Re: [Ocfs2-devel] [PATCH 09/11] ocfs2_dlmfs: Don't honor truncate. The size of a dlmfs file is LVB_LEN

[Sunil Mushran <sunil.mushran@oracle.com>]

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>


Joel Becker wrote:
> We want folks using dlmfs to be able to use the LVB in places other than
> just write(2)/read(2).  By ignoring truncate requests, we allow 'echo
> "contents" > /dlm/space/lockname' to work.
>
> Signed-off-by: Joel Becker <joel.becker@oracle.com>
> ---
>  fs/ocfs2/dlmfs/dlmfs.c |   18 ++++++++++++++++++
>  1 files changed, 18 insertions(+), 0 deletions(-)
>
> diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c
> index e21ce0e..13ac2bf 100644
> --- a/fs/ocfs2/dlmfs/dlmfs.c
> +++ b/fs/ocfs2/dlmfs/dlmfs.c
> @@ -220,6 +220,23 @@ static int dlmfs_file_release(struct inode *inode,
>  	return 0;
>  }
>  
> +/*
> + * We do ->setattr() just to override size changes.  Our size is the size
> + * of the LVB and nothing else.
> + */
> +static int dlmfs_file_setattr(struct dentry *dentry, struct iattr *attr)
> +{
> +	int error;
> +	struct inode *inode = dentry->d_inode;
> +
> +	attr->ia_valid &= ~ATTR_SIZE;
> +	error = inode_change_ok(inode, attr);
> +	if (!error)
> +		error = inode_setattr(inode, attr);
> +
> +	return error;
> +}
> +
>  static unsigned int dlmfs_file_poll(struct file *file, poll_table *wait)
>  {
>  	int event = 0;
> @@ -634,6 +651,7 @@ static const struct super_operations dlmfs_ops = {
>  
>  static const struct inode_operations dlmfs_file_inode_operations = {
>  	.getattr	= simple_getattr,
> +	.setattr	= dlmfs_file_setattr,
>  };
>  
>  static int dlmfs_get_sb(struct file_system_type *fs_type,
>