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 Library 9 * General Public License, version 2. 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 unsigned long long apb, inode_size; 68 blk_t dindir_blk, rsv_off, gdt_off, gdt_blk; 69 int dindir_dirty = 0, inode_dirty = 0; 70 71 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 72 73 sb = fs->super; 74 75 retval = ext2fs_get_array(2, fs->blocksize, &dindir_buf); 76 if (retval) 77 goto out_free; 78 gdt_buf = (__u32 *)((char *)dindir_buf + fs->blocksize); 79 80 retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode); 81 if (retval) 82 goto out_free; 83 84 /* Maximum possible file size (we donly use the dindirect blocks) */ 85 apb = EXT2_ADDR_PER_BLOCK(sb); 86 if ((dindir_blk = inode.i_block[EXT2_DIND_BLOCK])) { 87 #ifdef RES_GDT_DEBUG 88 printf("reading GDT dindir %u\n", dindir_blk); 89 #endif 90 retval = ext2fs_read_ind_block(fs, dindir_blk, dindir_buf); 91 if (retval) 92 goto out_inode; 93 } else { 94 blk_t goal = sb->s_first_data_block + fs->desc_blocks + 95 sb->s_reserved_gdt_blocks + 2 + 96 fs->inode_blocks_per_group; 97 98 retval = ext2fs_alloc_block(fs, goal, 0, &dindir_blk); 99 if (retval) 100 goto out_free; 101 inode.i_mode = LINUX_S_IFREG | 0600; 102 inode.i_links_count = 1; 103 inode.i_block[EXT2_DIND_BLOCK] = dindir_blk; 104 ext2fs_iblk_set(fs, &inode, 1); 105 memset(dindir_buf, 0, fs->blocksize); 106 #ifdef RES_GDT_DEBUG 107 printf("allocated GDT dindir %u\n", dindir_blk); 108 #endif 109 dindir_dirty = inode_dirty = 1; 110 inode_size = apb*apb + apb + EXT2_NDIR_BLOCKS; 111 inode_size *= fs->blocksize; 112 inode.i_size = inode_size & 0xFFFFFFFF; 113 inode.i_size_high = (inode_size >> 32) & 0xFFFFFFFF; 114 if(inode.i_size_high) { 115 sb->s_feature_ro_compat |= 116 EXT2_FEATURE_RO_COMPAT_LARGE_FILE; 117 } 118 inode.i_ctime = fs->now ? fs->now : time(0); 119 } 120 121 for (rsv_off = 0, gdt_off = fs->desc_blocks, 122 gdt_blk = sb->s_first_data_block + 1 + fs->desc_blocks; 123 rsv_off < sb->s_reserved_gdt_blocks; 124 rsv_off++, gdt_off++, gdt_blk++) { 125 unsigned int three = 1, five = 5, seven = 7; 126 unsigned int grp, last = 0; 127 int gdt_dirty = 0; 128 129 gdt_off %= apb; 130 if (!dindir_buf[gdt_off]) { 131 /* FIXME XXX XXX 132 blk_t new_blk; 133 134 retval = ext2fs_new_block(fs, gdt_blk, 0, &new_blk); 135 if (retval) 136 goto out_free; 137 if (new_blk != gdt_blk) { 138 // XXX free block 139 retval = -1; // XXX 140 } 141 */ 142 gdt_dirty = dindir_dirty = inode_dirty = 1; 143 memset(gdt_buf, 0, fs->blocksize); 144 dindir_buf[gdt_off] = gdt_blk; 145 ext2fs_iblk_add_blocks(fs, &inode, 1); 146 #ifdef RES_GDT_DEBUG 147 printf("added primary GDT block %u at %u[%u]\n", 148 gdt_blk, dindir_blk, gdt_off); 149 #endif 150 } else if (dindir_buf[gdt_off] == gdt_blk) { 151 #ifdef RES_GDT_DEBUG 152 printf("reading primary GDT block %u\n", gdt_blk); 153 #endif 154 retval = ext2fs_read_ind_block(fs, gdt_blk, gdt_buf); 155 if (retval) 156 goto out_dindir; 157 } else { 158 #ifdef RES_GDT_DEBUG 159 printf("bad primary GDT %u != %u at %u[%u]\n", 160 dindir_buf[gdt_off], gdt_blk,dindir_blk,gdt_off); 161 #endif 162 retval = EXT2_ET_RESIZE_INODE_CORRUPT; 163 goto out_dindir; 164 } 165 166 while ((grp = list_backups(fs, &three, &five, &seven)) < 167 fs->group_desc_count) { 168 blk_t expect = gdt_blk + grp * sb->s_blocks_per_group; 169 170 if (!gdt_buf[last]) { 171 #ifdef RES_GDT_DEBUG 172 printf("added backup GDT %u grp %u@%u[%u]\n", 173 expect, grp, gdt_blk, last); 174 #endif 175 gdt_buf[last] = expect; 176 ext2fs_iblk_add_blocks(fs, &inode, 1); 177 gdt_dirty = inode_dirty = 1; 178 } else if (gdt_buf[last] != expect) { 179 #ifdef RES_GDT_DEBUG 180 printf("bad backup GDT %u != %u at %u[%u]\n", 181 gdt_buf[last], expect, gdt_blk, last); 182 #endif 183 retval = EXT2_ET_RESIZE_INODE_CORRUPT; 184 goto out_dindir; 185 } 186 last++; 187 } 188 if (gdt_dirty) { 189 #ifdef RES_GDT_DEBUG 190 printf("writing primary GDT block %u\n", gdt_blk); 191 #endif 192 retval = ext2fs_write_ind_block(fs, gdt_blk, gdt_buf); 193 if (retval) 194 goto out_dindir; 195 } 196 } 197 198 out_dindir: 199 if (dindir_dirty) { 200 retval2 = ext2fs_write_ind_block(fs, dindir_blk, dindir_buf); 201 if (!retval) 202 retval = retval2; 203 } 204 out_inode: 205 #ifdef RES_GDT_DEBUG 206 printf("inode.i_blocks = %u, i_size = %u\n", inode.i_blocks, 207 inode.i_size); 208 #endif 209 if (inode_dirty) { 210 inode.i_atime = inode.i_mtime = fs->now ? fs->now : time(0); 211 retval2 = ext2fs_write_new_inode(fs, EXT2_RESIZE_INO, &inode); 212 if (!retval) 213 retval = retval2; 214 } 215 out_free: 216 ext2fs_free_mem(&dindir_buf); 217 return retval; 218 } 219 220
