LXR linux/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
  14struct file;
  15
  16extern void fput(struct file *);
  17extern void fput_many(struct file *, unsigned int);
  18
  19struct file_operations;
  20struct task_struct;
  21struct vfsmount;
  22struct dentry;
  23struct inode;
  24struct path;
  25extern struct file *alloc_file_pseudo(struct inode *, struct vfsmount *,
  26        const char *, int flags, const struct file_operations *);
  27extern struct file *alloc_file_clone(struct file *, int flags,
  28        const struct file_operations *);
  29
  30static inline void fput_light(struct file *file, int fput_needed)
  31{
  32        if (fput_needed)
  33                fput(file);
  34}
  35
  36struct fd {
  37        struct file *file;
  38        unsigned int flags;
  39};
  40#define FDPUT_FPUT       1
  41#define FDPUT_POS_UNLOCK 2
  42
  43static inline void fdput(struct fd fd)
  44{
  45        if (fd.flags & FDPUT_FPUT)
  46                fput(fd.file);
  47}
  48
  49extern struct file *fget(unsigned int fd);
  50extern struct file *fget_many(unsigned int fd, unsigned int refs);
  51extern struct file *fget_raw(unsigned int fd);
  52extern struct file *fget_task(struct task_struct *task, unsigned int fd);
  53extern unsigned long __fdget(unsigned int fd);
  54extern unsigned long __fdget_raw(unsigned int fd);
  55extern unsigned long __fdget_pos(unsigned int fd);
  56extern void __f_unlock_pos(struct file *);
  57
  58static inline struct fd __to_fd(unsigned long v)
  59{
  60        return (struct fd){(struct file *)(v & ~3),v & 3};
  61}
  62
  63static inline struct fd fdget(unsigned int fd)
  64{
  65        return __to_fd(__fdget(fd));
  66}
  67
  68static inline struct fd fdget_raw(unsigned int fd)
  69{
  70        return __to_fd(__fdget_raw(fd));
  71}
  72
  73static inline struct fd fdget_pos(int fd)
  74{
  75        return __to_fd(__fdget_pos(fd));
  76}
  77
  78static inline void fdput_pos(struct fd f)
  79{
  80        if (f.flags & FDPUT_POS_UNLOCK)
  81                __f_unlock_pos(f.file);
  82        fdput(f);
  83}
  84
  85extern int f_dupfd(unsigned int from, struct file *file, unsigned flags);
  86extern int replace_fd(unsigned fd, struct file *file, unsigned flags);
  87extern void set_close_on_exec(unsigned int fd, int flag);
  88extern bool get_close_on_exec(unsigned int fd);
  89extern int __get_unused_fd_flags(unsigned flags, unsigned long nofile);
  90extern int get_unused_fd_flags(unsigned flags);
  91extern void put_unused_fd(unsigned int fd);
  92
  93extern void fd_install(unsigned int fd, struct file *file);
  94
  95extern int __receive_fd(struct file *file, int __user *ufd,
  96                        unsigned int o_flags);
  97static inline int receive_fd_user(struct file *file, int __user *ufd,
  98                                  unsigned int o_flags)
  99{
 100        if (ufd == NULL)
 101                return -EFAULT;
 102        return __receive_fd(file, ufd, o_flags);
 103}
 104static inline int receive_fd(struct file *file, unsigned int o_flags)
 105{
 106        return __receive_fd(file, NULL, o_flags);
 107}
 108int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags);
 109
 110extern void flush_delayed_fput(void);
 111extern void __fput_sync(struct file *);
 112
 113extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max;
 114
 115#endif /* __LINUX_FILE_H */
 116