[PATCH 0/3] UDF overflow fix and cleanups

[PATCH 0/3] UDF overflow fix and cleanups

[Jan Kara]

  Hi,

  I've added the three patches in this series to my tree and plan to
merge them in the next merge window. The first patch fixes an overflow
in handling large filesystems with small block size, the other two
patches are just cleanups.

							Honza

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

[Jan Kara]

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

[PATCH 2/3] udf: Make s_block_bitmap standard array

[Jan Kara]

struct udf_bitmap has array of buffer pointers attached to it. The code
unnecessarily used s_block_bitmap as a pointer to the array instead of
the standard trick of using 0 length array in the declaration. Change
that to make code more readable and actually shrink the structure by one
pointer.

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

diff --git a/fs/udf/super.c b/fs/udf/super.c
index da8ce9f..f883080 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1023,7 +1023,6 @@ static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb, u32 index)
 	if (bitmap == NULL)
 		return NULL;
 
-	bitmap->s_block_bitmap = (struct buffer_head **)(bitmap + 1);
 	bitmap->s_nr_groups = nr_groups;
 	return bitmap;
 }
diff --git a/fs/udf/udf_sb.h b/fs/udf/udf_sb.h
index 8d1c9d4..4f7ddb7 100644
--- a/fs/udf/udf_sb.h
+++ b/fs/udf/udf_sb.h
@@ -83,7 +83,7 @@ struct udf_bitmap {
 	__u32			s_extLength;
 	__u32			s_extPosition;
 	int			s_nr_groups;
-	struct buffer_head 	**s_block_bitmap;
+	struct buffer_head 	*s_block_bitmap[0];
 };
 
 struct udf_part_map {
-- 
1.7.1

[PATCH 3/3] udf: Remove unused s_extLength from udf_bitmap

[Jan Kara]

s_extLength was assigned to but the value was never really used. So
just remove the field.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/udf/super.c  |    4 ----
 fs/udf/udf_sb.h |    1 -
 2 files changed, 0 insertions(+), 5 deletions(-)

diff --git a/fs/udf/super.c b/fs/udf/super.c
index f883080..bc5b30a 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1080,8 +1080,6 @@ static int udf_fill_partdesc_info(struct super_block *sb,
 		if (!bitmap)
 			return 1;
 		map->s_uspace.s_bitmap = bitmap;
-		bitmap->s_extLength = le32_to_cpu(
-				phd->unallocSpaceBitmap.extLength);
 		bitmap->s_extPosition = le32_to_cpu(
 				phd->unallocSpaceBitmap.extPosition);
 		map->s_partition_flags |= UDF_PART_FLAG_UNALLOC_BITMAP;
@@ -1116,8 +1114,6 @@ static int udf_fill_partdesc_info(struct super_block *sb,
 		if (!bitmap)
 			return 1;
 		map->s_fspace.s_bitmap = bitmap;
-		bitmap->s_extLength = le32_to_cpu(
-				phd->freedSpaceBitmap.extLength);
 		bitmap->s_extPosition = le32_to_cpu(
 				phd->freedSpaceBitmap.extPosition);
 		map->s_partition_flags |= UDF_PART_FLAG_FREED_BITMAP;
diff --git a/fs/udf/udf_sb.h b/fs/udf/udf_sb.h
index 4f7ddb7..ed401e9 100644
--- a/fs/udf/udf_sb.h
+++ b/fs/udf/udf_sb.h
@@ -80,7 +80,6 @@ struct udf_virtual_data {
 };
 
 struct udf_bitmap {
-	__u32			s_extLength;
 	__u32			s_extPosition;
 	int			s_nr_groups;
 	struct buffer_head 	*s_block_bitmap[0];
-- 
1.7.1