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