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 */ 24 25 #include <sys/zfs_context.h> 26 27 list_t zfs_dbgmsgs; 28 int zfs_dbgmsg_size; 29 kmutex_t zfs_dbgmsgs_lock; 30 int zfs_dbgmsg_maxsize = 1<<20; /* 1MB */ 31 32 void 33 zfs_dbgmsg_init(void) 34 { 35 list_create(&zfs_dbgmsgs, sizeof (zfs_dbgmsg_t), 36 offsetof(zfs_dbgmsg_t, zdm_node)); 37 mutex_init(&zfs_dbgmsgs_lock, NULL, MUTEX_DEFAULT, NULL); 38 } 39 40 void 41 zfs_dbgmsg_fini(void) 42 { 43 zfs_dbgmsg_t *zdm; 44 45 while ((zdm = list_remove_head(&zfs_dbgmsgs)) != NULL) { 46 int size = sizeof (zfs_dbgmsg_t) + strlen(zdm->zdm_msg); 47 kmem_free(zdm, size); 48 zfs_dbgmsg_size -= size; 49 } 50 mutex_destroy(&zfs_dbgmsgs_lock); 51 ASSERT3U(zfs_dbgmsg_size, ==, 0); 52 } 53 54 /* 55 * Print these messages by running: 56 * echo ::zfs_dbgmsg | mdb -k 57 * 58 * Monitor these messages by running: 59 * dtrace -q -n 'zfs-dbgmsg{printf("%s\n", stringof(arg0))}' 60 */ 61 void 62 zfs_dbgmsg(const char *fmt, ...) 63 { 64 int size; 65 va_list adx; 66 zfs_dbgmsg_t *zdm; 67 68 va_start(adx, fmt); 69 size = vsnprintf(NULL, 0, fmt, adx); 70 va_end(adx); 71 72 /* 73 * There is one byte of string in sizeof (zfs_dbgmsg_t), used 74 * for the terminating null. 75 */ 76 zdm = kmem_alloc(sizeof (zfs_dbgmsg_t) + size, KM_SLEEP); 77 zdm->zdm_timestamp = gethrestime_sec(); 78 79 va_start(adx, fmt); 80 (void) vsnprintf(zdm->zdm_msg, size + 1, fmt, adx); 81 va_end(adx); 82 83 DTRACE_PROBE1(zfs__dbgmsg, char *, zdm->zdm_msg); 84 85 mutex_enter(&zfs_dbgmsgs_lock); 86 list_insert_tail(&zfs_dbgmsgs, zdm); 87 zfs_dbgmsg_size += sizeof (zfs_dbgmsg_t) + size; 88 while (zfs_dbgmsg_size > zfs_dbgmsg_maxsize) { 89 zdm = list_remove_head(&zfs_dbgmsgs); 90 size = sizeof (zfs_dbgmsg_t) + strlen(zdm->zdm_msg); 91 kmem_free(zdm, size); 92 zfs_dbgmsg_size -= size; 93 } 94 mutex_exit(&zfs_dbgmsgs_lock); 95 } 96