0003-Btrfs-progs-fsck-deal-with-really-corrupted-extent-t.patch

From 6a14ab7a538c1e0f9192ed166c5183e7639bcf57 Mon Sep 17 00:00:00 2001
From: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Date: Sat, 1 Mar 2014 14:34:59 +0800
Subject: [PATCH 3/3] Btrfs-progs: fsck: deal with really corrupted extent tree

We may have a really corrupted extent tree, so we can't really
rely on existed extent tree to cache block group.

During test, we fail to reinit extent tree which is because we
can not find a free extent so let's make block group cache ourselves
firstly.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
---
 cmds-check.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/cmds-check.c b/cmds-check.c
index e431ae1..ba544df 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -6053,11 +6053,13 @@ static int pin_metadata_blocks(struct btrfs_fs_info *fs_info)
 
 static int reset_block_groups(struct btrfs_fs_info *fs_info)
 {
+	struct btrfs_block_group_cache *cache;
 	struct btrfs_path *path;
 	struct extent_buffer *leaf;
 	struct btrfs_chunk *chunk;
 	struct btrfs_key key;
 	int ret;
+	u64 start;
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -6108,8 +6110,20 @@ static int reset_block_groups(struct btrfs_fs_info *fs_info)
 				      btrfs_chunk_type(leaf, chunk),
 				      key.objectid, key.offset,
 				      btrfs_chunk_length(leaf, chunk));
+		set_extent_dirty(&fs_info->free_space_cache, key.offset,
+				 key.offset + btrfs_chunk_length(leaf, chunk),
+				 GFP_NOFS);
 		path->slots[0]++;
 	}
+	start = 0;
+	while (1) {
+		cache = btrfs_lookup_first_block_group(fs_info, start);
+		if (!cache)
+			break;
+		if (cache->cached)
+			cache->cached = 1;
+		start = cache->key.objectid + cache->key.offset;
+	}
 
 	btrfs_free_path(path);
 	return 0;
@@ -6263,12 +6277,6 @@ static int reinit_extent_tree(struct btrfs_trans_handle *trans,
 		return ret;
 	}
 
-	ret = reset_balance(trans, fs_info);
-	if (ret) {
-		fprintf(stderr, "error reseting the pending balance\n");
-		return ret;
-	}
-
 	/* Ok we can allocate now, reinit the extent root */
 	ret = btrfs_fsck_reinit_root(trans, fs_info->extent_root, 0);
 	if (ret) {
@@ -6303,7 +6311,11 @@ static int reinit_extent_tree(struct btrfs_trans_handle *trans,
 		btrfs_extent_post_op(trans, fs_info->extent_root);
 	}
 
-	return 0;
+	ret = reset_balance(trans, fs_info);
+	if (ret)
+		fprintf(stderr, "error reseting the pending balance\n");
+
+	return ret;
 }
 
 static int recow_extent_buffer(struct btrfs_root *root, struct extent_buffer *eb)
-- 
1.9.0