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_WARNING_COMMIT_INTERVAL	(300)
289 #define BTRFS_DEFAULT_MAX_INLINE	(2048)
290 
291 struct btrfs_dev_replace {
292 	/* See #define above */
293 	u64 replace_state;
294 	/* Seconds since 1-Jan-1970 */
295 	time64_t time_started;
296 	/* Seconds since 1-Jan-1970 */
297 	time64_t time_stopped;
298 	atomic64_t num_write_errors;
299 	atomic64_t num_uncorrectable_read_errors;
300 
301 	u64 cursor_left;
302 	u64 committed_cursor_left;
303 	u64 cursor_left_last_write_of_item;
304 	u64 cursor_right;
305 
306 	/* See #define above */
307 	u64 cont_reading_from_srcdev_mode;
308 
309 	int is_valid;
310 	int item_needs_writeback;
311 	struct btrfs_device *srcdev;
312 	struct btrfs_device *tgtdev;
313 
314 	struct mutex lock_finishing_cancel_unmount;
315 	struct rw_semaphore rwsem;
316 
317 	struct btrfs_scrub_progress scrub_progress;
318 
319 	struct percpu_counter bio_counter;
320 	wait_queue_head_t replace_wait;
321 
322 	struct task_struct *replace_task;
323 };
324 
325 /*
326  * Free clusters are used to claim free space in relatively large chunks,
327  * allowing us to do less seeky writes. They are used for all metadata
328  * allocations. In ssd_spread mode they are also used for data allocations.
329  */
330 struct btrfs_free_cluster {
331 	spinlock_t lock;
332 	spinlock_t refill_lock;
333 	struct rb_root root;
334 
335 	/* Largest extent in this cluster */
336 	u64 max_size;
337 
338 	/* First extent starting offset */
339 	u64 window_start;
340 
341 	/* We did a full search and couldn't create a cluster */
342 	bool fragmented;
343 
344 	struct btrfs_block_group *block_group;
345 	/*
346 	 * When a cluster is allocated from a block group, we put the cluster
347 	 * onto a list in the block group so that it can be freed before the
348 	 * block group is freed.
349 	 */
350 	struct list_head block_group_list;
351 };
352 
353 /* Discard control. */
354 /*
355  * Async discard uses multiple lists to differentiate the discard filter
356  * parameters.  Index 0 is for completely free block groups where we need to
357  * ensure the entire block group is trimmed without being lossy.  Indices
358  * afterwards represent monotonically decreasing discard filter sizes to
359  * prioritize what should be discarded next.
360  */
361 #define BTRFS_NR_DISCARD_LISTS		3
362 #define BTRFS_DISCARD_INDEX_UNUSED	0
363 #define BTRFS_DISCARD_INDEX_START	1
364 
365 struct btrfs_discard_ctl {
366 	struct workqueue_struct *discard_workers;
367 	struct delayed_work work;
368 	spinlock_t lock;
369 	struct btrfs_block_group *block_group;
370 	struct list_head discard_list[BTRFS_NR_DISCARD_LISTS];
371 	u64 prev_discard;
372 	u64 prev_discard_time;
373 	atomic_t discardable_extents;
374 	atomic64_t discardable_bytes;
375 	u64 max_discard_size;
376 	u64 delay_ms;
377 	u32 iops_limit;
378 	u32 kbps_limit;
379 	u64 discard_extent_bytes;
380 	u64 discard_bitmap_bytes;
381 	atomic64_t discard_bytes_saved;
382 };
383 
384 /*
385  * Exclusive operations (device replace, resize, device add/remove, balance)
386  */
387 enum btrfs_exclusive_operation {
388 	BTRFS_EXCLOP_NONE,
389 	BTRFS_EXCLOP_BALANCE_PAUSED,
390 	BTRFS_EXCLOP_BALANCE,
391 	BTRFS_EXCLOP_DEV_ADD,
392 	BTRFS_EXCLOP_DEV_REMOVE,
393 	BTRFS_EXCLOP_DEV_REPLACE,
394 	BTRFS_EXCLOP_RESIZE,
395 	BTRFS_EXCLOP_SWAP_ACTIVATE,
396 };
397 
398 /* Store data about transaction commits, exported via sysfs. */
399 struct btrfs_commit_stats {
400 	/* Total number of commits */
401 	u64 commit_count;
402 	/* The maximum commit duration so far in ns */
403 	u64 max_commit_dur;
404 	/* The last commit duration in ns */
405 	u64 last_commit_dur;
