linux/mm/failslab.c
Qi Zheng 3f913fc5f9 mm: fix missing handler for __GFP_NOWARN
We expect no warnings to be issued when we specify __GFP_NOWARN, but
currently in paths like alloc_pages() and kmalloc(), there are still some
warnings printed, fix it.

But for some warnings that report usage problems, we don't deal with them.
If such warnings are printed, then we should fix the usage problems. 
Such as the following case:

	WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));

[zhengqi.arch@bytedance.com: v2]
 Link: https://lkml.kernel.org/r/20220511061951.1114-1-zhengqi.arch@bytedance.com
Link: https://lkml.kernel.org/r/20220510113809.80626-1-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-19 14:08:55 -07:00

66 lines
1.4 KiB
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)
{
/* 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;
if (gfpflags & __GFP_NOWARN)
failslab.attr.no_warn = true;
return should_fail(&failslab.attr, s->object_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)
{
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 */