xref: /linux/fs/bcachefs/bcachefs.h (revision 40ccd6aa3e2e05be93394e3cd560c718dedfcc77)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _BCACHEFS_H
3 #define _BCACHEFS_H
4 
5 /*
6  * SOME HIGH LEVEL CODE DOCUMENTATION:
7  *
8  * Bcache mostly works with cache sets, cache devices, and backing devices.
9  *
10  * Support for multiple cache devices hasn't quite been finished off yet, but
11  * it's about 95% plumbed through. A cache set and its cache devices is sort of
12  * like a md raid array and its component devices. Most of the code doesn't care
13  * about individual cache devices, the main abstraction is the cache set.
14  *
15  * Multiple cache devices is intended to give us the ability to mirror dirty
16  * cached data and metadata, without mirroring clean cached data.
17  *
18  * Backing devices are different, in that they have a lifetime independent of a
19  * cache set. When you register a newly formatted backing device it'll come up
20  * in passthrough mode, and then you can attach and detach a backing device from
21  * a cache set at runtime - while it's mounted and in use. Detaching implicitly
22  * invalidates any cached data for that backing device.
23  *
24  * A cache set can have multiple (many) backing devices attached to it.
25  *
26  * There's also flash only volumes - this is the reason for the distinction
27  * between struct cached_dev and struct bcache_device. A flash only volume
28  * works much like a bcache device that has a backing device, except the
29  * "cached" data is always dirty. The end result is that we get thin
30  * provisioning with very little additional code.
31  *
32  * Flash only volumes work but they're not production ready because the moving
33  * garbage collector needs more work. More on that later.
34  *
35  * BUCKETS/ALLOCATION:
36  *
37  * Bcache is primarily designed for caching, which means that in normal
38  * operation all of our available space will be allocated. Thus, we need an
39  * efficient way of deleting things from the cache so we can write new things to
40  * it.
41  *
42  * To do this, we first divide the cache device up into buckets. A bucket is the
43  * unit of allocation; they're typically around 1 mb - anywhere from 128k to 2M+
44  * works efficiently.
45  *
46  * Each bucket has a 16 bit priority, and an 8 bit generation associated with
47  * it. The gens and priorities for all the buckets are stored contiguously and
48  * packed on disk (in a linked list of buckets - aside from the superblock, all
49  * of bcache's metadata is stored in buckets).
50  *
51  * The priority is used to implement an LRU. We reset a bucket's priority when
52  * we allocate it or on cache it, and every so often we decrement the priority
53  * of each bucket. It could be used to implement something more sophisticated,
54  * if anyone ever gets around to it.
55  *
56  * The generation is used for invalidating buckets. Each pointer also has an 8
57  * bit generation embedded in it; for a pointer to be considered valid, its gen
58  * must match the gen of the bucket it points into.  Thus, to reuse a bucket all
59  * we have to do is increment its gen (and write its new gen to disk; we batch
60  * this up).
61  *
62  * Bcache is entirely COW - we never write twice to a bucket, even buckets that
63  * contain metadata (including btree nodes).
64  *
65  * THE BTREE:
66  *
67  * Bcache is in large part design around the btree.
68  *
69  * At a high level, the btree is just an index of key -> ptr tuples.
70  *
71  * Keys represent extents, and thus have a size field. Keys also have a variable
72  * number of pointers attached to them (potentially zero, which is handy for
73  * invalidating the cache).
74  *
75  * The key itself is an inode:offset pair. The inode number corresponds to a
76  * backing device or a flash only volume. The offset is the ending offset of the
77  * extent within the inode - not the starting offset; this makes lookups
78  * slightly more convenient.
79  *
80  * Pointers contain the cache device id, the offset on that device, and an 8 bit
81  * generation number. More on the gen later.
82  *
83  * Index lookups are not fully abstracted - cache lookups in particular are
84  * still somewhat mixed in with the btree code, but things are headed in that
85  * direction.
86  *
87  * Updates are fairly well abstracted, though. There are two different ways of
88  * updating the btree; insert and replace.
89  *
90  * BTREE_INSERT will just take a list of keys and insert them into the btree -
91  * overwriting (possibly only partially) any extents they overlap with. This is
92  * used to update the index after a write.
93  *
94  * BTREE_REPLACE is really cmpxchg(); it inserts a key into the btree iff it is
95  * overwriting a key that matches another given key. This is used for inserting
96  * data into the cache after a cache miss, and for background writeback, and for
97  * the moving garbage collector.
98  *
99  * There is no "delete" operation; deleting things from the index is
100  * accomplished by either by invalidating pointers (by incrementing a bucket's
101  * gen) or by inserting a key with 0 pointers - which will overwrite anything
102  * previously present at that location in the index.
103  *
104  * This means that there are always stale/invalid keys in the btree. They're
105  * filtered out by the code that iterates through a btree node, and removed when
106  * a btree node is rewritten.
107  *
108  * BTREE NODES:
109  *
110  * Our unit of allocation is a bucket, and we can't arbitrarily allocate and
111  * free smaller than a bucket - so, that's how big our btree nodes are.
112  *
113  * (If buckets are really big we'll only use part of the bucket for a btree node
114  * - no less than 1/4th - but a bucket still contains no more than a single
115  * btree node. I'd actually like to change this, but for now we rely on the
116  * bucket's gen for deleting btree nodes when we rewrite/split a node.)
117  *
118  * Anyways, btree nodes are big - big enough to be inefficient with a textbook
119  * btree implementation.
120  *
121  * The way this is solved is that btree nodes are internally log structured; we
122  * can append new keys to an existing btree node without rewriting it. This
123  * means each set of keys we write is sorted, but the node is not.
124  *
125  * We maintain this log structure in memory - keeping 1Mb of keys sorted would
126  * be expensive, and we have to distinguish between the keys we have written and
127  * the keys we haven't. So to do a lookup in a btree node, we have to search
128  * each sorted set. But we do merge written sets together lazily, so the cost of
129  * these extra searches is quite low (normally most of the keys in a btree node
130  * will be in one big set, and then there'll be one or two sets that are much
131  * smaller).
132  *
133  * This log structure makes bcache's btree more of a hybrid between a
134  * conventional btree and a compacting data structure, with some of the
135  * advantages of both.
136  *
137  * GARBAGE COLLECTION:
138  *
139  * We can't just invalidate any bucket - it might contain dirty data or
140  * metadata. If it once contained dirty data, other writes might overwrite it
141  * later, leaving no valid pointers into that bucket in the index.
142  *
143  * Thus, the primary purpose of garbage collection is to find buckets to reuse.
144  * It also counts how much valid data it each bucket currently contains, so that
145  * allocation can reuse buckets sooner when they've been mostly overwritten.
