xref: /linux/fs/btrfs/fs.h (revision 55f1b540d893da740a81200450014c45a8103f54)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #ifndef BTRFS_FS_H
4 #define BTRFS_FS_H
5 
6 #include <linux/blkdev.h>
7 #include <linux/sizes.h>
8 #include <linux/time64.h>
9 #include <linux/compiler.h>
10 #include <linux/math.h>
11 #include <linux/atomic.h>
12 #include <linux/percpu_counter.h>
13 #include <linux/completion.h>
14 #include <linux/lockdep.h>
15 #include <linux/spinlock.h>
16 #include <linux/mutex.h>
17 #include <linux/rwlock_types.h>
18 #include <linux/rwsem.h>
19 #include <linux/semaphore.h>
20 #include <linux/list.h>
21 #include <linux/radix-tree.h>
22 #include <linux/workqueue.h>
23 #include <linux/wait.h>
24 #include <linux/wait_bit.h>
25 #include <linux/sched.h>
26 #include <linux/rbtree.h>
27 #include <uapi/linux/btrfs.h>
28 #include <uapi/linux/btrfs_tree.h>
29 #include "extent-io-tree.h"
30 #include "async-thread.h"
31 #include "block-rsv.h"
32 
33 struct inode;
34 struct super_block;
35 struct kobject;
36 struct reloc_control;
37 struct crypto_shash;
38 struct ulist;
39 struct btrfs_device;
40 struct btrfs_block_group;
41 struct btrfs_root;
42 struct btrfs_fs_devices;
43 struct btrfs_transaction;
44 struct btrfs_delayed_root;
45 struct btrfs_balance_control;
46 struct btrfs_subpage_info;
47 struct btrfs_stripe_hash_table;
48 struct btrfs_space_info;
49 
50 #define BTRFS_MAX_EXTENT_SIZE SZ_128M
51 
52 #define BTRFS_OLDEST_GENERATION	0ULL
53 
54 #define BTRFS_EMPTY_DIR_SIZE 0
55 
56 #define BTRFS_DIRTY_METADATA_THRESH		SZ_32M
57 
58 #define BTRFS_SUPER_INFO_OFFSET			SZ_64K
59 #define BTRFS_SUPER_INFO_SIZE			4096
60 static_assert(sizeof(struct btrfs_super_block) == BTRFS_SUPER_INFO_SIZE);
61 
62 /*
63  * Number of metadata items necessary for an unlink operation:
64  *
65  * 1 for the possible orphan item
66  * 1 for the dir item
67  * 1 for the dir index
68  * 1 for the inode ref
69  * 1 for the inode
70  * 1 for the parent inode
71  */
72 #define BTRFS_UNLINK_METADATA_UNITS		6
73 
74 /*
75  * The reserved space at the beginning of each device.  It covers the primary
76  * super block and leaves space for potential use by other tools like
77  * bootloaders or to lower potential damage of accidental overwrite.
78  */
79 #define BTRFS_DEVICE_RANGE_RESERVED			(SZ_1M)
80 /*
81  * Runtime (in-memory) states of filesystem
82  */
83 enum {
84 	/*
85 	 * Filesystem is being remounted, allow to skip some operations, like
86 	 * defrag
87 	 */
88 	BTRFS_FS_STATE_REMOUNTING,
89 	/* Filesystem in RO mode */
90 	BTRFS_FS_STATE_RO,
91 	/* Track if a transaction abort has been reported on this filesystem */
92 	BTRFS_FS_STATE_TRANS_ABORTED,
93 	/*
94 	 * Bio operations should be blocked on this filesystem because a source
95 	 * or target device is being destroyed as part of a device replace
96 	 */
97 	BTRFS_FS_STATE_DEV_REPLACING,
98 	/* The btrfs_fs_info created for self-tests */
99 	BTRFS_FS_STATE_DUMMY_FS_INFO,
100 
101 	/* Checksum errors are ignored. */
102 	BTRFS_FS_STATE_NO_DATA_CSUMS,
103 	BTRFS_FS_STATE_SKIP_META_CSUMS,
104 
105 	/* Indicates there was an error cleaning up a log tree. */
106 	BTRFS_FS_STATE_LOG_CLEANUP_ERROR,
107 
108 	BTRFS_FS_STATE_COUNT
109 };
110 
111 enum {
112 	BTRFS_FS_CLOSING_START,
113 	BTRFS_FS_CLOSING_DONE,
114 	BTRFS_FS_LOG_RECOVERING,
115 	BTRFS_FS_OPEN,
116 	BTRFS_FS_QUOTA_ENABLED,
117 	BTRFS_FS_UPDATE_UUID_TREE_GEN,
118 	BTRFS_FS_CREATING_FREE_SPACE_TREE,
119 	BTRFS_FS_BTREE_ERR,
120 	BTRFS_FS_LOG1_ERR,
121 	BTRFS_FS_LOG2_ERR,
122 	BTRFS_FS_QUOTA_OVERRIDE,
123 	/* Used to record internally whether fs has been frozen */
124 	BTRFS_FS_FROZEN,
125 	/*
126 	 * Indicate that balance has been set up from the ioctl and is in the
127 	 * main phase. The fs_info::balance_ctl is initialized.
128 	 */
129 	BTRFS_FS_BALANCE_RUNNING,
130 
131 	/*
132 	 * Indicate that relocation of a chunk has started, it's set per chunk
133 	 * and is toggled between chunks.
134 	 */
135 	BTRFS_FS_RELOC_RUNNING,
136 
137 	/* Indicate that the cleaner thread is awake and doing something. */
138 	BTRFS_FS_CLEANER_RUNNING,
139 
140 	/*
141 	 * The checksumming has an optimized version and is considered fast,
142 	 * so we don't need to offload checksums to workqueues.
