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1da177e4 LT |
1 | /* |
2 | * QNX4 file system, Linux implementation. | |
3 | * | |
4 | * Version : 0.2.1 | |
5 | * | |
6 | * Using parts of the xiafs filesystem. | |
7 | * | |
8 | * History : | |
9 | * | |
10 | * 28-05-1998 by Richard Frowijn : first release. | |
11 | * 20-06-1998 by Frank Denis : basic optimisations. | |
12 | * 25-06-1998 by Frank Denis : qnx4_is_free, qnx4_set_bitmap, qnx4_bmap . | |
13 | * 28-06-1998 by Frank Denis : qnx4_free_inode (to be fixed) . | |
14 | */ | |
15 | ||
1da177e4 LT |
16 | #include <linux/buffer_head.h> |
17 | #include <linux/bitops.h> | |
964f5369 | 18 | #include "qnx4.h" |
1da177e4 | 19 | |
7a1119b1 | 20 | #if 0 |
1da177e4 LT |
21 | int qnx4_new_block(struct super_block *sb) |
22 | { | |
23 | return 0; | |
24 | } | |
7a1119b1 | 25 | #endif /* 0 */ |
1da177e4 LT |
26 | |
27 | static void count_bits(register const char *bmPart, register int size, | |
28 | int *const tf) | |
29 | { | |
30 | char b; | |
31 | int tot = *tf; | |
32 | ||
33 | if (size > QNX4_BLOCK_SIZE) { | |
34 | size = QNX4_BLOCK_SIZE; | |
35 | } | |
36 | do { | |
37 | b = *bmPart++; | |
38 | if ((b & 1) == 0) | |
39 | tot++; | |
40 | if ((b & 2) == 0) | |
41 | tot++; | |
42 | if ((b & 4) == 0) | |
43 | tot++; | |
44 | if ((b & 8) == 0) | |
45 | tot++; | |
46 | if ((b & 16) == 0) | |
47 | tot++; | |
48 | if ((b & 32) == 0) | |
49 | tot++; | |
50 | if ((b & 64) == 0) | |
51 | tot++; | |
52 | if ((b & 128) == 0) | |
53 | tot++; | |
54 | size--; | |
55 | } while (size != 0); | |
56 | *tf = tot; | |
57 | } | |
58 | ||
59 | unsigned long qnx4_count_free_blocks(struct super_block *sb) | |
60 | { | |
61 | int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; | |
62 | int total = 0; | |
63 | int total_free = 0; | |
64 | int offset = 0; | |
65 | int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); | |
66 | struct buffer_head *bh; | |
67 | ||
68 | while (total < size) { | |
69 | if ((bh = sb_bread(sb, start + offset)) == NULL) { | |
70 | printk("qnx4: I/O error in counting free blocks\n"); | |
71 | break; | |
72 | } | |
73 | count_bits(bh->b_data, size - total, &total_free); | |
74 | brelse(bh); | |
75 | total += QNX4_BLOCK_SIZE; | |
76 | offset++; | |
77 | } | |
78 | ||
79 | return total_free; | |
80 | } | |
81 | ||
82 | #ifdef CONFIG_QNX4FS_RW | |
83 | ||
84 | int qnx4_is_free(struct super_block *sb, long block) | |
85 | { | |
86 | int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; | |
87 | int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); | |
88 | struct buffer_head *bh; | |
89 | const char *g; | |
90 | int ret = -EIO; | |
91 | ||
92 | start += block / (QNX4_BLOCK_SIZE * 8); | |
93 | QNX4DEBUG(("qnx4: is_free requesting block [%lu], bitmap in block [%lu]\n", | |
94 | (unsigned long) block, (unsigned long) start)); | |
95 | (void) size; /* CHECKME */ | |
96 | bh = sb_bread(sb, start); | |
97 | if (bh == NULL) { | |
98 | return -EIO; | |
99 | } | |
100 | g = bh->b_data + (block % QNX4_BLOCK_SIZE); | |
101 | if (((*g) & (1 << (block % 8))) == 0) { | |
102 | QNX4DEBUG(("qnx4: is_free -> block is free\n")); | |
103 | ret = 1; | |
104 | } else { | |
105 | QNX4DEBUG(("qnx4: is_free -> block is busy\n")); | |
106 | ret = 0; | |
107 | } | |
108 | brelse(bh); | |
109 | ||
110 | return ret; | |
111 | } | |
112 | ||
113 | int qnx4_set_bitmap(struct super_block *sb, long block, int busy) | |
114 | { | |
115 | int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; | |
116 | int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); | |
117 | struct buffer_head *bh; | |
118 | char *g; | |
119 | ||
120 | start += block / (QNX4_BLOCK_SIZE * 8); | |
121 | QNX4DEBUG(("qnx4: set_bitmap requesting block [%lu], bitmap in block [%lu]\n", | |
122 | (unsigned long) block, (unsigned long) start)); | |
123 | (void) size; /* CHECKME */ | |
124 | bh = sb_bread(sb, start); | |
125 | if (bh == NULL) { | |
126 | return -EIO; | |
127 | } | |
128 | g = bh->b_data + (block % QNX4_BLOCK_SIZE); | |
129 | if (busy == 0) { | |
130 | (*g) &= ~(1 << (block % 8)); | |
131 | } else { | |
132 | (*g) |= (1 << (block % 8)); | |
133 | } | |
134 | mark_buffer_dirty(bh); | |
135 | brelse(bh); | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
140 | static void qnx4_clear_inode(struct inode *inode) | |
141 | { | |
142 | struct qnx4_inode_entry *qnx4_ino = qnx4_raw_inode(inode); | |
143 | /* What for? */ | |
144 | memset(qnx4_ino->di_fname, 0, sizeof qnx4_ino->di_fname); | |
145 | qnx4_ino->di_size = 0; | |
146 | qnx4_ino->di_num_xtnts = 0; | |
147 | qnx4_ino->di_mode = 0; | |
148 | qnx4_ino->di_status = 0; | |
149 | } | |
150 | ||
151 | void qnx4_free_inode(struct inode *inode) | |
152 | { | |
153 | if (inode->i_ino < 1) { | |
154 | printk("free_inode: inode 0 or nonexistent inode\n"); | |
155 | return; | |
156 | } | |
157 | qnx4_clear_inode(inode); | |
158 | clear_inode(inode); | |
159 | } | |
160 | ||
161 | #endif |