1 files changed, 611 insertions, 0 deletions

diff --git a/fs/bcachefs/btree_node_scan.c b/fs/bcachefs/btree_node_scan.c
new file mode 100644
index 000000000000..42c9eb2c786e
--- /dev/null
+++ b/fs/bcachefs/btree_node_scan.c
@@ -0,0 +1,611 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "btree_cache.h"
+#include "btree_io.h"
+#include "btree_journal_iter.h"
+#include "btree_node_scan.h"
+#include "btree_update_interior.h"
+#include "buckets.h"
+#include "error.h"
+#include "journal_io.h"
+#include "recovery_passes.h"
+
+#include <linux/kthread.h>
+#include <linux/min_heap.h>
+#include <linux/sched/sysctl.h>
+#include <linux/sort.h>
+
+struct find_btree_nodes_worker {
+	struct closure		*cl;
+	struct find_btree_nodes	*f;
+	struct bch_dev		*ca;
+};
+
+static void found_btree_node_to_text(struct printbuf *out, struct bch_fs *c, const struct found_btree_node *n)
+{
+	bch2_btree_id_level_to_text(out, n->btree_id, n->level);
+	prt_printf(out, " seq=%u journal_seq=%llu cookie=%llx ",
+		   n->seq, n->journal_seq, n->cookie);
+	bch2_bpos_to_text(out, n->min_key);
+	prt_str(out, "-");
+	bch2_bpos_to_text(out, n->max_key);
+
+	if (n->range_updated)
+		prt_str(out, " range updated");
+
+	for (unsigned i = 0; i < n->nr_ptrs; i++) {
+		prt_char(out, ' ');
+		bch2_extent_ptr_to_text(out, c, n->ptrs + i);
+	}
+}
+
+static void found_btree_nodes_to_text(struct printbuf *out, struct bch_fs *c, found_btree_nodes nodes)
+{
+	printbuf_indent_add(out, 2);
+	darray_for_each(nodes, i) {
+		found_btree_node_to_text(out, c, i);
+		prt_newline(out);
+	}
+	printbuf_indent_sub(out, 2);
+}
+
+static void found_btree_node_to_key(struct bkey_i *k, const struct found_btree_node *f)
+{
+	struct bkey_i_btree_ptr_v2 *bp = bkey_btree_ptr_v2_init(k);
+
+	set_bkey_val_u64s(&bp->k, sizeof(struct bch_btree_ptr_v2) / sizeof(u64) + f->nr_ptrs);
+	bp->k.p			= f->max_key;
+	bp->v.seq		= cpu_to_le64(f->cookie);
+	bp->v.sectors_written	= 0;
+	bp->v.flags		= 0;
+	bp->v.sectors_written	= cpu_to_le16(f->sectors_written);
+	bp->v.min_key		= f->min_key;
+	SET_BTREE_PTR_RANGE_UPDATED(&bp->v, f->range_updated);
+	memcpy(bp->v.start, f->ptrs, sizeof(struct bch_extent_ptr) * f->nr_ptrs);
+}
+
+static inline u64 bkey_journal_seq(struct bkey_s_c k)
+{
+	switch (k.k->type) {
+	case KEY_TYPE_inode_v3:
+		return le64_to_cpu(bkey_s_c_to_inode_v3(k).v->bi_journal_seq);
+	default:
+		return 0;
+	}
+}
+
+static int found_btree_node_cmp_cookie(const void *_l, const void *_r)
+{
+	const struct found_btree_node *l = _l;
+	const struct found_btree_node *r = _r;
+
+	return  cmp_int(l->btree_id,	r->btree_id) ?:
+		cmp_int(l->level,	r->level) ?:
+		cmp_int(l->cookie,	r->cookie);
+}
+
+/*
+ * Given two found btree nodes, if their sequence numbers are equal, take the
+ * one that's readable:
+ */
+static int found_btree_node_cmp_time(const struct found_btree_node *l,
+				     const struct found_btree_node *r)
+{
