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 bool 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 UCPI_UBH(ucpi)->bh[i] = sb_bread(sb, UCPI_UBH(ucpi)->fragment + i); 51 if (!UCPI_UBH(ucpi)->bh[i]) 52 goto failed; 53 } 54 sbi->s_cgno[bitmap_nr] = cgno; 55 56 ucpi->c_cgx = fs32_to_cpu(sb, ucg->cg_cgx); 57 ucpi->c_ncyl = fs16_to_cpu(sb, ucg->cg_ncyl); 58 ucpi->c_niblk = fs16_to_cpu(sb, ucg->cg_niblk); 59 ucpi->c_ndblk = fs32_to_cpu(sb, ucg->cg_ndblk); 60 ucpi->c_rotor = fs32_to_cpu(sb, ucg->cg_rotor); 61 ucpi->c_frotor = fs32_to_cpu(sb, ucg->cg_frotor); 62 ucpi->c_irotor = fs32_to_cpu(sb, ucg->cg_irotor); 63 ucpi->c_btotoff = fs32_to_cpu(sb, ucg->cg_btotoff); 64 ucpi->c_boff = fs32_to_cpu(sb, ucg->cg_boff); 65 ucpi->c_iusedoff = fs32_to_cpu(sb, ucg->cg_iusedoff); 66 ucpi->c_freeoff = fs32_to_cpu(sb, ucg->cg_freeoff); 67 ucpi->c_nextfreeoff = fs32_to_cpu(sb, ucg->cg_nextfreeoff); 68 ucpi->c_clustersumoff = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_clustersumoff); 69 ucpi->c_clusteroff = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_clusteroff); 70 ucpi->c_nclusterblks = fs32_to_cpu(sb, ucg->cg_u.cg_44.cg_nclusterblks); 71 UFSD("EXIT\n"); 72 return true; 73 74 failed: 75 for (j = 1; j < i; j++) 76 brelse(UCPI_UBH(ucpi)->bh[j]); 77 sbi->s_cgno[bitmap_nr] = UFS_CGNO_EMPTY; 78 ufs_error (sb, "ufs_read_cylinder", "can't read cylinder group block %u", cgno); 79 return false; 80 } 81 82 /* 83 * Remove cylinder group from cache, doesn't release memory 84 * allocated for cylinder group (this is done at ufs_put_super only). 85 */ 86 void ufs_put_cylinder (struct super_block * sb, unsigned bitmap_nr) 87 { 88 struct ufs_sb_info * sbi = UFS_SB(sb); 89 struct ufs_sb_private_info * uspi; 90 struct ufs_cg_private_info * ucpi; 91 struct ufs_cylinder_group * ucg; 92 unsigned i; 93 94 UFSD("ENTER, bitmap_nr %u\n", bitmap_nr); 95 96 uspi = sbi->s_uspi; 97 if (sbi->s_cgno[bitmap_nr] == UFS_CGNO_EMPTY) { 98 UFSD("EXIT\n"); 99 return; 100 } 101 ucpi = sbi->s_ucpi[bitmap_nr]; 102 ucg = ubh_get_ucg(UCPI_UBH(ucpi)); 103 104 if (uspi->s_ncg > UFS_MAX_GROUP_LOADED && bitmap_nr >= sbi->s_cg_loaded) { 105 ufs_panic (sb, "ufs_put_cylinder", "internal error"); 106 return; 107 } 108 /* 109 * rotor is not so important data, so we put it to disk 110 * at the end of working with cylinder 111 */ 112 ucg->cg_rotor = cpu_to_fs32(sb, ucpi->c_rotor); 113 ucg->cg_frotor = cpu_to_fs32(sb, ucpi->c_frotor); 114 ucg->cg_irotor = cpu_to_fs32(sb, ucpi->c_irotor); 115 ubh_mark_buffer_dirty (UCPI_UBH(ucpi)); 116 for (i = 1; i < UCPI_UBH(ucpi)->count; i++) { 117 brelse (UCPI_UBH(ucpi)->bh[i]); 118 } 119 120 sbi->s_cgno[bitmap_nr] = UFS_CGNO_EMPTY; 121 UFSD("EXIT\n"); 122 } 123 124 /* 125 * Find cylinder group in cache and return it as pointer. 