Skip to main content

Browse the archive

Revision be14eb619108fa8b7120eb2c42d66d5f623ae10e authored by Brian King on 10 September 2010, 07:03:21 UTC, committed by Jens Axboe on 10 September 2010, 07:03:21 UTC 
block: Range check cpu in blk_cpu_to_group
 
While testing CPU DLPAR, the following problem was discovered.
We were DLPAR removing the first CPU, which in this case was
logical CPUs 0-3. CPUs 0-2 were already marked offline and
we were in the process of offlining CPU 3. After marking
the CPU inactive and offline in cpu_disable, but before the
cpu was completely idle (cpu_die), we ended up in __make_request
on CPU 3. There we looked at the topology map to see which CPU
to complete the I/O on and found no CPUs in the cpu_sibling_map.
This resulted in the block layer setting the completion cpu
to be NR_CPUS, which then caused an oops when we tried to
complete the I/O.

Fix this by sanity checking the value we return from blk_cpu_to_group
to be a valid cpu value.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
1 parent edce682
Raw File
nonet.c 
/*
 * net/nonet.c
 *
 * Dummy functions to allow us to configure network support entirely
 * out of the kernel.
 *
 * Distributed under the terms of the GNU GPL version 2.
 * Copyright (c) Matthew Wilcox 2003
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>

static int sock_no_open(struct inode *irrelevant, struct file *dontcare)
{
	return -ENXIO;
}

const struct file_operations bad_sock_fops = {
	.owner = THIS_MODULE,
	.open = sock_no_open,
};
back to top