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v6.8
  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#define BTRFS_STRIPE_LEN_SHIFT		(16)
 22#define BTRFS_STRIPE_LEN_MASK		(BTRFS_STRIPE_LEN - 1)
 23
 24static_assert(const_ilog2(BTRFS_STRIPE_LEN) == BTRFS_STRIPE_LEN_SHIFT);
 25
 26/* Used by sanity check for btrfs_raid_types. */
 27#define const_ffs(n) (__builtin_ctzll(n) + 1)
 28
 29/*
 30 * The conversion from BTRFS_BLOCK_GROUP_* bits to btrfs_raid_type requires
 31 * RAID0 always to be the lowest profile bit.
 32 * Although it's part of on-disk format and should never change, do extra
 33 * compile-time sanity checks.
 34 */
 35static_assert(const_ffs(BTRFS_BLOCK_GROUP_RAID0) <
 36	      const_ffs(BTRFS_BLOCK_GROUP_PROFILE_MASK & ~BTRFS_BLOCK_GROUP_RAID0));
 37static_assert(const_ilog2(BTRFS_BLOCK_GROUP_RAID0) >
 38	      ilog2(BTRFS_BLOCK_GROUP_TYPE_MASK));
 39
 40/* ilog2() can handle both constants and variables */
 41#define BTRFS_BG_FLAG_TO_INDEX(profile)					\
 42	ilog2((profile) >> (ilog2(BTRFS_BLOCK_GROUP_RAID0) - 1))
 43
 44enum btrfs_raid_types {
 45	/* SINGLE is the special one as it doesn't have on-disk bit. */
 46	BTRFS_RAID_SINGLE  = 0,
 47
 48	BTRFS_RAID_RAID0   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID0),
 49	BTRFS_RAID_RAID1   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1),
 50	BTRFS_RAID_DUP	   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_DUP),
 51	BTRFS_RAID_RAID10  = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID10),
 52	BTRFS_RAID_RAID5   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID5),
 53	BTRFS_RAID_RAID6   = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID6),
 54	BTRFS_RAID_RAID1C3 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1C3),
 55	BTRFS_RAID_RAID1C4 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1C4),
 56
 57	BTRFS_NR_RAID_TYPES
 58};
 59
 60/*
 61 * Use sequence counter to get consistent device stat data on
 62 * 32-bit processors.
 63 */
 64#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
 65#include <linux/seqlock.h>
 66#define __BTRFS_NEED_DEVICE_DATA_ORDERED
 67#define btrfs_device_data_ordered_init(device)	\
 68	seqcount_init(&device->data_seqcount)
 69#else
 70#define btrfs_device_data_ordered_init(device) do { } while (0)
 71#endif
 72
 73#define BTRFS_DEV_STATE_WRITEABLE	(0)
 74#define BTRFS_DEV_STATE_IN_FS_METADATA	(1)
 75#define BTRFS_DEV_STATE_MISSING		(2)
 76#define BTRFS_DEV_STATE_REPLACE_TGT	(3)
 77#define BTRFS_DEV_STATE_FLUSH_SENT	(4)
 78#define BTRFS_DEV_STATE_NO_READA	(5)
 79
 80struct btrfs_zoned_device_info;
 81
 82struct btrfs_device {
 83	struct list_head dev_list; /* device_list_mutex */
 84	struct list_head dev_alloc_list; /* chunk mutex */
 85	struct list_head post_commit_list; /* chunk mutex */
 86	struct btrfs_fs_devices *fs_devices;
 87	struct btrfs_fs_info *fs_info;
 88
 89	struct rcu_string __rcu *name;
 90
 91	u64 generation;
 92
 93	struct bdev_handle *bdev_handle;
 94	struct block_device *bdev;
 95
 96	struct btrfs_zoned_device_info *zone_info;
 
 97
 98	/*
 99	 * Device's major-minor number. Must be set even if the device is not
100	 * opened (bdev == NULL), unless the device is missing.
101	 */
102	dev_t devt;
103	unsigned long dev_state;
104	blk_status_t last_flush_error;
105
106#ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
107	seqcount_t data_seqcount;
108#endif
109
110	/* the internal btrfs device id */
111	u64 devid;
112
113	/* size of the device in memory */
114	u64 total_bytes;
115
116	/* size of the device on disk */
117	u64 disk_total_bytes;
118
119	/* bytes used */
120	u64 bytes_used;
121
122	/* optimal io alignment for this device */
123	u32 io_align;
124
125	/* optimal io width for this device */
126	u32 io_width;
127	/* type and info about this device */
128	u64 type;
129
130	/* minimal io size for this device */
131	u32 sector_size;
132
133	/* physical drive uuid (or lvm uuid) */
134	u8 uuid[BTRFS_UUID_SIZE];
135
136	/*
137	 * size of the device on the current transaction
138	 *
139	 * This variant is update when committing the transaction,
140	 * and protected by chunk mutex
141	 */
142	u64 commit_total_bytes;
143
144	/* bytes used on the current transaction */
145	u64 commit_bytes_used;
146
147	/* Bio used for flushing device barriers */
148	struct bio flush_bio;
149	struct completion flush_wait;
150
151	/* per-device scrub information */
152	struct scrub_ctx *scrub_ctx;
153
 
 
 
 
 
 
 
