Commit b54a1404 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring/rsrc: add io_rsrc_node_lookup() helper 



There are lots of spots open-coding this functionality, add a generic
helper that does the node lookup in a speculation safe way.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 3597f278

io_uring/cancel.c

+5 −3
Original line number Diff line number Diff line
@@ -240,10 +240,12 @@ static int __io_sync_cancel(struct io_uring_task *tctx, 
	/* fixed must be grabbed every time since we drop the uring_lock */

	if ((cd->flags & IORING_ASYNC_CANCEL_FD) &&

	    (cd->flags & IORING_ASYNC_CANCEL_FD_FIXED)) {

		if (unlikely(fd >= ctx->file_table.data.nr))

		struct io_rsrc_node *node;



		node = io_rsrc_node_lookup(&ctx->file_table.data, fd);

		if (unlikely(!node))

			return -EBADF;

		fd = array_index_nospec(fd, ctx->file_table.data.nr);

		cd->file = io_file_from_index(&ctx->file_table, fd);

		cd->file = io_slot_file(node);

		if (!cd->file)

			return -EBADF;

	}

io_uring/filetable.c

+9 −7
Original line number Diff line number Diff line
@@ -58,7 +58,7 @@ static int io_install_fixed_file(struct io_ring_ctx *ctx, struct file *file, 
				 u32 slot_index)

	__must_hold(&req->ctx->uring_lock)

{

	struct io_rsrc_node *node;

	struct io_rsrc_node *node, *old_node;



	if (io_is_uring_fops(file))

		return -EBADF;
@@ -71,9 +71,9 @@ static int io_install_fixed_file(struct io_ring_ctx *ctx, struct file *file, 
	if (!node)

		return -ENOMEM;



	slot_index = array_index_nospec(slot_index, ctx->file_table.data.nr);

	if (ctx->file_table.data.nodes[slot_index])

		io_put_rsrc_node(ctx->file_table.data.nodes[slot_index]);

	old_node = io_rsrc_node_lookup(&ctx->file_table.data, slot_index);

	if (old_node)

		io_put_rsrc_node(old_node);

	else

		io_file_bitmap_set(&ctx->file_table, slot_index);
@@ -123,15 +123,17 @@ int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags, 


int io_fixed_fd_remove(struct io_ring_ctx *ctx, unsigned int offset)

{

	struct io_rsrc_node *node;



	if (unlikely(!ctx->file_table.data.nr))

		return -ENXIO;

	if (offset >= ctx->file_table.data.nr)

		return -EINVAL;



	offset = array_index_nospec(offset, ctx->file_table.data.nr);

	if (!ctx->file_table.data.nodes[offset])

	node = io_rsrc_node_lookup(&ctx->file_table.data, offset);

	if (!node)

		return -EBADF;

	io_put_rsrc_node(ctx->file_table.data.nodes[offset]);

	io_put_rsrc_node(node);

	ctx->file_table.data.nodes[offset] = NULL;

	io_file_bitmap_clear(&ctx->file_table, offset);

	return 0;

io_uring/filetable.h

+1 −1
Original line number Diff line number Diff line
@@ -52,7 +52,7 @@ static inline struct file *io_slot_file(struct io_rsrc_node *node) 
static inline struct file *io_file_from_index(struct io_file_table *table,

					      int index)

{

	struct io_rsrc_node *node = table->data.nodes[index];

	struct io_rsrc_node *node = io_rsrc_node_lookup(&table->data, index);



	if (node)

		return io_slot_file(node);

io_uring/io_uring.c

+1 −5
Original line number Diff line number Diff line
@@ -1879,16 +1879,12 @@ inline struct file *io_file_get_fixed(struct io_kiocb *req, int fd, 
	struct file *file = NULL;



	io_ring_submit_lock(ctx, issue_flags);

	if (unlikely((unsigned int)fd >= ctx->file_table.data.nr))

		goto out;

	fd = array_index_nospec(fd, ctx->file_table.data.nr);

	node = ctx->file_table.data.nodes[fd];

	node = io_rsrc_node_lookup(&ctx->file_table.data, fd);

	if (node) {

		io_req_assign_rsrc_node(req, node);

		req->flags |= io_slot_flags(node);

		file = io_slot_file(node);

	}

out:

	io_ring_submit_unlock(ctx, issue_flags);

	return file;

}

io_uring/msg_ring.c

+15 −16
Original line number Diff line number Diff line
@@ -172,22 +172,24 @@ static int io_msg_ring_data(struct io_kiocb *req, unsigned int issue_flags) 
	return __io_msg_ring_data(target_ctx, msg, issue_flags);

}



static struct file *io_msg_grab_file(struct io_kiocb *req, unsigned int issue_flags)

static int io_msg_grab_file(struct io_kiocb *req, unsigned int issue_flags)

{

	struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg);

	struct io_ring_ctx *ctx = req->ctx;

	struct file *file = NULL;

	int idx = msg->src_fd;

	struct io_rsrc_node *node;

	int ret = -EBADF;



	io_ring_submit_lock(ctx, issue_flags);

	if (likely(idx < ctx->file_table.data.nr)) {

		idx = array_index_nospec(idx, ctx->file_table.data.nr);

		file = io_file_from_index(&ctx->file_table, idx);

		if (file)

			get_file(file);

	node = io_rsrc_node_lookup(&ctx->file_table.data, msg->src_fd);

	if (node) {

		msg->src_file = io_slot_file(node);

		if (msg->src_file)

			get_file(msg->src_file);

		req->flags |= REQ_F_NEED_CLEANUP;

		ret = 0;

	}

	io_ring_submit_unlock(ctx, issue_flags);

	return file;

	return ret;

}



static int io_msg_install_complete(struct io_kiocb *req, unsigned int issue_flags)
@@ -256,7 +258,6 @@ static int io_msg_send_fd(struct io_kiocb *req, unsigned int issue_flags) 
	struct io_ring_ctx *target_ctx = req->file->private_data;

	struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg);

	struct io_ring_ctx *ctx = req->ctx;

	struct file *src_file = msg->src_file;



	if (msg->len)

		return -EINVAL;
@@ -264,12 +265,10 @@ static int io_msg_send_fd(struct io_kiocb *req, unsigned int issue_flags) 
		return -EINVAL;

	if (target_ctx->flags & IORING_SETUP_R_DISABLED)

		return -EBADFD;

	if (!src_file) {

		src_file = io_msg_grab_file(req, issue_flags);

		if (!src_file)

			return -EBADF;

		msg->src_file = src_file;

		req->flags |= REQ_F_NEED_CLEANUP;

	if (!msg->src_file) {

		int ret = io_msg_grab_file(req, issue_flags);

		if (unlikely(ret))

			return ret;

	}



	if (io_msg_need_remote(target_ctx))