drivers/block/drbd/drbd_receiver.c

   1 /*
   2    drbd_receiver.c
   3
   4    This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
   5
   6    Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
   7    Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
   8    Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
   9
  10    drbd is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 2, or (at your option)
  13    any later version.
  14
  15    drbd is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with drbd; see the file COPYING.  If not, write to
  22    the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  23  */
  24
  25
  26 #include <linux/module.h>
  27
  28 #include <linux/uaccess.h>
  29 #include <net/sock.h>
  30
  31 #include <linux/drbd.h>
  32 #include <linux/fs.h>
  33 #include <linux/file.h>
  34 #include <linux/in.h>
  35 #include <linux/mm.h>
  36 #include <linux/memcontrol.h>
  37 #include <linux/mm_inline.h>
  38 #include <linux/slab.h>
  39 #include <uapi/linux/sched/types.h>
  40 #include <linux/sched/signal.h>
  41 #include <linux/pkt_sched.h>
  42 #define __KERNEL_SYSCALLS__
  43 #include <linux/unistd.h>
  44 #include <linux/vmalloc.h>
  45 #include <linux/random.h>
  46 #include <linux/string.h>
  47 #include <linux/scatterlist.h>
  48 #include "drbd_int.h"
  49 #include "drbd_protocol.h"
  50 #include "drbd_req.h"
  51 #include "drbd_vli.h"
  52
  53 #define PRO_FEATURES (DRBD_FF_TRIM|DRBD_FF_THIN_RESYNC|DRBD_FF_WSAME)
  54
  55 struct packet_info {
  56         enum drbd_packet cmd;
  57         unsigned int size;
  58         unsigned int vnr;
  59         void *data;
  60 };
  61
  62 enum finish_epoch {
  63         FE_STILL_LIVE,
  64         FE_DESTROYED,
  65         FE_RECYCLED,
  66 };
  67
  68 static int drbd_do_features(struct drbd_connection *connection);
  69 static int drbd_do_auth(struct drbd_connection *connection);
  70 static int drbd_disconnected(struct drbd_peer_device *);
  71 static void conn_wait_active_ee_empty(struct drbd_connection *connection);
  72 static enum finish_epoch drbd_may_finish_epoch(struct drbd_connection *, struct drbd_epoch *, enum epoch_event);
  73 static int e_end_block(struct drbd_work *, int);
  74
  75
  76 #define GFP_TRY (__GFP_HIGHMEM | __GFP_NOWARN)
  77
  78 /*
  79  * some helper functions to deal with single linked page lists,
  80  * page->private being our "next" pointer.
  81  */
  82
  83 /* If at least n pages are linked at head, get n pages off.
  84  * Otherwise, don't modify head, and return NULL.
  85  * Locking is the responsibility of the caller.
  86  */
  87 static struct page *page_chain_del(struct page **head, int n)
  88 {
  89         struct page *page;
  90         struct page *tmp;
  91
  92         BUG_ON(!n);
  93         BUG_ON(!head);
  94
  95         page = *head;
  96
  97         if (!page)
  98                 return NULL;
  99
 100         while (page) {
 101                 tmp = page_chain_next(page);
 102                 if (--n == 0)
 103                         break; /* found sufficient pages */
 104                 if (tmp == NULL)
 105                         /* insufficient pages, don't use any of them. */
 106                         return NULL;
 107                 page = tmp;
 108         }
 109
 110         /* add end of list marker for the returned list */
 111         set_page_private(page, 0);
 112         /* actual return value, and adjustment of head */
 113         page = *head;
 114         *head = tmp;
 115         return page;
 116 }
 117
 118 /* may be used outside of locks to find the tail of a (usually short)
 119  * "private" page chain, before adding it back to a global chain head
 120  * with page_chain_add() under a spinlock. */
 121 static struct page *page_chain_tail(struct page *page, int *len)
 122 {
 123         struct page *tmp;
 124         int i = 1;
 125         while ((tmp = page_chain_next(page)))
 126                 ++i, page = tmp;
 127         if (len)
 128                 *len = i;
 129         return page;
 130 }
 131
 132 static int page_chain_free(struct page *page)
 133 {
 134         struct page *tmp;
 135         int i = 0;
 136         page_chain_for_each_safe(page, tmp) {
 137                 put_page(page);
 138                 ++i;
 139         }
 140         return i;
 141 }
 142
 143 static void page_chain_add(struct page **head,
 144                 struct page *chain_first, struct page *chain_last)
 145 {
 146 #if 1
 147         struct page *tmp;
 148         tmp = page_chain_tail(chain_first, NULL);
 149         BUG_ON(tmp != chain_last);
 150 #endif
 151
 152         /* add chain to head */
 153         set_page_private(chain_last, (unsigned long)*head);
 154         *head = chain_first;
 155 }
 156
 157 static struct page *__drbd_alloc_pages(struct drbd_device *device,
 158                                        unsigned int number)
 159 {
 160         struct page *page = NULL;
 161         struct page *tmp = NULL;
 162         unsigned int i = 0;
 163
 164         /* Yes, testing drbd_pp_vacant outside the lock is racy.
 165          * So what. It saves a spin_lock. */
 166         if (drbd_pp_vacant >= number) {
 167                 spin_lock(&drbd_pp_lock);
 168                 page = page_chain_del(&drbd_pp_pool, number);
 169                 if (page)
 170                         drbd_pp_vacant -= number;
 171                 spin_unlock(&drbd_pp_lock);
 172                 if (page)
 173                         return page;
 174         }
 175
 176         /* GFP_TRY, because we must not cause arbitrary write-out: in a DRBD
 177          * "criss-cross" setup, that might cause write-out on some other DRBD,
 178          * which in turn might block on the other node at this very place.  */
 179         for (i = 0; i < number; i++) {
 180                 tmp = alloc_page(GFP_TRY);
 181                 if (!tmp)
 182                         break;
 183                 set_page_private(tmp, (unsigned long)page);
 184                 page = tmp;
 185         }
 186
 187         if (i == number)
 188                 return page;
 189
 190         /* Not enough pages immediately available this time.
 191          * No need to jump around here, drbd_alloc_pages will retry this
 192          * function "soon". */
 193         if (page) {
 194                 tmp = page_chain_tail(page, NULL);
 195                 spin_lock(&drbd_pp_lock);
 196                 page_chain_add(&drbd_pp_pool, page, tmp);
 197                 drbd_pp_vacant += i;
 198                 spin_unlock(&drbd_pp_lock);
 199         }
 200         return NULL;
 201 }
 202
 203 static void reclaim_finished_net_peer_reqs(struct drbd_device *device,
 204                                            struct list_head *to_be_freed)
 205 {
 206         struct drbd_peer_request *peer_req, *tmp;
 207
 208         /* The EEs are always appended to the end of the list. Since
 209            they are sent in order over the wire, they have to finish
 210            in order. As soon as we see the first not finished we can
 211            stop to examine the list... */
 212
 213         list_for_each_entry_safe(peer_req, tmp, &device->net_ee, w.list) {
 214                 if (drbd_peer_req_has_active_page(peer_req))
 215                         break;
 216                 list_move(&peer_req->w.list, to_be_freed);
 217         }
 218 }
 219
 220 static void drbd_reclaim_net_peer_reqs(struct drbd_device *device)
 221 {
 222         LIST_HEAD(reclaimed);
 223         struct drbd_peer_request *peer_req, *t;
 224
 225         spin_lock_irq(&device->resource->req_lock);
 226         reclaim_finished_net_peer_reqs(device, &reclaimed);
 227         spin_unlock_irq(&device->resource->req_lock);
 228         list_for_each_entry_safe(peer_req, t, &reclaimed, w.list)
 229                 drbd_free_net_peer_req(device, peer_req);
 230 }
 231
 232 static void conn_reclaim_net_peer_reqs(struct drbd_connection *connection)
 233 {
 234         struct drbd_peer_device *peer_device;
 235         int vnr;
 236
 237         rcu_read_lock();
 238         idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
 239                 struct drbd_device *device = peer_device->device;
 240                 if (!atomic_read(&device->pp_in_use_by_net))
 241                         continue;
 242
 243                 kref_get(&device->kref);
 244                 rcu_read_unlock();
 245                 drbd_reclaim_net_peer_reqs(device);
 246                 kref_put(&device->kref, drbd_destroy_device);
 247                 rcu_read_lock();
 248         }
 249         rcu_read_unlock();
 250 }
 251
 252 /**
 253  * drbd_alloc_pages() - Returns @number pages, retries forever (or until signalled)
 254  * @device:     DRBD device.
 255  * @number:     number of pages requested
 256  * @retry:      whether to retry, if not enough pages are available right now
 257  *
 258  * Tries to allocate number pages, first from our own page pool, then from
 259  * the kernel.
 260  * Possibly retry until DRBD frees sufficient pages somewhere else.
 261  *
 262  * If this allocation would exceed the max_buffers setting, we throttle
 263  * allocation (schedule_timeout) to give the system some room to breathe.
 264  *
 265  * We do not use max-buffers as hard limit, because it could lead to
 266  * congestion and further to a distributed deadlock during online-verify or
 267  * (checksum based) resync, if the max-buffers, socket buffer sizes and
 268  * resync-rate settings are mis-configured.
 269  *
 270  * Returns a page chain linked via page->private.
 271  */
 272 struct page *drbd_alloc_pages(struct drbd_peer_device *peer_device, unsigned int number,
 273                               bool retry)
 274 {
 275         struct drbd_device *device = peer_device->device;
 276         struct page *page = NULL;
 277         struct net_conf *nc;
 278         DEFINE_WAIT(wait);
 279         unsigned int mxb;
 280
 281         rcu_read_lock();
 282         nc = rcu_dereference(peer_device->connection->net_conf);
 283         mxb = nc ? nc->max_buffers : 1000000;
 284         rcu_read_unlock();
 285
 286         if (atomic_read(&device->pp_in_use) < mxb)
 287                 page = __drbd_alloc_pages(device, number);
 288
 289         /* Try to keep the fast path fast, but occasionally we need
 290          * to reclaim the pages we lended to the network stack. */
 291         if (page && atomic_read(&device->pp_in_use_by_net) > 512)
 292                 drbd_reclaim_net_peer_reqs(device);
 293
 294         while (page == NULL) {
 295                 prepare_to_wait(&drbd_pp_wait, &wait, TASK_INTERRUPTIBLE);
 296
 297                 drbd_reclaim_net_peer_reqs(device);
 298
 299                 if (atomic_read(&device->pp_in_use) < mxb) {
 300                         page = __drbd_alloc_pages(device, number);
 301                         if (page)
 302                                 break;
 303                 }
 304
 305                 if (!retry)
 306                         break;
 307
 308                 if (signal_pending(current)) {
 309                         drbd_warn(device, "drbd_alloc_pages interrupted!\n");
 310                         break;
 311                 }
 312
 313                 if (schedule_timeout(HZ/10) == 0)
 314                         mxb = UINT_MAX;
 315         }
 316         finish_wait(&drbd_pp_wait, &wait);
 317
 318         if (page)
 319                 atomic_add(number, &device->pp_in_use);
 320         return page;
 321 }
 322
 323 /* Must not be used from irq, as that may deadlock: see drbd_alloc_pages.
 324  * Is also used from inside an other spin_lock_irq(&resource->req_lock);
 325  * Either links the page chain back to the global pool,
 326  * or returns all pages to the system. */
 327 static void drbd_free_pages(struct drbd_device *device, struct page *page, int is_net)
 328 {
 329         atomic_t *a = is_net ? &device->pp_in_use_by_net : &device->pp_in_use;
 330         int i;
 331
 332         if (page == NULL)
 333                 return;
 334
 335         if (drbd_pp_vacant > (DRBD_MAX_BIO_SIZE/PAGE_SIZE) * drbd_minor_count)
 336                 i = page_chain_free(page);
 337         else {
 338                 struct page *tmp;
 339                 tmp = page_chain_tail(page, &i);
 340                 spin_lock(&drbd_pp_lock);
 341                 page_chain_add(&drbd_pp_pool, page, tmp);
 342                 drbd_pp_vacant += i;
 343                 spin_unlock(&drbd_pp_lock);
 344         }
 345         i = atomic_sub_return(i, a);
 346         if (i < 0)
 347                 drbd_warn(device, "ASSERTION FAILED: %s: %d < 0\n",
 348                         is_net ? "pp_in_use_by_net" : "pp_in_use", i);
 349         wake_up(&drbd_pp_wait);
 350 }
 351
 352 /*
 353 You need to hold the req_lock:
 354  _drbd_wait_ee_list_empty()
 355
 356 You must not have the req_lock:
 357  drbd_free_peer_req()
 358  drbd_alloc_peer_req()
 359  drbd_free_peer_reqs()
 360  drbd_ee_fix_bhs()
 361  drbd_finish_peer_reqs()
 362  drbd_clear_done_ee()
 363  drbd_wait_ee_list_empty()
 364 */
 365
 366 /* normal: payload_size == request size (bi_size)
 367  * w_same: payload_size == logical_block_size
 368  * trim: payload_size == 0 */
 369 struct drbd_peer_request *
 370 drbd_alloc_peer_req(struct drbd_peer_device *peer_device, u64 id, sector_t sector,
 371                     unsigned int request_size, unsigned int payload_size, gfp_t gfp_mask) __must_hold(local)
 372 {
 373         struct drbd_device *device = peer_device->device;
 374         struct drbd_peer_request *peer_req;
 375         struct page *page = NULL;
 376         unsigned nr_pages = (payload_size + PAGE_SIZE -1) >> PAGE_SHIFT;
 377
 378         if (drbd_insert_fault(device, DRBD_FAULT_AL_EE))
 379                 return NULL;
 380
 381         peer_req = mempool_alloc(&drbd_ee_mempool, gfp_mask & ~__GFP_HIGHMEM);
 382         if (!peer_req) {
 383                 if (!(gfp_mask & __GFP_NOWARN))
 384                         drbd_err(device, "%s: allocation failed\n", __func__);
 385                 return NULL;
 386         }
 387
 388         if (nr_pages) {
 389                 page = drbd_alloc_pages(peer_device, nr_pages,
 390                                         gfpflags_allow_blocking(gfp_mask));
 391                 if (!page)
 392                         goto fail;
 393         }
 394
 395         memset(peer_req, 0, sizeof(*peer_req));
 396         INIT_LIST_HEAD(&peer_req->w.list);
 397         drbd_clear_interval(&peer_req->i);
 398         peer_req->i.size = request_size;
 399         peer_req->i.sector = sector;
 400         peer_req->submit_jif = jiffies;
 401         peer_req->peer_device = peer_device;
 402         peer_req->pages = page;
 403         /*
 404          * The block_id is opaque to the receiver.  It is not endianness
 405          * converted, and sent back to the sender unchanged.
 406          */
 407         peer_req->block_id = id;
 408
 409         return peer_req;
 410
 411  fail:
 412         mempool_free(peer_req, &drbd_ee_mempool);
 413         return NULL;
 414 }
 415
 416 void __drbd_free_peer_req(struct drbd_device *device, struct drbd_peer_request *peer_req,
 417                        int is_net)
 418 {
 419         might_sleep();
 420         if (peer_req->flags & EE_HAS_DIGEST)
 421                 kfree(peer_req->digest);
 422         drbd_free_pages(device, peer_req->pages, is_net);
 423         D_ASSERT(device, atomic_read(&peer_req->pending_bios) == 0);
 424         D_ASSERT(device, drbd_interval_empty(&peer_req->i));
 425         if (!expect(!(peer_req->flags & EE_CALL_AL_COMPLETE_IO))) {
 426                 peer_req->flags &= ~EE_CALL_AL_COMPLETE_IO;
 427                 drbd_al_complete_io(device, &peer_req->i);
 428         }
 429         mempool_free(peer_req, &drbd_ee_mempool);
 430 }
 431
 432 int drbd_free_peer_reqs(struct drbd_device *device, struct list_head *list)
 433 {
 434         LIST_HEAD(work_list);
 435         struct drbd_peer_request *peer_req, *t;
 436         int count = 0;
 437         int is_net = list == &device->net_ee;
 438
 439         spin_lock_irq(&device->resource->req_lock);
 440         list_splice_init(list, &work_list);
 441         spin_unlock_irq(&device->resource->req_lock);
 442
 443         list_for_each_entry_safe(peer_req, t, &work_list, w.list) {
 444                 __drbd_free_peer_req(device, peer_req, is_net);
 445                 count++;
 446         }
 447         return count;
 448 }
 449
 450 /*
 451  * See also comments in _req_mod(,BARRIER_ACKED) and receive_Barrier.
 452  */
 453 static int drbd_finish_peer_reqs(struct drbd_device *device)
 454 {
 455         LIST_HEAD(work_list);
 456         LIST_HEAD(reclaimed);
 457         struct drbd_peer_request *peer_req, *t;
 458         int err = 0;
 459
 460         spin_lock_irq(&device->resource->req_lock);
 461         reclaim_finished_net_peer_reqs(device, &reclaimed);
 462         list_splice_init(&device->done_ee, &work_list);
 463         spin_unlock_irq(&device->resource->req_lock);
 464
 465         list_for_each_entry_safe(peer_req, t, &reclaimed, w.list)
 466                 drbd_free_net_peer_req(device, peer_req);
 467
 468         /* possible callbacks here:
 469          * e_end_block, and e_end_resync_block, e_send_superseded.
 470          * all ignore the last argument.
 471          */
 472         list_for_each_entry_safe(peer_req, t, &work_list, w.list) {
 473                 int err2;
 474
 475                 /* list_del not necessary, next/prev members not touched */
 476                 err2 = peer_req->w.cb(&peer_req->w, !!err);
 477                 if (!err)
 478                         err = err2;
 479                 drbd_free_peer_req(device, peer_req);
 480         }
 481         wake_up(&device->ee_wait);
 482
 483         return err;
 484 }
 485
 486 static void _drbd_wait_ee_list_empty(struct drbd_device *device,
 487                                      struct list_head *head)
 488 {
 489         DEFINE_WAIT(wait);
 490
 491         /* avoids spin_lock/unlock
 492          * and calling prepare_to_wait in the fast path */
 493         while (!list_empty(head)) {
 494                 prepare_to_wait(&device->ee_wait, &wait, TASK_UNINTERRUPTIBLE);
 495                 spin_unlock_irq(&device->resource->req_lock);
 496                 io_schedule();
 497                 finish_wait(&device->ee_wait, &wait);
 498                 spin_lock_irq(&device->resource->req_lock);
 499         }
 500 }
 501
 502 static void drbd_wait_ee_list_empty(struct drbd_device *device,
 503                                     struct list_head *head)
 504 {
 505         spin_lock_irq(&device->resource->req_lock);
 506         _drbd_wait_ee_list_empty(device, head);
 507         spin_unlock_irq(&device->resource->req_lock);
 508 }
 509
 510 static int drbd_recv_short(struct socket *sock, void *buf, size_t size, int flags)
 511 {
 512         struct kvec iov = {
 513                 .iov_base = buf,
 514                 .iov_len = size,
 515         };
 516         struct msghdr msg = {
 517                 .msg_flags = (flags ? flags : MSG_WAITALL | MSG_NOSIGNAL)
 518         };
 519         iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, size);
 520         return sock_recvmsg(sock, &msg, msg.msg_flags);
 521 }
 522
 523 static int drbd_recv(struct drbd_connection *connection, void *buf, size_t size)
 524 {
 525         int rv;
 526
 527         rv = drbd_recv_short(connection->data.socket, buf, size, 0);
 528
 529         if (rv < 0) {
 530                 if (rv == -ECONNRESET)
 531                         drbd_info(connection, "sock was reset by peer\n");
 532                 else if (rv != -ERESTARTSYS)
 533                         drbd_err(connection, "sock_recvmsg returned %d\n", rv);
 534         } else if (rv == 0) {
 535                 if (test_bit(DISCONNECT_SENT, &connection->flags)) {
 536                         long t;
 537                         rcu_read_lock();
 538                         t = rcu_dereference(connection->net_conf)->ping_timeo * HZ/10;
 539                         rcu_read_unlock();
 540
 541                         t = wait_event_timeout(connection->ping_wait, connection->cstate < C_WF_REPORT_PARAMS, t);
 542
 543                         if (t)
 544                                 goto out;
 545                 }
 546                 drbd_info(connection, "sock was shut down by peer\n");
 547         }
 548
 549         if (rv != size)
 550                 conn_request_state(connection, NS(conn, C_BROKEN_PIPE), CS_HARD);
 551
 552 out:
 553         return rv;
 554 }
 555
 556 static int drbd_recv_all(struct drbd_connection *connection, void *buf, size_t size)
 557 {
 558         int err;
 559
 560         err = drbd_recv(connection, buf, size);
 561         if (err != size) {
 562                 if (err >= 0)
 563                         err = -EIO;
 564         } else
 565                 err = 0;
 566         return err;
 567 }
 568
 569 static int drbd_recv_all_warn(struct drbd_connection *connection, void *buf, size_t size)
 570 {
 571         int err;
 572
 573         err = drbd_recv_all(connection, buf, size);
 574         if (err && !signal_pending(current))
 575                 drbd_warn(connection, "short read (expected size %d)\n", (int)size);
 576         return err;
 577 }
 578
 579 /* quoting tcp(7):
 580  *   On individual connections, the socket buffer size must be set prior to the
 581  *   listen(2) or connect(2) calls in order to have it take effect.
 582  * This is our wrapper to do so.
 583  */
 584 static void drbd_setbufsize(struct socket *sock, unsigned int snd,
 585                 unsigned int rcv)
 586 {
 587         /* open coded SO_SNDBUF, SO_RCVBUF */
 588         if (snd) {
 589                 sock->sk->sk_sndbuf = snd;
 590                 sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
 591         }
 592         if (rcv) {
 593                 sock->sk->sk_rcvbuf = rcv;
 594                 sock->sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
 595         }
 596 }
 597
 598 static struct socket *drbd_try_connect(struct drbd_connection *connection)
 599 {
 600         const char *what;
 601         struct socket *sock;
 602         struct sockaddr_in6 src_in6;
 603         struct sockaddr_in6 peer_in6;
 604         struct net_conf *nc;
 605         int err, peer_addr_len, my_addr_len;
 606         int sndbuf_size, rcvbuf_size, connect_int;
 607         int disconnect_on_error = 1;
 608
 609         rcu_read_lock();
 610         nc = rcu_dereference(connection->net_conf);
 611         if (!nc) {
 612                 rcu_read_unlock();
 613                 return NULL;
 614         }
 615         sndbuf_size = nc->sndbuf_size;
 616         rcvbuf_size = nc->rcvbuf_size;
 617         connect_int = nc->connect_int;
 618         rcu_read_unlock();
 619
 620         my_addr_len = min_t(int, connection->my_addr_len, sizeof(src_in6));
 621         memcpy(&src_in6, &connection->my_addr, my_addr_len);
 622
 623         if (((struct sockaddr *)&connection->my_addr)->sa_family == AF_INET6)
 624                 src_in6.sin6_port = 0;
 625         else
 626                 ((struct sockaddr_in *)&src_in6)->sin_port = 0; /* AF_INET & AF_SCI */
 627
 628         peer_addr_len = min_t(int, connection->peer_addr_len, sizeof(src_in6));
 629         memcpy(&peer_in6, &connection->peer_addr, peer_addr_len);
 630
 631         what = "sock_create_kern";
 632         err = sock_create_kern(&init_net, ((struct sockaddr *)&src_in6)->sa_family,
 633                                SOCK_STREAM, IPPROTO_TCP, &sock);
 634         if (err < 0) {
 635                 sock = NULL;
 636                 goto out;
 637         }
 638
 639         sock->sk->sk_rcvtimeo =
 640         sock->sk->sk_sndtimeo = connect_int * HZ;
 641         drbd_setbufsize(sock, sndbuf_size, rcvbuf_size);
 642
 643        /* explicitly bind to the configured IP as source IP
 644         *  for the outgoing connections.
 645         *  This is needed for multihomed hosts and to be
 646         *  able to use lo: interfaces for drbd.
 647         * Make sure to use 0 as port number, so linux selects
 648         *  a free one dynamically.
 649         */
 650         what = "bind before connect";
 651         err = sock->ops->bind(sock, (struct sockaddr *) &src_in6, my_addr_len);
 652         if (err < 0)
 653                 goto out;
 654
 655         /* connect may fail, peer not yet available.
 656          * stay C_WF_CONNECTION, don't go Disconnecting! */
 657         disconnect_on_error = 0;
 658         what = "connect";
 659         err = sock->ops->connect(sock, (struct sockaddr *) &peer_in6, peer_addr_len, 0);
 660
 661 out:
 662         if (err < 0) {
 663                 if (sock) {
 664                         sock_release(sock);
 665                         sock = NULL;
 666                 }
 667                 switch (-err) {
 668                         /* timeout, busy, signal pending */
 669                 case ETIMEDOUT: case EAGAIN: case EINPROGRESS:
 670                 case EINTR: case ERESTARTSYS:
 671                         /* peer not (yet) available, network problem */
 672                 case ECONNREFUSED: case ENETUNREACH:
 673                 case EHOSTDOWN:    case EHOSTUNREACH:
 674                         disconnect_on_error = 0;
 675                         break;
 676                 default:
 677                         drbd_err(connection, "%s failed, err = %d\n", what, err);
 678                 }
 679                 if (disconnect_on_error)
 680                         conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD);
 681         }
 682
 683         return sock;
 684 }
 685
 686 struct accept_wait_data {
 687         struct drbd_connection *connection;
 688         struct socket *s_listen;
 689         struct completion door_bell;
 690         void (*original_sk_state_change)(struct sock *sk);
 691
 692 };
 693
 694 static void drbd_incoming_connection(struct sock *sk)
 695 {
 696         struct accept_wait_data *ad = sk->sk_user_data;
 697         void (*state_change)(struct sock *sk);
 698
 699         state_change = ad->original_sk_state_change;
 700         if (sk->sk_state == TCP_ESTABLISHED)
 701                 complete(&ad->door_bell);
 702         state_change(sk);
 703 }
 704
 705 static int prepare_listen_socket(struct drbd_connection *connection, struct accept_wait_data *ad)
 706 {
 707         int err, sndbuf_size, rcvbuf_size, my_addr_len;
 708         struct sockaddr_in6 my_addr;
 709         struct socket *s_listen;
 710         struct net_conf *nc;
 711         const char *what;
 712
 713         rcu_read_lock();
 714         nc = rcu_dereference(connection->net_conf);
 715         if (!nc) {
 716                 rcu_read_unlock();
 717                 return -EIO;
 718         }
 719         sndbuf_size = nc->sndbuf_size;
 720         rcvbuf_size = nc->rcvbuf_size;
 721         rcu_read_unlock();
 722
 723         my_addr_len = min_t(int, connection->my_addr_len, sizeof(struct sockaddr_in6));
 724         memcpy(&my_addr, &connection->my_addr, my_addr_len);
 725
 726         what = "sock_create_kern";
 727         err = sock_create_kern(&init_net, ((struct sockaddr *)&my_addr)->sa_family,
 728                                SOCK_STREAM, IPPROTO_TCP, &s_listen);
 729         if (err) {
 730                 s_listen = NULL;
 731                 goto out;
 732         }
 733
 734         s_listen->sk->sk_reuse = SK_CAN_REUSE; /* SO_REUSEADDR */
 735         drbd_setbufsize(s_listen, sndbuf_size, rcvbuf_size);
 736
 737         what = "bind before listen";
 738         err = s_listen->ops->bind(s_listen, (struct sockaddr *)&my_addr, my_addr_len);
 739         if (err < 0)
 740                 goto out;
 741
 742         ad->s_listen = s_listen;
 743         write_lock_bh(&s_listen->sk->sk_callback_lock);
 744         ad->original_sk_state_change = s_listen->sk->sk_state_change;
 745         s_listen->sk->sk_state_change = drbd_incoming_connection;
 746         s_listen->sk->sk_user_data = ad;
 747         write_unlock_bh(&s_listen->sk->sk_callback_lock);
 748
 749         what = "listen";
 750         err = s_listen->ops->listen(s_listen, 5);
 751         if (err < 0)
 752                 goto out;
 753
 754         return 0;
 755 out:
 756         if (s_listen)
 757                 sock_release(s_listen);
 758         if (err < 0) {
 759                 if (err != -EAGAIN && err != -EINTR && err != -ERESTARTSYS) {
 760                         drbd_err(connection, "%s failed, err = %d\n", what, err);
 761                         conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD);
 762                 }
 763         }
 764
 765         return -EIO;
 766 }
 767
 768 static void unregister_state_change(struct sock *sk, struct accept_wait_data *ad)
 769 {
 770         write_lock_bh(&sk->sk_callback_lock);
 771         sk->sk_state_change = ad->original_sk_state_change;
 772         sk->sk_user_data = NULL;
 773         write_unlock_bh(&sk->sk_callback_lock);
 774 }
 775
 776 static struct socket *drbd_wait_for_connect(struct drbd_connection *connection, struct accept_wait_data *ad)
 777 {
 778         int timeo, connect_int, err = 0;
 779         struct socket *s_estab = NULL;
 780         struct net_conf *nc;
 781
 782         rcu_read_lock();
 783         nc = rcu_dereference(connection->net_conf);
 784         if (!nc) {
 785                 rcu_read_unlock();
 786                 return NULL;
 787         }
 788         connect_int = nc->connect_int;
 789         rcu_read_unlock();
 790
 791         timeo = connect_int * HZ;
 792         /* 28.5% random jitter */
 793         timeo += (prandom_u32() & 1) ? timeo / 7 : -timeo / 7;
 794
 795         err = wait_for_completion_interruptible_timeout(&ad->door_bell, timeo);
 796         if (err <= 0)
 797                 return NULL;
 798
 799         err = kernel_accept(ad->s_listen, &s_estab, 0);
 800         if (err < 0) {
 801                 if (err != -EAGAIN && err != -EINTR && err != -ERESTARTSYS) {
 802                         drbd_err(connection, "accept failed, err = %d\n", err);
 803                         conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD);
 804                 }
 805         }
 806
 807         if (s_estab)
 808                 unregister_state_change(s_estab->sk, ad);
 809
 810         return s_estab;
 811 }
 812
 813 static int decode_header(struct drbd_connection *, void *, struct packet_info *);
 814
 815 static int send_first_packet(struct drbd_connection *connection, struct drbd_socket *sock,
 816                              enum drbd_packet cmd)
 817 {
 818         if (!conn_prepare_command(connection, sock))
 819                 return -EIO;
 820         return conn_send_command(connection, sock, cmd, 0, NULL, 0);
 821 }
 822
 823 static int receive_first_packet(struct drbd_connection *connection, struct socket *sock)
 824 {
 825         unsigned int header_size = drbd_header_size(connection);
 826         struct packet_info pi;
 827         struct net_conf *nc;
 828         int err;
 829
 830         rcu_read_lock();
 831         nc = rcu_dereference(connection->net_conf);
 832         if (!nc) {
 833                 rcu_read_unlock();
 834                 return -EIO;
 835         }
 836         sock->sk->sk_rcvtimeo = nc->ping_timeo * 4 * HZ / 10;
 837         rcu_read_unlock();
 838
 839         err = drbd_recv_short(sock, connection->data.rbuf, header_size, 0);
 840         if (err != header_size) {
 841                 if (err >= 0)
 842                         err = -EIO;
 843                 return err;
 844         }
 845         err = decode_header(connection, connection->data.rbuf, &pi);
 846         if (err)
 847                 return err;
 848         return pi.cmd;
 849 }
 850
 851 /**
 852  * drbd_socket_okay() - Free the socket if its connection is not okay
 853  * @sock:       pointer to the pointer to the socket.
