xref: /linux/fs/btrfs/volumes.h (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942)
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/sort.h>
10 #include <linux/btrfs.h>
11 #include "async-thread.h"
12 #include "messages.h"
13 #include "tree-checker.h"
14 #include "rcu-string.h"
15 
16 #define BTRFS_MAX_DATA_CHUNK_SIZE	(10ULL * SZ_1G)
17 
18 extern struct mutex uuid_mutex;
19 
20 #define BTRFS_STRIPE_LEN		SZ_64K
21 #define BTRFS_STRIPE_LEN_SHIFT		(16)
22 #define BTRFS_STRIPE_LEN_MASK		(BTRFS_STRIPE_LEN - 1)
23 
24 static_assert(const_ilog2(BTRFS_STRIPE_LEN) == BTRFS_STRIPE_LEN_SHIFT);
25 
26 /* Used by sanity check for btrfs_raid_types. */
27 #define const_ffs(n) (__builtin_ctzll(n) + 1)
28 
29 /*
30  * The conversion from BTRFS_BLOCK_GROUP_* bits to btrfs_raid_type requires
31  * RAID0 always to be the lowest profile bit.
32  * Although it's part of on-disk format and should never change, do extra
33  * compile-time sanity checks.
34  */
35 static_assert(const_ffs(BTRFS_BLOCK_GROUP_RAID0) <
36 	      const_ffs(BTRFS_BLOCK_GROUP_PROFILE_MASK & ~BTRFS_BLOCK_GROUP_RAID0));
37 static_assert(const_ilog2(BTRFS_BLOCK_GROUP_RAID0) >
38 	      ilog2(BTRFS_BLOCK_GROUP_TYPE_MASK));
39 
40 /* ilog2() can handle both constants and variables */
41 #define BTRFS_BG_FLAG_TO_INDEX(profile)					\
42 	ilog2((profile) >> (ilog2(BTRFS_BLOCK_GROUP_RAID0) - 1))
43 
44 enum btrfs_raid_types {
45 	/* SINGLE is the special one as it doesn't have on-disk bit. */
46 	BTRFS_RAID_SINGLE  = 0,
47 
48 	BTRFS_RAID_RAID0   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID0),
49 	BTRFS_RAID_RAID1   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1),
50 	BTRFS_RAID_DUP	   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_DUP),
51 	BTRFS_RAID_RAID10  = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID10),
52 	BTRFS_RAID_RAID5   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID5),
53 	BTRFS_RAID_RAID6   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID6),
54 	BTRFS_RAID_RAID1C3 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1C3),
55 	BTRFS_RAID_RAID1C4 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1C4),
56 
57 	BTRFS_NR_RAID_TYPES
58 };
59 
60 /*
61  * Use sequence counter to get consistent device stat data on
62  * 32-bit processors.
63  */
64 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
65 #include <linux/seqlock.h>
66 #define __BTRFS_NEED_DEVICE_DATA_ORDERED
67 #define btrfs_device_data_ordered_init(device)	\
68 	seqcount_init(&device->data_seqcount)
69 #else
70 #define btrfs_device_data_ordered_init(device) do { } while (0)
71 #endif
72 
73 #define BTRFS_DEV_STATE_WRITEABLE	(0)
74 #define BTRFS_DEV_STATE_IN_FS_METADATA	(1)
75 #define BTRFS_DEV_STATE_MISSING		(2)
76 #define BTRFS_DEV_STATE_REPLACE_TGT	(3)
77 #define BTRFS_DEV_STATE_FLUSH_SENT	(4)
78 #define BTRFS_DEV_STATE_NO_READA	(5)
79 
80 struct btrfs_zoned_device_info;
81 
82 struct btrfs_device {
83 	struct list_head dev_list; /* device_list_mutex */
84 	struct list_head dev_alloc_list; /* chunk mutex */
85 	struct list_head post_commit_list; /* chunk mutex */
86 	struct btrfs_fs_devices *fs_devices;
87 	struct btrfs_fs_info *fs_info;
88 
89 	struct rcu_string __rcu *name;
90 
91 	u64 generation;
92 
93 	struct bdev_handle *bdev_handle;
94 	struct block_device *bdev;
95 
96 	struct btrfs_zoned_device_info *zone_info;
97 
98 	/*
99 	 * Device's major-minor number. Must be set even if the device is not
100 	 * opened (bdev == NULL), unless the device is missing.
