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 <crypto/hash.h> 30 #include <linux/compiler.h> 31 #include <linux/types.h> 32 #include <linux/list.h> 33 #include <linux/sched.h> 34 #include <linux/bitops.h> 35 #include <linux/slab.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/backing-dev.h> 42 #include <linux/genhd.h> 43 #include <linux/idr.h> 44 #include <linux/dynamic_debug.h> 45 #include <net/tcp.h> 46 #include <linux/lru_cache.h> 47 #include <linux/prefetch.h> 48 #include <linux/drbd_genl_api.h> 49 #include <linux/drbd.h> 50 #include "drbd_strings.h" 51 #include "drbd_state.h" 52 #include "drbd_protocol.h" 53 54 #ifdef __CHECKER__ 55 # define __protected_by(x) __attribute__((require_context(x,1,999,"rdwr"))) 56 # define __protected_read_by(x) __attribute__((require_context(x,1,999,"read"))) 57 # define __protected_write_by(x) __attribute__((require_context(x,1,999,"write"))) 58 # define __must_hold(x) __attribute__((context(x,1,1), require_context(x,1,999,"call"))) 59 #else 60 # define __protected_by(x) 61 # define __protected_read_by(x) 62 # define __protected_write_by(x) 63 # define __must_hold(x) 64 #endif 65 66 /* module parameter, defined in drbd_main.c */ 67 extern unsigned int minor_count; 68 extern bool disable_sendpage; 69 extern bool allow_oos; 70 void tl_abort_disk_io(struct drbd_device *device); 71 72 #ifdef CONFIG_DRBD_FAULT_INJECTION 73 extern int enable_faults; 74 extern int fault_rate; 75 extern int fault_devs; 76 #endif 77 78 extern char usermode_helper[]; 79 80 81 /* This is used to stop/restart our threads. 82 * Cannot use SIGTERM nor SIGKILL, since these 83 * are sent out by init on runlevel changes 84 * I choose SIGHUP for now. 85 */ 86 #define DRBD_SIGKILL SIGHUP 87 88 #define ID_IN_SYNC (4711ULL) 89 #define ID_OUT_OF_SYNC (4712ULL) 90 #define ID_SYNCER (-1ULL) 91 92 #define UUID_NEW_BM_OFFSET ((u64)0x0001000000000000ULL) 93 94 struct drbd_device; 95 struct drbd_connection; 96 97 #define __drbd_printk_device(level, device, fmt, args...) \ 98 dev_printk(level, disk_to_dev((device)->vdisk), fmt, ## args) 99 #define __drbd_printk_peer_device(level, peer_device, fmt, args...) \ 100 dev_printk(level, disk_to_dev((peer_device)->device->vdisk), fmt, ## args) 101 #define __drbd_printk_resource(level, resource, fmt, args...) \ 102 printk(level "drbd %s: " fmt, (resource)->name, ## args) 103 #define __drbd_printk_connection(level, connection, fmt, args...) \ 104 printk(level "drbd %s: " fmt, (connection)->resource->name, ## args) 105 106 void drbd_printk_with_wrong_object_type(void); 107 108 #define __drbd_printk_if_same_type(obj, type, func, level, fmt, args...) \ 109 (__builtin_types_compatible_p(typeof(obj), type) || \ 110 __builtin_types_compatible_p(typeof(obj), const type)), \ 111 func(level, (const type)(obj), fmt, ## args) 112 113 #define drbd_printk(level, obj, fmt, args...) \ 114 __builtin_choose_expr( \ 115 __drbd_printk_if_same_type(obj, struct drbd_device *, \ 116 __drbd_printk_device, level, fmt, ## args), \ 117 __builtin_choose_expr( \ 118 __drbd_printk_if_same_type(obj, struct drbd_resource *, \ 119 __drbd_printk_resource, level, fmt, ## args), \ 120 __builtin_choose_expr( \ 121 __drbd_printk_if_same_type(obj, struct drbd_connection *, \ 122 __drbd_printk_connection, level, fmt, ## args), \ 123 __builtin_choose_expr( \ 124 __drbd_printk_if_same_type(obj, struct drbd_peer_device *, \ 125 __drbd_printk_peer_device, level, fmt, ## args), \ 126 drbd_printk_with_wrong_object_type())))) 127 128 #define drbd_dbg(obj, fmt, args...) \ 129 drbd_printk(KERN_DEBUG, obj, fmt, ## args) 130 #define drbd_alert(obj, fmt, args...) \ 131 drbd_printk(KERN_ALERT, obj, fmt, ## args) 132 #define drbd_err(obj, fmt, args...) \ 133 drbd_printk(KERN_ERR, obj, fmt, ## args) 134 #define drbd_warn(obj, fmt, args...) \ 135 drbd_printk(KERN_WARNING, obj, fmt, ## args) 136 #define drbd_info(obj, fmt, args...) \ 137 drbd_printk(KERN_INFO, obj, fmt, ## args) 138 #define drbd_emerg(obj, fmt, args...) \ 139 drbd_printk(KERN_EMERG, obj, fmt, ## args) 140 141 #define dynamic_drbd_dbg(device, fmt, args...) \ 142 dynamic_dev_dbg(disk_to_dev(device->vdisk), fmt, ## args) 143 144 #define D_ASSERT(device, exp) do { \ 145 if (!(exp)) \ 146 drbd_err(device, "ASSERT( " #exp " ) in %s:%d\n", __FILE__, __LINE__); \ 147 } while (0) 148 149 /** 150 * expect - Make an assertion 151 * 152 * Unlike the assert macro, this macro returns a boolean result. 153 */ 154 #define expect(exp) ({ \ 155 bool _bool = (exp); \ 156 if (!_bool) \ 157 drbd_err(device, "ASSERTION %s FAILED in %s\n", \ 158 #exp, __func__); \ 159 _bool; \ 160 }) 161 162 /* Defines to control fault insertion */ 163 enum { 164 DRBD_FAULT_MD_WR = 0, /* meta data write */ 165 DRBD_FAULT_MD_RD = 1, /* read */ 166 DRBD_FAULT_RS_WR = 2, /* resync */ 167 DRBD_FAULT_RS_RD = 3, 168 DRBD_FAULT_DT_WR = 4, /* data */ 169 DRBD_FAULT_DT_RD = 5, 170 DRBD_FAULT_DT_RA = 6, /* data read ahead */ 171 DRBD_FAULT_BM_ALLOC = 7, /* bitmap allocation */ 172 DRBD_FAULT_AL_EE = 8, /* alloc ee */ 173 DRBD_FAULT_RECEIVE = 9, /* Changes some bytes upon receiving a [rs]data block */ 174 175 DRBD_FAULT_MAX, 176 }; 177 178 extern unsigned int 179 _drbd_insert_fault(struct drbd_device *device, unsigned int type); 180 181 static inline int 182 drbd_insert_fault(struct drbd_device *device, unsigned int type) { 183 #ifdef CONFIG_DRBD_FAULT_INJECTION 184 return fault_rate && 185 (enable_faults & (1<<type)) && 186 _drbd_insert_fault(device, type); 187 #else 188 return 0; 189 #endif 190 } 191 192 /* integer division, round _UP_ to the next integer */ 193 #define div_ceil(A, B) ((A)/(B) + ((A)%(B) ? 1 : 0)) 194 /* usual integer division */ 195 #define div_floor(A, B) ((A)/(B)) 196 197 extern struct ratelimit_state drbd_ratelimit_state; 198 extern struct idr drbd_devices; /* RCU, updates: genl_lock() */ 199 extern struct list_head drbd_resources; /* RCU, updates: genl_lock() */ 200 201 extern const char *cmdname(enum drbd_packet cmd); 202 203 /* for sending/receiving the bitmap, 204 * possibly in some encoding scheme */ 205 struct bm_xfer_ctx { 206 /* "const" 207 * stores total bits and long words 208 * of the bitmap, so we don't need to 209 * call the accessor functions over and again. */ 210 unsigned long bm_bits; 211 unsigned long bm_words; 212 /* during xfer, current position within the bitmap */ 213 unsigned long bit_offset; 214 unsigned long word_offset; 215 216 /* statistics; index: (h->command == P_BITMAP) */ 217 unsigned packets[2]; 218 unsigned bytes[2]; 219 }; 220 221 extern void INFO_bm_xfer_stats(struct drbd_device *device, 222 const char *direction, struct bm_xfer_ctx *c); 223 224 static inline void bm_xfer_ctx_bit_to_word_offset(struct bm_xfer_ctx *c) 225 { 226 /* word_offset counts "native long words" (32 or 64 bit), 227 * aligned at 64 bit. 228 * Encoded packet may end at an unaligned bit offset. 229 * In case a fallback clear text packet is transmitted in 230 * between, we adjust this offset back to the last 64bit 231 * aligned "native long word", which makes coding and decoding 232 * the plain text bitmap much more convenient. */ 233 #if BITS_PER_LONG == 64 234 c->word_offset = c->bit_offset >> 6; 235 #elif BITS_PER_LONG == 32 236 c->word_offset = c->bit_offset >> 5; 237 c->word_offset &= ~(1UL); 238 #else 239 # error "unsupported BITS_PER_LONG" 240 #endif 241 } 242 243 extern unsigned int drbd_header_size(struct drbd_connection *connection); 244 245 /**********************************************************************/ 246 enum drbd_thread_state { 247 NONE, 248 RUNNING, 249 EXITING, 250 RESTARTING 251 }; 252 253 struct drbd_thread { 254 spinlock_t t_lock; 255 struct task_struct *task; 256 struct completion stop; 257 enum drbd_thread_state t_state; 258 int (*function) (struct drbd_thread *); 259 struct drbd_resource *resource; 260 struct drbd_connection *connection; 261 int reset_cpu_mask; 262 const char *name; 263 }; 264 265 static inline enum drbd_thread_state get_t_state(struct drbd_thread *thi) 266 { 267 /* THINK testing the t_state seems to be uncritical in all cases 268 * (but thread_{start,stop}), so we can read it *without* the lock. 269 * --lge */ 270 271 smp_rmb(); 272 return thi->t_state; 273 } 274 275 struct drbd_work { 276 struct list_head list; 277 int (*cb)(struct drbd_work *, int cancel); 278 }; 279 280 struct drbd_device_work { 281 struct drbd_work w; 282 struct drbd_device *device; 283 }; 284 285 #include "drbd_interval.h" 286 287 extern int drbd_wait_misc(struct drbd_device *, struct drbd_interval *); 288 289 extern void lock_all_resources(void); 290 extern void unlock_all_resources(void); 291 292 struct drbd_request { 293 struct drbd_work w; 294 struct drbd_device *device; 295 296 /* if local IO is not allowed, will be NULL. 297 * if local IO _is_ allowed, holds the locally submitted bio clone, 298 * or, after local IO completion, the ERR_PTR(error). 299 * see drbd_request_endio(). */ 300 struct bio *private_bio; 301 302 struct drbd_interval i; 303 304 /* epoch: used to check on "completion" whether this req was in 305 * the current epoch, and we therefore have to close it, 306 * causing a p_barrier packet to be send, starting a new epoch. 307 * 308 * This corresponds to "barrier" in struct p_barrier[_ack], 309 * and to "barrier_nr" in struct drbd_epoch (and various 310 * comments/function parameters/local variable names). 311 */ 312 unsigned int epoch; 313 314 struct list_head tl_requests; /* ring list in the transfer log */ 315 struct bio *master_bio; /* master bio pointer */ 316 317 /* see struct drbd_device */ 318 struct list_head req_pending_master_completion; 319 struct list_head req_pending_local; 320 321 /* for generic IO accounting */ 322 unsigned long start_jif; 323 324 /* for DRBD internal statistics */ 325 326 /* Minimal set of time stamps to determine if we wait for activity log 327 * transactions, local disk or peer. 32 bit "jiffies" are good enough, 328 * we don't expect a DRBD request to be stalled for several month. 329 */ 330 331 /* before actual request processing */ 332 unsigned long in_actlog_jif; 333 334 /* local disk */ 335 unsigned long pre_submit_jif; 336 337 /* per connection */ 338 unsigned long pre_send_jif; 339 unsigned long acked_jif; 340 unsigned long net_done_jif; 341 342 /* Possibly even more detail to track each phase: 343 * master_completion_jif 344 * how long did it take to complete the master bio 345 * (application visible latency) 346 * allocated_jif 347 * how long the master bio was blocked until we finally allocated 348 * a tracking struct 349 * in_actlog_jif 350 * how long did we wait for activity log transactions 351 * 352 * net_queued_jif 353 * when did we finally queue it for sending 354 * pre_send_jif 355 * when did we start sending it 356 * post_send_jif 357 * how long did we block in the network stack trying to send it 358 * acked_jif 359 * when did we receive (or fake, in protocol A) a remote ACK 360 * net_done_jif 361 * when did we receive final acknowledgement (P_BARRIER_ACK), 362 * or decide, e.g. on connection loss, that we do no longer expect 363 * anything from this peer for this request. 