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 /* FIXME-64 - can't deal with extents */ 69 blk_t dindir_blk, rsv_off, gdt_off, gdt_blk; 70 int dindir_dirty = 0, inode_dirty = 0, sb_blk = 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 return retval; 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 /* 86 * File systems with a blocksize of 1024 and bigalloc have 87 * sb->s_first_data_block of 0; yet the superblock is still at 88 * block #1. We compensate for it here. 89 */ 90 sb_blk = sb->s_first_data_block; 91 if (fs->blocksize == 1024 && sb_blk == 0) 92 sb_blk = 1; 93 94 /* Maximum possible file size (we donly use the dindirect blocks) */ 95 apb = EXT2_ADDR_PER_BLOCK(sb); 96 if ((dindir_blk = inode.i_block[EXT2_DIND_BLOCK])) { 97 #ifdef RES_GDT_DEBUG 98 printf("reading GDT dindir %u\n", dindir_blk); 99 #endif 100 retval = ext2fs_read_ind_block(fs, dindir_blk, dindir_buf); 101 if (retval) 102 goto out_inode; 103 } else { 104 blk_t goal = sb_blk + fs->desc_blocks + 105 sb->s_reserved_gdt_blocks + 2 + 106 fs->inode_blocks_per_group; 107 108 retval = ext2fs_alloc_block(fs, goal, 0, &dindir_blk); 109 if (retval) 110 goto out_free; 111 inode.i_mode = LINUX_S_IFREG | 0600; 112 inode.i_links_count = 1; 113 inode.i_block[EXT2_DIND_BLOCK] = dindir_blk; 114 ext2fs_iblk_set(fs, &inode, 1); 115 memset(dindir_buf, 0, fs->blocksize); 116 #ifdef RES_GDT_DEBUG 117 printf("allocated GDT dindir %u\n", dindir_blk); 118 #endif 119 dindir_dirty = inode_dirty = 1; 120 inode_size = apb*apb + apb + EXT2_NDIR_BLOCKS; 121 inode_size *= fs->blocksize; 122 inode.i_size = inode_size & 0xFFFFFFFF; 123 inode.i_size_high = (inode_size >> 32) & 0xFFFFFFFF; 124 if(inode.i_size_high) { 125 sb->s_feature_ro_compat |= 126 EXT2_FEATURE_RO_COMPAT_LARGE_FILE; 127 } 128 inode.i_ctime = fs->now ? fs->now : time(0); 129 } 130 131 for (rsv_off = 0, gdt_off = fs->desc_blocks, 132 gdt_blk = sb_blk + 1 + fs->desc_blocks; 133 rsv_off < sb->s_reserved_gdt_blocks; 134 rsv_off++, gdt_off++, gdt_blk++) { 135 unsigned int three = 1, five = 5, seven = 7; 136 unsigned int grp, last = 0; 137 int gdt_dirty = 0; 138 139 gdt_off %= apb; 140 if (!dindir_buf[gdt_off]) { 141 /* FIXME XXX XXX 142 blk_t new_blk; 143 144 retval = ext2fs_new_block(fs, gdt_blk, 0, &new_blk); 145 if (retval) 146 goto out_free; 147 if (new_blk != gdt_blk) { 148 // XXX free block 149 retval = -1; // XXX 150 } 151 */ 152 gdt_dirty = dindir_dirty = inode_dirty = 1; 153 memset(gdt_buf, 0, fs->blocksize); 154 dindir_buf[gdt_off] = gdt_blk; 155 ext2fs_iblk_add_blocks(fs, &inode, 1); 156 #ifdef RES_GDT_DEBUG 157 printf("added primary GDT block %u at %u[%u]\n", 158 gdt_blk, dindir_blk, gdt_off); 159 #endif 160 } else if (dindir_buf[gdt_off] == gdt_blk) { 161 #ifdef RES_GDT_DEBUG 162 printf("reading primary GDT block %u\n", gdt_blk); 163 #endif 164 retval = ext2fs_read_ind_block(fs, gdt_blk, gdt_buf); 165 if (retval) 166 goto out_dindir; 167 } else { 168 #ifdef RES_GDT_DEBUG 169 printf("bad primary GDT %u != %u at %u[%u]\n", 170 dindir_buf[gdt_off], gdt_blk,dindir_blk,gdt_off); 171 #endif 172 retval = EXT2_ET_RESIZE_INODE_CORRUPT; 173 goto out_dindir; 174 } 175 176 while ((grp = list_backups(fs, &three, &five, &seven)) < 177 fs->group_desc_count) { 178 blk_t expect = gdt_blk + grp * sb->s_blocks_per_group; 179 180 if (!gdt_buf[last]) { 181 #ifdef RES_GDT_DEBUG 182 printf("added backup GDT %u grp %u@%u[%u]\n", 183 expect, grp, gdt_blk, last); 184 #endif 185 gdt_buf[last] = expect; 186 ext2fs_iblk_add_blocks(fs, &inode, 1); 187 gdt_dirty = inode_dirty = 1; 188 } else if (gdt_buf[last] != expect) { 189 #ifdef RES_GDT_DEBUG 190 printf("bad backup GDT %u != %u at %u[%u]\n", 191 gdt_buf[last], expect, gdt_blk, last); 192 #endif 193 retval = EXT2_ET_RESIZE_INODE_CORRUPT; 194 goto out_dindir; 195 } 196 last++; 197 } 198 if (gdt_dirty) { 199 #ifdef RES_GDT_DEBUG 200 printf("writing primary GDT block %u\n", gdt_blk); 201 #endif 202 retval = ext2fs_write_ind_block(fs, gdt_blk, gdt_buf); 203 if (retval) 204 goto out_dindir; 205 } 206 } 207 208 out_dindir: 209 if (dindir_dirty) { 210 retval2 = ext2fs_write_ind_block(fs, dindir_blk, dindir_buf); 211 if (!retval) 212 retval = retval2; 213 } 214 out_inode: 215 #ifdef RES_GDT_DEBUG 216 printf("inode.i_blocks = %u, i_size = %u\n", inode.i_blocks, 217 inode.i_size); 218 #endif 219 if (inode_dirty) { 220 inode.i_atime = inode.i_mtime = fs->now ? fs->now : time(0); 221 retval2 = ext2fs_write_new_inode(fs, EXT2_RESIZE_INO, &inode); 222 if (!retval) 223 retval = retval2; 224 } 225 out_free: 226 ext2fs_free_mem(&dindir_buf); 227 return retval; 228 } 229 230
