online.c revision bf69235ad0073c80386b70caba0e1b58e5f85697 
1/*
2 * online.c --- Do on-line resizing of the ext3 filesystem
3 *
4 * Copyright (C) 2006 by Theodore Ts'o
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Public
8 * License.
9 * %End-Header%
10 */
11
12#include "resize2fs.h"
13#ifdef HAVE_SYS_IOCTL_H
14#include <sys/ioctl.h>
15#endif
16#include <sys/stat.h>
17#include <fcntl.h>
18
19extern char *program_name;
20
21errcode_t online_resize_fs(ext2_filsys fs, const char *mtpt,
22			   blk_t *new_size, int flags)
23{
24	struct ext2_new_group_input input;
25	struct ext2_super_block *sb = fs->super;
26	ext2_filsys 		new_fs;
27	errcode_t 		retval;
28	dgrp_t			i;
29	blk_t			size;
30	int			fd, r_frac, overhead;
31
32	printf(_("Filesystem at %s is mounted on %s; "
33		 "on-line resizing required\n"), fs->device_name, mtpt);
34
35	if (*new_size < sb->s_blocks_count) {
36		printf(_("On-line shrinking from %u to %u not supported.\n"),
37		       sb->s_blocks_count, *new_size);
38		exit(1);
39	}
40
41	fd = open(mtpt, O_RDONLY);
42	if (fd < 0) {
43		com_err(program_name, errno,
44			_("while trying to open mountpoint %s"), mtpt);
45		exit(1);
46	}
47
48	size=sb->s_blocks_count;
49	if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
50		if (errno == EPERM)
51			com_err(program_name, 0,
52				_("Permission denied to resize filesystem"));
53		else if (errno == ENOTTY)
54			com_err(program_name, 0,
55			_("Filesystem does not support online resizing"));
56		else
57			com_err(program_name, errno,
58			_("While checking for on-line resizing support"));
59		exit(1);
60	}
61
62	r_frac = ((100 * sb->s_r_blocks_count) + sb->s_blocks_count-1) /
63		sb->s_blocks_count;
64
65	retval = ext2fs_read_bitmaps(fs);
66	if (retval)
67		return retval;
68
69	retval = ext2fs_dup_handle(fs, &new_fs);
70	if (retval)
71		return retval;
72
73	retval = adjust_fs_info(new_fs, fs, *new_size);
74	if (retval)
75		return retval;
76
77	printf(_("Performing an on-line resize of %s to %d (%dk) blocks.\n"),
78	       fs->device_name, *new_size, fs->blocksize / 1024);
79
80	size = fs->group_desc_count * sb->s_blocks_per_group +
81		sb->s_first_data_block;
82	if (size > *new_size)
83		size = *new_size;
84
85	if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
86		com_err(program_name, errno,
87			_("While trying to extend the last group"));
88		exit(1);
89	}
90
91	for (i = fs->group_desc_count;
92	     i < new_fs->group_desc_count; i++) {
93
94		overhead = (int) (2 + new_fs->inode_blocks_per_group);
95
96		if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1))
97			overhead += 1 + new_fs->desc_blocks +
98				new_fs->super->s_reserved_gdt_blocks;
99
100		input.group = i;
101		input.block_bitmap = new_fs->group_desc[i].bg_block_bitmap;
102		input.inode_bitmap = new_fs->group_desc[i].bg_inode_bitmap;
103		input.inode_table = new_fs->group_desc[i].bg_inode_table;
104		input.blocks_count = sb->s_blocks_per_group;
105		if (i == new_fs->group_desc_count-1) {
106			input.blocks_count = new_fs->super->s_blocks_count -
107				sb->s_first_data_block -
108				(i * sb->s_blocks_per_group);
109		}
110		input.reserved_blocks = input.blocks_count * r_frac / 100;
111
112#if 0
113		printf("new block bitmap is at 0x%04x\n", input.block_bitmap);
114		printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap);
115		printf("new inode table is at 0x%04x-0x%04x\n",
116		       input.inode_table,
117		       input.inode_table + new_fs->inode_blocks_per_group-1);
118		printf("new group has %d blocks\n", input.blocks_count);
119		printf("new group will reserve %d blocks\n",
120		       input.reserved_blocks);
121		printf("new group has %d free blocks\n",
122		       new_fs->group_desc[i].bg_free_blocks_count);
123		printf("new group has %d free inodes (%d blocks)\n",
124		       new_fs->group_desc[i].bg_free_inodes_count,
125		       new_fs->inode_blocks_per_group);
126		printf("Adding group #%d\n", input.group);
127#endif
128
129		if (ioctl(fd, EXT2_IOC_GROUP_ADD, &input) < 0) {
130			com_err(program_name, errno,
131				_("While trying to add group #%d"),
132				input.group);
133			exit(1);
134		}
135	}
136
137	ext2fs_free(new_fs);
138	close(fd);
139
140	return 0;
141}
142