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1/*
2 * linux/fs/minix/bitmap.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7/*
8 * Modified for 680x0 by Hamish Macdonald
9 * Fixed for 680x0 by Andreas Schwab
10 */
11
12/* bitmap.c contains the code that handles the inode and block bitmaps */
13
14#include "minix.h"
15#include <linux/buffer_head.h>
16#include <linux/bitops.h>
17#include <linux/sched.h>
18
19static DEFINE_SPINLOCK(bitmap_lock);
20
21/*
22 * bitmap consists of blocks filled with 16bit words
23 * bit set == busy, bit clear == free
24 * endianness is a mess, but for counting zero bits it really doesn't matter...
25 */
26static __u32 count_free(struct buffer_head *map[], unsigned blocksize, __u32 numbits)
27{
28 __u32 sum = 0;
29 unsigned blocks = DIV_ROUND_UP(numbits, blocksize * 8);
30
31 while (blocks--) {
32 unsigned words = blocksize / 2;
33 __u16 *p = (__u16 *)(*map++)->b_data;
34 while (words--)
35 sum += 16 - hweight16(*p++);
36 }
37
38 return sum;
39}
40
41void minix_free_block(struct inode *inode, unsigned long block)
42{
43 struct super_block *sb = inode->i_sb;
44 struct minix_sb_info *sbi = minix_sb(sb);
45 struct buffer_head *bh;
46 int k = sb->s_blocksize_bits + 3;
47 unsigned long bit, zone;
48
49 if (block < sbi->s_firstdatazone || block >= sbi->s_nzones) {
50 printk("Trying to free block not in datazone\n");
51 return;
52 }
53 zone = block - sbi->s_firstdatazone + 1;
54 bit = zone & ((1<<k) - 1);
55 zone >>= k;
56 if (zone >= sbi->s_zmap_blocks) {
57 printk("minix_free_block: nonexistent bitmap buffer\n");
58 return;
59 }
60 bh = sbi->s_zmap[zone];
61 spin_lock(&bitmap_lock);
62 if (!minix_test_and_clear_bit(bit, bh->b_data))
63 printk("minix_free_block (%s:%lu): bit already cleared\n",
64 sb->s_id, block);
65 spin_unlock(&bitmap_lock);
66 mark_buffer_dirty(bh);
67 return;
68}
69
70int minix_new_block(struct inode * inode)
71{
72 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
73 int bits_per_zone = 8 * inode->i_sb->s_blocksize;
74 int i;
75
76 for (i = 0; i < sbi->s_zmap_blocks; i++) {
77 struct buffer_head *bh = sbi->s_zmap[i];
78 int j;
79
80 spin_lock(&bitmap_lock);
81 j = minix_find_first_zero_bit(bh->b_data, bits_per_zone);
82 if (j < bits_per_zone) {
83 minix_set_bit(j, bh->b_data);
84 spin_unlock(&bitmap_lock);
85 mark_buffer_dirty(bh);
86 j += i * bits_per_zone + sbi->s_firstdatazone-1;
87 if (j < sbi->s_firstdatazone || j >= sbi->s_nzones)
88 break;
89 return j;
90 }
91 spin_unlock(&bitmap_lock);
92 }
93 return 0;
94}
95
96unsigned long minix_count_free_blocks(struct super_block *sb)
97{
98 struct minix_sb_info *sbi = minix_sb(sb);
99 u32 bits = sbi->s_nzones - (sbi->s_firstdatazone + 1);
100
101 return (count_free(sbi->s_zmap, sb->s_blocksize, bits)
102 << sbi->s_log_zone_size);
103}
104
105struct minix_inode *
106minix_V1_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh)
107{
108 int block;
109 struct minix_sb_info *sbi = minix_sb(sb);
110 struct minix_inode *p;
111
112 if (!ino || ino > sbi->s_ninodes) {
113 printk("Bad inode number on dev %s: %ld is out of range\n",
114 sb->s_id, (long)ino);
115 return NULL;
116 }
117 ino--;
118 block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
119 ino / MINIX_INODES_PER_BLOCK;
120 *bh = sb_bread(sb, block);
121 if (!*bh) {
122 printk("Unable to read inode block\n");
123 return NULL;
124 }
125 p = (void *)(*bh)->b_data;
126 return p + ino % MINIX_INODES_PER_BLOCK;
127}
128
129struct minix2_inode *
130minix_V2_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh)
131{
132 int block;
133 struct minix_sb_info *sbi = minix_sb(sb);
134 struct minix2_inode *p;
135 int minix2_inodes_per_block = sb->s_blocksize / sizeof(struct minix2_inode);
136
137 *bh = NULL;
138 if (!ino || ino > sbi->s_ninodes) {
139 printk("Bad inode number on dev %s: %ld is out of range\n",
140 sb->s_id, (long)ino);
141 return NULL;
142 }
143 ino--;
144 block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
145 ino / minix2_inodes_per_block;
