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v6.2
  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
 18extern struct mutex uuid_mutex;
 19
 20#define BTRFS_STRIPE_LEN	SZ_64K
 21
 22/* Used by sanity check for btrfs_raid_types. */
 23#define const_ffs(n) (__builtin_ctzll(n) + 1)
 24
 25/*
 26 * The conversion from BTRFS_BLOCK_GROUP_* bits to btrfs_raid_type requires
 27 * RAID0 always to be the lowest profile bit.
 28 * Although it's part of on-disk format and should never change, do extra
 29 * compile-time sanity checks.
 30 */
 31static_assert(const_ffs(BTRFS_BLOCK_GROUP_RAID0) <
 32	      const_ffs(BTRFS_BLOCK_GROUP_PROFILE_MASK & ~BTRFS_BLOCK_GROUP_RAID0));
 33static_assert(const_ilog2(BTRFS_BLOCK_GROUP_RAID0) >
 34	      ilog2(BTRFS_BLOCK_GROUP_TYPE_MASK));
 35
 36/* ilog2() can handle both constants and variables */
 37#define BTRFS_BG_FLAG_TO_INDEX(profile)					\
 38	ilog2((profile) >> (ilog2(BTRFS_BLOCK_GROUP_RAID0) - 1))
 39
 40enum btrfs_raid_types {
 41	/* SINGLE is the special one as it doesn't have on-disk bit. */
 42	BTRFS_RAID_SINGLE  = 0,
 43
 44	BTRFS_RAID_RAID0   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID0),
 45	BTRFS_RAID_RAID1   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1),
 46	BTRFS_RAID_DUP	   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_DUP),
 47	BTRFS_RAID_RAID10  = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID10),
 48	BTRFS_RAID_RAID5   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID5),
 49	BTRFS_RAID_RAID6   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID6),
 50	BTRFS_RAID_RAID1C3 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1C3),
 51	BTRFS_RAID_RAID1C4 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1C4),
 52
 53	BTRFS_NR_RAID_TYPES
 54};
 55
 56struct btrfs_io_geometry {
 57	/* remaining bytes before crossing a stripe */
 58	u64 len;
 59	/* offset of logical address in chunk */
 60	u64 offset;
 61	/* length of single IO stripe */
 62	u32 stripe_len;
 63	/* offset of address in stripe */
 64	u32 stripe_offset;
 65	/* number of stripe where address falls */
 66	u64 stripe_nr;
 
 
 67	/* offset of raid56 stripe into the chunk */
 68	u64 raid56_stripe_offset;
 69};
 70
 71/*
 72 * Use sequence counter to get consistent device stat data on
 73 * 32-bit processors.
 74 */
 75#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
 76#include <linux/seqlock.h>
 77#define __BTRFS_NEED_DEVICE_DATA_ORDERED
 78#define btrfs_device_data_ordered_init(device)	\
 79	seqcount_init(&device->data_seqcount)
 80#else
 81#define btrfs_device_data_ordered_init(device) do { } while (0)
 82#endif
 83
 84#define BTRFS_DEV_STATE_WRITEABLE	(0)
 85#define BTRFS_DEV_STATE_IN_FS_METADATA	(1)
 86#define BTRFS_DEV_STATE_MISSING		(2)
 87#define BTRFS_DEV_STATE_REPLACE_TGT	(3)
 88#define BTRFS_DEV_STATE_FLUSH_SENT	(4)
 89#define BTRFS_DEV_STATE_NO_READA	(5)
 90
 91struct btrfs_zoned_device_info;
 92
 93struct btrfs_device {
 94	struct list_head dev_list; /* device_list_mutex */
 95	struct list_head dev_alloc_list; /* chunk mutex */
 96	struct list_head post_commit_list; /* chunk mutex */
 97	struct btrfs_fs_devices *fs_devices;
 98	struct btrfs_fs_info *fs_info;
 99
100	struct rcu_string __rcu *name;
101
102	u64 generation;
103
104	struct block_device *bdev;
105
106	struct btrfs_zoned_device_info *zone_info;
107
108	/* the mode sent to blkdev_get */
109	fmode_t mode;
110
111	/*
112	 * Device's major-minor number. Must be set even if the device is not
113	 * opened (bdev == NULL), unless the device is missing.
114	 */
115	dev_t devt;
116	unsigned long dev_state;
117	blk_status_t last_flush_error;
118
119#ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
120	seqcount_t data_seqcount;
121#endif
122
123	/* the internal btrfs device id */
124	u64 devid;
125
126	/* size of the device in memory */
127	u64 total_bytes;
128
129	/* size of the device on disk */
130	u64 disk_total_bytes;
131
132	/* bytes used */
133	u64 bytes_used;
134
135	/* optimal io alignment for this device */
136	u32 io_align;
137
138	/* optimal io width for this device */
139	u32 io_width;
140	/* type and info about this device */
141	u64 type;
142
143	/* minimal io size for this device */
144	u32 sector_size;
145
146	/* physical drive uuid (or lvm uuid) */
147	u8 uuid[BTRFS_UUID_SIZE];
148
149	/*
150	 * size of the device on the current transaction
151	 *
152	 * This variant is update when committing the transaction,
153	 * and protected by chunk mutex
154	 */
155	u64 commit_total_bytes;
156
157	/* bytes used on the current transaction */
158	u64 commit_bytes_used;
159
160	/* Bio used for flushing device barriers */
161	struct bio flush_bio;
162	struct completion flush_wait;
163
164	/* per-device scrub information */
165	struct scrub_ctx *scrub_ctx;
166
 
