1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 md.h : kernel internal structure of the Linux MD driver 4 Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman 5 6 */ 7 8 #ifndef _MD_MD_H 9 #define _MD_MD_H 10 11 #include <linux/blkdev.h> 12 #include <linux/backing-dev.h> 13 #include <linux/badblocks.h> 14 #include <linux/kobject.h> 15 #include <linux/list.h> 16 #include <linux/mm.h> 17 #include <linux/mutex.h> 18 #include <linux/timer.h> 19 #include <linux/wait.h> 20 #include <linux/workqueue.h> 21 #include "md-cluster.h" 22 23 #define MaxSector (~(sector_t)0) 24 25 /* 26 * These flags should really be called "NO_RETRY" rather than 27 * "FAILFAST" because they don't make any promise about time lapse, 28 * only about the number of retries, which will be zero. 29 * REQ_FAILFAST_DRIVER is not included because 30 * Commit: 4a27446f3e39 ("[SCSI] modify scsi to handle new fail fast flags.") 31 * seems to suggest that the errors it avoids retrying should usually 32 * be retried. 33 */ 34 #define MD_FAILFAST (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT) 35 36 /* 37 * The struct embedded in rdev is used to serialize IO. 38 */ 39 struct serial_in_rdev { 40 struct rb_root_cached serial_rb; 41 spinlock_t serial_lock; 42 wait_queue_head_t serial_io_wait; 43 }; 44 45 /* 46 * MD's 'extended' device 47 */ 48 struct md_rdev { 49 struct list_head same_set; /* RAID devices within the same set */ 50 51 sector_t sectors; /* Device size (in 512bytes sectors) */ 52 struct mddev *mddev; /* RAID array if running */ 53 int last_events; /* IO event timestamp */ 54 55 /* 56 * If meta_bdev is non-NULL, it means that a separate device is 57 * being used to store the metadata (superblock/bitmap) which 58 * would otherwise be contained on the same device as the data (bdev). 59 */ 60 struct block_device *meta_bdev; 61 struct block_device *bdev; /* block device handle */ 62 63 struct page *sb_page, *bb_page; 64 int sb_loaded; 65 __u64 sb_events; 66 sector_t data_offset; /* start of data in array */ 67 sector_t new_data_offset;/* only relevant while reshaping */ 68 sector_t sb_start; /* offset of the super block (in 512byte sectors) */ 69 int sb_size; /* bytes in the superblock */ 70 int preferred_minor; /* autorun support */ 71 72 struct kobject kobj; 73 74 /* A device can be in one of three states based on two flags: 75 * Not working: faulty==1 in_sync==0 76 * Fully working: faulty==0 in_sync==1 77 * Working, but not 78 * in sync with array 79 * faulty==0 in_sync==0 80 * 81 * It can never have faulty==1, in_sync==1 82 * This reduces the burden of testing multiple flags in many cases 83 */ 84 85 unsigned long flags; /* bit set of 'enum flag_bits' bits. */ 86 wait_queue_head_t blocked_wait; 87 88 int desc_nr; /* descriptor index in the superblock */ 89 int raid_disk; /* role of device in array */ 90 int new_raid_disk; /* role that the device will have in 91 * the array after a level-change completes. 92 */ 93 int saved_raid_disk; /* role that device used to have in the 94 * array and could again if we did a partial 95 * resync from the bitmap 96 */ 97 union { 98 sector_t recovery_offset;/* If this device has been partially 99 * recovered, this is where we were 100 * up to. 101 */ 102 sector_t journal_tail; /* If this device is a journal device, 103 * this is the journal tail (journal 104 * recovery start point) 105 */ 106 }; 107 108 atomic_t nr_pending; /* number of pending requests. 109 * only maintained for arrays that 110 * support hot removal 111 */ 112 atomic_t read_errors; /* number of consecutive read errors that 113 * we have tried to ignore. 114 */ 115 time64_t last_read_error; /* monotonic time since our 116 * last read error 117 */ 118 atomic_t corrected_errors; /* number of corrected read errors, 119 * for reporting to userspace and storing 120 * in superblock. 