[PATCH]Trival patch for swsusp

[PATCH]Trival patch for swsusp

[Shaohua Li]

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A trival patch for swsusp.


Signed-off-by: Shaohua Li<shaohua.li@intel.com>
---

 linux-2.6.13-rc4-root/kernel/power/disk.c |   10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletion(-)

diff -puN kernel/power/disk.c~swsusp-trival kernel/power/disk.c
--- linux-2.6.13-rc4/kernel/power/disk.c~swsusp-trival	2005-08-01 11:02:47.706757448 +0800
+++ linux-2.6.13-rc4-root/kernel/power/disk.c	2005-08-01 11:11:13.363885880 +0800
@@ -233,9 +233,12 @@ static int software_resume(void)
 {
 	int error;
 
+	down(&pm_sem);
 	if (!swsusp_resume_device) {
-		if (!strlen(resume_file))
+		if (!strlen(resume_file)) {
+			up(&pm_sem);
 			return -ENOENT;
+		}
 		swsusp_resume_device = name_to_dev_t(resume_file);
 		pr_debug("swsusp: Resume From Partition %s\n", resume_file);
 	} else {
@@ -248,6 +251,7 @@ static int software_resume(void)
 		 * FIXME: If noresume is specified, we need to find the partition
 		 * and reset it back to normal swap space.
 		 */
+		up(&pm_sem);
 		return 0;
 	}
 
@@ -284,6 +288,8 @@ static int software_resume(void)
  Cleanup:
 	unprepare_processes();
  Done:
+	/* For success case, the suspend path will release the lock */
+	up(&pm_sem);
 	pr_debug("PM: Resume from disk failed.\n");
 	return 0;
 }
@@ -390,7 +396,9 @@ static ssize_t resume_store(struct subsy
 	if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
 		res = MKDEV(maj,min);
 		if (maj == MAJOR(res) && min == MINOR(res)) {
+			down(&pm_sem);
 			swsusp_resume_device = res;
+			up(&pm_sem);
 			printk("Attempting manual resume\n");
 			noresume = 0;
 			software_resume();
_



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Re: [PATCH]Trival patch for swsusp

[Pavel Machek]

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Hi!

> A trival patch for swsusp.

Aha, it is trying to protect swsusp_resume_device from two users
banging  it from userspace at the same time. Ok, altrough changelog
might be better. ACK. Will you push it or do you want me to?

								Pavel

> Signed-off-by: Shaohua Li<shaohua.li@intel.com>
> ---
> 
>  linux-2.6.13-rc4-root/kernel/power/disk.c |   10 +++++++++-
>  1 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff -puN kernel/power/disk.c~swsusp-trival kernel/power/disk.c
> --- linux-2.6.13-rc4/kernel/power/disk.c~swsusp-trival	2005-08-01 11:02:47.706757448 +0800
> +++ linux-2.6.13-rc4-root/kernel/power/disk.c	2005-08-01 11:11:13.363885880 +0800
> @@ -233,9 +233,12 @@ static int software_resume(void)
>  {
>  	int error;
>  
> +	down(&pm_sem);
>  	if (!swsusp_resume_device) {
> -		if (!strlen(resume_file))
> +		if (!strlen(resume_file)) {
> +			up(&pm_sem);
>  			return -ENOENT;
> +		}
>  		swsusp_resume_device = name_to_dev_t(resume_file);
>  		pr_debug("swsusp: Resume From Partition %s\n", resume_file);
>  	} else {
> @@ -248,6 +251,7 @@ static int software_resume(void)
>  		 * FIXME: If noresume is specified, we need to find the partition
>  		 * and reset it back to normal swap space.
>  		 */
> +		up(&pm_sem);
>  		return 0;
>  	}
>  
> @@ -284,6 +288,8 @@ static int software_resume(void)
>   Cleanup:
>  	unprepare_processes();
>   Done:
> +	/* For success case, the suspend path will release the lock */
> +	up(&pm_sem);
>  	pr_debug("PM: Resume from disk failed.\n");
>  	return 0;
>  }
> @@ -390,7 +396,9 @@ static ssize_t resume_store(struct subsy
>  	if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
>  		res = MKDEV(maj,min);
>  		if (maj == MAJOR(res) && min == MINOR(res)) {
> +			down(&pm_sem);
>  			swsusp_resume_device = res;
> +			up(&pm_sem);
>  			printk("Attempting manual resume\n");
>  			noresume = 0;
>  			software_resume();
> _
> 

-- 
if you have sharp zaurus hardware you don't need... you know my address

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