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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 /* Locking only for convinience since we are operating on temp inode */
43 down_write(&EXT4_I(inode)->i_data_sem);
44 path = ext4_find_extent(inode, lb->first_block, NULL, 0);
45 if (IS_ERR(path)) {
46 retval = PTR_ERR(path);
47 path = NULL;
48 goto err_out;
49 }
50
51 /*
52 * Calculate the credit needed to inserting this extent
53 * Since we are doing this in loop we may accumalate extra
54 * credit. But below we try to not accumalate too much
55 * of them by restarting the journal.
56 */
57 needed = ext4_ext_calc_credits_for_single_extent(inode,
58 lb->last_block - lb->first_block + 1, path);
59
60 /*
61 * Make sure the credit we accumalated is not really high
62 */
63 if (needed && ext4_handle_has_enough_credits(handle,
64 EXT4_RESERVE_TRANS_BLOCKS)) {
65 up_write((&EXT4_I(inode)->i_data_sem));
66 retval = ext4_journal_restart(handle, needed);
67 down_write((&EXT4_I(inode)->i_data_sem));
68 if (retval)
69 goto err_out;
70 } else if (needed) {
71 retval = ext4_journal_extend(handle, needed);
72 if (retval) {
73 /*
74 * IF not able to extend the journal restart the journal
75 */
76 up_write((&EXT4_I(inode)->i_data_sem));
77 retval = ext4_journal_restart(handle, needed);
78 down_write((&EXT4_I(inode)->i_data_sem));
79 if (retval)
80 goto err_out;
81 }
82 }
83 retval = ext4_ext_insert_extent(handle, inode, &path, &newext, 0);
84err_out:
85 up_write((&EXT4_I(inode)->i_data_sem));
86 ext4_ext_drop_refs(path);
87 kfree(path);
88 lb->first_pblock = 0;
89 return retval;
90}
91
92static int update_extent_range(handle_t *handle, struct inode *inode,
93 ext4_fsblk_t pblock, struct migrate_struct *lb)
94{
95 int retval;
96 /*
97 * See if we can add on to the existing range (if it exists)
98 */
99 if (lb->first_pblock &&
100 (lb->last_pblock+1 == pblock) &&
101 (lb->last_block+1 == lb->curr_block)) {
102 lb->last_pblock = pblock;
103 lb->last_block = lb->curr_block;
104 lb->curr_block++;
105 return 0;
106 }
107 /*
108 * Start a new range.
109 */
110 retval = finish_range(handle, inode, lb);
111 lb->first_pblock = lb->last_pblock = pblock;
112 lb->first_block = lb->last_block = lb->curr_block;
113 lb->curr_block++;
114 return retval;
115}
116
117static int update_ind_extent_range(handle_t *handle, struct inode *inode,
118 ext4_fsblk_t pblock,
119 struct migrate_struct *lb)
120{
121 struct buffer_head *bh;
122 __le32 *i_data;
123 int i, retval = 0;
124 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
125
126 bh = sb_bread(inode->i_sb, pblock);
127 if (!bh)
128 return -EIO;
129
130 i_data = (__le32 *)bh->b_data;
131 for (i = 0; i < max_entries; i++) {
132 if (i_data[i]) {
133 retval = update_extent_range(handle, inode,
134 le32_to_cpu(i_data[i]), lb);
135 if (retval)
136 break;
137 } else {
138 lb->curr_block++;
139 }
140 }
141 put_bh(bh);
142 return retval;
143
144}
145
146static int update_dind_extent_range(handle_t *handle, struct inode *inode,
147 ext4_fsblk_t pblock,
148 struct migrate_struct *lb)
149{
150 struct buffer_head *bh;
151 __le32 *i_data;
152 int i, retval = 0;
153 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
154
155 bh = sb_bread(inode->i_sb, pblock);
156 if (!bh)
157 return -EIO;
158
159 i_data = (__le32 *)bh->b_data;
160 for (i = 0; i < max_entries; i++) {
161 if (i_data[i]) {
162 retval = update_ind_extent_range(handle, inode,
163 le32_to_cpu(i_data[i]), lb);
164 if (retval)
165 break;
166 } else {
167 /* Only update the file block number */
168 lb->curr_block += max_entries;
169 }
170 }
171 put_bh(bh);
172 return retval;
173
174}
175
176static int update_tind_extent_range(handle_t *handle, struct inode *inode,
177 ext4_fsblk_t pblock,
178 struct migrate_struct *lb)
179{
180 struct buffer_head *bh;
181 __le32 *i_data;
182 int i, retval = 0;
183 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
184
185 bh = sb_bread(inode->i_sb, pblock);
186 if (!bh)
187 return -EIO;
188
189 i_data = (__le32 *)bh->b_data;
190 for (i = 0; i < max_entries; i++) {
191 if (i_data[i]) {
192 retval = update_dind_extent_range(handle, inode,
193 le32_to_cpu(i_data[i]), lb);
194 if (retval)
195 break;
196 } else {
197 /* Only update the file block number */
198 lb->curr_block += max_entries * max_entries;
199 }
200 }
201 put_bh(bh);
202 return retval;
203
204}
205
206static int extend_credit_for_blkdel(handle_t *handle, struct inode *inode)
207{
208 int retval = 0, needed;
209
210 if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
211 return 0;
212 /*
213 * We are freeing a blocks. During this we touch
214 * superblock, group descriptor and block bitmap.
