Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/ext3/resize.c | |
3 | * | |
4 | * Support for resizing an ext3 filesystem while it is mounted. | |
5 | * | |
6 | * Copyright (C) 2001, 2002 Andreas Dilger <adilger@clusterfs.com> | |
7 | * | |
8 | * This could probably be made into a module, because it is not often in use. | |
9 | */ | |
10 | ||
1da177e4 LT |
11 | |
12 | #define EXT3FS_DEBUG | |
13 | ||
1da177e4 LT |
14 | #include <linux/ext3_jbd.h> |
15 | ||
16 | #include <linux/errno.h> | |
17 | #include <linux/slab.h> | |
18 | ||
19 | ||
20 | #define outside(b, first, last) ((b) < (first) || (b) >= (last)) | |
21 | #define inside(b, first, last) ((b) >= (first) && (b) < (last)) | |
22 | ||
23 | static int verify_group_input(struct super_block *sb, | |
24 | struct ext3_new_group_data *input) | |
25 | { | |
26 | struct ext3_sb_info *sbi = EXT3_SB(sb); | |
27 | struct ext3_super_block *es = sbi->s_es; | |
1c2bf374 MC |
28 | ext3_fsblk_t start = le32_to_cpu(es->s_blocks_count); |
29 | ext3_fsblk_t end = start + input->blocks_count; | |
1da177e4 | 30 | unsigned group = input->group; |
1c2bf374 | 31 | ext3_fsblk_t itend = input->inode_table + sbi->s_itb_per_group; |
1da177e4 LT |
32 | unsigned overhead = ext3_bg_has_super(sb, group) ? |
33 | (1 + ext3_bg_num_gdb(sb, group) + | |
34 | le16_to_cpu(es->s_reserved_gdt_blocks)) : 0; | |
1c2bf374 | 35 | ext3_fsblk_t metaend = start + overhead; |
1da177e4 | 36 | struct buffer_head *bh = NULL; |
1c2bf374 | 37 | ext3_grpblk_t free_blocks_count; |
1da177e4 LT |
38 | int err = -EINVAL; |
39 | ||
40 | input->free_blocks_count = free_blocks_count = | |
41 | input->blocks_count - 2 - overhead - sbi->s_itb_per_group; | |
42 | ||
43 | if (test_opt(sb, DEBUG)) | |
44 | printk(KERN_DEBUG "EXT3-fs: adding %s group %u: %u blocks " | |
45 | "(%d free, %u reserved)\n", | |
46 | ext3_bg_has_super(sb, input->group) ? "normal" : | |
47 | "no-super", input->group, input->blocks_count, | |
48 | free_blocks_count, input->reserved_blocks); | |
49 | ||
50 | if (group != sbi->s_groups_count) | |
e05b6b52 | 51 | ext3_warning(sb, __func__, |
1da177e4 LT |
52 | "Cannot add at group %u (only %lu groups)", |
53 | input->group, sbi->s_groups_count); | |
54 | else if ((start - le32_to_cpu(es->s_first_data_block)) % | |
55 | EXT3_BLOCKS_PER_GROUP(sb)) | |
e05b6b52 | 56 | ext3_warning(sb, __func__, "Last group not full"); |
1da177e4 | 57 | else if (input->reserved_blocks > input->blocks_count / 5) |
e05b6b52 | 58 | ext3_warning(sb, __func__, "Reserved blocks too high (%u)", |
1da177e4 LT |
59 | input->reserved_blocks); |
60 | else if (free_blocks_count < 0) | |
e05b6b52 | 61 | ext3_warning(sb, __func__, "Bad blocks count %u", |
1da177e4 LT |
62 | input->blocks_count); |
63 | else if (!(bh = sb_bread(sb, end - 1))) | |
e05b6b52 | 64 | ext3_warning(sb, __func__, |
1c2bf374 | 65 | "Cannot read last block ("E3FSBLK")", |
1da177e4 LT |
66 | end - 1); |
67 | else if (outside(input->block_bitmap, start, end)) | |
e05b6b52 | 68 | ext3_warning(sb, __func__, |
1da177e4 LT |
69 | "Block bitmap not in group (block %u)", |
70 | input->block_bitmap); | |
71 | else if (outside(input->inode_bitmap, start, end)) | |
e05b6b52 | 72 | ext3_warning(sb, __func__, |
1da177e4 LT |
73 | "Inode bitmap not in group (block %u)", |
74 | input->inode_bitmap); | |
75 | else if (outside(input->inode_table, start, end) || | |
76 | outside(itend - 1, start, end)) | |
e05b6b52 | 77 | ext3_warning(sb, __func__, |
1c2bf374 | 78 | "Inode table not in group (blocks %u-"E3FSBLK")", |
1da177e4 LT |
79 | input->inode_table, itend - 1); |
80 | else if (input->inode_bitmap == input->block_bitmap) | |
e05b6b52 | 81 | ext3_warning(sb, __func__, |
1da177e4 LT |
82 | "Block bitmap same as inode bitmap (%u)", |
83 | input->block_bitmap); | |
84 | else if (inside(input->block_bitmap, input->inode_table, itend)) | |
e05b6b52 | 85 | ext3_warning(sb, __func__, |
1c2bf374 | 86 | "Block bitmap (%u) in inode table (%u-"E3FSBLK")", |
1da177e4 LT |
87 | input->block_bitmap, input->inode_table, itend-1); |
88 | else if (inside(input->inode_bitmap, input->inode_table, itend)) | |
e05b6b52 | 89 | ext3_warning(sb, __func__, |
1c2bf374 | 90 | "Inode bitmap (%u) in inode table (%u-"E3FSBLK")", |
1da177e4 LT |
91 | input->inode_bitmap, input->inode_table, itend-1); |
92 | else if (inside(input->block_bitmap, start, metaend)) | |
e05b6b52 | 93 | ext3_warning(sb, __func__, |
1c2bf374 MC |
94 | "Block bitmap (%u) in GDT table" |
95 | " ("E3FSBLK"-"E3FSBLK")", | |
1da177e4 LT |
96 | input->block_bitmap, start, metaend - 1); |
97 | else if (inside(input->inode_bitmap, start, metaend)) | |
e05b6b52 | 98 | ext3_warning(sb, __func__, |
1c2bf374 MC |
99 | "Inode bitmap (%u) in GDT table" |
100 | " ("E3FSBLK"-"E3FSBLK")", | |
1da177e4 LT |
101 | input->inode_bitmap, start, metaend - 1); |
102 | else if (inside(input->inode_table, start, metaend) || | |
103 | inside(itend - 1, start, metaend)) | |
e05b6b52 | 104 | ext3_warning(sb, __func__, |
1c2bf374 MC |
105 | "Inode table (%u-"E3FSBLK") overlaps" |
106 | "GDT table ("E3FSBLK"-"E3FSBLK")", | |
1da177e4 LT |
107 | input->inode_table, itend - 1, start, metaend - 1); |
108 | else | |
109 | err = 0; | |
110 | brelse(bh); | |
111 | ||
112 | return err; | |
113 | } | |
114 | ||
115 | static struct buffer_head *bclean(handle_t *handle, struct super_block *sb, | |
43d23f90 | 116 | ext3_fsblk_t blk) |
1da177e4 LT |
117 | { |
118 | struct buffer_head *bh; | |
119 | int err; | |
120 | ||
121 | bh = sb_getblk(sb, blk); | |
2973dfdb GOC |
122 | if (!bh) |
123 | return ERR_PTR(-EIO); | |
1da177e4 LT |
124 | if ((err = ext3_journal_get_write_access(handle, bh))) { |
