Branch data Line data Source code
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 : :
11 : :
12 : : #define EXT3FS_DEBUG
13 : :
14 : : #include "ext3.h"
15 : :
16 : :
17 : : #define outside(b, first, last) ((b) < (first) || (b) >= (last))
18 : : #define inside(b, first, last) ((b) >= (first) && (b) < (last))
19 : :
20 : 0 : static int verify_group_input(struct super_block *sb,
21 : : struct ext3_new_group_data *input)
22 : : {
23 : : struct ext3_sb_info *sbi = EXT3_SB(sb);
24 : 0 : struct ext3_super_block *es = sbi->s_es;
25 : 0 : ext3_fsblk_t start = le32_to_cpu(es->s_blocks_count);
26 : 0 : ext3_fsblk_t end = start + input->blocks_count;
27 : 0 : unsigned group = input->group;
28 : 0 : ext3_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
29 [ # # ]: 0 : unsigned overhead = ext3_bg_has_super(sb, group) ?
30 : 0 : (1 + ext3_bg_num_gdb(sb, group) +
31 : 0 : le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
32 : 0 : ext3_fsblk_t metaend = start + overhead;
33 : : struct buffer_head *bh = NULL;
34 : : ext3_grpblk_t free_blocks_count;
35 : : int err = -EINVAL;
36 : :
37 : 0 : input->free_blocks_count = free_blocks_count =
38 : 0 : input->blocks_count - 2 - overhead - sbi->s_itb_per_group;
39 : :
40 [ # # ]: 0 : if (test_opt(sb, DEBUG))
41 [ # # ]: 0 : printk(KERN_DEBUG "EXT3-fs: adding %s group %u: %u blocks "
42 : : "(%d free, %u reserved)\n",
43 : 0 : ext3_bg_has_super(sb, input->group) ? "normal" :
44 : : "no-super", input->group, input->blocks_count,
45 : 0 : free_blocks_count, input->reserved_blocks);
46 : :
47 [ # # ]: 0 : if (group != sbi->s_groups_count)
48 : 0 : ext3_warning(sb, __func__,
49 : : "Cannot add at group %u (only %lu groups)",
50 : : input->group, sbi->s_groups_count);
51 [ # # ]: 0 : else if ((start - le32_to_cpu(es->s_first_data_block)) %
52 : 0 : EXT3_BLOCKS_PER_GROUP(sb))
53 : 0 : ext3_warning(sb, __func__, "Last group not full");
54 [ # # ]: 0 : else if (input->reserved_blocks > input->blocks_count / 5)
55 : 0 : ext3_warning(sb, __func__, "Reserved blocks too high (%u)",
56 : : input->reserved_blocks);
57 [ # # ]: 0 : else if (free_blocks_count < 0)
58 : 0 : ext3_warning(sb, __func__, "Bad blocks count %u",
59 : : input->blocks_count);
60 [ # # ]: 0 : else if (!(bh = sb_bread(sb, end - 1)))
61 : 0 : ext3_warning(sb, __func__,
62 : : "Cannot read last block ("E3FSBLK")",
63 : : end - 1);
64 [ # # ][ # # ]: 0 : else if (outside(input->block_bitmap, start, end))
65 : 0 : ext3_warning(sb, __func__,
66 : : "Block bitmap not in group (block %u)",
67 : : input->block_bitmap);
68 [ # # ][ # # ]: 0 : else if (outside(input->inode_bitmap, start, end))
69 : 0 : ext3_warning(sb, __func__,
70 : : "Inode bitmap not in group (block %u)",
71 : : input->inode_bitmap);
72 [ # # ][ # # ]: 0 : else if (outside(input->inode_table, start, end) ||
[ # # ]
73 [ # # ]: 0 : outside(itend - 1, start, end))
74 : 0 : ext3_warning(sb, __func__,
75 : : "Inode table not in group (blocks %u-"E3FSBLK")",
76 : : input->inode_table, itend - 1);
77 [ # # ]: 0 : else if (input->inode_bitmap == input->block_bitmap)
78 : 0 : ext3_warning(sb, __func__,
79 : : "Block bitmap same as inode bitmap (%u)",
80 : : input->block_bitmap);
81 [ # # ][ # # ]: 0 : else if (inside(input->block_bitmap, input->inode_table, itend))
82 : 0 : ext3_warning(sb, __func__,
83 : : "Block bitmap (%u) in inode table (%u-"E3FSBLK")",
84 : : input->block_bitmap, input->inode_table, itend-1);
85 [ # # ][ # # ]: 0 : else if (inside(input->inode_bitmap, input->inode_table, itend))
86 : 0 : ext3_warning(sb, __func__,
87 : : "Inode bitmap (%u) in inode table (%u-"E3FSBLK")",
88 : : input->inode_bitmap, input->inode_table, itend-1);
89 [ # # ][ # # ]: 0 : else if (inside(input->block_bitmap, start, metaend))
90 : 0 : ext3_warning(sb, __func__,
91 : : "Block bitmap (%u) in GDT table"
92 : : " ("E3FSBLK"-"E3FSBLK")",
93 : : input->block_bitmap, start, metaend - 1);
94 [ # # ][ # # ]: 0 : else if (inside(input->inode_bitmap, start, metaend))
95 : 0 : ext3_warning(sb, __func__,
96 : : "Inode bitmap (%u) in GDT table"
97 : : " ("E3FSBLK"-"E3FSBLK")",
98 : : input->inode_bitmap, start, metaend - 1);
99 [ # # ][ # # ]: 0 : else if (inside(input->inode_table, start, metaend) ||
[ # # ]
100 [ # # ]: 0 : inside(itend - 1, start, metaend))
101 : 0 : ext3_warning(sb, __func__,
102 : : "Inode table (%u-"E3FSBLK") overlaps"
103 : : "GDT table ("E3FSBLK"-"E3FSBLK")",
104 : : input->inode_table, itend - 1, start, metaend - 1);
105 : : else
106 : : err = 0;
107 : : brelse(bh);
108 : :
109 : 0 : return err;
110 : : }
111 : :
112 : 0 : static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
113 : : ext3_fsblk_t blk)
114 : : {
115 : : struct buffer_head *bh;
116 : : int err;
117 : :
118 : 0 : bh = sb_getblk(sb, blk);
119 [ # # ]: 0 : if (unlikely(!bh))
120 : : return ERR_PTR(-ENOMEM);
121 [ # # ]: 0 : if ((err = ext3_journal_get_write_access(handle, bh))) {
122 : : brelse(bh);
123 : : bh = ERR_PTR(err);
124 : : } else {
125 : : lock_buffer(bh);
126 [ # # ]: 0 : memset(bh->b_data, 0, sb->s_blocksize);
127 : : set_buffer_uptodate(bh);
128 : 0 : unlock_buffer(bh);
129 : : }
130 : :
131 : 0 : return bh;
132 : : }
133 : :
134 : : /*
135 : : * To avoid calling the atomic setbit hundreds or thousands of times, we only
136 : : * need to use it within a single byte (to ensure we get endianness right).
