linux/mm/failslab.c
Dmitry Monakhov 4c13dd3b48 failslab: add ability to filter slab caches
This patch allow to inject faults only for specific slabs.
In order to preserve default behavior cache filter is off by
default (all caches are faulty).

One may define specific set of slabs like this:
# mark skbuff_head_cache as faulty
echo 1 > /sys/kernel/slab/skbuff_head_cache/failslab
# Turn on cache filter (off by default)
echo 1 > /sys/kernel/debug/failslab/cache-filter
# Turn on fault injection
echo 1 > /sys/kernel/debug/failslab/times
echo 1 > /sys/kernel/debug/failslab/probability

Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-02-26 19:19:39 +02:00

72 lines
1.7 KiB
C

#include <linux/fault-inject.h>
#include <linux/gfp.h>
#include <linux/slab.h>
static struct {
struct fault_attr attr;
u32 ignore_gfp_wait;
int cache_filter;
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
struct dentry *ignore_gfp_wait_file;
struct dentry *cache_filter_file;
#endif
} failslab = {
.attr = FAULT_ATTR_INITIALIZER,
.ignore_gfp_wait = 1,
.cache_filter = 0,
};
bool should_failslab(size_t size, gfp_t gfpflags, unsigned long cache_flags)
{
if (gfpflags & __GFP_NOFAIL)
return false;
if (failslab.ignore_gfp_wait && (gfpflags & __GFP_WAIT))
return false;
if (failslab.cache_filter && !(cache_flags & SLAB_FAILSLAB))
return false;
return should_fail(&failslab.attr, size);
}
static int __init setup_failslab(char *str)
{
return setup_fault_attr(&failslab.attr, str);
}
__setup("failslab=", setup_failslab);
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
static int __init failslab_debugfs_init(void)
{
mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
struct dentry *dir;
int err;
err = init_fault_attr_dentries(&failslab.attr, "failslab");
if (err)
return err;
dir = failslab.attr.dentries.dir;
failslab.ignore_gfp_wait_file =
debugfs_create_bool("ignore-gfp-wait", mode, dir,
&failslab.ignore_gfp_wait);
failslab.cache_filter_file =
debugfs_create_bool("cache-filter", mode, dir,
&failslab.cache_filter);
if (!failslab.ignore_gfp_wait_file ||
!failslab.cache_filter_file) {
err = -ENOMEM;
debugfs_remove(failslab.cache_filter_file);
debugfs_remove(failslab.ignore_gfp_wait_file);
cleanup_fault_attr_dentries(&failslab.attr);
}
return err;
}
late_initcall(failslab_debugfs_init);
#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */