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1// SPDX-License-Identifier: LGPL-2.1
2/*
3 * Copyright IBM Corporation, 2007
4 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
5 *
6 */
7
8#include <linux/slab.h>
9#include "ext4_jbd2.h"
10#include "ext4_extents.h"
11
12/*
13 * The contiguous blocks details which can be
14 * represented by a single extent
15 */
16struct migrate_struct {
17 ext4_lblk_t first_block, last_block, curr_block;
18 ext4_fsblk_t first_pblock, last_pblock;
19};
20
21static int finish_range(handle_t *handle, struct inode *inode,
22 struct migrate_struct *lb)
23
24{
25 int retval = 0, needed;
26 struct ext4_extent newext;
27 struct ext4_ext_path *path;
28 if (lb->first_pblock == 0)
29 return 0;
30
31 /* Add the extent to temp inode*/
32 newext.ee_block = cpu_to_le32(lb->first_block);
33 newext.ee_len = cpu_to_le16(lb->last_block - lb->first_block + 1);
34 ext4_ext_store_pblock(&newext, lb->first_pblock);
35 /* Locking only for convenience since we are operating on temp inode */
36 down_write(&EXT4_I(inode)->i_data_sem);
37 path = ext4_find_extent(inode, lb->first_block, NULL, 0);
38 if (IS_ERR(path)) {
39 retval = PTR_ERR(path);
40 goto err_out;
41 }
42
43 /*
44 * Calculate the credit needed to inserting this extent
45 * Since we are doing this in loop we may accumulate extra
46 * credit. But below we try to not accumulate too much
47 * of them by restarting the journal.
48 */
49 needed = ext4_ext_calc_credits_for_single_extent(inode,
50 lb->last_block - lb->first_block + 1, path);
51
52 retval = ext4_datasem_ensure_credits(handle, inode, needed, needed, 0);
53 if (retval < 0)
54 goto err_out;
55 path = ext4_ext_insert_extent(handle, inode, path, &newext, 0);
56 if (IS_ERR(path))
57 retval = PTR_ERR(path);
58err_out:
59 up_write((&EXT4_I(inode)->i_data_sem));
60 ext4_free_ext_path(path);
61 lb->first_pblock = 0;
62 return retval;
63}
64
65static int update_extent_range(handle_t *handle, struct inode *inode,
66 ext4_fsblk_t pblock, struct migrate_struct *lb)
67{
68 int retval;
69 /*
70 * See if we can add on to the existing range (if it exists)
71 */
72 if (lb->first_pblock &&
73 (lb->last_pblock+1 == pblock) &&
74 (lb->last_block+1 == lb->curr_block)) {
75 lb->last_pblock = pblock;
76 lb->last_block = lb->curr_block;
77 lb->curr_block++;
78 return 0;
79 }
80 /*
81 * Start a new range.
82 */
83 retval = finish_range(handle, inode, lb);
84 lb->first_pblock = lb->last_pblock = pblock;
85 lb->first_block = lb->last_block = lb->curr_block;
86 lb->curr_block++;
87 return retval;
88}
89
90static int update_ind_extent_range(handle_t *handle, struct inode *inode,
91 ext4_fsblk_t pblock,
92 struct migrate_struct *lb)
93{
94 struct buffer_head *bh;
95 __le32 *i_data;
96 int i, retval = 0;
97 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
98
99 bh = ext4_sb_bread(inode->i_sb, pblock, 0);
100 if (IS_ERR(bh))
101 return PTR_ERR(bh);
102
103 i_data = (__le32 *)bh->b_data;
104 for (i = 0; i < max_entries; i++) {
105 if (i_data[i]) {
106 retval = update_extent_range(handle, inode,
107 le32_to_cpu(i_data[i]), lb);
108 if (retval)
109 break;
110 } else {
111 lb->curr_block++;
112 }
113 }
114 put_bh(bh);
115 return retval;
116
117}
118
119static int update_dind_extent_range(handle_t *handle, struct inode *inode,
120 ext4_fsblk_t pblock,
121 struct migrate_struct *lb)
122{
123 struct buffer_head *bh;
124 __le32 *i_data;
125 int i, retval = 0;
126 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
127
128 bh = ext4_sb_bread(inode->i_sb, pblock, 0);
129 if (IS_ERR(bh))
130 return PTR_ERR(bh);
131
132 i_data = (__le32 *)bh->b_data;
133 for (i = 0; i < max_entries; i++) {
134 if (i_data[i]) {
135 retval = update_ind_extent_range(handle, inode,
136 le32_to_cpu(i_data[i]), lb);
137 if (retval)
138 break;
139 } else {
140 /* Only update the file block number */
141 lb->curr_block += max_entries;
142 }
143 }
144 put_bh(bh);
145 return retval;
146
147}
148
149static int update_tind_extent_range(handle_t *handle, struct inode *inode,
150 ext4_fsblk_t pblock,
151 struct migrate_struct *lb)
152{
153 struct buffer_head *bh;
154 __le32 *i_data;
155 int i, retval = 0;
156 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
157
158 bh = ext4_sb_bread(inode->i_sb, pblock, 0);
159 if (IS_ERR(bh))
160 return PTR_ERR(bh);
161
162 i_data = (__le32 *)bh->b_data;
163 for (i = 0; i < max_entries; i++) {
164 if (i_data[i]) {
165 retval = update_dind_extent_range(handle, inode,
