1/* 2 drbd_int.h 3 4 This file is part of DRBD by Philipp Reisner and Lars Ellenberg. 5 6 Copyright (C) 2001-2008, LINBIT Information Technologies GmbH. 7 Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>. 8 Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>. 9 10 drbd is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License as published by 12 the Free Software Foundation; either version 2, or (at your option) 13 any later version. 14 15 drbd is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 GNU General Public License for more details. 19 20 You should have received a copy of the GNU General Public License 21 along with drbd; see the file COPYING. If not, write to 22 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 23 24*/ 25 26#ifndef _DRBD_INT_H 27#define _DRBD_INT_H 28 29#include <linux/compiler.h> 30#include <linux/types.h> 31#include <linux/list.h> 32#include <linux/sched.h> 33#include <linux/bitops.h> 34#include <linux/slab.h> 35#include <linux/crypto.h> 36#include <linux/ratelimit.h> 37#include <linux/tcp.h> 38#include <linux/mutex.h> 39#include <linux/major.h> 40#include <linux/blkdev.h> 41#include <linux/genhd.h> 42#include <linux/idr.h> 43#include <net/tcp.h> 44#include <linux/lru_cache.h> 45#include <linux/prefetch.h> 46#include <linux/drbd_genl_api.h> 47#include <linux/drbd.h> 48#include "drbd_strings.h" 49#include "drbd_state.h" 50#include "drbd_protocol.h" 51 52#ifdef __CHECKER__ 53# define __protected_by(x) __attribute__((require_context(x,1,999,"rdwr"))) 54# define __protected_read_by(x) __attribute__((require_context(x,1,999,"read"))) 55# define __protected_write_by(x) __attribute__((require_context(x,1,999,"write"))) 56# define __must_hold(x) __attribute__((context(x,1,1), require_context(x,1,999,"call"))) 57#else 58# define __protected_by(x) 59# define __protected_read_by(x) 60# define __protected_write_by(x) 61# define __must_hold(x) 62#endif 63 64/* module parameter, defined in drbd_main.c */ 65extern unsigned int minor_count; 66extern bool disable_sendpage; 67extern bool allow_oos; 68void tl_abort_disk_io(struct drbd_device *device); 69 70#ifdef CONFIG_DRBD_FAULT_INJECTION 71extern int enable_faults; 72extern int fault_rate; 73extern int fault_devs; 74#endif 75 76extern char usermode_helper[]; 77 78 79/* I don't remember why XCPU ... 80 * This is used to wake the asender, 81 * and to interrupt sending the sending task 82 * on disconnect. 83 */ 84#define DRBD_SIG SIGXCPU 85 86/* This is used to stop/restart our threads. 87 * Cannot use SIGTERM nor SIGKILL, since these 88 * are sent out by init on runlevel changes 89 * I choose SIGHUP for now. 90 */ 91#define DRBD_SIGKILL SIGHUP 92 93#define ID_IN_SYNC (4711ULL) 94#define ID_OUT_OF_SYNC (4712ULL) 95#define ID_SYNCER (-1ULL) 96 97#define UUID_NEW_BM_OFFSET ((u64)0x0001000000000000ULL) 98 99struct drbd_device; 100struct drbd_connection; 101 102#define __drbd_printk_device(level, device, fmt, args...) \ 103 dev_printk(level, disk_to_dev((device)->vdisk), fmt, ## args) 104#define __drbd_printk_peer_device(level, peer_device, fmt, args...) \ 105 dev_printk(level, disk_to_dev((peer_device)->device->vdisk), fmt, ## args) 106#define __drbd_printk_resource(level, resource, fmt, args...) \ 107 printk(level "drbd %s: " fmt, (resource)->name, ## args) 108#define __drbd_printk_connection(level, connection, fmt, args...) \ 109 printk(level "drbd %s: " fmt, (connection)->resource->name, ## args) 110 111void drbd_printk_with_wrong_object_type(void); 112 113#define __drbd_printk_if_same_type(obj, type, func, level, fmt, args...) \ 114 (__builtin_types_compatible_p(typeof(obj), type) || \ 115 __builtin_types_compatible_p(typeof(obj), const type)), \ 116 func(level, (const type)(obj), fmt, ## args) 117 118#define drbd_printk(level, obj, fmt, args...) \ 119 __builtin_choose_expr( \ 120 __drbd_printk_if_same_type(obj, struct drbd_device *, \ 121 __drbd_printk_device, level, fmt, ## args), \ 122 __builtin_choose_expr( \ 123 __drbd_printk_if_same_type(obj, struct drbd_resource *, \ 124 __drbd_printk_resource, level, fmt, ## args), \ 125 __builtin_choose_expr( \ 126 __drbd_printk_if_same_type(obj, struct drbd_connection *, \ 127 __drbd_printk_connection, level, fmt, ## args), \ 128 __builtin_choose_expr( \ 129 __drbd_printk_if_same_type(obj, struct drbd_peer_device *, \ 130 __drbd_printk_peer_device, level, fmt, ## args), \ 131 drbd_printk_with_wrong_object_type())))) 132 133#define drbd_dbg(obj, fmt, args...) \ 134 drbd_printk(KERN_DEBUG, obj, fmt, ## args) 135#define drbd_alert(obj, fmt, args...) \ 136 drbd_printk(KERN_ALERT, obj, fmt, ## args) 137#define drbd_err(obj, fmt, args...) \ 138 drbd_printk(KERN_ERR, obj, fmt, ## args) 139#define drbd_warn(obj, fmt, args...) \ 140 drbd_printk(KERN_WARNING, obj, fmt, ## args) 141#define drbd_info(obj, fmt, args...) \ 142 drbd_printk(KERN_INFO, obj, fmt, ## args) 143#define drbd_emerg(obj, fmt, args...) \ 144 drbd_printk(KERN_EMERG, obj, fmt, ## args) 145 146#define dynamic_drbd_dbg(device, fmt, args...) \ 147 dynamic_dev_dbg(disk_to_dev(device->vdisk), fmt, ## args) 148 149#define D_ASSERT(device, exp) do { \ 150 if (!(exp)) \ 151 drbd_err(device, "ASSERT( " #exp " ) in %s:%d\n", __FILE__, __LINE__); \ 152 } while (0) 153 154/** 155 * expect - Make an assertion 156 * 157 * Unlike the assert macro, this macro returns a boolean result. 158 */ 159#define expect(exp) ({ \ 160 bool _bool = (exp); \ 161 if (!_bool) \ 162 drbd_err(device, "ASSERTION %s FAILED in %s\n", \ 163 #exp, __func__); \ 164 _bool; \ 165 }) 166 167/* Defines to control fault insertion */ 168enum { 169 DRBD_FAULT_MD_WR = 0, /* meta data write */ 170 DRBD_FAULT_MD_RD = 1, /* read */ 171 DRBD_FAULT_RS_WR = 2, /* resync */ 172 DRBD_FAULT_RS_RD = 3, 173 DRBD_FAULT_DT_WR = 4, /* data */ 174 DRBD_FAULT_DT_RD = 5, 175 DRBD_FAULT_DT_RA = 6, /* data read ahead */ 176 DRBD_FAULT_BM_ALLOC = 7, /* bitmap allocation */ 177 DRBD_FAULT_AL_EE = 8, /* alloc ee */ 178 DRBD_FAULT_RECEIVE = 9, /* Changes some bytes upon receiving a [rs]data block */ 179 180 DRBD_FAULT_MAX, 181}; 182 183extern unsigned int 184_drbd_insert_fault(struct drbd_device *device, unsigned int type); 185 186static inline int 187drbd_insert_fault(struct drbd_device *device, unsigned int type) { 188#ifdef CONFIG_DRBD_FAULT_INJECTION 189 return fault_rate && 190 (enable_faults & (1<<type)) && 191 _drbd_insert_fault(device, type); 192#else 193 return 0; 194#endif 195} 196 197/* integer division, round _UP_ to the next integer */ 198#define div_ceil(A, B) ((A)/(B) + ((A)%(B) ? 1 : 0)) 199/* usual integer division */ 200#define div_floor(A, B) ((A)/(B)) 201 202extern struct ratelimit_state drbd_ratelimit_state; 203extern struct idr drbd_devices; /* RCU, updates: genl_lock() */ 204extern struct list_head drbd_resources; /* RCU, updates: genl_lock() */ 205 206extern const char *cmdname(enum drbd_packet cmd); 207 208/* for sending/receiving the bitmap, 209 * possibly in some encoding scheme */ 210struct bm_xfer_ctx { 211 /* "const" 212 * stores total bits and long words 213 * of the bitmap, so we don't need to 214 * call the accessor functions over and again. */ 215 unsigned long bm_bits; 216 unsigned long bm_words; 217 /* during xfer, current position within the bitmap */ 218 unsigned long bit_offset; 219 unsigned long word_offset; 220 221 /* statistics; index: (h->command == P_BITMAP) */ 222 unsigned packets[2]; 223 unsigned bytes[2]; 224}; 225 226extern void INFO_bm_xfer_stats(struct drbd_device *device, 227 const char *direction, struct bm_xfer_ctx *c); 228 229static inline void bm_xfer_ctx_bit_to_word_offset(struct bm_xfer_ctx *c) 230{ 231 /* word_offset counts "native long words" (32 or 64 bit), 232 * aligned at 64 bit. 233 * Encoded packet may end at an unaligned bit offset. 234 * In case a fallback clear text packet is transmitted in 235 * between, we adjust this offset back to the last 64bit 236 * aligned "native long word", which makes coding and decoding 237 * the plain text bitmap much more convenient. */ 238#if BITS_PER_LONG == 64 239 c->word_offset = c->bit_offset >> 6; 240#elif BITS_PER_LONG == 32 241 c->word_offset = c->bit_offset >> 5; 242 c->word_offset &= ~(1UL); 243#else 244# error "unsupported BITS_PER_LONG" 245#endif 246} 247 248extern unsigned int drbd_header_size(struct drbd_connection *connection); 249 250/**********************************************************************/ 251enum drbd_thread_state { 252 NONE, 253 RUNNING, 254 EXITING, 255 RESTARTING 256}; 257 258struct drbd_thread { 259 spinlock_t t_lock; 260 struct task_struct *task; 261 struct completion stop; 262 enum drbd_thread_state t_state; 263 int (*function) (struct drbd_thread *); 264 struct drbd_resource *resource; 265 struct drbd_connection *connection; 266 int reset_cpu_mask; 267 const char *name; 268}; 269 270static inline enum drbd_thread_state get_t_state(struct drbd_thread *thi) 271{ 272 /* THINK testing the t_state seems to be uncritical in all cases 273 * (but thread_{start,stop}), so we can read it *without* the lock. 274 * --lge */ 275 276 smp_rmb(); 277 return thi->t_state; 278} 279 280struct drbd_work { 281 struct list_head list; 282 int (*cb)(struct drbd_work *, int cancel); 283}; 284 285struct drbd_device_work { 286 struct drbd_work w; 287 struct drbd_device *device; 288}; 289 290#include "drbd_interval.h" 291 292extern int drbd_wait_misc(struct drbd_device *, struct drbd_interval *); 293 294struct drbd_request { 295 struct drbd_work w; 296 struct drbd_device *device; 297 298 /* if local IO is not allowed, will be NULL. 299 * if local IO _is_ allowed, holds the locally submitted bio clone, 300 * or, after local IO completion, the ERR_PTR(error). 301 * see drbd_request_endio(). */ 302 struct bio *private_bio; 303 304 struct drbd_interval i; 305 306 /* epoch: used to check on "completion" whether this req was in 307 * the current epoch, and we therefore have to close it, 308 * causing a p_barrier packet to be send, starting a new epoch. 309 * 310 * This corresponds to "barrier" in struct p_barrier[_ack], 311 * and to "barrier_nr" in struct drbd_epoch (and various 312 * comments/function parameters/local variable names). 313 */ 314 unsigned int epoch; 315 316 struct list_head tl_requests; /* ring list in the transfer log */ 317 struct bio *master_bio; /* master bio pointer */ 318 319 /* see struct drbd_device */ 320 struct list_head req_pending_master_completion; 321 struct list_head req_pending_local; 322 323 /* for generic IO accounting */ 324 unsigned long start_jif; 325 326 /* for DRBD internal statistics */ 327 328 /* Minimal set of time stamps to determine if we wait for activity log 329 * transactions, local disk or peer. 32 bit "jiffies" are good enough, 330 * we don't expect a DRBD request to be stalled for several month. 