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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
137/*
138 * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex
139 * group each time.
140 */
141struct ext4_new_flex_group_data {
142 struct ext4_new_group_data *groups; /* new_group_data for groups
143 in the flex group */
144 __u16 *bg_flags; /* block group flags of groups
145 in @groups */
146 ext4_group_t count; /* number of groups in @groups
147 */
148};
149
150/*
151 * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of
152 * @flexbg_size.
153 *
154 * Returns NULL on failure otherwise address of the allocated structure.
155 */
156static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size)
157{
158 struct ext4_new_flex_group_data *flex_gd;
159
160 flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS);
161 if (flex_gd == NULL)
162 goto out3;
163
164 if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_flex_group_data))
165 goto out2;
166 flex_gd->count = flexbg_size;
167
168 flex_gd->groups = kmalloc(sizeof(struct ext4_new_group_data) *
169 flexbg_size, GFP_NOFS);
170 if (flex_gd->groups == NULL)
171 goto out2;
172
173 flex_gd->bg_flags = kmalloc(flexbg_size * sizeof(__u16), GFP_NOFS);
174 if (flex_gd->bg_flags == NULL)
175 goto out1;
176
177 return flex_gd;
178
179out1:
180 kfree(flex_gd->groups);
181out2:
182 kfree(flex_gd);
183out3:
184 return NULL;
185}
186
187static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd)
188{
189 kfree(flex_gd->bg_flags);
190 kfree(flex_gd->groups);
191 kfree(flex_gd);
192}
193
194/*
195 * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps
196 * and inode tables for a flex group.
197 *
198 * This function is used by 64bit-resize. Note that this function allocates
199 * group tables from the 1st group of groups contained by @flexgd, which may
200 * be a partial of a flex group.
201 *
202 * @sb: super block of fs to which the groups belongs
203 */
204static void ext4_alloc_group_tables(struct super_block *sb,
205 struct ext4_new_flex_group_data *flex_gd,
206 int flexbg_size)
207{
208 struct ext4_new_group_data *group_data = flex_gd->groups;
209 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
210 ext4_fsblk_t start_blk;
211 ext4_fsblk_t last_blk;
212 ext4_group_t src_group;
213 ext4_group_t bb_index = 0;
214 ext4_group_t ib_index = 0;
215 ext4_group_t it_index = 0;
216 ext4_group_t group;
217 ext4_group_t last_group;
218 unsigned overhead;
219
220 BUG_ON(flex_gd->count == 0 || group_data == NULL);
221
222 src_group = group_data[0].group;
223 last_group = src_group + flex_gd->count - 1;
224
225 BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) !=
226 (last_group & ~(flexbg_size - 1))));
227next_group:
228 group = group_data[0].group;
229 start_blk = ext4_group_first_block_no(sb, src_group);
230 last_blk = start_blk + group_data[src_group - group].blocks_count;
231
232 overhead = ext4_bg_has_super(sb, src_group) ?
233 (1 + ext4_bg_num_gdb(sb, src_group) +
234 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
235
236 start_blk += overhead;
237
238 BUG_ON(src_group >= group_data[0].group + flex_gd->count);
239 /* We collect contiguous blocks as much as possible. */
240 src_group++;
241 for (; src_group <= last_group; src_group++)
242 if (!ext4_bg_has_super(sb, src_group))
243 last_blk += group_data[src_group - group].blocks_count;
244 else
245 break;
246
247 /* Allocate block bitmaps */
248 for (; bb_index < flex_gd->count; bb_index++) {
249 if (start_blk >= last_blk)
250 goto next_group;
251 group_data[bb_index].block_bitmap = start_blk++;
252 ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL);
253 group -= group_data[0].group;
254 group_data[group].free_blocks_count--;
255 if (flexbg_size > 1)
256 flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
257 }
258
259 /* Allocate inode bitmaps */
260 for (; ib_index < flex_gd->count; ib_index++) {
261 if (start_blk >= last_blk)
262 goto next_group;
263 group_data[ib_index].inode_bitmap = start_blk++;
264 ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL);
265 group -= group_data[0].group;
266 group_data[group].free_blocks_count--;
267 if (flexbg_size > 1)
268 flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
269 }
270
271 /* Allocate inode tables */
272 for (; it_index < flex_gd->count; it_index++) {
273 if (start_blk + EXT4_SB(sb)->s_itb_per_group > last_blk)
274 goto next_group;
275 group_data[it_index].inode_table = start_blk;
276 ext4_get_group_no_and_offset(sb, start_blk, &group, NULL);
277 group -= group_data[0].group;
278 group_data[group].free_blocks_count -=
279 EXT4_SB(sb)->s_itb_per_group;
280 if (flexbg_size > 1)
281 flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
282
283 start_blk += EXT4_SB(sb)->s_itb_per_group;
284 }
285
286 if (test_opt(sb, DEBUG)) {
287 int i;
288 group = group_data[0].group;
289
290 printk(KERN_DEBUG "EXT4-fs: adding a flex group with "
291 "%d groups, flexbg size is %d:\n", flex_gd->count,
292 flexbg_size);
293
294 for (i = 0; i < flex_gd->count; i++) {
295 printk(KERN_DEBUG "adding %s group %u: %u "
296 "blocks (%d free)\n",
297 ext4_bg_has_super(sb, group + i) ? "normal" :
298 "no-super", group + i,
299 group_data[i].blocks_count,
300 group_data[i].free_blocks_count);
301 }
302 }
303}
304
305static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
306 ext4_fsblk_t blk)
307{
308 struct buffer_head *bh;
309 int err;
310
311 bh = sb_getblk(sb, blk);
312 if (!bh)
313 return ERR_PTR(-EIO);
314 if ((err = ext4_journal_get_write_access(handle, bh))) {
315 brelse(bh);
316 bh = ERR_PTR(err);
317 } else {
318 memset(bh->b_data, 0, sb->s_blocksize);
319 set_buffer_uptodate(bh);
320 }
321
322 return bh;
323}
324
325/*
326 * If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA.
327 * If that fails, restart the transaction & regain write access for the
328 * buffer head which is used for block_bitmap modifications.
329 */
330static int extend_or_restart_transaction(handle_t *handle, int thresh)
331{
332 int err;
333
334 if (ext4_handle_has_enough_credits(handle, thresh))
335 return 0;
336
337 err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA);
338 if (err < 0)
339 return err;
340 if (err) {
341 err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA);
342 if (err)
343 return err;
344 }
345
346 return 0;
347}
348
349/*
350 * set_flexbg_block_bitmap() mark @count blocks starting from @block used.
351 *
352 * Helper function for ext4_setup_new_group_blocks() which set .
353 *
354 * @sb: super block
355 * @handle: journal handle
356 * @flex_gd: flex group data
357 */
358static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle,
359 struct ext4_new_flex_group_data *flex_gd,
360 ext4_fsblk_t block, ext4_group_t count)
361{
362 ext4_group_t count2;
363
364 ext4_debug("mark blocks [%llu/%u] used\n", block, count);
365 for (count2 = count; count > 0; count -= count2, block += count2) {
366 ext4_fsblk_t start;
367 struct buffer_head *bh;
368 ext4_group_t group;
369 int err;
370
371 ext4_get_group_no_and_offset(sb, block, &group, NULL);
372 start = ext4_group_first_block_no(sb, group);
373 group -= flex_gd->groups[0].group;
374
375 count2 = sb->s_blocksize * 8 - (block - start);
376 if (count2 > count)
377 count2 = count;
378
379 if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) {
380 BUG_ON(flex_gd->count > 1);
381 continue;
382 }
383
384 err = extend_or_restart_transaction(handle, 1);
385 if (err)
386 return err;
387
388 bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap);
389 if (!bh)
390 return -EIO;
391
392 err = ext4_journal_get_write_access(handle, bh);
393 if (err)
394 return err;
395 ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n", block,
396 block - start, count2);
397 ext4_set_bits(bh->b_data, block - start, count2);
398
399 err = ext4_handle_dirty_metadata(handle, NULL, bh);
400 if (unlikely(err))
401 return err;
402 brelse(bh);
403 }
404
405 return 0;
406}
407
408/*
409 * Set up the block and inode bitmaps, and the inode table for the new groups.
410 * This doesn't need to be part of the main transaction, since we are only
411 * changing blocks outside the actual filesystem. We still do journaling to
412 * ensure the recovery is correct in case of a failure just after resize.
413 * If any part of this fails, we simply abort the resize.
414 *
415 * setup_new_flex_group_blocks handles a flex group as follow:
416 * 1. copy super block and GDT, and initialize group tables if necessary.
417 * In this step, we only set bits in blocks bitmaps for blocks taken by
418 * super block and GDT.
419 * 2. allocate group tables in block bitmaps, that is, set bits in block
420 * bitmap for blocks taken by group tables.
421 */
422static int setup_new_flex_group_blocks(struct super_block *sb,
423 struct ext4_new_flex_group_data *flex_gd)
424{
425 int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group};
426 ext4_fsblk_t start;
427 ext4_fsblk_t block;
428 struct ext4_sb_info *sbi = EXT4_SB(sb);
429 struct ext4_super_block *es = sbi->s_es;
430 struct ext4_new_group_data *group_data = flex_gd->groups;
431 __u16 *bg_flags = flex_gd->bg_flags;
432 handle_t *handle;
433 ext4_group_t group, count;
434 struct buffer_head *bh = NULL;
435 int reserved_gdb, i, j, err = 0, err2;
436
437 BUG_ON(!flex_gd->count || !group_data ||
438 group_data[0].group != sbi->s_groups_count);
439
440 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
441
442 /* This transaction may be extended/restarted along the way */
443 handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
444 if (IS_ERR(handle))
445 return PTR_ERR(handle);
446
447 group = group_data[0].group;
448 for (i = 0; i < flex_gd->count; i++, group++) {
449 unsigned long gdblocks;
450
451 gdblocks = ext4_bg_num_gdb(sb, group);
452 start = ext4_group_first_block_no(sb, group);
453
454 /* Copy all of the GDT blocks into the backup in this group */
455 for (j = 0, block = start + 1; j < gdblocks; j++, block++) {
456 struct buffer_head *gdb;
457
458 ext4_debug("update backup group %#04llx\n", block);
459 err = extend_or_restart_transaction(handle, 1);
460 if (err)
461 goto out;
462
463 gdb = sb_getblk(sb, block);
464 if (!gdb) {
465 err = -EIO;
466 goto out;
467 }
468
469 err = ext4_journal_get_write_access(handle, gdb);
470 if (err) {
471 brelse(gdb);
472 goto out;
473 }
474 memcpy(gdb->b_data, sbi->s_group_desc[j]->b_data,
475 gdb->b_size);
476 set_buffer_uptodate(gdb);
477
478 err = ext4_handle_dirty_metadata(handle, NULL, gdb);
479 if (unlikely(err)) {
480 brelse(gdb);
481 goto out;
482 }
483 brelse(gdb);
484 }
485
486 /* Zero out all of the reserved backup group descriptor
487 * table blocks
488 */
489 if (ext4_bg_has_super(sb, group)) {
490 err = sb_issue_zeroout(sb, gdblocks + start + 1,
491 reserved_gdb, GFP_NOFS);
492 if (err)
493 goto out;
494 }
495
496 /* Initialize group tables of the grop @group */
497 if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED))
498 goto handle_bb;
499
500 /* Zero out all of the inode table blocks */
501 block = group_data[i].inode_table;
502 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n",
503 block, sbi->s_itb_per_group);
504 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group,
505 GFP_NOFS);
506 if (err)
507 goto out;
508
509handle_bb:
510 if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT)
511 goto handle_ib;
512
513 /* Initialize block bitmap of the @group */
514 block = group_data[i].block_bitmap;
515 err = extend_or_restart_transaction(handle, 1);
516 if (err)
517 goto out;
518
519 bh = bclean(handle, sb, block);
520 if (IS_ERR(bh)) {
521 err = PTR_ERR(bh);
522 goto out;
523 }
524 if (ext4_bg_has_super(sb, group)) {
525 ext4_debug("mark backup superblock %#04llx (+0)\n",
526 start);
527 ext4_set_bits(bh->b_data, 0, gdblocks + reserved_gdb +
528 1);
529 }
530 ext4_mark_bitmap_end(group_data[i].blocks_count,
531 sb->s_blocksize * 8, bh->b_data);
532 err = ext4_handle_dirty_metadata(handle, NULL, bh);
533 if (err)
534 goto out;
535 brelse(bh);
536
537handle_ib:
538 if (bg_flags[i] & EXT4_BG_INODE_UNINIT)
539 continue;
540
541 /* Initialize inode bitmap of the @group */
542 block = group_data[i].inode_bitmap;
543 err = extend_or_restart_transaction(handle, 1);
544 if (err)
545 goto out;
546 /* Mark unused entries in inode bitmap used */
547 bh = bclean(handle, sb, block);
548 if (IS_ERR(bh)) {
549 err = PTR_ERR(bh);
550 goto out;
551 }
552
553 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
554 sb->s_blocksize * 8, bh->b_data);
555 err = ext4_handle_dirty_metadata(handle, NULL, bh);
556 if (err)
557 goto out;
558 brelse(bh);
559 }
560 bh = NULL;
561
562 /* Mark group tables in block bitmap */
563 for (j = 0; j < GROUP_TABLE_COUNT; j++) {
564 count = group_table_count[j];
565 start = (&group_data[0].block_bitmap)[j];
566 block = start;
567 for (i = 1; i < flex_gd->count; i++) {
568 block += group_table_count[j];
569 if (block == (&group_data[i].block_bitmap)[j]) {
570 count += group_table_count[j];
571 continue;
572 }
573 err = set_flexbg_block_bitmap(sb, handle,
574 flex_gd, start, count);
575 if (err)
576 goto out;
577 count = group_table_count[j];
578 start = group_data[i].block_bitmap;
579 block = start;
580 }
581
582 if (count) {
583 err = set_flexbg_block_bitmap(sb, handle,
584 flex_gd, start, count);
585 if (err)
586 goto out;
587 }
588 }
589
590out:
591 brelse(bh);
592 err2 = ext4_journal_stop(handle);
593 if (err2 && !err)
594 err = err2;
595
596 return err;
597}
598
599/*
600 * Iterate through the groups which hold BACKUP superblock/GDT copies in an
601 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
602 * calling this for the first time. In a sparse filesystem it will be the
603 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
604 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
605 */
606static unsigned ext4_list_backups(struct super_block *sb, unsigned *three,
607 unsigned *five, unsigned *seven)
608{
609 unsigned *min = three;
610 int mult = 3;
611 unsigned ret;
612
613 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
614 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
615 ret = *min;
616 *min += 1;
617 return ret;
618 }
619
620 if (*five < *min) {
621 min = five;
622 mult = 5;
623 }
624 if (*seven < *min) {
625 min = seven;
626 mult = 7;
627 }
628
629 ret = *min;
630 *min *= mult;
631
632 return ret;
633}
634
635/*
636 * Check that all of the backup GDT blocks are held in the primary GDT block.
637 * It is assumed that they are stored in group order. Returns the number of
638 * groups in current filesystem that have BACKUPS, or -ve error code.
639 */
640static int verify_reserved_gdb(struct super_block *sb,
641 ext4_group_t end,
642 struct buffer_head *primary)
643{
644 const ext4_fsblk_t blk = primary->b_blocknr;
645 unsigned three = 1;
646 unsigned five = 5;
647 unsigned seven = 7;
648 unsigned grp;
649 __le32 *p = (__le32 *)primary->b_data;
650 int gdbackups = 0;
651
652 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) {
653 if (le32_to_cpu(*p++) !=
654 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){
655 ext4_warning(sb, "reserved GDT %llu"
656 " missing grp %d (%llu)",
657 blk, grp,
658 grp *
659 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
660 blk);
661 return -EINVAL;
662 }
663 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb))
664 return -EFBIG;
665 }
666
667 return gdbackups;
668}
669
670/*
671 * Called when we need to bring a reserved group descriptor table block into
672 * use from the resize inode. The primary copy of the new GDT block currently
673 * is an indirect block (under the double indirect block in the resize inode).
674 * The new backup GDT blocks will be stored as leaf blocks in this indirect
675 * block, in group order. Even though we know all the block numbers we need,
676 * we check to ensure that the resize inode has actually reserved these blocks.
677 *
678 * Don't need to update the block bitmaps because the blocks are still in use.
