btrfsck: add early code to handle corrupted block groups

This is mostly disabled, but it is step one in handling
corrupted block groups in the extent allocation tree.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

btrfs-corrupt-block.c

@@ -242,11 +242,6 @@ static void btrfs_corrupt_extent_tree(struct btrfs_trans_handle *trans,
 	if (!eb)
 		return;
 
-	if ((rand() % 10) == 0) {
-		corrupt_keys(trans, root, eb);
-		return;
-	}
-
 	nr = btrfs_header_nritems(eb);
 	if (btrfs_is_leaf(eb)) {
 		btrfs_corrupt_extent_leaf(trans, root, eb);

btrfsck.c

@@ -26,6 +26,7 @@
 #include <getopt.h>
 #include "kerncompat.h"
 #include "ctree.h"
+#include "volumes.h"
 #include "repair.h"
 #include "disk-io.h"
 #include "print-tree.h"
@@ -3140,6 +3141,55 @@ static void free_corrupt_blocks(struct btrfs_fs_info *info)
 	}
 }
 
+static int check_block_group(struct btrfs_trans_handle *trans,
+			      struct btrfs_fs_info *info,
+			      struct map_lookup *map,
+			      int *reinit)
+{
+	struct btrfs_key key;
+	struct btrfs_path path;
+	int ret;
+
+	key.objectid = map->ce.start;
+	key.offset = map->ce.size;
+	key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
+
+	btrfs_init_path(&path);
+	ret = btrfs_search_slot(NULL, info->extent_root,
+				&key, &path, 0, 0);
+	btrfs_release_path(NULL, &path);
+	if (ret <= 0)
+		goto out;
+
+	ret = btrfs_make_block_group(trans, info->extent_root, 0, map->type,
+			       BTRFS_FIRST_CHUNK_TREE_OBJECTID,
+			       key.objectid, key.offset);
+	*reinit = 1;
+out:
+	return ret;
+}
+
+static int check_block_groups(struct btrfs_trans_handle *trans,
+			      struct btrfs_fs_info *info, int *reinit)
+{
+	struct cache_extent *ce;
+	struct map_lookup *map;
+	struct btrfs_mapping_tree *map_tree = &info->mapping_tree;
+
+	/* this isn't quite working */
+	return 0;
+
+	ce = find_first_cache_extent(&map_tree->cache_tree, 0);
+	while (1) {
+		if (!ce)
+			break;
+		map = container_of(ce, struct map_lookup, ce);
+		check_block_group(trans, info, map, reinit);
+		ce = next_cache_extent(ce);
+	}
+	return 0;
+}
+
 static int check_extent_refs(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
 			     struct cache_tree *extent_cache, int repair)
@@ -3149,6 +3199,7 @@ static int check_extent_refs(struct btrfs_trans_handle *trans,
 	int err = 0;
 	int ret = 0;
 	int fixed = 0;
+	int reinit = 0;
 
 	if (repair) {
 		/*
@@ -3174,6 +3225,9 @@ static int check_extent_refs(struct btrfs_trans_handle *trans,
 			cache = next_cache_extent(cache);
 		}
 		prune_corrupt_blocks(trans, root->fs_info);
+		check_block_groups(trans, root->fs_info, &reinit);
+		if (reinit)
+			btrfs_read_block_groups(root->fs_info->extent_root);
 	}
 	while(1) {
 		fixed = 0;
@@ -3356,6 +3410,7 @@ static struct option long_options[] = {
 	{ "super", 1, NULL, 's' },
 	{ "repair", 0, NULL, 0 },
 	{ "init-csum-tree", 0, NULL, 0 },
+	{ "init-extent-tree", 0, NULL, 0 },
 	{ 0, 0, 0, 0}
 };
 
