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 Holder, /* rdev is used as holder while opening 215 * underlying disk exclusively. 216 */ 217 }; 218 219 static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors, 220 sector_t *first_bad, int *bad_sectors) 221 { 222 if (unlikely(rdev->badblocks.count)) { 223 int rv = badblocks_check(&rdev->badblocks, rdev->data_offset + s, 224 sectors, 225 first_bad, bad_sectors); 226 if (rv) 227 *first_bad -= rdev->data_offset; 228 return rv; 229 } 230 return 0; 231 } 232 extern int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors, 233 int is_new); 234 extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors, 235 int is_new); 236 struct md_cluster_info; 237 238 /** 239 * enum mddev_flags - md device flags. 240 * @MD_ARRAY_FIRST_USE: First use of array, needs initialization. 241 * @MD_CLOSING: If set, we are closing the array, do not open it then. 242 * @MD_JOURNAL_CLEAN: A raid with journal is already clean. 243 * @MD_HAS_JOURNAL: The raid array has journal feature set. 244 * @MD_CLUSTER_RESYNC_LOCKED: cluster raid only, which means node, already took 245 * resync lock, need to release the lock. 246 * @MD_FAILFAST_SUPPORTED: Using MD_FAILFAST on metadata writes is supported as 247 * calls to md_error() will never cause the array to 248 * become failed. 249 * @MD_HAS_PPL: The raid array has PPL feature set. 250 * @MD_HAS_MULTIPLE_PPLS: The raid array has multiple PPLs feature set. 251 * @MD_ALLOW_SB_UPDATE: md_check_recovery is allowed to update the metadata 252 * without taking reconfig_mutex. 253 * @MD_UPDATING_SB: md_check_recovery is updating the metadata without 254 * explicitly holding reconfig_mutex. 255 * @MD_NOT_READY: do_md_run() is active, so 'array_state', ust not report that 256 * array is ready yet. 257 * @MD_BROKEN: This is used to stop writes and mark array as failed. 258 * @MD_DELETED: This device is being deleted 259 * 260 * change UNSUPPORTED_MDDEV_FLAGS for each array type if new flag is added 261 */ 262 enum mddev_flags { 263 MD_ARRAY_FIRST_USE, 264 MD_CLOSING, 265 MD_JOURNAL_CLEAN, 266 MD_HAS_JOURNAL, 267 MD_CLUSTER_RESYNC_LOCKED, 268 MD_FAILFAST_SUPPORTED, 269 MD_HAS_PPL, 270 MD_HAS_MULTIPLE_PPLS, 271 MD_ALLOW_SB_UPDATE, 272 MD_UPDATING_SB, 273 MD_NOT_READY, 274 MD_BROKEN, 275 MD_DELETED, 276 }; 277 278 enum mddev_sb_flags { 279 MD_SB_CHANGE_DEVS, /* Some device status has changed */ 280 MD_SB_CHANGE_CLEAN, /* transition to or from 'clean' */ 281 MD_SB_CHANGE_PENDING, /* switch from 'clean' to 'active' in progress */ 282 MD_SB_NEED_REWRITE, /* metadata write needs to be repeated */ 283 }; 284 285 #define NR_SERIAL_INFOS 8 286 /* record current range of serialize IOs */ 287 struct serial_info { 288 struct rb_node node; 289 sector_t start; /* start sector of rb node */ 290 sector_t last; /* end sector of rb node */ 291 sector_t _subtree_last; /* highest sector in subtree of rb node */ 292 }; 293 294 /* 295 * mddev->curr_resync stores the current sector of the resync but 296 * also has some overloaded values. 297 */ 298 enum { 299 /* No resync in progress */ 300 MD_RESYNC_NONE = 0, 301 /* Yielded to allow another conflicting resync to commence */ 302 MD_RESYNC_YIELDED = 1, 303 /* Delayed to check that there is no conflict with another sync */ 304 MD_RESYNC_DELAYED = 2, 305 /* Any value greater than or equal to this is in an active resync */ 306 MD_RESYNC_ACTIVE = 3, 307 }; 308 309 struct mddev { 310 void *private; 311 struct md_personality *pers; 312 dev_t unit; 313 int md_minor; 314 struct list_head disks; 315 unsigned long flags; 316 unsigned long sb_flags; 317 318 int suspended; 319 struct percpu_ref active_io; 320 int ro; 321 int sysfs_active; /* set when sysfs deletes 322 * are happening, so run/ 323 * takeover/stop are not safe 324 */ 325 struct gendisk *gendisk; 326 327 struct kobject kobj; 328 int hold_active; 329 #define UNTIL_IOCTL 1 330 #define UNTIL_STOP 2 331 332 /* Superblock information */ 333 int major_version, 334 minor_version, 