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1/*
2 * linux/fs/ext4/resize.c
3 *
4 * Support for resizing an ext4 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 EXT4FS_DEBUG
13
14#include <linux/errno.h>
15#include <linux/slab.h>
16
17#include "ext4_jbd2.h"
18
19int ext4_resize_begin(struct super_block *sb)
20{
21 int ret = 0;
22
23 if (!capable(CAP_SYS_RESOURCE))
24 return -EPERM;
25
26 /*
27 * We are not allowed to do online-resizing on a filesystem mounted
28 * with error, because it can destroy the filesystem easily.
29 */
30 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
31 ext4_warning(sb, "There are errors in the filesystem, "
32 "so online resizing is not allowed\n");
33 return -EPERM;
34 }
35
36 if (test_and_set_bit_lock(EXT4_RESIZING, &EXT4_SB(sb)->s_resize_flags))
37 ret = -EBUSY;
38
39 return ret;
40}
41
42void ext4_resize_end(struct super_block *sb)
43{
44 clear_bit_unlock(EXT4_RESIZING, &EXT4_SB(sb)->s_resize_flags);
45 smp_mb__after_clear_bit();
46}
47
48#define outside(b, first, last) ((b) < (first) || (b) >= (last))
49#define inside(b, first, last) ((b) >= (first) && (b) < (last))
50
51static int verify_group_input(struct super_block *sb,
52 struct ext4_new_group_data *input)
53{
54 struct ext4_sb_info *sbi = EXT4_SB(sb);
55 struct ext4_super_block *es = sbi->s_es;
56 ext4_fsblk_t start = ext4_blocks_count(es);
57 ext4_fsblk_t end = start + input->blocks_count;
58 ext4_group_t group = input->group;
59 ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
60 unsigned overhead = ext4_bg_has_super(sb, group) ?
61 (1 + ext4_bg_num_gdb(sb, group) +
62 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
63 ext4_fsblk_t metaend = start + overhead;
64 struct buffer_head *bh = NULL;
65 ext4_grpblk_t free_blocks_count, offset;
66 int err = -EINVAL;
67
68 input->free_blocks_count = free_blocks_count =
69 input->blocks_count - 2 - overhead - sbi->s_itb_per_group;
70
71 if (test_opt(sb, DEBUG))
72 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks "
73 "(%d free, %u reserved)\n",
74 ext4_bg_has_super(sb, input->group) ? "normal" :
75 "no-super", input->group, input->blocks_count,
76 free_blocks_count, input->reserved_blocks);
77
78 ext4_get_group_no_and_offset(sb, start, NULL, &offset);
79 if (group != sbi->s_groups_count)
80 ext4_warning(sb, "Cannot add at group %u (only %u groups)",
81 input->group, sbi->s_groups_count);
82 else if (offset != 0)
83 ext4_warning(sb, "Last group not full");
84 else if (input->reserved_blocks > input->blocks_count / 5)
85 ext4_warning(sb, "Reserved blocks too high (%u)",
86 input->reserved_blocks);
87 else if (free_blocks_count < 0)
88 ext4_warning(sb, "Bad blocks count %u",
89 input->blocks_count);
90 else if (!(bh = sb_bread(sb, end - 1)))
91 ext4_warning(sb, "Cannot read last block (%llu)",
92 end - 1);
93 else if (outside(input->block_bitmap, start, end))
94 ext4_warning(sb, "Block bitmap not in group (block %llu)",
95 (unsigned long long)input->block_bitmap);
96 else if (outside(input->inode_bitmap, start, end))
97 ext4_warning(sb, "Inode bitmap not in group (block %llu)",
98 (unsigned long long)input->inode_bitmap);
99 else if (outside(input->inode_table, start, end) ||
100 outside(itend - 1, start, end))
101 ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)",
102 (unsigned long long)input->inode_table, itend - 1);
103 else if (input->inode_bitmap == input->block_bitmap)
104 ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)",
105 (unsigned long long)input->block_bitmap);
106 else if (inside(input->block_bitmap, input->inode_table, itend))
107 ext4_warning(sb, "Block bitmap (%llu) in inode table "
108 "(%llu-%llu)",
109 (unsigned long long)input->block_bitmap,
110 (unsigned long long)input->inode_table, itend - 1);
111 else if (inside(input->inode_bitmap, input->inode_table, itend))
112 ext4_warning(sb, "Inode bitmap (%llu) in inode table "
113 "(%llu-%llu)",
114 (unsigned long long)input->inode_bitmap,
115 (unsigned long long)input->inode_table, itend - 1);
116 else if (inside(input->block_bitmap, start, metaend))
117 ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)",
118 (unsigned long long)input->block_bitmap,
119 start, metaend - 1);
120 else if (inside(input->inode_bitmap, start, metaend))
121 ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)",
122 (unsigned long long)input->inode_bitmap,
123 start, metaend - 1);
124 else if (inside(input->inode_table, start, metaend) ||
125 inside(itend - 1, start, metaend))
126 ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table "
127 "(%llu-%llu)",
128 (unsigned long long)input->inode_table,
129 itend - 1, start, metaend - 1);
130 else
131 err = 0;
132 brelse(bh);
133
134 return err;
135}
136
137static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
138 ext4_fsblk_t blk)
139{
140 struct buffer_head *bh;
141 int err;
142
143 bh = sb_getblk(sb, blk);
144 if (!bh)
145 return ERR_PTR(-EIO);
146 if ((err = ext4_journal_get_write_access(handle, bh))) {
147 brelse(bh);
148 bh = ERR_PTR(err);
149 } else {
150 memset(bh->b_data, 0, sb->s_blocksize);
151 set_buffer_uptodate(bh);
152 }
153
154 return bh;
155}
156
157/*
158 * If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA.
159 * If that fails, restart the transaction & regain write access for the
160 * buffer head which is used for block_bitmap modifications.
161 */
162static int extend_or_restart_transaction(handle_t *handle, int thresh)
163{
164 int err;
165
166 if (ext4_handle_has_enough_credits(handle, thresh))
167 return 0;
168
169 err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA);
170 if (err < 0)
171 return err;
172 if (err) {
173 err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA);
174 if (err)
175 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 */
188static int setup_new_group_blocks(struct super_block *sb,
189 struct ext4_new_group_data *input)
190{
191 struct ext4_sb_info *sbi = EXT4_SB(sb);
192 ext4_fsblk_t start = ext4_group_first_block_no(sb, input->group);
193 int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
194 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0;
195 unsigned long gdblocks = ext4_bg_num_gdb(sb, input->group);
196 struct buffer_head *bh;
197 handle_t *handle;
198 ext4_fsblk_t block;
199 ext4_grpblk_t bit;
200 int i;
201 int err = 0, err2;
202
203 /* This transaction may be extended/restarted along the way */
204 handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
205
206 if (IS_ERR(handle))
207 return PTR_ERR(handle);
208
209 BUG_ON(input->group != sbi->s_groups_count);
210
211 /* Copy all of the GDT blocks into the backup in this group */
212 for (i = 0, bit = 1, block = start + 1;
213 i < gdblocks; i++, block++, bit++) {
214 struct buffer_head *gdb;
215
216 ext4_debug("update backup group %#04llx (+%d)\n", block, bit);
217 err = extend_or_restart_transaction(handle, 1);
218 if (err)
219 goto exit_journal;
220
221 gdb = sb_getblk(sb, block);
222 if (!gdb) {
223 err = -EIO;
224 goto exit_journal;
225 }
226 if ((err = ext4_journal_get_write_access(handle, gdb))) {
227 brelse(gdb);
228 goto exit_journal;
229 }
230 memcpy(gdb->b_data, sbi->s_group_desc[i]->b_data, gdb->b_size);
231 set_buffer_uptodate(gdb);
232 err = ext4_handle_dirty_metadata(handle, NULL, gdb);
233 if (unlikely(err)) {
234 brelse(gdb);
235 goto exit_journal;
236 }
237 brelse(gdb);
238 }
239
240 /* Zero out all of the reserved backup group descriptor table blocks */
241 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n",
242 block, sbi->s_itb_per_group);
243 err = sb_issue_zeroout(sb, gdblocks + start + 1, reserved_gdb,
244 GFP_NOFS);
245 if (err)
246 goto exit_journal;
247
248 err = extend_or_restart_transaction(handle, 2);
249 if (err)
250 goto exit_journal;
251
252 bh = bclean(handle, sb, input->block_bitmap);
253 if (IS_ERR(bh)) {
254 err = PTR_ERR(bh);
255 goto exit_journal;
256 }
257
258 if (ext4_bg_has_super(sb, input->group)) {
259 ext4_debug("mark backup group tables %#04llx (+0)\n", start);
260 ext4_set_bits(bh->b_data, 0, gdblocks + reserved_gdb + 1);
261 }
262
263 ext4_debug("mark block bitmap %#04llx (+%llu)\n", input->block_bitmap,
264 input->block_bitmap - start);
265 ext4_set_bit(input->block_bitmap - start, bh->b_data);
266 ext4_debug("mark inode bitmap %#04llx (+%llu)\n", input->inode_bitmap,
267 input->inode_bitmap - start);
268 ext4_set_bit(input->inode_bitmap - start, bh->b_data);
269
270 /* Zero out all of the inode table blocks */
271 block = input->inode_table;
272 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n",
273 block, sbi->s_itb_per_group);
274 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group, GFP_NOFS);
275 if (err)
276 goto exit_bh;
277 ext4_set_bits(bh->b_data, input->inode_table - start,
278 sbi->s_itb_per_group);
279
280
281 ext4_mark_bitmap_end(input->blocks_count, sb->s_blocksize * 8,
282 bh->b_data);
283 err = ext4_handle_dirty_metadata(handle, NULL, bh);
284 if (unlikely(err)) {
285 ext4_std_error(sb, err);
286 goto exit_bh;
287 }
288 brelse(bh);
289 /* Mark unused entries in inode bitmap used */
290 ext4_debug("clear inode bitmap %#04llx (+%llu)\n",
291 input->inode_bitmap, input->inode_bitmap - start);
292 if (IS_ERR(bh = bclean(handle, sb, input->inode_bitmap))) {
293 err = PTR_ERR(bh);
294 goto exit_journal;
295 }
296
297 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
298 bh->b_data);
299 err = ext4_handle_dirty_metadata(handle, NULL, bh);
300 if (unlikely(err))
301 ext4_std_error(sb, err);
302exit_bh:
303 brelse(bh);
304
305exit_journal:
306 if ((err2 = ext4_journal_stop(handle)) && !err)
307 err = err2;
308
309 return err;
310}
311
312/*
313 * Iterate through the groups which hold BACKUP superblock/GDT copies in an
314 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
315 * calling this for the first time. In a sparse filesystem it will be the
316 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
317 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
318 */
319static unsigned ext4_list_backups(struct super_block *sb, unsigned *three,
320 unsigned *five, unsigned *seven)
321{
322 unsigned *min = three;
323 int mult = 3;
324 unsigned ret;
325
326 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
327 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
328 ret = *min;
329 *min += 1;
330 return ret;
331 }
332
333 if (*five < *min) {
334 min = five;
335 mult = 5;
336 }
337 if (*seven < *min) {
338 min = seven;
339 mult = 7;
340 }
341
342 ret = *min;
343 *min *= mult;
344
345 return ret;
346}
347
348/*
349 * Check that all of the backup GDT blocks are held in the primary GDT block.
350 * It is assumed that they are stored in group order. Returns the number of
351 * groups in current filesystem that have BACKUPS, or -ve error code.
352 */
353static int verify_reserved_gdb(struct super_block *sb,
354 struct buffer_head *primary)
355{
356 const ext4_fsblk_t blk = primary->b_blocknr;
357 const ext4_group_t end = EXT4_SB(sb)->s_groups_count;
358 unsigned three = 1;
359 unsigned five = 5;
360 unsigned seven = 7;
361 unsigned grp;
362 __le32 *p = (__le32 *)primary->b_data;
363 int gdbackups = 0;
364
365 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) {
366 if (le32_to_cpu(*p++) !=
367 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){
368 ext4_warning(sb, "reserved GDT %llu"
369 " missing grp %d (%llu)",
370 blk, grp,
371 grp *
372 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
373 blk);
374 return -EINVAL;
375 }
376 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb))
377 return -EFBIG;
378 }
379
380 return gdbackups;
381}
382
383/*
384 * Called when we need to bring a reserved group descriptor table block into
385 * use from the resize inode. The primary copy of the new GDT block currently
386 * is an indirect block (under the double indirect block in the resize inode).
387 * The new backup GDT blocks will be stored as leaf blocks in this indirect
388 * block, in group order. Even though we know all the block numbers we need,
389 * we check to ensure that the resize inode has actually reserved these blocks.
390 *
391 * Don't need to update the block bitmaps because the blocks are still in use.
392 *
393 * We get all of the error cases out of the way, so that we are sure to not
394 * fail once we start modifying the data on disk, because JBD has no rollback.
395 */
396static int add_new_gdb(handle_t *handle, struct inode *inode,
397 ext4_group_t group)
398{
399 struct super_block *sb = inode->i_sb;
400 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
401 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
402 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
403 struct buffer_head **o_group_desc, **n_group_desc;
404 struct buffer_head *dind;
405 struct buffer_head *gdb_bh;
406 int gdbackups;
407 struct ext4_iloc iloc;
408 __le32 *data;
409 int err;
410
411 if (test_opt(sb, DEBUG))
412 printk(KERN_DEBUG
413 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
414 gdb_num);
415
416 /*
417 * If we are not using the primary superblock/GDT copy don't resize,
418 * because the user tools have no way of handling this. Probably a
419 * bad time to do it anyways.
