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
ext4_resize_begin(struct super_block * sb)19 int 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
ext4_resize_end(struct super_block * sb)42 void ext4_resize_end(struct super_block *sb)
43 {
44 clear_bit_unlock(EXT4_RESIZING, &EXT4_SB(sb)->s_resize_flags);
45 smp_mb__after_atomic();
46 }
47
ext4_meta_bg_first_group(struct super_block * sb,ext4_group_t group)48 static ext4_group_t ext4_meta_bg_first_group(struct super_block *sb,
49 ext4_group_t group) {
50 return (group >> EXT4_DESC_PER_BLOCK_BITS(sb)) <<
51 EXT4_DESC_PER_BLOCK_BITS(sb);
52 }
53
ext4_meta_bg_first_block_no(struct super_block * sb,ext4_group_t group)54 static ext4_fsblk_t ext4_meta_bg_first_block_no(struct super_block *sb,
55 ext4_group_t group) {
56 group = ext4_meta_bg_first_group(sb, group);
57 return ext4_group_first_block_no(sb, group);
58 }
59
ext4_group_overhead_blocks(struct super_block * sb,ext4_group_t group)60 static ext4_grpblk_t ext4_group_overhead_blocks(struct super_block *sb,
61 ext4_group_t group) {
62 ext4_grpblk_t overhead;
63 overhead = ext4_bg_num_gdb(sb, group);
64 if (ext4_bg_has_super(sb, group))
65 overhead += 1 +
66 le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
67 return overhead;
68 }
69
70 #define outside(b, first, last) ((b) < (first) || (b) >= (last))
71 #define inside(b, first, last) ((b) >= (first) && (b) < (last))
72
verify_group_input(struct super_block * sb,struct ext4_new_group_data * input)73 static int verify_group_input(struct super_block *sb,
74 struct ext4_new_group_data *input)
75 {
76 struct ext4_sb_info *sbi = EXT4_SB(sb);
77 struct ext4_super_block *es = sbi->s_es;
78 ext4_fsblk_t start = ext4_blocks_count(es);
79 ext4_fsblk_t end = start + input->blocks_count;
80 ext4_group_t group = input->group;
81 ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
82 unsigned overhead;
83 ext4_fsblk_t metaend;
84 struct buffer_head *bh = NULL;
85 ext4_grpblk_t free_blocks_count, offset;
86 int err = -EINVAL;
87
88 if (group != sbi->s_groups_count) {
89 ext4_warning(sb, "Cannot add at group %u (only %u groups)",
90 input->group, sbi->s_groups_count);
91 return -EINVAL;
92 }
93
94 overhead = ext4_group_overhead_blocks(sb, group);
95 metaend = start + overhead;
96 input->free_blocks_count = free_blocks_count =
97 input->blocks_count - 2 - overhead - sbi->s_itb_per_group;
98
99 if (test_opt(sb, DEBUG))
100 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks "
101 "(%d free, %u reserved)\n",
102 ext4_bg_has_super(sb, input->group) ? "normal" :
103 "no-super", input->group, input->blocks_count,
104 free_blocks_count, input->reserved_blocks);
105
106 ext4_get_group_no_and_offset(sb, start, NULL, &offset);
107 if (offset != 0)
108 ext4_warning(sb, "Last group not full");
109 else if (input->reserved_blocks > input->blocks_count / 5)
110 ext4_warning(sb, "Reserved blocks too high (%u)",
111 input->reserved_blocks);
112 else if (free_blocks_count < 0)
113 ext4_warning(sb, "Bad blocks count %u",
114 input->blocks_count);
115 else if (!(bh = sb_bread(sb, end - 1)))
116 ext4_warning(sb, "Cannot read last block (%llu)",
117 end - 1);
118 else if (outside(input->block_bitmap, start, end))
119 ext4_warning(sb, "Block bitmap not in group (block %llu)",
120 (unsigned long long)input->block_bitmap);
121 else if (outside(input->inode_bitmap, start, end))
122 ext4_warning(sb, "Inode bitmap not in group (block %llu)",
123 (unsigned long long)input->inode_bitmap);
124 else if (outside(input->inode_table, start, end) ||
125 outside(itend - 1, start, end))
126 ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)",
127 (unsigned long long)input->inode_table, itend - 1);
128 else if (input->inode_bitmap == input->block_bitmap)
129 ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)",
130 (unsigned long long)input->block_bitmap);
131 else if (inside(input->block_bitmap, input->inode_table, itend))
132 ext4_warning(sb, "Block bitmap (%llu) in inode table "
133 "(%llu-%llu)",
134 (unsigned long long)input->block_bitmap,
135 (unsigned long long)input->inode_table, itend - 1);
136 else if (inside(input->inode_bitmap, input->inode_table, itend))
137 ext4_warning(sb, "Inode bitmap (%llu) in inode table "
138 "(%llu-%llu)",
139 (unsigned long long)input->inode_bitmap,
140 (unsigned long long)input->inode_table, itend - 1);
141 else if (inside(input->block_bitmap, start, metaend))
142 ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)",
143 (unsigned long long)input->block_bitmap,
144 start, metaend - 1);
145 else if (inside(input->inode_bitmap, start, metaend))
146 ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)",
147 (unsigned long long)input->inode_bitmap,
148 start, metaend - 1);
149 else if (inside(input->inode_table, start, metaend) ||
150 inside(itend - 1, start, metaend))
151 ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table "
152 "(%llu-%llu)",
153 (unsigned long long)input->inode_table,
154 itend - 1, start, metaend - 1);
155 else
156 err = 0;
157 brelse(bh);
158
159 return err;
160 }
161
162 /*
163 * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex
164 * group each time.
165 */
166 struct ext4_new_flex_group_data {
167 struct ext4_new_group_data *groups; /* new_group_data for groups
168 in the flex group */
169 __u16 *bg_flags; /* block group flags of groups
170 in @groups */
171 ext4_group_t count; /* number of groups in @groups
172 */
173 };
174
175 /*
176 * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of
177 * @flexbg_size.
178 *
179 * Returns NULL on failure otherwise address of the allocated structure.
180 */
alloc_flex_gd(unsigned long flexbg_size)181 static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size)
182 {
183 struct ext4_new_flex_group_data *flex_gd;
184
185 flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS);
186 if (flex_gd == NULL)
187 goto out3;
188
189 if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_group_data))
190 goto out2;
191 flex_gd->count = flexbg_size;
192
193 flex_gd->groups = kmalloc(sizeof(struct ext4_new_group_data) *
194 flexbg_size, GFP_NOFS);
195 if (flex_gd->groups == NULL)
196 goto out2;
197
198 flex_gd->bg_flags = kmalloc(flexbg_size * sizeof(__u16), GFP_NOFS);
199 if (flex_gd->bg_flags == NULL)
200 goto out1;
201
202 return flex_gd;
203
204 out1:
205 kfree(flex_gd->groups);
206 out2:
207 kfree(flex_gd);
208 out3:
209 return NULL;
210 }
211
free_flex_gd(struct ext4_new_flex_group_data * flex_gd)212 static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd)
213 {
214 kfree(flex_gd->bg_flags);
215 kfree(flex_gd->groups);
216 kfree(flex_gd);
217 }
218
219 /*
220 * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps
221 * and inode tables for a flex group.
222 *
223 * This function is used by 64bit-resize. Note that this function allocates
224 * group tables from the 1st group of groups contained by @flexgd, which may
225 * be a partial of a flex group.
226 *
227 * @sb: super block of fs to which the groups belongs
228 *
229 * Returns 0 on a successful allocation of the metadata blocks in the
230 * block group.