335 patch_version; 336 int persistent; 337 int external; /* metadata is 338 * managed externally */ 339 char metadata_type[17]; /* externally set*/ 340 int chunk_sectors; 341 time64_t ctime, utime; 342 int level, layout; 343 char clevel[16]; 344 int raid_disks; 345 int max_disks; 346 sector_t dev_sectors; /* used size of 347 * component devices */ 348 sector_t array_sectors; /* exported array size */ 349 int external_size; /* size managed 350 * externally */ 351 __u64 events; 352 /* If the last 'event' was simply a clean->dirty transition, and 353 * we didn't write it to the spares, then it is safe and simple 354 * to just decrement the event count on a dirty->clean transition. 355 * So we record that possibility here. 356 */ 357 int can_decrease_events; 358 359 char uuid[16]; 360 361 /* If the array is being reshaped, we need to record the 362 * new shape and an indication of where we are up to. 363 * This is written to the superblock. 364 * If reshape_position is MaxSector, then no reshape is happening (yet). 365 */ 366 sector_t reshape_position; 367 int delta_disks, new_level, new_layout; 368 int new_chunk_sectors; 369 int reshape_backwards; 370 371 struct md_thread __rcu *thread; /* management thread */ 372 struct md_thread __rcu *sync_thread; /* doing resync or reconstruct */ 373 374 /* 'last_sync_action' is initialized to "none". It is set when a 375 * sync operation (i.e "data-check", "requested-resync", "resync", 376 * "recovery", or "reshape") is started. It holds this value even 377 * when the sync thread is "frozen" (interrupted) or "idle" (stopped 378 * or finished). It is overwritten when a new sync operation is begun. 379 */ 380 char *last_sync_action; 381 sector_t curr_resync; /* last block scheduled */ 382 /* As resync requests can complete out of order, we cannot easily track 383 * how much resync has been completed. So we occasionally pause until 384 * everything completes, then set curr_resync_completed to curr_resync. 385 * As such it may be well behind the real resync mark, but it is a value 386 * we are certain of. 387 */ 388 sector_t curr_resync_completed; 389 unsigned long resync_mark; /* a recent timestamp */ 390 sector_t resync_mark_cnt;/* blocks written at resync_mark */ 391 sector_t curr_mark_cnt; /* blocks scheduled now */ 392 393 sector_t resync_max_sectors; /* may be set by personality */ 394 395 atomic64_t resync_mismatches; /* count of sectors where 396 * parity/replica mismatch found 397 */ 398 399 /* allow user-space to request suspension of IO to regions of the array */ 400 sector_t suspend_lo; 401 sector_t suspend_hi; 402 /* if zero, use the system-wide default */ 403 int sync_speed_min; 404 int sync_speed_max; 405 406 /* resync even though the same disks are shared among md-devices */ 407 int parallel_resync; 408 409 int ok_start_degraded; 410 411 unsigned long recovery; 412 /* If a RAID personality determines that recovery (of a particular 413 * device) will fail due to a read error on the source device, it 414 * takes a copy of this number and does not attempt recovery again 415 * until this number changes. 416 */ 417 int recovery_disabled; 418 419 int in_sync; /* know to not need resync */ 420 /* 'open_mutex' avoids races between 'md_open' and 'do_md_stop', so 421 * that we are never stopping an array while it is open. 422 * 'reconfig_mutex' protects all other reconfiguration. 423 * These locks are separate due to conflicting interactions 424 * with disk->open_mutex. 425 * Lock ordering is: 426 * reconfig_mutex -> disk->open_mutex 427 * disk->open_mutex -> open_mutex: e.g. __blkdev_get -> md_open 428 */ 429 struct mutex open_mutex; 430 struct mutex reconfig_mutex; 431 atomic_t active; /* general refcount */ 432 atomic_t openers; /* number of active opens */ 433 434 int changed; /* True if we might need to 435 * reread partition info */ 436 int degraded; /* whether md should consider 437 * adding a spare 438 */ 439 440 atomic_t recovery_active; /* blocks scheduled, but not written */ 441 wait_queue_head_t recovery_wait; 442 sector_t recovery_cp; 443 sector_t resync_min; /* user requested sync 444 * starts here */ 445 sector_t resync_max; /* resync should pause 446 * when it gets here */ 447 448 struct kernfs_node *sysfs_state; /* handle for 'array_state' 449 * file in sysfs. 