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");