154	/* disk I/O failure stats. For detailed description refer to
155	 * enum btrfs_dev_stat_values in ioctl.h */
156	int dev_stats_valid;
157
158	/* Counter to record the change of device stats */
159	atomic_t dev_stats_ccnt;
160	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
161
162	struct extent_io_tree alloc_state;
163
164	struct completion kobj_unregister;
165	/* For sysfs/FSID/devinfo/devid/ */
166	struct kobject devid_kobj;
167
168	/* Bandwidth limit for scrub, in bytes */
169	u64 scrub_speed_max;
170};
171
172/*
173 * Block group or device which contains an active swapfile. Used for preventing
174 * unsafe operations while a swapfile is active.
175 *
176 * These are sorted on (ptr, inode) (note that a block group or device can
177 * contain more than one swapfile). We compare the pointer values because we
178 * don't actually care what the object is, we just need a quick check whether
179 * the object exists in the rbtree.
180 */
181struct btrfs_swapfile_pin {
182	struct rb_node node;
183	void *ptr;
184	struct inode *inode;
185	/*
186	 * If true, ptr points to a struct btrfs_block_group. Otherwise, ptr
187	 * points to a struct btrfs_device.
188	 */
189	bool is_block_group;
190	/*
191	 * Only used when 'is_block_group' is true and it is the number of
192	 * extents used by a swapfile for this block group ('ptr' field).
193	 */
194	int bg_extent_count;
195};
196
197/*
198 * If we read those variants at the context of their own lock, we needn't
199 * use the following helpers, reading them directly is safe.
200 */
201#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
202#define BTRFS_DEVICE_GETSET_FUNCS(name)					\
203static inline u64							\
204btrfs_device_get_##name(const struct btrfs_device *dev)			\
205{									\
206	u64 size;							\
207	unsigned int seq;						\
208									\
209	do {								\
210		seq = read_seqcount_begin(&dev->data_seqcount);		\
211		size = dev->name;					\
212	} while (read_seqcount_retry(&dev->data_seqcount, seq));	\
213	return size;							\
214}									\
215									\
216static inline void							\
217btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
218{									\
219	preempt_disable();						\
220	write_seqcount_begin(&dev->data_seqcount);			\
221	dev->name = size;						\
222	write_seqcount_end(&dev->data_seqcount);			\
223	preempt_enable();						\
224}
225#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
226#define BTRFS_DEVICE_GETSET_FUNCS(name)					\
227static inline u64							\
228btrfs_device_get_##name(const struct btrfs_device *dev)			\
229{									\
230	u64 size;							\
231									\
232	preempt_disable();						\
233	size = dev->name;						\
234	preempt_enable();						\
235	return size;							\
236}									\
237									\
238static inline void							\
239btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
240{									\
241	preempt_disable();						\
242	dev->name = size;						\
243	preempt_enable();						\
244}
245#else
246#define BTRFS_DEVICE_GETSET_FUNCS(name)					\
247static inline u64							\
248btrfs_device_get_##name(const struct btrfs_device *dev)			\
249{									\
250	return dev->name;						\
251}									\
252									\
253static inline void							\
254btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
255{									\
256	dev->name = size;						\
257}
258#endif
259
260BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
261BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
262BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
263
264enum btrfs_chunk_allocation_policy {
265	BTRFS_CHUNK_ALLOC_REGULAR,
266	BTRFS_CHUNK_ALLOC_ZONED,
267};
268
269/*
270 * Read policies for mirrored block group profiles, read picks the stripe based
271 * on these policies.
272 */
273enum btrfs_read_policy {
274	/* Use process PID to choose the stripe */
275	BTRFS_READ_POLICY_PID,
276	BTRFS_NR_READ_POLICY,
277};
278
279struct btrfs_fs_devices {
280	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
281
282	/*
283	 * UUID written into the btree blocks:
284	 *
285	 * - If metadata_uuid != fsid then super block must have
286	 *   BTRFS_FEATURE_INCOMPAT_METADATA_UUID flag set.
287	 *
288	 * - Following shall be true at all times:
289	 *   - metadata_uuid == btrfs_header::fsid
290	 *   - metadata_uuid == btrfs_dev_item::fsid
291	 *
292	 * - Relations between fsid and metadata_uuid in sb and fs_devices:
293	 *   - Normal:
294	 *       fs_devices->fsid == fs_devices->metadata_uuid == sb->fsid
295	 *       sb->metadata_uuid == 0
296	 *
297	 *   - When the BTRFS_FEATURE_INCOMPAT_METADATA_UUID flag is set:
298	 *       fs_devices->fsid == sb->fsid
299	 *       fs_devices->metadata_uuid == sb->metadata_uuid
300	 *
301	 *   - When in-memory fs_devices->temp_fsid is true
302	 *	 fs_devices->fsid = random
303	 *	 fs_devices->metadata_uuid == sb->fsid
304	 */
305	u8 metadata_uuid[BTRFS_FSID_SIZE];
306
307	struct list_head fs_list;
308
309	/*
310	 * Number of devices under this fsid including missing and
311	 * replace-target device and excludes seed devices.
312	 */
313	u64 num_devices;
314
315	/*
316	 * The number of devices that successfully opened, including
317	 * replace-target, excludes seed devices.
318	 */
319	u64 open_devices;
320
321	/* The number of devices that are under the chunk allocation list. */
322	u64 rw_devices;
323
324	/* Count of missing devices under this fsid excluding seed device. */
325	u64 missing_devices;
326	u64 total_rw_bytes;
327
328	/*
329	 * Count of devices from btrfs_super_block::num_devices for this fsid,
330	 * which includes the seed device, excludes the transient replace-target
331	 * device.
332	 */
333	u64 total_devices;
334
335	/* Highest generation number of seen devices */
336	u64 latest_generation;
337
338	/*
339	 * The mount device or a device with highest generation after removal
340	 * or replace.
341	 */
342	struct btrfs_device *latest_dev;
343
344	/*
345	 * All of the devices in the filesystem, protected by a mutex so we can
346	 * safely walk it to write out the super blocks without worrying about
347	 * adding/removing by the multi-device code. Scrubbing super block can
348	 * kick off supers writing by holding this mutex lock.
349	 */
350	struct mutex device_list_mutex;
351
352	/* List of all devices, protected by device_list_mutex */
353	struct list_head devices;
354
355	/* Devices which can satisfy space allocation. Protected by * chunk_mutex. */
 
 
 
356	struct list_head alloc_list;
357
358	struct list_head seed_list;
 
359
360	/* Count fs-devices opened. */
361	int opened;
362
363	/* Set when we find or add a device that doesn't have the nonrot flag set. */
 
 
364	bool rotating;
365	/* Devices support TRIM/discard commands. */
366	bool discardable;
367	/* The filesystem is a seed filesystem. */
368	bool seeding;
369	/* The mount needs to use a randomly generated fsid. */
370	bool temp_fsid;
371
372	struct btrfs_fs_info *fs_info;
373	/* sysfs kobjects */
374	struct kobject fsid_kobj;
375	struct kobject *devices_kobj;
376	struct kobject *devinfo_kobj;
377	struct completion kobj_unregister;
378
379	enum btrfs_chunk_allocation_policy chunk_alloc_policy;
380
381	/* Policy used to read the mirrored stripes. */
382	enum btrfs_read_policy read_policy;
383};
384
 
 
385#define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info)	\
386			- sizeof(struct btrfs_chunk))		\
387			/ sizeof(struct btrfs_stripe) + 1)
388
389#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE	\
390				- 2 * sizeof(struct btrfs_disk_key)	\
391				- 2 * sizeof(struct btrfs_chunk))	\
392				/ sizeof(struct btrfs_stripe) + 1)
393
394struct btrfs_io_stripe {
395	struct btrfs_device *dev;
396	/* Block mapping. */
397	u64 physical;
398	u64 length;
399	bool is_scrub;
400	/* For the endio handler. */
401	struct btrfs_io_context *bioc;
 
 
 
 
 
 
 
 
 
 
 
 
 
402};
403
404struct btrfs_discard_stripe {
 
 
 
 
 
 
 
 
 
 
 
 
 
405	struct btrfs_device *dev;
406	u64 physical;
407	u64 length;
408};
409
410/*
411 * Context for IO subsmission for device stripe.
412 *
413 * - Track the unfinished mirrors for mirror based profiles
414 *   Mirror based profiles are SINGLE/DUP/RAID1/RAID10.
415 *
416 * - Contain the logical -> physical mapping info
417 *   Used by submit_stripe_bio() for mapping logical bio
418 *   into physical device address.
419 *
420 * - Contain device replace info
421 *   Used by handle_ops_on_dev_replace() to copy logical bios
422 *   into the new device.
423 *
424 * - Contain RAID56 full stripe logical bytenrs
425 */
426struct btrfs_io_context {
427	refcount_t refs;
 
428	struct btrfs_fs_info *fs_info;
429	/* Taken from struct btrfs_chunk_map::type. */
430	u64 map_type;
431	struct bio *orig_bio;
 
432	atomic_t error;
433	u16 max_errors;
434
435	u64 logical;
436	u64 size;
437	/* Raid stripe tree ordered entry. */
438	struct list_head rst_ordered_entry;
439
440	/*
441	 * The total number of stripes, including the extra duplicated
442	 * stripe for replace.
443	 */
444	u16 num_stripes;
445
446	/*
447	 * The mirror_num of this bioc.
448	 *
449	 * This is for reads which use 0 as mirror_num, thus we should return a
450	 * valid mirror_num (>0) for the reader.
451	 */
452	u16 mirror_num;
453
454	/*
455	 * The following two members are for dev-replace case only.
456	 *
457	 * @replace_nr_stripes:	Number of duplicated stripes which need to be
458	 *			written to replace target.
459	 *			Should be <= 2 (2 for DUP, otherwise <= 1).
460	 * @replace_stripe_src:	The array indicates where the duplicated stripes
461	 *			are from.
462	 *
463	 * The @replace_stripe_src[] array is mostly for RAID56 cases.
464	 * As non-RAID56 stripes share the same contents of the mapped range,
465	 * thus no need to bother where the duplicated ones are from.
466	 *
467	 * But for RAID56 case, all stripes contain different contents, thus
468	 * we need a way to know the mapping.
469	 *
470	 * There is an example for the two members, using a RAID5 write:
471	 *
472	 *   num_stripes:	4 (3 + 1 duplicated write)
473	 *   stripes[0]:	dev = devid 1, physical = X
474	 *   stripes[1]:	dev = devid 2, physical = Y
475	 *   stripes[2]:	dev = devid 3, physical = Z
476	 *   stripes[3]:	dev = devid 0, physical = Y
477	 *
478	 * replace_nr_stripes = 1
479	 * replace_stripe_src = 1	<- Means stripes[1] is involved in replace.
480	 *				   The duplicated stripe index would be
481	 *				   (@num_stripes - 1).
482	 *
483	 * Note, that we can still have cases replace_nr_stripes = 2 for DUP.
484	 * In that case, all stripes share the same content, thus we don't
485	 * need to bother @replace_stripe_src value at all.
486	 */
487	u16 replace_nr_stripes;
488	s16 replace_stripe_src;
489	/*
490	 * Logical bytenr of the full stripe start, only for RAID56 cases.
491	 *
492	 * When this value is set to other than (u64)-1, the stripes[] should
493	 * follow this pattern:
494	 *
495	 * (real_stripes = num_stripes - replace_nr_stripes)
496	 * (data_stripes = (is_raid6) ? (real_stripes - 2) : (real_stripes - 1))
497	 *
498	 * stripes[0]:			The first data stripe
499	 * stripes[1]:			The second data stripe
500	 * ...
501	 * stripes[data_stripes - 1]:	The last data stripe
502	 * stripes[data_stripes]:	The P stripe
503	 * stripes[data_stripes + 1]:	The Q stripe (only for RAID6).
504	 */
505	u64 full_stripe_logical;
506	struct btrfs_io_stripe stripes[];
507};
508
509struct btrfs_device_info {
510	struct btrfs_device *dev;
511	u64 dev_offset;
512	u64 max_avail;
513	u64 total_avail;
514};
515
516struct btrfs_raid_attr {
517	u8 sub_stripes;		/* sub_stripes info for map */
518	u8 dev_stripes;		/* stripes per dev */
519	u8 devs_max;		/* max devs to use */
520	u8 devs_min;		/* min devs needed */
521	u8 tolerated_failures;	/* max tolerated fail devs */
522	u8 devs_increment;	/* ndevs has to be a multiple of this */
523	u8 ncopies;		/* how many copies to data has */
524	u8 nparity;		/* number of stripes worth of bytes to store
525				 * parity information */
526	u8 mindev_error;	/* error code if min devs requisite is unmet */
527	const char raid_name[8]; /* name of the raid */
528	u64 bg_flag;		/* block group flag of the raid */
529};
530
531extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
532
533struct btrfs_chunk_map {
534	struct rb_node rb_node;
535	/* For mount time dev extent verification. */
536	int verified_stripes;
537	refcount_t refs;
538	u64 start;
539	u64 chunk_len;
540	u64 stripe_size;
541	u64 type;
542	int io_align;
543	int io_width;
 
