[Sheepdog] [PATCH] store: use O_DIRECT IO for backend store

[Liu Yuan]

On 04/02/2012 05:49 PM, Liu Yuan wrote:

> From: Liu Yuan <tailai.ly at taobao.com>
> 
> Backend store don't need page cache, by this way we make room of memory for
> object cache to maximize its performance.
> 
> Signed-off-by: Liu Yuan <tailai.ly at taobao.com>
> ---
>  sheep/farm/farm.c    |    9 ++++++---
>  sheep/simple_store.c |    6 +++---
>  2 files changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/sheep/farm/farm.c b/sheep/farm/farm.c
> index fa008ea..7a9e9e5 100644
> --- a/sheep/farm/farm.c
> +++ b/sheep/farm/farm.c
> @@ -20,7 +20,7 @@
>  char farm_obj_dir[PATH_MAX];
>  char farm_dir[PATH_MAX];
>  
> -static int def_open_flags = O_DSYNC | O_RDWR;
> +static int def_open_flags = O_DIRECT | O_DSYNC | O_RDWR;
>  extern char *obj_path;
>  extern mode_t def_fmode;
>  extern mode_t def_dmode;
> @@ -153,8 +153,8 @@ static int farm_open(uint64_t oid, struct siocb *iocb, int create)
>  	if (iocb->epoch < sys->epoch)
>  		goto out;
>  
> -	if (sys->use_directio && is_data_obj(oid))
> -		flags |= O_DIRECT;
> +	if (is_vdi_obj(oid))
> +		flags &= ~O_DIRECT;
>  
>  	if (create)
>  		flags |= O_CREAT | O_TRUNC;
> @@ -397,6 +397,9 @@ static int farm_atomic_put(uint64_t oid, struct siocb *iocb)
>  	snprintf(path, sizeof(path), "%s%016" PRIx64, obj_path, oid);
>  	snprintf(tmp_path, sizeof(tmp_path), "%s%016" PRIx64 ".tmp",
>  		 obj_path, oid);
> +
> +	if (is_vdi_obj(oid))
> +		flags &= ~O_DIRECT;
>  	fd = open(tmp_path, flags, def_fmode);
>  	if (fd < 0) {
>  		eprintf("failed to open %s: %m\n", tmp_path);
> diff --git a/sheep/simple_store.c b/sheep/simple_store.c
> index dd3c62d..f1077f7 100644
> --- a/sheep/simple_store.c
> +++ b/sheep/simple_store.c
> @@ -30,7 +30,7 @@ extern char *obj_path;
>  
>  extern mode_t def_fmode;
>  
> -static int def_store_flags = O_DSYNC | O_RDWR;
> +static int def_store_flags = O_DIRECT | O_DSYNC | O_RDWR;
>  
>  static int simple_store_write(uint64_t oid, struct siocb *iocb);
>  
> @@ -108,8 +108,8 @@ static int simple_store_open(uint64_t oid, struct siocb *iocb, int create)
>  	int ret;
>  	int flags = def_store_flags;
>  
> -	if (sys->use_directio && is_data_obj(oid))
> -		flags |= O_DIRECT;
> +	if (is_vdi_obj(oid))
> +		flags &= ~O_DIRECT;
>  
>  	if (create)
>  		flags |= O_CREAT | O_TRUNC;


Applied.

Thanks,
Yuan