 
 
 
 
 
 
167	/* disk I/O failure stats. For detailed description refer to
168	 * enum btrfs_dev_stat_values in ioctl.h */
169	int dev_stats_valid;
170
171	/* Counter to record the change of device stats */
172	atomic_t dev_stats_ccnt;
173	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
174
175	struct extent_io_tree alloc_state;
176
177	struct completion kobj_unregister;
178	/* For sysfs/FSID/devinfo/devid/ */
179	struct kobject devid_kobj;
180
181	/* Bandwidth limit for scrub, in bytes */
182	u64 scrub_speed_max;
183};
184
185/*
186 * Block group or device which contains an active swapfile. Used for preventing
187 * unsafe operations while a swapfile is active.
188 *
189 * These are sorted on (ptr, inode) (note that a block group or device can
190 * contain more than one swapfile). We compare the pointer values because we
191 * don't actually care what the object is, we just need a quick check whether
192 * the object exists in the rbtree.
193 */
194struct btrfs_swapfile_pin {
195	struct rb_node node;
196	void *ptr;
197	struct inode *inode;
198	/*
199	 * If true, ptr points to a struct btrfs_block_group. Otherwise, ptr
200	 * points to a struct btrfs_device.
201	 */
202	bool is_block_group;
203	/*
204	 * Only used when 'is_block_group' is true and it is the number of
205	 * extents used by a swapfile for this block group ('ptr' field).
206	 */
207	int bg_extent_count;
208};
209
210/*
211 * If we read those variants at the context of their own lock, we needn't
212 * use the following helpers, reading them directly is safe.
213 */
214#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
215#define BTRFS_DEVICE_GETSET_FUNCS(name)					\
216static inline u64							\
217btrfs_device_get_##name(const struct btrfs_device *dev)			\
218{									\
219	u64 size;							\
220	unsigned int seq;						\
221									\
222	do {								\
223		seq = read_seqcount_begin(&dev->data_seqcount);		\
224		size = dev->name;					\
225	} while (read_seqcount_retry(&dev->data_seqcount, seq));	\
226	return size;							\
227}									\
228									\
229static inline void							\
230btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
231{									\
232	preempt_disable();						\
233	write_seqcount_begin(&dev->data_seqcount);			\
234	dev->name = size;						\
235	write_seqcount_end(&dev->data_seqcount);			\
236	preempt_enable();						\
237}
238#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
239#define BTRFS_DEVICE_GETSET_FUNCS(name)					\
240static inline u64							\
241btrfs_device_get_##name(const struct btrfs_device *dev)			\
242{									\
243	u64 size;							\
244									\
245	preempt_disable();						\
246	size = dev->name;						\
247	preempt_enable();						\
248	return size;							\
249}									\
250									\
251static inline void							\
252btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
253{									\
254	preempt_disable();						\
255	dev->name = size;						\
256	preempt_enable();						\
257}
258#else
259#define BTRFS_DEVICE_GETSET_FUNCS(name)					\
260static inline u64							\
261btrfs_device_get_##name(const struct btrfs_device *dev)			\
262{									\
263	return dev->name;						\
264}									\
265									\
266static inline void							\
267btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
268{									\
269	dev->name = size;						\
270}
271#endif
272
273BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
274BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
275BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
276
277enum btrfs_chunk_allocation_policy {
278	BTRFS_CHUNK_ALLOC_REGULAR,
279	BTRFS_CHUNK_ALLOC_ZONED,
280};
281
282/*
283 * Read policies for mirrored block group profiles, read picks the stripe based
284 * on these policies.
285 */
286enum btrfs_read_policy {
287	/* Use process PID to choose the stripe */
288	BTRFS_READ_POLICY_PID,
289	BTRFS_NR_READ_POLICY,
290};
291
292struct btrfs_fs_devices {
293	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
294	u8 metadata_uuid[BTRFS_FSID_SIZE];
295	bool fsid_change;
296	struct list_head fs_list;
297
298	/*
299	 * Number of devices under this fsid including missing and
300	 * replace-target device and excludes seed devices.
301	 */
302	u64 num_devices;
303
304	/*
305	 * The number of devices that successfully opened, including
306	 * replace-target, excludes seed devices.
307	 */
308	u64 open_devices;
309
310	/* The number of devices that are under the chunk allocation list. */
311	u64 rw_devices;
312
313	/* Count of missing devices under this fsid excluding seed device. */
314	u64 missing_devices;
315	u64 total_rw_bytes;
316
317	/*
318	 * Count of devices from btrfs_super_block::num_devices for this fsid,
319	 * which includes the seed device, excludes the transient replace-target
320	 * device.
321	 */
322	u64 total_devices;
323
324	/* Highest generation number of seen devices */
325	u64 latest_generation;
326
327	/*
328	 * The mount device or a device with highest generation after removal
329	 * or replace.
330	 */
331	struct btrfs_device *latest_dev;
332
333	/* all of the devices in the FS, protected by a mutex
334	 * so we can safely walk it to write out the supers without
335	 * worrying about add/remove by the multi-device code.
336	 * Scrubbing super can kick off supers writing by holding
337	 * this mutex lock.
338	 */
339	struct mutex device_list_mutex;
340
341	/* List of all devices, protected by device_list_mutex */
342	struct list_head devices;
343
344	/*
345	 * Devices which can satisfy space allocation. Protected by
346	 * chunk_mutex
347	 */
348	struct list_head alloc_list;
349
350	struct list_head seed_list;
351	bool seeding;
352
353	int opened;
354
355	/* set when we find or add a device that doesn't have the
356	 * nonrot flag set
357	 */
358	bool rotating;
359	/* Devices support TRIM/discard commands */
360	bool discardable;
361
362	struct btrfs_fs_info *fs_info;
363	/* sysfs kobjects */
364	struct kobject fsid_kobj;
365	struct kobject *devices_kobj;
366	struct kobject *devinfo_kobj;
367	struct completion kobj_unregister;
368
369	enum btrfs_chunk_allocation_policy chunk_alloc_policy;
370
371	/* Policy used to read the mirrored stripes */
372	enum btrfs_read_policy read_policy;
373};
374
 