544	int num_stripes;
545	int sub_stripes;
546	struct btrfs_io_stripe stripes[];
 
547};
548
549#define btrfs_chunk_map_size(n) (sizeof(struct btrfs_chunk_map) + \
550				 (sizeof(struct btrfs_io_stripe) * (n)))
551
552static inline void btrfs_free_chunk_map(struct btrfs_chunk_map *map)
553{
554	if (map && refcount_dec_and_test(&map->refs)) {
555		ASSERT(RB_EMPTY_NODE(&map->rb_node));
556		kfree(map);
557	}
558}
559
560struct btrfs_balance_args;
561struct btrfs_balance_progress;
562struct btrfs_balance_control {
563	struct btrfs_balance_args data;
564	struct btrfs_balance_args meta;
565	struct btrfs_balance_args sys;
566
567	u64 flags;
568
569	struct btrfs_balance_progress stat;
570};
571
572/*
573 * Search for a given device by the set parameters
574 */
575struct btrfs_dev_lookup_args {
576	u64 devid;
577	u8 *uuid;
578	u8 *fsid;
579	bool missing;
580};
581
582/* We have to initialize to -1 because BTRFS_DEV_REPLACE_DEVID is 0 */
583#define BTRFS_DEV_LOOKUP_ARGS_INIT { .devid = (u64)-1 }
584
585#define BTRFS_DEV_LOOKUP_ARGS(name) \
586	struct btrfs_dev_lookup_args name = BTRFS_DEV_LOOKUP_ARGS_INIT
587
588enum btrfs_map_op {
589	BTRFS_MAP_READ,
590	BTRFS_MAP_WRITE,
 
591	BTRFS_MAP_GET_READ_MIRRORS,
592};
593
594static inline enum btrfs_map_op btrfs_op(struct bio *bio)
595{
596	switch (bio_op(bio)) {
 
 
597	case REQ_OP_WRITE:
598	case REQ_OP_ZONE_APPEND:
599		return BTRFS_MAP_WRITE;
600	default:
601		WARN_ON_ONCE(1);
602		fallthrough;
603	case REQ_OP_READ:
604		return BTRFS_MAP_READ;
605	}
606}
607
608static inline unsigned long btrfs_chunk_item_size(int num_stripes)
609{
610	ASSERT(num_stripes);
611	return sizeof(struct btrfs_chunk) +
612		sizeof(struct btrfs_stripe) * (num_stripes - 1);
613}
614
615/*
616 * Do the type safe conversion from stripe_nr to offset inside the chunk.
617 *
618 * @stripe_nr is u32, with left shift it can overflow u32 for chunks larger
619 * than 4G.  This does the proper type cast to avoid overflow.
620 */
621static inline u64 btrfs_stripe_nr_to_offset(u32 stripe_nr)
622{
623	return (u64)stripe_nr << BTRFS_STRIPE_LEN_SHIFT;
624}
625
626void btrfs_get_bioc(struct btrfs_io_context *bioc);
627void btrfs_put_bioc(struct btrfs_io_context *bioc);
628int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
629		    u64 logical, u64 *length,
630		    struct btrfs_io_context **bioc_ret,
631		    struct btrfs_io_stripe *smap, int *mirror_num_ret);
632int btrfs_map_repair_block(struct btrfs_fs_info *fs_info,
633			   struct btrfs_io_stripe *smap, u64 logical,
634			   u32 length, int mirror_num);
635struct btrfs_discard_stripe *btrfs_map_discard(struct btrfs_fs_info *fs_info,
636					       u64 logical, u64 *length_ret,
637					       u32 *num_stripes);
638int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
639int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
640struct btrfs_block_group *btrfs_create_chunk(struct btrfs_trans_handle *trans,
641					    u64 type);
642void btrfs_mapping_tree_free(struct btrfs_fs_info *fs_info);
 