137 : : * We can use memset for the rest of the bitmap as there are no other users.
138 : : */
139 : 0 : static void mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
140 : : {
141 : : int i;
142 : :
143 [ # # ]: 0 : if (start_bit >= end_bit)
144 : 0 : return;
145 : :
146 : : ext3_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
147 [ # # ]: 0 : for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
148 : : ext3_set_bit(i, bitmap);
149 [ # # ]: 0 : if (i < end_bit)
150 [ # # ]: 0 : memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
151 : : }
152 : :
153 : : /*
154 : : * If we have fewer than thresh credits, extend by EXT3_MAX_TRANS_DATA.
155 : : * If that fails, restart the transaction & regain write access for the
156 : : * buffer head which is used for block_bitmap modifications.
157 : : */
158 : 0 : static int extend_or_restart_transaction(handle_t *handle, int thresh,
159 : : struct buffer_head *bh)
160 : : {
161 : : int err;
162 : :
163 [ # # ]: 0 : if (handle->h_buffer_credits >= thresh)
164 : : return 0;
165 : :
166 : : err = ext3_journal_extend(handle, EXT3_MAX_TRANS_DATA);
167 [ # # ]: 0 : if (err < 0)
168 : : return err;
169 [ # # ]: 0 : if (err) {
170 : : err = ext3_journal_restart(handle, EXT3_MAX_TRANS_DATA);
171 [ # # ]: 0 : if (err)
172 : : return err;
173 : 0 : err = ext3_journal_get_write_access(handle, bh);
174 [ # # ]: 0 : if (err)
175 : 0 : return err;
176 : : }
177 : :
178 : : return 0;
179 : : }
180 : :
181 : : /*
182 : : * Set up the block and inode bitmaps, and the inode table for the new group.
183 : : * This doesn't need to be part of the main transaction, since we are only
184 : : * changing blocks outside the actual filesystem. We still do journaling to
185 : : * ensure the recovery is correct in case of a failure just after resize.
186 : : * If any part of this fails, we simply abort the resize.
187 : : */
188 : 0 : static int setup_new_group_blocks(struct super_block *sb,
189 : : struct ext3_new_group_data *input)
190 : : {
191 : : struct ext3_sb_info *sbi = EXT3_SB(sb);
192 : 0 : ext3_fsblk_t start = ext3_group_first_block_no(sb, input->group);
193 : 0 : int reserved_gdb = ext3_bg_has_super(sb, input->group) ?
194 [ # # ]: 0 : le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0;
195 : 0 : unsigned long gdblocks = ext3_bg_num_gdb(sb, input->group);
196 : : struct buffer_head *bh;
197 : : handle_t *handle;
198 : : ext3_fsblk_t block;
199 : : ext3_grpblk_t bit;
200 : : int i;
201 : : int err = 0, err2;
202 : :
203 : : /* This transaction may be extended/restarted along the way */
204 : 0 : handle = ext3_journal_start_sb(sb, EXT3_MAX_TRANS_DATA);
205 : :
206 [ # # ]: 0 : if (IS_ERR(handle))
207 : 0 : return PTR_ERR(handle);
208 : :
209 : 0 : mutex_lock(&sbi->s_resize_lock);
210 [ # # ]: 0 : if (input->group != sbi->s_groups_count) {
211 : : err = -EBUSY;
212 : : goto exit_journal;
213 : : }
214 : :
215 [ # # ]: 0 : if (IS_ERR(bh = bclean(handle, sb, input->block_bitmap))) {
216 : : err = PTR_ERR(bh);
217 : 0 : goto exit_journal;
218 : : }
219 : :
220 [ # # ]: 0 : if (ext3_bg_has_super(sb, input->group)) {
221 : : ext3_debug("mark backup superblock %#04lx (+0)\n", start);
222 : 0 : ext3_set_bit(0, bh->b_data);
223 : : }
224 : :
225 : : /* Copy all of the GDT blocks into the backup in this group */
226 [ # # ]: 0 : for (i = 0, bit = 1, block = start + 1;
227 : 0 : i < gdblocks; i++, block++, bit++) {
228 : : struct buffer_head *gdb;
229 : :
230 : : ext3_debug("update backup group %#04lx (+%d)\n", block, bit);
231 : :
232 : 0 : err = extend_or_restart_transaction(handle, 1, bh);
233 [ # # ]: 0 : if (err)
234 : : goto exit_bh;
235 : :
236 : 0 : gdb = sb_getblk(sb, block);
237 [ # # ]: 0 : if (unlikely(!gdb)) {
238 : : err = -ENOMEM;
239 : : goto exit_bh;
240 : : }
241 [ # # ]: 0 : if ((err = ext3_journal_get_write_access(handle, gdb))) {
242 : : brelse(gdb);
243 : : goto exit_bh;
244 : : }
245 : : lock_buffer(gdb);
246 : 0 : memcpy(gdb->b_data, sbi->s_group_desc[i]->b_data, gdb->b_size);
247 : : set_buffer_uptodate(gdb);
248 : 0 : unlock_buffer(gdb);
249 : 0 : err = ext3_journal_dirty_metadata(handle, gdb);
250 [ # # ]: 0 : if (err) {
251 : : brelse(gdb);
252 : : goto exit_bh;
253 : : }
254 : 0 : ext3_set_bit(bit, bh->b_data);
255 : : brelse(gdb);
256 : : }
257 : :
258 : : /* Zero out all of the reserved backup group descriptor table blocks */
259 [ # # ]: 0 : for (i = 0, bit = gdblocks + 1, block = start + bit;
260 : 0 : i < reserved_gdb; i++, block++, bit++) {
261 : : struct buffer_head *gdb;
262 : :
263 : : ext3_debug("clear reserved block %#04lx (+%d)\n", block, bit);
264 : :
265 : 0 : err = extend_or_restart_transaction(handle, 1, bh);
266 [ # # ]: 0 : if (err)
267 : : goto exit_bh;
268 : :
269 [ # # ]: 0 : if (IS_ERR(gdb = bclean(handle, sb, block))) {
270 : : err = PTR_ERR(gdb);
271 : 0 : goto exit_bh;
272 : : }
273 : 0 : err = ext3_journal_dirty_metadata(handle, gdb);
274 [ # # ]: 0 : if (err) {
275 : : brelse(gdb);
276 : : goto exit_bh;
277 : : }
278 : 0 : ext3_set_bit(bit, bh->b_data);
279 : : brelse(gdb);
280 : : }
281 : : ext3_debug("mark block bitmap %#04x (+%ld)\n", input->block_bitmap,
282 : : input->block_bitmap - start);
