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