Revision 475049809977bf3975d78f2d2fd992e19ce2d59e authored by Roel Kluin on 10 March 2009, 19:55:45 UTC, committed by Linus Torvalds on 10 March 2009, 22:55:10 UTC
get_nid_for_pfn() returns int Presumably the (nid < 0) case has never happened. We do know that it is happening on one system while creating a symlink for a memory section so it should also happen on the same system if unregister_mem_sect_under_nodes() were called to remove the same symlink. The test was actually added in response to a problem with an earlier version reported by Yasunori Goto where one or more of the leading pages of a memory section on the 2nd node of one of his systems was uninitialized because I believe they coincided with a memory hole. That earlier version did not ignore uninitialized pages and determined the nid by considering only the 1st page of each memory section. This caused the symlink to the 1st memory section on the 2nd node to be incorrectly created in /sys/devices/system/node/node0 instead of /sys/devices/system/node/node1. The problem was fixed by adding the test to skip over uninitialized pages. I suspect we have not seen any reports of the non-removal of a symlink due to the incorrect declaration of the nid variable in unregister_mem_sect_under_nodes() because - systems where a memory section could have an uninitialized range of leading pages are probably rare. - memory remove is probably not done very frequently on the systems that are capable of demonstrating the problem. - lingering symlink(s) that should have been removed may have simply gone unnoticed. [garyhade@us.ibm.com: wrote changelog] Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Cc: Gary Hade <garyhade@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 1abaf33
output.c
/*
* output.c - Display Output Switch driver
*
* Copyright (C) 2006 Luming Yu <luming.yu@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/module.h>
#include <linux/video_output.h>
#include <linux/err.h>
#include <linux/ctype.h>
MODULE_DESCRIPTION("Display Output Switcher Lowlevel Control Abstraction");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Luming Yu <luming.yu@intel.com>");
static ssize_t video_output_show_state(struct device *dev,
struct device_attribute *attr, char *buf)
{
ssize_t ret_size = 0;
struct output_device *od = to_output_device(dev);
if (od->props)
ret_size = sprintf(buf,"%.8x\n",od->props->get_status(od));
return ret_size;
}
static ssize_t video_output_store_state(struct device *dev,
struct device_attribute *attr,
const char *buf,size_t count)
{
char *endp;
struct output_device *od = to_output_device(dev);
int request_state = simple_strtoul(buf,&endp,0);
size_t size = endp - buf;
if (*endp && isspace(*endp))
size++;
if (size != count)
return -EINVAL;
if (od->props) {
od->request_state = request_state;
od->props->set_state(od);
}
return count;
}
static void video_output_release(struct device *dev)
{
struct output_device *od = to_output_device(dev);
kfree(od);
}
static struct device_attribute video_output_attributes[] = {
__ATTR(state, 0644, video_output_show_state, video_output_store_state),
__ATTR_NULL,
};
static struct class video_output_class = {
.name = "video_output",
.dev_release = video_output_release,
.dev_attrs = video_output_attributes,
};
struct output_device *video_output_register(const char *name,
struct device *dev,
void *devdata,
struct output_properties *op)
{
struct output_device *new_dev;
int ret_code = 0;
new_dev = kzalloc(sizeof(struct output_device),GFP_KERNEL);
if (!new_dev) {
ret_code = -ENOMEM;
goto error_return;
}
new_dev->props = op;
new_dev->dev.class = &video_output_class;
new_dev->dev.parent = dev;
dev_set_name(&new_dev->dev, name);
dev_set_drvdata(&new_dev->dev, devdata);
ret_code = device_register(&new_dev->dev);
if (ret_code) {
kfree(new_dev);
goto error_return;
}
return new_dev;
error_return:
return ERR_PTR(ret_code);
}
EXPORT_SYMBOL(video_output_register);
void video_output_unregister(struct output_device *dev)
{
if (!dev)
return;
device_unregister(&dev->dev);
}
EXPORT_SYMBOL(video_output_unregister);
static void __exit video_output_class_exit(void)
{
class_unregister(&video_output_class);
}
static int __init video_output_class_init(void)
{
return class_register(&video_output_class);
}
postcore_initcall(video_output_class_init);
module_exit(video_output_class_exit);
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