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 by Delphix. All rights reserved. 24 */ 25 26 27 #include <sys/zfs_context.h> 28 29 list_t zfs_dbgmsgs; 30 int zfs_dbgmsg_size; 31 kmutex_t zfs_dbgmsgs_lock; 32 int zfs_dbgmsg_maxsize = 1<<20; /* 1MB */ 33 34 void 35 zfs_dbgmsg_init(void) 36 { 37 list_create(&zfs_dbgmsgs, sizeof (zfs_dbgmsg_t), 38 offsetof(zfs_dbgmsg_t, zdm_node)); 39 mutex_init(&zfs_dbgmsgs_lock, NULL, MUTEX_DEFAULT, NULL); 40 } 41 42 void 43 zfs_dbgmsg_fini(void) 44 { 45 zfs_dbgmsg_t *zdm; 46 47 while ((zdm = list_remove_head(&zfs_dbgmsgs)) != NULL) { 48 int size = sizeof (zfs_dbgmsg_t) + strlen(zdm->zdm_msg); 49 kmem_free(zdm, size); 50 zfs_dbgmsg_size -= size; 51 } 52 mutex_destroy(&zfs_dbgmsgs_lock); 53 ASSERT0(zfs_dbgmsg_size); 54 } 55 56 /* 57 * Print these messages by running: 58 * echo ::zfs_dbgmsg | mdb -k 59 * 60 * Monitor these messages by running: 61 * dtrace -q -n 'zfs-dbgmsg{printf("%s\n", stringof(arg0))}' 62 */ 63 void 64 zfs_dbgmsg(const char *fmt, ...) 65 { 66 int size; 67 va_list adx; 68 zfs_dbgmsg_t *zdm; 69 70 va_start(adx, fmt); 71 size = vsnprintf(NULL, 0, fmt, adx); 72 va_end(adx); 73 74 /* 75 * There is one byte of string in sizeof (zfs_dbgmsg_t), used 76 * for the terminating null. 77 */ 78 zdm = kmem_alloc(sizeof (zfs_dbgmsg_t) + size, KM_SLEEP); 79 zdm->zdm_timestamp = gethrestime_sec(); 80 81 va_start(adx, fmt); 82 (void) vsnprintf(zdm->zdm_msg, size + 1, fmt, adx); 83 va_end(adx); 84 85 DTRACE_PROBE1(zfs__dbgmsg, char *, zdm->zdm_msg); 86 87 mutex_enter(&zfs_dbgmsgs_lock); 88 list_insert_tail(&zfs_dbgmsgs, zdm); 89 zfs_dbgmsg_size += sizeof (zfs_dbgmsg_t) + size; 90 while (zfs_dbgmsg_size > zfs_dbgmsg_maxsize) { 91 zdm = list_remove_head(&zfs_dbgmsgs); 92 size = sizeof (zfs_dbgmsg_t) + strlen(zdm->zdm_msg); 93 kmem_free(zdm, size); 94 zfs_dbgmsg_size -= size; 95 } 96 mutex_exit(&zfs_dbgmsgs_lock); 97 } 98