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/version.h> 32 #include <linux/list.h> 33 #include <linux/sched.h> 34 #include <linux/bitops.h> 35 #include <linux/slab.h> 36 #include <linux/crypto.h> 37 #include <linux/ratelimit.h> 38 #include <linux/tcp.h> 39 #include <linux/mutex.h> 40 #include <linux/major.h> 41 #include <linux/blkdev.h> 42 #include <linux/genhd.h> 43 #include <net/tcp.h> 44 #include <linux/lru_cache.h> 45 46 #ifdef __CHECKER__ 47 # define __protected_by(x) __attribute__((require_context(x,1,999,"rdwr"))) 48 # define __protected_read_by(x) __attribute__((require_context(x,1,999,"read"))) 49 # define __protected_write_by(x) __attribute__((require_context(x,1,999,"write"))) 50 # define __must_hold(x) __attribute__((context(x,1,1), require_context(x,1,999,"call"))) 51 #else 52 # define __protected_by(x) 53 # define __protected_read_by(x) 54 # define __protected_write_by(x) 55 # define __must_hold(x) 56 #endif 57 58 #define __no_warn(lock, stmt) do { __acquire(lock); stmt; __release(lock); } while (0) 59 60 /* module parameter, defined in drbd_main.c */ 61 extern unsigned int minor_count; 62 extern int disable_sendpage; 63 extern int allow_oos; 64 extern unsigned int cn_idx; 65 66 #ifdef CONFIG_DRBD_FAULT_INJECTION 67 extern int enable_faults; 68 extern int fault_rate; 69 extern int fault_devs; 70 #endif 71 72 extern char usermode_helper[]; 73 74 75 #ifndef TRUE 76 #define TRUE 1 77 #endif 78 #ifndef FALSE 79 #define FALSE 0 80 #endif 81 82 /* I don't remember why XCPU ... 83 * This is used to wake the asender, 84 * and to interrupt sending the sending task 85 * on disconnect. 86 */ 87 #define DRBD_SIG SIGXCPU 88 89 /* This is used to stop/restart our threads. 90 * Cannot use SIGTERM nor SIGKILL, since these 91 * are sent out by init on runlevel changes 92 * I choose SIGHUP for now. 93 */ 94 #define DRBD_SIGKILL SIGHUP 95 96 /* All EEs on the free list should have ID_VACANT (== 0) 97 * freshly allocated EEs get !ID_VACANT (== 1) 98 * so if it says "cannot dereference null pointer at adress 0x00000001", 99 * it is most likely one of these :( */ 100 101 #define ID_IN_SYNC (4711ULL) 102 #define ID_OUT_OF_SYNC (4712ULL) 103 104 #define ID_SYNCER (-1ULL) 105 #define ID_VACANT 0 106 #define is_syncer_block_id(id) ((id) == ID_SYNCER) 107 108 struct drbd_conf; 109 110 111 /* to shorten dev_warn(DEV, "msg"); and relatives statements */ 112 #define DEV (disk_to_dev(mdev->vdisk)) 113 114 #define D_ASSERT(exp) if (!(exp)) \ 115 dev_err(DEV, "ASSERT( " #exp " ) in %s:%d\n", __FILE__, __LINE__) 116 117 #define ERR_IF(exp) if (({ \ 118 int _b = (exp) != 0; \ 119 if (_b) dev_err(DEV, "%s: (%s) in %s:%d\n", \ 120 __func__, #exp, __FILE__, __LINE__); \ 121 _b; \ 122 })) 123 124 /* Defines to control fault insertion */ 125 enum { 126 DRBD_FAULT_MD_WR = 0, /* meta data write */ 127 DRBD_FAULT_MD_RD = 1, /* read */ 128 DRBD_FAULT_RS_WR = 2, /* resync */ 129 DRBD_FAULT_RS_RD = 3, 130 DRBD_FAULT_DT_WR = 4, /* data */ 131 DRBD_FAULT_DT_RD = 5, 132 DRBD_FAULT_DT_RA = 6, /* data read ahead */ 133 DRBD_FAULT_BM_ALLOC = 7, /* bitmap allocation */ 134 DRBD_FAULT_AL_EE = 8, /* alloc ee */ 135 136 DRBD_FAULT_MAX, 137 }; 138 139 #ifdef CONFIG_DRBD_FAULT_INJECTION 140 extern unsigned int 141 _drbd_insert_fault(struct drbd_conf *mdev, unsigned int type); 142 static inline int 143 drbd_insert_fault(struct drbd_conf *mdev, unsigned int type) { 144 return fault_rate && 145 (enable_faults & (1<<type)) && 146 _drbd_insert_fault(mdev, type); 147 } 148 #define FAULT_ACTIVE(_m, _t) (drbd_insert_fault((_m), (_t))) 149 150 #else 151 #define FAULT_ACTIVE(_m, _t) (0) 152 #endif 153 154 /* integer division, round _UP_ to the next integer */ 155 #define div_ceil(A, B) ((A)/(B) + ((A)%(B) ? 1 : 0)) 156 /* usual integer division */ 157 #define div_floor(A, B) ((A)/(B)) 158 159 /* drbd_meta-data.c (still in drbd_main.c) */ 160 /* 4th incarnation of the disk layout. */ 161 #define DRBD_MD_MAGIC (DRBD_MAGIC+4) 162 163 extern struct drbd_conf **minor_table; 164 extern struct ratelimit_state drbd_ratelimit_state; 165 166 /* on the wire */ 167 enum drbd_packets { 168 /* receiver (data socket) */ 169 P_DATA = 0x00, 170 P_DATA_REPLY = 0x01, /* Response to P_DATA_REQUEST */ 171 P_RS_DATA_REPLY = 0x02, /* Response to P_RS_DATA_REQUEST */ 172 P_BARRIER = 0x03, 173 P_BITMAP = 0x04, 174 P_BECOME_SYNC_TARGET = 0x05, 175 P_BECOME_SYNC_SOURCE = 0x06, 176 P_UNPLUG_REMOTE = 0x07, /* Used at various times to hint the peer */ 177 P_DATA_REQUEST = 0x08, /* Used to ask for a data block */ 178 P_RS_DATA_REQUEST = 0x09, /* Used to ask for a data block for resync */ 179 P_SYNC_PARAM = 0x0a, 180 P_PROTOCOL = 0x0b, 181 P_UUIDS = 0x0c, 182 P_SIZES = 0x0d, 183 P_STATE = 0x0e, 184 P_SYNC_UUID = 0x0f, 185 P_AUTH_CHALLENGE = 0x10, 186 P_AUTH_RESPONSE = 0x11, 187 P_STATE_CHG_REQ = 0x12, 188 189 /* asender (meta socket */ 190 P_PING = 0x13, 191 P_PING_ACK = 0x14, 192 P_RECV_ACK = 0x15, /* Used in protocol B */ 193 P_WRITE_ACK = 0x16, /* Used in protocol C */ 194 P_RS_WRITE_ACK = 0x17, /* Is a P_WRITE_ACK, additionally call set_in_sync(). */ 195 P_DISCARD_ACK = 0x18, /* Used in proto C, two-primaries conflict detection */ 196 P_NEG_ACK = 0x19, /* Sent if local disk is unusable */ 197 P_NEG_DREPLY = 0x1a, /* Local disk is broken... */ 198 P_NEG_RS_DREPLY = 0x1b, /* Local disk is broken... */ 199 P_BARRIER_ACK = 0x1c, 200 P_STATE_CHG_REPLY = 0x1d, 201 202 /* "new" commands, no longer fitting into the ordering scheme above */ 203 204 P_OV_REQUEST = 0x1e, /* data socket */ 205 P_OV_REPLY = 0x1f, 206 P_OV_RESULT = 0x20, /* meta socket */ 207 P_CSUM_RS_REQUEST = 0x21, /* data socket */ 208 P_RS_IS_IN_SYNC = 0x22, /* meta socket */ 209 P_SYNC_PARAM89 = 0x23, /* data socket, protocol version 89 replacement for P_SYNC_PARAM */ 210 P_COMPRESSED_BITMAP = 0x24, /* compressed or otherwise encoded bitmap transfer */ 211 212 P_MAX_CMD = 0x25, 213 P_MAY_IGNORE = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */ 214 P_MAX_OPT_CMD = 0x101, 215 216 /* special command ids for handshake */ 217 218 P_HAND_SHAKE_M = 0xfff1, /* First Packet on the MetaSock */ 219 P_HAND_SHAKE_S = 0xfff2, /* First Packet on the Socket */ 220 221 P_HAND_SHAKE = 0xfffe /* FIXED for the next century! */ 222 }; 223 224 static inline const char *cmdname(enum drbd_packets cmd) 225 { 226 /* THINK may need to become several global tables 227 * when we want to support more than 228 * one PRO_VERSION */ 229 static const char *cmdnames[] = { 230 [P_DATA] = "Data", 231 [P_DATA_REPLY] = "DataReply", 232 [P_RS_DATA_REPLY] = "RSDataReply", 233 [P_BARRIER] = "Barrier", 234 [P_BITMAP] = "ReportBitMap", 235 [P_BECOME_SYNC_TARGET] = "BecomeSyncTarget", 236 [P_BECOME_SYNC_SOURCE] = "BecomeSyncSource", 237 [P_UNPLUG_REMOTE] = "UnplugRemote", 238 [P_DATA_REQUEST] = "DataRequest", 239 [P_RS_DATA_REQUEST] = "RSDataRequest", 240 [P_SYNC_PARAM] = "SyncParam", 241 [P_SYNC_PARAM89] = "SyncParam89", 242 [P_PROTOCOL] = "ReportProtocol", 243 [P_UUIDS] = "ReportUUIDs", 244 [P_SIZES] = "ReportSizes", 245 [P_STATE] = "ReportState", 246 [P_SYNC_UUID] = "ReportSyncUUID", 247 [P_AUTH_CHALLENGE] = "AuthChallenge", 248 [P_AUTH_RESPONSE] = "AuthResponse", 249 [P_PING] = "Ping", 250 [P_PING_ACK] = "PingAck", 251 [P_RECV_ACK] = "RecvAck", 252 [P_WRITE_ACK] = "WriteAck", 253 [P_RS_WRITE_ACK] = "RSWriteAck", 254 [P_DISCARD_ACK] = "DiscardAck", 255 [P_NEG_ACK] = "NegAck", 256 [P_NEG_DREPLY] = "NegDReply", 257 [P_NEG_RS_DREPLY] = "NegRSDReply", 258 [P_BARRIER_ACK] = "BarrierAck", 259 [P_STATE_CHG_REQ] = "StateChgRequest", 260 [P_STATE_CHG_REPLY] = "StateChgReply", 261 [P_OV_REQUEST] = "OVRequest", 262 [P_OV_REPLY] = "OVReply", 263 [P_OV_RESULT] = "OVResult", 264 [P_MAX_CMD] = NULL, 265 }; 266 267 if (cmd == P_HAND_SHAKE_M) 268 return "HandShakeM"; 269 if (cmd == P_HAND_SHAKE_S) 270 return "HandShakeS"; 271 if (cmd == P_HAND_SHAKE) 272 return "HandShake"; 273 if (cmd >= P_MAX_CMD) 274 return "Unknown"; 275 return cmdnames[cmd]; 276 } 277 278 /* for sending/receiving the bitmap, 279 * possibly in some encoding scheme */ 280 struct bm_xfer_ctx { 281 /* "const" 282 * stores total bits and long words 283 * of the bitmap, so we don't need to 284 * call the accessor functions over and again. */ 285 unsigned long bm_bits; 286 unsigned long bm_words; 287 /* during xfer, current position within the bitmap */ 288 unsigned long bit_offset; 289 unsigned long word_offset; 290 291 /* statistics; index: (h->command == P_BITMAP) */ 292 unsigned packets[2]; 293 unsigned bytes[2]; 294 }; 295 296 extern void INFO_bm_xfer_stats(struct drbd_conf *mdev, 297 const char *direction, struct bm_xfer_ctx *c); 298 299 static inline void bm_xfer_ctx_bit_to_word_offset(struct bm_xfer_ctx *c) 300 { 301 /* word_offset counts "native long words" (32 or 64 bit), 302 * aligned at 64 bit. 303 * Encoded packet may end at an unaligned bit offset. 304 * In case a fallback clear text packet is transmitted in 305 * between, we adjust this offset back to the last 64bit 306 * aligned "native long word", which makes coding and decoding 307 * the plain text bitmap much more convenient. */ 308 #if BITS_PER_LONG == 64 309 c->word_offset = c->bit_offset >> 6; 310 #elif BITS_PER_LONG == 32 311 c->word_offset = c->bit_offset >> 5; 312 c->word_offset &= ~(1UL); 313 #else 314 # error "unsupported BITS_PER_LONG" 315 #endif 316 } 317 318 #ifndef __packed 319 #define __packed __attribute__((packed)) 320 #endif 321 322 /* This is the layout for a packet on the wire. 323 * The byteorder is the network byte order. 324 * (except block_id and barrier fields. 325 * these are pointers to local structs 326 * and have no relevance for the partner, 327 * which just echoes them as received.) 