 
375#define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info)	\
376			- sizeof(struct btrfs_chunk))		\
377			/ sizeof(struct btrfs_stripe) + 1)
378
379#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE	\
380				- 2 * sizeof(struct btrfs_disk_key)	\
381				- 2 * sizeof(struct btrfs_chunk))	\
382				/ sizeof(struct btrfs_stripe) + 1)
383
384struct btrfs_io_stripe {
385	struct btrfs_device *dev;
386	union {
387		/* Block mapping */
388		u64 physical;
389		/* For the endio handler */
390		struct btrfs_io_context *bioc;
391	};
 
 
 
 
 
 
 
 
 
 
 
 
 
392};
393
394struct btrfs_discard_stripe {
 
 
 
 
 
 
 
 
 
 
 
 
 
395	struct btrfs_device *dev;
396	u64 physical;
397	u64 length;
398};
399
400/*
401 * Context for IO subsmission for device stripe.
402 *
403 * - Track the unfinished mirrors for mirror based profiles
404 *   Mirror based profiles are SINGLE/DUP/RAID1/RAID10.
405 *
406 * - Contain the logical -> physical mapping info
407 *   Used by submit_stripe_bio() for mapping logical bio
408 *   into physical device address.
409 *
410 * - Contain device replace info
411 *   Used by handle_ops_on_dev_replace() to copy logical bios
412 *   into the new device.
413 *
414 * - Contain RAID56 full stripe logical bytenrs
415 */
416struct btrfs_io_context {
417	refcount_t refs;
 
418	struct btrfs_fs_info *fs_info;
419	u64 map_type; /* get from map_lookup->type */
 
420	struct bio *orig_bio;
 