 854  */
 855 static bool drbd_socket_okay(struct socket **sock)
 856 {
 857         int rr;
 858         char tb[4];
 859
 860         if (!*sock)
 861                 return false;
 862
 863         rr = drbd_recv_short(*sock, tb, 4, MSG_DONTWAIT | MSG_PEEK);
 864
 865         if (rr > 0 || rr == -EAGAIN) {
 866                 return true;
 867         } else {
 868                 sock_release(*sock);
 869                 *sock = NULL;
 870                 return false;
 871         }
 872 }
 873
 874 static bool connection_established(struct drbd_connection *connection,
 875                                    struct socket **sock1,
 876                                    struct socket **sock2)
 877 {
 878         struct net_conf *nc;
 879         int timeout;
 880         bool ok;
 881
 882         if (!*sock1 || !*sock2)
 883                 return false;
 884
 885         rcu_read_lock();
 886         nc = rcu_dereference(connection->net_conf);
 887         timeout = (nc->sock_check_timeo ?: nc->ping_timeo) * HZ / 10;
 888         rcu_read_unlock();
 889         schedule_timeout_interruptible(timeout);
 890
 891         ok = drbd_socket_okay(sock1);
 892         ok = drbd_socket_okay(sock2) && ok;
 893
 894         return ok;
 895 }
 896
 897 /* Gets called if a connection is established, or if a new minor gets created
 898    in a connection */
 899 int drbd_connected(struct drbd_peer_device *peer_device)
 900 {
 901         struct drbd_device *device = peer_device->device;
 902         int err;
 903
 904         atomic_set(&device->packet_seq, 0);
 905         device->peer_seq = 0;
 906
 907         device->state_mutex = peer_device->connection->agreed_pro_version < 100 ?
 908                 &peer_device->connection->cstate_mutex :
 909                 &device->own_state_mutex;
 910
 911         err = drbd_send_sync_param(peer_device);
 912         if (!err)
 913                 err = drbd_send_sizes(peer_device, 0, 0);
 914         if (!err)
 915                 err = drbd_send_uuids(peer_device);
 916         if (!err)
 917                 err = drbd_send_current_state(peer_device);
 918         clear_bit(USE_DEGR_WFC_T, &device->flags);
 919         clear_bit(RESIZE_PENDING, &device->flags);
 920         atomic_set(&device->ap_in_flight, 0);
 921         mod_timer(&device->request_timer, jiffies + HZ); /* just start it here. */
 922         return err;
 923 }
 924
 925 /*
 926  * return values:
 927  *   1 yes, we have a valid connection
 928  *   0 oops, did not work out, please try again
 929  *  -1 peer talks different language,
 930  *     no point in trying again, please go standalone.
 931  *  -2 We do not have a network config...
 932  */
 933 static int conn_connect(struct drbd_connection *connection)
 934 {
 935         struct drbd_socket sock, msock;
 936         struct drbd_peer_device *peer_device;
 937         struct net_conf *nc;
 938         int vnr, timeout, h;
 939         bool discard_my_data, ok;
 940         enum drbd_state_rv rv;
 941         struct accept_wait_data ad = {
 942                 .connection = connection,
 943                 .door_bell = COMPLETION_INITIALIZER_ONSTACK(ad.door_bell),
 944         };
 945
 946         clear_bit(DISCONNECT_SENT, &connection->flags);
 947         if (conn_request_state(connection, NS(conn, C_WF_CONNECTION), CS_VERBOSE) < SS_SUCCESS)
 948                 return -2;
 949
 950         mutex_init(&sock.mutex);
 951         sock.sbuf = connection->data.sbuf;
 952         sock.rbuf = connection->data.rbuf;
 953         sock.socket = NULL;
 954         mutex_init(&msock.mutex);
 955         msock.sbuf = connection->meta.sbuf;
 956         msock.rbuf = connection->meta.rbuf;
 957         msock.socket = NULL;
 958
 959         /* Assume that the peer only understands protocol 80 until we know better.  */
 960         connection->agreed_pro_version = 80;
 961
 962         if (prepare_listen_socket(connection, &ad))
 963                 return 0;
 964
 965         do {
 966                 struct socket *s;
 967
 968                 s = drbd_try_connect(connection);
 969                 if (s) {
 970                         if (!sock.socket) {
 971                                 sock.socket = s;
 972                                 send_first_packet(connection, &sock, P_INITIAL_DATA);
 973                         } else if (!msock.socket) {
 974                                 clear_bit(RESOLVE_CONFLICTS, &connection->flags);
 975                                 msock.socket = s;
 976                                 send_first_packet(connection, &msock, P_INITIAL_META);
 977                         } else {
 978                                 drbd_err(connection, "Logic error in conn_connect()\n");
 979                                 goto out_release_sockets;
 980                         }
 981                 }
 982
 983                 if (connection_established(connection, &sock.socket, &msock.socket))
 984                         break;
 985
 986 retry:
 987                 s = drbd_wait_for_connect(connection, &ad);
 988                 if (s) {
 989                         int fp = receive_first_packet(connection, s);
 990                         drbd_socket_okay(&sock.socket);
 991                         drbd_socket_okay(&msock.socket);
 992                         switch (fp) {
 993                         case P_INITIAL_DATA:
 994                                 if (sock.socket) {
 995                                         drbd_warn(connection, "initial packet S crossed\n");
 996                                         sock_release(sock.socket);
 997                                         sock.socket = s;
 998                                         goto randomize;
 999                                 }
1000                                 sock.socket = s;
1001                                 break;
1002                         case P_INITIAL_META:
1003                                 set_bit(RESOLVE_CONFLICTS, &connection->flags);
1004                                 if (msock.socket) {
1005                                         drbd_warn(connection, "initial packet M crossed\n");
1006                                         sock_release(msock.socket);
1007                                         msock.socket = s;
1008                                         goto randomize;
1009                                 }
1010                                 msock.socket = s;
1011                                 break;
1012                         default:
1013                                 drbd_warn(connection, "Error receiving initial packet\n");
1014                                 sock_release(s);
1015 randomize:
1016                                 if (prandom_u32() & 1)
1017                                         goto retry;
1018                         }
1019                 }
1020
1021                 if (connection->cstate <= C_DISCONNECTING)
1022                         goto out_release_sockets;
1023                 if (signal_pending(current)) {
1024                         flush_signals(current);
1025                         smp_rmb();
1026                         if (get_t_state(&connection->receiver) == EXITING)
1027                                 goto out_release_sockets;
1028                 }
1029
1030                 ok = connection_established(connection, &sock.socket, &msock.socket);
1031         } while (!ok);
1032
1033         if (ad.s_listen)
1034                 sock_release(ad.s_listen);
1035
1036         sock.socket->sk->sk_reuse = SK_CAN_REUSE; /* SO_REUSEADDR */
1037         msock.socket->sk->sk_reuse = SK_CAN_REUSE; /* SO_REUSEADDR */
1038
1039         sock.socket->sk->sk_allocation = GFP_NOIO;
1040         msock.socket->sk->sk_allocation = GFP_NOIO;
1041
1042         sock.socket->sk->sk_priority = TC_PRIO_INTERACTIVE_BULK;
1043         msock.socket->sk->sk_priority = TC_PRIO_INTERACTIVE;
1044
1045         /* NOT YET ...
1046          * sock.socket->sk->sk_sndtimeo = connection->net_conf->timeout*HZ/10;
1047          * sock.socket->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
1048          * first set it to the P_CONNECTION_FEATURES timeout,
1049          * which we set to 4x the configured ping_timeout. */
1050         rcu_read_lock();
1051         nc = rcu_dereference(connection->net_conf);
1052
1053         sock.socket->sk->sk_sndtimeo =
1054         sock.socket->sk->sk_rcvtimeo = nc->ping_timeo*4*HZ/10;
1055
1056         msock.socket->sk->sk_rcvtimeo = nc->ping_int*HZ;
1057         timeout = nc->timeout * HZ / 10;
1058         discard_my_data = nc->discard_my_data;
1059         rcu_read_unlock();
1060
1061         msock.socket->sk->sk_sndtimeo = timeout;
1062
1063         /* we don't want delays.
1064          * we use TCP_CORK where appropriate, though */
1065         drbd_tcp_nodelay(sock.socket);
1066         drbd_tcp_nodelay(msock.socket);
1067
1068         connection->data.socket = sock.socket;
1069         connection->meta.socket = msock.socket;
1070         connection->last_received = jiffies;
1071
1072         h = drbd_do_features(connection);
1073         if (h <= 0)
1074                 return h;
1075
1076         if (connection->cram_hmac_tfm) {
1077                 /* drbd_request_state(device, NS(conn, WFAuth)); */
1078                 switch (drbd_do_auth(connection)) {
1079                 case -1:
1080                         drbd_err(connection, "Authentication of peer failed\n");
1081                         return -1;
1082                 case 0:
1083                         drbd_err(connection, "Authentication of peer failed, trying again.\n");
1084                         return 0;
1085                 }
1086         }
1087
1088         connection->data.socket->sk->sk_sndtimeo = timeout;
1089         connection->data.socket->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
1090
1091         if (drbd_send_protocol(connection) == -EOPNOTSUPP)
1092                 return -1;
1093
1094         /* Prevent a race between resync-handshake and
1095          * being promoted to Primary.
1096          *
1097          * Grab and release the state mutex, so we know that any current
1098          * drbd_set_role() is finished, and any incoming drbd_set_role
1099          * will see the STATE_SENT flag, and wait for it to be cleared.
1100          */
1101         idr_for_each_entry(&connection->peer_devices, peer_device, vnr)
1102                 mutex_lock(peer_device->device->state_mutex);
1103
1104         /* avoid a race with conn_request_state( C_DISCONNECTING ) */
1105         spin_lock_irq(&connection->resource->req_lock);
1106         set_bit(STATE_SENT, &connection->flags);
1107         spin_unlock_irq(&connection->resource->req_lock);
1108
1109         idr_for_each_entry(&connection->peer_devices, peer_device, vnr)
1110                 mutex_unlock(peer_device->device->state_mutex);
1111
1112         rcu_read_lock();
1113         idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
1114                 struct drbd_device *device = peer_device->device;
1115                 kref_get(&device->kref);
1116                 rcu_read_unlock();
1117
1118                 if (discard_my_data)
1119                         set_bit(DISCARD_MY_DATA, &device->flags);
1120                 else
1121                         clear_bit(DISCARD_MY_DATA, &device->flags);
1122
1123                 drbd_connected(peer_device);
1124                 kref_put(&device->kref, drbd_destroy_device);
1125                 rcu_read_lock();
1126         }
1127         rcu_read_unlock();
1128
1129         rv = conn_request_state(connection, NS(conn, C_WF_REPORT_PARAMS), CS_VERBOSE);
1130         if (rv < SS_SUCCESS || connection->cstate != C_WF_REPORT_PARAMS) {
1131                 clear_bit(STATE_SENT, &connection->flags);
1132                 return 0;
1133         }
1134
1135         drbd_thread_start(&connection->ack_receiver);
1136         /* opencoded create_singlethread_workqueue(),
1137          * to be able to use format string arguments */
1138         connection->ack_sender =
1139                 alloc_ordered_workqueue("drbd_as_%s", WQ_MEM_RECLAIM, connection->resource->name);
1140         if (!connection->ack_sender) {
1141                 drbd_err(connection, "Failed to create workqueue ack_sender\n");
1142                 return 0;
1143         }
1144
1145         mutex_lock(&connection->resource->conf_update);
1146         /* The discard_my_data flag is a single-shot modifier to the next
1147          * connection attempt, the handshake of which is now well underway.
1148          * No need for rcu style copying of the whole struct
1149          * just to clear a single value. */
1150         connection->net_conf->discard_my_data = 0;
1151         mutex_unlock(&connection->resource->conf_update);
1152
1153         return h;
1154
1155 out_release_sockets:
1156         if (ad.s_listen)
1157                 sock_release(ad.s_listen);
1158         if (sock.socket)
1159                 sock_release(sock.socket);
1160         if (msock.socket)
1161                 sock_release(msock.socket);
1162         return -1;
1163 }
1164
1165 static int decode_header(struct drbd_connection *connection, void *header, struct packet_info *pi)
1166 {
1167         unsigned int header_size = drbd_header_size(connection);
1168
1169         if (header_size == sizeof(struct p_header100) &&
1170             *(__be32 *)header == cpu_to_be32(DRBD_MAGIC_100)) {
1171                 struct p_header100 *h = header;
1172                 if (h->pad != 0) {
1173                         drbd_err(connection, "Header padding is not zero\n");
1174                         return -EINVAL;
1175                 }
1176                 pi->vnr = be16_to_cpu(h->volume);
1177                 pi->cmd = be16_to_cpu(h->command);
1178                 pi->size = be32_to_cpu(h->length);
1179         } else if (header_size == sizeof(struct p_header95) &&
1180                    *(__be16 *)header == cpu_to_be16(DRBD_MAGIC_BIG)) {
1181                 struct p_header95 *h = header;
1182                 pi->cmd = be16_to_cpu(h->command);
1183                 pi->size = be32_to_cpu(h->length);
1184                 pi->vnr = 0;
1185         } else if (header_size == sizeof(struct p_header80) &&
1186                    *(__be32 *)header == cpu_to_be32(DRBD_MAGIC)) {
1187                 struct p_header80 *h = header;
1188                 pi->cmd = be16_to_cpu(h->command);
1189                 pi->size = be16_to_cpu(h->length);
1190                 pi->vnr = 0;
1191         } else {
1192                 drbd_err(connection, "Wrong magic value 0x%08x in protocol version %d\n",
1193                          be32_to_cpu(*(__be32 *)header),
1194                          connection->agreed_pro_version);
1195                 return -EINVAL;
1196         }
1197         pi->data = header + header_size;
1198         return 0;
1199 }
1200
1201 static void drbd_unplug_all_devices(struct drbd_connection *connection)
1202 {
1203         if (current->plug == &connection->receiver_plug) {
1204                 blk_finish_plug(&connection->receiver_plug);
1205                 blk_start_plug(&connection->receiver_plug);
1206         } /* else: maybe just schedule() ?? */
1207 }
1208
1209 static int drbd_recv_header(struct drbd_connection *connection, struct packet_info *pi)
1210 {
1211         void *buffer = connection->data.rbuf;
1212         int err;
1213
1214         err = drbd_recv_all_warn(connection, buffer, drbd_header_size(connection));
1215         if (err)
1216                 return err;
1217
1218         err = decode_header(connection, buffer, pi);
1219         connection->last_received = jiffies;
1220
1221         return err;
1222 }
1223
1224 static int drbd_recv_header_maybe_unplug(struct drbd_connection *connection, struct packet_info *pi)
1225 {
1226         void *buffer = connection->data.rbuf;
1227         unsigned int size = drbd_header_size(connection);
1228         int err;
1229
1230         err = drbd_recv_short(connection->data.socket, buffer, size, MSG_NOSIGNAL|MSG_DONTWAIT);
1231         if (err != size) {
1232                 /* If we have nothing in the receive buffer now, to reduce
1233                  * application latency, try to drain the backend queues as
1234                  * quickly as possible, and let remote TCP know what we have
1235                  * received so far. */
1236                 if (err == -EAGAIN) {
1237                         drbd_tcp_quickack(connection->data.socket);
1238                         drbd_unplug_all_devices(connection);
1239                 }
1240                 if (err > 0) {
1241                         buffer += err;
1242                         size -= err;
1243                 }
1244                 err = drbd_recv_all_warn(connection, buffer, size);
1245                 if (err)
1246                         return err;
1247         }
1248
1249         err = decode_header(connection, connection->data.rbuf, pi);
1250         connection->last_received = jiffies;
1251
1252         return err;
1253 }
1254 /* This is blkdev_issue_flush, but asynchronous.
1255  * We want to submit to all component volumes in parallel,
1256  * then wait for all completions.
1257  */
1258 struct issue_flush_context {
1259         atomic_t pending;
1260         int error;
1261         struct completion done;
1262 };
1263 struct one_flush_context {
1264         struct drbd_device *device;
1265         struct issue_flush_context *ctx;
1266 };
1267
1268 static void one_flush_endio(struct bio *bio)
1269 {
1270         struct one_flush_context *octx = bio->bi_private;
1271         struct drbd_device *device = octx->device;
1272         struct issue_flush_context *ctx = octx->ctx;
1273
1274         if (bio->bi_status) {
1275                 ctx->error = blk_status_to_errno(bio->bi_status);
1276                 drbd_info(device, "local disk FLUSH FAILED with status %d\n", bio->bi_status);
1277         }
1278         kfree(octx);
1279         bio_put(bio);
1280
1281         clear_bit(FLUSH_PENDING, &device->flags);
1282         put_ldev(device);
1283         kref_put(&device->kref, drbd_destroy_device);
1284
1285         if (atomic_dec_and_test(&ctx->pending))
1286                 complete(&ctx->done);
1287 }
1288
1289 static void submit_one_flush(struct drbd_device *device, struct issue_flush_context *ctx)
1290 {
1291         struct bio *bio = bio_alloc(GFP_NOIO, 0);
1292         struct one_flush_context *octx = kmalloc(sizeof(*octx), GFP_NOIO);
1293         if (!bio || !octx) {
1294                 drbd_warn(device, "Could not allocate a bio, CANNOT ISSUE FLUSH\n");
1295                 /* FIXME: what else can I do now?  disconnecting or detaching
1296                  * really does not help to improve the state of the world, either.
1297                  */
1298                 kfree(octx);
1299                 if (bio)
1300                         bio_put(bio);
1301
1302                 ctx->error = -ENOMEM;
1303                 put_ldev(device);
1304                 kref_put(&device->kref, drbd_destroy_device);
1305                 return;
1306         }
1307
1308         octx->device = device;
1309         octx->ctx = ctx;
1310         bio_set_dev(bio, device->ldev->backing_bdev);
1311         bio->bi_private = octx;
1312         bio->bi_end_io = one_flush_endio;
1313         bio->bi_opf = REQ_OP_FLUSH | REQ_PREFLUSH;
1314
1315         device->flush_jif = jiffies;
1316         set_bit(FLUSH_PENDING, &device->flags);
1317         atomic_inc(&ctx->pending);
1318         submit_bio(bio);
1319 }
1320
1321 static void drbd_flush(struct drbd_connection *connection)
1322 {
1323         if (connection->resource->write_ordering >= WO_BDEV_FLUSH) {
1324                 struct drbd_peer_device *peer_device;
1325                 struct issue_flush_context ctx;
1326                 int vnr;
1327
1328                 atomic_set(&ctx.pending, 1);
1329                 ctx.error = 0;
1330                 init_completion(&ctx.done);
1331
1332                 rcu_read_lock();
1333                 idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
1334                         struct drbd_device *device = peer_device->device;
1335
1336                         if (!get_ldev(device))
1337                                 continue;
1338                         kref_get(&device->kref);
1339                         rcu_read_unlock();
1340
1341                         submit_one_flush(device, &ctx);
1342
1343                         rcu_read_lock();
1344                 }
1345                 rcu_read_unlock();
1346
1347                 /* Do we want to add a timeout,
1348                  * if disk-timeout is set? */
1349                 if (!atomic_dec_and_test(&ctx.pending))
1350                         wait_for_completion(&ctx.done);
1351
1352                 if (ctx.error) {
1353                         /* would rather check on EOPNOTSUPP, but that is not reliable.
1354                          * don't try again for ANY return value != 0
1355                          * if (rv == -EOPNOTSUPP) */
1356                         /* Any error is already reported by bio_endio callback. */
1357                         drbd_bump_write_ordering(connection->resource, NULL, WO_DRAIN_IO);
1358                 }
1359         }
1360 }
1361
1362 /**
1363  * drbd_may_finish_epoch() - Applies an epoch_event to the epoch's state, eventually finishes it.
1364  * @device:     DRBD device.
1365  * @epoch:      Epoch object.
1366  * @ev:         Epoch event.
1367  */
1368 static enum finish_epoch drbd_may_finish_epoch(struct drbd_connection *connection,
1369                                                struct drbd_epoch *epoch,
1370                                                enum epoch_event ev)
1371 {
1372         int epoch_size;
1373         struct drbd_epoch *next_epoch;
1374         enum finish_epoch rv = FE_STILL_LIVE;
1375
1376         spin_lock(&connection->epoch_lock);
1377         do {
1378                 next_epoch = NULL;
1379
1380                 epoch_size = atomic_read(&epoch->epoch_size);
1381
1382                 switch (ev & ~EV_CLEANUP) {
1383                 case EV_PUT:
1384                         atomic_dec(&epoch->active);
1385                         break;
1386                 case EV_GOT_BARRIER_NR:
1387                         set_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags);
1388                         break;
1389                 case EV_BECAME_LAST:
1390                         /* nothing to do*/
1391                         break;
1392                 }
1393
1394                 if (epoch_size != 0 &&
1395                     atomic_read(&epoch->active) == 0 &&
1396                     (test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags) || ev & EV_CLEANUP)) {
1397                         if (!(ev & EV_CLEANUP)) {
1398                                 spin_unlock(&connection->epoch_lock);
1399                                 drbd_send_b_ack(epoch->connection, epoch->barrier_nr, epoch_size);
1400                                 spin_lock(&connection->epoch_lock);
1401                         }
1402 #if 0
1403                         /* FIXME: dec unacked on connection, once we have
1404                          * something to count pending connection packets in. */
1405                         if (test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags))
1406                                 dec_unacked(epoch->connection);
1407 #endif
1408
1409                         if (connection->current_epoch != epoch) {
1410                                 next_epoch = list_entry(epoch->list.next, struct drbd_epoch, list);
1411                                 list_del(&epoch->list);
1412                                 ev = EV_BECAME_LAST | (ev & EV_CLEANUP);
1413                                 connection->epochs--;
1414                                 kfree(epoch);
1415
1416                                 if (rv == FE_STILL_LIVE)
1417                                         rv = FE_DESTROYED;
1418                         } else {
1419                                 epoch->flags = 0;
1420                                 atomic_set(&epoch->epoch_size, 0);
1421                                 /* atomic_set(&epoch->active, 0); is already zero */
1422                                 if (rv == FE_STILL_LIVE)
1423                                         rv = FE_RECYCLED;
1424                         }
1425                 }
1426
1427                 if (!next_epoch)
1428                         break;
1429
1430                 epoch = next_epoch;
1431         } while (1);
1432
1433         spin_unlock(&connection->epoch_lock);
1434
1435         return rv;
1436 }
1437
1438 static enum write_ordering_e
1439 max_allowed_wo(struct drbd_backing_dev *bdev, enum write_ordering_e wo)
1440 {
1441         struct disk_conf *dc;
1442
1443         dc = rcu_dereference(bdev->disk_conf);
1444
1445         if (wo == WO_BDEV_FLUSH && !dc->disk_flushes)
1446                 wo = WO_DRAIN_IO;
1447         if (wo == WO_DRAIN_IO && !dc->disk_drain)
1448                 wo = WO_NONE;
1449
1450         return wo;
1451 }
1452
1453 /**
1454  * drbd_bump_write_ordering() - Fall back to an other write ordering method
1455  * @connection: DRBD connection.
1456  * @wo:         Write ordering method to try.
1457  */
1458 void drbd_bump_write_ordering(struct drbd_resource *resource, struct drbd_backing_dev *bdev,
1459                               enum write_ordering_e wo)
1460 {
1461         struct drbd_device *device;
1462         enum write_ordering_e pwo;
1463         int vnr;
1464         static char *write_ordering_str[] = {
1465                 [WO_NONE] = "none",
1466                 [WO_DRAIN_IO] = "drain",
1467                 [WO_BDEV_FLUSH] = "flush",
1468         };
1469
1470         pwo = resource->write_ordering;
1471         if (wo != WO_BDEV_FLUSH)
1472                 wo = min(pwo, wo);
1473         rcu_read_lock();
1474         idr_for_each_entry(&resource->devices, device, vnr) {
1475                 if (get_ldev(device)) {
1476                         wo = max_allowed_wo(device->ldev, wo);
1477                         if (device->ldev == bdev)
1478                                 bdev = NULL;
1479                         put_ldev(device);
1480                 }
1481         }
1482
1483         if (bdev)
1484                 wo = max_allowed_wo(bdev, wo);
1485
1486         rcu_read_unlock();
1487
1488         resource->write_ordering = wo;
1489         if (pwo != resource->write_ordering || wo == WO_BDEV_FLUSH)
1490                 drbd_info(resource, "Method to ensure write ordering: %s\n", write_ordering_str[resource->write_ordering]);
1491 }
1492
1493 static void drbd_issue_peer_discard(struct drbd_device *device, struct drbd_peer_request *peer_req)
1494 {
1495         struct block_device *bdev = device->ldev->backing_bdev;
1496
1497         if (blkdev_issue_zeroout(bdev, peer_req->i.sector, peer_req->i.size >> 9,
1498                         GFP_NOIO, 0))
1499                 peer_req->flags |= EE_WAS_ERROR;
1500
1501         drbd_endio_write_sec_final(peer_req);
1502 }
1503
1504 static void drbd_issue_peer_wsame(struct drbd_device *device,
1505                                   struct drbd_peer_request *peer_req)
1506 {
1507         struct block_device *bdev = device->ldev->backing_bdev;
1508         sector_t s = peer_req->i.sector;
1509         sector_t nr = peer_req->i.size >> 9;
1510         if (blkdev_issue_write_same(bdev, s, nr, GFP_NOIO, peer_req->pages))
1511                 peer_req->flags |= EE_WAS_ERROR;
1512         drbd_endio_write_sec_final(peer_req);
1513 }
1514
1515
1516 /**
1517  * drbd_submit_peer_request()
1518  * @device:     DRBD device.
1519  * @peer_req:   peer request
1520  * @rw:         flag field, see bio->bi_opf
1521  *
1522  * May spread the pages to multiple bios,
1523  * depending on bio_add_page restrictions.
1524  *
1525  * Returns 0 if all bios have been submitted,
1526  * -ENOMEM if we could not allocate enough bios,
1527  * -ENOSPC (any better suggestion?) if we have not been able to bio_add_page a
1528  *  single page to an empty bio (which should never happen and likely indicates
1529  *  that the lower level IO stack is in some way broken). This has been observed
1530  *  on certain Xen deployments.
1531  */
1532 /* TODO allocate from our own bio_set. */
1533 int drbd_submit_peer_request(struct drbd_device *device,
1534                              struct drbd_peer_request *peer_req,
1535                              const unsigned op, const unsigned op_flags,
1536                              const int fault_type)
1537 {
1538         struct bio *bios = NULL;
1539         struct bio *bio;
1540         struct page *page = peer_req->pages;
1541         sector_t sector = peer_req->i.sector;
1542         unsigned data_size = peer_req->i.size;
1543         unsigned n_bios = 0;
1544         unsigned nr_pages = (data_size + PAGE_SIZE -1) >> PAGE_SHIFT;
1545         int err = -ENOMEM;
1546
1547         /* TRIM/DISCARD: for now, always use the helper function
1548          * blkdev_issue_zeroout(..., discard=true).
1549          * It's synchronous, but it does the right thing wrt. bio splitting.
1550          * Correctness first, performance later.  Next step is to code an
1551          * asynchronous variant of the same.
1552          */
1553         if (peer_req->flags & (EE_IS_TRIM|EE_WRITE_SAME)) {
1554                 /* wait for all pending IO completions, before we start
1555                  * zeroing things out. */
1556                 conn_wait_active_ee_empty(peer_req->peer_device->connection);
1557                 /* add it to the active list now,
1558                  * so we can find it to present it in debugfs */
1559                 peer_req->submit_jif = jiffies;
1560                 peer_req->flags |= EE_SUBMITTED;
1561
1562                 /* If this was a resync request from receive_rs_deallocated(),
1563                  * it is already on the sync_ee list */
1564                 if (list_empty(&peer_req->w.list)) {
1565                         spin_lock_irq(&device->resource->req_lock);
1566                         list_add_tail(&peer_req->w.list, &device->active_ee);
1567                         spin_unlock_irq(&device->resource->req_lock);
1568                 }
1569
1570                 if (peer_req->flags & EE_IS_TRIM)
1571                         drbd_issue_peer_discard(device, peer_req);
1572                 else /* EE_WRITE_SAME */
1573                         drbd_issue_peer_wsame(device, peer_req);
1574                 return 0;
1575         }
1576
1577         /* In most cases, we will only need one bio.  But in case the lower
1578          * level restrictions happen to be different at this offset on this
1579          * side than those of the sending peer, we may need to submit the
1580          * request in more than one bio.
1581          *
1582          * Plain bio_alloc is good enough here, this is no DRBD internally
1583          * generated bio, but a bio allocated on behalf of the peer.
