
		rv = 0;
P
Philipp Reisner 已提交
4275
		goto fail;
4276
	}
P
Philipp Reisner 已提交
4277

4278
	if (pi.cmd != P_AUTH_CHALLENGE) {
4279
		conn_err(tconn, "expected AuthChallenge packet, received: %s (0x%04x)\n",
4280
		    cmdname(pi.cmd), pi.cmd);
P
Philipp Reisner 已提交
4281 4282 4283 4284
		rv = 0;
		goto fail;
	}

4285
	if (pi.size > CHALLENGE_LEN * 2) {
4286
		conn_err(tconn, "expected AuthChallenge payload too big.\n");
4287
		rv = -1;
P
Philipp Reisner 已提交
4288 4289 4290
		goto fail;
	}

4291
	peers_ch = kmalloc(pi.size, GFP_NOIO);
P
Philipp Reisner 已提交
4292
	if (peers_ch == NULL) {
4293
		conn_err(tconn, "kmalloc of peers_ch failed\n");
4294
		rv = -1;
P
Philipp Reisner 已提交
4295 4296 4297
		goto fail;
	}

4298 4299
	err = drbd_recv_all_warn(tconn, peers_ch, pi.size);
	if (err) {
P
Philipp Reisner 已提交
4300 4301 4302 4303
		rv = 0;
		goto fail;
	}

4304
	resp_size = crypto_hash_digestsize(tconn->cram_hmac_tfm);
P
Philipp Reisner 已提交
4305 4306
	response = kmalloc(resp_size, GFP_NOIO);
	if (response == NULL) {
4307
		conn_err(tconn, "kmalloc of response failed\n");
4308
		rv = -1;
P
Philipp Reisner 已提交
4309 4310 4311 4312
		goto fail;
	}

	sg_init_table(&sg, 1);
4313
	sg_set_buf(&sg, peers_ch, pi.size);
P
Philipp Reisner 已提交
4314 4315 4316

	rv = crypto_hash_digest(&desc, &sg, sg.length, response);
	if (rv) {
4317
		conn_err(tconn, "crypto_hash_digest() failed with %d\n", rv);
4318
		rv = -1;
P
Philipp Reisner 已提交
4319 4320 4321
		goto fail;
	}

4322
	rv = !conn_send_cmd2(tconn, P_AUTH_RESPONSE, response, resp_size);
P
Philipp Reisner 已提交
4323 4324 4325
	if (!rv)
		goto fail;

4326 4327 4328
	err = drbd_recv_header(tconn, &pi);
	if (err) {
		rv = 0;
P
Philipp Reisner 已提交
4329
		goto fail;
4330
	}
P
Philipp Reisner 已提交
4331

4332
	if (pi.cmd != P_AUTH_RESPONSE) {
4333
		conn_err(tconn, "expected AuthResponse packet, received: %s (0x%04x)\n",
4334
			cmdname(pi.cmd), pi.cmd);
P
Philipp Reisner 已提交
4335 4336 4337 4338
		rv = 0;
		goto fail;
	}

4339
	if (pi.size != resp_size) {
4340
		conn_err(tconn, "expected AuthResponse payload of wrong size\n");
P
Philipp Reisner 已提交
4341 4342 4343 4344
		rv = 0;
		goto fail;
	}

4345 4346
	err = drbd_recv_all_warn(tconn, response , resp_size);
	if (err) {
P
Philipp Reisner 已提交
4347 4348 4349 4350 4351
		rv = 0;
		goto fail;
	}

	right_response = kmalloc(resp_size, GFP_NOIO);
4352
	if (right_response == NULL) {
4353
		conn_err(tconn, "kmalloc of right_response failed\n");
4354
		rv = -1;
P
Philipp Reisner 已提交
4355 4356 4357 4358 4359 4360 4361
		goto fail;
	}

	sg_set_buf(&sg, my_challenge, CHALLENGE_LEN);

	rv = crypto_hash_digest(&desc, &sg, sg.length, right_response);
	if (rv) {
4362
		conn_err(tconn, "crypto_hash_digest() failed with %d\n", rv);
4363
		rv = -1;
P
Philipp Reisner 已提交
4364 4365 4366 4367 4368 4369
		goto fail;
	}

