drivers/block/drbd/drbd

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This source file includes following definitions.
bio_alloc_drbd
_get_ldev_if_state
tl_release
_tl_restart
tl_restart
tl_clear
tl_abort_disk_io
drbd_thread_setup
drbd_thread_init
drbd_thread_start
_drbd_thread_stop
conn_lowest_minor
drbd_calc_cpu_mask
drbd_thread_current_set_cpu
drbd_header_size
prepare_header80
prepare_header95
prepare_header100
prepare_header
__conn_prepare_command
conn_prepare_command
drbd_prepare_command
__send_command
__conn_send_command
conn_send_command
drbd_send_command
drbd_send_ping
drbd_send_ping_ack
drbd_send_sync_param
__drbd_send_protocol
drbd_send_protocol
_drbd_send_uuids
drbd_send_uuids
drbd_send_uuids_skip_initial_sync
drbd_print_uuids
drbd_gen_and_send_sync_uuid
assign_p_sizes_qlim
drbd_send_sizes
drbd_send_current_state
drbd_send_state
drbd_send_state_req
conn_send_state_req
drbd_send_sr_reply
conn_send_sr_reply
dcbp_set_code
dcbp_set_start
dcbp_set_pad_bits
fill_bitmap_rle_bits
send_bitmap_rle_or_plain
_drbd_send_bitmap
drbd_send_bitmap
drbd_send_b_ack
_drbd_send_ack
drbd_send_ack_dp
drbd_send_ack_rp
drbd_send_ack
drbd_send_ack_ex
drbd_send_rs_deallocated
drbd_send_drequest
drbd_send_drequest_csum
drbd_send_ov_request
we_should_drop_the_connection
drbd_update_congested
_drbd_no_send_page
_drbd_send_page
_drbd_send_bio
_drbd_send_zc_bio
_drbd_send_zc_ee
bio_flags_to_wire
drbd_send_dblock
drbd_send_block
drbd_send_out_of_sync
drbd_send
drbd_send_all
drbd_open
drbd_release
drbd_queue_unplug
drbd_set_defaults
drbd_init_set_defaults
_drbd_set_my_capacity
drbd_set_my_capacity
drbd_device_cleanup
drbd_destroy_mempools
drbd_create_mempools
drbd_release_all_peer_reqs
drbd_destroy_device
do_retry
drbd_restart_request
drbd_destroy_resource
drbd_free_resource
drbd_cleanup
drbd_congested
drbd_init_workqueue
w_complete
drbd_flush_workqueue
drbd_find_resource
conn_get_by_addrs
drbd_alloc_socket
drbd_free_socket
conn_free_crypto
set_resource_options
drbd_create_resource
conn_create
drbd_destroy_connection
init_submitter
drbd_create_device
drbd_delete_device
drbd_init
drbd_free_one_sock
drbd_free_sock
conn_md_sync
drbd_md_write
drbd_md_sync
check_activity_log_stripe_size
check_offsets_and_sizes
drbd_md_read
drbd_md_mark_dirty_
drbd_md_mark_dirty
drbd_uuid_move_history
__drbd_uuid_set
_drbd_uuid_set
drbd_uuid_set
drbd_uuid_new_current
drbd_uuid_set_bm
drbd_bmio_set_n_write
drbd_bmio_clear_n_write
w_bitmap_io
drbd_queue_bitmap_io
drbd_bitmap_io
drbd_md_set_flag
drbd_md_clear_flag
drbd_md_test_flag
md_sync_timer_fn
cmdname
drbd_wait_misc
lock_all_resources
unlock_all_resources
_drbd_fault_random
_drbd_fault_str
_drbd_insert_fault
drbd_buildtag
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3    drbd.c
   4 
   5    This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
   6 
   7    Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
   8    Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
   9    Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
  10 
  11    Thanks to Carter Burden, Bart Grantham and Gennadiy Nerubayev
  12    from Logicworks, Inc. for making SDP replication support possible.
  13 
  14 
  15  */
  16 
  17 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  18 
  19 #include <linux/module.h>
  20 #include <linux/jiffies.h>
  21 #include <linux/drbd.h>
  22 #include <linux/uaccess.h>
  23 #include <asm/types.h>
  24 #include <net/sock.h>
  25 #include <linux/ctype.h>
  26 #include <linux/mutex.h>
  27 #include <linux/fs.h>
  28 #include <linux/file.h>
  29 #include <linux/proc_fs.h>
  30 #include <linux/init.h>
  31 #include <linux/mm.h>
  32 #include <linux/memcontrol.h>
  33 #include <linux/mm_inline.h>
  34 #include <linux/slab.h>
  35 #include <linux/random.h>
  36 #include <linux/reboot.h>
  37 #include <linux/notifier.h>
  38 #include <linux/kthread.h>
  39 #include <linux/workqueue.h>
  40 #define __KERNEL_SYSCALLS__
  41 #include <linux/unistd.h>
  42 #include <linux/vmalloc.h>
  43 #include <linux/sched/signal.h>
  44 
  45 #include <linux/drbd_limits.h>
  46 #include "drbd_int.h"
  47 #include "drbd_protocol.h"
  48 #include "drbd_req.h" /* only for _req_mod in tl_release and tl_clear */
  49 #include "drbd_vli.h"
  50 #include "drbd_debugfs.h"
  51 
  52 static DEFINE_MUTEX(drbd_main_mutex);
  53 static int drbd_open(struct block_device *bdev, fmode_t mode);
  54 static void drbd_release(struct gendisk *gd, fmode_t mode);
  55 static void md_sync_timer_fn(struct timer_list *t);
  56 static int w_bitmap_io(struct drbd_work *w, int unused);
  57 
  58 MODULE_AUTHOR("Philipp Reisner <phil@linbit.com>, "
  59               "Lars Ellenberg <lars@linbit.com>");
  60 MODULE_DESCRIPTION("drbd - Distributed Replicated Block Device v" REL_VERSION);
  61 MODULE_VERSION(REL_VERSION);
  62 MODULE_LICENSE("GPL");
  63 MODULE_PARM_DESC(minor_count, "Approximate number of drbd devices ("
  64                  __stringify(DRBD_MINOR_COUNT_MIN) "-" __stringify(DRBD_MINOR_COUNT_MAX) ")");
  65 MODULE_ALIAS_BLOCKDEV_MAJOR(DRBD_MAJOR);
  66 
  67 #include <linux/moduleparam.h>
  68 /* thanks to these macros, if compiled into the kernel (not-module),
  69  * these become boot parameters (e.g., drbd.minor_count) */
  70 
  71 #ifdef CONFIG_DRBD_FAULT_INJECTION
  72 int drbd_enable_faults;
  73 int drbd_fault_rate;
  74 static int drbd_fault_count;
  75 static int drbd_fault_devs;
  76 /* bitmap of enabled faults */
  77 module_param_named(enable_faults, drbd_enable_faults, int, 0664);
  78 /* fault rate % value - applies to all enabled faults */
  79 module_param_named(fault_rate, drbd_fault_rate, int, 0664);
  80 /* count of faults inserted */
  81 module_param_named(fault_count, drbd_fault_count, int, 0664);
  82 /* bitmap of devices to insert faults on */
  83 module_param_named(fault_devs, drbd_fault_devs, int, 0644);
  84 #endif
  85 
  86 /* module parameters we can keep static */
  87 static bool drbd_allow_oos; /* allow_open_on_secondary */
  88 static bool drbd_disable_sendpage;
  89 MODULE_PARM_DESC(allow_oos, "DONT USE!");
  90 module_param_named(allow_oos, drbd_allow_oos, bool, 0);
  91 module_param_named(disable_sendpage, drbd_disable_sendpage, bool, 0644);
  92 
  93 /* module parameters we share */
  94 int drbd_proc_details; /* Detail level in proc drbd*/
  95 module_param_named(proc_details, drbd_proc_details, int, 0644);
  96 /* module parameters shared with defaults */
  97 unsigned int drbd_minor_count = DRBD_MINOR_COUNT_DEF;
  98 /* Module parameter for setting the user mode helper program
  99  * to run. Default is /sbin/drbdadm */
 100 char drbd_usermode_helper[80] = "/sbin/drbdadm";
 101 module_param_named(minor_count, drbd_minor_count, uint, 0444);
 102 module_param_string(usermode_helper, drbd_usermode_helper, sizeof(drbd_usermode_helper), 0644);
 103 
 104 /* in 2.6.x, our device mapping and config info contains our virtual gendisks
 105  * as member "struct gendisk *vdisk;"
 106  */
 107 struct idr drbd_devices;
 108 struct list_head drbd_resources;
 109 struct mutex resources_mutex;
 110 
 111 struct kmem_cache *drbd_request_cache;
 112 struct kmem_cache *drbd_ee_cache;       /* peer requests */
 113 struct kmem_cache *drbd_bm_ext_cache;   /* bitmap extents */
 114 struct kmem_cache *drbd_al_ext_cache;   /* activity log extents */
 115 mempool_t drbd_request_mempool;
 116 mempool_t drbd_ee_mempool;
 117 mempool_t drbd_md_io_page_pool;
 118 struct bio_set drbd_md_io_bio_set;
 119 struct bio_set drbd_io_bio_set;
 120 
 121 /* I do not use a standard mempool, because:
 122    1) I want to hand out the pre-allocated objects first.
 123    2) I want to be able to interrupt sleeping allocation with a signal.
 124    Note: This is a single linked list, the next pointer is the private
 125          member of struct page.
 126  */
 127 struct page *drbd_pp_pool;
 128 spinlock_t   drbd_pp_lock;
 129 int          drbd_pp_vacant;
 130 wait_queue_head_t drbd_pp_wait;
 131 
 132 DEFINE_RATELIMIT_STATE(drbd_ratelimit_state, 5 * HZ, 5);
 133 
 134 static const struct block_device_operations drbd_ops = {
 135         .owner =   THIS_MODULE,
 136         .open =    drbd_open,
 137         .release = drbd_release,
 138 };
 139 
 140 struct bio *bio_alloc_drbd(gfp_t gfp_mask)
 141 {
 142         struct bio *bio;
 143 
 144         if (!bioset_initialized(&drbd_md_io_bio_set))
 145                 return bio_alloc(gfp_mask, 1);
 146 
 147         bio = bio_alloc_bioset(gfp_mask, 1, &drbd_md_io_bio_set);
 148         if (!bio)
 149                 return NULL;
 150         return bio;
 151 }
 152 
 153 #ifdef __CHECKER__
 154 /* When checking with sparse, and this is an inline function, sparse will
 155    give tons of false positives. When this is a real functions sparse works.
 156  */
 157 int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins)
 158 {
 159         int io_allowed;
 160 
 161         atomic_inc(&device->local_cnt);
 162         io_allowed = (device->state.disk >= mins);
 163         if (!io_allowed) {
 164                 if (atomic_dec_and_test(&device->local_cnt))
 165                         wake_up(&device->misc_wait);
 166         }
 167         return io_allowed;
 168 }
 169 
 170 #endif
 171 
 172 /**
 173  * tl_release() - mark as BARRIER_ACKED all requests in the corresponding transfer log epoch
 174  * @connection: DRBD connection.
 175  * @barrier_nr: Expected identifier of the DRBD write barrier packet.
 176  * @set_size:   Expected number of requests before that barrier.
 177  *
 178  * In case the passed barrier_nr or set_size does not match the oldest
 179  * epoch of not yet barrier-acked requests, this function will cause a
 180  * termination of the connection.
 181  */
 182 void tl_release(struct drbd_connection *connection, unsigned int barrier_nr,
 183                 unsigned int set_size)
 184 {
 185         struct drbd_request *r;
 186         struct drbd_request *req = NULL;
 187         int expect_epoch = 0;
 188         int expect_size = 0;
 189 
 190         spin_lock_irq(&connection->resource->req_lock);
 191 
 192         /* find oldest not yet barrier-acked write request,
 193          * count writes in its epoch. */
 194         list_for_each_entry(r, &connection->transfer_log, tl_requests) {
 195                 const unsigned s = r->rq_state;
 196                 if (!req) {
 197                         if (!(s & RQ_WRITE))
 198                                 continue;
 199                         if (!(s & RQ_NET_MASK))
 200                                 continue;
 201                         if (s & RQ_NET_DONE)
 202                                 continue;
 203                         req = r;
 204                         expect_epoch = req->epoch;
 205                         expect_size ++;
 206                 } else {
 207                         if (r->epoch != expect_epoch)
 208                                 break;
 209                         if (!(s & RQ_WRITE))
 210                                 continue;
 211                         /* if (s & RQ_DONE): not expected */
 212                         /* if (!(s & RQ_NET_MASK)): not expected */
 213                         expect_size++;
 214                 }
 215         }
 216 
 217         /* first some paranoia code */
 218         if (req == NULL) {
 219                 drbd_err(connection, "BAD! BarrierAck #%u received, but no epoch in tl!?\n",
 220                          barrier_nr);
 221                 goto bail;
 222         }
 223         if (expect_epoch != barrier_nr) {
 224                 drbd_err(connection, "BAD! BarrierAck #%u received, expected #%u!\n",
 225                          barrier_nr, expect_epoch);
 226                 goto bail;
 227         }
 228 
 229         if (expect_size != set_size) {
 230                 drbd_err(connection, "BAD! BarrierAck #%u received with n_writes=%u, expected n_writes=%u!\n",
 231                          barrier_nr, set_size, expect_size);
 232                 goto bail;
 233         }
 234 
 235         /* Clean up list of requests processed during current epoch. */
 236         /* this extra list walk restart is paranoia,
 237          * to catch requests being barrier-acked "unexpectedly".
 238          * It usually should find the same req again, or some READ preceding it. */
 239         list_for_each_entry(req, &connection->transfer_log, tl_requests)
 240                 if (req->epoch == expect_epoch)
 241                         break;
 242         list_for_each_entry_safe_from(req, r, &connection->transfer_log, tl_requests) {
 243                 if (req->epoch != expect_epoch)
 244                         break;
 245                 _req_mod(req, BARRIER_ACKED);
 246         }
 247         spin_unlock_irq(&connection->resource->req_lock);
 248 
 249         return;
 250 
 251 bail:
 252         spin_unlock_irq(&connection->resource->req_lock);
 253         conn_request_state(connection, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
 254 }
 255 
 256 
 257 /**
 258  * _tl_restart() - Walks the transfer log, and applies an action to all requests
 259  * @connection: DRBD connection to operate on.
 260  * @what:       The action/event to perform with all request objects
 261  *
 262  * @what might be one of CONNECTION_LOST_WHILE_PENDING, RESEND, FAIL_FROZEN_DISK_IO,
 263  * RESTART_FROZEN_DISK_IO.
 264  */
 265 /* must hold resource->req_lock */
 266 void _tl_restart(struct drbd_connection *connection, enum drbd_req_event what)
 267 {
 268         struct drbd_request *req, *r;
 269 
 270         list_for_each_entry_safe(req, r, &connection->transfer_log, tl_requests)
 271                 _req_mod(req, what);
 272 }
 273 
 274 void tl_restart(struct drbd_connection *connection, enum drbd_req_event what)
 275 {
 276         spin_lock_irq(&connection->resource->req_lock);
 277         _tl_restart(connection, what);
 278         spin_unlock_irq(&connection->resource->req_lock);
 279 }
 280 
 281 /**
 282  * tl_clear() - Clears all requests and &struct drbd_tl_epoch objects out of the TL
 283  * @device:     DRBD device.
 284  *
 285  * This is called after the connection to the peer was lost. The storage covered
 286  * by the requests on the transfer gets marked as our of sync. Called from the
 287  * receiver thread and the worker thread.
 288  */
 289 void tl_clear(struct drbd_connection *connection)
 290 {
 291         tl_restart(connection, CONNECTION_LOST_WHILE_PENDING);
 292 }
 293 
 294 /**
 295  * tl_abort_disk_io() - Abort disk I/O for all requests for a certain device in the TL
 296  * @device:     DRBD device.
 297  */
 298 void tl_abort_disk_io(struct drbd_device *device)
 299 {
 300         struct drbd_connection *connection = first_peer_device(device)->connection;
 301         struct drbd_request *req, *r;
 302 
 303         spin_lock_irq(&connection->resource->req_lock);
 304         list_for_each_entry_safe(req, r, &connection->transfer_log, tl_requests) {
 305                 if (!(req->rq_state & RQ_LOCAL_PENDING))
 306                         continue;
 307                 if (req->device != device)
 308                         continue;
 309                 _req_mod(req, ABORT_DISK_IO);
 310         }
 311         spin_unlock_irq(&connection->resource->req_lock);
 312 }
 313 
 314 static int drbd_thread_setup(void *arg)
 315 {
 316         struct drbd_thread *thi = (struct drbd_thread *) arg;
 317         struct drbd_resource *resource = thi->resource;
 318         unsigned long flags;
 319         int retval;
 320 
 321         snprintf(current->comm, sizeof(current->comm), "drbd_%c_%s",
 322                  thi->name[0],
 323                  resource->name);
 324 
 325         allow_kernel_signal(DRBD_SIGKILL);
 326         allow_kernel_signal(SIGXCPU);
 327 restart:
 328         retval = thi->function(thi);
 329 
 330         spin_lock_irqsave(&thi->t_lock, flags);
 331 
 332         /* if the receiver has been "EXITING", the last thing it did
 333          * was set the conn state to "StandAlone",
 334          * if now a re-connect request comes in, conn state goes C_UNCONNECTED,
 335          * and receiver thread will be "started".
 336          * drbd_thread_start needs to set "RESTARTING" in that case.
 337          * t_state check and assignment needs to be within the same spinlock,
 338          * so either thread_start sees EXITING, and can remap to RESTARTING,
 339          * or thread_start see NONE, and can proceed as normal.
 340          */
 341 
 342         if (thi->t_state == RESTARTING) {
 343                 drbd_info(resource, "Restarting %s thread\n", thi->name);
 344                 thi->t_state = RUNNING;
 345                 spin_unlock_irqrestore(&thi->t_lock, flags);
 346                 goto restart;
 347         }
 348 
 349         thi->task = NULL;
 350         thi->t_state = NONE;
 351         smp_mb();
 352         complete_all(&thi->stop);
 353         spin_unlock_irqrestore(&thi->t_lock, flags);
 354 
 355         drbd_info(resource, "Terminating %s\n", current->comm);
 356 
 357         /* Release mod reference taken when thread was started */
 358 
 359         if (thi->connection)
 360                 kref_put(&thi->connection->kref, drbd_destroy_connection);
 361         kref_put(&resource->kref, drbd_destroy_resource);
 362         module_put(THIS_MODULE);
 363         return retval;
 364 }
 365 
 366 static void drbd_thread_init(struct drbd_resource *resource, struct drbd_thread *thi,
 367                              int (*func) (struct drbd_thread *), const char *name)
 368 {
 369         spin_lock_init(&thi->t_lock);
 370         thi->task    = NULL;
 371         thi->t_state = NONE;
 372         thi->function = func;
 373         thi->resource = resource;
 374         thi->connection = NULL;
 375         thi->name = name;
 376 }
 377 
 378 int drbd_thread_start(struct drbd_thread *thi)
 379 {
 380         struct drbd_resource *resource = thi->resource;
 381         struct task_struct *nt;
 382         unsigned long flags;
 383 
 384         /* is used from state engine doing drbd_thread_stop_nowait,
 385          * while holding the req lock irqsave */
 386         spin_lock_irqsave(&thi->t_lock, flags);
 387 
 388         switch (thi->t_state) {
 389         case NONE:
 390                 drbd_info(resource, "Starting %s thread (from %s [%d])\n",
 391                          thi->name, current->comm, current->pid);
 392 
 393                 /* Get ref on module for thread - this is released when thread exits */
 394                 if (!try_module_get(THIS_MODULE)) {
 395                         drbd_err(resource, "Failed to get module reference in drbd_thread_start\n");
 396                         spin_unlock_irqrestore(&thi->t_lock, flags);
 397                         return false;
 398                 }
 399 
 400                 kref_get(&resource->kref);
 401                 if (thi->connection)
 402                         kref_get(&thi->connection->kref);
 403 
 404                 init_completion(&thi->stop);
 405                 thi->reset_cpu_mask = 1;
 406                 thi->t_state = RUNNING;
 407                 spin_unlock_irqrestore(&thi->t_lock, flags);
 408                 flush_signals(current); /* otherw. may get -ERESTARTNOINTR */
 409 
 410                 nt = kthread_create(drbd_thread_setup, (void *) thi,
 411                                     "drbd_%c_%s", thi->name[0], thi->resource->name);
 412 
 413                 if (IS_ERR(nt)) {
 414                         drbd_err(resource, "Couldn't start thread\n");
 415 
 416                         if (thi->connection)
 417                                 kref_put(&thi->connection->kref, drbd_destroy_connection);
 418                         kref_put(&resource->kref, drbd_destroy_resource);
 419                         module_put(THIS_MODULE);
 420                         return false;
 421                 }
 422                 spin_lock_irqsave(&thi->t_lock, flags);
 423                 thi->task = nt;
 424                 thi->t_state = RUNNING;
 425                 spin_unlock_irqrestore(&thi->t_lock, flags);
 426                 wake_up_process(nt);
 427                 break;
 428         case EXITING:
 429                 thi->t_state = RESTARTING;
 430                 drbd_info(resource, "Restarting %s thread (from %s [%d])\n",
 431                                 thi->name, current->comm, current->pid);
 432                 /* fall through */
 433         case RUNNING:
 434         case RESTARTING:
 435         default:
 436                 spin_unlock_irqrestore(&thi->t_lock, flags);
 437                 break;
 438         }
 439 
 440         return true;
 441 }
 442 
 443 
 444 void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait)
 445 {
 446         unsigned long flags;
 447 
 448         enum drbd_thread_state ns = restart ? RESTARTING : EXITING;
 449 
 450         /* may be called from state engine, holding the req lock irqsave */
 451         spin_lock_irqsave(&thi->t_lock, flags);
 452 
 453         if (thi->t_state == NONE) {
 454                 spin_unlock_irqrestore(&thi->t_lock, flags);
 455                 if (restart)
 456                         drbd_thread_start(thi);
 457                 return;
 458         }
 459 
 460         if (thi->t_state != ns) {
 461                 if (thi->task == NULL) {
 462                         spin_unlock_irqrestore(&thi->t_lock, flags);
 463                         return;
 464                 }
 465 
 466                 thi->t_state = ns;
 467                 smp_mb();
 468                 init_completion(&thi->stop);
 469                 if (thi->task != current)
 470                         send_sig(DRBD_SIGKILL, thi->task, 1);
 471         }
 472 
 473         spin_unlock_irqrestore(&thi->t_lock, flags);
 474 
 475         if (wait)
 476                 wait_for_completion(&thi->stop);
 477 }
 478 
 479 int conn_lowest_minor(struct drbd_connection *connection)
 480 {
 481         struct drbd_peer_device *peer_device;
 482         int vnr = 0, minor = -1;
 483 
 484         rcu_read_lock();
 485         peer_device = idr_get_next(&connection->peer_devices, &vnr);
 486         if (peer_device)
 487                 minor = device_to_minor(peer_device->device);
 488         rcu_read_unlock();
 489 
 490         return minor;
 491 }
 492 
 493 #ifdef CONFIG_SMP
 494 /**
 495  * drbd_calc_cpu_mask() - Generate CPU masks, spread over all CPUs
 496  *
 497  * Forces all threads of a resource onto the same CPU. This is beneficial for
 498  * DRBD's performance. May be overwritten by user's configuration.
