drivers/block/drbd/drbd_main.c

   1 /*
   2    drbd.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    Thanks to Carter Burden, Bart Grantham and Gennadiy Nerubayev
  11    from Logicworks, Inc. for making SDP replication support possible.
  12
  13    drbd is free software; you can redistribute it and/or modify
  14    it under the terms of the GNU General Public License as published by
  15    the Free Software Foundation; either version 2, or (at your option)
  16    any later version.
  17
  18    drbd is distributed in the hope that it will be useful,
  19    but WITHOUT ANY WARRANTY; without even the implied warranty of
  20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21    GNU General Public License for more details.
  22
  23    You should have received a copy of the GNU General Public License
  24    along with drbd; see the file COPYING.  If not, write to
  25    the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  26
  27  */
  28
  29 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  30
  31 #include <linux/module.h>
  32 #include <linux/jiffies.h>
  33 #include <linux/drbd.h>
  34 #include <asm/uaccess.h>
  35 #include <asm/types.h>
  36 #include <net/sock.h>
  37 #include <linux/ctype.h>
  38 #include <linux/mutex.h>
  39 #include <linux/fs.h>
  40 #include <linux/file.h>
  41 #include <linux/proc_fs.h>
  42 #include <linux/init.h>
  43 #include <linux/mm.h>
  44 #include <linux/memcontrol.h>
  45 #include <linux/mm_inline.h>
  46 #include <linux/slab.h>
  47 #include <linux/random.h>
  48 #include <linux/reboot.h>
  49 #include <linux/notifier.h>
  50 #include <linux/kthread.h>
  51 #include <linux/workqueue.h>
  52 #define __KERNEL_SYSCALLS__
  53 #include <linux/unistd.h>
  54 #include <linux/vmalloc.h>
  55
  56 #include <linux/drbd_limits.h>
  57 #include "drbd_int.h"
  58 #include "drbd_protocol.h"
  59 #include "drbd_req.h" /* only for _req_mod in tl_release and tl_clear */
  60 #include "drbd_vli.h"
  61 #include "drbd_debugfs.h"
  62
  63 static DEFINE_MUTEX(drbd_main_mutex);
  64 static int drbd_open(struct block_device *bdev, fmode_t mode);
  65 static void drbd_release(struct gendisk *gd, fmode_t mode);
  66 static void md_sync_timer_fn(unsigned long data);
  67 static int w_bitmap_io(struct drbd_work *w, int unused);
  68
  69 MODULE_AUTHOR("Philipp Reisner <phil@linbit.com>, "
  70               "Lars Ellenberg <lars@linbit.com>");
  71 MODULE_DESCRIPTION("drbd - Distributed Replicated Block Device v" REL_VERSION);
  72 MODULE_VERSION(REL_VERSION);
  73 MODULE_LICENSE("GPL");
  74 MODULE_PARM_DESC(minor_count, "Approximate number of drbd devices ("
  75                  __stringify(DRBD_MINOR_COUNT_MIN) "-" __stringify(DRBD_MINOR_COUNT_MAX) ")");
  76 MODULE_ALIAS_BLOCKDEV_MAJOR(DRBD_MAJOR);
  77
  78 #include <linux/moduleparam.h>
  79 /* allow_open_on_secondary */
  80 MODULE_PARM_DESC(allow_oos, "DONT USE!");
  81 /* thanks to these macros, if compiled into the kernel (not-module),
  82  * this becomes the boot parameter drbd.minor_count */
  83 module_param(minor_count, uint, 0444);
  84 module_param(disable_sendpage, bool, 0644);
  85 module_param(allow_oos, bool, 0);
  86 module_param(proc_details, int, 0644);
  87
  88 #ifdef CONFIG_DRBD_FAULT_INJECTION
  89 int enable_faults;
  90 int fault_rate;
  91 static int fault_count;
  92 int fault_devs;
  93 /* bitmap of enabled faults */
  94 module_param(enable_faults, int, 0664);
  95 /* fault rate % value - applies to all enabled faults */
  96 module_param(fault_rate, int, 0664);
  97 /* count of faults inserted */
  98 module_param(fault_count, int, 0664);
  99 /* bitmap of devices to insert faults on */
 100 module_param(fault_devs, int, 0644);
 101 #endif
 102
 103 /* module parameter, defined */
 104 unsigned int minor_count = DRBD_MINOR_COUNT_DEF;
 105 bool disable_sendpage;
 106 bool allow_oos;
 107 int proc_details;       /* Detail level in proc drbd*/
 108
 109 /* Module parameter for setting the user mode helper program
 110  * to run. Default is /sbin/drbdadm */
 111 char usermode_helper[80] = "/sbin/drbdadm";
 112
 113 module_param_string(usermode_helper, usermode_helper, sizeof(usermode_helper), 0644);
 114
 115 /* in 2.6.x, our device mapping and config info contains our virtual gendisks
 116  * as member "struct gendisk *vdisk;"
 117  */
 118 struct idr drbd_devices;
 119 struct list_head drbd_resources;
 120
 121 struct kmem_cache *drbd_request_cache;
 122 struct kmem_cache *drbd_ee_cache;       /* peer requests */
 123 struct kmem_cache *drbd_bm_ext_cache;   /* bitmap extents */
 124 struct kmem_cache *drbd_al_ext_cache;   /* activity log extents */
 125 mempool_t *drbd_request_mempool;
 126 mempool_t *drbd_ee_mempool;
 127 mempool_t *drbd_md_io_page_pool;
 128 struct bio_set *drbd_md_io_bio_set;
 129
 130 /* I do not use a standard mempool, because:
 131    1) I want to hand out the pre-allocated objects first.
 132    2) I want to be able to interrupt sleeping allocation with a signal.
 133    Note: This is a single linked list, the next pointer is the private
 134          member of struct page.
 135  */
 136 struct page *drbd_pp_pool;
 137 spinlock_t   drbd_pp_lock;
 138 int          drbd_pp_vacant;
 139 wait_queue_head_t drbd_pp_wait;
 140
 141 DEFINE_RATELIMIT_STATE(drbd_ratelimit_state, 5 * HZ, 5);
 142
 143 static const struct block_device_operations drbd_ops = {
 144         .owner =   THIS_MODULE,
 145         .open =    drbd_open,
 146         .release = drbd_release,
 147 };
 148
 149 struct bio *bio_alloc_drbd(gfp_t gfp_mask)
 150 {
 151         struct bio *bio;
 152
 153         if (!drbd_md_io_bio_set)
 154                 return bio_alloc(gfp_mask, 1);
 155
 156         bio = bio_alloc_bioset(gfp_mask, 1, drbd_md_io_bio_set);
 157         if (!bio)
 158                 return NULL;
 159         return bio;
 160 }
 161
 162 #ifdef __CHECKER__
 163 /* When checking with sparse, and this is an inline function, sparse will
 164    give tons of false positives. When this is a real functions sparse works.
 165  */
 166 int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins)
 167 {
 168         int io_allowed;
 169
 170         atomic_inc(&device->local_cnt);
 171         io_allowed = (device->state.disk >= mins);
 172         if (!io_allowed) {
 173                 if (atomic_dec_and_test(&device->local_cnt))
 174                         wake_up(&device->misc_wait);
 175         }
 176         return io_allowed;
 177 }
 178
 179 #endif
 180
 181 /**
 182  * tl_release() - mark as BARRIER_ACKED all requests in the corresponding transfer log epoch
 183  * @connection: DRBD connection.
 184  * @barrier_nr: Expected identifier of the DRBD write barrier packet.
 185  * @set_size:   Expected number of requests before that barrier.
 186  *
 187  * In case the passed barrier_nr or set_size does not match the oldest
 188  * epoch of not yet barrier-acked requests, this function will cause a
 189  * termination of the connection.
 190  */
 191 void tl_release(struct drbd_connection *connection, unsigned int barrier_nr,
 192                 unsigned int set_size)
 193 {
 194         struct drbd_request *r;
 195         struct drbd_request *req = NULL;
 196         int expect_epoch = 0;
 197         int expect_size = 0;
 198
 199         spin_lock_irq(&connection->resource->req_lock);
 200
 201         /* find oldest not yet barrier-acked write request,
 202          * count writes in its epoch. */
 203         list_for_each_entry(r, &connection->transfer_log, tl_requests) {
 204                 const unsigned s = r->rq_state;
 205                 if (!req) {
 206                         if (!(s & RQ_WRITE))
 207                                 continue;
 208                         if (!(s & RQ_NET_MASK))
 209                                 continue;
 210                         if (s & RQ_NET_DONE)
 211                                 continue;
 212                         req = r;
 213                         expect_epoch = req->epoch;
 214                         expect_size ++;
 215                 } else {
 216                         if (r->epoch != expect_epoch)
 217                                 break;
 218                         if (!(s & RQ_WRITE))
 219                                 continue;
 220                         /* if (s & RQ_DONE): not expected */
 221                         /* if (!(s & RQ_NET_MASK)): not expected */
 222                         expect_size++;
 223                 }
 224         }
 225
 226         /* first some paranoia code */
 227         if (req == NULL) {
 228                 drbd_err(connection, "BAD! BarrierAck #%u received, but no epoch in tl!?\n",
 229                          barrier_nr);
 230                 goto bail;
 231         }
 232         if (expect_epoch != barrier_nr) {
 233                 drbd_err(connection, "BAD! BarrierAck #%u received, expected #%u!\n",
 234                          barrier_nr, expect_epoch);
 235                 goto bail;
 236         }
 237
 238         if (expect_size != set_size) {
 239                 drbd_err(connection, "BAD! BarrierAck #%u received with n_writes=%u, expected n_writes=%u!\n",
 240                          barrier_nr, set_size, expect_size);
 241                 goto bail;
 242         }
 243
 244         /* Clean up list of requests processed during current epoch. */
 245         /* this extra list walk restart is paranoia,
 246          * to catch requests being barrier-acked "unexpectedly".
 247          * It usually should find the same req again, or some READ preceding it. */
 248         list_for_each_entry(req, &connection->transfer_log, tl_requests)
 249                 if (req->epoch == expect_epoch)
 250                         break;
 251         list_for_each_entry_safe_from(req, r, &connection->transfer_log, tl_requests) {
 252                 if (req->epoch != expect_epoch)
 253                         break;
 254                 _req_mod(req, BARRIER_ACKED);
 255         }
 256         spin_unlock_irq(&connection->resource->req_lock);
 257
 258         return;
 259
 260 bail:
 261         spin_unlock_irq(&connection->resource->req_lock);
 262         conn_request_state(connection, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
 263 }
 264
 265
 266 /**
 267  * _tl_restart() - Walks the transfer log, and applies an action to all requests
 268  * @connection: DRBD connection to operate on.
 269  * @what:       The action/event to perform with all request objects
 270  *
 271  * @what might be one of CONNECTION_LOST_WHILE_PENDING, RESEND, FAIL_FROZEN_DISK_IO,
 272  * RESTART_FROZEN_DISK_IO.
 273  */
 274 /* must hold resource->req_lock */
 275 void _tl_restart(struct drbd_connection *connection, enum drbd_req_event what)
 276 {
 277         struct drbd_request *req, *r;
 278
 279         list_for_each_entry_safe(req, r, &connection->transfer_log, tl_requests)
 280                 _req_mod(req, what);
 281 }
 282
 283 void tl_restart(struct drbd_connection *connection, enum drbd_req_event what)
 284 {
 285         spin_lock_irq(&connection->resource->req_lock);
 286         _tl_restart(connection, what);
 287         spin_unlock_irq(&connection->resource->req_lock);
 288 }
 289
 290 /**
 291  * tl_clear() - Clears all requests and &struct drbd_tl_epoch objects out of the TL
 292  * @device:     DRBD device.
 293  *
 294  * This is called after the connection to the peer was lost. The storage covered
 295  * by the requests on the transfer gets marked as our of sync. Called from the
 296  * receiver thread and the worker thread.
 297  */
 298 void tl_clear(struct drbd_connection *connection)
 299 {
 300         tl_restart(connection, CONNECTION_LOST_WHILE_PENDING);
 301 }
 302
 303 /**
 304  * tl_abort_disk_io() - Abort disk I/O for all requests for a certain device in the TL
 305  * @device:     DRBD device.
 306  */
 307 void tl_abort_disk_io(struct drbd_device *device)
 308 {
 309         struct drbd_connection *connection = first_peer_device(device)->connection;
 310         struct drbd_request *req, *r;
 311
 312         spin_lock_irq(&connection->resource->req_lock);
 313         list_for_each_entry_safe(req, r, &connection->transfer_log, tl_requests) {
 314                 if (!(req->rq_state & RQ_LOCAL_PENDING))
 315                         continue;
 316                 if (req->device != device)
 317                         continue;
 318                 _req_mod(req, ABORT_DISK_IO);
 319         }
 320         spin_unlock_irq(&connection->resource->req_lock);
 321 }
 322
 323 static int drbd_thread_setup(void *arg)
 324 {
 325         struct drbd_thread *thi = (struct drbd_thread *) arg;
 326         struct drbd_resource *resource = thi->resource;
 327         unsigned long flags;
 328         int retval;
 329
 330         snprintf(current->comm, sizeof(current->comm), "drbd_%c_%s",
 331                  thi->name[0],
 332                  resource->name);
 333
 334 restart:
 335         retval = thi->function(thi);
 336
 337         spin_lock_irqsave(&thi->t_lock, flags);
 338
 339         /* if the receiver has been "EXITING", the last thing it did
 340          * was set the conn state to "StandAlone",
 341          * if now a re-connect request comes in, conn state goes C_UNCONNECTED,
 342          * and receiver thread will be "started".
 343          * drbd_thread_start needs to set "RESTARTING" in that case.
 344          * t_state check and assignment needs to be within the same spinlock,
 345          * so either thread_start sees EXITING, and can remap to RESTARTING,
 346          * or thread_start see NONE, and can proceed as normal.
 347          */
 348
 349         if (thi->t_state == RESTARTING) {
 350                 drbd_info(resource, "Restarting %s thread\n", thi->name);
 351                 thi->t_state = RUNNING;
 352                 spin_unlock_irqrestore(&thi->t_lock, flags);
 353                 goto restart;
 354         }
 355
 356         thi->task = NULL;
 357         thi->t_state = NONE;
 358         smp_mb();
 359         complete_all(&thi->stop);
 360         spin_unlock_irqrestore(&thi->t_lock, flags);
 361
 362         drbd_info(resource, "Terminating %s\n", current->comm);
 363
 364         /* Release mod reference taken when thread was started */
 365
 366         if (thi->connection)
 367                 kref_put(&thi->connection->kref, drbd_destroy_connection);
 368         kref_put(&resource->kref, drbd_destroy_resource);
 369         module_put(THIS_MODULE);
 370         return retval;
 371 }
 372
 373 static void drbd_thread_init(struct drbd_resource *resource, struct drbd_thread *thi,
 374                              int (*func) (struct drbd_thread *), const char *name)
 375 {
 376         spin_lock_init(&thi->t_lock);
 377         thi->task    = NULL;
 378         thi->t_state = NONE;
 379         thi->function = func;
 380         thi->resource = resource;
 381         thi->connection = NULL;
 382         thi->name = name;
 383 }
 384
 385 int drbd_thread_start(struct drbd_thread *thi)
 386 {
 387         struct drbd_resource *resource = thi->resource;
 388         struct task_struct *nt;
 389         unsigned long flags;
 390
 391         /* is used from state engine doing drbd_thread_stop_nowait,
 392          * while holding the req lock irqsave */
 393         spin_lock_irqsave(&thi->t_lock, flags);
 394
 395         switch (thi->t_state) {
 396         case NONE:
 397                 drbd_info(resource, "Starting %s thread (from %s [%d])\n",
 398                          thi->name, current->comm, current->pid);
 399
 400                 /* Get ref on module for thread - this is released when thread exits */
 401                 if (!try_module_get(THIS_MODULE)) {
 402                         drbd_err(resource, "Failed to get module reference in drbd_thread_start\n");
 403                         spin_unlock_irqrestore(&thi->t_lock, flags);
 404                         return false;
 405                 }
 406
 407                 kref_get(&resource->kref);
 408                 if (thi->connection)
 409                         kref_get(&thi->connection->kref);
 410
 411                 init_completion(&thi->stop);
 412                 thi->reset_cpu_mask = 1;
 413                 thi->t_state = RUNNING;
 414                 spin_unlock_irqrestore(&thi->t_lock, flags);
 415                 flush_signals(current); /* otherw. may get -ERESTARTNOINTR */
 416
 417                 nt = kthread_create(drbd_thread_setup, (void *) thi,
 418                                     "drbd_%c_%s", thi->name[0], thi->resource->name);
 419
 420                 if (IS_ERR(nt)) {
 421                         drbd_err(resource, "Couldn't start thread\n");
 422
 423                         if (thi->connection)
 424                                 kref_put(&thi->connection->kref, drbd_destroy_connection);
 425                         kref_put(&resource->kref, drbd_destroy_resource);
 426                         module_put(THIS_MODULE);
 427                         return false;
 428                 }
 429                 spin_lock_irqsave(&thi->t_lock, flags);
 430                 thi->task = nt;
 431                 thi->t_state = RUNNING;
 432                 spin_unlock_irqrestore(&thi->t_lock, flags);
 433                 wake_up_process(nt);
 434                 break;
 435         case EXITING:
 436                 thi->t_state = RESTARTING;
 437                 drbd_info(resource, "Restarting %s thread (from %s [%d])\n",
 438                                 thi->name, current->comm, current->pid);
 439                 /* fall through */
 440         case RUNNING:
 441         case RESTARTING:
 442         default:
 443                 spin_unlock_irqrestore(&thi->t_lock, flags);
 444                 break;
 445         }
 446
 447         return true;
 448 }
 449
 450
 451 void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait)
 452 {
 453         unsigned long flags;
 454
 455         enum drbd_thread_state ns = restart ? RESTARTING : EXITING;
 456
 457         /* may be called from state engine, holding the req lock irqsave */
 458         spin_lock_irqsave(&thi->t_lock, flags);
 459
 460         if (thi->t_state == NONE) {
 461                 spin_unlock_irqrestore(&thi->t_lock, flags);
 462                 if (restart)
 463                         drbd_thread_start(thi);
 464                 return;
 465         }
 466
 467         if (thi->t_state != ns) {
 468                 if (thi->task == NULL) {
 469                         spin_unlock_irqrestore(&thi->t_lock, flags);
 470                         return;
 471                 }
 472
 473                 thi->t_state = ns;
 474                 smp_mb();
 475                 init_completion(&thi->stop);
 476                 if (thi->task != current)
 477                         force_sig(DRBD_SIGKILL, thi->task);
 478         }
 479
 480         spin_unlock_irqrestore(&thi->t_lock, flags);
 481
 482         if (wait)
 483                 wait_for_completion(&thi->stop);
 484 }
 485
 486 int conn_lowest_minor(struct drbd_connection *connection)
 487 {
 488         struct drbd_peer_device *peer_device;
 489         int vnr = 0, minor = -1;
 490
 491         rcu_read_lock();
 492         peer_device = idr_get_next(&connection->peer_devices, &vnr);
 493         if (peer_device)
 494                 minor = device_to_minor(peer_device->device);
 495         rcu_read_unlock();
 496
 497         return minor;
 498 }
 499
 500 #ifdef CONFIG_SMP
 501 /**
 502  * drbd_calc_cpu_mask() - Generate CPU masks, spread over all CPUs
 503  *
 504  * Forces all threads of a resource onto the same CPU. This is beneficial for
 505  * DRBD's performance. May be overwritten by user's configuration.