421	atomic_t error;
422	int max_errors;
423	int num_stripes;
424	int mirror_num;
425	int num_tgtdevs;
426	int *tgtdev_map;
427	/*
428	 * logical block numbers for the start of each stripe
429	 * The last one or two are p/q.  These are sorted,
430	 * so raid_map[0] is the start of our full stripe
431	 */
432	u64 *raid_map;
433	struct btrfs_io_stripe stripes[];
434};
435
436struct btrfs_device_info {
437	struct btrfs_device *dev;
438	u64 dev_offset;
439	u64 max_avail;
440	u64 total_avail;
441};
442
443struct btrfs_raid_attr {
444	u8 sub_stripes;		/* sub_stripes info for map */
445	u8 dev_stripes;		/* stripes per dev */
446	u8 devs_max;		/* max devs to use */
447	u8 devs_min;		/* min devs needed */
448	u8 tolerated_failures;	/* max tolerated fail devs */
449	u8 devs_increment;	/* ndevs has to be a multiple of this */
450	u8 ncopies;		/* how many copies to data has */
451	u8 nparity;		/* number of stripes worth of bytes to store
452				 * parity information */
453	u8 mindev_error;	/* error code if min devs requisite is unmet */
454	const char raid_name[8]; /* name of the raid */
455	u64 bg_flag;		/* block group flag of the raid */
456};
457
458extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
459
460struct map_lookup {
461	u64 type;
462	int io_align;
463	int io_width;
464	u32 stripe_len;
465	int num_stripes;
466	int sub_stripes;
467	int verified_stripes; /* For mount time dev extent verification */
468	struct btrfs_io_stripe stripes[];
469};
470
471#define map_lookup_size(n) (sizeof(struct map_lookup) + \
472			    (sizeof(struct btrfs_io_stripe) * (n)))
473
474struct btrfs_balance_args;
475struct btrfs_balance_progress;
476struct btrfs_balance_control {
477	struct btrfs_balance_args data;
478	struct btrfs_balance_args meta;
479	struct btrfs_balance_args sys;
480
481	u64 flags;
482
483	struct btrfs_balance_progress stat;
484};
485
486/*
487 * Search for a given device by the set parameters
488 */
489struct btrfs_dev_lookup_args {
490	u64 devid;
491	u8 *uuid;
492	u8 *fsid;
493	bool missing;
494};
495
496/* We have to initialize to -1 because BTRFS_DEV_REPLACE_DEVID is 0 */
497#define BTRFS_DEV_LOOKUP_ARGS_INIT { .devid = (u64)-1 }
498
499#define BTRFS_DEV_LOOKUP_ARGS(name) \
500	struct btrfs_dev_lookup_args name = BTRFS_DEV_LOOKUP_ARGS_INIT
501
502enum btrfs_map_op {
503	BTRFS_MAP_READ,
504	BTRFS_MAP_WRITE,
505	BTRFS_MAP_DISCARD,
506	BTRFS_MAP_GET_READ_MIRRORS,
507};
508
509static inline enum btrfs_map_op btrfs_op(struct bio *bio)
510{
511	switch (bio_op(bio)) {
512	case REQ_OP_DISCARD:
513		return BTRFS_MAP_DISCARD;
514	case REQ_OP_WRITE:
515	case REQ_OP_ZONE_APPEND:
516		return BTRFS_MAP_WRITE;
517	default:
518		WARN_ON_ONCE(1);
519		fallthrough;
520	case REQ_OP_READ:
521		return BTRFS_MAP_READ;
522	}
523}
524
525static inline unsigned long btrfs_chunk_item_size(int num_stripes)
526{
527	ASSERT(num_stripes);
528	return sizeof(struct btrfs_chunk) +
529		sizeof(struct btrfs_stripe) * (num_stripes - 1);
530}
531
532void btrfs_get_bioc(struct btrfs_io_context *bioc);
533void btrfs_put_bioc(struct btrfs_io_context *bioc);
534int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
535		    u64 logical, u64 *length,
536		    struct btrfs_io_context **bioc_ret, int mirror_num);
537int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
538		     u64 logical, u64 *length,
539		     struct btrfs_io_context **bioc_ret);
540int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
541		      u64 logical, u64 *length,
542		      struct btrfs_io_context **bioc_ret,
543		      struct btrfs_io_stripe *smap, int *mirror_num_ret,
544		      int need_raid_map);
545struct btrfs_discard_stripe *btrfs_map_discard(struct btrfs_fs_info *fs_info,
546					       u64 logical, u64 *length_ret,
547					       u32 *num_stripes);
548int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, struct extent_map *map,
549			  enum btrfs_map_op op, u64 logical,
550			  struct btrfs_io_geometry *io_geom);
551int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
552int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
553struct btrfs_block_group *btrfs_create_chunk(struct btrfs_trans_handle *trans,
554					    u64 type);
555void btrfs_mapping_tree_free(struct extent_map_tree *tree);
 
 
556int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
557		       fmode_t flags, void *holder);
558struct btrfs_device *btrfs_scan_one_device(const char *path,
559					   fmode_t flags, void *holder);
560int btrfs_forget_devices(dev_t devt);
561void btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
562void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices);
563void btrfs_assign_next_active_device(struct btrfs_device *device,
564				     struct btrfs_device *this_dev);
565struct btrfs_device *btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info,
566						  u64 devid,
567						  const char *devpath);
568int btrfs_get_dev_args_from_path(struct btrfs_fs_info *fs_info,
569				 struct btrfs_dev_lookup_args *args,
570				 const char *path);
571struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
572					const u64 *devid, const u8 *uuid,
573					const char *path);
574void btrfs_put_dev_args_from_path(struct btrfs_dev_lookup_args *args);
575void btrfs_free_device(struct btrfs_device *device);
576int btrfs_rm_device(struct btrfs_fs_info *fs_info,
577		    struct btrfs_dev_lookup_args *args,
578		    struct block_device **bdev, fmode_t *mode);
579void __exit btrfs_cleanup_fs_uuids(void);
580int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
581int btrfs_grow_device(struct btrfs_trans_handle *trans,
582		      struct btrfs_device *device, u64 new_size);
583struct btrfs_device *btrfs_find_device(const struct btrfs_fs_devices *fs_devices,
584				       const struct btrfs_dev_lookup_args *args);
585int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
586int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
587int btrfs_balance(struct btrfs_fs_info *fs_info,
588		  struct btrfs_balance_control *bctl,
589		  struct btrfs_ioctl_balance_args *bargs);
590void btrfs_describe_block_groups(u64 flags, char *buf, u32 size_buf);
591int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
592int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
593int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
594int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset);
595int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
596int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
597int btrfs_uuid_scan_kthread(void *data);
598bool btrfs_chunk_writeable(struct btrfs_fs_info *fs_info, u64 chunk_offset);
599int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
600			 u64 *start, u64 *max_avail);
601void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
602int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
603			struct btrfs_ioctl_get_dev_stats *stats);
604int btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
605int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
606int btrfs_run_dev_stats(struct btrfs_trans_handle *trans);
607void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev);
608void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev);
609void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev);
610int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
611			   u64 logical, u64 len);
612unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
613				    u64 logical);
614u64 btrfs_calc_stripe_length(const struct extent_map *em);
615int btrfs_nr_parity_stripes(u64 type);
616int btrfs_chunk_alloc_add_chunk_item(struct btrfs_trans_handle *trans,
617				     struct btrfs_block_group *bg);
618int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
619struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
620				       u64 logical, u64 length);
621void btrfs_release_disk_super(struct btrfs_super_block *super);
622
623static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
624				      int index)
625{
626	atomic_inc(dev->dev_stat_values + index);
627	/*
628	 * This memory barrier orders stores updating statistics before stores
629	 * updating dev_stats_ccnt.
630	 *
631	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
632	 */
633	smp_mb__before_atomic();
634	atomic_inc(&dev->dev_stats_ccnt);
635}
636
637static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
638				      int index)
639{
640	return atomic_read(dev->dev_stat_values + index);
641}
642
643static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
644						int index)
645{
646	int ret;
647
648	ret = atomic_xchg(dev->dev_stat_values + index, 0);
649	/*
650	 * atomic_xchg implies a full memory barriers as per atomic_t.txt:
651	 * - RMW operations that have a return value are fully ordered;
652	 *
653	 * This implicit memory barriers is paired with the smp_rmb in
654	 * btrfs_run_dev_stats
655	 */
656	atomic_inc(&dev->dev_stats_ccnt);
657	return ret;
658}
659
660static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
661				      int index, unsigned long val)
662{
663	atomic_set(dev->dev_stat_values + index, val);
664	/*
665	 * This memory barrier orders stores updating statistics before stores
666	 * updating dev_stats_ccnt.
667	 *
668	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
669	 */
670	smp_mb__before_atomic();
671	atomic_inc(&dev->dev_stats_ccnt);
672}
673
674static inline const char *btrfs_dev_name(const struct btrfs_device *device)
 