331 */ 332 333 /* before actual request processing */ 334 unsigned long in_actlog_jif; 335 336 /* local disk */ 337 unsigned long pre_submit_jif; 338 339 /* per connection */ 340 unsigned long pre_send_jif; 341 unsigned long acked_jif; 342 unsigned long net_done_jif; 343 344 /* Possibly even more detail to track each phase: 345 * master_completion_jif 346 * how long did it take to complete the master bio 347 * (application visible latency) 348 * allocated_jif 349 * how long the master bio was blocked until we finally allocated 350 * a tracking struct 351 * in_actlog_jif 352 * how long did we wait for activity log transactions 353 * 354 * net_queued_jif 355 * when did we finally queue it for sending 356 * pre_send_jif 357 * when did we start sending it 358 * post_send_jif 359 * how long did we block in the network stack trying to send it 360 * acked_jif 361 * when did we receive (or fake, in protocol A) a remote ACK 362 * net_done_jif 363 * when did we receive final acknowledgement (P_BARRIER_ACK), 364 * or decide, e.g. on connection loss, that we do no longer expect 365 * anything from this peer for this request. 366 * 367 * pre_submit_jif 368 * post_sub_jif 369 * when did we start submiting to the lower level device, 370 * and how long did we block in that submit function 371 * local_completion_jif 372 * how long did it take the lower level device to complete this request 373 */ 374 375 376 /* once it hits 0, we may complete the master_bio */ 377 atomic_t completion_ref; 378 /* once it hits 0, we may destroy this drbd_request object */ 379 struct kref kref; 380 381 unsigned rq_state; /* see comments above _req_mod() */ 382}; 383 384struct drbd_epoch { 385 struct drbd_connection *connection; 386 struct list_head list; 387 unsigned int barrier_nr; 388 atomic_t epoch_size; /* increased on every request added. */ 389 atomic_t active; /* increased on every req. added, and dec on every finished. */ 390 unsigned long flags; 391}; 392 393/* Prototype declaration of function defined in drbd_receiver.c */ 394int drbdd_init(struct drbd_thread *); 395int drbd_asender(struct drbd_thread *); 396 397/* drbd_epoch flag bits */ 398enum { 399 DE_HAVE_BARRIER_NUMBER, 400}; 401 402enum epoch_event { 403 EV_PUT, 404 EV_GOT_BARRIER_NR, 405 EV_BECAME_LAST, 406 EV_CLEANUP = 32, /* used as flag */ 407}; 408 409struct digest_info { 410 int digest_size; 411 void *digest; 412}; 413 414struct drbd_peer_request { 415 struct drbd_work w; 416 struct drbd_peer_device *peer_device; 417 struct drbd_epoch *epoch; /* for writes */ 418 struct page *pages; 419 atomic_t pending_bios; 420 struct drbd_interval i; 421 /* see comments on ee flag bits below */ 422 unsigned long flags; 423 unsigned long submit_jif; 424 union { 425 u64 block_id; 426 struct digest_info *digest; 427 }; 428}; 429 430/* ee flag bits. 431 * While corresponding bios are in flight, the only modification will be 432 * set_bit WAS_ERROR, which has to be atomic. 433 * If no bios are in flight yet, or all have been completed, 434 * non-atomic modification to ee->flags is ok. 435 */ 436enum { 437 __EE_CALL_AL_COMPLETE_IO, 438 __EE_MAY_SET_IN_SYNC, 439 440 /* is this a TRIM aka REQ_DISCARD? */ 441 __EE_IS_TRIM, 442 /* our lower level cannot handle trim, 443 * and we want to fall back to zeroout instead */ 444 __EE_IS_TRIM_USE_ZEROOUT, 445 446 /* In case a barrier failed, 447 * we need to resubmit without the barrier flag. */ 448 __EE_RESUBMITTED, 449 450 /* we may have several bios per peer request. 451 * if any of those fail, we set this flag atomically 452 * from the endio callback */ 453 __EE_WAS_ERROR, 454 455 /* This ee has a pointer to a digest instead of a block id */ 456 __EE_HAS_DIGEST, 457 458 /* Conflicting local requests need to be restarted after this request */ 459 __EE_RESTART_REQUESTS, 460 461 /* The peer wants a write ACK for this (wire proto C) */ 462 __EE_SEND_WRITE_ACK, 463 464 /* Is set when net_conf had two_primaries set while creating this peer_req */ 465 __EE_IN_INTERVAL_TREE, 466 467 /* for debugfs: */ 468 /* has this been submitted, or does it still wait for something else? */ 469 __EE_SUBMITTED, 470 471 /* this is/was a write request */ 472 __EE_WRITE, 473 474 /* this originates from application on peer 475 * (not some resync or verify or other DRBD internal request) */ 476 __EE_APPLICATION, 477}; 478#define EE_CALL_AL_COMPLETE_IO (1<<__EE_CALL_AL_COMPLETE_IO) 479#define EE_MAY_SET_IN_SYNC (1<<__EE_MAY_SET_IN_SYNC) 480#define EE_IS_TRIM (1<<__EE_IS_TRIM) 481#define EE_IS_TRIM_USE_ZEROOUT (1<<__EE_IS_TRIM_USE_ZEROOUT) 482#define EE_RESUBMITTED (1<<__EE_RESUBMITTED) 483#define EE_WAS_ERROR (1<<__EE_WAS_ERROR) 484#define EE_HAS_DIGEST (1<<__EE_HAS_DIGEST) 485#define EE_RESTART_REQUESTS (1<<__EE_RESTART_REQUESTS) 486#define EE_SEND_WRITE_ACK (1<<__EE_SEND_WRITE_ACK) 487#define EE_IN_INTERVAL_TREE (1<<__EE_IN_INTERVAL_TREE) 488#define EE_SUBMITTED (1<<__EE_SUBMITTED) 489#define EE_WRITE (1<<__EE_WRITE) 490#define EE_APPLICATION (1<<__EE_APPLICATION) 491 492/* flag bits per device */ 493enum { 494 UNPLUG_REMOTE, /* sending a "UnplugRemote" could help */ 495 MD_DIRTY, /* current uuids and flags not yet on disk */ 496 USE_DEGR_WFC_T, /* degr-wfc-timeout instead of wfc-timeout. */ 497 CL_ST_CHG_SUCCESS, 498 CL_ST_CHG_FAIL, 499 CRASHED_PRIMARY, /* This node was a crashed primary. 500 * Gets cleared when the state.conn 501 * goes into C_CONNECTED state. */ 502 CONSIDER_RESYNC, 503 504 MD_NO_FUA, /* Users wants us to not use FUA/FLUSH on meta data dev */ 505 506 SUSPEND_IO, /* suspend application io */ 507 BITMAP_IO, /* suspend application io; 508 once no more io in flight, start bitmap io */ 509 BITMAP_IO_QUEUED, /* Started bitmap IO */ 510 WAS_IO_ERROR, /* Local disk failed, returned IO error */ 511 WAS_READ_ERROR, /* Local disk READ failed (set additionally to the above) */ 512 FORCE_DETACH, /* Force-detach from local disk, aborting any pending local IO */ 513 RESYNC_AFTER_NEG, /* Resync after online grow after the attach&negotiate finished. */ 514 RESIZE_PENDING, /* Size change detected locally, waiting for the response from 515 * the peer, if it changed there as well. */ 516 NEW_CUR_UUID, /* Create new current UUID when thawing IO */ 517 AL_SUSPENDED, /* Activity logging is currently suspended. */ 518 AHEAD_TO_SYNC_SOURCE, /* Ahead -> SyncSource queued */ 519 B_RS_H_DONE, /* Before resync handler done (already executed) */ 520 DISCARD_MY_DATA, /* discard_my_data flag per volume */ 521 READ_BALANCE_RR, 522 523 FLUSH_PENDING, /* if set, device->flush_jif is when we submitted that flush 524 * from drbd_flush_after_epoch() */ 525 526 /* cleared only after backing device related structures have been destroyed. */ 527 GOING_DISKLESS, /* Disk is being detached, because of io-error, or admin request. */ 528 529 /* to be used in drbd_device_post_work() */ 530 GO_DISKLESS, /* tell worker to schedule cleanup before detach */ 531 DESTROY_DISK, /* tell worker to close backing devices and destroy related structures. */ 532 MD_SYNC, /* tell worker to call drbd_md_sync() */ 533 RS_START, /* tell worker to start resync/OV */ 534 RS_PROGRESS, /* tell worker that resync made significant progress */ 535 RS_DONE, /* tell worker that resync is done */ 536}; 537 538struct drbd_bitmap; /* opaque for drbd_device */ 539 540/* definition of bits in bm_flags to be used in drbd_bm_lock 541 * and drbd_bitmap_io and friends. */ 542enum bm_flag { 543 /* do we need to kfree, or vfree bm_pages? */ 544 BM_P_VMALLOCED = 0x10000, /* internal use only, will be masked out */ 545 546 /* currently locked for bulk operation */ 547 BM_LOCKED_MASK = 0xf, 548 549 /* in detail, that is: */ 550 BM_DONT_CLEAR = 0x1, 551 BM_DONT_SET = 0x2, 552 BM_DONT_TEST = 0x4, 553 554 /* so we can mark it locked for bulk operation, 555 * and still allow all non-bulk operations */ 556 BM_IS_LOCKED = 0x8, 557 558 /* (test bit, count bit) allowed (common case) */ 559 BM_LOCKED_TEST_ALLOWED = BM_DONT_CLEAR | BM_DONT_SET | BM_IS_LOCKED, 560 561 /* testing bits, as well as setting new bits allowed, but clearing bits 562 * would be unexpected. Used during bitmap receive. Setting new bits 563 * requires sending of "out-of-sync" information, though. */ 564 BM_LOCKED_SET_ALLOWED = BM_DONT_CLEAR | BM_IS_LOCKED, 565 566 /* for drbd_bm_write_copy_pages, everything is allowed, 567 * only concurrent bulk operations are locked out. */ 568 BM_LOCKED_CHANGE_ALLOWED = BM_IS_LOCKED, 569}; 570 571struct drbd_work_queue { 572 struct list_head q; 573 spinlock_t q_lock; /* to protect the list. */ 574 wait_queue_head_t q_wait; 575}; 576 577struct drbd_socket { 578 struct mutex mutex; 579 struct socket *socket; 580 /* this way we get our 581 * send/receive buffers off the stack */ 582 void *sbuf; 583 void *rbuf; 584}; 585 586struct drbd_md { 587 u64 md_offset; /* sector offset to 'super' block */ 588 589 u64 la_size_sect; /* last agreed size, unit sectors */ 590 spinlock_t uuid_lock; 591 u64 uuid[UI_SIZE]; 592 u64 device_uuid; 593 u32 flags; 594 u32 md_size_sect; 595 596 s32 al_offset; /* signed relative sector offset to activity log */ 597 s32 bm_offset; /* signed relative sector offset to bitmap */ 598 599 /* cached value of bdev->disk_conf->meta_dev_idx (see below) */ 600 s32 meta_dev_idx; 601 602 /* see al_tr_number_to_on_disk_sector() */ 603 u32 al_stripes; 604 u32 al_stripe_size_4k; 605 u32 al_size_4k; /* cached product of the above */ 606}; 607 608struct drbd_backing_dev { 609 struct block_device *backing_bdev; 610 struct block_device *md_bdev; 611 struct drbd_md md; 612 struct disk_conf *disk_conf; /* RCU, for updates: resource->conf_update */ 613 sector_t known_size; /* last known size of that backing device */ 614}; 615 616struct drbd_md_io { 617 struct page *page; 618 unsigned long start_jif; /* last call to drbd_md_get_buffer */ 619 unsigned long submit_jif; /* last _drbd_md_sync_page_io() submit */ 620 const char *current_use; 621 atomic_t in_use; 622 unsigned int done; 623 int error; 624}; 625 626struct bm_io_work { 627 struct drbd_work w; 628 char *why; 629 enum bm_flag flags; 630 int (*io_fn)(struct drbd_device *device); 631 void (*done)(struct drbd_device *device, int rv); 632}; 633 634enum write_ordering_e { 635 WO_none, 636 WO_drain_io, 637 WO_bdev_flush, 638}; 639 640struct fifo_buffer { 641 unsigned int head_index; 642 unsigned int size; 643 int total; /* sum of all values */ 644 int values[0]; 645}; 646extern struct fifo_buffer *fifo_alloc(int fifo_size); 647 648/* flag bits per connection */ 649enum { 650 NET_CONGESTED, /* The data socket is congested */ 651 RESOLVE_CONFLICTS, /* Set on one node, cleared on the peer! */ 652 SEND_PING, /* whether asender should send a ping asap */ 653 SIGNAL_ASENDER, /* whether asender wants to be interrupted */ 654 GOT_PING_ACK, /* set when we receive a ping_ack packet, ping_wait gets woken */ 655 CONN_WD_ST_CHG_REQ, /* A cluster wide state change on the connection is active */ 656 CONN_WD_ST_CHG_OKAY, 657 CONN_WD_ST_CHG_FAIL, 658 CONN_DRY_RUN, /* Expect disconnect after resync handshake. */ 659 CREATE_BARRIER, /* next P_DATA is preceded by a P_BARRIER */ 660 STATE_SENT, /* Do not change state/UUIDs while this is set */ 661 CALLBACK_PENDING, /* Whether we have a call_usermodehelper(, UMH_WAIT_PROC) 662 * pending, from drbd worker context. 663 * If set, bdi_write_congested() returns true, 664 * so shrink_page_list() would not recurse into, 665 * and potentially deadlock on, this drbd worker. 