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.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
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]
22 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
26 #include <sys/zfs_context.h>
28 typedef struct zfs_dbgmsg
{
29 procfs_list_node_t zdm_node
;
32 char zdm_msg
[1]; /* variable length allocation */
35 procfs_list_t zfs_dbgmsgs
;
36 int zfs_dbgmsg_size
= 0;
37 int zfs_dbgmsg_maxsize
= 4<<20; /* 4MB */
40 * Internal ZFS debug messages are enabled by default.
42 * # Print debug messages
43 * cat /proc/spl/kstat/zfs/dbgmsg
45 * # Disable the kernel debug message log.
46 * echo 0 > /sys/module/zfs/parameters/zfs_dbgmsg_enable
48 * # Clear the kernel debug message log.
49 * echo 0 >/proc/spl/kstat/zfs/dbgmsg
51 int zfs_dbgmsg_enable
= 1;
54 zfs_dbgmsg_show_header(struct seq_file
*f
)
56 seq_printf(f
, "%-12s %-8s\n", "timestamp", "message");
61 zfs_dbgmsg_show(struct seq_file
*f
, void *p
)
63 zfs_dbgmsg_t
*zdm
= (zfs_dbgmsg_t
*)p
;
64 seq_printf(f
, "%-12llu %-s\n",
65 (u_longlong_t
)zdm
->zdm_timestamp
, zdm
->zdm_msg
);
70 zfs_dbgmsg_purge(int max_size
)
72 while (zfs_dbgmsg_size
> max_size
) {
73 zfs_dbgmsg_t
*zdm
= list_remove_head(&zfs_dbgmsgs
.pl_list
);
77 int size
= zdm
->zdm_size
;
79 zfs_dbgmsg_size
-= size
;
84 zfs_dbgmsg_clear(procfs_list_t
*procfs_list
)
86 mutex_enter(&zfs_dbgmsgs
.pl_lock
);
88 mutex_exit(&zfs_dbgmsgs
.pl_lock
);
95 procfs_list_install("zfs",
99 zfs_dbgmsg_show_header
,
101 offsetof(zfs_dbgmsg_t
, zdm_node
));
105 zfs_dbgmsg_fini(void)
107 procfs_list_uninstall(&zfs_dbgmsgs
);
111 * TODO - decide how to make this permanent
114 procfs_list_destroy(&zfs_dbgmsgs
);
119 __set_error(const char *file
, const char *func
, int line
, int err
)
124 * $ echo 512 >/sys/module/zfs/parameters/zfs_flags
126 if (zfs_flags
& ZFS_DEBUG_SET_ERROR
)
127 __dprintf(B_FALSE
, file
, func
, line
, "error %lu", err
);
131 __zfs_dbgmsg(char *buf
)
133 int size
= sizeof (zfs_dbgmsg_t
) + strlen(buf
);
134 zfs_dbgmsg_t
*zdm
= kmem_zalloc(size
, KM_SLEEP
);
135 zdm
->zdm_size
= size
;
136 zdm
->zdm_timestamp
= gethrestime_sec();
137 strcpy(zdm
->zdm_msg
, buf
);
139 mutex_enter(&zfs_dbgmsgs
.pl_lock
);
140 procfs_list_add(&zfs_dbgmsgs
, zdm
);
141 zfs_dbgmsg_size
+= size
;
142 zfs_dbgmsg_purge(MAX(zfs_dbgmsg_maxsize
, 0));
143 mutex_exit(&zfs_dbgmsgs
.pl_lock
);
149 __dprintf(boolean_t dprint
, const char *file
, const char *func
,
150 int line
, const char *fmt
, ...)
158 char *prefix
= (dprint
) ? "dprintf: " : "";
161 buf
= kmem_alloc(size
, KM_SLEEP
);
164 * Get rid of annoying prefix to filename.
166 newfile
= strrchr(file
, '/');
167 if (newfile
!= NULL
) {
168 newfile
= newfile
+ 1; /* Get rid of leading / */
173 i
= snprintf(buf
, size
, "%s%s:%d:%s(): ", prefix
, newfile
, line
, func
);
177 (void) vsnprintf(buf
+ i
, size
- i
, fmt
, adx
);
182 * Get rid of trailing newline for dprintf logs.
184 if (dprint
&& buf
[0] != '\0') {
185 nl
= &buf
[strlen(buf
) - 1];
191 * To get this data enable the zfs__dprintf trace point as shown:
193 * # Enable zfs__dprintf tracepoint, clear the tracepoint ring buffer
194 * $ echo 1 > /sys/kernel/debug/tracing/events/zfs/enable
195 * $ echo 0 > /sys/kernel/debug/tracing/trace
197 * # Dump the ring buffer.
198 * $ cat /sys/kernel/debug/tracing/trace
200 DTRACE_PROBE1(zfs__dprintf
, char *, buf
);
205 * $ cat /proc/spl/kstat/zfs/dbgmsg
207 * To clear the buffer:
208 * $ echo 0 > /proc/spl/kstat/zfs/dbgmsg
212 kmem_free(buf
, size
);
218 zfs_dbgmsg_print(const char *tag
)
220 ssize_t ret
__attribute__((unused
));
223 * We use write() in this function instead of printf()
224 * so it is safe to call from a signal handler.
226 ret
= write(STDOUT_FILENO
, "ZFS_DBGMSG(", 11);
227 ret
= write(STDOUT_FILENO
, tag
, strlen(tag
));
228 ret
= write(STDOUT_FILENO
, ") START:\n", 9);
230 mutex_enter(&zfs_dbgmsgs
.pl_lock
);
231 for (zfs_dbgmsg_t
*zdm
= list_head(&zfs_dbgmsgs
.pl_list
); zdm
!= NULL
;
232 zdm
= list_next(&zfs_dbgmsgs
.pl_list
, zdm
)) {
233 ret
= write(STDOUT_FILENO
, zdm
->zdm_msg
,
234 strlen(zdm
->zdm_msg
));
235 ret
= write(STDOUT_FILENO
, "\n", 1);
238 ret
= write(STDOUT_FILENO
, "ZFS_DBGMSG(", 11);
239 ret
= write(STDOUT_FILENO
, tag
, strlen(tag
));
240 ret
= write(STDOUT_FILENO
, ") END\n", 6);
242 mutex_exit(&zfs_dbgmsgs
.pl_lock
);
247 module_param(zfs_dbgmsg_enable
, int, 0644);
248 MODULE_PARM_DESC(zfs_dbgmsg_enable
, "Enable ZFS debug message log");
250 module_param(zfs_dbgmsg_maxsize
, int, 0644);
251 MODULE_PARM_DESC(zfs_dbgmsg_maxsize
, "Maximum ZFS debug log size");