679 *
680 * We get all of the error cases out of the way, so that we are sure to not
681 * fail once we start modifying the data on disk, because JBD has no rollback.
682 */
683static int add_new_gdb(handle_t *handle, struct inode *inode,
684 ext4_group_t group)
685{
686 struct super_block *sb = inode->i_sb;
687 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
688 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
689 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
690 struct buffer_head **o_group_desc, **n_group_desc;
691 struct buffer_head *dind;
692 struct buffer_head *gdb_bh;
693 int gdbackups;
694 struct ext4_iloc iloc;
695 __le32 *data;
696 int err;
697
698 if (test_opt(sb, DEBUG))
699 printk(KERN_DEBUG
700 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
701 gdb_num);
702
703 /*
704 * If we are not using the primary superblock/GDT copy don't resize,
705 * because the user tools have no way of handling this. Probably a
706 * bad time to do it anyways.
707 */
708 if (EXT4_SB(sb)->s_sbh->b_blocknr !=
709 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
710 ext4_warning(sb, "won't resize using backup superblock at %llu",
711 (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
712 return -EPERM;
713 }
714
715 gdb_bh = sb_bread(sb, gdblock);
716 if (!gdb_bh)
717 return -EIO;
718
719 gdbackups = verify_reserved_gdb(sb, group, gdb_bh);
720 if (gdbackups < 0) {
721 err = gdbackups;
722 goto exit_bh;
723 }
724
725 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
726 dind = sb_bread(sb, le32_to_cpu(*data));
727 if (!dind) {
728 err = -EIO;
729 goto exit_bh;
730 }
731
732 data = (__le32 *)dind->b_data;
733 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) {
734 ext4_warning(sb, "new group %u GDT block %llu not reserved",
735 group, gdblock);
736 err = -EINVAL;
737 goto exit_dind;
738 }
739
740 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
741 if (unlikely(err))
742 goto exit_dind;
743
744 err = ext4_journal_get_write_access(handle, gdb_bh);
745 if (unlikely(err))
746 goto exit_sbh;
747
748 err = ext4_journal_get_write_access(handle, dind);
749 if (unlikely(err))
750 ext4_std_error(sb, err);
751
752 /* ext4_reserve_inode_write() gets a reference on the iloc */
753 err = ext4_reserve_inode_write(handle, inode, &iloc);
754 if (unlikely(err))
755 goto exit_dindj;
756
757 n_group_desc = ext4_kvmalloc((gdb_num + 1) *
758 sizeof(struct buffer_head *),
759 GFP_NOFS);
760 if (!n_group_desc) {
761 err = -ENOMEM;
762 ext4_warning(sb, "not enough memory for %lu groups",
763 gdb_num + 1);
764 goto exit_inode;
765 }
766
767 /*
768 * Finally, we have all of the possible failures behind us...
769 *
770 * Remove new GDT block from inode double-indirect block and clear out
771 * the new GDT block for use (which also "frees" the backup GDT blocks
772 * from the reserved inode). We don't need to change the bitmaps for
773 * these blocks, because they are marked as in-use from being in the
774 * reserved inode, and will become GDT blocks (primary and backup).
775 */
776 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0;
777 err = ext4_handle_dirty_metadata(handle, NULL, dind);
778 if (unlikely(err)) {
779 ext4_std_error(sb, err);
780 goto exit_inode;
781 }
782 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9;
783 ext4_mark_iloc_dirty(handle, inode, &iloc);
784 memset(gdb_bh->b_data, 0, sb->s_blocksize);
785 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
786 if (unlikely(err)) {
787 ext4_std_error(sb, err);
788 goto exit_inode;
789 }
790 brelse(dind);
791
792 o_group_desc = EXT4_SB(sb)->s_group_desc;
793 memcpy(n_group_desc, o_group_desc,
794 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
795 n_group_desc[gdb_num] = gdb_bh;
796 EXT4_SB(sb)->s_group_desc = n_group_desc;
797 EXT4_SB(sb)->s_gdb_count++;
798 ext4_kvfree(o_group_desc);
799
800 le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
801 err = ext4_handle_dirty_super_now(handle, sb);
802 if (err)
803 ext4_std_error(sb, err);
804
805 return err;
806
807exit_inode:
808 ext4_kvfree(n_group_desc);
809 /* ext4_handle_release_buffer(handle, iloc.bh); */
810 brelse(iloc.bh);
811exit_dindj:
812 /* ext4_handle_release_buffer(handle, dind); */
813exit_sbh:
814 /* ext4_handle_release_buffer(handle, EXT4_SB(sb)->s_sbh); */
815exit_dind:
816 brelse(dind);
817exit_bh:
818 brelse(gdb_bh);
819
820 ext4_debug("leaving with error %d\n", err);
821 return err;
822}
823
824/*
825 * Called when we are adding a new group which has a backup copy of each of
826 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
827 * We need to add these reserved backup GDT blocks to the resize inode, so
828 * that they are kept for future resizing and not allocated to files.
829 *
830 * Each reserved backup GDT block will go into a different indirect block.
831 * The indirect blocks are actually the primary reserved GDT blocks,
832 * so we know in advance what their block numbers are. We only get the
833 * double-indirect block to verify it is pointing to the primary reserved
834 * GDT blocks so we don't overwrite a data block by accident. The reserved
835 * backup GDT blocks are stored in their reserved primary GDT block.
836 */
837static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
838 ext4_group_t group)
839{
840 struct super_block *sb = inode->i_sb;
841 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
842 struct buffer_head **primary;
843 struct buffer_head *dind;
844 struct ext4_iloc iloc;
845 ext4_fsblk_t blk;
846 __le32 *data, *end;
847 int gdbackups = 0;
848 int res, i;
849 int err;
850
851 primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS);
852 if (!primary)
853 return -ENOMEM;
854
855 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
856 dind = sb_bread(sb, le32_to_cpu(*data));
857 if (!dind) {
858 err = -EIO;
859 goto exit_free;
860 }
861
862 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count;
863 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count %
864 EXT4_ADDR_PER_BLOCK(sb));
865 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb);
866
867 /* Get each reserved primary GDT block and verify it holds backups */
868 for (res = 0; res < reserved_gdb; res++, blk++) {
869 if (le32_to_cpu(*data) != blk) {
870 ext4_warning(sb, "reserved block %llu"
871 " not at offset %ld",
872 blk,
873 (long)(data - (__le32 *)dind->b_data));
874 err = -EINVAL;
875 goto exit_bh;
876 }
877 primary[res] = sb_bread(sb, blk);
878 if (!primary[res]) {
879 err = -EIO;
880 goto exit_bh;
881 }
882 gdbackups = verify_reserved_gdb(sb, group, primary[res]);
883 if (gdbackups < 0) {
884 brelse(primary[res]);
885 err = gdbackups;
886 goto exit_bh;
887 }
888 if (++data >= end)
889 data = (__le32 *)dind->b_data;
890 }
891
892 for (i = 0; i < reserved_gdb; i++) {
893 if ((err = ext4_journal_get_write_access(handle, primary[i]))) {
894 /*
895 int j;
896 for (j = 0; j < i; j++)
897 ext4_handle_release_buffer(handle, primary[j]);
898 */
899 goto exit_bh;
900 }
901 }
902
903 if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
904 goto exit_bh;
905
906 /*
907 * Finally we can add each of the reserved backup GDT blocks from
908 * the new group to its reserved primary GDT block.
909 */
910 blk = group * EXT4_BLOCKS_PER_GROUP(sb);
911 for (i = 0; i < reserved_gdb; i++) {
912 int err2;
913 data = (__le32 *)primary[i]->b_data;
914 /* printk("reserving backup %lu[%u] = %lu\n",
915 primary[i]->b_blocknr, gdbackups,
916 blk + primary[i]->b_blocknr); */
917 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
918 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]);
919 if (!err)
920 err = err2;
921 }
922 inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9;
923 ext4_mark_iloc_dirty(handle, inode, &iloc);
924
925exit_bh:
926 while (--res >= 0)
927 brelse(primary[res]);
928 brelse(dind);
929
930exit_free:
931 kfree(primary);
932
933 return err;
934}
935
936/*
937 * Update the backup copies of the ext4 metadata. These don't need to be part
938 * of the main resize transaction, because e2fsck will re-write them if there
939 * is a problem (basically only OOM will cause a problem). However, we
940 * _should_ update the backups if possible, in case the primary gets trashed
941 * for some reason and we need to run e2fsck from a backup superblock. The
942 * important part is that the new block and inode counts are in the backup
943 * superblocks, and the location of the new group metadata in the GDT backups.
944 *
945 * We do not need take the s_resize_lock for this, because these
946 * blocks are not otherwise touched by the filesystem code when it is
947 * mounted. We don't need to worry about last changing from
948 * sbi->s_groups_count, because the worst that can happen is that we
949 * do not copy the full number of backups at this time. The resize
950 * which changed s_groups_count will backup again.
951 */
952static void update_backups(struct super_block *sb,
953 int blk_off, char *data, int size)
954{
955 struct ext4_sb_info *sbi = EXT4_SB(sb);
956 const ext4_group_t last = sbi->s_groups_count;
957 const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
958 unsigned three = 1;
959 unsigned five = 5;
960 unsigned seven = 7;
961 ext4_group_t group;
962 int rest = sb->s_blocksize - size;
963 handle_t *handle;
964 int err = 0, err2;
965
966 handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
967 if (IS_ERR(handle)) {
968 group = 1;
969 err = PTR_ERR(handle);
970 goto exit_err;
971 }
972
973 ext4_superblock_csum_set(sb, (struct ext4_super_block *)data);
974
975 while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) {
976 struct buffer_head *bh;
977
978 /* Out of journal space, and can't get more - abort - so sad */
979 if (ext4_handle_valid(handle) &&
980 handle->h_buffer_credits == 0 &&
981 ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA) &&
982 (err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
983 break;
984
985 bh = sb_getblk(sb, group * bpg + blk_off);
986 if (!bh) {
987 err = -EIO;
988 break;
989 }
990 ext4_debug("update metadata backup %#04lx\n",
991 (unsigned long)bh->b_blocknr);
992 if ((err = ext4_journal_get_write_access(handle, bh)))
993 break;
994 lock_buffer(bh);
995 memcpy(bh->b_data, data, size);
996 if (rest)
997 memset(bh->b_data + size, 0, rest);
998 set_buffer_uptodate(bh);
999 unlock_buffer(bh);
1000 err = ext4_handle_dirty_metadata(handle, NULL, bh);
1001 if (unlikely(err))
1002 ext4_std_error(sb, err);
1003 brelse(bh);
1004 }
1005 if ((err2 = ext4_journal_stop(handle)) && !err)
1006 err = err2;
1007
1008 /*
1009 * Ugh! Need to have e2fsck write the backup copies. It is too
1010 * late to revert the resize, we shouldn't fail just because of
1011 * the backup copies (they are only needed in case of corruption).
1012 *
1013 * However, if we got here we have a journal problem too, so we
1014 * can't really start a transaction to mark the superblock.
1015 * Chicken out and just set the flag on the hope it will be written
1016 * to disk, and if not - we will simply wait until next fsck.
1017 */
1018exit_err:
1019 if (err) {
1020 ext4_warning(sb, "can't update backup for group %u (err %d), "
1021 "forcing fsck on next reboot", group, err);
1022 sbi->s_mount_state &= ~EXT4_VALID_FS;
1023 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1024 mark_buffer_dirty(sbi->s_sbh);
1025 }
1026}
1027
1028/*
1029 * ext4_add_new_descs() adds @count group descriptor of groups
1030 * starting at @group
1031 *
1032 * @handle: journal handle
1033 * @sb: super block
1034 * @group: the group no. of the first group desc to be added
1035 * @resize_inode: the resize inode
1036 * @count: number of group descriptors to be added
1037 */
1038static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
1039 ext4_group_t group, struct inode *resize_inode,
1040 ext4_group_t count)
1041{
1042 struct ext4_sb_info *sbi = EXT4_SB(sb);
1043 struct ext4_super_block *es = sbi->s_es;
1044 struct buffer_head *gdb_bh;
1045 int i, gdb_off, gdb_num, err = 0;
1046
1047 for (i = 0; i < count; i++, group++) {
1048 int reserved_gdb = ext4_bg_has_super(sb, group) ?
1049 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
1050
1051 gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
1052 gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1053
1054 /*
1055 * We will only either add reserved group blocks to a backup group
1056 * or remove reserved blocks for the first group in a new group block.
1057 * Doing both would be mean more complex code, and sane people don't
1058 * use non-sparse filesystems anymore. This is already checked above.
1059 */
1060 if (gdb_off) {
1061 gdb_bh = sbi->s_group_desc[gdb_num];
1062 err = ext4_journal_get_write_access(handle, gdb_bh);
1063
1064 if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group))
1065 err = reserve_backup_gdb(handle, resize_inode, group);
1066 } else
1067 err = add_new_gdb(handle, resize_inode, group);
1068 if (err)
1069 break;
1070 }
1071 return err;
1072}
1073
1074static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block)
1075{
1076 struct buffer_head *bh = sb_getblk(sb, block);
1077 if (!bh)
1078 return NULL;
1079
1080 if (bitmap_uptodate(bh))
1081 return bh;
1082
1083 lock_buffer(bh);
1084 if (bh_submit_read(bh) < 0) {
1085 unlock_buffer(bh);
1086 brelse(bh);
1087 return NULL;
1088 }
1089 unlock_buffer(bh);
1090
1091 return bh;
1092}
1093
1094static int ext4_set_bitmap_checksums(struct super_block *sb,
1095 ext4_group_t group,
1096 struct ext4_group_desc *gdp,
1097 struct ext4_new_group_data *group_data)
1098{
1099 struct buffer_head *bh;
1100
1101 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
1102 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1103 return 0;
1104
1105 bh = ext4_get_bitmap(sb, group_data->inode_bitmap);
1106 if (!bh)
1107 return -EIO;
1108 ext4_inode_bitmap_csum_set(sb, group, gdp, bh,
1109 EXT4_INODES_PER_GROUP(sb) / 8);
1110 brelse(bh);
1111
1112 bh = ext4_get_bitmap(sb, group_data->block_bitmap);
1113 if (!bh)
1114 return -EIO;
1115 ext4_block_bitmap_csum_set(sb, group, gdp, bh,
1116 EXT4_BLOCKS_PER_GROUP(sb) / 8);
1117 brelse(bh);
1118
1119 return 0;
1120}
1121
1122/*
1123 * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg
1124 */
1125static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb,
1126 struct ext4_new_flex_group_data *flex_gd)
1127{
1128 struct ext4_new_group_data *group_data = flex_gd->groups;
1129 struct ext4_group_desc *gdp;
1130 struct ext4_sb_info *sbi = EXT4_SB(sb);
1131 struct buffer_head *gdb_bh;
1132 ext4_group_t group;
1133 __u16 *bg_flags = flex_gd->bg_flags;
1134 int i, gdb_off, gdb_num, err = 0;
1135
1136
1137 for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) {
1138 group = group_data->group;
1139
1140 gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
1141 gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1142
1143 /*
1144 * get_write_access() has been called on gdb_bh by ext4_add_new_desc().
1145 */
1146 gdb_bh = sbi->s_group_desc[gdb_num];
1147 /* Update group descriptor block for new group */
1148 gdp = (struct ext4_group_desc *)(gdb_bh->b_data +
1149 gdb_off * EXT4_DESC_SIZE(sb));
1150
1151 memset(gdp, 0, EXT4_DESC_SIZE(sb));
1152 ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap);
1153 ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap);
1154 err = ext4_set_bitmap_checksums(sb, group, gdp, group_data);
1155 if (err) {
1156 ext4_std_error(sb, err);
1157 break;
1158 }
1159
1160 ext4_inode_table_set(sb, gdp, group_data->inode_table);
1161 ext4_free_group_clusters_set(sb, gdp,
1162 EXT4_B2C(sbi, group_data->free_blocks_count));
1163 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
1164 gdp->bg_flags = cpu_to_le16(*bg_flags);
1165 ext4_group_desc_csum_set(sb, group, gdp);
1166
1167 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
1168 if (unlikely(err)) {
1169 ext4_std_error(sb, err);
1170 break;
1171 }
1172
1173 /*
1174 * We can allocate memory for mb_alloc based on the new group
1175 * descriptor
1176 */
1177 err = ext4_mb_add_groupinfo(sb, group, gdp);
1178 if (err)
1179 break;
1180 }
1181 return err;
1182}
1183
1184/*
1185 * ext4_update_super() updates the super block so that the newly added
1186 * groups can be seen by the filesystem.
