1 files changed, 65 insertions, 1 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index dd9b5332b39c..44ff473dab3e 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -148,6 +148,8 @@ struct crypt_config {
 	mempool_t *tag_pool;
 	unsigned tag_pool_max_sectors;
 
+	struct percpu_counter n_allocated_pages;
+
 	struct bio_set *bs;
 	struct mutex bio_alloc_lock;
 
@@ -219,6 +221,12 @@ struct crypt_config {
 #define MAX_TAG_SIZE	480
 #define POOL_ENTRY_SIZE	512
 
+static DEFINE_SPINLOCK(dm_crypt_clients_lock);
+static unsigned dm_crypt_clients_n = 0;
+static volatile unsigned long dm_crypt_pages_per_client;
+#define DM_CRYPT_MEMORY_PERCENT			2
+#define DM_CRYPT_MIN_PAGES_PER_CLIENT		(BIO_MAX_PAGES * 16)
+
 static void clone_init(struct dm_crypt_io *, struct bio *);
 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
@@ -2155,6 +2163,43 @@ static int crypt_wipe_key(struct crypt_config *cc)
 	return r;
 }
 
+static void crypt_calculate_pages_per_client(void)
+{
+	unsigned long pages = (totalram_pages - totalhigh_pages) * DM_CRYPT_MEMORY_PERCENT / 100;
+
+	if (!dm_crypt_clients_n)
+		return;
+
+	pages /= dm_crypt_clients_n;
+	if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT)
+		pages = DM_CRYPT_MIN_PAGES_PER_CLIENT;
+	dm_crypt_pages_per_client = pages;
+}
+
+static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data)
+{
+	struct crypt_config *cc = pool_data;
+	struct page *page;
+
+	if (unlikely(percpu_counter_compare(&cc->n_allocated_pages, dm_crypt_pages_per_client) >= 0) &&
+	    likely(gfp_mask & __GFP_NORETRY))
+		return NULL;
+
+	page = alloc_page(gfp_mask);
+	if (likely(page != NULL))
+		percpu_counter_add(&cc->n_allocated_pages, 1);
+
+	return page;
+}
+
+static void crypt_page_free(void *page, void *pool_data)
+{
+	struct crypt_config *cc = pool_data;
+
+	__free_page(page);
+	percpu_counter_sub(&cc->n_allocated_pages, 1);
+}
+
 static void crypt_dtr(struct dm_target *ti)
 {
 	struct crypt_config *cc = ti->private;
@@ -2181,6 +2226,10 @@ static void crypt_dtr(struct dm_target *ti)
 	mempool_destroy(cc->req_pool);
 	mempool_destroy(cc->tag_pool);
 
+	if (cc->page_pool)
+		WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0);
+	percpu_counter_destroy(&cc->n_allocated_pages);
+
 	if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
 		cc->iv_gen_ops->dtr(cc);
 
@@ -2197,6 +2246,12 @@ static void crypt_dtr(struct dm_target *ti)
 
 	/* Must zero key material before freeing */
 	kzfree(cc);
+
+	spin_lock(&dm_crypt_clients_lock);
+	WARN_ON(!dm_crypt_clients_n);
+	dm_crypt_clients_n--;
+	crypt_calculate_pages_per_client();
+	spin_unlock(&dm_crypt_clients_lock);
 }
 
 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
@@ -2644,6 +2699,15 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
 	ti->private = cc;
 
+	spin_lock(&dm_crypt_clients_lock);
+	dm_crypt_clients_n++;
+	crypt_calculate_pages_per_client();
+	spin_unlock(&dm_crypt_clients_lock);
+
+	ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL);
+	if (ret < 0)
+		goto bad;
+
 	/* Optional parameters need to be read before cipher constructor */
 	if (argc > 5) {
 		ret = crypt_ctr_optional(ti, argc - 5, &argv[5]);
@@ -2698,7 +2762,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size,
 		      ARCH_KMALLOC_MINALIGN);
 
-	cc->page_pool = mempool_create_page_pool(BIO_MAX_PAGES, 0);
+	cc->page_pool = mempool_create(BIO_MAX_PAGES, crypt_page_alloc, crypt_page_free, cc);
 	if (!cc->page_pool) {
 		ti->error = "Cannot allocate page mempool";
 		goto bad;