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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 const int nibblemap[] = { 4,3,3,2,3,2,2,1,3,2,2,1,2,1,1,0 };
20
21static DEFINE_SPINLOCK(bitmap_lock);
22
23static unsigned long count_free(struct buffer_head *map[], unsigned numblocks, __u32 numbits)
24{
25 unsigned i, j, sum = 0;
26 struct buffer_head *bh;
27
28 for (i=0; i<numblocks-1; i++) {
29 if (!(bh=map[i]))
30 return(0);
31 for (j=0; j<bh->b_size; j++)
32 sum += nibblemap[bh->b_data[j] & 0xf]
33 + nibblemap[(bh->b_data[j]>>4) & 0xf];
34 }
35
36 if (numblocks==0 || !(bh=map[numblocks-1]))
37 return(0);
38 i = ((numbits - (numblocks-1) * bh->b_size * 8) / 16) * 2;
39 for (j=0; j<i; j++) {
40 sum += nibblemap[bh->b_data[j] & 0xf]
41 + nibblemap[(bh->b_data[j]>>4) & 0xf];
42 }
43
44 i = numbits%16;
45 if (i!=0) {
46 i = *(__u16 *)(&bh->b_data[j]) | ~((1<<i) - 1);
47 sum += nibblemap[i & 0xf] + nibblemap[(i>>4) & 0xf];
48 sum += nibblemap[(i>>8) & 0xf] + nibblemap[(i>>12) & 0xf];
49 }
50 return(sum);
51}
52
53void minix_free_block(struct inode *inode, unsigned long block)
54{
55 struct super_block *sb = inode->i_sb;
56 struct minix_sb_info *sbi = minix_sb(sb);
57 struct buffer_head *bh;
58 int k = sb->s_blocksize_bits + 3;
59 unsigned long bit, zone;
60
61 if (block < sbi->s_firstdatazone || block >= sbi->s_nzones) {
62 printk("Trying to free block not in datazone\n");
63 return;
64 }
65 zone = block - sbi->s_firstdatazone + 1;
66 bit = zone & ((1<<k) - 1);
67 zone >>= k;
68 if (zone >= sbi->s_zmap_blocks) {
69 printk("minix_free_block: nonexistent bitmap buffer\n");
70 return;
71 }
72 bh = sbi->s_zmap[zone];
73 spin_lock(&bitmap_lock);
74 if (!minix_test_and_clear_bit(bit, bh->b_data))
75 printk("minix_free_block (%s:%lu): bit already cleared\n",
76 sb->s_id, block);
77 spin_unlock(&bitmap_lock);
78 mark_buffer_dirty(bh);
79 return;
80}
81
82int minix_new_block(struct inode * inode)
83{
84 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
85 int bits_per_zone = 8 * inode->i_sb->s_blocksize;
86 int i;
87
88 for (i = 0; i < sbi->s_zmap_blocks; i++) {
89 struct buffer_head *bh = sbi->s_zmap[i];
90 int j;
91
92 spin_lock(&bitmap_lock);
93 j = minix_find_first_zero_bit(bh->b_data, bits_per_zone);
94 if (j < bits_per_zone) {
95 minix_set_bit(j, bh->b_data);
96 spin_unlock(&bitmap_lock);
97 mark_buffer_dirty(bh);
98 j += i * bits_per_zone + sbi->s_firstdatazone-1;
99 if (j < sbi->s_firstdatazone || j >= sbi->s_nzones)
100 break;
101 return j;
102 }
103 spin_unlock(&bitmap_lock);
104 }
105 return 0;
106}
107
108unsigned long minix_count_free_blocks(struct minix_sb_info *sbi)
109{
110 return (count_free(sbi->s_zmap, sbi->s_zmap_blocks,
111 sbi->s_nzones - sbi->s_firstdatazone + 1)
112 << sbi->s_log_zone_size);
113}
114
115struct minix_inode *
116minix_V1_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh)
117{
118 int block;
119 struct minix_sb_info *sbi = minix_sb(sb);
120 struct minix_inode *p;
121
122 if (!ino || ino > sbi->s_ninodes) {
123 printk("Bad inode number on dev %s: %ld is out of range\n",
124 sb->s_id, (long)ino);
125 return NULL;
126 }
127 ino--;
128 block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
129 ino / MINIX_INODES_PER_BLOCK;
130 *bh = sb_bread(sb, block);
131 if (!*bh) {
132 printk("Unable to read inode block\n");
133 return NULL;
134 }
135 p = (void *)(*bh)->b_data;
136 return p + ino % MINIX_INODES_PER_BLOCK;
137}
138
139struct minix2_inode *
140minix_V2_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh)
141{
142 int block;
143 struct minix_sb_info *sbi = minix_sb(sb);
144 struct minix2_inode *p;
145 int minix2_inodes_per_block = sb->s_blocksize / sizeof(struct minix2_inode);
