io_uring: split out fixed file installation and removal

Put it with the filetable code, which is where it belongs. While doing
so, have the helpers take a ctx rather than an io_kiocb. It doesn't make
sense to use a request, as it's not an operation on the request itself.
It applies to the ring itself.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/filetable.c

@@ -58,11 +58,10 @@ void io_free_file_tables(struct io_file_table *table)
 	table->bitmap = NULL;
 }
 
-static int io_install_fixed_file(struct io_kiocb *req, struct file *file,
-				 unsigned int issue_flags, u32 slot_index)
+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_ring_ctx *ctx = req->ctx;
 	bool needs_switch = false;
 	struct io_fixed_file *file_slot;
 	int ret;
@@ -108,34 +107,71 @@ static int io_install_fixed_file(struct io_kiocb *req, struct file *file,
 	return ret;
 }
 
-/*
- * Note when io_fixed_fd_install() returns error value, it will ensure
- * fput() is called correspondingly.
- */
-int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags,
-			struct file *file, unsigned int file_slot)
+int __io_fixed_fd_install(struct io_ring_ctx *ctx, struct file *file,
+			  unsigned int file_slot)
 {
 	bool alloc_slot = file_slot == IORING_FILE_INDEX_ALLOC;
-	struct io_ring_ctx *ctx = req->ctx;
 	int ret;
 
-	io_ring_submit_lock(ctx, issue_flags);
-
 	if (alloc_slot) {
 		ret = io_file_bitmap_get(ctx);
 		if (unlikely(ret < 0))
-			goto err;
+			return ret;
 		file_slot = ret;
 	} else {
 		file_slot--;
 	}
 
-	ret = io_install_fixed_file(req, file, issue_flags, file_slot);
+	ret = io_install_fixed_file(ctx, file, file_slot);
 	if (!ret && alloc_slot)
 		ret = file_slot;
-err:
+	return ret;
+}
+/*
+ * Note when io_fixed_fd_install() returns error value, it will ensure
+ * fput() is called correspondingly.
+ */
+int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags,
+			struct file *file, unsigned int file_slot)
+{
+	struct io_ring_ctx *ctx = req->ctx;
+	int ret;
+
+	io_ring_submit_lock(ctx, issue_flags);
+	ret = __io_fixed_fd_install(ctx, file, file_slot);
 	io_ring_submit_unlock(ctx, issue_flags);
+
 	if (unlikely(ret < 0))
 		fput(file);
 	return ret;
 }
+
+int io_fixed_fd_remove(struct io_ring_ctx *ctx, unsigned int offset)
+{
+	struct io_fixed_file *file_slot;
+	struct file *file;
+	int ret;
+
+	if (unlikely(!ctx->file_data))
+		return -ENXIO;
+	if (offset >= ctx->nr_user_files)
+		return -EINVAL;
+	ret = io_rsrc_node_switch_start(ctx);
+	if (ret)
+		return ret;
+
+	offset = array_index_nospec(offset, ctx->nr_user_files);
+	file_slot = io_fixed_file_slot(&ctx->file_table, offset);
+	if (!file_slot->file_ptr)
+		return -EBADF;
+
+	file = (struct file *)(file_slot->file_ptr & FFS_MASK);
+	ret = io_queue_rsrc_removal(ctx->file_data, offset, ctx->rsrc_node, file);
+	if (ret)
+		return ret;
+
+	file_slot->file_ptr = 0;
+	io_file_bitmap_clear(&ctx->file_table, offset);
+	io_rsrc_node_switch(ctx, ctx->file_data);
+	return 0;
+}

io_uring/filetable.h

@@ -29,6 +29,9 @@ void io_free_file_tables(struct io_file_table *table);
 
 int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags,
 			struct file *file, unsigned int file_slot);
+int __io_fixed_fd_install(struct io_ring_ctx *ctx, struct file *file,
+				unsigned int file_slot);
+int io_fixed_fd_remove(struct io_ring_ctx *ctx, unsigned int offset);
 
 unsigned int io_file_get_flags(struct file *file);
 

io_uring/openclose.c

@@ -173,42 +173,15 @@ void io_open_cleanup(struct io_kiocb *req)
 		putname(open->filename);
 }
 
-int __io_close_fixed(struct io_kiocb *req, unsigned int issue_flags,
+int __io_close_fixed(struct io_ring_ctx *ctx, unsigned int issue_flags,
 		     unsigned int offset)
 {
-	struct io_ring_ctx *ctx = req->ctx;
-	struct io_fixed_file *file_slot;
-	struct file *file;
 	int ret;
 
 	io_ring_submit_lock(ctx, issue_flags);
-	ret = -ENXIO;
-	if (unlikely(!ctx->file_data))
-		goto out;
-	ret = -EINVAL;
-	if (offset >= ctx->nr_user_files)
-		goto out;
-	ret = io_rsrc_node_switch_start(ctx);
-	if (ret)
-		goto out;
-
-	offset = array_index_nospec(offset, ctx->nr_user_files);
-	file_slot = io_fixed_file_slot(&ctx->file_table, offset);
-	ret = -EBADF;
-	if (!file_slot->file_ptr)
-		goto out;
-
-	file = (struct file *)(file_slot->file_ptr & FFS_MASK);
-	ret = io_queue_rsrc_removal(ctx->file_data, offset, ctx->rsrc_node, file);
-	if (ret)
-		goto out;
-
-	file_slot->file_ptr = 0;
-	io_file_bitmap_clear(&ctx->file_table, offset);
-	io_rsrc_node_switch(ctx, ctx->file_data);
-	ret = 0;
-out:
+	ret = io_fixed_fd_remove(ctx, offset);
 	io_ring_submit_unlock(ctx, issue_flags);
+
 	return ret;
 }
 
@@ -216,7 +189,7 @@ static inline int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags)
 {
 	struct io_close *close = io_kiocb_to_cmd(req);
 
-	return __io_close_fixed(req, issue_flags, close->file_slot - 1);
+	return __io_close_fixed(req->ctx, issue_flags, close->file_slot - 1);
 }
 
 int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)

io_uring/openclose.h

 // SPDX-License-Identifier: GPL-2.0
 
-int __io_close_fixed(struct io_kiocb *req, unsigned int issue_flags,
+int __io_close_fixed(struct io_ring_ctx *ctx, unsigned int issue_flags,
 		     unsigned int offset);
 
 int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);

io_uring/rsrc.c

@@ -703,7 +703,7 @@ static int io_files_update_with_index_alloc(struct io_kiocb *req,
 		if (ret < 0)
 			break;
 		if (copy_to_user(&fds[done], &ret, sizeof(ret))) {
-			__io_close_fixed(req, issue_flags, ret);
+			__io_close_fixed(req->ctx, issue_flags, ret);
 			ret = -EFAULT;
 			break;
 		}