From: Oleg Drokin <green@linuxhacker.ru>
Date: Mon, 28 Nov 2005 21:43:53 +0000 (-0800)
Subject: [PATCH] reiserfs: fix 32-bit overflow in map_block_for_writepage()
X-Git-Tag: v2.6.15-rc3~25
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7729ac5efe156129d172784fedeaddb2167a1914;p=linux-2.6

[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 5f82352b97..0a044ad988 100644
--- 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;