xref: /linux/fs/bcachefs/extents.c (revision ab58a2f319de945f631150a190653a90e307df8e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2010 Kent Overstreet <kent.overstreet@gmail.com>
4  *
5  * Code for managing the extent btree and dynamically updating the writeback
6  * dirty sector count.
7  */
8 
9 #include "bcachefs.h"
10 #include "bkey_methods.h"
11 #include "btree_cache.h"
12 #include "btree_gc.h"
13 #include "btree_io.h"
14 #include "btree_iter.h"
15 #include "buckets.h"
16 #include "checksum.h"
17 #include "compress.h"
18 #include "debug.h"
19 #include "disk_groups.h"
20 #include "error.h"
21 #include "extents.h"
22 #include "inode.h"
23 #include "journal.h"
24 #include "replicas.h"
25 #include "super.h"
26 #include "super-io.h"
27 #include "trace.h"
28 #include "util.h"
29 
30 static unsigned bch2_crc_field_size_max[] = {
31 	[BCH_EXTENT_ENTRY_crc32] = CRC32_SIZE_MAX,
32 	[BCH_EXTENT_ENTRY_crc64] = CRC64_SIZE_MAX,
33 	[BCH_EXTENT_ENTRY_crc128] = CRC128_SIZE_MAX,
34 };
35 
36 static void bch2_extent_crc_pack(union bch_extent_crc *,
37 				 struct bch_extent_crc_unpacked,
38 				 enum bch_extent_entry_type);
39 
40 static struct bch_dev_io_failures *dev_io_failures(struct bch_io_failures *f,
41 						   unsigned dev)
42 {
43 	struct bch_dev_io_failures *i;
44 
45 	for (i = f->devs; i < f->devs + f->nr; i++)
46 		if (i->dev == dev)
47 			return i;
48 
49 	return NULL;
50 }
51 
52 void bch2_mark_io_failure(struct bch_io_failures *failed,
53 			  struct extent_ptr_decoded *p)
54 {
55 	struct bch_dev_io_failures *f = dev_io_failures(failed, p->ptr.dev);
56 
57 	if (!f) {
58 		BUG_ON(failed->nr >= ARRAY_SIZE(failed->devs));
59 
60 		f = &failed->devs[failed->nr++];
61 		f->dev		= p->ptr.dev;
62 		f->idx		= p->idx;
63 		f->nr_failed	= 1;
64 		f->nr_retries	= 0;
65 	} else if (p->idx != f->idx) {
66 		f->idx		= p->idx;
67 		f->nr_failed	= 1;
68 		f->nr_retries	= 0;
69 	} else {
70 		f->nr_failed++;
71 	}
72 }
73 
74 /*
75  * returns true if p1 is better than p2:
76  */
77 static inline bool ptr_better(struct bch_fs *c,
78 			      const struct extent_ptr_decoded p1,
79 			      const struct extent_ptr_decoded p2)
80 {
81 	if (likely(!p1.idx && !p2.idx)) {
82 		struct bch_dev *dev1 = bch_dev_bkey_exists(c, p1.ptr.dev);
83 		struct bch_dev *dev2 = bch_dev_bkey_exists(c, p2.ptr.dev);
84 
85 		u64 l1 = atomic64_read(&dev1->cur_latency[READ]);
86 		u64 l2 = atomic64_read(&dev2->cur_latency[READ]);
87 
88 		/* Pick at random, biased in favor of the faster device: */
89 
90 		return bch2_rand_range(l1 + l2) > l1;
91 	}
92 
93 	if (bch2_force_reconstruct_read)
94 		return p1.idx > p2.idx;
95 
96 	return p1.idx < p2.idx;
97 }
98 
99 /*
100  * This picks a non-stale pointer, preferably from a device other than @avoid.
101  * Avoid can be NULL, meaning pick any. If there are no non-stale pointers to
102  * other devices, it will still pick a pointer from avoid.
103  */
104 int bch2_bkey_pick_read_device(struct bch_fs *c, struct bkey_s_c k,
105 			       struct bch_io_failures *failed,
106 			       struct extent_ptr_decoded *pick)
107 {
108 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
109 	const union bch_extent_entry *entry;
110 	struct extent_ptr_decoded p;
111 	struct bch_dev_io_failures *f;
112 	struct bch_dev *ca;
113 	int ret = 0;
114 
115 	if (k.k->type == KEY_TYPE_error)
116 		return -EIO;
117 
118 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
119 		/*
120 		 * Unwritten extent: no need to actually read, treat it as a
121 		 * hole and return 0s:
122 		 */
123 		if (p.ptr.unwritten)
124 			return 0;
125 
126 		ca = bch_dev_bkey_exists(c, p.ptr.dev);
127 
128 		/*
129 		 * If there are any dirty pointers it's an error if we can't
130 		 * read:
131 		 */
132 		if (!ret && !p.ptr.cached)
133 			ret = -EIO;
134 
135 		if (p.ptr.cached && ptr_stale(ca, &p.ptr))
136 			continue;
137 
138 		f = failed ? dev_io_failures(failed, p.ptr.dev) : NULL;
139 		if (f)
140 			p.idx = f->nr_failed < f->nr_retries
141 				? f->idx
142 				: f->idx + 1;
143 
144 		if (!p.idx &&
145 		    !bch2_dev_is_readable(ca))
146 			p.idx++;
147 
148 		if (bch2_force_reconstruct_read &&
149 		    !p.idx && p.has_ec)
150 			p.idx++;
151 
152 		if (p.idx >= (unsigned) p.has_ec + 1)
153 			continue;
154 
155 		if (ret > 0 && !ptr_better(c, p, *pick))
156 			continue;
157 
158 		*pick = p;
159 		ret = 1;
160 	}
161 
162 	return ret;
163 }
164 
165 /* KEY_TYPE_btree_ptr: */
166 
167 int bch2_btree_ptr_invalid(struct bch_fs *c, struct bkey_s_c k,
168 			   enum bkey_invalid_flags flags,
169 			   struct printbuf *err)
170 {
171 	int ret = 0;
172 
173 	bkey_fsck_err_on(bkey_val_u64s(k.k) > BCH_REPLICAS_MAX, c, err,
174 			 btree_ptr_val_too_big,
175 			 "value too big (%zu > %u)", bkey_val_u64s(k.k), BCH_REPLICAS_MAX);
176 
177 	ret = bch2_bkey_ptrs_invalid(c, k, flags, err);
178 fsck_err:
179 	return ret;
180 }
181 
182 void bch2_btree_ptr_to_text(struct printbuf *out, struct bch_fs *c,
183 			    struct bkey_s_c k)
184 {
185 	bch2_bkey_ptrs_to_text(out, c, k);
186 }
187 
188 int bch2_btree_ptr_v2_invalid(struct bch_fs *c, struct bkey_s_c k,
189 			      enum bkey_invalid_flags flags,
190 			      struct printbuf *err)
191 {
192 	int ret = 0;
193 
194 	bkey_fsck_err_on(bkey_val_u64s(k.k) > BKEY_BTREE_PTR_VAL_U64s_MAX, c, err,
195 			 btree_ptr_v2_val_too_big,
196 			 "value too big (%zu > %zu)",
197 			 bkey_val_u64s(k.k), BKEY_BTREE_PTR_VAL_U64s_MAX);
198 
199 	ret = bch2_bkey_ptrs_invalid(c, k, flags, err);
200 fsck_err:
201 	return ret;
202 }
203 
204 void bch2_btree_ptr_v2_to_text(struct printbuf *out, struct bch_fs *c,
205 			       struct bkey_s_c k)
206 {
207 	struct bkey_s_c_btree_ptr_v2 bp = bkey_s_c_to_btree_ptr_v2(k);
208 
209 	prt_printf(out, "seq %llx written %u min_key %s",
210 	       le64_to_cpu(bp.v->seq),
211 	       le16_to_cpu(bp.v->sectors_written),
