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 "disk_accounting_types.h"
209 #include "errcode.h"
210 #include "fifo.h"
211 #include "nocow_locking_types.h"
212 #include "opts.h"
213 #include "recovery_passes_types.h"
214 #include "sb-errors_types.h"
215 #include "seqmutex.h"
216 #include "time_stats.h"
217 #include "util.h"
218
219 #ifdef CONFIG_BCACHEFS_DEBUG
220 #define BCH_WRITE_REF_DEBUG
221 #endif
222
223 #ifndef dynamic_fault
224 #define dynamic_fault(...) 0
225 #endif
226
227 #define race_fault(...) dynamic_fault("bcachefs:race")
228
229 #define count_event(_c, _name) this_cpu_inc((_c)->counters[BCH_COUNTER_##_name])
230
231 #define trace_and_count(_c, _name, ...) \
232 do { \
233 count_event(_c, _name); \
234 trace_##_name(__VA_ARGS__); \
235 } while (0)
236
237 #define bch2_fs_init_fault(name) \
238 dynamic_fault("bcachefs:bch_fs_init:" name)
239 #define bch2_meta_read_fault(name) \
240 dynamic_fault("bcachefs:meta:read:" name)
241 #define bch2_meta_write_fault(name) \
242 dynamic_fault("bcachefs:meta:write:" name)
243
244 #ifdef __KERNEL__
245 #define BCACHEFS_LOG_PREFIX
246 #endif
247
248 #ifdef BCACHEFS_LOG_PREFIX
249
250 #define bch2_log_msg(_c, fmt) "bcachefs (%s): " fmt, ((_c)->name)
251 #define bch2_fmt_dev(_ca, fmt) "bcachefs (%s): " fmt "\n", ((_ca)->name)
252 #define bch2_fmt_dev_offset(_ca, _offset, fmt) "bcachefs (%s sector %llu): " fmt "\n", ((_ca)->name), (_offset)
253 #define bch2_fmt_inum(_c, _inum, fmt) "bcachefs (%s inum %llu): " fmt "\n", ((_c)->name), (_inum)
254 #define bch2_fmt_inum_offset(_c, _inum, _offset, fmt) \
255 "bcachefs (%s inum %llu offset %llu): " fmt "\n", ((_c)->name), (_inum), (_offset)
256
257 #else
258
259 #define bch2_log_msg(_c, fmt) fmt
260 #define bch2_fmt_dev(_ca, fmt) "%s: " fmt "\n", ((_ca)->name)
261 #define bch2_fmt_dev_offset(_ca, _offset, fmt) "%s sector %llu: " fmt "\n", ((_ca)->name), (_offset)
262 #define bch2_fmt_inum(_c, _inum, fmt) "inum %llu: " fmt "\n", (_inum)
263 #define bch2_fmt_inum_offset(_c, _inum, _offset, fmt) \
264 "inum %llu offset %llu: " fmt "\n", (_inum), (_offset)
265
266 #endif
267
268 #define bch2_fmt(_c, fmt) bch2_log_msg(_c, fmt "\n")
269
270 void bch2_print_str(struct bch_fs *, const char *);
271
272 __printf(2, 3)
273 void bch2_print_opts(struct bch_opts *, const char *, ...);
274
275 __printf(2, 3)
276 void __bch2_print(struct bch_fs *c, const char *fmt, ...);
277
278 #define maybe_dev_to_fs(_c) _Generic((_c), \
279 struct bch_dev *: ((struct bch_dev *) (_c))->fs, \
280 struct bch_fs *: (_c))
281
282 #define bch2_print(_c, ...) __bch2_print(maybe_dev_to_fs(_c), __VA_ARGS__)
283
284 #define bch2_print_ratelimited(_c, ...) \
285 do { \
286 static DEFINE_RATELIMIT_STATE(_rs, \
287 DEFAULT_RATELIMIT_INTERVAL, \
288 DEFAULT_RATELIMIT_BURST); \
289 \
290 if (__ratelimit(&_rs)) \
291 bch2_print(_c, __VA_ARGS__); \
292 } while (0)
293
294 #define bch_info(c, fmt, ...) \
295 bch2_print(c, KERN_INFO bch2_fmt(c, fmt), ##__VA_ARGS__)
296 #define bch_notice(c, fmt, ...) \
297 bch2_print(c, KERN_NOTICE bch2_fmt(c, fmt), ##__VA_ARGS__)
298 #define bch_warn(c, fmt, ...) \
299 bch2_print(c, KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__)
300 #define bch_warn_ratelimited(c, fmt, ...) \
301 bch2_print_ratelimited(c, KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__)
302
303 #define bch_err(c, fmt, ...) \
304 bch2_print(c, KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__)
305 #define bch_err_dev(ca, fmt, ...) \
306 bch2_print(c, KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__)
307 #define bch_err_dev_offset(ca, _offset, fmt, ...) \
308 bch2_print(c, KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__)