143 	 */
144 	BTRFS_FS_CSUM_IMPL_FAST,
145 
146 	/* Indicate that the discard workqueue can service discards. */
147 	BTRFS_FS_DISCARD_RUNNING,
148 
149 	/* Indicate that we need to cleanup space cache v1 */
150 	BTRFS_FS_CLEANUP_SPACE_CACHE_V1,
151 
152 	/* Indicate that we can't trust the free space tree for caching yet */
153 	BTRFS_FS_FREE_SPACE_TREE_UNTRUSTED,
154 
155 	/* Indicate whether there are any tree modification log users */
156 	BTRFS_FS_TREE_MOD_LOG_USERS,
157 
158 	/* Indicate that we want the transaction kthread to commit right now. */
159 	BTRFS_FS_COMMIT_TRANS,
160 
161 	/* Indicate we have half completed snapshot deletions pending. */
162 	BTRFS_FS_UNFINISHED_DROPS,
163 
164 	/* Indicate we have to finish a zone to do next allocation. */
165 	BTRFS_FS_NEED_ZONE_FINISH,
166 
167 	/* Indicate that we want to commit the transaction. */
168 	BTRFS_FS_NEED_TRANS_COMMIT,
169 
170 	/* This is set when active zone tracking is needed. */
171 	BTRFS_FS_ACTIVE_ZONE_TRACKING,
172 
173 	/*
174 	 * Indicate if we have some features changed, this is mostly for
175 	 * cleaner thread to update the sysfs interface.
176 	 */
177 	BTRFS_FS_FEATURE_CHANGED,
178 
179 	/*
180 	 * Indicate that we have found a tree block which is only aligned to
181 	 * sectorsize, but not to nodesize.  This should be rare nowadays.
182 	 */
183 	BTRFS_FS_UNALIGNED_TREE_BLOCK,
184 
185 #if BITS_PER_LONG == 32
186 	/* Indicate if we have error/warn message printed on 32bit systems */
187 	BTRFS_FS_32BIT_ERROR,
188 	BTRFS_FS_32BIT_WARN,
189 #endif
190 };
191 
192 /*
193  * Flags for mount options.
194  *
195  * Note: don't forget to add new options to btrfs_show_options()
196  */
197 enum {
198 	BTRFS_MOUNT_NODATASUM			= (1ULL << 0),
199 	BTRFS_MOUNT_NODATACOW			= (1ULL << 1),
200 	BTRFS_MOUNT_NOBARRIER			= (1ULL << 2),
201 	BTRFS_MOUNT_SSD				= (1ULL << 3),
202 	BTRFS_MOUNT_DEGRADED			= (1ULL << 4),
203 	BTRFS_MOUNT_COMPRESS			= (1ULL << 5),
204 	BTRFS_MOUNT_NOTREELOG			= (1ULL << 6),
205 	BTRFS_MOUNT_FLUSHONCOMMIT		= (1ULL << 7),
206 	BTRFS_MOUNT_SSD_SPREAD			= (1ULL << 8),
207 	BTRFS_MOUNT_NOSSD			= (1ULL << 9),
208 	BTRFS_MOUNT_DISCARD_SYNC		= (1ULL << 10),
209 	BTRFS_MOUNT_FORCE_COMPRESS		= (1ULL << 11),
210 	BTRFS_MOUNT_SPACE_CACHE			= (1ULL << 12),
211 	BTRFS_MOUNT_CLEAR_CACHE			= (1ULL << 13),
212 	BTRFS_MOUNT_USER_SUBVOL_RM_ALLOWED	= (1ULL << 14),
213 	BTRFS_MOUNT_ENOSPC_DEBUG		= (1ULL << 15),
214 	BTRFS_MOUNT_AUTO_DEFRAG			= (1ULL << 16),
215 	BTRFS_MOUNT_USEBACKUPROOT		= (1ULL << 17),
216 	BTRFS_MOUNT_SKIP_BALANCE		= (1ULL << 18),
217 	BTRFS_MOUNT_PANIC_ON_FATAL_ERROR	= (1ULL << 19),
218 	BTRFS_MOUNT_RESCAN_UUID_TREE		= (1ULL << 20),
219 	BTRFS_MOUNT_FRAGMENT_DATA		= (1ULL << 21),
220 	BTRFS_MOUNT_FRAGMENT_METADATA		= (1ULL << 22),
221 	BTRFS_MOUNT_FREE_SPACE_TREE		= (1ULL << 23),
222 	BTRFS_MOUNT_NOLOGREPLAY			= (1ULL << 24),
223 	BTRFS_MOUNT_REF_VERIFY			= (1ULL << 25),
224 	BTRFS_MOUNT_DISCARD_ASYNC		= (1ULL << 26),
225 	BTRFS_MOUNT_IGNOREBADROOTS		= (1ULL << 27),
226 	BTRFS_MOUNT_IGNOREDATACSUMS		= (1ULL << 28),
227 	BTRFS_MOUNT_NODISCARD			= (1ULL << 29),
228 	BTRFS_MOUNT_NOSPACECACHE		= (1ULL << 30),
229 	BTRFS_MOUNT_IGNOREMETACSUMS		= (1ULL << 31),
230 	BTRFS_MOUNT_IGNORESUPERFLAGS		= (1ULL << 32),
231 };
232 
233 /*
234  * Compat flags that we support.  If any incompat flags are set other than the
235  * ones specified below then we will fail to mount
236  */
237 #define BTRFS_FEATURE_COMPAT_SUPP		0ULL
238 #define BTRFS_FEATURE_COMPAT_SAFE_SET		0ULL
239 #define BTRFS_FEATURE_COMPAT_SAFE_CLEAR		0ULL
240 
241 #define BTRFS_FEATURE_COMPAT_RO_SUPP			\
242 	(BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE |	\
243 	 BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID | \
244 	 BTRFS_FEATURE_COMPAT_RO_VERITY |		\
245 	 BTRFS_FEATURE_COMPAT_RO_BLOCK_GROUP_TREE)
246 
247 #define BTRFS_FEATURE_COMPAT_RO_SAFE_SET	0ULL
248 #define BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR	0ULL
249 
250 #define BTRFS_FEATURE_INCOMPAT_SUPP_STABLE		\
251 	(BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF |		\
252 	 BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL |	\
253 	 BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS |		\
254 	 BTRFS_FEATURE_INCOMPAT_BIG_METADATA |		\
255 	 BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO |		\
256 	 BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD |		\
257 	 BTRFS_FEATURE_INCOMPAT_RAID56 |		\
258 	 BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF |		\
259 	 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA |	\
260 	 BTRFS_FEATURE_INCOMPAT_NO_HOLES	|	\
261 	 BTRFS_FEATURE_INCOMPAT_METADATA_UUID	|	\
262 	 BTRFS_FEATURE_INCOMPAT_RAID1C34	|	\
263 	 BTRFS_FEATURE_INCOMPAT_ZONED		|	\
264 	 BTRFS_FEATURE_INCOMPAT_SIMPLE_QUOTA)
265 
266 #ifdef CONFIG_BTRFS_DEBUG
267 	/*
268 	 * Features under developmen like Extent tree v2 support is enabled
269 	 * only under CONFIG_BTRFS_DEBUG.
