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