283 : 0 : ext3_set_bit(input->block_bitmap - start, bh->b_data);
284 : : ext3_debug("mark inode bitmap %#04x (+%ld)\n", input->inode_bitmap,
285 : : input->inode_bitmap - start);
286 : 0 : ext3_set_bit(input->inode_bitmap - start, bh->b_data);
287 : :
288 : : /* Zero out all of the inode table blocks */
289 [ # # ]: 0 : for (i = 0, block = input->inode_table, bit = block - start;
290 : 0 : i < sbi->s_itb_per_group; i++, bit++, block++) {
291 : : struct buffer_head *it;
292 : :
293 : : ext3_debug("clear inode block %#04lx (+%d)\n", block, bit);
294 : :
295 : 0 : err = extend_or_restart_transaction(handle, 1, bh);
296 [ # # ]: 0 : if (err)
297 : : goto exit_bh;
298 : :
299 [ # # ]: 0 : if (IS_ERR(it = bclean(handle, sb, block))) {
300 : : err = PTR_ERR(it);
301 : 0 : goto exit_bh;
302 : : }
303 : 0 : err = ext3_journal_dirty_metadata(handle, it);
304 [ # # ]: 0 : if (err) {
305 : : brelse(it);
306 : : goto exit_bh;
307 : : }
308 : : brelse(it);
309 : 0 : ext3_set_bit(bit, bh->b_data);
310 : : }
311 : :
312 : 0 : err = extend_or_restart_transaction(handle, 2, bh);
313 [ # # ]: 0 : if (err)
314 : : goto exit_bh;
315 : :
316 : 0 : mark_bitmap_end(input->blocks_count, EXT3_BLOCKS_PER_GROUP(sb),
317 : : bh->b_data);
318 : 0 : err = ext3_journal_dirty_metadata(handle, bh);
319 [ # # ]: 0 : if (err)
320 : : goto exit_bh;
321 : : brelse(bh);
322 : :
323 : : /* Mark unused entries in inode bitmap used */
324 : : ext3_debug("clear inode bitmap %#04x (+%ld)\n",
325 : : input->inode_bitmap, input->inode_bitmap - start);
326 [ # # ]: 0 : if (IS_ERR(bh = bclean(handle, sb, input->inode_bitmap))) {
327 : : err = PTR_ERR(bh);
328 : 0 : goto exit_journal;
329 : : }
330 : :
331 : 0 : mark_bitmap_end(EXT3_INODES_PER_GROUP(sb), EXT3_BLOCKS_PER_GROUP(sb),
332 : : bh->b_data);
333 : 0 : err = ext3_journal_dirty_metadata(handle, bh);
334 : : exit_bh:
335 : : brelse(bh);
336 : :
337 : : exit_journal:
338 : 0 : mutex_unlock(&sbi->s_resize_lock);
339 [ # # ][ # # ]: 0 : if ((err2 = ext3_journal_stop(handle)) && !err)
340 : : err = err2;
341 : :
342 : 0 : return err;
343 : : }
344 : :
345 : : /*
346 : : * Iterate through the groups which hold BACKUP superblock/GDT copies in an
347 : : * ext3 filesystem. The counters should be initialized to 1, 5, and 7 before
348 : : * calling this for the first time. In a sparse filesystem it will be the
349 : : * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
350 : : * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
351 : : */
352 : 0 : static unsigned ext3_list_backups(struct super_block *sb, unsigned *three,
353 : : unsigned *five, unsigned *seven)
354 : : {
355 : : unsigned *min = three;
356 : : int mult = 3;
357 : : unsigned ret;
358 : :
359 [ # # ][ # # ]: 0 : if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
360 : : EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
361 : 0 : ret = *min;
362 : 0 : *min += 1;
363 : : return ret;
364 : : }
365 : :
366 [ # # ][ # # ]: 0 : if (*five < *min) {
367 : : min = five;
368 : : mult = 5;
369 : : }
370 [ # # ][ # # ]: 0 : if (*seven < *min) {
371 : : min = seven;
372 : : mult = 7;
373 : : }
374 : :
375 : 0 : ret = *min;
376 : 0 : *min *= mult;
377 : :
378 : : return ret;
379 : : }
380 : :
381 : : /*
382 : : * Check that all of the backup GDT blocks are held in the primary GDT block.
383 : : * It is assumed that they are stored in group order. Returns the number of
384 : : * groups in current filesystem that have BACKUPS, or -ve error code.
385 : : */
386 : 0 : static int verify_reserved_gdb(struct super_block *sb,
387 : : struct buffer_head *primary)
388 : : {
389 : 0 : const ext3_fsblk_t blk = primary->b_blocknr;
390 : 0 : const unsigned long end = EXT3_SB(sb)->s_groups_count;
391 : 0 : unsigned three = 1;
392 : 0 : unsigned five = 5;
393 : 0 : unsigned seven = 7;
394 : : unsigned grp;
395 : 0 : __le32 *p = (__le32 *)primary->b_data;
396 : : int gdbackups = 0;
397 : :
398 [ # # ]: 0 : while ((grp = ext3_list_backups(sb, &three, &five, &seven)) < end) {
399 [ # # ]: 0 : if (le32_to_cpu(*p++) != grp * EXT3_BLOCKS_PER_GROUP(sb) + blk){
400 : 0 : ext3_warning(sb, __func__,
401 : : "reserved GDT "E3FSBLK
402 : : " missing grp %d ("E3FSBLK")",
403 : : blk, grp,
404 : : grp * EXT3_BLOCKS_PER_GROUP(sb) + blk);
405 : 0 : return -EINVAL;
406 : : }
407 [ # # ]: 0 : if (++gdbackups > EXT3_ADDR_PER_BLOCK(sb))
408 : : return -EFBIG;
409 : : }
410 : :
411 : : return gdbackups;
412 : : }
413 : :
414 : : /*
415 : : * Called when we need to bring a reserved group descriptor table block into
416 : : * use from the resize inode. The primary copy of the new GDT block currently
417 : : * is an indirect block (under the double indirect block in the resize inode).
418 : : * The new backup GDT blocks will be stored as leaf blocks in this indirect
419 : : * block, in group order. Even though we know all the block numbers we need,
420 : : * we check to ensure that the resize inode has actually reserved these blocks.
421 : : *
422 : : * Don't need to update the block bitmaps because the blocks are still in use.
423 : : *
424 : : * We get all of the error cases out of the way, so that we are sure to not
425 : : * fail once we start modifying the data on disk, because JBD has no rollback.
