1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Copyright (C) 2007 Oracle. All rights reserved.
6 #ifndef BTRFS_VOLUMES_H
7 #define BTRFS_VOLUMES_H
9 #include <linux/sort.h>
10 #include <linux/btrfs.h>
11 #include "async-thread.h"
13 #include "tree-checker.h"
14 #include "rcu-string.h"
16 #define BTRFS_MAX_DATA_CHUNK_SIZE (10ULL * SZ_1G)
18 extern struct mutex uuid_mutex;
20 #define BTRFS_STRIPE_LEN SZ_64K
21 #define BTRFS_STRIPE_LEN_SHIFT (16)
22 #define BTRFS_STRIPE_LEN_MASK (BTRFS_STRIPE_LEN - 1)
24 static_assert(const_ilog2(BTRFS_STRIPE_LEN) == BTRFS_STRIPE_LEN_SHIFT);
26 /* Used by sanity check for btrfs_raid_types. */
27 #define const_ffs(n) (__builtin_ctzll(n) + 1)
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.
35 static_assert(const_ffs(BTRFS_BLOCK_GROUP_RAID0) <
36 const_ffs(BTRFS_BLOCK_GROUP_PROFILE_MASK & ~BTRFS_BLOCK_GROUP_RAID0));
37 static_assert(const_ilog2(BTRFS_BLOCK_GROUP_RAID0) >
38 ilog2(BTRFS_BLOCK_GROUP_TYPE_MASK));
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))
44 enum btrfs_raid_types {
45 /* SINGLE is the special one as it doesn't have on-disk bit. */
46 BTRFS_RAID_SINGLE = 0,
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),
61 * Use sequence counter to get consistent device stat data on
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)
70 #define btrfs_device_data_ordered_init(device) do { } while (0)
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)
80 struct btrfs_zoned_device_info;
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;
89 struct rcu_string __rcu *name;
93 struct block_device *bdev;
95 struct btrfs_zoned_device_info *zone_info;
97 /* block device holder for blkdev_get/put */
101 * Device's major-minor number. Must be set even if the device is not
102 * opened (bdev == NULL), unless the device is missing.
105 unsigned long dev_state;
106 blk_status_t last_flush_error;
108 #ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
109 seqcount_t data_seqcount;
112 /* the internal btrfs device id */
115 /* size of the device in memory */
118 /* size of the device on disk */
119 u64 disk_total_bytes;
124 /* optimal io alignment for this device */
127 /* optimal io width for this device */
129 /* type and info about this device */
132 /* minimal io size for this device */
135 /* physical drive uuid (or lvm uuid) */
136 u8 uuid[BTRFS_UUID_SIZE];
139 * size of the device on the current transaction
141 * This variant is update when committing the transaction,
142 * and protected by chunk mutex
144 u64 commit_total_bytes;
146 /* bytes used on the current transaction */
147 u64 commit_bytes_used;
149 /* Bio used for flushing device barriers */
150 struct bio flush_bio;
151 struct completion flush_wait;
153 /* per-device scrub information */
154 struct scrub_ctx *scrub_ctx;
156 /* disk I/O failure stats. For detailed description refer to
157 * enum btrfs_dev_stat_values in ioctl.h */
160 /* Counter to record the change of device stats */
161 atomic_t dev_stats_ccnt;
162 atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
164 struct extent_io_tree alloc_state;
166 struct completion kobj_unregister;
167 /* For sysfs/FSID/devinfo/devid/ */
168 struct kobject devid_kobj;
170 /* Bandwidth limit for scrub, in bytes */
175 * Block group or device which contains an active swapfile. Used for preventing
176 * unsafe operations while a swapfile is active.
178 * These are sorted on (ptr, inode) (note that a block group or device can
179 * contain more than one swapfile). We compare the pointer values because we
180 * don't actually care what the object is, we just need a quick check whether
181 * the object exists in the rbtree.
183 struct btrfs_swapfile_pin {
188 * If true, ptr points to a struct btrfs_block_group. Otherwise, ptr
189 * points to a struct btrfs_device.
