Re: [dpdk-dev] [PATCH v2 1/1] fbarray: get fbarrays from containerized secondary

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

On 16-Apr-19 4:43 AM, ogawa.yasufumi@lab.ntt.co.jp wrote:
> From: Yasufumi Ogawa <ogawa.yasufumi@lab.ntt.co.jp>
> 
> In secondary_msl_create_walk(), it creates a file for fbarrays with its
> PID for reserving unique name among secondary processes. However, it
> does not work if secondary is run as app container because each of
> containerized secondary has PID 1. To reserve unique name, use hostname
> instead of PID if the value is 1.
> 
> Cc: stable@dpdk.org
> 
> Signed-off-by: Yasufumi Ogawa <ogawa.yasufumi@lab.ntt.co.jp>
> ---

I'm not too well versed in containers - is this hostname 1) always set, 
and 2) always unique?

<snip>

> +	if (getpid() == 1) {
> +		FILE *hn_fp;
> +		hn_fp = fopen("/etc/hostname", "r");
> +		if (hn_fp == NULL) {
> +			RTE_LOG(ERR, EAL,
> +				"Cannot open '/etc/hostname' for secondary\n");
> +			return -1;
> +		}
> +
> +		/* with docker, /etc/hostname just has one entry of hostname */
> +		if (fscanf(hn_fp, "%s", proc_id) == EOF)
> +			return -1;

Wouldn't an error in fscanf() leak the file handle? I think you need to 
fclose() before checking the result.

> +		fclose(hn_fp);
> +	} else
> +		sprintf(proc_id, "%d", (int)getpid());
> +
> +	snprintf(name, RTE_FBARRAY_NAME_LEN, "%s_%s",
> +			primary_msl->memseg_arr.name, proc_id);
>   
>   	ret = rte_fbarray_init(&local_msl->memseg_arr, name,
>   		primary_msl->memseg_arr.len,
> 


-- 
Thanks,
Anatoly