426 : : */
427 : 0 : static int add_new_gdb(handle_t *handle, struct inode *inode,
428 : : struct ext3_new_group_data *input,
429 : : struct buffer_head **primary)
430 : : {
431 : 0 : struct super_block *sb = inode->i_sb;
432 : 0 : struct ext3_super_block *es = EXT3_SB(sb)->s_es;
433 : 0 : unsigned long gdb_num = input->group / EXT3_DESC_PER_BLOCK(sb);
434 : 0 : ext3_fsblk_t gdblock = EXT3_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
435 : : struct buffer_head **o_group_desc, **n_group_desc;
436 : : struct buffer_head *dind;
437 : : int gdbackups;
438 : : struct ext3_iloc iloc;
439 : : __le32 *data;
440 : : int err;
441 : :
442 [ # # ]: 0 : if (test_opt(sb, DEBUG))
443 : 0 : printk(KERN_DEBUG
444 : : "EXT3-fs: ext3_add_new_gdb: adding group block %lu\n",
445 : : gdb_num);
446 : :
447 : : /*
448 : : * If we are not using the primary superblock/GDT copy don't resize,
449 : : * because the user tools have no way of handling this. Probably a
450 : : * bad time to do it anyways.
451 : : */
452 [ # # ]: 0 : if (EXT3_SB(sb)->s_sbh->b_blocknr !=
453 : 0 : le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block)) {
454 : 0 : ext3_warning(sb, __func__,
455 : : "won't resize using backup superblock at %llu",
456 : : (unsigned long long)EXT3_SB(sb)->s_sbh->b_blocknr);
457 : : return -EPERM;
458 : : }
459 : :
460 : 0 : *primary = sb_bread(sb, gdblock);
461 [ # # ]: 0 : if (!*primary)
462 : : return -EIO;
463 : :
464 [ # # ]: 0 : if ((gdbackups = verify_reserved_gdb(sb, *primary)) < 0) {
465 : : err = gdbackups;
466 : : goto exit_bh;
467 : : }
468 : :
469 : : data = EXT3_I(inode)->i_data + EXT3_DIND_BLOCK;
470 : 0 : dind = sb_bread(sb, le32_to_cpu(*data));
471 [ # # ]: 0 : if (!dind) {
472 : : err = -EIO;
473 : : goto exit_bh;
474 : : }
475 : :
476 : 0 : data = (__le32 *)dind->b_data;
477 [ # # ]: 0 : if (le32_to_cpu(data[gdb_num % EXT3_ADDR_PER_BLOCK(sb)]) != gdblock) {
478 : 0 : ext3_warning(sb, __func__,
479 : : "new group %u GDT block "E3FSBLK" not reserved",
480 : : input->group, gdblock);
481 : : err = -EINVAL;
482 : : goto exit_dind;
483 : : }
484 : :
485 [ # # ]: 0 : if ((err = ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh)))
486 : : goto exit_dind;
487 : :
488 [ # # ]: 0 : if ((err = ext3_journal_get_write_access(handle, *primary)))
489 : : goto exit_sbh;
490 : :
491 [ # # ]: 0 : if ((err = ext3_journal_get_write_access(handle, dind)))
492 : : goto exit_primary;
493 : :
494 : : /* ext3_reserve_inode_write() gets a reference on the iloc */
495 [ # # ]: 0 : if ((err = ext3_reserve_inode_write(handle, inode, &iloc)))
496 : : goto exit_dindj;
497 : :
498 : 0 : n_group_desc = kmalloc((gdb_num + 1) * sizeof(struct buffer_head *),
499 : : GFP_NOFS);
500 [ # # ]: 0 : if (!n_group_desc) {
501 : : err = -ENOMEM;
502 : 0 : ext3_warning (sb, __func__,
503 : : "not enough memory for %lu groups", gdb_num + 1);
504 : : goto exit_inode;
505 : : }
506 : :
507 : : /*
508 : : * Finally, we have all of the possible failures behind us...
509 : : *
510 : : * Remove new GDT block from inode double-indirect block and clear out
511 : : * the new GDT block for use (which also "frees" the backup GDT blocks
512 : : * from the reserved inode). We don't need to change the bitmaps for
513 : : * these blocks, because they are marked as in-use from being in the
514 : : * reserved inode, and will become GDT blocks (primary and backup).
515 : : */
516 : 0 : data[gdb_num % EXT3_ADDR_PER_BLOCK(sb)] = 0;
517 : 0 : err = ext3_journal_dirty_metadata(handle, dind);
518 [ # # ]: 0 : if (err)
519 : : goto exit_group_desc;
520 : : brelse(dind);
521 : : dind = NULL;
522 : 0 : inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9;
523 : 0 : err = ext3_mark_iloc_dirty(handle, inode, &iloc);
524 [ # # ]: 0 : if (err)
525 : : goto exit_group_desc;
526 [ # # ]: 0 : memset((*primary)->b_data, 0, sb->s_blocksize);
527 : 0 : err = ext3_journal_dirty_metadata(handle, *primary);
528 [ # # ]: 0 : if (err)
529 : : goto exit_group_desc;
530 : :
531 : 0 : o_group_desc = EXT3_SB(sb)->s_group_desc;
532 : 0 : memcpy(n_group_desc, o_group_desc,
533 : 0 : EXT3_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
534 : 0 : n_group_desc[gdb_num] = *primary;
535 : 0 : EXT3_SB(sb)->s_group_desc = n_group_desc;
536 : 0 : EXT3_SB(sb)->s_gdb_count++;
537 : 0 : kfree(o_group_desc);
538 : :
539 : : le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
540 : 0 : err = ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
541 [ # # ]: 0 : if (err)
542 : : goto exit_inode;
543 : :
544 : : return 0;
545 : :
546 : : exit_group_desc:
547 : 0 : kfree(n_group_desc);
548 : : exit_inode:
549 : : //ext3_journal_release_buffer(handle, iloc.bh);
550 : 0 : brelse(iloc.bh);
551 : : exit_dindj:
552 : : //ext3_journal_release_buffer(handle, dind);
553 : : exit_primary:
554 : : //ext3_journal_release_buffer(handle, *primary);
555 : : exit_sbh:
556 : : //ext3_journal_release_buffer(handle, *primary);
557 : : exit_dind:
558 : : brelse(dind);
559 : : exit_bh:
560 : 0 : brelse(*primary);
561 : :
562 : : ext3_debug("leaving with error %d\n", err);
563 : : return err;
564 : : }
565 : :
566 : : /*
567 : : * Called when we are adding a new group which has a backup copy of each of
568 : : * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
569 : : * We need to add these reserved backup GDT blocks to the resize inode, so
570 : : * that they are kept for future resizing and not allocated to files.
571 : : *
572 : : * Each reserved backup GDT block will go into a different indirect block.
