bcachefs: btree_journal_iter.c

Split out a new file from recovery.c for managing the list of keys we
read from the journal: before journal replay finishes the btree iterator
code needs to be able to iterate over and return keys from the journal
as well, so there's a fair bit of code here.

Signed-off-by: Kent Overstreet <[e-mail]>

fs/bcachefs/Makefile

···
 	btree_gc.o		\
 	btree_io.o		\
 	btree_iter.o		\
+	btree_journal_iter.o	\
 	btree_key_cache.o	\
 	btree_locking.o		\
 	btree_trans_commit.o	\

fs/bcachefs/btree_gc.c

···
 #include "alloc_foreground.h"
 #include "bkey_methods.h"
 #include "bkey_buf.h"
+#include "btree_journal_iter.h"
 #include "btree_key_cache.h"
 #include "btree_locking.h"
 #include "btree_update_interior.h"

fs/bcachefs/btree_iter.c

···
 #include "bkey_buf.h"
 #include "btree_cache.h"
 #include "btree_iter.h"
+#include "btree_journal_iter.h"
 #include "btree_key_cache.h"
 #include "btree_locking.h"
 #include "btree_update.h"
···
 #include "error.h"
 #include "extents.h"
 #include "journal.h"
-#include "recovery.h"
 #include "replicas.h"
 #include "subvolume.h"
 #include "trace.h"