309 #define bch_err_inum(c, _inum, fmt, ...) \
310 bch2_print(c, KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__)
311 #define bch_err_inum_offset(c, _inum, _offset, fmt, ...) \
312 bch2_print(c, KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__)
313
314 #define bch_err_ratelimited(c, fmt, ...) \
315 bch2_print_ratelimited(c, KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__)
316 #define bch_err_dev_ratelimited(ca, fmt, ...) \
317 bch2_print_ratelimited(ca, KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__)
318 #define bch_err_dev_offset_ratelimited(ca, _offset, fmt, ...) \
319 bch2_print_ratelimited(ca, KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__)
320 #define bch_err_inum_ratelimited(c, _inum, fmt, ...) \
321 bch2_print_ratelimited(c, KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__)
322 #define bch_err_inum_offset_ratelimited(c, _inum, _offset, fmt, ...) \
323 bch2_print_ratelimited(c, KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__)
324
325 static inline bool should_print_err(int err)
326 {
327 return err && !bch2_err_matches(err, BCH_ERR_transaction_restart);
328 }
329
330 #define bch_err_fn(_c, _ret) \
331 do { \
332 if (should_print_err(_ret)) \
333 bch_err(_c, "%s(): error %s", __func__, bch2_err_str(_ret));\
334 } while (0)
335
336 #define bch_err_fn_ratelimited(_c, _ret) \
337 do { \
338 if (should_print_err(_ret)) \
339 bch_err_ratelimited(_c, "%s(): error %s", __func__, bch2_err_str(_ret));\
340 } while (0)
341
342 #define bch_err_msg(_c, _ret, _msg, ...) \
343 do { \
344 if (should_print_err(_ret)) \
345 bch_err(_c, "%s(): error " _msg " %s", __func__, \
346 ##__VA_ARGS__, bch2_err_str(_ret)); \
347 } while (0)
348
349 #define bch_verbose(c, fmt, ...) \
350 do { \
351 if ((c)->opts.verbose) \
352 bch_info(c, fmt, ##__VA_ARGS__); \
353 } while (0)
354
355 #define pr_verbose_init(opts, fmt, ...) \
356 do { \
357 if (opt_get(opts, verbose)) \
358 pr_info(fmt, ##__VA_ARGS__); \
359 } while (0)
360
361 /* Parameters that are useful for debugging, but should always be compiled in: */
362 #define BCH_DEBUG_PARAMS_ALWAYS() \
363 BCH_DEBUG_PARAM(key_merging_disabled, \
364 "Disables merging of extents") \
365 BCH_DEBUG_PARAM(btree_node_merging_disabled, \
366 "Disables merging of btree nodes") \
367 BCH_DEBUG_PARAM(btree_gc_always_rewrite, \
368 "Causes mark and sweep to compact and rewrite every " \
369 "btree node it traverses") \
370 BCH_DEBUG_PARAM(btree_gc_rewrite_disabled, \
371 "Disables rewriting of btree nodes during mark and sweep")\
372 BCH_DEBUG_PARAM(btree_shrinker_disabled, \
373 "Disables the shrinker callback for the btree node cache")\
374 BCH_DEBUG_PARAM(verify_btree_ondisk, \
375 "Reread btree nodes at various points to verify the " \
376 "mergesort in the read path against modifications " \
377 "done in memory") \
378 BCH_DEBUG_PARAM(verify_all_btree_replicas, \
379 "When reading btree nodes, read all replicas and " \
380 "compare them") \
381 BCH_DEBUG_PARAM(backpointers_no_use_write_buffer, \
382 "Don't use the write buffer for backpointers, enabling "\
383 "extra runtime checks")
384
385 /* Parameters that should only be compiled in debug mode: */
386 #define BCH_DEBUG_PARAMS_DEBUG() \
387 BCH_DEBUG_PARAM(expensive_debug_checks, \
388 "Enables various runtime debugging checks that " \
389 "significantly affect performance") \
390 BCH_DEBUG_PARAM(debug_check_iterators, \
391 "Enables extra verification for btree iterators") \
392 BCH_DEBUG_PARAM(debug_check_btree_accounting, \
393 "Verify btree accounting for keys within a node") \
394 BCH_DEBUG_PARAM(journal_seq_verify, \
395 "Store the journal sequence number in the version " \
