usr/src/lib/libdiskmgt/common/inuse_dump.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, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 /*
  30  * Checks for a match with the the dump slice.
  31  */
  32
  33 #include <stdlib.h>
  34 #include <stdio.h>
  35 #include <unistd.h>
  36 #include <string.h>
  37 #include <synch.h>
  38 #include <sys/param.h>
  39 #include <sys/types.h>
  40 #include <sys/stat.h>
  41 #include <fcntl.h>
  42 #include <sys/dumpadm.h>
  43
  44 #include "libdiskmgt.h"
  45 #include "disks_private.h"
  46
  47 /* Cached file descriptor for /dev/dump. */
  48 static int              dump_fd = -1;
  49
  50 static mutex_t          dump_lock = DEFAULTMUTEX;
  51
  52 /*
  53  * Check the dump device against the input slice.
  54  */
  55 int
  56 inuse_dump(char *slice, nvlist_t *attrs, int *errp)
  57 {
  58         int             found = 0;
  59         int             fd;
  60         char            device[MAXPATHLEN];
  61
  62         *errp = 0;
  63         if (slice == NULL) {
  64             return (found);
  65         }
  66
  67         /*
  68          * We only want to open /dev/dump once instead of for every
  69          * slice so we cache the open file descriptor.  The ioctl
  70          * is cheap so we can do that for every slice.
  71          */
  72         (void) mutex_lock(&dump_lock);
  73
  74         if (dump_fd == -1) {
  75                 if ((dump_fd = open("/dev/dump", O_RDONLY)) >= 0)
  76                         (void) fcntl(dump_fd, F_SETFD, FD_CLOEXEC);
  77         }
  78
  79         fd = dump_fd;
  80
  81         (void) mutex_unlock(&dump_lock);
  82
  83         if (fd != -1) {
  84                 if (ioctl(fd, DIOCGETDEV, device) != -1) {
  85                         if (strcmp(slice, device) == 0) {
  86                                 libdiskmgt_add_str(attrs, DM_USED_BY,
  87                                     DM_USE_DUMP, errp);
  88                                 libdiskmgt_add_str(attrs, DM_USED_NAME,
  89                                     DM_USE_DUMP, errp);
  90                                 found = 1;
  91                         }
  92                 }
  93         }
  94
  95         return (found);
  96 }