xref: /openbmc/linux/fs/btrfs/volumes.h (revision 9a6b55ac)
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 struct buffer_head;
21 
22 struct btrfs_io_geometry {
23 	/* remaining bytes before crossing a stripe */
24 	u64 len;
25 	/* offset of logical address in chunk */
26 	u64 offset;
27 	/* length of single IO stripe */
28 	u64 stripe_len;
29 	/* number of stripe where address falls */
30 	u64 stripe_nr;
31 	/* offset of address in stripe */
32 	u64 stripe_offset;
33 	/* offset of raid56 stripe into the chunk */
34 	u64 raid56_stripe_offset;
35 };
36 
37 /*
38  * Use sequence counter to get consistent device stat data on
39  * 32-bit processors.
40  */
41 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
42 #include <linux/seqlock.h>
43 #define __BTRFS_NEED_DEVICE_DATA_ORDERED
44 #define btrfs_device_data_ordered_init(device)	\
45 	seqcount_init(&device->data_seqcount)
46 #else
47 #define btrfs_device_data_ordered_init(device) do { } while (0)
48 #endif
49 
50 #define BTRFS_DEV_STATE_WRITEABLE	(0)
51 #define BTRFS_DEV_STATE_IN_FS_METADATA	(1)
52 #define BTRFS_DEV_STATE_MISSING		(2)
53 #define BTRFS_DEV_STATE_REPLACE_TGT	(3)
54 #define BTRFS_DEV_STATE_FLUSH_SENT	(4)
55 
56 struct btrfs_device {
57 	struct list_head dev_list; /* device_list_mutex */
58 	struct list_head dev_alloc_list; /* chunk mutex */
59 	struct list_head post_commit_list; /* chunk mutex */
60 	struct btrfs_fs_devices *fs_devices;
61 	struct btrfs_fs_info *fs_info;
62 
63 	struct rcu_string *name;
64 
65 	u64 generation;
66 
67 	struct block_device *bdev;
68 
69 	/* the mode sent to blkdev_get */
70 	fmode_t mode;
71 
72 	unsigned long dev_state;
73 	blk_status_t last_flush_error;
74 
75 #ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
76 	seqcount_t data_seqcount;
77 #endif
78 
79 	/* the internal btrfs device id */
80 	u64 devid;
81 
82 	/* size of the device in memory */
83 	u64 total_bytes;
84 
85 	/* size of the device on disk */
86 	u64 disk_total_bytes;
87 
88 	/* bytes used */
89 	u64 bytes_used;
90 
91 	/* optimal io alignment for this device */
92 	u32 io_align;
93 
94 	/* optimal io width for this device */
95 	u32 io_width;
96 	/* type and info about this device */
97 	u64 type;
98 
99 	/* minimal io size for this device */
100 	u32 sector_size;
101 
102 	/* physical drive uuid (or lvm uuid) */
103 	u8 uuid[BTRFS_UUID_SIZE];
104 
105 	/*
106 	 * size of the device on the current transaction
107 	 *
108 	 * This variant is update when committing the transaction,
109 	 * and protected by chunk mutex
110 	 */
111 	u64 commit_total_bytes;
112 
113 	/* bytes used on the current transaction */
114 	u64 commit_bytes_used;
115 
116 	/* for sending down flush barriers */
117 	struct bio *flush_bio;
118 	struct completion flush_wait;
119 
120 	/* per-device scrub information */
121 	struct scrub_ctx *scrub_ctx;
122 
123 	struct btrfs_work work;
124 
125 	/* readahead state */
126 	atomic_t reada_in_flight;
127 	u64 reada_next;
128 	struct reada_zone *reada_curr_zone;
129 	struct radix_tree_root reada_zones;
130 	struct radix_tree_root reada_extents;
131 
132 	/* disk I/O failure stats. For detailed description refer to
133 	 * enum btrfs_dev_stat_values in ioctl.h */
134 	int dev_stats_valid;
135 
136 	/* Counter to record the change of device stats */
137 	atomic_t dev_stats_ccnt;
138 	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
139 
140 	struct extent_io_tree alloc_state;
141 };
142 
143 /*
144  * If we read those variants at the context of their own lock, we needn't
145  * use the following helpers, reading them directly is safe.
