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 https://opensource.org/licenses/CDDL-1.0. 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 * Copyright (c) 2024, Rob Norris <robn@despairlabs.com> 25 */ 26 27 #include <sys/zfs_context.h> 28 29 typedef struct zfs_dbgmsg { 30 list_node_t zdm_node; 31 uint64_t zdm_timestamp; 32 uint_t zdm_size; 33 char zdm_msg[]; /* variable length allocation */ 34 } zfs_dbgmsg_t; 35 36 static list_t zfs_dbgmsgs; 37 static kmutex_t zfs_dbgmsgs_lock; 38 static uint_t zfs_dbgmsg_size = 0; 39 static uint_t zfs_dbgmsg_maxsize = 4<<20; /* 4MB */ 40 41 int zfs_dbgmsg_enable = B_TRUE; 42 43 static void 44 zfs_dbgmsg_purge(uint_t max_size) 45 { 46 while (zfs_dbgmsg_size > max_size) { 47 zfs_dbgmsg_t *zdm = list_remove_head(&zfs_dbgmsgs); 48 if (zdm == NULL) 49 return; 50 51 uint_t size = zdm->zdm_size; 52 kmem_free(zdm, size); 53 zfs_dbgmsg_size -= size; 54 } 55 } 56 57 void 58 zfs_dbgmsg_init(void) 59 { 60 list_create(&zfs_dbgmsgs, sizeof (zfs_dbgmsg_t), 61 offsetof(zfs_dbgmsg_t, zdm_node)); 62 mutex_init(&zfs_dbgmsgs_lock, NULL, MUTEX_DEFAULT, NULL); 63 } 64 65 void 66 zfs_dbgmsg_fini(void) 67 { 68 zfs_dbgmsg_t *zdm; 69 while ((zdm = list_remove_head(&zfs_dbgmsgs))) 70 umem_free(zdm, zdm->zdm_size); 71 mutex_destroy(&zfs_dbgmsgs_lock); 72 } 73 74 void 75 __set_error(const char *file, const char *func, int line, int err) 76 { 77 if (zfs_flags & ZFS_DEBUG_SET_ERROR) 78 __dprintf(B_FALSE, file, func, line, "error %lu", 79 (ulong_t)err); 80 } 81 82 void 83 __zfs_dbgmsg(char *buf) 84 { 85 uint_t size = sizeof (zfs_dbgmsg_t) + strlen(buf) + 1; 86 zfs_dbgmsg_t *zdm = umem_zalloc(size, KM_SLEEP); 87 zdm->zdm_size = size; 88 zdm->zdm_timestamp = gethrestime_sec(); 89 strcpy(zdm->zdm_msg, buf); 90 91 mutex_enter(&zfs_dbgmsgs_lock); 92 list_insert_tail(&zfs_dbgmsgs, zdm); 93 zfs_dbgmsg_size += size; 94 zfs_dbgmsg_purge(zfs_dbgmsg_maxsize); 95 mutex_exit(&zfs_dbgmsgs_lock); 96 } 97 98 void 99 zfs_dbgmsg_print(int fd, const char *tag) 100 { 101 ssize_t ret __attribute__((unused)); 102 103 mutex_enter(&zfs_dbgmsgs_lock); 104 105 /* 106 * We use write() in this function instead of printf() 107 * so it is safe to call from a signal handler. 108 */ 109 ret = write(fd, "ZFS_DBGMSG(", 11); 110 ret = write(fd, tag, strlen(tag)); 111 ret = write(fd, ") START:\n", 9); 112 113 for (zfs_dbgmsg_t *zdm = list_head(&zfs_dbgmsgs); zdm != NULL; 114 zdm = list_next(&zfs_dbgmsgs, zdm)) { 115 ret = write(fd, zdm->zdm_msg, strlen(zdm->zdm_msg)); 116 ret = write(fd, "\n", 1); 117 } 118 119 ret = write(fd, "ZFS_DBGMSG(", 11); 120 ret = write(fd, tag, strlen(tag)); 121 ret = write(fd, ") END\n", 6); 122 123 mutex_exit(&zfs_dbgmsgs_lock); 124 } 125