| 1 |
199 |
simons |
/*
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| 2 |
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* linux/fs/sysv/balloc.c
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| 3 |
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*
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| 4 |
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* minix/bitmap.c
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| 5 |
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* Copyright (C) 1991, 1992 Linus Torvalds
|
| 6 |
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*
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| 7 |
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* ext/freelists.c
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| 8 |
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* Copyright (C) 1992 Remy Card (card@masi.ibp.fr)
|
| 9 |
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*
|
| 10 |
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* xenix/alloc.c
|
| 11 |
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* Copyright (C) 1992 Doug Evans
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| 12 |
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*
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| 13 |
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* coh/alloc.c
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| 14 |
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* Copyright (C) 1993 Pascal Haible, Bruno Haible
|
| 15 |
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*
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| 16 |
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* sysv/balloc.c
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| 17 |
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* Copyright (C) 1993 Bruno Haible
|
| 18 |
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*
|
| 19 |
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* This file contains code for allocating/freeing blocks.
|
| 20 |
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*/
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| 21 |
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| 22 |
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#include <linux/kernel.h>
|
| 23 |
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#include <linux/fs.h>
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| 24 |
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#include <linux/sysv_fs.h>
|
| 25 |
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#include <linux/string.h>
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| 26 |
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#include <linux/locks.h>
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| 27 |
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| 28 |
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/* We don't trust the value of
|
| 29 |
|
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sb->sv_sbd2->s_tfree = *sb->sv_sb_total_free_blocks
|
| 30 |
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but we nevertheless keep it up to date. */
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| 31 |
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| 32 |
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void sysv_free_block(struct super_block * sb, unsigned int block)
|
| 33 |
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{
|
| 34 |
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struct buffer_head * bh;
|
| 35 |
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char * bh_data;
|
| 36 |
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|
| 37 |
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if (!sb) {
|
| 38 |
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printk("sysv_free_block: trying to free block on nonexistent device\n");
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| 39 |
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return;
|
| 40 |
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}
|
| 41 |
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if (block < sb->sv_firstdatazone || block >= sb->sv_nzones) {
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| 42 |
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printk("sysv_free_block: trying to free block not in datazone\n");
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| 43 |
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return;
|
| 44 |
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}
|
| 45 |
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lock_super(sb);
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| 46 |