364 * 365 * pre_submit_jif 366 * post_sub_jif 367 * when did we start submiting to the lower level device, 368 * and how long did we block in that submit function 369 * local_completion_jif 370 * how long did it take the lower level device to complete this request 371 */ 372 373 374 /* once it hits 0, we may complete the master_bio */ 375 atomic_t completion_ref; 376 /* once it hits 0, we may destroy this drbd_request object */ 377 struct kref kref; 378 379 unsigned rq_state; /* see comments above _req_mod() */ 380 }; 381 382 struct drbd_epoch { 383 struct drbd_connection *connection; 384 struct list_head list; 385 unsigned int barrier_nr; 386 atomic_t epoch_size; /* increased on every request added. */ 387 atomic_t active; /* increased on every req. added, and dec on every finished. */ 388 unsigned long flags; 389 }; 390 391 /* Prototype declaration of function defined in drbd_receiver.c */ 392 int drbdd_init(struct drbd_thread *); 393 int drbd_asender(struct drbd_thread *); 394 395 /* drbd_epoch flag bits */ 396 enum { 397 DE_HAVE_BARRIER_NUMBER, 398 }; 399 400 enum epoch_event { 401 EV_PUT, 402 EV_GOT_BARRIER_NR, 403 EV_BECAME_LAST, 404 EV_CLEANUP = 32, /* used as flag */ 405 }; 406 407 struct digest_info { 408 int digest_size; 409 void *digest; 410 }; 411 412 struct drbd_peer_request { 413 struct drbd_work w; 414 struct drbd_peer_device *peer_device; 415 struct drbd_epoch *epoch; /* for writes */ 416 struct page *pages; 417 atomic_t pending_bios; 418 struct drbd_interval i; 419 /* see comments on ee flag bits below */ 420 unsigned long flags; 421 unsigned long submit_jif; 422 union { 423 u64 block_id; 424 struct digest_info *digest; 425 }; 426 }; 427 428 /* ee flag bits. 429 * While corresponding bios are in flight, the only modification will be 430 * set_bit WAS_ERROR, which has to be atomic. 431 * If no bios are in flight yet, or all have been completed, 432 * non-atomic modification to ee->flags is ok. 433 */ 434 enum { 435 __EE_CALL_AL_COMPLETE_IO, 436 __EE_MAY_SET_IN_SYNC, 437 438 /* is this a TRIM aka REQ_DISCARD? */ 439 __EE_IS_TRIM, 440 /* our lower level cannot handle trim, 441 * and we want to fall back to zeroout instead */ 442 __EE_IS_TRIM_USE_ZEROOUT, 443 444 /* In case a barrier failed, 445 * we need to resubmit without the barrier flag. */ 446 __EE_RESUBMITTED, 447 448 /* we may have several bios per peer request. 449 * if any of those fail, we set this flag atomically 450 * from the endio callback */ 451 __EE_WAS_ERROR, 452 453 /* This ee has a pointer to a digest instead of a block id */ 454 __EE_HAS_DIGEST, 455 456 /* Conflicting local requests need to be restarted after this request */ 457 __EE_RESTART_REQUESTS, 458 459 /* The peer wants a write ACK for this (wire proto C) */ 460 __EE_SEND_WRITE_ACK, 461 462 /* Is set when net_conf had two_primaries set while creating this peer_req */ 463 __EE_IN_INTERVAL_TREE, 464 465 /* for debugfs: */ 466 /* has this been submitted, or does it still wait for something else? */ 467 __EE_SUBMITTED, 468 469 /* this is/was a write request */ 470 __EE_WRITE, 471 472 /* this is/was a write same request */ 473 __EE_WRITE_SAME, 474 475 /* this originates from application on peer 476 * (not some resync or verify or other DRBD internal request) */ 477 __EE_APPLICATION, 478 479 /* If it contains only 0 bytes, send back P_RS_DEALLOCATED */ 480 __EE_RS_THIN_REQ, 481 }; 482 #define EE_CALL_AL_COMPLETE_IO (1<<__EE_CALL_AL_COMPLETE_IO) 483 #define EE_MAY_SET_IN_SYNC (1<<__EE_MAY_SET_IN_SYNC) 484 #define EE_IS_TRIM (1<<__EE_IS_TRIM) 485 #define EE_IS_TRIM_USE_ZEROOUT (1<<__EE_IS_TRIM_USE_ZEROOUT) 486 #define EE_RESUBMITTED (1<<__EE_RESUBMITTED) 487 #define EE_WAS_ERROR (1<<__EE_WAS_ERROR) 488 #define EE_HAS_DIGEST (1<<__EE_HAS_DIGEST) 489 #define EE_RESTART_REQUESTS (1<<__EE_RESTART_REQUESTS) 490 #define EE_SEND_WRITE_ACK (1<<__EE_SEND_WRITE_ACK) 491 #define EE_IN_INTERVAL_TREE (1<<__EE_IN_INTERVAL_TREE) 492 #define EE_SUBMITTED (1<<__EE_SUBMITTED) 493 #define EE_WRITE (1<<__EE_WRITE) 494 #define EE_WRITE_SAME (1<<__EE_WRITE_SAME) 495 #define EE_APPLICATION (1<<__EE_APPLICATION) 496 #define EE_RS_THIN_REQ (1<<__EE_RS_THIN_REQ) 497 498 /* flag bits per device */ 499 enum { 500 UNPLUG_REMOTE, /* sending a "UnplugRemote" could help */ 501 MD_DIRTY, /* current uuids and flags not yet on disk */ 502 USE_DEGR_WFC_T, /* degr-wfc-timeout instead of wfc-timeout. */ 503 CL_ST_CHG_SUCCESS, 504 CL_ST_CHG_FAIL, 505 CRASHED_PRIMARY, /* This node was a crashed primary. 506 * Gets cleared when the state.conn 507 * goes into C_CONNECTED state. */ 508 CONSIDER_RESYNC, 509 510 MD_NO_FUA, /* Users wants us to not use FUA/FLUSH on meta data dev */ 511 512 BITMAP_IO, /* suspend application io; 513 once no more io in flight, start bitmap io */ 514 BITMAP_IO_QUEUED, /* Started bitmap IO */ 515 WAS_IO_ERROR, /* Local disk failed, returned IO error */ 516 WAS_READ_ERROR, /* Local disk READ failed (set additionally to the above) */ 517 FORCE_DETACH, /* Force-detach from local disk, aborting any pending local IO */ 518 RESYNC_AFTER_NEG, /* Resync after online grow after the attach&negotiate finished. */ 519 RESIZE_PENDING, /* Size change detected locally, waiting for the response from 520 * the peer, if it changed there as well. */ 521 NEW_CUR_UUID, /* Create new current UUID when thawing IO */ 522 AL_SUSPENDED, /* Activity logging is currently suspended. */ 523 AHEAD_TO_SYNC_SOURCE, /* Ahead -> SyncSource queued */ 524 B_RS_H_DONE, /* Before resync handler done (already executed) */ 525 DISCARD_MY_DATA, /* discard_my_data flag per volume */ 526 READ_BALANCE_RR, 527 528 FLUSH_PENDING, /* if set, device->flush_jif is when we submitted that flush 529 * from drbd_flush_after_epoch() */ 530 531 /* cleared only after backing device related structures have been destroyed. */ 532 GOING_DISKLESS, /* Disk is being detached, because of io-error, or admin request. */ 533 534 /* to be used in drbd_device_post_work() */ 535 GO_DISKLESS, /* tell worker to schedule cleanup before detach */ 536 DESTROY_DISK, /* tell worker to close backing devices and destroy related structures. */ 537 MD_SYNC, /* tell worker to call drbd_md_sync() */ 538 RS_START, /* tell worker to start resync/OV */ 539 RS_PROGRESS, /* tell worker that resync made significant progress */ 540 RS_DONE, /* tell worker that resync is done */ 541 }; 542 543 struct drbd_bitmap; /* opaque for drbd_device */ 544 545 /* definition of bits in bm_flags to be used in drbd_bm_lock 546 * and drbd_bitmap_io and friends. */ 547 enum bm_flag { 548 /* currently locked for bulk operation */ 549 BM_LOCKED_MASK = 0xf, 550 551 /* in detail, that is: */ 552 BM_DONT_CLEAR = 0x1, 553 BM_DONT_SET = 0x2, 554 BM_DONT_TEST = 0x4, 555 556 /* so we can mark it locked for bulk operation, 557 * and still allow all non-bulk operations */ 558 BM_IS_LOCKED = 0x8, 559 560 /* (test bit, count bit) allowed (common case) */ 561 BM_LOCKED_TEST_ALLOWED = BM_DONT_CLEAR | BM_DONT_SET | BM_IS_LOCKED, 562 563 /* testing bits, as well as setting new bits allowed, but clearing bits 564 * would be unexpected. Used during bitmap receive. Setting new bits 565 * requires sending of "out-of-sync" information, though. */ 566 BM_LOCKED_SET_ALLOWED = BM_DONT_CLEAR | BM_IS_LOCKED, 567 568 /* for drbd_bm_write_copy_pages, everything is allowed, 569 * only concurrent bulk operations are locked out. */ 570 BM_LOCKED_CHANGE_ALLOWED = BM_IS_LOCKED, 571 }; 572 573 struct drbd_work_queue { 574 struct list_head q; 575 spinlock_t q_lock; /* to protect the list. */ 576 wait_queue_head_t q_wait; 577 }; 578 579 struct drbd_socket { 580 struct mutex mutex; 581 struct socket *socket; 582 /* this way we get our 583 * send/receive buffers off the stack */ 584 void *sbuf; 585 void *rbuf; 586 }; 587 588 struct drbd_md { 589 u64 md_offset; /* sector offset to 'super' block */ 590 591 u64 la_size_sect; /* last agreed size, unit sectors */ 592 spinlock_t uuid_lock; 593 u64 uuid[UI_SIZE]; 594 u64 device_uuid; 595 u32 flags; 596 u32 md_size_sect; 597 598 s32 al_offset; /* signed relative sector offset to activity log */ 599 s32 bm_offset; /* signed relative sector offset to bitmap */ 600 601 /* cached value of bdev->disk_conf->meta_dev_idx (see below) */ 602 s32 meta_dev_idx; 603 604 /* see al_tr_number_to_on_disk_sector() */ 605 u32 al_stripes; 606 u32 al_stripe_size_4k; 607 u32 al_size_4k; /* cached product of the above */ 608 }; 609 610 struct drbd_backing_dev { 611 struct block_device *backing_bdev; 612 struct block_device *md_bdev; 613 struct drbd_md md; 614 struct disk_conf *disk_conf; /* RCU, for updates: resource->conf_update */ 615 sector_t known_size; /* last known size of that backing device */ 616 }; 617 618 struct drbd_md_io { 619 struct page *page; 620 unsigned long start_jif; /* last call to drbd_md_get_buffer */ 621 unsigned long submit_jif; /* last _drbd_md_sync_page_io() submit */ 622 const char *current_use; 623 atomic_t in_use; 624 unsigned int done; 625 int error; 626 }; 627 628 struct bm_io_work { 629 struct drbd_work w; 630 char *why; 631 enum bm_flag flags; 632 int (*io_fn)(struct drbd_device *device); 633 void (*done)(struct drbd_device *device, int rv); 634 }; 635 636 struct fifo_buffer { 637 unsigned int head_index; 638 unsigned int size; 639 int total; /* sum of all values */ 640 int values[0]; 641 }; 642 extern struct fifo_buffer *fifo_alloc(int fifo_size); 643 644 /* flag bits per connection */ 645 enum { 646 NET_CONGESTED, /* The data socket is congested */ 647 RESOLVE_CONFLICTS, /* Set on one node, cleared on the peer! */ 648 SEND_PING, 649 GOT_PING_ACK, /* set when we receive a ping_ack packet, ping_wait gets woken */ 650 CONN_WD_ST_CHG_REQ, /* A cluster wide state change on the connection is active */ 651 CONN_WD_ST_CHG_OKAY, 652 CONN_WD_ST_CHG_FAIL, 653 CONN_DRY_RUN, /* Expect disconnect after resync handshake. */ 654 CREATE_BARRIER, /* next P_DATA is preceded by a P_BARRIER */ 655 STATE_SENT, /* Do not change state/UUIDs while this is set */ 656 CALLBACK_PENDING, /* Whether we have a call_usermodehelper(, UMH_WAIT_PROC) 657 * pending, from drbd worker context. 658 * If set, bdi_write_congested() returns true, 659 * so shrink_page_list() would not recurse into, 660 * and potentially deadlock on, this drbd worker. 