212 	       BTREE_PTR_RANGE_UPDATED(bp.v) ? "R " : "");
213 
214 	bch2_bpos_to_text(out, bp.v->min_key);
215 	prt_printf(out, " ");
216 	bch2_bkey_ptrs_to_text(out, c, k);
217 }
218 
219 void bch2_btree_ptr_v2_compat(enum btree_id btree_id, unsigned version,
220 			      unsigned big_endian, int write,
221 			      struct bkey_s k)
222 {
223 	struct bkey_s_btree_ptr_v2 bp = bkey_s_to_btree_ptr_v2(k);
224 
225 	compat_bpos(0, btree_id, version, big_endian, write, &bp.v->min_key);
226 
227 	if (version < bcachefs_metadata_version_inode_btree_change &&
228 	    btree_id_is_extents(btree_id) &&
229 	    !bkey_eq(bp.v->min_key, POS_MIN))
230 		bp.v->min_key = write
231 			? bpos_nosnap_predecessor(bp.v->min_key)
232 			: bpos_nosnap_successor(bp.v->min_key);
233 }
234 
235 /* KEY_TYPE_extent: */
236 
237 bool bch2_extent_merge(struct bch_fs *c, struct bkey_s l, struct bkey_s_c r)
238 {
239 	struct bkey_ptrs   l_ptrs = bch2_bkey_ptrs(l);
240 	struct bkey_ptrs_c r_ptrs = bch2_bkey_ptrs_c(r);
241 	union bch_extent_entry *en_l;
242 	const union bch_extent_entry *en_r;
243 	struct extent_ptr_decoded lp, rp;
244 	bool use_right_ptr;
245 	struct bch_dev *ca;
246 
247 	en_l = l_ptrs.start;
248 	en_r = r_ptrs.start;
249 	while (en_l < l_ptrs.end && en_r < r_ptrs.end) {
250 		if (extent_entry_type(en_l) != extent_entry_type(en_r))
251 			return false;
252 
253 		en_l = extent_entry_next(en_l);
254 		en_r = extent_entry_next(en_r);
255 	}
256 
257 	if (en_l < l_ptrs.end || en_r < r_ptrs.end)
258 		return false;
259 
260 	en_l = l_ptrs.start;
261 	en_r = r_ptrs.start;
262 	lp.crc = bch2_extent_crc_unpack(l.k, NULL);
263 	rp.crc = bch2_extent_crc_unpack(r.k, NULL);
264 
265 	while (__bkey_ptr_next_decode(l.k, l_ptrs.end, lp, en_l) &&
266 	       __bkey_ptr_next_decode(r.k, r_ptrs.end, rp, en_r)) {
267 		if (lp.ptr.offset + lp.crc.offset + lp.crc.live_size !=
268 		    rp.ptr.offset + rp.crc.offset ||
269 		    lp.ptr.dev			!= rp.ptr.dev ||
270 		    lp.ptr.gen			!= rp.ptr.gen ||
271 		    lp.ptr.unwritten		!= rp.ptr.unwritten ||
272 		    lp.has_ec			!= rp.has_ec)
273 			return false;
274 
275 		/* Extents may not straddle buckets: */
276 		ca = bch_dev_bkey_exists(c, lp.ptr.dev);
277 		if (PTR_BUCKET_NR(ca, &lp.ptr) != PTR_BUCKET_NR(ca, &rp.ptr))
278 			return false;
279 
280 		if (lp.has_ec			!= rp.has_ec ||
281 		    (lp.has_ec &&
282 		     (lp.ec.block		!= rp.ec.block ||
283 		      lp.ec.redundancy		!= rp.ec.redundancy ||
284 		      lp.ec.idx			!= rp.ec.idx)))
285 			return false;
286 
287 		if (lp.crc.compression_type	!= rp.crc.compression_type ||
288 		    lp.crc.nonce		!= rp.crc.nonce)
289 			return false;
290 
291 		if (lp.crc.offset + lp.crc.live_size + rp.crc.live_size <=
292 		    lp.crc.uncompressed_size) {
293 			/* can use left extent's crc entry */
294 		} else if (lp.crc.live_size <= rp.crc.offset) {
295 			/* can use right extent's crc entry */
296 		} else {
297 			/* check if checksums can be merged: */
298 			if (lp.crc.csum_type		!= rp.crc.csum_type ||
299 			    lp.crc.nonce		!= rp.crc.nonce ||
300 			    crc_is_compressed(lp.crc) ||
301 			    !bch2_checksum_mergeable(lp.crc.csum_type))
302 				return false;
303 
304 			if (lp.crc.offset + lp.crc.live_size != lp.crc.compressed_size ||
305 			    rp.crc.offset)
306 				return false;
307 
308 			if (lp.crc.csum_type &&
309 			    lp.crc.uncompressed_size +
310 			    rp.crc.uncompressed_size > (c->opts.encoded_extent_max >> 9))
311 				return false;
312 		}
313 
314 		en_l = extent_entry_next(en_l);
315 		en_r = extent_entry_next(en_r);
316 	}
317 
318 	en_l = l_ptrs.start;
319 	en_r = r_ptrs.start;
320 	while (en_l < l_ptrs.end && en_r < r_ptrs.end) {
321 		if (extent_entry_is_crc(en_l)) {
322 			struct bch_extent_crc_unpacked crc_l = bch2_extent_crc_unpack(l.k, entry_to_crc(en_l));
323 			struct bch_extent_crc_unpacked crc_r = bch2_extent_crc_unpack(r.k, entry_to_crc(en_r));
324 
325 			if (crc_l.uncompressed_size + crc_r.uncompressed_size >
326 			    bch2_crc_field_size_max[extent_entry_type(en_l)])
327 				return false;
328 		}
329 
330 		en_l = extent_entry_next(en_l);
331 		en_r = extent_entry_next(en_r);
332 	}
333 
334 	use_right_ptr = false;
335 	en_l = l_ptrs.start;
336 	en_r = r_ptrs.start;
337 	while (en_l < l_ptrs.end) {
338 		if (extent_entry_type(en_l) == BCH_EXTENT_ENTRY_ptr &&
339 		    use_right_ptr)
340 			en_l->ptr = en_r->ptr;
341 
342 		if (extent_entry_is_crc(en_l)) {
343 			struct bch_extent_crc_unpacked crc_l =
344 				bch2_extent_crc_unpack(l.k, entry_to_crc(en_l));
345 			struct bch_extent_crc_unpacked crc_r =
346 				bch2_extent_crc_unpack(r.k, entry_to_crc(en_r));
347 
348 			use_right_ptr = false;
349 
350 			if (crc_l.offset + crc_l.live_size + crc_r.live_size <=
351 			    crc_l.uncompressed_size) {
352 				/* can use left extent's crc entry */
353 			} else if (crc_l.live_size <= crc_r.offset) {
354 				/* can use right extent's crc entry */
355 				crc_r.offset -= crc_l.live_size;
356 				bch2_extent_crc_pack(entry_to_crc(en_l), crc_r,
357 						     extent_entry_type(en_l));
358 				use_right_ptr = true;
359 			} else {
360 				crc_l.csum = bch2_checksum_merge(crc_l.csum_type,
361 								 crc_l.csum,
362 								 crc_r.csum,
363 								 crc_r.uncompressed_size << 9);
364 
365 				crc_l.uncompressed_size	+= crc_r.uncompressed_size;
366 				crc_l.compressed_size	+= crc_r.compressed_size;
367 				bch2_extent_crc_pack(entry_to_crc(en_l), crc_l,
368 						     extent_entry_type(en_l));
369 			}
370 		}
371 
372 		en_l = extent_entry_next(en_l);
373 		en_r = extent_entry_next(en_r);
374 	}
375 
376 	bch2_key_resize(l.k, l.k->size + r.k->size);
377 	return true;
378 }
379 
380 /* KEY_TYPE_reservation: */
381 
382 int bch2_reservation_invalid(struct bch_fs *c, struct bkey_s_c k,
383 			     enum bkey_invalid_flags flags,
384 			     struct printbuf *err)
385 {
386 	struct bkey_s_c_reservation r = bkey_s_c_to_reservation(k);
387 	int ret = 0;
388 
389 	bkey_fsck_err_on(!r.v->nr_replicas || r.v->nr_replicas > BCH_REPLICAS_MAX, c, err,
390 			 reservation_key_nr_replicas_invalid,
391 			 "invalid nr_replicas (%u)", r.v->nr_replicas);
392 fsck_err:
393 	return ret;
394 }
395 
396 void bch2_reservation_to_text(struct printbuf *out, struct bch_fs *c,
397 			      struct bkey_s_c k)
398 {
399 	struct bkey_s_c_reservation r = bkey_s_c_to_reservation(k);
400 
401 	prt_printf(out, "generation %u replicas %u",
402 	       le32_to_cpu(r.v->generation),
403 	       r.v->nr_replicas);
404 }
405 
406 bool bch2_reservation_merge(struct bch_fs *c, struct bkey_s _l, struct bkey_s_c _r)
407 {
408 	struct bkey_s_reservation l = bkey_s_to_reservation(_l);
409 	struct bkey_s_c_reservation r = bkey_s_c_to_reservation(_r);
410 
411 	if (l.v->generation != r.v->generation ||
412 	    l.v->nr_replicas != r.v->nr_replicas)
413 		return false;
414 
415 	bch2_key_resize(l.k, l.k->size + r.k->size);
416 	return true;
417 }
418 
419 /* Extent checksum entries: */
420 
421 /* returns true if not equal */
422 static inline bool bch2_crc_unpacked_cmp(struct bch_extent_crc_unpacked l,
423 					 struct bch_extent_crc_unpacked r)
424 {
425 	return (l.csum_type		!= r.csum_type ||
426 		l.compression_type	!= r.compression_type ||
427 		l.compressed_size	!= r.compressed_size ||
428 		l.uncompressed_size	!= r.uncompressed_size ||
429 		l.offset		!= r.offset ||
430 		l.live_size		!= r.live_size ||
431 		l.nonce			!= r.nonce ||
432 		bch2_crc_cmp(l.csum, r.csum));
433 }
434 
435 static inline bool can_narrow_crc(struct bch_extent_crc_unpacked u,
436 				  struct bch_extent_crc_unpacked n)
437 {
438 	return !crc_is_compressed(u) &&
439 		u.csum_type &&
440 		u.uncompressed_size > u.live_size &&
441 		bch2_csum_type_is_encryption(u.csum_type) ==
442 		bch2_csum_type_is_encryption(n.csum_type);
443 }
444 
445 bool bch2_can_narrow_extent_crcs(struct bkey_s_c k,
446 				 struct bch_extent_crc_unpacked n)
447 {
448 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
449 	struct bch_extent_crc_unpacked crc;
450 	const union bch_extent_entry *i;
451 
452 	if (!n.csum_type)
453 		return false;
454 
455 	bkey_for_each_crc(k.k, ptrs, crc, i)
456 		if (can_narrow_crc(crc, n))
457 			return true;
458 
459 	return false;
460 }
461 
462 /*
463  * We're writing another replica for this extent, so while we've got the data in
464  * memory we'll be computing a new checksum for the currently live data.
465  *
466  * If there are other replicas we aren't moving, and they are checksummed but
467  * not compressed, we can modify them to point to only the data that is
468  * currently live (so that readers won't have to bounce) while we've got the
469  * checksum we need:
470  */
471 bool bch2_bkey_narrow_crcs(struct bkey_i *k, struct bch_extent_crc_unpacked n)
472 {
473 	struct bkey_ptrs ptrs = bch2_bkey_ptrs(bkey_i_to_s(k));
474 	struct bch_extent_crc_unpacked u;
475 	struct extent_ptr_decoded p;
476 	union bch_extent_entry *i;
477 	bool ret = false;
478 
479 	/* Find a checksum entry that covers only live data: */
480 	if (!n.csum_type) {
481 		bkey_for_each_crc(&k->k, ptrs, u, i)
482 			if (!crc_is_compressed(u) &&
483 			    u.csum_type &&
484 			    u.live_size == u.uncompressed_size) {
485 				n = u;
486 				goto found;
487 			}
488 		return false;
489 	}
490 found:
491 	BUG_ON(crc_is_compressed(n));
492 	BUG_ON(n.offset);
493 	BUG_ON(n.live_size != k->k.size);
494 
495 restart_narrow_pointers:
496 	ptrs = bch2_bkey_ptrs(bkey_i_to_s(k));
497 
498 	bkey_for_each_ptr_decode(&k->k, ptrs, p, i)
499 		if (can_narrow_crc(p.crc, n)) {
500 			bch2_bkey_drop_ptr_noerror(bkey_i_to_s(k), &i->ptr);
501 			p.ptr.offset += p.crc.offset;
502 			p.crc = n;
503 			bch2_extent_ptr_decoded_append(k, &p);
504 			ret = true;
505 			goto restart_narrow_pointers;
506 		}
507 
508 	return ret;
509 }
510 
511 static void bch2_extent_crc_pack(union bch_extent_crc *dst,
512 				 struct bch_extent_crc_unpacked src,
513 				 enum bch_extent_entry_type type)
514 {
515 #define set_common_fields(_dst, _src)					\
516 		_dst.type		= 1 << type;			\
517 		_dst.csum_type		= _src.csum_type,		\
518 		_dst.compression_type	= _src.compression_type,	\
519 		_dst._compressed_size	= _src.compressed_size - 1,	\
520 		_dst._uncompressed_size	= _src.uncompressed_size - 1,	\
521 		_dst.offset		= _src.offset
522 
523 	switch (type) {
524 	case BCH_EXTENT_ENTRY_crc32:
525 		set_common_fields(dst->crc32, src);
526 		dst->crc32.csum		= (u32 __force) *((__le32 *) &src.csum.lo);
527 		break;
528 	case BCH_EXTENT_ENTRY_crc64:
529 		set_common_fields(dst->crc64, src);
530 		dst->crc64.nonce	= src.nonce;
531 		dst->crc64.csum_lo	= (u64 __force) src.csum.lo;
532 		dst->crc64.csum_hi	= (u64 __force) *((__le16 *) &src.csum.hi);
533 		break;
534 	case BCH_EXTENT_ENTRY_crc128:
535 		set_common_fields(dst->crc128, src);
536 		dst->crc128.nonce	= src.nonce;
537 		dst->crc128.csum	= src.csum;
538 		break;
539 	default:
540 		BUG();
541 	}
542 #undef set_common_fields
543 }
544 
545 void bch2_extent_crc_append(struct bkey_i *k,
546 			    struct bch_extent_crc_unpacked new)
547 {
548 	struct bkey_ptrs ptrs = bch2_bkey_ptrs(bkey_i_to_s(k));
549 	union bch_extent_crc *crc = (void *) ptrs.end;
550 	enum bch_extent_entry_type type;
551 
552 	if (bch_crc_bytes[new.csum_type]	<= 4 &&
553 	    new.uncompressed_size		<= CRC32_SIZE_MAX &&
554 	    new.nonce				<= CRC32_NONCE_MAX)
555 		type = BCH_EXTENT_ENTRY_crc32;
556 	else if (bch_crc_bytes[new.csum_type]	<= 10 &&
557 		   new.uncompressed_size	<= CRC64_SIZE_MAX &&
558 		   new.nonce			<= CRC64_NONCE_MAX)
559 		type = BCH_EXTENT_ENTRY_crc64;
560 	else if (bch_crc_bytes[new.csum_type]	<= 16 &&
561 		   new.uncompressed_size	<= CRC128_SIZE_MAX &&
562 		   new.nonce			<= CRC128_NONCE_MAX)
