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, (unsigned long long) *new_size,
222 fs->blocksize / 1024);
223
224 size = fs->group_desc_count * sb->s_blocks_per_group +
225 sb->s_first_data_block;
226 if (size > *new_size)
227 size = *new_size;
228
229 if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
230 com_err(program_name, errno,
231 _("While trying to extend the last group"));
232 exit(1);
233 }
234
235 for (i = fs->group_desc_count;
236 i < new_fs->group_desc_count; i++) {
237 input.group = i;
238 input.block_bitmap = ext2fs_block_bitmap_loc(new_fs, i);
239 input.inode_bitmap = ext2fs_inode_bitmap_loc(new_fs, i);
240 input.inode_table = ext2fs_inode_table_loc(new_fs, i);
241 input.blocks_count = ext2fs_group_blocks_count(new_fs, i);
242 input.reserved_blocks = (blk_t) (percent * input.blocks_count
243 / 100.0);
244
245 #if 0
246 printf("new block bitmap is at 0x%04x\n", input.block_bitmap);
247 printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap);
248 printf("new inode table is at 0x%04x-0x%04x\n",
249 input.inode_table,
250 input.inode_table + new_fs->inode_blocks_per_group-1);
251 printf("new group has %u blocks\n", input.blocks_count);
252 printf("new group will reserve %d blocks\n",
253 input.reserved_blocks);
254 printf("new group has %d free blocks\n",
255 ext2fs_bg_free_blocks_count(new_fs, i),
256 printf("new group has %d free inodes (%d blocks)\n",
257 ext2fs_bg_free_inodes_count(new_fs, i),
258 new_fs->inode_blocks_per_group);
259 printf("Adding group #%d\n", input.group);
260 #endif
261
262 if (use_old_ioctl &&
263 ioctl(fd, EXT2_IOC_GROUP_ADD, &input) == 0)
264 continue;
265 else
266 use_old_ioctl = 0;
267
268 input64.group = input.group;
269 input64.block_bitmap = input.block_bitmap;
270 input64.inode_bitmap = input.inode_bitmap;
271 input64.inode_table = input.inode_table;
272 input64.blocks_count = input.blocks_count;
273 input64.reserved_blocks = input.reserved_blocks;
274 input64.unused = input.unused;
275
276 if (ioctl(fd, EXT4_IOC_GROUP_ADD, &input64) < 0) {
277 com_err(program_name, errno,
278 _("While trying to add group #%d"),
279 input.group);
280 exit(1);
281 }
282 }
283
284 ext2fs_free(new_fs);
285 close(fd);
286
287 return 0;
288 #else
289 printf(_("Filesystem at %s is mounted on %s, and on-line resizing is "
290 "not supported on this system.\n"), fs->device_name, mtpt);
291 exit(1);
292 #endif
293 }
294