X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libbcachefs%2Fec.c;h=6027a7d4298165dfdff85e9c83db006888ddd85b;hb=63805882d4a60de63ed82d81ef4cfbb6e499753a;hp=9442d6e4041ca36169bc31eb37f68c81f029c6b2;hpb=37c9ba26af8aacba394ff8e6450ed6d49db6d623;p=bcachefs-tools-debian

diff --git a/libbcachefs/ec.c b/libbcachefs/ec.c
index 9442d6e..6027a7d 100644
--- a/libbcachefs/ec.c
+++ b/libbcachefs/ec.c
@@ -4,7 +4,7 @@
 
 #include "bcachefs.h"
 #include "alloc_foreground.h"
-#include "bkey_on_stack.h"
+#include "bkey_buf.h"
 #include "bset.h"
 #include "btree_gc.h"
 #include "btree_update.h"
@@ -15,6 +15,7 @@
 #include "io.h"
 #include "keylist.h"
 #include "recovery.h"
+#include "replicas.h"
 #include "super-io.h"
 #include "util.h"
 
@@ -105,6 +106,9 @@ const char *bch2_stripe_invalid(const struct bch_fs *c, struct bkey_s_c k)
 {
 	const struct bch_stripe *s = bkey_s_c_to_stripe(k).v;
 
+	if (!bkey_cmp(k.k->p, POS_MIN))
+		return "stripe at pos 0";
+
 	if (k.k->p.inode)
 		return "invalid stripe key";
 
@@ -138,46 +142,23 @@ void bch2_stripe_to_text(struct printbuf *out, struct bch_fs *c,
 		       stripe_blockcount_get(s, i));
 }
 
-static int ptr_matches_stripe(struct bch_fs *c,
-			      struct bch_stripe *v,
-			      const struct bch_extent_ptr *ptr)
+/* returns blocknr in stripe that we matched: */
+static const struct bch_extent_ptr *bkey_matches_stripe(struct bch_stripe *s,
+						struct bkey_s_c k, unsigned *block)
 {
-	unsigned i;
-
-	for (i = 0; i < v->nr_blocks - v->nr_redundant; i++) {
-		const struct bch_extent_ptr *ptr2 = v->ptrs + i;
-
-		if (ptr->dev == ptr2->dev &&
-		    ptr->gen == ptr2->gen &&
-		    ptr->offset >= ptr2->offset &&
-		    ptr->offset <  ptr2->offset + le16_to_cpu(v->sectors))
-			return i;
-	}
-
-	return -1;
-}
-
-static int extent_matches_stripe(struct bch_fs *c,
-				 struct bch_stripe *v,
-				 struct bkey_s_c k)
-{
-
-	switch (k.k->type) {
-	case KEY_TYPE_extent: {
-		struct bkey_s_c_extent e = bkey_s_c_to_extent(k);
-		const struct bch_extent_ptr *ptr;
-		int idx;
-
-		extent_for_each_ptr(e, ptr) {
-			idx = ptr_matches_stripe(c, v, ptr);
-			if (idx >= 0)
-				return idx;
-		}
-		break;
-	}
-	}
+	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
+	const struct bch_extent_ptr *ptr;
+	unsigned i, nr_data = s->nr_blocks - s->nr_redundant;
+
+	bkey_for_each_ptr(ptrs, ptr)
+		for (i = 0; i < nr_data; i++)
+			if (__bch2_ptr_matches_stripe(&s->ptrs[i], ptr,
+						      le16_to_cpu(s->sectors))) {
+				*block = i;
+				return ptr;
+			}
 
-	return -1;
+	return NULL;
 }
 
 static bool extent_has_stripe_ptr(struct bkey_s_c k, u64 idx)
@@ -200,80 +181,95 @@ static bool extent_has_stripe_ptr(struct bkey_s_c k, u64 idx)
 	return false;
 }
 
-static void ec_stripe_key_init(struct bch_fs *c,
-			       struct bkey_i_stripe *s,
-			       struct open_buckets *blocks,
-			       struct open_buckets *parity,
-			       unsigned stripe_size)
+/* Stripe bufs: */
+
+static void ec_stripe_buf_exit(struct ec_stripe_buf *buf)
 {
-	struct open_bucket *ob;
-	unsigned i, u64s;
+	unsigned i;
 
-	bkey_stripe_init(&s->k_i);
-	s->v.sectors			= cpu_to_le16(stripe_size);
-	s->v.algorithm			= 0;
-	s->v.nr_blocks			= parity->nr + blocks->nr;
-	s->v.nr_redundant		= parity->nr;
-	s->v.csum_granularity_bits	= ilog2(c->sb.encoded_extent_max);
-	s->v.csum_type			= BCH_CSUM_CRC32C;
-	s->v.pad			= 0;
+	for (i = 0; i < buf->key.v.nr_blocks; i++) {
+		kvpfree(buf->data[i], buf->size << 9);
+		buf->data[i] = NULL;
+	}
+}
 
-	open_bucket_for_each(c, blocks, ob, i)
-		s->v.ptrs[i]			= ob->ptr;
+static int ec_stripe_buf_init(struct ec_stripe_buf *buf,
+			       unsigned offset, unsigned size)
+{
+	struct bch_stripe *v = &buf->key.v;
+	unsigned csum_granularity = 1U << v->csum_granularity_bits;
+	unsigned end = offset + size;
+	unsigned i;
 
-	open_bucket_for_each(c, parity, ob, i)
-		s->v.ptrs[blocks->nr + i]	= ob->ptr;
+	BUG_ON(end > le16_to_cpu(v->sectors));
 
-	while ((u64s = stripe_val_u64s(&s->v)) > BKEY_VAL_U64s_MAX) {
-		BUG_ON(1 << s->v.csum_granularity_bits >=
-		       le16_to_cpu(s->v.sectors) ||
-		       s->v.csum_granularity_bits == U8_MAX);
-		s->v.csum_granularity_bits++;
+	offset	= round_down(offset, csum_granularity);
+	end	= min_t(unsigned, le16_to_cpu(v->sectors),
+			round_up(end, csum_granularity));
+
+	buf->offset	= offset;
+	buf->size	= end - offset;
+
+	memset(buf->valid, 0xFF, sizeof(buf->valid));
+
+	for (i = 0; i < buf->key.v.nr_blocks; i++) {
+		buf->data[i] = kvpmalloc(buf->size << 9, GFP_KERNEL);
+		if (!buf->data[i])
+			goto err;
 	}
 
-	set_bkey_val_u64s(&s->k, u64s);
+	return 0;
+err:
+	ec_stripe_buf_exit(buf);
+	return -ENOMEM;
 }
 
 /* Checksumming: */
 
-static void ec_generate_checksums(struct ec_stripe_buf *buf)
+static struct bch_csum ec_block_checksum(struct ec_stripe_buf *buf,
+					 unsigned block, unsigned offset)
 {
 	struct bch_stripe *v = &buf->key.v;
 	unsigned csum_granularity = 1 << v->csum_granularity_bits;
-	unsigned csums_per_device = stripe_csums_per_device(v);
-	unsigned csum_bytes = bch_crc_bytes[v->csum_type];
-	unsigned i, j;
+	unsigned end = buf->offset + buf->size;
+	unsigned len = min(csum_granularity, end - offset);
+
+	BUG_ON(offset >= end);
+	BUG_ON(offset <  buf->offset);
+	BUG_ON(offset & (csum_granularity - 1));
+	BUG_ON(offset + len != le16_to_cpu(v->sectors) &&
+	       (len & (csum_granularity - 1)));
+
+	return bch2_checksum(NULL, v->csum_type,
+			     null_nonce(),
+			     buf->data[block] + ((offset - buf->offset) << 9),
+			     len << 9);
+}
 
-	if (!csum_bytes)
+static void ec_generate_checksums(struct ec_stripe_buf *buf)
+{
+	struct bch_stripe *v = &buf->key.v;
+	unsigned i, j, csums_per_device = stripe_csums_per_device(v);
+
+	if (!v->csum_type)
 		return;
 
 	BUG_ON(buf->offset);
 	BUG_ON(buf->size != le16_to_cpu(v->sectors));
 
-	for (i = 0; i < v->nr_blocks; i++) {
-		for (j = 0; j < csums_per_device; j++) {
-			unsigned offset = j << v->csum_granularity_bits;
-			unsigned len = min(csum_granularity, buf->size - offset);
-
-			struct bch_csum csum =
-				bch2_checksum(NULL, v->csum_type,
-					      null_nonce(),
-					      buf->data[i] + (offset << 9),
-					      len << 9);
-
-			memcpy(stripe_csum(v, i, j), &csum, csum_bytes);
-		}
-	}
+	for (i = 0; i < v->nr_blocks; i++)
+		for (j = 0; j < csums_per_device; j++)
+			stripe_csum_set(v, i, j,
+				ec_block_checksum(buf, i, j << v->csum_granularity_bits));
 }
 
 static void ec_validate_checksums(struct bch_fs *c, struct ec_stripe_buf *buf)
 {
 	struct bch_stripe *v = &buf->key.v;
 	unsigned csum_granularity = 1 << v->csum_granularity_bits;
-	unsigned csum_bytes = bch_crc_bytes[v->csum_type];
 	unsigned i;
 