643int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
644		       blk_mode_t flags, void *holder);
645struct btrfs_device *btrfs_scan_one_device(const char *path, blk_mode_t flags,
646					   bool mount_arg_dev);
647int btrfs_forget_devices(dev_t devt);
648void btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
649void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices);
650void btrfs_assign_next_active_device(struct btrfs_device *device,
651				     struct btrfs_device *this_dev);
652struct btrfs_device *btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info,
653						  u64 devid,
654						  const char *devpath);
655int btrfs_get_dev_args_from_path(struct btrfs_fs_info *fs_info,
656				 struct btrfs_dev_lookup_args *args,
657				 const char *path);
658struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
659					const u64 *devid, const u8 *uuid,
660					const char *path);
661void btrfs_put_dev_args_from_path(struct btrfs_dev_lookup_args *args);
662int btrfs_rm_device(struct btrfs_fs_info *fs_info,
663		    struct btrfs_dev_lookup_args *args,
664		    struct bdev_handle **bdev_handle);
665void __exit btrfs_cleanup_fs_uuids(void);
666int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
667int btrfs_grow_device(struct btrfs_trans_handle *trans,
668		      struct btrfs_device *device, u64 new_size);
669struct btrfs_device *btrfs_find_device(const struct btrfs_fs_devices *fs_devices,
670				       const struct btrfs_dev_lookup_args *args);
671int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
672int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
673int btrfs_balance(struct btrfs_fs_info *fs_info,
674		  struct btrfs_balance_control *bctl,
675		  struct btrfs_ioctl_balance_args *bargs);
676void btrfs_describe_block_groups(u64 flags, char *buf, u32 size_buf);
677int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
678int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
679int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
680int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset);
681int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
682int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
683int btrfs_uuid_scan_kthread(void *data);
684bool btrfs_chunk_writeable(struct btrfs_fs_info *fs_info, u64 chunk_offset);
 
 
685void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
686int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
687			struct btrfs_ioctl_get_dev_stats *stats);
688int btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
689int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
690int btrfs_run_dev_stats(struct btrfs_trans_handle *trans);
691void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev);
692void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev);
693void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev);
694int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
695			   u64 logical, u64 len);
696unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
697				    u64 logical);
698u64 btrfs_calc_stripe_length(const struct btrfs_chunk_map *map);
699int btrfs_nr_parity_stripes(u64 type);
700int btrfs_chunk_alloc_add_chunk_item(struct btrfs_trans_handle *trans,
701				     struct btrfs_block_group *bg);
702int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
703
704#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
705struct btrfs_chunk_map *btrfs_alloc_chunk_map(int num_stripes, gfp_t gfp);
706int btrfs_add_chunk_map(struct btrfs_fs_info *fs_info, struct btrfs_chunk_map *map);
707#endif
708
709struct btrfs_chunk_map *btrfs_clone_chunk_map(struct btrfs_chunk_map *map, gfp_t gfp);
710struct btrfs_chunk_map *btrfs_find_chunk_map(struct btrfs_fs_info *fs_info,
711					     u64 logical, u64 length);
712struct btrfs_chunk_map *btrfs_find_chunk_map_nolock(struct btrfs_fs_info *fs_info,
713						    u64 logical, u64 length);
714struct btrfs_chunk_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
715					    u64 logical, u64 length);
716void btrfs_remove_chunk_map(struct btrfs_fs_info *fs_info, struct btrfs_chunk_map *map);
717void btrfs_release_disk_super(struct btrfs_super_block *super);
718
719static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
720				      int index)
721{
722	atomic_inc(dev->dev_stat_values + index);
723	/*
724	 * This memory barrier orders stores updating statistics before stores
725	 * updating dev_stats_ccnt.
726	 *
727	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
728	 */
729	smp_mb__before_atomic();
730	atomic_inc(&dev->dev_stats_ccnt);
731}
732
733static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
734				      int index)
735{
736	return atomic_read(dev->dev_stat_values + index);
737}
738
739static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
740						int index)
741{
742	int ret;
743
744	ret = atomic_xchg(dev->dev_stat_values + index, 0);
745	/*
746	 * atomic_xchg implies a full memory barriers as per atomic_t.txt:
747	 * - RMW operations that have a return value are fully ordered;
748	 *
749	 * This implicit memory barriers is paired with the smp_rmb in
750	 * btrfs_run_dev_stats
751	 */
752	atomic_inc(&dev->dev_stats_ccnt);
753	return ret;
754}
755
756static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
757				      int index, unsigned long val)
758{
759	atomic_set(dev->dev_stat_values + index, val);
760	/*
761	 * This memory barrier orders stores updating statistics before stores
762	 * updating dev_stats_ccnt.
763	 *
764	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
765	 */
766	smp_mb__before_atomic();
767	atomic_inc(&dev->dev_stats_ccnt);
768}
769
770static inline const char *btrfs_dev_name(const struct btrfs_device *device)
 
 
 
 
771{
772	if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
773		return "<missing disk>";
774	else
775		return rcu_str_deref(device->name);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
776}
777
778void btrfs_commit_device_sizes(struct btrfs_transaction *trans);
779
780struct list_head * __attribute_const__ btrfs_get_fs_uuids(void);
 