 
 
 
675{
676	if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
677		return "<missing disk>";
678	else
679		return rcu_str_deref(device->name);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
680}
681
682void btrfs_commit_device_sizes(struct btrfs_transaction *trans);
683
684struct list_head * __attribute_const__ btrfs_get_fs_uuids(void);
685bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
686					struct btrfs_device *failing_dev);
687void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
688			       struct block_device *bdev,
689			       const char *device_path);
690
691enum btrfs_raid_types __attribute_const__ btrfs_bg_flags_to_raid_index(u64 flags);
692int btrfs_bg_type_to_factor(u64 flags);
693const char *btrfs_bg_type_to_raid_name(u64 flags);
694int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
695bool btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical);
696
697bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);
698
699#endif
v5.14.15
  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
 16extern struct mutex uuid_mutex;
 17
 18#define BTRFS_STRIPE_LEN	SZ_64K
 19
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 20struct btrfs_io_geometry {
 21	/* remaining bytes before crossing a stripe */
 22	u64 len;
 23	/* offset of logical address in chunk */
 24	u64 offset;
 25	/* length of single IO stripe */
 26	u64 stripe_len;
 
 
 27	/* number of stripe where address falls */
 28	u64 stripe_nr;
 29	/* offset of address in stripe */
 30	u64 stripe_offset;
 31	/* offset of raid56 stripe into the chunk */
 32	u64 raid56_stripe_offset;
 33};
 34
 35/*
 36 * Use sequence counter to get consistent device stat data on
 37 * 32-bit processors.
 38 */
 39#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
 40#include <linux/seqlock.h>
 41#define __BTRFS_NEED_DEVICE_DATA_ORDERED
 42#define btrfs_device_data_ordered_init(device)	\
 43	seqcount_init(&device->data_seqcount)
 44#else
 45#define btrfs_device_data_ordered_init(device) do { } while (0)
 46#endif
 47
 48#define BTRFS_DEV_STATE_WRITEABLE	(0)
 49#define BTRFS_DEV_STATE_IN_FS_METADATA	(1)
 50#define BTRFS_DEV_STATE_MISSING		(2)
 51#define BTRFS_DEV_STATE_REPLACE_TGT	(3)
 52#define BTRFS_DEV_STATE_FLUSH_SENT	(4)
 53#define BTRFS_DEV_STATE_NO_READA	(5)
 54
 55struct btrfs_zoned_device_info;
 56
 57struct btrfs_device {
 58	struct list_head dev_list; /* device_list_mutex */
 59	struct list_head dev_alloc_list; /* chunk mutex */
 60	struct list_head post_commit_list; /* chunk mutex */
 61	struct btrfs_fs_devices *fs_devices;
 62	struct btrfs_fs_info *fs_info;
 63
 64	struct rcu_string __rcu *name;
 65
 66	u64 generation;
 67
 68	struct block_device *bdev;
 69
 70	struct btrfs_zoned_device_info *zone_info;
 71
 72	/* the mode sent to blkdev_get */
 73	fmode_t mode;
 74
 
 
 
 
 