406 	/* The total commit duration in ns */
407 	u64 total_commit_dur;
408 };
409 
410 struct btrfs_fs_info {
411 	u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
412 	unsigned long flags;
413 	struct btrfs_root *tree_root;
414 	struct btrfs_root *chunk_root;
415 	struct btrfs_root *dev_root;
416 	struct btrfs_root *fs_root;
417 	struct btrfs_root *quota_root;
418 	struct btrfs_root *uuid_root;
419 	struct btrfs_root *data_reloc_root;
420 	struct btrfs_root *block_group_root;
421 	struct btrfs_root *stripe_root;
422 
423 	/* The log root tree is a directory of all the other log roots */
424 	struct btrfs_root *log_root_tree;
425 
426 	/* The tree that holds the global roots (csum, extent, etc) */
427 	rwlock_t global_root_lock;
428 	struct rb_root global_root_tree;
429 
430 	spinlock_t fs_roots_radix_lock;
431 	struct radix_tree_root fs_roots_radix;
432 
433 	/* Block group cache stuff */
434 	rwlock_t block_group_cache_lock;
435 	struct rb_root_cached block_group_cache_tree;
436 
437 	/* Keep track of unallocated space */
438 	atomic64_t free_chunk_space;
439 
440 	/* Track ranges which are used by log trees blocks/logged data extents */
441 	struct extent_io_tree excluded_extents;
442 
443 	/* logical->physical extent mapping */
444 	struct rb_root_cached mapping_tree;
445 	rwlock_t mapping_tree_lock;
446 
447 	/*
448 	 * Block reservation for extent, checksum, root tree and delayed dir
449 	 * index item.
450 	 */
451 	struct btrfs_block_rsv global_block_rsv;
452 	/* Block reservation for metadata operations */
453 	struct btrfs_block_rsv trans_block_rsv;
454 	/* Block reservation for chunk tree */
455 	struct btrfs_block_rsv chunk_block_rsv;
456 	/* Block reservation for delayed operations */
457 	struct btrfs_block_rsv delayed_block_rsv;
458 	/* Block reservation for delayed refs */
459 	struct btrfs_block_rsv delayed_refs_rsv;
460 
461 	struct btrfs_block_rsv empty_block_rsv;
462 
463 	/*
464 	 * Updated while holding the lock 'trans_lock'. Due to the life cycle of
465 	 * a transaction, it can be directly read while holding a transaction
466 	 * handle, everywhere else must be read with btrfs_get_fs_generation().
467 	 * Should always be updated using btrfs_set_fs_generation().
468 	 */
469 	u64 generation;
470 	/*
471 	 * Always use btrfs_get_last_trans_committed() and
472 	 * btrfs_set_last_trans_committed() to read and update this field.
473 	 */
474 	u64 last_trans_committed;
475 	/*
476 	 * Generation of the last transaction used for block group relocation
477 	 * since the filesystem was last mounted (or 0 if none happened yet).
478 	 * Must be written and read while holding btrfs_fs_info::commit_root_sem.
479 	 */
480 	u64 last_reloc_trans;
481 
482 	/*
483 	 * This is updated to the current trans every time a full commit is
484 	 * required instead of the faster short fsync log commits
485 	 */
486 	u64 last_trans_log_full_commit;
487 	unsigned long long mount_opt;
488 
489 	unsigned long compress_type:4;
490 	unsigned int compress_level;
491 	u32 commit_interval;
492 	/*
493 	 * It is a suggestive number, the read side is safe even it gets a
494 	 * wrong number because we will write out the data into a regular
495 	 * extent. The write side(mount/remount) is under ->s_umount lock,
496 	 * so it is also safe.
497 	 */
498 	u64 max_inline;
499 
500 	struct btrfs_transaction *running_transaction;
501 	wait_queue_head_t transaction_throttle;
502 	wait_queue_head_t transaction_wait;
503 	wait_queue_head_t transaction_blocked_wait;
504 	wait_queue_head_t async_submit_wait;
505 
506 	/*
507 	 * Used to protect the incompat_flags, compat_flags, compat_ro_flags
508 	 * when they are updated.
