dab291af8d
Reworked from a patch by Mingming Cao and Randy Dunlap Signed-off-By: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
33 lines
697 B
C
33 lines
697 B
C
/*
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* linux/fs/ext4/bitmap.c
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*
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* Copyright (C) 1992, 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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*/
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#include <linux/buffer_head.h>
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#include <linux/jbd2.h>
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#include <linux/ext4_fs.h>
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#ifdef EXT4FS_DEBUG
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static int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
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unsigned long ext4_count_free (struct buffer_head * map, unsigned int numchars)
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{
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unsigned int i;
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unsigned long sum = 0;
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if (!map)
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return (0);
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for (i = 0; i < numchars; i++)
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sum += nibblemap[map->b_data[i] & 0xf] +
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nibblemap[(map->b_data[i] >> 4) & 0xf];
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return (sum);
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}
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#endif /* EXT4FS_DEBUG */
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