1 files changed, 513 insertions, 0 deletions

diff --git a/libbcache/debug.c b/libbcache/debug.c
new file mode 100644
index 00000000..1be2e607
--- /dev/null
+++ b/libbcache/debug.c
@@ -0,0 +1,513 @@
+/*
+ * Assorted bcache debug code
+ *
+ * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
+ * Copyright 2012 Google, Inc.
+ */
+
+#include "bcache.h"
+#include "bkey_methods.h"
+#include "btree_cache.h"
+#include "btree_io.h"
+#include "btree_iter.h"
+#include "btree_update.h"
+#include "buckets.h"
+#include "debug.h"
+#include "error.h"
+#include "extents.h"
+#include "fs-gc.h"
+#include "inode.h"
+#include "io.h"
+#include "super.h"
+
+#include <linux/console.h>
+#include <linux/debugfs.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/seq_file.h>
+
+static struct dentry *bch_debug;
+
+#ifdef CONFIG_BCACHE_DEBUG
+
+static void btree_verify_endio(struct bio *bio)
+{
+	struct closure *cl = bio->bi_private;
+
+	closure_put(cl);
+}
+
+void __bch_btree_verify(struct cache_set *c, struct btree *b)
+{
+	struct btree *v = c->verify_data;
+	struct btree_node *n_ondisk, *n_sorted, *n_inmemory;
+	struct bset *sorted, *inmemory;
+	struct extent_pick_ptr pick;
+	struct bio *bio;
+	struct closure cl;
+
+	closure_init_stack(&cl);
+
+	btree_node_io_lock(b);
+	mutex_lock(&c->verify_lock);
+
+	n_ondisk = c->verify_ondisk;
+	n_sorted = c->verify_data->data;
+	n_inmemory = b->data;
+
+	bkey_copy(&v->key, &b->key);
+	v->written	= 0;
+	v->level	= b->level;
+	v->btree_id	= b->btree_id;
+	bch_btree_keys_init(v, &c->expensive_debug_checks);
+
+	pick = bch_btree_pick_ptr(c, b);
+	if (IS_ERR_OR_NULL(pick.ca))
+		return;
+
+	bio = bio_alloc_bioset(GFP_NOIO, btree_pages(c), &c->btree_read_bio);
+	bio->bi_bdev		= pick.ca->disk_sb.bdev;
+	bio->bi_iter.bi_sector	= pick.ptr.offset;
+	bio->bi_iter.bi_size	= btree_bytes(c);
+	bio_set_op_attrs(bio, REQ_OP_READ, REQ_META|READ_SYNC);
+	bio->bi_private		= &cl;
+	bio->bi_end_io		= btree_verify_endio;
+	bch_bio_map(bio, n_sorted);
+
+	closure_get(&cl);
+	bch_generic_make_request(bio, c);
+	closure_sync(&cl);
+
+	bio_put(bio);
+
+	memcpy(n_ondisk, n_sorted, btree_bytes(c));
+
+	bch_btree_node_read_done(c, v, pick.ca, &pick.ptr);
+	n_sorted = c->verify_data->data;
+
+	percpu_ref_put(&pick.ca->ref);
+
+	sorted = &n_sorted->keys;
+	inmemory = &n_inmemory->keys;
+
+	if (inmemory->u64s != sorted->u64s ||
+	    memcmp(inmemory->start,
+		   sorted->start,
+		   (void *) bset_bkey_last(inmemory) - (void *) inmemory->start)) {
+		unsigned offset = 0, sectors;
+		struct bset *i;
+		unsigned j;
+
+		console_lock();
+
+		printk(KERN_ERR "*** in memory:\n");
+		bch_dump_bset(b, inmemory, 0);
+
+		printk(KERN_ERR "*** read back in:\n");
+		bch_dump_bset(v, sorted, 0);
+
+		while (offset < b->written) {
+			if (!offset ) {
+				i = &n_ondisk->keys;
+				sectors = __set_blocks(n_ondisk,
+						       le16_to_cpu(n_ondisk->keys.u64s),
+						       block_bytes(c)) <<
+					c->block_bits;
+			} else {
+				struct btree_node_entry *bne =
