447be3f1e4
Strong candidate for backport to 6.x. When allocating new blocks, the search for block group beginnings would fail with a segfault. There was a side-effect read access with an off-by-one errors. The results were not used in the error case so the code worked in the past. But now the FreeBSD kernel has tighter mappings and the word accessed is not mapped (for me). The Linux kernel has rewritten most of the allocation strategy by now. Also, the Linux kernel cleaned up the integration of these files and it look feasable to wrap the original Linux files in wrapper that provides their favorite arguments instead of dragging around our own code.
115 lines
2.7 KiB
C
115 lines
2.7 KiB
C
/*-
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* Copyright (c) 2003 Marcel Moolenaar
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef _SYS_GNU_EXT2FS_EXT2_BITOPS_H_
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#define _SYS_GNU_EXT2FS_EXT2_BITOPS_H_
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#define find_first_zero_bit(data, sz) find_next_zero_bit(data, sz, 0)
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static __inline int
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clear_bit(int no, void *data)
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{
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uint32_t *p;
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uint32_t mask, new, old;
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p = (uint32_t*)data + (no >> 5);
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mask = (1U << (no & 31));
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do {
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old = *p;
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new = old & ~mask;
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} while (!atomic_cmpset_32(p, old, new));
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return (old & mask);
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}
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static __inline int
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set_bit(int no, void *data)
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{
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uint32_t *p;
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uint32_t mask, new, old;
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p = (uint32_t*)data + (no >> 5);
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mask = (1U << (no & 31));
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do {
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old = *p;
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new = old | mask;
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} while (!atomic_cmpset_32(p, old, new));
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return (old & mask);
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}
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static __inline int
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test_bit(int no, void *data)
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{
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uint32_t *p;
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uint32_t mask;
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p = (uint32_t*)data + (no >> 5);
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mask = (1U << (no & 31));
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return (*p & mask);
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}
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static __inline size_t
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find_next_zero_bit(void *data, size_t sz, size_t ofs)
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{
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uint32_t *p;
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uint32_t mask;
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int bit;
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p = (uint32_t*)data + (ofs >> 5);
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if (ofs & 31) {
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mask = ~0U << (ofs & 31);
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bit = *p | ~mask;
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if (bit != ~0U)
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return (ffs(~bit) + ofs - 1);
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p++;
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ofs = (ofs + 31U) & ~31U;
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}
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while(ofs < sz && *p == ~0U) {
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p++;
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ofs += 32;
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}
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if (ofs == sz)
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return (ofs);
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bit = *p;
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return (ffs(~bit) + ofs - 1);
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}
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static __inline void *
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memscan(void *data, int c, size_t sz)
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{
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uint8_t *p;
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p = data;
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while (sz && *p != c) {
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p++;
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sz--;
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}
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return (p);
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}
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#endif /* _SYS_GNU_EXT2FS_EXT2_BITOPS_H_ */
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