396 "number of every btree key, and verify that btree " \
397 "update ordering is preserved during recovery") \
398 BCH_DEBUG_PARAM(inject_invalid_keys, \
399 "Store the journal sequence number in the version " \
400 "number of every btree key, and verify that btree " \
401 "update ordering is preserved during recovery") \
402 BCH_DEBUG_PARAM(test_alloc_startup, \
403 "Force allocator startup to use the slowpath where it" \
404 "can't find enough free buckets without invalidating" \
405 "cached data") \
406 BCH_DEBUG_PARAM(force_reconstruct_read, \
407 "Force reads to use the reconstruct path, when reading" \
408 "from erasure coded extents") \
409 BCH_DEBUG_PARAM(test_restart_gc, \
410 "Test restarting mark and sweep gc when bucket gens change")
411
412 #define BCH_DEBUG_PARAMS_ALL() BCH_DEBUG_PARAMS_ALWAYS() BCH_DEBUG_PARAMS_DEBUG()
413
414 #ifdef CONFIG_BCACHEFS_DEBUG
415 #define BCH_DEBUG_PARAMS() BCH_DEBUG_PARAMS_ALL()
416 #else
417 #define BCH_DEBUG_PARAMS() BCH_DEBUG_PARAMS_ALWAYS()
418 #endif
419
420 #define BCH_DEBUG_PARAM(name, description) extern bool bch2_##name;
421 BCH_DEBUG_PARAMS()
422 #undef BCH_DEBUG_PARAM
423
424 #ifndef CONFIG_BCACHEFS_DEBUG
425 #define BCH_DEBUG_PARAM(name, description) static const __maybe_unused bool bch2_##name;
426 BCH_DEBUG_PARAMS_DEBUG()
427 #undef BCH_DEBUG_PARAM
428 #endif
429
430 #define BCH_TIME_STATS() \
431 x(btree_node_mem_alloc) \
432 x(btree_node_split) \
433 x(btree_node_compact) \
434 x(btree_node_merge) \
435 x(btree_node_sort) \
436 x(btree_node_read) \
437 x(btree_node_read_done) \
438 x(btree_interior_update_foreground) \
439 x(btree_interior_update_total) \
440 x(btree_gc) \
441 x(data_write) \
442 x(data_read) \
443 x(data_promote) \
444 x(journal_flush_write) \
445 x(journal_noflush_write) \
446 x(journal_flush_seq) \
447 x(blocked_journal_low_on_space) \
448 x(blocked_journal_low_on_pin) \
449 x(blocked_journal_max_in_flight) \
450 x(blocked_key_cache_flush) \
451 x(blocked_allocate) \
452 x(blocked_allocate_open_bucket) \
453 x(blocked_write_buffer_full) \
454 x(nocow_lock_contended)
455
456 enum bch_time_stats {
457 #define x(name) BCH_TIME_##name,
458 BCH_TIME_STATS()
459 #undef x
460 BCH_TIME_STAT_NR
461 };
462
463 #include "alloc_types.h"
464 #include "btree_gc_types.h"
465 #include "btree_types.h"
466 #include "btree_node_scan_types.h"
467 #include "btree_write_buffer_types.h"
468 #include "buckets_types.h"
469 #include "buckets_waiting_for_journal_types.h"
470 #include "clock_types.h"
471 #include "disk_groups_types.h"
472 #include "ec_types.h"
473 #include "journal_types.h"
474 #include "keylist_types.h"
475 #include "quota_types.h"
476 #include "rebalance_types.h"
477 #include "replicas_types.h"
478 #include "sb-members_types.h"
479 #include "subvolume_types.h"
480 #include "super_types.h"
481 #include "thread_with_file_types.h"
482
483 /* Number of nodes btree coalesce will try to coalesce at once */
484 #define GC_MERGE_NODES 4U
485
486 /* Maximum number of nodes we might need to allocate atomically: */
487 #define BTREE_RESERVE_MAX (BTREE_MAX_DEPTH + (BTREE_MAX_DEPTH - 1))
488
489 /* Size of the freelist we allocate btree nodes from: */
490 #define BTREE_NODE_RESERVE (BTREE_RESERVE_MAX * 4)
491
492 #define BTREE_NODE_OPEN_BUCKET_RESERVE (BTREE_RESERVE_MAX * BCH_REPLICAS_MAX)
493
494 struct btree;
495
496 struct io_count {
497 u64 sectors[2][BCH_DATA_NR];
498 };
499
500 struct discard_in_flight {
501 bool in_progress:1;
502 u64 bucket:63;
503 };
504
505 struct bch_dev {
506 struct kobject kobj;
507 #ifdef CONFIG_BCACHEFS_DEBUG
508 atomic_long_t ref;
509 bool dying;
510 unsigned long last_put;
511 #else
512 struct percpu_ref ref;
513 #endif
514 struct completion ref_completion;