509 	 *
510 	 * Because we do not clear the flags for ever, so we needn't use
511 	 * the lock on the read side.
512 	 *
513 	 * We also needn't use the lock when we mount the fs, because
514 	 * there is no other task which will update the flag.
515 	 */
516 	spinlock_t super_lock;
517 	struct btrfs_super_block *super_copy;
518 	struct btrfs_super_block *super_for_commit;
519 	struct super_block *sb;
520 	struct inode *btree_inode;
521 	struct mutex tree_log_mutex;
522 	struct mutex transaction_kthread_mutex;
523 	struct mutex cleaner_mutex;
524 	struct mutex chunk_mutex;
525 
526 	/*
527 	 * This is taken to make sure we don't set block groups ro after the
528 	 * free space cache has been allocated on them.
529 	 */
530 	struct mutex ro_block_group_mutex;
531 
532 	/*
533 	 * This is used during read/modify/write to make sure no two ios are
534 	 * trying to mod the same stripe at the same time.
535 	 */
536 	struct btrfs_stripe_hash_table *stripe_hash_table;
537 
538 	/*
539 	 * This protects the ordered operations list only while we are
540 	 * processing all of the entries on it.  This way we make sure the
541 	 * commit code doesn't find the list temporarily empty because another
542 	 * function happens to be doing non-waiting preflush before jumping
543 	 * into the main commit.
544 	 */
545 	struct mutex ordered_operations_mutex;
546 
547 	struct rw_semaphore commit_root_sem;
548 
549 	struct rw_semaphore cleanup_work_sem;
550 
551 	struct rw_semaphore subvol_sem;
552 
553 	spinlock_t trans_lock;
554 	/*
555 	 * The reloc mutex goes with the trans lock, it is taken during commit
556 	 * to protect us from the relocation code.
557 	 */
558 	struct mutex reloc_mutex;
559 
560 	struct list_head trans_list;
561 	struct list_head dead_roots;
562 	struct list_head caching_block_groups;
563 
564 	spinlock_t delayed_iput_lock;
565 	struct list_head delayed_iputs;
566 	atomic_t nr_delayed_iputs;
567 	wait_queue_head_t delayed_iputs_wait;
568 
569 	atomic64_t tree_mod_seq;
570 
571 	/* This protects tree_mod_log and tree_mod_seq_list */
572 	rwlock_t tree_mod_log_lock;
573 	struct rb_root tree_mod_log;
574 	struct list_head tree_mod_seq_list;
575 
576 	atomic_t async_delalloc_pages;
577 
578 	/* This is used to protect the following list -- ordered_roots. */
579 	spinlock_t ordered_root_lock;
580 
581 	/*
582 	 * All fs/file tree roots in which there are data=ordered extents
583 	 * pending writeback are added into this list.
584 	 *
585 	 * These can span multiple transactions and basically include every
586 	 * dirty data page that isn't from nodatacow.
587 	 */
588 	struct list_head ordered_roots;
589 
590 	struct mutex delalloc_root_mutex;
591 	spinlock_t delalloc_root_lock;
592 	/* All fs/file tree roots that have delalloc inodes. */
593 	struct list_head delalloc_roots;
594 
595 	/*
596 	 * There is a pool of worker threads for checksumming during writes and
597 	 * a pool for checksumming after reads.  This is because readers can
598 	 * run with FS locks held, and the writers may be waiting for those
599 	 * locks.  We don't want ordering in the pending list to cause
600 	 * deadlocks, and so the two are serviced separately.
601 	 *
602 	 * A third pool does submit_bio to avoid deadlocking with the other two.
603 	 */
604 	struct btrfs_workqueue *workers;
605 	struct btrfs_workqueue *delalloc_workers;
606 	struct btrfs_workqueue *flush_workers;
607 	struct workqueue_struct *endio_workers;
608 	struct workqueue_struct *endio_meta_workers;
609 	struct workqueue_struct *rmw_workers;
610 	struct workqueue_struct *compressed_write_workers;
611 	struct btrfs_workqueue *endio_write_workers;
612 	struct btrfs_workqueue *endio_freespace_worker;
613 	struct btrfs_workqueue *caching_workers;
614 
615 	/*
616 	 * Fixup workers take dirty pages that didn't properly go through the
617 	 * cow mechanism and make them safe to write.  It happens for the
618 	 * sys_munmap function call path.
