Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Wrapper functions for accessing the file_struct fd array.
4 */
5
6#ifndef __LINUX_FILE_H
7#define __LINUX_FILE_H
8
9#include <linux/compiler.h>
10#include <linux/types.h>
11#include <linux/posix_types.h>
12#include <linux/errno.h>
13#include <linux/cleanup.h>
14
15struct file;
16
17extern void fput(struct file *);
18
19struct file_operations;
20struct task_struct;
21struct vfsmount;
22struct dentry;
23struct inode;
24struct path;
25extern struct file *alloc_file_pseudo(struct inode *, struct vfsmount *,
26 const char *, int flags, const struct file_operations *);
27extern struct file *alloc_file_pseudo_noaccount(struct inode *, struct vfsmount *,
28 const char *, int flags, const struct file_operations *);
29extern struct file *alloc_file_clone(struct file *, int flags,
30 const struct file_operations *);
31
32static inline void fput_light(struct file *file, int fput_needed)
33{
34 if (fput_needed)
35 fput(file);
36}
37
38struct fd {
39 struct file *file;
40 unsigned int flags;
41};
42#define FDPUT_FPUT 1
43#define FDPUT_POS_UNLOCK 2
44
45static inline void fdput(struct fd fd)
46{
47 if (fd.flags & FDPUT_FPUT)
48 fput(fd.file);
49}
50
51extern struct file *fget(unsigned int fd);
52extern struct file *fget_raw(unsigned int fd);
53extern struct file *fget_task(struct task_struct *task, unsigned int fd);
54extern unsigned long __fdget(unsigned int fd);
55extern unsigned long __fdget_raw(unsigned int fd);
56extern unsigned long __fdget_pos(unsigned int fd);
57extern void __f_unlock_pos(struct file *);
58
59static inline struct fd __to_fd(unsigned long v)
60{
61 return (struct fd){(struct file *)(v & ~3),v & 3};
62}
63
64static inline struct fd fdget(unsigned int fd)
65{
66 return __to_fd(__fdget(fd));
67}
68
69static inline struct fd fdget_raw(unsigned int fd)
70{
71 return __to_fd(__fdget_raw(fd));
72}
73
74static inline struct fd fdget_pos(int fd)
75{
76 return __to_fd(__fdget_pos(fd));
77}
78
79static inline void fdput_pos(struct fd f)
80{
81 if (f.flags & FDPUT_POS_UNLOCK)
82 __f_unlock_pos(f.file);
83 fdput(f);
84}
85
86DEFINE_CLASS(fd, struct fd, fdput(_T), fdget(fd), int fd)
87DEFINE_CLASS(fd_raw, struct fd, fdput(_T), fdget_raw(fd), int fd)
88
89extern int f_dupfd(unsigned int from, struct file *file, unsigned flags);
90extern int replace_fd(unsigned fd, struct file *file, unsigned flags);
91extern void set_close_on_exec(unsigned int fd, int flag);
92extern bool get_close_on_exec(unsigned int fd);
93extern int __get_unused_fd_flags(unsigned flags, unsigned long nofile);
94extern int get_unused_fd_flags(unsigned flags);
95extern void put_unused_fd(unsigned int fd);
96
97DEFINE_CLASS(get_unused_fd, int, if (_T >= 0) put_unused_fd(_T),
98 get_unused_fd_flags(flags), unsigned flags)
99
100/*
101 * take_fd() will take care to set @fd to -EBADF ensuring that
102 * CLASS(get_unused_fd) won't call put_unused_fd(). This makes it
103 * easier to rely on CLASS(get_unused_fd):
104 *
105 * struct file *f;
106 *
107 * CLASS(get_unused_fd, fd)(O_CLOEXEC);
108 * if (fd < 0)
109 * return fd;
110 *
111 * f = dentry_open(&path, O_RDONLY, current_cred());
112 * if (IS_ERR(f))
113 * return PTR_ERR(f);
114 *
115 * fd_install(fd, f);
116 * return take_fd(fd);
117 */
118#define take_fd(fd) __get_and_null(fd, -EBADF)
119
120extern void fd_install(unsigned int fd, struct file *file);
121
122int receive_fd(struct file *file, int __user *ufd, unsigned int o_flags);
123
124int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags);
125
126extern void flush_delayed_fput(void);
127extern void __fput_sync(struct file *);
128
129extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max;
130
131#endif /* __LINUX_FILE_H */