450 */ 451 struct kernfs_node *sysfs_action; /* handle for 'sync_action' */ 452 struct kernfs_node *sysfs_completed; /*handle for 'sync_completed' */ 453 struct kernfs_node *sysfs_degraded; /*handle for 'degraded' */ 454 struct kernfs_node *sysfs_level; /*handle for 'level' */ 455 456 struct work_struct del_work; /* used for delayed sysfs removal */ 457 458 /* "lock" protects: 459 * flush_bio transition from NULL to !NULL 460 * rdev superblocks, events 461 * clearing MD_CHANGE_* 462 * in_sync - and related safemode and MD_CHANGE changes 463 * pers (also protected by reconfig_mutex and pending IO). 464 * clearing ->bitmap 465 * clearing ->bitmap_info.file 466 * changing ->resync_{min,max} 467 * setting MD_RECOVERY_RUNNING (which interacts with resync_{min,max}) 468 */ 469 spinlock_t lock; 470 wait_queue_head_t sb_wait; /* for waiting on superblock updates */ 471 atomic_t pending_writes; /* number of active superblock writes */ 472 473 unsigned int safemode; /* if set, update "clean" superblock 474 * when no writes pending. 475 */ 476 unsigned int safemode_delay; 477 struct timer_list safemode_timer; 478 struct percpu_ref writes_pending; 479 int sync_checkers; /* # of threads checking writes_pending */ 480 struct request_queue *queue; /* for plugging ... */ 481 482 struct bitmap *bitmap; /* the bitmap for the device */ 483 struct { 484 struct file *file; /* the bitmap file */ 485 loff_t offset; /* offset from superblock of 486 * start of bitmap. May be 487 * negative, but not '0' 488 * For external metadata, offset 489 * from start of device. 490 */ 491 unsigned long space; /* space available at this offset */ 492 loff_t default_offset; /* this is the offset to use when 493 * hot-adding a bitmap. It should 494 * eventually be settable by sysfs. 495 */ 496 unsigned long default_space; /* space available at 497 * default offset */ 498 struct mutex mutex; 499 unsigned long chunksize; 500 unsigned long daemon_sleep; /* how many jiffies between updates? */ 501 unsigned long max_write_behind; /* write-behind mode */ 502 int external; 503 int nodes; /* Maximum number of nodes in the cluster */ 504 char cluster_name[64]; /* Name of the cluster */ 505 } bitmap_info; 506 507 atomic_t max_corr_read_errors; /* max read retries */ 508 struct list_head all_mddevs; 509 510 const struct attribute_group *to_remove; 511 512 struct bio_set bio_set; 513 struct bio_set sync_set; /* for sync operations like 514 * metadata and bitmap writes 515 */ 516 struct bio_set io_clone_set; 517 518 /* Generic flush handling. 519 * The last to finish preflush schedules a worker to submit 520 * the rest of the request (without the REQ_PREFLUSH flag). 521 */ 522 struct bio *flush_bio; 523 atomic_t flush_pending; 524 ktime_t start_flush, prev_flush_start; /* prev_flush_start is when the previous completed 525 * flush was started. 526 */ 527 struct work_struct flush_work; 528 struct work_struct event_work; /* used by dm to report failure event */ 529 mempool_t *serial_info_pool; 530 void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev); 531 struct md_cluster_info *cluster_info; 532 unsigned int good_device_nr; /* good device num within cluster raid */ 533 unsigned int noio_flag; /* for memalloc scope API */ 534 535 /* 536 * Temporarily store rdev that will be finally removed when 537 * reconfig_mutex is unlocked, protected by reconfig_mutex. 538 */ 539 struct list_head deleting; 540 541 /* Used to synchronize idle and frozen for action_store() */ 542 struct mutex sync_mutex; 543 /* The sequence number for sync thread */ 544 atomic_t sync_seq; 545 546 bool has_superblocks:1; 547 bool fail_last_dev:1; 548 bool serialize_policy:1; 549 }; 550 551 enum recovery_flags { 552 /* 553 * If neither SYNC or RESHAPE are set, then it is a recovery. 