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   1// SPDX-License-Identifier: GPL-2.0
   2
   3/* erasure coding */
   4
   5#include "bcachefs.h"
   6#include "alloc_background.h"
   7#include "alloc_foreground.h"
   8#include "backpointers.h"
   9#include "bkey_buf.h"
  10#include "bset.h"
  11#include "btree_gc.h"
  12#include "btree_update.h"
  13#include "btree_write_buffer.h"
  14#include "buckets.h"
  15#include "checksum.h"
  16#include "disk_groups.h"
  17#include "ec.h"
  18#include "error.h"
  19#include "io_read.h"
  20#include "keylist.h"
  21#include "recovery.h"
  22#include "replicas.h"
  23#include "super-io.h"
  24#include "util.h"
  25
  26#include <linux/sort.h>
  27
  28#ifdef __KERNEL__
  29
  30#include <linux/raid/pq.h>
  31#include <linux/raid/xor.h>
  32
  33static void raid5_recov(unsigned disks, unsigned failed_idx,
  34			size_t size, void **data)
  35{
  36	unsigned i = 2, nr;
  37
  38	BUG_ON(failed_idx >= disks);
  39
  40	swap(data[0], data[failed_idx]);
  41	memcpy(data[0], data[1], size);
  42
  43	while (i < disks) {
  44		nr = min_t(unsigned, disks - i, MAX_XOR_BLOCKS);
  45		xor_blocks(nr, size, data[0], data + i);
  46		i += nr;
  47	}
  48
  49	swap(data[0], data[failed_idx]);
  50}
  51
  52static void raid_gen(int nd, int np, size_t size, void **v)
  53{
  54	if (np >= 1)
  55		raid5_recov(nd + np, nd, size, v);
  56	if (np >= 2)
  57		raid6_call.gen_syndrome(nd + np, size, v);
  58	BUG_ON(np > 2);
  59}
  60
  61static void raid_rec(int nr, int *ir, int nd, int np, size_t size, void **v)
  62{
  63	switch (nr) {
  64	case 0:
  65		break;
  66	case 1:
  67		if (ir[0] < nd + 1)
  68			raid5_recov(nd + 1, ir[0], size, v);
  69		else
  70			raid6_call.gen_syndrome(nd + np, size, v);
  71		break;
  72	case 2:
  73		if (ir[1] < nd) {
  74			/* data+data failure. */
  75			raid6_2data_recov(nd + np, size, ir[0], ir[1], v);
  76		} else if (ir[0] < nd) {
  77			/* data + p/q failure */
  78
  79			if (ir[1] == nd) /* data + p failure */
  80				raid6_datap_recov(nd + np, size, ir[0], v);
  81			else { /* data + q failure */
  82				raid5_recov(nd + 1, ir[0], size, v);
  83				raid6_call.gen_syndrome(nd + np, size, v);
  84			}
  85		} else {
  86			raid_gen(nd, np, size, v);
  87		}
  88		break;
  89	default:
  90		BUG();
  91	}
  92}
  93
  94#else
  95
  96#include <raid/raid.h>
  97
  98#endif
  99
 100struct ec_bio {
 101	struct bch_dev		*ca;
 102	struct ec_stripe_buf	*buf;
 103	size_t			idx;
 104	struct bio		bio;
 105};
 106
 107/* Stripes btree keys: */
 108
 109int bch2_stripe_invalid(struct bch_fs *c, struct bkey_s_c k,
 110			enum bkey_invalid_flags flags,
 111			struct printbuf *err)
 112{
 113	const struct bch_stripe *s = bkey_s_c_to_stripe(k).v;
 114	int ret = 0;
 115
 116	bkey_fsck_err_on(bkey_eq(k.k->p, POS_MIN) ||
 117			 bpos_gt(k.k->p, POS(0, U32_MAX)), c, err,
 118			 stripe_pos_bad,
 119			 "stripe at bad pos");
 120
 121	bkey_fsck_err_on(bkey_val_u64s(k.k) < stripe_val_u64s(s), c, err,
 122			 stripe_val_size_bad,
 123			 "incorrect value size (%zu < %u)",
 124			 bkey_val_u64s(k.k), stripe_val_u64s(s));
 125
 126	ret = bch2_bkey_ptrs_invalid(c, k, flags, err);
 127fsck_err:
 128	return ret;
 129}
 130
 131void bch2_stripe_to_text(struct printbuf *out, struct bch_fs *c,
 132			 struct bkey_s_c k)
 133{
 134	const struct bch_stripe *s = bkey_s_c_to_stripe(k).v;
 135	unsigned i, nr_data = s->nr_blocks - s->nr_redundant;
 136
 137	prt_printf(out, "algo %u sectors %u blocks %u:%u csum %u gran %u",
 138	       s->algorithm,
 139	       le16_to_cpu(s->sectors),
 140	       nr_data,
 141	       s->nr_redundant,
 142	       s->csum_type,
 143	       1U << s->csum_granularity_bits);
 144
 145	for (i = 0; i < s->nr_blocks; i++) {
 146		const struct bch_extent_ptr *ptr = s->ptrs + i;
 147		struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
 148		u32 offset;
 149		u64 b = sector_to_bucket_and_offset(ca, ptr->offset, &offset);
 150
 151		prt_printf(out, " %u:%llu:%u", ptr->dev, b, offset);
 152		if (i < nr_data)
 153			prt_printf(out, "#%u", stripe_blockcount_get(s, i));
 154		prt_printf(out, " gen %u", ptr->gen);
 155		if (ptr_stale(ca, ptr))
 156			prt_printf(out, " stale");
 157	}
 158}
 159
 160/* Triggers: */
 161
 162static int bch2_trans_mark_stripe_bucket(struct btree_trans *trans,
 163					 struct bkey_s_c_stripe s,
 164					 unsigned idx, bool deleting)
 165{
 166	struct bch_fs *c = trans->c;
 167	const struct bch_extent_ptr *ptr = &s.v->ptrs[idx];
 168	struct btree_iter iter;
 169	struct bkey_i_alloc_v4 *a;
 170	enum bch_data_type data_type = idx >= s.v->nr_blocks - s.v->nr_redundant
 171		? BCH_DATA_parity : 0;
 172	s64 sectors = data_type ? le16_to_cpu(s.v->sectors) : 0;
 173	int ret = 0;
 174
 175	if (deleting)
 176		sectors = -sectors;
 177
 178	a = bch2_trans_start_alloc_update(trans, &iter, PTR_BUCKET_POS(c, ptr));
 179	if (IS_ERR(a))
 180		return PTR_ERR(a);
 181
 182	ret = bch2_check_bucket_ref(trans, s.s_c, ptr, sectors, data_type,
 183				    a->v.gen, a->v.data_type,
 184				    a->v.dirty_sectors);
 185	if (ret)
 186		goto err;
 187
 188	if (!deleting) {
 189		if (bch2_trans_inconsistent_on(a->v.stripe ||
 190					       a->v.stripe_redundancy, trans,
 191				"bucket %llu:%llu gen %u data type %s dirty_sectors %u: multiple stripes using same bucket (%u, %llu)",
 192				iter.pos.inode, iter.pos.offset, a->v.gen,
 193				bch2_data_type_str(a->v.data_type),
 194				a->v.dirty_sectors,
 195				a->v.stripe, s.k->p.offset)) {
 196			ret = -EIO;
 197			goto err;
 198		}
 199
 200		if (bch2_trans_inconsistent_on(data_type && a->v.dirty_sectors, trans,
 201				"bucket %llu:%llu gen %u data type %s dirty_sectors %u: data already in stripe bucket %llu",
 202				iter.pos.inode, iter.pos.offset, a->v.gen,
 203				bch2_data_type_str(a->v.data_type),
 204				a->v.dirty_sectors,
 205				s.k->p.offset)) {
 206			ret = -EIO;
 207			goto err;
 208		}
 209
 210		a->v.stripe		= s.k->p.offset;
 211		a->v.stripe_redundancy	= s.v->nr_redundant;
 212		a->v.data_type		= BCH_DATA_stripe;
 213	} else {
 214		if (bch2_trans_inconsistent_on(a->v.stripe != s.k->p.offset ||
 215					       a->v.stripe_redundancy != s.v->nr_redundant, trans,
 216				"bucket %llu:%llu gen %u: not marked as stripe when deleting stripe %llu (got %u)",
 217				iter.pos.inode, iter.pos.offset, a->v.gen,
 218				s.k->p.offset, a->v.stripe)) {
 219			ret = -EIO;
 220			goto err;
 221		}
 222
 223		a->v.stripe		= 0;
 224		a->v.stripe_redundancy	= 0;
 225		a->v.data_type		= alloc_data_type(a->v, BCH_DATA_user);
 226	}
 227
 228	a->v.dirty_sectors += sectors;
 229	if (data_type)
 230		a->v.data_type = !deleting ? data_type : 0;
 231
 232	ret = bch2_trans_update(trans, &iter, &a->k_i, 0);
 233	if (ret)
 234		goto err;
 235err:
 236	bch2_trans_iter_exit(trans, &iter);
 237	return ret;
 238}
 239
 240static int mark_stripe_bucket(struct btree_trans *trans,
 241			      struct bkey_s_c k,
 242			      unsigned ptr_idx,
 243			      unsigned flags)
 244{
 245	struct bch_fs *c = trans->c;
 246	const struct bch_stripe *s = bkey_s_c_to_stripe(k).v;
 247	unsigned nr_data = s->nr_blocks - s->nr_redundant;
 248	bool parity = ptr_idx >= nr_data;
 249	enum bch_data_type data_type = parity ? BCH_DATA_parity : BCH_DATA_stripe;
 250	s64 sectors = parity ? le16_to_cpu(s->sectors) : 0;
 251	const struct bch_extent_ptr *ptr = s->ptrs + ptr_idx;
 252	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
 253	struct bucket old, new, *g;
 254	struct printbuf buf = PRINTBUF;
 255	int ret = 0;
 256
 257	BUG_ON(!(flags & BTREE_TRIGGER_GC));
 258
 259	/* * XXX doesn't handle deletion */
 260
 261	percpu_down_read(&c->mark_lock);
 262	g = PTR_GC_BUCKET(ca, ptr);
 263
 264	if (g->dirty_sectors ||
 265	    (g->stripe && g->stripe != k.k->p.offset)) {
 266		bch2_fs_inconsistent(c,
 267			      "bucket %u:%zu gen %u: multiple stripes using same bucket\n%s",
 268			      ptr->dev, PTR_BUCKET_NR(ca, ptr), g->gen,
 269			      (bch2_bkey_val_to_text(&buf, c, k), buf.buf));
 270		ret = -EINVAL;
 271		goto err;
 272	}
 273
 274	bucket_lock(g);
 275	old = *g;
 276
 277	ret = bch2_check_bucket_ref(trans, k, ptr, sectors, data_type,
 278				    g->gen, g->data_type,
 279				    g->dirty_sectors);
 280	if (ret)
 281		goto err;
 282
 283	g->data_type = data_type;
 284	g->dirty_sectors += sectors;
 285
 286	g->stripe		= k.k->p.offset;
 287	g->stripe_redundancy	= s->nr_redundant;
 288	new = *g;
 289err:
 290	bucket_unlock(g);
 291	if (!ret)
 292		bch2_dev_usage_update_m(c, ca, &old, &new);
 293	percpu_up_read(&c->mark_lock);
 294	printbuf_exit(&buf);
 295	return ret;
 296}
 297
 298int bch2_trigger_stripe(struct btree_trans *trans,
 299			enum btree_id btree_id, unsigned level,
 300			struct bkey_s_c old, struct bkey_s _new,
 301			unsigned flags)
 302{
 303	struct bkey_s_c new = _new.s_c;
 304	struct bch_fs *c = trans->c;
 305	u64 idx = new.k->p.offset;