 506  */
 507 static void drbd_calc_cpu_mask(cpumask_var_t *cpu_mask)
 508 {
 509         unsigned int *resources_per_cpu, min_index = ~0;
 510
 511         resources_per_cpu = kzalloc(nr_cpu_ids * sizeof(*resources_per_cpu), GFP_KERNEL);
 512         if (resources_per_cpu) {
 513                 struct drbd_resource *resource;
 514                 unsigned int cpu, min = ~0;
 515
 516                 rcu_read_lock();
 517                 for_each_resource_rcu(resource, &drbd_resources) {
 518                         for_each_cpu(cpu, resource->cpu_mask)
 519                                 resources_per_cpu[cpu]++;
 520                 }
 521                 rcu_read_unlock();
 522                 for_each_online_cpu(cpu) {
 523                         if (resources_per_cpu[cpu] < min) {
 524                                 min = resources_per_cpu[cpu];
 525                                 min_index = cpu;
 526                         }
 527                 }
 528                 kfree(resources_per_cpu);
 529         }
 530         if (min_index == ~0) {
 531                 cpumask_setall(*cpu_mask);
 532                 return;
 533         }
 534         cpumask_set_cpu(min_index, *cpu_mask);
 535 }
 536
 537 /**
 538  * drbd_thread_current_set_cpu() - modifies the cpu mask of the _current_ thread
 539  * @device:     DRBD device.
 540  * @thi:        drbd_thread object
 541  *
 542  * call in the "main loop" of _all_ threads, no need for any mutex, current won't die
 543  * prematurely.
 544  */
 545 void drbd_thread_current_set_cpu(struct drbd_thread *thi)
 546 {
 547         struct drbd_resource *resource = thi->resource;
 548         struct task_struct *p = current;
 549
 550         if (!thi->reset_cpu_mask)
 551                 return;
 552         thi->reset_cpu_mask = 0;
 553         set_cpus_allowed_ptr(p, resource->cpu_mask);
 554 }
 555 #else
 556 #define drbd_calc_cpu_mask(A) ({})
 557 #endif
 558
 559 /**
 560  * drbd_header_size  -  size of a packet header
 561  *
 562  * The header size is a multiple of 8, so any payload following the header is
 563  * word aligned on 64-bit architectures.  (The bitmap send and receive code
 564  * relies on this.)
 565  */
 566 unsigned int drbd_header_size(struct drbd_connection *connection)
 567 {
 568         if (connection->agreed_pro_version >= 100) {
 569                 BUILD_BUG_ON(!IS_ALIGNED(sizeof(struct p_header100), 8));
 570                 return sizeof(struct p_header100);
 571         } else {
 572                 BUILD_BUG_ON(sizeof(struct p_header80) !=
 573                              sizeof(struct p_header95));
 574                 BUILD_BUG_ON(!IS_ALIGNED(sizeof(struct p_header80), 8));
 575                 return sizeof(struct p_header80);
 576         }
 577 }
 578
 579 static unsigned int prepare_header80(struct p_header80 *h, enum drbd_packet cmd, int size)
 580 {
 581         h->magic   = cpu_to_be32(DRBD_MAGIC);
 582         h->command = cpu_to_be16(cmd);
 583         h->length  = cpu_to_be16(size);
 584         return sizeof(struct p_header80);
 585 }
 586
 587 static unsigned int prepare_header95(struct p_header95 *h, enum drbd_packet cmd, int size)
 588 {
 589         h->magic   = cpu_to_be16(DRBD_MAGIC_BIG);
 590         h->command = cpu_to_be16(cmd);
 591         h->length = cpu_to_be32(size);
 592         return sizeof(struct p_header95);
 593 }
 594
 595 static unsigned int prepare_header100(struct p_header100 *h, enum drbd_packet cmd,
 596                                       int size, int vnr)
 597 {
 598         h->magic = cpu_to_be32(DRBD_MAGIC_100);
 599         h->volume = cpu_to_be16(vnr);
 600         h->command = cpu_to_be16(cmd);
 601         h->length = cpu_to_be32(size);
 602         h->pad = 0;
 603         return sizeof(struct p_header100);
 604 }
 605
 606 static unsigned int prepare_header(struct drbd_connection *connection, int vnr,
 607                                    void *buffer, enum drbd_packet cmd, int size)
 608 {
 609         if (connection->agreed_pro_version >= 100)
 610                 return prepare_header100(buffer, cmd, size, vnr);
 611         else if (connection->agreed_pro_version >= 95 &&
 612                  size > DRBD_MAX_SIZE_H80_PACKET)
 613                 return prepare_header95(buffer, cmd, size);
 614         else
 615                 return prepare_header80(buffer, cmd, size);
 616 }
 617
 618 static void *__conn_prepare_command(struct drbd_connection *connection,
 619                                     struct drbd_socket *sock)
 620 {
 621         if (!sock->socket)
 622                 return NULL;
 623         return sock->sbuf + drbd_header_size(connection);
 624 }
 625
 626 void *conn_prepare_command(struct drbd_connection *connection, struct drbd_socket *sock)
 627 {
 628         void *p;
 629
 630         mutex_lock(&sock->mutex);
 631         p = __conn_prepare_command(connection, sock);
 632         if (!p)
 633                 mutex_unlock(&sock->mutex);
 634
 635         return p;
 636 }
 637
 638 void *drbd_prepare_command(struct drbd_peer_device *peer_device, struct drbd_socket *sock)
 639 {
 640         return conn_prepare_command(peer_device->connection, sock);
 641 }
 642
 643 static int __send_command(struct drbd_connection *connection, int vnr,
 644                           struct drbd_socket *sock, enum drbd_packet cmd,
 645                           unsigned int header_size, void *data,
 646                           unsigned int size)
 647 {
 648         int msg_flags;
 649         int err;
 650
 651         /*
 652          * Called with @data == NULL and the size of the data blocks in @size
 653          * for commands that send data blocks.  For those commands, omit the
 654          * MSG_MORE flag: this will increase the likelihood that data blocks
 655          * which are page aligned on the sender will end up page aligned on the
 656          * receiver.
 657          */
 658         msg_flags = data ? MSG_MORE : 0;
 659
 660         header_size += prepare_header(connection, vnr, sock->sbuf, cmd,
 661                                       header_size + size);
 662         err = drbd_send_all(connection, sock->socket, sock->sbuf, header_size,
 663                             msg_flags);
 664         if (data && !err)
 665                 err = drbd_send_all(connection, sock->socket, data, size, 0);
 666         /* DRBD protocol "pings" are latency critical.
 667          * This is supposed to trigger tcp_push_pending_frames() */
 668         if (!err && (cmd == P_PING || cmd == P_PING_ACK))
 669                 drbd_tcp_nodelay(sock->socket);
 670
 671         return err;
 672 }
 673
 674 static int __conn_send_command(struct drbd_connection *connection, struct drbd_socket *sock,
 675                                enum drbd_packet cmd, unsigned int header_size,
 676                                void *data, unsigned int size)
 677 {
 678         return __send_command(connection, 0, sock, cmd, header_size, data, size);
 679 }
 680
 681 int conn_send_command(struct drbd_connection *connection, struct drbd_socket *sock,
 682                       enum drbd_packet cmd, unsigned int header_size,
 683                       void *data, unsigned int size)
 684 {
 685         int err;
 686
 687         err = __conn_send_command(connection, sock, cmd, header_size, data, size);
 688         mutex_unlock(&sock->mutex);
 689         return err;
 690 }
 691
 692 int drbd_send_command(struct drbd_peer_device *peer_device, struct drbd_socket *sock,
 693                       enum drbd_packet cmd, unsigned int header_size,
 694                       void *data, unsigned int size)
 695 {
 696         int err;
 697
 698         err = __send_command(peer_device->connection, peer_device->device->vnr,
 699                              sock, cmd, header_size, data, size);
 700         mutex_unlock(&sock->mutex);
 701         return err;
 702 }
 703
 704 int drbd_send_ping(struct drbd_connection *connection)
 705 {
 706         struct drbd_socket *sock;
 707
 708         sock = &connection->meta;
 709         if (!conn_prepare_command(connection, sock))
 710                 return -EIO;
 711         return conn_send_command(connection, sock, P_PING, 0, NULL, 0);
 712 }
 713
 714 int drbd_send_ping_ack(struct drbd_connection *connection)
 715 {
 716         struct drbd_socket *sock;
 717
 718         sock = &connection->meta;
 719         if (!conn_prepare_command(connection, sock))
 720                 return -EIO;
 721         return conn_send_command(connection, sock, P_PING_ACK, 0, NULL, 0);
 722 }
 723
 724 int drbd_send_sync_param(struct drbd_peer_device *peer_device)
 725 {
 726         struct drbd_socket *sock;
 727         struct p_rs_param_95 *p;
 728         int size;
 729         const int apv = peer_device->connection->agreed_pro_version;
 730         enum drbd_packet cmd;
 731         struct net_conf *nc;
 732         struct disk_conf *dc;
 733
 734         sock = &peer_device->connection->data;
 735         p = drbd_prepare_command(peer_device, sock);
 736         if (!p)
 737                 return -EIO;
 738
 739         rcu_read_lock();
 740         nc = rcu_dereference(peer_device->connection->net_conf);
 741
 742         size = apv <= 87 ? sizeof(struct p_rs_param)
 743                 : apv == 88 ? sizeof(struct p_rs_param)
 744                         + strlen(nc->verify_alg) + 1
 745                 : apv <= 94 ? sizeof(struct p_rs_param_89)
 746                 : /* apv >= 95 */ sizeof(struct p_rs_param_95);
 747
 748         cmd = apv >= 89 ? P_SYNC_PARAM89 : P_SYNC_PARAM;
 749
 750         /* initialize verify_alg and csums_alg */
 751         memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);
 752
 753         if (get_ldev(peer_device->device)) {
 754                 dc = rcu_dereference(peer_device->device->ldev->disk_conf);
 755                 p->resync_rate = cpu_to_be32(dc->resync_rate);
 756                 p->c_plan_ahead = cpu_to_be32(dc->c_plan_ahead);
 757                 p->c_delay_target = cpu_to_be32(dc->c_delay_target);
 758                 p->c_fill_target = cpu_to_be32(dc->c_fill_target);
 759                 p->c_max_rate = cpu_to_be32(dc->c_max_rate);
 760                 put_ldev(peer_device->device);
 761         } else {
 762                 p->resync_rate = cpu_to_be32(DRBD_RESYNC_RATE_DEF);
 763                 p->c_plan_ahead = cpu_to_be32(DRBD_C_PLAN_AHEAD_DEF);
 764                 p->c_delay_target = cpu_to_be32(DRBD_C_DELAY_TARGET_DEF);
 765                 p->c_fill_target = cpu_to_be32(DRBD_C_FILL_TARGET_DEF);
 766                 p->c_max_rate = cpu_to_be32(DRBD_C_MAX_RATE_DEF);
 767         }
 768
 769         if (apv >= 88)
 770                 strcpy(p->verify_alg, nc->verify_alg);
 771         if (apv >= 89)
 772                 strcpy(p->csums_alg, nc->csums_alg);
 773         rcu_read_unlock();
 774
 775         return drbd_send_command(peer_device, sock, cmd, size, NULL, 0);
 776 }
 777
 778 int __drbd_send_protocol(struct drbd_connection *connection, enum drbd_packet cmd)
 779 {
 780         struct drbd_socket *sock;
 781         struct p_protocol *p;
 782         struct net_conf *nc;
 783         int size, cf;
 784
 785         sock = &connection->data;
 786         p = __conn_prepare_command(connection, sock);
 787         if (!p)
 788                 return -EIO;
 789
 790         rcu_read_lock();
 791         nc = rcu_dereference(connection->net_conf);
 792
 793         if (nc->tentative && connection->agreed_pro_version < 92) {
 794                 rcu_read_unlock();
 795                 mutex_unlock(&sock->mutex);
 796                 drbd_err(connection, "--dry-run is not supported by peer");
 797                 return -EOPNOTSUPP;
 798         }
 799
 800         size = sizeof(*p);
 801         if (connection->agreed_pro_version >= 87)
 802                 size += strlen(nc->integrity_alg) + 1;
 803
 804         p->protocol      = cpu_to_be32(nc->wire_protocol);
 805         p->after_sb_0p   = cpu_to_be32(nc->after_sb_0p);
 806         p->after_sb_1p   = cpu_to_be32(nc->after_sb_1p);
 807         p->after_sb_2p   = cpu_to_be32(nc->after_sb_2p);
 808         p->two_primaries = cpu_to_be32(nc->two_primaries);
 809         cf = 0;
 810         if (nc->discard_my_data)
 811                 cf |= CF_DISCARD_MY_DATA;
 812         if (nc->tentative)
 813                 cf |= CF_DRY_RUN;
 814         p->conn_flags    = cpu_to_be32(cf);
 815
 816         if (connection->agreed_pro_version >= 87)
 817                 strcpy(p->integrity_alg, nc->integrity_alg);
 818         rcu_read_unlock();
 819
 820         return __conn_send_command(connection, sock, cmd, size, NULL, 0);
 821 }
 822
 823 int drbd_send_protocol(struct drbd_connection *connection)
 824 {
 825         int err;
 826
 827         mutex_lock(&connection->data.mutex);
 828         err = __drbd_send_protocol(connection, P_PROTOCOL);
 829         mutex_unlock(&connection->data.mutex);
 830
 831         return err;
 832 }
 833
 834 static int _drbd_send_uuids(struct drbd_peer_device *peer_device, u64 uuid_flags)
 835 {
 836         struct drbd_device *device = peer_device->device;
 837         struct drbd_socket *sock;
 838         struct p_uuids *p;
 839         int i;
 840
 841         if (!get_ldev_if_state(device, D_NEGOTIATING))
 842                 return 0;
 843
 844         sock = &peer_device->connection->data;
 845         p = drbd_prepare_command(peer_device, sock);
 846         if (!p) {
 847                 put_ldev(device);
 848                 return -EIO;
 849         }
 850         spin_lock_irq(&device->ldev->md.uuid_lock);
 851         for (i = UI_CURRENT; i < UI_SIZE; i++)
 852                 p->uuid[i] = cpu_to_be64(device->ldev->md.uuid[i]);
 853         spin_unlock_irq(&device->ldev->md.uuid_lock);
 854
 855         device->comm_bm_set = drbd_bm_total_weight(device);
 856         p->uuid[UI_SIZE] = cpu_to_be64(device->comm_bm_set);
 857         rcu_read_lock();
 858         uuid_flags |= rcu_dereference(peer_device->connection->net_conf)->discard_my_data ? 1 : 0;
 859         rcu_read_unlock();
 860         uuid_flags |= test_bit(CRASHED_PRIMARY, &device->flags) ? 2 : 0;
 861         uuid_flags |= device->new_state_tmp.disk == D_INCONSISTENT ? 4 : 0;
 862         p->uuid[UI_FLAGS] = cpu_to_be64(uuid_flags);
 863
 864         put_ldev(device);
 865         return drbd_send_command(peer_device, sock, P_UUIDS, sizeof(*p), NULL, 0);
 866 }
 867
 868 int drbd_send_uuids(struct drbd_peer_device *peer_device)
 869 {
 870         return _drbd_send_uuids(peer_device, 0);
 871 }
 872
 873 int drbd_send_uuids_skip_initial_sync(struct drbd_peer_device *peer_device)
 874 {
 875         return _drbd_send_uuids(peer_device, 8);
 876 }
 877
 878 void drbd_print_uuids(struct drbd_device *device, const char *text)
 879 {
 880         if (get_ldev_if_state(device, D_NEGOTIATING)) {
 881                 u64 *uuid = device->ldev->md.uuid;
 882                 drbd_info(device, "%s %016llX:%016llX:%016llX:%016llX\n",
 883                      text,
 884                      (unsigned long long)uuid[UI_CURRENT],
 885                      (unsigned long long)uuid[UI_BITMAP],
 886                      (unsigned long long)uuid[UI_HISTORY_START],
 887                      (unsigned long long)uuid[UI_HISTORY_END]);
 888                 put_ldev(device);
 889         } else {
 890                 drbd_info(device, "%s effective data uuid: %016llX\n",
 891                                 text,
 892                                 (unsigned long long)device->ed_uuid);
 893         }
 894 }
 895
 896 void drbd_gen_and_send_sync_uuid(struct drbd_peer_device *peer_device)
 897 {
 898         struct drbd_device *device = peer_device->device;
 899         struct drbd_socket *sock;
 900         struct p_rs_uuid *p;
 901         u64 uuid;
 902
 903         D_ASSERT(device, device->state.disk == D_UP_TO_DATE);
 904
 905         uuid = device->ldev->md.uuid[UI_BITMAP];
 906         if (uuid && uuid != UUID_JUST_CREATED)
 907                 uuid = uuid + UUID_NEW_BM_OFFSET;
 908         else
 909                 get_random_bytes(&uuid, sizeof(u64));
 910         drbd_uuid_set(device, UI_BITMAP, uuid);
 911         drbd_print_uuids(device, "updated sync UUID");
 912         drbd_md_sync(device);
 913
 914         sock = &peer_device->connection->data;
 915         p = drbd_prepare_command(peer_device, sock);
 916         if (p) {
 917                 p->uuid = cpu_to_be64(uuid);
 918                 drbd_send_command(peer_device, sock, P_SYNC_UUID, sizeof(*p), NULL, 0);
 919         }
 920 }
 921
 922 int drbd_send_sizes(struct drbd_peer_device *peer_device, int trigger_reply, enum dds_flags flags)
 923 {
 924         struct drbd_device *device = peer_device->device;
 925         struct drbd_socket *sock;
 926         struct p_sizes *p;
 927         sector_t d_size, u_size;
 928         int q_order_type;
 929         unsigned int max_bio_size;
 930
 931         if (get_ldev_if_state(device, D_NEGOTIATING)) {
 932                 D_ASSERT(device, device->ldev->backing_bdev);
 933                 d_size = drbd_get_max_capacity(device->ldev);
 934                 rcu_read_lock();
 935                 u_size = rcu_dereference(device->ldev->disk_conf)->disk_size;
 936                 rcu_read_unlock();
 937                 q_order_type = drbd_queue_order_type(device);
 938                 max_bio_size = queue_max_hw_sectors(device->ldev->backing_bdev->bd_disk->queue) << 9;
 939                 max_bio_size = min(max_bio_size, DRBD_MAX_BIO_SIZE);
 940                 put_ldev(device);
 941         } else {
 942                 d_size = 0;
 943                 u_size = 0;
 944                 q_order_type = QUEUE_ORDERED_NONE;
 945                 max_bio_size = DRBD_MAX_BIO_SIZE; /* ... multiple BIOs per peer_request */
 946         }
 947
 948         sock = &peer_device->connection->data;
 949         p = drbd_prepare_command(peer_device, sock);
 950         if (!p)
 951                 return -EIO;
 952
 953         if (peer_device->connection->agreed_pro_version <= 94)
 954                 max_bio_size = min(max_bio_size, DRBD_MAX_SIZE_H80_PACKET);
 955         else if (peer_device->connection->agreed_pro_version < 100)
 956                 max_bio_size = min(max_bio_size, DRBD_MAX_BIO_SIZE_P95);
 957
 958         p->d_size = cpu_to_be64(d_size);
 959         p->u_size = cpu_to_be64(u_size);
 960         p->c_size = cpu_to_be64(trigger_reply ? 0 : drbd_get_capacity(device->this_bdev));
 961         p->max_bio_size = cpu_to_be32(max_bio_size);
 962         p->queue_order_type = cpu_to_be16(q_order_type);
 963         p->dds_flags = cpu_to_be16(flags);
 964         return drbd_send_command(peer_device, sock, P_SIZES, sizeof(*p), NULL, 0);
 965 }
 966
 967 /**
 968  * drbd_send_current_state() - Sends the drbd state to the peer
 969  * @peer_device:        DRBD peer device.