fs/bcachefs/btree_journal_iter.c

···
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "bset.h"
+#include "btree_journal_iter.h"
+#include "journal_io.h"
+
+#include <linux/sort.h>
+
+/*
+ * For managing keys we read from the journal: until journal replay works normal
+ * btree lookups need to be able to find and return keys from the journal where
+ * they overwrite what's in the btree, so we have a special iterator and
+ * operations for the regular btree iter code to use:
+ */
+
+static int __journal_key_cmp(enum btree_id	l_btree_id,
+			     unsigned		l_level,
+			     struct bpos	l_pos,
+			     const struct journal_key *r)
+{
+	return (cmp_int(l_btree_id,	r->btree_id) ?:
+		cmp_int(l_level,	r->level) ?:
+		bpos_cmp(l_pos,	r->k->k.p));
+}
+
+static int journal_key_cmp(const struct journal_key *l, const struct journal_key *r)
+{
+	return __journal_key_cmp(l->btree_id, l->level, l->k->k.p, r);
+}
+
+static inline size_t idx_to_pos(struct journal_keys *keys, size_t idx)
+{
+	size_t gap_size = keys->size - keys->nr;
+
+	if (idx >= keys->gap)
+		idx += gap_size;
+	return idx;
+}
+
+static inline struct journal_key *idx_to_key(struct journal_keys *keys, size_t idx)
+{
+	return keys->d + idx_to_pos(keys, idx);
+}
+
+static size_t __bch2_journal_key_search(struct journal_keys *keys,
+					enum btree_id id, unsigned level,
+					struct bpos pos)
+{
+	size_t l = 0, r = keys->nr, m;
+
+	while (l < r) {
+		m = l + ((r - l) >> 1);
+		if (__journal_key_cmp(id, level, pos, idx_to_key(keys, m)) > 0)
+			l = m + 1;
+		else
+			r = m;
+	}
+
+	BUG_ON(l < keys->nr &&
+	       __journal_key_cmp(id, level, pos, idx_to_key(keys, l)) > 0);
+
+	BUG_ON(l &&
+	       __journal_key_cmp(id, level, pos, idx_to_key(keys, l - 1)) <= 0);
+
+	return l;
+}
+
+static size_t bch2_journal_key_search(struct journal_keys *keys,
+				      enum btree_id id, unsigned level,
+				      struct bpos pos)
+{
+	return idx_to_pos(keys, __bch2_journal_key_search(keys, id, level, pos));
+}
+
+struct bkey_i *bch2_journal_keys_peek_upto(struct bch_fs *c, enum btree_id btree_id,
+					   unsigned level, struct bpos pos,
+					   struct bpos end_pos, size_t *idx)
+{
+	struct journal_keys *keys = &c->journal_keys;
+	unsigned iters = 0;
+	struct journal_key *k;
+search:
+	if (!*idx)
+		*idx = __bch2_journal_key_search(keys, btree_id, level, pos);
+
+	while ((k = *idx < keys->nr ? idx_to_key(keys, *idx) : NULL)) {
+		if (__journal_key_cmp(btree_id, level, end_pos, k) < 0)
+			return NULL;
+
+		if (__journal_key_cmp(btree_id, level, pos, k) <= 0 &&
+		    !k->overwritten)
+			return k->k;
+
+		(*idx)++;
+		iters++;
+		if (iters == 10) {
+			*idx = 0;
+			goto search;
+		}
+	}
+
+	return NULL;
+}
+
+struct bkey_i *bch2_journal_keys_peek_slot(struct bch_fs *c, enum btree_id btree_id,
+					   unsigned level, struct bpos pos)
+{
+	size_t idx = 0;
+
+	return bch2_journal_keys_peek_upto(c, btree_id, level, pos, pos, &idx);
+}
+
+static void journal_iters_fix(struct bch_fs *c)
+{
+	struct journal_keys *keys = &c->journal_keys;
+	/* The key we just inserted is immediately before the gap: */
+	size_t gap_end = keys->gap + (keys->size - keys->nr);
+	struct btree_and_journal_iter *iter;
+
+	/*
+	 * If an iterator points one after the key we just inserted, decrement
+	 * the iterator so it points at the key we just inserted - if the
+	 * decrement was unnecessary, bch2_btree_and_journal_iter_peek() will
+	 * handle that:
+	 */
+	list_for_each_entry(iter, &c->journal_iters, journal.list)
+		if (iter->journal.idx == gap_end)
+			iter->journal.idx = keys->gap - 1;
+}
+
+static void journal_iters_move_gap(struct bch_fs *c, size_t old_gap, size_t new_gap)
+{
+	struct journal_keys *keys = &c->journal_keys;
+	struct journal_iter *iter;
+	size_t gap_size = keys->size - keys->nr;
+
+	list_for_each_entry(iter, &c->journal_iters, list) {
+		if (iter->idx > old_gap)
+			iter->idx -= gap_size;
+		if (iter->idx >= new_gap)
+			iter->idx += gap_size;
+	}
+}
+
+int bch2_journal_key_insert_take(struct bch_fs *c, enum btree_id id,
+				 unsigned level, struct bkey_i *k)
+{
+	struct journal_key n = {
+		.btree_id	= id,
+		.level		= level,
+		.k		= k,
+		.allocated	= true,
+		/*
+		 * Ensure these keys are done last by journal replay, to unblock
+		 * journal reclaim:
+		 */
+		.journal_seq	= U32_MAX,
+	};
+	struct journal_keys *keys = &c->journal_keys;
+	size_t idx = bch2_journal_key_search(keys, id, level, k->k.p);
+
+	BUG_ON(test_bit(BCH_FS_RW, &c->flags));
+
+	if (idx < keys->size &&
+	    journal_key_cmp(&n, &keys->d[idx]) == 0) {
+		if (keys->d[idx].allocated)
+			kfree(keys->d[idx].k);
+		keys->d[idx] = n;
+		return 0;
+	}
+
+	if (idx > keys->gap)
+		idx -= keys->size - keys->nr;
+
+	if (keys->nr == keys->size) {
+		struct journal_keys new_keys = {
+			.nr			= keys->nr,
+			.size			= max_t(size_t, keys->size, 8) * 2,
+		};
+
+		new_keys.d = kvmalloc_array(new_keys.size, sizeof(new_keys.d[0]), GFP_KERNEL);
+		if (!new_keys.d) {
+			bch_err(c, "%s: error allocating new key array (size %zu)",
+				__func__, new_keys.size);
+			return -BCH_ERR_ENOMEM_journal_key_insert;
+		}
+
+		/* Since @keys was full, there was no gap: */
+		memcpy(new_keys.d, keys->d, sizeof(keys->d[0]) * keys->nr);
+		kvfree(keys->d);
+		*keys = new_keys;
+
+		/* And now the gap is at the end: */
+		keys->gap = keys->nr;
+	}
+
+	journal_iters_move_gap(c, keys->gap, idx);
+
+	move_gap(keys->d, keys->nr, keys->size, keys->gap, idx);
+	keys->gap = idx;
+
+	keys->nr++;
+	keys->d[keys->gap++] = n;
+
+	journal_iters_fix(c);
+
+	return 0;
+}
+
+/*
+ * Can only be used from the recovery thread while we're still RO - can't be
+ * used once we've got RW, as journal_keys is at that point used by multiple
+ * threads:
+ */
+int bch2_journal_key_insert(struct bch_fs *c, enum btree_id id,
+			    unsigned level, struct bkey_i *k)
+{
+	struct bkey_i *n;
+	int ret;
+
+	n = kmalloc(bkey_bytes(&k->k), GFP_KERNEL);
+	if (!n)
+		return -BCH_ERR_ENOMEM_journal_key_insert;
+
+	bkey_copy(n, k);
+	ret = bch2_journal_key_insert_take(c, id, level, n);
+	if (ret)
+		kfree(n);
+	return ret;
+}
+
+int bch2_journal_key_delete(struct bch_fs *c, enum btree_id id,
+			    unsigned level, struct bpos pos)
+{
+	struct bkey_i whiteout;
+
+	bkey_init(&whiteout.k);
+	whiteout.k.p = pos;
+
+	return bch2_journal_key_insert(c, id, level, &whiteout);
+}
+
+void bch2_journal_key_overwritten(struct bch_fs *c, enum btree_id btree,
+				  unsigned level, struct bpos pos)
+{
+	struct journal_keys *keys = &c->journal_keys;
+	size_t idx = bch2_journal_key_search(keys, btree, level, pos);
+
+	if (idx < keys->size &&
+	    keys->d[idx].btree_id	== btree &&
+	    keys->d[idx].level		== level &&
+	    bpos_eq(keys->d[idx].k->k.p, pos))
+		keys->d[idx].overwritten = true;
+}
+
+static void bch2_journal_iter_advance(struct journal_iter *iter)
+{
+	if (iter->idx < iter->keys->size) {
+		iter->idx++;
+		if (iter->idx == iter->keys->gap)
