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ipv6: addrconf: break critical section in addrconf_verify_rtnl()
[linux/fpc-iii.git] / fs / ext4 / resize.c
blob50443bda8e98fb9c5e6fa3f2433e95b1f327e7c3
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/ext4/resize.c
4 *
5 * Support for resizing an ext4 filesystem while it is mounted.
6 *
7 * Copyright (C) 2001, 2002 Andreas Dilger <adilger@clusterfs.com>
8 *
9 * This could probably be made into a module, because it is not often in use.
10 */
11
12
13 #define EXT4FS_DEBUG
14
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17
18 #include "ext4_jbd2.h"
19
20 int ext4_resize_begin(struct super_block *sb)
21 {
22 int ret = 0;
23
24 if (!capable(CAP_SYS_RESOURCE))
25 return -EPERM;
26
27 /*
28 * If we are not using the primary superblock/GDT copy don't resize,
29 * because the user tools have no way of handling this. Probably a
30 * bad time to do it anyways.
31 */
32 if (EXT4_SB(sb)->s_sbh->b_blocknr !=
33 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
34 ext4_warning(sb, "won't resize using backup superblock at %llu",
35 (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
36 return -EPERM;
37 }
38
39 /*
40 * We are not allowed to do online-resizing on a filesystem mounted
41 * with error, because it can destroy the filesystem easily.
42 */
43 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
44 ext4_warning(sb, "There are errors in the filesystem, "
45 "so online resizing is not allowed");
46 return -EPERM;
47 }
48
49 if (test_and_set_bit_lock(EXT4_FLAGS_RESIZING,
50 &EXT4_SB(sb)->s_ext4_flags))
51 ret = -EBUSY;
52
53 return ret;
54 }
55
56 void ext4_resize_end(struct super_block *sb)
57 {
58 clear_bit_unlock(EXT4_FLAGS_RESIZING, &EXT4_SB(sb)->s_ext4_flags);
59 smp_mb__after_atomic();
60 }
61
62 static ext4_group_t ext4_meta_bg_first_group(struct super_block *sb,
63 ext4_group_t group) {
64 return (group >> EXT4_DESC_PER_BLOCK_BITS(sb)) <<
65 EXT4_DESC_PER_BLOCK_BITS(sb);
66 }
67
68 static ext4_fsblk_t ext4_meta_bg_first_block_no(struct super_block *sb,
69 ext4_group_t group) {
70 group = ext4_meta_bg_first_group(sb, group);
71 return ext4_group_first_block_no(sb, group);
72 }
73
74 static ext4_grpblk_t ext4_group_overhead_blocks(struct super_block *sb,
75 ext4_group_t group) {
76 ext4_grpblk_t overhead;
77 overhead = ext4_bg_num_gdb(sb, group);
78 if (ext4_bg_has_super(sb, group))
79 overhead += 1 +
80 le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
81 return overhead;
82 }
83
84 #define outside(b, first, last) ((b) < (first) || (b) >= (last))
85 #define inside(b, first, last) ((b) >= (first) && (b) < (last))
86
87 static int verify_group_input(struct super_block *sb,
88 struct ext4_new_group_data *input)
89 {
90 struct ext4_sb_info *sbi = EXT4_SB(sb);
91 struct ext4_super_block *es = sbi->s_es;
92 ext4_fsblk_t start = ext4_blocks_count(es);
93 ext4_fsblk_t end = start + input->blocks_count;
94 ext4_group_t group = input->group;
95 ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
96 unsigned overhead;
97 ext4_fsblk_t metaend;
98 struct buffer_head *bh = NULL;
99 ext4_grpblk_t free_blocks_count, offset;
100 int err = -EINVAL;
101
102 if (group != sbi->s_groups_count) {
103 ext4_warning(sb, "Cannot add at group %u (only %u groups)",
104 input->group, sbi->s_groups_count);
105 return -EINVAL;
106 }
107
108 overhead = ext4_group_overhead_blocks(sb, group);
109 metaend = start + overhead;
110 input->free_clusters_count = free_blocks_count =
111 input->blocks_count - 2 - overhead - sbi->s_itb_per_group;
112
113 if (test_opt(sb, DEBUG))
114 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks "
115 "(%d free, %u reserved)\n",
116 ext4_bg_has_super(sb, input->group) ? "normal" :
117 "no-super", input->group, input->blocks_count,
118 free_blocks_count, input->reserved_blocks);
119
120 ext4_get_group_no_and_offset(sb, start, NULL, &offset);
121 if (offset != 0)
122 ext4_warning(sb, "Last group not full");
123 else if (input->reserved_blocks > input->blocks_count / 5)
124 ext4_warning(sb, "Reserved blocks too high (%u)",
125 input->reserved_blocks);
126 else if (free_blocks_count < 0)
127 ext4_warning(sb, "Bad blocks count %u",
128 input->blocks_count);
129 else if (!(bh = sb_bread(sb, end - 1)))
130 ext4_warning(sb, "Cannot read last block (%llu)",
131 end - 1);
132 else if (outside(input->block_bitmap, start, end))
133 ext4_warning(sb, "Block bitmap not in group (block %llu)",
134 (unsigned long long)input->block_bitmap);
135 else if (outside(input->inode_bitmap, start, end))
136 ext4_warning(sb, "Inode bitmap not in group (block %llu)",
137 (unsigned long long)input->inode_bitmap);
138 else if (outside(input->inode_table, start, end) ||
139 outside(itend - 1, start, end))
140 ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)",
141 (unsigned long long)input->inode_table, itend - 1);
142 else if (input->inode_bitmap == input->block_bitmap)
143 ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)",
144 (unsigned long long)input->block_bitmap);
145 else if (inside(input->block_bitmap, input->inode_table, itend))
146 ext4_warning(sb, "Block bitmap (%llu) in inode table "
147 "(%llu-%llu)",
148 (unsigned long long)input->block_bitmap,
149 (unsigned long long)input->inode_table, itend - 1);
150 else if (inside(input->inode_bitmap, input->inode_table, itend))
151 ext4_warning(sb, "Inode bitmap (%llu) in inode table "
152 "(%llu-%llu)",
153 (unsigned long long)input->inode_bitmap,
154 (unsigned long long)input->inode_table, itend - 1);
155 else if (inside(input->block_bitmap, start, metaend))
156 ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)",
157 (unsigned long long)input->block_bitmap,
158 start, metaend - 1);
159 else if (inside(input->inode_bitmap, start, metaend))
160 ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)",
161 (unsigned long long)input->inode_bitmap,
162 start, metaend - 1);
163 else if (inside(input->inode_table, start, metaend) ||
164 inside(itend - 1, start, metaend))
165 ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table "
166 "(%llu-%llu)",
167 (unsigned long long)input->inode_table,
168 itend - 1, start, metaend - 1);
169 else
170 err = 0;
171 brelse(bh);
172
173 return err;
174 }
175
176 /*
177 * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex
178 * group each time.
179 */
180 struct ext4_new_flex_group_data {
181 struct ext4_new_group_data *groups; /* new_group_data for groups
182 in the flex group */
183 __u16 *bg_flags; /* block group flags of groups
184 in @groups */
185 ext4_group_t count; /* number of groups in @groups
186 */
187 };
188
189 /*
190 * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of
191 * @flexbg_size.
192 *
193 * Returns NULL on failure otherwise address of the allocated structure.
194 */
195 static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size)
196 {
197 struct ext4_new_flex_group_data *flex_gd;
198
199 flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS);
200 if (flex_gd == NULL)
201 goto out3;
202
203 if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_group_data))
204 goto out2;
205 flex_gd->count = flexbg_size;
206
207 flex_gd->groups = kmalloc(sizeof(struct ext4_new_group_data) *
208 flexbg_size, GFP_NOFS);
209 if (flex_gd->groups == NULL)
210 goto out2;
211
212 flex_gd->bg_flags = kmalloc(flexbg_size * sizeof(__u16), GFP_NOFS);
213 if (flex_gd->bg_flags == NULL)
214 goto out1;
215
216 return flex_gd;
217
218 out1:
219 kfree(flex_gd->groups);
220 out2:
221 kfree(flex_gd);
222 out3:
223 return NULL;
224 }
225
226 static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd)
227 {
228 kfree(flex_gd->bg_flags);
229 kfree(flex_gd->groups);
230 kfree(flex_gd);
231 }
232
233 /*
234 * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps
235 * and inode tables for a flex group.
236 *
237 * This function is used by 64bit-resize. Note that this function allocates
238 * group tables from the 1st group of groups contained by @flexgd, which may
239 * be a partial of a flex group.
240 *
241 * @sb: super block of fs to which the groups belongs
242 *
243 * Returns 0 on a successful allocation of the metadata blocks in the
244 * block group.
