1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_THREAD_WITH_FILE_H
#define _BCACHEFS_THREAD_WITH_FILE_H
#include "thread_with_file_types.h"
/*
* Thread with file: Run a kthread and connect it to a file descriptor, so that
* it can be interacted with via fd read/write methods and closing the file
* descriptor stops the kthread.
*
* We have two different APIs:
*
* thread_with_file, the low level version.
* You get to define the full file_operations, including your release function,
* which means that you must call bch2_thread_with_file_exit() from your
* .release method
*
* thread_with_stdio, the higher level version
* This implements full piping of input and output, including .poll.
*
* Notes on behaviour:
* - kthread shutdown behaves like writing or reading from a pipe that has been
* closed
* - Input and output buffers are 4096 bytes, although buffers may in some
* situations slightly exceed that limit so as to avoid chopping off a
* message in the middle in nonblocking mode.
* - Input/output buffers are lazily allocated, with GFP_NOWAIT allocations -
* should be fine but might change in future revisions.
* - Output buffer may grow past 4096 bytes to deal with messages that are
* bigger than 4096 bytes
* - Writing may be done blocking or nonblocking; in nonblocking mode, we only
* drop entire messages.
*
* To write, use stdio_redirect_printf()
* To read, use stdio_redirect_read() or stdio_redirect_readline()
*/
struct task_struct;
struct thread_with_file {
struct task_struct *task;
int ret;
bool done;
};
void bch2_thread_with_file_exit(struct thread_with_file *);
int bch2_run_thread_with_file(struct thread_with_file *,
const struct file_operations *,
int (*fn)(void *));
struct thread_with_stdio;
struct thread_with_stdio_ops {
void (*exit)(struct thread_with_stdio *);
int (*fn)(struct thread_with_stdio *);
long (*unlocked_ioctl)(struct thread_with_stdio *, unsigned int, unsigned long);
};
struct thread_with_stdio {
struct thread_with_file thr;
struct stdio_redirect stdio;
const struct thread_with_stdio_ops *ops;
};
int bch2_run_thread_with_stdio(struct thread_with_stdio *,
const struct thread_with_stdio_ops *);
int bch2_run_thread_with_stdout(struct thread_with_stdio *,
const struct thread_with_stdio_ops *);
int bch2_stdio_redirect_read(struct stdio_redirect *, char *, size_t);
int bch2_stdio_redirect_readline(struct stdio_redirect *, char *, size_t);
__printf(3, 0) ssize_t bch2_stdio_redirect_vprintf(struct stdio_redirect *, bool, const char *, va_list);
__printf(3, 4) ssize_t bch2_stdio_redirect_printf(struct stdio_redirect *, bool, const char *, ...);
#endif /* _BCACHEFS_THREAD_WITH_FILE_H */
|