231 */
ext4_alloc_group_tables(struct super_block * sb,struct ext4_new_flex_group_data * flex_gd,int flexbg_size)232 static int ext4_alloc_group_tables(struct super_block *sb,
233 struct ext4_new_flex_group_data *flex_gd,
234 int flexbg_size)
235 {
236 struct ext4_new_group_data *group_data = flex_gd->groups;
237 ext4_fsblk_t start_blk;
238 ext4_fsblk_t last_blk;
239 ext4_group_t src_group;
240 ext4_group_t bb_index = 0;
241 ext4_group_t ib_index = 0;
242 ext4_group_t it_index = 0;
243 ext4_group_t group;
244 ext4_group_t last_group;
245 unsigned overhead;
246 __u16 uninit_mask = (flexbg_size > 1) ? ~EXT4_BG_BLOCK_UNINIT : ~0;
247
248 BUG_ON(flex_gd->count == 0 || group_data == NULL);
249
250 src_group = group_data[0].group;
251 last_group = src_group + flex_gd->count - 1;
252
253 BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) !=
254 (last_group & ~(flexbg_size - 1))));
255 next_group:
256 group = group_data[0].group;
257 if (src_group >= group_data[0].group + flex_gd->count)
258 return -ENOSPC;
259 start_blk = ext4_group_first_block_no(sb, src_group);
260 last_blk = start_blk + group_data[src_group - group].blocks_count;
261
262 overhead = ext4_group_overhead_blocks(sb, src_group);
263
264 start_blk += overhead;
265
266 /* We collect contiguous blocks as much as possible. */
267 src_group++;
268 for (; src_group <= last_group; src_group++) {
269 overhead = ext4_group_overhead_blocks(sb, src_group);
270 if (overhead == 0)
271 last_blk += group_data[src_group - group].blocks_count;
272 else
273 break;
274 }
275
276 /* Allocate block bitmaps */
277 for (; bb_index < flex_gd->count; bb_index++) {
278 if (start_blk >= last_blk)
279 goto next_group;
280 group_data[bb_index].block_bitmap = start_blk++;
281 group = ext4_get_group_number(sb, start_blk - 1);
282 group -= group_data[0].group;
283 group_data[group].free_blocks_count--;
284 flex_gd->bg_flags[group] &= uninit_mask;
285 }
286
287 /* Allocate inode bitmaps */
288 for (; ib_index < flex_gd->count; ib_index++) {
289 if (start_blk >= last_blk)
290 goto next_group;
291 group_data[ib_index].inode_bitmap = start_blk++;
292 group = ext4_get_group_number(sb, start_blk - 1);
293 group -= group_data[0].group;
294 group_data[group].free_blocks_count--;
295 flex_gd->bg_flags[group] &= uninit_mask;
296 }
297
298 /* Allocate inode tables */
299 for (; it_index < flex_gd->count; it_index++) {
300 unsigned int itb = EXT4_SB(sb)->s_itb_per_group;
301 ext4_fsblk_t next_group_start;
302
303 if (start_blk + itb > last_blk)
304 goto next_group;
305 group_data[it_index].inode_table = start_blk;
306 group = ext4_get_group_number(sb, start_blk);
307 next_group_start = ext4_group_first_block_no(sb, group + 1);
308 group -= group_data[0].group;
309
310 if (start_blk + itb > next_group_start) {
311 flex_gd->bg_flags[group + 1] &= uninit_mask;
312 overhead = start_blk + itb - next_group_start;
313 group_data[group + 1].free_blocks_count -= overhead;
314 itb -= overhead;
315 }
316
317 group_data[group].free_blocks_count -= itb;
318 flex_gd->bg_flags[group] &= uninit_mask;
319 start_blk += EXT4_SB(sb)->s_itb_per_group;
320 }
321
322 if (test_opt(sb, DEBUG)) {
323 int i;
324 group = group_data[0].group;
325
326 printk(KERN_DEBUG "EXT4-fs: adding a flex group with "
327 "%d groups, flexbg size is %d:\n", flex_gd->count,
328 flexbg_size);
329
330 for (i = 0; i < flex_gd->count; i++) {
331 printk(KERN_DEBUG "adding %s group %u: %u "
332 "blocks (%d free)\n",
333 ext4_bg_has_super(sb, group + i) ? "normal" :
334 "no-super", group + i,
335 group_data[i].blocks_count,
336 group_data[i].free_blocks_count);
337 }
338 }
339 return 0;
340 }
341
bclean(handle_t * handle,struct super_block * sb,ext4_fsblk_t blk)342 static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
343 ext4_fsblk_t blk)
344 {
345 struct buffer_head *bh;
346 int err;
347
348 bh = sb_getblk(sb, blk);
349 if (unlikely(!bh))
350 return ERR_PTR(-ENOMEM);
351 BUFFER_TRACE(bh, "get_write_access");
352 if ((err = ext4_journal_get_write_access(handle, bh))) {
353 brelse(bh);
354 bh = ERR_PTR(err);
355 } else {
356 memset(bh->b_data, 0, sb->s_blocksize);
357 set_buffer_uptodate(bh);
358 }
359
360 return bh;
361 }
362
363 /*
364 * If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA.
365 * If that fails, restart the transaction & regain write access for the
366 * buffer head which is used for block_bitmap modifications.
367 */
extend_or_restart_transaction(handle_t * handle,int thresh)368 static int extend_or_restart_transaction(handle_t *handle, int thresh)
369 {
370 int err;
371
372 if (ext4_handle_has_enough_credits(handle, thresh))
373 return 0;
374
375 err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA);
376 if (err < 0)
377 return err;
378 if (err) {
379 err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA);
380 if (err)
381 return err;
382 }
383
384 return 0;
385 }
386
387 /*
388 * set_flexbg_block_bitmap() mark @count blocks starting from @block used.
389 *
390 * Helper function for ext4_setup_new_group_blocks() which set .
391 *
392 * @sb: super block
393 * @handle: journal handle
394 * @flex_gd: flex group data
395 */
set_flexbg_block_bitmap(struct super_block * sb,handle_t * handle,struct ext4_new_flex_group_data * flex_gd,ext4_fsblk_t block,ext4_group_t count)396 static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle,
397 struct ext4_new_flex_group_data *flex_gd,
398 ext4_fsblk_t block, ext4_group_t count)
399 {
400 ext4_group_t count2;
401
402 ext4_debug("mark blocks [%llu/%u] used\n", block, count);
403 for (count2 = count; count > 0; count -= count2, block += count2) {
404 ext4_fsblk_t start;
405 struct buffer_head *bh;
406 ext4_group_t group;
407 int err;
408
409 group = ext4_get_group_number(sb, block);
410 start = ext4_group_first_block_no(sb, group);
411 group -= flex_gd->groups[0].group;
412
413 count2 = EXT4_BLOCKS_PER_GROUP(sb) - (block - start);
414 if (count2 > count)
415 count2 = count;
416
417 if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) {
418 BUG_ON(flex_gd->count > 1);
419 continue;
420 }
421
422 err = extend_or_restart_transaction(handle, 1);
423 if (err)
424 return err;
425
426 bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap);
427 if (unlikely(!bh))
428 return -ENOMEM;
429
430 BUFFER_TRACE(bh, "get_write_access");
431 err = ext4_journal_get_write_access(handle, bh);
432 if (err)
433 return err;
434 ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n", block,
435 block - start, count2);
436 ext4_set_bits(bh->b_data, block - start, count2);
437
438 err = ext4_handle_dirty_metadata(handle, NULL, bh);
439 if (unlikely(err))
440 return err;
441 brelse(bh);
442 }
443
444 return 0;
445 }
446
447 /*
448 * Set up the block and inode bitmaps, and the inode table for the new groups.
449 * This doesn't need to be part of the main transaction, since we are only
450 * changing blocks outside the actual filesystem. We still do journaling to
451 * ensure the recovery is correct in case of a failure just after resize.
452 * If any part of this fails, we simply abort the resize.
453 *
454 * setup_new_flex_group_blocks handles a flex group as follow:
455 * 1. copy super block and GDT, and initialize group tables if necessary.
456 * In this step, we only set bits in blocks bitmaps for blocks taken by
457 * super block and GDT.
458 * 2. allocate group tables in block bitmaps, that is, set bits in block
459 * bitmap for blocks taken by group tables.
