usr/src/cmd/stat/common/mnt.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 #include <stdlib.h>
  30 #include <sys/types.h>
  31 #include <stdio.h>
  32 #include <sys/mnttab.h>
  33 #include <sys/mntent.h>
  34 #include <sys/stat.h>
  35 #include <sys/time.h>
  36 #include <string.h>
  37 #include <fcntl.h>
  38
  39 #include "statcommon.h"
  40 #include "dsr.h"
  41
  42 static time_t mtime;
  43 mnt_t *nfs;
  44 static mnt_t *ufs;
  45
  46 static void build_mnt_list(FILE *);
  47
  48 mnt_t *
  49 lookup_mntent_byname(char *nm)
  50 {
  51         mnt_t *rv = 0;
  52         mnt_t *minfo;
  53         uint_t did_nfs;
  54
  55
  56         if (nm) {
  57                 minfo = ufs;
  58                 did_nfs = 0;
  59                 while (minfo) {
  60                         if (strcmp(nm, minfo->device_name)) {
  61                                 if (minfo->next != 0)
  62                                         minfo = minfo->next;
  63                                 else if (did_nfs == 0) {
  64                                         minfo = nfs;
  65                                         did_nfs = 1;
  66                                 }
  67                                 else
  68                                         minfo = 0;
  69                         } else {
  70                                 rv = minfo;
  71                                 break;
  72                         }
  73                 }
  74         }
  75         return (rv);
  76 }
  77
  78 void
  79 do_mnttab(void)
  80 {
  81         struct stat     buf;
  82         FILE            *mpt;
  83         struct flock    lb;
  84
  85         if (stat(MNTTAB, &buf) == 0) {
  86                 if (buf.st_mtime != mtime) {
  87                         /*
  88                          * File has changed. Get the new file.
  89                          */
  90                         if ((mpt = fopen(MNTTAB, "r"))) {
  91                                 lb.l_type = F_RDLCK;
  92                                 lb.l_whence = 0;
  93                                 lb.l_start = 0;
  94                                 lb.l_len = 0;
  95                                 (void) fcntl(fileno(mpt), F_SETLKW, &lb);
  96                                 build_mnt_list(mpt);
  97                                 mtime = buf.st_mtime;
  98                                 /*
  99                                  * Lock goes away when we close the file.
 100                                  */
 101                                 (void) fclose(mpt);
 102                         }
 103                 }
 104         }
 105 }
 106
 107 static void
 108 build_mnt_list(FILE *mpt)
 109 {
 110         mnt_t *item;
 111         mnt_t **which;
 112         mnt_t *tmp;
 113         int  found;
 114         struct extmnttab mnt;
 115
 116         if (mpt) {
 117                 while (nfs) {
 118                         free(nfs->device_name);
 119                         free(nfs->mount_point);
 120                         free(nfs->devinfo);
 121                         tmp = nfs;
 122                         nfs = nfs->next;
 123                         free(tmp);
 124                 }
 125                 while (ufs) {
 126                         free(ufs->device_name);
 127                         free(ufs->mount_point);
 128                         free(ufs->devinfo);
 129                         tmp = ufs;
 130                         ufs = ufs->next;
 131                         free(tmp);
 132                 }
 133                 (void) memset(&mnt, 0, sizeof (struct extmnttab));
 134
 135                 resetmnttab(mpt);
 136                 while ((found = getextmntent(mpt, &mnt,
 137                         sizeof (struct extmnttab))) != -1) {
 138                         if (found == 0) {
 139                                 if (strcmp(mnt.mnt_fstype, MNTTYPE_UFS) == 0)
 140                                         which = &ufs;
 141                                 else if (strcmp(mnt.mnt_fstype,
 142                                     MNTTYPE_NFS) == 0)
 143                                         which = &nfs;
 144                                 else
 145                                         which = 0;
 146                                 if (which) {
 147                                         item = safe_alloc(sizeof (mnt_t));
 148                                         item->device_name =
 149                                                 safe_strdup(mnt.mnt_special);
 150                                         item->mount_point =
 151                                                 safe_strdup(mnt.mnt_mountp);
 152                                         item->devinfo =
 153                                                 safe_strdup(mnt.mnt_mntopts);
 154                                         item->minor = mnt.mnt_minor;
 155                                         item->next = *which;
 156                                         *which = item;
 157                                 }
 158                         }
 159                 }
 160         }
 161 }