+			iter->idx += iter->keys->size - iter->keys->nr;
+	}
+}
+
+static struct bkey_s_c bch2_journal_iter_peek(struct journal_iter *iter)
+{
+	struct journal_key *k = iter->keys->d + iter->idx;
+
+	while (k < iter->keys->d + iter->keys->size &&
+	       k->btree_id	== iter->btree_id &&
+	       k->level		== iter->level) {
+		if (!k->overwritten)
+			return bkey_i_to_s_c(k->k);
+
+		bch2_journal_iter_advance(iter);
+		k = iter->keys->d + iter->idx;
+	}
+
+	return bkey_s_c_null;
+}
+
+static void bch2_journal_iter_exit(struct journal_iter *iter)
+{
+	list_del(&iter->list);
+}
+
+static void bch2_journal_iter_init(struct bch_fs *c,
+				   struct journal_iter *iter,
+				   enum btree_id id, unsigned level,
+				   struct bpos pos)
+{
+	iter->btree_id	= id;
+	iter->level	= level;
+	iter->keys	= &c->journal_keys;
+	iter->idx	= bch2_journal_key_search(&c->journal_keys, id, level, pos);
+}
+
+static struct bkey_s_c bch2_journal_iter_peek_btree(struct btree_and_journal_iter *iter)
+{
+	return bch2_btree_node_iter_peek_unpack(&iter->node_iter,
+						iter->b, &iter->unpacked);
+}
+
+static void bch2_journal_iter_advance_btree(struct btree_and_journal_iter *iter)
+{
+	bch2_btree_node_iter_advance(&iter->node_iter, iter->b);
+}
+
+void bch2_btree_and_journal_iter_advance(struct btree_and_journal_iter *iter)
+{
+	if (bpos_eq(iter->pos, SPOS_MAX))
+		iter->at_end = true;
+	else
+		iter->pos = bpos_successor(iter->pos);
+}
+
+struct bkey_s_c bch2_btree_and_journal_iter_peek(struct btree_and_journal_iter *iter)
+{
+	struct bkey_s_c btree_k, journal_k, ret;
+again:
+	if (iter->at_end)
+		return bkey_s_c_null;
+
+	while ((btree_k = bch2_journal_iter_peek_btree(iter)).k &&
+	       bpos_lt(btree_k.k->p, iter->pos))
+		bch2_journal_iter_advance_btree(iter);
+
+	while ((journal_k = bch2_journal_iter_peek(&iter->journal)).k &&
+	       bpos_lt(journal_k.k->p, iter->pos))
+		bch2_journal_iter_advance(&iter->journal);
+
+	ret = journal_k.k &&
+		(!btree_k.k || bpos_le(journal_k.k->p, btree_k.k->p))
+		? journal_k
+		: btree_k;
+
+	if (ret.k && iter->b && bpos_gt(ret.k->p, iter->b->data->max_key))
+		ret = bkey_s_c_null;
+
+	if (ret.k) {
+		iter->pos = ret.k->p;
+		if (bkey_deleted(ret.k)) {
+			bch2_btree_and_journal_iter_advance(iter);
+			goto again;
+		}
+	} else {
+		iter->pos = SPOS_MAX;
+		iter->at_end = true;
+	}
+
+	return ret;
+}
+
+void bch2_btree_and_journal_iter_exit(struct btree_and_journal_iter *iter)
+{
+	bch2_journal_iter_exit(&iter->journal);
+}
+
+void __bch2_btree_and_journal_iter_init_node_iter(struct btree_and_journal_iter *iter,
+						  struct bch_fs *c,
+						  struct btree *b,
+						  struct btree_node_iter node_iter,
+						  struct bpos pos)
+{
+	memset(iter, 0, sizeof(*iter));
+
+	iter->b = b;
+	iter->node_iter = node_iter;
+	bch2_journal_iter_init(c, &iter->journal, b->c.btree_id, b->c.level, pos);
+	INIT_LIST_HEAD(&iter->journal.list);
+	iter->pos = b->data->min_key;
+	iter->at_end = false;
+}
+
+/*
+ * this version is used by btree_gc before filesystem has gone RW and
+ * multithreaded, so uses the journal_iters list:
+ */
+void bch2_btree_and_journal_iter_init_node_iter(struct btree_and_journal_iter *iter,
+						struct bch_fs *c,
+						struct btree *b)
+{
+	struct btree_node_iter node_iter;
+
+	bch2_btree_node_iter_init_from_start(&node_iter, b);
+	__bch2_btree_and_journal_iter_init_node_iter(iter, c, b, node_iter, b->data->min_key);
+	list_add(&iter->journal.list, &c->journal_iters);
+}
+
+/* sort and dedup all keys in the journal: */
+
+void bch2_journal_entries_free(struct bch_fs *c)
+{
+	struct journal_replay **i;
+	struct genradix_iter iter;
+
+	genradix_for_each(&c->journal_entries, iter, i)
+		if (*i)
+			kvpfree(*i, offsetof(struct journal_replay, j) +
+				vstruct_bytes(&(*i)->j));
+	genradix_free(&c->journal_entries);
+}
+
+/*
+ * When keys compare equal, oldest compares first:
+ */
+static int journal_sort_key_cmp(const void *_l, const void *_r)
+{
+	const struct journal_key *l = _l;
+	const struct journal_key *r = _r;
+
+	return  journal_key_cmp(l, r) ?:
+		cmp_int(l->journal_seq, r->journal_seq) ?:
+		cmp_int(l->journal_offset, r->journal_offset);
+}
+
+void bch2_journal_keys_free(struct journal_keys *keys)
+{
+	struct journal_key *i;
+
+	move_gap(keys->d, keys->nr, keys->size, keys->gap, keys->nr);
+	keys->gap = keys->nr;
+
+	for (i = keys->d; i < keys->d + keys->nr; i++)
+		if (i->allocated)
+			kfree(i->k);
+
+	kvfree(keys->d);
+	keys->d = NULL;
+	keys->nr = keys->gap = keys->size = 0;
+}
+
+static void __journal_keys_sort(struct journal_keys *keys)
+{
+	struct journal_key *src, *dst;
+
+	sort(keys->d, keys->nr, sizeof(keys->d[0]), journal_sort_key_cmp, NULL);
+
+	src = dst = keys->d;
+	while (src < keys->d + keys->nr) {
+		while (src + 1 < keys->d + keys->nr &&
+		       src[0].btree_id	== src[1].btree_id &&
+		       src[0].level	== src[1].level &&
+		       bpos_eq(src[0].k->k.p, src[1].k->k.p))
+			src++;
+
+		*dst++ = *src++;
+	}
+
+	keys->nr = dst - keys->d;
+}
+
+int bch2_journal_keys_sort(struct bch_fs *c)
+{
+	struct genradix_iter iter;
+	struct journal_replay *i, **_i;
+	struct jset_entry *entry;
+	struct bkey_i *k;
+	struct journal_keys *keys = &c->journal_keys;
+	size_t nr_keys = 0, nr_read = 0;
+
+	genradix_for_each(&c->journal_entries, iter, _i) {
+		i = *_i;
+
+		if (!i || i->ignore)
+			continue;
+
+		for_each_jset_key(k, entry, &i->j)
+			nr_keys++;
+	}
+
+	if (!nr_keys)
+		return 0;
+
+	keys->size = roundup_pow_of_two(nr_keys);
+
+	keys->d = kvmalloc_array(keys->size, sizeof(keys->d[0]), GFP_KERNEL);
+	if (!keys->d) {
+		bch_err(c, "Failed to allocate buffer for sorted journal keys (%zu keys); trying slowpath",
+			nr_keys);
+
+		do {
+			keys->size >>= 1;
+			keys->d = kvmalloc_array(keys->size, sizeof(keys->d[0]), GFP_KERNEL);
+		} while (!keys->d && keys->size > nr_keys / 8);
+
+		if (!keys->d) {
+			bch_err(c, "Failed to allocate %zu size buffer for sorted journal keys; exiting",
+				keys->size);
+			return -BCH_ERR_ENOMEM_journal_keys_sort;
+		}
+	}
+
+	genradix_for_each(&c->journal_entries, iter, _i) {
+		i = *_i;
+
+		if (!i || i->ignore)
+			continue;
+
+		cond_resched();
+
+		for_each_jset_key(k, entry, &i->j) {
+			if (keys->nr == keys->size) {
+				__journal_keys_sort(keys);
+
+				if (keys->nr > keys->size * 7 / 8) {
+					bch_err(c, "Too many journal keys for slowpath; have %zu compacted, buf size %zu, processed %zu/%zu",
+						keys->nr, keys->size, nr_read, nr_keys);
+					return -BCH_ERR_ENOMEM_journal_keys_sort;
+				}
+			}
+
+			keys->d[keys->nr++] = (struct journal_key) {
+				.btree_id	= entry->btree_id,
+				.level		= entry->level,
+				.k		= k,
+				.journal_seq	= le64_to_cpu(i->j.seq),
+				.journal_offset	= k->_data - i->j._data,
+			};
+
+			nr_read++;
+		}
+	}
+
+	__journal_keys_sort(keys);
+	keys->gap = keys->nr;
+
+	bch_verbose(c, "Journal keys: %zu read, %zu after sorting and compacting", nr_keys, keys->nr);
+	return 0;
+}

