[PATCH] PM / Hibernate : Use get_gendisk to verify partition if resume_file is integer format

[PATCH] PM / Hibernate : Use get_gendisk to verify partition if resume_file is integer format

[Minho Ban]

Sometimes resume= parameter comes in integer style (e.g. major:minor) then
name_to_dev_t can not detect partition properly. (especially async device like
usb, mmc)
This patch calls get_gendisk if resumewait is true and resume_file is in integer
format.

Signed-off-by: Minho Ban <mhban@samsung.com>
---
 Documentation/kernel-parameters.txt |    2 ++
 kernel/power/hibernate.c            |   13 +++++++++++++
 2 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index c1601e5..5900b49 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2372,6 +2372,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
 	resume=		[SWSUSP]
 			Specify the partition device for software suspend
+			Format:
+			{/dev/<dev> | PARTUUID=<uuid> | <int>:<int> | <hex>}
 
 	resume_offset=	[SWSUSP]
 			Specify the offset from the beginning of the partition
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index e09dfbf..8b53db3 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -25,6 +25,8 @@
 #include <linux/freezer.h>
 #include <linux/gfp.h>
 #include <linux/syscore_ops.h>
+#include <linux/ctype.h>
+#include <linux/genhd.h>
 #include <scsi/scsi_scan.h>
 
 #include "power.h"
@@ -722,6 +724,17 @@ static int software_resume(void)
 
 	/* Check if the device is there */
 	swsusp_resume_device = name_to_dev_t(resume_file);
+
+	/*
+	 * name_to_dev_t is ineffective to verify parition if resume_file is in
+	 * integer format. (e.g. major:minor)
+	 */
+	if (isdigit(resume_file[0]) && resume_wait) {
+		int partno;
+		while (!get_gendisk(swsusp_resume_device, &partno))
+			msleep(10);
+	}
+
 	if (!swsusp_resume_device) {
 		/*
 		 * Some device discovery might still be in progress; we need
-- 
1.7.5.4

Re: [PATCH] PM / Hibernate : Use get_gendisk to verify partition if resume_file is integer format

[Rafael J. Wysocki]

On Wednesday, May 09, 2012, Minho Ban wrote:
> Sometimes resume= parameter comes in integer style (e.g. major:minor) then
> name_to_dev_t can not detect partition properly. (especially async device like
> usb, mmc)
> This patch calls get_gendisk if resumewait is true and resume_file is in integer
> format.
> 
> Signed-off-by: Minho Ban <mhban@samsung.com>
> ---
>  Documentation/kernel-parameters.txt |    2 ++
>  kernel/power/hibernate.c            |   13 +++++++++++++
>  2 files changed, 15 insertions(+), 0 deletions(-)
> 
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index c1601e5..5900b49 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -2372,6 +2372,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
>  
>  	resume=		[SWSUSP]
>  			Specify the partition device for software suspend
> +			Format:
> +			{/dev/<dev> | PARTUUID=<uuid> | <int>:<int> | <hex>}
>  
>  	resume_offset=	[SWSUSP]
>  			Specify the offset from the beginning of the partition
> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
> index e09dfbf..8b53db3 100644
> --- a/kernel/power/hibernate.c
> +++ b/kernel/power/hibernate.c
> @@ -25,6 +25,8 @@
>  #include <linux/freezer.h>
>  #include <linux/gfp.h>
>  #include <linux/syscore_ops.h>
> +#include <linux/ctype.h>
> +#include <linux/genhd.h>
>  #include <scsi/scsi_scan.h>
>  
>  #include "power.h"
> @@ -722,6 +724,17 @@ static int software_resume(void)
>  
>  	/* Check if the device is there */
>  	swsusp_resume_device = name_to_dev_t(resume_file);
> +
> +	/*
> +	 * name_to_dev_t is ineffective to verify parition if resume_file is in
> +	 * integer format. (e.g. major:minor)
> +	 */
> +	if (isdigit(resume_file[0]) && resume_wait) {
> +		int partno;
> +		while (!get_gendisk(swsusp_resume_device, &partno))
> +			msleep(10);
> +	}

Hmm.  Wouldn't it be better to do:

	if (isdigit(resume_file[0]) && resume_wait) {
		int partno;
		while (!get_gendisk(swsusp_resume_device, &partno))
			msleep(10);
	} else {
		swsusp_resume_device = name_to_dev_t(resume_file);
	}

?

Your new code will overwrite whatever swsusp_resume_device is set to by the
preceding statement anyway.

> +
>  	if (!swsusp_resume_device) {
>  		/*
>  		 * Some device discovery might still be in progress; we need
> 

Thanks,
Rafael

Re: [PATCH] PM / Hibernate : Use get_gendisk to verify partition if resume_file is integer format

[Minho Ban]

On 05/13/2012 06:39 AM, Rafael J. Wysocki wrote:
> On Wednesday, May 09, 2012, Minho Ban wrote:
>>  	/* Check if the device is there */
>>  	swsusp_resume_device = name_to_dev_t(resume_file);
>> +
>> +	/*
>> +	 * name_to_dev_t is ineffective to verify parition if resume_file is in
>> +	 * integer format. (e.g. major:minor)
>> +	 */
>> +	if (isdigit(resume_file[0]) && resume_wait) {
>> +		int partno;
>> +		while (!get_gendisk(swsusp_resume_device, &partno))
>> +			msleep(10);
>> +	}
> 
> Hmm.  Wouldn't it be better to do:
> 
> 	if (isdigit(resume_file[0]) && resume_wait) {
> 		int partno;
> 		while (!get_gendisk(swsusp_resume_device, &partno))
> 			msleep(10);
> 	} else {
> 		swsusp_resume_device = name_to_dev_t(resume_file);
> 	}
> 
> ?

Do you want name_to_dev_t to be called again?  If not, swsusp_resume_device parameter 
in get_gendisk can not be used because it is not initialized yet.

> 
> Your new code will overwrite whatever swsusp_resume_device is set to by the
> preceding statement anyway.
> 

Sorry, I don't understand what will be overwritten by the new code. It would be very 
much appreciated if you point it again.

Regards,
Minho Ban

Re: [PATCH] PM / Hibernate : Use get_gendisk to verify partition if resume_file is integer format

[Rafael J. Wysocki]

On Monday, May 14, 2012, Minho Ban wrote:
> On 05/13/2012 06:39 AM, Rafael J. Wysocki wrote:
> > On Wednesday, May 09, 2012, Minho Ban wrote:
> >>  	/* Check if the device is there */
> >>  	swsusp_resume_device = name_to_dev_t(resume_file);
> >> +
> >> +	/*
> >> +	 * name_to_dev_t is ineffective to verify parition if resume_file is in
> >> +	 * integer format. (e.g. major:minor)
> >> +	 */
> >> +	if (isdigit(resume_file[0]) && resume_wait) {
> >> +		int partno;
> >> +		while (!get_gendisk(swsusp_resume_device, &partno))
> >> +			msleep(10);
> >> +	}
> > 
> > Hmm.  Wouldn't it be better to do:
> > 
> > 	if (isdigit(resume_file[0]) && resume_wait) {
> > 		int partno;
> > 		while (!get_gendisk(swsusp_resume_device, &partno))
> > 			msleep(10);
> > 	} else {
> > 		swsusp_resume_device = name_to_dev_t(resume_file);
> > 	}
> > 
> > ?
> 
> Do you want name_to_dev_t to be called again?  If not, swsusp_resume_device parameter 
> in get_gendisk can not be used because it is not initialized yet.

Ah, OK, I didn't notice that.

I think I can take the patch for v3.5 as is.

Thanks,
Rafael