101 	 */
102 	dev_t devt;
103 	unsigned long dev_state;
104 	blk_status_t last_flush_error;
105 
106 #ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
107 	seqcount_t data_seqcount;
108 #endif
109 
110 	/* the internal btrfs device id */
111 	u64 devid;
112 
113 	/* size of the device in memory */
114 	u64 total_bytes;
115 
116 	/* size of the device on disk */
117 	u64 disk_total_bytes;
118 
119 	/* bytes used */
120 	u64 bytes_used;
121 
122 	/* optimal io alignment for this device */
123 	u32 io_align;
124 
125 	/* optimal io width for this device */
126 	u32 io_width;
127 	/* type and info about this device */
128 	u64 type;
129 
130 	/* minimal io size for this device */
131 	u32 sector_size;
132 
133 	/* physical drive uuid (or lvm uuid) */
134 	u8 uuid[BTRFS_UUID_SIZE];
135 
136 	/*
137 	 * size of the device on the current transaction
138 	 *
139 	 * This variant is update when committing the transaction,
140 	 * and protected by chunk mutex
141 	 */
142 	u64 commit_total_bytes;
143 
144 	/* bytes used on the current transaction */
145 	u64 commit_bytes_used;
146 
147 	/* Bio used for flushing device barriers */
148 	struct bio flush_bio;
149 	struct completion flush_wait;
150 
151 	/* per-device scrub information */
152 	struct scrub_ctx *scrub_ctx;
153 
154 	/* disk I/O failure stats. For detailed description refer to
155 	 * enum btrfs_dev_stat_values in ioctl.h */
156 	int dev_stats_valid;
157 
158 	/* Counter to record the change of device stats */
159 	atomic_t dev_stats_ccnt;
160 	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
161 
162 	struct extent_io_tree alloc_state;
163 
164 	struct completion kobj_unregister;
165 	/* For sysfs/FSID/devinfo/devid/ */
166 	struct kobject devid_kobj;
167 
168 	/* Bandwidth limit for scrub, in bytes */
169 	u64 scrub_speed_max;
170 };
171 
172 /*
173  * Block group or device which contains an active swapfile. Used for preventing
174  * unsafe operations while a swapfile is active.
175  *
176  * These are sorted on (ptr, inode) (note that a block group or device can
177  * contain more than one swapfile). We compare the pointer values because we
178  * don't actually care what the object is, we just need a quick check whether
179  * the object exists in the rbtree.
180  */
181 struct btrfs_swapfile_pin {
182 	struct rb_node node;
183 	void *ptr;
184 	struct inode *inode;
185 	/*
186 	 * If true, ptr points to a struct btrfs_block_group. Otherwise, ptr
187 	 * points to a struct btrfs_device.
188 	 */
189 	bool is_block_group;
190 	/*
191 	 * Only used when 'is_block_group' is true and it is the number of
192 	 * extents used by a swapfile for this block group ('ptr' field).
193 	 */
194 	int bg_extent_count;
195 };
196 
197 /*
198  * If we read those variants at the context of their own lock, we needn't
199  * use the following helpers, reading them directly is safe.