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if (*sb->sv_sb_flc_count > sb->sv_flc_size) {
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| 47 |
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printk("sysv_free_block: flc_count > flc_size\n");
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| 48 |
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unlock_super(sb);
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| 49 |
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return;
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| 50 |
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}
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| 51 |
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/* If the free list head in super-block is full, it is copied
|
| 52 |
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* into this block being freed:
|
| 53 |
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*/
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| 54 |
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if (*sb->sv_sb_flc_count == sb->sv_flc_size) {
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| 55 |
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unsigned short * flc_count;
|
| 56 |
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unsigned long * flc_blocks;
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| 57 |
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|
| 58 |
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bh = sv_getblk(sb, sb->s_dev, block);
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| 59 |
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if (!bh) {
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| 60 |
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printk("sysv_free_block: getblk() failed\n");
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| 61 |
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unlock_super(sb);
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| 62 |
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return;
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| 63 |
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}
|
| 64 |
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bh_data = bh->b_data;
|
| 65 |
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switch (sb->sv_type) {
|
| 66 |
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case FSTYPE_XENIX:
|
| 67 |
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flc_count = &((struct xenix_freelist_chunk *) bh_data)->fl_nfree;
|
| 68 |
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flc_blocks = &((struct xenix_freelist_chunk *) bh_data)->fl_free[0];
|
| 69 |
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break;
|
| 70 |
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case FSTYPE_SYSV4:
|
| 71 |
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flc_count = &((struct sysv4_freelist_chunk *) bh_data)->fl_nfree;
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| 72 |
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flc_blocks = &((struct sysv4_freelist_chunk *) bh_data)->fl_free[0];
|
| 73 |
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break;
|
| 74 |
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case FSTYPE_SYSV2:
|
| 75 |
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flc_count = &((struct sysv2_freelist_chunk *) bh_data)->fl_nfree;
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| 76 |
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flc_blocks = &((struct sysv2_freelist_chunk *) bh_data)->fl_free[0];
|
| 77 |
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break;
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| 78 |
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case FSTYPE_COH:
|
| 79 |
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flc_count = &((struct coh_freelist_chunk *) bh_data)->fl_nfree;
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| 80 |
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flc_blocks = &((struct coh_freelist_chunk *) bh_data)->fl_free[0];
|
| 81 |
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break;
|
| 82 |
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default: panic("sysv_free_block: invalid fs type\n");
|
| 83 |
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}
|
| 84 |
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*flc_count = *sb->sv_sb_flc_count; /* = sb->sv_flc_size */
|
| 85 |
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memcpy(flc_blocks, sb->sv_sb_flc_blocks, *flc_count * sizeof(sysv_zone_t));
|
| 86 |
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mark_buffer_dirty(bh, 1);
|
| 87 |
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mark_buffer_uptodate(bh, 1);
|
