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
16 #include <linux/config.h>
17 #include <linux/sched.h>
18 #include <linux/qnx4_fs.h>
19 #include <linux/stat.h>
20 #include <linux/kernel.h>
21 #include <linux/string.h>
22
23 #include <asm/bitops.h>
24
qnx4_new_block(struct super_block * sb)25 int qnx4_new_block(struct super_block *sb)
26 {
27 return 0;
28 }
29
count_bits(const register char * bmPart,register int size,int * const tf)30 void count_bits(const register char *bmPart, register int size,
31 int *const tf)
32 {
33 char b;
34 int tot = *tf;
35
36 if (size > QNX4_BLOCK_SIZE) {
37 size = QNX4_BLOCK_SIZE;
38 }
39 do {
40 b = *bmPart++;
41 if ((b & 1) == 0)
42 tot++;
43 if ((b & 2) == 0)
44 tot++;
45 if ((b & 4) == 0)
46 tot++;
47 if ((b & 8) == 0)
48 tot++;
49 if ((b & 16) == 0)
50 tot++;
51 if ((b & 32) == 0)
52 tot++;
53 if ((b & 64) == 0)
54 tot++;
55 if ((b & 128) == 0)
56 tot++;
57 size--;
58 } while (size != 0);
59 *tf = tot;
60 }
61
qnx4_count_free_blocks(struct super_block * sb)62 unsigned long qnx4_count_free_blocks(struct super_block *sb)
63 {
64 int start = le32_to_cpu(sb->u.qnx4_sb.BitMap->di_first_xtnt.xtnt_blk) - 1;
65 int total = 0;
66 int total_free = 0;
67 int offset = 0;
68 int size = le32_to_cpu(sb->u.qnx4_sb.BitMap->di_size);
69 struct buffer_head *bh;
70
71 while (total < size) {
72 if ((bh = sb_bread(sb, start + offset)) == NULL) {
73 printk("qnx4: I/O error in counting free blocks\n");
74 break;
75 }
76 count_bits(bh->b_data, size - total, &total_free);
77 brelse(bh);
78 total += QNX4_BLOCK_SIZE;
79 offset++;
80 }
81
82 return total_free;
83 }
84
85 #ifdef CONFIG_QNX4FS_RW
86
qnx4_is_free(struct super_block * sb,long block)87 int qnx4_is_free(struct super_block *sb, long block)
88 {
89 int start = le32_to_cpu(sb->u.qnx4_sb.BitMap->di_first_xtnt.xtnt_blk) - 1;
90 int size = le32_to_cpu(sb->u.qnx4_sb.BitMap->di_size);
91 struct buffer_head *bh;
92 const char *g;
93 int ret = -EIO;
94
95 start += block / (QNX4_BLOCK_SIZE * 8);
96 QNX4DEBUG(("qnx4: is_free requesting block [%lu], bitmap in block [%lu]\n",
97 (unsigned long) block, (unsigned long) start));
98 (void) size; /* CHECKME */
99 bh = sb_bread(sb, start);
100 if (bh == NULL) {
101 return -EIO;
102 }
103 g = bh->b_data + (block % QNX4_BLOCK_SIZE);
104 if (((*g) & (1 << (block % 8))) == 0) {
105 QNX4DEBUG(("qnx4: is_free -> block is free\n"));
106 ret = 1;
107 } else {
108 QNX4DEBUG(("qnx4: is_free -> block is busy\n"));
109 ret = 0;
110 }
111 brelse(bh);
112
113 return ret;
114 }
115
qnx4_set_bitmap(struct super_block * sb,long block,int busy)116 int qnx4_set_bitmap(struct super_block *sb, long block, int busy)
117 {
118 int start = le32_to_cpu(sb->u.qnx4_sb.BitMap->di_first_xtnt.xtnt_blk) - 1;
119 int size = le32_to_cpu(sb->u.qnx4_sb.BitMap->di_size);
120 struct buffer_head *bh;
121 char *g;
122
123 start += block / (QNX4_BLOCK_SIZE * 8);
124 QNX4DEBUG(("qnx4: set_bitmap requesting block [%lu], bitmap in block [%lu]\n",
125 (unsigned long) block, (unsigned long) start));
126 (void) size; /* CHECKME */
127 bh = sb_bread(sb, start);
128 if (bh == NULL) {
129 return -EIO;
130 }
131 g = bh->b_data + (block % QNX4_BLOCK_SIZE);
132 if (busy == 0) {
133 (*g) &= ~(1 << (block % 8));
134 } else {
135 (*g) |= (1 << (block % 8));
136 }
137 mark_buffer_dirty(bh);
138 brelse(bh);
139
140 return 0;
141 }
142
qnx4_clear_inode(struct inode * inode)143 static void qnx4_clear_inode(struct inode *inode)
144 {
145 struct qnx4_inode_info *qnx4_ino = &inode->u.qnx4_i;
146
147 memset(qnx4_ino->i_reserved, 0, sizeof qnx4_ino->i_reserved);
148 qnx4_ino->i_size = 0;
149 qnx4_ino->i_num_xtnts = 0;
150 qnx4_ino->i_mode = 0;
151 qnx4_ino->i_status = 0;
152 }
153
qnx4_free_inode(struct inode * inode)154 void qnx4_free_inode(struct inode *inode)
155 {
156 if (inode->i_ino < 1) {
157 printk("free_inode: inode 0 or nonexistent inode\n");
158 return;
159 }
160 qnx4_clear_inode(inode);
161 clear_inode(inode);
162 }
163
164 #endif
165