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 *, loff_t, ssize_t); 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 struct file *backing_tmpfile_open(const struct path *user_path, int flags, 26 const struct path *real_parentpath, 27 umode_t mode, const struct cred *cred); 28 ssize_t backing_file_read_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_write_iter(struct file *file, struct iov_iter *iter, 32 struct kiocb *iocb, int flags, 33 struct backing_file_ctx *ctx); 34 ssize_t backing_file_splice_read(struct file *in, loff_t *ppos, 35 struct pipe_inode_info *pipe, size_t len, 36 unsigned int flags, 37 struct backing_file_ctx *ctx); 38 ssize_t backing_file_splice_write(struct pipe_inode_info *pipe, 39 struct file *out, loff_t *ppos, size_t len, 40 unsigned int flags, 41 struct backing_file_ctx *ctx); 42 int backing_file_mmap(struct file *file, struct vm_area_struct *vma, 43 struct backing_file_ctx *ctx); 44 45 #endif /* _LINUX_BACKING_FILE_H */ 46