146
147 *bh = NULL;
148 if (!ino || ino > sbi->s_ninodes) {
149 printk("Bad inode number on dev %s: %ld is out of range\n",
150 sb->s_id, (long)ino);
151 return NULL;
152 }
153 ino--;
154 block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
155 ino / minix2_inodes_per_block;
156 *bh = sb_bread(sb, block);
157 if (!*bh) {
158 printk("Unable to read inode block\n");
159 return NULL;
160 }
161 p = (void *)(*bh)->b_data;
162 return p + ino % minix2_inodes_per_block;
163}
164
165/* Clear the link count and mode of a deleted inode on disk. */
166
167static void minix_clear_inode(struct inode *inode)
168{
169 struct buffer_head *bh = NULL;
170
171 if (INODE_VERSION(inode) == MINIX_V1) {
172 struct minix_inode *raw_inode;
173 raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
174 if (raw_inode) {
175 raw_inode->i_nlinks = 0;
176 raw_inode->i_mode = 0;
177 }
178 } else {
179 struct minix2_inode *raw_inode;
180 raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
181 if (raw_inode) {
182 raw_inode->i_nlinks = 0;
183 raw_inode->i_mode = 0;
184 }
185 }
186 if (bh) {
187 mark_buffer_dirty(bh);
188 brelse (bh);
189 }
190}
191
192void minix_free_inode(struct inode * inode)
193{
194 struct super_block *sb = inode->i_sb;
195 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
196 struct buffer_head *bh;
197 int k = sb->s_blocksize_bits + 3;
198 unsigned long ino, bit;
199
200 ino = inode->i_ino;
201 if (ino < 1 || ino > sbi->s_ninodes) {
202 printk("minix_free_inode: inode 0 or nonexistent inode\n");
203 return;
204 }
205 bit = ino & ((1<<k) - 1);
206 ino >>= k;
207 if (ino >= sbi->s_imap_blocks) {
208 printk("minix_free_inode: nonexistent imap in superblock\n");
209 return;
210 }
211
212 minix_clear_inode(inode); /* clear on-disk copy */
213
214 bh = sbi->s_imap[ino];
215 spin_lock(&bitmap_lock);
216 if (!minix_test_and_clear_bit(bit, bh->b_data))
217 printk("minix_free_inode: bit %lu already cleared\n", bit);
218 spin_unlock(&bitmap_lock);
219 mark_buffer_dirty(bh);
220}
221
222struct inode *minix_new_inode(const struct inode *dir, int mode, int *error)
223{
224 struct super_block *sb = dir->i_sb;
225 struct minix_sb_info *sbi = minix_sb(sb);
226 struct inode *inode = new_inode(sb);
227 struct buffer_head * bh;
228 int bits_per_zone = 8 * sb->s_blocksize;
229 unsigned long j;
230 int i;
231
232 if (!inode) {
233 *error = -ENOMEM;
234 return NULL;
235 }
236 j = bits_per_zone;
237 bh = NULL;
238 *error = -ENOSPC;
239 spin_lock(&bitmap_lock);
240 for (i = 0; i < sbi->s_imap_blocks; i++) {
241 bh = sbi->s_imap[i];
242 j = minix_find_first_zero_bit(bh->b_data, bits_per_zone);
243 if (j < bits_per_zone)
244 break;
245 }
246 if (!bh || j >= bits_per_zone) {
247 spin_unlock(&bitmap_lock);
248 iput(inode);
249 return NULL;
250 }
251 if (minix_test_and_set_bit(j, bh->b_data)) { /* shouldn't happen */
252 spin_unlock(&bitmap_lock);
253 printk("minix_new_inode: bit already set\n");
254 iput(inode);
255 return NULL;
256 }
257 spin_unlock(&bitmap_lock);
258 mark_buffer_dirty(bh);
259 j += i * bits_per_zone;
260 if (!j || j > sbi->s_ninodes) {
261 iput(inode);
262 return NULL;
263 }
264 inode_init_owner(inode, dir, mode);
265 inode->i_ino = j;
266 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
267 inode->i_blocks = 0;
268 memset(&minix_i(inode)->u, 0, sizeof(minix_i(inode)->u));
269 insert_inode_hash(inode);
270 mark_inode_dirty(inode);
271
272 *error = 0;
273 return inode;
274}
275
276unsigned long minix_count_free_inodes(struct minix_sb_info *sbi)
277{
278 return count_free(sbi->s_imap, sbi->s_imap_blocks, sbi->s_ninodes + 1);
279}
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}