include/linux/file.h

   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
  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
  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
  57 static inline struct fd __to_fd(unsigned long v)
  58 {
  59         return (struct fd){(struct file *)(v & ~3),v & 3};
  60 }
  61
  62 static inline struct fd fdget(unsigned int fd)
  63 {
  64         return __to_fd(__fdget(fd));
  65 }
  66
  67 static inline struct fd fdget_raw(unsigned int fd)
  68 {
  69         return __to_fd(__fdget_raw(fd));
  70 }
  71
  72 static inline struct fd fdget_pos(int fd)
  73 {
  74         return __to_fd(__fdget_pos(fd));
  75 }
  76
  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
 104 int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags);
 105
 106 extern void flush_delayed_fput(void);
 107 extern void __fput_sync(struct file *);
 108
 109 extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max;
 110
 111 #endif /* __LINUX_FILE_H */