/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2012, 2014 by Delphix. All rights reserved. */ #include <sys/zfs_context.h> list_t zfs_dbgmsgs; int zfs_dbgmsg_size; kmutex_t zfs_dbgmsgs_lock; int zfs_dbgmsg_maxsize = 4<<20; /* 4MB */ void zfs_dbgmsg_init(void) { list_create(&zfs_dbgmsgs, sizeof (zfs_dbgmsg_t), offsetof(zfs_dbgmsg_t, zdm_node)); mutex_init(&zfs_dbgmsgs_lock, NULL, MUTEX_DEFAULT, NULL); } void zfs_dbgmsg_fini(void) { zfs_dbgmsg_t *zdm; while ((zdm = list_remove_head(&zfs_dbgmsgs)) != NULL) { int size = sizeof (zfs_dbgmsg_t) + strlen(zdm->zdm_msg); kmem_free(zdm, size); zfs_dbgmsg_size -= size; } mutex_destroy(&zfs_dbgmsgs_lock); ASSERT0(zfs_dbgmsg_size); } /* * To get this data enable the zfs__dbgmsg tracepoint as shown: * * # Enable zfs__dbgmsg tracepoint, clear the tracepoint ring buffer * $ echo 1 > /sys/kernel/debug/tracing/events/zfs/enable * $ echo 0 > /sys/kernel/debug/tracing/trace * * # Dump the ring buffer. * $ cat /sys/kernel/debug/tracing/trace */ void zfs_dbgmsg(const char *fmt, ...) { int size; va_list adx; char *nl; zfs_dbgmsg_t *zdm; va_start(adx, fmt); size = vsnprintf(NULL, 0, fmt, adx); va_end(adx); /* * There is one byte of string in sizeof (zfs_dbgmsg_t), used * for the terminating null. */ zdm = kmem_alloc(sizeof (zfs_dbgmsg_t) + size, KM_SLEEP); zdm->zdm_timestamp = gethrestime_sec(); va_start(adx, fmt); (void) vsnprintf(zdm->zdm_msg, size + 1, fmt, adx); va_end(adx); /* * Get rid of trailing newline. */ nl = strrchr(zdm->zdm_msg, '\n'); if (nl != NULL) *nl = '\0'; DTRACE_PROBE1(zfs__dbgmsg, char *, zdm->zdm_msg); mutex_enter(&zfs_dbgmsgs_lock); list_insert_tail(&zfs_dbgmsgs, zdm); zfs_dbgmsg_size += sizeof (zfs_dbgmsg_t) + size; while (zfs_dbgmsg_size > zfs_dbgmsg_maxsize) { zdm = list_remove_head(&zfs_dbgmsgs); size = sizeof (zfs_dbgmsg_t) + strlen(zdm->zdm_msg); kmem_free(zdm, size); zfs_dbgmsg_size -= size; } mutex_exit(&zfs_dbgmsgs_lock); } void zfs_dbgmsg_print(const char *tag) { #if !defined(_KERNEL) zfs_dbgmsg_t *zdm; (void) printf("ZFS_DBGMSG(%s):\n", tag); mutex_enter(&zfs_dbgmsgs_lock); for (zdm = list_head(&zfs_dbgmsgs); zdm; zdm = list_next(&zfs_dbgmsgs, zdm)) (void) printf("%s\n", zdm->zdm_msg); mutex_exit(&zfs_dbgmsgs_lock); #endif /* !_KERNEL */ }