200  */
201 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
202 #define BTRFS_DEVICE_GETSET_FUNCS(name)					\
203 static inline u64							\
204 btrfs_device_get_##name(const struct btrfs_device *dev)			\
205 {									\
206 	u64 size;							\
207 	unsigned int seq;						\
208 									\
209 	do {								\
210 		seq = read_seqcount_begin(&dev->data_seqcount);		\
211 		size = dev->name;					\
212 	} while (read_seqcount_retry(&dev->data_seqcount, seq));	\
213 	return size;							\
214 }									\
215 									\
216 static inline void							\
217 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
218 {									\
219 	preempt_disable();						\
220 	write_seqcount_begin(&dev->data_seqcount);			\
221 	dev->name = size;						\
222 	write_seqcount_end(&dev->data_seqcount);			\
223 	preempt_enable();						\
224 }
225 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
226 #define BTRFS_DEVICE_GETSET_FUNCS(name)					\
227 static inline u64							\
228 btrfs_device_get_##name(const struct btrfs_device *dev)			\
229 {									\
230 	u64 size;							\
231 									\
232 	preempt_disable();						\
233 	size = dev->name;						\
234 	preempt_enable();						\
235 	return size;							\
236 }									\
237 									\
238 static inline void							\
239 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
240 {									\
241 	preempt_disable();						\
242 	dev->name = size;						\
243 	preempt_enable();						\
244 }
245 #else
246 #define BTRFS_DEVICE_GETSET_FUNCS(name)					\
247 static inline u64							\
248 btrfs_device_get_##name(const struct btrfs_device *dev)			\
249 {									\
250 	return dev->name;						\
251 }									\
252 									\
253 static inline void							\
254 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
255 {									\
256 	dev->name = size;						\
257 }
258 #endif
259 
260 BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
261 BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
262 BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
263 
264 enum btrfs_chunk_allocation_policy {
265 	BTRFS_CHUNK_ALLOC_REGULAR,
266 	BTRFS_CHUNK_ALLOC_ZONED,
267 };
268 
269 /*
270  * Read policies for mirrored block group profiles, read picks the stripe based
271  * on these policies.
272  */
273 enum btrfs_read_policy {
274 	/* Use process PID to choose the stripe */
275 	BTRFS_READ_POLICY_PID,
276 	BTRFS_NR_READ_POLICY,
277 };
278 
279 struct btrfs_fs_devices {
280 	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
281 
282 	/*
283 	 * UUID written into the btree blocks:
284 	 *
285 	 * - If metadata_uuid != fsid then super block must have
286 	 *   BTRFS_FEATURE_INCOMPAT_METADATA_UUID flag set.
287 	 *
288 	 * - Following shall be true at all times:
289 	 *   - metadata_uuid == btrfs_header::fsid
290 	 *   - metadata_uuid == btrfs_dev_item::fsid
291 	 *
292 	 * - Relations between fsid and metadata_uuid in sb and fs_devices:
293 	 *   - Normal:
294 	 *       fs_devices->fsid == fs_devices->metadata_uuid == sb->fsid
295 	 *       sb->metadata_uuid == 0
296 	 *
297 	 *   - When the BTRFS_FEATURE_INCOMPAT_METADATA_UUID flag is set:
298 	 *       fs_devices->fsid == sb->fsid
299 	 *       fs_devices->metadata_uuid == sb->metadata_uuid
300 	 *
301 	 *   - When in-memory fs_devices->temp_fsid is true
302 	 *	 fs_devices->fsid = random
303 	 *	 fs_devices->metadata_uuid == sb->fsid
304 	 */
305 	u8 metadata_uuid[BTRFS_FSID_SIZE];
306 
307 	struct list_head fs_list;
308 
309 	/*
310 	 * Number of devices under this fsid including missing and
311 	 * replace-target device and excludes seed devices.
312 	 */
313 	u64 num_devices;
314 
315 	/*
316 	 * The number of devices that successfully opened, including
317 	 * replace-target, excludes seed devices.
318 	 */
319 	u64 open_devices;
320 
321 	/* The number of devices that are under the chunk allocation list. */
322 	u64 rw_devices;
323 
324 	/* Count of missing devices under this fsid excluding seed device. */
325 	u64 missing_devices;
326 	u64 total_rw_bytes;
327 
328 	/*
329 	 * Count of devices from btrfs_super_block::num_devices for this fsid,
330 	 * which includes the seed device, excludes the transient replace-target
331 	 * device.
332 	 */
333 	u64 total_devices;
334 
335 	/* Highest generation number of seen devices */
336 	u64 latest_generation;
337 
338 	/*
339 	 * The mount device or a device with highest generation after removal
340 	 * or replace.