 499  */
 500 static void drbd_calc_cpu_mask(cpumask_var_t *cpu_mask)
 501 {
 502         unsigned int *resources_per_cpu, min_index = ~0;
 503 
 504         resources_per_cpu = kcalloc(nr_cpu_ids, sizeof(*resources_per_cpu),
 505                                     GFP_KERNEL);
 506         if (resources_per_cpu) {
 507                 struct drbd_resource *resource;
 508                 unsigned int cpu, min = ~0;
 509 
 510                 rcu_read_lock();
 511                 for_each_resource_rcu(resource, &drbd_resources) {
 512                         for_each_cpu(cpu, resource->cpu_mask)
 513                                 resources_per_cpu[cpu]++;
 514                 }
 515                 rcu_read_unlock();
 516                 for_each_online_cpu(cpu) {
 517                         if (resources_per_cpu[cpu] < min) {
 518                                 min = resources_per_cpu[cpu];
 519                                 min_index = cpu;
 520                         }
 521                 }
 522                 kfree(resources_per_cpu);
 523         }
 524         if (min_index == ~0) {
 525                 cpumask_setall(*cpu_mask);
 526                 return;
 527         }
 528         cpumask_set_cpu(min_index, *cpu_mask);
 529 }
 530 
 531 /**
 532  * drbd_thread_current_set_cpu() - modifies the cpu mask of the _current_ thread
 533  * @device:     DRBD device.
 534  * @thi:        drbd_thread object
 535  *
 536  * call in the "main loop" of _all_ threads, no need for any mutex, current won't die
 537  * prematurely.
 538  */
 539 void drbd_thread_current_set_cpu(struct drbd_thread *thi)
 540 {
 541         struct drbd_resource *resource = thi->resource;
 542         struct task_struct *p = current;
 543 
 544         if (!thi->reset_cpu_mask)
 545                 return;
 546         thi->reset_cpu_mask = 0;
 547         set_cpus_allowed_ptr(p, resource->cpu_mask);
 548 }
 549 #else
 550 #define drbd_calc_cpu_mask(A) ({})
 551 #endif
 552 
 553 /**
 554  * drbd_header_size  -  size of a packet header
 555  *
 556  * The header size is a multiple of 8, so any payload following the header is
 557  * word aligned on 64-bit architectures.  (The bitmap send and receive code
 558  * relies on this.)
 559  */
 560 unsigned int drbd_header_size(struct drbd_connection *connection)
 561 {
 562         if (connection->agreed_pro_version >= 100) {
 563                 BUILD_BUG_ON(!IS_ALIGNED(sizeof(struct p_header100), 8));
 564                 return sizeof(struct p_header100);
 565         } else {
 566                 BUILD_BUG_ON(sizeof(struct p_header80) !=
 567                              sizeof(struct p_header95));
 568                 BUILD_BUG_ON(!IS_ALIGNED(sizeof(struct p_header80), 8));
 569                 return sizeof(struct p_header80);
 570         }
 571 }
 572 
 573 static unsigned int prepare_header80(struct p_header80 *h, enum drbd_packet cmd, int size)
 574 {
 575         h->magic   = cpu_to_be32(DRBD_MAGIC);
 576         h->command = cpu_to_be16(cmd);
 577         h->length  = cpu_to_be16(size);
 578         return sizeof(struct p_header80);
 579 }
 580 
 581 static unsigned int prepare_header95(struct p_header95 *h, enum drbd_packet cmd, int size)
 582 {
 583         h->magic   = cpu_to_be16(DRBD_MAGIC_BIG);
 584         h->command = cpu_to_be16(cmd);
 585         h->length = cpu_to_be32(size);
 586         return sizeof(struct p_header95);
 587 }
 588 
 589 static unsigned int prepare_header100(struct p_header100 *h, enum drbd_packet cmd,
 590                                       int size, int vnr)
 591 {
 592         h->magic = cpu_to_be32(DRBD_MAGIC_100);
 593         h->volume = cpu_to_be16(vnr);
 594         h->command = cpu_to_be16(cmd);
 595         h->length = cpu_to_be32(size);
 596         h->pad = 0;
 597         return sizeof(struct p_header100);
 598 }
 599 
 600 static unsigned int prepare_header(struct drbd_connection *connection, int vnr,
 601                                    void *buffer, enum drbd_packet cmd, int size)
 602 {
 603         if (connection->agreed_pro_version >= 100)
 604                 return prepare_header100(buffer, cmd, size, vnr);
 605         else if (connection->agreed_pro_version >= 95 &&
 606                  size > DRBD_MAX_SIZE_H80_PACKET)
 607                 return prepare_header95(buffer, cmd, size);
 608         else
 609                 return prepare_header80(buffer, cmd, size);
 610 }
 611 
 612 static void *__conn_prepare_command(struct drbd_connection *connection,
 613                                     struct drbd_socket *sock)
 614 {
 615         if (!sock->socket)
 616                 return NULL;
 617         return sock->sbuf + drbd_header_size(connection);
 618 }
 619 
 620 void *conn_prepare_command(struct drbd_connection *connection, struct drbd_socket *sock)
 621 {
 622         void *p;
 623 
 624         mutex_lock(&sock->mutex);
 625         p = __conn_prepare_command(connection, sock);
 626         if (!p)
 627                 mutex_unlock(&sock->mutex);
 628 
 629         return p;
 630 }
 631 
 632 void *drbd_prepare_command(struct drbd_peer_device *peer_device, struct drbd_socket *sock)
 633 {
 634         return conn_prepare_command(peer_device->connection, sock);
 635 }
 636 
 637 static int __send_command(struct drbd_connection *connection, int vnr,
 638                           struct drbd_socket *sock, enum drbd_packet cmd,
 639                           unsigned int header_size, void *data,
 640                           unsigned int size)
 641 {
 642         int msg_flags;
 643         int err;
 644 
 645         /*
 646          * Called with @data == NULL and the size of the data blocks in @size
 647          * for commands that send data blocks.  For those commands, omit the
 648          * MSG_MORE flag: this will increase the likelihood that data blocks
 649          * which are page aligned on the sender will end up page aligned on the
 650          * receiver.
 651          */
 652         msg_flags = data ? MSG_MORE : 0;
 653 
 654         header_size += prepare_header(connection, vnr, sock->sbuf, cmd,
 655                                       header_size + size);
 656         err = drbd_send_all(connection, sock->socket, sock->sbuf, header_size,
 657                             msg_flags);
 658         if (data && !err)
 659                 err = drbd_send_all(connection, sock->socket, data, size, 0);
 660         /* DRBD protocol "pings" are latency critical.
 661          * This is supposed to trigger tcp_push_pending_frames() */
 662         if (!err && (cmd == P_PING || cmd == P_PING_ACK))
 663                 drbd_tcp_nodelay(sock->socket);
 664 
 665         return err;
 666 }
 667 
 668 static int __conn_send_command(struct drbd_connection *connection, struct drbd_socket *sock,
 669                                enum drbd_packet cmd, unsigned int header_size,
 670                                void *data, unsigned int size)
 671 {
 672         return __send_command(connection, 0, sock, cmd, header_size, data, size);
 673 }
 674 
 675 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         int err;
 680 
 681         err = __conn_send_command(connection, sock, cmd, header_size, data, size);
 682         mutex_unlock(&sock->mutex);
 683         return err;
 684 }
 685 
 686 int drbd_send_command(struct drbd_peer_device *peer_device, struct drbd_socket *sock,
 687                       enum drbd_packet cmd, unsigned int header_size,
 688                       void *data, unsigned int size)
 689 {
 690         int err;
 691 
 692         err = __send_command(peer_device->connection, peer_device->device->vnr,
 693                              sock, cmd, header_size, data, size);
 694         mutex_unlock(&sock->mutex);
 695         return err;
 696 }
 697 
 698 int drbd_send_ping(struct drbd_connection *connection)
 699 {
 700         struct drbd_socket *sock;
 701 
 702         sock = &connection->meta;
 703         if (!conn_prepare_command(connection, sock))
 704                 return -EIO;
 705         return conn_send_command(connection, sock, P_PING, 0, NULL, 0);
 706 }
 707 
 708 int drbd_send_ping_ack(struct drbd_connection *connection)
 709 {
 710         struct drbd_socket *sock;
 711 
 712         sock = &connection->meta;
 713         if (!conn_prepare_command(connection, sock))
 714                 return -EIO;
 715         return conn_send_command(connection, sock, P_PING_ACK, 0, NULL, 0);
 716 }
 717 
 718 int drbd_send_sync_param(struct drbd_peer_device *peer_device)
 719 {
 720         struct drbd_socket *sock;
 721         struct p_rs_param_95 *p;
 722         int size;
 723         const int apv = peer_device->connection->agreed_pro_version;
 724         enum drbd_packet cmd;
 725         struct net_conf *nc;
 726         struct disk_conf *dc;
 727 
 728         sock = &peer_device->connection->data;
 729         p = drbd_prepare_command(peer_device, sock);
 730         if (!p)
 731                 return -EIO;
 732 
 733         rcu_read_lock();
 734         nc = rcu_dereference(peer_device->connection->net_conf);
 735 
 736         size = apv <= 87 ? sizeof(struct p_rs_param)
 737                 : apv == 88 ? sizeof(struct p_rs_param)
 738                         + strlen(nc->verify_alg) + 1
 739                 : apv <= 94 ? sizeof(struct p_rs_param_89)
 740                 : /* apv >= 95 */ sizeof(struct p_rs_param_95);
 741 
 742         cmd = apv >= 89 ? P_SYNC_PARAM89 : P_SYNC_PARAM;
 743 
 744         /* initialize verify_alg and csums_alg */
 745         memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);
 746 
 747         if (get_ldev(peer_device->device)) {
 748                 dc = rcu_dereference(peer_device->device->ldev->disk_conf);
 749                 p->resync_rate = cpu_to_be32(dc->resync_rate);
 750                 p->c_plan_ahead = cpu_to_be32(dc->c_plan_ahead);
 751                 p->c_delay_target = cpu_to_be32(dc->c_delay_target);
 752                 p->c_fill_target = cpu_to_be32(dc->c_fill_target);
 753                 p->c_max_rate = cpu_to_be32(dc->c_max_rate);
 754                 put_ldev(peer_device->device);
 755         } else {
 756                 p->resync_rate = cpu_to_be32(DRBD_RESYNC_RATE_DEF);
 757                 p->c_plan_ahead = cpu_to_be32(DRBD_C_PLAN_AHEAD_DEF);
 758                 p->c_delay_target = cpu_to_be32(DRBD_C_DELAY_TARGET_DEF);
 759                 p->c_fill_target = cpu_to_be32(DRBD_C_FILL_TARGET_DEF);
 760                 p->c_max_rate = cpu_to_be32(DRBD_C_MAX_RATE_DEF);
 761         }
 762 
 763         if (apv >= 88)
 764                 strcpy(p->verify_alg, nc->verify_alg);
 765         if (apv >= 89)
 766                 strcpy(p->csums_alg, nc->csums_alg);
 767         rcu_read_unlock();
 768 
 769         return drbd_send_command(peer_device, sock, cmd, size, NULL, 0);
 770 }
 771 
 772 int __drbd_send_protocol(struct drbd_connection *connection, enum drbd_packet cmd)
 773 {
 774         struct drbd_socket *sock;
 775         struct p_protocol *p;
 776         struct net_conf *nc;
 777         int size, cf;
 778 
 779         sock = &connection->data;
 780         p = __conn_prepare_command(connection, sock);
 781         if (!p)
 782                 return -EIO;
 783 
 784         rcu_read_lock();
 785         nc = rcu_dereference(connection->net_conf);
 786 
 787         if (nc->tentative && connection->agreed_pro_version < 92) {
 788                 rcu_read_unlock();
 789                 drbd_err(connection, "--dry-run is not supported by peer");
 790                 return -EOPNOTSUPP;
 791         }
 792 
 793         size = sizeof(*p);
 794         if (connection->agreed_pro_version >= 87)
 795                 size += strlen(nc->integrity_alg) + 1;
 796 
 797         p->protocol      = cpu_to_be32(nc->wire_protocol);
 798         p->after_sb_0p   = cpu_to_be32(nc->after_sb_0p);
 799         p->after_sb_1p   = cpu_to_be32(nc->after_sb_1p);
 800         p->after_sb_2p   = cpu_to_be32(nc->after_sb_2p);
 801         p->two_primaries = cpu_to_be32(nc->two_primaries);
 802         cf = 0;
 803         if (nc->discard_my_data)
 804                 cf |= CF_DISCARD_MY_DATA;
 805         if (nc->tentative)
 806                 cf |= CF_DRY_RUN;
 807         p->conn_flags    = cpu_to_be32(cf);
 808 
 809         if (connection->agreed_pro_version >= 87)
 810                 strcpy(p->integrity_alg, nc->integrity_alg);
 811         rcu_read_unlock();
 812 
 813         return __conn_send_command(connection, sock, cmd, size, NULL, 0);
 814 }
 815 
 816 int drbd_send_protocol(struct drbd_connection *connection)
 817 {
 818         int err;
 819 
 820         mutex_lock(&connection->data.mutex);
 821         err = __drbd_send_protocol(connection, P_PROTOCOL);
 822         mutex_unlock(&connection->data.mutex);
 823 
 824         return err;
 825 }
 826 
 827 static int _drbd_send_uuids(struct drbd_peer_device *peer_device, u64 uuid_flags)
 828 {
 829         struct drbd_device *device = peer_device->device;
 830         struct drbd_socket *sock;
 831         struct p_uuids *p;
 832         int i;
 833 
 834         if (!get_ldev_if_state(device, D_NEGOTIATING))
 835                 return 0;
 836 
 837         sock = &peer_device->connection->data;
 838         p = drbd_prepare_command(peer_device, sock);
 839         if (!p) {
 840                 put_ldev(device);
 841                 return -EIO;
 842         }
 843         spin_lock_irq(&device->ldev->md.uuid_lock);
 844         for (i = UI_CURRENT; i < UI_SIZE; i++)
 845                 p->uuid[i] = cpu_to_be64(device->ldev->md.uuid[i]);
 846         spin_unlock_irq(&device->ldev->md.uuid_lock);
 847 
 848         device->comm_bm_set = drbd_bm_total_weight(device);
 849         p->uuid[UI_SIZE] = cpu_to_be64(device->comm_bm_set);
 850         rcu_read_lock();
 851         uuid_flags |= rcu_dereference(peer_device->connection->net_conf)->discard_my_data ? 1 : 0;
 852         rcu_read_unlock();
 853         uuid_flags |= test_bit(CRASHED_PRIMARY, &device->flags) ? 2 : 0;
 854         uuid_flags |= device->new_state_tmp.disk == D_INCONSISTENT ? 4 : 0;
 855         p->uuid[UI_FLAGS] = cpu_to_be64(uuid_flags);
 856 
 857         put_ldev(device);
 858         return drbd_send_command(peer_device, sock, P_UUIDS, sizeof(*p), NULL, 0);
 859 }
 860 
 861 int drbd_send_uuids(struct drbd_peer_device *peer_device)
 862 {
 863         return _drbd_send_uuids(peer_device, 0);
 864 }
 865 
 866 int drbd_send_uuids_skip_initial_sync(struct drbd_peer_device *peer_device)
 867 {
 868         return _drbd_send_uuids(peer_device, 8);
 869 }
 870 
 871 void drbd_print_uuids(struct drbd_device *device, const char *text)
 872 {
 873         if (get_ldev_if_state(device, D_NEGOTIATING)) {
 874                 u64 *uuid = device->ldev->md.uuid;
 875                 drbd_info(device, "%s %016llX:%016llX:%016llX:%016llX\n",
 876                      text,
 877                      (unsigned long long)uuid[UI_CURRENT],
 878                      (unsigned long long)uuid[UI_BITMAP],
 879                      (unsigned long long)uuid[UI_HISTORY_START],
 880                      (unsigned long long)uuid[UI_HISTORY_END]);
 881                 put_ldev(device);
 882         } else {
 883                 drbd_info(device, "%s effective data uuid: %016llX\n",
 884                                 text,
 885                                 (unsigned long long)device->ed_uuid);
 886         }
 887 }
 888 
 889 void drbd_gen_and_send_sync_uuid(struct drbd_peer_device *peer_device)
 890 {
 891         struct drbd_device *device = peer_device->device;
 892         struct drbd_socket *sock;
 893         struct p_rs_uuid *p;
 894         u64 uuid;
 895 
 896         D_ASSERT(device, device->state.disk == D_UP_TO_DATE);
 897 
 898         uuid = device->ldev->md.uuid[UI_BITMAP];
 899         if (uuid && uuid != UUID_JUST_CREATED)
 900                 uuid = uuid + UUID_NEW_BM_OFFSET;
 901         else
 902                 get_random_bytes(&uuid, sizeof(u64));
 903         drbd_uuid_set(device, UI_BITMAP, uuid);
 904         drbd_print_uuids(device, "updated sync UUID");
 905         drbd_md_sync(device);
 906 
 907         sock = &peer_device->connection->data;
 908         p = drbd_prepare_command(peer_device, sock);
 909         if (p) {
 910                 p->uuid = cpu_to_be64(uuid);
 911                 drbd_send_command(peer_device, sock, P_SYNC_UUID, sizeof(*p), NULL, 0);
 912         }
 913 }
 914 
 915 /* communicated if (agreed_features & DRBD_FF_WSAME) */
 916 static void
 917 assign_p_sizes_qlim(struct drbd_device *device, struct p_sizes *p,
 918                                         struct request_queue *q)
 919 {
 920         if (q) {
 921                 p->qlim->physical_block_size = cpu_to_be32(queue_physical_block_size(q));
 922                 p->qlim->logical_block_size = cpu_to_be32(queue_logical_block_size(q));
 923                 p->qlim->alignment_offset = cpu_to_be32(queue_alignment_offset(q));
 924                 p->qlim->io_min = cpu_to_be32(queue_io_min(q));
 925                 p->qlim->io_opt = cpu_to_be32(queue_io_opt(q));
 926                 p->qlim->discard_enabled = blk_queue_discard(q);
 927                 p->qlim->write_same_capable = !!q->limits.max_write_same_sectors;
 928         } else {
 929                 q = device->rq_queue;
 930                 p->qlim->physical_block_size = cpu_to_be32(queue_physical_block_size(q));
 931                 p->qlim->logical_block_size = cpu_to_be32(queue_logical_block_size(q));
 932                 p->qlim->alignment_offset = 0;
 933                 p->qlim->io_min = cpu_to_be32(queue_io_min(q));
 934                 p->qlim->io_opt = cpu_to_be32(queue_io_opt(q));
 935                 p->qlim->discard_enabled = 0;
 936                 p->qlim->write_same_capable = 0;
 937         }
 938 }
 939 
 940 int drbd_send_sizes(struct drbd_peer_device *peer_device, int trigger_reply, enum dds_flags flags)
 941 {
 942         struct drbd_device *device = peer_device->device;
 943         struct drbd_socket *sock;
 944         struct p_sizes *p;
 945         sector_t d_size, u_size;
 946         int q_order_type;
 947         unsigned int max_bio_size;
 948         unsigned int packet_size;
 949 
 950         sock = &peer_device->connection->data;
 951         p = drbd_prepare_command(peer_device, sock);
 952         if (!p)
 953                 return -EIO;
 954 
 955         packet_size = sizeof(*p);
 956         if (peer_device->connection->agreed_features & DRBD_FF_WSAME)
 957                 packet_size += sizeof(p->qlim[0]);
 958 
 959         memset(p, 0, packet_size);
 960         if (get_ldev_if_state(device, D_NEGOTIATING)) {
 961                 struct request_queue *q = bdev_get_queue(device->ldev->backing_bdev);
 962                 d_size = drbd_get_max_capacity(device->ldev);
 963                 rcu_read_lock();
 964                 u_size = rcu_dereference(device->ldev->disk_conf)->disk_size;
 965                 rcu_read_unlock();
 966                 q_order_type = drbd_queue_order_type(device);
 967                 max_bio_size = queue_max_hw_sectors(q) << 9;
 968                 max_bio_size = min(max_bio_size, DRBD_MAX_BIO_SIZE);
 969                 assign_p_sizes_qlim(device, p, q);
 970                 put_ldev(device);
 971         } else {
 972                 d_size = 0;
 973                 u_size = 0;
 974                 q_order_type = QUEUE_ORDERED_NONE;
 975                 max_bio_size = DRBD_MAX_BIO_SIZE; /* ... multiple BIOs per peer_request */
 976                 assign_p_sizes_qlim(device, p, NULL);
 977         }
 978 
 979         if (peer_device->connection->agreed_pro_version <= 94)
 980                 max_bio_size = min(max_bio_size, DRBD_MAX_SIZE_H80_PACKET);
 981         else if (peer_device->connection->agreed_pro_version < 100)
 982                 max_bio_size = min(max_bio_size, DRBD_MAX_BIO_SIZE_P95);
 983 
 984         p->d_size = cpu_to_be64(d_size);
 985         p->u_size = cpu_to_be64(u_size);
 986         p->c_size = cpu_to_be64(trigger_reply ? 0 : drbd_get_capacity(device->this_bdev));
 987         p->max_bio_size = cpu_to_be32(max_bio_size);
 988         p->queue_order_type = cpu_to_be16(q_order_type);
 989         p->dds_flags = cpu_to_be16(flags);
 990 
 991         return drbd_send_command(peer_device, sock, P_SIZES, packet_size, NULL, 0);
 992 }
 993 
 994 /**
 995  * drbd_send_current_state() - Sends the drbd state to the peer
 996  * @peer_device:        DRBD peer device.