@@ -3444,7 +3499,6 @@ int main(int ac, char **av)
 		}
 		goto out;
 	}
-
 	ret = check_extents(trans, root, repair);
 	if (ret)
 		fprintf(stderr, "Errors found in extent allocation tree\n");

ctree.c

@@ -151,8 +151,10 @@ int btrfs_fsck_reinit_root(struct btrfs_trans_handle *trans,
 				   btrfs_level_size(root, 0),
 				   root->root_key.objectid,
 				   &disk_key, level, 0, 0);
-	if (IS_ERR(c))
-		return PTR_ERR(c);
+	if (IS_ERR(c)) {
+		c = old;
+		extent_buffer_get(c);
+	}
 
 	memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
 	btrfs_set_header_level(c, level);
@@ -1262,6 +1264,8 @@ again:
 						 key->objectid);
 
 			b = read_node_slot(root, b, slot);
+			if (!extent_buffer_uptodate(b))
+				return -EIO;
 		} else {
 			p->slots[level] = slot;
 			if (ins_len > 0 &&

extent-tree.c

@@ -1703,7 +1703,6 @@ int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
 
 		cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
 		ret = write_one_cache_group(trans, root, path, cache);
-		BUG_ON(ret);
 	}
 	btrfs_free_path(path);
 	return 0;
@@ -1894,6 +1893,10 @@ static int update_pinned_extents(struct btrfs_root *root,
 	}
 	while (num > 0) {
 		cache = btrfs_lookup_block_group(fs_info, bytenr);
+		if (!cache) {
+			len = min((u64)root->sectorsize, num);
+			goto next;
+		}
 		WARN_ON(!cache);
 		len = min(num, cache->key.offset -
 			  (bytenr - cache->key.objectid));
@@ -1906,6 +1909,7 @@ static int update_pinned_extents(struct btrfs_root *root,
 			cache->space_info->bytes_pinned -= len;
 			fs_info->total_pinned -= len;
 		}
+next:
 		bytenr += len;
 		num -= len;
 	}
@@ -2263,9 +2267,7 @@ static int __free_extent(struct btrfs_trans_handle *trans,
 			BUG_ON(ret);
 		}
 
-		ret = update_block_group(trans, root, bytenr, num_bytes, 0,
-					 mark_free);
-		BUG_ON(ret);
+		update_block_group(trans, root, bytenr, num_bytes, 0, mark_free);
 	}
 fail:
 	btrfs_free_path(path);
@@ -2596,13 +2598,7 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 
 	ret = update_block_group(trans, root, ins->objectid, ins->offset,
 				 1, 0);
-	if (ret) {
-		printk(KERN_ERR "btrfs update block group failed for %llu "
-		       "%llu\n", (unsigned long long)ins->objectid,
-		       (unsigned long long)ins->offset);
-		BUG();
-	}
-	return ret;
+	return 0;
 }
 
 static int alloc_tree_block(struct btrfs_trans_handle *trans,
@@ -3185,7 +3181,6 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
 
 	finish_current_insert(trans, extent_root);
 	ret = del_pending_extents(trans, extent_root);
-	BUG_ON(ret);
 	set_avail_alloc_bits(extent_root->fs_info, type);
 	return 0;
 }

volumes.c

@@ -35,18 +35,6 @@ struct stripe {
 	u64 physical;
 };
 
-struct map_lookup {
-	struct cache_extent ce;
-	u64 type;
-	int io_align;
-	int io_width;
-	int stripe_len;
-	int sector_size;
-	int num_stripes;
-	int sub_stripes;
-	struct btrfs_bio_stripe stripes[];
-};
-
 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
 			    (sizeof(struct btrfs_bio_stripe) * (n)))
 

volumes.h

@@ -18,6 +18,7 @@
 
 #ifndef __BTRFS_VOLUMES_
 #define __BTRFS_VOLUMES_
+
 struct btrfs_device {
 	struct list_head dev_list;
 	struct btrfs_root *dev_root;
@@ -88,6 +89,18 @@ struct btrfs_multi_bio {
 	struct btrfs_bio_stripe stripes[];
 };
 
+struct map_lookup {
+	struct cache_extent ce;
+	u64 type;
+	int io_align;
+	int io_width;
+	int stripe_len;
+	int sector_size;
+	int num_stripes;
+	int sub_stripes;
+	struct btrfs_bio_stripe stripes[];
+};
+
 #define btrfs_multi_bio_size(n) (sizeof(struct btrfs_multi_bio) + \
 			    (sizeof(struct btrfs_bio_stripe) * (n)))