1187 *
1188 * @sb: super block
1189 * @flex_gd: new added groups
1190 */
1191static void ext4_update_super(struct super_block *sb,
1192 struct ext4_new_flex_group_data *flex_gd)
1193{
1194 ext4_fsblk_t blocks_count = 0;
1195 ext4_fsblk_t free_blocks = 0;
1196 ext4_fsblk_t reserved_blocks = 0;
1197 struct ext4_new_group_data *group_data = flex_gd->groups;
1198 struct ext4_sb_info *sbi = EXT4_SB(sb);
1199 struct ext4_super_block *es = sbi->s_es;
1200 int i, ret;
1201
1202 BUG_ON(flex_gd->count == 0 || group_data == NULL);
1203 /*
1204 * Make the new blocks and inodes valid next. We do this before
1205 * increasing the group count so that once the group is enabled,
1206 * all of its blocks and inodes are already valid.
1207 *
1208 * We always allocate group-by-group, then block-by-block or
1209 * inode-by-inode within a group, so enabling these
1210 * blocks/inodes before the group is live won't actually let us
1211 * allocate the new space yet.
1212 */
1213 for (i = 0; i < flex_gd->count; i++) {
1214 blocks_count += group_data[i].blocks_count;
1215 free_blocks += group_data[i].free_blocks_count;
1216 }
1217
1218 reserved_blocks = ext4_r_blocks_count(es) * 100;
1219 do_div(reserved_blocks, ext4_blocks_count(es));
1220 reserved_blocks *= blocks_count;
1221 do_div(reserved_blocks, 100);
1222
1223 ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count);
1224 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks);
1225 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) *
1226 flex_gd->count);
1227 le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) *
1228 flex_gd->count);
1229
1230 /*
1231 * We need to protect s_groups_count against other CPUs seeing
1232 * inconsistent state in the superblock.
1233 *
1234 * The precise rules we use are:
1235 *
1236 * * Writers must perform a smp_wmb() after updating all
1237 * dependent data and before modifying the groups count
1238 *
1239 * * Readers must perform an smp_rmb() after reading the groups
1240 * count and before reading any dependent data.
1241 *
1242 * NB. These rules can be relaxed when checking the group count
1243 * while freeing data, as we can only allocate from a block
1244 * group after serialising against the group count, and we can
1245 * only then free after serialising in turn against that
1246 * allocation.
1247 */
1248 smp_wmb();
1249
1250 /* Update the global fs size fields */
1251 sbi->s_groups_count += flex_gd->count;
1252
1253 /* Update the reserved block counts only once the new group is
1254 * active. */
1255 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) +
1256 reserved_blocks);
1257
1258 /* Update the free space counts */
1259 percpu_counter_add(&sbi->s_freeclusters_counter,
1260 EXT4_B2C(sbi, free_blocks));
1261 percpu_counter_add(&sbi->s_freeinodes_counter,
1262 EXT4_INODES_PER_GROUP(sb) * flex_gd->count);
1263
1264 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
1265 EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
1266 sbi->s_log_groups_per_flex) {
1267 ext4_group_t flex_group;
1268 flex_group = ext4_flex_group(sbi, group_data[0].group);
1269 atomic_add(EXT4_B2C(sbi, free_blocks),
1270 &sbi->s_flex_groups[flex_group].free_clusters);
1271 atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count,
1272 &sbi->s_flex_groups[flex_group].free_inodes);
1273 }
1274
1275 /*
1276 * Update the fs overhead information
1277 */
1278 ext4_calculate_overhead(sb);
1279
1280 if (test_opt(sb, DEBUG))
1281 printk(KERN_DEBUG "EXT4-fs: added group %u:"
1282 "%llu blocks(%llu free %llu reserved)\n", flex_gd->count,
1283 blocks_count, free_blocks, reserved_blocks);
1284}
1285
1286/* Add a flex group to an fs. Ensure we handle all possible error conditions
1287 * _before_ we start modifying the filesystem, because we cannot abort the
1288 * transaction and not have it write the data to disk.
1289 */
1290static int ext4_flex_group_add(struct super_block *sb,
1291 struct inode *resize_inode,
1292 struct ext4_new_flex_group_data *flex_gd)
1293{
1294 struct ext4_sb_info *sbi = EXT4_SB(sb);
1295 struct ext4_super_block *es = sbi->s_es;
1296 ext4_fsblk_t o_blocks_count;
1297 ext4_grpblk_t last;
1298 ext4_group_t group;
1299 handle_t *handle;
1300 unsigned reserved_gdb;
1301 int err = 0, err2 = 0, credit;
1302
1303 BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags);
1304
1305 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
1306 o_blocks_count = ext4_blocks_count(es);
1307 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1308 BUG_ON(last);
1309
1310 err = setup_new_flex_group_blocks(sb, flex_gd);
1311 if (err)
1312 goto exit;
1313 /*
1314 * We will always be modifying at least the superblock and GDT
1315 * block. If we are adding a group past the last current GDT block,
1316 * we will also modify the inode and the dindirect block. If we
1317 * are adding a group with superblock/GDT backups we will also
1318 * modify each of the reserved GDT dindirect blocks.
1319 */
1320 credit = flex_gd->count * 4 + reserved_gdb;
1321 handle = ext4_journal_start_sb(sb, credit);
1322 if (IS_ERR(handle)) {
1323 err = PTR_ERR(handle);
1324 goto exit;
1325 }
1326
1327 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
1328 if (err)
1329 goto exit_journal;
1330
1331 group = flex_gd->groups[0].group;
1332 BUG_ON(group != EXT4_SB(sb)->s_groups_count);
1333 err = ext4_add_new_descs(handle, sb, group,
1334 resize_inode, flex_gd->count);
1335 if (err)
1336 goto exit_journal;
1337
1338 err = ext4_setup_new_descs(handle, sb, flex_gd);
1339 if (err)
1340 goto exit_journal;
1341
1342 ext4_update_super(sb, flex_gd);
1343
1344 err = ext4_handle_dirty_super(handle, sb);
1345
1346exit_journal:
1347 err2 = ext4_journal_stop(handle);
1348 if (!err)
1349 err = err2;
1350
1351 if (!err) {
1352 int i;
1353 update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
1354 sizeof(struct ext4_super_block));
1355 for (i = 0; i < flex_gd->count; i++, group++) {
1356 struct buffer_head *gdb_bh;
1357 int gdb_num;
1358 gdb_num = group / EXT4_BLOCKS_PER_GROUP(sb);
1359 gdb_bh = sbi->s_group_desc[gdb_num];
1360 update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data,
1361 gdb_bh->b_size);
1362 }
1363 }
1364exit:
1365 return err;
1366}
1367
1368static int ext4_setup_next_flex_gd(struct super_block *sb,
1369 struct ext4_new_flex_group_data *flex_gd,
1370 ext4_fsblk_t n_blocks_count,
1371 unsigned long flexbg_size)
1372{
1373 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1374 struct ext4_new_group_data *group_data = flex_gd->groups;
1375 ext4_fsblk_t o_blocks_count;
1376 ext4_group_t n_group;
1377 ext4_group_t group;
1378 ext4_group_t last_group;
1379 ext4_grpblk_t last;
1380 ext4_grpblk_t blocks_per_group;
1381 unsigned long i;
1382
1383 blocks_per_group = EXT4_BLOCKS_PER_GROUP(sb);
1384
1385 o_blocks_count = ext4_blocks_count(es);
1386
1387 if (o_blocks_count == n_blocks_count)
1388 return 0;
1389
1390 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1391 BUG_ON(last);
1392 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last);
1393
1394 last_group = group | (flexbg_size - 1);
1395 if (last_group > n_group)
1396 last_group = n_group;
1397
1398 flex_gd->count = last_group - group + 1;
1399
1400 for (i = 0; i < flex_gd->count; i++) {
1401 int overhead;
1402
1403 group_data[i].group = group + i;
1404 group_data[i].blocks_count = blocks_per_group;
1405 overhead = ext4_bg_has_super(sb, group + i) ?
1406 (1 + ext4_bg_num_gdb(sb, group + i) +
1407 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
1408 group_data[i].free_blocks_count = blocks_per_group - overhead;
1409 if (ext4_has_group_desc_csum(sb))
1410 flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT |
1411 EXT4_BG_INODE_UNINIT;
1412 else
1413 flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED;
1414 }
1415
1416 if (last_group == n_group && ext4_has_group_desc_csum(sb))
1417 /* We need to initialize block bitmap of last group. */
1418 flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT;
1419
1420 if ((last_group == n_group) && (last != blocks_per_group - 1)) {
1421 group_data[i - 1].blocks_count = last + 1;
1422 group_data[i - 1].free_blocks_count -= blocks_per_group-
1423 last - 1;
1424 }
1425
1426 return 1;
1427}
1428
1429/* Add group descriptor data to an existing or new group descriptor block.
1430 * Ensure we handle all possible error conditions _before_ we start modifying
1431 * the filesystem, because we cannot abort the transaction and not have it
1432 * write the data to disk.
1433 *
1434 * If we are on a GDT block boundary, we need to get the reserved GDT block.
1435 * Otherwise, we may need to add backup GDT blocks for a sparse group.
1436 *
1437 * We only need to hold the superblock lock while we are actually adding
1438 * in the new group's counts to the superblock. Prior to that we have
1439 * not really "added" the group at all. We re-check that we are still
1440 * adding in the last group in case things have changed since verifying.
1441 */
1442int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
1443{
1444 struct ext4_new_flex_group_data flex_gd;
1445 struct ext4_sb_info *sbi = EXT4_SB(sb);
1446 struct ext4_super_block *es = sbi->s_es;
1447 int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
1448 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
1449 struct inode *inode = NULL;
1450 int gdb_off, gdb_num;
1451 int err;
1452 __u16 bg_flags = 0;
1453
1454 gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb);
1455 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb);
1456
1457 if (gdb_off == 0 && !EXT4_HAS_RO_COMPAT_FEATURE(sb,
1458 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
1459 ext4_warning(sb, "Can't resize non-sparse filesystem further");
1460 return -EPERM;
1461 }
1462
1463 if (ext4_blocks_count(es) + input->blocks_count <
1464 ext4_blocks_count(es)) {
1465 ext4_warning(sb, "blocks_count overflow");
1466 return -EINVAL;
1467 }
1468
1469 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) <
1470 le32_to_cpu(es->s_inodes_count)) {
1471 ext4_warning(sb, "inodes_count overflow");
1472 return -EINVAL;
1473 }
1474
1475 if (reserved_gdb || gdb_off == 0) {
1476 if (!EXT4_HAS_COMPAT_FEATURE(sb,
1477 EXT4_FEATURE_COMPAT_RESIZE_INODE)
1478 || !le16_to_cpu(es->s_reserved_gdt_blocks)) {
1479 ext4_warning(sb,
1480 "No reserved GDT blocks, can't resize");
1481 return -EPERM;
1482 }
1483 inode = ext4_iget(sb, EXT4_RESIZE_INO);
1484 if (IS_ERR(inode)) {
1485 ext4_warning(sb, "Error opening resize inode");
1486 return PTR_ERR(inode);
1487 }
1488 }
1489
1490
1491 err = verify_group_input(sb, input);
1492 if (err)
1493 goto out;
1494
1495 flex_gd.count = 1;
1496 flex_gd.groups = input;
1497 flex_gd.bg_flags = &bg_flags;
1498 err = ext4_flex_group_add(sb, inode, &flex_gd);
1499out:
1500 iput(inode);
1501 return err;
1502} /* ext4_group_add */
1503
1504/*
1505 * extend a group without checking assuming that checking has been done.
1506 */
1507static int ext4_group_extend_no_check(struct super_block *sb,
1508 ext4_fsblk_t o_blocks_count, ext4_grpblk_t add)
1509{
1510 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1511 handle_t *handle;
1512 int err = 0, err2;
1513
1514 /* We will update the superblock, one block bitmap, and
1515 * one group descriptor via ext4_group_add_blocks().
1516 */
1517 handle = ext4_journal_start_sb(sb, 3);
1518 if (IS_ERR(handle)) {
1519 err = PTR_ERR(handle);
1520 ext4_warning(sb, "error %d on journal start", err);
1521 return err;
1522 }
1523
1524 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
1525 if (err) {
1526 ext4_warning(sb, "error %d on journal write access", err);
1527 goto errout;
1528 }
1529
1530 ext4_blocks_count_set(es, o_blocks_count + add);
1531 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add);
1532 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
1533 o_blocks_count + add);
1534 /* We add the blocks to the bitmap and set the group need init bit */
1535 err = ext4_group_add_blocks(handle, sb, o_blocks_count, add);
1536 if (err)
1537 goto errout;
1538 ext4_handle_dirty_super(handle, sb);
1539 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
1540 o_blocks_count + add);
1541errout:
1542 err2 = ext4_journal_stop(handle);
1543 if (err2 && !err)
1544 err = err2;
1545
1546 if (!err) {
1547 if (test_opt(sb, DEBUG))
1548 printk(KERN_DEBUG "EXT4-fs: extended group to %llu "
1549 "blocks\n", ext4_blocks_count(es));
1550 update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, (char *)es,
1551 sizeof(struct ext4_super_block));
1552 }
1553 return err;
1554}
1555
1556/*
1557 * Extend the filesystem to the new number of blocks specified. This entry
1558 * point is only used to extend the current filesystem to the end of the last
1559 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>"
1560 * for emergencies (because it has no dependencies on reserved blocks).
1561 *
1562 * If we _really_ wanted, we could use default values to call ext4_group_add()
1563 * allow the "remount" trick to work for arbitrary resizing, assuming enough
1564 * GDT blocks are reserved to grow to the desired size.