270 	 */
271 #define BTRFS_FEATURE_INCOMPAT_SUPP		\
272 	(BTRFS_FEATURE_INCOMPAT_SUPP_STABLE |	\
273 	 BTRFS_FEATURE_INCOMPAT_RAID_STRIPE_TREE | \
274 	 BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2)
275 
276 #else
277 
278 #define BTRFS_FEATURE_INCOMPAT_SUPP		\
279 	(BTRFS_FEATURE_INCOMPAT_SUPP_STABLE)
280 
281 #endif
282 
283 #define BTRFS_FEATURE_INCOMPAT_SAFE_SET			\
284 	(BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
285 #define BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR		0ULL
286 
287 #define BTRFS_DEFAULT_COMMIT_INTERVAL	(30)
288 #define BTRFS_DEFAULT_MAX_INLINE	(2048)
289 
290 struct btrfs_dev_replace {
291 	/* See #define above */
292 	u64 replace_state;
293 	/* Seconds since 1-Jan-1970 */
294 	time64_t time_started;
295 	/* Seconds since 1-Jan-1970 */
296 	time64_t time_stopped;
297 	atomic64_t num_write_errors;
298 	atomic64_t num_uncorrectable_read_errors;
299 
300 	u64 cursor_left;
301 	u64 committed_cursor_left;
302 	u64 cursor_left_last_write_of_item;
303 	u64 cursor_right;
304 
305 	/* See #define above */
306 	u64 cont_reading_from_srcdev_mode;
307 
308 	int is_valid;
309 	int item_needs_writeback;
310 	struct btrfs_device *srcdev;
311 	struct btrfs_device *tgtdev;
312 
313 	struct mutex lock_finishing_cancel_unmount;
314 	struct rw_semaphore rwsem;
315 
316 	struct btrfs_scrub_progress scrub_progress;
317 
318 	struct percpu_counter bio_counter;
319 	wait_queue_head_t replace_wait;
320 };
321 
322 /*
323  * Free clusters are used to claim free space in relatively large chunks,
324  * allowing us to do less seeky writes. They are used for all metadata
325  * allocations. In ssd_spread mode they are also used for data allocations.
326  */
327 struct btrfs_free_cluster {
328 	spinlock_t lock;
329 	spinlock_t refill_lock;
330 	struct rb_root root;
331 
332 	/* Largest extent in this cluster */
333 	u64 max_size;
334 
335 	/* First extent starting offset */
336 	u64 window_start;
337 
338 	/* We did a full search and couldn't create a cluster */
339 	bool fragmented;
340 
341 	struct btrfs_block_group *block_group;
342 	/*
343 	 * When a cluster is allocated from a block group, we put the cluster
344 	 * onto a list in the block group so that it can be freed before the
345 	 * block group is freed.
346 	 */
347 	struct list_head block_group_list;
348 };
349 
350 /* Discard control. */
351 /*
352  * Async discard uses multiple lists to differentiate the discard filter
353  * parameters.  Index 0 is for completely free block groups where we need to
354  * ensure the entire block group is trimmed without being lossy.  Indices
355  * afterwards represent monotonically decreasing discard filter sizes to
356  * prioritize what should be discarded next.