146  */
147 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
148 #define BTRFS_DEVICE_GETSET_FUNCS(name)					\
149 static inline u64							\
150 btrfs_device_get_##name(const struct btrfs_device *dev)			\
151 {									\
152 	u64 size;							\
153 	unsigned int seq;						\
154 									\
155 	do {								\
156 		seq = read_seqcount_begin(&dev->data_seqcount);		\
157 		size = dev->name;					\
158 	} while (read_seqcount_retry(&dev->data_seqcount, seq));	\
159 	return size;							\
160 }									\
161 									\
162 static inline void							\
163 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
164 {									\
165 	preempt_disable();						\
166 	write_seqcount_begin(&dev->data_seqcount);			\
167 	dev->name = size;						\
168 	write_seqcount_end(&dev->data_seqcount);			\
169 	preempt_enable();						\
170 }
171 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
172 #define BTRFS_DEVICE_GETSET_FUNCS(name)					\
173 static inline u64							\
174 btrfs_device_get_##name(const struct btrfs_device *dev)			\
175 {									\
176 	u64 size;							\
177 									\
178 	preempt_disable();						\
179 	size = dev->name;						\
180 	preempt_enable();						\
181 	return size;							\
182 }									\
183 									\
184 static inline void							\
185 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
186 {									\
187 	preempt_disable();						\
188 	dev->name = size;						\
189 	preempt_enable();						\
190 }
191 #else
192 #define BTRFS_DEVICE_GETSET_FUNCS(name)					\
193 static inline u64							\
194 btrfs_device_get_##name(const struct btrfs_device *dev)			\
195 {									\
196 	return dev->name;						\
197 }									\
198 									\
199 static inline void							\
200 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
201 {									\
202 	dev->name = size;						\
203 }
204 #endif
205 
206 BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
207 BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
208 BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
209 
210 struct btrfs_fs_devices {
211 	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
212 	u8 metadata_uuid[BTRFS_FSID_SIZE];
213 	bool fsid_change;
214 	struct list_head fs_list;
215 
216 	u64 num_devices;
217 	u64 open_devices;
218 	u64 rw_devices;
219 	u64 missing_devices;
220 	u64 total_rw_bytes;
221 	u64 total_devices;
222 
223 	/* Highest generation number of seen devices */
224 	u64 latest_generation;
225 
226 	struct block_device *latest_bdev;
227 
228 	/* all of the devices in the FS, protected by a mutex
229 	 * so we can safely walk it to write out the supers without
230 	 * worrying about add/remove by the multi-device code.
231 	 * Scrubbing super can kick off supers writing by holding
232 	 * this mutex lock.
233 	 */
234 	struct mutex device_list_mutex;
235 
236 	/* List of all devices, protected by device_list_mutex */
237 	struct list_head devices;
238 
239 	/*
240 	 * Devices which can satisfy space allocation. Protected by
241 	 * chunk_mutex
242 	 */
243 	struct list_head alloc_list;
244 
245 	struct btrfs_fs_devices *seed;
246 	bool seeding;
247 
248 	int opened;
249 
250 	/* set when we find or add a device that doesn't have the
251 	 * nonrot flag set
252 	 */
253 	bool rotating;
254 
255 	struct btrfs_fs_info *fs_info;
256 	/* sysfs kobjects */
257 	struct kobject fsid_kobj;
258 	struct kobject *device_dir_kobj;
259 	struct completion kobj_unregister;
260 };
261 
262 #define BTRFS_BIO_INLINE_CSUM_SIZE	64
263 
264 #define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info)	\
265 			- sizeof(struct btrfs_chunk))		\
266 			/ sizeof(struct btrfs_stripe) + 1)
267 
268 #define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE	\
269 				- 2 * sizeof(struct btrfs_disk_key)	\
270 				- 2 * sizeof(struct btrfs_chunk))	\
271 				/ sizeof(struct btrfs_stripe) + 1)
272 
273 /*
274  * we need the mirror number and stripe index to be passed around
275  * the call chain while we are processing end_io (especially errors).
276  * Really, what we need is a btrfs_bio structure that has this info
277  * and is properly sized with its stripe array, but we're not there
278  * quite yet.  We have our own btrfs bioset, and all of the bios
279  * we allocate are actually btrfs_io_bios.  We'll cram as much of
280  * struct btrfs_bio as we can into this over time.
281  */
282 struct btrfs_io_bio {
283 	unsigned int mirror_num;
284 	unsigned int stripe_index;
285 	u64 logical;
286 	u8 *csum;
287 	u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
288 	struct bvec_iter iter;
289 	/*
290 	 * This member must come last, bio_alloc_bioset will allocate enough
291 	 * bytes for entire btrfs_io_bio but relies on bio being last.
