Patchset related to hibernation resume:
- enhancement to make the use of an existing resume file more general
Patch is based on the 3.13 tag. This was tested on a Beaglebone black
with partial hibernation support, also compiled for x86_64.
[PATCH v9 1/1] PM / Hibernate: use name_to_dev_t to parse resume
kernel/power/hibernate.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
Use name_to_dev_t to parse the /sys/power/resume file making the
syntax more flexible. It supports the previous use syntax
and additionally can support other formats such as
/dev/devicenode and UUID= formats.
By changing /sys/debug/resume to accept the same syntax as
the resume=device parameter, we can parse the resume=device
in the initrd init script and use the resume device directly
from the kernel command line.
Changes in v9:
--------------
* Dropped util changes based on feedback
* Reverted to handling newlines in resume_store
Changes in v8:
--------------
* Dropped cleanup checkpatch warnings in hibernate.c file
* Review comments for more compact checking in hibernate.c
Changes in v7:
--------------
* Switch to trim only one trailing newline if present using kstrdup_trimnl
* remove kstrimdup patch
* add kstrdup_trimnl patch
* Add clean up patch for kernel/power/hibernate.c checkpatch warnings
Changes in v6:
--------------
* Revert tricky / confusing while loop indexing
Changes in v5:
--------------
* Change kstrimdup to minimize allocated memory. Now allocates only
the memory needed for the string instead of using strim.
Changes in v4:
--------------
* Dropped name_to_dev_t rework in favor of adding kstrimdup
* adjusted resume_store
Changes in v3:
--------------
* Dropped documentation patch as it went in through trivial
* Added patch for name_to_dev_t to support directly parsing userspace
buffer
Changes in v2:
--------------
* Added check for null return of kstrndup in hibernate.c
Thanks,
Sebastian
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 <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
---
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
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 <[email protected]>
> Cc: Len Brown <[email protected]>
> Cc: Pavel Machek <[email protected]>
> Cc: "Rafael J. Wysocki" <[email protected]>
Acked-by: Pavel Machek <[email protected]>
> @@ -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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(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html