420 */
421 if (EXT4_SB(sb)->s_sbh->b_blocknr !=
422 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
423 ext4_warning(sb, "won't resize using backup superblock at %llu",
424 (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
425 return -EPERM;
426 }
427
428 gdb_bh = sb_bread(sb, gdblock);
429 if (!gdb_bh)
430 return -EIO;
431
432 gdbackups = verify_reserved_gdb(sb, gdb_bh);
433 if (gdbackups < 0) {
434 err = gdbackups;
435 goto exit_bh;
436 }
437
438 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
439 dind = sb_bread(sb, le32_to_cpu(*data));
440 if (!dind) {
441 err = -EIO;
442 goto exit_bh;
443 }
444
445 data = (__le32 *)dind->b_data;
446 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) {
447 ext4_warning(sb, "new group %u GDT block %llu not reserved",
448 group, gdblock);
449 err = -EINVAL;
450 goto exit_dind;
451 }
452
453 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
454 if (unlikely(err))
455 goto exit_dind;
456
457 err = ext4_journal_get_write_access(handle, gdb_bh);
458 if (unlikely(err))
459 goto exit_sbh;
460
461 err = ext4_journal_get_write_access(handle, dind);
462 if (unlikely(err))
463 ext4_std_error(sb, err);
464
465 /* ext4_reserve_inode_write() gets a reference on the iloc */
466 err = ext4_reserve_inode_write(handle, inode, &iloc);
467 if (unlikely(err))
468 goto exit_dindj;
469
470 n_group_desc = ext4_kvmalloc((gdb_num + 1) *
471 sizeof(struct buffer_head *),
472 GFP_NOFS);
473 if (!n_group_desc) {
474 err = -ENOMEM;
475 ext4_warning(sb, "not enough memory for %lu groups",
476 gdb_num + 1);
477 goto exit_inode;
478 }
479
480 /*
481 * Finally, we have all of the possible failures behind us...
482 *
483 * Remove new GDT block from inode double-indirect block and clear out
484 * the new GDT block for use (which also "frees" the backup GDT blocks
485 * from the reserved inode). We don't need to change the bitmaps for
486 * these blocks, because they are marked as in-use from being in the
487 * reserved inode, and will become GDT blocks (primary and backup).
488 */
489 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0;
490 err = ext4_handle_dirty_metadata(handle, NULL, dind);
491 if (unlikely(err)) {
492 ext4_std_error(sb, err);
493 goto exit_inode;
494 }
495 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9;
496 ext4_mark_iloc_dirty(handle, inode, &iloc);
497 memset(gdb_bh->b_data, 0, sb->s_blocksize);
498 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
499 if (unlikely(err)) {
500 ext4_std_error(sb, err);
501 goto exit_inode;
502 }
503 brelse(dind);
504
505 o_group_desc = EXT4_SB(sb)->s_group_desc;
506 memcpy(n_group_desc, o_group_desc,
507 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
508 n_group_desc[gdb_num] = gdb_bh;
509 EXT4_SB(sb)->s_group_desc = n_group_desc;
510 EXT4_SB(sb)->s_gdb_count++;
511 ext4_kvfree(o_group_desc);
512
513 le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
514 err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
515 if (err)
516 ext4_std_error(sb, err);
517
518 return err;
519
520exit_inode:
521 ext4_kvfree(n_group_desc);
522 /* ext4_handle_release_buffer(handle, iloc.bh); */
523 brelse(iloc.bh);
524exit_dindj:
525 /* ext4_handle_release_buffer(handle, dind); */
526exit_sbh:
527 /* ext4_handle_release_buffer(handle, EXT4_SB(sb)->s_sbh); */
528exit_dind:
529 brelse(dind);
530exit_bh:
531 brelse(gdb_bh);
532
533 ext4_debug("leaving with error %d\n", err);
534 return err;
535}
536
537/*
538 * Called when we are adding a new group which has a backup copy of each of
539 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
540 * We need to add these reserved backup GDT blocks to the resize inode, so
541 * that they are kept for future resizing and not allocated to files.
542 *
543 * Each reserved backup GDT block will go into a different indirect block.
544 * The indirect blocks are actually the primary reserved GDT blocks,
545 * so we know in advance what their block numbers are. We only get the
546 * double-indirect block to verify it is pointing to the primary reserved
547 * GDT blocks so we don't overwrite a data block by accident. The reserved
548 * backup GDT blocks are stored in their reserved primary GDT block.
549 */
550static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
551 ext4_group_t group)
552{
553 struct super_block *sb = inode->i_sb;
554 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
555 struct buffer_head **primary;
556 struct buffer_head *dind;
557 struct ext4_iloc iloc;
558 ext4_fsblk_t blk;
559 __le32 *data, *end;
560 int gdbackups = 0;
561 int res, i;
562 int err;
563
564 primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS);
565 if (!primary)
566 return -ENOMEM;
567
568 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
569 dind = sb_bread(sb, le32_to_cpu(*data));
570 if (!dind) {
571 err = -EIO;
572 goto exit_free;
573 }
574
575 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count;
576 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count %
577 EXT4_ADDR_PER_BLOCK(sb));
578 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb);
579
580 /* Get each reserved primary GDT block and verify it holds backups */
581 for (res = 0; res < reserved_gdb; res++, blk++) {
582 if (le32_to_cpu(*data) != blk) {
583 ext4_warning(sb, "reserved block %llu"
584 " not at offset %ld",
585 blk,
586 (long)(data - (__le32 *)dind->b_data));
587 err = -EINVAL;
588 goto exit_bh;
589 }
590 primary[res] = sb_bread(sb, blk);
591 if (!primary[res]) {
592 err = -EIO;
593 goto exit_bh;
594 }
595 if ((gdbackups = verify_reserved_gdb(sb, primary[res])) < 0) {
596 brelse(primary[res]);
597 err = gdbackups;
598 goto exit_bh;
599 }
600 if (++data >= end)
601 data = (__le32 *)dind->b_data;
602 }
603
604 for (i = 0; i < reserved_gdb; i++) {
605 if ((err = ext4_journal_get_write_access(handle, primary[i]))) {
606 /*
607 int j;
608 for (j = 0; j < i; j++)
609 ext4_handle_release_buffer(handle, primary[j]);
610 */
611 goto exit_bh;
612 }
613 }
614
615 if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
616 goto exit_bh;
617
618 /*
619 * Finally we can add each of the reserved backup GDT blocks from
620 * the new group to its reserved primary GDT block.
621 */
622 blk = group * EXT4_BLOCKS_PER_GROUP(sb);
623 for (i = 0; i < reserved_gdb; i++) {
624 int err2;
625 data = (__le32 *)primary[i]->b_data;
626 /* printk("reserving backup %lu[%u] = %lu\n",
627 primary[i]->b_blocknr, gdbackups,
628 blk + primary[i]->b_blocknr); */
629 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
630 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]);
631 if (!err)
632 err = err2;
633 }
634 inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9;
635 ext4_mark_iloc_dirty(handle, inode, &iloc);
636
637exit_bh:
638 while (--res >= 0)
639 brelse(primary[res]);
640 brelse(dind);
641
642exit_free:
643 kfree(primary);
644
645 return err;
646}
647
648/*
649 * Update the backup copies of the ext4 metadata. These don't need to be part
650 * of the main resize transaction, because e2fsck will re-write them if there
651 * is a problem (basically only OOM will cause a problem). However, we
652 * _should_ update the backups if possible, in case the primary gets trashed
653 * for some reason and we need to run e2fsck from a backup superblock. The
654 * important part is that the new block and inode counts are in the backup
655 * superblocks, and the location of the new group metadata in the GDT backups.
656 *
657 * We do not need take the s_resize_lock for this, because these
658 * blocks are not otherwise touched by the filesystem code when it is
659 * mounted. We don't need to worry about last changing from
660 * sbi->s_groups_count, because the worst that can happen is that we
661 * do not copy the full number of backups at this time. The resize
662 * which changed s_groups_count will backup again.
663 */
664static void update_backups(struct super_block *sb,
665 int blk_off, char *data, int size)
666{
667 struct ext4_sb_info *sbi = EXT4_SB(sb);
668 const ext4_group_t last = sbi->s_groups_count;
669 const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
670 unsigned three = 1;
671 unsigned five = 5;
672 unsigned seven = 7;
673 ext4_group_t group;
674 int rest = sb->s_blocksize - size;
675 handle_t *handle;
676 int err = 0, err2;
677
678 handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
679 if (IS_ERR(handle)) {
680 group = 1;
681 err = PTR_ERR(handle);
682 goto exit_err;
683 }
684
685 while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) {
686 struct buffer_head *bh;
687
688 /* Out of journal space, and can't get more - abort - so sad */
689 if (ext4_handle_valid(handle) &&
690 handle->h_buffer_credits == 0 &&
691 ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA) &&
692 (err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
693 break;
694
695 bh = sb_getblk(sb, group * bpg + blk_off);
696 if (!bh) {
697 err = -EIO;
698 break;
699 }
700 ext4_debug("update metadata backup %#04lx\n",
701 (unsigned long)bh->b_blocknr);
702 if ((err = ext4_journal_get_write_access(handle, bh)))
703 break;
704 lock_buffer(bh);
705 memcpy(bh->b_data, data, size);
706 if (rest)
707 memset(bh->b_data + size, 0, rest);
708 set_buffer_uptodate(bh);
709 unlock_buffer(bh);
710 err = ext4_handle_dirty_metadata(handle, NULL, bh);
711 if (unlikely(err))
712 ext4_std_error(sb, err);
713 brelse(bh);
714 }
715 if ((err2 = ext4_journal_stop(handle)) && !err)
716 err = err2;
717
718 /*
719 * Ugh! Need to have e2fsck write the backup copies. It is too
720 * late to revert the resize, we shouldn't fail just because of
721 * the backup copies (they are only needed in case of corruption).
722 *
723 * However, if we got here we have a journal problem too, so we
724 * can't really start a transaction to mark the superblock.
725 * Chicken out and just set the flag on the hope it will be written
726 * to disk, and if not - we will simply wait until next fsck.
727 */
728exit_err:
729 if (err) {
730 ext4_warning(sb, "can't update backup for group %u (err %d), "
731 "forcing fsck on next reboot", group, err);
732 sbi->s_mount_state &= ~EXT4_VALID_FS;
733 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
734 mark_buffer_dirty(sbi->s_sbh);
735 }
736}
737
738/* Add group descriptor data to an existing or new group descriptor block.
739 * Ensure we handle all possible error conditions _before_ we start modifying
740 * the filesystem, because we cannot abort the transaction and not have it
741 * write the data to disk.
742 *
743 * If we are on a GDT block boundary, we need to get the reserved GDT block.
744 * Otherwise, we may need to add backup GDT blocks for a sparse group.
745 *
746 * We only need to hold the superblock lock while we are actually adding
747 * in the new group's counts to the superblock. Prior to that we have
748 * not really "added" the group at all. We re-check that we are still
749 * adding in the last group in case things have changed since verifying.
750 */
751int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
752{
753 struct ext4_sb_info *sbi = EXT4_SB(sb);
754 struct ext4_super_block *es = sbi->s_es;
755 int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
756 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
757 struct buffer_head *primary = NULL;
758 struct ext4_group_desc *gdp;
759 struct inode *inode = NULL;
760 handle_t *handle;
761 int gdb_off, gdb_num;
762 int err, err2;
763
764 gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb);
765 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb);
766
767 if (gdb_off == 0 && !EXT4_HAS_RO_COMPAT_FEATURE(sb,
768 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
769 ext4_warning(sb, "Can't resize non-sparse filesystem further");
770 return -EPERM;
771 }
772
773 if (ext4_blocks_count(es) + input->blocks_count <
774 ext4_blocks_count(es)) {
775 ext4_warning(sb, "blocks_count overflow");
776 return -EINVAL;
777 }
778
779 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) <
780 le32_to_cpu(es->s_inodes_count)) {
781 ext4_warning(sb, "inodes_count overflow");
782 return -EINVAL;
783 }
784
785 if (reserved_gdb || gdb_off == 0) {
786 if (!EXT4_HAS_COMPAT_FEATURE(sb,
787 EXT4_FEATURE_COMPAT_RESIZE_INODE)
788 || !le16_to_cpu(es->s_reserved_gdt_blocks)) {
789 ext4_warning(sb,
790 "No reserved GDT blocks, can't resize");
791 return -EPERM;
792 }
793 inode = ext4_iget(sb, EXT4_RESIZE_INO);
794 if (IS_ERR(inode)) {
795 ext4_warning(sb, "Error opening resize inode");
796 return PTR_ERR(inode);
797 }
798 }
799
800
801 if ((err = verify_group_input(sb, input)))
802 goto exit_put;
803
804 if ((err = setup_new_group_blocks(sb, input)))
805 goto exit_put;
806
807 /*
808 * We will always be modifying at least the superblock and a GDT
809 * block. If we are adding a group past the last current GDT block,
810 * we will also modify the inode and the dindirect block. If we
811 * are adding a group with superblock/GDT backups we will also
812 * modify each of the reserved GDT dindirect blocks.
813 */
814 handle = ext4_journal_start_sb(sb,
815 ext4_bg_has_super(sb, input->group) ?
816 3 + reserved_gdb : 4);
817 if (IS_ERR(handle)) {
818 err = PTR_ERR(handle);
819 goto exit_put;
820 }
821
822 if ((err = ext4_journal_get_write_access(handle, sbi->s_sbh)))
823 goto exit_journal;
824
825 /*
826 * We will only either add reserved group blocks to a backup group
827 * or remove reserved blocks for the first group in a new group block.
828 * Doing both would be mean more complex code, and sane people don't
829 * use non-sparse filesystems anymore. This is already checked above.
830 */
831 if (gdb_off) {
832 primary = sbi->s_group_desc[gdb_num];
833 if ((err = ext4_journal_get_write_access(handle, primary)))
834 goto exit_journal;
835
836 if (reserved_gdb && ext4_bg_num_gdb(sb, input->group)) {
837 err = reserve_backup_gdb(handle, inode, input->group);
838 if (err)
839 goto exit_journal;
840 }
841 } else {
842 /*
843 * Note that we can access new group descriptor block safely
844 * only if add_new_gdb() succeeds.
845 */
846 err = add_new_gdb(handle, inode, input->group);
847 if (err)
848 goto exit_journal;
849 primary = sbi->s_group_desc[gdb_num];
850 }
851
852 /*
853 * OK, now we've set up the new group. Time to make it active.
854 *
855 * so we have to be safe wrt. concurrent accesses the group
856 * data. So we need to be careful to set all of the relevant
857 * group descriptor data etc. *before* we enable the group.
858 *
859 * The key field here is sbi->s_groups_count: as long as
860 * that retains its old value, nobody is going to access the new
861 * group.
862 *
863 * So first we update all the descriptor metadata for the new
864 * group; then we update the total disk blocks count; then we
865 * update the groups count to enable the group; then finally we
866 * update the free space counts so that the system can start
867 * using the new disk blocks.
