xref: /linux/fs/btrfs/fs.h (revision f5c31bcf604db54470868f3118a60dc4a9ba8813)
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/blkdev.h>
13 #include <linux/percpu_counter.h>
14 #include <linux/completion.h>
15 #include <linux/lockdep.h>
16 #include <linux/spinlock.h>
17 #include <linux/mutex.h>
18 #include <linux/rwlock_types.h>
19 #include <linux/rwsem.h>
20 #include <linux/semaphore.h>
21 #include <linux/list.h>
22 #include <linux/radix-tree.h>
23 #include <linux/workqueue.h>
24 #include <linux/wait.h>
25 #include <linux/wait_bit.h>
26 #include <linux/sched.h>
27 #include <linux/rbtree.h>
28 #include <uapi/linux/btrfs.h>
29 #include <uapi/linux/btrfs_tree.h>
30 #include "extent-io-tree.h"
31 #include "async-thread.h"
32 #include "block-rsv.h"
33 #include "fs.h"
34 
35 struct inode;
36 struct super_block;
37 struct kobject;
38 struct reloc_control;
39 struct crypto_shash;
40 struct ulist;
41 struct btrfs_device;
42 struct btrfs_block_group;
43 struct btrfs_root;
44 struct btrfs_fs_devices;
45 struct btrfs_transaction;
46 struct btrfs_delayed_root;
47 struct btrfs_balance_control;
48 struct btrfs_subpage_info;
49 struct btrfs_stripe_hash_table;
50 struct btrfs_space_info;
51 
52 #define BTRFS_MAX_EXTENT_SIZE SZ_128M
53 
54 #define BTRFS_OLDEST_GENERATION	0ULL
55 
56 #define BTRFS_EMPTY_DIR_SIZE 0
57 
58 #define BTRFS_DIRTY_METADATA_THRESH		SZ_32M
59 
60 #define BTRFS_SUPER_INFO_OFFSET			SZ_64K
61 #define BTRFS_SUPER_INFO_SIZE			4096
62 static_assert(sizeof(struct btrfs_super_block) == BTRFS_SUPER_INFO_SIZE);
63 
64 /*
65  * Number of metadata items necessary for an unlink operation:
66  *
67  * 1 for the possible orphan item
68  * 1 for the dir item
69  * 1 for the dir index
70  * 1 for the inode ref
71  * 1 for the inode
72  * 1 for the parent inode
73  */
74 #define BTRFS_UNLINK_METADATA_UNITS		6
75 
76 /*
77  * The reserved space at the beginning of each device.  It covers the primary
78  * super block and leaves space for potential use by other tools like
79  * bootloaders or to lower potential damage of accidental overwrite.
80  */
81 #define BTRFS_DEVICE_RANGE_RESERVED			(SZ_1M)
82 /*
83  * Runtime (in-memory) states of filesystem
84  */
85 enum {
86 	/*
87 	 * Filesystem is being remounted, allow to skip some operations, like
88 	 * defrag
89 	 */
90 	BTRFS_FS_STATE_REMOUNTING,
91 	/* Filesystem in RO mode */
92 	BTRFS_FS_STATE_RO,
93 	/* Track if a transaction abort has been reported on this filesystem */
94 	BTRFS_FS_STATE_TRANS_ABORTED,
95 	/*
96 	 * Bio operations should be blocked on this filesystem because a source
97 	 * or target device is being destroyed as part of a device replace
98 	 */
99 	BTRFS_FS_STATE_DEV_REPLACING,
100 	/* The btrfs_fs_info created for self-tests */
101 	BTRFS_FS_STATE_DUMMY_FS_INFO,
102 
103 	BTRFS_FS_STATE_NO_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			= (1UL << 0),
199 	BTRFS_MOUNT_NODATACOW			= (1UL << 1),
200 	BTRFS_MOUNT_NOBARRIER			= (1UL << 2),
201 	BTRFS_MOUNT_SSD				= (1UL << 3),
202 	BTRFS_MOUNT_DEGRADED			= (1UL << 4),
203 	BTRFS_MOUNT_COMPRESS			= (1UL << 5),
204 	BTRFS_MOUNT_NOTREELOG   		= (1UL << 6),
205 	BTRFS_MOUNT_FLUSHONCOMMIT		= (1UL << 7),
206 	BTRFS_MOUNT_SSD_SPREAD			= (1UL << 8),
207 	BTRFS_MOUNT_NOSSD			= (1UL << 9),
208 	BTRFS_MOUNT_DISCARD_SYNC		= (1UL << 10),
209 	BTRFS_MOUNT_FORCE_COMPRESS      	= (1UL << 11),
210 	BTRFS_MOUNT_SPACE_CACHE			= (1UL << 12),
211 	BTRFS_MOUNT_CLEAR_CACHE			= (1UL << 13),
212 	BTRFS_MOUNT_USER_SUBVOL_RM_ALLOWED	= (1UL << 14),
213 	BTRFS_MOUNT_ENOSPC_DEBUG		= (1UL << 15),
214 	BTRFS_MOUNT_AUTO_DEFRAG			= (1UL << 16),
215 	BTRFS_MOUNT_USEBACKUPROOT		= (1UL << 17),
216 	BTRFS_MOUNT_SKIP_BALANCE		= (1UL << 18),
217 	BTRFS_MOUNT_PANIC_ON_FATAL_ERROR	= (1UL << 19),
218 	BTRFS_MOUNT_RESCAN_UUID_TREE		= (1UL << 20),
219 	BTRFS_MOUNT_FRAGMENT_DATA		= (1UL << 21),