245 */
246 static int ext4_alloc_group_tables(struct super_block *sb,
247 struct ext4_new_flex_group_data *flex_gd,
248 int flexbg_size)
249 {
250 struct ext4_new_group_data *group_data = flex_gd->groups;
251 ext4_fsblk_t start_blk;
252 ext4_fsblk_t last_blk;
253 ext4_group_t src_group;
254 ext4_group_t bb_index = 0;
255 ext4_group_t ib_index = 0;
256 ext4_group_t it_index = 0;
257 ext4_group_t group;
258 ext4_group_t last_group;
259 unsigned overhead;
260 __u16 uninit_mask = (flexbg_size > 1) ? ~EXT4_BG_BLOCK_UNINIT : ~0;
261 int i;
262
263 BUG_ON(flex_gd->count == 0 || group_data == NULL);
264
265 src_group = group_data[0].group;
266 last_group = src_group + flex_gd->count - 1;
267
268 BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) !=
269 (last_group & ~(flexbg_size - 1))));
270 next_group:
271 group = group_data[0].group;
272 if (src_group >= group_data[0].group + flex_gd->count)
273 return -ENOSPC;
274 start_blk = ext4_group_first_block_no(sb, src_group);
275 last_blk = start_blk + group_data[src_group - group].blocks_count;
276
277 overhead = ext4_group_overhead_blocks(sb, src_group);
278
279 start_blk += overhead;
280
281 /* We collect contiguous blocks as much as possible. */
282 src_group++;
283 for (; src_group <= last_group; src_group++) {
284 overhead = ext4_group_overhead_blocks(sb, src_group);
285 if (overhead == 0)
286 last_blk += group_data[src_group - group].blocks_count;
287 else
288 break;
289 }
290
291 /* Allocate block bitmaps */
292 for (; bb_index < flex_gd->count; bb_index++) {
293 if (start_blk >= last_blk)
294 goto next_group;
295 group_data[bb_index].block_bitmap = start_blk++;
296 group = ext4_get_group_number(sb, start_blk - 1);
297 group -= group_data[0].group;
298 group_data[group].mdata_blocks++;
299 flex_gd->bg_flags[group] &= uninit_mask;
300 }
301
302 /* Allocate inode bitmaps */
303 for (; ib_index < flex_gd->count; ib_index++) {
304 if (start_blk >= last_blk)
305 goto next_group;
306 group_data[ib_index].inode_bitmap = start_blk++;
307 group = ext4_get_group_number(sb, start_blk - 1);
308 group -= group_data[0].group;
309 group_data[group].mdata_blocks++;
310 flex_gd->bg_flags[group] &= uninit_mask;
311 }
312
313 /* Allocate inode tables */
314 for (; it_index < flex_gd->count; it_index++) {
315 unsigned int itb = EXT4_SB(sb)->s_itb_per_group;
316 ext4_fsblk_t next_group_start;
317
318 if (start_blk + itb > last_blk)
319 goto next_group;
320 group_data[it_index].inode_table = start_blk;
321 group = ext4_get_group_number(sb, start_blk);
322 next_group_start = ext4_group_first_block_no(sb, group + 1);
323 group -= group_data[0].group;
324
325 if (start_blk + itb > next_group_start) {
326 flex_gd->bg_flags[group + 1] &= uninit_mask;
327 overhead = start_blk + itb - next_group_start;
328 group_data[group + 1].mdata_blocks += overhead;
329 itb -= overhead;
330 }
331
332 group_data[group].mdata_blocks += itb;
333 flex_gd->bg_flags[group] &= uninit_mask;
334 start_blk += EXT4_SB(sb)->s_itb_per_group;
335 }
336
337 /* Update free clusters count to exclude metadata blocks */
338 for (i = 0; i < flex_gd->count; i++) {
339 group_data[i].free_clusters_count -=
340 EXT4_NUM_B2C(EXT4_SB(sb),
341 group_data[i].mdata_blocks);
342 }
343
344 if (test_opt(sb, DEBUG)) {
345 int i;
346 group = group_data[0].group;
347
348 printk(KERN_DEBUG "EXT4-fs: adding a flex group with "
349 "%d groups, flexbg size is %d:\n", flex_gd->count,
350 flexbg_size);
351
352 for (i = 0; i < flex_gd->count; i++) {
353 ext4_debug(
354 "adding %s group %u: %u blocks (%d free, %d mdata blocks)\n",
355 ext4_bg_has_super(sb, group + i) ? "normal" :
356 "no-super", group + i,
357 group_data[i].blocks_count,
358 group_data[i].free_clusters_count,
359 group_data[i].mdata_blocks);
360 }
361 }
362 return 0;
363 }
364
365 static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
366 ext4_fsblk_t blk)
367 {
368 struct buffer_head *bh;
369 int err;
370
371 bh = sb_getblk(sb, blk);
372 if (unlikely(!bh))
373 return ERR_PTR(-ENOMEM);
374 BUFFER_TRACE(bh, "get_write_access");
375 if ((err = ext4_journal_get_write_access(handle, bh))) {
376 brelse(bh);
377 bh = ERR_PTR(err);
378 } else {
379 memset(bh->b_data, 0, sb->s_blocksize);
380 set_buffer_uptodate(bh);
381 }
382
383 return bh;
384 }
385
386 /*
387 * If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA.
388 * If that fails, restart the transaction & regain write access for the
389 * buffer head which is used for block_bitmap modifications.
390 */
391 static int extend_or_restart_transaction(handle_t *handle, int thresh)
392 {
393 int err;
394
395 if (ext4_handle_has_enough_credits(handle, thresh))
396 return 0;
397
398 err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA);
399 if (err < 0)
400 return err;
401 if (err) {
402 err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA);
403 if (err)
404 return err;
405 }
406
407 return 0;
408 }
409
410 /*
411 * set_flexbg_block_bitmap() mark clusters [@first_cluster, @last_cluster] used.
412 *
413 * Helper function for ext4_setup_new_group_blocks() which set .
414 *
415 * @sb: super block
416 * @handle: journal handle
417 * @flex_gd: flex group data
418 */
419 static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle,
420 struct ext4_new_flex_group_data *flex_gd,
421 ext4_fsblk_t first_cluster, ext4_fsblk_t last_cluster)
422 {
423 struct ext4_sb_info *sbi = EXT4_SB(sb);
424 ext4_group_t count = last_cluster - first_cluster + 1;
425 ext4_group_t count2;
426
427 ext4_debug("mark clusters [%llu-%llu] used\n", first_cluster,
428 last_cluster);
429 for (count2 = count; count > 0;
430 count -= count2, first_cluster += count2) {
431 ext4_fsblk_t start;
432 struct buffer_head *bh;
433 ext4_group_t group;
434 int err;
435
436 group = ext4_get_group_number(sb, EXT4_C2B(sbi, first_cluster));
437 start = EXT4_B2C(sbi, ext4_group_first_block_no(sb, group));
438 group -= flex_gd->groups[0].group;
439
440 count2 = EXT4_CLUSTERS_PER_GROUP(sb) - (first_cluster - start);
441 if (count2 > count)
442 count2 = count;
443
444 if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) {
445 BUG_ON(flex_gd->count > 1);
446 continue;
447 }
448
449 err = extend_or_restart_transaction(handle, 1);
450 if (err)
451 return err;
452
453 bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap);
454 if (unlikely(!bh))
455 return -ENOMEM;
456
457 BUFFER_TRACE(bh, "get_write_access");
458 err = ext4_journal_get_write_access(handle, bh);
459 if (err)
460 return err;
461 ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n",
462 first_cluster, first_cluster - start, count2);
463 ext4_set_bits(bh->b_data, first_cluster - start, count2);
464
465 err = ext4_handle_dirty_metadata(handle, NULL, bh);
466 if (unlikely(err))
467 return err;
468 brelse(bh);
469 }
470
471 return 0;
472 }
473
474 /*
475 * Set up the block and inode bitmaps, and the inode table for the new groups.
476 * This doesn't need to be part of the main transaction, since we are only
477 * changing blocks outside the actual filesystem. We still do journaling to
478 * ensure the recovery is correct in case of a failure just after resize.
479 * If any part of this fails, we simply abort the resize.
480 *
481 * setup_new_flex_group_blocks handles a flex group as follow:
482 * 1. copy super block and GDT, and initialize group tables if necessary.
483 * In this step, we only set bits in blocks bitmaps for blocks taken by
484 * super block and GDT.
485 * 2. allocate group tables in block bitmaps, that is, set bits in block
486 * bitmap for blocks taken by group tables.
