Commit f5fa38c5 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
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io_wq: add per-wq work handler instead of per work 



io_uring is the only user of io-wq, and now it uses only io-wq callback
for all its requests, namely io_wq_submit_work(). Instead of storing
work->runner callback in each instance of io_wq_work, keep it in io-wq
itself.

pros:
- reduces io_wq_work size
- more robust -- ->func won't be invalidated with mem{cpy,set}(req)
- helps other work

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent d4c81f38

fs/io-wq.c

+6 −4
Original line number Diff line number Diff line
@@ -112,6 +112,7 @@ struct io_wq { 
	unsigned long state;



	free_work_fn *free_work;

	io_wq_work_fn *do_work;



	struct task_struct *manager;

	struct user_struct *user;
@@ -528,7 +529,7 @@ static void io_worker_handle_work(struct io_worker *worker) 


			hash = io_get_work_hash(work);

			linked = old_work = work;

			linked->func(&linked);

			wq->do_work(&linked);

			linked = (old_work == linked) ? NULL : linked;



			work = next_hashed;
@@ -785,7 +786,7 @@ static void io_run_cancel(struct io_wq_work *work, struct io_wqe *wqe) 
		struct io_wq_work *old_work = work;



		work->flags |= IO_WQ_WORK_CANCEL;

		work->func(&work);

		wq->do_work(&work);

		work = (work == old_work) ? NULL : work;

		wq->free_work(old_work);

	} while (work);
@@ -1023,7 +1024,7 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data) 
	int ret = -ENOMEM, node;

	struct io_wq *wq;



	if (WARN_ON_ONCE(!data->free_work))

	if (WARN_ON_ONCE(!data->free_work || !data->do_work))

		return ERR_PTR(-EINVAL);



	wq = kzalloc(sizeof(*wq), GFP_KERNEL);
@@ -1037,6 +1038,7 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data) 
	}



	wq->free_work = data->free_work;

	wq->do_work = data->do_work;



	/* caller must already hold a reference to this */

	wq->user = data->user;
@@ -1093,7 +1095,7 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data) 


bool io_wq_get(struct io_wq *wq, struct io_wq_data *data)

{

	if (data->free_work != wq->free_work)

	if (data->free_work != wq->free_work || data->do_work != wq->do_work)

		return false;



	return refcount_inc_not_zero(&wq->use_refs);

fs/io-wq.h

+4 −3
Original line number Diff line number Diff line
@@ -85,7 +85,6 @@ static inline void wq_list_del(struct io_wq_work_list *list, 


struct io_wq_work {

	struct io_wq_work_node list;

	void (*func)(struct io_wq_work **);

	struct files_struct *files;

	struct mm_struct *mm;

	const struct cred *creds;
@@ -94,9 +93,9 @@ struct io_wq_work { 
	pid_t task_pid;

};



#define INIT_IO_WORK(work, _func)				\

#define INIT_IO_WORK(work)					\

	do {							\

		*(work) = (struct io_wq_work){ .func = _func };	\

		*(work) = (struct io_wq_work){};		\

	} while (0)						\



static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
@@ -108,10 +107,12 @@ static inline struct io_wq_work *wq_next_work(struct io_wq_work *work) 
}



typedef void (free_work_fn)(struct io_wq_work *);

typedef void (io_wq_work_fn)(struct io_wq_work **);



struct io_wq_data {

	struct user_struct *user;



	io_wq_work_fn *do_work;

	free_work_fn *free_work;

};

fs/io_uring.c

+2 −1
Original line number Diff line number Diff line
@@ -5776,7 +5776,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, 
	refcount_set(&req->refs, 2);

	req->task = NULL;

	req->result = 0;

	INIT_IO_WORK(&req->work, io_wq_submit_work);

	INIT_IO_WORK(&req->work);



	if (unlikely(req->opcode >= IORING_OP_LAST))

		return -EINVAL;
@@ -6796,6 +6796,7 @@ static int io_init_wq_offload(struct io_ring_ctx *ctx, 


	data.user = ctx->user;

	data.free_work = io_free_work;

	data.do_work = io_wq_submit_work;



	if (!(p->flags & IORING_SETUP_ATTACH_WQ)) {

		/* Do QD, or 4 * CPUS, whatever is smallest */