146 *bh = sb_bread(sb, block);
147 if (!*bh) {
148 printk("Unable to read inode block\n");
149 return NULL;
150 }
151 p = (void *)(*bh)->b_data;
152 return p + ino % minix2_inodes_per_block;
153}
154
155/* Clear the link count and mode of a deleted inode on disk. */
156
157static void minix_clear_inode(struct inode *inode)
158{
159 struct buffer_head *bh = NULL;
160
161 if (INODE_VERSION(inode) == MINIX_V1) {
162 struct minix_inode *raw_inode;
163 raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
164 if (raw_inode) {
165 raw_inode->i_nlinks = 0;
166 raw_inode->i_mode = 0;
167 }
168 } else {
169 struct minix2_inode *raw_inode;
170 raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
171 if (raw_inode) {
172 raw_inode->i_nlinks = 0;
173 raw_inode->i_mode = 0;
174 }
175 }
176 if (bh) {
177 mark_buffer_dirty(bh);
178 brelse (bh);
179 }
180}
181
182void minix_free_inode(struct inode * inode)
183{
184 struct super_block *sb = inode->i_sb;
185 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
186 struct buffer_head *bh;
187 int k = sb->s_blocksize_bits + 3;
188 unsigned long ino, bit;
189
190 ino = inode->i_ino;
191 if (ino < 1 || ino > sbi->s_ninodes) {
192 printk("minix_free_inode: inode 0 or nonexistent inode\n");
193 return;
194 }
195 bit = ino & ((1<<k) - 1);
196 ino >>= k;
197 if (ino >= sbi->s_imap_blocks) {
198 printk("minix_free_inode: nonexistent imap in superblock\n");
199 return;
200 }
201
202 minix_clear_inode(inode); /* clear on-disk copy */
203
204 bh = sbi->s_imap[ino];
205 spin_lock(&bitmap_lock);
206 if (!minix_test_and_clear_bit(bit, bh->b_data))
207 printk("minix_free_inode: bit %lu already cleared\n", bit);
208 spin_unlock(&bitmap_lock);
209 mark_buffer_dirty(bh);
210}
211
212struct inode *minix_new_inode(const struct inode *dir, umode_t mode, int *error)
213{
214 struct super_block *sb = dir->i_sb;
215 struct minix_sb_info *sbi = minix_sb(sb);
216 struct inode *inode = new_inode(sb);
217 struct buffer_head * bh;
218 int bits_per_zone = 8 * sb->s_blocksize;
219 unsigned long j;
220 int i;
221
222 if (!inode) {
223 *error = -ENOMEM;
224 return NULL;
225 }
226 j = bits_per_zone;
227 bh = NULL;
228 *error = -ENOSPC;
229 spin_lock(&bitmap_lock);
230 for (i = 0; i < sbi->s_imap_blocks; i++) {
231 bh = sbi->s_imap[i];
232 j = minix_find_first_zero_bit(bh->b_data, bits_per_zone);
233 if (j < bits_per_zone)
234 break;
235 }
236 if (!bh || j >= bits_per_zone) {
237 spin_unlock(&bitmap_lock);
238 iput(inode);
239 return NULL;
240 }
241 if (minix_test_and_set_bit(j, bh->b_data)) { /* shouldn't happen */
242 spin_unlock(&bitmap_lock);
243 printk("minix_new_inode: bit already set\n");
244 iput(inode);
245 return NULL;
246 }
247 spin_unlock(&bitmap_lock);
248 mark_buffer_dirty(bh);
249 j += i * bits_per_zone;
250 if (!j || j > sbi->s_ninodes) {
251 iput(inode);
252 return NULL;
253 }
254 inode_init_owner(inode, dir, mode);
255 inode->i_ino = j;
256 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
257 inode->i_blocks = 0;
258 memset(&minix_i(inode)->u, 0, sizeof(minix_i(inode)->u));
259 insert_inode_hash(inode);
260 mark_inode_dirty(inode);
261
262 *error = 0;
263 return inode;
264}
265
266unsigned long minix_count_free_inodes(struct super_block *sb)
267{
268 struct minix_sb_info *sbi = minix_sb(sb);
269 u32 bits = sbi->s_ninodes + 1;
270
271 return count_free(sbi->s_imap, sb->s_blocksize, bits);
272}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/minix/bitmap.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8/*
9 * Modified for 680x0 by Hamish Macdonald
10 * Fixed for 680x0 by Andreas Schwab
11 */
12
13/* bitmap.c contains the code that handles the inode and block bitmaps */
14
15#include "minix.h"
16#include <linux/buffer_head.h>
17#include <linux/bitops.h>
18#include <linux/sched.h>
19
20static DEFINE_SPINLOCK(bitmap_lock);
21
22/*
23 * bitmap consists of blocks filled with 16bit words
24 * bit set == busy, bit clear == free
25 * endianness is a mess, but for counting zero bits it really doesn't matter...