666 */ 667 DISCONNECT_SENT, 668 669 DEVICE_WORK_PENDING, /* tell worker that some device has pending work */ 670}; 671 672struct drbd_resource { 673 char *name; 674#ifdef CONFIG_DEBUG_FS 675 struct dentry *debugfs_res; 676 struct dentry *debugfs_res_volumes; 677 struct dentry *debugfs_res_connections; 678 struct dentry *debugfs_res_in_flight_summary; 679#endif 680 struct kref kref; 681 struct idr devices; /* volume number to device mapping */ 682 struct list_head connections; 683 struct list_head resources; 684 struct res_opts res_opts; 685 struct mutex conf_update; /* mutex for ready-copy-update of net_conf and disk_conf */ 686 struct mutex adm_mutex; /* mutex to serialize administrative requests */ 687 spinlock_t req_lock; 688 689 unsigned susp:1; /* IO suspended by user */ 690 unsigned susp_nod:1; /* IO suspended because no data */ 691 unsigned susp_fen:1; /* IO suspended because fence peer handler runs */ 692 693 enum write_ordering_e write_ordering; 694 695 cpumask_var_t cpu_mask; 696}; 697 698struct drbd_thread_timing_details 699{ 700 unsigned long start_jif; 701 void *cb_addr; 702 const char *caller_fn; 703 unsigned int line; 704 unsigned int cb_nr; 705}; 706 707struct drbd_connection { 708 struct list_head connections; 709 struct drbd_resource *resource; 710#ifdef CONFIG_DEBUG_FS 711 struct dentry *debugfs_conn; 712 struct dentry *debugfs_conn_callback_history; 713 struct dentry *debugfs_conn_oldest_requests; 714#endif 715 struct kref kref; 716 struct idr peer_devices; /* volume number to peer device mapping */ 717 enum drbd_conns cstate; /* Only C_STANDALONE to C_WF_REPORT_PARAMS */ 718 struct mutex cstate_mutex; /* Protects graceful disconnects */ 719 unsigned int connect_cnt; /* Inc each time a connection is established */ 720 721 unsigned long flags; 722 struct net_conf *net_conf; /* content protected by rcu */ 723 wait_queue_head_t ping_wait; /* Woken upon reception of a ping, and a state change */ 724 725 struct sockaddr_storage my_addr; 726 int my_addr_len; 727 struct sockaddr_storage peer_addr; 728 int peer_addr_len; 729 730 struct drbd_socket data; /* data/barrier/cstate/parameter packets */ 731 struct drbd_socket meta; /* ping/ack (metadata) packets */ 732 int agreed_pro_version; /* actually used protocol version */ 733 u32 agreed_features; 734 unsigned long last_received; /* in jiffies, either socket */ 735 unsigned int ko_count; 736 737 struct list_head transfer_log; /* all requests not yet fully processed */ 738 739 struct crypto_hash *cram_hmac_tfm; 740 struct crypto_hash *integrity_tfm; /* checksums we compute, updates protected by connection->data->mutex */ 741 struct crypto_hash *peer_integrity_tfm; /* checksums we verify, only accessed from receiver thread */ 742 struct crypto_hash *csums_tfm; 743 struct crypto_hash *verify_tfm; 744 void *int_dig_in; 745 void *int_dig_vv; 746 747 /* receiver side */ 748 struct drbd_epoch *current_epoch; 749 spinlock_t epoch_lock; 750 unsigned int epochs; 751 atomic_t current_tle_nr; /* transfer log epoch number */ 752 unsigned current_tle_writes; /* writes seen within this tl epoch */ 753 754 unsigned long last_reconnect_jif; 755 struct drbd_thread receiver; 756 struct drbd_thread worker; 757 struct drbd_thread asender; 758 759 /* cached pointers, 760 * so we can look up the oldest pending requests more quickly. 761 * protected by resource->req_lock */ 762 struct drbd_request *req_next; /* DRBD 9: todo.req_next */ 763 struct drbd_request *req_ack_pending; 764 struct drbd_request *req_not_net_done; 765 766 /* sender side */ 767 struct drbd_work_queue sender_work; 768 769#define DRBD_THREAD_DETAILS_HIST 16 770 unsigned int w_cb_nr; /* keeps counting up */ 771 unsigned int r_cb_nr; /* keeps counting up */ 772 struct drbd_thread_timing_details w_timing_details[DRBD_THREAD_DETAILS_HIST]; 773 struct drbd_thread_timing_details r_timing_details[DRBD_THREAD_DETAILS_HIST]; 774 775 struct { 776 /* whether this sender thread 777 * has processed a single write yet. */ 778 bool seen_any_write_yet; 779 780 /* Which barrier number to send with the next P_BARRIER */ 781 int current_epoch_nr; 782 783 /* how many write requests have been sent 784 * with req->epoch == current_epoch_nr. 785 * If none, no P_BARRIER will be sent. */ 786 unsigned current_epoch_writes; 787 } send; 788}; 789 790void __update_timing_details( 791 struct drbd_thread_timing_details *tdp, 792 unsigned int *cb_nr, 793 void *cb, 794 const char *fn, const unsigned int line); 795 796#define update_worker_timing_details(c, cb) \ 797 __update_timing_details(c->w_timing_details, &c->w_cb_nr, cb, __func__ , __LINE__ ) 798#define update_receiver_timing_details(c, cb) \ 799 __update_timing_details(c->r_timing_details, &c->r_cb_nr, cb, __func__ , __LINE__ ) 800 801struct submit_worker { 802 struct workqueue_struct *wq; 803 struct work_struct worker; 804 805 /* protected by ..->resource->req_lock */ 806 struct list_head writes; 807}; 808 809struct drbd_peer_device { 810 struct list_head peer_devices; 811 struct drbd_device *device; 812 struct drbd_connection *connection; 813#ifdef CONFIG_DEBUG_FS 814 struct dentry *debugfs_peer_dev; 815#endif 816}; 817 818struct drbd_device { 819 struct drbd_resource *resource; 820 struct list_head peer_devices; 821 struct list_head pending_bitmap_io; 822 823 unsigned long flush_jif; 824#ifdef CONFIG_DEBUG_FS 825 struct dentry *debugfs_minor; 826 struct dentry *debugfs_vol; 827 struct dentry *debugfs_vol_oldest_requests; 828 struct dentry *debugfs_vol_act_log_extents; 829 struct dentry *debugfs_vol_resync_extents; 830 struct dentry *debugfs_vol_data_gen_id; 831#endif 832 833 unsigned int vnr; /* volume number within the connection */ 834 unsigned int minor; /* device minor number */ 835 836 struct kref kref; 837 838 /* things that are stored as / read from meta data on disk */ 839 unsigned long flags; 840 841 /* configured by drbdsetup */ 842 struct drbd_backing_dev *ldev __protected_by(local); 843 844 sector_t p_size; /* partner's disk size */ 845 struct request_queue *rq_queue; 846 struct block_device *this_bdev; 847 struct gendisk *vdisk; 848 849 unsigned long last_reattach_jif; 850 struct drbd_work resync_work; 851 struct drbd_work unplug_work; 852 struct timer_list resync_timer; 853 struct timer_list md_sync_timer; 854 struct timer_list start_resync_timer; 855 struct timer_list request_timer; 856 857 /* Used after attach while negotiating new disk state. */ 858 union drbd_state new_state_tmp; 859 860 union drbd_dev_state state; 861 wait_queue_head_t misc_wait; 862 wait_queue_head_t state_wait; /* upon each state change. */ 863 unsigned int send_cnt; 864 unsigned int recv_cnt; 865 unsigned int read_cnt; 866 unsigned int writ_cnt; 867 unsigned int al_writ_cnt; 868 unsigned int bm_writ_cnt; 869 atomic_t ap_bio_cnt; /* Requests we need to complete */ 870 atomic_t ap_actlog_cnt; /* Requests waiting for activity log */ 871 atomic_t ap_pending_cnt; /* AP data packets on the wire, ack expected */ 872 atomic_t rs_pending_cnt; /* RS request/data packets on the wire */ 873 atomic_t unacked_cnt; /* Need to send replies for */ 874 atomic_t local_cnt; /* Waiting for local completion */ 875 876 /* Interval tree of pending local requests */ 877 struct rb_root read_requests; 878 struct rb_root write_requests; 879 880 /* for statistics and timeouts */ 881 /* [0] read, [1] write */ 882 struct list_head pending_master_completion[2]; 883 struct list_head pending_completion[2]; 884 885 /* use checksums for *this* resync */ 886 bool use_csums; 887 /* blocks to resync in this run [unit BM_BLOCK_SIZE] */ 888 unsigned long rs_total; 889 /* number of resync blocks that failed in this run */ 890 unsigned long rs_failed; 891 /* Syncer's start time [unit jiffies] */ 892 unsigned long rs_start; 893 /* cumulated time in PausedSyncX state [unit jiffies] */ 894 unsigned long rs_paused; 895 /* skipped because csum was equal [unit BM_BLOCK_SIZE] */ 896 unsigned long rs_same_csum; 897#define DRBD_SYNC_MARKS 8 898#define DRBD_SYNC_MARK_STEP (3*HZ) 899 /* block not up-to-date at mark [unit BM_BLOCK_SIZE] */ 900 unsigned long rs_mark_left[DRBD_SYNC_MARKS]; 901 /* marks's time [unit jiffies] */ 902 unsigned long rs_mark_time[DRBD_SYNC_MARKS]; 903 /* current index into rs_mark_{left,time} */ 904 int rs_last_mark; 905 unsigned long rs_last_bcast; /* [unit jiffies] */ 906 907 /* where does the admin want us to start? (sector) */ 908 sector_t ov_start_sector; 909 sector_t ov_stop_sector; 910 /* where are we now? (sector) */ 911 sector_t ov_position; 912 /* Start sector of out of sync range (to merge printk reporting). */ 913 sector_t ov_last_oos_start; 914 /* size of out-of-sync range in sectors. */ 915 sector_t ov_last_oos_size; 916 unsigned long ov_left; /* in bits */ 917 918 struct drbd_bitmap *bitmap; 919 unsigned long bm_resync_fo; /* bit offset for drbd_bm_find_next */ 920 921 /* Used to track operations of resync... */ 922 struct lru_cache *resync; 923 /* Number of locked elements in resync LRU */ 924 unsigned int resync_locked; 925 /* resync extent number waiting for application requests */ 926 unsigned int resync_wenr; 927 928 int open_cnt; 929 u64 *p_uuid; 930 931 struct list_head active_ee; /* IO in progress (P_DATA gets written to disk) */ 932 struct list_head sync_ee; /* IO in progress (P_RS_DATA_REPLY gets written to disk) */ 933 struct list_head done_ee; /* need to send P_WRITE_ACK */ 934 struct list_head read_ee; /* [RS]P_DATA_REQUEST being read */ 935 struct list_head net_ee; /* zero-copy network send in progress */ 936 937 int next_barrier_nr; 938 struct list_head resync_reads; 939 atomic_t pp_in_use; /* allocated from page pool */ 940 atomic_t pp_in_use_by_net; /* sendpage()d, still referenced by tcp */ 941 wait_queue_head_t ee_wait; 942 struct drbd_md_io md_io; 943 spinlock_t al_lock; 944 wait_queue_head_t al_wait; 945 struct lru_cache *act_log; /* activity log */ 946 unsigned int al_tr_number; 947 int al_tr_cycle; 948 wait_queue_head_t seq_wait; 949 atomic_t packet_seq; 950 unsigned int peer_seq; 951 spinlock_t peer_seq_lock; 952 unsigned long comm_bm_set; /* communicated number of set bits. */ 953 struct bm_io_work bm_io_work; 954 u64 ed_uuid; /* UUID of the exposed data */ 955 struct mutex own_state_mutex; 956 struct mutex *state_mutex; /* either own_state_mutex or first_peer_device(device)->connection->cstate_mutex */ 957 char congestion_reason; /* Why we where congested... */ 958 atomic_t rs_sect_in; /* for incoming resync data rate, SyncTarget */ 959 atomic_t rs_sect_ev; /* for submitted resync data rate, both */ 960 int rs_last_sect_ev; /* counter to compare with */ 961 int rs_last_events; /* counter of read or write "events" (unit sectors) 962 * on the lower level device when we last looked. */ 963 int c_sync_rate; /* current resync rate after syncer throttle magic */ 964 struct fifo_buffer *rs_plan_s; /* correction values of resync planer (RCU, connection->conn_update) */ 965 int rs_in_flight; /* resync sectors in flight (to proxy, in proxy and from proxy) */ 966 