661 */ 662 DISCONNECT_SENT, 663 664 DEVICE_WORK_PENDING, /* tell worker that some device has pending work */ 665 }; 666 667 enum which_state { NOW, OLD = NOW, NEW }; 668 669 struct drbd_resource { 670 char *name; 671 #ifdef CONFIG_DEBUG_FS 672 struct dentry *debugfs_res; 673 struct dentry *debugfs_res_volumes; 674 struct dentry *debugfs_res_connections; 675 struct dentry *debugfs_res_in_flight_summary; 676 #endif 677 struct kref kref; 678 struct idr devices; /* volume number to device mapping */ 679 struct list_head connections; 680 struct list_head resources; 681 struct res_opts res_opts; 682 struct mutex conf_update; /* mutex for ready-copy-update of net_conf and disk_conf */ 683 struct mutex adm_mutex; /* mutex to serialize administrative requests */ 684 spinlock_t req_lock; 685 686 unsigned susp:1; /* IO suspended by user */ 687 unsigned susp_nod:1; /* IO suspended because no data */ 688 unsigned susp_fen:1; /* IO suspended because fence peer handler runs */ 689 690 enum write_ordering_e write_ordering; 691 692 cpumask_var_t cpu_mask; 693 }; 694 695 struct drbd_thread_timing_details 696 { 697 unsigned long start_jif; 698 void *cb_addr; 699 const char *caller_fn; 700 unsigned int line; 701 unsigned int cb_nr; 702 }; 703 704 struct drbd_connection { 705 struct list_head connections; 706 struct drbd_resource *resource; 707 #ifdef CONFIG_DEBUG_FS 708 struct dentry *debugfs_conn; 709 struct dentry *debugfs_conn_callback_history; 710 struct dentry *debugfs_conn_oldest_requests; 711 #endif 712 struct kref kref; 713 struct idr peer_devices; /* volume number to peer device mapping */ 714 enum drbd_conns cstate; /* Only C_STANDALONE to C_WF_REPORT_PARAMS */ 715 struct mutex cstate_mutex; /* Protects graceful disconnects */ 716 unsigned int connect_cnt; /* Inc each time a connection is established */ 717 718 unsigned long flags; 719 struct net_conf *net_conf; /* content protected by rcu */ 720 wait_queue_head_t ping_wait; /* Woken upon reception of a ping, and a state change */ 721 722 struct sockaddr_storage my_addr; 723 int my_addr_len; 724 struct sockaddr_storage peer_addr; 725 int peer_addr_len; 726 727 struct drbd_socket data; /* data/barrier/cstate/parameter packets */ 728 struct drbd_socket meta; /* ping/ack (metadata) packets */ 729 int agreed_pro_version; /* actually used protocol version */ 730 u32 agreed_features; 731 unsigned long last_received; /* in jiffies, either socket */ 732 unsigned int ko_count; 733 734 struct list_head transfer_log; /* all requests not yet fully processed */ 735 736 struct crypto_shash *cram_hmac_tfm; 737 struct crypto_ahash *integrity_tfm; /* checksums we compute, updates protected by connection->data->mutex */ 738 struct crypto_ahash *peer_integrity_tfm; /* checksums we verify, only accessed from receiver thread */ 739 struct crypto_ahash *csums_tfm; 740 struct crypto_ahash *verify_tfm; 741 void *int_dig_in; 742 void *int_dig_vv; 743 744 /* receiver side */ 745 struct drbd_epoch *current_epoch; 746 spinlock_t epoch_lock; 747 unsigned int epochs; 748 atomic_t current_tle_nr; /* transfer log epoch number */ 749 unsigned current_tle_writes; /* writes seen within this tl epoch */ 750 751 unsigned long last_reconnect_jif; 752 struct drbd_thread receiver; 753 struct drbd_thread worker; 754 struct drbd_thread ack_receiver; 755 struct workqueue_struct *ack_sender; 756 757 /* cached pointers, 758 * so we can look up the oldest pending requests more quickly. 759 * protected by resource->req_lock */ 760 struct drbd_request *req_next; /* DRBD 9: todo.req_next */ 761 struct drbd_request *req_ack_pending; 762 struct drbd_request *req_not_net_done; 763 764 /* sender side */ 765 struct drbd_work_queue sender_work; 766 767 #define DRBD_THREAD_DETAILS_HIST 16 768 unsigned int w_cb_nr; /* keeps counting up */ 769 unsigned int r_cb_nr; /* keeps counting up */ 770 struct drbd_thread_timing_details w_timing_details[DRBD_THREAD_DETAILS_HIST]; 771 struct drbd_thread_timing_details r_timing_details[DRBD_THREAD_DETAILS_HIST]; 772 773 struct { 774 unsigned long last_sent_barrier_jif; 775 776 /* 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 }; 789 790 static inline bool has_net_conf(struct drbd_connection *connection) 791 { 792 bool has_net_conf; 793 794 rcu_read_lock(); 795 has_net_conf = rcu_dereference(connection->net_conf); 796 rcu_read_unlock(); 797 798 return has_net_conf; 799 } 800 801 void __update_timing_details( 802 struct drbd_thread_timing_details *tdp, 803 unsigned int *cb_nr, 804 void *cb, 805 const char *fn, const unsigned int line); 806 807 #define update_worker_timing_details(c, cb) \ 808 __update_timing_details(c->w_timing_details, &c->w_cb_nr, cb, __func__ , __LINE__ ) 809 #define update_receiver_timing_details(c, cb) \ 810 __update_timing_details(c->r_timing_details, &c->r_cb_nr, cb, __func__ , __LINE__ ) 811 812 struct submit_worker { 813 struct workqueue_struct *wq; 814 struct work_struct worker; 815 816 /* protected by ..->resource->req_lock */ 817 struct list_head writes; 818 }; 819 820 struct drbd_peer_device { 821 struct list_head peer_devices; 822 struct drbd_device *device; 823 struct drbd_connection *connection; 824 struct work_struct send_acks_work; 825 #ifdef CONFIG_DEBUG_FS 826 struct dentry *debugfs_peer_dev; 827 #endif 828 }; 829 830 struct drbd_device { 831 struct drbd_resource *resource; 832 struct list_head peer_devices; 833 struct list_head pending_bitmap_io; 834 835 unsigned long flush_jif; 836 #ifdef CONFIG_DEBUG_FS 837 struct dentry *debugfs_minor; 838 struct dentry *debugfs_vol; 839 struct dentry *debugfs_vol_oldest_requests; 840 struct dentry *debugfs_vol_act_log_extents; 841 struct dentry *debugfs_vol_resync_extents; 842 struct dentry *debugfs_vol_data_gen_id; 843 struct dentry *debugfs_vol_ed_gen_id; 844 #endif 845 846 unsigned int vnr; /* volume number within the connection */ 847 unsigned int minor; /* device minor number */ 848 849 struct kref kref; 850 851 /* things that are stored as / read from meta data on disk */ 852 unsigned long flags; 853 854 /* configured by drbdsetup */ 855 struct drbd_backing_dev *ldev __protected_by(local); 856 857 sector_t p_size; /* partner's disk size */ 858 struct request_queue *rq_queue; 859 struct block_device *this_bdev; 860 struct gendisk *vdisk; 861 862 unsigned long last_reattach_jif; 863 struct drbd_work resync_work; 864 struct drbd_work unplug_work; 865 struct timer_list resync_timer; 866 struct timer_list md_sync_timer; 867 struct timer_list start_resync_timer; 868 struct timer_list request_timer; 869 870 /* Used after attach while negotiating new disk state. */ 871 union drbd_state new_state_tmp; 872 873 union drbd_dev_state state; 874 wait_queue_head_t misc_wait; 875 wait_queue_head_t state_wait; /* upon each state change. */ 876 unsigned int send_cnt; 877 unsigned int recv_cnt; 878 unsigned int read_cnt; 879 unsigned int writ_cnt; 880 unsigned int al_writ_cnt; 881 unsigned int bm_writ_cnt; 882 atomic_t ap_bio_cnt; /* Requests we need to complete */ 883 atomic_t ap_actlog_cnt; /* Requests waiting for activity log */ 884 atomic_t ap_pending_cnt; /* AP data packets on the wire, ack expected */ 885 atomic_t rs_pending_cnt; /* RS request/data packets on the wire */ 886 atomic_t unacked_cnt; /* Need to send replies for */ 887 atomic_t local_cnt; /* Waiting for local completion */ 888 atomic_t suspend_cnt; 889 890 /* Interval tree of pending local requests */ 891 struct rb_root read_requests; 892 struct rb_root write_requests; 893 894 /* for statistics and timeouts */ 895 /* [0] read, [1] write */ 896 struct list_head pending_master_completion[2]; 897 struct list_head pending_completion[2]; 898 899 /* use checksums for *this* resync */ 900 bool use_csums; 901 /* blocks to resync in this run [unit BM_BLOCK_SIZE] */ 902 unsigned long rs_total; 903 /* number of resync blocks that failed in this run */ 904 unsigned long rs_failed; 905 /* Syncer's start time [unit jiffies] */ 906 unsigned long rs_start; 907 /* cumulated time in PausedSyncX state [unit jiffies] */ 908 unsigned long rs_paused; 909 /* skipped because csum was equal [unit BM_BLOCK_SIZE] */ 910 unsigned long rs_same_csum; 911 #define DRBD_SYNC_MARKS 8 912 #define DRBD_SYNC_MARK_STEP (3*HZ) 913 /* block not up-to-date at mark [unit BM_BLOCK_SIZE] */ 914 unsigned long rs_mark_left[DRBD_SYNC_MARKS]; 915 /* marks's time [unit jiffies] */ 916 unsigned long rs_mark_time[DRBD_SYNC_MARKS]; 917 /* current index into rs_mark_{left,time} */ 918 int rs_last_mark; 919 unsigned long rs_last_bcast; /* [unit jiffies] */ 920 921 /* where does the admin want us to start? (sector) */ 922 sector_t ov_start_sector; 923 sector_t ov_stop_sector; 924 /* where are we now? (sector) */ 925 sector_t ov_position; 926 /* Start sector of out of sync range (to merge printk reporting). */ 927 sector_t ov_last_oos_start; 928 /* size of out-of-sync range in sectors. */ 929 sector_t ov_last_oos_size; 930 unsigned long ov_left; /* in bits */ 931 932 struct drbd_bitmap *bitmap; 933 unsigned long bm_resync_fo; /* bit offset for drbd_bm_find_next */ 934 935 /* Used to track operations of resync... */ 936 struct lru_cache *resync; 937 /* Number of locked elements in resync LRU */ 938 unsigned int resync_locked; 939 /* resync extent number waiting for application requests */ 940 unsigned int resync_wenr; 941 942 int open_cnt; 943 u64 *p_uuid; 944 945 struct list_head active_ee; /* IO in progress (P_DATA gets written to disk) */ 946 struct list_head sync_ee; /* IO in progress (P_RS_DATA_REPLY gets written to disk) */ 947 struct list_head done_ee; /* need to send P_WRITE_ACK */ 948 struct list_head read_ee; /* [RS]P_DATA_REQUEST being read */ 949 struct list_head net_ee; /* zero-copy network send in progress */ 950 951 int next_barrier_nr; 952 struct list_head resync_reads; 953 atomic_t pp_in_use; /* allocated from page pool */ 954 atomic_t pp_in_use_by_net; /* sendpage()d, still referenced by tcp */ 955 wait_queue_head_t ee_wait; 956 struct drbd_md_io md_io; 957 spinlock_t al_lock; 958 wait_queue_head_t al_wait; 959 struct lru_cache *act_log; /* activity log */ 960 unsigned int al_tr_number; 961 int al_tr_cycle; 962 wait_queue_head_t seq_wait; 963 atomic_t packet_seq; 964 unsigned int peer_seq; 965 spinlock_t peer_seq_lock; 966 unsigned long comm_bm_set; /* communicated number of set bits. */ 967 struct bm_io_work bm_io_work; 968 u64 ed_uuid; /* UUID of the exposed data */ 969 struct mutex own_state_mutex; 970 struct mutex *state_mutex; /* either own_state_mutex or first_peer_device(device)->connection->cstate_mutex */ 971 char congestion_reason; /* Why we where congested... */ 972 atomic_t rs_sect_in; /* for incoming resync data rate, SyncTarget */ 973 atomic_t rs_sect_ev; /* for submitted resync data rate, both */ 974 int rs_last_sect_ev; /* counter to compare with */ 975 int rs_last_events; /* counter of read or write "events" (unit sectors) 976 * on the lower level device when we last looked. */ 977 int c_sync_rate; /* current resync rate after syncer throttle magic */ 978 struct fifo_buffer *rs_plan_s; /* correction values of resync planer (RCU, connection->conn_update) */ 979 int rs_in_flight; /* resync sectors in flight (to proxy, in proxy and from proxy) */ 980 atomic_t ap_in_flight; /* App sectors in flight (waiting for ack) */ 981 unsigned int peer_max_bio_size; 982 unsigned int local_max_bio_size; 983 984 /* any requests that would block in drbd_make_request() 985 * are deferred to this single-threaded work queue */ 986 struct submit_worker submit; 987 }; 988 989 struct drbd_bm_aio_ctx { 990 struct drbd_device *device; 991 struct list_head list; /* on device->pending_bitmap_io */; 992 unsigned long start_jif; 993 atomic_t in_flight; 994 unsigned int done; 995 unsigned flags; 996 #define BM_AIO_COPY_PAGES 1 997 #define BM_AIO_WRITE_HINTED 2 998 #define BM_AIO_WRITE_ALL_PAGES 4 999 #define BM_AIO_READ 8 1000 int error; 1001 struct kref kref; 1002 }; 1003 1004 struct drbd_config_context { 1005 /* assigned from drbd_genlmsghdr */ 1006 unsigned int minor; 1007 /* assigned from request attributes, if present */ 1008 unsigned int volume; 1009 #define VOLUME_UNSPECIFIED (-1U) 1010 /* pointer into