 997  */
 998 int drbd_send_current_state(struct drbd_peer_device *peer_device)
 999 {
1000         struct drbd_socket *sock;
1001         struct p_state *p;
1002 
1003         sock = &peer_device->connection->data;
1004         p = drbd_prepare_command(peer_device, sock);
1005         if (!p)
1006                 return -EIO;
1007         p->state = cpu_to_be32(peer_device->device->state.i); /* Within the send mutex */
1008         return drbd_send_command(peer_device, sock, P_STATE, sizeof(*p), NULL, 0);
1009 }
1010 
1011 /**
1012  * drbd_send_state() - After a state change, sends the new state to the peer
1013  * @peer_device:      DRBD peer device.
1014  * @state:     the state to send, not necessarily the current state.
1015  *
1016  * Each state change queues an "after_state_ch" work, which will eventually
1017  * send the resulting new state to the peer. If more state changes happen
1018  * between queuing and processing of the after_state_ch work, we still
1019  * want to send each intermediary state in the order it occurred.
1020  */
1021 int drbd_send_state(struct drbd_peer_device *peer_device, union drbd_state state)
1022 {
1023         struct drbd_socket *sock;
1024         struct p_state *p;
1025 
1026         sock = &peer_device->connection->data;
1027         p = drbd_prepare_command(peer_device, sock);
1028         if (!p)
1029                 return -EIO;
1030         p->state = cpu_to_be32(state.i); /* Within the send mutex */
1031         return drbd_send_command(peer_device, sock, P_STATE, sizeof(*p), NULL, 0);
1032 }
1033 
1034 int drbd_send_state_req(struct drbd_peer_device *peer_device, union drbd_state mask, union drbd_state val)
1035 {
1036         struct drbd_socket *sock;
1037         struct p_req_state *p;
1038 
1039         sock = &peer_device->connection->data;
1040         p = drbd_prepare_command(peer_device, sock);
1041         if (!p)
1042                 return -EIO;
1043         p->mask = cpu_to_be32(mask.i);
1044         p->val = cpu_to_be32(val.i);
1045         return drbd_send_command(peer_device, sock, P_STATE_CHG_REQ, sizeof(*p), NULL, 0);
1046 }
1047 
1048 int conn_send_state_req(struct drbd_connection *connection, union drbd_state mask, union drbd_state val)
1049 {
1050         enum drbd_packet cmd;
1051         struct drbd_socket *sock;
1052         struct p_req_state *p;
1053 
1054         cmd = connection->agreed_pro_version < 100 ? P_STATE_CHG_REQ : P_CONN_ST_CHG_REQ;
1055         sock = &connection->data;
1056         p = conn_prepare_command(connection, sock);
1057         if (!p)
1058                 return -EIO;
1059         p->mask = cpu_to_be32(mask.i);
1060         p->val = cpu_to_be32(val.i);
1061         return conn_send_command(connection, sock, cmd, sizeof(*p), NULL, 0);
1062 }
1063 
1064 void drbd_send_sr_reply(struct drbd_peer_device *peer_device, enum drbd_state_rv retcode)
1065 {
1066         struct drbd_socket *sock;
1067         struct p_req_state_reply *p;
1068 
1069         sock = &peer_device->connection->meta;
1070         p = drbd_prepare_command(peer_device, sock);
1071         if (p) {
1072                 p->retcode = cpu_to_be32(retcode);
1073                 drbd_send_command(peer_device, sock, P_STATE_CHG_REPLY, sizeof(*p), NULL, 0);
1074         }
1075 }
1076 
1077 void conn_send_sr_reply(struct drbd_connection *connection, enum drbd_state_rv retcode)
1078 {
1079         struct drbd_socket *sock;
1080         struct p_req_state_reply *p;
1081         enum drbd_packet cmd = connection->agreed_pro_version < 100 ? P_STATE_CHG_REPLY : P_CONN_ST_CHG_REPLY;
1082 
1083         sock = &connection->meta;
1084         p = conn_prepare_command(connection, sock);
1085         if (p) {
1086                 p->retcode = cpu_to_be32(retcode);
1087                 conn_send_command(connection, sock, cmd, sizeof(*p), NULL, 0);
1088         }
1089 }
1090 
1091 static void dcbp_set_code(struct p_compressed_bm *p, enum drbd_bitmap_code code)
1092 {
1093         BUG_ON(code & ~0xf);
1094         p->encoding = (p->encoding & ~0xf) | code;
1095 }
1096 
1097 static void dcbp_set_start(struct p_compressed_bm *p, int set)
1098 {
1099         p->encoding = (p->encoding & ~0x80) | (set ? 0x80 : 0);
1100 }
1101 
1102 static void dcbp_set_pad_bits(struct p_compressed_bm *p, int n)
1103 {
1104         BUG_ON(n & ~0x7);
1105         p->encoding = (p->encoding & (~0x7 << 4)) | (n << 4);
1106 }
1107 
1108 static int fill_bitmap_rle_bits(struct drbd_device *device,
1109                          struct p_compressed_bm *p,
1110                          unsigned int size,
1111                          struct bm_xfer_ctx *c)
1112 {
1113         struct bitstream bs;
1114         unsigned long plain_bits;
1115         unsigned long tmp;
1116         unsigned long rl;
1117         unsigned len;
1118         unsigned toggle;
1119         int bits, use_rle;
1120 
1121         /* may we use this feature? */
1122         rcu_read_lock();
1123         use_rle = rcu_dereference(first_peer_device(device)->connection->net_conf)->use_rle;
1124         rcu_read_unlock();
1125         if (!use_rle || first_peer_device(device)->connection->agreed_pro_version < 90)
1126                 return 0;
1127 
1128         if (c->bit_offset >= c->bm_bits)
1129                 return 0; /* nothing to do. */
1130 
1131         /* use at most thus many bytes */
1132         bitstream_init(&bs, p->code, size, 0);
1133         memset(p->code, 0, size);
1134         /* plain bits covered in this code string */
1135         plain_bits = 0;
1136 
1137         /* p->encoding & 0x80 stores whether the first run length is set.
1138          * bit offset is implicit.
1139          * start with toggle == 2 to be able to tell the first iteration */
1140         toggle = 2;
1141 
1142         /* see how much plain bits we can stuff into one packet
1143          * using RLE and VLI. */
1144         do {
1145                 tmp = (toggle == 0) ? _drbd_bm_find_next_zero(device, c->bit_offset)
1146                                     : _drbd_bm_find_next(device, c->bit_offset);
1147                 if (tmp == -1UL)
1148                         tmp = c->bm_bits;
1149                 rl = tmp - c->bit_offset;
1150 
1151                 if (toggle == 2) { /* first iteration */
1152                         if (rl == 0) {
1153                                 /* the first checked bit was set,
1154                                  * store start value, */
1155                                 dcbp_set_start(p, 1);
1156                                 /* but skip encoding of zero run length */
1157                                 toggle = !toggle;
1158                                 continue;
1159                         }
1160                         dcbp_set_start(p, 0);
1161                 }
1162 
1163                 /* paranoia: catch zero runlength.
1164                  * can only happen if bitmap is modified while we scan it. */
1165                 if (rl == 0) {
1166                         drbd_err(device, "unexpected zero runlength while encoding bitmap "
1167                             "t:%u bo:%lu\n", toggle, c->bit_offset);
1168                         return -1;
1169                 }
1170 
1171                 bits = vli_encode_bits(&bs, rl);
1172                 if (bits == -ENOBUFS) /* buffer full */
1173                         break;
1174                 if (bits <= 0) {
1175                         drbd_err(device, "error while encoding bitmap: %d\n", bits);
1176                         return 0;
1177                 }
1178 
1179                 toggle = !toggle;
1180                 plain_bits += rl;
1181                 c->bit_offset = tmp;
1182         } while (c->bit_offset < c->bm_bits);
1183 
1184         len = bs.cur.b - p->code + !!bs.cur.bit;
1185 
1186         if (plain_bits < (len << 3)) {
1187                 /* incompressible with this method.
1188                  * we need to rewind both word and bit position. */
1189                 c->bit_offset -= plain_bits;
1190                 bm_xfer_ctx_bit_to_word_offset(c);
1191                 c->bit_offset = c->word_offset * BITS_PER_LONG;
1192                 return 0;
1193         }
1194 
1195         /* RLE + VLI was able to compress it just fine.
1196          * update c->word_offset. */
1197         bm_xfer_ctx_bit_to_word_offset(c);
1198 
1199         /* store pad_bits */
1200         dcbp_set_pad_bits(p, (8 - bs.cur.bit) & 0x7);
1201 
1202         return len;
1203 }
1204 
1205 /**
1206  * send_bitmap_rle_or_plain
1207  *
1208  * Return 0 when done, 1 when another iteration is needed, and a negative error
1209  * code upon failure.
1210  */
1211 static int
1212 send_bitmap_rle_or_plain(struct drbd_device *device, struct bm_xfer_ctx *c)
1213 {
1214         struct drbd_socket *sock = &first_peer_device(device)->connection->data;
1215         unsigned int header_size = drbd_header_size(first_peer_device(device)->connection);
1216         struct p_compressed_bm *p = sock->sbuf + header_size;
1217         int len, err;
1218 
1219         len = fill_bitmap_rle_bits(device, p,
1220                         DRBD_SOCKET_BUFFER_SIZE - header_size - sizeof(*p), c);
1221         if (len < 0)
1222                 return -EIO;
1223 
1224         if (len) {
1225                 dcbp_set_code(p, RLE_VLI_Bits);
1226                 err = __send_command(first_peer_device(device)->connection, device->vnr, sock,
1227                                      P_COMPRESSED_BITMAP, sizeof(*p) + len,
1228                                      NULL, 0);
1229                 c->packets[0]++;
1230                 c->bytes[0] += header_size + sizeof(*p) + len;
1231 
1232                 if (c->bit_offset >= c->bm_bits)
1233                         len = 0; /* DONE */
1234         } else {
1235                 /* was not compressible.
1236                  * send a buffer full of plain text bits instead. */
1237                 unsigned int data_size;
1238                 unsigned long num_words;
1239                 unsigned long *p = sock->sbuf + header_size;
1240 
1241                 data_size = DRBD_SOCKET_BUFFER_SIZE - header_size;
1242                 num_words = min_t(size_t, data_size / sizeof(*p),
1243                                   c->bm_words - c->word_offset);
1244                 len = num_words * sizeof(*p);
1245                 if (len)
1246                         drbd_bm_get_lel(device, c->word_offset, num_words, p);
1247                 err = __send_command(first_peer_device(device)->connection, device->vnr, sock, P_BITMAP, len, NULL, 0);
1248                 c->word_offset += num_words;
1249                 c->bit_offset = c->word_offset * BITS_PER_LONG;
1250 
1251                 c->packets[1]++;
1252                 c->bytes[1] += header_size + len;
1253 
1254                 if (c->bit_offset > c->bm_bits)
1255                         c->bit_offset = c->bm_bits;
1256         }
1257         if (!err) {
1258                 if (len == 0) {
1259                         INFO_bm_xfer_stats(device, "send", c);
1260                         return 0;
1261                 } else
1262                         return 1;
1263         }
1264         return -EIO;
1265 }
1266 
1267 /* See the comment at receive_bitmap() */
1268 static int _drbd_send_bitmap(struct drbd_device *device)
1269 {
1270         struct bm_xfer_ctx c;
1271         int err;
1272 
1273         if (!expect(device->bitmap))
1274                 return false;
1275 
1276         if (get_ldev(device)) {
1277                 if (drbd_md_test_flag(device->ldev, MDF_FULL_SYNC)) {
1278                         drbd_info(device, "Writing the whole bitmap, MDF_FullSync was set.\n");
1279                         drbd_bm_set_all(device);
1280                         if (drbd_bm_write(device)) {
1281                                 /* write_bm did fail! Leave full sync flag set in Meta P_DATA
1282                                  * but otherwise process as per normal - need to tell other
1283                                  * side that a full resync is required! */
1284                                 drbd_err(device, "Failed to write bitmap to disk!\n");
1285                         } else {
1286                                 drbd_md_clear_flag(device, MDF_FULL_SYNC);
1287                                 drbd_md_sync(device);
1288                         }
1289                 }
1290                 put_ldev(device);
1291         }
1292 
1293         c = (struct bm_xfer_ctx) {
1294                 .bm_bits = drbd_bm_bits(device),
1295                 .bm_words = drbd_bm_words(device),
1296         };
1297 
1298         do {
1299                 err = send_bitmap_rle_or_plain(device, &c);
1300         } while (err > 0);
1301 
1302         return err == 0;
1303 }
1304 
1305 int drbd_send_bitmap(struct drbd_device *device)
1306 {
1307         struct drbd_socket *sock = &first_peer_device(device)->connection->data;
1308         int err = -1;
1309 
1310         mutex_lock(&sock->mutex);
1311         if (sock->socket)
1312                 err = !_drbd_send_bitmap(device);
1313         mutex_unlock(&sock->mutex);
1314         return err;
1315 }
1316 
1317 void drbd_send_b_ack(struct drbd_connection *connection, u32 barrier_nr, u32 set_size)
1318 {
1319         struct drbd_socket *sock;
1320         struct p_barrier_ack *p;
1321 
1322         if (connection->cstate < C_WF_REPORT_PARAMS)
1323                 return;
1324 
1325         sock = &connection->meta;
1326         p = conn_prepare_command(connection, sock);
1327         if (!p)
1328                 return;
1329         p->barrier = barrier_nr;
1330         p->set_size = cpu_to_be32(set_size);
1331         conn_send_command(connection, sock, P_BARRIER_ACK, sizeof(*p), NULL, 0);
1332 }
1333 
1334 /**
1335  * _drbd_send_ack() - Sends an ack packet
1336  * @device:     DRBD device.
1337  * @cmd:        Packet command code.
1338  * @sector:     sector, needs to be in big endian byte order
1339  * @blksize:    size in byte, needs to be in big endian byte order
1340  * @block_id:   Id, big endian byte order
1341  */
1342 static int _drbd_send_ack(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1343                           u64 sector, u32 blksize, u64 block_id)
1344 {
1345         struct drbd_socket *sock;
1346         struct p_block_ack *p;
1347 
1348         if (peer_device->device->state.conn < C_CONNECTED)
1349                 return -EIO;
1350 
1351         sock = &peer_device->connection->meta;
1352         p = drbd_prepare_command(peer_device, sock);
1353         if (!p)
1354                 return -EIO;
1355         p->sector = sector;
1356         p->block_id = block_id;
1357         p->blksize = blksize;
1358         p->seq_num = cpu_to_be32(atomic_inc_return(&peer_device->device->packet_seq));
1359         return drbd_send_command(peer_device, sock, cmd, sizeof(*p), NULL, 0);
1360 }
1361 
1362 /* dp->sector and dp->block_id already/still in network byte order,
1363  * data_size is payload size according to dp->head,
1364  * and may need to be corrected for digest size. */
1365 void drbd_send_ack_dp(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1366                       struct p_data *dp, int data_size)
1367 {
1368         if (peer_device->connection->peer_integrity_tfm)
1369                 data_size -= crypto_shash_digestsize(peer_device->connection->peer_integrity_tfm);
1370         _drbd_send_ack(peer_device, cmd, dp->sector, cpu_to_be32(data_size),
1371                        dp->block_id);
1372 }
1373 
1374 void drbd_send_ack_rp(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1375                       struct p_block_req *rp)
1376 {
1377         _drbd_send_ack(peer_device, cmd, rp->sector, rp->blksize, rp->block_id);
1378 }
1379 
1380 /**
1381  * drbd_send_ack() - Sends an ack packet
1382  * @device:     DRBD device
1383  * @cmd:        packet command code
1384  * @peer_req:   peer request
1385  */
1386 int drbd_send_ack(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1387                   struct drbd_peer_request *peer_req)
1388 {
1389         return _drbd_send_ack(peer_device, cmd,
1390                               cpu_to_be64(peer_req->i.sector),
1391                               cpu_to_be32(peer_req->i.size),
1392                               peer_req->block_id);
1393 }
1394 
1395 /* This function misuses the block_id field to signal if the blocks
1396  * are is sync or not. */
1397 int drbd_send_ack_ex(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1398                      sector_t sector, int blksize, u64 block_id)
1399 {
1400         return _drbd_send_ack(peer_device, cmd,
1401                               cpu_to_be64(sector),
1402                               cpu_to_be32(blksize),
1403                               cpu_to_be64(block_id));
1404 }
1405 
1406 int drbd_send_rs_deallocated(struct drbd_peer_device *peer_device,
1407                              struct drbd_peer_request *peer_req)
1408 {
1409         struct drbd_socket *sock;
1410         struct p_block_desc *p;
1411 
1412         sock = &peer_device->connection->data;
1413         p = drbd_prepare_command(peer_device, sock);
1414         if (!p)
1415                 return -EIO;
1416         p->sector = cpu_to_be64(peer_req->i.sector);
1417         p->blksize = cpu_to_be32(peer_req->i.size);
1418         p->pad = 0;
1419         return drbd_send_command(peer_device, sock, P_RS_DEALLOCATED, sizeof(*p), NULL, 0);
1420 }
1421 
1422 int drbd_send_drequest(struct drbd_peer_device *peer_device, int cmd,
1423                        sector_t sector, int size, u64 block_id)
1424 {
1425         struct drbd_socket *sock;
1426         struct p_block_req *p;
1427 
1428         sock = &peer_device->connection->data;
1429         p = drbd_prepare_command(peer_device, sock);
1430         if (!p)
1431                 return -EIO;
1432         p->sector = cpu_to_be64(sector);
1433         p->block_id = block_id;
1434         p->blksize = cpu_to_be32(size);
1435         return drbd_send_command(peer_device, sock, cmd, sizeof(*p), NULL, 0);
1436 }
1437 
1438 int drbd_send_drequest_csum(struct drbd_peer_device *peer_device, sector_t sector, int size,
1439                             void *digest, int digest_size, enum drbd_packet cmd)
1440 {
1441         struct drbd_socket *sock;
1442         struct p_block_req *p;
1443 
1444         /* FIXME: Put the digest into the preallocated socket buffer.  */
1445 
1446         sock = &peer_device->connection->data;
1447         p = drbd_prepare_command(peer_device, sock);
1448         if (!p)
1449                 return -EIO;
1450         p->sector = cpu_to_be64(sector);
1451         p->block_id = ID_SYNCER /* unused */;
1452         p->blksize = cpu_to_be32(size);
1453         return drbd_send_command(peer_device, sock, cmd, sizeof(*p), digest, digest_size);
1454 }
1455 
1456 int drbd_send_ov_request(struct drbd_peer_device *peer_device, sector_t sector, int size)
1457 {
1458         struct drbd_socket *sock;
1459         struct p_block_req *p;
1460 
1461         sock = &peer_device->connection->data;
1462         p = drbd_prepare_command(peer_device, sock);
1463         if (!p)
1464                 return -EIO;
1465         p->sector = cpu_to_be64(sector);
1466         p->block_id = ID_SYNCER /* unused */;
1467         p->blksize = cpu_to_be32(size);
1468         return drbd_send_command(peer_device, sock, P_OV_REQUEST, sizeof(*p), NULL, 0);
1469 }
1470 
1471 /* called on sndtimeo
1472  * returns false if we should retry,
1473  * true if we think connection is dead
1474  */
1475 static int we_should_drop_the_connection(struct drbd_connection *connection, struct socket *sock)
1476 {
1477         int drop_it;
1478         /* long elapsed = (long)(jiffies - device->last_received); */
1479 
1480         drop_it =   connection->meta.socket == sock
1481                 || !connection->ack_receiver.task
1482                 || get_t_state(&connection->ack_receiver) != RUNNING
1483                 || connection->cstate < C_WF_REPORT_PARAMS;
1484 
1485         if (drop_it)
1486                 return true;
1487 
1488         drop_it = !--connection->ko_count;
1489         if (!drop_it) {
1490                 drbd_err(connection, "[%s/%d] sock_sendmsg time expired, ko = %u\n",
1491                          current->comm, current->pid, connection->ko_count);
1492                 request_ping(connection);
1493         }
1494 
1495         return drop_it; /* && (device->state == R_PRIMARY) */;
1496 }
1497 
1498 static void drbd_update_congested(struct drbd_connection *connection)
1499 {
1500         struct sock *sk = connection->data.socket->sk;
1501         if (sk->sk_wmem_queued > sk->sk_sndbuf * 4 / 5)
1502                 set_bit(NET_CONGESTED, &connection->flags);
1503 }
1504 
1505 /* The idea of sendpage seems to be to put some kind of reference
1506  * to the page into the skb, and to hand it over to the NIC. In
1507  * this process get_page() gets called.
