xref: /linux/include/linux/file.h (revision 44f57d78)
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 
13 struct file;
14 
15 extern void fput(struct file *);
16 extern void fput_many(struct file *, unsigned int);
17 
18 struct file_operations;
19 struct vfsmount;
20 struct dentry;
21 struct inode;
22 struct path;
23 extern struct file *alloc_file_pseudo(struct inode *, struct vfsmount *,
24 	const char *, int flags, const struct file_operations *);
25 extern struct file *alloc_file_clone(struct file *, int flags,
26 	const struct file_operations *);
27 
28 static inline void fput_light(struct file *file, int fput_needed)
29 {
30 	if (fput_needed)
31 		fput(file);
32 }
33 
34 struct fd {
35 	struct file *file;
36 	unsigned int flags;
37 };
38 #define FDPUT_FPUT       1
39 #define FDPUT_POS_UNLOCK 2
40 
41 static inline void fdput(struct fd fd)
42 {
43 	if (fd.flags & FDPUT_FPUT)
44 		fput(fd.file);
45 }
46 
47 extern struct file *fget(unsigned int fd);
48 extern struct file *fget_many(unsigned int fd, unsigned int refs);
49 extern struct file *fget_raw(unsigned int fd);
50 extern unsigned long __fdget(unsigned int fd);
51 extern unsigned long __fdget_raw(unsigned int fd);
52 extern unsigned long __fdget_pos(unsigned int fd);
53 extern void __f_unlock_pos(struct file *);
54 
55 static inline struct fd __to_fd(unsigned long v)
56 {
57 	return (struct fd){(struct file *)(v & ~3),v & 3};
58 }
59 
60 static inline struct fd fdget(unsigned int fd)
61 {
62 	return __to_fd(__fdget(fd));
63 }
64 
65 static inline struct fd fdget_raw(unsigned int fd)
66 {
67 	return __to_fd(__fdget_raw(fd));
68 }
69 
70 static inline struct fd fdget_pos(int fd)
71 {
72 	return __to_fd(__fdget_pos(fd));
73 }
74 
75 static inline void fdput_pos(struct fd f)
76 {
77 	if (f.flags & FDPUT_POS_UNLOCK)
78 		__f_unlock_pos(f.file);
79 	fdput(f);
80 }
81 
82 extern int f_dupfd(unsigned int from, struct file *file, unsigned flags);
83 extern int replace_fd(unsigned fd, struct file *file, unsigned flags);
84 extern void set_close_on_exec(unsigned int fd, int flag);
85 extern bool get_close_on_exec(unsigned int fd);
86 extern int get_unused_fd_flags(unsigned flags);
87 extern void put_unused_fd(unsigned int fd);
88 
89 extern void fd_install(unsigned int fd, struct file *file);
90 
91 extern void flush_delayed_fput(void);
92 extern void __fput_sync(struct file *);
93 
94 #endif /* __LINUX_FILE_H */
95