220 	BTRFS_MOUNT_FRAGMENT_METADATA		= (1UL << 22),
221 	BTRFS_MOUNT_FREE_SPACE_TREE		= (1UL << 23),
222 	BTRFS_MOUNT_NOLOGREPLAY			= (1UL << 24),
223 	BTRFS_MOUNT_REF_VERIFY			= (1UL << 25),
224 	BTRFS_MOUNT_DISCARD_ASYNC		= (1UL << 26),
225 	BTRFS_MOUNT_IGNOREBADROOTS		= (1UL << 27),
226 	BTRFS_MOUNT_IGNOREDATACSUMS		= (1UL << 28),
227 	BTRFS_MOUNT_NODISCARD			= (1UL << 29),
228 	BTRFS_MOUNT_NOSPACECACHE		= (1UL << 30),
229 };
230 
231 /*
232  * Compat flags that we support.  If any incompat flags are set other than the
233  * ones specified below then we will fail to mount
234  */
235 #define BTRFS_FEATURE_COMPAT_SUPP		0ULL
236 #define BTRFS_FEATURE_COMPAT_SAFE_SET		0ULL
237 #define BTRFS_FEATURE_COMPAT_SAFE_CLEAR		0ULL
238 
239 #define BTRFS_FEATURE_COMPAT_RO_SUPP			\
240 	(BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE |	\
241 	 BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID | \
242 	 BTRFS_FEATURE_COMPAT_RO_VERITY |		\
243 	 BTRFS_FEATURE_COMPAT_RO_BLOCK_GROUP_TREE)
244 
245 #define BTRFS_FEATURE_COMPAT_RO_SAFE_SET	0ULL
246 #define BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR	0ULL
247 
248 #define BTRFS_FEATURE_INCOMPAT_SUPP_STABLE		\
249 	(BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF |		\
250 	 BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL |	\
251 	 BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS |		\
252 	 BTRFS_FEATURE_INCOMPAT_BIG_METADATA |		\
253 	 BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO |		\
254 	 BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD |		\
255 	 BTRFS_FEATURE_INCOMPAT_RAID56 |		\
256 	 BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF |		\
257 	 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA |	\
258 	 BTRFS_FEATURE_INCOMPAT_NO_HOLES	|	\
259 	 BTRFS_FEATURE_INCOMPAT_METADATA_UUID	|	\
260 	 BTRFS_FEATURE_INCOMPAT_RAID1C34	|	\
261 	 BTRFS_FEATURE_INCOMPAT_ZONED		|	\
262 	 BTRFS_FEATURE_INCOMPAT_SIMPLE_QUOTA)
263 
264 #ifdef CONFIG_BTRFS_DEBUG
265 	/*
266 	 * Features under developmen like Extent tree v2 support is enabled
267 	 * only under CONFIG_BTRFS_DEBUG.
268 	 */
269 #define BTRFS_FEATURE_INCOMPAT_SUPP		\
270 	(BTRFS_FEATURE_INCOMPAT_SUPP_STABLE |	\
271 	 BTRFS_FEATURE_INCOMPAT_RAID_STRIPE_TREE | \
272 	 BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2)
273 
274 #else
275 
276 #define BTRFS_FEATURE_INCOMPAT_SUPP		\
277 	(BTRFS_FEATURE_INCOMPAT_SUPP_STABLE)
278 
279 #endif
280 
281 #define BTRFS_FEATURE_INCOMPAT_SAFE_SET			\
282 	(BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
283 #define BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR		0ULL
284 
285 #define BTRFS_DEFAULT_COMMIT_INTERVAL	(30)
286 #define BTRFS_DEFAULT_MAX_INLINE	(2048)
287 
288 struct btrfs_dev_replace {
289 	/* See #define above */
290 	u64 replace_state;
291 	/* Seconds since 1-Jan-1970 */
292 	time64_t time_started;
293 	/* Seconds since 1-Jan-1970 */
294 	time64_t time_stopped;
295 	atomic64_t num_write_errors;
296 	atomic64_t num_uncorrectable_read_errors;
297 
298 	u64 cursor_left;
299 	u64 committed_cursor_left;
300 	u64 cursor_left_last_write_of_item;
301 	u64 cursor_right;
302 
303 	/* See #define above */
304 	u64 cont_reading_from_srcdev_mode;
305 
306 	int is_valid;
307 	int item_needs_writeback;
308 	struct btrfs_device *srcdev;
309 	struct btrfs_device *tgtdev;
310 
311 	struct mutex lock_finishing_cancel_unmount;
312 	struct rw_semaphore rwsem;
313 
314 	struct btrfs_scrub_progress scrub_progress;
315 
316 	struct percpu_counter bio_counter;
317 	wait_queue_head_t replace_wait;
318 };
319 
320 /*
321  * Free clusters are used to claim free space in relatively large chunks,
322  * allowing us to do less seeky writes. They are used for all metadata
323  * allocations. In ssd_spread mode they are also used for data allocations.
