mm, mempool: do not allow atomic resizing
Allocating a large number of elements in atomic context could quickly
deplete memory reserves, so just disallow atomic resizing entirely.
Nothing currently uses mempool_resize() with anything other than
GFP_KERNEL, so convert existing callers to drop the gfp_mask.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Steffen Maier <maier@linux.vnet.ibm.com> [zfcp]
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Steve French <sfrench@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/mempool.c b/mm/mempool.c
index e209c98..949970d 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -113,23 +113,24 @@
* mempool_create().
* @new_min_nr: the new minimum number of elements guaranteed to be
* allocated for this pool.
- * @gfp_mask: the usual allocation bitmask.
*
* This function shrinks/grows the pool. In the case of growing,
* it cannot be guaranteed that the pool will be grown to the new
* size immediately, but new mempool_free() calls will refill it.
+ * This function may sleep.
*
* Note, the caller must guarantee that no mempool_destroy is called
* while this function is running. mempool_alloc() & mempool_free()
* might be called (eg. from IRQ contexts) while this function executes.
*/
-int mempool_resize(mempool_t *pool, int new_min_nr, gfp_t gfp_mask)
+int mempool_resize(mempool_t *pool, int new_min_nr)
{
void *element;
void **new_elements;
unsigned long flags;
BUG_ON(new_min_nr <= 0);
+ might_sleep();
spin_lock_irqsave(&pool->lock, flags);
if (new_min_nr <= pool->min_nr) {
@@ -145,7 +146,8 @@
spin_unlock_irqrestore(&pool->lock, flags);
/* Grow the pool */
- new_elements = kmalloc(new_min_nr * sizeof(*new_elements), gfp_mask);
+ new_elements = kmalloc_array(new_min_nr, sizeof(*new_elements),
+ GFP_KERNEL);
if (!new_elements)
return -ENOMEM;
@@ -164,7 +166,7 @@
while (pool->curr_nr < pool->min_nr) {
spin_unlock_irqrestore(&pool->lock, flags);
- element = pool->alloc(gfp_mask, pool->pool_data);
+ element = pool->alloc(GFP_KERNEL, pool->pool_data);
if (!element)
goto out;
spin_lock_irqsave(&pool->lock, flags);