xref: /linux/fs/btrfs/volumes.h (revision 90e0d94d369d342e735a75174439482119b6c393)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2007 Oracle.  All rights reserved.
4  */
5 
6 #ifndef BTRFS_VOLUMES_H
7 #define BTRFS_VOLUMES_H
8 
9 #include <linux/bio.h>
10 #include <linux/sort.h>
11 #include <linux/btrfs.h>
12 #include "async-thread.h"
13 
14 #define BTRFS_MAX_DATA_CHUNK_SIZE	(10ULL * SZ_1G)
15 
16 extern struct mutex uuid_mutex;
17 
18 #define BTRFS_STRIPE_LEN	SZ_64K
19 
20 /* Used by sanity check for btrfs_raid_types. */
21 #define const_ffs(n) (__builtin_ctzll(n) + 1)
22 
23 /*
24  * The conversion from BTRFS_BLOCK_GROUP_* bits to btrfs_raid_type requires
25  * RAID0 always to be the lowest profile bit.
26  * Although it's part of on-disk format and should never change, do extra
27  * compile-time sanity checks.
28  */
29 static_assert(const_ffs(BTRFS_BLOCK_GROUP_RAID0) <
30 	      const_ffs(BTRFS_BLOCK_GROUP_PROFILE_MASK & ~BTRFS_BLOCK_GROUP_RAID0));
31 static_assert(const_ilog2(BTRFS_BLOCK_GROUP_RAID0) >
32 	      ilog2(BTRFS_BLOCK_GROUP_TYPE_MASK));
33 
34 /* ilog2() can handle both constants and variables */
35 #define BTRFS_BG_FLAG_TO_INDEX(profile)					\
36 	ilog2((profile) >> (ilog2(BTRFS_BLOCK_GROUP_RAID0) - 1))
37 
38 enum btrfs_raid_types {
39 	/* SINGLE is the special one as it doesn't have on-disk bit. */
40 	BTRFS_RAID_SINGLE  = 0,
41 
42 	BTRFS_RAID_RAID0   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID0),
43 	BTRFS_RAID_RAID1   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1),
44 	BTRFS_RAID_DUP	   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_DUP),
45 	BTRFS_RAID_RAID10  = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID10),
46 	BTRFS_RAID_RAID5   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID5),
47 	BTRFS_RAID_RAID6   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID6),
48 	BTRFS_RAID_RAID1C3 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1C3),
49 	BTRFS_RAID_RAID1C4 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1C4),
50 
51 	BTRFS_NR_RAID_TYPES
52 };
53 
54 struct btrfs_io_geometry {
55 	/* remaining bytes before crossing a stripe */
56 	u64 len;
57 	/* offset of logical address in chunk */
58 	u64 offset;
59 	/* length of single IO stripe */
60 	u32 stripe_len;
61 	/* offset of address in stripe */
62 	u32 stripe_offset;
63 	/* number of stripe where address falls */
64 	u64 stripe_nr;
65 	/* offset of raid56 stripe into the chunk */
66 	u64 raid56_stripe_offset;
67 };
68 
69 /*
70  * Use sequence counter to get consistent device stat data on
71  * 32-bit processors.