121 */ 122 123 struct serial_in_rdev *serial; /* used for raid1 io serialization */ 124 125 struct kernfs_node *sysfs_state; /* handle for 'state' 126 * sysfs entry */ 127 /* handle for 'unacknowledged_bad_blocks' sysfs dentry */ 128 struct kernfs_node *sysfs_unack_badblocks; 129 /* handle for 'bad_blocks' sysfs dentry */ 130 struct kernfs_node *sysfs_badblocks; 131 struct badblocks badblocks; 132 133 struct { 134 short offset; /* Offset from superblock to start of PPL. 135 * Not used by external metadata. */ 136 unsigned int size; /* Size in sectors of the PPL space */ 137 sector_t sector; /* First sector of the PPL space */ 138 } ppl; 139 }; 140 enum flag_bits { 141 Faulty, /* device is known to have a fault */ 142 In_sync, /* device is in_sync with rest of array */ 143 Bitmap_sync, /* ..actually, not quite In_sync. Need a 144 * bitmap-based recovery to get fully in sync. 145 * The bit is only meaningful before device 146 * has been passed to pers->hot_add_disk. 147 */ 148 WriteMostly, /* Avoid reading if at all possible */ 149 AutoDetected, /* added by auto-detect */ 150 Blocked, /* An error occurred but has not yet 151 * been acknowledged by the metadata 152 * handler, so don't allow writes 153 * until it is cleared */ 154 WriteErrorSeen, /* A write error has been seen on this 155 * device 156 */ 157 FaultRecorded, /* Intermediate state for clearing 158 * Blocked. The Fault is/will-be 159 * recorded in the metadata, but that 160 * metadata hasn't been stored safely 161 * on disk yet. 162 */ 163 BlockedBadBlocks, /* A writer is blocked because they 164 * found an unacknowledged bad-block. 165 * This can safely be cleared at any 166 * time, and the writer will re-check. 167 * It may be set at any time, and at 168 * worst the writer will timeout and 169 * re-check. So setting it as 170 * accurately as possible is good, but 171 * not absolutely critical. 172 */ 173 WantReplacement, /* This device is a candidate to be 174 * hot-replaced, either because it has 175 * reported some faults, or because 176 * of explicit request. 177 */ 178 Replacement, /* This device is a replacement for 179 * a want_replacement device with same 180 * raid_disk number. 181 */ 182 Candidate, /* For clustered environments only: 183 * This device is seen locally but not 184 * by the whole cluster 185 */ 186 Journal, /* This device is used as journal for 187 * raid-5/6. 188 * Usually, this device should be faster 189 * than other devices in the array 190 */ 191 ClusterRemove, 192 RemoveSynchronized, /* synchronize_rcu() was called after 193 * this device was known to be faulty, 194 * so it is safe to remove without 195 * another synchronize_rcu() call. 196 */ 197 ExternalBbl, /* External metadata provides bad 198 * block management for a disk 199 */ 200 FailFast, /* Minimal retries should be attempted on 201 * this device, so use REQ_FAILFAST_DEV. 202 * Also don't try to repair failed reads. 203 * It is expects that no bad block log 204 * is present. 205 */ 206 LastDev, /* Seems to be the last working dev as 207 * it didn't fail, so don't use FailFast 208 * any more for metadata 209 */ 210 CollisionCheck, /* 211 * check if there is collision between raid1 212 * serial bios. 213 */ 214 }; 215 216 static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors, 217 sector_t *first_bad, int *bad_sectors) 218 { 219 if (unlikely(rdev->badblocks.count)) { 220 int rv = badblocks_check(&rdev->badblocks, rdev->data_offset + s, 221 sectors, 222 first_bad, bad_sectors); 223 if (rv) 224 *first_bad -= rdev->data_offset; 225 return rv; 226 } 227 return 0; 228 } 229 extern int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors, 230 int is_new); 231 extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors, 232 int is_new); 233 struct md_cluster_info; 234 235 /** 236 * enum mddev_flags - md device flags. 237 * @MD_ARRAY_FIRST_USE: First use of array, needs initialization. 