328 * 329 * NOTE that the payload starts at a long aligned offset, 330 * regardless of 32 or 64 bit arch! 331 */ 332 struct p_header { 333 u32 magic; 334 u16 command; 335 u16 length; /* bytes of data after this header */ 336 u8 payload[0]; 337 } __packed; 338 /* 8 bytes. packet FIXED for the next century! */ 339 340 /* 341 * short commands, packets without payload, plain p_header: 342 * P_PING 343 * P_PING_ACK 344 * P_BECOME_SYNC_TARGET 345 * P_BECOME_SYNC_SOURCE 346 * P_UNPLUG_REMOTE 347 */ 348 349 /* 350 * commands with out-of-struct payload: 351 * P_BITMAP (no additional fields) 352 * P_DATA, P_DATA_REPLY (see p_data) 353 * P_COMPRESSED_BITMAP (see receive_compressed_bitmap) 354 */ 355 356 /* these defines must not be changed without changing the protocol version */ 357 #define DP_HARDBARRIER 1 358 #define DP_RW_SYNC 2 359 #define DP_MAY_SET_IN_SYNC 4 360 361 struct p_data { 362 struct p_header head; 363 u64 sector; /* 64 bits sector number */ 364 u64 block_id; /* to identify the request in protocol B&C */ 365 u32 seq_num; 366 u32 dp_flags; 367 } __packed; 368 369 /* 370 * commands which share a struct: 371 * p_block_ack: 372 * P_RECV_ACK (proto B), P_WRITE_ACK (proto C), 373 * P_DISCARD_ACK (proto C, two-primaries conflict detection) 374 * p_block_req: 375 * P_DATA_REQUEST, P_RS_DATA_REQUEST 376 */ 377 struct p_block_ack { 378 struct p_header head; 379 u64 sector; 380 u64 block_id; 381 u32 blksize; 382 u32 seq_num; 383 } __packed; 384 385 386 struct p_block_req { 387 struct p_header head; 388 u64 sector; 389 u64 block_id; 390 u32 blksize; 391 u32 pad; /* to multiple of 8 Byte */ 392 } __packed; 393 394 /* 395 * commands with their own struct for additional fields: 396 * P_HAND_SHAKE 397 * P_BARRIER 398 * P_BARRIER_ACK 399 * P_SYNC_PARAM 400 * ReportParams 401 */ 402 403 struct p_handshake { 404 struct p_header head; /* 8 bytes */ 405 u32 protocol_min; 406 u32 feature_flags; 407 u32 protocol_max; 408 409 /* should be more than enough for future enhancements 410 * for now, feature_flags and the reserverd array shall be zero. 411 */ 412 413 u32 _pad; 414 u64 reserverd[7]; 415 } __packed; 416 /* 80 bytes, FIXED for the next century */ 417 418 struct p_barrier { 419 struct p_header head; 420 u32 barrier; /* barrier number _handle_ only */ 421 u32 pad; /* to multiple of 8 Byte */ 422 } __packed; 423 424 struct p_barrier_ack { 425 struct p_header head; 426 u32 barrier; 427 u32 set_size; 428 } __packed; 429 430 struct p_rs_param { 431 struct p_header head; 432 u32 rate; 433 434 /* Since protocol version 88 and higher. */ 435 char verify_alg[0]; 436 } __packed; 437 438 struct p_rs_param_89 { 439 struct p_header head; 440 u32 rate; 441 /* protocol version 89: */ 442 char verify_alg[SHARED_SECRET_MAX]; 443 char csums_alg[SHARED_SECRET_MAX]; 444 } __packed; 445 446 struct p_protocol { 447 struct p_header head; 448 u32 protocol; 449 u32 after_sb_0p; 450 u32 after_sb_1p; 451 u32 after_sb_2p; 452 u32 want_lose; 453 u32 two_primaries; 454 455 /* Since protocol version 87 and higher. */ 456 char integrity_alg[0]; 457 458 } __packed; 459 460 struct p_uuids { 461 struct p_header head; 462 u64 uuid[UI_EXTENDED_SIZE]; 463 } __packed; 464 465 struct p_rs_uuid { 466 struct p_header head; 467 u64 uuid; 468 } __packed; 469 470 struct p_sizes { 471 struct p_header head; 472 u64 d_size; /* size of disk */ 473 u64 u_size; /* user requested size */ 474 u64 c_size; /* current exported size */ 475 u32 max_segment_size; /* Maximal size of a BIO */ 476 u32 queue_order_type; 477 } __packed; 478 479 struct p_state { 480 struct p_header head; 481 u32 state; 482 } __packed; 483 484 struct p_req_state { 485 struct p_header head; 486 u32 mask; 487 u32 val; 488 } __packed; 489 490 struct p_req_state_reply { 491 struct p_header head; 492 u32 retcode; 493 } __packed; 494 495 struct p_drbd06_param { 496 u64 size; 497 u32 state; 498 u32 blksize; 499 u32 protocol; 500 u32 version; 501 u32 gen_cnt[5]; 502 u32 bit_map_gen[5]; 503 } __packed; 504 505 struct p_discard { 506 struct p_header head; 507 u64 block_id; 508 u32 seq_num; 509 u32 pad; 510 } __packed; 511 512 /* Valid values for the encoding field. 513 * Bump proto version when changing this. */ 514 enum drbd_bitmap_code { 515 /* RLE_VLI_Bytes = 0, 516 * and other bit variants had been defined during 517 * algorithm evaluation. */ 518 RLE_VLI_Bits = 2, 519 }; 520 521 struct p_compressed_bm { 522 struct p_header head; 523 /* (encoding & 0x0f): actual encoding, see enum drbd_bitmap_code 524 * (encoding & 0x80): polarity (set/unset) of first runlength 525 * ((encoding >> 4) & 0x07): pad_bits, number of trailing zero bits 526 * used to pad up to head.length bytes 527 */ 528 u8 encoding; 529 530 u8 code[0]; 531 } __packed; 532 533 /* DCBP: Drbd Compressed Bitmap Packet ... */ 534 static inline enum drbd_bitmap_code 535 DCBP_get_code(struct p_compressed_bm *p) 536 { 537 return (enum drbd_bitmap_code)(p->encoding & 0x0f); 538 } 539 540 static inline void 541 DCBP_set_code(struct p_compressed_bm *p, enum drbd_bitmap_code code) 542 { 543 BUG_ON(code & ~0xf); 544 p->encoding = (p->encoding & ~0xf) | code; 545 } 546 547 static inline int 548 DCBP_get_start(struct p_compressed_bm *p) 549 { 550 return (p->encoding & 0x80) != 0; 551 } 552 553 static inline void 554 DCBP_set_start(struct p_compressed_bm *p, int set) 555 { 556 p->encoding = (p->encoding & ~0x80) | (set ? 0x80 : 0); 557 } 558 559 static inline int 560 DCBP_get_pad_bits(struct p_compressed_bm *p) 561 { 562 return (p->encoding >> 4) & 0x7; 563 } 564 565 static inline void 566 DCBP_set_pad_bits(struct p_compressed_bm *p, int n) 567 { 568 BUG_ON(n & ~0x7); 569 p->encoding = (p->encoding & (~0x7 << 4)) | (n << 4); 570 } 571 572 /* one bitmap packet, including the p_header, 573 * should fit within one _architecture independend_ page. 574 * so we need to use the fixed size 4KiB page size 575 * most architechtures have used for a long time. 576 */ 577 #define BM_PACKET_PAYLOAD_BYTES (4096 - sizeof(struct p_header)) 578 #define BM_PACKET_WORDS (BM_PACKET_PAYLOAD_BYTES/sizeof(long)) 579 #define BM_PACKET_VLI_BYTES_MAX (4096 - sizeof(struct p_compressed_bm)) 580 #if (PAGE_SIZE < 4096) 581 /* drbd_send_bitmap / receive_bitmap would break horribly */ 582 #error "PAGE_SIZE too small" 583 #endif 584 585 union p_polymorph { 586 struct p_header header; 587 struct p_handshake handshake; 588 struct p_data data; 589 struct p_block_ack block_ack; 590 struct p_barrier barrier; 591 struct p_barrier_ack barrier_ack; 592 struct p_rs_param_89 rs_param_89; 593 struct p_protocol protocol; 594 struct p_sizes sizes; 595 struct p_uuids uuids; 596 struct p_state state; 597 struct p_req_state req_state; 598 struct p_req_state_reply req_state_reply; 599 struct p_block_req block_req; 600 } __packed; 601 602 /**********************************************************************/ 603 enum drbd_thread_state { 604 None, 605 Running, 606 Exiting, 607 Restarting 608 }; 609 610 struct drbd_thread { 611 spinlock_t t_lock; 612 struct task_struct *task; 613 struct completion stop; 614 enum drbd_thread_state t_state; 615 int (*function) (struct drbd_thread *); 616 struct drbd_conf *mdev; 617 int reset_cpu_mask; 618 }; 619 620 static inline enum drbd_thread_state get_t_state(struct drbd_thread *thi) 621 { 622 /* THINK testing the t_state seems to be uncritical in all cases 623 * (but thread_{start,stop}), so we can read it *without* the lock. 624 * --lge */ 625 626 smp_rmb(); 627 return thi->t_state; 628 } 629 630 631 /* 632 * Having this as the first member of a struct provides sort of "inheritance". 633 * "derived" structs can be "drbd_queue_work()"ed. 634 * The callback should know and cast back to the descendant struct. 635 * drbd_request and drbd_epoch_entry are descendants of drbd_work. 636 */ 637 struct drbd_work; 638 typedef int (*drbd_work_cb)(struct drbd_conf *, struct drbd_work *, int cancel); 639 struct drbd_work { 640 struct list_head list; 641 drbd_work_cb cb; 642 }; 643 644 struct drbd_tl_epoch; 645 struct drbd_request { 646 struct drbd_work w; 647 struct drbd_conf *mdev; 648 649 /* if local IO is not allowed, will be NULL. 650 * if local IO _is_ allowed, holds the locally submitted bio clone, 651 * or, after local IO completion, the ERR_PTR(error). 652 * see drbd_endio_pri(). */ 653 struct bio *private_bio; 654 655 struct hlist_node colision; 656 sector_t sector; 657 unsigned int size; 658 unsigned int epoch; /* barrier_nr */ 659 660 /* barrier_nr: used to check on "completion" whether this req was in 661 * the current epoch, and we therefore have to close it, 662 * starting a new epoch... 