crypto: change transient busy return code to -ENOSPC

The crypto API was using the -EBUSY return value to indicate
both a hard failure to submit a crypto operation into a
transformation provider when the latter was busy and the backlog
mechanism was not enabled as well as a notification that the
operation was queued into the backlog when the backlog mechanism
was enabled.

Having the same return code indicate two very different conditions
depending on a flag is both error prone and requires extra runtime
check like the following to discern between the cases:

	if (err == -EINPROGRESS ||
	    (err == -EBUSY && (ahash_request_flags(req) &
			       CRYPTO_TFM_REQ_MAY_BACKLOG)))

This patch changes the return code used to indicate a crypto op
failed due to the transformation provider being transiently busy
to -ENOSPC.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/algapi.c b/crypto/algapi.c
index aa699ff..60d7366 100644 (file)
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -897,9 +897,11 @@ int crypto_enqueue_request(struct crypto_queue *queue,
        int err = -EINPROGRESS;
 
        if (unlikely(queue->qlen >= queue->max_qlen)) {
-               err = -EBUSY;
-               if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
+               if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) {
+                       err = -ENOSPC;
                        goto out;
+               }
+               err = -EBUSY;
                if (queue->backlog == &queue->list)
                        queue->backlog = &request->list;
        }

diff --git a/crypto/cryptd.c b/crypto/cryptd.c
index 0508c48..bd43cf5 100644 (file)
--- a/crypto/cryptd.c
+++ b/crypto/cryptd.c
@@ -137,16 +137,14 @@ static int cryptd_enqueue_request(struct cryptd_queue *queue,
        int cpu, err;
        struct cryptd_cpu_queue *cpu_queue;
        atomic_t *refcnt;
-       bool may_backlog;
 
        cpu = get_cpu();
        cpu_queue = this_cpu_ptr(queue->cpu_queue);
        err = crypto_enqueue_request(&cpu_queue->queue, request);
 
        refcnt = crypto_tfm_ctx(request->tfm);
-       may_backlog = request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG;
 
-       if (err == -EBUSY && !may_backlog)
+       if (err == -ENOSPC)
                goto out_put_cpu;
 
        queue_work_on(cpu, kcrypto_wq, &cpu_queue->work);