573 : : * The indirect blocks are actually the primary reserved GDT blocks,
574 : : * so we know in advance what their block numbers are. We only get the
575 : : * double-indirect block to verify it is pointing to the primary reserved
576 : : * GDT blocks so we don't overwrite a data block by accident. The reserved
577 : : * backup GDT blocks are stored in their reserved primary GDT block.
578 : : */
579 : 0 : static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
580 : : struct ext3_new_group_data *input)
581 : : {
582 : 0 : struct super_block *sb = inode->i_sb;
583 : 0 : int reserved_gdb =le16_to_cpu(EXT3_SB(sb)->s_es->s_reserved_gdt_blocks);
584 : : struct buffer_head **primary;
585 : : struct buffer_head *dind;
586 : : struct ext3_iloc iloc;
587 : : ext3_fsblk_t blk;
588 : : __le32 *data, *end;
589 : : int gdbackups = 0;
590 : : int res, i;
591 : : int err;
592 : :
593 : 0 : primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS);
594 [ # # ]: 0 : if (!primary)
595 : : return -ENOMEM;
596 : :
597 : : data = EXT3_I(inode)->i_data + EXT3_DIND_BLOCK;
598 : 0 : dind = sb_bread(sb, le32_to_cpu(*data));
599 [ # # ]: 0 : if (!dind) {
600 : : err = -EIO;
601 : : goto exit_free;
602 : : }
603 : :
604 : 0 : blk = EXT3_SB(sb)->s_sbh->b_blocknr + 1 + EXT3_SB(sb)->s_gdb_count;
605 : 0 : data = (__le32 *)dind->b_data + (EXT3_SB(sb)->s_gdb_count %
606 : 0 : EXT3_ADDR_PER_BLOCK(sb));
607 : 0 : end = (__le32 *)dind->b_data + EXT3_ADDR_PER_BLOCK(sb);
608 : :
609 : : /* Get each reserved primary GDT block and verify it holds backups */
610 [ # # ]: 0 : for (res = 0; res < reserved_gdb; res++, blk++) {
611 [ # # ]: 0 : if (le32_to_cpu(*data) != blk) {
612 : 0 : ext3_warning(sb, __func__,
613 : : "reserved block "E3FSBLK
614 : : " not at offset %ld",
615 : : blk,
616 : 0 : (long)(data - (__le32 *)dind->b_data));
617 : : err = -EINVAL;
618 : : goto exit_bh;
619 : : }
620 : 0 : primary[res] = sb_bread(sb, blk);
621 [ # # ]: 0 : if (!primary[res]) {
622 : : err = -EIO;
623 : : goto exit_bh;
624 : : }
625 [ # # ]: 0 : if ((gdbackups = verify_reserved_gdb(sb, primary[res])) < 0) {
626 : 0 : brelse(primary[res]);
627 : : err = gdbackups;
628 : : goto exit_bh;
629 : : }
630 [ # # ]: 0 : if (++data >= end)
631 : 0 : data = (__le32 *)dind->b_data;
632 : : }
633 : :
634 [ # # ]: 0 : for (i = 0; i < reserved_gdb; i++) {
635 [ # # ]: 0 : if ((err = ext3_journal_get_write_access(handle, primary[i]))) {
636 : : /*
637 : : int j;
638 : : for (j = 0; j < i; j++)
639 : : ext3_journal_release_buffer(handle, primary[j]);
640 : : */
641 : : goto exit_bh;
642 : : }
643 : : }
644 : :
645 [ # # ]: 0 : if ((err = ext3_reserve_inode_write(handle, inode, &iloc)))
646 : : goto exit_bh;
647 : :
648 : : /*
649 : : * Finally we can add each of the reserved backup GDT blocks from
650 : : * the new group to its reserved primary GDT block.
651 : : */
652 : 0 : blk = input->group * EXT3_BLOCKS_PER_GROUP(sb);
653 [ # # ]: 0 : for (i = 0; i < reserved_gdb; i++) {
654 : : int err2;
655 : 0 : data = (__le32 *)primary[i]->b_data;
656 : : /* printk("reserving backup %lu[%u] = %lu\n",
657 : : primary[i]->b_blocknr, gdbackups,
658 : : blk + primary[i]->b_blocknr); */
659 : 0 : data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
660 : 0 : err2 = ext3_journal_dirty_metadata(handle, primary[i]);
661 [ # # ]: 0 : if (!err)
662 : : err = err2;
663 : : }
664 : 0 : inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9;
665 : 0 : ext3_mark_iloc_dirty(handle, inode, &iloc);
666 : :
667 : : exit_bh:
668 [ # # ]: 0 : while (--res >= 0)
669 : 0 : brelse(primary[res]);
670 : : brelse(dind);
671 : :
672 : : exit_free:
673 : 0 : kfree(primary);
674 : :
675 : : return err;
676 : : }
677 : :
678 : : /*
679 : : * Update the backup copies of the ext3 metadata. These don't need to be part
680 : : * of the main resize transaction, because e2fsck will re-write them if there
681 : : * is a problem (basically only OOM will cause a problem). However, we
682 : : * _should_ update the backups if possible, in case the primary gets trashed
683 : : * for some reason and we need to run e2fsck from a backup superblock. The
684 : : * important part is that the new block and inode counts are in the backup
685 : : * superblocks, and the location of the new group metadata in the GDT backups.
686 : : *
687 : : * We do not need take the s_resize_lock for this, because these
688 : : * blocks are not otherwise touched by the filesystem code when it is
689 : : * mounted. We don't need to worry about last changing from
690 : : * sbi->s_groups_count, because the worst that can happen is that we
691 : : * do not copy the full number of backups at this time. The resize
692 : : * which changed s_groups_count will backup again.