125 | brelse(bh); | |
126 | bh = ERR_PTR(err); | |
127 | } else { | |
128 | lock_buffer(bh); | |
129 | memset(bh->b_data, 0, sb->s_blocksize); | |
130 | set_buffer_uptodate(bh); | |
131 | unlock_buffer(bh); | |
132 | } | |
133 | ||
134 | return bh; | |
135 | } | |
136 | ||
137 | /* | |
138 | * To avoid calling the atomic setbit hundreds or thousands of times, we only | |
139 | * need to use it within a single byte (to ensure we get endianness right). | |
140 | * We can use memset for the rest of the bitmap as there are no other users. | |
141 | */ | |
142 | static void mark_bitmap_end(int start_bit, int end_bit, char *bitmap) | |
143 | { | |
144 | int i; | |
145 | ||
146 | if (start_bit >= end_bit) | |
147 | return; | |
148 | ||
149 | ext3_debug("mark end bits +%d through +%d used\n", start_bit, end_bit); | |
150 | for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++) | |
151 | ext3_set_bit(i, bitmap); | |
152 | if (i < end_bit) | |
153 | memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3); | |
154 | } | |
155 | ||
1ad6ecf9 ES |
156 | /* |
157 | * If we have fewer than thresh credits, extend by EXT3_MAX_TRANS_DATA. | |
158 | * If that fails, restart the transaction & regain write access for the | |
159 | * buffer head which is used for block_bitmap modifications. | |
160 | */ | |
161 | static int extend_or_restart_transaction(handle_t *handle, int thresh, | |
162 | struct buffer_head *bh) | |
163 | { | |
164 | int err; | |
165 | ||
166 | if (handle->h_buffer_credits >= thresh) | |
167 | return 0; | |
168 | ||
169 | err = ext3_journal_extend(handle, EXT3_MAX_TRANS_DATA); | |
170 | if (err < 0) | |
171 | return err; | |
172 | if (err) { | |
173 | err = ext3_journal_restart(handle, EXT3_MAX_TRANS_DATA); | |
174 | if (err) | |
175 | return err; | |
176 | err = ext3_journal_get_write_access(handle, bh); | |
177 | if (err) | |
178 | return err; | |
179 | } | |
180 | ||
181 | return 0; | |
182 | } | |
183 | ||
1da177e4 LT |
184 | /* |
185 | * Set up the block and inode bitmaps, and the inode table for the new group. | |
186 | * This doesn't need to be part of the main transaction, since we are only | |
187 | * changing blocks outside the actual filesystem. We still do journaling to | |
188 | * ensure the recovery is correct in case of a failure just after resize. | |
189 | * If any part of this fails, we simply abort the resize. | |
190 | */ | |
191 | static int setup_new_group_blocks(struct super_block *sb, | |
192 | struct ext3_new_group_data *input) | |
193 | { | |
194 | struct ext3_sb_info *sbi = EXT3_SB(sb); | |
43d23f90 | 195 | ext3_fsblk_t start = ext3_group_first_block_no(sb, input->group); |
1da177e4 LT |
196 | int reserved_gdb = ext3_bg_has_super(sb, input->group) ? |
197 | le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0; | |
198 | unsigned long gdblocks = ext3_bg_num_gdb(sb, input->group); | |
199 | struct buffer_head *bh; | |
200 | handle_t *handle; | |
43d23f90 | 201 | ext3_fsblk_t block; |
1c2bf374 | 202 | ext3_grpblk_t bit; |
1da177e4 LT |
203 | int i; |
204 | int err = 0, err2; | |
205 | ||
1ad6ecf9 ES |
206 | /* This transaction may be extended/restarted along the way */ |
207 | handle = ext3_journal_start_sb(sb, EXT3_MAX_TRANS_DATA); | |
208 | ||
1da177e4 LT |
209 | if (IS_ERR(handle)) |
210 | return PTR_ERR(handle); | |
211 | ||
96d2a495 | 212 | mutex_lock(&sbi->s_resize_lock); |
1da177e4 LT |
213 | if (input->group != sbi->s_groups_count) { |
214 | err = -EBUSY; | |
215 | goto exit_journal; | |
216 | } | |
217 | ||
218 | if (IS_ERR(bh = bclean(handle, sb, input->block_bitmap))) { | |
219 | err = PTR_ERR(bh); | |
220 | goto exit_journal; | |
221 | } | |
222 | ||
223 | if (ext3_bg_has_super(sb, input->group)) { | |
224 | ext3_debug("mark backup superblock %#04lx (+0)\n", start); | |
225 | ext3_set_bit(0, bh->b_data); | |
226 | } | |
227 | ||
228 | /* Copy all of the GDT blocks into the backup in this group */ | |
229 | for (i = 0, bit = 1, block = start + 1; | |
230 | i < gdblocks; i++, block++, bit++) { | |
231 | struct buffer_head *gdb; | |
232 | ||
233 | ext3_debug("update backup group %#04lx (+%d)\n", block, bit); | |
234 | ||
1ad6ecf9 ES |
235 | err = extend_or_restart_transaction(handle, 1, bh); |
236 | if (err) | |
237 | goto exit_bh; | |
238 | ||
1da177e4 | 239 | gdb = sb_getblk(sb, block); |
2973dfdb GOC |
240 | if (!gdb) { |
241 | err = -EIO; | |
242 | goto exit_bh; | |
243 | } | |
1da177e4 LT |
244 | if ((err = ext3_journal_get_write_access(handle, gdb))) { |
245 | brelse(gdb); | |
246 | goto exit_bh; | |
247 | } | |
42a2b6ad ES |
248 | lock_buffer(gdb); |
249 | memcpy(gdb->b_data, sbi->s_group_desc[i]->b_data, gdb->b_size); | |
1da177e4 | 250 | set_buffer_uptodate(gdb); |
42a2b6ad | 251 | unlock_buffer(gdb); |
1da177e4 LT |
252 | ext3_journal_dirty_metadata(handle, gdb); |
253 | ext3_set_bit(bit, bh->b_data); | |
254 | brelse(gdb); | |
255 | } | |
256 | ||
257 | /* Zero out all of the reserved backup group descriptor table blocks */ | |
258 | for (i = 0, bit = gdblocks + 1, block = start + bit; | |
259 | i < reserved_gdb; i++, block++, bit++) { | |
260 | struct buffer_head *gdb; | |
261 | ||
262 | ext3_debug("clear reserved block %#04lx (+%d)\n", block, bit); | |
263 | ||
1ad6ecf9 ES |
264 | err = extend_or_restart_transaction(handle, 1, bh); |
265 | if (err) | |
266 | goto exit_bh; | |
267 | ||
1da177e4 | 268 | if (IS_ERR(gdb = bclean(handle, sb, block))) { |
8e0eb401 | 269 | err = PTR_ERR(gdb); |
1da177e4 LT |
270 | goto exit_bh; |
271 | } | |
272 | ext3_journal_dirty_metadata(handle, gdb); | |
273 | ext3_set_bit(bit, bh->b_data); | |
274 | brelse(gdb); | |
275 | } | |
276 | ext3_debug("mark block bitmap %#04x (+%ld)\n", input->block_bitmap, | |
