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 <linux/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 struct mutex resources_mutex;
 121
 122 struct kmem_cache *drbd_request_cache;
 123 struct kmem_cache *drbd_ee_cache;       /* peer requests */
 124 struct kmem_cache *drbd_bm_ext_cache;   /* bitmap extents */
 125 struct kmem_cache *drbd_al_ext_cache;   /* activity log extents */
 126 mempool_t *drbd_request_mempool;
 127 mempool_t *drbd_ee_mempool;
 128 mempool_t *drbd_md_io_page_pool;
 129 struct bio_set *drbd_md_io_bio_set;
 130
 131 /* I do not use a standard mempool, because:
 132    1) I want to hand out the pre-allocated objects first.
 133    2) I want to be able to interrupt sleeping allocation with a signal.
 134    Note: This is a single linked list, the next pointer is the private
 135          member of struct page.
 136  */
 137 struct page *drbd_pp_pool;
 138 spinlock_t   drbd_pp_lock;
 139 int          drbd_pp_vacant;
 140 wait_queue_head_t drbd_pp_wait;
 141
 142 DEFINE_RATELIMIT_STATE(drbd_ratelimit_state, 5 * HZ, 5);
 143
 144 static const struct block_device_operations drbd_ops = {
 145         .owner =   THIS_MODULE,
 146         .open =    drbd_open,
 147         .release = drbd_release,
 148 };
 149
 150 struct bio *bio_alloc_drbd(gfp_t gfp_mask)
 151 {
 152         struct bio *bio;
 153
 154         if (!drbd_md_io_bio_set)
 155                 return bio_alloc(gfp_mask, 1);
 156
 157         bio = bio_alloc_bioset(gfp_mask, 1, drbd_md_io_bio_set);
 158         if (!bio)
 159                 return NULL;
 160         return bio;
 161 }
 162
 163 #ifdef __CHECKER__
 164 /* When checking with sparse, and this is an inline function, sparse will
 165    give tons of false positives. When this is a real functions sparse works.
 166  */
 167 int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins)
 168 {
 169         int io_allowed;
 170
 171         atomic_inc(&device->local_cnt);
 172         io_allowed = (device->state.disk >= mins);
 173         if (!io_allowed) {
 174                 if (atomic_dec_and_test(&device->local_cnt))
 175                         wake_up(&device->misc_wait);
 176         }
 177         return io_allowed;
 178 }
 179
 180 #endif
 181
 182 /**
 183  * tl_release() - mark as BARRIER_ACKED all requests in the corresponding transfer log epoch
 184  * @connection: DRBD connection.
 185  * @barrier_nr: Expected identifier of the DRBD write barrier packet.
 186  * @set_size:   Expected number of requests before that barrier.
 187  *
 188  * In case the passed barrier_nr or set_size does not match the oldest
 189  * epoch of not yet barrier-acked requests, this function will cause a
 190  * termination of the connection.
 191  */
 192 void tl_release(struct drbd_connection *connection, unsigned int barrier_nr,
 193                 unsigned int set_size)
 194 {
 195         struct drbd_request *r;
 196         struct drbd_request *req = NULL;
 197         int expect_epoch = 0;
 198         int expect_size = 0;
 199
 200         spin_lock_irq(&connection->resource->req_lock);
 201
 202         /* find oldest not yet barrier-acked write request,
 203          * count writes in its epoch. */
 204         list_for_each_entry(r, &connection->transfer_log, tl_requests) {
 205                 const unsigned s = r->rq_state;
 206                 if (!req) {
 207                         if (!(s & RQ_WRITE))
 208                                 continue;
 209                         if (!(s & RQ_NET_MASK))
 210                                 continue;
 211                         if (s & RQ_NET_DONE)
 212                                 continue;
 213                         req = r;
 214                         expect_epoch = req->epoch;
 215                         expect_size ++;
 216                 } else {
 217                         if (r->epoch != expect_epoch)
 218                                 break;
 219                         if (!(s & RQ_WRITE))
 220                                 continue;
 221                         /* if (s & RQ_DONE): not expected */
 222                         /* if (!(s & RQ_NET_MASK)): not expected */
 223                         expect_size++;
 224                 }
 225         }
 226
 227         /* first some paranoia code */
 228         if (req == NULL) {
 229                 drbd_err(connection, "BAD! BarrierAck #%u received, but no epoch in tl!?\n",
 230                          barrier_nr);
 231                 goto bail;
 232         }
 233         if (expect_epoch != barrier_nr) {
 234                 drbd_err(connection, "BAD! BarrierAck #%u received, expected #%u!\n",
 235                          barrier_nr, expect_epoch);
 236                 goto bail;
 237         }
 238
 239         if (expect_size != set_size) {
 240                 drbd_err(connection, "BAD! BarrierAck #%u received with n_writes=%u, expected n_writes=%u!\n",
 241                          barrier_nr, set_size, expect_size);
 242                 goto bail;
 243         }
 244
 245         /* Clean up list of requests processed during current epoch. */
 246         /* this extra list walk restart is paranoia,
 247          * to catch requests being barrier-acked "unexpectedly".
 248          * It usually should find the same req again, or some READ preceding it. */
 249         list_for_each_entry(req, &connection->transfer_log, tl_requests)
 250                 if (req->epoch == expect_epoch)
 251                         break;
 252         list_for_each_entry_safe_from(req, r, &connection->transfer_log, tl_requests) {
 253                 if (req->epoch != expect_epoch)
 254                         break;
 255                 _req_mod(req, BARRIER_ACKED);
 256         }
 257         spin_unlock_irq(&connection->resource->req_lock);
 258
 259         return;
 260
 261 bail:
 262         spin_unlock_irq(&connection->resource->req_lock);
 263         conn_request_state(connection, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
 264 }
 265
 266
 267 /**
 268  * _tl_restart() - Walks the transfer log, and applies an action to all requests
 269  * @connection: DRBD connection to operate on.
 270  * @what:       The action/event to perform with all request objects
 271  *
 272  * @what might be one of CONNECTION_LOST_WHILE_PENDING, RESEND, FAIL_FROZEN_DISK_IO,
 273  * RESTART_FROZEN_DISK_IO.
 274  */
 275 /* must hold resource->req_lock */
 276 void _tl_restart(struct drbd_connection *connection, enum drbd_req_event what)
 277 {
 278         struct drbd_request *req, *r;
 279
 280         list_for_each_entry_safe(req, r, &connection->transfer_log, tl_requests)
 281                 _req_mod(req, what);
 282 }
 283
 284 void tl_restart(struct drbd_connection *connection, enum drbd_req_event what)
 285 {
 286         spin_lock_irq(&connection->resource->req_lock);
 287         _tl_restart(connection, what);
 288         spin_unlock_irq(&connection->resource->req_lock);
 289 }
 290
 291 /**
 292  * tl_clear() - Clears all requests and &struct drbd_tl_epoch objects out of the TL
 293  * @device:     DRBD device.
 294  *
 295  * This is called after the connection to the peer was lost. The storage covered
 296  * by the requests on the transfer gets marked as our of sync. Called from the
 297  * receiver thread and the worker thread.
 298  */
 299 void tl_clear(struct drbd_connection *connection)
 300 {
 301         tl_restart(connection, CONNECTION_LOST_WHILE_PENDING);
 302 }
 303
 304 /**
 305  * tl_abort_disk_io() - Abort disk I/O for all requests for a certain device in the TL
 306  * @device:     DRBD device.
 307  */
 308 void tl_abort_disk_io(struct drbd_device *device)
 309 {
 310         struct drbd_connection *connection = first_peer_device(device)->connection;
 311         struct drbd_request *req, *r;
 312
 313         spin_lock_irq(&connection->resource->req_lock);
 314         list_for_each_entry_safe(req, r, &connection->transfer_log, tl_requests) {
 315                 if (!(req->rq_state & RQ_LOCAL_PENDING))
 316                         continue;
 317                 if (req->device != device)
 318                         continue;
 319                 _req_mod(req, ABORT_DISK_IO);
 320         }
 321         spin_unlock_irq(&connection->resource->req_lock);
 322 }
 323
 324 static int drbd_thread_setup(void *arg)
 325 {
 326         struct drbd_thread *thi = (struct drbd_thread *) arg;
 327         struct drbd_resource *resource = thi->resource;
 328         unsigned long flags;
 329         int retval;
 330
 331         snprintf(current->comm, sizeof(current->comm), "drbd_%c_%s",
 332                  thi->name[0],
 333                  resource->name);
 334
 335 restart:
 336         retval = thi->function(thi);
 337
 338         spin_lock_irqsave(&thi->t_lock, flags);
 339
 340         /* if the receiver has been "EXITING", the last thing it did
 341          * was set the conn state to "StandAlone",
 342          * if now a re-connect request comes in, conn state goes C_UNCONNECTED,
 343          * and receiver thread will be "started".
 344          * drbd_thread_start needs to set "RESTARTING" in that case.
 345          * t_state check and assignment needs to be within the same spinlock,
 346          * so either thread_start sees EXITING, and can remap to RESTARTING,
 347          * or thread_start see NONE, and can proceed as normal.
 348          */
 349
 350         if (thi->t_state == RESTARTING) {
 351                 drbd_info(resource, "Restarting %s thread\n", thi->name);
 352                 thi->t_state = RUNNING;
 353                 spin_unlock_irqrestore(&thi->t_lock, flags);
 354                 goto restart;
 355         }
 356
 357         thi->task = NULL;
 358         thi->t_state = NONE;
 359         smp_mb();
 360         complete_all(&thi->stop);
 361         spin_unlock_irqrestore(&thi->t_lock, flags);
 362
 363         drbd_info(resource, "Terminating %s\n", current->comm);
 364
 365         /* Release mod reference taken when thread was started */
 366
 367         if (thi->connection)
 368                 kref_put(&thi->connection->kref, drbd_destroy_connection);
 369         kref_put(&resource->kref, drbd_destroy_resource);
 370         module_put(THIS_MODULE);
 371         return retval;
 372 }
 373
 374 static void drbd_thread_init(struct drbd_resource *resource, struct drbd_thread *thi,
 375                              int (*func) (struct drbd_thread *), const char *name)
 376 {
 377         spin_lock_init(&thi->t_lock);
 378         thi->task    = NULL;
 379         thi->t_state = NONE;
 380         thi->function = func;
 381         thi->resource = resource;
 382         thi->connection = NULL;
 383         thi->name = name;
 384 }
 385
 386 int drbd_thread_start(struct drbd_thread *thi)
 387 {
 388         struct drbd_resource *resource = thi->resource;
 389         struct task_struct *nt;
 390         unsigned long flags;
 391
 392         /* is used from state engine doing drbd_thread_stop_nowait,
 393          * while holding the req lock irqsave */
 394         spin_lock_irqsave(&thi->t_lock, flags);
 395
 396         switch (thi->t_state) {
 397         case NONE:
 398                 drbd_info(resource, "Starting %s thread (from %s [%d])\n",
 399                          thi->name, current->comm, current->pid);
 400
 401                 /* Get ref on module for thread - this is released when thread exits */
 402                 if (!try_module_get(THIS_MODULE)) {
 403                         drbd_err(resource, "Failed to get module reference in drbd_thread_start\n");
 404                         spin_unlock_irqrestore(&thi->t_lock, flags);
 405                         return false;
 406                 }
 407
 408                 kref_get(&resource->kref);
 409                 if (thi->connection)
 410                         kref_get(&thi->connection->kref);
 411
 412                 init_completion(&thi->stop);
 413                 thi->reset_cpu_mask = 1;
 414                 thi->t_state = RUNNING;
 415                 spin_unlock_irqrestore(&thi->t_lock, flags);
 416                 flush_signals(current); /* otherw. may get -ERESTARTNOINTR */
 417
 418                 nt = kthread_create(drbd_thread_setup, (void *) thi,
 419                                     "drbd_%c_%s", thi->name[0], thi->resource->name);
 420
 421                 if (IS_ERR(nt)) {
 422                         drbd_err(resource, "Couldn't start thread\n");
 423
 424                         if (thi->connection)
 425                                 kref_put(&thi->connection->kref, drbd_destroy_connection);
 426                         kref_put(&resource->kref, drbd_destroy_resource);
 427                         module_put(THIS_MODULE);
 428                         return false;
 429                 }
 430                 spin_lock_irqsave(&thi->t_lock, flags);
 431                 thi->task = nt;
 432                 thi->t_state = RUNNING;
 433                 spin_unlock_irqrestore(&thi->t_lock, flags);
 434                 wake_up_process(nt);
 435                 break;
 436         case EXITING:
 437                 thi->t_state = RESTARTING;
 438                 drbd_info(resource, "Restarting %s thread (from %s [%d])\n",
 439                                 thi->name, current->comm, current->pid);
 440                 /* fall through */
 441         case RUNNING:
 442         case RESTARTING:
 443         default:
 444                 spin_unlock_irqrestore(&thi->t_lock, flags);
 445                 break;
 446         }
 447
 448         return true;
 449 }
 450
 451
 452 void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait)
 453 {
 454         unsigned long flags;
 455
 456         enum drbd_thread_state ns = restart ? RESTARTING : EXITING;
 457
 458         /* may be called from state engine, holding the req lock irqsave */
 459         spin_lock_irqsave(&thi->t_lock, flags);
 460
 461         if (thi->t_state == NONE) {
 462                 spin_unlock_irqrestore(&thi->t_lock, flags);
 463                 if (restart)
 464                         drbd_thread_start(thi);
 465                 return;
 466         }
 467
 468         if (thi->t_state != ns) {
 469                 if (thi->task == NULL) {
 470                         spin_unlock_irqrestore(&thi->t_lock, flags);
 471                         return;
 472                 }
 473
 474                 thi->t_state = ns;
 475                 smp_mb();
 476                 init_completion(&thi->stop);
 477                 if (thi->task != current)
 478                         force_sig(DRBD_SIGKILL, thi->task);
 479         }
 480
 481         spin_unlock_irqrestore(&thi->t_lock, flags);
 482
 483         if (wait)
 484                 wait_for_completion(&thi->stop);
 485 }
 486
 487 int conn_lowest_minor(struct drbd_connection *connection)
 488 {
 489         struct drbd_peer_device *peer_device;
 490         int vnr = 0, minor = -1;
 491
 492         rcu_read_lock();
 493         peer_device = idr_get_next(&connection->peer_devices, &vnr);
 494         if (peer_device)
 495                 minor = device_to_minor(peer_device->device);
 496         rcu_read_unlock();
 497
 498         return minor;
 499 }
 500
 501 #ifdef CONFIG_SMP
 502 /**
 503  * drbd_calc_cpu_mask() - Generate CPU masks, spread over all CPUs
 504  *
 505  * Forces all threads of a resource onto the same CPU. This is beneficial for
 506  * DRBD's performance. May be overwritten by user's configuration.
 507  */
 508 static void drbd_calc_cpu_mask(cpumask_var_t *cpu_mask)
 509 {
 510         unsigned int *resources_per_cpu, min_index = ~0;
 511
 512         resources_per_cpu = kzalloc(nr_cpu_ids * sizeof(*resources_per_cpu), GFP_KERNEL);
 513         if (resources_per_cpu) {
 514                 struct drbd_resource *resource;
 515                 unsigned int cpu, min = ~0;
 516
 517                 rcu_read_lock();
 518                 for_each_resource_rcu(resource, &drbd_resources) {
 519                         for_each_cpu(cpu, resource->cpu_mask)
 520                                 resources_per_cpu[cpu]++;
 521                 }
 522                 rcu_read_unlock();
 523                 for_each_online_cpu(cpu) {
 524                         if (resources_per_cpu[cpu] < min) {
 525                                 min = resources_per_cpu[cpu];
 526                                 min_index = cpu;
 527                         }
 528                 }
 529                 kfree(resources_per_cpu);
 530         }
 531         if (min_index == ~0) {
 532                 cpumask_setall(*cpu_mask);
 533                 return;
 534         }
 535         cpumask_set_cpu(min_index, *cpu_mask);
 536 }
 537
 538 /**
 539  * drbd_thread_current_set_cpu() - modifies the cpu mask of the _current_ thread
 540  * @device:     DRBD device.
 541  * @thi:        drbd_thread object
 542  *
 543  * call in the "main loop" of _all_ threads, no need for any mutex, current won't die
 544  * prematurely.
 545  */
 546 void drbd_thread_current_set_cpu(struct drbd_thread *thi)
 547 {
 548         struct drbd_resource *resource = thi->resource;
 549         struct task_struct *p = current;
 550
 551         if (!thi->reset_cpu_mask)
 552                 return;
 553         thi->reset_cpu_mask = 0;
 554         set_cpus_allowed_ptr(p, resource->cpu_mask);
 555 }
 556 #else
 557 #define drbd_calc_cpu_mask(A) ({})
 558 #endif
 559
 560 /**
 561  * drbd_header_size  -  size of a packet header
 562  *
 563  * The header size is a multiple of 8, so any payload following the header is
 564  * word aligned on 64-bit architectures.  (The bitmap send and receive code
 565  * relies on this.)
 566  */
 567 unsigned int drbd_header_size(struct drbd_connection *connection)
 568 {
 569         if (connection->agreed_pro_version >= 100) {
 570                 BUILD_BUG_ON(!IS_ALIGNED(sizeof(struct p_header100), 8));
 571                 return sizeof(struct p_header100);
 572         } else {
 573                 BUILD_BUG_ON(sizeof(struct p_header80) !=
 574                              sizeof(struct p_header95));
 575                 BUILD_BUG_ON(!IS_ALIGNED(sizeof(struct p_header80), 8));
 576                 return sizeof(struct p_header80);
 577         }
 578 }
 579
 580 static unsigned int prepare_header80(struct p_header80 *h, enum drbd_packet cmd, int size)
 581 {
 582         h->magic   = cpu_to_be32(DRBD_MAGIC);
 583         h->command = cpu_to_be16(cmd);
 584         h->length  = cpu_to_be16(size);
 585         return sizeof(struct p_header80);
 586 }
 587
 588 static unsigned int prepare_header95(struct p_header95 *h, enum drbd_packet cmd, int size)
 589 {
 590         h->magic   = cpu_to_be16(DRBD_MAGIC_BIG);
 591         h->command = cpu_to_be16(cmd);
 592         h->length = cpu_to_be32(size);
 593         return sizeof(struct p_header95);
 594 }
 595
 596 static unsigned int prepare_header100(struct p_header100 *h, enum drbd_packet cmd,
 597                                       int size, int vnr)
 598 {
 599         h->magic = cpu_to_be32(DRBD_MAGIC_100);
 600         h->volume = cpu_to_be16(vnr);
 601         h->command = cpu_to_be16(cmd);
 602         h->length = cpu_to_be32(size);
 603         h->pad = 0;
 604         return sizeof(struct p_header100);
 605 }
 606
 607 static unsigned int prepare_header(struct drbd_connection *connection, int vnr,
 608                                    void *buffer, enum drbd_packet cmd, int size)
 609 {
 610         if (connection->agreed_pro_version >= 100)
 611                 return prepare_header100(buffer, cmd, size, vnr);
 612         else if (connection->agreed_pro_version >= 95 &&
 613                  size > DRBD_MAX_SIZE_H80_PACKET)
 614                 return prepare_header95(buffer, cmd, size);
 615         else
 616                 return prepare_header80(buffer, cmd, size);
 617 }
 618
 619 static void *__conn_prepare_command(struct drbd_connection *connection,
 620                                     struct drbd_socket *sock)
 621 {
 622         if (!sock->socket)
 623                 return NULL;
 624         return sock->sbuf + drbd_header_size(connection);
 625 }
 626
 627 void *conn_prepare_command(struct drbd_connection *connection, struct drbd_socket *sock)
 628 {
 629         void *p;
 630
 631         mutex_lock(&sock->mutex);
 632         p = __conn_prepare_command(connection, sock);
 633         if (!p)
 634                 mutex_unlock(&sock->mutex);
 635
 636         return p;
 637 }
 638
 639 void *drbd_prepare_command(struct drbd_peer_device *peer_device, struct drbd_socket *sock)
 640 {
 641         return conn_prepare_command(peer_device->connection, sock);
 642 }
 643
 644 static int __send_command(struct drbd_connection *connection, int vnr,
 645                           struct drbd_socket *sock, enum drbd_packet cmd,
 646                           unsigned int header_size, void *data,
 647                           unsigned int size)
 648 {
 649         int msg_flags;
 650         int err;
 651
 652         /*
 653          * Called with @data == NULL and the size of the data blocks in @size
 654          * for commands that send data blocks.  For those commands, omit the
 655          * MSG_MORE flag: this will increase the likelihood that data blocks
 656          * which are page aligned on the sender will end up page aligned on the
 657          * receiver.