166 le32_to_cpu(i_data[i]), lb);
167 if (retval)
168 break;
169 } else {
170 /* Only update the file block number */
171 lb->curr_block += max_entries * max_entries;
172 }
173 }
174 put_bh(bh);
175 return retval;
176
177}
178
179static int free_dind_blocks(handle_t *handle,
180 struct inode *inode, __le32 i_data)
181{
182 int i;
183 __le32 *tmp_idata;
184 struct buffer_head *bh;
185 struct super_block *sb = inode->i_sb;
186 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
187 int err;
188
189 bh = ext4_sb_bread(sb, le32_to_cpu(i_data), 0);
190 if (IS_ERR(bh))
191 return PTR_ERR(bh);
192
193 tmp_idata = (__le32 *)bh->b_data;
194 for (i = 0; i < max_entries; i++) {
195 if (tmp_idata[i]) {
196 err = ext4_journal_ensure_credits(handle,
197 EXT4_RESERVE_TRANS_BLOCKS,
198 ext4_free_metadata_revoke_credits(sb, 1));
199 if (err < 0) {
200 put_bh(bh);
201 return err;
202 }
203 ext4_free_blocks(handle, inode, NULL,
204 le32_to_cpu(tmp_idata[i]), 1,
205 EXT4_FREE_BLOCKS_METADATA |
206 EXT4_FREE_BLOCKS_FORGET);
207 }
208 }
209 put_bh(bh);
210 err = ext4_journal_ensure_credits(handle, EXT4_RESERVE_TRANS_BLOCKS,
211 ext4_free_metadata_revoke_credits(sb, 1));
212 if (err < 0)
213 return err;
214 ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1,
215 EXT4_FREE_BLOCKS_METADATA |
216 EXT4_FREE_BLOCKS_FORGET);
217 return 0;
218}
219
220static int free_tind_blocks(handle_t *handle,
221 struct inode *inode, __le32 i_data)
222{
223 int i, retval = 0;
224 __le32 *tmp_idata;
225 struct buffer_head *bh;
226 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
227
228 bh = ext4_sb_bread(inode->i_sb, le32_to_cpu(i_data), 0);
229 if (IS_ERR(bh))
230 return PTR_ERR(bh);
231
232 tmp_idata = (__le32 *)bh->b_data;
233 for (i = 0; i < max_entries; i++) {
234 if (tmp_idata[i]) {
235 retval = free_dind_blocks(handle,
236 inode, tmp_idata[i]);
237 if (retval) {
238 put_bh(bh);
239 return retval;
240 }
241 }
242 }
243 put_bh(bh);
244 retval = ext4_journal_ensure_credits(handle, EXT4_RESERVE_TRANS_BLOCKS,
245 ext4_free_metadata_revoke_credits(inode->i_sb, 1));
246 if (retval < 0)
247 return retval;
248 ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1,
249 EXT4_FREE_BLOCKS_METADATA |
250 EXT4_FREE_BLOCKS_FORGET);
251 return 0;
252}
253
254static int free_ind_block(handle_t *handle, struct inode *inode, __le32 *i_data)
255{
256 int retval;
257
258 /* ei->i_data[EXT4_IND_BLOCK] */
259 if (i_data[0]) {
260 retval = ext4_journal_ensure_credits(handle,
261 EXT4_RESERVE_TRANS_BLOCKS,
262 ext4_free_metadata_revoke_credits(inode->i_sb, 1));
263 if (retval < 0)
264 return retval;
265 ext4_free_blocks(handle, inode, NULL,
266 le32_to_cpu(i_data[0]), 1,
267 EXT4_FREE_BLOCKS_METADATA |
268 EXT4_FREE_BLOCKS_FORGET);
269 }
270
271 /* ei->i_data[EXT4_DIND_BLOCK] */
272 if (i_data[1]) {
273 retval = free_dind_blocks(handle, inode, i_data[1]);
274 if (retval)
275 return retval;
276 }
277
278 /* ei->i_data[EXT4_TIND_BLOCK] */
279 if (i_data[2]) {
280 retval = free_tind_blocks(handle, inode, i_data[2]);
281 if (retval)
282 return retval;
283 }
284 return 0;
285}
286
287static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
288 struct inode *tmp_inode)
289{
290 int retval, retval2 = 0;
291 __le32 i_data[3];
292 struct ext4_inode_info *ei = EXT4_I(inode);
293 struct ext4_inode_info *tmp_ei = EXT4_I(tmp_inode);
294
295 /*
296 * One credit accounted for writing the
297 * i_data field of the original inode
298 */
299 retval = ext4_journal_ensure_credits(handle, 1, 0);
300 if (retval < 0)
301 goto err_out;
302
303 i_data[0] = ei->i_data[EXT4_IND_BLOCK];
304 i_data[1] = ei->i_data[EXT4_DIND_BLOCK];
305 i_data[2] = ei->i_data[EXT4_TIND_BLOCK];
306
307 down_write(&EXT4_I(inode)->i_data_sem);
308 /*
309 * if EXT4_STATE_EXT_MIGRATE is cleared a block allocation
310 * happened after we started the migrate. We need to
311 * fail the migrate
312 */
313 if (!ext4_test_inode_state(inode, EXT4_STATE_EXT_MIGRATE)) {
314 retval = -EAGAIN;
315 up_write(&EXT4_I(inode)->i_data_sem);
316 goto err_out;
317 } else
318 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
319 /*
320 * We have the extent map build with the tmp inode.
321 * Now copy the i_data across
322 */
323 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
324 memcpy(ei->i_data, tmp_ei->i_data, sizeof(ei->i_data));
325
326 /*
327 * Update i_blocks with the new blocks that got
328 * allocated while adding extents for extent index
329 * blocks.