1565 */
1566int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
1567 ext4_fsblk_t n_blocks_count)
1568{
1569 ext4_fsblk_t o_blocks_count;
1570 ext4_grpblk_t last;
1571 ext4_grpblk_t add;
1572 struct buffer_head *bh;
1573 int err;
1574 ext4_group_t group;
1575
1576 o_blocks_count = ext4_blocks_count(es);
1577
1578 if (test_opt(sb, DEBUG))
1579 ext4_msg(sb, KERN_DEBUG,
1580 "extending last group from %llu to %llu blocks",
1581 o_blocks_count, n_blocks_count);
1582
1583 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
1584 return 0;
1585
1586 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1587 ext4_msg(sb, KERN_ERR,
1588 "filesystem too large to resize to %llu blocks safely",
1589 n_blocks_count);
1590 if (sizeof(sector_t) < 8)
1591 ext4_warning(sb, "CONFIG_LBDAF not enabled");
1592 return -EINVAL;
1593 }
1594
1595 if (n_blocks_count < o_blocks_count) {
1596 ext4_warning(sb, "can't shrink FS - resize aborted");
1597 return -EINVAL;
1598 }
1599
1600 /* Handle the remaining blocks in the last group only. */
1601 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1602
1603 if (last == 0) {
1604 ext4_warning(sb, "need to use ext2online to resize further");
1605 return -EPERM;
1606 }
1607
1608 add = EXT4_BLOCKS_PER_GROUP(sb) - last;
1609
1610 if (o_blocks_count + add < o_blocks_count) {
1611 ext4_warning(sb, "blocks_count overflow");
1612 return -EINVAL;
1613 }
1614
1615 if (o_blocks_count + add > n_blocks_count)
1616 add = n_blocks_count - o_blocks_count;
1617
1618 if (o_blocks_count + add < n_blocks_count)
1619 ext4_warning(sb, "will only finish group (%llu blocks, %u new)",
1620 o_blocks_count + add, add);
1621
1622 /* See if the device is actually as big as what was requested */
1623 bh = sb_bread(sb, o_blocks_count + add - 1);
1624 if (!bh) {
1625 ext4_warning(sb, "can't read last block, resize aborted");
1626 return -ENOSPC;
1627 }
1628 brelse(bh);
1629
1630 err = ext4_group_extend_no_check(sb, o_blocks_count, add);
1631 return err;
1632} /* ext4_group_extend */
1633
1634/*
1635 * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count
1636 *
1637 * @sb: super block of the fs to be resized
1638 * @n_blocks_count: the number of blocks resides in the resized fs
1639 */
1640int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
1641{
1642 struct ext4_new_flex_group_data *flex_gd = NULL;
1643 struct ext4_sb_info *sbi = EXT4_SB(sb);
1644 struct ext4_super_block *es = sbi->s_es;
1645 struct buffer_head *bh;
1646 struct inode *resize_inode;
1647 ext4_fsblk_t o_blocks_count;
1648 ext4_group_t o_group;
1649 ext4_group_t n_group;
1650 ext4_grpblk_t offset, add;
1651 unsigned long n_desc_blocks;
1652 unsigned long o_desc_blocks;
1653 unsigned long desc_blocks;
1654 int err = 0, flexbg_size = 1;
1655
1656 o_blocks_count = ext4_blocks_count(es);
1657
1658 if (test_opt(sb, DEBUG))
1659 ext4_msg(sb, KERN_DEBUG, "resizing filesystem from %llu "
1660 "to %llu blocks", o_blocks_count, n_blocks_count);
1661
1662 if (n_blocks_count < o_blocks_count) {
1663 /* On-line shrinking not supported */
1664 ext4_warning(sb, "can't shrink FS - resize aborted");
1665 return -EINVAL;
1666 }
1667
1668 if (n_blocks_count == o_blocks_count)
1669 /* Nothing need to do */
1670 return 0;
1671
1672 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &offset);
1673 ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset);
1674
1675 n_desc_blocks = (n_group + EXT4_DESC_PER_BLOCK(sb)) /
1676 EXT4_DESC_PER_BLOCK(sb);
1677 o_desc_blocks = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
1678 EXT4_DESC_PER_BLOCK(sb);
1679 desc_blocks = n_desc_blocks - o_desc_blocks;
1680
1681 if (desc_blocks &&
1682 (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE) ||
1683 le16_to_cpu(es->s_reserved_gdt_blocks) < desc_blocks)) {
1684 ext4_warning(sb, "No reserved GDT blocks, can't resize");
1685 return -EPERM;
1686 }
1687
1688 resize_inode = ext4_iget(sb, EXT4_RESIZE_INO);
1689 if (IS_ERR(resize_inode)) {
1690 ext4_warning(sb, "Error opening resize inode");
1691 return PTR_ERR(resize_inode);
1692 }
1693
1694 /* See if the device is actually as big as what was requested */
1695 bh = sb_bread(sb, n_blocks_count - 1);
1696 if (!bh) {
1697 ext4_warning(sb, "can't read last block, resize aborted");
1698 return -ENOSPC;
1699 }
1700 brelse(bh);
1701
1702 /* extend the last group */
1703 if (n_group == o_group)
1704 add = n_blocks_count - o_blocks_count;
1705 else
1706 add = EXT4_BLOCKS_PER_GROUP(sb) - (offset + 1);
1707 if (add > 0) {
1708 err = ext4_group_extend_no_check(sb, o_blocks_count, add);
1709 if (err)
1710 goto out;
1711 }
1712
1713 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
1714 es->s_log_groups_per_flex)
1715 flexbg_size = 1 << es->s_log_groups_per_flex;
1716
1717 o_blocks_count = ext4_blocks_count(es);
1718 if (o_blocks_count == n_blocks_count)
1719 goto out;
1720
1721 flex_gd = alloc_flex_gd(flexbg_size);
1722 if (flex_gd == NULL) {
1723 err = -ENOMEM;
1724 goto out;
1725 }
1726
1727 /* Add flex groups. Note that a regular group is a
1728 * flex group with 1 group.
1729 */
1730 while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count,
1731 flexbg_size)) {
1732 ext4_alloc_group_tables(sb, flex_gd, flexbg_size);
1733 err = ext4_flex_group_add(sb, resize_inode, flex_gd);
1734 if (unlikely(err))
1735 break;
1736 }
1737
1738out:
1739 if (flex_gd)
1740 free_flex_gd(flex_gd);
1741
1742 iput(resize_inode);
1743 if (test_opt(sb, DEBUG))
1744 ext4_msg(sb, KERN_DEBUG, "resized filesystem from %llu "
1745 "upto %llu blocks", o_blocks_count, n_blocks_count);
1746 return err;
1747}
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#include <linux/errno.h>
14#include <linux/slab.h>
15#include <linux/jiffies.h>
16
17#include "ext4_jbd2.h"
18
19struct ext4_rcu_ptr {
20 struct rcu_head rcu;
21 void *ptr;
22};
23
24static void ext4_rcu_ptr_callback(struct rcu_head *head)
25{
26 struct ext4_rcu_ptr *ptr;
27
28 ptr = container_of(head, struct ext4_rcu_ptr, rcu);
29 kvfree(ptr->ptr);
30 kfree(ptr);
31}
32
33void ext4_kvfree_array_rcu(void *to_free)
34{
35 struct ext4_rcu_ptr *ptr = kzalloc(sizeof(*ptr), GFP_KERNEL);
36
37 if (ptr) {
38 ptr->ptr = to_free;
39 call_rcu(&ptr->rcu, ext4_rcu_ptr_callback);
40 return;
41 }
42 synchronize_rcu();
43 kvfree(to_free);
44}
45
46int ext4_resize_begin(struct super_block *sb)
47{
48 struct ext4_sb_info *sbi = EXT4_SB(sb);
49 int ret = 0;
50
51 if (!capable(CAP_SYS_RESOURCE))
52 return -EPERM;
53
54 /*
55 * If the reserved GDT blocks is non-zero, the resize_inode feature
56 * should always be set.
57 */
58 if (sbi->s_es->s_reserved_gdt_blocks &&
59 !ext4_has_feature_resize_inode(sb)) {
60 ext4_error(sb, "resize_inode disabled but reserved GDT blocks non-zero");
61 return -EFSCORRUPTED;
62 }
63
64 /*
65 * If we are not using the primary superblock/GDT copy don't resize,
66 * because the user tools have no way of handling this. Probably a
67 * bad time to do it anyways.
68 */
69 if (EXT4_B2C(sbi, sbi->s_sbh->b_blocknr) !=
70 le32_to_cpu(sbi->s_es->s_first_data_block)) {
71 ext4_warning(sb, "won't resize using backup superblock at %llu",
72 (unsigned long long)sbi->s_sbh->b_blocknr);
73 return -EPERM;
74 }
75
76 /*
77 * We are not allowed to do online-resizing on a filesystem mounted
78 * with error, because it can destroy the filesystem easily.
79 */
80 if (sbi->s_mount_state & EXT4_ERROR_FS) {
81 ext4_warning(sb, "There are errors in the filesystem, "
82 "so online resizing is not allowed");
83 return -EPERM;
84 }
85
86 if (ext4_has_feature_sparse_super2(sb)) {
87 ext4_msg(sb, KERN_ERR, "Online resizing not supported with sparse_super2");
88 return -EOPNOTSUPP;
89 }
90
91 if (test_and_set_bit_lock(EXT4_FLAGS_RESIZING,
92 &sbi->s_ext4_flags))
93 ret = -EBUSY;
94
95 return ret;
96}
97
98int ext4_resize_end(struct super_block *sb, bool update_backups)
99{
100 clear_bit_unlock(EXT4_FLAGS_RESIZING, &EXT4_SB(sb)->s_ext4_flags);
101 smp_mb__after_atomic();
102 if (update_backups)
103 return ext4_update_overhead(sb, true);
104 return 0;
105}
106
107static ext4_grpblk_t ext4_group_overhead_blocks(struct super_block *sb,
108 ext4_group_t group) {
109 ext4_grpblk_t overhead;
110 overhead = ext4_bg_num_gdb(sb, group);
111 if (ext4_bg_has_super(sb, group))
112 overhead += 1 +
113 le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
114 return overhead;
115}
116
117#define outside(b, first, last) ((b) < (first) || (b) >= (last))
118#define inside(b, first, last) ((b) >= (first) && (b) < (last))
119
120static int verify_group_input(struct super_block *sb,
121 struct ext4_new_group_data *input)
122{
123 struct ext4_sb_info *sbi = EXT4_SB(sb);
124 struct ext4_super_block *es = sbi->s_es;
125 ext4_fsblk_t start = ext4_blocks_count(es);
126 ext4_fsblk_t end = start + input->blocks_count;
127 ext4_group_t group = input->group;
128 ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
129 unsigned overhead;
130 ext4_fsblk_t metaend;
131 struct buffer_head *bh = NULL;
132 ext4_grpblk_t free_blocks_count, offset;
133 int err = -EINVAL;
134
135 if (group != sbi->s_groups_count) {
136 ext4_warning(sb, "Cannot add at group %u (only %u groups)",
137 input->group, sbi->s_groups_count);
138 return -EINVAL;
139 }
140
141 overhead = ext4_group_overhead_blocks(sb, group);
142 metaend = start + overhead;
143 free_blocks_count = input->blocks_count - 2 - overhead -
144 sbi->s_itb_per_group;
145 input->free_clusters_count = EXT4_B2C(sbi, free_blocks_count);
146
147 if (test_opt(sb, DEBUG))
148 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks "
149 "(%d free, %u reserved)\n",
150 ext4_bg_has_super(sb, input->group) ? "normal" :
151 "no-super", input->group, input->blocks_count,
152 free_blocks_count, input->reserved_blocks);
153
154 ext4_get_group_no_and_offset(sb, start, NULL, &offset);
155 if (offset != 0)
156 ext4_warning(sb, "Last group not full");
157 else if (input->reserved_blocks > input->blocks_count / 5)
158 ext4_warning(sb, "Reserved blocks too high (%u)",
159 input->reserved_blocks);
160 else if (free_blocks_count < 0)
161 ext4_warning(sb, "Bad blocks count %u",
162 input->blocks_count);
163 else if (IS_ERR(bh = ext4_sb_bread(sb, end - 1, 0))) {
164 err = PTR_ERR(bh);
165 bh = NULL;
166 ext4_warning(sb, "Cannot read last block (%llu)",
167 end - 1);
168 } else if (outside(input->block_bitmap, start, end))
169 ext4_warning(sb, "Block bitmap not in group (block %llu)",
170 (unsigned long long)input->block_bitmap);
171 else if (outside(input->inode_bitmap, start, end))
172 ext4_warning(sb, "Inode bitmap not in group (block %llu)",
173 (unsigned long long)input->inode_bitmap);
174 else if (outside(input->inode_table, start, end) ||
175 outside(itend - 1, start, end))
176 ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)",
177 (unsigned long long)input->inode_table, itend - 1);
178 else if (input->inode_bitmap == input->block_bitmap)
179 ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)",
180 (unsigned long long)input->block_bitmap);
181 else if (inside(input->block_bitmap, input->inode_table, itend))
182 ext4_warning(sb, "Block bitmap (%llu) in inode table "
183 "(%llu-%llu)",
184 (unsigned long long)input->block_bitmap,
185 (unsigned long long)input->inode_table, itend - 1);
186 else if (inside(input->inode_bitmap, input->inode_table, itend))
187 ext4_warning(sb, "Inode bitmap (%llu) in inode table "
188 "(%llu-%llu)",
189 (unsigned long long)input->inode_bitmap,
190 (unsigned long long)input->inode_table, itend - 1);
191 else if (inside(input->block_bitmap, start, metaend))
192 ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)",
193 (unsigned long long)input->block_bitmap,
194 start, metaend - 1);
195 else if (inside(input->inode_bitmap, start, metaend))
196 ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)",
197 (unsigned long long)input->inode_bitmap,
198 start, metaend - 1);
199 else if (inside(input->inode_table, start, metaend) ||
200 inside(itend - 1, start, metaend))
201 ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table "
202 "(%llu-%llu)",
203 (unsigned long long)input->inode_table,
204 itend - 1, start, metaend - 1);
205 else
206 err = 0;
207 brelse(bh);
208
209 return err;
210}
211
212/*
213 * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex
214 * group each time.
215 */
216struct ext4_new_flex_group_data {
217 struct ext4_new_group_data *groups; /* new_group_data for groups
218 in the flex group */
219 __u16 *bg_flags; /* block group flags of groups
220 in @groups */
221 ext4_group_t resize_bg; /* number of allocated
222 new_group_data */
223 ext4_group_t count; /* number of groups in @groups
224 */
225};
226
227/*
228 * Avoiding memory allocation failures due to too many groups added each time.
229 */
230#define MAX_RESIZE_BG 16384
231
232/*
233 * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of
234 * @flexbg_size.
235 *
236 * Returns NULL on failure otherwise address of the allocated structure.
237 */
238static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned int flexbg_size,
239 ext4_group_t o_group, ext4_group_t n_group)
240{
241 ext4_group_t last_group;
242 struct ext4_new_flex_group_data *flex_gd;
243
244 flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS);
245 if (flex_gd == NULL)
246 goto out3;
247
248 if (unlikely(flexbg_size > MAX_RESIZE_BG))
249 flex_gd->resize_bg = MAX_RESIZE_BG;
250 else
251 flex_gd->resize_bg = flexbg_size;
252
253 /* Avoid allocating large 'groups' array if not needed */
254 last_group = o_group | (flex_gd->resize_bg - 1);
255 if (n_group <= last_group)
256 flex_gd->resize_bg = 1 << fls(n_group - o_group + 1);
257 else if (n_group - last_group < flex_gd->resize_bg)
258 flex_gd->resize_bg = 1 << max(fls(last_group - o_group + 1),
259 fls(n_group - last_group));
260
261 flex_gd->groups = kmalloc_array(flex_gd->resize_bg,
262 sizeof(struct ext4_new_group_data),
263 GFP_NOFS);
264 if (flex_gd->groups == NULL)
265 goto out2;
266
267 flex_gd->bg_flags = kmalloc_array(flex_gd->resize_bg, sizeof(__u16),
268 GFP_NOFS);
269 if (flex_gd->bg_flags == NULL)
270 goto out1;
271
272 return flex_gd;
273
274out1:
275 kfree(flex_gd->groups);
276out2:
277 kfree(flex_gd);
278out3:
279 return NULL;
280}
281
282static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd)
283{
284 kfree(flex_gd->bg_flags);
285 kfree(flex_gd->groups);
286 kfree(flex_gd);
287}
288
289/*
290 * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps
291 * and inode tables for a flex group.
292 *
293 * This function is used by 64bit-resize. Note that this function allocates
294 * group tables from the 1st group of groups contained by @flexgd, which may
295 * be a partial of a flex group.
296 *
297 * @sb: super block of fs to which the groups belongs
298 *
299 * Returns 0 on a successful allocation of the metadata blocks in the
300 * block group.