215 * So allocate a credit of 3. We may update
216 * quota (user and group).
217 */
218 needed = 3 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
219
220 if (ext4_journal_extend(handle, needed) != 0)
221 retval = ext4_journal_restart(handle, needed);
222
223 return retval;
224}
225
226static int free_dind_blocks(handle_t *handle,
227 struct inode *inode, __le32 i_data)
228{
229 int i;
230 __le32 *tmp_idata;
231 struct buffer_head *bh;
232 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
233
234 bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
235 if (!bh)
236 return -EIO;
237
238 tmp_idata = (__le32 *)bh->b_data;
239 for (i = 0; i < max_entries; i++) {
240 if (tmp_idata[i]) {
241 extend_credit_for_blkdel(handle, inode);
242 ext4_free_blocks(handle, inode, NULL,
243 le32_to_cpu(tmp_idata[i]), 1,
244 EXT4_FREE_BLOCKS_METADATA |
245 EXT4_FREE_BLOCKS_FORGET);
246 }
247 }
248 put_bh(bh);
249 extend_credit_for_blkdel(handle, inode);
250 ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1,
251 EXT4_FREE_BLOCKS_METADATA |
252 EXT4_FREE_BLOCKS_FORGET);
253 return 0;
254}
255
256static int free_tind_blocks(handle_t *handle,
257 struct inode *inode, __le32 i_data)
258{
259 int i, retval = 0;
260 __le32 *tmp_idata;
261 struct buffer_head *bh;
262 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
263
264 bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
265 if (!bh)
266 return -EIO;
267
268 tmp_idata = (__le32 *)bh->b_data;
269 for (i = 0; i < max_entries; i++) {
270 if (tmp_idata[i]) {
271 retval = free_dind_blocks(handle,
272 inode, tmp_idata[i]);
273 if (retval) {
274 put_bh(bh);
275 return retval;
276 }
277 }
278 }
279 put_bh(bh);
280 extend_credit_for_blkdel(handle, inode);
281 ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1,
282 EXT4_FREE_BLOCKS_METADATA |
283 EXT4_FREE_BLOCKS_FORGET);
284 return 0;
285}
286
287static int free_ind_block(handle_t *handle, struct inode *inode, __le32 *i_data)
288{
289 int retval;
290
291 /* ei->i_data[EXT4_IND_BLOCK] */
292 if (i_data[0]) {
293 extend_credit_for_blkdel(handle, inode);
294 ext4_free_blocks(handle, inode, NULL,
295 le32_to_cpu(i_data[0]), 1,
296 EXT4_FREE_BLOCKS_METADATA |
297 EXT4_FREE_BLOCKS_FORGET);
298 }
299
300 /* ei->i_data[EXT4_DIND_BLOCK] */
301 if (i_data[1]) {
302 retval = free_dind_blocks(handle, inode, i_data[1]);
303 if (retval)
304 return retval;
305 }
306
307 /* ei->i_data[EXT4_TIND_BLOCK] */
308 if (i_data[2]) {
309 retval = free_tind_blocks(handle, inode, i_data[2]);
310 if (retval)
311 return retval;
312 }
313 return 0;
314}
315
316static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
317 struct inode *tmp_inode)
318{
319 int retval;
320 __le32 i_data[3];
321 struct ext4_inode_info *ei = EXT4_I(inode);
322 struct ext4_inode_info *tmp_ei = EXT4_I(tmp_inode);
323
324 /*
325 * One credit accounted for writing the
326 * i_data field of the original inode
327 */
328 retval = ext4_journal_extend(handle, 1);
329 if (retval) {
330 retval = ext4_journal_restart(handle, 1);
331 if (retval)
332 goto err_out;
333 }
334
335 i_data[0] = ei->i_data[EXT4_IND_BLOCK];
336 i_data[1] = ei->i_data[EXT4_DIND_BLOCK];
337 i_data[2] = ei->i_data[EXT4_TIND_BLOCK];
338
339 down_write(&EXT4_I(inode)->i_data_sem);
340 /*
341 * if EXT4_STATE_EXT_MIGRATE is cleared a block allocation
342 * happened after we started the migrate. We need to
343 * fail the migrate
344 */
345 if (!ext4_test_inode_state(inode, EXT4_STATE_EXT_MIGRATE)) {
346 retval = -EAGAIN;
347 up_write(&EXT4_I(inode)->i_data_sem);
348 goto err_out;
349 } else
350 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
351 /*
352 * We have the extent map build with the tmp inode.
