xref: /linux/fs/btrfs/volumes.h (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
1 /*
2  * Copyright (C) 2007 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18 
19 #ifndef __BTRFS_VOLUMES_
20 #define __BTRFS_VOLUMES_
21 
22 #include <linux/bio.h>
23 #include <linux/sort.h>
24 #include <linux/btrfs.h>
25 #include "async-thread.h"
26 
27 extern struct mutex uuid_mutex;
28 
29 #define BTRFS_STRIPE_LEN	SZ_64K
30 
31 struct buffer_head;
32 struct btrfs_pending_bios {
33 	struct bio *head;
34 	struct bio *tail;
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 struct btrfs_device {
51 	struct list_head dev_list;
52 	struct list_head dev_alloc_list;
53 	struct btrfs_fs_devices *fs_devices;
54 	struct btrfs_fs_info *fs_info;
55 
56 	struct rcu_string *name;
57 
58 	u64 generation;
59 
60 	spinlock_t io_lock ____cacheline_aligned;
61 	int running_pending;
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 	int writeable;
73 	int in_fs_metadata;
74 	int missing;
75 	int can_discard;
76 	int is_tgtdev_for_dev_replace;
77 
78 #ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
79 	seqcount_t data_seqcount;
80 #endif
81 
82 	/* the internal btrfs device id */
83 	u64 devid;
84 
85 	/* size of the device in memory */
86 	u64 total_bytes;
87 
88 	/* size of the device on disk */
89 	u64 disk_total_bytes;
90 
91 	/* bytes used */
92 	u64 bytes_used;
93 
94 	/* optimal io alignment for this device */
95 	u32 io_align;
96 
97 	/* optimal io width for this device */
98 	u32 io_width;
99 	/* type and info about this device */
100 	u64 type;
101 
102 	/* minimal io size for this device */
103 	u32 sector_size;
104 
105 	/* physical drive uuid (or lvm uuid) */
106 	u8 uuid[BTRFS_UUID_SIZE];
107 
108 	/*
109 	 * size of the device on the current transaction
110 	 *
111 	 * This variant is update when committing the transaction,
112 	 * and protected by device_list_mutex
113 	 */
114 	u64 commit_total_bytes;
115 
116 	/* bytes used on the current transaction */
117 	u64 commit_bytes_used;
118 	/*
119 	 * used to manage the device which is resized
120 	 *
121 	 * It is protected by chunk_lock.
122 	 */
123 	struct list_head resized_list;
124 
125 	/* for sending down flush barriers */
126 	struct bio *flush_bio;
127 	struct completion flush_wait;
128 
129 	/* per-device scrub information */
130 	struct scrub_ctx *scrub_device;
131 
132 	struct btrfs_work work;
133 	struct rcu_head rcu;
134 	struct work_struct rcu_work;
135 
136 	/* readahead state */
137 	spinlock_t reada_lock;
138 	atomic_t reada_in_flight;
139 	u64 reada_next;
140 	struct reada_zone *reada_curr_zone;
141 	struct radix_tree_root reada_zones;
142 	struct radix_tree_root reada_extents;
143 
144 	/* disk I/O failure stats. For detailed description refer to
145 	 * enum btrfs_dev_stat_values in ioctl.h */
146 	int dev_stats_valid;
147 
148 	/* Counter to record the change of device stats */
149 	atomic_t dev_stats_ccnt;
150 	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
151 };
152 
153 /*
154  * If we read those variants at the context of their own lock, we needn't
155  * use the following helpers, reading them directly is safe.