238 * @MD_CLOSING: If set, we are closing the array, do not open it then. 239 * @MD_JOURNAL_CLEAN: A raid with journal is already clean. 240 * @MD_HAS_JOURNAL: The raid array has journal feature set. 241 * @MD_CLUSTER_RESYNC_LOCKED: cluster raid only, which means node, already took 242 * resync lock, need to release the lock. 243 * @MD_FAILFAST_SUPPORTED: Using MD_FAILFAST on metadata writes is supported as 244 * calls to md_error() will never cause the array to 245 * become failed. 246 * @MD_HAS_PPL: The raid array has PPL feature set. 247 * @MD_HAS_MULTIPLE_PPLS: The raid array has multiple PPLs feature set. 248 * @MD_ALLOW_SB_UPDATE: md_check_recovery is allowed to update the metadata 249 * without taking reconfig_mutex. 250 * @MD_UPDATING_SB: md_check_recovery is updating the metadata without 251 * explicitly holding reconfig_mutex. 252 * @MD_NOT_READY: do_md_run() is active, so 'array_state', ust not report that 253 * array is ready yet. 254 * @MD_BROKEN: This is used to stop writes and mark array as failed. 255 * @MD_DELETED: This device is being deleted 256 * 257 * change UNSUPPORTED_MDDEV_FLAGS for each array type if new flag is added 258 */ 259 enum mddev_flags { 260 MD_ARRAY_FIRST_USE, 261 MD_CLOSING, 262 MD_JOURNAL_CLEAN, 263 MD_HAS_JOURNAL, 264 MD_CLUSTER_RESYNC_LOCKED, 265 MD_FAILFAST_SUPPORTED, 266 MD_HAS_PPL, 267 MD_HAS_MULTIPLE_PPLS, 268 MD_ALLOW_SB_UPDATE, 269 MD_UPDATING_SB, 270 MD_NOT_READY, 271 MD_BROKEN, 272 MD_DELETED, 273 }; 274 275 enum mddev_sb_flags { 276 MD_SB_CHANGE_DEVS, /* Some device status has changed */ 277 MD_SB_CHANGE_CLEAN, /* transition to or from 'clean' */ 278 MD_SB_CHANGE_PENDING, /* switch from 'clean' to 'active' in progress */ 279 MD_SB_NEED_REWRITE, /* metadata write needs to be repeated */ 280 }; 281 282 #define NR_SERIAL_INFOS 8 283 /* record current range of serialize IOs */ 284 struct serial_info { 285 struct rb_node node; 286 sector_t start; /* start sector of rb node */ 287 sector_t last; /* end sector of rb node */ 288 sector_t _subtree_last; /* highest sector in subtree of rb node */ 289 }; 290 291 /* 292 * mddev->curr_resync stores the current sector of the resync but 293 * also has some overloaded values. 294 */ 295 enum { 296 /* No resync in progress */ 297 MD_RESYNC_NONE = 0, 298 /* Yielded to allow another conflicting resync to commence */ 299 MD_RESYNC_YIELDED = 1, 300 /* Delayed to check that there is no conflict with another sync */ 301 MD_RESYNC_DELAYED = 2, 302 /* Any value greater than or equal to this is in an active resync */ 303 MD_RESYNC_ACTIVE = 3, 304 }; 305 306 struct mddev { 307 void *private; 308 struct md_personality *pers; 309 dev_t unit; 310 int md_minor; 311 struct list_head disks; 312 unsigned long flags; 313 unsigned long sb_flags; 314 315 int suspended; 316 struct percpu_ref active_io; 317 int ro; 318 int sysfs_active; /* set when sysfs deletes 319 * are happening, so run/ 320 * takeover/stop are not safe 321 */ 322 struct gendisk *gendisk; 323 324 struct kobject kobj; 325 int hold_active; 326 #define UNTIL_IOCTL 1 327 #define UNTIL_STOP 2 328 329 /* Superblock information */ 330 int major_version, 331 minor_version, 332 patch_version; 333 int persistent; 334 int external; /* metadata is 335 * managed externally */ 336 char metadata_type[17]; /* externally set*/ 337 int chunk_sectors; 338 time64_t ctime, utime; 339 int level, layout; 340 char clevel[16]; 341 int raid_disks; 342 int max_disks; 343 sector_t dev_sectors; /* used size of 344 * component devices */ 345 sector_t array_sectors; /* exported array size */ 346 int external_size; /* size managed 347 * externally */ 348 __u64 events; 349 /* If the last 'event' was simply a clean->dirty transition, and 350 * we didn't write it to the spares, then it is safe and simple 351 * to just decrement the event count on a dirty->clean transition. 