[1765] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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| 3 | * res_gdt.c --- reserve blocks for growing the group descriptor table
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| 4 | * during online resizing.
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| 5 | *
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| 6 | * Copyright (C) 2002 Andreas Dilger
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| 7 | *
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| 8 | * %Begin-Header%
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| 9 | * This file may be redistributed under the terms of the GNU Public
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| 10 | * License.
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| 11 | * %End-Header%
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| 12 | */
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| 13 |
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| 14 | #include <stdio.h>
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| 15 | #include <string.h>
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| 16 | #include <time.h>
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| 17 | #include "ext2_fs.h"
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| 18 | #include "ext2fs.h"
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| 19 |
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| 20 | /*
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| 21 | * Iterate through the groups which hold BACKUP superblock/GDT copies in an
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| 22 | * ext3 filesystem. The counters should be initialized to 1, 5, and 7 before
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| 23 | * calling this for the first time. In a sparse filesystem it will be the
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| 24 | * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
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| 25 | * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
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| 26 | */
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| 27 | static unsigned int list_backups(ext2_filsys fs, unsigned int *three,
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| 28 | unsigned int *five, unsigned int *seven)
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| 29 | {
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| 30 | unsigned int *min = three;
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| 31 | int mult = 3;
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| 32 | unsigned int ret;
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| 33 |
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| 34 | if (!(fs->super->s_feature_ro_compat &
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| 35 | EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
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| 36 | ret = *min;
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| 37 | *min += 1;
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| 38 | return ret;
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| 39 | }
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| 40 |
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| 41 | if (*five < *min) {
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| 42 | min = five;
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| 43 | mult = 5;
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| 44 | }
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| 45 | if (*seven < *min) {
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| 46 | min = seven;
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| 47 | mult = 7;
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| 48 | }
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| 49 |
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| 50 | ret = *min;
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| 51 | *min *= mult;
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| 52 |
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| 53 | return ret;
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| 54 | }
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| 55 |
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| 56 | /*
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| 57 | * This code assumes that the reserved blocks have already been marked in-use
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| 58 | * during ext2fs_initialize(), so that they are not allocated for other
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| 59 | * uses before we can add them to the resize inode (which has to come
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| 60 | * after the creation of the inode table).
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| 61 | */
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| 62 | errcode_t ext2fs_create_resize_inode(ext2_filsys fs)
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| 63 | {
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| 64 | errcode_t retval, retval2;
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| 65 | struct ext2_super_block *sb;
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| 66 | struct ext2_inode inode;
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| 67 | __u32 *dindir_buf, *gdt_buf;
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| 68 | int rsv_add;
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| 69 | unsigned long long apb, inode_size;
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| 70 | blk_t dindir_blk, rsv_off, gdt_off, gdt_blk;
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| 71 | int dindir_dirty = 0, inode_dirty = 0;
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| 72 |
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| 73 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
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| 74 |
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| 75 | sb = fs->super;
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| 76 |
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| 77 | retval = ext2fs_get_mem(2 * fs->blocksize, (void *)&dindir_buf);
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| 78 | if (retval)
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| 79 | goto out_free;
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| 80 | gdt_buf = (__u32 *)((char *)dindir_buf + fs->blocksize);
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| 81 |
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| 82 | retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
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| 83 | if (retval)
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| 84 | goto out_free;
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| 85 |
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| 86 | /* Maximum possible file size (we donly use the dindirect blocks) */
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| 87 | apb = EXT2_ADDR_PER_BLOCK(sb);
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| 88 | rsv_add = fs->blocksize / 512;
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| 89 | if ((dindir_blk = inode.i_block[EXT2_DIND_BLOCK])) {
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| 90 | #ifdef RES_GDT_DEBUG
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| 91 | printf("reading GDT dindir %u\n", dindir_blk);
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| 92 | #endif
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| 93 | retval = ext2fs_read_ind_block(fs, dindir_blk, dindir_buf);
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| 94 | if (retval)
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| 95 | goto out_inode;
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| 96 | } else {
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| 97 | blk_t goal = 3 + sb->s_reserved_gdt_blocks +
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| 98 | fs->desc_blocks + fs->inode_blocks_per_group;
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| 99 |
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| 100 | retval = ext2fs_alloc_block(fs, goal, 0, &dindir_blk);
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| 101 | if (retval)
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| 102 | goto out_free;
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| 103 | inode.i_mode = LINUX_S_IFREG | 0600;
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| 104 | inode.i_links_count = 1;
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| 105 | inode.i_block[EXT2_DIND_BLOCK] = dindir_blk;
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| 106 | inode.i_blocks = rsv_add;
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| 107 | memset(dindir_buf, 0, fs->blocksize);
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| 108 | #ifdef RES_GDT_DEBUG
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| 109 | printf("allocated GDT dindir %u\n", dindir_blk);
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| 110 | #endif
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| 111 | dindir_dirty = inode_dirty = 1;