146  *
147  * It also does some things that are really internal to the btree
148  * implementation. If a btree node contains pointers that are stale by more than
149  * some threshold, it rewrites the btree node to avoid the bucket's generation
150  * wrapping around. It also merges adjacent btree nodes if they're empty enough.
151  *
152  * THE JOURNAL:
153  *
154  * Bcache's journal is not necessary for consistency; we always strictly
155  * order metadata writes so that the btree and everything else is consistent on
156  * disk in the event of an unclean shutdown, and in fact bcache had writeback
157  * caching (with recovery from unclean shutdown) before journalling was
158  * implemented.
159  *
160  * Rather, the journal is purely a performance optimization; we can't complete a
161  * write until we've updated the index on disk, otherwise the cache would be
162  * inconsistent in the event of an unclean shutdown. This means that without the
163  * journal, on random write workloads we constantly have to update all the leaf
164  * nodes in the btree, and those writes will be mostly empty (appending at most
165  * a few keys each) - highly inefficient in terms of amount of metadata writes,
166  * and it puts more strain on the various btree resorting/compacting code.
167  *
168  * The journal is just a log of keys we've inserted; on startup we just reinsert
169  * all the keys in the open journal entries. That means that when we're updating
170  * a node in the btree, we can wait until a 4k block of keys fills up before
171  * writing them out.
172  *
173  * For simplicity, we only journal updates to leaf nodes; updates to parent
174  * nodes are rare enough (since our leaf nodes are huge) that it wasn't worth
175  * the complexity to deal with journalling them (in particular, journal replay)
176  * - updates to non leaf nodes just happen synchronously (see btree_split()).
177  */
178 
179 #undef pr_fmt
180 #ifdef __KERNEL__
181 #define pr_fmt(fmt) "bcachefs: %s() " fmt "\n", __func__
182 #else
183 #define pr_fmt(fmt) "%s() " fmt "\n", __func__
184 #endif
185 
186 #include <linux/backing-dev-defs.h>
187 #include <linux/bug.h>
188 #include <linux/bio.h>
189 #include <linux/closure.h>
190 #include <linux/kobject.h>
191 #include <linux/list.h>
192 #include <linux/math64.h>
193 #include <linux/mutex.h>
194 #include <linux/percpu-refcount.h>
195 #include <linux/percpu-rwsem.h>
196 #include <linux/refcount.h>
197 #include <linux/rhashtable.h>
198 #include <linux/rwsem.h>
199 #include <linux/semaphore.h>
200 #include <linux/seqlock.h>
201 #include <linux/shrinker.h>
202 #include <linux/srcu.h>
203 #include <linux/types.h>
204 #include <linux/workqueue.h>
205 #include <linux/zstd.h>
206 
207 #include "bcachefs_format.h"
208 #include "errcode.h"
209 #include "fifo.h"
210 #include "nocow_locking_types.h"
211 #include "opts.h"
212 #include "recovery_passes_types.h"
213 #include "sb-errors_types.h"
214 #include "seqmutex.h"
215 #include "time_stats.h"
216 #include "util.h"
217 
218 #ifdef CONFIG_BCACHEFS_DEBUG
219 #define BCH_WRITE_REF_DEBUG
220 #endif
221 
222 #ifndef dynamic_fault
223 #define dynamic_fault(...)		0
224 #endif
225 
226 #define race_fault(...)			dynamic_fault("bcachefs:race")
227 
228 #define count_event(_c, _name)	this_cpu_inc((_c)->counters[BCH_COUNTER_##_name])
229 
230 #define trace_and_count(_c, _name, ...)					\
231 do {									\
232 	count_event(_c, _name);						\
233 	trace_##_name(__VA_ARGS__);					\
234 } while (0)
235 
236 #define bch2_fs_init_fault(name)					\
237 	dynamic_fault("bcachefs:bch_fs_init:" name)
238 #define bch2_meta_read_fault(name)					\
239 	 dynamic_fault("bcachefs:meta:read:" name)
240 #define bch2_meta_write_fault(name)					\
241 	 dynamic_fault("bcachefs:meta:write:" name)
242 
243 #ifdef __KERNEL__
244 #define BCACHEFS_LOG_PREFIX
245 #endif
246 
247 #ifdef BCACHEFS_LOG_PREFIX
248 
249 #define bch2_log_msg(_c, fmt)			"bcachefs (%s): " fmt, ((_c)->name)
250 #define bch2_fmt_dev(_ca, fmt)			"bcachefs (%s): " fmt "\n", ((_ca)->name)
251 #define bch2_fmt_dev_offset(_ca, _offset, fmt)	"bcachefs (%s sector %llu): " fmt "\n", ((_ca)->name), (_offset)
252 #define bch2_fmt_inum(_c, _inum, fmt)		"bcachefs (%s inum %llu): " fmt "\n", ((_c)->name), (_inum)
253 #define bch2_fmt_inum_offset(_c, _inum, _offset, fmt)			\
254 	 "bcachefs (%s inum %llu offset %llu): " fmt "\n", ((_c)->name), (_inum), (_offset)
255 
256 #else
257 
258 #define bch2_log_msg(_c, fmt)			fmt
259 #define bch2_fmt_dev(_ca, fmt)			"%s: " fmt "\n", ((_ca)->name)
260 #define bch2_fmt_dev_offset(_ca, _offset, fmt)	"%s sector %llu: " fmt "\n", ((_ca)->name), (_offset)
261 #define bch2_fmt_inum(_c, _inum, fmt)		"inum %llu: " fmt "\n", (_inum)
262 #define bch2_fmt_inum_offset(_c, _inum, _offset, fmt)				\
263 	 "inum %llu offset %llu: " fmt "\n", (_inum), (_offset)
264 
265 #endif
266 
267 #define bch2_fmt(_c, fmt)		bch2_log_msg(_c, fmt "\n")
268 
269 __printf(2, 3)
270 void bch2_print_opts(struct bch_opts *, const char *, ...);
271 
272 __printf(2, 3)
273 void __bch2_print(struct bch_fs *c, const char *fmt, ...);
274 
275 #define maybe_dev_to_fs(_c)	_Generic((_c),				\
276 	struct bch_dev *:	((struct bch_dev *) (_c))->fs,		\
277 	struct bch_fs *:	(_c))
278 
279 #define bch2_print(_c, ...) __bch2_print(maybe_dev_to_fs(_c), __VA_ARGS__)
280 
281 #define bch2_print_ratelimited(_c, ...)					\
282 do {									\
283 	static DEFINE_RATELIMIT_STATE(_rs,				\