	rv = !memcmp(response, right_response, resp_size);

	if (rv)
4370 4371
		conn_info(tconn, "Peer authenticated using %d bytes of '%s' HMAC\n",
		     resp_size, tconn->net_conf->cram_hmac_alg);
4372 4373
	else
		rv = -1;
P
Philipp Reisner 已提交
4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385

 fail:
	kfree(peers_ch);
	kfree(response);
	kfree(right_response);

	return rv;
}
#endif

int drbdd_init(struct drbd_thread *thi)
{
4386
	struct drbd_tconn *tconn = thi->tconn;
P
Philipp Reisner 已提交
4387 4388
	int h;

4389
	conn_info(tconn, "receiver (re)started\n");
P
Philipp Reisner 已提交
4390 4391

	do {
4392
		h = drbd_connect(tconn);
P
Philipp Reisner 已提交
4393
		if (h == 0) {
4394
			drbd_disconnect(tconn);
4395
			schedule_timeout_interruptible(HZ);
P
Philipp Reisner 已提交
4396 4397
		}
		if (h == -1) {
4398
			conn_warn(tconn, "Discarding network configuration.\n");
4399
			conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
P
Philipp Reisner 已提交
4400 4401 4402 4403
		}
	} while (h == 0);

	if (h > 0) {
4404 4405 4406
		if (get_net_conf(tconn)) {
			drbdd(tconn);
			put_net_conf(tconn);
P
Philipp Reisner 已提交
4407 4408 4409
		}
	}

4410
	drbd_disconnect(tconn);
P
Philipp Reisner 已提交
4411

4412
	conn_info(tconn, "receiver terminated\n");
P
Philipp Reisner 已提交
4413 4414 4415 4416 4417
	return 0;
}

/* ********* acknowledge sender ******** */

4418 4419
static int got_conn_RqSReply(struct drbd_tconn *tconn, enum drbd_packet cmd)
{
4420
	struct p_req_state_reply *p = tconn->meta.rbuf;
4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434
	int retcode = be32_to_cpu(p->retcode);

	if (retcode >= SS_SUCCESS) {
		set_bit(CONN_WD_ST_CHG_OKAY, &tconn->flags);
	} else {
		set_bit(CONN_WD_ST_CHG_FAIL, &tconn->flags);
		conn_err(tconn, "Requested state change failed by peer: %s (%d)\n",
			 drbd_set_st_err_str(retcode), retcode);
	}
	wake_up(&tconn->ping_wait);

	return true;
}

4435
static int got_RqSReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4436
{
4437
	struct p_req_state_reply *p = mdev->tconn->meta.rbuf;
P
Philipp Reisner 已提交
4438 4439
	int retcode = be32_to_cpu(p->retcode);

4440 4441 4442 4443 4444 4445
	if (retcode >= SS_SUCCESS) {
		set_bit(CL_ST_CHG_SUCCESS, &mdev->flags);
	} else {
		set_bit(CL_ST_CHG_FAIL, &mdev->flags);
		dev_err(DEV, "Requested state change failed by peer: %s (%d)\n",
			drbd_set_st_err_str(retcode), retcode);
P
Philipp Reisner 已提交
4446
	}
4447 4448
	wake_up(&mdev->state_wait);

4449
	return true;
P
Philipp Reisner 已提交
4450 4451
}

4452
static int got_Ping(struct drbd_tconn *tconn, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4453
{
4454
	return drbd_send_ping_ack(tconn);
P
Philipp Reisner 已提交
4455 4456 4457

}

4458
static int got_PingAck(struct drbd_tconn *tconn, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4459 4460
{
	/* restore idle timeout */
4461 4462 4463
	tconn->meta.socket->sk->sk_rcvtimeo = tconn->net_conf->ping_int*HZ;
	if (!test_and_set_bit(GOT_PING_ACK, &tconn->flags))
		wake_up(&tconn->ping_wait);
P
Philipp Reisner 已提交
4464

4465
	return true;
P
Philipp Reisner 已提交
4466 4467
}

4468
static int got_IsInSync(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4469
{
4470
	struct p_block_ack *p = mdev->tconn->meta.rbuf;
P
Philipp Reisner 已提交
4471 4472 4473
	sector_t sector = be64_to_cpu(p->sector);
	int blksize = be32_to_cpu(p->blksize);