868 */
869
870 /* Update group descriptor block for new group */
871 gdp = (struct ext4_group_desc *)((char *)primary->b_data +
872 gdb_off * EXT4_DESC_SIZE(sb));
873
874 memset(gdp, 0, EXT4_DESC_SIZE(sb));
875 ext4_block_bitmap_set(sb, gdp, input->block_bitmap); /* LV FIXME */
876 ext4_inode_bitmap_set(sb, gdp, input->inode_bitmap); /* LV FIXME */
877 ext4_inode_table_set(sb, gdp, input->inode_table); /* LV FIXME */
878 ext4_free_blks_set(sb, gdp, input->free_blocks_count);
879 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
880 gdp->bg_flags = cpu_to_le16(EXT4_BG_INODE_ZEROED);
881 gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp);
882
883 /*
884 * We can allocate memory for mb_alloc based on the new group
885 * descriptor
886 */
887 err = ext4_mb_add_groupinfo(sb, input->group, gdp);
888 if (err)
889 goto exit_journal;
890
891 /*
892 * Make the new blocks and inodes valid next. We do this before
893 * increasing the group count so that once the group is enabled,
894 * all of its blocks and inodes are already valid.
895 *
896 * We always allocate group-by-group, then block-by-block or
897 * inode-by-inode within a group, so enabling these
898 * blocks/inodes before the group is live won't actually let us
899 * allocate the new space yet.
900 */
901 ext4_blocks_count_set(es, ext4_blocks_count(es) +
902 input->blocks_count);
903 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb));
904
905 /*
906 * We need to protect s_groups_count against other CPUs seeing
907 * inconsistent state in the superblock.
908 *
909 * The precise rules we use are:
910 *
911 * * Writers must perform a smp_wmb() after updating all dependent
912 * data and before modifying the groups count
913 *
914 * * Readers must perform an smp_rmb() after reading the groups count
915 * and before reading any dependent data.
916 *
917 * NB. These rules can be relaxed when checking the group count
918 * while freeing data, as we can only allocate from a block
919 * group after serialising against the group count, and we can
920 * only then free after serialising in turn against that
921 * allocation.
922 */
923 smp_wmb();
924
925 /* Update the global fs size fields */
926 sbi->s_groups_count++;
927
928 err = ext4_handle_dirty_metadata(handle, NULL, primary);
929 if (unlikely(err)) {
930 ext4_std_error(sb, err);
931 goto exit_journal;
932 }
933
934 /* Update the reserved block counts only once the new group is
935 * active. */
936 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) +
937 input->reserved_blocks);
938
939 /* Update the free space counts */
940 percpu_counter_add(&sbi->s_freeblocks_counter,
941 input->free_blocks_count);
942 percpu_counter_add(&sbi->s_freeinodes_counter,
943 EXT4_INODES_PER_GROUP(sb));
944
945 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
946 sbi->s_log_groups_per_flex) {
947 ext4_group_t flex_group;
948 flex_group = ext4_flex_group(sbi, input->group);
949 atomic_add(input->free_blocks_count,
950 &sbi->s_flex_groups[flex_group].free_blocks);
951 atomic_add(EXT4_INODES_PER_GROUP(sb),
952 &sbi->s_flex_groups[flex_group].free_inodes);
953 }
954
955 ext4_handle_dirty_super(handle, sb);
956
957exit_journal:
958 if ((err2 = ext4_journal_stop(handle)) && !err)
959 err = err2;
960 if (!err && primary) {
961 update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
962 sizeof(struct ext4_super_block));
963 update_backups(sb, primary->b_blocknr, primary->b_data,
964 primary->b_size);
965 }
966exit_put:
967 iput(inode);
968 return err;
969} /* ext4_group_add */
970
971/*
972 * Extend the filesystem to the new number of blocks specified. This entry
973 * point is only used to extend the current filesystem to the end of the last
974 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>"
975 * for emergencies (because it has no dependencies on reserved blocks).
976 *
977 * If we _really_ wanted, we could use default values to call ext4_group_add()
978 * allow the "remount" trick to work for arbitrary resizing, assuming enough
979 * GDT blocks are reserved to grow to the desired size.
980 */
981int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
982 ext4_fsblk_t n_blocks_count)
983{
984 ext4_fsblk_t o_blocks_count;
985 ext4_grpblk_t last;
986 ext4_grpblk_t add;
987 struct buffer_head *bh;
988 handle_t *handle;
989 int err, err2;
990 ext4_group_t group;
991
992 o_blocks_count = ext4_blocks_count(es);
993
994 if (test_opt(sb, DEBUG))
995 printk(KERN_DEBUG "EXT4-fs: extending last group from %llu to %llu blocks\n",
996 o_blocks_count, n_blocks_count);
997
998 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
999 return 0;
1000
1001 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1002 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
1003 " too large to resize to %llu blocks safely\n",
1004 sb->s_id, n_blocks_count);
1005 if (sizeof(sector_t) < 8)
1006 ext4_warning(sb, "CONFIG_LBDAF not enabled");
1007 return -EINVAL;
1008 }
1009
1010 if (n_blocks_count < o_blocks_count) {
1011 ext4_warning(sb, "can't shrink FS - resize aborted");
1012 return -EINVAL;
1013 }
1014
1015 /* Handle the remaining blocks in the last group only. */
1016 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1017
1018 if (last == 0) {
1019 ext4_warning(sb, "need to use ext2online to resize further");
1020 return -EPERM;
1021 }
1022
1023 add = EXT4_BLOCKS_PER_GROUP(sb) - last;
1024
1025 if (o_blocks_count + add < o_blocks_count) {
1026 ext4_warning(sb, "blocks_count overflow");
1027 return -EINVAL;
1028 }
1029
1030 if (o_blocks_count + add > n_blocks_count)
1031 add = n_blocks_count - o_blocks_count;
1032
1033 if (o_blocks_count + add < n_blocks_count)
1034 ext4_warning(sb, "will only finish group (%llu blocks, %u new)",
1035 o_blocks_count + add, add);
1036
1037 /* See if the device is actually as big as what was requested */
1038 bh = sb_bread(sb, o_blocks_count + add - 1);
1039 if (!bh) {
1040 ext4_warning(sb, "can't read last block, resize aborted");
1041 return -ENOSPC;
1042 }
1043 brelse(bh);
1044
1045 /* We will update the superblock, one block bitmap, and
1046 * one group descriptor via ext4_free_blocks().
1047 */
1048 handle = ext4_journal_start_sb(sb, 3);
1049 if (IS_ERR(handle)) {
1050 err = PTR_ERR(handle);
1051 ext4_warning(sb, "error %d on journal start", err);
1052 goto exit_put;
1053 }
1054
1055 if ((err = ext4_journal_get_write_access(handle,
1056 EXT4_SB(sb)->s_sbh))) {
1057 ext4_warning(sb, "error %d on journal write access", err);
1058 ext4_journal_stop(handle);
1059 goto exit_put;
1060 }
1061 ext4_blocks_count_set(es, o_blocks_count + add);
1062 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
1063 o_blocks_count + add);
1064 /* We add the blocks to the bitmap and set the group need init bit */
1065 err = ext4_group_add_blocks(handle, sb, o_blocks_count, add);
1066 ext4_handle_dirty_super(handle, sb);
1067 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
1068 o_blocks_count + add);
1069 err2 = ext4_journal_stop(handle);
1070 if (!err && err2)
1071 err = err2;
1072
1073 if (err)
1074 goto exit_put;
1075
1076 if (test_opt(sb, DEBUG))
1077 printk(KERN_DEBUG "EXT4-fs: extended group to %llu blocks\n",
1078 ext4_blocks_count(es));
1079 update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, (char *)es,
1080 sizeof(struct ext4_super_block));
1081exit_put:
1082 return err;
1083} /* ext4_group_extend */
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/ext4/resize.c
4 *
5 * Support for resizing an ext4 filesystem while it is mounted.
6 *
7 * Copyright (C) 2001, 2002 Andreas Dilger <adilger@clusterfs.com>
8 *
9 * This could probably be made into a module, because it is not often in use.
10 */
11
12
13#define EXT4FS_DEBUG
14
15#include <linux/errno.h>
16#include <linux/slab.h>
17#include <linux/jiffies.h>
18
19#include "ext4_jbd2.h"
20
21struct ext4_rcu_ptr {
22 struct rcu_head rcu;
23 void *ptr;
24};
25
26static void ext4_rcu_ptr_callback(struct rcu_head *head)
27{
28 struct ext4_rcu_ptr *ptr;
29
30 ptr = container_of(head, struct ext4_rcu_ptr, rcu);
31 kvfree(ptr->ptr);
32 kfree(ptr);
33}
34
35void ext4_kvfree_array_rcu(void *to_free)
36{
37 struct ext4_rcu_ptr *ptr = kzalloc(sizeof(*ptr), GFP_KERNEL);
38
39 if (ptr) {
40 ptr->ptr = to_free;
41 call_rcu(&ptr->rcu, ext4_rcu_ptr_callback);
42 return;
43 }
44 synchronize_rcu();
45 kvfree(to_free);
46}
47
48int ext4_resize_begin(struct super_block *sb)
49{
50 struct ext4_sb_info *sbi = EXT4_SB(sb);
51 int ret = 0;
52
53 if (!capable(CAP_SYS_RESOURCE))
54 return -EPERM;
55
56 /*
57 * If the reserved GDT blocks is non-zero, the resize_inode feature
58 * should always be set.
59 */
60 if (EXT4_SB(sb)->s_es->s_reserved_gdt_blocks &&
61 !ext4_has_feature_resize_inode(sb)) {
62 ext4_error(sb, "resize_inode disabled but reserved GDT blocks non-zero");
63 return -EFSCORRUPTED;
64 }
65
66 /*
67 * If we are not using the primary superblock/GDT copy don't resize,
68 * because the user tools have no way of handling this. Probably a
69 * bad time to do it anyways.
70 */
71 if (EXT4_B2C(sbi, sbi->s_sbh->b_blocknr) !=
72 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
73 ext4_warning(sb, "won't resize using backup superblock at %llu",
74 (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
75 return -EPERM;
76 }
77
78 /*
79 * We are not allowed to do online-resizing on a filesystem mounted
80 * with error, because it can destroy the filesystem easily.
81 */
82 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
83 ext4_warning(sb, "There are errors in the filesystem, "
84 "so online resizing is not allowed");
85 return -EPERM;
86 }
87
88 if (ext4_has_feature_sparse_super2(sb)) {
89 ext4_msg(sb, KERN_ERR, "Online resizing not supported with sparse_super2");
90 return -EOPNOTSUPP;
91 }
92
93 if (test_and_set_bit_lock(EXT4_FLAGS_RESIZING,
94 &EXT4_SB(sb)->s_ext4_flags))
95 ret = -EBUSY;
96
97 return ret;
98}
99
100int ext4_resize_end(struct super_block *sb, bool update_backups)
101{
102 clear_bit_unlock(EXT4_FLAGS_RESIZING, &EXT4_SB(sb)->s_ext4_flags);
103 smp_mb__after_atomic();
104 if (update_backups)
105 return ext4_update_overhead(sb, true);
106 return 0;
107}
108
109static ext4_group_t ext4_meta_bg_first_group(struct super_block *sb,
110 ext4_group_t group) {
111 return (group >> EXT4_DESC_PER_BLOCK_BITS(sb)) <<
112 EXT4_DESC_PER_BLOCK_BITS(sb);
113}
114
115static ext4_fsblk_t ext4_meta_bg_first_block_no(struct super_block *sb,
116 ext4_group_t group) {
117 group = ext4_meta_bg_first_group(sb, group);
118 return ext4_group_first_block_no(sb, group);
119}
120
121static ext4_grpblk_t ext4_group_overhead_blocks(struct super_block *sb,
122 ext4_group_t group) {
123 ext4_grpblk_t overhead;
124 overhead = ext4_bg_num_gdb(sb, group);
125 if (ext4_bg_has_super(sb, group))
126 overhead += 1 +
127 le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
128 return overhead;
129}
130
131#define outside(b, first, last) ((b) < (first) || (b) >= (last))
132#define inside(b, first, last) ((b) >= (first) && (b) < (last))
133
134static int verify_group_input(struct super_block *sb,
135 struct ext4_new_group_data *input)
136{
137 struct ext4_sb_info *sbi = EXT4_SB(sb);
138 struct ext4_super_block *es = sbi->s_es;
139 ext4_fsblk_t start = ext4_blocks_count(es);
140 ext4_fsblk_t end = start + input->blocks_count;
141 ext4_group_t group = input->group;
142 ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
143 unsigned overhead;
144 ext4_fsblk_t metaend;
145 struct buffer_head *bh = NULL;
146 ext4_grpblk_t free_blocks_count, offset;
147 int err = -EINVAL;
148
149 if (group != sbi->s_groups_count) {
150 ext4_warning(sb, "Cannot add at group %u (only %u groups)",
151 input->group, sbi->s_groups_count);
152 return -EINVAL;
153 }
154
155 overhead = ext4_group_overhead_blocks(sb, group);
156 metaend = start + overhead;
157 input->free_clusters_count = free_blocks_count =
158 input->blocks_count - 2 - overhead - sbi->s_itb_per_group;
159
160 if (test_opt(sb, DEBUG))
161 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks "
162 "(%d free, %u reserved)\n",
163 ext4_bg_has_super(sb, input->group) ? "normal" :
164 "no-super", input->group, input->blocks_count,
165 free_blocks_count, input->reserved_blocks);
166
167 ext4_get_group_no_and_offset(sb, start, NULL, &offset);
168 if (offset != 0)
169 ext4_warning(sb, "Last group not full");
170 else if (input->reserved_blocks > input->blocks_count / 5)
171 ext4_warning(sb, "Reserved blocks too high (%u)",
172 input->reserved_blocks);
173 else if (free_blocks_count < 0)
174 ext4_warning(sb, "Bad blocks count %u",
175 input->blocks_count);
176 else if (IS_ERR(bh = ext4_sb_bread(sb, end - 1, 0))) {
177 err = PTR_ERR(bh);
178 bh = NULL;
179 ext4_warning(sb, "Cannot read last block (%llu)",
180 end - 1);
181 } else if (outside(input->block_bitmap, start, end))
182 ext4_warning(sb, "Block bitmap not in group (block %llu)",
183 (unsigned long long)input->block_bitmap);
184 else if (outside(input->inode_bitmap, start, end))
185 ext4_warning(sb, "Inode bitmap not in group (block %llu)",
186 (unsigned long long)input->inode_bitmap);
187 else if (outside(input->inode_table, start, end) ||
188 outside(itend - 1, start, end))
189 ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)",
190 (unsigned long long)input->inode_table, itend - 1);
191 else if (input->inode_bitmap == input->block_bitmap)
192 ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)",
193 (unsigned long long)input->block_bitmap);
194 else if (inside(input->block_bitmap, input->inode_table, itend))
195 ext4_warning(sb, "Block bitmap (%llu) in inode table "
196 "(%llu-%llu)",
197 (unsigned long long)input->block_bitmap,
198 (unsigned long long)input->inode_table, itend - 1);
199 else if (inside(input->inode_bitmap, input->inode_table, itend))
200 ext4_warning(sb, "Inode bitmap (%llu) in inode table "
201 "(%llu-%llu)",
202 (unsigned long long)input->inode_bitmap,
203 (unsigned long long)input->inode_table, itend - 1);
204 else if (inside(input->block_bitmap, start, metaend))
205 ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)",
206 (unsigned long long)input->block_bitmap,
207 start, metaend - 1);
208 else if (inside(input->inode_bitmap, start, metaend))
209 ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)",
210 (unsigned long long)input->inode_bitmap,
211 start, metaend - 1);
212 else if (inside(input->inode_table, start, metaend) ||
213 inside(itend - 1, start, metaend))
214 ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table "
215 "(%llu-%llu)",
216 (unsigned long long)input->inode_table,
217 itend - 1, start, metaend - 1);
218 else
219 err = 0;
220 brelse(bh);
221
222 return err;
223}
224
225/*
226 * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex
227 * group each time.
