1 /* 2 md.h : kernel internal structure of the Linux MD driver 3 Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 2, or (at your option) 8 any later version. 9 10 You should have received a copy of the GNU General Public License 11 (for example /usr/src/linux/COPYING); if not, write to the Free 12 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 13 */ 14 15 #ifndef _MD_MD_H 16 #define _MD_MD_H 17 18 #include <linux/blkdev.h> 19 #include <linux/backing-dev.h> 20 #include <linux/badblocks.h> 21 #include <linux/kobject.h> 22 #include <linux/list.h> 23 #include <linux/mm.h> 24 #include <linux/mutex.h> 25 #include <linux/timer.h> 26 #include <linux/wait.h> 27 #include <linux/workqueue.h> 28 #include "md-cluster.h" 29 30 #define MaxSector (~(sector_t)0) 31 32 /* 33 * MD's 'extended' device 34 */ 35 struct md_rdev { 36 struct list_head same_set; /* RAID devices within the same set */ 37 38 sector_t sectors; /* Device size (in 512bytes sectors) */ 39 struct mddev *mddev; /* RAID array if running */ 40 int last_events; /* IO event timestamp */ 41 42 /* 43 * If meta_bdev is non-NULL, it means that a separate device is 44 * being used to store the metadata (superblock/bitmap) which 45 * would otherwise be contained on the same device as the data (bdev). 46 */ 47 struct block_device *meta_bdev; 48 struct block_device *bdev; /* block device handle */ 49 50 struct page *sb_page, *bb_page; 51 int sb_loaded; 52 __u64 sb_events; 53 sector_t data_offset; /* start of data in array */ 54 sector_t new_data_offset;/* only relevant while reshaping */ 55 sector_t sb_start; /* offset of the super block (in 512byte sectors) */ 56 int sb_size; /* bytes in the superblock */ 57 int preferred_minor; /* autorun support */ 58 59 struct kobject kobj; 60 61 /* A device can be in one of three states based on two flags: 62 * Not working: faulty==1 in_sync==0 63 * Fully working: faulty==0 in_sync==1 64 * Working, but not 65 * in sync with array 66 * faulty==0 in_sync==0 67 * 68 * It can never have faulty==1, in_sync==1 69 * This reduces the burden of testing multiple flags in many cases 70 */ 71 72 unsigned long flags; /* bit set of 'enum flag_bits' bits. */ 73 wait_queue_head_t blocked_wait; 74 75 int desc_nr; /* descriptor index in the superblock */ 76 int raid_disk; /* role of device in array */ 77 int new_raid_disk; /* role that the device will have in 78 * the array after a level-change completes. 79 */ 80 int saved_raid_disk; /* role that device used to have in the 81 * array and could again if we did a partial 82 * resync from the bitmap 83 */ 84 union { 85 sector_t recovery_offset;/* If this device has been partially 86 * recovered, this is where we were 87 * up to. 88 */ 89 sector_t journal_tail; /* If this device is a journal device, 90 * this is the journal tail (journal 91 * recovery start point) 92 */ 93 }; 94 95 atomic_t nr_pending; /* number of pending requests. 96 * only maintained for arrays that 97 * support hot removal 98 */ 99 atomic_t read_errors; /* number of consecutive read errors that 100 * we have tried to ignore. 101 */ 102 struct timespec last_read_error; /* monotonic time since our 103 * last read error 104 */ 105 atomic_t corrected_errors; /* number of corrected read errors, 106 * for reporting to userspace and storing 107 * in superblock. 108 */ 109 struct work_struct del_work; /* used for delayed sysfs removal */ 110 111 struct kernfs_node *sysfs_state; /* handle for 'state' 112 * sysfs entry */ 113 114 struct badblocks badblocks; 115 }; 116 enum flag_bits { 117 Faulty, /* device is known to have a fault */ 118 In_sync, /* device is in_sync with rest of array */ 119 Bitmap_sync, /* ..actually, not quite In_sync. Need a 120 * bitmap-based recovery to get fully in sync 121 */ 122 WriteMostly, /* Avoid reading if at all possible */ 123 AutoDetected, /* added by auto-detect */ 124 Blocked, /* An error occurred but has not yet 125 * been acknowledged by the metadata 126 * handler, so don't allow writes 127 * until it is cleared */ 128 WriteErrorSeen, /* A write error has been seen on this 129 * device 130 */ 131 FaultRecorded, /* Intermediate state for clearing 132 * Blocked. The Fault is/will-be 133 * recorded in the metadata, but that 134 * metadata hasn't been stored safely 135 * on disk yet. 136 */ 137 BlockedBadBlocks, /* A writer is blocked because they 138 * found an unacknowledged bad-block. 