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 28 list_t zfs_dbgmsgs; 29 int zfs_dbgmsg_size; 30 kmutex_t zfs_dbgmsgs_lock; 31 int zfs_dbgmsg_maxsize = 4<<20; /* 4MB */ 32 33 void 34 zfs_dbgmsg_init(void) 35 { 36 list_create(&zfs_dbgmsgs, sizeof (zfs_dbgmsg_t), 37 offsetof(zfs_dbgmsg_t, zdm_node)); 38 mutex_init(&zfs_dbgmsgs_lock, NULL, MUTEX_DEFAULT, NULL); 39 } 40 41 void 42 zfs_dbgmsg_fini(void) 43 { 44 zfs_dbgmsg_t *zdm; 45 46 while ((zdm = list_remove_head(&zfs_dbgmsgs)) != NULL) { 47 int size = sizeof (zfs_dbgmsg_t) + strlen(zdm->zdm_msg); 48 kmem_free(zdm, size); 49 zfs_dbgmsg_size -= size; 50 } 51 mutex_destroy(&zfs_dbgmsgs_lock); 52 ASSERT0(zfs_dbgmsg_size); 53 } 54 55 /* 56 * Print these messages by running: 57 * echo ::zfs_dbgmsg | mdb -k 58 * 59 * Monitor these messages by running: 60 * dtrace -qn 'zfs-dbgmsg{printf("%s\n", stringof(arg0))}' 61 * 62 * When used with libzpool, monitor with: 63 * dtrace -qn 'zfs$pid::zfs_dbgmsg:probe1{printf("%s\n", copyinstr(arg1))}' 64 */ 65 void 66 zfs_dbgmsg(const char *fmt, ...) 67 { 68 int size; 69 va_list adx; 70 zfs_dbgmsg_t *zdm; 71 72 va_start(adx, fmt); 73 size = vsnprintf(NULL, 0, fmt, adx); 74 va_end(adx); 75 76 /* 77 * There is one byte of string in sizeof (zfs_dbgmsg_t), used 78 * for the terminating null. 79 */ 80 zdm = kmem_alloc(sizeof (zfs_dbgmsg_t) + size, KM_SLEEP); 81 zdm->zdm_timestamp = gethrestime_sec(); 82 zdm->zdm_hrtime = gethrtime(); 83 84 va_start(adx, fmt); 85 (void) vsnprintf(zdm->zdm_msg, size + 1, fmt, adx); 86 va_end(adx); 87 88 DTRACE_PROBE1(zfs__dbgmsg, char *, zdm->zdm_msg); 89 90 mutex_enter(&zfs_dbgmsgs_lock); 91 list_insert_tail(&zfs_dbgmsgs, zdm); 92 zfs_dbgmsg_size += sizeof (zfs_dbgmsg_t) + size; 93 while (zfs_dbgmsg_size > zfs_dbgmsg_maxsize) { 94 zdm = list_remove_head(&zfs_dbgmsgs); 95 size = sizeof (zfs_dbgmsg_t) + strlen(zdm->zdm_msg); 96 kmem_free(zdm, size); 97 zfs_dbgmsg_size -= size; 98 } 99 mutex_exit(&zfs_dbgmsgs_lock); 100 } 101 102 void 103 zfs_dbgmsg_print(const char *tag) 104 { 105 zfs_dbgmsg_t *zdm; 106 107 (void) printf("ZFS_DBGMSG(%s):\n", tag); 108 mutex_enter(&zfs_dbgmsgs_lock); 109 for (zdm = list_head(&zfs_dbgmsgs); zdm; 110 zdm = list_next(&zfs_dbgmsgs, zdm)) 111 (void) printf("%s\n", zdm->zdm_msg); 112 mutex_exit(&zfs_dbgmsgs_lock); 113 } 114