284 				      DEFAULT_RATELIMIT_INTERVAL,	\
285 				      DEFAULT_RATELIMIT_BURST);		\
286 									\
287 	if (__ratelimit(&_rs))						\
288 		bch2_print(_c, __VA_ARGS__);				\
289 } while (0)
290 
291 #define bch_info(c, fmt, ...) \
292 	bch2_print(c, KERN_INFO bch2_fmt(c, fmt), ##__VA_ARGS__)
293 #define bch_notice(c, fmt, ...) \
294 	bch2_print(c, KERN_NOTICE bch2_fmt(c, fmt), ##__VA_ARGS__)
295 #define bch_warn(c, fmt, ...) \
296 	bch2_print(c, KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__)
297 #define bch_warn_ratelimited(c, fmt, ...) \
298 	bch2_print_ratelimited(c, KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__)
299 
300 #define bch_err(c, fmt, ...) \
301 	bch2_print(c, KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__)
302 #define bch_err_dev(ca, fmt, ...) \
303 	bch2_print(c, KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__)
304 #define bch_err_dev_offset(ca, _offset, fmt, ...) \
305 	bch2_print(c, KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__)
306 #define bch_err_inum(c, _inum, fmt, ...) \
307 	bch2_print(c, KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__)
308 #define bch_err_inum_offset(c, _inum, _offset, fmt, ...) \
309 	bch2_print(c, KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__)
310 
311 #define bch_err_ratelimited(c, fmt, ...) \
312 	bch2_print_ratelimited(c, KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__)
313 #define bch_err_dev_ratelimited(ca, fmt, ...) \
314 	bch2_print_ratelimited(ca, KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__)
315 #define bch_err_dev_offset_ratelimited(ca, _offset, fmt, ...) \
316 	bch2_print_ratelimited(ca, KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__)
317 #define bch_err_inum_ratelimited(c, _inum, fmt, ...) \
318 	bch2_print_ratelimited(c, KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__)
319 #define bch_err_inum_offset_ratelimited(c, _inum, _offset, fmt, ...) \
320 	bch2_print_ratelimited(c, KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__)
321 
322 static inline bool should_print_err(int err)
323 {
324 	return err && !bch2_err_matches(err, BCH_ERR_transaction_restart);
325 }
326 
327 #define bch_err_fn(_c, _ret)						\
328 do {									\
329 	if (should_print_err(_ret))					\
330 		bch_err(_c, "%s(): error %s", __func__, bch2_err_str(_ret));\
331 } while (0)
332 
333 #define bch_err_fn_ratelimited(_c, _ret)				\
334 do {									\
335 	if (should_print_err(_ret))					\
336 		bch_err_ratelimited(_c, "%s(): error %s", __func__, bch2_err_str(_ret));\
337 } while (0)
338 
339 #define bch_err_msg(_c, _ret, _msg, ...)				\
340 do {									\
341 	if (should_print_err(_ret))					\
342 		bch_err(_c, "%s(): error " _msg " %s", __func__,	\
343 			##__VA_ARGS__, bch2_err_str(_ret));		\
344 } while (0)
345 
346 #define bch_verbose(c, fmt, ...)					\
347 do {									\
348 	if ((c)->opts.verbose)						\
349 		bch_info(c, fmt, ##__VA_ARGS__);			\
350 } while (0)
351 
352 #define pr_verbose_init(opts, fmt, ...)					\
353 do {									\
354 	if (opt_get(opts, verbose))					\
355 		pr_info(fmt, ##__VA_ARGS__);				\
356 } while (0)
357 
358 /* Parameters that are useful for debugging, but should always be compiled in: */
359 #define BCH_DEBUG_PARAMS_ALWAYS()					\
360 	BCH_DEBUG_PARAM(key_merging_disabled,				\
361 		"Disables merging of extents")				\
362 	BCH_DEBUG_PARAM(btree_node_merging_disabled,			\
363 		"Disables merging of btree nodes")			\
364 	BCH_DEBUG_PARAM(btree_gc_always_rewrite,			\
365 		"Causes mark and sweep to compact and rewrite every "	\
366 		"btree node it traverses")				\
367 	BCH_DEBUG_PARAM(btree_gc_rewrite_disabled,			\
368 		"Disables rewriting of btree nodes during mark and sweep")\
369 	BCH_DEBUG_PARAM(btree_shrinker_disabled,			\
370 		"Disables the shrinker callback for the btree node cache")\
371 	BCH_DEBUG_PARAM(verify_btree_ondisk,				\
372 		"Reread btree nodes at various points to verify the "	\
373 		"mergesort in the read path against modifications "	\
374 		"done in memory")					\
375 	BCH_DEBUG_PARAM(verify_all_btree_replicas,			\
376 		"When reading btree nodes, read all replicas and "	\
377 		"compare them")						\
378 	BCH_DEBUG_PARAM(backpointers_no_use_write_buffer,		\
379 		"Don't use the write buffer for backpointers, enabling "\
380 		"extra runtime checks")
381 
382 /* Parameters that should only be compiled in debug mode: */
383 #define BCH_DEBUG_PARAMS_DEBUG()					\
384 	BCH_DEBUG_PARAM(expensive_debug_checks,				\
385 		"Enables various runtime debugging checks that "	\
386 		"significantly affect performance")			\
387 	BCH_DEBUG_PARAM(debug_check_iterators,				\
388 		"Enables extra verification for btree iterators")	\
389 	BCH_DEBUG_PARAM(debug_check_btree_accounting,			\
390 		"Verify btree accounting for keys within a node")	\
391 	BCH_DEBUG_PARAM(journal_seq_verify,				\
392 		"Store the journal sequence number in the version "	\
393 		"number of every btree key, and verify that btree "	\
394 		"update ordering is preserved during recovery")		\
395 	BCH_DEBUG_PARAM(inject_invalid_keys,				\
396 		"Store the journal sequence number in the version "	\
397 		"number of every btree key, and verify that btree "	\
398 		"update ordering is preserved during recovery")		\
399 	BCH_DEBUG_PARAM(test_alloc_startup,				\
400 		"Force allocator startup to use the slowpath where it"	\
401 		"can't find enough free buckets without invalidating"	\
402 		"cached data")						\
403 	BCH_DEBUG_PARAM(force_reconstruct_read,				\