460 */
setup_new_flex_group_blocks(struct super_block * sb,struct ext4_new_flex_group_data * flex_gd)461 static int setup_new_flex_group_blocks(struct super_block *sb,
462 struct ext4_new_flex_group_data *flex_gd)
463 {
464 int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group};
465 ext4_fsblk_t start;
466 ext4_fsblk_t block;
467 struct ext4_sb_info *sbi = EXT4_SB(sb);
468 struct ext4_super_block *es = sbi->s_es;
469 struct ext4_new_group_data *group_data = flex_gd->groups;
470 __u16 *bg_flags = flex_gd->bg_flags;
471 handle_t *handle;
472 ext4_group_t group, count;
473 struct buffer_head *bh = NULL;
474 int reserved_gdb, i, j, err = 0, err2;
475 int meta_bg;
476
477 BUG_ON(!flex_gd->count || !group_data ||
478 group_data[0].group != sbi->s_groups_count);
479
480 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
481 meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG);
482
483 /* This transaction may be extended/restarted along the way */
484 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA);
485 if (IS_ERR(handle))
486 return PTR_ERR(handle);
487
488 group = group_data[0].group;
489 for (i = 0; i < flex_gd->count; i++, group++) {
490 unsigned long gdblocks;
491 ext4_grpblk_t overhead;
492
493 gdblocks = ext4_bg_num_gdb(sb, group);
494 start = ext4_group_first_block_no(sb, group);
495
496 if (meta_bg == 0 && !ext4_bg_has_super(sb, group))
497 goto handle_itb;
498
499 if (meta_bg == 1) {
500 ext4_group_t first_group;
501 first_group = ext4_meta_bg_first_group(sb, group);
502 if (first_group != group + 1 &&
503 first_group != group + EXT4_DESC_PER_BLOCK(sb) - 1)
504 goto handle_itb;
505 }
506
507 block = start + ext4_bg_has_super(sb, group);
508 /* Copy all of the GDT blocks into the backup in this group */
509 for (j = 0; j < gdblocks; j++, block++) {
510 struct buffer_head *gdb;
511
512 ext4_debug("update backup group %#04llx\n", block);
513 err = extend_or_restart_transaction(handle, 1);
514 if (err)
515 goto out;
516
517 gdb = sb_getblk(sb, block);
518 if (unlikely(!gdb)) {
519 err = -ENOMEM;
520 goto out;
521 }
522
523 BUFFER_TRACE(gdb, "get_write_access");
524 err = ext4_journal_get_write_access(handle, gdb);
525 if (err) {
526 brelse(gdb);
527 goto out;
528 }
529 memcpy(gdb->b_data, sbi->s_group_desc[j]->b_data,
530 gdb->b_size);
531 set_buffer_uptodate(gdb);
532
533 err = ext4_handle_dirty_metadata(handle, NULL, gdb);
534 if (unlikely(err)) {
535 brelse(gdb);
536 goto out;
537 }
538 brelse(gdb);
539 }
540
541 /* Zero out all of the reserved backup group descriptor
542 * table blocks
543 */
544 if (ext4_bg_has_super(sb, group)) {
545 err = sb_issue_zeroout(sb, gdblocks + start + 1,
546 reserved_gdb, GFP_NOFS);
547 if (err)
548 goto out;
549 }
550
551 handle_itb:
552 /* Initialize group tables of the grop @group */
553 if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED))
554 goto handle_bb;
555
556 /* Zero out all of the inode table blocks */
557 block = group_data[i].inode_table;
558 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n",
559 block, sbi->s_itb_per_group);
560 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group,
561 GFP_NOFS);
562 if (err)
563 goto out;
564
565 handle_bb:
566 if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT)
567 goto handle_ib;
568
569 /* Initialize block bitmap of the @group */
570 block = group_data[i].block_bitmap;
571 err = extend_or_restart_transaction(handle, 1);
572 if (err)
573 goto out;
574
575 bh = bclean(handle, sb, block);
576 if (IS_ERR(bh)) {
577 err = PTR_ERR(bh);
578 bh = NULL;
579 goto out;
580 }
581 overhead = ext4_group_overhead_blocks(sb, group);
582 if (overhead != 0) {
583 ext4_debug("mark backup superblock %#04llx (+0)\n",
584 start);
585 ext4_set_bits(bh->b_data, 0, overhead);
586 }
587 ext4_mark_bitmap_end(group_data[i].blocks_count,
588 sb->s_blocksize * 8, bh->b_data);
589 err = ext4_handle_dirty_metadata(handle, NULL, bh);
590 if (err)
591 goto out;
592 brelse(bh);
593
594 handle_ib:
595 if (bg_flags[i] & EXT4_BG_INODE_UNINIT)
596 continue;
597
598 /* Initialize inode bitmap of the @group */
599 block = group_data[i].inode_bitmap;
600 err = extend_or_restart_transaction(handle, 1);
601 if (err)
602 goto out;
603 /* Mark unused entries in inode bitmap used */
604 bh = bclean(handle, sb, block);
605 if (IS_ERR(bh)) {
606 err = PTR_ERR(bh);
607 bh = NULL;
608 goto out;
609 }
610
611 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
612 sb->s_blocksize * 8, bh->b_data);
613 err = ext4_handle_dirty_metadata(handle, NULL, bh);
614 if (err)
615 goto out;
616 brelse(bh);
617 }
618 bh = NULL;
619
620 /* Mark group tables in block bitmap */
621 for (j = 0; j < GROUP_TABLE_COUNT; j++) {
622 count = group_table_count[j];
623 start = (&group_data[0].block_bitmap)[j];
624 block = start;
625 for (i = 1; i < flex_gd->count; i++) {
626 block += group_table_count[j];
627 if (block == (&group_data[i].block_bitmap)[j]) {
628 count += group_table_count[j];
629 continue;
630 }
631 err = set_flexbg_block_bitmap(sb, handle,
632 flex_gd, start, count);
633 if (err)
634 goto out;
635 count = group_table_count[j];
636 start = (&group_data[i].block_bitmap)[j];
637 block = start;
638 }
639
640 if (count) {
641 err = set_flexbg_block_bitmap(sb, handle,
642 flex_gd, start, count);
643 if (err)
644 goto out;
645 }
646 }
647
648 out:
649 brelse(bh);
650 err2 = ext4_journal_stop(handle);
651 if (err2 && !err)
652 err = err2;
653
654 return err;
655 }
656
657 /*
658 * Iterate through the groups which hold BACKUP superblock/GDT copies in an
659 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
660 * calling this for the first time. In a sparse filesystem it will be the
661 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
662 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
663 */
ext4_list_backups(struct super_block * sb,unsigned * three,unsigned * five,unsigned * seven)664 static unsigned ext4_list_backups(struct super_block *sb, unsigned *three,
665 unsigned *five, unsigned *seven)
666 {
667 unsigned *min = three;
668 int mult = 3;
669 unsigned ret;
670
671 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
672 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
673 ret = *min;
674 *min += 1;
675 return ret;
676 }
677
678 if (*five < *min) {
679 min = five;
680 mult = 5;
681 }
682 if (*seven < *min) {
683 min = seven;
684 mult = 7;
685 }
686
687 ret = *min;
688 *min *= mult;
689
690 return ret;
691 }
692
693 /*
694 * Check that all of the backup GDT blocks are held in the primary GDT block.
695 * It is assumed that they are stored in group order. Returns the number of
696 * groups in current filesystem that have BACKUPS, or -ve error code.
697 */
verify_reserved_gdb(struct super_block * sb,ext4_group_t end,struct buffer_head * primary)698 static int verify_reserved_gdb(struct super_block *sb,
699 ext4_group_t end,
700 struct buffer_head *primary)
701 {
702 const ext4_fsblk_t blk = primary->b_blocknr;
703 unsigned three = 1;
704 unsigned five = 5;
705 unsigned seven = 7;
706 unsigned grp;
707 __le32 *p = (__le32 *)primary->b_data;
708 int gdbackups = 0;
709
710 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) {
711 if (le32_to_cpu(*p++) !=
712 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){
713 ext4_warning(sb, "reserved GDT %llu"
714 " missing grp %d (%llu)",
715 blk, grp,
716 grp *
717 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
718 blk);
719 return -EINVAL;
720 }
721 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb))
722 return -EFBIG;
723 }
724
725 return gdbackups;
726 }
727
728 /*
729 * Called when we need to bring a reserved group descriptor table block into
730 * use from the resize inode. The primary copy of the new GDT block currently
731 * is an indirect block (under the double indirect block in the resize inode).
732 * The new backup GDT blocks will be stored as leaf blocks in this indirect
733 * block, in group order. Even though we know all the block numbers we need,
734 * we check to ensure that the resize inode has actually reserved these blocks.
735 *
736 * Don't need to update the block bitmaps because the blocks are still in use.
737 *
738 * We get all of the error cases out of the way, so that we are sure to not
739 * fail once we start modifying the data on disk, because JBD has no rollback.
740 */
add_new_gdb(handle_t * handle,struct inode * inode,ext4_group_t group)741 static int add_new_gdb(handle_t *handle, struct inode *inode,
742 ext4_group_t group)
743 {
744 struct super_block *sb = inode->i_sb;
745 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
746 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
747 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
748 struct buffer_head **o_group_desc, **n_group_desc;
749 struct buffer_head *dind;
750 struct buffer_head *gdb_bh;
751 int gdbackups;
752 struct ext4_iloc iloc;
753 __le32 *data;
754 int err;
755
756 if (test_opt(sb, DEBUG))
757 printk(KERN_DEBUG
758 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
759 gdb_num);
760
761 /*
762 * If we are not using the primary superblock/GDT copy don't resize,
763 * because the user tools have no way of handling this. Probably a
764 * bad time to do it anyways.
765 */
766 if (EXT4_SB(sb)->s_sbh->b_blocknr !=
767 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
768 ext4_warning(sb, "won't resize using backup superblock at %llu",
769 (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
770 return -EPERM;
771 }
772
773 gdb_bh = sb_bread(sb, gdblock);
774 if (!gdb_bh)
775 return -EIO;
776
777 gdbackups = verify_reserved_gdb(sb, group, gdb_bh);
778 if (gdbackups < 0) {
779 err = gdbackups;
780 goto exit_bh;
781 }
782
783 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
784 dind = sb_bread(sb, le32_to_cpu(*data));
785 if (!dind) {
786 err = -EIO;
787 goto exit_bh;
788 }
789
790 data = (__le32 *)dind->b_data;
791 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) {
792 ext4_warning(sb, "new group %u GDT block %llu not reserved",
793 group, gdblock);
794 err = -EINVAL;
795 goto exit_dind;
796 }
797
798 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
799 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
800 if (unlikely(err))
801 goto exit_dind;
802
803 BUFFER_TRACE(gdb_bh, "get_write_access");
804 err = ext4_journal_get_write_access(handle, gdb_bh);
805 if (unlikely(err))
806 goto exit_dind;
807
808 BUFFER_TRACE(dind, "get_write_access");
809 err = ext4_journal_get_write_access(handle, dind);
810 if (unlikely(err))
811 ext4_std_error(sb, err);
812
813 /* ext4_reserve_inode_write() gets a reference on the iloc */
814 err = ext4_reserve_inode_write(handle, inode, &iloc);
815 if (unlikely(err))
816 goto exit_dind;
817
818 n_group_desc = ext4_kvmalloc((gdb_num + 1) *
819 sizeof(struct buffer_head *),
820 GFP_NOFS);
821 if (!n_group_desc) {
822 err = -ENOMEM;
823 ext4_warning(sb, "not enough memory for %lu groups",
824 gdb_num + 1);
825 goto exit_inode;
826 }
827
828 /*
829 * Finally, we have all of the possible failures behind us...
830 *
831 * Remove new GDT block from inode double-indirect block and clear out
832 * the new GDT block for use (which also "frees" the backup GDT blocks
833 * from the reserved inode). We don't need to change the bitmaps for
834 * these blocks, because they are marked as in-use from being in the
835 * reserved inode, and will become GDT blocks (primary and backup).
836 */
837 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0;
838 err = ext4_handle_dirty_metadata(handle, NULL, dind);
839 if (unlikely(err)) {
840 ext4_std_error(sb, err);
841 goto exit_inode;
842 }
843 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9;
844 ext4_mark_iloc_dirty(handle, inode, &iloc);
845 memset(gdb_bh->b_data, 0, sb->s_blocksize);
846 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
847 if (unlikely(err)) {
848 ext4_std_error(sb, err);
849 goto exit_inode;
850 }
851 brelse(dind);
852
853 o_group_desc = EXT4_SB(sb)->s_group_desc;
854 memcpy(n_group_desc, o_group_desc,
855 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
856 n_group_desc[gdb_num] = gdb_bh;
857 EXT4_SB(sb)->s_group_desc = n_group_desc;
858 EXT4_SB(sb)->s_gdb_count++;
859 ext4_kvfree(o_group_desc);
860
861 le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
862 err = ext4_handle_dirty_super(handle, sb);
863 if (err)
864 ext4_std_error(sb, err);
865
866 return err;
867
868 exit_inode:
869 ext4_kvfree(n_group_desc);
870 brelse(iloc.bh);
871 exit_dind:
872 brelse(dind);
873 exit_bh:
874 brelse(gdb_bh);
875
876 ext4_debug("leaving with error %d\n", err);
877 return err;
878 }
879
880 /*
881 * add_new_gdb_meta_bg is the sister of add_new_gdb.
882 */
add_new_gdb_meta_bg(struct super_block * sb,handle_t * handle,ext4_group_t group)883 static int add_new_gdb_meta_bg(struct super_block *sb,
884 handle_t *handle, ext4_group_t group) {
885 ext4_fsblk_t gdblock;
886 struct buffer_head *gdb_bh;
887 struct buffer_head **o_group_desc, **n_group_desc;
888 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
889 int err;
890
891 gdblock = ext4_meta_bg_first_block_no(sb, group) +
892 ext4_bg_has_super(sb, group);
893 gdb_bh = sb_bread(sb, gdblock);
894 if (!gdb_bh)
895 return -EIO;
896 n_group_desc = ext4_kvmalloc((gdb_num + 1) *
897 sizeof(struct buffer_head *),
898 GFP_NOFS);
899 if (!n_group_desc) {
900 err = -ENOMEM;
901 ext4_warning(sb, "not enough memory for %lu groups",
902 gdb_num + 1);
903 return err;
904 }
905
906 o_group_desc = EXT4_SB(sb)->s_group_desc;
907 memcpy(n_group_desc, o_group_desc,
908 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
909 n_group_desc[gdb_num] = gdb_bh;
910 EXT4_SB(sb)->s_group_desc = n_group_desc;
911 EXT4_SB(sb)->s_gdb_count++;
912 ext4_kvfree(o_group_desc);
913 BUFFER_TRACE(gdb_bh, "get_write_access");
914 err = ext4_journal_get_write_access(handle, gdb_bh);
915 if (unlikely(err))
916 brelse(gdb_bh);
917 return err;
918 }
919
920 /*
921 * Called when we are adding a new group which has a backup copy of each of
922 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
923 * We need to add these reserved backup GDT blocks to the resize inode, so
924 * that they are kept for future resizing and not allocated to files.
925 *
926 * Each reserved backup GDT block will go into a different indirect block.
927 * The indirect blocks are actually the primary reserved GDT blocks,
928 * so we know in advance what their block numbers are. We only get the
929 * double-indirect block to verify it is pointing to the primary reserved
930 * GDT blocks so we don't overwrite a data block by accident. The reserved
931 * backup GDT blocks are stored in their reserved primary GDT block.
932 */
reserve_backup_gdb(handle_t * handle,struct inode * inode,ext4_group_t group)933 static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
934 ext4_group_t group)
935 {
936 struct super_block *sb = inode->i_sb;
937 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
938 struct buffer_head **primary;
939 struct buffer_head *dind;
940 struct ext4_iloc iloc;
941 ext4_fsblk_t blk;
942 __le32 *data, *end;
943 int gdbackups = 0;
944 int res, i;
945 int err;
946
947 primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS);
948 if (!primary)
949 return -ENOMEM;
950
951 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
952 dind = sb_bread(sb, le32_to_cpu(*data));
953 if (!dind) {
954 err = -EIO;
955 goto exit_free;
956 }
957
958 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count;
959 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count %
960 EXT4_ADDR_PER_BLOCK(sb));
961 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb);
962
963 /* Get each reserved primary GDT block and verify it holds backups */
964 for (res = 0; res < reserved_gdb; res++, blk++) {
965 if (le32_to_cpu(*data) != blk) {
966 ext4_warning(sb, "reserved block %llu"
967 " not at offset %ld",
968 blk,
969 (long)(data - (__le32 *)dind->b_data));
970 err = -EINVAL;
971 goto exit_bh;
972 }
973 primary[res] = sb_bread(sb, blk);
974 if (!primary[res]) {
975 err = -EIO;
976 goto exit_bh;
977 }
978 gdbackups = verify_reserved_gdb(sb, group, primary[res]);
979 if (gdbackups < 0) {
980 brelse(primary[res]);
981 err = gdbackups;
982 goto exit_bh;
983 }
984 if (++data >= end)
985 data = (__le32 *)dind->b_data;
986 }
987
988 for (i = 0; i < reserved_gdb; i++) {
989 BUFFER_TRACE(primary[i], "get_write_access");
990 if ((err = ext4_journal_get_write_access(handle, primary[i])))
991 goto exit_bh;
992 }
993
994 if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
995 goto exit_bh;
996
997 /*
998 * Finally we can add each of the reserved backup GDT blocks from
999 * the new group to its reserved primary GDT block.
1000 */
1001 blk = group * EXT4_BLOCKS_PER_GROUP(sb);
1002 for (i = 0; i < reserved_gdb; i++) {
1003 int err2;
1004 data = (__le32 *)primary[i]->b_data;
1005 /* printk("reserving backup %lu[%u] = %lu\n",
1006 primary[i]->b_blocknr, gdbackups,
1007 blk + primary[i]->b_blocknr); */
1008 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
1009 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]);
1010 if (!err)
1011 err = err2;
1012 }
1013 inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9;
1014 ext4_mark_iloc_dirty(handle, inode, &iloc);
1015
1016 exit_bh:
1017 while (--res >= 0)
1018 brelse(primary[res]);
1019 brelse(dind);
1020
1021 exit_free:
1022 kfree(primary);
1023
1024 return err;
1025 }
1026
1027 /*
1028 * Update the backup copies of the ext4 metadata. These don't need to be part
1029 * of the main resize transaction, because e2fsck will re-write them if there
1030 * is a problem (basically only OOM will cause a problem). However, we
1031 * _should_ update the backups if possible, in case the primary gets trashed
1032 * for some reason and we need to run e2fsck from a backup superblock. The
1033 * important part is that the new block and inode counts are in the backup
1034 * superblocks, and the location of the new group metadata in the GDT backups.
1035 *
1036 * We do not need take the s_resize_lock for this, because these
1037 * blocks are not otherwise touched by the filesystem code when it is
1038 * mounted. We don't need to worry about last changing from
1039 * sbi->s_groups_count, because the worst that can happen is that we
1040 * do not copy the full number of backups at this time. The resize
1041 * which changed s_groups_count will backup again.
1042 */
update_backups(struct super_block * sb,int blk_off,char * data,int size,int meta_bg)1043 static void update_backups(struct super_block *sb, int blk_off, char *data,
1044 int size, int meta_bg)
1045 {
1046 struct ext4_sb_info *sbi = EXT4_SB(sb);
1047 ext4_group_t last;
1048 const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
1049 unsigned three = 1;
1050 unsigned five = 5;
1051 unsigned seven = 7;
1052 ext4_group_t group = 0;
1053 int rest = sb->s_blocksize - size;
1054 handle_t *handle;
1055 int err = 0, err2;
1056
1057 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA);
1058 if (IS_ERR(handle)) {
1059 group = 1;
1060 err = PTR_ERR(handle);
1061 goto exit_err;
1062 }
1063
1064 if (meta_bg == 0) {
1065 group = ext4_list_backups(sb, &three, &five, &seven);
1066 last = sbi->s_groups_count;
1067 } else {
1068 group = ext4_meta_bg_first_group(sb, group) + 1;
1069 last = (ext4_group_t)(group + EXT4_DESC_PER_BLOCK(sb) - 2);
1070 }
1071
1072 while (group < sbi->s_groups_count) {
1073 struct buffer_head *bh;
1074 ext4_fsblk_t backup_block;
1075
1076 /* Out of journal space, and can't get more - abort - so sad */
1077 if (ext4_handle_valid(handle) &&
1078 handle->h_buffer_credits == 0 &&
1079 ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA) &&
1080 (err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
1081 break;
1082
1083 if (meta_bg == 0)
1084 backup_block = ((ext4_fsblk_t)group) * bpg + blk_off;
1085 else
1086 backup_block = (ext4_group_first_block_no(sb, group) +
1087 ext4_bg_has_super(sb, group));
1088
1089 bh = sb_getblk(sb, backup_block);
1090 if (unlikely(!bh)) {
1091 err = -ENOMEM;
1092 break;
1093 }
1094 ext4_debug("update metadata backup %llu(+%llu)\n",
1095 backup_block, backup_block -
1096 ext4_group_first_block_no(sb, group));
1097 BUFFER_TRACE(bh, "get_write_access");
1098 if ((err = ext4_journal_get_write_access(handle, bh)))
1099 break;
1100 lock_buffer(bh);
1101 memcpy(bh->b_data, data, size);
1102 if (rest)
1103 memset(bh->b_data + size, 0, rest);
1104 set_buffer_uptodate(bh);
1105 unlock_buffer(bh);
1106 err = ext4_handle_dirty_metadata(handle, NULL, bh);
1107 if (unlikely(err))
1108 ext4_std_error(sb, err);
1109 brelse(bh);
1110
1111 if (meta_bg == 0)
1112 group = ext4_list_backups(sb, &three, &five, &seven);
1113 else if (group == last)
1114 break;
1115 else
1116 group = last;
1117 }
1118 if ((err2 = ext4_journal_stop(handle)) && !err)
1119 err = err2;
1120
1121 /*
1122 * Ugh! Need to have e2fsck write the backup copies. It is too
1123 * late to revert the resize, we shouldn't fail just because of
1124 * the backup copies (they are only needed in case of corruption).
1125 *
1126 * However, if we got here we have a journal problem too, so we
1127 * can't really start a transaction to mark the superblock.
1128 * Chicken out and just set the flag on the hope it will be written
1129 * to disk, and if not - we will simply wait until next fsck.
1130 */
1131 exit_err:
1132 if (err) {
1133 ext4_warning(sb, "can't update backup for group %u (err %d), "
1134 "forcing fsck on next reboot", group, err);
1135 sbi->s_mount_state &= ~EXT4_VALID_FS;
1136 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1137 mark_buffer_dirty(sbi->s_sbh);
1138 }
1139 }
1140
1141 /*
1142 * ext4_add_new_descs() adds @count group descriptor of groups
1143 * starting at @group
1144 *
1145 * @handle: journal handle
1146 * @sb: super block
1147 * @group: the group no. of the first group desc to be added
1148 * @resize_inode: the resize inode
1149 * @count: number of group descriptors to be added
1150 */
ext4_add_new_descs(handle_t * handle,struct super_block * sb,ext4_group_t group,struct inode * resize_inode,ext4_group_t count)1151 static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
1152 ext4_group_t group, struct inode *resize_inode,
1153 ext4_group_t count)
1154 {
1155 struct ext4_sb_info *sbi = EXT4_SB(sb);
1156 struct ext4_super_block *es = sbi->s_es;
1157 struct buffer_head *gdb_bh;
1158 int i, gdb_off, gdb_num, err = 0;
1159 int meta_bg;
1160
1161 meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG);
1162 for (i = 0; i < count; i++, group++) {
1163 int reserved_gdb = ext4_bg_has_super(sb, group) ?
1164 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
1165
1166 gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
1167 gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1168
1169 /*
1170 * We will only either add reserved group blocks to a backup group
1171 * or remove reserved blocks for the first group in a new group block.
1172 * Doing both would be mean more complex code, and sane people don't
1173 * use non-sparse filesystems anymore. This is already checked above.
1174 */
1175 if (gdb_off) {
1176 gdb_bh = sbi->s_group_desc[gdb_num];
1177 BUFFER_TRACE(gdb_bh, "get_write_access");
1178 err = ext4_journal_get_write_access(handle, gdb_bh);
1179
1180 if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group))
1181 err = reserve_backup_gdb(handle, resize_inode, group);
1182 } else if (meta_bg != 0) {
1183 err = add_new_gdb_meta_bg(sb, handle, group);
1184 } else {
1185 err = add_new_gdb(handle, resize_inode, group);
1186 }
1187 if (err)
1188 break;
1189 }
1190 return err;
1191 }
1192
ext4_get_bitmap(struct super_block * sb,__u64 block)1193 static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block)
1194 {
1195 struct buffer_head *bh = sb_getblk(sb, block);
1196 if (unlikely(!bh))
1197 return NULL;
1198 if (!bh_uptodate_or_lock(bh)) {
1199 if (bh_submit_read(bh) < 0) {
1200 brelse(bh);
1201 return NULL;
1202 }
1203 }
1204
1205 return bh;
1206 }
1207
ext4_set_bitmap_checksums(struct super_block * sb,ext4_group_t group,struct ext4_group_desc * gdp,struct ext4_new_group_data * group_data)1208 static int ext4_set_bitmap_checksums(struct super_block *sb,
1209 ext4_group_t group,
1210 struct ext4_group_desc *gdp,
1211 struct ext4_new_group_data *group_data)
1212 {
1213 struct buffer_head *bh;
1214
1215 if (!ext4_has_metadata_csum(sb))
1216 return 0;
1217
1218 bh = ext4_get_bitmap(sb, group_data->inode_bitmap);
1219 if (!bh)
1220 return -EIO;
1221 ext4_inode_bitmap_csum_set(sb, group, gdp, bh,
1222 EXT4_INODES_PER_GROUP(sb) / 8);
1223 brelse(bh);
1224
1225 bh = ext4_get_bitmap(sb, group_data->block_bitmap);
1226 if (!bh)
1227 return -EIO;
1228 ext4_block_bitmap_csum_set(sb, group, gdp, bh);
1229 brelse(bh);
1230
1231 return 0;
1232 }
1233
1234 /*
1235 * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg
1236 */
ext4_setup_new_descs(handle_t * handle,struct super_block * sb,struct ext4_new_flex_group_data * flex_gd)1237 static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb,
1238 struct ext4_new_flex_group_data *flex_gd)
1239 {
1240 struct ext4_new_group_data *group_data = flex_gd->groups;
1241 struct ext4_group_desc *gdp;
1242 struct ext4_sb_info *sbi = EXT4_SB(sb);
1243 struct buffer_head *gdb_bh;
1244 ext4_group_t group;
1245 __u16 *bg_flags = flex_gd->bg_flags;
1246 int i, gdb_off, gdb_num, err = 0;
1247
1248
1249 for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) {
1250 group = group_data->group;
1251
1252 gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
1253 gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1254
1255 /*
1256 * get_write_access() has been called on gdb_bh by ext4_add_new_desc().
1257 */
1258 gdb_bh = sbi->s_group_desc[gdb_num];
1259 /* Update group descriptor block for new group */
1260 gdp = (struct ext4_group_desc *)(gdb_bh->b_data +
1261 gdb_off * EXT4_DESC_SIZE(sb));
1262
1263 memset(gdp, 0, EXT4_DESC_SIZE(sb));
1264 ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap);
1265 ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap);
1266 err = ext4_set_bitmap_checksums(sb, group, gdp, group_data);
1267 if (err) {
1268 ext4_std_error(sb, err);
1269 break;
1270 }
1271
1272 ext4_inode_table_set(sb, gdp, group_data->inode_table);
1273 ext4_free_group_clusters_set(sb, gdp,
1274 EXT4_NUM_B2C(sbi, group_data->free_blocks_count));
1275 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
1276 if (ext4_has_group_desc_csum(sb))
1277 ext4_itable_unused_set(sb, gdp,
1278 EXT4_INODES_PER_GROUP(sb));
1279 gdp->bg_flags = cpu_to_le16(*bg_flags);
1280 ext4_group_desc_csum_set(sb, group, gdp);
1281
1282 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
1283 if (unlikely(err)) {
1284 ext4_std_error(sb, err);
1285 break;
1286 }
1287
1288 /*
1289 * We can allocate memory for mb_alloc based on the new group
1290 * descriptor
1291 */
1292 err = ext4_mb_add_groupinfo(sb, group, gdp);
1293 if (err)
1294 break;
1295 }
1296 return err;
1297 }
1298
1299 /*
1300 * ext4_update_super() updates the super block so that the newly added
1301 * groups can be seen by the filesystem.
