res_gdt.c revision 1b4cd9c7464d5bd0f5b416c7303bcc827e312473
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 */ 26static 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 */ 61errcode_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 if (!sb->s_reserved_gdt_blocks) 76 return 0; 77 78 retval = ext2fs_get_mem(2 * fs->blocksize, (void **)&dindir_buf); 79 if (retval) 80 goto out_free; 81 gdt_buf = (__u32 *)((char *)dindir_buf + fs->blocksize); 82 83 retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode); 84 if (retval) 85 goto out_free; 86 87 /* Maximum possible file size (we donly use the dindirect blocks) */ 88 apb = EXT2_ADDR_PER_BLOCK(sb); 89 rsv_add = fs->blocksize / 512; 90 if ((dindir_blk = inode.i_block[EXT2_DIND_BLOCK])) { 91 printf("reading GDT dindir %u\n", dindir_blk); 92 retval = io_channel_read_blk(fs->io, dindir_blk, 1, 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 = time(0); 120 } 121 122 for (rsv_off = 0, gdt_off = fs->desc_blocks, 123 gdt_blk = sb->s_first_data_block + 1 + gdt_off; 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 printf("reading primary GDT block %u\n", gdt_blk); 153 retval = io_channel_read_blk(fs->io,gdt_blk,1,gdt_buf); 154 if (retval) 155 goto out_dindir; 156 } else { 157 printf("bad primary GDT %u != %u at %u[%u]\n", 158 dindir_buf[gdt_off], gdt_blk,dindir_blk,gdt_off); 159 retval = -1; // XXX 160 goto out_dindir; 161 } 162 163 while ((grp = list_backups(fs, &three, &five, &seven)) < 164 fs->group_desc_count) { 165 blk_t expect = gdt_blk + grp * sb->s_blocks_per_group; 166 167 if (!gdt_buf[last]) { 168#ifdef RES_GDT_DEBUG 169 printf("added backup GDT %u grp %u@%u[%u]\n", 170 expect, grp, gdt_blk, last); 171#endif 172 gdt_buf[last] = expect; 173 inode.i_blocks += rsv_add; 174 gdt_dirty = inode_dirty = 1; 175 } else if (gdt_buf[last] != expect) { 176 printf("bad backup GDT %u != %u at %u[%u]\n", 177 gdt_buf[last], expect, gdt_blk, last); 178 retval = -1; // XXX 179 goto out_dindir; 180 } 181 last++; 182 } 183 if (gdt_dirty) { 184#ifdef RES_GDT_DEBUG 185 printf("writing primary GDT block %u\n", gdt_blk); 186#endif 187 retval = io_channel_write_blk(fs->io,gdt_blk,1,gdt_buf); 188 if (retval) 189 goto out_dindir; 190 } 191 } 192 193out_dindir: 194 if (dindir_dirty) { 195 retval2 = io_channel_write_blk(fs->io, dindir_blk,1,dindir_buf); 196 if (!retval) 197 retval = retval2; 198 } 199out_inode: 200 printf("inode.i_blocks = %u, i_size = %u\n", inode.i_blocks, 201 inode.i_size); 202 if (inode_dirty) { 203 inode.i_atime = inode.i_mtime = time(0); 204 retval2 = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode); 205 if (!retval) 206 retval = retval2; 207 } 208out_free: 209 ext2fs_free_mem((void **)&dindir_buf); 210 return retval; 211} 212 213