330 *
331 * While converting to extents we need not
332 * update the original inode i_blocks for extent blocks
333 * via quota APIs. The quota update happened via tmp_inode already.
334 */
335 spin_lock(&inode->i_lock);
336 inode->i_blocks += tmp_inode->i_blocks;
337 spin_unlock(&inode->i_lock);
338 up_write(&EXT4_I(inode)->i_data_sem);
339
340 /*
341 * We mark the inode dirty after, because we decrement the
342 * i_blocks when freeing the indirect meta-data blocks
343 */
344 retval = free_ind_block(handle, inode, i_data);
345 retval2 = ext4_mark_inode_dirty(handle, inode);
346 if (unlikely(retval2 && !retval))
347 retval = retval2;
348
349err_out:
350 return retval;
351}
352
353static int free_ext_idx(handle_t *handle, struct inode *inode,
354 struct ext4_extent_idx *ix)
355{
356 int i, retval = 0;
357 ext4_fsblk_t block;
358 struct buffer_head *bh;
359 struct ext4_extent_header *eh;
360
361 block = ext4_idx_pblock(ix);
362 bh = ext4_sb_bread(inode->i_sb, block, 0);
363 if (IS_ERR(bh))
364 return PTR_ERR(bh);
365
366 eh = (struct ext4_extent_header *)bh->b_data;
367 if (eh->eh_depth != 0) {
368 ix = EXT_FIRST_INDEX(eh);
369 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
370 retval = free_ext_idx(handle, inode, ix);
371 if (retval) {
372 put_bh(bh);
373 return retval;
374 }
375 }
376 }
377 put_bh(bh);
378 retval = ext4_journal_ensure_credits(handle, EXT4_RESERVE_TRANS_BLOCKS,
379 ext4_free_metadata_revoke_credits(inode->i_sb, 1));
380 if (retval < 0)
381 return retval;
382 ext4_free_blocks(handle, inode, NULL, block, 1,
383 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
384 return 0;
385}
386
387/*
388 * Free the extent meta data blocks only
389 */
390static int free_ext_block(handle_t *handle, struct inode *inode)
391{
392 int i, retval = 0;
393 struct ext4_inode_info *ei = EXT4_I(inode);
394 struct ext4_extent_header *eh = (struct ext4_extent_header *)ei->i_data;
395 struct ext4_extent_idx *ix;
396 if (eh->eh_depth == 0)
397 /*
398 * No extra blocks allocated for extent meta data
399 */
400 return 0;
401 ix = EXT_FIRST_INDEX(eh);
402 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
403 retval = free_ext_idx(handle, inode, ix);
404 if (retval)
405 return retval;
406 }
407 return retval;
408}
409
410int ext4_ext_migrate(struct inode *inode)
411{
412 handle_t *handle;
413 int retval = 0, i;
414 __le32 *i_data;
415 struct ext4_inode_info *ei;
416 struct inode *tmp_inode = NULL;
417 struct migrate_struct lb;
418 unsigned long max_entries;
419 __u32 goal, tmp_csum_seed;
420 uid_t owner[2];
421 int alloc_ctx;
422
423 /*
424 * If the filesystem does not support extents, or the inode
425 * already is extent-based, error out.
426 */
427 if (!ext4_has_feature_extents(inode->i_sb) ||
428 ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) ||
429 ext4_has_inline_data(inode))
430 return -EINVAL;
431
432 if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0)
433 /*
434 * don't migrate fast symlink
435 */
436 return retval;
437
438 alloc_ctx = ext4_writepages_down_write(inode->i_sb);
439
440 /*
441 * Worst case we can touch the allocation bitmaps and a block
442 * group descriptor block. We do need to worry about
443 * credits for modifying the quota inode.
444 */
445 handle = ext4_journal_start(inode, EXT4_HT_MIGRATE,
446 3 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb));
447
448 if (IS_ERR(handle)) {
449 retval = PTR_ERR(handle);
450 goto out_unlock;
451 }
452 goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) *
453 EXT4_INODES_PER_GROUP(inode->i_sb)) + 1;
454 owner[0] = i_uid_read(inode);
455 owner[1] = i_gid_read(inode);
456 tmp_inode = ext4_new_inode(handle, d_inode(inode->i_sb->s_root),
457 S_IFREG, NULL, goal, owner, 0);
458 if (IS_ERR(tmp_inode)) {
459 retval = PTR_ERR(tmp_inode);
460 ext4_journal_stop(handle);
461 goto out_unlock;
462 }
463 /*
464 * Use the correct seed for checksum (i.e. the seed from 'inode'). This
465 * is so that the metadata blocks will have the correct checksum after
466 * the migration.
467 */
468 ei = EXT4_I(inode);
469 tmp_csum_seed = EXT4_I(tmp_inode)->i_csum_seed;
470 EXT4_I(tmp_inode)->i_csum_seed = ei->i_csum_seed;
471 i_size_write(tmp_inode, i_size_read(inode));
472 /*
473 * Set the i_nlink to zero so it will be deleted later
474 * when we drop inode reference.
475 */
476 clear_nlink(tmp_inode);
477
478 ext4_ext_tree_init(handle, tmp_inode);
479 ext4_journal_stop(handle);
480
481 /*
482 * start with one credit accounted for
483 * superblock modification.