277 | input->block_bitmap - start); | |
278 | ext3_set_bit(input->block_bitmap - start, bh->b_data); | |
279 | ext3_debug("mark inode bitmap %#04x (+%ld)\n", input->inode_bitmap, | |
280 | input->inode_bitmap - start); | |
281 | ext3_set_bit(input->inode_bitmap - start, bh->b_data); | |
282 | ||
283 | /* Zero out all of the inode table blocks */ | |
284 | for (i = 0, block = input->inode_table, bit = block - start; | |
285 | i < sbi->s_itb_per_group; i++, bit++, block++) { | |
286 | struct buffer_head *it; | |
287 | ||
8bdac5d1 | 288 | ext3_debug("clear inode block %#04lx (+%d)\n", block, bit); |
1ad6ecf9 ES |
289 | |
290 | err = extend_or_restart_transaction(handle, 1, bh); | |
291 | if (err) | |
292 | goto exit_bh; | |
293 | ||
1da177e4 LT |
294 | if (IS_ERR(it = bclean(handle, sb, block))) { |
295 | err = PTR_ERR(it); | |
296 | goto exit_bh; | |
297 | } | |
298 | ext3_journal_dirty_metadata(handle, it); | |
299 | brelse(it); | |
300 | ext3_set_bit(bit, bh->b_data); | |
301 | } | |
1ad6ecf9 ES |
302 | |
303 | err = extend_or_restart_transaction(handle, 2, bh); | |
304 | if (err) | |
305 | goto exit_bh; | |
306 | ||
1da177e4 LT |
307 | mark_bitmap_end(input->blocks_count, EXT3_BLOCKS_PER_GROUP(sb), |
308 | bh->b_data); | |
309 | ext3_journal_dirty_metadata(handle, bh); | |
310 | brelse(bh); | |
311 | ||
312 | /* Mark unused entries in inode bitmap used */ | |
313 | ext3_debug("clear inode bitmap %#04x (+%ld)\n", | |
314 | input->inode_bitmap, input->inode_bitmap - start); | |
315 | if (IS_ERR(bh = bclean(handle, sb, input->inode_bitmap))) { | |
316 | err = PTR_ERR(bh); | |
317 | goto exit_journal; | |
318 | } | |
319 | ||
320 | mark_bitmap_end(EXT3_INODES_PER_GROUP(sb), EXT3_BLOCKS_PER_GROUP(sb), | |
321 | bh->b_data); | |
322 | ext3_journal_dirty_metadata(handle, bh); | |
323 | exit_bh: | |
324 | brelse(bh); | |
325 | ||
326 | exit_journal: | |
96d2a495 | 327 | mutex_unlock(&sbi->s_resize_lock); |
1da177e4 LT |
328 | if ((err2 = ext3_journal_stop(handle)) && !err) |
329 | err = err2; | |
330 | ||
331 | return err; | |
332 | } | |
333 | ||
334 | /* | |
335 | * Iterate through the groups which hold BACKUP superblock/GDT copies in an | |
336 | * ext3 filesystem. The counters should be initialized to 1, 5, and 7 before | |
337 | * calling this for the first time. In a sparse filesystem it will be the | |
338 | * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ... | |
339 | * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ... | |
340 | */ | |
341 | static unsigned ext3_list_backups(struct super_block *sb, unsigned *three, | |
342 | unsigned *five, unsigned *seven) | |
343 | { | |
344 | unsigned *min = three; | |
345 | int mult = 3; | |
346 | unsigned ret; | |
347 | ||
348 | if (!EXT3_HAS_RO_COMPAT_FEATURE(sb, | |
349 | EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)) { | |
350 | ret = *min; | |
351 | *min += 1; | |
352 | return ret; | |
353 | } | |
354 | ||
355 | if (*five < *min) { | |
356 | min = five; | |
357 | mult = 5; | |
358 | } | |
359 | if (*seven < *min) { | |
360 | min = seven; | |
361 | mult = 7; | |
362 | } | |
363 | ||
364 | ret = *min; | |
365 | *min *= mult; | |
366 | ||
367 | return ret; | |
368 | } | |
369 | ||
370 | /* | |
371 | * Check that all of the backup GDT blocks are held in the primary GDT block. | |
372 | * It is assumed that they are stored in group order. Returns the number of | |
373 | * groups in current filesystem that have BACKUPS, or -ve error code. | |
374 | */ | |
375 | static int verify_reserved_gdb(struct super_block *sb, | |
376 | struct buffer_head *primary) | |
377 | { | |
43d23f90 | 378 | const ext3_fsblk_t blk = primary->b_blocknr; |
1da177e4 LT |
379 | const unsigned long end = EXT3_SB(sb)->s_groups_count; |
380 | unsigned three = 1; | |
381 | unsigned five = 5; | |
382 | unsigned seven = 7; | |
383 | unsigned grp; | |
a4e4de36 | 384 | __le32 *p = (__le32 *)primary->b_data; |
1da177e4 LT |
385 | int gdbackups = 0; |
386 | ||
387 | while ((grp = ext3_list_backups(sb, &three, &five, &seven)) < end) { | |
388 | if (le32_to_cpu(*p++) != grp * EXT3_BLOCKS_PER_GROUP(sb) + blk){ | |
e05b6b52 | 389 | ext3_warning(sb, __func__, |
43d23f90 MC |
390 | "reserved GDT "E3FSBLK |
391 | " missing grp %d ("E3FSBLK")", | |
1da177e4 LT |
392 | blk, grp, |
393 | grp * EXT3_BLOCKS_PER_GROUP(sb) + blk); | |
394 | return -EINVAL; | |
395 | } | |
396 | if (++gdbackups > EXT3_ADDR_PER_BLOCK(sb)) | |
397 | return -EFBIG; | |
398 | } | |
399 | ||
400 | return gdbackups; | |
401 | } | |
402 | ||
403 | /* | |
404 | * Called when we need to bring a reserved group descriptor table block into | |
405 | * use from the resize inode. The primary copy of the new GDT block currently | |
406 | * is an indirect block (under the double indirect block in the resize inode). | |
407 | * The new backup GDT blocks will be stored as leaf blocks in this indirect | |
408 | * block, in group order. Even though we know all the block numbers we need, | |
409 | * we check to ensure that the resize inode has actually reserved these blocks. | |
410 | * | |
411 | * Don't need to update the block bitmaps because the blocks are still in use. | |
412 | * | |
413 | * We get all of the error cases out of the way, so that we are sure to not | |
414 | * fail once we start modifying the data on disk, because JBD has no rollback. | |
415 | */ | |
416 | static int add_new_gdb(handle_t *handle, struct inode *inode, | |
417 | struct ext3_new_group_data *input, | |
418 | struct buffer_head **primary) | |
419 | { | |
420 | struct super_block *sb = inode->i_sb; | |
421 | struct ext3_super_block *es = EXT3_SB(sb)->s_es; | |
