Revision 94e18007688a13e5da1a2f1b7f52f15cc56c9f5e authored by Jeff Layton on 04 March 2013, 20:18:25 UTC, committed by Steve French on 07 March 2013, 01:03:57 UTC
We had a recent fix to fix the release of pagecache pages when cifs_writev_requeue writes fail. Unfortunately, it releases the page before trying to unlock it. At that point, the page might be gone by the time the unlock comes in. Unlock the page first before checking the value of "rc", and only then end writeback and release the pages. The page lock isn't required for any of those operations so this should be safe. Reported-by: Anton Altaparmakov <aia21@cam.ac.uk> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
1 parent 2518964
mm_init.c
/*
* mm_init.c - Memory initialisation verification and debugging
*
* Copyright 2008 IBM Corporation, 2008
* Author Mel Gorman <mel@csn.ul.ie>
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/kobject.h>
#include <linux/export.h>
#include "internal.h"
#ifdef CONFIG_DEBUG_MEMORY_INIT
int mminit_loglevel;
#ifndef SECTIONS_SHIFT
#define SECTIONS_SHIFT 0
#endif
/* The zonelists are simply reported, validation is manual. */
void mminit_verify_zonelist(void)
{
int nid;
if (mminit_loglevel < MMINIT_VERIFY)
return;
for_each_online_node(nid) {
pg_data_t *pgdat = NODE_DATA(nid);
struct zone *zone;
struct zoneref *z;
struct zonelist *zonelist;
int i, listid, zoneid;
BUG_ON(MAX_ZONELISTS > 2);
for (i = 0; i < MAX_ZONELISTS * MAX_NR_ZONES; i++) {
/* Identify the zone and nodelist */
zoneid = i % MAX_NR_ZONES;
listid = i / MAX_NR_ZONES;
zonelist = &pgdat->node_zonelists[listid];
zone = &pgdat->node_zones[zoneid];
if (!populated_zone(zone))
continue;
/* Print information about the zonelist */
printk(KERN_DEBUG "mminit::zonelist %s %d:%s = ",
listid > 0 ? "thisnode" : "general", nid,
zone->name);
/* Iterate the zonelist */
for_each_zone_zonelist(zone, z, zonelist, zoneid) {
#ifdef CONFIG_NUMA
printk(KERN_CONT "%d:%s ",
zone->node, zone->name);
#else
printk(KERN_CONT "0:%s ", zone->name);
#endif /* CONFIG_NUMA */
}
printk(KERN_CONT "\n");
}
}
}
void __init mminit_verify_pageflags_layout(void)
{
int shift, width;
unsigned long or_mask, add_mask;
shift = 8 * sizeof(unsigned long);
width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH - LAST_NID_SHIFT;
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
"Section %d Node %d Zone %d Lastnid %d Flags %d\n",
SECTIONS_WIDTH,
NODES_WIDTH,
ZONES_WIDTH,
LAST_NID_WIDTH,
NR_PAGEFLAGS);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
"Section %d Node %d Zone %d Lastnid %d\n",
SECTIONS_SHIFT,
NODES_SHIFT,
ZONES_SHIFT,
LAST_NID_SHIFT);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_pgshifts",
"Section %lu Node %lu Zone %lu Lastnid %lu\n",
(unsigned long)SECTIONS_PGSHIFT,
(unsigned long)NODES_PGSHIFT,
(unsigned long)ZONES_PGSHIFT,
(unsigned long)LAST_NID_PGSHIFT);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodezoneid",
"Node/Zone ID: %lu -> %lu\n",
(unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT),
(unsigned long)ZONEID_PGOFF);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
"location: %d -> %d layout %d -> %d unused %d -> %d page-flags\n",
shift, width, width, NR_PAGEFLAGS, NR_PAGEFLAGS, 0);
#ifdef NODE_NOT_IN_PAGE_FLAGS
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
"Node not in page flags");
#endif
#ifdef LAST_NID_NOT_IN_PAGE_FLAGS
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
"Last nid not in page flags");
#endif
if (SECTIONS_WIDTH) {
shift -= SECTIONS_WIDTH;
BUG_ON(shift != SECTIONS_PGSHIFT);
}
if (NODES_WIDTH) {
shift -= NODES_WIDTH;
BUG_ON(shift != NODES_PGSHIFT);
}
if (ZONES_WIDTH) {
shift -= ZONES_WIDTH;
BUG_ON(shift != ZONES_PGSHIFT);
}
/* Check for bitmask overlaps */
or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
(NODES_MASK << NODES_PGSHIFT) |
(SECTIONS_MASK << SECTIONS_PGSHIFT);
add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
(NODES_MASK << NODES_PGSHIFT) +
(SECTIONS_MASK << SECTIONS_PGSHIFT);
BUG_ON(or_mask != add_mask);
}
void __meminit mminit_verify_page_links(struct page *page, enum zone_type zone,
unsigned long nid, unsigned long pfn)
{
BUG_ON(page_to_nid(page) != nid);
BUG_ON(page_zonenum(page) != zone);
BUG_ON(page_to_pfn(page) != pfn);
}
static __init int set_mminit_loglevel(char *str)
{
get_option(&str, &mminit_loglevel);
return 0;
}
early_param("mminit_loglevel", set_mminit_loglevel);
#endif /* CONFIG_DEBUG_MEMORY_INIT */
struct kobject *mm_kobj;
EXPORT_SYMBOL_GPL(mm_kobj);
static int __init mm_sysfs_init(void)
{
mm_kobj = kobject_create_and_add("mm", kernel_kobj);
if (!mm_kobj)
return -ENOMEM;
return 0;
}
__initcall(mm_sysfs_init);
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