+					(void *) n_ondisk + (offset << 9);
+				i = &bne->keys;
+
+				sectors = __set_blocks(bne,
+						       le16_to_cpu(bne->keys.u64s),
+						       block_bytes(c)) <<
+					c->block_bits;
+			}
+
+			printk(KERN_ERR "*** on disk block %u:\n", offset);
+			bch_dump_bset(b, i, offset);
+
+			offset += sectors;
+		}
+
+		printk(KERN_ERR "*** block %u/%u not written\n",
+		       offset >> c->block_bits, btree_blocks(c));
+
+		for (j = 0; j < le16_to_cpu(inmemory->u64s); j++)
+			if (inmemory->_data[j] != sorted->_data[j])
+				break;
+
+		printk(KERN_ERR "b->written %u\n", b->written);
+
+		console_unlock();
+		panic("verify failed at %u\n", j);
+	}
+
+	mutex_unlock(&c->verify_lock);
+	btree_node_io_unlock(b);
+}
+
+void bch_data_verify(struct cached_dev *dc, struct bio *bio)
+{
+	char name[BDEVNAME_SIZE];
+	struct bio *check;
+	struct bio_vec bv;
+	struct bvec_iter iter;
+
+	check = bio_clone(bio, GFP_NOIO);
+	if (!check)
+		return;
+	bio_set_op_attrs(check, REQ_OP_READ, READ_SYNC);
+
+	if (bio_alloc_pages(check, GFP_NOIO))
+		goto out_put;
+
+	submit_bio_wait(check);
+
+	bio_for_each_segment(bv, bio, iter) {
+		void *p1 = kmap_atomic(bv.bv_page);
+		void *p2 = page_address(check->bi_io_vec[iter.bi_idx].bv_page);
+
+		if (memcmp(p1 + bv.bv_offset,
+			   p2 + bv.bv_offset,
+			   bv.bv_len))
+			panic("verify failed at dev %s sector %llu\n",
+			      bdevname(dc->disk_sb.bdev, name),
+			      (uint64_t) bio->bi_iter.bi_sector);
+
+		kunmap_atomic(p1);
+	}
+
+	bio_free_pages(check);
+out_put:
+	bio_put(check);
+}
+
+#endif
+
+#ifdef CONFIG_DEBUG_FS
+
+/* XXX: cache set refcounting */
+
+struct dump_iter {
+	struct bpos		from;
+	struct cache_set	*c;
+	enum btree_id		id;
+
+	char			buf[PAGE_SIZE];
+	size_t			bytes;	/* what's currently in buf */
+
+	char __user		*ubuf;	/* destination user buffer */
+	size_t			size;	/* size of requested read */
+	ssize_t			ret;	/* bytes read so far */
+};
+
+static int flush_buf(struct dump_iter *i)
+{
+	if (i->bytes) {
+		size_t bytes = min(i->bytes, i->size);
+		int err = copy_to_user(i->ubuf, i->buf, bytes);
+
+		if (err)
+			return err;
+
+		i->ret	 += bytes;
+		i->ubuf	 += bytes;
+		i->size	 -= bytes;
+		i->bytes -= bytes;
+		memmove(i->buf, i->buf + bytes, i->bytes);
+	}
+
+	return 0;
+}
+
+static int bch_dump_open(struct inode *inode, struct file *file)
+{
+	struct btree_debug *bd = inode->i_private;
+	struct dump_iter *i;
+
+	i = kzalloc(sizeof(struct dump_iter), GFP_KERNEL);
+	if (!i)
+		return -ENOMEM;
+
+	file->private_data = i;
+	i->from = POS_MIN;
+	i->c	= container_of(bd, struct cache_set, btree_debug[bd->id]);
+	i->id	= bd->id;
+
+	return 0;
+}
+
+static int bch_dump_release(struct inode *inode, struct file *file)
+{
+	kfree(file->private_data);
+	return 0;
+}
+
+static ssize_t bch_read_btree(struct file *file, char __user *buf,
+			      size_t size, loff_t *ppos)
+{
+	struct dump_iter *i = file->private_data;
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	int err;
+
+	i->ubuf = buf;
+	i->size	= size;
+	i->ret	= 0;