139 * This can safely be cleared at any 140 * time, and the writer will re-check. 141 * It may be set at any time, and at 142 * worst the writer will timeout and 143 * re-check. So setting it as 144 * accurately as possible is good, but 145 * not absolutely critical. 146 */ 147 WantReplacement, /* This device is a candidate to be 148 * hot-replaced, either because it has 149 * reported some faults, or because 150 * of explicit request. 151 */ 152 Replacement, /* This device is a replacement for 153 * a want_replacement device with same 154 * raid_disk number. 155 */ 156 Candidate, /* For clustered environments only: 157 * This device is seen locally but not 158 * by the whole cluster 159 */ 160 Journal, /* This device is used as journal for 161 * raid-5/6. 162 * Usually, this device should be faster 163 * than other devices in the array 164 */ 165 ClusterRemove, 166 }; 167 168 static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors, 169 sector_t *first_bad, int *bad_sectors) 170 { 171 if (unlikely(rdev->badblocks.count)) { 172 int rv = badblocks_check(&rdev->badblocks, rdev->data_offset + s, 173 sectors, 174 first_bad, bad_sectors); 175 if (rv) 176 *first_bad -= rdev->data_offset; 177 return rv; 178 } 179 return 0; 180 } 181 extern int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors, 182 int is_new); 183 extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors, 184 int is_new); 185 struct md_cluster_info; 186 187 struct mddev { 188 void *private; 189 struct md_personality *pers; 190 dev_t unit; 191 int md_minor; 192 struct list_head disks; 193 unsigned long flags; 194 #define MD_CHANGE_DEVS 0 /* Some device status has changed */ 195 #define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */ 196 #define MD_CHANGE_PENDING 2 /* switch from 'clean' to 'active' in progress */ 197 #define MD_UPDATE_SB_FLAGS (1 | 2 | 4) /* If these are set, md_update_sb needed */ 198 #define MD_ARRAY_FIRST_USE 3 /* First use of array, needs initialization */ 199 #define MD_STILL_CLOSED 4 /* If set, then array has not been opened since 200 * md_ioctl checked on it. 201 */ 202 #define MD_JOURNAL_CLEAN 5 /* A raid with journal is already clean */ 203 #define MD_HAS_JOURNAL 6 /* The raid array has journal feature set */ 204 #define MD_RELOAD_SB 7 /* Reload the superblock because another node 205 * updated it. 206 */ 207 208 int suspended; 209 atomic_t active_io; 210 int ro; 211 int sysfs_active; /* set when sysfs deletes 212 * are happening, so run/ 213 * takeover/stop are not safe 214 */ 215 struct gendisk *gendisk; 216 217 struct kobject kobj; 218 int hold_active; 219 #define UNTIL_IOCTL 1 220 #define UNTIL_STOP 2 221 222 /* Superblock information */ 223 int major_version, 224 minor_version, 225 patch_version; 226 int persistent; 227 int external; /* metadata is 228 * managed externally */ 229 char metadata_type[17]; /* externally set*/ 230 int chunk_sectors; 231 time64_t ctime, utime; 232 int level, layout; 233 char clevel[16]; 234 int raid_disks; 235 int max_disks; 236 sector_t dev_sectors; /* used size of 237 * component devices */ 238 sector_t array_sectors; /* exported array size */ 239 int external_size; /* size managed 240 * externally */ 241 __u64 events; 242 /* If the last 'event' was simply a clean->dirty transition, and 243 * we didn't write it to the spares, then it is safe and simple 244 * to just decrement the event count on a dirty->clean transition. 245 * So we record that possibility here. 246 */ 247 int can_decrease_events; 248 249 char uuid[16]; 250 251 /* If the array is being reshaped, we need to record the 252 * new shape and an indication of where we are up to. 253 * This is written to the superblock. 