4474
	D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
P
Philipp Reisner 已提交
4475 4476 4477

	update_peer_seq(mdev, be32_to_cpu(p->seq_num));

4478 4479 4480 4481 4482 4483 4484
	if (get_ldev(mdev)) {
		drbd_rs_complete_io(mdev, sector);
		drbd_set_in_sync(mdev, sector, blksize);
		/* rs_same_csums is supposed to count in units of BM_BLOCK_SIZE */
		mdev->rs_same_csum += (blksize >> BM_BLOCK_SHIFT);
		put_ldev(mdev);
	}
P
Philipp Reisner 已提交
4485
	dec_rs_pending(mdev);
4486
	atomic_add(blksize >> 9, &mdev->rs_sect_in);
P
Philipp Reisner 已提交
4487

4488
	return true;
P
Philipp Reisner 已提交
4489 4490
}

4491 4492 4493 4494
static int
validate_req_change_req_state(struct drbd_conf *mdev, u64 id, sector_t sector,
			      struct rb_root *root, const char *func,
			      enum drbd_req_event what, bool missing_ok)
P
Philipp Reisner 已提交
4495 4496 4497 4498
{
	struct drbd_request *req;
	struct bio_and_error m;

4499
	spin_lock_irq(&mdev->tconn->req_lock);
4500
	req = find_request(mdev, root, id, sector, missing_ok, func);
P
Philipp Reisner 已提交
4501
	if (unlikely(!req)) {
4502
		spin_unlock_irq(&mdev->tconn->req_lock);
4503
		return false;
P
Philipp Reisner 已提交
4504 4505
	}
	__req_mod(req, what, &m);
4506
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
4507 4508 4509

	if (m.bio)
		complete_master_bio(mdev, &m);
4510
	return true;
P
Philipp Reisner 已提交
4511 4512
}

4513
static int got_BlockAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4514
{
4515
	struct p_block_ack *p = mdev->tconn->meta.rbuf;
P
Philipp Reisner 已提交
4516 4517 4518 4519 4520 4521
	sector_t sector = be64_to_cpu(p->sector);
	int blksize = be32_to_cpu(p->blksize);
	enum drbd_req_event what;

	update_peer_seq(mdev, be32_to_cpu(p->seq_num));

4522
	if (p->block_id == ID_SYNCER) {
P
Philipp Reisner 已提交
4523 4524
		drbd_set_in_sync(mdev, sector, blksize);
		dec_rs_pending(mdev);
4525
		return true;
P
Philipp Reisner 已提交
4526
	}
4527
	switch (cmd) {
P
Philipp Reisner 已提交
4528
	case P_RS_WRITE_ACK:
4529
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4530
		what = WRITE_ACKED_BY_PEER_AND_SIS;
P
Philipp Reisner 已提交
4531 4532
		break;
	case P_WRITE_ACK:
4533
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4534
		what = WRITE_ACKED_BY_PEER;
P
Philipp Reisner 已提交
4535 4536
		break;
	case P_RECV_ACK:
4537
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_B);
4538
		what = RECV_ACKED_BY_PEER;
P
Philipp Reisner 已提交
4539
		break;
4540
	case P_DISCARD_WRITE:
4541
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4542 4543 4544 4545 4546
		what = DISCARD_WRITE;
		break;
	case P_RETRY_WRITE:
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
		what = POSTPONE_WRITE;
P
Philipp Reisner 已提交
4547 4548 4549
		break;
	default:
		D_ASSERT(0);
4550
		return false;
P
Philipp Reisner 已提交
4551 4552 4553
	}

	return validate_req_change_req_state(mdev, p->block_id, sector,
4554 4555
					     &mdev->write_requests, __func__,
					     what, false);
P
Philipp Reisner 已提交
4556 4557
}