228 */
229struct ext4_new_flex_group_data {
230 struct ext4_new_group_data *groups; /* new_group_data for groups
231 in the flex group */
232 __u16 *bg_flags; /* block group flags of groups
233 in @groups */
234 ext4_group_t count; /* number of groups in @groups
235 */
236};
237
238/*
239 * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of
240 * @flexbg_size.
241 *
242 * Returns NULL on failure otherwise address of the allocated structure.
243 */
244static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size)
245{
246 struct ext4_new_flex_group_data *flex_gd;
247
248 flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS);
249 if (flex_gd == NULL)
250 goto out3;
251
252 if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_group_data))
253 goto out2;
254 flex_gd->count = flexbg_size;
255
256 flex_gd->groups = kmalloc_array(flexbg_size,
257 sizeof(struct ext4_new_group_data),
258 GFP_NOFS);
259 if (flex_gd->groups == NULL)
260 goto out2;
261
262 flex_gd->bg_flags = kmalloc_array(flexbg_size, sizeof(__u16),
263 GFP_NOFS);
264 if (flex_gd->bg_flags == NULL)
265 goto out1;
266
267 return flex_gd;
268
269out1:
270 kfree(flex_gd->groups);
271out2:
272 kfree(flex_gd);
273out3:
274 return NULL;
275}
276
277static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd)
278{
279 kfree(flex_gd->bg_flags);
280 kfree(flex_gd->groups);
281 kfree(flex_gd);
282}
283
284/*
285 * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps
286 * and inode tables for a flex group.
287 *
288 * This function is used by 64bit-resize. Note that this function allocates
289 * group tables from the 1st group of groups contained by @flexgd, which may
290 * be a partial of a flex group.
291 *
292 * @sb: super block of fs to which the groups belongs
293 *
294 * Returns 0 on a successful allocation of the metadata blocks in the
295 * block group.
296 */
297static int ext4_alloc_group_tables(struct super_block *sb,
298 struct ext4_new_flex_group_data *flex_gd,
299 int flexbg_size)
300{
301 struct ext4_new_group_data *group_data = flex_gd->groups;
302 ext4_fsblk_t start_blk;
303 ext4_fsblk_t last_blk;
304 ext4_group_t src_group;
305 ext4_group_t bb_index = 0;
306 ext4_group_t ib_index = 0;
307 ext4_group_t it_index = 0;
308 ext4_group_t group;
309 ext4_group_t last_group;
310 unsigned overhead;
311 __u16 uninit_mask = (flexbg_size > 1) ? ~EXT4_BG_BLOCK_UNINIT : ~0;
312 int i;
313
314 BUG_ON(flex_gd->count == 0 || group_data == NULL);
315
316 src_group = group_data[0].group;
317 last_group = src_group + flex_gd->count - 1;
318
319 BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) !=
320 (last_group & ~(flexbg_size - 1))));
321next_group:
322 group = group_data[0].group;
323 if (src_group >= group_data[0].group + flex_gd->count)
324 return -ENOSPC;
325 start_blk = ext4_group_first_block_no(sb, src_group);
326 last_blk = start_blk + group_data[src_group - group].blocks_count;
327
328 overhead = ext4_group_overhead_blocks(sb, src_group);
329
330 start_blk += overhead;
331
332 /* We collect contiguous blocks as much as possible. */
333 src_group++;
334 for (; src_group <= last_group; src_group++) {
335 overhead = ext4_group_overhead_blocks(sb, src_group);
336 if (overhead == 0)
337 last_blk += group_data[src_group - group].blocks_count;
338 else
339 break;
340 }
341
342 /* Allocate block bitmaps */
343 for (; bb_index < flex_gd->count; bb_index++) {
344 if (start_blk >= last_blk)
345 goto next_group;
346 group_data[bb_index].block_bitmap = start_blk++;
347 group = ext4_get_group_number(sb, start_blk - 1);
348 group -= group_data[0].group;
349 group_data[group].mdata_blocks++;
350 flex_gd->bg_flags[group] &= uninit_mask;
351 }
352
353 /* Allocate inode bitmaps */
354 for (; ib_index < flex_gd->count; ib_index++) {
355 if (start_blk >= last_blk)
356 goto next_group;
357 group_data[ib_index].inode_bitmap = start_blk++;
358 group = ext4_get_group_number(sb, start_blk - 1);
359 group -= group_data[0].group;
360 group_data[group].mdata_blocks++;
361 flex_gd->bg_flags[group] &= uninit_mask;
362 }
363
364 /* Allocate inode tables */
365 for (; it_index < flex_gd->count; it_index++) {
366 unsigned int itb = EXT4_SB(sb)->s_itb_per_group;
367 ext4_fsblk_t next_group_start;
368
369 if (start_blk + itb > last_blk)
370 goto next_group;
371 group_data[it_index].inode_table = start_blk;
372 group = ext4_get_group_number(sb, start_blk);
373 next_group_start = ext4_group_first_block_no(sb, group + 1);
374 group -= group_data[0].group;
375
376 if (start_blk + itb > next_group_start) {
377 flex_gd->bg_flags[group + 1] &= uninit_mask;
378 overhead = start_blk + itb - next_group_start;
379 group_data[group + 1].mdata_blocks += overhead;
380 itb -= overhead;
381 }
382
383 group_data[group].mdata_blocks += itb;
384 flex_gd->bg_flags[group] &= uninit_mask;
385 start_blk += EXT4_SB(sb)->s_itb_per_group;
386 }
387
388 /* Update free clusters count to exclude metadata blocks */
389 for (i = 0; i < flex_gd->count; i++) {
390 group_data[i].free_clusters_count -=
391 EXT4_NUM_B2C(EXT4_SB(sb),
392 group_data[i].mdata_blocks);
393 }
394
395 if (test_opt(sb, DEBUG)) {
396 int i;
397 group = group_data[0].group;
398
399 printk(KERN_DEBUG "EXT4-fs: adding a flex group with "
400 "%d groups, flexbg size is %d:\n", flex_gd->count,
401 flexbg_size);
402
403 for (i = 0; i < flex_gd->count; i++) {
404 ext4_debug(
405 "adding %s group %u: %u blocks (%d free, %d mdata blocks)\n",
406 ext4_bg_has_super(sb, group + i) ? "normal" :
407 "no-super", group + i,
408 group_data[i].blocks_count,
409 group_data[i].free_clusters_count,
410 group_data[i].mdata_blocks);
411 }
412 }
413 return 0;
414}
415
416static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
417 ext4_fsblk_t blk)
418{
419 struct buffer_head *bh;
420 int err;
421
422 bh = sb_getblk(sb, blk);
423 if (unlikely(!bh))
424 return ERR_PTR(-ENOMEM);
425 BUFFER_TRACE(bh, "get_write_access");
426 err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
427 if (err) {
428 brelse(bh);
429 bh = ERR_PTR(err);
430 } else {
431 memset(bh->b_data, 0, sb->s_blocksize);
432 set_buffer_uptodate(bh);
433 }
434
435 return bh;
436}
437
438static int ext4_resize_ensure_credits_batch(handle_t *handle, int credits)
439{
440 return ext4_journal_ensure_credits_fn(handle, credits,
441 EXT4_MAX_TRANS_DATA, 0, 0);
442}
443
444/*
445 * set_flexbg_block_bitmap() mark clusters [@first_cluster, @last_cluster] used.
446 *
447 * Helper function for ext4_setup_new_group_blocks() which set .
448 *
449 * @sb: super block
450 * @handle: journal handle
451 * @flex_gd: flex group data
452 */
453static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle,
454 struct ext4_new_flex_group_data *flex_gd,
455 ext4_fsblk_t first_cluster, ext4_fsblk_t last_cluster)
456{
457 struct ext4_sb_info *sbi = EXT4_SB(sb);
458 ext4_group_t count = last_cluster - first_cluster + 1;
459 ext4_group_t count2;
460
461 ext4_debug("mark clusters [%llu-%llu] used\n", first_cluster,
462 last_cluster);
463 for (count2 = count; count > 0;
464 count -= count2, first_cluster += count2) {
465 ext4_fsblk_t start;
466 struct buffer_head *bh;
467 ext4_group_t group;
468 int err;
469
470 group = ext4_get_group_number(sb, EXT4_C2B(sbi, first_cluster));
471 start = EXT4_B2C(sbi, ext4_group_first_block_no(sb, group));
472 group -= flex_gd->groups[0].group;
473
474 count2 = EXT4_CLUSTERS_PER_GROUP(sb) - (first_cluster - start);
475 if (count2 > count)
476 count2 = count;
477
478 if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) {
479 BUG_ON(flex_gd->count > 1);
480 continue;
481 }
482
483 err = ext4_resize_ensure_credits_batch(handle, 1);
484 if (err < 0)
485 return err;
486
487 bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap);
488 if (unlikely(!bh))
489 return -ENOMEM;
490
491 BUFFER_TRACE(bh, "get_write_access");
492 err = ext4_journal_get_write_access(handle, sb, bh,
493 EXT4_JTR_NONE);
494 if (err) {
495 brelse(bh);
496 return err;
497 }
498 ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n",
499 first_cluster, first_cluster - start, count2);
500 mb_set_bits(bh->b_data, first_cluster - start, count2);
501
502 err = ext4_handle_dirty_metadata(handle, NULL, bh);
503 brelse(bh);
504 if (unlikely(err))
505 return err;
506 }
507
508 return 0;
509}
510
511/*
512 * Set up the block and inode bitmaps, and the inode table for the new groups.
513 * This doesn't need to be part of the main transaction, since we are only
514 * changing blocks outside the actual filesystem. We still do journaling to
515 * ensure the recovery is correct in case of a failure just after resize.
516 * If any part of this fails, we simply abort the resize.
517 *
518 * setup_new_flex_group_blocks handles a flex group as follow:
519 * 1. copy super block and GDT, and initialize group tables if necessary.
520 * In this step, we only set bits in blocks bitmaps for blocks taken by
521 * super block and GDT.
522 * 2. allocate group tables in block bitmaps, that is, set bits in block
523 * bitmap for blocks taken by group tables.