353 * Now copy the i_data across
354 */
355 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
356 memcpy(ei->i_data, tmp_ei->i_data, sizeof(ei->i_data));
357
358 /*
359 * Update i_blocks with the new blocks that got
360 * allocated while adding extents for extent index
361 * blocks.
362 *
363 * While converting to extents we need not
364 * update the original inode i_blocks for extent blocks
365 * via quota APIs. The quota update happened via tmp_inode already.
366 */
367 spin_lock(&inode->i_lock);
368 inode->i_blocks += tmp_inode->i_blocks;
369 spin_unlock(&inode->i_lock);
370 up_write(&EXT4_I(inode)->i_data_sem);
371
372 /*
373 * We mark the inode dirty after, because we decrement the
374 * i_blocks when freeing the indirect meta-data blocks
375 */
376 retval = free_ind_block(handle, inode, i_data);
377 ext4_mark_inode_dirty(handle, inode);
378
379err_out:
380 return retval;
381}
382
383static int free_ext_idx(handle_t *handle, struct inode *inode,
384 struct ext4_extent_idx *ix)
385{
386 int i, retval = 0;
387 ext4_fsblk_t block;
388 struct buffer_head *bh;
389 struct ext4_extent_header *eh;
390
391 block = ext4_idx_pblock(ix);
392 bh = sb_bread(inode->i_sb, block);
393 if (!bh)
394 return -EIO;
395
396 eh = (struct ext4_extent_header *)bh->b_data;
397 if (eh->eh_depth != 0) {
398 ix = EXT_FIRST_INDEX(eh);
399 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
400 retval = free_ext_idx(handle, inode, ix);
401 if (retval)
402 break;
403 }
404 }
405 put_bh(bh);
406 extend_credit_for_blkdel(handle, inode);
407 ext4_free_blocks(handle, inode, NULL, block, 1,
408 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
409 return retval;
410}
411
412/*
413 * Free the extent meta data blocks only
414 */
415static int free_ext_block(handle_t *handle, struct inode *inode)
416{
417 int i, retval = 0;
418 struct ext4_inode_info *ei = EXT4_I(inode);
419 struct ext4_extent_header *eh = (struct ext4_extent_header *)ei->i_data;
420 struct ext4_extent_idx *ix;
421 if (eh->eh_depth == 0)
422 /*
423 * No extra blocks allocated for extent meta data
424 */
425 return 0;
426 ix = EXT_FIRST_INDEX(eh);
427 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
428 retval = free_ext_idx(handle, inode, ix);
429 if (retval)
430 return retval;
431 }
432 return retval;
433}
434
435int ext4_ext_migrate(struct inode *inode)
436{
437 handle_t *handle;
438 int retval = 0, i;
439 __le32 *i_data;
440 struct ext4_inode_info *ei;
441 struct inode *tmp_inode = NULL;
442 struct migrate_struct lb;
443 unsigned long max_entries;
444 __u32 goal;
445 uid_t owner[2];
446
447 /*
448 * If the filesystem does not support extents, or the inode
449 * already is extent-based, error out.
450 */
451 if (!ext4_has_feature_extents(inode->i_sb) ||
452 (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
453 return -EINVAL;
454
455 if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0)
456 /*
457 * don't migrate fast symlink
458 */
459 return retval;
460
461 /*
462 * Worst case we can touch the allocation bitmaps, a bgd
463 * block, and a block to link in the orphan list. We do need
464 * need to worry about credits for modifying the quota inode.