 306	const struct bch_stripe *old_s = old.k->type == KEY_TYPE_stripe
 307		? bkey_s_c_to_stripe(old).v : NULL;
 308	const struct bch_stripe *new_s = new.k->type == KEY_TYPE_stripe
 309		? bkey_s_c_to_stripe(new).v : NULL;
 310
 311	if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
 312		/*
 313		 * If the pointers aren't changing, we don't need to do anything:
 314		 */
 315		if (new_s && old_s &&
 316		    new_s->nr_blocks	== old_s->nr_blocks &&
 317		    new_s->nr_redundant	== old_s->nr_redundant &&
 318		    !memcmp(old_s->ptrs, new_s->ptrs,
 319			    new_s->nr_blocks * sizeof(struct bch_extent_ptr)))
 320			return 0;
 321
 322		BUG_ON(new_s && old_s &&
 323		       (new_s->nr_blocks	!= old_s->nr_blocks ||
 324			new_s->nr_redundant	!= old_s->nr_redundant));
 325
 326		if (new_s) {
 327			s64 sectors = le16_to_cpu(new_s->sectors);
 328
 329			struct bch_replicas_padded r;
 330			bch2_bkey_to_replicas(&r.e, new);
 331			int ret = bch2_update_replicas_list(trans, &r.e, sectors * new_s->nr_redundant);
 332			if (ret)
 333				return ret;
 334		}
 335
 336		if (old_s) {
 337			s64 sectors = -((s64) le16_to_cpu(old_s->sectors));
 338
 339			struct bch_replicas_padded r;
 340			bch2_bkey_to_replicas(&r.e, old);
 341			int ret = bch2_update_replicas_list(trans, &r.e, sectors * old_s->nr_redundant);
 342			if (ret)
 343				return ret;
 344		}
 345
 346		unsigned nr_blocks = new_s ? new_s->nr_blocks : old_s->nr_blocks;
 347		for (unsigned i = 0; i < nr_blocks; i++) {
 348			if (new_s && old_s &&
 349			    !memcmp(&new_s->ptrs[i],
 350				    &old_s->ptrs[i],
 351				    sizeof(new_s->ptrs[i])))
 352				continue;
 353
 354			if (new_s) {
 355				int ret = bch2_trans_mark_stripe_bucket(trans,
 356						bkey_s_c_to_stripe(new), i, false);
 357				if (ret)
 358					return ret;
 359			}
 360
 361			if (old_s) {
 362				int ret = bch2_trans_mark_stripe_bucket(trans,
 363						bkey_s_c_to_stripe(old), i, true);
 364				if (ret)
 365					return ret;
 366			}
 367		}
 368	}
 369
 370	if (flags & BTREE_TRIGGER_ATOMIC) {
 371		struct stripe *m = genradix_ptr(&c->stripes, idx);
 372
 373		if (!m) {
 374			struct printbuf buf1 = PRINTBUF;
 375			struct printbuf buf2 = PRINTBUF;
 376
 377			bch2_bkey_val_to_text(&buf1, c, old);
 378			bch2_bkey_val_to_text(&buf2, c, new);
 379			bch_err_ratelimited(c, "error marking nonexistent stripe %llu while marking\n"
 380					    "old %s\n"
 381					    "new %s", idx, buf1.buf, buf2.buf);
 382			printbuf_exit(&buf2);
 383			printbuf_exit(&buf1);
 384			bch2_inconsistent_error(c);
 385			return -1;
 386		}
 387
 388		if (!new_s) {
 389			bch2_stripes_heap_del(c, m, idx);
 390
 391			memset(m, 0, sizeof(*m));
 392		} else {
 393			m->sectors	= le16_to_cpu(new_s->sectors);
 394			m->algorithm	= new_s->algorithm;
 395			m->nr_blocks	= new_s->nr_blocks;
 396			m->nr_redundant	= new_s->nr_redundant;
 397			m->blocks_nonempty = 0;
 398
 399			for (unsigned i = 0; i < new_s->nr_blocks; i++)
 400				m->blocks_nonempty += !!stripe_blockcount_get(new_s, i);
 401
 402			if (!old_s)
 403				bch2_stripes_heap_insert(c, m, idx);
 404			else
 405				bch2_stripes_heap_update(c, m, idx);
 406		}
 407	}
 408
 409	if (flags & BTREE_TRIGGER_GC) {
 410		struct gc_stripe *m =
 411			genradix_ptr_alloc(&c->gc_stripes, idx, GFP_KERNEL);
 412
 413		if (!m) {
 414			bch_err(c, "error allocating memory for gc_stripes, idx %llu",
 415				idx);
 416			return -BCH_ERR_ENOMEM_mark_stripe;
 417		}
 418		/*
 419		 * This will be wrong when we bring back runtime gc: we should
 420		 * be unmarking the old key and then marking the new key
 421		 */
 422		m->alive	= true;
 423		m->sectors	= le16_to_cpu(new_s->sectors);
 424		m->nr_blocks	= new_s->nr_blocks;
 425		m->nr_redundant	= new_s->nr_redundant;
 426
 427		for (unsigned i = 0; i < new_s->nr_blocks; i++)
 428			m->ptrs[i] = new_s->ptrs[i];
 429
 430		bch2_bkey_to_replicas(&m->r.e, new);
 431
 432		/*
 433		 * gc recalculates this field from stripe ptr
 434		 * references:
 435		 */
 436		memset(m->block_sectors, 0, sizeof(m->block_sectors));
 437
 438		for (unsigned i = 0; i < new_s->nr_blocks; i++) {
 439			int ret = mark_stripe_bucket(trans, new, i, flags);
 440			if (ret)
 441				return ret;
 442		}
 443
 444		int ret = bch2_update_replicas(c, new, &m->r.e,
 445				      ((s64) m->sectors * m->nr_redundant),
 446				      0, true);
 447		if (ret) {
 448			struct printbuf buf = PRINTBUF;
 449
 450			bch2_bkey_val_to_text(&buf, c, new);
 451			bch2_fs_fatal_error(c, "no replicas entry for %s", buf.buf);
 452			printbuf_exit(&buf);
 453			return ret;
 454		}
 455	}
 456
 457	return 0;
 458}
 459
 460/* returns blocknr in stripe that we matched: */
 461static const struct bch_extent_ptr *bkey_matches_stripe(struct bch_stripe *s,
 462						struct bkey_s_c k, unsigned *block)
 463{
 464	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
 465	unsigned i, nr_data = s->nr_blocks - s->nr_redundant;
 466
 467	bkey_for_each_ptr(ptrs, ptr)
 468		for (i = 0; i < nr_data; i++)
 469			if (__bch2_ptr_matches_stripe(&s->ptrs[i], ptr,
 470						      le16_to_cpu(s->sectors))) {
 471				*block = i;
 472				return ptr;
 473			}
 474
 475	return NULL;
 476}
 477
 478static bool extent_has_stripe_ptr(struct bkey_s_c k, u64 idx)
 479{
 480	switch (k.k->type) {
 481	case KEY_TYPE_extent: {
 482		struct bkey_s_c_extent e = bkey_s_c_to_extent(k);
 483		const union bch_extent_entry *entry;
 484
 485		extent_for_each_entry(e, entry)
 486			if (extent_entry_type(entry) ==
 487			    BCH_EXTENT_ENTRY_stripe_ptr &&
 488			    entry->stripe_ptr.idx == idx)
 489				return true;
 490
 491		break;
 492	}
 493	}
 494
 495	return false;
 496}
 497
 498/* Stripe bufs: */
 499
 500static void ec_stripe_buf_exit(struct ec_stripe_buf *buf)
 501{
 502	if (buf->key.k.type == KEY_TYPE_stripe) {
 503		struct bkey_i_stripe *s = bkey_i_to_stripe(&buf->key);
 504		unsigned i;
 505
 506		for (i = 0; i < s->v.nr_blocks; i++) {
 507			kvpfree(buf->data[i], buf->size << 9);
 508			buf->data[i] = NULL;
 509		}
 510	}
 511}
 512
 513/* XXX: this is a non-mempoolified memory allocation: */
 514static int ec_stripe_buf_init(struct ec_stripe_buf *buf,
 515			      unsigned offset, unsigned size)
 516{
 517	struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 518	unsigned csum_granularity = 1U << v->csum_granularity_bits;
 519	unsigned end = offset + size;
 520	unsigned i;
 521
 522	BUG_ON(end > le16_to_cpu(v->sectors));
 523
 524	offset	= round_down(offset, csum_granularity);
 525	end	= min_t(unsigned, le16_to_cpu(v->sectors),
 526			round_up(end, csum_granularity));
 527
 528	buf->offset	= offset;
 529	buf->size	= end - offset;
 530
 531	memset(buf->valid, 0xFF, sizeof(buf->valid));
 532
 533	for (i = 0; i < v->nr_blocks; i++) {
 534		buf->data[i] = kvpmalloc(buf->size << 9, GFP_KERNEL);
 535		if (!buf->data[i])
 536			goto err;
 537	}
 538
 539	return 0;
 540err:
 541	ec_stripe_buf_exit(buf);
 542	return -BCH_ERR_ENOMEM_stripe_buf;
 543}
 544
 545/* Checksumming: */
 546
 547static struct bch_csum ec_block_checksum(struct ec_stripe_buf *buf,
 548					 unsigned block, unsigned offset)
 549{
 550	struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 551	unsigned csum_granularity = 1 << v->csum_granularity_bits;
 552	unsigned end = buf->offset + buf->size;
 553	unsigned len = min(csum_granularity, end - offset);
 554
 555	BUG_ON(offset >= end);
 556	BUG_ON(offset <  buf->offset);
 557	BUG_ON(offset & (csum_granularity - 1));
 558	BUG_ON(offset + len != le16_to_cpu(v->sectors) &&
 559	       (len & (csum_granularity - 1)));
 560
 561	return bch2_checksum(NULL, v->csum_type,
 562			     null_nonce(),
 563			     buf->data[block] + ((offset - buf->offset) << 9),
 564			     len << 9);
 565}
 566
 567static void ec_generate_checksums(struct ec_stripe_buf *buf)
 568{
 569	struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 570	unsigned i, j, csums_per_device = stripe_csums_per_device(v);
 571
 572	if (!v->csum_type)
 573		return;
 574
 575	BUG_ON(buf->offset);
 576	BUG_ON(buf->size != le16_to_cpu(v->sectors));
 577
 578	for (i = 0; i < v->nr_blocks; i++)
 579		for (j = 0; j < csums_per_device; j++)
 580			stripe_csum_set(v, i, j,
 581				ec_block_checksum(buf, i, j << v->csum_granularity_bits));
 582}
 583
 584static void ec_validate_checksums(struct bch_fs *c, struct ec_stripe_buf *buf)
 585{
 586	struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 587	unsigned csum_granularity = 1 << v->csum_granularity_bits;
 588	unsigned i;
 589
 590	if (!v->csum_type)
 591		return;
 592
 593	for (i = 0; i < v->nr_blocks; i++) {
 594		unsigned offset = buf->offset;
 595		unsigned end = buf->offset + buf->size;
 596
 597		if (!test_bit(i, buf->valid))
 598			continue;
 599
 600		while (offset < end) {
 601			unsigned j = offset >> v->csum_granularity_bits;
 602			unsigned len = min(csum_granularity, end - offset);