 658          */
 659         msg_flags = data ? MSG_MORE : 0;
 660
 661         header_size += prepare_header(connection, vnr, sock->sbuf, cmd,
 662                                       header_size + size);
 663         err = drbd_send_all(connection, sock->socket, sock->sbuf, header_size,
 664                             msg_flags);
 665         if (data && !err)
 666                 err = drbd_send_all(connection, sock->socket, data, size, 0);
 667         /* DRBD protocol "pings" are latency critical.
 668          * This is supposed to trigger tcp_push_pending_frames() */
 669         if (!err && (cmd == P_PING || cmd == P_PING_ACK))
 670                 drbd_tcp_nodelay(sock->socket);
 671
 672         return err;
 673 }
 674
 675 static int __conn_send_command(struct drbd_connection *connection, struct drbd_socket *sock,
 676                                enum drbd_packet cmd, unsigned int header_size,
 677                                void *data, unsigned int size)
 678 {
 679         return __send_command(connection, 0, sock, cmd, header_size, data, size);
 680 }
 681
 682 int conn_send_command(struct drbd_connection *connection, struct drbd_socket *sock,
 683                       enum drbd_packet cmd, unsigned int header_size,
 684                       void *data, unsigned int size)
 685 {
 686         int err;
 687
 688         err = __conn_send_command(connection, sock, cmd, header_size, data, size);
 689         mutex_unlock(&sock->mutex);
 690         return err;
 691 }
 692
 693 int drbd_send_command(struct drbd_peer_device *peer_device, struct drbd_socket *sock,
 694                       enum drbd_packet cmd, unsigned int header_size,
 695                       void *data, unsigned int size)
 696 {
 697         int err;
 698
 699         err = __send_command(peer_device->connection, peer_device->device->vnr,
 700                              sock, cmd, header_size, data, size);
 701         mutex_unlock(&sock->mutex);
 702         return err;
 703 }
 704
 705 int drbd_send_ping(struct drbd_connection *connection)
 706 {
 707         struct drbd_socket *sock;
 708
 709         sock = &connection->meta;
 710         if (!conn_prepare_command(connection, sock))
 711                 return -EIO;
 712         return conn_send_command(connection, sock, P_PING, 0, NULL, 0);
 713 }
 714
 715 int drbd_send_ping_ack(struct drbd_connection *connection)
 716 {
 717         struct drbd_socket *sock;
 718
 719         sock = &connection->meta;
 720         if (!conn_prepare_command(connection, sock))
 721                 return -EIO;
 722         return conn_send_command(connection, sock, P_PING_ACK, 0, NULL, 0);
 723 }
 724
 725 int drbd_send_sync_param(struct drbd_peer_device *peer_device)
 726 {
 727         struct drbd_socket *sock;
 728         struct p_rs_param_95 *p;
 729         int size;
 730         const int apv = peer_device->connection->agreed_pro_version;
 731         enum drbd_packet cmd;
 732         struct net_conf *nc;
 733         struct disk_conf *dc;
 734
 735         sock = &peer_device->connection->data;
 736         p = drbd_prepare_command(peer_device, sock);
 737         if (!p)
 738                 return -EIO;
 739
 740         rcu_read_lock();
 741         nc = rcu_dereference(peer_device->connection->net_conf);
 742
 743         size = apv <= 87 ? sizeof(struct p_rs_param)
 744                 : apv == 88 ? sizeof(struct p_rs_param)
 745                         + strlen(nc->verify_alg) + 1
 746                 : apv <= 94 ? sizeof(struct p_rs_param_89)
 747                 : /* apv >= 95 */ sizeof(struct p_rs_param_95);
 748
 749         cmd = apv >= 89 ? P_SYNC_PARAM89 : P_SYNC_PARAM;
 750
 751         /* initialize verify_alg and csums_alg */
 752         memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);
 753
 754         if (get_ldev(peer_device->device)) {
 755                 dc = rcu_dereference(peer_device->device->ldev->disk_conf);
 756                 p->resync_rate = cpu_to_be32(dc->resync_rate);
 757                 p->c_plan_ahead = cpu_to_be32(dc->c_plan_ahead);
 758                 p->c_delay_target = cpu_to_be32(dc->c_delay_target);
 759                 p->c_fill_target = cpu_to_be32(dc->c_fill_target);
 760                 p->c_max_rate = cpu_to_be32(dc->c_max_rate);
 761                 put_ldev(peer_device->device);
 762         } else {
 763                 p->resync_rate = cpu_to_be32(DRBD_RESYNC_RATE_DEF);
 764                 p->c_plan_ahead = cpu_to_be32(DRBD_C_PLAN_AHEAD_DEF);
 765                 p->c_delay_target = cpu_to_be32(DRBD_C_DELAY_TARGET_DEF);
 766                 p->c_fill_target = cpu_to_be32(DRBD_C_FILL_TARGET_DEF);
 767                 p->c_max_rate = cpu_to_be32(DRBD_C_MAX_RATE_DEF);
 768         }
 769
 770         if (apv >= 88)
 771                 strcpy(p->verify_alg, nc->verify_alg);
 772         if (apv >= 89)
 773                 strcpy(p->csums_alg, nc->csums_alg);
 774         rcu_read_unlock();
 775
 776         return drbd_send_command(peer_device, sock, cmd, size, NULL, 0);
 777 }
 778
 779 int __drbd_send_protocol(struct drbd_connection *connection, enum drbd_packet cmd)
 780 {
 781         struct drbd_socket *sock;
 782         struct p_protocol *p;
 783         struct net_conf *nc;
 784         int size, cf;
 785
 786         sock = &connection->data;
 787         p = __conn_prepare_command(connection, sock);
 788         if (!p)
 789                 return -EIO;
 790
 791         rcu_read_lock();
 792         nc = rcu_dereference(connection->net_conf);
 793
 794         if (nc->tentative && connection->agreed_pro_version < 92) {
 795                 rcu_read_unlock();
 796                 mutex_unlock(&sock->mutex);
 797                 drbd_err(connection, "--dry-run is not supported by peer");
 798                 return -EOPNOTSUPP;
 799         }
 800
 801         size = sizeof(*p);
 802         if (connection->agreed_pro_version >= 87)
 803                 size += strlen(nc->integrity_alg) + 1;
 804
 805         p->protocol      = cpu_to_be32(nc->wire_protocol);
 806         p->after_sb_0p   = cpu_to_be32(nc->after_sb_0p);
 807         p->after_sb_1p   = cpu_to_be32(nc->after_sb_1p);
 808         p->after_sb_2p   = cpu_to_be32(nc->after_sb_2p);
 809         p->two_primaries = cpu_to_be32(nc->two_primaries);
 810         cf = 0;
 811         if (nc->discard_my_data)
 812                 cf |= CF_DISCARD_MY_DATA;
 813         if (nc->tentative)
 814                 cf |= CF_DRY_RUN;
 815         p->conn_flags    = cpu_to_be32(cf);
 816
 817         if (connection->agreed_pro_version >= 87)
 818                 strcpy(p->integrity_alg, nc->integrity_alg);
 819         rcu_read_unlock();
 820
 821         return __conn_send_command(connection, sock, cmd, size, NULL, 0);
 822 }
 823
 824 int drbd_send_protocol(struct drbd_connection *connection)
 825 {
 826         int err;
 827
 828         mutex_lock(&connection->data.mutex);
 829         err = __drbd_send_protocol(connection, P_PROTOCOL);
 830         mutex_unlock(&connection->data.mutex);
 831
 832         return err;
 833 }
 834
 835 static int _drbd_send_uuids(struct drbd_peer_device *peer_device, u64 uuid_flags)
 836 {
 837         struct drbd_device *device = peer_device->device;
 838         struct drbd_socket *sock;
 839         struct p_uuids *p;
 840         int i;
 841
 842         if (!get_ldev_if_state(device, D_NEGOTIATING))
 843                 return 0;
 844
 845         sock = &peer_device->connection->data;
 846         p = drbd_prepare_command(peer_device, sock);
 847         if (!p) {
 848                 put_ldev(device);
 849                 return -EIO;
 850         }
 851         spin_lock_irq(&device->ldev->md.uuid_lock);
 852         for (i = UI_CURRENT; i < UI_SIZE; i++)
 853                 p->uuid[i] = cpu_to_be64(device->ldev->md.uuid[i]);
 854         spin_unlock_irq(&device->ldev->md.uuid_lock);
 855
 856         device->comm_bm_set = drbd_bm_total_weight(device);
 857         p->uuid[UI_SIZE] = cpu_to_be64(device->comm_bm_set);
 858         rcu_read_lock();
 859         uuid_flags |= rcu_dereference(peer_device->connection->net_conf)->discard_my_data ? 1 : 0;
 860         rcu_read_unlock();
 861         uuid_flags |= test_bit(CRASHED_PRIMARY, &device->flags) ? 2 : 0;
 862         uuid_flags |= device->new_state_tmp.disk == D_INCONSISTENT ? 4 : 0;
 863         p->uuid[UI_FLAGS] = cpu_to_be64(uuid_flags);
 864
 865         put_ldev(device);
 866         return drbd_send_command(peer_device, sock, P_UUIDS, sizeof(*p), NULL, 0);
 867 }
 868
 869 int drbd_send_uuids(struct drbd_peer_device *peer_device)
 870 {
 871         return _drbd_send_uuids(peer_device, 0);
 872 }
 873
 874 int drbd_send_uuids_skip_initial_sync(struct drbd_peer_device *peer_device)
 875 {
 876         return _drbd_send_uuids(peer_device, 8);
 877 }
 878
 879 void drbd_print_uuids(struct drbd_device *device, const char *text)
 880 {
 881         if (get_ldev_if_state(device, D_NEGOTIATING)) {
 882                 u64 *uuid = device->ldev->md.uuid;
 883                 drbd_info(device, "%s %016llX:%016llX:%016llX:%016llX\n",
 884                      text,
 885                      (unsigned long long)uuid[UI_CURRENT],
 886                      (unsigned long long)uuid[UI_BITMAP],
 887                      (unsigned long long)uuid[UI_HISTORY_START],
 888                      (unsigned long long)uuid[UI_HISTORY_END]);
 889                 put_ldev(device);
 890         } else {
 891                 drbd_info(device, "%s effective data uuid: %016llX\n",
 892                                 text,
 893                                 (unsigned long long)device->ed_uuid);
 894         }
 895 }
 896
 897 void drbd_gen_and_send_sync_uuid(struct drbd_peer_device *peer_device)
 898 {
 899         struct drbd_device *device = peer_device->device;
 900         struct drbd_socket *sock;
 901         struct p_rs_uuid *p;
 902         u64 uuid;
 903
 904         D_ASSERT(device, device->state.disk == D_UP_TO_DATE);
 905
 906         uuid = device->ldev->md.uuid[UI_BITMAP];
 907         if (uuid && uuid != UUID_JUST_CREATED)
 908                 uuid = uuid + UUID_NEW_BM_OFFSET;
 909         else
 910                 get_random_bytes(&uuid, sizeof(u64));
 911         drbd_uuid_set(device, UI_BITMAP, uuid);
 912         drbd_print_uuids(device, "updated sync UUID");
 913         drbd_md_sync(device);
 914
 915         sock = &peer_device->connection->data;
 916         p = drbd_prepare_command(peer_device, sock);
 917         if (p) {
 918                 p->uuid = cpu_to_be64(uuid);
 919                 drbd_send_command(peer_device, sock, P_SYNC_UUID, sizeof(*p), NULL, 0);
 920         }
 921 }
 922
 923 /* communicated if (agreed_features & DRBD_FF_WSAME) */
 924 void assign_p_sizes_qlim(struct drbd_device *device, struct p_sizes *p, struct request_queue *q)
 925 {
 926         if (q) {
 927                 p->qlim->physical_block_size = cpu_to_be32(queue_physical_block_size(q));
 928                 p->qlim->logical_block_size = cpu_to_be32(queue_logical_block_size(q));
 929                 p->qlim->alignment_offset = cpu_to_be32(queue_alignment_offset(q));
 930                 p->qlim->io_min = cpu_to_be32(queue_io_min(q));
 931                 p->qlim->io_opt = cpu_to_be32(queue_io_opt(q));
 932                 p->qlim->discard_enabled = blk_queue_discard(q);
 933                 p->qlim->discard_zeroes_data = queue_discard_zeroes_data(q);
 934                 p->qlim->write_same_capable = !!q->limits.max_write_same_sectors;
 935         } else {
 936                 q = device->rq_queue;
 937                 p->qlim->physical_block_size = cpu_to_be32(queue_physical_block_size(q));
 938                 p->qlim->logical_block_size = cpu_to_be32(queue_logical_block_size(q));
 939                 p->qlim->alignment_offset = 0;
 940                 p->qlim->io_min = cpu_to_be32(queue_io_min(q));
 941                 p->qlim->io_opt = cpu_to_be32(queue_io_opt(q));
 942                 p->qlim->discard_enabled = 0;
 943                 p->qlim->discard_zeroes_data = 0;
 944                 p->qlim->write_same_capable = 0;
 945         }
 946 }
 947
 948 int drbd_send_sizes(struct drbd_peer_device *peer_device, int trigger_reply, enum dds_flags flags)
 949 {
 950         struct drbd_device *device = peer_device->device;
 951         struct drbd_socket *sock;
 952         struct p_sizes *p;
 953         sector_t d_size, u_size;
 954         int q_order_type;
 955         unsigned int max_bio_size;
 956         unsigned int packet_size;
 957
 958         sock = &peer_device->connection->data;
 959         p = drbd_prepare_command(peer_device, sock);
 960         if (!p)
 961                 return -EIO;
 962
 963         packet_size = sizeof(*p);
 964         if (peer_device->connection->agreed_features & DRBD_FF_WSAME)
 965                 packet_size += sizeof(p->qlim[0]);
 966
 967         memset(p, 0, packet_size);
 968         if (get_ldev_if_state(device, D_NEGOTIATING)) {
 969                 struct request_queue *q = bdev_get_queue(device->ldev->backing_bdev);
 970                 d_size = drbd_get_max_capacity(device->ldev);
 971                 rcu_read_lock();
 972                 u_size = rcu_dereference(device->ldev->disk_conf)->disk_size;
 973                 rcu_read_unlock();
 974                 q_order_type = drbd_queue_order_type(device);
 975                 max_bio_size = queue_max_hw_sectors(q) << 9;
 976                 max_bio_size = min(max_bio_size, DRBD_MAX_BIO_SIZE);
 977                 assign_p_sizes_qlim(device, p, q);
 978                 put_ldev(device);
 979         } else {
 980                 d_size = 0;
 981                 u_size = 0;
 982                 q_order_type = QUEUE_ORDERED_NONE;
 983                 max_bio_size = DRBD_MAX_BIO_SIZE; /* ... multiple BIOs per peer_request */
 984                 assign_p_sizes_qlim(device, p, NULL);
 985         }
 986
 987         if (peer_device->connection->agreed_pro_version <= 94)
 988                 max_bio_size = min(max_bio_size, DRBD_MAX_SIZE_H80_PACKET);
 989         else if (peer_device->connection->agreed_pro_version < 100)
 990                 max_bio_size = min(max_bio_size, DRBD_MAX_BIO_SIZE_P95);
 991
 992         p->d_size = cpu_to_be64(d_size);
 993         p->u_size = cpu_to_be64(u_size);
 994         p->c_size = cpu_to_be64(trigger_reply ? 0 : drbd_get_capacity(device->this_bdev));
 995         p->max_bio_size = cpu_to_be32(max_bio_size);
 996         p->queue_order_type = cpu_to_be16(q_order_type);
 997         p->dds_flags = cpu_to_be16(flags);
 998
 999         return drbd_send_command(peer_device, sock, P_SIZES, packet_size, NULL, 0);
1000 }
1001
1002 /**
1003  * drbd_send_current_state() - Sends the drbd state to the peer
1004  * @peer_device:        DRBD peer device.
1005  */
1006 int drbd_send_current_state(struct drbd_peer_device *peer_device)
1007 {
1008         struct drbd_socket *sock;
1009         struct p_state *p;
1010
1011         sock = &peer_device->connection->data;
1012         p = drbd_prepare_command(peer_device, sock);
1013         if (!p)
1014                 return -EIO;
1015         p->state = cpu_to_be32(peer_device->device->state.i); /* Within the send mutex */
1016         return drbd_send_command(peer_device, sock, P_STATE, sizeof(*p), NULL, 0);
1017 }
1018
1019 /**
1020  * drbd_send_state() - After a state change, sends the new state to the peer
1021  * @peer_device:      DRBD peer device.
1022  * @state:     the state to send, not necessarily the current state.
1023  *
1024  * Each state change queues an "after_state_ch" work, which will eventually
1025  * send the resulting new state to the peer. If more state changes happen
1026  * between queuing and processing of the after_state_ch work, we still
1027  * want to send each intermediary state in the order it occurred.