563 		type = BCH_EXTENT_ENTRY_crc128;
564 	else
565 		BUG();
566 
567 	bch2_extent_crc_pack(crc, new, type);
568 
569 	k->k.u64s += extent_entry_u64s(ptrs.end);
570 
571 	EBUG_ON(bkey_val_u64s(&k->k) > BKEY_EXTENT_VAL_U64s_MAX);
572 }
573 
574 /* Generic code for keys with pointers: */
575 
576 unsigned bch2_bkey_nr_ptrs(struct bkey_s_c k)
577 {
578 	return bch2_bkey_devs(k).nr;
579 }
580 
581 unsigned bch2_bkey_nr_ptrs_allocated(struct bkey_s_c k)
582 {
583 	return k.k->type == KEY_TYPE_reservation
584 		? bkey_s_c_to_reservation(k).v->nr_replicas
585 		: bch2_bkey_dirty_devs(k).nr;
586 }
587 
588 unsigned bch2_bkey_nr_ptrs_fully_allocated(struct bkey_s_c k)
589 {
590 	unsigned ret = 0;
591 
592 	if (k.k->type == KEY_TYPE_reservation) {
593 		ret = bkey_s_c_to_reservation(k).v->nr_replicas;
594 	} else {
595 		struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
596 		const union bch_extent_entry *entry;
597 		struct extent_ptr_decoded p;
598 
599 		bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
600 			ret += !p.ptr.cached && !crc_is_compressed(p.crc);
601 	}
602 
603 	return ret;
604 }
605 
606 unsigned bch2_bkey_sectors_compressed(struct bkey_s_c k)
607 {
608 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
609 	const union bch_extent_entry *entry;
610 	struct extent_ptr_decoded p;
611 	unsigned ret = 0;
612 
613 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
614 		if (!p.ptr.cached && crc_is_compressed(p.crc))
615 			ret += p.crc.compressed_size;
616 
617 	return ret;
618 }
619 
620 bool bch2_bkey_is_incompressible(struct bkey_s_c k)
621 {
622 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
623 	const union bch_extent_entry *entry;
624 	struct bch_extent_crc_unpacked crc;
625 
626 	bkey_for_each_crc(k.k, ptrs, crc, entry)
627 		if (crc.compression_type == BCH_COMPRESSION_TYPE_incompressible)
628 			return true;
629 	return false;
630 }
631 
632 unsigned bch2_bkey_replicas(struct bch_fs *c, struct bkey_s_c k)
633 {
634 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
635 	const union bch_extent_entry *entry;
636 	struct extent_ptr_decoded p = { 0 };
637 	unsigned replicas = 0;
638 
639 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
640 		if (p.ptr.cached)
641 			continue;
642 
643 		if (p.has_ec)
644 			replicas += p.ec.redundancy;
645 
646 		replicas++;
647 
648 	}
649 
650 	return replicas;
651 }
652 
653 static inline unsigned __extent_ptr_durability(struct bch_dev *ca, struct extent_ptr_decoded *p)
654 {
655 	if (p->ptr.cached)
656 		return 0;
657 
658 	return p->has_ec
659 		? p->ec.redundancy + 1
660 		: ca->mi.durability;
661 }
662 
663 unsigned bch2_extent_ptr_desired_durability(struct bch_fs *c, struct extent_ptr_decoded *p)
664 {
665 	struct bch_dev *ca = bch_dev_bkey_exists(c, p->ptr.dev);
666 
667 	return __extent_ptr_durability(ca, p);
668 }
669 
670 unsigned bch2_extent_ptr_durability(struct bch_fs *c, struct extent_ptr_decoded *p)
671 {
672 	struct bch_dev *ca = bch_dev_bkey_exists(c, p->ptr.dev);
673 
674 	if (ca->mi.state == BCH_MEMBER_STATE_failed)
675 		return 0;
676 
677 	return __extent_ptr_durability(ca, p);
678 }
679 
680 unsigned bch2_bkey_durability(struct bch_fs *c, struct bkey_s_c k)
681 {
682 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
683 	const union bch_extent_entry *entry;
684 	struct extent_ptr_decoded p;
685 	unsigned durability = 0;
686 
687 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
688 		durability += bch2_extent_ptr_durability(c, &p);
689 
690 	return durability;
691 }
692 
693 static unsigned bch2_bkey_durability_safe(struct bch_fs *c, struct bkey_s_c k)
694 {
695 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
696 	const union bch_extent_entry *entry;
697 	struct extent_ptr_decoded p;
698 	unsigned durability = 0;
699 
700 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
701 		if (p.ptr.dev < c->sb.nr_devices && c->devs[p.ptr.dev])
702 			durability += bch2_extent_ptr_durability(c, &p);
703 
704 	return durability;
705 }
706 
707 void bch2_bkey_extent_entry_drop(struct bkey_i *k, union bch_extent_entry *entry)
708 {
709 	union bch_extent_entry *end = bkey_val_end(bkey_i_to_s(k));
710 	union bch_extent_entry *next = extent_entry_next(entry);
711 
712 	memmove_u64s(entry, next, (u64 *) end - (u64 *) next);
713 	k->k.u64s -= extent_entry_u64s(entry);
714 }
715 
716 void bch2_extent_ptr_decoded_append(struct bkey_i *k,
717 				    struct extent_ptr_decoded *p)
718 {
719 	struct bkey_ptrs ptrs = bch2_bkey_ptrs(bkey_i_to_s(k));
720 	struct bch_extent_crc_unpacked crc =
721 		bch2_extent_crc_unpack(&k->k, NULL);
722 	union bch_extent_entry *pos;
723 
724 	if (!bch2_crc_unpacked_cmp(crc, p->crc)) {
725 		pos = ptrs.start;
726 		goto found;
727 	}
728 
729 	bkey_for_each_crc(&k->k, ptrs, crc, pos)
730 		if (!bch2_crc_unpacked_cmp(crc, p->crc)) {
731 			pos = extent_entry_next(pos);
732 			goto found;
733 		}
734 
735 	bch2_extent_crc_append(k, p->crc);
736 	pos = bkey_val_end(bkey_i_to_s(k));
737 found:
738 	p->ptr.type = 1 << BCH_EXTENT_ENTRY_ptr;
739 	__extent_entry_insert(k, pos, to_entry(&p->ptr));
740 
741 	if (p->has_ec) {
742 		p->ec.type = 1 << BCH_EXTENT_ENTRY_stripe_ptr;
743 		__extent_entry_insert(k, pos, to_entry(&p->ec));
744 	}
745 }
746 
747 static union bch_extent_entry *extent_entry_prev(struct bkey_ptrs ptrs,
748 					  union bch_extent_entry *entry)
749 {
750 	union bch_extent_entry *i = ptrs.start;
751 
752 	if (i == entry)
753 		return NULL;
754 
755 	while (extent_entry_next(i) != entry)
756 		i = extent_entry_next(i);
757 	return i;
758 }
759 
760 /*
761  * Returns pointer to the next entry after the one being dropped:
762  */
763 union bch_extent_entry *bch2_bkey_drop_ptr_noerror(struct bkey_s k,
764 						   struct bch_extent_ptr *ptr)
765 {
766 	struct bkey_ptrs ptrs = bch2_bkey_ptrs(k);
