1 /* 2 * res_gdt.c --- reserve blocks for growing the group descriptor table 3 * during online resizing. 4 * 5 * Copyright (C) 2002 Andreas Dilger 6 * 7 * %Begin-Header% 8 * This file may be redistributed under the terms of the GNU Public 9 * License. 10 * %End-Header% 11 */ 12 13 #include <stdio.h> 14 #include <string.h> 15 #include <time.h> 16 #include "ext2_fs.h" 17 #include "ext2fs.h" 18 19 /* 20 * Iterate through the groups which hold BACKUP superblock/GDT copies in an 21 * ext3 filesystem. The counters should be initialized to 1, 5, and 7 before 22 * calling this for the first time. In a sparse filesystem it will be the 23 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ... 24 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ... 25 */ 26 static unsigned int list_backups(ext2_filsys fs, unsigned int *three, 27 unsigned int *five, unsigned int *seven) 28 { 29 unsigned int *min = three; 30 int mult = 3; 31 unsigned int ret; 32 33 if (!(fs->super->s_feature_ro_compat & 34 EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)) { 35 ret = *min; 36 *min += 1; 37 return ret; 38 } 39 40 if (*five < *min) { 41 min = five; 42 mult = 5; 43 } 44 if (*seven < *min) { 45 min = seven; 46 mult = 7; 47 } 48 49 ret = *min; 50 *min *= mult; 51 52 return ret; 53 } 54 55 /* 56 * This code assumes that the reserved blocks have already been marked in-use 57 * during ext2fs_initialize(), so that they are not allocated for other 58 * uses before we can add them to the resize inode (which has to come 59 * after the creation of the inode table). 60 */ 61 errcode_t ext2fs_create_resize_inode(ext2_filsys fs) 62 { 63 errcode_t retval, retval2; 64 struct ext2_super_block *sb; 65 struct ext2_inode inode; 66 __u32 *dindir_buf, *gdt_buf; 67 int rsv_add; 68 unsigned long long apb, inode_size; 69 blk_t dindir_blk, rsv_off, gdt_off, gdt_blk; 70 int dindir_dirty = 0, inode_dirty = 0; 71 72 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 73 74 sb = fs->super; 75 76 retval = ext2fs_get_array(2, fs->blocksize, &dindir_buf); 77 if (retval) 78 goto out_free; 79 gdt_buf = (__u32 *)((char *)dindir_buf + fs->blocksize); 80 81 retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode); 82 if (retval) 83 goto out_free; 84 85 /* Maximum possible file size (we donly use the dindirect blocks) */ 86 apb = EXT2_ADDR_PER_BLOCK(sb); 87 rsv_add = fs->blocksize / 512; 88 if ((dindir_blk = inode.i_block[EXT2_DIND_BLOCK])) { 89 #ifdef RES_GDT_DEBUG 90 printf("reading GDT dindir %u\n", dindir_blk); 91 #endif 92 retval = ext2fs_read_ind_block(fs, dindir_blk, dindir_buf); 93 if (retval) 94 goto out_inode; 95 } else { 96 blk_t goal = 3 + sb->s_reserved_gdt_blocks + 97 fs->desc_blocks + fs->inode_blocks_per_group; 98 99 retval = ext2fs_alloc_block(fs, goal, 0, &dindir_blk); 100 if (retval) 101 goto out_free; 102 inode.i_mode = LINUX_S_IFREG | 0600; 103 inode.i_links_count = 1; 104 inode.i_block[EXT2_DIND_BLOCK] = dindir_blk; 105 inode.i_blocks = rsv_add; 106 memset(dindir_buf, 0, fs->blocksize); 107 #ifdef RES_GDT_DEBUG 108 printf("allocated GDT dindir %u\n", dindir_blk); 109 #endif 110 dindir_dirty = inode_dirty = 1; 111 inode_size = apb*apb + apb + EXT2_NDIR_BLOCKS; 112 inode_size *= fs->blocksize; 113 inode.i_size = inode_size & 0xFFFFFFFF; 114 inode.i_size_high = (inode_size >> 32) & 0xFFFFFFFF; 115 if(inode.i_size_high) { 116 sb->s_feature_ro_compat |= 117 EXT2_FEATURE_RO_COMPAT_LARGE_FILE; 118 } 119 inode.i_ctime = fs->now ? fs->now : time(0); 120 } 121 122 for (rsv_off = 0, gdt_off = fs->desc_blocks, 123 gdt_blk = sb->s_first_data_block + 1 + fs->desc_blocks; 124 rsv_off < sb->s_reserved_gdt_blocks; 125 rsv_off++, gdt_off++, gdt_blk++) { 126 unsigned int three = 1, five = 5, seven = 7; 127 unsigned int grp, last = 0; 128 int gdt_dirty = 0; 129 130 gdt_off %= apb; 131 if (!dindir_buf[gdt_off]) { 132 /* FIXME XXX XXX 133 blk_t new_blk; 134 135 retval = ext2fs_new_block(fs, gdt_blk, 0, &new_blk); 136 if (retval) 137 goto out_free; 138 if (new_blk != gdt_blk) { 139 // XXX free block 140 retval = -1; // XXX 141 } 142 */ 143 gdt_dirty = dindir_dirty = inode_dirty = 1; 144 memset(gdt_buf, 0, fs->blocksize); 145 dindir_buf[gdt_off] = gdt_blk; 146 inode.i_blocks += rsv_add; 147 #ifdef RES_GDT_DEBUG 148 printf("added primary GDT block %u at %u[%u]\n", 149 gdt_blk, dindir_blk, gdt_off); 150 #endif 151 } else if (dindir_buf[gdt_off] == gdt_blk) { 152 #ifdef RES_GDT_DEBUG 153 printf("reading primary GDT block %u\n", gdt_blk); 154 #endif 155 retval = ext2fs_read_ind_block(fs, gdt_blk, gdt_buf); 156 if (retval) 157 goto out_dindir; 158 } else { 159 #ifdef RES_GDT_DEBUG 160 printf("bad primary GDT %u != %u at %u[%u]\n", 161 dindir_buf[gdt_off], gdt_blk,dindir_blk,gdt_off); 162 #endif 163 retval = EXT2_ET_RESIZE_INODE_CORRUPT; 164 goto out_dindir; 165 } 166 167 while ((grp = list_backups(fs, &three, &five, &seven)) < 168 fs->group_desc_count) { 169 blk_t expect = gdt_blk + grp * sb->s_blocks_per_group; 170 171 if (!gdt_buf[last]) { 172 #ifdef RES_GDT_DEBUG 173 printf("added backup GDT %u grp %u@%u[%u]\n", 174 expect, grp, gdt_blk, last); 175 #endif 176 gdt_buf[last] = expect; 177 inode.i_blocks += rsv_add; 178 gdt_dirty = inode_dirty = 1; 179 } else if (gdt_buf[last] != expect) { 180 #ifdef RES_GDT_DEBUG 181 printf("bad backup GDT %u != %u at %u[%u]\n", 182 gdt_buf[last], expect, gdt_blk, last); 183 #endif 184 retval = EXT2_ET_RESIZE_INODE_CORRUPT; 185 goto out_dindir; 186 } 187 last++; 188 } 189 if (gdt_dirty) { 190 #ifdef RES_GDT_DEBUG 191 printf("writing primary GDT block %u\n", gdt_blk); 192 #endif 193 retval = ext2fs_write_ind_block(fs, gdt_blk, gdt_buf); 194 if (retval) 195 goto out_dindir; 196 } 197 } 198 199 out_dindir: 200 if (dindir_dirty) { 201 retval2 = ext2fs_write_ind_block(fs, dindir_blk, dindir_buf); 202 if (!retval) 203 retval = retval2; 204 } 205 out_inode: 206 #ifdef RES_GDT_DEBUG 207 printf("inode.i_blocks = %u, i_size = %u\n", inode.i_blocks, 208 inode.i_size); 209 #endif 210 if (inode_dirty) { 211 inode.i_atime = inode.i_mtime = fs->now ? fs->now : time(0); 212 retval2 = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode); 213 if (!retval) 214 retval = retval2; 215 } 216 out_free: 217 ext2fs_free_mem(&dindir_buf); 218 return retval; 219 } 220 221