524 */
525static int setup_new_flex_group_blocks(struct super_block *sb,
526 struct ext4_new_flex_group_data *flex_gd)
527{
528 int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group};
529 ext4_fsblk_t start;
530 ext4_fsblk_t block;
531 struct ext4_sb_info *sbi = EXT4_SB(sb);
532 struct ext4_super_block *es = sbi->s_es;
533 struct ext4_new_group_data *group_data = flex_gd->groups;
534 __u16 *bg_flags = flex_gd->bg_flags;
535 handle_t *handle;
536 ext4_group_t group, count;
537 struct buffer_head *bh = NULL;
538 int reserved_gdb, i, j, err = 0, err2;
539 int meta_bg;
540
541 BUG_ON(!flex_gd->count || !group_data ||
542 group_data[0].group != sbi->s_groups_count);
543
544 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
545 meta_bg = ext4_has_feature_meta_bg(sb);
546
547 /* This transaction may be extended/restarted along the way */
548 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA);
549 if (IS_ERR(handle))
550 return PTR_ERR(handle);
551
552 group = group_data[0].group;
553 for (i = 0; i < flex_gd->count; i++, group++) {
554 unsigned long gdblocks;
555 ext4_grpblk_t overhead;
556
557 gdblocks = ext4_bg_num_gdb(sb, group);
558 start = ext4_group_first_block_no(sb, group);
559
560 if (meta_bg == 0 && !ext4_bg_has_super(sb, group))
561 goto handle_itb;
562
563 if (meta_bg == 1) {
564 ext4_group_t first_group;
565 first_group = ext4_meta_bg_first_group(sb, group);
566 if (first_group != group + 1 &&
567 first_group != group + EXT4_DESC_PER_BLOCK(sb) - 1)
568 goto handle_itb;
569 }
570
571 block = start + ext4_bg_has_super(sb, group);
572 /* Copy all of the GDT blocks into the backup in this group */
573 for (j = 0; j < gdblocks; j++, block++) {
574 struct buffer_head *gdb;
575
576 ext4_debug("update backup group %#04llx\n", block);
577 err = ext4_resize_ensure_credits_batch(handle, 1);
578 if (err < 0)
579 goto out;
580
581 gdb = sb_getblk(sb, block);
582 if (unlikely(!gdb)) {
583 err = -ENOMEM;
584 goto out;
585 }
586
587 BUFFER_TRACE(gdb, "get_write_access");
588 err = ext4_journal_get_write_access(handle, sb, gdb,
589 EXT4_JTR_NONE);
590 if (err) {
591 brelse(gdb);
592 goto out;
593 }
594 memcpy(gdb->b_data, sbi_array_rcu_deref(sbi,
595 s_group_desc, j)->b_data, gdb->b_size);
596 set_buffer_uptodate(gdb);
597
598 err = ext4_handle_dirty_metadata(handle, NULL, gdb);
599 if (unlikely(err)) {
600 brelse(gdb);
601 goto out;
602 }
603 brelse(gdb);
604 }
605
606 /* Zero out all of the reserved backup group descriptor
607 * table blocks
608 */
609 if (ext4_bg_has_super(sb, group)) {
610 err = sb_issue_zeroout(sb, gdblocks + start + 1,
611 reserved_gdb, GFP_NOFS);
612 if (err)
613 goto out;
614 }
615
616handle_itb:
617 /* Initialize group tables of the grop @group */
618 if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED))
619 goto handle_bb;
620
621 /* Zero out all of the inode table blocks */
622 block = group_data[i].inode_table;
623 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n",
624 block, sbi->s_itb_per_group);
625 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group,
626 GFP_NOFS);
627 if (err)
628 goto out;
629
630handle_bb:
631 if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT)
632 goto handle_ib;
633
634 /* Initialize block bitmap of the @group */
635 block = group_data[i].block_bitmap;
636 err = ext4_resize_ensure_credits_batch(handle, 1);
637 if (err < 0)
638 goto out;
639
640 bh = bclean(handle, sb, block);
641 if (IS_ERR(bh)) {
642 err = PTR_ERR(bh);
643 goto out;
644 }
645 overhead = ext4_group_overhead_blocks(sb, group);
646 if (overhead != 0) {
647 ext4_debug("mark backup superblock %#04llx (+0)\n",
648 start);
649 mb_set_bits(bh->b_data, 0,
650 EXT4_NUM_B2C(sbi, overhead));
651 }
652 ext4_mark_bitmap_end(EXT4_B2C(sbi, group_data[i].blocks_count),
653 sb->s_blocksize * 8, bh->b_data);
654 err = ext4_handle_dirty_metadata(handle, NULL, bh);
655 brelse(bh);
656 if (err)
657 goto out;
658
659handle_ib:
660 if (bg_flags[i] & EXT4_BG_INODE_UNINIT)
661 continue;
662
663 /* Initialize inode bitmap of the @group */
664 block = group_data[i].inode_bitmap;
665 err = ext4_resize_ensure_credits_batch(handle, 1);
666 if (err < 0)
667 goto out;
668 /* Mark unused entries in inode bitmap used */
669 bh = bclean(handle, sb, block);
670 if (IS_ERR(bh)) {
671 err = PTR_ERR(bh);
672 goto out;
673 }
674
675 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
676 sb->s_blocksize * 8, bh->b_data);
677 err = ext4_handle_dirty_metadata(handle, NULL, bh);
678 brelse(bh);
679 if (err)
680 goto out;
681 }
682
683 /* Mark group tables in block bitmap */
684 for (j = 0; j < GROUP_TABLE_COUNT; j++) {
685 count = group_table_count[j];
686 start = (&group_data[0].block_bitmap)[j];
687 block = start;
688 for (i = 1; i < flex_gd->count; i++) {
689 block += group_table_count[j];
690 if (block == (&group_data[i].block_bitmap)[j]) {
691 count += group_table_count[j];
692 continue;
693 }
694 err = set_flexbg_block_bitmap(sb, handle,
695 flex_gd,
696 EXT4_B2C(sbi, start),
697 EXT4_B2C(sbi,
698 start + count
699 - 1));
700 if (err)
701 goto out;
702 count = group_table_count[j];
703 start = (&group_data[i].block_bitmap)[j];
704 block = start;
705 }
706
707 if (count) {
708 err = set_flexbg_block_bitmap(sb, handle,
709 flex_gd,
710 EXT4_B2C(sbi, start),
711 EXT4_B2C(sbi,
712 start + count
713 - 1));
714 if (err)
715 goto out;
716 }
717 }
718
719out:
720 err2 = ext4_journal_stop(handle);
721 if (err2 && !err)
722 err = err2;
723
724 return err;
725}
726
727/*
728 * Iterate through the groups which hold BACKUP superblock/GDT copies in an
729 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
730 * calling this for the first time. In a sparse filesystem it will be the
731 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
732 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
733 */
734unsigned int ext4_list_backups(struct super_block *sb, unsigned int *three,
735 unsigned int *five, unsigned int *seven)
736{
737 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
738 unsigned int *min = three;
739 int mult = 3;
740 unsigned int ret;
741
742 if (ext4_has_feature_sparse_super2(sb)) {
743 do {
744 if (*min > 2)
745 return UINT_MAX;
746 ret = le32_to_cpu(es->s_backup_bgs[*min - 1]);
747 *min += 1;
748 } while (!ret);
749 return ret;
750 }
751
752 if (!ext4_has_feature_sparse_super(sb)) {
753 ret = *min;
754 *min += 1;
755 return ret;
756 }
757
758 if (*five < *min) {
759 min = five;
760 mult = 5;
761 }
762 if (*seven < *min) {
763 min = seven;
764 mult = 7;
765 }
766
767 ret = *min;
768 *min *= mult;
769
770 return ret;
771}
772
773/*
774 * Check that all of the backup GDT blocks are held in the primary GDT block.
775 * It is assumed that they are stored in group order. Returns the number of
776 * groups in current filesystem that have BACKUPS, or -ve error code.
777 */
778static int verify_reserved_gdb(struct super_block *sb,
779 ext4_group_t end,
780 struct buffer_head *primary)
781{
782 const ext4_fsblk_t blk = primary->b_blocknr;
783 unsigned three = 1;
784 unsigned five = 5;
785 unsigned seven = 7;
786 unsigned grp;
787 __le32 *p = (__le32 *)primary->b_data;
788 int gdbackups = 0;
789
790 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) {
791 if (le32_to_cpu(*p++) !=
792 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){
793 ext4_warning(sb, "reserved GDT %llu"
794 " missing grp %d (%llu)",
795 blk, grp,
796 grp *
797 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
798 blk);
799 return -EINVAL;
800 }
801 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb))
802 return -EFBIG;
803 }
804
805 return gdbackups;
806}
807
808/*
809 * Called when we need to bring a reserved group descriptor table block into
810 * use from the resize inode. The primary copy of the new GDT block currently
811 * is an indirect block (under the double indirect block in the resize inode).
812 * The new backup GDT blocks will be stored as leaf blocks in this indirect
813 * block, in group order. Even though we know all the block numbers we need,
814 * we check to ensure that the resize inode has actually reserved these blocks.
815 *
816 * Don't need to update the block bitmaps because the blocks are still in use.
817 *
818 * We get all of the error cases out of the way, so that we are sure to not
819 * fail once we start modifying the data on disk, because JBD has no rollback.
820 */
821static int add_new_gdb(handle_t *handle, struct inode *inode,
822 ext4_group_t group)
823{
824 struct super_block *sb = inode->i_sb;
825 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
826 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
827 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
828 struct buffer_head **o_group_desc, **n_group_desc = NULL;
829 struct buffer_head *dind = NULL;
830 struct buffer_head *gdb_bh = NULL;
831 int gdbackups;
832 struct ext4_iloc iloc = { .bh = NULL };
833 __le32 *data;
834 int err;
835
836 if (test_opt(sb, DEBUG))
837 printk(KERN_DEBUG
838 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
839 gdb_num);
840
841 gdb_bh = ext4_sb_bread(sb, gdblock, 0);
842 if (IS_ERR(gdb_bh))
843 return PTR_ERR(gdb_bh);
844
845 gdbackups = verify_reserved_gdb(sb, group, gdb_bh);
846 if (gdbackups < 0) {
847 err = gdbackups;
848 goto errout;
849 }
850
851 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
852 dind = ext4_sb_bread(sb, le32_to_cpu(*data), 0);
853 if (IS_ERR(dind)) {
854 err = PTR_ERR(dind);
855 dind = NULL;
856 goto errout;
857 }
858
859 data = (__le32 *)dind->b_data;
860 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) {
861 ext4_warning(sb, "new group %u GDT block %llu not reserved",
862 group, gdblock);
863 err = -EINVAL;
864 goto errout;
865 }
866
867 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
868 err = ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh,
869 EXT4_JTR_NONE);
870 if (unlikely(err))
871 goto errout;
872
873 BUFFER_TRACE(gdb_bh, "get_write_access");
874 err = ext4_journal_get_write_access(handle, sb, gdb_bh, EXT4_JTR_NONE);
875 if (unlikely(err))
876 goto errout;
877
878 BUFFER_TRACE(dind, "get_write_access");
879 err = ext4_journal_get_write_access(handle, sb, dind, EXT4_JTR_NONE);
880 if (unlikely(err)) {
881 ext4_std_error(sb, err);
882 goto errout;
883 }
884
885 /* ext4_reserve_inode_write() gets a reference on the iloc */
886 err = ext4_reserve_inode_write(handle, inode, &iloc);
887 if (unlikely(err))
888 goto errout;
889
890 n_group_desc = kvmalloc((gdb_num + 1) * sizeof(struct buffer_head *),
891 GFP_KERNEL);
892 if (!n_group_desc) {
893 err = -ENOMEM;
894 ext4_warning(sb, "not enough memory for %lu groups",
895 gdb_num + 1);
896 goto errout;
897 }
898
899 /*
900 * Finally, we have all of the possible failures behind us...
901 *
902 * Remove new GDT block from inode double-indirect block and clear out
903 * the new GDT block for use (which also "frees" the backup GDT blocks
904 * from the reserved inode). We don't need to change the bitmaps for
905 * these blocks, because they are marked as in-use from being in the
906 * reserved inode, and will become GDT blocks (primary and backup).
907 */
908 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0;
909 err = ext4_handle_dirty_metadata(handle, NULL, dind);
910 if (unlikely(err)) {
911 ext4_std_error(sb, err);
912 goto errout;
913 }
914 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >>
915 (9 - EXT4_SB(sb)->s_cluster_bits);
916 ext4_mark_iloc_dirty(handle, inode, &iloc);
917 memset(gdb_bh->b_data, 0, sb->s_blocksize);
918 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
919 if (unlikely(err)) {
920 ext4_std_error(sb, err);
921 iloc.bh = NULL;
922 goto errout;
923 }
924 brelse(dind);
925
926 rcu_read_lock();
927 o_group_desc = rcu_dereference(EXT4_SB(sb)->s_group_desc);
928 memcpy(n_group_desc, o_group_desc,
929 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
930 rcu_read_unlock();
931 n_group_desc[gdb_num] = gdb_bh;
932 rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc);
933 EXT4_SB(sb)->s_gdb_count++;
934 ext4_kvfree_array_rcu(o_group_desc);
935
936 lock_buffer(EXT4_SB(sb)->s_sbh);
937 le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
938 ext4_superblock_csum_set(sb);
939 unlock_buffer(EXT4_SB(sb)->s_sbh);
940 err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
941 if (err)
942 ext4_std_error(sb, err);
943 return err;
944errout:
945 kvfree(n_group_desc);
946 brelse(iloc.bh);
947 brelse(dind);
948 brelse(gdb_bh);
949
950 ext4_debug("leaving with error %d\n", err);
951 return err;
952}
953
954/*
955 * add_new_gdb_meta_bg is the sister of add_new_gdb.
956 */
957static int add_new_gdb_meta_bg(struct super_block *sb,
958 handle_t *handle, ext4_group_t group) {
959 ext4_fsblk_t gdblock;
960 struct buffer_head *gdb_bh;
961 struct buffer_head **o_group_desc, **n_group_desc;
962 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
963 int err;
964
965 gdblock = ext4_meta_bg_first_block_no(sb, group) +
966 ext4_bg_has_super(sb, group);
967 gdb_bh = ext4_sb_bread(sb, gdblock, 0);
968 if (IS_ERR(gdb_bh))
969 return PTR_ERR(gdb_bh);
970 n_group_desc = kvmalloc((gdb_num + 1) * sizeof(struct buffer_head *),
971 GFP_KERNEL);
972 if (!n_group_desc) {
973 brelse(gdb_bh);
974 err = -ENOMEM;
975 ext4_warning(sb, "not enough memory for %lu groups",
976 gdb_num + 1);
977 return err;
978 }
979
980 rcu_read_lock();
981 o_group_desc = rcu_dereference(EXT4_SB(sb)->s_group_desc);
982 memcpy(n_group_desc, o_group_desc,
983 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
984 rcu_read_unlock();
985 n_group_desc[gdb_num] = gdb_bh;
986
987 BUFFER_TRACE(gdb_bh, "get_write_access");
988 err = ext4_journal_get_write_access(handle, sb, gdb_bh, EXT4_JTR_NONE);
989 if (err) {
990 kvfree(n_group_desc);
991 brelse(gdb_bh);
992 return err;
993 }
994
995 rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc);
996 EXT4_SB(sb)->s_gdb_count++;
997 ext4_kvfree_array_rcu(o_group_desc);
998 return err;
999}
1000
1001/*
1002 * Called when we are adding a new group which has a backup copy of each of
1003 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
1004 * We need to add these reserved backup GDT blocks to the resize inode, so
1005 * that they are kept for future resizing and not allocated to files.
1006 *
1007 * Each reserved backup GDT block will go into a different indirect block.
1008 * The indirect blocks are actually the primary reserved GDT blocks,
1009 * so we know in advance what their block numbers are. We only get the
1010 * double-indirect block to verify it is pointing to the primary reserved
1011 * GDT blocks so we don't overwrite a data block by accident. The reserved
1012 * backup GDT blocks are stored in their reserved primary GDT block.