1584          */
1585 next_bio:
1586         bio = bio_alloc(GFP_NOIO, nr_pages);
1587         if (!bio) {
1588                 drbd_err(device, "submit_ee: Allocation of a bio failed (nr_pages=%u)\n", nr_pages);
1589                 goto fail;
1590         }
1591         /* > peer_req->i.sector, unless this is the first bio */
1592         bio->bi_iter.bi_sector = sector;
1593         bio_set_dev(bio, device->ldev->backing_bdev);
1594         bio_set_op_attrs(bio, op, op_flags);
1595         bio->bi_private = peer_req;
1596         bio->bi_end_io = drbd_peer_request_endio;
1597
1598         bio->bi_next = bios;
1599         bios = bio;
1600         ++n_bios;
1601
1602         page_chain_for_each(page) {
1603                 unsigned len = min_t(unsigned, data_size, PAGE_SIZE);
1604                 if (!bio_add_page(bio, page, len, 0))
1605                         goto next_bio;
1606                 data_size -= len;
1607                 sector += len >> 9;
1608                 --nr_pages;
1609         }
1610         D_ASSERT(device, data_size == 0);
1611         D_ASSERT(device, page == NULL);
1612
1613         atomic_set(&peer_req->pending_bios, n_bios);
1614         /* for debugfs: update timestamp, mark as submitted */
1615         peer_req->submit_jif = jiffies;
1616         peer_req->flags |= EE_SUBMITTED;
1617         do {
1618                 bio = bios;
1619                 bios = bios->bi_next;
1620                 bio->bi_next = NULL;
1621
1622                 drbd_generic_make_request(device, fault_type, bio);
1623         } while (bios);
1624         return 0;
1625
1626 fail:
1627         while (bios) {
1628                 bio = bios;
1629                 bios = bios->bi_next;
1630                 bio_put(bio);
1631         }
1632         return err;
1633 }
1634
1635 static void drbd_remove_epoch_entry_interval(struct drbd_device *device,
1636                                              struct drbd_peer_request *peer_req)
1637 {
1638         struct drbd_interval *i = &peer_req->i;
1639
1640         drbd_remove_interval(&device->write_requests, i);
1641         drbd_clear_interval(i);
1642
1643         /* Wake up any processes waiting for this peer request to complete.  */
1644         if (i->waiting)
1645                 wake_up(&device->misc_wait);
1646 }
1647
1648 static void conn_wait_active_ee_empty(struct drbd_connection *connection)
1649 {
1650         struct drbd_peer_device *peer_device;
1651         int vnr;
1652
1653         rcu_read_lock();
1654         idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
1655                 struct drbd_device *device = peer_device->device;
1656
1657                 kref_get(&device->kref);
1658                 rcu_read_unlock();
1659                 drbd_wait_ee_list_empty(device, &device->active_ee);
1660                 kref_put(&device->kref, drbd_destroy_device);
1661                 rcu_read_lock();
1662         }
1663         rcu_read_unlock();
1664 }
1665
1666 static int receive_Barrier(struct drbd_connection *connection, struct packet_info *pi)
1667 {
1668         int rv;
1669         struct p_barrier *p = pi->data;
1670         struct drbd_epoch *epoch;
1671
1672         /* FIXME these are unacked on connection,
1673          * not a specific (peer)device.
1674          */
1675         connection->current_epoch->barrier_nr = p->barrier;
1676         connection->current_epoch->connection = connection;
1677         rv = drbd_may_finish_epoch(connection, connection->current_epoch, EV_GOT_BARRIER_NR);
1678
1679         /* P_BARRIER_ACK may imply that the corresponding extent is dropped from
1680          * the activity log, which means it would not be resynced in case the
1681          * R_PRIMARY crashes now.
1682          * Therefore we must send the barrier_ack after the barrier request was
1683          * completed. */
1684         switch (connection->resource->write_ordering) {
1685         case WO_NONE:
1686                 if (rv == FE_RECYCLED)
1687                         return 0;
1688
1689                 /* receiver context, in the writeout path of the other node.
1690                  * avoid potential distributed deadlock */
1691                 epoch = kmalloc(sizeof(struct drbd_epoch), GFP_NOIO);
1692                 if (epoch)
1693                         break;
1694                 else
1695                         drbd_warn(connection, "Allocation of an epoch failed, slowing down\n");
1696                         /* Fall through */
1697
1698         case WO_BDEV_FLUSH:
1699         case WO_DRAIN_IO:
1700                 conn_wait_active_ee_empty(connection);
1701                 drbd_flush(connection);
1702
1703                 if (atomic_read(&connection->current_epoch->epoch_size)) {
1704                         epoch = kmalloc(sizeof(struct drbd_epoch), GFP_NOIO);
1705                         if (epoch)
1706                                 break;
1707                 }
1708
1709                 return 0;
1710         default:
1711                 drbd_err(connection, "Strangeness in connection->write_ordering %d\n",
1712                          connection->resource->write_ordering);
1713                 return -EIO;
1714         }
1715
1716         epoch->flags = 0;
1717         atomic_set(&epoch->epoch_size, 0);
1718         atomic_set(&epoch->active, 0);
1719
1720         spin_lock(&connection->epoch_lock);
1721         if (atomic_read(&connection->current_epoch->epoch_size)) {
1722                 list_add(&epoch->list, &connection->current_epoch->list);
1723                 connection->current_epoch = epoch;
1724                 connection->epochs++;
1725         } else {
1726                 /* The current_epoch got recycled while we allocated this one... */
1727                 kfree(epoch);
1728         }
1729         spin_unlock(&connection->epoch_lock);
1730
1731         return 0;
1732 }
1733
1734 /* quick wrapper in case payload size != request_size (write same) */
1735 static void drbd_csum_ee_size(struct crypto_ahash *h,
1736                               struct drbd_peer_request *r, void *d,
1737                               unsigned int payload_size)
1738 {
1739         unsigned int tmp = r->i.size;
1740         r->i.size = payload_size;
1741         drbd_csum_ee(h, r, d);
1742         r->i.size = tmp;
1743 }
1744
1745 /* used from receive_RSDataReply (recv_resync_read)
1746  * and from receive_Data.
1747  * data_size: actual payload ("data in")
1748  *      for normal writes that is bi_size.
1749  *      for discards, that is zero.
1750  *      for write same, it is logical_block_size.
1751  * both trim and write same have the bi_size ("data len to be affected")
1752  * as extra argument in the packet header.
1753  */
1754 static struct drbd_peer_request *
1755 read_in_block(struct drbd_peer_device *peer_device, u64 id, sector_t sector,
1756               struct packet_info *pi) __must_hold(local)
1757 {
1758         struct drbd_device *device = peer_device->device;
1759         const sector_t capacity = drbd_get_capacity(device->this_bdev);
1760         struct drbd_peer_request *peer_req;
1761         struct page *page;
1762         int digest_size, err;
1763         unsigned int data_size = pi->size, ds;
1764         void *dig_in = peer_device->connection->int_dig_in;
1765         void *dig_vv = peer_device->connection->int_dig_vv;
1766         unsigned long *data;
1767         struct p_trim *trim = (pi->cmd == P_TRIM) ? pi->data : NULL;
1768         struct p_trim *wsame = (pi->cmd == P_WSAME) ? pi->data : NULL;
1769
1770         digest_size = 0;
1771         if (!trim && peer_device->connection->peer_integrity_tfm) {
1772                 digest_size = crypto_ahash_digestsize(peer_device->connection->peer_integrity_tfm);
1773                 /*
1774                  * FIXME: Receive the incoming digest into the receive buffer
1775                  *        here, together with its struct p_data?
1776                  */
1777                 err = drbd_recv_all_warn(peer_device->connection, dig_in, digest_size);
1778                 if (err)
1779                         return NULL;
1780                 data_size -= digest_size;
1781         }
1782
1783         /* assume request_size == data_size, but special case trim and wsame. */
1784         ds = data_size;
1785         if (trim) {
1786                 if (!expect(data_size == 0))
1787                         return NULL;
1788                 ds = be32_to_cpu(trim->size);
1789         } else if (wsame) {
1790                 if (data_size != queue_logical_block_size(device->rq_queue)) {
1791                         drbd_err(peer_device, "data size (%u) != drbd logical block size (%u)\n",
1792                                 data_size, queue_logical_block_size(device->rq_queue));
1793                         return NULL;
1794                 }
1795                 if (data_size != bdev_logical_block_size(device->ldev->backing_bdev)) {
1796                         drbd_err(peer_device, "data size (%u) != backend logical block size (%u)\n",
1797                                 data_size, bdev_logical_block_size(device->ldev->backing_bdev));
1798                         return NULL;
1799                 }
1800                 ds = be32_to_cpu(wsame->size);
1801         }
1802
1803         if (!expect(IS_ALIGNED(ds, 512)))
1804                 return NULL;
1805         if (trim || wsame) {
1806                 if (!expect(ds <= (DRBD_MAX_BBIO_SECTORS << 9)))
1807                         return NULL;
1808         } else if (!expect(ds <= DRBD_MAX_BIO_SIZE))
1809                 return NULL;
1810
1811         /* even though we trust out peer,
1812          * we sometimes have to double check. */
1813         if (sector + (ds>>9) > capacity) {
1814                 drbd_err(device, "request from peer beyond end of local disk: "
1815                         "capacity: %llus < sector: %llus + size: %u\n",
1816                         (unsigned long long)capacity,
1817                         (unsigned long long)sector, ds);
1818                 return NULL;
1819         }
1820
1821         /* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD
1822          * "criss-cross" setup, that might cause write-out on some other DRBD,
1823          * which in turn might block on the other node at this very place.  */
1824         peer_req = drbd_alloc_peer_req(peer_device, id, sector, ds, data_size, GFP_NOIO);
1825         if (!peer_req)
1826                 return NULL;
1827
1828         peer_req->flags |= EE_WRITE;
1829         if (trim) {
1830                 peer_req->flags |= EE_IS_TRIM;
1831                 return peer_req;
1832         }
1833         if (wsame)
1834                 peer_req->flags |= EE_WRITE_SAME;
1835
1836         /* receive payload size bytes into page chain */
1837         ds = data_size;
1838         page = peer_req->pages;
1839         page_chain_for_each(page) {
1840                 unsigned len = min_t(int, ds, PAGE_SIZE);
1841                 data = kmap(page);
1842                 err = drbd_recv_all_warn(peer_device->connection, data, len);
1843                 if (drbd_insert_fault(device, DRBD_FAULT_RECEIVE)) {
1844                         drbd_err(device, "Fault injection: Corrupting data on receive\n");
1845                         data[0] = data[0] ^ (unsigned long)-1;
1846                 }
1847                 kunmap(page);
1848                 if (err) {
1849                         drbd_free_peer_req(device, peer_req);
1850                         return NULL;
1851                 }
1852                 ds -= len;
1853         }
1854
1855         if (digest_size) {
1856                 drbd_csum_ee_size(peer_device->connection->peer_integrity_tfm, peer_req, dig_vv, data_size);
1857                 if (memcmp(dig_in, dig_vv, digest_size)) {
1858                         drbd_err(device, "Digest integrity check FAILED: %llus +%u\n",
1859                                 (unsigned long long)sector, data_size);
1860                         drbd_free_peer_req(device, peer_req);
1861                         return NULL;
1862                 }
1863         }
1864         device->recv_cnt += data_size >> 9;
1865         return peer_req;
1866 }
1867
1868 /* drbd_drain_block() just takes a data block
1869  * out of the socket input buffer, and discards it.
1870  */
1871 static int drbd_drain_block(struct drbd_peer_device *peer_device, int data_size)
1872 {
1873         struct page *page;
1874         int err = 0;
1875         void *data;
1876
1877         if (!data_size)
1878                 return 0;
1879
1880         page = drbd_alloc_pages(peer_device, 1, 1);
1881
1882         data = kmap(page);
1883         while (data_size) {
1884                 unsigned int len = min_t(int, data_size, PAGE_SIZE);
1885
1886                 err = drbd_recv_all_warn(peer_device->connection, data, len);
1887                 if (err)
1888                         break;
1889                 data_size -= len;
1890         }
1891         kunmap(page);
1892         drbd_free_pages(peer_device->device, page, 0);
1893         return err;
1894 }
1895
1896 static int recv_dless_read(struct drbd_peer_device *peer_device, struct drbd_request *req,
1897                            sector_t sector, int data_size)
1898 {
1899         struct bio_vec bvec;
1900         struct bvec_iter iter;
1901         struct bio *bio;
1902         int digest_size, err, expect;
1903         void *dig_in = peer_device->connection->int_dig_in;
1904         void *dig_vv = peer_device->connection->int_dig_vv;
1905
1906         digest_size = 0;
1907         if (peer_device->connection->peer_integrity_tfm) {
1908                 digest_size = crypto_ahash_digestsize(peer_device->connection->peer_integrity_tfm);
1909                 err = drbd_recv_all_warn(peer_device->connection, dig_in, digest_size);
1910                 if (err)
1911                         return err;
1912                 data_size -= digest_size;
1913         }
1914
1915         /* optimistically update recv_cnt.  if receiving fails below,
1916          * we disconnect anyways, and counters will be reset. */
1917         peer_device->device->recv_cnt += data_size>>9;
1918
1919         bio = req->master_bio;
1920         D_ASSERT(peer_device->device, sector == bio->bi_iter.bi_sector);
1921
1922         bio_for_each_segment(bvec, bio, iter) {
1923                 void *mapped = kmap(bvec.bv_page) + bvec.bv_offset;
1924                 expect = min_t(int, data_size, bvec.bv_len);
1925                 err = drbd_recv_all_warn(peer_device->connection, mapped, expect);
1926                 kunmap(bvec.bv_page);
1927                 if (err)
1928                         return err;
1929                 data_size -= expect;
1930         }
1931
1932         if (digest_size) {
1933                 drbd_csum_bio(peer_device->connection->peer_integrity_tfm, bio, dig_vv);
1934                 if (memcmp(dig_in, dig_vv, digest_size)) {
1935                         drbd_err(peer_device, "Digest integrity check FAILED. Broken NICs?\n");
1936                         return -EINVAL;
1937                 }
1938         }
1939
1940         D_ASSERT(peer_device->device, data_size == 0);
1941         return 0;
1942 }
1943
1944 /*
1945  * e_end_resync_block() is called in ack_sender context via
1946  * drbd_finish_peer_reqs().
1947  */
1948 static int e_end_resync_block(struct drbd_work *w, int unused)
1949 {
1950         struct drbd_peer_request *peer_req =
1951                 container_of(w, struct drbd_peer_request, w);
1952         struct drbd_peer_device *peer_device = peer_req->peer_device;
1953         struct drbd_device *device = peer_device->device;
1954         sector_t sector = peer_req->i.sector;
1955         int err;
1956
1957         D_ASSERT(device, drbd_interval_empty(&peer_req->i));
1958
1959         if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
1960                 drbd_set_in_sync(device, sector, peer_req->i.size);
1961                 err = drbd_send_ack(peer_device, P_RS_WRITE_ACK, peer_req);
1962         } else {
1963                 /* Record failure to sync */
1964                 drbd_rs_failed_io(device, sector, peer_req->i.size);
1965
1966                 err  = drbd_send_ack(peer_device, P_NEG_ACK, peer_req);
1967         }
1968         dec_unacked(device);
1969
1970         return err;
1971 }
1972
1973 static int recv_resync_read(struct drbd_peer_device *peer_device, sector_t sector,
1974                             struct packet_info *pi) __releases(local)
1975 {
1976         struct drbd_device *device = peer_device->device;
1977         struct drbd_peer_request *peer_req;
1978
1979         peer_req = read_in_block(peer_device, ID_SYNCER, sector, pi);
1980         if (!peer_req)
1981                 goto fail;
1982
1983         dec_rs_pending(device);
1984
1985         inc_unacked(device);
1986         /* corresponding dec_unacked() in e_end_resync_block()
1987          * respective _drbd_clear_done_ee */
1988
1989         peer_req->w.cb = e_end_resync_block;
1990         peer_req->submit_jif = jiffies;
1991
1992         spin_lock_irq(&device->resource->req_lock);
1993         list_add_tail(&peer_req->w.list, &device->sync_ee);
1994         spin_unlock_irq(&device->resource->req_lock);
1995
1996         atomic_add(pi->size >> 9, &device->rs_sect_ev);
1997         if (drbd_submit_peer_request(device, peer_req, REQ_OP_WRITE, 0,
1998                                      DRBD_FAULT_RS_WR) == 0)
1999                 return 0;
2000
2001         /* don't care for the reason here */
2002         drbd_err(device, "submit failed, triggering re-connect\n");
2003         spin_lock_irq(&device->resource->req_lock);
2004         list_del(&peer_req->w.list);
2005         spin_unlock_irq(&device->resource->req_lock);
2006
2007         drbd_free_peer_req(device, peer_req);
2008 fail:
2009         put_ldev(device);
2010         return -EIO;
2011 }
2012
2013 static struct drbd_request *
2014 find_request(struct drbd_device *device, struct rb_root *root, u64 id,
2015              sector_t sector, bool missing_ok, const char *func)
2016 {
2017         struct drbd_request *req;
2018
2019         /* Request object according to our peer */
2020         req = (struct drbd_request *)(unsigned long)id;
2021         if (drbd_contains_interval(root, sector, &req->i) && req->i.local)
2022                 return req;
2023         if (!missing_ok) {
2024                 drbd_err(device, "%s: failed to find request 0x%lx, sector %llus\n", func,
2025                         (unsigned long)id, (unsigned long long)sector);
2026         }
2027         return NULL;
2028 }
2029
2030 static int receive_DataReply(struct drbd_connection *connection, struct packet_info *pi)
2031 {
2032         struct drbd_peer_device *peer_device;
2033         struct drbd_device *device;
2034         struct drbd_request *req;
2035         sector_t sector;
2036         int err;
2037         struct p_data *p = pi->data;
2038
2039         peer_device = conn_peer_device(connection, pi->vnr);
2040         if (!peer_device)
2041                 return -EIO;
2042         device = peer_device->device;
2043
2044         sector = be64_to_cpu(p->sector);
2045
2046         spin_lock_irq(&device->resource->req_lock);
2047         req = find_request(device, &device->read_requests, p->block_id, sector, false, __func__);
2048         spin_unlock_irq(&device->resource->req_lock);
2049         if (unlikely(!req))
2050                 return -EIO;
2051
2052         /* hlist_del(&req->collision) is done in _req_may_be_done, to avoid
2053          * special casing it there for the various failure cases.
2054          * still no race with drbd_fail_pending_reads */
2055         err = recv_dless_read(peer_device, req, sector, pi->size);
2056         if (!err)
2057                 req_mod(req, DATA_RECEIVED);
2058         /* else: nothing. handled from drbd_disconnect...
2059          * I don't think we may complete this just yet
2060          * in case we are "on-disconnect: freeze" */
2061
2062         return err;
2063 }
2064
2065 static int receive_RSDataReply(struct drbd_connection *connection, struct packet_info *pi)
2066 {
2067         struct drbd_peer_device *peer_device;
2068         struct drbd_device *device;
2069         sector_t sector;
2070         int err;
2071         struct p_data *p = pi->data;
2072
2073         peer_device = conn_peer_device(connection, pi->vnr);
2074         if (!peer_device)
2075                 return -EIO;
2076         device = peer_device->device;
2077
2078         sector = be64_to_cpu(p->sector);
2079         D_ASSERT(device, p->block_id == ID_SYNCER);
2080
2081         if (get_ldev(device)) {
2082                 /* data is submitted to disk within recv_resync_read.
2083                  * corresponding put_ldev done below on error,
2084                  * or in drbd_peer_request_endio. */
2085                 err = recv_resync_read(peer_device, sector, pi);
2086         } else {
2087                 if (__ratelimit(&drbd_ratelimit_state))
2088                         drbd_err(device, "Can not write resync data to local disk.\n");
2089
2090                 err = drbd_drain_block(peer_device, pi->size);
2091
2092                 drbd_send_ack_dp(peer_device, P_NEG_ACK, p, pi->size);
2093         }
2094
2095         atomic_add(pi->size >> 9, &device->rs_sect_in);
2096
2097         return err;
2098 }
2099
2100 static void restart_conflicting_writes(struct drbd_device *device,
2101                                        sector_t sector, int size)
2102 {
2103         struct drbd_interval *i;
2104         struct drbd_request *req;
2105
2106         drbd_for_each_overlap(i, &device->write_requests, sector, size) {
2107                 if (!i->local)
2108                         continue;
2109                 req = container_of(i, struct drbd_request, i);
2110                 if (req->rq_state & RQ_LOCAL_PENDING ||
2111                     !(req->rq_state & RQ_POSTPONED))
2112                         continue;
2113                 /* as it is RQ_POSTPONED, this will cause it to
2114                  * be queued on the retry workqueue. */
2115                 __req_mod(req, CONFLICT_RESOLVED, NULL);
2116         }
2117 }
2118
2119 /*
2120  * e_end_block() is called in ack_sender context via drbd_finish_peer_reqs().
2121  */
2122 static int e_end_block(struct drbd_work *w, int cancel)
2123 {
2124         struct drbd_peer_request *peer_req =
2125                 container_of(w, struct drbd_peer_request, w);
2126         struct drbd_peer_device *peer_device = peer_req->peer_device;
2127         struct drbd_device *device = peer_device->device;
2128         sector_t sector = peer_req->i.sector;
2129         int err = 0, pcmd;
2130
2131         if (peer_req->flags & EE_SEND_WRITE_ACK) {
2132                 if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
2133                         pcmd = (device->state.conn >= C_SYNC_SOURCE &&
2134                                 device->state.conn <= C_PAUSED_SYNC_T &&
2135                                 peer_req->flags & EE_MAY_SET_IN_SYNC) ?
2136                                 P_RS_WRITE_ACK : P_WRITE_ACK;
2137                         err = drbd_send_ack(peer_device, pcmd, peer_req);
2138                         if (pcmd == P_RS_WRITE_ACK)
2139                                 drbd_set_in_sync(device, sector, peer_req->i.size);
2140                 } else {
2141                         err = drbd_send_ack(peer_device, P_NEG_ACK, peer_req);
2142                         /* we expect it to be marked out of sync anyways...
2143                          * maybe assert this?  */
2144                 }
2145                 dec_unacked(device);
2146         }
2147
2148         /* we delete from the conflict detection hash _after_ we sent out the
2149          * P_WRITE_ACK / P_NEG_ACK, to get the sequence number right.  */
2150         if (peer_req->flags & EE_IN_INTERVAL_TREE) {
2151                 spin_lock_irq(&device->resource->req_lock);
2152                 D_ASSERT(device, !drbd_interval_empty(&peer_req->i));
2153                 drbd_remove_epoch_entry_interval(device, peer_req);
2154                 if (peer_req->flags & EE_RESTART_REQUESTS)
2155                         restart_conflicting_writes(device, sector, peer_req->i.size);
2156                 spin_unlock_irq(&device->resource->req_lock);
2157         } else
2158                 D_ASSERT(device, drbd_interval_empty(&peer_req->i));
2159
2160         drbd_may_finish_epoch(peer_device->connection, peer_req->epoch, EV_PUT + (cancel ? EV_CLEANUP : 0));
2161
2162         return err;
2163 }
2164
2165 static int e_send_ack(struct drbd_work *w, enum drbd_packet ack)
2166 {
2167         struct drbd_peer_request *peer_req =
2168                 container_of(w, struct drbd_peer_request, w);
2169         struct drbd_peer_device *peer_device = peer_req->peer_device;
2170         int err;
2171
2172         err = drbd_send_ack(peer_device, ack, peer_req);
2173         dec_unacked(peer_device->device);
2174
2175         return err;
2176 }
2177
2178 static int e_send_superseded(struct drbd_work *w, int unused)
2179 {
2180         return e_send_ack(w, P_SUPERSEDED);
2181 }
2182
2183 static int e_send_retry_write(struct drbd_work *w, int unused)
2184 {
2185         struct drbd_peer_request *peer_req =
2186                 container_of(w, struct drbd_peer_request, w);
2187         struct drbd_connection *connection = peer_req->peer_device->connection;
2188
2189         return e_send_ack(w, connection->agreed_pro_version >= 100 ?
2190                              P_RETRY_WRITE : P_SUPERSEDED);
2191 }
2192
2193 static bool seq_greater(u32 a, u32 b)
2194 {
2195         /*
2196          * We assume 32-bit wrap-around here.
2197          * For 24-bit wrap-around, we would have to shift:
2198          *  a <<= 8; b <<= 8;
2199          */
2200         return (s32)a - (s32)b > 0;
2201 }
2202
2203 static u32 seq_max(u32 a, u32 b)
2204 {
2205         return seq_greater(a, b) ? a : b;
2206 }
2207
2208 static void update_peer_seq(struct drbd_peer_device *peer_device, unsigned int peer_seq)
2209 {
2210         struct drbd_device *device = peer_device->device;
2211         unsigned int newest_peer_seq;
2212
2213         if (test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags)) {
2214                 spin_lock(&device->peer_seq_lock);
2215                 newest_peer_seq = seq_max(device->peer_seq, peer_seq);
2216                 device->peer_seq = newest_peer_seq;
2217                 spin_unlock(&device->peer_seq_lock);
2218                 /* wake up only if we actually changed device->peer_seq */
2219                 if (peer_seq == newest_peer_seq)
2220                         wake_up(&device->seq_wait);
2221         }
2222 }
2223
2224 static inline int overlaps(sector_t s1, int l1, sector_t s2, int l2)
2225 {
2226         return !((s1 + (l1>>9) <= s2) || (s1 >= s2 + (l2>>9)));
2227 }
2228
2229 /* maybe change sync_ee into interval trees as well? */
2230 static bool overlapping_resync_write(struct drbd_device *device, struct drbd_peer_request *peer_req)
2231 {
2232         struct drbd_peer_request *rs_req;
2233         bool rv = false;
2234
2235         spin_lock_irq(&device->resource->req_lock);
2236         list_for_each_entry(rs_req, &device->sync_ee, w.list) {
2237                 if (overlaps(peer_req->i.sector, peer_req->i.size,
2238                              rs_req->i.sector, rs_req->i.size)) {
2239                         rv = true;
2240                         break;
2241                 }
2242         }
2243         spin_unlock_irq(&device->resource->req_lock);
2244
2245         return rv;
2246 }
2247
2248 /* Called from receive_Data.
2249  * Synchronize packets on sock with packets on msock.
2250  *
2251  * This is here so even when a P_DATA packet traveling via sock overtook an Ack
2252  * packet traveling on msock, they are still processed in the order they have
2253  * been sent.
2254  *
2255  * Note: we don't care for Ack packets overtaking P_DATA packets.
2256  *
2257  * In case packet_seq is larger than device->peer_seq number, there are
2258  * outstanding packets on the msock. We wait for them to arrive.
2259  * In case we are the logically next packet, we update device->peer_seq
2260  * ourselves. Correctly handles 32bit wrap around.
2261  *
2262  * Assume we have a 10 GBit connection, that is about 1<<30 byte per second,
2263  * about 1<<21 sectors per second. So "worst" case, we have 1<<3 == 8 seconds
2264  * for the 24bit wrap (historical atomic_t guarantee on some archs), and we have
2265  * 1<<9 == 512 seconds aka ages for the 32bit wrap around...
2266  *
2267  * returns 0 if we may process the packet,
2268  * -ERESTARTSYS if we were interrupted (by disconnect signal). */
2269 static int wait_for_and_update_peer_seq(struct drbd_peer_device *peer_device, const u32 peer_seq)
2270 {
2271         struct drbd_device *device = peer_device->device;
2272         DEFINE_WAIT(wait);
2273         long timeout;
2274         int ret = 0, tp;
2275
2276         if (!test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags))
2277                 return 0;
2278
2279         spin_lock(&device->peer_seq_lock);
2280         for (;;) {
2281                 if (!seq_greater(peer_seq - 1, device->peer_seq)) {
2282                         device->peer_seq = seq_max(device->peer_seq, peer_seq);
2283                         break;
2284                 }
2285
2286                 if (signal_pending(current)) {
2287                         ret = -ERESTARTSYS;
2288                         break;
2289                 }
2290
2291                 rcu_read_lock();
2292                 tp = rcu_dereference(peer_device->connection->net_conf)->two_primaries;
2293                 rcu_read_unlock();
2294
2295                 if (!tp)
2296                         break;
2297
2298                 /* Only need to wait if two_primaries is enabled */
2299                 prepare_to_wait(&device->seq_wait, &wait, TASK_INTERRUPTIBLE);
2300                 spin_unlock(&device->peer_seq_lock);
2301                 rcu_read_lock();
2302                 timeout = rcu_dereference(peer_device->connection->net_conf)->ping_timeo*HZ/10;
2303                 rcu_read_unlock();
2304                 timeout = schedule_timeout(timeout);
2305                 spin_lock(&device->peer_seq_lock);
2306                 if (!timeout) {
2307                         ret = -ETIMEDOUT;
2308                         drbd_err(device, "Timed out waiting for missing ack packets; disconnecting\n");
2309                         break;
2310                 }
2311         }
2312         spin_unlock(&device->peer_seq_lock);
2313         finish_wait(&device->seq_wait, &wait);
2314         return ret;
2315 }
2316
2317 /* see also bio_flags_to_wire()
2318  * DRBD_REQ_*, because we need to semantically map the flags to data packet
2319  * flags and back. We may replicate to other kernel versions. */
2320 static unsigned long wire_flags_to_bio_flags(u32 dpf)
2321 {
2322         return  (dpf & DP_RW_SYNC ? REQ_SYNC : 0) |
2323                 (dpf & DP_FUA ? REQ_FUA : 0) |
2324                 (dpf & DP_FLUSH ? REQ_PREFLUSH : 0);
2325 }
2326
2327 static unsigned long wire_flags_to_bio_op(u32 dpf)
2328 {
2329         if (dpf & DP_DISCARD)
2330                 return REQ_OP_WRITE_ZEROES;
2331         else
2332                 return REQ_OP_WRITE;
2333 }
2334
2335 static void fail_postponed_requests(struct drbd_device *device, sector_t sector,
2336                                     unsigned int size)
2337 {
2338         struct drbd_interval *i;
2339
2340     repeat:
2341         drbd_for_each_overlap(i, &device->write_requests, sector, size) {
2342                 struct drbd_request *req;
2343                 struct bio_and_error m;
2344
2345                 if (!i->local)
2346                         continue;
2347                 req = container_of(i, struct drbd_request, i);
2348                 if (!(req->rq_state & RQ_POSTPONED))
2349                         continue;
2350                 req->rq_state &= ~RQ_POSTPONED;
2351                 __req_mod(req, NEG_ACKED, &m);
2352                 spin_unlock_irq(&device->resource->req_lock);
2353                 if (m.bio)
2354                         complete_master_bio(device, &m);
2355                 spin_lock_irq(&device->resource->req_lock);
2356                 goto repeat;
2357         }
2358 }
2359
2360 static int handle_write_conflicts(struct drbd_device *device,
2361                                   struct drbd_peer_request *peer_req)
2362 {
2363         struct drbd_connection *connection = peer_req->peer_device->connection;
2364         bool resolve_conflicts = test_bit(RESOLVE_CONFLICTS, &connection->flags);
2365         sector_t sector = peer_req->i.sector;
2366         const unsigned int size = peer_req->i.size;
2367         struct drbd_interval *i;
2368         bool equal;
2369         int err;
2370
2371         /*
2372          * Inserting the peer request into the write_requests tree will prevent
2373          * new conflicting local requests from being added.