 603			struct bch_csum want = stripe_csum_get(v, i, j);
 604			struct bch_csum got = ec_block_checksum(buf, i, offset);
 605
 606			if (bch2_crc_cmp(want, got)) {
 607				struct printbuf err = PRINTBUF;
 608				struct bch_dev *ca = bch_dev_bkey_exists(c, v->ptrs[i].dev);
 609
 610				prt_printf(&err, "stripe checksum error: expected %0llx:%0llx got %0llx:%0llx (type %s)\n",
 611					   want.hi, want.lo,
 612					   got.hi, got.lo,
 613					   bch2_csum_types[v->csum_type]);
 614				prt_printf(&err, "  for %ps at %u of\n  ", (void *) _RET_IP_, i);
 615				bch2_bkey_val_to_text(&err, c, bkey_i_to_s_c(&buf->key));
 616				bch_err_ratelimited(ca, "%s", err.buf);
 617				printbuf_exit(&err);
 618
 619				clear_bit(i, buf->valid);
 620
 621				bch2_io_error(ca, BCH_MEMBER_ERROR_checksum);
 622				break;
 623			}
 624
 625			offset += len;
 626		}
 627	}
 628}
 629
 630/* Erasure coding: */
 631
 632static void ec_generate_ec(struct ec_stripe_buf *buf)
 633{
 634	struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 635	unsigned nr_data = v->nr_blocks - v->nr_redundant;
 636	unsigned bytes = le16_to_cpu(v->sectors) << 9;
 637
 638	raid_gen(nr_data, v->nr_redundant, bytes, buf->data);
 639}
 640
 641static unsigned ec_nr_failed(struct ec_stripe_buf *buf)
 642{
 643	struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 644
 645	return v->nr_blocks - bitmap_weight(buf->valid, v->nr_blocks);
 646}
 647
 648static int ec_do_recov(struct bch_fs *c, struct ec_stripe_buf *buf)
 649{
 650	struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 651	unsigned i, failed[BCH_BKEY_PTRS_MAX], nr_failed = 0;
 652	unsigned nr_data = v->nr_blocks - v->nr_redundant;
 653	unsigned bytes = buf->size << 9;
 654
 655	if (ec_nr_failed(buf) > v->nr_redundant) {
 656		bch_err_ratelimited(c,
 657			"error doing reconstruct read: unable to read enough blocks");
 658		return -1;
 659	}
 660
 661	for (i = 0; i < nr_data; i++)
 662		if (!test_bit(i, buf->valid))
 663			failed[nr_failed++] = i;
 664
 665	raid_rec(nr_failed, failed, nr_data, v->nr_redundant, bytes, buf->data);
 666	return 0;
 667}
 668
 669/* IO: */
 670
 671static void ec_block_endio(struct bio *bio)
 672{
 673	struct ec_bio *ec_bio = container_of(bio, struct ec_bio, bio);
 674	struct bch_stripe *v = &bkey_i_to_stripe(&ec_bio->buf->key)->v;
 675	struct bch_extent_ptr *ptr = &v->ptrs[ec_bio->idx];
 676	struct bch_dev *ca = ec_bio->ca;
 677	struct closure *cl = bio->bi_private;
 678
 679	if (bch2_dev_io_err_on(bio->bi_status, ca,
 680			       bio_data_dir(bio)
 681			       ? BCH_MEMBER_ERROR_write
 682			       : BCH_MEMBER_ERROR_read,
 683			       "erasure coding %s error: %s",
 684			       bio_data_dir(bio) ? "write" : "read",
 685			       bch2_blk_status_to_str(bio->bi_status)))
 686		clear_bit(ec_bio->idx, ec_bio->buf->valid);
 687
 688	if (ptr_stale(ca, ptr)) {
 689		bch_err_ratelimited(ca->fs,
 690				    "error %s stripe: stale pointer after io",
 691				    bio_data_dir(bio) == READ ? "reading from" : "writing to");
 692		clear_bit(ec_bio->idx, ec_bio->buf->valid);
 693	}
 694
 695	bio_put(&ec_bio->bio);
 696	percpu_ref_put(&ca->io_ref);
 697	closure_put(cl);
 698}
 699
 700static void ec_block_io(struct bch_fs *c, struct ec_stripe_buf *buf,
 701			blk_opf_t opf, unsigned idx, struct closure *cl)
 702{
 703	struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 704	unsigned offset = 0, bytes = buf->size << 9;
 705	struct bch_extent_ptr *ptr = &v->ptrs[idx];
 706	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
 707	enum bch_data_type data_type = idx < v->nr_blocks - v->nr_redundant
 708		? BCH_DATA_user
 709		: BCH_DATA_parity;
 710	int rw = op_is_write(opf);
 711
 712	if (ptr_stale(ca, ptr)) {
 713		bch_err_ratelimited(c,
 714				    "error %s stripe: stale pointer",
 715				    rw == READ ? "reading from" : "writing to");
 716		clear_bit(idx, buf->valid);
 717		return;
 718	}
 719
 720	if (!bch2_dev_get_ioref(ca, rw)) {
 721		clear_bit(idx, buf->valid);
 722		return;
 723	}
 724
 725	this_cpu_add(ca->io_done->sectors[rw][data_type], buf->size);
 726
 727	while (offset < bytes) {
 728		unsigned nr_iovecs = min_t(size_t, BIO_MAX_VECS,
 729					   DIV_ROUND_UP(bytes, PAGE_SIZE));
 730		unsigned b = min_t(size_t, bytes - offset,
 731				   nr_iovecs << PAGE_SHIFT);
 732		struct ec_bio *ec_bio;
 733
 734		ec_bio = container_of(bio_alloc_bioset(ca->disk_sb.bdev,
 735						       nr_iovecs,
 736						       opf,
 737						       GFP_KERNEL,
 738						       &c->ec_bioset),
 739				      struct ec_bio, bio);
 740
 741		ec_bio->ca			= ca;
 742		ec_bio->buf			= buf;
 743		ec_bio->idx			= idx;
 744
 745		ec_bio->bio.bi_iter.bi_sector	= ptr->offset + buf->offset + (offset >> 9);
 746		ec_bio->bio.bi_end_io		= ec_block_endio;
 747		ec_bio->bio.bi_private		= cl;
 748
 749		bch2_bio_map(&ec_bio->bio, buf->data[idx] + offset, b);
 750
 751		closure_get(cl);
 752		percpu_ref_get(&ca->io_ref);
 753
 754		submit_bio(&ec_bio->bio);
 755
 756		offset += b;
 757	}
 758
 759	percpu_ref_put(&ca->io_ref);
 760}
 761
 762static int get_stripe_key_trans(struct btree_trans *trans, u64 idx,
 763				struct ec_stripe_buf *stripe)
 764{
 765	struct btree_iter iter;
 766	struct bkey_s_c k;
 767	int ret;
 768
 769	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_stripes,
 770			       POS(0, idx), BTREE_ITER_SLOTS);
 771	ret = bkey_err(k);
 772	if (ret)
 773		goto err;
 774	if (k.k->type != KEY_TYPE_stripe) {
 775		ret = -ENOENT;
 776		goto err;
 777	}
 778	bkey_reassemble(&stripe->key, k);
 779err:
 780	bch2_trans_iter_exit(trans, &iter);
 781	return ret;
 782}
 783
 784/* recovery read path: */
 785int bch2_ec_read_extent(struct btree_trans *trans, struct bch_read_bio *rbio)
 786{
 787	struct bch_fs *c = trans->c;
 788	struct ec_stripe_buf *buf;
 789	struct closure cl;
 790	struct bch_stripe *v;
 791	unsigned i, offset;
 792	int ret = 0;
 793
 794	closure_init_stack(&cl);
 795
 796	BUG_ON(!rbio->pick.has_ec);
 797
 798	buf = kzalloc(sizeof(*buf), GFP_NOFS);
 799	if (!buf)
 800		return -BCH_ERR_ENOMEM_ec_read_extent;
 801
 802	ret = lockrestart_do(trans, get_stripe_key_trans(trans, rbio->pick.ec.idx, buf));
 803	if (ret) {
 804		bch_err_ratelimited(c,
 805			"error doing reconstruct read: error %i looking up stripe", ret);
 806		kfree(buf);
 807		return -EIO;
 808	}
 809
 810	v = &bkey_i_to_stripe(&buf->key)->v;
 811
 812	if (!bch2_ptr_matches_stripe(v, rbio->pick)) {
 813		bch_err_ratelimited(c,
 814			"error doing reconstruct read: pointer doesn't match stripe");
 815		ret = -EIO;
 816		goto err;
 817	}
 818
 819	offset = rbio->bio.bi_iter.bi_sector - v->ptrs[rbio->pick.ec.block].offset;
 820	if (offset + bio_sectors(&rbio->bio) > le16_to_cpu(v->sectors)) {
 821		bch_err_ratelimited(c,
 822			"error doing reconstruct read: read is bigger than stripe");
 823		ret = -EIO;
 824		goto err;
 825	}
 826
 827	ret = ec_stripe_buf_init(buf, offset, bio_sectors(&rbio->bio));
 828	if (ret)
 829		goto err;
 830
 831	for (i = 0; i < v->nr_blocks; i++)
 832		ec_block_io(c, buf, REQ_OP_READ, i, &cl);
 833
 834	closure_sync(&cl);
 835
 836	if (ec_nr_failed(buf) > v->nr_redundant) {
 837		bch_err_ratelimited(c,
 838			"error doing reconstruct read: unable to read enough blocks");
 839		ret = -EIO;
 840		goto err;
 841	}
 842
 843	ec_validate_checksums(c, buf);
 844
 845	ret = ec_do_recov(c, buf);
 846	if (ret)
 847		goto err;
 848
 849	memcpy_to_bio(&rbio->bio, rbio->bio.bi_iter,
 850		      buf->data[rbio->pick.ec.block] + ((offset - buf->offset) << 9));
 851err:
 852	ec_stripe_buf_exit(buf);
 853	kfree(buf);
 854	return ret;
 855}
 856
 857/* stripe bucket accounting: */
 858
 859static int __ec_stripe_mem_alloc(struct bch_fs *c, size_t idx, gfp_t gfp)
 860{
 861	ec_stripes_heap n, *h = &c->ec_stripes_heap;
 862
 863	if (idx >= h->size) {
 864		if (!init_heap(&n, max(1024UL, roundup_pow_of_two(idx + 1)), gfp))
 865			return -BCH_ERR_ENOMEM_ec_stripe_mem_alloc;
 866
 867		mutex_lock(&c->ec_stripes_heap_lock);
 868		if (n.size > h->size) {
 869			memcpy(n.data, h->data, h->used * sizeof(h->data[0]));
 870			n.used = h->used;
 871			swap(*h, n);
 872		}
 873		mutex_unlock(&c->ec_stripes_heap_lock);
 874
 875		free_heap(&n);
 876	}
 877
 878	if (!genradix_ptr_alloc(&c->stripes, idx, gfp))
 879		return -BCH_ERR_ENOMEM_ec_stripe_mem_alloc;
 880
 881	if (c->gc_pos.phase != GC_PHASE_NOT_RUNNING &&
 882	    !genradix_ptr_alloc(&c->gc_stripes, idx, gfp))
 883		return -BCH_ERR_ENOMEM_ec_stripe_mem_alloc;
 884
 885	return 0;
 886}
 887
 888static int ec_stripe_mem_alloc(struct btree_trans *trans,
 889			       struct btree_iter *iter)
 890{
 891	return allocate_dropping_locks_errcode(trans,
 892			__ec_stripe_mem_alloc(trans->c, iter->pos.offset, _gfp));
 893}
 894
 895/*
 896 * Hash table of open stripes:
 897 * Stripes that are being created or modified are kept in a hash table, so that
 898 * stripe deletion can skip them.