357  */
358 #define BTRFS_NR_DISCARD_LISTS		3
359 #define BTRFS_DISCARD_INDEX_UNUSED	0
360 #define BTRFS_DISCARD_INDEX_START	1
361 
362 struct btrfs_discard_ctl {
363 	struct workqueue_struct *discard_workers;
364 	struct delayed_work work;
365 	spinlock_t lock;
366 	struct btrfs_block_group *block_group;
367 	struct list_head discard_list[BTRFS_NR_DISCARD_LISTS];
368 	u64 prev_discard;
369 	u64 prev_discard_time;
370 	atomic_t discardable_extents;
371 	atomic64_t discardable_bytes;
372 	u64 max_discard_size;
373 	u64 delay_ms;
374 	u32 iops_limit;
375 	u32 kbps_limit;
376 	u64 discard_extent_bytes;
377 	u64 discard_bitmap_bytes;
378 	atomic64_t discard_bytes_saved;
379 };
380 
381 /*
382  * Exclusive operations (device replace, resize, device add/remove, balance)
383  */
384 enum btrfs_exclusive_operation {
385 	BTRFS_EXCLOP_NONE,
386 	BTRFS_EXCLOP_BALANCE_PAUSED,
387 	BTRFS_EXCLOP_BALANCE,
388 	BTRFS_EXCLOP_DEV_ADD,
389 	BTRFS_EXCLOP_DEV_REMOVE,
390 	BTRFS_EXCLOP_DEV_REPLACE,
391 	BTRFS_EXCLOP_RESIZE,
392 	BTRFS_EXCLOP_SWAP_ACTIVATE,
393 };
394 
395 /* Store data about transaction commits, exported via sysfs. */
396 struct btrfs_commit_stats {
397 	/* Total number of commits */
398 	u64 commit_count;
399 	/* The maximum commit duration so far in ns */
400 	u64 max_commit_dur;
401 	/* The last commit duration in ns */
402 	u64 last_commit_dur;
403 	/* The total commit duration in ns */
404 	u64 total_commit_dur;
405 };
406 
407 struct btrfs_fs_info {
408 	u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
409 	unsigned long flags;
410 	struct btrfs_root *tree_root;
411 	struct btrfs_root *chunk_root;
412 	struct btrfs_root *dev_root;
413 	struct btrfs_root *fs_root;
414 	struct btrfs_root *quota_root;
415 	struct btrfs_root *uuid_root;
416 	struct btrfs_root *data_reloc_root;
417 	struct btrfs_root *block_group_root;
418 	struct btrfs_root *stripe_root;
419 
420 	/* The log root tree is a directory of all the other log roots */
421 	struct btrfs_root *log_root_tree;
422 
423 	/* The tree that holds the global roots (csum, extent, etc) */
424 	rwlock_t global_root_lock;
425 	struct rb_root global_root_tree;
426 
427 	spinlock_t fs_roots_radix_lock;
428 	struct radix_tree_root fs_roots_radix;
429 
430 	/* Block group cache stuff */
431 	rwlock_t block_group_cache_lock;
432 	struct rb_root_cached block_group_cache_tree;
433 
434 	/* Keep track of unallocated space */
435 	atomic64_t free_chunk_space;
436 
437 	/* Track ranges which are used by log trees blocks/logged data extents */
438 	struct extent_io_tree excluded_extents;
439 
440 	/* logical->physical extent mapping */
441 	struct rb_root_cached mapping_tree;
442 	rwlock_t mapping_tree_lock;
443 
444 	/*
445 	 * Block reservation for extent, checksum, root tree and delayed dir
446 	 * index item.
447 	 */
448 	struct btrfs_block_rsv global_block_rsv;
449 	/* Block reservation for metadata operations */
450 	struct btrfs_block_rsv trans_block_rsv;
451 	/* Block reservation for chunk tree */
452 	struct btrfs_block_rsv chunk_block_rsv;
453 	/* Block reservation for delayed operations */
454 	struct btrfs_block_rsv delayed_block_rsv;
455 	/* Block reservation for delayed refs */
456 	struct btrfs_block_rsv delayed_refs_rsv;
457 
458 	struct btrfs_block_rsv empty_block_rsv;
459 
460 	/*
461 	 * Updated while holding the lock 'trans_lock'. Due to the life cycle of
462 	 * a transaction, it can be directly read while holding a transaction
463 	 * handle, everywhere else must be read with btrfs_get_fs_generation().
464 	 * Should always be updated using btrfs_set_fs_generation().
465 	 */
466 	u64 generation;
467 	/*
468 	 * Always use btrfs_get_last_trans_committed() and
469 	 * btrfs_set_last_trans_committed() to read and update this field.
470 	 */
471 	u64 last_trans_committed;
472 	/*
473 	 * Generation of the last transaction used for block group relocation
474 	 * since the filesystem was last mounted (or 0 if none happened yet).
475 	 * Must be written and read while holding btrfs_fs_info::commit_root_sem.
476 	 */
477 	u64 last_reloc_trans;
478 
479 	/*
480 	 * This is updated to the current trans every time a full commit is
481 	 * required instead of the faster short fsync log commits
482 	 */
483 	u64 last_trans_log_full_commit;
484 	unsigned long long mount_opt;
485 
486 	unsigned long compress_type:4;
487 	unsigned int compress_level;
488 	u32 commit_interval;
489 	/*
490 	 * It is a suggestive number, the read side is safe even it gets a
491 	 * wrong number because we will write out the data into a regular
492 	 * extent. The write side(mount/remount) is under ->s_umount lock,
493 	 * so it is also safe.
494 	 */
495 	u64 max_inline;
496 
497 	struct btrfs_transaction *running_transaction;
498 	wait_queue_head_t transaction_throttle;
499 	wait_queue_head_t transaction_wait;
500 	wait_queue_head_t transaction_blocked_wait;
501 	wait_queue_head_t async_submit_wait;
502 
503 	/*
504 	 * Used to protect the incompat_flags, compat_flags, compat_ro_flags
505 	 * when they are updated.
506 	 *
507 	 * Because we do not clear the flags for ever, so we needn't use
508 	 * the lock on the read side.
509 	 *
510 	 * We also needn't use the lock when we mount the fs, because
511 	 * there is no other task which will update the flag.
512 	 */
513 	spinlock_t super_lock;
514 	struct btrfs_super_block *super_copy;
515 	struct btrfs_super_block *super_for_commit;
516 	struct super_block *sb;
517 	struct inode *btree_inode;
518 	struct mutex tree_log_mutex;
519 	struct mutex transaction_kthread_mutex;
520 	struct mutex cleaner_mutex;
521 	struct mutex chunk_mutex;
522 
523 	/*
524 	 * This is taken to make sure we don't set block groups ro after the
525 	 * free space cache has been allocated on them.