1508  *
1509  * As soon as the page was really sent over the network put_page()
1510  * gets called by some part of the network layer. [ NIC driver? ]
1511  *
1512  * [ get_page() / put_page() increment/decrement the count. If count
1513  *   reaches 0 the page will be freed. ]
1514  *
1515  * This works nicely with pages from FSs.
1516  * But this means that in protocol A we might signal IO completion too early!
1517  *
1518  * In order not to corrupt data during a resync we must make sure
1519  * that we do not reuse our own buffer pages (EEs) to early, therefore
1520  * we have the net_ee list.
1521  *
1522  * XFS seems to have problems, still, it submits pages with page_count == 0!
1523  * As a workaround, we disable sendpage on pages
1524  * with page_count == 0 or PageSlab.
1525  */
1526 static int _drbd_no_send_page(struct drbd_peer_device *peer_device, struct page *page,
1527                               int offset, size_t size, unsigned msg_flags)
1528 {
1529         struct socket *socket;
1530         void *addr;
1531         int err;
1532 
1533         socket = peer_device->connection->data.socket;
1534         addr = kmap(page) + offset;
1535         err = drbd_send_all(peer_device->connection, socket, addr, size, msg_flags);
1536         kunmap(page);
1537         if (!err)
1538                 peer_device->device->send_cnt += size >> 9;
1539         return err;
1540 }
1541 
1542 static int _drbd_send_page(struct drbd_peer_device *peer_device, struct page *page,
1543                     int offset, size_t size, unsigned msg_flags)
1544 {
1545         struct socket *socket = peer_device->connection->data.socket;
1546         int len = size;
1547         int err = -EIO;
1548 
1549         /* e.g. XFS meta- & log-data is in slab pages, which have a
1550          * page_count of 0 and/or have PageSlab() set.
1551          * we cannot use send_page for those, as that does get_page();
1552          * put_page(); and would cause either a VM_BUG directly, or
1553          * __page_cache_release a page that would actually still be referenced
1554          * by someone, leading to some obscure delayed Oops somewhere else. */
1555         if (drbd_disable_sendpage || (page_count(page) < 1) || PageSlab(page))
1556                 return _drbd_no_send_page(peer_device, page, offset, size, msg_flags);
1557 
1558         msg_flags |= MSG_NOSIGNAL;
1559         drbd_update_congested(peer_device->connection);
1560         do {
1561                 int sent;
1562 
1563                 sent = socket->ops->sendpage(socket, page, offset, len, msg_flags);
1564                 if (sent <= 0) {
1565                         if (sent == -EAGAIN) {
1566                                 if (we_should_drop_the_connection(peer_device->connection, socket))
1567                                         break;
1568                                 continue;
1569                         }
1570                         drbd_warn(peer_device->device, "%s: size=%d len=%d sent=%d\n",
1571                              __func__, (int)size, len, sent);
1572                         if (sent < 0)
1573                                 err = sent;
1574                         break;
1575                 }
1576                 len    -= sent;
1577                 offset += sent;
1578         } while (len > 0 /* THINK && device->cstate >= C_CONNECTED*/);
1579         clear_bit(NET_CONGESTED, &peer_device->connection->flags);
1580 
1581         if (len == 0) {
1582                 err = 0;
1583                 peer_device->device->send_cnt += size >> 9;
1584         }
1585         return err;
1586 }
1587 
1588 static int _drbd_send_bio(struct drbd_peer_device *peer_device, struct bio *bio)
1589 {
1590         struct bio_vec bvec;
1591         struct bvec_iter iter;
1592 
1593         /* hint all but last page with MSG_MORE */
1594         bio_for_each_segment(bvec, bio, iter) {
1595                 int err;
1596 
1597                 err = _drbd_no_send_page(peer_device, bvec.bv_page,
1598                                          bvec.bv_offset, bvec.bv_len,
1599                                          bio_iter_last(bvec, iter)
1600                                          ? 0 : MSG_MORE);
1601                 if (err)
1602                         return err;
1603                 /* REQ_OP_WRITE_SAME has only one segment */
1604                 if (bio_op(bio) == REQ_OP_WRITE_SAME)
1605                         break;
1606         }
1607         return 0;
1608 }
1609 
1610 static int _drbd_send_zc_bio(struct drbd_peer_device *peer_device, struct bio *bio)
1611 {
1612         struct bio_vec bvec;
1613         struct bvec_iter iter;
1614 
1615         /* hint all but last page with MSG_MORE */
1616         bio_for_each_segment(bvec, bio, iter) {
1617                 int err;
1618 
1619                 err = _drbd_send_page(peer_device, bvec.bv_page,
1620                                       bvec.bv_offset, bvec.bv_len,
1621                                       bio_iter_last(bvec, iter) ? 0 : MSG_MORE);
1622                 if (err)
1623                         return err;
1624                 /* REQ_OP_WRITE_SAME has only one segment */
1625                 if (bio_op(bio) == REQ_OP_WRITE_SAME)
1626                         break;
1627         }
1628         return 0;
1629 }
1630 
1631 static int _drbd_send_zc_ee(struct drbd_peer_device *peer_device,
1632                             struct drbd_peer_request *peer_req)
1633 {
1634         struct page *page = peer_req->pages;
1635         unsigned len = peer_req->i.size;
1636         int err;
1637 
1638         /* hint all but last page with MSG_MORE */
1639         page_chain_for_each(page) {
1640                 unsigned l = min_t(unsigned, len, PAGE_SIZE);
1641 
1642                 err = _drbd_send_page(peer_device, page, 0, l,
1643                                       page_chain_next(page) ? MSG_MORE : 0);
1644                 if (err)
1645                         return err;
1646                 len -= l;
1647         }
1648         return 0;
1649 }
1650 
1651 static u32 bio_flags_to_wire(struct drbd_connection *connection,
1652                              struct bio *bio)
1653 {
1654         if (connection->agreed_pro_version >= 95)
1655                 return  (bio->bi_opf & REQ_SYNC ? DP_RW_SYNC : 0) |
1656                         (bio->bi_opf & REQ_FUA ? DP_FUA : 0) |
1657                         (bio->bi_opf & REQ_PREFLUSH ? DP_FLUSH : 0) |
1658                         (bio_op(bio) == REQ_OP_WRITE_SAME ? DP_WSAME : 0) |
1659                         (bio_op(bio) == REQ_OP_DISCARD ? DP_DISCARD : 0) |
1660                         (bio_op(bio) == REQ_OP_WRITE_ZEROES ?
1661                           ((connection->agreed_features & DRBD_FF_WZEROES) ?
1662                            (DP_ZEROES |(!(bio->bi_opf & REQ_NOUNMAP) ? DP_DISCARD : 0))
1663                            : DP_DISCARD)
1664                         : 0);
1665         else
1666                 return bio->bi_opf & REQ_SYNC ? DP_RW_SYNC : 0;
1667 }
1668 
1669 /* Used to send write or TRIM aka REQ_OP_DISCARD requests
1670  * R_PRIMARY -> Peer    (P_DATA, P_TRIM)
1671  */
1672 int drbd_send_dblock(struct drbd_peer_device *peer_device, struct drbd_request *req)
1673 {
1674         struct drbd_device *device = peer_device->device;
1675         struct drbd_socket *sock;
1676         struct p_data *p;
1677         struct p_wsame *wsame = NULL;
1678         void *digest_out;
1679         unsigned int dp_flags = 0;
1680         int digest_size;
1681         int err;
1682 
1683         sock = &peer_device->connection->data;
1684         p = drbd_prepare_command(peer_device, sock);
1685         digest_size = peer_device->connection->integrity_tfm ?
1686                       crypto_shash_digestsize(peer_device->connection->integrity_tfm) : 0;
1687 
1688         if (!p)
1689                 return -EIO;
1690         p->sector = cpu_to_be64(req->i.sector);
1691         p->block_id = (unsigned long)req;
1692         p->seq_num = cpu_to_be32(atomic_inc_return(&device->packet_seq));
1693         dp_flags = bio_flags_to_wire(peer_device->connection, req->master_bio);
1694         if (device->state.conn >= C_SYNC_SOURCE &&
1695             device->state.conn <= C_PAUSED_SYNC_T)
1696                 dp_flags |= DP_MAY_SET_IN_SYNC;
1697         if (peer_device->connection->agreed_pro_version >= 100) {
1698                 if (req->rq_state & RQ_EXP_RECEIVE_ACK)
1699                         dp_flags |= DP_SEND_RECEIVE_ACK;
1700                 /* During resync, request an explicit write ack,
1701                  * even in protocol != C */
1702                 if (req->rq_state & RQ_EXP_WRITE_ACK
1703                 || (dp_flags & DP_MAY_SET_IN_SYNC))
1704                         dp_flags |= DP_SEND_WRITE_ACK;
1705         }
1706         p->dp_flags = cpu_to_be32(dp_flags);
1707 
1708         if (dp_flags & (DP_DISCARD|DP_ZEROES)) {
1709                 enum drbd_packet cmd = (dp_flags & DP_ZEROES) ? P_ZEROES : P_TRIM;
1710                 struct p_trim *t = (struct p_trim*)p;
1711                 t->size = cpu_to_be32(req->i.size);
1712                 err = __send_command(peer_device->connection, device->vnr, sock, cmd, sizeof(*t), NULL, 0);
1713                 goto out;
1714         }
1715         if (dp_flags & DP_WSAME) {
1716                 /* this will only work if DRBD_FF_WSAME is set AND the
1717                  * handshake agreed that all nodes and backend devices are
1718                  * WRITE_SAME capable and agree on logical_block_size */
1719                 wsame = (struct p_wsame*)p;
1720                 digest_out = wsame + 1;
1721                 wsame->size = cpu_to_be32(req->i.size);
1722         } else
1723                 digest_out = p + 1;
1724 
1725         /* our digest is still only over the payload.
1726          * TRIM does not carry any payload. */
1727         if (digest_size)
1728                 drbd_csum_bio(peer_device->connection->integrity_tfm, req->master_bio, digest_out);
1729         if (wsame) {
1730                 err =
1731                     __send_command(peer_device->connection, device->vnr, sock, P_WSAME,
1732                                    sizeof(*wsame) + digest_size, NULL,
1733                                    bio_iovec(req->master_bio).bv_len);
1734         } else
1735                 err =
1736                     __send_command(peer_device->connection, device->vnr, sock, P_DATA,
1737                                    sizeof(*p) + digest_size, NULL, req->i.size);
1738         if (!err) {
1739                 /* For protocol A, we have to memcpy the payload into
1740                  * socket buffers, as we may complete right away
1741                  * as soon as we handed it over to tcp, at which point the data
1742                  * pages may become invalid.
1743                  *
1744                  * For data-integrity enabled, we copy it as well, so we can be
1745                  * sure that even if the bio pages may still be modified, it
1746                  * won't change the data on the wire, thus if the digest checks
1747                  * out ok after sending on this side, but does not fit on the
1748                  * receiving side, we sure have detected corruption elsewhere.
1749                  */
1750                 if (!(req->rq_state & (RQ_EXP_RECEIVE_ACK | RQ_EXP_WRITE_ACK)) || digest_size)
1751                         err = _drbd_send_bio(peer_device, req->master_bio);
1752                 else
1753                         err = _drbd_send_zc_bio(peer_device, req->master_bio);
1754 
1755                 /* double check digest, sometimes buffers have been modified in flight. */
1756                 if (digest_size > 0 && digest_size <= 64) {
1757                         /* 64 byte, 512 bit, is the largest digest size
1758                          * currently supported in kernel crypto. */
1759                         unsigned char digest[64];
1760                         drbd_csum_bio(peer_device->connection->integrity_tfm, req->master_bio, digest);
1761                         if (memcmp(p + 1, digest, digest_size)) {
1762                                 drbd_warn(device,
1763                                         "Digest mismatch, buffer modified by upper layers during write: %llus +%u\n",
1764                                         (unsigned long long)req->i.sector, req->i.size);
1765                         }
1766                 } /* else if (digest_size > 64) {
1767                      ... Be noisy about digest too large ...
1768                 } */
1769         }
1770 out:
1771         mutex_unlock(&sock->mutex);  /* locked by drbd_prepare_command() */
1772 
1773         return err;
1774 }
1775 
1776 /* answer packet, used to send data back for read requests:
1777  *  Peer       -> (diskless) R_PRIMARY   (P_DATA_REPLY)
1778  *  C_SYNC_SOURCE -> C_SYNC_TARGET         (P_RS_DATA_REPLY)
1779  */
1780 int drbd_send_block(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
1781                     struct drbd_peer_request *peer_req)
1782 {
1783         struct drbd_device *device = peer_device->device;
1784         struct drbd_socket *sock;
1785         struct p_data *p;
1786         int err;
1787         int digest_size;
1788 
1789         sock = &peer_device->connection->data;
1790         p = drbd_prepare_command(peer_device, sock);
1791 
1792         digest_size = peer_device->connection->integrity_tfm ?
1793                       crypto_shash_digestsize(peer_device->connection->integrity_tfm) : 0;
1794 
1795         if (!p)
1796                 return -EIO;
1797         p->sector = cpu_to_be64(peer_req->i.sector);
1798         p->block_id = peer_req->block_id;
1799         p->seq_num = 0;  /* unused */
1800         p->dp_flags = 0;
1801         if (digest_size)
1802                 drbd_csum_ee(peer_device->connection->integrity_tfm, peer_req, p + 1);
1803         err = __send_command(peer_device->connection, device->vnr, sock, cmd, sizeof(*p) + digest_size, NULL, peer_req->i.size);
1804         if (!err)
1805                 err = _drbd_send_zc_ee(peer_device, peer_req);
1806         mutex_unlock(&sock->mutex);  /* locked by drbd_prepare_command() */
1807 
1808         return err;
1809 }
1810 
1811 int drbd_send_out_of_sync(struct drbd_peer_device *peer_device, struct drbd_request *req)
1812 {
1813         struct drbd_socket *sock;
1814         struct p_block_desc *p;
1815 
1816         sock = &peer_device->connection->data;
1817         p = drbd_prepare_command(peer_device, sock);
1818         if (!p)
1819                 return -EIO;
1820         p->sector = cpu_to_be64(req->i.sector);
1821         p->blksize = cpu_to_be32(req->i.size);
1822         return drbd_send_command(peer_device, sock, P_OUT_OF_SYNC, sizeof(*p), NULL, 0);
1823 }
1824 
1825 /*
1826   drbd_send distinguishes two cases:
1827 
1828   Packets sent via the data socket "sock"
1829   and packets sent via the meta data socket "msock"
1830 
1831                     sock                      msock
1832   -----------------+-------------------------+------------------------------
1833   timeout           conf.timeout / 2          conf.timeout / 2
1834   timeout action    send a ping via msock     Abort communication
1835                                               and close all sockets
1836 */
1837 
1838 /*
1839  * you must have down()ed the appropriate [m]sock_mutex elsewhere!
1840  */
1841 int drbd_send(struct drbd_connection *connection, struct socket *sock,
1842               void *buf, size_t size, unsigned msg_flags)
1843 {
1844         struct kvec iov = {.iov_base = buf, .iov_len = size};
1845         struct msghdr msg = {.msg_flags = msg_flags | MSG_NOSIGNAL};
1846         int rv, sent = 0;
1847 
1848         if (!sock)
1849                 return -EBADR;
1850 
1851         /* THINK  if (signal_pending) return ... ? */
1852 
1853         iov_iter_kvec(&msg.msg_iter, WRITE, &iov, 1, size);
1854 
1855         if (sock == connection->data.socket) {
1856                 rcu_read_lock();
1857                 connection->ko_count = rcu_dereference(connection->net_conf)->ko_count;
1858                 rcu_read_unlock();
1859                 drbd_update_congested(connection);
1860         }
1861         do {
1862                 rv = sock_sendmsg(sock, &msg);
1863                 if (rv == -EAGAIN) {
1864                         if (we_should_drop_the_connection(connection, sock))
1865                                 break;
1866                         else
1867                                 continue;
1868                 }
1869                 if (rv == -EINTR) {
1870                         flush_signals(current);
1871                         rv = 0;
1872                 }
1873                 if (rv < 0)
1874                         break;
1875                 sent += rv;
1876         } while (sent < size);
1877 
1878         if (sock == connection->data.socket)
1879                 clear_bit(NET_CONGESTED, &connection->flags);
1880 
1881         if (rv <= 0) {
1882                 if (rv != -EAGAIN) {
1883                         drbd_err(connection, "%s_sendmsg returned %d\n",
1884                                  sock == connection->meta.socket ? "msock" : "sock",
1885                                  rv);
1886                         conn_request_state(connection, NS(conn, C_BROKEN_PIPE), CS_HARD);
1887                 } else
1888                         conn_request_state(connection, NS(conn, C_TIMEOUT), CS_HARD);
1889         }
1890 
1891         return sent;
1892 }
1893 
1894 /**
1895  * drbd_send_all  -  Send an entire buffer
1896  *
1897  * Returns 0 upon success and a negative error value otherwise.
