Commit 792e3582 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: add IORING_REGISTER_RSRC 



Add a new io_uring_register() opcode for rsrc registeration. Instead of
accepting a pointer to resources, fds or iovecs, it @arg is now pointing
to a struct io_uring_rsrc_register, and the second argument tells how
large that struct is to make it easily extendible by adding new fields.

All that is done mainly to be able to pass in a pointer with tags. Pass
it in and enable CQE posting for file resources. Doesn't support setting
tags on update yet.

A design choice made here is to not post CQEs on rsrc de-registration,
but only when we updated-removed it by rsrc dynamic update.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c498aaec32a4bb277b2406b9069662c02cdda98c.1619356238.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent fdecb662

fs/io_uring.c

+40 −5
Original line number Diff line number Diff line
@@ -7589,7 +7589,7 @@ static struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx) 
}



static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,

				 unsigned nr_args)

				 unsigned nr_args, u64 __user *tags)

{

	__s32 __user *fds = (__s32 __user *) arg;

	struct file *file;
@@ -7616,17 +7616,24 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, 
		goto out_free;



	for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {

		if (copy_from_user(&fd, &fds[i], sizeof(fd))) {

		u64 tag = 0;



		if ((tags && copy_from_user(&tag, &tags[i], sizeof(tag))) ||

		    copy_from_user(&fd, &fds[i], sizeof(fd))) {

			ret = -EFAULT;

			goto out_fput;

		}

		/* allow sparse sets */

		if (fd == -1)

		if (fd == -1) {

			ret = -EINVAL;

			if (unlikely(tag))

				goto out_fput;

			continue;

		}



		file = fget(fd);

		ret = -EBADF;

		if (!file)

		if (unlikely(!file))

			goto out_fput;



		/*
@@ -7640,6 +7647,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, 
			fput(file);

			goto out_fput;

		}

		ctx->file_data->tags[i] = tag;

		io_fixed_file_set(io_fixed_file_slot(&ctx->file_table, i), file);

	}
@@ -9743,6 +9751,29 @@ static int io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type, 
	return __io_register_rsrc_update(ctx, type, &up, nr_args);

}



static int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg,

			    unsigned int size)

{

	struct io_uring_rsrc_register rr;



	/* keep it extendible */

	if (size != sizeof(rr))

		return -EINVAL;



	memset(&rr, 0, sizeof(rr));

	if (copy_from_user(&rr, arg, size))

		return -EFAULT;

	if (!rr.nr)

		return -EINVAL;



	switch (rr.type) {

	case IORING_RSRC_FILE:

		return io_sqe_files_register(ctx, u64_to_user_ptr(rr.data),

					     rr.nr, u64_to_user_ptr(rr.tags));

	}

	return -EINVAL;

}



static bool io_register_op_must_quiesce(int op)

{

	switch (op) {
@@ -9752,6 +9783,7 @@ static bool io_register_op_must_quiesce(int op) 
	case IORING_REGISTER_PROBE:

	case IORING_REGISTER_PERSONALITY:

	case IORING_UNREGISTER_PERSONALITY:

	case IORING_REGISTER_RSRC:

		return false;

	default:

		return true;
@@ -9820,7 +9852,7 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, 
		ret = io_sqe_buffers_unregister(ctx);

		break;

	case IORING_REGISTER_FILES:

		ret = io_sqe_files_register(ctx, arg, nr_args);

		ret = io_sqe_files_register(ctx, arg, nr_args, NULL);

		break;

	case IORING_UNREGISTER_FILES:

		ret = -EINVAL;
@@ -9877,6 +9909,9 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, 
	case IORING_REGISTER_RESTRICTIONS:

		ret = io_register_restrictions(ctx, arg, nr_args);

		break;

	case IORING_REGISTER_RSRC:

		ret = io_register_rsrc(ctx, arg, nr_args);

		break;

	default:

		ret = -EINVAL;

		break;

include/uapi/linux/io_uring.h

+8 −0
Original line number Diff line number Diff line
@@ -298,6 +298,7 @@ enum { 
	IORING_UNREGISTER_PERSONALITY		= 10,

	IORING_REGISTER_RESTRICTIONS		= 11,

	IORING_REGISTER_ENABLE_RINGS		= 12,

	IORING_REGISTER_RSRC			= 13,



	/* this goes last */

	IORING_REGISTER_LAST
@@ -320,6 +321,13 @@ enum { 
	IORING_RSRC_FILE		= 0,

};



struct io_uring_rsrc_register {

	__u32 type;

	__u32 nr;

	__aligned_u64 data;

	__aligned_u64 tags;

};



/* Skip updating fd indexes set to this value in the fd table */

#define IORING_REGISTER_FILES_SKIP	(-2)