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 */ 25 26 #include <sys/zfs_context.h> 27 #include <sys/trace_zfs.h> 28 29 typedef struct zfs_dbgmsg { 30 procfs_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 procfs_list_t zfs_dbgmsgs; 37 static uint_t zfs_dbgmsg_size = 0; 38 static uint_t zfs_dbgmsg_maxsize = 4<<20; /* 4MB */ 39 40 /* 41 * Internal ZFS debug messages are enabled by default. 42 * 43 * # Print debug messages 44 * cat /proc/spl/kstat/zfs/dbgmsg 45 * 46 * # Disable the kernel debug message log. 47 * echo 0 > /sys/module/zfs/parameters/zfs_dbgmsg_enable 48 * 49 * # Clear the kernel debug message log. 50 * echo 0 >/proc/spl/kstat/zfs/dbgmsg 51 */ 52 int zfs_dbgmsg_enable = B_TRUE; 53 54 static int 55 zfs_dbgmsg_show_header(struct seq_file *f) 56 { 57 seq_printf(f, "%-12s %-8s\n", "timestamp", "message"); 58 return (0); 59 } 60 61 static int 62 zfs_dbgmsg_show(struct seq_file *f, void *p) 63 { 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); 67 return (0); 68 } 69 70 static void 71 zfs_dbgmsg_purge(uint_t max_size) 72 { 73 while (zfs_dbgmsg_size > max_size) { 74 zfs_dbgmsg_t *zdm = list_remove_head(&zfs_dbgmsgs.pl_list); 75 if (zdm == NULL) 76 return; 77 78 uint_t size = zdm->zdm_size; 79 kmem_free(zdm, size); 80 zfs_dbgmsg_size -= size; 81 } 82 } 83 84 static int 85 zfs_dbgmsg_clear(procfs_list_t *procfs_list) 86 { 87 (void) procfs_list; 88 mutex_enter(&zfs_dbgmsgs.pl_lock); 89 zfs_dbgmsg_purge(0); 90 mutex_exit(&zfs_dbgmsgs.pl_lock); 91 return (0); 92 } 93 94 void 95 zfs_dbgmsg_init(void) 96 { 97 procfs_list_install("zfs", 98 NULL, 99 "dbgmsg", 100 0600, 101 &zfs_dbgmsgs, 102 zfs_dbgmsg_show, 103 zfs_dbgmsg_show_header, 104 zfs_dbgmsg_clear, 105 offsetof(zfs_dbgmsg_t, zdm_node)); 106 } 107 108 void 109 zfs_dbgmsg_fini(void) 110 { 111 procfs_list_uninstall(&zfs_dbgmsgs); 112 zfs_dbgmsg_purge(0); 113 114 procfs_list_destroy(&zfs_dbgmsgs); 115 } 116 117 void 118 __set_error(const char *file, const char *func, int line, int err) 119 { 120 /* 121 * To enable this: 122 * 123 * $ echo 512 >/sys/module/zfs/parameters/zfs_flags 124 */ 125 if (zfs_flags & ZFS_DEBUG_SET_ERROR) 126 __dprintf(B_FALSE, file, func, line, "error %lu", 127 (ulong_t)err); 128 } 129 130 void 131 __zfs_dbgmsg(char *buf) 132 { 133 uint_t size = sizeof (zfs_dbgmsg_t) + strlen(buf) + 1; 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); 138 139 mutex_enter(&zfs_dbgmsgs.pl_lock); 140 procfs_list_add(&zfs_dbgmsgs, zdm); 141 zfs_dbgmsg_size += size; 142 zfs_dbgmsg_purge(zfs_dbgmsg_maxsize); 143 mutex_exit(&zfs_dbgmsgs.pl_lock); 144 } 145 146 void 147 __dprintf(boolean_t dprint, const char *file, const char *func, 148 int line, const char *fmt, ...) 149 { 150 const char *newfile; 151 va_list adx; 152 size_t size; 153 char *buf; 154 char *nl; 155 int i; 156 char *prefix = (dprint) ? "dprintf: " : ""; 157 158 size = 1024; 159 buf = kmem_alloc(size, KM_SLEEP); 160 161 /* 162 * Get rid of annoying prefix to filename. 163 */ 164 newfile = strrchr(file, '/'); 165 if (newfile != NULL) { 166 newfile = newfile + 1; /* Get rid of leading / */ 167 } else { 168 newfile = file; 169 } 170 171 i = snprintf(buf, size, "%px %s%s:%d:%s(): ", 172 curthread, prefix, newfile, line, func); 173 174 if (i < size) { 175 va_start(adx, fmt); 176 (void) vsnprintf(buf + i, size - i, fmt, adx); 177 va_end(adx); 178 } 179 180 /* 181 * Get rid of trailing newline for dprintf logs. 182 */ 183 if (dprint && buf[0] != '\0') { 184 nl = &buf[strlen(buf) - 1]; 185 if (*nl == '\n') 186 *nl = '\0'; 187 } 188 189 /* 190 * To get this data enable the zfs__dprintf trace point as shown: 191 * 192 * # Enable zfs__dprintf tracepoint, clear the tracepoint ring buffer 193 * $ echo 1 > /sys/kernel/debug/tracing/events/zfs/enable 194 * $ echo 0 > /sys/kernel/debug/tracing/trace 195 * 196 * # Dump the ring buffer. 197 * $ cat /sys/kernel/debug/tracing/trace 198 */ 199 DTRACE_PROBE1(zfs__dprintf, char *, buf); 200 201 /* 202 * To get this data: 203 * 204 * $ cat /proc/spl/kstat/zfs/dbgmsg 205 * 206 * To clear the buffer: 207 * $ echo 0 > /proc/spl/kstat/zfs/dbgmsg 208 */ 209 __zfs_dbgmsg(buf); 210 211 kmem_free(buf, size); 212 } 213 214 module_param(zfs_dbgmsg_enable, int, 0644); 215 MODULE_PARM_DESC(zfs_dbgmsg_enable, "Enable ZFS debug message log"); 216 217 module_param(zfs_dbgmsg_maxsize, uint, 0644); 218 MODULE_PARM_DESC(zfs_dbgmsg_maxsize, "Maximum ZFS debug log size"); 219