341 	 */
342 	struct btrfs_device *latest_dev;
343 
344 	/*
345 	 * All of the devices in the filesystem, protected by a mutex so we can
346 	 * safely walk it to write out the super blocks without worrying about
347 	 * adding/removing by the multi-device code. Scrubbing super block can
348 	 * kick off supers writing by holding this mutex lock.
349 	 */
350 	struct mutex device_list_mutex;
351 
352 	/* List of all devices, protected by device_list_mutex */
353 	struct list_head devices;
354 
355 	/* Devices which can satisfy space allocation. Protected by * chunk_mutex. */
356 	struct list_head alloc_list;
357 
358 	struct list_head seed_list;
359 
360 	/* Count fs-devices opened. */
361 	int opened;
362 
363 	/* Set when we find or add a device that doesn't have the nonrot flag set. */
364 	bool rotating;
365 	/* Devices support TRIM/discard commands. */
366 	bool discardable;
367 	/* The filesystem is a seed filesystem. */
368 	bool seeding;
369 	/* The mount needs to use a randomly generated fsid. */
370 	bool temp_fsid;
371 
372 	struct btrfs_fs_info *fs_info;
373 	/* sysfs kobjects */
374 	struct kobject fsid_kobj;
375 	struct kobject *devices_kobj;
376 	struct kobject *devinfo_kobj;
377 	struct completion kobj_unregister;
378 
379 	enum btrfs_chunk_allocation_policy chunk_alloc_policy;
380 
381 	/* Policy used to read the mirrored stripes. */
382 	enum btrfs_read_policy read_policy;
383 };
384 
385 #define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info)	\
386 			- sizeof(struct btrfs_chunk))		\
387 			/ sizeof(struct btrfs_stripe) + 1)
388 
389 #define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE	\
390 				- 2 * sizeof(struct btrfs_disk_key)	\
391 				- 2 * sizeof(struct btrfs_chunk))	\
392 				/ sizeof(struct btrfs_stripe) + 1)
393 
394 struct btrfs_io_stripe {
395 	struct btrfs_device *dev;
396 	/* Block mapping. */
397 	u64 physical;
398 	u64 length;
399 	bool is_scrub;
400 	/* For the endio handler. */
401 	struct btrfs_io_context *bioc;
402 };
403 
404 struct btrfs_discard_stripe {
405 	struct btrfs_device *dev;
406 	u64 physical;
407 	u64 length;
408 };
409 
410 /*
411  * Context for IO subsmission for device stripe.
412  *
413  * - Track the unfinished mirrors for mirror based profiles
414  *   Mirror based profiles are SINGLE/DUP/RAID1/RAID10.
415  *
416  * - Contain the logical -> physical mapping info
417  *   Used by submit_stripe_bio() for mapping logical bio
418  *   into physical device address.
419  *
420  * - Contain device replace info
421  *   Used by handle_ops_on_dev_replace() to copy logical bios
422  *   into the new device.
423  *
424  * - Contain RAID56 full stripe logical bytenrs
425  */
426 struct btrfs_io_context {
427 	refcount_t refs;
428 	struct btrfs_fs_info *fs_info;
429 	u64 map_type; /* get from map_lookup->type */
430 	struct bio *orig_bio;
431 	atomic_t error;
432 	u16 max_errors;
433 
434 	u64 logical;
435 	u64 size;
436 	/* Raid stripe tree ordered entry. */
437 	struct list_head rst_ordered_entry;
438 
439 	/*
440 	 * The total number of stripes, including the extra duplicated
441 	 * stripe for replace.
442 	 */
443 	u16 num_stripes;
444 
445 	/*
446 	 * The mirror_num of this bioc.
447 	 *
448 	 * This is for reads which use 0 as mirror_num, thus we should return a
449 	 * valid mirror_num (>0) for the reader.
450 	 */
451 	u16 mirror_num;
452 
453 	/*
454 	 * The following two members are for dev-replace case only.
455 	 *
456 	 * @replace_nr_stripes:	Number of duplicated stripes which need to be
457 	 *			written to replace target.
458 	 *			Should be <= 2 (2 for DUP, otherwise <= 1).