254 * If reshape_position is MaxSector, then no reshape is happening (yet). 255 */ 256 sector_t reshape_position; 257 int delta_disks, new_level, new_layout; 258 int new_chunk_sectors; 259 int reshape_backwards; 260 261 struct md_thread *thread; /* management thread */ 262 struct md_thread *sync_thread; /* doing resync or reconstruct */ 263 264 /* 'last_sync_action' is initialized to "none". It is set when a 265 * sync operation (i.e "data-check", "requested-resync", "resync", 266 * "recovery", or "reshape") is started. It holds this value even 267 * when the sync thread is "frozen" (interrupted) or "idle" (stopped 268 * or finished). It is overwritten when a new sync operation is begun. 269 */ 270 char *last_sync_action; 271 sector_t curr_resync; /* last block scheduled */ 272 /* As resync requests can complete out of order, we cannot easily track 273 * how much resync has been completed. So we occasionally pause until 274 * everything completes, then set curr_resync_completed to curr_resync. 275 * As such it may be well behind the real resync mark, but it is a value 276 * we are certain of. 277 */ 278 sector_t curr_resync_completed; 279 unsigned long resync_mark; /* a recent timestamp */ 280 sector_t resync_mark_cnt;/* blocks written at resync_mark */ 281 sector_t curr_mark_cnt; /* blocks scheduled now */ 282 283 sector_t resync_max_sectors; /* may be set by personality */ 284 285 atomic64_t resync_mismatches; /* count of sectors where 286 * parity/replica mismatch found 287 */ 288 289 /* allow user-space to request suspension of IO to regions of the array */ 290 sector_t suspend_lo; 291 sector_t suspend_hi; 292 /* if zero, use the system-wide default */ 293 int sync_speed_min; 294 int sync_speed_max; 295 296 /* resync even though the same disks are shared among md-devices */ 297 int parallel_resync; 298 299 int ok_start_degraded; 300 /* recovery/resync flags 301 * NEEDED: we might need to start a resync/recover 302 * RUNNING: a thread is running, or about to be started 303 * SYNC: actually doing a resync, not a recovery 304 * RECOVER: doing recovery, or need to try it. 305 * INTR: resync needs to be aborted for some reason 306 * DONE: thread is done and is waiting to be reaped 307 * REQUEST: user-space has requested a sync (used with SYNC) 308 * CHECK: user-space request for check-only, no repair 309 * RESHAPE: A reshape is happening 310 * ERROR: sync-action interrupted because io-error 311 * 312 * If neither SYNC or RESHAPE are set, then it is a recovery. 313 */ 314 #define MD_RECOVERY_RUNNING 0 315 #define MD_RECOVERY_SYNC 1 316 #define MD_RECOVERY_RECOVER 2 317 #define MD_RECOVERY_INTR 3 318 #define MD_RECOVERY_DONE 4 319 #define MD_RECOVERY_NEEDED 5 320 #define MD_RECOVERY_REQUESTED 6 321 #define MD_RECOVERY_CHECK 7 322 #define MD_RECOVERY_RESHAPE 8 323 #define MD_RECOVERY_FROZEN 9 324 #define MD_RECOVERY_ERROR 10 325 326 unsigned long recovery; 327 /* If a RAID personality determines that recovery (of a particular 328 * device) will fail due to a read error on the source device, it 329 * takes a copy of this number and does not attempt recovery again 330 * until this number changes. 331 */ 332 int recovery_disabled; 333 334 int in_sync; /* know to not need resync */ 335 /* 'open_mutex' avoids races between 'md_open' and 'do_md_stop', so 336 * that we are never stopping an array while it is open. 337 * 'reconfig_mutex' protects all other reconfiguration. 338 * These locks are separate due to conflicting interactions 339 * with bdev->bd_mutex. 