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Revision a247c3a97a0216b18a46243eda26081f1928ec37 authored by Andrea Arcangeli on 22 September 2010, 20:05:12 UTC, committed by Linus Torvalds on 23 September 2010, 00:22:39 UTC 
rmap: fix walk during fork
 
The below bug in fork led to the rmap walk finding the parent huge-pmd
twice instead of just once, because the anon_vma_chain objects of the
child vma still point to the vma->vm_mm of the parent.

The patch fixes it by making the rmap walk accurate during fork.  It's not
a big deal normally but it worth being accurate considering the cost is
the same.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Johannes Weiner <jweiner@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent df08cdc
Raw File
init.c 
/* -*- linux-c -*- --------------------------------------------------------- *
 *
 * linux/fs/autofs/init.c
 *
 *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
 *
 * This file is part of the Linux kernel and is made available under
 * the terms of the GNU General Public License, version 2, or at your
 * option, any later version, incorporated herein by reference.
 *
 * ------------------------------------------------------------------------- */

#include <linux/module.h>
#include <linux/init.h>
#include "autofs_i.h"

static int autofs_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
	return get_sb_nodev(fs_type, flags, data, autofs_fill_super, mnt);
}

static struct file_system_type autofs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "autofs",
	.get_sb		= autofs_get_sb,
	.kill_sb	= autofs_kill_sb,
};

static int __init init_autofs_fs(void)
{
	return register_filesystem(&autofs_fs_type);
}

static void __exit exit_autofs_fs(void)
{
	unregister_filesystem(&autofs_fs_type);
}

module_init(init_autofs_fs);
module_exit(exit_autofs_fs);

#ifdef DEBUG
void autofs_say(const char *name, int len)
{
	printk("(%d: ", len);
	while ( len-- )
		printk("%c", *name++);
	printk(")\n");
}
#endif
MODULE_LICENSE("GPL");
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