72  */
73 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
74 #include <linux/seqlock.h>
75 #define __BTRFS_NEED_DEVICE_DATA_ORDERED
76 #define btrfs_device_data_ordered_init(device)	\
77 	seqcount_init(&device->data_seqcount)
78 #else
79 #define btrfs_device_data_ordered_init(device) do { } while (0)
80 #endif
81 
82 #define BTRFS_DEV_STATE_WRITEABLE	(0)
83 #define BTRFS_DEV_STATE_IN_FS_METADATA	(1)
84 #define BTRFS_DEV_STATE_MISSING		(2)
85 #define BTRFS_DEV_STATE_REPLACE_TGT	(3)
86 #define BTRFS_DEV_STATE_FLUSH_SENT	(4)
87 #define BTRFS_DEV_STATE_NO_READA	(5)
88 
89 struct btrfs_zoned_device_info;
90 
91 struct btrfs_device {
92 	struct list_head dev_list; /* device_list_mutex */
93 	struct list_head dev_alloc_list; /* chunk mutex */
94 	struct list_head post_commit_list; /* chunk mutex */
95 	struct btrfs_fs_devices *fs_devices;
96 	struct btrfs_fs_info *fs_info;
97 
98 	struct rcu_string __rcu *name;
99 
100 	u64 generation;
101 
102 	struct block_device *bdev;
103 
104 	struct btrfs_zoned_device_info *zone_info;
105 
106 	/* the mode sent to blkdev_get */
107 	fmode_t mode;
108 
109 	/*
110 	 * Device's major-minor number. Must be set even if the device is not
111 	 * opened (bdev == NULL), unless the device is missing.
112 	 */
113 	dev_t devt;
114 	unsigned long dev_state;
115 	blk_status_t last_flush_error;
116 
117 #ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
118 	seqcount_t data_seqcount;
119 #endif
120 
121 	/* the internal btrfs device id */
122 	u64 devid;
123 
124 	/* size of the device in memory */
125 	u64 total_bytes;
126 
127 	/* size of the device on disk */
128 	u64 disk_total_bytes;
129 
130 	/* bytes used */
131 	u64 bytes_used;
132 
133 	/* optimal io alignment for this device */
134 	u32 io_align;
135 
136 	/* optimal io width for this device */
137 	u32 io_width;
138 	/* type and info about this device */
139 	u64 type;
140 
141 	/* minimal io size for this device */
142 	u32 sector_size;
143 
144 	/* physical drive uuid (or lvm uuid) */
145 	u8 uuid[BTRFS_UUID_SIZE];
146 
147 	/*
148 	 * size of the device on the current transaction
149 	 *
150 	 * This variant is update when committing the transaction,
151 	 * and protected by chunk mutex
152 	 */
153 	u64 commit_total_bytes;
154 
155 	/* bytes used on the current transaction */
156 	u64 commit_bytes_used;
157 
158 	/* Bio used for flushing device barriers */
159 	struct bio flush_bio;
160 	struct completion flush_wait;
161 
162 	/* per-device scrub information */
163 	struct scrub_ctx *scrub_ctx;
164 
165 	/* disk I/O failure stats. For detailed description refer to
166 	 * enum btrfs_dev_stat_values in ioctl.h */
167 	int dev_stats_valid;
168 
169 	/* Counter to record the change of device stats */
170 	atomic_t dev_stats_ccnt;
171 	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
172 
173 	struct extent_io_tree alloc_state;
174 
175 	struct completion kobj_unregister;
176 	/* For sysfs/FSID/devinfo/devid/ */
177 	struct kobject devid_kobj;
178 
179 	/* Bandwidth limit for scrub, in bytes */
180 	u64 scrub_speed_max;
181 };
182 
183 /*
184  * Block group or device which contains an active swapfile. Used for preventing
185  * unsafe operations while a swapfile is active.
186  *
187  * These are sorted on (ptr, inode) (note that a block group or device can
188  * contain more than one swapfile). We compare the pointer values because we
189  * don't actually care what the object is, we just need a quick check whether
190  * the object exists in the rbtree.
191  */
192 struct btrfs_swapfile_pin {
193 	struct rb_node node;
194 	void *ptr;
195 	struct inode *inode;
196 	/*
197 	 * If true, ptr points to a struct btrfs_block_group. Otherwise, ptr
198 	 * points to a struct btrfs_device.
199 	 */
200 	bool is_block_group;
201 	/*
202 	 * Only used when 'is_block_group' is true and it is the number of
203 	 * extents used by a swapfile for this block group ('ptr' field).
