[dm-devel] [PATCH] multipath: fix scsi timeout code

[Hannes Reinecke]

On 12/19/2011 11:19 PM, Benjamin Marzinski wrote:
> sysfs_attr_set_value() returns the amount written on on success, or -1 on
> failure.  sysfs_setc_scsi_tmo() was checking if the return was nonzero, and
> failing if it was. This meant that it always failed out silently after writing
> the first value. I've changed the check, and added some error messages.  I also
> made sysfs_attr_set_value return -1 for all errors.
> 
> Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
> ---
>  libmultipath/discovery.c |   11 +++++++++--
>  libmultipath/sysfs.c     |    2 +-
>  2 files changed, 10 insertions(+), 3 deletions(-)
> 
> Index: multipath-tools-111111/libmultipath/discovery.c
> ===================================================================
> --- multipath-tools-111111.orig/libmultipath/discovery.c
> +++ multipath-tools-111111/libmultipath/discovery.c
> @@ -316,8 +316,11 @@ sysfs_set_scsi_tmo (struct multipath *mp
>  		if (mpp->dev_loss){
>  			snprintf(value, 11, "%u", mpp->dev_loss);
>  			if (sysfs_attr_set_value(attr_path, "dev_loss_tmo",
> -						 value, 11))
> +						 value, 11) < 0) {
> +				condlog(0, "%s failed to set %s/dev_loss_tmo",
> +					mpp->alias, attr_path);
>  				return 1;
> +			}
>  		}
>  		if (mpp->fast_io_fail){
>  			if (mpp->fast_io_fail == -1)
> @@ -325,8 +328,12 @@ sysfs_set_scsi_tmo (struct multipath *mp
>  			else
>  				snprintf(value, 11, "%u", mpp->fast_io_fail);
>  			if (sysfs_attr_set_value(attr_path, "fast_io_fail_tmo",
> -						 value, 11))
> +						 value, 11) < 0) {
> +				condlog(0,
> +					"%s failed to set %s/fast_io_fail_tmo", 
> +					mpp->alias, attr_path);
>  				return 1;
> +			}
>  		}
>  	}
>  	return 0;
> Index: multipath-tools-111111/libmultipath/sysfs.c
> ===================================================================
> --- multipath-tools-111111.orig/libmultipath/sysfs.c
> +++ multipath-tools-111111/libmultipath/sysfs.c
> @@ -351,7 +351,7 @@ ssize_t sysfs_attr_set_value(const char
>  	char path_full[PATH_SIZE];
>  	struct stat statbuf;
>  	int fd;
> -	ssize_t size = 0;
> +	ssize_t size = -1;
>  	size_t sysfs_len;
>  
>  	if (!attr_name || !value || !value_len)
> 
Ah. Good point. Thanks.

Acked-by: Hannes Reinecke <hare at suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare at suse.de			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)