[PATCH 1/2] btrfs-progs: Exit gracefully when overlap chunks are detected

[Qu Wenruo <wqu@suse.com>]

BUG_ON() can be triggered if some image contains overlap chunks.
volumes.c:1930: read_one_chunk: BUG_ON `ret` triggered, value -17
btrfs(+0x2cf12)[0x5601efa17f12]
btrfs(+0x2fd8b)[0x5601efa1ad8b]
btrfs(btrfs_read_chunk_tree+0x2bf)[0x5601efa1b30f]
btrfs(btrfs_setup_chunk_tree_and_device_map+0xe8)[0x5601efa07718]
btrfs(+0x1c944)[0x5601efa07944]
btrfs(open_ctree_fs_info+0x90)[0x5601efa07b90]
btrfs(cmd_check+0x4d7)[0x5601efa4f8c7]
btrfs(main+0x88)[0x5601ef9fd768]
/usr/lib/libc.so.6(__libc_start_main+0xeb)[0x7f3c7787306b]
btrfs(_start+0x2a)[0x5601ef9fd88a]

Extent cache code can already detect it without problem, we only need to
remove the BUG_ON() and exit gracefully.

Reported-by: Xu Wen <wen.xu@gatech.edu>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200409
Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 volumes.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/volumes.c b/volumes.c
index 24eb3e8b2578..21a1fc31fcba 100644
--- a/volumes.c
+++ b/volumes.c
@@ -1924,9 +1924,12 @@ static int read_one_chunk(struct btrfs_fs_info *fs_info, struct btrfs_key *key,
 
 	}
 	ret = insert_cache_extent(&map_tree->cache_tree, &map->ce);
-	BUG_ON(ret);
+	if (ret < 0) {
+		error("failed to add chunk map start=%llu len=%llu: %d (%s)",
+		      map->ce.start, map->ce.size, ret, strerror(-ret));
+	}
 
-	return 0;
+	return ret;
 }
 
 static int fill_device_from_item(struct extent_buffer *leaf,
-- 
2.18.0