-	if (!csum_bytes)
+	if (!v->csum_type)
 		return;
 
 	for (i = 0; i < v->nr_blocks; i++) {
@@ -286,21 +282,19 @@ static void ec_validate_checksums(struct bch_fs *c, struct ec_stripe_buf *buf)
 		while (offset < end) {
 			unsigned j = offset >> v->csum_granularity_bits;
 			unsigned len = min(csum_granularity, end - offset);
-			struct bch_csum csum;
+			struct bch_csum want = stripe_csum_get(v, i, j);
+			struct bch_csum got = ec_block_checksum(buf, i, offset);
 
-			BUG_ON(offset & (csum_granularity - 1));
-			BUG_ON(offset + len != le16_to_cpu(v->sectors) &&
-			       ((offset + len) & (csum_granularity - 1)));
+			if (bch2_crc_cmp(want, got)) {
+				struct printbuf buf2 = PRINTBUF;
 
-			csum = bch2_checksum(NULL, v->csum_type,
-					     null_nonce(),
-					     buf->data[i] + ((offset - buf->offset) << 9),
-					     len << 9);
+				bch2_bkey_val_to_text(&buf2, c, bkey_i_to_s_c(&buf->key.k_i));
 
-			if (memcmp(stripe_csum(v, i, j), &csum, csum_bytes)) {
-				__bcache_io_error(c,
-					"checksum error while doing reconstruct read (%u:%u)",
-					i, j);
+				bch_err_ratelimited(c,
+					"stripe checksum error for %ps at %u:%u: csum type %u, expected %llx got %llx\n%s",
+					(void *) _RET_IP_, i, j, v->csum_type,
+					want.lo, got.lo, buf2.buf);
+				printbuf_exit(&buf2);
 				clear_bit(i, buf->valid);
 				break;
 			}
@@ -321,25 +315,21 @@ static void ec_generate_ec(struct ec_stripe_buf *buf)
 	raid_gen(nr_data, v->nr_redundant, bytes, buf->data);
 }
 
-static unsigned __ec_nr_failed(struct ec_stripe_buf *buf, unsigned nr)
-{
-	return nr - bitmap_weight(buf->valid, nr);
-}
-
 static unsigned ec_nr_failed(struct ec_stripe_buf *buf)
 {
-	return __ec_nr_failed(buf, buf->key.v.nr_blocks);
+	return buf->key.v.nr_blocks -
+		bitmap_weight(buf->valid, buf->key.v.nr_blocks);
 }
 
 static int ec_do_recov(struct bch_fs *c, struct ec_stripe_buf *buf)
 {
 	struct bch_stripe *v = &buf->key.v;
-	unsigned i, failed[EC_STRIPE_MAX], nr_failed = 0;
+	unsigned i, failed[BCH_BKEY_PTRS_MAX], nr_failed = 0;
 	unsigned nr_data = v->nr_blocks - v->nr_redundant;
 	unsigned bytes = buf->size << 9;
 
 	if (ec_nr_failed(buf) > v->nr_redundant) {
-		__bcache_io_error(c,
+		bch_err_ratelimited(c,
 			"error doing reconstruct read: unable to read enough blocks");
 		return -1;
 	}
@@ -357,12 +347,23 @@ static int ec_do_recov(struct bch_fs *c, struct ec_stripe_buf *buf)
 static void ec_block_endio(struct bio *bio)
 {
 	struct ec_bio *ec_bio = container_of(bio, struct ec_bio, bio);
+	struct bch_stripe *v = &ec_bio->buf->key.v;
+	struct bch_extent_ptr *ptr = &v->ptrs[ec_bio->idx];
 	struct bch_dev *ca = ec_bio->ca;
 	struct closure *cl = bio->bi_private;
 
-	if (bch2_dev_io_err_on(bio->bi_status, ca, "erasure coding"))
+	if (bch2_dev_io_err_on(bio->bi_status, ca, "erasure coding %s error: %s",
+			       bio_data_dir(bio) ? "write" : "read",
+			       bch2_blk_status_to_str(bio->bi_status)))
 		clear_bit(ec_bio->idx, ec_bio->buf->valid);
 
+	if (ptr_stale(ca, ptr)) {
+		bch_err_ratelimited(ca->fs,
+				    "error %s stripe: stale pointer after io",
+				    bio_data_dir(bio) == READ ? "reading from" : "writing to");
+		clear_bit(ec_bio->idx, ec_bio->buf->valid);
+	}
+
 	bio_put(&ec_bio->bio);
 	percpu_ref_put(&ca->io_ref);
 	closure_put(cl);
@@ -375,14 +376,27 @@ static void ec_block_io(struct bch_fs *c, struct ec_stripe_buf *buf,
 	unsigned offset = 0, bytes = buf->size << 9;
 	struct bch_extent_ptr *ptr = &v->ptrs[idx];
 	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
+	enum bch_data_type data_type = idx < buf->key.v.nr_blocks - buf->key.v.nr_redundant
+		? BCH_DATA_user
+		: BCH_DATA_parity;
+
+	if (ptr_stale(ca, ptr)) {
+		bch_err_ratelimited(c,
+				    "error %s stripe: stale pointer",
+				    rw == READ ? "reading from" : "writing to");
+		clear_bit(idx, buf->valid);
+		return;
+	}
 
 	if (!bch2_dev_get_ioref(ca, rw)) {
 		clear_bit(idx, buf->valid);
 		return;
 	}
 
+	this_cpu_add(ca->io_done->sectors[rw][data_type], buf->size);
+
 	while (offset < bytes) {
-		unsigned nr_iovecs = min_t(size_t, BIO_MAX_PAGES,
+		unsigned nr_iovecs = min_t(size_t, BIO_MAX_VECS,
 					   DIV_ROUND_UP(bytes, PAGE_SIZE));
 		unsigned b = min_t(size_t, bytes - offset,
 				   nr_iovecs << PAGE_SHIFT);
@@ -416,92 +430,84 @@ static void ec_block_io(struct bch_fs *c, struct ec_stripe_buf *buf,
 	percpu_ref_put(&ca->io_ref);
 }
 
+static int get_stripe_key(struct bch_fs *c, u64 idx, struct ec_stripe_buf *stripe)
+{
+	struct btree_trans trans;
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	int ret;
+
+	bch2_trans_init(&trans, c, 0, 0);
+	bch2_trans_iter_init(&trans, &iter, BTREE_ID_stripes,
+			     POS(0, idx), BTREE_ITER_SLOTS);
+	k = bch2_btree_iter_peek_slot(&iter);
+	ret = bkey_err(k);
+	if (ret)
+		goto err;
+	if (k.k->type != KEY_TYPE_stripe) {
+		ret = -ENOENT;
+		goto err;
+	}
+	bkey_reassemble(&stripe->key.k_i, k);
+err:
+	bch2_trans_iter_exit(&trans, &iter);
+	bch2_trans_exit(&trans);
+	return ret;
+}
+
 /* recovery read path: */
 int bch2_ec_read_extent(struct bch_fs *c, struct bch_read_bio *rbio)
 {
-	struct btree_trans trans;
-	struct btree_iter *iter;
 	struct ec_stripe_buf *buf;
 	struct closure cl;
-	struct bkey_s_c k;
 	struct bch_stripe *v;
-	unsigned stripe_idx;
-	unsigned offset, end;
-	unsigned i, nr_data, csum_granularity;
-	int ret = 0, idx;
+	unsigned i, offset;
+	int ret = 0;
 
 	closure_init_stack(&cl);
 
 	BUG_ON(!rbio->pick.has_ec);
 
-	stripe_idx = rbio->pick.ec.idx;
-
 	buf = kzalloc(sizeof(*buf), GFP_NOIO);
 	if (!buf)
 		return -ENOMEM;
 
-	bch2_trans_init(&trans, c, 0, 0);
-
-	iter = bch2_trans_get_iter(&trans, BTREE_ID_EC,
-				   POS(0, stripe_idx),
-				   BTREE_ITER_SLOTS);
-	k = bch2_btree_iter_peek_slot(iter);
-	if (bkey_err(k) || k.k->type != KEY_TYPE_stripe) {
-		__bcache_io_error(c,
-			"error doing reconstruct read: stripe not found");
+	ret = get_stripe_key(c, rbio->pick.ec.idx, buf);
+	if (ret) {
+		bch_err_ratelimited(c,
+			"error doing reconstruct read: error %i looking up stripe", ret);
 		kfree(buf);
-		return bch2_trans_exit(&trans) ?: -EIO;
+		return -EIO;
 	}
 
-	bkey_reassemble(&buf->key.k_i, k);
-	bch2_trans_exit(&trans);
-
 	v = &buf->key.v;
 