1028  */
1029 int drbd_send_state(struct drbd_peer_device *peer_device, union drbd_state state)
1030 {
1031         struct drbd_socket *sock;
1032         struct p_state *p;
1033
1034         sock = &peer_device->connection->data;
1035         p = drbd_prepare_command(peer_device, sock);
1036         if (!p)
1037                 return -EIO;
1038         p->state = cpu_to_be32(state.i); /* Within the send mutex */
1039         return drbd_send_command(peer_device, sock, P_STATE, sizeof(*p), NULL, 0);
1040 }
1041
1042 int drbd_send_state_req(struct drbd_peer_device *peer_device, union drbd_state mask, union drbd_state val)
1043 {
1044         struct drbd_socket *sock;
1045         struct p_req_state *p;
1046
1047         sock = &peer_device->connection->data;
1048         p = drbd_prepare_command(peer_device, sock);
1049         if (!p)
1050                 return -EIO;
1051         p->mask = cpu_to_be32(mask.i);
1052         p->val = cpu_to_be32(val.i);
1053         return drbd_send_command(peer_device, sock, P_STATE_CHG_REQ, sizeof(*p), NULL, 0);
1054 }
1055
1056 int conn_send_state_req(struct drbd_connection *connection, union drbd_state mask, union drbd_state val)
1057 {
1058         enum drbd_packet cmd;
1059         struct drbd_socket *sock;
1060         struct p_req_state *p;
1061
1062         cmd = connection->agreed_pro_version < 100 ? P_STATE_CHG_REQ : P_CONN_ST_CHG_REQ;
1063         sock = &connection->data;
1064         p = conn_prepare_command(connection, sock);
1065         if (!p)
1066                 return -EIO;
1067         p->mask = cpu_to_be32(mask.i);
1068         p->val = cpu_to_be32(val.i);
1069         return conn_send_command(connection, sock, cmd, sizeof(*p), NULL, 0);
1070 }
1071
1072 void drbd_send_sr_reply(struct drbd_peer_device *peer_device, enum drbd_state_rv retcode)
1073 {
1074         struct drbd_socket *sock;
1075         struct p_req_state_reply *p;
1076
1077         sock = &peer_device->connection->meta;
1078         p = drbd_prepare_command(peer_device, sock);
1079         if (p) {
1080                 p->retcode = cpu_to_be32(retcode);
1081                 drbd_send_command(peer_device, sock, P_STATE_CHG_REPLY, sizeof(*p), NULL, 0);
1082         }
1083 }
1084
1085 void conn_send_sr_reply(struct drbd_connection *connection, enum drbd_state_rv retcode)
1086 {
1087         struct drbd_socket *sock;
1088         struct p_req_state_reply *p;
1089         enum drbd_packet cmd = connection->agreed_pro_version < 100 ? P_STATE_CHG_REPLY : P_CONN_ST_CHG_REPLY;
1090
1091         sock = &connection->meta;
1092         p = conn_prepare_command(connection, sock);
1093         if (p) {
1094                 p->retcode = cpu_to_be32(retcode);
1095                 conn_send_command(connection, sock, cmd, sizeof(*p), NULL, 0);
1096         }
1097 }
1098
1099 static void dcbp_set_code(struct p_compressed_bm *p, enum drbd_bitmap_code code)
1100 {
1101         BUG_ON(code & ~0xf);
1102         p->encoding = (p->encoding & ~0xf) | code;
1103 }
1104
1105 static void dcbp_set_start(struct p_compressed_bm *p, int set)
1106 {
1107         p->encoding = (p->encoding & ~0x80) | (set ? 0x80 : 0);
1108 }
1109
1110 static void dcbp_set_pad_bits(struct p_compressed_bm *p, int n)
1111 {
1112         BUG_ON(n & ~0x7);
1113         p->encoding = (p->encoding & (~0x7 << 4)) | (n << 4);
1114 }
1115
1116 static int fill_bitmap_rle_bits(struct drbd_device *device,
1117                          struct p_compressed_bm *p,
1118                          unsigned int size,
1119                          struct bm_xfer_ctx *c)
1120 {
1121         struct bitstream bs;
1122         unsigned long plain_bits;
1123         unsigned long tmp;
1124         unsigned long rl;
1125         unsigned len;
1126         unsigned toggle;
1127         int bits, use_rle;
1128
1129         /* may we use this feature? */
1130         rcu_read_lock();
1131         use_rle = rcu_dereference(first_peer_device(device)->connection->net_conf)->use_rle;
1132         rcu_read_unlock();
1133         if (!use_rle || first_peer_device(device)->connection->agreed_pro_version < 90)
1134                 return 0;
1135
1136         if (c->bit_offset >= c->bm_bits)
1137                 return 0; /* nothing to do. */
1138
1139         /* use at most thus many bytes */
1140         bitstream_init(&bs, p->code, size, 0);
1141         memset(p->code, 0, size);
1142         /* plain bits covered in this code string */
1143         plain_bits = 0;
1144
1145         /* p->encoding & 0x80 stores whether the first run length is set.
1146          * bit offset is implicit.
1147          * start with toggle == 2 to be able to tell the first iteration */
1148         toggle = 2;
1149
1150         /* see how much plain bits we can stuff into one packet
1151          * using RLE and VLI. */
1152         do {
1153                 tmp = (toggle == 0) ? _drbd_bm_find_next_zero(device, c->bit_offset)
1154                                     : _drbd_bm_find_next(device, c->bit_offset);
1155                 if (tmp == -1UL)
1156                         tmp = c->bm_bits;
1157                 rl = tmp - c->bit_offset;
1158
1159                 if (toggle == 2) { /* first iteration */
1160                         if (rl == 0) {
1161                                 /* the first checked bit was set,
1162                                  * store start value, */
1163                                 dcbp_set_start(p, 1);
1164                                 /* but skip encoding of zero run length */
1165                                 toggle = !toggle;
1166                                 continue;
1167                         }
1168                         dcbp_set_start(p, 0);
1169                 }
1170
1171                 /* paranoia: catch zero runlength.
1172                  * can only happen if bitmap is modified while we scan it. */
1173                 if (rl == 0) {
1174                         drbd_err(device, "unexpected zero runlength while encoding bitmap "
1175                             "t:%u bo:%lu\n", toggle, c->bit_offset);
1176                         return -1;
1177                 }
1178
1179                 bits = vli_encode_bits(&bs, rl);
1180                 if (bits == -ENOBUFS) /* buffer full */
1181                         break;
1182                 if (bits <= 0) {
1183                         drbd_err(device, "error while encoding bitmap: %d\n", bits);
1184                         return 0;
1185                 }
1186
1187                 toggle = !toggle;
1188                 plain_bits += rl;
1189                 c->bit_offset = tmp;
1190         } while (c->bit_offset < c->bm_bits);
1191
1192         len = bs.cur.b - p->code + !!bs.cur.bit;
1193
1194         if (plain_bits < (len << 3)) {
1195                 /* incompressible with this method.
1196                  * we need to rewind both word and bit position. */
1197                 c->bit_offset -= plain_bits;
1198                 bm_xfer_ctx_bit_to_word_offset(c);
1199                 c->bit_offset = c->word_offset * BITS_PER_LONG;
1200                 return 0;
1201         }
1202
1203         /* RLE + VLI was able to compress it just fine.
1204          * update c->word_offset. */
1205         bm_xfer_ctx_bit_to_word_offset(c);
1206
1207         /* store pad_bits */
1208         dcbp_set_pad_bits(p, (8 - bs.cur.bit) & 0x7);
1209
1210         return len;
1211 }
1212
1213 /**
1214  * send_bitmap_rle_or_plain
1215  *
1216  * Return 0 when done, 1 when another iteration is needed, and a negative error
1217  * code upon failure.
1218  */
1219 static int
1220 send_bitmap_rle_or_plain(struct drbd_device *device, struct bm_xfer_ctx *c)
1221 {
1222         struct drbd_socket *sock = &first_peer_device(device)->connection->data;
1223         unsigned int header_size = drbd_header_size(first_peer_device(device)->connection);
1224         struct p_compressed_bm *p = sock->sbuf + header_size;
1225         int len, err;
1226
1227         len = fill_bitmap_rle_bits(device, p,
1228                         DRBD_SOCKET_BUFFER_SIZE - header_size - sizeof(*p), c);
1229         if (len < 0)
1230                 return -EIO;
1231
1232         if (len) {
1233                 dcbp_set_code(p, RLE_VLI_Bits);
1234                 err = __send_command(first_peer_device(device)->connection, device->vnr, sock,
1235                                      P_COMPRESSED_BITMAP, sizeof(*p) + len,
1236                                      NULL, 0);
1237                 c->packets[0]++;
1238                 c->bytes[0] += header_size + sizeof(*p) + len;
1239
1240                 if (c->bit_offset >= c->bm_bits)
1241                         len = 0; /* DONE */
1242         } else {
1243                 /* was not compressible.
1244                  * send a buffer full of plain text bits instead. */
1245                 unsigned int data_size;
1246                 unsigned long num_words;
1247                 unsigned long *p = sock->sbuf + header_size;
1248
1249                 data_size = DRBD_SOCKET_BUFFER_SIZE - header_size;
1250                 num_words = min_t(size_t, data_size / sizeof(*p),
1251                                   c->bm_words - c->word_offset);
1252                 len = num_words * sizeof(*p);
1253                 if (len)
1254                         drbd_bm_get_lel(device, c->word_offset, num_words, p);
1255                 err = __send_command(first_peer_device(device)->connection, device->vnr, sock, P_BITMAP, len, NULL, 0);
1256                 c->word_offset += num_words;
1257                 c->bit_offset = c->word_offset * BITS_PER_LONG;
1258
1259                 c->packets[1]++;
1260                 c->bytes[1] += header_size + len;
1261
1262                 if (c->bit_offset > c->bm_bits)
1263                         c->bit_offset = c->bm_bits;
1264         }
1265         if (!err) {
1266                 if (len == 0) {
1267                         INFO_bm_xfer_stats(device, "send", c);
1268                         return 0;
1269                 } else
1270                         return 1;
1271         }
1272         return -EIO;
1273 }
1274
1275 /* See the comment at receive_bitmap() */
1276 static int _drbd_send_bitmap(struct drbd_device *device)
1277 {
1278         struct bm_xfer_ctx c;
1279         int err;
1280
1281         if (!expect(device->bitmap))
1282                 return false;
1283
1284         if (get_ldev(device)) {
1285                 if (drbd_md_test_flag(device->ldev, MDF_FULL_SYNC)) {
1286                         drbd_info(device, "Writing the whole bitmap, MDF_FullSync was set.\n");
1287                         drbd_bm_set_all(device);
1288                         if (drbd_bm_write(device)) {
1289                                 /* write_bm did fail! Leave full sync flag set in Meta P_DATA
1290                                  * but otherwise process as per normal - need to tell other
1291                                  * side that a full resync is required! */
1292                                 drbd_err(device, "Failed to write bitmap to disk!\n");
1293                         } else {
1294                                 drbd_md_clear_flag(device, MDF_FULL_SYNC);
1295                                 drbd_md_sync(device);
1296                         }
1297                 }
1298                 put_ldev(device);
1299         }
1300
1301         c = (struct bm_xfer_ctx) {
1302                 .bm_bits = drbd_bm_bits(device),
1303                 .bm_words = drbd_bm_words(device),
1304         };
1305
1306         do {
1307                 err = send_bitmap_rle_or_plain(device, &c);
1308         } while (err > 0);
1309
1310         return err == 0;
1311 }
1312
1313 int drbd_send_bitmap(struct drbd_device *device)
1314 {
1315         struct drbd_socket *sock = &first_peer_device(device)->connection->data;
1316         int err = -1;
1317
1318         mutex_lock(&sock->mutex);
1319         if (sock->socket)
1320                 err = !_drbd_send_bitmap(device);
1321         mutex_unlock(&sock->mutex);
1322         return err;
1323 }
1324
1325 void drbd_send_b_ack(struct drbd_connection *connection, u32 barrier_nr, u32 set_size)
1326 {
1327         struct drbd_socket *sock;
1328         struct p_barrier_ack *p;
1329
1330         if (connection->cstate < C_WF_REPORT_PARAMS)
1331                 return;
1332
1333         sock = &connection->meta;
1334         p = conn_prepare_command(connection, sock);
1335         if (!p)
1336                 return;
1337         p->barrier = barrier_nr;
1338         p->set_size = cpu_to_be32(set_size);
1339         conn_send_command(connection, sock, P_BARRIER_ACK, sizeof(*p), NULL, 0);
1340 }
1341
1342 /**
1343  * _drbd_send_ack() - Sends an ack packet
1344  * @device:     DRBD device.
1345  * @cmd:        Packet command code.
1346  * @sector:     sector, needs to be in big endian byte order
1347  * @blksize:    size in byte, needs to be in big endian byte order
1348  * @block_id:   Id, big endian byte order
1349  */
1350 static int _drbd_send_ack(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1351                           u64 sector, u32 blksize, u64 block_id)
1352 {
1353         struct drbd_socket *sock;
1354         struct p_block_ack *p;
1355
1356         if (peer_device->device->state.conn < C_CONNECTED)
1357                 return -EIO;
1358
1359         sock = &peer_device->connection->meta;
1360         p = drbd_prepare_command(peer_device, sock);
1361         if (!p)
1362                 return -EIO;
1363         p->sector = sector;
1364         p->block_id = block_id;
1365         p->blksize = blksize;
1366         p->seq_num = cpu_to_be32(atomic_inc_return(&peer_device->device->packet_seq));
1367         return drbd_send_command(peer_device, sock, cmd, sizeof(*p), NULL, 0);
1368 }
1369
1370 /* dp->sector and dp->block_id already/still in network byte order,
1371  * data_size is payload size according to dp->head,
1372  * and may need to be corrected for digest size. */
1373 void drbd_send_ack_dp(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1374                       struct p_data *dp, int data_size)
1375 {
1376         if (peer_device->connection->peer_integrity_tfm)
1377                 data_size -= crypto_ahash_digestsize(peer_device->connection->peer_integrity_tfm);
1378         _drbd_send_ack(peer_device, cmd, dp->sector, cpu_to_be32(data_size),
1379                        dp->block_id);
1380 }
1381
1382 void drbd_send_ack_rp(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1383                       struct p_block_req *rp)
1384 {
1385         _drbd_send_ack(peer_device, cmd, rp->sector, rp->blksize, rp->block_id);
1386 }
1387
1388 /**
1389  * drbd_send_ack() - Sends an ack packet
1390  * @device:     DRBD device
1391  * @cmd:        packet command code
1392  * @peer_req:   peer request
1393  */
1394 int drbd_send_ack(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1395                   struct drbd_peer_request *peer_req)
1396 {
1397         return _drbd_send_ack(peer_device, cmd,
1398                               cpu_to_be64(peer_req->i.sector),
1399                               cpu_to_be32(peer_req->i.size),
1400                               peer_req->block_id);
1401 }
1402
1403 /* This function misuses the block_id field to signal if the blocks
1404  * are is sync or not. */
1405 int drbd_send_ack_ex(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1406                      sector_t sector, int blksize, u64 block_id)
1407 {
1408         return _drbd_send_ack(peer_device, cmd,
1409                               cpu_to_be64(sector),
1410                               cpu_to_be32(blksize),
1411                               cpu_to_be64(block_id));
1412 }
1413
1414 int drbd_send_rs_deallocated(struct drbd_peer_device *peer_device,
1415                              struct drbd_peer_request *peer_req)
1416 {
1417         struct drbd_socket *sock;
1418         struct p_block_desc *p;
1419
1420         sock = &peer_device->connection->data;
1421         p = drbd_prepare_command(peer_device, sock);
1422         if (!p)
1423                 return -EIO;
1424         p->sector = cpu_to_be64(peer_req->i.sector);
1425         p->blksize = cpu_to_be32(peer_req->i.size);
1426         p->pad = 0;
1427         return drbd_send_command(peer_device, sock, P_RS_DEALLOCATED, sizeof(*p), NULL, 0);
1428 }
1429
1430 int drbd_send_drequest(struct drbd_peer_device *peer_device, int cmd,
1431                        sector_t sector, int size, u64 block_id)
1432 {
1433         struct drbd_socket *sock;
1434         struct p_block_req *p;
1435
1436         sock = &peer_device->connection->data;
1437         p = drbd_prepare_command(peer_device, sock);
1438         if (!p)
1439                 return -EIO;
1440         p->sector = cpu_to_be64(sector);
1441         p->block_id = block_id;
1442         p->blksize = cpu_to_be32(size);
1443         return drbd_send_command(peer_device, sock, cmd, sizeof(*p), NULL, 0);
1444 }
1445
1446 int drbd_send_drequest_csum(struct drbd_peer_device *peer_device, sector_t sector, int size,
1447                             void *digest, int digest_size, enum drbd_packet cmd)
1448 {
1449         struct drbd_socket *sock;
1450         struct p_block_req *p;
1451
1452         /* FIXME: Put the digest into the preallocated socket buffer.  */
1453
1454         sock = &peer_device->connection->data;
1455         p = drbd_prepare_command(peer_device, sock);
1456         if (!p)
1457                 return -EIO;
1458         p->sector = cpu_to_be64(sector);
1459         p->block_id = ID_SYNCER /* unused */;
1460         p->blksize = cpu_to_be32(size);
1461         return drbd_send_command(peer_device, sock, cmd, sizeof(*p), digest, digest_size);
1462 }
1463
1464 int drbd_send_ov_request(struct drbd_peer_device *peer_device, sector_t sector, int size)
1465 {
1466         struct drbd_socket *sock;
1467         struct p_block_req *p;
1468
1469         sock = &peer_device->connection->data;
1470         p = drbd_prepare_command(peer_device, sock);
1471         if (!p)
1472                 return -EIO;
1473         p->sector = cpu_to_be64(sector);
1474         p->block_id = ID_SYNCER /* unused */;
1475         p->blksize = cpu_to_be32(size);
1476         return drbd_send_command(peer_device, sock, P_OV_REQUEST, sizeof(*p), NULL, 0);
1477 }
1478
1479 /* called on sndtimeo
1480  * returns false if we should retry,
1481  * true if we think connection is dead
1482  */
1483 static int we_should_drop_the_connection(struct drbd_connection *connection, struct socket *sock)
1484 {
1485         int drop_it;
1486         /* long elapsed = (long)(jiffies - device->last_received); */
1487
1488         drop_it =   connection->meta.socket == sock
1489                 || !connection->ack_receiver.task
1490                 || get_t_state(&connection->ack_receiver) != RUNNING
1491                 || connection->cstate < C_WF_REPORT_PARAMS;
1492
1493         if (drop_it)
1494                 return true;
1495
1496         drop_it = !--connection->ko_count;
1497         if (!drop_it) {
1498                 drbd_err(connection, "[%s/%d] sock_sendmsg time expired, ko = %u\n",
1499                          current->comm, current->pid, connection->ko_count);
1500                 request_ping(connection);
1501         }
1502
1503         return drop_it; /* && (device->state == R_PRIMARY) */;
1504 }
1505
1506 static void drbd_update_congested(struct drbd_connection *connection)
1507 {
1508         struct sock *sk = connection->data.socket->sk;
1509         if (sk->sk_wmem_queued > sk->sk_sndbuf * 4 / 5)
1510                 set_bit(NET_CONGESTED, &connection->flags);
1511 }
1512
1513 /* The idea of sendpage seems to be to put some kind of reference
1514  * to the page into the skb, and to hand it over to the NIC. In
1515  * this process get_page() gets called.
1516  *
1517  * As soon as the page was really sent over the network put_page()
1518  * gets called by some part of the network layer. [ NIC driver? ]
1519  *
1520  * [ get_page() / put_page() increment/decrement the count. If count
1521  *   reaches 0 the page will be freed. ]
1522  *
1523  * This works nicely with pages from FSs.
1524  * But this means that in protocol A we might signal IO completion too early!
1525  *
1526  * In order not to corrupt data during a resync we must make sure
1527  * that we do not reuse our own buffer pages (EEs) to early, therefore
1528  * we have the net_ee list.
1529  *
1530  * XFS seems to have problems, still, it submits pages with page_count == 0!
1531  * As a workaround, we disable sendpage on pages
1532  * with page_count == 0 or PageSlab.
1533  */
1534 static int _drbd_no_send_page(struct drbd_peer_device *peer_device, struct page *page,
1535                               int offset, size_t size, unsigned msg_flags)
1536 {
1537         struct socket *socket;
1538         void *addr;
1539         int err;
1540
1541         socket = peer_device->connection->data.socket;
1542         addr = kmap(page) + offset;
1543         err = drbd_send_all(peer_device->connection, socket, addr, size, msg_flags);
1544         kunmap(page);
1545         if (!err)
1546                 peer_device->device->send_cnt += size >> 9;
1547         return err;
1548 }
1549
1550 static int _drbd_send_page(struct drbd_peer_device *peer_device, struct page *page,
1551                     int offset, size_t size, unsigned msg_flags)
1552 {
1553         struct socket *socket = peer_device->connection->data.socket;
1554         mm_segment_t oldfs = get_fs();
1555         int len = size;
1556         int err = -EIO;
1557
1558         /* e.g. XFS meta- & log-data is in slab pages, which have a
1559          * page_count of 0 and/or have PageSlab() set.