301 */
302static int ext4_alloc_group_tables(struct super_block *sb,
303 struct ext4_new_flex_group_data *flex_gd,
304 unsigned int flexbg_size)
305{
306 struct ext4_new_group_data *group_data = flex_gd->groups;
307 ext4_fsblk_t start_blk;
308 ext4_fsblk_t last_blk;
309 ext4_group_t src_group;
310 ext4_group_t bb_index = 0;
311 ext4_group_t ib_index = 0;
312 ext4_group_t it_index = 0;
313 ext4_group_t group;
314 ext4_group_t last_group;
315 unsigned overhead;
316 __u16 uninit_mask = (flexbg_size > 1) ? ~EXT4_BG_BLOCK_UNINIT : ~0;
317 int i;
318
319 BUG_ON(flex_gd->count == 0 || group_data == NULL);
320
321 src_group = group_data[0].group;
322 last_group = src_group + flex_gd->count - 1;
323
324 BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) !=
325 (last_group & ~(flexbg_size - 1))));
326next_group:
327 group = group_data[0].group;
328 if (src_group >= group_data[0].group + flex_gd->count)
329 return -ENOSPC;
330 start_blk = ext4_group_first_block_no(sb, src_group);
331 last_blk = start_blk + group_data[src_group - group].blocks_count;
332
333 overhead = ext4_group_overhead_blocks(sb, src_group);
334
335 start_blk += overhead;
336
337 /* We collect contiguous blocks as much as possible. */
338 src_group++;
339 for (; src_group <= last_group; src_group++) {
340 overhead = ext4_group_overhead_blocks(sb, src_group);
341 if (overhead == 0)
342 last_blk += group_data[src_group - group].blocks_count;
343 else
344 break;
345 }
346
347 /* Allocate block bitmaps */
348 for (; bb_index < flex_gd->count; bb_index++) {
349 if (start_blk >= last_blk)
350 goto next_group;
351 group_data[bb_index].block_bitmap = start_blk++;
352 group = ext4_get_group_number(sb, start_blk - 1);
353 group -= group_data[0].group;
354 group_data[group].mdata_blocks++;
355 flex_gd->bg_flags[group] &= uninit_mask;
356 }
357
358 /* Allocate inode bitmaps */
359 for (; ib_index < flex_gd->count; ib_index++) {
360 if (start_blk >= last_blk)
361 goto next_group;
362 group_data[ib_index].inode_bitmap = start_blk++;
363 group = ext4_get_group_number(sb, start_blk - 1);
364 group -= group_data[0].group;
365 group_data[group].mdata_blocks++;
366 flex_gd->bg_flags[group] &= uninit_mask;
367 }
368
369 /* Allocate inode tables */
370 for (; it_index < flex_gd->count; it_index++) {
371 unsigned int itb = EXT4_SB(sb)->s_itb_per_group;
372 ext4_fsblk_t next_group_start;
373
374 if (start_blk + itb > last_blk)
375 goto next_group;
376 group_data[it_index].inode_table = start_blk;
377 group = ext4_get_group_number(sb, start_blk);
378 next_group_start = ext4_group_first_block_no(sb, group + 1);
379 group -= group_data[0].group;
380
381 if (start_blk + itb > next_group_start) {
382 flex_gd->bg_flags[group + 1] &= uninit_mask;
383 overhead = start_blk + itb - next_group_start;
384 group_data[group + 1].mdata_blocks += overhead;
385 itb -= overhead;
386 }
387
388 group_data[group].mdata_blocks += itb;
389 flex_gd->bg_flags[group] &= uninit_mask;
390 start_blk += EXT4_SB(sb)->s_itb_per_group;
391 }
392
393 /* Update free clusters count to exclude metadata blocks */
394 for (i = 0; i < flex_gd->count; i++) {
395 group_data[i].free_clusters_count -=
396 EXT4_NUM_B2C(EXT4_SB(sb),
397 group_data[i].mdata_blocks);
398 }
399
400 if (test_opt(sb, DEBUG)) {
401 int i;
402 group = group_data[0].group;
403
404 printk(KERN_DEBUG "EXT4-fs: adding a flex group with "
405 "%u groups, flexbg size is %u:\n", flex_gd->count,
406 flexbg_size);
407
408 for (i = 0; i < flex_gd->count; i++) {
409 ext4_debug(
410 "adding %s group %u: %u blocks (%u free, %u mdata blocks)\n",
411 ext4_bg_has_super(sb, group + i) ? "normal" :
412 "no-super", group + i,
413 group_data[i].blocks_count,
414 group_data[i].free_clusters_count,
415 group_data[i].mdata_blocks);
416 }
417 }
418 return 0;
419}
420
421static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
422 ext4_fsblk_t blk)
423{
424 struct buffer_head *bh;
425 int err;
426
427 bh = sb_getblk(sb, blk);
428 if (unlikely(!bh))
429 return ERR_PTR(-ENOMEM);
430 BUFFER_TRACE(bh, "get_write_access");
431 err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
432 if (err) {
433 brelse(bh);
434 bh = ERR_PTR(err);
435 } else {
436 memset(bh->b_data, 0, sb->s_blocksize);
437 set_buffer_uptodate(bh);
438 }
439
440 return bh;
441}
442
443static int ext4_resize_ensure_credits_batch(handle_t *handle, int credits)
444{
445 return ext4_journal_ensure_credits_fn(handle, credits,
446 EXT4_MAX_TRANS_DATA, 0, 0);
447}
448
449/*
450 * set_flexbg_block_bitmap() mark clusters [@first_cluster, @last_cluster] used.
451 *
452 * Helper function for ext4_setup_new_group_blocks() which set .
453 *
454 * @sb: super block
455 * @handle: journal handle
456 * @flex_gd: flex group data
457 */
458static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle,
459 struct ext4_new_flex_group_data *flex_gd,
460 ext4_fsblk_t first_cluster, ext4_fsblk_t last_cluster)
461{
462 struct ext4_sb_info *sbi = EXT4_SB(sb);
463 ext4_group_t count = last_cluster - first_cluster + 1;
464 ext4_group_t count2;
465
466 ext4_debug("mark clusters [%llu-%llu] used\n", first_cluster,
467 last_cluster);
468 for (; count > 0; count -= count2, first_cluster += count2) {
469 ext4_fsblk_t start;
470 struct buffer_head *bh;
471 ext4_group_t group;
472 int err;
473
474 group = ext4_get_group_number(sb, EXT4_C2B(sbi, first_cluster));
475 start = EXT4_B2C(sbi, ext4_group_first_block_no(sb, group));
476 group -= flex_gd->groups[0].group;
477
478 count2 = EXT4_CLUSTERS_PER_GROUP(sb) - (first_cluster - start);
479 if (count2 > count)
480 count2 = count;
481
482 if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) {
483 BUG_ON(flex_gd->count > 1);
484 continue;
485 }
486
487 err = ext4_resize_ensure_credits_batch(handle, 1);
488 if (err < 0)
489 return err;
490
491 bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap);
492 if (unlikely(!bh))
493 return -ENOMEM;
494
495 BUFFER_TRACE(bh, "get_write_access");
496 err = ext4_journal_get_write_access(handle, sb, bh,
497 EXT4_JTR_NONE);
498 if (err) {
499 brelse(bh);
500 return err;
501 }
502 ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n",
503 first_cluster, first_cluster - start, count2);
504 mb_set_bits(bh->b_data, first_cluster - start, count2);
505
506 err = ext4_handle_dirty_metadata(handle, NULL, bh);
507 brelse(bh);
508 if (unlikely(err))
509 return err;
510 }
511
512 return 0;
513}
514
515/*
516 * Set up the block and inode bitmaps, and the inode table for the new groups.
517 * This doesn't need to be part of the main transaction, since we are only
518 * changing blocks outside the actual filesystem. We still do journaling to
519 * ensure the recovery is correct in case of a failure just after resize.
520 * If any part of this fails, we simply abort the resize.
521 *
522 * setup_new_flex_group_blocks handles a flex group as follow:
523 * 1. copy super block and GDT, and initialize group tables if necessary.
524 * In this step, we only set bits in blocks bitmaps for blocks taken by
525 * super block and GDT.
526 * 2. allocate group tables in block bitmaps, that is, set bits in block
527 * bitmap for blocks taken by group tables.
528 */
529static int setup_new_flex_group_blocks(struct super_block *sb,
530 struct ext4_new_flex_group_data *flex_gd)
531{
532 int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group};
533 ext4_fsblk_t start;
534 ext4_fsblk_t block;
535 struct ext4_sb_info *sbi = EXT4_SB(sb);
536 struct ext4_super_block *es = sbi->s_es;
537 struct ext4_new_group_data *group_data = flex_gd->groups;
538 __u16 *bg_flags = flex_gd->bg_flags;
539 handle_t *handle;
540 ext4_group_t group, count;
541 struct buffer_head *bh = NULL;
542 int reserved_gdb, i, j, err = 0, err2;
543 int meta_bg;
544
545 BUG_ON(!flex_gd->count || !group_data ||
546 group_data[0].group != sbi->s_groups_count);
547
548 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
549 meta_bg = ext4_has_feature_meta_bg(sb);
550
551 /* This transaction may be extended/restarted along the way */
552 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA);
553 if (IS_ERR(handle))
554 return PTR_ERR(handle);
555
556 group = group_data[0].group;
557 for (i = 0; i < flex_gd->count; i++, group++) {
558 unsigned long gdblocks;
559 ext4_grpblk_t overhead;
560
561 gdblocks = ext4_bg_num_gdb(sb, group);
562 start = ext4_group_first_block_no(sb, group);
563
564 if (meta_bg == 0 && !ext4_bg_has_super(sb, group))
565 goto handle_itb;
566
567 if (meta_bg == 1)
568 goto handle_itb;
569
570 block = start + ext4_bg_has_super(sb, group);
571 /* Copy all of the GDT blocks into the backup in this group */
572 for (j = 0; j < gdblocks; j++, block++) {
573 struct buffer_head *gdb;
574
575 ext4_debug("update backup group %#04llx\n", block);
576 err = ext4_resize_ensure_credits_batch(handle, 1);
577 if (err < 0)
578 goto out;
579
580 gdb = sb_getblk(sb, block);
581 if (unlikely(!gdb)) {
582 err = -ENOMEM;
583 goto out;
584 }
585
586 BUFFER_TRACE(gdb, "get_write_access");
587 err = ext4_journal_get_write_access(handle, sb, gdb,
588 EXT4_JTR_NONE);
589 if (err) {
590 brelse(gdb);
591 goto out;
592 }
593 memcpy(gdb->b_data, sbi_array_rcu_deref(sbi,
594 s_group_desc, j)->b_data, gdb->b_size);
595 set_buffer_uptodate(gdb);
596
597 err = ext4_handle_dirty_metadata(handle, NULL, gdb);
598 if (unlikely(err)) {
599 brelse(gdb);
600 goto out;
601 }
602 brelse(gdb);
603 }
604
605 /* Zero out all of the reserved backup group descriptor
606 * table blocks
607 */
608 if (ext4_bg_has_super(sb, group)) {
609 err = sb_issue_zeroout(sb, gdblocks + start + 1,
610 reserved_gdb, GFP_NOFS);
611 if (err)
612 goto out;
613 }
614
615handle_itb:
616 /* Initialize group tables of the group @group */
617 if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED))
618 goto handle_bb;
619
620 /* Zero out all of the inode table blocks */
621 block = group_data[i].inode_table;
622 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n",
623 block, sbi->s_itb_per_group);
624 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group,
625 GFP_NOFS);
626 if (err)
627 goto out;
628
629handle_bb:
630 if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT)
631 goto handle_ib;
632
633 /* Initialize block bitmap of the @group */
634 block = group_data[i].block_bitmap;
635 err = ext4_resize_ensure_credits_batch(handle, 1);
636 if (err < 0)
637 goto out;
638
639 bh = bclean(handle, sb, block);
640 if (IS_ERR(bh)) {
641 err = PTR_ERR(bh);
642 goto out;
643 }
644 overhead = ext4_group_overhead_blocks(sb, group);
645 if (overhead != 0) {
646 ext4_debug("mark backup superblock %#04llx (+0)\n",
647 start);
648 mb_set_bits(bh->b_data, 0,
649 EXT4_NUM_B2C(sbi, overhead));
650 }
651 ext4_mark_bitmap_end(EXT4_B2C(sbi, group_data[i].blocks_count),
652 sb->s_blocksize * 8, bh->b_data);
653 err = ext4_handle_dirty_metadata(handle, NULL, bh);
654 brelse(bh);
655 if (err)
656 goto out;
657
658handle_ib:
659 if (bg_flags[i] & EXT4_BG_INODE_UNINIT)
660 continue;
661
662 /* Initialize inode bitmap of the @group */
663 block = group_data[i].inode_bitmap;
664 err = ext4_resize_ensure_credits_batch(handle, 1);
665 if (err < 0)
666 goto out;
667 /* Mark unused entries in inode bitmap used */
668 bh = bclean(handle, sb, block);
669 if (IS_ERR(bh)) {
670 err = PTR_ERR(bh);
671 goto out;
672 }
673
674 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
675 sb->s_blocksize * 8, bh->b_data);
676 err = ext4_handle_dirty_metadata(handle, NULL, bh);
677 brelse(bh);
678 if (err)
679 goto out;
680 }
681
682 /* Mark group tables in block bitmap */
683 for (j = 0; j < GROUP_TABLE_COUNT; j++) {
684 count = group_table_count[j];
685 start = (&group_data[0].block_bitmap)[j];
686 block = start;
687 for (i = 1; i < flex_gd->count; i++) {
688 block += group_table_count[j];
689 if (block == (&group_data[i].block_bitmap)[j]) {
690 count += group_table_count[j];
691 continue;
692 }
693 err = set_flexbg_block_bitmap(sb, handle,
694 flex_gd,
695 EXT4_B2C(sbi, start),
696 EXT4_B2C(sbi,
697 start + count
698 - 1));
699 if (err)
700 goto out;
701 count = group_table_count[j];
702 start = (&group_data[i].block_bitmap)[j];
703 block = start;
704 }
705
706 err = set_flexbg_block_bitmap(sb, handle,
707 flex_gd,
708 EXT4_B2C(sbi, start),
709 EXT4_B2C(sbi,
710 start + count
711 - 1));
712 if (err)
713 goto out;
714 }
715
716out:
717 err2 = ext4_journal_stop(handle);
718 if (err2 && !err)
719 err = err2;
720
721 return err;
722}
723
724/*
725 * Iterate through the groups which hold BACKUP superblock/GDT copies in an
726 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
727 * calling this for the first time. In a sparse filesystem it will be the
728 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
729 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
730 */
731unsigned int ext4_list_backups(struct super_block *sb, unsigned int *three,
732 unsigned int *five, unsigned int *seven)
733{
734 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
735 unsigned int *min = three;
736 int mult = 3;
737 unsigned int ret;
738
739 if (ext4_has_feature_sparse_super2(sb)) {
740 do {
741 if (*min > 2)
742 return UINT_MAX;
743 ret = le32_to_cpu(es->s_backup_bgs[*min - 1]);
744 *min += 1;
745 } while (!ret);
746 return ret;
747 }
748
749 if (!ext4_has_feature_sparse_super(sb)) {
750 ret = *min;
751 *min += 1;
752 return ret;
753 }
754
755 if (*five < *min) {
756 min = five;
757 mult = 5;
758 }
759 if (*seven < *min) {
760 min = seven;
761 mult = 7;
762 }
763
764 ret = *min;
765 *min *= mult;
766
767 return ret;
768}
769
770/*
771 * Check that all of the backup GDT blocks are held in the primary GDT block.
772 * It is assumed that they are stored in group order. Returns the number of
773 * groups in current filesystem that have BACKUPS, or -ve error code.
774 */
775static int verify_reserved_gdb(struct super_block *sb,
776 ext4_group_t end,
777 struct buffer_head *primary)
778{
779 const ext4_fsblk_t blk = primary->b_blocknr;
780 unsigned three = 1;
781 unsigned five = 5;
782 unsigned seven = 7;
783 unsigned grp;
784 __le32 *p = (__le32 *)primary->b_data;
785 int gdbackups = 0;
786
787 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) {
788 if (le32_to_cpu(*p++) !=
789 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){
790 ext4_warning(sb, "reserved GDT %llu"
791 " missing grp %d (%llu)",
792 blk, grp,
793 grp *
794 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
795 blk);
796 return -EINVAL;
797 }
798 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb))
799 return -EFBIG;
800 }
801
802 return gdbackups;
803}
804
805/*
806 * Called when we need to bring a reserved group descriptor table block into
807 * use from the resize inode. The primary copy of the new GDT block currently
808 * is an indirect block (under the double indirect block in the resize inode).
809 * The new backup GDT blocks will be stored as leaf blocks in this indirect
810 * block, in group order. Even though we know all the block numbers we need,
811 * we check to ensure that the resize inode has actually reserved these blocks.
812 *
813 * Don't need to update the block bitmaps because the blocks are still in use.
814 *
815 * We get all of the error cases out of the way, so that we are sure to not
816 * fail once we start modifying the data on disk, because JBD has no rollback.
817 */
818static int add_new_gdb(handle_t *handle, struct inode *inode,
819 ext4_group_t group)
820{
821 struct super_block *sb = inode->i_sb;
822 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
823 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
824 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
825 struct buffer_head **o_group_desc, **n_group_desc = NULL;
826 struct buffer_head *dind = NULL;
827 struct buffer_head *gdb_bh = NULL;
828 int gdbackups;
829 struct ext4_iloc iloc = { .bh = NULL };
830 __le32 *data;
831 int err;
832
833 if (test_opt(sb, DEBUG))
834 printk(KERN_DEBUG
835 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
836 gdb_num);
837
838 gdb_bh = ext4_sb_bread(sb, gdblock, 0);
839 if (IS_ERR(gdb_bh))
840 return PTR_ERR(gdb_bh);
841
842 gdbackups = verify_reserved_gdb(sb, group, gdb_bh);
843 if (gdbackups < 0) {
844 err = gdbackups;
845 goto errout;
846 }
847
848 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
849 dind = ext4_sb_bread(sb, le32_to_cpu(*data), 0);
850 if (IS_ERR(dind)) {
851 err = PTR_ERR(dind);
852 dind = NULL;
853 goto errout;
854 }
855
856 data = (__le32 *)dind->b_data;
857 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) {
858 ext4_warning(sb, "new group %u GDT block %llu not reserved",
859 group, gdblock);
860 err = -EINVAL;
861 goto errout;
862 }
863
864 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
865 err = ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh,
866 EXT4_JTR_NONE);
867 if (unlikely(err))
868 goto errout;
869
870 BUFFER_TRACE(gdb_bh, "get_write_access");
871 err = ext4_journal_get_write_access(handle, sb, gdb_bh, EXT4_JTR_NONE);
872 if (unlikely(err))
873 goto errout;
874
875 BUFFER_TRACE(dind, "get_write_access");
876 err = ext4_journal_get_write_access(handle, sb, dind, EXT4_JTR_NONE);
877 if (unlikely(err)) {
878 ext4_std_error(sb, err);
879 goto errout;
880 }
881
882 /* ext4_reserve_inode_write() gets a reference on the iloc */
883 err = ext4_reserve_inode_write(handle, inode, &iloc);
884 if (unlikely(err))
885 goto errout;
886
887 n_group_desc = kvmalloc((gdb_num + 1) * sizeof(struct buffer_head *),
888 GFP_KERNEL);
889 if (!n_group_desc) {
890 err = -ENOMEM;
891 ext4_warning(sb, "not enough memory for %lu groups",
892 gdb_num + 1);
893 goto errout;
894 }
895
896 /*
897 * Finally, we have all of the possible failures behind us...