404 		"Force reads to use the reconstruct path, when reading"	\
405 		"from erasure coded extents")				\
406 	BCH_DEBUG_PARAM(test_restart_gc,				\
407 		"Test restarting mark and sweep gc when bucket gens change")
408 
409 #define BCH_DEBUG_PARAMS_ALL() BCH_DEBUG_PARAMS_ALWAYS() BCH_DEBUG_PARAMS_DEBUG()
410 
411 #ifdef CONFIG_BCACHEFS_DEBUG
412 #define BCH_DEBUG_PARAMS() BCH_DEBUG_PARAMS_ALL()
413 #else
414 #define BCH_DEBUG_PARAMS() BCH_DEBUG_PARAMS_ALWAYS()
415 #endif
416 
417 #define BCH_DEBUG_PARAM(name, description) extern bool bch2_##name;
418 BCH_DEBUG_PARAMS()
419 #undef BCH_DEBUG_PARAM
420 
421 #ifndef CONFIG_BCACHEFS_DEBUG
422 #define BCH_DEBUG_PARAM(name, description) static const __maybe_unused bool bch2_##name;
423 BCH_DEBUG_PARAMS_DEBUG()
424 #undef BCH_DEBUG_PARAM
425 #endif
426 
427 #define BCH_TIME_STATS()			\
428 	x(btree_node_mem_alloc)			\
429 	x(btree_node_split)			\
430 	x(btree_node_compact)			\
431 	x(btree_node_merge)			\
432 	x(btree_node_sort)			\
433 	x(btree_node_read)			\
434 	x(btree_node_read_done)			\
435 	x(btree_interior_update_foreground)	\
436 	x(btree_interior_update_total)		\
437 	x(btree_gc)				\
438 	x(data_write)				\
439 	x(data_read)				\
440 	x(data_promote)				\
441 	x(journal_flush_write)			\
442 	x(journal_noflush_write)		\
443 	x(journal_flush_seq)			\
444 	x(blocked_journal_low_on_space)		\
445 	x(blocked_journal_low_on_pin)		\
446 	x(blocked_journal_max_in_flight)	\
447 	x(blocked_allocate)			\
448 	x(blocked_allocate_open_bucket)		\
449 	x(blocked_write_buffer_full)		\
450 	x(nocow_lock_contended)
451 
452 enum bch_time_stats {
453 #define x(name) BCH_TIME_##name,
454 	BCH_TIME_STATS()
455 #undef x
456 	BCH_TIME_STAT_NR
457 };
458 
459 #include "alloc_types.h"
460 #include "btree_types.h"
461 #include "btree_node_scan_types.h"
462 #include "btree_write_buffer_types.h"
463 #include "buckets_types.h"
464 #include "buckets_waiting_for_journal_types.h"
465 #include "clock_types.h"
466 #include "disk_groups_types.h"
467 #include "ec_types.h"
468 #include "journal_types.h"
469 #include "keylist_types.h"
470 #include "quota_types.h"
471 #include "rebalance_types.h"
472 #include "replicas_types.h"
473 #include "sb-members_types.h"
474 #include "subvolume_types.h"
475 #include "super_types.h"
476 #include "thread_with_file_types.h"
477 
478 /* Number of nodes btree coalesce will try to coalesce at once */
479 #define GC_MERGE_NODES		4U
480 
481 /* Maximum number of nodes we might need to allocate atomically: */
482 #define BTREE_RESERVE_MAX	(BTREE_MAX_DEPTH + (BTREE_MAX_DEPTH - 1))
483 
484 /* Size of the freelist we allocate btree nodes from: */
485 #define BTREE_NODE_RESERVE	(BTREE_RESERVE_MAX * 4)
486 
487 #define BTREE_NODE_OPEN_BUCKET_RESERVE	(BTREE_RESERVE_MAX * BCH_REPLICAS_MAX)
488 
489 struct btree;
490 
491 enum gc_phase {
492 	GC_PHASE_NOT_RUNNING,
493 	GC_PHASE_START,
494 	GC_PHASE_SB,
495 
496 	GC_PHASE_BTREE_stripes,
497 	GC_PHASE_BTREE_extents,
498 	GC_PHASE_BTREE_inodes,
499 	GC_PHASE_BTREE_dirents,
500 	GC_PHASE_BTREE_xattrs,
501 	GC_PHASE_BTREE_alloc,
502 	GC_PHASE_BTREE_quotas,
503 	GC_PHASE_BTREE_reflink,
504 	GC_PHASE_BTREE_subvolumes,
505 	GC_PHASE_BTREE_snapshots,
506 	GC_PHASE_BTREE_lru,
507 	GC_PHASE_BTREE_freespace,
508 	GC_PHASE_BTREE_need_discard,
509 	GC_PHASE_BTREE_backpointers,
510 	GC_PHASE_BTREE_bucket_gens,
511 	GC_PHASE_BTREE_snapshot_trees,
512 	GC_PHASE_BTREE_deleted_inodes,
513 	GC_PHASE_BTREE_logged_ops,
514 	GC_PHASE_BTREE_rebalance_work,
515 	GC_PHASE_BTREE_subvolume_children,
516 
517 	GC_PHASE_PENDING_DELETE,
518 };
519 
520 struct gc_pos {
521 	enum gc_phase		phase;
522 	u16			level;
523 	struct bpos		pos;
524 };
525 
526 struct reflink_gc {
527 	u64		offset;
528 	u32		size;
529 	u32		refcount;
530 };
531 
532 typedef GENRADIX(struct reflink_gc) reflink_gc_table;
533 
534 struct io_count {
535 	u64			sectors[2][BCH_DATA_NR];
536 };
537 
538 struct bch_dev {
539 	struct kobject		kobj;
540 #ifdef CONFIG_BCACHEFS_DEBUG
541 	atomic_long_t		ref;
542 	bool			dying;
543 	unsigned long		last_put;
544 #else
545 	struct percpu_ref	ref;
546 #endif
547 	struct completion	ref_completion;
548 	struct percpu_ref	io_ref;
549 	struct completion	io_ref_completion;
550 
551 	struct bch_fs		*fs;
552 
553 	u8			dev_idx;
554 	/*
555 	 * Cached version of this device's member info from superblock
556 	 * Committed by bch2_write_super() -> bch_fs_mi_update()
557 	 */
558 	struct bch_member_cpu	mi;
559 	atomic64_t		errors[BCH_MEMBER_ERROR_NR];
560 
561 	__uuid_t		uuid;
562 	char			name[BDEVNAME_SIZE];
563 
564 	struct bch_sb_handle	disk_sb;
565 	struct bch_sb		*sb_read_scratch;
566 	int			sb_write_error;
567 	dev_t			dev;
568 	atomic_t		flush_seq;
569 
570 	struct bch_devs_mask	self;
571 
572 	/*
573 	 * Buckets:
574 	 * Per-bucket arrays are protected by c->mark_lock, bucket_lock and
575 	 * gc_lock, for device resize - holding any is sufficient for access:
576 	 * Or rcu_read_lock(), but only for dev_ptr_stale():
577 	 */
578 	struct bucket_array __rcu *buckets_gc;
579 	struct bucket_gens __rcu *bucket_gens;
580 	u8			*oldest_gen;
581 	unsigned long		*buckets_nouse;
582 	struct rw_semaphore	bucket_lock;
583 
584 	struct bch_dev_usage		*usage_base;
585 	struct bch_dev_usage __percpu	*usage[JOURNAL_BUF_NR];
586 	struct bch_dev_usage __percpu	*usage_gc;
587 
588 	/* Allocator: */
589 	u64			new_fs_bucket_idx;
590 	u64			alloc_cursor[3];
591 
592 	unsigned		nr_open_buckets;
