Commit 08a45173 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: allow sparse fixed file sets 



This is in preparation for allowing updates to fixed file sets without
requiring a full unregister+register.

Reviewed-by: default avatarJeff Moyer <jmoyer@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ba816ad6

fs/io_uring.c

+34 −15
Original line number Diff line number Diff line
@@ -2379,6 +2379,8 @@ static int io_req_set_file(struct io_ring_ctx *ctx, const struct sqe_submit *s, 
		if (unlikely(!ctx->user_files ||

		    (unsigned) fd >= ctx->nr_user_files))

			return -EBADF;

		if (!ctx->user_files[fd])

			return -EBADF;

		req->file = ctx->user_files[fd];

		req->flags |= REQ_F_FIXED_FILE;

	} else {
@@ -2999,6 +3001,7 @@ static void __io_sqe_files_unregister(struct io_ring_ctx *ctx) 
	int i;



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

		if (ctx->user_files[i])

			fput(ctx->user_files[i]);

#endif

}
@@ -3067,7 +3070,7 @@ static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset) 
	struct sock *sk = ctx->ring_sock->sk;

	struct scm_fp_list *fpl;

	struct sk_buff *skb;

	int i;

	int i, nr_files;



	if (!capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) {

		unsigned long inflight = ctx->user->unix_inflight + nr;
@@ -3087,21 +3090,31 @@ static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset) 
	}



	skb->sk = sk;

	skb->destructor = io_destruct_skb;



	nr_files = 0;

	fpl->user = get_uid(ctx->user);

	for (i = 0; i < nr; i++) {

		fpl->fp[i] = get_file(ctx->user_files[i + offset]);

		unix_inflight(fpl->user, fpl->fp[i]);

		if (!ctx->user_files[i + offset])

			continue;

		fpl->fp[nr_files] = get_file(ctx->user_files[i + offset]);

		unix_inflight(fpl->user, fpl->fp[nr_files]);

		nr_files++;

	}



	fpl->max = fpl->count = nr;

	if (nr_files) {

		fpl->max = SCM_MAX_FD;

		fpl->count = nr_files;

		UNIXCB(skb).fp = fpl;

		skb->destructor = io_destruct_skb;

		refcount_add(skb->truesize, &sk->sk_wmem_alloc);

		skb_queue_head(&sk->sk_receive_queue, skb);



	for (i = 0; i < nr; i++)

		for (i = 0; i < nr_files; i++)

			fput(fpl->fp[i]);

	} else {

		kfree_skb(skb);

		kfree(fpl);

	}



	return 0;

}
@@ -3132,6 +3145,7 @@ static int io_sqe_files_scm(struct io_ring_ctx *ctx) 
		return 0;



	while (total < ctx->nr_user_files) {

		if (ctx->user_files[total])

			fput(ctx->user_files[total]);

		total++;

	}
@@ -3163,10 +3177,15 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, 
	if (!ctx->user_files)

		return -ENOMEM;



	for (i = 0; i < nr_args; i++) {

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

		ret = -EFAULT;

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

			break;

		/* allow sparse sets */

		if (fd == -1) {

			ret = 0;

			continue;

		}



		ctx->user_files[i] = fget(fd);
@@ -3184,12 +3203,12 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, 
			fput(ctx->user_files[i]);

			break;

		}

		ctx->nr_user_files++;

		ret = 0;

	}



	if (ret) {

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

			if (ctx->user_files[i])

				fput(ctx->user_files[i]);



		kfree(ctx->user_files);