Commit 618b2c8d authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Ingo Molnar
Browse files

xen: make sysfs files behave as their names suggest 



1: make "target_kb" only accept and produce a memory size in kilobytes.
2: add a second "target" file which produces output in bytes, and will accept
   memparse input (scaled bytes)

This fixes the rather irritating problem that writing the same value
read back into target_kb would end up shrinking the domain by a factor
of 1024, with generally bad results.

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: "dan.magenheimer@oracle.com" <dan.magenheimer@oracle.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent bf3647c4

drivers/xen/balloon.c

+32 −1
Original line number Diff line number Diff line
@@ -498,7 +498,7 @@ static ssize_t store_target_kb(struct sys_device *dev, 
	if (!capable(CAP_SYS_ADMIN))

		return -EPERM;



	target_bytes = memparse(buf, &endchar);

	target_bytes = simple_strtoull(buf, &endchar, 0) * 1024;



	balloon_set_new_target(target_bytes >> PAGE_SHIFT);
@@ -508,8 +508,39 @@ static ssize_t store_target_kb(struct sys_device *dev, 
static SYSDEV_ATTR(target_kb, S_IRUGO | S_IWUSR,

		   show_target_kb, store_target_kb);





static ssize_t show_target(struct sys_device *dev, struct sysdev_attribute *attr,

			      char *buf)

{

	return sprintf(buf, "%llu\n",

		       (u64)balloon_stats.target_pages << PAGE_SHIFT);

}



static ssize_t store_target(struct sys_device *dev,

			    struct sysdev_attribute *attr,

			    const char *buf,

			    size_t count)

{

	char *endchar;

	unsigned long long target_bytes;



	if (!capable(CAP_SYS_ADMIN))

		return -EPERM;



	target_bytes = memparse(buf, &endchar);



	balloon_set_new_target(target_bytes >> PAGE_SHIFT);



	return count;

}



static SYSDEV_ATTR(target, S_IRUGO | S_IWUSR,

		   show_target, store_target);





static struct sysdev_attribute *balloon_attrs[] = {

	&attr_target_kb,

	&attr_target,

};



static struct attribute *balloon_info_attrs[] = {

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