526 	 */
527 	struct mutex ro_block_group_mutex;
528 
529 	/*
530 	 * This is used during read/modify/write to make sure no two ios are
531 	 * trying to mod the same stripe at the same time.
532 	 */
533 	struct btrfs_stripe_hash_table *stripe_hash_table;
534 
535 	/*
536 	 * This protects the ordered operations list only while we are
537 	 * processing all of the entries on it.  This way we make sure the
538 	 * commit code doesn't find the list temporarily empty because another
539 	 * function happens to be doing non-waiting preflush before jumping
540 	 * into the main commit.
541 	 */
542 	struct mutex ordered_operations_mutex;
543 
544 	struct rw_semaphore commit_root_sem;
545 
546 	struct rw_semaphore cleanup_work_sem;
547 
548 	struct rw_semaphore subvol_sem;
549 
550 	spinlock_t trans_lock;
551 	/*
552 	 * The reloc mutex goes with the trans lock, it is taken during commit
553 	 * to protect us from the relocation code.
554 	 */
555 	struct mutex reloc_mutex;
556 
557 	struct list_head trans_list;
558 	struct list_head dead_roots;
559 	struct list_head caching_block_groups;
560 
561 	spinlock_t delayed_iput_lock;
562 	struct list_head delayed_iputs;
563 	atomic_t nr_delayed_iputs;
564 	wait_queue_head_t delayed_iputs_wait;
565 
566 	atomic64_t tree_mod_seq;
567 
568 	/* This protects tree_mod_log and tree_mod_seq_list */
569 	rwlock_t tree_mod_log_lock;
570 	struct rb_root tree_mod_log;
571 	struct list_head tree_mod_seq_list;
572 
573 	atomic_t async_delalloc_pages;
574 
575 	/* This is used to protect the following list -- ordered_roots. */
576 	spinlock_t ordered_root_lock;
577 
578 	/*
579 	 * All fs/file tree roots in which there are data=ordered extents
580 	 * pending writeback are added into this list.
581 	 *
582 	 * These can span multiple transactions and basically include every
583 	 * dirty data page that isn't from nodatacow.
584 	 */
585 	struct list_head ordered_roots;
586 
587 	struct mutex delalloc_root_mutex;
588 	spinlock_t delalloc_root_lock;
589 	/* All fs/file tree roots that have delalloc inodes. */
590 	struct list_head delalloc_roots;
591 
592 	/*
593 	 * There is a pool of worker threads for checksumming during writes and
594 	 * a pool for checksumming after reads.  This is because readers can
595 	 * run with FS locks held, and the writers may be waiting for those
596 	 * locks.  We don't want ordering in the pending list to cause
597 	 * deadlocks, and so the two are serviced separately.
598 	 *
599 	 * A third pool does submit_bio to avoid deadlocking with the other two.
600 	 */
601 	struct btrfs_workqueue *workers;
602 	struct btrfs_workqueue *delalloc_workers;
603 	struct btrfs_workqueue *flush_workers;
604 	struct workqueue_struct *endio_workers;
605 	struct workqueue_struct *endio_meta_workers;
606 	struct workqueue_struct *rmw_workers;
607 	struct workqueue_struct *compressed_write_workers;
608 	struct btrfs_workqueue *endio_write_workers;
609 	struct btrfs_workqueue *endio_freespace_worker;
610 	struct btrfs_workqueue *caching_workers;
611 
612 	/*
613 	 * Fixup workers take dirty pages that didn't properly go through the
614 	 * cow mechanism and make them safe to write.  It happens for the
615 	 * sys_munmap function call path.
616 	 */
617 	struct btrfs_workqueue *fixup_workers;
618 	struct btrfs_workqueue *delayed_workers;
619 
620 	struct task_struct *transaction_kthread;
621 	struct task_struct *cleaner_kthread;
622 	u32 thread_pool_size;
623 
624 	struct kobject *space_info_kobj;
625 	struct kobject *qgroups_kobj;
626 	struct kobject *discard_kobj;
627 
628 	/* Used to keep from writing metadata until there is a nice batch */
629 	struct percpu_counter dirty_metadata_bytes;
630 	struct percpu_counter delalloc_bytes;
631 	struct percpu_counter ordered_bytes;
632 	s32 dirty_metadata_batch;
633 	s32 delalloc_batch;
634 
635 	struct percpu_counter evictable_extent_maps;
636 	spinlock_t extent_map_shrinker_lock;
637 	u64 extent_map_shrinker_last_root;
638 	u64 extent_map_shrinker_last_ino;
639 
640 	/* Protected by 'trans_lock'. */
641 	struct list_head dirty_cowonly_roots;
642 
643 	struct btrfs_fs_devices *fs_devices;
644 
645 	/*
646 	 * The space_info list is effectively read only after initial setup.
647 	 * It is populated at mount time and cleaned up after all block groups
648 	 * are removed.  RCU is used to protect it.