340 * Lock ordering is: 341 * reconfig_mutex -> bd_mutex : e.g. do_md_run -> revalidate_disk 342 * bd_mutex -> open_mutex: e.g. __blkdev_get -> md_open 343 */ 344 struct mutex open_mutex; 345 struct mutex reconfig_mutex; 346 atomic_t active; /* general refcount */ 347 atomic_t openers; /* number of active opens */ 348 349 int changed; /* True if we might need to 350 * reread partition info */ 351 int degraded; /* whether md should consider 352 * adding a spare 353 */ 354 355 atomic_t recovery_active; /* blocks scheduled, but not written */ 356 wait_queue_head_t recovery_wait; 357 sector_t recovery_cp; 358 sector_t resync_min; /* user requested sync 359 * starts here */ 360 sector_t resync_max; /* resync should pause 361 * when it gets here */ 362 363 struct kernfs_node *sysfs_state; /* handle for 'array_state' 364 * file in sysfs. 365 */ 366 struct kernfs_node *sysfs_action; /* handle for 'sync_action' */ 367 368 struct work_struct del_work; /* used for delayed sysfs removal */ 369 370 /* "lock" protects: 371 * flush_bio transition from NULL to !NULL 372 * rdev superblocks, events 373 * clearing MD_CHANGE_* 374 * in_sync - and related safemode and MD_CHANGE changes 375 * pers (also protected by reconfig_mutex and pending IO). 376 * clearing ->bitmap 377 * clearing ->bitmap_info.file 378 * changing ->resync_{min,max} 379 * setting MD_RECOVERY_RUNNING (which interacts with resync_{min,max}) 380 */ 381 spinlock_t lock; 382 wait_queue_head_t sb_wait; /* for waiting on superblock updates */ 383 atomic_t pending_writes; /* number of active superblock writes */ 384 385 unsigned int safemode; /* if set, update "clean" superblock 386 * when no writes pending. 387 */ 388 unsigned int safemode_delay; 389 struct timer_list safemode_timer; 390 atomic_t writes_pending; 391 struct request_queue *queue; /* for plugging ... */ 392 393 struct bitmap *bitmap; /* the bitmap for the device */ 394 struct { 395 struct file *file; /* the bitmap file */ 396 loff_t offset; /* offset from superblock of 397 * start of bitmap. May be 398 * negative, but not '0' 399 * For external metadata, offset 400 * from start of device. 401 */ 402 unsigned long space; /* space available at this offset */ 403 loff_t default_offset; /* this is the offset to use when 404 * hot-adding a bitmap. It should 405 * eventually be settable by sysfs. 406 */ 407 unsigned long default_space; /* space available at 408 * default offset */ 409 struct mutex mutex; 410 unsigned long chunksize; 411 unsigned long daemon_sleep; /* how many jiffies between updates? */ 412 unsigned long max_write_behind; /* write-behind mode */ 413 int external; 414 int nodes; /* Maximum number of nodes in the cluster */ 415 char cluster_name[64]; /* Name of the cluster */ 416 } bitmap_info; 417 418 atomic_t max_corr_read_errors; /* max read retries */ 419 struct list_head all_mddevs; 420 421 struct attribute_group *to_remove; 422 423 struct bio_set *bio_set; 424 425 /* Generic flush handling. 426 * The last to finish preflush schedules a worker to submit 427 * the rest of the request (without the REQ_FLUSH flag). 428 */ 429 struct bio *flush_bio; 430 atomic_t flush_pending; 431 struct work_struct flush_work; 432 struct work_struct event_work; /* used by dm to report failure event */ 433 void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev); 434 struct md_cluster_info *cluster_info; 435 unsigned int good_device_nr; /* good device num within cluster raid */ 436 }; 437 438 static inline int __must_check mddev_lock(struct mddev *mddev) 439 { 440 return mutex_lock_interruptible(&mddev->reconfig_mutex); 441 } 442 443 /* Sometimes we need to take the lock in a situation where 444 * failure due to interrupts is not acceptable. 445 */ 446 static inline void mddev_lock_nointr(struct mddev *mddev) 447 { 448 mutex_lock(&mddev->reconfig_mutex); 449 } 450 451 static inline int mddev_is_locked(struct mddev *mddev) 452 { 453 return mutex_is_locked(&mddev->reconfig_mutex); 454 } 455 456 static inline int mddev_trylock(struct mddev *mddev) 457 { 458 return mutex_trylock(&mddev->reconfig_mutex); 459 } 460 extern void mddev_unlock(struct mddev *mddev); 461 462 static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors) 463 { 464 atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io); 465 } 466 467 struct md_personality 