xref: /freebsd/sys/contrib/openzfs/lib/libzpool/zfs_debug.c (revision bd66c1b43e33540205dbc1187c2f2a15c58b57ba)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or https://opensource.org/licenses/CDDL-1.0.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
24  * Copyright (c) 2024, Rob Norris <robn@despairlabs.com>
25  */
26 
27 #include <sys/zfs_context.h>
28 
29 typedef struct zfs_dbgmsg {
30 	list_node_t		zdm_node;
31 	uint64_t		zdm_timestamp;
32 	uint_t			zdm_size;
33 	char			zdm_msg[]; /* variable length allocation */
34 } zfs_dbgmsg_t;
35 
36 static list_t zfs_dbgmsgs;
37 static kmutex_t zfs_dbgmsgs_lock;
38 
39 int zfs_dbgmsg_enable = B_TRUE;
40 
41 void
42 zfs_dbgmsg_init(void)
43 {
44 	list_create(&zfs_dbgmsgs, sizeof (zfs_dbgmsg_t),
45 	    offsetof(zfs_dbgmsg_t, zdm_node));
46 	mutex_init(&zfs_dbgmsgs_lock, NULL, MUTEX_DEFAULT, NULL);
47 }
48 
49 void
50 zfs_dbgmsg_fini(void)
51 {
52 	zfs_dbgmsg_t *zdm;
53 	while ((zdm = list_remove_head(&zfs_dbgmsgs)))
54 		umem_free(zdm, zdm->zdm_size);
55 	mutex_destroy(&zfs_dbgmsgs_lock);
56 }
57 
58 void
59 __set_error(const char *file, const char *func, int line, int err)
60 {
61 	if (zfs_flags & ZFS_DEBUG_SET_ERROR)
62 		__dprintf(B_FALSE, file, func, line, "error %lu",
63 		    (ulong_t)err);
64 }
65 
66 void
67 __zfs_dbgmsg(char *buf)
68 {
69 	uint_t size = sizeof (zfs_dbgmsg_t) + strlen(buf) + 1;
70 	zfs_dbgmsg_t *zdm = umem_zalloc(size, KM_SLEEP);
71 	zdm->zdm_size = size;
72 	zdm->zdm_timestamp = gethrestime_sec();
73 	strcpy(zdm->zdm_msg, buf);
74 
75 	mutex_enter(&zfs_dbgmsgs_lock);
76 	list_insert_tail(&zfs_dbgmsgs, zdm);
77 	mutex_exit(&zfs_dbgmsgs_lock);
78 }
79 
80 void
81 zfs_dbgmsg_print(int fd, const char *tag)
82 {
83 	ssize_t ret __attribute__((unused));
84 
85 	mutex_enter(&zfs_dbgmsgs_lock);
86 
87 	/*
88 	 * We use write() in this function instead of printf()
89 	 * so it is safe to call from a signal handler.
90 	 */
91 	ret = write(fd, "ZFS_DBGMSG(", 11);
92 	ret = write(fd, tag, strlen(tag));
93 	ret = write(fd, ") START:\n", 9);
94 
95 	for (zfs_dbgmsg_t *zdm = list_head(&zfs_dbgmsgs); zdm != NULL;
96 	    zdm = list_next(&zfs_dbgmsgs, zdm)) {
97 		ret = write(fd, zdm->zdm_msg, strlen(zdm->zdm_msg));
98 		ret = write(fd, "\n", 1);
99 	}
100 
101 	ret = write(fd, "ZFS_DBGMSG(", 11);
102 	ret = write(fd, tag, strlen(tag));
103 	ret = write(fd, ") END\n", 6);
104 
105 	mutex_exit(&zfs_dbgmsgs_lock);
106 }
107