 
781bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
782					struct btrfs_device *failing_dev);
783void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
784			       struct block_device *bdev,
785			       const char *device_path);
786
787enum btrfs_raid_types __attribute_const__ btrfs_bg_flags_to_raid_index(u64 flags);
788int btrfs_bg_type_to_factor(u64 flags);
789const char *btrfs_bg_type_to_raid_name(u64 flags);
790int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
791bool btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical);
792
793bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);
794u8 *btrfs_sb_fsid_ptr(struct btrfs_super_block *sb);
795
796#endif
v5.9
  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
 54struct btrfs_device {
 55	struct list_head dev_list; /* device_list_mutex */
 56	struct list_head dev_alloc_list; /* chunk mutex */
 57	struct list_head post_commit_list; /* chunk mutex */
 58	struct btrfs_fs_devices *fs_devices;
 59	struct btrfs_fs_info *fs_info;
 60
 61	struct rcu_string *name;
 62
 63	u64 generation;
 64
 
 65	struct block_device *bdev;
 66
 67	/* the mode sent to blkdev_get */
 68	fmode_t mode;
 69
 
 
 
 
 
 70	unsigned long dev_state;
 71	blk_status_t last_flush_error;
 72
 73#ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
 74	seqcount_t data_seqcount;
 75#endif
 76
 77	/* the internal btrfs device id */
 78	u64 devid;
 79
 80	/* size of the device in memory */
 81	u64 total_bytes;
 82
 83	/* size of the device on disk */
 84	u64 disk_total_bytes;
 85
 86	/* bytes used */
 87	u64 bytes_used;
 88
 89	/* optimal io alignment for this device */
 90	u32 io_align;
 91
 92	/* optimal io width for this device */
 93	u32 io_width;
 94	/* type and info about this device */
 95	u64 type;
 96
 97	/* minimal io size for this device */
 98	u32 sector_size;
 99
100	/* physical drive uuid (or lvm uuid) */
101	u8 uuid[BTRFS_UUID_SIZE];
102
103	/*
104	 * size of the device on the current transaction
105	 *
106	 * This variant is update when committing the transaction,
107	 * and protected by chunk mutex
108	 */
109	u64 commit_total_bytes;
110
111	/* bytes used on the current transaction */
112	u64 commit_bytes_used;
113
114	/* for sending down flush barriers */
115	struct bio *flush_bio;
116	struct completion flush_wait;
117
118	/* per-device scrub information */
119	struct scrub_ctx *scrub_ctx;
120
121	/* readahead state */
122	atomic_t reada_in_flight;
123	u64 reada_next;
124	struct reada_zone *reada_curr_zone;
125	struct radix_tree_root reada_zones;
126	struct radix_tree_root reada_extents;
127
128	/* disk I/O failure stats. For detailed description refer to
129	 * enum btrfs_dev_stat_values in ioctl.h */
130	int dev_stats_valid;
131
132	/* Counter to record the change of device stats */
133	atomic_t dev_stats_ccnt;
134	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
135
136	struct extent_io_tree alloc_state;
137
138	struct completion kobj_unregister;
139	/* For sysfs/FSID/devinfo/devid/ */
140	struct kobject devid_kobj;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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)					\
149static inline u64							\
150btrfs_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									\
162static inline void							\
163btrfs_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_PREEMPTION)
172#define BTRFS_DEVICE_GETSET_FUNCS(name)					\
173static inline u64							\
174btrfs_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									\
184static inline void							\
185btrfs_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)					\
193static inline u64							\
194btrfs_device_get_##name(const struct btrfs_device *dev)			\
195{									\
196	return dev->name;						\
197}									\
198									\
199static inline void							\
200btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
201{									\
202	dev->name = size;						\
203}
204#endif
205
206BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
207BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
208BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
209
210enum btrfs_chunk_allocation_policy {
211	BTRFS_CHUNK_ALLOC_REGULAR,
 
 
 
 
 
 
 
 
 
 
 
212};
213
214struct btrfs_fs_devices {
215	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
216	u8 metadata_uuid[BTRFS_FSID_SIZE];
217	bool fsid_change;
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
227	/* Highest generation number of seen devices */
228	u64 latest_generation;
229
230	struct block_device *latest_bdev;
 
 
 
 
231
232	/* all of the devices in the FS, protected by a mutex
233	 * so we can safely walk it to write out the supers without
234	 * worrying about add/remove by the multi-device code.
235	 * Scrubbing super can kick off supers writing by holding
236	 * this mutex lock.
237	 */
238	struct mutex device_list_mutex;
239
240	/* List of all devices, protected by device_list_mutex */
241	struct list_head devices;
242
243	/*
244	 * Devices which can satisfy space allocation. Protected by
245	 * chunk_mutex
246	 */
247	struct list_head alloc_list;
248
249	struct btrfs_fs_devices *seed;
250	bool seeding;
251
 
252	int opened;
253
254	/* set when we find or add a device that doesn't have the
255	 * nonrot flag set
256	 */
257	bool rotating;
 
 
 
 
 
 
258
259	struct btrfs_fs_info *fs_info;
260	/* sysfs kobjects */
261	struct kobject fsid_kobj;
262	struct kobject *devices_kobj;
263	struct kobject *devinfo_kobj;
264	struct completion kobj_unregister;
265
266	enum btrfs_chunk_allocation_policy chunk_alloc_policy;
 