593 	unsigned		nr_btree_reserve;
594 
595 	size_t			inc_gen_needs_gc;
596 	size_t			inc_gen_really_needs_gc;
597 	size_t			buckets_waiting_on_journal;
598 
599 	atomic64_t		rebalance_work;
600 
601 	struct journal_device	journal;
602 	u64			prev_journal_sector;
603 
604 	struct work_struct	io_error_work;
605 
606 	/* The rest of this all shows up in sysfs */
607 	atomic64_t		cur_latency[2];
608 	struct bch2_time_stats_quantiles io_latency[2];
609 
610 #define CONGESTED_MAX		1024
611 	atomic_t		congested;
612 	u64			congested_last;
613 
614 	struct io_count __percpu *io_done;
615 };
616 
617 /*
618  * initial_gc_unfixed
619  * error
620  * topology error
621  */
622 
623 #define BCH_FS_FLAGS()			\
624 	x(new_fs)			\
625 	x(started)			\
626 	x(may_go_rw)			\
627 	x(rw)				\
628 	x(was_rw)			\
629 	x(stopping)			\
630 	x(emergency_ro)			\
631 	x(going_ro)			\
632 	x(write_disable_complete)	\
633 	x(clean_shutdown)		\
634 	x(fsck_running)			\
635 	x(initial_gc_unfixed)		\
636 	x(need_delete_dead_snapshots)	\
637 	x(error)			\
638 	x(topology_error)		\
639 	x(errors_fixed)			\
640 	x(errors_not_fixed)		\
641 	x(no_invalid_checks)
642 
643 enum bch_fs_flags {
644 #define x(n)		BCH_FS_##n,
645 	BCH_FS_FLAGS()
646 #undef x
647 };
648 
649 struct btree_debug {
650 	unsigned		id;
651 };
652 
653 #define BCH_TRANSACTIONS_NR 128
654 
655 struct btree_transaction_stats {
656 	struct bch2_time_stats	duration;
657 	struct bch2_time_stats	lock_hold_times;
658 	struct mutex		lock;
659 	unsigned		nr_max_paths;
660 	unsigned		journal_entries_size;
661 	unsigned		max_mem;
662 	char			*max_paths_text;
663 };
664 
665 struct bch_fs_pcpu {
666 	u64			sectors_available;
667 };
668 
669 struct journal_seq_blacklist_table {
670 	size_t			nr;
671 	struct journal_seq_blacklist_table_entry {
672 		u64		start;
673 		u64		end;
674 		bool		dirty;
675 	}			entries[];
676 };
677 
678 struct journal_keys {
679 	/* must match layout in darray_types.h */
680 	size_t			nr, size;
681 	struct journal_key {
682 		u64		journal_seq;
683 		u32		journal_offset;
684 		enum btree_id	btree_id:8;
685 		unsigned	level:8;
686 		bool		allocated;
687 		bool		overwritten;
688 		struct bkey_i	*k;
689 	}			*data;
690 	/*
691 	 * Gap buffer: instead of all the empty space in the array being at the
692 	 * end of the buffer - from @nr to @size - the empty space is at @gap.
693 	 * This means that sequential insertions are O(n) instead of O(n^2).
694 	 */
695 	size_t			gap;
696 	atomic_t		ref;
697 	bool			initial_ref_held;
698 };
699 
700 struct btree_trans_buf {
701 	struct btree_trans	*trans;
702 };
703 
704 #define REPLICAS_DELTA_LIST_MAX	(1U << 16)
705 
706 #define BCACHEFS_ROOT_SUBVOL_INUM					\
707 	((subvol_inum) { BCACHEFS_ROOT_SUBVOL,	BCACHEFS_ROOT_INO })
708 
709 #define BCH_WRITE_REFS()						\
710 	x(trans)							\
711 	x(write)							\
712 	x(promote)							\
713 	x(node_rewrite)							\
714 	x(stripe_create)						\
715 	x(stripe_delete)						\
716 	x(reflink)							\
717 	x(fallocate)							\
718 	x(fsync)							\
719 	x(dio_write)							\
720 	x(discard)							\
721 	x(discard_fast)							\
722 	x(invalidate)							\
723 	x(delete_dead_snapshots)					\
724 	x(gc_gens)							\
725 	x(snapshot_delete_pagecache)					\
726 	x(sysfs)							\
727 	x(btree_write_buffer)
728 
729 enum bch_write_ref {
730 #define x(n) BCH_WRITE_REF_##n,
731 	BCH_WRITE_REFS()
732 #undef x
733 	BCH_WRITE_REF_NR,
734 };
735 
736 struct bch_fs {
737 	struct closure		cl;
738 
739 	struct list_head	list;
740 	struct kobject		kobj;
741 	struct kobject		counters_kobj;
742 	struct kobject		internal;
743 	struct kobject		opts_dir;
744 	struct kobject		time_stats;
745 	unsigned long		flags;
746 
747 	int			minor;
748 	struct device		*chardev;
749 	struct super_block	*vfs_sb;
750 	dev_t			dev;
751 	char			name[40];
752 	struct stdio_redirect	*stdio;
753 	struct task_struct	*stdio_filter;
754 
755 	/* ro/rw, add/remove/resize devices: */
756 	struct rw_semaphore	state_lock;
757 
758 	/* Counts outstanding writes, for clean transition to read-only */
759 #ifdef BCH_WRITE_REF_DEBUG
760 	atomic_long_t		writes[BCH_WRITE_REF_NR];
761 #else
762 	struct percpu_ref	writes;
763 #endif
764 	/*
765 	 * Analagous to c->writes, for asynchronous ops that don't necessarily
766 	 * need fs to be read-write
767 	 */
768 	refcount_t		ro_ref;
769 	wait_queue_head_t	ro_ref_wait;
770 
771 	struct work_struct	read_only_work;
772 
773 	struct bch_dev __rcu	*devs[BCH_SB_MEMBERS_MAX];
774 
775 	struct bch_replicas_cpu replicas;
776 	struct bch_replicas_cpu replicas_gc;
777 	struct mutex		replicas_gc_lock;
778 	mempool_t		replicas_delta_pool;
779 
780 	struct journal_entry_res btree_root_journal_res;
781 	struct journal_entry_res replicas_journal_res;
782 	struct journal_entry_res clock_journal_res;
783 	struct journal_entry_res dev_usage_journal_res;
784 
785 	struct bch_disk_groups_cpu __rcu *disk_groups;
786 
787 	struct bch_opts		opts;
788 
789 	/* Updated by bch2_sb_update():*/
790 	struct {
791 		__uuid_t	uuid;
792 		__uuid_t	user_uuid;
793 
794 		u16		version;
795 		u16		version_min;
796 		u16		version_upgrade_complete;
797 
798 		u8		nr_devices;
799 		u8		clean;
800 
801 		u8		encryption_type;
802 
803 		u64		time_base_lo;
804 		u32		time_base_hi;
805 		unsigned	time_units_per_sec;
806 		unsigned	nsec_per_time_unit;
807 		u64		features;
808 		u64		compat;
809 		unsigned long	errors_silent[BITS_TO_LONGS(BCH_SB_ERR_MAX)];
810 		u64		btrees_lost_data;
811 	}			sb;
812 
813 