204 	 */
205 	int bg_extent_count;
206 };
207 
208 /*
209  * If we read those variants at the context of their own lock, we needn't
210  * use the following helpers, reading them directly is safe.
211  */
212 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
213 #define BTRFS_DEVICE_GETSET_FUNCS(name)					\
214 static inline u64							\
215 btrfs_device_get_##name(const struct btrfs_device *dev)			\
216 {									\
217 	u64 size;							\
218 	unsigned int seq;						\
219 									\
220 	do {								\
221 		seq = read_seqcount_begin(&dev->data_seqcount);		\
222 		size = dev->name;					\
223 	} while (read_seqcount_retry(&dev->data_seqcount, seq));	\
224 	return size;							\
225 }									\
226 									\
227 static inline void							\
228 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
229 {									\
230 	preempt_disable();						\
231 	write_seqcount_begin(&dev->data_seqcount);			\
232 	dev->name = size;						\
233 	write_seqcount_end(&dev->data_seqcount);			\
234 	preempt_enable();						\
235 }
236 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
237 #define BTRFS_DEVICE_GETSET_FUNCS(name)					\
238 static inline u64							\
239 btrfs_device_get_##name(const struct btrfs_device *dev)			\
240 {									\
241 	u64 size;							\
242 									\
243 	preempt_disable();						\
244 	size = dev->name;						\
245 	preempt_enable();						\
246 	return size;							\
247 }									\
248 									\
249 static inline void							\
250 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
251 {									\
252 	preempt_disable();						\
253 	dev->name = size;						\
254 	preempt_enable();						\
255 }
256 #else
257 #define BTRFS_DEVICE_GETSET_FUNCS(name)					\
258 static inline u64							\
259 btrfs_device_get_##name(const struct btrfs_device *dev)			\
260 {									\
261 	return dev->name;						\
262 }									\
263 									\
264 static inline void							\
265 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
266 {									\
267 	dev->name = size;						\
268 }
269 #endif
270 
271 BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
272 BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
273 BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
274 
275 enum btrfs_chunk_allocation_policy {
276 	BTRFS_CHUNK_ALLOC_REGULAR,
277 	BTRFS_CHUNK_ALLOC_ZONED,
278 };
279 
280 /*
281  * Read policies for mirrored block group profiles, read picks the stripe based
282  * on these policies.
283  */
284 enum btrfs_read_policy {
285 	/* Use process PID to choose the stripe */
286 	BTRFS_READ_POLICY_PID,
287 	BTRFS_NR_READ_POLICY,
288 };
289 
290 struct btrfs_fs_devices {
291 	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
292 	u8 metadata_uuid[BTRFS_FSID_SIZE];
293 	bool fsid_change;
294 	struct list_head fs_list;
295 
296 	/*
297 	 * Number of devices under this fsid including missing and
298 	 * replace-target device and excludes seed devices.
299 	 */
300 	u64 num_devices;
301 
302 	/*
303 	 * The number of devices that successfully opened, including
304 	 * replace-target, excludes seed devices.
305 	 */
306 	u64 open_devices;
307 
308 	/* The number of devices that are under the chunk allocation list. */
309 	u64 rw_devices;
310 
311 	/* Count of missing devices under this fsid excluding seed device. */
312 	u64 missing_devices;
313 	u64 total_rw_bytes;
314 
315 	/*
316 	 * Count of devices from btrfs_super_block::num_devices for this fsid,
317 	 * which includes the seed device, excludes the transient replace-target
318 	 * device.
319 	 */
320 	u64 total_devices;
321 
322 	/* Highest generation number of seen devices */
323 	u64 latest_generation;
324 
325 	/*
326 	 * The mount device or a device with highest generation after removal
327 	 * or replace.
328 	 */
329 	struct btrfs_device *latest_dev;
330 
331 	/* all of the devices in the FS, protected by a mutex
332 	 * so we can safely walk it to write out the supers without
333 	 * worrying about add/remove by the multi-device code.