1560          * we cannot use send_page for those, as that does get_page();
1561          * put_page(); and would cause either a VM_BUG directly, or
1562          * __page_cache_release a page that would actually still be referenced
1563          * by someone, leading to some obscure delayed Oops somewhere else. */
1564         if (disable_sendpage || (page_count(page) < 1) || PageSlab(page))
1565                 return _drbd_no_send_page(peer_device, page, offset, size, msg_flags);
1566
1567         msg_flags |= MSG_NOSIGNAL;
1568         drbd_update_congested(peer_device->connection);
1569         set_fs(KERNEL_DS);
1570         do {
1571                 int sent;
1572
1573                 sent = socket->ops->sendpage(socket, page, offset, len, msg_flags);
1574                 if (sent <= 0) {
1575                         if (sent == -EAGAIN) {
1576                                 if (we_should_drop_the_connection(peer_device->connection, socket))
1577                                         break;
1578                                 continue;
1579                         }
1580                         drbd_warn(peer_device->device, "%s: size=%d len=%d sent=%d\n",
1581                              __func__, (int)size, len, sent);
1582                         if (sent < 0)
1583                                 err = sent;
1584                         break;
1585                 }
1586                 len    -= sent;
1587                 offset += sent;
1588         } while (len > 0 /* THINK && device->cstate >= C_CONNECTED*/);
1589         set_fs(oldfs);
1590         clear_bit(NET_CONGESTED, &peer_device->connection->flags);
1591
1592         if (len == 0) {
1593                 err = 0;
1594                 peer_device->device->send_cnt += size >> 9;
1595         }
1596         return err;
1597 }
1598
1599 static int _drbd_send_bio(struct drbd_peer_device *peer_device, struct bio *bio)
1600 {
1601         struct bio_vec bvec;
1602         struct bvec_iter iter;
1603
1604         /* hint all but last page with MSG_MORE */
1605         bio_for_each_segment(bvec, bio, iter) {
1606                 int err;
1607
1608                 err = _drbd_no_send_page(peer_device, bvec.bv_page,
1609                                          bvec.bv_offset, bvec.bv_len,
1610                                          bio_iter_last(bvec, iter)
1611                                          ? 0 : MSG_MORE);
1612                 if (err)
1613                         return err;
1614                 /* REQ_OP_WRITE_SAME has only one segment */
1615                 if (bio_op(bio) == REQ_OP_WRITE_SAME)
1616                         break;
1617         }
1618         return 0;
1619 }
1620
1621 static int _drbd_send_zc_bio(struct drbd_peer_device *peer_device, struct bio *bio)
1622 {
1623         struct bio_vec bvec;
1624         struct bvec_iter iter;
1625
1626         /* hint all but last page with MSG_MORE */
1627         bio_for_each_segment(bvec, bio, iter) {
1628                 int err;
1629
1630                 err = _drbd_send_page(peer_device, bvec.bv_page,
1631                                       bvec.bv_offset, bvec.bv_len,
1632                                       bio_iter_last(bvec, iter) ? 0 : MSG_MORE);
1633                 if (err)
1634                         return err;
1635                 /* REQ_OP_WRITE_SAME has only one segment */
1636                 if (bio_op(bio) == REQ_OP_WRITE_SAME)
1637                         break;
1638         }
1639         return 0;
1640 }
1641
1642 static int _drbd_send_zc_ee(struct drbd_peer_device *peer_device,
1643                             struct drbd_peer_request *peer_req)
1644 {
1645         struct page *page = peer_req->pages;
1646         unsigned len = peer_req->i.size;
1647         int err;
1648
1649         /* hint all but last page with MSG_MORE */
1650         page_chain_for_each(page) {
1651                 unsigned l = min_t(unsigned, len, PAGE_SIZE);
1652
1653                 err = _drbd_send_page(peer_device, page, 0, l,
1654                                       page_chain_next(page) ? MSG_MORE : 0);
1655                 if (err)
1656                         return err;
1657                 len -= l;
1658         }
1659         return 0;
1660 }
1661
1662 static u32 bio_flags_to_wire(struct drbd_connection *connection,
1663                              struct bio *bio)
1664 {
1665         if (connection->agreed_pro_version >= 95)
1666                 return  (bio->bi_opf & REQ_SYNC ? DP_RW_SYNC : 0) |
1667                         (bio->bi_opf & REQ_FUA ? DP_FUA : 0) |
1668                         (bio->bi_opf & REQ_PREFLUSH ? DP_FLUSH : 0) |
1669                         (bio_op(bio) == REQ_OP_WRITE_SAME ? DP_WSAME : 0) |
1670                         (bio_op(bio) == REQ_OP_DISCARD ? DP_DISCARD : 0);
1671         else
1672                 return bio->bi_opf & REQ_SYNC ? DP_RW_SYNC : 0;
1673 }
1674
1675 /* Used to send write or TRIM aka REQ_DISCARD requests
1676  * R_PRIMARY -> Peer    (P_DATA, P_TRIM)
1677  */
1678 int drbd_send_dblock(struct drbd_peer_device *peer_device, struct drbd_request *req)
1679 {
1680         struct drbd_device *device = peer_device->device;
1681         struct drbd_socket *sock;
1682         struct p_data *p;
1683         struct p_wsame *wsame = NULL;
1684         void *digest_out;
1685         unsigned int dp_flags = 0;
1686         int digest_size;
1687         int err;
1688
1689         sock = &peer_device->connection->data;
1690         p = drbd_prepare_command(peer_device, sock);
1691         digest_size = peer_device->connection->integrity_tfm ?
1692                       crypto_ahash_digestsize(peer_device->connection->integrity_tfm) : 0;
1693
1694         if (!p)
1695                 return -EIO;
1696         p->sector = cpu_to_be64(req->i.sector);
1697         p->block_id = (unsigned long)req;
1698         p->seq_num = cpu_to_be32(atomic_inc_return(&device->packet_seq));
1699         dp_flags = bio_flags_to_wire(peer_device->connection, req->master_bio);
1700         if (device->state.conn >= C_SYNC_SOURCE &&
1701             device->state.conn <= C_PAUSED_SYNC_T)
1702                 dp_flags |= DP_MAY_SET_IN_SYNC;
1703         if (peer_device->connection->agreed_pro_version >= 100) {
1704                 if (req->rq_state & RQ_EXP_RECEIVE_ACK)
1705                         dp_flags |= DP_SEND_RECEIVE_ACK;
1706                 /* During resync, request an explicit write ack,
1707                  * even in protocol != C */
1708                 if (req->rq_state & RQ_EXP_WRITE_ACK
1709                 || (dp_flags & DP_MAY_SET_IN_SYNC))
1710                         dp_flags |= DP_SEND_WRITE_ACK;
1711         }
1712         p->dp_flags = cpu_to_be32(dp_flags);
1713
1714         if (dp_flags & DP_DISCARD) {
1715                 struct p_trim *t = (struct p_trim*)p;
1716                 t->size = cpu_to_be32(req->i.size);
1717                 err = __send_command(peer_device->connection, device->vnr, sock, P_TRIM, sizeof(*t), NULL, 0);
1718                 goto out;
1719         }
1720         if (dp_flags & DP_WSAME) {
1721                 /* this will only work if DRBD_FF_WSAME is set AND the
1722                  * handshake agreed that all nodes and backend devices are
1723                  * WRITE_SAME capable and agree on logical_block_size */
1724                 wsame = (struct p_wsame*)p;
1725                 digest_out = wsame + 1;
1726                 wsame->size = cpu_to_be32(req->i.size);
1727         } else
1728                 digest_out = p + 1;
1729
1730         /* our digest is still only over the payload.
1731          * TRIM does not carry any payload. */
1732         if (digest_size)
1733                 drbd_csum_bio(peer_device->connection->integrity_tfm, req->master_bio, digest_out);
1734         if (wsame) {
1735                 err =
1736                     __send_command(peer_device->connection, device->vnr, sock, P_WSAME,
1737                                    sizeof(*wsame) + digest_size, NULL,
1738                                    bio_iovec(req->master_bio).bv_len);
1739         } else
1740                 err =
1741                     __send_command(peer_device->connection, device->vnr, sock, P_DATA,
1742                                    sizeof(*p) + digest_size, NULL, req->i.size);
1743         if (!err) {
1744                 /* For protocol A, we have to memcpy the payload into
1745                  * socket buffers, as we may complete right away
1746                  * as soon as we handed it over to tcp, at which point the data
1747                  * pages may become invalid.
1748                  *
1749                  * For data-integrity enabled, we copy it as well, so we can be
1750                  * sure that even if the bio pages may still be modified, it
1751                  * won't change the data on the wire, thus if the digest checks
1752                  * out ok after sending on this side, but does not fit on the
1753                  * receiving side, we sure have detected corruption elsewhere.
1754                  */
1755                 if (!(req->rq_state & (RQ_EXP_RECEIVE_ACK | RQ_EXP_WRITE_ACK)) || digest_size)
1756                         err = _drbd_send_bio(peer_device, req->master_bio);
1757                 else
1758                         err = _drbd_send_zc_bio(peer_device, req->master_bio);
1759
1760                 /* double check digest, sometimes buffers have been modified in flight. */
1761                 if (digest_size > 0 && digest_size <= 64) {
1762                         /* 64 byte, 512 bit, is the largest digest size
1763                          * currently supported in kernel crypto. */
1764                         unsigned char digest[64];
1765                         drbd_csum_bio(peer_device->connection->integrity_tfm, req->master_bio, digest);
1766                         if (memcmp(p + 1, digest, digest_size)) {
1767                                 drbd_warn(device,
1768                                         "Digest mismatch, buffer modified by upper layers during write: %llus +%u\n",
1769                                         (unsigned long long)req->i.sector, req->i.size);
1770                         }
1771                 } /* else if (digest_size > 64) {
1772                      ... Be noisy about digest too large ...
1773                 } */
1774         }
1775 out:
1776         mutex_unlock(&sock->mutex);  /* locked by drbd_prepare_command() */
1777
1778         return err;
1779 }
1780
1781 /* answer packet, used to send data back for read requests:
1782  *  Peer       -> (diskless) R_PRIMARY   (P_DATA_REPLY)
1783  *  C_SYNC_SOURCE -> C_SYNC_TARGET         (P_RS_DATA_REPLY)
1784  */
1785 int drbd_send_block(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1786                     struct drbd_peer_request *peer_req)
1787 {
1788         struct drbd_device *device = peer_device->device;
1789         struct drbd_socket *sock;
1790         struct p_data *p;
1791         int err;
1792         int digest_size;
1793
1794         sock = &peer_device->connection->data;
1795         p = drbd_prepare_command(peer_device, sock);
1796
1797         digest_size = peer_device->connection->integrity_tfm ?
1798                       crypto_ahash_digestsize(peer_device->connection->integrity_tfm) : 0;
1799
1800         if (!p)
1801                 return -EIO;
1802         p->sector = cpu_to_be64(peer_req->i.sector);
1803         p->block_id = peer_req->block_id;
1804         p->seq_num = 0;  /* unused */
1805         p->dp_flags = 0;
1806         if (digest_size)
1807                 drbd_csum_ee(peer_device->connection->integrity_tfm, peer_req, p + 1);
1808         err = __send_command(peer_device->connection, device->vnr, sock, cmd, sizeof(*p) + digest_size, NULL, peer_req->i.size);
1809         if (!err)
1810                 err = _drbd_send_zc_ee(peer_device, peer_req);
1811         mutex_unlock(&sock->mutex);  /* locked by drbd_prepare_command() */
1812
1813         return err;
1814 }
1815
1816 int drbd_send_out_of_sync(struct drbd_peer_device *peer_device, struct drbd_request *req)
1817 {
1818         struct drbd_socket *sock;
1819         struct p_block_desc *p;
1820
1821         sock = &peer_device->connection->data;
1822         p = drbd_prepare_command(peer_device, sock);
1823         if (!p)
1824                 return -EIO;
1825         p->sector = cpu_to_be64(req->i.sector);
1826         p->blksize = cpu_to_be32(req->i.size);
1827         return drbd_send_command(peer_device, sock, P_OUT_OF_SYNC, sizeof(*p), NULL, 0);
1828 }
1829
1830 /*
1831   drbd_send distinguishes two cases:
1832
1833   Packets sent via the data socket "sock"
1834   and packets sent via the meta data socket "msock"
1835
1836                     sock                      msock
1837   -----------------+-------------------------+------------------------------
1838   timeout           conf.timeout / 2          conf.timeout / 2
1839   timeout action    send a ping via msock     Abort communication
1840                                               and close all sockets
1841 */
1842
1843 /*
1844  * you must have down()ed the appropriate [m]sock_mutex elsewhere!
1845  */
1846 int drbd_send(struct drbd_connection *connection, struct socket *sock,
1847               void *buf, size_t size, unsigned msg_flags)
1848 {
1849         struct kvec iov;
1850         struct msghdr msg;
1851         int rv, sent = 0;
1852
1853         if (!sock)
1854                 return -EBADR;
1855
1856         /* THINK  if (signal_pending) return ... ? */
1857
1858         iov.iov_base = buf;
1859         iov.iov_len  = size;
1860
1861         msg.msg_name       = NULL;
1862         msg.msg_namelen    = 0;
1863         msg.msg_control    = NULL;
1864         msg.msg_controllen = 0;
1865         msg.msg_flags      = msg_flags | MSG_NOSIGNAL;
1866
1867         if (sock == connection->data.socket) {
1868                 rcu_read_lock();
1869                 connection->ko_count = rcu_dereference(connection->net_conf)->ko_count;
1870                 rcu_read_unlock();
1871                 drbd_update_congested(connection);
1872         }
1873         do {
1874                 rv = kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
1875                 if (rv == -EAGAIN) {
1876                         if (we_should_drop_the_connection(connection, sock))
1877                                 break;
1878                         else
1879                                 continue;
1880                 }
1881                 if (rv == -EINTR) {
1882                         flush_signals(current);
1883                         rv = 0;
1884                 }
1885                 if (rv < 0)
1886                         break;
1887                 sent += rv;
1888                 iov.iov_base += rv;
1889                 iov.iov_len  -= rv;
1890         } while (sent < size);
1891
1892         if (sock == connection->data.socket)
1893                 clear_bit(NET_CONGESTED, &connection->flags);
1894
1895         if (rv <= 0) {
1896                 if (rv != -EAGAIN) {
1897                         drbd_err(connection, "%s_sendmsg returned %d\n",
1898                                  sock == connection->meta.socket ? "msock" : "sock",
1899                                  rv);
1900                         conn_request_state(connection, NS(conn, C_BROKEN_PIPE), CS_HARD);
1901                 } else
1902                         conn_request_state(connection, NS(conn, C_TIMEOUT), CS_HARD);
1903         }
1904
1905         return sent;
1906 }
1907
1908 /**
1909  * drbd_send_all  -  Send an entire buffer
1910  *
1911  * Returns 0 upon success and a negative error value otherwise.
1912  */
1913 int drbd_send_all(struct drbd_connection *connection, struct socket *sock, void *buffer,
1914                   size_t size, unsigned msg_flags)
1915 {
1916         int err;
1917
1918         err = drbd_send(connection, sock, buffer, size, msg_flags);
1919         if (err < 0)
1920                 return err;
1921         if (err != size)
1922                 return -EIO;
1923         return 0;
1924 }
1925
1926 static int drbd_open(struct block_device *bdev, fmode_t mode)
1927 {
1928         struct drbd_device *device = bdev->bd_disk->private_data;
1929         unsigned long flags;
1930         int rv = 0;
1931
1932         mutex_lock(&drbd_main_mutex);
1933         spin_lock_irqsave(&device->resource->req_lock, flags);
1934         /* to have a stable device->state.role
1935          * and no race with updating open_cnt */
1936
1937         if (device->state.role != R_PRIMARY) {
1938                 if (mode & FMODE_WRITE)
1939                         rv = -EROFS;
1940                 else if (!allow_oos)
1941                         rv = -EMEDIUMTYPE;
1942         }
1943
1944         if (!rv)
1945                 device->open_cnt++;
1946         spin_unlock_irqrestore(&device->resource->req_lock, flags);
1947         mutex_unlock(&drbd_main_mutex);
1948
1949         return rv;
1950 }
1951
1952 static void drbd_release(struct gendisk *gd, fmode_t mode)
1953 {
1954         struct drbd_device *device = gd->private_data;
1955         mutex_lock(&drbd_main_mutex);
1956         device->open_cnt--;
1957         mutex_unlock(&drbd_main_mutex);
1958 }
1959
1960 static void drbd_set_defaults(struct drbd_device *device)
1961 {
1962         /* Beware! The actual layout differs
1963          * between big endian and little endian */
1964         device->state = (union drbd_dev_state) {
1965                 { .role = R_SECONDARY,
1966                   .peer = R_UNKNOWN,
1967                   .conn = C_STANDALONE,
1968                   .disk = D_DISKLESS,
1969                   .pdsk = D_UNKNOWN,
1970                 } };
1971 }
1972
1973 void drbd_init_set_defaults(struct drbd_device *device)
1974 {
1975         /* the memset(,0,) did most of this.