422 | unsigned long gdb_num = input->group / EXT3_DESC_PER_BLOCK(sb); | |
43d23f90 | 423 | ext3_fsblk_t gdblock = EXT3_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num; |
1da177e4 LT |
424 | struct buffer_head **o_group_desc, **n_group_desc; |
425 | struct buffer_head *dind; | |
426 | int gdbackups; | |
427 | struct ext3_iloc iloc; | |
a4e4de36 | 428 | __le32 *data; |
1da177e4 LT |
429 | int err; |
430 | ||
431 | if (test_opt(sb, DEBUG)) | |
432 | printk(KERN_DEBUG | |
433 | "EXT3-fs: ext3_add_new_gdb: adding group block %lu\n", | |
434 | gdb_num); | |
435 | ||
436 | /* | |
437 | * If we are not using the primary superblock/GDT copy don't resize, | |
438 | * because the user tools have no way of handling this. Probably a | |
439 | * bad time to do it anyways. | |
440 | */ | |
441 | if (EXT3_SB(sb)->s_sbh->b_blocknr != | |
442 | le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block)) { | |
e05b6b52 | 443 | ext3_warning(sb, __func__, |
9f40668d | 444 | "won't resize using backup superblock at %llu", |
1da177e4 LT |
445 | (unsigned long long)EXT3_SB(sb)->s_sbh->b_blocknr); |
446 | return -EPERM; | |
447 | } | |
448 | ||
449 | *primary = sb_bread(sb, gdblock); | |
450 | if (!*primary) | |
451 | return -EIO; | |
452 | ||
453 | if ((gdbackups = verify_reserved_gdb(sb, *primary)) < 0) { | |
454 | err = gdbackups; | |
455 | goto exit_bh; | |
456 | } | |
457 | ||
458 | data = EXT3_I(inode)->i_data + EXT3_DIND_BLOCK; | |
459 | dind = sb_bread(sb, le32_to_cpu(*data)); | |
460 | if (!dind) { | |
461 | err = -EIO; | |
462 | goto exit_bh; | |
463 | } | |
464 | ||
a4e4de36 | 465 | data = (__le32 *)dind->b_data; |
1da177e4 | 466 | if (le32_to_cpu(data[gdb_num % EXT3_ADDR_PER_BLOCK(sb)]) != gdblock) { |
e05b6b52 | 467 | ext3_warning(sb, __func__, |
43d23f90 | 468 | "new group %u GDT block "E3FSBLK" not reserved", |
1da177e4 LT |
469 | input->group, gdblock); |
470 | err = -EINVAL; | |
471 | goto exit_dind; | |
472 | } | |
473 | ||
474 | if ((err = ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh))) | |
475 | goto exit_dind; | |
476 | ||
477 | if ((err = ext3_journal_get_write_access(handle, *primary))) | |
478 | goto exit_sbh; | |
479 | ||
480 | if ((err = ext3_journal_get_write_access(handle, dind))) | |
481 | goto exit_primary; | |
482 | ||
483 | /* ext3_reserve_inode_write() gets a reference on the iloc */ | |
484 | if ((err = ext3_reserve_inode_write(handle, inode, &iloc))) | |
485 | goto exit_dindj; | |
486 | ||
f52720ca | 487 | n_group_desc = kmalloc((gdb_num + 1) * sizeof(struct buffer_head *), |
c587f0c0 | 488 | GFP_NOFS); |
1da177e4 LT |
489 | if (!n_group_desc) { |
490 | err = -ENOMEM; | |
e05b6b52 | 491 | ext3_warning (sb, __func__, |
1da177e4 LT |
492 | "not enough memory for %lu groups", gdb_num + 1); |
493 | goto exit_inode; | |
494 | } | |
495 | ||
496 | /* | |
497 | * Finally, we have all of the possible failures behind us... | |
498 | * | |
499 | * Remove new GDT block from inode double-indirect block and clear out | |
500 | * the new GDT block for use (which also "frees" the backup GDT blocks | |
501 | * from the reserved inode). We don't need to change the bitmaps for | |
502 | * these blocks, because they are marked as in-use from being in the | |
503 | * reserved inode, and will become GDT blocks (primary and backup). | |
504 | */ | |
505 | data[gdb_num % EXT3_ADDR_PER_BLOCK(sb)] = 0; | |
506 | ext3_journal_dirty_metadata(handle, dind); | |
507 | brelse(dind); | |
508 | inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9; | |
509 | ext3_mark_iloc_dirty(handle, inode, &iloc); | |
510 | memset((*primary)->b_data, 0, sb->s_blocksize); | |
511 | ext3_journal_dirty_metadata(handle, *primary); | |
512 | ||
513 | o_group_desc = EXT3_SB(sb)->s_group_desc; | |
514 | memcpy(n_group_desc, o_group_desc, | |
515 | EXT3_SB(sb)->s_gdb_count * sizeof(struct buffer_head *)); | |
516 | n_group_desc[gdb_num] = *primary; | |
517 | EXT3_SB(sb)->s_group_desc = n_group_desc; | |
518 | EXT3_SB(sb)->s_gdb_count++; | |
519 | kfree(o_group_desc); | |
520 | ||
50e8a289 | 521 | le16_add_cpu(&es->s_reserved_gdt_blocks, -1); |
1da177e4 LT |
522 | ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh); |
523 | ||
524 | return 0; | |
525 | ||
526 | exit_inode: | |
527 | //ext3_journal_release_buffer(handle, iloc.bh); | |
528 | brelse(iloc.bh); | |
529 | exit_dindj: | |
530 | //ext3_journal_release_buffer(handle, dind); | |
531 | exit_primary: | |
532 | //ext3_journal_release_buffer(handle, *primary); | |
533 | exit_sbh: | |
534 | //ext3_journal_release_buffer(handle, *primary); | |
535 | exit_dind: | |
536 | brelse(dind); | |
537 | exit_bh: | |
538 | brelse(*primary); | |
539 | ||
540 | ext3_debug("leaving with error %d\n", err); | |
541 | return err; | |
542 | } | |
543 | ||
544 | /* | |
545 | * Called when we are adding a new group which has a backup copy of each of | |
546 | * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks. | |
547 | * We need to add these reserved backup GDT blocks to the resize inode, so | |
548 | * that they are kept for future resizing and not allocated to files. | |
549 | * | |
550 | * Each reserved backup GDT block will go into a different indirect block. | |
551 | * The indirect blocks are actually the primary reserved GDT blocks, | |
552 | * so we know in advance what their block numbers are. We only get the | |
553 | * double-indirect block to verify it is pointing to the primary reserved | |
554 | * GDT blocks so we don't overwrite a data block by accident. The reserved | |
555 | * backup GDT blocks are stored in their reserved primary GDT block. | |
556 | */ | |
557 | static int reserve_backup_gdb(handle_t *handle, struct inode *inode, | |