814 	struct bch_sb_handle	disk_sb;
815 
816 	unsigned short		block_bits;	/* ilog2(block_size) */
817 
818 	u16			btree_foreground_merge_threshold;
819 
820 	struct closure		sb_write;
821 	struct mutex		sb_lock;
822 
823 	/* snapshot.c: */
824 	struct snapshot_table __rcu *snapshots;
825 	struct mutex		snapshot_table_lock;
826 	struct rw_semaphore	snapshot_create_lock;
827 
828 	struct work_struct	snapshot_delete_work;
829 	struct work_struct	snapshot_wait_for_pagecache_and_delete_work;
830 	snapshot_id_list	snapshots_unlinked;
831 	struct mutex		snapshots_unlinked_lock;
832 
833 	/* BTREE CACHE */
834 	struct bio_set		btree_bio;
835 	struct workqueue_struct	*io_complete_wq;
836 
837 	struct btree_root	btree_roots_known[BTREE_ID_NR];
838 	DARRAY(struct btree_root) btree_roots_extra;
839 	struct mutex		btree_root_lock;
840 
841 	struct btree_cache	btree_cache;
842 
843 	/*
844 	 * Cache of allocated btree nodes - if we allocate a btree node and
845 	 * don't use it, if we free it that space can't be reused until going
846 	 * _all_ the way through the allocator (which exposes us to a livelock
847 	 * when allocating btree reserves fail halfway through) - instead, we
848 	 * can stick them here:
849 	 */
850 	struct btree_alloc	btree_reserve_cache[BTREE_NODE_RESERVE * 2];
851 	unsigned		btree_reserve_cache_nr;
852 	struct mutex		btree_reserve_cache_lock;
853 
854 	mempool_t		btree_interior_update_pool;
855 	struct list_head	btree_interior_update_list;
856 	struct list_head	btree_interior_updates_unwritten;
857 	struct mutex		btree_interior_update_lock;
858 	struct closure_waitlist	btree_interior_update_wait;
859 
860 	struct workqueue_struct	*btree_interior_update_worker;
861 	struct work_struct	btree_interior_update_work;
862 
863 	struct workqueue_struct	*btree_node_rewrite_worker;
864 
865 	struct list_head	pending_node_rewrites;
866 	struct mutex		pending_node_rewrites_lock;
867 
868 	/* btree_io.c: */
869 	spinlock_t		btree_write_error_lock;
870 	struct btree_write_stats {
871 		atomic64_t	nr;
872 		atomic64_t	bytes;
873 	}			btree_write_stats[BTREE_WRITE_TYPE_NR];
874 
875 	/* btree_iter.c: */
876 	struct seqmutex		btree_trans_lock;
877 	struct list_head	btree_trans_list;
878 	mempool_t		btree_trans_pool;
879 	mempool_t		btree_trans_mem_pool;
880 	struct btree_trans_buf  __percpu	*btree_trans_bufs;
881 
882 	struct srcu_struct	btree_trans_barrier;
883 	bool			btree_trans_barrier_initialized;
884 
885 	struct btree_key_cache	btree_key_cache;
886 	unsigned		btree_key_cache_btrees;
887 
888 	struct btree_write_buffer btree_write_buffer;
889 
890 	struct workqueue_struct	*btree_update_wq;
891 	struct workqueue_struct	*btree_io_complete_wq;
892 	/* copygc needs its own workqueue for index updates.. */
893 	struct workqueue_struct	*copygc_wq;
894 	/*
895 	 * Use a dedicated wq for write ref holder tasks. Required to avoid
896 	 * dependency problems with other wq tasks that can block on ref
897 	 * draining, such as read-only transition.
898 	 */
899 	struct workqueue_struct *write_ref_wq;
900 
901 	/* ALLOCATION */
902 	struct bch_devs_mask	rw_devs[BCH_DATA_NR];
903 
904 	u64			capacity; /* sectors */
905 
906 	/*
907 	 * When capacity _decreases_ (due to a disk being removed), we
908 	 * increment capacity_gen - this invalidates outstanding reservations
909 	 * and forces them to be revalidated
910 	 */
911 	u32			capacity_gen;
912 	unsigned		bucket_size_max;
913 
914 	atomic64_t		sectors_available;
915 	struct mutex		sectors_available_lock;
916 
917 	struct bch_fs_pcpu __percpu	*pcpu;
918 
919 	struct percpu_rw_semaphore	mark_lock;
920 
921 	seqcount_t			usage_lock;
922 	struct bch_fs_usage		*usage_base;
923 	struct bch_fs_usage __percpu	*usage[JOURNAL_BUF_NR];
924 	struct bch_fs_usage __percpu	*usage_gc;
925 	u64 __percpu		*online_reserved;
926 
927 	/* single element mempool: */
928 	struct mutex		usage_scratch_lock;
929 	struct bch_fs_usage_online *usage_scratch;
930 
931 	struct io_clock		io_clock[2];
932 
933 	/* JOURNAL SEQ BLACKLIST */
934 	struct journal_seq_blacklist_table *
935 				journal_seq_blacklist_table;
936 
937 	/* ALLOCATOR */
938 	spinlock_t		freelist_lock;
939 	struct closure_waitlist	freelist_wait;
940 
941 	open_bucket_idx_t	open_buckets_freelist;
942 	open_bucket_idx_t	open_buckets_nr_free;
943 	struct closure_waitlist	open_buckets_wait;
944 	struct open_bucket	open_buckets[OPEN_BUCKETS_COUNT];
945 	open_bucket_idx_t	open_buckets_hash[OPEN_BUCKETS_COUNT];
946 
947 	open_bucket_idx_t	open_buckets_partial[OPEN_BUCKETS_COUNT];
948 	open_bucket_idx_t	open_buckets_partial_nr;
949 
950 	struct write_point	btree_write_point;
951 	struct write_point	rebalance_write_point;
952 
953 	struct write_point	write_points[WRITE_POINT_MAX];
954 	struct hlist_head	write_points_hash[WRITE_POINT_HASH_NR];
955 	struct mutex		write_points_hash_lock;
956 	unsigned		write_points_nr;
957 
958 	struct buckets_waiting_for_journal buckets_waiting_for_journal;
959 	struct work_struct	invalidate_work;
960 	struct work_struct	discard_work;
961 	struct mutex		discard_buckets_in_flight_lock;
962 	DARRAY(struct bpos)	discard_buckets_in_flight;
963 	struct work_struct	discard_fast_work;
964 
965 	/* GARBAGE COLLECTION */
966 	struct work_struct	gc_gens_work;
967 	unsigned long		gc_count;
968 
969 	enum btree_id		gc_gens_btree;
970 	struct bpos		gc_gens_pos;
971 
972 	/*
973 	 * Tracks GC's progress - everything in the range [ZERO_KEY..gc_cur_pos]
974 	 * has been marked by GC.
