1 /* vi: set sw=4 ts=4: */
3 * res_gdt.c --- reserve blocks for growing the group descriptor table
4 * during online resizing.
6 * Copyright (C) 2002 Andreas Dilger
9 * This file may be redistributed under the terms of the GNU Public
21 * Iterate through the groups which hold BACKUP superblock/GDT copies in an
22 * ext3 filesystem. The counters should be initialized to 1, 5, and 7 before
23 * calling this for the first time. In a sparse filesystem it will be the
24 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
25 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
27 static unsigned int list_backups(ext2_filsys fs, unsigned int *three,
28 unsigned int *five, unsigned int *seven)
30 unsigned int *min = three;
34 if (!(fs->super->s_feature_ro_compat &
35 EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
57 * This code assumes that the reserved blocks have already been marked in-use
58 * during ext2fs_initialize(), so that they are not allocated for other
59 * uses before we can add them to the resize inode (which has to come
60 * after the creation of the inode table).
62 errcode_t ext2fs_create_resize_inode(ext2_filsys fs)
64 errcode_t retval, retval2;
65 struct ext2_super_block *sb;
66 struct ext2_inode inode;
67 __u32 *dindir_buf, *gdt_buf;
69 unsigned long long apb, inode_size;
70 blk_t dindir_blk, rsv_off, gdt_off, gdt_blk;
71 int dindir_dirty = 0, inode_dirty = 0;
73 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
77 retval = ext2fs_get_mem(2 * fs->blocksize, (void *)&dindir_buf);
80 gdt_buf = (__u32 *)((char *)dindir_buf + fs->blocksize);
82 retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
86 /* Maximum possible file size (we donly use the dindirect blocks) */
87 apb = EXT2_ADDR_PER_BLOCK(sb);
88 rsv_add = fs->blocksize / 512;
89 if ((dindir_blk = inode.i_block[EXT2_DIND_BLOCK])) {
91 printf("reading GDT dindir %u\n", dindir_blk);
93 retval = ext2fs_read_ind_block(fs, dindir_blk, dindir_buf);
97 blk_t goal = 3 + sb->s_reserved_gdt_blocks +
98 fs->desc_blocks + fs->inode_blocks_per_group;
100 retval = ext2fs_alloc_block(fs, goal, 0, &dindir_blk);
103 inode.i_mode = LINUX_S_IFREG | 0600;
104 inode.i_links_count = 1;
105 inode.i_block[EXT2_DIND_BLOCK] = dindir_blk;
106 inode.i_blocks = rsv_add;
107 memset(dindir_buf, 0, fs->blocksize);
109 printf("allocated GDT dindir %u\n", dindir_blk);
111 dindir_dirty = inode_dirty = 1;
112 inode_size = apb*apb + apb + EXT2_NDIR_BLOCKS;
113 inode_size *= fs->blocksize;
114 inode.i_size = inode_size & 0xFFFFFFFF;
115 inode.i_size_high = (inode_size >> 32) & 0xFFFFFFFF;
116 if(inode.i_size_high) {
117 sb->s_feature_ro_compat |=
118 EXT2_FEATURE_RO_COMPAT_LARGE_FILE;
120 inode.i_ctime = time(0);
123 for (rsv_off = 0, gdt_off = fs->desc_blocks,
124 gdt_blk = sb->s_first_data_block + 1 + fs->desc_blocks;
125 rsv_off < sb->s_reserved_gdt_blocks;
126 rsv_off++, gdt_off++, gdt_blk++) {
127 unsigned int three = 1, five = 5, seven = 7;
128 unsigned int grp, last = 0;
132 if (!dindir_buf[gdt_off]) {
136 retval = ext2fs_new_block(fs, gdt_blk, 0, &new_blk);
139 if (new_blk != gdt_blk) {
144 gdt_dirty = dindir_dirty = inode_dirty = 1;
145 memset(gdt_buf, 0, fs->blocksize);
146 dindir_buf[gdt_off] = gdt_blk;
147 inode.i_blocks += rsv_add;
149 printf("added primary GDT block %u at %u[%u]\n",
150 gdt_blk, dindir_blk, gdt_off);
152 } else if (dindir_buf[gdt_off] == gdt_blk) {
154 printf("reading primary GDT block %u\n", gdt_blk);
156 retval = ext2fs_read_ind_block(fs, gdt_blk, gdt_buf);
161 printf("bad primary GDT %u != %u at %u[%u]\n",
162 dindir_buf[gdt_off], gdt_blk,dindir_blk,gdt_off);
164 retval = EXT2_ET_RESIZE_INODE_CORRUPT;
168 while ((grp = list_backups(fs, &three, &five, &seven)) <
169 fs->group_desc_count) {
170 blk_t expect = gdt_blk + grp * sb->s_blocks_per_group;
172 if (!gdt_buf[last]) {
174 printf("added backup GDT %u grp %u@%u[%u]\n",
175 expect, grp, gdt_blk, last);
177 gdt_buf[last] = expect;
178 inode.i_blocks += rsv_add;
179 gdt_dirty = inode_dirty = 1;
180 } else if (gdt_buf[last] != expect) {
182 printf("bad backup GDT %u != %u at %u[%u]\n",
183 gdt_buf[last], expect, gdt_blk, last);
185 retval = EXT2_ET_RESIZE_INODE_CORRUPT;
192 printf("writing primary GDT block %u\n", gdt_blk);
194 retval = ext2fs_write_ind_block(fs, gdt_blk, gdt_buf);
202 retval2 = ext2fs_write_ind_block(fs, dindir_blk, dindir_buf);
208 printf("inode.i_blocks = %u, i_size = %u\n", inode.i_blocks,
212 inode.i_atime = inode.i_mtime = time(0);
213 retval2 = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
218 ext2fs_free_mem((void *)&dindir_buf);