include/linux/backing-file.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Common helpers for stackable filesystems and backing files.
   4  *
   5  * Copyright (C) 2023 CTERA Networks.
   6  */
   7
   8 #ifndef _LINUX_BACKING_FILE_H
   9 #define _LINUX_BACKING_FILE_H
  10
  11 #include <linux/file.h>
  12 #include <linux/uio.h>
  13 #include <linux/fs.h>
  14
  15 struct backing_file_ctx {
  16         const struct cred *cred;
  17         struct file *user_file;
  18         void (*accessed)(struct file *);
  19         void (*end_write)(struct file *);
  20 };
  21
  22 struct file *backing_file_open(const struct path *user_path, int flags,
  23                                const struct path *real_path,
  24                                const struct cred *cred);
  25 ssize_t backing_file_read_iter(struct file *file, struct iov_iter *iter,
  26                                struct kiocb *iocb, int flags,
  27                                struct backing_file_ctx *ctx);
  28 ssize_t backing_file_write_iter(struct file *file, struct iov_iter *iter,
  29                                 struct kiocb *iocb, int flags,
  30                                 struct backing_file_ctx *ctx);
  31 ssize_t backing_file_splice_read(struct file *in, loff_t *ppos,
  32                                  struct pipe_inode_info *pipe, size_t len,
  33                                  unsigned int flags,
  34                                  struct backing_file_ctx *ctx);
  35 ssize_t backing_file_splice_write(struct pipe_inode_info *pipe,
  36                                   struct file *out, loff_t *ppos, size_t len,
  37                                   unsigned int flags,
  38                                   struct backing_file_ctx *ctx);
  39 int backing_file_mmap(struct file *file, struct vm_area_struct *vma,
  40                       struct backing_file_ctx *ctx);
  41
  42 #endif /* _LINUX_BACKING_FILE_H */