292 	 */
293 	struct bio bio;
294 };
295 
296 static inline struct btrfs_io_bio *btrfs_io_bio(struct bio *bio)
297 {
298 	return container_of(bio, struct btrfs_io_bio, bio);
299 }
300 
301 static inline void btrfs_io_bio_free_csum(struct btrfs_io_bio *io_bio)
302 {
303 	if (io_bio->csum != io_bio->csum_inline) {
304 		kfree(io_bio->csum);
305 		io_bio->csum = NULL;
306 	}
307 }
308 
309 struct btrfs_bio_stripe {
310 	struct btrfs_device *dev;
311 	u64 physical;
312 	u64 length; /* only used for discard mappings */
313 };
314 
315 struct btrfs_bio {
316 	refcount_t refs;
317 	atomic_t stripes_pending;
318 	struct btrfs_fs_info *fs_info;
319 	u64 map_type; /* get from map_lookup->type */
320 	bio_end_io_t *end_io;
321 	struct bio *orig_bio;
322 	void *private;
323 	atomic_t error;
324 	int max_errors;
325 	int num_stripes;
326 	int mirror_num;
327 	int num_tgtdevs;
328 	int *tgtdev_map;
329 	/*
330 	 * logical block numbers for the start of each stripe
331 	 * The last one or two are p/q.  These are sorted,
332 	 * so raid_map[0] is the start of our full stripe
333 	 */
334 	u64 *raid_map;
335 	struct btrfs_bio_stripe stripes[];
336 };
337 
338 struct btrfs_device_info {
339 	struct btrfs_device *dev;
340 	u64 dev_offset;
341 	u64 max_avail;
342 	u64 total_avail;
343 };
344 
345 struct btrfs_raid_attr {
346 	u8 sub_stripes;		/* sub_stripes info for map */
347 	u8 dev_stripes;		/* stripes per dev */
348 	u8 devs_max;		/* max devs to use */
349 	u8 devs_min;		/* min devs needed */
350 	u8 tolerated_failures;	/* max tolerated fail devs */
351 	u8 devs_increment;	/* ndevs has to be a multiple of this */
352 	u8 ncopies;		/* how many copies to data has */
353 	u8 nparity;		/* number of stripes worth of bytes to store
354 				 * parity information */
355 	u8 mindev_error;	/* error code if min devs requisite is unmet */
356 	const char raid_name[8]; /* name of the raid */
357 	u64 bg_flag;		/* block group flag of the raid */
358 };
359 
360 extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
361 
362 struct map_lookup {
363 	u64 type;
364 	int io_align;
365 	int io_width;
366 	u64 stripe_len;
367 	int num_stripes;
368 	int sub_stripes;
369 	int verified_stripes; /* For mount time dev extent verification */
370 	struct btrfs_bio_stripe stripes[];
371 };
372 
373 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
374 			    (sizeof(struct btrfs_bio_stripe) * (n)))
375 
376 struct btrfs_balance_args;
377 struct btrfs_balance_progress;
378 struct btrfs_balance_control {
379 	struct btrfs_balance_args data;
380 	struct btrfs_balance_args meta;
381 	struct btrfs_balance_args sys;
382 
383 	u64 flags;
384 
385 	struct btrfs_balance_progress stat;
386 };
387 
388 enum btrfs_map_op {
389 	BTRFS_MAP_READ,
390 	BTRFS_MAP_WRITE,
391 	BTRFS_MAP_DISCARD,
392 	BTRFS_MAP_GET_READ_MIRRORS,
393 };
394 
395 static inline enum btrfs_map_op btrfs_op(struct bio *bio)
396 {
397 	switch (bio_op(bio)) {
398 	case REQ_OP_DISCARD:
399 		return BTRFS_MAP_DISCARD;
400 	case REQ_OP_WRITE:
401 		return BTRFS_MAP_WRITE;
402 	default:
403 		WARN_ON_ONCE(1);
404 		/* fall through */
405 	case REQ_OP_READ:
406 		return BTRFS_MAP_READ;
407 	}
408 }
409 
410 void btrfs_get_bbio(struct btrfs_bio *bbio);
411 void btrfs_put_bbio(struct btrfs_bio *bbio);
412 int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
413 		    u64 logical, u64 *length,
414 		    struct btrfs_bio **bbio_ret, int mirror_num);
415 int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
416 		     u64 logical, u64 *length,
417 		     struct btrfs_bio **bbio_ret);
418 int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
419 		u64 logical, u64 len, struct btrfs_io_geometry *io_geom);
420 int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
421 		     u64 physical, u64 **logical, int *naddrs, int *stripe_len);
422 int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
423 int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
424 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 type);
425 void btrfs_mapping_tree_free(struct extent_map_tree *tree);
426 blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
427 			   int mirror_num);
428 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
429 		       fmode_t flags, void *holder);
430 struct btrfs_device *btrfs_scan_one_device(const char *path,
431 					   fmode_t flags, void *holder);
432 int btrfs_forget_devices(const char *path);
433 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
434 void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step);
435 void btrfs_assign_next_active_device(struct btrfs_device *device,
436 				     struct btrfs_device *this_dev);
437 struct btrfs_device *btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info,
438 						  u64 devid,
439 						  const char *devpath);
440 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
441 					const u64 *devid,
442 					const u8 *uuid);
443 void btrfs_free_device(struct btrfs_device *device);
444 int btrfs_rm_device(struct btrfs_fs_info *fs_info,
445 		    const char *device_path, u64 devid);
446 void __exit btrfs_cleanup_fs_uuids(void);
447 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
