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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 | /* md.h : kernel internal structure of the Linux MD driver Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. You should have received a copy of the GNU General Public License (for example /usr/src/linux/COPYING); if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #ifndef _MD_MD_H #define _MD_MD_H #include <linux/blkdev.h> #include <linux/kobject.h> #include <linux/list.h> #include <linux/mm.h> #include <linux/mutex.h> #include <linux/timer.h> #include <linux/wait.h> #include <linux/workqueue.h> #define MaxSector (~(sector_t)0) /* Bad block numbers are stored sorted in a single page. * 64bits is used for each block or extent. * 54 bits are sector number, 9 bits are extent size, * 1 bit is an 'acknowledged' flag. */ #define MD_MAX_BADBLOCKS (PAGE_SIZE/8) /* * MD's 'extended' device */ struct md_rdev { struct list_head same_set; /* RAID devices within the same set */ sector_t sectors; /* Device size (in 512bytes sectors) */ struct mddev *mddev; /* RAID array if running */ int last_events; /* IO event timestamp */ /* * If meta_bdev is non-NULL, it means that a separate device is * being used to store the metadata (superblock/bitmap) which * would otherwise be contained on the same device as the data (bdev). */ struct block_device *meta_bdev; struct block_device *bdev; /* block device handle */ struct page *sb_page, *bb_page; int sb_loaded; __u64 sb_events; sector_t data_offset; /* start of data in array */ sector_t sb_start; /* offset of the super block (in 512byte sectors) */ int sb_size; /* bytes in the superblock */ int preferred_minor; /* autorun support */ struct kobject kobj; /* A device can be in one of three states based on two flags: * Not working: faulty==1 in_sync==0 * Fully working: faulty==0 in_sync==1 * Working, but not * in sync with array * faulty==0 in_sync==0 * * It can never have faulty==1, in_sync==1 * This reduces the burden of testing multiple flags in many cases */ unsigned long flags; /* bit set of 'enum flag_bits' bits. */ wait_queue_head_t blocked_wait; int desc_nr; /* descriptor index in the superblock */ int raid_disk; /* role of device in array */ int new_raid_disk; /* role that the device will have in * the array after a level-change completes. */ int saved_raid_disk; /* role that device used to have in the * array and could again if we did a partial * resync from the bitmap */ sector_t recovery_offset;/* If this device has been partially * recovered, this is where we were * up to. */ atomic_t nr_pending; /* number of pending requests. * only maintained for arrays that * support hot removal */ atomic_t read_errors; /* number of consecutive read errors that * we have tried to ignore. */ struct timespec last_read_error; /* monotonic time since our * last read error */ atomic_t corrected_errors; /* number of corrected read errors, * for reporting to userspace and storing * in superblock. */ struct work_struct del_work; /* used for delayed sysfs removal */ struct sysfs_dirent *sysfs_state; /* handle for 'state' * sysfs entry */ struct badblocks { int count; /* count of bad blocks */ int unacked_exist; /* there probably are unacknowledged * bad blocks. This is only cleared * when a read discovers none */ int shift; /* shift from sectors to block size * a -ve shift means badblocks are * disabled.*/ u64 *page; /* badblock list */ int changed; seqlock_t lock; sector_t sector; sector_t size; /* in sectors */ } badblocks; }; enum flag_bits { Faulty, /* device is known to have a fault */ In_sync, /* device is in_sync with rest of array */ Unmerged, /* device is being added to array and should * be considerred for bvec_merge_fn but not * yet for actual IO */ WriteMostly, /* Avoid reading if at all possible */ AutoDetected, /* added by auto-detect */ Blocked, /* An error occurred but has not yet * been acknowledged by the metadata * handler, so don't allow writes * until it is cleared */ WriteErrorSeen, /* A write error has been seen on this * device */ FaultRecorded, /* Intermediate state for clearing * Blocked. The Fault is/will-be * recorded in the metadata, but that * metadata hasn't been stored safely * on disk yet. */ BlockedBadBlocks, /* A writer is blocked because they * found an unacknowledged bad-block. * This can safely be cleared at any * time, and the writer will re-check. * It may be set at any time, and at * worst the writer will timeout and * re-check. So setting it as * accurately as possible is good, but * not absolutely critical. */ WantReplacement, /* This device is a candidate to be * hot-replaced, either because it has * reported some faults, or because * of explicit request. */ Replacement, /* This device is a replacement for * a want_replacement device with same * raid_disk number. */ }; #define BB_LEN_MASK (0x00000000000001FFULL) #define BB_OFFSET_MASK (0x7FFFFFFFFFFFFE00ULL) #define BB_ACK_MASK (0x8000000000000000ULL) #define BB_MAX_LEN 512 #define BB_OFFSET(x) (((x) & BB_OFFSET_MASK) >> 9) #define BB_LEN(x) (((x) & BB_LEN_MASK) + 1) #define BB_ACK(x) (!!