-/*
- * Copyright (C) 2002 by Theodore Ts'o
- *
- * This file is released under the GPL v2.
- *
- * This file may be redistributed under the terms of the GNU Public
- * License.
- */
-
-/*
- * obdclass/hash.c is copied from ldiskfs/hash.c.
- * ldiskfs is used by server only.
- * obdclass is shared by both client and server, it should not depend on ldiskfs.
- */
-
-#include <linux/fs.h>
-#include <linux/sched.h>
-#ifdef HAVE_SERVER_SUPPORT
-
-#ifdef HAVE_EXT4_LDISKFS
-#include <ldiskfs/ldiskfs_jbd2.h>
-#include <ldiskfs/ldiskfs.h>
-#else
-#include <linux/jbd.h>
-#include <linux/ldiskfs_fs.h>
-#endif
-
-#else
-# include <obd_class.h>
-#endif
-
-#define DELTA 0x9E3779B9
-
-
-static void TEA_transform(__u32 buf[4], __u32 const in[])
-{
- __u32 sum = 0;
- __u32 b0 = buf[0], b1 = buf[1];
- __u32 a = in[0], b = in[1], c = in[2], d = in[3];
- int n = 16;
-
- do {
- sum += DELTA;
- b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b);
- b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d);
- } while(--n);
-
- buf[0] += b0;
- buf[1] += b1;
-}
-
-/* F, G and H are basic MD4 functions: selection, majority, parity */
-#define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
-#define G(x, y, z) (((x) & (y)) + (((x) ^ (y)) & (z)))
-#define H(x, y, z) ((x) ^ (y) ^ (z))
-
-/*
- * The generic round function. The application is so specific that
- * we don't bother protecting all the arguments with parens, as is generally
- * good macro practice, in favor of extra legibility.
- * Rotation is separate from addition to prevent recomputation
- */
-#define ROUND(f, a, b, c, d, x, s) \
- (a += f(b, c, d) + x, a = (a << s) | (a >> (32-s)))
-#define K1 0
-#define K2 013240474631UL
-#define K3 015666365641UL
-
-/*
- * Basic cut-down MD4 transform. Returns only 32 bits of result.
- */
-static void halfMD4Transform (__u32 buf[4], __u32 const in[])
-{
- __u32 a = buf[0], b = buf[1], c = buf[2], d = buf[3];
-
- /* Round 1 */
- ROUND(F, a, b, c, d, in[0] + K1, 3);
- ROUND(F, d, a, b, c, in[1] + K1, 7);
- ROUND(F, c, d, a, b, in[2] + K1, 11);
- ROUND(F, b, c, d, a, in[3] + K1, 19);
- ROUND(F, a, b, c, d, in[4] + K1, 3);
- ROUND(F, d, a, b, c, in[5] + K1, 7);
- ROUND(F, c, d, a, b, in[6] + K1, 11);
- ROUND(F, b, c, d, a, in[7] + K1, 19);
-
- /* Round 2 */
- ROUND(G, a, b, c, d, in[1] + K2, 3);
- ROUND(G, d, a, b, c, in[3] + K2, 5);
- ROUND(G, c, d, a, b, in[5] + K2, 9);
- ROUND(G, b, c, d, a, in[7] + K2, 13);
- ROUND(G, a, b, c, d, in[0] + K2, 3);
- ROUND(G, d, a, b, c, in[2] + K2, 5);
- ROUND(G, c, d, a, b, in[4] + K2, 9);
- ROUND(G, b, c, d, a, in[6] + K2, 13);
-
- /* Round 3 */
- ROUND(H, a, b, c, d, in[3] + K3, 3);
- ROUND(H, d, a, b, c, in[7] + K3, 9);
- ROUND(H, c, d, a, b, in[2] + K3, 11);
- ROUND(H, b, c, d, a, in[6] + K3, 15);
- ROUND(H, a, b, c, d, in[1] + K3, 3);
- ROUND(H, d, a, b, c, in[5] + K3, 9);
