PM / hibernate: use name_to_dev_t to parse resume

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@linaro.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 12 insertions, 10 deletions

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 37170d4dd9a6..f4f2073711d3 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -973,16 +973,20 @@ 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;
 
-        res = MKDEV(maj,min);
-        if (maj != MAJOR(res) || min != MINOR(res))
-                goto out;
+        res = name_to_dev_t(name);
+        kfree(name);
+        if (!res)
+                return -EINVAL;
 
         lock_system_sleep();
         swsusp_resume_device = res;
@@ -990,9 +994,7 @@ static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
         printk(KERN_INFO "PM: Starting manual resume from disk\n");
         noresume = 0;
         software_resume();
-        ret = n;
- out:
-        return ret;
+        return n;
 }
 
 power_attr(resume);