484 *
485 * For the tmp_inode we already have committed the
486 * transaction that created the inode. Later as and
487 * when we add extents we extent the journal
488 */
489 /*
490 * Even though we take i_rwsem we can still cause block
491 * allocation via mmap write to holes. If we have allocated
492 * new blocks we fail migrate. New block allocation will
493 * clear EXT4_STATE_EXT_MIGRATE flag. The flag is updated
494 * with i_data_sem held to prevent racing with block
495 * allocation.
496 */
497 down_read(&EXT4_I(inode)->i_data_sem);
498 ext4_set_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
499 up_read((&EXT4_I(inode)->i_data_sem));
500
501 handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, 1);
502 if (IS_ERR(handle)) {
503 retval = PTR_ERR(handle);
504 goto out_tmp_inode;
505 }
506
507 i_data = ei->i_data;
508 memset(&lb, 0, sizeof(lb));
509
510 /* 32 bit block address 4 bytes */
511 max_entries = inode->i_sb->s_blocksize >> 2;
512 for (i = 0; i < EXT4_NDIR_BLOCKS; i++) {
513 if (i_data[i]) {
514 retval = update_extent_range(handle, tmp_inode,
515 le32_to_cpu(i_data[i]), &lb);
516 if (retval)
517 goto err_out;
518 } else
519 lb.curr_block++;
520 }
521 if (i_data[EXT4_IND_BLOCK]) {
522 retval = update_ind_extent_range(handle, tmp_inode,
523 le32_to_cpu(i_data[EXT4_IND_BLOCK]), &lb);
524 if (retval)
525 goto err_out;
526 } else
527 lb.curr_block += max_entries;
528 if (i_data[EXT4_DIND_BLOCK]) {
529 retval = update_dind_extent_range(handle, tmp_inode,
530 le32_to_cpu(i_data[EXT4_DIND_BLOCK]), &lb);
531 if (retval)
532 goto err_out;
533 } else
534 lb.curr_block += max_entries * max_entries;
535 if (i_data[EXT4_TIND_BLOCK]) {
536 retval = update_tind_extent_range(handle, tmp_inode,
537 le32_to_cpu(i_data[EXT4_TIND_BLOCK]), &lb);
538 if (retval)
539 goto err_out;
540 }
541 /*
542 * Build the last extent
543 */
544 retval = finish_range(handle, tmp_inode, &lb);
545err_out:
546 if (retval)
547 /*
548 * Failure case delete the extent information with the
549 * tmp_inode
550 */
551 free_ext_block(handle, tmp_inode);
552 else {
553 retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode);
554 if (retval)
555 /*
556 * if we fail to swap inode data free the extent
557 * details of the tmp inode
558 */
559 free_ext_block(handle, tmp_inode);
560 }
561
562 /* We mark the tmp_inode dirty via ext4_ext_tree_init. */
563 retval = ext4_journal_ensure_credits(handle, 1, 0);
564 if (retval < 0)
565 goto out_stop;
566 /*
567 * Mark the tmp_inode as of size zero
568 */
569 i_size_write(tmp_inode, 0);
570
571 /*
572 * set the i_blocks count to zero
573 * so that the ext4_evict_inode() does the
574 * right job
575 *
576 * We don't need to take the i_lock because
577 * the inode is not visible to user space.
578 */
579 tmp_inode->i_blocks = 0;
580 EXT4_I(tmp_inode)->i_csum_seed = tmp_csum_seed;
581
582 /* Reset the extent details */
583 ext4_ext_tree_init(handle, tmp_inode);
584out_stop:
585 ext4_journal_stop(handle);
586out_tmp_inode:
587 unlock_new_inode(tmp_inode);
588 iput(tmp_inode);
589out_unlock:
590 ext4_writepages_up_write(inode->i_sb, alloc_ctx);
591 return retval;
592}
593
594/*
595 * Migrate a simple extent-based inode to use the i_blocks[] array
596 */
597int ext4_ind_migrate(struct inode *inode)
598{
599 struct ext4_extent_header *eh;
600 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
601 struct ext4_super_block *es = sbi->s_es;
602 struct ext4_inode_info *ei = EXT4_I(inode);
603 struct ext4_extent *ex;
604 unsigned int i, len;
605 ext4_lblk_t start, end;
606 ext4_fsblk_t blk;
607 handle_t *handle;
608 int ret, ret2 = 0;
609 int alloc_ctx;
610
611 if (!ext4_has_feature_extents(inode->i_sb) ||
612 (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
613 return -EINVAL;
614
615 if (ext4_has_feature_bigalloc(inode->i_sb))
616 return -EOPNOTSUPP;
617
618 /*
619 * In order to get correct extent info, force all delayed allocation
620 * blocks to be allocated, otherwise delayed allocation blocks may not
621 * be reflected and bypass the checks on extent header.
