xref: /illumos-gate/usr/src/cmd/stat/common/mnt.c (revision 7c478bd9)
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 *
lookup_mntent_byname(char * nm)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
do_mnttab(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
build_mnt_list(FILE * mpt)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 }
162