Re: [PATCH v9] PM / Hibernate: use name_to_dev_t to parse resume

From: Pavel Machek
Date: Fri Feb 14 2014 - 18:47:56 EST


Hi!

> Use the name_to_dev_t call to parse the device name echo'd to
> to /sys/power/resume. This imitates the method used in hibernate.c
> in software_resume, and allows the resume partition to be specified
> using other equivalent device formats as well. By allowing
> /sys/debug/resume to accept the same syntax as the resume=device
> parameter, we can parse the resume=device in the init script and
> use the resume device directly from the kernel command line.
>
> Signed-off-by: Sebastian Capella <sebastian.capella@xxxxxxxxxx>
> Cc: Len Brown <len.brown@xxxxxxxxx>
> Cc: Pavel Machek <pavel@xxxxxx>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>

Acked-by: Pavel Machek <pavel@xxxxxx>

> @@ -972,16 +972,20 @@ static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
> static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
> const char *buf, size_t n)
> {
> - unsigned int maj, min;
> dev_t res;
> - int ret = -EINVAL;
> + int len = n;
> + char *name;
>
> - if (sscanf(buf, "%u:%u", &maj, &min) != 2)
> - goto out;
> + if (len && buf[len-1] == '\n')
> + len--;
> + name = kstrndup(buf, len, GFP_KERNEL);
> + if (!name)
> + return -ENOMEM;

And yes, it seems to do right thing even if "\n" is passed to it.

> - res = MKDEV(maj,min);
> - if (maj != MAJOR(res) || min != MINOR(res))
> - goto out;
> + res = name_to_dev_t(name);
> + kfree(name);

--
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