1898  */
1899 int drbd_send_all(struct drbd_connection *connection, struct socket *sock, void *buffer,
1900                   size_t size, unsigned msg_flags)
1901 {
1902         int err;
1903 
1904         err = drbd_send(connection, sock, buffer, size, msg_flags);
1905         if (err < 0)
1906                 return err;
1907         if (err != size)
1908                 return -EIO;
1909         return 0;
1910 }
1911 
1912 static int drbd_open(struct block_device *bdev, fmode_t mode)
1913 {
1914         struct drbd_device *device = bdev->bd_disk->private_data;
1915         unsigned long flags;
1916         int rv = 0;
1917 
1918         mutex_lock(&drbd_main_mutex);
1919         spin_lock_irqsave(&device->resource->req_lock, flags);
1920         /* to have a stable device->state.role
1921          * and no race with updating open_cnt */
1922 
1923         if (device->state.role != R_PRIMARY) {
1924                 if (mode & FMODE_WRITE)
1925                         rv = -EROFS;
1926                 else if (!drbd_allow_oos)
1927                         rv = -EMEDIUMTYPE;
1928         }
1929 
1930         if (!rv)
1931                 device->open_cnt++;
1932         spin_unlock_irqrestore(&device->resource->req_lock, flags);
1933         mutex_unlock(&drbd_main_mutex);
1934 
1935         return rv;
1936 }
1937 
1938 static void drbd_release(struct gendisk *gd, fmode_t mode)
1939 {
1940         struct drbd_device *device = gd->private_data;
1941         mutex_lock(&drbd_main_mutex);
1942         device->open_cnt--;
1943         mutex_unlock(&drbd_main_mutex);
1944 }
1945 
1946 /* need to hold resource->req_lock */
1947 void drbd_queue_unplug(struct drbd_device *device)
1948 {
1949         if (device->state.pdsk >= D_INCONSISTENT && device->state.conn >= C_CONNECTED) {
1950                 D_ASSERT(device, device->state.role == R_PRIMARY);
1951                 if (test_and_clear_bit(UNPLUG_REMOTE, &device->flags)) {
1952                         drbd_queue_work_if_unqueued(
1953                                 &first_peer_device(device)->connection->sender_work,
1954                                 &device->unplug_work);
1955                 }
1956         }
1957 }
1958 
1959 static void drbd_set_defaults(struct drbd_device *device)
1960 {
1961         /* Beware! The actual layout differs
1962          * between big endian and little endian */
1963         device->state = (union drbd_dev_state) {
1964                 { .role = R_SECONDARY,
1965                   .peer = R_UNKNOWN,
1966                   .conn = C_STANDALONE,
1967                   .disk = D_DISKLESS,
1968                   .pdsk = D_UNKNOWN,
1969                 } };
1970 }
1971 
1972 void drbd_init_set_defaults(struct drbd_device *device)
1973 {
1974         /* the memset(,0,) did most of this.
1975          * note: only assignments, no allocation in here */
1976 
1977         drbd_set_defaults(device);
1978 
1979         atomic_set(&device->ap_bio_cnt, 0);
1980         atomic_set(&device->ap_actlog_cnt, 0);
1981         atomic_set(&device->ap_pending_cnt, 0);
1982         atomic_set(&device->rs_pending_cnt, 0);
1983         atomic_set(&device->unacked_cnt, 0);
1984         atomic_set(&device->local_cnt, 0);
1985         atomic_set(&device->pp_in_use_by_net, 0);
1986         atomic_set(&device->rs_sect_in, 0);
1987         atomic_set(&device->rs_sect_ev, 0);
1988         atomic_set(&device->ap_in_flight, 0);
1989         atomic_set(&device->md_io.in_use, 0);
1990 
1991         mutex_init(&device->own_state_mutex);
1992         device->state_mutex = &device->own_state_mutex;
1993 
1994         spin_lock_init(&device->al_lock);
1995         spin_lock_init(&device->peer_seq_lock);
1996 
1997         INIT_LIST_HEAD(&device->active_ee);
1998         INIT_LIST_HEAD(&device->sync_ee);
1999         INIT_LIST_HEAD(&device->done_ee);
2000         INIT_LIST_HEAD(&device->read_ee);
2001         INIT_LIST_HEAD(&device->net_ee);
2002         INIT_LIST_HEAD(&device->resync_reads);
2003         INIT_LIST_HEAD(&device->resync_work.list);
2004         INIT_LIST_HEAD(&device->unplug_work.list);
2005         INIT_LIST_HEAD(&device->bm_io_work.w.list);
2006         INIT_LIST_HEAD(&device->pending_master_completion[0]);
2007         INIT_LIST_HEAD(&device->pending_master_completion[1]);
2008         INIT_LIST_HEAD(&device->pending_completion[0]);
2009         INIT_LIST_HEAD(&device->pending_completion[1]);
2010 
2011         device->resync_work.cb  = w_resync_timer;
2012         device->unplug_work.cb  = w_send_write_hint;
2013         device->bm_io_work.w.cb = w_bitmap_io;
2014 
2015         timer_setup(&device->resync_timer, resync_timer_fn, 0);
2016         timer_setup(&device->md_sync_timer, md_sync_timer_fn, 0);
2017         timer_setup(&device->start_resync_timer, start_resync_timer_fn, 0);
2018         timer_setup(&device->request_timer, request_timer_fn, 0);
2019 
2020         init_waitqueue_head(&device->misc_wait);
2021         init_waitqueue_head(&device->state_wait);
2022         init_waitqueue_head(&device->ee_wait);
2023         init_waitqueue_head(&device->al_wait);
2024         init_waitqueue_head(&device->seq_wait);
2025 
2026         device->resync_wenr = LC_FREE;
2027         device->peer_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
2028         device->local_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
2029 }
2030 
2031 static void _drbd_set_my_capacity(struct drbd_device *device, sector_t size)
2032 {
2033         /* set_capacity(device->this_bdev->bd_disk, size); */
2034         set_capacity(device->vdisk, size);
2035         device->this_bdev->bd_inode->i_size = (loff_t)size << 9;
2036 }
2037 
2038 void drbd_set_my_capacity(struct drbd_device *device, sector_t size)
2039 {
2040         char ppb[10];
2041         _drbd_set_my_capacity(device, size);
2042         drbd_info(device, "size = %s (%llu KB)\n",
2043                 ppsize(ppb, size>>1), (unsigned long long)size>>1);
2044 }
2045 
2046 void drbd_device_cleanup(struct drbd_device *device)
2047 {
2048         int i;
2049         if (first_peer_device(device)->connection->receiver.t_state != NONE)
2050                 drbd_err(device, "ASSERT FAILED: receiver t_state == %d expected 0.\n",
2051                                 first_peer_device(device)->connection->receiver.t_state);
2052 
2053         device->al_writ_cnt  =
2054         device->bm_writ_cnt  =
2055         device->read_cnt     =
2056         device->recv_cnt     =
2057         device->send_cnt     =
2058         device->writ_cnt     =
2059         device->p_size       =
2060         device->rs_start     =
2061         device->rs_total     =
2062         device->rs_failed    = 0;
2063         device->rs_last_events = 0;
2064         device->rs_last_sect_ev = 0;
2065         for (i = 0; i < DRBD_SYNC_MARKS; i++) {
2066                 device->rs_mark_left[i] = 0;
2067                 device->rs_mark_time[i] = 0;
2068         }
2069         D_ASSERT(device, first_peer_device(device)->connection->net_conf == NULL);
2070 
2071         _drbd_set_my_capacity(device, 0);
2072         if (device->bitmap) {
2073                 /* maybe never allocated. */
2074                 drbd_bm_resize(device, 0, 1);
2075                 drbd_bm_cleanup(device);
2076         }
2077 
2078         drbd_backing_dev_free(device, device->ldev);
2079         device->ldev = NULL;
2080 
2081         clear_bit(AL_SUSPENDED, &device->flags);
2082 
2083         D_ASSERT(device, list_empty(&device->active_ee));
2084         D_ASSERT(device, list_empty(&device->sync_ee));
2085         D_ASSERT(device, list_empty(&device->done_ee));
2086         D_ASSERT(device, list_empty(&device->read_ee));
2087         D_ASSERT(device, list_empty(&device->net_ee));
2088         D_ASSERT(device, list_empty(&device->resync_reads));
2089         D_ASSERT(device, list_empty(&first_peer_device(device)->connection->sender_work.q));
2090         D_ASSERT(device, list_empty(&device->resync_work.list));
2091         D_ASSERT(device, list_empty(&device->unplug_work.list));
2092 
2093         drbd_set_defaults(device);
2094 }
2095 
2096 
2097 static void drbd_destroy_mempools(void)
2098 {
2099         struct page *page;
2100 
2101         while (drbd_pp_pool) {
2102                 page = drbd_pp_pool;
2103                 drbd_pp_pool = (struct page *)page_private(page);
2104                 __free_page(page);
2105                 drbd_pp_vacant--;
2106         }
2107 
2108         /* D_ASSERT(device, atomic_read(&drbd_pp_vacant)==0); */
2109 
2110         bioset_exit(&drbd_io_bio_set);
2111         bioset_exit(&drbd_md_io_bio_set);
2112         mempool_exit(&drbd_md_io_page_pool);
2113         mempool_exit(&drbd_ee_mempool);
2114         mempool_exit(&drbd_request_mempool);
2115         kmem_cache_destroy(drbd_ee_cache);
2116         kmem_cache_destroy(drbd_request_cache);
2117         kmem_cache_destroy(drbd_bm_ext_cache);
2118         kmem_cache_destroy(drbd_al_ext_cache);
2119 
2120         drbd_ee_cache        = NULL;
2121         drbd_request_cache   = NULL;
2122         drbd_bm_ext_cache    = NULL;
2123         drbd_al_ext_cache    = NULL;
2124 
2125         return;
2126 }
2127 
2128 static int drbd_create_mempools(void)
2129 {
2130         struct page *page;
2131         const int number = (DRBD_MAX_BIO_SIZE/PAGE_SIZE) * drbd_minor_count;
2132         int i, ret;
2133 
2134         /* caches */
2135         drbd_request_cache = kmem_cache_create(
2136                 "drbd_req", sizeof(struct drbd_request), 0, 0, NULL);
2137         if (drbd_request_cache == NULL)
2138                 goto Enomem;
2139 
2140         drbd_ee_cache = kmem_cache_create(
2141                 "drbd_ee", sizeof(struct drbd_peer_request), 0, 0, NULL);
2142         if (drbd_ee_cache == NULL)
2143                 goto Enomem;
2144 
2145         drbd_bm_ext_cache = kmem_cache_create(
2146                 "drbd_bm", sizeof(struct bm_extent), 0, 0, NULL);
2147         if (drbd_bm_ext_cache == NULL)
2148                 goto Enomem;
2149 
2150         drbd_al_ext_cache = kmem_cache_create(
2151                 "drbd_al", sizeof(struct lc_element), 0, 0, NULL);
2152         if (drbd_al_ext_cache == NULL)
2153                 goto Enomem;
2154 
2155         /* mempools */
2156         ret = bioset_init(&drbd_io_bio_set, BIO_POOL_SIZE, 0, 0);
2157         if (ret)
2158                 goto Enomem;
2159 
2160         ret = bioset_init(&drbd_md_io_bio_set, DRBD_MIN_POOL_PAGES, 0,
2161                           BIOSET_NEED_BVECS);
2162         if (ret)
2163                 goto Enomem;
2164 
2165         ret = mempool_init_page_pool(&drbd_md_io_page_pool, DRBD_MIN_POOL_PAGES, 0);
2166         if (ret)
2167                 goto Enomem;
2168 
2169         ret = mempool_init_slab_pool(&drbd_request_mempool, number,
2170                                      drbd_request_cache);
2171         if (ret)
2172                 goto Enomem;
2173 
2174         ret = mempool_init_slab_pool(&drbd_ee_mempool, number, drbd_ee_cache);
2175         if (ret)
2176                 goto Enomem;
2177 
2178         /* drbd's page pool */
2179         spin_lock_init(&drbd_pp_lock);
2180 
2181         for (i = 0; i < number; i++) {
2182                 page = alloc_page(GFP_HIGHUSER);
2183                 if (!page)
2184                         goto Enomem;
2185                 set_page_private(page, (unsigned long)drbd_pp_pool);
2186                 drbd_pp_pool = page;
2187         }
2188         drbd_pp_vacant = number;
2189 
2190         return 0;
2191 
2192 Enomem:
2193         drbd_destroy_mempools(); /* in case we allocated some */
2194         return -ENOMEM;
2195 }
2196 
2197 static void drbd_release_all_peer_reqs(struct drbd_device *device)
2198 {
2199         int rr;
2200 
2201         rr = drbd_free_peer_reqs(device, &device->active_ee);
2202         if (rr)
2203                 drbd_err(device, "%d EEs in active list found!\n", rr);
2204 
2205         rr = drbd_free_peer_reqs(device, &device->sync_ee);
2206         if (rr)
2207                 drbd_err(device, "%d EEs in sync list found!\n", rr);
2208 
2209         rr = drbd_free_peer_reqs(device, &device->read_ee);
2210         if (rr)
2211                 drbd_err(device, "%d EEs in read list found!\n", rr);
2212 
2213         rr = drbd_free_peer_reqs(device, &device->done_ee);
2214         if (rr)
2215                 drbd_err(device, "%d EEs in done list found!\n", rr);
2216 
2217         rr = drbd_free_peer_reqs(device, &device->net_ee);
2218         if (rr)
2219                 drbd_err(device, "%d EEs in net list found!\n", rr);
2220 }
2221 
2222 /* caution. no locking. */
2223 void drbd_destroy_device(struct kref *kref)
2224 {
2225         struct drbd_device *device = container_of(kref, struct drbd_device, kref);
2226         struct drbd_resource *resource = device->resource;
2227         struct drbd_peer_device *peer_device, *tmp_peer_device;
2228 
2229         del_timer_sync(&device->request_timer);
2230 
2231         /* paranoia asserts */
2232         D_ASSERT(device, device->open_cnt == 0);
2233         /* end paranoia asserts */
2234 
2235         /* cleanup stuff that may have been allocated during
2236          * device (re-)configuration or state changes */
2237 
2238         if (device->this_bdev)
2239                 bdput(device->this_bdev);
2240 
2241         drbd_backing_dev_free(device, device->ldev);
2242         device->ldev = NULL;
2243 
2244         drbd_release_all_peer_reqs(device);
2245 
2246         lc_destroy(device->act_log);
2247         lc_destroy(device->resync);
2248 
2249         kfree(device->p_uuid);
2250         /* device->p_uuid = NULL; */
2251 
2252         if (device->bitmap) /* should no longer be there. */
2253                 drbd_bm_cleanup(device);
2254         __free_page(device->md_io.page);
2255         put_disk(device->vdisk);
2256         blk_cleanup_queue(device->rq_queue);
2257         kfree(device->rs_plan_s);
2258 
2259         /* not for_each_connection(connection, resource):
2260          * those may have been cleaned up and disassociated already.
2261          */
2262         for_each_peer_device_safe(peer_device, tmp_peer_device, device) {
2263                 kref_put(&peer_device->connection->kref, drbd_destroy_connection);
2264                 kfree(peer_device);
2265         }
2266         memset(device, 0xfd, sizeof(*device));
2267         kfree(device);
2268         kref_put(&resource->kref, drbd_destroy_resource);
2269 }
2270 
2271 /* One global retry thread, if we need to push back some bio and have it
2272  * reinserted through our make request function.
2273  */
2274 static struct retry_worker {
2275         struct workqueue_struct *wq;
2276         struct work_struct worker;
2277 
2278         spinlock_t lock;
2279         struct list_head writes;
2280 } retry;
2281 
2282 static void do_retry(struct work_struct *ws)
2283 {
2284         struct retry_worker *retry = container_of(ws, struct retry_worker, worker);
2285         LIST_HEAD(writes);
2286         struct drbd_request *req, *tmp;
2287 
2288         spin_lock_irq(&retry->lock);
2289         list_splice_init(&retry->writes, &writes);
2290         spin_unlock_irq(&retry->lock);
2291 
2292         list_for_each_entry_safe(req, tmp, &writes, tl_requests) {
2293                 struct drbd_device *device = req->device;
2294                 struct bio *bio = req->master_bio;
2295                 unsigned long start_jif = req->start_jif;
2296                 bool expected;
2297 
2298                 expected =
2299                         expect(atomic_read(&req->completion_ref) == 0) &&
2300                         expect(req->rq_state & RQ_POSTPONED) &&
2301                         expect((req->rq_state & RQ_LOCAL_PENDING) == 0 ||
2302                                 (req->rq_state & RQ_LOCAL_ABORTED) != 0);
2303 
2304                 if (!expected)
2305                         drbd_err(device, "req=%p completion_ref=%d rq_state=%x\n",
2306                                 req, atomic_read(&req->completion_ref),
2307                                 req->rq_state);
2308 
2309                 /* We still need to put one kref associated with the
2310                  * "completion_ref" going zero in the code path that queued it
2311                  * here.  The request object may still be referenced by a
2312                  * frozen local req->private_bio, in case we force-detached.
2313                  */
2314                 kref_put(&req->kref, drbd_req_destroy);
2315 
2316                 /* A single suspended or otherwise blocking device may stall
2317                  * all others as well.  Fortunately, this code path is to
2318                  * recover from a situation that "should not happen":
2319                  * concurrent writes in multi-primary setup.
2320                  * In a "normal" lifecycle, this workqueue is supposed to be
2321                  * destroyed without ever doing anything.
2322                  * If it turns out to be an issue anyways, we can do per
2323                  * resource (replication group) or per device (minor) retry
2324                  * workqueues instead.
2325                  */
2326 
2327                 /* We are not just doing generic_make_request(),
2328                  * as we want to keep the start_time information. */
2329                 inc_ap_bio(device);
2330                 __drbd_make_request(device, bio, start_jif);
2331         }
2332 }
2333 
2334 /* called via drbd_req_put_completion_ref(),
2335  * holds resource->req_lock */
2336 void drbd_restart_request(struct drbd_request *req)
2337 {
2338         unsigned long flags;
2339         spin_lock_irqsave(&retry.lock, flags);
2340         list_move_tail(&req->tl_requests, &retry.writes);
2341         spin_unlock_irqrestore(&retry.lock, flags);
2342 
2343         /* Drop the extra reference that would otherwise
2344          * have been dropped by complete_master_bio.
2345          * do_retry() needs to grab a new one. */
2346         dec_ap_bio(req->device);
2347 
2348         queue_work(retry.wq, &retry.worker);
2349 }
2350 
2351 void drbd_destroy_resource(struct kref *kref)
2352 {
2353         struct drbd_resource *resource =
2354                 container_of(kref, struct drbd_resource, kref);
2355 
2356         idr_destroy(&resource->devices);
2357         free_cpumask_var(resource->cpu_mask);
2358         kfree(resource->name);
2359         memset(resource, 0xf2, sizeof(*resource));
2360         kfree(resource);
2361 }
2362 
2363 void drbd_free_resource(struct drbd_resource *resource)
2364 {
2365         struct drbd_connection *connection, *tmp;
2366 
2367         for_each_connection_safe(connection, tmp, resource) {
2368                 list_del(&connection->connections);
2369                 drbd_debugfs_connection_cleanup(connection);
2370                 kref_put(&connection->kref, drbd_destroy_connection);
2371         }
2372         drbd_debugfs_resource_cleanup(resource);
2373         kref_put(&resource->kref, drbd_destroy_resource);
2374 }
2375 
2376 static void drbd_cleanup(void)
2377 {
2378         unsigned int i;
2379         struct drbd_device *device;
2380         struct drbd_resource *resource, *tmp;
2381 
2382         /* first remove proc,
2383          * drbdsetup uses it's presence to detect
2384          * whether DRBD is loaded.
2385          * If we would get stuck in proc removal,
2386          * but have netlink already deregistered,
2387          * some drbdsetup commands may wait forever
2388          * for an answer.
2389          */
2390         if (drbd_proc)
2391                 remove_proc_entry("drbd", NULL);
2392 
2393         if (retry.wq)
2394                 destroy_workqueue(retry.wq);
2395 
2396         drbd_genl_unregister();
2397 
2398         idr_for_each_entry(&drbd_devices, device, i)
2399                 drbd_delete_device(device);
2400 
2401         /* not _rcu since, no other updater anymore. Genl already unregistered */
2402         for_each_resource_safe(resource, tmp, &drbd_resources) {
2403                 list_del(&resource->resources);
2404                 drbd_free_resource(resource);
2405         }
2406 
2407         drbd_debugfs_cleanup();
2408 
2409         drbd_destroy_mempools();
2410         unregister_blkdev(DRBD_MAJOR, "drbd");
2411 
2412         idr_destroy(&drbd_devices);
2413 
2414         pr_info("module cleanup done.\n");
2415 }
2416 
2417 /**
2418  * drbd_congested() - Callback for the flusher thread
2419  * @congested_data:     User data
2420  * @bdi_bits:           Bits the BDI flusher thread is currently interested in
2421  *
2422  * Returns 1<<WB_async_congested and/or 1<<WB_sync_congested if we are congested.
2423  */
2424 static int drbd_congested(void *congested_data, int bdi_bits)
2425 {
2426         struct drbd_device *device = congested_data;
2427         struct request_queue *q;
2428         char reason = '-';
2429         int r = 0;
2430 
2431         if (!may_inc_ap_bio(device)) {
2432                 /* DRBD has frozen IO */
2433                 r = bdi_bits;
2434                 reason = 'd';
2435                 goto out;
2436         }
2437 
2438         if (test_bit(CALLBACK_PENDING, &first_peer_device(device)->connection->flags)) {
2439                 r |= (1 << WB_async_congested);
2440                 /* Without good local data, we would need to read from remote,
2441                  * and that would need the worker thread as well, which is
2442                  * currently blocked waiting for that usermode helper to
2443                  * finish.