((x) & BB_ACK_MASK)) #define BB_MAKE(a, l, ack) (((a)<<9) | ((l)-1) | ((u64)(!!(ack)) << 63)) extern int md_is_badblock(struct badblocks *bb, sector_t s, int sectors, sector_t *first_bad, int *bad_sectors); static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors, sector_t *first_bad, int *bad_sectors) { if (unlikely(rdev->badblocks.count)) { int rv = md_is_badblock(&rdev->badblocks, rdev->data_offset + s, sectors, first_bad, bad_sectors); if (rv) *first_bad -= rdev->data_offset; return rv; } return 0; } extern int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors, int acknowledged); extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors); extern void md_ack_all_badblocks(struct badblocks *bb); struct mddev { void *private; struct md_personality *pers; dev_t unit; int md_minor; struct list_head disks; unsigned long flags; #define MD_CHANGE_DEVS 0 /* Some device status has changed */ #define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */ #define MD_CHANGE_PENDING 2 /* switch from 'clean' to 'active' in progress */ #define MD_ARRAY_FIRST_USE 3 /* First use of array, needs initialization */ int suspended; atomic_t active_io; int ro; int sysfs_active; /* set when sysfs deletes * are happening, so run/ * takeover/stop are not safe */ int ready; /* See when safe to pass * IO requests down */ struct gendisk *gendisk; struct kobject kobj; int hold_active; #define UNTIL_IOCTL 1 #define UNTIL_STOP 2 /* Superblock information */ int major_version, minor_version, patch_version; int persistent; int external; /* metadata is * managed externally */ char metadata_type[17]; /* externally set*/ int chunk_sectors; time_t ctime, utime; int level, layout; char clevel[16]; int raid_disks; int max_disks; sector_t dev_sectors; /* used size of * component devices */ sector_t array_sectors; /* exported array size */ int external_size; /* size managed * externally */ __u64 events; /* If the last 'event' was simply a clean->dirty transition, and * we didn't write it to the spares, then it is safe and simple * to just decrement the event count on a dirty->clean transition. * So we record that possibility here. */ int can_decrease_events; char uuid[16]; /* If the array is being reshaped, we need to record the * new shape and an indication of where we are up to. * This is written to the superblock. * If reshape_position is MaxSector, then no reshape is happening (yet). */ sector_t reshape_position; int delta_disks, new_level, new_layout; int new_chunk_sectors; atomic_t plug_cnt; /* If device is expecting * more bios soon. */ struct md_thread *thread; /* management thread */ struct md_thread *sync_thread; /* doing resync or reconstruct */ sector_t curr_resync; /* last block scheduled */ /* As resync requests can complete out of order, we cannot easily track * how much resync has been completed. So we occasionally pause until * everything completes, then set curr_resync_completed to curr_resync. * As such it may be well behind the real resync mark, but it is a value * we are certain of. */ sector_t curr_resync_completed; unsigned long resync_mark; /* a recent timestamp */ sector_t resync_mark_cnt;/* blocks written at resync_mark */ sector_t curr_mark_cnt; /* blocks scheduled now */ sector_t resync_max_sectors; /* may be set by personality */ sector_t resync_mismatches; /* count of sectors where * parity/replica mismatch found */ /* allow user-space to request suspension of IO to regions of the array */ sector_t suspend_lo; sector_t suspend_hi; /* if zero, use the system-wide default */ int sync_speed_min; int sync_speed_max; /* resync even though the same disks are shared among md-devices */ int parallel_resync; int ok_start_degraded; /* recovery/resync flags * NEEDED: we might need to start a resync/recover * RUNNING: a thread is running, or about to be started * SYNC: actually doing a resync, not a recovery * RECOVER: doing recovery, or need to try it. * INTR: resync needs to be aborted for some reason * DONE: thread is done and is waiting to be reaped * REQUEST: user-space has requested a sync (used with SYNC) * CHECK: user-space request for check-only, no repair * RESHAPE: A reshape is happening * * If neither SYNC or RESHAPE are set, then it is a recovery. */ #define MD_RECOVERY_RUNNING 0 #define MD_RECOVERY_SYNC 1 #define MD_RECOVERY_RECOVER 2 #define MD_RECOVERY_INTR 3 #define MD_RECOVERY_DONE 4 #define MD_RECOVERY_NEEDED 5 #define MD_RECOVERY_REQUESTED 6 #define MD_RECOVERY_CHECK 7 #define MD_RECOVERY_RESHAPE 8 #define MD_RECOVERY_FROZEN 9 unsigned long recovery; /* If