898 *
899 * Remove new GDT block from inode double-indirect block and clear out
900 * the new GDT block for use (which also "frees" the backup GDT blocks
901 * from the reserved inode). We don't need to change the bitmaps for
902 * these blocks, because they are marked as in-use from being in the
903 * reserved inode, and will become GDT blocks (primary and backup).
904 */
905 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0;
906 err = ext4_handle_dirty_metadata(handle, NULL, dind);
907 if (unlikely(err)) {
908 ext4_std_error(sb, err);
909 goto errout;
910 }
911 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >>
912 (9 - EXT4_SB(sb)->s_cluster_bits);
913 ext4_mark_iloc_dirty(handle, inode, &iloc);
914 memset(gdb_bh->b_data, 0, sb->s_blocksize);
915 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
916 if (unlikely(err)) {
917 ext4_std_error(sb, err);
918 iloc.bh = NULL;
919 goto errout;
920 }
921 brelse(dind);
922
923 rcu_read_lock();
924 o_group_desc = rcu_dereference(EXT4_SB(sb)->s_group_desc);
925 memcpy(n_group_desc, o_group_desc,
926 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
927 rcu_read_unlock();
928 n_group_desc[gdb_num] = gdb_bh;
929 rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc);
930 EXT4_SB(sb)->s_gdb_count++;
931 ext4_kvfree_array_rcu(o_group_desc);
932
933 lock_buffer(EXT4_SB(sb)->s_sbh);
934 le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
935 ext4_superblock_csum_set(sb);
936 unlock_buffer(EXT4_SB(sb)->s_sbh);
937 err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
938 if (err)
939 ext4_std_error(sb, err);
940 return err;
941errout:
942 kvfree(n_group_desc);
943 brelse(iloc.bh);
944 brelse(dind);
945 brelse(gdb_bh);
946
947 ext4_debug("leaving with error %d\n", err);
948 return err;
949}
950
951/*
952 * If there is no available space in the existing block group descriptors for
953 * the new block group and there are no reserved block group descriptors, then
954 * the meta_bg feature will get enabled, and es->s_first_meta_bg will get set
955 * to the first block group that is managed using meta_bg and s_first_meta_bg
956 * must be a multiple of EXT4_DESC_PER_BLOCK(sb).
957 * This function will be called when first group of meta_bg is added to bring
958 * new group descriptors block of new added meta_bg.
959 */
960static int add_new_gdb_meta_bg(struct super_block *sb,
961 handle_t *handle, ext4_group_t group) {
962 ext4_fsblk_t gdblock;
963 struct buffer_head *gdb_bh;
964 struct buffer_head **o_group_desc, **n_group_desc;
965 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
966 int err;
967
968 gdblock = ext4_group_first_block_no(sb, group) +
969 ext4_bg_has_super(sb, group);
970 gdb_bh = ext4_sb_bread(sb, gdblock, 0);
971 if (IS_ERR(gdb_bh))
972 return PTR_ERR(gdb_bh);
973 n_group_desc = kvmalloc((gdb_num + 1) * sizeof(struct buffer_head *),
974 GFP_KERNEL);
975 if (!n_group_desc) {
976 brelse(gdb_bh);
977 err = -ENOMEM;
978 ext4_warning(sb, "not enough memory for %lu groups",
979 gdb_num + 1);
980 return err;
981 }
982
983 rcu_read_lock();
984 o_group_desc = rcu_dereference(EXT4_SB(sb)->s_group_desc);
985 memcpy(n_group_desc, o_group_desc,
986 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
987 rcu_read_unlock();
988 n_group_desc[gdb_num] = gdb_bh;
989
990 BUFFER_TRACE(gdb_bh, "get_write_access");
991 err = ext4_journal_get_write_access(handle, sb, gdb_bh, EXT4_JTR_NONE);
992 if (err) {
993 kvfree(n_group_desc);
994 brelse(gdb_bh);
995 return err;
996 }
997
998 rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc);
999 EXT4_SB(sb)->s_gdb_count++;
1000 ext4_kvfree_array_rcu(o_group_desc);
1001 return err;
1002}
1003
1004/*
1005 * Called when we are adding a new group which has a backup copy of each of
1006 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
1007 * We need to add these reserved backup GDT blocks to the resize inode, so
1008 * that they are kept for future resizing and not allocated to files.
1009 *
1010 * Each reserved backup GDT block will go into a different indirect block.
1011 * The indirect blocks are actually the primary reserved GDT blocks,
1012 * so we know in advance what their block numbers are. We only get the
1013 * double-indirect block to verify it is pointing to the primary reserved
1014 * GDT blocks so we don't overwrite a data block by accident. The reserved
1015 * backup GDT blocks are stored in their reserved primary GDT block.
1016 */
1017static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
1018 ext4_group_t group)
1019{
1020 struct super_block *sb = inode->i_sb;
1021 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
1022 int cluster_bits = EXT4_SB(sb)->s_cluster_bits;
1023 struct buffer_head **primary;
1024 struct buffer_head *dind;
1025 struct ext4_iloc iloc;
1026 ext4_fsblk_t blk;
1027 __le32 *data, *end;
1028 int gdbackups = 0;
1029 int res, i;
1030 int err;
1031
1032 primary = kmalloc_array(reserved_gdb, sizeof(*primary), GFP_NOFS);
1033 if (!primary)
1034 return -ENOMEM;
1035
1036 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
1037 dind = ext4_sb_bread(sb, le32_to_cpu(*data), 0);
1038 if (IS_ERR(dind)) {
1039 err = PTR_ERR(dind);
1040 dind = NULL;
1041 goto exit_free;
1042 }
1043
1044 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count;
1045 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count %
1046 EXT4_ADDR_PER_BLOCK(sb));
1047 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb);
1048
1049 /* Get each reserved primary GDT block and verify it holds backups */
1050 for (res = 0; res < reserved_gdb; res++, blk++) {
1051 if (le32_to_cpu(*data) != blk) {
1052 ext4_warning(sb, "reserved block %llu"
1053 " not at offset %ld",
1054 blk,
1055 (long)(data - (__le32 *)dind->b_data));
1056 err = -EINVAL;
1057 goto exit_bh;
1058 }
1059 primary[res] = ext4_sb_bread(sb, blk, 0);
1060 if (IS_ERR(primary[res])) {
1061 err = PTR_ERR(primary[res]);
1062 primary[res] = NULL;
1063 goto exit_bh;
1064 }
1065 gdbackups = verify_reserved_gdb(sb, group, primary[res]);
1066 if (gdbackups < 0) {
1067 brelse(primary[res]);
1068 err = gdbackups;
1069 goto exit_bh;
1070 }
1071 if (++data >= end)
1072 data = (__le32 *)dind->b_data;
1073 }
1074
1075 for (i = 0; i < reserved_gdb; i++) {
1076 BUFFER_TRACE(primary[i], "get_write_access");
1077 if ((err = ext4_journal_get_write_access(handle, sb, primary[i],
1078 EXT4_JTR_NONE)))
1079 goto exit_bh;
1080 }
1081
1082 if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
1083 goto exit_bh;
1084
1085 /*
1086 * Finally we can add each of the reserved backup GDT blocks from
1087 * the new group to its reserved primary GDT block.
1088 */
1089 blk = group * EXT4_BLOCKS_PER_GROUP(sb);
1090 for (i = 0; i < reserved_gdb; i++) {
1091 int err2;
1092 data = (__le32 *)primary[i]->b_data;
1093 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
1094 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]);
1095 if (!err)
1096 err = err2;
1097 }
1098
1099 inode->i_blocks += reserved_gdb * sb->s_blocksize >> (9 - cluster_bits);
1100 ext4_mark_iloc_dirty(handle, inode, &iloc);
1101
1102exit_bh:
1103 while (--res >= 0)
1104 brelse(primary[res]);
1105 brelse(dind);
1106
1107exit_free:
1108 kfree(primary);
1109
1110 return err;
1111}
1112
1113static inline void ext4_set_block_group_nr(struct super_block *sb, char *data,
1114 ext4_group_t group)
1115{
1116 struct ext4_super_block *es = (struct ext4_super_block *) data;
1117
1118 es->s_block_group_nr = cpu_to_le16(group);
1119 if (ext4_has_metadata_csum(sb))
1120 es->s_checksum = ext4_superblock_csum(sb, es);
1121}
1122
1123/*
1124 * Update the backup copies of the ext4 metadata. These don't need to be part
1125 * of the main resize transaction, because e2fsck will re-write them if there
1126 * is a problem (basically only OOM will cause a problem). However, we
1127 * _should_ update the backups if possible, in case the primary gets trashed
1128 * for some reason and we need to run e2fsck from a backup superblock. The
1129 * important part is that the new block and inode counts are in the backup
1130 * superblocks, and the location of the new group metadata in the GDT backups.
1131 *
1132 * We do not need take the s_resize_lock for this, because these
1133 * blocks are not otherwise touched by the filesystem code when it is
1134 * mounted. We don't need to worry about last changing from
1135 * sbi->s_groups_count, because the worst that can happen is that we
1136 * do not copy the full number of backups at this time. The resize
1137 * which changed s_groups_count will backup again.
1138 */
1139static void update_backups(struct super_block *sb, sector_t blk_off, char *data,
1140 int size, int meta_bg)
1141{
1142 struct ext4_sb_info *sbi = EXT4_SB(sb);
1143 ext4_group_t last;
1144 const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
1145 unsigned three = 1;
1146 unsigned five = 5;
1147 unsigned seven = 7;
1148 ext4_group_t group = 0;
1149 int rest = sb->s_blocksize - size;
1150 handle_t *handle;
1151 int err = 0, err2;
1152
1153 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA);
1154 if (IS_ERR(handle)) {
1155 group = 1;
1156 err = PTR_ERR(handle);
1157 goto exit_err;
1158 }
1159
1160 if (meta_bg == 0) {
1161 group = ext4_list_backups(sb, &three, &five, &seven);
1162 last = sbi->s_groups_count;
1163 } else {
1164 group = ext4_get_group_number(sb, blk_off) + 1;
1165 last = (ext4_group_t)(group + EXT4_DESC_PER_BLOCK(sb) - 2);
1166 }
1167
1168 while (group < sbi->s_groups_count) {
1169 struct buffer_head *bh;
1170 ext4_fsblk_t backup_block;
1171 int has_super = ext4_bg_has_super(sb, group);
1172 ext4_fsblk_t first_block = ext4_group_first_block_no(sb, group);
1173
1174 /* Out of journal space, and can't get more - abort - so sad */
1175 err = ext4_resize_ensure_credits_batch(handle, 1);
1176 if (err < 0)
1177 break;
1178
1179 if (meta_bg == 0)
1180 backup_block = ((ext4_fsblk_t)group) * bpg + blk_off;
1181 else
1182 backup_block = first_block + has_super;
1183
1184 bh = sb_getblk(sb, backup_block);
1185 if (unlikely(!bh)) {
1186 err = -ENOMEM;
1187 break;
1188 }
1189 ext4_debug("update metadata backup %llu(+%llu)\n",
1190 backup_block, backup_block -
1191 ext4_group_first_block_no(sb, group));
1192 BUFFER_TRACE(bh, "get_write_access");
1193 if ((err = ext4_journal_get_write_access(handle, sb, bh,
1194 EXT4_JTR_NONE))) {
1195 brelse(bh);
1196 break;
1197 }
1198 lock_buffer(bh);
1199 memcpy(bh->b_data, data, size);
1200 if (rest)
1201 memset(bh->b_data + size, 0, rest);
1202 if (has_super && (backup_block == first_block))
1203 ext4_set_block_group_nr(sb, bh->b_data, group);
1204 set_buffer_uptodate(bh);
1205 unlock_buffer(bh);
1206 err = ext4_handle_dirty_metadata(handle, NULL, bh);
1207 if (unlikely(err))
1208 ext4_std_error(sb, err);
1209 brelse(bh);
1210
1211 if (meta_bg == 0)
1212 group = ext4_list_backups(sb, &three, &five, &seven);
1213 else if (group == last)
1214 break;
1215 else
1216 group = last;
1217 }
1218 if ((err2 = ext4_journal_stop(handle)) && !err)
1219 err = err2;
1220
1221 /*
1222 * Ugh! Need to have e2fsck write the backup copies. It is too
1223 * late to revert the resize, we shouldn't fail just because of
1224 * the backup copies (they are only needed in case of corruption).
1225 *
1226 * However, if we got here we have a journal problem too, so we
1227 * can't really start a transaction to mark the superblock.
1228 * Chicken out and just set the flag on the hope it will be written
1229 * to disk, and if not - we will simply wait until next fsck.
1230 */
1231exit_err:
1232 if (err) {
1233 ext4_warning(sb, "can't update backup for group %u (err %d), "
1234 "forcing fsck on next reboot", group, err);
1235 sbi->s_mount_state &= ~EXT4_VALID_FS;
1236 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1237 mark_buffer_dirty(sbi->s_sbh);
1238 }
1239}
1240
1241/*
1242 * ext4_add_new_descs() adds @count group descriptor of groups
1243 * starting at @group
1244 *
1245 * @handle: journal handle
1246 * @sb: super block
1247 * @group: the group no. of the first group desc to be added
1248 * @resize_inode: the resize inode
1249 * @count: number of group descriptors to be added
1250 */
1251static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
1252 ext4_group_t group, struct inode *resize_inode,
1253 ext4_group_t count)
1254{
1255 struct ext4_sb_info *sbi = EXT4_SB(sb);
1256 struct ext4_super_block *es = sbi->s_es;
1257 struct buffer_head *gdb_bh;
1258 int i, gdb_off, gdb_num, err = 0;
1259 int meta_bg;
1260
1261 meta_bg = ext4_has_feature_meta_bg(sb);
1262 for (i = 0; i < count; i++, group++) {
1263 int reserved_gdb = ext4_bg_has_super(sb, group) ?
1264 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
1265
1266 gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
1267 gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1268
1269 /*
1270 * We will only either add reserved group blocks to a backup group
1271 * or remove reserved blocks for the first group in a new group block.
1272 * Doing both would be mean more complex code, and sane people don't
1273 * use non-sparse filesystems anymore. This is already checked above.
