Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging
[qemu.git] / tools / virtiofsd / fuse_log.h
1 /*
2 * FUSE: Filesystem in Userspace
3 * Copyright (C) 2019 Red Hat, Inc.
4 *
5 * This program can be distributed under the terms of the GNU LGPLv2.
6 * See the file COPYING.LIB.
7 */
8
9 #ifndef FUSE_LOG_H_
10 #define FUSE_LOG_H_
11
12 /** @file
13 *
14 * This file defines the logging interface of FUSE
15 */
16
17
18 /**
19 * Log severity level
20 *
21 * These levels correspond to syslog(2) log levels since they are widely used.
22 */
23 enum fuse_log_level {
24 FUSE_LOG_EMERG,
25 FUSE_LOG_ALERT,
26 FUSE_LOG_CRIT,
27 FUSE_LOG_ERR,
28 FUSE_LOG_WARNING,
29 FUSE_LOG_NOTICE,
30 FUSE_LOG_INFO,
31 FUSE_LOG_DEBUG
32 };
33
34 /**
35 * Log message handler function.
36 *
37 * This function must be thread-safe. It may be called from any libfuse
38 * function, including fuse_parse_cmdline() and other functions invoked before
39 * a FUSE filesystem is created.
40 *
41 * Install a custom log message handler function using fuse_set_log_func().
42 *
43 * @param level log severity level
44 * @param fmt sprintf-style format string including newline
45 * @param ap format string arguments
46 */
47 typedef void (*fuse_log_func_t)(enum fuse_log_level level, const char *fmt,
48 va_list ap);
49
50 /**
51 * Install a custom log handler function.
52 *
53 * Log messages are emitted by libfuse functions to report errors and debug
54 * information. Messages are printed to stderr by default but this can be
55 * overridden by installing a custom log message handler function.
56 *
57 * The log message handler function is global and affects all FUSE filesystems
58 * created within this process.
59 *
60 * @param func a custom log message handler function or NULL to revert to
61 * the default
62 */
63 void fuse_set_log_func(fuse_log_func_t func);
64
65 /**
66 * Emit a log message
67 *
68 * @param level severity level (FUSE_LOG_ERR, FUSE_LOG_DEBUG, etc)
69 * @param fmt sprintf-style format string including newline
70 */
71 void fuse_log(enum fuse_log_level level, const char *fmt, ...);
72
73 #endif /* FUSE_LOG_H_ */