Commit bc24d6bd authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: add notification slot registration 



Let the userspace to register and unregister notification slots.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a0aa8161fe3ebb2a4cc6e5dbd0cffb96e6881cf5.1657643355.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 68ef5578

include/uapi/linux/io_uring.h

+17 −0
Original line number Original line Diff line number Diff line
@@ -457,6 +457,10 @@ enum { 
	/* register a range of fixed file slots for automatic slot allocation */

	/* register a range of fixed file slots for automatic slot allocation */

	IORING_REGISTER_FILE_ALLOC_RANGE	= 25,

	IORING_REGISTER_FILE_ALLOC_RANGE	= 25,





	/* zerocopy notification API */

	IORING_REGISTER_NOTIFIERS		= 26,

	IORING_UNREGISTER_NOTIFIERS		= 27,



	/* this goes last */

	/* this goes last */

	IORING_REGISTER_LAST

	IORING_REGISTER_LAST

};

};
@@ -503,6 +507,19 @@ struct io_uring_rsrc_update2 { 
	__u32 resv2;

	__u32 resv2;

};

};





struct io_uring_notification_slot {

	__u64 tag;

	__u64 resv[3];

};



struct io_uring_notification_register {

	__u32 nr_slots;

	__u32 resv;

	__u64 resv2;

	__u64 data;

	__u64 resv3;

};



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

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

#define IORING_REGISTER_FILES_SKIP	(-2)

#define IORING_REGISTER_FILES_SKIP	(-2)

io_uring/io_uring.c

+9 −0
Original line number Original line Diff line number Diff line
@@ -3870,6 +3870,15 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, 
			break;

			break;

		ret = io_register_file_alloc_range(ctx, arg);

		ret = io_register_file_alloc_range(ctx, arg);

		break;

		break;

	case IORING_REGISTER_NOTIFIERS:

		ret = io_notif_register(ctx, arg, nr_args);

		break;

	case IORING_UNREGISTER_NOTIFIERS:

		ret = -EINVAL;

		if (arg || nr_args)

			break;

		ret = io_notif_unregister(ctx);

		break;

	default:

	default:

		ret = -EINVAL;

		ret = -EINVAL;

		break;

		break;

io_uring/notif.c

+43 −0
Original line number Original line Diff line number Diff line
@@ -162,5 +162,48 @@ __cold int io_notif_unregister(struct io_ring_ctx *ctx) 
	kvfree(ctx->notif_slots);

	kvfree(ctx->notif_slots);

	ctx->notif_slots = NULL;

	ctx->notif_slots = NULL;

	ctx->nr_notif_slots = 0;

	ctx->nr_notif_slots = 0;

	io_notif_cache_purge(ctx);

	return 0;

}



__cold int io_notif_register(struct io_ring_ctx *ctx,

			     void __user *arg, unsigned int size)

	__must_hold(&ctx->uring_lock)

{

	struct io_uring_notification_slot __user *slots;

	struct io_uring_notification_slot slot;

	struct io_uring_notification_register reg;

	unsigned i;



	if (ctx->nr_notif_slots)

		return -EBUSY;

	if (size != sizeof(reg))

		return -EINVAL;

	if (copy_from_user(&reg, arg, sizeof(reg)))

		return -EFAULT;

	if (!reg.nr_slots || reg.nr_slots > IORING_MAX_NOTIF_SLOTS)

		return -EINVAL;

	if (reg.resv || reg.resv2 || reg.resv3)

		return -EINVAL;



	slots = u64_to_user_ptr(reg.data);

	ctx->notif_slots = kvcalloc(reg.nr_slots, sizeof(ctx->notif_slots[0]),

				GFP_KERNEL_ACCOUNT);

	if (!ctx->notif_slots)

		return -ENOMEM;



	for (i = 0; i < reg.nr_slots; i++, ctx->nr_notif_slots++) {

		struct io_notif_slot *notif_slot = &ctx->notif_slots[i];



		if (copy_from_user(&slot, &slots[i], sizeof(slot))) {

			io_notif_unregister(ctx);

			return -EFAULT;

		}

		if (slot.resv[0] | slot.resv[1] | slot.resv[2]) {

			io_notif_unregister(ctx);

			return -EINVAL;

		}

		notif_slot->tag = slot.tag;

	}

	return 0;

	return 0;

}
 
}

io_uring/notif.h

+3 −0
Original line number Original line Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include <linux/nospec.h>

#include <linux/nospec.h>





#define IO_NOTIF_SPLICE_BATCH	32

#define IO_NOTIF_SPLICE_BATCH	32

#define IORING_MAX_NOTIF_SLOTS (1U << 10)





struct io_notif {

struct io_notif {

	struct ubuf_info	uarg;

	struct ubuf_info	uarg;
@@ -48,6 +49,8 @@ struct io_notif_slot { 
	u32			seq;

	u32			seq;

};

};





int io_notif_register(struct io_ring_ctx *ctx,

		      void __user *arg, unsigned int size);

int io_notif_unregister(struct io_ring_ctx *ctx);

int io_notif_unregister(struct io_ring_ctx *ctx);

void io_notif_cache_purge(struct io_ring_ctx *ctx);

void io_notif_cache_purge(struct io_ring_ctx *ctx);