| 88 |
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brelse(bh);
|
| 89 |
|
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*sb->sv_sb_flc_count = 0;
|
| 90 |
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} else
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| 91 |
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/* If the free list head in super-block is empty, create a new head
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| 92 |
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* in this block being freed:
|
| 93 |
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*/
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| 94 |
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if (*sb->sv_sb_flc_count == 0) { /* Applies only to Coherent FS */
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| 95 |
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bh = sv_getblk(sb, sb->s_dev, block);
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| 96 |
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if (!bh) {
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| 97 |
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printk("sysv_free_block: getblk() failed\n");
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| 98 |
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unlock_super(sb);
|
| 99 |
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return;
|
| 100 |
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}
|
| 101 |
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memset(bh->b_data, 0, sb->sv_block_size);
|
| 102 |
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/* this implies ((struct ..._freelist_chunk *) bh->b_data)->flc_count = 0; */
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| 103 |
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mark_buffer_dirty(bh, 1);
|
| 104 |
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mark_buffer_uptodate(bh, 1);
|
| 105 |
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brelse(bh);
|
| 106 |
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/* still *sb->sv_sb_flc_count = 0 */
|
| 107 |
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} else {
|
| 108 |
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/* Throw away block's contents */
|
| 109 |
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bh = sv_get_hash_table(sb, sb->s_dev, block);
|
| 110 |
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if (bh)
|
| 111 |
|
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mark_buffer_clean(bh);
|
| 112 |
|
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brelse(bh);
|
| 113 |
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}
|
| 114 |
|
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if (sb->sv_convert)
|
| 115 |
|
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block = to_coh_ulong(block);
|
| 116 |
|
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sb->sv_sb_flc_blocks[(*sb->sv_sb_flc_count)++] = block;
|
| 117 |
|
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if (sb->sv_convert)
|
| 118 |
|
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*sb->sv_sb_total_free_blocks =
|
| 119 |
|
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to_coh_ulong(from_coh_ulong(*sb->sv_sb_total_free_blocks) + 1);
|
| 120 |
|
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else
|
| 121 |
|
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*sb->sv_sb_total_free_blocks = *sb->sv_sb_total_free_blocks + 1;
|
| 122 |
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mark_buffer_dirty(sb->sv_bh1, 1); /* super-block has been modified */
|
| 123 |
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if (sb->sv_bh1 != sb->sv_bh2) mark_buffer_dirty(sb->sv_bh2, 1);
|
| 124 |
|
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sb->s_dirt = 1; /* and needs time stamp */
|
| 125 |
|
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unlock_super(sb);
|
| 126 |
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}
|
| 127 |
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|
|
| 128 |
|
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int sysv_new_block(struct super_block * sb)
|
| 129 |
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{
|
| 130 |
|
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unsigned int block;
|
| 131 |
|
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struct buffer_head * bh;
|
| 132 |
|
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char * bh_data;
|
| 133 |
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|
|
| 134 |
|
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if (!sb) {
|
| 135 |
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printk("sysv_new_block: trying to get new block from nonexistent device\n");
|
| 136 |
|
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return 0;
|
| 137 |
|
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}
|
| 138 |
|
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lock_super(sb);
|
| 139 |
|
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if (*sb->sv_sb_flc_count == 0) { /* Applies only to Coherent FS */
|
| 140 |
|
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unlock_super(sb);
|
| 141 |
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return 0; /* no blocks available */
|
| 142 |
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}
|
| 143 |
|
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block = sb->sv_sb_flc_blocks[(*sb->sv_sb_flc_count)-1];
|
| 144 |
|
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if (sb->sv_convert)
|
| 145 |
|
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block = from_coh_ulong(block);
|
| 146 |
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if (block == 0) { /* Applies only to Xenix FS, SystemV FS */
|
| 147 |
|
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unlock_super(sb);
|
| 148 |
|
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return 0; /* no blocks available */
|
| 149 |
|
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}
|
| 150 |
|
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(*sb->sv_sb_flc_count)--;
|
| 151 |
|
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if (block < sb->sv_firstdatazone || block >= sb->sv_nzones) {
|
| 152 |
|
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printk("sysv_new_block: new block %d is not in data zone\n",block);
|
| 153 |
|
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unlock_super(sb);
|
| 154 |
|
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return 0;
|
| 155 |
|
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}
|
| 156 |
|
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if (*sb->sv_sb_flc_count == 0) { /* the last block continues the free list */
|
| 157 |
|
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unsigned short * flc_count;
|
| 158 |
|
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unsigned long * flc_blocks;
|
| 159 |
|
|
|
| 160 |
|
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if (!(bh = sv_bread(sb, sb->s_dev, block))) {
|
| 161 |
|
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printk("sysv_new_block: cannot read free-list block\n");
|
| 162 |
|
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/* retry this same block next time */
|
| 163 |
|
|
(*sb->sv_sb_flc_count)++;
|
| 164 |
|
|
unlock_super(sb);
|
| 165 |
|
|
return 0;
|
| 166 |
|
|
}
|
| 167 |
|
|
bh_data = bh->b_data;
|
| 168 |
|
|
switch (sb->sv_type) {
|
| 169 |
|
|
case FSTYPE_XENIX:
|
| 170 |
|
|
flc_count = &((struct xenix_freelist_chunk *) bh_data)->fl_nfree;
|
| 171 |
|
|
flc_blocks = &((struct xenix_freelist_chunk *) bh_data)->fl_free[0];
|
| 172 |
|
|
break;
|
| 173 |
|
|
case FSTYPE_SYSV4:
|
| 174 |
|
|
flc_count = &((struct sysv4_freelist_chunk *) bh_data)->fl_nfree;
|
| 175 |
|
|
flc_blocks = &((struct sysv4_freelist_chunk *) bh_data)->fl_free[0];
|
| 176 |
|
|
break;
|
| 177 |
|
|
case FSTYPE_SYSV2:
|
| 178 |
|
|
flc_count = &((struct sysv2_freelist_chunk *) bh_data)->fl_nfree;
|
| 179 |
|
|
flc_blocks = &((struct sysv2_freelist_chunk *) bh_data)->fl_free[0];
|
| 180 |
|
|
break;
|
| 181 |
|
|
case FSTYPE_COH:
|
| 182 |
|
|
flc_count = &((struct coh_freelist_chunk *) bh_data)->fl_nfree;
|
| 183 |
|
|
flc_blocks = &((struct coh_freelist_chunk *) bh_data)->fl_free[0];
|
| 184 |
|
|
break;
|
| 185 |
|
|
default: panic("sysv_new_block: invalid fs type\n");
|
| 186 |
|
|
}
|
| 187 |
|
|
if (*flc_count > sb->sv_flc_size) {
|
| 188 |
|
|
printk("sysv_new_block: free-list block with >flc_size entries\n");
|
| 189 |
|
|
brelse(bh);
|
| 190 |
|
|
unlock_super(sb);
|
| 191 |
|
|
return 0;
|
| 192 |
|
|
}
|
| 193 |
|
|
*sb->sv_sb_flc_count = *flc_count;
|
| 194 |
|
|
memcpy(sb->sv_sb_flc_blocks, flc_blocks, *flc_count * sizeof(sysv_zone_t));
|
| 195 |
|
|
brelse(bh);
|
| 196 |
|
|
}
|
| 197 |
|
|
/* Now the free list head in the superblock is valid again. */
|
| 198 |
|
|
bh = sv_getblk(sb, sb->s_dev, block);
|
| 199 |
|
|
if (!bh) {
|
| 200 |
|
|
printk("sysv_new_block: getblk() failed\n");
|
| 201 |
|
|
unlock_super(sb);
|
| 202 |
|
|
return 0;
|
| 203 |
|
|
}
|
| 204 |
|
|
if (bh->b_count != 1) {
|
| 205 |
|
|
printk("sysv_new_block: block already in use\n");
|
| 206 |
|
|
unlock_super(sb);
|
| 207 |
|
|
return 0;
|
| 208 |
|
|
}
|
| 209 |
|
|
memset(bh->b_data, 0, sb->sv_block_size);
|
| 210 |
|
|
mark_buffer_dirty(bh, 1);
|
| 211 |
|
|
mark_buffer_uptodate(bh, 1);
|
| 212 |
|
|
brelse(bh);
|
| 213 |
|
|
if (sb->sv_convert)
|
| 214 |
|
|
*sb->sv_sb_total_free_blocks =