515 struct percpu_ref io_ref;
516 struct completion io_ref_completion;
517
518 struct bch_fs *fs;
519
520 u8 dev_idx;
521 /*
522 * Cached version of this device's member info from superblock
523 * Committed by bch2_write_super() -> bch_fs_mi_update()
524 */
525 struct bch_member_cpu mi;
526 atomic64_t errors[BCH_MEMBER_ERROR_NR];
527
528 __uuid_t uuid;
529 char name[BDEVNAME_SIZE];
530
531 struct bch_sb_handle disk_sb;
532 struct bch_sb *sb_read_scratch;
533 int sb_write_error;
534 dev_t dev;
535 atomic_t flush_seq;
536
537 struct bch_devs_mask self;
538
539 /*
540 * Buckets:
541 * Per-bucket arrays are protected by c->mark_lock, bucket_lock and
542 * gc_gens_lock, for device resize - holding any is sufficient for
543 * access: Or rcu_read_lock(), but only for dev_ptr_stale():
544 */
545 struct bucket_array __rcu *buckets_gc;
546 struct bucket_gens __rcu *bucket_gens;
547 u8 *oldest_gen;
548 unsigned long *buckets_nouse;
549 struct rw_semaphore bucket_lock;
550
551 struct bch_dev_usage __percpu *usage;
552
553 /* Allocator: */
554 u64 new_fs_bucket_idx;
555 u64 alloc_cursor[3];
556
557 unsigned nr_open_buckets;
558 unsigned nr_btree_reserve;
559
560 size_t inc_gen_needs_gc;
561 size_t inc_gen_really_needs_gc;
562 size_t buckets_waiting_on_journal;
563
564 struct work_struct invalidate_work;
565 struct work_struct discard_work;
566 struct mutex discard_buckets_in_flight_lock;
567 DARRAY(struct discard_in_flight) discard_buckets_in_flight;
568 struct work_struct discard_fast_work;
569
570 atomic64_t rebalance_work;
571
572 struct journal_device journal;
573 u64 prev_journal_sector;
574
575 struct work_struct io_error_work;
576
577 /* The rest of this all shows up in sysfs */
578 atomic64_t cur_latency[2];
579 struct bch2_time_stats_quantiles io_latency[2];
580
581 #define CONGESTED_MAX 1024
582 atomic_t congested;
583 u64 congested_last;
584
585 struct io_count __percpu *io_done;
586 };
587
588 /*
589 * initial_gc_unfixed
590 * error
591 * topology error
592 */
593
594 #define BCH_FS_FLAGS() \
595 x(new_fs) \
596 x(started) \
597 x(btree_running) \
598 x(accounting_replay_done) \
599 x(may_go_rw) \
600 x(rw) \
601 x(was_rw) \
602 x(stopping) \
603 x(emergency_ro) \
604 x(going_ro) \
605 x(write_disable_complete) \
606 x(clean_shutdown) \
607 x(fsck_running) \
608 x(initial_gc_unfixed) \
609 x(need_delete_dead_snapshots) \
610 x(error) \
611 x(topology_error) \
612 x(errors_fixed) \
613 x(errors_not_fixed) \
614 x(no_invalid_checks)
615
616 enum bch_fs_flags {
617 #define x(n) BCH_FS_##n,
618 BCH_FS_FLAGS()
619 #undef x
620 };
621
622 struct btree_debug {
623 unsigned id;
624 };
625
626 #define BCH_TRANSACTIONS_NR 128
627
628 struct btree_transaction_stats {
629 struct bch2_time_stats duration;
630 struct bch2_time_stats lock_hold_times;
631 struct mutex lock;
632 unsigned nr_max_paths;
633 unsigned journal_entries_size;
634 unsigned max_mem;
635 char *max_paths_text;
636 };
637
638 struct bch_fs_pcpu {
639 u64 sectors_available;
640 };
641
642 struct journal_seq_blacklist_table {
643 size_t nr;
644 struct journal_seq_blacklist_table_entry {
645 u64 start;
646 u64 end;
647 bool dirty;
648 } entries[];
649 };
650
651 struct journal_keys {
652 /* must match layout in darray_types.h */
653 size_t nr, size;
654 struct journal_key {
655 u64 journal_seq;
656 u32 journal_offset;
657 enum btree_id btree_id:8;
658 unsigned level:8;
659 bool allocated;
660 bool overwritten;
661 struct bkey_i *k;
662 } *data;
663 /*
664 * Gap buffer: instead of all the empty space in the array being at the
665 * end of the buffer - from @nr to @size - the empty space is at @gap.
666 * This means that sequential insertions are O(n) instead of O(n^2).