663 */ 664 665 /* up to here, the struct layout is identical to drbd_epoch_entry; 666 * we might be able to use that to our advantage... */ 667 668 struct list_head tl_requests; /* ring list in the transfer log */ 669 struct bio *master_bio; /* master bio pointer */ 670 unsigned long rq_state; /* see comments above _req_mod() */ 671 int seq_num; 672 unsigned long start_time; 673 }; 674 675 struct drbd_tl_epoch { 676 struct drbd_work w; 677 struct list_head requests; /* requests before */ 678 struct drbd_tl_epoch *next; /* pointer to the next barrier */ 679 unsigned int br_number; /* the barriers identifier. */ 680 int n_req; /* number of requests attached before this barrier */ 681 }; 682 683 struct drbd_request; 684 685 /* These Tl_epoch_entries may be in one of 6 lists: 686 active_ee .. data packet being written 687 sync_ee .. syncer block being written 688 done_ee .. block written, need to send P_WRITE_ACK 689 read_ee .. [RS]P_DATA_REQUEST being read 690 */ 691 692 struct drbd_epoch { 693 struct list_head list; 694 unsigned int barrier_nr; 695 atomic_t epoch_size; /* increased on every request added. */ 696 atomic_t active; /* increased on every req. added, and dec on every finished. */ 697 unsigned long flags; 698 }; 699 700 /* drbd_epoch flag bits */ 701 enum { 702 DE_BARRIER_IN_NEXT_EPOCH_ISSUED, 703 DE_BARRIER_IN_NEXT_EPOCH_DONE, 704 DE_CONTAINS_A_BARRIER, 705 DE_HAVE_BARRIER_NUMBER, 706 DE_IS_FINISHING, 707 }; 708 709 enum epoch_event { 710 EV_PUT, 711 EV_GOT_BARRIER_NR, 712 EV_BARRIER_DONE, 713 EV_BECAME_LAST, 714 EV_CLEANUP = 32, /* used as flag */ 715 }; 716 717 struct drbd_epoch_entry { 718 struct drbd_work w; 719 struct drbd_conf *mdev; 720 struct bio *private_bio; 721 struct hlist_node colision; 722 sector_t sector; 723 unsigned int size; 724 struct drbd_epoch *epoch; 725 726 /* up to here, the struct layout is identical to drbd_request; 727 * we might be able to use that to our advantage... */ 728 729 unsigned int flags; 730 u64 block_id; 731 }; 732 733 struct drbd_wq_barrier { 734 struct drbd_work w; 735 struct completion done; 736 }; 737 738 struct digest_info { 739 int digest_size; 740 void *digest; 741 }; 742 743 /* ee flag bits */ 744 enum { 745 __EE_CALL_AL_COMPLETE_IO, 746 __EE_CONFLICT_PENDING, 747 __EE_MAY_SET_IN_SYNC, 748 __EE_IS_BARRIER, 749 }; 750 #define EE_CALL_AL_COMPLETE_IO (1<<__EE_CALL_AL_COMPLETE_IO) 751 #define EE_CONFLICT_PENDING (1<<__EE_CONFLICT_PENDING) 752 #define EE_MAY_SET_IN_SYNC (1<<__EE_MAY_SET_IN_SYNC) 753 #define EE_IS_BARRIER (1<<__EE_IS_BARRIER) 754 755 /* global flag bits */ 756 enum { 757 CREATE_BARRIER, /* next P_DATA is preceeded by a P_BARRIER */ 758 SIGNAL_ASENDER, /* whether asender wants to be interrupted */ 759 SEND_PING, /* whether asender should send a ping asap */ 760 761 STOP_SYNC_TIMER, /* tell timer to cancel itself */ 762 UNPLUG_QUEUED, /* only relevant with kernel 2.4 */ 763 UNPLUG_REMOTE, /* sending a "UnplugRemote" could help */ 764 MD_DIRTY, /* current uuids and flags not yet on disk */ 765 DISCARD_CONCURRENT, /* Set on one node, cleared on the peer! */ 766 USE_DEGR_WFC_T, /* degr-wfc-timeout instead of wfc-timeout. */ 767 CLUSTER_ST_CHANGE, /* Cluster wide state change going on... */ 768 CL_ST_CHG_SUCCESS, 769 CL_ST_CHG_FAIL, 770 CRASHED_PRIMARY, /* This node was a crashed primary. 771 * Gets cleared when the state.conn 772 * goes into C_CONNECTED state. */ 773 WRITE_BM_AFTER_RESYNC, /* A kmalloc() during resync failed */ 774 NO_BARRIER_SUPP, /* underlying block device doesn't implement barriers */ 775 CONSIDER_RESYNC, 776 777 MD_NO_BARRIER, /* meta data device does not support barriers, 778 so don't even try */ 779 SUSPEND_IO, /* suspend application io */ 780 BITMAP_IO, /* suspend application io; 781 once no more io in flight, start bitmap io */ 782 BITMAP_IO_QUEUED, /* Started bitmap IO */ 783 RESYNC_AFTER_NEG, /* Resync after online grow after the attach&negotiate finished. */ 784 NET_CONGESTED, /* The data socket is congested */ 785 786 CONFIG_PENDING, /* serialization of (re)configuration requests. 787 * if set, also prevents the device from dying */ 788 DEVICE_DYING, /* device became unconfigured, 789 * but worker thread is still handling the cleanup. 790 * reconfiguring (nl_disk_conf, nl_net_conf) is dissalowed, 791 * while this is set. */ 792 RESIZE_PENDING, /* Size change detected locally, waiting for the response from 793 * the peer, if it changed there as well. */ 794 }; 795 796 struct drbd_bitmap; /* opaque for drbd_conf */ 797 798 /* TODO sort members for performance 799 * MAYBE group them further */ 800 801 /* THINK maybe we actually want to use the default "event/%s" worker threads 802 * or similar in linux 2.6, which uses per cpu data and threads. 803 * 804 * To be general, this might need a spin_lock member. 805 * For now, please use the mdev->req_lock to protect list_head, 806 * see drbd_queue_work below. 807 */ 808 struct drbd_work_queue { 809 struct list_head q; 810 struct semaphore s; /* producers up it, worker down()s it */ 811 spinlock_t q_lock; /* to protect the list. */ 812 }; 813 814 struct drbd_socket { 815 struct drbd_work_queue work; 816 struct mutex mutex; 817 struct socket *socket; 818 /* this way we get our 819 * send/receive buffers off the stack */ 820 union p_polymorph sbuf; 821 union p_polymorph rbuf; 822 }; 823 824 struct drbd_md { 825 u64 md_offset; /* sector offset to 'super' block */ 826 827 u64 la_size_sect; /* last agreed size, unit sectors */ 828 u64 uuid[UI_SIZE]; 829 u64 device_uuid; 830 u32 flags; 831 u32 md_size_sect; 832 833 s32 al_offset; /* signed relative sector offset to al area */ 834 s32 bm_offset; /* signed relative sector offset to bitmap */ 835 836 /* u32 al_nr_extents; important for restoring the AL 837 * is stored into sync_conf.al_extents, which in turn 838 * gets applied to act_log->nr_elements 839 */ 840 }; 841 842 /* for sync_conf and other types... */ 843 #define NL_PACKET(name, number, fields) struct name { fields }; 844 #define NL_INTEGER(pn,pr,member) int member; 845 #define NL_INT64(pn,pr,member) __u64 member; 846 #define NL_BIT(pn,pr,member) unsigned member:1; 847 #define NL_STRING(pn,pr,member,len) unsigned char member[len]; int member ## _len; 848 #include "linux/drbd_nl.h" 849 850 struct drbd_backing_dev { 851 struct block_device *backing_bdev; 852 struct block_device *md_bdev; 853 struct file *lo_file; 854 struct file *md_file; 855 struct drbd_md md; 856 struct disk_conf dc; /* The user provided config... */ 857 sector_t known_size; /* last known size of that backing device */ 858 }; 859 860 struct drbd_md_io { 861 struct drbd_conf *mdev; 862 struct completion event; 863 int error; 864 }; 865 866 struct bm_io_work { 867 struct drbd_work w; 868 char *why; 869 int (*io_fn)(struct drbd_conf *mdev); 870 void (*done)(struct drbd_conf *mdev, int rv); 871 }; 872 873 enum write_ordering_e { 874 WO_none, 875 WO_drain_io, 876 WO_bdev_flush, 877 WO_bio_barrier 878 }; 879 880 struct drbd_conf { 881 /* things that are stored as / read from meta data on disk */ 882 unsigned long flags; 883 884 /* configured by drbdsetup */ 885 struct net_conf *net_conf; /* protected by get_net_conf() and put_net_conf() */ 886 struct syncer_conf sync_conf; 887 struct drbd_backing_dev *ldev __protected_by(local); 888 889 sector_t p_size; /* partner's disk size */ 890 struct request_queue *rq_queue; 891 struct block_device *this_bdev; 892 struct gendisk *vdisk; 893 894 struct drbd_socket data; /* data/barrier/cstate/parameter packets */ 895 struct drbd_socket meta; /* ping/ack (metadata) packets */ 896 int agreed_pro_version; /* actually used protocol version */ 897 unsigned long last_received; /* in jiffies, either socket */ 898 unsigned int ko_count; 899 struct drbd_work resync_work, 900 unplug_work, 901 md_sync_work; 902 struct timer_list resync_timer; 903 struct timer_list md_sync_timer; 904 905 /* Used after attach while negotiating new disk state. */ 906 union drbd_state new_state_tmp; 907 908 union drbd_state state; 909 wait_queue_head_t misc_wait; 910 wait_queue_head_t state_wait; /* upon each state change. */ 911 unsigned int send_cnt; 912 unsigned int recv_cnt; 913 unsigned int read_cnt; 914 unsigned int writ_cnt; 915 unsigned int al_writ_cnt; 916 unsigned int bm_writ_cnt; 917 atomic_t ap_bio_cnt; /* Requests we need to complete */ 918 atomic_t ap_pending_cnt; /* AP data packets on the wire, ack expected */ 919 atomic_t rs_pending_cnt; /* RS request/data packets on the wire */ 920 atomic_t unacked_cnt; /* Need to send replys for */ 921 atomic_t local_cnt; /* Waiting for local completion */ 922 atomic_t net_cnt; /* Users of net_conf */ 923 spinlock_t req_lock; 924 struct drbd_tl_epoch *unused_spare_tle; /* for pre-allocation */ 925 struct drbd_tl_epoch *newest_tle; 926 struct drbd_tl_epoch *oldest_tle; 927 struct list_head out_of_sequence_requests; 928 struct hlist_head *tl_hash; 929 unsigned int tl_hash_s; 930 931 /* blocks to sync in this run [unit BM_BLOCK_SIZE] */ 932 unsigned long rs_total; 933 /* number of sync IOs that failed in this run */ 934 unsigned long rs_failed; 935 /* Syncer's start time [unit jiffies] */ 936 unsigned long rs_start; 937 /* cumulated time in PausedSyncX state [unit jiffies] */ 938 unsigned long rs_paused; 939 /* block not up-to-date at mark [unit BM_BLOCK_SIZE] */ 940 unsigned long rs_mark_left; 941 /* marks's time [unit jiffies] */ 942 unsigned long rs_mark_time; 943 /* skipped because csum was equeal [unit BM_BLOCK_SIZE] */ 944 unsigned long rs_same_csum; 945 946 /* where does the admin want us to start? (sector) */ 947 sector_t ov_start_sector; 948 /* where are we now? (sector) */ 949 sector_t ov_position; 950 /* Start sector of out of sync range (to merge printk reporting). */ 951 sector_t ov_last_oos_start; 952 /* size of out-of-sync range in sectors. */ 953 sector_t ov_last_oos_size; 954 unsigned long ov_left; /* in bits */ 955 struct crypto_hash *csums_tfm; 956 struct crypto_hash *verify_tfm; 957 958 struct drbd_thread receiver; 959 struct drbd_thread worker; 960 struct drbd_thread asender; 961 struct drbd_bitmap *bitmap; 962 unsigned long bm_resync_fo; /* bit offset for drbd_bm_find_next */ 963 964 /* Used to track operations of resync... */ 965 struct lru_cache *resync; 966 /* Number of locked elements in resync LRU */ 967 unsigned int resync_locked; 968 /* resync extent number waiting for application requests */ 969 unsigned int resync_wenr; 970 971 int open_cnt; 972 u64 *p_uuid; 973 struct drbd_epoch *current_epoch; 974 spinlock_t epoch_lock; 975 unsigned int epochs; 976 enum write_ordering_e write_ordering; 977 struct list_head active_ee; /* IO in progress */ 978 struct list_head sync_ee; /* IO in progress */ 979 struct list_head done_ee; /* send ack */ 980 struct list_head read_ee; /* IO in progress */ 981 struct list_head net_ee; /* zero-copy network send in progress */ 982 struct hlist_head *ee_hash; /* is proteced