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 */ 29static 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 72failed: 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 */ 83void 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 */ 127struct 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