-	nr_data = v->nr_blocks - v->nr_redundant;
-
-	idx = ptr_matches_stripe(c, v, &rbio->pick.ptr);
-	BUG_ON(idx < 0);
-
-	csum_granularity = 1U << v->csum_granularity_bits;
-
-	offset	= rbio->bio.bi_iter.bi_sector - v->ptrs[idx].offset;
-	end	= offset + bio_sectors(&rbio->bio);
-
-	BUG_ON(end > le16_to_cpu(v->sectors));
-
-	buf->offset	= round_down(offset, csum_granularity);
-	buf->size	= min_t(unsigned, le16_to_cpu(v->sectors),
-				round_up(end, csum_granularity)) - buf->offset;
-
-	for (i = 0; i < v->nr_blocks; i++) {
-		buf->data[i] = kmalloc(buf->size << 9, GFP_NOIO);
-		if (!buf->data[i]) {
-			ret = -ENOMEM;
-			goto err;
-		}
+	if (!bch2_ptr_matches_stripe(v, rbio->pick)) {
+		bch_err_ratelimited(c,
+			"error doing reconstruct read: pointer doesn't match stripe");
+		ret = -EIO;
+		goto err;
 	}
 
-	memset(buf->valid, 0xFF, sizeof(buf->valid));
-
-	for (i = 0; i < v->nr_blocks; i++) {
-		struct bch_extent_ptr *ptr = v->ptrs + i;
-		struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
+	offset = rbio->bio.bi_iter.bi_sector - v->ptrs[rbio->pick.ec.block].offset;
+	if (offset + bio_sectors(&rbio->bio) > le16_to_cpu(v->sectors)) {
+		bch_err_ratelimited(c,
+			"error doing reconstruct read: read is bigger than stripe");
+		ret = -EIO;
+		goto err;
+	}
 
-		if (ptr_stale(ca, ptr)) {
-			__bcache_io_error(c,
-					  "error doing reconstruct read: stale pointer");
-			clear_bit(i, buf->valid);
-			continue;
-		}
+	ret = ec_stripe_buf_init(buf, offset, bio_sectors(&rbio->bio));
+	if (ret)
+		goto err;
 
+	for (i = 0; i < v->nr_blocks; i++)
 		ec_block_io(c, buf, REQ_OP_READ, i, &cl);
-	}
 
 	closure_sync(&cl);
 
 	if (ec_nr_failed(buf) > v->nr_redundant) {
-		__bcache_io_error(c,
+		bch_err_ratelimited(c,
 			"error doing reconstruct read: unable to read enough blocks");
 		ret = -EIO;
 		goto err;
@@ -514,10 +520,9 @@ int bch2_ec_read_extent(struct bch_fs *c, struct bch_read_bio *rbio)
 		goto err;
 
 	memcpy_to_bio(&rbio->bio, rbio->bio.bi_iter,
-		      buf->data[idx] + ((offset - buf->offset) << 9));
+		      buf->data[rbio->pick.ec.block] + ((offset - buf->offset) << 9));
 err:
-	for (i = 0; i < v->nr_blocks; i++)
-		kfree(buf->data[i]);
+	ec_stripe_buf_exit(buf);
 	kfree(buf);
 	return ret;
 }
@@ -543,29 +548,29 @@ static int __ec_stripe_mem_alloc(struct bch_fs *c, size_t idx, gfp_t gfp)
 		free_heap(&n);
 	}
 
-	if (!genradix_ptr_alloc(&c->stripes[0], idx, gfp))
+	if (!genradix_ptr_alloc(&c->stripes, idx, gfp))
 		return -ENOMEM;
 
 	if (c->gc_pos.phase != GC_PHASE_NOT_RUNNING &&
-	    !genradix_ptr_alloc(&c->stripes[1], idx, gfp))
+	    !genradix_ptr_alloc(&c->gc_stripes, idx, gfp))
 		return -ENOMEM;
 
 	return 0;
 }
 
-static int ec_stripe_mem_alloc(struct bch_fs *c,
+static int ec_stripe_mem_alloc(struct btree_trans *trans,
 			       struct btree_iter *iter)
 {
 	size_t idx = iter->pos.offset;
 	int ret = 0;
 
-	if (!__ec_stripe_mem_alloc(c, idx, GFP_NOWAIT|__GFP_NOWARN))
+	if (!__ec_stripe_mem_alloc(trans->c, idx, GFP_NOWAIT|__GFP_NOWARN))
 		return ret;
 
-	bch2_trans_unlock(iter->trans);
+	bch2_trans_unlock(trans);
 	ret = -EINTR;
 
-	if (!__ec_stripe_mem_alloc(c, idx, GFP_KERNEL))
+	if (!__ec_stripe_mem_alloc(trans->c, idx, GFP_KERNEL))
 		return ret;
 
 	return -ENOMEM;
@@ -592,52 +597,29 @@ static inline void ec_stripes_heap_set_backpointer(ec_stripes_heap *h,
 {
 	struct bch_fs *c = container_of(h, struct bch_fs, ec_stripes_heap);
 
-	genradix_ptr(&c->stripes[0], h->data[i].idx)->heap_idx = i;
+	genradix_ptr(&c->stripes, h->data[i].idx)->heap_idx = i;
 }
 
 static void heap_verify_backpointer(struct bch_fs *c, size_t idx)
 {
 	ec_stripes_heap *h = &c->ec_stripes_heap;
-	struct stripe *m = genradix_ptr(&c->stripes[0], idx);
+	struct stripe *m = genradix_ptr(&c->stripes, idx);
 
 	BUG_ON(!m->alive);
 	BUG_ON(m->heap_idx >= h->used);
 	BUG_ON(h->data[m->heap_idx].idx != idx);
 }
 
-void bch2_stripes_heap_update(struct bch_fs *c,
-			      struct stripe *m, size_t idx)
-{
-	ec_stripes_heap *h = &c->ec_stripes_heap;
-	size_t i;
-
-	if (m->alive) {
-		heap_verify_backpointer(c, idx);
-
-		h->data[m->heap_idx].blocks_nonempty = m->blocks_nonempty;
-
-		i = m->heap_idx;
-		heap_sift_up(h,	  i, ec_stripes_heap_cmp,
-			     ec_stripes_heap_set_backpointer);
-		heap_sift_down(h, i, ec_stripes_heap_cmp,
-			       ec_stripes_heap_set_backpointer);
-
-		heap_verify_backpointer(c, idx);
-	} else {
-		bch2_stripes_heap_insert(c, m, idx);
-	}
-
-	if (stripe_idx_to_delete(c) >= 0 &&
-	    !percpu_ref_is_dying(&c->writes))
-		schedule_work(&c->ec_stripe_delete_work);
-}
-
 void bch2_stripes_heap_del(struct bch_fs *c,
 			   struct stripe *m, size_t idx)
 {
+	if (!m->on_heap)
+		return;
+
+	m->on_heap = false;
+
 	heap_verify_backpointer(c, idx);
 
-	m->alive = false;
 	heap_del(&c->ec_stripes_heap, m->heap_idx,
 		 ec_stripes_heap_cmp,
 		 ec_stripes_heap_set_backpointer);
@@ -646,27 +628,57 @@ void bch2_stripes_heap_del(struct bch_fs *c,
 void bch2_stripes_heap_insert(struct bch_fs *c,
 			      struct stripe *m, size_t idx)
 {
+	if (m->on_heap)
+		return;
+
 	BUG_ON(heap_full(&c->ec_stripes_heap));
 
+	m->on_heap = true;
+
 	heap_add(&c->ec_stripes_heap, ((struct ec_stripe_heap_entry) {
 			.idx = idx,
 			.blocks_nonempty = m->blocks_nonempty,
 		}),
 		 ec_stripes_heap_cmp,
 		 ec_stripes_heap_set_backpointer);
-	m->alive = true;
 
 	heap_verify_backpointer(c, idx);
 }
 
+void bch2_stripes_heap_update(struct bch_fs *c,
+			      struct stripe *m, size_t idx)
+{
+	ec_stripes_heap *h = &c->ec_stripes_heap;
+	size_t i;
+
+	if (!m->on_heap)
+		return;
+
+	heap_verify_backpointer(c, idx);
+
+	h->data[m->heap_idx].blocks_nonempty = m->blocks_nonempty;
+
+	i = m->heap_idx;
+	heap_sift_up(h,	  i, ec_stripes_heap_cmp,
+		     ec_stripes_heap_set_backpointer);
+	heap_sift_down(h, i, ec_stripes_heap_cmp,
+		       ec_stripes_heap_set_backpointer);
+
+	heap_verify_backpointer(c, idx);
+
+	if (stripe_idx_to_delete(c) >= 0 &&
+	    !percpu_ref_is_dying(&c->writes))
+		schedule_work(&c->ec_stripe_delete_work);
+}
+
 /* stripe deletion */
 
 static int ec_stripe_delete(struct bch_fs *c, size_t idx)
 {
-	return bch2_btree_delete_range(c, BTREE_ID_EC,
+	return bch2_btree_delete_range(c, BTREE_ID_stripes,
 				       POS(0, idx),
 				       POS(0, idx + 1),
-				       NULL);
+				       0, NULL);
 }
 
 static void ec_stripe_delete_work(struct work_struct *work)
@@ -675,46 +687,41 @@ static void ec_stripe_delete_work(struct work_struct *work)
 		container_of(work, struct bch_fs, ec_stripe_delete_work);
 	ssize_t idx;
 