4558
static int got_NegAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4559
{
4560
	struct p_block_ack *p = mdev->tconn->meta.rbuf;
P
Philipp Reisner 已提交
4561
	sector_t sector = be64_to_cpu(p->sector);
4562
	int size = be32_to_cpu(p->blksize);
4563 4564
	bool missing_ok = mdev->tconn->net_conf->wire_protocol == DRBD_PROT_A ||
			  mdev->tconn->net_conf->wire_protocol == DRBD_PROT_B;
4565
	bool found;
P
Philipp Reisner 已提交
4566 4567 4568

	update_peer_seq(mdev, be32_to_cpu(p->seq_num));

4569
	if (p->block_id == ID_SYNCER) {
P
Philipp Reisner 已提交
4570 4571
		dec_rs_pending(mdev);
		drbd_rs_failed_io(mdev, sector, size);
4572
		return true;
P
Philipp Reisner 已提交
4573
	}
4574

4575
	found = validate_req_change_req_state(mdev, p->block_id, sector,
4576
					      &mdev->write_requests, __func__,
4577
					      NEG_ACKED, missing_ok);
4578 4579 4580 4581 4582 4583 4584
	if (!found) {
		/* Protocol A has no P_WRITE_ACKs, but has P_NEG_ACKs.
		   The master bio might already be completed, therefore the
		   request is no longer in the collision hash. */
		/* In Protocol B we might already have got a P_RECV_ACK
		   but then get a P_NEG_ACK afterwards. */
		if (!missing_ok)
4585
			return false;
4586
		drbd_set_out_of_sync(mdev, sector, size);
4587 4588
	}
	return true;
P
Philipp Reisner 已提交
4589 4590
}

4591
static int got_NegDReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4592
{
4593
	struct p_block_ack *p = mdev->tconn->meta.rbuf;
P
Philipp Reisner 已提交
4594 4595 4596
	sector_t sector = be64_to_cpu(p->sector);

	update_peer_seq(mdev, be32_to_cpu(p->seq_num));
4597

P
Philipp Reisner 已提交
4598 4599 4600 4601
	dev_err(DEV, "Got NegDReply; Sector %llus, len %u; Fail original request.\n",
	    (unsigned long long)sector, be32_to_cpu(p->blksize));

	return validate_req_change_req_state(mdev, p->block_id, sector,
4602
					     &mdev->read_requests, __func__,
4603
					     NEG_ACKED, false);
P
Philipp Reisner 已提交
4604 4605
}

4606
static int got_NegRSDReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4607 4608 4609
{
	sector_t sector;
	int size;
4610
	struct p_block_ack *p = mdev->tconn->meta.rbuf;
P
Philipp Reisner 已提交
4611 4612 4613 4614 4615 4616 4617 4618 4619 4620

	sector = be64_to_cpu(p->sector);
	size = be32_to_cpu(p->blksize);

	update_peer_seq(mdev, be32_to_cpu(p->seq_num));

	dec_rs_pending(mdev);

	if (get_ldev_if_state(mdev, D_FAILED)) {
		drbd_rs_complete_io(mdev, sector);
4621
		switch (cmd) {
4622 4623 4624 4625 4626 4627 4628 4629 4630
		case P_NEG_RS_DREPLY:
			drbd_rs_failed_io(mdev, sector, size);
		case P_RS_CANCEL:
			break;
		default:
			D_ASSERT(0);
			put_ldev(mdev);
			return false;
		}
P
Philipp Reisner 已提交
4631 4632 4633
		put_ldev(mdev);
	}

4634
	return true;
P
Philipp Reisner 已提交
4635 4636
}

4637
static int got_BarrierAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4638
{
4639
	struct p_barrier_ack *p = mdev->tconn->meta.rbuf;
P
Philipp Reisner 已提交
4640

4641
	tl_release(mdev->tconn, p->barrier, be32_to_cpu(p->set_size));
P
Philipp Reisner 已提交
4642

4643 4644
	if (mdev->state.conn == C_AHEAD &&
	    atomic_read(&mdev->ap_in_flight) == 0 &&
4645 4646 4647
	    !test_and_set_bit(AHEAD_TO_SYNC_SOURCE, &mdev->current_epoch->flags)) {
		mdev->start_resync_timer.expires = jiffies + HZ;
		add_timer(&mdev->start_resync_timer);
4648 4649
	}