fs/bcachefs/btree_journal_iter.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_BTREE_JOURNAL_ITER_H
+#define _BCACHEFS_BTREE_JOURNAL_ITER_H
+
+struct journal_iter {
+	struct list_head	list;
+	enum btree_id		btree_id;
+	unsigned		level;
+	size_t			idx;
+	struct journal_keys	*keys;
+};
+
+/*
+ * Iterate over keys in the btree, with keys from the journal overlaid on top:
+ */
+
+struct btree_and_journal_iter {
+	struct btree		*b;
+	struct btree_node_iter	node_iter;
+	struct bkey		unpacked;
+
+	struct journal_iter	journal;
+	struct bpos		pos;
+	bool			at_end;
+};
+
+struct bkey_i *bch2_journal_keys_peek_upto(struct bch_fs *, enum btree_id,
+				unsigned, struct bpos, struct bpos, size_t *);
+struct bkey_i *bch2_journal_keys_peek_slot(struct bch_fs *, enum btree_id,
+					   unsigned, struct bpos);
+
+int bch2_journal_key_insert_take(struct bch_fs *, enum btree_id,
+				 unsigned, struct bkey_i *);
+int bch2_journal_key_insert(struct bch_fs *, enum btree_id,
+			    unsigned, struct bkey_i *);
+int bch2_journal_key_delete(struct bch_fs *, enum btree_id,
+			    unsigned, struct bpos);
+void bch2_journal_key_overwritten(struct bch_fs *, enum btree_id,
+				  unsigned, struct bpos);
+
+void bch2_btree_and_journal_iter_advance(struct btree_and_journal_iter *);
+struct bkey_s_c bch2_btree_and_journal_iter_peek(struct btree_and_journal_iter *);
+
+void bch2_btree_and_journal_iter_exit(struct btree_and_journal_iter *);
+void __bch2_btree_and_journal_iter_init_node_iter(struct btree_and_journal_iter *,
+				struct bch_fs *, struct btree *,
+				struct btree_node_iter, struct bpos);
+void bch2_btree_and_journal_iter_init_node_iter(struct btree_and_journal_iter *,
+						struct bch_fs *,
+						struct btree *);
+
+void bch2_journal_keys_free(struct journal_keys *);
+void bch2_journal_entries_free(struct bch_fs *);
+
+int bch2_journal_keys_sort(struct bch_fs *);
+
+#endif /* _BCACHEFS_BTREE_JOURNAL_ITER_H */

