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

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 <[email protected]>

---
 Documentation/kernel-parameters.txt |    2 ++
 kernel/power/hibernate.c            |   13 +++++++++++++
 2 files changed, 15 insertions(+), 0 deletions(-)

Documentation/kernel-parameters.txt +2 -0

index c1601e5..5900b49 100644
@@ -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

kernel/power/hibernate.c +2 -0

index e09dfbf..8b53db3 100644
@@ -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);

kernel/power/hibernate.c static int software_resume(void) · line 736

Quoted 12 lines · Minho Ban

kernel/power/hibernate.c +10 -0

 	/* 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.

Quoted 24 lines · Rafael J. Wysocki

kernel/power/hibernate.c static int software_resume(void) · line 736

Quoted 12 lines · Minho Ban

kernel/power/hibernate.c +10 -0

 	/* 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);
	}

Quoted 1 line

?

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.