+	return  cmp_int(l->seq, r->seq) ?:
+		cmp_int(l->journal_seq, r->journal_seq);
+}
+
+static int found_btree_node_cmp_pos(const void *_l, const void *_r)
+{
+	const struct found_btree_node *l = _l;
+	const struct found_btree_node *r = _r;
+
+	return  cmp_int(l->btree_id,	r->btree_id) ?:
+	       -cmp_int(l->level,	r->level) ?:
+		bpos_cmp(l->min_key,	r->min_key) ?:
+	       -found_btree_node_cmp_time(l, r);
+}
+
+static inline bool found_btree_node_cmp_pos_less(const void *l, const void *r, void *arg)
+{
+	return found_btree_node_cmp_pos(l, r) < 0;
+}
+
+static inline void found_btree_node_swap(void *_l, void *_r, void *arg)
+{
+	struct found_btree_node *l = _l;
+	struct found_btree_node *r = _r;
+
+	swap(*l, *r);
+}
+
+static const struct min_heap_callbacks found_btree_node_heap_cbs = {
+	.less = found_btree_node_cmp_pos_less,
+	.swp = found_btree_node_swap,
+};
+
+static void try_read_btree_node(struct find_btree_nodes *f, struct bch_dev *ca,
+				struct btree *b, struct bio *bio, u64 offset)
+{
+	struct bch_fs *c = container_of(f, struct bch_fs, found_btree_nodes);
+	struct btree_node *bn = b->data;
+
+	bio_reset(bio, ca->disk_sb.bdev, REQ_OP_READ);
+	bio->bi_iter.bi_sector	= offset;
+	bch2_bio_map(bio, b->data, c->opts.block_size);
+
+	u64 submit_time = local_clock();
+	submit_bio_wait(bio);
+	bch2_account_io_completion(ca, BCH_MEMBER_ERROR_read, submit_time, !bio->bi_status);
+
+	if (bio->bi_status) {
+		bch_err_dev_ratelimited(ca,
+				"IO error in try_read_btree_node() at %llu: %s",
+				offset, bch2_blk_status_to_str(bio->bi_status));
+		return;
+	}
+
+	if (le64_to_cpu(bn->magic) != bset_magic(c))
+		return;
+
+	if (bch2_csum_type_is_encryption(BSET_CSUM_TYPE(&bn->keys))) {
+		if (!c->chacha20_key_set)
+			return;
+
+		struct nonce nonce = btree_nonce(&bn->keys, 0);
+		unsigned bytes = (void *) &bn->keys - (void *) &bn->flags;
+
+		bch2_encrypt(c, BSET_CSUM_TYPE(&bn->keys), nonce, &bn->flags, bytes);
+	}
+
+	if (btree_id_is_alloc(BTREE_NODE_ID(bn)))
+		return;
+
+	if (BTREE_NODE_LEVEL(bn) >= BTREE_MAX_DEPTH)
+		return;
+
+	if (BTREE_NODE_ID(bn) >= BTREE_ID_NR_MAX)
+		return;
+
+	bio_reset(bio, ca->disk_sb.bdev, REQ_OP_READ);
+	bio->bi_iter.bi_sector	= offset;
+	bch2_bio_map(bio, b->data, c->opts.btree_node_size);
+
+	submit_time = local_clock();
+	submit_bio_wait(bio);
+	bch2_account_io_completion(ca, BCH_MEMBER_ERROR_read, submit_time, !bio->bi_status);
+
+	rcu_read_lock();
+	struct found_btree_node n = {
+		.btree_id	= BTREE_NODE_ID(bn),
+		.level		= BTREE_NODE_LEVEL(bn),
+		.seq		= BTREE_NODE_SEQ(bn),
+		.cookie		= le64_to_cpu(bn->keys.seq),
+		.min_key	= bn->min_key,
+		.max_key	= bn->max_key,
+		.nr_ptrs	= 1,
+		.ptrs[0].type	= 1 << BCH_EXTENT_ENTRY_ptr,
+		.ptrs[0].offset	= offset,
+		.ptrs[0].dev	= ca->dev_idx,
+		.ptrs[0].gen	= bucket_gen_get(ca, sector_to_bucket(ca, offset)),
+	};
+	rcu_read_unlock();
+
+	found_btree_node_to_key(&b->key, &n);
+
+	CLASS(printbuf, buf)();