334 	 * Scrubbing super can kick off supers writing by holding
335 	 * this mutex lock.
336 	 */
337 	struct mutex device_list_mutex;
338 
339 	/* List of all devices, protected by device_list_mutex */
340 	struct list_head devices;
341 
342 	/*
343 	 * Devices which can satisfy space allocation. Protected by
344 	 * chunk_mutex
345 	 */
346 	struct list_head alloc_list;
347 
348 	struct list_head seed_list;
349 	bool seeding;
350 
351 	int opened;
352 
353 	/* set when we find or add a device that doesn't have the
354 	 * nonrot flag set
355 	 */
356 	bool rotating;
357 
358 	struct btrfs_fs_info *fs_info;
359 	/* sysfs kobjects */
360 	struct kobject fsid_kobj;
361 	struct kobject *devices_kobj;
362 	struct kobject *devinfo_kobj;
363 	struct completion kobj_unregister;
364 
365 	enum btrfs_chunk_allocation_policy chunk_alloc_policy;
366 
367 	/* Policy used to read the mirrored stripes */
368 	enum btrfs_read_policy read_policy;
369 };
370 
371 #define BTRFS_BIO_INLINE_CSUM_SIZE	64
372 
373 #define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info)	\
374 			- sizeof(struct btrfs_chunk))		\
375 			/ sizeof(struct btrfs_stripe) + 1)
376 
377 #define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE	\
378 				- 2 * sizeof(struct btrfs_disk_key)	\
379 				- 2 * sizeof(struct btrfs_chunk))	\
380 				/ sizeof(struct btrfs_stripe) + 1)
381 
382 /*
383  * Maximum number of sectors for a single bio to limit the size of the
384  * checksum array.  This matches the number of bio_vecs per bio and thus the
385  * I/O size for buffered I/O.
386  */
387 #define BTRFS_MAX_BIO_SECTORS				(256)
388 
389 typedef void (*btrfs_bio_end_io_t)(struct btrfs_bio *bbio);
390 
391 /*
392  * Additional info to pass along bio.
393  *
394  * Mostly for btrfs specific features like csum and mirror_num.
395  */
396 struct btrfs_bio {
397 	unsigned int mirror_num;
398 
399 	/* for direct I/O */
400 	u64 file_offset;
401 
402 	/* @device is for stripe IO submission. */
403 	struct btrfs_device *device;
404 	u8 *csum;
405 	u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
406 	struct bvec_iter iter;
407 
408 	/* End I/O information supplied to btrfs_bio_alloc */
409 	btrfs_bio_end_io_t end_io;
410 	void *private;
411 
412 	/* For read end I/O handling */
413 	struct work_struct end_io_work;
414 
415 	/*
416 	 * This member must come last, bio_alloc_bioset will allocate enough
417 	 * bytes for entire btrfs_bio but relies on bio being last.
418 	 */
419 	struct bio bio;
420 };
421 
422 static inline struct btrfs_bio *btrfs_bio(struct bio *bio)
423 {
424 	return container_of(bio, struct btrfs_bio, bio);
425 }
426 
427 int __init btrfs_bioset_init(void);
428 void __cold btrfs_bioset_exit(void);
429 
430 struct bio *btrfs_bio_alloc(unsigned int nr_vecs, blk_opf_t opf,
431 			    btrfs_bio_end_io_t end_io, void *private);
432 struct bio *btrfs_bio_clone_partial(struct bio *orig, u64 offset, u64 size,
433 				    btrfs_bio_end_io_t end_io, void *private);
434 
435 static inline void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status)
436 {
437 	bbio->bio.bi_status = status;
438 	bbio->end_io(bbio);
439 }
440 
441 static inline void btrfs_bio_free_csum(struct btrfs_bio *bbio)
442 {
443 	if (bbio->csum != bbio->csum_inline) {
444 		kfree(bbio->csum);
445 		bbio->csum = NULL;
446 	}
447 }
448 
449 /*
450  * Iterate through a btrfs_bio (@bbio) on a per-sector basis.