2374          */
2375         drbd_insert_interval(&device->write_requests, &peer_req->i);
2376
2377     repeat:
2378         drbd_for_each_overlap(i, &device->write_requests, sector, size) {
2379                 if (i == &peer_req->i)
2380                         continue;
2381                 if (i->completed)
2382                         continue;
2383
2384                 if (!i->local) {
2385                         /*
2386                          * Our peer has sent a conflicting remote request; this
2387                          * should not happen in a two-node setup.  Wait for the
2388                          * earlier peer request to complete.
2389                          */
2390                         err = drbd_wait_misc(device, i);
2391                         if (err)
2392                                 goto out;
2393                         goto repeat;
2394                 }
2395
2396                 equal = i->sector == sector && i->size == size;
2397                 if (resolve_conflicts) {
2398                         /*
2399                          * If the peer request is fully contained within the
2400                          * overlapping request, it can be considered overwritten
2401                          * and thus superseded; otherwise, it will be retried
2402                          * once all overlapping requests have completed.
2403                          */
2404                         bool superseded = i->sector <= sector && i->sector +
2405                                        (i->size >> 9) >= sector + (size >> 9);
2406
2407                         if (!equal)
2408                                 drbd_alert(device, "Concurrent writes detected: "
2409                                                "local=%llus +%u, remote=%llus +%u, "
2410                                                "assuming %s came first\n",
2411                                           (unsigned long long)i->sector, i->size,
2412                                           (unsigned long long)sector, size,
2413                                           superseded ? "local" : "remote");
2414
2415                         peer_req->w.cb = superseded ? e_send_superseded :
2416                                                    e_send_retry_write;
2417                         list_add_tail(&peer_req->w.list, &device->done_ee);
2418                         queue_work(connection->ack_sender, &peer_req->peer_device->send_acks_work);
2419
2420                         err = -ENOENT;
2421                         goto out;
2422                 } else {
2423                         struct drbd_request *req =
2424                                 container_of(i, struct drbd_request, i);
2425
2426                         if (!equal)
2427                                 drbd_alert(device, "Concurrent writes detected: "
2428                                                "local=%llus +%u, remote=%llus +%u\n",
2429                                           (unsigned long long)i->sector, i->size,
2430                                           (unsigned long long)sector, size);
2431
2432                         if (req->rq_state & RQ_LOCAL_PENDING ||
2433                             !(req->rq_state & RQ_POSTPONED)) {
2434                                 /*
2435                                  * Wait for the node with the discard flag to
2436                                  * decide if this request has been superseded
2437                                  * or needs to be retried.
2438                                  * Requests that have been superseded will
2439                                  * disappear from the write_requests tree.
2440                                  *
2441                                  * In addition, wait for the conflicting
2442                                  * request to finish locally before submitting
2443                                  * the conflicting peer request.
2444                                  */
2445                                 err = drbd_wait_misc(device, &req->i);
2446                                 if (err) {
2447                                         _conn_request_state(connection, NS(conn, C_TIMEOUT), CS_HARD);
2448                                         fail_postponed_requests(device, sector, size);
2449                                         goto out;
2450                                 }
2451                                 goto repeat;
2452                         }
2453                         /*
2454                          * Remember to restart the conflicting requests after
2455                          * the new peer request has completed.
2456                          */
2457                         peer_req->flags |= EE_RESTART_REQUESTS;
2458                 }
2459         }
2460         err = 0;
2461
2462     out:
2463         if (err)
2464                 drbd_remove_epoch_entry_interval(device, peer_req);
2465         return err;
2466 }
2467
2468 /* mirrored write */
2469 static int receive_Data(struct drbd_connection *connection, struct packet_info *pi)
2470 {
2471         struct drbd_peer_device *peer_device;
2472         struct drbd_device *device;
2473         struct net_conf *nc;
2474         sector_t sector;
2475         struct drbd_peer_request *peer_req;
2476         struct p_data *p = pi->data;
2477         u32 peer_seq = be32_to_cpu(p->seq_num);
2478         int op, op_flags;
2479         u32 dp_flags;
2480         int err, tp;
2481
2482         peer_device = conn_peer_device(connection, pi->vnr);
2483         if (!peer_device)
2484                 return -EIO;
2485         device = peer_device->device;
2486
2487         if (!get_ldev(device)) {
2488                 int err2;
2489
2490                 err = wait_for_and_update_peer_seq(peer_device, peer_seq);
2491                 drbd_send_ack_dp(peer_device, P_NEG_ACK, p, pi->size);
2492                 atomic_inc(&connection->current_epoch->epoch_size);
2493                 err2 = drbd_drain_block(peer_device, pi->size);
2494                 if (!err)
2495                         err = err2;
2496                 return err;
2497         }
2498
2499         /*
2500          * Corresponding put_ldev done either below (on various errors), or in
2501          * drbd_peer_request_endio, if we successfully submit the data at the
2502          * end of this function.
2503          */
2504
2505         sector = be64_to_cpu(p->sector);
2506         peer_req = read_in_block(peer_device, p->block_id, sector, pi);
2507         if (!peer_req) {
2508                 put_ldev(device);
2509                 return -EIO;
2510         }
2511
2512         peer_req->w.cb = e_end_block;
2513         peer_req->submit_jif = jiffies;
2514         peer_req->flags |= EE_APPLICATION;
2515
2516         dp_flags = be32_to_cpu(p->dp_flags);
2517         op = wire_flags_to_bio_op(dp_flags);
2518         op_flags = wire_flags_to_bio_flags(dp_flags);
2519         if (pi->cmd == P_TRIM) {
2520                 D_ASSERT(peer_device, peer_req->i.size > 0);
2521                 D_ASSERT(peer_device, op == REQ_OP_WRITE_ZEROES);
2522                 D_ASSERT(peer_device, peer_req->pages == NULL);
2523         } else if (peer_req->pages == NULL) {
2524                 D_ASSERT(device, peer_req->i.size == 0);
2525                 D_ASSERT(device, dp_flags & DP_FLUSH);
2526         }
2527
2528         if (dp_flags & DP_MAY_SET_IN_SYNC)
2529                 peer_req->flags |= EE_MAY_SET_IN_SYNC;
2530
2531         spin_lock(&connection->epoch_lock);
2532         peer_req->epoch = connection->current_epoch;
2533         atomic_inc(&peer_req->epoch->epoch_size);
2534         atomic_inc(&peer_req->epoch->active);
2535         spin_unlock(&connection->epoch_lock);
2536
2537         rcu_read_lock();
2538         nc = rcu_dereference(peer_device->connection->net_conf);
2539         tp = nc->two_primaries;
2540         if (peer_device->connection->agreed_pro_version < 100) {
2541                 switch (nc->wire_protocol) {
2542                 case DRBD_PROT_C:
2543                         dp_flags |= DP_SEND_WRITE_ACK;
2544                         break;
2545                 case DRBD_PROT_B:
2546                         dp_flags |= DP_SEND_RECEIVE_ACK;
2547                         break;
2548                 }
2549         }
2550         rcu_read_unlock();
2551
2552         if (dp_flags & DP_SEND_WRITE_ACK) {
2553                 peer_req->flags |= EE_SEND_WRITE_ACK;
2554                 inc_unacked(device);
2555                 /* corresponding dec_unacked() in e_end_block()
2556                  * respective _drbd_clear_done_ee */
2557         }
2558
2559         if (dp_flags & DP_SEND_RECEIVE_ACK) {
2560                 /* I really don't like it that the receiver thread
2561                  * sends on the msock, but anyways */
2562                 drbd_send_ack(peer_device, P_RECV_ACK, peer_req);
2563         }
2564
2565         if (tp) {
2566                 /* two primaries implies protocol C */
2567                 D_ASSERT(device, dp_flags & DP_SEND_WRITE_ACK);
2568                 peer_req->flags |= EE_IN_INTERVAL_TREE;
2569                 err = wait_for_and_update_peer_seq(peer_device, peer_seq);
2570                 if (err)
2571                         goto out_interrupted;
2572                 spin_lock_irq(&device->resource->req_lock);
2573                 err = handle_write_conflicts(device, peer_req);
2574                 if (err) {
2575                         spin_unlock_irq(&device->resource->req_lock);
2576                         if (err == -ENOENT) {
2577                                 put_ldev(device);
2578                                 return 0;
2579                         }
2580                         goto out_interrupted;
2581                 }
2582         } else {
2583                 update_peer_seq(peer_device, peer_seq);
2584                 spin_lock_irq(&device->resource->req_lock);
2585         }
2586         /* TRIM and WRITE_SAME are processed synchronously,
2587          * we wait for all pending requests, respectively wait for
2588          * active_ee to become empty in drbd_submit_peer_request();
2589          * better not add ourselves here. */
2590         if ((peer_req->flags & (EE_IS_TRIM|EE_WRITE_SAME)) == 0)
2591                 list_add_tail(&peer_req->w.list, &device->active_ee);
2592         spin_unlock_irq(&device->resource->req_lock);
2593
2594         if (device->state.conn == C_SYNC_TARGET)
2595                 wait_event(device->ee_wait, !overlapping_resync_write(device, peer_req));
2596
2597         if (device->state.pdsk < D_INCONSISTENT) {
2598                 /* In case we have the only disk of the cluster, */
2599                 drbd_set_out_of_sync(device, peer_req->i.sector, peer_req->i.size);
2600                 peer_req->flags &= ~EE_MAY_SET_IN_SYNC;
2601                 drbd_al_begin_io(device, &peer_req->i);
2602                 peer_req->flags |= EE_CALL_AL_COMPLETE_IO;
2603         }
2604
2605         err = drbd_submit_peer_request(device, peer_req, op, op_flags,
2606                                        DRBD_FAULT_DT_WR);
2607         if (!err)
2608                 return 0;
2609
2610         /* don't care for the reason here */
2611         drbd_err(device, "submit failed, triggering re-connect\n");
2612         spin_lock_irq(&device->resource->req_lock);
2613         list_del(&peer_req->w.list);
2614         drbd_remove_epoch_entry_interval(device, peer_req);
2615         spin_unlock_irq(&device->resource->req_lock);
2616         if (peer_req->flags & EE_CALL_AL_COMPLETE_IO) {
2617                 peer_req->flags &= ~EE_CALL_AL_COMPLETE_IO;
2618                 drbd_al_complete_io(device, &peer_req->i);
2619         }
2620
2621 out_interrupted:
2622         drbd_may_finish_epoch(connection, peer_req->epoch, EV_PUT | EV_CLEANUP);
2623         put_ldev(device);
2624         drbd_free_peer_req(device, peer_req);
2625         return err;
2626 }
2627
2628 /* We may throttle resync, if the lower device seems to be busy,
2629  * and current sync rate is above c_min_rate.
2630  *
2631  * To decide whether or not the lower device is busy, we use a scheme similar
2632  * to MD RAID is_mddev_idle(): if the partition stats reveal "significant"
2633  * (more than 64 sectors) of activity we cannot account for with our own resync
2634  * activity, it obviously is "busy".
2635  *
2636  * The current sync rate used here uses only the most recent two step marks,
2637  * to have a short time average so we can react faster.
2638  */
2639 bool drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector,
2640                 bool throttle_if_app_is_waiting)
2641 {
2642         struct lc_element *tmp;
2643         bool throttle = drbd_rs_c_min_rate_throttle(device);
2644
2645         if (!throttle || throttle_if_app_is_waiting)
2646                 return throttle;
2647
2648         spin_lock_irq(&device->al_lock);
2649         tmp = lc_find(device->resync, BM_SECT_TO_EXT(sector));
2650         if (tmp) {
2651                 struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce);
2652                 if (test_bit(BME_PRIORITY, &bm_ext->flags))
2653                         throttle = false;
2654                 /* Do not slow down if app IO is already waiting for this extent,
2655                  * and our progress is necessary for application IO to complete. */
2656         }
2657         spin_unlock_irq(&device->al_lock);
2658
2659         return throttle;
2660 }
2661
2662 bool drbd_rs_c_min_rate_throttle(struct drbd_device *device)
2663 {
2664         struct gendisk *disk = device->ldev->backing_bdev->bd_contains->bd_disk;
2665         unsigned long db, dt, dbdt;
2666         unsigned int c_min_rate;
2667         int curr_events;
2668
2669         rcu_read_lock();
2670         c_min_rate = rcu_dereference(device->ldev->disk_conf)->c_min_rate;
2671         rcu_read_unlock();
2672
2673         /* feature disabled? */
2674         if (c_min_rate == 0)
2675                 return false;
2676
2677         curr_events = (int)part_stat_read_accum(&disk->part0, sectors) -
2678                         atomic_read(&device->rs_sect_ev);
2679
2680         if (atomic_read(&device->ap_actlog_cnt)
2681             || curr_events - device->rs_last_events > 64) {
2682                 unsigned long rs_left;
2683                 int i;
2684
2685                 device->rs_last_events = curr_events;
2686
2687                 /* sync speed average over the last 2*DRBD_SYNC_MARK_STEP,
2688                  * approx. */
2689                 i = (device->rs_last_mark + DRBD_SYNC_MARKS-1) % DRBD_SYNC_MARKS;
2690
2691                 if (device->state.conn == C_VERIFY_S || device->state.conn == C_VERIFY_T)
2692                         rs_left = device->ov_left;
2693                 else
2694                         rs_left = drbd_bm_total_weight(device) - device->rs_failed;
2695
2696                 dt = ((long)jiffies - (long)device->rs_mark_time[i]) / HZ;
2697                 if (!dt)
2698                         dt++;
2699                 db = device->rs_mark_left[i] - rs_left;
2700                 dbdt = Bit2KB(db/dt);
2701
2702                 if (dbdt > c_min_rate)
2703                         return true;
2704         }
2705         return false;
2706 }
2707
2708 static int receive_DataRequest(struct drbd_connection *connection, struct packet_info *pi)
2709 {
2710         struct drbd_peer_device *peer_device;
2711         struct drbd_device *device;
2712         sector_t sector;
2713         sector_t capacity;
2714         struct drbd_peer_request *peer_req;
2715         struct digest_info *di = NULL;
2716         int size, verb;
2717         unsigned int fault_type;
2718         struct p_block_req *p = pi->data;
2719
2720         peer_device = conn_peer_device(connection, pi->vnr);
2721         if (!peer_device)
2722                 return -EIO;
2723         device = peer_device->device;
2724         capacity = drbd_get_capacity(device->this_bdev);
2725
2726         sector = be64_to_cpu(p->sector);
2727         size   = be32_to_cpu(p->blksize);
2728
2729         if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
2730                 drbd_err(device, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
2731                                 (unsigned long long)sector, size);
2732                 return -EINVAL;
2733         }
2734         if (sector + (size>>9) > capacity) {
2735                 drbd_err(device, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
2736                                 (unsigned long long)sector, size);
2737                 return -EINVAL;
2738         }
2739
2740         if (!get_ldev_if_state(device, D_UP_TO_DATE)) {
2741                 verb = 1;
2742                 switch (pi->cmd) {
2743                 case P_DATA_REQUEST:
2744                         drbd_send_ack_rp(peer_device, P_NEG_DREPLY, p);
2745                         break;
2746                 case P_RS_THIN_REQ:
2747                 case P_RS_DATA_REQUEST:
2748                 case P_CSUM_RS_REQUEST:
2749                 case P_OV_REQUEST:
2750                         drbd_send_ack_rp(peer_device, P_NEG_RS_DREPLY , p);
2751                         break;
2752                 case P_OV_REPLY:
2753                         verb = 0;
2754                         dec_rs_pending(device);
2755                         drbd_send_ack_ex(peer_device, P_OV_RESULT, sector, size, ID_IN_SYNC);
2756                         break;
2757                 default:
2758                         BUG();
2759                 }
2760                 if (verb && __ratelimit(&drbd_ratelimit_state))
2761                         drbd_err(device, "Can not satisfy peer's read request, "
2762                             "no local data.\n");
2763
2764                 /* drain possibly payload */
2765                 return drbd_drain_block(peer_device, pi->size);
2766         }
2767
2768         /* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD
2769          * "criss-cross" setup, that might cause write-out on some other DRBD,
2770          * which in turn might block on the other node at this very place.  */
2771         peer_req = drbd_alloc_peer_req(peer_device, p->block_id, sector, size,
2772                         size, GFP_NOIO);
2773         if (!peer_req) {
2774                 put_ldev(device);
2775                 return -ENOMEM;
2776         }
2777
2778         switch (pi->cmd) {
2779         case P_DATA_REQUEST:
2780                 peer_req->w.cb = w_e_end_data_req;
2781                 fault_type = DRBD_FAULT_DT_RD;
2782                 /* application IO, don't drbd_rs_begin_io */
2783                 peer_req->flags |= EE_APPLICATION;
2784                 goto submit;
2785
2786         case P_RS_THIN_REQ:
2787                 /* If at some point in the future we have a smart way to
2788                    find out if this data block is completely deallocated,
2789                    then we would do something smarter here than reading
2790                    the block... */
2791                 peer_req->flags |= EE_RS_THIN_REQ;
2792                 /* fall through */
2793         case P_RS_DATA_REQUEST:
2794                 peer_req->w.cb = w_e_end_rsdata_req;
2795                 fault_type = DRBD_FAULT_RS_RD;
2796                 /* used in the sector offset progress display */
2797                 device->bm_resync_fo = BM_SECT_TO_BIT(sector);
2798                 break;
2799
2800         case P_OV_REPLY:
2801         case P_CSUM_RS_REQUEST:
2802                 fault_type = DRBD_FAULT_RS_RD;
2803                 di = kmalloc(sizeof(*di) + pi->size, GFP_NOIO);
2804                 if (!di)
2805                         goto out_free_e;
2806
2807                 di->digest_size = pi->size;
2808                 di->digest = (((char *)di)+sizeof(struct digest_info));
2809
2810                 peer_req->digest = di;
2811                 peer_req->flags |= EE_HAS_DIGEST;
2812
2813                 if (drbd_recv_all(peer_device->connection, di->digest, pi->size))
2814                         goto out_free_e;
2815
2816                 if (pi->cmd == P_CSUM_RS_REQUEST) {
2817                         D_ASSERT(device, peer_device->connection->agreed_pro_version >= 89);
2818                         peer_req->w.cb = w_e_end_csum_rs_req;
2819                         /* used in the sector offset progress display */
2820                         device->bm_resync_fo = BM_SECT_TO_BIT(sector);
2821                         /* remember to report stats in drbd_resync_finished */
2822                         device->use_csums = true;
2823                 } else if (pi->cmd == P_OV_REPLY) {
2824                         /* track progress, we may need to throttle */
2825                         atomic_add(size >> 9, &device->rs_sect_in);
2826                         peer_req->w.cb = w_e_end_ov_reply;
2827                         dec_rs_pending(device);
2828                         /* drbd_rs_begin_io done when we sent this request,
2829                          * but accounting still needs to be done. */
2830                         goto submit_for_resync;
2831                 }
2832                 break;
2833
2834         case P_OV_REQUEST:
2835                 if (device->ov_start_sector == ~(sector_t)0 &&
2836                     peer_device->connection->agreed_pro_version >= 90) {
2837                         unsigned long now = jiffies;
2838                         int i;
2839                         device->ov_start_sector = sector;
2840                         device->ov_position = sector;
2841                         device->ov_left = drbd_bm_bits(device) - BM_SECT_TO_BIT(sector);
2842                         device->rs_total = device->ov_left;
2843                         for (i = 0; i < DRBD_SYNC_MARKS; i++) {
2844                                 device->rs_mark_left[i] = device->ov_left;
2845                                 device->rs_mark_time[i] = now;
2846                         }
2847                         drbd_info(device, "Online Verify start sector: %llu\n",
2848                                         (unsigned long long)sector);
2849                 }
2850                 peer_req->w.cb = w_e_end_ov_req;
2851                 fault_type = DRBD_FAULT_RS_RD;
2852                 break;
2853
2854         default:
2855                 BUG();
2856         }
2857
2858         /* Throttle, drbd_rs_begin_io and submit should become asynchronous
2859          * wrt the receiver, but it is not as straightforward as it may seem.
2860          * Various places in the resync start and stop logic assume resync
2861          * requests are processed in order, requeuing this on the worker thread
2862          * introduces a bunch of new code for synchronization between threads.
2863          *
2864          * Unlimited throttling before drbd_rs_begin_io may stall the resync
2865          * "forever", throttling after drbd_rs_begin_io will lock that extent
2866          * for application writes for the same time.  For now, just throttle
2867          * here, where the rest of the code expects the receiver to sleep for
2868          * a while, anyways.
2869          */
2870
2871         /* Throttle before drbd_rs_begin_io, as that locks out application IO;
2872          * this defers syncer requests for some time, before letting at least
2873          * on request through.  The resync controller on the receiving side
2874          * will adapt to the incoming rate accordingly.
2875          *
2876          * We cannot throttle here if remote is Primary/SyncTarget:
2877          * we would also throttle its application reads.
2878          * In that case, throttling is done on the SyncTarget only.
2879          */
2880
2881         /* Even though this may be a resync request, we do add to "read_ee";
2882          * "sync_ee" is only used for resync WRITEs.
2883          * Add to list early, so debugfs can find this request
2884          * even if we have to sleep below. */
2885         spin_lock_irq(&device->resource->req_lock);
2886         list_add_tail(&peer_req->w.list, &device->read_ee);
2887         spin_unlock_irq(&device->resource->req_lock);
2888
2889         update_receiver_timing_details(connection, drbd_rs_should_slow_down);
2890         if (device->state.peer != R_PRIMARY
2891         && drbd_rs_should_slow_down(device, sector, false))
2892                 schedule_timeout_uninterruptible(HZ/10);
2893         update_receiver_timing_details(connection, drbd_rs_begin_io);
2894         if (drbd_rs_begin_io(device, sector))
2895                 goto out_free_e;
2896
2897 submit_for_resync:
2898         atomic_add(size >> 9, &device->rs_sect_ev);
2899
2900 submit:
2901         update_receiver_timing_details(connection, drbd_submit_peer_request);
2902         inc_unacked(device);
2903         if (drbd_submit_peer_request(device, peer_req, REQ_OP_READ, 0,
2904                                      fault_type) == 0)
2905                 return 0;
2906
2907         /* don't care for the reason here */
2908         drbd_err(device, "submit failed, triggering re-connect\n");
2909
2910 out_free_e:
2911         spin_lock_irq(&device->resource->req_lock);
2912         list_del(&peer_req->w.list);
2913         spin_unlock_irq(&device->resource->req_lock);
2914         /* no drbd_rs_complete_io(), we are dropping the connection anyways */
2915
2916         put_ldev(device);
2917         drbd_free_peer_req(device, peer_req);
2918         return -EIO;
2919 }
2920
2921 /**
2922  * drbd_asb_recover_0p  -  Recover after split-brain with no remaining primaries
2923  */
2924 static int drbd_asb_recover_0p(struct drbd_peer_device *peer_device) __must_hold(local)
2925 {
2926         struct drbd_device *device = peer_device->device;
2927         int self, peer, rv = -100;
2928         unsigned long ch_self, ch_peer;
2929         enum drbd_after_sb_p after_sb_0p;
2930
2931         self = device->ldev->md.uuid[UI_BITMAP] & 1;
2932         peer = device->p_uuid[UI_BITMAP] & 1;
2933
2934         ch_peer = device->p_uuid[UI_SIZE];
2935         ch_self = device->comm_bm_set;
2936
2937         rcu_read_lock();
2938         after_sb_0p = rcu_dereference(peer_device->connection->net_conf)->after_sb_0p;
2939         rcu_read_unlock();
2940         switch (after_sb_0p) {
2941         case ASB_CONSENSUS:
2942         case ASB_DISCARD_SECONDARY:
2943         case ASB_CALL_HELPER:
2944         case ASB_VIOLENTLY:
2945                 drbd_err(device, "Configuration error.\n");
2946                 break;
2947         case ASB_DISCONNECT:
2948                 break;
2949         case ASB_DISCARD_YOUNGER_PRI:
2950                 if (self == 0 && peer == 1) {
2951                         rv = -1;
2952                         break;
2953                 }
2954                 if (self == 1 && peer == 0) {
2955                         rv =  1;
2956                         break;
2957                 }
2958                 /* Else fall through to one of the other strategies... */
2959         case ASB_DISCARD_OLDER_PRI:
2960                 if (self == 0 && peer == 1) {
2961                         rv = 1;
2962                         break;
2963                 }
2964                 if (self == 1 && peer == 0) {
2965                         rv = -1;
2966                         break;
2967                 }
2968                 /* Else fall through to one of the other strategies... */
2969                 drbd_warn(device, "Discard younger/older primary did not find a decision\n"
2970                      "Using discard-least-changes instead\n");
2971                 /* fall through */
2972         case ASB_DISCARD_ZERO_CHG:
2973                 if (ch_peer == 0 && ch_self == 0) {
2974                         rv = test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags)
2975                                 ? -1 : 1;
2976                         break;
2977                 } else {
2978                         if (ch_peer == 0) { rv =  1; break; }
2979                         if (ch_self == 0) { rv = -1; break; }
2980                 }
2981                 if (after_sb_0p == ASB_DISCARD_ZERO_CHG)
2982                         break;
2983                 /* else: fall through */
2984         case ASB_DISCARD_LEAST_CHG:
2985                 if      (ch_self < ch_peer)
2986                         rv = -1;
2987                 else if (ch_self > ch_peer)
2988                         rv =  1;
2989                 else /* ( ch_self == ch_peer ) */
2990                      /* Well, then use something else. */
2991                         rv = test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags)
2992                                 ? -1 : 1;
2993                 break;
2994         case ASB_DISCARD_LOCAL:
2995                 rv = -1;
2996                 break;
2997         case ASB_DISCARD_REMOTE:
2998                 rv =  1;
2999         }
3000
3001         return rv;
3002 }
3003
3004 /**
3005  * drbd_asb_recover_1p  -  Recover after split-brain with one remaining primary
3006  */
3007 static int drbd_asb_recover_1p(struct drbd_peer_device *peer_device) __must_hold(local)
3008 {
3009         struct drbd_device *device = peer_device->device;
3010         int hg, rv = -100;
3011         enum drbd_after_sb_p after_sb_1p;
3012
3013         rcu_read_lock();
3014         after_sb_1p = rcu_dereference(peer_device->connection->net_conf)->after_sb_1p;
3015         rcu_read_unlock();
3016         switch (after_sb_1p) {
3017         case ASB_DISCARD_YOUNGER_PRI:
3018         case ASB_DISCARD_OLDER_PRI:
3019         case ASB_DISCARD_LEAST_CHG:
3020         case ASB_DISCARD_LOCAL:
3021         case ASB_DISCARD_REMOTE:
3022         case ASB_DISCARD_ZERO_CHG:
3023                 drbd_err(device, "Configuration error.\n");
3024                 break;
3025         case ASB_DISCONNECT:
3026                 break;
3027         case ASB_CONSENSUS:
3028                 hg = drbd_asb_recover_0p(peer_device);
3029                 if (hg == -1 && device->state.role == R_SECONDARY)
3030                         rv = hg;
3031                 if (hg == 1  && device->state.role == R_PRIMARY)
3032                         rv = hg;
3033                 break;
3034         case ASB_VIOLENTLY:
3035                 rv = drbd_asb_recover_0p(peer_device);
3036                 break;
3037         case ASB_DISCARD_SECONDARY:
3038                 return device->state.role == R_PRIMARY ? 1 : -1;
3039         case ASB_CALL_HELPER:
3040                 hg = drbd_asb_recover_0p(peer_device);
3041                 if (hg == -1 && device->state.role == R_PRIMARY) {
3042                         enum drbd_state_rv rv2;
3043
3044                          /* drbd_change_state() does not sleep while in SS_IN_TRANSIENT_STATE,
3045                           * we might be here in C_WF_REPORT_PARAMS which is transient.
3046                           * we do not need to wait for the after state change work either. */
3047                         rv2 = drbd_change_state(device, CS_VERBOSE, NS(role, R_SECONDARY));
3048                         if (rv2 != SS_SUCCESS) {
3049                                 drbd_khelper(device, "pri-lost-after-sb");
3050                         } else {
3051                                 drbd_warn(device, "Successfully gave up primary role.\n");
3052                                 rv = hg;
3053                         }
3054                 } else
3055                         rv = hg;
3056         }
3057
3058         return rv;
3059 }
3060
3061 /**
3062  * drbd_asb_recover_2p  -  Recover after split-brain with two remaining primaries
3063  */
3064 static int drbd_asb_recover_2p(struct drbd_peer_device *peer_device) __must_hold(local)
3065 {
3066         struct drbd_device *device = peer_device->device;
3067         int hg, rv = -100;
3068         enum drbd_after_sb_p after_sb_2p;
3069
3070         rcu_read_lock();
3071         after_sb_2p = rcu_dereference(peer_device->connection->net_conf)->after_sb_2p;
3072         rcu_read_unlock();
3073         switch (after_sb_2p) {
3074         case ASB_DISCARD_YOUNGER_PRI:
3075         case ASB_DISCARD_OLDER_PRI:
3076         case ASB_DISCARD_LEAST_CHG:
3077         case ASB_DISCARD_LOCAL:
3078         case ASB_DISCARD_REMOTE:
3079         case ASB_CONSENSUS:
3080         case ASB_DISCARD_SECONDARY:
3081         case ASB_DISCARD_ZERO_CHG:
3082                 drbd_err(device, "Configuration error.\n");
3083                 break;
3084         case ASB_VIOLENTLY:
3085                 rv = drbd_asb_recover_0p(peer_device);
3086                 break;
3087         case ASB_DISCONNECT:
3088                 break;
3089         case ASB_CALL_HELPER:
3090                 hg = drbd_asb_recover_0p(peer_device);
3091                 if (hg == -1) {
3092                         enum drbd_state_rv rv2;
3093
3094                          /* drbd_change_state() does not sleep while in SS_IN_TRANSIENT_STATE,
3095                           * we might be here in C_WF_REPORT_PARAMS which is transient.
