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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 
19 extern char *program_name;
20 
online_resize_fs(ext2_filsys fs,const char * mtpt,blk_t * new_size,int flags EXT2FS_ATTR ((unused)))21 errcode_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 ext2_super_block *sb = fs->super;
27 	unsigned long		new_desc_blocks;
28 	ext2_filsys 		new_fs;
29 	errcode_t 		retval;
30 	dgrp_t			i;
31 	blk_t			size;
32 	int			fd, r_frac, overhead;
33 
34 	printf(_("Filesystem at %s is mounted on %s; "
35 		 "on-line resizing required\n"), fs->device_name, mtpt);
36 
37 	if (*new_size < sb->s_blocks_count) {
38 		printf(_("On-line shrinking from %u to %u not supported.\n"),
39 		       sb->s_blocks_count, *new_size);
40 		exit(1);
41 	}
42 
43 	/*
44 	 * If the number of descriptor blocks is going to increase,
45 	 * the on-line resizing inode must be present.
46 	 */
47 	new_desc_blocks = ext2fs_div_ceil(
48 		ext2fs_div_ceil(*new_size -
49 				fs->super->s_first_data_block,
50 				EXT2_BLOCKS_PER_GROUP(fs->super)),
51 		EXT2_DESC_PER_BLOCK(fs->super));
52 	printf("old desc_blocks = %lu, new_desc_blocks = %lu\n",
53 	       fs->desc_blocks, new_desc_blocks);
54 	if (!(fs->super->s_feature_compat &
55 	      EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
56 	    new_desc_blocks != fs->desc_blocks) {
57 		com_err(program_name, 0,
58 			_("Filesystem does not support online resizing"));
59 		exit(1);
60 	}
61 
62 	fd = open(mtpt, O_RDONLY);
63 	if (fd < 0) {
64 		com_err(program_name, errno,
65 			_("while trying to open mountpoint %s"), mtpt);
66 		exit(1);
67 	}
68 
69 	size=sb->s_blocks_count;
70 	if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
71 		if (errno == EPERM)
72 			com_err(program_name, 0,
73 				_("Permission denied to resize filesystem"));
74 		else if (errno == ENOTTY)
75 			com_err(program_name, 0,
76 			_("Kernel does not support online resizing"));
77 		else
78 			com_err(program_name, errno,
79 			_("While checking for on-line resizing support"));
80 		exit(1);
81 	}
82 
83 	r_frac = ext2fs_div_ceil(100 * sb->s_r_blocks_count, sb->s_blocks_count);
84 
85 	retval = ext2fs_read_bitmaps(fs);
86 	if (retval)
87 		return retval;
88 
89 	retval = ext2fs_dup_handle(fs, &new_fs);
90 	if (retval)
91 		return retval;
92 
93 	retval = adjust_fs_info(new_fs, fs, *new_size);
94 	if (retval)
95 		return retval;
96 
97 	printf(_("Performing an on-line resize of %s to %u (%dk) blocks.\n"),
98 	       fs->device_name, *new_size, fs->blocksize / 1024);
99 
100 	size = fs->group_desc_count * sb->s_blocks_per_group +
101 		sb->s_first_data_block;
102 	if (size > *new_size)
103 		size = *new_size;
104 
105 	if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
106 		com_err(program_name, errno,
107 			_("While trying to extend the last group"));
108 		exit(1);
109 	}
110 
111 	for (i = fs->group_desc_count;
112 	     i < new_fs->group_desc_count; i++) {
113 
114 		overhead = (int) (2 + new_fs->inode_blocks_per_group);
115 
116 		if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1))
117 			overhead += 1 + new_fs->desc_blocks +
118 				new_fs->super->s_reserved_gdt_blocks;
119 
120 		input.group = i;
121 		input.block_bitmap = new_fs->group_desc[i].bg_block_bitmap;
122 		input.inode_bitmap = new_fs->group_desc[i].bg_inode_bitmap;
123 		input.inode_table = new_fs->group_desc[i].bg_inode_table;
124 		input.blocks_count = sb->s_blocks_per_group;
125 		if (i == new_fs->group_desc_count-1) {
126 			input.blocks_count = new_fs->super->s_blocks_count -
127 				sb->s_first_data_block -
128 				(i * sb->s_blocks_per_group);
129 		}
130 		input.reserved_blocks = e2p_percent(r_frac,
131 						    input.blocks_count);
132 
133 #if 0
134 		printf("new block bitmap is at 0x%04x\n", input.block_bitmap);
135 		printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap);
136 		printf("new inode table is at 0x%04x-0x%04x\n",
137 		       input.inode_table,
138 		       input.inode_table + new_fs->inode_blocks_per_group-1);
139 		printf("new group has %u blocks\n", input.blocks_count);
140 		printf("new group will reserve %d blocks\n",
141 		       input.reserved_blocks);
142 		printf("new group has %d free blocks\n",
143 		       new_fs->group_desc[i].bg_free_blocks_count);
144 		printf("new group has %d free inodes (%d blocks)\n",
145 		       new_fs->group_desc[i].bg_free_inodes_count,
146 		       new_fs->inode_blocks_per_group);
147 		printf("Adding group #%d\n", input.group);
148 #endif
149 
150 		if (ioctl(fd, EXT2_IOC_GROUP_ADD, &input) < 0) {
151 			com_err(program_name, errno,
152 				_("While trying to add group #%d"),
153 				input.group);
154 			exit(1);
155 		}
156 	}
157 
158 	ext2fs_free(new_fs);
159 	close(fd);
160 
161 	return 0;
162 #else
163 	printf(_("Filesystem at %s is mounted on %s, and on-line resizing is"
164 		 "not supported on this system.\n"), fs->device_name, mtpt);
165 	exit(1);
166 #endif
167 }
168