459 	 * @replace_stripe_src:	The array indicates where the duplicated stripes
460 	 *			are from.
461 	 *
462 	 * The @replace_stripe_src[] array is mostly for RAID56 cases.
463 	 * As non-RAID56 stripes share the same contents of the mapped range,
464 	 * thus no need to bother where the duplicated ones are from.
465 	 *
466 	 * But for RAID56 case, all stripes contain different contents, thus
467 	 * we need a way to know the mapping.
468 	 *
469 	 * There is an example for the two members, using a RAID5 write:
470 	 *
471 	 *   num_stripes:	4 (3 + 1 duplicated write)
472 	 *   stripes[0]:	dev = devid 1, physical = X
473 	 *   stripes[1]:	dev = devid 2, physical = Y
474 	 *   stripes[2]:	dev = devid 3, physical = Z
475 	 *   stripes[3]:	dev = devid 0, physical = Y
476 	 *
477 	 * replace_nr_stripes = 1
478 	 * replace_stripe_src = 1	<- Means stripes[1] is involved in replace.
479 	 *				   The duplicated stripe index would be
480 	 *				   (@num_stripes - 1).
481 	 *
482 	 * Note, that we can still have cases replace_nr_stripes = 2 for DUP.
483 	 * In that case, all stripes share the same content, thus we don't
484 	 * need to bother @replace_stripe_src value at all.
485 	 */
486 	u16 replace_nr_stripes;
487 	s16 replace_stripe_src;
488 	/*
489 	 * Logical bytenr of the full stripe start, only for RAID56 cases.
490 	 *
491 	 * When this value is set to other than (u64)-1, the stripes[] should
492 	 * follow this pattern:
493 	 *
494 	 * (real_stripes = num_stripes - replace_nr_stripes)
495 	 * (data_stripes = (is_raid6) ? (real_stripes - 2) : (real_stripes - 1))
496 	 *
497 	 * stripes[0]:			The first data stripe
498 	 * stripes[1]:			The second data stripe
499 	 * ...
500 	 * stripes[data_stripes - 1]:	The last data stripe
501 	 * stripes[data_stripes]:	The P stripe
502 	 * stripes[data_stripes + 1]:	The Q stripe (only for RAID6).
503 	 */
504 	u64 full_stripe_logical;
505 	struct btrfs_io_stripe stripes[];
506 };
507 
508 struct btrfs_device_info {
509 	struct btrfs_device *dev;
510 	u64 dev_offset;
511 	u64 max_avail;
512 	u64 total_avail;
513 };
514 
515 struct btrfs_raid_attr {
516 	u8 sub_stripes;		/* sub_stripes info for map */
517 	u8 dev_stripes;		/* stripes per dev */
518 	u8 devs_max;		/* max devs to use */
519 	u8 devs_min;		/* min devs needed */
520 	u8 tolerated_failures;	/* max tolerated fail devs */
521 	u8 devs_increment;	/* ndevs has to be a multiple of this */
522 	u8 ncopies;		/* how many copies to data has */
523 	u8 nparity;		/* number of stripes worth of bytes to store
524 				 * parity information */
525 	u8 mindev_error;	/* error code if min devs requisite is unmet */
526 	const char raid_name[8]; /* name of the raid */
527 	u64 bg_flag;		/* block group flag of the raid */
528 };
529 
530 extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
531 
532 struct map_lookup {
533 	u64 type;
534 	int io_align;
535 	int io_width;
536 	int num_stripes;
537 	int sub_stripes;
538 	int verified_stripes; /* For mount time dev extent verification */
539 	struct btrfs_io_stripe stripes[];
540 };
541 
542 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
543 			    (sizeof(struct btrfs_io_stripe) * (n)))
544 
545 struct btrfs_balance_args;
546 struct btrfs_balance_progress;
547 struct btrfs_balance_control {
548 	struct btrfs_balance_args data;
549 	struct btrfs_balance_args meta;
550 	struct btrfs_balance_args sys;
551 
552 	u64 flags;
553 
554 	struct btrfs_balance_progress stat;
555 };
556 
557 /*
558  * Search for a given device by the set parameters
559  */
560 struct btrfs_dev_lookup_args {
561 	u64 devid;
562 	u8 *uuid;
563 	u8 *fsid;
564 	bool missing;
565 };
566 
567 /* We have to initialize to -1 because BTRFS_DEV_REPLACE_DEVID is 0 */
568 #define BTRFS_DEV_LOOKUP_ARGS_INIT { .devid = (u64)-1 }
569 
570 #define BTRFS_DEV_LOOKUP_ARGS(name) \
571 	struct btrfs_dev_lookup_args name = BTRFS_DEV_LOOKUP_ARGS_INIT
572 
573 enum btrfs_map_op {
574 	BTRFS_MAP_READ,
575 	BTRFS_MAP_WRITE,