+	if (!bch2_btree_node_read_done(c, ca, b, NULL, &buf)) {
+		/* read_done will swap out b->data for another buffer */
+		bn = b->data;
+		/*
+		 * Grab journal_seq here because we want the max journal_seq of
+		 * any bset; read_done sorts down to a single set and picks the
+		 * max journal_seq
+		 */
+		n.journal_seq		= le64_to_cpu(bn->keys.journal_seq),
+		n.sectors_written	= b->written;
+
+		mutex_lock(&f->lock);
+		if (BSET_BIG_ENDIAN(&bn->keys) != CPU_BIG_ENDIAN) {
+			bch_err(c, "try_read_btree_node() can't handle endian conversion");
+			f->ret = -EINVAL;
+			goto unlock;
+		}
+
+		if (darray_push(&f->nodes, n))
+			f->ret = -ENOMEM;
+unlock:
+		mutex_unlock(&f->lock);
+	}
+}
+
+static int read_btree_nodes_worker(void *p)
+{
+	struct find_btree_nodes_worker *w = p;
+	struct bch_fs *c = container_of(w->f, struct bch_fs, found_btree_nodes);
+	struct bch_dev *ca = w->ca;
+	unsigned long last_print = jiffies;
+	struct btree *b = NULL;
+	struct bio *bio = NULL;
+
+	b = __bch2_btree_node_mem_alloc(c);
+	if (!b) {
+		bch_err(c, "read_btree_nodes_worker: error allocating buf");
+		w->f->ret = -ENOMEM;
+		goto err;
+	}
+
+	bio = bio_alloc(NULL, buf_pages(b->data, c->opts.btree_node_size), 0, GFP_KERNEL);
+	if (!bio) {
+		bch_err(c, "read_btree_nodes_worker: error allocating bio");
+		w->f->ret = -ENOMEM;
+		goto err;
+	}
+
+	for (u64 bucket = ca->mi.first_bucket; bucket < ca->mi.nbuckets; bucket++)
+		for (unsigned bucket_offset = 0;
+		     bucket_offset + btree_sectors(c) <= ca->mi.bucket_size;
+		     bucket_offset += btree_sectors(c)) {
+			if (time_after(jiffies, last_print + HZ * 30)) {
+				u64 cur_sector = bucket * ca->mi.bucket_size + bucket_offset;
+				u64 end_sector = ca->mi.nbuckets * ca->mi.bucket_size;
+
+				bch_info(ca, "%s: %2u%% done", __func__,
+					 (unsigned) div64_u64(cur_sector * 100, end_sector));
+				last_print = jiffies;
+			}
+
+			u64 sector = bucket * ca->mi.bucket_size + bucket_offset;
+
+			if (c->sb.version_upgrade_complete >= bcachefs_metadata_version_mi_btree_bitmap &&
+			    !bch2_dev_btree_bitmap_marked_sectors(ca, sector, btree_sectors(c)))
+				continue;
+
+			try_read_btree_node(w->f, ca, b, bio, sector);
+		}
+err:
+	if (b)
+		__btree_node_data_free(b);
+	kfree(b);
+	bio_put(bio);
+	enumerated_ref_put(&ca->io_ref[READ], BCH_DEV_READ_REF_btree_node_scan);
+	closure_put(w->cl);
+	kfree(w);
+	return 0;
+}
+
+static int read_btree_nodes(struct find_btree_nodes *f)
+{
+	struct bch_fs *c = container_of(f, struct bch_fs, found_btree_nodes);
+	struct closure cl;
+	int ret = 0;
+
+	closure_init_stack(&cl);
+
+	for_each_online_member(c, ca, BCH_DEV_READ_REF_btree_node_scan) {
+		if (!(ca->mi.data_allowed & BIT(BCH_DATA_btree)))
+			continue;
+
+		struct find_btree_nodes_worker *w = kmalloc(sizeof(*w), GFP_KERNEL);
+		if (!w) {
+			enumerated_ref_put(&ca->io_ref[READ], BCH_DEV_READ_REF_btree_node_scan);
+			ret = -ENOMEM;