465 */
466 handle = ext4_journal_start(inode, EXT4_HT_MIGRATE,
467 4 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb));
468
469 if (IS_ERR(handle)) {
470 retval = PTR_ERR(handle);
471 return retval;
472 }
473 goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) *
474 EXT4_INODES_PER_GROUP(inode->i_sb)) + 1;
475 owner[0] = i_uid_read(inode);
476 owner[1] = i_gid_read(inode);
477 tmp_inode = ext4_new_inode(handle, d_inode(inode->i_sb->s_root),
478 S_IFREG, NULL, goal, owner);
479 if (IS_ERR(tmp_inode)) {
480 retval = PTR_ERR(tmp_inode);
481 ext4_journal_stop(handle);
482 return retval;
483 }
484 i_size_write(tmp_inode, i_size_read(inode));
485 /*
486 * Set the i_nlink to zero so it will be deleted later
487 * when we drop inode reference.
488 */
489 clear_nlink(tmp_inode);
490
491 ext4_ext_tree_init(handle, tmp_inode);
492 ext4_orphan_add(handle, tmp_inode);
493 ext4_journal_stop(handle);
494
495 /*
496 * start with one credit accounted for
497 * superblock modification.
498 *
499 * For the tmp_inode we already have committed the
500 * transaction that created the inode. Later as and
501 * when we add extents we extent the journal
502 */
503 /*
504 * Even though we take i_mutex we can still cause block
505 * allocation via mmap write to holes. If we have allocated
506 * new blocks we fail migrate. New block allocation will
507 * clear EXT4_STATE_EXT_MIGRATE flag. The flag is updated
508 * with i_data_sem held to prevent racing with block
509 * allocation.
510 */
511 down_read(&EXT4_I(inode)->i_data_sem);
512 ext4_set_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
513 up_read((&EXT4_I(inode)->i_data_sem));
514
515 handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, 1);
516 if (IS_ERR(handle)) {
517 /*
518 * It is impossible to update on-disk structures without
519 * a handle, so just rollback in-core changes and live other
520 * work to orphan_list_cleanup()
521 */
522 ext4_orphan_del(NULL, tmp_inode);
523 retval = PTR_ERR(handle);
524 goto out;
525 }
526
527 ei = EXT4_I(inode);
528 i_data = ei->i_data;
529 memset(&lb, 0, sizeof(lb));
530
531 /* 32 bit block address 4 bytes */
532 max_entries = inode->i_sb->s_blocksize >> 2;
533 for (i = 0; i < EXT4_NDIR_BLOCKS; i++) {
534 if (i_data[i]) {
535 retval = update_extent_range(handle, tmp_inode,
536 le32_to_cpu(i_data[i]), &lb);
537 if (retval)
538 goto err_out;
539 } else
540 lb.curr_block++;
541 }
542 if (i_data[EXT4_IND_BLOCK]) {
543 retval = update_ind_extent_range(handle, tmp_inode,
544 le32_to_cpu(i_data[EXT4_IND_BLOCK]), &lb);
545 if (retval)
546 goto err_out;
547 } else
548 lb.curr_block += max_entries;
549 if (i_data[EXT4_DIND_BLOCK]) {
550 retval = update_dind_extent_range(handle, tmp_inode,
551 le32_to_cpu(i_data[EXT4_DIND_BLOCK]), &lb);
552 if (retval)
553 goto err_out;
554 } else
555 lb.curr_block += max_entries * max_entries;
556 if (i_data[EXT4_TIND_BLOCK]) {
557 retval = update_tind_extent_range(handle, tmp_inode,
558 le32_to_cpu(i_data[EXT4_TIND_BLOCK]), &lb);
559 if (retval)
560 goto err_out;
561 }
562 /*
563 * Build the last extent
564 */
565 retval = finish_range(handle, tmp_inode, &lb);
566err_out:
567 if (retval)
568 /*
569 * Failure case delete the extent information with the
570 * tmp_inode
571 */
572 free_ext_block(handle, tmp_inode);
573 else {
574 retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode);
575 if (retval)
576 /*
577 * if we fail to swap inode data free the extent
578 * details of the tmp inode
579 */
580 free_ext_block(handle, tmp_inode);
581 }
582
583 /* We mark the tmp_inode dirty via ext4_ext_tree_init. */
584 if (ext4_journal_extend(handle, 1) != 0)
585 ext4_journal_restart(handle, 1);
586
587 /*
588 * Mark the tmp_inode as of size zero
589 */
590 i_size_write(tmp_inode, 0);
591
592 /*
593 * set the i_blocks count to zero
594 * so that the ext4_evict_inode() does the
595 * right job
596 *
597 * We don't need to take the i_lock because
598 * the inode is not visible to user space.