767 	union bch_extent_entry *entry = to_entry(ptr), *next;
768 	union bch_extent_entry *ret = entry;
769 	bool drop_crc = true;
770 
771 	EBUG_ON(ptr < &ptrs.start->ptr ||
772 		ptr >= &ptrs.end->ptr);
773 	EBUG_ON(ptr->type != 1 << BCH_EXTENT_ENTRY_ptr);
774 
775 	for (next = extent_entry_next(entry);
776 	     next != ptrs.end;
777 	     next = extent_entry_next(next)) {
778 		if (extent_entry_is_crc(next)) {
779 			break;
780 		} else if (extent_entry_is_ptr(next)) {
781 			drop_crc = false;
782 			break;
783 		}
784 	}
785 
786 	extent_entry_drop(k, entry);
787 
788 	while ((entry = extent_entry_prev(ptrs, entry))) {
789 		if (extent_entry_is_ptr(entry))
790 			break;
791 
792 		if ((extent_entry_is_crc(entry) && drop_crc) ||
793 		    extent_entry_is_stripe_ptr(entry)) {
794 			ret = (void *) ret - extent_entry_bytes(entry);
795 			extent_entry_drop(k, entry);
796 		}
797 	}
798 
799 	return ret;
800 }
801 
802 union bch_extent_entry *bch2_bkey_drop_ptr(struct bkey_s k,
803 					   struct bch_extent_ptr *ptr)
804 {
805 	bool have_dirty = bch2_bkey_dirty_devs(k.s_c).nr;
806 	union bch_extent_entry *ret =
807 		bch2_bkey_drop_ptr_noerror(k, ptr);
808 
809 	/*
810 	 * If we deleted all the dirty pointers and there's still cached
811 	 * pointers, we could set the cached pointers to dirty if they're not
812 	 * stale - but to do that correctly we'd need to grab an open_bucket
813 	 * reference so that we don't race with bucket reuse:
814 	 */
815 	if (have_dirty &&
816 	    !bch2_bkey_dirty_devs(k.s_c).nr) {
817 		k.k->type = KEY_TYPE_error;
818 		set_bkey_val_u64s(k.k, 0);
819 		ret = NULL;
820 	} else if (!bch2_bkey_nr_ptrs(k.s_c)) {
821 		k.k->type = KEY_TYPE_deleted;
822 		set_bkey_val_u64s(k.k, 0);
823 		ret = NULL;
824 	}
825 
826 	return ret;
827 }
828 
829 void bch2_bkey_drop_device(struct bkey_s k, unsigned dev)
830 {
831 	struct bch_extent_ptr *ptr;
832 
833 	bch2_bkey_drop_ptrs(k, ptr, ptr->dev == dev);
834 }
835 
836 void bch2_bkey_drop_device_noerror(struct bkey_s k, unsigned dev)
837 {
838 	struct bch_extent_ptr *ptr = bch2_bkey_has_device(k, dev);
839 
840 	if (ptr)
841 		bch2_bkey_drop_ptr_noerror(k, ptr);
842 }
843 
844 const struct bch_extent_ptr *bch2_bkey_has_device_c(struct bkey_s_c k, unsigned dev)
845 {
846 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
847 
848 	bkey_for_each_ptr(ptrs, ptr)
849 		if (ptr->dev == dev)
850 			return ptr;
851 
852 	return NULL;
853 }
854 
855 bool bch2_bkey_has_target(struct bch_fs *c, struct bkey_s_c k, unsigned target)
856 {
857 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
858 
859 	bkey_for_each_ptr(ptrs, ptr)
860 		if (bch2_dev_in_target(c, ptr->dev, target) &&
861 		    (!ptr->cached ||
862 		     !ptr_stale(bch_dev_bkey_exists(c, ptr->dev), ptr)))
863 			return true;
864 
865 	return false;
866 }
867 
868 bool bch2_bkey_matches_ptr(struct bch_fs *c, struct bkey_s_c k,
869 			   struct bch_extent_ptr m, u64 offset)
870 {
871 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
872 	const union bch_extent_entry *entry;
873 	struct extent_ptr_decoded p;
874 
875 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
876 		if (p.ptr.dev	== m.dev &&
877 		    p.ptr.gen	== m.gen &&
878 		    (s64) p.ptr.offset + p.crc.offset - bkey_start_offset(k.k) ==
879 		    (s64) m.offset  - offset)
880 			return true;
881 
882 	return false;
883 }
884 
885 /*
886  * Returns true if two extents refer to the same data:
887  */
888 bool bch2_extents_match(struct bkey_s_c k1, struct bkey_s_c k2)
889 {
890 	if (k1.k->type != k2.k->type)
891 		return false;
892 
893 	if (bkey_extent_is_direct_data(k1.k)) {
894 		struct bkey_ptrs_c ptrs1 = bch2_bkey_ptrs_c(k1);
895 		struct bkey_ptrs_c ptrs2 = bch2_bkey_ptrs_c(k2);
896 		const union bch_extent_entry *entry1, *entry2;
897 		struct extent_ptr_decoded p1, p2;
898 
899 		if (bkey_extent_is_unwritten(k1) != bkey_extent_is_unwritten(k2))
900 			return false;
901 
902 		bkey_for_each_ptr_decode(k1.k, ptrs1, p1, entry1)
903 			bkey_for_each_ptr_decode(k2.k, ptrs2, p2, entry2)
904 				if (p1.ptr.dev		== p2.ptr.dev &&
905 				    p1.ptr.gen		== p2.ptr.gen &&
906 				    (s64) p1.ptr.offset + p1.crc.offset - bkey_start_offset(k1.k) ==
907 				    (s64) p2.ptr.offset + p2.crc.offset - bkey_start_offset(k2.k))
908 					return true;
909 
910 		return false;
911 	} else {
912 		/* KEY_TYPE_deleted, etc. */
913 		return true;
914 	}
915 }
916 
917 struct bch_extent_ptr *
918 bch2_extent_has_ptr(struct bkey_s_c k1, struct extent_ptr_decoded p1, struct bkey_s k2)
919 {
920 	struct bkey_ptrs ptrs2 = bch2_bkey_ptrs(k2);
921 	union bch_extent_entry *entry2;
922 	struct extent_ptr_decoded p2;
923 
924 	bkey_for_each_ptr_decode(k2.k, ptrs2, p2, entry2)
925 		if (p1.ptr.dev		== p2.ptr.dev &&
926 		    p1.ptr.gen		== p2.ptr.gen &&
927 		    (s64) p1.ptr.offset + p1.crc.offset - bkey_start_offset(k1.k) ==
928 		    (s64) p2.ptr.offset + p2.crc.offset - bkey_start_offset(k2.k))
929 			return &entry2->ptr;
930 
931 	return NULL;
932 }
933 
934 void bch2_extent_ptr_set_cached(struct bkey_s k, struct bch_extent_ptr *ptr)
935 {
936 	struct bkey_ptrs ptrs = bch2_bkey_ptrs(k);
937 	union bch_extent_entry *entry;
938 	union bch_extent_entry *ec = NULL;
939 
940 	bkey_extent_entry_for_each(ptrs, entry) {
941 		if (&entry->ptr == ptr) {
942 			ptr->cached = true;
943 			if (ec)
944 				extent_entry_drop(k, ec);
945 			return;
946 		}
947 
948 		if (extent_entry_is_stripe_ptr(entry))
949 			ec = entry;
950 		else if (extent_entry_is_ptr(entry))
951 			ec = NULL;
952 	}
953 
954 	BUG();
955 }
956 
957 /*
958  * bch_extent_normalize - clean up an extent, dropping stale pointers etc.
959  *
960  * Returns true if @k should be dropped entirely
961  *
962  * For existing keys, only called when btree nodes are being rewritten, not when
963  * they're merely being compacted/resorted in memory.