3096                           * we do not need to wait for the after state change work either. */
3097                         rv2 = drbd_change_state(device, CS_VERBOSE, NS(role, R_SECONDARY));
3098                         if (rv2 != SS_SUCCESS) {
3099                                 drbd_khelper(device, "pri-lost-after-sb");
3100                         } else {
3101                                 drbd_warn(device, "Successfully gave up primary role.\n");
3102                                 rv = hg;
3103                         }
3104                 } else
3105                         rv = hg;
3106         }
3107
3108         return rv;
3109 }
3110
3111 static void drbd_uuid_dump(struct drbd_device *device, char *text, u64 *uuid,
3112                            u64 bits, u64 flags)
3113 {
3114         if (!uuid) {
3115                 drbd_info(device, "%s uuid info vanished while I was looking!\n", text);
3116                 return;
3117         }
3118         drbd_info(device, "%s %016llX:%016llX:%016llX:%016llX bits:%llu flags:%llX\n",
3119              text,
3120              (unsigned long long)uuid[UI_CURRENT],
3121              (unsigned long long)uuid[UI_BITMAP],
3122              (unsigned long long)uuid[UI_HISTORY_START],
3123              (unsigned long long)uuid[UI_HISTORY_END],
3124              (unsigned long long)bits,
3125              (unsigned long long)flags);
3126 }
3127
3128 /*
3129   100   after split brain try auto recover
3130     2   C_SYNC_SOURCE set BitMap
3131     1   C_SYNC_SOURCE use BitMap
3132     0   no Sync
3133    -1   C_SYNC_TARGET use BitMap
3134    -2   C_SYNC_TARGET set BitMap
3135  -100   after split brain, disconnect
3136 -1000   unrelated data
3137 -1091   requires proto 91
3138 -1096   requires proto 96
3139  */
3140
3141 static int drbd_uuid_compare(struct drbd_device *const device, enum drbd_role const peer_role, int *rule_nr) __must_hold(local)
3142 {
3143         struct drbd_peer_device *const peer_device = first_peer_device(device);
3144         struct drbd_connection *const connection = peer_device ? peer_device->connection : NULL;
3145         u64 self, peer;
3146         int i, j;
3147
3148         self = device->ldev->md.uuid[UI_CURRENT] & ~((u64)1);
3149         peer = device->p_uuid[UI_CURRENT] & ~((u64)1);
3150
3151         *rule_nr = 10;
3152         if (self == UUID_JUST_CREATED && peer == UUID_JUST_CREATED)
3153                 return 0;
3154
3155         *rule_nr = 20;
3156         if ((self == UUID_JUST_CREATED || self == (u64)0) &&
3157              peer != UUID_JUST_CREATED)
3158                 return -2;
3159
3160         *rule_nr = 30;
3161         if (self != UUID_JUST_CREATED &&
3162             (peer == UUID_JUST_CREATED || peer == (u64)0))
3163                 return 2;
3164
3165         if (self == peer) {
3166                 int rct, dc; /* roles at crash time */
3167
3168                 if (device->p_uuid[UI_BITMAP] == (u64)0 && device->ldev->md.uuid[UI_BITMAP] != (u64)0) {
3169
3170                         if (connection->agreed_pro_version < 91)
3171                                 return -1091;
3172
3173                         if ((device->ldev->md.uuid[UI_BITMAP] & ~((u64)1)) == (device->p_uuid[UI_HISTORY_START] & ~((u64)1)) &&
3174                             (device->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (device->p_uuid[UI_HISTORY_START + 1] & ~((u64)1))) {
3175                                 drbd_info(device, "was SyncSource, missed the resync finished event, corrected myself:\n");
3176                                 drbd_uuid_move_history(device);
3177                                 device->ldev->md.uuid[UI_HISTORY_START] = device->ldev->md.uuid[UI_BITMAP];
3178                                 device->ldev->md.uuid[UI_BITMAP] = 0;
3179
3180                                 drbd_uuid_dump(device, "self", device->ldev->md.uuid,
3181                                                device->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(device) : 0, 0);
3182                                 *rule_nr = 34;
3183                         } else {
3184                                 drbd_info(device, "was SyncSource (peer failed to write sync_uuid)\n");
3185                                 *rule_nr = 36;
3186                         }
3187
3188                         return 1;
3189                 }
3190
3191                 if (device->ldev->md.uuid[UI_BITMAP] == (u64)0 && device->p_uuid[UI_BITMAP] != (u64)0) {
3192
3193                         if (connection->agreed_pro_version < 91)
3194                                 return -1091;
3195
3196                         if ((device->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (device->p_uuid[UI_BITMAP] & ~((u64)1)) &&
3197                             (device->ldev->md.uuid[UI_HISTORY_START + 1] & ~((u64)1)) == (device->p_uuid[UI_HISTORY_START] & ~((u64)1))) {
3198                                 drbd_info(device, "was SyncTarget, peer missed the resync finished event, corrected peer:\n");
3199
3200                                 device->p_uuid[UI_HISTORY_START + 1] = device->p_uuid[UI_HISTORY_START];
3201                                 device->p_uuid[UI_HISTORY_START] = device->p_uuid[UI_BITMAP];
3202                                 device->p_uuid[UI_BITMAP] = 0UL;
3203
3204                                 drbd_uuid_dump(device, "peer", device->p_uuid, device->p_uuid[UI_SIZE], device->p_uuid[UI_FLAGS]);
3205                                 *rule_nr = 35;
3206                         } else {
3207                                 drbd_info(device, "was SyncTarget (failed to write sync_uuid)\n");
3208                                 *rule_nr = 37;
3209                         }
3210
3211                         return -1;
3212                 }
3213
3214                 /* Common power [off|failure] */
3215                 rct = (test_bit(CRASHED_PRIMARY, &device->flags) ? 1 : 0) +
3216                         (device->p_uuid[UI_FLAGS] & 2);
3217                 /* lowest bit is set when we were primary,
3218                  * next bit (weight 2) is set when peer was primary */
3219                 *rule_nr = 40;
3220
3221                 /* Neither has the "crashed primary" flag set,
3222                  * only a replication link hickup. */
3223                 if (rct == 0)
3224                         return 0;
3225
3226                 /* Current UUID equal and no bitmap uuid; does not necessarily
3227                  * mean this was a "simultaneous hard crash", maybe IO was
3228                  * frozen, so no UUID-bump happened.
3229                  * This is a protocol change, overload DRBD_FF_WSAME as flag
3230                  * for "new-enough" peer DRBD version. */
3231                 if (device->state.role == R_PRIMARY || peer_role == R_PRIMARY) {
3232                         *rule_nr = 41;
3233                         if (!(connection->agreed_features & DRBD_FF_WSAME)) {
3234                                 drbd_warn(peer_device, "Equivalent unrotated UUIDs, but current primary present.\n");
3235                                 return -(0x10000 | PRO_VERSION_MAX | (DRBD_FF_WSAME << 8));
3236                         }
3237                         if (device->state.role == R_PRIMARY && peer_role == R_PRIMARY) {
3238                                 /* At least one has the "crashed primary" bit set,
3239                                  * both are primary now, but neither has rotated its UUIDs?
3240                                  * "Can not happen." */
3241                                 drbd_err(peer_device, "Equivalent unrotated UUIDs, but both are primary. Can not resolve this.\n");
3242                                 return -100;
3243                         }
3244                         if (device->state.role == R_PRIMARY)
3245                                 return 1;
3246                         return -1;
3247                 }
3248
3249                 /* Both are secondary.
3250                  * Really looks like recovery from simultaneous hard crash.
3251                  * Check which had been primary before, and arbitrate. */
3252                 switch (rct) {
3253                 case 0: /* !self_pri && !peer_pri */ return 0; /* already handled */
3254                 case 1: /*  self_pri && !peer_pri */ return 1;
3255                 case 2: /* !self_pri &&  peer_pri */ return -1;
3256                 case 3: /*  self_pri &&  peer_pri */
3257                         dc = test_bit(RESOLVE_CONFLICTS, &connection->flags);
3258                         return dc ? -1 : 1;
3259                 }
3260         }
3261
3262         *rule_nr = 50;
3263         peer = device->p_uuid[UI_BITMAP] & ~((u64)1);
3264         if (self == peer)
3265                 return -1;
3266
3267         *rule_nr = 51;
3268         peer = device->p_uuid[UI_HISTORY_START] & ~((u64)1);
3269         if (self == peer) {
3270                 if (connection->agreed_pro_version < 96 ?
3271                     (device->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) ==
3272                     (device->p_uuid[UI_HISTORY_START + 1] & ~((u64)1)) :
3273                     peer + UUID_NEW_BM_OFFSET == (device->p_uuid[UI_BITMAP] & ~((u64)1))) {
3274                         /* The last P_SYNC_UUID did not get though. Undo the last start of
3275                            resync as sync source modifications of the peer's UUIDs. */
3276
3277                         if (connection->agreed_pro_version < 91)
3278                                 return -1091;
3279
3280                         device->p_uuid[UI_BITMAP] = device->p_uuid[UI_HISTORY_START];
3281                         device->p_uuid[UI_HISTORY_START] = device->p_uuid[UI_HISTORY_START + 1];
3282
3283                         drbd_info(device, "Lost last syncUUID packet, corrected:\n");
3284                         drbd_uuid_dump(device, "peer", device->p_uuid, device->p_uuid[UI_SIZE], device->p_uuid[UI_FLAGS]);
3285
3286                         return -1;
3287                 }
3288         }
3289
3290         *rule_nr = 60;
3291         self = device->ldev->md.uuid[UI_CURRENT] & ~((u64)1);
3292         for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) {
3293                 peer = device->p_uuid[i] & ~((u64)1);
3294                 if (self == peer)
3295                         return -2;
3296         }
3297
3298         *rule_nr = 70;
3299         self = device->ldev->md.uuid[UI_BITMAP] & ~((u64)1);
3300         peer = device->p_uuid[UI_CURRENT] & ~((u64)1);
3301         if (self == peer)
3302                 return 1;
3303
3304         *rule_nr = 71;
3305         self = device->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1);
3306         if (self == peer) {
3307                 if (connection->agreed_pro_version < 96 ?
3308                     (device->ldev->md.uuid[UI_HISTORY_START + 1] & ~((u64)1)) ==
3309                     (device->p_uuid[UI_HISTORY_START] & ~((u64)1)) :
3310                     self + UUID_NEW_BM_OFFSET == (device->ldev->md.uuid[UI_BITMAP] & ~((u64)1))) {
3311                         /* The last P_SYNC_UUID did not get though. Undo the last start of
3312                            resync as sync source modifications of our UUIDs. */
3313
3314                         if (connection->agreed_pro_version < 91)
3315                                 return -1091;
3316
3317                         __drbd_uuid_set(device, UI_BITMAP, device->ldev->md.uuid[UI_HISTORY_START]);
3318                         __drbd_uuid_set(device, UI_HISTORY_START, device->ldev->md.uuid[UI_HISTORY_START + 1]);
3319
3320                         drbd_info(device, "Last syncUUID did not get through, corrected:\n");
3321                         drbd_uuid_dump(device, "self", device->ldev->md.uuid,
3322                                        device->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(device) : 0, 0);
3323
3324                         return 1;
3325                 }
3326         }
3327
3328
3329         *rule_nr = 80;
3330         peer = device->p_uuid[UI_CURRENT] & ~((u64)1);
3331         for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) {
3332                 self = device->ldev->md.uuid[i] & ~((u64)1);
3333                 if (self == peer)
3334                         return 2;
3335         }
3336
3337         *rule_nr = 90;
3338         self = device->ldev->md.uuid[UI_BITMAP] & ~((u64)1);
3339         peer = device->p_uuid[UI_BITMAP] & ~((u64)1);
3340         if (self == peer && self != ((u64)0))
3341                 return 100;
3342
3343         *rule_nr = 100;
3344         for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) {
3345                 self = device->ldev->md.uuid[i] & ~((u64)1);
3346                 for (j = UI_HISTORY_START; j <= UI_HISTORY_END; j++) {
3347                         peer = device->p_uuid[j] & ~((u64)1);
3348                         if (self == peer)
3349                                 return -100;
3350                 }
3351         }
3352
3353         return -1000;
3354 }
3355
3356 /* drbd_sync_handshake() returns the new conn state on success, or
3357    CONN_MASK (-1) on failure.
3358  */
3359 static enum drbd_conns drbd_sync_handshake(struct drbd_peer_device *peer_device,
3360                                            enum drbd_role peer_role,
3361                                            enum drbd_disk_state peer_disk) __must_hold(local)
3362 {
3363         struct drbd_device *device = peer_device->device;
3364         enum drbd_conns rv = C_MASK;
3365         enum drbd_disk_state mydisk;
3366         struct net_conf *nc;
3367         int hg, rule_nr, rr_conflict, tentative;
3368
3369         mydisk = device->state.disk;
3370         if (mydisk == D_NEGOTIATING)
3371                 mydisk = device->new_state_tmp.disk;
3372
3373         drbd_info(device, "drbd_sync_handshake:\n");
3374
3375         spin_lock_irq(&device->ldev->md.uuid_lock);
3376         drbd_uuid_dump(device, "self", device->ldev->md.uuid, device->comm_bm_set, 0);
3377         drbd_uuid_dump(device, "peer", device->p_uuid,
3378                        device->p_uuid[UI_SIZE], device->p_uuid[UI_FLAGS]);
3379
3380         hg = drbd_uuid_compare(device, peer_role, &rule_nr);
3381         spin_unlock_irq(&device->ldev->md.uuid_lock);
3382
3383         drbd_info(device, "uuid_compare()=%d by rule %d\n", hg, rule_nr);
3384
3385         if (hg == -1000) {
3386                 drbd_alert(device, "Unrelated data, aborting!\n");
3387                 return C_MASK;
3388         }
3389         if (hg < -0x10000) {
3390                 int proto, fflags;
3391                 hg = -hg;
3392                 proto = hg & 0xff;
3393                 fflags = (hg >> 8) & 0xff;
3394                 drbd_alert(device, "To resolve this both sides have to support at least protocol %d and feature flags 0x%x\n",
3395                                         proto, fflags);
3396                 return C_MASK;
3397         }
3398         if (hg < -1000) {
3399                 drbd_alert(device, "To resolve this both sides have to support at least protocol %d\n", -hg - 1000);
3400                 return C_MASK;
3401         }
3402
3403         if    ((mydisk == D_INCONSISTENT && peer_disk > D_INCONSISTENT) ||
3404             (peer_disk == D_INCONSISTENT && mydisk    > D_INCONSISTENT)) {
3405                 int f = (hg == -100) || abs(hg) == 2;
3406                 hg = mydisk > D_INCONSISTENT ? 1 : -1;
3407                 if (f)
3408                         hg = hg*2;
3409                 drbd_info(device, "Becoming sync %s due to disk states.\n",
3410                      hg > 0 ? "source" : "target");
3411         }
3412
3413         if (abs(hg) == 100)
3414                 drbd_khelper(device, "initial-split-brain");
3415
3416         rcu_read_lock();
3417         nc = rcu_dereference(peer_device->connection->net_conf);
3418
3419         if (hg == 100 || (hg == -100 && nc->always_asbp)) {
3420                 int pcount = (device->state.role == R_PRIMARY)
3421                            + (peer_role == R_PRIMARY);
3422                 int forced = (hg == -100);
3423
3424                 switch (pcount) {
3425                 case 0:
3426                         hg = drbd_asb_recover_0p(peer_device);
3427                         break;
3428                 case 1:
3429                         hg = drbd_asb_recover_1p(peer_device);
3430                         break;
3431                 case 2:
3432                         hg = drbd_asb_recover_2p(peer_device);
3433                         break;
3434                 }
3435                 if (abs(hg) < 100) {
3436                         drbd_warn(device, "Split-Brain detected, %d primaries, "
3437                              "automatically solved. Sync from %s node\n",
3438                              pcount, (hg < 0) ? "peer" : "this");
3439                         if (forced) {
3440                                 drbd_warn(device, "Doing a full sync, since"
3441                                      " UUIDs where ambiguous.\n");
3442                                 hg = hg*2;
3443                         }
3444                 }
3445         }
3446
3447         if (hg == -100) {
3448                 if (test_bit(DISCARD_MY_DATA, &device->flags) && !(device->p_uuid[UI_FLAGS]&1))
3449                         hg = -1;
3450                 if (!test_bit(DISCARD_MY_DATA, &device->flags) && (device->p_uuid[UI_FLAGS]&1))
3451                         hg = 1;
3452
3453                 if (abs(hg) < 100)
3454                         drbd_warn(device, "Split-Brain detected, manually solved. "
3455                              "Sync from %s node\n",
3456                              (hg < 0) ? "peer" : "this");
3457         }
3458         rr_conflict = nc->rr_conflict;
3459         tentative = nc->tentative;
3460         rcu_read_unlock();
3461
3462         if (hg == -100) {
3463                 /* FIXME this log message is not correct if we end up here
3464                  * after an attempted attach on a diskless node.
3465                  * We just refuse to attach -- well, we drop the "connection"
3466                  * to that disk, in a way... */
3467                 drbd_alert(device, "Split-Brain detected but unresolved, dropping connection!\n");
3468                 drbd_khelper(device, "split-brain");
3469                 return C_MASK;
3470         }
3471
3472         if (hg > 0 && mydisk <= D_INCONSISTENT) {
3473                 drbd_err(device, "I shall become SyncSource, but I am inconsistent!\n");
3474                 return C_MASK;
3475         }
3476
3477         if (hg < 0 && /* by intention we do not use mydisk here. */
3478             device->state.role == R_PRIMARY && device->state.disk >= D_CONSISTENT) {
3479                 switch (rr_conflict) {
3480                 case ASB_CALL_HELPER:
3481                         drbd_khelper(device, "pri-lost");
3482                         /* fall through */
3483                 case ASB_DISCONNECT:
3484                         drbd_err(device, "I shall become SyncTarget, but I am primary!\n");
3485                         return C_MASK;
3486                 case ASB_VIOLENTLY:
3487                         drbd_warn(device, "Becoming SyncTarget, violating the stable-data"
3488                              "assumption\n");
3489                 }
3490         }
3491
3492         if (tentative || test_bit(CONN_DRY_RUN, &peer_device->connection->flags)) {
3493                 if (hg == 0)
3494                         drbd_info(device, "dry-run connect: No resync, would become Connected immediately.\n");
3495                 else
3496                         drbd_info(device, "dry-run connect: Would become %s, doing a %s resync.",
3497                                  drbd_conn_str(hg > 0 ? C_SYNC_SOURCE : C_SYNC_TARGET),
3498                                  abs(hg) >= 2 ? "full" : "bit-map based");
3499                 return C_MASK;
3500         }
3501
3502         if (abs(hg) >= 2) {
3503                 drbd_info(device, "Writing the whole bitmap, full sync required after drbd_sync_handshake.\n");
3504                 if (drbd_bitmap_io(device, &drbd_bmio_set_n_write, "set_n_write from sync_handshake",
3505                                         BM_LOCKED_SET_ALLOWED))
3506                         return C_MASK;
3507         }
3508
3509         if (hg > 0) { /* become sync source. */
3510                 rv = C_WF_BITMAP_S;
3511         } else if (hg < 0) { /* become sync target */
3512                 rv = C_WF_BITMAP_T;
3513         } else {
3514                 rv = C_CONNECTED;
3515                 if (drbd_bm_total_weight(device)) {
3516                         drbd_info(device, "No resync, but %lu bits in bitmap!\n",
3517                              drbd_bm_total_weight(device));
3518                 }
3519         }
3520
3521         return rv;
3522 }
3523
3524 static enum drbd_after_sb_p convert_after_sb(enum drbd_after_sb_p peer)
3525 {
3526         /* ASB_DISCARD_REMOTE - ASB_DISCARD_LOCAL is valid */
3527         if (peer == ASB_DISCARD_REMOTE)
3528                 return ASB_DISCARD_LOCAL;
3529
3530         /* any other things with ASB_DISCARD_REMOTE or ASB_DISCARD_LOCAL are invalid */
3531         if (peer == ASB_DISCARD_LOCAL)
3532                 return ASB_DISCARD_REMOTE;
3533
3534         /* everything else is valid if they are equal on both sides. */
3535         return peer;
3536 }
3537
3538 static int receive_protocol(struct drbd_connection *connection, struct packet_info *pi)
3539 {
3540         struct p_protocol *p = pi->data;
3541         enum drbd_after_sb_p p_after_sb_0p, p_after_sb_1p, p_after_sb_2p;
3542         int p_proto, p_discard_my_data, p_two_primaries, cf;
3543         struct net_conf *nc, *old_net_conf, *new_net_conf = NULL;
3544         char integrity_alg[SHARED_SECRET_MAX] = "";
3545         struct crypto_ahash *peer_integrity_tfm = NULL;
3546         void *int_dig_in = NULL, *int_dig_vv = NULL;
3547
3548         p_proto         = be32_to_cpu(p->protocol);
3549         p_after_sb_0p   = be32_to_cpu(p->after_sb_0p);
3550         p_after_sb_1p   = be32_to_cpu(p->after_sb_1p);
3551         p_after_sb_2p   = be32_to_cpu(p->after_sb_2p);
3552         p_two_primaries = be32_to_cpu(p->two_primaries);
3553         cf              = be32_to_cpu(p->conn_flags);
3554         p_discard_my_data = cf & CF_DISCARD_MY_DATA;
3555
3556         if (connection->agreed_pro_version >= 87) {
3557                 int err;
3558
3559                 if (pi->size > sizeof(integrity_alg))
3560                         return -EIO;
3561                 err = drbd_recv_all(connection, integrity_alg, pi->size);
3562                 if (err)
3563                         return err;
3564                 integrity_alg[SHARED_SECRET_MAX - 1] = 0;
3565         }
3566
3567         if (pi->cmd != P_PROTOCOL_UPDATE) {
3568                 clear_bit(CONN_DRY_RUN, &connection->flags);
3569
3570                 if (cf & CF_DRY_RUN)
3571                         set_bit(CONN_DRY_RUN, &connection->flags);
3572
3573                 rcu_read_lock();
3574                 nc = rcu_dereference(connection->net_conf);
3575
3576                 if (p_proto != nc->wire_protocol) {
3577                         drbd_err(connection, "incompatible %s settings\n", "protocol");
3578                         goto disconnect_rcu_unlock;
3579                 }
3580
3581                 if (convert_after_sb(p_after_sb_0p) != nc->after_sb_0p) {
3582                         drbd_err(connection, "incompatible %s settings\n", "after-sb-0pri");
3583                         goto disconnect_rcu_unlock;
3584                 }
3585
3586                 if (convert_after_sb(p_after_sb_1p) != nc->after_sb_1p) {
3587                         drbd_err(connection, "incompatible %s settings\n", "after-sb-1pri");
3588                         goto disconnect_rcu_unlock;
3589                 }
3590
3591                 if (convert_after_sb(p_after_sb_2p) != nc->after_sb_2p) {
3592                         drbd_err(connection, "incompatible %s settings\n", "after-sb-2pri");
3593                         goto disconnect_rcu_unlock;
3594                 }
3595
3596                 if (p_discard_my_data && nc->discard_my_data) {
3597                         drbd_err(connection, "incompatible %s settings\n", "discard-my-data");
3598                         goto disconnect_rcu_unlock;
3599                 }
3600
3601                 if (p_two_primaries != nc->two_primaries) {
3602                         drbd_err(connection, "incompatible %s settings\n", "allow-two-primaries");
3603                         goto disconnect_rcu_unlock;
3604                 }
3605
3606                 if (strcmp(integrity_alg, nc->integrity_alg)) {
3607                         drbd_err(connection, "incompatible %s settings\n", "data-integrity-alg");
3608                         goto disconnect_rcu_unlock;
3609                 }
3610
3611                 rcu_read_unlock();
3612         }
3613
3614         if (integrity_alg[0]) {
3615                 int hash_size;
3616
3617                 /*
3618                  * We can only change the peer data integrity algorithm
3619                  * here.  Changing our own data integrity algorithm
3620                  * requires that we send a P_PROTOCOL_UPDATE packet at
3621                  * the same time; otherwise, the peer has no way to
3622                  * tell between which packets the algorithm should
3623                  * change.
3624                  */
3625
3626                 peer_integrity_tfm = crypto_alloc_ahash(integrity_alg, 0, CRYPTO_ALG_ASYNC);
3627                 if (IS_ERR(peer_integrity_tfm)) {
3628                         peer_integrity_tfm = NULL;
3629                         drbd_err(connection, "peer data-integrity-alg %s not supported\n",
3630                                  integrity_alg);
3631                         goto disconnect;
3632                 }
3633
3634                 hash_size = crypto_ahash_digestsize(peer_integrity_tfm);
3635                 int_dig_in = kmalloc(hash_size, GFP_KERNEL);
3636                 int_dig_vv = kmalloc(hash_size, GFP_KERNEL);
3637                 if (!(int_dig_in && int_dig_vv)) {
3638                         drbd_err(connection, "Allocation of buffers for data integrity checking failed\n");
3639                         goto disconnect;
3640                 }
3641         }
3642
3643         new_net_conf = kmalloc(sizeof(struct net_conf), GFP_KERNEL);
3644         if (!new_net_conf) {
3645                 drbd_err(connection, "Allocation of new net_conf failed\n");
3646                 goto disconnect;
3647         }
3648
3649         mutex_lock(&connection->data.mutex);
3650         mutex_lock(&connection->resource->conf_update);
3651         old_net_conf = connection->net_conf;
3652         *new_net_conf = *old_net_conf;
3653
3654         new_net_conf->wire_protocol = p_proto;
3655         new_net_conf->after_sb_0p = convert_after_sb(p_after_sb_0p);
3656         new_net_conf->after_sb_1p = convert_after_sb(p_after_sb_1p);
3657         new_net_conf->after_sb_2p = convert_after_sb(p_after_sb_2p);
3658         new_net_conf->two_primaries = p_two_primaries;
3659
3660         rcu_assign_pointer(connection->net_conf, new_net_conf);
3661         mutex_unlock(&connection->resource->conf_update);
3662         mutex_unlock(&connection->data.mutex);
3663
3664         crypto_free_ahash(connection->peer_integrity_tfm);
3665         kfree(connection->int_dig_in);
3666         kfree(connection->int_dig_vv);
3667         connection->peer_integrity_tfm = peer_integrity_tfm;
3668         connection->int_dig_in = int_dig_in;
3669         connection->int_dig_vv = int_dig_vv;
3670
3671         if (strcmp(old_net_conf->integrity_alg, integrity_alg))
3672                 drbd_info(connection, "peer data-integrity-alg: %s\n",
3673                           integrity_alg[0] ? integrity_alg : "(none)");
3674
3675         synchronize_rcu();
3676         kfree(old_net_conf);
3677         return 0;
3678
3679 disconnect_rcu_unlock:
3680         rcu_read_unlock();
3681 disconnect:
3682         crypto_free_ahash(peer_integrity_tfm);
3683         kfree(int_dig_in);
3684         kfree(int_dig_vv);
3685         conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD);
3686         return -EIO;
3687 }
3688
3689 /* helper function
3690  * input: alg name, feature name
3691  * return: NULL (alg name was "")
3692  *         ERR_PTR(error) if something goes wrong
3693  *         or the crypto hash ptr, if it worked out ok. */
3694 static struct crypto_ahash *drbd_crypto_alloc_digest_safe(const struct drbd_device *device,
3695                 const char *alg, const char *name)
3696 {
3697         struct crypto_ahash *tfm;
3698
3699         if (!alg[0])
3700                 return NULL;
3701
3702         tfm = crypto_alloc_ahash(alg, 0, CRYPTO_ALG_ASYNC);
3703         if (IS_ERR(tfm)) {
3704                 drbd_err(device, "Can not allocate \"%s\" as %s (reason: %ld)\n",
3705                         alg, name, PTR_ERR(tfm));
3706                 return tfm;
3707         }
3708         return tfm;
3709 }
3710
3711 static int ignore_remaining_packet(struct drbd_connection *connection, struct packet_info *pi)
3712 {
3713         void *buffer = connection->data.rbuf;
3714         int size = pi->size;
3715
3716         while (size) {
3717                 int s = min_t(int, size, DRBD_SOCKET_BUFFER_SIZE);
3718                 s = drbd_recv(connection, buffer, s);
3719                 if (s <= 0) {
3720                         if (s < 0)
3721                                 return s;
3722                         break;
3723                 }
3724                 size -= s;
3725         }
3726         if (size)
3727                 return -EIO;
3728         return 0;
3729 }
3730
3731 /*
3732  * config_unknown_volume  -  device configuration command for unknown volume
3733  *
3734  * When a device is added to an existing connection, the node on which the
3735  * device is added first will send configuration commands to its peer but the
3736  * peer will not know about the device yet.  It will warn and ignore these
3737  * commands.  Once the device is added on the second node, the second node will
3738  * send the same device configuration commands, but in the other direction.
3739  *
3740  * (We can also end up here if drbd is misconfigured.)