-	down_read(&c->gc_lock);
-	mutex_lock(&c->ec_stripe_create_lock);
-
 	while (1) {
 		spin_lock(&c->ec_stripes_heap_lock);
 		idx = stripe_idx_to_delete(c);
-		spin_unlock(&c->ec_stripes_heap_lock);
-
-		if (idx < 0)
+		if (idx < 0) {
+			spin_unlock(&c->ec_stripes_heap_lock);
 			break;
+		}
+
+		bch2_stripes_heap_del(c, genradix_ptr(&c->stripes, idx), idx);
+		spin_unlock(&c->ec_stripes_heap_lock);
 
 		if (ec_stripe_delete(c, idx))
 			break;
 	}
-
-	mutex_unlock(&c->ec_stripe_create_lock);
-	up_read(&c->gc_lock);
 }
 
 /* stripe creation: */
 
-static int ec_stripe_bkey_insert(struct bch_fs *c,
-				 struct bkey_i_stripe *stripe)
+static int ec_stripe_bkey_insert(struct btree_trans *trans,
+				 struct bkey_i_stripe *stripe,
+				 struct disk_reservation *res)
 {
-	struct btree_trans trans;
-	struct btree_iter *iter;
+	struct bch_fs *c = trans->c;
+	struct btree_iter iter;
 	struct bkey_s_c k;
-	struct bpos start_pos = POS(0, c->ec_stripe_hint);
+	struct bpos min_pos = POS(0, 1);
+	struct bpos start_pos = bpos_max(min_pos, POS(0, c->ec_stripe_hint));
 	int ret;
 
-	bch2_trans_init(&trans, c, 0, 0);
-retry:
-	bch2_trans_begin(&trans);
-
-	for_each_btree_key(&trans, iter, BTREE_ID_EC, start_pos,
+	for_each_btree_key(trans, iter, BTREE_ID_stripes, start_pos,
 			   BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
 		if (bkey_cmp(k.k->p, POS(0, U32_MAX)) > 0) {
 			if (start_pos.offset) {
-				start_pos = POS_MIN;
-				bch2_btree_iter_set_pos(iter, start_pos);
+				start_pos = min_pos;
+				bch2_btree_iter_set_pos(&iter, start_pos);
 				continue;
 			}
 
@@ -728,27 +735,61 @@ retry:
 
 	goto err;
 found_slot:
-	start_pos = iter->pos;
+	start_pos = iter.pos;
 
-	ret = ec_stripe_mem_alloc(c, iter);
+	ret = ec_stripe_mem_alloc(trans, &iter);
 	if (ret)
 		goto err;
 
-	stripe->k.p = iter->pos;
+	stripe->k.p = iter.pos;
 
-	bch2_trans_update(&trans, iter, &stripe->k_i, 0);
+	ret = bch2_trans_update(trans, &iter, &stripe->k_i, 0);
 
-	ret = bch2_trans_commit(&trans, NULL, NULL,
-				BTREE_INSERT_NOFAIL);
+	c->ec_stripe_hint = start_pos.offset;
 err:
-	bch2_trans_iter_put(&trans, iter);
+	bch2_trans_iter_exit(trans, &iter);
 
-	if (ret == -EINTR)
-		goto retry;
+	return ret;
+}
 
-	c->ec_stripe_hint = ret ? start_pos.offset : start_pos.offset + 1;
-	bch2_trans_exit(&trans);
+static int ec_stripe_bkey_update(struct btree_trans *trans,
+				 struct bkey_i_stripe *new,
+				 struct disk_reservation *res)
+{
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	const struct bch_stripe *existing;
+	unsigned i;
+	int ret;
+
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_stripes,
+			     new->k.p, BTREE_ITER_INTENT);
+	k = bch2_btree_iter_peek_slot(&iter);
+	ret = bkey_err(k);
+	if (ret)
+		goto err;
+
+	if (!k.k || k.k->type != KEY_TYPE_stripe) {
+		bch_err(trans->c, "error updating stripe: not found");
+		ret = -ENOENT;
+		goto err;
+	}
+
+	existing = bkey_s_c_to_stripe(k).v;
+
+	if (existing->nr_blocks != new->v.nr_blocks) {
+		bch_err(trans->c, "error updating stripe: nr_blocks does not match");
+		ret = -EINVAL;
+		goto err;
+	}
 
+	for (i = 0; i < new->v.nr_blocks; i++)
+		stripe_blockcount_set(&new->v, i,
+			stripe_blockcount_get(existing, i));
+
+	ret = bch2_trans_update(trans, &iter, &new->k_i, 0);
+err:
+	bch2_trans_iter_exit(trans, &iter);
 	return ret;
 }
 
@@ -766,6 +807,7 @@ static void extent_stripe_ptr_add(struct bkey_s_extent e,
 	*dst = (struct bch_extent_stripe_ptr) {
 		.type = 1 << BCH_EXTENT_ENTRY_stripe_ptr,
 		.block		= block,
+		.redundancy	= s->key.v.nr_redundant,
 		.idx		= s->key.k.p.offset,
 	};
 }
@@ -775,63 +817,73 @@ static int ec_stripe_update_ptrs(struct bch_fs *c,
 				 struct bkey *pos)
 {
 	struct btree_trans trans;
-	struct btree_iter *iter;
+	struct btree_iter iter;
 	struct bkey_s_c k;
 	struct bkey_s_extent e;
-	struct bkey_on_stack sk;
-	int ret = 0, dev, idx;
+	struct bkey_buf sk;
+	struct bpos next_pos;
+	int ret = 0, dev, block;
 
-	bkey_on_stack_init(&sk);
+	bch2_bkey_buf_init(&sk);
 	bch2_trans_init(&trans, c, BTREE_ITER_MAX, 0);
 
-	iter = bch2_trans_get_iter(&trans, BTREE_ID_EXTENTS,
-				   bkey_start_pos(pos),
-				   BTREE_ITER_INTENT);
+	/* XXX this doesn't support the reflink btree */
 
-	while ((k = bch2_btree_iter_peek(iter)).k &&
+	bch2_trans_iter_init(&trans, &iter, BTREE_ID_extents,
+			     bkey_start_pos(pos),
+			     BTREE_ITER_INTENT);
+retry:
+	while (bch2_trans_begin(&trans),
+	       (k = bch2_btree_iter_peek(&iter)).k &&
 	       !(ret = bkey_err(k)) &&
 	       bkey_cmp(bkey_start_pos(k.k), pos->p) < 0) {
+		const struct bch_extent_ptr *ptr_c;
 		struct bch_extent_ptr *ptr, *ec_ptr = NULL;
 
 		if (extent_has_stripe_ptr(k, s->key.k.p.offset)) {
-			bch2_btree_iter_next(iter);
+			bch2_btree_iter_advance(&iter);
 			continue;
 		}
 
-		idx = extent_matches_stripe(c, &s->key.v, k);
-		if (idx < 0) {
-			bch2_btree_iter_next(iter);
+		ptr_c = bkey_matches_stripe(&s->key.v, k, &block);
+		/*
+		 * It doesn't generally make sense to erasure code cached ptrs:
+		 * XXX: should we be incrementing a counter?
+		 */
+		if (!ptr_c || ptr_c->cached) {
+			bch2_btree_iter_advance(&iter);
 			continue;
 		}
 
-		dev = s->key.v.ptrs[idx].dev;
+		dev = s->key.v.ptrs[block].dev;
 
-		bkey_on_stack_reassemble(&sk, c, k);
+		bch2_bkey_buf_reassemble(&sk, c, k);
 		e = bkey_i_to_s_extent(sk.k);
 
-		extent_for_each_ptr(e, ptr) {
-			if (ptr->dev == dev)
-				ec_ptr = ptr;
-			else
-				ptr->cached = true;
-		}
+		bch2_bkey_drop_ptrs(e.s, ptr, ptr->dev != dev);
+		ec_ptr = (void *) bch2_bkey_has_device(e.s_c, dev);
+		BUG_ON(!ec_ptr);
 
-		extent_stripe_ptr_add(e, s, ec_ptr, idx);
+		extent_stripe_ptr_add(e, s, ec_ptr, block);
 
-		bch2_btree_iter_set_pos(iter, bkey_start_pos(&sk.k->k));
-		bch2_trans_update(&trans, iter, sk.k, 0);
+		bch2_btree_iter_set_pos(&iter, bkey_start_pos(&sk.k->k));
+		next_pos = sk.k->k.p;
 
-		ret = bch2_trans_commit(&trans, NULL, NULL,
-					BTREE_INSERT_NOFAIL|
-					BTREE_INSERT_USE_RESERVE);
-		if (ret == -EINTR)
-			ret = 0;
+		ret   = bch2_btree_iter_traverse(&iter) ?:
+			bch2_trans_update(&trans, &iter, sk.k, 0) ?:
+			bch2_trans_commit(&trans, NULL, NULL,
+					BTREE_INSERT_NOFAIL);
+		if (!ret)
+			bch2_btree_iter_set_pos(&iter, next_pos);
 		if (ret)
 			break;
 	}
+	if (ret == -EINTR)
+		goto retry;
+	bch2_trans_iter_exit(&trans, &iter);
 
 	bch2_trans_exit(&trans);
-	bkey_on_stack_exit(&sk, c);
+	bch2_bkey_buf_exit(&sk, c);
 
 	return ret;
 }
@@ -844,94 +896,145 @@ static void ec_stripe_create(struct ec_stripe_new *s)
 	struct bch_fs *c = s->c;
 	struct open_bucket *ob;
 	struct bkey_i *k;
-	struct bch_stripe *v = &s->stripe.key.v;
+	struct stripe *m;
+	struct bch_stripe *v = &s->new_stripe.key.v;
 	unsigned i, nr_data = v->nr_blocks - v->nr_redundant;
-	struct closure cl;
 	int ret;
 