 
 
267};
268
269#define BTRFS_BIO_INLINE_CSUM_SIZE	64
270
271#define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info)	\
272			- sizeof(struct btrfs_chunk))		\
273			/ sizeof(struct btrfs_stripe) + 1)
274
275#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE	\
276				- 2 * sizeof(struct btrfs_disk_key)	\
277				- 2 * sizeof(struct btrfs_chunk))	\
278				/ sizeof(struct btrfs_stripe) + 1)
279
280/*
281 * we need the mirror number and stripe index to be passed around
282 * the call chain while we are processing end_io (especially errors).
283 * Really, what we need is a btrfs_bio structure that has this info
284 * and is properly sized with its stripe array, but we're not there
285 * quite yet.  We have our own btrfs bioset, and all of the bios
286 * we allocate are actually btrfs_io_bios.  We'll cram as much of
287 * struct btrfs_bio as we can into this over time.
288 */
289struct btrfs_io_bio {
290	unsigned int mirror_num;
291	struct btrfs_device *device;
292	u64 logical;
293	u8 *csum;
294	u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
295	struct bvec_iter iter;
296	/*
297	 * This member must come last, bio_alloc_bioset will allocate enough
298	 * bytes for entire btrfs_io_bio but relies on bio being last.
299	 */
300	struct bio bio;
301};
302
303static inline struct btrfs_io_bio *btrfs_io_bio(struct bio *bio)
304{
305	return container_of(bio, struct btrfs_io_bio, bio);
306}
307
308static inline void btrfs_io_bio_free_csum(struct btrfs_io_bio *io_bio)
309{
310	if (io_bio->csum != io_bio->csum_inline) {
311		kfree(io_bio->csum);
312		io_bio->csum = NULL;
313	}
314}
315
316struct btrfs_bio_stripe {
317	struct btrfs_device *dev;
318	u64 physical;
319	u64 length; /* only used for discard mappings */
320};
321
322struct btrfs_bio {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
323	refcount_t refs;
324	atomic_t stripes_pending;
325	struct btrfs_fs_info *fs_info;
326	u64 map_type; /* get from map_lookup->type */
327	bio_end_io_t *end_io;
328	struct bio *orig_bio;
329	void *private;
330	atomic_t error;
331	int max_errors;
332	int num_stripes;
333	int mirror_num;
334	int num_tgtdevs;
335	int *tgtdev_map;
336	/*
337	 * logical block numbers for the start of each stripe
338	 * The last one or two are p/q.  These are sorted,
339	 * so raid_map[0] is the start of our full stripe
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
340	 */
341	u64 *raid_map;
342	struct btrfs_bio_stripe stripes[];
343};
344
345struct btrfs_device_info {
346	struct btrfs_device *dev;
347	u64 dev_offset;
348	u64 max_avail;
349	u64 total_avail;
350};
351
352struct btrfs_raid_attr {
353	u8 sub_stripes;		/* sub_stripes info for map */
354	u8 dev_stripes;		/* stripes per dev */
355	u8 devs_max;		/* max devs to use */
356	u8 devs_min;		/* min devs needed */
357	u8 tolerated_failures;	/* max tolerated fail devs */
358	u8 devs_increment;	/* ndevs has to be a multiple of this */
359	u8 ncopies;		/* how many copies to data has */
360	u8 nparity;		/* number of stripes worth of bytes to store
361				 * parity information */
362	u8 mindev_error;	/* error code if min devs requisite is unmet */
363	const char raid_name[8]; /* name of the raid */
364	u64 bg_flag;		/* block group flag of the raid */
365};
366
367extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
368
369struct map_lookup {
 
 
 
 
 
 
 
370	u64 type;
371	int io_align;
372	int io_width;
373	u64 stripe_len;
374	int num_stripes;
375	int sub_stripes;
376	int verified_stripes; /* For mount time dev extent verification */
377	struct btrfs_bio_stripe stripes[];
378};
379
380#define map_lookup_size(n) (sizeof(struct map_lookup) + \
381			    (sizeof(struct btrfs_bio_stripe) * (n)))
 
 
 
 
 
 
 
 
382
383struct btrfs_balance_args;
384struct btrfs_balance_progress;
385struct btrfs_balance_control {
386	struct btrfs_balance_args data;
387	struct btrfs_balance_args meta;
388	struct btrfs_balance_args sys;
389
390	u64 flags;
391
392	struct btrfs_balance_progress stat;
393};
394
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
395enum btrfs_map_op {
396	BTRFS_MAP_READ,
397	BTRFS_MAP_WRITE,
398	BTRFS_MAP_DISCARD,
399	BTRFS_MAP_GET_READ_MIRRORS,
400};
401
402static inline enum btrfs_map_op btrfs_op(struct bio *bio)
403{
404	switch (bio_op(bio)) {
405	case REQ_OP_DISCARD:
406		return BTRFS_MAP_DISCARD;
407	case REQ_OP_WRITE:
 
408		return BTRFS_MAP_WRITE;
409	default:
410		WARN_ON_ONCE(1);
411		fallthrough;
412	case REQ_OP_READ:
413		return BTRFS_MAP_READ;
414	}
415}
416
417void btrfs_get_bbio(struct btrfs_bio *bbio);
418void btrfs_put_bbio(struct btrfs_bio *bbio);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
419int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
420		    u64 logical, u64 *length,
421		    struct btrfs_bio **bbio_ret, int mirror_num);
422int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
423		     u64 logical, u64 *length,
424		     struct btrfs_bio **bbio_ret);
425int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
426		u64 logical, u64 len, struct btrfs_io_geometry *io_geom);
 