964  */
965 bool bch2_extent_normalize(struct bch_fs *c, struct bkey_s k)
966 {
967 	struct bch_extent_ptr *ptr;
968 
969 	bch2_bkey_drop_ptrs(k, ptr,
970 		ptr->cached &&
971 		ptr_stale(bch_dev_bkey_exists(c, ptr->dev), ptr));
972 
973 	return bkey_deleted(k.k);
974 }
975 
976 void bch2_bkey_ptrs_to_text(struct printbuf *out, struct bch_fs *c,
977 			    struct bkey_s_c k)
978 {
979 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
980 	const union bch_extent_entry *entry;
981 	bool first = true;
982 
983 	if (c)
984 		prt_printf(out, "durability: %u ", bch2_bkey_durability_safe(c, k));
985 
986 	bkey_extent_entry_for_each(ptrs, entry) {
987 		if (!first)
988 			prt_printf(out, " ");
989 
990 		switch (__extent_entry_type(entry)) {
991 		case BCH_EXTENT_ENTRY_ptr: {
992 			const struct bch_extent_ptr *ptr = entry_to_ptr(entry);
993 			struct bch_dev *ca = c && ptr->dev < c->sb.nr_devices && c->devs[ptr->dev]
994 				? bch_dev_bkey_exists(c, ptr->dev)
995 				: NULL;
996 
997 			if (!ca) {
998 				prt_printf(out, "ptr: %u:%llu gen %u%s", ptr->dev,
999 				       (u64) ptr->offset, ptr->gen,
1000 				       ptr->cached ? " cached" : "");
1001 			} else {
1002 				u32 offset;
1003 				u64 b = sector_to_bucket_and_offset(ca, ptr->offset, &offset);
1004 
1005 				prt_printf(out, "ptr: %u:%llu:%u gen %u",
1006 					   ptr->dev, b, offset, ptr->gen);
1007 				if (ptr->cached)
1008 					prt_str(out, " cached");
1009 				if (ptr->unwritten)
1010 					prt_str(out, " unwritten");
1011 				if (ca && ptr_stale(ca, ptr))
1012 					prt_printf(out, " stale");
1013 			}
1014 			break;
1015 		}
1016 		case BCH_EXTENT_ENTRY_crc32:
1017 		case BCH_EXTENT_ENTRY_crc64:
1018 		case BCH_EXTENT_ENTRY_crc128: {
1019 			struct bch_extent_crc_unpacked crc =
1020 				bch2_extent_crc_unpack(k.k, entry_to_crc(entry));
1021 
1022 			prt_printf(out, "crc: c_size %u size %u offset %u nonce %u csum %s compress ",
1023 			       crc.compressed_size,
1024 			       crc.uncompressed_size,
1025 			       crc.offset, crc.nonce,
1026 			       bch2_csum_types[crc.csum_type]);
1027 			bch2_prt_compression_type(out, crc.compression_type);
1028 			break;
1029 		}
1030 		case BCH_EXTENT_ENTRY_stripe_ptr: {
1031 			const struct bch_extent_stripe_ptr *ec = &entry->stripe_ptr;
1032 
1033 			prt_printf(out, "ec: idx %llu block %u",
1034 			       (u64) ec->idx, ec->block);
1035 			break;
1036 		}
1037 		case BCH_EXTENT_ENTRY_rebalance: {
1038 			const struct bch_extent_rebalance *r = &entry->rebalance;
1039 
1040 			prt_str(out, "rebalance: target ");
1041 			if (c)
1042 				bch2_target_to_text(out, c, r->target);
1043 			else
1044 				prt_printf(out, "%u", r->target);
1045 			prt_str(out, " compression ");
1046 			bch2_compression_opt_to_text(out, r->compression);
1047 			break;
1048 		}
1049 		default:
1050 			prt_printf(out, "(invalid extent entry %.16llx)", *((u64 *) entry));
1051 			return;
1052 		}
1053 
1054 		first = false;
1055 	}
1056 }
1057 
1058 static int extent_ptr_invalid(struct bch_fs *c,
1059 			      struct bkey_s_c k,
1060 			      enum bkey_invalid_flags flags,
1061 			      const struct bch_extent_ptr *ptr,
1062 			      unsigned size_ondisk,
1063 			      bool metadata,
1064 			      struct printbuf *err)
1065 {
1066 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
1067 	u64 bucket;
1068 	u32 bucket_offset;
1069 	struct bch_dev *ca;
1070 	int ret = 0;
1071 
1072 	if (!bch2_dev_exists2(c, ptr->dev)) {
1073 		/*
1074 		 * If we're in the write path this key might have already been
1075 		 * overwritten, and we could be seeing a device that doesn't
1076 		 * exist anymore due to racing with device removal:
1077 		 */
1078 		if (flags & BKEY_INVALID_WRITE)
1079 			return 0;
1080 
1081 		bkey_fsck_err(c, err, ptr_to_invalid_device,
1082 			   "pointer to invalid device (%u)", ptr->dev);
1083 	}
1084 
1085 	ca = bch_dev_bkey_exists(c, ptr->dev);
1086 	bkey_for_each_ptr(ptrs, ptr2)
1087 		bkey_fsck_err_on(ptr != ptr2 && ptr->dev == ptr2->dev, c, err,
1088 				 ptr_to_duplicate_device,
1089 				 "multiple pointers to same device (%u)", ptr->dev);
1090 
1091 	bucket = sector_to_bucket_and_offset(ca, ptr->offset, &bucket_offset);
1092 
1093 	bkey_fsck_err_on(bucket >= ca->mi.nbuckets, c, err,
1094 			 ptr_after_last_bucket,
1095 			 "pointer past last bucket (%llu > %llu)", bucket, ca->mi.nbuckets);
1096 	bkey_fsck_err_on(ptr->offset < bucket_to_sector(ca, ca->mi.first_bucket), c, err,
1097 			 ptr_before_first_bucket,
1098 			 "pointer before first bucket (%llu < %u)", bucket, ca->mi.first_bucket);
1099 	bkey_fsck_err_on(bucket_offset + size_ondisk > ca->mi.bucket_size, c, err,
1100 			 ptr_spans_multiple_buckets,
1101 			 "pointer spans multiple buckets (%u + %u > %u)",
1102 		       bucket_offset, size_ondisk, ca->mi.bucket_size);
1103 fsck_err:
1104 	return ret;
1105 }
1106 
1107 int bch2_bkey_ptrs_invalid(struct bch_fs *c, struct bkey_s_c k,
1108 			   enum bkey_invalid_flags flags,
1109 			   struct printbuf *err)
1110 {
1111 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
1112 	const union bch_extent_entry *entry;
1113 	struct bch_extent_crc_unpacked crc;
1114 	unsigned size_ondisk = k.k->size;
1115 	unsigned nonce = UINT_MAX;
1116 	unsigned nr_ptrs = 0;
1117 	bool have_written = false, have_unwritten = false, have_ec = false, crc_since_last_ptr = false;
1118 	int ret = 0;
1119 
1120 	if (bkey_is_btree_ptr(k.k))
1121 		size_ondisk = btree_sectors(c);
1122 
1123 	bkey_extent_entry_for_each(ptrs, entry) {
1124 		bkey_fsck_err_on(__extent_entry_type(entry) >= BCH_EXTENT_ENTRY_MAX, c, err,
1125 			extent_ptrs_invalid_entry,
1126 			"invalid extent entry type (got %u, max %u)",
1127 			__extent_entry_type(entry), BCH_EXTENT_ENTRY_MAX);
1128 
1129 		bkey_fsck_err_on(bkey_is_btree_ptr(k.k) &&
1130 				 !extent_entry_is_ptr(entry), c, err,
1131 				 btree_ptr_has_non_ptr,
1132 				 "has non ptr field");
1133 