 899 */
 900
 901static bool __bch2_stripe_is_open(struct bch_fs *c, u64 idx)
 902{
 903	unsigned hash = hash_64(idx, ilog2(ARRAY_SIZE(c->ec_stripes_new)));
 904	struct ec_stripe_new *s;
 905
 906	hlist_for_each_entry(s, &c->ec_stripes_new[hash], hash)
 907		if (s->idx == idx)
 908			return true;
 909	return false;
 910}
 911
 912static bool bch2_stripe_is_open(struct bch_fs *c, u64 idx)
 913{
 914	bool ret = false;
 915
 916	spin_lock(&c->ec_stripes_new_lock);
 917	ret = __bch2_stripe_is_open(c, idx);
 918	spin_unlock(&c->ec_stripes_new_lock);
 919
 920	return ret;
 921}
 922
 923static bool bch2_try_open_stripe(struct bch_fs *c,
 924				 struct ec_stripe_new *s,
 925				 u64 idx)
 926{
 927	bool ret;
 928
 929	spin_lock(&c->ec_stripes_new_lock);
 930	ret = !__bch2_stripe_is_open(c, idx);
 931	if (ret) {
 932		unsigned hash = hash_64(idx, ilog2(ARRAY_SIZE(c->ec_stripes_new)));
 933
 934		s->idx = idx;
 935		hlist_add_head(&s->hash, &c->ec_stripes_new[hash]);
 936	}
 937	spin_unlock(&c->ec_stripes_new_lock);
 938
 939	return ret;
 940}
 941
 942static void bch2_stripe_close(struct bch_fs *c, struct ec_stripe_new *s)
 943{
 944	BUG_ON(!s->idx);
 945
 946	spin_lock(&c->ec_stripes_new_lock);
 947	hlist_del_init(&s->hash);
 948	spin_unlock(&c->ec_stripes_new_lock);
 949
 950	s->idx = 0;
 951}
 952
 953/* Heap of all existing stripes, ordered by blocks_nonempty */
 954
 955static u64 stripe_idx_to_delete(struct bch_fs *c)
 956{
 957	ec_stripes_heap *h = &c->ec_stripes_heap;
 958
 959	lockdep_assert_held(&c->ec_stripes_heap_lock);
 960
 961	if (h->used &&
 962	    h->data[0].blocks_nonempty == 0 &&
 963	    !bch2_stripe_is_open(c, h->data[0].idx))
 964		return h->data[0].idx;
 965
 966	return 0;
 967}
 968
 969static inline int ec_stripes_heap_cmp(ec_stripes_heap *h,
 970				      struct ec_stripe_heap_entry l,
 971				      struct ec_stripe_heap_entry r)
 972{
 973	return ((l.blocks_nonempty > r.blocks_nonempty) -
 974		(l.blocks_nonempty < r.blocks_nonempty));
 975}
 976
 977static inline void ec_stripes_heap_set_backpointer(ec_stripes_heap *h,
 978						   size_t i)
 979{
 980	struct bch_fs *c = container_of(h, struct bch_fs, ec_stripes_heap);
 981
 982	genradix_ptr(&c->stripes, h->data[i].idx)->heap_idx = i;
 983}
 984
 985static void heap_verify_backpointer(struct bch_fs *c, size_t idx)
 986{
 987	ec_stripes_heap *h = &c->ec_stripes_heap;
 988	struct stripe *m = genradix_ptr(&c->stripes, idx);
 989
 990	BUG_ON(m->heap_idx >= h->used);
 991	BUG_ON(h->data[m->heap_idx].idx != idx);
 992}
 993
 994void bch2_stripes_heap_del(struct bch_fs *c,
 995			   struct stripe *m, size_t idx)
 996{
 997	mutex_lock(&c->ec_stripes_heap_lock);
 998	heap_verify_backpointer(c, idx);
 999
1000	heap_del(&c->ec_stripes_heap, m->heap_idx,
1001		 ec_stripes_heap_cmp,
1002		 ec_stripes_heap_set_backpointer);
1003	mutex_unlock(&c->ec_stripes_heap_lock);
1004}
1005
1006void bch2_stripes_heap_insert(struct bch_fs *c,
1007			      struct stripe *m, size_t idx)
1008{
1009	mutex_lock(&c->ec_stripes_heap_lock);
1010	BUG_ON(heap_full(&c->ec_stripes_heap));
1011
1012	heap_add(&c->ec_stripes_heap, ((struct ec_stripe_heap_entry) {
1013			.idx = idx,
1014			.blocks_nonempty = m->blocks_nonempty,
1015		}),
1016		 ec_stripes_heap_cmp,
1017		 ec_stripes_heap_set_backpointer);
1018
1019	heap_verify_backpointer(c, idx);
1020	mutex_unlock(&c->ec_stripes_heap_lock);
1021}
1022
1023void bch2_stripes_heap_update(struct bch_fs *c,
1024			      struct stripe *m, size_t idx)
1025{
1026	ec_stripes_heap *h = &c->ec_stripes_heap;
1027	bool do_deletes;
1028	size_t i;
1029
1030	mutex_lock(&c->ec_stripes_heap_lock);
1031	heap_verify_backpointer(c, idx);
1032
1033	h->data[m->heap_idx].blocks_nonempty = m->blocks_nonempty;
1034
1035	i = m->heap_idx;
1036	heap_sift_up(h,	  i, ec_stripes_heap_cmp,
1037		     ec_stripes_heap_set_backpointer);
1038	heap_sift_down(h, i, ec_stripes_heap_cmp,
1039		       ec_stripes_heap_set_backpointer);
1040
1041	heap_verify_backpointer(c, idx);
1042
1043	do_deletes = stripe_idx_to_delete(c) != 0;
1044	mutex_unlock(&c->ec_stripes_heap_lock);
1045
1046	if (do_deletes)
1047		bch2_do_stripe_deletes(c);
1048}
1049
1050/* stripe deletion */
1051
1052static int ec_stripe_delete(struct btree_trans *trans, u64 idx)
1053{
1054	struct bch_fs *c = trans->c;
1055	struct btree_iter iter;
1056	struct bkey_s_c k;
1057	struct bkey_s_c_stripe s;
1058	int ret;
1059
1060	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_stripes, POS(0, idx),
1061			       BTREE_ITER_INTENT);
1062	ret = bkey_err(k);
1063	if (ret)
1064		goto err;
1065
1066	if (k.k->type != KEY_TYPE_stripe) {
1067		bch2_fs_inconsistent(c, "attempting to delete nonexistent stripe %llu", idx);
1068		ret = -EINVAL;
1069		goto err;
1070	}
1071
1072	s = bkey_s_c_to_stripe(k);
1073	for (unsigned i = 0; i < s.v->nr_blocks; i++)
1074		if (stripe_blockcount_get(s.v, i)) {
1075			struct printbuf buf = PRINTBUF;
1076
1077			bch2_bkey_val_to_text(&buf, c, k);
1078			bch2_fs_inconsistent(c, "attempting to delete nonempty stripe %s", buf.buf);
1079			printbuf_exit(&buf);
1080			ret = -EINVAL;
1081			goto err;
1082		}
1083
1084	ret = bch2_btree_delete_at(trans, &iter, 0);
1085err:
1086	bch2_trans_iter_exit(trans, &iter);
1087	return ret;
1088}
1089
1090static void ec_stripe_delete_work(struct work_struct *work)
1091{
1092	struct bch_fs *c =
1093		container_of(work, struct bch_fs, ec_stripe_delete_work);
1094
1095	while (1) {
1096		mutex_lock(&c->ec_stripes_heap_lock);
1097		u64 idx = stripe_idx_to_delete(c);
1098		mutex_unlock(&c->ec_stripes_heap_lock);
1099
1100		if (!idx)
1101			break;
1102
1103		int ret = bch2_trans_do(c, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
1104					ec_stripe_delete(trans, idx));
1105		bch_err_fn(c, ret);
1106		if (ret)
1107			break;
1108	}
1109
1110	bch2_write_ref_put(c, BCH_WRITE_REF_stripe_delete);
1111}
1112
1113void bch2_do_stripe_deletes(struct bch_fs *c)
1114{
1115	if (bch2_write_ref_tryget(c, BCH_WRITE_REF_stripe_delete) &&
1116	    !queue_work(c->write_ref_wq, &c->ec_stripe_delete_work))
1117		bch2_write_ref_put(c, BCH_WRITE_REF_stripe_delete);
1118}
1119
1120/* stripe creation: */
1121
1122static int ec_stripe_key_update(struct btree_trans *trans,
1123				struct bkey_i_stripe *new,
1124				bool create)
1125{
1126	struct bch_fs *c = trans->c;
1127	struct btree_iter iter;
1128	struct bkey_s_c k;
1129	int ret;
1130
1131	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_stripes,
1132			       new->k.p, BTREE_ITER_INTENT);
1133	ret = bkey_err(k);
1134	if (ret)
1135		goto err;
1136
1137	if (k.k->type != (create ? KEY_TYPE_deleted : KEY_TYPE_stripe)) {
1138		bch2_fs_inconsistent(c, "error %s stripe: got existing key type %s",
1139				     create ? "creating" : "updating",
1140				     bch2_bkey_types[k.k->type]);
1141		ret = -EINVAL;
1142		goto err;
1143	}
1144
1145	if (k.k->type == KEY_TYPE_stripe) {
1146		const struct bch_stripe *old = bkey_s_c_to_stripe(k).v;
1147		unsigned i;
1148
1149		if (old->nr_blocks != new->v.nr_blocks) {
1150			bch_err(c, "error updating stripe: nr_blocks does not match");
1151			ret = -EINVAL;
1152			goto err;
1153		}
1154
1155		for (i = 0; i < new->v.nr_blocks; i++) {
1156			unsigned v = stripe_blockcount_get(old, i);
1157
1158			BUG_ON(v &&
1159			       (old->ptrs[i].dev != new->v.ptrs[i].dev ||
1160				old->ptrs[i].gen != new->v.ptrs[i].gen ||
1161				old->ptrs[i].offset != new->v.ptrs[i].offset));
1162
1163			stripe_blockcount_set(&new->v, i, v);
1164		}
1165	}
1166
1167	ret = bch2_trans_update(trans, &iter, &new->k_i, 0);
1168err:
1169	bch2_trans_iter_exit(trans, &iter);
1170	return ret;
