xfs
[Top] [All Lists]

[PATCH 2/2] ext4: Fix mmap data corruption when blocksize < pagesize

To: linux-fsdevel@xxxxxxxxxxxxxxx
Subject: [PATCH 2/2] ext4: Fix mmap data corruption when blocksize < pagesize
From: Jan Kara <jack@xxxxxxx>
Date: Fri, 10 Oct 2014 16:23:46 +0200
Cc: linux-ext4@xxxxxxxxxxxxxxx, Dave Chinner <david@xxxxxxxxxxxxx>, xfs@xxxxxxxxxxx, cluster-devel@xxxxxxxxxx, Steven Whitehouse <swhiteho@xxxxxxxxxx>, Mark Fasheh <mfasheh@xxxxxxxx>, Joel Becker <jlbec@xxxxxxxxxxxx>, ocfs2-devel@xxxxxxxxxxxxxx, reiserfs-devel@xxxxxxxxxxxxxxx, Jeff Mahoney <jeffm@xxxxxxx>, Dave Kleikamp <shaggy@xxxxxxxxxx>, jfs-discussion@xxxxxxxxxxxxxxxxxxxxx, tytso@xxxxxxx, viro@xxxxxxxxxxxxxxxxxx, Jan Kara <jack@xxxxxxx>
Delivered-to: xfs@xxxxxxxxxxx
In-reply-to: <1412951028-4085-1-git-send-email-jack@xxxxxxx>
References: <1412951028-4085-1-git-send-email-jack@xxxxxxx>
Use truncate_isize_extended() when hole is being created in a file so that
->page_mkwrite() will get called for the partial tail page if it is
mmaped (see the first patch in the series for details).

Signed-off-by: Jan Kara <jack@xxxxxxx>
---
 fs/ext4/inode.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 3aa26e9117c4..9e269489e094 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4536,8 +4536,12 @@ int ext4_setattr(struct dentry *dentry, struct iattr 
*attr)
                                ext4_orphan_del(NULL, inode);
                                goto err_out;
                        }
-               } else
+               } else {
+                       loff_t oldsize = inode->i_size;
+
                        i_size_write(inode, attr->ia_size);
+                       pagecache_isize_extended(inode, oldsize, inode->i_size);
+               }
 
                /*
                 * Blocks are going to be removed from the inode. Wait
-- 
1.8.1.4

<Prev in Thread] Current Thread [Next in Thread>