324  */
325 struct btrfs_free_cluster {
326 	spinlock_t lock;
327 	spinlock_t refill_lock;
328 	struct rb_root root;
329 
330 	/* Largest extent in this cluster */
331 	u64 max_size;
332 
333 	/* First extent starting offset */
334 	u64 window_start;
335 
336 	/* We did a full search and couldn't create a cluster */
337 	bool fragmented;
338 
339 	struct btrfs_block_group *block_group;
340 	/*
341 	 * When a cluster is allocated from a block group, we put the cluster
342 	 * onto a list in the block group so that it can be freed before the
343 	 * block group is freed.
344 	 */
345 	struct list_head block_group_list;
346 };
347 
348 /* Discard control. */
349 /*
350  * Async discard uses multiple lists to differentiate the discard filter
351  * parameters.  Index 0 is for completely free block groups where we need to
352  * ensure the entire block group is trimmed without being lossy.  Indices
353  * afterwards represent monotonically decreasing discard filter sizes to
354  * prioritize what should be discarded next.
355  */
356 #define BTRFS_NR_DISCARD_LISTS		3
357 #define BTRFS_DISCARD_INDEX_UNUSED	0
358 #define BTRFS_DISCARD_INDEX_START	1
359 
360 struct btrfs_discard_ctl {
361 	struct workqueue_struct *discard_workers;
362 	struct delayed_work work;
363 	spinlock_t lock;
364 	struct btrfs_block_group *block_group;
365 	struct list_head discard_list[BTRFS_NR_DISCARD_LISTS];
366 	u64 prev_discard;
367 	u64 prev_discard_time;
368 	atomic_t discardable_extents;
369 	atomic64_t discardable_bytes;
370 	u64 max_discard_size;
371 	u64 delay_ms;
372 	u32 iops_limit;
373 	u32 kbps_limit;
374 	u64 discard_extent_bytes;
375 	u64 discard_bitmap_bytes;
376 	atomic64_t discard_bytes_saved;
377 };
378 
379 /*
380  * Exclusive operations (device replace, resize, device add/remove, balance)
381  */
382 enum btrfs_exclusive_operation {
383 	BTRFS_EXCLOP_NONE,
384 	BTRFS_EXCLOP_BALANCE_PAUSED,
385 	BTRFS_EXCLOP_BALANCE,
386 	BTRFS_EXCLOP_DEV_ADD,
387 	BTRFS_EXCLOP_DEV_REMOVE,
388 	BTRFS_EXCLOP_DEV_REPLACE,
389 	BTRFS_EXCLOP_RESIZE,
390 	BTRFS_EXCLOP_SWAP_ACTIVATE,
391 };
392 
393 /* Store data about transaction commits, exported via sysfs. */
394 struct btrfs_commit_stats {
395 	/* Total number of commits */
396 	u64 commit_count;
397 	/* The maximum commit duration so far in ns */
398 	u64 max_commit_dur;
399 	/* The last commit duration in ns */
400 	u64 last_commit_dur;
401 	/* The total commit duration in ns */
402 	u64 total_commit_dur;
403 };
404 
405 struct btrfs_fs_info {
406 	u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
407 	unsigned long flags;
408 	struct btrfs_root *tree_root;
409 	struct btrfs_root *chunk_root;
410 	struct btrfs_root *dev_root;
411 	struct btrfs_root *fs_root;
412 	struct btrfs_root *quota_root;
413 	struct btrfs_root *uuid_root;
414 	struct btrfs_root *data_reloc_root;
415 	struct btrfs_root *block_group_root;
416 	struct btrfs_root *stripe_root;
417 
418 	/* The log root tree is a directory of all the other log roots */
419 	struct btrfs_root *log_root_tree;
420 
421 	/* The tree that holds the global roots (csum, extent, etc) */
422 	rwlock_t global_root_lock;
423 	struct rb_root global_root_tree;
424 
425 	spinlock_t fs_roots_radix_lock;
426 	struct radix_tree_root fs_roots_radix;
427 
428 	/* Block group cache stuff */
429 	rwlock_t block_group_cache_lock;
430 	struct rb_root_cached block_group_cache_tree;
431 
432 	/* Keep track of unallocated space */
433 	atomic64_t free_chunk_space;
434 
435 	/* Track ranges which are used by log trees blocks/logged data extents */
436 	struct extent_io_tree excluded_extents;
437 
438 	/* logical->physical extent mapping */
439 	struct rb_root_cached mapping_tree;
440 	rwlock_t mapping_tree_lock;
441 
442 	/*
443 	 * Block reservation for extent, checksum, root tree and delayed dir
444 	 * index item.