1976          * note: only assignments, no allocation in here */
1977
1978         drbd_set_defaults(device);
1979
1980         atomic_set(&device->ap_bio_cnt, 0);
1981         atomic_set(&device->ap_actlog_cnt, 0);
1982         atomic_set(&device->ap_pending_cnt, 0);
1983         atomic_set(&device->rs_pending_cnt, 0);
1984         atomic_set(&device->unacked_cnt, 0);
1985         atomic_set(&device->local_cnt, 0);
1986         atomic_set(&device->pp_in_use_by_net, 0);
1987         atomic_set(&device->rs_sect_in, 0);
1988         atomic_set(&device->rs_sect_ev, 0);
1989         atomic_set(&device->ap_in_flight, 0);
1990         atomic_set(&device->md_io.in_use, 0);
1991
1992         mutex_init(&device->own_state_mutex);
1993         device->state_mutex = &device->own_state_mutex;
1994
1995         spin_lock_init(&device->al_lock);
1996         spin_lock_init(&device->peer_seq_lock);
1997
1998         INIT_LIST_HEAD(&device->active_ee);
1999         INIT_LIST_HEAD(&device->sync_ee);
2000         INIT_LIST_HEAD(&device->done_ee);
2001         INIT_LIST_HEAD(&device->read_ee);
2002         INIT_LIST_HEAD(&device->net_ee);
2003         INIT_LIST_HEAD(&device->resync_reads);
2004         INIT_LIST_HEAD(&device->resync_work.list);
2005         INIT_LIST_HEAD(&device->unplug_work.list);
2006         INIT_LIST_HEAD(&device->bm_io_work.w.list);
2007         INIT_LIST_HEAD(&device->pending_master_completion[0]);
2008         INIT_LIST_HEAD(&device->pending_master_completion[1]);
2009         INIT_LIST_HEAD(&device->pending_completion[0]);
2010         INIT_LIST_HEAD(&device->pending_completion[1]);
2011
2012         device->resync_work.cb  = w_resync_timer;
2013         device->unplug_work.cb  = w_send_write_hint;
2014         device->bm_io_work.w.cb = w_bitmap_io;
2015
2016         init_timer(&device->resync_timer);
2017         init_timer(&device->md_sync_timer);
2018         init_timer(&device->start_resync_timer);
2019         init_timer(&device->request_timer);
2020         device->resync_timer.function = resync_timer_fn;
2021         device->resync_timer.data = (unsigned long) device;
2022         device->md_sync_timer.function = md_sync_timer_fn;
2023         device->md_sync_timer.data = (unsigned long) device;
2024         device->start_resync_timer.function = start_resync_timer_fn;
2025         device->start_resync_timer.data = (unsigned long) device;
2026         device->request_timer.function = request_timer_fn;
2027         device->request_timer.data = (unsigned long) device;
2028
2029         init_waitqueue_head(&device->misc_wait);
2030         init_waitqueue_head(&device->state_wait);
2031         init_waitqueue_head(&device->ee_wait);
2032         init_waitqueue_head(&device->al_wait);
2033         init_waitqueue_head(&device->seq_wait);
2034
2035         device->resync_wenr = LC_FREE;
2036         device->peer_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
2037         device->local_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
2038 }
2039
2040 void drbd_device_cleanup(struct drbd_device *device)
2041 {
2042         int i;
2043         if (first_peer_device(device)->connection->receiver.t_state != NONE)
2044                 drbd_err(device, "ASSERT FAILED: receiver t_state == %d expected 0.\n",
2045                                 first_peer_device(device)->connection->receiver.t_state);
2046
2047         device->al_writ_cnt  =
2048         device->bm_writ_cnt  =
2049         device->read_cnt     =
2050         device->recv_cnt     =
2051         device->send_cnt     =
2052         device->writ_cnt     =
2053         device->p_size       =
2054         device->rs_start     =
2055         device->rs_total     =
2056         device->rs_failed    = 0;
2057         device->rs_last_events = 0;
2058         device->rs_last_sect_ev = 0;
2059         for (i = 0; i < DRBD_SYNC_MARKS; i++) {
2060                 device->rs_mark_left[i] = 0;
2061                 device->rs_mark_time[i] = 0;
2062         }
2063         D_ASSERT(device, first_peer_device(device)->connection->net_conf == NULL);
2064
2065         drbd_set_my_capacity(device, 0);
2066         if (device->bitmap) {
2067                 /* maybe never allocated. */
2068                 drbd_bm_resize(device, 0, 1);
2069                 drbd_bm_cleanup(device);
2070         }
2071
2072         drbd_backing_dev_free(device, device->ldev);
2073         device->ldev = NULL;
2074
2075         clear_bit(AL_SUSPENDED, &device->flags);
2076
2077         D_ASSERT(device, list_empty(&device->active_ee));
2078         D_ASSERT(device, list_empty(&device->sync_ee));
2079         D_ASSERT(device, list_empty(&device->done_ee));
2080         D_ASSERT(device, list_empty(&device->read_ee));
2081         D_ASSERT(device, list_empty(&device->net_ee));
2082         D_ASSERT(device, list_empty(&device->resync_reads));
2083         D_ASSERT(device, list_empty(&first_peer_device(device)->connection->sender_work.q));
2084         D_ASSERT(device, list_empty(&device->resync_work.list));
2085         D_ASSERT(device, list_empty(&device->unplug_work.list));
2086
2087         drbd_set_defaults(device);
2088 }
2089
2090
2091 static void drbd_destroy_mempools(void)
2092 {
2093         struct page *page;
2094
2095         while (drbd_pp_pool) {
2096                 page = drbd_pp_pool;
2097                 drbd_pp_pool = (struct page *)page_private(page);
2098                 __free_page(page);
2099                 drbd_pp_vacant--;
2100         }
2101
2102         /* D_ASSERT(device, atomic_read(&drbd_pp_vacant)==0); */
2103
2104         if (drbd_md_io_bio_set)
2105                 bioset_free(drbd_md_io_bio_set);
2106         if (drbd_md_io_page_pool)
2107                 mempool_destroy(drbd_md_io_page_pool);
2108         if (drbd_ee_mempool)
2109                 mempool_destroy(drbd_ee_mempool);
2110         if (drbd_request_mempool)
2111                 mempool_destroy(drbd_request_mempool);
2112         if (drbd_ee_cache)
2113                 kmem_cache_destroy(drbd_ee_cache);
2114         if (drbd_request_cache)
2115                 kmem_cache_destroy(drbd_request_cache);
2116         if (drbd_bm_ext_cache)
2117                 kmem_cache_destroy(drbd_bm_ext_cache);
2118         if (drbd_al_ext_cache)
2119                 kmem_cache_destroy(drbd_al_ext_cache);
2120
2121         drbd_md_io_bio_set   = NULL;
2122         drbd_md_io_page_pool = NULL;
2123         drbd_ee_mempool      = NULL;
2124         drbd_request_mempool = NULL;
2125         drbd_ee_cache        = NULL;
2126         drbd_request_cache   = NULL;
2127         drbd_bm_ext_cache    = NULL;
2128         drbd_al_ext_cache    = NULL;
2129
2130         return;
2131 }
2132
2133 static int drbd_create_mempools(void)
2134 {
2135         struct page *page;
2136         const int number = (DRBD_MAX_BIO_SIZE/PAGE_SIZE) * minor_count;
2137         int i;
2138
2139         /* prepare our caches and mempools */
2140         drbd_request_mempool = NULL;
2141         drbd_ee_cache        = NULL;
2142         drbd_request_cache   = NULL;
2143         drbd_bm_ext_cache    = NULL;
2144         drbd_al_ext_cache    = NULL;
2145         drbd_pp_pool         = NULL;
2146         drbd_md_io_page_pool = NULL;
2147         drbd_md_io_bio_set   = NULL;
2148
2149         /* caches */
2150         drbd_request_cache = kmem_cache_create(
2151                 "drbd_req", sizeof(struct drbd_request), 0, 0, NULL);
2152         if (drbd_request_cache == NULL)
2153                 goto Enomem;
2154
2155         drbd_ee_cache = kmem_cache_create(
2156                 "drbd_ee", sizeof(struct drbd_peer_request), 0, 0, NULL);
2157         if (drbd_ee_cache == NULL)
2158                 goto Enomem;
2159
2160         drbd_bm_ext_cache = kmem_cache_create(
2161                 "drbd_bm", sizeof(struct bm_extent), 0, 0, NULL);
2162         if (drbd_bm_ext_cache == NULL)
2163                 goto Enomem;
2164
2165         drbd_al_ext_cache = kmem_cache_create(
2166                 "drbd_al", sizeof(struct lc_element), 0, 0, NULL);
2167         if (drbd_al_ext_cache == NULL)
2168                 goto Enomem;
2169
2170         /* mempools */
2171         drbd_md_io_bio_set = bioset_create(DRBD_MIN_POOL_PAGES, 0);
2172         if (drbd_md_io_bio_set == NULL)
2173                 goto Enomem;
2174
2175         drbd_md_io_page_pool = mempool_create_page_pool(DRBD_MIN_POOL_PAGES, 0);
2176         if (drbd_md_io_page_pool == NULL)
2177                 goto Enomem;
2178
2179         drbd_request_mempool = mempool_create_slab_pool(number,
2180                 drbd_request_cache);
2181         if (drbd_request_mempool == NULL)
2182                 goto Enomem;
2183
2184         drbd_ee_mempool = mempool_create_slab_pool(number, drbd_ee_cache);
2185         if (drbd_ee_mempool == NULL)
2186                 goto Enomem;
2187
2188         /* drbd's page pool */
2189         spin_lock_init(&drbd_pp_lock);
2190
2191         for (i = 0; i < number; i++) {
2192                 page = alloc_page(GFP_HIGHUSER);
2193                 if (!page)
2194                         goto Enomem;
2195                 set_page_private(page, (unsigned long)drbd_pp_pool);
2196                 drbd_pp_pool = page;
2197         }
2198         drbd_pp_vacant = number;
2199
2200         return 0;
2201
2202 Enomem:
2203         drbd_destroy_mempools(); /* in case we allocated some */
2204         return -ENOMEM;
2205 }
2206
2207 static void drbd_release_all_peer_reqs(struct drbd_device *device)
2208 {
2209         int rr;
2210
2211         rr = drbd_free_peer_reqs(device, &device->active_ee);
2212         if (rr)
2213                 drbd_err(device, "%d EEs in active list found!\n", rr);
2214
2215         rr = drbd_free_peer_reqs(device, &device->sync_ee);
2216         if (rr)
2217                 drbd_err(device, "%d EEs in sync list found!\n", rr);
2218
2219         rr = drbd_free_peer_reqs(device, &device->read_ee);
2220         if (rr)
2221                 drbd_err(device, "%d EEs in read list found!\n", rr);
2222
2223         rr = drbd_free_peer_reqs(device, &device->done_ee);
2224         if (rr)
2225                 drbd_err(device, "%d EEs in done list found!\n", rr);
2226
2227         rr = drbd_free_peer_reqs(device, &device->net_ee);
2228         if (rr)
2229                 drbd_err(device, "%d EEs in net list found!\n", rr);
2230 }
2231
2232 /* caution. no locking. */
2233 void drbd_destroy_device(struct kref *kref)
2234 {
2235         struct drbd_device *device = container_of(kref, struct drbd_device, kref);
2236         struct drbd_resource *resource = device->resource;
2237         struct drbd_peer_device *peer_device, *tmp_peer_device;
2238
2239         del_timer_sync(&device->request_timer);
2240
2241         /* paranoia asserts */
2242         D_ASSERT(device, device->open_cnt == 0);
2243         /* end paranoia asserts */
2244
2245         /* cleanup stuff that may have been allocated during
2246          * device (re-)configuration or state changes */
2247
2248         if (device->this_bdev)
2249                 bdput(device->this_bdev);
2250
2251         drbd_backing_dev_free(device, device->ldev);
2252         device->ldev = NULL;
2253
2254         drbd_release_all_peer_reqs(device);
2255
2256         lc_destroy(device->act_log);
2257         lc_destroy(device->resync);
2258
2259         kfree(device->p_uuid);
2260         /* device->p_uuid = NULL; */
2261
2262         if (device->bitmap) /* should no longer be there. */
2263                 drbd_bm_cleanup(device);
2264         __free_page(device->md_io.page);
2265         put_disk(device->vdisk);
2266         blk_cleanup_queue(device->rq_queue);
2267         kfree(device->rs_plan_s);
2268
2269         /* not for_each_connection(connection, resource):
2270          * those may have been cleaned up and disassociated already.
2271          */
2272         for_each_peer_device_safe(peer_device, tmp_peer_device, device) {
2273                 kref_put(&peer_device->connection->kref, drbd_destroy_connection);
2274                 kfree(peer_device);
2275         }
2276         memset(device, 0xfd, sizeof(*device));
2277         kfree(device);
2278         kref_put(&resource->kref, drbd_destroy_resource);
2279 }
2280
2281 /* One global retry thread, if we need to push back some bio and have it
2282  * reinserted through our make request function.
2283  */
2284 static struct retry_worker {
2285         struct workqueue_struct *wq;
2286         struct work_struct worker;
2287
2288         spinlock_t lock;
2289         struct list_head writes;
2290 } retry;
2291
2292 static void do_retry(struct work_struct *ws)
2293 {
2294         struct retry_worker *retry = container_of(ws, struct retry_worker, worker);
2295         LIST_HEAD(writes);
2296         struct drbd_request *req, *tmp;
2297
2298         spin_lock_irq(&retry->lock);
2299         list_splice_init(&retry->writes, &writes);
2300         spin_unlock_irq(&retry->lock);
2301
2302         list_for_each_entry_safe(req, tmp, &writes, tl_requests) {
2303                 struct drbd_device *device = req->device;
2304                 struct bio *bio = req->master_bio;
2305                 unsigned long start_jif = req->start_jif;
2306                 bool expected;
2307
2308                 expected =
2309                         expect(atomic_read(&req->completion_ref) == 0) &&
2310                         expect(req->rq_state & RQ_POSTPONED) &&
2311                         expect((req->rq_state & RQ_LOCAL_PENDING) == 0 ||
2312                                 (req->rq_state & RQ_LOCAL_ABORTED) != 0);
2313
2314                 if (!expected)
2315                         drbd_err(device, "req=%p completion_ref=%d rq_state=%x\n",
2316                                 req, atomic_read(&req->completion_ref),
2317                                 req->rq_state);
2318
2319                 /* We still need to put one kref associated with the
2320                  * "completion_ref" going zero in the code path that queued it
2321                  * here.  The request object may still be referenced by a
2322                  * frozen local req->private_bio, in case we force-detached.
2323                  */
2324                 kref_put(&req->kref, drbd_req_destroy);
2325
2326                 /* A single suspended or otherwise blocking device may stall
2327                  * all others as well.  Fortunately, this code path is to
2328                  * recover from a situation that "should not happen":
2329                  * concurrent writes in multi-primary setup.
2330                  * In a "normal" lifecycle, this workqueue is supposed to be
2331                  * destroyed without ever doing anything.
2332                  * If it turns out to be an issue anyways, we can do per
2333                  * resource (replication group) or per device (minor) retry
2334                  * workqueues instead.
2335                  */
2336
2337                 /* We are not just doing generic_make_request(),
2338                  * as we want to keep the start_time information. */
2339                 inc_ap_bio(device);
2340                 __drbd_make_request(device, bio, start_jif);
2341         }
2342 }
2343
2344 /* called via drbd_req_put_completion_ref(),
2345  * holds resource->req_lock */
2346 void drbd_restart_request(struct drbd_request *req)
2347 {
2348         unsigned long flags;
2349         spin_lock_irqsave(&retry.lock, flags);
2350         list_move_tail(&req->tl_requests, &retry.writes);
2351         spin_unlock_irqrestore(&retry.lock, flags);
2352
2353         /* Drop the extra reference that would otherwise
2354          * have been dropped by complete_master_bio.
2355          * do_retry() needs to grab a new one. */
2356         dec_ap_bio(req->device);
2357
2358         queue_work(retry.wq, &retry.worker);
2359 }
2360
2361 void drbd_destroy_resource(struct kref *kref)
2362 {
2363         struct drbd_resource *resource =
2364                 container_of(kref, struct drbd_resource, kref);
2365
2366         idr_destroy(&resource->devices);
2367         free_cpumask_var(resource->cpu_mask);
2368         kfree(resource->name);
2369         memset(resource, 0xf2, sizeof(*resource));
2370         kfree(resource);
2371 }
2372
2373 void drbd_free_resource(struct drbd_resource *resource)
2374 {
2375         struct drbd_connection *connection, *tmp;
2376
2377         for_each_connection_safe(connection, tmp, resource) {
2378                 list_del(&connection->connections);
2379                 drbd_debugfs_connection_cleanup(connection);
2380                 kref_put(&connection->kref, drbd_destroy_connection);
2381         }
2382         drbd_debugfs_resource_cleanup(resource);
2383         kref_put(&resource->kref, drbd_destroy_resource);
2384 }
2385
2386 static void drbd_cleanup(void)
2387 {
2388         unsigned int i;
2389         struct drbd_device *device;
2390         struct drbd_resource *resource, *tmp;
2391
2392         /* first remove proc,
2393          * drbdsetup uses it's presence to detect
2394          * whether DRBD is loaded.
2395          * If we would get stuck in proc removal,
2396          * but have netlink already deregistered,
2397          * some drbdsetup commands may wait forever
2398          * for an answer.
2399          */
2400         if (drbd_proc)
2401                 remove_proc_entry("drbd", NULL);
2402
2403         if (retry.wq)
2404                 destroy_workqueue(retry.wq);
2405
2406         drbd_genl_unregister();
2407         drbd_debugfs_cleanup();
2408
2409         idr_for_each_entry(&drbd_devices, device, i)
2410                 drbd_delete_device(device);
2411
2412         /* not _rcu since, no other updater anymore. Genl already unregistered */
2413         for_each_resource_safe(resource, tmp, &drbd_resources) {
2414                 list_del(&resource->resources);
2415                 drbd_free_resource(resource);
2416         }
2417
2418         drbd_destroy_mempools();
2419         unregister_blkdev(DRBD_MAJOR, "drbd");
2420
2421         idr_destroy(&drbd_devices);
2422
2423         pr_info("module cleanup done.\n");
2424 }
2425
2426 /**
2427  * drbd_congested() - Callback for the flusher thread
2428  * @congested_data:     User data
2429  * @bdi_bits:           Bits the BDI flusher thread is currently interested in
2430  *
2431  * Returns 1<<WB_async_congested and/or 1<<WB_sync_congested if we are congested.
2432  */
2433 static int drbd_congested(void *congested_data, int bdi_bits)
2434 {
2435         struct drbd_device *device = congested_data;
2436         struct request_queue *q;
2437         char reason = '-';
2438         int r = 0;
2439
2440         if (!may_inc_ap_bio(device)) {
2441                 /* DRBD has frozen IO */
2442                 r = bdi_bits;
2443                 reason = 'd';
2444                 goto out;
2445         }
2446
2447         if (test_bit(CALLBACK_PENDING, &first_peer_device(device)->connection->flags)) {
2448                 r |= (1 << WB_async_congested);
2449                 /* Without good local data, we would need to read from remote,
2450                  * and that would need the worker thread as well, which is
2451                  * currently blocked waiting for that usermode helper to
2452                  * finish.