3741  */
3742 static int config_unknown_volume(struct drbd_connection *connection, struct packet_info *pi)
3743 {
3744         drbd_warn(connection, "%s packet received for volume %u, which is not configured locally\n",
3745                   cmdname(pi->cmd), pi->vnr);
3746         return ignore_remaining_packet(connection, pi);
3747 }
3748
3749 static int receive_SyncParam(struct drbd_connection *connection, struct packet_info *pi)
3750 {
3751         struct drbd_peer_device *peer_device;
3752         struct drbd_device *device;
3753         struct p_rs_param_95 *p;
3754         unsigned int header_size, data_size, exp_max_sz;
3755         struct crypto_ahash *verify_tfm = NULL;
3756         struct crypto_ahash *csums_tfm = NULL;
3757         struct net_conf *old_net_conf, *new_net_conf = NULL;
3758         struct disk_conf *old_disk_conf = NULL, *new_disk_conf = NULL;
3759         const int apv = connection->agreed_pro_version;
3760         struct fifo_buffer *old_plan = NULL, *new_plan = NULL;
3761         int fifo_size = 0;
3762         int err;
3763
3764         peer_device = conn_peer_device(connection, pi->vnr);
3765         if (!peer_device)
3766                 return config_unknown_volume(connection, pi);
3767         device = peer_device->device;
3768
3769         exp_max_sz  = apv <= 87 ? sizeof(struct p_rs_param)
3770                     : apv == 88 ? sizeof(struct p_rs_param)
3771                                         + SHARED_SECRET_MAX
3772                     : apv <= 94 ? sizeof(struct p_rs_param_89)
3773                     : /* apv >= 95 */ sizeof(struct p_rs_param_95);
3774
3775         if (pi->size > exp_max_sz) {
3776                 drbd_err(device, "SyncParam packet too long: received %u, expected <= %u bytes\n",
3777                     pi->size, exp_max_sz);
3778                 return -EIO;
3779         }
3780
3781         if (apv <= 88) {
3782                 header_size = sizeof(struct p_rs_param);
3783                 data_size = pi->size - header_size;
3784         } else if (apv <= 94) {
3785                 header_size = sizeof(struct p_rs_param_89);
3786                 data_size = pi->size - header_size;
3787                 D_ASSERT(device, data_size == 0);
3788         } else {
3789                 header_size = sizeof(struct p_rs_param_95);
3790                 data_size = pi->size - header_size;
3791                 D_ASSERT(device, data_size == 0);
3792         }
3793
3794         /* initialize verify_alg and csums_alg */
3795         p = pi->data;
3796         memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);
3797
3798         err = drbd_recv_all(peer_device->connection, p, header_size);
3799         if (err)
3800                 return err;
3801
3802         mutex_lock(&connection->resource->conf_update);
3803         old_net_conf = peer_device->connection->net_conf;
3804         if (get_ldev(device)) {
3805                 new_disk_conf = kzalloc(sizeof(struct disk_conf), GFP_KERNEL);
3806                 if (!new_disk_conf) {
3807                         put_ldev(device);
3808                         mutex_unlock(&connection->resource->conf_update);
3809                         drbd_err(device, "Allocation of new disk_conf failed\n");
3810                         return -ENOMEM;
3811                 }
3812
3813                 old_disk_conf = device->ldev->disk_conf;
3814                 *new_disk_conf = *old_disk_conf;
3815
3816                 new_disk_conf->resync_rate = be32_to_cpu(p->resync_rate);
3817         }
3818
3819         if (apv >= 88) {
3820                 if (apv == 88) {
3821                         if (data_size > SHARED_SECRET_MAX || data_size == 0) {
3822                                 drbd_err(device, "verify-alg of wrong size, "
3823                                         "peer wants %u, accepting only up to %u byte\n",
3824                                         data_size, SHARED_SECRET_MAX);
3825                                 err = -EIO;
3826                                 goto reconnect;
3827                         }
3828
3829                         err = drbd_recv_all(peer_device->connection, p->verify_alg, data_size);
3830                         if (err)
3831                                 goto reconnect;
3832                         /* we expect NUL terminated string */
3833                         /* but just in case someone tries to be evil */
3834                         D_ASSERT(device, p->verify_alg[data_size-1] == 0);
3835                         p->verify_alg[data_size-1] = 0;
3836
3837                 } else /* apv >= 89 */ {
3838                         /* we still expect NUL terminated strings */
3839                         /* but just in case someone tries to be evil */
3840                         D_ASSERT(device, p->verify_alg[SHARED_SECRET_MAX-1] == 0);
3841                         D_ASSERT(device, p->csums_alg[SHARED_SECRET_MAX-1] == 0);
3842                         p->verify_alg[SHARED_SECRET_MAX-1] = 0;
3843                         p->csums_alg[SHARED_SECRET_MAX-1] = 0;
3844                 }
3845
3846                 if (strcmp(old_net_conf->verify_alg, p->verify_alg)) {
3847                         if (device->state.conn == C_WF_REPORT_PARAMS) {
3848                                 drbd_err(device, "Different verify-alg settings. me=\"%s\" peer=\"%s\"\n",
3849                                     old_net_conf->verify_alg, p->verify_alg);
3850                                 goto disconnect;
3851                         }
3852                         verify_tfm = drbd_crypto_alloc_digest_safe(device,
3853                                         p->verify_alg, "verify-alg");
3854                         if (IS_ERR(verify_tfm)) {
3855                                 verify_tfm = NULL;
3856                                 goto disconnect;
3857                         }
3858                 }
3859
3860                 if (apv >= 89 && strcmp(old_net_conf->csums_alg, p->csums_alg)) {
3861                         if (device->state.conn == C_WF_REPORT_PARAMS) {
3862                                 drbd_err(device, "Different csums-alg settings. me=\"%s\" peer=\"%s\"\n",
3863                                     old_net_conf->csums_alg, p->csums_alg);
3864                                 goto disconnect;
3865                         }
3866                         csums_tfm = drbd_crypto_alloc_digest_safe(device,
3867                                         p->csums_alg, "csums-alg");
3868                         if (IS_ERR(csums_tfm)) {
3869                                 csums_tfm = NULL;
3870                                 goto disconnect;
3871                         }
3872                 }
3873
3874                 if (apv > 94 && new_disk_conf) {
3875                         new_disk_conf->c_plan_ahead = be32_to_cpu(p->c_plan_ahead);
3876                         new_disk_conf->c_delay_target = be32_to_cpu(p->c_delay_target);
3877                         new_disk_conf->c_fill_target = be32_to_cpu(p->c_fill_target);
3878                         new_disk_conf->c_max_rate = be32_to_cpu(p->c_max_rate);
3879
3880                         fifo_size = (new_disk_conf->c_plan_ahead * 10 * SLEEP_TIME) / HZ;
3881                         if (fifo_size != device->rs_plan_s->size) {
3882                                 new_plan = fifo_alloc(fifo_size);
3883                                 if (!new_plan) {
3884                                         drbd_err(device, "kmalloc of fifo_buffer failed");
3885                                         put_ldev(device);
3886                                         goto disconnect;
3887                                 }
3888                         }
3889                 }
3890
3891                 if (verify_tfm || csums_tfm) {
3892                         new_net_conf = kzalloc(sizeof(struct net_conf), GFP_KERNEL);
3893                         if (!new_net_conf) {
3894                                 drbd_err(device, "Allocation of new net_conf failed\n");
3895                                 goto disconnect;
3896                         }
3897
3898                         *new_net_conf = *old_net_conf;
3899
3900                         if (verify_tfm) {
3901                                 strcpy(new_net_conf->verify_alg, p->verify_alg);
3902                                 new_net_conf->verify_alg_len = strlen(p->verify_alg) + 1;
3903                                 crypto_free_ahash(peer_device->connection->verify_tfm);
3904                                 peer_device->connection->verify_tfm = verify_tfm;
3905                                 drbd_info(device, "using verify-alg: \"%s\"\n", p->verify_alg);
3906                         }
3907                         if (csums_tfm) {
3908                                 strcpy(new_net_conf->csums_alg, p->csums_alg);
3909                                 new_net_conf->csums_alg_len = strlen(p->csums_alg) + 1;
3910                                 crypto_free_ahash(peer_device->connection->csums_tfm);
3911                                 peer_device->connection->csums_tfm = csums_tfm;
3912                                 drbd_info(device, "using csums-alg: \"%s\"\n", p->csums_alg);
3913                         }
3914                         rcu_assign_pointer(connection->net_conf, new_net_conf);
3915                 }
3916         }
3917
3918         if (new_disk_conf) {
3919                 rcu_assign_pointer(device->ldev->disk_conf, new_disk_conf);
3920                 put_ldev(device);
3921         }
3922
3923         if (new_plan) {
3924                 old_plan = device->rs_plan_s;
3925                 rcu_assign_pointer(device->rs_plan_s, new_plan);
3926         }
3927
3928         mutex_unlock(&connection->resource->conf_update);
3929         synchronize_rcu();
3930         if (new_net_conf)
3931                 kfree(old_net_conf);
3932         kfree(old_disk_conf);
3933         kfree(old_plan);
3934
3935         return 0;
3936
3937 reconnect:
3938         if (new_disk_conf) {
3939                 put_ldev(device);
3940                 kfree(new_disk_conf);
3941         }
3942         mutex_unlock(&connection->resource->conf_update);
3943         return -EIO;
3944
3945 disconnect:
3946         kfree(new_plan);
3947         if (new_disk_conf) {
3948                 put_ldev(device);
3949                 kfree(new_disk_conf);
3950         }
3951         mutex_unlock(&connection->resource->conf_update);
3952         /* just for completeness: actually not needed,
3953          * as this is not reached if csums_tfm was ok. */
3954         crypto_free_ahash(csums_tfm);
3955         /* but free the verify_tfm again, if csums_tfm did not work out */
3956         crypto_free_ahash(verify_tfm);
3957         conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD);
3958         return -EIO;
3959 }
3960
3961 /* warn if the arguments differ by more than 12.5% */
3962 static void warn_if_differ_considerably(struct drbd_device *device,
3963         const char *s, sector_t a, sector_t b)
3964 {
3965         sector_t d;
3966         if (a == 0 || b == 0)
3967                 return;
3968         d = (a > b) ? (a - b) : (b - a);
3969         if (d > (a>>3) || d > (b>>3))
3970                 drbd_warn(device, "Considerable difference in %s: %llus vs. %llus\n", s,
3971                      (unsigned long long)a, (unsigned long long)b);
3972 }
3973
3974 static int receive_sizes(struct drbd_connection *connection, struct packet_info *pi)
3975 {
3976         struct drbd_peer_device *peer_device;
3977         struct drbd_device *device;
3978         struct p_sizes *p = pi->data;
3979         struct o_qlim *o = (connection->agreed_features & DRBD_FF_WSAME) ? p->qlim : NULL;
3980         enum determine_dev_size dd = DS_UNCHANGED;
3981         sector_t p_size, p_usize, p_csize, my_usize;
3982         int ldsc = 0; /* local disk size changed */
3983         enum dds_flags ddsf;
3984
3985         peer_device = conn_peer_device(connection, pi->vnr);
3986         if (!peer_device)
3987                 return config_unknown_volume(connection, pi);
3988         device = peer_device->device;
3989
3990         p_size = be64_to_cpu(p->d_size);
3991         p_usize = be64_to_cpu(p->u_size);
3992         p_csize = be64_to_cpu(p->c_size);
3993
3994         /* just store the peer's disk size for now.
3995          * we still need to figure out whether we accept that. */
3996         device->p_size = p_size;
3997
3998         if (get_ldev(device)) {
3999                 sector_t new_size, cur_size;
4000                 rcu_read_lock();
4001                 my_usize = rcu_dereference(device->ldev->disk_conf)->disk_size;
4002                 rcu_read_unlock();
4003
4004                 warn_if_differ_considerably(device, "lower level device sizes",
4005                            p_size, drbd_get_max_capacity(device->ldev));
4006                 warn_if_differ_considerably(device, "user requested size",
4007                                             p_usize, my_usize);
4008
4009                 /* if this is the first connect, or an otherwise expected
4010                  * param exchange, choose the minimum */
4011                 if (device->state.conn == C_WF_REPORT_PARAMS)
4012                         p_usize = min_not_zero(my_usize, p_usize);
4013
4014                 /* Never shrink a device with usable data during connect.
4015                    But allow online shrinking if we are connected. */
4016                 new_size = drbd_new_dev_size(device, device->ldev, p_usize, 0);
4017                 cur_size = drbd_get_capacity(device->this_bdev);
4018                 if (new_size < cur_size &&
4019                     device->state.disk >= D_OUTDATED &&
4020                     device->state.conn < C_CONNECTED) {
4021                         drbd_err(device, "The peer's disk size is too small! (%llu < %llu sectors)\n",
4022                                         (unsigned long long)new_size, (unsigned long long)cur_size);
4023                         conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD);
4024                         put_ldev(device);
4025                         return -EIO;
4026                 }
4027
4028                 if (my_usize != p_usize) {
4029                         struct disk_conf *old_disk_conf, *new_disk_conf = NULL;
4030
4031                         new_disk_conf = kzalloc(sizeof(struct disk_conf), GFP_KERNEL);
4032                         if (!new_disk_conf) {
4033                                 drbd_err(device, "Allocation of new disk_conf failed\n");
4034                                 put_ldev(device);
4035                                 return -ENOMEM;
4036                         }
4037
4038                         mutex_lock(&connection->resource->conf_update);
4039                         old_disk_conf = device->ldev->disk_conf;
4040                         *new_disk_conf = *old_disk_conf;
4041                         new_disk_conf->disk_size = p_usize;
4042
4043                         rcu_assign_pointer(device->ldev->disk_conf, new_disk_conf);
4044                         mutex_unlock(&connection->resource->conf_update);
4045                         synchronize_rcu();
4046                         kfree(old_disk_conf);
4047
4048                         drbd_info(device, "Peer sets u_size to %lu sectors\n",
4049                                  (unsigned long)my_usize);
4050                 }
4051
4052                 put_ldev(device);
4053         }
4054
4055         device->peer_max_bio_size = be32_to_cpu(p->max_bio_size);
4056         /* Leave drbd_reconsider_queue_parameters() before drbd_determine_dev_size().
4057            In case we cleared the QUEUE_FLAG_DISCARD from our queue in
4058            drbd_reconsider_queue_parameters(), we can be sure that after
4059            drbd_determine_dev_size() no REQ_DISCARDs are in the queue. */
4060
4061         ddsf = be16_to_cpu(p->dds_flags);
4062         if (get_ldev(device)) {
4063                 drbd_reconsider_queue_parameters(device, device->ldev, o);
4064                 dd = drbd_determine_dev_size(device, ddsf, NULL);
4065                 put_ldev(device);
4066                 if (dd == DS_ERROR)
4067                         return -EIO;
4068                 drbd_md_sync(device);
4069         } else {
4070                 /*
4071                  * I am diskless, need to accept the peer's *current* size.
4072                  * I must NOT accept the peers backing disk size,
4073                  * it may have been larger than mine all along...
4074                  *
4075                  * At this point, the peer knows more about my disk, or at
4076                  * least about what we last agreed upon, than myself.
4077                  * So if his c_size is less than his d_size, the most likely
4078                  * reason is that *my* d_size was smaller last time we checked.
4079                  *
4080                  * However, if he sends a zero current size,
4081                  * take his (user-capped or) backing disk size anyways.
4082                  */
4083                 drbd_reconsider_queue_parameters(device, NULL, o);
4084                 drbd_set_my_capacity(device, p_csize ?: p_usize ?: p_size);
4085         }
4086
4087         if (get_ldev(device)) {
4088                 if (device->ldev->known_size != drbd_get_capacity(device->ldev->backing_bdev)) {
4089                         device->ldev->known_size = drbd_get_capacity(device->ldev->backing_bdev);
4090                         ldsc = 1;
4091                 }
4092
4093                 put_ldev(device);
4094         }
4095
4096         if (device->state.conn > C_WF_REPORT_PARAMS) {
4097                 if (be64_to_cpu(p->c_size) !=
4098                     drbd_get_capacity(device->this_bdev) || ldsc) {
4099                         /* we have different sizes, probably peer
4100                          * needs to know my new size... */
4101                         drbd_send_sizes(peer_device, 0, ddsf);
4102                 }
4103                 if (test_and_clear_bit(RESIZE_PENDING, &device->flags) ||
4104                     (dd == DS_GREW && device->state.conn == C_CONNECTED)) {
4105                         if (device->state.pdsk >= D_INCONSISTENT &&
4106                             device->state.disk >= D_INCONSISTENT) {
4107                                 if (ddsf & DDSF_NO_RESYNC)
4108                                         drbd_info(device, "Resync of new storage suppressed with --assume-clean\n");
4109                                 else
4110                                         resync_after_online_grow(device);
4111                         } else
4112                                 set_bit(RESYNC_AFTER_NEG, &device->flags);
4113                 }
4114         }
4115
4116         return 0;
4117 }
4118
4119 static int receive_uuids(struct drbd_connection *connection, struct packet_info *pi)
4120 {
4121         struct drbd_peer_device *peer_device;
4122         struct drbd_device *device;
4123         struct p_uuids *p = pi->data;
4124         u64 *p_uuid;
4125         int i, updated_uuids = 0;
4126
4127         peer_device = conn_peer_device(connection, pi->vnr);
4128         if (!peer_device)
4129                 return config_unknown_volume(connection, pi);
4130         device = peer_device->device;
4131
4132         p_uuid = kmalloc_array(UI_EXTENDED_SIZE, sizeof(*p_uuid), GFP_NOIO);
4133         if (!p_uuid) {
4134                 drbd_err(device, "kmalloc of p_uuid failed\n");
4135                 return false;
4136         }
4137
4138         for (i = UI_CURRENT; i < UI_EXTENDED_SIZE; i++)
4139                 p_uuid[i] = be64_to_cpu(p->uuid[i]);
4140
4141         kfree(device->p_uuid);
4142         device->p_uuid = p_uuid;
4143
4144         if (device->state.conn < C_CONNECTED &&
4145             device->state.disk < D_INCONSISTENT &&
4146             device->state.role == R_PRIMARY &&
4147             (device->ed_uuid & ~((u64)1)) != (p_uuid[UI_CURRENT] & ~((u64)1))) {
4148                 drbd_err(device, "Can only connect to data with current UUID=%016llX\n",
4149                     (unsigned long long)device->ed_uuid);
4150                 conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD);
4151                 return -EIO;
4152         }
4153
4154         if (get_ldev(device)) {
4155                 int skip_initial_sync =
4156                         device->state.conn == C_CONNECTED &&
4157                         peer_device->connection->agreed_pro_version >= 90 &&
4158                         device->ldev->md.uuid[UI_CURRENT] == UUID_JUST_CREATED &&
4159                         (p_uuid[UI_FLAGS] & 8);
4160                 if (skip_initial_sync) {
4161                         drbd_info(device, "Accepted new current UUID, preparing to skip initial sync\n");
4162                         drbd_bitmap_io(device, &drbd_bmio_clear_n_write,
4163                                         "clear_n_write from receive_uuids",
4164                                         BM_LOCKED_TEST_ALLOWED);
4165                         _drbd_uuid_set(device, UI_CURRENT, p_uuid[UI_CURRENT]);
4166                         _drbd_uuid_set(device, UI_BITMAP, 0);
4167                         _drbd_set_state(_NS2(device, disk, D_UP_TO_DATE, pdsk, D_UP_TO_DATE),
4168                                         CS_VERBOSE, NULL);
4169                         drbd_md_sync(device);
4170                         updated_uuids = 1;
4171                 }
4172                 put_ldev(device);
4173         } else if (device->state.disk < D_INCONSISTENT &&
4174                    device->state.role == R_PRIMARY) {
4175                 /* I am a diskless primary, the peer just created a new current UUID
4176                    for me. */
4177                 updated_uuids = drbd_set_ed_uuid(device, p_uuid[UI_CURRENT]);
4178         }
4179
4180         /* Before we test for the disk state, we should wait until an eventually
4181            ongoing cluster wide state change is finished. That is important if
4182            we are primary and are detaching from our disk. We need to see the
4183            new disk state... */
4184         mutex_lock(device->state_mutex);
4185         mutex_unlock(device->state_mutex);
4186         if (device->state.conn >= C_CONNECTED && device->state.disk < D_INCONSISTENT)
4187                 updated_uuids |= drbd_set_ed_uuid(device, p_uuid[UI_CURRENT]);
4188
4189         if (updated_uuids)
4190                 drbd_print_uuids(device, "receiver updated UUIDs to");
4191
4192         return 0;
4193 }
4194
4195 /**
4196  * convert_state() - Converts the peer's view of the cluster state to our point of view
4197  * @ps:         The state as seen by the peer.
4198  */
4199 static union drbd_state convert_state(union drbd_state ps)
4200 {
4201         union drbd_state ms;
4202
4203         static enum drbd_conns c_tab[] = {
4204                 [C_WF_REPORT_PARAMS] = C_WF_REPORT_PARAMS,
4205                 [C_CONNECTED] = C_CONNECTED,
4206
4207                 [C_STARTING_SYNC_S] = C_STARTING_SYNC_T,
4208                 [C_STARTING_SYNC_T] = C_STARTING_SYNC_S,
4209                 [C_DISCONNECTING] = C_TEAR_DOWN, /* C_NETWORK_FAILURE, */
4210                 [C_VERIFY_S]       = C_VERIFY_T,
4211                 [C_MASK]   = C_MASK,
4212         };
4213
4214         ms.i = ps.i;
4215
4216         ms.conn = c_tab[ps.conn];
4217         ms.peer = ps.role;
4218         ms.role = ps.peer;
4219         ms.pdsk = ps.disk;
4220         ms.disk = ps.pdsk;
4221         ms.peer_isp = (ps.aftr_isp | ps.user_isp);
4222
4223         return ms;
4224 }
4225
4226 static int receive_req_state(struct drbd_connection *connection, struct packet_info *pi)
4227 {
4228         struct drbd_peer_device *peer_device;
4229         struct drbd_device *device;
4230         struct p_req_state *p = pi->data;
4231         union drbd_state mask, val;
4232         enum drbd_state_rv rv;
4233
4234         peer_device = conn_peer_device(connection, pi->vnr);
4235         if (!peer_device)
4236                 return -EIO;
4237         device = peer_device->device;
4238
4239         mask.i = be32_to_cpu(p->mask);
4240         val.i = be32_to_cpu(p->val);
4241
4242         if (test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags) &&
4243             mutex_is_locked(device->state_mutex)) {
4244                 drbd_send_sr_reply(peer_device, SS_CONCURRENT_ST_CHG);
4245                 return 0;
4246         }
4247
4248         mask = convert_state(mask);
4249         val = convert_state(val);
4250
4251         rv = drbd_change_state(device, CS_VERBOSE, mask, val);
4252         drbd_send_sr_reply(peer_device, rv);
4253
4254         drbd_md_sync(device);
4255
4256         return 0;
4257 }
4258
4259 static int receive_req_conn_state(struct drbd_connection *connection, struct packet_info *pi)
4260 {
4261         struct p_req_state *p = pi->data;
4262         union drbd_state mask, val;
4263         enum drbd_state_rv rv;
4264
4265         mask.i = be32_to_cpu(p->mask);
4266         val.i = be32_to_cpu(p->val);
4267
4268         if (test_bit(RESOLVE_CONFLICTS, &connection->flags) &&
4269             mutex_is_locked(&connection->cstate_mutex)) {
4270                 conn_send_sr_reply(connection, SS_CONCURRENT_ST_CHG);
4271                 return 0;
4272         }
4273
4274         mask = convert_state(mask);
4275         val = convert_state(val);
4276
4277         rv = conn_request_state(connection, mask, val, CS_VERBOSE | CS_LOCAL_ONLY | CS_IGN_OUTD_FAIL);
4278         conn_send_sr_reply(connection, rv);
4279
4280         return 0;
4281 }
4282
4283 static int receive_state(struct drbd_connection *connection, struct packet_info *pi)
4284 {
4285         struct drbd_peer_device *peer_device;
4286         struct drbd_device *device;
4287         struct p_state *p = pi->data;
4288         union drbd_state os, ns, peer_state;
4289         enum drbd_disk_state real_peer_disk;
4290         enum chg_state_flags cs_flags;
4291         int rv;
4292
4293         peer_device = conn_peer_device(connection, pi->vnr);
4294         if (!peer_device)
4295                 return config_unknown_volume(connection, pi);
4296         device = peer_device->device;
4297
4298         peer_state.i = be32_to_cpu(p->state);
4299
4300         real_peer_disk = peer_state.disk;
4301         if (peer_state.disk == D_NEGOTIATING) {
4302                 real_peer_disk = device->p_uuid[UI_FLAGS] & 4 ? D_INCONSISTENT : D_CONSISTENT;
4303                 drbd_info(device, "real peer disk state = %s\n", drbd_disk_str(real_peer_disk));
4304         }
4305
4306         spin_lock_irq(&device->resource->req_lock);
4307  retry:
4308         os = ns = drbd_read_state(device);
4309         spin_unlock_irq(&device->resource->req_lock);
4310
4311         /* If some other part of the code (ack_receiver thread, timeout)
4312          * already decided to close the connection again,
4313          * we must not "re-establish" it here. */
4314         if (os.conn <= C_TEAR_DOWN)
4315                 return -ECONNRESET;
4316
4317         /* If this is the "end of sync" confirmation, usually the peer disk
4318          * transitions from D_INCONSISTENT to D_UP_TO_DATE. For empty (0 bits
4319          * set) resync started in PausedSyncT, or if the timing of pause-/
4320          * unpause-sync events has been "just right", the peer disk may
4321          * transition from D_CONSISTENT to D_UP_TO_DATE as well.
4322          */
4323         if ((os.pdsk == D_INCONSISTENT || os.pdsk == D_CONSISTENT) &&
4324             real_peer_disk == D_UP_TO_DATE &&
4325             os.conn > C_CONNECTED && os.disk == D_UP_TO_DATE) {
4326                 /* If we are (becoming) SyncSource, but peer is still in sync
4327                  * preparation, ignore its uptodate-ness to avoid flapping, it
4328                  * will change to inconsistent once the peer reaches active
4329                  * syncing states.
4330                  * It may have changed syncer-paused flags, however, so we
4331                  * cannot ignore this completely. */
4332                 if (peer_state.conn > C_CONNECTED &&
4333                     peer_state.conn < C_SYNC_SOURCE)
4334                         real_peer_disk = D_INCONSISTENT;
4335
4336                 /* if peer_state changes to connected at the same time,
4337                  * it explicitly notifies us that it finished resync.
4338                  * Maybe we should finish it up, too? */
4339                 else if (os.conn >= C_SYNC_SOURCE &&
4340                          peer_state.conn == C_CONNECTED) {
4341                         if (drbd_bm_total_weight(device) <= device->rs_failed)
4342                                 drbd_resync_finished(device);
4343                         return 0;
4344                 }
4345         }
4346
4347         /* explicit verify finished notification, stop sector reached. */
4348         if (os.conn == C_VERIFY_T && os.disk == D_UP_TO_DATE &&
4349             peer_state.conn == C_CONNECTED && real_peer_disk == D_UP_TO_DATE) {
4350                 ov_out_of_sync_print(device);
4351                 drbd_resync_finished(device);
4352                 return 0;
4353         }
4354
4355         /* peer says his disk is inconsistent, while we think it is uptodate,
4356          * and this happens while the peer still thinks we have a sync going on,
4357          * but we think we are already done with the sync.
4358          * We ignore this to avoid flapping pdsk.
4359          * This should not happen, if the peer is a recent version of drbd. */
4360         if (os.pdsk == D_UP_TO_DATE && real_peer_disk == D_INCONSISTENT &&
4361             os.conn == C_CONNECTED && peer_state.conn > C_SYNC_SOURCE)
4362                 real_peer_disk = D_UP_TO_DATE;
4363
4364         if (ns.conn == C_WF_REPORT_PARAMS)
4365                 ns.conn = C_CONNECTED;
4366
4367         if (peer_state.conn == C_AHEAD)
4368                 ns.conn = C_BEHIND;
4369
4370         if (device->p_uuid && peer_state.disk >= D_NEGOTIATING &&
4371             get_ldev_if_state(device, D_NEGOTIATING)) {
4372                 int cr; /* consider resync */
4373
4374                 /* if we established a new connection */
4375                 cr  = (os.conn < C_CONNECTED);
4376                 /* if we had an established connection
4377                  * and one of the nodes newly attaches a disk */
4378                 cr |= (os.conn == C_CONNECTED &&
4379                        (peer_state.disk == D_NEGOTIATING ||
4380                         os.disk == D_NEGOTIATING));
4381                 /* if we have both been inconsistent, and the peer has been
4382                  * forced to be UpToDate with --overwrite-data */
4383                 cr |= test_bit(CONSIDER_RESYNC, &device->flags);
4384                 /* if we had been plain connected, and the admin requested to
4385                  * start a sync by "invalidate" or "invalidate-remote" */
4386                 cr |= (os.conn == C_CONNECTED &&
4387                                 (peer_state.conn >= C_STARTING_SYNC_S &&
4388                                  peer_state.conn <= C_WF_BITMAP_T));
4389
4390                 if (cr)
4391                         ns.conn = drbd_sync_handshake(peer_device, peer_state.role, real_peer_disk);
4392
4393                 put_ldev(device);
4394                 if (ns.conn == C_MASK) {
4395                         ns.conn = C_CONNECTED;
4396                         if (device->state.disk == D_NEGOTIATING) {
4397                                 drbd_force_state(device, NS(disk, D_FAILED));
4398                         } else if (peer_state.disk == D_NEGOTIATING) {
4399                                 drbd_err(device, "Disk attach process on the peer node was aborted.\n");
4400                                 peer_state.disk = D_DISKLESS;
4401                                 real_peer_disk = D_DISKLESS;
4402                         } else {
4403                                 if (test_and_clear_bit(CONN_DRY_RUN, &peer_device->connection->flags))
4404                                         return -EIO;
4405                                 D_ASSERT(device, os.conn == C_WF_REPORT_PARAMS);
4406                                 conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD);
4407                                 return -EIO;
4408                         }
4409                 }
4410         }
4411
4412         spin_lock_irq(&device->resource->req_lock);
4413         if (os.i != drbd_read_state(device).i)
4414                 goto retry;
4415         clear_bit(CONSIDER_RESYNC, &device->flags);
4416         ns.peer = peer_state.role;
4417         ns.pdsk = real_peer_disk;
4418         ns.peer_isp = (peer_state.aftr_isp | peer_state.user_isp);
4419         if ((ns.conn == C_CONNECTED || ns.conn == C_WF_BITMAP_S) && ns.disk == D_NEGOTIATING)
4420                 ns.disk = device->new_state_tmp.disk;
4421         cs_flags = CS_VERBOSE + (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED ? 0 : CS_HARD);
4422         if (ns.pdsk == D_CONSISTENT && drbd_suspended(device) && ns.conn == C_CONNECTED && os.conn < C_CONNECTED &&
4423             test_bit(NEW_CUR_UUID, &device->flags)) {
4424                 /* Do not allow tl_restart(RESEND) for a rebooted peer. We can only allow this
4425                    for temporal network outages! */
4426                 spin_unlock_irq(&device->resource->req_lock);
4427                 drbd_err(device, "Aborting Connect, can not thaw IO with an only Consistent peer\n");
4428                 tl_clear(peer_device->connection);
4429                 drbd_uuid_new_current(device);
4430                 clear_bit(NEW_CUR_UUID, &device->flags);
4431                 conn_request_state(peer_device->connection, NS2(conn, C_PROTOCOL_ERROR, susp, 0), CS_HARD);
4432                 return -EIO;
4433         }
4434         rv = _drbd_set_state(device, ns, cs_flags, NULL);
4435         ns = drbd_read_state(device);
4436         spin_unlock_irq(&device->resource->req_lock);
4437
4438         if (rv < SS_SUCCESS) {
4439                 conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD);
4440                 return -EIO;
4441         }
4442
4443         if (os.conn > C_WF_REPORT_PARAMS) {
4444                 if (ns.conn > C_CONNECTED && peer_state.conn <= C_CONNECTED &&
4445                     peer_state.disk != D_NEGOTIATING ) {
4446                         /* we want resync, peer has not yet decided to sync... */
4447                         /* Nowadays only used when forcing a node into primary role and
4448                            setting its disk to UpToDate with that */
4449                         drbd_send_uuids(peer_device);
4450                         drbd_send_current_state(peer_device);
4451                 }
4452         }
4453
4454         clear_bit(DISCARD_MY_DATA, &device->flags);
4455
4456         drbd_md_sync(device); /* update connected indicator, la_size_sect, ... */
4457
4458         return 0;
4459 }
4460
4461 static int receive_sync_uuid(struct drbd_connection *connection, struct packet_info *pi)
4462 {
4463         struct drbd_peer_device *peer_device;
4464         struct drbd_device *device;
4465         struct p_rs_uuid *p = pi->data;
4466
4467         peer_device = conn_peer_device(connection, pi->vnr);
4468         if (!peer_device)
4469                 return -EIO;
4470         device = peer_device->device;
4471
4472         wait_event(device->misc_wait,
4473                    device->state.conn == C_WF_SYNC_UUID ||
4474                    device->state.conn == C_BEHIND ||
4475                    device->state.conn < C_CONNECTED ||
4476                    device->state.disk < D_NEGOTIATING);
4477
4478         /* D_ASSERT(device,  device->state.conn == C_WF_SYNC_UUID ); */
4479
4480         /* Here the _drbd_uuid_ functions are right, current should
4481            _not_ be rotated into the history */
4482         if (get_ldev_if_state(device, D_NEGOTIATING)) {
4483                 _drbd_uuid_set(device, UI_CURRENT, be64_to_cpu(p->uuid));
4484                 _drbd_uuid_set(device, UI_BITMAP, 0UL);
4485
4486                 drbd_print_uuids(device, "updated sync uuid");
4487                 drbd_start_resync(device, C_SYNC_TARGET);
4488
4489                 put_ldev(device);
4490         } else
4491                 drbd_err(device, "Ignoring SyncUUID packet!\n");
4492
4493         return 0;
4494 }
4495
4496 /**
4497  * receive_bitmap_plain
4498  *
4499  * Return 0 when done, 1 when another iteration is needed, and a negative error
4500  * code upon failure.