667 */
668 size_t gap;
669 atomic_t ref;
670 bool initial_ref_held;
671 };
672
673 struct btree_trans_buf {
674 struct btree_trans *trans;
675 };
676
677 #define BCACHEFS_ROOT_SUBVOL_INUM \
678 ((subvol_inum) { BCACHEFS_ROOT_SUBVOL, BCACHEFS_ROOT_INO })
679
680 #define BCH_WRITE_REFS() \
681 x(trans) \
682 x(write) \
683 x(promote) \
684 x(node_rewrite) \
685 x(stripe_create) \
686 x(stripe_delete) \
687 x(reflink) \
688 x(fallocate) \
689 x(fsync) \
690 x(dio_write) \
691 x(discard) \
692 x(discard_fast) \
693 x(invalidate) \
694 x(delete_dead_snapshots) \
695 x(gc_gens) \
696 x(snapshot_delete_pagecache) \
697 x(sysfs) \
698 x(btree_write_buffer)
699
700 enum bch_write_ref {
701 #define x(n) BCH_WRITE_REF_##n,
702 BCH_WRITE_REFS()
703 #undef x
704 BCH_WRITE_REF_NR,
705 };
706
707 struct bch_fs {
708 struct closure cl;
709
710 struct list_head list;
711 struct kobject kobj;
712 struct kobject counters_kobj;
713 struct kobject internal;
714 struct kobject opts_dir;
715 struct kobject time_stats;
716 unsigned long flags;
717
718 int minor;
719 struct device *chardev;
720 struct super_block *vfs_sb;
721 dev_t dev;
722 char name[40];
723 struct stdio_redirect *stdio;
724 struct task_struct *stdio_filter;
725
726 /* ro/rw, add/remove/resize devices: */
727 struct rw_semaphore state_lock;
728
729 /* Counts outstanding writes, for clean transition to read-only */
730 #ifdef BCH_WRITE_REF_DEBUG
731 atomic_long_t writes[BCH_WRITE_REF_NR];
732 #else
733 struct percpu_ref writes;
734 #endif
735 /*
736 * Analagous to c->writes, for asynchronous ops that don't necessarily
737 * need fs to be read-write
738 */
739 refcount_t ro_ref;
740 wait_queue_head_t ro_ref_wait;
741
742 struct work_struct read_only_work;
743
744 struct bch_dev __rcu *devs[BCH_SB_MEMBERS_MAX];
745
746 struct bch_accounting_mem accounting;
747
748 struct bch_replicas_cpu replicas;
749 struct bch_replicas_cpu replicas_gc;
750 struct mutex replicas_gc_lock;
751
752 struct journal_entry_res btree_root_journal_res;
753 struct journal_entry_res clock_journal_res;
754
755 struct bch_disk_groups_cpu __rcu *disk_groups;
756
757 struct bch_opts opts;
758
759 /* Updated by bch2_sb_update():*/
760 struct {
761 __uuid_t uuid;
762 __uuid_t user_uuid;
763
764 u16 version;
765 u16 version_min;
766 u16 version_upgrade_complete;
767
768 u8 nr_devices;
769 u8 clean;
770
771 u8 encryption_type;
772
773 u64 time_base_lo;
774 u32 time_base_hi;
775 unsigned time_units_per_sec;
776 unsigned nsec_per_time_unit;
777 u64 features;
778 u64 compat;
779 unsigned long errors_silent[BITS_TO_LONGS(BCH_SB_ERR_MAX)];
780 u64 btrees_lost_data;
781 } sb;
782
783
784 struct bch_sb_handle disk_sb;
785
786 unsigned short block_bits; /* ilog2(block_size) */
787
788 u16 btree_foreground_merge_threshold;
789
790 struct closure sb_write;
791 struct mutex sb_lock;
792
793 /* snapshot.c: */
794 struct snapshot_table __rcu *snapshots;
795 struct mutex snapshot_table_lock;
796 struct rw_semaphore snapshot_create_lock;
797
798 struct work_struct snapshot_delete_work;
799 struct work_struct snapshot_wait_for_pagecache_and_delete_work;
800 snapshot_id_list snapshots_unlinked;
801 struct mutex snapshots_unlinked_lock;
802
803 /* BTREE CACHE */
804 struct bio_set btree_bio;
805 struct workqueue_struct *btree_read_complete_wq;
806 struct workqueue_struct *btree_write_submit_wq;
807
808 struct btree_root btree_roots_known[BTREE_ID_NR];
809 DARRAY(struct btree_root) btree_roots_extra;
810 struct mutex btree_root_lock;
811
812 struct btree_cache btree_cache;
813
814 /*
815 * Cache of allocated btree nodes - if we allocate a btree node and
816 * don't use it, if we free it that space can't be reused until going
817 * _all_ the way through the allocator (which exposes us to a livelock
818 * when allocating btree reserves fail halfway through) - instead, we
819 * can stick them here:
820 */
821 struct btree_alloc btree_reserve_cache[BTREE_NODE_RESERVE * 2];
822 unsigned btree_reserve_cache_nr;
823 struct mutex btree_reserve_cache_lock;
824
825 mempool_t btree_interior_update_pool;
826 struct list_head btree_interior_update_list;
827 struct list_head btree_interior_updates_unwritten;
828 struct mutex btree_interior_update_lock;
829 struct closure_waitlist btree_interior_update_wait;
830
831 struct workqueue_struct *btree_interior_update_worker;
832 struct work_struct btree_interior_update_work;
833
834 struct workqueue_struct *btree_node_rewrite_worker;
835
836 struct list_head pending_node_rewrites;
837 struct mutex pending_node_rewrites_lock;
838
839 /* btree_io.c: */
840 spinlock_t btree_write_error_lock;
841 struct btree_write_stats {
842 atomic64_t nr;
843 atomic64_t bytes;
844 } btree_write_stats[BTREE_WRITE_TYPE_NR];
845
846 /* btree_iter.c: */
847 struct seqmutex btree_trans_lock;
848 struct list_head btree_trans_list;
849 mempool_t btree_trans_pool;
850 mempool_t btree_trans_mem_pool;
851 struct btree_trans_buf __percpu *btree_trans_bufs;
852
853 struct srcu_struct btree_trans_barrier;
854 bool btree_trans_barrier_initialized;
855
856 struct btree_key_cache btree_key_cache;
857 unsigned btree_key_cache_btrees;
858
859 struct btree_write_buffer btree_write_buffer;
860
861 struct workqueue_struct *btree_update_wq;
862 struct workqueue_struct *btree_io_complete_wq;
863 /* copygc needs its own workqueue for index updates.. */
864 struct workqueue_struct *copygc_wq;
865 /*
866 * Use a dedicated wq for write ref holder tasks. Required to avoid
867 * dependency problems with other wq tasks that can block on ref
868 * draining, such as read-only transition.