the request skb, 1011 * limited lifetime! */ 1012 char *resource_name; 1013 struct nlattr *my_addr; 1014 struct nlattr *peer_addr; 1015 1016 /* reply buffer */ 1017 struct sk_buff *reply_skb; 1018 /* pointer into reply buffer */ 1019 struct drbd_genlmsghdr *reply_dh; 1020 /* resolved from attributes, if possible */ 1021 struct drbd_device *device; 1022 struct drbd_resource *resource; 1023 struct drbd_connection *connection; 1024 }; 1025 1026 static inline struct drbd_device *minor_to_device(unsigned int minor) 1027 { 1028 return (struct drbd_device *)idr_find(&drbd_devices, minor); 1029 } 1030 1031 static inline struct drbd_peer_device *first_peer_device(struct drbd_device *device) 1032 { 1033 return list_first_entry_or_null(&device->peer_devices, struct drbd_peer_device, peer_devices); 1034 } 1035 1036 static inline struct drbd_peer_device * 1037 conn_peer_device(struct drbd_connection *connection, int volume_number) 1038 { 1039 return idr_find(&connection->peer_devices, volume_number); 1040 } 1041 1042 #define for_each_resource(resource, _resources) \ 1043 list_for_each_entry(resource, _resources, resources) 1044 1045 #define for_each_resource_rcu(resource, _resources) \ 1046 list_for_each_entry_rcu(resource, _resources, resources) 1047 1048 #define for_each_resource_safe(resource, tmp, _resources) \ 1049 list_for_each_entry_safe(resource, tmp, _resources, resources) 1050 1051 #define for_each_connection(connection, resource) \ 1052 list_for_each_entry(connection, &resource->connections, connections) 1053 1054 #define for_each_connection_rcu(connection, resource) \ 1055 list_for_each_entry_rcu(connection, &resource->connections, connections) 1056 1057 #define for_each_connection_safe(connection, tmp, resource) \ 1058 list_for_each_entry_safe(connection, tmp, &resource->connections, connections) 1059 1060 #define for_each_peer_device(peer_device, device) \ 1061 list_for_each_entry(peer_device, &device->peer_devices, peer_devices) 1062 1063 #define for_each_peer_device_rcu(peer_device, device) \ 1064 list_for_each_entry_rcu(peer_device, &device->peer_devices, peer_devices) 1065 1066 #define for_each_peer_device_safe(peer_device, tmp, device) \ 1067 list_for_each_entry_safe(peer_device, tmp, &device->peer_devices, peer_devices) 1068 1069 static inline unsigned int device_to_minor(struct drbd_device *device) 1070 { 1071 return device->minor; 1072 } 1073 1074 /* 1075 * function declarations 1076 *************************/ 1077 1078 /* drbd_main.c */ 1079 1080 enum dds_flags { 1081 DDSF_FORCED = 1, 1082 DDSF_NO_RESYNC = 2, /* Do not run a resync for the new space */ 1083 }; 1084 1085 extern void drbd_init_set_defaults(struct drbd_device *device); 1086 extern int drbd_thread_start(struct drbd_thread *thi); 1087 extern void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait); 1088 #ifdef CONFIG_SMP 1089 extern void drbd_thread_current_set_cpu(struct drbd_thread *thi); 1090 #else 1091 #define drbd_thread_current_set_cpu(A) ({}) 1092 #endif 1093 extern void tl_release(struct drbd_connection *, unsigned int barrier_nr, 1094 unsigned int set_size); 1095 extern void tl_clear(struct drbd_connection *); 1096 extern void drbd_free_sock(struct drbd_connection *connection); 1097 extern int drbd_send(struct drbd_connection *connection, struct socket *sock, 1098 void *buf, size_t size, unsigned msg_flags); 1099 extern int drbd_send_all(struct drbd_connection *, struct socket *, void *, size_t, 1100 unsigned); 1101 1102 extern int __drbd_send_protocol(struct drbd_connection *connection, enum drbd_packet cmd); 1103 extern int drbd_send_protocol(struct drbd_connection *connection); 1104 extern int drbd_send_uuids(struct drbd_peer_device *); 1105 extern int drbd_send_uuids_skip_initial_sync(struct drbd_peer_device *); 1106 extern void drbd_gen_and_send_sync_uuid(struct drbd_peer_device *); 1107 extern int drbd_send_sizes(struct drbd_peer_device *, int trigger_reply, enum dds_flags flags); 1108 extern int drbd_send_state(struct drbd_peer_device *, union drbd_state s); 1109 extern int drbd_send_current_state(struct drbd_peer_device *); 1110 extern int drbd_send_sync_param(struct drbd_peer_device *); 1111 extern void drbd_send_b_ack(struct drbd_connection *connection, u32 barrier_nr, 1112 u32 set_size); 1113 extern int drbd_send_ack(struct drbd_peer_device *, enum drbd_packet, 1114 struct drbd_peer_request *); 1115 extern void drbd_send_ack_rp(struct drbd_peer_device *, enum drbd_packet, 1116 struct p_block_req *rp); 1117 extern void drbd_send_ack_dp(struct drbd_peer_device *, enum drbd_packet, 1118 struct p_data *dp, int data_size); 1119 extern int drbd_send_ack_ex(struct drbd_peer_device *, enum drbd_packet, 1120 sector_t sector, int blksize, u64 block_id); 1121 extern int drbd_send_out_of_sync(struct drbd_peer_device *, struct drbd_request *); 1122 extern int drbd_send_block(struct drbd_peer_device *, enum drbd_packet, 1123 struct drbd_peer_request *); 1124 extern int drbd_send_dblock(struct drbd_peer_device *, struct drbd_request *req); 1125 extern int drbd_send_drequest(struct drbd_peer_device *, int cmd, 1126 sector_t sector, int size, u64 block_id); 1127 extern int drbd_send_drequest_csum(struct drbd_peer_device *, sector_t sector, 1128 int size, void *digest, int digest_size, 1129 enum drbd_packet cmd); 1130 extern int drbd_send_ov_request(struct drbd_peer_device *, sector_t sector, int size); 1131 1132 extern int drbd_send_bitmap(struct drbd_device *device); 1133 extern void drbd_send_sr_reply(struct drbd_peer_device *, enum drbd_state_rv retcode); 1134 extern void conn_send_sr_reply(struct drbd_connection *connection, enum drbd_state_rv retcode); 1135 extern int drbd_send_rs_deallocated(struct drbd_peer_device *, struct drbd_peer_request *); 1136 extern void drbd_backing_dev_free(struct drbd_device *device, struct drbd_backing_dev *ldev); 1137 extern void drbd_device_cleanup(struct drbd_device *device); 1138 void drbd_print_uuids(struct drbd_device *device, const char *text); 1139 1140 extern void conn_md_sync(struct drbd_connection *connection); 1141 extern void drbd_md_write(struct drbd_device *device, void *buffer); 1142 extern void drbd_md_sync(struct drbd_device *device); 1143 extern int drbd_md_read(struct drbd_device *device, struct drbd_backing_dev *bdev); 1144 extern void drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local); 1145 extern void _drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local); 1146 extern void drbd_uuid_new_current(struct drbd_device *device) __must_hold(local); 1147 extern void drbd_uuid_set_bm(struct drbd_device *device, u64 val) __must_hold(local); 1148 extern void drbd_uuid_move_history(struct drbd_device *device) __must_hold(local); 1149 extern void __drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local); 1150 extern void drbd_md_set_flag(struct drbd_device *device, int flags) __must_hold(local); 1151 extern void drbd_md_clear_flag(struct drbd_device *device, int flags)__must_hold(local); 1152 extern int drbd_md_test_flag(struct drbd_backing_dev *, int); 1153 extern void drbd_md_mark_dirty(struct drbd_device *device); 1154 extern void drbd_queue_bitmap_io(struct drbd_device *device, 1155 int (*io_fn)(struct drbd_device *), 1156 void (*done)(struct drbd_device *, int), 1157 char *why, enum bm_flag flags); 1158 extern int drbd_bitmap_io(struct drbd_device *device, 1159 int (*io_fn)(struct drbd_device *), 1160 char *why, enum bm_flag flags); 1161 extern int drbd_bitmap_io_from_worker(struct drbd_device *device, 1162 int (*io_fn)(struct drbd_device *), 1163 char *why, enum bm_flag flags); 1164 extern int drbd_bmio_set_n_write(struct drbd_device *device) __must_hold(local); 1165 extern int drbd_bmio_clear_n_write(struct drbd_device *device) __must_hold(local); 1166 1167 /* Meta data layout 1168 * 1169 * We currently have two possible layouts. 1170 * Offsets in (512 byte) sectors. 1171 * external: 1172 * |----------- md_size_sect ------------------| 1173 * [ 4k superblock ][ activity log ][ Bitmap ] 1174 * | al_offset == 8 | 1175 * | bm_offset = al_offset + X | 1176 * ==> bitmap sectors = md_size_sect - bm_offset 1177 * 1178 * Variants: 1179 * old, indexed fixed size meta data: 1180 * 1181 * internal: 1182 * |----------- md_size_sect ------------------| 1183 * [data.....][ Bitmap ][ activity log ][ 4k superblock ][padding*] 1184 * | al_offset < 0 | 1185 * | bm_offset = al_offset - Y | 1186 * ==> bitmap sectors = Y = al_offset - bm_offset 1187 * 1188 * [padding*] are zero or up to 7 unused 512 Byte sectors to the 1189 * end of the device, so that the [4k superblock] will be 4k aligned. 1190 * 1191 * The activity log consists of 4k transaction blocks, 1192 * which are written in a ring-buffer, or striped ring-buffer like fashion, 1193 * which are writtensize used to be fixed 32kB, 1194 * but is about to become configurable. 1195 */ 1196 1197 /* Our old fixed size meta data layout 1198 * allows up to about 3.8TB, so if you want more, 1199 * you need to use the "flexible" meta data format. */ 1200 #define MD_128MB_SECT (128LLU << 11) /* 128 MB, unit sectors */ 1201 #define MD_4kB_SECT 8 1202 #define MD_32kB_SECT 64 1203 1204 /* One activity log extent represents 4M of storage */ 1205 #define AL_EXTENT_SHIFT 22 1206 #define AL_EXTENT_SIZE (1<<AL_EXTENT_SHIFT) 1207 1208 /* We could make these currently hardcoded constants configurable 1209 * variables at create-md time (or even re-configurable at runtime?). 1210 * Which will require some more changes to the DRBD "super block" 1211 * and attach code. 1212 * 1213 * updates per transaction: 1214 * This many changes to the active set can be logged with one transaction. 1215 * This number is arbitrary. 1216 * context per transaction: 1217 * This many context extent numbers are logged with each transaction. 1218 * This number is resulting from the transaction block size (4k), the layout 1219 * of the transaction header, and the number of updates per transaction. 1220 * See drbd_actlog.c:struct al_transaction_on_disk 1221 * */ 1222 #define AL_UPDATES_PER_TRANSACTION 64 // arbitrary 1223 #define AL_CONTEXT_PER_TRANSACTION 919 // (4096 - 36 - 6*64)/4 1224 1225 #if BITS_PER_LONG == 32 1226 #define LN2_BPL 5 1227 #define cpu_to_lel(A) cpu_to_le32(A) 1228 #define lel_to_cpu(A) le32_to_cpu(A) 1229 #elif BITS_PER_LONG == 64 1230 #define LN2_BPL 6 1231 #define cpu_to_lel(A) cpu_to_le64(A) 1232 #define lel_to_cpu(A) le64_to_cpu(A) 1233 #else 1234 #error "LN2 of BITS_PER_LONG unknown!" 1235 #endif 1236 1237 /* resync bitmap */ 1238 /* 16MB sized 'bitmap extent' to track syncer usage */ 1239 struct bm_extent { 1240 int rs_left; /* number of bits set (out of sync) in this extent. */ 1241 int rs_failed; /* number of failed resync requests in this extent. */ 1242 unsigned long flags; 1243 struct lc_element lce; 1244 }; 1245 1246 #define BME_NO_WRITES 0 /* bm_extent.flags: no more requests on this one! */ 1247 #define BME_LOCKED 1 /* bm_extent.flags: syncer active on this one. */ 1248 #define BME_PRIORITY 2 /* finish resync IO on this extent ASAP! App IO waiting! */ 1249 1250 /* drbd_bitmap.c */ 1251 /* 1252 * We need to store one bit for a block. 