projects / mirror_zfs.git / blame
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|---|---|---|
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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 | } |