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
hvc_rtas.c
/*
* IBM RTAS driver interface to hvc_console.c
*
* (C) Copyright IBM Corporation 2001-2005
* (C) Copyright Red Hat, Inc. 2005
*
* Author(s): Maximino Augilar <IBM STI Design Center>
* : Ryan S. Arnold <rsa@us.ibm.com>
* : Utz Bacher <utz.bacher@de.ibm.com>
* : David Woodhouse <dwmw2@infradead.org>
*
* inspired by drivers/char/hvc_console.c
* written by Anton Blanchard and Paul Mackerras
*
* 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/console.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <asm/irq.h>
#include <asm/rtas.h>
#include "hvc_console.h"
#define hvc_rtas_cookie 0x67781e15
struct hvc_struct *hvc_rtas_dev;
static int rtascons_put_char_token = RTAS_UNKNOWN_SERVICE;
static int rtascons_get_char_token = RTAS_UNKNOWN_SERVICE;
static inline int hvc_rtas_write_console(uint32_t vtermno, const char *buf,
int count)
{
int i;
for (i = 0; i < count; i++) {
if (rtas_call(rtascons_put_char_token, 1, 1, NULL, buf[i]))
break;
}
return i;
}
static int hvc_rtas_read_console(uint32_t vtermno, char *buf, int count)
{
int i, c;
for (i = 0; i < count; i++) {
if (rtas_call(rtascons_get_char_token, 0, 2, &c))
break;
buf[i] = c;
}
return i;
}
static struct hv_ops hvc_rtas_get_put_ops = {
.get_chars = hvc_rtas_read_console,
.put_chars = hvc_rtas_write_console,
};
static int __init hvc_rtas_init(void)
{
struct hvc_struct *hp;
if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
rtascons_put_char_token = rtas_token("put-term-char");
if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
return -EIO;
if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
rtascons_get_char_token = rtas_token("get-term-char");
if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
return -EIO;
BUG_ON(hvc_rtas_dev);
/* Allocate an hvc_struct for the console device we instantiated
* earlier. Save off hp so that we can return it on exit */
hp = hvc_alloc(hvc_rtas_cookie, NO_IRQ, &hvc_rtas_get_put_ops, 16);
if (IS_ERR(hp))
return PTR_ERR(hp);
hvc_rtas_dev = hp;
return 0;
}
module_init(hvc_rtas_init);
/* This will tear down the tty portion of the driver */
static void __exit hvc_rtas_exit(void)
{
/* Really the fun isn't over until the worker thread breaks down and
* the tty cleans up */
if (hvc_rtas_dev)
hvc_remove(hvc_rtas_dev);
}
module_exit(hvc_rtas_exit);
/* This will happen prior to module init. There is no tty at this time? */
static int __init hvc_rtas_console_init(void)
{
rtascons_put_char_token = rtas_token("put-term-char");
if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
return -EIO;
rtascons_get_char_token = rtas_token("get-term-char");
if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
return -EIO;
hvc_instantiate(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops);
add_preferred_console("hvc", 0, NULL);
return 0;
}
console_initcall(hvc_rtas_console_init);
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