+			goto err;
+		}
+
+		w->cl		= &cl;
+		w->f		= f;
+		w->ca		= ca;
+
+		struct task_struct *t = kthread_create(read_btree_nodes_worker, w, "read_btree_nodes/%s", ca->name);
+		ret = PTR_ERR_OR_ZERO(t);
+		if (ret) {
+			enumerated_ref_put(&ca->io_ref[READ], BCH_DEV_READ_REF_btree_node_scan);
+			kfree(w);
+			bch_err_msg(c, ret, "starting kthread");
+			break;
+		}
+
+		closure_get(&cl);
+		enumerated_ref_get(&ca->io_ref[READ], BCH_DEV_READ_REF_btree_node_scan);
+		wake_up_process(t);
+	}
+err:
+	while (closure_sync_timeout(&cl, sysctl_hung_task_timeout_secs * HZ / 2))
+		;
+	return f->ret ?: ret;
+}
+
+static bool nodes_overlap(const struct found_btree_node *l,
+			  const struct found_btree_node *r)
+{
+	return (l->btree_id	== r->btree_id &&
+		l->level	== r->level &&
+		bpos_gt(l->max_key, r->min_key));
+}
+
+static int handle_overwrites(struct bch_fs *c,
+			     struct found_btree_node *l,
+			     found_btree_nodes *nodes_heap)
+{
+	struct found_btree_node *r;
+
+	while ((r = min_heap_peek(nodes_heap)) &&
+	       nodes_overlap(l, r)) {
+		int cmp = found_btree_node_cmp_time(l, r);
+
+		if (cmp > 0) {
+			if (bpos_cmp(l->max_key, r->max_key) >= 0)
+				min_heap_pop(nodes_heap, &found_btree_node_heap_cbs, NULL);
+			else {
+				r->range_updated = true;
+				r->min_key = bpos_successor(l->max_key);
+				r->range_updated = true;
+				min_heap_sift_down(nodes_heap, 0, &found_btree_node_heap_cbs, NULL);
+			}
+		} else if (cmp < 0) {
+			BUG_ON(bpos_eq(l->min_key, r->min_key));
+
+			l->max_key = bpos_predecessor(r->min_key);
+			l->range_updated = true;
+		} else if (r->level) {
+			min_heap_pop(nodes_heap, &found_btree_node_heap_cbs, NULL);
+		} else {
+			if (bpos_cmp(l->max_key, r->max_key) >= 0)
+				min_heap_pop(nodes_heap, &found_btree_node_heap_cbs, NULL);
+			else {
+				r->range_updated = true;
+				r->min_key = bpos_successor(l->max_key);
+				r->range_updated = true;
+				min_heap_sift_down(nodes_heap, 0, &found_btree_node_heap_cbs, NULL);
+			}
+		}
+
+		cond_resched();
+	}
+
+	return 0;
+}
+
+int bch2_scan_for_btree_nodes(struct bch_fs *c)
+{
+	struct find_btree_nodes *f = &c->found_btree_nodes;
+	struct printbuf buf = PRINTBUF;
+	found_btree_nodes nodes_heap = {};
+	size_t dst;
+	int ret = 0;
+
+	if (f->nodes.nr)
+		return 0;
+
+	mutex_init(&f->lock);
+
+	ret = read_btree_nodes(f);
+	if (ret)
+		return ret;
+
+	if (!f->nodes.nr) {
+		bch_err(c, "%s: no btree nodes found", __func__);
+		ret = -EINVAL;
+		goto err;
+	}
+
+	if (0 && c->opts.verbose) {
+		printbuf_reset(&buf);
+		prt_printf(&buf, "%s: nodes found:\n", __func__);
+		found_btree_nodes_to_text(&buf, c, f->nodes);
+		bch2_print_str(c, KERN_INFO, buf.buf);
+	}
+
+	sort_nonatomic(f->nodes.data, f->nodes.nr, sizeof(f->nodes.data[0]), found_btree_node_cmp_cookie, NULL);
+
+	dst = 0;
+	darray_for_each(f->nodes, i) {
+		struct found_btree_node *prev = dst ? f->nodes.data + dst - 1 : NULL;
+
+		if (prev &&