448 int btrfs_grow_device(struct btrfs_trans_handle *trans,
449 		      struct btrfs_device *device, u64 new_size);
450 struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices,
451 				       u64 devid, u8 *uuid, u8 *fsid, bool seed);
452 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
453 int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
454 int btrfs_balance(struct btrfs_fs_info *fs_info,
455 		  struct btrfs_balance_control *bctl,
456 		  struct btrfs_ioctl_balance_args *bargs);
457 void btrfs_describe_block_groups(u64 flags, char *buf, u32 size_buf);
458 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
459 int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
460 int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
461 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
462 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
463 int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info);
464 int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset);
465 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
466 			 u64 *start, u64 *max_avail);
467 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
468 int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
469 			struct btrfs_ioctl_get_dev_stats *stats);
470 void btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
471 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
472 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans);
473 void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev);
474 void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev);
475 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev);
476 void btrfs_scratch_superblocks(struct block_device *bdev, const char *device_path);
477 int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
478 			   u64 logical, u64 len);
479 unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
480 				    u64 logical);
481 int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
482 			     u64 chunk_offset, u64 chunk_size);
483 int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
484 struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
485 				       u64 logical, u64 length);
486 
487 static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
488 				      int index)
489 {
490 	atomic_inc(dev->dev_stat_values + index);
491 	/*
492 	 * This memory barrier orders stores updating statistics before stores
493 	 * updating dev_stats_ccnt.
494 	 *
495 	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
496 	 */
497 	smp_mb__before_atomic();
498 	atomic_inc(&dev->dev_stats_ccnt);
499 }
500 
501 static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
502 				      int index)
503 {
504 	return atomic_read(dev->dev_stat_values + index);
505 }
506 
507 static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
508 						int index)
509 {
510 	int ret;
511 
512 	ret = atomic_xchg(dev->dev_stat_values + index, 0);
513 	/*
514 	 * atomic_xchg implies a full memory barriers as per atomic_t.txt:
515 	 * - RMW operations that have a return value are fully ordered;
516 	 *
517 	 * This implicit memory barriers is paired with the smp_rmb in
518 	 * btrfs_run_dev_stats
519 	 */
520 	atomic_inc(&dev->dev_stats_ccnt);
521 	return ret;
522 }
523 
524 static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
525 				      int index, unsigned long val)
526 {
527 	atomic_set(dev->dev_stat_values + index, val);
528 	/*
529 	 * This memory barrier orders stores updating statistics before stores
530 	 * updating dev_stats_ccnt.
531 	 *
532 	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
533 	 */
534 	smp_mb__before_atomic();
535 	atomic_inc(&dev->dev_stats_ccnt);
536 }
537 
538 /*
539  * Convert block group flags (BTRFS_BLOCK_GROUP_*) to btrfs_raid_types, which
540  * can be used as index to access btrfs_raid_array[].
541  */
542 static inline enum btrfs_raid_types btrfs_bg_flags_to_raid_index(u64 flags)
543 {
544 	if (flags & BTRFS_BLOCK_GROUP_RAID10)
545 		return BTRFS_RAID_RAID10;
546 	else if (flags & BTRFS_BLOCK_GROUP_RAID1)
547 		return BTRFS_RAID_RAID1;
548 	else if (flags & BTRFS_BLOCK_GROUP_RAID1C3)
549 		return BTRFS_RAID_RAID1C3;
550 	else if (flags & BTRFS_BLOCK_GROUP_RAID1C4)
551 		return BTRFS_RAID_RAID1C4;
552 	else if (flags & BTRFS_BLOCK_GROUP_DUP)
553 		return BTRFS_RAID_DUP;
554 	else if (flags & BTRFS_BLOCK_GROUP_RAID0)
555 		return BTRFS_RAID_RAID0;
556 	else if (flags & BTRFS_BLOCK_GROUP_RAID5)
557 		return BTRFS_RAID_RAID5;
558 	else if (flags & BTRFS_BLOCK_GROUP_RAID6)
559 		return BTRFS_RAID_RAID6;
560 
561 	return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
562 }
563 
564 void btrfs_commit_device_sizes(struct btrfs_transaction *trans);
565 
566 struct list_head * __attribute_const__ btrfs_get_fs_uuids(void);
567 void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info);
568 void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info);
569 bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
570 					struct btrfs_device *failing_dev);
571 
572 int btrfs_bg_type_to_factor(u64 flags);
573 const char *btrfs_bg_type_to_raid_name(u64 flags);
574 int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
575 
576 #endif
577