- ROUND(H, c, d, a, b, in[0] + K3, 11);
- ROUND(H, b, c, d, a, in[4] + K3, 15);
-
- buf[0] += a;
- buf[1] += b;
- buf[2] += c;
- buf[3] += d;
-}
-
-#undef ROUND
-#undef F
-#undef G
-#undef H
-#undef K1
-#undef K2
-#undef K3
-
-/* The old legacy hash */
-static __u32 dx_hack_hash (const char *name, int len)
-{
- __u32 hash0 = 0x12a3fe2d, hash1 = 0x37abe8f9;
- while (len--) {
- __u32 hash = hash1 + (hash0 ^ (*name++ * 7152373));
-
- if (hash & 0x80000000) hash -= 0x7fffffff;
- hash1 = hash0;
- hash0 = hash;
- }
- return (hash0 << 1);
-}
-
-static void str2hashbuf(const char *msg, int len, __u32 *buf, int num)
-{
- __u32 pad, val;
- int i;
-
- pad = (__u32)len | ((__u32)len << 8);
- pad |= pad << 16;
-
- val = pad;
- if (len > num*4)
- len = num * 4;
- for (i=0; i < len; i++) {
- if ((i % 4) == 0)
- val = pad;
- val = msg[i] + (val << 8);
- if ((i % 4) == 3) {
- *buf++ = val;
- val = pad;
- num--;
- }
- }
- if (--num >= 0)
- *buf++ = val;
- while (--num >= 0)
- *buf++ = pad;
-}
-
-/*
- * Returns the hash of a filename. If len is 0 and name is NULL, then
- * this function can be used to test whether or not a hash version is
- * supported.
- *
- * The seed is an 4 longword (32 bits) "secret" which can be used to
- * uniquify a hash. If the seed is all zero's, then some default seed
- * may be used.
- *
- * A particular hash version specifies whether or not the seed is
- * represented, and whether or not the returned hash is 32 bits or 64
- * bits. 32 bit hashes will return 0 for the minor hash.
- */
-int ldiskfsfs_dirhash(const char *name, int len, struct ldiskfs_dx_hash_info *hinfo)
-{
- __u32 hash;
- __u32 minor_hash = 0;
- const char *p;
- int i;
- __u32 in[8], buf[4];
-
- /* Initialize the default seed for the hash checksum functions */
- buf[0] = 0x67452301;
- buf[1] = 0xefcdab89;
- buf[2] = 0x98badcfe;
- buf[3] = 0x10325476;
-
- /* Check to see if the seed is all zero's */
- if (hinfo->seed) {
- for (i=0; i < 4; i++) {
- if (hinfo->seed[i])
- break;
- }
- if (i < 4)
- memcpy(buf, hinfo->seed, sizeof(buf));
- }
-
- switch (hinfo->hash_version) {
- case LDISKFS_DX_HASH_LEGACY:
- hash = dx_hack_hash(name, len);
- break;
- case LDISKFS_DX_HASH_HALF_MD4:
- p = name;
- while (len > 0) {
- str2hashbuf(p, len, in, 8);
- halfMD4Transform(buf, in);
- len -= 32;
- p += 32;
- }
- minor_hash = buf[2];
- hash = buf[1];
- break;
- case LDISKFS_DX_HASH_TEA:
- p = name;
- while (len > 0) {
- str2hashbuf(p, len, in, 4);
- TEA_transform(buf, in);
- len -= 16;
- p += 16;
- }
- hash = buf[0];
- minor_hash = buf[1];
- break;
- default:
- hinfo->hash = 0;
- return -1;
- }
- hash = hash & ~1;
- if (hash == (LDISKFS_HTREE_EOF << 1))
- hash = (LDISKFS_HTREE_EOF-1) << 1;
- hinfo->hash = hash;
- hinfo->minor_hash = minor_hash;
- return 0;
-}
git://git.whamcloud.com / fs / lustre-release.git / commitdiff