a RAID personality determines that recovery (of a particular * device) will fail due to a read error on the source device, it * takes a copy of this number and does not attempt recovery again * until this number changes. */ int recovery_disabled; int in_sync; /* know to not need resync */ /* 'open_mutex' avoids races between 'md_open' and 'do_md_stop', so * that we are never stopping an array while it is open. * 'reconfig_mutex' protects all other reconfiguration. * These locks are separate due to conflicting interactions * with bdev->bd_mutex. * Lock ordering is: * reconfig_mutex -> bd_mutex : e.g. do_md_run -> revalidate_disk * bd_mutex -> open_mutex: e.g. __blkdev_get -> md_open */ struct mutex open_mutex; struct mutex reconfig_mutex; atomic_t active; /* general refcount */ atomic_t openers; /* number of active opens */ int changed; /* True if we might need to * reread partition info */ int degraded; /* whether md should consider * adding a spare */ int merge_check_needed; /* at least one * member device * has a * merge_bvec_fn */ atomic_t recovery_active; /* blocks scheduled, but not written */ wait_queue_head_t recovery_wait; sector_t recovery_cp; sector_t resync_min; /* user requested sync * starts here */ sector_t resync_max; /* resync should pause * when it gets here */ struct sysfs_dirent *sysfs_state; /* handle for 'array_state' * file in sysfs. */ struct sysfs_dirent *sysfs_action; /* handle for 'sync_action' */ struct work_struct del_work; /* used for delayed sysfs removal */ spinlock_t write_lock; wait_queue_head_t sb_wait; /* for waiting on superblock updates */ atomic_t pending_writes; /* number of active superblock writes */ unsigned int safemode; /* if set, update "clean" superblock * when no writes pending. */ unsigned int safemode_delay; struct timer_list safemode_timer; atomic_t writes_pending; struct request_queue *queue; /* for plugging ... */ struct bitmap *bitmap; /* the bitmap for the device */ struct { struct file *file; /* the bitmap file */ loff_t offset; /* offset from superblock of * start of bitmap. May be * negative, but not '0' * For external metadata, offset * from start of device. */ loff_t default_offset; /* this is the offset to use when * hot-adding a bitmap. It should * eventually be settable by sysfs. */ struct mutex mutex; unsigned long chunksize; unsigned long daemon_sleep; /* how many jiffies between updates? */ unsigned long max_write_behind; /* write-behind mode */ int external; } bitmap_info; atomic_t max_corr_read_errors; /* max read retries */ struct list_head all_mddevs; struct attribute_group *to_remove; struct bio_set *bio_set; /* Generic flush handling. * The last to finish preflush schedules a worker to submit * the rest of the request (without the REQ_FLUSH flag). */ struct bio *flush_bio; atomic_t flush_pending; struct work_struct flush_work; struct work_struct event_work; /* used by dm to report failure event */ void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev); }; static inline void rdev_dec_pending(struct md_rdev *rdev, struct mddev *mddev) { int faulty = test_bit(Faulty, &rdev->flags); if (atomic_dec_and_test(&rdev->nr_pending) && faulty) set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); } static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors) { atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io); } struct md_personality { char *name; int level; struct list_head list; struct module *owner; void (*make_request)(struct mddev *mddev, struct bio *bio); int (*run)(struct mddev *mddev); int (*stop)(struct mddev *mddev); void (*status)(struct seq_file *seq, struct mddev *mddev); /* error_handler must set ->faulty and clear ->in_sync * if appropriate, and should abort recovery if needed */ void (*error_handler)(struct mddev *mddev, struct md_rdev *rdev); int (*hot_add_disk) (struct mddev *mddev, struct md_rdev *rdev); int (*hot_remove_disk) (struct mddev *mddev, struct md_rdev *rdev); int (*spare_active) (struct mddev *mddev); sector_t (*sync_request)(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster); int (*resize) (struct mddev *mddev, sector_t sectors); sector_t (*size) (struct mddev *mddev, sector_t sectors, int raid_disks); int (*check_reshape) (struct mddev *mddev); int (*start_reshape) (struct mddev *mddev); void (*finish_reshape) (struct mddev *mddev); /* quiesce moves between quiescence states * 0 - fully active * 1 - no new requests allowed * others - reserved */ void (*quiesce) (struct mddev *mddev, int state); /* takeover is used to transition an array from one * personality to another. The new personality must be able * to handle the data in the current layout. * e.g. 2drive raid1 -> 2drive raid5 * ndrive raid5 -> degraded n+1drive raid6 with special layout * If the takeover succeeds, a new 'private' structure is returned. * This