622 */
623 if (test_opt(inode->i_sb, DELALLOC))
624 ext4_alloc_da_blocks(inode);
625
626 alloc_ctx = ext4_writepages_down_write(inode->i_sb);
627
628 handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, 1);
629 if (IS_ERR(handle)) {
630 ret = PTR_ERR(handle);
631 goto out_unlock;
632 }
633
634 down_write(&EXT4_I(inode)->i_data_sem);
635 ret = ext4_ext_check_inode(inode);
636 if (ret)
637 goto errout;
638
639 eh = ext_inode_hdr(inode);
640 ex = EXT_FIRST_EXTENT(eh);
641 if (ext4_blocks_count(es) > EXT4_MAX_BLOCK_FILE_PHYS ||
642 eh->eh_depth != 0 || le16_to_cpu(eh->eh_entries) > 1) {
643 ret = -EOPNOTSUPP;
644 goto errout;
645 }
646 if (eh->eh_entries == 0)
647 blk = len = start = end = 0;
648 else {
649 len = le16_to_cpu(ex->ee_len);
650 blk = ext4_ext_pblock(ex);
651 start = le32_to_cpu(ex->ee_block);
652 end = start + len - 1;
653 if (end >= EXT4_NDIR_BLOCKS) {
654 ret = -EOPNOTSUPP;
655 goto errout;
656 }
657 }
658
659 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
660 memset(ei->i_data, 0, sizeof(ei->i_data));
661 for (i = start; i <= end; i++)
662 ei->i_data[i] = cpu_to_le32(blk++);
663 ret2 = ext4_mark_inode_dirty(handle, inode);
664 if (unlikely(ret2 && !ret))
665 ret = ret2;
666errout:
667 up_write(&EXT4_I(inode)->i_data_sem);
668 ext4_journal_stop(handle);
669out_unlock:
670 ext4_writepages_up_write(inode->i_sb, alloc_ctx);
671 return ret;
672}
1/*
2 * Copyright IBM Corporation, 2007
3 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of version 2.1 of the GNU Lesser General Public License
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12 *
13 */
14
15#include <linux/slab.h>
16#include "ext4_jbd2.h"
17#include "ext4_extents.h"
18
19/*
20 * The contiguous blocks details which can be
21 * represented by a single extent
22 */
23struct migrate_struct {
24 ext4_lblk_t first_block, last_block, curr_block;
25 ext4_fsblk_t first_pblock, last_pblock;
26};
27
28static int finish_range(handle_t *handle, struct inode *inode,
29 struct migrate_struct *lb)
30
31{
32 int retval = 0, needed;
33 struct ext4_extent newext;
34 struct ext4_ext_path *path;
35 if (lb->first_pblock == 0)
36 return 0;
37
38 /* Add the extent to temp inode*/
39 newext.ee_block = cpu_to_le32(lb->first_block);
40 newext.ee_len = cpu_to_le16(lb->last_block - lb->first_block + 1);
41 ext4_ext_store_pblock(&newext, lb->first_pblock);
42 path = ext4_ext_find_extent(inode, lb->first_block, NULL, 0);
43
44 if (IS_ERR(path)) {
45 retval = PTR_ERR(path);
46 path = NULL;
47 goto err_out;
48 }
49
50 /*
51 * Calculate the credit needed to inserting this extent
52 * Since we are doing this in loop we may accumalate extra
53 * credit. But below we try to not accumalate too much
54 * of them by restarting the journal.
55 */
56 needed = ext4_ext_calc_credits_for_single_extent(inode,
57 lb->last_block - lb->first_block + 1, path);
58
59 /*
60 * Make sure the credit we accumalated is not really high
61 */
62 if (needed && ext4_handle_has_enough_credits(handle,
63 EXT4_RESERVE_TRANS_BLOCKS)) {
64 retval = ext4_journal_restart(handle, needed);
65 if (retval)
66 goto err_out;
67 } else if (needed) {
68 retval = ext4_journal_extend(handle, needed);
69 if (retval) {
70 /*
71 * IF not able to extend the journal restart the journal
72 */
73 retval = ext4_journal_restart(handle, needed);
74 if (retval)
75 goto err_out;
76 }
77 }
78 retval = ext4_ext_insert_extent(handle, inode, path, &newext, 0);
79err_out:
80 if (path) {
81 ext4_ext_drop_refs(path);
82 kfree(path);
83 }
84 lb->first_pblock = 0;
85 return retval;
86}
87
88static int update_extent_range(handle_t *handle, struct inode *inode,
89 ext4_fsblk_t pblock, struct migrate_struct *lb)
90{
91 int retval;
92 /*
93 * See if we can add on to the existing range (if it exists)
94 */
95 if (lb->first_pblock &&
96 (lb->last_pblock+1 == pblock) &&
97 (lb->last_block+1 == lb->curr_block)) {
98 lb->last_pblock = pblock;
99 lb->last_block = lb->curr_block;
100 lb->curr_block++;
101 return 0;
102 }
103 /*
104 * Start a new range.
105 */
106 retval = finish_range(handle, inode, lb);
107 lb->first_pblock = lb->last_pblock = pblock;
108 lb->first_block = lb->last_block = lb->curr_block;
109 lb->curr_block++;
110 return retval;
111}
112
113static int update_ind_extent_range(handle_t *handle, struct inode *inode,
114 ext4_fsblk_t pblock,
115 struct migrate_struct *lb)
116{
117 struct buffer_head *bh;
118 __le32 *i_data;
119 int i, retval = 0;
120 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
121
122 bh = sb_bread(inode->i_sb, pblock);
123 if (!bh)
124 return -EIO;
125
126 i_data = (__le32 *)bh->b_data;
127 for (i = 0; i < max_entries; i++) {
128 if (i_data[i]) {
129 retval = update_extent_range(handle, inode,
130 le32_to_cpu(i_data[i]), lb);
131 if (retval)
132 break;
133 } else {
134 lb->curr_block++;
135 }
136 }
137 put_bh(bh);
138 return retval;
139
140}
141
142static int update_dind_extent_range(handle_t *handle, struct inode *inode,
143 ext4_fsblk_t pblock,
144 struct migrate_struct *lb)
145{
146 struct buffer_head *bh;
147 __le32 *i_data;
148 int i, retval = 0;
149 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
150
151 bh = sb_bread(inode->i_sb, pblock);
152 if (!bh)
153 return -EIO;
154
155 i_data = (__le32 *)bh->b_data;
156 for (i = 0; i < max_entries; i++) {
157 if (i_data[i]) {
158 retval = update_ind_extent_range(handle, inode,
159 le32_to_cpu(i_data[i]), lb);
160 if (retval)
161 break;
162 } else {
163 /* Only update the file block number */
164 lb->curr_block += max_entries;
165 }
166 }
167 put_bh(bh);
168 return retval;
169
170}
171
172static int update_tind_extent_range(handle_t *handle, struct inode *inode,
173 ext4_fsblk_t pblock,
174 struct migrate_struct *lb)
175{
176 struct buffer_head *bh;
177 __le32 *i_data;
178 int i, retval = 0;
179 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
180
181 bh = sb_bread(inode->i_sb, pblock);
182 if (!bh)
183 return -EIO;
184
185 i_data = (__le32 *)bh->b_data;
186 for (i = 0; i < max_entries; i++) {
187 if (i_data[i]) {
188 retval = update_dind_extent_range(handle, inode,
189 le32_to_cpu(i_data[i]), lb);
190 if (retval)
191 break;
192 } else {
193 /* Only update the file block number */
194 lb->curr_block += max_entries * max_entries;
195 }
196 }
197 put_bh(bh);
198 return retval;
199
200}
201
202static int extend_credit_for_blkdel(handle_t *handle, struct inode *inode)
203{
204 int retval = 0, needed;
205
206 if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
207 return 0;
208 /*
209 * We are freeing a blocks. During this we touch
210 * superblock, group descriptor and block bitmap.
211 * So allocate a credit of 3. We may update
212 * quota (user and group).
213 */
214 needed = 3 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
215
216 if (ext4_journal_extend(handle, needed) != 0)
217 retval = ext4_journal_restart(handle, needed);
218
219 return retval;
220}
221
222static int free_dind_blocks(handle_t *handle,
223 struct inode *inode, __le32 i_data)
224{
225 int i;
226 __le32 *tmp_idata;
227 struct buffer_head *bh;
228 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
229
230 bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
231 if (!bh)
232 return -EIO;
233
234 tmp_idata = (__le32 *)bh->b_data;
235 for (i = 0; i < max_entries; i++) {
236 if (tmp_idata[i]) {
237 extend_credit_for_blkdel(handle, inode);
238 ext4_free_blocks(handle, inode, NULL,
239 le32_to_cpu(tmp_idata[i]), 1,
240 EXT4_FREE_BLOCKS_METADATA |
241 EXT4_FREE_BLOCKS_FORGET);
242 }
243 }
244 put_bh(bh);
245 extend_credit_for_blkdel(handle, inode);
246 ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1,
247 EXT4_FREE_BLOCKS_METADATA |
248 EXT4_FREE_BLOCKS_FORGET);
249 return 0;
250}
251
252static int free_tind_blocks(handle_t *handle,
253 struct inode *inode, __le32 i_data)
254{
255 int i, retval = 0;
256 __le32 *tmp_idata;
257 struct buffer_head *bh;
258 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
259
260 bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
261 if (!bh)
262 return -EIO;
263
264 tmp_idata = (__le32 *)bh->b_data;
265 for (i = 0; i < max_entries; i++) {
266 if (tmp_idata[i]) {
267 retval = free_dind_blocks(handle,
268 inode, tmp_idata[i]);
269 if (retval) {
270 put_bh(bh);
271 return retval;
272 }
273 }
274 }
275 put_bh(bh);
276 extend_credit_for_blkdel(handle, inode);
277 ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1,
278 EXT4_FREE_BLOCKS_METADATA |
279 EXT4_FREE_BLOCKS_FORGET);
280 return 0;
281}
282
283static int free_ind_block(handle_t *handle, struct inode *inode, __le32 *i_data)
284{
285 int retval;
286
287 /* ei->i_data[EXT4_IND_BLOCK] */
288 if (i_data[0]) {
289 extend_credit_for_blkdel(handle, inode);
290 ext4_free_blocks(handle, inode, NULL,
291 le32_to_cpu(i_data[0]), 1,
292 EXT4_FREE_BLOCKS_METADATA |
293 EXT4_FREE_BLOCKS_FORGET);
294 }
295
296 /* ei->i_data[EXT4_DIND_BLOCK] */
297 if (i_data[1]) {
298 retval = free_dind_blocks(handle, inode, i_data[1]);
299 if (retval)
300 return retval;
301 }
302
303 /* ei->i_data[EXT4_TIND_BLOCK] */
304 if (i_data[2]) {
305 retval = free_tind_blocks(handle, inode, i_data[2]);
306 if (retval)
307 return retval;
308 }
309 return 0;
310}
311
312static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
313 struct inode *tmp_inode)
314{
315 int retval;
316 __le32 i_data[3];
317 struct ext4_inode_info *ei = EXT4_I(inode);
318 struct ext4_inode_info *tmp_ei = EXT4_I(tmp_inode);
319
320 /*
321 * One credit accounted for writing the
322 * i_data field of the original inode
323 */
324 retval = ext4_journal_extend(handle, 1);
325 if (retval) {
326 retval = ext4_journal_restart(handle, 1);
327 if (retval)
328 goto err_out;
329 }
330
331 i_data[0] = ei->i_data[EXT4_IND_BLOCK];
332 i_data[1] = ei->i_data[EXT4_DIND_BLOCK];
333 i_data[2] = ei->i_data[EXT4_TIND_BLOCK];
334
335 down_write(&EXT4_I(inode)->i_data_sem);
336 /*
337 * if EXT4_STATE_EXT_MIGRATE is cleared a block allocation
338 * happened after we started the migrate. We need to
339 * fail the migrate
340 */
341 if (!ext4_test_inode_state(inode, EXT4_STATE_EXT_MIGRATE)) {
342 retval = -EAGAIN;
343 up_write(&EXT4_I(inode)->i_data_sem);
344 goto err_out;
345 } else
346 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
347 /*
348 * We have the extent map build with the tmp inode.
349 * Now copy the i_data across
350 */
351 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
352 memcpy(ei->i_data, tmp_ei->i_data, sizeof(ei->i_data));
353
354 /*
355 * Update i_blocks with the new blocks that got
356 * allocated while adding extents for extent index
357 * blocks.
358 *
359 * While converting to extents we need not
360 * update the orignal inode i_blocks for extent blocks
361 * via quota APIs. The quota update happened via tmp_inode already.
362 */
363 spin_lock(&inode->i_lock);
364 inode->i_blocks += tmp_inode->i_blocks;
365 spin_unlock(&inode->i_lock);
366 up_write(&EXT4_I(inode)->i_data_sem);
367
368 /*
369 * We mark the inode dirty after, because we decrement the
370 * i_blocks when freeing the indirect meta-data blocks
371 */
372 retval = free_ind_block(handle, inode, i_data);
373 ext4_mark_inode_dirty(handle, inode);
374
375err_out:
376 return retval;
377}
378
379static int free_ext_idx(handle_t *handle, struct inode *inode,
380 struct ext4_extent_idx *ix)
381{
382 int i, retval = 0;
383 ext4_fsblk_t block;
384 struct buffer_head *bh;
385 struct ext4_extent_header *eh;
386
387 block = ext4_idx_pblock(ix);
388 bh = sb_bread(inode->i_sb, block);
389 if (!bh)
390 return -EIO;
391
392 eh = (struct ext4_extent_header *)bh->b_data;
393 if (eh->eh_depth != 0) {
394 ix = EXT_FIRST_INDEX(eh);
395 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
396 retval = free_ext_idx(handle, inode, ix);
397 if (retval)
398 break;
399 }
400 }
401 put_bh(bh);
402 extend_credit_for_blkdel(handle, inode);
403 ext4_free_blocks(handle, inode, NULL, block, 1,
404 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
405 return retval;
406}
407
408/*
409 * Free the extent meta data blocks only
410 */
411static int free_ext_block(handle_t *handle, struct inode *inode)
412{
413 int i, retval = 0;
414 struct ext4_inode_info *ei = EXT4_I(inode);
415 struct ext4_extent_header *eh = (struct ext4_extent_header *)ei->i_data;
416 struct ext4_extent_idx *ix;
417 if (eh->eh_depth == 0)
418 /*
419 * No extra blocks allocated for extent meta data
420 */
421 return 0;
422 ix = EXT_FIRST_INDEX(eh);
423 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
424 retval = free_ext_idx(handle, inode, ix);
425 if (retval)
426 return retval;
427 }
428 return retval;
429}
430
431int ext4_ext_migrate(struct inode *inode)
432{
433 handle_t *handle;
434 int retval = 0, i;
435 __le32 *i_data;
436 struct ext4_inode_info *ei;
437 struct inode *tmp_inode = NULL;
438 struct migrate_struct lb;
439 unsigned long max_entries;
440 __u32 goal;
441 uid_t owner[2];
442
443 /*
444 * If the filesystem does not support extents, or the inode
445 * already is extent-based, error out.
446 */
447 if (!EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb,
448 EXT4_FEATURE_INCOMPAT_EXTENTS) ||
449 (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
450 return -EINVAL;
451
452 if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0)
453 /*
454 * don't migrate fast symlink
455 */
456 return retval;
457
458 /*
459 * Worst case we can touch the allocation bitmaps, a bgd
460 * block, and a block to link in the orphan list. We do need
461 * need to worry about credits for modifying the quota inode.
462 */
463 handle = ext4_journal_start(inode, EXT4_HT_MIGRATE,
464 4 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb));
465
466 if (IS_ERR(handle)) {
467 retval = PTR_ERR(handle);
468 return retval;
469 }
470 goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) *
471 EXT4_INODES_PER_GROUP(inode->i_sb)) + 1;
472 owner[0] = i_uid_read(inode);
473 owner[1] = i_gid_read(inode);
474 tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
475 S_IFREG, NULL, goal, owner);
476 if (IS_ERR(tmp_inode)) {
477 retval = PTR_ERR(tmp_inode);
478 ext4_journal_stop(handle);
479 return retval;
480 }
481 i_size_write(tmp_inode, i_size_read(inode));
482 /*
483 * Set the i_nlink to zero so it will be deleted later
484 * when we drop inode reference.
485 */
486 clear_nlink(tmp_inode);
487
488 ext4_ext_tree_init(handle, tmp_inode);
489 ext4_orphan_add(handle, tmp_inode);
490 ext4_journal_stop(handle);
491
492 /*
493 * start with one credit accounted for
494 * superblock modification.
495 *
496 * For the tmp_inode we already have committed the
497 * transaction that created the inode. Later as and
498 * when we add extents we extent the journal
499 */
500 /*
501 * Even though we take i_mutex we can still cause block
502 * allocation via mmap write to holes. If we have allocated
503 * new blocks we fail migrate. New block allocation will
504 * clear EXT4_STATE_EXT_MIGRATE flag. The flag is updated
505 * with i_data_sem held to prevent racing with block
506 * allocation.
507 */
508 down_read((&EXT4_I(inode)->i_data_sem));
509 ext4_set_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
510 up_read((&EXT4_I(inode)->i_data_sem));
511
512 handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, 1);
513 if (IS_ERR(handle)) {
514 /*
515 * It is impossible to update on-disk structures without
516 * a handle, so just rollback in-core changes and live other
517 * work to orphan_list_cleanup()
518 */
519 ext4_orphan_del(NULL, tmp_inode);
520 retval = PTR_ERR(handle);
521 goto out;
522 }
523
524 ei = EXT4_I(inode);
525 i_data = ei->i_data;
526 memset(&lb, 0, sizeof(lb));
527
528 /* 32 bit block address 4 bytes */
529 max_entries = inode->i_sb->s_blocksize >> 2;
530 for (i = 0; i < EXT4_NDIR_BLOCKS; i++) {
531 if (i_data[i]) {
532 retval = update_extent_range(handle, tmp_inode,
533 le32_to_cpu(i_data[i]), &lb);
534 if (retval)
535 goto err_out;
536 } else
537 lb.curr_block++;
538 }
539 if (i_data[EXT4_IND_BLOCK]) {
540 retval = update_ind_extent_range(handle, tmp_inode,
541 le32_to_cpu(i_data[EXT4_IND_BLOCK]), &lb);
542 if (retval)
543 goto err_out;
544 } else
545 lb.curr_block += max_entries;
546 if (i_data[EXT4_DIND_BLOCK]) {
547 retval = update_dind_extent_range(handle, tmp_inode,
548 le32_to_cpu(i_data[EXT4_DIND_BLOCK]), &lb);
549 if (retval)
550 goto err_out;
551 } else
552 lb.curr_block += max_entries * max_entries;
553 if (i_data[EXT4_TIND_BLOCK]) {
554 retval = update_tind_extent_range(handle, tmp_inode,
555 le32_to_cpu(i_data[EXT4_TIND_BLOCK]), &lb);
556 if (retval)
557 goto err_out;
558 }
559 /*
560 * Build the last extent
561 */
562 retval = finish_range(handle, tmp_inode, &lb);
563err_out:
564 if (retval)
565 /*
566 * Failure case delete the extent information with the
567 * tmp_inode
568 */
569 free_ext_block(handle, tmp_inode);
570 else {
571 retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode);
572 if (retval)
573 /*
574 * if we fail to swap inode data free the extent
575 * details of the tmp inode
576 */
577 free_ext_block(handle, tmp_inode);
578 }
579
580 /* We mark the tmp_inode dirty via ext4_ext_tree_init. */
581 if (ext4_journal_extend(handle, 1) != 0)
582 ext4_journal_restart(handle, 1);
583
584 /*
585 * Mark the tmp_inode as of size zero
586 */
587 i_size_write(tmp_inode, 0);
588
589 /*
590 * set the i_blocks count to zero
591 * so that the ext4_delete_inode does the
592 * right job
593 *
594 * We don't need to take the i_lock because
595 * the inode is not visible to user space.
596 */
597 tmp_inode->i_blocks = 0;
598
599 /* Reset the extent details */
600 ext4_ext_tree_init(handle, tmp_inode);
601 ext4_journal_stop(handle);
602out:
603 unlock_new_inode(tmp_inode);
604 iput(tmp_inode);
605
606 return retval;
607}
608
609/*
610 * Migrate a simple extent-based inode to use the i_blocks[] array
611 */
612int ext4_ind_migrate(struct inode *inode)
613{
614 struct ext4_extent_header *eh;
615 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
616 struct ext4_inode_info *ei = EXT4_I(inode);
617 struct ext4_extent *ex;
618 unsigned int i, len;
619 ext4_fsblk_t blk;
620 handle_t *handle;
621 int ret;
622
623 if (!EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb,
624 EXT4_FEATURE_INCOMPAT_EXTENTS) ||
625 (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
626 return -EINVAL;
627
628 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
629 EXT4_FEATURE_RO_COMPAT_BIGALLOC))
630 return -EOPNOTSUPP;
631
632 handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, 1);
633 if (IS_ERR(handle))
634 return PTR_ERR(handle);
635
636 down_write(&EXT4_I(inode)->i_data_sem);
637 ret = ext4_ext_check_inode(inode);
638 if (ret)
639 goto errout;
640
641 eh = ext_inode_hdr(inode);
642 ex = EXT_FIRST_EXTENT(eh);
643 if (ext4_blocks_count(es) > EXT4_MAX_BLOCK_FILE_PHYS ||
644 eh->eh_depth != 0 || le16_to_cpu(eh->eh_entries) > 1) {
645 ret = -EOPNOTSUPP;
646 goto errout;
647 }
648 if (eh->eh_entries == 0)
649 blk = len = 0;
650 else {
651 len = le16_to_cpu(ex->ee_len);
652 blk = ext4_ext_pblock(ex);
653 if (len > EXT4_NDIR_BLOCKS) {
654 ret = -EOPNOTSUPP;
655 goto errout;
656 }
657 }
658
659 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
660 memset(ei->i_data, 0, sizeof(ei->i_data));
661 for (i=0; i < len; i++)
662 ei->i_data[i] = cpu_to_le32(blk++);
663 ext4_mark_inode_dirty(handle, inode);
664errout:
665 ext4_journal_stop(handle);
666 up_write(&EXT4_I(inode)->i_data_sem);
667 return ret;
668}