 	BUG_ON(s->h->s == s);
 
-	closure_init_stack(&cl);
+	closure_sync(&s->iodone);
 
 	if (s->err) {
-		bch_err(c, "error creating stripe: error writing data buckets");
+		if (s->err != -EROFS)
+			bch_err(c, "error creating stripe: error writing data buckets");
 		goto err;
 	}
 
-	if (!percpu_ref_tryget(&c->writes))
-		goto err;
+	if (s->have_existing_stripe) {
+		ec_validate_checksums(c, &s->existing_stripe);
+
+		if (ec_do_recov(c, &s->existing_stripe)) {
+			bch_err(c, "error creating stripe: error reading existing stripe");
+			goto err;
+		}
 
-	BUG_ON(bitmap_weight(s->blocks_allocated,
-			     s->blocks.nr) != s->blocks.nr);
+		for (i = 0; i < nr_data; i++)
+			if (stripe_blockcount_get(&s->existing_stripe.key.v, i))
+				swap(s->new_stripe.data[i],
+				     s->existing_stripe.data[i]);
 
-	ec_generate_ec(&s->stripe);
+		ec_stripe_buf_exit(&s->existing_stripe);
+	}
 
-	ec_generate_checksums(&s->stripe);
+	BUG_ON(!s->allocated);
 
-	/* write p/q: */
-	for (i = nr_data; i < v->nr_blocks; i++)
-		ec_block_io(c, &s->stripe, REQ_OP_WRITE, i, &cl);
+	if (!percpu_ref_tryget(&c->writes))
+		goto err;
 
-	closure_sync(&cl);
+	ec_generate_ec(&s->new_stripe);
+
+	ec_generate_checksums(&s->new_stripe);
 
+	/* write p/q: */
 	for (i = nr_data; i < v->nr_blocks; i++)
-		if (!test_bit(i, s->stripe.valid)) {
-			bch_err(c, "error creating stripe: error writing redundancy buckets");
-			goto err_put_writes;
-		}
+		ec_block_io(c, &s->new_stripe, REQ_OP_WRITE, i, &s->iodone);
+	closure_sync(&s->iodone);
 
-	mutex_lock(&c->ec_stripe_create_lock);
+	if (ec_nr_failed(&s->new_stripe)) {
+		bch_err(c, "error creating stripe: error writing redundancy buckets");
+		goto err_put_writes;
+	}
 
-	ret = ec_stripe_bkey_insert(c, &s->stripe.key);
+	ret = bch2_trans_do(c, &s->res, NULL, BTREE_INSERT_NOFAIL,
+			    s->have_existing_stripe
+			    ? ec_stripe_bkey_update(&trans, &s->new_stripe.key, &s->res)
+			    : ec_stripe_bkey_insert(&trans, &s->new_stripe.key, &s->res));
 	if (ret) {
 		bch_err(c, "error creating stripe: error creating stripe key");
-		goto err_unlock;
+		goto err_put_writes;
 	}
 
 	for_each_keylist_key(&s->keys, k) {
-		ret = ec_stripe_update_ptrs(c, &s->stripe, &k->k);
-		if (ret)
+		ret = ec_stripe_update_ptrs(c, &s->new_stripe, &k->k);
+		if (ret) {
+			bch_err(c, "error creating stripe: error %i updating pointers", ret);
 			break;
+		}
 	}
 
-err_unlock:
-	mutex_unlock(&c->ec_stripe_create_lock);
+	spin_lock(&c->ec_stripes_heap_lock);
+	m = genradix_ptr(&c->stripes, s->new_stripe.key.k.p.offset);
+
+	BUG_ON(m->on_heap);
+	bch2_stripes_heap_insert(c, m, s->new_stripe.key.k.p.offset);
+	spin_unlock(&c->ec_stripes_heap_lock);
 err_put_writes:
 	percpu_ref_put(&c->writes);
 err:
-	open_bucket_for_each(c, &s->blocks, ob, i) {
-		ob->ec = NULL;
-		__bch2_open_bucket_put(c, ob);
-	}
+	bch2_disk_reservation_put(c, &s->res);
 
-	bch2_open_buckets_put(c, &s->parity);
+	for (i = 0; i < v->nr_blocks; i++)
+		if (s->blocks[i]) {
+			ob = c->open_buckets + s->blocks[i];
+
+			if (i < nr_data) {
+				ob->ec = NULL;
+				__bch2_open_bucket_put(c, ob);
+			} else {
+				bch2_open_bucket_put(c, ob);
+			}
+		}
 
 	bch2_keylist_free(&s->keys, s->inline_keys);
 
-	mutex_lock(&s->h->lock);
-	list_del(&s->list);
-	mutex_unlock(&s->h->lock);
-
-	for (i = 0; i < s->stripe.key.v.nr_blocks; i++)
-		kvpfree(s->stripe.data[i], s->stripe.size << 9);
+	ec_stripe_buf_exit(&s->existing_stripe);
+	ec_stripe_buf_exit(&s->new_stripe);
+	closure_debug_destroy(&s->iodone);
 	kfree(s);
 }
 
-static struct ec_stripe_new *ec_stripe_set_pending(struct ec_stripe_head *h)
+static void ec_stripe_create_work(struct work_struct *work)
 {
-	struct ec_stripe_new *s = h->s;
+	struct bch_fs *c = container_of(work,
+		struct bch_fs, ec_stripe_create_work);
+	struct ec_stripe_new *s, *n;
+restart:
+	mutex_lock(&c->ec_stripe_new_lock);
+	list_for_each_entry_safe(s, n, &c->ec_stripe_new_list, list)
+		if (!atomic_read(&s->pin)) {
+			list_del(&s->list);
+			mutex_unlock(&c->ec_stripe_new_lock);
+			ec_stripe_create(s);
+			goto restart;
+		}
+	mutex_unlock(&c->ec_stripe_new_lock);
+}
 
-	list_add(&s->list, &h->stripes);
-	h->s = NULL;
+static void ec_stripe_new_put(struct bch_fs *c, struct ec_stripe_new *s)
+{
+	BUG_ON(atomic_read(&s->pin) <= 0);
 
-	return s;
+	if (atomic_dec_and_test(&s->pin)) {
+		BUG_ON(!s->pending);
+		queue_work(system_long_wq, &c->ec_stripe_create_work);
+	}
 }
 
-static void ec_stripe_new_put(struct ec_stripe_new *s)
+static void ec_stripe_set_pending(struct bch_fs *c, struct ec_stripe_head *h)
 {
-	BUG_ON(atomic_read(&s->pin) <= 0);
-	if (atomic_dec_and_test(&s->pin))
-		ec_stripe_create(s);
+	struct ec_stripe_new *s = h->s;
+
+	BUG_ON(!s->allocated && !s->err);
+
+	h->s		= NULL;
+	s->pending	= true;
+
+	mutex_lock(&c->ec_stripe_new_lock);
+	list_add(&s->list, &c->ec_stripe_new_list);
+	mutex_unlock(&c->ec_stripe_new_lock);
+
+	ec_stripe_new_put(c, s);
 }
 
 /* have a full bucket - hand it off to be erasure coded: */
@@ -942,7 +1045,7 @@ void bch2_ec_bucket_written(struct bch_fs *c, struct open_bucket *ob)
 	if (ob->sectors_free)
 		s->err = -1;
 
-	ec_stripe_new_put(s);
+	ec_stripe_new_put(c, s);
 }
 
 void bch2_ec_bucket_cancel(struct bch_fs *c, struct open_bucket *ob)
@@ -961,22 +1064,20 @@ void *bch2_writepoint_ec_buf(struct bch_fs *c, struct write_point *wp)
 	if (!ob)
 		return NULL;
 
-	ca	= bch_dev_bkey_exists(c, ob->ptr.dev);
+	ca	= bch_dev_bkey_exists(c, ob->dev);
 	offset	= ca->mi.bucket_size - ob->sectors_free;
 
-	return ob->ec->stripe.data[ob->ec_idx] + (offset << 9);
+	return ob->ec->new_stripe.data[ob->ec_idx] + (offset << 9);
 }
 
-void bch2_ec_add_backpointer(struct bch_fs *c, struct write_point *wp,
-			     struct bpos pos, unsigned sectors)
+void bch2_ob_add_backpointer(struct bch_fs *c, struct open_bucket *ob,
+			     struct bkey *k)
 {
-	struct open_bucket *ob = ec_open_bucket(c, &wp->ptrs);
-	struct ec_stripe_new *ec;
+	struct ec_stripe_new *ec = ob->ec;
 
-	if (!ob)
+	if (!ec)
 		return;
 
