Commit 6b80ea38 authored Oct 18, 2017 by Gilad Ben-Yossef Committed by Herbert Xu Nov 03, 2017

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>

parent c8dd5e45

crypto/algapi.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -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;
		}

crypto/cryptd.c

+1 −3

Original line number	Diff line number	Diff line
		@@ -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);

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