online.c revision 200569608fc6e33f6546c17999f14fb5dbb0b9b5 
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 "config.h"
13#include "resize2fs.h"
14#ifdef HAVE_SYS_IOCTL_H
15#include <sys/ioctl.h>
16#endif
17#include <sys/stat.h>
18#include <fcntl.h>
19
20extern char *program_name;
21
22#define MAX_32_NUM ((((unsigned long long) 1) << 32) - 1)
23
24errcode_t online_resize_fs(ext2_filsys fs, const char *mtpt,
25			   blk64_t *new_size, int flags EXT2FS_ATTR((unused)))
26{
27#ifdef __linux__
28	struct ext2_new_group_input input;
29	struct ext4_new_group_input input64;
30	struct ext2_super_block *sb = fs->super;
31	unsigned long		new_desc_blocks;
32	ext2_filsys 		new_fs;
33	errcode_t 		retval;
34	double			percent;
35	dgrp_t			i;
36	blk_t			size;
37	int			fd, overhead;
38	int			use_old_ioctl = 1;
39
40	printf(_("Filesystem at %s is mounted on %s; "
41		 "on-line resizing required\n"), fs->device_name, mtpt);
42
43	if (*new_size < ext2fs_blocks_count(sb)) {
44		com_err(program_name, 0, _("On-line shrinking not supported"));
45		exit(1);
46	}
47
48	/*
49	 * If the number of descriptor blocks is going to increase,
50	 * the on-line resizing inode must be present.
51	 */
52	new_desc_blocks = ext2fs_div_ceil(
53		ext2fs_div64_ceil(*new_size -
54				  fs->super->s_first_data_block,
55				  EXT2_BLOCKS_PER_GROUP(fs->super)),
56		EXT2_DESC_PER_BLOCK(fs->super));
57	printf("old_desc_blocks = %lu, new_desc_blocks = %lu\n",
58	       fs->desc_blocks, new_desc_blocks);
59	if (!(fs->super->s_feature_compat &
60	      EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
61	    new_desc_blocks != fs->desc_blocks) {
62		com_err(program_name, 0,
63			_("Filesystem does not support online resizing"));
64		exit(1);
65	}
66
67	fd = open(mtpt, O_RDONLY);
68	if (fd < 0) {
69		com_err(program_name, errno,
70			_("while trying to open mountpoint %s"), mtpt);
71		exit(1);
72	}
73
74	if (ioctl(fd, EXT4_IOC_RESIZE_FS, new_size)) {
75		if (errno != EINVAL) {
76			if (errno == EPERM)
77				com_err(program_name, 0,
78				_("Permission denied to resize filesystem"));
79			else
80				com_err(program_name, errno,
81				_("While checking for on-line resizing "
82				  "support"));
83			exit(1);
84		}
85	} else {
86		close(fd);
87		return 0;
88	}
89
90	if ((ext2fs_blocks_count(sb) > MAX_32_NUM) ||
91	    (*new_size > MAX_32_NUM)) {
92		com_err(program_name, 0,
93			_("Kernel does not resizing a file system this large"));
94		exit(1);
95	}
96	size = ext2fs_blocks_count(sb);
97
98	if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
99		if (errno == EPERM)
100			com_err(program_name, 0,
101				_("Permission denied to resize filesystem"));
102		else if (errno == ENOTTY)
103			com_err(program_name, 0,
104			_("Kernel does not support online resizing"));
105		else
106			com_err(program_name, errno,
107			_("While checking for on-line resizing support"));
108		exit(1);
109	}
110
111	percent = (ext2fs_r_blocks_count(sb) * 100.0) /
112		ext2fs_blocks_count(sb);
113
114	retval = ext2fs_read_bitmaps(fs);
115	if (retval)
116		return retval;
117
118	retval = ext2fs_dup_handle(fs, &new_fs);
119	if (retval)
120		return retval;
121
122	/* The current method of adding one block group at a time to a
123	 * mounted filesystem means it is impossible to accomodate the
124	 * flex_bg allocation method of placing the metadata together
125	 * in a single block group.  For now we "fix" this issue by
126	 * using the traditional layout for new block groups, where
127	 * each block group is self-contained and contains its own
128	 * bitmap blocks and inode tables.  This means we don't get
129	 * the layout advantages of flex_bg in the new block groups,
130	 * but at least it allows on-line resizing to function.
131	 */
132	new_fs->super->s_feature_incompat &= ~EXT4_FEATURE_INCOMPAT_FLEX_BG;
133	retval = adjust_fs_info(new_fs, fs, 0, *new_size);
134	if (retval)
135		return retval;
136
137	printf(_("Performing an on-line resize of %s to %llu (%dk) blocks.\n"),
138	       fs->device_name, *new_size, fs->blocksize / 1024);
139
140	size = fs->group_desc_count * sb->s_blocks_per_group +
141		sb->s_first_data_block;
142	if (size > *new_size)
143		size = *new_size;
144
145	if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
146		com_err(program_name, errno,
147			_("While trying to extend the last group"));
148		exit(1);
149	}
150
151	for (i = fs->group_desc_count;
152	     i < new_fs->group_desc_count; i++) {
153
154		overhead = (int) (2 + new_fs->inode_blocks_per_group);
155
156		if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1))
157			overhead += 1 + new_fs->desc_blocks +
158				new_fs->super->s_reserved_gdt_blocks;
159
160		input.group = i;
161		input.block_bitmap = ext2fs_block_bitmap_loc(new_fs, i);
162		input.inode_bitmap = ext2fs_inode_bitmap_loc(new_fs, i);
163		input.inode_table = ext2fs_inode_table_loc(new_fs, i);
164		input.blocks_count = ext2fs_group_blocks_count(new_fs, i);
165		input.reserved_blocks = (blk_t) (percent * input.blocks_count
166						 / 100.0);
167
168#if 0
169		printf("new block bitmap is at 0x%04x\n", input.block_bitmap);
170		printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap);
171		printf("new inode table is at 0x%04x-0x%04x\n",
172		       input.inode_table,
173		       input.inode_table + new_fs->inode_blocks_per_group-1);
174		printf("new group has %u blocks\n", input.blocks_count);
175		printf("new group will reserve %d blocks\n",
176		       input.reserved_blocks);
177		printf("new group has %d free blocks\n",
178		       ext2fs_bg_free_blocks_count(new_fs, i),
179		printf("new group has %d free inodes (%d blocks)\n",
180		       ext2fs_bg_free_inodes_count(new_fs, i),
181		       new_fs->inode_blocks_per_group);
182		printf("Adding group #%d\n", input.group);
183#endif
184
185		if (use_old_ioctl &&
186		    ioctl(fd, EXT2_IOC_GROUP_ADD, &input) == 0)
187			continue;
188		else
189			use_old_ioctl = 0;
190
191		input64.group = input.group;
192		input64.block_bitmap = input.block_bitmap;
193		input64.inode_bitmap = input.inode_bitmap;
194		input64.inode_table = input.inode_table;
195		input64.blocks_count = input.blocks_count;
196		input64.reserved_blocks = input.reserved_blocks;
197		input64.unused = input.unused;
198
199		if (ioctl(fd, EXT4_IOC_GROUP_ADD, &input64) < 0) {
200			com_err(program_name, errno,
201				_("While trying to add group #%d"),
202				input.group);
203			exit(1);
204		}
205	}
206
207	ext2fs_free(new_fs);
208	close(fd);
209
210	return 0;
211#else
212	printf(_("Filesystem at %s is mounted on %s, and on-line resizing is "
213		 "not supported on this system.\n"), fs->device_name, mtpt);
214	exit(1);
215#endif
216}
217