Commit 432c7997 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

aio: separate out ring reservation from req allocation 



This is in preparation for certain types of IO not needing a ring
reserveration.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent bc9bff61

fs/aio.c

+17 −13
Original line number Diff line number Diff line
@@ -902,7 +902,7 @@ static void put_reqs_available(struct kioctx *ctx, unsigned nr) 
	local_irq_restore(flags);

}



static bool get_reqs_available(struct kioctx *ctx)

static bool __get_reqs_available(struct kioctx *ctx)

{

	struct kioctx_cpu *kcpu;

	bool ret = false;
@@ -994,6 +994,14 @@ static void user_refill_reqs_available(struct kioctx *ctx) 
	spin_unlock_irq(&ctx->completion_lock);

}



static bool get_reqs_available(struct kioctx *ctx)

{

	if (__get_reqs_available(ctx))

		return true;

	user_refill_reqs_available(ctx);

	return __get_reqs_available(ctx);

}



/* aio_get_req

 *	Allocate a slot for an aio request.

 * Returns NULL if no requests are free.
@@ -1002,24 +1010,15 @@ static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx) 
{

	struct aio_kiocb *req;



	if (!get_reqs_available(ctx)) {

		user_refill_reqs_available(ctx);

		if (!get_reqs_available(ctx))

			return NULL;

	}



	req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO);

	if (unlikely(!req))

		goto out_put;

		return NULL;



	percpu_ref_get(&ctx->reqs);

	INIT_LIST_HEAD(&req->ki_list);

	refcount_set(&req->ki_refcnt, 0);

	req->ki_ctx = ctx;

	return req;

out_put:

	put_reqs_available(ctx, 1);

	return NULL;

}



static struct kioctx *lookup_ioctx(unsigned long ctx_id)
@@ -1807,9 +1806,13 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, 
		return -EINVAL;

	}



	if (!get_reqs_available(ctx))

		return -EAGAIN;



	ret = -EAGAIN;

	req = aio_get_req(ctx);

	if (unlikely(!req))

		return -EAGAIN;

		goto out_put_reqs_available;



	if (iocb.aio_flags & IOCB_FLAG_RESFD) {

		/*
@@ -1872,11 +1875,12 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, 
		goto out_put_req;

	return 0;

out_put_req:

	put_reqs_available(ctx, 1);

	percpu_ref_put(&ctx->reqs);

	if (req->ki_eventfd)

		eventfd_ctx_put(req->ki_eventfd);

	kmem_cache_free(kiocb_cachep, req);

out_put_reqs_available:

	put_reqs_available(ctx, 1);

	return ret;

}