[sheepdog] [PATCH v6 4/7] sheep: use new journal API for config file

[MORITA Kazutaka]

At Mon,  8 Apr 2013 14:04:58 +0800,
Liu Yuan wrote:
> 
> From: Liu Yuan <tailai.ly at taobao.com>
> 
> Signed-off-by: Liu Yuan <tailai.ly at taobao.com>
> ---
>  sheep/config.c     |   33 ++++++++++++++++++---------------
>  sheep/sheep.c      |   26 +++++++++++++++-----------
>  sheep/sheep_priv.h |    3 ++-
>  sheep/store.c      |    4 +---
>  4 files changed, 36 insertions(+), 30 deletions(-)
> 
> diff --git a/sheep/config.c b/sheep/config.c
> index 63cfe87..14da875 100644
> --- a/sheep/config.c
> +++ b/sheep/config.c
> @@ -36,7 +36,14 @@ char *config_path;
>  static int write_config(void)
>  {
>  	int fd, ret;
> -	void *jd;
> +
> +	if (uatomic_is_true(&sys->use_journal) &&
> +	    journal_write_config((char *)&config, sizeof(config))
> +	    != SD_RES_SUCCESS) {
> +		sd_eprintf("turn off journaling");
> +		uatomic_set_false(&sys->use_journal);
> +		sync();
> +	}
>  
>  	fd = open(config_path, O_DSYNC | O_WRONLY | O_CREAT, def_fmode);
>  	if (fd < 0) {
> @@ -44,32 +51,20 @@ static int write_config(void)
>  		return SD_RES_EIO;
>  	}
>  
> -	jd = jrnl_begin(&config, sizeof(config), 0, config_path, jrnl_path);
> -	if (!jd) {
> -		sd_eprintf("failed to write config data to journal, %m");
> -		ret = SD_RES_EIO;
> -		goto out;
> -	}
>  	ret = xwrite(fd, &config, sizeof(config));
>  	if (ret != sizeof(config)) {
>  		sd_eprintf("failed to write config data, %m");
>  		ret = SD_RES_EIO;
>  	} else
>  		ret = SD_RES_SUCCESS;
> -
> -	jrnl_end(jd);
> -out:
>  	close(fd);
>  
>  	return ret;
>  }
>  
> -int init_config_path(const char *base_path)
> +int init_config_file(void)
>  {
> -	int fd, ret, len = strlen(base_path) + strlen(CONFIG_PATH) + 1;
> -
> -	config_path = xzalloc(len);
> -	snprintf(config_path, len, "%s" CONFIG_PATH, base_path);
> +	int fd, ret;
>  
>  	fd = open(config_path, O_RDONLY);
>  	if (fd < 0) {
> @@ -126,6 +121,14 @@ create:
>  	return 0;
>  }
>  
> +void init_config_path(const char *base_path)
> +{
> +	int len = strlen(base_path) + strlen(CONFIG_PATH) + 1;
> +
> +	config_path = xzalloc(len);
> +	snprintf(config_path, len, "%s" CONFIG_PATH, base_path);
> +}
> +
>  int set_cluster_ctime(uint64_t ct)
>  {
>  	config.ctime = ct;
> diff --git a/sheep/sheep.c b/sheep/sheep.c
> index 4fa7d58..cda8493 100644
> --- a/sheep/sheep.c
> +++ b/sheep/sheep.c
> @@ -597,6 +597,21 @@ int main(int argc, char **argv)
>  	if (ret)
>  		exit(1);
>  
> +	/* We should init journal file before config file init */
> +	if (uatomic_is_true(&sys->use_journal)) {
> +		if (!strlen(jpath))
> +			/* internal journal */
> +			memcpy(jpath, dir, strlen(dir));
> +		sd_dprintf("%s, %zu, %d", jpath, jsize, jskip);
> +		ret = journal_file_init(jpath, jsize, jskip);
> +		if (ret)
> +			exit(1);
> +	}
> +
> +	ret = init_config_file();
> +	if (ret)
> +		exit(1);
> +
>  	ret = create_listen_port(bindaddr, port);
>  	if (ret)
>  		exit(1);
> @@ -625,17 +640,6 @@ int main(int argc, char **argv)
>  		exit(1);
>  	}
>  
> -	/* We should init journal file before backend init */
> -	if (uatomic_is_true(&sys->use_journal)) {
> -		if (!strlen(jpath))
> -			/* internal journal */
> -			memcpy(jpath, dir, strlen(dir));
> -		sd_dprintf("%s, %zu, %d", jpath, jsize, jskip);
> -		ret = journal_file_init(jpath, jsize, jskip);
> -		if (ret)
> -			exit(1);
> -	}
> -
>  	/*
>  	 * After this function, we are multi-threaded.
>  	 *

I've found that we cannot pass tests/047 with -md because of this
change.  We have to call init_disk_space() before journal_file_init().
Otherwise, sheep cannot replay journal entries correctly since
md_disks are setup in md_init_space().

However, we read the config file in init_disk_space(), so
journal_file_init() must be called before init_disk_space() in that
sense.  I think we need to give up using journal against the config
file, or store a vdisk index to the journal descriptor so that we can
get a correct object path.

Thanks,

Kazutaka