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
21 #define MAX_32_NUM ((((unsigned long long) 1) << 32) - 1)
22
23 #ifdef __linux__
parse_version_number(const char * s)24 static int parse_version_number(const char *s)
25 {
26 int major, minor, rev;
27 char *endptr;
28 const char *cp = s;
29
30 if (!s)
31 return 0;
32 major = strtol(cp, &endptr, 10);
33 if (cp == endptr || *endptr != '.')
34 return 0;
35 cp = endptr + 1;
36 minor = strtol(cp, &endptr, 10);
37 if (cp == endptr || *endptr != '.')
38 return 0;
39 cp = endptr + 1;
40 rev = strtol(cp, &endptr, 10);
41 if (cp == endptr)
42 return 0;
43 return ((((major * 256) + minor) * 256) + rev);
44 }
45
46 #define VERSION_CODE(a,b,c) (((a) << 16) + ((b) << 8) + (c))
47
48 #endif
49
online_resize_fs(ext2_filsys fs,const char * mtpt,blk64_t * new_size,int flags EXT2FS_ATTR ((unused)))50 errcode_t online_resize_fs(ext2_filsys fs, const char *mtpt,
51 blk64_t *new_size, int flags EXT2FS_ATTR((unused)))
52 {
53 #ifdef __linux__
54 struct ext2_new_group_input input;
55 struct ext4_new_group_input input64;
56 struct ext2_super_block *sb = fs->super;
57 unsigned long new_desc_blocks;
58 ext2_filsys new_fs;
59 errcode_t retval;
60 double percent;
61 dgrp_t i;
62 blk_t size;
63 int fd, overhead;
64 int use_old_ioctl = 1;
65 int no_meta_bg_resize = 0;
66 int no_resize_ioctl = 0;
67
68 if (getenv("RESIZE2FS_KERNEL_VERSION")) {
69 char *version_to_emulate = getenv("RESIZE2FS_KERNEL_VERSION");
70 int kvers = parse_version_number(version_to_emulate);
71
72 if (kvers < VERSION_CODE(3, 7, 0))
73 no_meta_bg_resize = 1;
74 if (kvers < VERSION_CODE(3, 3, 0))
75 no_resize_ioctl = 1;
76 }
77
78 printf(_("Filesystem at %s is mounted on %s; "
79 "on-line resizing required\n"), fs->device_name, mtpt);
80
81 if (*new_size < ext2fs_blocks_count(sb)) {
82 com_err(program_name, 0, _("On-line shrinking not supported"));
83 exit(1);
84 }
85
86 /*
87 * If the number of descriptor blocks is going to increase,
88 * the on-line resizing inode must be present.
89 */
90 new_desc_blocks = ext2fs_div_ceil(
91 ext2fs_div64_ceil(*new_size -
92 fs->super->s_first_data_block,
93 EXT2_BLOCKS_PER_GROUP(fs->super)),
94 EXT2_DESC_PER_BLOCK(fs->super));
95 printf("old_desc_blocks = %lu, new_desc_blocks = %lu\n",
96 fs->desc_blocks, new_desc_blocks);
97
98 /*
99 * Do error checking to make sure the resize will be successful.
