Commit | Line | Data |
---|---|---|
b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | /* |
3 | * Wrapper functions for accessing the file_struct fd array. | |
4 | */ | |
5 | ||
6 | #ifndef __LINUX_FILE_H | |
7 | #define __LINUX_FILE_H | |
8 | ||
1da177e4 | 9 | #include <linux/compiler.h> |
0c9e63fd | 10 | #include <linux/types.h> |
9f3acc31 | 11 | #include <linux/posix_types.h> |
deefa7f3 | 12 | #include <linux/errno.h> |
54da6a09 | 13 | #include <linux/cleanup.h> |
257b1c2c | 14 | #include <linux/err.h> |
1da177e4 | 15 | |
9f3acc31 | 16 | struct file; |
8b7d91eb | 17 | |
b3c97528 | 18 | extern void fput(struct file *); |
1da177e4 | 19 | |
ce8d2cdf | 20 | struct file_operations; |
5e876fb4 | 21 | struct task_struct; |
ce8d2cdf DH |
22 | struct vfsmount; |
23 | struct dentry; | |
d93aa9d8 | 24 | struct inode; |
2c48b9c4 | 25 | struct path; |
d93aa9d8 AV |
26 | extern struct file *alloc_file_pseudo(struct inode *, struct vfsmount *, |
27 | const char *, int flags, const struct file_operations *); | |
bac0a9e5 CB |
28 | extern struct file *alloc_file_pseudo_noaccount(struct inode *, struct vfsmount *, |
29 | const char *, int flags, const struct file_operations *); | |
183266f2 AV |
30 | extern struct file *alloc_file_clone(struct file *, int flags, |
31 | const struct file_operations *); | |
ce8d2cdf | 32 | |
1da177e4 LT |
33 | static inline void fput_light(struct file *file, int fput_needed) |
34 | { | |
c2b3e74b | 35 | if (fput_needed) |
1da177e4 LT |
36 | fput(file); |
37 | } | |
38 | ||
88a2f646 AV |
39 | /* either a reference to struct file + flags |
40 | * (cloned vs. borrowed, pos locked), with | |
41 | * flags stored in lower bits of value, | |
42 | * or empty (represented by 0). | |
43 | */ | |
a5b470ba | 44 | struct fd { |
88a2f646 | 45 | unsigned long word; |
a5b470ba | 46 | }; |
9c225f26 LT |
47 | #define FDPUT_FPUT 1 |
48 | #define FDPUT_POS_UNLOCK 2 | |
a5b470ba | 49 | |
88a2f646 AV |
50 | #define fd_file(f) ((struct file *)((f).word & ~(FDPUT_FPUT|FDPUT_POS_UNLOCK))) |
51 | static inline bool fd_empty(struct fd f) | |
a5b470ba | 52 | { |
88a2f646 | 53 | return unlikely(!f.word); |
a5b470ba AV |
54 | } |
55 | ||
88a2f646 | 56 | #define EMPTY_FD (struct fd){0} |
de12c339 | 57 | static inline struct fd BORROWED_FD(struct file *f) |
a5b470ba | 58 | { |
de12c339 | 59 | return (struct fd){(unsigned long)f}; |
a5b470ba | 60 | } |
de12c339 | 61 | static inline struct fd CLONED_FD(struct file *f) |
bd2a31d5 | 62 | { |
de12c339 | 63 | return (struct fd){(unsigned long)f | FDPUT_FPUT}; |
bd2a31d5 | 64 | } |
2903ff01 | 65 | |
a5b470ba | 66 | static inline void fdput(struct fd fd) |
a5b470ba | 67 | { |
88a2f646 | 68 | if (fd.word & FDPUT_FPUT) |
1da91ea8 | 69 | fput(fd_file(fd)); |
a5b470ba AV |
70 | } |
71 | ||
b3c97528 | 72 | extern struct file *fget(unsigned int fd); |
bd2a31d5 | 73 | extern struct file *fget_raw(unsigned int fd); |
5e876fb4 | 74 | extern struct file *fget_task(struct task_struct *task, unsigned int fd); |
63b6df14 | 75 | extern void __f_unlock_pos(struct file *); |
a5b470ba | 76 | |
de12c339 AV |
77 | struct fd fdget(unsigned int fd); |
78 | struct fd fdget_raw(unsigned int fd); | |
79 | struct fd fdget_pos(unsigned int fd); | |
63b6df14 AV |
80 | |
81 | static inline void fdput_pos(struct fd f) | |
82 | { | |
88a2f646 | 83 | if (f.word & FDPUT_POS_UNLOCK) |
1da91ea8 | 84 | __f_unlock_pos(fd_file(f)); |
63b6df14 AV |
85 | fdput(f); |
86 | } | |
87 | ||
54da6a09 | 88 | DEFINE_CLASS(fd, struct fd, fdput(_T), fdget(fd), int fd) |
a0fde7ed | 89 | DEFINE_CLASS(fd_raw, struct fd, fdput(_T), fdget_raw(fd), int fd) |
54da6a09 | 90 | |
fe17f22d | 91 | extern int f_dupfd(unsigned int from, struct file *file, unsigned flags); |
8280d161 | 92 | extern int replace_fd(unsigned fd, struct file *file, unsigned flags); |
b3c97528 | 93 | extern void set_close_on_exec(unsigned int fd, int flag); |
fe17f22d | 94 | extern bool get_close_on_exec(unsigned int fd); |
4022e7af | 95 | extern int __get_unused_fd_flags(unsigned flags, unsigned long nofile); |
1a7bd226 | 96 | extern int get_unused_fd_flags(unsigned flags); |
b3c97528 | 97 | extern void put_unused_fd(unsigned int fd); |
1da177e4 | 98 | |
54da6a09 PZ |
99 | DEFINE_CLASS(get_unused_fd, int, if (_T >= 0) put_unused_fd(_T), |
100 | get_unused_fd_flags(flags), unsigned flags) | |
257b1c2c | 101 | DEFINE_FREE(fput, struct file *, if (!IS_ERR_OR_NULL(_T)) fput(_T)) |
54da6a09 | 102 | |
c6269149 CB |
103 | /* |
104 | * take_fd() will take care to set @fd to -EBADF ensuring that | |
105 | * CLASS(get_unused_fd) won't call put_unused_fd(). This makes it | |
106 | * easier to rely on CLASS(get_unused_fd): | |
107 | * | |
108 | * struct file *f; | |
109 | * | |
110 | * CLASS(get_unused_fd, fd)(O_CLOEXEC); | |
111 | * if (fd < 0) | |
112 | * return fd; | |
113 | * | |
114 | * f = dentry_open(&path, O_RDONLY, current_cred()); | |
115 | * if (IS_ERR(f)) | |
86509e38 | 116 | * return PTR_ERR(f); |
c6269149 CB |
117 | * |
118 | * fd_install(fd, f); | |
119 | * return take_fd(fd); | |
120 | */ | |
121 | #define take_fd(fd) __get_and_null(fd, -EBADF) | |
122 | ||
b3c97528 | 123 | extern void fd_install(unsigned int fd, struct file *file); |
1da177e4 | 124 | |
4e94ddfe | 125 | int receive_fd(struct file *file, int __user *ufd, unsigned int o_flags); |
9c930054 | 126 | |
42eb0d54 | 127 | int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags); |
66590610 | 128 | |
4a9d4b02 AV |
129 | extern void flush_delayed_fput(void); |
130 | extern void __fput_sync(struct file *); | |
131 | ||
2374c09b CH |
132 | extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max; |
133 | ||
1da177e4 | 134 | #endif /* __LINUX_FILE_H */ |