487 */
488 static int setup_new_flex_group_blocks(struct super_block *sb,
489 struct ext4_new_flex_group_data *flex_gd)
490 {
491 int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group};
492 ext4_fsblk_t start;
493 ext4_fsblk_t block;
494 struct ext4_sb_info *sbi = EXT4_SB(sb);
495 struct ext4_super_block *es = sbi->s_es;
496 struct ext4_new_group_data *group_data = flex_gd->groups;
497 __u16 *bg_flags = flex_gd->bg_flags;
498 handle_t *handle;
499 ext4_group_t group, count;
500 struct buffer_head *bh = NULL;
501 int reserved_gdb, i, j, err = 0, err2;
502 int meta_bg;
503
504 BUG_ON(!flex_gd->count || !group_data ||
505 group_data[0].group != sbi->s_groups_count);
506
507 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
508 meta_bg = ext4_has_feature_meta_bg(sb);
509
510 /* This transaction may be extended/restarted along the way */
511 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA);
512 if (IS_ERR(handle))
513 return PTR_ERR(handle);
514
515 group = group_data[0].group;
516 for (i = 0; i < flex_gd->count; i++, group++) {
517 unsigned long gdblocks;
518 ext4_grpblk_t overhead;
519
520 gdblocks = ext4_bg_num_gdb(sb, group);
521 start = ext4_group_first_block_no(sb, group);
522
523 if (meta_bg == 0 && !ext4_bg_has_super(sb, group))
524 goto handle_itb;
525
526 if (meta_bg == 1) {
527 ext4_group_t first_group;
528 first_group = ext4_meta_bg_first_group(sb, group);
529 if (first_group != group + 1 &&
530 first_group != group + EXT4_DESC_PER_BLOCK(sb) - 1)
531 goto handle_itb;
532 }
533
534 block = start + ext4_bg_has_super(sb, group);
535 /* Copy all of the GDT blocks into the backup in this group */
536 for (j = 0; j < gdblocks; j++, block++) {
537 struct buffer_head *gdb;
538
539 ext4_debug("update backup group %#04llx\n", block);
540 err = extend_or_restart_transaction(handle, 1);
541 if (err)
542 goto out;
543
544 gdb = sb_getblk(sb, block);
545 if (unlikely(!gdb)) {
546 err = -ENOMEM;
547 goto out;
548 }
549
550 BUFFER_TRACE(gdb, "get_write_access");
551 err = ext4_journal_get_write_access(handle, gdb);
552 if (err) {
553 brelse(gdb);
554 goto out;
555 }
556 memcpy(gdb->b_data, sbi->s_group_desc[j]->b_data,
557 gdb->b_size);
558 set_buffer_uptodate(gdb);
559
560 err = ext4_handle_dirty_metadata(handle, NULL, gdb);
561 if (unlikely(err)) {
562 brelse(gdb);
563 goto out;
564 }
565 brelse(gdb);
566 }
567
568 /* Zero out all of the reserved backup group descriptor
569 * table blocks
570 */
571 if (ext4_bg_has_super(sb, group)) {
572 err = sb_issue_zeroout(sb, gdblocks + start + 1,
573 reserved_gdb, GFP_NOFS);
574 if (err)
575 goto out;
576 }
577
578 handle_itb:
579 /* Initialize group tables of the grop @group */
580 if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED))
581 goto handle_bb;
582
583 /* Zero out all of the inode table blocks */
584 block = group_data[i].inode_table;
585 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n",
586 block, sbi->s_itb_per_group);
587 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group,
588 GFP_NOFS);
589 if (err)
590 goto out;
591
592 handle_bb:
593 if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT)
594 goto handle_ib;
595
596 /* Initialize block bitmap of the @group */
597 block = group_data[i].block_bitmap;
598 err = extend_or_restart_transaction(handle, 1);
599 if (err)
600 goto out;
601
602 bh = bclean(handle, sb, block);
603 if (IS_ERR(bh)) {
604 err = PTR_ERR(bh);
605 bh = NULL;
606 goto out;
607 }
608 overhead = ext4_group_overhead_blocks(sb, group);
609 if (overhead != 0) {
610 ext4_debug("mark backup superblock %#04llx (+0)\n",
611 start);
612 ext4_set_bits(bh->b_data, 0,
613 EXT4_NUM_B2C(sbi, overhead));
614 }
615 ext4_mark_bitmap_end(EXT4_B2C(sbi, group_data[i].blocks_count),
616 sb->s_blocksize * 8, bh->b_data);
617 err = ext4_handle_dirty_metadata(handle, NULL, bh);
618 if (err)
619 goto out;
620 brelse(bh);
621
622 handle_ib:
623 if (bg_flags[i] & EXT4_BG_INODE_UNINIT)
624 continue;
625
626 /* Initialize inode bitmap of the @group */
627 block = group_data[i].inode_bitmap;
628 err = extend_or_restart_transaction(handle, 1);
629 if (err)
630 goto out;
631 /* Mark unused entries in inode bitmap used */
632 bh = bclean(handle, sb, block);
633 if (IS_ERR(bh)) {
634 err = PTR_ERR(bh);
635 bh = NULL;
636 goto out;
637 }
638
639 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
640 sb->s_blocksize * 8, bh->b_data);
641 err = ext4_handle_dirty_metadata(handle, NULL, bh);
642 if (err)
643 goto out;
644 brelse(bh);
645 }
646 bh = NULL;
647
648 /* Mark group tables in block bitmap */
649 for (j = 0; j < GROUP_TABLE_COUNT; j++) {
650 count = group_table_count[j];
651 start = (&group_data[0].block_bitmap)[j];
652 block = start;
653 for (i = 1; i < flex_gd->count; i++) {
654 block += group_table_count[j];
655 if (block == (&group_data[i].block_bitmap)[j]) {
656 count += group_table_count[j];
657 continue;
658 }
659 err = set_flexbg_block_bitmap(sb, handle,
660 flex_gd,
661 EXT4_B2C(sbi, start),
662 EXT4_B2C(sbi,
663 start + count
664 - 1));
665 if (err)
666 goto out;
667 count = group_table_count[j];
668 start = (&group_data[i].block_bitmap)[j];
669 block = start;
670 }
671
672 if (count) {
673 err = set_flexbg_block_bitmap(sb, handle,
674 flex_gd,
675 EXT4_B2C(sbi, start),
676 EXT4_B2C(sbi,
677 start + count
678 - 1));
679 if (err)
680 goto out;
681 }
682 }
683
684 out:
685 brelse(bh);
686 err2 = ext4_journal_stop(handle);
687 if (err2 && !err)
688 err = err2;
689
690 return err;
691 }
692
693 /*
694 * Iterate through the groups which hold BACKUP superblock/GDT copies in an
695 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
696 * calling this for the first time. In a sparse filesystem it will be the
697 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
698 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
699 */
700 static unsigned ext4_list_backups(struct super_block *sb, unsigned *three,
701 unsigned *five, unsigned *seven)
702 {
703 unsigned *min = three;
704 int mult = 3;
705 unsigned ret;
706
707 if (!ext4_has_feature_sparse_super(sb)) {
708 ret = *min;
709 *min += 1;
710 return ret;
711 }
712
713 if (*five < *min) {
714 min = five;
715 mult = 5;
716 }
717 if (*seven < *min) {
718 min = seven;
719 mult = 7;
720 }
721
722 ret = *min;
723 *min *= mult;
724
725 return ret;
726 }
727
728 /*
729 * Check that all of the backup GDT blocks are held in the primary GDT block.
730 * It is assumed that they are stored in group order. Returns the number of
731 * groups in current filesystem that have BACKUPS, or -ve error code.
732 */
733 static int verify_reserved_gdb(struct super_block *sb,
734 ext4_group_t end,
735 struct buffer_head *primary)
736 {
737 const ext4_fsblk_t blk = primary->b_blocknr;
738 unsigned three = 1;
739 unsigned five = 5;
740 unsigned seven = 7;
741 unsigned grp;
742 __le32 *p = (__le32 *)primary->b_data;
743 int gdbackups = 0;
744
745 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) {
746 if (le32_to_cpu(*p++) !=
747 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){
748 ext4_warning(sb, "reserved GDT %llu"
749 " missing grp %d (%llu)",
750 blk, grp,
751 grp *
752 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
753 blk);
754 return -EINVAL;
755 }
756 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb))
757 return -EFBIG;
758 }
759
760 return gdbackups;
761 }
762
763 /*
764 * Called when we need to bring a reserved group descriptor table block into
765 * use from the resize inode. The primary copy of the new GDT block currently
766 * is an indirect block (under the double indirect block in the resize inode).
767 * The new backup GDT blocks will be stored as leaf blocks in this indirect
768 * block, in group order. Even though we know all the block numbers we need,
769 * we check to ensure that the resize inode has actually reserved these blocks.
770 *
771 * Don't need to update the block bitmaps because the blocks are still in use.
772 *
773 * We get all of the error cases out of the way, so that we are sure to not
774 * fail once we start modifying the data on disk, because JBD has no rollback.