by req_lock! */ 983 unsigned int ee_hash_s; 984 985 /* this one is protected by ee_lock, single thread */ 986 struct drbd_epoch_entry *last_write_w_barrier; 987 988 int next_barrier_nr; 989 struct hlist_head *app_reads_hash; /* is proteced by req_lock */ 990 struct list_head resync_reads; 991 atomic_t pp_in_use; 992 wait_queue_head_t ee_wait; 993 struct page *md_io_page; /* one page buffer for md_io */ 994 struct page *md_io_tmpp; /* for logical_block_size != 512 */ 995 struct mutex md_io_mutex; /* protects the md_io_buffer */ 996 spinlock_t al_lock; 997 wait_queue_head_t al_wait; 998 struct lru_cache *act_log; /* activity log */ 999 unsigned int al_tr_number; 1000 int al_tr_cycle; 1001 int al_tr_pos; /* position of the next transaction in the journal */ 1002 struct crypto_hash *cram_hmac_tfm; 1003 struct crypto_hash *integrity_w_tfm; /* to be used by the worker thread */ 1004 struct crypto_hash *integrity_r_tfm; /* to be used by the receiver thread */ 1005 void *int_dig_out; 1006 void *int_dig_in; 1007 void *int_dig_vv; 1008 wait_queue_head_t seq_wait; 1009 atomic_t packet_seq; 1010 unsigned int peer_seq; 1011 spinlock_t peer_seq_lock; 1012 unsigned int minor; 1013 unsigned long comm_bm_set; /* communicated number of set bits. */ 1014 cpumask_var_t cpu_mask; 1015 struct bm_io_work bm_io_work; 1016 u64 ed_uuid; /* UUID of the exposed data */ 1017 struct mutex state_mutex; 1018 char congestion_reason; /* Why we where congested... */ 1019 }; 1020 1021 static inline struct drbd_conf *minor_to_mdev(unsigned int minor) 1022 { 1023 struct drbd_conf *mdev; 1024 1025 mdev = minor < minor_count ? minor_table[minor] : NULL; 1026 1027 return mdev; 1028 } 1029 1030 static inline unsigned int mdev_to_minor(struct drbd_conf *mdev) 1031 { 1032 return mdev->minor; 1033 } 1034 1035 /* returns 1 if it was successfull, 1036 * returns 0 if there was no data socket. 1037 * so wherever you are going to use the data.socket, e.g. do 1038 * if (!drbd_get_data_sock(mdev)) 1039 * return 0; 1040 * CODE(); 1041 * drbd_put_data_sock(mdev); 1042 */ 1043 static inline int drbd_get_data_sock(struct drbd_conf *mdev) 1044 { 1045 mutex_lock(&mdev->data.mutex); 1046 /* drbd_disconnect() could have called drbd_free_sock() 1047 * while we were waiting in down()... */ 1048 if (unlikely(mdev->data.socket == NULL)) { 1049 mutex_unlock(&mdev->data.mutex); 1050 return 0; 1051 } 1052 return 1; 1053 } 1054 1055 static inline void drbd_put_data_sock(struct drbd_conf *mdev) 1056 { 1057 mutex_unlock(&mdev->data.mutex); 1058 } 1059 1060 /* 1061 * function declarations 1062 *************************/ 1063 1064 /* drbd_main.c */ 1065 1066 enum chg_state_flags { 1067 CS_HARD = 1, 1068 CS_VERBOSE = 2, 1069 CS_WAIT_COMPLETE = 4, 1070 CS_SERIALIZE = 8, 1071 CS_ORDERED = CS_WAIT_COMPLETE + CS_SERIALIZE, 1072 }; 1073 1074 extern void drbd_init_set_defaults(struct drbd_conf *mdev); 1075 extern int drbd_change_state(struct drbd_conf *mdev, enum chg_state_flags f, 1076 union drbd_state mask, union drbd_state val); 1077 extern void drbd_force_state(struct drbd_conf *, union drbd_state, 1078 union drbd_state); 1079 extern int _drbd_request_state(struct drbd_conf *, union drbd_state, 1080 union drbd_state, enum chg_state_flags); 1081 extern int __drbd_set_state(struct drbd_conf *, union drbd_state, 1082 enum chg_state_flags, struct completion *done); 1083 extern void print_st_err(struct drbd_conf *, union drbd_state, 1084 union drbd_state, int); 1085 extern int drbd_thread_start(struct drbd_thread *thi); 1086 extern void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait); 1087 #ifdef CONFIG_SMP 1088 extern void drbd_thread_current_set_cpu(struct drbd_conf *mdev); 1089 extern void drbd_calc_cpu_mask(struct drbd_conf *mdev); 1090 #else 1091 #define drbd_thread_current_set_cpu(A) ({}) 1092 #define drbd_calc_cpu_mask(A) ({}) 1093 #endif 1094 extern void drbd_free_resources(struct drbd_conf *mdev); 1095 extern void tl_release(struct drbd_conf *mdev, unsigned int barrier_nr, 1096 unsigned int set_size); 1097 extern void tl_clear(struct drbd_conf *mdev); 1098 extern void _tl_add_barrier(struct drbd_conf *, struct drbd_tl_epoch *); 1099 extern void drbd_free_sock(struct drbd_conf *mdev); 1100 extern int drbd_send(struct drbd_conf *mdev, struct socket *sock, 1101 void *buf, size_t size, unsigned msg_flags); 1102 extern int drbd_send_protocol(struct drbd_conf *mdev); 1103 extern int drbd_send_uuids(struct drbd_conf *mdev); 1104 extern int drbd_send_uuids_skip_initial_sync(struct drbd_conf *mdev); 1105 extern int drbd_send_sync_uuid(struct drbd_conf *mdev, u64 val); 1106 extern int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply); 1107 extern int _drbd_send_state(struct drbd_conf *mdev); 1108 extern int drbd_send_state(struct drbd_conf *mdev); 1109 extern int _drbd_send_cmd(struct drbd_conf *mdev, struct socket *sock, 1110 enum drbd_packets cmd, struct p_header *h, 1111 size_t size, unsigned msg_flags); 1112 #define USE_DATA_SOCKET 1 1113 #define USE_META_SOCKET 0 1114 extern int drbd_send_cmd(struct drbd_conf *mdev, int use_data_socket, 1115 enum drbd_packets cmd, struct p_header *h, 1116 size_t size); 1117 extern int drbd_send_cmd2(struct drbd_conf *mdev, enum drbd_packets cmd, 1118 char *data, size_t size); 1119 extern int drbd_send_sync_param(struct drbd_conf *mdev, struct syncer_conf *sc); 1120 extern int drbd_send_b_ack(struct drbd_conf *mdev, u32 barrier_nr, 1121 u32 set_size); 1122 extern int drbd_send_ack(struct drbd_conf *mdev, enum drbd_packets cmd, 1123 struct drbd_epoch_entry *e); 1124 extern int drbd_send_ack_rp(struct drbd_conf *mdev, enum drbd_packets cmd, 1125 struct p_block_req *rp); 1126 extern int drbd_send_ack_dp(struct drbd_conf *mdev, enum drbd_packets cmd, 1127 struct p_data *dp); 1128 extern int drbd_send_ack_ex(struct drbd_conf *mdev, enum drbd_packets cmd, 1129 sector_t sector, int blksize, u64 block_id); 1130 extern int drbd_send_block(struct drbd_conf *mdev, enum drbd_packets cmd, 1131 struct drbd_epoch_entry *e); 1132 extern int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req); 1133 extern int _drbd_send_barrier(struct drbd_conf *mdev, 1134 struct drbd_tl_epoch *barrier); 1135 extern int drbd_send_drequest(struct drbd_conf *mdev, int cmd, 1136 sector_t sector, int size, u64 block_id); 1137 extern int drbd_send_drequest_csum(struct drbd_conf *mdev, 1138 sector_t sector,int size, 1139 void *digest, int digest_size, 1140 enum drbd_packets cmd); 1141 extern int drbd_send_ov_request(struct drbd_conf *mdev,sector_t sector,int size); 1142 1143 extern int drbd_send_bitmap(struct drbd_conf *mdev); 1144 extern int _drbd_send_bitmap(struct drbd_conf *mdev); 1145 extern int drbd_send_sr_reply(struct drbd_conf *mdev, int retcode); 1146 extern void drbd_free_bc(struct drbd_backing_dev *ldev); 1147 extern void drbd_mdev_cleanup(struct drbd_conf *mdev); 1148 1149 /* drbd_meta-data.c (still in drbd_main.c) */ 1150 extern void drbd_md_sync(struct drbd_conf *mdev); 1151 extern int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev); 1152 /* maybe define them below as inline? */ 1153 extern void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local); 1154 extern void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local); 1155 extern void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local); 1156 extern void _drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local); 1157 extern void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local); 1158 extern void drbd_md_set_flag(struct drbd_conf *mdev, int flags) __must_hold(local); 1159 extern void drbd_md_clear_flag(struct drbd_conf *mdev, int flags)__must_hold(local); 1160 extern int drbd_md_test_flag(struct drbd_backing_dev *, int); 1161 extern void drbd_md_mark_dirty(struct drbd_conf *mdev); 1162 extern void drbd_queue_bitmap_io(struct drbd_conf *mdev, 1163 int (*io_fn)(struct drbd_conf *), 1164 void (*done)(struct drbd_conf *, int), 1165 char *why); 1166 extern int drbd_bmio_set_n_write(struct drbd_conf *mdev); 1167 extern int drbd_bmio_clear_n_write(struct drbd_conf *mdev); 1168 extern int drbd_bitmap_io(struct drbd_conf *mdev, int (*io_fn)(struct drbd_conf *), char *why); 1169 1170 1171 /* Meta data layout 1172 We reserve a 128MB Block (4k aligned) 1173 * either at the end of the backing device 1174 * or on a seperate meta data device. */ 1175 1176 #define MD_RESERVED_SECT (128LU << 11) /* 128 MB, unit sectors */ 1177 /* The following numbers are sectors */ 1178 #define MD_AL_OFFSET 8 /* 8 Sectors after start of meta area */ 1179 #define MD_AL_MAX_SIZE 64 /* = 32 kb LOG ~ 3776 extents ~ 14 GB Storage */ 1180 /* Allows up to about 3.8TB */ 1181 #define MD_BM_OFFSET (MD_AL_OFFSET + MD_AL_MAX_SIZE) 1182 1183 /* Since the smalles IO unit is usually 512 byte */ 1184 #define MD_SECTOR_SHIFT 9 1185 #define MD_SECTOR_SIZE (1<<MD_SECTOR_SHIFT) 1186 1187 /* activity log */ 1188 #define AL_EXTENTS_PT ((MD_SECTOR_SIZE-12)/8-1) /* 61 ; Extents per 512B sector */ 1189 #define AL_EXTENT_SHIFT 22 /* One extent represents 4M Storage */ 1190 #define AL_EXTENT_SIZE (1<<AL_EXTENT_SHIFT) 1191 1192 #if BITS_PER_LONG == 32 1193 #define LN2_BPL 5 1194 #define cpu_to_lel(A) cpu_to_le32(A) 1195 #define lel_to_cpu(A) le32_to_cpu(A) 1196 #elif BITS_PER_LONG == 64 1197 #define LN2_BPL 6 1198 #define cpu_to_lel(A) cpu_to_le64(A) 1199 #define lel_to_cpu(A) le64_to_cpu(A) 1200 #else 1201 #error "LN2 of BITS_PER_LONG unknown!" 1202 #endif 1203 1204 /* resync bitmap */ 1205 /* 16MB sized 'bitmap extent' to track syncer usage */ 1206 struct bm_extent { 1207 int rs_left; /* number of bits set (out of sync) in this extent. */ 1208 int rs_failed; /* number of failed resync requests in this extent. */ 1209 unsigned long flags; 1210 struct lc_element lce; 1211 }; 1212 1213 #define BME_NO_WRITES 0 /* bm_extent.flags: no more requests on this one! */ 1214 #define BME_LOCKED 1 /* bm_extent.flags: syncer active on this one. */ 1215 1216 /* drbd_bitmap.c */ 1217 /* 1218 * We need to store one bit for a block. 