558 | struct ext3_new_group_data *input) | |
559 | { | |
560 | struct super_block *sb = inode->i_sb; | |
561 | int reserved_gdb =le16_to_cpu(EXT3_SB(sb)->s_es->s_reserved_gdt_blocks); | |
562 | struct buffer_head **primary; | |
563 | struct buffer_head *dind; | |
564 | struct ext3_iloc iloc; | |
43d23f90 | 565 | ext3_fsblk_t blk; |
a4e4de36 | 566 | __le32 *data, *end; |
1da177e4 LT |
567 | int gdbackups = 0; |
568 | int res, i; | |
569 | int err; | |
570 | ||
c587f0c0 | 571 | primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS); |
1da177e4 LT |
572 | if (!primary) |
573 | return -ENOMEM; | |
574 | ||
575 | data = EXT3_I(inode)->i_data + EXT3_DIND_BLOCK; | |
576 | dind = sb_bread(sb, le32_to_cpu(*data)); | |
577 | if (!dind) { | |
578 | err = -EIO; | |
579 | goto exit_free; | |
580 | } | |
581 | ||
582 | blk = EXT3_SB(sb)->s_sbh->b_blocknr + 1 + EXT3_SB(sb)->s_gdb_count; | |
9bb91784 JB |
583 | data = (__le32 *)dind->b_data + (EXT3_SB(sb)->s_gdb_count % |
584 | EXT3_ADDR_PER_BLOCK(sb)); | |
a4e4de36 | 585 | end = (__le32 *)dind->b_data + EXT3_ADDR_PER_BLOCK(sb); |
1da177e4 LT |
586 | |
587 | /* Get each reserved primary GDT block and verify it holds backups */ | |
588 | for (res = 0; res < reserved_gdb; res++, blk++) { | |
589 | if (le32_to_cpu(*data) != blk) { | |
e05b6b52 | 590 | ext3_warning(sb, __func__, |
43d23f90 MC |
591 | "reserved block "E3FSBLK |
592 | " not at offset %ld", | |
a4e4de36 DK |
593 | blk, |
594 | (long)(data - (__le32 *)dind->b_data)); | |
1da177e4 LT |
595 | err = -EINVAL; |
596 | goto exit_bh; | |
597 | } | |
598 | primary[res] = sb_bread(sb, blk); | |
599 | if (!primary[res]) { | |
600 | err = -EIO; | |
601 | goto exit_bh; | |
602 | } | |
603 | if ((gdbackups = verify_reserved_gdb(sb, primary[res])) < 0) { | |
604 | brelse(primary[res]); | |
605 | err = gdbackups; | |
606 | goto exit_bh; | |
607 | } | |
608 | if (++data >= end) | |
a4e4de36 | 609 | data = (__le32 *)dind->b_data; |
1da177e4 LT |
610 | } |
611 | ||
612 | for (i = 0; i < reserved_gdb; i++) { | |
613 | if ((err = ext3_journal_get_write_access(handle, primary[i]))) { | |
614 | /* | |
615 | int j; | |
616 | for (j = 0; j < i; j++) | |
617 | ext3_journal_release_buffer(handle, primary[j]); | |
618 | */ | |
619 | goto exit_bh; | |
620 | } | |
621 | } | |
622 | ||
623 | if ((err = ext3_reserve_inode_write(handle, inode, &iloc))) | |
624 | goto exit_bh; | |
625 | ||
626 | /* | |
627 | * Finally we can add each of the reserved backup GDT blocks from | |
628 | * the new group to its reserved primary GDT block. | |
629 | */ | |
630 | blk = input->group * EXT3_BLOCKS_PER_GROUP(sb); | |
631 | for (i = 0; i < reserved_gdb; i++) { | |
632 | int err2; | |
a4e4de36 | 633 | data = (__le32 *)primary[i]->b_data; |
1da177e4 LT |
634 | /* printk("reserving backup %lu[%u] = %lu\n", |
635 | primary[i]->b_blocknr, gdbackups, | |
636 | blk + primary[i]->b_blocknr); */ | |
637 | data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr); | |
638 | err2 = ext3_journal_dirty_metadata(handle, primary[i]); | |
639 | if (!err) | |
640 | err = err2; | |
641 | } | |
642 | inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9; | |
643 | ext3_mark_iloc_dirty(handle, inode, &iloc); | |
644 | ||
645 | exit_bh: | |
646 | while (--res >= 0) | |
647 | brelse(primary[res]); | |
648 | brelse(dind); | |
649 | ||
650 | exit_free: | |
651 | kfree(primary); | |
652 | ||
653 | return err; | |
654 | } | |
655 | ||
656 | /* | |
657 | * Update the backup copies of the ext3 metadata. These don't need to be part | |
658 | * of the main resize transaction, because e2fsck will re-write them if there | |
659 | * is a problem (basically only OOM will cause a problem). However, we | |
660 | * _should_ update the backups if possible, in case the primary gets trashed | |
661 | * for some reason and we need to run e2fsck from a backup superblock. The | |
662 | * important part is that the new block and inode counts are in the backup | |
663 | * superblocks, and the location of the new group metadata in the GDT backups. | |
664 | * | |
96d2a495 ES |
665 | * We do not need take the s_resize_lock for this, because these |
666 | * blocks are not otherwise touched by the filesystem code when it is | |
667 | * mounted. We don't need to worry about last changing from | |
668 | * sbi->s_groups_count, because the worst that can happen is that we | |
669 | * do not copy the full number of backups at this time. The resize | |
670 | * which changed s_groups_count will backup again. | |
1da177e4 LT |
671 | */ |
672 | static void update_backups(struct super_block *sb, | |
673 | int blk_off, char *data, int size) | |
674 | { | |
675 | struct ext3_sb_info *sbi = EXT3_SB(sb); | |
676 | const unsigned long last = sbi->s_groups_count; | |
677 | const int bpg = EXT3_BLOCKS_PER_GROUP(sb); | |
678 | unsigned three = 1; | |
679 | unsigned five = 5; | |
680 | unsigned seven = 7; | |
681 | unsigned group; | |
682 | int rest = sb->s_blocksize - size; | |
683 | handle_t *handle; | |
684 | int err = 0, err2; | |
685 | ||
686 | handle = ext3_journal_start_sb(sb, EXT3_MAX_TRANS_DATA); | |
687 | if (IS_ERR(handle)) { | |
688 | group = 1; | |
689 | err = PTR_ERR(handle); | |
690 | goto exit_err; | |
691 | } | |
692 | ||
693 | while ((group = ext3_list_backups(sb, &three, &five, &seven)) < last) { | |
694 | struct buffer_head *bh; | |
695 | ||
696 | /* Out of journal space, and can't get more - abort - so sad */ | |
697 | if (handle->h_buffer_credits == 0 && | |
698 | ext3_journal_extend(handle, EXT3_MAX_TRANS_DATA) && | |
699 | (err = ext3_journal_restart(handle, EXT3_MAX_TRANS_DATA))) | |
700 | break; | |
