linux-stable/include/linux/backing-file.h
Miklos Szeredi 9a87907de3 ovl: implement tmpfile
Combine inode creation with opening a file.

There are six separate objects that are being set up: the backing inode,
dentry and file, and the overlay inode, dentry and file.  Cleanup in case
of an error is a bit of a challenge and is difficult to test, so careful
review is needed.

All tmpfile testcases except generic/509 now run/pass, and no regressions
are observed with full xfstests.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
2024-05-02 20:35:57 +02:00

46 lines
1.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Common helpers for stackable filesystems and backing files.
*
* Copyright (C) 2023 CTERA Networks.
*/
#ifndef _LINUX_BACKING_FILE_H
#define _LINUX_BACKING_FILE_H
#include <linux/file.h>
#include <linux/uio.h>
#include <linux/fs.h>
struct backing_file_ctx {
const struct cred *cred;
struct file *user_file;
void (*accessed)(struct file *);
void (*end_write)(struct file *);
};
struct file *backing_file_open(const struct path *user_path, int flags,
const struct path *real_path,
const struct cred *cred);
struct file *backing_tmpfile_open(const struct path *user_path, int flags,
const struct path *real_parentpath,
umode_t mode, const struct cred *cred);
ssize_t backing_file_read_iter(struct file *file, struct iov_iter *iter,
struct kiocb *iocb, int flags,
struct backing_file_ctx *ctx);
ssize_t backing_file_write_iter(struct file *file, struct iov_iter *iter,
struct kiocb *iocb, int flags,
struct backing_file_ctx *ctx);
ssize_t backing_file_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len,
unsigned int flags,
struct backing_file_ctx *ctx);
ssize_t backing_file_splice_write(struct pipe_inode_info *pipe,
struct file *out, loff_t *ppos, size_t len,
unsigned int flags,
struct backing_file_ctx *ctx);
int backing_file_mmap(struct file *file, struct vm_area_struct *vma,
struct backing_file_ctx *ctx);
#endif /* _LINUX_BACKING_FILE_H */