352 * So we record that possibility here. 353 */ 354 int can_decrease_events; 355 356 char uuid[16]; 357 358 /* If the array is being reshaped, we need to record the 359 * new shape and an indication of where we are up to. 360 * This is written to the superblock. 361 * If reshape_position is MaxSector, then no reshape is happening (yet). 362 */ 363 sector_t reshape_position; 364 int delta_disks, new_level, new_layout; 365 int new_chunk_sectors; 366 int reshape_backwards; 367 368 struct md_thread __rcu *thread; /* management thread */ 369 struct md_thread __rcu *sync_thread; /* doing resync or reconstruct */ 370 371 /* 'last_sync_action' is initialized to "none". It is set when a 372 * sync operation (i.e "data-check", "requested-resync", "resync", 373 * "recovery", or "reshape") is started. It holds this value even 374 * when the sync thread is "frozen" (interrupted) or "idle" (stopped 375 * or finished). It is overwritten when a new sync operation is begun. 376 */ 377 char *last_sync_action; 378 sector_t curr_resync; /* last block scheduled */ 379 /* As resync requests can complete out of order, we cannot easily track 380 * how much resync has been completed. So we occasionally pause until 381 * everything completes, then set curr_resync_completed to curr_resync. 382 * As such it may be well behind the real resync mark, but it is a value 383 * we are certain of. 384 */ 385 sector_t curr_resync_completed; 386 unsigned long resync_mark; /* a recent timestamp */ 387 sector_t resync_mark_cnt;/* blocks written at resync_mark */ 388 sector_t curr_mark_cnt; /* blocks scheduled now */ 389 390 sector_t resync_max_sectors; /* may be set by personality */ 391 392 atomic64_t resync_mismatches; /* count of sectors where 393 * parity/replica mismatch found 394 */ 395 396 /* allow user-space to request suspension of IO to regions of the array */ 397 sector_t suspend_lo; 398 sector_t suspend_hi; 399 /* if zero, use the system-wide default */ 400 int sync_speed_min; 401 int sync_speed_max; 402 403 /* resync even though the same disks are shared among md-devices */ 404 int parallel_resync; 405 406 int ok_start_degraded; 407 408 unsigned long recovery; 409 /* If a RAID personality determines that recovery (of a particular 410 * device) will fail due to a read error on the source device, it 411 * takes a copy of this number and does not attempt recovery again 412 * until this number changes. 413 */ 414 int recovery_disabled; 415 416 int in_sync; /* know to not need resync */ 417 /* 'open_mutex' avoids races between 'md_open' and 'do_md_stop', so 418 * that we are never stopping an array while it is open. 419 * 'reconfig_mutex' protects all other reconfiguration. 420 * These locks are separate due to conflicting interactions 421 * with disk->open_mutex. 422 * Lock ordering is: 423 * reconfig_mutex -> disk->open_mutex 424 * disk->open_mutex -> open_mutex: e.g. __blkdev_get -> md_open 425 */ 426 struct mutex open_mutex; 427 struct mutex reconfig_mutex; 428 atomic_t active; /* general refcount */ 429 atomic_t openers; /* number of active opens */ 430 431 int changed; /* True if we might need to 432 * reread partition info */ 433 int degraded; /* whether md should consider 434 * adding a spare 435 */ 436 437 atomic_t recovery_active; /* blocks scheduled, but not written */ 438 wait_queue_head_t recovery_wait; 439 sector_t recovery_cp; 440 sector_t resync_min; /* user requested sync 441 * starts here */ 442 sector_t resync_max; /* resync should pause 443 * when it gets here */ 444 445 struct kernfs_node *sysfs_state; /* handle for 'array_state' 446 * file in sysfs. 