100 */
101 if ((access("/sys/fs/ext4/features/meta_bg_resize", R_OK) != 0) ||
102 no_meta_bg_resize) {
103 if (!EXT2_HAS_COMPAT_FEATURE(fs->super,
104 EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
105 (new_desc_blocks != fs->desc_blocks)) {
106 com_err(program_name, 0,
107 _("Filesystem does not support online resizing"));
108 exit(1);
109 }
110
111 if (EXT2_HAS_COMPAT_FEATURE(fs->super,
112 EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
113 new_desc_blocks > (fs->desc_blocks +
114 fs->super->s_reserved_gdt_blocks)) {
115 com_err(program_name, 0,
116 _("Not enough reserved gdt blocks for resizing"));
117 exit(1);
118 }
119
120 if ((ext2fs_blocks_count(sb) > MAX_32_NUM) ||
121 (*new_size > MAX_32_NUM)) {
122 com_err(program_name, 0,
123 _("Kernel does not support resizing a file system this large"));
124 exit(1);
125 }
126 }
127
128 fd = open(mtpt, O_RDONLY);
129 if (fd < 0) {
130 com_err(program_name, errno,
131 _("while trying to open mountpoint %s"), mtpt);
132 exit(1);
133 }
134
135 if (no_resize_ioctl) {
136 printf(_("Old resize interface requested.\n"));
137 } else if (ioctl(fd, EXT4_IOC_RESIZE_FS, new_size)) {
138 /*
139 * If kernel does not support EXT4_IOC_RESIZE_FS, use the
140 * old online resize. Note that the old approach does not
141 * handle >32 bit file systems
142 *
143 * Sigh, if we are running a 32-bit binary on a 64-bit
144 * kernel (which happens all the time on the MIPS
145 * architecture in Debian, but can happen on other CPU
146 * architectures as well) we will get EINVAL returned
147 * when an ioctl doesn't exist, at least up to Linux
148 * 3.1. See compat_sys_ioctl() in fs/compat_ioctl.c
149 * in the kernel sources. This is probably a kernel
150 * bug, but work around it here.
151 */
152 if ((errno != ENOTTY) && (errno != EINVAL)) {
153 if (errno == EPERM)
154 com_err(program_name, 0,
155 _("Permission denied to resize filesystem"));
156 else
157 com_err(program_name, errno,
158 _("While checking for on-line resizing "
159 "support"));
160 exit(1);
161 }
162 } else {
163 close(fd);
164 return 0;
165 }
166
167 size = ext2fs_blocks_count(sb);
168
169 if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
170 if (errno == EPERM)
171 com_err(program_name, 0,
172 _("Permission denied to resize filesystem"));
173 else if (errno == ENOTTY)
174 com_err(program_name, 0,
175 _("Kernel does not support online resizing"));
176 else
177 com_err(program_name, errno,
178 _("While checking for on-line resizing support"));
179 exit(1);
180 }
181
182 percent = (ext2fs_r_blocks_count(sb) * 100.0) /
183 ext2fs_blocks_count(sb);
184
185 retval = ext2fs_read_bitmaps(fs);
186 if (retval) {
187 close(fd);
188 return retval;
189 }
190
191 retval = ext2fs_dup_handle(fs, &new_fs);
192 if (retval) {
193 close(fd);
194 return retval;
195 }
196
197 /* The current method of adding one block group at a time to a
198 * mounted filesystem means it is impossible to accomodate the
199 * flex_bg allocation method of placing the metadata together
200 * in a single block group. For now we "fix" this issue by
201 * using the traditional layout for new block groups, where
202 * each block group is self-contained and contains its own
203 * bitmap blocks and inode tables. This means we don't get
204 * the layout advantages of flex_bg in the new block groups,
205 * but at least it allows on-line resizing to function.
206 */
207 new_fs->super->s_feature_incompat &= ~EXT4_FEATURE_INCOMPAT_FLEX_BG;
208 retval = adjust_fs_info(new_fs, fs, 0, *new_size);
209 if (retval) {
210 close(fd);
211 return retval;
212 }
213
214 printf(_("Performing an on-line resize of %s to %llu (%dk) blocks.\n"),
215 fs->device_name, *new_size, fs->blocksize / 1024);
216
217 size = fs->group_desc_count * sb->s_blocks_per_group +
218 sb->s_first_data_block;
219 if (size > *new_size)
220 size = *new_size;
221
222 if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
223 com_err(program_name, errno,
224 _("While trying to extend the last group"));
225 exit(1);
226 }
227
228 for (i = fs->group_desc_count;
229 i < new_fs->group_desc_count; i++) {
230
231 overhead = (int) (2 + new_fs->inode_blocks_per_group);
232
233 if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1))
234 overhead += 1 + new_fs->desc_blocks +
235 new_fs->super->s_reserved_gdt_blocks;
236
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