atomic_t ap_in_flight; /* App sectors in flight (waiting for ack) */ 967 unsigned int peer_max_bio_size; 968 unsigned int local_max_bio_size; 969 970 /* any requests that would block in drbd_make_request() 971 * are deferred to this single-threaded work queue */ 972 struct submit_worker submit; 973}; 974 975struct drbd_bm_aio_ctx { 976 struct drbd_device *device; 977 struct list_head list; /* on device->pending_bitmap_io */; 978 unsigned long start_jif; 979 atomic_t in_flight; 980 unsigned int done; 981 unsigned flags; 982#define BM_AIO_COPY_PAGES 1 983#define BM_AIO_WRITE_HINTED 2 984#define BM_AIO_WRITE_ALL_PAGES 4 985#define BM_AIO_READ 8 986 int error; 987 struct kref kref; 988}; 989 990struct drbd_config_context { 991 /* assigned from drbd_genlmsghdr */ 992 unsigned int minor; 993 /* assigned from request attributes, if present */ 994 unsigned int volume; 995#define VOLUME_UNSPECIFIED (-1U) 996 /* pointer into the request skb, 997 * limited lifetime! */ 998 char *resource_name; 999 struct nlattr *my_addr; 1000 struct nlattr *peer_addr; 1001 1002 /* reply buffer */ 1003 struct sk_buff *reply_skb; 1004 /* pointer into reply buffer */ 1005 struct drbd_genlmsghdr *reply_dh; 1006 /* resolved from attributes, if possible */ 1007 struct drbd_device *device; 1008 struct drbd_resource *resource; 1009 struct drbd_connection *connection; 1010}; 1011 1012static inline struct drbd_device *minor_to_device(unsigned int minor) 1013{ 1014 return (struct drbd_device *)idr_find(&drbd_devices, minor); 1015} 1016 1017static inline struct drbd_peer_device *first_peer_device(struct drbd_device *device) 1018{ 1019 return list_first_entry_or_null(&device->peer_devices, struct drbd_peer_device, peer_devices); 1020} 1021 1022#define for_each_resource(resource, _resources) \ 1023 list_for_each_entry(resource, _resources, resources) 1024 1025#define for_each_resource_rcu(resource, _resources) \ 1026 list_for_each_entry_rcu(resource, _resources, resources) 1027 1028#define for_each_resource_safe(resource, tmp, _resources) \ 1029 list_for_each_entry_safe(resource, tmp, _resources, resources) 1030 1031#define for_each_connection(connection, resource) \ 1032 list_for_each_entry(connection, &resource->connections, connections) 1033 1034#define for_each_connection_rcu(connection, resource) \ 1035 list_for_each_entry_rcu(connection, &resource->connections, connections) 1036 1037#define for_each_connection_safe(connection, tmp, resource) \ 1038 list_for_each_entry_safe(connection, tmp, &resource->connections, connections) 1039 1040#define for_each_peer_device(peer_device, device) \ 1041 list_for_each_entry(peer_device, &device->peer_devices, peer_devices) 1042 1043#define for_each_peer_device_rcu(peer_device, device) \ 1044 list_for_each_entry_rcu(peer_device, &device->peer_devices, peer_devices) 1045 1046#define for_each_peer_device_safe(peer_device, tmp, device) \ 1047 list_for_each_entry_safe(peer_device, tmp, &device->peer_devices, peer_devices) 1048 1049static inline unsigned int device_to_minor(struct drbd_device *device) 1050{ 1051 return device->minor; 1052} 1053 1054/* 1055 * function declarations 1056 *************************/ 1057 1058/* drbd_main.c */ 1059 1060enum dds_flags { 1061 DDSF_FORCED = 1, 1062 DDSF_NO_RESYNC = 2, /* Do not run a resync for the new space */ 1063}; 1064 1065extern void drbd_init_set_defaults(struct drbd_device *device); 1066extern int drbd_thread_start(struct drbd_thread *thi); 1067extern void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait); 1068#ifdef CONFIG_SMP 1069extern void drbd_thread_current_set_cpu(struct drbd_thread *thi); 1070#else 1071#define drbd_thread_current_set_cpu(A) ({}) 1072#endif 1073extern void tl_release(struct drbd_connection *, unsigned int barrier_nr, 1074 unsigned int set_size); 1075extern void tl_clear(struct drbd_connection *); 1076extern void drbd_free_sock(struct drbd_connection *connection); 1077extern int drbd_send(struct drbd_connection *connection, struct socket *sock, 1078 void *buf, size_t size, unsigned msg_flags); 1079extern int drbd_send_all(struct drbd_connection *, struct socket *, void *, size_t, 1080 unsigned); 1081 1082extern int __drbd_send_protocol(struct drbd_connection *connection, enum drbd_packet cmd); 1083extern int drbd_send_protocol(struct drbd_connection *connection); 1084extern int drbd_send_uuids(struct drbd_peer_device *); 1085extern int drbd_send_uuids_skip_initial_sync(struct drbd_peer_device *); 1086extern void drbd_gen_and_send_sync_uuid(struct drbd_peer_device *); 1087extern int drbd_send_sizes(struct drbd_peer_device *, int trigger_reply, enum dds_flags flags); 1088extern int drbd_send_state(struct drbd_peer_device *, union drbd_state s); 1089extern int drbd_send_current_state(struct drbd_peer_device *); 1090extern int drbd_send_sync_param(struct drbd_peer_device *); 1091extern void drbd_send_b_ack(struct drbd_connection *connection, u32 barrier_nr, 1092 u32 set_size); 1093extern int drbd_send_ack(struct drbd_peer_device *, enum drbd_packet, 1094 struct drbd_peer_request *); 1095extern void drbd_send_ack_rp(struct drbd_peer_device *, enum drbd_packet, 1096 struct p_block_req *rp); 1097extern void drbd_send_ack_dp(struct drbd_peer_device *, enum drbd_packet, 1098 struct p_data *dp, int data_size); 1099extern int drbd_send_ack_ex(struct drbd_peer_device *, enum drbd_packet, 1100 sector_t sector, int blksize, u64 block_id); 1101extern int drbd_send_out_of_sync(struct drbd_peer_device *, struct drbd_request *); 1102extern int drbd_send_block(struct drbd_peer_device *, enum drbd_packet, 1103 struct drbd_peer_request *); 1104extern int drbd_send_dblock(struct drbd_peer_device *, struct drbd_request *req); 1105extern int drbd_send_drequest(struct drbd_peer_device *, int cmd, 1106 sector_t sector, int size, u64 block_id); 1107extern int drbd_send_drequest_csum(struct drbd_peer_device *, sector_t sector, 1108 int size, void *digest, int digest_size, 1109 enum drbd_packet cmd); 1110extern int drbd_send_ov_request(struct drbd_peer_device *, sector_t sector, int size); 1111 1112extern int drbd_send_bitmap(struct drbd_device *device); 1113extern void drbd_send_sr_reply(struct drbd_peer_device *, enum drbd_state_rv retcode); 1114extern void conn_send_sr_reply(struct drbd_connection *connection, enum drbd_state_rv retcode); 1115extern void drbd_free_ldev(struct drbd_backing_dev *ldev); 1116extern void drbd_device_cleanup(struct drbd_device *device); 1117void drbd_print_uuids(struct drbd_device *device, const char *text); 1118 1119extern void conn_md_sync(struct drbd_connection *connection); 1120extern void drbd_md_write(struct drbd_device *device, void *buffer); 1121extern void drbd_md_sync(struct drbd_device *device); 1122extern int drbd_md_read(struct drbd_device *device, struct drbd_backing_dev *bdev); 1123extern void drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local); 1124extern void _drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local); 1125extern void drbd_uuid_new_current(struct drbd_device *device) __must_hold(local); 1126extern void drbd_uuid_set_bm(struct drbd_device *device, u64 val) __must_hold(local); 1127extern void drbd_uuid_move_history(struct drbd_device *device) __must_hold(local); 1128extern void __drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local); 1129extern void drbd_md_set_flag(struct drbd_device *device, int flags) __must_hold(local); 1130extern void drbd_md_clear_flag(struct drbd_device *device, int flags)__must_hold(local); 1131extern int drbd_md_test_flag(struct drbd_backing_dev *, int); 1132extern void drbd_md_mark_dirty(struct drbd_device *device); 1133extern void drbd_queue_bitmap_io(struct drbd_device *device, 1134 int (*io_fn)(struct drbd_device *), 1135 void (*done)(struct drbd_device *, int), 1136 char *why, enum bm_flag flags); 1137extern int drbd_bitmap_io(struct drbd_device *device, 1138 int (*io_fn)(struct drbd_device *), 1139 char *why, enum bm_flag flags); 1140extern int drbd_bitmap_io_from_worker(struct drbd_device *device, 1141 int (*io_fn)(struct drbd_device *), 1142 char *why, enum bm_flag flags); 1143extern int drbd_bmio_set_n_write(struct drbd_device *device) __must_hold(local); 1144extern int drbd_bmio_clear_n_write(struct drbd_device *device) __must_hold(local); 1145 1146/* Meta data layout 1147 * 1148 * We currently have two possible layouts. 1149 * Offsets in (512 byte) sectors. 1150 * external: 1151 * |----------- md_size_sect ------------------| 1152 * [ 4k superblock ][ activity log ][ Bitmap ] 1153 * | al_offset == 8 | 1154 * | bm_offset = al_offset + X | 1155 * ==> bitmap sectors = md_size_sect - bm_offset 1156 * 1157 * Variants: 1158 * old, indexed fixed size meta data: 1159 * 1160 * internal: 1161 * |----------- md_size_sect ------------------| 1162 * [data.....][ Bitmap ][ activity log ][ 4k superblock ][padding*] 1163 * | al_offset < 0 | 1164 * | bm_offset = al_offset - Y | 1165 * ==> bitmap sectors = Y = al_offset - bm_offset 1166 * 1167 * [padding*] are zero or up to 7 unused 512 Byte sectors to the 1168 * end of the device, so that the [4k superblock] will be 4k aligned. 1169 * 1170 * The activity log consists of 4k transaction blocks, 1171 * which are written in a ring-buffer, or striped ring-buffer like fashion, 1172 * which are writtensize used to be fixed 32kB, 1173 * but is about to become configurable. 1174 */ 1175 1176/* Our old fixed size meta data layout 1177 * allows up to about 3.8TB, so if you want more, 1178 * you need to use the "flexible" meta data format. */ 1179#define MD_128MB_SECT (128LLU << 11) /* 128 MB, unit sectors */ 1180#define MD_4kB_SECT 8 1181#define MD_32kB_SECT 64 1182 1183/* One activity log extent represents 4M of storage */ 1184#define AL_EXTENT_SHIFT 22 1185#define AL_EXTENT_SIZE (1<<AL_EXTENT_SHIFT) 1186 1187/* We could make these currently hardcoded constants configurable 1188 * variables at create-md time (or even re-configurable at runtime?). 1189 * Which will require some more changes to the DRBD "super block" 1190 * and attach code. 1191 * 1192 * updates per transaction: 1193 * This many changes to the active set can be logged with one transaction. 1194 * This number is arbitrary. 1195 * context per transaction: 1196 * This many context extent numbers are logged with each transaction. 1197 * This number is resulting from the transaction block size (4k), the layout 1198 * of the transaction header, and the number of updates per transaction. 1199 * See drbd_actlog.c:struct al_transaction_on_disk 1200 * */ 1201#define AL_UPDATES_PER_TRANSACTION 64 // arbitrary 1202#define AL_CONTEXT_PER_TRANSACTION 919 // (4096 - 36 - 6*64)/4 1203 1204#if BITS_PER_LONG == 32 1205#define LN2_BPL 5 1206#define cpu_to_lel(A) cpu_to_le32(A) 1207#define lel_to_cpu(A) le32_to_cpu(A) 1208#elif BITS_PER_LONG == 64 1209#define LN2_BPL 6 1210#define cpu_to_lel(A) cpu_to_le64(A) 1211#define lel_to_cpu(A) le64_to_cpu(A) 1212#else 1213#error "LN2 of BITS_PER_LONG unknown!" 