576 	BTRFS_MAP_GET_READ_MIRRORS,
577 };
578 
579 static inline enum btrfs_map_op btrfs_op(struct bio *bio)
580 {
581 	switch (bio_op(bio)) {
582 	case REQ_OP_WRITE:
583 	case REQ_OP_ZONE_APPEND:
584 		return BTRFS_MAP_WRITE;
585 	default:
586 		WARN_ON_ONCE(1);
587 		fallthrough;
588 	case REQ_OP_READ:
589 		return BTRFS_MAP_READ;
590 	}
591 }
592 
593 static inline unsigned long btrfs_chunk_item_size(int num_stripes)
594 {
595 	ASSERT(num_stripes);
596 	return sizeof(struct btrfs_chunk) +
597 		sizeof(struct btrfs_stripe) * (num_stripes - 1);
598 }
599 
600 /*
601  * Do the type safe converstion from stripe_nr to offset inside the chunk.
602  *
603  * @stripe_nr is u32, with left shift it can overflow u32 for chunks larger
604  * than 4G.  This does the proper type cast to avoid overflow.
605  */
606 static inline u64 btrfs_stripe_nr_to_offset(u32 stripe_nr)
607 {
608 	return (u64)stripe_nr << BTRFS_STRIPE_LEN_SHIFT;
609 }
610 
611 void btrfs_get_bioc(struct btrfs_io_context *bioc);
612 void btrfs_put_bioc(struct btrfs_io_context *bioc);
613 int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
614 		    u64 logical, u64 *length,
615 		    struct btrfs_io_context **bioc_ret,
616 		    struct btrfs_io_stripe *smap, int *mirror_num_ret);
617 int btrfs_map_repair_block(struct btrfs_fs_info *fs_info,
618 			   struct btrfs_io_stripe *smap, u64 logical,
619 			   u32 length, int mirror_num);
620 struct btrfs_discard_stripe *btrfs_map_discard(struct btrfs_fs_info *fs_info,
621 					       u64 logical, u64 *length_ret,
622 					       u32 *num_stripes);
623 int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
624 int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
625 struct btrfs_block_group *btrfs_create_chunk(struct btrfs_trans_handle *trans,
626 					    u64 type);
627 void btrfs_mapping_tree_free(struct extent_map_tree *tree);
628 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
629 		       blk_mode_t flags, void *holder);
630 struct btrfs_device *btrfs_scan_one_device(const char *path, blk_mode_t flags,
631 					   bool mount_arg_dev);
632 int btrfs_forget_devices(dev_t devt);
633 void btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
634 void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices);
635 void btrfs_assign_next_active_device(struct btrfs_device *device,
636 				     struct btrfs_device *this_dev);
637 struct btrfs_device *btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info,
638 						  u64 devid,
639 						  const char *devpath);
640 int btrfs_get_dev_args_from_path(struct btrfs_fs_info *fs_info,
641 				 struct btrfs_dev_lookup_args *args,
642 				 const char *path);
643 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
644 					const u64 *devid, const u8 *uuid,
645 					const char *path);
646 void btrfs_put_dev_args_from_path(struct btrfs_dev_lookup_args *args);
647 int btrfs_rm_device(struct btrfs_fs_info *fs_info,
648 		    struct btrfs_dev_lookup_args *args,
649 		    struct bdev_handle **bdev_handle);
650 void __exit btrfs_cleanup_fs_uuids(void);
651 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
652 int btrfs_grow_device(struct btrfs_trans_handle *trans,
653 		      struct btrfs_device *device, u64 new_size);
654 struct btrfs_device *btrfs_find_device(const struct btrfs_fs_devices *fs_devices,
655 				       const struct btrfs_dev_lookup_args *args);
656 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
657 int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
658 int btrfs_balance(struct btrfs_fs_info *fs_info,
659 		  struct btrfs_balance_control *bctl,
660 		  struct btrfs_ioctl_balance_args *bargs);
661 void btrfs_describe_block_groups(u64 flags, char *buf, u32 size_buf);
662 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
663 int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
664 int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
665 int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset);
666 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