-	ec = ob->ec;
 	mutex_lock(&ec->lock);
 
 	if (bch2_keylist_realloc(&ec->keys, ec->inline_keys,
@@ -986,8 +1087,8 @@ void bch2_ec_add_backpointer(struct bch_fs *c, struct write_point *wp,
 	}
 
 	bkey_init(&ec->keys.top->k);
-	ec->keys.top->k.p	= pos;
-	bch2_key_resize(&ec->keys.top->k, sectors);
+	ec->keys.top->k.p	= k->p;
+	ec->keys.top->k.size	= k->size;
 	bch2_keylist_push(&ec->keys);
 
 	mutex_unlock(&ec->lock);
@@ -1034,14 +1135,42 @@ static unsigned pick_blocksize(struct bch_fs *c,
 	return best.size;
 }
 
-int bch2_ec_stripe_new_alloc(struct bch_fs *c, struct ec_stripe_head *h)
+static bool may_create_new_stripe(struct bch_fs *c)
+{
+	return false;
+}
+
+static void ec_stripe_key_init(struct bch_fs *c,
+			       struct bkey_i_stripe *s,
+			       unsigned nr_data,
+			       unsigned nr_parity,
+			       unsigned stripe_size)
+{
+	unsigned u64s;
+
+	bkey_stripe_init(&s->k_i);
+	s->v.sectors			= cpu_to_le16(stripe_size);
+	s->v.algorithm			= 0;
+	s->v.nr_blocks			= nr_data + nr_parity;
+	s->v.nr_redundant		= nr_parity;
+	s->v.csum_granularity_bits	= ilog2(c->opts.encoded_extent_max >> 9);
+	s->v.csum_type			= BCH_CSUM_crc32c;
+	s->v.pad			= 0;
+
+	while ((u64s = stripe_val_u64s(&s->v)) > BKEY_VAL_U64s_MAX) {
+		BUG_ON(1 << s->v.csum_granularity_bits >=
+		       le16_to_cpu(s->v.sectors) ||
+		       s->v.csum_granularity_bits == U8_MAX);
+		s->v.csum_granularity_bits++;
+	}
+
+	set_bkey_val_u64s(&s->k, u64s);
+}
+
+static int ec_new_stripe_alloc(struct bch_fs *c, struct ec_stripe_head *h)
 {
 	struct ec_stripe_new *s;
-	unsigned i;
 
-	BUG_ON(h->parity.nr != h->redundancy);
-	BUG_ON(!h->blocks.nr);
-	BUG_ON(h->parity.nr + h->blocks.nr > EC_STRIPE_MAX);
 	lockdep_assert_held(&h->lock);
 
 	s = kzalloc(sizeof(*s), GFP_KERNEL);
@@ -1049,44 +1178,27 @@ int bch2_ec_stripe_new_alloc(struct bch_fs *c, struct ec_stripe_head *h)
 		return -ENOMEM;
 
 	mutex_init(&s->lock);
+	closure_init(&s->iodone, NULL);
 	atomic_set(&s->pin, 1);
 	s->c		= c;
 	s->h		= h;
-	s->blocks	= h->blocks;
-	s->parity	= h->parity;
-
-	memset(&h->blocks, 0, sizeof(h->blocks));
-	memset(&h->parity, 0, sizeof(h->parity));
+	s->nr_data	= min_t(unsigned, h->nr_active_devs,
+				BCH_BKEY_PTRS_MAX) - h->redundancy;
+	s->nr_parity	= h->redundancy;
 
 	bch2_keylist_init(&s->keys, s->inline_keys);
 
-	s->stripe.offset	= 0;
-	s->stripe.size		= h->blocksize;
-	memset(s->stripe.valid, 0xFF, sizeof(s->stripe.valid));
-
-	ec_stripe_key_init(c, &s->stripe.key,
-			   &s->blocks, &s->parity,
-			   h->blocksize);
-
-	for (i = 0; i < s->stripe.key.v.nr_blocks; i++) {
-		s->stripe.data[i] = kvpmalloc(s->stripe.size << 9, GFP_KERNEL);
-		if (!s->stripe.data[i])
-			goto err;
-	}
+	ec_stripe_key_init(c, &s->new_stripe.key, s->nr_data,
+			   s->nr_parity, h->blocksize);
 
 	h->s = s;
-
 	return 0;
-err:
-	for (i = 0; i < s->stripe.key.v.nr_blocks; i++)
-		kvpfree(s->stripe.data[i], s->stripe.size << 9);
-	kfree(s);
-	return -ENOMEM;
 }
 
 static struct ec_stripe_head *
 ec_new_stripe_head_alloc(struct bch_fs *c, unsigned target,
-			 unsigned algo, unsigned redundancy)
+			 unsigned algo, unsigned redundancy,
+			 bool copygc)
 {
 	struct ec_stripe_head *h;
 	struct bch_dev *ca;
@@ -1098,14 +1210,14 @@ ec_new_stripe_head_alloc(struct bch_fs *c, unsigned target,
 
 	mutex_init(&h->lock);
 	mutex_lock(&h->lock);
-	INIT_LIST_HEAD(&h->stripes);
 
 	h->target	= target;
 	h->algo		= algo;
 	h->redundancy	= redundancy;
+	h->copygc	= copygc;
 
 	rcu_read_lock();
-	h->devs = target_rw_devs(c, BCH_DATA_USER, target);
+	h->devs = target_rw_devs(c, BCH_DATA_user, target);
 
 	for_each_member_device_rcu(ca, c, i, &h->devs)
 		if (!ca->mi.durability)
@@ -1118,219 +1230,426 @@ ec_new_stripe_head_alloc(struct bch_fs *c, unsigned target,
 			h->nr_active_devs++;
 
 	rcu_read_unlock();
-	list_add(&h->list, &c->ec_new_stripe_list);
+	list_add(&h->list, &c->ec_stripe_head_list);
 	return h;
 }
 
-void bch2_ec_stripe_head_put(struct ec_stripe_head *h)
+void bch2_ec_stripe_head_put(struct bch_fs *c, struct ec_stripe_head *h)
 {
-	struct ec_stripe_new *s = NULL;
-
 	if (h->s &&
+	    h->s->allocated &&
 	    bitmap_weight(h->s->blocks_allocated,
-			  h->s->blocks.nr) == h->s->blocks.nr)
-		s = ec_stripe_set_pending(h);
+			  h->s->nr_data) == h->s->nr_data)
+		ec_stripe_set_pending(c, h);
 
 	mutex_unlock(&h->lock);
-
-	if (s)
-		ec_stripe_new_put(s);
 }
 
-struct ec_stripe_head *bch2_ec_stripe_head_get(struct bch_fs *c,
-					       unsigned target,
-					       unsigned algo,
-					       unsigned redundancy)
+struct ec_stripe_head *__bch2_ec_stripe_head_get(struct bch_fs *c,
+						 unsigned target,
+						 unsigned algo,
+						 unsigned redundancy,
+						 bool copygc)
 {
 	struct ec_stripe_head *h;
 
 	if (!redundancy)
 		return NULL;
 
-	mutex_lock(&c->ec_new_stripe_lock);
-	list_for_each_entry(h, &c->ec_new_stripe_list, list)
+	mutex_lock(&c->ec_stripe_head_lock);
+	list_for_each_entry(h, &c->ec_stripe_head_list, list)
 		if (h->target		== target &&
 		    h->algo		== algo &&
-		    h->redundancy	== redundancy) {
+		    h->redundancy	== redundancy &&
+		    h->copygc		== copygc) {
 			mutex_lock(&h->lock);
 			goto found;
 		}
 
-	h = ec_new_stripe_head_alloc(c, target, algo, redundancy);
+	h = ec_new_stripe_head_alloc(c, target, algo, redundancy, copygc);
 found:
-	mutex_unlock(&c->ec_new_stripe_lock);
+	mutex_unlock(&c->ec_stripe_head_lock);
 	return h;
 }
 
-void bch2_ec_stop_dev(struct bch_fs *c, struct bch_dev *ca)
+static int new_stripe_alloc_buckets(struct bch_fs *c, struct ec_stripe_head *h,
+				    struct closure *cl)
 {
-	struct ec_stripe_head *h;
+	struct bch_devs_mask devs = h->devs;
 	struct open_bucket *ob;
-	unsigned i;
+	struct open_buckets buckets;
+	unsigned i, j, nr_have_parity = 0, nr_have_data = 0;
+	bool have_cache = true;
+	int ret = 0;
 
-	mutex_lock(&c->ec_new_stripe_lock);
-	list_for_each_entry(h, &c->ec_new_stripe_list, list) {
-		struct ec_stripe_new *s = NULL;
+	for (i = 0; i < h->s->new_stripe.key.v.nr_blocks; i++) {
+		if (test_bit(i, h->s->blocks_gotten)) {
+			__clear_bit(h->s->new_stripe.key.v.ptrs[i].dev, devs.d);
+			if (i < h->s->nr_data)
+				nr_have_data++;
+			else
+				nr_have_parity++;
+		}
+	}
 
-		mutex_lock(&h->lock);
-		bch2_open_buckets_stop_dev(c, ca, &h->blocks);
-		bch2_open_buckets_stop_dev(c, ca, &h->parity);
+	BUG_ON(nr_have_data	> h->s->nr_data);
+	BUG_ON(nr_have_parity	> h->s->nr_parity);
 