554 */ 555 MD_RECOVERY_RUNNING, /* a thread is running, or about to be started */ 556 MD_RECOVERY_SYNC, /* actually doing a resync, not a recovery */ 557 MD_RECOVERY_RECOVER, /* doing recovery, or need to try it. */ 558 MD_RECOVERY_INTR, /* resync needs to be aborted for some reason */ 559 MD_RECOVERY_DONE, /* thread is done and is waiting to be reaped */ 560 MD_RECOVERY_NEEDED, /* we might need to start a resync/recover */ 561 MD_RECOVERY_REQUESTED, /* user-space has requested a sync (used with SYNC) */ 562 MD_RECOVERY_CHECK, /* user-space request for check-only, no repair */ 563 MD_RECOVERY_RESHAPE, /* A reshape is happening */ 564 MD_RECOVERY_FROZEN, /* User request to abort, and not restart, any action */ 565 MD_RECOVERY_ERROR, /* sync-action interrupted because io-error */ 566 MD_RECOVERY_WAIT, /* waiting for pers->start() to finish */ 567 MD_RESYNCING_REMOTE, /* remote node is running resync thread */ 568 }; 569 570 enum md_ro_state { 571 MD_RDWR, 572 MD_RDONLY, 573 MD_AUTO_READ, 574 MD_MAX_STATE 575 }; 576 577 static inline bool md_is_rdwr(struct mddev *mddev) 578 { 579 return (mddev->ro == MD_RDWR); 580 } 581 582 static inline bool is_md_suspended(struct mddev *mddev) 583 { 584 return percpu_ref_is_dying(&mddev->active_io); 585 } 586 587 static inline int __must_check mddev_lock(struct mddev *mddev) 588 { 589 return mutex_lock_interruptible(&mddev->reconfig_mutex); 590 } 591 592 /* Sometimes we need to take the lock in a situation where 593 * failure due to interrupts is not acceptable. 594 */ 595 static inline void mddev_lock_nointr(struct mddev *mddev) 596 { 597 mutex_lock(&mddev->reconfig_mutex); 598 } 599 600 static inline int mddev_trylock(struct mddev *mddev) 601 { 602 return mutex_trylock(&mddev->reconfig_mutex); 603 } 604 extern void mddev_unlock(struct mddev *mddev); 605 606 static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors) 607 { 608 atomic_add(nr_sectors, &bdev->bd_disk->sync_io); 609 } 610 611 static inline void md_sync_acct_bio(struct bio *bio, unsigned long nr_sectors) 612 { 613 md_sync_acct(bio->bi_bdev, nr_sectors); 614 } 615 616 struct md_personality 617 { 618 char *name; 619 int level; 620 struct list_head list; 621 struct module *owner; 622 bool __must_check (*make_request)(struct mddev *mddev, struct bio *bio); 623 /* 624 * start up works that do NOT require md_thread. tasks that 625 * requires md_thread should go into start() 626 */ 627 int (*run)(struct mddev *mddev); 628 /* start up works that require md threads */ 629 int (*start)(struct mddev *mddev); 630 void (*free)(struct mddev *mddev, void *priv); 631 void (*status)(struct seq_file *seq, struct mddev *mddev); 632 /* error_handler must set ->faulty and clear ->in_sync 633 * if appropriate, and should abort recovery if needed 634 */ 635 void (*error_handler)(struct mddev *mddev, struct md_rdev *rdev); 636 int (*hot_add_disk) (struct mddev *mddev, struct md_rdev *rdev); 637 int (*hot_remove_disk) (struct mddev *mddev, struct md_rdev *rdev); 638 int (*spare_active) (struct mddev *mddev); 639 sector_t (*sync_request)(struct mddev *mddev, sector_t sector_nr, int *skipped); 640 int (*resize) (struct mddev *mddev, sector_t sectors); 641 sector_t (*size) (struct mddev *mddev, sector_t sectors, int raid_disks); 642 int (*check_reshape) (struct mddev *mddev); 643 int (*start_reshape) (struct mddev *mddev); 644 void (*finish_reshape) (struct mddev *mddev); 645 void (*update_reshape_pos) (struct mddev *mddev); 646 void (*prepare_suspend) (struct mddev *mddev); 647 /* quiesce suspends or resumes internal processing. 648 * 1 - stop new actions and wait for action io to complete 649 * 0 - return to normal behaviour 650 */ 651 void (*quiesce) (struct mddev *mddev, int quiesce); 652 /* takeover is used to transition an array from one 653 * personality to another. The new personality must be able 654 * to handle the data in the current layout. 