156  */
157 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
158 #define BTRFS_DEVICE_GETSET_FUNCS(name)					\
159 static inline u64							\
160 btrfs_device_get_##name(const struct btrfs_device *dev)			\
161 {									\
162 	u64 size;							\
163 	unsigned int seq;						\
164 									\
165 	do {								\
166 		seq = read_seqcount_begin(&dev->data_seqcount);		\
167 		size = dev->name;					\
168 	} while (read_seqcount_retry(&dev->data_seqcount, seq));	\
169 	return size;							\
170 }									\
171 									\
172 static inline void							\
173 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
174 {									\
175 	preempt_disable();						\
176 	write_seqcount_begin(&dev->data_seqcount);			\
177 	dev->name = size;						\
178 	write_seqcount_end(&dev->data_seqcount);			\
179 	preempt_enable();						\
180 }
181 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
182 #define BTRFS_DEVICE_GETSET_FUNCS(name)					\
183 static inline u64							\
184 btrfs_device_get_##name(const struct btrfs_device *dev)			\
185 {									\
186 	u64 size;							\
187 									\
188 	preempt_disable();						\
189 	size = dev->name;						\
190 	preempt_enable();						\
191 	return size;							\
192 }									\
193 									\
194 static inline void							\
195 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
196 {									\
197 	preempt_disable();						\
198 	dev->name = size;						\
199 	preempt_enable();						\
200 }
201 #else
202 #define BTRFS_DEVICE_GETSET_FUNCS(name)					\
203 static inline u64							\
204 btrfs_device_get_##name(const struct btrfs_device *dev)			\
205 {									\
206 	return dev->name;						\
207 }									\
208 									\
209 static inline void							\
210 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
211 {									\
212 	dev->name = size;						\
213 }
214 #endif
215 
216 BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
217 BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
218 BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
219 
220 struct btrfs_fs_devices {
221 	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
222 
223 	u64 num_devices;
224 	u64 open_devices;
225 	u64 rw_devices;
226 	u64 missing_devices;
227 	u64 total_rw_bytes;
228 	u64 total_devices;
229 	struct block_device *latest_bdev;
230 
231 	/* all of the devices in the FS, protected by a mutex
232 	 * so we can safely walk it to write out the supers without
233 	 * worrying about add/remove by the multi-device code.
234 	 * Scrubbing super can kick off supers writing by holding
235 	 * this mutex lock.
236 	 */
237 	struct mutex device_list_mutex;
238 	struct list_head devices;
239 
240 	struct list_head resized_devices;
241 	/* devices not currently being allocated */
242 	struct list_head alloc_list;
243 	struct list_head list;
244 
245 	struct btrfs_fs_devices *seed;
246 	int 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 	int 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 /*
265  * we need the mirror number and stripe index to be passed around
266  * the call chain while we are processing end_io (especially errors).
267  * Really, what we need is a btrfs_bio structure that has this info
268  * and is properly sized with its stripe array, but we're not there
269  * quite yet.  We have our own btrfs bioset, and all of the bios
270  * we allocate are actually btrfs_io_bios.  We'll cram as much of
271  * struct btrfs_bio as we can into this over time.
272  */
273 typedef void (btrfs_io_bio_end_io_t) (struct btrfs_io_bio *bio, int err);
274 struct btrfs_io_bio {
275 	unsigned int mirror_num;
276 	unsigned int stripe_index;
277 	u64 logical;
278 	u8 *csum;
279 	u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
280 	u8 *csum_allocated;
281 	btrfs_io_bio_end_io_t *end_io;
282 	struct bio bio;
283 };
284 
285 static inline struct btrfs_io_bio *btrfs_io_bio(struct bio *bio)
286 {
287 	return container_of(bio, struct btrfs_io_bio, bio);
288 }
289 
290 struct btrfs_bio_stripe {
291 	struct btrfs_device *dev;
292 	u64 physical;
293 	u64 length; /* only used for discard mappings */
294 };
295 
296 struct btrfs_bio;
297 typedef void (btrfs_bio_end_io_t) (struct btrfs_bio *bio, int err);
298 
299 struct btrfs_bio {
300 	refcount_t refs;
301 	atomic_t stripes_pending;
302 	struct btrfs_fs_info *fs_info;
303 	u64 map_type; /* get from map_lookup->type */
304 	bio_end_io_t *end_io;
305 	struct bio *orig_bio;
306 	unsigned long flags;