1219 * Example: 1GB disk @ 4096 byte blocks ==> we need 32 KB bitmap. 1220 * Bit 0 ==> local node thinks this block is binary identical on both nodes 1221 * Bit 1 ==> local node thinks this block needs to be synced. 1222 */ 1223 1224 #define BM_BLOCK_SHIFT 12 /* 4k per bit */ 1225 #define BM_BLOCK_SIZE (1<<BM_BLOCK_SHIFT) 1226 /* (9+3) : 512 bytes @ 8 bits; representing 16M storage 1227 * per sector of on disk bitmap */ 1228 #define BM_EXT_SHIFT (BM_BLOCK_SHIFT + MD_SECTOR_SHIFT + 3) /* = 24 */ 1229 #define BM_EXT_SIZE (1<<BM_EXT_SHIFT) 1230 1231 #if (BM_EXT_SHIFT != 24) || (BM_BLOCK_SHIFT != 12) 1232 #error "HAVE YOU FIXED drbdmeta AS WELL??" 1233 #endif 1234 1235 /* thus many _storage_ sectors are described by one bit */ 1236 #define BM_SECT_TO_BIT(x) ((x)>>(BM_BLOCK_SHIFT-9)) 1237 #define BM_BIT_TO_SECT(x) ((sector_t)(x)<<(BM_BLOCK_SHIFT-9)) 1238 #define BM_SECT_PER_BIT BM_BIT_TO_SECT(1) 1239 1240 /* bit to represented kilo byte conversion */ 1241 #define Bit2KB(bits) ((bits)<<(BM_BLOCK_SHIFT-10)) 1242 1243 /* in which _bitmap_ extent (resp. sector) the bit for a certain 1244 * _storage_ sector is located in */ 1245 #define BM_SECT_TO_EXT(x) ((x)>>(BM_EXT_SHIFT-9)) 1246 1247 /* how much _storage_ sectors we have per bitmap sector */ 1248 #define BM_EXT_TO_SECT(x) ((sector_t)(x) << (BM_EXT_SHIFT-9)) 1249 #define BM_SECT_PER_EXT BM_EXT_TO_SECT(1) 1250 1251 /* in one sector of the bitmap, we have this many activity_log extents. */ 1252 #define AL_EXT_PER_BM_SECT (1 << (BM_EXT_SHIFT - AL_EXTENT_SHIFT)) 1253 #define BM_WORDS_PER_AL_EXT (1 << (AL_EXTENT_SHIFT-BM_BLOCK_SHIFT-LN2_BPL)) 1254 1255 #define BM_BLOCKS_PER_BM_EXT_B (BM_EXT_SHIFT - BM_BLOCK_SHIFT) 1256 #define BM_BLOCKS_PER_BM_EXT_MASK ((1<<BM_BLOCKS_PER_BM_EXT_B) - 1) 1257 1258 /* the extent in "PER_EXTENT" below is an activity log extent 1259 * we need that many (long words/bytes) to store the bitmap 1260 * of one AL_EXTENT_SIZE chunk of storage. 1261 * we can store the bitmap for that many AL_EXTENTS within 1262 * one sector of the _on_disk_ bitmap: 1263 * bit 0 bit 37 bit 38 bit (512*8)-1 1264 * ...|........|........|.. // ..|........| 1265 * sect. 0 `296 `304 ^(512*8*8)-1 1266 * 1267 #define BM_WORDS_PER_EXT ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / BITS_PER_LONG ) 1268 #define BM_BYTES_PER_EXT ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / 8 ) // 128 1269 #define BM_EXT_PER_SECT ( 512 / BM_BYTES_PER_EXTENT ) // 4 1270 */ 1271 1272 #define DRBD_MAX_SECTORS_32 (0xffffffffLU) 1273 #define DRBD_MAX_SECTORS_BM \ 1274 ((MD_RESERVED_SECT - MD_BM_OFFSET) * (1LL<<(BM_EXT_SHIFT-9))) 1275 #if DRBD_MAX_SECTORS_BM < DRBD_MAX_SECTORS_32 1276 #define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_BM 1277 #define DRBD_MAX_SECTORS_FLEX DRBD_MAX_SECTORS_BM 1278 #elif !defined(CONFIG_LBD) && BITS_PER_LONG == 32 1279 #define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_32 1280 #define DRBD_MAX_SECTORS_FLEX DRBD_MAX_SECTORS_32 1281 #else 1282 #define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_BM 1283 /* 16 TB in units of sectors */ 1284 #if BITS_PER_LONG == 32 1285 /* adjust by one page worth of bitmap, 1286 * so we won't wrap around in drbd_bm_find_next_bit. 1287 * you should use 64bit OS for that much storage, anyways. */ 1288 #define DRBD_MAX_SECTORS_FLEX BM_BIT_TO_SECT(0xffff7fff) 1289 #else 1290 #define DRBD_MAX_SECTORS_FLEX BM_BIT_TO_SECT(0x1LU << 32) 1291 #endif 1292 #endif 1293 1294 /* Sector shift value for the "hash" functions of tl_hash and ee_hash tables. 1295 * With a value of 6 all IO in one 32K block make it to the same slot of the 1296 * hash table. */ 1297 #define HT_SHIFT 6 1298 #define DRBD_MAX_SEGMENT_SIZE (1U<<(9+HT_SHIFT)) 1299 1300 /* Number of elements in the app_reads_hash */ 1301 #define APP_R_HSIZE 15 1302 1303 extern int drbd_bm_init(struct drbd_conf *mdev); 1304 extern int drbd_bm_resize(struct drbd_conf *mdev, sector_t sectors); 1305 extern void drbd_bm_cleanup(struct drbd_conf *mdev); 1306 extern void drbd_bm_set_all(struct drbd_conf *mdev); 1307 extern void drbd_bm_clear_all(struct drbd_conf *mdev); 1308 extern int drbd_bm_set_bits( 1309 struct drbd_conf *mdev, unsigned long s, unsigned long e); 1310 extern int drbd_bm_clear_bits( 1311 struct drbd_conf *mdev, unsigned long s, unsigned long e); 1312 /* bm_set_bits variant for use while holding drbd_bm_lock */ 1313 extern void _drbd_bm_set_bits(struct drbd_conf *mdev, 1314 const unsigned long s, const unsigned long e); 1315 extern int drbd_bm_test_bit(struct drbd_conf *mdev, unsigned long bitnr); 1316 extern int drbd_bm_e_weight(struct drbd_conf *mdev, unsigned long enr); 1317 extern int drbd_bm_write_sect(struct drbd_conf *mdev, unsigned long enr) __must_hold(local); 1318 extern int drbd_bm_read(struct drbd_conf *mdev) __must_hold(local); 1319 extern int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local); 1320 extern unsigned long drbd_bm_ALe_set_all(struct drbd_conf *mdev, 1321 unsigned long al_enr); 1322 extern size_t drbd_bm_words(struct drbd_conf *mdev); 1323 extern unsigned long drbd_bm_bits(struct drbd_conf *mdev); 1324 extern sector_t drbd_bm_capacity(struct drbd_conf *mdev); 1325 extern unsigned long drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo); 1326 /* bm_find_next variants for use while you hold drbd_bm_lock() */ 1327 extern unsigned long _drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo); 1328 extern unsigned long _drbd_bm_find_next_zero(struct drbd_conf *mdev, unsigned long bm_fo); 1329 extern unsigned long drbd_bm_total_weight(struct drbd_conf *mdev); 1330 extern int drbd_bm_rs_done(struct drbd_conf *mdev); 1331 /* for receive_bitmap */ 1332 extern void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset, 1333 size_t number, unsigned long *buffer); 1334 /* for _drbd_send_bitmap and drbd_bm_write_sect */ 1335 extern void drbd_bm_get_lel(struct drbd_conf *mdev, size_t offset, 1336 size_t number, unsigned long *buffer); 1337 1338 extern void drbd_bm_lock(struct drbd_conf *mdev, char *why); 1339 extern void drbd_bm_unlock(struct drbd_conf *mdev); 1340 1341 extern int drbd_bm_count_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e); 1342 /* drbd_main.c */ 1343 1344 extern struct kmem_cache *drbd_request_cache; 1345 extern struct kmem_cache *drbd_ee_cache; /* epoch entries */ 1346 extern struct kmem_cache *drbd_bm_ext_cache; /* bitmap extents */ 1347 extern struct kmem_cache *drbd_al_ext_cache; /* activity log extents */ 1348 extern mempool_t *drbd_request_mempool; 1349 extern mempool_t *drbd_ee_mempool; 1350 1351 extern struct page *drbd_pp_pool; /* drbd's page pool */ 1352 extern spinlock_t drbd_pp_lock; 1353 extern int drbd_pp_vacant; 1354 extern wait_queue_head_t drbd_pp_wait; 1355 1356 extern rwlock_t global_state_lock; 1357 1358 extern struct drbd_conf *drbd_new_device(unsigned int minor); 1359 extern void drbd_free_mdev(struct drbd_conf *mdev); 1360 1361 extern int proc_details; 1362 1363 /* drbd_req */ 1364 extern int drbd_make_request_26(struct request_queue *q, struct bio *bio); 1365 extern int drbd_read_remote(struct drbd_conf *mdev, struct drbd_request *req); 1366 extern int drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct bio_vec *bvec); 1367 extern int is_valid_ar_handle(struct drbd_request *, sector_t); 1368 1369 1370 /* drbd_nl.c */ 1371 extern void drbd_suspend_io(struct drbd_conf *mdev); 1372 extern void drbd_resume_io(struct drbd_conf *mdev); 1373 extern char *ppsize(char *buf, unsigned long long size); 1374 extern sector_t drbd_new_dev_size(struct drbd_conf *, 1375 struct drbd_backing_dev *); 1376 enum determine_dev_size { dev_size_error = -1, unchanged = 0, shrunk = 1, grew = 2 }; 1377 extern enum determine_dev_size drbd_determin_dev_size(struct drbd_conf *) __must_hold(local); 1378 extern void resync_after_online_grow(struct drbd_conf *); 1379 extern void drbd_setup_queue_param(struct drbd_conf *mdev, unsigned int) __must_hold(local); 1380 extern int drbd_set_role(struct drbd_conf *mdev, enum drbd_role new_role, 1381 int force); 1382 enum drbd_disk_state drbd_try_outdate_peer(struct drbd_conf *mdev); 1383 extern int drbd_khelper(struct drbd_conf *mdev, char *cmd); 1384 1385 /* drbd_worker.c */ 1386 extern int drbd_worker(struct drbd_thread *thi); 1387 extern int drbd_alter_sa(struct drbd_conf *mdev, int na); 1388 extern void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side); 1389 extern void resume_next_sg(struct drbd_conf *mdev); 1390 extern void suspend_other_sg(struct drbd_conf *mdev); 1391 extern int drbd_resync_finished(struct drbd_conf *mdev); 1392 /* maybe rather drbd_main.c ? */ 1393 extern int drbd_md_sync_page_io(struct drbd_conf *mdev, 1394 struct drbd_backing_dev *bdev, sector_t sector, int rw); 1395 extern void drbd_ov_oos_found(struct drbd_conf*, sector_t, int); 1396 1397 static inline void ov_oos_print(struct drbd_conf *mdev) 1398 { 1399 if (mdev->ov_last_oos_size) { 1400 dev_err(DEV, "Out of sync: start=%llu, size=%lu (sectors)\n", 1401 (unsigned long long)mdev->ov_last_oos_start, 1402 (unsigned long)mdev->ov_last_oos_size); 1403 } 1404 mdev->ov_last_oos_size=0; 1405 } 1406 1407 1408 extern void drbd_csum(struct drbd_conf *, struct crypto_hash *, struct bio *, void *); 1409 /* worker callbacks */ 1410 extern int w_req_cancel_conflict(struct drbd_conf *, struct drbd_work *, int); 1411 extern int w_read_retry_remote(struct drbd_conf *, struct drbd_work *, int); 1412 extern int w_e_end_data_req(struct