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