 970  */
 971 int drbd_send_current_state(struct drbd_peer_device *peer_device)
 972 {
 973         struct drbd_socket *sock;
 974         struct p_state *p;
 975
 976         sock = &peer_device->connection->data;
 977         p = drbd_prepare_command(peer_device, sock);
 978         if (!p)
 979                 return -EIO;
 980         p->state = cpu_to_be32(peer_device->device->state.i); /* Within the send mutex */
 981         return drbd_send_command(peer_device, sock, P_STATE, sizeof(*p), NULL, 0);
 982 }
 983
 984 /**
 985  * drbd_send_state() - After a state change, sends the new state to the peer
 986  * @peer_device:      DRBD peer device.
 987  * @state:     the state to send, not necessarily the current state.
 988  *
 989  * Each state change queues an "after_state_ch" work, which will eventually
 990  * send the resulting new state to the peer. If more state changes happen
 991  * between queuing and processing of the after_state_ch work, we still
 992  * want to send each intermediary state in the order it occurred.
 993  */
 994 int drbd_send_state(struct drbd_peer_device *peer_device, union drbd_state state)
 995 {
 996         struct drbd_socket *sock;
 997         struct p_state *p;
 998
 999         sock = &peer_device->connection->data;
1000         p = drbd_prepare_command(peer_device, sock);
1001         if (!p)
1002                 return -EIO;
1003         p->state = cpu_to_be32(state.i); /* Within the send mutex */
1004         return drbd_send_command(peer_device, sock, P_STATE, sizeof(*p), NULL, 0);
1005 }
1006
1007 int drbd_send_state_req(struct drbd_peer_device *peer_device, union drbd_state mask, union drbd_state val)
1008 {
1009         struct drbd_socket *sock;
1010         struct p_req_state *p;
1011
1012         sock = &peer_device->connection->data;
1013         p = drbd_prepare_command(peer_device, sock);
1014         if (!p)
1015                 return -EIO;
1016         p->mask = cpu_to_be32(mask.i);
1017         p->val = cpu_to_be32(val.i);
1018         return drbd_send_command(peer_device, sock, P_STATE_CHG_REQ, sizeof(*p), NULL, 0);
1019 }
1020
1021 int conn_send_state_req(struct drbd_connection *connection, union drbd_state mask, union drbd_state val)
1022 {
1023         enum drbd_packet cmd;
1024         struct drbd_socket *sock;
1025         struct p_req_state *p;
1026
1027         cmd = connection->agreed_pro_version < 100 ? P_STATE_CHG_REQ : P_CONN_ST_CHG_REQ;
1028         sock = &connection->data;
1029         p = conn_prepare_command(connection, sock);
1030         if (!p)
1031                 return -EIO;
1032         p->mask = cpu_to_be32(mask.i);
1033         p->val = cpu_to_be32(val.i);
1034         return conn_send_command(connection, sock, cmd, sizeof(*p), NULL, 0);
1035 }
1036
1037 void drbd_send_sr_reply(struct drbd_peer_device *peer_device, enum drbd_state_rv retcode)
1038 {
1039         struct drbd_socket *sock;
1040         struct p_req_state_reply *p;
1041
1042         sock = &peer_device->connection->meta;
1043         p = drbd_prepare_command(peer_device, sock);
1044         if (p) {
1045                 p->retcode = cpu_to_be32(retcode);
1046                 drbd_send_command(peer_device, sock, P_STATE_CHG_REPLY, sizeof(*p), NULL, 0);
1047         }
1048 }
1049
1050 void conn_send_sr_reply(struct drbd_connection *connection, enum drbd_state_rv retcode)
1051 {
1052         struct drbd_socket *sock;
1053         struct p_req_state_reply *p;
1054         enum drbd_packet cmd = connection->agreed_pro_version < 100 ? P_STATE_CHG_REPLY : P_CONN_ST_CHG_REPLY;
1055
1056         sock = &connection->meta;
1057         p = conn_prepare_command(connection, sock);
1058         if (p) {
1059                 p->retcode = cpu_to_be32(retcode);
1060                 conn_send_command(connection, sock, cmd, sizeof(*p), NULL, 0);
1061         }
1062 }
1063
1064 static void dcbp_set_code(struct p_compressed_bm *p, enum drbd_bitmap_code code)
1065 {
1066         BUG_ON(code & ~0xf);
1067         p->encoding = (p->encoding & ~0xf) | code;
1068 }
1069
1070 static void dcbp_set_start(struct p_compressed_bm *p, int set)
1071 {
1072         p->encoding = (p->encoding & ~0x80) | (set ? 0x80 : 0);
1073 }
1074
1075 static void dcbp_set_pad_bits(struct p_compressed_bm *p, int n)
1076 {
1077         BUG_ON(n & ~0x7);
1078         p->encoding = (p->encoding & (~0x7 << 4)) | (n << 4);
1079 }
1080
1081 static int fill_bitmap_rle_bits(struct drbd_device *device,
1082                          struct p_compressed_bm *p,
1083                          unsigned int size,
1084                          struct bm_xfer_ctx *c)
1085 {
1086         struct bitstream bs;
1087         unsigned long plain_bits;
1088         unsigned long tmp;
1089         unsigned long rl;
1090         unsigned len;
1091         unsigned toggle;
1092         int bits, use_rle;
1093
1094         /* may we use this feature? */
1095         rcu_read_lock();
1096         use_rle = rcu_dereference(first_peer_device(device)->connection->net_conf)->use_rle;
1097         rcu_read_unlock();
1098         if (!use_rle || first_peer_device(device)->connection->agreed_pro_version < 90)
1099                 return 0;
1100
1101         if (c->bit_offset >= c->bm_bits)
1102                 return 0; /* nothing to do. */
1103
1104         /* use at most thus many bytes */
1105         bitstream_init(&bs, p->code, size, 0);
1106         memset(p->code, 0, size);
1107         /* plain bits covered in this code string */
1108         plain_bits = 0;
1109
1110         /* p->encoding & 0x80 stores whether the first run length is set.
1111          * bit offset is implicit.
1112          * start with toggle == 2 to be able to tell the first iteration */
1113         toggle = 2;
1114
1115         /* see how much plain bits we can stuff into one packet
1116          * using RLE and VLI. */
1117         do {
1118                 tmp = (toggle == 0) ? _drbd_bm_find_next_zero(device, c->bit_offset)
1119                                     : _drbd_bm_find_next(device, c->bit_offset);
1120                 if (tmp == -1UL)
1121                         tmp = c->bm_bits;
1122                 rl = tmp - c->bit_offset;
1123
1124                 if (toggle == 2) { /* first iteration */
1125                         if (rl == 0) {
1126                                 /* the first checked bit was set,
1127                                  * store start value, */
1128                                 dcbp_set_start(p, 1);
1129                                 /* but skip encoding of zero run length */
1130                                 toggle = !toggle;
1131                                 continue;
1132                         }
1133                         dcbp_set_start(p, 0);
1134                 }
1135
1136                 /* paranoia: catch zero runlength.
1137                  * can only happen if bitmap is modified while we scan it. */
1138                 if (rl == 0) {
1139                         drbd_err(device, "unexpected zero runlength while encoding bitmap "
1140                             "t:%u bo:%lu\n", toggle, c->bit_offset);
1141                         return -1;
1142                 }
1143
1144                 bits = vli_encode_bits(&bs, rl);
1145                 if (bits == -ENOBUFS) /* buffer full */
1146                         break;
1147                 if (bits <= 0) {
1148                         drbd_err(device, "error while encoding bitmap: %d\n", bits);
1149                         return 0;
1150                 }
1151
1152                 toggle = !toggle;
1153                 plain_bits += rl;
1154                 c->bit_offset = tmp;
1155         } while (c->bit_offset < c->bm_bits);
1156
1157         len = bs.cur.b - p->code + !!bs.cur.bit;
1158
1159         if (plain_bits < (len << 3)) {
1160                 /* incompressible with this method.
1161                  * we need to rewind both word and bit position. */
1162                 c->bit_offset -= plain_bits;
1163                 bm_xfer_ctx_bit_to_word_offset(c);
1164                 c->bit_offset = c->word_offset * BITS_PER_LONG;
1165                 return 0;
1166         }
1167
1168         /* RLE + VLI was able to compress it just fine.
1169          * update c->word_offset. */
1170         bm_xfer_ctx_bit_to_word_offset(c);
1171
1172         /* store pad_bits */
1173         dcbp_set_pad_bits(p, (8 - bs.cur.bit) & 0x7);
1174
1175         return len;
1176 }
1177
1178 /**
1179  * send_bitmap_rle_or_plain
1180  *
1181  * Return 0 when done, 1 when another iteration is needed, and a negative error
1182  * code upon failure.
1183  */
1184 static int
1185 send_bitmap_rle_or_plain(struct drbd_device *device, struct bm_xfer_ctx *c)
1186 {
1187         struct drbd_socket *sock = &first_peer_device(device)->connection->data;
1188         unsigned int header_size = drbd_header_size(first_peer_device(device)->connection);
1189         struct p_compressed_bm *p = sock->sbuf + header_size;
1190         int len, err;
1191
1192         len = fill_bitmap_rle_bits(device, p,
1193                         DRBD_SOCKET_BUFFER_SIZE - header_size - sizeof(*p), c);
1194         if (len < 0)
1195                 return -EIO;
1196
1197         if (len) {
1198                 dcbp_set_code(p, RLE_VLI_Bits);
1199                 err = __send_command(first_peer_device(device)->connection, device->vnr, sock,
1200                                      P_COMPRESSED_BITMAP, sizeof(*p) + len,
1201                                      NULL, 0);
1202                 c->packets[0]++;
1203                 c->bytes[0] += header_size + sizeof(*p) + len;
1204
1205                 if (c->bit_offset >= c->bm_bits)
1206                         len = 0; /* DONE */
1207         } else {
1208                 /* was not compressible.
1209                  * send a buffer full of plain text bits instead. */
1210                 unsigned int data_size;
1211                 unsigned long num_words;
1212                 unsigned long *p = sock->sbuf + header_size;
1213
1214                 data_size = DRBD_SOCKET_BUFFER_SIZE - header_size;
1215                 num_words = min_t(size_t, data_size / sizeof(*p),
1216                                   c->bm_words - c->word_offset);
1217                 len = num_words * sizeof(*p);
1218                 if (len)
1219                         drbd_bm_get_lel(device, c->word_offset, num_words, p);
1220                 err = __send_command(first_peer_device(device)->connection, device->vnr, sock, P_BITMAP, len, NULL, 0);
1221                 c->word_offset += num_words;
1222                 c->bit_offset = c->word_offset * BITS_PER_LONG;
1223
1224                 c->packets[1]++;
1225                 c->bytes[1] += header_size + len;
1226
1227                 if (c->bit_offset > c->bm_bits)
1228                         c->bit_offset = c->bm_bits;
1229         }
1230         if (!err) {
1231                 if (len == 0) {
1232                         INFO_bm_xfer_stats(device, "send", c);
1233                         return 0;
1234                 } else
1235                         return 1;
1236         }
1237         return -EIO;
1238 }
1239
1240 /* See the comment at receive_bitmap() */
1241 static int _drbd_send_bitmap(struct drbd_device *device)
1242 {
1243         struct bm_xfer_ctx c;
1244         int err;
1245
1246         if (!expect(device->bitmap))
1247                 return false;
1248
1249         if (get_ldev(device)) {
1250                 if (drbd_md_test_flag(device->ldev, MDF_FULL_SYNC)) {
1251                         drbd_info(device, "Writing the whole bitmap, MDF_FullSync was set.\n");
1252                         drbd_bm_set_all(device);
1253                         if (drbd_bm_write(device)) {
1254                                 /* write_bm did fail! Leave full sync flag set in Meta P_DATA
1255                                  * but otherwise process as per normal - need to tell other
1256                                  * side that a full resync is required! */
1257                                 drbd_err(device, "Failed to write bitmap to disk!\n");
1258                         } else {
1259                                 drbd_md_clear_flag(device, MDF_FULL_SYNC);
1260                                 drbd_md_sync(device);
1261                         }
1262                 }
1263                 put_ldev(device);
1264         }
1265
1266         c = (struct bm_xfer_ctx) {
1267                 .bm_bits = drbd_bm_bits(device),
1268                 .bm_words = drbd_bm_words(device),
1269         };
1270
1271         do {
1272                 err = send_bitmap_rle_or_plain(device, &c);
1273         } while (err > 0);
1274
1275         return err == 0;
1276 }
1277
1278 int drbd_send_bitmap(struct drbd_device *device)
1279 {
1280         struct drbd_socket *sock = &first_peer_device(device)->connection->data;
1281         int err = -1;
1282
1283         mutex_lock(&sock->mutex);
1284         if (sock->socket)
1285                 err = !_drbd_send_bitmap(device);
1286         mutex_unlock(&sock->mutex);
1287         return err;
1288 }
1289
1290 void drbd_send_b_ack(struct drbd_connection *connection, u32 barrier_nr, u32 set_size)
1291 {
1292         struct drbd_socket *sock;
1293         struct p_barrier_ack *p;
1294
1295         if (connection->cstate < C_WF_REPORT_PARAMS)
1296                 return;
1297
1298         sock = &connection->meta;
1299         p = conn_prepare_command(connection, sock);
1300         if (!p)
1301                 return;
1302         p->barrier = barrier_nr;
1303         p->set_size = cpu_to_be32(set_size);
1304         conn_send_command(connection, sock, P_BARRIER_ACK, sizeof(*p), NULL, 0);
1305 }
1306
1307 /**
1308  * _drbd_send_ack() - Sends an ack packet
1309  * @device:     DRBD device.
1310  * @cmd:        Packet command code.
1311  * @sector:     sector, needs to be in big endian byte order
1312  * @blksize:    size in byte, needs to be in big endian byte order
1313  * @block_id:   Id, big endian byte order
1314  */
1315 static int _drbd_send_ack(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1316                           u64 sector, u32 blksize, u64 block_id)
1317 {
1318         struct drbd_socket *sock;
1319         struct p_block_ack *p;
1320
1321         if (peer_device->device->state.conn < C_CONNECTED)
1322                 return -EIO;
1323
1324         sock = &peer_device->connection->meta;
1325         p = drbd_prepare_command(peer_device, sock);
1326         if (!p)
1327                 return -EIO;
1328         p->sector = sector;
1329         p->block_id = block_id;
1330         p->blksize = blksize;
1331         p->seq_num = cpu_to_be32(atomic_inc_return(&peer_device->device->packet_seq));
1332         return drbd_send_command(peer_device, sock, cmd, sizeof(*p), NULL, 0);
1333 }
1334
1335 /* dp->sector and dp->block_id already/still in network byte order,
1336  * data_size is payload size according to dp->head,
1337  * and may need to be corrected for digest size. */
1338 void drbd_send_ack_dp(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1339                       struct p_data *dp, int data_size)
1340 {
1341         if (peer_device->connection->peer_integrity_tfm)
1342                 data_size -= crypto_hash_digestsize(peer_device->connection->peer_integrity_tfm);
1343         _drbd_send_ack(peer_device, cmd, dp->sector, cpu_to_be32(data_size),
1344                        dp->block_id);
1345 }
1346
1347 void drbd_send_ack_rp(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1348                       struct p_block_req *rp)
1349 {
1350         _drbd_send_ack(peer_device, cmd, rp->sector, rp->blksize, rp->block_id);
1351 }
1352
1353 /**
1354  * drbd_send_ack() - Sends an ack packet
1355  * @device:     DRBD device
1356  * @cmd:        packet command code
1357  * @peer_req:   peer request
1358  */
1359 int drbd_send_ack(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1360                   struct drbd_peer_request *peer_req)
1361 {
1362         return _drbd_send_ack(peer_device, cmd,
1363                               cpu_to_be64(peer_req->i.sector),
1364                               cpu_to_be32(peer_req->i.size),
1365                               peer_req->block_id);
1366 }
1367
1368 /* This function misuses the block_id field to signal if the blocks
1369  * are is sync or not. */
1370 int drbd_send_ack_ex(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1371                      sector_t sector, int blksize, u64 block_id)
1372 {
1373         return _drbd_send_ack(peer_device, cmd,
1374                               cpu_to_be64(sector),
1375                               cpu_to_be32(blksize),
1376                               cpu_to_be64(block_id));
1377 }
1378
1379 int drbd_send_drequest(struct drbd_peer_device *peer_device, int cmd,
1380                        sector_t sector, int size, u64 block_id)
1381 {
1382         struct drbd_socket *sock;
1383         struct p_block_req *p;
1384
1385         sock = &peer_device->connection->data;
1386         p = drbd_prepare_command(peer_device, sock);
1387         if (!p)
1388                 return -EIO;
1389         p->sector = cpu_to_be64(sector);
1390         p->block_id = block_id;
1391         p->blksize = cpu_to_be32(size);
1392         return drbd_send_command(peer_device, sock, cmd, sizeof(*p), NULL, 0);
1393 }
1394
1395 int drbd_send_drequest_csum(struct drbd_peer_device *peer_device, sector_t sector, int size,
1396                             void *digest, int digest_size, enum drbd_packet cmd)
1397 {
1398         struct drbd_socket *sock;
1399         struct p_block_req *p;
1400
1401         /* FIXME: Put the digest into the preallocated socket buffer.  */
1402
1403         sock = &peer_device->connection->data;
1404         p = drbd_prepare_command(peer_device, sock);
1405         if (!p)
1406                 return -EIO;
1407         p->sector = cpu_to_be64(sector);
1408         p->block_id = ID_SYNCER /* unused */;
1409         p->blksize = cpu_to_be32(size);
1410         return drbd_send_command(peer_device, sock, cmd, sizeof(*p), digest, digest_size);
1411 }
1412
1413 int drbd_send_ov_request(struct drbd_peer_device *peer_device, sector_t sector, int size)
1414 {
1415         struct drbd_socket *sock;
1416         struct p_block_req *p;
1417
1418         sock = &peer_device->connection->data;
1419         p = drbd_prepare_command(peer_device, sock);
1420         if (!p)
1421                 return -EIO;
1422         p->sector = cpu_to_be64(sector);
1423         p->block_id = ID_SYNCER /* unused */;
1424         p->blksize = cpu_to_be32(size);
1425         return drbd_send_command(peer_device, sock, P_OV_REQUEST, sizeof(*p), NULL, 0);
1426 }
1427
1428 /* called on sndtimeo
1429  * returns false if we should retry,
1430  * true if we think connection is dead
1431  */
1432 static int we_should_drop_the_connection(struct drbd_connection *connection, struct socket *sock)
1433 {
1434         int drop_it;
1435         /* long elapsed = (long)(jiffies - device->last_received); */
1436
1437         drop_it =   connection->meta.socket == sock
1438                 || !connection->asender.task
1439                 || get_t_state(&connection->asender) != RUNNING
1440                 || connection->cstate < C_WF_REPORT_PARAMS;
1441
1442         if (drop_it)
1443                 return true;
1444
1445         drop_it = !--connection->ko_count;
1446         if (!drop_it) {
1447                 drbd_err(connection, "[%s/%d] sock_sendmsg time expired, ko = %u\n",
1448                          current->comm, current->pid, connection->ko_count);
1449                 request_ping(connection);
1450         }
1451
1452         return drop_it; /* && (device->state == R_PRIMARY) */;
1453 }
1454
1455 static void drbd_update_congested(struct drbd_connection *connection)
1456 {
1457         struct sock *sk = connection->data.socket->sk;
1458         if (sk->sk_wmem_queued > sk->sk_sndbuf * 4 / 5)
1459                 set_bit(NET_CONGESTED, &connection->flags);
1460 }
1461
1462 /* The idea of sendpage seems to be to put some kind of reference
1463  * to the page into the skb, and to hand it over to the NIC. In
1464  * this process get_page() gets called.
1465  *
1466  * As soon as the page was really sent over the network put_page()
1467  * gets called by some part of the network layer. [ NIC driver? ]
1468  *
1469  * [ get_page() / put_page() increment/decrement the count. If count
1470  *   reaches 0 the page will be freed. ]
1471  *
1472  * This works nicely with pages from FSs.
1473  * But this means that in protocol A we might signal IO completion too early!
1474  *
1475  * In order not to corrupt data during a resync we must make sure
1476  * that we do not reuse our own buffer pages (EEs) to early, therefore
1477  * we have the net_ee list.
1478  *
1479  * XFS seems to have problems, still, it submits pages with page_count == 0!
1480  * As a workaround, we disable sendpage on pages
1481  * with page_count == 0 or PageSlab.
1482  */
1483 static int _drbd_no_send_page(struct drbd_peer_device *peer_device, struct page *page,
1484                               int offset, size_t size, unsigned msg_flags)
1485 {
1486         struct socket *socket;
1487         void *addr;
1488         int err;
1489
1490         socket = peer_device->connection->data.socket;
1491         addr = kmap(page) + offset;
1492         err = drbd_send_all(peer_device->connection, socket, addr, size, msg_flags);
1493         kunmap(page);
1494         if (!err)
1495                 peer_device->device->send_cnt += size >> 9;
1496         return err;
1497 }
1498
1499 static int _drbd_send_page(struct drbd_peer_device *peer_device, struct page *page,
1500                     int offset, size_t size, unsigned msg_flags)
1501 {
1502         struct socket *socket = peer_device->connection->data.socket;
1503         mm_segment_t oldfs = get_fs();
1504         int len = size;
1505         int err = -EIO;
1506
1507         /* e.g. XFS meta- & log-data is in slab pages, which have a
1508          * page_count of 0 and/or have PageSlab() set.
1509          * we cannot use send_page for those, as that does get_page();
1510          * put_page(); and would cause either a VM_BUG directly, or
1511          * __page_cache_release a page that would actually still be referenced
1512          * by someone, leading to some obscure delayed Oops somewhere else. */
1513         if (disable_sendpage || (page_count(page) < 1) || PageSlab(page))
1514                 return _drbd_no_send_page(peer_device, page, offset, size, msg_flags);
1515
1516         msg_flags |= MSG_NOSIGNAL;
1517         drbd_update_congested(peer_device->connection);
1518         set_fs(KERNEL_DS);
1519         do {
1520                 int sent;
1521
1522                 sent = socket->ops->sendpage(socket, page, offset, len, msg_flags);
1523                 if (sent <= 0) {
1524                         if (sent == -EAGAIN) {
1525                                 if (we_should_drop_the_connection(peer_device->connection, socket))
1526                                         break;
1527                                 continue;
1528                         }
1529                         drbd_warn(peer_device->device, "%s: size=%d len=%d sent=%d\n",
1530                              __func__, (int)size, len, sent);
1531                         if (sent < 0)
1532                                 err = sent;
1533                         break;
1534                 }
1535                 len    -= sent;
1536                 offset += sent;
1537         } while (len > 0 /* THINK && device->cstate >= C_CONNECTED*/);
1538         set_fs(oldfs);
1539         clear_bit(NET_CONGESTED, &peer_device->connection->flags);
1540
1541         if (len == 0) {
1542                 err = 0;
1543                 peer_device->device->send_cnt += size >> 9;
1544         }
1545         return err;
1546 }
1547
1548 static int _drbd_send_bio(struct drbd_peer_device *peer_device, struct bio *bio)
1549 {
1550         struct bio_vec bvec;
1551         struct bvec_iter iter;
1552
1553         /* hint all but last page with MSG_MORE */
1554         bio_for_each_segment(bvec, bio, iter) {
1555                 int err;
1556
1557                 err = _drbd_no_send_page(peer_device, bvec.bv_page,
1558                                          bvec.bv_offset, bvec.bv_len,
1559                                          bio_iter_last(bvec, iter)
1560                                          ? 0 : MSG_MORE);
1561                 if (err)
1562                         return err;
1563         }
1564         return 0;
1565 }
1566
1567 static int _drbd_send_zc_bio(struct drbd_peer_device *peer_device, struct bio *bio)
1568 {
1569         struct bio_vec bvec;
1570         struct bvec_iter iter;
1571
1572         /* hint all but last page with MSG_MORE */
1573         bio_for_each_segment(bvec, bio, iter) {
1574                 int err;
1575
1576                 err = _drbd_send_page(peer_device, bvec.bv_page,
1577                                       bvec.bv_offset, bvec.bv_len,
1578                                       bio_iter_last(bvec, iter) ? 0 : MSG_MORE);
1579                 if (err)
1580                         return err;
1581         }
1582         return 0;
1583 }
1584
1585 static int _drbd_send_zc_ee(struct drbd_peer_device *peer_device,
1586                             struct drbd_peer_request *peer_req)
1587 {
1588         struct page *page = peer_req->pages;
1589         unsigned len = peer_req->i.size;
1590         int err;
1591
1592         /* hint all but last page with MSG_MORE */
1593         page_chain_for_each(page) {
1594                 unsigned l = min_t(unsigned, len, PAGE_SIZE);
1595
1596                 err = _drbd_send_page(peer_device, page, 0, l,
1597                                       page_chain_next(page) ? MSG_MORE : 0);
1598                 if (err)
1599                         return err;
1600                 len -= l;
1601         }
1602         return 0;
1603 }
1604
1605 static u32 bio_flags_to_wire(struct drbd_connection *connection, unsigned long bi_rw)
1606 {
1607         if (connection->agreed_pro_version >= 95)
1608                 return  (bi_rw & REQ_SYNC ? DP_RW_SYNC : 0) |
1609                         (bi_rw & REQ_FUA ? DP_FUA : 0) |
1610                         (bi_rw & REQ_FLUSH ? DP_FLUSH : 0) |
1611                         (bi_rw & REQ_DISCARD ? DP_DISCARD : 0);
1612         else
1613                 return bi_rw & REQ_SYNC ? DP_RW_SYNC : 0;
1614 }
1615
1616 /* Used to send write or TRIM aka REQ_DISCARD requests
1617  * R_PRIMARY -> Peer    (P_DATA, P_TRIM)
1618  */
1619 int drbd_send_dblock(struct drbd_peer_device *peer_device, struct drbd_request *req)
1620 {
1621         struct drbd_device *device = peer_device->device;
1622         struct drbd_socket *sock;
1623         struct p_data *p;
1624         unsigned int dp_flags = 0;
1625         int digest_size;
1626         int err;
1627
1628         sock = &peer_device->connection->data;
1629         p = drbd_prepare_command(peer_device, sock);
1630         digest_size = peer_device->connection->integrity_tfm ?
1631                       crypto_hash_digestsize(peer_device->connection->integrity_tfm) : 0;
1632
1633         if (!p)
1634                 return -EIO;
1635         p->sector = cpu_to_be64(req->i.sector);
1636         p->block_id = (unsigned long)req;
1637         p->seq_num = cpu_to_be32(atomic_inc_return(&device->packet_seq));
1638         dp_flags = bio_flags_to_wire(peer_device->connection, req->master_bio->bi_rw);
1639         if (device->state.conn >= C_SYNC_SOURCE &&
1640             device->state.conn <= C_PAUSED_SYNC_T)
1641                 dp_flags |= DP_MAY_SET_IN_SYNC;
1642         if (peer_device->connection->agreed_pro_version >= 100) {
1643                 if (req->rq_state & RQ_EXP_RECEIVE_ACK)
1644                         dp_flags |= DP_SEND_RECEIVE_ACK;
1645                 /* During resync, request an explicit write ack,
1646                  * even in protocol != C */
1647                 if (req->rq_state & RQ_EXP_WRITE_ACK
1648                 || (dp_flags & DP_MAY_SET_IN_SYNC))
1649                         dp_flags |= DP_SEND_WRITE_ACK;
1650         }
1651         p->dp_flags = cpu_to_be32(dp_flags);
1652
1653         if (dp_flags & DP_DISCARD) {
1654                 struct p_trim *t = (struct p_trim*)p;
1655                 t->size = cpu_to_be32(req->i.size);
1656                 err = __send_command(peer_device->connection, device->vnr, sock, P_TRIM, sizeof(*t), NULL, 0);
1657                 goto out;
1658         }
1659
1660         /* our digest is still only over the payload.
1661          * TRIM does not carry any payload. */
1662         if (digest_size)
1663                 drbd_csum_bio(peer_device->connection->integrity_tfm, req->master_bio, p + 1);
1664         err = __send_command(peer_device->connection, device->vnr, sock, P_DATA, sizeof(*p) + digest_size, NULL, req->i.size);
1665         if (!err) {
1666                 /* For protocol A, we have to memcpy the payload into
1667                  * socket buffers, as we may complete right away
1668                  * as soon as we handed it over to tcp, at which point the data
1669                  * pages may become invalid.
1670                  *
1671                  * For data-integrity enabled, we copy it as well, so we can be
1672                  * sure that even if the bio pages may still be modified, it
1673                  * won't change the data on the wire, thus if the digest checks
1674                  * out ok after sending on this side, but does not fit on the
1675                  * receiving side, we sure have detected corruption elsewhere.
1676                  */
1677                 if (!(req->rq_state & (RQ_EXP_RECEIVE_ACK | RQ_EXP_WRITE_ACK)) || digest_size)
1678                         err = _drbd_send_bio(peer_device, req->master_bio);
1679                 else
1680                         err = _drbd_send_zc_bio(peer_device, req->master_bio);
1681
1682                 /* double check digest, sometimes buffers have been modified in flight. */
1683                 if (digest_size > 0 && digest_size <= 64) {
1684                         /* 64 byte, 512 bit, is the largest digest size
1685                          * currently supported in kernel crypto. */
1686                         unsigned char digest[64];
1687                         drbd_csum_bio(peer_device->connection->integrity_tfm, req->master_bio, digest);
1688                         if (memcmp(p + 1, digest, digest_size)) {
1689                                 drbd_warn(device,
1690                                         "Digest mismatch, buffer modified by upper layers during write: %llus +%u\n",
1691                                         (unsigned long long)req->i.sector, req->i.size);
1692                         }
1693                 } /* else if (digest_size > 64) {
1694                      ... Be noisy about digest too large ...
1695                 } */
1696         }
1697 out:
1698         mutex_unlock(&sock->mutex);  /* locked by drbd_prepare_command() */
1699
1700         return err;
1701 }
1702
1703 /* answer packet, used to send data back for read requests:
1704  *  Peer       -> (diskless) R_PRIMARY   (P_DATA_REPLY)
1705  *  C_SYNC_SOURCE -> C_SYNC_TARGET         (P_RS_DATA_REPLY)
1706  */
1707 int drbd_send_block(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1708                     struct drbd_peer_request *peer_req)
1709 {
1710         struct drbd_device *device = peer_device->device;
1711         struct drbd_socket *sock;
1712         struct p_data *p;
1713         int err;
1714         int digest_size;
1715
1716         sock = &peer_device->connection->data;
1717         p = drbd_prepare_command(peer_device, sock);
1718
1719         digest_size = peer_device->connection->integrity_tfm ?
1720                       crypto_hash_digestsize(peer_device->connection->integrity_tfm) : 0;
1721
1722         if (!p)
1723                 return -EIO;
1724         p->sector = cpu_to_be64(peer_req->i.sector);
1725         p->block_id = peer_req->block_id;
1726         p->seq_num = 0;  /* unused */
1727         p->dp_flags = 0;
1728         if (digest_size)
1729                 drbd_csum_ee(peer_device->connection->integrity_tfm, peer_req, p + 1);
1730         err = __send_command(peer_device->connection, device->vnr, sock, cmd, sizeof(*p) + digest_size, NULL, peer_req->i.size);
1731         if (!err)
1732                 err = _drbd_send_zc_ee(peer_device, peer_req);
1733         mutex_unlock(&sock->mutex);  /* locked by drbd_prepare_command() */
1734
1735         return err;
1736 }
1737
1738 int drbd_send_out_of_sync(struct drbd_peer_device *peer_device, struct drbd_request *req)
1739 {
1740         struct drbd_socket *sock;
1741         struct p_block_desc *p;
1742
1743         sock = &peer_device->connection->data;
1744         p = drbd_prepare_command(peer_device, sock);
1745         if (!p)
1746                 return -EIO;
1747         p->sector = cpu_to_be64(req->i.sector);
1748         p->blksize = cpu_to_be32(req->i.size);
1749         return drbd_send_command(peer_device, sock, P_OUT_OF_SYNC, sizeof(*p), NULL, 0);
1750 }
1751
1752 /*
1753   drbd_send distinguishes two cases:
1754
1755   Packets sent via the data socket "sock"
1756   and packets sent via the meta data socket "msock"
1757
1758                     sock                      msock
1759   -----------------+-------------------------+------------------------------
1760   timeout           conf.timeout / 2          conf.timeout / 2
1761   timeout action    send a ping via msock     Abort communication
1762                                               and close all sockets
1763 */
1764
1765 /*
1766  * you must have down()ed the appropriate [m]sock_mutex elsewhere!
1767  */
1768 int drbd_send(struct drbd_connection *connection, struct socket *sock,
1769               void *buf, size_t size, unsigned msg_flags)
1770 {
1771         struct kvec iov;
1772         struct msghdr msg;
1773         int rv, sent = 0;
1774
1775         if (!sock)
1776                 return -EBADR;
1777
1778         /* THINK  if (signal_pending) return ... ? */
1779
1780         iov.iov_base = buf;
1781         iov.iov_len  = size;
1782
1783         msg.msg_name       = NULL;
1784         msg.msg_namelen    = 0;
1785         msg.msg_control    = NULL;
1786         msg.msg_controllen = 0;
1787         msg.msg_flags      = msg_flags | MSG_NOSIGNAL;
1788
1789         if (sock == connection->data.socket) {
1790                 rcu_read_lock();
1791                 connection->ko_count = rcu_dereference(connection->net_conf)->ko_count;
1792                 rcu_read_unlock();
1793                 drbd_update_congested(connection);
1794         }
1795         do {
1796                 /* STRANGE
1797                  * tcp_sendmsg does _not_ use its size parameter at all ?
1798                  *
1799                  * -EAGAIN on timeout, -EINTR on signal.
1800                  */
1801 /* THINK
1802  * do we need to block DRBD_SIG if sock == &meta.socket ??
1803  * otherwise wake_asender() might interrupt some send_*Ack !
1804  */
1805                 rv = kernel_sendmsg(sock, &msg, &iov, 1, size);
1806                 if (rv == -EAGAIN) {
1807                         if (we_should_drop_the_connection(connection, sock))
1808                                 break;
1809                         else
1810                                 continue;
1811                 }
1812                 if (rv == -EINTR) {
1813                         flush_signals(current);
1814                         rv = 0;
1815                 }
1816                 if (rv < 0)
1817                         break;
1818                 sent += rv;
1819                 iov.iov_base += rv;
1820                 iov.iov_len  -= rv;
1821         } while (sent < size);
1822
1823         if (sock == connection->data.socket)
1824                 clear_bit(NET_CONGESTED, &connection->flags);
1825
1826         if (rv <= 0) {
1827                 if (rv != -EAGAIN) {
1828                         drbd_err(connection, "%s_sendmsg returned %d\n",
1829                                  sock == connection->meta.socket ? "msock" : "sock",
1830                                  rv);
1831                         conn_request_state(connection, NS(conn, C_BROKEN_PIPE), CS_HARD);
1832                 } else
1833                         conn_request_state(connection, NS(conn, C_TIMEOUT), CS_HARD);
1834         }
1835
1836         return sent;
1837 }
1838
1839 /**
1840  * drbd_send_all  -  Send an entire buffer
1841  *
1842  * Returns 0 upon success and a negative error value otherwise.
1843  */
1844 int drbd_send_all(struct drbd_connection *connection, struct socket *sock, void *buffer,
1845                   size_t size, unsigned msg_flags)
1846 {
1847         int err;
1848
1849         err = drbd_send(connection, sock, buffer, size, msg_flags);
1850         if (err < 0)
1851                 return err;
1852         if (err != size)
1853                 return -EIO;
1854         return 0;
1855 }
1856
1857 static int drbd_open(struct block_device *bdev, fmode_t mode)
1858 {
1859         struct drbd_device *device = bdev->bd_disk->private_data;
1860         unsigned long flags;
1861         int rv = 0;
1862
1863         mutex_lock(&drbd_main_mutex);
1864         spin_lock_irqsave(&device->resource->req_lock, flags);
1865         /* to have a stable device->state.role
1866          * and no race with updating open_cnt */
1867
1868         if (device->state.role != R_PRIMARY) {
1869                 if (mode & FMODE_WRITE)
1870                         rv = -EROFS;
1871                 else if (!allow_oos)
1872                         rv = -EMEDIUMTYPE;
1873         }
1874
1875         if (!rv)
1876                 device->open_cnt++;
1877         spin_unlock_irqrestore(&device->resource->req_lock, flags);
1878         mutex_unlock(&drbd_main_mutex);
1879
1880         return rv;
1881 }
1882
1883 static void drbd_release(struct gendisk *gd, fmode_t mode)
1884 {
1885         struct drbd_device *device = gd->private_data;
1886         mutex_lock(&drbd_main_mutex);
1887         device->open_cnt--;
1888         mutex_unlock(&drbd_main_mutex);
1889 }
1890
1891 static void drbd_set_defaults(struct drbd_device *device)
1892 {
1893         /* Beware! The actual layout differs
1894          * between big endian and little endian */
1895         device->state = (union drbd_dev_state) {
1896                 { .role = R_SECONDARY,
1897                   .peer = R_UNKNOWN,
1898                   .conn = C_STANDALONE,
1899                   .disk = D_DISKLESS,
1900                   .pdsk = D_UNKNOWN,
1901                 } };
1902 }
1903
1904 void drbd_init_set_defaults(struct drbd_device *device)
1905 {
1906         /* the memset(,0,) did most of this.
1907          * note: only assignments, no allocation in here */
1908
1909         drbd_set_defaults(device);
1910
1911         atomic_set(&device->ap_bio_cnt, 0);
1912         atomic_set(&device->ap_actlog_cnt, 0);
1913         atomic_set(&device->ap_pending_cnt, 0);
1914         atomic_set(&device->rs_pending_cnt, 0);
1915         atomic_set(&device->unacked_cnt, 0);
1916         atomic_set(&device->local_cnt, 0);
1917         atomic_set(&device->pp_in_use_by_net, 0);
1918         atomic_set(&device->rs_sect_in, 0);
1919         atomic_set(&device->rs_sect_ev, 0);
1920         atomic_set(&device->ap_in_flight, 0);
1921         atomic_set(&device->md_io.in_use, 0);
1922
1923         mutex_init(&device->own_state_mutex);
1924         device->state_mutex = &device->own_state_mutex;
1925
1926         spin_lock_init(&device->al_lock);
1927         spin_lock_init(&device->peer_seq_lock);
1928
1929         INIT_LIST_HEAD(&device->active_ee);
1930         INIT_LIST_HEAD(&device->sync_ee);
1931         INIT_LIST_HEAD(&device->done_ee);
1932         INIT_LIST_HEAD(&device->read_ee);
1933         INIT_LIST_HEAD(&device->net_ee);
1934         INIT_LIST_HEAD(&device->resync_reads);
1935         INIT_LIST_HEAD(&device->resync_work.list);
1936         INIT_LIST_HEAD(&device->unplug_work.list);
1937         INIT_LIST_HEAD(&device->bm_io_work.w.list);
1938         INIT_LIST_HEAD(&device->pending_master_completion[0]);
1939         INIT_LIST_HEAD(&device->pending_master_completion[1]);
1940         INIT_LIST_HEAD(&device->pending_completion[0]);
1941         INIT_LIST_HEAD(&device->pending_completion[1]);
1942
1943         device->resync_work.cb  = w_resync_timer;
1944         device->unplug_work.cb  = w_send_write_hint;
1945         device->bm_io_work.w.cb = w_bitmap_io;
1946
1947         init_timer(&device->resync_timer);
1948         init_timer(&device->md_sync_timer);
1949         init_timer(&device->start_resync_timer);
1950         init_timer(&device->request_timer);
1951         device->resync_timer.function = resync_timer_fn;
1952         device->resync_timer.data = (unsigned long) device;
1953         device->md_sync_timer.function = md_sync_timer_fn;
1954         device->md_sync_timer.data = (unsigned long) device;
1955         device->start_resync_timer.function = start_resync_timer_fn;
1956         device->start_resync_timer.data = (unsigned long) device;
1957         device->request_timer.function = request_timer_fn;
1958         device->request_timer.data = (unsigned long) device;
1959
1960         init_waitqueue_head(&device->misc_wait);
1961         init_waitqueue_head(&device->state_wait);
1962         init_waitqueue_head(&device->ee_wait);
1963         init_waitqueue_head(&device->al_wait);
1964         init_waitqueue_head(&device->seq_wait);
1965
1966         device->resync_wenr = LC_FREE;
1967         device->peer_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
1968         device->local_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
1969 }
1970
1971 void drbd_device_cleanup(struct drbd_device *device)
1972 {
1973         int i;
1974         if (first_peer_device(device)->connection->receiver.t_state != NONE)
1975                 drbd_err(device, "ASSERT FAILED: receiver t_state == %d expected 0.\n",
1976                                 first_peer_device(device)->connection->receiver.t_state);
1977
1978         device->al_writ_cnt  =
1979         device->bm_writ_cnt  =
1980         device->read_cnt     =
1981         device->recv_cnt     =
1982         device->send_cnt     =
1983         device->writ_cnt     =
1984         device->p_size       =
1985         device->rs_start     =
1986         device->rs_total     =
1987         device->rs_failed    = 0;
1988         device->rs_last_events = 0;
1989         device->rs_last_sect_ev = 0;
1990         for (i = 0; i < DRBD_SYNC_MARKS; i++) {
1991                 device->rs_mark_left[i] = 0;
1992                 device->rs_mark_time[i] = 0;
1993         }
1994         D_ASSERT(device, first_peer_device(device)->connection->net_conf == NULL);
1995
1996         drbd_set_my_capacity(device, 0);
1997         if (device->bitmap) {
1998                 /* maybe never allocated. */
1999                 drbd_bm_resize(device, 0, 1);
2000                 drbd_bm_cleanup(device);
2001         }
2002
2003         drbd_free_ldev(device->ldev);
2004         device->ldev = NULL;
2005
2006         clear_bit(AL_SUSPENDED, &device->flags);
2007
2008         D_ASSERT(device, list_empty(&device->active_ee));
2009         D_ASSERT(device, list_empty(&device->sync_ee));
2010         D_ASSERT(device, list_empty(&device->done_ee));
2011         D_ASSERT(device, list_empty(&device->read_ee));
2012         D_ASSERT(device, list_empty(&device->net_ee));
2013         D_ASSERT(device, list_empty(&device->resync_reads));
2014         D_ASSERT(device, list_empty(&first_peer_device(device)->connection->sender_work.q));
2015         D_ASSERT(device, list_empty(&device->resync_work.list));
2016         D_ASSERT(device, list_empty(&device->unplug_work.list));
2017
2018         drbd_set_defaults(device);
2019 }
2020
2021
2022 static void drbd_destroy_mempools(void)
2023 {
2024         struct page *page;
2025
2026         while (drbd_pp_pool) {
2027                 page = drbd_pp_pool;
2028                 drbd_pp_pool = (struct page *)page_private(page);
2029                 __free_page(page);
2030                 drbd_pp_vacant--;
2031         }
2032
2033         /* D_ASSERT(device, atomic_read(&drbd_pp_vacant)==0); */
2034
2035         if (drbd_md_io_bio_set)
2036                 bioset_free(drbd_md_io_bio_set);
2037         if (drbd_md_io_page_pool)
2038                 mempool_destroy(drbd_md_io_page_pool);
2039         if (drbd_ee_mempool)
2040                 mempool_destroy(drbd_ee_mempool);
2041         if (drbd_request_mempool)
2042                 mempool_destroy(drbd_request_mempool);
2043         if (drbd_ee_cache)
2044                 kmem_cache_destroy(drbd_ee_cache);
2045         if (drbd_request_cache)
2046                 kmem_cache_destroy(drbd_request_cache);
2047         if (drbd_bm_ext_cache)
2048                 kmem_cache_destroy(drbd_bm_ext_cache);
2049         if (drbd_al_ext_cache)
2050                 kmem_cache_destroy(drbd_al_ext_cache);
2051
2052         drbd_md_io_bio_set   = NULL;
2053         drbd_md_io_page_pool = NULL;
2054         drbd_ee_mempool      = NULL;
2055         drbd_request_mempool = NULL;
2056         drbd_ee_cache        = NULL;
2057         drbd_request_cache   = NULL;
2058         drbd_bm_ext_cache    = NULL;
2059         drbd_al_ext_cache    = NULL;
2060
2061         return;
2062 }
2063
2064 static int drbd_create_mempools(void)
2065 {
2066         struct page *page;
2067         const int number = (DRBD_MAX_BIO_SIZE/PAGE_SIZE) * minor_count;
2068         int i;
2069
2070         /* prepare our caches and mempools */
2071         drbd_request_mempool = NULL;
2072         drbd_ee_cache        = NULL;
2073         drbd_request_cache   = NULL;
2074         drbd_bm_ext_cache    = NULL;
2075         drbd_al_ext_cache    = NULL;
2076         drbd_pp_pool         = NULL;
2077         drbd_md_io_page_pool = NULL;
2078         drbd_md_io_bio_set   = NULL;
2079
2080         /* caches */
2081         drbd_request_cache = kmem_cache_create(
2082                 "drbd_req", sizeof(struct drbd_request), 0, 0, NULL);
2083         if (drbd_request_cache == NULL)
2084                 goto Enomem;
2085
2086         drbd_ee_cache = kmem_cache_create(
2087                 "drbd_ee", sizeof(struct drbd_peer_request), 0, 0, NULL);
2088         if (drbd_ee_cache == NULL)
2089                 goto Enomem;
2090
2091         drbd_bm_ext_cache = kmem_cache_create(
2092                 "drbd_bm", sizeof(struct bm_extent), 0, 0, NULL);
2093         if (drbd_bm_ext_cache == NULL)
2094                 goto Enomem;
2095
2096         drbd_al_ext_cache = kmem_cache_create(
2097                 "drbd_al", sizeof(struct lc_element), 0, 0, NULL);
2098         if (drbd_al_ext_cache == NULL)
2099                 goto Enomem;
2100
2101         /* mempools */
2102         drbd_md_io_bio_set = bioset_create(DRBD_MIN_POOL_PAGES, 0);
2103         if (drbd_md_io_bio_set == NULL)
2104                 goto Enomem;
2105
2106         drbd_md_io_page_pool = mempool_create_page_pool(DRBD_MIN_POOL_PAGES, 0);
2107         if (drbd_md_io_page_pool == NULL)
2108                 goto Enomem;
2109
2110         drbd_request_mempool = mempool_create(number,
2111                 mempool_alloc_slab, mempool_free_slab, drbd_request_cache);
2112         if (drbd_request_mempool == NULL)
2113                 goto Enomem;
2114
2115         drbd_ee_mempool = mempool_create(number,
2116                 mempool_alloc_slab, mempool_free_slab, drbd_ee_cache);
2117         if (drbd_ee_mempool == NULL)
2118                 goto Enomem;
2119
2120         /* drbd's page pool */
2121         spin_lock_init(&drbd_pp_lock);
2122
2123         for (i = 0; i < number; i++) {
2124                 page = alloc_page(GFP_HIGHUSER);
2125                 if (!page)
2126                         goto Enomem;
2127                 set_page_private(page, (unsigned long)drbd_pp_pool);
2128                 drbd_pp_pool = page;
2129         }
2130         drbd_pp_vacant = number;
2131
2132         return 0;
2133
2134 Enomem:
2135         drbd_destroy_mempools(); /* in case we allocated some */
2136         return -ENOMEM;
2137 }
2138
2139 static void drbd_release_all_peer_reqs(struct drbd_device *device)
2140 {
2141         int rr;
2142
2143         rr = drbd_free_peer_reqs(device, &device->active_ee);
2144         if (rr)
2145                 drbd_err(device, "%d EEs in active list found!\n", rr);
2146
2147         rr = drbd_free_peer_reqs(device, &device->sync_ee);
2148         if (rr)
2149                 drbd_err(device, "%d EEs in sync list found!\n", rr);
2150
2151         rr = drbd_free_peer_reqs(device, &device->read_ee);
2152         if (rr)
2153                 drbd_err(device, "%d EEs in read list found!\n", rr);
2154
2155         rr = drbd_free_peer_reqs(device, &device->done_ee);
2156         if (rr)
2157                 drbd_err(device, "%d EEs in done list found!\n", rr);
2158
2159         rr = drbd_free_peer_reqs(device, &device->net_ee);
2160         if (rr)
2161                 drbd_err(device, "%d EEs in net list found!\n", rr);
2162 }
2163
2164 /* caution. no locking. */
2165 void drbd_destroy_device(struct kref *kref)
2166 {
2167         struct drbd_device *device = container_of(kref, struct drbd_device, kref);
2168         struct drbd_resource *resource = device->resource;
2169         struct drbd_peer_device *peer_device, *tmp_peer_device;
2170
2171         del_timer_sync(&device->request_timer);
2172
2173         /* paranoia asserts */
2174         D_ASSERT(device, device->open_cnt == 0);
2175         /* end paranoia asserts */
2176
2177         /* cleanup stuff that may have been allocated during
2178          * device (re-)configuration or state changes */
2179
2180         if (device->this_bdev)
2181                 bdput(device->this_bdev);
2182
2183         drbd_free_ldev(device->ldev);
2184         device->ldev = NULL;
2185
2186         drbd_release_all_peer_reqs(device);
2187
2188         lc_destroy(device->act_log);
2189         lc_destroy(device->resync);
2190
2191         kfree(device->p_uuid);
2192         /* device->p_uuid = NULL; */
2193
2194         if (device->bitmap) /* should no longer be there. */
2195                 drbd_bm_cleanup(device);
2196         __free_page(device->md_io.page);
2197         put_disk(device->vdisk);
2198         blk_cleanup_queue(device->rq_queue);
2199         kfree(device->rs_plan_s);
2200
2201         /* not for_each_connection(connection, resource):
2202          * those may have been cleaned up and disassociated already.
2203          */
2204         for_each_peer_device_safe(peer_device, tmp_peer_device, device) {
2205                 kref_put(&peer_device->connection->kref, drbd_destroy_connection);
2206                 kfree(peer_device);
2207         }
2208         memset(device, 0xfd, sizeof(*device));
2209         kfree(device);
2210         kref_put(&resource->kref, drbd_destroy_resource);
2211 }
2212
2213 /* One global retry thread, if we need to push back some bio and have it
2214  * reinserted through our make request function.
2215  */
2216 static struct retry_worker {
2217         struct workqueue_struct *wq;
2218         struct work_struct worker;
2219
2220         spinlock_t lock;
2221         struct list_head writes;
2222 } retry;
2223
2224 static void do_retry(struct work_struct *ws)
2225 {
2226         struct retry_worker *retry = container_of(ws, struct retry_worker, worker);
2227         LIST_HEAD(writes);
2228         struct drbd_request *req, *tmp;
2229
2230         spin_lock_irq(&retry->lock);
2231         list_splice_init(&retry->writes, &writes);
2232         spin_unlock_irq(&retry->lock);
2233
2234         list_for_each_entry_safe(req, tmp, &writes, tl_requests) {
2235                 struct drbd_device *device = req->device;
2236                 struct bio *bio = req->master_bio;
2237                 unsigned long start_jif = req->start_jif;
2238                 bool expected;
2239
2240                 expected =
2241                         expect(atomic_read(&req->completion_ref) == 0) &&
2242                         expect(req->rq_state & RQ_POSTPONED) &&
2243                         expect((req->rq_state & RQ_LOCAL_PENDING) == 0 ||
2244                                 (req->rq_state & RQ_LOCAL_ABORTED) != 0);
2245
2246                 if (!expected)
2247                         drbd_err(device, "req=%p completion_ref=%d rq_state=%x\n",
2248                                 req, atomic_read(&req->completion_ref),
2249                                 req->rq_state);
2250
2251                 /* We still need to put one kref associated with the
2252                  * "completion_ref" going zero in the code path that queued it
2253                  * here.  The request object may still be referenced by a
2254                  * frozen local req->private_bio, in case we force-detached.
2255                  */
2256                 kref_put(&req->kref, drbd_req_destroy);
2257
2258                 /* A single suspended or otherwise blocking device may stall
2259                  * all others as well.  Fortunately, this code path is to
2260                  * recover from a situation that "should not happen":
2261                  * concurrent writes in multi-primary setup.
2262                  * In a "normal" lifecycle, this workqueue is supposed to be
2263                  * destroyed without ever doing anything.
2264                  * If it turns out to be an issue anyways, we can do per
2265                  * resource (replication group) or per device (minor) retry
2266                  * workqueues instead.
2267                  */
2268
2269                 /* We are not just doing generic_make_request(),
2270                  * as we want to keep the start_time information. */
2271                 inc_ap_bio(device);
2272                 __drbd_make_request(device, bio, start_jif);
2273         }
2274 }
2275
2276 /* called via drbd_req_put_completion_ref(),
2277  * holds resource->req_lock */
2278 void drbd_restart_request(struct drbd_request *req)
2279 {
2280         unsigned long flags;
2281         spin_lock_irqsave(&retry.lock, flags);
2282         list_move_tail(&req->tl_requests, &retry.writes);
2283         spin_unlock_irqrestore(&retry.lock, flags);
2284
2285         /* Drop the extra reference that would otherwise
2286          * have been dropped by complete_master_bio.
2287          * do_retry() needs to grab a new one. */
2288         dec_ap_bio(req->device);
2289
2290         queue_work(retry.wq, &retry.worker);
2291 }
2292
2293 void drbd_destroy_resource(struct kref *kref)
2294 {
2295         struct drbd_resource *resource =
2296                 container_of(kref, struct drbd_resource, kref);
2297
2298         idr_destroy(&resource->devices);
2299         free_cpumask_var(resource->cpu_mask);
2300         kfree(resource->name);
2301         memset(resource, 0xf2, sizeof(*resource));
2302         kfree(resource);
2303 }
2304
2305 void drbd_free_resource(struct drbd_resource *resource)
2306 {
2307         struct drbd_connection *connection, *tmp;
2308
2309         for_each_connection_safe(connection, tmp, resource) {
2310                 list_del(&connection->connections);
2311                 drbd_debugfs_connection_cleanup(connection);
2312                 kref_put(&connection->kref, drbd_destroy_connection);
2313         }
2314         drbd_debugfs_resource_cleanup(resource);
2315         kref_put(&resource->kref, drbd_destroy_resource);
2316 }
2317
2318 static void drbd_cleanup(void)
2319 {
2320         unsigned int i;
2321         struct drbd_device *device;
2322         struct drbd_resource *resource, *tmp;
2323
2324         /* first remove proc,
2325          * drbdsetup uses it's presence to detect
2326          * whether DRBD is loaded.
2327          * If we would get stuck in proc removal,
2328          * but have netlink already deregistered,
2329          * some drbdsetup commands may wait forever
2330          * for an answer.
2331          */
2332         if (drbd_proc)
2333                 remove_proc_entry("drbd", NULL);
2334
2335         if (retry.wq)
2336                 destroy_workqueue(retry.wq);
2337
2338         drbd_genl_unregister();
2339         drbd_debugfs_cleanup();
2340
2341         idr_for_each_entry(&drbd_devices, device, i)
2342                 drbd_delete_device(device);
2343
2344         /* not _rcu since, no other updater anymore. Genl already unregistered */
2345         for_each_resource_safe(resource, tmp, &drbd_resources) {
2346                 list_del(&resource->resources);
2347                 drbd_free_resource(resource);
2348         }
2349
2350         drbd_destroy_mempools();
2351         unregister_blkdev(DRBD_MAJOR, "drbd");
2352
2353         idr_destroy(&drbd_devices);
2354
2355         pr_info("module cleanup done.\n");
2356 }
2357
2358 /**
2359  * drbd_congested() - Callback for the flusher thread
2360  * @congested_data:     User data
2361  * @bdi_bits:           Bits the BDI flusher thread is currently interested in
2362  *
2363  * Returns 1<<BDI_async_congested and/or 1<<BDI_sync_congested if we are congested.
2364  */
2365 static int drbd_congested(void *congested_data, int bdi_bits)
2366 {
2367         struct drbd_device *device = congested_data;
2368         struct request_queue *q;
2369         char reason = '-';
2370         int r = 0;
2371
2372         if (!may_inc_ap_bio(device)) {
2373                 /* DRBD has frozen IO */
2374                 r = bdi_bits;
2375                 reason = 'd';
2376                 goto out;
2377         }
2378
2379         if (test_bit(CALLBACK_PENDING, &first_peer_device(device)->connection->flags)) {
2380                 r |= (1 << BDI_async_congested);
2381                 /* Without good local data, we would need to read from remote,
2382                  * and that would need the worker thread as well, which is
2383                  * currently blocked waiting for that usermode helper to
2384                  * finish.