1253 * Example: 1GB disk @ 4096 byte blocks ==> we need 32 KB bitmap. 1254 * Bit 0 ==> local node thinks this block is binary identical on both nodes 1255 * Bit 1 ==> local node thinks this block needs to be synced. 1256 */ 1257 1258 #define SLEEP_TIME (HZ/10) 1259 1260 /* We do bitmap IO in units of 4k blocks. 1261 * We also still have a hardcoded 4k per bit relation. */ 1262 #define BM_BLOCK_SHIFT 12 /* 4k per bit */ 1263 #define BM_BLOCK_SIZE (1<<BM_BLOCK_SHIFT) 1264 /* mostly arbitrarily set the represented size of one bitmap extent, 1265 * aka resync extent, to 16 MiB (which is also 512 Byte worth of bitmap 1266 * at 4k per bit resolution) */ 1267 #define BM_EXT_SHIFT 24 /* 16 MiB per resync extent */ 1268 #define BM_EXT_SIZE (1<<BM_EXT_SHIFT) 1269 1270 #if (BM_EXT_SHIFT != 24) || (BM_BLOCK_SHIFT != 12) 1271 #error "HAVE YOU FIXED drbdmeta AS WELL??" 1272 #endif 1273 1274 /* thus many _storage_ sectors are described by one bit */ 1275 #define BM_SECT_TO_BIT(x) ((x)>>(BM_BLOCK_SHIFT-9)) 1276 #define BM_BIT_TO_SECT(x) ((sector_t)(x)<<(BM_BLOCK_SHIFT-9)) 1277 #define BM_SECT_PER_BIT BM_BIT_TO_SECT(1) 1278 1279 /* bit to represented kilo byte conversion */ 1280 #define Bit2KB(bits) ((bits)<<(BM_BLOCK_SHIFT-10)) 1281 1282 /* in which _bitmap_ extent (resp. sector) the bit for a certain 1283 * _storage_ sector is located in */ 1284 #define BM_SECT_TO_EXT(x) ((x)>>(BM_EXT_SHIFT-9)) 1285 #define BM_BIT_TO_EXT(x) ((x) >> (BM_EXT_SHIFT - BM_BLOCK_SHIFT)) 1286 1287 /* first storage sector a bitmap extent corresponds to */ 1288 #define BM_EXT_TO_SECT(x) ((sector_t)(x) << (BM_EXT_SHIFT-9)) 1289 /* how much _storage_ sectors we have per bitmap extent */ 1290 #define BM_SECT_PER_EXT BM_EXT_TO_SECT(1) 1291 /* how many bits are covered by one bitmap extent (resync extent) */ 1292 #define BM_BITS_PER_EXT (1UL << (BM_EXT_SHIFT - BM_BLOCK_SHIFT)) 1293 1294 #define BM_BLOCKS_PER_BM_EXT_MASK (BM_BITS_PER_EXT - 1) 1295 1296 1297 /* in one sector of the bitmap, we have this many activity_log extents. */ 1298 #define AL_EXT_PER_BM_SECT (1 << (BM_EXT_SHIFT - AL_EXTENT_SHIFT)) 1299 1300 /* the extent in "PER_EXTENT" below is an activity log extent 1301 * we need that many (long words/bytes) to store the bitmap 1302 * of one AL_EXTENT_SIZE chunk of storage. 1303 * we can store the bitmap for that many AL_EXTENTS within 1304 * one sector of the _on_disk_ bitmap: 1305 * bit 0 bit 37 bit 38 bit (512*8)-1 1306 * ...|........|........|.. // ..|........| 1307 * sect. 0 `296 `304 ^(512*8*8)-1 1308 * 1309 #define BM_WORDS_PER_EXT ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / BITS_PER_LONG ) 1310 #define BM_BYTES_PER_EXT ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / 8 ) // 128 1311 #define BM_EXT_PER_SECT ( 512 / BM_BYTES_PER_EXTENT ) // 4 1312 */ 1313 1314 #define DRBD_MAX_SECTORS_32 (0xffffffffLU) 1315 /* we have a certain meta data variant that has a fixed on-disk size of 128 1316 * MiB, of which 4k are our "superblock", and 32k are the fixed size activity 1317 * log, leaving this many sectors for the bitmap. 1318 */ 1319 1320 #define DRBD_MAX_SECTORS_FIXED_BM \ 1321 ((MD_128MB_SECT - MD_32kB_SECT - MD_4kB_SECT) * (1LL<<(BM_EXT_SHIFT-9))) 1322 #if !defined(CONFIG_LBDAF) && BITS_PER_LONG == 32 1323 #define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_32 1324 #define DRBD_MAX_SECTORS_FLEX DRBD_MAX_SECTORS_32 1325 #else 1326 #define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_FIXED_BM 1327 /* 16 TB in units of sectors */ 1328 #if BITS_PER_LONG == 32 1329 /* adjust by one page worth of bitmap, 1330 * so we won't wrap around in drbd_bm_find_next_bit. 1331 * you should use 64bit OS for that much storage, anyways. */ 1332 #define DRBD_MAX_SECTORS_FLEX BM_BIT_TO_SECT(0xffff7fff) 1333 #else 1334 /* we allow up to 1 PiB now on 64bit architecture with "flexible" meta data */ 1335 #define DRBD_MAX_SECTORS_FLEX (1UL << 51) 1336 /* corresponds to (1UL << 38) bits right now. */ 1337 #endif 1338 #endif 1339 1340 /* Estimate max bio size as 256 * PAGE_SIZE, 1341 * so for typical PAGE_SIZE of 4k, that is (1<<20) Byte. 1342 * Since we may live in a mixed-platform cluster, 1343 * we limit us to a platform agnostic constant here for now. 1344 * A followup commit may allow even bigger BIO sizes, 1345 * once we thought that through. */ 1346 #define DRBD_MAX_BIO_SIZE (1U << 20) 1347 #if DRBD_MAX_BIO_SIZE > (BIO_MAX_PAGES << PAGE_SHIFT) 1348 #error Architecture not supported: DRBD_MAX_BIO_SIZE > BIO_MAX_SIZE 1349 #endif 1350 #define DRBD_MAX_BIO_SIZE_SAFE (1U << 12) /* Works always = 4k */ 1351 1352 #define DRBD_MAX_SIZE_H80_PACKET (1U << 15) /* Header 80 only allows packets up to 32KiB data */ 1353 #define DRBD_MAX_BIO_SIZE_P95 (1U << 17) /* Protocol 95 to 99 allows bios up to 128KiB */ 1354 1355 /* For now, don't allow more than half of what we can "activate" in one 1356 * activity log transaction to be discarded in one go. We may need to rework 1357 * drbd_al_begin_io() to allow for even larger discard ranges */ 1358 #define DRBD_MAX_BATCH_BIO_SIZE (AL_UPDATES_PER_TRANSACTION/2*AL_EXTENT_SIZE) 1359 #define DRBD_MAX_BBIO_SECTORS (DRBD_MAX_BATCH_BIO_SIZE >> 9) 1360 1361 extern int drbd_bm_init(struct drbd_device *device); 1362 extern int drbd_bm_resize(struct drbd_device *device, sector_t sectors, int set_new_bits); 1363 extern void drbd_bm_cleanup(struct drbd_device *device); 1364 extern void drbd_bm_set_all(struct drbd_device *device); 1365 extern void drbd_bm_clear_all(struct drbd_device *device); 1366 /* set/clear/test only a few bits at a time */ 1367 extern int drbd_bm_set_bits( 1368 struct drbd_device *device, unsigned long s, unsigned long e); 1369 extern int drbd_bm_clear_bits( 1370 struct drbd_device *device, unsigned long s, unsigned long e); 1371 extern int drbd_bm_count_bits( 1372 struct drbd_device *device, const unsigned long s, const unsigned long e); 1373 /* bm_set_bits variant for use while holding drbd_bm_lock, 1374 * may process the whole bitmap in one go */ 1375 extern void _drbd_bm_set_bits(struct drbd_device *device, 1376 const unsigned long s, const unsigned long e); 1377 extern int drbd_bm_test_bit(struct drbd_device *device, unsigned long bitnr); 1378 extern int drbd_bm_e_weight(struct drbd_device *device, unsigned long enr); 1379 extern int drbd_bm_read(struct drbd_device *device) __must_hold(local); 1380 extern void drbd_bm_mark_for_writeout(struct drbd_device *device, int page_nr); 1381 extern int drbd_bm_write(struct drbd_device *device) __must_hold(local); 1382 extern void drbd_bm_reset_al_hints(struct drbd_device *device) __must_hold(local); 1383 extern int drbd_bm_write_hinted(struct drbd_device *device) __must_hold(local); 1384 extern int drbd_bm_write_lazy(struct drbd_device *device, unsigned upper_idx) __must_hold(local); 1385 extern int drbd_bm_write_all(struct drbd_device *device) __must_hold(local); 1386 extern int drbd_bm_write_copy_pages(struct drbd_device *device) __must_hold(local); 1387 extern size_t drbd_bm_words(struct drbd_device *device); 1388 extern unsigned long drbd_bm_bits(struct drbd_device *device); 1389 extern sector_t drbd_bm_capacity(struct drbd_device *device); 1390 1391 #define DRBD_END_OF_BITMAP (~(unsigned long)0) 1392 extern unsigned long drbd_bm_find_next(struct drbd_device *device, unsigned long bm_fo); 1393 /* bm_find_next variants for use while you hold drbd_bm_lock() */ 1394 extern unsigned long _drbd_bm_find_next(struct drbd_device *device, unsigned long bm_fo); 1395 extern unsigned long _drbd_bm_find_next_zero(struct drbd_device *device, unsigned long bm_fo); 1396 extern unsigned long _drbd_bm_total_weight(struct drbd_device *device); 1397 extern unsigned long drbd_bm_total_weight(struct drbd_device *device); 1398 /* for receive_bitmap */ 1399 extern void drbd_bm_merge_lel(struct drbd_device *device, size_t offset, 1400 size_t number, unsigned long *buffer); 1401 /* for _drbd_send_bitmap */ 1402 extern void drbd_bm_get_lel(struct drbd_device *device, size_t offset, 1403 size_t number, unsigned long *buffer); 1404 1405 extern void drbd_bm_lock(struct drbd_device *device, char *why, enum bm_flag flags); 1406 extern void drbd_bm_unlock(struct drbd_device *device); 1407 /* drbd_main.c */ 1408 1409 extern struct kmem_cache *drbd_request_cache; 1410 extern struct kmem_cache *drbd_ee_cache; /* peer requests */ 1411 extern struct kmem_cache *drbd_bm_ext_cache; /* bitmap extents */ 1412 extern struct kmem_cache *drbd_al_ext_cache; /* activity log extents */ 1413 extern mempool_t *drbd_request_mempool; 1414 extern mempool_t *drbd_ee_mempool; 1415 1416 /* drbd's page pool, used to buffer data received from the peer, 1417 * or data requested by the peer. 1418 * 1419 * This does not have an emergency reserve. 1420 * 1421 * When allocating from this pool, it first takes pages from the pool. 1422 * Only if the pool is depleted will try to allocate from the system. 1423 * 1424 * The assumption is that pages taken from this pool will be processed, 1425 * and given back, "quickly", and then can be recycled, so we can avoid 1426 * frequent calls to alloc_page(), and still will be able to make progress even 1427 * under memory pressure. 1428 */ 1429 extern struct page *drbd_pp_pool; 1430 extern spinlock_t drbd_pp_lock; 1431 extern int drbd_pp_vacant; 1432 extern wait_queue_head_t drbd_pp_wait; 1433 1434 /* We also need a standard (emergency-reserve backed) page pool 1435 * for meta data IO (activity log, bitmap). 1436 * We can keep it global, as long as it is used as "N pages at a time". 1437 * 128 should be plenty, currently we probably can get away with as few as 1. 