126 * If cylinder group is not in cache, we will load it from disk. 127 * 128 * The cache is managed by LRU algorithm. 129 */ 130 struct ufs_cg_private_info * ufs_load_cylinder ( 131 struct super_block * sb, unsigned cgno) 132 { 133 struct ufs_sb_info * sbi = UFS_SB(sb); 134 struct ufs_sb_private_info * uspi; 135 struct ufs_cg_private_info * ucpi; 136 unsigned cg, i, j; 137 138 UFSD("ENTER, cgno %u\n", cgno); 139 140 uspi = sbi->s_uspi; 141 if (cgno >= uspi->s_ncg) { 142 ufs_panic (sb, "ufs_load_cylinder", "internal error, high number of cg"); 143 return NULL; 144 } 145 /* 146 * Cylinder group number cg it in cache and it was last used 147 */ 148 if (sbi->s_cgno[0] == cgno) { 149 UFSD("EXIT\n"); 150 return sbi->s_ucpi[0]; 151 } 152 /* 153 * Number of cylinder groups is not higher than UFS_MAX_GROUP_LOADED 154 */ 155 if (uspi->s_ncg <= UFS_MAX_GROUP_LOADED) { 156 if (sbi->s_cgno[cgno] != UFS_CGNO_EMPTY) { 157 if (sbi->s_cgno[cgno] != cgno) { 158 ufs_panic (sb, "ufs_load_cylinder", "internal error, wrong number of cg in cache"); 159 UFSD("EXIT (FAILED)\n"); 160 return NULL; 161 } 162 } else { 163 if (unlikely(!ufs_read_cylinder (sb, cgno, cgno))) { 164 UFSD("EXIT (FAILED)\n"); 165 return NULL; 166 } 167 } 168 UFSD("EXIT\n"); 169 return sbi->s_ucpi[cgno]; 170 } 171 /* 172 * Cylinder group number cg is in cache but it was not last used, 173 * we will move to the first position 174 */ 175 for (i = 0; i < sbi->s_cg_loaded && sbi->s_cgno[i] != cgno; i++); 176 if (i < sbi->s_cg_loaded && sbi->s_cgno[i] == cgno) { 177 cg = sbi->s_cgno[i]; 178 ucpi = sbi->s_ucpi[i]; 179 for (j = i; j > 0; j--) { 180 sbi->s_cgno[j] = sbi->s_cgno[j-1]; 181 sbi->s_ucpi[j] = sbi->s_ucpi[j-1]; 182 } 183 sbi->s_cgno[0] = cg; 184 sbi->s_ucpi[0] = ucpi; 185 /* 186 * Cylinder group number cg is not in cache, we will read it from disk 187 * and put it to the first position 188 */ 189 } else { 190 if (sbi->s_cg_loaded < UFS_MAX_GROUP_LOADED) 191 sbi->s_cg_loaded++; 192 else 193 ufs_put_cylinder (sb, UFS_MAX_GROUP_LOADED-1); 194 ucpi = sbi->s_ucpi[sbi->s_cg_loaded - 1]; 195 for (j = sbi->s_cg_loaded - 1; j > 0; j--) { 196 sbi->s_cgno[j] = sbi->s_cgno[j-1]; 197 sbi->s_ucpi[j] = sbi->s_ucpi[j-1]; 198 } 199 sbi->s_ucpi[0] = ucpi; 200 if (unlikely(!ufs_read_cylinder (sb, cgno, 0))) { 201 UFSD("EXIT (FAILED)\n"); 202 return NULL; 203 } 204 } 205 UFSD("EXIT\n"); 206 return sbi->s_ucpi[0]; 207 } 208