needs to be installed and then ->run used to activate the * array. */ void *(*takeover) (struct mddev *mddev); }; struct md_sysfs_entry { struct attribute attr; ssize_t (*show)(struct mddev *, char *); ssize_t (*store)(struct mddev *, const char *, size_t); }; extern struct attribute_group md_bitmap_group; static inline struct sysfs_dirent *sysfs_get_dirent_safe(struct sysfs_dirent *sd, char *name) { if (sd) return sysfs_get_dirent(sd, NULL, name); return sd; } static inline void sysfs_notify_dirent_safe(struct sysfs_dirent *sd) { if (sd) sysfs_notify_dirent(sd); } static inline char * mdname (struct mddev * mddev) { return mddev->gendisk ? mddev->gendisk->disk_name : "mdX"; } static inline int sysfs_link_rdev(struct mddev *mddev, struct md_rdev *rdev) { char nm[20]; if (!test_bit(Replacement, &rdev->flags)) { sprintf(nm, "rd%d", rdev->raid_disk); return sysfs_create_link(&mddev->kobj, &rdev->kobj, nm); } else return 0; } static inline void sysfs_unlink_rdev(struct mddev *mddev, struct md_rdev *rdev) { char nm[20]; if (!test_bit(Replacement, &rdev->flags)) { sprintf(nm, "rd%d", rdev->raid_disk); sysfs_remove_link(&mddev->kobj, nm); } } /* * iterates through some rdev ringlist. It's safe to remove the * current 'rdev'. Dont touch 'tmp' though. */ #define rdev_for_each_list(rdev, tmp, head) \ list_for_each_entry_safe(rdev, tmp, head, same_set) /* * iterates through the 'same array disks' ringlist */ #define rdev_for_each(rdev, mddev) \ list_for_each_entry(rdev, &((mddev)->disks), same_set) #define rdev_for_each_safe(rdev, tmp, mddev) \ list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set) #define rdev_for_each_rcu(rdev, mddev) \ list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set) struct md_thread { void (*run) (struct mddev *mddev); struct mddev *mddev; wait_queue_head_t wqueue; unsigned long flags; struct task_struct *tsk; unsigned long timeout; }; #define THREAD_WAKEUP 0 #define __wait_event_lock_irq(wq, condition, lock, cmd) \ do { \ wait_queue_t __wait; \ init_waitqueue_entry(&__wait, current); \ \ add_wait_queue(&wq, &__wait); \ for (;;) { \ set_current_state(TASK_UNINTERRUPTIBLE); \ if (condition) \ break; \ spin_unlock_irq(&lock); \ cmd; \ schedule(); \ spin_lock_irq(&lock); \ } \ current->state = TASK_RUNNING; \ remove_wait_queue(&wq, &__wait); \ } while (0) #define wait_event_lock_irq(wq, condition, lock, cmd) \ do { \ if (condition) \ break; \ __wait_event_lock_irq(wq, condition, lock, cmd); \ } while (0) static inline void safe_put_page(struct page *p) { if (p) put_page(p); } extern int register_md_personality(struct md_personality *p); extern int unregister_md_personality(struct md_personality *p); extern struct md_thread *md_register_thread( void (*run)(struct mddev *mddev), struct mddev *mddev, const char *name); extern void md_unregister_thread(struct md_thread **threadp); extern void md_wakeup_thread(struct md_thread *thread); extern void md_check_recovery(struct mddev *mddev); extern void md_write_start(struct mddev *mddev, struct bio *bi); extern void md_write_end(struct mddev *mddev); extern void md_done_sync(struct mddev *mddev, int blocks, int ok); extern void md_error(struct mddev *mddev, struct md_rdev *rdev); extern int mddev_congested(struct mddev *mddev, int bits); extern void md_flush_request(struct mddev *mddev, struct bio *bio); extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev, sector_t sector, int size, struct page *page); extern void md_super_wait(struct mddev *mddev); extern int sync_page_io(struct md_rdev *rdev, sector_t sector, int size, struct page *page, int rw, bool metadata_op); extern void md_do_sync(struct mddev *mddev); extern void md_new_event(struct mddev *mddev); extern int md_allow_write(struct mddev *mddev); extern void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev); extern void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors); extern int md_check_no_bitmap(struct mddev *mddev); extern int md_integrity_register(struct mddev *mddev); extern void md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev); extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale); extern void restore_bitmap_write_access(struct file *file); extern void mddev_init(struct mddev *mddev); extern int md_run(struct mddev *mddev); extern void md_stop(struct mddev *mddev); extern void md_stop_writes(struct mddev *mddev); extern int md_rdev_init(struct md_rdev *rdev); extern void mddev_suspend(struct mddev *mddev); extern void mddev_resume(struct mddev *mddev); extern struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask, struct mddev *mddev); extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs, struct mddev *mddev); extern int mddev_check_plugged(struct mddev *mddev); extern void md_trim_bio(struct bio *bio, int offset, int size); #endif /* _MD_MD_H */ |