701 | ||
702 | bh = sb_getblk(sb, group * bpg + blk_off); | |
2973dfdb GOC |
703 | if (!bh) { |
704 | err = -EIO; | |
705 | break; | |
706 | } | |
8bdac5d1 GOC |
707 | ext3_debug("update metadata backup %#04lx\n", |
708 | (unsigned long)bh->b_blocknr); | |
1da177e4 LT |
709 | if ((err = ext3_journal_get_write_access(handle, bh))) |
710 | break; | |
711 | lock_buffer(bh); | |
712 | memcpy(bh->b_data, data, size); | |
713 | if (rest) | |
714 | memset(bh->b_data + size, 0, rest); | |
715 | set_buffer_uptodate(bh); | |
716 | unlock_buffer(bh); | |
717 | ext3_journal_dirty_metadata(handle, bh); | |
718 | brelse(bh); | |
719 | } | |
720 | if ((err2 = ext3_journal_stop(handle)) && !err) | |
721 | err = err2; | |
722 | ||
723 | /* | |
724 | * Ugh! Need to have e2fsck write the backup copies. It is too | |
725 | * late to revert the resize, we shouldn't fail just because of | |
726 | * the backup copies (they are only needed in case of corruption). | |
727 | * | |
728 | * However, if we got here we have a journal problem too, so we | |
729 | * can't really start a transaction to mark the superblock. | |
730 | * Chicken out and just set the flag on the hope it will be written | |
731 | * to disk, and if not - we will simply wait until next fsck. | |
732 | */ | |
733 | exit_err: | |
734 | if (err) { | |
e05b6b52 | 735 | ext3_warning(sb, __func__, |
1da177e4 | 736 | "can't update backup for group %d (err %d), " |
9f40668d | 737 | "forcing fsck on next reboot", group, err); |
1da177e4 | 738 | sbi->s_mount_state &= ~EXT3_VALID_FS; |
a4e4de36 | 739 | sbi->s_es->s_state &= cpu_to_le16(~EXT3_VALID_FS); |
1da177e4 LT |
740 | mark_buffer_dirty(sbi->s_sbh); |
741 | } | |
742 | } | |
743 | ||
744 | /* Add group descriptor data to an existing or new group descriptor block. | |
745 | * Ensure we handle all possible error conditions _before_ we start modifying | |
746 | * the filesystem, because we cannot abort the transaction and not have it | |
747 | * write the data to disk. | |
748 | * | |
749 | * If we are on a GDT block boundary, we need to get the reserved GDT block. | |
750 | * Otherwise, we may need to add backup GDT blocks for a sparse group. | |
751 | * | |
752 | * We only need to hold the superblock lock while we are actually adding | |
753 | * in the new group's counts to the superblock. Prior to that we have | |
754 | * not really "added" the group at all. We re-check that we are still | |
755 | * adding in the last group in case things have changed since verifying. | |
756 | */ | |
757 | int ext3_group_add(struct super_block *sb, struct ext3_new_group_data *input) | |
758 | { | |
759 | struct ext3_sb_info *sbi = EXT3_SB(sb); | |
760 | struct ext3_super_block *es = sbi->s_es; | |
761 | int reserved_gdb = ext3_bg_has_super(sb, input->group) ? | |
762 | le16_to_cpu(es->s_reserved_gdt_blocks) : 0; | |
763 | struct buffer_head *primary = NULL; | |
764 | struct ext3_group_desc *gdp; | |
765 | struct inode *inode = NULL; | |
766 | handle_t *handle; | |
767 | int gdb_off, gdb_num; | |
768 | int err, err2; | |
769 | ||
770 | gdb_num = input->group / EXT3_DESC_PER_BLOCK(sb); | |
771 | gdb_off = input->group % EXT3_DESC_PER_BLOCK(sb); | |
772 | ||
773 | if (gdb_off == 0 && !EXT3_HAS_RO_COMPAT_FEATURE(sb, | |
774 | EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)) { | |
e05b6b52 | 775 | ext3_warning(sb, __func__, |
9f40668d | 776 | "Can't resize non-sparse filesystem further"); |
1da177e4 LT |
777 | return -EPERM; |
778 | } | |
779 | ||
32c2d2bc ES |
780 | if (le32_to_cpu(es->s_blocks_count) + input->blocks_count < |
781 | le32_to_cpu(es->s_blocks_count)) { | |
e05b6b52 | 782 | ext3_warning(sb, __func__, "blocks_count overflow\n"); |
32c2d2bc ES |
783 | return -EINVAL; |
784 | } | |
785 | ||
786 | if (le32_to_cpu(es->s_inodes_count) + EXT3_INODES_PER_GROUP(sb) < | |
787 | le32_to_cpu(es->s_inodes_count)) { | |
e05b6b52 | 788 | ext3_warning(sb, __func__, "inodes_count overflow\n"); |
32c2d2bc ES |
789 | return -EINVAL; |
790 | } | |
791 | ||
1da177e4 LT |
792 | if (reserved_gdb || gdb_off == 0) { |
793 | if (!EXT3_HAS_COMPAT_FEATURE(sb, | |
972fbf77 JB |
794 | EXT3_FEATURE_COMPAT_RESIZE_INODE) |
795 | || !le16_to_cpu(es->s_reserved_gdt_blocks)) { | |
e05b6b52 | 796 | ext3_warning(sb, __func__, |
9f40668d | 797 | "No reserved GDT blocks, can't resize"); |
1da177e4 LT |
798 | return -EPERM; |
799 | } | |
473043dc DH |
800 | inode = ext3_iget(sb, EXT3_RESIZE_INO); |
801 | if (IS_ERR(inode)) { | |
e05b6b52 | 802 | ext3_warning(sb, __func__, |
9f40668d | 803 | "Error opening resize inode"); |
473043dc | 804 | return PTR_ERR(inode); |
1da177e4 LT |
805 | } |
806 | } | |
807 | ||
808 | if ((err = verify_group_input(sb, input))) | |
809 | goto exit_put; | |
810 | ||
811 | if ((err = setup_new_group_blocks(sb, input))) | |
812 | goto exit_put; | |
813 | ||
814 | /* | |
815 | * We will always be modifying at least the superblock and a GDT | |
816 | * block. If we are adding a group past the last current GDT block, | |
817 | * we will also modify the inode and the dindirect block. If we | |
818 | * are adding a group with superblock/GDT backups we will also | |
819 | * modify each of the reserved GDT dindirect blocks. | |
820 | */ | |
821 | handle = ext3_journal_start_sb(sb, | |
822 | ext3_bg_has_super(sb, input->group) ? | |
823 | 3 + reserved_gdb : 4); | |
824 | if (IS_ERR(handle)) { | |
825 | err = PTR_ERR(handle); | |
826 | goto exit_put; | |
827 | } | |
828 | ||
96d2a495 | 829 | mutex_lock(&sbi->s_resize_lock); |
29ba1723 | 830 | if (input->group != sbi->s_groups_count) { |
e05b6b52 | 831 | ext3_warning(sb, __func__, |
9f40668d | 832 | "multiple resizers run on filesystem!"); |