 
427int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
428int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
429int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 type);
430void btrfs_mapping_tree_free(struct extent_map_tree *tree);
431blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
432			   int mirror_num);
433int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
434		       fmode_t flags, void *holder);
435struct btrfs_device *btrfs_scan_one_device(const char *path,
436					   fmode_t flags, void *holder);
437int btrfs_forget_devices(const char *path);
438int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
439void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step);
440void btrfs_assign_next_active_device(struct btrfs_device *device,
441				     struct btrfs_device *this_dev);
442struct btrfs_device *btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info,
443						  u64 devid,
444						  const char *devpath);
 
 
 
445struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
446					const u64 *devid,
447					const u8 *uuid);
448void btrfs_free_device(struct btrfs_device *device);
449int btrfs_rm_device(struct btrfs_fs_info *fs_info,
450		    const char *device_path, u64 devid);
 
451void __exit btrfs_cleanup_fs_uuids(void);
452int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
453int btrfs_grow_device(struct btrfs_trans_handle *trans,
454		      struct btrfs_device *device, u64 new_size);
455struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices,
456				       u64 devid, u8 *uuid, u8 *fsid, bool seed);
457int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
458int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
459int btrfs_balance(struct btrfs_fs_info *fs_info,
460		  struct btrfs_balance_control *bctl,
461		  struct btrfs_ioctl_balance_args *bargs);
462void btrfs_describe_block_groups(u64 flags, char *buf, u32 size_buf);
463int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
464int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
465int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
 
466int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
467int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
468int btrfs_uuid_scan_kthread(void *data);
469int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset);
470int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
471			 u64 *start, u64 *max_avail);
472void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
473int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
474			struct btrfs_ioctl_get_dev_stats *stats);
475void btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
476int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
477int btrfs_run_dev_stats(struct btrfs_trans_handle *trans);
478void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev);
479void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev);
480void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev);
481int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
482			   u64 logical, u64 len);
483unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
484				    u64 logical);
485int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
486			     u64 chunk_offset, u64 chunk_size);
 
 
487int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
488struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
489				       u64 logical, u64 length);
 
 
 
 
 
 
 
 
 
 
 
 
490void btrfs_release_disk_super(struct btrfs_super_block *super);
491
492static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
493				      int index)
494{
495	atomic_inc(dev->dev_stat_values + index);
496	/*
497	 * This memory barrier orders stores updating statistics before stores
498	 * updating dev_stats_ccnt.
499	 *
500	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
501	 */
502	smp_mb__before_atomic();
503	atomic_inc(&dev->dev_stats_ccnt);
504}
505
506static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
507				      int index)
508{
509	return atomic_read(dev->dev_stat_values + index);
510}
511
512static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
513						int index)
514{
515	int ret;
516
517	ret = atomic_xchg(dev->dev_stat_values + index, 0);
518	/*
519	 * atomic_xchg implies a full memory barriers as per atomic_t.txt:
520	 * - RMW operations that have a return value are fully ordered;
521	 *
522	 * This implicit memory barriers is paired with the smp_rmb in
523	 * btrfs_run_dev_stats
524	 */
525	atomic_inc(&dev->dev_stats_ccnt);
526	return ret;
527}
528
529static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
530				      int index, unsigned long val)
531{
532	atomic_set(dev->dev_stat_values + index, val);
533	/*
534	 * This memory barrier orders stores updating statistics before stores
535	 * updating dev_stats_ccnt.
536	 *
537	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
538	 */
539	smp_mb__before_atomic();
540	atomic_inc(&dev->dev_stats_ccnt);
541}
542
543/*
544 * Convert block group flags (BTRFS_BLOCK_GROUP_*) to btrfs_raid_types, which
545 * can be used as index to access btrfs_raid_array[].
546 */
547static inline enum btrfs_raid_types btrfs_bg_flags_to_raid_index(u64 flags)
548{
549	if (flags & BTRFS_BLOCK_GROUP_RAID10)
550		return BTRFS_RAID_RAID10;
551	else if (flags & BTRFS_BLOCK_GROUP_RAID1)
552		return BTRFS_RAID_RAID1;
553	else if (flags & BTRFS_BLOCK_GROUP_RAID1C3)
554		return BTRFS_RAID_RAID1C3;
555	else if (flags & BTRFS_BLOCK_GROUP_RAID1C4)
556		return BTRFS_RAID_RAID1C4;
557	else if (flags & BTRFS_BLOCK_GROUP_DUP)
558		return BTRFS_RAID_DUP;
559	else if (flags & BTRFS_BLOCK_GROUP_RAID0)
560		return BTRFS_RAID_RAID0;
561	else if (flags & BTRFS_BLOCK_GROUP_RAID5)
562		return BTRFS_RAID_RAID5;
563	else if (flags & BTRFS_BLOCK_GROUP_RAID6)
564		return BTRFS_RAID_RAID6;
565
566	return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
567}
568
569void btrfs_commit_device_sizes(struct btrfs_transaction *trans);
570
571struct list_head * __attribute_const__ btrfs_get_fs_uuids(void);
572void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info);
573void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info);
574bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
575					struct btrfs_device *failing_dev);
576void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
577			       struct block_device *bdev,
578			       const char *device_path);
579
 
580int btrfs_bg_type_to_factor(u64 flags);
581const char *btrfs_bg_type_to_raid_name(u64 flags);
582int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
 
 
 
 
583
584#endif