Re: [PATCH 18/22] ARM: i.MX: bbu: Adjust error code check for pwrite()

From: Sascha Hauer <s.hauer@pengutronix.de>
To: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH 18/22] ARM: i.MX: bbu: Adjust error code check for pwrite()
Date: Wed, 22 Aug 2018 09:01:08 +0200	[thread overview]
Message-ID: <20180822070108.balrgkhkrurrmxo2@pengutronix.de> (raw)
In-Reply-To: <20180821062603.17393-19-andrew.smirnov@gmail.com>

On Mon, Aug 20, 2018 at 11:25:59PM -0700, Andrey Smirnov wrote:
> Pwrite() will return the amount bytes written or negative error code
> on success, so we need to do two things with it:
> 
>     1. Check it against "image_len" to make sure we actually wrote all
>        of the data
> 
>     2. Set it to zero in case of success, since that is what code in
>        barebox_update() expects to happen
> 
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> ---
>  arch/arm/mach-imx/imx-bbu-internal.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/mach-imx/imx-bbu-internal.c b/arch/arm/mach-imx/imx-bbu-internal.c
> index d83eb972c..70af5ef84 100644
> --- a/arch/arm/mach-imx/imx-bbu-internal.c
> +++ b/arch/arm/mach-imx/imx-bbu-internal.c
> @@ -86,6 +86,7 @@ static int imx_bbu_write_device(struct imx_internal_bbu_handler *imx_handler,
>  		const void *buf, int image_len)
>  {
>  	int fd, ret, offset = 0;
> +	bool partial_write;
>  
>  	fd = open(devicefile, O_RDWR | O_CREAT);
>  	if (fd < 0)
> @@ -117,8 +118,14 @@ static int imx_bbu_write_device(struct imx_internal_bbu_handler *imx_handler,
>  	}
>  
>  	ret = pwrite(fd, buf, image_len, offset);
> -	if (ret < 0)
> +	partial_write = ret > 0 && ret != image_len;
> +	if (ret < 0 || partial_write) {
> +		ret = partial_write ? -EIO : ret;
> +
> +		pr_err("writing to %s failed with %s\n", devicefile,
> +		       strerror(-ret));
>  		goto err_close;

Do we need a pwrite_full analog to write_full?

Sascha

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