fs/bcachefs/btree_trans_commit.c

···
 #include "btree_gc.h"
 #include "btree_io.h"
 #include "btree_iter.h"
+#include "btree_journal_iter.h"
 #include "btree_key_cache.h"
 #include "btree_update_interior.h"
 #include "btree_write_buffer.h"
···
 #include "error.h"
 #include "journal.h"
 #include "journal_reclaim.h"
-#include "recovery.h"
 #include "replicas.h"
 #include "subvolume.h"
 

fs/bcachefs/btree_update.c

···
 #include "bcachefs.h"
 #include "btree_update.h"
 #include "btree_iter.h"
+#include "btree_journal_iter.h"
 #include "btree_locking.h"
 #include "buckets.h"
 #include "debug.h"
···
 #include "error.h"
 #include "extents.h"
 #include "keylist.h"
-#include "recovery.h"
 #include "subvolume.h"
 #include "trace.h"
 

fs/bcachefs/btree_update_interior.c

···
 #include "bkey_methods.h"
 #include "btree_cache.h"
 #include "btree_gc.h"
+#include "btree_journal_iter.h"
 #include "btree_update.h"
 #include "btree_update_interior.h"
 #include "btree_io.h"
···
 #include "journal.h"
 #include "journal_reclaim.h"
 #include "keylist.h"
-#include "recovery.h"
 #include "replicas.h"
 #include "super-io.h"
 #include "trace.h"

