[linux-2.6-block.git] / mm / failslab.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/fault-inject.h>
#include <linux/error-injection.h>
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include "slab.h"

static struct {
	struct fault_attr attr;
	bool ignore_gfp_reclaim;
	bool cache_filter;
} failslab = {
	.attr = FAULT_ATTR_INITIALIZER,
	.ignore_gfp_reclaim = true,
	.cache_filter = false,
};

int should_failslab(struct kmem_cache *s, gfp_t gfpflags)
{
	int flags = 0;

	/* No fault-injection for bootstrap cache */
	if (unlikely(s == kmem_cache))
		return 0;

	if (gfpflags & __GFP_NOFAIL)
		return 0;

	if (failslab.ignore_gfp_reclaim &&
			(gfpflags & __GFP_DIRECT_RECLAIM))
		return 0;

	if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB))
		return 0;

	/*
	 * In some cases, it expects to specify __GFP_NOWARN
	 * to avoid printing any information(not just a warning),
	 * thus avoiding deadlocks. See commit 6b9dbedbe349 for
	 * details.
	 */
	if (gfpflags & __GFP_NOWARN)
		flags |= FAULT_NOWARN;

	return should_fail_ex(&failslab.attr, s->object_size, flags) ? -ENOMEM : 0;
}
ALLOW_ERROR_INJECTION(should_failslab, ERRNO);

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)
{
	struct dentry *dir;
	umode_t mode = S_IFREG | 0600;

	dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr);
	if (IS_ERR(dir))
		return PTR_ERR(dir);

	debugfs_create_bool("ignore-gfp-wait", mode, dir,
			    &failslab.ignore_gfp_reclaim);
	debugfs_create_bool("cache-filter", mode, dir,
			    &failslab.cache_filter);

	return 0;
}

late_initcall(failslab_debugfs_init);

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
773ff60e	2	#include <linux/fault-inject.h>
a7526fe8	3	#include <linux/error-injection.h>
6ce2082f	4	#include <linux/debugfs.h>
4c13dd3b	5	#include <linux/slab.h>
fab9963a JDB	6	#include <linux/mm.h>
fab9963a JDB	7	#include "slab.h"
773ff60e AM	8
	9	static struct {
	10	struct fault_attr attr;
71baba4b	11	bool ignore_gfp_reclaim;
621a5f7a	12	bool cache_filter;
773ff60e AM	13	} failslab = {
773ff60e AM	14	.attr = FAULT_ATTR_INITIALIZER,
71baba4b	15	.ignore_gfp_reclaim = true,
621a5f7a	16	.cache_filter = false,
773ff60e AM	17	};
773ff60e AM	18
a7526fe8	19	int should_failslab(struct kmem_cache *s, gfp_t gfpflags)
773ff60e	20	{
ea4452de QZ	21	int flags = 0;
ea4452de QZ	22
fab9963a JDB	23	/* No fault-injection for bootstrap cache */
fab9963a JDB	24	if (unlikely(s == kmem_cache))
a7526fe8	25	return 0;
fab9963a	26
773ff60e	27	if (gfpflags & __GFP_NOFAIL)
a7526fe8	28	return 0;
773ff60e	29
a9659476 NB	30	if (failslab.ignore_gfp_reclaim &&
a9659476 NB	31	(gfpflags & __GFP_DIRECT_RECLAIM))
a7526fe8	32	return 0;
773ff60e	33
fab9963a	34	if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB))
a7526fe8	35	return 0;
4c13dd3b	36
ea4452de QZ	37	/*
	38	* In some cases, it expects to specify __GFP_NOWARN
	39	* to avoid printing any information(not just a warning),
	40	* thus avoiding deadlocks. See commit 6b9dbedbe349 for
	41	* details.
	42	*/
3f913fc5	43	if (gfpflags & __GFP_NOWARN)
ea4452de	44	flags \|= FAULT_NOWARN;
3f913fc5	45
a7526fe8	46	return should_fail_ex(&failslab.attr, s->object_size, flags) ? -ENOMEM : 0;
773ff60e	47	}
a7526fe8	48	ALLOW_ERROR_INJECTION(should_failslab, ERRNO);
773ff60e AM	49
	50	static int __init setup_failslab(char *str)
	51	{
	52	return setup_fault_attr(&failslab.attr, str);
	53	}
	54	__setup("failslab=", setup_failslab);
	55
	56	#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
773ff60e AM	57	static int __init failslab_debugfs_init(void)
773ff60e AM	58	{
dd48c085	59	struct dentry *dir;
0825a6f9	60	umode_t mode = S_IFREG \| 0600;
773ff60e	61
dd48c085 AM	62	dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr);
	63	if (IS_ERR(dir))
	64	return PTR_ERR(dir);
773ff60e	65
d9f7979c GKH	66	debugfs_create_bool("ignore-gfp-wait", mode, dir,
	67	&failslab.ignore_gfp_reclaim);
	68	debugfs_create_bool("cache-filter", mode, dir,
	69	&failslab.cache_filter);
4c13dd3b	70
810f09b8	71	return 0;
773ff60e AM	72	}
	73
	74	late_initcall(failslab_debugfs_init);
	75
	76	#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */