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 sebastian.capella@linaro.org Cc: Len Brown len.brown@intel.com Cc: Pavel Machek pavel@ucw.cz Cc: "Rafael J. Wysocki" rjw@rjwysocki.net --- 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);
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@linaro.org Cc: Len Brown len.brown@intel.com Cc: Pavel Machek pavel@ucw.cz Cc: "Rafael J. Wysocki" rjw@rjwysocki.net
Acked-by: Pavel Machek pavel@ucw.cz
@@ -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);
Quoting Pavel Machek (2014-02-14 15:47:41)
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 Cc: Len Brown len.brown@intel.com Cc: Pavel Machek pavel@ucw.cz Cc: "Rafael J. Wysocki" rjw@rjwysocki.net
Acked-by: Pavel Machek pavel@ucw.cz
Hi!
Does anyone have any further comments on this? If not, who would take it for 3.15?
Thanks!
Sebastian
linaro-kernel@lists.linaro.org
-
Pavel Machek -
Sebastian Capella