4650
	return true;
P
Philipp Reisner 已提交
4651 4652
}

4653
static int got_OVResult(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4654
{
4655
	struct p_block_ack *p = mdev->tconn->meta.rbuf;
P
Philipp Reisner 已提交
4656 4657 4658 4659 4660 4661 4662 4663 4664 4665
	struct drbd_work *w;
	sector_t sector;
	int size;

	sector = be64_to_cpu(p->sector);
	size = be32_to_cpu(p->blksize);

	update_peer_seq(mdev, be32_to_cpu(p->seq_num));

	if (be64_to_cpu(p->block_id) == ID_OUT_OF_SYNC)
4666
		drbd_ov_out_of_sync_found(mdev, sector, size);
P
Philipp Reisner 已提交
4667
	else
4668
		ov_out_of_sync_print(mdev);
P
Philipp Reisner 已提交
4669

4670
	if (!get_ldev(mdev))
4671
		return true;
4672

P
Philipp Reisner 已提交
4673 4674 4675
	drbd_rs_complete_io(mdev, sector);
	dec_rs_pending(mdev);

4676 4677 4678 4679 4680 4681 4682
	--mdev->ov_left;

	/* let's advance progress step marks only for every other megabyte */
	if ((mdev->ov_left & 0x200) == 0x200)
		drbd_advance_rs_marks(mdev, mdev->ov_left);

	if (mdev->ov_left == 0) {
P
Philipp Reisner 已提交
4683 4684 4685
		w = kmalloc(sizeof(*w), GFP_NOIO);
		if (w) {
			w->cb = w_ov_finished;
4686
			w->mdev = mdev;
4687
			drbd_queue_work_front(&mdev->tconn->data.work, w);
P
Philipp Reisner 已提交
4688 4689
		} else {
			dev_err(DEV, "kmalloc(w) failed.");
4690
			ov_out_of_sync_print(mdev);
P
Philipp Reisner 已提交
4691 4692 4693
			drbd_resync_finished(mdev);
		}
	}
4694
	put_ldev(mdev);
4695
	return true;
P
Philipp Reisner 已提交
4696 4697
}

4698
static int got_skip(struct drbd_conf *mdev, enum drbd_packet cmd)
4699
{
4700
	return true;
4701 4702
}

4703 4704
static int tconn_process_done_ee(struct drbd_tconn *tconn)
{
4705 4706
	struct drbd_conf *mdev;
	int i, not_empty = 0;
4707 4708 4709 4710

	do {
		clear_bit(SIGNAL_ASENDER, &tconn->flags);
		flush_signals(current);
4711
		idr_for_each_entry(&tconn->volumes, mdev, i) {
4712
			if (drbd_process_done_ee(mdev))
4713 4714
				return 1; /* error */
		}
4715
		set_bit(SIGNAL_ASENDER, &tconn->flags);
4716 4717 4718 4719 4720 4721 4722 4723

		spin_lock_irq(&tconn->req_lock);
		idr_for_each_entry(&tconn->volumes, mdev, i) {
			not_empty = !list_empty(&mdev->done_ee);
			if (not_empty)
				break;
		}
		spin_unlock_irq(&tconn->req_lock);
4724 4725 4726 4727 4728
	} while (not_empty);

	return 0;
}

4729 4730
struct asender_cmd {
	size_t pkt_size;
4731 4732 4733 4734 4735
	enum mdev_or_conn fa_type; /* first argument's type */
	union {
		int (*mdev_fn)(struct drbd_conf *mdev, enum drbd_packet cmd);
		int (*conn_fn)(struct drbd_tconn *tconn, enum drbd_packet cmd);
	};
4736 4737 4738
};