fs/bcachefs/recovery.c

···
 #include "bkey_buf.h"
 #include "alloc_background.h"
 #include "btree_gc.h"
+#include "btree_journal_iter.h"
 #include "btree_update.h"
 #include "btree_update_interior.h"
 #include "btree_io.h"
···
 	for (i = keys->d; i < keys->d + keys->nr; i++)
 		if (i->k->k.type == KEY_TYPE_btree_ptr_v2)
 			bkey_i_to_btree_ptr_v2(i->k)->v.mem_ptr = 0;
-}
-
-/* iterate over keys read from the journal: */
-
-static int __journal_key_cmp(enum btree_id	l_btree_id,
-			     unsigned		l_level,
-			     struct bpos	l_pos,
-			     const struct journal_key *r)
-{
-	return (cmp_int(l_btree_id,	r->btree_id) ?:
-		cmp_int(l_level,	r->level) ?:
-		bpos_cmp(l_pos,	r->k->k.p));
-}
-
-static int journal_key_cmp(const struct journal_key *l, const struct journal_key *r)
-{
-	return __journal_key_cmp(l->btree_id, l->level, l->k->k.p, r);
-}
-
-static inline size_t idx_to_pos(struct journal_keys *keys, size_t idx)
-{
-	size_t gap_size = keys->size - keys->nr;
-
-	if (idx >= keys->gap)
-		idx += gap_size;
-	return idx;
-}
-
-static inline struct journal_key *idx_to_key(struct journal_keys *keys, size_t idx)
-{
-	return keys->d + idx_to_pos(keys, idx);
-}
-
-static size_t __bch2_journal_key_search(struct journal_keys *keys,
-					enum btree_id id, unsigned level,
-					struct bpos pos)
-{
-	size_t l = 0, r = keys->nr, m;
-
-	while (l < r) {
-		m = l + ((r - l) >> 1);
-		if (__journal_key_cmp(id, level, pos, idx_to_key(keys, m)) > 0)
-			l = m + 1;
-		else
-			r = m;
-	}
-
-	BUG_ON(l < keys->nr &&
-	       __journal_key_cmp(id, level, pos, idx_to_key(keys, l)) > 0);
-
-	BUG_ON(l &&
-	       __journal_key_cmp(id, level, pos, idx_to_key(keys, l - 1)) <= 0);
-
-	return l;
-}
-
-static size_t bch2_journal_key_search(struct journal_keys *keys,
-				      enum btree_id id, unsigned level,
-				      struct bpos pos)
-{
-	return idx_to_pos(keys, __bch2_journal_key_search(keys, id, level, pos));
-}
-
-struct bkey_i *bch2_journal_keys_peek_upto(struct bch_fs *c, enum btree_id btree_id,
-					   unsigned level, struct bpos pos,
-					   struct bpos end_pos, size_t *idx)
-{
-	struct journal_keys *keys = &c->journal_keys;
-	unsigned iters = 0;
-	struct journal_key *k;
-search:
-	if (!*idx)
-		*idx = __bch2_journal_key_search(keys, btree_id, level, pos);
-
-	while ((k = *idx < keys->nr ? idx_to_key(keys, *idx) : NULL)) {
-		if (__journal_key_cmp(btree_id, level, end_pos, k) < 0)
-			return NULL;
-
-		if (__journal_key_cmp(btree_id, level, pos, k) <= 0 &&
-		    !k->overwritten)
-			return k->k;
-
-		(*idx)++;
-		iters++;
-		if (iters == 10) {
-			*idx = 0;
-			goto search;
-		}
-	}
-
-	return NULL;
-}
-
-struct bkey_i *bch2_journal_keys_peek_slot(struct bch_fs *c, enum btree_id btree_id,
-					   unsigned level, struct bpos pos)
-{
-	size_t idx = 0;
-
-	return bch2_journal_keys_peek_upto(c, btree_id, level, pos, pos, &idx);
-}
-
-static void journal_iters_fix(struct bch_fs *c)
-{
-	struct journal_keys *keys = &c->journal_keys;
-	/* The key we just inserted is immediately before the gap: */
-	size_t gap_end = keys->gap + (keys->size - keys->nr);
-	struct btree_and_journal_iter *iter;
-
-	/*
-	 * If an iterator points one after the key we just inserted, decrement
-	 * the iterator so it points at the key we just inserted - if the
-	 * decrement was unnecessary, bch2_btree_and_journal_iter_peek() will
-	 * handle that:
-	 */
-	list_for_each_entry(iter, &c->journal_iters, journal.list)
-		if (iter->journal.idx == gap_end)
-			iter->journal.idx = keys->gap - 1;
-}
-
-static void journal_iters_move_gap(struct bch_fs *c, size_t old_gap, size_t new_gap)
-{
-	struct journal_keys *keys = &c->journal_keys;
-	struct journal_iter *iter;
-	size_t gap_size = keys->size - keys->nr;
-
-	list_for_each_entry(iter, &c->journal_iters, list) {
-		if (iter->idx > old_gap)
-			iter->idx -= gap_size;
-		if (iter->idx >= new_gap)
-			iter->idx += gap_size;
-	}
-}
-
-int bch2_journal_key_insert_take(struct bch_fs *c, enum btree_id id,
-				 unsigned level, struct bkey_i *k)
-{
-	struct journal_key n = {
-		.btree_id	= id,
-		.level		= level,
-		.k		= k,
-		.allocated	= true,
-		/*
-		 * Ensure these keys are done last by journal replay, to unblock
-		 * journal reclaim:
-		 */
-		.journal_seq	= U32_MAX,
-	};
-	struct journal_keys *keys = &c->journal_keys;
-	size_t idx = bch2_journal_key_search(keys, id, level, k->k.p);
-
-	BUG_ON(test_bit(BCH_FS_RW, &c->flags));
-
-	if (idx < keys->size &&
-	    journal_key_cmp(&n, &keys->d[idx]) == 0) {
-		if (keys->d[idx].allocated)
-			kfree(keys->d[idx].k);
-		keys->d[idx] = n;
-		return 0;
-	}
-
-	if (idx > keys->gap)
-		idx -= keys->size - keys->nr;
-
-	if (keys->nr == keys->size) {
-		struct journal_keys new_keys = {
-			.nr			= keys->nr,
-			.size			= max_t(size_t, keys->size, 8) * 2,
-		};
-
-		new_keys.d = kvmalloc_array(new_keys.size, sizeof(new_keys.d[0]), GFP_KERNEL);
-		if (!new_keys.d) {
-			bch_err(c, "%s: error allocating new key array (size %zu)",
-				__func__, new_keys.size);
-			return -BCH_ERR_ENOMEM_journal_key_insert;
-		}
-
-		/* Since @keys was full, there was no gap: */
-		memcpy(new_keys.d, keys->d, sizeof(keys->d[0]) * keys->nr);
-		kvfree(keys->d);
-		*keys = new_keys;
-
-		/* And now the gap is at the end: */
-		keys->gap = keys->nr;
-	}
-
-	journal_iters_move_gap(c, keys->gap, idx);
-
-	move_gap(keys->d, keys->nr, keys->size, keys->gap, idx);
-	keys->gap = idx;
-
-	keys->nr++;
-	keys->d[keys->gap++] = n;
-
-	journal_iters_fix(c);
-
-	return 0;
-}
-
-/*
- * Can only be used from the recovery thread while we're still RO - can't be
- * used once we've got RW, as journal_keys is at that point used by multiple
- * threads:
- */
-int bch2_journal_key_insert(struct bch_fs *c, enum btree_id id,
-			    unsigned level, struct bkey_i *k)
-{
-	struct bkey_i *n;
-	int ret;
-
-	n = kmalloc(bkey_bytes(&k->k), GFP_KERNEL);
-	if (!n)
-		return -BCH_ERR_ENOMEM_journal_key_insert;
-
-	bkey_copy(n, k);
-	ret = bch2_journal_key_insert_take(c, id, level, n);
-	if (ret)
-		kfree(n);
-	return ret;
-}
-
-int bch2_journal_key_delete(struct bch_fs *c, enum btree_id id,
-			    unsigned level, struct bpos pos)
-{
-	struct bkey_i whiteout;
-
-	bkey_init(&whiteout.k);
-	whiteout.k.p = pos;
-
-	return bch2_journal_key_insert(c, id, level, &whiteout);
-}
-
-void bch2_journal_key_overwritten(struct bch_fs *c, enum btree_id btree,
-				  unsigned level, struct bpos pos)
-{
-	struct journal_keys *keys = &c->journal_keys;
-	size_t idx = bch2_journal_key_search(keys, btree, level, pos);
-
-	if (idx < keys->size &&
-	    keys->d[idx].btree_id	== btree &&
-	    keys->d[idx].level		== level &&
-	    bpos_eq(keys->d[idx].k->k.p, pos))
-		keys->d[idx].overwritten = true;
-}
-
-static void bch2_journal_iter_advance(struct journal_iter *iter)
-{
-	if (iter->idx < iter->keys->size) {
-		iter->idx++;
-		if (iter->idx == iter->keys->gap)
-			iter->idx += iter->keys->size - iter->keys->nr;
