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 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 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 56 static inline struct fd __to_fd(unsigned long v) 57 { 58 return (struct fd){(struct file *)(v & ~3),v & 3}; 59 } 60 61 static inline struct fd fdget(unsigned int fd) 62 { 63 return __to_fd(__fdget(fd)); 64 } 65 66 static inline struct fd fdget_raw(unsigned int fd) 67 { 68 return __to_fd(__fdget_raw(fd)); 69 } 70 71 static inline struct fd fdget_pos(int fd) 72 { 73 return __to_fd(__fdget_pos(fd)); 74 } 75 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 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