2385                  */
2386                 if (!get_ldev_if_state(device, D_UP_TO_DATE))
2387                         r |= (1 << BDI_sync_congested);
2388                 else
2389                         put_ldev(device);
2390                 r &= bdi_bits;
2391                 reason = 'c';
2392                 goto out;
2393         }
2394
2395         if (get_ldev(device)) {
2396                 q = bdev_get_queue(device->ldev->backing_bdev);
2397                 r = bdi_congested(&q->backing_dev_info, bdi_bits);
2398                 put_ldev(device);
2399                 if (r)
2400                         reason = 'b';
2401         }
2402
2403         if (bdi_bits & (1 << BDI_async_congested) &&
2404             test_bit(NET_CONGESTED, &first_peer_device(device)->connection->flags)) {
2405                 r |= (1 << BDI_async_congested);
2406                 reason = reason == 'b' ? 'a' : 'n';
2407         }
2408
2409 out:
2410         device->congestion_reason = reason;
2411         return r;
2412 }
2413
2414 static void drbd_init_workqueue(struct drbd_work_queue* wq)
2415 {
2416         spin_lock_init(&wq->q_lock);
2417         INIT_LIST_HEAD(&wq->q);
2418         init_waitqueue_head(&wq->q_wait);
2419 }
2420
2421 struct completion_work {
2422         struct drbd_work w;
2423         struct completion done;
2424 };
2425
2426 static int w_complete(struct drbd_work *w, int cancel)
2427 {
2428         struct completion_work *completion_work =
2429                 container_of(w, struct completion_work, w);
2430
2431         complete(&completion_work->done);
2432         return 0;
2433 }
2434
2435 void drbd_flush_workqueue(struct drbd_work_queue *work_queue)
2436 {
2437         struct completion_work completion_work;
2438
2439         completion_work.w.cb = w_complete;
2440         init_completion(&completion_work.done);
2441         drbd_queue_work(work_queue, &completion_work.w);
2442         wait_for_completion(&completion_work.done);
2443 }
2444
2445 struct drbd_resource *drbd_find_resource(const char *name)
2446 {
2447         struct drbd_resource *resource;
2448
2449         if (!name || !name[0])
2450                 return NULL;
2451
2452         rcu_read_lock();
2453         for_each_resource_rcu(resource, &drbd_resources) {
2454                 if (!strcmp(resource->name, name)) {
2455                         kref_get(&resource->kref);
2456                         goto found;
2457                 }
2458         }
2459         resource = NULL;
2460 found:
2461         rcu_read_unlock();
2462         return resource;
2463 }
2464
2465 struct drbd_connection *conn_get_by_addrs(void *my_addr, int my_addr_len,
2466                                      void *peer_addr, int peer_addr_len)
2467 {
2468         struct drbd_resource *resource;
2469         struct drbd_connection *connection;
2470
2471         rcu_read_lock();
2472         for_each_resource_rcu(resource, &drbd_resources) {
2473                 for_each_connection_rcu(connection, resource) {
2474                         if (connection->my_addr_len == my_addr_len &&
2475                             connection->peer_addr_len == peer_addr_len &&
2476                             !memcmp(&connection->my_addr, my_addr, my_addr_len) &&
2477                             !memcmp(&connection->peer_addr, peer_addr, peer_addr_len)) {
2478                                 kref_get(&connection->kref);
2479                                 goto found;
2480                         }
2481                 }
2482         }
2483         connection = NULL;
2484 found:
2485         rcu_read_unlock();
2486         return connection;
2487 }
2488
2489 static int drbd_alloc_socket(struct drbd_socket *socket)
2490 {
2491         socket->rbuf = (void *) __get_free_page(GFP_KERNEL);
2492         if (!socket->rbuf)
2493                 return -ENOMEM;
2494         socket->sbuf = (void *) __get_free_page(GFP_KERNEL);
2495         if (!socket->sbuf)
2496                 return -ENOMEM;
2497         return 0;
2498 }
2499
2500 static void drbd_free_socket(struct drbd_socket *socket)
2501 {
2502         free_page((unsigned long) socket->sbuf);
2503         free_page((unsigned long) socket->rbuf);
2504 }
2505
2506 void conn_free_crypto(struct drbd_connection *connection)
2507 {
2508         drbd_free_sock(connection);
2509
2510         crypto_free_hash(connection->csums_tfm);
2511         crypto_free_hash(connection->verify_tfm);
2512         crypto_free_hash(connection->cram_hmac_tfm);
2513         crypto_free_hash(connection->integrity_tfm);
2514         crypto_free_hash(connection->peer_integrity_tfm);
2515         kfree(connection->int_dig_in);
2516         kfree(connection->int_dig_vv);
2517
2518         connection->csums_tfm = NULL;
2519         connection->verify_tfm = NULL;
2520         connection->cram_hmac_tfm = NULL;
2521         connection->integrity_tfm = NULL;
2522         connection->peer_integrity_tfm = NULL;
2523         connection->int_dig_in = NULL;
2524         connection->int_dig_vv = NULL;
2525 }
2526
2527 int set_resource_options(struct drbd_resource *resource, struct res_opts *res_opts)
2528 {
2529         struct drbd_connection *connection;
2530         cpumask_var_t new_cpu_mask;
2531         int err;
2532
2533         if (!zalloc_cpumask_var(&new_cpu_mask, GFP_KERNEL))
2534                 return -ENOMEM;
2535
2536         /* silently ignore cpu mask on UP kernel */
2537         if (nr_cpu_ids > 1 && res_opts->cpu_mask[0] != 0) {
2538                 err = bitmap_parse(res_opts->cpu_mask, DRBD_CPU_MASK_SIZE,
2539                                    cpumask_bits(new_cpu_mask), nr_cpu_ids);
2540                 if (err == -EOVERFLOW) {
2541                         /* So what. mask it out. */
2542                         cpumask_var_t tmp_cpu_mask;
2543                         if (zalloc_cpumask_var(&tmp_cpu_mask, GFP_KERNEL)) {
2544                                 cpumask_setall(tmp_cpu_mask);
2545                                 cpumask_and(new_cpu_mask, new_cpu_mask, tmp_cpu_mask);
2546                                 drbd_warn(resource, "Overflow in bitmap_parse(%.12s%s), truncating to %u bits\n",
2547                                         res_opts->cpu_mask,
2548                                         strlen(res_opts->cpu_mask) > 12 ? "..." : "",
2549                                         nr_cpu_ids);
2550                                 free_cpumask_var(tmp_cpu_mask);
2551                                 err = 0;
2552                         }
2553                 }
2554                 if (err) {
2555                         drbd_warn(resource, "bitmap_parse() failed with %d\n", err);
2556                         /* retcode = ERR_CPU_MASK_PARSE; */
2557                         goto fail;
2558                 }
2559         }
2560         resource->res_opts = *res_opts;
2561         if (cpumask_empty(new_cpu_mask))
2562                 drbd_calc_cpu_mask(&new_cpu_mask);
2563         if (!cpumask_equal(resource->cpu_mask, new_cpu_mask)) {
2564                 cpumask_copy(resource->cpu_mask, new_cpu_mask);
2565                 for_each_connection_rcu(connection, resource) {
2566                         connection->receiver.reset_cpu_mask = 1;
2567                         connection->asender.reset_cpu_mask = 1;
2568                         connection->worker.reset_cpu_mask = 1;
2569                 }
2570         }
2571         err = 0;
2572
2573 fail:
2574         free_cpumask_var(new_cpu_mask);
2575         return err;
2576
2577 }
2578
2579 struct drbd_resource *drbd_create_resource(const char *name)
2580 {
2581         struct drbd_resource *resource;
2582
2583         resource = kzalloc(sizeof(struct drbd_resource), GFP_KERNEL);
2584         if (!resource)
2585                 goto fail;
2586         resource->name = kstrdup(name, GFP_KERNEL);
2587         if (!resource->name)
2588                 goto fail_free_resource;
2589         if (!zalloc_cpumask_var(&resource->cpu_mask, GFP_KERNEL))
2590                 goto fail_free_name;
2591         kref_init(&resource->kref);
2592         idr_init(&resource->devices);
2593         INIT_LIST_HEAD(&resource->connections);
2594         resource->write_ordering = WO_bdev_flush;
2595         list_add_tail_rcu(&resource->resources, &drbd_resources);
2596         mutex_init(&resource->conf_update);
2597         mutex_init(&resource->adm_mutex);
2598         spin_lock_init(&resource->req_lock);
2599         drbd_debugfs_resource_add(resource);
2600         return resource;
2601
2602 fail_free_name:
2603         kfree(resource->name);
2604 fail_free_resource:
2605         kfree(resource);
2606 fail:
2607         return NULL;
2608 }
2609
2610 /* caller must be under adm_mutex */
2611 struct drbd_connection *conn_create(const char *name, struct res_opts *res_opts)
2612 {
2613         struct drbd_resource *resource;
2614         struct drbd_connection *connection;
2615
2616         connection = kzalloc(sizeof(struct drbd_connection), GFP_KERNEL);
2617         if (!connection)
2618                 return NULL;
2619
2620         if (drbd_alloc_socket(&connection->data))
2621                 goto fail;
2622         if (drbd_alloc_socket(&connection->meta))
2623                 goto fail;
2624
2625         connection->current_epoch = kzalloc(sizeof(struct drbd_epoch), GFP_KERNEL);
2626         if (!connection->current_epoch)
2627                 goto fail;
2628
2629         INIT_LIST_HEAD(&connection->transfer_log);
2630
2631         INIT_LIST_HEAD(&connection->current_epoch->list);
2632         connection->epochs = 1;
2633         spin_lock_init(&connection->epoch_lock);
2634
2635         connection->send.seen_any_write_yet = false;
2636         connection->send.current_epoch_nr = 0;
2637         connection->send.current_epoch_writes = 0;
2638
2639         resource = drbd_create_resource(name);
2640         if (!resource)
2641                 goto fail;
2642
2643         connection->cstate = C_STANDALONE;
2644         mutex_init(&connection->cstate_mutex);
2645         init_waitqueue_head(&connection->ping_wait);
2646         idr_init(&connection->peer_devices);
2647
2648         drbd_init_workqueue(&connection->sender_work);
2649         mutex_init(&connection->data.mutex);
2650         mutex_init(&connection->meta.mutex);
2651
2652         drbd_thread_init(resource, &connection->receiver, drbd_receiver, "receiver");
2653         connection->receiver.connection = connection;
2654         drbd_thread_init(resource, &connection->worker, drbd_worker, "worker");
2655         connection->worker.connection = connection;
2656         drbd_thread_init(resource, &connection->asender, drbd_asender, "asender");
2657         connection->asender.connection = connection;
2658
2659         kref_init(&connection->kref);
2660
2661         connection->resource = resource;
2662
2663         if (set_resource_options(resource, res_opts))
2664                 goto fail_resource;
2665
2666         kref_get(&resource->kref);
2667         list_add_tail_rcu(&connection->connections, &resource->connections);
2668         drbd_debugfs_connection_add(connection);
2669         return connection;
2670
2671 fail_resource:
2672         list_del(&resource->resources);
2673         drbd_free_resource(resource);
2674 fail:
2675         kfree(connection->current_epoch);
2676         drbd_free_socket(&connection->meta);
2677         drbd_free_socket(&connection->data);
2678         kfree(connection);
2679         return NULL;
2680 }
2681
2682 void drbd_destroy_connection(struct kref *kref)
2683 {
2684         struct drbd_connection *connection = container_of(kref, struct drbd_connection, kref);
2685         struct drbd_resource *resource = connection->resource;
2686
2687         if (atomic_read(&connection->current_epoch->epoch_size) !=  0)
2688                 drbd_err(connection, "epoch_size:%d\n", atomic_read(&connection->current_epoch->epoch_size));
2689         kfree(connection->current_epoch);
2690
2691         idr_destroy(&connection->peer_devices);
2692
2693         drbd_free_socket(&connection->meta);
2694         drbd_free_socket(&connection->data);
2695         kfree(connection->int_dig_in);
2696         kfree(connection->int_dig_vv);
2697         memset(connection, 0xfc, sizeof(*connection));
2698         kfree(connection);
2699         kref_put(&resource->kref, drbd_destroy_resource);
2700 }
2701
2702 static int init_submitter(struct drbd_device *device)
2703 {
2704         /* opencoded create_singlethread_workqueue(),
2705          * to be able to say "drbd%d", ..., minor */
2706         device->submit.wq = alloc_workqueue("drbd%u_submit",
2707                         WQ_UNBOUND | WQ_MEM_RECLAIM, 1, device->minor);
2708         if (!device->submit.wq)
2709                 return -ENOMEM;
2710
2711         INIT_WORK(&device->submit.worker, do_submit);
2712         INIT_LIST_HEAD(&device->submit.writes);
2713         return 0;
2714 }
2715
2716 enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsigned int minor)
2717 {
2718         struct drbd_resource *resource = adm_ctx->resource;
2719         struct drbd_connection *connection;
2720         struct drbd_device *device;
2721         struct drbd_peer_device *peer_device, *tmp_peer_device;
2722         struct gendisk *disk;
2723         struct request_queue *q;
2724         int id;
2725         int vnr = adm_ctx->volume;
2726         enum drbd_ret_code err = ERR_NOMEM;
2727
2728         device = minor_to_device(minor);
2729         if (device)
2730                 return ERR_MINOR_OR_VOLUME_EXISTS;
2731
2732         /* GFP_KERNEL, we are outside of all write-out paths */
2733         device = kzalloc(sizeof(struct drbd_device), GFP_KERNEL);
2734         if (!device)
2735                 return ERR_NOMEM;
2736         kref_init(&device->kref);
2737
2738         kref_get(&resource->kref);
2739         device->resource = resource;
2740         device->minor = minor;
2741         device->vnr = vnr;
2742
2743         drbd_init_set_defaults(device);
2744
2745         q = blk_alloc_queue(GFP_KERNEL);
2746         if (!q)
2747                 goto out_no_q;
2748         device->rq_queue = q;
2749         q->queuedata   = device;
2750
2751         disk = alloc_disk(1);
2752         if (!disk)
2753                 goto out_no_disk;
2754         device->vdisk = disk;
2755
2756         set_disk_ro(disk, true);
2757
2758         disk->queue = q;
2759         disk->major = DRBD_MAJOR;
2760         disk->first_minor = minor;
2761         disk->fops = &drbd_ops;
2762         sprintf(disk->disk_name, "drbd%d", minor);
2763         disk->private_data = device;
2764
2765         device->this_bdev = bdget(MKDEV(DRBD_MAJOR, minor));
2766         /* we have no partitions. we contain only ourselves. */
2767         device->this_bdev->bd_contains = device->this_bdev;
2768
2769         q->backing_dev_info.congested_fn = drbd_congested;
2770         q->backing_dev_info.congested_data = device;
2771
2772         blk_queue_make_request(q, drbd_make_request);
2773         blk_queue_flush(q, REQ_FLUSH | REQ_FUA);
2774         /* Setting the max_hw_sectors to an odd value of 8kibyte here
2775            This triggers a max_bio_size message upon first attach or connect */
2776         blk_queue_max_hw_sectors(q, DRBD_MAX_BIO_SIZE_SAFE >> 8);
2777         blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
2778         blk_queue_merge_bvec(q, drbd_merge_bvec);
2779         q->queue_lock = &resource->req_lock;
2780
2781         device->md_io.page = alloc_page(GFP_KERNEL);
2782         if (!device->md_io.page)
2783                 goto out_no_io_page;
2784
2785         if (drbd_bm_init(device))
2786                 goto out_no_bitmap;
2787         device->read_requests = RB_ROOT;
2788         device->write_requests = RB_ROOT;
2789
2790         id = idr_alloc(&drbd_devices, device, minor, minor + 1, GFP_KERNEL);
2791         if (id < 0) {
2792                 if (id == -ENOSPC)
2793                         err = ERR_MINOR_OR_VOLUME_EXISTS;
2794                 goto out_no_minor_idr;
2795         }
2796         kref_get(&device->kref);
2797
2798         id = idr_alloc(&resource->devices, device, vnr, vnr + 1, GFP_KERNEL);
2799         if (id < 0) {
2800                 if (id == -ENOSPC)
2801                         err = ERR_MINOR_OR_VOLUME_EXISTS;
2802                 goto out_idr_remove_minor;
2803         }
2804         kref_get(&device->kref);
2805
2806         INIT_LIST_HEAD(&device->peer_devices);
2807         INIT_LIST_HEAD(&device->pending_bitmap_io);
2808         for_each_connection(connection, resource) {
2809                 peer_device = kzalloc(sizeof(struct drbd_peer_device), GFP_KERNEL);
2810                 if (!peer_device)
2811                         goto out_idr_remove_from_resource;
2812                 peer_device->connection = connection;
2813                 peer_device->device = device;
2814
2815                 list_add(&peer_device->peer_devices, &device->peer_devices);
2816                 kref_get(&device->kref);
2817
2818                 id = idr_alloc(&connection->peer_devices, peer_device, vnr, vnr + 1, GFP_KERNEL);
2819                 if (id < 0) {
2820                         if (id == -ENOSPC)
2821                                 err = ERR_INVALID_REQUEST;
2822                         goto out_idr_remove_from_resource;
2823                 }
2824                 kref_get(&connection->kref);
2825         }
2826
2827         if (init_submitter(device)) {
2828                 err = ERR_NOMEM;
2829                 goto out_idr_remove_vol;
2830         }
2831
2832         add_disk(disk);
2833
2834         /* inherit the connection state */
2835         device->state.conn = first_connection(resource)->cstate;
2836         if (device->state.conn == C_WF_REPORT_PARAMS) {
2837                 for_each_peer_device(peer_device, device)
2838                         drbd_connected(peer_device);
2839         }
2840         /* move to create_peer_device() */
2841         for_each_peer_device(peer_device, device)
2842                 drbd_debugfs_peer_device_add(peer_device);
2843         drbd_debugfs_device_add(device);
2844         return NO_ERROR;
2845
2846 out_idr_remove_vol:
2847         idr_remove(&connection->peer_devices, vnr);
2848 out_idr_remove_from_resource:
2849         for_each_connection(connection, resource) {
2850                 peer_device = idr_find(&connection->peer_devices, vnr);
2851                 if (peer_device) {
2852                         idr_remove(&connection->peer_devices, vnr);
2853                         kref_put(&connection->kref, drbd_destroy_connection);
2854                 }
2855         }
2856         for_each_peer_device_safe(peer_device, tmp_peer_device, device) {
2857                 list_del(&peer_device->peer_devices);
2858                 kfree(peer_device);
2859         }
2860         idr_remove(&resource->devices, vnr);
2861 out_idr_remove_minor:
2862         idr_remove(&drbd_devices, minor);
2863         synchronize_rcu();
2864 out_no_minor_idr:
2865         drbd_bm_cleanup(device);
2866 out_no_bitmap:
2867         __free_page(device->md_io.page);
2868 out_no_io_page:
2869         put_disk(disk);
2870 out_no_disk:
2871         blk_cleanup_queue(q);
2872 out_no_q:
2873         kref_put(&resource->kref, drbd_destroy_resource);
2874         kfree(device);
2875         return err;
2876 }
2877
2878 void drbd_delete_device(struct drbd_device *device)
2879 {
2880         struct drbd_resource *resource = device->resource;
2881         struct drbd_connection *connection;
2882         struct drbd_peer_device *peer_device;
2883         int refs = 3;
2884
2885         /* move to free_peer_device() */
2886         for_each_peer_device(peer_device, device)
