X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=lustre%2Fobdclass%2Fmea.c;h=2e5946af08a25eeef8d4453e953bca8e1c02f6bb;hp=fa9ce2aa7ba4253e928135b07f5d6fc4e6f2472e;hb=82dff34569766e08218c395c04f428530ff7726e;hpb=fc4de168e941017bce61765080c15982cb33dd88 diff --git a/lustre/obdclass/mea.c b/lustre/obdclass/mea.c index fa9ce2a..2e5946a 100644 --- a/lustre/obdclass/mea.c +++ b/lustre/obdclass/mea.c @@ -1,76 +1,201 @@ /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*- * vim:expandtab:shiftwidth=8:tabstop=8: * - * Copyright (C) 2002, 2003 Cluster File Systems, Inc. + * GPL HEADER START * - * This file is part of Lustre, http://www.lustre.org. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * - * Lustre is free software; you can redistribute it and/or - * modify it under the terms of version 2 of the GNU General Public - * License as published by the Free Software Foundation. + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 only, + * as published by the Free Software Foundation. * - * Lustre is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License version 2 for more details (a copy is included + * in the LICENSE file that accompanied this code). * - * You should have received a copy of the GNU General Public License - * along with Lustre; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * You should have received a copy of the GNU General Public License + * version 2 along with this program; If not, see + * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + * GPL HEADER END + */ +/* + * Copyright 2008 Sun Microsystems, Inc. All rights reserved + * Use is subject to license terms. + */ +/* + * This file is part of Lustre, http://www.lustre.org/ + * Lustre is a trademark of Sun Microsystems, Inc. */ #define DEBUG_SUBSYSTEM S_CLASS +#include #ifdef __KERNEL__ #include /* for request_module() */ #include -#include #include #include #include -#else +#else #include -#include -#include +#include #endif -#include +#include +#include +#ifdef __KERNEL__ -int mea_name2idx(struct mea *mea, char *name, int namelen) -{ - unsigned int c; +#ifdef HAVE_EXT4_LDISKFS +#include +#else +#include +#endif - /* just to simplify caller code */ - if (mea == NULL) - return 0; +#ifdef HAVE_SERVER_SUPPORT +/* LDISKFS_SB() */ - if (mea->mea_count == 0) - return 0; +#ifdef HAVE_EXT4_LDISKFS +#include +#else +#include +#endif + +#endif +#endif +static int mea_last_char_hash(int count, char *name, int namelen) +{ + unsigned int c; - /* FIXME: real hash calculation here */ c = name[namelen - 1]; if (c == 0) CWARN("looks like wrong len is passed\n"); - c = c % mea->mea_count; - - LASSERT(c < mea->mea_count); + c = c % count; return c; } -int raw_name2idx(int count, const char *name, int namelen) +static int mea_all_chars_hash(int count, char *name, int namelen) { - unsigned int c; + unsigned int c = 0; + + while (--namelen >= 0) + c += name[namelen]; + c = c % count; + return c; +} + +#ifdef __KERNEL__ +/* This hash calculate method must be same as the lvar hash method */ + +#define LVAR_HASH_SANDWICH (0) +#define LVAR_HASH_PREFIX (0) + +static __u32 hash_build0(const char *name, int namelen) +{ + __u32 result; + + if (namelen == 0) + return 0; + if (strncmp(name, ".", 1) == 0 && namelen == 1) + return 1; + if (strncmp(name, "..", 2) == 0 && namelen == 2) + return 2; + + if (LVAR_HASH_PREFIX) { + result = 0; + strncpy((void *)&result, + name, min(namelen, (int)sizeof result)); + } else { + struct ldiskfs_dx_hash_info hinfo; + + hinfo.hash_version = LDISKFS_DX_HASH_TEA; + hinfo.seed = 0; + ldiskfsfs_dirhash(name, namelen, &hinfo); + result = hinfo.hash; + if (LVAR_HASH_SANDWICH) { + __u32 result2; + + hinfo.hash_version = LDISKFS_DX_HASH_TEA; + hinfo.seed = 0; + ldiskfsfs_dirhash(name, namelen, &hinfo); + result2 = hinfo.hash; + result = (0xfc000000 & result2) | (0x03ffffff & result); + } + } + + return result; +} + +enum { + HASH_GRAY_AREA = 1024 +}; + +static __u32 hash_build(const char *name, int namelen) +{ + __u32 hash; + + hash = (hash_build0(name, namelen) << 1) & MAX_HASH_SIZE_32; + if (hash > MAX_HASH_SIZE_32 - HASH_GRAY_AREA) + hash &= HASH_GRAY_AREA - 1; + return hash; +} + +static int mea_hash_segment(int count, const char *name, int namelen) +{ + __u32 hash; + + LASSERT(IS_PO2(MAX_HASH_SIZE_32 + 1)); + + hash = hash_build(name, namelen) / (MAX_HASH_SIZE_32 / count); + LASSERTF(hash < count, "hash %x count %d \n", hash, count); + + return hash; +} +#else +static int mea_hash_segment(int count, char *name, int namelen) +{ + return 0; +} +#endif +int raw_name2idx(int hashtype, int count, const char *name, int namelen) +{ + unsigned int c = 0; LASSERT(namelen > 0); if (count <= 1) return 0; - - /* FIXME: real hash calculation here */ - c = name[namelen - 1]; - if (c == 0) - CWARN("looks like wrong len is passed\n"); - c = c % count; + switch (hashtype) { + case MEA_MAGIC_LAST_CHAR: + c = mea_last_char_hash(count, (char *)name, namelen); + break; + case MEA_MAGIC_ALL_CHARS: + c = mea_all_chars_hash(count, (char *)name, namelen); + break; + case MEA_MAGIC_HASH_SEGMENT: + c = mea_hash_segment(count, (char *)name, namelen); + break; + default: + CERROR("Unknown hash type 0x%x\n", hashtype); + } + LASSERT(c < count); return c; } +int mea_name2idx(struct lmv_stripe_md *mea, const char *name, int namelen) +{ + unsigned int c; + + LASSERT(mea && mea->mea_count); + + c = raw_name2idx(mea->mea_magic, mea->mea_count, name, namelen); + + LASSERT(c < mea->mea_count); + return c; +}