445 	 */
446 	struct btrfs_block_rsv global_block_rsv;
447 	/* Block reservation for metadata operations */
448 	struct btrfs_block_rsv trans_block_rsv;
449 	/* Block reservation for chunk tree */
450 	struct btrfs_block_rsv chunk_block_rsv;
451 	/* Block reservation for delayed operations */
452 	struct btrfs_block_rsv delayed_block_rsv;
453 	/* Block reservation for delayed refs */
454 	struct btrfs_block_rsv delayed_refs_rsv;
455 
456 	struct btrfs_block_rsv empty_block_rsv;
457 
458 	/*
459 	 * Updated while holding the lock 'trans_lock'. Due to the life cycle of
460 	 * a transaction, it can be directly read while holding a transaction
461 	 * handle, everywhere else must be read with btrfs_get_fs_generation().
462 	 * Should always be updated using btrfs_set_fs_generation().
463 	 */
464 	u64 generation;
465 	/*
466 	 * Always use btrfs_get_last_trans_committed() and
467 	 * btrfs_set_last_trans_committed() to read and update this field.
468 	 */
469 	u64 last_trans_committed;
470 	/*
471 	 * Generation of the last transaction used for block group relocation
472 	 * since the filesystem was last mounted (or 0 if none happened yet).
473 	 * Must be written and read while holding btrfs_fs_info::commit_root_sem.
474 	 */
475 	u64 last_reloc_trans;
476 
477 	/*
478 	 * This is updated to the current trans every time a full commit is
479 	 * required instead of the faster short fsync log commits
480 	 */
481 	u64 last_trans_log_full_commit;
482 	unsigned long mount_opt;
483 
484 	unsigned long compress_type:4;
485 	unsigned int compress_level;
486 	u32 commit_interval;
487 	/*
488 	 * It is a suggestive number, the read side is safe even it gets a
489 	 * wrong number because we will write out the data into a regular
490 	 * extent. The write side(mount/remount) is under ->s_umount lock,
491 	 * so it is also safe.
492 	 */
493 	u64 max_inline;
494 
495 	struct btrfs_transaction *running_transaction;
496 	wait_queue_head_t transaction_throttle;
497 	wait_queue_head_t transaction_wait;
498 	wait_queue_head_t transaction_blocked_wait;
499 	wait_queue_head_t async_submit_wait;
500 
501 	/*
502 	 * Used to protect the incompat_flags, compat_flags, compat_ro_flags
503 	 * when they are updated.
504 	 *
505 	 * Because we do not clear the flags for ever, so we needn't use
506 	 * the lock on the read side.
507 	 *
508 	 * We also needn't use the lock when we mount the fs, because
509 	 * there is no other task which will update the flag.
510 	 */
511 	spinlock_t super_lock;
512 	struct btrfs_super_block *super_copy;
513 	struct btrfs_super_block *super_for_commit;
514 	struct super_block *sb;
515 	struct inode *btree_inode;
516 	struct mutex tree_log_mutex;
517 	struct mutex transaction_kthread_mutex;
518 	struct mutex cleaner_mutex;
519 	struct mutex chunk_mutex;
520 
521 	/*
522 	 * This is taken to make sure we don't set block groups ro after the
523 	 * free space cache has been allocated on them.
524 	 */
525 	struct mutex ro_block_group_mutex;
526 
527 	/*
528 	 * This is used during read/modify/write to make sure no two ios are
529 	 * trying to mod the same stripe at the same time.
530 	 */
531 	struct btrfs_stripe_hash_table *stripe_hash_table;
532 
533 	/*
534 	 * This protects the ordered operations list only while we are
535 	 * processing all of the entries on it.  This way we make sure the
536 	 * commit code doesn't find the list temporarily empty because another
537 	 * function happens to be doing non-waiting preflush before jumping
538 	 * into the main commit.
539 	 */
540 	struct mutex ordered_operations_mutex;
541 
542 	struct rw_semaphore commit_root_sem;
543 
544 	struct rw_semaphore cleanup_work_sem;
545 
546 	struct rw_semaphore subvol_sem;
547 
548 	spinlock_t trans_lock;
549 	/*
550 	 * The reloc mutex goes with the trans lock, it is taken during commit
551 	 * to protect us from the relocation code.
552 	 */
553 	struct mutex reloc_mutex;
554 
555 	struct list_head trans_list;
556 	struct list_head dead_roots;
557 	struct list_head caching_block_groups;
558 
559 	spinlock_t delayed_iput_lock;
560 	struct list_head delayed_iputs;
561 	atomic_t nr_delayed_iputs;
562 	wait_queue_head_t delayed_iputs_wait;
563 
564 	atomic64_t tree_mod_seq;
565 
566 	/* This protects tree_mod_log and tree_mod_seq_list */
567 	rwlock_t tree_mod_log_lock;
568 	struct rb_root tree_mod_log;
569 	struct list_head tree_mod_seq_list;
570 
571 	atomic_t async_delalloc_pages;
572 
573 	/* This is used to protect the following list -- ordered_roots. */
574 	spinlock_t ordered_root_lock;
575 
576 	/*
577 	 * All fs/file tree roots in which there are data=ordered extents
578 	 * pending writeback are added into this list.
579 	 *
580 	 * These can span multiple transactions and basically include every
581 	 * dirty data page that isn't from nodatacow.
