[Ocfs2-tools-devel] [PATCH 14/44] ocfs2: Integrate CoW in file write.

[Joel Becker]

On Mon, Dec 28, 2009 at 05:00:59PM +0800, Tao Ma wrote:
> Call ocfs2_refcount_cow first to CoW refcounted clusters
> in ocfs2_file_block_write.
> 
> Signed-off-by: Tao Ma <tao.ma at oracle.com>
> ---
>  libocfs2/fileio.c |    9 +++++++++
>  1 files changed, 9 insertions(+), 0 deletions(-)
> 
> diff --git a/libocfs2/fileio.c b/libocfs2/fileio.c
> index c4664ec..78ef5f5 100644
> --- a/libocfs2/fileio.c
> +++ b/libocfs2/fileio.c
> @@ -33,6 +33,7 @@
>  #include <inttypes.h>
>  
>  #include "ocfs2/ocfs2.h"
> +#include "refcount.h"
>  
>  struct read_whole_context {
>  	char		*buf;
> @@ -325,6 +326,14 @@ static errcode_t ocfs2_file_block_write(ocfs2_cached_inode *ci,
>  	if (v_blkno + wanted_blocks > num_blocks)
>  		wanted_blocks = (uint32_t) (num_blocks - v_blkno);
>  
> +	cluster_begin = ocfs2_blocks_to_clusters(fs, v_blkno);
> +	cluster_end = ocfs2_blocks_to_clusters(fs,
> +					       v_blkno + wanted_blocks - 1);
> +	n_clusters = cluster_end - cluster_begin + 1;
> +	ret = ocfs2_refcount_cow(ci, cluster_begin, n_clusters, UINT_MAX);
> +	if (ret)
> +		return ret;

	I'd say check for feature(REFCOUNT) and dyn_flags&REFCOUNT
before calling ocfs2_refcount_cow().  Why do the NOOP work?

Joel

-- 

"Senator let's be sincere,
 As much as you can."

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127