xref: /freebsd/tools/diag/dumpvfscache/dumpvfscache.c (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <unistd.h>
4 #include <fcntl.h>
5 #include <kvm.h>
6 #include <nlist.h>
7 #include <sysexits.h>
8 #include <sys/uio.h>
9 #include <sys/namei.h>
10 #include <sys/param.h>
11 #include <sys/queue.h>
12 #include <sys/time.h>
13 #include <sys/vnode.h>
14 /*----------------------------------*/
15 static u_int crc16_table[16] = {
16     0x0000, 0xCC01, 0xD801, 0x1400,
17     0xF001, 0x3C00, 0x2800, 0xE401,
18     0xA001, 0x6C00, 0x7800, 0xB401,
19     0x5000, 0x9C01, 0x8801, 0x4400
20 };
21 
22 /* XXX Taken from sys/kern/vfs_cache.c */
23 struct	namecache {
24 	LIST_ENTRY(namecache) nc_hash;
25 	LIST_ENTRY(namecache) nc_src;
26 	TAILQ_ENTRY(namecache) nc_dst;
27 	struct	vnode *nc_dvp;
28 	struct	vnode *nc_vp;
29 	u_char	nc_flag;
30 	u_char	nc_nlen;
31 	char	nc_name[0];
32 };
33 
34 static u_short
35 wlpsacrc(u_char *buf, u_int len)
36 {
37     u_short     crc = 0;
38     int         i, r1;
39 
40     for (i = 0; i < len; i++, buf++) {
41         /* lower 4 bits */
42         r1 = crc16_table[crc & 0xF];
43         crc = (crc >> 4) & 0x0FFF;
44         crc = crc ^ r1 ^ crc16_table[*buf & 0xF];
45 
46         /* upper 4 bits */
47         r1 = crc16_table[crc & 0xF];
48         crc = (crc >> 4) & 0x0FFF;
49         crc = crc ^ r1 ^ crc16_table[(*buf >> 4) & 0xF];
50     }
51     return(crc);
52 }
53 
54 /*----------------------------------*/
55 struct nlist nl[] = {
56 	{ "_nchash", 0},
57 	{ "_nchashtbl", 0},
58 	{ 0, 0 },
59 };
60 
61 int histo[2047];
62 int histn[2047];
63 int *newbucket;
64 
65 int
66 main(int argc, char **argv)
67 {
68 	int nchash, i, j, k, kn;
69 	int nb, p1, p2;
70 	u_long p;
71 	LIST_HEAD(nchashhead, namecache) *nchashtbl;
72 	struct namecache *nc;
73 	struct vnode vn;
74 
75 	kvm_t *kvm = kvm_open(NULL, NULL, NULL, O_RDONLY, argv[0]);
76 	if (kvm == NULL)
77 		return(EX_OSERR);
78 
79 	printf("kvm: %p\n", kvm);
80 	printf("kvm_nlist: %d\n", kvm_nlist(kvm, nl));
81 	kvm_read(kvm, nl[0].n_value, &nchash, sizeof nchash);
82 	nchash++;
83 	nchashtbl = malloc(nchash * sizeof *nchashtbl);
84 	nc = malloc(sizeof *nc + NAME_MAX);
85 	newbucket = malloc(nchash * sizeof (int));
86 	memset(newbucket, 0, nchash * sizeof (int));
87 	kvm_read(kvm, nl[1].n_value, &p, sizeof p);
88 	kvm_read(kvm, p, nchashtbl, nchash * sizeof *nchashtbl);
89 	for (i=0; i < nchash; i++) {
90 #if 0
91 		printf("%d\n", i);
92 #endif
93 		nb=0;
94 		p = (u_long)LIST_FIRST(nchashtbl+i);
95 		while (p) {
96 			nb++;
97 			kvm_read(kvm, p, nc, sizeof *nc + NAME_MAX);
98 			kvm_read(kvm, (u_long)nc->nc_dvp, &vn, sizeof vn);
99 			nc->nc_name[nc->nc_nlen] = '\0';
100 			for (j=k=kn=0;nc->nc_name[j];j++) {
101 				k+= nc->nc_name[j];
102 				kn <<= 1;
103 				kn+= nc->nc_name[j];
104 			}
105 			/*
106 			kn = k;
107 			*/
108 			kn = wlpsacrc(nc->nc_name,nc->nc_nlen);
109 
110 			/* kn += (u_long)vn.v_data >> 8;  */
111 			/* kn += (u_long)nc->nc_dvp >> 7;    */
112 			kn += vn.v_id;
113 			kn &= (nchash - 1);
114 			newbucket[kn]++;
115 #if 1
116 			printf("%4d  dvp %08x  hash %08x  vp %08x  id %08x  name <%s>\n",
117 				i,nc->nc_dvp, k, nc->nc_vp, vn.v_id, nc->nc_name);
118 #endif
119 			p = (u_long)LIST_NEXT(nc, nc_hash);
120 		}
121 		histo[nb]++;
122 	}
123 	for (i=0; i < nchash; i++) {
124 		histn[newbucket[i]]++;
125 	}
126 	p1=p2 = 0;
127 	for (i=0;i<30;i++) {
128 		p1 += histo[i] * i;
129 		p2 += histn[i] * i;
130 		if (histo[i] || histn[i])
131 			printf("H%02d %4d %4d / %4d %4d\n",i,histo[i], p1 , histn[i], p2);
132 	}
133 
134 	return (0);
135 }
136 
137