193 * Only used when 'is_block_group' is true and it is the number of
194 * extents used by a swapfile for this block group ('ptr' field).
200 * If we read those variants at the context of their own lock, we needn't
201 * use the following helpers, reading them directly is safe.
203 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
204 #define BTRFS_DEVICE_GETSET_FUNCS(name) \
206 btrfs_device_get_##name(const struct btrfs_device *dev) \
212 seq = read_seqcount_begin(&dev->data_seqcount); \
214 } while (read_seqcount_retry(&dev->data_seqcount, seq)); \
219 btrfs_device_set_##name(struct btrfs_device *dev, u64 size) \
222 write_seqcount_begin(&dev->data_seqcount); \
224 write_seqcount_end(&dev->data_seqcount); \
227 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
228 #define BTRFS_DEVICE_GETSET_FUNCS(name) \
230 btrfs_device_get_##name(const struct btrfs_device *dev) \
241 btrfs_device_set_##name(struct btrfs_device *dev, u64 size) \
248 #define BTRFS_DEVICE_GETSET_FUNCS(name) \
250 btrfs_device_get_##name(const struct btrfs_device *dev) \
256 btrfs_device_set_##name(struct btrfs_device *dev, u64 size) \
262 BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
263 BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
264 BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
266 enum btrfs_chunk_allocation_policy {
267 BTRFS_CHUNK_ALLOC_REGULAR,
268 BTRFS_CHUNK_ALLOC_ZONED,
272 * Read policies for mirrored block group profiles, read picks the stripe based
275 enum btrfs_read_policy {
276 /* Use process PID to choose the stripe */
277 BTRFS_READ_POLICY_PID,
278 BTRFS_NR_READ_POLICY,
281 struct btrfs_fs_devices {
282 u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
285 * UUID written into the btree blocks:
287 * - If metadata_uuid != fsid then super block must have
288 * BTRFS_FEATURE_INCOMPAT_METADATA_UUID flag set.
290 * - Following shall be true at all times:
291 * - metadata_uuid == btrfs_header::fsid
292 * - metadata_uuid == btrfs_dev_item::fsid
294 * - Relations between fsid and metadata_uuid in sb and fs_devices:
296 * fs_devices->fsid == fs_devices->metadata_uuid == sb->fsid
297 * sb->metadata_uuid == 0
299 * - When the BTRFS_FEATURE_INCOMPAT_METADATA_UUID flag is set:
300 * fs_devices->fsid == sb->fsid
301 * fs_devices->metadata_uuid == sb->metadata_uuid
303 * - When in-memory fs_devices->temp_fsid is true
304 * fs_devices->fsid = random
305 * fs_devices->metadata_uuid == sb->fsid
307 u8 metadata_uuid[BTRFS_FSID_SIZE];
309 struct list_head fs_list;
312 * Number of devices under this fsid including missing and
313 * replace-target device and excludes seed devices.
318 * The number of devices that successfully opened, including
319 * replace-target, excludes seed devices.
323 /* The number of devices that are under the chunk allocation list. */
326 /* Count of missing devices under this fsid excluding seed device. */
331 * Count of devices from btrfs_super_block::num_devices for this fsid,
332 * which includes the seed device, excludes the transient replace-target
337 /* Highest generation number of seen devices */
338 u64 latest_generation;
341 * The mount device or a device with highest generation after removal
344 struct btrfs_device *latest_dev;
347 * All of the devices in the filesystem, protected by a mutex so we can
348 * safely walk it to write out the super blocks without worrying about
349 * adding/removing by the multi-device code. Scrubbing super block can
350 * kick off supers writing by holding this mutex lock.