2453                  */
2454                 if (!get_ldev_if_state(device, D_UP_TO_DATE))
2455                         r |= (1 << WB_sync_congested);
2456                 else
2457                         put_ldev(device);
2458                 r &= bdi_bits;
2459                 reason = 'c';
2460                 goto out;
2461         }
2462
2463         if (get_ldev(device)) {
2464                 q = bdev_get_queue(device->ldev->backing_bdev);
2465                 r = bdi_congested(q->backing_dev_info, bdi_bits);
2466                 put_ldev(device);
2467                 if (r)
2468                         reason = 'b';
2469         }
2470
2471         if (bdi_bits & (1 << WB_async_congested) &&
2472             test_bit(NET_CONGESTED, &first_peer_device(device)->connection->flags)) {
2473                 r |= (1 << WB_async_congested);
2474                 reason = reason == 'b' ? 'a' : 'n';
2475         }
2476
2477 out:
2478         device->congestion_reason = reason;
2479         return r;
2480 }
2481
2482 static void drbd_init_workqueue(struct drbd_work_queue* wq)
2483 {
2484         spin_lock_init(&wq->q_lock);
2485         INIT_LIST_HEAD(&wq->q);
2486         init_waitqueue_head(&wq->q_wait);
2487 }
2488
2489 struct completion_work {
2490         struct drbd_work w;
2491         struct completion done;
2492 };
2493
2494 static int w_complete(struct drbd_work *w, int cancel)
2495 {
2496         struct completion_work *completion_work =
2497                 container_of(w, struct completion_work, w);
2498
2499         complete(&completion_work->done);
2500         return 0;
2501 }
2502
2503 void drbd_flush_workqueue(struct drbd_work_queue *work_queue)
2504 {
2505         struct completion_work completion_work;
2506
2507         completion_work.w.cb = w_complete;
2508         init_completion(&completion_work.done);
2509         drbd_queue_work(work_queue, &completion_work.w);
2510         wait_for_completion(&completion_work.done);
2511 }
2512
2513 struct drbd_resource *drbd_find_resource(const char *name)
2514 {
2515         struct drbd_resource *resource;
2516
2517         if (!name || !name[0])
2518                 return NULL;
2519
2520         rcu_read_lock();
2521         for_each_resource_rcu(resource, &drbd_resources) {
2522                 if (!strcmp(resource->name, name)) {
2523                         kref_get(&resource->kref);
2524                         goto found;
2525                 }
2526         }
2527         resource = NULL;
2528 found:
2529         rcu_read_unlock();
2530         return resource;
2531 }
2532
2533 struct drbd_connection *conn_get_by_addrs(void *my_addr, int my_addr_len,
2534                                      void *peer_addr, int peer_addr_len)
2535 {
2536         struct drbd_resource *resource;
2537         struct drbd_connection *connection;
2538
2539         rcu_read_lock();
2540         for_each_resource_rcu(resource, &drbd_resources) {
2541                 for_each_connection_rcu(connection, resource) {
2542                         if (connection->my_addr_len == my_addr_len &&
2543                             connection->peer_addr_len == peer_addr_len &&
2544                             !memcmp(&connection->my_addr, my_addr, my_addr_len) &&
2545                             !memcmp(&connection->peer_addr, peer_addr, peer_addr_len)) {
2546                                 kref_get(&connection->kref);
2547                                 goto found;
2548                         }
2549                 }
2550         }
2551         connection = NULL;
2552 found:
2553         rcu_read_unlock();
2554         return connection;
2555 }
2556
2557 static int drbd_alloc_socket(struct drbd_socket *socket)
2558 {
2559         socket->rbuf = (void *) __get_free_page(GFP_KERNEL);
2560         if (!socket->rbuf)
2561                 return -ENOMEM;
2562         socket->sbuf = (void *) __get_free_page(GFP_KERNEL);
2563         if (!socket->sbuf)
2564                 return -ENOMEM;
2565         return 0;
2566 }
2567
2568 static void drbd_free_socket(struct drbd_socket *socket)
2569 {
2570         free_page((unsigned long) socket->sbuf);
2571         free_page((unsigned long) socket->rbuf);
2572 }
2573
2574 void conn_free_crypto(struct drbd_connection *connection)
2575 {
2576         drbd_free_sock(connection);
2577
2578         crypto_free_ahash(connection->csums_tfm);
2579         crypto_free_ahash(connection->verify_tfm);
2580         crypto_free_shash(connection->cram_hmac_tfm);
2581         crypto_free_ahash(connection->integrity_tfm);
2582         crypto_free_ahash(connection->peer_integrity_tfm);
2583         kfree(connection->int_dig_in);
2584         kfree(connection->int_dig_vv);
2585
2586         connection->csums_tfm = NULL;
2587         connection->verify_tfm = NULL;
2588         connection->cram_hmac_tfm = NULL;
2589         connection->integrity_tfm = NULL;
2590         connection->peer_integrity_tfm = NULL;
2591         connection->int_dig_in = NULL;
2592         connection->int_dig_vv = NULL;
2593 }
2594
2595 int set_resource_options(struct drbd_resource *resource, struct res_opts *res_opts)
2596 {
2597         struct drbd_connection *connection;
2598         cpumask_var_t new_cpu_mask;
2599         int err;
2600
2601         if (!zalloc_cpumask_var(&new_cpu_mask, GFP_KERNEL))
2602                 return -ENOMEM;
2603
2604         /* silently ignore cpu mask on UP kernel */
2605         if (nr_cpu_ids > 1 && res_opts->cpu_mask[0] != 0) {
2606                 err = bitmap_parse(res_opts->cpu_mask, DRBD_CPU_MASK_SIZE,
2607                                    cpumask_bits(new_cpu_mask), nr_cpu_ids);
2608                 if (err == -EOVERFLOW) {
2609                         /* So what. mask it out. */
2610                         cpumask_var_t tmp_cpu_mask;
2611                         if (zalloc_cpumask_var(&tmp_cpu_mask, GFP_KERNEL)) {
2612                                 cpumask_setall(tmp_cpu_mask);
2613                                 cpumask_and(new_cpu_mask, new_cpu_mask, tmp_cpu_mask);
2614                                 drbd_warn(resource, "Overflow in bitmap_parse(%.12s%s), truncating to %u bits\n",
2615                                         res_opts->cpu_mask,
2616                                         strlen(res_opts->cpu_mask) > 12 ? "..." : "",
2617                                         nr_cpu_ids);
2618                                 free_cpumask_var(tmp_cpu_mask);
2619                                 err = 0;
2620                         }
2621                 }
2622                 if (err) {
2623                         drbd_warn(resource, "bitmap_parse() failed with %d\n", err);
2624                         /* retcode = ERR_CPU_MASK_PARSE; */
2625                         goto fail;
2626                 }
2627         }
2628         resource->res_opts = *res_opts;
2629         if (cpumask_empty(new_cpu_mask))
2630                 drbd_calc_cpu_mask(&new_cpu_mask);
2631         if (!cpumask_equal(resource->cpu_mask, new_cpu_mask)) {
2632                 cpumask_copy(resource->cpu_mask, new_cpu_mask);
2633                 for_each_connection_rcu(connection, resource) {
2634                         connection->receiver.reset_cpu_mask = 1;
2635                         connection->ack_receiver.reset_cpu_mask = 1;
2636                         connection->worker.reset_cpu_mask = 1;
2637                 }
2638         }
2639         err = 0;
2640
2641 fail:
2642         free_cpumask_var(new_cpu_mask);
2643         return err;
2644
2645 }
2646
2647 struct drbd_resource *drbd_create_resource(const char *name)
2648 {
2649         struct drbd_resource *resource;
2650
2651         resource = kzalloc(sizeof(struct drbd_resource), GFP_KERNEL);
2652         if (!resource)
2653                 goto fail;
2654         resource->name = kstrdup(name, GFP_KERNEL);
2655         if (!resource->name)
2656                 goto fail_free_resource;
2657         if (!zalloc_cpumask_var(&resource->cpu_mask, GFP_KERNEL))
2658                 goto fail_free_name;
2659         kref_init(&resource->kref);
2660         idr_init(&resource->devices);
2661         INIT_LIST_HEAD(&resource->connections);
2662         resource->write_ordering = WO_BDEV_FLUSH;
2663         list_add_tail_rcu(&resource->resources, &drbd_resources);
2664         mutex_init(&resource->conf_update);
2665         mutex_init(&resource->adm_mutex);
2666         spin_lock_init(&resource->req_lock);
2667         drbd_debugfs_resource_add(resource);
2668         return resource;
2669
2670 fail_free_name:
2671         kfree(resource->name);
2672 fail_free_resource:
2673         kfree(resource);
2674 fail:
2675         return NULL;
2676 }
2677
2678 /* caller must be under adm_mutex */
2679 struct drbd_connection *conn_create(const char *name, struct res_opts *res_opts)
2680 {
2681         struct drbd_resource *resource;
2682         struct drbd_connection *connection;
2683
2684         connection = kzalloc(sizeof(struct drbd_connection), GFP_KERNEL);
2685         if (!connection)
2686                 return NULL;
2687
2688         if (drbd_alloc_socket(&connection->data))
2689                 goto fail;
2690         if (drbd_alloc_socket(&connection->meta))
2691                 goto fail;
2692
2693         connection->current_epoch = kzalloc(sizeof(struct drbd_epoch), GFP_KERNEL);
2694         if (!connection->current_epoch)
2695                 goto fail;
2696
2697         INIT_LIST_HEAD(&connection->transfer_log);
2698
2699         INIT_LIST_HEAD(&connection->current_epoch->list);
2700         connection->epochs = 1;
2701         spin_lock_init(&connection->epoch_lock);
2702
2703         connection->send.seen_any_write_yet = false;
2704         connection->send.current_epoch_nr = 0;
2705         connection->send.current_epoch_writes = 0;
2706
2707         resource = drbd_create_resource(name);
2708         if (!resource)
2709                 goto fail;
2710
2711         connection->cstate = C_STANDALONE;
2712         mutex_init(&connection->cstate_mutex);
2713         init_waitqueue_head(&connection->ping_wait);
2714         idr_init(&connection->peer_devices);
2715
2716         drbd_init_workqueue(&connection->sender_work);
2717         mutex_init(&connection->data.mutex);
2718         mutex_init(&connection->meta.mutex);
2719
2720         drbd_thread_init(resource, &connection->receiver, drbd_receiver, "receiver");
2721         connection->receiver.connection = connection;
2722         drbd_thread_init(resource, &connection->worker, drbd_worker, "worker");
2723         connection->worker.connection = connection;
2724         drbd_thread_init(resource, &connection->ack_receiver, drbd_ack_receiver, "ack_recv");
2725         connection->ack_receiver.connection = connection;
2726
2727         kref_init(&connection->kref);
2728
2729         connection->resource = resource;
2730
2731         if (set_resource_options(resource, res_opts))
2732                 goto fail_resource;
2733
2734         kref_get(&resource->kref);
2735         list_add_tail_rcu(&connection->connections, &resource->connections);
2736         drbd_debugfs_connection_add(connection);
2737         return connection;
2738
2739 fail_resource:
2740         list_del(&resource->resources);
2741         drbd_free_resource(resource);
2742 fail:
2743         kfree(connection->current_epoch);
2744         drbd_free_socket(&connection->meta);
2745         drbd_free_socket(&connection->data);
2746         kfree(connection);
2747         return NULL;
2748 }
2749
2750 void drbd_destroy_connection(struct kref *kref)
2751 {
2752         struct drbd_connection *connection = container_of(kref, struct drbd_connection, kref);
2753         struct drbd_resource *resource = connection->resource;
2754
2755         if (atomic_read(&connection->current_epoch->epoch_size) !=  0)
2756                 drbd_err(connection, "epoch_size:%d\n", atomic_read(&connection->current_epoch->epoch_size));
2757         kfree(connection->current_epoch);
2758
2759         idr_destroy(&connection->peer_devices);
2760
2761         drbd_free_socket(&connection->meta);
2762         drbd_free_socket(&connection->data);
2763         kfree(connection->int_dig_in);
2764         kfree(connection->int_dig_vv);
2765         memset(connection, 0xfc, sizeof(*connection));
2766         kfree(connection);
2767         kref_put(&resource->kref, drbd_destroy_resource);
2768 }
2769
2770 static int init_submitter(struct drbd_device *device)
2771 {
2772         /* opencoded create_singlethread_workqueue(),
2773          * to be able to say "drbd%d", ..., minor */
2774         device->submit.wq =
2775                 alloc_ordered_workqueue("drbd%u_submit", WQ_MEM_RECLAIM, device->minor);
2776         if (!device->submit.wq)
2777                 return -ENOMEM;
2778
2779         INIT_WORK(&device->submit.worker, do_submit);
2780         INIT_LIST_HEAD(&device->submit.writes);
2781         return 0;
2782 }
2783
2784 enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsigned int minor)
2785 {
2786         struct drbd_resource *resource = adm_ctx->resource;
2787         struct drbd_connection *connection;
2788         struct drbd_device *device;
2789         struct drbd_peer_device *peer_device, *tmp_peer_device;
2790         struct gendisk *disk;
2791         struct request_queue *q;
2792         int id;
2793         int vnr = adm_ctx->volume;
2794         enum drbd_ret_code err = ERR_NOMEM;
2795
2796         device = minor_to_device(minor);
2797         if (device)
2798                 return ERR_MINOR_OR_VOLUME_EXISTS;
2799
2800         /* GFP_KERNEL, we are outside of all write-out paths */
2801         device = kzalloc(sizeof(struct drbd_device), GFP_KERNEL);
2802         if (!device)
2803                 return ERR_NOMEM;
2804         kref_init(&device->kref);
2805
2806         kref_get(&resource->kref);
2807         device->resource = resource;
2808         device->minor = minor;
2809         device->vnr = vnr;
2810
2811         drbd_init_set_defaults(device);
2812
2813         q = blk_alloc_queue(GFP_KERNEL);
2814         if (!q)
2815                 goto out_no_q;
2816         device->rq_queue = q;
2817         q->queuedata   = device;
2818
2819         disk = alloc_disk(1);
2820         if (!disk)
2821                 goto out_no_disk;
2822         device->vdisk = disk;
2823
2824         set_disk_ro(disk, true);
2825
2826         disk->queue = q;
2827         disk->major = DRBD_MAJOR;
2828         disk->first_minor = minor;
2829         disk->fops = &drbd_ops;
2830         sprintf(disk->disk_name, "drbd%d", minor);
2831         disk->private_data = device;
2832
2833         device->this_bdev = bdget(MKDEV(DRBD_MAJOR, minor));
2834         /* we have no partitions. we contain only ourselves. */
2835         device->this_bdev->bd_contains = device->this_bdev;
2836
2837         q->backing_dev_info->congested_fn = drbd_congested;
2838         q->backing_dev_info->congested_data = device;
2839
2840         blk_queue_make_request(q, drbd_make_request);
2841         blk_queue_write_cache(q, true, true);
2842         /* Setting the max_hw_sectors to an odd value of 8kibyte here
2843            This triggers a max_bio_size message upon first attach or connect */
2844         blk_queue_max_hw_sectors(q, DRBD_MAX_BIO_SIZE_SAFE >> 8);
2845         blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
2846         q->queue_lock = &resource->req_lock;
2847
2848         device->md_io.page = alloc_page(GFP_KERNEL);
2849         if (!device->md_io.page)
2850                 goto out_no_io_page;
2851
2852         if (drbd_bm_init(device))
2853                 goto out_no_bitmap;
2854         device->read_requests = RB_ROOT;
2855         device->write_requests = RB_ROOT;
2856
2857         id = idr_alloc(&drbd_devices, device, minor, minor + 1, GFP_KERNEL);
2858         if (id < 0) {
2859                 if (id == -ENOSPC)
2860                         err = ERR_MINOR_OR_VOLUME_EXISTS;
2861                 goto out_no_minor_idr;
2862         }
2863         kref_get(&device->kref);
2864
2865         id = idr_alloc(&resource->devices, device, vnr, vnr + 1, GFP_KERNEL);
2866         if (id < 0) {
2867                 if (id == -ENOSPC)
2868                         err = ERR_MINOR_OR_VOLUME_EXISTS;
2869                 goto out_idr_remove_minor;
2870         }
2871         kref_get(&device->kref);
2872
2873         INIT_LIST_HEAD(&device->peer_devices);
2874         INIT_LIST_HEAD(&device->pending_bitmap_io);
2875         for_each_connection(connection, resource) {
2876                 peer_device = kzalloc(sizeof(struct drbd_peer_device), GFP_KERNEL);
2877                 if (!peer_device)
2878                         goto out_idr_remove_from_resource;
2879                 peer_device->connection = connection;
2880                 peer_device->device = device;
2881
2882                 list_add(&peer_device->peer_devices, &device->peer_devices);
2883                 kref_get(&device->kref);
2884
2885                 id = idr_alloc(&connection->peer_devices, peer_device, vnr, vnr + 1, GFP_KERNEL);
2886                 if (id < 0) {
2887                         if (id == -ENOSPC)
2888                                 err = ERR_INVALID_REQUEST;
2889                         goto out_idr_remove_from_resource;
2890                 }
2891                 kref_get(&connection->kref);
2892                 INIT_WORK(&peer_device->send_acks_work, drbd_send_acks_wf);
2893         }
2894
2895         if (init_submitter(device)) {
2896                 err = ERR_NOMEM;
2897                 goto out_idr_remove_vol;
2898         }
2899
2900         add_disk(disk);
2901
2902         /* inherit the connection state */
2903         device->state.conn = first_connection(resource)->cstate;
2904         if (device->state.conn == C_WF_REPORT_PARAMS) {
2905                 for_each_peer_device(peer_device, device)
2906                         drbd_connected(peer_device);
2907         }
2908         /* move to create_peer_device() */
2909         for_each_peer_device(peer_device, device)
2910                 drbd_debugfs_peer_device_add(peer_device);
2911         drbd_debugfs_device_add(device);
2912         return NO_ERROR;
2913
2914 out_idr_remove_vol:
2915         idr_remove(&connection->peer_devices, vnr);
2916 out_idr_remove_from_resource:
2917         for_each_connection(connection, resource) {
2918                 peer_device = idr_remove(&connection->peer_devices, vnr);
2919                 if (peer_device)
2920                         kref_put(&connection->kref, drbd_destroy_connection);
2921         }
2922         for_each_peer_device_safe(peer_device, tmp_peer_device, device) {
2923                 list_del(&peer_device->peer_devices);
2924                 kfree(peer_device);
2925         }
2926         idr_remove(&resource->devices, vnr);
2927 out_idr_remove_minor:
2928         idr_remove(&drbd_devices, minor);
2929         synchronize_rcu();
2930 out_no_minor_idr:
2931         drbd_bm_cleanup(device);
2932 out_no_bitmap:
2933         __free_page(device->md_io.page);
2934 out_no_io_page:
2935         put_disk(disk);
2936 out_no_disk:
2937         blk_cleanup_queue(q);
2938 out_no_q:
2939         kref_put(&resource->kref, drbd_destroy_resource);
2940         kfree(device);
2941         return err;
2942 }
2943
2944 void drbd_delete_device(struct drbd_device *device)
2945 {
2946         struct drbd_resource *resource = device->resource;
2947         struct drbd_connection *connection;
2948         struct drbd_peer_device *peer_device;
2949
2950         /* move to free_peer_device() */
2951         for_each_peer_device(peer_device, device)
2952                 drbd_debugfs_peer_device_cleanup(peer_device);
2953         drbd_debugfs_device_cleanup(device);
2954         for_each_connection(connection, resource) {
2955                 idr_remove(&connection->peer_devices, device->vnr);
2956                 kref_put(&device->kref, drbd_destroy_device);
2957         }
2958         idr_remove(&resource->devices, device->vnr);
2959         kref_put(&device->kref, drbd_destroy_device);
2960         idr_remove(&drbd_devices, device_to_minor(device));
2961         kref_put(&device->kref, drbd_destroy_device);
2962         del_gendisk(device->vdisk);
2963         synchronize_rcu();
2964         kref_put(&device->kref, drbd_destroy_device);
2965 }
2966
2967 static int __init drbd_init(void)
2968 {
2969         int err;
2970
2971         if (minor_count < DRBD_MINOR_COUNT_MIN || minor_count > DRBD_MINOR_COUNT_MAX) {
2972                 pr_err("invalid minor_count (%d)\n", minor_count);
2973 #ifdef MODULE
2974                 return -EINVAL;
2975 #else
2976                 minor_count = DRBD_MINOR_COUNT_DEF;
2977 #endif
2978         }
2979
2980         err = register_blkdev(DRBD_MAJOR, "drbd");
2981         if (err) {
2982                 pr_err("unable to register block device major %d\n",
2983                        DRBD_MAJOR);
2984                 return err;
2985         }
2986
2987         /*
2988          * allocate all necessary structs
2989          */
2990         init_waitqueue_head(&drbd_pp_wait);
2991
2992         drbd_proc = NULL; /* play safe for drbd_cleanup */
2993         idr_init(&drbd_devices);
2994
2995         mutex_init(&resources_mutex);
2996         INIT_LIST_HEAD(&drbd_resources);
2997
2998         err = drbd_genl_register();
2999         if (err) {
3000                 pr_err("unable to register generic netlink family\n");
3001                 goto fail;
3002         }
3003
3004         err = drbd_create_mempools();
3005         if (err)
3006                 goto fail;
3007
3008         err = -ENOMEM;
3009         drbd_proc = proc_create_data("drbd", S_IFREG | S_IRUGO , NULL, &drbd_proc_fops, NULL);
3010         if (!drbd_proc) {
3011                 pr_err("unable to register proc file\n");
3012                 goto fail;
3013         }
3014
3015         retry.wq = create_singlethread_workqueue("drbd-reissue");
3016         if (!retry.wq) {
3017                 pr_err("unable to create retry workqueue\n");
3018                 goto fail;
3019         }
3020         INIT_WORK(&retry.worker, do_retry);
3021         spin_lock_init(&retry.lock);
3022         INIT_LIST_HEAD(&retry.writes);
3023
3024         if (drbd_debugfs_init())
3025                 pr_notice("failed to initialize debugfs -- will not be available\n");
3026
3027         pr_info("initialized. "
3028                "Version: " REL_VERSION " (api:%d/proto:%d-%d)\n",
3029                API_VERSION, PRO_VERSION_MIN, PRO_VERSION_MAX);
3030         pr_info("%s\n", drbd_buildtag());
3031         pr_info("registered as block device major %d\n", DRBD_MAJOR);
3032         return 0; /* Success! */
3033
3034 fail:
3035         drbd_cleanup();
3036         if (err == -ENOMEM)
3037                 pr_err("ran out of memory\n");
3038         else
3039                 pr_err("initialization failure\n");
3040         return err;
3041 }
3042
3043 static void drbd_free_one_sock(struct drbd_socket *ds)
3044 {
3045         struct socket *s;
3046         mutex_lock(&ds->mutex);
3047         s = ds->socket;
3048         ds->socket = NULL;
3049         mutex_unlock(&ds->mutex);
3050         if (s) {
3051                 /* so debugfs does not need to mutex_lock() */
3052                 synchronize_rcu();
3053                 kernel_sock_shutdown(s, SHUT_RDWR);
3054                 sock_release(s);
3055         }
3056 }
3057
3058 void drbd_free_sock(struct drbd_connection *connection)
3059 {
3060         if (connection->data.socket)
3061                 drbd_free_one_sock(&connection->data);
3062         if (connection->meta.socket)
3063                 drbd_free_one_sock(&connection->meta);
3064 }
3065
3066 /* meta data management */
3067
3068 void conn_md_sync(struct drbd_connection *connection)
3069 {
3070         struct drbd_peer_device *peer_device;
3071         int vnr;
3072
3073         rcu_read_lock();
3074         idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
3075                 struct drbd_device *device = peer_device->device;
3076
3077                 kref_get(&device->kref);
3078                 rcu_read_unlock();
3079                 drbd_md_sync(device);
3080                 kref_put(&device->kref, drbd_destroy_device);
3081                 rcu_read_lock();
3082         }
3083         rcu_read_unlock();
3084 }
3085
3086 /* aligned 4kByte */
3087 struct meta_data_on_disk {
3088         u64 la_size_sect;      /* last agreed size. */
3089         u64 uuid[UI_SIZE];   /* UUIDs. */
3090         u64 device_uuid;
3091         u64 reserved_u64_1;
3092         u32 flags;             /* MDF */
3093         u32 magic;
3094         u32 md_size_sect;
3095         u32 al_offset;         /* offset to this block */
3096         u32 al_nr_extents;     /* important for restoring the AL (userspace) */
3097               /* `-- act_log->nr_elements <-- ldev->dc.al_extents */
3098         u32 bm_offset;         /* offset to the bitmap, from here */
3099         u32 bm_bytes_per_bit;  /* BM_BLOCK_SIZE */
3100         u32 la_peer_max_bio_size;   /* last peer max_bio_size */
3101
3102         /* see al_tr_number_to_on_disk_sector() */
3103         u32 al_stripes;
3104         u32 al_stripe_size_4k;
3105
3106         u8 reserved_u8[4096 - (7*8 + 10*4)];
3107 } __packed;
3108
3109
3110
3111 void drbd_md_write(struct drbd_device *device, void *b)
3112 {
3113         struct meta_data_on_disk *buffer = b;
3114         sector_t sector;
3115         int i;
3116
3117         memset(buffer, 0, sizeof(*buffer));
3118
3119         buffer->la_size_sect = cpu_to_be64(drbd_get_capacity(device->this_bdev));
3120         for (i = UI_CURRENT; i < UI_SIZE; i++)
3121                 buffer->uuid[i] = cpu_to_be64(device->ldev->md.uuid[i]);
3122         buffer->flags = cpu_to_be32(device->ldev->md.flags);
3123         buffer->magic = cpu_to_be32(DRBD_MD_MAGIC_84_UNCLEAN);
3124
3125         buffer->md_size_sect  = cpu_to_be32(device->ldev->md.md_size_sect);
3126         buffer->al_offset     = cpu_to_be32(device->ldev->md.al_offset);
3127         buffer->al_nr_extents = cpu_to_be32(device->act_log->nr_elements);
3128         buffer->bm_bytes_per_bit = cpu_to_be32(BM_BLOCK_SIZE);
3129         buffer->device_uuid = cpu_to_be64(device->ldev->md.device_uuid);
3130
3131         buffer->bm_offset = cpu_to_be32(device->ldev->md.bm_offset);
3132         buffer->la_peer_max_bio_size = cpu_to_be32(device->peer_max_bio_size);
3133
3134         buffer->al_stripes = cpu_to_be32(device->ldev->md.al_stripes);
3135         buffer->al_stripe_size_4k = cpu_to_be32(device->ldev->md.al_stripe_size_4k);
3136
3137         D_ASSERT(device, drbd_md_ss(device->ldev) == device->ldev->md.md_offset);
3138         sector = device->ldev->md.md_offset;
3139
3140         if (drbd_md_sync_page_io(device, device->ldev, sector, REQ_OP_WRITE)) {
3141                 /* this was a try anyways ... */
3142                 drbd_err(device, "meta data update failed!\n");
3143                 drbd_chk_io_error(device, 1, DRBD_META_IO_ERROR);
3144         }
3145 }
3146
3147 /**
3148  * drbd_md_sync() - Writes the meta data super block if the MD_DIRTY flag bit is set
3149  * @device:     DRBD device.