1013 */
1014static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
1015 ext4_group_t group)
1016{
1017 struct super_block *sb = inode->i_sb;
1018 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
1019 int cluster_bits = EXT4_SB(sb)->s_cluster_bits;
1020 struct buffer_head **primary;
1021 struct buffer_head *dind;
1022 struct ext4_iloc iloc;
1023 ext4_fsblk_t blk;
1024 __le32 *data, *end;
1025 int gdbackups = 0;
1026 int res, i;
1027 int err;
1028
1029 primary = kmalloc_array(reserved_gdb, sizeof(*primary), GFP_NOFS);
1030 if (!primary)
1031 return -ENOMEM;
1032
1033 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
1034 dind = ext4_sb_bread(sb, le32_to_cpu(*data), 0);
1035 if (IS_ERR(dind)) {
1036 err = PTR_ERR(dind);
1037 dind = NULL;
1038 goto exit_free;
1039 }
1040
1041 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count;
1042 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count %
1043 EXT4_ADDR_PER_BLOCK(sb));
1044 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb);
1045
1046 /* Get each reserved primary GDT block and verify it holds backups */
1047 for (res = 0; res < reserved_gdb; res++, blk++) {
1048 if (le32_to_cpu(*data) != blk) {
1049 ext4_warning(sb, "reserved block %llu"
1050 " not at offset %ld",
1051 blk,
1052 (long)(data - (__le32 *)dind->b_data));
1053 err = -EINVAL;
1054 goto exit_bh;
1055 }
1056 primary[res] = ext4_sb_bread(sb, blk, 0);
1057 if (IS_ERR(primary[res])) {
1058 err = PTR_ERR(primary[res]);
1059 primary[res] = NULL;
1060 goto exit_bh;
1061 }
1062 gdbackups = verify_reserved_gdb(sb, group, primary[res]);
1063 if (gdbackups < 0) {
1064 brelse(primary[res]);
1065 err = gdbackups;
1066 goto exit_bh;
1067 }
1068 if (++data >= end)
1069 data = (__le32 *)dind->b_data;
1070 }
1071
1072 for (i = 0; i < reserved_gdb; i++) {
1073 BUFFER_TRACE(primary[i], "get_write_access");
1074 if ((err = ext4_journal_get_write_access(handle, sb, primary[i],
1075 EXT4_JTR_NONE)))
1076 goto exit_bh;
1077 }
1078
1079 if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
1080 goto exit_bh;
1081
1082 /*
1083 * Finally we can add each of the reserved backup GDT blocks from
1084 * the new group to its reserved primary GDT block.
1085 */
1086 blk = group * EXT4_BLOCKS_PER_GROUP(sb);
1087 for (i = 0; i < reserved_gdb; i++) {
1088 int err2;
1089 data = (__le32 *)primary[i]->b_data;
1090 /* printk("reserving backup %lu[%u] = %lu\n",
1091 primary[i]->b_blocknr, gdbackups,
1092 blk + primary[i]->b_blocknr); */
1093 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
1094 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]);
1095 if (!err)
1096 err = err2;
1097 }
1098
1099 inode->i_blocks += reserved_gdb * sb->s_blocksize >> (9 - cluster_bits);
1100 ext4_mark_iloc_dirty(handle, inode, &iloc);
1101
1102exit_bh:
1103 while (--res >= 0)
1104 brelse(primary[res]);
1105 brelse(dind);
1106
1107exit_free:
1108 kfree(primary);
1109
1110 return err;
1111}
1112
1113static inline void ext4_set_block_group_nr(struct super_block *sb, char *data,
1114 ext4_group_t group)
1115{
1116 struct ext4_super_block *es = (struct ext4_super_block *) data;
1117
1118 es->s_block_group_nr = cpu_to_le16(group);
1119 if (ext4_has_metadata_csum(sb))
1120 es->s_checksum = ext4_superblock_csum(sb, es);
1121}
1122
1123/*
1124 * Update the backup copies of the ext4 metadata. These don't need to be part
1125 * of the main resize transaction, because e2fsck will re-write them if there
1126 * is a problem (basically only OOM will cause a problem). However, we
1127 * _should_ update the backups if possible, in case the primary gets trashed
1128 * for some reason and we need to run e2fsck from a backup superblock. The
1129 * important part is that the new block and inode counts are in the backup
1130 * superblocks, and the location of the new group metadata in the GDT backups.
1131 *
1132 * We do not need take the s_resize_lock for this, because these
1133 * blocks are not otherwise touched by the filesystem code when it is
1134 * mounted. We don't need to worry about last changing from
1135 * sbi->s_groups_count, because the worst that can happen is that we
1136 * do not copy the full number of backups at this time. The resize
1137 * which changed s_groups_count will backup again.
1138 */
1139static void update_backups(struct super_block *sb, sector_t blk_off, char *data,
1140 int size, int meta_bg)
1141{
1142 struct ext4_sb_info *sbi = EXT4_SB(sb);
1143 ext4_group_t last;
1144 const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
1145 unsigned three = 1;
1146 unsigned five = 5;
1147 unsigned seven = 7;
1148 ext4_group_t group = 0;
1149 int rest = sb->s_blocksize - size;
1150 handle_t *handle;
1151 int err = 0, err2;
1152
1153 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA);
1154 if (IS_ERR(handle)) {
1155 group = 1;
1156 err = PTR_ERR(handle);
1157 goto exit_err;
1158 }
1159
1160 if (meta_bg == 0) {
1161 group = ext4_list_backups(sb, &three, &five, &seven);
1162 last = sbi->s_groups_count;
1163 } else {
1164 group = ext4_get_group_number(sb, blk_off) + 1;
1165 last = (ext4_group_t)(group + EXT4_DESC_PER_BLOCK(sb) - 2);
1166 }
1167
1168 while (group < sbi->s_groups_count) {
1169 struct buffer_head *bh;
1170 ext4_fsblk_t backup_block;
1171 int has_super = ext4_bg_has_super(sb, group);
1172 ext4_fsblk_t first_block = ext4_group_first_block_no(sb, group);
1173
1174 /* Out of journal space, and can't get more - abort - so sad */
1175 err = ext4_resize_ensure_credits_batch(handle, 1);
1176 if (err < 0)
1177 break;
1178
1179 if (meta_bg == 0)
1180 backup_block = ((ext4_fsblk_t)group) * bpg + blk_off;
1181 else
1182 backup_block = first_block + has_super;
1183
1184 bh = sb_getblk(sb, backup_block);
1185 if (unlikely(!bh)) {
1186 err = -ENOMEM;
1187 break;
1188 }
1189 ext4_debug("update metadata backup %llu(+%llu)\n",
1190 backup_block, backup_block -
1191 ext4_group_first_block_no(sb, group));
1192 BUFFER_TRACE(bh, "get_write_access");
1193 if ((err = ext4_journal_get_write_access(handle, sb, bh,
1194 EXT4_JTR_NONE)))
1195 break;
1196 lock_buffer(bh);
1197 memcpy(bh->b_data, data, size);
1198 if (rest)
1199 memset(bh->b_data + size, 0, rest);
1200 if (has_super && (backup_block == first_block))
1201 ext4_set_block_group_nr(sb, bh->b_data, group);
1202 set_buffer_uptodate(bh);
1203 unlock_buffer(bh);
1204 err = ext4_handle_dirty_metadata(handle, NULL, bh);
1205 if (unlikely(err))
1206 ext4_std_error(sb, err);
1207 brelse(bh);
1208
1209 if (meta_bg == 0)
1210 group = ext4_list_backups(sb, &three, &five, &seven);
1211 else if (group == last)
1212 break;
1213 else
1214 group = last;
1215 }
1216 if ((err2 = ext4_journal_stop(handle)) && !err)
1217 err = err2;
1218
1219 /*
1220 * Ugh! Need to have e2fsck write the backup copies. It is too
1221 * late to revert the resize, we shouldn't fail just because of
1222 * the backup copies (they are only needed in case of corruption).
1223 *
1224 * However, if we got here we have a journal problem too, so we
1225 * can't really start a transaction to mark the superblock.
1226 * Chicken out and just set the flag on the hope it will be written
1227 * to disk, and if not - we will simply wait until next fsck.
1228 */
1229exit_err:
1230 if (err) {
1231 ext4_warning(sb, "can't update backup for group %u (err %d), "
1232 "forcing fsck on next reboot", group, err);
1233 sbi->s_mount_state &= ~EXT4_VALID_FS;
1234 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1235 mark_buffer_dirty(sbi->s_sbh);
1236 }
1237}
1238
1239/*
1240 * ext4_add_new_descs() adds @count group descriptor of groups
1241 * starting at @group
1242 *
1243 * @handle: journal handle
1244 * @sb: super block
1245 * @group: the group no. of the first group desc to be added
1246 * @resize_inode: the resize inode
1247 * @count: number of group descriptors to be added
1248 */
1249static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
1250 ext4_group_t group, struct inode *resize_inode,
1251 ext4_group_t count)
1252{
1253 struct ext4_sb_info *sbi = EXT4_SB(sb);
1254 struct ext4_super_block *es = sbi->s_es;
1255 struct buffer_head *gdb_bh;
1256 int i, gdb_off, gdb_num, err = 0;
1257 int meta_bg;
1258
1259 meta_bg = ext4_has_feature_meta_bg(sb);
1260 for (i = 0; i < count; i++, group++) {
1261 int reserved_gdb = ext4_bg_has_super(sb, group) ?
1262 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
1263
1264 gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
1265 gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1266
1267 /*
1268 * We will only either add reserved group blocks to a backup group
1269 * or remove reserved blocks for the first group in a new group block.
1270 * Doing both would be mean more complex code, and sane people don't
1271 * use non-sparse filesystems anymore. This is already checked above.
1272 */
1273 if (gdb_off) {
1274 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc,
1275 gdb_num);
1276 BUFFER_TRACE(gdb_bh, "get_write_access");
1277 err = ext4_journal_get_write_access(handle, sb, gdb_bh,
1278 EXT4_JTR_NONE);
1279
1280 if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group))
1281 err = reserve_backup_gdb(handle, resize_inode, group);
1282 } else if (meta_bg != 0) {
1283 err = add_new_gdb_meta_bg(sb, handle, group);
1284 } else {
1285 err = add_new_gdb(handle, resize_inode, group);
1286 }
1287 if (err)
1288 break;
1289 }
1290 return err;
1291}
1292
1293static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block)
1294{
1295 struct buffer_head *bh = sb_getblk(sb, block);
1296 if (unlikely(!bh))
1297 return NULL;
1298 if (!bh_uptodate_or_lock(bh)) {
1299 if (ext4_read_bh(bh, 0, NULL) < 0) {
1300 brelse(bh);
1301 return NULL;
1302 }
1303 }
1304
1305 return bh;
1306}
1307
1308static int ext4_set_bitmap_checksums(struct super_block *sb,
1309 ext4_group_t group,
1310 struct ext4_group_desc *gdp,
1311 struct ext4_new_group_data *group_data)
1312{
1313 struct buffer_head *bh;
1314
1315 if (!ext4_has_metadata_csum(sb))
1316 return 0;
1317
1318 bh = ext4_get_bitmap(sb, group_data->inode_bitmap);
1319 if (!bh)
1320 return -EIO;
1321 ext4_inode_bitmap_csum_set(sb, group, gdp, bh,
1322 EXT4_INODES_PER_GROUP(sb) / 8);
1323 brelse(bh);
1324
1325 bh = ext4_get_bitmap(sb, group_data->block_bitmap);
1326 if (!bh)
1327 return -EIO;
1328 ext4_block_bitmap_csum_set(sb, group, gdp, bh);
1329 brelse(bh);
1330
1331 return 0;
1332}
1333
1334/*
1335 * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg
1336 */
1337static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb,
1338 struct ext4_new_flex_group_data *flex_gd)
1339{
1340 struct ext4_new_group_data *group_data = flex_gd->groups;
1341 struct ext4_group_desc *gdp;
1342 struct ext4_sb_info *sbi = EXT4_SB(sb);
1343 struct buffer_head *gdb_bh;
1344 ext4_group_t group;
1345 __u16 *bg_flags = flex_gd->bg_flags;
1346 int i, gdb_off, gdb_num, err = 0;
1347
1348
1349 for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) {
1350 group = group_data->group;
1351
1352 gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
1353 gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1354
1355 /*
1356 * get_write_access() has been called on gdb_bh by ext4_add_new_desc().
1357 */
1358 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc, gdb_num);
1359 /* Update group descriptor block for new group */
1360 gdp = (struct ext4_group_desc *)(gdb_bh->b_data +
1361 gdb_off * EXT4_DESC_SIZE(sb));
1362
1363 memset(gdp, 0, EXT4_DESC_SIZE(sb));
1364 ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap);
1365 ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap);
1366 err = ext4_set_bitmap_checksums(sb, group, gdp, group_data);
1367 if (err) {
1368 ext4_std_error(sb, err);
1369 break;
1370 }
1371
1372 ext4_inode_table_set(sb, gdp, group_data->inode_table);
1373 ext4_free_group_clusters_set(sb, gdp,
1374 group_data->free_clusters_count);
1375 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
1376 if (ext4_has_group_desc_csum(sb))
1377 ext4_itable_unused_set(sb, gdp,
1378 EXT4_INODES_PER_GROUP(sb));
1379 gdp->bg_flags = cpu_to_le16(*bg_flags);
1380 ext4_group_desc_csum_set(sb, group, gdp);
1381
1382 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
1383 if (unlikely(err)) {
1384 ext4_std_error(sb, err);
1385 break;
1386 }
1387
1388 /*
1389 * We can allocate memory for mb_alloc based on the new group
1390 * descriptor
1391 */
1392 err = ext4_mb_add_groupinfo(sb, group, gdp);
1393 if (err)
1394 break;
1395 }
1396 return err;
1397}
1398
1399static void ext4_add_overhead(struct super_block *sb,
1400 const ext4_fsblk_t overhead)
1401{
1402 struct ext4_sb_info *sbi = EXT4_SB(sb);
1403 struct ext4_super_block *es = sbi->s_es;
1404
1405 sbi->s_overhead += overhead;
1406 es->s_overhead_clusters = cpu_to_le32(sbi->s_overhead);
1407 smp_wmb();
1408}
1409
1410/*
1411 * ext4_update_super() updates the super block so that the newly added
1412 * groups can be seen by the filesystem.
1413 *
1414 * @sb: super block
1415 * @flex_gd: new added groups
1416 */
1417static void ext4_update_super(struct super_block *sb,
1418 struct ext4_new_flex_group_data *flex_gd)
1419{
1420 ext4_fsblk_t blocks_count = 0;
1421 ext4_fsblk_t free_blocks = 0;
1422 ext4_fsblk_t reserved_blocks = 0;
1423 struct ext4_new_group_data *group_data = flex_gd->groups;
1424 struct ext4_sb_info *sbi = EXT4_SB(sb);
1425 struct ext4_super_block *es = sbi->s_es;
1426 int i;
1427
1428 BUG_ON(flex_gd->count == 0 || group_data == NULL);
1429 /*
1430 * Make the new blocks and inodes valid next. We do this before
1431 * increasing the group count so that once the group is enabled,
1432 * all of its blocks and inodes are already valid.
1433 *
1434 * We always allocate group-by-group, then block-by-block or
1435 * inode-by-inode within a group, so enabling these
1436 * blocks/inodes before the group is live won't actually let us
1437 * allocate the new space yet.
1438 */
1439 for (i = 0; i < flex_gd->count; i++) {
1440 blocks_count += group_data[i].blocks_count;
1441 free_blocks += EXT4_C2B(sbi, group_data[i].free_clusters_count);
1442 }
1443
1444 reserved_blocks = ext4_r_blocks_count(es) * 100;
1445 reserved_blocks = div64_u64(reserved_blocks, ext4_blocks_count(es));
1446 reserved_blocks *= blocks_count;
1447 do_div(reserved_blocks, 100);
1448
1449 lock_buffer(sbi->s_sbh);
1450 ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count);
1451 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks);
1452 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) *
1453 flex_gd->count);
1454 le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) *
1455 flex_gd->count);
1456
1457 ext4_debug("free blocks count %llu", ext4_free_blocks_count(es));
1458 /*
1459 * We need to protect s_groups_count against other CPUs seeing
1460 * inconsistent state in the superblock.
1461 *
1462 * The precise rules we use are:
1463 *
1464 * * Writers must perform a smp_wmb() after updating all
1465 * dependent data and before modifying the groups count
1466 *
1467 * * Readers must perform an smp_rmb() after reading the groups
1468 * count and before reading any dependent data.
1469 *
1470 * NB. These rules can be relaxed when checking the group count
1471 * while freeing data, as we can only allocate from a block
1472 * group after serialising against the group count, and we can
1473 * only then free after serialising in turn against that
1474 * allocation.
1475 */
1476 smp_wmb();
1477
1478 /* Update the global fs size fields */
1479 sbi->s_groups_count += flex_gd->count;
1480 sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
1481 (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
1482
1483 /* Update the reserved block counts only once the new group is
1484 * active. */
1485 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) +
1486 reserved_blocks);
1487
1488 /* Update the free space counts */
1489 percpu_counter_add(&sbi->s_freeclusters_counter,
1490 EXT4_NUM_B2C(sbi, free_blocks));
1491 percpu_counter_add(&sbi->s_freeinodes_counter,
1492 EXT4_INODES_PER_GROUP(sb) * flex_gd->count);
1493
1494 ext4_debug("free blocks count %llu",
1495 percpu_counter_read(&sbi->s_freeclusters_counter));
1496 if (ext4_has_feature_flex_bg(sb) && sbi->s_log_groups_per_flex) {
1497 ext4_group_t flex_group;
1498 struct flex_groups *fg;
1499
1500 flex_group = ext4_flex_group(sbi, group_data[0].group);
1501 fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
1502 atomic64_add(EXT4_NUM_B2C(sbi, free_blocks),
1503 &fg->free_clusters);
1504 atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count,
1505 &fg->free_inodes);
1506 }
1507
1508 /*
1509 * Update the fs overhead information.
1510 *
1511 * For bigalloc, if the superblock already has a properly calculated
1512 * overhead, update it with a value based on numbers already computed
1513 * above for the newly allocated capacity.
1514 */
1515 if (ext4_has_feature_bigalloc(sb) && (sbi->s_overhead != 0))
1516 ext4_add_overhead(sb,
1517 EXT4_NUM_B2C(sbi, blocks_count - free_blocks));
1518 else
1519 ext4_calculate_overhead(sb);
1520 es->s_overhead_clusters = cpu_to_le32(sbi->s_overhead);
1521
1522 ext4_superblock_csum_set(sb);
1523 unlock_buffer(sbi->s_sbh);
1524 if (test_opt(sb, DEBUG))
1525 printk(KERN_DEBUG "EXT4-fs: added group %u:"
1526 "%llu blocks(%llu free %llu reserved)\n", flex_gd->count,
1527 blocks_count, free_blocks, reserved_blocks);
1528}
1529
1530/* Add a flex group to an fs. Ensure we handle all possible error conditions
1531 * _before_ we start modifying the filesystem, because we cannot abort the
1532 * transaction and not have it write the data to disk.
1533 */
1534static int ext4_flex_group_add(struct super_block *sb,
1535 struct inode *resize_inode,
1536 struct ext4_new_flex_group_data *flex_gd)
1537{
1538 struct ext4_sb_info *sbi = EXT4_SB(sb);
1539 struct ext4_super_block *es = sbi->s_es;
1540 ext4_fsblk_t o_blocks_count;
1541 ext4_grpblk_t last;
1542 ext4_group_t group;
1543 handle_t *handle;
1544 unsigned reserved_gdb;
1545 int err = 0, err2 = 0, credit;
1546
1547 BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags);
1548
1549 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
1550 o_blocks_count = ext4_blocks_count(es);
1551 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1552 BUG_ON(last);
1553
1554 err = setup_new_flex_group_blocks(sb, flex_gd);
1555 if (err)
1556 goto exit;
1557 /*
1558 * We will always be modifying at least the superblock and GDT
1559 * blocks. If we are adding a group past the last current GDT block,
1560 * we will also modify the inode and the dindirect block. If we
1561 * are adding a group with superblock/GDT backups we will also
1562 * modify each of the reserved GDT dindirect blocks.
1563 */
1564 credit = 3; /* sb, resize inode, resize inode dindirect */
1565 /* GDT blocks */
1566 credit += 1 + DIV_ROUND_UP(flex_gd->count, EXT4_DESC_PER_BLOCK(sb));
1567 credit += reserved_gdb; /* Reserved GDT dindirect blocks */
1568 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credit);
1569 if (IS_ERR(handle)) {
1570 err = PTR_ERR(handle);
1571 goto exit;
1572 }
1573
1574 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
1575 err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
1576 EXT4_JTR_NONE);
1577 if (err)
1578 goto exit_journal;
1579
1580 group = flex_gd->groups[0].group;
1581 BUG_ON(group != sbi->s_groups_count);
1582 err = ext4_add_new_descs(handle, sb, group,
1583 resize_inode, flex_gd->count);
1584 if (err)
1585 goto exit_journal;
1586
1587 err = ext4_setup_new_descs(handle, sb, flex_gd);
1588 if (err)
1589 goto exit_journal;
1590
1591 ext4_update_super(sb, flex_gd);
1592
1593 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
1594
1595exit_journal:
1596 err2 = ext4_journal_stop(handle);
1597 if (!err)
1598 err = err2;
1599
1600 if (!err) {
1601 int gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1602 int gdb_num_end = ((group + flex_gd->count - 1) /
1603 EXT4_DESC_PER_BLOCK(sb));
1604 int meta_bg = ext4_has_feature_meta_bg(sb);
1605 sector_t old_gdb = 0;
1606
1607 update_backups(sb, ext4_group_first_block_no(sb, 0),
1608 (char *)es, sizeof(struct ext4_super_block), 0);
1609 for (; gdb_num <= gdb_num_end; gdb_num++) {
1610 struct buffer_head *gdb_bh;
1611
1612 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc,
1613 gdb_num);
1614 if (old_gdb == gdb_bh->b_blocknr)
1615 continue;
1616 update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data,
1617 gdb_bh->b_size, meta_bg);
1618 old_gdb = gdb_bh->b_blocknr;
1619 }
1620 }
1621exit:
1622 return err;
1623}
1624
1625static int ext4_setup_next_flex_gd(struct super_block *sb,
1626 struct ext4_new_flex_group_data *flex_gd,
1627 ext4_fsblk_t n_blocks_count,
1628 unsigned long flexbg_size)
1629{
1630 struct ext4_sb_info *sbi = EXT4_SB(sb);
1631 struct ext4_super_block *es = sbi->s_es;
1632 struct ext4_new_group_data *group_data = flex_gd->groups;
1633 ext4_fsblk_t o_blocks_count;
1634 ext4_group_t n_group;
1635 ext4_group_t group;
1636 ext4_group_t last_group;
1637 ext4_grpblk_t last;
1638 ext4_grpblk_t clusters_per_group;
1639 unsigned long i;
1640
1641 clusters_per_group = EXT4_CLUSTERS_PER_GROUP(sb);
1642
1643 o_blocks_count = ext4_blocks_count(es);
1644
1645 if (o_blocks_count == n_blocks_count)
1646 return 0;
1647
1648 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1649 BUG_ON(last);
1650 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last);
1651
1652 last_group = group | (flexbg_size - 1);
1653 if (last_group > n_group)
1654 last_group = n_group;
1655
1656 flex_gd->count = last_group - group + 1;
1657
1658 for (i = 0; i < flex_gd->count; i++) {
1659 int overhead;
1660
1661 group_data[i].group = group + i;
1662 group_data[i].blocks_count = EXT4_BLOCKS_PER_GROUP(sb);
1663 overhead = ext4_group_overhead_blocks(sb, group + i);
1664 group_data[i].mdata_blocks = overhead;
1665 group_data[i].free_clusters_count = EXT4_CLUSTERS_PER_GROUP(sb);
1666 if (ext4_has_group_desc_csum(sb)) {
1667 flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT |
1668 EXT4_BG_INODE_UNINIT;
1669 if (!test_opt(sb, INIT_INODE_TABLE))
1670 flex_gd->bg_flags[i] |= EXT4_BG_INODE_ZEROED;
1671 } else
1672 flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED;
1673 }
1674
1675 if (last_group == n_group && ext4_has_group_desc_csum(sb))
1676 /* We need to initialize block bitmap of last group. */
1677 flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT;
1678
1679 if ((last_group == n_group) && (last != clusters_per_group - 1)) {
1680 group_data[i - 1].blocks_count = EXT4_C2B(sbi, last + 1);
1681 group_data[i - 1].free_clusters_count -= clusters_per_group -
1682 last - 1;
1683 }
1684
1685 return 1;
1686}
1687
1688/* Add group descriptor data to an existing or new group descriptor block.
1689 * Ensure we handle all possible error conditions _before_ we start modifying
1690 * the filesystem, because we cannot abort the transaction and not have it
1691 * write the data to disk.
1692 *
1693 * If we are on a GDT block boundary, we need to get the reserved GDT block.
1694 * Otherwise, we may need to add backup GDT blocks for a sparse group.
1695 *
1696 * We only need to hold the superblock lock while we are actually adding
1697 * in the new group's counts to the superblock. Prior to that we have
1698 * not really "added" the group at all. We re-check that we are still
1699 * adding in the last group in case things have changed since verifying.
1700 */
1701int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
1702{
1703 struct ext4_new_flex_group_data flex_gd;
1704 struct ext4_sb_info *sbi = EXT4_SB(sb);
1705 struct ext4_super_block *es = sbi->s_es;
1706 int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
1707 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
1708 struct inode *inode = NULL;
1709 int gdb_off;
1710 int err;
1711 __u16 bg_flags = 0;
1712
1713 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb);
1714
1715 if (gdb_off == 0 && !ext4_has_feature_sparse_super(sb)) {
1716 ext4_warning(sb, "Can't resize non-sparse filesystem further");
1717 return -EPERM;
1718 }
1719
1720 if (ext4_blocks_count(es) + input->blocks_count <
1721 ext4_blocks_count(es)) {
1722 ext4_warning(sb, "blocks_count overflow");
1723 return -EINVAL;
1724 }
1725
1726 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) <
1727 le32_to_cpu(es->s_inodes_count)) {
1728 ext4_warning(sb, "inodes_count overflow");
1729 return -EINVAL;
1730 }
1731
1732 if (reserved_gdb || gdb_off == 0) {
1733 if (!ext4_has_feature_resize_inode(sb) ||
1734 !le16_to_cpu(es->s_reserved_gdt_blocks)) {
1735 ext4_warning(sb,
1736 "No reserved GDT blocks, can't resize");
1737 return -EPERM;
1738 }
1739 inode = ext4_iget(sb, EXT4_RESIZE_INO, EXT4_IGET_SPECIAL);
1740 if (IS_ERR(inode)) {
1741 ext4_warning(sb, "Error opening resize inode");
1742 return PTR_ERR(inode);
1743 }
1744 }
1745
1746
1747 err = verify_group_input(sb, input);
1748 if (err)
1749 goto out;
1750
1751 err = ext4_alloc_flex_bg_array(sb, input->group + 1);
1752 if (err)
1753 goto out;
1754
1755 err = ext4_mb_alloc_groupinfo(sb, input->group + 1);
1756 if (err)
1757 goto out;
1758
1759 flex_gd.count = 1;
1760 flex_gd.groups = input;
1761 flex_gd.bg_flags = &bg_flags;
1762 err = ext4_flex_group_add(sb, inode, &flex_gd);
1763out:
1764 iput(inode);
1765 return err;
1766} /* ext4_group_add */
1767
1768/*
1769 * extend a group without checking assuming that checking has been done.
1770 */
1771static int ext4_group_extend_no_check(struct super_block *sb,
1772 ext4_fsblk_t o_blocks_count, ext4_grpblk_t add)
1773{
1774 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1775 handle_t *handle;
1776 int err = 0, err2;
1777
1778 /* We will update the superblock, one block bitmap, and
1779 * one group descriptor via ext4_group_add_blocks().
1780 */
1781 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, 3);
1782 if (IS_ERR(handle)) {
1783 err = PTR_ERR(handle);
1784 ext4_warning(sb, "error %d on journal start", err);
1785 return err;
1786 }
1787
1788 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
1789 err = ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh,
1790 EXT4_JTR_NONE);
1791 if (err) {
1792 ext4_warning(sb, "error %d on journal write access", err);
1793 goto errout;
1794 }
1795
1796 lock_buffer(EXT4_SB(sb)->s_sbh);
1797 ext4_blocks_count_set(es, o_blocks_count + add);
1798 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add);
1799 ext4_superblock_csum_set(sb);
1800 unlock_buffer(EXT4_SB(sb)->s_sbh);
1801 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
1802 o_blocks_count + add);
1803 /* We add the blocks to the bitmap and set the group need init bit */
1804 err = ext4_group_add_blocks(handle, sb, o_blocks_count, add);
1805 if (err)
1806 goto errout;
1807 ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
1808 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
1809 o_blocks_count + add);
1810errout:
1811 err2 = ext4_journal_stop(handle);
1812 if (err2 && !err)
1813 err = err2;
1814
1815 if (!err) {
1816 if (test_opt(sb, DEBUG))
1817 printk(KERN_DEBUG "EXT4-fs: extended group to %llu "
1818 "blocks\n", ext4_blocks_count(es));
1819 update_backups(sb, ext4_group_first_block_no(sb, 0),
1820 (char *)es, sizeof(struct ext4_super_block), 0);
1821 }
1822 return err;
1823}
1824
1825/*
1826 * Extend the filesystem to the new number of blocks specified. This entry
1827 * point is only used to extend the current filesystem to the end of the last
1828 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>"
1829 * for emergencies (because it has no dependencies on reserved blocks).