1171}
1172
1173static int ec_stripe_update_extent(struct btree_trans *trans,
1174				   struct bpos bucket, u8 gen,
1175				   struct ec_stripe_buf *s,
1176				   struct bpos *bp_pos)
1177{
1178	struct bch_stripe *v = &bkey_i_to_stripe(&s->key)->v;
1179	struct bch_fs *c = trans->c;
1180	struct bch_backpointer bp;
1181	struct btree_iter iter;
1182	struct bkey_s_c k;
1183	const struct bch_extent_ptr *ptr_c;
1184	struct bch_extent_ptr *ptr, *ec_ptr = NULL;
1185	struct bch_extent_stripe_ptr stripe_ptr;
1186	struct bkey_i *n;
1187	int ret, dev, block;
1188
1189	ret = bch2_get_next_backpointer(trans, bucket, gen,
1190				bp_pos, &bp, BTREE_ITER_CACHED);
1191	if (ret)
1192		return ret;
1193	if (bpos_eq(*bp_pos, SPOS_MAX))
1194		return 0;
1195
1196	if (bp.level) {
1197		struct printbuf buf = PRINTBUF;
1198		struct btree_iter node_iter;
1199		struct btree *b;
1200
1201		b = bch2_backpointer_get_node(trans, &node_iter, *bp_pos, bp);
1202		bch2_trans_iter_exit(trans, &node_iter);
1203
1204		if (!b)
1205			return 0;
1206
1207		prt_printf(&buf, "found btree node in erasure coded bucket: b=%px\n", b);
1208		bch2_backpointer_to_text(&buf, &bp);
1209
1210		bch2_fs_inconsistent(c, "%s", buf.buf);
1211		printbuf_exit(&buf);
1212		return -EIO;
1213	}
1214
1215	k = bch2_backpointer_get_key(trans, &iter, *bp_pos, bp, BTREE_ITER_INTENT);
1216	ret = bkey_err(k);
1217	if (ret)
1218		return ret;
1219	if (!k.k) {
1220		/*
1221		 * extent no longer exists - we could flush the btree
1222		 * write buffer and retry to verify, but no need:
1223		 */
1224		return 0;
1225	}
1226
1227	if (extent_has_stripe_ptr(k, s->key.k.p.offset))
1228		goto out;
1229
1230	ptr_c = bkey_matches_stripe(v, k, &block);
1231	/*
1232	 * It doesn't generally make sense to erasure code cached ptrs:
1233	 * XXX: should we be incrementing a counter?
1234	 */
1235	if (!ptr_c || ptr_c->cached)
1236		goto out;
1237
1238	dev = v->ptrs[block].dev;
1239
1240	n = bch2_trans_kmalloc(trans, bkey_bytes(k.k) + sizeof(stripe_ptr));
1241	ret = PTR_ERR_OR_ZERO(n);
1242	if (ret)
1243		goto out;
1244
1245	bkey_reassemble(n, k);
1246
1247	bch2_bkey_drop_ptrs(bkey_i_to_s(n), ptr, ptr->dev != dev);
1248	ec_ptr = bch2_bkey_has_device(bkey_i_to_s(n), dev);
1249	BUG_ON(!ec_ptr);
1250
1251	stripe_ptr = (struct bch_extent_stripe_ptr) {
1252		.type = 1 << BCH_EXTENT_ENTRY_stripe_ptr,
1253		.block		= block,
1254		.redundancy	= v->nr_redundant,
1255		.idx		= s->key.k.p.offset,
1256	};
1257
1258	__extent_entry_insert(n,
1259			(union bch_extent_entry *) ec_ptr,
1260			(union bch_extent_entry *) &stripe_ptr);
1261
1262	ret = bch2_trans_update(trans, &iter, n, 0);
1263out:
1264	bch2_trans_iter_exit(trans, &iter);
1265	return ret;
1266}
1267
1268static int ec_stripe_update_bucket(struct btree_trans *trans, struct ec_stripe_buf *s,
1269				   unsigned block)
1270{
1271	struct bch_fs *c = trans->c;
1272	struct bch_stripe *v = &bkey_i_to_stripe(&s->key)->v;
1273	struct bch_extent_ptr bucket = v->ptrs[block];
1274	struct bpos bucket_pos = PTR_BUCKET_POS(c, &bucket);
1275	struct bpos bp_pos = POS_MIN;
1276	int ret = 0;
1277
1278	while (1) {
1279		ret = commit_do(trans, NULL, NULL,
1280				BCH_TRANS_COMMIT_no_check_rw|
1281				BCH_TRANS_COMMIT_no_enospc,
1282			ec_stripe_update_extent(trans, bucket_pos, bucket.gen,
1283						s, &bp_pos));
1284		if (ret)
1285			break;
1286		if (bkey_eq(bp_pos, POS_MAX))
1287			break;
1288
1289		bp_pos = bpos_nosnap_successor(bp_pos);
1290	}
1291
1292	return ret;
1293}
1294
1295static int ec_stripe_update_extents(struct bch_fs *c, struct ec_stripe_buf *s)
1296{
1297	struct btree_trans *trans = bch2_trans_get(c);
1298	struct bch_stripe *v = &bkey_i_to_stripe(&s->key)->v;
1299	unsigned i, nr_data = v->nr_blocks - v->nr_redundant;
1300	int ret = 0;
1301
1302	ret = bch2_btree_write_buffer_flush_sync(trans);
1303	if (ret)
1304		goto err;
1305
1306	for (i = 0; i < nr_data; i++) {
1307		ret = ec_stripe_update_bucket(trans, s, i);
1308		if (ret)
1309			break;
1310	}
1311err:
1312	bch2_trans_put(trans);
1313
1314	return ret;
1315}
1316
1317static void zero_out_rest_of_ec_bucket(struct bch_fs *c,
1318				       struct ec_stripe_new *s,
1319				       unsigned block,
1320				       struct open_bucket *ob)
1321{
1322	struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
1323	unsigned offset = ca->mi.bucket_size - ob->sectors_free;
1324	int ret;
1325
1326	if (!bch2_dev_get_ioref(ca, WRITE)) {
1327		s->err = -BCH_ERR_erofs_no_writes;
1328		return;
1329	}
1330
1331	memset(s->new_stripe.data[block] + (offset << 9),
1332	       0,
1333	       ob->sectors_free << 9);
1334
1335	ret = blkdev_issue_zeroout(ca->disk_sb.bdev,
1336			ob->bucket * ca->mi.bucket_size + offset,
1337			ob->sectors_free,
1338			GFP_KERNEL, 0);
1339
1340	percpu_ref_put(&ca->io_ref);
1341
1342	if (ret)
1343		s->err = ret;
1344}
1345
1346void bch2_ec_stripe_new_free(struct bch_fs *c, struct ec_stripe_new *s)
1347{
1348	if (s->idx)
1349		bch2_stripe_close(c, s);
1350	kfree(s);
1351}
1352
1353/*
1354 * data buckets of new stripe all written: create the stripe
1355 */
1356static void ec_stripe_create(struct ec_stripe_new *s)
1357{
1358	struct bch_fs *c = s->c;
1359	struct open_bucket *ob;
1360	struct bch_stripe *v = &bkey_i_to_stripe(&s->new_stripe.key)->v;
1361	unsigned i, nr_data = v->nr_blocks - v->nr_redundant;
1362	int ret;
1363
1364	BUG_ON(s->h->s == s);
1365
1366	closure_sync(&s->iodone);
1367
1368	if (!s->err) {
1369		for (i = 0; i < nr_data; i++)
1370			if (s->blocks[i]) {
1371				ob = c->open_buckets + s->blocks[i];
1372
1373				if (ob->sectors_free)
1374					zero_out_rest_of_ec_bucket(c, s, i, ob);
1375			}
1376	}
1377
1378	if (s->err) {
1379		if (!bch2_err_matches(s->err, EROFS))
1380			bch_err(c, "error creating stripe: error writing data buckets");
1381		goto err;
1382	}
1383
1384	if (s->have_existing_stripe) {
1385		ec_validate_checksums(c, &s->existing_stripe);
1386
1387		if (ec_do_recov(c, &s->existing_stripe)) {
1388			bch_err(c, "error creating stripe: error reading existing stripe");
1389			goto err;
1390		}
1391
1392		for (i = 0; i < nr_data; i++)
1393			if (stripe_blockcount_get(&bkey_i_to_stripe(&s->existing_stripe.key)->v, i))
1394				swap(s->new_stripe.data[i],
1395				     s->existing_stripe.data[i]);
1396
1397		ec_stripe_buf_exit(&s->existing_stripe);
1398	}
1399
1400	BUG_ON(!s->allocated);
1401	BUG_ON(!s->idx);
1402
1403	ec_generate_ec(&s->new_stripe);
1404
1405	ec_generate_checksums(&s->new_stripe);
1406
1407	/* write p/q: */
1408	for (i = nr_data; i < v->nr_blocks; i++)
1409		ec_block_io(c, &s->new_stripe, REQ_OP_WRITE, i, &s->iodone);
1410	closure_sync(&s->iodone);
1411
1412	if (ec_nr_failed(&s->new_stripe)) {
1413		bch_err(c, "error creating stripe: error writing redundancy buckets");
1414		goto err;
1415	}
1416
1417	ret = bch2_trans_do(c, &s->res, NULL,
1418			    BCH_TRANS_COMMIT_no_check_rw|
1419			    BCH_TRANS_COMMIT_no_enospc,
1420			    ec_stripe_key_update(trans,
1421					bkey_i_to_stripe(&s->new_stripe.key),
1422					!s->have_existing_stripe));
1423	bch_err_msg(c, ret, "creating stripe key");
1424	if (ret) {
1425		goto err;
1426	}
1427
1428	ret = ec_stripe_update_extents(c, &s->new_stripe);
1429	bch_err_msg(c, ret, "error updating extents");
1430	if (ret)
1431		goto err;
1432err:
1433	bch2_disk_reservation_put(c, &s->res);
1434
1435	for (i = 0; i < v->nr_blocks; i++)
1436		if (s->blocks[i]) {
1437			ob = c->open_buckets + s->blocks[i];
1438
1439			if (i < nr_data) {
1440				ob->ec = NULL;
1441				__bch2_open_bucket_put(c, ob);
1442			} else {
1443				bch2_open_bucket_put(c, ob);
1444			}
1445		}
1446
1447	mutex_lock(&c->ec_stripe_new_lock);
