X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fxfs%2Fxfs_bit.c;h=fab0b6d5a41be3916ac8893a2f82f142cd4443f4;hb=92d499d991ec4f5cbd00d6f33967eab9d3ee8d6c;hp=76c9ad3875ef8aeb6574475676fca2cf257cf329;hpb=a8b3e6f10f08f66ae1072efd087b30966a3654f6;p=linux-2.6 diff --git a/fs/xfs/xfs_bit.c b/fs/xfs/xfs_bit.c index 76c9ad3875..fab0b6d5a4 100644 --- a/fs/xfs/xfs_bit.c +++ b/fs/xfs/xfs_bit.c @@ -1,51 +1,35 @@ /* - * Copyright (c) 2000-2004 Silicon Graphics, Inc. All Rights Reserved. + * Copyright (c) 2000-2005 Silicon Graphics, Inc. + * All Rights Reserved. * - * This program is free software; you can redistribute it and/or modify it - * under the terms of version 2 of the GNU General Public License as + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation. * - * This program is distributed in the hope that it would be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * This program is distributed in the hope that it would 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. * - * Further, this software is distributed without any warranty that it is - * free of the rightful claim of any third person regarding infringement - * or the like. Any license provided herein, whether implied or - * otherwise, applies only to this software file. Patent licenses, if - * any, provided herein do not apply to combinations of this program with - * other software, or any other product whatsoever. - * - * You should have received a copy of the GNU General Public License along - * with this program; if not, write the Free Software Foundation, Inc., 59 - * Temple Place - Suite 330, Boston MA 02111-1307, USA. - * - * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy, - * Mountain View, CA 94043, or: - * - * http://www.sgi.com - * - * For further information regarding this notice, see: - * - * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/ - */ - -/* - * XFS bit manipulation routines, used in non-realtime code. + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ - #include "xfs.h" #include "xfs_bit.h" #include "xfs_log.h" #include "xfs_trans.h" #include "xfs_buf_item.h" +/* + * XFS bit manipulation routines, used in non-realtime code. + */ #ifndef HAVE_ARCH_HIGHBIT /* * Index of high bit number in byte, -1 for none set, 0..7 otherwise. */ -STATIC const char xfs_highbit[256] = { +static const char xfs_highbit[256] = { -1, 0, 1, 1, 2, 2, 2, 2, /* 00 .. 07 */ 3, 3, 3, 3, 3, 3, 3, 3, /* 08 .. 0f */ 4, 4, 4, 4, 4, 4, 4, 4, /* 10 .. 17 */ @@ -81,44 +65,6 @@ STATIC const char xfs_highbit[256] = { }; #endif -/* - * Count of bits set in byte, 0..8. - */ -static const char xfs_countbit[256] = { - 0, 1, 1, 2, 1, 2, 2, 3, /* 00 .. 07 */ - 1, 2, 2, 3, 2, 3, 3, 4, /* 08 .. 0f */ - 1, 2, 2, 3, 2, 3, 3, 4, /* 10 .. 17 */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 18 .. 1f */ - 1, 2, 2, 3, 2, 3, 3, 4, /* 20 .. 27 */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 28 .. 2f */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 30 .. 37 */ - 3, 4, 4, 5, 4, 5, 5, 6, /* 38 .. 3f */ - 1, 2, 2, 3, 2, 3, 3, 4, /* 40 .. 47 */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 48 .. 4f */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 50 .. 57 */ - 3, 4, 4, 5, 4, 5, 5, 6, /* 58 .. 5f */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 60 .. 67 */ - 3, 4, 4, 5, 4, 5, 5, 6, /* 68 .. 6f */ - 3, 4, 4, 5, 4, 5, 5, 6, /* 70 .. 77 */ - 4, 5, 5, 6, 5, 6, 6, 7, /* 78 .. 7f */ - 1, 2, 2, 3, 2, 3, 3, 4, /* 80 .. 87 */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 88 .. 8f */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 90 .. 97 */ - 3, 4, 4, 5, 4, 5, 5, 6, /* 98 .. 9f */ - 2, 3, 3, 4, 3, 4, 4, 5, /* a0 .. a7 */ - 3, 4, 4, 5, 4, 5, 5, 6, /* a8 .. af */ - 3, 4, 4, 5, 4, 5, 5, 6, /* b0 .. b7 */ - 4, 5, 5, 6, 5, 6, 6, 7, /* b8 .. bf */ - 2, 3, 3, 4, 3, 4, 4, 5, /* c0 .. c7 */ - 3, 4, 4, 5, 4, 5, 5, 6, /* c8 .. cf */ - 3, 4, 4, 5, 4, 5, 5, 6, /* d0 .. d7 */ - 4, 5, 5, 6, 5, 6, 6, 7, /* d8 .. df */ - 3, 4, 4, 5, 4, 5, 5, 6, /* e0 .. e7 */ - 4, 5, 5, 6, 5, 6, 6, 7, /* e8 .. ef */ - 4, 5, 5, 6, 5, 6, 6, 7, /* f0 .. f7 */ - 5, 6, 6, 7, 6, 7, 7, 8, /* f8 .. ff */ -}; - /* * xfs_highbit32: get high bit set out of 32-bit argument, -1 if none set. */ @@ -183,56 +129,21 @@ xfs_highbit64( /* - * Count the number of bits set in the bitmap starting with bit - * start_bit. Size is the size of the bitmap in words. - * - * Do the counting by mapping a byte value to the number of set - * bits for that value using the xfs_countbit array, i.e. - * xfs_countbit[0] == 0, xfs_countbit[1] == 1, xfs_countbit[2] == 1, - * xfs_countbit[3] == 2, etc. + * Return whether bitmap is empty. + * Size is number of words in the bitmap, which is padded to word boundary + * Returns 1 for empty, 0 for non-empty. */ int -xfs_count_bits(uint *map, uint size, uint start_bit) +xfs_bitmap_empty(uint *map, uint size) { - register int bits; - register unsigned char *bytep; - register unsigned char *end_map; - int byte_bit; - - bits = 0; - end_map = (char*)(map + size); - bytep = (char*)(map + (start_bit & ~0x7)); - byte_bit = start_bit & 0x7; - - /* - * If the caller fell off the end of the map, return 0. - */ - if (bytep >= end_map) { - return (0); - } - - /* - * If start_bit is not byte aligned, then process the - * first byte separately. - */ - if (byte_bit != 0) { - /* - * Shift off the bits we don't want to look at, - * before indexing into xfs_countbit. - */ - bits += xfs_countbit[(*bytep >> byte_bit)]; - bytep++; - } + uint i; + uint ret = 0; - /* - * Count the bits in each byte until the end of the bitmap. - */ - while (bytep < end_map) { - bits += xfs_countbit[*bytep]; - bytep++; + for (i = 0; i < size; i++) { + ret |= map[i]; } - return (bits); + return (ret == 0); } /*