xref: /titanic_41/usr/src/lib/lvm/libmeta/common/meta_stat.c (revision 25cf1a301a396c38e8adf52c15f537b80d2483f7)
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 /*
24  * Copyright (c) 1992, 1993, 1994, 2000 by Sun Microsystems, Inc.
25  * All rights reserved.
26  */
27 
28 #pragma ident	"%Z%%M%	%I%	%E% SMI"
29 
30 /*
31  * Caching stat function
32  */
33 
34 #include <meta.h>
35 
36 #define	MD_NUM_STAT_HEAD	16
37 
38 struct statcache {
39 	struct statcache	*sc_next;
40 	struct stat		sc_stat;
41 	char			*sc_filename;
42 };
43 
44 static struct statcache	*statcache_head[MD_NUM_STAT_HEAD] =
45 	{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
46 
47 int
48 meta_stat(const char *filename, struct stat *sbp)
49 {
50 	struct statcache	*scp;
51 	int			 hash;
52 	char			*cp;
53 
54 	hash = 0;
55 	for (cp = (char *)filename; *cp != 0; cp++)
56 		hash += *cp;
57 
58 	hash &= 0xf;
59 
60 	for (scp = statcache_head[hash]; scp != NULL; scp = scp->sc_next)
61 		if (strcmp(filename, scp->sc_filename) == 0)
62 			break;
63 	if (scp) {
64 		(void) memcpy((caddr_t)sbp, (caddr_t)&scp->sc_stat,
65 		    sizeof (*sbp));
66 		return (0);
67 	}
68 	if (stat(filename, sbp) != 0)
69 		return (-1);
70 
71 	if (!S_ISBLK(sbp->st_mode) && !S_ISCHR(sbp->st_mode))
72 		return (-1);
73 
74 	scp = (struct statcache *)malloc(sizeof (*scp));
75 	if (scp != NULL) {
76 		(void) memcpy((caddr_t)&scp->sc_stat, (caddr_t)sbp,
77 		    sizeof (*sbp));
78 		scp->sc_filename = strdup(filename);
79 		if (scp->sc_filename == NULL) {
80 			free((char *)scp);
81 			return (0);
82 		}
83 		scp->sc_next = statcache_head[hash];
84 		statcache_head[hash] = scp;
85 	}
86 	return (0);
87 }
88 
89 void
90 metaflushstatcache(void)
91 {
92 	struct statcache	*p, *n;
93 	int			i;
94 
95 	for (i = 0; i < MD_NUM_STAT_HEAD; i++) {
96 		for (p = statcache_head[i], n = NULL; p != NULL; p = n) {
97 			n = p->sc_next;
98 			Free(p->sc_filename);
99 			Free(p);
100 		}
101 		statcache_head[i] = NULL;
102 	}
103 }
104