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
15 struct file;
16
17 extern void fput(struct file *);
18
19 struct file_operations;
20 struct task_struct;
21 struct vfsmount;
22 struct dentry;
23 struct inode;
24 struct path;
25 extern struct file *alloc_file_pseudo(struct inode *, struct vfsmount *,
26 const char *, int flags, const struct file_operations *);
27 extern struct file *alloc_file_clone(struct file *, int flags,
28 const struct file_operations *);
29
fput_light(struct file * file,int fput_needed)30 static inline void fput_light(struct file *file, int fput_needed)
31 {
32 if (fput_needed)
33 fput(file);
34 }
35
36 struct fd {
37 struct file *file;
38 unsigned int flags;
39 };
40 #define FDPUT_FPUT 1
41 #define FDPUT_POS_UNLOCK 2
42
fdput(struct fd fd)43 static inline void fdput(struct fd fd)
44 {
45 if (fd.flags & FDPUT_FPUT)
46 fput(fd.file);
47 }
48
49 extern struct file *fget(unsigned int fd);
50 extern struct file *fget_raw(unsigned int fd);
51 extern struct file *fget_task(struct task_struct *task, unsigned int fd);
52 extern unsigned long __fdget(unsigned int fd);
53 extern unsigned long __fdget_raw(unsigned int fd);
54 extern unsigned long __fdget_pos(unsigned int fd);
55 extern void __f_unlock_pos(struct file *);
56
__to_fd(unsigned long v)57 static inline struct fd __to_fd(unsigned long v)
58 {
59 return (struct fd){(struct file *)(v & ~3),v & 3};
60 }
61
fdget(unsigned int fd)62 static inline struct fd fdget(unsigned int fd)
63 {
64 return __to_fd(__fdget(fd));
65 }
66
fdget_raw(unsigned int fd)67 static inline struct fd fdget_raw(unsigned int fd)
68 {
69 return __to_fd(__fdget_raw(fd));
70 }
71
fdget_pos(int fd)72 static inline struct fd fdget_pos(int fd)
73 {
74 return __to_fd(__fdget_pos(fd));
75 }
76
fdput_pos(struct fd f)77 static inline void fdput_pos(struct fd f)
78 {
79 if (f.flags & FDPUT_POS_UNLOCK)
80 __f_unlock_pos(f.file);
81 fdput(f);
82 }
83
84 DEFINE_CLASS(fd, struct fd, fdput(_T), fdget(fd), int fd)
85
86 extern int f_dupfd(unsigned int from, struct file *file, unsigned flags);
87 extern int replace_fd(unsigned fd, struct file *file, unsigned flags);
88 extern void set_close_on_exec(unsigned int fd, int flag);
89 extern bool get_close_on_exec(unsigned int fd);
90 extern int __get_unused_fd_flags(unsigned flags, unsigned long nofile);
91 extern int get_unused_fd_flags(unsigned flags);
92 extern void put_unused_fd(unsigned int fd);
93
94 DEFINE_CLASS(get_unused_fd, int, if (_T >= 0) put_unused_fd(_T),
95 get_unused_fd_flags(flags), unsigned flags)
96
97 extern void fd_install(unsigned int fd, struct file *file);
98
99 extern int __receive_fd(struct file *file, int __user *ufd,
100 unsigned int o_flags);
101
102 extern int receive_fd(struct file *file, unsigned int o_flags);
103
receive_fd_user(struct file * file,int __user * ufd,unsigned int o_flags)104 static inline int receive_fd_user(struct file *file, int __user *ufd,
105 unsigned int o_flags)
106 {
107 if (ufd == NULL)
108 return -EFAULT;
109 return __receive_fd(file, ufd, o_flags);
110 }
111 int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags);
112
113 extern void flush_delayed_fput(void);
114 extern void __fput_sync(struct file *);
115
116 extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max;
117
118 #endif /* __LINUX_FILE_H */
119