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1// SPDX-License-Identifier: GPL-2.02/*3 * linux/fs/ufs/cylinder.c4 *5 * Copyright (C) 19986 * Daniel Pirkl <daniel.pirkl@email.cz>7 * Charles University, Faculty of Mathematics and Physics8 *9 * ext2 - inode (block) bitmap caching inspired10 */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_info27 * 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 buffer47 */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 memory81 * 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 cylinder108 */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 used144 */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_LOADED151 */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 position172 */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 disk185 * and put it to the first position186 */187 } else {188 if (sbi->s_cg_loaded < UFS_MAX_GROUP_LOADED)189 sbi->s_cg_loaded++;190 else191 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