775 */
776 static int add_new_gdb(handle_t *handle, struct inode *inode,
777 ext4_group_t group)
778 {
779 struct super_block *sb = inode->i_sb;
780 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
781 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
782 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
783 struct buffer_head **o_group_desc, **n_group_desc;
784 struct buffer_head *dind;
785 struct buffer_head *gdb_bh;
786 int gdbackups;
787 struct ext4_iloc iloc;
788 __le32 *data;
789 int err;
790
791 if (test_opt(sb, DEBUG))
792 printk(KERN_DEBUG
793 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
794 gdb_num);
795
796 gdb_bh = sb_bread(sb, gdblock);
797 if (!gdb_bh)
798 return -EIO;
799
800 gdbackups = verify_reserved_gdb(sb, group, gdb_bh);
801 if (gdbackups < 0) {
802 err = gdbackups;
803 goto exit_bh;
804 }
805
806 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
807 dind = sb_bread(sb, le32_to_cpu(*data));
808 if (!dind) {
809 err = -EIO;
810 goto exit_bh;
811 }
812
813 data = (__le32 *)dind->b_data;
814 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) {
815 ext4_warning(sb, "new group %u GDT block %llu not reserved",
816 group, gdblock);
817 err = -EINVAL;
818 goto exit_dind;
819 }
820
821 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
822 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
823 if (unlikely(err))
824 goto exit_dind;
825
826 BUFFER_TRACE(gdb_bh, "get_write_access");
827 err = ext4_journal_get_write_access(handle, gdb_bh);
828 if (unlikely(err))
829 goto exit_dind;
830
831 BUFFER_TRACE(dind, "get_write_access");
832 err = ext4_journal_get_write_access(handle, dind);
833 if (unlikely(err))
834 ext4_std_error(sb, err);
835
836 /* ext4_reserve_inode_write() gets a reference on the iloc */
837 err = ext4_reserve_inode_write(handle, inode, &iloc);
838 if (unlikely(err))
839 goto exit_dind;
840
841 n_group_desc = ext4_kvmalloc((gdb_num + 1) *
842 sizeof(struct buffer_head *),
843 GFP_NOFS);
844 if (!n_group_desc) {
845 err = -ENOMEM;
846 ext4_warning(sb, "not enough memory for %lu groups",
847 gdb_num + 1);
848 goto exit_inode;
849 }
850
851 /*
852 * Finally, we have all of the possible failures behind us...
853 *
854 * Remove new GDT block from inode double-indirect block and clear out
855 * the new GDT block for use (which also "frees" the backup GDT blocks
856 * from the reserved inode). We don't need to change the bitmaps for
857 * these blocks, because they are marked as in-use from being in the
858 * reserved inode, and will become GDT blocks (primary and backup).
859 */
860 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0;
861 err = ext4_handle_dirty_metadata(handle, NULL, dind);
862 if (unlikely(err)) {
863 ext4_std_error(sb, err);
864 goto exit_inode;
865 }
866 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >>
867 (9 - EXT4_SB(sb)->s_cluster_bits);
868 ext4_mark_iloc_dirty(handle, inode, &iloc);
869 memset(gdb_bh->b_data, 0, sb->s_blocksize);
870 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
871 if (unlikely(err)) {
872 ext4_std_error(sb, err);
873 goto exit_inode;
874 }
875 brelse(dind);
876
877 o_group_desc = EXT4_SB(sb)->s_group_desc;
878 memcpy(n_group_desc, o_group_desc,
879 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
880 n_group_desc[gdb_num] = gdb_bh;
881 EXT4_SB(sb)->s_group_desc = n_group_desc;
882 EXT4_SB(sb)->s_gdb_count++;
883 kvfree(o_group_desc);
884
885 le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
886 err = ext4_handle_dirty_super(handle, sb);
887 if (err)
888 ext4_std_error(sb, err);
889
890 return err;
891
892 exit_inode:
893 kvfree(n_group_desc);
894 brelse(iloc.bh);
895 exit_dind:
896 brelse(dind);
897 exit_bh:
898 brelse(gdb_bh);
899
900 ext4_debug("leaving with error %d\n", err);
901 return err;
902 }
903
904 /*
905 * add_new_gdb_meta_bg is the sister of add_new_gdb.
906 */
907 static int add_new_gdb_meta_bg(struct super_block *sb,
908 handle_t *handle, ext4_group_t group) {
909 ext4_fsblk_t gdblock;
910 struct buffer_head *gdb_bh;
911 struct buffer_head **o_group_desc, **n_group_desc;
912 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
913 int err;
914
915 gdblock = ext4_meta_bg_first_block_no(sb, group) +
916 ext4_bg_has_super(sb, group);
917 gdb_bh = sb_bread(sb, gdblock);
918 if (!gdb_bh)
919 return -EIO;
920 n_group_desc = ext4_kvmalloc((gdb_num + 1) *
921 sizeof(struct buffer_head *),
922 GFP_NOFS);
923 if (!n_group_desc) {
924 err = -ENOMEM;
925 ext4_warning(sb, "not enough memory for %lu groups",
926 gdb_num + 1);
927 return err;
928 }
929
930 o_group_desc = EXT4_SB(sb)->s_group_desc;
931 memcpy(n_group_desc, o_group_desc,
932 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
933 n_group_desc[gdb_num] = gdb_bh;
934 EXT4_SB(sb)->s_group_desc = n_group_desc;
935 EXT4_SB(sb)->s_gdb_count++;
936 kvfree(o_group_desc);
937 BUFFER_TRACE(gdb_bh, "get_write_access");
938 err = ext4_journal_get_write_access(handle, gdb_bh);
939 if (unlikely(err))
940 brelse(gdb_bh);
941 return err;
942 }
943
944 /*
945 * Called when we are adding a new group which has a backup copy of each of
946 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
947 * We need to add these reserved backup GDT blocks to the resize inode, so
948 * that they are kept for future resizing and not allocated to files.
949 *
950 * Each reserved backup GDT block will go into a different indirect block.
951 * The indirect blocks are actually the primary reserved GDT blocks,
952 * so we know in advance what their block numbers are. We only get the
953 * double-indirect block to verify it is pointing to the primary reserved
954 * GDT blocks so we don't overwrite a data block by accident. The reserved
955 * backup GDT blocks are stored in their reserved primary GDT block.
956 */
957 static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
958 ext4_group_t group)
959 {
960 struct super_block *sb = inode->i_sb;
961 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
962 int cluster_bits = EXT4_SB(sb)->s_cluster_bits;
963 struct buffer_head **primary;
964 struct buffer_head *dind;
965 struct ext4_iloc iloc;
966 ext4_fsblk_t blk;
967 __le32 *data, *end;
968 int gdbackups = 0;
969 int res, i;
970 int err;
971
972 primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS);
973 if (!primary)
974 return -ENOMEM;
975
976 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
977 dind = sb_bread(sb, le32_to_cpu(*data));
978 if (!dind) {
979 err = -EIO;
980 goto exit_free;
981 }
982
983 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count;
984 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count %
985 EXT4_ADDR_PER_BLOCK(sb));
986 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb);
987
988 /* Get each reserved primary GDT block and verify it holds backups */
989 for (res = 0; res < reserved_gdb; res++, blk++) {
990 if (le32_to_cpu(*data) != blk) {
991 ext4_warning(sb, "reserved block %llu"
992 " not at offset %ld",
993 blk,
994 (long)(data - (__le32 *)dind->b_data));
995 err = -EINVAL;
996 goto exit_bh;
997 }
998 primary[res] = sb_bread(sb, blk);
999 if (!primary[res]) {
1000 err = -EIO;
1001 goto exit_bh;
1002 }
1003 gdbackups = verify_reserved_gdb(sb, group, primary[res]);
1004 if (gdbackups < 0) {
1005 brelse(primary[res]);
1006 err = gdbackups;
1007 goto exit_bh;
1008 }
1009 if (++data >= end)
1010 data = (__le32 *)dind->b_data;
1011 }
1012
1013 for (i = 0; i < reserved_gdb; i++) {
1014 BUFFER_TRACE(primary[i], "get_write_access");
1015 if ((err = ext4_journal_get_write_access(handle, primary[i])))
1016 goto exit_bh;
1017 }
1018
1019 if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
1020 goto exit_bh;
1021
1022 /*
1023 * Finally we can add each of the reserved backup GDT blocks from
1024 * the new group to its reserved primary GDT block.
1025 */
1026 blk = group * EXT4_BLOCKS_PER_GROUP(sb);
1027 for (i = 0; i < reserved_gdb; i++) {
1028 int err2;
1029 data = (__le32 *)primary[i]->b_data;
1030 /* printk("reserving backup %lu[%u] = %lu\n",
1031 primary[i]->b_blocknr, gdbackups,
1032 blk + primary[i]->b_blocknr); */
1033 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
1034 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]);
1035 if (!err)
1036 err = err2;
1037 }
1038
1039 inode->i_blocks += reserved_gdb * sb->s_blocksize >> (9 - cluster_bits);
1040 ext4_mark_iloc_dirty(handle, inode, &iloc);
1041
1042 exit_bh:
1043 while (--res >= 0)
1044 brelse(primary[res]);
1045 brelse(dind);
1046
1047 exit_free:
1048 kfree(primary);
1049
1050 return err;
1051 }
1052
1053 /*
1054 * Update the backup copies of the ext4 metadata. These don't need to be part
1055 * of the main resize transaction, because e2fsck will re-write them if there
1056 * is a problem (basically only OOM will cause a problem). However, we
1057 * _should_ update the backups if possible, in case the primary gets trashed
1058 * for some reason and we need to run e2fsck from a backup superblock. The
1059 * important part is that the new block and inode counts are in the backup
1060 * superblocks, and the location of the new group metadata in the GDT backups.
1061 *
1062 * We do not need take the s_resize_lock for this, because these
1063 * blocks are not otherwise touched by the filesystem code when it is
1064 * mounted. We don't need to worry about last changing from
1065 * sbi->s_groups_count, because the worst that can happen is that we
1066 * do not copy the full number of backups at this time. The resize
1067 * which changed s_groups_count will backup again.