2444                  */
2445                 if (!get_ldev_if_state(device, D_UP_TO_DATE))
2446                         r |= (1 << WB_sync_congested);
2447                 else
2448                         put_ldev(device);
2449                 r &= bdi_bits;
2450                 reason = 'c';
2451                 goto out;
2452         }
2453 
2454         if (get_ldev(device)) {
2455                 q = bdev_get_queue(device->ldev->backing_bdev);
2456                 r = bdi_congested(q->backing_dev_info, bdi_bits);
2457                 put_ldev(device);
2458                 if (r)
2459                         reason = 'b';
2460         }
2461 
2462         if (bdi_bits & (1 << WB_async_congested) &&
2463             test_bit(NET_CONGESTED, &first_peer_device(device)->connection->flags)) {
2464                 r |= (1 << WB_async_congested);
2465                 reason = reason == 'b' ? 'a' : 'n';
2466         }
2467 
2468 out:
2469         device->congestion_reason = reason;
2470         return r;
2471 }
2472 
2473 static void drbd_init_workqueue(struct drbd_work_queue* wq)
2474 {
2475         spin_lock_init(&wq->q_lock);
2476         INIT_LIST_HEAD(&wq->q);
2477         init_waitqueue_head(&wq->q_wait);
2478 }
2479 
2480 struct completion_work {
2481         struct drbd_work w;
2482         struct completion done;
2483 };
2484 
2485 static int w_complete(struct drbd_work *w, int cancel)
2486 {
2487         struct completion_work *completion_work =
2488                 container_of(w, struct completion_work, w);
2489 
2490         complete(&completion_work->done);
2491         return 0;
2492 }
2493 
2494 void drbd_flush_workqueue(struct drbd_work_queue *work_queue)
2495 {
2496         struct completion_work completion_work;
2497 
2498         completion_work.w.cb = w_complete;
2499         init_completion(&completion_work.done);
2500         drbd_queue_work(work_queue, &completion_work.w);
2501         wait_for_completion(&completion_work.done);
2502 }
2503 
2504 struct drbd_resource *drbd_find_resource(const char *name)
2505 {
2506         struct drbd_resource *resource;
2507 
2508         if (!name || !name[0])
2509                 return NULL;
2510 
2511         rcu_read_lock();
2512         for_each_resource_rcu(resource, &drbd_resources) {
2513                 if (!strcmp(resource->name, name)) {
2514                         kref_get(&resource->kref);
2515                         goto found;
2516                 }
2517         }
2518         resource = NULL;
2519 found:
2520         rcu_read_unlock();
2521         return resource;
2522 }
2523 
2524 struct drbd_connection *conn_get_by_addrs(void *my_addr, int my_addr_len,
2525                                      void *peer_addr, int peer_addr_len)
2526 {
2527         struct drbd_resource *resource;
2528         struct drbd_connection *connection;
2529 
2530         rcu_read_lock();
2531         for_each_resource_rcu(resource, &drbd_resources) {
2532                 for_each_connection_rcu(connection, resource) {
2533                         if (connection->my_addr_len == my_addr_len &&
2534                             connection->peer_addr_len == peer_addr_len &&
2535                             !memcmp(&connection->my_addr, my_addr, my_addr_len) &&
2536                             !memcmp(&connection->peer_addr, peer_addr, peer_addr_len)) {
2537                                 kref_get(&connection->kref);
2538                                 goto found;
2539                         }
2540                 }
2541         }
2542         connection = NULL;
2543 found:
2544         rcu_read_unlock();
2545         return connection;
2546 }
2547 
2548 static int drbd_alloc_socket(struct drbd_socket *socket)
2549 {
2550         socket->rbuf = (void *) __get_free_page(GFP_KERNEL);
2551         if (!socket->rbuf)
2552                 return -ENOMEM;
2553         socket->sbuf = (void *) __get_free_page(GFP_KERNEL);
2554         if (!socket->sbuf)
2555                 return -ENOMEM;
2556         return 0;
2557 }
2558 
2559 static void drbd_free_socket(struct drbd_socket *socket)
2560 {
2561         free_page((unsigned long) socket->sbuf);
2562         free_page((unsigned long) socket->rbuf);
2563 }
2564 
2565 void conn_free_crypto(struct drbd_connection *connection)
2566 {
2567         drbd_free_sock(connection);
2568 
2569         crypto_free_shash(connection->csums_tfm);
2570         crypto_free_shash(connection->verify_tfm);
2571         crypto_free_shash(connection->cram_hmac_tfm);
2572         crypto_free_shash(connection->integrity_tfm);
2573         crypto_free_shash(connection->peer_integrity_tfm);
2574         kfree(connection->int_dig_in);
2575         kfree(connection->int_dig_vv);
2576 
2577         connection->csums_tfm = NULL;
2578         connection->verify_tfm = NULL;
2579         connection->cram_hmac_tfm = NULL;
2580         connection->integrity_tfm = NULL;
2581         connection->peer_integrity_tfm = NULL;
2582         connection->int_dig_in = NULL;
2583         connection->int_dig_vv = NULL;
2584 }
2585 
2586 int set_resource_options(struct drbd_resource *resource, struct res_opts *res_opts)
2587 {
2588         struct drbd_connection *connection;
2589         cpumask_var_t new_cpu_mask;
2590         int err;
2591 
2592         if (!zalloc_cpumask_var(&new_cpu_mask, GFP_KERNEL))
2593                 return -ENOMEM;
2594 
2595         /* silently ignore cpu mask on UP kernel */
2596         if (nr_cpu_ids > 1 && res_opts->cpu_mask[0] != 0) {
2597                 err = bitmap_parse(res_opts->cpu_mask, DRBD_CPU_MASK_SIZE,
2598                                    cpumask_bits(new_cpu_mask), nr_cpu_ids);
2599                 if (err == -EOVERFLOW) {
2600                         /* So what. mask it out. */
2601                         cpumask_var_t tmp_cpu_mask;
2602                         if (zalloc_cpumask_var(&tmp_cpu_mask, GFP_KERNEL)) {
2603                                 cpumask_setall(tmp_cpu_mask);
2604                                 cpumask_and(new_cpu_mask, new_cpu_mask, tmp_cpu_mask);
2605                                 drbd_warn(resource, "Overflow in bitmap_parse(%.12s%s), truncating to %u bits\n",
2606                                         res_opts->cpu_mask,
2607                                         strlen(res_opts->cpu_mask) > 12 ? "..." : "",
2608                                         nr_cpu_ids);
2609                                 free_cpumask_var(tmp_cpu_mask);
2610                                 err = 0;
2611                         }
2612                 }
2613                 if (err) {
2614                         drbd_warn(resource, "bitmap_parse() failed with %d\n", err);
2615                         /* retcode = ERR_CPU_MASK_PARSE; */
2616                         goto fail;
2617                 }
2618         }
2619         resource->res_opts = *res_opts;
2620         if (cpumask_empty(new_cpu_mask))
2621                 drbd_calc_cpu_mask(&new_cpu_mask);
2622         if (!cpumask_equal(resource->cpu_mask, new_cpu_mask)) {
2623                 cpumask_copy(resource->cpu_mask, new_cpu_mask);
2624                 for_each_connection_rcu(connection, resource) {
2625                         connection->receiver.reset_cpu_mask = 1;
2626                         connection->ack_receiver.reset_cpu_mask = 1;
2627                         connection->worker.reset_cpu_mask = 1;
2628                 }
2629         }
2630         err = 0;
2631 
2632 fail:
2633         free_cpumask_var(new_cpu_mask);
2634         return err;
2635 
2636 }
2637 
2638 struct drbd_resource *drbd_create_resource(const char *name)
2639 {
2640         struct drbd_resource *resource;
2641 
2642         resource = kzalloc(sizeof(struct drbd_resource), GFP_KERNEL);
2643         if (!resource)
2644                 goto fail;
2645         resource->name = kstrdup(name, GFP_KERNEL);
2646         if (!resource->name)
2647                 goto fail_free_resource;
2648         if (!zalloc_cpumask_var(&resource->cpu_mask, GFP_KERNEL))
2649                 goto fail_free_name;
2650         kref_init(&resource->kref);
2651         idr_init(&resource->devices);
2652         INIT_LIST_HEAD(&resource->connections);
2653         resource->write_ordering = WO_BDEV_FLUSH;
2654         list_add_tail_rcu(&resource->resources, &drbd_resources);
2655         mutex_init(&resource->conf_update);
2656         mutex_init(&resource->adm_mutex);
2657         spin_lock_init(&resource->req_lock);
2658         drbd_debugfs_resource_add(resource);
2659         return resource;
2660 
2661 fail_free_name:
2662         kfree(resource->name);
2663 fail_free_resource:
2664         kfree(resource);
2665 fail:
2666         return NULL;
2667 }
2668 
2669 /* caller must be under adm_mutex */
2670 struct drbd_connection *conn_create(const char *name, struct res_opts *res_opts)
2671 {
2672         struct drbd_resource *resource;
2673         struct drbd_connection *connection;
2674 
2675         connection = kzalloc(sizeof(struct drbd_connection), GFP_KERNEL);
2676         if (!connection)
2677                 return NULL;
2678 
2679         if (drbd_alloc_socket(&connection->data))
2680                 goto fail;
2681         if (drbd_alloc_socket(&connection->meta))
2682                 goto fail;
2683 
2684         connection->current_epoch = kzalloc(sizeof(struct drbd_epoch), GFP_KERNEL);
2685         if (!connection->current_epoch)
2686                 goto fail;
2687 
2688         INIT_LIST_HEAD(&connection->transfer_log);
2689 
2690         INIT_LIST_HEAD(&connection->current_epoch->list);
2691         connection->epochs = 1;
2692         spin_lock_init(&connection->epoch_lock);
2693 
2694         connection->send.seen_any_write_yet = false;
2695         connection->send.current_epoch_nr = 0;
2696         connection->send.current_epoch_writes = 0;
2697 
2698         resource = drbd_create_resource(name);
2699         if (!resource)
2700                 goto fail;
2701 
2702         connection->cstate = C_STANDALONE;
2703         mutex_init(&connection->cstate_mutex);
2704         init_waitqueue_head(&connection->ping_wait);
2705         idr_init(&connection->peer_devices);
2706 
2707         drbd_init_workqueue(&connection->sender_work);
2708         mutex_init(&connection->data.mutex);
2709         mutex_init(&connection->meta.mutex);
2710 
2711         drbd_thread_init(resource, &connection->receiver, drbd_receiver, "receiver");
2712         connection->receiver.connection = connection;
2713         drbd_thread_init(resource, &connection->worker, drbd_worker, "worker");
2714         connection->worker.connection = connection;
2715         drbd_thread_init(resource, &connection->ack_receiver, drbd_ack_receiver, "ack_recv");
2716         connection->ack_receiver.connection = connection;
2717 
2718         kref_init(&connection->kref);
2719 
2720         connection->resource = resource;
2721 
2722         if (set_resource_options(resource, res_opts))
2723                 goto fail_resource;
2724 
2725         kref_get(&resource->kref);
2726         list_add_tail_rcu(&connection->connections, &resource->connections);
2727         drbd_debugfs_connection_add(connection);
2728         return connection;
2729 
2730 fail_resource:
2731         list_del(&resource->resources);
2732         drbd_free_resource(resource);
2733 fail:
2734         kfree(connection->current_epoch);
2735         drbd_free_socket(&connection->meta);
2736         drbd_free_socket(&connection->data);
2737         kfree(connection);
2738         return NULL;
2739 }
2740 
2741 void drbd_destroy_connection(struct kref *kref)
2742 {
2743         struct drbd_connection *connection = container_of(kref, struct drbd_connection, kref);
2744         struct drbd_resource *resource = connection->resource;
2745 
2746         if (atomic_read(&connection->current_epoch->epoch_size) !=  0)
2747                 drbd_err(connection, "epoch_size:%d\n", atomic_read(&connection->current_epoch->epoch_size));
2748         kfree(connection->current_epoch);
2749 
2750         idr_destroy(&connection->peer_devices);
2751 
2752         drbd_free_socket(&connection->meta);
2753         drbd_free_socket(&connection->data);
2754         kfree(connection->int_dig_in);
2755         kfree(connection->int_dig_vv);
2756         memset(connection, 0xfc, sizeof(*connection));
2757         kfree(connection);
2758         kref_put(&resource->kref, drbd_destroy_resource);
2759 }
2760 
2761 static int init_submitter(struct drbd_device *device)
2762 {
2763         /* opencoded create_singlethread_workqueue(),
2764          * to be able to say "drbd%d", ..., minor */
2765         device->submit.wq =
2766                 alloc_ordered_workqueue("drbd%u_submit", WQ_MEM_RECLAIM, device->minor);
2767         if (!device->submit.wq)
2768                 return -ENOMEM;
2769 
2770         INIT_WORK(&device->submit.worker, do_submit);
2771         INIT_LIST_HEAD(&device->submit.writes);
2772         return 0;
2773 }
2774 
2775 enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsigned int minor)
2776 {
2777         struct drbd_resource *resource = adm_ctx->resource;
2778         struct drbd_connection *connection;
2779         struct drbd_device *device;
2780         struct drbd_peer_device *peer_device, *tmp_peer_device;
2781         struct gendisk *disk;
2782         struct request_queue *q;
2783         int id;
2784         int vnr = adm_ctx->volume;
2785         enum drbd_ret_code err = ERR_NOMEM;
2786 
2787         device = minor_to_device(minor);
2788         if (device)
2789                 return ERR_MINOR_OR_VOLUME_EXISTS;
2790 
2791         /* GFP_KERNEL, we are outside of all write-out paths */
2792         device = kzalloc(sizeof(struct drbd_device), GFP_KERNEL);
2793         if (!device)
2794                 return ERR_NOMEM;
2795         kref_init(&device->kref);
2796 
2797         kref_get(&resource->kref);
2798         device->resource = resource;
2799         device->minor = minor;
2800         device->vnr = vnr;
2801 
2802         drbd_init_set_defaults(device);
2803 
2804         q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE);
2805         if (!q)
2806                 goto out_no_q;
2807         device->rq_queue = q;
2808         q->queuedata   = device;
2809 
2810         disk = alloc_disk(1);
2811         if (!disk)
2812                 goto out_no_disk;
2813         device->vdisk = disk;
2814 
2815         set_disk_ro(disk, true);
2816 
2817         disk->queue = q;
2818         disk->major = DRBD_MAJOR;
2819         disk->first_minor = minor;
2820         disk->fops = &drbd_ops;
2821         sprintf(disk->disk_name, "drbd%d", minor);
2822         disk->private_data = device;
2823 
2824         device->this_bdev = bdget(MKDEV(DRBD_MAJOR, minor));
2825         /* we have no partitions. we contain only ourselves. */
2826         device->this_bdev->bd_contains = device->this_bdev;
2827 
2828         q->backing_dev_info->congested_fn = drbd_congested;
2829         q->backing_dev_info->congested_data = device;
2830 
2831         blk_queue_make_request(q, drbd_make_request);
2832         blk_queue_write_cache(q, true, true);
2833         /* Setting the max_hw_sectors to an odd value of 8kibyte here
2834            This triggers a max_bio_size message upon first attach or connect */
2835         blk_queue_max_hw_sectors(q, DRBD_MAX_BIO_SIZE_SAFE >> 8);
2836 
2837         device->md_io.page = alloc_page(GFP_KERNEL);
2838         if (!device->md_io.page)
2839                 goto out_no_io_page;
2840 
2841         if (drbd_bm_init(device))
2842                 goto out_no_bitmap;
2843         device->read_requests = RB_ROOT;
2844         device->write_requests = RB_ROOT;
2845 
2846         id = idr_alloc(&drbd_devices, device, minor, minor + 1, GFP_KERNEL);
2847         if (id < 0) {
2848                 if (id == -ENOSPC)
2849                         err = ERR_MINOR_OR_VOLUME_EXISTS;
2850                 goto out_no_minor_idr;
2851         }
2852         kref_get(&device->kref);
2853 
2854         id = idr_alloc(&resource->devices, device, vnr, vnr + 1, GFP_KERNEL);
2855         if (id < 0) {
2856                 if (id == -ENOSPC)
2857                         err = ERR_MINOR_OR_VOLUME_EXISTS;
2858                 goto out_idr_remove_minor;
2859         }
2860         kref_get(&device->kref);
2861 
2862         INIT_LIST_HEAD(&device->peer_devices);
2863         INIT_LIST_HEAD(&device->pending_bitmap_io);
2864         for_each_connection(connection, resource) {
2865                 peer_device = kzalloc(sizeof(struct drbd_peer_device), GFP_KERNEL);
2866                 if (!peer_device)
2867                         goto out_idr_remove_from_resource;
2868                 peer_device->connection = connection;
2869                 peer_device->device = device;
2870 
2871                 list_add(&peer_device->peer_devices, &device->peer_devices);
2872                 kref_get(&device->kref);
2873 
2874                 id = idr_alloc(&connection->peer_devices, peer_device, vnr, vnr + 1, GFP_KERNEL);
2875                 if (id < 0) {
2876                         if (id == -ENOSPC)
2877                                 err = ERR_INVALID_REQUEST;
2878                         goto out_idr_remove_from_resource;
2879                 }
2880                 kref_get(&connection->kref);
2881                 INIT_WORK(&peer_device->send_acks_work, drbd_send_acks_wf);
2882         }
2883 
2884         if (init_submitter(device)) {
2885                 err = ERR_NOMEM;
2886                 goto out_idr_remove_vol;
2887         }
2888 
2889         add_disk(disk);
2890 
2891         /* inherit the connection state */
2892         device->state.conn = first_connection(resource)->cstate;
2893         if (device->state.conn == C_WF_REPORT_PARAMS) {
2894                 for_each_peer_device(peer_device, device)
2895                         drbd_connected(peer_device);
2896         }
2897         /* move to create_peer_device() */
2898         for_each_peer_device(peer_device, device)
2899                 drbd_debugfs_peer_device_add(peer_device);
2900         drbd_debugfs_device_add(device);
2901         return NO_ERROR;
2902 
2903 out_idr_remove_vol:
2904         idr_remove(&connection->peer_devices, vnr);
2905 out_idr_remove_from_resource:
2906         for_each_connection(connection, resource) {
2907                 peer_device = idr_remove(&connection->peer_devices, vnr);
2908                 if (peer_device)
2909                         kref_put(&connection->kref, drbd_destroy_connection);
2910         }
2911         for_each_peer_device_safe(peer_device, tmp_peer_device, device) {
2912                 list_del(&peer_device->peer_devices);
2913                 kfree(peer_device);
2914         }
2915         idr_remove(&resource->devices, vnr);
2916 out_idr_remove_minor:
2917         idr_remove(&drbd_devices, minor);
2918         synchronize_rcu();
2919 out_no_minor_idr:
2920         drbd_bm_cleanup(device);
2921 out_no_bitmap:
2922         __free_page(device->md_io.page);
2923 out_no_io_page:
2924         put_disk(disk);
2925 out_no_disk:
2926         blk_cleanup_queue(q);
2927 out_no_q:
2928         kref_put(&resource->kref, drbd_destroy_resource);
2929         kfree(device);
2930         return err;
2931 }
2932 
2933 void drbd_delete_device(struct drbd_device *device)
2934 {
2935         struct drbd_resource *resource = device->resource;
2936         struct drbd_connection *connection;
2937         struct drbd_peer_device *peer_device;
2938 
2939         /* move to free_peer_device() */
2940         for_each_peer_device(peer_device, device)
2941                 drbd_debugfs_peer_device_cleanup(peer_device);