619 	 */
620 	struct btrfs_workqueue *fixup_workers;
621 	struct btrfs_workqueue *delayed_workers;
622 
623 	struct task_struct *transaction_kthread;
624 	struct task_struct *cleaner_kthread;
625 	u32 thread_pool_size;
626 
627 	struct kobject *space_info_kobj;
628 	struct kobject *qgroups_kobj;
629 	struct kobject *discard_kobj;
630 
631 	/* Used to keep from writing metadata until there is a nice batch */
632 	struct percpu_counter dirty_metadata_bytes;
633 	struct percpu_counter delalloc_bytes;
634 	struct percpu_counter ordered_bytes;
635 	s32 dirty_metadata_batch;
636 	s32 delalloc_batch;
637 
638 	struct percpu_counter evictable_extent_maps;
639 	spinlock_t extent_map_shrinker_lock;
640 	u64 extent_map_shrinker_last_root;
641 	u64 extent_map_shrinker_last_ino;
642 	atomic64_t extent_map_shrinker_nr_to_scan;
643 	struct work_struct extent_map_shrinker_work;
644 
645 	/* Protected by 'trans_lock'. */
646 	struct list_head dirty_cowonly_roots;
647 
648 	struct btrfs_fs_devices *fs_devices;
649 
650 	/*
651 	 * The space_info list is effectively read only after initial setup.
652 	 * It is populated at mount time and cleaned up after all block groups
653 	 * are removed.  RCU is used to protect it.
654 	 */
655 	struct list_head space_info;
656 
657 	struct btrfs_space_info *data_sinfo;
658 
659 	struct reloc_control *reloc_ctl;
660 
661 	/* data_alloc_cluster is only used in ssd_spread mode */
662 	struct btrfs_free_cluster data_alloc_cluster;
663 
664 	/* All metadata allocations go through this cluster. */
665 	struct btrfs_free_cluster meta_alloc_cluster;
666 
667 	/* Auto defrag inodes go here. */
668 	spinlock_t defrag_inodes_lock;
669 	struct rb_root defrag_inodes;
670 	atomic_t defrag_running;
671 
672 	/* Used to protect avail_{data, metadata, system}_alloc_bits */
673 	seqlock_t profiles_lock;
674 	/*
675 	 * These three are in extended format (availability of single chunks is
676 	 * denoted by BTRFS_AVAIL_ALLOC_BIT_SINGLE bit, other types are denoted
677 	 * by corresponding BTRFS_BLOCK_GROUP_* bits)
678 	 */
679 	u64 avail_data_alloc_bits;
680 	u64 avail_metadata_alloc_bits;
681 	u64 avail_system_alloc_bits;
682 
683 	/* Balance state */
684 	spinlock_t balance_lock;
685 	struct mutex balance_mutex;
686 	atomic_t balance_pause_req;
687 	atomic_t balance_cancel_req;
688 	struct btrfs_balance_control *balance_ctl;
689 	wait_queue_head_t balance_wait_q;
690 
691 	/* Cancellation requests for chunk relocation */
692 	atomic_t reloc_cancel_req;
693 
694 	u32 data_chunk_allocations;
695 	u32 metadata_ratio;
696 
697 	void *bdev_holder;
698 
699 	/* Private scrub information */
700 	struct mutex scrub_lock;
701 	atomic_t scrubs_running;
702 	atomic_t scrub_pause_req;
703 	atomic_t scrubs_paused;
704 	atomic_t scrub_cancel_req;
705 	wait_queue_head_t scrub_pause_wait;
706 	/*
707 	 * The worker pointers are NULL iff the refcount is 0, ie. scrub is not
708 	 * running.