451  *
452  * bvl        - struct bio_vec
453  * bbio       - struct btrfs_bio
454  * iters      - struct bvec_iter
455  * bio_offset - unsigned int
456  */
457 #define btrfs_bio_for_each_sector(fs_info, bvl, bbio, iter, bio_offset)	\
458 	for ((iter) = (bbio)->iter, (bio_offset) = 0;			\
459 	     (iter).bi_size &&					\
460 	     (((bvl) = bio_iter_iovec((&(bbio)->bio), (iter))), 1);	\
461 	     (bio_offset) += fs_info->sectorsize,			\
462 	     bio_advance_iter_single(&(bbio)->bio, &(iter),		\
463 	     (fs_info)->sectorsize))
464 
465 struct btrfs_io_stripe {
466 	struct btrfs_device *dev;
467 	union {
468 		/* Block mapping */
469 		u64 physical;
470 		/* For the endio handler */
471 		struct btrfs_io_context *bioc;
472 	};
473 };
474 
475 struct btrfs_discard_stripe {
476 	struct btrfs_device *dev;
477 	u64 physical;
478 	u64 length;
479 };
480 
481 /*
482  * Context for IO subsmission for device stripe.
483  *
484  * - Track the unfinished mirrors for mirror based profiles
485  *   Mirror based profiles are SINGLE/DUP/RAID1/RAID10.
486  *
487  * - Contain the logical -> physical mapping info
488  *   Used by submit_stripe_bio() for mapping logical bio
489  *   into physical device address.
490  *
491  * - Contain device replace info
492  *   Used by handle_ops_on_dev_replace() to copy logical bios
493  *   into the new device.
494  *
495  * - Contain RAID56 full stripe logical bytenrs
496  */
497 struct btrfs_io_context {
498 	refcount_t refs;
499 	struct btrfs_fs_info *fs_info;
500 	u64 map_type; /* get from map_lookup->type */
501 	struct bio *orig_bio;
502 	atomic_t error;
503 	int max_errors;
504 	int num_stripes;
505 	int mirror_num;
506 	int num_tgtdevs;
507 	int *tgtdev_map;
508 	/*
509 	 * logical block numbers for the start of each stripe
510 	 * The last one or two are p/q.  These are sorted,
511 	 * so raid_map[0] is the start of our full stripe
512 	 */
513 	u64 *raid_map;
514 	struct btrfs_io_stripe stripes[];
515 };
516 
517 struct btrfs_device_info {
518 	struct btrfs_device *dev;
519 	u64 dev_offset;
520 	u64 max_avail;
521 	u64 total_avail;
522 };
523 
524 struct btrfs_raid_attr {
525 	u8 sub_stripes;		/* sub_stripes info for map */
526 	u8 dev_stripes;		/* stripes per dev */
527 	u8 devs_max;		/* max devs to use */
528 	u8 devs_min;		/* min devs needed */
529 	u8 tolerated_failures;	/* max tolerated fail devs */
530 	u8 devs_increment;	/* ndevs has to be a multiple of this */
531 	u8 ncopies;		/* how many copies to data has */
532 	u8 nparity;		/* number of stripes worth of bytes to store
533 				 * parity information */
534 	u8 mindev_error;	/* error code if min devs requisite is unmet */
535 	const char raid_name[8]; /* name of the raid */
536 	u64 bg_flag;		/* block group flag of the raid */
537 };
538 
539 extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
540 
541 struct map_lookup {
542 	u64 type;
543 	int io_align;
544 	int io_width;
545 	u32 stripe_len;
546 	int num_stripes;
547 	int sub_stripes;
548 	int verified_stripes; /* For mount time dev extent verification */
549 	struct btrfs_io_stripe stripes[];
550 };
551 
552 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
553 			    (sizeof(struct btrfs_io_stripe) * (n)))
554 
555 struct btrfs_balance_args;
556 struct btrfs_balance_progress;
557 struct btrfs_balance_control {
558 	struct btrfs_balance_args data;
559 	struct btrfs_balance_args meta;
560 	struct btrfs_balance_args sys;
561 
562 	u64 flags;
563 
564 	struct btrfs_balance_progress stat;
565 };
566 
567 /*
568  * Search for a given device by the set parameters
569  */
570 struct btrfs_dev_lookup_args {
571 	u64 devid;
572 	u8 *uuid;
573 	u8 *fsid;
574 	bool missing;
575 };
576 
577 /* We have to initialize to -1 because BTRFS_DEV_REPLACE_DEVID is 0 */
578 #define BTRFS_DEV_LOOKUP_ARGS_INIT { .devid = (u64)-1 }
579 