582 	 */
583 	struct list_head ordered_roots;
584 
585 	struct mutex delalloc_root_mutex;
586 	spinlock_t delalloc_root_lock;
587 	/* All fs/file tree roots that have delalloc inodes. */
588 	struct list_head delalloc_roots;
589 
590 	/*
591 	 * There is a pool of worker threads for checksumming during writes and
592 	 * a pool for checksumming after reads.  This is because readers can
593 	 * run with FS locks held, and the writers may be waiting for those
594 	 * locks.  We don't want ordering in the pending list to cause
595 	 * deadlocks, and so the two are serviced separately.
596 	 *
597 	 * A third pool does submit_bio to avoid deadlocking with the other two.
598 	 */
599 	struct btrfs_workqueue *workers;
600 	struct btrfs_workqueue *delalloc_workers;
601 	struct btrfs_workqueue *flush_workers;
602 	struct workqueue_struct *endio_workers;
603 	struct workqueue_struct *endio_meta_workers;
604 	struct workqueue_struct *rmw_workers;
605 	struct workqueue_struct *compressed_write_workers;
606 	struct btrfs_workqueue *endio_write_workers;
607 	struct btrfs_workqueue *endio_freespace_worker;
608 	struct btrfs_workqueue *caching_workers;
609 
610 	/*
611 	 * Fixup workers take dirty pages that didn't properly go through the
612 	 * cow mechanism and make them safe to write.  It happens for the
613 	 * sys_munmap function call path.
614 	 */
615 	struct btrfs_workqueue *fixup_workers;
616 	struct btrfs_workqueue *delayed_workers;
617 
618 	struct task_struct *transaction_kthread;
619 	struct task_struct *cleaner_kthread;
620 	u32 thread_pool_size;
621 
622 	struct kobject *space_info_kobj;
623 	struct kobject *qgroups_kobj;
624 	struct kobject *discard_kobj;
625 
626 	/* Used to keep from writing metadata until there is a nice batch */
627 	struct percpu_counter dirty_metadata_bytes;
628 	struct percpu_counter delalloc_bytes;
629 	struct percpu_counter ordered_bytes;
630 	s32 dirty_metadata_batch;
631 	s32 delalloc_batch;
632 
633 	/* Protected by 'trans_lock'. */
634 	struct list_head dirty_cowonly_roots;
635 
636 	struct btrfs_fs_devices *fs_devices;
637 
638 	/*
639 	 * The space_info list is effectively read only after initial setup.
640 	 * It is populated at mount time and cleaned up after all block groups
641 	 * are removed.  RCU is used to protect it.
642 	 */
643 	struct list_head space_info;
644 
645 	struct btrfs_space_info *data_sinfo;
646 
647 	struct reloc_control *reloc_ctl;
648 
649 	/* data_alloc_cluster is only used in ssd_spread mode */
650 	struct btrfs_free_cluster data_alloc_cluster;
651 
652 	/* All metadata allocations go through this cluster. */
653 	struct btrfs_free_cluster meta_alloc_cluster;
654 
655 	/* Auto defrag inodes go here. */
656 	spinlock_t defrag_inodes_lock;
657 	struct rb_root defrag_inodes;
658 	atomic_t defrag_running;
659 
660 	/* Used to protect avail_{data, metadata, system}_alloc_bits */
661 	seqlock_t profiles_lock;
662 	/*
663 	 * These three are in extended format (availability of single chunks is
664 	 * denoted by BTRFS_AVAIL_ALLOC_BIT_SINGLE bit, other types are denoted
665 	 * by corresponding BTRFS_BLOCK_GROUP_* bits)
666 	 */
667 	u64 avail_data_alloc_bits;
668 	u64 avail_metadata_alloc_bits;
669 	u64 avail_system_alloc_bits;
670 
671 	/* Balance state */
672 	spinlock_t balance_lock;
673 	struct mutex balance_mutex;
674 	atomic_t balance_pause_req;
675 	atomic_t balance_cancel_req;
676 	struct btrfs_balance_control *balance_ctl;
677 	wait_queue_head_t balance_wait_q;
678 
679 	/* Cancellation requests for chunk relocation */
680 	atomic_t reloc_cancel_req;
681 
682 	u32 data_chunk_allocations;
683 	u32 metadata_ratio;
684 
685 	void *bdev_holder;
686 
687 	/* Private scrub information */
688 	struct mutex scrub_lock;
689 	atomic_t scrubs_running;
690 	atomic_t scrub_pause_req;
691 	atomic_t scrubs_paused;
692 	atomic_t scrub_cancel_req;
693 	wait_queue_head_t scrub_pause_wait;
694 	/*
695 	 * The worker pointers are NULL iff the refcount is 0, ie. scrub is not
696 	 * running.
697 	 */
698 	refcount_t scrub_workers_refcnt;
699 	struct workqueue_struct *scrub_workers;
700 	struct btrfs_subpage_info *subpage_info;
701 
702 	struct btrfs_discard_ctl discard_ctl;
703 
704 	/* Is qgroup tracking in a consistent state? */
705 	u64 qgroup_flags;
706 
707 	/* Holds configuration and tracking. Protected by qgroup_lock. */
708 	struct rb_root qgroup_tree;
709 	spinlock_t qgroup_lock;
710 
711 	/*
712 	 * Used to avoid frequently calling ulist_alloc()/ulist_free()
713 	 * when doing qgroup accounting, it must be protected by qgroup_lock.
