ocfs2_dlmfs: Fix math error when reading LVB.

commit a36d515c7a2dfacebcf41729f6812dbc424ebcf0 upstream.

When asked for a partial read of the LVB in a dlmfs file, we can
accidentally calculate a negative count.

Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/ocfs2/dlm/dlmfs.c b/fs/ocfs2/dlm/dlmfs.c
index 02bf17808bdc50d1c8f72aa8f8a13664bed5a146..18bc101d603f8176ced2683936f50d8abea0183a 100644 (file)
--- a/fs/ocfs2/dlm/dlmfs.c
+++ b/fs/ocfs2/dlm/dlmfs.c
@@ -205,7 +205,7 @@ static ssize_t dlmfs_file_read(struct file *filp,
        if ((count + *ppos) > i_size_read(inode))
                readlen = i_size_read(inode) - *ppos;
        else
-               readlen = count - *ppos;
+               readlen = count;
 
        lvb_buf = kmalloc(readlen, GFP_NOFS);
        if (!lvb_buf)