-		if (!h->s)
-			goto unlock;
+	percpu_down_read(&c->mark_lock);
+	rcu_read_lock();
 
-		open_bucket_for_each(c, &h->s->blocks, ob, i)
-			if (ob->ptr.dev == ca->dev_idx)
-				goto found;
-		open_bucket_for_each(c, &h->s->parity, ob, i)
-			if (ob->ptr.dev == ca->dev_idx)
-				goto found;
-		goto unlock;
-found:
-		h->s->err = -1;
-		s = ec_stripe_set_pending(h);
-unlock:
-		mutex_unlock(&h->lock);
+	buckets.nr = 0;
+	if (nr_have_parity < h->s->nr_parity) {
+		ret = bch2_bucket_alloc_set(c, &buckets,
+					    &h->parity_stripe,
+					    &devs,
+					    h->s->nr_parity,
+					    &nr_have_parity,
+					    &have_cache,
+					    h->copygc
+					    ? RESERVE_MOVINGGC
+					    : RESERVE_NONE,
+					    0,
+					    cl);
+
+		open_bucket_for_each(c, &buckets, ob, i) {
+			j = find_next_zero_bit(h->s->blocks_gotten,
+					       h->s->nr_data + h->s->nr_parity,
+					       h->s->nr_data);
+			BUG_ON(j >= h->s->nr_data + h->s->nr_parity);
+
+			h->s->blocks[j] = buckets.v[i];
+			h->s->new_stripe.key.v.ptrs[j] = bch2_ob_ptr(c, ob);
+			__set_bit(j, h->s->blocks_gotten);
+		}
+
+		if (ret)
+			goto err;
+	}
+
+	buckets.nr = 0;
+	if (nr_have_data < h->s->nr_data) {
+		ret = bch2_bucket_alloc_set(c, &buckets,
+					    &h->block_stripe,
+					    &devs,
+					    h->s->nr_data,
+					    &nr_have_data,
+					    &have_cache,
+					    h->copygc
+					    ? RESERVE_MOVINGGC
+					    : RESERVE_NONE,
+					    0,
+					    cl);
+
+		open_bucket_for_each(c, &buckets, ob, i) {
+			j = find_next_zero_bit(h->s->blocks_gotten,
+					       h->s->nr_data, 0);
+			BUG_ON(j >= h->s->nr_data);
+
+			h->s->blocks[j] = buckets.v[i];
+			h->s->new_stripe.key.v.ptrs[j] = bch2_ob_ptr(c, ob);
+			__set_bit(j, h->s->blocks_gotten);
+		}
 
-		if (s)
-			ec_stripe_new_put(s);
+		if (ret)
+			goto err;
 	}
-	mutex_unlock(&c->ec_new_stripe_lock);
+err:
+	rcu_read_unlock();
+	percpu_up_read(&c->mark_lock);
+	return ret;
 }
 
-static int __bch2_stripe_write_key(struct btree_trans *trans,
-				   struct btree_iter *iter,
-				   struct stripe *m,
-				   size_t idx,
-				   struct bkey_i_stripe *new_key)
+/* XXX: doesn't obey target: */
+static s64 get_existing_stripe(struct bch_fs *c,
+			       struct ec_stripe_head *head)
+{
+	ec_stripes_heap *h = &c->ec_stripes_heap;
+	struct stripe *m;
+	size_t heap_idx;
+	u64 stripe_idx;
+	s64 ret = -1;
+
+	if (may_create_new_stripe(c))
+		return -1;
+
+	spin_lock(&c->ec_stripes_heap_lock);
+	for (heap_idx = 0; heap_idx < h->used; heap_idx++) {
+		/* No blocks worth reusing, stripe will just be deleted: */
+		if (!h->data[heap_idx].blocks_nonempty)
+			continue;
+
+		stripe_idx = h->data[heap_idx].idx;
+		m = genradix_ptr(&c->stripes, stripe_idx);
+
+		if (m->algorithm	== head->algo &&
+		    m->nr_redundant	== head->redundancy &&
+		    m->sectors		== head->blocksize &&
+		    m->blocks_nonempty	< m->nr_blocks - m->nr_redundant) {
+			bch2_stripes_heap_del(c, m, stripe_idx);
+			ret = stripe_idx;
+			break;
+		}
+	}
+	spin_unlock(&c->ec_stripes_heap_lock);
+	return ret;
+}
+
+static int __bch2_ec_stripe_head_reuse(struct bch_fs *c,
+						   struct ec_stripe_head *h)
 {
-	struct bch_fs *c = trans->c;
-	struct bkey_s_c k;
 	unsigned i;
+	s64 idx;
 	int ret;
 
-	bch2_btree_iter_set_pos(iter, POS(0, idx));
+	idx = get_existing_stripe(c, h);
+	if (idx < 0) {
+		bch_err(c, "failed to find an existing stripe");
+		return -ENOSPC;
+	}
 
-	k = bch2_btree_iter_peek_slot(iter);
-	ret = bkey_err(k);
-	if (ret)
+	h->s->have_existing_stripe = true;
+	ret = get_stripe_key(c, idx, &h->s->existing_stripe);
+	if (ret) {
+		bch2_fs_fatal_error(c, "error reading stripe key: %i", ret);
 		return ret;
+	}
 
-	if (k.k->type != KEY_TYPE_stripe)
-		return -EIO;
+	if (ec_stripe_buf_init(&h->s->existing_stripe, 0, h->blocksize)) {
+		/*
+		 * this is a problem: we have deleted from the
+		 * stripes heap already
+		 */
+		BUG();
+	}
 
-	bkey_reassemble(&new_key->k_i, k);
+	BUG_ON(h->s->existing_stripe.size != h->blocksize);
+	BUG_ON(h->s->existing_stripe.size != h->s->existing_stripe.key.v.sectors);
 
-	spin_lock(&c->ec_stripes_heap_lock);
+	for (i = 0; i < h->s->existing_stripe.key.v.nr_blocks; i++) {
+		if (stripe_blockcount_get(&h->s->existing_stripe.key.v, i)) {
+			__set_bit(i, h->s->blocks_gotten);
+			__set_bit(i, h->s->blocks_allocated);
+		}
 
-	for (i = 0; i < new_key->v.nr_blocks; i++)
-		stripe_blockcount_set(&new_key->v, i,
-				      m->block_sectors[i]);
-	m->dirty = false;
+		ec_block_io(c, &h->s->existing_stripe, READ, i, &h->s->iodone);
+	}
 
-	spin_unlock(&c->ec_stripes_heap_lock);
+	bkey_copy(&h->s->new_stripe.key.k_i,
+			&h->s->existing_stripe.key.k_i);
 
-	bch2_trans_update(trans, iter, &new_key->k_i, 0);
 	return 0;
 }
 
-int bch2_stripes_write(struct bch_fs *c, unsigned flags, bool *wrote)
+static int __bch2_ec_stripe_head_reserve(struct bch_fs *c,
+							struct ec_stripe_head *h)
 {
-	struct btree_trans trans;
-	struct btree_iter *iter;
-	struct genradix_iter giter;
-	struct bkey_i_stripe *new_key;
-	struct stripe *m;
-	int ret = 0;
+	int ret;
 
-	new_key = kmalloc(255 * sizeof(u64), GFP_KERNEL);
-	BUG_ON(!new_key);
+	ret = bch2_disk_reservation_get(c, &h->s->res,
+			h->blocksize,
+			h->s->nr_parity, 0);
 
-	bch2_trans_init(&trans, c, 0, 0);
+	if (ret) {
+		/*
+		 * This means we need to wait for copygc to
+		 * empty out buckets from existing stripes:
+		 */
+		bch_err(c, "failed to reserve stripe");
+	}
 
-	iter = bch2_trans_get_iter(&trans, BTREE_ID_EC, POS_MIN,
-				   BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+	return ret;
+}
 
-	genradix_for_each(&c->stripes[0], giter, m) {
-		if (!m->dirty)
-			continue;
+struct ec_stripe_head *bch2_ec_stripe_head_get(struct bch_fs *c,
+					       unsigned target,
+					       unsigned algo,
+					       unsigned redundancy,
+					       bool copygc,
+					       struct closure *cl)
+{
+	struct ec_stripe_head *h;
+	int ret;
+	bool needs_stripe_new;
 
-		ret = __bch2_trans_do(&trans, NULL, NULL,
-				      BTREE_INSERT_NOFAIL|flags,
-			__bch2_stripe_write_key(&trans, iter, m,
-					giter.pos, new_key));
+	h = __bch2_ec_stripe_head_get(c, target, algo, redundancy, copygc);
+	if (!h) {
+		bch_err(c, "no stripe head");
+		return NULL;
+	}
 
-		if (ret)
-			break;
+	needs_stripe_new = !h->s;
+	if (needs_stripe_new) {
+		if (ec_new_stripe_alloc(c, h)) {
+			ret = -ENOMEM;
+			bch_err(c, "failed to allocate new stripe");
+			goto err;
+		}
 
-		*wrote = true;
+		if (ec_stripe_buf_init(&h->s->new_stripe, 0, h->blocksize))
+			BUG();
 	}
 