aa877b3d | 833 | err = -EBUSY; |
1da177e4 LT |
834 | goto exit_journal; |
835 | } | |
836 | ||
837 | if ((err = ext3_journal_get_write_access(handle, sbi->s_sbh))) | |
838 | goto exit_journal; | |
839 | ||
840 | /* | |
841 | * We will only either add reserved group blocks to a backup group | |
842 | * or remove reserved blocks for the first group in a new group block. | |
843 | * Doing both would be mean more complex code, and sane people don't | |
844 | * use non-sparse filesystems anymore. This is already checked above. | |
845 | */ | |
846 | if (gdb_off) { | |
847 | primary = sbi->s_group_desc[gdb_num]; | |
848 | if ((err = ext3_journal_get_write_access(handle, primary))) | |
849 | goto exit_journal; | |
850 | ||
851 | if (reserved_gdb && ext3_bg_num_gdb(sb, input->group) && | |
852 | (err = reserve_backup_gdb(handle, inode, input))) | |
853 | goto exit_journal; | |
854 | } else if ((err = add_new_gdb(handle, inode, input, &primary))) | |
855 | goto exit_journal; | |
856 | ||
857 | /* | |
858 | * OK, now we've set up the new group. Time to make it active. | |
859 | * | |
96d2a495 | 860 | * We do not lock all allocations via s_resize_lock |
1da177e4 LT |
861 | * so we have to be safe wrt. concurrent accesses the group |
862 | * data. So we need to be careful to set all of the relevant | |
863 | * group descriptor data etc. *before* we enable the group. | |
864 | * | |
29ba1723 | 865 | * The key field here is sbi->s_groups_count: as long as |
1da177e4 LT |
866 | * that retains its old value, nobody is going to access the new |
867 | * group. | |
868 | * | |
869 | * So first we update all the descriptor metadata for the new | |
870 | * group; then we update the total disk blocks count; then we | |
871 | * update the groups count to enable the group; then finally we | |
872 | * update the free space counts so that the system can start | |
873 | * using the new disk blocks. | |
874 | */ | |
875 | ||
876 | /* Update group descriptor block for new group */ | |
877 | gdp = (struct ext3_group_desc *)primary->b_data + gdb_off; | |
878 | ||
879 | gdp->bg_block_bitmap = cpu_to_le32(input->block_bitmap); | |
880 | gdp->bg_inode_bitmap = cpu_to_le32(input->inode_bitmap); | |
881 | gdp->bg_inode_table = cpu_to_le32(input->inode_table); | |
882 | gdp->bg_free_blocks_count = cpu_to_le16(input->free_blocks_count); | |
883 | gdp->bg_free_inodes_count = cpu_to_le16(EXT3_INODES_PER_GROUP(sb)); | |
884 | ||
885 | /* | |
886 | * Make the new blocks and inodes valid next. We do this before | |
887 | * increasing the group count so that once the group is enabled, | |
888 | * all of its blocks and inodes are already valid. | |
889 | * | |
890 | * We always allocate group-by-group, then block-by-block or | |
891 | * inode-by-inode within a group, so enabling these | |
892 | * blocks/inodes before the group is live won't actually let us | |
893 | * allocate the new space yet. | |
894 | */ | |
50e8a289 MS |
895 | le32_add_cpu(&es->s_blocks_count, input->blocks_count); |
896 | le32_add_cpu(&es->s_inodes_count, EXT3_INODES_PER_GROUP(sb)); | |
1da177e4 LT |
897 | |
898 | /* | |
899 | * We need to protect s_groups_count against other CPUs seeing | |
900 | * inconsistent state in the superblock. | |
901 | * | |
902 | * The precise rules we use are: | |
903 | * | |
96d2a495 | 904 | * * Writers of s_groups_count *must* hold s_resize_lock |
1da177e4 LT |
905 | * AND |
906 | * * Writers must perform a smp_wmb() after updating all dependent | |
907 | * data and before modifying the groups count | |
908 | * | |
96d2a495 | 909 | * * Readers must hold s_resize_lock over the access |
1da177e4 LT |
910 | * OR |
911 | * * Readers must perform an smp_rmb() after reading the groups count | |
912 | * and before reading any dependent data. | |
913 | * | |
914 | * NB. These rules can be relaxed when checking the group count | |
915 | * while freeing data, as we can only allocate from a block | |
916 | * group after serialising against the group count, and we can | |
917 | * only then free after serialising in turn against that | |
918 | * allocation. | |
919 | */ | |
920 | smp_wmb(); | |
921 | ||
922 | /* Update the global fs size fields */ | |
29ba1723 | 923 | sbi->s_groups_count++; |
1da177e4 LT |
924 | |
925 | ext3_journal_dirty_metadata(handle, primary); | |
926 | ||
927 | /* Update the reserved block counts only once the new group is | |
928 | * active. */ | |
50e8a289 | 929 | le32_add_cpu(&es->s_r_blocks_count, input->reserved_blocks); |
1da177e4 LT |
930 | |
931 | /* Update the free space counts */ | |
aa0dff2d | 932 | percpu_counter_add(&sbi->s_freeblocks_counter, |
1da177e4 | 933 | input->free_blocks_count); |
aa0dff2d | 934 | percpu_counter_add(&sbi->s_freeinodes_counter, |
1da177e4 LT |
935 | EXT3_INODES_PER_GROUP(sb)); |
936 | ||
29ba1723 | 937 | ext3_journal_dirty_metadata(handle, sbi->s_sbh); |
1da177e4 LT |
938 | |
939 | exit_journal: | |
96d2a495 | 940 | mutex_unlock(&sbi->s_resize_lock); |
1da177e4 LT |
941 | if ((err2 = ext3_journal_stop(handle)) && !err) |
942 | err = err2; | |
943 | if (!err) { | |
944 | update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, | |
945 | sizeof(struct ext3_super_block)); | |
946 | update_backups(sb, primary->b_blocknr, primary->b_data, | |
947 | primary->b_size); | |
948 | } | |
949 | exit_put: | |
950 | iput(inode); | |
951 | return err; | |
952 | } /* ext3_group_add */ | |
953 | ||
954 | /* Extend the filesystem to the new number of blocks specified. This entry | |
955 | * point is only used to extend the current filesystem to the end of the last | |
956 | * existing group. It can be accessed via ioctl, or by "remount,resize=<size>" | |