2942         drbd_debugfs_device_cleanup(device);
2943         for_each_connection(connection, resource) {
2944                 idr_remove(&connection->peer_devices, device->vnr);
2945                 kref_put(&device->kref, drbd_destroy_device);
2946         }
2947         idr_remove(&resource->devices, device->vnr);
2948         kref_put(&device->kref, drbd_destroy_device);
2949         idr_remove(&drbd_devices, device_to_minor(device));
2950         kref_put(&device->kref, drbd_destroy_device);
2951         del_gendisk(device->vdisk);
2952         synchronize_rcu();
2953         kref_put(&device->kref, drbd_destroy_device);
2954 }
2955 
2956 static int __init drbd_init(void)
2957 {
2958         int err;
2959 
2960         if (drbd_minor_count < DRBD_MINOR_COUNT_MIN || drbd_minor_count > DRBD_MINOR_COUNT_MAX) {
2961                 pr_err("invalid minor_count (%d)\n", drbd_minor_count);
2962 #ifdef MODULE
2963                 return -EINVAL;
2964 #else
2965                 drbd_minor_count = DRBD_MINOR_COUNT_DEF;
2966 #endif
2967         }
2968 
2969         err = register_blkdev(DRBD_MAJOR, "drbd");
2970         if (err) {
2971                 pr_err("unable to register block device major %d\n",
2972                        DRBD_MAJOR);
2973                 return err;
2974         }
2975 
2976         /*
2977          * allocate all necessary structs
2978          */
2979         init_waitqueue_head(&drbd_pp_wait);
2980 
2981         drbd_proc = NULL; /* play safe for drbd_cleanup */
2982         idr_init(&drbd_devices);
2983 
2984         mutex_init(&resources_mutex);
2985         INIT_LIST_HEAD(&drbd_resources);
2986 
2987         err = drbd_genl_register();
2988         if (err) {
2989                 pr_err("unable to register generic netlink family\n");
2990                 goto fail;
2991         }
2992 
2993         err = drbd_create_mempools();
2994         if (err)
2995                 goto fail;
2996 
2997         err = -ENOMEM;
2998         drbd_proc = proc_create_single("drbd", S_IFREG | 0444 , NULL, drbd_seq_show);
2999         if (!drbd_proc) {
3000                 pr_err("unable to register proc file\n");
3001                 goto fail;
3002         }
3003 
3004         retry.wq = create_singlethread_workqueue("drbd-reissue");
3005         if (!retry.wq) {
3006                 pr_err("unable to create retry workqueue\n");
3007                 goto fail;
3008         }
3009         INIT_WORK(&retry.worker, do_retry);
3010         spin_lock_init(&retry.lock);
3011         INIT_LIST_HEAD(&retry.writes);
3012 
3013         drbd_debugfs_init();
3014 
3015         pr_info("initialized. "
3016                "Version: " REL_VERSION " (api:%d/proto:%d-%d)\n",
3017                API_VERSION, PRO_VERSION_MIN, PRO_VERSION_MAX);
3018         pr_info("%s\n", drbd_buildtag());
3019         pr_info("registered as block device major %d\n", DRBD_MAJOR);
3020         return 0; /* Success! */
3021 
3022 fail:
3023         drbd_cleanup();
3024         if (err == -ENOMEM)
3025                 pr_err("ran out of memory\n");
3026         else
3027                 pr_err("initialization failure\n");
3028         return err;
3029 }
3030 
3031 static void drbd_free_one_sock(struct drbd_socket *ds)
3032 {
3033         struct socket *s;
3034         mutex_lock(&ds->mutex);
3035         s = ds->socket;
3036         ds->socket = NULL;
3037         mutex_unlock(&ds->mutex);
3038         if (s) {
3039                 /* so debugfs does not need to mutex_lock() */
3040                 synchronize_rcu();
3041                 kernel_sock_shutdown(s, SHUT_RDWR);
3042                 sock_release(s);
3043         }
3044 }
3045 
3046 void drbd_free_sock(struct drbd_connection *connection)
3047 {
3048         if (connection->data.socket)
3049                 drbd_free_one_sock(&connection->data);
3050         if (connection->meta.socket)
3051                 drbd_free_one_sock(&connection->meta);
3052 }
3053 
3054 /* meta data management */
3055 
3056 void conn_md_sync(struct drbd_connection *connection)
3057 {
3058         struct drbd_peer_device *peer_device;
3059         int vnr;
3060 
3061         rcu_read_lock();
3062         idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
3063                 struct drbd_device *device = peer_device->device;
3064 
3065                 kref_get(&device->kref);
3066                 rcu_read_unlock();
3067                 drbd_md_sync(device);
3068                 kref_put(&device->kref, drbd_destroy_device);
3069                 rcu_read_lock();
3070         }
3071         rcu_read_unlock();
3072 }
3073 
3074 /* aligned 4kByte */
3075 struct meta_data_on_disk {
3076         u64 la_size_sect;      /* last agreed size. */
3077         u64 uuid[UI_SIZE];   /* UUIDs. */
3078         u64 device_uuid;
3079         u64 reserved_u64_1;
3080         u32 flags;             /* MDF */
3081         u32 magic;
3082         u32 md_size_sect;
3083         u32 al_offset;         /* offset to this block */
3084         u32 al_nr_extents;     /* important for restoring the AL (userspace) */
3085               /* `-- act_log->nr_elements <-- ldev->dc.al_extents */
3086         u32 bm_offset;         /* offset to the bitmap, from here */
3087         u32 bm_bytes_per_bit;  /* BM_BLOCK_SIZE */
3088         u32 la_peer_max_bio_size;   /* last peer max_bio_size */
3089 
3090         /* see al_tr_number_to_on_disk_sector() */
3091         u32 al_stripes;
3092         u32 al_stripe_size_4k;
3093 
3094         u8 reserved_u8[4096 - (7*8 + 10*4)];
3095 } __packed;
3096 
3097 
3098 
3099 void drbd_md_write(struct drbd_device *device, void *b)
3100 {
3101         struct meta_data_on_disk *buffer = b;
3102         sector_t sector;
3103         int i;
3104 
3105         memset(buffer, 0, sizeof(*buffer));
3106 
3107         buffer->la_size_sect = cpu_to_be64(drbd_get_capacity(device->this_bdev));
3108         for (i = UI_CURRENT; i < UI_SIZE; i++)
3109                 buffer->uuid[i] = cpu_to_be64(device->ldev->md.uuid[i]);
3110         buffer->flags = cpu_to_be32(device->ldev->md.flags);
3111         buffer->magic = cpu_to_be32(DRBD_MD_MAGIC_84_UNCLEAN);
3112 
3113         buffer->md_size_sect  = cpu_to_be32(device->ldev->md.md_size_sect);
3114         buffer->al_offset     = cpu_to_be32(device->ldev->md.al_offset);
3115         buffer->al_nr_extents = cpu_to_be32(device->act_log->nr_elements);
3116         buffer->bm_bytes_per_bit = cpu_to_be32(BM_BLOCK_SIZE);
3117         buffer->device_uuid = cpu_to_be64(device->ldev->md.device_uuid);
3118 
3119         buffer->bm_offset = cpu_to_be32(device->ldev->md.bm_offset);
3120         buffer->la_peer_max_bio_size = cpu_to_be32(device->peer_max_bio_size);
3121 
3122         buffer->al_stripes = cpu_to_be32(device->ldev->md.al_stripes);
3123         buffer->al_stripe_size_4k = cpu_to_be32(device->ldev->md.al_stripe_size_4k);
3124 
3125         D_ASSERT(device, drbd_md_ss(device->ldev) == device->ldev->md.md_offset);
3126         sector = device->ldev->md.md_offset;
3127 
3128         if (drbd_md_sync_page_io(device, device->ldev, sector, REQ_OP_WRITE)) {
3129                 /* this was a try anyways ... */
3130                 drbd_err(device, "meta data update failed!\n");
3131                 drbd_chk_io_error(device, 1, DRBD_META_IO_ERROR);
3132         }
3133 }
3134 
3135 /**
3136  * drbd_md_sync() - Writes the meta data super block if the MD_DIRTY flag bit is set
3137  * @device:     DRBD device.
3138  */
3139 void drbd_md_sync(struct drbd_device *device)
3140 {
3141         struct meta_data_on_disk *buffer;
3142 
3143         /* Don't accidentally change the DRBD meta data layout. */
3144         BUILD_BUG_ON(UI_SIZE != 4);
3145         BUILD_BUG_ON(sizeof(struct meta_data_on_disk) != 4096);
3146 
3147         del_timer(&device->md_sync_timer);
3148         /* timer may be rearmed by drbd_md_mark_dirty() now. */
3149         if (!test_and_clear_bit(MD_DIRTY, &device->flags))
3150                 return;
3151 
3152         /* We use here D_FAILED and not D_ATTACHING because we try to write
3153          * metadata even if we detach due to a disk failure! */
3154         if (!get_ldev_if_state(device, D_FAILED))
3155                 return;
3156 
3157         buffer = drbd_md_get_buffer(device, __func__);
3158         if (!buffer)
3159                 goto out;
3160 
3161         drbd_md_write(device, buffer);
3162 
3163         /* Update device->ldev->md.la_size_sect,
3164          * since we updated it on metadata. */
3165         device->ldev->md.la_size_sect = drbd_get_capacity(device->this_bdev);
3166 
3167         drbd_md_put_buffer(device);
3168 out:
3169         put_ldev(device);
3170 }
3171 
3172 static int check_activity_log_stripe_size(struct drbd_device *device,
3173                 struct meta_data_on_disk *on_disk,
3174                 struct drbd_md *in_core)
3175 {
3176         u32 al_stripes = be32_to_cpu(on_disk->al_stripes);
3177         u32 al_stripe_size_4k = be32_to_cpu(on_disk->al_stripe_size_4k);
3178         u64 al_size_4k;
3179 
3180         /* both not set: default to old fixed size activity log */
3181         if (al_stripes == 0 && al_stripe_size_4k == 0) {
3182                 al_stripes = 1;
3183                 al_stripe_size_4k = MD_32kB_SECT/8;
3184         }
3185 
3186         /* some paranoia plausibility checks */
3187 
3188         /* we need both values to be set */
3189         if (al_stripes == 0 || al_stripe_size_4k == 0)
3190                 goto err;
3191 
3192         al_size_4k = (u64)al_stripes * al_stripe_size_4k;
3193 
3194         /* Upper limit of activity log area, to avoid potential overflow
3195          * problems in al_tr_number_to_on_disk_sector(). As right now, more
3196          * than 72 * 4k blocks total only increases the amount of history,
3197          * limiting this arbitrarily to 16 GB is not a real limitation ;-)  */
3198         if (al_size_4k > (16 * 1024 * 1024/4))
3199                 goto err;
3200 
3201         /* Lower limit: we need at least 8 transaction slots (32kB)
3202          * to not break existing setups */
3203         if (al_size_4k < MD_32kB_SECT/8)
3204                 goto err;
3205 
3206         in_core->al_stripe_size_4k = al_stripe_size_4k;
3207         in_core->al_stripes = al_stripes;
3208         in_core->al_size_4k = al_size_4k;
3209 
3210         return 0;
3211 err:
3212         drbd_err(device, "invalid activity log striping: al_stripes=%u, al_stripe_size_4k=%u\n",
3213                         al_stripes, al_stripe_size_4k);
3214         return -EINVAL;
3215 }
3216 
3217 static int check_offsets_and_sizes(struct drbd_device *device, struct drbd_backing_dev *bdev)
3218 {
3219         sector_t capacity = drbd_get_capacity(bdev->md_bdev);
3220         struct drbd_md *in_core = &bdev->md;
3221         s32 on_disk_al_sect;
3222         s32 on_disk_bm_sect;
3223 
3224         /* The on-disk size of the activity log, calculated from offsets, and
3225          * the size of the activity log calculated from the stripe settings,
3226          * should match.
3227          * Though we could relax this a bit: it is ok, if the striped activity log
3228          * fits in the available on-disk activity log size.
3229          * Right now, that would break how resize is implemented.
3230          * TODO: make drbd_determine_dev_size() (and the drbdmeta tool) aware
3231          * of possible unused padding space in the on disk layout. */
3232         if (in_core->al_offset < 0) {
3233                 if (in_core->bm_offset > in_core->al_offset)
3234                         goto err;
3235                 on_disk_al_sect = -in_core->al_offset;
3236                 on_disk_bm_sect = in_core->al_offset - in_core->bm_offset;
3237         } else {
3238                 if (in_core->al_offset != MD_4kB_SECT)
3239                         goto err;
3240                 if (in_core->bm_offset < in_core->al_offset + in_core->al_size_4k * MD_4kB_SECT)
3241                         goto err;
3242 
3243                 on_disk_al_sect = in_core->bm_offset - MD_4kB_SECT;
3244                 on_disk_bm_sect = in_core->md_size_sect - in_core->bm_offset;
3245         }
3246 
3247         /* old fixed size meta data is exactly that: fixed. */
3248         if (in_core->meta_dev_idx >= 0) {
3249                 if (in_core->md_size_sect != MD_128MB_SECT
3250                 ||  in_core->al_offset != MD_4kB_SECT
3251                 ||  in_core->bm_offset != MD_4kB_SECT + MD_32kB_SECT
3252                 ||  in_core->al_stripes != 1
3253                 ||  in_core->al_stripe_size_4k != MD_32kB_SECT/8)
3254                         goto err;
3255         }
3256 
3257         if (capacity < in_core->md_size_sect)
3258                 goto err;
3259         if (capacity - in_core->md_size_sect < drbd_md_first_sector(bdev))
3260                 goto err;
3261 
3262         /* should be aligned, and at least 32k */
3263         if ((on_disk_al_sect & 7) || (on_disk_al_sect < MD_32kB_SECT))
3264                 goto err;
3265 
3266         /* should fit (for now: exactly) into the available on-disk space;
3267          * overflow prevention is in check_activity_log_stripe_size() above. */
3268         if (on_disk_al_sect != in_core->al_size_4k * MD_4kB_SECT)
3269                 goto err;
3270 
3271         /* again, should be aligned */
3272         if (in_core->bm_offset & 7)
3273                 goto err;
3274 
3275         /* FIXME check for device grow with flex external meta data? */
3276 
3277         /* can the available bitmap space cover the last agreed device size? */
3278         if (on_disk_bm_sect < (in_core->la_size_sect+7)/MD_4kB_SECT/8/512)
3279                 goto err;
3280 
3281         return 0;
3282 
3283 err:
3284         drbd_err(device, "meta data offsets don't make sense: idx=%d "
3285                         "al_s=%u, al_sz4k=%u, al_offset=%d, bm_offset=%d, "
3286                         "md_size_sect=%u, la_size=%llu, md_capacity=%llu\n",
3287                         in_core->meta_dev_idx,
3288                         in_core->al_stripes, in_core->al_stripe_size_4k,
3289                         in_core->al_offset, in_core->bm_offset, in_core->md_size_sect,
3290                         (unsigned long long)in_core->la_size_sect,
3291                         (unsigned long long)capacity);
3292 
3293         return -EINVAL;
3294 }
3295 
3296 
3297 /**
3298  * drbd_md_read() - Reads in the meta data super block
3299  * @device:     DRBD device.
3300  * @bdev:       Device from which the meta data should be read in.
3301  *
3302  * Return NO_ERROR on success, and an enum drbd_ret_code in case
3303  * something goes wrong.
3304  *
3305  * Called exactly once during drbd_adm_attach(), while still being D_DISKLESS,
3306  * even before @bdev is assigned to @device->ldev.
3307  */
3308 int drbd_md_read(struct drbd_device *device, struct drbd_backing_dev *bdev)
3309 {
3310         struct meta_data_on_disk *buffer;
3311         u32 magic, flags;
3312         int i, rv = NO_ERROR;
3313 
3314         if (device->state.disk != D_DISKLESS)
3315                 return ERR_DISK_CONFIGURED;
3316 
3317         buffer = drbd_md_get_buffer(device, __func__);
3318         if (!buffer)
3319                 return ERR_NOMEM;
3320 
3321         /* First, figure out where our meta data superblock is located,
3322          * and read it. */
3323         bdev->md.meta_dev_idx = bdev->disk_conf->meta_dev_idx;
3324         bdev->md.md_offset = drbd_md_ss(bdev);
3325         /* Even for (flexible or indexed) external meta data,
3326          * initially restrict us to the 4k superblock for now.
3327          * Affects the paranoia out-of-range access check in drbd_md_sync_page_io(). */
3328         bdev->md.md_size_sect = 8;
3329 
3330         if (drbd_md_sync_page_io(device, bdev, bdev->md.md_offset,
3331                                  REQ_OP_READ)) {
3332                 /* NOTE: can't do normal error processing here as this is
3333                    called BEFORE disk is attached */
3334                 drbd_err(device, "Error while reading metadata.\n");
3335                 rv = ERR_IO_MD_DISK;
3336                 goto err;
3337         }
3338 
3339         magic = be32_to_cpu(buffer->magic);
3340         flags = be32_to_cpu(buffer->flags);
3341         if (magic == DRBD_MD_MAGIC_84_UNCLEAN ||
3342             (magic == DRBD_MD_MAGIC_08 && !(flags & MDF_AL_CLEAN))) {
3343                         /* btw: that's Activity Log clean, not "all" clean. */
3344                 drbd_err(device, "Found unclean meta data. Did you \"drbdadm apply-al\"?\n");
3345                 rv = ERR_MD_UNCLEAN;
3346                 goto err;
3347         }
3348 
3349         rv = ERR_MD_INVALID;
3350         if (magic != DRBD_MD_MAGIC_08) {
3351                 if (magic == DRBD_MD_MAGIC_07)
3352                         drbd_err(device, "Found old (0.7) meta data magic. Did you \"drbdadm create-md\"?\n");
3353                 else
3354                         drbd_err(device, "Meta data magic not found. Did you \"drbdadm create-md\"?\n");
3355                 goto err;
3356         }
3357 
3358         if (be32_to_cpu(buffer->bm_bytes_per_bit) != BM_BLOCK_SIZE) {
3359                 drbd_err(device, "unexpected bm_bytes_per_bit: %u (expected %u)\n",
3360                     be32_to_cpu(buffer->bm_bytes_per_bit), BM_BLOCK_SIZE);
3361                 goto err;
3362         }
3363 
3364 
3365         /* convert to in_core endian */
3366         bdev->md.la_size_sect = be64_to_cpu(buffer->la_size_sect);
3367         for (i = UI_CURRENT; i < UI_SIZE; i++)
3368                 bdev->md.uuid[i] = be64_to_cpu(buffer->uuid[i]);
3369         bdev->md.flags = be32_to_cpu(buffer->flags);
3370         bdev->md.device_uuid = be64_to_cpu(buffer->device_uuid);
3371 
3372         bdev->md.md_size_sect = be32_to_cpu(buffer->md_size_sect);
3373         bdev->md.al_offset = be32_to_cpu(buffer->al_offset);
3374         bdev->md.bm_offset = be32_to_cpu(buffer->bm_offset);
3375 
3376         if (check_activity_log_stripe_size(device, buffer, &bdev->md))
3377                 goto err;
3378         if (check_offsets_and_sizes(device, bdev))
3379                 goto err;
3380 
3381         if (be32_to_cpu(buffer->bm_offset) != bdev->md.bm_offset) {
3382                 drbd_err(device, "unexpected bm_offset: %d (expected %d)\n",
3383                     be32_to_cpu(buffer->bm_offset), bdev->md.bm_offset);
3384                 goto err;
3385         }
3386         if (be32_to_cpu(buffer->md_size_sect) != bdev->md.md_size_sect) {
3387                 drbd_err(device, "unexpected md_size: %u (expected %u)\n",
3388                     be32_to_cpu(buffer->md_size_sect), bdev->md.md_size_sect);
3389                 goto err;
3390         }
3391 
3392         rv = NO_ERROR;
3393 
3394         spin_lock_irq(&device->resource->req_lock);
3395         if (device->state.conn < C_CONNECTED) {
3396                 unsigned int peer;
3397                 peer = be32_to_cpu(buffer->la_peer_max_bio_size);
3398                 peer = max(peer, DRBD_MAX_BIO_SIZE_SAFE);
3399                 device->peer_max_bio_size = peer;
3400         }
3401         spin_unlock_irq(&device->resource->req_lock);
3402 
3403  err:
3404         drbd_md_put_buffer(device);
3405 
3406         return rv;
3407 }
3408 
3409 /**
3410  * drbd_md_mark_dirty() - Mark meta data super block as dirty
3411  * @device:     DRBD device.
3412  *
3413  * Call this function if you change anything that should be written to
3414  * the meta-data super block. This function sets MD_DIRTY, and starts a
3415  * timer that ensures that within five seconds you have to call drbd_md_sync().
