On Wed, 2017-04-05 at 07:41 -0400, Martin K. Petersen wrote:
> +static ssize_t
> +zeroing_mode_store(struct device *dev, struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct scsi_disk *sdkp = to_scsi_disk(dev);
> +
> + if (!capable(CAP_SYS_ADMIN))
> + return -EACCES;
> +
> + if (!strncmp(buf, zeroing_mode[SD_ZERO_WRITE], 20))
> + sdkp->zeroing_mode = SD_ZERO_WRITE;
> + else if (!strncmp(buf, zeroing_mode[SD_ZERO_WS], 20))
> + sdkp->zeroing_mode = SD_ZERO_WS;
> + else if (!strncmp(buf, zeroing_mode[SD_ZERO_WS16_UNMAP], 20))
> + sdkp->zeroing_mode = SD_ZERO_WS16_UNMAP;
> + else if (!strncmp(buf, zeroing_mode[SD_ZERO_WS10_UNMAP], 20))
> + sdkp->zeroing_mode = SD_ZERO_WS10_UNMAP;
> + else
> + return -EINVAL;
> +
> + return count;
> +}
An additional question about this function: if the shell command "echo" is used
without command-line option -n to modify the "zeroing_mode" sysfs attribute then
a newline character will be present in buf. Does the above code handle newline
characters correctly?
Bart.
