Commit d50f94d7 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring/rsrc: get rid of the empty node and dummy_ubuf 



The empty node was used as a placeholder for a sparse entry, but it
didn't really solve any issues. The caller still has to check for
whether it's the empty node or not, it may as well just check for a NULL
return instead.

The dummy_ubuf was used for a sparse buffer entry, but NULL will serve
the same purpose there of ensuring an -EFAULT on attempted import.

Just use NULL for a sparse node, regardless of whether or not it's a
file or buffer resource.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 4007c3d8

io_uring/fdinfo.c

+7 −2
Original line number Diff line number Diff line
@@ -178,9 +178,14 @@ __cold void io_uring_show_fdinfo(struct seq_file *m, struct file *file) 
	}

	seq_printf(m, "UserBufs:\t%u\n", ctx->buf_table.nr);

	for (i = 0; has_lock && i < ctx->buf_table.nr; i++) {

		struct io_mapped_ubuf *buf = ctx->buf_table.nodes[i]->buf;

		struct io_mapped_ubuf *buf = NULL;



		if (ctx->buf_table.nodes[i])

			buf = ctx->buf_table.nodes[i]->buf;

		if (buf)

			seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, buf->len);

		else

			seq_printf(m, "%5u: <none>\n", i);

	}

	if (has_lock && !xa_empty(&ctx->personalities)) {

		unsigned long index;

io_uring/io_uring.c

+2 −2
Original line number Diff line number Diff line
@@ -947,8 +947,8 @@ void io_req_defer_failed(struct io_kiocb *req, s32 res) 
static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx)

{

	req->ctx = ctx;

	req->rsrc_nodes[IORING_RSRC_FILE] = rsrc_empty_node;

	req->rsrc_nodes[IORING_RSRC_BUFFER] = rsrc_empty_node;

	req->rsrc_nodes[IORING_RSRC_FILE] = NULL;

	req->rsrc_nodes[IORING_RSRC_BUFFER] = NULL;

	req->link = NULL;

	req->async_data = NULL;

	/* not necessary, but safer to zero */

io_uring/notif.c

+2 −2
Original line number Diff line number Diff line
@@ -117,8 +117,8 @@ struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx) 
	notif->file = NULL;

	notif->task = current;

	io_get_task_refs(1);

	notif->rsrc_nodes[IORING_RSRC_FILE] = rsrc_empty_node;

	notif->rsrc_nodes[IORING_RSRC_BUFFER] = rsrc_empty_node;

	notif->rsrc_nodes[IORING_RSRC_FILE] = NULL;

	notif->rsrc_nodes[IORING_RSRC_BUFFER] = NULL;



	nd = io_notif_to_data(notif);

	nd->zc_report = false;

io_uring/rsrc.c

+21 −27
Original line number Diff line number Diff line
@@ -32,17 +32,6 @@ static struct io_rsrc_node *io_sqe_buffer_register(struct io_ring_ctx *ctx, 
#define IORING_MAX_FIXED_FILES	(1U << 20)

#define IORING_MAX_REG_BUFFERS	(1U << 14)



static const struct io_mapped_ubuf dummy_ubuf = {

	/* set invalid range, so io_import_fixed() fails meeting it */

	.ubuf = -1UL,

	.len = UINT_MAX,

};



const struct io_rsrc_node empty_node = {

	.type = IORING_RSRC_BUFFER,

	.buf = (struct io_mapped_ubuf *) &dummy_ubuf,

};



int __io_account_mem(struct user_struct *user, unsigned long nr_pages)

{

	unsigned long page_limit, cur_pages, new_pages;
@@ -116,7 +105,7 @@ static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_rsrc_node *node) 
{

	unsigned int i;



	if (node->buf != &dummy_ubuf) {

	if (node->buf) {

		struct io_mapped_ubuf *imu = node->buf;



		if (!refcount_dec_and_test(&imu->refs))
@@ -265,20 +254,21 @@ static int __io_sqe_buffers_update(struct io_ring_ctx *ctx, 
		err = io_buffer_validate(iov);

		if (err)

			break;

		if (!iov->iov_base && tag) {

			err = -EINVAL;

			break;

		}

		node = io_sqe_buffer_register(ctx, iov, &last_hpage);

		if (IS_ERR(node)) {

			err = PTR_ERR(node);

			break;

		}

		if (tag) {

			if (!node) {

				err = -EINVAL;

				break;

			}

			node->tag = tag;