|
| 215 |
|
|
to_coh_ulong(from_coh_ulong(*sb->sv_sb_total_free_blocks) - 1);
|
| 216 |
|
|
else
|
| 217 |
|
|
*sb->sv_sb_total_free_blocks = *sb->sv_sb_total_free_blocks - 1;
|
| 218 |
|
|
mark_buffer_dirty(sb->sv_bh1, 1); /* super-block has been modified */
|
| 219 |
|
|
if (sb->sv_bh1 != sb->sv_bh2) mark_buffer_dirty(sb->sv_bh2, 1);
|
| 220 |
|
|
sb->s_dirt = 1; /* and needs time stamp */
|
| 221 |
|
|
unlock_super(sb);
|
| 222 |
|
|
return block;
|
| 223 |
|
|
}
|
| 224 |
|
|
|
| 225 |
|
|
unsigned long sysv_count_free_blocks(struct super_block * sb)
|
| 226 |
|
|
{
|
| 227 |
|
|
#if 1 /* test */
|
| 228 |
|
|
int count, old_count;
|
| 229 |
|
|
unsigned int block;
|
| 230 |
|
|
struct buffer_head * bh;
|
| 231 |
|
|
char * bh_data;
|
| 232 |
|
|
int i;
|
| 233 |
|
|
|
| 234 |
|
|
/* this causes a lot of disk traffic ... */
|
| 235 |
|
|
count = 0;
|
| 236 |
|
|
lock_super(sb);
|
| 237 |
|
|
if (*sb->sv_sb_flc_count > 0) {
|
| 238 |
|
|
for (i = *sb->sv_sb_flc_count ; /* i > 0 */ ; ) {
|
| 239 |
|
|
block = sb->sv_sb_flc_blocks[--i];
|
| 240 |
|
|
if (sb->sv_convert)
|
| 241 |
|
|
block = from_coh_ulong(block);
|
| 242 |
|
|
if (block == 0) /* block 0 terminates list */
|
| 243 |
|
|
goto done;
|
| 244 |
|
|
count++;
|
| 245 |
|
|
if (i == 0)
|
| 246 |
|
|
break;
|
| 247 |
|
|
}
|
| 248 |
|
|
/* block = sb->sv_sb_flc_blocks[0], the last block continues the free list */
|
| 249 |
|
|
while (1) {
|
| 250 |
|
|
unsigned short * flc_count;
|
| 251 |
|
|
unsigned long * flc_blocks;
|
| 252 |
|
|
|
| 253 |
|
|
if (block < sb->sv_firstdatazone || block >= sb->sv_nzones) {
|
| 254 |
|
|
printk("sysv_count_free_blocks: new block %d is not in data zone\n",block);
|
| 255 |
|
|
break;
|
| 256 |
|
|
}
|
| 257 |
|
|
if (!(bh = sv_bread(sb, sb->s_dev, block))) {
|
| 258 |
|
|
printk("sysv_count_free_blocks: cannot read free-list block\n");
|
| 259 |
|
|
break;
|
| 260 |
|
|
}
|
| 261 |
|
|
bh_data = bh->b_data;
|
| 262 |
|
|
switch (sb->sv_type) {
|
| 263 |
|
|
case FSTYPE_XENIX:
|
| 264 |
|
|
flc_count = &((struct xenix_freelist_chunk *) bh_data)->fl_nfree;
|
| 265 |
|
|
flc_blocks = &((struct xenix_freelist_chunk *) bh_data)->fl_free[0];
|
| 266 |
|
|
break;
|
| 267 |
|
|
case FSTYPE_SYSV4:
|
| 268 |
|
|
flc_count = &((struct sysv4_freelist_chunk *) bh_data)->fl_nfree;
|
| 269 |
|
|
flc_blocks = &((struct sysv4_freelist_chunk *) bh_data)->fl_free[0];
|
| 270 |
|
|
break;
|
| 271 |
|
|
case FSTYPE_SYSV2:
|
| 272 |
|
|
flc_count = &((struct sysv2_freelist_chunk *) bh_data)->fl_nfree;
|
| 273 |
|
|
flc_blocks = &((struct sysv2_freelist_chunk *) bh_data)->fl_free[0];
|
| 274 |
|
|
break;
|
| 275 |
|
|
case FSTYPE_COH:
|
| 276 |
|
|
flc_count = &((struct coh_freelist_chunk *) bh_data)->fl_nfree;
|
| 277 |
|
|
flc_blocks = &((struct coh_freelist_chunk *) bh_data)->fl_free[0];
|
| 278 |
|
|
break;
|
| 279 |
|
|
default: panic("sysv_count_free_blocks: invalid fs type\n");
|
| 280 |
|
|
}
|
| 281 |
|
|
if (*flc_count > sb->sv_flc_size) {
|
| 282 |
|
|
printk("sysv_count_free_blocks: free-list block with >flc_size entries\n");
|
| 283 |
|
|
brelse(bh);
|
| 284 |
|
|
break;
|
| 285 |
|
|
}
|
| 286 |
|
|
if (*flc_count == 0) { /* Applies only to Coherent FS */
|
| 287 |
|
|
brelse(bh);
|
| 288 |
|
|
break;
|
| 289 |
|
|
}
|
| 290 |
|
|
for (i = *flc_count ; /* i > 0 */ ; ) {
|
| 291 |
|
|
block = flc_blocks[--i];
|
| 292 |
|
|
if (sb->sv_convert)
|
| 293 |
|
|
block = from_coh_ulong(block);
|
| 294 |
|
|
if (block == 0) /* block 0 terminates list */
|
| 295 |
|
|
break;
|
| 296 |
|
|
count++;
|
| 297 |
|
|
if (i == 0)
|
| 298 |
|
|
break;
|
| 299 |
|
|
}
|
| 300 |
|
|
/* block = flc_blocks[0], the last block continues the free list */
|
| 301 |
|
|
brelse(bh);
|
| 302 |
|
|
if (block == 0) /* Applies only to Xenix FS and SystemV FS */
|
| 303 |
|
|
break;
|
| 304 |
|
|
}
|
| 305 |
|
|
done: ;
|
| 306 |
|
|
}
|
| 307 |
|
|
old_count = *sb->sv_sb_total_free_blocks;
|
| 308 |
|
|
if (sb->sv_convert)
|
| 309 |
|
|
old_count = from_coh_ulong(old_count);
|
| 310 |
|
|
if (count != old_count) {
|
| 311 |
|
|
printk("sysv_count_free_blocks: free block count was %d, correcting to %d\n",old_count,count);
|
| 312 |
|
|
if (!(sb->s_flags & MS_RDONLY)) {
|
| 313 |
|
|
*sb->sv_sb_total_free_blocks = (sb->sv_convert ? to_coh_ulong(count) : count);
|
| 314 |
|
|
mark_buffer_dirty(sb->sv_bh2, 1); /* super-block has been modified */
|
| 315 |
|
|
sb->s_dirt = 1; /* and needs time stamp */
|
| 316 |
|
|
}
|
| 317 |
|
|
}
|
| 318 |
|
|
unlock_super(sb);
|
| 319 |
|
|
return count;
|
| 320 |
|
|
#else
|
| 321 |
|
|
int count;
|
| 322 |
|
|
|
| 323 |
|
|
count = *sb->sv_sb_total_free_blocks;
|
| 324 |
|
|
if (sb->sv_convert)
|
| 325 |
|
|
count = from_coh_ulong(count);
|
| 326 |
|
|
return count;
|
| 327 |
|
|
#endif
|
| 328 |
|
|
}
|
| 329 |
|
|
|