1302 *
1303 * @sb: super block
1304 * @flex_gd: new added groups
1305 */
ext4_update_super(struct super_block * sb,struct ext4_new_flex_group_data * flex_gd)1306 static void ext4_update_super(struct super_block *sb,
1307 struct ext4_new_flex_group_data *flex_gd)
1308 {
1309 ext4_fsblk_t blocks_count = 0;
1310 ext4_fsblk_t free_blocks = 0;
1311 ext4_fsblk_t reserved_blocks = 0;
1312 struct ext4_new_group_data *group_data = flex_gd->groups;
1313 struct ext4_sb_info *sbi = EXT4_SB(sb);
1314 struct ext4_super_block *es = sbi->s_es;
1315 int i;
1316
1317 BUG_ON(flex_gd->count == 0 || group_data == NULL);
1318 /*
1319 * Make the new blocks and inodes valid next. We do this before
1320 * increasing the group count so that once the group is enabled,
1321 * all of its blocks and inodes are already valid.
1322 *
1323 * We always allocate group-by-group, then block-by-block or
1324 * inode-by-inode within a group, so enabling these
1325 * blocks/inodes before the group is live won't actually let us
1326 * allocate the new space yet.
1327 */
1328 for (i = 0; i < flex_gd->count; i++) {
1329 blocks_count += group_data[i].blocks_count;
1330 free_blocks += group_data[i].free_blocks_count;
1331 }
1332
1333 reserved_blocks = ext4_r_blocks_count(es) * 100;
1334 reserved_blocks = div64_u64(reserved_blocks, ext4_blocks_count(es));
1335 reserved_blocks *= blocks_count;
1336 do_div(reserved_blocks, 100);
1337
1338 ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count);
1339 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks);
1340 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) *
1341 flex_gd->count);
1342 le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) *
1343 flex_gd->count);
1344
1345 ext4_debug("free blocks count %llu", ext4_free_blocks_count(es));
1346 /*
1347 * We need to protect s_groups_count against other CPUs seeing
1348 * inconsistent state in the superblock.
1349 *
1350 * The precise rules we use are:
1351 *
1352 * * Writers must perform a smp_wmb() after updating all
1353 * dependent data and before modifying the groups count
1354 *
1355 * * Readers must perform an smp_rmb() after reading the groups
1356 * count and before reading any dependent data.
1357 *
1358 * NB. These rules can be relaxed when checking the group count
1359 * while freeing data, as we can only allocate from a block
1360 * group after serialising against the group count, and we can
1361 * only then free after serialising in turn against that
1362 * allocation.
1363 */
1364 smp_wmb();
1365
1366 /* Update the global fs size fields */
1367 sbi->s_groups_count += flex_gd->count;
1368 sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
1369 (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
1370
1371 /* Update the reserved block counts only once the new group is
1372 * active. */
1373 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) +
1374 reserved_blocks);
1375
1376 /* Update the free space counts */
1377 percpu_counter_add(&sbi->s_freeclusters_counter,
1378 EXT4_NUM_B2C(sbi, free_blocks));
1379 percpu_counter_add(&sbi->s_freeinodes_counter,
1380 EXT4_INODES_PER_GROUP(sb) * flex_gd->count);
1381
1382 ext4_debug("free blocks count %llu",
1383 percpu_counter_read(&sbi->s_freeclusters_counter));
1384 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
1385 EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
1386 sbi->s_log_groups_per_flex) {
1387 ext4_group_t flex_group;
1388 flex_group = ext4_flex_group(sbi, group_data[0].group);
1389 atomic64_add(EXT4_NUM_B2C(sbi, free_blocks),
1390 &sbi->s_flex_groups[flex_group].free_clusters);
1391 atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count,
1392 &sbi->s_flex_groups[flex_group].free_inodes);
1393 }
1394
1395 /*
1396 * Update the fs overhead information
1397 */
1398 ext4_calculate_overhead(sb);
1399
1400 if (test_opt(sb, DEBUG))
1401 printk(KERN_DEBUG "EXT4-fs: added group %u:"
1402 "%llu blocks(%llu free %llu reserved)\n", flex_gd->count,
1403 blocks_count, free_blocks, reserved_blocks);
1404 }
1405
1406 /* Add a flex group to an fs. Ensure we handle all possible error conditions
1407 * _before_ we start modifying the filesystem, because we cannot abort the
1408 * transaction and not have it write the data to disk.
1409 */
ext4_flex_group_add(struct super_block * sb,struct inode * resize_inode,struct ext4_new_flex_group_data * flex_gd)1410 static int ext4_flex_group_add(struct super_block *sb,
1411 struct inode *resize_inode,
1412 struct ext4_new_flex_group_data *flex_gd)
1413 {
1414 struct ext4_sb_info *sbi = EXT4_SB(sb);
1415 struct ext4_super_block *es = sbi->s_es;
1416 ext4_fsblk_t o_blocks_count;
1417 ext4_grpblk_t last;
1418 ext4_group_t group;
1419 handle_t *handle;
1420 unsigned reserved_gdb;
1421 int err = 0, err2 = 0, credit;
1422
1423 BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags);
1424
1425 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
1426 o_blocks_count = ext4_blocks_count(es);
1427 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1428 BUG_ON(last);
1429
1430 err = setup_new_flex_group_blocks(sb, flex_gd);
1431 if (err)
1432 goto exit;
1433 /*
1434 * We will always be modifying at least the superblock and GDT
1435 * block. If we are adding a group past the last current GDT block,
1436 * we will also modify the inode and the dindirect block. If we
1437 * are adding a group with superblock/GDT backups we will also
1438 * modify each of the reserved GDT dindirect blocks.
1439 */
1440 credit = flex_gd->count * 4 + reserved_gdb;
1441 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credit);
1442 if (IS_ERR(handle)) {
1443 err = PTR_ERR(handle);
1444 goto exit;
1445 }
1446
1447 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
1448 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
1449 if (err)
1450 goto exit_journal;
1451
1452 group = flex_gd->groups[0].group;
1453 BUG_ON(group != EXT4_SB(sb)->s_groups_count);
1454 err = ext4_add_new_descs(handle, sb, group,
1455 resize_inode, flex_gd->count);
1456 if (err)
1457 goto exit_journal;
1458
1459 err = ext4_setup_new_descs(handle, sb, flex_gd);
1460 if (err)
1461 goto exit_journal;
1462
1463 ext4_update_super(sb, flex_gd);
1464
1465 err = ext4_handle_dirty_super(handle, sb);
1466
1467 exit_journal:
1468 err2 = ext4_journal_stop(handle);
1469 if (!err)
1470 err = err2;
1471
1472 if (!err) {
1473 int gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1474 int gdb_num_end = ((group + flex_gd->count - 1) /
1475 EXT4_DESC_PER_BLOCK(sb));
1476 int meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb,
1477 EXT4_FEATURE_INCOMPAT_META_BG);
1478 sector_t old_gdb = 0;
1479
1480 update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
1481 sizeof(struct ext4_super_block), 0);
1482 for (; gdb_num <= gdb_num_end; gdb_num++) {
1483 struct buffer_head *gdb_bh;
1484
1485 gdb_bh = sbi->s_group_desc[gdb_num];
1486 if (old_gdb == gdb_bh->b_blocknr)
1487 continue;
1488 update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data,
1489 gdb_bh->b_size, meta_bg);
1490 old_gdb = gdb_bh->b_blocknr;
1491 }
1492 }
1493 exit:
1494 return err;
1495 }
1496
ext4_setup_next_flex_gd(struct super_block * sb,struct ext4_new_flex_group_data * flex_gd,ext4_fsblk_t n_blocks_count,unsigned long flexbg_size)1497 static int ext4_setup_next_flex_gd(struct super_block *sb,
1498 struct ext4_new_flex_group_data *flex_gd,
1499 ext4_fsblk_t n_blocks_count,
1500 unsigned long flexbg_size)
1501 {
1502 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1503 struct ext4_new_group_data *group_data = flex_gd->groups;
1504 ext4_fsblk_t o_blocks_count;
1505 ext4_group_t n_group;
1506 ext4_group_t group;
1507 ext4_group_t last_group;
1508 ext4_grpblk_t last;
1509 ext4_grpblk_t blocks_per_group;
1510 unsigned long i;
1511
1512 blocks_per_group = EXT4_BLOCKS_PER_GROUP(sb);
1513
1514 o_blocks_count = ext4_blocks_count(es);
1515
1516 if (o_blocks_count == n_blocks_count)
1517 return 0;
1518
1519 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1520 BUG_ON(last);
1521 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last);
1522
1523 last_group = group | (flexbg_size - 1);
1524 if (last_group > n_group)
1525 last_group = n_group;
1526
1527 flex_gd->count = last_group - group + 1;
1528
1529 for (i = 0; i < flex_gd->count; i++) {
1530 int overhead;
1531
1532 group_data[i].group = group + i;
1533 group_data[i].blocks_count = blocks_per_group;
1534 overhead = ext4_group_overhead_blocks(sb, group + i);
1535 group_data[i].free_blocks_count = blocks_per_group - overhead;
1536 if (ext4_has_group_desc_csum(sb)) {
1537 flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT |
1538 EXT4_BG_INODE_UNINIT;
1539 if (!test_opt(sb, INIT_INODE_TABLE))
1540 flex_gd->bg_flags[i] |= EXT4_BG_INODE_ZEROED;
1541 } else
1542 flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED;
1543 }
1544
1545 if (last_group == n_group && ext4_has_group_desc_csum(sb))
1546 /* We need to initialize block bitmap of last group. */
1547 flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT;
1548
1549 if ((last_group == n_group) && (last != blocks_per_group - 1)) {
1550 group_data[i - 1].blocks_count = last + 1;
1551 group_data[i - 1].free_blocks_count -= blocks_per_group-
1552 last - 1;
1553 }
1554
1555 return 1;
1556 }
1557
1558 /* Add group descriptor data to an existing or new group descriptor block.
