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