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

// SPDX-License-Identifier: GPL-2.0
#include <linux/fault-inject.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,
};

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

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

	if (gfpflags & __GFP_NOFAIL)
		return false;

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

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

	/*
	 * 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);
}

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>
4c13dd3b	3	#include <linux/slab.h>
fab9963a JDB	4	#include <linux/mm.h>
fab9963a JDB	5	#include "slab.h"
773ff60e AM	6
	7	static struct {
	8	struct fault_attr attr;
71baba4b	9	bool ignore_gfp_reclaim;
621a5f7a	10	bool cache_filter;
773ff60e AM	11	} failslab = {
773ff60e AM	12	.attr = FAULT_ATTR_INITIALIZER,
71baba4b	13	.ignore_gfp_reclaim = true,
621a5f7a	14	.cache_filter = false,
773ff60e AM	15	};
773ff60e AM	16
4f6923fb	17	bool __should_failslab(struct kmem_cache *s, gfp_t gfpflags)
773ff60e	18	{
ea4452de QZ	19	int flags = 0;
ea4452de QZ	20
fab9963a JDB	21	/* No fault-injection for bootstrap cache */
	22	if (unlikely(s == kmem_cache))
	23	return false;
	24
773ff60e AM	25	if (gfpflags & __GFP_NOFAIL)
	26	return false;
	27
a9659476 NB	28	if (failslab.ignore_gfp_reclaim &&
a9659476 NB	29	(gfpflags & __GFP_DIRECT_RECLAIM))
773ff60e AM	30	return false;
773ff60e AM	31
fab9963a	32	if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB))
4c13dd3b DM	33	return false;
4c13dd3b DM	34
ea4452de QZ	35	/*
	36	* In some cases, it expects to specify __GFP_NOWARN
	37	* to avoid printing any information(not just a warning),
	38	* thus avoiding deadlocks. See commit 6b9dbedbe349 for
	39	* details.
	40	*/
3f913fc5	41	if (gfpflags & __GFP_NOWARN)
ea4452de	42	flags \|= FAULT_NOWARN;
3f913fc5	43
ea4452de	44	return should_fail_ex(&failslab.attr, s->object_size, flags);
773ff60e AM	45	}
	46
	47	static int __init setup_failslab(char *str)
	48	{
	49	return setup_fault_attr(&failslab.attr, str);
	50	}
	51	__setup("failslab=", setup_failslab);
	52
	53	#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
773ff60e AM	54	static int __init failslab_debugfs_init(void)
773ff60e AM	55	{
dd48c085	56	struct dentry *dir;
0825a6f9	57	umode_t mode = S_IFREG \| 0600;
773ff60e	58
dd48c085 AM	59	dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr);
	60	if (IS_ERR(dir))
	61	return PTR_ERR(dir);
773ff60e	62
d9f7979c GKH	63	debugfs_create_bool("ignore-gfp-wait", mode, dir,
	64	&failslab.ignore_gfp_reclaim);
	65	debugfs_create_bool("cache-filter", mode, dir,
	66	&failslab.cache_filter);
4c13dd3b	67
810f09b8	68	return 0;
773ff60e AM	69	}
	70
	71	late_initcall(failslab_debugfs_init);
	72
	73	#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */