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/*
* 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_PUSHPAGE);
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 */
}
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