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Diffstat (limited to 'mm/zswap.c')
-rw-r--r--mm/zswap.c34
1 files changed, 24 insertions, 10 deletions
diff --git a/mm/zswap.c b/mm/zswap.c
index 6e0c0fca5830..c7ff9e94520a 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -43,7 +43,7 @@
* statistics
**********************************/
/* The number of compressed pages currently stored in zswap */
-atomic_long_t zswap_stored_pages = ATOMIC_INIT(0);
+atomic_long_t zswap_stored_pages = ATOMIC_LONG_INIT(0);
/*
* The statistics below are not protected from concurrent access for
@@ -881,18 +881,32 @@ static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node)
{
struct zswap_pool *pool = hlist_entry(node, struct zswap_pool, node);
struct crypto_acomp_ctx *acomp_ctx = per_cpu_ptr(pool->acomp_ctx, cpu);
+ struct acomp_req *req;
+ struct crypto_acomp *acomp;
+ u8 *buffer;
+
+ if (IS_ERR_OR_NULL(acomp_ctx))
+ return 0;
mutex_lock(&acomp_ctx->mutex);
- if (!IS_ERR_OR_NULL(acomp_ctx)) {
- if (!IS_ERR_OR_NULL(acomp_ctx->req))
- acomp_request_free(acomp_ctx->req);
- acomp_ctx->req = NULL;
- if (!IS_ERR_OR_NULL(acomp_ctx->acomp))
- crypto_free_acomp(acomp_ctx->acomp);
- kfree(acomp_ctx->buffer);
- }
+ req = acomp_ctx->req;
+ acomp = acomp_ctx->acomp;
+ buffer = acomp_ctx->buffer;
+ acomp_ctx->req = NULL;
+ acomp_ctx->acomp = NULL;
+ acomp_ctx->buffer = NULL;
mutex_unlock(&acomp_ctx->mutex);
+ /*
+ * Do the actual freeing after releasing the mutex to avoid subtle
+ * locking dependencies causing deadlocks.
+ */
+ if (!IS_ERR_OR_NULL(req))
+ acomp_request_free(req);
+ if (!IS_ERR_OR_NULL(acomp))
+ crypto_free_acomp(acomp);
+ kfree(buffer);
+
return 0;
}
@@ -1192,7 +1206,7 @@ static enum lru_status shrink_memcg_cb(struct list_head *item, struct list_lru_o
/*
* It's safe to drop the lock here because we return either
- * LRU_REMOVED_RETRY or LRU_RETRY.
+ * LRU_REMOVED_RETRY, LRU_RETRY or LRU_STOP.
*/
spin_unlock(&l->lock);