xref: /linux/io_uring/filetable.h (revision 23c48a124b469cee2eb0c75e6d22d366d1caa118)
1 // SPDX-License-Identifier: GPL-2.0
2 #ifndef IOU_FILE_TABLE_H
3 #define IOU_FILE_TABLE_H
4 
5 #include <linux/file.h>
6 #include <linux/io_uring_types.h>
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 int __io_fixed_fd_install(struct io_ring_ctx *ctx, struct file *file,
31 				unsigned int file_slot);
32 int io_fixed_fd_remove(struct io_ring_ctx *ctx, unsigned int offset);
33 
34 int io_register_file_alloc_range(struct io_ring_ctx *ctx,
35 				 struct io_uring_file_index_range __user *arg);
36 
37 unsigned int io_file_get_flags(struct file *file);
38 
39 static inline void io_file_bitmap_clear(struct io_file_table *table, int bit)
40 {
41 	__clear_bit(bit, table->bitmap);
42 	table->alloc_hint = bit;
43 }
44 
45 static inline void io_file_bitmap_set(struct io_file_table *table, int bit)
46 {
47 	WARN_ON_ONCE(test_bit(bit, table->bitmap));
48 	__set_bit(bit, table->bitmap);
49 	table->alloc_hint = bit + 1;
50 }
51 
52 static inline struct io_fixed_file *
53 io_fixed_file_slot(struct io_file_table *table, unsigned i)
54 {
55 	return &table->files[i];
56 }
57 
58 static inline struct file *io_file_from_index(struct io_file_table *table,
59 					      int index)
60 {
61 	struct io_fixed_file *slot = io_fixed_file_slot(table, index);
62 
63 	return (struct file *) (slot->file_ptr & FFS_MASK);
64 }
65 
66 static inline void io_fixed_file_set(struct io_fixed_file *file_slot,
67 				     struct file *file)
68 {
69 	unsigned long file_ptr = (unsigned long) file;
70 
71 	file_ptr |= io_file_get_flags(file);
72 	file_slot->file_ptr = file_ptr;
73 }
74 
75 static inline void io_reset_alloc_hint(struct io_ring_ctx *ctx)
76 {
77 	ctx->file_table.alloc_hint = ctx->file_alloc_start;
78 }
79 
80 static inline void io_file_table_set_alloc_range(struct io_ring_ctx *ctx,
81 						 unsigned off, unsigned len)
82 {
83 	ctx->file_alloc_start = off;
84 	ctx->file_alloc_end = off + len;
85 	io_reset_alloc_hint(ctx);
86 }
87 
88 #endif
89