714 	 */
715 	struct ulist *qgroup_ulist;
716 
717 	/*
718 	 * Protect user change for quota operations. If a transaction is needed,
719 	 * it must be started before locking this lock.
720 	 */
721 	struct mutex qgroup_ioctl_lock;
722 
723 	/* List of dirty qgroups to be written at next commit. */
724 	struct list_head dirty_qgroups;
725 
726 	/* Used by qgroup for an efficient tree traversal. */
727 	u64 qgroup_seq;
728 
729 	/* Qgroup rescan items. */
730 	/* Protects the progress item */
731 	struct mutex qgroup_rescan_lock;
732 	struct btrfs_key qgroup_rescan_progress;
733 	struct btrfs_workqueue *qgroup_rescan_workers;
734 	struct completion qgroup_rescan_completion;
735 	struct btrfs_work qgroup_rescan_work;
736 	/* Protected by qgroup_rescan_lock */
737 	bool qgroup_rescan_running;
738 	u8 qgroup_drop_subtree_thres;
739 	u64 qgroup_enable_gen;
740 
741 	/*
742 	 * If this is not 0, then it indicates a serious filesystem error has
743 	 * happened and it contains that error (negative errno value).
744 	 */
745 	int fs_error;
746 
747 	/* Filesystem state */
748 	unsigned long fs_state;
749 
750 	struct btrfs_delayed_root *delayed_root;
751 
752 	/* Extent buffer radix tree */
753 	spinlock_t buffer_lock;
754 	/* Entries are eb->start / sectorsize */
755 	struct radix_tree_root buffer_radix;
756 
757 	/* Next backup root to be overwritten */
758 	int backup_root_index;
759 
760 	/* Device replace state */
761 	struct btrfs_dev_replace dev_replace;
762 
763 	struct semaphore uuid_tree_rescan_sem;
764 
765 	/* Used to reclaim the metadata space in the background. */
766 	struct work_struct async_reclaim_work;
767 	struct work_struct async_data_reclaim_work;
768 	struct work_struct preempt_reclaim_work;
769 
770 	/* Reclaim partially filled block groups in the background */
771 	struct work_struct reclaim_bgs_work;
772 	/* Protected by unused_bgs_lock. */
773 	struct list_head reclaim_bgs;
774 	int bg_reclaim_threshold;
775 
776 	/* Protects the lists unused_bgs and reclaim_bgs. */
777 	spinlock_t unused_bgs_lock;
778 	/* Protected by unused_bgs_lock. */
779 	struct list_head unused_bgs;
780 	struct mutex unused_bg_unpin_mutex;
781 	/* Protect block groups that are going to be deleted */
782 	struct mutex reclaim_bgs_lock;
783 
784 	/* Cached block sizes */
785 	u32 nodesize;
786 	u32 sectorsize;
787 	/* ilog2 of sectorsize, use to avoid 64bit division */
788 	u32 sectorsize_bits;
789 	u32 csum_size;
790 	u32 csums_per_leaf;
791 	u32 stripesize;
792 
793 	/*
794 	 * Maximum size of an extent. BTRFS_MAX_EXTENT_SIZE on regular
795 	 * filesystem, on zoned it depends on the device constraints.
796 	 */
797 	u64 max_extent_size;
798 
799 	/* Block groups and devices containing active swapfiles. */
800 	spinlock_t swapfile_pins_lock;
801 	struct rb_root swapfile_pins;
802 
803 	struct crypto_shash *csum_shash;
804 
805 	/* Type of exclusive operation running, protected by super_lock */
806 	enum btrfs_exclusive_operation exclusive_operation;
807 
808 	/*
809 	 * Zone size > 0 when in ZONED mode, otherwise it's used for a check
810 	 * if the mode is enabled
811 	 */
812 	u64 zone_size;
813 
814 	/* Constraints for ZONE_APPEND commands: */
815 	struct queue_limits limits;
816 	u64 max_zone_append_size;
817 
818 	struct mutex zoned_meta_io_lock;
819 	spinlock_t treelog_bg_lock;
820 	u64 treelog_bg;
821 
822 	/*
823 	 * Start of the dedicated data relocation block group, protected by
824 	 * relocation_bg_lock.
825 	 */
826 	spinlock_t relocation_bg_lock;
827 	u64 data_reloc_bg;
828 	struct mutex zoned_data_reloc_io_lock;
829 
830 	struct btrfs_block_group *active_meta_bg;
831 	struct btrfs_block_group *active_system_bg;
832 
833 	u64 nr_global_roots;
834 
835 	spinlock_t zone_active_bgs_lock;
836 	struct list_head zone_active_bgs;
837 
838 	/* Updates are not protected by any lock */
839 	struct btrfs_commit_stats commit_stats;
840 
841 	/*
842 	 * Last generation where we dropped a non-relocation root.
