[Ocfs2-devel] [PATCH] ocfs2: Use buffer IO if we are appending a file.

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

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

Tao Ma wrote:

> In ocfs2_file_aio_write, we will prevent direct io if
> we find that we are appending(changing i_size) and call
> generic_file_aio_write_nolock. But actually O_DIRECT flag
> is there and this function will call generic_file_direct_write
> eventually which will update i_size and leave di->i_size
> alone. The bug is that
> http://oss.oracle.com/bugzilla/show_bug.cgi?id=1173.
>
> So this patch let ocfs2_direct_IO returns 0 directly if we
> are appending so that buffered write will be called and
> di->i_size get updated successfully. And this is also
> what we want in ocfs2_file_aio_write.
>
> Signed-off-by: Tao Ma <tao.ma@oracle.com>
> ---
>  fs/ocfs2/aops.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
> index c4c567e..769e5d0 100644
> --- a/fs/ocfs2/aops.c
> +++ b/fs/ocfs2/aops.c
> @@ -690,6 +690,10 @@ static ssize_t ocfs2_direct_IO(int rw,
>  	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
>  		return 0;
>  
> +	/* Fallback to buffered I/O if we are appending. */
> +	if (i_size_read(inode) <= offset)
> +		return 0;
> +
>  	ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
>  					    inode->i_sb->s_bdev, iov, offset,
>  					    nr_segs, 
>