btrfs-progs: mkfs: avoid BUG_ON for chunk allocation when ENOSPC happens

When passing directory larger than block device using --rootdir
parameter, we get the following backtrace:

------
extent-tree.c:2693: btrfs_reserve_extent: BUG_ON `ret` triggered, value -28
./mkfs.btrfs(+0x1a05d)[0x557939e6b05d]
./mkfs.btrfs(btrfs_reserve_extent+0xb5a)[0x557939e710c8]
./mkfs.btrfs(+0xb0b6)[0x557939e5c0b6]
./mkfs.btrfs(main+0x15d5)[0x557939e5de04]
/usr/lib/libc.so.6(__libc_start_main+0xea)[0x7f83b101af6a]
./mkfs.btrfs(_start+0x2a)[0x557939e5af5a]
------

Nothing special, just BUG_ON() abusing from ancient code.

Fix them by using correct return.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 14 insertions, 4 deletions

diff --git a/volumes.c b/volumes.c
index 2fde4762..e3654a4c 100644
--- a/volumes.c
+++ b/volumes.c
@@ -1046,11 +1046,13 @@ again:
 			     info->chunk_root->root_key.objectid,
 			     BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
 			     calc_size, &dev_offset, 0);
-		BUG_ON(ret);
+		if (ret < 0)
+			goto out_chunk_map;
 
 		device->bytes_used += calc_size;
 		ret = btrfs_update_device(trans, device);
-		BUG_ON(ret);
+		if (ret < 0)
+			goto out_chunk_map;
 
 		map->stripes[index].dev = device;
 		map->stripes[index].physical = dev_offset;
@@ -1089,16 +1091,24 @@ again:
 	map->ce.size = *num_bytes;
 
 	ret = insert_cache_extent(&info->mapping_tree.cache_tree, &map->ce);
-	BUG_ON(ret);
+	if (ret < 0)
+		goto out_chunk_map;
 
 	if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
 		ret = btrfs_add_system_chunk(info, &key,
 				    chunk, btrfs_chunk_item_size(num_stripes));
-		BUG_ON(ret);
+		if (ret < 0)
+			goto out_chunk;
 	}
 
 	kfree(chunk);
 	return ret;
+
+out_chunk_map:
+	kfree(map);
+out_chunk:
+	kfree(chunk);
+	return ret;
 }
 
 /*