From 453b329be5eacfc48dd43035af82bc7f28ecfedf Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 24 May 2022 21:43:10 -0600
Subject: io_uring: separate out file table handling code

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 io_uring/filetable.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 io_uring/filetable.c

(limited to 'io_uring/filetable.c')

diff --git a/io_uring/filetable.c b/io_uring/filetable.c
new file mode 100644
index 000000000000..560629a93c04
--- /dev/null
+++ b/io_uring/filetable.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/file.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/io_uring.h>
+
+#include <uapi/linux/io_uring.h>
+
+#include "io_uring_types.h"
+#include "io_uring.h"
+
+int io_file_bitmap_get(struct io_ring_ctx *ctx)
+{
+	struct io_file_table *table = &ctx->file_table;
+	unsigned long nr = ctx->nr_user_files;
+	int ret;
+
+	do {
+		ret = find_next_zero_bit(table->bitmap, nr, table->alloc_hint);
+		if (ret != nr)
+			return ret;
+
+		if (!table->alloc_hint)
+			break;
+
+		nr = table->alloc_hint;
+		table->alloc_hint = 0;
+	} while (1);
+
+	return -ENFILE;
+}
+
+bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files)
+{
+	table->files = kvcalloc(nr_files, sizeof(table->files[0]),
+				GFP_KERNEL_ACCOUNT);
+	if (unlikely(!table->files))
+		return false;
+
+	table->bitmap = bitmap_zalloc(nr_files, GFP_KERNEL_ACCOUNT);
+	if (unlikely(!table->bitmap)) {
+		kvfree(table->files);
+		return false;
+	}
+
+	return true;
+}
+
+void io_free_file_tables(struct io_file_table *table)
+{
+	kvfree(table->files);
+	bitmap_free(table->bitmap);
+	table->files = NULL;
+	table->bitmap = NULL;
+}
-- 
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