mirror_zfs/module/zfs/zfs_debug_common.c
Tony Hutter 8d1489735b
nvlist: Add nvlist_snprintf() and zfs_dbgmsg_nvlist()
Add nvlist_snprintf() to print a nvlist to a buffer.  This is basically
the snprintf() version of dump_nvlist().  Along with that, add a
zfs_dbgmsg_nvlist() to print out an nvlist to dbgmsg.  This will aid in
debugging.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #17215
2025-04-18 09:22:16 -04:00

98 lines
2.4 KiB
C

// SPDX-License-Identifier: CDDL-1.0
/*
* 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 https://opensource.org/licenses/CDDL-1.0.
* 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) 2025 by Lawrence Livermore National Security, LLC.
*/
/*
* This file contains zfs_dbgmsg() specific functions that are not OS or
* userspace specific.
*/
#if !defined(_KERNEL)
#include <string.h>
#endif
#include <sys/zfs_context.h>
#include <sys/zfs_debug.h>
#include <sys/nvpair.h>
/*
* Given a multi-line string, print out one of the lines and return a pointer
* to the next line. Lines are demarcated by '\n'. Note: this modifies the
* input string (buf[]).
*
* This function is meant to be used in a loop like:
* while (buf != NULL)
* buf = kernel_print_one_line(buf);
*
* This function is useful for printing large, multi-line text buffers.
*
* Returns the pointer to the beginning of the next line in buf[], or NULL
* if it's the last line, or nothing more to print.
*/
static char *
zfs_dbgmsg_one_line(char *buf)
{
char *nl;
if (!buf)
return (NULL);
nl = strchr(buf, '\n');
if (nl == NULL) {
__zfs_dbgmsg(buf);
return (NULL); /* done */
}
*nl = '\0';
__zfs_dbgmsg(buf);
return (nl + 1);
}
/*
* Dump an nvlist tree to dbgmsg.
*
* This is the zfs_dbgmsg version of userspace's dump_nvlist() from libnvpair.
*/
void
__zfs_dbgmsg_nvlist(nvlist_t *nv)
{
int len;
char *buf;
len = nvlist_snprintf(NULL, 0, nv, 4);
len++; /* Add null terminator */
buf = vmem_alloc(len, KM_SLEEP);
if (buf == NULL)
return;
(void) nvlist_snprintf(buf, len, nv, 4);
while (buf != NULL)
buf = zfs_dbgmsg_one_line(buf);
vmem_free(buf, len);
}
#ifdef _KERNEL
EXPORT_SYMBOL(__zfs_dbgmsg_nvlist);
#endif