447 */ 448 struct kernfs_node *sysfs_action; /* handle for 'sync_action' */ 449 struct kernfs_node *sysfs_completed; /*handle for 'sync_completed' */ 450 struct kernfs_node *sysfs_degraded; /*handle for 'degraded' */ 451 struct kernfs_node *sysfs_level; /*handle for 'level' */ 452 453 struct work_struct del_work; /* used for delayed sysfs removal */ 454 455 /* "lock" protects: 456 * flush_bio transition from NULL to !NULL 457 * rdev superblocks, events 458 * clearing MD_CHANGE_* 459 * in_sync - and related safemode and MD_CHANGE changes 460 * pers (also protected by reconfig_mutex and pending IO). 461 * clearing ->bitmap 462 * clearing ->bitmap_info.file 463 * changing ->resync_{min,max} 464 * setting MD_RECOVERY_RUNNING (which interacts with resync_{min,max}) 465 */ 466 spinlock_t lock; 467 wait_queue_head_t sb_wait; /* for waiting on superblock updates */ 468 atomic_t pending_writes; /* number of active superblock writes */ 469 470 unsigned int safemode; /* if set, update "clean" superblock 471 * when no writes pending. 472 */ 473 unsigned int safemode_delay; 474 struct timer_list safemode_timer; 475 struct percpu_ref writes_pending; 476 int sync_checkers; /* # of threads checking writes_pending */ 477 struct request_queue *queue; /* for plugging ... */ 478 479 struct bitmap *bitmap; /* the bitmap for the device */ 480 struct { 481 struct file *file; /* the bitmap file */ 482 loff_t offset; /* offset from superblock of 483 * start of bitmap. May be 484 * negative, but not '0' 485 * For external metadata, offset 486 * from start of device. 487 */ 488 unsigned long space; /* space available at this offset */ 489 loff_t default_offset; /* this is the offset to use when 490 * hot-adding a bitmap. It should 491 * eventually be settable by sysfs. 492 */ 493 unsigned long default_space; /* space available at 494 * default offset */ 495 struct mutex mutex; 496 unsigned long chunksize; 497 unsigned long daemon_sleep; /* how many jiffies between updates? */ 498 unsigned long max_write_behind; /* write-behind mode */ 499 int external; 500 int nodes; /* Maximum number of nodes in the cluster */ 501 char cluster_name[64]; /* Name of the cluster */ 502 } bitmap_info; 503 504 atomic_t max_corr_read_errors; /* max read retries */ 505 struct list_head all_mddevs; 506 507 const struct attribute_group *to_remove; 508 509 struct bio_set bio_set; 510 struct bio_set sync_set; /* for sync operations like 511 * metadata and bitmap writes 512 */ 513 struct bio_set io_clone_set; 514 515 /* Generic flush handling. 516 * The last to finish preflush schedules a worker to submit 517 * the rest of the request (without the REQ_PREFLUSH flag). 518 */ 519 struct bio *flush_bio; 520 atomic_t flush_pending; 521 ktime_t start_flush, prev_flush_start; /* prev_flush_start is when the previous completed 522 * flush was started. 523 */ 524 struct work_struct flush_work; 525 struct work_struct event_work; /* used by dm to report failure event */ 526 mempool_t *serial_info_pool; 527 void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev); 528 struct md_cluster_info *cluster_info; 529 unsigned int good_device_nr; /* good device num within cluster raid */ 530 unsigned int noio_flag; /* for memalloc scope API */ 531 532 /* 533 * Temporarily store rdev that will be finally removed when 534 * reconfig_mutex is unlocked, protected by reconfig_mutex. 535 */ 536 struct list_head deleting; 537 538 /* Used to synchronize idle and frozen for action_store() */ 539 struct mutex sync_mutex; 540 /* The sequence number for sync thread */ 541 atomic_t sync_seq; 542 543 bool has_superblocks:1; 544 bool fail_last_dev:1; 545 bool serialize_policy:1; 546 }; 547 548 enum recovery_flags { 549 /* 550 * If neither SYNC or RESHAPE are set, then it is a recovery. 