+
+	err = flush_buf(i);
+	if (err)
+		return err;
+
+	if (!i->size)
+		return i->ret;
+
+	bch_btree_iter_init(&iter, i->c, i->id, i->from);
+
+	while ((k = bch_btree_iter_peek(&iter)).k &&
+	       !(err = btree_iter_err(k))) {
+		bch_bkey_val_to_text(i->c, bkey_type(0, i->id),
+				     i->buf, sizeof(i->buf), k);
+		i->bytes = strlen(i->buf);
+		BUG_ON(i->bytes >= PAGE_SIZE);
+		i->buf[i->bytes] = '\n';
+		i->bytes++;
+
+		bch_btree_iter_advance_pos(&iter);
+		i->from = iter.pos;
+
+		err = flush_buf(i);
+		if (err)
+			break;
+
+		if (!i->size)
+			break;
+	}
+	bch_btree_iter_unlock(&iter);
+
+	return err < 0 ? err : i->ret;
+}
+
+static const struct file_operations btree_debug_ops = {
+	.owner		= THIS_MODULE,
+	.open		= bch_dump_open,
+	.release	= bch_dump_release,
+	.read		= bch_read_btree,
+};
+
+static int print_btree_node(struct dump_iter *i, struct btree *b)
+{
+	const struct bkey_format *f = &b->format;
+	struct bset_stats stats;
+
+	memset(&stats, 0, sizeof(stats));
+
+	bch_btree_keys_stats(b, &stats);
+
+	i->bytes = scnprintf(i->buf, sizeof(i->buf),
+			     "l %u %llu:%llu - %llu:%llu:\n"
+			     "    format: u64s %u fields %u %u %u %u %u\n"
+			     "    unpack fn len: %u\n"
+			     "    bytes used %zu/%zu (%zu%% full)\n"
+			     "    sib u64s: %u, %u (merge threshold %zu)\n"
+			     "    nr packed keys %u\n"
+			     "    nr unpacked keys %u\n"
+			     "    floats %zu\n"
+			     "    failed unpacked %zu\n"
+			     "    failed prev %zu\n"
+			     "    failed overflow %zu\n",
+			     b->level,
+			     b->data->min_key.inode,
+			     b->data->min_key.offset,
+			     b->data->max_key.inode,
+			     b->data->max_key.offset,
+			     f->key_u64s,
+			     f->bits_per_field[0],
+			     f->bits_per_field[1],
+			     f->bits_per_field[2],
+			     f->bits_per_field[3],
+			     f->bits_per_field[4],
+			     b->unpack_fn_len,
+			     b->nr.live_u64s * sizeof(u64),
+			     btree_bytes(i->c) - sizeof(struct btree_node),
+			     b->nr.live_u64s * 100 / btree_max_u64s(i->c),
+			     b->sib_u64s[0],
+			     b->sib_u64s[1],
+			     BTREE_FOREGROUND_MERGE_THRESHOLD(i->c),
+			     b->nr.packed_keys,
+			     b->nr.unpacked_keys,
+			     stats.floats,
+			     stats.failed_unpacked,
+			     stats.failed_prev,
+			     stats.failed_overflow);
+
+	return flush_buf(i);
+}
+
+static ssize_t bch_read_btree_formats(struct file *file, char __user *buf,
+				      size_t size, loff_t *ppos)
+{
+	struct dump_iter *i = file->private_data;
+	struct btree_iter iter;
+	struct btree *b;
+	int err;
+
+	i->ubuf = buf;
+	i->size	= size;
+	i->ret	= 0;
+
+	err = flush_buf(i);
+	if (err)
+		return err;
+
+	if (!i->size || !bkey_cmp(POS_MAX, i->from))
+		return i->ret;
+
+	for_each_btree_node(&iter, i->c, i->id, i->from, 0, b) {
+		err = print_btree_node(i, b);
+		if (err)
+			break;
+
+		/*
+		 * can't easily correctly restart a btree node traversal across
+		 * all nodes, meh
+		 */
+		i->from = bkey_cmp(POS_MAX, b->key.k.p)
+			? bkey_successor(b->key.k.p)