693 : : */
694 : 0 : static void update_backups(struct super_block *sb,
695 : : int blk_off, char *data, int size)
696 : : {
697 : : struct ext3_sb_info *sbi = EXT3_SB(sb);
698 : 0 : const unsigned long last = sbi->s_groups_count;
699 : 0 : const int bpg = EXT3_BLOCKS_PER_GROUP(sb);
700 : 0 : unsigned three = 1;
701 : 0 : unsigned five = 5;
702 : 0 : unsigned seven = 7;
703 : : unsigned group;
704 : 0 : int rest = sb->s_blocksize - size;
705 : : handle_t *handle;
706 : : int err = 0, err2;
707 : :
708 : 0 : handle = ext3_journal_start_sb(sb, EXT3_MAX_TRANS_DATA);
709 [ # # ]: 0 : if (IS_ERR(handle)) {
710 : : group = 1;
711 : : err = PTR_ERR(handle);
712 : 0 : goto exit_err;
713 : : }
714 : :
715 [ # # ]: 0 : while ((group = ext3_list_backups(sb, &three, &five, &seven)) < last) {
716 : : struct buffer_head *bh;
717 : :
718 : : /* Out of journal space, and can't get more - abort - so sad */
719 [ # # # # ]: 0 : if (handle->h_buffer_credits == 0 &&
720 [ # # ]: 0 : ext3_journal_extend(handle, EXT3_MAX_TRANS_DATA) &&
721 : : (err = ext3_journal_restart(handle, EXT3_MAX_TRANS_DATA)))
722 : : break;
723 : :
724 : 0 : bh = sb_getblk(sb, group * bpg + blk_off);
725 [ # # ]: 0 : if (unlikely(!bh)) {
726 : : err = -ENOMEM;
727 : : break;
728 : : }
729 : : ext3_debug("update metadata backup %#04lx\n",
730 : : (unsigned long)bh->b_blocknr);
731 [ # # ]: 0 : if ((err = ext3_journal_get_write_access(handle, bh))) {
732 : : brelse(bh);
733 : : break;
734 : : }
735 : : lock_buffer(bh);
736 : 0 : memcpy(bh->b_data, data, size);
737 [ # # ]: 0 : if (rest)
738 [ # # ]: 0 : memset(bh->b_data + size, 0, rest);
739 : : set_buffer_uptodate(bh);
740 : 0 : unlock_buffer(bh);
741 : 0 : err = ext3_journal_dirty_metadata(handle, bh);
742 : : brelse(bh);
743 [ # # ]: 0 : if (err)
744 : : break;
745 : : }
746 [ # # ][ # # ]: 0 : if ((err2 = ext3_journal_stop(handle)) && !err)
747 : : err = err2;
748 : :
749 : : /*
750 : : * Ugh! Need to have e2fsck write the backup copies. It is too
751 : : * late to revert the resize, we shouldn't fail just because of
752 : : * the backup copies (they are only needed in case of corruption).
753 : : *
754 : : * However, if we got here we have a journal problem too, so we
755 : : * can't really start a transaction to mark the superblock.
756 : : * Chicken out and just set the flag on the hope it will be written
757 : : * to disk, and if not - we will simply wait until next fsck.
758 : : */
759 : : exit_err:
760 [ # # ]: 0 : if (err) {
761 : 0 : ext3_warning(sb, __func__,
762 : : "can't update backup for group %d (err %d), "
763 : : "forcing fsck on next reboot", group, err);
764 : 0 : sbi->s_mount_state &= ~EXT3_VALID_FS;
765 : 0 : sbi->s_es->s_state &= cpu_to_le16(~EXT3_VALID_FS);
766 : 0 : mark_buffer_dirty(sbi->s_sbh);
767 : : }
768 : 0 : }
769 : :
770 : : /* Add group descriptor data to an existing or new group descriptor block.
771 : : * Ensure we handle all possible error conditions _before_ we start modifying
772 : : * the filesystem, because we cannot abort the transaction and not have it
773 : : * write the data to disk.
774 : : *
775 : : * If we are on a GDT block boundary, we need to get the reserved GDT block.
776 : : * Otherwise, we may need to add backup GDT blocks for a sparse group.
777 : : *
778 : : * We only need to hold the superblock lock while we are actually adding
779 : : * in the new group's counts to the superblock. Prior to that we have
780 : : * not really "added" the group at all. We re-check that we are still
781 : : * adding in the last group in case things have changed since verifying.
782 : : */
783 : 0 : int ext3_group_add(struct super_block *sb, struct ext3_new_group_data *input)
784 : : {
785 : : struct ext3_sb_info *sbi = EXT3_SB(sb);
786 : 0 : struct ext3_super_block *es = sbi->s_es;
787 : 0 : int reserved_gdb = ext3_bg_has_super(sb, input->group) ?
788 [ # # ]: 0 : le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
789 : 0 : struct buffer_head *primary = NULL;
790 : : struct ext3_group_desc *gdp;
791 : : struct inode *inode = NULL;
792 : : handle_t *handle;
793 : : int gdb_off, gdb_num;
794 : : int err, err2;
795 : :
796 : 0 : gdb_num = input->group / EXT3_DESC_PER_BLOCK(sb);
797 : 0 : gdb_off = input->group % EXT3_DESC_PER_BLOCK(sb);
798 : :
799 [ # # ][ # # ]: 0 : if (gdb_off == 0 && !EXT3_HAS_RO_COMPAT_FEATURE(sb,
800 : : EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
801 : 0 : ext3_warning(sb, __func__,
802 : : "Can't resize non-sparse filesystem further");
803 : 0 : return -EPERM;
804 : : }
805 : :
806 [ # # ]: 0 : if (le32_to_cpu(es->s_blocks_count) + input->blocks_count <
807 : : le32_to_cpu(es->s_blocks_count)) {
808 : 0 : ext3_warning(sb, __func__, "blocks_count overflow\n");
809 : 0 : return -EINVAL;
810 : : }
811 : :
812 [ # # ]: 0 : if (le32_to_cpu(es->s_inodes_count) + EXT3_INODES_PER_GROUP(sb) <
813 : : le32_to_cpu(es->s_inodes_count)) {
814 : 0 : ext3_warning(sb, __func__, "inodes_count overflow\n");
815 : 0 : return -EINVAL;
816 : : }
817 : :
818 [ # # ]: 0 : if (reserved_gdb || gdb_off == 0) {
819 [ # # ]: 0 : if (!EXT3_HAS_COMPAT_FEATURE(sb,
820 : : EXT3_FEATURE_COMPAT_RESIZE_INODE)
821 [ # # ]: 0 : || !le16_to_cpu(es->s_reserved_gdt_blocks)) {
822 : 0 : ext3_warning(sb, __func__,
823 : : "No reserved GDT blocks, can't resize");
824 : 0 : return -EPERM;
825 : : }
826 : 0 : inode = ext3_iget(sb, EXT3_RESIZE_INO);
827 [ # # ]: 0 : if (IS_ERR(inode)) {
828 : 0 : ext3_warning(sb, __func__,
829 : : "Error opening resize inode");
830 : 0 : return PTR_ERR(inode);
831 : : }
832 : : }
833 : :
834 [ # # ]: 0 : if ((err = verify_group_input(sb, input)))
835 : : goto exit_put;
836 : :
837 [ # # ]: 0 : if ((err = setup_new_group_blocks(sb, input)))
838 : : goto exit_put;
839 : :
840 : : /*
841 : : * We will always be modifying at least the superblock and a GDT
842 : : * block. If we are adding a group past the last current GDT block,
843 : : * we will also modify the inode and the dindirect block. If we
844 : : * are adding a group with superblock/GDT backups we will also
845 : : * modify each of the reserved GDT dindirect blocks.
846 : : */
847 [ # # ]: 0 : handle = ext3_journal_start_sb(sb,
848 : 0 : ext3_bg_has_super(sb, input->group) ?