1438 */ 1439 #define DRBD_MIN_POOL_PAGES 128 1440 extern mempool_t *drbd_md_io_page_pool; 1441 1442 /* We also need to make sure we get a bio 1443 * when we need it for housekeeping purposes */ 1444 extern struct bio_set *drbd_md_io_bio_set; 1445 /* to allocate from that set */ 1446 extern struct bio *bio_alloc_drbd(gfp_t gfp_mask); 1447 1448 extern struct mutex resources_mutex; 1449 1450 extern int conn_lowest_minor(struct drbd_connection *connection); 1451 extern enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsigned int minor); 1452 extern void drbd_destroy_device(struct kref *kref); 1453 extern void drbd_delete_device(struct drbd_device *device); 1454 1455 extern struct drbd_resource *drbd_create_resource(const char *name); 1456 extern void drbd_free_resource(struct drbd_resource *resource); 1457 1458 extern int set_resource_options(struct drbd_resource *resource, struct res_opts *res_opts); 1459 extern struct drbd_connection *conn_create(const char *name, struct res_opts *res_opts); 1460 extern void drbd_destroy_connection(struct kref *kref); 1461 extern struct drbd_connection *conn_get_by_addrs(void *my_addr, int my_addr_len, 1462 void *peer_addr, int peer_addr_len); 1463 extern struct drbd_resource *drbd_find_resource(const char *name); 1464 extern void drbd_destroy_resource(struct kref *kref); 1465 extern void conn_free_crypto(struct drbd_connection *connection); 1466 1467 extern int proc_details; 1468 1469 /* drbd_req */ 1470 extern void do_submit(struct work_struct *ws); 1471 extern void __drbd_make_request(struct drbd_device *, struct bio *, unsigned long); 1472 extern blk_qc_t drbd_make_request(struct request_queue *q, struct bio *bio); 1473 extern int drbd_read_remote(struct drbd_device *device, struct drbd_request *req); 1474 extern int is_valid_ar_handle(struct drbd_request *, sector_t); 1475 1476 1477 /* drbd_nl.c */ 1478 1479 extern struct mutex notification_mutex; 1480 1481 extern void drbd_suspend_io(struct drbd_device *device); 1482 extern void drbd_resume_io(struct drbd_device *device); 1483 extern char *ppsize(char *buf, unsigned long long size); 1484 extern sector_t drbd_new_dev_size(struct drbd_device *, struct drbd_backing_dev *, sector_t, int); 1485 enum determine_dev_size { 1486 DS_ERROR_SHRINK = -3, 1487 DS_ERROR_SPACE_MD = -2, 1488 DS_ERROR = -1, 1489 DS_UNCHANGED = 0, 1490 DS_SHRUNK = 1, 1491 DS_GREW = 2, 1492 DS_GREW_FROM_ZERO = 3, 1493 }; 1494 extern enum determine_dev_size 1495 drbd_determine_dev_size(struct drbd_device *, enum dds_flags, struct resize_parms *) __must_hold(local); 1496 extern void resync_after_online_grow(struct drbd_device *); 1497 extern void drbd_reconsider_queue_parameters(struct drbd_device *device, 1498 struct drbd_backing_dev *bdev, struct o_qlim *o); 1499 extern enum drbd_state_rv drbd_set_role(struct drbd_device *device, 1500 enum drbd_role new_role, 1501 int force); 1502 extern bool conn_try_outdate_peer(struct drbd_connection *connection); 1503 extern void conn_try_outdate_peer_async(struct drbd_connection *connection); 1504 extern enum drbd_peer_state conn_khelper(struct drbd_connection *connection, char *cmd); 1505 extern int drbd_khelper(struct drbd_device *device, char *cmd); 1506 1507 /* drbd_worker.c */ 1508 /* bi_end_io handlers */ 1509 extern void drbd_md_endio(struct bio *bio); 1510 extern void drbd_peer_request_endio(struct bio *bio); 1511 extern void drbd_request_endio(struct bio *bio); 1512 extern int drbd_worker(struct drbd_thread *thi); 1513 enum drbd_ret_code drbd_resync_after_valid(struct drbd_device *device, int o_minor); 1514 void drbd_resync_after_changed(struct drbd_device *device); 1515 extern void drbd_start_resync(struct drbd_device *device, enum drbd_conns side); 1516 extern void resume_next_sg(struct drbd_device *device); 1517 extern void suspend_other_sg(struct drbd_device *device); 1518 extern int drbd_resync_finished(struct drbd_device *device); 1519 /* maybe rather drbd_main.c ? */ 1520 extern void *drbd_md_get_buffer(struct drbd_device *device, const char *intent); 1521 extern void drbd_md_put_buffer(struct drbd_device *device); 1522 extern int drbd_md_sync_page_io(struct drbd_device *device, 1523 struct drbd_backing_dev *bdev, sector_t sector, int op); 1524 extern void drbd_ov_out_of_sync_found(struct drbd_device *, sector_t, int); 1525 extern void wait_until_done_or_force_detached(struct drbd_device *device, 1526 struct drbd_backing_dev *bdev, unsigned int *done); 1527 extern void drbd_rs_controller_reset(struct drbd_device *device); 1528 1529 static inline void ov_out_of_sync_print(struct drbd_device *device) 1530 { 1531 if (device->ov_last_oos_size) { 1532 drbd_err(device, "Out of sync: start=%llu, size=%lu (sectors)\n", 1533 (unsigned long long)device->ov_last_oos_start, 1534 (unsigned long)device->ov_last_oos_size); 1535 } 1536 device->ov_last_oos_size = 0; 1537 } 1538 1539 1540 extern void drbd_csum_bio(struct crypto_ahash *, struct bio *, void *); 1541 extern void drbd_csum_ee(struct crypto_ahash *, struct drbd_peer_request *, void *); 1542 /* worker callbacks */ 1543 extern int w_e_end_data_req(struct drbd_work *, int); 1544 extern int w_e_end_rsdata_req(struct drbd_work *, int); 1545 extern int w_e_end_csum_rs_req(struct drbd_work *, int); 1546 extern int w_e_end_ov_reply(struct drbd_work *, int); 1547 extern int w_e_end_ov_req(struct drbd_work *, int); 1548 extern int w_ov_finished(struct drbd_work *, int); 1549 extern int w_resync_timer(struct drbd_work *, int); 1550 extern int w_send_write_hint(struct drbd_work *, int); 1551 extern int w_send_dblock(struct drbd_work *, int); 1552 extern int w_send_read_req(struct drbd_work *, int); 1553 extern int w_e_reissue(struct drbd_work *, int); 1554 extern int w_restart_disk_io(struct drbd_work *, int); 1555 extern int w_send_out_of_sync(struct drbd_work *, int); 1556 extern int w_start_resync(struct drbd_work *, int); 1557 1558 extern void resync_timer_fn(unsigned long data); 1559 extern void start_resync_timer_fn(unsigned long data); 1560 1561 extern void drbd_endio_write_sec_final(struct drbd_peer_request *peer_req); 1562 1563 /* drbd_receiver.c */ 1564 extern int drbd_issue_discard_or_zero_out(struct drbd_device *device, 1565 sector_t start, unsigned int nr_sectors, bool discard); 1566 extern int drbd_receiver(struct drbd_thread *thi); 1567 extern int drbd_ack_receiver(struct drbd_thread *thi); 1568 extern void drbd_send_ping_wf(struct work_struct *ws); 1569 extern void drbd_send_acks_wf(struct work_struct *ws); 1570 extern bool drbd_rs_c_min_rate_throttle(struct drbd_device *device); 1571 extern bool drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector, 1572 bool throttle_if_app_is_waiting); 1573 extern int drbd_submit_peer_request(struct drbd_device *, 1574 struct drbd_peer_request *, const unsigned, 1575 const unsigned, const int); 1576 extern int drbd_free_peer_reqs(struct drbd_device *, struct list_head *); 1577 extern struct drbd_peer_request *drbd_alloc_peer_req(struct drbd_peer_device *, u64, 1578 sector_t, unsigned int, 1579 unsigned int, 1580 gfp_t) __must_hold(local); 1581 extern void __drbd_free_peer_req(struct drbd_device *, struct drbd_peer_request *, 1582 int); 1583 #define drbd_free_peer_req(m,e) __drbd_free_peer_req(m, e, 0) 1584 #define drbd_free_net_peer_req(m,e) __drbd_free_peer_req(m, e, 1) 1585 extern struct page *drbd_alloc_pages(struct drbd_peer_device *, unsigned int, bool); 1586 extern void drbd_set_recv_tcq(struct drbd_device *device, int tcq_enabled); 1587 extern void _drbd_clear_done_ee(struct drbd_device *device, struct list_head *to_be_freed); 1588 extern int drbd_connected(struct drbd_peer_device *); 1589 1590 static inline void drbd_tcp_cork(struct socket *sock) 1591 { 1592 int val = 1; 1593 (void) kernel_setsockopt(sock, SOL_TCP, TCP_CORK, 1594 (char*)&val, sizeof(val)); 1595 } 1596 1597 static inline void drbd_tcp_uncork(struct socket *sock) 1598 { 1599 int val = 0; 1600 (void) kernel_setsockopt(sock, SOL_TCP, TCP_CORK, 1601 (char*)&val, sizeof(val)); 1602 } 1603 1604 static inline void drbd_tcp_nodelay(struct socket *sock) 1605 { 1606 int val = 1; 1607 (void) kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, 1608 (char*)&val, sizeof(val)); 1609 } 1610 1611 static inline void drbd_tcp_quickack(struct socket *sock) 1612 { 1613 int val = 2; 1614 (void) kernel_setsockopt(sock, SOL_TCP, TCP_QUICKACK, 1615 (char*)&val, sizeof(val)); 1616 } 1617 1618 /* sets the number of 512 byte sectors of our virtual device */ 1619 static inline void drbd_set_my_capacity(struct drbd_device *device, 1620 sector_t size) 1621 { 1622 /* set_capacity(device->this_bdev->bd_disk, size); */ 1623 set_capacity(device->vdisk, size); 1624 device->this_bdev->bd_inode->i_size = (loff_t)size << 9; 1625 } 1626 1627 /* 1628 * used to submit our private bio 1629 */ 1630 static inline void drbd_generic_make_request(struct drbd_device *device, 1631 int fault_type, struct bio *bio) 1632 { 1633 __release(local); 1634 if (!bio->bi_bdev) { 1635 drbd_err(device, "drbd_generic_make_request: bio->bi_bdev == NULL\n"); 1636 bio->bi_error = -ENODEV; 1637 bio_endio(bio); 1638 return; 1639 } 1640 1641 if (drbd_insert_fault(device, fault_type)) 1642 bio_io_error(bio); 1643 else 1644 generic_make_request(bio); 1645 } 1646 1647 void drbd_bump_write_ordering(struct drbd_resource *resource, struct drbd_backing_dev *bdev, 1648 enum write_ordering_e wo); 1649 1650 /* drbd_proc.c */ 1651 extern struct proc_dir_entry *drbd_proc; 1652 extern const struct file_operations drbd_proc_fops; 1653 1654 /* drbd_actlog.c */ 1655 extern bool drbd_al_begin_io_prepare(struct drbd_device *device, struct drbd_interval *i); 1656 extern int drbd_al_begin_io_nonblock(struct drbd_device *device, struct drbd_interval *i); 1657 extern void drbd_al_begin_io_commit(struct drbd_device *device); 1658 extern bool drbd_al_begin_io_fastpath(struct drbd_device *device, struct drbd_interval *i); 1659 extern void drbd_al_begin_io(struct drbd_device *device, struct drbd_interval *i); 1660 extern void drbd_al_complete_io(struct drbd_device *device, struct drbd_interval *i); 1661 extern void drbd_rs_complete_io(struct drbd_device *device, sector_t sector); 1662 extern int drbd_rs_begin_io(struct drbd_device *device, sector_t sector); 1663 extern int drbd_try_rs_begin_io(struct drbd_device *device, sector_t sector); 1664 extern void drbd_rs_cancel_all(struct drbd_device *device); 1665 extern int drbd_rs_del_all(struct drbd_device *device); 1666 extern void drbd_rs_failed_io(struct drbd_device *device, 1667 sector_t sector, int size); 1668 extern void drbd_advance_rs_marks(struct drbd_device *device, unsigned long still_to_go); 1669 1670 enum update_sync_bits_mode { RECORD_RS_FAILED, SET_OUT_OF_SYNC, SET_IN_SYNC }; 1671 extern int __drbd_change_sync(struct drbd_device *device, sector_t sector, int size, 1672 enum update_sync_bits_mode mode); 1673 #define drbd_set_in_sync(device, sector, size) \ 1674 __drbd_change_sync(device, sector, size, SET_IN_SYNC) 1675 #define drbd_set_out_of_sync(device, sector, size) \ 1676 __drbd_change_sync(device, sector, size, SET_OUT_OF_SYNC) 1677 #define drbd_rs_failed_io(device, sector, size) \ 1678 __drbd_change_sync(device, sector, size, RECORD_RS_FAILED) 1679 extern void drbd_al_shrink(struct drbd_device *device); 1680 extern int drbd_al_initialize(struct drbd_device *, void *); 1681 1682 /* drbd_nl.c */ 1683 /* state info broadcast */ 1684 struct sib_info { 1685 enum drbd_state_info_bcast_reason sib_reason; 1686 union { 1687 struct { 1688 char *helper_name; 1689 unsigned helper_exit_code; 1690 }; 1691 struct { 1692 union drbd_state os; 1693 union drbd_state ns; 1694 }; 1695 }; 1696 }; 1697 void drbd_bcast_event(struct drbd_device *device, const struct sib_info *sib); 1698 1699 extern void notify_resource_state(struct sk_buff *, 1700 unsigned int, 1701 struct drbd_resource *, 1702 struct resource_info *, 1703 enum drbd_notification_type); 1704 extern void notify_device_state(struct sk_buff *, 1705 unsigned int, 1706 struct drbd_device *, 1707 struct device_info *, 1708 enum drbd_notification_type); 1709 extern void notify_connection_state(struct sk_buff *, 1710 unsigned int, 1711 struct drbd_connection *, 1712 struct connection_info *, 1713 enum drbd_notification_type); 1714 extern void notify_peer_device_state(struct sk_buff *, 1715 unsigned int, 1716 struct drbd_peer_device *, 1717 struct peer_device_info *, 1718 enum drbd_notification_type); 1719 extern void notify_helper(enum drbd_notification_type, struct drbd_device *, 1720 struct drbd_connection *, const char *, int); 1721 1722 /* 1723 * inline helper functions 1724 *************************/ 1725 1726 /* see also page_chain_add and friends in drbd_receiver.c */ 1727 static inline struct page *page_chain_next(struct page *page) 1728 { 1729 return (struct page *)page_private(page); 1730 } 1731 #define page_chain_for_each(page) \ 1732 for (; page && ({ prefetch(page_chain_next(page)); 1; }); \ 1733 page = page_chain_next(page)) 1734 #define page_chain_for_each_safe(page, n) \ 1735 for (; page && ({ n = page_chain_next(page); 1; }); page = n) 1736 1737 1738 static inline int drbd_peer_req_has_active_page(struct drbd_peer_request *peer_req) 1739 { 1740 struct page *page = peer_req->pages; 1741 page_chain_for_each(page) { 1742 if (page_count(page) > 1) 1743 return 1; 1744 } 1745 return 0; 1746 } 1747 1748 static inline union drbd_state drbd_read_state(struct drbd_device *device) 1749 { 1750 struct drbd_resource *resource = device->resource; 1751 union drbd_state rv; 1752 1753 rv.i = device->state.i; 1754 rv.susp = resource->susp; 1755 rv.susp_nod = resource->susp_nod; 1756 rv.susp_fen = resource->susp_fen; 1757 1758 return rv; 1759 } 1760 1761 enum drbd_force_detach_flags { 1762 DRBD_READ_ERROR, 1763 DRBD_WRITE_ERROR, 1764 DRBD_META_IO_ERROR, 1765 DRBD_FORCE_DETACH, 1766 }; 1767 1768 #define __drbd_chk_io_error(m,f) __drbd_chk_io_error_(m,f, __func__) 1769 static inline void __drbd_chk_io_error_(struct drbd_device *device, 1770 enum drbd_force_detach_flags df, 1771 const char *where) 1772 { 1773 enum drbd_io_error_p ep; 1774 1775 rcu_read_lock(); 1776 ep = rcu_dereference(device->ldev->disk_conf)->on_io_error; 1777 rcu_read_unlock(); 1778 switch (ep) { 1779 case EP_PASS_ON: /* FIXME would this be better named "Ignore"? */ 1780 if (df == DRBD_READ_ERROR || df == DRBD_WRITE_ERROR) { 1781 if (__ratelimit(&drbd_ratelimit_state)) 1782 drbd_err(device, "Local IO failed in %s.