4501  */
4502 static int
4503 receive_bitmap_plain(struct drbd_peer_device *peer_device, unsigned int size,
4504                      unsigned long *p, struct bm_xfer_ctx *c)
4505 {
4506         unsigned int data_size = DRBD_SOCKET_BUFFER_SIZE -
4507                                  drbd_header_size(peer_device->connection);
4508         unsigned int num_words = min_t(size_t, data_size / sizeof(*p),
4509                                        c->bm_words - c->word_offset);
4510         unsigned int want = num_words * sizeof(*p);
4511         int err;
4512
4513         if (want != size) {
4514                 drbd_err(peer_device, "%s:want (%u) != size (%u)\n", __func__, want, size);
4515                 return -EIO;
4516         }
4517         if (want == 0)
4518                 return 0;
4519         err = drbd_recv_all(peer_device->connection, p, want);
4520         if (err)
4521                 return err;
4522
4523         drbd_bm_merge_lel(peer_device->device, c->word_offset, num_words, p);
4524
4525         c->word_offset += num_words;
4526         c->bit_offset = c->word_offset * BITS_PER_LONG;
4527         if (c->bit_offset > c->bm_bits)
4528                 c->bit_offset = c->bm_bits;
4529
4530         return 1;
4531 }
4532
4533 static enum drbd_bitmap_code dcbp_get_code(struct p_compressed_bm *p)
4534 {
4535         return (enum drbd_bitmap_code)(p->encoding & 0x0f);
4536 }
4537
4538 static int dcbp_get_start(struct p_compressed_bm *p)
4539 {
4540         return (p->encoding & 0x80) != 0;
4541 }
4542
4543 static int dcbp_get_pad_bits(struct p_compressed_bm *p)
4544 {
4545         return (p->encoding >> 4) & 0x7;
4546 }
4547
4548 /**
4549  * recv_bm_rle_bits
4550  *
4551  * Return 0 when done, 1 when another iteration is needed, and a negative error
4552  * code upon failure.
4553  */
4554 static int
4555 recv_bm_rle_bits(struct drbd_peer_device *peer_device,
4556                 struct p_compressed_bm *p,
4557                  struct bm_xfer_ctx *c,
4558                  unsigned int len)
4559 {
4560         struct bitstream bs;
4561         u64 look_ahead;
4562         u64 rl;
4563         u64 tmp;
4564         unsigned long s = c->bit_offset;
4565         unsigned long e;
4566         int toggle = dcbp_get_start(p);
4567         int have;
4568         int bits;
4569
4570         bitstream_init(&bs, p->code, len, dcbp_get_pad_bits(p));
4571
4572         bits = bitstream_get_bits(&bs, &look_ahead, 64);
4573         if (bits < 0)
4574                 return -EIO;
4575
4576         for (have = bits; have > 0; s += rl, toggle = !toggle) {
4577                 bits = vli_decode_bits(&rl, look_ahead);
4578                 if (bits <= 0)
4579                         return -EIO;
4580
4581                 if (toggle) {
4582                         e = s + rl -1;
4583                         if (e >= c->bm_bits) {
4584                                 drbd_err(peer_device, "bitmap overflow (e:%lu) while decoding bm RLE packet\n", e);
4585                                 return -EIO;
4586                         }
4587                         _drbd_bm_set_bits(peer_device->device, s, e);
4588                 }
4589
4590                 if (have < bits) {
4591                         drbd_err(peer_device, "bitmap decoding error: h:%d b:%d la:0x%08llx l:%u/%u\n",
4592                                 have, bits, look_ahead,
4593                                 (unsigned int)(bs.cur.b - p->code),
4594                                 (unsigned int)bs.buf_len);
4595                         return -EIO;
4596                 }
4597                 /* if we consumed all 64 bits, assign 0; >> 64 is "undefined"; */
4598                 if (likely(bits < 64))
4599                         look_ahead >>= bits;
4600                 else
4601                         look_ahead = 0;
4602                 have -= bits;
4603
4604                 bits = bitstream_get_bits(&bs, &tmp, 64 - have);
4605                 if (bits < 0)
4606                         return -EIO;
4607                 look_ahead |= tmp << have;
4608                 have += bits;
4609         }
4610
4611         c->bit_offset = s;
4612         bm_xfer_ctx_bit_to_word_offset(c);
4613
4614         return (s != c->bm_bits);
4615 }
4616
4617 /**
4618  * decode_bitmap_c
4619  *
4620  * Return 0 when done, 1 when another iteration is needed, and a negative error
4621  * code upon failure.
4622  */
4623 static int
4624 decode_bitmap_c(struct drbd_peer_device *peer_device,
4625                 struct p_compressed_bm *p,
4626                 struct bm_xfer_ctx *c,
4627                 unsigned int len)
4628 {
4629         if (dcbp_get_code(p) == RLE_VLI_Bits)
4630                 return recv_bm_rle_bits(peer_device, p, c, len - sizeof(*p));
4631
4632         /* other variants had been implemented for evaluation,
4633          * but have been dropped as this one turned out to be "best"
4634          * during all our tests. */
4635
4636         drbd_err(peer_device, "receive_bitmap_c: unknown encoding %u\n", p->encoding);
4637         conn_request_state(peer_device->connection, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
4638         return -EIO;
4639 }
4640
4641 void INFO_bm_xfer_stats(struct drbd_device *device,
4642                 const char *direction, struct bm_xfer_ctx *c)
4643 {
4644         /* what would it take to transfer it "plaintext" */
4645         unsigned int header_size = drbd_header_size(first_peer_device(device)->connection);
4646         unsigned int data_size = DRBD_SOCKET_BUFFER_SIZE - header_size;
4647         unsigned int plain =
4648                 header_size * (DIV_ROUND_UP(c->bm_words, data_size) + 1) +
4649                 c->bm_words * sizeof(unsigned long);
4650         unsigned int total = c->bytes[0] + c->bytes[1];
4651         unsigned int r;
4652
4653         /* total can not be zero. but just in case: */
4654         if (total == 0)
4655                 return;
4656
4657         /* don't report if not compressed */
4658         if (total >= plain)
4659                 return;
4660
4661         /* total < plain. check for overflow, still */
4662         r = (total > UINT_MAX/1000) ? (total / (plain/1000))
4663                                     : (1000 * total / plain);
4664
4665         if (r > 1000)
4666                 r = 1000;
4667
4668         r = 1000 - r;
4669         drbd_info(device, "%s bitmap stats [Bytes(packets)]: plain %u(%u), RLE %u(%u), "
4670              "total %u; compression: %u.%u%%\n",
4671                         direction,
4672                         c->bytes[1], c->packets[1],
4673                         c->bytes[0], c->packets[0],
4674                         total, r/10, r % 10);
4675 }
4676
4677 /* Since we are processing the bitfield from lower addresses to higher,
4678    it does not matter if the process it in 32 bit chunks or 64 bit
4679    chunks as long as it is little endian. (Understand it as byte stream,
4680    beginning with the lowest byte...) If we would use big endian
4681    we would need to process it from the highest address to the lowest,
4682    in order to be agnostic to the 32 vs 64 bits issue.
4683
4684    returns 0 on failure, 1 if we successfully received it. */
4685 static int receive_bitmap(struct drbd_connection *connection, struct packet_info *pi)
4686 {
4687         struct drbd_peer_device *peer_device;
4688         struct drbd_device *device;
4689         struct bm_xfer_ctx c;
4690         int err;
4691
4692         peer_device = conn_peer_device(connection, pi->vnr);
4693         if (!peer_device)
4694                 return -EIO;
4695         device = peer_device->device;
4696
4697         drbd_bm_lock(device, "receive bitmap", BM_LOCKED_SET_ALLOWED);
4698         /* you are supposed to send additional out-of-sync information
4699          * if you actually set bits during this phase */
4700
4701         c = (struct bm_xfer_ctx) {
4702                 .bm_bits = drbd_bm_bits(device),
4703                 .bm_words = drbd_bm_words(device),
4704         };
4705
4706         for(;;) {
4707                 if (pi->cmd == P_BITMAP)
4708                         err = receive_bitmap_plain(peer_device, pi->size, pi->data, &c);
4709                 else if (pi->cmd == P_COMPRESSED_BITMAP) {
4710                         /* MAYBE: sanity check that we speak proto >= 90,
4711                          * and the feature is enabled! */
4712                         struct p_compressed_bm *p = pi->data;
4713
4714                         if (pi->size > DRBD_SOCKET_BUFFER_SIZE - drbd_header_size(connection)) {
4715                                 drbd_err(device, "ReportCBitmap packet too large\n");
4716                                 err = -EIO;
4717                                 goto out;
4718                         }
4719                         if (pi->size <= sizeof(*p)) {
4720                                 drbd_err(device, "ReportCBitmap packet too small (l:%u)\n", pi->size);
4721                                 err = -EIO;
4722                                 goto out;
4723                         }
4724                         err = drbd_recv_all(peer_device->connection, p, pi->size);
4725                         if (err)
4726                                goto out;
4727                         err = decode_bitmap_c(peer_device, p, &c, pi->size);
4728                 } else {
4729                         drbd_warn(device, "receive_bitmap: cmd neither ReportBitMap nor ReportCBitMap (is 0x%x)", pi->cmd);
4730                         err = -EIO;
4731                         goto out;
4732                 }
4733
4734                 c.packets[pi->cmd == P_BITMAP]++;
4735                 c.bytes[pi->cmd == P_BITMAP] += drbd_header_size(connection) + pi->size;
4736
4737                 if (err <= 0) {
4738                         if (err < 0)
4739                                 goto out;
4740                         break;
4741                 }
4742                 err = drbd_recv_header(peer_device->connection, pi);
4743                 if (err)
4744                         goto out;
4745         }
4746
4747         INFO_bm_xfer_stats(device, "receive", &c);
4748
4749         if (device->state.conn == C_WF_BITMAP_T) {
4750                 enum drbd_state_rv rv;
4751
4752                 err = drbd_send_bitmap(device);
4753                 if (err)
4754                         goto out;
4755                 /* Omit CS_ORDERED with this state transition to avoid deadlocks. */
4756                 rv = _drbd_request_state(device, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE);
4757                 D_ASSERT(device, rv == SS_SUCCESS);
4758         } else if (device->state.conn != C_WF_BITMAP_S) {
4759                 /* admin may have requested C_DISCONNECTING,
4760                  * other threads may have noticed network errors */
4761                 drbd_info(device, "unexpected cstate (%s) in receive_bitmap\n",
4762                     drbd_conn_str(device->state.conn));
4763         }
4764         err = 0;
4765
4766  out:
4767         drbd_bm_unlock(device);
4768         if (!err && device->state.conn == C_WF_BITMAP_S)
4769                 drbd_start_resync(device, C_SYNC_SOURCE);
4770         return err;
4771 }
4772
4773 static int receive_skip(struct drbd_connection *connection, struct packet_info *pi)
4774 {
4775         drbd_warn(connection, "skipping unknown optional packet type %d, l: %d!\n",
4776                  pi->cmd, pi->size);
4777
4778         return ignore_remaining_packet(connection, pi);
4779 }
4780
4781 static int receive_UnplugRemote(struct drbd_connection *connection, struct packet_info *pi)
4782 {
4783         /* Make sure we've acked all the TCP data associated
4784          * with the data requests being unplugged */
4785         drbd_tcp_quickack(connection->data.socket);
4786
4787         return 0;
4788 }
4789
4790 static int receive_out_of_sync(struct drbd_connection *connection, struct packet_info *pi)
4791 {
4792         struct drbd_peer_device *peer_device;
4793         struct drbd_device *device;
4794         struct p_block_desc *p = pi->data;
4795
4796         peer_device = conn_peer_device(connection, pi->vnr);
4797         if (!peer_device)
4798                 return -EIO;
4799         device = peer_device->device;
4800
4801         switch (device->state.conn) {
4802         case C_WF_SYNC_UUID:
4803         case C_WF_BITMAP_T:
4804         case C_BEHIND:
4805                         break;
4806         default:
4807                 drbd_err(device, "ASSERT FAILED cstate = %s, expected: WFSyncUUID|WFBitMapT|Behind\n",
4808                                 drbd_conn_str(device->state.conn));
4809         }
4810
4811         drbd_set_out_of_sync(device, be64_to_cpu(p->sector), be32_to_cpu(p->blksize));
4812
4813         return 0;
4814 }
4815
4816 static int receive_rs_deallocated(struct drbd_connection *connection, struct packet_info *pi)
4817 {
4818         struct drbd_peer_device *peer_device;
4819         struct p_block_desc *p = pi->data;
4820         struct drbd_device *device;
4821         sector_t sector;
4822         int size, err = 0;
4823
4824         peer_device = conn_peer_device(connection, pi->vnr);
4825         if (!peer_device)
4826                 return -EIO;
4827         device = peer_device->device;
4828
4829         sector = be64_to_cpu(p->sector);
4830         size = be32_to_cpu(p->blksize);
4831
4832         dec_rs_pending(device);
4833
4834         if (get_ldev(device)) {
4835                 struct drbd_peer_request *peer_req;
4836                 const int op = REQ_OP_WRITE_ZEROES;
4837
4838                 peer_req = drbd_alloc_peer_req(peer_device, ID_SYNCER, sector,
4839                                                size, 0, GFP_NOIO);
4840                 if (!peer_req) {
4841                         put_ldev(device);
4842                         return -ENOMEM;
4843                 }
4844
4845                 peer_req->w.cb = e_end_resync_block;
4846                 peer_req->submit_jif = jiffies;
4847                 peer_req->flags |= EE_IS_TRIM;
4848
4849                 spin_lock_irq(&device->resource->req_lock);
4850                 list_add_tail(&peer_req->w.list, &device->sync_ee);
4851                 spin_unlock_irq(&device->resource->req_lock);
4852
4853                 atomic_add(pi->size >> 9, &device->rs_sect_ev);
4854                 err = drbd_submit_peer_request(device, peer_req, op, 0, DRBD_FAULT_RS_WR);
4855
4856                 if (err) {
4857                         spin_lock_irq(&device->resource->req_lock);
4858                         list_del(&peer_req->w.list);
4859                         spin_unlock_irq(&device->resource->req_lock);
4860
4861                         drbd_free_peer_req(device, peer_req);
4862                         put_ldev(device);
4863                         err = 0;
4864                         goto fail;
4865                 }
4866
4867                 inc_unacked(device);
4868
4869                 /* No put_ldev() here. Gets called in drbd_endio_write_sec_final(),
4870                    as well as drbd_rs_complete_io() */
4871         } else {
4872         fail:
4873                 drbd_rs_complete_io(device, sector);
4874                 drbd_send_ack_ex(peer_device, P_NEG_ACK, sector, size, ID_SYNCER);
4875         }
4876
4877         atomic_add(size >> 9, &device->rs_sect_in);
4878
4879         return err;
4880 }
4881
4882 struct data_cmd {
4883         int expect_payload;
4884         unsigned int pkt_size;
4885         int (*fn)(struct drbd_connection *, struct packet_info *);
4886 };
4887
4888 static struct data_cmd drbd_cmd_handler[] = {
4889         [P_DATA]            = { 1, sizeof(struct p_data), receive_Data },
4890         [P_DATA_REPLY]      = { 1, sizeof(struct p_data), receive_DataReply },
4891         [P_RS_DATA_REPLY]   = { 1, sizeof(struct p_data), receive_RSDataReply } ,
4892         [P_BARRIER]         = { 0, sizeof(struct p_barrier), receive_Barrier } ,
4893         [P_BITMAP]          = { 1, 0, receive_bitmap } ,
4894         [P_COMPRESSED_BITMAP] = { 1, 0, receive_bitmap } ,
4895         [P_UNPLUG_REMOTE]   = { 0, 0, receive_UnplugRemote },
4896         [P_DATA_REQUEST]    = { 0, sizeof(struct p_block_req), receive_DataRequest },
4897         [P_RS_DATA_REQUEST] = { 0, sizeof(struct p_block_req), receive_DataRequest },
4898         [P_SYNC_PARAM]      = { 1, 0, receive_SyncParam },
4899         [P_SYNC_PARAM89]    = { 1, 0, receive_SyncParam },
4900         [P_PROTOCOL]        = { 1, sizeof(struct p_protocol), receive_protocol },
4901         [P_UUIDS]           = { 0, sizeof(struct p_uuids), receive_uuids },
4902         [P_SIZES]           = { 0, sizeof(struct p_sizes), receive_sizes },
4903         [P_STATE]           = { 0, sizeof(struct p_state), receive_state },
4904         [P_STATE_CHG_REQ]   = { 0, sizeof(struct p_req_state), receive_req_state },
4905         [P_SYNC_UUID]       = { 0, sizeof(struct p_rs_uuid), receive_sync_uuid },
4906         [P_OV_REQUEST]      = { 0, sizeof(struct p_block_req), receive_DataRequest },
4907         [P_OV_REPLY]        = { 1, sizeof(struct p_block_req), receive_DataRequest },
4908         [P_CSUM_RS_REQUEST] = { 1, sizeof(struct p_block_req), receive_DataRequest },
4909         [P_RS_THIN_REQ]     = { 0, sizeof(struct p_block_req), receive_DataRequest },
4910         [P_DELAY_PROBE]     = { 0, sizeof(struct p_delay_probe93), receive_skip },
4911         [P_OUT_OF_SYNC]     = { 0, sizeof(struct p_block_desc), receive_out_of_sync },
4912         [P_CONN_ST_CHG_REQ] = { 0, sizeof(struct p_req_state), receive_req_conn_state },
4913         [P_PROTOCOL_UPDATE] = { 1, sizeof(struct p_protocol), receive_protocol },
4914         [P_TRIM]            = { 0, sizeof(struct p_trim), receive_Data },
4915         [P_RS_DEALLOCATED]  = { 0, sizeof(struct p_block_desc), receive_rs_deallocated },
4916         [P_WSAME]           = { 1, sizeof(struct p_wsame), receive_Data },
4917 };
4918
4919 static void drbdd(struct drbd_connection *connection)
4920 {
4921         struct packet_info pi;
4922         size_t shs; /* sub header size */
4923         int err;
4924
4925         while (get_t_state(&connection->receiver) == RUNNING) {
4926                 struct data_cmd const *cmd;
4927
4928                 drbd_thread_current_set_cpu(&connection->receiver);
4929                 update_receiver_timing_details(connection, drbd_recv_header_maybe_unplug);
4930                 if (drbd_recv_header_maybe_unplug(connection, &pi))
4931                         goto err_out;
4932
4933                 cmd = &drbd_cmd_handler[pi.cmd];
4934                 if (unlikely(pi.cmd >= ARRAY_SIZE(drbd_cmd_handler) || !cmd->fn)) {
4935                         drbd_err(connection, "Unexpected data packet %s (0x%04x)",
4936                                  cmdname(pi.cmd), pi.cmd);
4937                         goto err_out;
4938                 }
4939
4940                 shs = cmd->pkt_size;
4941                 if (pi.cmd == P_SIZES && connection->agreed_features & DRBD_FF_WSAME)
4942                         shs += sizeof(struct o_qlim);
4943                 if (pi.size > shs && !cmd->expect_payload) {
4944                         drbd_err(connection, "No payload expected %s l:%d\n",
4945                                  cmdname(pi.cmd), pi.size);
4946                         goto err_out;
4947                 }
4948                 if (pi.size < shs) {
4949                         drbd_err(connection, "%s: unexpected packet size, expected:%d received:%d\n",
4950                                  cmdname(pi.cmd), (int)shs, pi.size);
4951                         goto err_out;
4952                 }
4953
4954                 if (shs) {
4955                         update_receiver_timing_details(connection, drbd_recv_all_warn);
4956                         err = drbd_recv_all_warn(connection, pi.data, shs);
4957                         if (err)
4958                                 goto err_out;
4959                         pi.size -= shs;
4960                 }
4961
4962                 update_receiver_timing_details(connection, cmd->fn);
4963                 err = cmd->fn(connection, &pi);
4964                 if (err) {
4965                         drbd_err(connection, "error receiving %s, e: %d l: %d!\n",
4966                                  cmdname(pi.cmd), err, pi.size);
4967                         goto err_out;
4968                 }
4969         }
4970         return;
4971
4972     err_out:
4973         conn_request_state(connection, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
4974 }
4975
4976 static void conn_disconnect(struct drbd_connection *connection)
4977 {
4978         struct drbd_peer_device *peer_device;
4979         enum drbd_conns oc;
4980         int vnr;
4981
4982         if (connection->cstate == C_STANDALONE)
4983                 return;
4984
4985         /* We are about to start the cleanup after connection loss.
4986          * Make sure drbd_make_request knows about that.
4987          * Usually we should be in some network failure state already,
4988          * but just in case we are not, we fix it up here.
4989          */
4990         conn_request_state(connection, NS(conn, C_NETWORK_FAILURE), CS_HARD);
4991
4992         /* ack_receiver does not clean up anything. it must not interfere, either */
4993         drbd_thread_stop(&connection->ack_receiver);
4994         if (connection->ack_sender) {
4995                 destroy_workqueue(connection->ack_sender);
4996                 connection->ack_sender = NULL;
4997         }
4998         drbd_free_sock(connection);
4999
5000         rcu_read_lock();
5001         idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
5002                 struct drbd_device *device = peer_device->device;
5003                 kref_get(&device->kref);
5004                 rcu_read_unlock();
5005                 drbd_disconnected(peer_device);
5006                 kref_put(&device->kref, drbd_destroy_device);
5007                 rcu_read_lock();
5008         }
5009         rcu_read_unlock();
5010
5011         if (!list_empty(&connection->current_epoch->list))
5012                 drbd_err(connection, "ASSERTION FAILED: connection->current_epoch->list not empty\n");
5013         /* ok, no more ee's on the fly, it is safe to reset the epoch_size */
5014         atomic_set(&connection->current_epoch->epoch_size, 0);
5015         connection->send.seen_any_write_yet = false;
5016
5017         drbd_info(connection, "Connection closed\n");
5018
5019         if (conn_highest_role(connection) == R_PRIMARY && conn_highest_pdsk(connection) >= D_UNKNOWN)
5020                 conn_try_outdate_peer_async(connection);
5021
5022         spin_lock_irq(&connection->resource->req_lock);
5023         oc = connection->cstate;
5024         if (oc >= C_UNCONNECTED)
5025                 _conn_request_state(connection, NS(conn, C_UNCONNECTED), CS_VERBOSE);
5026
5027         spin_unlock_irq(&connection->resource->req_lock);
5028
5029         if (oc == C_DISCONNECTING)
5030                 conn_request_state(connection, NS(conn, C_STANDALONE), CS_VERBOSE | CS_HARD);
5031 }
5032
5033 static int drbd_disconnected(struct drbd_peer_device *peer_device)
5034 {
5035         struct drbd_device *device = peer_device->device;
5036         unsigned int i;
5037
5038         /* wait for current activity to cease. */
5039         spin_lock_irq(&device->resource->req_lock);
5040         _drbd_wait_ee_list_empty(device, &device->active_ee);
5041         _drbd_wait_ee_list_empty(device, &device->sync_ee);
5042         _drbd_wait_ee_list_empty(device, &device->read_ee);
5043         spin_unlock_irq(&device->resource->req_lock);
5044
5045         /* We do not have data structures that would allow us to
5046          * get the rs_pending_cnt down to 0 again.
5047          *  * On C_SYNC_TARGET we do not have any data structures describing
5048          *    the pending RSDataRequest's we have sent.
5049          *  * On C_SYNC_SOURCE there is no data structure that tracks
5050          *    the P_RS_DATA_REPLY blocks that we sent to the SyncTarget.
5051          *  And no, it is not the sum of the reference counts in the
5052          *  resync_LRU. The resync_LRU tracks the whole operation including
5053          *  the disk-IO, while the rs_pending_cnt only tracks the blocks
5054          *  on the fly. */
5055         drbd_rs_cancel_all(device);
5056         device->rs_total = 0;
5057         device->rs_failed = 0;
5058         atomic_set(&device->rs_pending_cnt, 0);
5059         wake_up(&device->misc_wait);
5060
5061         del_timer_sync(&device->resync_timer);
5062         resync_timer_fn(&device->resync_timer);
5063
5064         /* wait for all w_e_end_data_req, w_e_end_rsdata_req, w_send_barrier,
5065          * w_make_resync_request etc. which may still be on the worker queue
5066          * to be "canceled" */
5067         drbd_flush_workqueue(&peer_device->connection->sender_work);
5068
5069         drbd_finish_peer_reqs(device);
5070
5071         /* This second workqueue flush is necessary, since drbd_finish_peer_reqs()
5072            might have issued a work again. The one before drbd_finish_peer_reqs() is
5073            necessary to reclain net_ee in drbd_finish_peer_reqs(). */
5074         drbd_flush_workqueue(&peer_device->connection->sender_work);
5075
5076         /* need to do it again, drbd_finish_peer_reqs() may have populated it
5077          * again via drbd_try_clear_on_disk_bm(). */
5078         drbd_rs_cancel_all(device);
5079
5080         kfree(device->p_uuid);
5081         device->p_uuid = NULL;
5082
5083         if (!drbd_suspended(device))
5084                 tl_clear(peer_device->connection);
5085
5086         drbd_md_sync(device);
5087
5088         if (get_ldev(device)) {
5089                 drbd_bitmap_io(device, &drbd_bm_write_copy_pages,
5090                                 "write from disconnected", BM_LOCKED_CHANGE_ALLOWED);
5091                 put_ldev(device);
5092         }
5093
5094         /* tcp_close and release of sendpage pages can be deferred.  I don't
5095          * want to use SO_LINGER, because apparently it can be deferred for
5096          * more than 20 seconds (longest time I checked).
5097          *
5098          * Actually we don't care for exactly when the network stack does its
5099          * put_page(), but release our reference on these pages right here.
5100          */
5101         i = drbd_free_peer_reqs(device, &device->net_ee);
5102         if (i)
5103                 drbd_info(device, "net_ee not empty, killed %u entries\n", i);
5104         i = atomic_read(&device->pp_in_use_by_net);
5105         if (i)
5106                 drbd_info(device, "pp_in_use_by_net = %d, expected 0\n", i);
5107         i = atomic_read(&device->pp_in_use);
5108         if (i)
5109                 drbd_info(device, "pp_in_use = %d, expected 0\n", i);
5110
5111         D_ASSERT(device, list_empty(&device->read_ee));
5112         D_ASSERT(device, list_empty(&device->active_ee));
5113         D_ASSERT(device, list_empty(&device->sync_ee));
5114         D_ASSERT(device, list_empty(&device->done_ee));
5115
5116         return 0;
5117 }
5118
5119 /*
5120  * We support PRO_VERSION_MIN to PRO_VERSION_MAX. The protocol version
5121  * we can agree on is stored in agreed_pro_version.
5122  *
5123  * feature flags and the reserved array should be enough room for future
5124  * enhancements of the handshake protocol, and possible plugins...
5125  *
5126  * for now, they are expected to be zero, but ignored.
5127  */
5128 static int drbd_send_features(struct drbd_connection *connection)
5129 {
5130         struct drbd_socket *sock;
5131         struct p_connection_features *p;
5132
5133         sock = &connection->data;
5134         p = conn_prepare_command(connection, sock);
5135         if (!p)
5136                 return -EIO;
5137         memset(p, 0, sizeof(*p));
5138         p->protocol_min = cpu_to_be32(PRO_VERSION_MIN);
5139         p->protocol_max = cpu_to_be32(PRO_VERSION_MAX);
5140         p->feature_flags = cpu_to_be32(PRO_FEATURES);
5141         return conn_send_command(connection, sock, P_CONNECTION_FEATURES, sizeof(*p), NULL, 0);
5142 }
5143
5144 /*
5145  * return values:
5146  *   1 yes, we have a valid connection
5147  *   0 oops, did not work out, please try again
5148  *  -1 peer talks different language,
5149  *     no point in trying again, please go standalone.