551 */ 552 MD_RECOVERY_RUNNING, /* a thread is running, or about to be started */ 553 MD_RECOVERY_SYNC, /* actually doing a resync, not a recovery */ 554 MD_RECOVERY_RECOVER, /* doing recovery, or need to try it. */ 555 MD_RECOVERY_INTR, /* resync needs to be aborted for some reason */ 556 MD_RECOVERY_DONE, /* thread is done and is waiting to be reaped */ 557 MD_RECOVERY_NEEDED, /* we might need to start a resync/recover */ 558 MD_RECOVERY_REQUESTED, /* user-space has requested a sync (used with SYNC) */ 559 MD_RECOVERY_CHECK, /* user-space request for check-only, no repair */ 560 MD_RECOVERY_RESHAPE, /* A reshape is happening */ 561 MD_RECOVERY_FROZEN, /* User request to abort, and not restart, any action */ 562 MD_RECOVERY_ERROR, /* sync-action interrupted because io-error */ 563 MD_RECOVERY_WAIT, /* waiting for pers->start() to finish */ 564 MD_RESYNCING_REMOTE, /* remote node is running resync thread */ 565 }; 566 567 enum md_ro_state { 568 MD_RDWR, 569 MD_RDONLY, 570 MD_AUTO_READ, 571 MD_MAX_STATE 572 }; 573 574 static inline bool md_is_rdwr(struct mddev *mddev) 575 { 576 return (mddev->ro == MD_RDWR); 577 } 578 579 static inline bool is_md_suspended(struct mddev *mddev) 580 { 581 return percpu_ref_is_dying(&mddev->active_io); 582 } 583 584 static inline int __must_check mddev_lock(struct mddev *mddev) 585 { 586 return mutex_lock_interruptible(&mddev->reconfig_mutex); 587 } 588 589 /* Sometimes we need to take the lock in a situation where 590 * failure due to interrupts is not acceptable. 591 */ 592 static inline void mddev_lock_nointr(struct mddev *mddev) 593 { 594 mutex_lock(&mddev->reconfig_mutex); 595 } 596 597 static inline int mddev_trylock(struct mddev *mddev) 598 { 599 return mutex_trylock(&mddev->reconfig_mutex); 600 } 601 extern void mddev_unlock(struct mddev *mddev); 602 603 static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors) 604 { 605 atomic_add(nr_sectors, &bdev->bd_disk->sync_io); 606 } 607 608 static inline void md_sync_acct_bio(struct bio *bio, unsigned long nr_sectors) 609 { 610 md_sync_acct(bio->bi_bdev, nr_sectors); 611 } 612 613 struct md_personality 614 { 615 char *name; 616 int level; 617 struct list_head list; 618 struct module *owner; 619 bool __must_check (*make_request)(struct mddev *mddev, struct bio *bio); 620 /* 621 * start up works that do NOT require md_thread. tasks that 622 * requires md_thread should go into start() 623 */ 624 int (*run)(struct mddev *mddev); 625 /* start up works that require md threads */ 626 int (*start)(struct mddev *mddev); 627 void (*free)(struct mddev *mddev, void *priv); 628 void (*status)(struct seq_file *seq, struct mddev *mddev); 629 /* error_handler must set ->faulty and clear ->in_sync 630 * if appropriate, and should abort recovery if needed 631 */ 632 void (*error_handler)(struct mddev *mddev, struct md_rdev *rdev); 633 int (*hot_add_disk) (struct mddev *mddev, struct md_rdev *rdev); 634 int (*hot_remove_disk) (struct mddev *mddev, struct md_rdev *rdev); 635 int (*spare_active) (struct mddev *mddev); 636 sector_t (*sync_request)(struct mddev *mddev, sector_t sector_nr, int *skipped); 637 int (*resize) (struct mddev *mddev, sector_t sectors); 638 sector_t (*size) (struct mddev *mddev, sector_t sectors, int raid_disks); 639 int (*check_reshape) (struct mddev *mddev); 640 int (*start_reshape) (struct mddev *mddev); 641 void (*finish_reshape) (struct mddev *mddev); 642 void (*update_reshape_pos) (struct mddev *mddev); 643 void (*prepare_suspend) (struct mddev *mddev); 644 /* quiesce suspends or resumes internal processing. 645 * 1 - stop new actions and wait for action io to complete 646 * 0 - return to normal behaviour 647 */ 648 void (*quiesce) (struct mddev *mddev, int quiesce); 649 /* takeover is used to transition an array from one 650 * personality to another. The new personality must be able 651 * to handle the data in the current layout. 652 * e.g. 2drive raid1 -> 2drive raid5 653 * ndrive raid5 -> degraded n+1drive raid6 with special layout 654 * If the takeover succeeds, a new 'private' structure is returned. 655 * This needs to be installed and then ->run used to activate the 656 * array. 