static struct asender_cmd asender_tbl[] = {
4739 4740
	[P_PING]	    = { sizeof(struct p_header), CONN, { .conn_fn = got_Ping } },
	[P_PING_ACK]	    = { sizeof(struct p_header), CONN, { .conn_fn = got_PingAck } },
4741 4742 4743 4744 4745 4746 4747 4748 4749 4750 4751 4752 4753
	[P_RECV_ACK]	    = { sizeof(struct p_block_ack), MDEV, { got_BlockAck } },
	[P_WRITE_ACK]	    = { sizeof(struct p_block_ack), MDEV, { got_BlockAck } },
	[P_RS_WRITE_ACK]    = { sizeof(struct p_block_ack), MDEV, { got_BlockAck } },
	[P_DISCARD_WRITE]   = { sizeof(struct p_block_ack), MDEV, { got_BlockAck } },
	[P_NEG_ACK]	    = { sizeof(struct p_block_ack), MDEV, { got_NegAck } },
	[P_NEG_DREPLY]	    = { sizeof(struct p_block_ack), MDEV, { got_NegDReply } },
	[P_NEG_RS_DREPLY]   = { sizeof(struct p_block_ack), MDEV, { got_NegRSDReply } },
	[P_OV_RESULT]	    = { sizeof(struct p_block_ack), MDEV, { got_OVResult } },
	[P_BARRIER_ACK]	    = { sizeof(struct p_barrier_ack), MDEV, { got_BarrierAck } },
	[P_STATE_CHG_REPLY] = { sizeof(struct p_req_state_reply), MDEV, { got_RqSReply } },
	[P_RS_IS_IN_SYNC]   = { sizeof(struct p_block_ack), MDEV, { got_IsInSync } },
	[P_DELAY_PROBE]     = { sizeof(struct p_delay_probe93), MDEV, { got_skip } },
	[P_RS_CANCEL]       = { sizeof(struct p_block_ack), MDEV, { got_NegRSDReply } },
4754
	[P_CONN_ST_CHG_REPLY]={ sizeof(struct p_req_state_reply), CONN, {.conn_fn = got_conn_RqSReply}},
4755
	[P_RETRY_WRITE]	    = { sizeof(struct p_block_ack), MDEV, { got_BlockAck } },
4756 4757
};

P
Philipp Reisner 已提交
4758 4759
int drbd_asender(struct drbd_thread *thi)
{
4760
	struct drbd_tconn *tconn = thi->tconn;
4761
	struct p_header *h = tconn->meta.rbuf;
P
Philipp Reisner 已提交
4762
	struct asender_cmd *cmd = NULL;
4763
	struct packet_info pi;
4764
	int rv;
P
Philipp Reisner 已提交
4765 4766
	void *buf    = h;
	int received = 0;
4767
	int expect   = sizeof(struct p_header);
4768
	int ping_timeout_active = 0;
P
Philipp Reisner 已提交
4769 4770 4771 4772

	current->policy = SCHED_RR;  /* Make this a realtime task! */
	current->rt_priority = 2;    /* more important than all other tasks */

4773
	while (get_t_state(thi) == RUNNING) {
4774
		drbd_thread_current_set_cpu(thi);
4775
		if (test_and_clear_bit(SEND_PING, &tconn->flags)) {
4776
			if (!drbd_send_ping(tconn)) {
4777
				conn_err(tconn, "drbd_send_ping has failed\n");
4778 4779
				goto reconnect;
			}
4780 4781
			tconn->meta.socket->sk->sk_rcvtimeo =
				tconn->net_conf->ping_timeo*HZ/10;
4782
			ping_timeout_active = 1;
P
Philipp Reisner 已提交
4783 4784
		}

4785 4786 4787 4788
		/* TODO: conditionally cork; it may hurt latency if we cork without
		   much to send */
		if (!tconn->net_conf->no_cork)
			drbd_tcp_cork(tconn->meta.socket);
4789 4790
		if (tconn_process_done_ee(tconn)) {
			conn_err(tconn, "tconn_process_done_ee() failed\n");
4791
			goto reconnect;
4792
		}
P
Philipp Reisner 已提交
4793
		/* but unconditionally uncork unless disabled */
4794 4795
		if (!tconn->net_conf->no_cork)
			drbd_tcp_uncork(tconn->meta.socket);
P
Philipp Reisner 已提交
4796 4797 4798 4799 4800

		/* short circuit, recv_msg would return EINTR anyways. */
		if (signal_pending(current))
			continue;

4801 4802
		rv = drbd_recv_short(tconn->meta.socket, buf, expect-received, 0);
		clear_bit(SIGNAL_ASENDER, &tconn->flags);
P
Philipp Reisner 已提交
4803 4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814 4815 4816 4817 4818 4819

		flush_signals(current);

