X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Fxfs%2Fxfs_bit.c;h=43be6a7e47c6ed1a1b582cb8d91416ae84fa8c25;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=38fece1f7e24f07e56ccd839c070b7161d49faa0;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git diff --git a/fs/xfs/xfs_bit.c b/fs/xfs/xfs_bit.c index 38fece1f7..43be6a7e4 100644 --- a/fs/xfs/xfs_bit.c +++ b/fs/xfs/xfs_bit.c @@ -1,51 +1,35 @@ /* - * Copyright (c) 2000-2002 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. */ -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 */ @@ -154,14 +138,17 @@ int xfs_lowbit64( __uint64_t v) { - int n; - n = ffs((unsigned)v); - if (n <= 0) { - n = ffs(v >> 32); - if (n >= 0) - n+=32; + __uint32_t w = (__uint32_t)v; + int n = 0; + + if (w) { /* lower bits */ + n = ffs(w); + } else { /* upper bits */ + w = (__uint32_t)(v >> 32); + if (w && (n = ffs(w))) + n += 32; } - return (n <= 0) ? n : n-1; + return n - 1; } /* @@ -171,10 +158,11 @@ int xfs_highbit64( __uint64_t v) { - __uint32_t h = v >> 32; + __uint32_t h = (__uint32_t)(v >> 32); + if (h) return xfs_highbit32(h) + 32; - return xfs_highbit32((__u32)v); + return xfs_highbit32((__uint32_t)v); } @@ -238,32 +226,33 @@ xfs_count_bits(uint *map, uint size, uint start_bit) int xfs_contig_bits(uint *map, uint size, uint start_bit) { -#if BITS_PER_LONG == 32 - return find_next_zero_bit((unsigned long *)map, - size * sizeof(uint) * 8, start_bit) - start_bit; -#else - /* - * The first argument to find_next_zero_bit needs to be aligned, - * but this is coming from the xfs_buf_log_format_t on-disk - * struct, which can't be padded or otherwise modified w/o breaking - * on-disk compatibility... so create a temporary, aligned - * variable, copy over the bitmap, and send that to find_next_zero_bit - * This only happens in recovery, so it's ugly but not too bad. - */ - void * addr; - int bit; - size_t bitmap_size = size * sizeof(uint); - - addr = (void *)kmem_alloc(bitmap_size, KM_SLEEP); - memcpy(addr, map, size * sizeof(uint)); - - bit = find_next_zero_bit((unsigned long *)addr, - size * sizeof(uint) * 8, start_bit) - start_bit; + uint * p = ((unsigned int *) map) + (start_bit >> BIT_TO_WORD_SHIFT); + uint result = 0; + uint tmp; - kmem_free(addr, bitmap_size); + size <<= BIT_TO_WORD_SHIFT; - return bit; -#endif + ASSERT(start_bit < size); + size -= start_bit & ~(NBWORD - 1); + start_bit &= (NBWORD - 1); + if (start_bit) { + tmp = *p++; + /* set to one first offset bits prior to start */ + tmp |= (~0U >> (NBWORD-start_bit)); + if (tmp != ~0U) + goto found; + result += NBWORD; + size -= NBWORD; + } + while (size) { + if ((tmp = *p++) != ~0U) + goto found; + result += NBWORD; + size -= NBWORD; + } + return result - start_bit; +found: + return result + ffz(tmp) - start_bit; } /* @@ -288,25 +277,20 @@ int xfs_next_bit(uint *map, uint size, uint start_bit) start_bit &= (NBWORD - 1); if (start_bit) { tmp = *p++; - /* set to zero first offset bits */ + /* set to zero first offset bits prior to start */ tmp &= (~0U << start_bit); - if (size < NBWORD) - goto found_first; if (tmp != 0U) - goto found_middle; - size -= NBWORD; + goto found; result += NBWORD; + size -= NBWORD; } - while (size >= NBWORD) { + while (size) { if ((tmp = *p++) != 0U) - goto found_middle; + goto found; result += NBWORD; size -= NBWORD; } - if (!size) - return -1; - tmp = *p; -found_first: -found_middle: + return -1; +found: return result + ffs(tmp) - 1; }