849 : : 3 + reserved_gdb : 4);
850 [ # # ]: 0 : if (IS_ERR(handle)) {
851 : : err = PTR_ERR(handle);
852 : 0 : goto exit_put;
853 : : }
854 : :
855 : 0 : mutex_lock(&sbi->s_resize_lock);
856 [ # # ]: 0 : if (input->group != sbi->s_groups_count) {
857 : 0 : ext3_warning(sb, __func__,
858 : : "multiple resizers run on filesystem!");
859 : : err = -EBUSY;
860 : 0 : goto exit_journal;
861 : : }
862 : :
863 [ # # ]: 0 : if ((err = ext3_journal_get_write_access(handle, sbi->s_sbh)))
864 : : goto exit_journal;
865 : :
866 : : /*
867 : : * We will only either add reserved group blocks to a backup group
868 : : * or remove reserved blocks for the first group in a new group block.
869 : : * Doing both would be mean more complex code, and sane people don't
870 : : * use non-sparse filesystems anymore. This is already checked above.
871 : : */
872 [ # # ]: 0 : if (gdb_off) {
873 : 0 : primary = sbi->s_group_desc[gdb_num];
874 [ # # ]: 0 : if ((err = ext3_journal_get_write_access(handle, primary)))
875 : : goto exit_journal;
876 : :
877 [ # # ][ # # ]: 0 : if (reserved_gdb && ext3_bg_num_gdb(sb, input->group) &&
[ # # ]
878 : : (err = reserve_backup_gdb(handle, inode, input)))
879 : : goto exit_journal;
880 [ # # ]: 0 : } else if ((err = add_new_gdb(handle, inode, input, &primary)))
881 : : goto exit_journal;
882 : :
883 : : /*
884 : : * OK, now we've set up the new group. Time to make it active.
885 : : *
886 : : * We do not lock all allocations via s_resize_lock
887 : : * so we have to be safe wrt. concurrent accesses the group
888 : : * data. So we need to be careful to set all of the relevant
889 : : * group descriptor data etc. *before* we enable the group.
890 : : *
891 : : * The key field here is sbi->s_groups_count: as long as
892 : : * that retains its old value, nobody is going to access the new
893 : : * group.
894 : : *
895 : : * So first we update all the descriptor metadata for the new
896 : : * group; then we update the total disk blocks count; then we
897 : : * update the groups count to enable the group; then finally we
898 : : * update the free space counts so that the system can start
899 : : * using the new disk blocks.
900 : : */
901 : :
902 : : /* Update group descriptor block for new group */
903 : 0 : gdp = (struct ext3_group_desc *)primary->b_data + gdb_off;
904 : :
905 : 0 : gdp->bg_block_bitmap = cpu_to_le32(input->block_bitmap);
906 : 0 : gdp->bg_inode_bitmap = cpu_to_le32(input->inode_bitmap);
907 : 0 : gdp->bg_inode_table = cpu_to_le32(input->inode_table);
908 : 0 : gdp->bg_free_blocks_count = cpu_to_le16(input->free_blocks_count);
909 : 0 : gdp->bg_free_inodes_count = cpu_to_le16(EXT3_INODES_PER_GROUP(sb));
910 : :
911 : : /*
912 : : * Make the new blocks and inodes valid next. We do this before
913 : : * increasing the group count so that once the group is enabled,
914 : : * all of its blocks and inodes are already valid.
915 : : *
916 : : * We always allocate group-by-group, then block-by-block or
917 : : * inode-by-inode within a group, so enabling these
918 : : * blocks/inodes before the group is live won't actually let us
919 : : * allocate the new space yet.
920 : : */
921 : 0 : le32_add_cpu(&es->s_blocks_count, input->blocks_count);
922 : 0 : le32_add_cpu(&es->s_inodes_count, EXT3_INODES_PER_GROUP(sb));
923 : :
924 : : /*
925 : : * We need to protect s_groups_count against other CPUs seeing
926 : : * inconsistent state in the superblock.
927 : : *
928 : : * The precise rules we use are:
929 : : *
930 : : * * Writers of s_groups_count *must* hold s_resize_lock
931 : : * AND
932 : : * * Writers must perform a smp_wmb() after updating all dependent
933 : : * data and before modifying the groups count
934 : : *
935 : : * * Readers must hold s_resize_lock over the access
936 : : * OR
937 : : * * Readers must perform an smp_rmb() after reading the groups count
938 : : * and before reading any dependent data.
939 : : *
940 : : * NB. These rules can be relaxed when checking the group count
941 : : * while freeing data, as we can only allocate from a block
942 : : * group after serialising against the group count, and we can
943 : : * only then free after serialising in turn against that
944 : : * allocation.
945 : : */
946 : 0 : smp_wmb();
947 : :
948 : : /* Update the global fs size fields */
949 : 0 : sbi->s_groups_count++;
950 : :
951 : 0 : err = ext3_journal_dirty_metadata(handle, primary);
952 [ # # ]: 0 : if (err)
953 : : goto exit_journal;
954 : :
955 : : /* Update the reserved block counts only once the new group is
956 : : * active. */
957 : 0 : le32_add_cpu(&es->s_r_blocks_count, input->reserved_blocks);
958 : :
959 : : /* Update the free space counts */
960 : 0 : percpu_counter_add(&sbi->s_freeblocks_counter,
961 : 0 : input->free_blocks_count);
962 : 0 : percpu_counter_add(&sbi->s_freeinodes_counter,
963 : 0 : EXT3_INODES_PER_GROUP(sb));
964 : :
965 : 0 : err = ext3_journal_dirty_metadata(handle, sbi->s_sbh);
966 : :
967 : : exit_journal:
968 : 0 : mutex_unlock(&sbi->s_resize_lock);
969 [ # # ][ # # ]: 0 : if ((err2 = ext3_journal_stop(handle)) && !err)
970 : : err = err2;
971 [ # # ]: 0 : if (!err) {
972 : 0 : update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
973 : : sizeof(struct ext3_super_block));
974 : 0 : update_backups(sb, primary->b_blocknr, primary->b_data,
975 : 0 : primary->b_size);
976 : : }
977 : : exit_put:
978 : 0 : iput(inode);
979 : 0 : return err;
980 : : } /* ext3_group_add */
981 : :
982 : : /* Extend the filesystem to the new number of blocks specified. This entry
983 : : * point is only used to extend the current filesystem to the end of the last
984 : : * existing group. It can be accessed via ioctl, or by "remount,resize=<size>"
985 : : * for emergencies (because it has no dependencies on reserved blocks).
986 : : *
987 : : * If we _really_ wanted, we could use default values to call ext3_group_add()
988 : : * allow the "remount" trick to work for arbitrary resizing, assuming enough
989 : : * GDT blocks are reserved to grow to the desired size.
