[sheepdog] [PATCH v2 3/6] farm: refactor core code

[MORITA Kazutaka]

At Sat, 19 May 2012 23:11:22 +0800,
Liu Yuan wrote:
> 
> From: Liu Yuan <tailai.ly at taobao.com>
> 
> refactor strcut siocb, this makes the code more clean.
> 
> - let sd_store->read/write() use open() internally.
> - remove sd_store->open()/close()
> - add sd_store->exist()
> 
> But now we don't actually have concurrent requests to the same object, because
> upper layer have exclude concurrent access by check_request().
> 
> We'll remove this constaint by later patch set.
> 
> Signed-off-by: Liu Yuan <tailai.ly at taobao.com>
> ---
>  include/util.h       |    5 +-
>  sheep/farm/farm.c    |  190 ++++++++++++++++++++++++++++----------------------
>  sheep/object_cache.c |    5 --
>  sheep/ops.c          |   37 ++--------
>  sheep/recovery.c     |   16 +----
>  sheep/sheep_priv.h   |    6 +-
>  6 files changed, 121 insertions(+), 138 deletions(-)
> 
> diff --git a/include/util.h b/include/util.h
> index 1c32954..10b30d7 100644
> --- a/include/util.h
> +++ b/include/util.h
> @@ -8,6 +8,7 @@
>  
>  #include "bitops.h"
>  #include "list.h"
> +#include "logger.h"
>  
>  #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
>  #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
> @@ -61,8 +62,10 @@ static inline void *zalloc(size_t size)
>  
>  static inline int xlockf(int fd, int cmd, off_t offset, off_t len)
>  {
> -	if (lseek(fd, offset, SEEK_SET) < 0)
> +	if (lseek(fd, offset, SEEK_SET) < 0) {
> +		eprintf("%m\n");
>  		return -1;
> +	}
>  
>  	return lockf(fd, cmd, len);
>  }
> diff --git a/sheep/farm/farm.c b/sheep/farm/farm.c
> index 7912cb7..b5bfa19 100644
> --- a/sheep/farm/farm.c
> +++ b/sheep/farm/farm.c
> @@ -13,9 +13,12 @@
>  
>  #include <dirent.h>
>  #include <pthread.h>
> +#include <linux/limits.h>
>  
>  #include "farm.h"
>  #include "sheep_priv.h"
> +#include "sheepdog_proto.h"
> +#include "sheep.h"
>  
>  char farm_obj_dir[PATH_MAX];
>  char farm_dir[PATH_MAX];
> @@ -67,15 +70,77 @@ err:
>  	return ret;
>  }
>  
> -static int farm_write(uint64_t oid, struct siocb *iocb)
> +static int farm_exist(uint64_t oid)
>  {
> -	ssize_t size = xpwrite(iocb->fd, iocb->buf, iocb->length, iocb->offset);
> +	char path[PATH_MAX];
> +	int flags = def_open_flags, fd;
>  
> -	if (size != iocb->length)
> -		return SD_RES_EIO;
> +	sprintf(path, "%s%016"PRIx64, obj_path, oid);
> +	fd = open(path, flags);
> +	if (fd < 0) {
> +		if (errno != ENOENT)
> +			eprintf("%m\n");
> +		return 0;
> +	}
> +
> +	close(fd);
> +	return 1;
> +}

Is it better to use stat() instead of open() and close()?


> +
> +static int err_to_sderr(uint64_t oid, int err)
> +{
> +	int ret;
> +	if (err == ENOENT) {
> +		struct stat s;
> +
> +		if (stat(obj_path, &s) < 0) {
> +			eprintf("corrupted\n");
> +			ret = SD_RES_EIO;
> +		} else {
> +			dprintf("object %016" PRIx64 " not found locally\n", oid);
> +			ret = SD_RES_NO_OBJ;
> +		}
> +	} else {
> +		eprintf("%m\n");
> +		ret = SD_RES_UNKNOWN;
> +	}
> +	return ret;
> +}
> +
> +static int farm_write(uint64_t oid, struct siocb *iocb, int create)
> +{
> +	int flags = def_open_flags, fd, ret;

ret must be initialized with SD_RES_SUCCESS.

Other parts of this series look good to me.

Thanks,

Kazutaka