-	bch2_trans_exit(&trans);
+	/*
+	 * Try reserve a new stripe before reusing an
+	 * existing stripe. This will prevent unnecessary
+	 * read amplification during write oriented workloads.
+	 */
+	ret = 0;
+	if (!h->s->allocated && !h->s->res.sectors && !h->s->have_existing_stripe)
+		ret = __bch2_ec_stripe_head_reserve(c, h);
+	if (ret && needs_stripe_new)
+		ret = __bch2_ec_stripe_head_reuse(c, h);
+	if (ret)
+		goto err;
 
-	kfree(new_key);
+	if (!h->s->allocated) {
+		ret = new_stripe_alloc_buckets(c, h, cl);
+		if (ret)
+			goto err;
 
-	return ret;
+		h->s->allocated = true;
+	}
+
+	return h;
+
+err:
+	bch2_ec_stripe_head_put(c, h);
+	return ERR_PTR(ret);
 }
 
-static int bch2_stripes_read_fn(struct bch_fs *c, enum btree_id id,
-			      unsigned level, struct bkey_s_c k)
+void bch2_ec_stop_dev(struct bch_fs *c, struct bch_dev *ca)
 {
-	int ret = 0;
+	struct ec_stripe_head *h;
+	struct open_bucket *ob;
+	unsigned i;
 
-	if (k.k->type == KEY_TYPE_stripe)
-		ret = __ec_stripe_mem_alloc(c, k.k->p.offset, GFP_KERNEL) ?:
-			bch2_mark_key(c, k, 0, 0, NULL, 0,
-				      BTREE_TRIGGER_ALLOC_READ|
-				      BTREE_TRIGGER_NOATOMIC);
+	mutex_lock(&c->ec_stripe_head_lock);
+	list_for_each_entry(h, &c->ec_stripe_head_list, list) {
 
-	return ret;
+		mutex_lock(&h->lock);
+		if (!h->s)
+			goto unlock;
+
+		for (i = 0; i < h->s->new_stripe.key.v.nr_blocks; i++) {
+			if (!h->s->blocks[i])
+				continue;
+
+			ob = c->open_buckets + h->s->blocks[i];
+			if (ob->dev == ca->dev_idx)
+				goto found;
+		}
+		goto unlock;
+found:
+		h->s->err = -EROFS;
+		ec_stripe_set_pending(c, h);
+unlock:
+		mutex_unlock(&h->lock);
+	}
+	mutex_unlock(&c->ec_stripe_head_lock);
 }
 
-int bch2_stripes_read(struct bch_fs *c, struct journal_keys *journal_keys)
+void bch2_stripes_heap_start(struct bch_fs *c)
 {
-	int ret = bch2_btree_and_journal_walk(c, journal_keys, BTREE_ID_EC,
-					  NULL, bch2_stripes_read_fn);
-	if (ret)
-		bch_err(c, "error reading stripes: %i", ret);
+	struct genradix_iter iter;
+	struct stripe *m;
 
-	return ret;
+	genradix_for_each(&c->stripes, iter, m)
+		if (m->alive)
+			bch2_stripes_heap_insert(c, m, iter.pos);
 }
 
-int bch2_ec_mem_alloc(struct bch_fs *c, bool gc)
+int bch2_stripes_read(struct bch_fs *c)
 {
 	struct btree_trans trans;
-	struct btree_iter *iter;
+	struct btree_iter iter;
 	struct bkey_s_c k;
-	size_t i, idx = 0;
-	int ret = 0;
+	const struct bch_stripe *s;
+	struct stripe *m;
+	unsigned i;
+	int ret;
 
 	bch2_trans_init(&trans, c, 0, 0);
 
-	iter = bch2_trans_get_iter(&trans, BTREE_ID_EC, POS(0, U64_MAX), 0);
+	for_each_btree_key(&trans, iter, BTREE_ID_stripes, POS_MIN,
+			   BTREE_ITER_PREFETCH, k, ret) {
+		if (k.k->type != KEY_TYPE_stripe)
+			continue;
+
+		ret = __ec_stripe_mem_alloc(c, k.k->p.offset, GFP_KERNEL);
+		if (ret)
+			break;
+
+		s = bkey_s_c_to_stripe(k).v;
+
+		m = genradix_ptr(&c->stripes, k.k->p.offset);
+		m->alive	= true;
+		m->sectors	= le16_to_cpu(s->sectors);
+		m->algorithm	= s->algorithm;
+		m->nr_blocks	= s->nr_blocks;
+		m->nr_redundant	= s->nr_redundant;
+		m->blocks_nonempty = 0;
+
+		for (i = 0; i < s->nr_blocks; i++)
+			m->blocks_nonempty += !!stripe_blockcount_get(s, i);
+
+		spin_lock(&c->ec_stripes_heap_lock);
+		bch2_stripes_heap_update(c, m, k.k->p.offset);
+		spin_unlock(&c->ec_stripes_heap_lock);
+	}
+	bch2_trans_iter_exit(&trans, &iter);
+
+	bch2_trans_exit(&trans);
 
-	k = bch2_btree_iter_prev(iter);
-	if (!IS_ERR_OR_NULL(k.k))
-		idx = k.k->p.offset + 1;
-	ret = bch2_trans_exit(&trans);
 	if (ret)
-		return ret;
+		bch_err(c, "error reading stripes: %i", ret);
 
-	if (!idx)
-		return 0;
+	return ret;
+}
 
-	if (!gc &&
-	    !init_heap(&c->ec_stripes_heap, roundup_pow_of_two(idx),
-		       GFP_KERNEL))
-		return -ENOMEM;
-#if 0
-	ret = genradix_prealloc(&c->stripes[gc], idx, GFP_KERNEL);
-#else
-	for (i = 0; i < idx; i++)
-		if (!genradix_ptr_alloc(&c->stripes[gc], i, GFP_KERNEL))
-			return -ENOMEM;
-#endif
-	return 0;
+void bch2_stripes_heap_to_text(struct printbuf *out, struct bch_fs *c)
+{
+	ec_stripes_heap *h = &c->ec_stripes_heap;
+	struct stripe *m;
+	size_t i;
+
+	spin_lock(&c->ec_stripes_heap_lock);
+	for (i = 0; i < min_t(size_t, h->used, 20); i++) {
+		m = genradix_ptr(&c->stripes, h->data[i].idx);
+
+		pr_buf(out, "%zu %u/%u+%u\n", h->data[i].idx,
+		       h->data[i].blocks_nonempty,
+		       m->nr_blocks - m->nr_redundant,
+		       m->nr_redundant);
+	}
+	spin_unlock(&c->ec_stripes_heap_lock);
+}
+
+void bch2_new_stripes_to_text(struct printbuf *out, struct bch_fs *c)
+{
+	struct ec_stripe_head *h;
+	struct ec_stripe_new *s;
+
+	mutex_lock(&c->ec_stripe_head_lock);
+	list_for_each_entry(h, &c->ec_stripe_head_list, list) {
+		pr_buf(out, "target %u algo %u redundancy %u:\n",
+		       h->target, h->algo, h->redundancy);
+
+		if (h->s)
+			pr_buf(out, "\tpending: blocks %u+%u allocated %u\n",
+			       h->s->nr_data, h->s->nr_parity,
+			       bitmap_weight(h->s->blocks_allocated,
+					     h->s->nr_data));
+	}
+	mutex_unlock(&c->ec_stripe_head_lock);
+
+	mutex_lock(&c->ec_stripe_new_lock);
+	list_for_each_entry(s, &c->ec_stripe_new_list, list) {
+		pr_buf(out, "\tin flight: blocks %u+%u pin %u\n",
+		       s->nr_data, s->nr_parity,
+		       atomic_read(&s->pin));
+	}
+	mutex_unlock(&c->ec_stripe_new_lock);
 }
 
 void bch2_fs_ec_exit(struct bch_fs *c)
@@ -1338,27 +1657,29 @@ void bch2_fs_ec_exit(struct bch_fs *c)
 	struct ec_stripe_head *h;
 
 	while (1) {
-		mutex_lock(&c->ec_new_stripe_lock);
-		h = list_first_entry_or_null(&c->ec_new_stripe_list,
+		mutex_lock(&c->ec_stripe_head_lock);
+		h = list_first_entry_or_null(&c->ec_stripe_head_list,
 					     struct ec_stripe_head, list);
 		if (h)
 			list_del(&h->list);
-		mutex_unlock(&c->ec_new_stripe_lock);
+		mutex_unlock(&c->ec_stripe_head_lock);
 		if (!h)
 			break;
 
 		BUG_ON(h->s);
-		BUG_ON(!list_empty(&h->stripes));
 		kfree(h);
 	}
 
+	BUG_ON(!list_empty(&c->ec_stripe_new_list));
+
 	free_heap(&c->ec_stripes_heap);
-	genradix_free(&c->stripes[0]);
+	genradix_free(&c->stripes);
 	bioset_exit(&c->ec_bioset);
 }
 
 int bch2_fs_ec_init(struct bch_fs *c)
 {
+	INIT_WORK(&c->ec_stripe_create_work, ec_stripe_create_work);
 	INIT_WORK(&c->ec_stripe_delete_work, ec_stripe_delete_work);
 
 	return bioset_init(&c->ec_bioset, 1, offsetof(struct ec_bio, bio),