990 : : */
991 : 0 : int ext3_group_extend(struct super_block *sb, struct ext3_super_block *es,
992 : : ext3_fsblk_t n_blocks_count)
993 : : {
994 : : ext3_fsblk_t o_blocks_count;
995 : : ext3_grpblk_t last;
996 : : ext3_grpblk_t add;
997 : : struct buffer_head * bh;
998 : : handle_t *handle;
999 : : int err;
1000 : : unsigned long freed_blocks;
1001 : :
1002 : : /* We don't need to worry about locking wrt other resizers just
1003 : : * yet: we're going to revalidate es->s_blocks_count after
1004 : : * taking the s_resize_lock below. */
1005 : 0 : o_blocks_count = le32_to_cpu(es->s_blocks_count);
1006 : :
1007 [ # # ]: 0 : if (test_opt(sb, DEBUG))
1008 : 0 : printk(KERN_DEBUG "EXT3-fs: extending last group from "E3FSBLK
1009 : : " up to "E3FSBLK" blocks\n",
1010 : : o_blocks_count, n_blocks_count);
1011 : :
1012 [ # # ]: 0 : if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
1013 : : return 0;
1014 : :
1015 [ # # ]: 0 : if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1016 : 0 : printk(KERN_ERR "EXT3-fs: filesystem on %s:"
1017 : : " too large to resize to "E3FSBLK" blocks safely\n",
1018 : 0 : sb->s_id, n_blocks_count);
1019 : : if (sizeof(sector_t) < 8)
1020 : : ext3_warning(sb, __func__,
1021 : : "CONFIG_LBDAF not enabled\n");
1022 : 0 : return -EINVAL;
1023 : : }
1024 : :
1025 [ # # ]: 0 : if (n_blocks_count < o_blocks_count) {
1026 : 0 : ext3_warning(sb, __func__,
1027 : : "can't shrink FS - resize aborted");
1028 : 0 : return -EBUSY;
1029 : : }
1030 : :
1031 : : /* Handle the remaining blocks in the last group only. */
1032 : 0 : last = (o_blocks_count - le32_to_cpu(es->s_first_data_block)) %
1033 : 0 : EXT3_BLOCKS_PER_GROUP(sb);
1034 : :
1035 [ # # ]: 0 : if (last == 0) {
1036 : 0 : ext3_warning(sb, __func__,
1037 : : "need to use ext2online to resize further");
1038 : 0 : return -EPERM;
1039 : : }
1040 : :
1041 : 0 : add = EXT3_BLOCKS_PER_GROUP(sb) - last;
1042 : :
1043 [ # # ]: 0 : if (o_blocks_count + add < o_blocks_count) {
1044 : 0 : ext3_warning(sb, __func__, "blocks_count overflow");
1045 : 0 : return -EINVAL;
1046 : : }
1047 : :
1048 [ # # ]: 0 : if (o_blocks_count + add > n_blocks_count)
1049 : 0 : add = n_blocks_count - o_blocks_count;
1050 : :
1051 [ # # ]: 0 : if (o_blocks_count + add < n_blocks_count)
1052 : 0 : ext3_warning(sb, __func__,
1053 : : "will only finish group ("E3FSBLK
1054 : : " blocks, %u new)",
1055 : : o_blocks_count + add, add);
1056 : :
1057 : : /* See if the device is actually as big as what was requested */
1058 : 0 : bh = sb_bread(sb, o_blocks_count + add -1);
1059 [ # # ]: 0 : if (!bh) {
1060 : 0 : ext3_warning(sb, __func__,
1061 : : "can't read last block, resize aborted");
1062 : 0 : return -ENOSPC;
1063 : : }
1064 : : brelse(bh);
1065 : :
1066 : : /* We will update the superblock, one block bitmap, and
1067 : : * one group descriptor via ext3_free_blocks().
1068 : : */
1069 : 0 : handle = ext3_journal_start_sb(sb, 3);
1070 [ # # ]: 0 : if (IS_ERR(handle)) {
1071 : : err = PTR_ERR(handle);
1072 : 0 : ext3_warning(sb, __func__, "error %d on journal start",err);
1073 : 0 : goto exit_put;
1074 : : }
1075 : :
1076 : 0 : mutex_lock(&EXT3_SB(sb)->s_resize_lock);
1077 [ # # ]: 0 : if (o_blocks_count != le32_to_cpu(es->s_blocks_count)) {
1078 : 0 : ext3_warning(sb, __func__,
1079 : : "multiple resizers run on filesystem!");
1080 : 0 : mutex_unlock(&EXT3_SB(sb)->s_resize_lock);
1081 : 0 : ext3_journal_stop(handle);
1082 : : err = -EBUSY;
1083 : 0 : goto exit_put;
1084 : : }
1085 : :
1086 [ # # ]: 0 : if ((err = ext3_journal_get_write_access(handle,
1087 : : EXT3_SB(sb)->s_sbh))) {
1088 : 0 : ext3_warning(sb, __func__,
1089 : : "error %d on journal write access", err);
1090 : 0 : mutex_unlock(&EXT3_SB(sb)->s_resize_lock);
1091 : 0 : ext3_journal_stop(handle);
1092 : 0 : goto exit_put;
1093 : : }
1094 : 0 : es->s_blocks_count = cpu_to_le32(o_blocks_count + add);
1095 : 0 : err = ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
1096 : 0 : mutex_unlock(&EXT3_SB(sb)->s_resize_lock);
1097 [ # # ]: 0 : if (err) {
1098 : 0 : ext3_warning(sb, __func__,
1099 : : "error %d on journal dirty metadata", err);
1100 : 0 : ext3_journal_stop(handle);
1101 : 0 : goto exit_put;
1102 : : }
1103 : : ext3_debug("freeing blocks "E3FSBLK" through "E3FSBLK"\n",
1104 : : o_blocks_count, o_blocks_count + add);
1105 : 0 : ext3_free_blocks_sb(handle, sb, o_blocks_count, add, &freed_blocks);
1106 : : ext3_debug("freed blocks "E3FSBLK" through "E3FSBLK"\n",
1107 : : o_blocks_count, o_blocks_count + add);
1108 [ # # ]: 0 : if ((err = ext3_journal_stop(handle)))
1109 : : goto exit_put;
1110 [ # # ]: 0 : if (test_opt(sb, DEBUG))
1111 : 0 : printk(KERN_DEBUG "EXT3-fs: extended group to %u blocks\n",
1112 : : le32_to_cpu(es->s_blocks_count));
1113 : 0 : update_backups(sb, EXT3_SB(sb)->s_sbh->b_blocknr, (char *)es,
1114 : : sizeof(struct ext3_super_block));
1115 : : exit_put:
1116 : 0 : return err;
1117 : : } /* ext3_group_extend */
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