667 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
668 int btrfs_uuid_scan_kthread(void *data);
669 bool btrfs_chunk_writeable(struct btrfs_fs_info *fs_info, u64 chunk_offset);
670 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
671 int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
672 			struct btrfs_ioctl_get_dev_stats *stats);
673 int btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
674 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
675 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans);
676 void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev);
677 void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev);
678 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev);
679 int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
680 			   u64 logical, u64 len);
681 unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
682 				    u64 logical);
683 u64 btrfs_calc_stripe_length(const struct extent_map *em);
684 int btrfs_nr_parity_stripes(u64 type);
685 int btrfs_chunk_alloc_add_chunk_item(struct btrfs_trans_handle *trans,
686 				     struct btrfs_block_group *bg);
687 int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
688 struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
689 				       u64 logical, u64 length);
690 void btrfs_release_disk_super(struct btrfs_super_block *super);
691 
692 static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
693 				      int index)
694 {
695 	atomic_inc(dev->dev_stat_values + index);
696 	/*
697 	 * This memory barrier orders stores updating statistics before stores
698 	 * updating dev_stats_ccnt.
699 	 *
700 	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
701 	 */
702 	smp_mb__before_atomic();
703 	atomic_inc(&dev->dev_stats_ccnt);
704 }
705 
706 static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
707 				      int index)
708 {
709 	return atomic_read(dev->dev_stat_values + index);
710 }
711 
712 static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
713 						int index)
714 {
715 	int ret;
716 
717 	ret = atomic_xchg(dev->dev_stat_values + index, 0);
718 	/*
719 	 * atomic_xchg implies a full memory barriers as per atomic_t.txt:
720 	 * - RMW operations that have a return value are fully ordered;
721 	 *
722 	 * This implicit memory barriers is paired with the smp_rmb in
723 	 * btrfs_run_dev_stats
724 	 */
725 	atomic_inc(&dev->dev_stats_ccnt);
726 	return ret;
727 }
728 
729 static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
730 				      int index, unsigned long val)
731 {
732 	atomic_set(dev->dev_stat_values + index, val);
733 	/*
734 	 * This memory barrier orders stores updating statistics before stores
735 	 * updating dev_stats_ccnt.
736 	 *
737 	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
738 	 */
739 	smp_mb__before_atomic();
740 	atomic_inc(&dev->dev_stats_ccnt);
741 }
742 
743 static inline const char *btrfs_dev_name(const struct btrfs_device *device)
744 {
745 	if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
746 		return "<missing disk>";
747 	else
748 		return rcu_str_deref(device->name);
749 }
750 
751 void btrfs_commit_device_sizes(struct btrfs_transaction *trans);
752 
753 struct list_head * __attribute_const__ btrfs_get_fs_uuids(void);
754 bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
755 					struct btrfs_device *failing_dev);
756 void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
757 			       struct block_device *bdev,
758 			       const char *device_path);
759 
760 enum btrfs_raid_types __attribute_const__ btrfs_bg_flags_to_raid_index(u64 flags);
761 int btrfs_bg_type_to_factor(u64 flags);
762 const char *btrfs_bg_type_to_raid_name(u64 flags);
763 int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
764 bool btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical);
765 
766 bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);
767 u8 *btrfs_sb_fsid_ptr(struct btrfs_super_block *sb);
768 
769 #endif
770