709 	 */
710 	refcount_t scrub_workers_refcnt;
711 	u32 sectors_per_page;
712 	struct workqueue_struct *scrub_workers;
713 
714 	struct btrfs_discard_ctl discard_ctl;
715 
716 	/* Is qgroup tracking in a consistent state? */
717 	u64 qgroup_flags;
718 
719 	/* Holds configuration and tracking. Protected by qgroup_lock. */
720 	struct rb_root qgroup_tree;
721 	spinlock_t qgroup_lock;
722 
723 	/*
724 	 * Used to avoid frequently calling ulist_alloc()/ulist_free()
725 	 * when doing qgroup accounting, it must be protected by qgroup_lock.
726 	 */
727 	struct ulist *qgroup_ulist;
728 
729 	/*
730 	 * Protect user change for quota operations. If a transaction is needed,
731 	 * it must be started before locking this lock.
732 	 */
733 	struct mutex qgroup_ioctl_lock;
734 
735 	/* List of dirty qgroups to be written at next commit. */
736 	struct list_head dirty_qgroups;
737 
738 	/* Used by qgroup for an efficient tree traversal. */
739 	u64 qgroup_seq;
740 
741 	/* Qgroup rescan items. */
742 	/* Protects the progress item */
743 	struct mutex qgroup_rescan_lock;
744 	struct btrfs_key qgroup_rescan_progress;
745 	struct btrfs_workqueue *qgroup_rescan_workers;
746 	struct completion qgroup_rescan_completion;
747 	struct btrfs_work qgroup_rescan_work;
748 	/* Protected by qgroup_rescan_lock */
749 	bool qgroup_rescan_running;
750 	u8 qgroup_drop_subtree_thres;
751 	u64 qgroup_enable_gen;
752 
753 	/*
754 	 * If this is not 0, then it indicates a serious filesystem error has
755 	 * happened and it contains that error (negative errno value).
756 	 */
757 	int fs_error;
758 
759 	/* Filesystem state */
760 	unsigned long fs_state;
761 
762 	struct btrfs_delayed_root *delayed_root;
763 
764 	/* Extent buffer radix tree */
765 	spinlock_t buffer_lock;
766 	/* Entries are eb->start / sectorsize */
767 	struct radix_tree_root buffer_radix;
768 
769 	/* Next backup root to be overwritten */
770 	int backup_root_index;
771 
772 	/* Device replace state */
773 	struct btrfs_dev_replace dev_replace;
774 
775 	struct semaphore uuid_tree_rescan_sem;
776 
777 	/* Used to reclaim the metadata space in the background. */
778 	struct work_struct async_reclaim_work;
779 	struct work_struct async_data_reclaim_work;
780 	struct work_struct preempt_reclaim_work;
781 
782 	/* Reclaim partially filled block groups in the background */
783 	struct work_struct reclaim_bgs_work;
784 	/* Protected by unused_bgs_lock. */
785 	struct list_head reclaim_bgs;
786 	int bg_reclaim_threshold;
787 
788 	/* Protects the lists unused_bgs and reclaim_bgs. */
789 	spinlock_t unused_bgs_lock;
790 	/* Protected by unused_bgs_lock. */
791 	struct list_head unused_bgs;
792 	struct mutex unused_bg_unpin_mutex;
793 	/* Protect block groups that are going to be deleted */
794 	struct mutex reclaim_bgs_lock;
795 
796 	/* Cached block sizes */
797 	u32 nodesize;
798 	u32 sectorsize;
799 	/* ilog2 of sectorsize, use to avoid 64bit division */
800 	u32 sectorsize_bits;
801 	u32 csum_size;
802 	u32 csums_per_leaf;
803 	u32 stripesize;
804 
805 	/*
806 	 * Maximum size of an extent. BTRFS_MAX_EXTENT_SIZE on regular
807 	 * filesystem, on zoned it depends on the device constraints.
808 	 */
809 	u64 max_extent_size;
810 
811 	/* Block groups and devices containing active swapfiles. */
812 	spinlock_t swapfile_pins_lock;
813 	struct rb_root swapfile_pins;
814 
815 	struct crypto_shash *csum_shash;
816 
817 	/* Type of exclusive operation running, protected by super_lock */
818 	enum btrfs_exclusive_operation exclusive_operation;
819 
820 	/*
821 	 * Zone size > 0 when in ZONED mode, otherwise it's used for a check
822 	 * if the mode is enabled
823 	 */
824 	u64 zone_size;
825 
826 	/* Constraints for ZONE_APPEND commands: */
827 	struct queue_limits limits;
828 	u64 max_zone_append_size;
829 
830 	struct mutex zoned_meta_io_lock;
831 	spinlock_t treelog_bg_lock;
832 	u64 treelog_bg;
833 
834 	/*
835 	 * Start of the dedicated data relocation block group, protected by
836 	 * relocation_bg_lock.