\n", where); 1783 if (device->state.disk > D_INCONSISTENT) 1784 _drbd_set_state(_NS(device, disk, D_INCONSISTENT), CS_HARD, NULL); 1785 break; 1786 } 1787 /* NOTE fall through for DRBD_META_IO_ERROR or DRBD_FORCE_DETACH */ 1788 case EP_DETACH: 1789 case EP_CALL_HELPER: 1790 /* Remember whether we saw a READ or WRITE error. 1791 * 1792 * Recovery of the affected area for WRITE failure is covered 1793 * by the activity log. 1794 * READ errors may fall outside that area though. Certain READ 1795 * errors can be "healed" by writing good data to the affected 1796 * blocks, which triggers block re-allocation in lower layers. 1797 * 1798 * If we can not write the bitmap after a READ error, 1799 * we may need to trigger a full sync (see w_go_diskless()). 1800 * 1801 * Force-detach is not really an IO error, but rather a 1802 * desperate measure to try to deal with a completely 1803 * unresponsive lower level IO stack. 1804 * Still it should be treated as a WRITE error. 1805 * 1806 * Meta IO error is always WRITE error: 1807 * we read meta data only once during attach, 1808 * which will fail in case of errors. 1809 */ 1810 set_bit(WAS_IO_ERROR, &device->flags); 1811 if (df == DRBD_READ_ERROR) 1812 set_bit(WAS_READ_ERROR, &device->flags); 1813 if (df == DRBD_FORCE_DETACH) 1814 set_bit(FORCE_DETACH, &device->flags); 1815 if (device->state.disk > D_FAILED) { 1816 _drbd_set_state(_NS(device, disk, D_FAILED), CS_HARD, NULL); 1817 drbd_err(device, 1818 "Local IO failed in %s. Detaching...\n", where); 1819 } 1820 break; 1821 } 1822 } 1823 1824 /** 1825 * drbd_chk_io_error: Handle the on_io_error setting, should be called from all io completion handlers 1826 * @device: DRBD device. 1827 * @error: Error code passed to the IO completion callback 1828 * @forcedetach: Force detach. I.e. the error happened while accessing the meta data 1829 * 1830 * See also drbd_main.c:after_state_ch() if (os.disk > D_FAILED && ns.disk == D_FAILED) 1831 */ 1832 #define drbd_chk_io_error(m,e,f) drbd_chk_io_error_(m,e,f, __func__) 1833 static inline void drbd_chk_io_error_(struct drbd_device *device, 1834 int error, enum drbd_force_detach_flags forcedetach, const char *where) 1835 { 1836 if (error) { 1837 unsigned long flags; 1838 spin_lock_irqsave(&device->resource->req_lock, flags); 1839 __drbd_chk_io_error_(device, forcedetach, where); 1840 spin_unlock_irqrestore(&device->resource->req_lock, flags); 1841 } 1842 } 1843 1844 1845 /** 1846 * drbd_md_first_sector() - Returns the first sector number of the meta data area 1847 * @bdev: Meta data block device. 1848 * 1849 * BTW, for internal meta data, this happens to be the maximum capacity 1850 * we could agree upon with our peer node. 1851 */ 1852 static inline sector_t drbd_md_first_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 + bdev->md.bm_offset; 1858 case DRBD_MD_INDEX_FLEX_EXT: 1859 default: 1860 return bdev->md.md_offset; 1861 } 1862 } 1863 1864 /** 1865 * drbd_md_last_sector() - Return the last sector number of the meta data area 1866 * @bdev: Meta data block device. 1867 */ 1868 static inline sector_t drbd_md_last_sector(struct drbd_backing_dev *bdev) 1869 { 1870 switch (bdev->md.meta_dev_idx) { 1871 case DRBD_MD_INDEX_INTERNAL: 1872 case DRBD_MD_INDEX_FLEX_INT: 1873 return bdev->md.md_offset + MD_4kB_SECT -1; 1874 case DRBD_MD_INDEX_FLEX_EXT: 1875 default: 1876 return bdev->md.md_offset + bdev->md.md_size_sect -1; 1877 } 1878 } 1879 1880 /* Returns the number of 512 byte sectors of the device */ 1881 static inline sector_t drbd_get_capacity(struct block_device *bdev) 1882 { 1883 /* return bdev ? get_capacity(bdev->bd_disk) : 0; */ 1884 return bdev ? i_size_read(bdev->bd_inode) >> 9 : 0; 1885 } 1886 1887 /** 1888 * drbd_get_max_capacity() - Returns the capacity we announce to out peer 1889 * @bdev: Meta data block device. 1890 * 1891 * returns the capacity we announce to out peer. we clip ourselves at the 1892 * various MAX_SECTORS, because if we don't, current implementation will 1893 * oops sooner or later 1894 */ 1895 static inline sector_t drbd_get_max_capacity(struct drbd_backing_dev *bdev) 1896 { 1897 sector_t s; 1898 1899 switch (bdev->md.meta_dev_idx) { 1900 case DRBD_MD_INDEX_INTERNAL: 1901 case DRBD_MD_INDEX_FLEX_INT: 1902 s = drbd_get_capacity(bdev->backing_bdev) 1903 ? min_t(sector_t, DRBD_MAX_SECTORS_FLEX, 1904 drbd_md_first_sector(bdev)) 1905 : 0; 1906 break; 1907 case DRBD_MD_INDEX_FLEX_EXT: 1908 s = min_t(sector_t, DRBD_MAX_SECTORS_FLEX, 1909 drbd_get_capacity(bdev->backing_bdev)); 1910 /* clip at maximum size the meta device can support */ 1911 s = min_t(sector_t, s, 1912 BM_EXT_TO_SECT(bdev->md.md_size_sect 1913 - bdev->md.bm_offset)); 1914 break; 1915 default: 1916 s = min_t(sector_t, DRBD_MAX_SECTORS, 1917 drbd_get_capacity(bdev->backing_bdev)); 1918 } 1919 return s; 1920 } 1921 1922 /** 1923 * drbd_md_ss() - Return the sector number of our meta data super block 1924 * @bdev: Meta data block device. 1925 */ 1926 static inline sector_t drbd_md_ss(struct drbd_backing_dev *bdev) 1927 { 1928 const int meta_dev_idx = bdev->md.meta_dev_idx; 1929 1930 if (meta_dev_idx == DRBD_MD_INDEX_FLEX_EXT) 1931 return 0; 1932 1933 /* Since drbd08, internal meta data is always "flexible". 1934 * position: last 4k aligned block of 4k size */ 1935 if (meta_dev_idx == DRBD_MD_INDEX_INTERNAL || 1936 meta_dev_idx == DRBD_MD_INDEX_FLEX_INT) 1937 return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL) - 8; 1938 1939 /* external, some index; this is the old fixed size layout */ 1940 return MD_128MB_SECT * bdev->md.meta_dev_idx; 1941 } 1942 1943 static inline void 1944 drbd_queue_work(struct drbd_work_queue *q, struct drbd_work *w) 1945 { 1946 unsigned long flags; 1947 spin_lock_irqsave(&q->q_lock, flags); 1948 list_add_tail(&w->list, &q->q); 1949 spin_unlock_irqrestore(&q->q_lock, flags); 1950 wake_up(&q->q_wait); 1951 } 1952 1953 static inline void 1954 drbd_queue_work_if_unqueued(struct drbd_work_queue *q, struct drbd_work *w) 1955 { 1956 unsigned long flags; 1957 spin_lock_irqsave(&q->q_lock, flags); 1958 if (list_empty_careful(&w->list)) 1959 list_add_tail(&w->list, &q->q); 1960 spin_unlock_irqrestore(&q->q_lock, flags); 1961 wake_up(&q->q_wait); 1962 } 1963 1964 static inline void 1965 drbd_device_post_work(struct drbd_device *device, int work_bit) 1966 { 1967 if (!test_and_set_bit(work_bit, &device->flags)) { 1968 struct drbd_connection *connection = 1969 first_peer_device(device)->connection; 1970 struct drbd_work_queue *q = &connection->sender_work; 1971 if (!test_and_set_bit(DEVICE_WORK_PENDING, &connection->flags)) 1972 wake_up(&q->q_wait); 1973 } 1974 } 1975 1976 extern void drbd_flush_workqueue(struct drbd_work_queue *work_queue); 1977 1978 /* To get the ack_receiver out of the blocking network stack, 1979 * so it can change its sk_rcvtimeo from idle- to ping-timeout, 1980 * and send a ping, we need to send a signal. 1981 * Which signal we send is irrelevant. */ 1982 static inline void wake_ack_receiver(struct drbd_connection *connection) 1983 { 1984 struct task_struct *task = connection->ack_receiver.task; 1985 if (task && get_t_state(&connection->ack_receiver) == RUNNING) 1986 force_sig(SIGXCPU, task); 1987 } 1988 1989 static inline void request_ping(struct drbd_connection *connection) 1990 { 1991 set_bit(SEND_PING, &connection->flags); 1992 wake_ack_receiver(connection); 1993 } 1994 1995 extern void *conn_prepare_command(struct drbd_connection *, struct drbd_socket *); 1996 extern void *drbd_prepare_command(struct drbd_peer_device *, struct drbd_socket *); 1997 extern int conn_send_command(struct drbd_connection *, struct drbd_socket *, 1998 enum drbd_packet, unsigned int, void *, 1999 unsigned int); 2000 extern int drbd_send_command(struct drbd_peer_device *, struct drbd_socket *, 2001 enum drbd_packet, unsigned int, void *, 2002 unsigned int); 2003 2004 extern int drbd_send_ping(struct drbd_connection *connection); 2005 extern int drbd_send_ping_ack(struct drbd_connection *connection); 2006 extern int drbd_send_state_req(struct drbd_peer_device *, union drbd_state, union drbd_state); 2007 extern int conn_send_state_req(struct drbd_connection *, union drbd_state, union drbd_state); 2008 2009 static inline void drbd_thread_stop(struct drbd_thread *thi) 2010 { 2011 _drbd_thread_stop(thi, false, true); 2012 } 2013 2014 static inline void drbd_thread_stop_nowait(struct drbd_thread *thi) 2015 { 2016 _drbd_thread_stop(thi, false, false); 2017 } 2018 2019 static inline void drbd_thread_restart_nowait(struct drbd_thread *thi) 2020 { 2021 _drbd_thread_stop(thi, true, false); 2022 } 2023 2024 /* counts how many answer packets packets we expect from our peer, 2025 * for either explicit application requests, 2026 * or implicit barrier packets as necessary. 2027 * increased: 2028 * w_send_barrier 2029 * _req_mod(req, QUEUE_FOR_NET_WRITE or QUEUE_FOR_NET_READ); 2030 * it is much easier and equally valid to count what we queue for the 2031 * worker, even before it actually was queued or send. 2032 * (drbd_make_request_common; recovery path on read io-error) 2033 * decreased: 2034 * got_BarrierAck (respective tl_clear, tl_clear_barrier) 2035 * _req_mod(req, DATA_RECEIVED) 2036 * [from receive_DataReply] 2037 * _req_mod(req, WRITE_ACKED_BY_PEER or RECV_ACKED_BY_PEER or NEG_ACKED) 2038 * [from got_BlockAck (P_WRITE_ACK, P_RECV_ACK)] 2039 * for some reason it is NOT decreased in got_NegAck, 2040 * but in the resulting cleanup code from report_params. 