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", 131 (ulong_t)err); 132 } 133 134 void 135 __zfs_dbgmsg(char *buf) 136 { 137 int size = sizeof (zfs_dbgmsg_t) + strlen(buf); 138 zfs_dbgmsg_t *zdm = kmem_zalloc(size, KM_SLEEP); 139 zdm->zdm_size = size; 140 zdm->zdm_timestamp = gethrestime_sec(); 141 strcpy(zdm->zdm_msg, buf); 142 143 mutex_enter(&zfs_dbgmsgs.pl_lock); 144 procfs_list_add(&zfs_dbgmsgs, zdm); 145 zfs_dbgmsg_size += size; 146 zfs_dbgmsg_purge(MAX(zfs_dbgmsg_maxsize, 0)); 147 mutex_exit(&zfs_dbgmsgs.pl_lock); 148 } 149 150 #ifdef _KERNEL 151 152 void 153 __dprintf(boolean_t dprint, const char *file, const char *func, 154 int line, const char *fmt, ...) 155 { 156 const char *newfile; 157 va_list adx; 158 size_t size; 159 char *buf; 160 char *nl; 161 int i; 162 char *prefix = (dprint) ? "dprintf: " : ""; 163 164 size = 1024; 165 buf = kmem_alloc(size, KM_SLEEP); 166 167 /* 168 * Get rid of annoying prefix to filename. 169 */ 170 newfile = strrchr(file, '/'); 171 if (newfile != NULL) { 172 newfile = newfile + 1; /* Get rid of leading / */ 173 } else { 174 newfile = file; 175 } 176 177 i = snprintf(buf, size, "%s%s:%d:%s(): ", prefix, newfile, line, func); 178 179 if (i < size) { 180 va_start(adx, fmt); 181 (void) vsnprintf(buf + i, size - i, fmt, adx); 182 va_end(adx); 183 } 184 185 /* 186 * Get rid of trailing newline for dprintf logs. 187 */ 188 if (dprint && buf[0] != '\0') { 189 nl = &buf[strlen(buf) - 1]; 190 if (*nl == '\n') 191 *nl = '\0'; 192 } 193 194 /* 195 * To get this data enable the zfs__dprintf trace point as shown: 196 * 197 * # Enable zfs__dprintf tracepoint, clear the tracepoint ring buffer 198 * $ echo 1 > /sys/kernel/debug/tracing/events/zfs/enable 199 * $ echo 0 > /sys/kernel/debug/tracing/trace 200 * 201 * # Dump the ring buffer. 202 * $ cat /sys/kernel/debug/tracing/trace 203 */ 204 DTRACE_PROBE1(zfs__dprintf, char *, buf); 205 206 /* 207 * To get this data: 208 * 209 * $ cat /proc/spl/kstat/zfs/dbgmsg 210 * 211 * To clear the buffer: 212 * $ echo 0 > /proc/spl/kstat/zfs/dbgmsg 213 */ 214 __zfs_dbgmsg(buf); 215 216 kmem_free(buf, size); 217 } 218 219 #else 220 221 void 222 zfs_dbgmsg_print(const char *tag) 223 { 224 ssize_t ret __attribute__((unused)); 225 226 /* 227 * We use write() in this function instead of printf() 228 * so it is safe to call from a signal handler. 229 */ 230 ret = write(STDOUT_FILENO, "ZFS_DBGMSG(", 11); 231 ret = write(STDOUT_FILENO, tag, strlen(tag)); 232 ret = write(STDOUT_FILENO, ") START:\n", 9); 233 234 mutex_enter(&zfs_dbgmsgs.pl_lock); 235 for (zfs_dbgmsg_t *zdm = list_head(&zfs_dbgmsgs.pl_list); zdm != NULL; 236 zdm = list_next(&zfs_dbgmsgs.pl_list, zdm)) { 237 ret = write(STDOUT_FILENO, zdm->zdm_msg, 238 strlen(zdm->zdm_msg)); 239 ret = write(STDOUT_FILENO, "\n", 1); 240 } 241 242 ret = write(STDOUT_FILENO, "ZFS_DBGMSG(", 11); 243 ret = write(STDOUT_FILENO, tag, strlen(tag)); 244 ret = write(STDOUT_FILENO, ") END\n", 6); 245 246 mutex_exit(&zfs_dbgmsgs.pl_lock); 247 } 248 #endif /* _KERNEL */ 249 250 #ifdef _KERNEL 251 module_param(zfs_dbgmsg_enable, int, 0644); 252 MODULE_PARM_DESC(zfs_dbgmsg_enable, "Enable ZFS debug message log"); 253 254 module_param(zfs_dbgmsg_maxsize, int, 0644); 255 MODULE_PARM_DESC(zfs_dbgmsg_maxsize, "Maximum ZFS debug log size"); 256 #endif 257