1068 */
1069 static void update_backups(struct super_block *sb, sector_t blk_off, char *data,
1070 int size, int meta_bg)
1071 {
1072 struct ext4_sb_info *sbi = EXT4_SB(sb);
1073 ext4_group_t last;
1074 const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
1075 unsigned three = 1;
1076 unsigned five = 5;
1077 unsigned seven = 7;
1078 ext4_group_t group = 0;
1079 int rest = sb->s_blocksize - size;
1080 handle_t *handle;
1081 int err = 0, err2;
1082
1083 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA);
1084 if (IS_ERR(handle)) {
1085 group = 1;
1086 err = PTR_ERR(handle);
1087 goto exit_err;
1088 }
1089
1090 if (meta_bg == 0) {
1091 group = ext4_list_backups(sb, &three, &five, &seven);
1092 last = sbi->s_groups_count;
1093 } else {
1094 group = ext4_get_group_number(sb, blk_off) + 1;
1095 last = (ext4_group_t)(group + EXT4_DESC_PER_BLOCK(sb) - 2);
1096 }
1097
1098 while (group < sbi->s_groups_count) {
1099 struct buffer_head *bh;
1100 ext4_fsblk_t backup_block;
1101
1102 /* Out of journal space, and can't get more - abort - so sad */
1103 if (ext4_handle_valid(handle) &&
1104 handle->h_buffer_credits == 0 &&
1105 ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA) &&
1106 (err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
1107 break;
1108
1109 if (meta_bg == 0)
1110 backup_block = ((ext4_fsblk_t)group) * bpg + blk_off;
1111 else
1112 backup_block = (ext4_group_first_block_no(sb, group) +
1113 ext4_bg_has_super(sb, group));
1114
1115 bh = sb_getblk(sb, backup_block);
1116 if (unlikely(!bh)) {
1117 err = -ENOMEM;
1118 break;
1119 }
1120 ext4_debug("update metadata backup %llu(+%llu)\n",
1121 backup_block, backup_block -
1122 ext4_group_first_block_no(sb, group));
1123 BUFFER_TRACE(bh, "get_write_access");
1124 if ((err = ext4_journal_get_write_access(handle, bh)))
1125 break;
1126 lock_buffer(bh);
1127 memcpy(bh->b_data, data, size);
1128 if (rest)
1129 memset(bh->b_data + size, 0, rest);
1130 set_buffer_uptodate(bh);
1131 unlock_buffer(bh);
1132 err = ext4_handle_dirty_metadata(handle, NULL, bh);
1133 if (unlikely(err))
1134 ext4_std_error(sb, err);
1135 brelse(bh);
1136
1137 if (meta_bg == 0)
1138 group = ext4_list_backups(sb, &three, &five, &seven);
1139 else if (group == last)
1140 break;
1141 else
1142 group = last;
1143 }
1144 if ((err2 = ext4_journal_stop(handle)) && !err)
1145 err = err2;
1146
1147 /*
1148 * Ugh! Need to have e2fsck write the backup copies. It is too
1149 * late to revert the resize, we shouldn't fail just because of
1150 * the backup copies (they are only needed in case of corruption).
1151 *
1152 * However, if we got here we have a journal problem too, so we
1153 * can't really start a transaction to mark the superblock.
1154 * Chicken out and just set the flag on the hope it will be written
1155 * to disk, and if not - we will simply wait until next fsck.
1156 */
1157 exit_err:
1158 if (err) {
1159 ext4_warning(sb, "can't update backup for group %u (err %d), "
1160 "forcing fsck on next reboot", group, err);
1161 sbi->s_mount_state &= ~EXT4_VALID_FS;
1162 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1163 mark_buffer_dirty(sbi->s_sbh);
1164 }
1165 }
1166
1167 /*
1168 * ext4_add_new_descs() adds @count group descriptor of groups
1169 * starting at @group
1170 *
1171 * @handle: journal handle
1172 * @sb: super block
1173 * @group: the group no. of the first group desc to be added
1174 * @resize_inode: the resize inode
1175 * @count: number of group descriptors to be added
1176 */
1177 static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
1178 ext4_group_t group, struct inode *resize_inode,
1179 ext4_group_t count)
1180 {
1181 struct ext4_sb_info *sbi = EXT4_SB(sb);
1182 struct ext4_super_block *es = sbi->s_es;
1183 struct buffer_head *gdb_bh;
1184 int i, gdb_off, gdb_num, err = 0;
1185 int meta_bg;
1186
1187 meta_bg = ext4_has_feature_meta_bg(sb);
1188 for (i = 0; i < count; i++, group++) {
1189 int reserved_gdb = ext4_bg_has_super(sb, group) ?
1190 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
1191
1192 gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
1193 gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1194
1195 /*
1196 * We will only either add reserved group blocks to a backup group
1197 * or remove reserved blocks for the first group in a new group block.
1198 * Doing both would be mean more complex code, and sane people don't
1199 * use non-sparse filesystems anymore. This is already checked above.
1200 */
1201 if (gdb_off) {
1202 gdb_bh = sbi->s_group_desc[gdb_num];
1203 BUFFER_TRACE(gdb_bh, "get_write_access");
1204 err = ext4_journal_get_write_access(handle, gdb_bh);
1205
1206 if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group))
1207 err = reserve_backup_gdb(handle, resize_inode, group);
1208 } else if (meta_bg != 0) {
1209 err = add_new_gdb_meta_bg(sb, handle, group);
1210 } else {
1211 err = add_new_gdb(handle, resize_inode, group);
1212 }
1213 if (err)
1214 break;
1215 }
1216 return err;
1217 }
1218
1219 static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block)
1220 {
1221 struct buffer_head *bh = sb_getblk(sb, block);
1222 if (unlikely(!bh))
1223 return NULL;
1224 if (!bh_uptodate_or_lock(bh)) {
1225 if (bh_submit_read(bh) < 0) {
1226 brelse(bh);
1227 return NULL;
1228 }
1229 }
1230
1231 return bh;
1232 }
1233
1234 static int ext4_set_bitmap_checksums(struct super_block *sb,
1235 ext4_group_t group,
1236 struct ext4_group_desc *gdp,
1237 struct ext4_new_group_data *group_data)
1238 {
1239 struct buffer_head *bh;
1240
1241 if (!ext4_has_metadata_csum(sb))
1242 return 0;
1243
1244 bh = ext4_get_bitmap(sb, group_data->inode_bitmap);
1245 if (!bh)
1246 return -EIO;
1247 ext4_inode_bitmap_csum_set(sb, group, gdp, bh,
1248 EXT4_INODES_PER_GROUP(sb) / 8);
1249 brelse(bh);
1250
1251 bh = ext4_get_bitmap(sb, group_data->block_bitmap);
1252 if (!bh)
1253 return -EIO;
1254 ext4_block_bitmap_csum_set(sb, group, gdp, bh);
1255 brelse(bh);
1256
1257 return 0;
1258 }
1259
1260 /*
1261 * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg
1262 */
1263 static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb,
1264 struct ext4_new_flex_group_data *flex_gd)
1265 {
1266 struct ext4_new_group_data *group_data = flex_gd->groups;
1267 struct ext4_group_desc *gdp;
1268 struct ext4_sb_info *sbi = EXT4_SB(sb);
1269 struct buffer_head *gdb_bh;
1270 ext4_group_t group;
1271 __u16 *bg_flags = flex_gd->bg_flags;
1272 int i, gdb_off, gdb_num, err = 0;
1273
1274
1275 for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) {
1276 group = group_data->group;
1277
1278 gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
1279 gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1280
1281 /*
1282 * get_write_access() has been called on gdb_bh by ext4_add_new_desc().
1283 */
1284 gdb_bh = sbi->s_group_desc[gdb_num];
1285 /* Update group descriptor block for new group */
1286 gdp = (struct ext4_group_desc *)(gdb_bh->b_data +
1287 gdb_off * EXT4_DESC_SIZE(sb));
1288
1289 memset(gdp, 0, EXT4_DESC_SIZE(sb));
1290 ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap);
1291 ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap);
1292 err = ext4_set_bitmap_checksums(sb, group, gdp, group_data);
1293 if (err) {
1294 ext4_std_error(sb, err);
1295 break;
1296 }
1297
1298 ext4_inode_table_set(sb, gdp, group_data->inode_table);
1299 ext4_free_group_clusters_set(sb, gdp,
1300 group_data->free_clusters_count);
1301 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
1302 if (ext4_has_group_desc_csum(sb))
1303 ext4_itable_unused_set(sb, gdp,
1304 EXT4_INODES_PER_GROUP(sb));
1305 gdp->bg_flags = cpu_to_le16(*bg_flags);
1306 ext4_group_desc_csum_set(sb, group, gdp);
1307
1308 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
1309 if (unlikely(err)) {
1310 ext4_std_error(sb, err);
1311 break;
1312 }
1313
1314 /*
1315 * We can allocate memory for mb_alloc based on the new group
1316 * descriptor
1317 */
1318 err = ext4_mb_add_groupinfo(sb, group, gdp);
1319 if (err)
1320 break;
1321 }
1322 return err;
1323 }
1324
1325 /*
1326 * ext4_update_super() updates the super block so that the newly added
1327 * groups can be seen by the filesystem.
