ocfs2: fix incorrect i_size of global bitmap inode after resize

Ocfs2 cluster size may be 1MB, which has 20 bits.  When resize, the
input new clusters is mostly the number of clusters in a group
descriptor(32256).

Since the input clusters is defined as type int, so it will overflow
when shift left 20 bits and then lead to incorrect global bitmap i_size.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/resize.c

@@ -153,7 +153,7 @@ static int ocfs2_update_last_group_and_inode(handle_t *handle,
 
 	spin_lock(&OCFS2_I(bm_inode)->ip_lock);
 	OCFS2_I(bm_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
-	le64_add_cpu(&fe->i_size, new_clusters << osb->s_clustersize_bits);
+	le64_add_cpu(&fe->i_size, (u64)new_clusters << osb->s_clustersize_bits);
 	spin_unlock(&OCFS2_I(bm_inode)->ip_lock);
 	i_size_write(bm_inode, le64_to_cpu(fe->i_size));
 
@@ -563,7 +563,7 @@ int ocfs2_group_add(struct inode *inode, struct ocfs2_new_group_input *input)
 
 	spin_lock(&OCFS2_I(main_bm_inode)->ip_lock);
 	OCFS2_I(main_bm_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
-	le64_add_cpu(&fe->i_size, input->clusters << osb->s_clustersize_bits);
+	le64_add_cpu(&fe->i_size, (u64)input->clusters << osb->s_clustersize_bits);
 	spin_unlock(&OCFS2_I(main_bm_inode)->ip_lock);
 	i_size_write(main_bm_inode, le64_to_cpu(fe->i_size));