		/* Note:
		 * -EINTR	 (on meta) we got a signal
		 * -EAGAIN	 (on meta) rcvtimeo expired
		 * -ECONNRESET	 other side closed the connection
		 * -ERESTARTSYS  (on data) we got a signal
		 * rv <  0	 other than above: unexpected error!
		 * rv == expected: full header or command
		 * rv <  expected: "woken" by signal during receive
		 * rv == 0	 : "connection shut down by peer"
		 */
		if (likely(rv > 0)) {
			received += rv;
			buf	 += rv;
		} else if (rv == 0) {
4820
			conn_err(tconn, "meta connection shut down by peer.\n");
P
Philipp Reisner 已提交
4821 4822
			goto reconnect;
		} else if (rv == -EAGAIN) {
4823 4824
			/* If the data socket received something meanwhile,
			 * that is good enough: peer is still alive. */
4825 4826
			if (time_after(tconn->last_received,
				jiffies - tconn->meta.socket->sk->sk_rcvtimeo))
4827
				continue;
4828
			if (ping_timeout_active) {
4829
				conn_err(tconn, "PingAck did not arrive in time.\n");
P
Philipp Reisner 已提交
4830 4831
				goto reconnect;
			}
4832
			set_bit(SEND_PING, &tconn->flags);
P
Philipp Reisner 已提交
4833 4834 4835 4836
			continue;
		} else if (rv == -EINTR) {
			continue;
		} else {
4837
			conn_err(tconn, "sock_recvmsg returned %d\n", rv);
P
Philipp Reisner 已提交
4838 4839 4840 4841
			goto reconnect;
		}

		if (received == expect && cmd == NULL) {
4842
			if (decode_header(tconn, h, &pi))
P
Philipp Reisner 已提交
4843
				goto reconnect;
4844 4845
			cmd = &asender_tbl[pi.cmd];
			if (pi.cmd >= ARRAY_SIZE(asender_tbl) || !cmd) {
4846
				conn_err(tconn, "unknown command %d on meta (l: %d)\n",
4847
					pi.cmd, pi.size);
P
Philipp Reisner 已提交
4848 4849 4850
				goto disconnect;
			}
			expect = cmd->pkt_size;
4851
			if (pi.size != expect - sizeof(struct p_header)) {
4852
				conn_err(tconn, "Wrong packet size on meta (c: %d, l: %d)\n",
4853
					pi.cmd, pi.size);
P
Philipp Reisner 已提交
4854
				goto reconnect;
4855
			}
P
Philipp Reisner 已提交
4856 4857
		}
		if (received == expect) {
4858 4859 4860 4861 4862 4863 4864 4865 4866 4867
			bool rv;

			if (cmd->fa_type == CONN) {
				rv = cmd->conn_fn(tconn, pi.cmd);
			} else {
				struct drbd_conf *mdev = vnr_to_mdev(tconn, pi.vnr);
				rv = cmd->mdev_fn(mdev, pi.cmd);
			}

			if (!rv)
P
Philipp Reisner 已提交
4868 4869
				goto reconnect;

4870 4871
			tconn->last_received = jiffies;

4872 4873
			/* the idle_timeout (ping-int)
			 * has been restored in got_PingAck() */
4874
			if (cmd == &asender_tbl[P_PING_ACK])
4875 4876
				ping_timeout_active = 0;

P
Philipp Reisner 已提交
4877 4878
			buf	 = h;
			received = 0;
4879
			expect	 = sizeof(struct p_header);
P
Philipp Reisner 已提交
4880 4881 4882 4883 4884 4885
			cmd	 = NULL;
		}
	}

	if (0) {
reconnect:
4886
		conn_request_state(tconn, NS(conn, C_NETWORK_FAILURE), CS_HARD);
P
Philipp Reisner 已提交
4887 4888 4889
	}
	if (0) {
disconnect:
4890
		conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
P
Philipp Reisner 已提交
4891
	}
4892
	clear_bit(SIGNAL_ASENDER, &tconn->flags);
P
Philipp Reisner 已提交
4893

4894
	conn_info(tconn, "asender terminated\n");
P
Philipp Reisner 已提交
4895 4896 4897

	return 0;
}