655 * e.g. 2drive raid1 -> 2drive raid5 656 * ndrive raid5 -> degraded n+1drive raid6 with special layout 657 * If the takeover succeeds, a new 'private' structure is returned. 658 * This needs to be installed and then ->run used to activate the 659 * array. 660 */ 661 void *(*takeover) (struct mddev *mddev); 662 /* Changes the consistency policy of an active array. */ 663 int (*change_consistency_policy)(struct mddev *mddev, const char *buf); 664 }; 665 666 struct md_sysfs_entry { 667 struct attribute attr; 668 ssize_t (*show)(struct mddev *, char *); 669 ssize_t (*store)(struct mddev *, const char *, size_t); 670 }; 671 extern const struct attribute_group md_bitmap_group; 672 673 static inline struct kernfs_node *sysfs_get_dirent_safe(struct kernfs_node *sd, char *name) 674 { 675 if (sd) 676 return sysfs_get_dirent(sd, name); 677 return sd; 678 } 679 static inline void sysfs_notify_dirent_safe(struct kernfs_node *sd) 680 { 681 if (sd) 682 sysfs_notify_dirent(sd); 683 } 684 685 static inline char * mdname (struct mddev * mddev) 686 { 687 return mddev->gendisk ? mddev->gendisk->disk_name : "mdX"; 688 } 689 690 static inline int sysfs_link_rdev(struct mddev *mddev, struct md_rdev *rdev) 691 { 692 char nm[20]; 693 if (!test_bit(Replacement, &rdev->flags) && 694 !test_bit(Journal, &rdev->flags) && 695 mddev->kobj.sd) { 696 sprintf(nm, "rd%d", rdev->raid_disk); 697 return sysfs_create_link(&mddev->kobj, &rdev->kobj, nm); 698 } else 699 return 0; 700 } 701 702 static inline void sysfs_unlink_rdev(struct mddev *mddev, struct md_rdev *rdev) 703 { 704 char nm[20]; 705 if (!test_bit(Replacement, &rdev->flags) && 706 !test_bit(Journal, &rdev->flags) && 707 mddev->kobj.sd) { 708 sprintf(nm, "rd%d", rdev->raid_disk); 709 sysfs_remove_link(&mddev->kobj, nm); 710 } 711 } 712 713 /* 714 * iterates through some rdev ringlist. It's safe to remove the 715 * current 'rdev'. Dont touch 'tmp' though. 716 */ 717 #define rdev_for_each_list(rdev, tmp, head) \ 718 list_for_each_entry_safe(rdev, tmp, head, same_set) 719 720 /* 721 * iterates through the 'same array disks' ringlist 722 */ 723 #define rdev_for_each(rdev, mddev) \ 724 list_for_each_entry(rdev, &((mddev)->disks), same_set) 725 726 #define rdev_for_each_safe(rdev, tmp, mddev) \ 727 list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set) 728 729 #define rdev_for_each_rcu(rdev, mddev) \ 730 list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set) 731 732 struct md_thread { 733 void (*run) (struct md_thread *thread); 734 struct mddev *mddev; 735 wait_queue_head_t wqueue; 736 unsigned long flags; 737 struct task_struct *tsk; 738 unsigned long timeout; 739 void *private; 740 }; 741 742 struct md_io_clone { 743 struct mddev *mddev; 744 struct bio *orig_bio; 745 unsigned long start_time; 746 struct bio bio_clone; 747 }; 748 749 #define THREAD_WAKEUP 0 750 751 static inline void safe_put_page(struct page *p) 752 { 753 if (p) put_page(p); 754 } 755 756 extern int register_md_personality(struct md_personality *p); 757 extern int unregister_md_personality(struct md_personality *p); 758 extern int register_md_cluster_operations(struct md_cluster_operations *ops, 759 struct module *module); 760 extern int unregister_md_cluster_operations(void); 761 extern int md_setup_cluster(struct mddev *mddev, int nodes); 762 extern void md_cluster_stop(struct mddev *mddev); 763 extern struct md_thread *md_register_thread( 764 void (*run)(struct md_thread *thread), 765 struct mddev *mddev, 766 const char *name); 767 extern void md_unregister_thread(struct mddev *mddev, struct md_thread __rcu **threadp); 768 extern void md_wakeup_thread(struct md_thread __rcu *thread); 769 extern void md_check_recovery(struct mddev *mddev); 770 extern void md_reap_sync_thread(struct mddev *mddev); 771 extern int mddev_init_writes_pending(struct mddev *mddev); 772 extern bool md_write_start(struct mddev *mddev, struct bio *bi); 773 extern void md_write_inc(struct mddev *mddev, struct bio *bi); 774 extern void md_write_end(struct mddev *mddev); 775 extern void md_done_sync(struct mddev *mddev, int blocks, int ok); 776 extern void md_error(struct mddev *mddev, struct md_rdev *rdev); 777 extern void md_finish_reshape(struct mddev *mddev); 778 void md_submit_discard_bio(struct mddev *mddev, struct md_rdev *rdev, 779 struct bio *bio, sector_t start, sector_t size); 780 void md_account_bio(struct mddev *mddev, struct bio **bio); 781 782 extern bool __must_check md_flush_request(struct mddev *mddev, struct bio *bio); 783 extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev, 784 sector_t sector, int size, struct page *page); 785 extern int md_super_wait(struct mddev *mddev); 786 extern int sync_page_io(struct md_rdev *rdev, sector_t sector, int size, 787 struct page *page, blk_opf_t opf, bool metadata_op); 788 extern void md_do_sync(struct md_thread *thread); 789 extern void md_new_event(void); 790 extern void md_allow_write(struct mddev *mddev); 791 extern void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev); 792 extern void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors); 793 extern int md_check_no_bitmap(struct mddev *mddev); 794 extern int md_integrity_register(struct mddev *mddev); 795 extern int md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev); 796 extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale); 797 798 extern void mddev_init(struct mddev *mddev); 799 struct mddev *md_alloc(dev_t dev, char *name); 800 void mddev_put(struct mddev *mddev); 801 extern int md_run(struct mddev *mddev); 802 extern int md_start(struct mddev *mddev); 803 extern void md_stop(struct mddev *mddev); 804 extern void md_stop_writes(struct mddev *mddev); 805 extern int md_rdev_init(struct md_rdev *rdev); 806 extern void md_rdev_clear(struct md_rdev *rdev); 807 808 extern void md_handle_request(struct mddev *mddev, struct bio *bio); 809 extern void mddev_suspend(struct mddev *mddev); 810 extern void mddev_resume(struct mddev *mddev); 811 812 extern void md_reload_sb(struct mddev *mddev, int raid_disk); 813 extern void md_update_sb(struct mddev *mddev, int force); 814 extern void mddev_create_serial_pool(struct mddev *mddev, struct md_rdev *rdev, 815 bool is_suspend); 816 extern void mddev_destroy_serial_pool(struct mddev *mddev, struct md_rdev *rdev, 817 bool is_suspend); 818 struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr); 819 struct md_rdev *md_find_rdev_rcu(struct mddev *mddev, dev_t dev); 820 821 static inline bool is_rdev_broken(struct md_rdev *rdev) 822 { 823 return !disk_live(rdev->bdev->bd_disk); 824 } 825 826 static inline void rdev_dec_pending(struct md_rdev *rdev, struct mddev *mddev) 827 { 828 int faulty = test_bit(Faulty, &rdev->flags); 829 if (atomic_dec_and_test(&rdev->nr_pending) && faulty) { 830 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 831 md_wakeup_thread(mddev->thread); 832 } 833 } 834 835 extern struct md_cluster_operations *md_cluster_ops; 836 static inline int mddev_is_clustered(struct mddev *mddev) 837 { 838 return mddev->cluster_info && mddev->bitmap_info.nodes > 1; 839 } 840 841 /* clear unsupported mddev_flags */ 842 static inline void mddev_clear_unsupported_flags(struct mddev *mddev, 843 unsigned long unsupported_flags) 844 { 845 mddev->flags &= ~unsupported_flags; 846 } 847 848 static inline void mddev_check_write_zeroes(struct mddev *mddev, struct bio *bio) 849 { 850 if (bio_op(bio) == REQ_OP_WRITE_ZEROES && 851 !bio->bi_bdev->bd_disk->queue->limits.max_write_zeroes_sectors) 852 mddev->queue->limits.max_write_zeroes_sectors = 0; 853 } 854 855 struct mdu_array_info_s; 856 struct mdu_disk_info_s; 857 858 extern int mdp_major; 859 extern struct workqueue_struct *md_bitmap_wq; 860 void md_autostart_arrays(int part); 861 int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info); 862 int md_add_new_disk(struct mddev *mddev, struct mdu_disk_info_s *info); 863 int do_md_run(struct mddev *mddev); 864 865 extern const struct block_device_operations md_fops; 866 867 #endif /* _MD_MD_H */ 868