307 	void *private;
308 	atomic_t error;
309 	int max_errors;
310 	int num_stripes;
311 	int mirror_num;
312 	int num_tgtdevs;
313 	int *tgtdev_map;
314 	/*
315 	 * logical block numbers for the start of each stripe
316 	 * The last one or two are p/q.  These are sorted,
317 	 * so raid_map[0] is the start of our full stripe
318 	 */
319 	u64 *raid_map;
320 	struct btrfs_bio_stripe stripes[];
321 };
322 
323 struct btrfs_device_info {
324 	struct btrfs_device *dev;
325 	u64 dev_offset;
326 	u64 max_avail;
327 	u64 total_avail;
328 };
329 
330 struct btrfs_raid_attr {
331 	int sub_stripes;	/* sub_stripes info for map */
332 	int dev_stripes;	/* stripes per dev */
333 	int devs_max;		/* max devs to use */
334 	int devs_min;		/* min devs needed */
335 	int tolerated_failures; /* max tolerated fail devs */
336 	int devs_increment;	/* ndevs has to be a multiple of this */
337 	int ncopies;		/* how many copies to data has */
338 };
339 
340 extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
341 extern const int btrfs_raid_mindev_error[BTRFS_NR_RAID_TYPES];
342 extern const u64 btrfs_raid_group[BTRFS_NR_RAID_TYPES];
343 
344 struct map_lookup {
345 	u64 type;
346 	int io_align;
347 	int io_width;
348 	u64 stripe_len;
349 	int sector_size;
350 	int num_stripes;
351 	int sub_stripes;
352 	struct btrfs_bio_stripe stripes[];
353 };
354 
355 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
356 			    (sizeof(struct btrfs_bio_stripe) * (n)))
357 
358 struct btrfs_balance_args;
359 struct btrfs_balance_progress;
360 struct btrfs_balance_control {
361 	struct btrfs_fs_info *fs_info;
362 
363 	struct btrfs_balance_args data;
364 	struct btrfs_balance_args meta;
365 	struct btrfs_balance_args sys;
366 
367 	u64 flags;
368 
369 	struct btrfs_balance_progress stat;
370 };
371 
372 enum btrfs_map_op {
373 	BTRFS_MAP_READ,
374 	BTRFS_MAP_WRITE,
375 	BTRFS_MAP_DISCARD,
376 	BTRFS_MAP_GET_READ_MIRRORS,
377 };
378 
379 static inline enum btrfs_map_op btrfs_op(struct bio *bio)
380 {
381 	switch (bio_op(bio)) {
382 	case REQ_OP_DISCARD:
383 		return BTRFS_MAP_DISCARD;
384 	case REQ_OP_WRITE:
385 		return BTRFS_MAP_WRITE;
386 	default:
387 		WARN_ON_ONCE(1);
388 	case REQ_OP_READ:
389 		return BTRFS_MAP_READ;
390 	}
391 }
392 
393 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
394 				   u64 end, u64 *length);
395 void btrfs_get_bbio(struct btrfs_bio *bbio);
396 void btrfs_put_bbio(struct btrfs_bio *bbio);
397 int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
398 		    u64 logical, u64 *length,
399 		    struct btrfs_bio **bbio_ret, int mirror_num);
400 int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
401 		     u64 logical, u64 *length,
402 		     struct btrfs_bio **bbio_ret);
403 int btrfs_rmap_block(struct btrfs_fs_info *fs_info,
404 		     u64 chunk_start, u64 physical, u64 devid,
405 		     u64 **logical, int *naddrs, int *stripe_len);
406 int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
407 int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
408 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
409 		      struct btrfs_fs_info *fs_info, u64 type);
410 void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
411 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
412 int btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
413 		  int mirror_num, int async_submit);
414 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
415 		       fmode_t flags, void *holder);
416 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
417 			  struct btrfs_fs_devices **fs_devices_ret);
418 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
419 void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices, int step);
420 void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
421 		struct btrfs_device *device, struct btrfs_device *this_dev);
422 int btrfs_find_device_missing_or_by_path(struct btrfs_fs_info *fs_info,
423 					 const char *device_path,
424 					 struct btrfs_device **device);
425 int btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info, u64 devid,
426 					 const char *devpath,
427 					 struct btrfs_device **device);
428 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
429 					const u64 *devid,
430 					const u8 *uuid);
431 int btrfs_rm_device(struct btrfs_fs_info *fs_info,
432 		    const char *device_path, u64 devid);
433 void btrfs_cleanup_fs_uuids(void);
