mm/slab_common: Improve error handling in kmem_cache_create

Instead of using s == NULL use an errorcode. This allows much more
detailed diagnostics as to what went wrong. As we add more functionality
from the slab allocators to the common kmem_cache_create() function we will
also add more error conditions.

Print the error code during the panic as well as in a warning if the module
can handle failure. The API for kmem_cache_create() currently does not allow
the returning of an error code. Return NULL but log the cause of the problem
in the syslog.

Reviewed-by: Glauber Costa <glommer@parallels.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
This commit is contained in:
Christoph Lameter 2012-09-05 00:20:33 +00:00 committed by Pekka Enberg
parent 208c4358dc
commit 686d550d22

View File

@ -98,16 +98,36 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size, size_t align
unsigned long flags, void (*ctor)(void *))
{
struct kmem_cache *s = NULL;
int err = 0;
get_online_cpus();
mutex_lock(&slab_mutex);
if (kmem_cache_sanity_check(name, size) == 0)
s = __kmem_cache_create(name, size, align, flags, ctor);
if (!kmem_cache_sanity_check(name, size) == 0)
goto out_locked;
s = __kmem_cache_create(name, size, align, flags, ctor);
if (!s)
err = -ENOSYS; /* Until __kmem_cache_create returns code */
out_locked:
mutex_unlock(&slab_mutex);
put_online_cpus();
if (!s && (flags & SLAB_PANIC))
panic("kmem_cache_create: Failed to create slab '%s'\n", name);
if (err) {
if (flags & SLAB_PANIC)
panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
name, err);
else {
printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d",
name, err);
dump_stack();
}
return NULL;
}
return s;
}