1328 *
1329 * @sb: super block
1330 * @flex_gd: new added groups
1331 */
1332 static void ext4_update_super(struct super_block *sb,
1333 struct ext4_new_flex_group_data *flex_gd)
1334 {
1335 ext4_fsblk_t blocks_count = 0;
1336 ext4_fsblk_t free_blocks = 0;
1337 ext4_fsblk_t reserved_blocks = 0;
1338 struct ext4_new_group_data *group_data = flex_gd->groups;
1339 struct ext4_sb_info *sbi = EXT4_SB(sb);
1340 struct ext4_super_block *es = sbi->s_es;
1341 int i;
1342
1343 BUG_ON(flex_gd->count == 0 || group_data == NULL);
1344 /*
1345 * Make the new blocks and inodes valid next. We do this before
1346 * increasing the group count so that once the group is enabled,
1347 * all of its blocks and inodes are already valid.
1348 *
1349 * We always allocate group-by-group, then block-by-block or
1350 * inode-by-inode within a group, so enabling these
1351 * blocks/inodes before the group is live won't actually let us
1352 * allocate the new space yet.
1353 */
1354 for (i = 0; i < flex_gd->count; i++) {
1355 blocks_count += group_data[i].blocks_count;
1356 free_blocks += EXT4_C2B(sbi, group_data[i].free_clusters_count);
1357 }
1358
1359 reserved_blocks = ext4_r_blocks_count(es) * 100;
1360 reserved_blocks = div64_u64(reserved_blocks, ext4_blocks_count(es));
1361 reserved_blocks *= blocks_count;
1362 do_div(reserved_blocks, 100);
1363
1364 ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count);
1365 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks);
1366 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) *
1367 flex_gd->count);
1368 le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) *
1369 flex_gd->count);
1370
1371 ext4_debug("free blocks count %llu", ext4_free_blocks_count(es));
1372 /*
1373 * We need to protect s_groups_count against other CPUs seeing
1374 * inconsistent state in the superblock.
1375 *
1376 * The precise rules we use are:
1377 *
1378 * * Writers must perform a smp_wmb() after updating all
1379 * dependent data and before modifying the groups count
1380 *
1381 * * Readers must perform an smp_rmb() after reading the groups
1382 * count and before reading any dependent data.
1383 *
1384 * NB. These rules can be relaxed when checking the group count
1385 * while freeing data, as we can only allocate from a block
1386 * group after serialising against the group count, and we can
1387 * only then free after serialising in turn against that
1388 * allocation.
1389 */
1390 smp_wmb();
1391
1392 /* Update the global fs size fields */
1393 sbi->s_groups_count += flex_gd->count;
1394 sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
1395 (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
1396
1397 /* Update the reserved block counts only once the new group is
1398 * active. */
1399 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) +
1400 reserved_blocks);
1401
1402 /* Update the free space counts */
1403 percpu_counter_add(&sbi->s_freeclusters_counter,
1404 EXT4_NUM_B2C(sbi, free_blocks));
1405 percpu_counter_add(&sbi->s_freeinodes_counter,
1406 EXT4_INODES_PER_GROUP(sb) * flex_gd->count);
1407
1408 ext4_debug("free blocks count %llu",
1409 percpu_counter_read(&sbi->s_freeclusters_counter));
1410 if (ext4_has_feature_flex_bg(sb) && sbi->s_log_groups_per_flex) {
1411 ext4_group_t flex_group;
1412 flex_group = ext4_flex_group(sbi, group_data[0].group);
1413 atomic64_add(EXT4_NUM_B2C(sbi, free_blocks),
1414 &sbi->s_flex_groups[flex_group].free_clusters);
1415 atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count,
1416 &sbi->s_flex_groups[flex_group].free_inodes);
1417 }
1418
1419 /*
1420 * Update the fs overhead information
1421 */
1422 ext4_calculate_overhead(sb);
1423
1424 if (test_opt(sb, DEBUG))
1425 printk(KERN_DEBUG "EXT4-fs: added group %u:"
1426 "%llu blocks(%llu free %llu reserved)\n", flex_gd->count,
1427 blocks_count, free_blocks, reserved_blocks);
1428 }
1429
1430 /* Add a flex group to an fs. Ensure we handle all possible error conditions
1431 * _before_ we start modifying the filesystem, because we cannot abort the
1432 * transaction and not have it write the data to disk.
1433 */
1434 static int ext4_flex_group_add(struct super_block *sb,
1435 struct inode *resize_inode,
1436 struct ext4_new_flex_group_data *flex_gd)
1437 {
1438 struct ext4_sb_info *sbi = EXT4_SB(sb);
1439 struct ext4_super_block *es = sbi->s_es;
1440 ext4_fsblk_t o_blocks_count;
1441 ext4_grpblk_t last;
1442 ext4_group_t group;
1443 handle_t *handle;
1444 unsigned reserved_gdb;
1445 int err = 0, err2 = 0, credit;
1446
1447 BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags);
1448
1449 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
1450 o_blocks_count = ext4_blocks_count(es);
1451 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1452 BUG_ON(last);
1453
1454 err = setup_new_flex_group_blocks(sb, flex_gd);
1455 if (err)
1456 goto exit;
1457 /*
1458 * We will always be modifying at least the superblock and GDT
1459 * blocks. If we are adding a group past the last current GDT block,
1460 * we will also modify the inode and the dindirect block. If we
1461 * are adding a group with superblock/GDT backups we will also
1462 * modify each of the reserved GDT dindirect blocks.
1463 */
1464 credit = 3; /* sb, resize inode, resize inode dindirect */
1465 /* GDT blocks */
1466 credit += 1 + DIV_ROUND_UP(flex_gd->count, EXT4_DESC_PER_BLOCK(sb));
1467 credit += reserved_gdb; /* Reserved GDT dindirect blocks */
1468 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credit);
1469 if (IS_ERR(handle)) {
1470 err = PTR_ERR(handle);
1471 goto exit;
1472 }
1473
1474 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
1475 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
1476 if (err)
1477 goto exit_journal;
1478
1479 group = flex_gd->groups[0].group;
1480 BUG_ON(group != EXT4_SB(sb)->s_groups_count);
1481 err = ext4_add_new_descs(handle, sb, group,
1482 resize_inode, flex_gd->count);
1483 if (err)
1484 goto exit_journal;
1485
1486 err = ext4_setup_new_descs(handle, sb, flex_gd);
1487 if (err)
1488 goto exit_journal;
1489
1490 ext4_update_super(sb, flex_gd);
1491
1492 err = ext4_handle_dirty_super(handle, sb);
1493
1494 exit_journal:
1495 err2 = ext4_journal_stop(handle);
1496 if (!err)
1497 err = err2;
1498
1499 if (!err) {
1500 int gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1501 int gdb_num_end = ((group + flex_gd->count - 1) /
1502 EXT4_DESC_PER_BLOCK(sb));
1503 int meta_bg = ext4_has_feature_meta_bg(sb);
1504 sector_t old_gdb = 0;
1505
1506 update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
1507 sizeof(struct ext4_super_block), 0);
1508 for (; gdb_num <= gdb_num_end; gdb_num++) {
1509 struct buffer_head *gdb_bh;
1510
1511 gdb_bh = sbi->s_group_desc[gdb_num];
1512 if (old_gdb == gdb_bh->b_blocknr)
1513 continue;
1514 update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data,
1515 gdb_bh->b_size, meta_bg);
1516 old_gdb = gdb_bh->b_blocknr;
1517 }
1518 }
1519 exit:
1520 return err;
1521 }
1522
1523 static int ext4_setup_next_flex_gd(struct super_block *sb,
1524 struct ext4_new_flex_group_data *flex_gd,
1525 ext4_fsblk_t n_blocks_count,
1526 unsigned long flexbg_size)
1527 {
1528 struct ext4_sb_info *sbi = EXT4_SB(sb);
1529 struct ext4_super_block *es = sbi->s_es;
1530 struct ext4_new_group_data *group_data = flex_gd->groups;
1531 ext4_fsblk_t o_blocks_count;
1532 ext4_group_t n_group;
1533 ext4_group_t group;
1534 ext4_group_t last_group;
1535 ext4_grpblk_t last;
1536 ext4_grpblk_t clusters_per_group;
1537 unsigned long i;
1538
1539 clusters_per_group = EXT4_CLUSTERS_PER_GROUP(sb);
1540
1541 o_blocks_count = ext4_blocks_count(es);
1542
1543 if (o_blocks_count == n_blocks_count)
1544 return 0;
1545
1546 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1547 BUG_ON(last);
1548 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last);
1549
1550 last_group = group | (flexbg_size - 1);
1551 if (last_group > n_group)
1552 last_group = n_group;
1553
1554 flex_gd->count = last_group - group + 1;
1555
1556 for (i = 0; i < flex_gd->count; i++) {
1557 int overhead;
1558
1559 group_data[i].group = group + i;
1560 group_data[i].blocks_count = EXT4_BLOCKS_PER_GROUP(sb);
1561 overhead = ext4_group_overhead_blocks(sb, group + i);
1562 group_data[i].mdata_blocks = overhead;
1563 group_data[i].free_clusters_count = EXT4_CLUSTERS_PER_GROUP(sb);
1564 if (ext4_has_group_desc_csum(sb)) {
1565 flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT |
1566 EXT4_BG_INODE_UNINIT;
1567 if (!test_opt(sb, INIT_INODE_TABLE))
1568 flex_gd->bg_flags[i] |= EXT4_BG_INODE_ZEROED;
1569 } else
1570 flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED;
1571 }
1572
1573 if (last_group == n_group && ext4_has_group_desc_csum(sb))
1574 /* We need to initialize block bitmap of last group. */
1575 flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT;
1576
1577 if ((last_group == n_group) && (last != clusters_per_group - 1)) {
1578 group_data[i - 1].blocks_count = EXT4_C2B(sbi, last + 1);
1579 group_data[i - 1].free_clusters_count -= clusters_per_group -
1580 last - 1;
1581 }
1582
1583 return 1;
1584 }
1585
1586 /* Add group descriptor data to an existing or new group descriptor block.