2887                 drbd_debugfs_peer_device_cleanup(peer_device);
2888         drbd_debugfs_device_cleanup(device);
2889         for_each_connection(connection, resource) {
2890                 idr_remove(&connection->peer_devices, device->vnr);
2891                 refs++;
2892         }
2893         idr_remove(&resource->devices, device->vnr);
2894         idr_remove(&drbd_devices, device_to_minor(device));
2895         del_gendisk(device->vdisk);
2896         synchronize_rcu();
2897         kref_sub(&device->kref, refs, drbd_destroy_device);
2898 }
2899
2900 static int __init drbd_init(void)
2901 {
2902         int err;
2903
2904         if (minor_count < DRBD_MINOR_COUNT_MIN || minor_count > DRBD_MINOR_COUNT_MAX) {
2905                 pr_err("invalid minor_count (%d)\n", minor_count);
2906 #ifdef MODULE
2907                 return -EINVAL;
2908 #else
2909                 minor_count = DRBD_MINOR_COUNT_DEF;
2910 #endif
2911         }
2912
2913         err = register_blkdev(DRBD_MAJOR, "drbd");
2914         if (err) {
2915                 pr_err("unable to register block device major %d\n",
2916                        DRBD_MAJOR);
2917                 return err;
2918         }
2919
2920         /*
2921          * allocate all necessary structs
2922          */
2923         init_waitqueue_head(&drbd_pp_wait);
2924
2925         drbd_proc = NULL; /* play safe for drbd_cleanup */
2926         idr_init(&drbd_devices);
2927
2928         rwlock_init(&global_state_lock);
2929         INIT_LIST_HEAD(&drbd_resources);
2930
2931         err = drbd_genl_register();
2932         if (err) {
2933                 pr_err("unable to register generic netlink family\n");
2934                 goto fail;
2935         }
2936
2937         err = drbd_create_mempools();
2938         if (err)
2939                 goto fail;
2940
2941         err = -ENOMEM;
2942         drbd_proc = proc_create_data("drbd", S_IFREG | S_IRUGO , NULL, &drbd_proc_fops, NULL);
2943         if (!drbd_proc) {
2944                 pr_err("unable to register proc file\n");
2945                 goto fail;
2946         }
2947
2948         retry.wq = create_singlethread_workqueue("drbd-reissue");
2949         if (!retry.wq) {
2950                 pr_err("unable to create retry workqueue\n");
2951                 goto fail;
2952         }
2953         INIT_WORK(&retry.worker, do_retry);
2954         spin_lock_init(&retry.lock);
2955         INIT_LIST_HEAD(&retry.writes);
2956
2957         if (drbd_debugfs_init())
2958                 pr_notice("failed to initialize debugfs -- will not be available\n");
2959
2960         pr_info("initialized. "
2961                "Version: " REL_VERSION " (api:%d/proto:%d-%d)\n",
2962                API_VERSION, PRO_VERSION_MIN, PRO_VERSION_MAX);
2963         pr_info("%s\n", drbd_buildtag());
2964         pr_info("registered as block device major %d\n", DRBD_MAJOR);
2965         return 0; /* Success! */
2966
2967 fail:
2968         drbd_cleanup();
2969         if (err == -ENOMEM)
2970                 pr_err("ran out of memory\n");
2971         else
2972                 pr_err("initialization failure\n");
2973         return err;
2974 }
2975
2976 void drbd_free_ldev(struct drbd_backing_dev *ldev)
2977 {
2978         if (ldev == NULL)
2979                 return;
2980
2981         blkdev_put(ldev->backing_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
2982         blkdev_put(ldev->md_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
2983
2984         kfree(ldev->disk_conf);
2985         kfree(ldev);
2986 }
2987
2988 static void drbd_free_one_sock(struct drbd_socket *ds)
2989 {
2990         struct socket *s;
2991         mutex_lock(&ds->mutex);
2992         s = ds->socket;
2993         ds->socket = NULL;
2994         mutex_unlock(&ds->mutex);
2995         if (s) {
2996                 /* so debugfs does not need to mutex_lock() */
2997                 synchronize_rcu();
2998                 kernel_sock_shutdown(s, SHUT_RDWR);
2999                 sock_release(s);
3000         }
3001 }
3002
3003 void drbd_free_sock(struct drbd_connection *connection)
3004 {
3005         if (connection->data.socket)
3006                 drbd_free_one_sock(&connection->data);
3007         if (connection->meta.socket)
3008                 drbd_free_one_sock(&connection->meta);
3009 }
3010
3011 /* meta data management */
3012
3013 void conn_md_sync(struct drbd_connection *connection)
3014 {
3015         struct drbd_peer_device *peer_device;
3016         int vnr;
3017
3018         rcu_read_lock();
3019         idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
3020                 struct drbd_device *device = peer_device->device;
3021
3022                 kref_get(&device->kref);
3023                 rcu_read_unlock();
3024                 drbd_md_sync(device);
3025                 kref_put(&device->kref, drbd_destroy_device);
3026                 rcu_read_lock();
3027         }
3028         rcu_read_unlock();
3029 }
3030
3031 /* aligned 4kByte */
3032 struct meta_data_on_disk {
3033         u64 la_size_sect;      /* last agreed size. */
3034         u64 uuid[UI_SIZE];   /* UUIDs. */
3035         u64 device_uuid;
3036         u64 reserved_u64_1;
3037         u32 flags;             /* MDF */
3038         u32 magic;
3039         u32 md_size_sect;
3040         u32 al_offset;         /* offset to this block */
3041         u32 al_nr_extents;     /* important for restoring the AL (userspace) */
3042               /* `-- act_log->nr_elements <-- ldev->dc.al_extents */
3043         u32 bm_offset;         /* offset to the bitmap, from here */
3044         u32 bm_bytes_per_bit;  /* BM_BLOCK_SIZE */
3045         u32 la_peer_max_bio_size;   /* last peer max_bio_size */
3046
3047         /* see al_tr_number_to_on_disk_sector() */
3048         u32 al_stripes;
3049         u32 al_stripe_size_4k;
3050
3051         u8 reserved_u8[4096 - (7*8 + 10*4)];
3052 } __packed;
3053
3054
3055
3056 void drbd_md_write(struct drbd_device *device, void *b)
3057 {
3058         struct meta_data_on_disk *buffer = b;
3059         sector_t sector;
3060         int i;
3061
3062         memset(buffer, 0, sizeof(*buffer));
3063
3064         buffer->la_size_sect = cpu_to_be64(drbd_get_capacity(device->this_bdev));
3065         for (i = UI_CURRENT; i < UI_SIZE; i++)
3066                 buffer->uuid[i] = cpu_to_be64(device->ldev->md.uuid[i]);
3067         buffer->flags = cpu_to_be32(device->ldev->md.flags);
3068         buffer->magic = cpu_to_be32(DRBD_MD_MAGIC_84_UNCLEAN);
3069
3070         buffer->md_size_sect  = cpu_to_be32(device->ldev->md.md_size_sect);
3071         buffer->al_offset     = cpu_to_be32(device->ldev->md.al_offset);
3072         buffer->al_nr_extents = cpu_to_be32(device->act_log->nr_elements);
3073         buffer->bm_bytes_per_bit = cpu_to_be32(BM_BLOCK_SIZE);
3074         buffer->device_uuid = cpu_to_be64(device->ldev->md.device_uuid);
3075
3076         buffer->bm_offset = cpu_to_be32(device->ldev->md.bm_offset);
3077         buffer->la_peer_max_bio_size = cpu_to_be32(device->peer_max_bio_size);
3078
3079         buffer->al_stripes = cpu_to_be32(device->ldev->md.al_stripes);
3080         buffer->al_stripe_size_4k = cpu_to_be32(device->ldev->md.al_stripe_size_4k);
3081
3082         D_ASSERT(device, drbd_md_ss(device->ldev) == device->ldev->md.md_offset);
3083         sector = device->ldev->md.md_offset;
3084
3085         if (drbd_md_sync_page_io(device, device->ldev, sector, WRITE)) {
3086                 /* this was a try anyways ... */
3087                 drbd_err(device, "meta data update failed!\n");
3088                 drbd_chk_io_error(device, 1, DRBD_META_IO_ERROR);
3089         }
3090 }
3091
3092 /**
3093  * drbd_md_sync() - Writes the meta data super block if the MD_DIRTY flag bit is set
3094  * @device:     DRBD device.
3095  */
3096 void drbd_md_sync(struct drbd_device *device)
3097 {
3098         struct meta_data_on_disk *buffer;
3099
3100         /* Don't accidentally change the DRBD meta data layout. */
3101         BUILD_BUG_ON(UI_SIZE != 4);
3102         BUILD_BUG_ON(sizeof(struct meta_data_on_disk) != 4096);
3103
3104         del_timer(&device->md_sync_timer);
3105         /* timer may be rearmed by drbd_md_mark_dirty() now. */
3106         if (!test_and_clear_bit(MD_DIRTY, &device->flags))
3107                 return;
3108
3109         /* We use here D_FAILED and not D_ATTACHING because we try to write
3110          * metadata even if we detach due to a disk failure! */
3111         if (!get_ldev_if_state(device, D_FAILED))
3112                 return;
3113
3114         buffer = drbd_md_get_buffer(device, __func__);
3115         if (!buffer)
3116                 goto out;
3117
3118         drbd_md_write(device, buffer);
3119
3120         /* Update device->ldev->md.la_size_sect,
3121          * since we updated it on metadata. */
3122         device->ldev->md.la_size_sect = drbd_get_capacity(device->this_bdev);
3123
3124         drbd_md_put_buffer(device);
3125 out:
3126         put_ldev(device);
3127 }
3128
3129 static int check_activity_log_stripe_size(struct drbd_device *device,
3130                 struct meta_data_on_disk *on_disk,
3131                 struct drbd_md *in_core)
3132 {
3133         u32 al_stripes = be32_to_cpu(on_disk->al_stripes);
3134         u32 al_stripe_size_4k = be32_to_cpu(on_disk->al_stripe_size_4k);
3135         u64 al_size_4k;
3136
3137         /* both not set: default to old fixed size activity log */
3138         if (al_stripes == 0 && al_stripe_size_4k == 0) {
3139                 al_stripes = 1;
3140                 al_stripe_size_4k = MD_32kB_SECT/8;
3141         }
3142
3143         /* some paranoia plausibility checks */
3144
3145         /* we need both values to be set */
3146         if (al_stripes == 0 || al_stripe_size_4k == 0)
3147                 goto err;
3148
3149         al_size_4k = (u64)al_stripes * al_stripe_size_4k;
3150
3151         /* Upper limit of activity log area, to avoid potential overflow
3152          * problems in al_tr_number_to_on_disk_sector(). As right now, more
3153          * than 72 * 4k blocks total only increases the amount of history,
3154          * limiting this arbitrarily to 16 GB is not a real limitation ;-)  */
3155         if (al_size_4k > (16 * 1024 * 1024/4))
3156                 goto err;
3157
3158         /* Lower limit: we need at least 8 transaction slots (32kB)
3159          * to not break existing setups */
3160         if (al_size_4k < MD_32kB_SECT/8)
3161                 goto err;
3162
3163         in_core->al_stripe_size_4k = al_stripe_size_4k;
3164         in_core->al_stripes = al_stripes;
3165         in_core->al_size_4k = al_size_4k;
3166
3167         return 0;
3168 err:
3169         drbd_err(device, "invalid activity log striping: al_stripes=%u, al_stripe_size_4k=%u\n",
3170                         al_stripes, al_stripe_size_4k);
3171         return -EINVAL;
3172 }
3173
3174 static int check_offsets_and_sizes(struct drbd_device *device, struct drbd_backing_dev *bdev)
3175 {
3176         sector_t capacity = drbd_get_capacity(bdev->md_bdev);
3177         struct drbd_md *in_core = &bdev->md;
3178         s32 on_disk_al_sect;
3179         s32 on_disk_bm_sect;
3180
3181         /* The on-disk size of the activity log, calculated from offsets, and
3182          * the size of the activity log calculated from the stripe settings,
3183          * should match.
3184          * Though we could relax this a bit: it is ok, if the striped activity log
3185          * fits in the available on-disk activity log size.
3186          * Right now, that would break how resize is implemented.
3187          * TODO: make drbd_determine_dev_size() (and the drbdmeta tool) aware
3188          * of possible unused padding space in the on disk layout. */
3189         if (in_core->al_offset < 0) {
3190                 if (in_core->bm_offset > in_core->al_offset)
3191                         goto err;
3192                 on_disk_al_sect = -in_core->al_offset;
3193                 on_disk_bm_sect = in_core->al_offset - in_core->bm_offset;
3194         } else {
3195                 if (in_core->al_offset != MD_4kB_SECT)
3196                         goto err;
3197                 if (in_core->bm_offset < in_core->al_offset + in_core->al_size_4k * MD_4kB_SECT)
3198                         goto err;
3199
3200                 on_disk_al_sect = in_core->bm_offset - MD_4kB_SECT;
3201                 on_disk_bm_sect = in_core->md_size_sect - in_core->bm_offset;
3202         }
3203
3204         /* old fixed size meta data is exactly that: fixed. */
3205         if (in_core->meta_dev_idx >= 0) {
3206                 if (in_core->md_size_sect != MD_128MB_SECT
3207                 ||  in_core->al_offset != MD_4kB_SECT
3208                 ||  in_core->bm_offset != MD_4kB_SECT + MD_32kB_SECT
3209                 ||  in_core->al_stripes != 1
3210                 ||  in_core->al_stripe_size_4k != MD_32kB_SECT/8)
3211                         goto err;
3212         }
3213
3214         if (capacity < in_core->md_size_sect)
3215                 goto err;
3216         if (capacity - in_core->md_size_sect < drbd_md_first_sector(bdev))
3217                 goto err;
3218
3219         /* should be aligned, and at least 32k */
3220         if ((on_disk_al_sect & 7) || (on_disk_al_sect < MD_32kB_SECT))
3221                 goto err;
3222
3223         /* should fit (for now: exactly) into the available on-disk space;
3224          * overflow prevention is in check_activity_log_stripe_size() above. */
3225         if (on_disk_al_sect != in_core->al_size_4k * MD_4kB_SECT)
3226                 goto err;
3227
3228         /* again, should be aligned */
3229         if (in_core->bm_offset & 7)
3230                 goto err;
3231
3232         /* FIXME check for device grow with flex external meta data? */
3233
3234         /* can the available bitmap space cover the last agreed device size? */
3235         if (on_disk_bm_sect < (in_core->la_size_sect+7)/MD_4kB_SECT/8/512)
3236                 goto err;
3237
3238         return 0;
3239
3240 err:
3241         drbd_err(device, "meta data offsets don't make sense: idx=%d "
3242                         "al_s=%u, al_sz4k=%u, al_offset=%d, bm_offset=%d, "
3243                         "md_size_sect=%u, la_size=%llu, md_capacity=%llu\n",
3244                         in_core->meta_dev_idx,
3245                         in_core->al_stripes, in_core->al_stripe_size_4k,
3246                         in_core->al_offset, in_core->bm_offset, in_core->md_size_sect,
3247                         (unsigned long long)in_core->la_size_sect,
3248                         (unsigned long long)capacity);
3249
3250         return -EINVAL;
3251 }
3252
3253
3254 /**
3255  * drbd_md_read() - Reads in the meta data super block
3256  * @device:     DRBD device.
3257  * @bdev:       Device from which the meta data should be read in.
3258  *
3259  * Return NO_ERROR on success, and an enum drbd_ret_code in case
3260  * something goes wrong.
3261  *
3262  * Called exactly once during drbd_adm_attach(), while still being D_DISKLESS,
3263  * even before @bdev is assigned to @device->ldev.
3264  */
3265 int drbd_md_read(struct drbd_device *device, struct drbd_backing_dev *bdev)
3266 {
3267         struct meta_data_on_disk *buffer;
3268         u32 magic, flags;
3269         int i, rv = NO_ERROR;
3270
3271         if (device->state.disk != D_DISKLESS)
3272                 return ERR_DISK_CONFIGURED;
3273
3274         buffer = drbd_md_get_buffer(device, __func__);
3275         if (!buffer)
3276                 return ERR_NOMEM;
3277
3278         /* First, figure out where our meta data superblock is located,
3279          * and read it. */
3280         bdev->md.meta_dev_idx = bdev->disk_conf->meta_dev_idx;
3281         bdev->md.md_offset = drbd_md_ss(bdev);
3282
3283         if (drbd_md_sync_page_io(device, bdev, bdev->md.md_offset, READ)) {
3284                 /* NOTE: can't do normal error processing here as this is
3285                    called BEFORE disk is attached */
3286                 drbd_err(device, "Error while reading metadata.\n");
3287                 rv = ERR_IO_MD_DISK;
3288                 goto err;
3289         }
3290
3291         magic = be32_to_cpu(buffer->magic);
3292         flags = be32_to_cpu(buffer->flags);
3293         if (magic == DRBD_MD_MAGIC_84_UNCLEAN ||
3294             (magic == DRBD_MD_MAGIC_08 && !(flags & MDF_AL_CLEAN))) {
3295                         /* btw: that's Activity Log clean, not "all" clean. */
3296                 drbd_err(device, "Found unclean meta data. Did you \"drbdadm apply-al\"?\n");
3297                 rv = ERR_MD_UNCLEAN;
3298                 goto err;
3299         }
3300
3301         rv = ERR_MD_INVALID;
3302         if (magic != DRBD_MD_MAGIC_08) {
3303                 if (magic == DRBD_MD_MAGIC_07)
3304                         drbd_err(device, "Found old (0.7) meta data magic. Did you \"drbdadm create-md\"?\n");
3305                 else
3306                         drbd_err(device, "Meta data magic not found. Did you \"drbdadm create-md\"?\n");
3307                 goto err;
3308         }
3309
3310         if (be32_to_cpu(buffer->bm_bytes_per_bit) != BM_BLOCK_SIZE) {
3311                 drbd_err(device, "unexpected bm_bytes_per_bit: %u (expected %u)\n",
3312                     be32_to_cpu(buffer->bm_bytes_per_bit), BM_BLOCK_SIZE);
3313                 goto err;
3314         }
3315
3316
3317         /* convert to in_core endian */
3318         bdev->md.la_size_sect = be64_to_cpu(buffer->la_size_sect);
3319         for (i = UI_CURRENT; i < UI_SIZE; i++)
3320                 bdev->md.uuid[i] = be64_to_cpu(buffer->uuid[i]);
3321         bdev->md.flags = be32_to_cpu(buffer->flags);
3322         bdev->md.device_uuid = be64_to_cpu(buffer->device_uuid);
3323
3324         bdev->md.md_size_sect = be32_to_cpu(buffer->md_size_sect);
3325         bdev->md.al_offset = be32_to_cpu(buffer->al_offset);
3326         bdev->md.bm_offset = be32_to_cpu(buffer->bm_offset);
3327
3328         if (check_activity_log_stripe_size(device, buffer, &bdev->md))
3329                 goto err;
3330         if (check_offsets_and_sizes(device, bdev))
3331                 goto err;
3332
3333         if (be32_to_cpu(buffer->bm_offset) != bdev->md.bm_offset) {
3334                 drbd_err(device, "unexpected bm_offset: %d (expected %d)\n",
3335                     be32_to_cpu(buffer->bm_offset), bdev->md.bm_offset);
3336                 goto err;
3337         }
3338         if (be32_to_cpu(buffer->md_size_sect) != bdev->md.md_size_sect) {
3339                 drbd_err(device, "unexpected md_size: %u (expected %u)\n",
3340                     be32_to_cpu(buffer->md_size_sect), bdev->md.md_size_sect);
3341                 goto err;
3342         }
3343
3344         rv = NO_ERROR;
3345
3346         spin_lock_irq(&device->resource->req_lock);
3347         if (device->state.conn < C_CONNECTED) {
3348                 unsigned int peer;
3349                 peer = be32_to_cpu(buffer->la_peer_max_bio_size);
3350                 peer = max(peer, DRBD_MAX_BIO_SIZE_SAFE);
3351                 device->peer_max_bio_size = peer;
3352         }
3353         spin_unlock_irq(&device->resource->req_lock);
3354
3355  err:
3356         drbd_md_put_buffer(device);
3357
3358         return rv;
3359 }
3360
3361 /**
3362  * drbd_md_mark_dirty() - Mark meta data super block as dirty
3363  * @device:     DRBD device.
3364  *
3365  * Call this function if you change anything that should be written to
3366  * the meta-data super block. This function sets MD_DIRTY, and starts a
3367  * timer that ensures that within five seconds you have to call drbd_md_sync().