837 	 */
838 	spinlock_t relocation_bg_lock;
839 	u64 data_reloc_bg;
840 	struct mutex zoned_data_reloc_io_lock;
841 
842 	struct btrfs_block_group *active_meta_bg;
843 	struct btrfs_block_group *active_system_bg;
844 
845 	u64 nr_global_roots;
846 
847 	spinlock_t zone_active_bgs_lock;
848 	struct list_head zone_active_bgs;
849 
850 	/* Updates are not protected by any lock */
851 	struct btrfs_commit_stats commit_stats;
852 
853 	/*
854 	 * Last generation where we dropped a non-relocation root.
855 	 * Use btrfs_set_last_root_drop_gen() and btrfs_get_last_root_drop_gen()
856 	 * to change it and to read it, respectively.
857 	 */
858 	u64 last_root_drop_gen;
859 
860 	/*
861 	 * Annotations for transaction events (structures are empty when
862 	 * compiled without lockdep).
863 	 */
864 	struct lockdep_map btrfs_trans_num_writers_map;
865 	struct lockdep_map btrfs_trans_num_extwriters_map;
866 	struct lockdep_map btrfs_state_change_map[4];
867 	struct lockdep_map btrfs_trans_pending_ordered_map;
868 	struct lockdep_map btrfs_ordered_extent_map;
869 
870 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
871 	spinlock_t ref_verify_lock;
872 	struct rb_root block_tree;
873 #endif
874 
875 #ifdef CONFIG_BTRFS_DEBUG
876 	struct kobject *debug_kobj;
877 	struct list_head allocated_roots;
878 
879 	spinlock_t eb_leak_lock;
880 	struct list_head allocated_ebs;
881 #endif
882 };
883 
884 #define page_to_inode(_page)	(BTRFS_I(_Generic((_page),			\
885 					  struct page *: (_page))->mapping->host))
886 #define folio_to_inode(_folio)	(BTRFS_I(_Generic((_folio),			\
887 					  struct folio *: (_folio))->mapping->host))
888 
889 #define page_to_fs_info(_page)	 (page_to_inode(_page)->root->fs_info)
890 #define folio_to_fs_info(_folio) (folio_to_inode(_folio)->root->fs_info)
891 
892 #define inode_to_fs_info(_inode) (BTRFS_I(_Generic((_inode),			\
893 					   struct inode *: (_inode)))->root->fs_info)
894 
btrfs_get_fs_generation(const struct btrfs_fs_info * fs_info)895 static inline u64 btrfs_get_fs_generation(const struct btrfs_fs_info *fs_info)
896 {
897 	return READ_ONCE(fs_info->generation);
898 }
899 
btrfs_set_fs_generation(struct btrfs_fs_info * fs_info,u64 gen)900 static inline void btrfs_set_fs_generation(struct btrfs_fs_info *fs_info, u64 gen)
901 {
902 	WRITE_ONCE(fs_info->generation, gen);
903 }
904 
btrfs_get_last_trans_committed(const struct btrfs_fs_info * fs_info)905 static inline u64 btrfs_get_last_trans_committed(const struct btrfs_fs_info *fs_info)
906 {
907 	return READ_ONCE(fs_info->last_trans_committed);
908 }
909 
btrfs_set_last_trans_committed(struct btrfs_fs_info * fs_info,u64 gen)910 static inline void btrfs_set_last_trans_committed(struct btrfs_fs_info *fs_info, u64 gen)
911 {
912 	WRITE_ONCE(fs_info->last_trans_committed, gen);
913 }
914 
btrfs_set_last_root_drop_gen(struct btrfs_fs_info * fs_info,u64 gen)915 static inline void btrfs_set_last_root_drop_gen(struct btrfs_fs_info *fs_info,
916 						u64 gen)
917 {
918 	WRITE_ONCE(fs_info->last_root_drop_gen, gen);
919 }
920 
btrfs_get_last_root_drop_gen(const struct btrfs_fs_info * fs_info)921 static inline u64 btrfs_get_last_root_drop_gen(const struct btrfs_fs_info *fs_info)
922 {
923 	return READ_ONCE(fs_info->last_root_drop_gen);
924 }
925 
926 /*
927  * Take the number of bytes to be checksummed and figure out how many leaves
928  * it would require to store the csums for that many bytes.