1134 		switch (extent_entry_type(entry)) {
1135 		case BCH_EXTENT_ENTRY_ptr:
1136 			ret = extent_ptr_invalid(c, k, flags, &entry->ptr,
1137 						 size_ondisk, false, err);
1138 			if (ret)
1139 				return ret;
1140 
1141 			bkey_fsck_err_on(entry->ptr.cached && have_ec, c, err,
1142 					 ptr_cached_and_erasure_coded,
1143 					 "cached, erasure coded ptr");
1144 
1145 			if (!entry->ptr.unwritten)
1146 				have_written = true;
1147 			else
1148 				have_unwritten = true;
1149 
1150 			have_ec = false;
1151 			crc_since_last_ptr = false;
1152 			nr_ptrs++;
1153 			break;
1154 		case BCH_EXTENT_ENTRY_crc32:
1155 		case BCH_EXTENT_ENTRY_crc64:
1156 		case BCH_EXTENT_ENTRY_crc128:
1157 			crc = bch2_extent_crc_unpack(k.k, entry_to_crc(entry));
1158 
1159 			bkey_fsck_err_on(crc.offset + crc.live_size > crc.uncompressed_size, c, err,
1160 					 ptr_crc_uncompressed_size_too_small,
1161 					 "checksum offset + key size > uncompressed size");
1162 			bkey_fsck_err_on(!bch2_checksum_type_valid(c, crc.csum_type), c, err,
1163 					 ptr_crc_csum_type_unknown,
1164 					 "invalid checksum type");
1165 			bkey_fsck_err_on(crc.compression_type >= BCH_COMPRESSION_TYPE_NR, c, err,
1166 					 ptr_crc_compression_type_unknown,
1167 					 "invalid compression type");
1168 
1169 			if (bch2_csum_type_is_encryption(crc.csum_type)) {
1170 				if (nonce == UINT_MAX)
1171 					nonce = crc.offset + crc.nonce;
1172 				else if (nonce != crc.offset + crc.nonce)
1173 					bkey_fsck_err(c, err, ptr_crc_nonce_mismatch,
1174 						      "incorrect nonce");
1175 			}
1176 
1177 			bkey_fsck_err_on(crc_since_last_ptr, c, err,
1178 					 ptr_crc_redundant,
1179 					 "redundant crc entry");
1180 			crc_since_last_ptr = true;
1181 
1182 			bkey_fsck_err_on(crc_is_encoded(crc) &&
1183 					 (crc.uncompressed_size > c->opts.encoded_extent_max >> 9) &&
1184 					 (flags & (BKEY_INVALID_WRITE|BKEY_INVALID_COMMIT)), c, err,
1185 					 ptr_crc_uncompressed_size_too_big,
1186 					 "too large encoded extent");
1187 
1188 			size_ondisk = crc.compressed_size;
1189 			break;
1190 		case BCH_EXTENT_ENTRY_stripe_ptr:
1191 			bkey_fsck_err_on(have_ec, c, err,
1192 					 ptr_stripe_redundant,
1193 					 "redundant stripe entry");
1194 			have_ec = true;
1195 			break;
1196 		case BCH_EXTENT_ENTRY_rebalance: {
1197 			const struct bch_extent_rebalance *r = &entry->rebalance;
1198 
1199 			if (!bch2_compression_opt_valid(r->compression)) {
1200 				struct bch_compression_opt opt = __bch2_compression_decode(r->compression);
1201 				prt_printf(err, "invalid compression opt %u:%u",
1202 					   opt.type, opt.level);
1203 				return -BCH_ERR_invalid_bkey;
1204 			}
1205 			break;
1206 		}
1207 		}
1208 	}
1209 
1210 	bkey_fsck_err_on(!nr_ptrs, c, err,
1211 			 extent_ptrs_no_ptrs,
1212 			 "no ptrs");
1213 	bkey_fsck_err_on(nr_ptrs > BCH_BKEY_PTRS_MAX, c, err,
1214 			 extent_ptrs_too_many_ptrs,
1215 			 "too many ptrs: %u > %u", nr_ptrs, BCH_BKEY_PTRS_MAX);
1216 	bkey_fsck_err_on(have_written && have_unwritten, c, err,
1217 			 extent_ptrs_written_and_unwritten,
1218 			 "extent with unwritten and written ptrs");
1219 	bkey_fsck_err_on(k.k->type != KEY_TYPE_extent && have_unwritten, c, err,
1220 			 extent_ptrs_unwritten,
1221 			 "has unwritten ptrs");
1222 	bkey_fsck_err_on(crc_since_last_ptr, c, err,
1223 			 extent_ptrs_redundant_crc,
1224 			 "redundant crc entry");
1225 	bkey_fsck_err_on(have_ec, c, err,
1226 			 extent_ptrs_redundant_stripe,
1227 			 "redundant stripe entry");
1228 fsck_err:
1229 	return ret;
1230 }
1231 
1232 void bch2_ptr_swab(struct bkey_s k)
1233 {
1234 	struct bkey_ptrs ptrs = bch2_bkey_ptrs(k);
1235 	union bch_extent_entry *entry;
1236 	u64 *d;
1237 
1238 	for (d =  (u64 *) ptrs.start;
1239 	     d != (u64 *) ptrs.end;
1240 	     d++)
1241 		*d = swab64(*d);
1242 
1243 	for (entry = ptrs.start;
1244 	     entry < ptrs.end;
1245 	     entry = extent_entry_next(entry)) {
1246 		switch (extent_entry_type(entry)) {
1247 		case BCH_EXTENT_ENTRY_ptr:
1248 			break;
1249 		case BCH_EXTENT_ENTRY_crc32:
1250 			entry->crc32.csum = swab32(entry->crc32.csum);
1251 			break;
1252 		case BCH_EXTENT_ENTRY_crc64:
1253 			entry->crc64.csum_hi = swab16(entry->crc64.csum_hi);
1254 			entry->crc64.csum_lo = swab64(entry->crc64.csum_lo);
1255 			break;
1256 		case BCH_EXTENT_ENTRY_crc128:
1257 			entry->crc128.csum.hi = (__force __le64)
1258 				swab64((__force u64) entry->crc128.csum.hi);
1259 			entry->crc128.csum.lo = (__force __le64)
1260 				swab64((__force u64) entry->crc128.csum.lo);
1261 			break;
1262 		case BCH_EXTENT_ENTRY_stripe_ptr:
1263 			break;
1264 		case BCH_EXTENT_ENTRY_rebalance:
1265 			break;
1266 		}
1267 	}
1268 }
1269 
1270 const struct bch_extent_rebalance *bch2_bkey_rebalance_opts(struct bkey_s_c k)
1271 {
1272 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
1273 	const union bch_extent_entry *entry;
1274 
1275 	bkey_extent_entry_for_each(ptrs, entry)
1276 		if (__extent_entry_type(entry) == BCH_EXTENT_ENTRY_rebalance)
1277 			return &entry->rebalance;
1278 
1279 	return NULL;
1280 }
1281 
1282 unsigned bch2_bkey_ptrs_need_rebalance(struct bch_fs *c, struct bkey_s_c k,
1283 				       unsigned target, unsigned compression)
1284 {
1285 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
1286 	unsigned rewrite_ptrs = 0;
1287 
1288 	if (compression) {
1289 		unsigned compression_type = bch2_compression_opt_to_type(compression);
1290 		const union bch_extent_entry *entry;
1291 		struct extent_ptr_decoded p;
1292 		unsigned i = 0;
1293 
1294 		bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
1295 			if (p.crc.compression_type == BCH_COMPRESSION_TYPE_incompressible ||
1296 			    p.ptr.unwritten) {
1297 				rewrite_ptrs = 0;
1298 				goto incompressible;
1299 			}
1300 
1301 			if (!p.ptr.cached && p.crc.compression_type != compression_type)
1302 				rewrite_ptrs |= 1U << i;
1303 			i++;
1304 		}
1305 	}