drbd_conf *, struct drbd_work *, int); 1413 extern int w_e_end_rsdata_req(struct drbd_conf *, struct drbd_work *, int); 1414 extern int w_e_end_csum_rs_req(struct drbd_conf *, struct drbd_work *, int); 1415 extern int w_e_end_ov_reply(struct drbd_conf *, struct drbd_work *, int); 1416 extern int w_e_end_ov_req(struct drbd_conf *, struct drbd_work *, int); 1417 extern int w_ov_finished(struct drbd_conf *, struct drbd_work *, int); 1418 extern int w_resync_inactive(struct drbd_conf *, struct drbd_work *, int); 1419 extern int w_resume_next_sg(struct drbd_conf *, struct drbd_work *, int); 1420 extern int w_io_error(struct drbd_conf *, struct drbd_work *, int); 1421 extern int w_send_write_hint(struct drbd_conf *, struct drbd_work *, int); 1422 extern int w_make_resync_request(struct drbd_conf *, struct drbd_work *, int); 1423 extern int w_send_dblock(struct drbd_conf *, struct drbd_work *, int); 1424 extern int w_send_barrier(struct drbd_conf *, struct drbd_work *, int); 1425 extern int w_send_read_req(struct drbd_conf *, struct drbd_work *, int); 1426 extern int w_prev_work_done(struct drbd_conf *, struct drbd_work *, int); 1427 extern int w_e_reissue(struct drbd_conf *, struct drbd_work *, int); 1428 1429 extern void resync_timer_fn(unsigned long data); 1430 1431 /* drbd_receiver.c */ 1432 extern int drbd_release_ee(struct drbd_conf *mdev, struct list_head *list); 1433 extern struct drbd_epoch_entry *drbd_alloc_ee(struct drbd_conf *mdev, 1434 u64 id, 1435 sector_t sector, 1436 unsigned int data_size, 1437 gfp_t gfp_mask) __must_hold(local); 1438 extern void drbd_free_ee(struct drbd_conf *mdev, struct drbd_epoch_entry *e); 1439 extern void drbd_wait_ee_list_empty(struct drbd_conf *mdev, 1440 struct list_head *head); 1441 extern void _drbd_wait_ee_list_empty(struct drbd_conf *mdev, 1442 struct list_head *head); 1443 extern void drbd_set_recv_tcq(struct drbd_conf *mdev, int tcq_enabled); 1444 extern void _drbd_clear_done_ee(struct drbd_conf *mdev, struct list_head *to_be_freed); 1445 extern void drbd_flush_workqueue(struct drbd_conf *mdev); 1446 1447 /* yes, there is kernel_setsockopt, but only since 2.6.18. we don't need to 1448 * mess with get_fs/set_fs, we know we are KERNEL_DS always. */ 1449 static inline int drbd_setsockopt(struct socket *sock, int level, int optname, 1450 char __user *optval, int optlen) 1451 { 1452 int err; 1453 if (level == SOL_SOCKET) 1454 err = sock_setsockopt(sock, level, optname, optval, optlen); 1455 else 1456 err = sock->ops->setsockopt(sock, level, optname, optval, 1457 optlen); 1458 return err; 1459 } 1460 1461 static inline void drbd_tcp_cork(struct socket *sock) 1462 { 1463 int __user val = 1; 1464 (void) drbd_setsockopt(sock, SOL_TCP, TCP_CORK, 1465 (char __user *)&val, sizeof(val)); 1466 } 1467 1468 static inline void drbd_tcp_uncork(struct socket *sock) 1469 { 1470 int __user val = 0; 1471 (void) drbd_setsockopt(sock, SOL_TCP, TCP_CORK, 1472 (char __user *)&val, sizeof(val)); 1473 } 1474 1475 static inline void drbd_tcp_nodelay(struct socket *sock) 1476 { 1477 int __user val = 1; 1478 (void) drbd_setsockopt(sock, SOL_TCP, TCP_NODELAY, 1479 (char __user *)&val, sizeof(val)); 1480 } 1481 1482 static inline void drbd_tcp_quickack(struct socket *sock) 1483 { 1484 int __user val = 1; 1485 (void) drbd_setsockopt(sock, SOL_TCP, TCP_QUICKACK, 1486 (char __user *)&val, sizeof(val)); 1487 } 1488 1489 void drbd_bump_write_ordering(struct drbd_conf *mdev, enum write_ordering_e wo); 1490 1491 /* drbd_proc.c */ 1492 extern struct proc_dir_entry *drbd_proc; 1493 extern struct file_operations drbd_proc_fops; 1494 extern const char *drbd_conn_str(enum drbd_conns s); 1495 extern const char *drbd_role_str(enum drbd_role s); 1496 1497 /* drbd_actlog.c */ 1498 extern void drbd_al_begin_io(struct drbd_conf *mdev, sector_t sector); 1499 extern void drbd_al_complete_io(struct drbd_conf *mdev, sector_t sector); 1500 extern void drbd_rs_complete_io(struct drbd_conf *mdev, sector_t sector); 1501 extern int drbd_rs_begin_io(struct drbd_conf *mdev, sector_t sector); 1502 extern int drbd_try_rs_begin_io(struct drbd_conf *mdev, sector_t sector); 1503 extern void drbd_rs_cancel_all(struct drbd_conf *mdev); 1504 extern int drbd_rs_del_all(struct drbd_conf *mdev); 1505 extern void drbd_rs_failed_io(struct drbd_conf *mdev, 1506 sector_t sector, int size); 1507 extern int drbd_al_read_log(struct drbd_conf *mdev, struct drbd_backing_dev *); 1508 extern void __drbd_set_in_sync(struct drbd_conf *mdev, sector_t sector, 1509 int size, const char *file, const unsigned int line); 1510 #define drbd_set_in_sync(mdev, sector, size) \ 1511 __drbd_set_in_sync(mdev, sector, size, __FILE__, __LINE__) 1512 extern void __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, 1513 int size, const char *file, const unsigned int line); 1514 #define drbd_set_out_of_sync(mdev, sector, size) \ 1515 __drbd_set_out_of_sync(mdev, sector, size, __FILE__, __LINE__) 1516 extern void drbd_al_apply_to_bm(struct drbd_conf *mdev); 1517 extern void drbd_al_to_on_disk_bm(struct drbd_conf *mdev); 1518 extern void drbd_al_shrink(struct drbd_conf *mdev); 1519 1520 1521 /* drbd_nl.c */ 1522 1523 void drbd_nl_cleanup(void); 1524 int __init drbd_nl_init(void); 1525 void drbd_bcast_state(struct drbd_conf *mdev, union drbd_state); 1526 void drbd_bcast_sync_progress(struct drbd_conf *mdev); 1527 void drbd_bcast_ee(struct drbd_conf *mdev, 1528 const char *reason, const int dgs, 1529 const char* seen_hash, const char* calc_hash, 1530 const struct drbd_epoch_entry* e); 1531 1532 1533 /** 1534 * DOC: DRBD State macros 1535 * 1536 * These macros are used to express state changes in easily readable form. 1537 * 1538 * The NS macros expand to a mask and a value, that can be bit ored onto the 1539 * current state as soon as the spinlock (req_lock) was taken. 1540 * 1541 * The _NS macros are used for state functions that get called with the 1542 * spinlock. These macros expand directly to the new state value. 1543 * 1544 * Besides the basic forms NS() and _NS() additional _?NS[23] are defined 1545 * to express state changes that affect more than one aspect of the state. 1546 * 1547 * E.g. NS2(conn, C_CONNECTED, peer, R_SECONDARY) 1548 * Means that the network connection was established and that the peer 1549 * is in secondary role. 1550 */ 1551 #define role_MASK R_MASK 1552 #define peer_MASK R_MASK 1553 #define disk_MASK D_MASK 1554 #define pdsk_MASK D_MASK 1555 #define conn_MASK C_MASK 1556 #define susp_MASK 1 1557 #define user_isp_MASK 1 1558 #define aftr_isp_MASK 1 1559 1560 #define NS(T, S) \ 1561 ({ union drbd_state mask; mask.i = 0; mask.T = T##_MASK; mask; }), \ 1562 ({ union drbd_state val; val.i = 0; val.T = (S); val; }) 1563 #define NS2(T1, S1, T2, S2) \ 1564 ({ union drbd_state mask; mask.i = 0; mask.T1 = T1##_MASK; \ 1565 mask.T2 = T2##_MASK; mask; }), \ 1566 ({ union drbd_state val; val.i = 0; val.T1 = (S1); \ 1567 val.T2 = (S2); val; }) 1568 #define NS3(T1, S1, T2, S2, T3, S3) \ 1569 ({ union drbd_state mask; mask.i = 0; mask.T1 = T1##_MASK; \ 1570 mask.T2 = T2##_MASK; mask.T3 = T3##_MASK; mask; }), \ 1571 ({ union drbd_state val; val.i = 0; val.T1 = (S1); \ 1572 val.T2 = (S2); val.T3 = (S3); val; }) 1573 1574 #define _NS(D, T, S) \ 1575 D, ({ union drbd_state __ns; __ns.i = D->state.i; __ns.T = (S); __ns; }) 1576 #define _NS2(D, T1, S1, T2, S2) \ 1577 D, ({ union drbd_state __ns; __ns.i = D->state.i; __ns.T1 = (S1); \ 1578 __ns.T2 = (S2); __ns; }) 1579 #define _NS3(D, T1, S1, T2, S2, T3, S3) \ 1580 D, ({ union drbd_state __ns; __ns.i = D->state.i; __ns.T1 = (S1); \ 1581 __ns.T2 = (S2); __ns.T3 = (S3); __ns; }) 1582 1583 /* 1584 * inline helper functions 1585 *************************/ 1586 1587 static inline void drbd_state_lock(struct drbd_conf *mdev) 1588 { 1589 wait_event(mdev->misc_wait, 1590 !test_and_set_bit(CLUSTER_ST_CHANGE, &mdev->flags)); 1591 } 1592 1593 static inline void drbd_state_unlock(struct drbd_conf *mdev) 1594 { 1595 clear_bit(CLUSTER_ST_CHANGE, &mdev->flags); 1596 wake_up(&mdev->misc_wait); 1597 } 1598 1599 static inline int _drbd_set_state(struct drbd_conf *mdev, 1600 union drbd_state ns, enum chg_state_flags flags, 1601 struct completion *done) 1602 { 1603 int rv; 1604 1605 read_lock(&global_state_lock); 1606 rv = __drbd_set_state(mdev, ns, flags, done); 1607 read_unlock(&global_state_lock); 1608 1609 return rv; 1610 } 1611 1612 /** 1613 * drbd_request_state() - Reqest a state change 1614 * @mdev: DRBD device. 1615 * @mask: mask of state bits to change. 1616 * @val: value of new state bits. 1617 * 1618 * This is the most graceful way of requesting a state change. It is verbose 1619 * quite verbose in case the state change is not possible, and all those 1620 * state changes are globally serialized. 1621 */ 1622 static inline int drbd_request_state(struct drbd_conf *mdev, 1623 union drbd_state mask, 1624 union drbd_state val) 1625 { 1626 return _drbd_request_state(mdev, mask, val, CS_VERBOSE + CS_ORDERED); 1627 } 1628 1629 #define __drbd_chk_io_error(m,f) __drbd_chk_io_error_(m,f, __func__) 1630 static inline void __drbd_chk_io_error_(struct drbd_conf *mdev, int forcedetach, const char *where) 1631 { 1632 switch (mdev->ldev->dc.on_io_error) { 1633 case EP_PASS_ON: 1634 if (!forcedetach) { 1635 if (printk_ratelimit()) 1636 dev_err(DEV, "Local IO failed in %s." 1637 "Passing error on...\n", where); 1638 break; 1639 } 1640 /* NOTE fall through to detach case if forcedetach set */ 1641 case EP_DETACH: 1642 case EP_CALL_HELPER: 1643 if (mdev->state.disk > D_FAILED) { 1644 _drbd_set_state(_NS(mdev, disk, D_FAILED), CS_HARD, NULL); 1645 dev_err(DEV, "Local IO failed in %s." 1646 "Detaching...