26 */
27static __u32 count_free(struct buffer_head *map[], unsigned blocksize, __u32 numbits)
28{
29 __u32 sum = 0;
30 unsigned blocks = DIV_ROUND_UP(numbits, blocksize * 8);
31
32 while (blocks--) {
33 unsigned words = blocksize / 2;
34 __u16 *p = (__u16 *)(*map++)->b_data;
35 while (words--)
36 sum += 16 - hweight16(*p++);
37 }
38
39 return sum;
40}
41
42void minix_free_block(struct inode *inode, unsigned long block)
43{
44 struct super_block *sb = inode->i_sb;
45 struct minix_sb_info *sbi = minix_sb(sb);
46 struct buffer_head *bh;
47 int k = sb->s_blocksize_bits + 3;
48 unsigned long bit, zone;
49
50 if (block < sbi->s_firstdatazone || block >= sbi->s_nzones) {
51 printk("Trying to free block not in datazone\n");
52 return;
53 }
54 zone = block - sbi->s_firstdatazone + 1;
55 bit = zone & ((1<<k) - 1);
56 zone >>= k;
57 if (zone >= sbi->s_zmap_blocks) {
58 printk("minix_free_block: nonexistent bitmap buffer\n");
59 return;
60 }
61 bh = sbi->s_zmap[zone];
62 spin_lock(&bitmap_lock);
63 if (!minix_test_and_clear_bit(bit, bh->b_data))
64 printk("minix_free_block (%s:%lu): bit already cleared\n",
65 sb->s_id, block);
66 spin_unlock(&bitmap_lock);
67 mark_buffer_dirty(bh);
68 return;
69}
70
71int minix_new_block(struct inode * inode)
72{
73 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
74 int bits_per_zone = 8 * inode->i_sb->s_blocksize;
75 int i;
76
77 for (i = 0; i < sbi->s_zmap_blocks; i++) {
78 struct buffer_head *bh = sbi->s_zmap[i];
79 int j;
80
81 spin_lock(&bitmap_lock);
82 j = minix_find_first_zero_bit(bh->b_data, bits_per_zone);
83 if (j < bits_per_zone) {
84 minix_set_bit(j, bh->b_data);
85 spin_unlock(&bitmap_lock);
86 mark_buffer_dirty(bh);
87 j += i * bits_per_zone + sbi->s_firstdatazone-1;
88 if (j < sbi->s_firstdatazone || j >= sbi->s_nzones)
89 break;
90 return j;
91 }
92 spin_unlock(&bitmap_lock);
93 }
94 return 0;
95}
96
97unsigned long minix_count_free_blocks(struct super_block *sb)
98{
99 struct minix_sb_info *sbi = minix_sb(sb);
100 u32 bits = sbi->s_nzones - sbi->s_firstdatazone + 1;
101
102 return (count_free(sbi->s_zmap, sb->s_blocksize, bits)
103 << sbi->s_log_zone_size);
104}
105
106struct minix_inode *
107minix_V1_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh)
108{
109 int block;
110 struct minix_sb_info *sbi = minix_sb(sb);
111 struct minix_inode *p;
112
113 if (!ino || ino > sbi->s_ninodes) {
114 printk("Bad inode number on dev %s: %ld is out of range\n",
115 sb->s_id, (long)ino);
116 return NULL;
117 }
118 ino--;
119 block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
120 ino / MINIX_INODES_PER_BLOCK;
121 *bh = sb_bread(sb, block);
122 if (!*bh) {
123 printk("Unable to read inode block\n");
124 return NULL;
125 }
126 p = (void *)(*bh)->b_data;
127 return p + ino % MINIX_INODES_PER_BLOCK;
128}
129
130struct minix2_inode *
131minix_V2_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh)
132{
133 int block;
134 struct minix_sb_info *sbi = minix_sb(sb);
135 struct minix2_inode *p;
136 int minix2_inodes_per_block = sb->s_blocksize / sizeof(struct minix2_inode);
137
138 *bh = NULL;
139 if (!ino || ino > sbi->s_ninodes) {
140 printk("Bad inode number on dev %s: %ld is out of range\n",
141 sb->s_id, (long)ino);
142 return NULL;
143 }
144 ino--;
145 block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
146 ino / minix2_inodes_per_block;
