Commit 9a10867a authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: add task-refs-get helper 



As we have a more complicated task referencing, which apart from normal
task references includes taking tctx->inflight and caching all that, it
would be a good idea to have all that isolated in helpers.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d9114d037f1c195897aa13f38a496078eca2afdb.1630023531.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a8295b98

fs/io_uring.c

+19 −11
Original line number Diff line number Diff line
@@ -1670,6 +1670,24 @@ static inline void io_put_task(struct task_struct *task, int nr) 
	}

}



static void io_task_refs_refill(struct io_uring_task *tctx)

{

	unsigned int refill = -tctx->cached_refs + IO_TCTX_REFS_CACHE_NR;



	percpu_counter_add(&tctx->inflight, refill);

	refcount_add(refill, &current->usage);

	tctx->cached_refs += refill;

}



static inline void io_get_task_refs(int nr)

{

	struct io_uring_task *tctx = current->io_uring;



	tctx->cached_refs -= nr;

	if (unlikely(tctx->cached_refs < 0))

		io_task_refs_refill(tctx);

}



static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data,

				     long res, unsigned int cflags)

{
@@ -6890,25 +6908,15 @@ static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx) 
static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)

	__must_hold(&ctx->uring_lock)

{

	struct io_uring_task *tctx;

	int submitted = 0;



	/* make sure SQ entry isn't read before tail */

	nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx));

	if (!percpu_ref_tryget_many(&ctx->refs, nr))

		return -EAGAIN;

	io_get_task_refs(nr);



	tctx = current->io_uring;

	tctx->cached_refs -= nr;

	if (unlikely(tctx->cached_refs < 0)) {

		unsigned int refill = -tctx->cached_refs + IO_TCTX_REFS_CACHE_NR;



		percpu_counter_add(&tctx->inflight, refill);

		refcount_add(refill, &current->usage);

		tctx->cached_refs += refill;

	}

	io_submit_state_start(&ctx->submit_state, nr);



	while (submitted < nr) {

		const struct io_uring_sqe *sqe;

		struct io_kiocb *req;