929  */
btrfs_csum_bytes_to_leaves(const struct btrfs_fs_info * fs_info,u64 csum_bytes)930 static inline u64 btrfs_csum_bytes_to_leaves(
931 			const struct btrfs_fs_info *fs_info, u64 csum_bytes)
932 {
933 	const u64 num_csums = csum_bytes >> fs_info->sectorsize_bits;
934 
935 	return DIV_ROUND_UP_ULL(num_csums, fs_info->csums_per_leaf);
936 }
937 
938 /*
939  * Use this if we would be adding new items, as we could split nodes as we cow
940  * down the tree.
941  */
btrfs_calc_insert_metadata_size(const struct btrfs_fs_info * fs_info,unsigned num_items)942 static inline u64 btrfs_calc_insert_metadata_size(const struct btrfs_fs_info *fs_info,
943 						  unsigned num_items)
944 {
945 	return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * 2 * num_items;
946 }
947 
948 /*
949  * Doing a truncate or a modification won't result in new nodes or leaves, just
950  * what we need for COW.
951  */
btrfs_calc_metadata_size(const struct btrfs_fs_info * fs_info,unsigned num_items)952 static inline u64 btrfs_calc_metadata_size(const struct btrfs_fs_info *fs_info,
953 						 unsigned num_items)
954 {
955 	return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * num_items;
956 }
957 
958 #define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r->fs_info) >> 4) - \
959 					sizeof(struct btrfs_item))
960 
btrfs_is_zoned(const struct btrfs_fs_info * fs_info)961 static inline bool btrfs_is_zoned(const struct btrfs_fs_info *fs_info)
962 {
963 	return IS_ENABLED(CONFIG_BLK_DEV_ZONED) && fs_info->zone_size > 0;
964 }
965 
966 /*
967  * Count how many fs_info->max_extent_size cover the @size
968  */
count_max_extents(const struct btrfs_fs_info * fs_info,u64 size)969 static inline u32 count_max_extents(const struct btrfs_fs_info *fs_info, u64 size)
970 {
971 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
972 	if (!fs_info)
973 		return div_u64(size + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE);
974 #endif
975 
976 	return div_u64(size + fs_info->max_extent_size - 1, fs_info->max_extent_size);
977 }
978 
979 bool btrfs_exclop_start(struct btrfs_fs_info *fs_info,
980 			enum btrfs_exclusive_operation type);
981 bool btrfs_exclop_start_try_lock(struct btrfs_fs_info *fs_info,
982 				 enum btrfs_exclusive_operation type);
983 void btrfs_exclop_start_unlock(struct btrfs_fs_info *fs_info);
984 void btrfs_exclop_finish(struct btrfs_fs_info *fs_info);
985 void btrfs_exclop_balance(struct btrfs_fs_info *fs_info,
986 			  enum btrfs_exclusive_operation op);
987 
988 int btrfs_check_ioctl_vol_args_path(const struct btrfs_ioctl_vol_args *vol_args);
989 
990 /* Compatibility and incompatibility defines */
991 void __btrfs_set_fs_incompat(struct btrfs_fs_info *fs_info, u64 flag,
992 			     const char *name);
993 void __btrfs_clear_fs_incompat(struct btrfs_fs_info *fs_info, u64 flag,
994 			       const char *name);
995 void __btrfs_set_fs_compat_ro(struct btrfs_fs_info *fs_info, u64 flag,
996 			      const char *name);
997 void __btrfs_clear_fs_compat_ro(struct btrfs_fs_info *fs_info, u64 flag,
998 				const char *name);
999 
1000 #define __btrfs_fs_incompat(fs_info, flags)				\
1001 	(!!(btrfs_super_incompat_flags((fs_info)->super_copy) & (flags)))
1002 
1003 #define __btrfs_fs_compat_ro(fs_info, flags)				\
1004 	(!!(btrfs_super_compat_ro_flags((fs_info)->super_copy) & (flags)))