1214#endif 1215 1216/* resync bitmap */ 1217/* 16MB sized 'bitmap extent' to track syncer usage */ 1218struct bm_extent { 1219 int rs_left; /* number of bits set (out of sync) in this extent. */ 1220 int rs_failed; /* number of failed resync requests in this extent. */ 1221 unsigned long flags; 1222 struct lc_element lce; 1223}; 1224 1225#define BME_NO_WRITES 0 /* bm_extent.flags: no more requests on this one! */ 1226#define BME_LOCKED 1 /* bm_extent.flags: syncer active on this one. */ 1227#define BME_PRIORITY 2 /* finish resync IO on this extent ASAP! App IO waiting! */ 1228 1229/* drbd_bitmap.c */ 1230/* 1231 * We need to store one bit for a block. 1232 * Example: 1GB disk @ 4096 byte blocks ==> we need 32 KB bitmap. 1233 * Bit 0 ==> local node thinks this block is binary identical on both nodes 1234 * Bit 1 ==> local node thinks this block needs to be synced. 1235 */ 1236 1237#define SLEEP_TIME (HZ/10) 1238 1239/* We do bitmap IO in units of 4k blocks. 1240 * We also still have a hardcoded 4k per bit relation. */ 1241#define BM_BLOCK_SHIFT 12 /* 4k per bit */ 1242#define BM_BLOCK_SIZE (1<<BM_BLOCK_SHIFT) 1243/* mostly arbitrarily set the represented size of one bitmap extent, 1244 * aka resync extent, to 16 MiB (which is also 512 Byte worth of bitmap 1245 * at 4k per bit resolution) */ 1246#define BM_EXT_SHIFT 24 /* 16 MiB per resync extent */ 1247#define BM_EXT_SIZE (1<<BM_EXT_SHIFT) 1248 1249#if (BM_EXT_SHIFT != 24) || (BM_BLOCK_SHIFT != 12) 1250#error "HAVE YOU FIXED drbdmeta AS WELL??" 1251#endif 1252 1253/* thus many _storage_ sectors are described by one bit */ 1254#define BM_SECT_TO_BIT(x) ((x)>>(BM_BLOCK_SHIFT-9)) 1255#define BM_BIT_TO_SECT(x) ((sector_t)(x)<<(BM_BLOCK_SHIFT-9)) 1256#define BM_SECT_PER_BIT BM_BIT_TO_SECT(1) 1257 1258/* bit to represented kilo byte conversion */ 1259#define Bit2KB(bits) ((bits)<<(BM_BLOCK_SHIFT-10)) 1260 1261/* in which _bitmap_ extent (resp. sector) the bit for a certain 1262 * _storage_ sector is located in */ 1263#define BM_SECT_TO_EXT(x) ((x)>>(BM_EXT_SHIFT-9)) 1264#define BM_BIT_TO_EXT(x) ((x) >> (BM_EXT_SHIFT - BM_BLOCK_SHIFT)) 1265 1266/* first storage sector a bitmap extent corresponds to */ 1267#define BM_EXT_TO_SECT(x) ((sector_t)(x) << (BM_EXT_SHIFT-9)) 1268/* how much _storage_ sectors we have per bitmap extent */ 1269#define BM_SECT_PER_EXT BM_EXT_TO_SECT(1) 1270/* how many bits are covered by one bitmap extent (resync extent) */ 1271#define BM_BITS_PER_EXT (1UL << (BM_EXT_SHIFT - BM_BLOCK_SHIFT)) 1272 1273#define BM_BLOCKS_PER_BM_EXT_MASK (BM_BITS_PER_EXT - 1) 1274 1275 1276/* in one sector of the bitmap, we have this many activity_log extents. */ 1277#define AL_EXT_PER_BM_SECT (1 << (BM_EXT_SHIFT - AL_EXTENT_SHIFT)) 1278 1279/* the extent in "PER_EXTENT" below is an activity log extent 1280 * we need that many (long words/bytes) to store the bitmap 1281 * of one AL_EXTENT_SIZE chunk of storage. 1282 * we can store the bitmap for that many AL_EXTENTS within 1283 * one sector of the _on_disk_ bitmap: 1284 * bit 0 bit 37 bit 38 bit (512*8)-1 1285 * ...|........|........|.. // ..|........| 1286 * sect. 0 `296 `304 ^(512*8*8)-1 1287 * 1288#define BM_WORDS_PER_EXT ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / BITS_PER_LONG ) 1289#define BM_BYTES_PER_EXT ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / 8 ) // 128 1290#define BM_EXT_PER_SECT ( 512 / BM_BYTES_PER_EXTENT ) // 4 1291 */ 1292 1293#define DRBD_MAX_SECTORS_32 (0xffffffffLU) 1294/* we have a certain meta data variant that has a fixed on-disk size of 128 1295 * MiB, of which 4k are our "superblock", and 32k are the fixed size activity 1296 * log, leaving this many sectors for the bitmap. 1297 */ 1298 1299#define DRBD_MAX_SECTORS_FIXED_BM \ 1300 ((MD_128MB_SECT - MD_32kB_SECT - MD_4kB_SECT) * (1LL<<(BM_EXT_SHIFT-9))) 1301#if !defined(CONFIG_LBDAF) && BITS_PER_LONG == 32 1302#define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_32 1303#define DRBD_MAX_SECTORS_FLEX DRBD_MAX_SECTORS_32 1304#else 1305#define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_FIXED_BM 1306/* 16 TB in units of sectors */ 1307#if BITS_PER_LONG == 32 1308/* adjust by one page worth of bitmap, 1309 * so we won't wrap around in drbd_bm_find_next_bit. 1310 * you should use 64bit OS for that much storage, anyways. */ 1311#define DRBD_MAX_SECTORS_FLEX BM_BIT_TO_SECT(0xffff7fff) 1312#else 1313/* we allow up to 1 PiB now on 64bit architecture with "flexible" meta data */ 1314#define DRBD_MAX_SECTORS_FLEX (1UL << 51) 1315/* corresponds to (1UL << 38) bits right now. */ 1316#endif 1317#endif 1318 1319/* BIO_MAX_SIZE is 256 * PAGE_CACHE_SIZE, 1320 * so for typical PAGE_CACHE_SIZE of 4k, that is (1<<20) Byte. 1321 * Since we may live in a mixed-platform cluster, 1322 * we limit us to a platform agnostic constant here for now. 1323 * A followup commit may allow even bigger BIO sizes, 1324 * once we thought that through. */ 1325#define DRBD_MAX_BIO_SIZE (1U << 20) 1326#if DRBD_MAX_BIO_SIZE > BIO_MAX_SIZE 1327#error Architecture not supported: DRBD_MAX_BIO_SIZE > BIO_MAX_SIZE 1328#endif 1329#define DRBD_MAX_BIO_SIZE_SAFE (1U << 12) /* Works always = 4k */ 1330 1331#define DRBD_MAX_SIZE_H80_PACKET (1U << 15) /* Header 80 only allows packets up to 32KiB data */ 1332#define DRBD_MAX_BIO_SIZE_P95 (1U << 17) /* Protocol 95 to 99 allows bios up to 128KiB */ 1333 1334/* For now, don't allow more than one activity log extent worth of data 1335 * to be discarded in one go. We may need to rework drbd_al_begin_io() 1336 * to allow for even larger discard ranges */ 1337#define DRBD_MAX_DISCARD_SIZE AL_EXTENT_SIZE 1338#define DRBD_MAX_DISCARD_SECTORS (DRBD_MAX_DISCARD_SIZE >> 9) 1339 1340extern int drbd_bm_init(struct drbd_device *device); 1341extern int drbd_bm_resize(struct drbd_device *device, sector_t sectors, int set_new_bits); 1342extern void drbd_bm_cleanup(struct drbd_device *device); 1343extern void drbd_bm_set_all(struct drbd_device *device); 1344extern void drbd_bm_clear_all(struct drbd_device *device); 1345/* set/clear/test only a few bits at a time */ 1346extern int drbd_bm_set_bits( 1347 struct drbd_device *device, unsigned long s, unsigned long e); 1348extern int drbd_bm_clear_bits( 1349 struct drbd_device *device, unsigned long s, unsigned long e); 1350extern int drbd_bm_count_bits( 1351 struct drbd_device *device, const unsigned long s, const unsigned long e); 1352/* bm_set_bits variant for use while holding drbd_bm_lock, 1353 * may process the whole bitmap in one go */ 1354extern void _drbd_bm_set_bits(struct drbd_device *device, 1355 const unsigned long s, const unsigned long e); 1356extern int drbd_bm_test_bit(struct drbd_device *device, unsigned long bitnr); 1357extern int drbd_bm_e_weight(struct drbd_device *device, unsigned long enr); 1358extern int drbd_bm_read(struct drbd_device *device) __must_hold(local); 1359extern void drbd_bm_mark_for_writeout(struct drbd_device *device, int page_nr); 1360extern int drbd_bm_write(struct drbd_device *device) __must_hold(local); 1361extern int drbd_bm_write_hinted(struct drbd_device *device) __must_hold(local); 1362extern int drbd_bm_write_lazy(struct drbd_device *device, unsigned upper_idx) __must_hold(local); 1363extern int drbd_bm_write_all(struct drbd_device *device) __must_hold(local); 1364extern int drbd_bm_write_copy_pages(struct drbd_device *device) __must_hold(local); 1365extern size_t drbd_bm_words(struct drbd_device *device); 1366extern unsigned long drbd_bm_bits(struct drbd_device *device); 1367extern sector_t drbd_bm_capacity(struct drbd_device *device); 1368 1369#define DRBD_END_OF_BITMAP (~(unsigned long)0) 1370extern unsigned long drbd_bm_find_next(struct drbd_device *device, unsigned long bm_fo); 1371/* bm_find_next variants for use while you hold drbd_bm_lock() */ 1372extern unsigned long _drbd_bm_find_next(struct drbd_device *device, unsigned long bm_fo); 1373extern unsigned long _drbd_bm_find_next_zero(struct drbd_device *device, unsigned long bm_fo); 1374extern unsigned long _drbd_bm_total_weight(struct drbd_device *device); 1375extern unsigned long drbd_bm_total_weight(struct drbd_device *device); 1376/* for receive_bitmap */ 1377extern void drbd_bm_merge_lel(struct drbd_device *device, size_t offset, 1378 size_t number, unsigned long *buffer); 1379/* for _drbd_send_bitmap */ 1380extern void drbd_bm_get_lel(struct drbd_device *device, size_t offset, 1381 size_t number, unsigned long *buffer); 1382 1383extern void drbd_bm_lock(struct drbd_device *device, char *why, enum bm_flag flags); 1384extern void drbd_bm_unlock(struct drbd_device *device); 1385/* drbd_main.c */ 1386 1387extern struct kmem_cache *drbd_request_cache; 1388extern struct kmem_cache *drbd_ee_cache; /* peer requests */ 1389extern struct kmem_cache *drbd_bm_ext_cache; /* bitmap extents */ 1390extern struct kmem_cache *drbd_al_ext_cache; /* activity log extents */ 1391extern mempool_t *drbd_request_mempool; 1392extern mempool_t *drbd_ee_mempool; 1393 1394/* drbd's page pool, used to buffer data received from the peer, 1395 * or data requested by the peer. 1396 * 1397 * This does not have an emergency reserve. 1398 * 1399 * When allocating from this pool, it first takes pages from the pool. 1400 * Only if the pool is depleted will try to allocate from the system. 1401 * 1402 * The assumption is that pages taken from this pool will be processed, 1403 * and given back, "quickly", and then can be recycled, so we can avoid 1404 * frequent calls to alloc_page(), and still will be able to make progress even 1405 * under memory pressure. 1406 */ 1407extern struct page *drbd_pp_pool; 1408extern spinlock_t drbd_pp_lock; 1409extern int drbd_pp_vacant; 1410extern wait_queue_head_t drbd_pp_wait; 1411 1412/* We also need a standard (emergency-reserve backed) page pool 1413 * for meta data IO (activity log, bitmap). 1414 * We can keep it global, as long as it is used as "N pages at a time". 1415 * 128 should be plenty, currently we probably can get away with as few as 1. 