657 */ 658 void *(*takeover) (struct mddev *mddev); 659 /* Changes the consistency policy of an active array. */ 660 int (*change_consistency_policy)(struct mddev *mddev, const char *buf); 661 }; 662 663 struct md_sysfs_entry { 664 struct attribute attr; 665 ssize_t (*show)(struct mddev *, char *); 666 ssize_t (*store)(struct mddev *, const char *, size_t); 667 }; 668 extern const struct attribute_group md_bitmap_group; 669 670 static inline struct kernfs_node *sysfs_get_dirent_safe(struct kernfs_node *sd, char *name) 671 { 672 if (sd) 673 return sysfs_get_dirent(sd, name); 674 return sd; 675 } 676 static inline void sysfs_notify_dirent_safe(struct kernfs_node *sd) 677 { 678 if (sd) 679 sysfs_notify_dirent(sd); 680 } 681 682 static inline char * mdname (struct mddev * mddev) 683 { 684 return mddev->gendisk ? mddev->gendisk->disk_name : "mdX"; 685 } 686 687 static inline int sysfs_link_rdev(struct mddev *mddev, struct md_rdev *rdev) 688 { 689 char nm[20]; 690 if (!test_bit(Replacement, &rdev->flags) && 691 !test_bit(Journal, &rdev->flags) && 692 mddev->kobj.sd) { 693 sprintf(nm, "rd%d", rdev->raid_disk); 694 return sysfs_create_link(&mddev->kobj, &rdev->kobj, nm); 695 } else 696 return 0; 697 } 698 699 static inline void sysfs_unlink_rdev(struct mddev *mddev, struct md_rdev *rdev) 700 { 701 char nm[20]; 702 if (!test_bit(Replacement, &rdev->flags) && 703 !test_bit(Journal, &rdev->flags) && 704 mddev->kobj.sd) { 705 sprintf(nm, "rd%d", rdev->raid_disk); 706 sysfs_remove_link(&mddev->kobj, nm); 707 } 708 } 709 710 /* 711 * iterates through some rdev ringlist. It's safe to remove the 712 * current 'rdev'. Dont touch 'tmp' though. 713 */ 714 #define rdev_for_each_list(rdev, tmp, head) \ 715 list_for_each_entry_safe(rdev, tmp, head, same_set) 716 717 /* 718 * iterates through the 'same array disks' ringlist 719 */ 720 #define rdev_for_each(rdev, mddev) \ 721 list_for_each_entry(rdev, &((mddev)->disks), same_set) 722 723 #define rdev_for_each_safe(rdev, tmp, mddev) \ 724 list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set) 725 726 #define rdev_for_each_rcu(rdev, mddev) \ 727 list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set) 728 729 struct md_thread { 730 void (*run) (struct md_thread *thread); 731 struct mddev *mddev; 732 wait_queue_head_t wqueue; 733 unsigned long flags; 734 struct task_struct *tsk; 735 unsigned long timeout; 736 void *private; 737 }; 738 739 struct md_io_clone { 740 struct mddev *mddev; 741 struct bio *orig_bio; 742 unsigned long start_time; 743 struct bio bio_clone; 744 }; 745 746 #define THREAD_WAKEUP 0 747 748 static inline void safe_put_page(struct page *p) 749 { 750 if (p) put_page(p); 751 } 752 753 extern int register_md_personality(struct md_personality *p); 754 extern int unregister_md_personality(struct md_personality *p); 755 extern int register_md_cluster_operations(struct md_cluster_operations *ops, 756 struct module *module); 757 extern int unregister_md_cluster_operations(void); 758 extern int md_setup_cluster(struct mddev *mddev, int nodes); 759 extern void md_cluster_stop(struct mddev *mddev); 760 extern struct md_thread *md_register_thread( 761 void (*run)(struct md_thread *thread), 762 struct mddev *mddev, 763 const char *name); 764 extern void md_unregister_thread(struct mddev *mddev, struct md_thread __rcu **threadp); 765 extern void md_wakeup_thread(struct md_thread __rcu *thread); 766 extern void md_check_recovery(struct mddev *mddev); 767 extern void md_reap_sync_thread(struct mddev *mddev); 768 extern int mddev_init_writes_pending(struct mddev *mddev); 769 extern bool md_write_start(struct mddev *mddev, struct bio *bi); 770 extern void md_write_inc(struct mddev *mddev, struct bio *bi); 771 extern void md_write_end(struct mddev *mddev); 772 extern void md_done_sync(struct mddev *mddev, int blocks, int ok); 773 extern void md_error(struct mddev *mddev, struct