1005 
1006 #define btrfs_set_fs_incompat(__fs_info, opt)				\
1007 	__btrfs_set_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt, #opt)
1008 
1009 #define btrfs_clear_fs_incompat(__fs_info, opt)				\
1010 	__btrfs_clear_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt, #opt)
1011 
1012 #define btrfs_fs_incompat(fs_info, opt)					\
1013 	__btrfs_fs_incompat((fs_info), BTRFS_FEATURE_INCOMPAT_##opt)
1014 
1015 #define btrfs_set_fs_compat_ro(__fs_info, opt)				\
1016 	__btrfs_set_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt, #opt)
1017 
1018 #define btrfs_clear_fs_compat_ro(__fs_info, opt)			\
1019 	__btrfs_clear_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt, #opt)
1020 
1021 #define btrfs_fs_compat_ro(fs_info, opt)				\
1022 	__btrfs_fs_compat_ro((fs_info), BTRFS_FEATURE_COMPAT_RO_##opt)
1023 
1024 #define btrfs_clear_opt(o, opt)		((o) &= ~BTRFS_MOUNT_##opt)
1025 #define btrfs_set_opt(o, opt)		((o) |= BTRFS_MOUNT_##opt)
1026 #define btrfs_raw_test_opt(o, opt)	((o) & BTRFS_MOUNT_##opt)
1027 #define btrfs_test_opt(fs_info, opt)	((fs_info)->mount_opt & \
1028 					 BTRFS_MOUNT_##opt)
1029 
btrfs_fs_closing(const struct btrfs_fs_info * fs_info)1030 static inline int btrfs_fs_closing(const struct btrfs_fs_info *fs_info)
1031 {
1032 	/* Do it this way so we only ever do one test_bit in the normal case. */
1033 	if (test_bit(BTRFS_FS_CLOSING_START, &fs_info->flags)) {
1034 		if (test_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags))
1035 			return 2;
1036 		return 1;
1037 	}
1038 	return 0;
1039 }
1040 
1041 /*
1042  * If we remount the fs to be R/O or umount the fs, the cleaner needn't do
1043  * anything except sleeping. This function is used to check the status of
1044  * the fs.
1045  * We check for BTRFS_FS_STATE_RO to avoid races with a concurrent remount,
1046  * since setting and checking for SB_RDONLY in the superblock's flags is not
1047  * atomic.
1048  */
btrfs_need_cleaner_sleep(const struct btrfs_fs_info * fs_info)1049 static inline int btrfs_need_cleaner_sleep(const struct btrfs_fs_info *fs_info)
1050 {
1051 	return test_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state) ||
1052 		btrfs_fs_closing(fs_info);
1053 }
1054 
btrfs_wake_unfinished_drop(struct btrfs_fs_info * fs_info)1055 static inline void btrfs_wake_unfinished_drop(struct btrfs_fs_info *fs_info)
1056 {
1057 	clear_and_wake_up_bit(BTRFS_FS_UNFINISHED_DROPS, &fs_info->flags);
1058 }
1059 
1060 #define BTRFS_FS_ERROR(fs_info)	(READ_ONCE((fs_info)->fs_error))
1061 
1062 #define BTRFS_FS_LOG_CLEANUP_ERROR(fs_info)				\
1063 	(unlikely(test_bit(BTRFS_FS_STATE_LOG_CLEANUP_ERROR,		\
1064 			   &(fs_info)->fs_state)))
1065 
1066 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1067 
1068 #define EXPORT_FOR_TESTS
1069 
btrfs_is_testing(const struct btrfs_fs_info * fs_info)1070 static inline int btrfs_is_testing(const struct btrfs_fs_info *fs_info)
1071 {
1072 	return test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
1073 }
1074 
1075 void btrfs_test_destroy_inode(struct inode *inode);
1076 
1077 #else
1078 
1079 #define EXPORT_FOR_TESTS static
1080 
btrfs_is_testing(const struct btrfs_fs_info * fs_info)1081 static inline int btrfs_is_testing(const struct btrfs_fs_info *fs_info)
1082 {
1083 	return 0;
1084 }
1085 #endif
1086 
1087 #endif
1088