1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/ufs/cylinder.c
4 *
5 * Copyright (C) 1998
6 * Daniel Pirkl <daniel.pirkl@email.cz>
7 * Charles University, Faculty of Mathematics and Physics
8 *
9 * ext2 - inode (block) bitmap caching inspired
10 */
11
12 #include <linux/fs.h>
13 #include <linux/time.h>
14 #include <linux/stat.h>
15 #include <linux/string.h>
16 #include <linux/bitops.h>
17
18 #include <asm/byteorder.h>
19
20 #include "ufs_fs.h"
21 #include "ufs.h"
22 #include "swab.h"
23 #include "util.h"
24
25 /*
26 * Read cylinder group into cache. The memory space for ufs_cg_private_info
27 * structure is already allocated during ufs_read_super.
28 */
29 static void ufs_read_cylinder (struct super_block * sb,
30 unsigned cgno, unsigned bitmap_nr)
31 {
32 struct ufs_sb_info * sbi = UFS_SB(sb);
33 struct ufs_sb_private_info * uspi;
34 struct ufs_cg_private_info * ucpi;
35 struct ufs_cylinder_group * ucg;
36 unsigned i, j;
37
38 UFSD("ENTER, cgno %u, bitmap_nr %u\n", cgno, bitmap_nr);
39 uspi = sbi->s_uspi;
40 ucpi = sbi->s_ucpi[bitmap_nr];
41 ucg = (struct ufs_cylinder_group *)sbi->s_ucg[cgno]->b_data;
42
43 UCPI_UBH(ucpi)->fragment = ufs_cgcmin(cgno);
44 UCPI_UBH(ucpi)->count = uspi->s_cgsize >> sb->s_blocksize_bits;
45 /*
46 * We have already the first fragment of cylinder group block in buffer
47 */
48 UCPI_UBH(ucpi)->bh[0] = sbi->s_ucg[cgno];
49 for (i = 1; i < UCPI_UBH(ucpi)->count; i++)
50 if (!(UCPI_UBH(ucpi)->bh[i] = sb_bread(sb, UCPI_UBH(ucpi)->fragment + i)))
51 goto failed;
52 sbi->s_cgno[bitmap_nr] = cgno;
53
54 ucpi->c_cgx = fs32_to_cpu(sb, ucg->cg_cgx);
55 ucpi->c_ncyl = fs16_to_cpu(sb, ucg->cg_ncyl);
56 ucpi->c_niblk = fs16_to_cpu(sb, ucg->cg_niblk);
57 ucpi->c_ndblk = fs32_to_cpu(sb, ucg->cg_ndblk);
58 ucpi->c_rotor = fs32_to_cpu(sb, ucg->cg_rotor);
59 ucpi->c_frotor = fs32_to_cpu(sb, ucg->cg_frotor);
60 ucpi->c_irotor = fs32_to_cpu(sb, ucg->cg_irotor);
61 ucpi->c_btotoff = fs32_to_cpu(sb, ucg->cg_btotoff);
62 ucpi->c_boff = fs32_to_cpu(sb, ucg->cg_boff);
63 ucpi->c_iusedoff = fs32_to_cpu(sb, ucg->cg_iusedoff);
64 ucpi->c_freeoff = fs32_to_cpu(sb, ucg->cg_freeoff);
65 ucpi->c_nextfreeoff = fs32_to_cpu(sb, ucg->cg_nextfreeoff);
66 ucpi->c_clustersumoff = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_clustersumoff);
67 ucpi->c_clusteroff = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_clusteroff);
68 ucpi->c_nclusterblks = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_nclusterblks);
69 UFSD("EXIT\n");
70 return;
71
72 failed:
73 for (j = 1; j < i; j++)
74 brelse (sbi->s_ucg[j]);
75 sbi->s_cgno[bitmap_nr] = UFS_CGNO_EMPTY;
76 ufs_error (sb, "ufs_read_cylinder", "can't read cylinder group block %u", cgno);
77 }
78
79 /*
80 * Remove cylinder group from cache, doesn't release memory
81 * allocated for cylinder group (this is done at ufs_put_super only).