-	}
-}
-
-static struct bkey_s_c bch2_journal_iter_peek(struct journal_iter *iter)
-{
-	struct journal_key *k = iter->keys->d + iter->idx;
-
-	while (k < iter->keys->d + iter->keys->size &&
-	       k->btree_id	== iter->btree_id &&
-	       k->level		== iter->level) {
-		if (!k->overwritten)
-			return bkey_i_to_s_c(k->k);
-
-		bch2_journal_iter_advance(iter);
-		k = iter->keys->d + iter->idx;
-	}
-
-	return bkey_s_c_null;
-}
-
-static void bch2_journal_iter_exit(struct journal_iter *iter)
-{
-	list_del(&iter->list);
-}
-
-static void bch2_journal_iter_init(struct bch_fs *c,
-				   struct journal_iter *iter,
-				   enum btree_id id, unsigned level,
-				   struct bpos pos)
-{
-	iter->btree_id	= id;
-	iter->level	= level;
-	iter->keys	= &c->journal_keys;
-	iter->idx	= bch2_journal_key_search(&c->journal_keys, id, level, pos);
-}
-
-static struct bkey_s_c bch2_journal_iter_peek_btree(struct btree_and_journal_iter *iter)
-{
-	return bch2_btree_node_iter_peek_unpack(&iter->node_iter,
-						iter->b, &iter->unpacked);
-}
-
-static void bch2_journal_iter_advance_btree(struct btree_and_journal_iter *iter)
-{
-	bch2_btree_node_iter_advance(&iter->node_iter, iter->b);
-}
-
-void bch2_btree_and_journal_iter_advance(struct btree_and_journal_iter *iter)
-{
-	if (bpos_eq(iter->pos, SPOS_MAX))
-		iter->at_end = true;
-	else
-		iter->pos = bpos_successor(iter->pos);
-}
-
-struct bkey_s_c bch2_btree_and_journal_iter_peek(struct btree_and_journal_iter *iter)
-{
-	struct bkey_s_c btree_k, journal_k, ret;
-again:
-	if (iter->at_end)
-		return bkey_s_c_null;
-
-	while ((btree_k = bch2_journal_iter_peek_btree(iter)).k &&
-	       bpos_lt(btree_k.k->p, iter->pos))
-		bch2_journal_iter_advance_btree(iter);
-
-	while ((journal_k = bch2_journal_iter_peek(&iter->journal)).k &&
-	       bpos_lt(journal_k.k->p, iter->pos))
-		bch2_journal_iter_advance(&iter->journal);
-
-	ret = journal_k.k &&
-		(!btree_k.k || bpos_le(journal_k.k->p, btree_k.k->p))
-		? journal_k
-		: btree_k;
-
-	if (ret.k && iter->b && bpos_gt(ret.k->p, iter->b->data->max_key))
-		ret = bkey_s_c_null;
-
-	if (ret.k) {
-		iter->pos = ret.k->p;
-		if (bkey_deleted(ret.k)) {
-			bch2_btree_and_journal_iter_advance(iter);
-			goto again;
-		}
-	} else {
-		iter->pos = SPOS_MAX;
-		iter->at_end = true;
-	}
-
-	return ret;
-}
-
-void bch2_btree_and_journal_iter_exit(struct btree_and_journal_iter *iter)
-{
-	bch2_journal_iter_exit(&iter->journal);
-}
-
-void __bch2_btree_and_journal_iter_init_node_iter(struct btree_and_journal_iter *iter,
-						  struct bch_fs *c,
-						  struct btree *b,
-						  struct btree_node_iter node_iter,
-						  struct bpos pos)
-{
-	memset(iter, 0, sizeof(*iter));
-
-	iter->b = b;
-	iter->node_iter = node_iter;
-	bch2_journal_iter_init(c, &iter->journal, b->c.btree_id, b->c.level, pos);
-	INIT_LIST_HEAD(&iter->journal.list);
-	iter->pos = b->data->min_key;
-	iter->at_end = false;
-}
-
-/*
- * this version is used by btree_gc before filesystem has gone RW and
- * multithreaded, so uses the journal_iters list:
- */
-void bch2_btree_and_journal_iter_init_node_iter(struct btree_and_journal_iter *iter,
-						struct bch_fs *c,
-						struct btree *b)
-{
-	struct btree_node_iter node_iter;
-
-	bch2_btree_node_iter_init_from_start(&node_iter, b);
-	__bch2_btree_and_journal_iter_init_node_iter(iter, c, b, node_iter, b->data->min_key);
-	list_add(&iter->journal.list, &c->journal_iters);
-}
-
-/* sort and dedup all keys in the journal: */
-
-void bch2_journal_entries_free(struct bch_fs *c)
-{
-	struct journal_replay **i;
-	struct genradix_iter iter;
-
-	genradix_for_each(&c->journal_entries, iter, i)
-		if (*i)
-			kvpfree(*i, offsetof(struct journal_replay, j) +
-				vstruct_bytes(&(*i)->j));
-	genradix_free(&c->journal_entries);
-}
-
-/*
- * When keys compare equal, oldest compares first:
- */
-static int journal_sort_key_cmp(const void *_l, const void *_r)
-{
-	const struct journal_key *l = _l;
-	const struct journal_key *r = _r;
-
-	return  journal_key_cmp(l, r) ?:
-		cmp_int(l->journal_seq, r->journal_seq) ?:
-		cmp_int(l->journal_offset, r->journal_offset);
-}
-
-void bch2_journal_keys_free(struct journal_keys *keys)
-{
-	struct journal_key *i;
-
-	move_gap(keys->d, keys->nr, keys->size, keys->gap, keys->nr);
-	keys->gap = keys->nr;
-
-	for (i = keys->d; i < keys->d + keys->nr; i++)
-		if (i->allocated)
-			kfree(i->k);
-
-	kvfree(keys->d);
-	keys->d = NULL;
-	keys->nr = keys->gap = keys->size = 0;
-}
-
-static void __journal_keys_sort(struct journal_keys *keys)
-{
-	struct journal_key *src, *dst;
-
-	sort(keys->d, keys->nr, sizeof(keys->d[0]), journal_sort_key_cmp, NULL);
-
-	src = dst = keys->d;
-	while (src < keys->d + keys->nr) {
-		while (src + 1 < keys->d + keys->nr &&
-		       src[0].btree_id	== src[1].btree_id &&
-		       src[0].level	== src[1].level &&
-		       bpos_eq(src[0].k->k.p, src[1].k->k.p))
-			src++;
-
-		*dst++ = *src++;
-	}
-
-	keys->nr = dst - keys->d;
-}
-
-static int journal_keys_sort(struct bch_fs *c)
-{
-	struct genradix_iter iter;
-	struct journal_replay *i, **_i;
-	struct jset_entry *entry;
-	struct bkey_i *k;
-	struct journal_keys *keys = &c->journal_keys;
-	size_t nr_keys = 0, nr_read = 0;
-
-	genradix_for_each(&c->journal_entries, iter, _i) {
-		i = *_i;
-
-		if (!i || i->ignore)
-			continue;
-
-		for_each_jset_key(k, entry, &i->j)
-			nr_keys++;
-	}
-
-	if (!nr_keys)
-		return 0;
-
-	keys->size = roundup_pow_of_two(nr_keys);
-
-	keys->d = kvmalloc_array(keys->size, sizeof(keys->d[0]), GFP_KERNEL);
-	if (!keys->d) {
-		bch_err(c, "Failed to allocate buffer for sorted journal keys (%zu keys); trying slowpath",
-			nr_keys);
-
-		do {
-			keys->size >>= 1;
-			keys->d = kvmalloc_array(keys->size, sizeof(keys->d[0]), GFP_KERNEL);
-		} while (!keys->d && keys->size > nr_keys / 8);
-
-		if (!keys->d) {
-			bch_err(c, "Failed to allocate %zu size buffer for sorted journal keys; exiting",
-				keys->size);
-			return -BCH_ERR_ENOMEM_journal_keys_sort;
-		}
-	}
-
-	genradix_for_each(&c->journal_entries, iter, _i) {
-		i = *_i;
-
-		if (!i || i->ignore)
-			continue;
-
-		cond_resched();
-
-		for_each_jset_key(k, entry, &i->j) {
-			if (keys->nr == keys->size) {
-				__journal_keys_sort(keys);
-
-				if (keys->nr > keys->size * 7 / 8) {
-					bch_err(c, "Too many journal keys for slowpath; have %zu compacted, buf size %zu, processed %zu/%zu",
-						keys->nr, keys->size, nr_read, nr_keys);
-					return -BCH_ERR_ENOMEM_journal_keys_sort;
-				}
-			}
-
-			keys->d[keys->nr++] = (struct journal_key) {
-				.btree_id	= entry->btree_id,
-				.level		= entry->level,
-				.k		= k,
-				.journal_seq	= le64_to_cpu(i->j.seq),
-				.journal_offset	= k->_data - i->j._data,
-			};
-
-			nr_read++;
-		}
-	}
-
-	__journal_keys_sort(keys);
-	keys->gap = keys->nr;
-
-	bch_verbose(c, "Journal keys: %zu read, %zu after sorting and compacting", nr_keys, keys->nr);
-	return 0;
 }
 