957 | * for emergencies (because it has no dependencies on reserved blocks). | |
958 | * | |
959 | * If we _really_ wanted, we could use default values to call ext3_group_add() | |
960 | * allow the "remount" trick to work for arbitrary resizing, assuming enough | |
961 | * GDT blocks are reserved to grow to the desired size. | |
962 | */ | |
963 | int ext3_group_extend(struct super_block *sb, struct ext3_super_block *es, | |
43d23f90 | 964 | ext3_fsblk_t n_blocks_count) |
1da177e4 | 965 | { |
43d23f90 | 966 | ext3_fsblk_t o_blocks_count; |
1da177e4 | 967 | unsigned long o_groups_count; |
1c2bf374 MC |
968 | ext3_grpblk_t last; |
969 | ext3_grpblk_t add; | |
1da177e4 LT |
970 | struct buffer_head * bh; |
971 | handle_t *handle; | |
1c2bf374 MC |
972 | int err; |
973 | unsigned long freed_blocks; | |
1da177e4 LT |
974 | |
975 | /* We don't need to worry about locking wrt other resizers just | |
976 | * yet: we're going to revalidate es->s_blocks_count after | |
96d2a495 | 977 | * taking the s_resize_lock below. */ |
1da177e4 LT |
978 | o_blocks_count = le32_to_cpu(es->s_blocks_count); |
979 | o_groups_count = EXT3_SB(sb)->s_groups_count; | |
980 | ||
981 | if (test_opt(sb, DEBUG)) | |
43d23f90 | 982 | printk(KERN_DEBUG "EXT3-fs: extending last group from "E3FSBLK" uto "E3FSBLK" blocks\n", |
1da177e4 LT |
983 | o_blocks_count, n_blocks_count); |
984 | ||
985 | if (n_blocks_count == 0 || n_blocks_count == o_blocks_count) | |
986 | return 0; | |
987 | ||
fcd5df35 MC |
988 | if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) { |
989 | printk(KERN_ERR "EXT3-fs: filesystem on %s:" | |
990 | " too large to resize to %lu blocks safely\n", | |
991 | sb->s_id, n_blocks_count); | |
992 | if (sizeof(sector_t) < 8) | |
e05b6b52 | 993 | ext3_warning(sb, __func__, |
90c699a9 | 994 | "CONFIG_LBDAF not enabled\n"); |
fcd5df35 MC |
995 | return -EINVAL; |
996 | } | |
997 | ||
1da177e4 | 998 | if (n_blocks_count < o_blocks_count) { |
e05b6b52 | 999 | ext3_warning(sb, __func__, |
1da177e4 LT |
1000 | "can't shrink FS - resize aborted"); |
1001 | return -EBUSY; | |
1002 | } | |
1003 | ||
1004 | /* Handle the remaining blocks in the last group only. */ | |
1005 | last = (o_blocks_count - le32_to_cpu(es->s_first_data_block)) % | |
1006 | EXT3_BLOCKS_PER_GROUP(sb); | |
1007 | ||
1008 | if (last == 0) { | |
e05b6b52 | 1009 | ext3_warning(sb, __func__, |
9f40668d | 1010 | "need to use ext2online to resize further"); |
1da177e4 LT |
1011 | return -EPERM; |
1012 | } | |
1013 | ||
1014 | add = EXT3_BLOCKS_PER_GROUP(sb) - last; | |
1015 | ||
32c2d2bc | 1016 | if (o_blocks_count + add < o_blocks_count) { |
e05b6b52 | 1017 | ext3_warning(sb, __func__, "blocks_count overflow"); |
32c2d2bc ES |
1018 | return -EINVAL; |
1019 | } | |
1020 | ||
1da177e4 LT |
1021 | if (o_blocks_count + add > n_blocks_count) |
1022 | add = n_blocks_count - o_blocks_count; | |
1023 | ||
1024 | if (o_blocks_count + add < n_blocks_count) | |
e05b6b52 | 1025 | ext3_warning(sb, __func__, |
43d23f90 MC |
1026 | "will only finish group ("E3FSBLK |
1027 | " blocks, %u new)", | |
1da177e4 LT |
1028 | o_blocks_count + add, add); |
1029 | ||
1030 | /* See if the device is actually as big as what was requested */ | |
1031 | bh = sb_bread(sb, o_blocks_count + add -1); | |
1032 | if (!bh) { | |
e05b6b52 | 1033 | ext3_warning(sb, __func__, |
1da177e4 LT |
1034 | "can't read last block, resize aborted"); |
1035 | return -ENOSPC; | |
1036 | } | |
1037 | brelse(bh); | |
1038 | ||
1039 | /* We will update the superblock, one block bitmap, and | |
1040 | * one group descriptor via ext3_free_blocks(). | |
1041 | */ | |
1042 | handle = ext3_journal_start_sb(sb, 3); | |
1043 | if (IS_ERR(handle)) { | |
1044 | err = PTR_ERR(handle); | |
e05b6b52 | 1045 | ext3_warning(sb, __func__, "error %d on journal start",err); |
1da177e4 LT |
1046 | goto exit_put; |
1047 | } | |
1048 | ||
96d2a495 | 1049 | mutex_lock(&EXT3_SB(sb)->s_resize_lock); |
1da177e4 | 1050 | if (o_blocks_count != le32_to_cpu(es->s_blocks_count)) { |
e05b6b52 | 1051 | ext3_warning(sb, __func__, |
9f40668d | 1052 | "multiple resizers run on filesystem!"); |
96d2a495 | 1053 | mutex_unlock(&EXT3_SB(sb)->s_resize_lock); |
22a5daf5 | 1054 | ext3_journal_stop(handle); |
1da177e4 LT |
1055 | err = -EBUSY; |
1056 | goto exit_put; | |
1057 | } | |
1058 | ||
1059 | if ((err = ext3_journal_get_write_access(handle, | |
1060 | EXT3_SB(sb)->s_sbh))) { | |
e05b6b52 | 1061 | ext3_warning(sb, __func__, |
1da177e4 | 1062 | "error %d on journal write access", err); |
96d2a495 | 1063 | mutex_unlock(&EXT3_SB(sb)->s_resize_lock); |
1da177e4 LT |
1064 | ext3_journal_stop(handle); |
1065 | goto exit_put; | |
1066 | } | |
1067 | es->s_blocks_count = cpu_to_le32(o_blocks_count + add); | |
1068 | ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh); | |
96d2a495 | 1069 | mutex_unlock(&EXT3_SB(sb)->s_resize_lock); |
43d23f90 | 1070 | ext3_debug("freeing blocks %lu through "E3FSBLK"\n", o_blocks_count, |
1da177e4 LT |
1071 | o_blocks_count + add); |
1072 | ext3_free_blocks_sb(handle, sb, o_blocks_count, add, &freed_blocks); | |
43d23f90 | 1073 | ext3_debug("freed blocks "E3FSBLK" through "E3FSBLK"\n", o_blocks_count, |
1da177e4 LT |
1074 | o_blocks_count + add); |
1075 | if ((err = ext3_journal_stop(handle))) | |
1076 | goto exit_put; | |
1077 | if (test_opt(sb, DEBUG)) | |
1078 | printk(KERN_DEBUG "EXT3-fs: extended group to %u blocks\n", | |
1079 | le32_to_cpu(es->s_blocks_count)); | |
1080 | update_backups(sb, EXT3_SB(sb)->s_sbh->b_blocknr, (char *)es, | |
1081 | sizeof(struct ext3_super_block)); | |
1082 | exit_put: | |
1083 | return err; | |
1084 | } /* ext3_group_extend */ |