869 */
870 struct workqueue_struct *write_ref_wq;
871
872 /* ALLOCATION */
873 struct bch_devs_mask rw_devs[BCH_DATA_NR];
874
875 u64 capacity; /* sectors */
876 u64 reserved; /* sectors */
877
878 /*
879 * When capacity _decreases_ (due to a disk being removed), we
880 * increment capacity_gen - this invalidates outstanding reservations
881 * and forces them to be revalidated
882 */
883 u32 capacity_gen;
884 unsigned bucket_size_max;
885
886 atomic64_t sectors_available;
887 struct mutex sectors_available_lock;
888
889 struct bch_fs_pcpu __percpu *pcpu;
890
891 struct percpu_rw_semaphore mark_lock;
892
893 seqcount_t usage_lock;
894 struct bch_fs_usage_base __percpu *usage;
895 u64 __percpu *online_reserved;
896
897 unsigned long allocator_last_stuck;
898
899 struct io_clock io_clock[2];
900
901 /* JOURNAL SEQ BLACKLIST */
902 struct journal_seq_blacklist_table *
903 journal_seq_blacklist_table;
904
905 /* ALLOCATOR */
906 spinlock_t freelist_lock;
907 struct closure_waitlist freelist_wait;
908
909 open_bucket_idx_t open_buckets_freelist;
910 open_bucket_idx_t open_buckets_nr_free;
911 struct closure_waitlist open_buckets_wait;
912 struct open_bucket open_buckets[OPEN_BUCKETS_COUNT];
913 open_bucket_idx_t open_buckets_hash[OPEN_BUCKETS_COUNT];
914
915 open_bucket_idx_t open_buckets_partial[OPEN_BUCKETS_COUNT];
916 open_bucket_idx_t open_buckets_partial_nr;
917
918 struct write_point btree_write_point;
919 struct write_point rebalance_write_point;
920
921 struct write_point write_points[WRITE_POINT_MAX];
922 struct hlist_head write_points_hash[WRITE_POINT_HASH_NR];
923 struct mutex write_points_hash_lock;
924 unsigned write_points_nr;
925
926 struct buckets_waiting_for_journal buckets_waiting_for_journal;
927
928 /* GARBAGE COLLECTION */
929 struct work_struct gc_gens_work;
930 unsigned long gc_count;
931
932 enum btree_id gc_gens_btree;
933 struct bpos gc_gens_pos;
934
935 /*
936 * Tracks GC's progress - everything in the range [ZERO_KEY..gc_cur_pos]
937 * has been marked by GC.
938 *
939 * gc_cur_phase is a superset of btree_ids (BTREE_ID_extents etc.)
940 *
941 * Protected by gc_pos_lock. Only written to by GC thread, so GC thread
942 * can read without a lock.
943 */
944 seqcount_t gc_pos_lock;
945 struct gc_pos gc_pos;
946
947 /*
948 * The allocation code needs gc_mark in struct bucket to be correct, but
949 * it's not while a gc is in progress.