649 	 */
650 	struct list_head space_info;
651 
652 	struct btrfs_space_info *data_sinfo;
653 
654 	struct reloc_control *reloc_ctl;
655 
656 	/* data_alloc_cluster is only used in ssd_spread mode */
657 	struct btrfs_free_cluster data_alloc_cluster;
658 
659 	/* All metadata allocations go through this cluster. */
660 	struct btrfs_free_cluster meta_alloc_cluster;
661 
662 	/* Auto defrag inodes go here. */
663 	spinlock_t defrag_inodes_lock;
664 	struct rb_root defrag_inodes;
665 	atomic_t defrag_running;
666 
667 	/* Used to protect avail_{data, metadata, system}_alloc_bits */
668 	seqlock_t profiles_lock;
669 	/*
670 	 * These three are in extended format (availability of single chunks is
671 	 * denoted by BTRFS_AVAIL_ALLOC_BIT_SINGLE bit, other types are denoted
672 	 * by corresponding BTRFS_BLOCK_GROUP_* bits)
673 	 */
674 	u64 avail_data_alloc_bits;
675 	u64 avail_metadata_alloc_bits;
676 	u64 avail_system_alloc_bits;
677 
678 	/* Balance state */
679 	spinlock_t balance_lock;
680 	struct mutex balance_mutex;
681 	atomic_t balance_pause_req;
682 	atomic_t balance_cancel_req;
683 	struct btrfs_balance_control *balance_ctl;
684 	wait_queue_head_t balance_wait_q;
685 
686 	/* Cancellation requests for chunk relocation */
687 	atomic_t reloc_cancel_req;
688 
689 	u32 data_chunk_allocations;
690 	u32 metadata_ratio;
691 
692 	void *bdev_holder;
693 
694 	/* Private scrub information */
695 	struct mutex scrub_lock;
696 	atomic_t scrubs_running;
697 	atomic_t scrub_pause_req;
698 	atomic_t scrubs_paused;
699 	atomic_t scrub_cancel_req;
700 	wait_queue_head_t scrub_pause_wait;
701 	/*
702 	 * The worker pointers are NULL iff the refcount is 0, ie. scrub is not
703 	 * running.
704 	 */
705 	refcount_t scrub_workers_refcnt;
706 	u32 sectors_per_page;
707 	struct workqueue_struct *scrub_workers;
708 
709 	struct btrfs_discard_ctl discard_ctl;
710 
711 	/* Is qgroup tracking in a consistent state? */
712 	u64 qgroup_flags;
713 
714 	/* Holds configuration and tracking. Protected by qgroup_lock. */
715 	struct rb_root qgroup_tree;
716 	spinlock_t qgroup_lock;
717 
718 	/*
719 	 * Used to avoid frequently calling ulist_alloc()/ulist_free()
720 	 * when doing qgroup accounting, it must be protected by qgroup_lock.
721 	 */
722 	struct ulist *qgroup_ulist;
723 
724 	/*
725 	 * Protect user change for quota operations. If a transaction is needed,
726 	 * it must be started before locking this lock.
727 	 */
728 	struct mutex qgroup_ioctl_lock;
729 
730 	/* List of dirty qgroups to be written at next commit. */
731 	struct list_head dirty_qgroups;
732 
733 	/* Used by qgroup for an efficient tree traversal. */
734 	u64 qgroup_seq;
735 
736 	/* Qgroup rescan items. */
737 	/* Protects the progress item */
738 	struct mutex qgroup_rescan_lock;
739 	struct btrfs_key qgroup_rescan_progress;
740 	struct btrfs_workqueue *qgroup_rescan_workers;
741 	struct completion qgroup_rescan_completion;
742 	struct btrfs_work qgroup_rescan_work;
743 	/* Protected by qgroup_rescan_lock */
744 	bool qgroup_rescan_running;
745 	u8 qgroup_drop_subtree_thres;
746 	u64 qgroup_enable_gen;
747 
748 	/*
749 	 * If this is not 0, then it indicates a serious filesystem error has
750 	 * happened and it contains that error (negative errno value).
751 	 */
752 	int fs_error;
753 
754 	/* Filesystem state */
755 	unsigned long fs_state;
756 
757 	struct btrfs_delayed_root *delayed_root;
758 
759 	/* Extent buffer radix tree */
760 	spinlock_t buffer_lock;
761 	/* Entries are eb->start / sectorsize */
762 	struct radix_tree_root buffer_radix;
763 
764 	/* Next backup root to be overwritten */
765 	int backup_root_index;
766 
767 	/* Device replace state */
768 	struct btrfs_dev_replace dev_replace;
769 
770 	struct semaphore uuid_tree_rescan_sem;
771 
772 	/* Used to reclaim the metadata space in the background. */
773 	struct work_struct async_reclaim_work;
774 	struct work_struct async_data_reclaim_work;
775 	struct work_struct preempt_reclaim_work;
776 
777 	/* Reclaim partially filled block groups in the background */
778 	struct work_struct reclaim_bgs_work;
779 	/* Protected by unused_bgs_lock. */
780 	struct list_head reclaim_bgs;
781 	int bg_reclaim_threshold;
782 
783 	/* Protects the lists unused_bgs and reclaim_bgs. */
784 	spinlock_t unused_bgs_lock;
785 	/* Protected by unused_bgs_lock. */
786 	struct list_head unused_bgs;
787 	struct mutex unused_bg_unpin_mutex;
788 	/* Protect block groups that are going to be deleted */
789 	struct mutex reclaim_bgs_lock;
790 
791 	/* Cached block sizes */
792 	u32 nodesize;
793 	u32 sectorsize;
794 	/* ilog2 of sectorsize, use to avoid 64bit division */
795 	u32 sectorsize_bits;
796 	u32 csum_size;
797 	u32 csums_per_leaf;
798 	u32 stripesize;
799 
800 	/*
801 	 * Maximum size of an extent. BTRFS_MAX_EXTENT_SIZE on regular
802 	 * filesystem, on zoned it depends on the device constraints.