1274 */
1275 if (gdb_off) {
1276 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc,
1277 gdb_num);
1278 BUFFER_TRACE(gdb_bh, "get_write_access");
1279 err = ext4_journal_get_write_access(handle, sb, gdb_bh,
1280 EXT4_JTR_NONE);
1281
1282 if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group))
1283 err = reserve_backup_gdb(handle, resize_inode, group);
1284 } else if (meta_bg != 0) {
1285 err = add_new_gdb_meta_bg(sb, handle, group);
1286 } else {
1287 err = add_new_gdb(handle, resize_inode, group);
1288 }
1289 if (err)
1290 break;
1291 }
1292 return err;
1293}
1294
1295static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block)
1296{
1297 struct buffer_head *bh = sb_getblk(sb, block);
1298 if (unlikely(!bh))
1299 return NULL;
1300 if (!bh_uptodate_or_lock(bh)) {
1301 if (ext4_read_bh(bh, 0, NULL) < 0) {
1302 brelse(bh);
1303 return NULL;
1304 }
1305 }
1306
1307 return bh;
1308}
1309
1310static int ext4_set_bitmap_checksums(struct super_block *sb,
1311 struct ext4_group_desc *gdp,
1312 struct ext4_new_group_data *group_data)
1313{
1314 struct buffer_head *bh;
1315
1316 if (!ext4_has_metadata_csum(sb))
1317 return 0;
1318
1319 bh = ext4_get_bitmap(sb, group_data->inode_bitmap);
1320 if (!bh)
1321 return -EIO;
1322 ext4_inode_bitmap_csum_set(sb, gdp, bh,
1323 EXT4_INODES_PER_GROUP(sb) / 8);
1324 brelse(bh);
1325
1326 bh = ext4_get_bitmap(sb, group_data->block_bitmap);
1327 if (!bh)
1328 return -EIO;
1329 ext4_block_bitmap_csum_set(sb, gdp, bh);
1330 brelse(bh);
1331
1332 return 0;
1333}
1334
1335/*
1336 * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg
1337 */
1338static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb,
1339 struct ext4_new_flex_group_data *flex_gd)
1340{
1341 struct ext4_new_group_data *group_data = flex_gd->groups;
1342 struct ext4_group_desc *gdp;
1343 struct ext4_sb_info *sbi = EXT4_SB(sb);
1344 struct buffer_head *gdb_bh;
1345 ext4_group_t group;
1346 __u16 *bg_flags = flex_gd->bg_flags;
1347 int i, gdb_off, gdb_num, err = 0;
1348
1349
1350 for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) {
1351 group = group_data->group;
1352
1353 gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
1354 gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1355
1356 /*
1357 * get_write_access() has been called on gdb_bh by ext4_add_new_desc().
1358 */
1359 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc, gdb_num);
1360 /* Update group descriptor block for new group */
1361 gdp = (struct ext4_group_desc *)(gdb_bh->b_data +
1362 gdb_off * EXT4_DESC_SIZE(sb));
1363
1364 memset(gdp, 0, EXT4_DESC_SIZE(sb));
1365 ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap);
1366 ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap);
1367 err = ext4_set_bitmap_checksums(sb, gdp, group_data);
1368 if (err) {
1369 ext4_std_error(sb, err);
1370 break;
1371 }
1372
1373 ext4_inode_table_set(sb, gdp, group_data->inode_table);
1374 ext4_free_group_clusters_set(sb, gdp,
1375 group_data->free_clusters_count);
1376 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
1377 if (ext4_has_group_desc_csum(sb))
1378 ext4_itable_unused_set(sb, gdp,
1379 EXT4_INODES_PER_GROUP(sb));
1380 gdp->bg_flags = cpu_to_le16(*bg_flags);
1381 ext4_group_desc_csum_set(sb, group, gdp);
1382
1383 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
1384 if (unlikely(err)) {
1385 ext4_std_error(sb, err);
1386 break;
1387 }
1388
1389 /*
1390 * We can allocate memory for mb_alloc based on the new group
1391 * descriptor
1392 */
1393 err = ext4_mb_add_groupinfo(sb, group, gdp);
1394 if (err)
1395 break;
1396 }
1397 return err;
1398}
1399
1400static void ext4_add_overhead(struct super_block *sb,
1401 const ext4_fsblk_t overhead)
1402{
1403 struct ext4_sb_info *sbi = EXT4_SB(sb);
1404 struct ext4_super_block *es = sbi->s_es;
1405
1406 sbi->s_overhead += overhead;
1407 es->s_overhead_clusters = cpu_to_le32(sbi->s_overhead);
1408 smp_wmb();
1409}
1410
1411/*
1412 * ext4_update_super() updates the super block so that the newly added
1413 * groups can be seen by the filesystem.
1414 *
1415 * @sb: super block
1416 * @flex_gd: new added groups
1417 */
1418static void ext4_update_super(struct super_block *sb,
1419 struct ext4_new_flex_group_data *flex_gd)
1420{
1421 ext4_fsblk_t blocks_count = 0;
1422 ext4_fsblk_t free_blocks = 0;
1423 ext4_fsblk_t reserved_blocks = 0;
1424 struct ext4_new_group_data *group_data = flex_gd->groups;
1425 struct ext4_sb_info *sbi = EXT4_SB(sb);
1426 struct ext4_super_block *es = sbi->s_es;
1427 int i;
1428
1429 BUG_ON(flex_gd->count == 0 || group_data == NULL);
1430 /*
1431 * Make the new blocks and inodes valid next. We do this before
1432 * increasing the group count so that once the group is enabled,
1433 * all of its blocks and inodes are already valid.
1434 *
1435 * We always allocate group-by-group, then block-by-block or
1436 * inode-by-inode within a group, so enabling these
1437 * blocks/inodes before the group is live won't actually let us
1438 * allocate the new space yet.
1439 */
1440 for (i = 0; i < flex_gd->count; i++) {
1441 blocks_count += group_data[i].blocks_count;
1442 free_blocks += EXT4_C2B(sbi, group_data[i].free_clusters_count);
1443 }
1444
1445 reserved_blocks = ext4_r_blocks_count(es) * 100;
1446 reserved_blocks = div64_u64(reserved_blocks, ext4_blocks_count(es));
1447 reserved_blocks *= blocks_count;
1448 do_div(reserved_blocks, 100);
1449
1450 lock_buffer(sbi->s_sbh);
1451 ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count);
1452 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks);
1453 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) *
1454 flex_gd->count);
1455 le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) *
1456 flex_gd->count);
1457
1458 ext4_debug("free blocks count %llu", ext4_free_blocks_count(es));
1459 /*
1460 * We need to protect s_groups_count against other CPUs seeing
1461 * inconsistent state in the superblock.
1462 *
1463 * The precise rules we use are:
1464 *
1465 * * Writers must perform a smp_wmb() after updating all
1466 * dependent data and before modifying the groups count
1467 *
1468 * * Readers must perform an smp_rmb() after reading the groups
1469 * count and before reading any dependent data.
1470 *
1471 * NB. These rules can be relaxed when checking the group count
1472 * while freeing data, as we can only allocate from a block
1473 * group after serialising against the group count, and we can
1474 * only then free after serialising in turn against that
1475 * allocation.
1476 */
1477 smp_wmb();
1478
1479 /* Update the global fs size fields */
1480 sbi->s_groups_count += flex_gd->count;
1481 sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
1482 (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
1483
1484 /* Update the reserved block counts only once the new group is
1485 * active. */
1486 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) +
1487 reserved_blocks);
1488
1489 /* Update the free space counts */
1490 percpu_counter_add(&sbi->s_freeclusters_counter,
1491 EXT4_NUM_B2C(sbi, free_blocks));
1492 percpu_counter_add(&sbi->s_freeinodes_counter,
1493 EXT4_INODES_PER_GROUP(sb) * flex_gd->count);
1494
1495 ext4_debug("free blocks count %llu",
1496 percpu_counter_read(&sbi->s_freeclusters_counter));
1497 if (ext4_has_feature_flex_bg(sb) && sbi->s_log_groups_per_flex) {
1498 ext4_group_t flex_group;
1499 struct flex_groups *fg;
1500
1501 flex_group = ext4_flex_group(sbi, group_data[0].group);
1502 fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
1503 atomic64_add(EXT4_NUM_B2C(sbi, free_blocks),
1504 &fg->free_clusters);
1505 atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count,
1506 &fg->free_inodes);
1507 }
1508
1509 /*
1510 * Update the fs overhead information.
1511 *
1512 * For bigalloc, if the superblock already has a properly calculated
1513 * overhead, update it with a value based on numbers already computed
1514 * above for the newly allocated capacity.
1515 */
1516 if (ext4_has_feature_bigalloc(sb) && (sbi->s_overhead != 0))
1517 ext4_add_overhead(sb,
1518 EXT4_NUM_B2C(sbi, blocks_count - free_blocks));
1519 else
1520 ext4_calculate_overhead(sb);
1521 es->s_overhead_clusters = cpu_to_le32(sbi->s_overhead);
1522
1523 ext4_superblock_csum_set(sb);
1524 unlock_buffer(sbi->s_sbh);
1525 if (test_opt(sb, DEBUG))
1526 printk(KERN_DEBUG "EXT4-fs: added group %u:"
1527 "%llu blocks(%llu free %llu reserved)\n", flex_gd->count,
1528 blocks_count, free_blocks, reserved_blocks);
1529}
1530
1531/* Add a flex group to an fs. Ensure we handle all possible error conditions
1532 * _before_ we start modifying the filesystem, because we cannot abort the
1533 * transaction and not have it write the data to disk.
1534 */
1535static int ext4_flex_group_add(struct super_block *sb,
1536 struct inode *resize_inode,
1537 struct ext4_new_flex_group_data *flex_gd)
1538{
1539 struct ext4_sb_info *sbi = EXT4_SB(sb);
1540 struct ext4_super_block *es = sbi->s_es;
1541 ext4_fsblk_t o_blocks_count;
1542 ext4_grpblk_t last;
1543 ext4_group_t group;
1544 handle_t *handle;
1545 unsigned reserved_gdb;
1546 int err = 0, err2 = 0, credit;
1547
1548 BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags);
1549
1550 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
1551 o_blocks_count = ext4_blocks_count(es);
1552 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1553 BUG_ON(last);
1554
1555 err = setup_new_flex_group_blocks(sb, flex_gd);
1556 if (err)
1557 goto exit;
1558 /*
1559 * We will always be modifying at least the superblock and GDT
1560 * blocks. If we are adding a group past the last current GDT block,
1561 * we will also modify the inode and the dindirect block. If we
1562 * are adding a group with superblock/GDT backups we will also
1563 * modify each of the reserved GDT dindirect blocks.
1564 */
1565 credit = 3; /* sb, resize inode, resize inode dindirect */
1566 /* GDT blocks */
1567 credit += 1 + DIV_ROUND_UP(flex_gd->count, EXT4_DESC_PER_BLOCK(sb));
1568 credit += reserved_gdb; /* Reserved GDT dindirect blocks */
1569 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credit);
1570 if (IS_ERR(handle)) {
1571 err = PTR_ERR(handle);
1572 goto exit;
1573 }
1574
1575 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
1576 err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
1577 EXT4_JTR_NONE);
1578 if (err)
1579 goto exit_journal;
1580
1581 group = flex_gd->groups[0].group;
1582 BUG_ON(group != sbi->s_groups_count);
1583 err = ext4_add_new_descs(handle, sb, group,
1584 resize_inode, flex_gd->count);
1585 if (err)
1586 goto exit_journal;
1587
1588 err = ext4_setup_new_descs(handle, sb, flex_gd);
1589 if (err)
1590 goto exit_journal;
1591
1592 ext4_update_super(sb, flex_gd);
1593
1594 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
1595
1596exit_journal:
1597 err2 = ext4_journal_stop(handle);
1598 if (!err)
1599 err = err2;
1600
1601 if (!err) {
1602 int gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1603 int gdb_num_end = ((group + flex_gd->count - 1) /
1604 EXT4_DESC_PER_BLOCK(sb));
1605 int meta_bg = ext4_has_feature_meta_bg(sb);
1606 sector_t padding_blocks = meta_bg ? 0 : sbi->s_sbh->b_blocknr -
1607 ext4_group_first_block_no(sb, 0);
1608
1609 update_backups(sb, ext4_group_first_block_no(sb, 0),
1610 (char *)es, sizeof(struct ext4_super_block), 0);
1611 for (; gdb_num <= gdb_num_end; gdb_num++) {
1612 struct buffer_head *gdb_bh;
1613
1614 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc,
1615 gdb_num);
1616 update_backups(sb, gdb_bh->b_blocknr - padding_blocks,
1617 gdb_bh->b_data, gdb_bh->b_size, meta_bg);
1618 }
1619 }
1620exit:
1621 return err;
1622}
1623
1624static int ext4_setup_next_flex_gd(struct super_block *sb,
1625 struct ext4_new_flex_group_data *flex_gd,
1626 ext4_fsblk_t n_blocks_count)
1627{
1628 struct ext4_sb_info *sbi = EXT4_SB(sb);
1629 struct ext4_super_block *es = sbi->s_es;
1630 struct ext4_new_group_data *group_data = flex_gd->groups;
1631 ext4_fsblk_t o_blocks_count;
1632 ext4_group_t n_group;
1633 ext4_group_t group;
1634 ext4_group_t last_group;
1635 ext4_grpblk_t last;
1636 ext4_grpblk_t clusters_per_group;
1637 unsigned long i;
1638
1639 clusters_per_group = EXT4_CLUSTERS_PER_GROUP(sb);
1640
1641 o_blocks_count = ext4_blocks_count(es);
1642
1643 if (o_blocks_count == n_blocks_count)
1644 return 0;
1645
1646 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1647 BUG_ON(last);
1648 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last);
1649
1650 last_group = group | (flex_gd->resize_bg - 1);
1651 if (last_group > n_group)
1652 last_group = n_group;
1653
1654 flex_gd->count = last_group - group + 1;
1655
1656 for (i = 0; i < flex_gd->count; i++) {
1657 int overhead;
1658
1659 group_data[i].group = group + i;
1660 group_data[i].blocks_count = EXT4_BLOCKS_PER_GROUP(sb);
1661 overhead = ext4_group_overhead_blocks(sb, group + i);
1662 group_data[i].mdata_blocks = overhead;
1663 group_data[i].free_clusters_count = EXT4_CLUSTERS_PER_GROUP(sb);
1664 if (ext4_has_group_desc_csum(sb)) {
1665 flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT |
1666 EXT4_BG_INODE_UNINIT;
1667 if (!test_opt(sb, INIT_INODE_TABLE))
1668 flex_gd->bg_flags[i] |= EXT4_BG_INODE_ZEROED;
1669 } else
1670 flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED;
1671 }
1672
1673 if (last_group == n_group && ext4_has_group_desc_csum(sb))
1674 /* We need to initialize block bitmap of last group. */
1675 flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT;
1676
1677 if ((last_group == n_group) && (last != clusters_per_group - 1)) {
1678 group_data[i - 1].blocks_count = EXT4_C2B(sbi, last + 1);
1679 group_data[i - 1].free_clusters_count -= clusters_per_group -
1680 last - 1;
1681 }
1682
1683 return 1;
1684}
1685
1686/* Add group descriptor data to an existing or new group descriptor block.
1687 * Ensure we handle all possible error conditions _before_ we start modifying
1688 * the filesystem, because we cannot abort the transaction and not have it
1689 * write the data to disk.
1690 *
1691 * If we are on a GDT block boundary, we need to get the reserved GDT block.
1692 * Otherwise, we may need to add backup GDT blocks for a sparse group.
1693 *
1694 * We only need to hold the superblock lock while we are actually adding
1695 * in the new group's counts to the superblock. Prior to that we have
1696 * not really "added" the group at all. We re-check that we are still
1697 * adding in the last group in case things have changed since verifying.
1698 */
1699int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
1700{
1701 struct ext4_new_flex_group_data flex_gd;
1702 struct ext4_sb_info *sbi = EXT4_SB(sb);
1703 struct ext4_super_block *es = sbi->s_es;
1704 int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
1705 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
1706 struct inode *inode = NULL;
1707 int gdb_off;
1708 int err;
1709 __u16 bg_flags = 0;
1710
1711 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb);
1712
1713 if (gdb_off == 0 && !ext4_has_feature_sparse_super(sb)) {
1714 ext4_warning(sb, "Can't resize non-sparse filesystem further");
1715 return -EPERM;
1716 }
1717
1718 if (ext4_blocks_count(es) + input->blocks_count <
1719 ext4_blocks_count(es)) {
1720 ext4_warning(sb, "blocks_count overflow");
1721 return -EINVAL;
1722 }
1723
1724 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) <
1725 le32_to_cpu(es->s_inodes_count)) {
1726 ext4_warning(sb, "inodes_count overflow");
1727 return -EINVAL;
1728 }
1729
1730 if (reserved_gdb || gdb_off == 0) {
1731 if (!ext4_has_feature_resize_inode(sb) ||
1732 !le16_to_cpu(es->s_reserved_gdt_blocks)) {
1733 ext4_warning(sb,
1734 "No reserved GDT blocks, can't resize");
1735 return -EPERM;
1736 }
1737 inode = ext4_iget(sb, EXT4_RESIZE_INO, EXT4_IGET_SPECIAL);
1738 if (IS_ERR(inode)) {
1739 ext4_warning(sb, "Error opening resize inode");
1740 return PTR_ERR(inode);
1741 }
1742 }
1743
1744
1745 err = verify_group_input(sb, input);
1746 if (err)
1747 goto out;
1748
1749 err = ext4_alloc_flex_bg_array(sb, input->group + 1);
1750 if (err)
1751 goto out;
1752
1753 err = ext4_mb_alloc_groupinfo(sb, input->group + 1);
1754 if (err)
1755 goto out;
1756
1757 flex_gd.count = 1;
1758 flex_gd.groups = input;
1759 flex_gd.bg_flags = &bg_flags;
1760 err = ext4_flex_group_add(sb, inode, &flex_gd);
1761out:
1762 iput(inode);
1763 return err;
1764} /* ext4_group_add */
1765
1766/*
1767 * extend a group without checking assuming that checking has been done.
