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Commit 686d550d authored by Christoph Lameter's avatar Christoph Lameter Committed by Pekka Enberg
Browse files

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: default avatarGlauber Costa <glommer@parallels.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
Signed-off-by: default avatarPekka Enberg <penberg@kernel.org>
parent 208c4358

mm/slab_common.c

+24 −4
Original line number Diff line number Diff line
@@ -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)



	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;

}