lib/libzpool/zfs_debug.c

   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 https://opensource.org/licenses/CDDL-1.0.
  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  * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
  24  * Copyright (c) 2024, Rob Norris <robn@despairlabs.com>
  25  */
  26
  27 #include <sys/zfs_context.h>
  28
  29 typedef struct zfs_dbgmsg {
  30         list_node_t             zdm_node;
  31         uint64_t                zdm_timestamp;
  32         uint_t                  zdm_size;
  33         char                    zdm_msg[]; /* variable length allocation */
  34 } zfs_dbgmsg_t;
  35
  36 static list_t zfs_dbgmsgs;
  37 static kmutex_t zfs_dbgmsgs_lock;
  38
  39 int zfs_dbgmsg_enable = B_TRUE;
  40
  41 void
  42 zfs_dbgmsg_init(void)
  43 {
  44         list_create(&zfs_dbgmsgs, sizeof (zfs_dbgmsg_t),
  45             offsetof(zfs_dbgmsg_t, zdm_node));
  46         mutex_init(&zfs_dbgmsgs_lock, NULL, MUTEX_DEFAULT, NULL);
  47 }
  48
  49 void
  50 zfs_dbgmsg_fini(void)
  51 {
  52         zfs_dbgmsg_t *zdm;
  53         while ((zdm = list_remove_head(&zfs_dbgmsgs)))
  54                 umem_free(zdm, zdm->zdm_size);
  55         mutex_destroy(&zfs_dbgmsgs_lock);
  56 }
  57
  58 void
  59 __set_error(const char *file, const char *func, int line, int err)
  60 {
  61         if (zfs_flags & ZFS_DEBUG_SET_ERROR)
  62                 __dprintf(B_FALSE, file, func, line, "error %lu",
  63                     (ulong_t)err);
  64 }
  65
  66 void
  67 __zfs_dbgmsg(char *buf)
  68 {
  69         uint_t size = sizeof (zfs_dbgmsg_t) + strlen(buf) + 1;
  70         zfs_dbgmsg_t *zdm = umem_zalloc(size, KM_SLEEP);
  71         zdm->zdm_size = size;
  72         zdm->zdm_timestamp = gethrestime_sec();
  73         strcpy(zdm->zdm_msg, buf);
  74
  75         mutex_enter(&zfs_dbgmsgs_lock);
  76         list_insert_tail(&zfs_dbgmsgs, zdm);
  77         mutex_exit(&zfs_dbgmsgs_lock);
  78 }
  79
  80 void
  81 zfs_dbgmsg_print(int fd, const char *tag)
  82 {
  83         ssize_t ret __attribute__((unused));
  84
  85         mutex_enter(&zfs_dbgmsgs_lock);
  86
  87         /*
  88          * We use write() in this function instead of printf()
  89          * so it is safe to call from a signal handler.
  90          */
  91         ret = write(fd, "ZFS_DBGMSG(", 11);
  92         ret = write(fd, tag, strlen(tag));
  93         ret = write(fd, ") START:\n", 9);
  94
  95         for (zfs_dbgmsg_t *zdm = list_head(&zfs_dbgmsgs); zdm != NULL;
  96             zdm = list_next(&zfs_dbgmsgs, zdm)) {
  97                 ret = write(fd, zdm->zdm_msg, strlen(zdm->zdm_msg));
  98                 ret = write(fd, "\n", 1);
  99         }
 100
 101         ret = write(fd, "ZFS_DBGMSG(", 11);
 102         ret = write(fd, tag, strlen(tag));
 103         ret = write(fd, ") END\n", 6);
 104
 105         mutex_exit(&zfs_dbgmsgs_lock);
 106 }