468 { 469 char *name; 470 int level; 471 struct list_head list; 472 struct module *owner; 473 void (*make_request)(struct mddev *mddev, struct bio *bio); 474 int (*run)(struct mddev *mddev); 475 void (*free)(struct mddev *mddev, void *priv); 476 void (*status)(struct seq_file *seq, struct mddev *mddev); 477 /* error_handler must set ->faulty and clear ->in_sync 478 * if appropriate, and should abort recovery if needed 479 */ 480 void (*error_handler)(struct mddev *mddev, struct md_rdev *rdev); 481 int (*hot_add_disk) (struct mddev *mddev, struct md_rdev *rdev); 482 int (*hot_remove_disk) (struct mddev *mddev, struct md_rdev *rdev); 483 int (*spare_active) (struct mddev *mddev); 484 sector_t (*sync_request)(struct mddev *mddev, sector_t sector_nr, int *skipped); 485 int (*resize) (struct mddev *mddev, sector_t sectors); 486 sector_t (*size) (struct mddev *mddev, sector_t sectors, int raid_disks); 487 int (*check_reshape) (struct mddev *mddev); 488 int (*start_reshape) (struct mddev *mddev); 489 void (*finish_reshape) (struct mddev *mddev); 490 /* quiesce moves between quiescence states 491 * 0 - fully active 492 * 1 - no new requests allowed 493 * others - reserved 494 */ 495 void (*quiesce) (struct mddev *mddev, int state); 496 /* takeover is used to transition an array from one 497 * personality to another. The new personality must be able 498 * to handle the data in the current layout. 499 * e.g. 2drive raid1 -> 2drive raid5 500 * ndrive raid5 -> degraded n+1drive raid6 with special layout 501 * If the takeover succeeds, a new 'private' structure is returned. 502 * This needs to be installed and then ->run used to activate the 503 * array. 504 */ 505 void *(*takeover) (struct mddev *mddev); 506 /* congested implements bdi.congested_fn(). 507 * Will not be called while array is 'suspended' */ 508 int (*congested)(struct mddev *mddev, int bits); 509 }; 510 511 struct md_sysfs_entry { 512 struct attribute attr; 513 ssize_t (*show)(struct mddev *, char *); 514 ssize_t (*store)(struct mddev *, const char *, size_t); 515 }; 516 extern struct attribute_group md_bitmap_group; 517 518 static inline struct kernfs_node *sysfs_get_dirent_safe(struct kernfs_node *sd, char *name) 519 { 520 if (sd) 521 return sysfs_get_dirent(sd, name); 522 return sd; 523 } 524 static inline void sysfs_notify_dirent_safe(struct kernfs_node *sd) 525 { 526 if (sd) 527 sysfs_notify_dirent(sd); 528 } 529 530 static inline char * mdname (struct mddev * mddev) 531 { 532 return mddev->gendisk ? mddev->gendisk->disk_name : "mdX"; 533 } 534 535 static inline int sysfs_link_rdev(struct mddev *mddev, struct md_rdev *rdev) 536 { 537 char nm[20]; 538 if (!test_bit(Replacement, &rdev->flags) && 539 !test_bit(Journal, &rdev->flags) && 540 mddev->kobj.sd) { 541 sprintf(nm, "rd%d", rdev->raid_disk); 542 return sysfs_create_link(&mddev->kobj, &rdev->kobj, nm); 543 } else 544 return 0; 545 } 546 547 static inline void sysfs_unlink_rdev(struct mddev *mddev, struct md_rdev *rdev) 548 { 549 char nm[20]; 550 if (!test_bit(Replacement, &rdev->flags) && 551 !test_bit(Journal, &rdev->flags) && 552 mddev->kobj.sd) { 553 sprintf(nm, "rd%d", rdev->raid_disk); 554 sysfs_remove_link(&mddev->kobj, nm); 555 } 556 } 557 558 /* 559 * iterates through some rdev ringlist. It's safe to remove the 560 * current 'rdev'. Dont touch 'tmp' though. 561 */ 562 #define rdev_for_each_list(rdev, tmp, head) \ 563 list_for_each_entry_safe(rdev, tmp, head, same_set) 564 565 /* 566 * iterates through the 'same array disks' ringlist 567 */ 568 #define rdev_for_each(rdev, mddev) \ 569 list_for_each_entry(rdev, &((mddev)->disks), same_set) 570 571 #define rdev_for_each_safe(rdev, tmp, mddev) \ 572 list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set) 573 574 #define rdev_for_each_rcu(rdev, mddev) \ 575 list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set) 576 577 struct md_thread { 578 void (*run) (struct md_thread *thread); 579 struct mddev *mddev; 580 wait_queue_head_t