+		    prev->cookie == i->cookie) {
+			if (prev->nr_ptrs == ARRAY_SIZE(prev->ptrs)) {
+				bch_err(c, "%s: found too many replicas for btree node", __func__);
+				ret = -EINVAL;
+				goto err;
+			}
+			prev->ptrs[prev->nr_ptrs++] = i->ptrs[0];
+		} else {
+			f->nodes.data[dst++] = *i;
+		}
+	}
+	f->nodes.nr = dst;
+
+	sort_nonatomic(f->nodes.data, f->nodes.nr, sizeof(f->nodes.data[0]), found_btree_node_cmp_pos, NULL);
+
+	if (0 && c->opts.verbose) {
+		printbuf_reset(&buf);
+		prt_printf(&buf, "%s: nodes after merging replicas:\n", __func__);
+		found_btree_nodes_to_text(&buf, c, f->nodes);
+		bch2_print_str(c, KERN_INFO, buf.buf);
+	}
+
+	swap(nodes_heap, f->nodes);
+
+	{
+		/* darray must have same layout as a heap */
+		min_heap_char real_heap;
+		BUILD_BUG_ON(sizeof(nodes_heap.nr)	!= sizeof(real_heap.nr));
+		BUILD_BUG_ON(sizeof(nodes_heap.size)	!= sizeof(real_heap.size));
+		BUILD_BUG_ON(offsetof(found_btree_nodes, nr)	!= offsetof(min_heap_char, nr));
+		BUILD_BUG_ON(offsetof(found_btree_nodes, size)	!= offsetof(min_heap_char, size));
+	}
+
+	min_heapify_all(&nodes_heap, &found_btree_node_heap_cbs, NULL);
+
+	if (nodes_heap.nr) {
+		ret = darray_push(&f->nodes, *min_heap_peek(&nodes_heap));
+		if (ret)
+			goto err;
+
+		min_heap_pop(&nodes_heap, &found_btree_node_heap_cbs, NULL);
+	}
+
+	while (true) {
+		ret = handle_overwrites(c, &darray_last(f->nodes), &nodes_heap);
+		if (ret)
+			goto err;
+
+		if (!nodes_heap.nr)
+			break;
+
+		ret = darray_push(&f->nodes, *min_heap_peek(&nodes_heap));
+		if (ret)
+			goto err;
+
+		min_heap_pop(&nodes_heap, &found_btree_node_heap_cbs, NULL);
+	}
+
+	for (struct found_btree_node *n = f->nodes.data; n < &darray_last(f->nodes); n++)
+		BUG_ON(nodes_overlap(n, n + 1));
+
+	if (0 && c->opts.verbose) {
+		printbuf_reset(&buf);
+		prt_printf(&buf, "%s: nodes found after overwrites:\n", __func__);
+		found_btree_nodes_to_text(&buf, c, f->nodes);
+		bch2_print_str(c, KERN_INFO, buf.buf);
+	} else {
+		bch_info(c, "btree node scan found %zu nodes after overwrites", f->nodes.nr);
+	}
+
+	eytzinger0_sort(f->nodes.data, f->nodes.nr, sizeof(f->nodes.data[0]), found_btree_node_cmp_pos, NULL);
+err:
+	darray_exit(&nodes_heap);
+	printbuf_exit(&buf);
+	return ret;
+}
+
+static int found_btree_node_range_start_cmp(const void *_l, const void *_r)
+{
+	const struct found_btree_node *l = _l;
+	const struct found_btree_node *r = _r;
+
+	return  cmp_int(l->btree_id,	r->btree_id) ?:
+	       -cmp_int(l->level,	r->level) ?:
+		bpos_cmp(l->max_key,	r->min_key);
+}
+
+#define for_each_found_btree_node_in_range(_f, _search, _idx)				\
+	for (size_t _idx = eytzinger0_find_gt((_f)->nodes.data, (_f)->nodes.nr,		\
+					sizeof((_f)->nodes.data[0]),			\
+					found_btree_node_range_start_cmp, &search);	\
+	     _idx < (_f)->nodes.nr &&							\
+	     (_f)->nodes.data[_idx].btree_id == _search.btree_id &&			\