1830 *
1831 * If we _really_ wanted, we could use default values to call ext4_group_add()
1832 * allow the "remount" trick to work for arbitrary resizing, assuming enough
1833 * GDT blocks are reserved to grow to the desired size.
1834 */
1835int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
1836 ext4_fsblk_t n_blocks_count)
1837{
1838 ext4_fsblk_t o_blocks_count;
1839 ext4_grpblk_t last;
1840 ext4_grpblk_t add;
1841 struct buffer_head *bh;
1842 ext4_group_t group;
1843
1844 o_blocks_count = ext4_blocks_count(es);
1845
1846 if (test_opt(sb, DEBUG))
1847 ext4_msg(sb, KERN_DEBUG,
1848 "extending last group from %llu to %llu blocks",
1849 o_blocks_count, n_blocks_count);
1850
1851 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
1852 return 0;
1853
1854 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1855 ext4_msg(sb, KERN_ERR,
1856 "filesystem too large to resize to %llu blocks safely",
1857 n_blocks_count);
1858 return -EINVAL;
1859 }
1860
1861 if (n_blocks_count < o_blocks_count) {
1862 ext4_warning(sb, "can't shrink FS - resize aborted");
1863 return -EINVAL;
1864 }
1865
1866 /* Handle the remaining blocks in the last group only. */
1867 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1868
1869 if (last == 0) {
1870 ext4_warning(sb, "need to use ext2online to resize further");
1871 return -EPERM;
1872 }
1873
1874 add = EXT4_BLOCKS_PER_GROUP(sb) - last;
1875
1876 if (o_blocks_count + add < o_blocks_count) {
1877 ext4_warning(sb, "blocks_count overflow");
1878 return -EINVAL;
1879 }
1880
1881 if (o_blocks_count + add > n_blocks_count)
1882 add = n_blocks_count - o_blocks_count;
1883
1884 if (o_blocks_count + add < n_blocks_count)
1885 ext4_warning(sb, "will only finish group (%llu blocks, %u new)",
1886 o_blocks_count + add, add);
1887
1888 /* See if the device is actually as big as what was requested */
1889 bh = ext4_sb_bread(sb, o_blocks_count + add - 1, 0);
1890 if (IS_ERR(bh)) {
1891 ext4_warning(sb, "can't read last block, resize aborted");
1892 return -ENOSPC;
1893 }
1894 brelse(bh);
1895
1896 return ext4_group_extend_no_check(sb, o_blocks_count, add);
1897} /* ext4_group_extend */
1898
1899
1900static int num_desc_blocks(struct super_block *sb, ext4_group_t groups)
1901{
1902 return (groups + EXT4_DESC_PER_BLOCK(sb) - 1) / EXT4_DESC_PER_BLOCK(sb);
1903}
1904
1905/*
1906 * Release the resize inode and drop the resize_inode feature if there
1907 * are no more reserved gdt blocks, and then convert the file system
1908 * to enable meta_bg
1909 */
1910static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode)
1911{
1912 handle_t *handle;
1913 struct ext4_sb_info *sbi = EXT4_SB(sb);
1914 struct ext4_super_block *es = sbi->s_es;
1915 struct ext4_inode_info *ei = EXT4_I(inode);
1916 ext4_fsblk_t nr;
1917 int i, ret, err = 0;
1918 int credits = 1;
1919
1920 ext4_msg(sb, KERN_INFO, "Converting file system to meta_bg");
1921 if (inode) {
1922 if (es->s_reserved_gdt_blocks) {
1923 ext4_error(sb, "Unexpected non-zero "
1924 "s_reserved_gdt_blocks");
1925 return -EPERM;
1926 }
1927
1928 /* Do a quick sanity check of the resize inode */
1929 if (inode->i_blocks != 1 << (inode->i_blkbits -
1930 (9 - sbi->s_cluster_bits)))
1931 goto invalid_resize_inode;
1932 for (i = 0; i < EXT4_N_BLOCKS; i++) {
1933 if (i == EXT4_DIND_BLOCK) {
1934 if (ei->i_data[i])
1935 continue;
1936 else
1937 goto invalid_resize_inode;
1938 }
1939 if (ei->i_data[i])
1940 goto invalid_resize_inode;
1941 }
1942 credits += 3; /* block bitmap, bg descriptor, resize inode */
1943 }
1944
1945 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credits);
1946 if (IS_ERR(handle))
1947 return PTR_ERR(handle);
1948
1949 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
1950 err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
1951 EXT4_JTR_NONE);
1952 if (err)
1953 goto errout;
1954
1955 lock_buffer(sbi->s_sbh);
1956 ext4_clear_feature_resize_inode(sb);
1957 ext4_set_feature_meta_bg(sb);
1958 sbi->s_es->s_first_meta_bg =
1959 cpu_to_le32(num_desc_blocks(sb, sbi->s_groups_count));
1960 ext4_superblock_csum_set(sb);
1961 unlock_buffer(sbi->s_sbh);
1962
1963 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
1964 if (err) {
1965 ext4_std_error(sb, err);
1966 goto errout;
1967 }
1968
1969 if (inode) {
1970 nr = le32_to_cpu(ei->i_data[EXT4_DIND_BLOCK]);
1971 ext4_free_blocks(handle, inode, NULL, nr, 1,
1972 EXT4_FREE_BLOCKS_METADATA |
1973 EXT4_FREE_BLOCKS_FORGET);
1974 ei->i_data[EXT4_DIND_BLOCK] = 0;
1975 inode->i_blocks = 0;
1976
1977 err = ext4_mark_inode_dirty(handle, inode);
1978 if (err)
1979 ext4_std_error(sb, err);
1980 }
1981
1982errout:
1983 ret = ext4_journal_stop(handle);
1984 if (!err)
1985 err = ret;
1986 return ret;
1987
1988invalid_resize_inode:
1989 ext4_error(sb, "corrupted/inconsistent resize inode");
1990 return -EINVAL;
1991}
1992
1993/*
1994 * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count
1995 *
1996 * @sb: super block of the fs to be resized
1997 * @n_blocks_count: the number of blocks resides in the resized fs
1998 */
1999int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
2000{
2001 struct ext4_new_flex_group_data *flex_gd = NULL;
2002 struct ext4_sb_info *sbi = EXT4_SB(sb);
2003 struct ext4_super_block *es = sbi->s_es;
2004 struct buffer_head *bh;
2005 struct inode *resize_inode = NULL;
2006 ext4_grpblk_t add, offset;
2007 unsigned long n_desc_blocks;
2008 unsigned long o_desc_blocks;
2009 ext4_group_t o_group;
2010 ext4_group_t n_group;
2011 ext4_fsblk_t o_blocks_count;
2012 ext4_fsblk_t n_blocks_count_retry = 0;
2013 unsigned long last_update_time = 0;
2014 int err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex;
2015 int meta_bg;
2016
2017 /* See if the device is actually as big as what was requested */
2018 bh = ext4_sb_bread(sb, n_blocks_count - 1, 0);
2019 if (IS_ERR(bh)) {
2020 ext4_warning(sb, "can't read last block, resize aborted");
2021 return -ENOSPC;
2022 }
2023 brelse(bh);
2024
2025 /*
2026 * For bigalloc, trim the requested size to the nearest cluster
2027 * boundary to avoid creating an unusable filesystem. We do this
2028 * silently, instead of returning an error, to avoid breaking
2029 * callers that blindly resize the filesystem to the full size of
2030 * the underlying block device.
2031 */
2032 if (ext4_has_feature_bigalloc(sb))
2033 n_blocks_count &= ~((1 << EXT4_CLUSTER_BITS(sb)) - 1);
2034
2035retry:
2036 o_blocks_count = ext4_blocks_count(es);
2037
2038 ext4_msg(sb, KERN_INFO, "resizing filesystem from %llu "
2039 "to %llu blocks", o_blocks_count, n_blocks_count);
2040
2041 if (n_blocks_count < o_blocks_count) {
2042 /* On-line shrinking not supported */
2043 ext4_warning(sb, "can't shrink FS - resize aborted");
2044 return -EINVAL;
2045 }
2046
2047 if (n_blocks_count == o_blocks_count)
2048 /* Nothing need to do */
2049 return 0;
2050
2051 n_group = ext4_get_group_number(sb, n_blocks_count - 1);
2052 if (n_group >= (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) {
2053 ext4_warning(sb, "resize would cause inodes_count overflow");
2054 return -EINVAL;
2055 }
2056 ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset);
2057
2058 n_desc_blocks = num_desc_blocks(sb, n_group + 1);
2059 o_desc_blocks = num_desc_blocks(sb, sbi->s_groups_count);
2060
2061 meta_bg = ext4_has_feature_meta_bg(sb);
2062
2063 if (ext4_has_feature_resize_inode(sb)) {
2064 if (meta_bg) {
2065 ext4_error(sb, "resize_inode and meta_bg enabled "
2066 "simultaneously");
2067 return -EINVAL;
2068 }
2069 if (n_desc_blocks > o_desc_blocks +
2070 le16_to_cpu(es->s_reserved_gdt_blocks)) {
2071 n_blocks_count_retry = n_blocks_count;
2072 n_desc_blocks = o_desc_blocks +
2073 le16_to_cpu(es->s_reserved_gdt_blocks);
2074 n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb);
2075 n_blocks_count = (ext4_fsblk_t)n_group *
2076 EXT4_BLOCKS_PER_GROUP(sb) +
2077 le32_to_cpu(es->s_first_data_block);
2078 n_group--; /* set to last group number */
2079 }
2080
2081 if (!resize_inode)
2082 resize_inode = ext4_iget(sb, EXT4_RESIZE_INO,
2083 EXT4_IGET_SPECIAL);
2084 if (IS_ERR(resize_inode)) {
2085 ext4_warning(sb, "Error opening resize inode");
2086 return PTR_ERR(resize_inode);
2087 }
2088 }
2089
2090 if ((!resize_inode && !meta_bg) || n_blocks_count == o_blocks_count) {
2091 err = ext4_convert_meta_bg(sb, resize_inode);
2092 if (err)
2093 goto out;
2094 if (resize_inode) {
2095 iput(resize_inode);
2096 resize_inode = NULL;
2097 }
2098 if (n_blocks_count_retry) {
2099 n_blocks_count = n_blocks_count_retry;
2100 n_blocks_count_retry = 0;
2101 goto retry;
2102 }
2103 }
2104
2105 /*
2106 * Make sure the last group has enough space so that it's
2107 * guaranteed to have enough space for all metadata blocks
2108 * that it might need to hold. (We might not need to store
2109 * the inode table blocks in the last block group, but there
2110 * will be cases where this might be needed.)
2111 */
2112 if ((ext4_group_first_block_no(sb, n_group) +
2113 ext4_group_overhead_blocks(sb, n_group) + 2 +
2114 sbi->s_itb_per_group + sbi->s_cluster_ratio) >= n_blocks_count) {
2115 n_blocks_count = ext4_group_first_block_no(sb, n_group);
2116 n_group--;
2117 n_blocks_count_retry = 0;
2118 if (resize_inode) {
2119 iput(resize_inode);
2120 resize_inode = NULL;
2121 }
2122 goto retry;
2123 }
2124
2125 /* extend the last group */
2126 if (n_group == o_group)
2127 add = n_blocks_count - o_blocks_count;
2128 else
2129 add = EXT4_C2B(sbi, EXT4_CLUSTERS_PER_GROUP(sb) - (offset + 1));
2130 if (add > 0) {
2131 err = ext4_group_extend_no_check(sb, o_blocks_count, add);
2132 if (err)
2133 goto out;
2134 }
2135
2136 if (ext4_blocks_count(es) == n_blocks_count && n_blocks_count_retry == 0)
2137 goto out;
2138
2139 err = ext4_alloc_flex_bg_array(sb, n_group + 1);
2140 if (err)
2141 goto out;
2142
2143 err = ext4_mb_alloc_groupinfo(sb, n_group + 1);
2144 if (err)
2145 goto out;
2146
2147 flex_gd = alloc_flex_gd(flexbg_size);
2148 if (flex_gd == NULL) {
2149 err = -ENOMEM;
2150 goto out;
2151 }
2152
2153 /* Add flex groups. Note that a regular group is a
2154 * flex group with 1 group.
2155 */
2156 while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count,
2157 flexbg_size)) {
2158 if (time_is_before_jiffies(last_update_time + HZ * 10)) {
2159 if (last_update_time)
2160 ext4_msg(sb, KERN_INFO,
2161 "resized to %llu blocks",
2162 ext4_blocks_count(es));
2163 last_update_time = jiffies;
2164 }
2165 if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0)
2166 break;
2167 err = ext4_flex_group_add(sb, resize_inode, flex_gd);
2168 if (unlikely(err))
2169 break;
2170 }
2171
2172 if (!err && n_blocks_count_retry) {
2173 n_blocks_count = n_blocks_count_retry;
2174 n_blocks_count_retry = 0;
2175 free_flex_gd(flex_gd);
2176 flex_gd = NULL;
2177 if (resize_inode) {
2178 iput(resize_inode);
2179 resize_inode = NULL;
2180 }
2181 goto retry;
2182 }
2183
2184out:
2185 if (flex_gd)
2186 free_flex_gd(flex_gd);
2187 if (resize_inode != NULL)
2188 iput(resize_inode);
2189 if (err)
2190 ext4_warning(sb, "error (%d) occurred during "
2191 "file system resize", err);
2192 ext4_msg(sb, KERN_INFO, "resized filesystem to %llu",
2193 ext4_blocks_count(es));
2194 return err;
2195}