 75	unsigned long dev_state;
 76	blk_status_t last_flush_error;
 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 chunk mutex
113	 */
114	u64 commit_total_bytes;
115
116	/* bytes used on the current transaction */
117	u64 commit_bytes_used;
118
119	/* for sending down flush barriers */
120	struct bio *flush_bio;
121	struct completion flush_wait;
122
123	/* per-device scrub information */
124	struct scrub_ctx *scrub_ctx;
125
126	/* readahead state */
127	atomic_t reada_in_flight;
128	u64 reada_next;
129	struct reada_zone *reada_curr_zone;
130	struct radix_tree_root reada_zones;
131	struct radix_tree_root reada_extents;
132
133	/* disk I/O failure stats. For detailed description refer to
134	 * enum btrfs_dev_stat_values in ioctl.h */
135	int dev_stats_valid;
136
137	/* Counter to record the change of device stats */
138	atomic_t dev_stats_ccnt;
139	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
140
141	struct extent_io_tree alloc_state;
142
143	struct completion kobj_unregister;
144	/* For sysfs/FSID/devinfo/devid/ */
145	struct kobject devid_kobj;
146
147	/* Bandwidth limit for scrub, in bytes */
148	u64 scrub_speed_max;
149};
150
151/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
152 * If we read those variants at the context of their own lock, we needn't
153 * use the following helpers, reading them directly is safe.
154 */
155#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
156#define BTRFS_DEVICE_GETSET_FUNCS(name)					\
157static inline u64							\
158btrfs_device_get_##name(const struct btrfs_device *dev)			\
159{									\
160	u64 size;							\
161	unsigned int seq;						\
162									\
163	do {								\
164		seq = read_seqcount_begin(&dev->data_seqcount);		\
165		size = dev->name;					\
166	} while (read_seqcount_retry(&dev->data_seqcount, seq));	\
167	return size;							\
168}									\
169									\
170static inline void							\
171btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
172{									\
173	preempt_disable();						\
174	write_seqcount_begin(&dev->data_seqcount);			\
175	dev->name = size;						\
176	write_seqcount_end(&dev->data_seqcount);			\
177	preempt_enable();						\
178}
179#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
180#define BTRFS_DEVICE_GETSET_FUNCS(name)					\
181static inline u64							\
182btrfs_device_get_##name(const struct btrfs_device *dev)			\
183{									\
184	u64 size;							\
185									\
186	preempt_disable();						\
187	size = dev->name;						\
188	preempt_enable();						\
189	return size;							\
190}									\
191									\
192static inline void							\
193btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
194{									\
195	preempt_disable();						\
196	dev->name = size;						\
197	preempt_enable();						\
198}
199#else
200#define BTRFS_DEVICE_GETSET_FUNCS(name)					\
201static inline u64							\
202btrfs_device_get_##name(const struct btrfs_device *dev)			\
203{									\
204	return dev->name;						\
205}									\
206									\
207static inline void							\
208btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
209{									\
210	dev->name = size;						\
211}
212#endif
213
214BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
215BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
216BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
217
218enum btrfs_chunk_allocation_policy {
219	BTRFS_CHUNK_ALLOC_REGULAR,
220	BTRFS_CHUNK_ALLOC_ZONED,
221};
222
223/*
224 * Read policies for mirrored block group profiles, read picks the stripe based
225 * on these policies.
226 */
227enum btrfs_read_policy {
228	/* Use process PID to choose the stripe */
229	BTRFS_READ_POLICY_PID,
230	BTRFS_NR_READ_POLICY,
231};
232
233struct btrfs_fs_devices {
234	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
235	u8 metadata_uuid[BTRFS_FSID_SIZE];
236	bool fsid_change;
237	struct list_head fs_list;
238
 
 
 
 
239	u64 num_devices;
 
 
 
 
 
240	u64 open_devices;
 
 
241	u64 rw_devices;
 
 
242	u64 missing_devices;
243	u64 total_rw_bytes;
 
 
 
 
 
 
244	u64 total_devices;
245
246	/* Highest generation number of seen devices */
247	u64 latest_generation;
248
249	struct block_device *latest_bdev;
 
 
 
 
250
251	/* all of the devices in the FS, protected by a mutex
252	 * so we can safely walk it to write out the supers without
253	 * worrying about add/remove by the multi-device code.
254	 * Scrubbing super can kick off supers writing by holding
255	 * this mutex lock.
256	 */
257	struct mutex device_list_mutex;
258
259	/* List of all devices, protected by device_list_mutex */
260	struct list_head devices;
261
262	/*
263	 * Devices which can satisfy space allocation. Protected by
264	 * chunk_mutex
265	 */
266	struct list_head alloc_list;
267
268	struct list_head seed_list;
269	bool seeding;
270
271	int opened;
272
273	/* set when we find or add a device that doesn't have the
274	 * nonrot flag set
275	 */
276	bool rotating;
 