975 	 *
976 	 * gc_cur_phase is a superset of btree_ids (BTREE_ID_extents etc.)
977 	 *
978 	 * Protected by gc_pos_lock. Only written to by GC thread, so GC thread
979 	 * can read without a lock.
980 	 */
981 	seqcount_t		gc_pos_lock;
982 	struct gc_pos		gc_pos;
983 
984 	/*
985 	 * The allocation code needs gc_mark in struct bucket to be correct, but
986 	 * it's not while a gc is in progress.
987 	 */
988 	struct rw_semaphore	gc_lock;
989 	struct mutex		gc_gens_lock;
990 
991 	/* IO PATH */
992 	struct semaphore	io_in_flight;
993 	struct bio_set		bio_read;
994 	struct bio_set		bio_read_split;
995 	struct bio_set		bio_write;
996 	struct bio_set		replica_set;
997 	struct mutex		bio_bounce_pages_lock;
998 	mempool_t		bio_bounce_pages;
999 	struct bucket_nocow_lock_table
1000 				nocow_locks;
1001 	struct rhashtable	promote_table;
1002 
1003 	mempool_t		compression_bounce[2];
1004 	mempool_t		compress_workspace[BCH_COMPRESSION_TYPE_NR];
1005 	mempool_t		decompress_workspace;
1006 	size_t			zstd_workspace_size;
1007 
1008 	struct crypto_shash	*sha256;
1009 	struct crypto_sync_skcipher *chacha20;
1010 	struct crypto_shash	*poly1305;
1011 
1012 	atomic64_t		key_version;
1013 
1014 	mempool_t		large_bkey_pool;
1015 
1016 	/* MOVE.C */
1017 	struct list_head	moving_context_list;
1018 	struct mutex		moving_context_lock;
1019 
1020 	/* REBALANCE */
1021 	struct bch_fs_rebalance	rebalance;
1022 
1023 	/* COPYGC */
1024 	struct task_struct	*copygc_thread;
1025 	struct write_point	copygc_write_point;
1026 	s64			copygc_wait_at;
1027 	s64			copygc_wait;
1028 	bool			copygc_running;
1029 	wait_queue_head_t	copygc_running_wq;
1030 
1031 	/* STRIPES: */
1032 	GENRADIX(struct stripe) stripes;
1033 	GENRADIX(struct gc_stripe) gc_stripes;
1034 
1035 	struct hlist_head	ec_stripes_new[32];
1036 	spinlock_t		ec_stripes_new_lock;
1037 
1038 	ec_stripes_heap		ec_stripes_heap;
1039 	struct mutex		ec_stripes_heap_lock;
1040 
1041 	/* ERASURE CODING */
1042 	struct list_head	ec_stripe_head_list;
1043 	struct mutex		ec_stripe_head_lock;
1044 
1045 	struct list_head	ec_stripe_new_list;
1046 	struct mutex		ec_stripe_new_lock;
1047 	wait_queue_head_t	ec_stripe_new_wait;
1048 
1049 	struct work_struct	ec_stripe_create_work;
1050 	u64			ec_stripe_hint;
1051 
1052 	struct work_struct	ec_stripe_delete_work;
1053 
1054 	struct bio_set		ec_bioset;
1055 
1056 	/* REFLINK */
1057 	reflink_gc_table	reflink_gc_table;
1058 	size_t			reflink_gc_nr;
1059 
1060 	/* fs.c */
1061 	struct list_head	vfs_inodes_list;
1062 	struct mutex		vfs_inodes_lock;
1063 
1064 	/* VFS IO PATH - fs-io.c */
1065 	struct bio_set		writepage_bioset;
1066 	struct bio_set		dio_write_bioset;
1067 	struct bio_set		dio_read_bioset;
1068 	struct bio_set		nocow_flush_bioset;
1069 
1070 	/* QUOTAS */
1071 	struct bch_memquota_type quotas[QTYP_NR];
1072 
1073 	/* RECOVERY */
1074 	u64			journal_replay_seq_start;
1075 	u64			journal_replay_seq_end;
1076 	/*
1077 	 * Two different uses:
1078 	 * "Has this fsck pass?" - i.e. should this type of error be an
1079 	 * emergency read-only
1080 	 * And, in certain situations fsck will rewind to an earlier pass: used
1081 	 * for signaling to the toplevel code which pass we want to run now.