803 	 */
804 	u64 max_extent_size;
805 
806 	/* Block groups and devices containing active swapfiles. */
807 	spinlock_t swapfile_pins_lock;
808 	struct rb_root swapfile_pins;
809 
810 	struct crypto_shash *csum_shash;
811 
812 	/* Type of exclusive operation running, protected by super_lock */
813 	enum btrfs_exclusive_operation exclusive_operation;
814 
815 	/*
816 	 * Zone size > 0 when in ZONED mode, otherwise it's used for a check
817 	 * if the mode is enabled
818 	 */
819 	u64 zone_size;
820 
821 	/* Constraints for ZONE_APPEND commands: */
822 	struct queue_limits limits;
823 	u64 max_zone_append_size;
824 
825 	struct mutex zoned_meta_io_lock;
826 	spinlock_t treelog_bg_lock;
827 	u64 treelog_bg;
828 
829 	/*
830 	 * Start of the dedicated data relocation block group, protected by
831 	 * relocation_bg_lock.
832 	 */
833 	spinlock_t relocation_bg_lock;
834 	u64 data_reloc_bg;
835 	struct mutex zoned_data_reloc_io_lock;
836 
837 	struct btrfs_block_group *active_meta_bg;
838 	struct btrfs_block_group *active_system_bg;
839 
840 	u64 nr_global_roots;
841 
842 	spinlock_t zone_active_bgs_lock;
843 	struct list_head zone_active_bgs;
844 
845 	/* Updates are not protected by any lock */
846 	struct btrfs_commit_stats commit_stats;
847 
848 	/*
849 	 * Last generation where we dropped a non-relocation root.
850 	 * Use btrfs_set_last_root_drop_gen() and btrfs_get_last_root_drop_gen()
851 	 * to change it and to read it, respectively.
852 	 */
853 	u64 last_root_drop_gen;
854 
855 	/*
856 	 * Annotations for transaction events (structures are empty when
857 	 * compiled without lockdep).
858 	 */
859 	struct lockdep_map btrfs_trans_num_writers_map;
860 	struct lockdep_map btrfs_trans_num_extwriters_map;
861 	struct lockdep_map btrfs_state_change_map[4];
862 	struct lockdep_map btrfs_trans_pending_ordered_map;
863 	struct lockdep_map btrfs_ordered_extent_map;
864 
865 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
866 	spinlock_t ref_verify_lock;
867 	struct rb_root block_tree;
868 #endif
869 
870 #ifdef CONFIG_BTRFS_DEBUG
871 	struct kobject *debug_kobj;
872 	struct list_head allocated_roots;
873 
874 	spinlock_t eb_leak_lock;
875 	struct list_head allocated_ebs;
876 #endif
877 };
878 
879 #define page_to_inode(_page)	(BTRFS_I(_Generic((_page),			\
880 					  struct page *: (_page))->mapping->host))
881 #define folio_to_inode(_folio)	(BTRFS_I(_Generic((_folio),			\
882 					  struct folio *: (_folio))->mapping->host))
883 
884 #define page_to_fs_info(_page)	 (page_to_inode(_page)->root->fs_info)
885 #define folio_to_fs_info(_folio) (folio_to_inode(_folio)->root->fs_info)
886 
887 #define inode_to_fs_info(_inode) (BTRFS_I(_Generic((_inode),			\
888 					   struct inode *: (_inode)))->root->fs_info)
889 
890 static inline u64 btrfs_get_fs_generation(const struct btrfs_fs_info *fs_info)
891 {
892 	return READ_ONCE(fs_info->generation);
893 }
894 
895 static inline void btrfs_set_fs_generation(struct btrfs_fs_info *fs_info, u64 gen)
896 {
897 	WRITE_ONCE(fs_info->generation, gen);
898 }
899 
900 static inline u64 btrfs_get_last_trans_committed(const struct btrfs_fs_info *fs_info)
901 {
902 	return READ_ONCE(fs_info->last_trans_committed);
903 }
904 
905 static inline void btrfs_set_last_trans_committed(struct btrfs_fs_info *fs_info, u64 gen)
906 {
907 	WRITE_ONCE(fs_info->last_trans_committed, gen);
908 }
909 
910 static inline void btrfs_set_last_root_drop_gen(struct btrfs_fs_info *fs_info,
911 						u64 gen)
912 {
913 	WRITE_ONCE(fs_info->last_root_drop_gen, gen);
914 }
915 
916 static inline u64 btrfs_get_last_root_drop_gen(const struct btrfs_fs_info *fs_info)
917 {
918 	return READ_ONCE(fs_info->last_root_drop_gen);
919 }
920 
921 /*
922  * Take the number of bytes to be checksummed and figure out how many leaves
923  * it would require to store the csums for that many bytes.
924  */
925 static inline u64 btrfs_csum_bytes_to_leaves(
926 			const struct btrfs_fs_info *fs_info, u64 csum_bytes)
927 {
928 	const u64 num_csums = csum_bytes >> fs_info->sectorsize_bits;
929 
930 	return DIV_ROUND_UP_ULL(num_csums, fs_info->csums_per_leaf);
931 }
932 
933 /*
934  * Use this if we would be adding new items, as we could split nodes as we cow
935  * down the tree.
936  */
937 static inline u64 btrfs_calc_insert_metadata_size(const struct btrfs_fs_info *fs_info,
938 						  unsigned num_items)
939 {
940 	return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * 2 * num_items;
941 }
942 
943 /*
944  * Doing a truncate or a modification won't result in new nodes or leaves, just
945  * what we need for COW.
