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Diffstat (limited to 'fs/gfs2/bits.c')
| -rw-r--r-- | fs/gfs2/bits.c | 182 |
1 files changed, 0 insertions, 182 deletions
diff --git a/fs/gfs2/bits.c b/fs/gfs2/bits.c deleted file mode 100644 index 49585e3de095..000000000000 --- a/fs/gfs2/bits.c +++ /dev/null @@ -1,182 +0,0 @@ -/* - * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. - * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. - * - * This copyrighted material is made available to anyone wishing to use, - * modify, copy, or redistribute it subject to the terms and conditions - * of the GNU General Public License v.2. - */ - -/* - * These routines are used by the resource group routines (rgrp.c) - * to keep track of block allocation. Each block is represented by two - * bits. One bit indicates whether or not the block is used. (1=used, - * 0=free) The other bit indicates whether or not the block contains a - * dinode or not. (1=dinode, 0=not-dinode) So, each byte represents - * GFS2_NBBY (i.e. 4) blocks. - */ - -#include <linux/sched.h> -#include <linux/slab.h> -#include <linux/spinlock.h> -#include <linux/completion.h> -#include <linux/buffer_head.h> -#include <linux/gfs2_ondisk.h> -#include <asm/semaphore.h> - -#include "gfs2.h" -#include "lm_interface.h" -#include "incore.h" -#include "bits.h" -#include "util.h" - -static const char valid_change[16] = { - /* current */ - /* n */ 0, 1, 0, 1, - /* e */ 1, 0, 0, 0, - /* w */ 0, 0, 0, 0, - 1, 0, 0, 0 -}; - -/** - * gfs2_setbit - Set a bit in the bitmaps - * @buffer: the buffer that holds the bitmaps - * @buflen: the length (in bytes) of the buffer - * @block: the block to set - * @new_state: the new state of the block - * - */ - -void gfs2_setbit(struct gfs2_rgrpd *rgd, unsigned char *buffer, - unsigned int buflen, uint32_t block, unsigned char new_state) -{ - unsigned char *byte, *end, cur_state; - unsigned int bit; - - byte = buffer + (block / GFS2_NBBY); - bit = (block % GFS2_NBBY) * GFS2_BIT_SIZE; - end = buffer + buflen; - - gfs2_assert(rgd->rd_sbd, byte < end); - - cur_state = (*byte >> bit) & GFS2_BIT_MASK; - - if (valid_change[new_state * 4 + cur_state]) { - *byte ^= cur_state << bit; - *byte |= new_state << bit; - } else - gfs2_consist_rgrpd(rgd); -} - -/** - * gfs2_testbit - test a bit in the bitmaps - * @buffer: the buffer that holds the bitmaps - * @buflen: the length (in bytes) of the buffer - * @block: the block to read - * - */ - -unsigned char gfs2_testbit(struct gfs2_rgrpd *rgd, unsigned char *buffer, - unsigned int buflen, uint32_t block) -{ - unsigned char *byte, *end, cur_state; - unsigned int bit; - - byte = buffer + (block / GFS2_NBBY); - bit = (block % GFS2_NBBY) * GFS2_BIT_SIZE; - end = buffer + buflen; - - gfs2_assert(rgd->rd_sbd, byte < end); - - cur_state = (*byte >> bit) & GFS2_BIT_MASK; - - return cur_state; -} - -/** - * gfs2_bitfit - Search an rgrp's bitmap buffer to find a bit-pair representing - * a block in a given allocation state. - * @buffer: the buffer that holds the bitmaps - * @buflen: the length (in bytes) of the buffer - * @goal: start search at this block's bit-pair (within @buffer) - * @old_state: GFS2_BLKST_XXX the state of the block we're looking for; - * bit 0 = alloc(1)/free(0), bit 1 = meta(1)/data(0) - * - * Scope of @goal and returned block number is only within this bitmap buffer, - * not entire rgrp or filesystem. @buffer will be offset from the actual - * beginning of a bitmap block buffer, skipping any header structures. - * - * Return: the block number (bitmap buffer scope) that was found - */ - -uint32_t gfs2_bitfit(struct gfs2_rgrpd *rgd, unsigned char *buffer, - unsigned int buflen, uint32_t goal, - unsigned char old_state) -{ - unsigned char *byte, *end, alloc; - uint32_t blk = goal; - unsigned int bit; - - byte = buffer + (goal / GFS2_NBBY); - bit = (goal % GFS2_NBBY) * GFS2_BIT_SIZE; - end = buffer + buflen; - alloc = (old_state & 1) ? 0 : 0x55; - - while (byte < end) { - if ((*byte & 0x55) == alloc) { - blk += (8 - bit) >> 1; - - bit = 0; - byte++; - - continue; - } - - if (((*byte >> bit) & GFS2_BIT_MASK) == old_state) - return blk; - - bit += GFS2_BIT_SIZE; - if (bit >= 8) { - bit = 0; - byte++; - } - - blk++; - } - - return BFITNOENT; -} - -/** - * gfs2_bitcount - count the number of bits in a certain state - * @buffer: the buffer that holds the bitmaps - * @buflen: the length (in bytes) of the buffer - * @state: the state of the block we're looking for - * - * Returns: The number of bits - */ - -uint32_t gfs2_bitcount(struct gfs2_rgrpd *rgd, unsigned char *buffer, - unsigned int buflen, unsigned char state) -{ - unsigned char *byte = buffer; - unsigned char *end = buffer + buflen; - unsigned char state1 = state << 2; - unsigned char state2 = state << 4; - unsigned char state3 = state << 6; - uint32_t count = 0; - - for (; byte < end; byte++) { - if (((*byte) & 0x03) == state) - count++; - if (((*byte) & 0x0C) == state1) - count++; - if (((*byte) & 0x30) == state2) - count++; - if (((*byte) & 0xC0) == state3) - count++; - } - - return count; -} - |