1082 	 */
1083 	enum bch_recovery_pass	curr_recovery_pass;
1084 	/* bitmap of explicitly enabled recovery passes: */
1085 	u64			recovery_passes_explicit;
1086 	/* bitmask of recovery passes that we actually ran */
1087 	u64			recovery_passes_complete;
1088 	/* never rewinds version of curr_recovery_pass */
1089 	enum bch_recovery_pass	recovery_pass_done;
1090 	struct semaphore	online_fsck_mutex;
1091 
1092 	/* DEBUG JUNK */
1093 	struct dentry		*fs_debug_dir;
1094 	struct dentry		*btree_debug_dir;
1095 	struct btree_debug	btree_debug[BTREE_ID_NR];
1096 	struct btree		*verify_data;
1097 	struct btree_node	*verify_ondisk;
1098 	struct mutex		verify_lock;
1099 
1100 	u64			*unused_inode_hints;
1101 	unsigned		inode_shard_bits;
1102 
1103 	/*
1104 	 * A btree node on disk could have too many bsets for an iterator to fit
1105 	 * on the stack - have to dynamically allocate them
1106 	 */
1107 	mempool_t		fill_iter;
1108 
1109 	mempool_t		btree_bounce_pool;
1110 
1111 	struct journal		journal;
1112 	GENRADIX(struct journal_replay *) journal_entries;
1113 	u64			journal_entries_base_seq;
1114 	struct journal_keys	journal_keys;
1115 	struct list_head	journal_iters;
1116 
1117 	struct find_btree_nodes	found_btree_nodes;
1118 
1119 	u64			last_bucket_seq_cleanup;
1120 
1121 	u64			counters_on_mount[BCH_COUNTER_NR];
1122 	u64 __percpu		*counters;
1123 
1124 	unsigned		copy_gc_enabled:1;
1125 	bool			promote_whole_extents;
1126 
1127 	struct bch2_time_stats	times[BCH_TIME_STAT_NR];
1128 
1129 	struct btree_transaction_stats btree_transaction_stats[BCH_TRANSACTIONS_NR];
1130 
1131 	/* ERRORS */
1132 	struct list_head	fsck_error_msgs;
1133 	struct mutex		fsck_error_msgs_lock;
1134 	bool			fsck_alloc_msgs_err;
1135 
1136 	bch_sb_errors_cpu	fsck_error_counts;
1137 	struct mutex		fsck_error_counts_lock;
1138 };
1139 
1140 extern struct wait_queue_head bch2_read_only_wait;
1141 
1142 static inline void bch2_write_ref_get(struct bch_fs *c, enum bch_write_ref ref)
1143 {
1144 #ifdef BCH_WRITE_REF_DEBUG
1145 	atomic_long_inc(&c->writes[ref]);
1146 #else
1147 	percpu_ref_get(&c->writes);
1148 #endif
1149 }
1150 
1151 static inline bool __bch2_write_ref_tryget(struct bch_fs *c, enum bch_write_ref ref)
1152 {
1153 #ifdef BCH_WRITE_REF_DEBUG
1154 	return !test_bit(BCH_FS_going_ro, &c->flags) &&
1155 		atomic_long_inc_not_zero(&c->writes[ref]);
1156 #else
1157 	return percpu_ref_tryget(&c->writes);
1158 #endif
1159 }
1160 
1161 static inline bool bch2_write_ref_tryget(struct bch_fs *c, enum bch_write_ref ref)
1162 {
1163 #ifdef BCH_WRITE_REF_DEBUG
1164 	return !test_bit(BCH_FS_going_ro, &c->flags) &&
1165 		atomic_long_inc_not_zero(&c->writes[ref]);
1166 #else
1167 	return percpu_ref_tryget_live(&c->writes);
1168 #endif
1169 }
1170 
1171 static inline void bch2_write_ref_put(struct bch_fs *c, enum bch_write_ref ref)
1172 {
1173 #ifdef BCH_WRITE_REF_DEBUG
1174 	long v = atomic_long_dec_return(&c->writes[ref]);
1175 
1176 	BUG_ON(v < 0);
1177 	if (v)
1178 		return;
1179 	for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++)
1180 		if (atomic_long_read(&c->writes[i]))
1181 			return;
1182 
1183 	set_bit(BCH_FS_write_disable_complete, &c->flags);
1184 	wake_up(&bch2_read_only_wait);
1185 #else
1186 	percpu_ref_put(&c->writes);
1187 #endif
1188 }
1189 
1190 static inline bool bch2_ro_ref_tryget(struct bch_fs *c)
1191 {
1192 	if (test_bit(BCH_FS_stopping, &c->flags))
1193 		return false;
1194 
1195 	return refcount_inc_not_zero(&c->ro_ref);
1196 }
1197 
1198 static inline void bch2_ro_ref_put(struct bch_fs *c)
1199 {
1200 	if (refcount_dec_and_test(&c->ro_ref))
1201 		wake_up(&c->ro_ref_wait);
1202 }
1203 
1204 static inline void bch2_set_ra_pages(struct bch_fs *c, unsigned ra_pages)
1205 {
1206 #ifndef NO_BCACHEFS_FS
1207 	if (c->vfs_sb)
1208 		c->vfs_sb->s_bdi->ra_pages = ra_pages;
1209 #endif
1210 }
1211 
1212 static inline unsigned bucket_bytes(const struct bch_dev *ca)
1213 {
1214 	return ca->mi.bucket_size << 9;
1215 }
1216 
1217 static inline unsigned block_bytes(const struct bch_fs *c)
1218 {
1219 	return c->opts.block_size;
1220 }
1221 
1222 static inline unsigned block_sectors(const struct bch_fs *c)
1223 {
1224 	return c->opts.block_size >> 9;
1225 }
1226 
1227 static inline bool btree_id_cached(const struct bch_fs *c, enum btree_id btree)
1228 {
1229 	return c->btree_key_cache_btrees & (1U << btree);
1230 }
1231 
1232 static inline struct timespec64 bch2_time_to_timespec(const struct bch_fs *c, s64 time)
1233 {
1234 	struct timespec64 t;
1235 	s32 rem;
1236 
1237 	time += c->sb.time_base_lo;
1238 
1239 	t.tv_sec = div_s64_rem(time, c->sb.time_units_per_sec, &rem);
1240 	t.tv_nsec = rem * c->sb.nsec_per_time_unit;
1241 	return t;
1242 }
1243 
1244 static inline s64 timespec_to_bch2_time(const struct bch_fs *c, struct timespec64 ts)
1245 {
1246 	return (ts.tv_sec * c->sb.time_units_per_sec +
1247 		(int) ts.tv_nsec / c->sb.nsec_per_time_unit) - c->sb.time_base_lo;
1248 }
1249 
1250 static inline s64 bch2_current_time(const struct bch_fs *c)
1251 {
1252 	struct timespec64 now;
1253 
1254 	ktime_get_coarse_real_ts64(&now);
1255 	return timespec_to_bch2_time(c, now);
1256 }
1257 
1258 static inline struct stdio_redirect *bch2_fs_stdio_redirect(struct bch_fs *c)
1259 {
1260 	struct stdio_redirect *stdio = c->stdio;
1261 
1262 	if (c->stdio_filter && c->stdio_filter != current)
1263 		stdio = NULL;
1264 	return stdio;
1265 }
1266 
1267 static inline unsigned metadata_replicas_required(struct bch_fs *c)
1268 {
1269 	return min(c->opts.metadata_replicas,
1270 		   c->opts.metadata_replicas_required);
1271 }
1272 
1273 static inline unsigned data_replicas_required(struct bch_fs *c)
1274 {
1275 	return min(c->opts.data_replicas,
1276 		   c->opts.data_replicas_required);
1277 }
1278 
1279 #define BKEY_PADDED_ONSTACK(key, pad)				\
1280 	struct { struct bkey_i key; __u64 key ## _pad[pad]; }
1281 
1282 #endif /* _BCACHEFS_H */
1283