1416 */ 1417#define DRBD_MIN_POOL_PAGES 128 1418extern mempool_t *drbd_md_io_page_pool; 1419 1420/* We also need to make sure we get a bio 1421 * when we need it for housekeeping purposes */ 1422extern struct bio_set *drbd_md_io_bio_set; 1423/* to allocate from that set */ 1424extern struct bio *bio_alloc_drbd(gfp_t gfp_mask); 1425 1426extern rwlock_t global_state_lock; 1427 1428extern int conn_lowest_minor(struct drbd_connection *connection); 1429extern enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsigned int minor); 1430extern void drbd_destroy_device(struct kref *kref); 1431extern void drbd_delete_device(struct drbd_device *device); 1432 1433extern struct drbd_resource *drbd_create_resource(const char *name); 1434extern void drbd_free_resource(struct drbd_resource *resource); 1435 1436extern int set_resource_options(struct drbd_resource *resource, struct res_opts *res_opts); 1437extern struct drbd_connection *conn_create(const char *name, struct res_opts *res_opts); 1438extern void drbd_destroy_connection(struct kref *kref); 1439extern struct drbd_connection *conn_get_by_addrs(void *my_addr, int my_addr_len, 1440 void *peer_addr, int peer_addr_len); 1441extern struct drbd_resource *drbd_find_resource(const char *name); 1442extern void drbd_destroy_resource(struct kref *kref); 1443extern void conn_free_crypto(struct drbd_connection *connection); 1444 1445extern int proc_details; 1446 1447/* drbd_req */ 1448extern void do_submit(struct work_struct *ws); 1449extern void __drbd_make_request(struct drbd_device *, struct bio *, unsigned long); 1450extern void drbd_make_request(struct request_queue *q, struct bio *bio); 1451extern int drbd_read_remote(struct drbd_device *device, struct drbd_request *req); 1452extern int drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct bio_vec *bvec); 1453extern int is_valid_ar_handle(struct drbd_request *, sector_t); 1454 1455 1456/* drbd_nl.c */ 1457extern int drbd_msg_put_info(struct sk_buff *skb, const char *info); 1458extern void drbd_suspend_io(struct drbd_device *device); 1459extern void drbd_resume_io(struct drbd_device *device); 1460extern char *ppsize(char *buf, unsigned long long size); 1461extern sector_t drbd_new_dev_size(struct drbd_device *, struct drbd_backing_dev *, sector_t, int); 1462enum determine_dev_size { 1463 DS_ERROR_SHRINK = -3, 1464 DS_ERROR_SPACE_MD = -2, 1465 DS_ERROR = -1, 1466 DS_UNCHANGED = 0, 1467 DS_SHRUNK = 1, 1468 DS_GREW = 2, 1469 DS_GREW_FROM_ZERO = 3, 1470}; 1471extern enum determine_dev_size 1472drbd_determine_dev_size(struct drbd_device *, enum dds_flags, struct resize_parms *) __must_hold(local); 1473extern void resync_after_online_grow(struct drbd_device *); 1474extern void drbd_reconsider_max_bio_size(struct drbd_device *device, struct drbd_backing_dev *bdev); 1475extern enum drbd_state_rv drbd_set_role(struct drbd_device *device, 1476 enum drbd_role new_role, 1477 int force); 1478extern bool conn_try_outdate_peer(struct drbd_connection *connection); 1479extern void conn_try_outdate_peer_async(struct drbd_connection *connection); 1480extern int drbd_khelper(struct drbd_device *device, char *cmd); 1481 1482/* drbd_worker.c */ 1483/* bi_end_io handlers */ 1484extern void drbd_md_endio(struct bio *bio, int error); 1485extern void drbd_peer_request_endio(struct bio *bio, int error); 1486extern void drbd_request_endio(struct bio *bio, int error); 1487extern int drbd_worker(struct drbd_thread *thi); 1488enum drbd_ret_code drbd_resync_after_valid(struct drbd_device *device, int o_minor); 1489void drbd_resync_after_changed(struct drbd_device *device); 1490extern void drbd_start_resync(struct drbd_device *device, enum drbd_conns side); 1491extern void resume_next_sg(struct drbd_device *device); 1492extern void suspend_other_sg(struct drbd_device *device); 1493extern int drbd_resync_finished(struct drbd_device *device); 1494/* maybe rather drbd_main.c ? */ 1495extern void *drbd_md_get_buffer(struct drbd_device *device, const char *intent); 1496extern void drbd_md_put_buffer(struct drbd_device *device); 1497extern int drbd_md_sync_page_io(struct drbd_device *device, 1498 struct drbd_backing_dev *bdev, sector_t sector, int rw); 1499extern void drbd_ov_out_of_sync_found(struct drbd_device *, sector_t, int); 1500extern void wait_until_done_or_force_detached(struct drbd_device *device, 1501 struct drbd_backing_dev *bdev, unsigned int *done); 1502extern void drbd_rs_controller_reset(struct drbd_device *device); 1503 1504static inline void ov_out_of_sync_print(struct drbd_device *device) 1505{ 1506 if (device->ov_last_oos_size) { 1507 drbd_err(device, "Out of sync: start=%llu, size=%lu (sectors)\n", 1508 (unsigned long long)device->ov_last_oos_start, 1509 (unsigned long)device->ov_last_oos_size); 1510 } 1511 device->ov_last_oos_size = 0; 1512} 1513 1514 1515extern void drbd_csum_bio(struct crypto_hash *, struct bio *, void *); 1516extern void drbd_csum_ee(struct crypto_hash *, struct drbd_peer_request *, void *); 1517/* worker callbacks */ 1518extern int w_e_end_data_req(struct drbd_work *, int); 1519extern int w_e_end_rsdata_req(struct drbd_work *, int); 1520extern int w_e_end_csum_rs_req(struct drbd_work *, int); 1521extern int w_e_end_ov_reply(struct drbd_work *, int); 1522extern int w_e_end_ov_req(struct drbd_work *, int); 1523extern int w_ov_finished(struct drbd_work *, int); 1524extern int w_resync_timer(struct drbd_work *, int); 1525extern int w_send_write_hint(struct drbd_work *, int); 1526extern int w_send_dblock(struct drbd_work *, int); 1527extern int w_send_read_req(struct drbd_work *, int); 1528extern int w_e_reissue(struct drbd_work *, int); 1529extern int w_restart_disk_io(struct drbd_work *, int); 1530extern int w_send_out_of_sync(struct drbd_work *, int); 1531extern int w_start_resync(struct drbd_work *, int); 1532 1533extern void resync_timer_fn(unsigned long data); 1534extern void start_resync_timer_fn(unsigned long data); 1535 1536extern void drbd_endio_write_sec_final(struct drbd_peer_request *peer_req); 1537 1538/* drbd_receiver.c */ 1539extern int drbd_receiver(struct drbd_thread *thi); 1540extern int drbd_asender(struct drbd_thread *thi); 1541extern bool drbd_rs_c_min_rate_throttle(struct drbd_device *device); 1542extern bool drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector, 1543 bool throttle_if_app_is_waiting); 1544extern int drbd_submit_peer_request(struct drbd_device *, 1545 struct drbd_peer_request *, const unsigned, 1546 const int); 1547extern int drbd_free_peer_reqs(struct drbd_device *, struct list_head *); 1548extern struct drbd_peer_request *drbd_alloc_peer_req(struct drbd_peer_device *, u64, 1549 sector_t, unsigned int, 1550 bool, 1551 gfp_t) __must_hold(local); 1552extern void __drbd_free_peer_req(struct drbd_device *, struct drbd_peer_request *, 1553 int); 1554#define drbd_free_peer_req(m,e) __drbd_free_peer_req(m, e, 0) 1555#define drbd_free_net_peer_req(m,e) __drbd_free_peer_req(m, e, 1) 1556extern struct page *drbd_alloc_pages(struct drbd_peer_device *, unsigned int, bool); 1557extern void drbd_set_recv_tcq(struct drbd_device *device, int tcq_enabled); 1558extern void _drbd_clear_done_ee(struct drbd_device *device, struct list_head *to_be_freed); 1559extern int drbd_connected(struct drbd_peer_device *); 1560 1561/* Yes, there is kernel_setsockopt, but only since 2.6.18. 1562 * So we have our own copy of it here. */ 1563static inline int drbd_setsockopt(struct socket *sock, int level, int optname, 1564 char *optval, int optlen) 1565{ 1566 mm_segment_t oldfs = get_fs(); 1567 char __user *uoptval; 1568 int err; 1569 1570 uoptval = (char __user __force *)optval; 1571 1572 set_fs(KERNEL_DS); 1573 if (level == SOL_SOCKET) 1574 err = sock_setsockopt(sock, level, optname, uoptval, optlen); 1575 else 1576 err = sock->ops->setsockopt(sock, level, optname, uoptval, 1577 optlen); 1578 set_fs(oldfs); 1579 return err; 1580} 1581 1582static inline void drbd_tcp_cork(struct socket *sock) 1583{ 1584 int val = 1; 1585 (void) drbd_setsockopt(sock, SOL_TCP, TCP_CORK, 1586 (char*)&val, sizeof(val)); 1587} 1588 1589static inline void drbd_tcp_uncork(struct socket *sock) 1590{ 1591 int val = 0; 1592 (void) drbd_setsockopt(sock, SOL_TCP, TCP_CORK, 1593 (char*)&val, sizeof(val)); 1594} 1595 1596static inline void drbd_tcp_nodelay(struct socket *sock) 1597{ 1598 int val = 1; 1599 (void) drbd_setsockopt(sock, SOL_TCP, TCP_NODELAY, 1600 (char*)&val, sizeof(val)); 1601} 1602 1603static inline void drbd_tcp_quickack(struct socket *sock) 1604{ 1605 int val = 2; 1606 (void) drbd_setsockopt(sock, SOL_TCP, TCP_QUICKACK, 1607 (char*)&val, sizeof(val)); 1608} 1609 1610/* sets the number of 512 byte sectors of our virtual device */ 1611static inline void drbd_set_my_capacity(struct drbd_device *device, 1612 sector_t size) 1613{ 1614 /* set_capacity(device->this_bdev->bd_disk, size); */ 1615 set_capacity(device->vdisk, size); 1616 device->this_bdev->bd_inode->i_size = (loff_t)size << 9; 1617} 1618 1619/* 1620 * used to submit our private bio 1621 */ 1622static inline void drbd_generic_make_request(struct drbd_device *device, 1623 int fault_type, struct bio *bio) 1624{ 1625 __release(local); 1626 if (!bio->bi_bdev) { 1627 drbd_err(device, "drbd_generic_make_request: bio->bi_bdev == NULL\n"); 1628 bio_endio(bio, -ENODEV); 1629 return; 1630 } 1631 1632 if (drbd_insert_fault(device, fault_type)) 1633 bio_endio(bio, -EIO); 1634 else 1635 generic_make_request(bio); 1636} 1637 1638void drbd_bump_write_ordering(struct drbd_resource *resource, struct drbd_backing_dev *bdev, 1639 enum write_ordering_e wo); 1640 1641/* drbd_proc.c */ 1642extern struct proc_dir_entry *drbd_proc; 1643extern const struct file_operations drbd_proc_fops; 1644extern const char *drbd_conn_str(enum drbd_conns s); 1645extern const char *drbd_role_str(enum drbd_role s); 1646 1647/* drbd_actlog.c */ 1648extern bool drbd_al_begin_io_prepare(struct drbd_device *device, struct drbd_interval *i); 1649extern int drbd_al_begin_io_nonblock(struct drbd_device *device, struct drbd_interval *i); 1650extern void drbd_al_begin_io_commit(struct drbd_device *device); 1651extern bool drbd_al_begin_io_fastpath(struct drbd_device *device, struct drbd_interval *i); 1652extern void drbd_al_begin_io(struct drbd_device *device, struct drbd_interval *i); 1653extern void drbd_al_complete_io(struct drbd_device *device, struct drbd_interval *i); 1654extern void drbd_rs_complete_io(struct drbd_device *device, sector_t sector); 1655extern int drbd_rs_begin_io(struct drbd_device *device, sector_t sector); 1656extern int drbd_try_rs_begin_io(struct drbd_device *device, sector_t sector); 1657extern void drbd_rs_cancel_all(struct drbd_device *device); 1658extern int drbd_rs_del_all(struct drbd_device *device); 1659extern void drbd_rs_failed_io(struct drbd_device *device, 1660 sector_t sector, int size); 1661extern void drbd_advance_rs_marks(struct drbd_device *device, unsigned long still_to_go); 1662 1663enum update_sync_bits_mode { RECORD_RS_FAILED, SET_OUT_OF_SYNC, SET_IN_SYNC }; 1664extern int __drbd_change_sync(struct drbd_device *device, sector_t sector, int size, 1665 enum update_sync_bits_mode mode, 1666 const char *file, const unsigned int line); 1667#define drbd_set_in_sync(device, sector, size) \ 1668 __drbd_change_sync(device, sector, size, SET_IN_SYNC, __FILE__, __LINE__) 1669#define drbd_set_out_of_sync(device, sector, size) \ 1670 __drbd_change_sync(device, sector, size, SET_OUT_OF_SYNC, __FILE__, __LINE__) 1671#define drbd_rs_failed_io(device, sector, size) \ 1672 __drbd_change_sync(device, sector, size, RECORD_RS_FAILED, __FILE__, __LINE__) 1673extern void drbd_al_shrink(struct drbd_device *device); 1674extern int drbd_initialize_al(struct drbd_device *, void *); 1675 1676/* drbd_nl.c */ 1677/* state info broadcast */ 1678struct sib_info { 1679 enum drbd_state_info_bcast_reason sib_reason; 1680 union { 1681 struct { 1682 char *helper_name; 1683 unsigned helper_exit_code; 1684 }; 1685 struct { 1686 union drbd_state os; 1687 union drbd_state ns; 1688 }; 1689 }; 1690}; 1691void drbd_bcast_event(struct drbd_device *device, const struct sib_info *sib); 1692 1693/* 1694 * inline helper functions 1695 *************************/ 1696 1697/* see also page_chain_add and friends in drbd_receiver.c */ 1698static inline