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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 "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 
20 extern char *program_name;
21 
22 #define MAX_32_NUM ((((unsigned long long) 1) << 32) - 1)
23 
24 #ifdef __linux__
parse_version_number(const char * s)25 static int parse_version_number(const char *s)
26 {
27 	int	major, minor, rev;
28 	char	*endptr;
29 	const char *cp = s;
30 
31 	if (!s)
32 		return 0;
33 	major = strtol(cp, &endptr, 10);
34 	if (cp == endptr || *endptr != '.')
35 		return 0;
36 	cp = endptr + 1;
37 	minor = strtol(cp, &endptr, 10);
38 	if (cp == endptr || *endptr != '.')
39 		return 0;
40 	cp = endptr + 1;
41 	rev = strtol(cp, &endptr, 10);
42 	if (cp == endptr)
43 		return 0;
44 	return ((((major * 256) + minor) * 256) + rev);
45 }
46 
47 #define VERSION_CODE(a,b,c) (((a) << 16) + ((b) << 8) + (c))
48 
49 #endif
50 
online_resize_fs(ext2_filsys fs,const char * mtpt,blk64_t * new_size,int flags EXT2FS_ATTR ((unused)))51 errcode_t online_resize_fs(ext2_filsys fs, const char *mtpt,
52 			   blk64_t *new_size, int flags EXT2FS_ATTR((unused)))
53 {
54 #ifdef __linux__
55 	struct ext2_new_group_input input;
56 	struct ext4_new_group_input input64;
57 	struct ext2_super_block *sb = fs->super;
58 	unsigned long		new_desc_blocks;
59 	ext2_filsys 		new_fs;
60 	errcode_t 		retval;
61 	double			percent;
62 	dgrp_t			i;
63 	blk_t			size;
64 	int			fd;
65 	int			use_old_ioctl = 1;
66 	int			no_meta_bg_resize = 0;
67 	int			no_resize_ioctl = 0;
68 
69 	if (getenv("RESIZE2FS_KERNEL_VERSION")) {
70 		char *version_to_emulate = getenv("RESIZE2FS_KERNEL_VERSION");
71 		int kvers = parse_version_number(version_to_emulate);
72 
73 		if (kvers < VERSION_CODE(3, 7, 0))
74 			no_meta_bg_resize = 1;
75 		if (kvers < VERSION_CODE(3, 3, 0))
76 			no_resize_ioctl = 1;
77 	}
78 
79 	if (ext2fs_has_feature_sparse_super2(fs->super) &&
80 	    (access("/sys/fs/ext4/features/sparse_super2", R_OK) != 0)) {
81 		com_err(program_name, 0, _("kernel does not support online "
82 					   "resize with sparse_super2"));
83 		exit(1);
84 	}
85 
86 	printf(_("Filesystem at %s is mounted on %s; "
87 		 "on-line resizing required\n"), fs->device_name, mtpt);
88 
89 	if (*new_size < ext2fs_blocks_count(sb)) {
90 		com_err(program_name, 0, _("On-line shrinking not supported"));
91 		exit(1);
92 	}
93 
94 	/*
95 	 * If the number of descriptor blocks is going to increase,
96 	 * the on-line resizing inode must be present.
97 	 */
98 	new_desc_blocks = ext2fs_div_ceil(
99 		ext2fs_div64_ceil(*new_size -
100 				  fs->super->s_first_data_block,
101 				  EXT2_BLOCKS_PER_GROUP(fs->super)),
102 		EXT2_DESC_PER_BLOCK(fs->super));
103 	printf("old_desc_blocks = %lu, new_desc_blocks = %lu\n",
104 	       fs->desc_blocks, new_desc_blocks);
105 
106 	/*
107 	 * Do error checking to make sure the resize will be successful.
108 	 */
109 	if ((access("/sys/fs/ext4/features/meta_bg_resize", R_OK) != 0) ||
110 	    no_meta_bg_resize) {
111 		if (!ext2fs_has_feature_resize_inode(fs->super) &&
112 		    (new_desc_blocks != fs->desc_blocks)) {
113 			com_err(program_name, 0,
114 				_("Filesystem does not support online resizing"));
115 			exit(1);
116 		}
117 
118 		if (ext2fs_has_feature_resize_inode(fs->super) &&
119 		    new_desc_blocks > (fs->desc_blocks +
120 				       fs->super->s_reserved_gdt_blocks)) {
121 			com_err(program_name, 0,
122 				_("Not enough reserved gdt blocks for resizing"));
123 			exit(1);
124 		}
125 
126 		if ((ext2fs_blocks_count(sb) > MAX_32_NUM) ||
127 		    (*new_size > MAX_32_NUM)) {
128 			com_err(program_name, 0,
129 				_("Kernel does not support resizing a file system this large"));
130 			exit(1);
131 		}
132 	}
133 
134 	fd = open(mtpt, O_RDONLY);
135 	if (fd < 0) {
136 		com_err(program_name, errno,
137 			_("while trying to open mountpoint %s"), mtpt);
138 		exit(1);
139 	}
140 
141 	if (no_resize_ioctl) {
142 		printf(_("Old resize interface requested.\n"));
143 	} else if (ioctl(fd, EXT4_IOC_RESIZE_FS, new_size)) {
144 		/*
145 		 * If kernel does not support EXT4_IOC_RESIZE_FS, use the
146 		 * old online resize. Note that the old approach does not
147 		 * handle >32 bit file systems
148 		 *
149 		 * Sigh, if we are running a 32-bit binary on a 64-bit
150 		 * kernel (which happens all the time on the MIPS
151 		 * architecture in Debian, but can happen on other CPU
152 		 * architectures as well) we will get EINVAL returned
153 		 * when an ioctl doesn't exist, at least up to Linux
154 		 * 3.1.  See compat_sys_ioctl() in fs/compat_ioctl.c
155 		 * in the kernel sources.  This is probably a kernel
156 		 * bug, but work around it here.