946  */
947 static inline u64 btrfs_calc_metadata_size(const struct btrfs_fs_info *fs_info,
948 						 unsigned num_items)
949 {
950 	return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * num_items;
951 }
952 
953 #define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r->fs_info) >> 4) - \
954 					sizeof(struct btrfs_item))
955 
956 static inline bool btrfs_is_zoned(const struct btrfs_fs_info *fs_info)
957 {
958 	return IS_ENABLED(CONFIG_BLK_DEV_ZONED) && fs_info->zone_size > 0;
959 }
960 
961 /*
962  * Count how many fs_info->max_extent_size cover the @size
963  */
964 static inline u32 count_max_extents(const struct btrfs_fs_info *fs_info, u64 size)
965 {
966 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
967 	if (!fs_info)
968 		return div_u64(size + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE);
969 #endif
970 
971 	return div_u64(size + fs_info->max_extent_size - 1, fs_info->max_extent_size);
972 }
973 
974 bool btrfs_exclop_start(struct btrfs_fs_info *fs_info,
975 			enum btrfs_exclusive_operation type);
976 bool btrfs_exclop_start_try_lock(struct btrfs_fs_info *fs_info,
977 				 enum btrfs_exclusive_operation type);
978 void btrfs_exclop_start_unlock(struct btrfs_fs_info *fs_info);
979 void btrfs_exclop_finish(struct btrfs_fs_info *fs_info);
980 void btrfs_exclop_balance(struct btrfs_fs_info *fs_info,
981 			  enum btrfs_exclusive_operation op);
982 
983 int btrfs_check_ioctl_vol_args_path(const struct btrfs_ioctl_vol_args *vol_args);
984 
985 /* Compatibility and incompatibility defines */
986 void __btrfs_set_fs_incompat(struct btrfs_fs_info *fs_info, u64 flag,
987 			     const char *name);
988 void __btrfs_clear_fs_incompat(struct btrfs_fs_info *fs_info, u64 flag,
989 			       const char *name);
990 void __btrfs_set_fs_compat_ro(struct btrfs_fs_info *fs_info, u64 flag,
991 			      const char *name);
992 void __btrfs_clear_fs_compat_ro(struct btrfs_fs_info *fs_info, u64 flag,
993 				const char *name);
994 
995 #define __btrfs_fs_incompat(fs_info, flags)				\
996 	(!!(btrfs_super_incompat_flags((fs_info)->super_copy) & (flags)))
997 
998 #define __btrfs_fs_compat_ro(fs_info, flags)				\
999 	(!!(btrfs_super_compat_ro_flags((fs_info)->super_copy) & (flags)))
1000 
1001 #define btrfs_set_fs_incompat(__fs_info, opt)				\
1002 	__btrfs_set_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt, #opt)
1003 
1004 #define btrfs_clear_fs_incompat(__fs_info, opt)				\
1005 	__btrfs_clear_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt, #opt)
1006 
1007 #define btrfs_fs_incompat(fs_info, opt)					\
1008 	__btrfs_fs_incompat((fs_info), BTRFS_FEATURE_INCOMPAT_##opt)
1009 
1010 #define btrfs_set_fs_compat_ro(__fs_info, opt)				\
1011 	__btrfs_set_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt, #opt)
1012 
1013 #define btrfs_clear_fs_compat_ro(__fs_info, opt)			\
1014 	__btrfs_clear_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt, #opt)
1015 
1016 #define btrfs_fs_compat_ro(fs_info, opt)				\
1017 	__btrfs_fs_compat_ro((fs_info), BTRFS_FEATURE_COMPAT_RO_##opt)
1018 
1019 #define btrfs_clear_opt(o, opt)		((o) &= ~BTRFS_MOUNT_##opt)
1020 #define btrfs_set_opt(o, opt)		((o) |= BTRFS_MOUNT_##opt)
1021 #define btrfs_raw_test_opt(o, opt)	((o) & BTRFS_MOUNT_##opt)
1022 #define btrfs_test_opt(fs_info, opt)	((fs_info)->mount_opt & \
1023 					 BTRFS_MOUNT_##opt)
1024 
1025 static inline int btrfs_fs_closing(const struct btrfs_fs_info *fs_info)
1026 {
1027 	/* Do it this way so we only ever do one test_bit in the normal case. */
1028 	if (test_bit(BTRFS_FS_CLOSING_START, &fs_info->flags)) {
1029 		if (test_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags))
1030 			return 2;
1031 		return 1;
1032 	}
1033 	return 0;
1034 }
1035 
1036 /*
1037  * If we remount the fs to be R/O or umount the fs, the cleaner needn't do
1038  * anything except sleeping. This function is used to check the status of
1039  * the fs.
1040  * We check for BTRFS_FS_STATE_RO to avoid races with a concurrent remount,
1041  * since setting and checking for SB_RDONLY in the superblock's flags is not
1042  * atomic.
1043  */
1044 static inline int btrfs_need_cleaner_sleep(const struct btrfs_fs_info *fs_info)
1045 {
1046 	return test_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state) ||
1047 		btrfs_fs_closing(fs_info);
1048 }
1049 
1050 static inline void btrfs_wake_unfinished_drop(struct btrfs_fs_info *fs_info)
1051 {
1052 	clear_and_wake_up_bit(BTRFS_FS_UNFINISHED_DROPS, &fs_info->flags);
1053 }
1054 
1055 #define BTRFS_FS_ERROR(fs_info)	(READ_ONCE((fs_info)->fs_error))
1056 
1057 #define BTRFS_FS_LOG_CLEANUP_ERROR(fs_info)				\
1058 	(unlikely(test_bit(BTRFS_FS_STATE_LOG_CLEANUP_ERROR,		\
1059 			   &(fs_info)->fs_state)))
1060 
1061 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1062 
1063 #define EXPORT_FOR_TESTS
1064 
1065 static inline int btrfs_is_testing(const struct btrfs_fs_info *fs_info)
1066 {
1067 	return test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
1068 }
1069 
1070 void btrfs_test_destroy_inode(struct inode *inode);
1071 
1072 #else
1073 
1074 #define EXPORT_FOR_TESTS static
1075 
1076 static inline int btrfs_is_testing(const struct btrfs_fs_info *fs_info)
1077 {
1078 	return 0;
1079 }
1080 #endif
1081 
1082 #endif
1083