5150  */
5151 static int drbd_do_features(struct drbd_connection *connection)
5152 {
5153         /* ASSERT current == connection->receiver ... */
5154         struct p_connection_features *p;
5155         const int expect = sizeof(struct p_connection_features);
5156         struct packet_info pi;
5157         int err;
5158
5159         err = drbd_send_features(connection);
5160         if (err)
5161                 return 0;
5162
5163         err = drbd_recv_header(connection, &pi);
5164         if (err)
5165                 return 0;
5166
5167         if (pi.cmd != P_CONNECTION_FEATURES) {
5168                 drbd_err(connection, "expected ConnectionFeatures packet, received: %s (0x%04x)\n",
5169                          cmdname(pi.cmd), pi.cmd);
5170                 return -1;
5171         }
5172
5173         if (pi.size != expect) {
5174                 drbd_err(connection, "expected ConnectionFeatures length: %u, received: %u\n",
5175                      expect, pi.size);
5176                 return -1;
5177         }
5178
5179         p = pi.data;
5180         err = drbd_recv_all_warn(connection, p, expect);
5181         if (err)
5182                 return 0;
5183
5184         p->protocol_min = be32_to_cpu(p->protocol_min);
5185         p->protocol_max = be32_to_cpu(p->protocol_max);
5186         if (p->protocol_max == 0)
5187                 p->protocol_max = p->protocol_min;
5188
5189         if (PRO_VERSION_MAX < p->protocol_min ||
5190             PRO_VERSION_MIN > p->protocol_max)
5191                 goto incompat;
5192
5193         connection->agreed_pro_version = min_t(int, PRO_VERSION_MAX, p->protocol_max);
5194         connection->agreed_features = PRO_FEATURES & be32_to_cpu(p->feature_flags);
5195
5196         drbd_info(connection, "Handshake successful: "
5197              "Agreed network protocol version %d\n", connection->agreed_pro_version);
5198
5199         drbd_info(connection, "Feature flags enabled on protocol level: 0x%x%s%s%s.\n",
5200                   connection->agreed_features,
5201                   connection->agreed_features & DRBD_FF_TRIM ? " TRIM" : "",
5202                   connection->agreed_features & DRBD_FF_THIN_RESYNC ? " THIN_RESYNC" : "",
5203                   connection->agreed_features & DRBD_FF_WSAME ? " WRITE_SAME" :
5204                   connection->agreed_features ? "" : " none");
5205
5206         return 1;
5207
5208  incompat:
5209         drbd_err(connection, "incompatible DRBD dialects: "
5210             "I support %d-%d, peer supports %d-%d\n",
5211             PRO_VERSION_MIN, PRO_VERSION_MAX,
5212             p->protocol_min, p->protocol_max);
5213         return -1;
5214 }
5215
5216 #if !defined(CONFIG_CRYPTO_HMAC) && !defined(CONFIG_CRYPTO_HMAC_MODULE)
5217 static int drbd_do_auth(struct drbd_connection *connection)
5218 {
5219         drbd_err(connection, "This kernel was build without CONFIG_CRYPTO_HMAC.\n");
5220         drbd_err(connection, "You need to disable 'cram-hmac-alg' in drbd.conf.\n");
5221         return -1;
5222 }
5223 #else
5224 #define CHALLENGE_LEN 64
5225
5226 /* Return value:
5227         1 - auth succeeded,
5228         0 - failed, try again (network error),
5229         -1 - auth failed, don't try again.
5230 */
5231
5232 static int drbd_do_auth(struct drbd_connection *connection)
5233 {
5234         struct drbd_socket *sock;
5235         char my_challenge[CHALLENGE_LEN];  /* 64 Bytes... */
5236         char *response = NULL;
5237         char *right_response = NULL;
5238         char *peers_ch = NULL;
5239         unsigned int key_len;
5240         char secret[SHARED_SECRET_MAX]; /* 64 byte */
5241         unsigned int resp_size;
5242         SHASH_DESC_ON_STACK(desc, connection->cram_hmac_tfm);
5243         struct packet_info pi;
5244         struct net_conf *nc;
5245         int err, rv;
5246
5247         /* FIXME: Put the challenge/response into the preallocated socket buffer.  */
5248
5249         rcu_read_lock();
5250         nc = rcu_dereference(connection->net_conf);
5251         key_len = strlen(nc->shared_secret);
5252         memcpy(secret, nc->shared_secret, key_len);
5253         rcu_read_unlock();
5254
5255         desc->tfm = connection->cram_hmac_tfm;
5256         desc->flags = 0;
5257
5258         rv = crypto_shash_setkey(connection->cram_hmac_tfm, (u8 *)secret, key_len);
5259         if (rv) {
5260                 drbd_err(connection, "crypto_shash_setkey() failed with %d\n", rv);
5261                 rv = -1;
5262                 goto fail;
5263         }
5264
5265         get_random_bytes(my_challenge, CHALLENGE_LEN);
5266
5267         sock = &connection->data;
5268         if (!conn_prepare_command(connection, sock)) {
5269                 rv = 0;
5270                 goto fail;
5271         }
5272         rv = !conn_send_command(connection, sock, P_AUTH_CHALLENGE, 0,
5273                                 my_challenge, CHALLENGE_LEN);
5274         if (!rv)
5275                 goto fail;
5276
5277         err = drbd_recv_header(connection, &pi);
5278         if (err) {
5279                 rv = 0;
5280                 goto fail;
5281         }
5282
5283         if (pi.cmd != P_AUTH_CHALLENGE) {
5284                 drbd_err(connection, "expected AuthChallenge packet, received: %s (0x%04x)\n",
5285                          cmdname(pi.cmd), pi.cmd);
5286                 rv = 0;
5287                 goto fail;
5288         }
5289
5290         if (pi.size > CHALLENGE_LEN * 2) {
5291                 drbd_err(connection, "expected AuthChallenge payload too big.\n");
5292                 rv = -1;
5293                 goto fail;
5294         }
5295
5296         if (pi.size < CHALLENGE_LEN) {
5297                 drbd_err(connection, "AuthChallenge payload too small.\n");
5298                 rv = -1;
5299                 goto fail;
5300         }
5301
5302         peers_ch = kmalloc(pi.size, GFP_NOIO);
5303         if (peers_ch == NULL) {
5304                 drbd_err(connection, "kmalloc of peers_ch failed\n");
5305                 rv = -1;
5306                 goto fail;
5307         }
5308
5309         err = drbd_recv_all_warn(connection, peers_ch, pi.size);
5310         if (err) {
5311                 rv = 0;
5312                 goto fail;
5313         }
5314
5315         if (!memcmp(my_challenge, peers_ch, CHALLENGE_LEN)) {
5316                 drbd_err(connection, "Peer presented the same challenge!\n");
5317                 rv = -1;
5318                 goto fail;
5319         }
5320
5321         resp_size = crypto_shash_digestsize(connection->cram_hmac_tfm);
5322         response = kmalloc(resp_size, GFP_NOIO);
5323         if (response == NULL) {
5324                 drbd_err(connection, "kmalloc of response failed\n");
5325                 rv = -1;
5326                 goto fail;
5327         }
5328
5329         rv = crypto_shash_digest(desc, peers_ch, pi.size, response);
5330         if (rv) {
5331                 drbd_err(connection, "crypto_hash_digest() failed with %d\n", rv);
5332                 rv = -1;
5333                 goto fail;
5334         }
5335
5336         if (!conn_prepare_command(connection, sock)) {
5337                 rv = 0;
5338                 goto fail;
5339         }
5340         rv = !conn_send_command(connection, sock, P_AUTH_RESPONSE, 0,
5341                                 response, resp_size);
5342         if (!rv)
5343                 goto fail;
5344
5345         err = drbd_recv_header(connection, &pi);
5346         if (err) {
5347                 rv = 0;
5348                 goto fail;
5349         }
5350
5351         if (pi.cmd != P_AUTH_RESPONSE) {
5352                 drbd_err(connection, "expected AuthResponse packet, received: %s (0x%04x)\n",
5353                          cmdname(pi.cmd), pi.cmd);
5354                 rv = 0;
5355                 goto fail;
5356         }
5357
5358         if (pi.size != resp_size) {
5359                 drbd_err(connection, "expected AuthResponse payload of wrong size\n");
5360                 rv = 0;
5361                 goto fail;
5362         }
5363
5364         err = drbd_recv_all_warn(connection, response , resp_size);
5365         if (err) {
5366                 rv = 0;
5367                 goto fail;
5368         }
5369
5370         right_response = kmalloc(resp_size, GFP_NOIO);
5371         if (right_response == NULL) {
5372                 drbd_err(connection, "kmalloc of right_response failed\n");
5373                 rv = -1;
5374                 goto fail;
5375         }
5376
5377         rv = crypto_shash_digest(desc, my_challenge, CHALLENGE_LEN,
5378                                  right_response);
5379         if (rv) {
5380                 drbd_err(connection, "crypto_hash_digest() failed with %d\n", rv);
5381                 rv = -1;
5382                 goto fail;
5383         }
5384
5385         rv = !memcmp(response, right_response, resp_size);
5386
5387         if (rv)
5388                 drbd_info(connection, "Peer authenticated using %d bytes HMAC\n",
5389                      resp_size);
5390         else
5391                 rv = -1;
5392
5393  fail:
5394         kfree(peers_ch);
5395         kfree(response);
5396         kfree(right_response);
5397         shash_desc_zero(desc);
5398
5399         return rv;
5400 }
5401 #endif
5402
5403 int drbd_receiver(struct drbd_thread *thi)
5404 {
5405         struct drbd_connection *connection = thi->connection;
5406         int h;
5407
5408         drbd_info(connection, "receiver (re)started\n");
5409
5410         do {
5411                 h = conn_connect(connection);
5412                 if (h == 0) {
5413                         conn_disconnect(connection);
5414                         schedule_timeout_interruptible(HZ);
5415                 }
5416                 if (h == -1) {
5417                         drbd_warn(connection, "Discarding network configuration.\n");
5418                         conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD);
5419                 }
5420         } while (h == 0);
5421
5422         if (h > 0) {
5423                 blk_start_plug(&connection->receiver_plug);
5424                 drbdd(connection);
5425                 blk_finish_plug(&connection->receiver_plug);
5426         }
5427
5428         conn_disconnect(connection);
5429
5430         drbd_info(connection, "receiver terminated\n");
5431         return 0;
5432 }
5433
5434 /* ********* acknowledge sender ******** */
5435
5436 static int got_conn_RqSReply(struct drbd_connection *connection, struct packet_info *pi)
5437 {
5438         struct p_req_state_reply *p = pi->data;
5439         int retcode = be32_to_cpu(p->retcode);
5440
5441         if (retcode >= SS_SUCCESS) {
5442                 set_bit(CONN_WD_ST_CHG_OKAY, &connection->flags);
5443         } else {
5444                 set_bit(CONN_WD_ST_CHG_FAIL, &connection->flags);
5445                 drbd_err(connection, "Requested state change failed by peer: %s (%d)\n",
5446                          drbd_set_st_err_str(retcode), retcode);
5447         }
5448         wake_up(&connection->ping_wait);
5449
5450         return 0;
5451 }
5452
5453 static int got_RqSReply(struct drbd_connection *connection, struct packet_info *pi)
5454 {
5455         struct drbd_peer_device *peer_device;
5456         struct drbd_device *device;
5457         struct p_req_state_reply *p = pi->data;
5458         int retcode = be32_to_cpu(p->retcode);
5459
5460         peer_device = conn_peer_device(connection, pi->vnr);
5461         if (!peer_device)
5462                 return -EIO;
5463         device = peer_device->device;
5464
5465         if (test_bit(CONN_WD_ST_CHG_REQ, &connection->flags)) {
5466                 D_ASSERT(device, connection->agreed_pro_version < 100);
5467                 return got_conn_RqSReply(connection, pi);
5468         }
5469
5470         if (retcode >= SS_SUCCESS) {
5471                 set_bit(CL_ST_CHG_SUCCESS, &device->flags);
5472         } else {
5473                 set_bit(CL_ST_CHG_FAIL, &device->flags);
5474                 drbd_err(device, "Requested state change failed by peer: %s (%d)\n",
5475                         drbd_set_st_err_str(retcode), retcode);
5476         }
5477         wake_up(&device->state_wait);
5478
5479         return 0;
5480 }
5481
5482 static int got_Ping(struct drbd_connection *connection, struct packet_info *pi)
5483 {
5484         return drbd_send_ping_ack(connection);
5485
5486 }
5487
5488 static int got_PingAck(struct drbd_connection *connection, struct packet_info *pi)
5489 {
5490         /* restore idle timeout */
5491         connection->meta.socket->sk->sk_rcvtimeo = connection->net_conf->ping_int*HZ;
5492         if (!test_and_set_bit(GOT_PING_ACK, &connection->flags))
5493                 wake_up(&connection->ping_wait);
5494
5495         return 0;
5496 }
5497
5498 static int got_IsInSync(struct drbd_connection *connection, struct packet_info *pi)
5499 {
5500         struct drbd_peer_device *peer_device;
5501         struct drbd_device *device;
5502         struct p_block_ack *p = pi->data;
5503         sector_t sector = be64_to_cpu(p->sector);
5504         int blksize = be32_to_cpu(p->blksize);
5505
5506         peer_device = conn_peer_device(connection, pi->vnr);
5507         if (!peer_device)
5508                 return -EIO;
5509         device = peer_device->device;
5510
5511         D_ASSERT(device, peer_device->connection->agreed_pro_version >= 89);
5512
5513         update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
5514
5515         if (get_ldev(device)) {
5516                 drbd_rs_complete_io(device, sector);
5517                 drbd_set_in_sync(device, sector, blksize);
5518                 /* rs_same_csums is supposed to count in units of BM_BLOCK_SIZE */
5519                 device->rs_same_csum += (blksize >> BM_BLOCK_SHIFT);
5520                 put_ldev(device);
5521         }
5522         dec_rs_pending(device);
5523         atomic_add(blksize >> 9, &device->rs_sect_in);
5524
5525         return 0;
5526 }
5527
5528 static int
5529 validate_req_change_req_state(struct drbd_device *device, u64 id, sector_t sector,
5530                               struct rb_root *root, const char *func,
5531                               enum drbd_req_event what, bool missing_ok)
5532 {
5533         struct drbd_request *req;
5534         struct bio_and_error m;
5535
5536         spin_lock_irq(&device->resource->req_lock);
5537         req = find_request(device, root, id, sector, missing_ok, func);
5538         if (unlikely(!req)) {
5539                 spin_unlock_irq(&device->resource->req_lock);
5540                 return -EIO;
5541         }
5542         __req_mod(req, what, &m);
5543         spin_unlock_irq(&device->resource->req_lock);
5544
5545         if (m.bio)
5546                 complete_master_bio(device, &m);
5547         return 0;
5548 }
5549
5550 static int got_BlockAck(struct drbd_connection *connection, struct packet_info *pi)
5551 {
5552         struct drbd_peer_device *peer_device;
5553         struct drbd_device *device;
5554         struct p_block_ack *p = pi->data;
5555         sector_t sector = be64_to_cpu(p->sector);
5556         int blksize = be32_to_cpu(p->blksize);
5557         enum drbd_req_event what;
5558
5559         peer_device = conn_peer_device(connection, pi->vnr);
5560         if (!peer_device)
5561                 return -EIO;
5562         device = peer_device->device;
5563
5564         update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
5565
5566         if (p->block_id == ID_SYNCER) {
5567                 drbd_set_in_sync(device, sector, blksize);
5568                 dec_rs_pending(device);
5569                 return 0;
5570         }
5571         switch (pi->cmd) {
5572         case P_RS_WRITE_ACK:
5573                 what = WRITE_ACKED_BY_PEER_AND_SIS;
5574                 break;
5575         case P_WRITE_ACK:
5576                 what = WRITE_ACKED_BY_PEER;
5577                 break;
5578         case P_RECV_ACK:
5579                 what = RECV_ACKED_BY_PEER;
5580                 break;
5581         case P_SUPERSEDED:
5582                 what = CONFLICT_RESOLVED;
5583                 break;
5584         case P_RETRY_WRITE:
5585                 what = POSTPONE_WRITE;
5586                 break;
5587         default:
5588                 BUG();
5589         }
5590
5591         return validate_req_change_req_state(device, p->block_id, sector,
5592                                              &device->write_requests, __func__,
5593                                              what, false);
5594 }
5595
5596 static int got_NegAck(struct drbd_connection *connection, struct packet_info *pi)
5597 {
5598         struct drbd_peer_device *peer_device;
5599         struct drbd_device *device;
5600         struct p_block_ack *p = pi->data;
5601         sector_t sector = be64_to_cpu(p->sector);
5602         int size = be32_to_cpu(p->blksize);
5603         int err;
5604
5605         peer_device = conn_peer_device(connection, pi->vnr);
5606         if (!peer_device)
5607                 return -EIO;
5608         device = peer_device->device;
5609
5610         update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
5611
5612         if (p->block_id == ID_SYNCER) {
5613                 dec_rs_pending(device);
5614                 drbd_rs_failed_io(device, sector, size);
5615                 return 0;
5616         }
5617
5618         err = validate_req_change_req_state(device, p->block_id, sector,
5619                                             &device->write_requests, __func__,
5620                                             NEG_ACKED, true);
5621         if (err) {
5622                 /* Protocol A has no P_WRITE_ACKs, but has P_NEG_ACKs.
5623                    The master bio might already be completed, therefore the
5624                    request is no longer in the collision hash. */
5625                 /* In Protocol B we might already have got a P_RECV_ACK
5626                    but then get a P_NEG_ACK afterwards. */
5627                 drbd_set_out_of_sync(device, sector, size);
5628         }
5629         return 0;
5630 }
5631
5632 static int got_NegDReply(struct drbd_connection *connection, struct packet_info *pi)
5633 {
5634         struct drbd_peer_device *peer_device;
5635         struct drbd_device *device;
5636         struct p_block_ack *p = pi->data;
5637         sector_t sector = be64_to_cpu(p->sector);
5638
5639         peer_device = conn_peer_device(connection, pi->vnr);
5640         if (!peer_device)
5641                 return -EIO;
5642         device = peer_device->device;
5643
5644         update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
5645
5646         drbd_err(device, "Got NegDReply; Sector %llus, len %u.\n",
5647             (unsigned long long)sector, be32_to_cpu(p->blksize));
5648
5649         return validate_req_change_req_state(device, p->block_id, sector,
5650                                              &device->read_requests, __func__,
5651                                              NEG_ACKED, false);
5652 }
5653
5654 static int got_NegRSDReply(struct drbd_connection *connection, struct packet_info *pi)
5655 {
5656         struct drbd_peer_device *peer_device;
5657         struct drbd_device *device;
5658         sector_t sector;
5659         int size;
5660         struct p_block_ack *p = pi->data;
5661
5662         peer_device = conn_peer_device(connection, pi->vnr);
5663         if (!peer_device)
5664                 return -EIO;
5665         device = peer_device->device;
5666
5667         sector = be64_to_cpu(p->sector);
5668         size = be32_to_cpu(p->blksize);
5669
5670         update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
5671
5672         dec_rs_pending(device);
5673
5674         if (get_ldev_if_state(device, D_FAILED)) {
5675                 drbd_rs_complete_io(device, sector);
5676                 switch (pi->cmd) {
5677                 case P_NEG_RS_DREPLY:
5678                         drbd_rs_failed_io(device, sector, size);
5679                 case P_RS_CANCEL:
5680                         break;
5681                 default:
5682                         BUG();
5683                 }
5684                 put_ldev(device);
5685         }
5686
5687         return 0;
5688 }
5689
5690 static int got_BarrierAck(struct drbd_connection *connection, struct packet_info *pi)
5691 {
5692         struct p_barrier_ack *p = pi->data;
5693         struct drbd_peer_device *peer_device;
5694         int vnr;
5695
5696         tl_release(connection, p->barrier, be32_to_cpu(p->set_size));
5697
5698         rcu_read_lock();
5699         idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
5700                 struct drbd_device *device = peer_device->device;
5701
5702                 if (device->state.conn == C_AHEAD &&
5703                     atomic_read(&device->ap_in_flight) == 0 &&
5704                     !test_and_set_bit(AHEAD_TO_SYNC_SOURCE, &device->flags)) {
5705                         device->start_resync_timer.expires = jiffies + HZ;
5706                         add_timer(&device->start_resync_timer);
5707                 }
5708         }
5709         rcu_read_unlock();
5710
5711         return 0;
5712 }
5713
5714 static int got_OVResult(struct drbd_connection *connection, struct packet_info *pi)
5715 {
5716         struct drbd_peer_device *peer_device;
5717         struct drbd_device *device;
5718         struct p_block_ack *p = pi->data;
5719         struct drbd_device_work *dw;
5720         sector_t sector;
5721         int size;
5722
5723         peer_device = conn_peer_device(connection, pi->vnr);
5724         if (!peer_device)
5725                 return -EIO;
5726         device = peer_device->device;
5727
5728         sector = be64_to_cpu(p->sector);
5729         size = be32_to_cpu(p->blksize);
5730
5731         update_peer_seq(peer_device, be32_to_cpu(p->seq_num));
5732
5733         if (be64_to_cpu(p->block_id) == ID_OUT_OF_SYNC)
5734                 drbd_ov_out_of_sync_found(device, sector, size);
5735         else
5736                 ov_out_of_sync_print(device);
5737
5738         if (!get_ldev(device))
5739                 return 0;
5740
5741         drbd_rs_complete_io(device, sector);
5742         dec_rs_pending(device);
5743
5744         --device->ov_left;
5745
5746         /* let's advance progress step marks only for every other megabyte */
5747         if ((device->ov_left & 0x200) == 0x200)
5748                 drbd_advance_rs_marks(device, device->ov_left);
5749
5750         if (device->ov_left == 0) {
5751                 dw = kmalloc(sizeof(*dw), GFP_NOIO);
5752                 if (dw) {
5753                         dw->w.cb = w_ov_finished;
5754                         dw->device = device;
5755                         drbd_queue_work(&peer_device->connection->sender_work, &dw->w);
5756                 } else {
5757                         drbd_err(device, "kmalloc(dw) failed.");
5758                         ov_out_of_sync_print(device);
5759                         drbd_resync_finished(device);
5760                 }
5761         }
5762         put_ldev(device);
5763         return 0;
5764 }
5765
5766 static int got_skip(struct drbd_connection *connection, struct packet_info *pi)
5767 {
5768         return 0;
5769 }
5770
5771 struct meta_sock_cmd {
5772         size_t pkt_size;
5773         int (*fn)(struct drbd_connection *connection, struct packet_info *);
5774 };
5775
5776 static void set_rcvtimeo(struct drbd_connection *connection, bool ping_timeout)
5777 {
5778         long t;
5779         struct net_conf *nc;
5780
5781         rcu_read_lock();
5782         nc = rcu_dereference(connection->net_conf);
5783         t = ping_timeout ? nc->ping_timeo : nc->ping_int;
5784         rcu_read_unlock();
5785
5786         t *= HZ;
5787         if (ping_timeout)
5788                 t /= 10;
5789
5790         connection->meta.socket->sk->sk_rcvtimeo = t;
5791 }
5792
5793 static void set_ping_timeout(struct drbd_connection *connection)
5794 {
5795         set_rcvtimeo(connection, 1);
5796 }
5797
5798 static void set_idle_timeout(struct drbd_connection *connection)
5799 {
5800         set_rcvtimeo(connection, 0);
5801 }
5802
5803 static struct meta_sock_cmd ack_receiver_tbl[] = {
5804         [P_PING]            = { 0, got_Ping },
5805         [P_PING_ACK]        = { 0, got_PingAck },
5806         [P_RECV_ACK]        = { sizeof(struct p_block_ack), got_BlockAck },
5807         [P_WRITE_ACK]       = { sizeof(struct p_block_ack), got_BlockAck },
5808         [P_RS_WRITE_ACK]    = { sizeof(struct p_block_ack), got_BlockAck },
5809         [P_SUPERSEDED]   = { sizeof(struct p_block_ack), got_BlockAck },
5810         [P_NEG_ACK]         = { sizeof(struct p_block_ack), got_NegAck },
5811         [P_NEG_DREPLY]      = { sizeof(struct p_block_ack), got_NegDReply },
5812         [P_NEG_RS_DREPLY]   = { sizeof(struct p_block_ack), got_NegRSDReply },
5813         [P_OV_RESULT]       = { sizeof(struct p_block_ack), got_OVResult },
5814         [P_BARRIER_ACK]     = { sizeof(struct p_barrier_ack), got_BarrierAck },
5815         [P_STATE_CHG_REPLY] = { sizeof(struct p_req_state_reply), got_RqSReply },
5816         [P_RS_IS_IN_SYNC]   = { sizeof(struct p_block_ack), got_IsInSync },
5817         [P_DELAY_PROBE]     = { sizeof(struct p_delay_probe93), got_skip },
5818         [P_RS_CANCEL]       = { sizeof(struct p_block_ack), got_NegRSDReply },
5819         [P_CONN_ST_CHG_REPLY]={ sizeof(struct p_req_state_reply), got_conn_RqSReply },
5820         [P_RETRY_WRITE]     = { sizeof(struct p_block_ack), got_BlockAck },
5821 };
5822
5823 int drbd_ack_receiver(struct drbd_thread *thi)
5824 {
5825         struct drbd_connection *connection = thi->connection;
5826         struct meta_sock_cmd *cmd = NULL;
5827         struct packet_info pi;
5828         unsigned long pre_recv_jif;
5829         int rv;
5830         void *buf    = connection->meta.rbuf;
5831         int received = 0;
5832         unsigned int header_size = drbd_header_size(connection);
5833         int expect   = header_size;
5834         bool ping_timeout_active = false;
5835         struct sched_param param = { .sched_priority = 2 };
5836
5837         rv = sched_setscheduler(current, SCHED_RR, &param);
5838         if (rv < 0)
5839                 drbd_err(connection, "drbd_ack_receiver: ERROR set priority, ret=%d\n", rv);
5840
5841         while (get_t_state(thi) == RUNNING) {
5842                 drbd_thread_current_set_cpu(thi);
5843
5844                 conn_reclaim_net_peer_reqs(connection);
5845
5846                 if (test_and_clear_bit(SEND_PING, &connection->flags)) {
5847                         if (drbd_send_ping(connection)) {
5848                                 drbd_err(connection, "drbd_send_ping has failed\n");
5849                                 goto reconnect;
5850                         }
5851                         set_ping_timeout(connection);
5852                         ping_timeout_active = true;
5853                 }
5854
5855                 pre_recv_jif = jiffies;
5856                 rv = drbd_recv_short(connection->meta.socket, buf, expect-received, 0);
5857
5858                 /* Note:
5859                  * -EINTR        (on meta) we got a signal
5860                  * -EAGAIN       (on meta) rcvtimeo expired
5861                  * -ECONNRESET   other side closed the connection
5862                  * -ERESTARTSYS  (on data) we got a signal
5863                  * rv <  0       other than above: unexpected error!
5864                  * rv == expected: full header or command
5865                  * rv <  expected: "woken" by signal during receive
5866                  * rv == 0       : "connection shut down by peer"
5867                  */
5868                 if (likely(rv > 0)) {
5869                         received += rv;
5870                         buf      += rv;
5871                 } else if (rv == 0) {
5872                         if (test_bit(DISCONNECT_SENT, &connection->flags)) {
5873                                 long t;
5874                                 rcu_read_lock();
5875                                 t = rcu_dereference(connection->net_conf)->ping_timeo * HZ/10;
5876                                 rcu_read_unlock();
5877
5878                                 t = wait_event_timeout(connection->ping_wait,
5879                                                        connection->cstate < C_WF_REPORT_PARAMS,
5880                                                        t);
5881                                 if (t)
5882                                         break;
5883                         }
5884                         drbd_err(connection, "meta connection shut down by peer.\n");
5885                         goto reconnect;
5886                 } else if (rv == -EAGAIN) {
5887                         /* If the data socket received something meanwhile,
5888                          * that is good enough: peer is still alive. */
5889                         if (time_after(connection->last_received, pre_recv_jif))
5890                                 continue;
5891                         if (ping_timeout_active) {
5892                                 drbd_err(connection, "PingAck did not arrive in time.\n");
5893                                 goto reconnect;
5894                         }
5895                         set_bit(SEND_PING, &connection->flags);
5896                         continue;
5897                 } else if (rv == -EINTR) {
5898                         /* maybe drbd_thread_stop(): the while condition will notice.
5899                          * maybe woken for send_ping: we'll send a ping above,
5900                          * and change the rcvtimeo */
5901                         flush_signals(current);
5902                         continue;
5903                 } else {
5904                         drbd_err(connection, "sock_recvmsg returned %d\n", rv);
5905                         goto reconnect;
5906                 }
5907
5908                 if (received == expect && cmd == NULL) {
5909                         if (decode_header(connection, connection->meta.rbuf, &pi))
5910                                 goto reconnect;
5911                         cmd = &ack_receiver_tbl[pi.cmd];
5912                         if (pi.cmd >= ARRAY_SIZE(ack_receiver_tbl) || !cmd->fn) {
5913                                 drbd_err(connection, "Unexpected meta packet %s (0x%04x)\n",
5914                                          cmdname(pi.cmd), pi.cmd);
5915                                 goto disconnect;
5916                         }
5917                         expect = header_size + cmd->pkt_size;
5918                         if (pi.size != expect - header_size) {
5919                                 drbd_err(connection, "Wrong packet size on meta (c: %d, l: %d)\n",
5920                                         pi.cmd, pi.size);
5921                                 goto reconnect;
5922                         }
5923                 }
5924                 if (received == expect) {
5925                         bool err;
5926
5927                         err = cmd->fn(connection, &pi);
5928                         if (err) {
5929                                 drbd_err(connection, "%pf failed\n", cmd->fn);
5930                                 goto reconnect;
5931                         }
5932
5933                         connection->last_received = jiffies;
5934
5935                         if (cmd == &ack_receiver_tbl[P_PING_ACK]) {
5936                                 set_idle_timeout(connection);
5937                                 ping_timeout_active = false;
5938                         }
5939
5940                         buf      = connection->meta.rbuf;
5941                         received = 0;
5942                         expect   = header_size;
5943                         cmd      = NULL;
5944                 }
5945         }
5946
5947         if (0) {
5948 reconnect:
5949                 conn_request_state(connection, NS(conn, C_NETWORK_FAILURE), CS_HARD);
5950                 conn_md_sync(connection);
5951         }
5952         if (0) {
5953 disconnect:
5954                 conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD);
5955         }
5956
5957         drbd_info(connection, "ack_receiver terminated\n");
5958
5959         return 0;
5960 }
5961
5962 void drbd_send_acks_wf(struct work_struct *ws)
5963 {
5964         struct drbd_peer_device *peer_device =
5965                 container_of(ws, struct drbd_peer_device, send_acks_work);
5966         struct drbd_connection *connection = peer_device->connection;
5967         struct drbd_device *device = peer_device->device;
5968         struct net_conf *nc;
5969         int tcp_cork, err;
5970
5971         rcu_read_lock();
5972         nc = rcu_dereference(connection->net_conf);
5973         tcp_cork = nc->tcp_cork;
5974         rcu_read_unlock();
5975
5976         if (tcp_cork)
5977                 drbd_tcp_cork(connection->meta.socket);
5978
5979         err = drbd_finish_peer_reqs(device);
5980         kref_put(&device->kref, drbd_destroy_device);
5981         /* get is in drbd_endio_write_sec_final(). That is necessary to keep the
5982            struct work_struct send_acks_work alive, which is in the peer_device object */
5983
5984         if (err) {
5985                 conn_request_state(connection, NS(conn, C_NETWORK_FAILURE), CS_HARD);
5986                 return;
5987         }
5988
5989         if (tcp_cork)
5990                 drbd_tcp_uncork(connection->meta.socket);
5991
5992         return;
5993 }