1559 * Ensure we handle all possible error conditions _before_ we start modifying
1560 * the filesystem, because we cannot abort the transaction and not have it
1561 * write the data to disk.
1562 *
1563 * If we are on a GDT block boundary, we need to get the reserved GDT block.
1564 * Otherwise, we may need to add backup GDT blocks for a sparse group.
1565 *
1566 * We only need to hold the superblock lock while we are actually adding
1567 * in the new group's counts to the superblock. Prior to that we have
1568 * not really "added" the group at all. We re-check that we are still
1569 * adding in the last group in case things have changed since verifying.
1570 */
ext4_group_add(struct super_block * sb,struct ext4_new_group_data * input)1571 int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
1572 {
1573 struct ext4_new_flex_group_data flex_gd;
1574 struct ext4_sb_info *sbi = EXT4_SB(sb);
1575 struct ext4_super_block *es = sbi->s_es;
1576 int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
1577 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
1578 struct inode *inode = NULL;
1579 int gdb_off;
1580 int err;
1581 __u16 bg_flags = 0;
1582
1583 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb);
1584
1585 if (gdb_off == 0 && !EXT4_HAS_RO_COMPAT_FEATURE(sb,
1586 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
1587 ext4_warning(sb, "Can't resize non-sparse filesystem further");
1588 return -EPERM;
1589 }
1590
1591 if (ext4_blocks_count(es) + input->blocks_count <
1592 ext4_blocks_count(es)) {
1593 ext4_warning(sb, "blocks_count overflow");
1594 return -EINVAL;
1595 }
1596
1597 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) <
1598 le32_to_cpu(es->s_inodes_count)) {
1599 ext4_warning(sb, "inodes_count overflow");
1600 return -EINVAL;
1601 }
1602
1603 if (reserved_gdb || gdb_off == 0) {
1604 if (!EXT4_HAS_COMPAT_FEATURE(sb,
1605 EXT4_FEATURE_COMPAT_RESIZE_INODE)
1606 || !le16_to_cpu(es->s_reserved_gdt_blocks)) {
1607 ext4_warning(sb,
1608 "No reserved GDT blocks, can't resize");
1609 return -EPERM;
1610 }
1611 inode = ext4_iget(sb, EXT4_RESIZE_INO);
1612 if (IS_ERR(inode)) {
1613 ext4_warning(sb, "Error opening resize inode");
1614 return PTR_ERR(inode);
1615 }
1616 }
1617
1618
1619 err = verify_group_input(sb, input);
1620 if (err)
1621 goto out;
1622
1623 err = ext4_alloc_flex_bg_array(sb, input->group + 1);
1624 if (err)
1625 goto out;
1626
1627 err = ext4_mb_alloc_groupinfo(sb, input->group + 1);
1628 if (err)
1629 goto out;
1630
1631 flex_gd.count = 1;
1632 flex_gd.groups = input;
1633 flex_gd.bg_flags = &bg_flags;
1634 err = ext4_flex_group_add(sb, inode, &flex_gd);
1635 out:
1636 iput(inode);
1637 return err;
1638 } /* ext4_group_add */
1639
1640 /*
1641 * extend a group without checking assuming that checking has been done.
1642 */
ext4_group_extend_no_check(struct super_block * sb,ext4_fsblk_t o_blocks_count,ext4_grpblk_t add)1643 static int ext4_group_extend_no_check(struct super_block *sb,
1644 ext4_fsblk_t o_blocks_count, ext4_grpblk_t add)
1645 {
1646 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1647 handle_t *handle;
1648 int err = 0, err2;
1649
1650 /* We will update the superblock, one block bitmap, and
1651 * one group descriptor via ext4_group_add_blocks().
1652 */
1653 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, 3);
1654 if (IS_ERR(handle)) {
1655 err = PTR_ERR(handle);
1656 ext4_warning(sb, "error %d on journal start", err);
1657 return err;
1658 }
1659
1660 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
1661 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
1662 if (err) {
1663 ext4_warning(sb, "error %d on journal write access", err);
1664 goto errout;
1665 }
1666
1667 ext4_blocks_count_set(es, o_blocks_count + add);
1668 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add);
1669 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
1670 o_blocks_count + add);
1671 /* We add the blocks to the bitmap and set the group need init bit */
1672 err = ext4_group_add_blocks(handle, sb, o_blocks_count, add);
1673 if (err)
1674 goto errout;
1675 ext4_handle_dirty_super(handle, sb);
1676 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
1677 o_blocks_count + add);
1678 errout:
1679 err2 = ext4_journal_stop(handle);
1680 if (err2 && !err)
1681 err = err2;
1682
1683 if (!err) {
1684 if (test_opt(sb, DEBUG))
1685 printk(KERN_DEBUG "EXT4-fs: extended group to %llu "
1686 "blocks\n", ext4_blocks_count(es));
1687 update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr,
1688 (char *)es, sizeof(struct ext4_super_block), 0);
1689 }
1690 return err;
1691 }
1692
1693 /*
1694 * Extend the filesystem to the new number of blocks specified. This entry
1695 * point is only used to extend the current filesystem to the end of the last
1696 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>"
1697 * for emergencies (because it has no dependencies on reserved blocks).
1698 *
1699 * If we _really_ wanted, we could use default values to call ext4_group_add()
1700 * allow the "remount" trick to work for arbitrary resizing, assuming enough
1701 * GDT blocks are reserved to grow to the desired size.
1702 */
ext4_group_extend(struct super_block * sb,struct ext4_super_block * es,ext4_fsblk_t n_blocks_count)1703 int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
1704 ext4_fsblk_t n_blocks_count)
1705 {
1706 ext4_fsblk_t o_blocks_count;
1707 ext4_grpblk_t last;
1708 ext4_grpblk_t add;
1709 struct buffer_head *bh;
1710 int err;
1711 ext4_group_t group;
1712
1713 o_blocks_count = ext4_blocks_count(es);
1714
1715 if (test_opt(sb, DEBUG))
1716 ext4_msg(sb, KERN_DEBUG,
1717 "extending last group from %llu to %llu blocks",
1718 o_blocks_count, n_blocks_count);
1719
1720 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
1721 return 0;
1722
1723 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1724 ext4_msg(sb, KERN_ERR,
1725 "filesystem too large to resize to %llu blocks safely",
1726 n_blocks_count);
1727 if (sizeof(sector_t) < 8)
1728 ext4_warning(sb, "CONFIG_LBDAF not enabled");
1729 return -EINVAL;
1730 }
1731
1732 if (n_blocks_count < o_blocks_count) {
1733 ext4_warning(sb, "can't shrink FS - resize aborted");
1734 return -EINVAL;
1735 }
1736
1737 /* Handle the remaining blocks in the last group only. */
1738 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1739
1740 if (last == 0) {
1741 ext4_warning(sb, "need to use ext2online to resize further");
1742 return -EPERM;
1743 }
1744
1745 add = EXT4_BLOCKS_PER_GROUP(sb) - last;
1746
1747 if (o_blocks_count + add < o_blocks_count) {
1748 ext4_warning(sb, "blocks_count overflow");
1749 return -EINVAL;
1750 }
1751
1752 if (o_blocks_count + add > n_blocks_count)
1753 add = n_blocks_count - o_blocks_count;
1754
1755 if (o_blocks_count + add < n_blocks_count)
1756 ext4_warning(sb, "will only finish group (%llu blocks, %u new)",
1757 o_blocks_count + add, add);
1758
1759 /* See if the device is actually as big as what was requested */
1760 bh = sb_bread(sb, o_blocks_count + add - 1);
1761 if (!bh) {
1762 ext4_warning(sb, "can't read last block, resize aborted");
1763 return -ENOSPC;
1764 }
1765 brelse(bh);
1766
1767 err = ext4_group_extend_no_check(sb, o_blocks_count, add);
1768 return err;
1769 } /* ext4_group_extend */
1770
1771
num_desc_blocks(struct super_block * sb,ext4_group_t groups)1772 static int num_desc_blocks(struct super_block *sb, ext4_group_t groups)
1773 {
1774 return (groups + EXT4_DESC_PER_BLOCK(sb) - 1) / EXT4_DESC_PER_BLOCK(sb);
1775 }
1776
1777 /*
1778 * Release the resize inode and drop the resize_inode feature if there
1779 * are no more reserved gdt blocks, and then convert the file system
1780 * to enable meta_bg
1781 */
ext4_convert_meta_bg(struct super_block * sb,struct inode * inode)1782 static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode)
1783 {
1784 handle_t *handle;
1785 struct ext4_sb_info *sbi = EXT4_SB(sb);
1786 struct ext4_super_block *es = sbi->s_es;
1787 struct ext4_inode_info *ei = EXT4_I(inode);
1788 ext4_fsblk_t nr;
1789 int i, ret, err = 0;
1790 int credits = 1;
1791
1792 ext4_msg(sb, KERN_INFO, "Converting file system to meta_bg");
1793 if (inode) {
1794 if (es->s_reserved_gdt_blocks) {
1795 ext4_error(sb, "Unexpected non-zero "
1796 "s_reserved_gdt_blocks");
1797 return -EPERM;
1798 }
1799
1800 /* Do a quick sanity check of the resize inode */
1801 if (inode->i_blocks != 1 << (inode->i_blkbits - 9))
1802 goto invalid_resize_inode;
1803 for (i = 0; i < EXT4_N_BLOCKS; i++) {
1804 if (i == EXT4_DIND_BLOCK) {
1805 if (ei->i_data[i])
1806 continue;
1807 else
1808 goto invalid_resize_inode;
1809 }
1810 if (ei->i_data[i])
1811 goto invalid_resize_inode;
1812 }
1813 credits += 3; /* block bitmap, bg descriptor, resize inode */
1814 }
1815
1816 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credits);
1817 if (IS_ERR(handle))
1818 return PTR_ERR(handle);
1819
1820 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
1821 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
1822 if (err)
1823 goto errout;
1824
1825 EXT4_CLEAR_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE);
1826 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG);
1827 sbi->s_es->s_first_meta_bg =
1828 cpu_to_le32(num_desc_blocks(sb, sbi->s_groups_count));
1829
1830 err = ext4_handle_dirty_super(handle, sb);
1831 if (err) {
1832 ext4_std_error(sb, err);
1833 goto errout;
1834 }
1835
1836 if (inode) {
1837 nr = le32_to_cpu(ei->i_data[EXT4_DIND_BLOCK]);
1838 ext4_free_blocks(handle, inode, NULL, nr, 1,
1839 EXT4_FREE_BLOCKS_METADATA |
1840 EXT4_FREE_BLOCKS_FORGET);
1841 ei->i_data[EXT4_DIND_BLOCK] = 0;
1842 inode->i_blocks = 0;
1843
1844 err = ext4_mark_inode_dirty(handle, inode);
1845 if (err)
1846 ext4_std_error(sb, err);
1847 }
1848
1849 errout:
1850 ret = ext4_journal_stop(handle);
1851 if (!err)
1852 err = ret;
1853 return ret;
1854
1855 invalid_resize_inode:
1856 ext4_error(sb, "corrupted/inconsistent resize inode");
1857 return -EINVAL;
1858 }
1859
1860 /*
1861 * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count
1862 *
1863 * @sb: super block of the fs to be resized
1864 * @n_blocks_count: the number of blocks resides in the resized fs
1865 */
ext4_resize_fs(struct super_block * sb,ext4_fsblk_t n_blocks_count)1866 int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
1867 {
1868 struct ext4_new_flex_group_data *flex_gd = NULL;
1869 struct ext4_sb_info *sbi = EXT4_SB(sb);
1870 struct ext4_super_block *es = sbi->s_es;
1871 struct buffer_head *bh;
1872 struct inode *resize_inode = NULL;
1873 ext4_grpblk_t add, offset;
1874 unsigned long n_desc_blocks;
1875 unsigned long o_desc_blocks;
1876 ext4_group_t o_group;
1877 ext4_group_t n_group;
1878 ext4_fsblk_t o_blocks_count;
1879 ext4_fsblk_t n_blocks_count_retry = 0;
1880 unsigned long last_update_time = 0;
1881 int err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex;
1882 int meta_bg;
1883
1884 /* See if the device is actually as big as what was requested */
1885 bh = sb_bread(sb, n_blocks_count - 1);
1886 if (!bh) {
1887 ext4_warning(sb, "can't read last block, resize aborted");
1888 return -ENOSPC;
1889 }
1890 brelse(bh);
1891
1892 retry:
1893 o_blocks_count = ext4_blocks_count(es);
1894
1895 ext4_msg(sb, KERN_INFO, "resizing filesystem from %llu "
1896 "to %llu blocks", o_blocks_count, n_blocks_count);
1897
1898 if (n_blocks_count < o_blocks_count) {
1899 /* On-line shrinking not supported */
1900 ext4_warning(sb, "can't shrink FS - resize aborted");
1901 return -EINVAL;
1902 }
1903
1904 if (n_blocks_count == o_blocks_count)
1905 /* Nothing need to do */
1906 return 0;
1907
1908 n_group = ext4_get_group_number(sb, n_blocks_count - 1);
1909 if (n_group > (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) {
1910 ext4_warning(sb, "resize would cause inodes_count overflow");
1911 return -EINVAL;
1912 }
1913 ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset);
1914
1915 n_desc_blocks = num_desc_blocks(sb, n_group + 1);
1916 o_desc_blocks = num_desc_blocks(sb, sbi->s_groups_count);
1917
1918 meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG);
1919
1920 if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE)) {
1921 if (meta_bg) {
1922 ext4_error(sb, "resize_inode and meta_bg enabled "
1923 "simultaneously");
1924 return -EINVAL;
1925 }
1926 if (n_desc_blocks > o_desc_blocks +
1927 le16_to_cpu(es->s_reserved_gdt_blocks)) {
1928 n_blocks_count_retry = n_blocks_count;
1929 n_desc_blocks = o_desc_blocks +
1930 le16_to_cpu(es->s_reserved_gdt_blocks);
1931 n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb);
1932 n_blocks_count = (ext4_fsblk_t)n_group *
1933 EXT4_BLOCKS_PER_GROUP(sb);
1934 n_group--; /* set to last group number */
1935 }
1936
1937 if (!resize_inode)
1938 resize_inode = ext4_iget(sb, EXT4_RESIZE_INO);
1939 if (IS_ERR(resize_inode)) {
1940 ext4_warning(sb, "Error opening resize inode");
1941 return PTR_ERR(resize_inode);
1942 }
1943 }
1944
1945 if ((!resize_inode && !meta_bg) || n_blocks_count == o_blocks_count) {
1946 err = ext4_convert_meta_bg(sb, resize_inode);
1947 if (err)
1948 goto out;
1949 if (resize_inode) {
1950 iput(resize_inode);
1951 resize_inode = NULL;
1952 }
1953 if (n_blocks_count_retry) {
1954 n_blocks_count = n_blocks_count_retry;
1955 n_blocks_count_retry = 0;
1956 goto retry;
1957 }
1958 }
1959
1960 /* extend the last group */
1961 if (n_group == o_group)
1962 add = n_blocks_count - o_blocks_count;
1963 else
1964 add = EXT4_BLOCKS_PER_GROUP(sb) - (offset + 1);
1965 if (add > 0) {
1966 err = ext4_group_extend_no_check(sb, o_blocks_count, add);
1967 if (err)
1968 goto out;
1969 }
1970
1971 if (ext4_blocks_count(es) == n_blocks_count)
1972 goto out;
1973
1974 err = ext4_alloc_flex_bg_array(sb, n_group + 1);
1975 if (err)
1976 return err;
1977
1978 err = ext4_mb_alloc_groupinfo(sb, n_group + 1);
1979 if (err)
1980 goto out;
1981
1982 flex_gd = alloc_flex_gd(flexbg_size);
1983 if (flex_gd == NULL) {
1984 err = -ENOMEM;
1985 goto out;
1986 }
1987
1988 /* Add flex groups. Note that a regular group is a
1989 * flex group with 1 group.
1990 */
1991 while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count,
1992 flexbg_size)) {
1993 if (jiffies - last_update_time > HZ * 10) {
1994 if (last_update_time)
1995 ext4_msg(sb, KERN_INFO,
1996 "resized to %llu blocks",
1997 ext4_blocks_count(es));
1998 last_update_time = jiffies;
1999 }
2000 if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0)
2001 break;
2002 err = ext4_flex_group_add(sb, resize_inode, flex_gd);
2003 if (unlikely(err))
2004 break;
2005 }
2006
2007 if (!err && n_blocks_count_retry) {
2008 n_blocks_count = n_blocks_count_retry;
2009 n_blocks_count_retry = 0;
2010 free_flex_gd(flex_gd);
2011 flex_gd = NULL;
2012 goto retry;
2013 }
2014
2015 out:
2016 if (flex_gd)
2017 free_flex_gd(flex_gd);
2018 if (resize_inode != NULL)
2019 iput(resize_inode);
2020 ext4_msg(sb, KERN_INFO, "resized filesystem to %llu", n_blocks_count);
2021 return err;
2022 }
2023