xref: /openbmc/linux/io_uring/filetable.h (revision ab1c84d8)
1 // SPDX-License-Identifier: GPL-2.0
2 #ifndef IOU_FILE_TABLE_H
3 #define IOU_FILE_TABLE_H
4 
5 struct io_ring_ctx;
6 struct io_kiocb;
7 
8 /*
9  * FFS_SCM is only available on 64-bit archs, for 32-bit we just define it as 0
10  * and define IO_URING_SCM_ALL. For this case, we use SCM for all files as we
11  * can't safely always dereference the file when the task has exited and ring
12  * cleanup is done. If a file is tracked and part of SCM, then unix gc on
13  * process exit may reap it before __io_sqe_files_unregister() is run.
14  */
15 #define FFS_NOWAIT		0x1UL
16 #define FFS_ISREG		0x2UL
17 #if defined(CONFIG_64BIT)
18 #define FFS_SCM			0x4UL
19 #else
20 #define IO_URING_SCM_ALL
21 #define FFS_SCM			0x0UL
22 #endif
23 #define FFS_MASK		~(FFS_NOWAIT|FFS_ISREG|FFS_SCM)
24 
25 bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files);
26 void io_free_file_tables(struct io_file_table *table);
27 
28 int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags,
29 			struct file *file, unsigned int file_slot);
30 
31 unsigned int io_file_get_flags(struct file *file);
32 
33 static inline void io_file_bitmap_clear(struct io_file_table *table, int bit)
34 {
35 	__clear_bit(bit, table->bitmap);
36 	table->alloc_hint = bit;
37 }
38 
39 static inline void io_file_bitmap_set(struct io_file_table *table, int bit)
40 {
41 	WARN_ON_ONCE(test_bit(bit, table->bitmap));
42 	__set_bit(bit, table->bitmap);
43 	table->alloc_hint = bit + 1;
44 }
45 
46 static inline struct io_fixed_file *
47 io_fixed_file_slot(struct io_file_table *table, unsigned i)
48 {
49 	return &table->files[i];
50 }
51 
52 static inline struct file *io_file_from_index(struct io_file_table *table,
53 					      int index)
54 {
55 	struct io_fixed_file *slot = io_fixed_file_slot(table, index);
56 
57 	return (struct file *) (slot->file_ptr & FFS_MASK);
58 }
59 
60 static inline void io_fixed_file_set(struct io_fixed_file *file_slot,
61 				     struct file *file)
62 {
63 	unsigned long file_ptr = (unsigned long) file;
64 
65 	file_ptr |= io_file_get_flags(file);
66 	file_slot->file_ptr = file_ptr;
67 }
68 
69 #endif
70