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 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
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