157 		 */
158 		if ((errno != ENOTTY) && (errno != EINVAL)) {
159 			if (errno == EPERM)
160 				com_err(program_name, 0,
161 				_("Permission denied to resize filesystem"));
162 			else
163 				com_err(program_name, errno,
164 				_("While checking for on-line resizing "
165 				  "support"));
166 			exit(1);
167 		}
168 	} else {
169 		close(fd);
170 		return 0;
171 	}
172 
173 	size = ext2fs_blocks_count(sb);
174 
175 	if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
176 		if (errno == EPERM)
177 			com_err(program_name, 0,
178 				_("Permission denied to resize filesystem"));
179 		else if (errno == ENOTTY)
180 			com_err(program_name, 0,
181 			_("Kernel does not support online resizing"));
182 		else
183 			com_err(program_name, errno,
184 			_("While checking for on-line resizing support"));
185 		exit(1);
186 	}
187 
188 	percent = (ext2fs_r_blocks_count(sb) * 100.0) /
189 		ext2fs_blocks_count(sb);
190 
191 	retval = ext2fs_read_bitmaps(fs);
192 	if (retval) {
193 		close(fd);
194 		return retval;
195 	}
196 
197 	retval = ext2fs_dup_handle(fs, &new_fs);
198 	if (retval) {
199 		close(fd);
200 		return retval;
201 	}
202 
203 	/* The current method of adding one block group at a time to a
204 	 * mounted filesystem means it is impossible to accommodate the
205 	 * flex_bg allocation method of placing the metadata together
206 	 * in a single block group.  For now we "fix" this issue by
207 	 * using the traditional layout for new block groups, where
208 	 * each block group is self-contained and contains its own
209 	 * bitmap blocks and inode tables.  This means we don't get
210 	 * the layout advantages of flex_bg in the new block groups,
211 	 * but at least it allows on-line resizing to function.
212 	 */
213 	ext2fs_clear_feature_flex_bg(new_fs->super);
214 	retval = adjust_fs_info(new_fs, fs, 0, *new_size);
215 	if (retval) {
216 		close(fd);
217 		return retval;
218 	}
219 
220 	printf(_("Performing an on-line resize of %s to %llu (%dk) blocks.\n"),
221 	       fs->device_name, *new_size, fs->blocksize / 1024);
222 
223 	size = fs->group_desc_count * sb->s_blocks_per_group +
224 		sb->s_first_data_block;
225 	if (size > *new_size)
226 		size = *new_size;
227 
228 	if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
229 		com_err(program_name, errno,
230 			_("While trying to extend the last group"));
231 		exit(1);
232 	}
233 
234 	for (i = fs->group_desc_count;
235 	     i < new_fs->group_desc_count; i++) {
236 		input.group = i;
237 		input.block_bitmap = ext2fs_block_bitmap_loc(new_fs, i);
238 		input.inode_bitmap = ext2fs_inode_bitmap_loc(new_fs, i);
239 		input.inode_table = ext2fs_inode_table_loc(new_fs, i);
240 		input.blocks_count = ext2fs_group_blocks_count(new_fs, i);
241 		input.reserved_blocks = (blk_t) (percent * input.blocks_count
242 						 / 100.0);
243 
244 #if 0
245 		printf("new block bitmap is at 0x%04x\n", input.block_bitmap);
246 		printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap);
247 		printf("new inode table is at 0x%04x-0x%04x\n",
248 		       input.inode_table,
249 		       input.inode_table + new_fs->inode_blocks_per_group-1);
250 		printf("new group has %u blocks\n", input.blocks_count);
251 		printf("new group will reserve %d blocks\n",
252 		       input.reserved_blocks);
253 		printf("new group has %d free blocks\n",
254 		       ext2fs_bg_free_blocks_count(new_fs, i),
255 		printf("new group has %d free inodes (%d blocks)\n",
256 		       ext2fs_bg_free_inodes_count(new_fs, i),
257 		       new_fs->inode_blocks_per_group);
258 		printf("Adding group #%d\n", input.group);
259 #endif
260 
261 		if (use_old_ioctl &&
262 		    ioctl(fd, EXT2_IOC_GROUP_ADD, &input) == 0)
263 			continue;
264 		else
265 			use_old_ioctl = 0;
266 
267 		input64.group = input.group;
268 		input64.block_bitmap = input.block_bitmap;
269 		input64.inode_bitmap = input.inode_bitmap;
270 		input64.inode_table = input.inode_table;
271 		input64.blocks_count = input.blocks_count;
272 		input64.reserved_blocks = input.reserved_blocks;
273 		input64.unused = input.unused;
274 
275 		if (ioctl(fd, EXT4_IOC_GROUP_ADD, &input64) < 0) {
276 			com_err(program_name, errno,
277 				_("While trying to add group #%d"),
278 				input.group);
279 			exit(1);
280 		}
281 	}
282 
283 	ext2fs_free(new_fs);
284 	close(fd);
285 
286 	return 0;
287 #else
288 	printf(_("Filesystem at %s is mounted on %s, and on-line resizing is "
289 		 "not supported on this system.\n"), fs->device_name, mtpt);
290 	exit(1);
291 #endif
292 }
293