1448	list_del(&s->list);
1449	mutex_unlock(&c->ec_stripe_new_lock);
1450	wake_up(&c->ec_stripe_new_wait);
1451
1452	ec_stripe_buf_exit(&s->existing_stripe);
1453	ec_stripe_buf_exit(&s->new_stripe);
1454	closure_debug_destroy(&s->iodone);
1455
1456	ec_stripe_new_put(c, s, STRIPE_REF_stripe);
1457}
1458
1459static struct ec_stripe_new *get_pending_stripe(struct bch_fs *c)
1460{
1461	struct ec_stripe_new *s;
1462
1463	mutex_lock(&c->ec_stripe_new_lock);
1464	list_for_each_entry(s, &c->ec_stripe_new_list, list)
1465		if (!atomic_read(&s->ref[STRIPE_REF_io]))
1466			goto out;
1467	s = NULL;
1468out:
1469	mutex_unlock(&c->ec_stripe_new_lock);
1470
1471	return s;
1472}
1473
1474static void ec_stripe_create_work(struct work_struct *work)
1475{
1476	struct bch_fs *c = container_of(work,
1477		struct bch_fs, ec_stripe_create_work);
1478	struct ec_stripe_new *s;
1479
1480	while ((s = get_pending_stripe(c)))
1481		ec_stripe_create(s);
1482
1483	bch2_write_ref_put(c, BCH_WRITE_REF_stripe_create);
1484}
1485
1486void bch2_ec_do_stripe_creates(struct bch_fs *c)
1487{
1488	bch2_write_ref_get(c, BCH_WRITE_REF_stripe_create);
1489
1490	if (!queue_work(system_long_wq, &c->ec_stripe_create_work))
1491		bch2_write_ref_put(c, BCH_WRITE_REF_stripe_create);
1492}
1493
1494static void ec_stripe_set_pending(struct bch_fs *c, struct ec_stripe_head *h)
1495{
1496	struct ec_stripe_new *s = h->s;
1497
1498	BUG_ON(!s->allocated && !s->err);
1499
1500	h->s		= NULL;
1501	s->pending	= true;
1502
1503	mutex_lock(&c->ec_stripe_new_lock);
1504	list_add(&s->list, &c->ec_stripe_new_list);
1505	mutex_unlock(&c->ec_stripe_new_lock);
1506
1507	ec_stripe_new_put(c, s, STRIPE_REF_io);
1508}
1509
1510void bch2_ec_bucket_cancel(struct bch_fs *c, struct open_bucket *ob)
1511{
1512	struct ec_stripe_new *s = ob->ec;
1513
1514	s->err = -EIO;
1515}
1516
1517void *bch2_writepoint_ec_buf(struct bch_fs *c, struct write_point *wp)
1518{
1519	struct open_bucket *ob = ec_open_bucket(c, &wp->ptrs);
1520	struct bch_dev *ca;
1521	unsigned offset;
1522
1523	if (!ob)
1524		return NULL;
1525
1526	BUG_ON(!ob->ec->new_stripe.data[ob->ec_idx]);
1527
1528	ca	= bch_dev_bkey_exists(c, ob->dev);
1529	offset	= ca->mi.bucket_size - ob->sectors_free;
1530
1531	return ob->ec->new_stripe.data[ob->ec_idx] + (offset << 9);
1532}
1533
1534static int unsigned_cmp(const void *_l, const void *_r)
1535{
1536	unsigned l = *((const unsigned *) _l);
1537	unsigned r = *((const unsigned *) _r);
1538
1539	return cmp_int(l, r);
1540}
1541
1542/* pick most common bucket size: */
1543static unsigned pick_blocksize(struct bch_fs *c,
1544			       struct bch_devs_mask *devs)
1545{
1546	unsigned nr = 0, sizes[BCH_SB_MEMBERS_MAX];
1547	struct {
1548		unsigned nr, size;
1549	} cur = { 0, 0 }, best = { 0, 0 };
1550
1551	for_each_member_device_rcu(c, ca, devs)
1552		sizes[nr++] = ca->mi.bucket_size;
1553
1554	sort(sizes, nr, sizeof(unsigned), unsigned_cmp, NULL);
1555
1556	for (unsigned i = 0; i < nr; i++) {
1557		if (sizes[i] != cur.size) {
1558			if (cur.nr > best.nr)
1559				best = cur;
1560
1561			cur.nr = 0;
1562			cur.size = sizes[i];
1563		}
1564
1565		cur.nr++;
1566	}
1567
1568	if (cur.nr > best.nr)
1569		best = cur;
1570
1571	return best.size;
1572}
1573
1574static bool may_create_new_stripe(struct bch_fs *c)
1575{
1576	return false;
1577}
1578
1579static void ec_stripe_key_init(struct bch_fs *c,
1580			       struct bkey_i *k,
1581			       unsigned nr_data,
1582			       unsigned nr_parity,
1583			       unsigned stripe_size)
1584{
1585	struct bkey_i_stripe *s = bkey_stripe_init(k);
1586	unsigned u64s;
1587
1588	s->v.sectors			= cpu_to_le16(stripe_size);
1589	s->v.algorithm			= 0;
1590	s->v.nr_blocks			= nr_data + nr_parity;
1591	s->v.nr_redundant		= nr_parity;
1592	s->v.csum_granularity_bits	= ilog2(c->opts.encoded_extent_max >> 9);
1593	s->v.csum_type			= BCH_CSUM_crc32c;
1594	s->v.pad			= 0;
1595
1596	while ((u64s = stripe_val_u64s(&s->v)) > BKEY_VAL_U64s_MAX) {
1597		BUG_ON(1 << s->v.csum_granularity_bits >=
1598		       le16_to_cpu(s->v.sectors) ||
1599		       s->v.csum_granularity_bits == U8_MAX);
1600		s->v.csum_granularity_bits++;
1601	}
1602
1603	set_bkey_val_u64s(&s->k, u64s);
1604}
1605
1606static int ec_new_stripe_alloc(struct bch_fs *c, struct ec_stripe_head *h)
1607{
1608	struct ec_stripe_new *s;
1609
1610	lockdep_assert_held(&h->lock);
1611
1612	s = kzalloc(sizeof(*s), GFP_KERNEL);
1613	if (!s)
1614		return -BCH_ERR_ENOMEM_ec_new_stripe_alloc;
1615
1616	mutex_init(&s->lock);
1617	closure_init(&s->iodone, NULL);
1618	atomic_set(&s->ref[STRIPE_REF_stripe], 1);
1619	atomic_set(&s->ref[STRIPE_REF_io], 1);
1620	s->c		= c;
1621	s->h		= h;
1622	s->nr_data	= min_t(unsigned, h->nr_active_devs,
1623				BCH_BKEY_PTRS_MAX) - h->redundancy;
1624	s->nr_parity	= h->redundancy;
1625
1626	ec_stripe_key_init(c, &s->new_stripe.key,
1627			   s->nr_data, s->nr_parity, h->blocksize);
1628
1629	h->s = s;
1630	return 0;
1631}
1632
1633static struct ec_stripe_head *
1634ec_new_stripe_head_alloc(struct bch_fs *c, unsigned target,
1635			 unsigned algo, unsigned redundancy,
1636			 enum bch_watermark watermark)
1637{
1638	struct ec_stripe_head *h;
1639
1640	h = kzalloc(sizeof(*h), GFP_KERNEL);
1641	if (!h)
1642		return NULL;
1643
1644	mutex_init(&h->lock);
1645	BUG_ON(!mutex_trylock(&h->lock));
1646
1647	h->target	= target;
1648	h->algo		= algo;
1649	h->redundancy	= redundancy;
1650	h->watermark	= watermark;
1651
1652	rcu_read_lock();
1653	h->devs = target_rw_devs(c, BCH_DATA_user, target);
1654
1655	for_each_member_device_rcu(c, ca, &h->devs)
1656		if (!ca->mi.durability)
1657			__clear_bit(ca->dev_idx, h->devs.d);
1658
1659	h->blocksize = pick_blocksize(c, &h->devs);
1660
1661	for_each_member_device_rcu(c, ca, &h->devs)
1662		if (ca->mi.bucket_size == h->blocksize)
1663			h->nr_active_devs++;
1664
1665	rcu_read_unlock();
1666
1667	/*
1668	 * If we only have redundancy + 1 devices, we're better off with just
1669	 * replication:
1670	 */
1671	if (h->nr_active_devs < h->redundancy + 2)
1672		bch_err(c, "insufficient devices available to create stripe (have %u, need %u) - mismatched bucket sizes?",
1673			h->nr_active_devs, h->redundancy + 2);
1674
1675	list_add(&h->list, &c->ec_stripe_head_list);
1676	return h;
1677}
1678
1679void bch2_ec_stripe_head_put(struct bch_fs *c, struct ec_stripe_head *h)
1680{
1681	if (h->s &&
1682	    h->s->allocated &&
1683	    bitmap_weight(h->s->blocks_allocated,
1684			  h->s->nr_data) == h->s->nr_data)
1685		ec_stripe_set_pending(c, h);
1686
1687	mutex_unlock(&h->lock);
1688}
1689
1690static struct ec_stripe_head *
1691__bch2_ec_stripe_head_get(struct btree_trans *trans,
1692			  unsigned target,
1693			  unsigned algo,
1694			  unsigned redundancy,
1695			  enum bch_watermark watermark)
1696{
1697	struct bch_fs *c = trans->c;
1698	struct ec_stripe_head *h;
1699	int ret;
1700
1701	if (!redundancy)
1702		return NULL;
1703
1704	ret = bch2_trans_mutex_lock(trans, &c->ec_stripe_head_lock);
1705	if (ret)
1706		return ERR_PTR(ret);
1707
1708	if (test_bit(BCH_FS_going_ro, &c->flags)) {
1709		h = ERR_PTR(-BCH_ERR_erofs_no_writes);
1710		goto found;
1711	}
1712
1713	list_for_each_entry(h, &c->ec_stripe_head_list, list)
1714		if (h->target		== target &&
1715		    h->algo		== algo &&
1716		    h->redundancy	== redundancy &&
1717		    h->watermark	== watermark) {
1718			ret = bch2_trans_mutex_lock(trans, &h->lock);
1719			if (ret)
1720				h = ERR_PTR(ret);
1721			goto found;
1722		}
1723
1724	h = ec_new_stripe_head_alloc(c, target, algo, redundancy, watermark);
1725found:
1726	if (!IS_ERR_OR_NULL(h) &&
1727	    h->nr_active_devs < h->redundancy + 2) {