352 struct mutex device_list_mutex;
354 /* List of all devices, protected by device_list_mutex */
355 struct list_head devices;
357 /* Devices which can satisfy space allocation. Protected by * chunk_mutex. */
358 struct list_head alloc_list;
360 struct list_head seed_list;
362 /* Count fs-devices opened. */
365 /* Set when we find or add a device that doesn't have the nonrot flag set. */
367 /* Devices support TRIM/discard commands. */
369 /* The filesystem is a seed filesystem. */
371 /* The mount needs to use a randomly generated fsid. */
374 struct btrfs_fs_info *fs_info;
376 struct kobject fsid_kobj;
377 struct kobject *devices_kobj;
378 struct kobject *devinfo_kobj;
379 struct completion kobj_unregister;
381 enum btrfs_chunk_allocation_policy chunk_alloc_policy;
383 /* Policy used to read the mirrored stripes. */
384 enum btrfs_read_policy read_policy;
387 #define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info) \
388 - sizeof(struct btrfs_chunk)) \
389 / sizeof(struct btrfs_stripe) + 1)
391 #define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE \
392 - 2 * sizeof(struct btrfs_disk_key) \
393 - 2 * sizeof(struct btrfs_chunk)) \
394 / sizeof(struct btrfs_stripe) + 1)
396 struct btrfs_io_stripe {
397 struct btrfs_device *dev;
402 /* For the endio handler. */
403 struct btrfs_io_context *bioc;
406 struct btrfs_discard_stripe {
407 struct btrfs_device *dev;
413 * Context for IO subsmission for device stripe.
415 * - Track the unfinished mirrors for mirror based profiles
416 * Mirror based profiles are SINGLE/DUP/RAID1/RAID10.
418 * - Contain the logical -> physical mapping info
419 * Used by submit_stripe_bio() for mapping logical bio
420 * into physical device address.
422 * - Contain device replace info
423 * Used by handle_ops_on_dev_replace() to copy logical bios
424 * into the new device.
426 * - Contain RAID56 full stripe logical bytenrs
428 struct btrfs_io_context {
430 struct btrfs_fs_info *fs_info;
431 u64 map_type; /* get from map_lookup->type */
432 struct bio *orig_bio;
438 /* Raid stripe tree ordered entry. */
439 struct list_head rst_ordered_entry;
442 * The total number of stripes, including the extra duplicated
443 * stripe for replace.
448 * The mirror_num of this bioc.
450 * This is for reads which use 0 as mirror_num, thus we should return a
451 * valid mirror_num (>0) for the reader.
456 * The following two members are for dev-replace case only.
458 * @replace_nr_stripes: Number of duplicated stripes which need to be
459 * written to replace target.
460 * Should be <= 2 (2 for DUP, otherwise <= 1).
461 * @replace_stripe_src: The array indicates where the duplicated stripes
464 * The @replace_stripe_src[] array is mostly for RAID56 cases.
465 * As non-RAID56 stripes share the same contents of the mapped range,
466 * thus no need to bother where the duplicated ones are from.
468 * But for RAID56 case, all stripes contain different contents, thus
469 * we need a way to know the mapping.
471 * There is an example for the two members, using a RAID5 write:
473 * num_stripes: 4 (3 + 1 duplicated write)
474 * stripes[0]: dev = devid 1, physical = X
475 * stripes[1]: dev = devid 2, physical = Y
476 * stripes[2]: dev = devid 3, physical = Z
477 * stripes[3]: dev = devid 0, physical = Y
479 * replace_nr_stripes = 1
480 * replace_stripe_src = 1 <- Means stripes[1] is involved in replace.
481 * The duplicated stripe index would be
482 * (@num_stripes - 1).
484 * Note, that we can still have cases replace_nr_stripes = 2 for DUP.
485 * In that case, all stripes share the same content, thus we don't
486 * need to bother @replace_stripe_src value at all.
488 u16 replace_nr_stripes;
489 s16 replace_stripe_src;
491 * Logical bytenr of the full stripe start, only for RAID56 cases.
493 * When this value is set to other than (u64)-1, the stripes[] should
494 * follow this pattern:
496 * (real_stripes = num_stripes - replace_nr_stripes)
497 * (data_stripes = (is_raid6) ? (real_stripes - 2) : (real_stripes - 1))
499 * stripes[0]: The first data stripe
500 * stripes[1]: The second data stripe
502 * stripes[data_stripes - 1]: The last data stripe
503 * stripes[data_stripes]: The P stripe
504 * stripes[data_stripes + 1]: The Q stripe (only for RAID6).