843 	 * Use btrfs_set_last_root_drop_gen() and btrfs_get_last_root_drop_gen()
844 	 * to change it and to read it, respectively.
845 	 */
846 	u64 last_root_drop_gen;
847 
848 	/*
849 	 * Annotations for transaction events (structures are empty when
850 	 * compiled without lockdep).
851 	 */
852 	struct lockdep_map btrfs_trans_num_writers_map;
853 	struct lockdep_map btrfs_trans_num_extwriters_map;
854 	struct lockdep_map btrfs_state_change_map[4];
855 	struct lockdep_map btrfs_trans_pending_ordered_map;
856 	struct lockdep_map btrfs_ordered_extent_map;
857 
858 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
859 	spinlock_t ref_verify_lock;
860 	struct rb_root block_tree;
861 #endif
862 
863 #ifdef CONFIG_BTRFS_DEBUG
864 	struct kobject *debug_kobj;
865 	struct list_head allocated_roots;
866 
867 	spinlock_t eb_leak_lock;
868 	struct list_head allocated_ebs;
869 #endif
870 };
871 
872 #define page_to_inode(_page)	(BTRFS_I(_Generic((_page),			\
873 					  struct page *: (_page))->mapping->host))
874 #define folio_to_inode(_folio)	(BTRFS_I(_Generic((_folio),			\
875 					  struct folio *: (_folio))->mapping->host))
876 
877 #define page_to_fs_info(_page)	 (page_to_inode(_page)->root->fs_info)
878 #define folio_to_fs_info(_folio) (folio_to_inode(_folio)->root->fs_info)
879 
880 #define inode_to_fs_info(_inode) (BTRFS_I(_Generic((_inode),			\
881 					   struct inode *: (_inode)))->root->fs_info)
882 
883 static inline u64 btrfs_get_fs_generation(const struct btrfs_fs_info *fs_info)
884 {
885 	return READ_ONCE(fs_info->generation);
886 }
887 
888 static inline void btrfs_set_fs_generation(struct btrfs_fs_info *fs_info, u64 gen)
889 {
890 	WRITE_ONCE(fs_info->generation, gen);
891 }
892 
893 static inline u64 btrfs_get_last_trans_committed(const struct btrfs_fs_info *fs_info)
894 {
895 	return READ_ONCE(fs_info->last_trans_committed);
896 }
897 
898 static inline void btrfs_set_last_trans_committed(struct btrfs_fs_info *fs_info, u64 gen)
899 {
900 	WRITE_ONCE(fs_info->last_trans_committed, gen);
901 }
902 
903 static inline void btrfs_set_last_root_drop_gen(struct btrfs_fs_info *fs_info,
904 						u64 gen)
905 {
906 	WRITE_ONCE(fs_info->last_root_drop_gen, gen);
907 }
908 
909 static inline u64 btrfs_get_last_root_drop_gen(const struct btrfs_fs_info *fs_info)
910 {
911 	return READ_ONCE(fs_info->last_root_drop_gen);
912 }
913 
914 /*
915  * Take the number of bytes to be checksummed and figure out how many leaves
916  * it would require to store the csums for that many bytes.
917  */
918 static inline u64 btrfs_csum_bytes_to_leaves(
919 			const struct btrfs_fs_info *fs_info, u64 csum_bytes)
920 {
921 	const u64 num_csums = csum_bytes >> fs_info->sectorsize_bits;
922 
923 	return DIV_ROUND_UP_ULL(num_csums, fs_info->csums_per_leaf);
924 }
925 
926 /*
927  * Use this if we would be adding new items, as we could split nodes as we cow
928  * down the tree.
929  */
930 static inline u64 btrfs_calc_insert_metadata_size(const struct btrfs_fs_info *fs_info,
931 						  unsigned num_items)
932 {
933 	return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * 2 * num_items;
934 }
935 
936 /*
937  * Doing a truncate or a modification won't result in new nodes or leaves, just
938  * what we need for COW.
