diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/qnx4/bitmap.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/qnx4/bitmap.c')
-rw-r--r-- | fs/qnx4/bitmap.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/fs/qnx4/bitmap.c b/fs/qnx4/bitmap.c new file mode 100644 index 000000000000..991253927658 --- /dev/null +++ b/fs/qnx4/bitmap.c | |||
@@ -0,0 +1,165 @@ | |||
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/time.h> | ||
18 | #include <linux/fs.h> | ||
19 | #include <linux/qnx4_fs.h> | ||
20 | #include <linux/stat.h> | ||
21 | #include <linux/kernel.h> | ||
22 | #include <linux/string.h> | ||
23 | #include <linux/buffer_head.h> | ||
24 | #include <linux/bitops.h> | ||
25 | |||
26 | int qnx4_new_block(struct super_block *sb) | ||
27 | { | ||
28 | return 0; | ||
29 | } | ||
30 | |||
31 | static void count_bits(register const char *bmPart, register int size, | ||
32 | int *const tf) | ||
33 | { | ||
34 | char b; | ||
35 | int tot = *tf; | ||
36 | |||
37 | if (size > QNX4_BLOCK_SIZE) { | ||
38 | size = QNX4_BLOCK_SIZE; | ||
39 | } | ||
40 | do { | ||
41 | b = *bmPart++; | ||
42 | if ((b & 1) == 0) | ||
43 | tot++; | ||
44 | if ((b & 2) == 0) | ||
45 | tot++; | ||
46 | if ((b & 4) == 0) | ||
47 | tot++; | ||
48 | if ((b & 8) == 0) | ||
49 | tot++; | ||
50 | if ((b & 16) == 0) | ||
51 | tot++; | ||
52 | if ((b & 32) == 0) | ||
53 | tot++; | ||
54 | if ((b & 64) == 0) | ||
55 | tot++; | ||
56 | if ((b & 128) == 0) | ||
57 | tot++; | ||
58 | size--; | ||
59 | } while (size != 0); | ||
60 | *tf = tot; | ||
61 | } | ||
62 | |||
63 | unsigned long qnx4_count_free_blocks(struct super_block *sb) | ||
64 | { | ||
65 | int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; | ||
66 | int total = 0; | ||
67 | int total_free = 0; | ||
68 | int offset = 0; | ||
69 | int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); | ||
70 | struct buffer_head *bh; | ||
71 | |||
72 | while (total < size) { | ||
73 | if ((bh = sb_bread(sb, start + offset)) == NULL) { | ||
74 | printk("qnx4: I/O error in counting free blocks\n"); | ||
75 | break; | ||
76 | } | ||
77 | count_bits(bh->b_data, size - total, &total_free); | ||
78 | brelse(bh); | ||
79 | total += QNX4_BLOCK_SIZE; | ||
80 | offset++; | ||
81 | } | ||
82 | |||
83 | return total_free; | ||
84 | } | ||
85 | |||
86 | #ifdef CONFIG_QNX4FS_RW | ||
87 | |||
88 | int qnx4_is_free(struct super_block *sb, long block) | ||
89 | { | ||
90 | int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; | ||
91 | int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); | ||
92 | struct buffer_head *bh; | ||
93 | const char *g; | ||
94 | int ret = -EIO; | ||
95 | |||
96 | start += block / (QNX4_BLOCK_SIZE * 8); | ||
97 | QNX4DEBUG(("qnx4: is_free requesting block [%lu], bitmap in block [%lu]\n", | ||
98 | (unsigned long) block, (unsigned long) start)); | ||
99 | (void) size; /* CHECKME */ | ||
100 | bh = sb_bread(sb, start); | ||
101 | if (bh == NULL) { | ||
102 | return -EIO; | ||
103 | } | ||
104 | g = bh->b_data + (block % QNX4_BLOCK_SIZE); | ||
105 | if (((*g) & (1 << (block % 8))) == 0) { | ||
106 | QNX4DEBUG(("qnx4: is_free -> block is free\n")); | ||
107 | ret = 1; | ||
108 | } else { | ||
109 | QNX4DEBUG(("qnx4: is_free -> block is busy\n")); | ||
110 | ret = 0; | ||
111 | } | ||
112 | brelse(bh); | ||
113 | |||
114 | return ret; | ||
115 | } | ||
116 | |||
117 | int qnx4_set_bitmap(struct super_block *sb, long block, int busy) | ||
118 | { | ||
119 | int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; | ||
120 | int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); | ||
121 | struct buffer_head *bh; | ||
122 | char *g; | ||
123 | |||
124 | start += block / (QNX4_BLOCK_SIZE * 8); | ||
125 | QNX4DEBUG(("qnx4: set_bitmap requesting block [%lu], bitmap in block [%lu]\n", | ||
126 | (unsigned long) block, (unsigned long) start)); | ||
127 | (void) size; /* CHECKME */ | ||
128 | bh = sb_bread(sb, start); | ||
129 | if (bh == NULL) { | ||
130 | return -EIO; | ||
131 | } | ||
132 | g = bh->b_data + (block % QNX4_BLOCK_SIZE); | ||
133 | if (busy == 0) { | ||
134 | (*g) &= ~(1 << (block % 8)); | ||
135 | } else { | ||
136 | (*g) |= (1 << (block % 8)); | ||
137 | } | ||
138 | mark_buffer_dirty(bh); | ||
139 | brelse(bh); | ||
140 | |||
141 | return 0; | ||
142 | } | ||
143 | |||
144 | static void qnx4_clear_inode(struct inode *inode) | ||
145 | { | ||
146 | struct qnx4_inode_entry *qnx4_ino = qnx4_raw_inode(inode); | ||
147 | /* What for? */ | ||
148 | memset(qnx4_ino->di_fname, 0, sizeof qnx4_ino->di_fname); | ||
149 | qnx4_ino->di_size = 0; | ||
150 | qnx4_ino->di_num_xtnts = 0; | ||
151 | qnx4_ino->di_mode = 0; | ||
152 | qnx4_ino->di_status = 0; | ||
153 | } | ||
154 | |||
155 | void qnx4_free_inode(struct inode *inode) | ||
156 | { | ||
157 | if (inode->i_ino < 1) { | ||
158 | printk("free_inode: inode 0 or nonexistent inode\n"); | ||
159 | return; | ||
160 | } | ||
161 | qnx4_clear_inode(inode); | ||
162 | clear_inode(inode); | ||
163 | } | ||
164 | |||
165 | #endif | ||