+			: b->key.k.p;
+
+		if (!i->size)
+			break;
+	}
+	bch_btree_iter_unlock(&iter);
+
+	return err < 0 ? err : i->ret;
+}
+
+static const struct file_operations btree_format_debug_ops = {
+	.owner		= THIS_MODULE,
+	.open		= bch_dump_open,
+	.release	= bch_dump_release,
+	.read		= bch_read_btree_formats,
+};
+
+static ssize_t bch_read_bfloat_failed(struct file *file, char __user *buf,
+				      size_t size, loff_t *ppos)
+{
+	struct dump_iter *i = file->private_data;
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	struct btree *prev_node = NULL;
+	int err;
+
+	i->ubuf = buf;
+	i->size	= size;
+	i->ret	= 0;
+
+	err = flush_buf(i);
+	if (err)
+		return err;
+
+	if (!i->size)
+		return i->ret;
+
+	bch_btree_iter_init(&iter, i->c, i->id, i->from);
+
+	while ((k = bch_btree_iter_peek(&iter)).k &&
+	       !(err = btree_iter_err(k))) {
+		struct btree *b = iter.nodes[0];
+		struct btree_node_iter *node_iter = &iter.node_iters[0];
+		struct bkey_packed *_k = bch_btree_node_iter_peek(node_iter, b);
+
+		if (iter.nodes[0] != prev_node) {
+			err = print_btree_node(i, iter.nodes[0]);
+			if (err)
+				break;
+		}
+		prev_node = iter.nodes[0];
+
+		i->bytes = bch_bkey_print_bfloat(b, _k, i->buf, sizeof(i->buf));
+
+		err = flush_buf(i);
+		if (err)
+			break;
+
+		bch_btree_iter_advance_pos(&iter);
+		i->from = iter.pos;
+
+		err = flush_buf(i);
+		if (err)
+			break;
+
+		if (!i->size)
+			break;
+	}
+	bch_btree_iter_unlock(&iter);
+
+	return err < 0 ? err : i->ret;
+}
+
+static const struct file_operations bfloat_failed_debug_ops = {
+	.owner		= THIS_MODULE,
+	.open		= bch_dump_open,
+	.release	= bch_dump_release,
+	.read		= bch_read_bfloat_failed,
+};
+
+void bch_debug_exit_cache_set(struct cache_set *c)
+{
+	if (!IS_ERR_OR_NULL(c->debug))
+		debugfs_remove_recursive(c->debug);
+}
+
+void bch_debug_init_cache_set(struct cache_set *c)
+{
+	struct btree_debug *bd;
+	char name[100];
+
+	if (IS_ERR_OR_NULL(bch_debug))
+		return;
+
+	snprintf(name, sizeof(name), "%pU", c->disk_sb.user_uuid.b);
+	c->debug = debugfs_create_dir(name, bch_debug);
+	if (IS_ERR_OR_NULL(c->debug))
+		return;
+
+	for (bd = c->btree_debug;
+	     bd < c->btree_debug + ARRAY_SIZE(c->btree_debug);
+	     bd++) {
+		bd->id = bd - c->btree_debug;
+		bd->btree = debugfs_create_file(bch_btree_id_names[bd->id],
+						0400, c->debug, bd,
+						&btree_debug_ops);
+
+		snprintf(name, sizeof(name), "%s-formats",
+			 bch_btree_id_names[bd->id]);
+
+		bd->btree_format = debugfs_create_file(name, 0400, c->debug, bd,
+						       &btree_format_debug_ops);
+
+		snprintf(name, sizeof(name), "%s-bfloat-failed",
+			 bch_btree_id_names[bd->id]);
+
+		bd->failed = debugfs_create_file(name, 0400, c->debug, bd,
+						 &bfloat_failed_debug_ops);
+	}
+}
+
+#endif
+
+void bch_debug_exit(void)
+{
+	if (!IS_ERR_OR_NULL(bch_debug))
+		debugfs_remove_recursive(bch_debug);
+}
+
+int __init bch_debug_init(void)
+{
+	int ret = 0;
+
+	bch_debug = debugfs_create_dir("bcache", NULL);
+	return ret;
+}