 
277
278	struct btrfs_fs_info *fs_info;
279	/* sysfs kobjects */
280	struct kobject fsid_kobj;
281	struct kobject *devices_kobj;
282	struct kobject *devinfo_kobj;
283	struct completion kobj_unregister;
284
285	enum btrfs_chunk_allocation_policy chunk_alloc_policy;
286
287	/* Policy used to read the mirrored stripes */
288	enum btrfs_read_policy read_policy;
289};
290
291#define BTRFS_BIO_INLINE_CSUM_SIZE	64
292
293#define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info)	\
294			- sizeof(struct btrfs_chunk))		\
295			/ sizeof(struct btrfs_stripe) + 1)
296
297#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE	\
298				- 2 * sizeof(struct btrfs_disk_key)	\
299				- 2 * sizeof(struct btrfs_chunk))	\
300				/ sizeof(struct btrfs_stripe) + 1)
301
302/*
303 * we need the mirror number and stripe index to be passed around
304 * the call chain while we are processing end_io (especially errors).
305 * Really, what we need is a btrfs_bio structure that has this info
306 * and is properly sized with its stripe array, but we're not there
307 * quite yet.  We have our own btrfs bioset, and all of the bios
308 * we allocate are actually btrfs_io_bios.  We'll cram as much of
309 * struct btrfs_bio as we can into this over time.
310 */
311struct btrfs_io_bio {
312	unsigned int mirror_num;
313	struct btrfs_device *device;
314	u64 logical;
315	u8 *csum;
316	u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
317	struct bvec_iter iter;
318	/*
319	 * This member must come last, bio_alloc_bioset will allocate enough
320	 * bytes for entire btrfs_io_bio but relies on bio being last.
321	 */
322	struct bio bio;
323};
324
325static inline struct btrfs_io_bio *btrfs_io_bio(struct bio *bio)
326{
327	return container_of(bio, struct btrfs_io_bio, bio);
328}
329
330static inline void btrfs_io_bio_free_csum(struct btrfs_io_bio *io_bio)
331{
332	if (io_bio->csum != io_bio->csum_inline) {
333		kfree(io_bio->csum);
334		io_bio->csum = NULL;
335	}
336}
337
338struct btrfs_bio_stripe {
339	struct btrfs_device *dev;
340	u64 physical;
341	u64 length; /* only used for discard mappings */
342};
343
344struct btrfs_bio {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
345	refcount_t refs;
346	atomic_t stripes_pending;
347	struct btrfs_fs_info *fs_info;
348	u64 map_type; /* get from map_lookup->type */
349	bio_end_io_t *end_io;
350	struct bio *orig_bio;
351	void *private;
352	atomic_t error;
353	int max_errors;
354	int num_stripes;
355	int mirror_num;
356	int num_tgtdevs;
357	int *tgtdev_map;
358	/*
359	 * logical block numbers for the start of each stripe
360	 * The last one or two are p/q.  These are sorted,
361	 * so raid_map[0] is the start of our full stripe
362	 */
363	u64 *raid_map;
364	struct btrfs_bio_stripe stripes[];
365};
366
367struct btrfs_device_info {
368	struct btrfs_device *dev;
369	u64 dev_offset;
370	u64 max_avail;
371	u64 total_avail;
372};
373
374struct btrfs_raid_attr {
375	u8 sub_stripes;		/* sub_stripes info for map */
376	u8 dev_stripes;		/* stripes per dev */
377	u8 devs_max;		/* max devs to use */
378	u8 devs_min;		/* min devs needed */
379	u8 tolerated_failures;	/* max tolerated fail devs */
380	u8 devs_increment;	/* ndevs has to be a multiple of this */
381	u8 ncopies;		/* how many copies to data has */
382	u8 nparity;		/* number of stripes worth of bytes to store
383				 * parity information */
384	u8 mindev_error;	/* error code if min devs requisite is unmet */
385	const char raid_name[8]; /* name of the raid */
386	u64 bg_flag;		/* block group flag of the raid */
387};
388
389extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
390
391struct map_lookup {
392	u64 type;
393	int io_align;
394	int io_width;
395	u64 stripe_len;
396	int num_stripes;
397	int sub_stripes;
398	int verified_stripes; /* For mount time dev extent verification */
399	struct btrfs_bio_stripe stripes[];
400};
401
402#define map_lookup_size(n) (sizeof(struct map_lookup) + \
403			    (sizeof(struct btrfs_bio_stripe) * (n)))
404
405struct btrfs_balance_args;
406struct btrfs_balance_progress;
407struct btrfs_balance_control {
408	struct btrfs_balance_args data;
409	struct btrfs_balance_args meta;
410	struct btrfs_balance_args sys;
411
412	u64 flags;
413
414	struct btrfs_balance_progress stat;
415};
416
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
417enum btrfs_map_op {
418	BTRFS_MAP_READ,
419	BTRFS_MAP_WRITE,
420	BTRFS_MAP_DISCARD,
421	BTRFS_MAP_GET_READ_MIRRORS,
422};
423
424static inline enum btrfs_map_op btrfs_op(struct bio *bio)
425{
426	switch (bio_op(bio)) {
427	case REQ_OP_DISCARD:
428		return BTRFS_MAP_DISCARD;
429	case REQ_OP_WRITE:
430	case REQ_OP_ZONE_APPEND:
431		return BTRFS_MAP_WRITE;
432	default:
433		WARN_ON_ONCE(1);
434		fallthrough;
435	case REQ_OP_READ:
436		return BTRFS_MAP_READ;
437	}
438}
439
440void btrfs_get_bbio(struct btrfs_bio *bbio);
441void btrfs_put_bbio(struct btrfs_bio *bbio);
 
 
 
 
 
 
 
442int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
443		    u64 logical, u64 *length,
444		    struct btrfs_bio **bbio_ret, int mirror_num);
445int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
446		     u64 logical, u64 *length,
447		     struct btrfs_bio **bbio_ret);
 
 
 
 
 
 
 
 
448int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, struct extent_map *map,
449			  enum btrfs_map_op op, u64 logical,
450			  struct btrfs_io_geometry *io_geom);
451int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
452int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
453struct btrfs_block_group *btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
454					    u64 type);
455void btrfs_mapping_tree_free(struct extent_map_tree *tree);
456blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
457			   int mirror_num);
458int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
459		       fmode_t flags, void *holder);
460struct btrfs_device *btrfs_scan_one_device(const char *path,
461					   fmode_t flags, void *holder);
462int btrfs_forget_devices(const char *path);
463void btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
464void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices);
465void btrfs_assign_next_active_device(struct btrfs_device *device,
466				     struct btrfs_device *this_dev);
467struct btrfs_device *btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info,
468						  u64 devid,
469						  const char *devpath);
 
