[PATCH] reiserfs: fix 32-bit overflow in map_block_for_writepage()

I now see another overflow in reiserfs that should lead to data corruptions
with files that are bigger than 4G under certain circumstances when using
mmap.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index 5f82352..0a044ad 100644 (file)
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -2194,7 +2194,7 @@ static int map_block_for_writepage(struct inode *inode,
        INITIALIZE_PATH(path);
        int pos_in_item;
        int jbegin_count = JOURNAL_PER_BALANCE_CNT;
-       loff_t byte_offset = (block << inode->i_sb->s_blocksize_bits) + 1;
+       loff_t byte_offset = ((loff_t)block << inode->i_sb->s_blocksize_bits)+1;
        int retval;
        int use_get_block = 0;
        int bytes_copied = 0;