struct page *page_chain_next(struct page *page) 1699{ 1700 return (struct page *)page_private(page); 1701} 1702#define page_chain_for_each(page) \ 1703 for (; page && ({ prefetch(page_chain_next(page)); 1; }); \ 1704 page = page_chain_next(page)) 1705#define page_chain_for_each_safe(page, n) \ 1706 for (; page && ({ n = page_chain_next(page); 1; }); page = n) 1707 1708 1709static inline int drbd_peer_req_has_active_page(struct drbd_peer_request *peer_req) 1710{ 1711 struct page *page = peer_req->pages; 1712 page_chain_for_each(page) { 1713 if (page_count(page) > 1) 1714 return 1; 1715 } 1716 return 0; 1717} 1718 1719static inline enum drbd_state_rv 1720_drbd_set_state(struct drbd_device *device, union drbd_state ns, 1721 enum chg_state_flags flags, struct completion *done) 1722{ 1723 enum drbd_state_rv rv; 1724 1725 read_lock(&global_state_lock); 1726 rv = __drbd_set_state(device, ns, flags, done); 1727 read_unlock(&global_state_lock); 1728 1729 return rv; 1730} 1731 1732static inline union drbd_state drbd_read_state(struct drbd_device *device) 1733{ 1734 struct drbd_resource *resource = device->resource; 1735 union drbd_state rv; 1736 1737 rv.i = device->state.i; 1738 rv.susp = resource->susp; 1739 rv.susp_nod = resource->susp_nod; 1740 rv.susp_fen = resource->susp_fen; 1741 1742 return rv; 1743} 1744 1745enum drbd_force_detach_flags { 1746 DRBD_READ_ERROR, 1747 DRBD_WRITE_ERROR, 1748 DRBD_META_IO_ERROR, 1749 DRBD_FORCE_DETACH, 1750}; 1751 1752#define __drbd_chk_io_error(m,f) __drbd_chk_io_error_(m,f, __func__) 1753static inline void __drbd_chk_io_error_(struct drbd_device *device, 1754 enum drbd_force_detach_flags df, 1755 const char *where) 1756{ 1757 enum drbd_io_error_p ep; 1758 1759 rcu_read_lock(); 1760 ep = rcu_dereference(device->ldev->disk_conf)->on_io_error; 1761 rcu_read_unlock(); 1762 switch (ep) { 1763 case EP_PASS_ON: /* FIXME would this be better named "Ignore"? */ 1764 if (df == DRBD_READ_ERROR || df == DRBD_WRITE_ERROR) { 1765 if (__ratelimit(&drbd_ratelimit_state)) 1766 drbd_err(device, "Local IO failed in %s.\n", where); 1767 if (device->state.disk > D_INCONSISTENT) 1768 _drbd_set_state(_NS(device, disk, D_INCONSISTENT), CS_HARD, NULL); 1769 break; 1770 } 1771 /* NOTE fall through for DRBD_META_IO_ERROR or DRBD_FORCE_DETACH */ 1772 case EP_DETACH: 1773 case EP_CALL_HELPER: 1774 /* Remember whether we saw a READ or WRITE error. 1775 * 1776 * Recovery of the affected area for WRITE failure is covered 1777 * by the activity log. 1778 * READ errors may fall outside that area though. Certain READ 1779 * errors can be "healed" by writing good data to the affected 1780 * blocks, which triggers block re-allocation in lower layers. 1781 * 1782 * If we can not write the bitmap after a READ error, 1783 * we may need to trigger a full sync (see w_go_diskless()). 1784 * 1785 * Force-detach is not really an IO error, but rather a 1786 * desperate measure to try to deal with a completely 1787 * unresponsive lower level IO stack. 1788 * Still it should be treated as a WRITE error. 1789 * 1790 * Meta IO error is always WRITE error: 1791 * we read meta data only once during attach, 1792 * which will fail in case of errors. 1793 */ 1794 set_bit(WAS_IO_ERROR, &device->flags); 1795 if (df == DRBD_READ_ERROR) 1796 set_bit(WAS_READ_ERROR, &device->flags); 1797 if (df == DRBD_FORCE_DETACH) 1798 set_bit(FORCE_DETACH, &device->flags); 1799 if (device->state.disk > D_FAILED) { 1800 _drbd_set_state(_NS(device, disk, D_FAILED), CS_HARD, NULL); 1801 drbd_err(device, 1802 "Local IO failed in %s. Detaching...\n", where); 1803 } 1804 break; 1805 } 1806} 1807 1808/** 1809 * drbd_chk_io_error: Handle the on_io_error setting, should be called from all io completion handlers 1810 * @device: DRBD device. 1811 * @error: Error code passed to the IO completion callback 1812 * @forcedetach: Force detach. I.e. the error happened while accessing the meta data 1813 * 1814 * See also drbd_main.c:after_state_ch() if (os.disk > D_FAILED && ns.disk == D_FAILED) 1815 */ 1816#define drbd_chk_io_error(m,e,f) drbd_chk_io_error_(m,e,f, __func__) 1817static inline void drbd_chk_io_error_(struct drbd_device *device, 1818 int error, enum drbd_force_detach_flags forcedetach, const char *where) 1819{ 1820 if (error) { 1821 unsigned long flags; 1822 spin_lock_irqsave(&device->resource->req_lock, flags); 1823 __drbd_chk_io_error_(device, forcedetach, where); 1824 spin_unlock_irqrestore(&device->resource->req_lock, flags); 1825 } 1826} 1827 1828 1829/** 1830 * drbd_md_first_sector() - Returns the first sector number of the meta data area 1831 * @bdev: Meta data block device. 1832 * 1833 * BTW, for internal meta data, this happens to be the maximum capacity 1834 * we could agree upon with our peer node. 1835 */ 1836static inline sector_t drbd_md_first_sector(struct drbd_backing_dev *bdev) 1837{ 1838 switch (bdev->md.meta_dev_idx) { 1839 case DRBD_MD_INDEX_INTERNAL: 1840 case DRBD_MD_INDEX_FLEX_INT: 1841 return bdev->md.md_offset + bdev->md.bm_offset; 1842 case DRBD_MD_INDEX_FLEX_EXT: 1843 default: 1844 return bdev->md.md_offset; 1845 } 1846} 1847 1848/** 1849 * drbd_md_last_sector() - Return the last sector number of the meta data area 1850 * @bdev: Meta data block device. 1851 */ 1852static inline sector_t drbd_md_last_sector(struct drbd_backing_dev *bdev) 1853{ 1854 switch (bdev->md.meta_dev_idx) { 1855 case DRBD_MD_INDEX_INTERNAL: 1856 case DRBD_MD_INDEX_FLEX_INT: 1857 return bdev->md.md_offset + MD_4kB_SECT -1; 1858 case DRBD_MD_INDEX_FLEX_EXT: 1859 default: 1860 return bdev->md.md_offset + bdev->md.md_size_sect -1; 1861 } 1862} 1863 1864/* Returns the number of 512 byte sectors of the device */ 1865static inline sector_t drbd_get_capacity(struct block_device *bdev) 1866{ 1867 /* return bdev ? get_capacity(bdev->bd_disk) : 0; */ 1868 return bdev ? i_size_read(bdev->bd_inode) >> 9 : 0; 1869} 1870 1871/** 1872 * drbd_get_max_capacity() - Returns the capacity we announce to out peer 1873 * @bdev: Meta data block device. 1874 * 1875 * returns the capacity we announce to out peer. we clip ourselves at the 1876 * various MAX_SECTORS, because if we don't, current implementation will 1877 * oops sooner or later 1878 */ 1879static inline sector_t drbd_get_max_capacity(struct drbd_backing_dev *bdev) 1880{ 1881 sector_t s; 1882 1883 switch (bdev->md.meta_dev_idx) { 1884 case DRBD_MD_INDEX_INTERNAL: 1885 case DRBD_MD_INDEX_FLEX_INT: 1886 s = drbd_get_capacity(bdev->backing_bdev) 1887 ? min_t(sector_t, DRBD_MAX_SECTORS_FLEX, 1888 drbd_md_first_sector(bdev)) 1889 : 0; 1890 break; 1891 case DRBD_MD_INDEX_FLEX_EXT: 1892 s = min_t(sector_t, DRBD_MAX_SECTORS_FLEX, 1893 drbd_get_capacity(bdev->backing_bdev)); 1894 /* clip at maximum size the meta device can support */ 1895 s = min_t(sector_t, s, 1896 BM_EXT_TO_SECT(bdev->md.md_size_sect 1897 - bdev->md.bm_offset)); 1898 break; 1899 default: 1900 s = min_t(sector_t, DRBD_MAX_SECTORS, 1901 drbd_get_capacity(bdev->backing_bdev)); 1902 } 1903 return s; 1904} 1905 1906/** 1907 * drbd_md_ss() - Return the sector number of our meta data super block 1908 * @bdev: Meta data block device. 1909 */ 1910static inline sector_t drbd_md_ss(struct drbd_backing_dev *bdev) 1911{ 1912 const int meta_dev_idx = bdev->md.meta_dev_idx; 1913 1914 if (meta_dev_idx == DRBD_MD_INDEX_FLEX_EXT) 1915 return 0; 1916 1917 /* Since drbd08, internal meta data is always "flexible". 1918 * position: last 4k aligned block of 4k size */ 1919 if (meta_dev_idx == DRBD_MD_INDEX_INTERNAL || 1920 meta_dev_idx == DRBD_MD_INDEX_FLEX_INT) 1921 return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL) - 8; 1922 1923 /* external, some index; this is the old fixed size layout */ 1924 return MD_128MB_SECT * bdev->md.meta_dev_idx; 1925} 1926 1927static inline void 1928drbd_queue_work(struct drbd_work_queue *q, struct drbd_work *w) 1929{ 1930 unsigned long flags; 1931 spin_lock_irqsave(&q->q_lock, flags); 1932 list_add_tail(&w->list, &q->q); 1933 spin_unlock_irqrestore(&q->q_lock, flags); 1934 wake_up(&q->q_wait); 1935} 1936 1937static inline void 1938drbd_queue_work_if_unqueued(struct drbd_work_queue *q, struct drbd_work *w) 1939{ 1940 unsigned long flags; 1941 spin_lock_irqsave(&q->q_lock, flags); 1942 if (list_empty_careful(&w->list)) 1943 list_add_tail(&w->list, &q->q); 1944 spin_unlock_irqrestore(&q->q_lock, flags); 1945 wake_up(&q->q_wait); 1946} 1947 1948static inline void 1949drbd_device_post_work(struct drbd_device *device, int work_bit) 1950{ 1951 if (!test_and_set_bit(work_bit, &device->flags)) { 1952 struct drbd_connection *connection = 1953 first_peer_device(device)->connection; 1954 struct drbd_work_queue *q = &connection->sender_work; 1955 if (!test_and_set_bit(DEVICE_WORK_PENDING, &connection->flags)) 1956 wake_up(&q->q_wait); 1957 } 1958} 1959 1960extern void drbd_flush_workqueue(struct drbd_work_queue *work_queue); 1961 1962static inline void wake_asender(struct drbd_connection *connection) 1963{ 1964 if (test_bit(SIGNAL_ASENDER, &connection->flags)) 1965 force_sig(DRBD_SIG, connection->asender.task); 1966} 1967 1968static inline void request_ping(struct drbd_connection *connection) 1969{ 1970 set_bit(SEND_PING, &connection->flags); 1971 wake_asender(connection); 1972} 1973 1974extern void *conn_prepare_command(struct drbd_connection *, struct drbd_socket *); 1975extern void *drbd_prepare_command(struct drbd_peer_device *, struct drbd_socket *); 1976extern int conn_send_command(struct drbd_connection *, struct drbd_socket *, 1977 enum drbd_packet, unsigned int, void *, 1978 unsigned int); 1979extern int drbd_send_command(struct drbd_peer_device *, struct drbd_socket *, 1980 enum drbd_packet, unsigned int, void *, 1981 unsigned int); 1982 1983extern int drbd_send_ping(struct drbd_connection *connection); 1984extern int drbd_send_ping_ack(struct drbd_connection *connection); 1985extern int drbd_send_state_req(struct drbd_peer_device *, union drbd_state, union drbd_state); 1986extern int conn_send_state_req(struct drbd_connection *, union drbd_state, union drbd_state); 1987 1988static inline void drbd_thread_stop(struct drbd_thread *thi) 1989{ 1990 _drbd_thread_stop(thi, false, true); 1991} 1992 1993static inline void drbd_thread_stop_nowait(struct drbd_thread *thi) 1994{ 1995 _drbd_thread_stop(thi, false, false); 1996} 1997 1998static inline void drbd_thread_restart_nowait(struct drbd_thread *thi) 1999{ 2000 _drbd_thread_stop(thi, true, false); 2001} 2002 2003/* counts how many answer packets packets we expect from our peer, 2004 * for either explicit application requests, 2005 * or implicit barrier packets as necessary. 2006 * increased: 2007 * w_send_barrier 2008 * _req_mod(req, QUEUE_FOR_NET_WRITE or QUEUE_FOR_NET_READ); 2009 * it is much easier and equally valid to count what we queue for the 2010 * worker, even before it actually was queued or send. 2011 * (drbd_make_request_common; recovery path on read io-error) 2012 * decreased: 2013 * got_BarrierAck (respective tl_clear, tl_clear_barrier) 2014 * _req_mod(req, DATA_RECEIVED) 2015 * [from receive_DataReply] 2016 * _req_mod(req, WRITE_ACKED_BY_PEER or RECV_ACKED_BY_PEER or NEG_ACKED) 2017 * [from got_BlockAck (P_WRITE_ACK, P_RECV_ACK)] 2018 * for some reason it is NOT decreased in got_NegAck, 2019 * but in the resulting cleanup code from report_params. 