1728		mutex_unlock(&h->lock);
1729		h = NULL;
1730	}
1731	mutex_unlock(&c->ec_stripe_head_lock);
1732	return h;
1733}
1734
1735static int new_stripe_alloc_buckets(struct btree_trans *trans, struct ec_stripe_head *h,
1736				    enum bch_watermark watermark, struct closure *cl)
1737{
1738	struct bch_fs *c = trans->c;
1739	struct bch_devs_mask devs = h->devs;
1740	struct open_bucket *ob;
1741	struct open_buckets buckets;
1742	struct bch_stripe *v = &bkey_i_to_stripe(&h->s->new_stripe.key)->v;
1743	unsigned i, j, nr_have_parity = 0, nr_have_data = 0;
1744	bool have_cache = true;
1745	int ret = 0;
1746
1747	BUG_ON(v->nr_blocks	!= h->s->nr_data + h->s->nr_parity);
1748	BUG_ON(v->nr_redundant	!= h->s->nr_parity);
1749
1750	for_each_set_bit(i, h->s->blocks_gotten, v->nr_blocks) {
1751		__clear_bit(v->ptrs[i].dev, devs.d);
1752		if (i < h->s->nr_data)
1753			nr_have_data++;
1754		else
1755			nr_have_parity++;
1756	}
1757
1758	BUG_ON(nr_have_data	> h->s->nr_data);
1759	BUG_ON(nr_have_parity	> h->s->nr_parity);
1760
1761	buckets.nr = 0;
1762	if (nr_have_parity < h->s->nr_parity) {
1763		ret = bch2_bucket_alloc_set_trans(trans, &buckets,
1764					    &h->parity_stripe,
1765					    &devs,
1766					    h->s->nr_parity,
1767					    &nr_have_parity,
1768					    &have_cache, 0,
1769					    BCH_DATA_parity,
1770					    watermark,
1771					    cl);
1772
1773		open_bucket_for_each(c, &buckets, ob, i) {
1774			j = find_next_zero_bit(h->s->blocks_gotten,
1775					       h->s->nr_data + h->s->nr_parity,
1776					       h->s->nr_data);
1777			BUG_ON(j >= h->s->nr_data + h->s->nr_parity);
1778
1779			h->s->blocks[j] = buckets.v[i];
1780			v->ptrs[j] = bch2_ob_ptr(c, ob);
1781			__set_bit(j, h->s->blocks_gotten);
1782		}
1783
1784		if (ret)
1785			return ret;
1786	}
1787
1788	buckets.nr = 0;
1789	if (nr_have_data < h->s->nr_data) {
1790		ret = bch2_bucket_alloc_set_trans(trans, &buckets,
1791					    &h->block_stripe,
1792					    &devs,
1793					    h->s->nr_data,
1794					    &nr_have_data,
1795					    &have_cache, 0,
1796					    BCH_DATA_user,
1797					    watermark,
1798					    cl);
1799
1800		open_bucket_for_each(c, &buckets, ob, i) {
1801			j = find_next_zero_bit(h->s->blocks_gotten,
1802					       h->s->nr_data, 0);
1803			BUG_ON(j >= h->s->nr_data);
1804
1805			h->s->blocks[j] = buckets.v[i];
1806			v->ptrs[j] = bch2_ob_ptr(c, ob);
1807			__set_bit(j, h->s->blocks_gotten);
1808		}
1809
1810		if (ret)
1811			return ret;
1812	}
1813
1814	return 0;
1815}
1816
1817/* XXX: doesn't obey target: */
1818static s64 get_existing_stripe(struct bch_fs *c,
1819			       struct ec_stripe_head *head)
1820{
1821	ec_stripes_heap *h = &c->ec_stripes_heap;
1822	struct stripe *m;
1823	size_t heap_idx;
1824	u64 stripe_idx;
1825	s64 ret = -1;
1826
1827	if (may_create_new_stripe(c))
1828		return -1;
1829
1830	mutex_lock(&c->ec_stripes_heap_lock);
1831	for (heap_idx = 0; heap_idx < h->used; heap_idx++) {
1832		/* No blocks worth reusing, stripe will just be deleted: */
1833		if (!h->data[heap_idx].blocks_nonempty)
1834			continue;
1835
1836		stripe_idx = h->data[heap_idx].idx;
1837
1838		m = genradix_ptr(&c->stripes, stripe_idx);
1839
1840		if (m->algorithm	== head->algo &&
1841		    m->nr_redundant	== head->redundancy &&
1842		    m->sectors		== head->blocksize &&
1843		    m->blocks_nonempty	< m->nr_blocks - m->nr_redundant &&
1844		    bch2_try_open_stripe(c, head->s, stripe_idx)) {
1845			ret = stripe_idx;
1846			break;
1847		}
1848	}
1849	mutex_unlock(&c->ec_stripes_heap_lock);
1850	return ret;
1851}
1852
1853static int __bch2_ec_stripe_head_reuse(struct btree_trans *trans, struct ec_stripe_head *h)
1854{
1855	struct bch_fs *c = trans->c;
1856	struct bch_stripe *new_v = &bkey_i_to_stripe(&h->s->new_stripe.key)->v;
1857	struct bch_stripe *existing_v;
1858	unsigned i;
1859	s64 idx;
1860	int ret;
1861
1862	/*
1863	 * If we can't allocate a new stripe, and there's no stripes with empty
1864	 * blocks for us to reuse, that means we have to wait on copygc:
1865	 */
1866	idx = get_existing_stripe(c, h);
1867	if (idx < 0)
1868		return -BCH_ERR_stripe_alloc_blocked;
1869
1870	ret = get_stripe_key_trans(trans, idx, &h->s->existing_stripe);
1871	if (ret) {
1872		bch2_stripe_close(c, h->s);
1873		if (!bch2_err_matches(ret, BCH_ERR_transaction_restart))
1874			bch2_fs_fatal_error(c, "error reading stripe key: %s", bch2_err_str(ret));
1875		return ret;
1876	}
1877
1878	existing_v = &bkey_i_to_stripe(&h->s->existing_stripe.key)->v;
1879
1880	BUG_ON(existing_v->nr_redundant != h->s->nr_parity);
1881	h->s->nr_data = existing_v->nr_blocks -
1882		existing_v->nr_redundant;
1883
1884	ret = ec_stripe_buf_init(&h->s->existing_stripe, 0, h->blocksize);
1885	if (ret) {
1886		bch2_stripe_close(c, h->s);
1887		return ret;
1888	}
1889
1890	BUG_ON(h->s->existing_stripe.size != h->blocksize);
1891	BUG_ON(h->s->existing_stripe.size != le16_to_cpu(existing_v->sectors));
1892
1893	/*
1894	 * Free buckets we initially allocated - they might conflict with
1895	 * blocks from the stripe we're reusing:
1896	 */
1897	for_each_set_bit(i, h->s->blocks_gotten, new_v->nr_blocks) {
1898		bch2_open_bucket_put(c, c->open_buckets + h->s->blocks[i]);
1899		h->s->blocks[i] = 0;
1900	}
1901	memset(h->s->blocks_gotten, 0, sizeof(h->s->blocks_gotten));
1902	memset(h->s->blocks_allocated, 0, sizeof(h->s->blocks_allocated));
1903
1904	for (i = 0; i < existing_v->nr_blocks; i++) {
1905		if (stripe_blockcount_get(existing_v, i)) {
1906			__set_bit(i, h->s->blocks_gotten);
1907			__set_bit(i, h->s->blocks_allocated);
1908		}
1909
1910		ec_block_io(c, &h->s->existing_stripe, READ, i, &h->s->iodone);
1911	}
1912
1913	bkey_copy(&h->s->new_stripe.key, &h->s->existing_stripe.key);
1914	h->s->have_existing_stripe = true;
1915
1916	return 0;
1917}
1918
1919static int __bch2_ec_stripe_head_reserve(struct btree_trans *trans, struct ec_stripe_head *h)
1920{
1921	struct bch_fs *c = trans->c;
1922	struct btree_iter iter;
1923	struct bkey_s_c k;
1924	struct bpos min_pos = POS(0, 1);
1925	struct bpos start_pos = bpos_max(min_pos, POS(0, c->ec_stripe_hint));
1926	int ret;
1927
1928	if (!h->s->res.sectors) {
1929		ret = bch2_disk_reservation_get(c, &h->s->res,
1930					h->blocksize,
1931					h->s->nr_parity,
1932					BCH_DISK_RESERVATION_NOFAIL);
1933		if (ret)
1934			return ret;
1935	}
1936
1937	for_each_btree_key_norestart(trans, iter, BTREE_ID_stripes, start_pos,
1938			   BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
1939		if (bkey_gt(k.k->p, POS(0, U32_MAX))) {
1940			if (start_pos.offset) {
1941				start_pos = min_pos;
1942				bch2_btree_iter_set_pos(&iter, start_pos);
1943				continue;
1944			}
1945
1946			ret = -BCH_ERR_ENOSPC_stripe_create;
1947			break;
1948		}
1949
1950		if (bkey_deleted(k.k) &&
1951		    bch2_try_open_stripe(c, h->s, k.k->p.offset))
1952			break;
1953	}
1954
1955	c->ec_stripe_hint = iter.pos.offset;
1956
1957	if (ret)
1958		goto err;
1959
1960	ret = ec_stripe_mem_alloc(trans, &iter);
1961	if (ret) {
1962		bch2_stripe_close(c, h->s);
1963		goto err;
1964	}
1965
1966	h->s->new_stripe.key.k.p = iter.pos;
1967out:
1968	bch2_trans_iter_exit(trans, &iter);
1969	return ret;
1970err:
1971	bch2_disk_reservation_put(c, &h->s->res);
1972	goto out;
1973}
1974
1975struct ec_stripe_head *bch2_ec_stripe_head_get(struct btree_trans *trans,
1976					       unsigned target,
1977					       unsigned algo,
1978					       unsigned redundancy,
1979					       enum bch_watermark watermark,
1980					       struct closure *cl)
1981{
1982	struct bch_fs *c = trans->c;
1983	struct ec_stripe_head *h;
1984	bool waiting = false;
1985	int ret;
