online.c revision df9c01b1449ccbaa9283486f0f6a50085043036b 
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 EXT2FS_ATTR((unused)))
23{
24#ifdef __linux__
25	struct ext2_new_group_input input;
26	struct ext4_new_group_input input64;
27	struct ext2_super_block *sb = fs->super;
28	unsigned long		new_desc_blocks;
29	ext2_filsys 		new_fs;
30	errcode_t 		retval;
31	double			percent;
32	dgrp_t			i;
33	blk_t			size;
34	int			fd, overhead;
35	int			use_old_ioctl = 1;
36
37	printf(_("Filesystem at %s is mounted on %s; "
38		 "on-line resizing required\n"), fs->device_name, mtpt);
39
40	if (*new_size < sb->s_blocks_count) {
41		printf(_("On-line shrinking from %u to %u not supported.\n"),
42		       sb->s_blocks_count, *new_size);
43		exit(1);
44	}
45
46	/*
47	 * If the number of descriptor blocks is going to increase,
48	 * the on-line resizing inode must be present.
49	 */
50	new_desc_blocks = ext2fs_div_ceil(
51		ext2fs_div_ceil(*new_size -
52				fs->super->s_first_data_block,
53				EXT2_BLOCKS_PER_GROUP(fs->super)),
54		EXT2_DESC_PER_BLOCK(fs->super));
55	printf("old desc_blocks = %lu, new_desc_blocks = %lu\n",
56	       fs->desc_blocks, new_desc_blocks);
57	if (!(fs->super->s_feature_compat &
58	      EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
59	    new_desc_blocks != fs->desc_blocks) {
60		com_err(program_name, 0,
61			_("Filesystem does not support online resizing"));
62		exit(1);
63	}
64
65	fd = open(mtpt, O_RDONLY);
66	if (fd < 0) {
67		com_err(program_name, errno,
68			_("while trying to open mountpoint %s"), mtpt);
69		exit(1);
70	}
71
72	size=sb->s_blocks_count;
73	if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
74		if (errno == EPERM)
75			com_err(program_name, 0,
76				_("Permission denied to resize filesystem"));
77		else if (errno == ENOTTY)
78			com_err(program_name, 0,
79			_("Kernel does not support online resizing"));
80		else
81			com_err(program_name, errno,
82			_("While checking for on-line resizing support"));
83		exit(1);
84	}
85
86	percent = (sb->s_r_blocks_count * 100.0) / sb->s_blocks_count;
87
88	retval = ext2fs_read_bitmaps(fs);
89	if (retval)
90		return retval;
91
92	retval = ext2fs_dup_handle(fs, &new_fs);
93	if (retval)
94		return retval;
95
96	retval = adjust_fs_info(new_fs, fs, *new_size);
97	if (retval)
98		return retval;
99
100	printf(_("Performing an on-line resize of %s to %u (%dk) blocks.\n"),
101	       fs->device_name, *new_size, fs->blocksize / 1024);
102
103	size = fs->group_desc_count * sb->s_blocks_per_group +
104		sb->s_first_data_block;
105	if (size > *new_size)
106		size = *new_size;
107
108	if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
109		com_err(program_name, errno,
110			_("While trying to extend the last group"));
111		exit(1);
112	}
113
114	for (i = fs->group_desc_count;
115	     i < new_fs->group_desc_count; i++) {
116
117		overhead = (int) (2 + new_fs->inode_blocks_per_group);
118
119		if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1))
120			overhead += 1 + new_fs->desc_blocks +
121				new_fs->super->s_reserved_gdt_blocks;
122
123		input.group = i;
124		input.block_bitmap = new_fs->group_desc[i].bg_block_bitmap;
125		input.inode_bitmap = new_fs->group_desc[i].bg_inode_bitmap;
126		input.inode_table = new_fs->group_desc[i].bg_inode_table;
127		input.blocks_count = sb->s_blocks_per_group;
128		if (i == new_fs->group_desc_count-1) {
129			input.blocks_count = new_fs->super->s_blocks_count -
130				sb->s_first_data_block -
131				(i * sb->s_blocks_per_group);
132		}
133		input.reserved_blocks = (blk_t) (percent * input.blocks_count
134						 / 100.0);
135
136#if 0
137		printf("new block bitmap is at 0x%04x\n", input.block_bitmap);
138		printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap);
139		printf("new inode table is at 0x%04x-0x%04x\n",
140		       input.inode_table,
141		       input.inode_table + new_fs->inode_blocks_per_group-1);
142		printf("new group has %u blocks\n", input.blocks_count);
143		printf("new group will reserve %d blocks\n",
144		       input.reserved_blocks);
145		printf("new group has %d free blocks\n",
146		       new_fs->group_desc[i].bg_free_blocks_count);
147		printf("new group has %d free inodes (%d blocks)\n",
148		       new_fs->group_desc[i].bg_free_inodes_count,
149		       new_fs->inode_blocks_per_group);
150		printf("Adding group #%d\n", input.group);
151#endif
152
153		if (use_old_ioctl &&
154		    ioctl(fd, EXT2_IOC_GROUP_ADD, &input) == 0)
155			continue;
156		else
157			use_old_ioctl = 1;
158
159		input64.group = input.group;
160		input64.block_bitmap = input.block_bitmap;
161		input64.inode_bitmap = input.inode_bitmap;
162		input64.inode_table = input.inode_table;
163		input64.blocks_count = input.blocks_count;
164		input64.reserved_blocks = input.reserved_blocks;
165		input64.unused = input.unused;
166
167		if (ioctl(fd, EXT4_IOC_GROUP_ADD, &input64) < 0) {
168			com_err(program_name, errno,
169				_("While trying to add group #%d"),
170				input.group);
171			exit(1);
172		}
173	}
174
175	ext2fs_free(new_fs);
176	close(fd);
177
178	return 0;
179#else
180	printf(_("Filesystem at %s is mounted on %s, and on-line resizing is "
181		 "not supported on this system.\n"), fs->device_name, mtpt);
182	exit(1);
183#endif
184}
185