zfs-builds-mm/zfs-2.0.0/module/os/freebsd/zfs/zfs_debug.c

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2020-12-02 17:25:31 +01:00
/*
* 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>
#include <sys/kstat.h>
typedef struct zfs_dbgmsg {
list_node_t zdm_node;
time_t zdm_timestamp;
int zdm_size;
char zdm_msg[1]; /* variable length allocation */
} zfs_dbgmsg_t;
list_t zfs_dbgmsgs;
int zfs_dbgmsg_size = 0;
kmutex_t zfs_dbgmsgs_lock;
int zfs_dbgmsg_maxsize = 4<<20; /* 4MB */
kstat_t *zfs_dbgmsg_kstat;
/*
* Internal ZFS debug messages are enabled by default.
*
* # Print debug messages
* dtrace -n 'zfs-dbgmsg { print(stringof(arg0)); }'
*
* # Disable the kernel debug message log.
* sysctl vfs.zfs.dbgmsg_enable=0
*/
int zfs_dbgmsg_enable = 1;
static int
zfs_dbgmsg_headers(char *buf, size_t size)
{
(void) snprintf(buf, size, "%-12s %-8s\n", "timestamp", "message");
return (0);
}
static int
zfs_dbgmsg_data(char *buf, size_t size, void *data)
{
zfs_dbgmsg_t *zdm = (zfs_dbgmsg_t *)data;
(void) snprintf(buf, size, "%-12llu %-s\n",
(u_longlong_t)zdm->zdm_timestamp, zdm->zdm_msg);
return (0);
}
static void *
zfs_dbgmsg_addr(kstat_t *ksp, loff_t n)
{
zfs_dbgmsg_t *zdm = (zfs_dbgmsg_t *)ksp->ks_private;
ASSERT(MUTEX_HELD(&zfs_dbgmsgs_lock));
if (n == 0)
ksp->ks_private = list_head(&zfs_dbgmsgs);
else if (zdm)
ksp->ks_private = list_next(&zfs_dbgmsgs, zdm);
return (ksp->ks_private);
}
static void
zfs_dbgmsg_purge(int max_size)
{
zfs_dbgmsg_t *zdm;
int size;
ASSERT(MUTEX_HELD(&zfs_dbgmsgs_lock));
while (zfs_dbgmsg_size > max_size) {
zdm = list_remove_head(&zfs_dbgmsgs);
if (zdm == NULL)
return;
size = zdm->zdm_size;
kmem_free(zdm, size);
zfs_dbgmsg_size -= size;
}
}
static int
zfs_dbgmsg_update(kstat_t *ksp, int rw)
{
if (rw == KSTAT_WRITE)
zfs_dbgmsg_purge(0);
return (0);
}
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);
zfs_dbgmsg_kstat = kstat_create("zfs", 0, "dbgmsg", "misc",
KSTAT_TYPE_RAW, 0, KSTAT_FLAG_VIRTUAL);
if (zfs_dbgmsg_kstat) {
zfs_dbgmsg_kstat->ks_lock = &zfs_dbgmsgs_lock;
zfs_dbgmsg_kstat->ks_ndata = UINT32_MAX;
zfs_dbgmsg_kstat->ks_private = NULL;
zfs_dbgmsg_kstat->ks_update = zfs_dbgmsg_update;
kstat_set_raw_ops(zfs_dbgmsg_kstat, zfs_dbgmsg_headers,
zfs_dbgmsg_data, zfs_dbgmsg_addr);
kstat_install(zfs_dbgmsg_kstat);
}
}
void
zfs_dbgmsg_fini(void)
{
if (zfs_dbgmsg_kstat)
kstat_delete(zfs_dbgmsg_kstat);
/*
* TODO - decide how to make this permanent
*/
#ifdef _KERNEL
mutex_enter(&zfs_dbgmsgs_lock);
zfs_dbgmsg_purge(0);
mutex_exit(&zfs_dbgmsgs_lock);
mutex_destroy(&zfs_dbgmsgs_lock);
#endif
}
void
__zfs_dbgmsg(char *buf)
{
zfs_dbgmsg_t *zdm;
int size;
DTRACE_PROBE1(zfs__dbgmsg, char *, buf);
size = sizeof (zfs_dbgmsg_t) + strlen(buf);
zdm = kmem_zalloc(size, KM_SLEEP);
zdm->zdm_size = size;
zdm->zdm_timestamp = gethrestime_sec();
strcpy(zdm->zdm_msg, buf);
mutex_enter(&zfs_dbgmsgs_lock);
list_insert_tail(&zfs_dbgmsgs, zdm);
zfs_dbgmsg_size += size;
zfs_dbgmsg_purge(MAX(zfs_dbgmsg_maxsize, 0));
mutex_exit(&zfs_dbgmsgs_lock);
}
void
__set_error(const char *file, const char *func, int line, int err)
{
/*
* To enable this:
*
* $ echo 512 >/sys/module/zfs/parameters/zfs_flags
*/
if (zfs_flags & ZFS_DEBUG_SET_ERROR)
__dprintf(B_FALSE, file, func, line, "error %lu", err);
}
#ifdef _KERNEL
void
__dprintf(boolean_t dprint, const char *file, const char *func,
int line, const char *fmt, ...)
{
const char *newfile;
va_list adx;
size_t size;
char *buf;
char *nl;
int i;
size = 1024;
buf = kmem_alloc(size, KM_SLEEP);
/*
* Get rid of annoying prefix to filename.
*/
newfile = strrchr(file, '/');
if (newfile != NULL) {
newfile = newfile + 1; /* Get rid of leading / */
} else {
newfile = file;
}
i = snprintf(buf, size, "%s:%d:%s(): ", newfile, line, func);
if (i < size) {
va_start(adx, fmt);
(void) vsnprintf(buf + i, size - i, fmt, adx);
va_end(adx);
}
/*
* Get rid of trailing newline.
*/
nl = strrchr(buf, '\n');
if (nl != NULL)
*nl = '\0';
__zfs_dbgmsg(buf);
kmem_free(buf, size);
}
#else
void
zfs_dbgmsg_print(const char *tag)
{
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 */
/* BEGIN CSTYLED */
ZFS_MODULE_PARAM(zfs, zfs_, dbgmsg_enable, INT, ZMOD_RW,
"Enable ZFS debug message log");
ZFS_MODULE_PARAM(zfs, zfs_, dbgmsg_maxsize, INT, ZMOD_RW,
"Maximum ZFS debug log size");
/* END CSTYLED */