[PATCH 1/3] udf: Fix bitmap overflow on large filesystems with small block size

[Jan Kara <jack@suse.cz>]

For large UDF filesystems with 512-byte blocks the number of necessary
bitmap blocks is larger than 2^16 so s_nr_groups in udf_bitmap overflows
(the number will overflow for filesystems larger than 128 GB with
512-byte blocks). That results in ENOSPC errors despite the filesystem
has plenty of free space.

Fix the problem by changing s_nr_groups' type to 'int'. That is enough
even for filesystems 2^32 blocks (UDF maximum) and 512-byte blocksize.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/udf/udf_sb.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/udf/udf_sb.h b/fs/udf/udf_sb.h
index 5f02722..8d1c9d4 100644
--- a/fs/udf/udf_sb.h
+++ b/fs/udf/udf_sb.h
@@ -82,7 +82,7 @@ struct udf_virtual_data {
 struct udf_bitmap {
 	__u32			s_extLength;
 	__u32			s_extPosition;
-	__u16			s_nr_groups;
+	int			s_nr_groups;
 	struct buffer_head 	**s_block_bitmap;
 };
 
-- 
1.7.1