3416  */
3417 #ifdef DEBUG
3418 void drbd_md_mark_dirty_(struct drbd_device *device, unsigned int line, const char *func)
3419 {
3420         if (!test_and_set_bit(MD_DIRTY, &device->flags)) {
3421                 mod_timer(&device->md_sync_timer, jiffies + HZ);
3422                 device->last_md_mark_dirty.line = line;
3423                 device->last_md_mark_dirty.func = func;
3424         }
3425 }
3426 #else
3427 void drbd_md_mark_dirty(struct drbd_device *device)
3428 {
3429         if (!test_and_set_bit(MD_DIRTY, &device->flags))
3430                 mod_timer(&device->md_sync_timer, jiffies + 5*HZ);
3431 }
3432 #endif
3433 
3434 void drbd_uuid_move_history(struct drbd_device *device) __must_hold(local)
3435 {
3436         int i;
3437 
3438         for (i = UI_HISTORY_START; i < UI_HISTORY_END; i++)
3439                 device->ldev->md.uuid[i+1] = device->ldev->md.uuid[i];
3440 }
3441 
3442 void __drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local)
3443 {
3444         if (idx == UI_CURRENT) {
3445                 if (device->state.role == R_PRIMARY)
3446                         val |= 1;
3447                 else
3448                         val &= ~((u64)1);
3449 
3450                 drbd_set_ed_uuid(device, val);
3451         }
3452 
3453         device->ldev->md.uuid[idx] = val;
3454         drbd_md_mark_dirty(device);
3455 }
3456 
3457 void _drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local)
3458 {
3459         unsigned long flags;
3460         spin_lock_irqsave(&device->ldev->md.uuid_lock, flags);
3461         __drbd_uuid_set(device, idx, val);
3462         spin_unlock_irqrestore(&device->ldev->md.uuid_lock, flags);
3463 }
3464 
3465 void drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local)
3466 {
3467         unsigned long flags;
3468         spin_lock_irqsave(&device->ldev->md.uuid_lock, flags);
3469         if (device->ldev->md.uuid[idx]) {
3470                 drbd_uuid_move_history(device);
3471                 device->ldev->md.uuid[UI_HISTORY_START] = device->ldev->md.uuid[idx];
3472         }
3473         __drbd_uuid_set(device, idx, val);
3474         spin_unlock_irqrestore(&device->ldev->md.uuid_lock, flags);
3475 }
3476 
3477 /**
3478  * drbd_uuid_new_current() - Creates a new current UUID
3479  * @device:     DRBD device.
3480  *
3481  * Creates a new current UUID, and rotates the old current UUID into
3482  * the bitmap slot. Causes an incremental resync upon next connect.
3483  */
3484 void drbd_uuid_new_current(struct drbd_device *device) __must_hold(local)
3485 {
3486         u64 val;
3487         unsigned long long bm_uuid;
3488 
3489         get_random_bytes(&val, sizeof(u64));
3490 
3491         spin_lock_irq(&device->ldev->md.uuid_lock);
3492         bm_uuid = device->ldev->md.uuid[UI_BITMAP];
3493 
3494         if (bm_uuid)
3495                 drbd_warn(device, "bm UUID was already set: %llX\n", bm_uuid);
3496 
3497         device->ldev->md.uuid[UI_BITMAP] = device->ldev->md.uuid[UI_CURRENT];
3498         __drbd_uuid_set(device, UI_CURRENT, val);
3499         spin_unlock_irq(&device->ldev->md.uuid_lock);
3500 
3501         drbd_print_uuids(device, "new current UUID");
3502         /* get it to stable storage _now_ */
3503         drbd_md_sync(device);
3504 }
3505 
3506 void drbd_uuid_set_bm(struct drbd_device *device, u64 val) __must_hold(local)
3507 {
3508         unsigned long flags;
3509         if (device->ldev->md.uuid[UI_BITMAP] == 0 && val == 0)
3510                 return;
3511 
3512         spin_lock_irqsave(&device->ldev->md.uuid_lock, flags);
3513         if (val == 0) {
3514                 drbd_uuid_move_history(device);
3515                 device->ldev->md.uuid[UI_HISTORY_START] = device->ldev->md.uuid[UI_BITMAP];
3516                 device->ldev->md.uuid[UI_BITMAP] = 0;
3517         } else {
3518                 unsigned long long bm_uuid = device->ldev->md.uuid[UI_BITMAP];
3519                 if (bm_uuid)
3520                         drbd_warn(device, "bm UUID was already set: %llX\n", bm_uuid);
3521 
3522                 device->ldev->md.uuid[UI_BITMAP] = val & ~((u64)1);
3523         }
3524         spin_unlock_irqrestore(&device->ldev->md.uuid_lock, flags);
3525 
3526         drbd_md_mark_dirty(device);
3527 }
3528 
3529 /**
3530  * drbd_bmio_set_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
3531  * @device:     DRBD device.
3532  *
3533  * Sets all bits in the bitmap and writes the whole bitmap to stable storage.
3534  */
3535 int drbd_bmio_set_n_write(struct drbd_device *device) __must_hold(local)
3536 {
3537         int rv = -EIO;
3538 
3539         drbd_md_set_flag(device, MDF_FULL_SYNC);
3540         drbd_md_sync(device);
3541         drbd_bm_set_all(device);
3542 
3543         rv = drbd_bm_write(device);
3544 
3545         if (!rv) {
3546                 drbd_md_clear_flag(device, MDF_FULL_SYNC);
3547                 drbd_md_sync(device);
3548         }
3549 
3550         return rv;
3551 }
3552 
3553 /**
3554  * drbd_bmio_clear_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
3555  * @device:     DRBD device.
3556  *
3557  * Clears all bits in the bitmap and writes the whole bitmap to stable storage.
3558  */
3559 int drbd_bmio_clear_n_write(struct drbd_device *device) __must_hold(local)
3560 {
3561         drbd_resume_al(device);
3562         drbd_bm_clear_all(device);
3563         return drbd_bm_write(device);
3564 }
3565 
3566 static int w_bitmap_io(struct drbd_work *w, int unused)
3567 {
3568         struct drbd_device *device =
3569                 container_of(w, struct drbd_device, bm_io_work.w);
3570         struct bm_io_work *work = &device->bm_io_work;
3571         int rv = -EIO;
3572 
3573         if (work->flags != BM_LOCKED_CHANGE_ALLOWED) {
3574                 int cnt = atomic_read(&device->ap_bio_cnt);
3575                 if (cnt)
3576                         drbd_err(device, "FIXME: ap_bio_cnt %d, expected 0; queued for '%s'\n",
3577                                         cnt, work->why);
3578         }
3579 
3580         if (get_ldev(device)) {
3581                 drbd_bm_lock(device, work->why, work->flags);
3582                 rv = work->io_fn(device);
3583                 drbd_bm_unlock(device);
3584                 put_ldev(device);
3585         }
3586 
3587         clear_bit_unlock(BITMAP_IO, &device->flags);
3588         wake_up(&device->misc_wait);
3589 
3590         if (work->done)
3591                 work->done(device, rv);
3592 
3593         clear_bit(BITMAP_IO_QUEUED, &device->flags);
3594         work->why = NULL;
3595         work->flags = 0;
3596 
3597         return 0;
3598 }
3599 
3600 /**
3601  * drbd_queue_bitmap_io() - Queues an IO operation on the whole bitmap
3602  * @device:     DRBD device.
3603  * @io_fn:      IO callback to be called when bitmap IO is possible
3604  * @done:       callback to be called after the bitmap IO was performed
3605  * @why:        Descriptive text of the reason for doing the IO
3606  *
3607  * While IO on the bitmap happens we freeze application IO thus we ensure
3608  * that drbd_set_out_of_sync() can not be called. This function MAY ONLY be
3609  * called from worker context. It MUST NOT be used while a previous such
3610  * work is still pending!
3611  *
3612  * Its worker function encloses the call of io_fn() by get_ldev() and
3613  * put_ldev().
3614  */
3615 void drbd_queue_bitmap_io(struct drbd_device *device,
3616                           int (*io_fn)(struct drbd_device *),
3617                           void (*done)(struct drbd_device *, int),
3618                           char *why, enum bm_flag flags)
3619 {
3620         D_ASSERT(device, current == first_peer_device(device)->connection->worker.task);
3621 
3622         D_ASSERT(device, !test_bit(BITMAP_IO_QUEUED, &device->flags));
3623         D_ASSERT(device, !test_bit(BITMAP_IO, &device->flags));
3624         D_ASSERT(device, list_empty(&device->bm_io_work.w.list));
3625         if (device->bm_io_work.why)
3626                 drbd_err(device, "FIXME going to queue '%s' but '%s' still pending?\n",
3627                         why, device->bm_io_work.why);
3628 
3629         device->bm_io_work.io_fn = io_fn;
3630         device->bm_io_work.done = done;
3631         device->bm_io_work.why = why;
3632         device->bm_io_work.flags = flags;
3633 
3634         spin_lock_irq(&device->resource->req_lock);
3635         set_bit(BITMAP_IO, &device->flags);
3636         /* don't wait for pending application IO if the caller indicates that
3637          * application IO does not conflict anyways. */
3638         if (flags == BM_LOCKED_CHANGE_ALLOWED || atomic_read(&device->ap_bio_cnt) == 0) {
3639                 if (!test_and_set_bit(BITMAP_IO_QUEUED, &device->flags))
3640                         drbd_queue_work(&first_peer_device(device)->connection->sender_work,
3641                                         &device->bm_io_work.w);
3642         }
3643         spin_unlock_irq(&device->resource->req_lock);
3644 }
3645 
3646 /**
3647  * drbd_bitmap_io() -  Does an IO operation on the whole bitmap
3648  * @device:     DRBD device.
3649  * @io_fn:      IO callback to be called when bitmap IO is possible
3650  * @why:        Descriptive text of the reason for doing the IO
3651  *
3652  * freezes application IO while that the actual IO operations runs. This
3653  * functions MAY NOT be called from worker context.
3654  */
3655 int drbd_bitmap_io(struct drbd_device *device, int (*io_fn)(struct drbd_device *),
3656                 char *why, enum bm_flag flags)
3657 {
3658         /* Only suspend io, if some operation is supposed to be locked out */
3659         const bool do_suspend_io = flags & (BM_DONT_CLEAR|BM_DONT_SET|BM_DONT_TEST);
3660         int rv;
3661 
3662         D_ASSERT(device, current != first_peer_device(device)->connection->worker.task);
3663 
3664         if (do_suspend_io)
3665                 drbd_suspend_io(device);
3666 
3667         drbd_bm_lock(device, why, flags);
3668         rv = io_fn(device);
3669         drbd_bm_unlock(device);
3670 
3671         if (do_suspend_io)
3672                 drbd_resume_io(device);
3673 
3674         return rv;
3675 }
3676 
3677 void drbd_md_set_flag(struct drbd_device *device, int flag) __must_hold(local)
3678 {
3679         if ((device->ldev->md.flags & flag) != flag) {
3680                 drbd_md_mark_dirty(device);
3681                 device->ldev->md.flags |= flag;
3682         }
3683 }
3684 
3685 void drbd_md_clear_flag(struct drbd_device *device, int flag) __must_hold(local)
3686 {
3687         if ((device->ldev->md.flags & flag) != 0) {
3688                 drbd_md_mark_dirty(device);
3689                 device->ldev->md.flags &= ~flag;
3690         }
3691 }
3692 int drbd_md_test_flag(struct drbd_backing_dev *bdev, int flag)
3693 {
3694         return (bdev->md.flags & flag) != 0;
3695 }
3696 
3697 static void md_sync_timer_fn(struct timer_list *t)
3698 {
3699         struct drbd_device *device = from_timer(device, t, md_sync_timer);
3700         drbd_device_post_work(device, MD_SYNC);
3701 }
3702 
3703 const char *cmdname(enum drbd_packet cmd)
3704 {
3705         /* THINK may need to become several global tables
3706          * when we want to support more than
3707          * one PRO_VERSION */
3708         static const char *cmdnames[] = {
3709                 [P_DATA]                = "Data",
3710                 [P_WSAME]               = "WriteSame",
3711                 [P_TRIM]                = "Trim",
3712                 [P_DATA_REPLY]          = "DataReply",
3713                 [P_RS_DATA_REPLY]       = "RSDataReply",
3714                 [P_BARRIER]             = "Barrier",
3715                 [P_BITMAP]              = "ReportBitMap",
3716                 [P_BECOME_SYNC_TARGET]  = "BecomeSyncTarget",
3717                 [P_BECOME_SYNC_SOURCE]  = "BecomeSyncSource",
3718                 [P_UNPLUG_REMOTE]       = "UnplugRemote",
3719                 [P_DATA_REQUEST]        = "DataRequest",
3720                 [P_RS_DATA_REQUEST]     = "RSDataRequest",
3721                 [P_SYNC_PARAM]          = "SyncParam",
3722                 [P_SYNC_PARAM89]        = "SyncParam89",
3723                 [P_PROTOCOL]            = "ReportProtocol",
3724                 [P_UUIDS]               = "ReportUUIDs",
3725                 [P_SIZES]               = "ReportSizes",
3726                 [P_STATE]               = "ReportState",
3727                 [P_SYNC_UUID]           = "ReportSyncUUID",
3728                 [P_AUTH_CHALLENGE]      = "AuthChallenge",
3729                 [P_AUTH_RESPONSE]       = "AuthResponse",
3730                 [P_PING]                = "Ping",
3731                 [P_PING_ACK]            = "PingAck",
3732                 [P_RECV_ACK]            = "RecvAck",
3733                 [P_WRITE_ACK]           = "WriteAck",
3734                 [P_RS_WRITE_ACK]        = "RSWriteAck",
3735                 [P_SUPERSEDED]          = "Superseded",
3736                 [P_NEG_ACK]             = "NegAck",
3737                 [P_NEG_DREPLY]          = "NegDReply",
3738                 [P_NEG_RS_DREPLY]       = "NegRSDReply",
3739                 [P_BARRIER_ACK]         = "BarrierAck",
3740                 [P_STATE_CHG_REQ]       = "StateChgRequest",
3741                 [P_STATE_CHG_REPLY]     = "StateChgReply",
3742                 [P_OV_REQUEST]          = "OVRequest",
3743                 [P_OV_REPLY]            = "OVReply",
3744                 [P_OV_RESULT]           = "OVResult",
3745                 [P_CSUM_RS_REQUEST]     = "CsumRSRequest",
3746                 [P_RS_IS_IN_SYNC]       = "CsumRSIsInSync",
3747                 [P_COMPRESSED_BITMAP]   = "CBitmap",
3748                 [P_DELAY_PROBE]         = "DelayProbe",
3749                 [P_OUT_OF_SYNC]         = "OutOfSync",
3750                 [P_RETRY_WRITE]         = "RetryWrite",
3751                 [P_RS_CANCEL]           = "RSCancel",
3752                 [P_CONN_ST_CHG_REQ]     = "conn_st_chg_req",
3753                 [P_CONN_ST_CHG_REPLY]   = "conn_st_chg_reply",
3754                 [P_RETRY_WRITE]         = "retry_write",
3755                 [P_PROTOCOL_UPDATE]     = "protocol_update",
3756                 [P_RS_THIN_REQ]         = "rs_thin_req",
3757                 [P_RS_DEALLOCATED]      = "rs_deallocated",
3758 
3759                 /* enum drbd_packet, but not commands - obsoleted flags:
3760                  *      P_MAY_IGNORE
3761                  *      P_MAX_OPT_CMD
3762                  */
3763         };
3764 
3765         /* too big for the array: 0xfffX */
3766         if (cmd == P_INITIAL_META)
3767                 return "InitialMeta";
3768         if (cmd == P_INITIAL_DATA)
3769                 return "InitialData";
3770         if (cmd == P_CONNECTION_FEATURES)
3771                 return "ConnectionFeatures";
3772         if (cmd >= ARRAY_SIZE(cmdnames))
3773                 return "Unknown";
3774         return cmdnames[cmd];
3775 }
3776 
3777 /**
3778  * drbd_wait_misc  -  wait for a request to make progress
3779  * @device:     device associated with the request
3780  * @i:          the struct drbd_interval embedded in struct drbd_request or
3781  *              struct drbd_peer_request
3782  */
3783 int drbd_wait_misc(struct drbd_device *device, struct drbd_interval *i)
3784 {
3785         struct net_conf *nc;
3786         DEFINE_WAIT(wait);
3787         long timeout;
3788 
3789         rcu_read_lock();
3790         nc = rcu_dereference(first_peer_device(device)->connection->net_conf);
3791         if (!nc) {
3792                 rcu_read_unlock();
3793                 return -ETIMEDOUT;
3794         }
3795         timeout = nc->ko_count ? nc->timeout * HZ / 10 * nc->ko_count : MAX_SCHEDULE_TIMEOUT;
3796         rcu_read_unlock();
3797 
3798         /* Indicate to wake up device->misc_wait on progress.  */
3799         i->waiting = true;
3800         prepare_to_wait(&device->misc_wait, &wait, TASK_INTERRUPTIBLE);
3801         spin_unlock_irq(&device->resource->req_lock);
3802         timeout = schedule_timeout(timeout);
3803         finish_wait(&device->misc_wait, &wait);
3804         spin_lock_irq(&device->resource->req_lock);
3805         if (!timeout || device->state.conn < C_CONNECTED)
3806                 return -ETIMEDOUT;
3807         if (signal_pending(current))
3808                 return -ERESTARTSYS;
3809         return 0;
3810 }
3811 
3812 void lock_all_resources(void)
3813 {
3814         struct drbd_resource *resource;
3815         int __maybe_unused i = 0;
3816 
3817         mutex_lock(&resources_mutex);
3818         local_irq_disable();
3819         for_each_resource(resource, &drbd_resources)
3820                 spin_lock_nested(&resource->req_lock, i++);
3821 }
3822 
3823 void unlock_all_resources(void)
3824 {
3825         struct drbd_resource *resource;
3826 
3827         for_each_resource(resource, &drbd_resources)
3828                 spin_unlock(&resource->req_lock);
3829         local_irq_enable();
3830         mutex_unlock(&resources_mutex);
3831 }
3832 
3833 #ifdef CONFIG_DRBD_FAULT_INJECTION
3834 /* Fault insertion support including random number generator shamelessly
3835  * stolen from kernel/rcutorture.c */
3836 struct fault_random_state {
3837         unsigned long state;
3838         unsigned long count;
3839 };
3840 
3841 #define FAULT_RANDOM_MULT 39916801  /* prime */
3842 #define FAULT_RANDOM_ADD        479001701 /* prime */
3843 #define FAULT_RANDOM_REFRESH 10000
3844 
3845 /*
3846  * Crude but fast random-number generator.  Uses a linear congruential
3847  * generator, with occasional help from get_random_bytes().
3848  */
3849 static unsigned long
3850 _drbd_fault_random(struct fault_random_state *rsp)
3851 {
3852         long refresh;
3853 
3854         if (!rsp->count--) {
3855                 get_random_bytes(&refresh, sizeof(refresh));
3856                 rsp->state += refresh;
3857                 rsp->count = FAULT_RANDOM_REFRESH;
3858         }
3859         rsp->state = rsp->state * FAULT_RANDOM_MULT + FAULT_RANDOM_ADD;
3860         return swahw32(rsp->state);
3861 }
3862 
3863 static char *
3864 _drbd_fault_str(unsigned int type) {
3865         static char *_faults[] = {
3866                 [DRBD_FAULT_MD_WR] = "Meta-data write",
3867                 [DRBD_FAULT_MD_RD] = "Meta-data read",
3868                 [DRBD_FAULT_RS_WR] = "Resync write",
3869                 [DRBD_FAULT_RS_RD] = "Resync read",
3870                 [DRBD_FAULT_DT_WR] = "Data write",
3871                 [DRBD_FAULT_DT_RD] = "Data read",
3872                 [DRBD_FAULT_DT_RA] = "Data read ahead",
3873                 [DRBD_FAULT_BM_ALLOC] = "BM allocation",
3874                 [DRBD_FAULT_AL_EE] = "EE allocation",
3875                 [DRBD_FAULT_RECEIVE] = "receive data corruption",
3876         };
3877 
3878         return (type < DRBD_FAULT_MAX) ? _faults[type] : "**Unknown**";
3879 }
3880 
3881 unsigned int
3882 _drbd_insert_fault(struct drbd_device *device, unsigned int type)
3883 {
3884         static struct fault_random_state rrs = {0, 0};
3885 
3886         unsigned int ret = (
3887                 (drbd_fault_devs == 0 ||
3888                         ((1 << device_to_minor(device)) & drbd_fault_devs) != 0) &&
3889                 (((_drbd_fault_random(&rrs) % 100) + 1) <= drbd_fault_rate));
3890 
3891         if (ret) {
3892                 drbd_fault_count++;
3893 
3894                 if (__ratelimit(&drbd_ratelimit_state))
3895                         drbd_warn(device, "***Simulating %s failure\n",
3896                                 _drbd_fault_str(type));
3897         }
3898 
3899         return ret;
3900 }
3901 #endif
3902 
3903 const char *drbd_buildtag(void)
3904 {
3905         /* DRBD built from external sources has here a reference to the
3906            git hash of the source code. */
3907 
3908         static char buildtag[38] = "\0uilt-in";
3909 
3910         if (buildtag[0] == 0) {
3911 #ifdef MODULE
3912                 sprintf(buildtag, "srcversion: %-24s", THIS_MODULE->srcversion);
3913 #else
3914                 buildtag[0] = 'b';
3915 #endif
3916         }
3917 
3918         return buildtag;
3919 }
3920 
3921 module_init(drbd_init)
3922 module_exit(drbd_cleanup)
3923 
3924 EXPORT_SYMBOL(drbd_conn_str);
3925 EXPORT_SYMBOL(drbd_role_str);
3926 EXPORT_SYMBOL(drbd_disk_str);
3927 EXPORT_SYMBOL(drbd_set_st_err_str);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/block/drbd/drbd_main.c

DEFINITIONS