939  */
940 static inline u64 btrfs_calc_metadata_size(const struct btrfs_fs_info *fs_info,
941 						 unsigned num_items)
942 {
943 	return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * num_items;
944 }
945 
946 #define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r->fs_info) >> 4) - \
947 					sizeof(struct btrfs_item))
948 
949 static inline bool btrfs_is_zoned(const struct btrfs_fs_info *fs_info)
950 {
951 	return IS_ENABLED(CONFIG_BLK_DEV_ZONED) && fs_info->zone_size > 0;
952 }
953 
954 /*
955  * Count how many fs_info->max_extent_size cover the @size
956  */
957 static inline u32 count_max_extents(struct btrfs_fs_info *fs_info, u64 size)
958 {
959 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
960 	if (!fs_info)
961 		return div_u64(size + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE);
962 #endif
963 
964 	return div_u64(size + fs_info->max_extent_size - 1, fs_info->max_extent_size);
965 }
966 
967 bool btrfs_exclop_start(struct btrfs_fs_info *fs_info,
968 			enum btrfs_exclusive_operation type);
969 bool btrfs_exclop_start_try_lock(struct btrfs_fs_info *fs_info,
970 				 enum btrfs_exclusive_operation type);
971 void btrfs_exclop_start_unlock(struct btrfs_fs_info *fs_info);
972 void btrfs_exclop_finish(struct btrfs_fs_info *fs_info);
973 void btrfs_exclop_balance(struct btrfs_fs_info *fs_info,
974 			  enum btrfs_exclusive_operation op);
975 
976 int btrfs_check_ioctl_vol_args_path(const struct btrfs_ioctl_vol_args *vol_args);
977 
978 /* Compatibility and incompatibility defines */
979 void __btrfs_set_fs_incompat(struct btrfs_fs_info *fs_info, u64 flag,
980 			     const char *name);
981 void __btrfs_clear_fs_incompat(struct btrfs_fs_info *fs_info, u64 flag,
982 			       const char *name);
983 void __btrfs_set_fs_compat_ro(struct btrfs_fs_info *fs_info, u64 flag,
984 			      const char *name);
985 void __btrfs_clear_fs_compat_ro(struct btrfs_fs_info *fs_info, u64 flag,
986 				const char *name);
987 
988 #define __btrfs_fs_incompat(fs_info, flags)				\
989 	(!!(btrfs_super_incompat_flags((fs_info)->super_copy) & (flags)))
990 
991 #define __btrfs_fs_compat_ro(fs_info, flags)				\
992 	(!!(btrfs_super_compat_ro_flags((fs_info)->super_copy) & (flags)))
993 
994 #define btrfs_set_fs_incompat(__fs_info, opt)				\
995 	__btrfs_set_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt, #opt)
996 
997 #define btrfs_clear_fs_incompat(__fs_info, opt)				\
998 	__btrfs_clear_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt, #opt)
999 
1000 #define btrfs_fs_incompat(fs_info, opt)					\
1001 	__btrfs_fs_incompat((fs_info), BTRFS_FEATURE_INCOMPAT_##opt)
1002 
1003 #define btrfs_set_fs_compat_ro(__fs_info, opt)				\
1004 	__btrfs_set_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt, #opt)
1005 
1006 #define btrfs_clear_fs_compat_ro(__fs_info, opt)			\
1007 	__btrfs_clear_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt, #opt)
1008 
1009 #define btrfs_fs_compat_ro(fs_info, opt)				\
1010 	__btrfs_fs_compat_ro((fs_info), BTRFS_FEATURE_COMPAT_RO_##opt)
1011 
1012 #define btrfs_clear_opt(o, opt)		((o) &= ~BTRFS_MOUNT_##opt)
1013 #define btrfs_set_opt(o, opt)		((o) |= BTRFS_MOUNT_##opt)
1014 #define btrfs_raw_test_opt(o, opt)	((o) & BTRFS_MOUNT_##opt)
1015 #define btrfs_test_opt(fs_info, opt)	((fs_info)->mount_opt & \
1016 					 BTRFS_MOUNT_##opt)
1017 
1018 static inline int btrfs_fs_closing(struct btrfs_fs_info *fs_info)
1019 {
1020 	/* Do it this way so we only ever do one test_bit in the normal case. */
1021 	if (test_bit(BTRFS_FS_CLOSING_START, &fs_info->flags)) {
1022 		if (test_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags))
1023 			return 2;
1024 		return 1;
1025 	}
1026 	return 0;
1027 }
1028 
1029 /*
1030  * If we remount the fs to be R/O or umount the fs, the cleaner needn't do
1031  * anything except sleeping. This function is used to check the status of
1032  * the fs.
1033  * We check for BTRFS_FS_STATE_RO to avoid races with a concurrent remount,
1034  * since setting and checking for SB_RDONLY in the superblock's flags is not
1035  * atomic.
1036  */
1037 static inline int btrfs_need_cleaner_sleep(struct btrfs_fs_info *fs_info)
1038 {
1039 	return test_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state) ||
1040 		btrfs_fs_closing(fs_info);
1041 }
1042 
1043 static inline void btrfs_wake_unfinished_drop(struct btrfs_fs_info *fs_info)
1044 {
1045 	clear_and_wake_up_bit(BTRFS_FS_UNFINISHED_DROPS, &fs_info->flags);
1046 }
1047 
1048 #define BTRFS_FS_ERROR(fs_info)	(READ_ONCE((fs_info)->fs_error))
1049 
1050 #define BTRFS_FS_LOG_CLEANUP_ERROR(fs_info)				\
1051 	(unlikely(test_bit(BTRFS_FS_STATE_LOG_CLEANUP_ERROR,		\
1052 			   &(fs_info)->fs_state)))
1053 
1054 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1055 
1056 #define EXPORT_FOR_TESTS
1057 
1058 static inline int btrfs_is_testing(struct btrfs_fs_info *fs_info)
1059 {
1060 	return test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
1061 }
1062 
1063 void btrfs_test_destroy_inode(struct inode *inode);
1064 
1065 #else
1066 
1067 #define EXPORT_FOR_TESTS static
1068 
1069 static inline int btrfs_is_testing(struct btrfs_fs_info *fs_info)
1070 {
1071 	return 0;
1072 }
1073 #endif
1074 
1075 #endif
1076