580 #define BTRFS_DEV_LOOKUP_ARGS(name) \
581 	struct btrfs_dev_lookup_args name = BTRFS_DEV_LOOKUP_ARGS_INIT
582 
583 enum btrfs_map_op {
584 	BTRFS_MAP_READ,
585 	BTRFS_MAP_WRITE,
586 	BTRFS_MAP_DISCARD,
587 	BTRFS_MAP_GET_READ_MIRRORS,
588 };
589 
590 static inline enum btrfs_map_op btrfs_op(struct bio *bio)
591 {
592 	switch (bio_op(bio)) {
593 	case REQ_OP_DISCARD:
594 		return BTRFS_MAP_DISCARD;
595 	case REQ_OP_WRITE:
596 	case REQ_OP_ZONE_APPEND:
597 		return BTRFS_MAP_WRITE;
598 	default:
599 		WARN_ON_ONCE(1);
600 		fallthrough;
601 	case REQ_OP_READ:
602 		return BTRFS_MAP_READ;
603 	}
604 }
605 
606 void btrfs_get_bioc(struct btrfs_io_context *bioc);
607 void btrfs_put_bioc(struct btrfs_io_context *bioc);
608 int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
609 		    u64 logical, u64 *length,
610 		    struct btrfs_io_context **bioc_ret, int mirror_num);
611 int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
612 		     u64 logical, u64 *length,
613 		     struct btrfs_io_context **bioc_ret);
614 struct btrfs_discard_stripe *btrfs_map_discard(struct btrfs_fs_info *fs_info,
615 					       u64 logical, u64 *length_ret,
616 					       u32 *num_stripes);
617 int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, struct extent_map *map,
618 			  enum btrfs_map_op op, u64 logical,
619 			  struct btrfs_io_geometry *io_geom);
620 int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
621 int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
622 struct btrfs_block_group *btrfs_create_chunk(struct btrfs_trans_handle *trans,
623 					    u64 type);
624 void btrfs_mapping_tree_free(struct extent_map_tree *tree);
625 void btrfs_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio, int mirror_num);
626 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
627 		       fmode_t flags, void *holder);
628 struct btrfs_device *btrfs_scan_one_device(const char *path,
629 					   fmode_t flags, void *holder);
630 int btrfs_forget_devices(dev_t devt);
631 void btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
632 void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices);
633 void btrfs_assign_next_active_device(struct btrfs_device *device,
634 				     struct btrfs_device *this_dev);
635 struct btrfs_device *btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info,
636 						  u64 devid,
637 						  const char *devpath);
638 int btrfs_get_dev_args_from_path(struct btrfs_fs_info *fs_info,
639 				 struct btrfs_dev_lookup_args *args,
640 				 const char *path);
641 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
642 					const u64 *devid,
643 					const u8 *uuid);
644 void btrfs_put_dev_args_from_path(struct btrfs_dev_lookup_args *args);
645 void btrfs_free_device(struct btrfs_device *device);
646 int btrfs_rm_device(struct btrfs_fs_info *fs_info,
647 		    struct btrfs_dev_lookup_args *args,
648 		    struct block_device **bdev, fmode_t *mode);
649 void __exit btrfs_cleanup_fs_uuids(void);
650 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
651 int btrfs_grow_device(struct btrfs_trans_handle *trans,
652 		      struct btrfs_device *device, u64 new_size);
653 struct btrfs_device *btrfs_find_device(const struct btrfs_fs_devices *fs_devices,
654 				       const struct btrfs_dev_lookup_args *args);
655 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
656 int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
657 int btrfs_balance(struct btrfs_fs_info *fs_info,
658 		  struct btrfs_balance_control *bctl,
659 		  struct btrfs_ioctl_balance_args *bargs);
660 void btrfs_describe_block_groups(u64 flags, char *buf, u32 size_buf);
661 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
662 int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
663 int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
664 int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset);
