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

From: Sebastian Capella
Date: Fri Feb 14 2014 - 17:53:24 EST


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>
---
kernel/power/hibernate.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 0121dab..a5f702a 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -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;

- 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;
@@ -989,9 +993,7 @@ 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);
--
1.7.9.5

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