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 http://www.opensolaris.org/os/licensing. 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 int zdm_size; 33 char zdm_msg[1]; /* variable length allocation */ 34 } zfs_dbgmsg_t; 35 36 procfs_list_t zfs_dbgmsgs; 37 int zfs_dbgmsg_size = 0; 38 int 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 = 1; 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(int 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 int 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 mutex_enter(&zfs_dbgmsgs.pl_lock); 88 zfs_dbgmsg_purge(0); 89 mutex_exit(&zfs_dbgmsgs.pl_lock); 90 return (0); 91 } 92 93 void 94 zfs_dbgmsg_init(void) 95 { 96 procfs_list_install("zfs", 97 NULL, 98 "dbgmsg", 99 0600, 100 &zfs_dbgmsgs, 101 zfs_dbgmsg_show, 102 zfs_dbgmsg_show_header, 103 zfs_dbgmsg_clear, 104 offsetof(zfs_dbgmsg_t, zdm_node)); 105 } 106 107 void 108 zfs_dbgmsg_fini(void) 109 { 110 procfs_list_uninstall(&zfs_dbgmsgs); 111 zfs_dbgmsg_purge(0); 112 113 /* 114 * TODO - decide how to make this permanent 115 */ 116 #ifdef _KERNEL 117 procfs_list_destroy(&zfs_dbgmsgs); 118 #endif 119 } 120 121 void 122 __set_error(const char *file, const char *func, int line, int err) 123 { 124 /* 125 * To enable this: 126 * 127 * $ echo 512 >/sys/module/zfs/parameters/zfs_flags 128 */ 129 if (zfs_flags & ZFS_DEBUG_SET_ERROR) 130 __dprintf(B_FALSE, file, func, line, "error %lu", err); 131 } 132 133 void 134 __zfs_dbgmsg(char *buf) 135 { 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); 141 142 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); 147 } 148 149 #ifdef _KERNEL 150 151 void 152 __dprintf(boolean_t dprint, const char *file, const char *func, 153 int line, const char *fmt, ...) 154 { 155 const char *newfile; 156 va_list adx; 157 size_t size; 158 char *buf; 159 char *nl; 160 int i; 161 char *prefix = (dprint) ? "dprintf: " : ""; 162 163 size = 1024; 164 buf = kmem_alloc(size, KM_SLEEP); 165 166 /* 167 * Get rid of annoying prefix to filename. 168 */ 169 newfile = strrchr(file, '/'); 170 if (newfile != NULL) { 171 newfile = newfile + 1; /* Get rid of leading / */ 172 } else { 173 newfile = file; 174 } 175 176 i = snprintf(buf, size, "%s%s:%d:%s(): ", prefix, newfile, line, func); 177 178 if (i < size) { 179 va_start(adx, fmt); 180 (void) vsnprintf(buf + i, size - i, fmt, adx); 181 va_end(adx); 182 } 183 184 /* 185 * Get rid of trailing newline for dprintf logs. 186 */ 187 if (dprint && buf[0] != '\0') { 188 nl = &buf[strlen(buf) - 1]; 189 if (*nl == '\n') 190 *nl = '\0'; 191 } 192 193 /* 194 * To get this data enable the zfs__dprintf trace point as shown: 195 * 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 199 * 200 * # Dump the ring buffer. 201 * $ cat /sys/kernel/debug/tracing/trace 202 */ 203 DTRACE_PROBE1(zfs__dprintf, char *, buf); 204 205 /* 206 * To get this data: 207 * 208 * $ cat /proc/spl/kstat/zfs/dbgmsg 209 * 210 * To clear the buffer: 211 * $ echo 0 > /proc/spl/kstat/zfs/dbgmsg 212 */ 213 __zfs_dbgmsg(buf); 214 215 kmem_free(buf, size); 216 } 217 218 #else 219 220 void 221 zfs_dbgmsg_print(const char *tag) 222 { 223 ssize_t ret __attribute__((unused)); 224 225 /* 226 * We use write() in this function instead of printf() 227 * so it is safe to call from a signal handler. 228 */ 229 ret = write(STDOUT_FILENO, "ZFS_DBGMSG(", 11); 230 ret = write(STDOUT_FILENO, tag, strlen(tag)); 231 ret = write(STDOUT_FILENO, ") START:\n", 9); 232 233 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); 239 } 240 241 ret = write(STDOUT_FILENO, "ZFS_DBGMSG(", 11); 242 ret = write(STDOUT_FILENO, tag, strlen(tag)); 243 ret = write(STDOUT_FILENO, ") END\n", 6); 244 245 mutex_exit(&zfs_dbgmsgs.pl_lock); 246 } 247 #endif /* _KERNEL */ 248 249 #ifdef _KERNEL 250 module_param(zfs_dbgmsg_enable, int, 0644); 251 MODULE_PARM_DESC(zfs_dbgmsg_enable, "Enable ZFS debug message log"); 252 253 module_param(zfs_dbgmsg_maxsize, int, 0644); 254 MODULE_PARM_DESC(zfs_dbgmsg_maxsize, "Maximum ZFS debug log size"); 255 #endif 256