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 static procfs_list_t zfs_dbgmsgs; 37 static 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 = 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(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 (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 /* 115 * TODO - decide how to make this permanent 116 */ 117 #ifdef _KERNEL 118 procfs_list_destroy(&zfs_dbgmsgs); 119 #endif 120 } 121 122 void 123 __set_error(const char *file, const char *func, int line, int err) 124 { 125 /* 126 * To enable this: 127 * 128 * $ echo 512 >/sys/module/zfs/parameters/zfs_flags 129 */ 130 if (zfs_flags & ZFS_DEBUG_SET_ERROR) 131 __dprintf(B_FALSE, file, func, line, "error %lu", 132 (ulong_t)err); 133 } 134 135 void 136 __zfs_dbgmsg(char *buf) 137 { 138 int size = sizeof (zfs_dbgmsg_t) + strlen(buf); 139 zfs_dbgmsg_t *zdm = kmem_zalloc(size, KM_SLEEP); 140 zdm->zdm_size = size; 141 zdm->zdm_timestamp = gethrestime_sec(); 142 strcpy(zdm->zdm_msg, buf); 143 144 mutex_enter(&zfs_dbgmsgs.pl_lock); 145 procfs_list_add(&zfs_dbgmsgs, zdm); 146 zfs_dbgmsg_size += size; 147 zfs_dbgmsg_purge(MAX(zfs_dbgmsg_maxsize, 0)); 148 mutex_exit(&zfs_dbgmsgs.pl_lock); 149 } 150 151 #ifdef _KERNEL 152 153 void 154 __dprintf(boolean_t dprint, const char *file, const char *func, 155 int line, const char *fmt, ...) 156 { 157 const char *newfile; 158 va_list adx; 159 size_t size; 160 char *buf; 161 char *nl; 162 int i; 163 char *prefix = (dprint) ? "dprintf: " : ""; 164 165 size = 1024; 166 buf = kmem_alloc(size, KM_SLEEP); 167 168 /* 169 * Get rid of annoying prefix to filename. 170 */ 171 newfile = strrchr(file, '/'); 172 if (newfile != NULL) { 173 newfile = newfile + 1; /* Get rid of leading / */ 174 } else { 175 newfile = file; 176 } 177 178 i = snprintf(buf, size, "%s%s:%d:%s(): ", prefix, newfile, line, func); 179 180 if (i < size) { 181 va_start(adx, fmt); 182 (void) vsnprintf(buf + i, size - i, fmt, adx); 183 va_end(adx); 184 } 185 186 /* 187 * Get rid of trailing newline for dprintf logs. 188 */ 189 if (dprint && buf[0] != '\0') { 190 nl = &buf[strlen(buf) - 1]; 191 if (*nl == '\n') 192 *nl = '\0'; 193 } 194 195 /* 196 * To get this data enable the zfs__dprintf trace point as shown: 197 * 198 * # Enable zfs__dprintf tracepoint, clear the tracepoint ring buffer 199 * $ echo 1 > /sys/kernel/debug/tracing/events/zfs/enable 200 * $ echo 0 > /sys/kernel/debug/tracing/trace 201 * 202 * # Dump the ring buffer. 203 * $ cat /sys/kernel/debug/tracing/trace 204 */ 205 DTRACE_PROBE1(zfs__dprintf, char *, buf); 206 207 /* 208 * To get this data: 209 * 210 * $ cat /proc/spl/kstat/zfs/dbgmsg 211 * 212 * To clear the buffer: 213 * $ echo 0 > /proc/spl/kstat/zfs/dbgmsg 214 */ 215 __zfs_dbgmsg(buf); 216 217 kmem_free(buf, size); 218 } 219 220 #else 221 222 void 223 zfs_dbgmsg_print(const char *tag) 224 { 225 ssize_t ret __attribute__((unused)); 226 227 /* 228 * We use write() in this function instead of printf() 229 * so it is safe to call from a signal handler. 230 */ 231 ret = write(STDOUT_FILENO, "ZFS_DBGMSG(", 11); 232 ret = write(STDOUT_FILENO, tag, strlen(tag)); 233 ret = write(STDOUT_FILENO, ") START:\n", 9); 234 235 mutex_enter(&zfs_dbgmsgs.pl_lock); 236 for (zfs_dbgmsg_t *zdm = list_head(&zfs_dbgmsgs.pl_list); zdm != NULL; 237 zdm = list_next(&zfs_dbgmsgs.pl_list, zdm)) { 238 ret = write(STDOUT_FILENO, zdm->zdm_msg, 239 strlen(zdm->zdm_msg)); 240 ret = write(STDOUT_FILENO, "\n", 1); 241 } 242 243 ret = write(STDOUT_FILENO, "ZFS_DBGMSG(", 11); 244 ret = write(STDOUT_FILENO, tag, strlen(tag)); 245 ret = write(STDOUT_FILENO, ") END\n", 6); 246 247 mutex_exit(&zfs_dbgmsgs.pl_lock); 248 } 249 #endif /* _KERNEL */ 250 251 #ifdef _KERNEL 252 module_param(zfs_dbgmsg_enable, int, 0644); 253 MODULE_PARM_DESC(zfs_dbgmsg_enable, "Enable ZFS debug message log"); 254 255 module_param(zfs_dbgmsg_maxsize, int, 0644); 256 MODULE_PARM_DESC(zfs_dbgmsg_maxsize, "Maximum ZFS debug log size"); 257 #endif 258