3150  */
3151 void drbd_md_sync(struct drbd_device *device)
3152 {
3153         struct meta_data_on_disk *buffer;
3154
3155         /* Don't accidentally change the DRBD meta data layout. */
3156         BUILD_BUG_ON(UI_SIZE != 4);
3157         BUILD_BUG_ON(sizeof(struct meta_data_on_disk) != 4096);
3158
3159         del_timer(&device->md_sync_timer);
3160         /* timer may be rearmed by drbd_md_mark_dirty() now. */
3161         if (!test_and_clear_bit(MD_DIRTY, &device->flags))
3162                 return;
3163
3164         /* We use here D_FAILED and not D_ATTACHING because we try to write
3165          * metadata even if we detach due to a disk failure! */
3166         if (!get_ldev_if_state(device, D_FAILED))
3167                 return;
3168
3169         buffer = drbd_md_get_buffer(device, __func__);
3170         if (!buffer)
3171                 goto out;
3172
3173         drbd_md_write(device, buffer);
3174
3175         /* Update device->ldev->md.la_size_sect,
3176          * since we updated it on metadata. */
3177         device->ldev->md.la_size_sect = drbd_get_capacity(device->this_bdev);
3178
3179         drbd_md_put_buffer(device);
3180 out:
3181         put_ldev(device);
3182 }
3183
3184 static int check_activity_log_stripe_size(struct drbd_device *device,
3185                 struct meta_data_on_disk *on_disk,
3186                 struct drbd_md *in_core)
3187 {
3188         u32 al_stripes = be32_to_cpu(on_disk->al_stripes);
3189         u32 al_stripe_size_4k = be32_to_cpu(on_disk->al_stripe_size_4k);
3190         u64 al_size_4k;
3191
3192         /* both not set: default to old fixed size activity log */
3193         if (al_stripes == 0 && al_stripe_size_4k == 0) {
3194                 al_stripes = 1;
3195                 al_stripe_size_4k = MD_32kB_SECT/8;
3196         }
3197
3198         /* some paranoia plausibility checks */
3199
3200         /* we need both values to be set */
3201         if (al_stripes == 0 || al_stripe_size_4k == 0)
3202                 goto err;
3203
3204         al_size_4k = (u64)al_stripes * al_stripe_size_4k;
3205
3206         /* Upper limit of activity log area, to avoid potential overflow
3207          * problems in al_tr_number_to_on_disk_sector(). As right now, more
3208          * than 72 * 4k blocks total only increases the amount of history,
3209          * limiting this arbitrarily to 16 GB is not a real limitation ;-)  */
3210         if (al_size_4k > (16 * 1024 * 1024/4))
3211                 goto err;
3212
3213         /* Lower limit: we need at least 8 transaction slots (32kB)
3214          * to not break existing setups */
3215         if (al_size_4k < MD_32kB_SECT/8)
3216                 goto err;
3217
3218         in_core->al_stripe_size_4k = al_stripe_size_4k;
3219         in_core->al_stripes = al_stripes;
3220         in_core->al_size_4k = al_size_4k;
3221
3222         return 0;
3223 err:
3224         drbd_err(device, "invalid activity log striping: al_stripes=%u, al_stripe_size_4k=%u\n",
3225                         al_stripes, al_stripe_size_4k);
3226         return -EINVAL;
3227 }
3228
3229 static int check_offsets_and_sizes(struct drbd_device *device, struct drbd_backing_dev *bdev)
3230 {
3231         sector_t capacity = drbd_get_capacity(bdev->md_bdev);
3232         struct drbd_md *in_core = &bdev->md;
3233         s32 on_disk_al_sect;
3234         s32 on_disk_bm_sect;
3235
3236         /* The on-disk size of the activity log, calculated from offsets, and
3237          * the size of the activity log calculated from the stripe settings,
3238          * should match.
3239          * Though we could relax this a bit: it is ok, if the striped activity log
3240          * fits in the available on-disk activity log size.
3241          * Right now, that would break how resize is implemented.
3242          * TODO: make drbd_determine_dev_size() (and the drbdmeta tool) aware
3243          * of possible unused padding space in the on disk layout. */
3244         if (in_core->al_offset < 0) {
3245                 if (in_core->bm_offset > in_core->al_offset)
3246                         goto err;
3247                 on_disk_al_sect = -in_core->al_offset;
3248                 on_disk_bm_sect = in_core->al_offset - in_core->bm_offset;
3249         } else {
3250                 if (in_core->al_offset != MD_4kB_SECT)
3251                         goto err;
3252                 if (in_core->bm_offset < in_core->al_offset + in_core->al_size_4k * MD_4kB_SECT)
3253                         goto err;
3254
3255                 on_disk_al_sect = in_core->bm_offset - MD_4kB_SECT;
3256                 on_disk_bm_sect = in_core->md_size_sect - in_core->bm_offset;
3257         }
3258
3259         /* old fixed size meta data is exactly that: fixed. */
3260         if (in_core->meta_dev_idx >= 0) {
3261                 if (in_core->md_size_sect != MD_128MB_SECT
3262                 ||  in_core->al_offset != MD_4kB_SECT
3263                 ||  in_core->bm_offset != MD_4kB_SECT + MD_32kB_SECT
3264                 ||  in_core->al_stripes != 1
3265                 ||  in_core->al_stripe_size_4k != MD_32kB_SECT/8)
3266                         goto err;
3267         }
3268
3269         if (capacity < in_core->md_size_sect)
3270                 goto err;
3271         if (capacity - in_core->md_size_sect < drbd_md_first_sector(bdev))
3272                 goto err;
3273
3274         /* should be aligned, and at least 32k */
3275         if ((on_disk_al_sect & 7) || (on_disk_al_sect < MD_32kB_SECT))
3276                 goto err;
3277
3278         /* should fit (for now: exactly) into the available on-disk space;
3279          * overflow prevention is in check_activity_log_stripe_size() above. */
3280         if (on_disk_al_sect != in_core->al_size_4k * MD_4kB_SECT)
3281                 goto err;
3282
3283         /* again, should be aligned */
3284         if (in_core->bm_offset & 7)
3285                 goto err;
3286
3287         /* FIXME check for device grow with flex external meta data? */
3288
3289         /* can the available bitmap space cover the last agreed device size? */
3290         if (on_disk_bm_sect < (in_core->la_size_sect+7)/MD_4kB_SECT/8/512)
3291                 goto err;
3292
3293         return 0;
3294
3295 err:
3296         drbd_err(device, "meta data offsets don't make sense: idx=%d "
3297                         "al_s=%u, al_sz4k=%u, al_offset=%d, bm_offset=%d, "
3298                         "md_size_sect=%u, la_size=%llu, md_capacity=%llu\n",
3299                         in_core->meta_dev_idx,
3300                         in_core->al_stripes, in_core->al_stripe_size_4k,
3301                         in_core->al_offset, in_core->bm_offset, in_core->md_size_sect,
3302                         (unsigned long long)in_core->la_size_sect,
3303                         (unsigned long long)capacity);
3304
3305         return -EINVAL;
3306 }
3307
3308
3309 /**
3310  * drbd_md_read() - Reads in the meta data super block
3311  * @device:     DRBD device.
3312  * @bdev:       Device from which the meta data should be read in.
3313  *
3314  * Return NO_ERROR on success, and an enum drbd_ret_code in case
3315  * something goes wrong.
3316  *
3317  * Called exactly once during drbd_adm_attach(), while still being D_DISKLESS,
3318  * even before @bdev is assigned to @device->ldev.
3319  */
3320 int drbd_md_read(struct drbd_device *device, struct drbd_backing_dev *bdev)
3321 {
3322         struct meta_data_on_disk *buffer;
3323         u32 magic, flags;
3324         int i, rv = NO_ERROR;
3325
3326         if (device->state.disk != D_DISKLESS)
3327                 return ERR_DISK_CONFIGURED;
3328
3329         buffer = drbd_md_get_buffer(device, __func__);
3330         if (!buffer)
3331                 return ERR_NOMEM;
3332
3333         /* First, figure out where our meta data superblock is located,
3334          * and read it. */
3335         bdev->md.meta_dev_idx = bdev->disk_conf->meta_dev_idx;
3336         bdev->md.md_offset = drbd_md_ss(bdev);
3337         /* Even for (flexible or indexed) external meta data,
3338          * initially restrict us to the 4k superblock for now.
3339          * Affects the paranoia out-of-range access check in drbd_md_sync_page_io(). */
3340         bdev->md.md_size_sect = 8;
3341
3342         if (drbd_md_sync_page_io(device, bdev, bdev->md.md_offset,
3343                                  REQ_OP_READ)) {
3344                 /* NOTE: can't do normal error processing here as this is
3345                    called BEFORE disk is attached */
3346                 drbd_err(device, "Error while reading metadata.\n");
3347                 rv = ERR_IO_MD_DISK;
3348                 goto err;
3349         }
3350
3351         magic = be32_to_cpu(buffer->magic);
3352         flags = be32_to_cpu(buffer->flags);
3353         if (magic == DRBD_MD_MAGIC_84_UNCLEAN ||
3354             (magic == DRBD_MD_MAGIC_08 && !(flags & MDF_AL_CLEAN))) {
3355                         /* btw: that's Activity Log clean, not "all" clean. */
3356                 drbd_err(device, "Found unclean meta data. Did you \"drbdadm apply-al\"?\n");
3357                 rv = ERR_MD_UNCLEAN;
3358                 goto err;
3359         }
3360
3361         rv = ERR_MD_INVALID;
3362         if (magic != DRBD_MD_MAGIC_08) {
3363                 if (magic == DRBD_MD_MAGIC_07)
3364                         drbd_err(device, "Found old (0.7) meta data magic. Did you \"drbdadm create-md\"?\n");
3365                 else
3366                         drbd_err(device, "Meta data magic not found. Did you \"drbdadm create-md\"?\n");
3367                 goto err;
3368         }
3369
3370         if (be32_to_cpu(buffer->bm_bytes_per_bit) != BM_BLOCK_SIZE) {
3371                 drbd_err(device, "unexpected bm_bytes_per_bit: %u (expected %u)\n",
3372                     be32_to_cpu(buffer->bm_bytes_per_bit), BM_BLOCK_SIZE);
3373                 goto err;
3374         }
3375
3376
3377         /* convert to in_core endian */
3378         bdev->md.la_size_sect = be64_to_cpu(buffer->la_size_sect);
3379         for (i = UI_CURRENT; i < UI_SIZE; i++)
3380                 bdev->md.uuid[i] = be64_to_cpu(buffer->uuid[i]);
3381         bdev->md.flags = be32_to_cpu(buffer->flags);
3382         bdev->md.device_uuid = be64_to_cpu(buffer->device_uuid);
3383
3384         bdev->md.md_size_sect = be32_to_cpu(buffer->md_size_sect);
3385         bdev->md.al_offset = be32_to_cpu(buffer->al_offset);
3386         bdev->md.bm_offset = be32_to_cpu(buffer->bm_offset);
3387
3388         if (check_activity_log_stripe_size(device, buffer, &bdev->md))
3389                 goto err;
3390         if (check_offsets_and_sizes(device, bdev))
3391                 goto err;
3392
3393         if (be32_to_cpu(buffer->bm_offset) != bdev->md.bm_offset) {
3394                 drbd_err(device, "unexpected bm_offset: %d (expected %d)\n",
3395                     be32_to_cpu(buffer->bm_offset), bdev->md.bm_offset);
3396                 goto err;
3397         }
3398         if (be32_to_cpu(buffer->md_size_sect) != bdev->md.md_size_sect) {
3399                 drbd_err(device, "unexpected md_size: %u (expected %u)\n",
3400                     be32_to_cpu(buffer->md_size_sect), bdev->md.md_size_sect);
3401                 goto err;
3402         }
3403
3404         rv = NO_ERROR;
3405
3406         spin_lock_irq(&device->resource->req_lock);
3407         if (device->state.conn < C_CONNECTED) {
3408                 unsigned int peer;
3409                 peer = be32_to_cpu(buffer->la_peer_max_bio_size);
3410                 peer = max(peer, DRBD_MAX_BIO_SIZE_SAFE);
3411                 device->peer_max_bio_size = peer;
3412         }
3413         spin_unlock_irq(&device->resource->req_lock);
3414
3415  err:
3416         drbd_md_put_buffer(device);
3417
3418         return rv;
3419 }
3420
3421 /**
3422  * drbd_md_mark_dirty() - Mark meta data super block as dirty
3423  * @device:     DRBD device.
3424  *
3425  * Call this function if you change anything that should be written to
3426  * the meta-data super block. This function sets MD_DIRTY, and starts a
3427  * timer that ensures that within five seconds you have to call drbd_md_sync().
3428  */
3429 #ifdef DEBUG
3430 void drbd_md_mark_dirty_(struct drbd_device *device, unsigned int line, const char *func)
3431 {
3432         if (!test_and_set_bit(MD_DIRTY, &device->flags)) {
3433                 mod_timer(&device->md_sync_timer, jiffies + HZ);
3434                 device->last_md_mark_dirty.line = line;
3435                 device->last_md_mark_dirty.func = func;
3436         }
3437 }
3438 #else
3439 void drbd_md_mark_dirty(struct drbd_device *device)
3440 {
3441         if (!test_and_set_bit(MD_DIRTY, &device->flags))
3442                 mod_timer(&device->md_sync_timer, jiffies + 5*HZ);
3443 }
3444 #endif
3445
3446 void drbd_uuid_move_history(struct drbd_device *device) __must_hold(local)
3447 {
3448         int i;
3449
3450         for (i = UI_HISTORY_START; i < UI_HISTORY_END; i++)
3451                 device->ldev->md.uuid[i+1] = device->ldev->md.uuid[i];
3452 }
3453
3454 void __drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local)
3455 {
3456         if (idx == UI_CURRENT) {
3457                 if (device->state.role == R_PRIMARY)
3458                         val |= 1;
3459                 else
3460                         val &= ~((u64)1);
3461
3462                 drbd_set_ed_uuid(device, val);
3463         }
3464
3465         device->ldev->md.uuid[idx] = val;
3466         drbd_md_mark_dirty(device);
3467 }
3468
3469 void _drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local)
3470 {
3471         unsigned long flags;
3472         spin_lock_irqsave(&device->ldev->md.uuid_lock, flags);
3473         __drbd_uuid_set(device, idx, val);
3474         spin_unlock_irqrestore(&device->ldev->md.uuid_lock, flags);
3475 }
3476
3477 void drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local)
3478 {
3479         unsigned long flags;
3480         spin_lock_irqsave(&device->ldev->md.uuid_lock, flags);
3481         if (device->ldev->md.uuid[idx]) {
3482                 drbd_uuid_move_history(device);
3483                 device->ldev->md.uuid[UI_HISTORY_START] = device->ldev->md.uuid[idx];
3484         }
3485         __drbd_uuid_set(device, idx, val);
3486         spin_unlock_irqrestore(&device->ldev->md.uuid_lock, flags);
3487 }
3488
3489 /**
3490  * drbd_uuid_new_current() - Creates a new current UUID
3491  * @device:     DRBD device.