2041 * we should try to remember the reason for that... 2042 * _req_mod(req, SEND_FAILED or SEND_CANCELED) 2043 * _req_mod(req, CONNECTION_LOST_WHILE_PENDING) 2044 * [from tl_clear_barrier] 2045 */ 2046 static inline void inc_ap_pending(struct drbd_device *device) 2047 { 2048 atomic_inc(&device->ap_pending_cnt); 2049 } 2050 2051 #define ERR_IF_CNT_IS_NEGATIVE(which, func, line) \ 2052 if (atomic_read(&device->which) < 0) \ 2053 drbd_err(device, "in %s:%d: " #which " = %d < 0 !\n", \ 2054 func, line, \ 2055 atomic_read(&device->which)) 2056 2057 #define dec_ap_pending(device) _dec_ap_pending(device, __func__, __LINE__) 2058 static inline void _dec_ap_pending(struct drbd_device *device, const char *func, int line) 2059 { 2060 if (atomic_dec_and_test(&device->ap_pending_cnt)) 2061 wake_up(&device->misc_wait); 2062 ERR_IF_CNT_IS_NEGATIVE(ap_pending_cnt, func, line); 2063 } 2064 2065 /* counts how many resync-related answers we still expect from the peer 2066 * increase decrease 2067 * C_SYNC_TARGET sends P_RS_DATA_REQUEST (and expects P_RS_DATA_REPLY) 2068 * C_SYNC_SOURCE sends P_RS_DATA_REPLY (and expects P_WRITE_ACK with ID_SYNCER) 2069 * (or P_NEG_ACK with ID_SYNCER) 2070 */ 2071 static inline void inc_rs_pending(struct drbd_device *device) 2072 { 2073 atomic_inc(&device->rs_pending_cnt); 2074 } 2075 2076 #define dec_rs_pending(device) _dec_rs_pending(device, __func__, __LINE__) 2077 static inline void _dec_rs_pending(struct drbd_device *device, const char *func, int line) 2078 { 2079 atomic_dec(&device->rs_pending_cnt); 2080 ERR_IF_CNT_IS_NEGATIVE(rs_pending_cnt, func, line); 2081 } 2082 2083 /* counts how many answers we still need to send to the peer. 2084 * increased on 2085 * receive_Data unless protocol A; 2086 * we need to send a P_RECV_ACK (proto B) 2087 * or P_WRITE_ACK (proto C) 2088 * receive_RSDataReply (recv_resync_read) we need to send a P_WRITE_ACK 2089 * receive_DataRequest (receive_RSDataRequest) we need to send back P_DATA 2090 * receive_Barrier_* we need to send a P_BARRIER_ACK 2091 */ 2092 static inline void inc_unacked(struct drbd_device *device) 2093 { 2094 atomic_inc(&device->unacked_cnt); 2095 } 2096 2097 #define dec_unacked(device) _dec_unacked(device, __func__, __LINE__) 2098 static inline void _dec_unacked(struct drbd_device *device, const char *func, int line) 2099 { 2100 atomic_dec(&device->unacked_cnt); 2101 ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line); 2102 } 2103 2104 #define sub_unacked(device, n) _sub_unacked(device, n, __func__, __LINE__) 2105 static inline void _sub_unacked(struct drbd_device *device, int n, const char *func, int line) 2106 { 2107 atomic_sub(n, &device->unacked_cnt); 2108 ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line); 2109 } 2110 2111 static inline bool is_sync_target_state(enum drbd_conns connection_state) 2112 { 2113 return connection_state == C_SYNC_TARGET || 2114 connection_state == C_PAUSED_SYNC_T; 2115 } 2116 2117 static inline bool is_sync_source_state(enum drbd_conns connection_state) 2118 { 2119 return connection_state == C_SYNC_SOURCE || 2120 connection_state == C_PAUSED_SYNC_S; 2121 } 2122 2123 static inline bool is_sync_state(enum drbd_conns connection_state) 2124 { 2125 return is_sync_source_state(connection_state) || 2126 is_sync_target_state(connection_state); 2127 } 2128 2129 /** 2130 * get_ldev() - Increase the ref count on device->ldev. Returns 0 if there is no ldev 2131 * @_device: DRBD device. 2132 * @_min_state: Minimum device state required for success. 2133 * 2134 * You have to call put_ldev() when finished working with device->ldev. 2135 */ 2136 #define get_ldev_if_state(_device, _min_state) \ 2137 (_get_ldev_if_state((_device), (_min_state)) ? \ 2138 ({ __acquire(x); true; }) : false) 2139 #define get_ldev(_device) get_ldev_if_state(_device, D_INCONSISTENT) 2140 2141 static inline void put_ldev(struct drbd_device *device) 2142 { 2143 enum drbd_disk_state disk_state = device->state.disk; 2144 /* We must check the state *before* the atomic_dec becomes visible, 2145 * or we have a theoretical race where someone hitting zero, 2146 * while state still D_FAILED, will then see D_DISKLESS in the 2147 * condition below and calling into destroy, where he must not, yet. */ 2148 int i = atomic_dec_return(&device->local_cnt); 2149 2150 /* This may be called from some endio handler, 2151 * so we must not sleep here. */ 2152 2153 __release(local); 2154 D_ASSERT(device, i >= 0); 2155 if (i == 0) { 2156 if (disk_state == D_DISKLESS) 2157 /* even internal references gone, safe to destroy */ 2158 drbd_device_post_work(device, DESTROY_DISK); 2159 if (disk_state == D_FAILED) 2160 /* all application IO references gone. */ 2161 if (!test_and_set_bit(GOING_DISKLESS, &device->flags)) 2162 drbd_device_post_work(device, GO_DISKLESS); 2163 wake_up(&device->misc_wait); 2164 } 2165 } 2166 2167 #ifndef __CHECKER__ 2168 static inline int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins) 2169 { 2170 int io_allowed; 2171 2172 /* never get a reference while D_DISKLESS */ 2173 if (device->state.disk == D_DISKLESS) 2174 return 0; 2175 2176 atomic_inc(&device->local_cnt); 2177 io_allowed = (device->state.disk >= mins); 2178 if (!io_allowed) 2179 put_ldev(device); 2180 return io_allowed; 2181 } 2182 #else 2183 extern int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins); 2184 #endif 2185 2186 /* this throttles on-the-fly application requests 2187 * according to max_buffers settings; 2188 * maybe re-implement using semaphores? */ 2189 static inline int drbd_get_max_buffers(struct drbd_device *device) 2190 { 2191 struct net_conf *nc; 2192 int mxb; 2193 2194 rcu_read_lock(); 2195 nc = rcu_dereference(first_peer_device(device)->connection->net_conf); 2196 mxb = nc ? nc->max_buffers : 1000000; /* arbitrary limit on open requests */ 2197 rcu_read_unlock(); 2198 2199 return mxb; 2200 } 2201 2202 static inline int drbd_state_is_stable(struct drbd_device *device) 2203 { 2204 union drbd_dev_state s = device->state; 2205 2206 /* DO NOT add a default clause, we want the compiler to warn us 2207 * for any newly introduced state we may have forgotten to add here */ 2208 2209 switch ((enum drbd_conns)s.conn) { 2210 /* new io only accepted when there is no connection, ... */ 2211 case C_STANDALONE: 2212 case C_WF_CONNECTION: 2213 /* ... or there is a well established connection. */ 2214 case C_CONNECTED: 2215 case C_SYNC_SOURCE: 2216 case C_SYNC_TARGET: 2217 case C_VERIFY_S: 2218 case C_VERIFY_T: 2219 case C_PAUSED_SYNC_S: 2220 case C_PAUSED_SYNC_T: 2221 case C_AHEAD: 2222 case C_BEHIND: 2223 /* transitional states, IO allowed */ 2224 case C_DISCONNECTING: 2225 case C_UNCONNECTED: 2226 case C_TIMEOUT: 2227 case C_BROKEN_PIPE: 2228 case C_NETWORK_FAILURE: 2229 case C_PROTOCOL_ERROR: 2230 case C_TEAR_DOWN: 2231 case C_WF_REPORT_PARAMS: 2232 case C_STARTING_SYNC_S: 2233 case C_STARTING_SYNC_T: 2234 break; 2235 2236 /* Allow IO in BM exchange states with new protocols */ 2237 case C_WF_BITMAP_S: 2238 if (first_peer_device(device)->connection->agreed_pro_version < 96) 2239 return 0; 2240 break; 2241 2242 /* no new io accepted in these states */ 2243 case C_WF_BITMAP_T: 2244 case C_WF_SYNC_UUID: 2245 case C_MASK: 2246 /* not "stable" */ 2247 return 0; 2248 } 2249 2250 switch ((enum drbd_disk_state)s.disk) { 2251 case D_DISKLESS: 2252 case D_INCONSISTENT: 2253 case D_OUTDATED: 2254 case D_CONSISTENT: 2255 case D_UP_TO_DATE: 2256 case D_FAILED: 2257 /* disk state is stable as well. */ 2258 break; 2259 2260 /* no new io accepted during transitional states */ 2261 case D_ATTACHING: 2262 case D_NEGOTIATING: 2263 case D_UNKNOWN: 2264 case D_MASK: 2265 /* not "stable" */ 2266 return 0; 2267 } 2268 2269 return 1; 2270 } 2271 2272 static inline int drbd_suspended(struct drbd_device *device) 2273 { 2274 struct drbd_resource *resource = device->resource; 2275 2276 return resource->susp || resource->susp_fen || resource->susp_nod; 2277 } 2278 2279 static inline bool may_inc_ap_bio(struct drbd_device *device) 2280 { 2281 int mxb = drbd_get_max_buffers(device); 2282 2283 if (drbd_suspended(device)) 2284 return false; 2285 if (atomic_read(&device->suspend_cnt)) 2286 return false; 2287 2288 /* to avoid potential deadlock or bitmap corruption, 2289 * in various places, we only allow new application io 2290 * to start during "stable" states. */ 2291 2292 /* no new io accepted when attaching or detaching the disk */ 2293 if (!drbd_state_is_stable(device)) 2294 return false; 2295 2296 /* since some older kernels don't have atomic_add_unless, 2297 * and we are within the spinlock anyways, we have this workaround. */ 2298 if (atomic_read(&device->ap_bio_cnt) > mxb) 2299 return false; 2300 if (test_bit(BITMAP_IO, &device->flags)) 2301 return false; 2302 return true; 2303 } 2304 2305 static inline bool inc_ap_bio_cond(struct drbd_device *device) 2306 { 2307 bool rv = false; 2308 2309 spin_lock_irq(&device->resource->req_lock); 2310 rv = may_inc_ap_bio(device); 2311 if (rv) 2312 atomic_inc(&device->ap_bio_cnt); 2313 spin_unlock_irq(&device->resource->req_lock); 2314 2315 return rv; 2316 } 2317 2318 static inline void inc_ap_bio(struct drbd_device *device) 2319 { 2320 /* we wait here 2321 * as long as the device is suspended 2322 * until the bitmap is no longer on the fly during connection 2323 * handshake as long as we would exceed the max_buffer limit. 2324 * 2325 * to avoid races with the reconnect code, 2326 * we need to atomic_inc within the spinlock. */ 2327 2328 wait_event(device->misc_wait, inc_ap_bio_cond(device)); 2329 } 2330 2331 static inline void dec_ap_bio(struct drbd_device *device) 2332 { 2333 int mxb = drbd_get_max_buffers(device); 2334 int ap_bio = atomic_dec_return(&device->ap_bio_cnt); 2335 2336 D_ASSERT(device, ap_bio >= 0); 2337 2338 if (ap_bio == 0 && test_bit(BITMAP_IO, &device->flags)) { 2339 if (!test_and_set_bit(BITMAP_IO_QUEUED, &device->flags)) 2340 drbd_queue_work(&first_peer_device(device)-> 2341 connection->sender_work, 2342 &device->bm_io_work.w); 2343 } 2344 2345 /* this currently does wake_up for every dec_ap_bio! 2346 * maybe rather introduce some type of hysteresis? 2347 * e.g. (ap_bio == mxb/2 || ap_bio == 0) ? */ 2348 if (ap_bio < mxb) 2349 wake_up(&device->misc_wait); 2350 } 2351 2352 static inline bool verify_can_do_stop_sector(struct drbd_device *device) 2353 { 2354 return first_peer_device(device)->connection->agreed_pro_version >= 97 && 2355 first_peer_device(device)->connection->agreed_pro_version != 100; 2356 } 2357 2358 static inline int drbd_set_ed_uuid(struct drbd_device *device, u64 val) 2359 { 2360 int changed = device->ed_uuid != val; 2361 device->ed_uuid = val; 2362 return changed; 2363 } 2364 2365 static inline int drbd_queue_order_type(struct drbd_device *device) 2366 { 2367 /* sorry, we currently have no working implementation 2368 * of distributed TCQ stuff */ 2369 #ifndef QUEUE_ORDERED_NONE 2370 #define QUEUE_ORDERED_NONE 0 2371 #endif 2372 return QUEUE_ORDERED_NONE; 2373 } 2374 2375 static inline struct drbd_connection *first_connection(struct drbd_resource *resource) 2376 { 2377 return list_first_entry_or_null(&resource->connections, 2378 struct drbd_connection, connections); 2379 } 2380 2381 #endif 2382