3368  */
3369 #ifdef DEBUG
3370 void drbd_md_mark_dirty_(struct drbd_device *device, unsigned int line, const char *func)
3371 {
3372         if (!test_and_set_bit(MD_DIRTY, &device->flags)) {
3373                 mod_timer(&device->md_sync_timer, jiffies + HZ);
3374                 device->last_md_mark_dirty.line = line;
3375                 device->last_md_mark_dirty.func = func;
3376         }
3377 }
3378 #else
3379 void drbd_md_mark_dirty(struct drbd_device *device)
3380 {
3381         if (!test_and_set_bit(MD_DIRTY, &device->flags))
3382                 mod_timer(&device->md_sync_timer, jiffies + 5*HZ);
3383 }
3384 #endif
3385
3386 void drbd_uuid_move_history(struct drbd_device *device) __must_hold(local)
3387 {
3388         int i;
3389
3390         for (i = UI_HISTORY_START; i < UI_HISTORY_END; i++)
3391                 device->ldev->md.uuid[i+1] = device->ldev->md.uuid[i];
3392 }
3393
3394 void __drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local)
3395 {
3396         if (idx == UI_CURRENT) {
3397                 if (device->state.role == R_PRIMARY)
3398                         val |= 1;
3399                 else
3400                         val &= ~((u64)1);
3401
3402                 drbd_set_ed_uuid(device, val);
3403         }
3404
3405         device->ldev->md.uuid[idx] = val;
3406         drbd_md_mark_dirty(device);
3407 }
3408
3409 void _drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local)
3410 {
3411         unsigned long flags;
3412         spin_lock_irqsave(&device->ldev->md.uuid_lock, flags);
3413         __drbd_uuid_set(device, idx, val);
3414         spin_unlock_irqrestore(&device->ldev->md.uuid_lock, flags);
3415 }
3416
3417 void drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local)
3418 {
3419         unsigned long flags;
3420         spin_lock_irqsave(&device->ldev->md.uuid_lock, flags);
3421         if (device->ldev->md.uuid[idx]) {
3422                 drbd_uuid_move_history(device);
3423                 device->ldev->md.uuid[UI_HISTORY_START] = device->ldev->md.uuid[idx];
3424         }
3425         __drbd_uuid_set(device, idx, val);
3426         spin_unlock_irqrestore(&device->ldev->md.uuid_lock, flags);
3427 }
3428
3429 /**
3430  * drbd_uuid_new_current() - Creates a new current UUID
3431  * @device:     DRBD device.
3432  *
3433  * Creates a new current UUID, and rotates the old current UUID into
3434  * the bitmap slot. Causes an incremental resync upon next connect.
3435  */
3436 void drbd_uuid_new_current(struct drbd_device *device) __must_hold(local)
3437 {
3438         u64 val;
3439         unsigned long long bm_uuid;
3440
3441         get_random_bytes(&val, sizeof(u64));
3442
3443         spin_lock_irq(&device->ldev->md.uuid_lock);
3444         bm_uuid = device->ldev->md.uuid[UI_BITMAP];
3445
3446         if (bm_uuid)
3447                 drbd_warn(device, "bm UUID was already set: %llX\n", bm_uuid);
3448
3449         device->ldev->md.uuid[UI_BITMAP] = device->ldev->md.uuid[UI_CURRENT];
3450         __drbd_uuid_set(device, UI_CURRENT, val);
3451         spin_unlock_irq(&device->ldev->md.uuid_lock);
3452
3453         drbd_print_uuids(device, "new current UUID");
3454         /* get it to stable storage _now_ */
3455         drbd_md_sync(device);
3456 }
3457
3458 void drbd_uuid_set_bm(struct drbd_device *device, u64 val) __must_hold(local)
3459 {
3460         unsigned long flags;
3461         if (device->ldev->md.uuid[UI_BITMAP] == 0 && val == 0)
3462                 return;
3463
3464         spin_lock_irqsave(&device->ldev->md.uuid_lock, flags);
3465         if (val == 0) {
3466                 drbd_uuid_move_history(device);
3467                 device->ldev->md.uuid[UI_HISTORY_START] = device->ldev->md.uuid[UI_BITMAP];
3468                 device->ldev->md.uuid[UI_BITMAP] = 0;
3469         } else {
3470                 unsigned long long bm_uuid = device->ldev->md.uuid[UI_BITMAP];
3471                 if (bm_uuid)
3472                         drbd_warn(device, "bm UUID was already set: %llX\n", bm_uuid);
3473
3474                 device->ldev->md.uuid[UI_BITMAP] = val & ~((u64)1);
3475         }
3476         spin_unlock_irqrestore(&device->ldev->md.uuid_lock, flags);
3477
3478         drbd_md_mark_dirty(device);
3479 }
3480
3481 /**
3482  * drbd_bmio_set_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
3483  * @device:     DRBD device.
3484  *
3485  * Sets all bits in the bitmap and writes the whole bitmap to stable storage.
3486  */
3487 int drbd_bmio_set_n_write(struct drbd_device *device) __must_hold(local)
3488 {
3489         int rv = -EIO;
3490
3491         drbd_md_set_flag(device, MDF_FULL_SYNC);
3492         drbd_md_sync(device);
3493         drbd_bm_set_all(device);
3494
3495         rv = drbd_bm_write(device);
3496
3497         if (!rv) {
3498                 drbd_md_clear_flag(device, MDF_FULL_SYNC);
3499                 drbd_md_sync(device);
3500         }
3501
3502         return rv;
3503 }
3504
3505 /**
3506  * drbd_bmio_clear_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
3507  * @device:     DRBD device.
3508  *
3509  * Clears all bits in the bitmap and writes the whole bitmap to stable storage.
3510  */
3511 int drbd_bmio_clear_n_write(struct drbd_device *device) __must_hold(local)
3512 {
3513         drbd_resume_al(device);
3514         drbd_bm_clear_all(device);
3515         return drbd_bm_write(device);
3516 }
3517
3518 static int w_bitmap_io(struct drbd_work *w, int unused)
3519 {
3520         struct drbd_device *device =
3521                 container_of(w, struct drbd_device, bm_io_work.w);
3522         struct bm_io_work *work = &device->bm_io_work;
3523         int rv = -EIO;
3524
3525         D_ASSERT(device, atomic_read(&device->ap_bio_cnt) == 0);
3526
3527         if (get_ldev(device)) {
3528                 drbd_bm_lock(device, work->why, work->flags);
3529                 rv = work->io_fn(device);
3530                 drbd_bm_unlock(device);
3531                 put_ldev(device);
3532         }
3533
3534         clear_bit_unlock(BITMAP_IO, &device->flags);
3535         wake_up(&device->misc_wait);
3536
3537         if (work->done)
3538                 work->done(device, rv);
3539
3540         clear_bit(BITMAP_IO_QUEUED, &device->flags);
3541         work->why = NULL;
3542         work->flags = 0;
3543
3544         return 0;
3545 }
3546
3547 /**
3548  * drbd_queue_bitmap_io() - Queues an IO operation on the whole bitmap
3549  * @device:     DRBD device.
3550  * @io_fn:      IO callback to be called when bitmap IO is possible
3551  * @done:       callback to be called after the bitmap IO was performed
3552  * @why:        Descriptive text of the reason for doing the IO
3553  *
3554  * While IO on the bitmap happens we freeze application IO thus we ensure
3555  * that drbd_set_out_of_sync() can not be called. This function MAY ONLY be
3556  * called from worker context. It MUST NOT be used while a previous such
3557  * work is still pending!
3558  *
3559  * Its worker function encloses the call of io_fn() by get_ldev() and
3560  * put_ldev().
3561  */
3562 void drbd_queue_bitmap_io(struct drbd_device *device,
3563                           int (*io_fn)(struct drbd_device *),
3564                           void (*done)(struct drbd_device *, int),
3565                           char *why, enum bm_flag flags)
3566 {
3567         D_ASSERT(device, current == first_peer_device(device)->connection->worker.task);
3568
3569         D_ASSERT(device, !test_bit(BITMAP_IO_QUEUED, &device->flags));
3570         D_ASSERT(device, !test_bit(BITMAP_IO, &device->flags));
3571         D_ASSERT(device, list_empty(&device->bm_io_work.w.list));
3572         if (device->bm_io_work.why)
3573                 drbd_err(device, "FIXME going to queue '%s' but '%s' still pending?\n",
3574                         why, device->bm_io_work.why);
3575
3576         device->bm_io_work.io_fn = io_fn;
3577         device->bm_io_work.done = done;
3578         device->bm_io_work.why = why;
3579         device->bm_io_work.flags = flags;
3580
3581         spin_lock_irq(&device->resource->req_lock);
3582         set_bit(BITMAP_IO, &device->flags);
3583         if (atomic_read(&device->ap_bio_cnt) == 0) {
3584                 if (!test_and_set_bit(BITMAP_IO_QUEUED, &device->flags))
3585                         drbd_queue_work(&first_peer_device(device)->connection->sender_work,
3586                                         &device->bm_io_work.w);
3587         }
3588         spin_unlock_irq(&device->resource->req_lock);
3589 }
3590
3591 /**
3592  * drbd_bitmap_io() -  Does an IO operation on the whole bitmap
3593  * @device:     DRBD device.
3594  * @io_fn:      IO callback to be called when bitmap IO is possible
3595  * @why:        Descriptive text of the reason for doing the IO
3596  *
3597  * freezes application IO while that the actual IO operations runs. This
3598  * functions MAY NOT be called from worker context.
3599  */
3600 int drbd_bitmap_io(struct drbd_device *device, int (*io_fn)(struct drbd_device *),
3601                 char *why, enum bm_flag flags)
3602 {
3603         int rv;
3604
3605         D_ASSERT(device, current != first_peer_device(device)->connection->worker.task);
3606
3607         if ((flags & BM_LOCKED_SET_ALLOWED) == 0)
3608                 drbd_suspend_io(device);
3609
3610         drbd_bm_lock(device, why, flags);
3611         rv = io_fn(device);
3612         drbd_bm_unlock(device);
3613
3614         if ((flags & BM_LOCKED_SET_ALLOWED) == 0)
3615                 drbd_resume_io(device);
3616
3617         return rv;
3618 }
3619
3620 void drbd_md_set_flag(struct drbd_device *device, int flag) __must_hold(local)
3621 {
3622         if ((device->ldev->md.flags & flag) != flag) {
3623                 drbd_md_mark_dirty(device);
3624                 device->ldev->md.flags |= flag;
3625         }
3626 }
3627
3628 void drbd_md_clear_flag(struct drbd_device *device, int flag) __must_hold(local)
3629 {
3630         if ((device->ldev->md.flags & flag) != 0) {
3631                 drbd_md_mark_dirty(device);
3632                 device->ldev->md.flags &= ~flag;
3633         }
3634 }
3635 int drbd_md_test_flag(struct drbd_backing_dev *bdev, int flag)
3636 {
3637         return (bdev->md.flags & flag) != 0;
3638 }
3639
3640 static void md_sync_timer_fn(unsigned long data)
3641 {
3642         struct drbd_device *device = (struct drbd_device *) data;
3643         drbd_device_post_work(device, MD_SYNC);
3644 }
3645
3646 const char *cmdname(enum drbd_packet cmd)
3647 {
3648         /* THINK may need to become several global tables
3649          * when we want to support more than
3650          * one PRO_VERSION */
3651         static const char *cmdnames[] = {
3652                 [P_DATA]                = "Data",
3653                 [P_DATA_REPLY]          = "DataReply",
3654                 [P_RS_DATA_REPLY]       = "RSDataReply",
3655                 [P_BARRIER]             = "Barrier",
3656                 [P_BITMAP]              = "ReportBitMap",
3657                 [P_BECOME_SYNC_TARGET]  = "BecomeSyncTarget",
3658                 [P_BECOME_SYNC_SOURCE]  = "BecomeSyncSource",
3659                 [P_UNPLUG_REMOTE]       = "UnplugRemote",
3660                 [P_DATA_REQUEST]        = "DataRequest",
3661                 [P_RS_DATA_REQUEST]     = "RSDataRequest",
3662                 [P_SYNC_PARAM]          = "SyncParam",
3663                 [P_SYNC_PARAM89]        = "SyncParam89",
3664                 [P_PROTOCOL]            = "ReportProtocol",
3665                 [P_UUIDS]               = "ReportUUIDs",
3666                 [P_SIZES]               = "ReportSizes",
3667                 [P_STATE]               = "ReportState",
3668                 [P_SYNC_UUID]           = "ReportSyncUUID",
3669                 [P_AUTH_CHALLENGE]      = "AuthChallenge",
3670                 [P_AUTH_RESPONSE]       = "AuthResponse",
3671                 [P_PING]                = "Ping",
3672                 [P_PING_ACK]            = "PingAck",
3673                 [P_RECV_ACK]            = "RecvAck",
3674                 [P_WRITE_ACK]           = "WriteAck",
3675                 [P_RS_WRITE_ACK]        = "RSWriteAck",
3676                 [P_SUPERSEDED]          = "Superseded",
3677                 [P_NEG_ACK]             = "NegAck",
3678                 [P_NEG_DREPLY]          = "NegDReply",
3679                 [P_NEG_RS_DREPLY]       = "NegRSDReply",
3680                 [P_BARRIER_ACK]         = "BarrierAck",
3681                 [P_STATE_CHG_REQ]       = "StateChgRequest",
3682                 [P_STATE_CHG_REPLY]     = "StateChgReply",
3683                 [P_OV_REQUEST]          = "OVRequest",
3684                 [P_OV_REPLY]            = "OVReply",
3685                 [P_OV_RESULT]           = "OVResult",
3686                 [P_CSUM_RS_REQUEST]     = "CsumRSRequest",
3687                 [P_RS_IS_IN_SYNC]       = "CsumRSIsInSync",
3688                 [P_COMPRESSED_BITMAP]   = "CBitmap",
3689                 [P_DELAY_PROBE]         = "DelayProbe",
3690                 [P_OUT_OF_SYNC]         = "OutOfSync",
3691                 [P_RETRY_WRITE]         = "RetryWrite",
3692                 [P_RS_CANCEL]           = "RSCancel",
3693                 [P_CONN_ST_CHG_REQ]     = "conn_st_chg_req",
3694                 [P_CONN_ST_CHG_REPLY]   = "conn_st_chg_reply",
3695                 [P_RETRY_WRITE]         = "retry_write",
3696                 [P_PROTOCOL_UPDATE]     = "protocol_update",
3697
3698                 /* enum drbd_packet, but not commands - obsoleted flags:
3699                  *      P_MAY_IGNORE
3700                  *      P_MAX_OPT_CMD
3701                  */
3702         };
3703
3704         /* too big for the array: 0xfffX */
3705         if (cmd == P_INITIAL_META)
3706                 return "InitialMeta";
3707         if (cmd == P_INITIAL_DATA)
3708                 return "InitialData";
3709         if (cmd == P_CONNECTION_FEATURES)
3710                 return "ConnectionFeatures";
3711         if (cmd >= ARRAY_SIZE(cmdnames))
3712                 return "Unknown";
3713         return cmdnames[cmd];
3714 }
3715
3716 /**
3717  * drbd_wait_misc  -  wait for a request to make progress
3718  * @device:     device associated with the request
3719  * @i:          the struct drbd_interval embedded in struct drbd_request or
3720  *              struct drbd_peer_request
3721  */
3722 int drbd_wait_misc(struct drbd_device *device, struct drbd_interval *i)
3723 {
3724         struct net_conf *nc;
3725         DEFINE_WAIT(wait);
3726         long timeout;
3727
3728         rcu_read_lock();
3729         nc = rcu_dereference(first_peer_device(device)->connection->net_conf);
3730         if (!nc) {
3731                 rcu_read_unlock();
3732                 return -ETIMEDOUT;
3733         }
3734         timeout = nc->ko_count ? nc->timeout * HZ / 10 * nc->ko_count : MAX_SCHEDULE_TIMEOUT;
3735         rcu_read_unlock();
3736
3737         /* Indicate to wake up device->misc_wait on progress.  */
3738         i->waiting = true;
3739         prepare_to_wait(&device->misc_wait, &wait, TASK_INTERRUPTIBLE);
3740         spin_unlock_irq(&device->resource->req_lock);
3741         timeout = schedule_timeout(timeout);
3742         finish_wait(&device->misc_wait, &wait);
3743         spin_lock_irq(&device->resource->req_lock);
3744         if (!timeout || device->state.conn < C_CONNECTED)
3745                 return -ETIMEDOUT;
3746         if (signal_pending(current))
3747                 return -ERESTARTSYS;
3748         return 0;
3749 }
3750
3751 #ifdef CONFIG_DRBD_FAULT_INJECTION
3752 /* Fault insertion support including random number generator shamelessly
3753  * stolen from kernel/rcutorture.c */
3754 struct fault_random_state {
3755         unsigned long state;
3756         unsigned long count;
3757 };
3758
3759 #define FAULT_RANDOM_MULT 39916801  /* prime */
3760 #define FAULT_RANDOM_ADD        479001701 /* prime */
3761 #define FAULT_RANDOM_REFRESH 10000
3762
3763 /*
3764  * Crude but fast random-number generator.  Uses a linear congruential
3765  * generator, with occasional help from get_random_bytes().
3766  */
3767 static unsigned long
3768 _drbd_fault_random(struct fault_random_state *rsp)
3769 {
3770         long refresh;
3771
3772         if (!rsp->count--) {
3773                 get_random_bytes(&refresh, sizeof(refresh));
3774                 rsp->state += refresh;
3775                 rsp->count = FAULT_RANDOM_REFRESH;
3776         }
3777         rsp->state = rsp->state * FAULT_RANDOM_MULT + FAULT_RANDOM_ADD;
3778         return swahw32(rsp->state);
3779 }
3780
3781 static char *
3782 _drbd_fault_str(unsigned int type) {
3783         static char *_faults[] = {
3784                 [DRBD_FAULT_MD_WR] = "Meta-data write",
3785                 [DRBD_FAULT_MD_RD] = "Meta-data read",
3786                 [DRBD_FAULT_RS_WR] = "Resync write",
3787                 [DRBD_FAULT_RS_RD] = "Resync read",
3788                 [DRBD_FAULT_DT_WR] = "Data write",
3789                 [DRBD_FAULT_DT_RD] = "Data read",
3790                 [DRBD_FAULT_DT_RA] = "Data read ahead",
3791                 [DRBD_FAULT_BM_ALLOC] = "BM allocation",
3792                 [DRBD_FAULT_AL_EE] = "EE allocation",
3793                 [DRBD_FAULT_RECEIVE] = "receive data corruption",
3794         };
3795
3796         return (type < DRBD_FAULT_MAX) ? _faults[type] : "**Unknown**";
3797 }
3798
3799 unsigned int
3800 _drbd_insert_fault(struct drbd_device *device, unsigned int type)
3801 {
3802         static struct fault_random_state rrs = {0, 0};
3803
3804         unsigned int ret = (
3805                 (fault_devs == 0 ||
3806                         ((1 << device_to_minor(device)) & fault_devs) != 0) &&
3807                 (((_drbd_fault_random(&rrs) % 100) + 1) <= fault_rate));
3808
3809         if (ret) {
3810                 fault_count++;
3811
3812                 if (__ratelimit(&drbd_ratelimit_state))
3813                         drbd_warn(device, "***Simulating %s failure\n",
3814                                 _drbd_fault_str(type));
3815         }
3816
3817         return ret;
3818 }
3819 #endif
3820
3821 const char *drbd_buildtag(void)
3822 {
3823         /* DRBD built from external sources has here a reference to the
3824            git hash of the source code. */
3825
3826         static char buildtag[38] = "\0uilt-in";
3827
3828         if (buildtag[0] == 0) {
3829 #ifdef MODULE
3830                 sprintf(buildtag, "srcversion: %-24s", THIS_MODULE->srcversion);
3831 #else
3832                 buildtag[0] = 'b';
3833 #endif
3834         }
3835
3836         return buildtag;
3837 }
3838
3839 module_init(drbd_init)
3840 module_exit(drbd_cleanup)
3841
3842 EXPORT_SYMBOL(drbd_conn_str);
3843 EXPORT_SYMBOL(drbd_role_str);
3844 EXPORT_SYMBOL(drbd_disk_str);
3845 EXPORT_SYMBOL(drbd_set_st_err_str);