+	     (_f)->nodes.data[_idx].level == _search.level &&				\
+	     bpos_lt((_f)->nodes.data[_idx].min_key, _search.max_key);			\
+	     _idx = eytzinger0_next(_idx, (_f)->nodes.nr))
+
+bool bch2_btree_node_is_stale(struct bch_fs *c, struct btree *b)
+{
+	struct find_btree_nodes *f = &c->found_btree_nodes;
+
+	struct found_btree_node search = {
+		.btree_id	= b->c.btree_id,
+		.level		= b->c.level,
+		.min_key	= b->data->min_key,
+		.max_key	= b->key.k.p,
+	};
+
+	for_each_found_btree_node_in_range(f, search, idx)
+		if (f->nodes.data[idx].seq > BTREE_NODE_SEQ(b->data))
+			return true;
+	return false;
+}
+
+int bch2_btree_has_scanned_nodes(struct bch_fs *c, enum btree_id btree)
+{
+	int ret = bch2_run_print_explicit_recovery_pass(c, BCH_RECOVERY_PASS_scan_for_btree_nodes);
+	if (ret)
+		return ret;
+
+	struct found_btree_node search = {
+		.btree_id	= btree,
+		.level		= 0,
+		.min_key	= POS_MIN,
+		.max_key	= SPOS_MAX,
+	};
+
+	for_each_found_btree_node_in_range(&c->found_btree_nodes, search, idx)
+		return true;
+	return false;
+}
+
+int bch2_get_scanned_nodes(struct bch_fs *c, enum btree_id btree,
+			   unsigned level, struct bpos node_min, struct bpos node_max)
+{
+	if (btree_id_is_alloc(btree))
+		return 0;
+
+	struct find_btree_nodes *f = &c->found_btree_nodes;
+
+	int ret = bch2_run_print_explicit_recovery_pass(c, BCH_RECOVERY_PASS_scan_for_btree_nodes);
+	if (ret)
+		return ret;
+
+	if (c->opts.verbose) {
+		struct printbuf buf = PRINTBUF;
+
+		prt_str(&buf, "recovery ");
+		bch2_btree_id_level_to_text(&buf, btree, level);
+		prt_str(&buf, " ");
+		bch2_bpos_to_text(&buf, node_min);
+		prt_str(&buf, " - ");
+		bch2_bpos_to_text(&buf, node_max);
+
+		bch_info(c, "%s(): %s", __func__, buf.buf);
+		printbuf_exit(&buf);
+	}
+
+	struct found_btree_node search = {
+		.btree_id	= btree,
+		.level		= level,
+		.min_key	= node_min,
+		.max_key	= node_max,
+	};
+
+	for_each_found_btree_node_in_range(f, search, idx) {
+		struct found_btree_node n = f->nodes.data[idx];
+
+		n.range_updated |= bpos_lt(n.min_key, node_min);
+		n.min_key = bpos_max(n.min_key, node_min);
+
+		n.range_updated |= bpos_gt(n.max_key, node_max);
+		n.max_key = bpos_min(n.max_key, node_max);
+
+		struct { __BKEY_PADDED(k, BKEY_BTREE_PTR_VAL_U64s_MAX); } tmp;
+
+		found_btree_node_to_key(&tmp.k, &n);
+
+		if (c->opts.verbose) {
+			struct printbuf buf = PRINTBUF;
+			bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&tmp.k));
+			bch_verbose(c, "%s(): recovering %s", __func__, buf.buf);
+			printbuf_exit(&buf);
+		}
+
+		BUG_ON(bch2_bkey_validate(c, bkey_i_to_s_c(&tmp.k),
+					  (struct bkey_validate_context) {
+						.from	= BKEY_VALIDATE_btree_node,
+						.level	= level + 1,
+						.btree	= btree,
+					  }));
+
+		ret = bch2_journal_key_insert(c, btree, level + 1, &tmp.k);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+void bch2_find_btree_nodes_exit(struct find_btree_nodes *f)
+{
+	darray_exit(&f->nodes);
+}