434 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
435 int btrfs_grow_device(struct btrfs_trans_handle *trans,
436 		      struct btrfs_device *device, u64 new_size);
437 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
438 				       u8 *uuid, u8 *fsid);
439 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
440 int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
441 int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
442 				  const char *device_path,
443 				  struct btrfs_device *srcdev,
444 				  struct btrfs_device **device_out);
445 int btrfs_balance(struct btrfs_balance_control *bctl,
446 		  struct btrfs_ioctl_balance_args *bargs);
447 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
448 int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
449 int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
450 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
451 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
452 int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info);
453 int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset);
454 int find_free_dev_extent_start(struct btrfs_transaction *transaction,
455 			 struct btrfs_device *device, u64 num_bytes,
456 			 u64 search_start, u64 *start, u64 *max_avail);
457 int find_free_dev_extent(struct btrfs_trans_handle *trans,
458 			 struct btrfs_device *device, u64 num_bytes,
459 			 u64 *start, u64 *max_avail);
460 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
461 int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
462 			struct btrfs_ioctl_get_dev_stats *stats);
463 void btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
464 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
465 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
466 			struct btrfs_fs_info *fs_info);
467 void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_fs_info *fs_info,
468 					struct btrfs_device *srcdev);
469 void btrfs_rm_dev_replace_free_srcdev(struct btrfs_fs_info *fs_info,
470 				      struct btrfs_device *srcdev);
471 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
472 				      struct btrfs_device *tgtdev);
473 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
474 					      struct btrfs_device *tgtdev);
475 void btrfs_scratch_superblocks(struct block_device *bdev, const char *device_path);
476 int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
477 			   u64 logical, u64 len, int mirror_num);
478 unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
479 				    struct btrfs_mapping_tree *map_tree,
480 				    u64 logical);
481 int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
482 				struct btrfs_fs_info *fs_info,
483 				u64 chunk_offset, u64 chunk_size);
484 int btrfs_remove_chunk(struct btrfs_trans_handle *trans,
485 		       struct btrfs_fs_info *fs_info, u64 chunk_offset);
486 
487 static inline int btrfs_dev_stats_dirty(struct btrfs_device *dev)
488 {
489 	return atomic_read(&dev->dev_stats_ccnt);
490 }
491 
492 static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
493 				      int index)
494 {
495 	atomic_inc(dev->dev_stat_values + index);
496 	smp_mb__before_atomic();
497 	atomic_inc(&dev->dev_stats_ccnt);
498 }
499 
500 static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
501 				      int index)
502 {
503 	return atomic_read(dev->dev_stat_values + index);
504 }
505 
506 static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
507 						int index)
508 {
509 	int ret;
510 
511 	ret = atomic_xchg(dev->dev_stat_values + index, 0);
512 	smp_mb__before_atomic();
513 	atomic_inc(&dev->dev_stats_ccnt);
514 	return ret;
515 }
516 
517 static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
518 				      int index, unsigned long val)
519 {
520 	atomic_set(dev->dev_stat_values + index, val);
521 	smp_mb__before_atomic();
522 	atomic_inc(&dev->dev_stats_ccnt);
523 }
524 
525 static inline void btrfs_dev_stat_reset(struct btrfs_device *dev,
526 					int index)
527 {
528 	btrfs_dev_stat_set(dev, index, 0);
529 }
530 
531 void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info);
532 void btrfs_update_commit_device_bytes_used(struct btrfs_fs_info *fs_info,
533 					struct btrfs_transaction *transaction);
534 
535 struct list_head *btrfs_get_fs_uuids(void);
536 void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info);
537 void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info);
538 
539 #endif
540