\n", where); 1647 } 1648 break; 1649 } 1650 } 1651 1652 /** 1653 * drbd_chk_io_error: Handle the on_io_error setting, should be called from all io completion handlers 1654 * @mdev: DRBD device. 1655 * @error: Error code passed to the IO completion callback 1656 * @forcedetach: Force detach. I.e. the error happened while accessing the meta data 1657 * 1658 * See also drbd_main.c:after_state_ch() if (os.disk > D_FAILED && ns.disk == D_FAILED) 1659 */ 1660 #define drbd_chk_io_error(m,e,f) drbd_chk_io_error_(m,e,f, __func__) 1661 static inline void drbd_chk_io_error_(struct drbd_conf *mdev, 1662 int error, int forcedetach, const char *where) 1663 { 1664 if (error) { 1665 unsigned long flags; 1666 spin_lock_irqsave(&mdev->req_lock, flags); 1667 __drbd_chk_io_error_(mdev, forcedetach, where); 1668 spin_unlock_irqrestore(&mdev->req_lock, flags); 1669 } 1670 } 1671 1672 1673 /** 1674 * drbd_md_first_sector() - Returns the first sector number of the meta data area 1675 * @bdev: Meta data block device. 1676 * 1677 * BTW, for internal meta data, this happens to be the maximum capacity 1678 * we could agree upon with our peer node. 1679 */ 1680 static inline sector_t drbd_md_first_sector(struct drbd_backing_dev *bdev) 1681 { 1682 switch (bdev->dc.meta_dev_idx) { 1683 case DRBD_MD_INDEX_INTERNAL: 1684 case DRBD_MD_INDEX_FLEX_INT: 1685 return bdev->md.md_offset + bdev->md.bm_offset; 1686 case DRBD_MD_INDEX_FLEX_EXT: 1687 default: 1688 return bdev->md.md_offset; 1689 } 1690 } 1691 1692 /** 1693 * drbd_md_last_sector() - Return the last sector number of the meta data area 1694 * @bdev: Meta data block device. 1695 */ 1696 static inline sector_t drbd_md_last_sector(struct drbd_backing_dev *bdev) 1697 { 1698 switch (bdev->dc.meta_dev_idx) { 1699 case DRBD_MD_INDEX_INTERNAL: 1700 case DRBD_MD_INDEX_FLEX_INT: 1701 return bdev->md.md_offset + MD_AL_OFFSET - 1; 1702 case DRBD_MD_INDEX_FLEX_EXT: 1703 default: 1704 return bdev->md.md_offset + bdev->md.md_size_sect; 1705 } 1706 } 1707 1708 /* Returns the number of 512 byte sectors of the device */ 1709 static inline sector_t drbd_get_capacity(struct block_device *bdev) 1710 { 1711 /* return bdev ? get_capacity(bdev->bd_disk) : 0; */ 1712 return bdev ? bdev->bd_inode->i_size >> 9 : 0; 1713 } 1714 1715 /** 1716 * drbd_get_max_capacity() - Returns the capacity we announce to out peer 1717 * @bdev: Meta data block device. 1718 * 1719 * returns the capacity we announce to out peer. we clip ourselves at the 1720 * various MAX_SECTORS, because if we don't, current implementation will 1721 * oops sooner or later 1722 */ 1723 static inline sector_t drbd_get_max_capacity(struct drbd_backing_dev *bdev) 1724 { 1725 sector_t s; 1726 switch (bdev->dc.meta_dev_idx) { 1727 case DRBD_MD_INDEX_INTERNAL: 1728 case DRBD_MD_INDEX_FLEX_INT: 1729 s = drbd_get_capacity(bdev->backing_bdev) 1730 ? min_t(sector_t, DRBD_MAX_SECTORS_FLEX, 1731 drbd_md_first_sector(bdev)) 1732 : 0; 1733 break; 1734 case DRBD_MD_INDEX_FLEX_EXT: 1735 s = min_t(sector_t, DRBD_MAX_SECTORS_FLEX, 1736 drbd_get_capacity(bdev->backing_bdev)); 1737 /* clip at maximum size the meta device can support */ 1738 s = min_t(sector_t, s, 1739 BM_EXT_TO_SECT(bdev->md.md_size_sect 1740 - bdev->md.bm_offset)); 1741 break; 1742 default: 1743 s = min_t(sector_t, DRBD_MAX_SECTORS, 1744 drbd_get_capacity(bdev->backing_bdev)); 1745 } 1746 return s; 1747 } 1748 1749 /** 1750 * drbd_md_ss__() - Return the sector number of our meta data super block 1751 * @mdev: DRBD device. 1752 * @bdev: Meta data block device. 1753 */ 1754 static inline sector_t drbd_md_ss__(struct drbd_conf *mdev, 1755 struct drbd_backing_dev *bdev) 1756 { 1757 switch (bdev->dc.meta_dev_idx) { 1758 default: /* external, some index */ 1759 return MD_RESERVED_SECT * bdev->dc.meta_dev_idx; 1760 case DRBD_MD_INDEX_INTERNAL: 1761 /* with drbd08, internal meta data is always "flexible" */ 1762 case DRBD_MD_INDEX_FLEX_INT: 1763 /* sizeof(struct md_on_disk_07) == 4k 1764 * position: last 4k aligned block of 4k size */ 1765 if (!bdev->backing_bdev) { 1766 if (__ratelimit(&drbd_ratelimit_state)) { 1767 dev_err(DEV, "bdev->backing_bdev==NULL\n"); 1768 dump_stack(); 1769 } 1770 return 0; 1771 } 1772 return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL) 1773 - MD_AL_OFFSET; 1774 case DRBD_MD_INDEX_FLEX_EXT: 1775 return 0; 1776 } 1777 } 1778 1779 static inline void 1780 _drbd_queue_work(struct drbd_work_queue *q, struct drbd_work *w) 1781 { 1782 list_add_tail(&w->list, &q->q); 1783 up(&q->s); 1784 } 1785 1786 static inline void 1787 drbd_queue_work_front(struct drbd_work_queue *q, struct drbd_work *w) 1788 { 1789 unsigned long flags; 1790 spin_lock_irqsave(&q->q_lock, flags); 1791 list_add(&w->list, &q->q); 1792 up(&q->s); /* within the spinlock, 1793 see comment near end of drbd_worker() */ 1794 spin_unlock_irqrestore(&q->q_lock, flags); 1795 } 1796 1797 static inline void 1798 drbd_queue_work(struct drbd_work_queue *q, struct drbd_work *w) 1799 { 1800 unsigned long flags; 1801 spin_lock_irqsave(&q->q_lock, flags); 1802 list_add_tail(&w->list, &q->q); 1803 up(&q->s); /* within the spinlock, 1804 see comment near end of drbd_worker() */ 1805 spin_unlock_irqrestore(&q->q_lock, flags); 1806 } 1807 1808 static inline void wake_asender(struct drbd_conf *mdev) 1809 { 1810 if (test_bit(SIGNAL_ASENDER, &mdev->flags)) 1811 force_sig(DRBD_SIG, mdev->asender.task); 1812 } 1813 1814 static inline void request_ping(struct drbd_conf *mdev) 1815 { 1816 set_bit(SEND_PING, &mdev->flags); 1817 wake_asender(mdev); 1818 } 1819 1820 static inline int drbd_send_short_cmd(struct drbd_conf *mdev, 1821 enum drbd_packets cmd) 1822 { 1823 struct p_header h; 1824 return drbd_send_cmd(mdev, USE_DATA_SOCKET, cmd, &h, sizeof(h)); 1825 } 1826 1827 static inline int drbd_send_ping(struct drbd_conf *mdev) 1828 { 1829 struct p_header h; 1830 return drbd_send_cmd(mdev, USE_META_SOCKET, P_PING, &h, sizeof(h)); 1831 } 1832 1833 static inline int drbd_send_ping_ack(struct drbd_conf *mdev) 1834 { 1835 struct p_header h; 1836 return drbd_send_cmd(mdev, USE_META_SOCKET, P_PING_ACK, &h, sizeof(h)); 1837 } 1838 1839 static inline void drbd_thread_stop(struct drbd_thread *thi) 1840 { 1841 _drbd_thread_stop(thi, FALSE, TRUE); 1842 } 1843 1844 static inline void drbd_thread_stop_nowait(struct drbd_thread *thi) 1845 { 1846 _drbd_thread_stop(thi, FALSE, FALSE); 1847 } 1848 1849 static inline void drbd_thread_restart_nowait(struct drbd_thread *thi) 1850 { 1851 _drbd_thread_stop(thi, TRUE, FALSE); 1852 } 1853 1854 /* counts how many answer packets packets we expect from our peer, 1855 * for either explicit application requests, 1856 * or implicit barrier packets as necessary. 1857 * increased: 1858 * w_send_barrier 1859 * _req_mod(req, queue_for_net_write or queue_for_net_read); 1860 * it is much easier and equally valid to count what we queue for the 1861 * worker, even before it actually was queued or send. 1862 * (drbd_make_request_common; recovery path on read io-error) 1863 * decreased: 1864 * got_BarrierAck (respective tl_clear, tl_clear_barrier) 1865 * _req_mod(req, data_received) 1866 * [from receive_DataReply] 1867 * _req_mod(req, write_acked_by_peer or recv_acked_by_peer or neg_acked) 1868 * [from got_BlockAck (P_WRITE_ACK, P_RECV_ACK)] 1869 * for some reason it is NOT decreased in got_NegAck, 1870 * but in the resulting cleanup code from report_params. 1871 * we should try to remember the reason for that... 1872 * _req_mod(req, send_failed or send_canceled) 1873 * _req_mod(req, connection_lost_while_pending) 1874 * [from tl_clear_barrier] 1875 */ 1876 static inline void inc_ap_pending(struct drbd_conf *mdev) 1877 { 1878 atomic_inc(&mdev->ap_pending_cnt); 1879 } 1880 1881 #define ERR_IF_CNT_IS_NEGATIVE(which) \ 1882 if (atomic_read(&mdev->which) < 0) \ 1883 dev_err(DEV, "in %s:%d: " #which " = %d < 0 !\n", \ 1884 __func__ , __LINE__ , \ 1885 atomic_read(&mdev->which)) 1886 1887 #define dec_ap_pending(mdev) do { \ 1888 typecheck(struct drbd_conf *, mdev); \ 1889 if (atomic_dec_and_test(&mdev->ap_pending_cnt)) \ 1890 wake_up(&mdev->misc_wait); \ 1891 ERR_IF_CNT_IS_NEGATIVE(ap_pending_cnt); } while (0) 1892 1893 /* counts how many resync-related answers we still expect from the peer 1894 * increase decrease 1895 * C_SYNC_TARGET sends P_RS_DATA_REQUEST (and expects P_RS_DATA_REPLY) 1896 * C_SYNC_SOURCE sends P_RS_DATA_REPLY (and expects P_WRITE_ACK whith ID_SYNCER) 1897 * (or P_NEG_ACK with ID_SYNCER) 1898 */ 1899 static inline void inc_rs_pending(struct drbd_conf *mdev) 1900 { 1901 atomic_inc(&mdev->rs_pending_cnt); 1902 } 1903 1904 #define dec_rs_pending(mdev) do { \ 1905 typecheck(struct drbd_conf *, mdev); \ 1906 atomic_dec(&mdev->rs_pending_cnt); \ 1907 ERR_IF_CNT_IS_NEGATIVE(rs_pending_cnt); } while (0) 1908 1909 /* counts how many answers we still need to send to the peer. 1910 * increased on 1911 * receive_Data unless protocol A; 1912 * we need to send a P_RECV_ACK (proto B) 1913 * or P_WRITE_ACK (proto C) 1914 * receive_RSDataReply (recv_resync_read) we need to send a P_WRITE_ACK 1915 * receive_DataRequest (receive_RSDataRequest) we need to send back P_DATA 1916 * receive_Barrier_* we need to send a P_BARRIER_ACK 1917 */ 1918 static inline void inc_unacked(struct drbd_conf *mdev) 1919 { 1920 atomic_inc(&mdev->unacked_cnt); 1921 } 1922 1923 #define dec_unacked(mdev) do { \ 1924 typecheck(struct drbd_conf *, mdev); \ 1925 atomic_dec(&mdev->unacked_cnt); \ 1926 ERR_IF_CNT_IS_NEGATIVE(unacked_cnt); } while (0) 1927 1928 #define sub_unacked(mdev, n) do { \ 1929 typecheck(struct drbd_conf *, mdev); \ 1930 atomic_sub(n, &mdev->unacked_cnt); \ 1931 ERR_IF_CNT_IS_NEGATIVE(unacked_cnt); } while (0) 1932 1933 1934 static inline void put_net_conf(struct drbd_conf *mdev) 1935 { 1936 if (atomic_dec_and_test(&mdev->net_cnt)) 1937 wake_up(&mdev->misc_wait); 1938 } 1939 1940 /** 1941 * get_net_conf() - Increase ref count on mdev->net_conf; Returns 0 if nothing there 1942 * @mdev: DRBD device. 