147 *bh = sb_bread(sb, block);
148 if (!*bh) {
149 printk("Unable to read inode block\n");
150 return NULL;
151 }
152 p = (void *)(*bh)->b_data;
153 return p + ino % minix2_inodes_per_block;
154}
155
156/* Clear the link count and mode of a deleted inode on disk. */
157
158static void minix_clear_inode(struct inode *inode)
159{
160 struct buffer_head *bh = NULL;
161
162 if (INODE_VERSION(inode) == MINIX_V1) {
163 struct minix_inode *raw_inode;
164 raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
165 if (raw_inode) {
166 raw_inode->i_nlinks = 0;
167 raw_inode->i_mode = 0;
168 }
169 } else {
170 struct minix2_inode *raw_inode;
171 raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
172 if (raw_inode) {
173 raw_inode->i_nlinks = 0;
174 raw_inode->i_mode = 0;
175 }
176 }
177 if (bh) {
178 mark_buffer_dirty(bh);
179 brelse (bh);
180 }
181}
182
183void minix_free_inode(struct inode * inode)
184{
185 struct super_block *sb = inode->i_sb;
186 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
187 struct buffer_head *bh;
188 int k = sb->s_blocksize_bits + 3;
189 unsigned long ino, bit;
190
191 ino = inode->i_ino;
192 if (ino < 1 || ino > sbi->s_ninodes) {
193 printk("minix_free_inode: inode 0 or nonexistent inode\n");
194 return;
195 }
196 bit = ino & ((1<<k) - 1);
197 ino >>= k;
198 if (ino >= sbi->s_imap_blocks) {
199 printk("minix_free_inode: nonexistent imap in superblock\n");
200 return;
201 }
202
203 minix_clear_inode(inode); /* clear on-disk copy */
204
205 bh = sbi->s_imap[ino];
206 spin_lock(&bitmap_lock);
207 if (!minix_test_and_clear_bit(bit, bh->b_data))
208 printk("minix_free_inode: bit %lu already cleared\n", bit);
209 spin_unlock(&bitmap_lock);
210 mark_buffer_dirty(bh);
211}
212
213struct inode *minix_new_inode(const struct inode *dir, umode_t mode)
214{
215 struct super_block *sb = dir->i_sb;
216 struct minix_sb_info *sbi = minix_sb(sb);
217 struct inode *inode = new_inode(sb);
218 struct buffer_head * bh;
219 int bits_per_zone = 8 * sb->s_blocksize;
220 unsigned long j;
221 int i;
222
223 if (!inode)
224 return ERR_PTR(-ENOMEM);
225 j = bits_per_zone;
226 bh = NULL;
227 spin_lock(&bitmap_lock);
228 for (i = 0; i < sbi->s_imap_blocks; i++) {
229 bh = sbi->s_imap[i];
230 j = minix_find_first_zero_bit(bh->b_data, bits_per_zone);
231 if (j < bits_per_zone)
232 break;
233 }
234 if (!bh || j >= bits_per_zone) {
235 spin_unlock(&bitmap_lock);
236 iput(inode);
237 return ERR_PTR(-ENOSPC);
238 }
239 if (minix_test_and_set_bit(j, bh->b_data)) { /* shouldn't happen */
240 spin_unlock(&bitmap_lock);
241 printk("minix_new_inode: bit already set\n");
242 iput(inode);
243 return ERR_PTR(-ENOSPC);
244 }
245 spin_unlock(&bitmap_lock);
246 mark_buffer_dirty(bh);
247 j += i * bits_per_zone;
248 if (!j || j > sbi->s_ninodes) {
249 iput(inode);
250 return ERR_PTR(-ENOSPC);
251 }
252 inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
253 inode->i_ino = j;
254 simple_inode_init_ts(inode);
255 inode->i_blocks = 0;
256 memset(&minix_i(inode)->u, 0, sizeof(minix_i(inode)->u));
257 insert_inode_hash(inode);
258 mark_inode_dirty(inode);
259
260 return inode;
261}
262
263unsigned long minix_count_free_inodes(struct super_block *sb)
264{
265 struct minix_sb_info *sbi = minix_sb(sb);
266 u32 bits = sbi->s_ninodes + 1;
267
268 return count_free(sbi->s_imap, sb->s_blocksize, bits);
269}