1587 * Ensure we handle all possible error conditions _before_ we start modifying
1588 * the filesystem, because we cannot abort the transaction and not have it
1589 * write the data to disk.
1590 *
1591 * If we are on a GDT block boundary, we need to get the reserved GDT block.
1592 * Otherwise, we may need to add backup GDT blocks for a sparse group.
1593 *
1594 * We only need to hold the superblock lock while we are actually adding
1595 * in the new group's counts to the superblock. Prior to that we have
1596 * not really "added" the group at all. We re-check that we are still
1597 * adding in the last group in case things have changed since verifying.
1598 */
1599 int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
1600 {
1601 struct ext4_new_flex_group_data flex_gd;
1602 struct ext4_sb_info *sbi = EXT4_SB(sb);
1603 struct ext4_super_block *es = sbi->s_es;
1604 int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
1605 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
1606 struct inode *inode = NULL;
1607 int gdb_off;
1608 int err;
1609 __u16 bg_flags = 0;
1610
1611 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb);
1612
1613 if (gdb_off == 0 && !ext4_has_feature_sparse_super(sb)) {
1614 ext4_warning(sb, "Can't resize non-sparse filesystem further");
1615 return -EPERM;
1616 }
1617
1618 if (ext4_blocks_count(es) + input->blocks_count <
1619 ext4_blocks_count(es)) {
1620 ext4_warning(sb, "blocks_count overflow");
1621 return -EINVAL;
1622 }
1623
1624 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) <
1625 le32_to_cpu(es->s_inodes_count)) {
1626 ext4_warning(sb, "inodes_count overflow");
1627 return -EINVAL;
1628 }
1629
1630 if (reserved_gdb || gdb_off == 0) {
1631 if (ext4_has_feature_resize_inode(sb) ||
1632 !le16_to_cpu(es->s_reserved_gdt_blocks)) {
1633 ext4_warning(sb,
1634 "No reserved GDT blocks, can't resize");
1635 return -EPERM;
1636 }
1637 inode = ext4_iget(sb, EXT4_RESIZE_INO);
1638 if (IS_ERR(inode)) {
1639 ext4_warning(sb, "Error opening resize inode");
1640 return PTR_ERR(inode);
1641 }
1642 }
1643
1644
1645 err = verify_group_input(sb, input);
1646 if (err)
1647 goto out;
1648
1649 err = ext4_alloc_flex_bg_array(sb, input->group + 1);
1650 if (err)
1651 goto out;
1652
1653 err = ext4_mb_alloc_groupinfo(sb, input->group + 1);
1654 if (err)
1655 goto out;
1656
1657 flex_gd.count = 1;
1658 flex_gd.groups = input;
1659 flex_gd.bg_flags = &bg_flags;
1660 err = ext4_flex_group_add(sb, inode, &flex_gd);
1661 out:
1662 iput(inode);
1663 return err;
1664 } /* ext4_group_add */
1665
1666 /*
1667 * extend a group without checking assuming that checking has been done.
1668 */
1669 static int ext4_group_extend_no_check(struct super_block *sb,
1670 ext4_fsblk_t o_blocks_count, ext4_grpblk_t add)
1671 {
1672 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1673 handle_t *handle;
1674 int err = 0, err2;
1675
1676 /* We will update the superblock, one block bitmap, and
1677 * one group descriptor via ext4_group_add_blocks().
1678 */
1679 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, 3);
1680 if (IS_ERR(handle)) {
1681 err = PTR_ERR(handle);
1682 ext4_warning(sb, "error %d on journal start", err);
1683 return err;
1684 }
1685
1686 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
1687 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
1688 if (err) {
1689 ext4_warning(sb, "error %d on journal write access", err);
1690 goto errout;
1691 }
1692
1693 ext4_blocks_count_set(es, o_blocks_count + add);
1694 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add);
1695 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
1696 o_blocks_count + add);
1697 /* We add the blocks to the bitmap and set the group need init bit */
1698 err = ext4_group_add_blocks(handle, sb, o_blocks_count, add);
1699 if (err)
1700 goto errout;
1701 ext4_handle_dirty_super(handle, sb);
1702 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
1703 o_blocks_count + add);
1704 errout:
1705 err2 = ext4_journal_stop(handle);
1706 if (err2 && !err)
1707 err = err2;
1708
1709 if (!err) {
1710 if (test_opt(sb, DEBUG))
1711 printk(KERN_DEBUG "EXT4-fs: extended group to %llu "
1712 "blocks\n", ext4_blocks_count(es));
1713 update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr,
1714 (char *)es, sizeof(struct ext4_super_block), 0);
1715 }
1716 return err;
1717 }
1718
1719 /*
1720 * Extend the filesystem to the new number of blocks specified. This entry
1721 * point is only used to extend the current filesystem to the end of the last
1722 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>"
1723 * for emergencies (because it has no dependencies on reserved blocks).
1724 *
1725 * If we _really_ wanted, we could use default values to call ext4_group_add()
1726 * allow the "remount" trick to work for arbitrary resizing, assuming enough
1727 * GDT blocks are reserved to grow to the desired size.