 /* journal replay: */
···
 				}
 		}
 
-		ret = journal_keys_sort(c);
+		ret = bch2_journal_keys_sort(c);
 		if (ret)
 			goto err;
 

fs/bcachefs/recovery.h

···
 #ifndef _BCACHEFS_RECOVERY_H
 #define _BCACHEFS_RECOVERY_H
 
-struct journal_iter {
-	struct list_head	list;
-	enum btree_id		btree_id;
-	unsigned		level;
-	size_t			idx;
-	struct journal_keys	*keys;
-};
-
-/*
- * Iterate over keys in the btree, with keys from the journal overlaid on top:
- */
-
-struct btree_and_journal_iter {
-	struct btree		*b;
-	struct btree_node_iter	node_iter;
-	struct bkey		unpacked;
-
-	struct journal_iter	journal;
-	struct bpos		pos;
-	bool			at_end;
-};
-
-struct bkey_i *bch2_journal_keys_peek_upto(struct bch_fs *, enum btree_id,
-				unsigned, struct bpos, struct bpos, size_t *);
-struct bkey_i *bch2_journal_keys_peek_slot(struct bch_fs *, enum btree_id,
-					   unsigned, struct bpos);
-
-int bch2_journal_key_insert_take(struct bch_fs *, enum btree_id,
-				 unsigned, struct bkey_i *);
-int bch2_journal_key_insert(struct bch_fs *, enum btree_id,
-			    unsigned, struct bkey_i *);
-int bch2_journal_key_delete(struct bch_fs *, enum btree_id,
-			    unsigned, struct bpos);
-void bch2_journal_key_overwritten(struct bch_fs *, enum btree_id,
-				  unsigned, struct bpos);
-
-void bch2_btree_and_journal_iter_advance(struct btree_and_journal_iter *);
-struct bkey_s_c bch2_btree_and_journal_iter_peek(struct btree_and_journal_iter *);
-
-void bch2_btree_and_journal_iter_exit(struct btree_and_journal_iter *);
-void __bch2_btree_and_journal_iter_init_node_iter(struct btree_and_journal_iter *,
-				struct bch_fs *, struct btree *,
-				struct btree_node_iter, struct bpos);
-void bch2_btree_and_journal_iter_init_node_iter(struct btree_and_journal_iter *,
-						struct bch_fs *,
-						struct btree *);
-
-void bch2_journal_keys_free(struct journal_keys *);
-void bch2_journal_entries_free(struct bch_fs *);
-
 extern const char * const bch2_recovery_passes[];
 
 /*
···
 int bch2_fs_initialize(struct bch_fs *);
 
 #endif /* _BCACHEFS_RECOVERY_H */
-

fs/bcachefs/super.c

···
 #include "bkey_sort.h"
 #include "btree_cache.h"
 #include "btree_gc.h"
+#include "btree_journal_iter.h"
 #include "btree_key_cache.h"
 #include "btree_update_interior.h"
 #include "btree_io.h"