665 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
666 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
667 int btrfs_uuid_scan_kthread(void *data);
668 bool btrfs_chunk_writeable(struct btrfs_fs_info *fs_info, u64 chunk_offset);
669 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
670 			 u64 *start, u64 *max_avail);
671 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
672 int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
673 			struct btrfs_ioctl_get_dev_stats *stats);
674 void btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
675 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
676 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans);
677 void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev);
678 void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev);
679 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev);
680 int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
681 			   u64 logical, u64 len);
682 unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
683 				    u64 logical);
684 u64 btrfs_calc_stripe_length(const struct extent_map *em);
685 int btrfs_nr_parity_stripes(u64 type);
686 int btrfs_chunk_alloc_add_chunk_item(struct btrfs_trans_handle *trans,
687 				     struct btrfs_block_group *bg);
688 int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
689 struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
690 				       u64 logical, u64 length);
691 void btrfs_release_disk_super(struct btrfs_super_block *super);
692 
693 static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
694 				      int index)
695 {
696 	atomic_inc(dev->dev_stat_values + index);
697 	/*
698 	 * This memory barrier orders stores updating statistics before stores
699 	 * updating dev_stats_ccnt.
700 	 *
701 	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
702 	 */
703 	smp_mb__before_atomic();
704 	atomic_inc(&dev->dev_stats_ccnt);
705 }
706 
707 static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
708 				      int index)
709 {
710 	return atomic_read(dev->dev_stat_values + index);
711 }
712 
713 static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
714 						int index)
715 {
716 	int ret;
717 
718 	ret = atomic_xchg(dev->dev_stat_values + index, 0);
719 	/*
720 	 * atomic_xchg implies a full memory barriers as per atomic_t.txt:
721 	 * - RMW operations that have a return value are fully ordered;
722 	 *
723 	 * This implicit memory barriers is paired with the smp_rmb in
724 	 * btrfs_run_dev_stats
725 	 */
726 	atomic_inc(&dev->dev_stats_ccnt);
727 	return ret;
728 }
729 
730 static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
731 				      int index, unsigned long val)
732 {
733 	atomic_set(dev->dev_stat_values + index, val);
734 	/*
735 	 * This memory barrier orders stores updating statistics before stores
736 	 * updating dev_stats_ccnt.
737 	 *
738 	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
739 	 */
740 	smp_mb__before_atomic();
741 	atomic_inc(&dev->dev_stats_ccnt);
742 }
743 
744 void btrfs_commit_device_sizes(struct btrfs_transaction *trans);
745 
746 struct list_head * __attribute_const__ btrfs_get_fs_uuids(void);
747 bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
748 					struct btrfs_device *failing_dev);
749 void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
750 			       struct block_device *bdev,
751 			       const char *device_path);
752 
753 enum btrfs_raid_types __attribute_const__ btrfs_bg_flags_to_raid_index(u64 flags);
754 int btrfs_bg_type_to_factor(u64 flags);
755 const char *btrfs_bg_type_to_raid_name(u64 flags);
756 int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
757 bool btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical);
758 
759 bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);
760 
761 #endif
762