82 */
83 void ufs_put_cylinder (struct super_block * sb, unsigned bitmap_nr)
84 {
85 struct ufs_sb_info * sbi = UFS_SB(sb);
86 struct ufs_sb_private_info * uspi;
87 struct ufs_cg_private_info * ucpi;
88 struct ufs_cylinder_group * ucg;
89 unsigned i;
90
91 UFSD("ENTER, bitmap_nr %u\n", bitmap_nr);
92
93 uspi = sbi->s_uspi;
94 if (sbi->s_cgno[bitmap_nr] == UFS_CGNO_EMPTY) {
95 UFSD("EXIT\n");
96 return;
97 }
98 ucpi = sbi->s_ucpi[bitmap_nr];
99 ucg = ubh_get_ucg(UCPI_UBH(ucpi));
100
101 if (uspi->s_ncg > UFS_MAX_GROUP_LOADED && bitmap_nr >= sbi->s_cg_loaded) {
102 ufs_panic (sb, "ufs_put_cylinder", "internal error");
103 return;
104 }
105 /*
106 * rotor is not so important data, so we put it to disk
107 * at the end of working with cylinder
108 */
109 ucg->cg_rotor = cpu_to_fs32(sb, ucpi->c_rotor);
110 ucg->cg_frotor = cpu_to_fs32(sb, ucpi->c_frotor);
111 ucg->cg_irotor = cpu_to_fs32(sb, ucpi->c_irotor);
112 ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
113 for (i = 1; i < UCPI_UBH(ucpi)->count; i++) {
114 brelse (UCPI_UBH(ucpi)->bh[i]);
115 }
116
117 sbi->s_cgno[bitmap_nr] = UFS_CGNO_EMPTY;
118 UFSD("EXIT\n");
119 }
120
121 /*
122 * Find cylinder group in cache and return it as pointer.
123 * If cylinder group is not in cache, we will load it from disk.
124 *
125 * The cache is managed by LRU algorithm.
126 */
127 struct ufs_cg_private_info * ufs_load_cylinder (
128 struct super_block * sb, unsigned cgno)
129 {
130 struct ufs_sb_info * sbi = UFS_SB(sb);
131 struct ufs_sb_private_info * uspi;
132 struct ufs_cg_private_info * ucpi;
133 unsigned cg, i, j;
134
135 UFSD("ENTER, cgno %u\n", cgno);
136
137 uspi = sbi->s_uspi;
138 if (cgno >= uspi->s_ncg) {
139 ufs_panic (sb, "ufs_load_cylinder", "internal error, high number of cg");
140 return NULL;
141 }
142 /*
143 * Cylinder group number cg it in cache and it was last used
144 */
145 if (sbi->s_cgno[0] == cgno) {
146 UFSD("EXIT\n");
147 return sbi->s_ucpi[0];
148 }
149 /*
150 * Number of cylinder groups is not higher than UFS_MAX_GROUP_LOADED
151 */
152 if (uspi->s_ncg <= UFS_MAX_GROUP_LOADED) {
153 if (sbi->s_cgno[cgno] != UFS_CGNO_EMPTY) {
154 if (sbi->s_cgno[cgno] != cgno) {
155 ufs_panic (sb, "ufs_load_cylinder", "internal error, wrong number of cg in cache");
156 UFSD("EXIT (FAILED)\n");
157 return NULL;
158 }
159 else {
160 UFSD("EXIT\n");
161 return sbi->s_ucpi[cgno];
162 }
163 } else {
164 ufs_read_cylinder (sb, cgno, cgno);
165 UFSD("EXIT\n");
166 return sbi->s_ucpi[cgno];
167 }
168 }
169 /*
170 * Cylinder group number cg is in cache but it was not last used,
171 * we will move to the first position
172 */
173 for (i = 0; i < sbi->s_cg_loaded && sbi->s_cgno[i] != cgno; i++);
174 if (i < sbi->s_cg_loaded && sbi->s_cgno[i] == cgno) {
175 cg = sbi->s_cgno[i];
176 ucpi = sbi->s_ucpi[i];
177 for (j = i; j > 0; j--) {
178 sbi->s_cgno[j] = sbi->s_cgno[j-1];
179 sbi->s_ucpi[j] = sbi->s_ucpi[j-1];
180 }
181 sbi->s_cgno[0] = cg;
182 sbi->s_ucpi[0] = ucpi;
183 /*
184 * Cylinder group number cg is not in cache, we will read it from disk
185 * and put it to the first position
186 */
187 } else {
188 if (sbi->s_cg_loaded < UFS_MAX_GROUP_LOADED)
189 sbi->s_cg_loaded++;
190 else
191 ufs_put_cylinder (sb, UFS_MAX_GROUP_LOADED-1);
192 ucpi = sbi->s_ucpi[sbi->s_cg_loaded - 1];
193 for (j = sbi->s_cg_loaded - 1; j > 0; j--) {
194 sbi->s_cgno[j] = sbi->s_cgno[j-1];
195 sbi->s_ucpi[j] = sbi->s_ucpi[j-1];
196 }
197 sbi->s_ucpi[0] = ucpi;
198 ufs_read_cylinder (sb, cgno, 0);
199 }
200 UFSD("EXIT\n");
201 return sbi->s_ucpi[0];
202 }
203
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