zfs_debug.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10

    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  */
   25 
   26 #include <sys/zfs_context.h>
   27 #include <sys/trace_zfs.h>
   28 
   29 typedef struct zfs_dbgmsg {
   30         procfs_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 procfs_list_t zfs_dbgmsgs;
   37 static uint_t zfs_dbgmsg_size = 0;
   38 static uint_t zfs_dbgmsg_maxsize = 4<<20; /* 4MB */
   39 
   40 /*
   41  * Internal ZFS debug messages are enabled by default.
   42  *
   43  * # Print debug messages
   44  * cat /proc/spl/kstat/zfs/dbgmsg
   45  *
   46  * # Disable the kernel debug message log.
   47  * echo 0 > /sys/module/zfs/parameters/zfs_dbgmsg_enable
   48  *
   49  * # Clear the kernel debug message log.
   50  * echo 0 >/proc/spl/kstat/zfs/dbgmsg
   51  */
   52 int zfs_dbgmsg_enable = B_TRUE;
   53 
   54 static int
   55 zfs_dbgmsg_show_header(struct seq_file *f)
   56 {
   57         seq_printf(f, "%-12s %-8s\n", "timestamp", "message");
   58         return (0);
   59 }
   60 
   61 static int
   62 zfs_dbgmsg_show(struct seq_file *f, void *p)
   63 {
   64         zfs_dbgmsg_t *zdm = (zfs_dbgmsg_t *)p;
   65         seq_printf(f, "%-12llu %-s\n",
   66             (u_longlong_t)zdm->zdm_timestamp, zdm->zdm_msg);
   67         return (0);
   68 }
   69 
   70 static void
   71 zfs_dbgmsg_purge(uint_t max_size)
   72 {
   73         while (zfs_dbgmsg_size > max_size) {
   74                 zfs_dbgmsg_t *zdm = list_remove_head(&zfs_dbgmsgs.pl_list);
   75                 if (zdm == NULL)
   76                         return;
   77 
   78                 uint_t size = zdm->zdm_size;
   79                 kmem_free(zdm, size);
   80                 zfs_dbgmsg_size -= size;
   81         }
   82 }
   83 
   84 static int
   85 zfs_dbgmsg_clear(procfs_list_t *procfs_list)
   86 {
   87         (void) procfs_list;
   88         mutex_enter(&zfs_dbgmsgs.pl_lock);
   89         zfs_dbgmsg_purge(0);
   90         mutex_exit(&zfs_dbgmsgs.pl_lock);
   91         return (0);
   92 }
   93 
   94 void
   95 zfs_dbgmsg_init(void)
   96 {
   97         procfs_list_install("zfs",
   98             NULL,
   99             "dbgmsg",
  100             0600,
  101             &zfs_dbgmsgs,
  102             zfs_dbgmsg_show,
  103             zfs_dbgmsg_show_header,
  104             zfs_dbgmsg_clear,
  105             offsetof(zfs_dbgmsg_t, zdm_node));
  106 }
  107 
  108 void
  109 zfs_dbgmsg_fini(void)
  110 {
  111         procfs_list_uninstall(&zfs_dbgmsgs);
  112         zfs_dbgmsg_purge(0);
  113 
  114         /*
  115          * TODO - decide how to make this permanent
  116          */
  117 #ifdef _KERNEL
  118         procfs_list_destroy(&zfs_dbgmsgs);
  119 #endif
  120 }
  121 
  122 void
  123 __set_error(const char *file, const char *func, int line, int err)
  124 {
  125         /*
  126          * To enable this:
  127          *
  128          * $ echo 512 >/sys/module/zfs/parameters/zfs_flags
  129          */
  130         if (zfs_flags & ZFS_DEBUG_SET_ERROR)
  131                 __dprintf(B_FALSE, file, func, line, "error %lu",
  132                     (ulong_t)err);
  133 }
  134 
  135 void
  136 __zfs_dbgmsg(char *buf)
  137 {
  138         uint_t size = sizeof (zfs_dbgmsg_t) + strlen(buf) + 1;
  139         zfs_dbgmsg_t *zdm = kmem_zalloc(size, KM_SLEEP);
  140         zdm->zdm_size = size;
  141         zdm->zdm_timestamp = gethrestime_sec();
  142         strcpy(zdm->zdm_msg, buf);
  143 
  144         mutex_enter(&zfs_dbgmsgs.pl_lock);
  145         procfs_list_add(&zfs_dbgmsgs, zdm);
  146         zfs_dbgmsg_size += size;
  147         zfs_dbgmsg_purge(zfs_dbgmsg_maxsize);
  148         mutex_exit(&zfs_dbgmsgs.pl_lock);
  149 }
  150 
  151 #ifdef _KERNEL
  152 
  153 void
  154 __dprintf(boolean_t dprint, const char *file, const char *func,
  155     int line, const char *fmt, ...)
  156 {
  157         const char *newfile;
  158         va_list adx;
  159         size_t size;
  160         char *buf;
  161         char *nl;
  162         int i;
  163         char *prefix = (dprint) ? "dprintf: " : "";
  164 
  165         size = 1024;
  166         buf = kmem_alloc(size, KM_SLEEP);
  167 
  168         /*
  169          * Get rid of annoying prefix to filename.
  170          */
  171         newfile = strrchr(file, '/');
  172         if (newfile != NULL) {
  173                 newfile = newfile + 1; /* Get rid of leading / */
  174         } else {
  175                 newfile = file;
  176         }
  177 
  178         i = snprintf(buf, size, "%s%s:%d:%s(): ", prefix, newfile, line, func);
  179 
  180         if (i < size) {
  181                 va_start(adx, fmt);
  182                 (void) vsnprintf(buf + i, size - i, fmt, adx);
  183                 va_end(adx);
  184         }
  185 
  186         /*
  187          * Get rid of trailing newline for dprintf logs.
  188          */
  189         if (dprint && buf[0] != '\0') {
  190                 nl = &buf[strlen(buf) - 1];
  191                 if (*nl == '\n')
  192                         *nl = '\0';
  193         }
  194 
  195         /*
  196          * To get this data enable the zfs__dprintf trace point as shown:
  197          *
  198          * # Enable zfs__dprintf tracepoint, clear the tracepoint ring buffer
  199          * $ echo 1 > /sys/kernel/debug/tracing/events/zfs/enable
  200          * $ echo 0 > /sys/kernel/debug/tracing/trace
  201          *
  202          * # Dump the ring buffer.
  203          * $ cat /sys/kernel/debug/tracing/trace
  204          */
  205         DTRACE_PROBE1(zfs__dprintf, char *, buf);
  206 
  207         /*
  208          * To get this data:
  209          *
  210          * $ cat /proc/spl/kstat/zfs/dbgmsg
  211          *
  212          * To clear the buffer:
  213          * $ echo 0 > /proc/spl/kstat/zfs/dbgmsg
  214          */
  215         __zfs_dbgmsg(buf);
  216 
  217         kmem_free(buf, size);
  218 }
  219 
  220 #else
  221 
  222 void
  223 zfs_dbgmsg_print(const char *tag)
  224 {
  225         ssize_t ret __attribute__((unused));
  226 
  227         /*
  228          * We use write() in this function instead of printf()
  229          * so it is safe to call from a signal handler.
  230          */
  231         ret = write(STDOUT_FILENO, "ZFS_DBGMSG(", 11);
  232         ret = write(STDOUT_FILENO, tag, strlen(tag));
  233         ret = write(STDOUT_FILENO, ") START:\n", 9);
  234 
  235         mutex_enter(&zfs_dbgmsgs.pl_lock);
  236         for (zfs_dbgmsg_t *zdm = list_head(&zfs_dbgmsgs.pl_list); zdm != NULL;
  237             zdm = list_next(&zfs_dbgmsgs.pl_list, zdm)) {
  238                 ret = write(STDOUT_FILENO, zdm->zdm_msg,
  239                     strlen(zdm->zdm_msg));
  240                 ret = write(STDOUT_FILENO, "\n", 1);
  241         }
  242 
  243         ret = write(STDOUT_FILENO, "ZFS_DBGMSG(", 11);
  244         ret = write(STDOUT_FILENO, tag, strlen(tag));
  245         ret = write(STDOUT_FILENO, ") END\n", 6);
  246 
  247         mutex_exit(&zfs_dbgmsgs.pl_lock);
  248 }
  249 #endif /* _KERNEL */
  250 
  251 #ifdef _KERNEL
  252 module_param(zfs_dbgmsg_enable, int, 0644);
  253 MODULE_PARM_DESC(zfs_dbgmsg_enable, "Enable ZFS debug message log");
  254 
  255 /* BEGIN CSTYLED */
  256 module_param(zfs_dbgmsg_maxsize, uint, 0644);
  257 /* END CSTYLED */
  258 MODULE_PARM_DESC(zfs_dbgmsg_maxsize, "Maximum ZFS debug log size");
  259 #endif

Cache object: b2d58d989e0bd4c9bcb0aac8de4fa436

[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.

FreeBSD/Linux Kernel Cross Reference sys/contrib/openzfs/module/os/linux/zfs/zfs_debug.c

FreeBSD/Linux Kernel Cross Reference
sys/contrib/openzfs/module/os/linux/zfs/zfs_debug.c