1943 * 1944 * You have to call put_net_conf() when finished working with mdev->net_conf. 1945 */ 1946 static inline int get_net_conf(struct drbd_conf *mdev) 1947 { 1948 int have_net_conf; 1949 1950 atomic_inc(&mdev->net_cnt); 1951 have_net_conf = mdev->state.conn >= C_UNCONNECTED; 1952 if (!have_net_conf) 1953 put_net_conf(mdev); 1954 return have_net_conf; 1955 } 1956 1957 /** 1958 * get_ldev() - Increase the ref count on mdev->ldev. Returns 0 if there is no ldev 1959 * @M: DRBD device. 1960 * 1961 * You have to call put_ldev() when finished working with mdev->ldev. 1962 */ 1963 #define get_ldev(M) __cond_lock(local, _get_ldev_if_state(M,D_INCONSISTENT)) 1964 #define get_ldev_if_state(M,MINS) __cond_lock(local, _get_ldev_if_state(M,MINS)) 1965 1966 static inline void put_ldev(struct drbd_conf *mdev) 1967 { 1968 __release(local); 1969 if (atomic_dec_and_test(&mdev->local_cnt)) 1970 wake_up(&mdev->misc_wait); 1971 D_ASSERT(atomic_read(&mdev->local_cnt) >= 0); 1972 } 1973 1974 #ifndef __CHECKER__ 1975 static inline int _get_ldev_if_state(struct drbd_conf *mdev, enum drbd_disk_state mins) 1976 { 1977 int io_allowed; 1978 1979 atomic_inc(&mdev->local_cnt); 1980 io_allowed = (mdev->state.disk >= mins); 1981 if (!io_allowed) 1982 put_ldev(mdev); 1983 return io_allowed; 1984 } 1985 #else 1986 extern int _get_ldev_if_state(struct drbd_conf *mdev, enum drbd_disk_state mins); 1987 #endif 1988 1989 /* you must have an "get_ldev" reference */ 1990 static inline void drbd_get_syncer_progress(struct drbd_conf *mdev, 1991 unsigned long *bits_left, unsigned int *per_mil_done) 1992 { 1993 /* 1994 * this is to break it at compile time when we change that 1995 * (we may feel 4TB maximum storage per drbd is not enough) 1996 */ 1997 typecheck(unsigned long, mdev->rs_total); 1998 1999 /* note: both rs_total and rs_left are in bits, i.e. in 2000 * units of BM_BLOCK_SIZE. 2001 * for the percentage, we don't care. */ 2002 2003 *bits_left = drbd_bm_total_weight(mdev) - mdev->rs_failed; 2004 /* >> 10 to prevent overflow, 2005 * +1 to prevent division by zero */ 2006 if (*bits_left > mdev->rs_total) { 2007 /* doh. maybe a logic bug somewhere. 2008 * may also be just a race condition 2009 * between this and a disconnect during sync. 2010 * for now, just prevent in-kernel buffer overflow. 2011 */ 2012 smp_rmb(); 2013 dev_warn(DEV, "cs:%s rs_left=%lu > rs_total=%lu (rs_failed %lu)\n", 2014 drbd_conn_str(mdev->state.conn), 2015 *bits_left, mdev->rs_total, mdev->rs_failed); 2016 *per_mil_done = 0; 2017 } else { 2018 /* make sure the calculation happens in long context */ 2019 unsigned long tmp = 1000UL - 2020 (*bits_left >> 10)*1000UL 2021 / ((mdev->rs_total >> 10) + 1UL); 2022 *per_mil_done = tmp; 2023 } 2024 } 2025 2026 2027 /* this throttles on-the-fly application requests 2028 * according to max_buffers settings; 2029 * maybe re-implement using semaphores? */ 2030 static inline int drbd_get_max_buffers(struct drbd_conf *mdev) 2031 { 2032 int mxb = 1000000; /* arbitrary limit on open requests */ 2033 if (get_net_conf(mdev)) { 2034 mxb = mdev->net_conf->max_buffers; 2035 put_net_conf(mdev); 2036 } 2037 return mxb; 2038 } 2039 2040 static inline int drbd_state_is_stable(union drbd_state s) 2041 { 2042 2043 /* DO NOT add a default clause, we want the compiler to warn us 2044 * for any newly introduced state we may have forgotten to add here */ 2045 2046 switch ((enum drbd_conns)s.conn) { 2047 /* new io only accepted when there is no connection, ... */ 2048 case C_STANDALONE: 2049 case C_WF_CONNECTION: 2050 /* ... or there is a well established connection. */ 2051 case C_CONNECTED: 2052 case C_SYNC_SOURCE: 2053 case C_SYNC_TARGET: 2054 case C_VERIFY_S: 2055 case C_VERIFY_T: 2056 case C_PAUSED_SYNC_S: 2057 case C_PAUSED_SYNC_T: 2058 /* maybe stable, look at the disk state */ 2059 break; 2060 2061 /* no new io accepted during tansitional states 2062 * like handshake or teardown */ 2063 case C_DISCONNECTING: 2064 case C_UNCONNECTED: 2065 case C_TIMEOUT: 2066 case C_BROKEN_PIPE: 2067 case C_NETWORK_FAILURE: 2068 case C_PROTOCOL_ERROR: 2069 case C_TEAR_DOWN: 2070 case C_WF_REPORT_PARAMS: 2071 case C_STARTING_SYNC_S: 2072 case C_STARTING_SYNC_T: 2073 case C_WF_BITMAP_S: 2074 case C_WF_BITMAP_T: 2075 case C_WF_SYNC_UUID: 2076 case C_MASK: 2077 /* not "stable" */ 2078 return 0; 2079 } 2080 2081 switch ((enum drbd_disk_state)s.disk) { 2082 case D_DISKLESS: 2083 case D_INCONSISTENT: 2084 case D_OUTDATED: 2085 case D_CONSISTENT: 2086 case D_UP_TO_DATE: 2087 /* disk state is stable as well. */ 2088 break; 2089 2090 /* no new io accepted during tansitional states */ 2091 case D_ATTACHING: 2092 case D_FAILED: 2093 case D_NEGOTIATING: 2094 case D_UNKNOWN: 2095 case D_MASK: 2096 /* not "stable" */ 2097 return 0; 2098 } 2099 2100 return 1; 2101 } 2102 2103 static inline int __inc_ap_bio_cond(struct drbd_conf *mdev) 2104 { 2105 int mxb = drbd_get_max_buffers(mdev); 2106 2107 if (mdev->state.susp) 2108 return 0; 2109 if (test_bit(SUSPEND_IO, &mdev->flags)) 2110 return 0; 2111 2112 /* to avoid potential deadlock or bitmap corruption, 2113 * in various places, we only allow new application io 2114 * to start during "stable" states. */ 2115 2116 /* no new io accepted when attaching or detaching the disk */ 2117 if (!drbd_state_is_stable(mdev->state)) 2118 return 0; 2119 2120 /* since some older kernels don't have atomic_add_unless, 2121 * and we are within the spinlock anyways, we have this workaround. */ 2122 if (atomic_read(&mdev->ap_bio_cnt) > mxb) 2123 return 0; 2124 if (test_bit(BITMAP_IO, &mdev->flags)) 2125 return 0; 2126 return 1; 2127 } 2128 2129 /* I'd like to use wait_event_lock_irq, 2130 * but I'm not sure when it got introduced, 2131 * and not sure when it has 3 or 4 arguments */ 2132 static inline void inc_ap_bio(struct drbd_conf *mdev, int one_or_two) 2133 { 2134 /* compare with after_state_ch, 2135 * os.conn != C_WF_BITMAP_S && ns.conn == C_WF_BITMAP_S */ 2136 DEFINE_WAIT(wait); 2137 2138 /* we wait here 2139 * as long as the device is suspended 2140 * until the bitmap is no longer on the fly during connection 2141 * handshake as long as we would exeed the max_buffer limit. 2142 * 2143 * to avoid races with the reconnect code, 2144 * we need to atomic_inc within the spinlock. */ 2145 2146 spin_lock_irq(&mdev->req_lock); 2147 while (!__inc_ap_bio_cond(mdev)) { 2148 prepare_to_wait(&mdev->misc_wait, &wait, TASK_UNINTERRUPTIBLE); 2149 spin_unlock_irq(&mdev->req_lock); 2150 schedule(); 2151 finish_wait(&mdev->misc_wait, &wait); 2152 spin_lock_irq(&mdev->req_lock); 2153 } 2154 atomic_add(one_or_two, &mdev->ap_bio_cnt); 2155 spin_unlock_irq(&mdev->req_lock); 2156 } 2157 2158 static inline void dec_ap_bio(struct drbd_conf *mdev) 2159 { 2160 int mxb = drbd_get_max_buffers(mdev); 2161 int ap_bio = atomic_dec_return(&mdev->ap_bio_cnt); 2162 2163 D_ASSERT(ap_bio >= 0); 2164 /* this currently does wake_up for every dec_ap_bio! 2165 * maybe rather introduce some type of hysteresis? 2166 * e.g. (ap_bio == mxb/2 || ap_bio == 0) ? */ 2167 if (ap_bio < mxb) 2168 wake_up(&mdev->misc_wait); 2169 if (ap_bio == 0 && test_bit(BITMAP_IO, &mdev->flags)) { 2170 if (!test_and_set_bit(BITMAP_IO_QUEUED, &mdev->flags)) 2171 drbd_queue_work(&mdev->data.work, &mdev->bm_io_work.w); 2172 } 2173 } 2174 2175 static inline void drbd_set_ed_uuid(struct drbd_conf *mdev, u64 val) 2176 { 2177 mdev->ed_uuid = val; 2178 } 2179 2180 static inline int seq_cmp(u32 a, u32 b) 2181 { 2182 /* we assume wrap around at 32bit. 2183 * for wrap around at 24bit (old atomic_t), 2184 * we'd have to 2185 * a <<= 8; b <<= 8; 2186 */ 2187 return (s32)(a) - (s32)(b); 2188 } 2189 #define seq_lt(a, b) (seq_cmp((a), (b)) < 0) 2190 #define seq_gt(a, b) (seq_cmp((a), (b)) > 0) 2191 #define seq_ge(a, b) (seq_cmp((a), (b)) >= 0) 2192 #define seq_le(a, b) (seq_cmp((a), (b)) <= 0) 2193 /* CAUTION: please no side effects in arguments! */ 2194 #define seq_max(a, b) ((u32)(seq_gt((a), (b)) ? (a) : (b))) 2195 2196 static inline void update_peer_seq(struct drbd_conf *mdev, unsigned int new_seq) 2197 { 2198 unsigned int m; 2199 spin_lock(&mdev->peer_seq_lock); 2200 m = seq_max(mdev->peer_seq, new_seq); 2201 mdev->peer_seq = m; 2202 spin_unlock(&mdev->peer_seq_lock); 2203 if (m == new_seq) 2204 wake_up(&mdev->seq_wait); 2205 } 2206 2207 static inline void drbd_update_congested(struct drbd_conf *mdev) 2208 { 2209 struct sock *sk = mdev->data.socket->sk; 2210 if (sk->sk_wmem_queued > sk->sk_sndbuf * 4 / 5) 2211 set_bit(NET_CONGESTED, &mdev->flags); 2212 } 2213 2214 static inline int drbd_queue_order_type(struct drbd_conf *mdev) 2215 { 2216 /* sorry, we currently have no working implementation 2217 * of distributed TCQ stuff */ 2218 #ifndef QUEUE_ORDERED_NONE 2219 #define QUEUE_ORDERED_NONE 0 2220 #endif 2221 return QUEUE_ORDERED_NONE; 2222 } 2223 2224 static inline void drbd_blk_run_queue(struct request_queue *q) 2225 { 2226 if (q && q->unplug_fn) 2227 q->unplug_fn(q); 2228 } 2229 2230 static inline void drbd_kick_lo(struct drbd_conf *mdev) 2231 { 2232 if (get_ldev(mdev)) { 2233 drbd_blk_run_queue(bdev_get_queue(mdev->ldev->backing_bdev)); 2234 put_ldev(mdev); 2235 } 2236 } 2237 2238 static inline void drbd_md_flush(struct drbd_conf *mdev) 2239 { 2240 int r; 2241 2242 if (test_bit(MD_NO_BARRIER, &mdev->flags)) 2243 return; 2244 2245 r = blkdev_issue_flush(mdev->ldev->md_bdev, NULL); 2246 if (r) { 2247 set_bit(MD_NO_BARRIER, &mdev->flags); 2248 dev_err(DEV, "meta data flush failed with status %d, disabling md-flushes\n", r); 2249 } 2250 } 2251 2252 #endif 2253