1768 */
1769static int ext4_group_extend_no_check(struct super_block *sb,
1770 ext4_fsblk_t o_blocks_count, ext4_grpblk_t add)
1771{
1772 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1773 handle_t *handle;
1774 int err = 0, err2;
1775
1776 /* We will update the superblock, one block bitmap, and
1777 * one group descriptor via ext4_group_add_blocks().
1778 */
1779 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, 3);
1780 if (IS_ERR(handle)) {
1781 err = PTR_ERR(handle);
1782 ext4_warning(sb, "error %d on journal start", err);
1783 return err;
1784 }
1785
1786 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
1787 err = ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh,
1788 EXT4_JTR_NONE);
1789 if (err) {
1790 ext4_warning(sb, "error %d on journal write access", err);
1791 goto errout;
1792 }
1793
1794 lock_buffer(EXT4_SB(sb)->s_sbh);
1795 ext4_blocks_count_set(es, o_blocks_count + add);
1796 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add);
1797 ext4_superblock_csum_set(sb);
1798 unlock_buffer(EXT4_SB(sb)->s_sbh);
1799 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
1800 o_blocks_count + add);
1801 /* We add the blocks to the bitmap and set the group need init bit */
1802 err = ext4_group_add_blocks(handle, sb, o_blocks_count, add);
1803 if (err)
1804 goto errout;
1805 ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
1806 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
1807 o_blocks_count + add);
1808errout:
1809 err2 = ext4_journal_stop(handle);
1810 if (err2 && !err)
1811 err = err2;
1812
1813 if (!err) {
1814 if (test_opt(sb, DEBUG))
1815 printk(KERN_DEBUG "EXT4-fs: extended group to %llu "
1816 "blocks\n", ext4_blocks_count(es));
1817 update_backups(sb, ext4_group_first_block_no(sb, 0),
1818 (char *)es, sizeof(struct ext4_super_block), 0);
1819 }
1820 return err;
1821}
1822
1823/*
1824 * Extend the filesystem to the new number of blocks specified. This entry
1825 * point is only used to extend the current filesystem to the end of the last
1826 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>"
1827 * for emergencies (because it has no dependencies on reserved blocks).
1828 *
1829 * If we _really_ wanted, we could use default values to call ext4_group_add()
1830 * allow the "remount" trick to work for arbitrary resizing, assuming enough
1831 * GDT blocks are reserved to grow to the desired size.
1832 */
1833int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
1834 ext4_fsblk_t n_blocks_count)
1835{
1836 ext4_fsblk_t o_blocks_count;
1837 ext4_grpblk_t last;
1838 ext4_grpblk_t add;
1839 struct buffer_head *bh;
1840 ext4_group_t group;
1841
1842 o_blocks_count = ext4_blocks_count(es);
1843
1844 if (test_opt(sb, DEBUG))
1845 ext4_msg(sb, KERN_DEBUG,
1846 "extending last group from %llu to %llu blocks",
1847 o_blocks_count, n_blocks_count);
1848
1849 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
1850 return 0;
1851
1852 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1853 ext4_msg(sb, KERN_ERR,
1854 "filesystem too large to resize to %llu blocks safely",
1855 n_blocks_count);
1856 return -EINVAL;
1857 }
1858
1859 if (n_blocks_count < o_blocks_count) {
1860 ext4_warning(sb, "can't shrink FS - resize aborted");
1861 return -EINVAL;
1862 }
1863
1864 /* Handle the remaining blocks in the last group only. */
1865 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1866
1867 if (last == 0) {
1868 ext4_warning(sb, "need to use ext2online to resize further");
1869 return -EPERM;
1870 }
1871
1872 add = EXT4_BLOCKS_PER_GROUP(sb) - last;
1873
1874 if (o_blocks_count + add < o_blocks_count) {
1875 ext4_warning(sb, "blocks_count overflow");
1876 return -EINVAL;
1877 }
1878
1879 if (o_blocks_count + add > n_blocks_count)
1880 add = n_blocks_count - o_blocks_count;
1881
1882 if (o_blocks_count + add < n_blocks_count)
1883 ext4_warning(sb, "will only finish group (%llu blocks, %u new)",
1884 o_blocks_count + add, add);
1885
1886 /* See if the device is actually as big as what was requested */
1887 bh = ext4_sb_bread(sb, o_blocks_count + add - 1, 0);
1888 if (IS_ERR(bh)) {
1889 ext4_warning(sb, "can't read last block, resize aborted");
1890 return -ENOSPC;
1891 }
1892 brelse(bh);
1893
1894 return ext4_group_extend_no_check(sb, o_blocks_count, add);
1895} /* ext4_group_extend */
1896
1897
1898static int num_desc_blocks(struct super_block *sb, ext4_group_t groups)
1899{
1900 return (groups + EXT4_DESC_PER_BLOCK(sb) - 1) / EXT4_DESC_PER_BLOCK(sb);
1901}
1902
1903/*
1904 * Release the resize inode and drop the resize_inode feature if there
1905 * are no more reserved gdt blocks, and then convert the file system
1906 * to enable meta_bg
1907 */
1908static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode)
1909{
1910 handle_t *handle;
1911 struct ext4_sb_info *sbi = EXT4_SB(sb);
1912 struct ext4_super_block *es = sbi->s_es;
1913 struct ext4_inode_info *ei = EXT4_I(inode);
1914 ext4_fsblk_t nr;
1915 int i, ret, err = 0;
1916 int credits = 1;
1917
1918 ext4_msg(sb, KERN_INFO, "Converting file system to meta_bg");
1919 if (inode) {
1920 if (es->s_reserved_gdt_blocks) {
1921 ext4_error(sb, "Unexpected non-zero "
1922 "s_reserved_gdt_blocks");
1923 return -EPERM;
1924 }
1925
1926 /* Do a quick sanity check of the resize inode */
1927 if (inode->i_blocks != 1 << (inode->i_blkbits -
1928 (9 - sbi->s_cluster_bits)))
1929 goto invalid_resize_inode;
1930 for (i = 0; i < EXT4_N_BLOCKS; i++) {
1931 if (i == EXT4_DIND_BLOCK) {
1932 if (ei->i_data[i])
1933 continue;
1934 else
1935 goto invalid_resize_inode;
1936 }
1937 if (ei->i_data[i])
1938 goto invalid_resize_inode;
1939 }
1940 credits += 3; /* block bitmap, bg descriptor, resize inode */
1941 }
1942
1943 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credits);
1944 if (IS_ERR(handle))
1945 return PTR_ERR(handle);
1946
1947 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
1948 err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
1949 EXT4_JTR_NONE);
1950 if (err)
1951 goto errout;
1952
1953 lock_buffer(sbi->s_sbh);
1954 ext4_clear_feature_resize_inode(sb);
1955 ext4_set_feature_meta_bg(sb);
1956 sbi->s_es->s_first_meta_bg =
1957 cpu_to_le32(num_desc_blocks(sb, sbi->s_groups_count));
1958 ext4_superblock_csum_set(sb);
1959 unlock_buffer(sbi->s_sbh);
1960
1961 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
1962 if (err) {
1963 ext4_std_error(sb, err);
1964 goto errout;
1965 }
1966
1967 if (inode) {
1968 nr = le32_to_cpu(ei->i_data[EXT4_DIND_BLOCK]);
1969 ext4_free_blocks(handle, inode, NULL, nr, 1,
1970 EXT4_FREE_BLOCKS_METADATA |
1971 EXT4_FREE_BLOCKS_FORGET);
1972 ei->i_data[EXT4_DIND_BLOCK] = 0;
1973 inode->i_blocks = 0;
1974
1975 err = ext4_mark_inode_dirty(handle, inode);
1976 if (err)
1977 ext4_std_error(sb, err);
1978 }
1979
1980errout:
1981 ret = ext4_journal_stop(handle);
1982 return err ? err : ret;
1983
1984invalid_resize_inode:
1985 ext4_error(sb, "corrupted/inconsistent resize inode");
1986 return -EINVAL;
1987}
1988
1989/*
1990 * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count
1991 *
1992 * @sb: super block of the fs to be resized
1993 * @n_blocks_count: the number of blocks resides in the resized fs
1994 */
1995int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
1996{
1997 struct ext4_new_flex_group_data *flex_gd = NULL;
1998 struct ext4_sb_info *sbi = EXT4_SB(sb);
1999 struct ext4_super_block *es = sbi->s_es;
2000 struct buffer_head *bh;
2001 struct inode *resize_inode = NULL;
2002 ext4_grpblk_t add, offset;
2003 unsigned long n_desc_blocks;
2004 unsigned long o_desc_blocks;
2005 ext4_group_t o_group;
2006 ext4_group_t n_group;
2007 ext4_fsblk_t o_blocks_count;
2008 ext4_fsblk_t n_blocks_count_retry = 0;
2009 unsigned long last_update_time = 0;
2010 int err = 0;
2011 int meta_bg;
2012 unsigned int flexbg_size = ext4_flex_bg_size(sbi);
2013
2014 /* See if the device is actually as big as what was requested */
2015 bh = ext4_sb_bread(sb, n_blocks_count - 1, 0);
2016 if (IS_ERR(bh)) {
2017 ext4_warning(sb, "can't read last block, resize aborted");
2018 return -ENOSPC;
2019 }
2020 brelse(bh);
2021
2022 /*
2023 * For bigalloc, trim the requested size to the nearest cluster
2024 * boundary to avoid creating an unusable filesystem. We do this
2025 * silently, instead of returning an error, to avoid breaking
2026 * callers that blindly resize the filesystem to the full size of
2027 * the underlying block device.
2028 */
2029 if (ext4_has_feature_bigalloc(sb))
2030 n_blocks_count &= ~((1 << EXT4_CLUSTER_BITS(sb)) - 1);
2031
2032retry:
2033 o_blocks_count = ext4_blocks_count(es);
2034
2035 ext4_msg(sb, KERN_INFO, "resizing filesystem from %llu "
2036 "to %llu blocks", o_blocks_count, n_blocks_count);
2037
2038 if (n_blocks_count < o_blocks_count) {
2039 /* On-line shrinking not supported */
2040 ext4_warning(sb, "can't shrink FS - resize aborted");
2041 return -EINVAL;
2042 }
2043
2044 if (n_blocks_count == o_blocks_count)
2045 /* Nothing need to do */
2046 return 0;
2047
2048 n_group = ext4_get_group_number(sb, n_blocks_count - 1);
2049 if (n_group >= (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) {
2050 ext4_warning(sb, "resize would cause inodes_count overflow");
2051 return -EINVAL;
2052 }
2053 ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset);
2054
2055 n_desc_blocks = num_desc_blocks(sb, n_group + 1);
2056 o_desc_blocks = num_desc_blocks(sb, sbi->s_groups_count);
2057
2058 meta_bg = ext4_has_feature_meta_bg(sb);
2059
2060 if (ext4_has_feature_resize_inode(sb)) {
2061 if (meta_bg) {
2062 ext4_error(sb, "resize_inode and meta_bg enabled "
2063 "simultaneously");
2064 return -EINVAL;
2065 }
2066 if (n_desc_blocks > o_desc_blocks +
2067 le16_to_cpu(es->s_reserved_gdt_blocks)) {
2068 n_blocks_count_retry = n_blocks_count;
2069 n_desc_blocks = o_desc_blocks +
2070 le16_to_cpu(es->s_reserved_gdt_blocks);
2071 n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb);
2072 n_blocks_count = (ext4_fsblk_t)n_group *
2073 EXT4_BLOCKS_PER_GROUP(sb) +
2074 le32_to_cpu(es->s_first_data_block);
2075 n_group--; /* set to last group number */
2076 }
2077
2078 if (!resize_inode)
2079 resize_inode = ext4_iget(sb, EXT4_RESIZE_INO,
2080 EXT4_IGET_SPECIAL);
2081 if (IS_ERR(resize_inode)) {
2082 ext4_warning(sb, "Error opening resize inode");
2083 return PTR_ERR(resize_inode);
2084 }
2085 }
2086
2087 if ((!resize_inode && !meta_bg) || n_blocks_count == o_blocks_count) {
2088 err = ext4_convert_meta_bg(sb, resize_inode);
2089 if (err)
2090 goto out;
2091 if (resize_inode) {
2092 iput(resize_inode);
2093 resize_inode = NULL;
2094 }
2095 if (n_blocks_count_retry) {
2096 n_blocks_count = n_blocks_count_retry;
2097 n_blocks_count_retry = 0;
2098 goto retry;
2099 }
2100 }
2101
2102 /*
2103 * Make sure the last group has enough space so that it's
2104 * guaranteed to have enough space for all metadata blocks
2105 * that it might need to hold. (We might not need to store
2106 * the inode table blocks in the last block group, but there
2107 * will be cases where this might be needed.)
2108 */
2109 if ((ext4_group_first_block_no(sb, n_group) +
2110 ext4_group_overhead_blocks(sb, n_group) + 2 +
2111 sbi->s_itb_per_group + sbi->s_cluster_ratio) >= n_blocks_count) {
2112 n_blocks_count = ext4_group_first_block_no(sb, n_group);
2113 n_group--;
2114 n_blocks_count_retry = 0;
2115 if (resize_inode) {
2116 iput(resize_inode);
2117 resize_inode = NULL;
2118 }
2119 goto retry;
2120 }
2121
2122 /* extend the last group */
2123 if (n_group == o_group)
2124 add = n_blocks_count - o_blocks_count;
2125 else
2126 add = EXT4_C2B(sbi, EXT4_CLUSTERS_PER_GROUP(sb) - (offset + 1));
2127 if (add > 0) {
2128 err = ext4_group_extend_no_check(sb, o_blocks_count, add);
2129 if (err)
2130 goto out;
2131 }
2132
2133 if (ext4_blocks_count(es) == n_blocks_count && n_blocks_count_retry == 0)
2134 goto out;
2135
2136 err = ext4_alloc_flex_bg_array(sb, n_group + 1);
2137 if (err)
2138 goto out;
2139
2140 err = ext4_mb_alloc_groupinfo(sb, n_group + 1);
2141 if (err)
2142 goto out;
2143
2144 flex_gd = alloc_flex_gd(flexbg_size, o_group, n_group);
2145 if (flex_gd == NULL) {
2146 err = -ENOMEM;
2147 goto out;
2148 }
2149
2150 /* Add flex groups. Note that a regular group is a
2151 * flex group with 1 group.
2152 */
2153 while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count)) {
2154 if (time_is_before_jiffies(last_update_time + HZ * 10)) {
2155 if (last_update_time)
2156 ext4_msg(sb, KERN_INFO,
2157 "resized to %llu blocks",
2158 ext4_blocks_count(es));
2159 last_update_time = jiffies;
2160 }
2161 if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0)
2162 break;
2163 err = ext4_flex_group_add(sb, resize_inode, flex_gd);
2164 if (unlikely(err))
2165 break;
2166 }
2167
2168 if (!err && n_blocks_count_retry) {
2169 n_blocks_count = n_blocks_count_retry;
2170 n_blocks_count_retry = 0;
2171 free_flex_gd(flex_gd);
2172 flex_gd = NULL;
2173 if (resize_inode) {
2174 iput(resize_inode);
2175 resize_inode = NULL;
2176 }
2177 goto retry;
2178 }
2179
2180out:
2181 if (flex_gd)
2182 free_flex_gd(flex_gd);
2183 if (resize_inode != NULL)
2184 iput(resize_inode);
2185 if (err)
2186 ext4_warning(sb, "error (%d) occurred during "
2187 "file system resize", err);
2188 ext4_msg(sb, KERN_INFO, "resized filesystem to %llu",
2189 ext4_blocks_count(es));
2190 return err;
2191}