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>
27 #include <sys/trace_zfs.h>
29 typedef struct zfs_dbgmsg {
30 procfs_list_node_t zdm_node;
31 uint64_t zdm_timestamp;
33 char zdm_msg[1]; /* variable length allocation */
36 procfs_list_t zfs_dbgmsgs;
37 int zfs_dbgmsg_size = 0;
38 int zfs_dbgmsg_maxsize = 4<<20; /* 4MB */
41 * Internal ZFS debug messages are enabled by default.
43 * # Print debug messages
44 * cat /proc/spl/kstat/zfs/dbgmsg
46 * # Disable the kernel debug message log.
47 * echo 0 > /sys/module/zfs/parameters/zfs_dbgmsg_enable
49 * # Clear the kernel debug message log.
50 * echo 0 >/proc/spl/kstat/zfs/dbgmsg
52 int zfs_dbgmsg_enable = 1;
55 zfs_dbgmsg_show_header(struct seq_file *f)
57 seq_printf(f, "%-12s %-8s\n", "timestamp", "message");
62 zfs_dbgmsg_show(struct seq_file *f, void *p)
64 zfs_dbgmsg_t *zdm = (zfs_dbgmsg_t *)p;
65 seq_printf(f, "%-12llu %-s\n",
66 (u_longlong_t)zdm->zdm_timestamp, zdm->zdm_msg);
71 zfs_dbgmsg_purge(int max_size)
73 while (zfs_dbgmsg_size > max_size) {
74 zfs_dbgmsg_t *zdm = list_remove_head(&zfs_dbgmsgs.pl_list);
78 int size = zdm->zdm_size;
80 zfs_dbgmsg_size -= size;
85 zfs_dbgmsg_clear(procfs_list_t *procfs_list)
87 mutex_enter(&zfs_dbgmsgs.pl_lock);
89 mutex_exit(&zfs_dbgmsgs.pl_lock);
96 procfs_list_install("zfs",
102 zfs_dbgmsg_show_header,
104 offsetof(zfs_dbgmsg_t, zdm_node));
108 zfs_dbgmsg_fini(void)
110 procfs_list_uninstall(&zfs_dbgmsgs);
114 * TODO - decide how to make this permanent
117 procfs_list_destroy(&zfs_dbgmsgs);
122 __set_error(const char *file, const char *func, int line, int err)
127 * $ echo 512 >/sys/module/zfs/parameters/zfs_flags
129 if (zfs_flags & ZFS_DEBUG_SET_ERROR)
130 __dprintf(B_FALSE, file, func, line, "error %lu", err);
134 __zfs_dbgmsg(char *buf)
136 int size = sizeof (zfs_dbgmsg_t) + strlen(buf);
137 zfs_dbgmsg_t *zdm = kmem_zalloc(size, KM_SLEEP);
138 zdm->zdm_size = size;
139 zdm->zdm_timestamp = gethrestime_sec();
140 strcpy(zdm->zdm_msg, buf);
142 mutex_enter(&zfs_dbgmsgs.pl_lock);
143 procfs_list_add(&zfs_dbgmsgs, zdm);
144 zfs_dbgmsg_size += size;
145 zfs_dbgmsg_purge(MAX(zfs_dbgmsg_maxsize, 0));
146 mutex_exit(&zfs_dbgmsgs.pl_lock);
152 __dprintf(boolean_t dprint, const char *file, const char *func,
153 int line, const char *fmt, ...)
161 char *prefix = (dprint) ? "dprintf: " : "";
164 buf = kmem_alloc(size, KM_SLEEP);
167 * Get rid of annoying prefix to filename.
169 newfile = strrchr(file, '/');
170 if (newfile != NULL) {
171 newfile = newfile + 1; /* Get rid of leading / */
176 i = snprintf(buf, size, "%s%s:%d:%s(): ", prefix, newfile, line, func);
180 (void) vsnprintf(buf + i, size - i, fmt, adx);
185 * Get rid of trailing newline for dprintf logs.
187 if (dprint && buf[0] != '\0') {
188 nl = &buf[strlen(buf) - 1];
194 * To get this data enable the zfs__dprintf trace point as shown:
196 * # Enable zfs__dprintf tracepoint, clear the tracepoint ring buffer
197 * $ echo 1 > /sys/kernel/debug/tracing/events/zfs/enable
198 * $ echo 0 > /sys/kernel/debug/tracing/trace
200 * # Dump the ring buffer.
201 * $ cat /sys/kernel/debug/tracing/trace
203 DTRACE_PROBE1(zfs__dprintf, char *, buf);
208 * $ cat /proc/spl/kstat/zfs/dbgmsg
210 * To clear the buffer:
211 * $ echo 0 > /proc/spl/kstat/zfs/dbgmsg
215 kmem_free(buf, size);
221 zfs_dbgmsg_print(const char *tag)
223 ssize_t ret __attribute__((unused));
226 * We use write() in this function instead of printf()
227 * so it is safe to call from a signal handler.
229 ret = write(STDOUT_FILENO, "ZFS_DBGMSG(", 11);
230 ret = write(STDOUT_FILENO, tag, strlen(tag));
231 ret = write(STDOUT_FILENO, ") START:\n", 9);
233 mutex_enter(&zfs_dbgmsgs.pl_lock);
234 for (zfs_dbgmsg_t *zdm = list_head(&zfs_dbgmsgs.pl_list); zdm != NULL;
235 zdm = list_next(&zfs_dbgmsgs.pl_list, zdm)) {
236 ret = write(STDOUT_FILENO, zdm->zdm_msg,
237 strlen(zdm->zdm_msg));
238 ret = write(STDOUT_FILENO, "\n", 1);
241 ret = write(STDOUT_FILENO, "ZFS_DBGMSG(", 11);
242 ret = write(STDOUT_FILENO, tag, strlen(tag));
243 ret = write(STDOUT_FILENO, ") END\n", 6);
245 mutex_exit(&zfs_dbgmsgs.pl_lock);
250 module_param(zfs_dbgmsg_enable, int, 0644);
251 MODULE_PARM_DESC(zfs_dbgmsg_enable, "Enable ZFS debug message log");
253 module_param(zfs_dbgmsg_maxsize, int, 0644);
254 MODULE_PARM_DESC(zfs_dbgmsg_maxsize, "Maximum ZFS debug log size");