md_rdev *rdev); 774 extern void md_finish_reshape(struct mddev *mddev); 775 void md_submit_discard_bio(struct mddev *mddev, struct md_rdev *rdev, 776 struct bio *bio, sector_t start, sector_t size); 777 void md_account_bio(struct mddev *mddev, struct bio **bio); 778 779 extern bool __must_check md_flush_request(struct mddev *mddev, struct bio *bio); 780 extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev, 781 sector_t sector, int size, struct page *page); 782 extern int md_super_wait(struct mddev *mddev); 783 extern int sync_page_io(struct md_rdev *rdev, sector_t sector, int size, 784 struct page *page, blk_opf_t opf, bool metadata_op); 785 extern void md_do_sync(struct md_thread *thread); 786 extern void md_new_event(void); 787 extern void md_allow_write(struct mddev *mddev); 788 extern void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev); 789 extern void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors); 790 extern int md_check_no_bitmap(struct mddev *mddev); 791 extern int md_integrity_register(struct mddev *mddev); 792 extern int md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev); 793 extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale); 794 795 extern void mddev_init(struct mddev *mddev); 796 struct mddev *md_alloc(dev_t dev, char *name); 797 void mddev_put(struct mddev *mddev); 798 extern int md_run(struct mddev *mddev); 799 extern int md_start(struct mddev *mddev); 800 extern void md_stop(struct mddev *mddev); 801 extern void md_stop_writes(struct mddev *mddev); 802 extern int md_rdev_init(struct md_rdev *rdev); 803 extern void md_rdev_clear(struct md_rdev *rdev); 804 805 extern void md_handle_request(struct mddev *mddev, struct bio *bio); 806 extern void mddev_suspend(struct mddev *mddev); 807 extern void mddev_resume(struct mddev *mddev); 808 809 extern void md_reload_sb(struct mddev *mddev, int raid_disk); 810 extern void md_update_sb(struct mddev *mddev, int force); 811 extern void mddev_create_serial_pool(struct mddev *mddev, struct md_rdev *rdev, 812 bool is_suspend); 813 extern void mddev_destroy_serial_pool(struct mddev *mddev, struct md_rdev *rdev, 814 bool is_suspend); 815 struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr); 816 struct md_rdev *md_find_rdev_rcu(struct mddev *mddev, dev_t dev); 817 818 static inline bool is_rdev_broken(struct md_rdev *rdev) 819 { 820 return !disk_live(rdev->bdev->bd_disk); 821 } 822 823 static inline void rdev_dec_pending(struct md_rdev *rdev, struct mddev *mddev) 824 { 825 int faulty = test_bit(Faulty, &rdev->flags); 826 if (atomic_dec_and_test(&rdev->nr_pending) && faulty) { 827 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 828 md_wakeup_thread(mddev->thread); 829 } 830 } 831 832 extern struct md_cluster_operations *md_cluster_ops; 833 static inline int mddev_is_clustered(struct mddev *mddev) 834 { 835 return mddev->cluster_info && mddev->bitmap_info.nodes > 1; 836 } 837 838 /* clear unsupported mddev_flags */ 839 static inline void mddev_clear_unsupported_flags(struct mddev *mddev, 840 unsigned long unsupported_flags) 841 { 842 mddev->flags &= ~unsupported_flags; 843 } 844 845 static inline void mddev_check_write_zeroes(struct mddev *mddev, struct bio *bio) 846 { 847 if (bio_op(bio) == REQ_OP_WRITE_ZEROES && 848 !bio->bi_bdev->bd_disk->queue->limits.max_write_zeroes_sectors) 849 mddev->queue->limits.max_write_zeroes_sectors = 0; 850 } 851 852 struct mdu_array_info_s; 853 struct mdu_disk_info_s; 854 855 extern int mdp_major; 856 extern struct workqueue_struct *md_bitmap_wq; 857 void md_autostart_arrays(int part); 858 int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info); 859 int md_add_new_disk(struct mddev *mddev, struct mdu_disk_info_s *info); 860 int do_md_run(struct mddev *mddev); 861 862 extern const struct block_device_operations md_fops; 863 864 #endif /* _MD_MD_H */ 865