506 u64 full_stripe_logical;
507 struct btrfs_io_stripe stripes[];
510 struct btrfs_device_info {
511 struct btrfs_device *dev;
517 struct btrfs_raid_attr {
518 u8 sub_stripes; /* sub_stripes info for map */
519 u8 dev_stripes; /* stripes per dev */
520 u8 devs_max; /* max devs to use */
521 u8 devs_min; /* min devs needed */
522 u8 tolerated_failures; /* max tolerated fail devs */
523 u8 devs_increment; /* ndevs has to be a multiple of this */
524 u8 ncopies; /* how many copies to data has */
525 u8 nparity; /* number of stripes worth of bytes to store
526 * parity information */
527 u8 mindev_error; /* error code if min devs requisite is unmet */
528 const char raid_name[8]; /* name of the raid */
529 u64 bg_flag; /* block group flag of the raid */
532 extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
540 int verified_stripes; /* For mount time dev extent verification */
541 struct btrfs_io_stripe stripes[];
544 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
545 (sizeof(struct btrfs_io_stripe) * (n)))
547 struct btrfs_balance_args;
548 struct btrfs_balance_progress;
549 struct btrfs_balance_control {
550 struct btrfs_balance_args data;
551 struct btrfs_balance_args meta;
552 struct btrfs_balance_args sys;
556 struct btrfs_balance_progress stat;
560 * Search for a given device by the set parameters
562 struct btrfs_dev_lookup_args {
569 /* We have to initialize to -1 because BTRFS_DEV_REPLACE_DEVID is 0 */
570 #define BTRFS_DEV_LOOKUP_ARGS_INIT { .devid = (u64)-1 }
572 #define BTRFS_DEV_LOOKUP_ARGS(name) \
573 struct btrfs_dev_lookup_args name = BTRFS_DEV_LOOKUP_ARGS_INIT
578 BTRFS_MAP_GET_READ_MIRRORS,
581 static inline enum btrfs_map_op btrfs_op(struct bio *bio)
583 switch (bio_op(bio)) {
585 case REQ_OP_ZONE_APPEND:
586 return BTRFS_MAP_WRITE;
591 return BTRFS_MAP_READ;
595 static inline unsigned long btrfs_chunk_item_size(int num_stripes)
598 return sizeof(struct btrfs_chunk) +
599 sizeof(struct btrfs_stripe) * (num_stripes - 1);
603 * Do the type safe converstion from stripe_nr to offset inside the chunk.
605 * @stripe_nr is u32, with left shift it can overflow u32 for chunks larger
606 * than 4G. This does the proper type cast to avoid overflow.
608 static inline u64 btrfs_stripe_nr_to_offset(u32 stripe_nr)
610 return (u64)stripe_nr << BTRFS_STRIPE_LEN_SHIFT;
613 void btrfs_get_bioc(struct btrfs_io_context *bioc);
614 void btrfs_put_bioc(struct btrfs_io_context *bioc);
615 int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
616 u64 logical, u64 *length,
617 struct btrfs_io_context **bioc_ret,
618 struct btrfs_io_stripe *smap, int *mirror_num_ret);
619 int btrfs_map_repair_block(struct btrfs_fs_info *fs_info,
620 struct btrfs_io_stripe *smap, u64 logical,
621 u32 length, int mirror_num);
622 struct btrfs_discard_stripe *btrfs_map_discard(struct btrfs_fs_info *fs_info,
623 u64 logical, u64 *length_ret,
625 int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
626 int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
627 struct btrfs_block_group *btrfs_create_chunk(struct btrfs_trans_handle *trans,
629 void btrfs_mapping_tree_free(struct extent_map_tree *tree);
630 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
631 blk_mode_t flags, void *holder);
632 struct btrfs_device *btrfs_scan_one_device(const char *path, blk_mode_t flags,
634 int btrfs_forget_devices(dev_t devt);
635 void btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
636 void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices);
637 void btrfs_assign_next_active_device(struct btrfs_device *device,
638 struct btrfs_device *this_dev);
639 struct btrfs_device *btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info,
641 const char *devpath);
642 int btrfs_get_dev_args_from_path(struct btrfs_fs_info *fs_info,
643 struct btrfs_dev_lookup_args *args,
645 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
646 const u64 *devid, const u8 *uuid,
648 void btrfs_put_dev_args_from_path(struct btrfs_dev_lookup_args *args);
649 int btrfs_rm_device(struct btrfs_fs_info *fs_info,
650 struct btrfs_dev_lookup_args *args,
651 struct block_device **bdev, void **holder);
652 void __exit btrfs_cleanup_fs_uuids(void);
653 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
654 int btrfs_grow_device(struct btrfs_trans_handle *trans,