1986
1987	h = __bch2_ec_stripe_head_get(trans, target, algo, redundancy, watermark);
1988	if (IS_ERR_OR_NULL(h))
1989		return h;
1990
1991	if (!h->s) {
1992		ret = ec_new_stripe_alloc(c, h);
1993		if (ret) {
1994			bch_err(c, "failed to allocate new stripe");
1995			goto err;
1996		}
1997	}
1998
1999	if (h->s->allocated)
2000		goto allocated;
2001
2002	if (h->s->have_existing_stripe)
2003		goto alloc_existing;
2004
2005	/* First, try to allocate a full stripe: */
2006	ret =   new_stripe_alloc_buckets(trans, h, BCH_WATERMARK_stripe, NULL) ?:
2007		__bch2_ec_stripe_head_reserve(trans, h);
2008	if (!ret)
2009		goto allocate_buf;
2010	if (bch2_err_matches(ret, BCH_ERR_transaction_restart) ||
2011	    bch2_err_matches(ret, ENOMEM))
2012		goto err;
2013
2014	/*
2015	 * Not enough buckets available for a full stripe: we must reuse an
2016	 * existing stripe:
2017	 */
2018	while (1) {
2019		ret = __bch2_ec_stripe_head_reuse(trans, h);
2020		if (!ret)
2021			break;
2022		if (waiting || !cl || ret != -BCH_ERR_stripe_alloc_blocked)
2023			goto err;
2024
2025		if (watermark == BCH_WATERMARK_copygc) {
2026			ret =   new_stripe_alloc_buckets(trans, h, watermark, NULL) ?:
2027				__bch2_ec_stripe_head_reserve(trans, h);
2028			if (ret)
2029				goto err;
2030			goto allocate_buf;
2031		}
2032
2033		/* XXX freelist_wait? */
2034		closure_wait(&c->freelist_wait, cl);
2035		waiting = true;
2036	}
2037
2038	if (waiting)
2039		closure_wake_up(&c->freelist_wait);
2040alloc_existing:
2041	/*
2042	 * Retry allocating buckets, with the watermark for this
2043	 * particular write:
2044	 */
2045	ret = new_stripe_alloc_buckets(trans, h, watermark, cl);
2046	if (ret)
2047		goto err;
2048
2049allocate_buf:
2050	ret = ec_stripe_buf_init(&h->s->new_stripe, 0, h->blocksize);
2051	if (ret)
2052		goto err;
2053
2054	h->s->allocated = true;
2055allocated:
2056	BUG_ON(!h->s->idx);
2057	BUG_ON(!h->s->new_stripe.data[0]);
2058	BUG_ON(trans->restarted);
2059	return h;
2060err:
2061	bch2_ec_stripe_head_put(c, h);
2062	return ERR_PTR(ret);
2063}
2064
2065static void __bch2_ec_stop(struct bch_fs *c, struct bch_dev *ca)
2066{
2067	struct ec_stripe_head *h;
2068	struct open_bucket *ob;
2069	unsigned i;
2070
2071	mutex_lock(&c->ec_stripe_head_lock);
2072	list_for_each_entry(h, &c->ec_stripe_head_list, list) {
2073		mutex_lock(&h->lock);
2074		if (!h->s)
2075			goto unlock;
2076
2077		if (!ca)
2078			goto found;
2079
2080		for (i = 0; i < bkey_i_to_stripe(&h->s->new_stripe.key)->v.nr_blocks; i++) {
2081			if (!h->s->blocks[i])
2082				continue;
2083
2084			ob = c->open_buckets + h->s->blocks[i];
2085			if (ob->dev == ca->dev_idx)
2086				goto found;
2087		}
2088		goto unlock;
2089found:
2090		h->s->err = -BCH_ERR_erofs_no_writes;
2091		ec_stripe_set_pending(c, h);
2092unlock:
2093		mutex_unlock(&h->lock);
2094	}
2095	mutex_unlock(&c->ec_stripe_head_lock);
2096}
2097
2098void bch2_ec_stop_dev(struct bch_fs *c, struct bch_dev *ca)
2099{
2100	__bch2_ec_stop(c, ca);
2101}
2102
2103void bch2_fs_ec_stop(struct bch_fs *c)
2104{
2105	__bch2_ec_stop(c, NULL);
2106}
2107
2108static bool bch2_fs_ec_flush_done(struct bch_fs *c)
2109{
2110	bool ret;
2111
2112	mutex_lock(&c->ec_stripe_new_lock);
2113	ret = list_empty(&c->ec_stripe_new_list);
2114	mutex_unlock(&c->ec_stripe_new_lock);
2115
2116	return ret;
2117}
2118
2119void bch2_fs_ec_flush(struct bch_fs *c)
2120{
2121	wait_event(c->ec_stripe_new_wait, bch2_fs_ec_flush_done(c));
2122}
2123
2124int bch2_stripes_read(struct bch_fs *c)
2125{
2126	int ret = bch2_trans_run(c,
2127		for_each_btree_key(trans, iter, BTREE_ID_stripes, POS_MIN,
2128				   BTREE_ITER_PREFETCH, k, ({
2129			if (k.k->type != KEY_TYPE_stripe)
2130				continue;
2131
2132			ret = __ec_stripe_mem_alloc(c, k.k->p.offset, GFP_KERNEL);
2133			if (ret)
2134				break;
2135
2136			const struct bch_stripe *s = bkey_s_c_to_stripe(k).v;
2137
2138			struct stripe *m = genradix_ptr(&c->stripes, k.k->p.offset);
2139			m->sectors	= le16_to_cpu(s->sectors);
2140			m->algorithm	= s->algorithm;
2141			m->nr_blocks	= s->nr_blocks;
2142			m->nr_redundant	= s->nr_redundant;
2143			m->blocks_nonempty = 0;
2144
2145			for (unsigned i = 0; i < s->nr_blocks; i++)
2146				m->blocks_nonempty += !!stripe_blockcount_get(s, i);
2147
2148			bch2_stripes_heap_insert(c, m, k.k->p.offset);
2149			0;
2150		})));
2151	bch_err_fn(c, ret);
2152	return ret;
2153}
2154
2155void bch2_stripes_heap_to_text(struct printbuf *out, struct bch_fs *c)
2156{
2157	ec_stripes_heap *h = &c->ec_stripes_heap;
2158	struct stripe *m;
2159	size_t i;
2160
2161	mutex_lock(&c->ec_stripes_heap_lock);
2162	for (i = 0; i < min_t(size_t, h->used, 50); i++) {
2163		m = genradix_ptr(&c->stripes, h->data[i].idx);
2164
2165		prt_printf(out, "%zu %u/%u+%u", h->data[i].idx,
2166		       h->data[i].blocks_nonempty,
2167		       m->nr_blocks - m->nr_redundant,
2168		       m->nr_redundant);
2169		if (bch2_stripe_is_open(c, h->data[i].idx))
2170			prt_str(out, " open");
2171		prt_newline(out);
2172	}
2173	mutex_unlock(&c->ec_stripes_heap_lock);
2174}
2175
2176void bch2_new_stripes_to_text(struct printbuf *out, struct bch_fs *c)
2177{
2178	struct ec_stripe_head *h;
2179	struct ec_stripe_new *s;
2180
2181	mutex_lock(&c->ec_stripe_head_lock);
2182	list_for_each_entry(h, &c->ec_stripe_head_list, list) {
2183		prt_printf(out, "target %u algo %u redundancy %u %s:\n",
2184		       h->target, h->algo, h->redundancy,
2185		       bch2_watermarks[h->watermark]);
2186
2187		if (h->s)
2188			prt_printf(out, "\tidx %llu blocks %u+%u allocated %u\n",
2189			       h->s->idx, h->s->nr_data, h->s->nr_parity,
2190			       bitmap_weight(h->s->blocks_allocated,
2191					     h->s->nr_data));
2192	}
2193	mutex_unlock(&c->ec_stripe_head_lock);
2194
2195	prt_printf(out, "in flight:\n");
2196
2197	mutex_lock(&c->ec_stripe_new_lock);
2198	list_for_each_entry(s, &c->ec_stripe_new_list, list) {
2199		prt_printf(out, "\tidx %llu blocks %u+%u ref %u %u %s\n",
2200			   s->idx, s->nr_data, s->nr_parity,
2201			   atomic_read(&s->ref[STRIPE_REF_io]),
2202			   atomic_read(&s->ref[STRIPE_REF_stripe]),
2203			   bch2_watermarks[s->h->watermark]);
2204	}
2205	mutex_unlock(&c->ec_stripe_new_lock);
2206}
2207
2208void bch2_fs_ec_exit(struct bch_fs *c)
2209{
2210	struct ec_stripe_head *h;
2211	unsigned i;
2212
2213	while (1) {
2214		mutex_lock(&c->ec_stripe_head_lock);
2215		h = list_first_entry_or_null(&c->ec_stripe_head_list,
2216					     struct ec_stripe_head, list);
2217		if (h)
2218			list_del(&h->list);
2219		mutex_unlock(&c->ec_stripe_head_lock);
2220		if (!h)
2221			break;
2222
2223		if (h->s) {
2224			for (i = 0; i < bkey_i_to_stripe(&h->s->new_stripe.key)->v.nr_blocks; i++)
2225				BUG_ON(h->s->blocks[i]);
2226
2227			kfree(h->s);
2228		}
2229		kfree(h);
2230	}
2231
2232	BUG_ON(!list_empty(&c->ec_stripe_new_list));
2233
2234	free_heap(&c->ec_stripes_heap);
2235	genradix_free(&c->stripes);
2236	bioset_exit(&c->ec_bioset);
2237}
2238
2239void bch2_fs_ec_init_early(struct bch_fs *c)
2240{
2241	spin_lock_init(&c->ec_stripes_new_lock);
2242	mutex_init(&c->ec_stripes_heap_lock);
2243
2244	INIT_LIST_HEAD(&c->ec_stripe_head_list);
2245	mutex_init(&c->ec_stripe_head_lock);
2246
2247	INIT_LIST_HEAD(&c->ec_stripe_new_list);
2248	mutex_init(&c->ec_stripe_new_lock);
2249	init_waitqueue_head(&c->ec_stripe_new_wait);
2250
2251	INIT_WORK(&c->ec_stripe_create_work, ec_stripe_create_work);
2252	INIT_WORK(&c->ec_stripe_delete_work, ec_stripe_delete_work);
2253}
2254
2255int bch2_fs_ec_init(struct bch_fs *c)
2256{
2257	return bioset_init(&c->ec_bioset, 1, offsetof(struct ec_bio, bio),
2258			   BIOSET_NEED_BVECS);
2259}