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| 112 | inode_size = apb*apb + apb + EXT2_NDIR_BLOCKS;
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| 113 | inode_size *= fs->blocksize;
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| 114 | inode.i_size = inode_size & 0xFFFFFFFF;
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| 115 | inode.i_size_high = (inode_size >> 32) & 0xFFFFFFFF;
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| 116 | if(inode.i_size_high) {
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| 117 | sb->s_feature_ro_compat |=
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| 118 | EXT2_FEATURE_RO_COMPAT_LARGE_FILE;
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| 119 | }
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| 120 | inode.i_ctime = time(0);
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| 121 | }
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| 122 |
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| 123 | for (rsv_off = 0, gdt_off = fs->desc_blocks,
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| 124 | gdt_blk = sb->s_first_data_block + 1 + fs->desc_blocks;
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| 125 | rsv_off < sb->s_reserved_gdt_blocks;
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| 126 | rsv_off++, gdt_off++, gdt_blk++) {
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| 127 | unsigned int three = 1, five = 5, seven = 7;
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| 128 | unsigned int grp, last = 0;
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| 129 | int gdt_dirty = 0;
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| 130 |
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| 131 | gdt_off %= apb;
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| 132 | if (!dindir_buf[gdt_off]) {
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| 133 | /* FIXME XXX XXX
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| 134 | blk_t new_blk;
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| 135 |
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| 136 | retval = ext2fs_new_block(fs, gdt_blk, 0, &new_blk);
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| 137 | if (retval)
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| 138 | goto out_free;
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| 139 | if (new_blk != gdt_blk) {
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| 140 | // XXX free block
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| 141 | retval = -1; // XXX
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| 142 | }
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| 143 | */
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| 144 | gdt_dirty = dindir_dirty = inode_dirty = 1;
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| 145 | memset(gdt_buf, 0, fs->blocksize);
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| 146 | dindir_buf[gdt_off] = gdt_blk;
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| 147 | inode.i_blocks += rsv_add;
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| 148 | #ifdef RES_GDT_DEBUG
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| 149 | printf("added primary GDT block %u at %u[%u]\n",
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| 150 | gdt_blk, dindir_blk, gdt_off);
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| 151 | #endif
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| 152 | } else if (dindir_buf[gdt_off] == gdt_blk) {
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| 153 | #ifdef RES_GDT_DEBUG
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| 154 | printf("reading primary GDT block %u\n", gdt_blk);
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| 155 | #endif
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| 156 | retval = ext2fs_read_ind_block(fs, gdt_blk, gdt_buf);
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| 157 | if (retval)
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| 158 | goto out_dindir;
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| 159 | } else {
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| 160 | #ifdef RES_GDT_DEBUG
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| 161 | printf("bad primary GDT %u != %u at %u[%u]\n",
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| 162 | dindir_buf[gdt_off], gdt_blk,dindir_blk,gdt_off);
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| 163 | #endif
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| 164 | retval = EXT2_ET_RESIZE_INODE_CORRUPT;
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| 165 | goto out_dindir;
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| 166 | }
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| 167 |
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| 168 | while ((grp = list_backups(fs, &three, &five, &seven)) <
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| 169 | fs->group_desc_count) {
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| 170 | blk_t expect = gdt_blk + grp * sb->s_blocks_per_group;
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| 171 |
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| 172 | if (!gdt_buf[last]) {
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| 173 | #ifdef RES_GDT_DEBUG
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| 174 | printf("added backup GDT %u grp %u@%u[%u]\n",
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| 175 | expect, grp, gdt_blk, last);
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| 176 | #endif
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| 177 | gdt_buf[last] = expect;
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| 178 | inode.i_blocks += rsv_add;
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| 179 | gdt_dirty = inode_dirty = 1;
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| 180 | } else if (gdt_buf[last] != expect) {
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| 181 | #ifdef RES_GDT_DEBUG
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| 182 | printf("bad backup GDT %u != %u at %u[%u]\n",
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| 183 | gdt_buf[last], expect, gdt_blk, last);
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| 184 | #endif
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| 185 | retval = EXT2_ET_RESIZE_INODE_CORRUPT;
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| 186 | goto out_dindir;
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| 187 | }
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| 188 | last++;
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| 189 | }
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| 190 | if (gdt_dirty) {
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| 191 | #ifdef RES_GDT_DEBUG
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| 192 | printf("writing primary GDT block %u\n", gdt_blk);
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| 193 | #endif
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| 194 | retval = ext2fs_write_ind_block(fs, gdt_blk, gdt_buf);
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| 195 | if (retval)
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| 196 | goto out_dindir;
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| 197 | }
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| 198 | }
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| 199 |
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| 200 | out_dindir:
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| 201 | if (dindir_dirty) {
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| 202 | retval2 = ext2fs_write_ind_block(fs, dindir_blk, dindir_buf);
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| 203 | if (!retval)
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| 204 | retval = retval2;
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| 205 | }
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| 206 | out_inode:
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| 207 | #ifdef RES_GDT_DEBUG
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| 208 | printf("inode.i_blocks = %u, i_size = %u\n", inode.i_blocks,
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| 209 | inode.i_size);
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| 210 | #endif
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| 211 | if (inode_dirty) {
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| 212 | inode.i_atime = inode.i_mtime = time(0);
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| 213 | retval2 = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
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| 214 | if (!retval)
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| 215 | retval = retval2;
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| 216 | }
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| 217 | out_free:
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| 218 | ext2fs_free_mem((void *)&dindir_buf);
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| 219 | return retval;
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| 220 | }
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| 221 |
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