3492  *
3493  * Creates a new current UUID, and rotates the old current UUID into
3494  * the bitmap slot. Causes an incremental resync upon next connect.
3495  */
3496 void drbd_uuid_new_current(struct drbd_device *device) __must_hold(local)
3497 {
3498         u64 val;
3499         unsigned long long bm_uuid;
3500
3501         get_random_bytes(&val, sizeof(u64));
3502
3503         spin_lock_irq(&device->ldev->md.uuid_lock);
3504         bm_uuid = device->ldev->md.uuid[UI_BITMAP];
3505
3506         if (bm_uuid)
3507                 drbd_warn(device, "bm UUID was already set: %llX\n", bm_uuid);
3508
3509         device->ldev->md.uuid[UI_BITMAP] = device->ldev->md.uuid[UI_CURRENT];
3510         __drbd_uuid_set(device, UI_CURRENT, val);
3511         spin_unlock_irq(&device->ldev->md.uuid_lock);
3512
3513         drbd_print_uuids(device, "new current UUID");
3514         /* get it to stable storage _now_ */
3515         drbd_md_sync(device);
3516 }
3517
3518 void drbd_uuid_set_bm(struct drbd_device *device, u64 val) __must_hold(local)
3519 {
3520         unsigned long flags;
3521         if (device->ldev->md.uuid[UI_BITMAP] == 0 && val == 0)
3522                 return;
3523
3524         spin_lock_irqsave(&device->ldev->md.uuid_lock, flags);
3525         if (val == 0) {
3526                 drbd_uuid_move_history(device);
3527                 device->ldev->md.uuid[UI_HISTORY_START] = device->ldev->md.uuid[UI_BITMAP];
3528                 device->ldev->md.uuid[UI_BITMAP] = 0;
3529         } else {
3530                 unsigned long long bm_uuid = device->ldev->md.uuid[UI_BITMAP];
3531                 if (bm_uuid)
3532                         drbd_warn(device, "bm UUID was already set: %llX\n", bm_uuid);
3533
3534                 device->ldev->md.uuid[UI_BITMAP] = val & ~((u64)1);
3535         }
3536         spin_unlock_irqrestore(&device->ldev->md.uuid_lock, flags);
3537
3538         drbd_md_mark_dirty(device);
3539 }
3540
3541 /**
3542  * drbd_bmio_set_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
3543  * @device:     DRBD device.
3544  *
3545  * Sets all bits in the bitmap and writes the whole bitmap to stable storage.
3546  */
3547 int drbd_bmio_set_n_write(struct drbd_device *device) __must_hold(local)
3548 {
3549         int rv = -EIO;
3550
3551         drbd_md_set_flag(device, MDF_FULL_SYNC);
3552         drbd_md_sync(device);
3553         drbd_bm_set_all(device);
3554
3555         rv = drbd_bm_write(device);
3556
3557         if (!rv) {
3558                 drbd_md_clear_flag(device, MDF_FULL_SYNC);
3559                 drbd_md_sync(device);
3560         }
3561
3562         return rv;
3563 }
3564
3565 /**
3566  * drbd_bmio_clear_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
3567  * @device:     DRBD device.
3568  *
3569  * Clears all bits in the bitmap and writes the whole bitmap to stable storage.
3570  */
3571 int drbd_bmio_clear_n_write(struct drbd_device *device) __must_hold(local)
3572 {
3573         drbd_resume_al(device);
3574         drbd_bm_clear_all(device);
3575         return drbd_bm_write(device);
3576 }
3577
3578 static int w_bitmap_io(struct drbd_work *w, int unused)
3579 {
3580         struct drbd_device *device =
3581                 container_of(w, struct drbd_device, bm_io_work.w);
3582         struct bm_io_work *work = &device->bm_io_work;
3583         int rv = -EIO;
3584
3585         if (work->flags != BM_LOCKED_CHANGE_ALLOWED) {
3586                 int cnt = atomic_read(&device->ap_bio_cnt);
3587                 if (cnt)
3588                         drbd_err(device, "FIXME: ap_bio_cnt %d, expected 0; queued for '%s'\n",
3589                                         cnt, work->why);
3590         }
3591
3592         if (get_ldev(device)) {
3593                 drbd_bm_lock(device, work->why, work->flags);
3594                 rv = work->io_fn(device);
3595                 drbd_bm_unlock(device);
3596                 put_ldev(device);
3597         }
3598
3599         clear_bit_unlock(BITMAP_IO, &device->flags);
3600         wake_up(&device->misc_wait);
3601
3602         if (work->done)
3603                 work->done(device, rv);
3604
3605         clear_bit(BITMAP_IO_QUEUED, &device->flags);
3606         work->why = NULL;
3607         work->flags = 0;
3608
3609         return 0;
3610 }
3611
3612 /**
3613  * drbd_queue_bitmap_io() - Queues an IO operation on the whole bitmap
3614  * @device:     DRBD device.
3615  * @io_fn:      IO callback to be called when bitmap IO is possible
3616  * @done:       callback to be called after the bitmap IO was performed
3617  * @why:        Descriptive text of the reason for doing the IO
3618  *
3619  * While IO on the bitmap happens we freeze application IO thus we ensure
3620  * that drbd_set_out_of_sync() can not be called. This function MAY ONLY be
3621  * called from worker context. It MUST NOT be used while a previous such
3622  * work is still pending!
3623  *
3624  * Its worker function encloses the call of io_fn() by get_ldev() and
3625  * put_ldev().
3626  */
3627 void drbd_queue_bitmap_io(struct drbd_device *device,
3628                           int (*io_fn)(struct drbd_device *),
3629                           void (*done)(struct drbd_device *, int),
3630                           char *why, enum bm_flag flags)
3631 {
3632         D_ASSERT(device, current == first_peer_device(device)->connection->worker.task);
3633
3634         D_ASSERT(device, !test_bit(BITMAP_IO_QUEUED, &device->flags));
3635         D_ASSERT(device, !test_bit(BITMAP_IO, &device->flags));
3636         D_ASSERT(device, list_empty(&device->bm_io_work.w.list));
3637         if (device->bm_io_work.why)
3638                 drbd_err(device, "FIXME going to queue '%s' but '%s' still pending?\n",
3639                         why, device->bm_io_work.why);
3640
3641         device->bm_io_work.io_fn = io_fn;
3642         device->bm_io_work.done = done;
3643         device->bm_io_work.why = why;
3644         device->bm_io_work.flags = flags;
3645
3646         spin_lock_irq(&device->resource->req_lock);
3647         set_bit(BITMAP_IO, &device->flags);
3648         /* don't wait for pending application IO if the caller indicates that
3649          * application IO does not conflict anyways. */
3650         if (flags == BM_LOCKED_CHANGE_ALLOWED || atomic_read(&device->ap_bio_cnt) == 0) {
3651                 if (!test_and_set_bit(BITMAP_IO_QUEUED, &device->flags))
3652                         drbd_queue_work(&first_peer_device(device)->connection->sender_work,
3653                                         &device->bm_io_work.w);
3654         }
3655         spin_unlock_irq(&device->resource->req_lock);
3656 }
3657
3658 /**
3659  * drbd_bitmap_io() -  Does an IO operation on the whole bitmap
3660  * @device:     DRBD device.
3661  * @io_fn:      IO callback to be called when bitmap IO is possible
3662  * @why:        Descriptive text of the reason for doing the IO
3663  *
3664  * freezes application IO while that the actual IO operations runs. This
3665  * functions MAY NOT be called from worker context.
3666  */
3667 int drbd_bitmap_io(struct drbd_device *device, int (*io_fn)(struct drbd_device *),
3668                 char *why, enum bm_flag flags)
3669 {
3670         /* Only suspend io, if some operation is supposed to be locked out */
3671         const bool do_suspend_io = flags & (BM_DONT_CLEAR|BM_DONT_SET|BM_DONT_TEST);
3672         int rv;
3673
3674         D_ASSERT(device, current != first_peer_device(device)->connection->worker.task);
3675
3676         if (do_suspend_io)
3677                 drbd_suspend_io(device);
3678
3679         drbd_bm_lock(device, why, flags);
3680         rv = io_fn(device);
3681         drbd_bm_unlock(device);
3682
3683         if (do_suspend_io)
3684                 drbd_resume_io(device);
3685
3686         return rv;
3687 }
3688
3689 void drbd_md_set_flag(struct drbd_device *device, int flag) __must_hold(local)
3690 {
3691         if ((device->ldev->md.flags & flag) != flag) {
3692                 drbd_md_mark_dirty(device);
3693                 device->ldev->md.flags |= flag;
3694         }
3695 }
3696
3697 void drbd_md_clear_flag(struct drbd_device *device, int flag) __must_hold(local)
3698 {
3699         if ((device->ldev->md.flags & flag) != 0) {
3700                 drbd_md_mark_dirty(device);
3701                 device->ldev->md.flags &= ~flag;
3702         }
3703 }
3704 int drbd_md_test_flag(struct drbd_backing_dev *bdev, int flag)
3705 {
3706         return (bdev->md.flags & flag) != 0;
3707 }
3708
3709 static void md_sync_timer_fn(unsigned long data)
3710 {
3711         struct drbd_device *device = (struct drbd_device *) data;
3712         drbd_device_post_work(device, MD_SYNC);
3713 }
3714
3715 const char *cmdname(enum drbd_packet cmd)
3716 {
3717         /* THINK may need to become several global tables
3718          * when we want to support more than
3719          * one PRO_VERSION */
3720         static const char *cmdnames[] = {
3721                 [P_DATA]                = "Data",
3722                 [P_WSAME]               = "WriteSame",
3723                 [P_TRIM]                = "Trim",
3724                 [P_DATA_REPLY]          = "DataReply",
3725                 [P_RS_DATA_REPLY]       = "RSDataReply",
3726                 [P_BARRIER]             = "Barrier",
3727                 [P_BITMAP]              = "ReportBitMap",
3728                 [P_BECOME_SYNC_TARGET]  = "BecomeSyncTarget",
3729                 [P_BECOME_SYNC_SOURCE]  = "BecomeSyncSource",
3730                 [P_UNPLUG_REMOTE]       = "UnplugRemote",
3731                 [P_DATA_REQUEST]        = "DataRequest",
3732                 [P_RS_DATA_REQUEST]     = "RSDataRequest",
3733                 [P_SYNC_PARAM]          = "SyncParam",
3734                 [P_SYNC_PARAM89]        = "SyncParam89",
3735                 [P_PROTOCOL]            = "ReportProtocol",
3736                 [P_UUIDS]               = "ReportUUIDs",
3737                 [P_SIZES]               = "ReportSizes",
3738                 [P_STATE]               = "ReportState",
3739                 [P_SYNC_UUID]           = "ReportSyncUUID",
3740                 [P_AUTH_CHALLENGE]      = "AuthChallenge",
3741                 [P_AUTH_RESPONSE]       = "AuthResponse",
3742                 [P_PING]                = "Ping",
3743                 [P_PING_ACK]            = "PingAck",
3744                 [P_RECV_ACK]            = "RecvAck",
3745                 [P_WRITE_ACK]           = "WriteAck",
3746                 [P_RS_WRITE_ACK]        = "RSWriteAck",
3747                 [P_SUPERSEDED]          = "Superseded",
3748                 [P_NEG_ACK]             = "NegAck",
3749                 [P_NEG_DREPLY]          = "NegDReply",
3750                 [P_NEG_RS_DREPLY]       = "NegRSDReply",
3751                 [P_BARRIER_ACK]         = "BarrierAck",
3752                 [P_STATE_CHG_REQ]       = "StateChgRequest",
3753                 [P_STATE_CHG_REPLY]     = "StateChgReply",
3754                 [P_OV_REQUEST]          = "OVRequest",
3755                 [P_OV_REPLY]            = "OVReply",
3756                 [P_OV_RESULT]           = "OVResult",
3757                 [P_CSUM_RS_REQUEST]     = "CsumRSRequest",
3758                 [P_RS_IS_IN_SYNC]       = "CsumRSIsInSync",
3759                 [P_COMPRESSED_BITMAP]   = "CBitmap",
3760                 [P_DELAY_PROBE]         = "DelayProbe",
3761                 [P_OUT_OF_SYNC]         = "OutOfSync",
3762                 [P_RETRY_WRITE]         = "RetryWrite",
3763                 [P_RS_CANCEL]           = "RSCancel",
3764                 [P_CONN_ST_CHG_REQ]     = "conn_st_chg_req",
3765                 [P_CONN_ST_CHG_REPLY]   = "conn_st_chg_reply",
3766                 [P_RETRY_WRITE]         = "retry_write",
3767                 [P_PROTOCOL_UPDATE]     = "protocol_update",
3768                 [P_RS_THIN_REQ]         = "rs_thin_req",
3769                 [P_RS_DEALLOCATED]      = "rs_deallocated",
3770
3771                 /* enum drbd_packet, but not commands - obsoleted flags:
3772                  *      P_MAY_IGNORE
3773                  *      P_MAX_OPT_CMD
3774                  */
3775         };
3776
3777         /* too big for the array: 0xfffX */
3778         if (cmd == P_INITIAL_META)
3779                 return "InitialMeta";
3780         if (cmd == P_INITIAL_DATA)
3781                 return "InitialData";
3782         if (cmd == P_CONNECTION_FEATURES)
3783                 return "ConnectionFeatures";
3784         if (cmd >= ARRAY_SIZE(cmdnames))
3785                 return "Unknown";
3786         return cmdnames[cmd];
3787 }
3788
3789 /**
3790  * drbd_wait_misc  -  wait for a request to make progress
3791  * @device:     device associated with the request
3792  * @i:          the struct drbd_interval embedded in struct drbd_request or
3793  *              struct drbd_peer_request
3794  */
3795 int drbd_wait_misc(struct drbd_device *device, struct drbd_interval *i)
3796 {
3797         struct net_conf *nc;
3798         DEFINE_WAIT(wait);
3799         long timeout;
3800
3801         rcu_read_lock();
3802         nc = rcu_dereference(first_peer_device(device)->connection->net_conf);
3803         if (!nc) {
3804                 rcu_read_unlock();
3805                 return -ETIMEDOUT;
3806         }
3807         timeout = nc->ko_count ? nc->timeout * HZ / 10 * nc->ko_count : MAX_SCHEDULE_TIMEOUT;
3808         rcu_read_unlock();
3809
3810         /* Indicate to wake up device->misc_wait on progress.  */
3811         i->waiting = true;
3812         prepare_to_wait(&device->misc_wait, &wait, TASK_INTERRUPTIBLE);
3813         spin_unlock_irq(&device->resource->req_lock);
3814         timeout = schedule_timeout(timeout);
3815         finish_wait(&device->misc_wait, &wait);
3816         spin_lock_irq(&device->resource->req_lock);
3817         if (!timeout || device->state.conn < C_CONNECTED)
3818                 return -ETIMEDOUT;
3819         if (signal_pending(current))
3820                 return -ERESTARTSYS;
3821         return 0;
3822 }
3823
3824 void lock_all_resources(void)
3825 {
3826         struct drbd_resource *resource;
3827         int __maybe_unused i = 0;
3828
3829         mutex_lock(&resources_mutex);
3830         local_irq_disable();
3831         for_each_resource(resource, &drbd_resources)
3832                 spin_lock_nested(&resource->req_lock, i++);
3833 }
3834
3835 void unlock_all_resources(void)
3836 {
3837         struct drbd_resource *resource;
3838
3839         for_each_resource(resource, &drbd_resources)
3840                 spin_unlock(&resource->req_lock);
3841         local_irq_enable();
3842         mutex_unlock(&resources_mutex);
3843 }
3844
3845 #ifdef CONFIG_DRBD_FAULT_INJECTION
3846 /* Fault insertion support including random number generator shamelessly
3847  * stolen from kernel/rcutorture.c */
3848 struct fault_random_state {
3849         unsigned long state;
3850         unsigned long count;
3851 };
3852
3853 #define FAULT_RANDOM_MULT 39916801  /* prime */
3854 #define FAULT_RANDOM_ADD        479001701 /* prime */
3855 #define FAULT_RANDOM_REFRESH 10000
3856
3857 /*
3858  * Crude but fast random-number generator.  Uses a linear congruential
3859  * generator, with occasional help from get_random_bytes().
3860  */
3861 static unsigned long
3862 _drbd_fault_random(struct fault_random_state *rsp)
3863 {
3864         long refresh;
3865
3866         if (!rsp->count--) {
3867                 get_random_bytes(&refresh, sizeof(refresh));
3868                 rsp->state += refresh;
3869                 rsp->count = FAULT_RANDOM_REFRESH;
3870         }
3871         rsp->state = rsp->state * FAULT_RANDOM_MULT + FAULT_RANDOM_ADD;
3872         return swahw32(rsp->state);
3873 }
3874
3875 static char *
3876 _drbd_fault_str(unsigned int type) {
3877         static char *_faults[] = {
3878                 [DRBD_FAULT_MD_WR] = "Meta-data write",
3879                 [DRBD_FAULT_MD_RD] = "Meta-data read",
3880                 [DRBD_FAULT_RS_WR] = "Resync write",
3881                 [DRBD_FAULT_RS_RD] = "Resync read",
3882                 [DRBD_FAULT_DT_WR] = "Data write",
3883                 [DRBD_FAULT_DT_RD] = "Data read",
3884                 [DRBD_FAULT_DT_RA] = "Data read ahead",
3885                 [DRBD_FAULT_BM_ALLOC] = "BM allocation",
3886                 [DRBD_FAULT_AL_EE] = "EE allocation",
3887                 [DRBD_FAULT_RECEIVE] = "receive data corruption",
3888         };
3889
3890         return (type < DRBD_FAULT_MAX) ? _faults[type] : "**Unknown**";
3891 }
3892
3893 unsigned int
3894 _drbd_insert_fault(struct drbd_device *device, unsigned int type)
3895 {
3896         static struct fault_random_state rrs = {0, 0};
3897
3898         unsigned int ret = (
3899                 (fault_devs == 0 ||
3900                         ((1 << device_to_minor(device)) & fault_devs) != 0) &&
3901                 (((_drbd_fault_random(&rrs) % 100) + 1) <= fault_rate));
3902
3903         if (ret) {
3904                 fault_count++;
3905
3906                 if (__ratelimit(&drbd_ratelimit_state))
3907                         drbd_warn(device, "***Simulating %s failure\n",
3908                                 _drbd_fault_str(type));
3909         }
3910
3911         return ret;
3912 }
3913 #endif
3914
3915 const char *drbd_buildtag(void)
3916 {
3917         /* DRBD built from external sources has here a reference to the
3918            git hash of the source code. */
3919
3920         static char buildtag[38] = "\0uilt-in";
3921
3922         if (buildtag[0] == 0) {
3923 #ifdef MODULE
3924                 sprintf(buildtag, "srcversion: %-24s", THIS_MODULE->srcversion);
3925 #else
3926                 buildtag[0] = 'b';
3927 #endif
3928         }
3929
3930         return buildtag;
3931 }
3932
3933 module_init(drbd_init)
3934 module_exit(drbd_cleanup)
3935
3936 EXPORT_SYMBOL(drbd_conn_str);
3937 EXPORT_SYMBOL(drbd_role_str);
3938 EXPORT_SYMBOL(drbd_disk_str);
3939 EXPORT_SYMBOL(drbd_set_st_err_str);