950 */
951 struct rw_semaphore gc_lock;
952 struct mutex gc_gens_lock;
953
954 /* IO PATH */
955 struct semaphore io_in_flight;
956 struct bio_set bio_read;
957 struct bio_set bio_read_split;
958 struct bio_set bio_write;
959 struct bio_set replica_set;
960 struct mutex bio_bounce_pages_lock;
961 mempool_t bio_bounce_pages;
962 struct bucket_nocow_lock_table
963 nocow_locks;
964 struct rhashtable promote_table;
965
966 mempool_t compression_bounce[2];
967 mempool_t compress_workspace[BCH_COMPRESSION_TYPE_NR];
968 mempool_t decompress_workspace;
969 size_t zstd_workspace_size;
970
971 struct crypto_shash *sha256;
972 struct crypto_sync_skcipher *chacha20;
973 struct crypto_shash *poly1305;
974
975 atomic64_t key_version;
976
977 mempool_t large_bkey_pool;
978
979 /* MOVE.C */
980 struct list_head moving_context_list;
981 struct mutex moving_context_lock;
982
983 /* REBALANCE */
984 struct bch_fs_rebalance rebalance;
985
986 /* COPYGC */
987 struct task_struct *copygc_thread;
988 struct write_point copygc_write_point;
989 s64 copygc_wait_at;
990 s64 copygc_wait;
991 bool copygc_running;
992 wait_queue_head_t copygc_running_wq;
993
994 /* STRIPES: */
995 GENRADIX(struct stripe) stripes;
996 GENRADIX(struct gc_stripe) gc_stripes;
997
998 struct hlist_head ec_stripes_new[32];
999 spinlock_t ec_stripes_new_lock;
1000
1001 ec_stripes_heap ec_stripes_heap;
1002 struct mutex ec_stripes_heap_lock;
1003
1004 /* ERASURE CODING */
1005 struct list_head ec_stripe_head_list;
1006 struct mutex ec_stripe_head_lock;
1007
1008 struct list_head ec_stripe_new_list;
1009 struct mutex ec_stripe_new_lock;
1010 wait_queue_head_t ec_stripe_new_wait;
1011
1012 struct work_struct ec_stripe_create_work;
1013 u64 ec_stripe_hint;
1014
1015 struct work_struct ec_stripe_delete_work;
1016
1017 struct bio_set ec_bioset;
1018
1019 /* REFLINK */
1020 reflink_gc_table reflink_gc_table;
1021 size_t reflink_gc_nr;
1022
1023 /* fs.c */
1024 struct list_head vfs_inodes_list;
1025 struct mutex vfs_inodes_lock;
1026
1027 /* VFS IO PATH - fs-io.c */
1028 struct bio_set writepage_bioset;
1029 struct bio_set dio_write_bioset;
1030 struct bio_set dio_read_bioset;
1031 struct bio_set nocow_flush_bioset;
1032
1033 /* QUOTAS */
1034 struct bch_memquota_type quotas[QTYP_NR];
1035
1036 /* RECOVERY */
1037 u64 journal_replay_seq_start;
1038 u64 journal_replay_seq_end;
1039 /*
1040 * Two different uses:
1041 * "Has this fsck pass?" - i.e. should this type of error be an
1042 * emergency read-only
1043 * And, in certain situations fsck will rewind to an earlier pass: used
1044 * for signaling to the toplevel code which pass we want to run now.
1045 */
1046 enum bch_recovery_pass curr_recovery_pass;
1047 /* bitmap of explicitly enabled recovery passes: */
1048 u64 recovery_passes_explicit;
1049 /* bitmask of recovery passes that we actually ran */
1050 u64 recovery_passes_complete;
1051 /* never rewinds version of curr_recovery_pass */
1052 enum bch_recovery_pass recovery_pass_done;
1053 struct semaphore online_fsck_mutex;
1054
1055 /* DEBUG JUNK */
1056 struct dentry *fs_debug_dir;
1057 struct dentry *btree_debug_dir;
1058 struct btree_debug btree_debug[BTREE_ID_NR];
1059 struct btree *verify_data;
1060 struct btree_node *verify_ondisk;
1061 struct mutex verify_lock;
1062
1063 u64 *unused_inode_hints;
1064 unsigned inode_shard_bits;
1065
1066 /*
1067 * A btree node on disk could have too many bsets for an iterator to fit
1068 * on the stack - have to dynamically allocate them
1069 */
1070 mempool_t fill_iter;
1071
1072 mempool_t btree_bounce_pool;
1073
1074 struct journal journal;
1075 GENRADIX(struct journal_replay *) journal_entries;
1076 u64 journal_entries_base_seq;
1077 struct journal_keys journal_keys;
1078 struct list_head journal_iters;
1079
1080 struct find_btree_nodes found_btree_nodes;
1081
1082 u64 last_bucket_seq_cleanup;
1083
1084 u64 counters_on_mount[BCH_COUNTER_NR];
1085 u64 __percpu *counters;
1086
1087 unsigned copy_gc_enabled:1;
1088 bool promote_whole_extents;
1089
1090 struct bch2_time_stats times[BCH_TIME_STAT_NR];
1091
1092 struct btree_transaction_stats btree_transaction_stats[BCH_TRANSACTIONS_NR];
1093
1094 /* ERRORS */
1095 struct list_head fsck_error_msgs;
1096 struct mutex fsck_error_msgs_lock;
1097 bool fsck_alloc_msgs_err;
1098
