diff --git a/Documentation/vm/slub.txt b/Documentation/vm/slub.txt
index b37300edf27c8bc528700f00b9045bd3f6a20b2d..07375e73981a8747f1432213691a4187ccf6544a 100644
--- a/Documentation/vm/slub.txt
+++ b/Documentation/vm/slub.txt
@@ -41,6 +41,7 @@ Possible debug options are
P Poisoning (object and padding)
U User tracking (free and alloc)
T Trace (please only use on single slabs)
+ A Toggle failslab filter mark for the cache
O Switch debugging off for caches that would have
caused higher minimum slab orders
- Switch all debugging off (useful if the kernel is
diff --git a/include/linux/fault-inject.h b/include/linux/fault-inject.h
index 06ca9b21dad23b0d6753d0a92d6cbc2acba81f40..7b64ad40e4ceb8683a34ac0cdf76cdb9d4d1220f 100644
--- a/include/linux/fault-inject.h
+++ b/include/linux/fault-inject.h
@@ -82,9 +82,10 @@ static inline void cleanup_fault_attr_dentries(struct fault_attr *attr)
#endif /* CONFIG_FAULT_INJECTION */
#ifdef CONFIG_FAILSLAB
-extern bool should_failslab(size_t size, gfp_t gfpflags);
+extern bool should_failslab(size_t size, gfp_t gfpflags, unsigned long flags);
#else
-static inline bool should_failslab(size_t size, gfp_t gfpflags)
+static inline bool should_failslab(size_t size, gfp_t gfpflags,
+ unsigned long flags)
{
return false;
}
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 2da8372519f5e96a32027a9be8b0efc66f35b907..488446289cab4839670d8ff507d1cfb508d2fc98 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -70,6 +70,11 @@
#else
# define SLAB_NOTRACK 0x00000000UL
#endif
+#ifdef CONFIG_FAILSLAB
+# define SLAB_FAILSLAB 0x02000000UL /* Fault injection mark */
+#else
+# define SLAB_FAILSLAB 0x00000000UL
+#endif
/* The following flags affect the page allocator grouping pages by mobility */
#define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */
diff --git a/mm/failslab.c b/mm/failslab.c
index 9339de5f0a915dc0526e276eddbcc5fb918fb13d..bb41f98dd8b700d7ecf1765aa7e76e6cbd6ad97a 100644
--- a/mm/failslab.c
+++ b/mm/failslab.c
@@ -1,18 +1,22 @@
#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)
+bool should_failslab(size_t size, gfp_t gfpflags, unsigned long cache_flags)
{
if (gfpflags & __GFP_NOFAIL)
return false;
@@ -20,6 +24,9 @@ bool should_failslab(size_t size, gfp_t gfpflags)
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);
}
@@ -30,7 +37,6 @@ static int __init setup_failslab(char *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;
@@ -46,8 +52,14 @@ static int __init failslab_debugfs_init(void)
debugfs_create_bool("ignore-gfp-wait", mode, dir,
&failslab.ignore_gfp_wait);
- if (!failslab.ignore_gfp_wait_file) {
+ 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);
}
diff --git a/mm/slab.c b/mm/slab.c
index 7451bdacaf18875044ea97ed3d49da8c401d8249..33496b7048597fb18850ea4a692e473b65e807ee 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3101,7 +3101,7 @@ static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags)
if (cachep == &cache_cache)
return false;
- return should_failslab(obj_size(cachep), flags);
+ return should_failslab(obj_size(cachep), flags, cachep->flags);
}
static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
diff --git a/mm/slub.c b/mm/slub.c
index 8d71aaf888d770b27ba26df5d4d9592832a87b2d..cab5288736c81e4be98cafaa39e99bec2e2207fd 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -151,7 +151,8 @@
* Set of flags that will prevent slab merging
*/
#define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
- SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE)
+ SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
+ SLAB_FAILSLAB)
#define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
SLAB_CACHE_DMA | SLAB_NOTRACK)
@@ -1020,6 +1021,9 @@ static int __init setup_slub_debug(char *str)
case 't':
slub_debug |= SLAB_TRACE;
break;
+ case 'a':
+ slub_debug |= SLAB_FAILSLAB;
+ break;
default:
printk(KERN_ERR "slub_debug option '%c' "
"unknown. skipped\n", *str);
@@ -1718,7 +1722,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
lockdep_trace_alloc(gfpflags);
might_sleep_if(gfpflags & __GFP_WAIT);
- if (should_failslab(s->objsize, gfpflags))
+ if (should_failslab(s->objsize, gfpflags, s->flags))
return NULL;
local_irq_save(flags);
@@ -4171,6 +4175,23 @@ static ssize_t trace_store(struct kmem_cache *s, const char *buf,
}
SLAB_ATTR(trace);
+#ifdef CONFIG_FAILSLAB
+static ssize_t failslab_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB));
+}
+
+static ssize_t failslab_store(struct kmem_cache *s, const char *buf,
+ size_t length)
+{
+ s->flags &= ~SLAB_FAILSLAB;
+ if (buf[0] == '1')
+ s->flags |= SLAB_FAILSLAB;
+ return length;
+}
+SLAB_ATTR(failslab);
+#endif
+
static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
{
return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
@@ -4467,6 +4488,10 @@ static struct attribute *slab_attrs[] = {
&deactivate_remote_frees_attr.attr,
&order_fallback_attr.attr,
#endif
+#ifdef CONFIG_FAILSLAB
+ &failslab_attr.attr,
+#endif
+
NULL
};