1728 */
1729 int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
1730 ext4_fsblk_t n_blocks_count)
1731 {
1732 ext4_fsblk_t o_blocks_count;
1733 ext4_grpblk_t last;
1734 ext4_grpblk_t add;
1735 struct buffer_head *bh;
1736 int err;
1737 ext4_group_t group;
1738
1739 o_blocks_count = ext4_blocks_count(es);
1740
1741 if (test_opt(sb, DEBUG))
1742 ext4_msg(sb, KERN_DEBUG,
1743 "extending last group from %llu to %llu blocks",
1744 o_blocks_count, n_blocks_count);
1745
1746 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
1747 return 0;
1748
1749 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1750 ext4_msg(sb, KERN_ERR,
1751 "filesystem too large to resize to %llu blocks safely",
1752 n_blocks_count);
1753 if (sizeof(sector_t) < 8)
1754 ext4_warning(sb, "CONFIG_LBDAF not enabled");
1755 return -EINVAL;
1756 }
1757
1758 if (n_blocks_count < o_blocks_count) {
1759 ext4_warning(sb, "can't shrink FS - resize aborted");
1760 return -EINVAL;
1761 }
1762
1763 /* Handle the remaining blocks in the last group only. */
1764 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1765
1766 if (last == 0) {
1767 ext4_warning(sb, "need to use ext2online to resize further");
1768 return -EPERM;
1769 }
1770
1771 add = EXT4_BLOCKS_PER_GROUP(sb) - last;
1772
1773 if (o_blocks_count + add < o_blocks_count) {
1774 ext4_warning(sb, "blocks_count overflow");
1775 return -EINVAL;
1776 }
1777
1778 if (o_blocks_count + add > n_blocks_count)
1779 add = n_blocks_count - o_blocks_count;
1780
1781 if (o_blocks_count + add < n_blocks_count)
1782 ext4_warning(sb, "will only finish group (%llu blocks, %u new)",
1783 o_blocks_count + add, add);
1784
1785 /* See if the device is actually as big as what was requested */
1786 bh = sb_bread(sb, o_blocks_count + add - 1);
1787 if (!bh) {
1788 ext4_warning(sb, "can't read last block, resize aborted");
1789 return -ENOSPC;
1790 }
1791 brelse(bh);
1792
1793 err = ext4_group_extend_no_check(sb, o_blocks_count, add);
1794 return err;
1795 } /* ext4_group_extend */
1796
1797
1798 static int num_desc_blocks(struct super_block *sb, ext4_group_t groups)
1799 {
1800 return (groups + EXT4_DESC_PER_BLOCK(sb) - 1) / EXT4_DESC_PER_BLOCK(sb);
1801 }
1802
1803 /*
1804 * Release the resize inode and drop the resize_inode feature if there
1805 * are no more reserved gdt blocks, and then convert the file system
1806 * to enable meta_bg
1807 */
1808 static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode)
1809 {
1810 handle_t *handle;
1811 struct ext4_sb_info *sbi = EXT4_SB(sb);
1812 struct ext4_super_block *es = sbi->s_es;
1813 struct ext4_inode_info *ei = EXT4_I(inode);
1814 ext4_fsblk_t nr;
1815 int i, ret, err = 0;
1816 int credits = 1;
1817
1818 ext4_msg(sb, KERN_INFO, "Converting file system to meta_bg");
1819 if (inode) {
1820 if (es->s_reserved_gdt_blocks) {
1821 ext4_error(sb, "Unexpected non-zero "
1822 "s_reserved_gdt_blocks");
1823 return -EPERM;
1824 }
1825
1826 /* Do a quick sanity check of the resize inode */
1827 if (inode->i_blocks != 1 << (inode->i_blkbits -
1828 (9 - sbi->s_cluster_bits)))
1829 goto invalid_resize_inode;
1830 for (i = 0; i < EXT4_N_BLOCKS; i++) {
1831 if (i == EXT4_DIND_BLOCK) {
1832 if (ei->i_data[i])
1833 continue;
1834 else
1835 goto invalid_resize_inode;
1836 }
1837 if (ei->i_data[i])
1838 goto invalid_resize_inode;
1839 }
1840 credits += 3; /* block bitmap, bg descriptor, resize inode */
1841 }
1842
1843 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credits);
1844 if (IS_ERR(handle))
1845 return PTR_ERR(handle);
1846
1847 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
1848 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
1849 if (err)
1850 goto errout;
1851
1852 ext4_clear_feature_resize_inode(sb);
1853 ext4_set_feature_meta_bg(sb);
1854 sbi->s_es->s_first_meta_bg =
1855 cpu_to_le32(num_desc_blocks(sb, sbi->s_groups_count));
1856
1857 err = ext4_handle_dirty_super(handle, sb);
1858 if (err) {
1859 ext4_std_error(sb, err);
1860 goto errout;
1861 }
1862
1863 if (inode) {
1864 nr = le32_to_cpu(ei->i_data[EXT4_DIND_BLOCK]);
1865 ext4_free_blocks(handle, inode, NULL, nr, 1,
1866 EXT4_FREE_BLOCKS_METADATA |
1867 EXT4_FREE_BLOCKS_FORGET);
1868 ei->i_data[EXT4_DIND_BLOCK] = 0;
1869 inode->i_blocks = 0;
1870
1871 err = ext4_mark_inode_dirty(handle, inode);
1872 if (err)
1873 ext4_std_error(sb, err);
1874 }
1875
1876 errout:
1877 ret = ext4_journal_stop(handle);
1878 if (!err)
1879 err = ret;
1880 return ret;
1881
1882 invalid_resize_inode:
1883 ext4_error(sb, "corrupted/inconsistent resize inode");
1884 return -EINVAL;
1885 }
1886
1887 /*
1888 * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count
1889 *
1890 * @sb: super block of the fs to be resized
1891 * @n_blocks_count: the number of blocks resides in the resized fs
1892 */
1893 int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
1894 {
1895 struct ext4_new_flex_group_data *flex_gd = NULL;
1896 struct ext4_sb_info *sbi = EXT4_SB(sb);
1897 struct ext4_super_block *es = sbi->s_es;
1898 struct buffer_head *bh;
1899 struct inode *resize_inode = NULL;
1900 ext4_grpblk_t add, offset;
1901 unsigned long n_desc_blocks;
1902 unsigned long o_desc_blocks;
1903 ext4_group_t o_group;
1904 ext4_group_t n_group;
1905 ext4_fsblk_t o_blocks_count;
1906 ext4_fsblk_t n_blocks_count_retry = 0;
1907 unsigned long last_update_time = 0;
1908 int err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex;
1909 int meta_bg;
1910
1911 /* See if the device is actually as big as what was requested */
1912 bh = sb_bread(sb, n_blocks_count - 1);
1913 if (!bh) {
1914 ext4_warning(sb, "can't read last block, resize aborted");
1915 return -ENOSPC;
1916 }
1917 brelse(bh);
1918
1919 retry:
1920 o_blocks_count = ext4_blocks_count(es);
1921
1922 ext4_msg(sb, KERN_INFO, "resizing filesystem from %llu "
1923 "to %llu blocks", o_blocks_count, n_blocks_count);
1924
1925 if (n_blocks_count < o_blocks_count) {
1926 /* On-line shrinking not supported */
1927 ext4_warning(sb, "can't shrink FS - resize aborted");
1928 return -EINVAL;
1929 }
1930
1931 if (n_blocks_count == o_blocks_count)
1932 /* Nothing need to do */
1933 return 0;
1934
1935 n_group = ext4_get_group_number(sb, n_blocks_count - 1);
1936 if (n_group > (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) {
1937 ext4_warning(sb, "resize would cause inodes_count overflow");
1938 return -EINVAL;
1939 }
1940 ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset);
1941
1942 n_desc_blocks = num_desc_blocks(sb, n_group + 1);
1943 o_desc_blocks = num_desc_blocks(sb, sbi->s_groups_count);
1944
1945 meta_bg = ext4_has_feature_meta_bg(sb);
1946
1947 if (ext4_has_feature_resize_inode(sb)) {
1948 if (meta_bg) {
1949 ext4_error(sb, "resize_inode and meta_bg enabled "
1950 "simultaneously");
1951 return -EINVAL;
1952 }
1953 if (n_desc_blocks > o_desc_blocks +
1954 le16_to_cpu(es->s_reserved_gdt_blocks)) {
1955 n_blocks_count_retry = n_blocks_count;
1956 n_desc_blocks = o_desc_blocks +
1957 le16_to_cpu(es->s_reserved_gdt_blocks);
1958 n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb);
1959 n_blocks_count = (ext4_fsblk_t)n_group *
1960 EXT4_BLOCKS_PER_GROUP(sb);
1961 n_group--; /* set to last group number */
1962 }
1963
1964 if (!resize_inode)
1965 resize_inode = ext4_iget(sb, EXT4_RESIZE_INO);
1966 if (IS_ERR(resize_inode)) {
1967 ext4_warning(sb, "Error opening resize inode");
1968 return PTR_ERR(resize_inode);
1969 }
1970 }
1971
1972 if ((!resize_inode && !meta_bg) || n_blocks_count == o_blocks_count) {
1973 err = ext4_convert_meta_bg(sb, resize_inode);
1974 if (err)
1975 goto out;
1976 if (resize_inode) {
1977 iput(resize_inode);
1978 resize_inode = NULL;
1979 }
1980 if (n_blocks_count_retry) {
1981 n_blocks_count = n_blocks_count_retry;
1982 n_blocks_count_retry = 0;
1983 goto retry;
1984 }
1985 }
1986
1987 /* extend the last group */
1988 if (n_group == o_group)
1989 add = n_blocks_count - o_blocks_count;
1990 else
1991 add = EXT4_C2B(sbi, EXT4_CLUSTERS_PER_GROUP(sb) - (offset + 1));
1992 if (add > 0) {
1993 err = ext4_group_extend_no_check(sb, o_blocks_count, add);
1994 if (err)
1995 goto out;
1996 }
1997
1998 if (ext4_blocks_count(es) == n_blocks_count)
1999 goto out;
2000
2001 err = ext4_alloc_flex_bg_array(sb, n_group + 1);
2002 if (err)
2003 return err;
2004
2005 err = ext4_mb_alloc_groupinfo(sb, n_group + 1);
2006 if (err)
2007 goto out;
2008
2009 flex_gd = alloc_flex_gd(flexbg_size);
2010 if (flex_gd == NULL) {
2011 err = -ENOMEM;
2012 goto out;
2013 }
2014
2015 /* Add flex groups. Note that a regular group is a
2016 * flex group with 1 group.
2017 */
2018 while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count,
2019 flexbg_size)) {
2020 if (jiffies - last_update_time > HZ * 10) {
2021 if (last_update_time)
2022 ext4_msg(sb, KERN_INFO,
2023 "resized to %llu blocks",
2024 ext4_blocks_count(es));
2025 last_update_time = jiffies;
2026 }
2027 if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0)
2028 break;
2029 err = ext4_flex_group_add(sb, resize_inode, flex_gd);
2030 if (unlikely(err))
2031 break;
2032 }
2033
2034 if (!err && n_blocks_count_retry) {
2035 n_blocks_count = n_blocks_count_retry;
2036 n_blocks_count_retry = 0;
2037 free_flex_gd(flex_gd);
2038 flex_gd = NULL;
2039 goto retry;
2040 }
2041
2042 out:
2043 if (flex_gd)
2044 free_flex_gd(flex_gd);
2045 if (resize_inode != NULL)
2046 iput(resize_inode);
2047 ext4_msg(sb, KERN_INFO, "resized filesystem to %llu", n_blocks_count);
2048 return err;
2049 }
Linux with added FPC-III support