1099 bch_sb_errors_cpu fsck_error_counts;
1100 struct mutex fsck_error_counts_lock;
1101 };
1102
1103 extern struct wait_queue_head bch2_read_only_wait;
1104
1105 static inline void bch2_write_ref_get(struct bch_fs *c, enum bch_write_ref ref)
1106 {
1107 #ifdef BCH_WRITE_REF_DEBUG
1108 atomic_long_inc(&c->writes[ref]);
1109 #else
1110 percpu_ref_get(&c->writes);
1111 #endif
1112 }
1113
1114 static inline bool __bch2_write_ref_tryget(struct bch_fs *c, enum bch_write_ref ref)
1115 {
1116 #ifdef BCH_WRITE_REF_DEBUG
1117 return !test_bit(BCH_FS_going_ro, &c->flags) &&
1118 atomic_long_inc_not_zero(&c->writes[ref]);
1119 #else
1120 return percpu_ref_tryget(&c->writes);
1121 #endif
1122 }
1123
1124 static inline bool bch2_write_ref_tryget(struct bch_fs *c, enum bch_write_ref ref)
1125 {
1126 #ifdef BCH_WRITE_REF_DEBUG
1127 return !test_bit(BCH_FS_going_ro, &c->flags) &&
1128 atomic_long_inc_not_zero(&c->writes[ref]);
1129 #else
1130 return percpu_ref_tryget_live(&c->writes);
1131 #endif
1132 }
1133
1134 static inline void bch2_write_ref_put(struct bch_fs *c, enum bch_write_ref ref)
1135 {
1136 #ifdef BCH_WRITE_REF_DEBUG
1137 long v = atomic_long_dec_return(&c->writes[ref]);
1138
1139 BUG_ON(v < 0);
1140 if (v)
1141 return;
1142 for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++)
1143 if (atomic_long_read(&c->writes[i]))
1144 return;
1145
1146 set_bit(BCH_FS_write_disable_complete, &c->flags);
1147 wake_up(&bch2_read_only_wait);
1148 #else
1149 percpu_ref_put(&c->writes);
1150 #endif
1151 }
1152
1153 static inline bool bch2_ro_ref_tryget(struct bch_fs *c)
1154 {
1155 if (test_bit(BCH_FS_stopping, &c->flags))
1156 return false;
1157
1158 return refcount_inc_not_zero(&c->ro_ref);
1159 }
1160
1161 static inline void bch2_ro_ref_put(struct bch_fs *c)
1162 {
1163 if (refcount_dec_and_test(&c->ro_ref))
1164 wake_up(&c->ro_ref_wait);
1165 }
1166
1167 static inline void bch2_set_ra_pages(struct bch_fs *c, unsigned ra_pages)
1168 {
1169 #ifndef NO_BCACHEFS_FS
1170 if (c->vfs_sb)
1171 c->vfs_sb->s_bdi->ra_pages = ra_pages;
1172 #endif
1173 }
1174
1175 static inline unsigned bucket_bytes(const struct bch_dev *ca)
1176 {
1177 return ca->mi.bucket_size << 9;
1178 }
1179
1180 static inline unsigned block_bytes(const struct bch_fs *c)
1181 {
1182 return c->opts.block_size;
1183 }
1184
1185 static inline unsigned block_sectors(const struct bch_fs *c)
1186 {
1187 return c->opts.block_size >> 9;
1188 }
1189
1190 static inline bool btree_id_cached(const struct bch_fs *c, enum btree_id btree)
1191 {
1192 return c->btree_key_cache_btrees & (1U << btree);
1193 }
1194
1195 static inline struct timespec64 bch2_time_to_timespec(const struct bch_fs *c, s64 time)
1196 {
1197 struct timespec64 t;
1198 s32 rem;
1199
1200 time += c->sb.time_base_lo;
1201
1202 t.tv_sec = div_s64_rem(time, c->sb.time_units_per_sec, &rem);
1203 t.tv_nsec = rem * c->sb.nsec_per_time_unit;
1204 return t;
1205 }
1206
1207 static inline s64 timespec_to_bch2_time(const struct bch_fs *c, struct timespec64 ts)
1208 {
1209 return (ts.tv_sec * c->sb.time_units_per_sec +
1210 (int) ts.tv_nsec / c->sb.nsec_per_time_unit) - c->sb.time_base_lo;
1211 }
1212
1213 static inline s64 bch2_current_time(const struct bch_fs *c)
1214 {
1215 struct timespec64 now;
1216
1217 ktime_get_coarse_real_ts64(&now);
1218 return timespec_to_bch2_time(c, now);
1219 }
1220
1221 static inline u64 bch2_current_io_time(const struct bch_fs *c, int rw)
1222 {
1223 return max(1ULL, (u64) atomic64_read(&c->io_clock[rw].now) & LRU_TIME_MAX);
1224 }
1225
1226 static inline struct stdio_redirect *bch2_fs_stdio_redirect(struct bch_fs *c)
1227 {
1228 struct stdio_redirect *stdio = c->stdio;
1229
1230 if (c->stdio_filter && c->stdio_filter != current)
1231 stdio = NULL;
1232 return stdio;
1233 }
1234
1235 static inline unsigned metadata_replicas_required(struct bch_fs *c)
1236 {
1237 return min(c->opts.metadata_replicas,
1238 c->opts.metadata_replicas_required);
1239 }
1240
1241 static inline unsigned data_replicas_required(struct bch_fs *c)
1242 {
1243 return min(c->opts.data_replicas,
1244 c->opts.data_replicas_required);
1245 }
1246
1247 #define BKEY_PADDED_ONSTACK(key, pad) \
1248 struct { struct bkey_i key; __u64 key ## _pad[pad]; }
1249
1250 #endif /* _BCACHEFS_H */
1251
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.