		}

		i = array_index_nospec(up->offset + done, ctx->buf_table.nr);

		io_reset_rsrc_node(&ctx->buf_table, i);

		ctx->buf_table.nodes[i] = node;

		if (tag)

			node->tag = tag;

		if (ctx->compat)

			user_data += sizeof(struct compat_iovec);

		else
@@ -591,8 +581,11 @@ static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages, 
	/* check previously registered pages */

	for (i = 0; i < ctx->buf_table.nr; i++) {

		struct io_rsrc_node *node = ctx->buf_table.nodes[i];

		struct io_mapped_ubuf *imu = node->buf;

		struct io_mapped_ubuf *imu;



		if (!node)

			continue;

		imu = node->buf;

		for (j = 0; j < imu->nr_bvecs; j++) {

			if (!PageCompound(imu->bvec[j].bv_page))

				continue;
@@ -742,7 +735,7 @@ static struct io_rsrc_node *io_sqe_buffer_register(struct io_ring_ctx *ctx, 
	bool coalesced;



	if (!iov->iov_base)

		return rsrc_empty_node;

		return NULL;



	node = io_rsrc_node_alloc(ctx, IORING_RSRC_BUFFER);

	if (!node)
@@ -850,10 +843,6 @@ int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, 
				ret = -EFAULT;

				break;

			}

			if (tag && !iov->iov_base) {

				ret = -EINVAL;

				break;

			}

		}



		node = io_sqe_buffer_register(ctx, iov, &last_hpage);
@@ -861,8 +850,13 @@ int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, 
			ret = PTR_ERR(node);

			break;

		}

		if (tag)

		if (tag) {

			if (!node) {

				ret = -EINVAL;

				break;

			}

			node->tag = tag;

		}

		data.nodes[i] = node;

	}
@@ -957,8 +951,8 @@ static int io_clone_buffers(struct io_ring_ctx *ctx, struct io_ring_ctx *src_ctx 
		struct io_rsrc_node *dst_node, *src_node;



		src_node = io_rsrc_node_lookup(&src_ctx->buf_table, i);

		if (src_node == rsrc_empty_node) {

			dst_node = rsrc_empty_node;

		if (!src_node) {

			dst_node = NULL;

		} else {

			dst_node = io_rsrc_node_alloc(ctx, IORING_RSRC_BUFFER);

			if (!dst_node) {

io_uring/rsrc.h

+7 −16
Original line number Diff line number Diff line
@@ -67,9 +67,6 @@ int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg, 
int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg,

			unsigned int size, unsigned int type);



extern const struct io_rsrc_node empty_node;

#define rsrc_empty_node	(struct io_rsrc_node *) &empty_node



static inline struct io_rsrc_node *io_rsrc_node_lookup(struct io_rsrc_data *data,

						       int index)

{
@@ -80,7 +77,7 @@ static inline struct io_rsrc_node *io_rsrc_node_lookup(struct io_rsrc_data *data 


static inline void io_put_rsrc_node(struct io_rsrc_node *node)

{

	if (node != rsrc_empty_node && !--node->refs)

	if (node && !--node->refs)

		io_free_rsrc_node(node);

}
@@ -97,24 +94,18 @@ static inline bool io_reset_rsrc_node(struct io_rsrc_data *data, int index) 


static inline void io_req_put_rsrc_nodes(struct io_kiocb *req)

{

	if (req->rsrc_nodes[IORING_RSRC_FILE] != rsrc_empty_node) {

	io_put_rsrc_node(req->rsrc_nodes[IORING_RSRC_FILE]);

		req->rsrc_nodes[IORING_RSRC_FILE] = rsrc_empty_node;

	}

	if (req->rsrc_nodes[IORING_RSRC_BUFFER] != rsrc_empty_node) {

	io_put_rsrc_node(req->rsrc_nodes[IORING_RSRC_BUFFER]);

		req->rsrc_nodes[IORING_RSRC_BUFFER] = rsrc_empty_node;

	}

	req->rsrc_nodes[IORING_RSRC_FILE] = NULL;

	req->rsrc_nodes[IORING_RSRC_BUFFER] = NULL;

}



static inline void io_req_assign_rsrc_node(struct io_kiocb *req,

					   struct io_rsrc_node *node)

{

	if (node != rsrc_empty_node) {

	node->refs++;

	req->rsrc_nodes[node->type] = node;

}

}



int io_files_update(struct io_kiocb *req, unsigned int issue_flags);

int io_files_update_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);