 
 
470struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
471					const u64 *devid,
472					const u8 *uuid);
 
473void btrfs_free_device(struct btrfs_device *device);
474int btrfs_rm_device(struct btrfs_fs_info *fs_info,
475		    const char *device_path, u64 devid,
476		    struct block_device **bdev, fmode_t *mode);
477void __exit btrfs_cleanup_fs_uuids(void);
478int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
479int btrfs_grow_device(struct btrfs_trans_handle *trans,
480		      struct btrfs_device *device, u64 new_size);
481struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices,
482				       u64 devid, u8 *uuid, u8 *fsid);
483int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
484int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
485int btrfs_balance(struct btrfs_fs_info *fs_info,
486		  struct btrfs_balance_control *bctl,
487		  struct btrfs_ioctl_balance_args *bargs);
488void btrfs_describe_block_groups(u64 flags, char *buf, u32 size_buf);
489int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
490int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
491int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
492int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset);
493int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
494int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
495int btrfs_uuid_scan_kthread(void *data);
496int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset);
497int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
498			 u64 *start, u64 *max_avail);
499void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
500int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
501			struct btrfs_ioctl_get_dev_stats *stats);
502void btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
503int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
504int btrfs_run_dev_stats(struct btrfs_trans_handle *trans);
505void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev);
506void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev);
507void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev);
508int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
509			   u64 logical, u64 len);
510unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
511				    u64 logical);
512int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
513			     u64 chunk_offset, u64 chunk_size);
514int btrfs_chunk_alloc_add_chunk_item(struct btrfs_trans_handle *trans,
515				     struct btrfs_block_group *bg);
516int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
517struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
518				       u64 logical, u64 length);
519void btrfs_release_disk_super(struct btrfs_super_block *super);
520
521static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
522				      int index)
523{
524	atomic_inc(dev->dev_stat_values + index);
525	/*
526	 * This memory barrier orders stores updating statistics before stores
527	 * updating dev_stats_ccnt.
528	 *
529	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
530	 */
531	smp_mb__before_atomic();
532	atomic_inc(&dev->dev_stats_ccnt);
533}
534
535static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
536				      int index)
537{
538	return atomic_read(dev->dev_stat_values + index);
539}
540
541static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
542						int index)
543{
544	int ret;
545
546	ret = atomic_xchg(dev->dev_stat_values + index, 0);
547	/*
548	 * atomic_xchg implies a full memory barriers as per atomic_t.txt:
549	 * - RMW operations that have a return value are fully ordered;
550	 *
551	 * This implicit memory barriers is paired with the smp_rmb in
552	 * btrfs_run_dev_stats
553	 */
554	atomic_inc(&dev->dev_stats_ccnt);
555	return ret;
556}
557
558static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
559				      int index, unsigned long val)
560{
561	atomic_set(dev->dev_stat_values + index, val);
562	/*
563	 * This memory barrier orders stores updating statistics before stores
564	 * updating dev_stats_ccnt.
565	 *
566	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
567	 */
568	smp_mb__before_atomic();
569	atomic_inc(&dev->dev_stats_ccnt);
570}
571
572/*
573 * Convert block group flags (BTRFS_BLOCK_GROUP_*) to btrfs_raid_types, which
574 * can be used as index to access btrfs_raid_array[].
575 */
576static inline enum btrfs_raid_types btrfs_bg_flags_to_raid_index(u64 flags)
577{
578	if (flags & BTRFS_BLOCK_GROUP_RAID10)
579		return BTRFS_RAID_RAID10;
580	else if (flags & BTRFS_BLOCK_GROUP_RAID1)
581		return BTRFS_RAID_RAID1;
582	else if (flags & BTRFS_BLOCK_GROUP_RAID1C3)
583		return BTRFS_RAID_RAID1C3;
584	else if (flags & BTRFS_BLOCK_GROUP_RAID1C4)
585		return BTRFS_RAID_RAID1C4;
586	else if (flags & BTRFS_BLOCK_GROUP_DUP)
587		return BTRFS_RAID_DUP;
588	else if (flags & BTRFS_BLOCK_GROUP_RAID0)
589		return BTRFS_RAID_RAID0;
590	else if (flags & BTRFS_BLOCK_GROUP_RAID5)
591		return BTRFS_RAID_RAID5;
592	else if (flags & BTRFS_BLOCK_GROUP_RAID6)
593		return BTRFS_RAID_RAID6;
594
595	return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
596}
597
598void btrfs_commit_device_sizes(struct btrfs_transaction *trans);
599
600struct list_head * __attribute_const__ btrfs_get_fs_uuids(void);
601bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
602					struct btrfs_device *failing_dev);
603void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
604			       struct block_device *bdev,
605			       const char *device_path);
606
 
607int btrfs_bg_type_to_factor(u64 flags);
608const char *btrfs_bg_type_to_raid_name(u64 flags);
609int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
610int btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical);
 
 
611
612#endif