wqueue; 581 unsigned long flags; 582 struct task_struct *tsk; 583 unsigned long timeout; 584 void *private; 585 }; 586 587 #define THREAD_WAKEUP 0 588 589 static inline void safe_put_page(struct page *p) 590 { 591 if (p) put_page(p); 592 } 593 594 extern int register_md_personality(struct md_personality *p); 595 extern int unregister_md_personality(struct md_personality *p); 596 extern int register_md_cluster_operations(struct md_cluster_operations *ops, 597 struct module *module); 598 extern int unregister_md_cluster_operations(void); 599 extern int md_setup_cluster(struct mddev *mddev, int nodes); 600 extern void md_cluster_stop(struct mddev *mddev); 601 extern struct md_thread *md_register_thread( 602 void (*run)(struct md_thread *thread), 603 struct mddev *mddev, 604 const char *name); 605 extern void md_unregister_thread(struct md_thread **threadp); 606 extern void md_wakeup_thread(struct md_thread *thread); 607 extern void md_check_recovery(struct mddev *mddev); 608 extern void md_reap_sync_thread(struct mddev *mddev); 609 extern void md_write_start(struct mddev *mddev, struct bio *bi); 610 extern void md_write_end(struct mddev *mddev); 611 extern void md_done_sync(struct mddev *mddev, int blocks, int ok); 612 extern void md_error(struct mddev *mddev, struct md_rdev *rdev); 613 extern void md_finish_reshape(struct mddev *mddev); 614 615 extern int mddev_congested(struct mddev *mddev, int bits); 616 extern void md_flush_request(struct mddev *mddev, struct bio *bio); 617 extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev, 618 sector_t sector, int size, struct page *page); 619 extern void md_super_wait(struct mddev *mddev); 620 extern int sync_page_io(struct md_rdev *rdev, sector_t sector, int size, 621 struct page *page, int rw, bool metadata_op); 622 extern void md_do_sync(struct md_thread *thread); 623 extern void md_new_event(struct mddev *mddev); 624 extern int md_allow_write(struct mddev *mddev); 625 extern void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev); 626 extern void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors); 627 extern int md_check_no_bitmap(struct mddev *mddev); 628 extern int md_integrity_register(struct mddev *mddev); 629 extern int md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev); 630 extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale); 631 632 extern void mddev_init(struct mddev *mddev); 633 extern int md_run(struct mddev *mddev); 634 extern void md_stop(struct mddev *mddev); 635 extern void md_stop_writes(struct mddev *mddev); 636 extern int md_rdev_init(struct md_rdev *rdev); 637 extern void md_rdev_clear(struct md_rdev *rdev); 638 639 extern void mddev_suspend(struct mddev *mddev); 640 extern void mddev_resume(struct mddev *mddev); 641 extern struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask, 642 struct mddev *mddev); 643 extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs, 644 struct mddev *mddev); 645 646 extern void md_unplug(struct blk_plug_cb *cb, bool from_schedule); 647 extern void md_reload_sb(struct mddev *mddev, int raid_disk); 648 extern void md_update_sb(struct mddev *mddev, int force); 649 extern void md_kick_rdev_from_array(struct md_rdev * rdev); 650 struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr); 651 static inline int mddev_check_plugged(struct mddev *mddev) 652 { 653 return !!blk_check_plugged(md_unplug, mddev, 654 sizeof(struct blk_plug_cb)); 655 } 656 657 static inline void rdev_dec_pending(struct md_rdev *rdev, struct mddev *mddev) 658 { 659 int faulty = test_bit(Faulty, &rdev->flags); 660 if (atomic_dec_and_test(&rdev->nr_pending) && faulty) { 661 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); 662 md_wakeup_thread(mddev->thread); 663 } 664 } 665 666 extern struct md_cluster_operations *md_cluster_ops; 667 static inline int mddev_is_clustered(struct mddev *mddev) 668 { 669 return mddev->cluster_info && mddev->bitmap_info.nodes > 1; 670 } 671 #endif /* _MD_MD_H */ 672