2020 * we should try to remember the reason for that... 2021 * _req_mod(req, SEND_FAILED or SEND_CANCELED) 2022 * _req_mod(req, CONNECTION_LOST_WHILE_PENDING) 2023 * [from tl_clear_barrier] 2024 */ 2025static inline void inc_ap_pending(struct drbd_device *device) 2026{ 2027 atomic_inc(&device->ap_pending_cnt); 2028} 2029 2030#define ERR_IF_CNT_IS_NEGATIVE(which, func, line) \ 2031 if (atomic_read(&device->which) < 0) \ 2032 drbd_err(device, "in %s:%d: " #which " = %d < 0 !\n", \ 2033 func, line, \ 2034 atomic_read(&device->which)) 2035 2036#define dec_ap_pending(device) _dec_ap_pending(device, __func__, __LINE__) 2037static inline void _dec_ap_pending(struct drbd_device *device, const char *func, int line) 2038{ 2039 if (atomic_dec_and_test(&device->ap_pending_cnt)) 2040 wake_up(&device->misc_wait); 2041 ERR_IF_CNT_IS_NEGATIVE(ap_pending_cnt, func, line); 2042} 2043 2044/* counts how many resync-related answers we still expect from the peer 2045 * increase decrease 2046 * C_SYNC_TARGET sends P_RS_DATA_REQUEST (and expects P_RS_DATA_REPLY) 2047 * C_SYNC_SOURCE sends P_RS_DATA_REPLY (and expects P_WRITE_ACK with ID_SYNCER) 2048 * (or P_NEG_ACK with ID_SYNCER) 2049 */ 2050static inline void inc_rs_pending(struct drbd_device *device) 2051{ 2052 atomic_inc(&device->rs_pending_cnt); 2053} 2054 2055#define dec_rs_pending(device) _dec_rs_pending(device, __func__, __LINE__) 2056static inline void _dec_rs_pending(struct drbd_device *device, const char *func, int line) 2057{ 2058 atomic_dec(&device->rs_pending_cnt); 2059 ERR_IF_CNT_IS_NEGATIVE(rs_pending_cnt, func, line); 2060} 2061 2062/* counts how many answers we still need to send to the peer. 2063 * increased on 2064 * receive_Data unless protocol A; 2065 * we need to send a P_RECV_ACK (proto B) 2066 * or P_WRITE_ACK (proto C) 2067 * receive_RSDataReply (recv_resync_read) we need to send a P_WRITE_ACK 2068 * receive_DataRequest (receive_RSDataRequest) we need to send back P_DATA 2069 * receive_Barrier_* we need to send a P_BARRIER_ACK 2070 */ 2071static inline void inc_unacked(struct drbd_device *device) 2072{ 2073 atomic_inc(&device->unacked_cnt); 2074} 2075 2076#define dec_unacked(device) _dec_unacked(device, __func__, __LINE__) 2077static inline void _dec_unacked(struct drbd_device *device, const char *func, int line) 2078{ 2079 atomic_dec(&device->unacked_cnt); 2080 ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line); 2081} 2082 2083#define sub_unacked(device, n) _sub_unacked(device, n, __func__, __LINE__) 2084static inline void _sub_unacked(struct drbd_device *device, int n, const char *func, int line) 2085{ 2086 atomic_sub(n, &device->unacked_cnt); 2087 ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line); 2088} 2089 2090static inline bool is_sync_state(enum drbd_conns connection_state) 2091{ 2092 return 2093 (connection_state == C_SYNC_SOURCE 2094 || connection_state == C_SYNC_TARGET 2095 || connection_state == C_PAUSED_SYNC_S 2096 || connection_state == C_PAUSED_SYNC_T); 2097} 2098 2099/** 2100 * get_ldev() - Increase the ref count on device->ldev. Returns 0 if there is no ldev 2101 * @_device: DRBD device. 2102 * @_min_state: Minimum device state required for success. 2103 * 2104 * You have to call put_ldev() when finished working with device->ldev. 2105 */ 2106#define get_ldev_if_state(_device, _min_state) \ 2107 (_get_ldev_if_state((_device), (_min_state)) ? \ 2108 ({ __acquire(x); true; }) : false) 2109#define get_ldev(_device) get_ldev_if_state(_device, D_INCONSISTENT) 2110 2111static inline void put_ldev(struct drbd_device *device) 2112{ 2113 enum drbd_disk_state disk_state = device->state.disk; 2114 /* We must check the state *before* the atomic_dec becomes visible, 2115 * or we have a theoretical race where someone hitting zero, 2116 * while state still D_FAILED, will then see D_DISKLESS in the 2117 * condition below and calling into destroy, where he must not, yet. */ 2118 int i = atomic_dec_return(&device->local_cnt); 2119 2120 /* This may be called from some endio handler, 2121 * so we must not sleep here. */ 2122 2123 __release(local); 2124 D_ASSERT(device, i >= 0); 2125 if (i == 0) { 2126 if (disk_state == D_DISKLESS) 2127 /* even internal references gone, safe to destroy */ 2128 drbd_device_post_work(device, DESTROY_DISK); 2129 if (disk_state == D_FAILED) 2130 /* all application IO references gone. */ 2131 if (!test_and_set_bit(GOING_DISKLESS, &device->flags)) 2132 drbd_device_post_work(device, GO_DISKLESS); 2133 wake_up(&device->misc_wait); 2134 } 2135} 2136 2137#ifndef __CHECKER__ 2138static inline int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins) 2139{ 2140 int io_allowed; 2141 2142 /* never get a reference while D_DISKLESS */ 2143 if (device->state.disk == D_DISKLESS) 2144 return 0; 2145 2146 atomic_inc(&device->local_cnt); 2147 io_allowed = (device->state.disk >= mins); 2148 if (!io_allowed) 2149 put_ldev(device); 2150 return io_allowed; 2151} 2152#else 2153extern int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins); 2154#endif 2155 2156/* this throttles on-the-fly application requests 2157 * according to max_buffers settings; 2158 * maybe re-implement using semaphores? */ 2159static inline int drbd_get_max_buffers(struct drbd_device *device) 2160{ 2161 struct net_conf *nc; 2162 int mxb; 2163 2164 rcu_read_lock(); 2165 nc = rcu_dereference(first_peer_device(device)->connection->net_conf); 2166 mxb = nc ? nc->max_buffers : 1000000; /* arbitrary limit on open requests */ 2167 rcu_read_unlock(); 2168 2169 return mxb; 2170} 2171 2172static inline int drbd_state_is_stable(struct drbd_device *device) 2173{ 2174 union drbd_dev_state s = device->state; 2175 2176 /* DO NOT add a default clause, we want the compiler to warn us 2177 * for any newly introduced state we may have forgotten to add here */ 2178 2179 switch ((enum drbd_conns)s.conn) { 2180 /* new io only accepted when there is no connection, ... */ 2181 case C_STANDALONE: 2182 case C_WF_CONNECTION: 2183 /* ... or there is a well established connection. */ 2184 case C_CONNECTED: 2185 case C_SYNC_SOURCE: 2186 case C_SYNC_TARGET: 2187 case C_VERIFY_S: 2188 case C_VERIFY_T: 2189 case C_PAUSED_SYNC_S: 2190 case C_PAUSED_SYNC_T: 2191 case C_AHEAD: 2192 case C_BEHIND: 2193 /* transitional states, IO allowed */ 2194 case C_DISCONNECTING: 2195 case C_UNCONNECTED: 2196 case C_TIMEOUT: 2197 case C_BROKEN_PIPE: 2198 case C_NETWORK_FAILURE: 2199 case C_PROTOCOL_ERROR: 2200 case C_TEAR_DOWN: 2201 case C_WF_REPORT_PARAMS: 2202 case C_STARTING_SYNC_S: 2203 case C_STARTING_SYNC_T: 2204 break; 2205 2206 /* Allow IO in BM exchange states with new protocols */ 2207 case C_WF_BITMAP_S: 2208 if (first_peer_device(device)->connection->agreed_pro_version < 96) 2209 return 0; 2210 break; 2211 2212 /* no new io accepted in these states */ 2213 case C_WF_BITMAP_T: 2214 case C_WF_SYNC_UUID: 2215 case C_MASK: 2216 /* not "stable" */ 2217 return 0; 2218 } 2219 2220 switch ((enum drbd_disk_state)s.disk) { 2221 case D_DISKLESS: 2222 case D_INCONSISTENT: 2223 case D_OUTDATED: 2224 case D_CONSISTENT: 2225 case D_UP_TO_DATE: 2226 case D_FAILED: 2227 /* disk state is stable as well. */ 2228 break; 2229 2230 /* no new io accepted during transitional states */ 2231 case D_ATTACHING: 2232 case D_NEGOTIATING: 2233 case D_UNKNOWN: 2234 case D_MASK: 2235 /* not "stable" */ 2236 return 0; 2237 } 2238 2239 return 1; 2240} 2241 2242static inline int drbd_suspended(struct drbd_device *device) 2243{ 2244 struct drbd_resource *resource = device->resource; 2245 2246 return resource->susp || resource->susp_fen || resource->susp_nod; 2247} 2248 2249static inline bool may_inc_ap_bio(struct drbd_device *device) 2250{ 2251 int mxb = drbd_get_max_buffers(device); 2252 2253 if (drbd_suspended(device)) 2254 return false; 2255 if (test_bit(SUSPEND_IO, &device->flags)) 2256 return false; 2257 2258 /* to avoid potential deadlock or bitmap corruption, 2259 * in various places, we only allow new application io 2260 * to start during "stable" states. */ 2261 2262 /* no new io accepted when attaching or detaching the disk */ 2263 if (!drbd_state_is_stable(device)) 2264 return false; 2265 2266 /* since some older kernels don't have atomic_add_unless, 2267 * and we are within the spinlock anyways, we have this workaround. */ 2268 if (atomic_read(&device->ap_bio_cnt) > mxb) 2269 return false; 2270 if (test_bit(BITMAP_IO, &device->flags)) 2271 return false; 2272 return true; 2273} 2274 2275static inline bool inc_ap_bio_cond(struct drbd_device *device) 2276{ 2277 bool rv = false; 2278 2279 spin_lock_irq(&device->resource->req_lock); 2280 rv = may_inc_ap_bio(device); 2281 if (rv) 2282 atomic_inc(&device->ap_bio_cnt); 2283 spin_unlock_irq(&device->resource->req_lock); 2284 2285 return rv; 2286} 2287 2288static inline void inc_ap_bio(struct drbd_device *device) 2289{ 2290 /* we wait here 2291 * as long as the device is suspended 2292 * until the bitmap is no longer on the fly during connection 2293 * handshake as long as we would exceed the max_buffer limit. 2294 * 2295 * to avoid races with the reconnect code, 2296 * we need to atomic_inc within the spinlock. */ 2297 2298 wait_event(device->misc_wait, inc_ap_bio_cond(device)); 2299} 2300 2301static inline void dec_ap_bio(struct drbd_device *device) 2302{ 2303 int mxb = drbd_get_max_buffers(device); 2304 int ap_bio = atomic_dec_return(&device->ap_bio_cnt); 2305 2306 D_ASSERT(device, ap_bio >= 0); 2307 2308 if (ap_bio == 0 && test_bit(BITMAP_IO, &device->flags)) { 2309 if (!test_and_set_bit(BITMAP_IO_QUEUED, &device->flags)) 2310 drbd_queue_work(&first_peer_device(device)-> 2311 connection->sender_work, 2312 &device->bm_io_work.w); 2313 } 2314 2315 /* this currently does wake_up for every dec_ap_bio! 2316 * maybe rather introduce some type of hysteresis? 2317 * e.g. (ap_bio == mxb/2 || ap_bio == 0) ? */ 2318 if (ap_bio < mxb) 2319 wake_up(&device->misc_wait); 2320} 2321 2322static inline bool verify_can_do_stop_sector(struct drbd_device *device) 2323{ 2324 return first_peer_device(device)->connection->agreed_pro_version >= 97 && 2325 first_peer_device(device)->connection->agreed_pro_version != 100; 2326} 2327 2328static inline int drbd_set_ed_uuid(struct drbd_device *device, u64 val) 2329{ 2330 int changed = device->ed_uuid != val; 2331 device->ed_uuid = val; 2332 return changed; 2333} 2334 2335static inline int drbd_queue_order_type(struct drbd_device *device) 2336{ 2337 /* sorry, we currently have no working implementation 2338 * of distributed TCQ stuff */ 2339#ifndef QUEUE_ORDERED_NONE 2340#define QUEUE_ORDERED_NONE 0 2341#endif 2342 return QUEUE_ORDERED_NONE; 2343} 2344 2345static inline struct drbd_connection *first_connection(struct drbd_resource *resource) 2346{ 2347 return list_first_entry_or_null(&resource->connections, 2348 struct drbd_connection, connections); 2349} 2350 2351#endif 2352