655 struct btrfs_device *device, u64 new_size);
656 struct btrfs_device *btrfs_find_device(const struct btrfs_fs_devices *fs_devices,
657 const struct btrfs_dev_lookup_args *args);
658 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
659 int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
660 int btrfs_balance(struct btrfs_fs_info *fs_info,
661 struct btrfs_balance_control *bctl,
662 struct btrfs_ioctl_balance_args *bargs);
663 void btrfs_describe_block_groups(u64 flags, char *buf, u32 size_buf);
664 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
665 int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
666 int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
667 int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset);
668 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
669 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
670 int btrfs_uuid_scan_kthread(void *data);
671 bool btrfs_chunk_writeable(struct btrfs_fs_info *fs_info, u64 chunk_offset);
672 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
673 int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
674 struct btrfs_ioctl_get_dev_stats *stats);
675 int btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
676 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
677 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans);
678 void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev);
679 void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev);
680 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev);
681 int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
682 u64 logical, u64 len);
683 unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
685 u64 btrfs_calc_stripe_length(const struct extent_map *em);
686 int btrfs_nr_parity_stripes(u64 type);
687 int btrfs_chunk_alloc_add_chunk_item(struct btrfs_trans_handle *trans,
688 struct btrfs_block_group *bg);
689 int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
690 struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
691 u64 logical, u64 length);
692 void btrfs_release_disk_super(struct btrfs_super_block *super);
694 static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
697 atomic_inc(dev->dev_stat_values + index);
699 * This memory barrier orders stores updating statistics before stores
700 * updating dev_stats_ccnt.
702 * It pairs with smp_rmb() in btrfs_run_dev_stats().
704 smp_mb__before_atomic();
705 atomic_inc(&dev->dev_stats_ccnt);
708 static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
711 return atomic_read(dev->dev_stat_values + index);
714 static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
719 ret = atomic_xchg(dev->dev_stat_values + index, 0);
721 * atomic_xchg implies a full memory barriers as per atomic_t.txt:
722 * - RMW operations that have a return value are fully ordered;
724 * This implicit memory barriers is paired with the smp_rmb in
725 * btrfs_run_dev_stats
727 atomic_inc(&dev->dev_stats_ccnt);
731 static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
732 int index, unsigned long val)
734 atomic_set(dev->dev_stat_values + index, val);
736 * This memory barrier orders stores updating statistics before stores
737 * updating dev_stats_ccnt.
739 * It pairs with smp_rmb() in btrfs_run_dev_stats().
741 smp_mb__before_atomic();
742 atomic_inc(&dev->dev_stats_ccnt);
745 static inline const char *btrfs_dev_name(const struct btrfs_device *device)
747 if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
748 return "<missing disk>";
750 return rcu_str_deref(device->name);
753 void btrfs_commit_device_sizes(struct btrfs_transaction *trans);
755 struct list_head * __attribute_const__ btrfs_get_fs_uuids(void);
756 bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
757 struct btrfs_device *failing_dev);
758 void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
759 struct block_device *bdev,
760 const char *device_path);
762 enum btrfs_raid_types __attribute_const__ btrfs_bg_flags_to_raid_index(u64 flags);
763 int btrfs_bg_type_to_factor(u64 flags);
764 const char *btrfs_bg_type_to_raid_name(u64 flags);
765 int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
766 bool btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical);
768 bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);
769 u8 *btrfs_sb_fsid_ptr(struct btrfs_super_block *sb);