1306 incompressible:
1307 	if (target && bch2_target_accepts_data(c, BCH_DATA_user, target)) {
1308 		unsigned i = 0;
1309 
1310 		bkey_for_each_ptr(ptrs, ptr) {
1311 			if (!ptr->cached && !bch2_dev_in_target(c, ptr->dev, target))
1312 				rewrite_ptrs |= 1U << i;
1313 			i++;
1314 		}
1315 	}
1316 
1317 	return rewrite_ptrs;
1318 }
1319 
1320 bool bch2_bkey_needs_rebalance(struct bch_fs *c, struct bkey_s_c k)
1321 {
1322 	const struct bch_extent_rebalance *r = bch2_bkey_rebalance_opts(k);
1323 
1324 	/*
1325 	 * If it's an indirect extent, we don't delete the rebalance entry when
1326 	 * done so that we know what options were applied - check if it still
1327 	 * needs work done:
1328 	 */
1329 	if (r &&
1330 	    k.k->type == KEY_TYPE_reflink_v &&
1331 	    !bch2_bkey_ptrs_need_rebalance(c, k, r->target, r->compression))
1332 		r = NULL;
1333 
1334 	return r != NULL;
1335 }
1336 
1337 int bch2_bkey_set_needs_rebalance(struct bch_fs *c, struct bkey_i *_k,
1338 				  struct bch_io_opts *opts)
1339 {
1340 	struct bkey_s k = bkey_i_to_s(_k);
1341 	struct bch_extent_rebalance *r;
1342 	unsigned target = opts->background_target;
1343 	unsigned compression = background_compression(*opts);
1344 	bool needs_rebalance;
1345 
1346 	if (!bkey_extent_is_direct_data(k.k))
1347 		return 0;
1348 
1349 	/* get existing rebalance entry: */
1350 	r = (struct bch_extent_rebalance *) bch2_bkey_rebalance_opts(k.s_c);
1351 	if (r) {
1352 		if (k.k->type == KEY_TYPE_reflink_v) {
1353 			/*
1354 			 * indirect extents: existing options take precedence,
1355 			 * so that we don't move extents back and forth if
1356 			 * they're referenced by different inodes with different
1357 			 * options:
1358 			 */
1359 			if (r->target)
1360 				target = r->target;
1361 			if (r->compression)
1362 				compression = r->compression;
1363 		}
1364 
1365 		r->target	= target;
1366 		r->compression	= compression;
1367 	}
1368 
1369 	needs_rebalance = bch2_bkey_ptrs_need_rebalance(c, k.s_c, target, compression);
1370 
1371 	if (needs_rebalance && !r) {
1372 		union bch_extent_entry *new = bkey_val_end(k);
1373 
1374 		new->rebalance.type		= 1U << BCH_EXTENT_ENTRY_rebalance;
1375 		new->rebalance.compression	= compression;
1376 		new->rebalance.target		= target;
1377 		new->rebalance.unused		= 0;
1378 		k.k->u64s += extent_entry_u64s(new);
1379 	} else if (!needs_rebalance && r && k.k->type != KEY_TYPE_reflink_v) {
1380 		/*
1381 		 * For indirect extents, don't delete the rebalance entry when
1382 		 * we're finished so that we know we specifically moved it or
1383 		 * compressed it to its current location/compression type
1384 		 */
1385 		extent_entry_drop(k, (union bch_extent_entry *) r);
1386 	}
1387 
1388 	return 0;
1389 }
1390 
1391 /* Generic extent code: */
1392 
1393 int bch2_cut_front_s(struct bpos where, struct bkey_s k)
1394 {
1395 	unsigned new_val_u64s = bkey_val_u64s(k.k);
1396 	int val_u64s_delta;
1397 	u64 sub;
1398 
1399 	if (bkey_le(where, bkey_start_pos(k.k)))
1400 		return 0;
1401 
1402 	EBUG_ON(bkey_gt(where, k.k->p));
1403 
1404 	sub = where.offset - bkey_start_offset(k.k);
1405 
1406 	k.k->size -= sub;
1407 
1408 	if (!k.k->size) {
1409 		k.k->type = KEY_TYPE_deleted;
1410 		new_val_u64s = 0;
1411 	}
1412 
1413 	switch (k.k->type) {
1414 	case KEY_TYPE_extent:
1415 	case KEY_TYPE_reflink_v: {
1416 		struct bkey_ptrs ptrs = bch2_bkey_ptrs(k);
1417 		union bch_extent_entry *entry;
1418 		bool seen_crc = false;
1419 
1420 		bkey_extent_entry_for_each(ptrs, entry) {
1421 			switch (extent_entry_type(entry)) {
1422 			case BCH_EXTENT_ENTRY_ptr:
1423 				if (!seen_crc)
1424 					entry->ptr.offset += sub;
1425 				break;
1426 			case BCH_EXTENT_ENTRY_crc32:
1427 				entry->crc32.offset += sub;
1428 				break;
1429 			case BCH_EXTENT_ENTRY_crc64:
1430 				entry->crc64.offset += sub;
1431 				break;
1432 			case BCH_EXTENT_ENTRY_crc128:
1433 				entry->crc128.offset += sub;
1434 				break;
1435 			case BCH_EXTENT_ENTRY_stripe_ptr:
1436 				break;
1437 			case BCH_EXTENT_ENTRY_rebalance:
1438 				break;
1439 			}
1440 
1441 			if (extent_entry_is_crc(entry))
1442 				seen_crc = true;
1443 		}
1444 
1445 		break;
1446 	}
1447 	case KEY_TYPE_reflink_p: {
1448 		struct bkey_s_reflink_p p = bkey_s_to_reflink_p(k);
1449 
1450 		le64_add_cpu(&p.v->idx, sub);
1451 		break;
1452 	}
1453 	case KEY_TYPE_inline_data:
1454 	case KEY_TYPE_indirect_inline_data: {
1455 		void *p = bkey_inline_data_p(k);
1456 		unsigned bytes = bkey_inline_data_bytes(k.k);
1457 
1458 		sub = min_t(u64, sub << 9, bytes);
1459 
1460 		memmove(p, p + sub, bytes - sub);
1461 
1462 		new_val_u64s -= sub >> 3;
1463 		break;
1464 	}
1465 	}
1466 
1467 	val_u64s_delta = bkey_val_u64s(k.k) - new_val_u64s;
1468 	BUG_ON(val_u64s_delta < 0);
1469 
1470 	set_bkey_val_u64s(k.k, new_val_u64s);
1471 	memset(bkey_val_end(k), 0, val_u64s_delta * sizeof(u64));
1472 	return -val_u64s_delta;
1473 }
1474 
1475 int bch2_cut_back_s(struct bpos where, struct bkey_s k)
1476 {
1477 	unsigned new_val_u64s = bkey_val_u64s(k.k);
1478 	int val_u64s_delta;
1479 	u64 len = 0;
1480 
1481 	if (bkey_ge(where, k.k->p))
1482 		return 0;
1483 
1484 	EBUG_ON(bkey_lt(where, bkey_start_pos(k.k)));
1485 
1486 	len = where.offset - bkey_start_offset(k.k);
1487 
1488 	k.k->p.offset = where.offset;
1489 	k.k->size = len;
1490 
1491 	if (!len) {
1492 		k.k->type = KEY_TYPE_deleted;
1493 		new_val_u64s = 0;
1494 	}
1495 
1496 	switch (k.k->type) {
1497 	case KEY_TYPE_inline_data:
1498 	case KEY_TYPE_indirect_inline_data:
1499 		new_val_u64s = (bkey_inline_data_offset(k.k) +
1500 				min(bkey_inline_data_bytes(k.k), k.k->size << 9)) >> 3;
1501 		break;
1502 	}
1503 
1504 	val_u64s_delta = bkey_val_u64s(k.k) - new_val_u64s;
1505 	BUG_ON(val_u64s_delta < 0);
1506 
1507 	set_bkey_val_u64s(k.k, new_val_u64s);
1508 	memset(bkey_val_end(k), 0, val_u64s_delta * sizeof(u64));
1509 	return -val_u64s_delta;
1510 }
1511