599 */
600 tmp_inode->i_blocks = 0;
601
602 /* Reset the extent details */
603 ext4_ext_tree_init(handle, tmp_inode);
604 ext4_journal_stop(handle);
605out:
606 unlock_new_inode(tmp_inode);
607 iput(tmp_inode);
608
609 return retval;
610}
611
612/*
613 * Migrate a simple extent-based inode to use the i_blocks[] array
614 */
615int ext4_ind_migrate(struct inode *inode)
616{
617 struct ext4_extent_header *eh;
618 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
619 struct ext4_inode_info *ei = EXT4_I(inode);
620 struct ext4_extent *ex;
621 unsigned int i, len;
622 ext4_lblk_t start, end;
623 ext4_fsblk_t blk;
624 handle_t *handle;
625 int ret;
626
627 if (!ext4_has_feature_extents(inode->i_sb) ||
628 (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
629 return -EINVAL;
630
631 if (ext4_has_feature_bigalloc(inode->i_sb))
632 return -EOPNOTSUPP;
633
634 /*
635 * In order to get correct extent info, force all delayed allocation
636 * blocks to be allocated, otherwise delayed allocation blocks may not
637 * be reflected and bypass the checks on extent header.
638 */
639 if (test_opt(inode->i_sb, DELALLOC))
640 ext4_alloc_da_blocks(inode);
641
642 handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, 1);
643 if (IS_ERR(handle))
644 return PTR_ERR(handle);
645
646 down_write(&EXT4_I(inode)->i_data_sem);
647 ret = ext4_ext_check_inode(inode);
648 if (ret)
649 goto errout;
650
651 eh = ext_inode_hdr(inode);
652 ex = EXT_FIRST_EXTENT(eh);
653 if (ext4_blocks_count(es) > EXT4_MAX_BLOCK_FILE_PHYS ||
654 eh->eh_depth != 0 || le16_to_cpu(eh->eh_entries) > 1) {
655 ret = -EOPNOTSUPP;
656 goto errout;
657 }
658 if (eh->eh_entries == 0)
659 blk = len = start = end = 0;
660 else {
661 len = le16_to_cpu(ex->ee_len);
662 blk = ext4_ext_pblock(ex);
663 start = le32_to_cpu(ex->ee_block);
664 end = start + len - 1;
665 if (end >= EXT4_NDIR_BLOCKS) {
666 ret = -EOPNOTSUPP;
667 goto errout;
668 }
669 }
670
671 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
672 memset(ei->i_data, 0, sizeof(ei->i_data));
673 for (i = start; i <= end; i++)
674 ei->i_data[i] = cpu_to_le32(blk++);
675 ext4_mark_inode_dirty(handle, inode);
676errout:
677 ext4_journal_stop(handle);
678 up_write(&EXT4_I(inode)->i_data_sem);
679 return ret;
680}
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
18/*
19 * The contiguous blocks details which can be
20 * represented by a single extent
21 */
22struct migrate_struct {
23 ext4_lblk_t first_block, last_block, curr_block;
24 ext4_fsblk_t first_pblock, last_pblock;
25};
26
27static int finish_range(handle_t *handle, struct inode *inode,
28 struct migrate_struct *lb)
29
30{
31 int retval = 0, needed;
32 struct ext4_extent newext;
33 struct ext4_ext_path *path;
34 if (lb->first_pblock == 0)
35 return 0;
36
37 /* Add the extent to temp inode*/
38 newext.ee_block = cpu_to_le32(lb->first_block);
39 newext.ee_len = cpu_to_le16(lb->last_block - lb->first_block + 1);
40 ext4_ext_store_pblock(&newext, lb->first_pblock);
41 path = ext4_ext_find_extent(inode, lb->first_block, NULL);
42
43 if (IS_ERR(path)) {
44 retval = PTR_ERR(path);
45 path = NULL;
46 goto err_out;
47 }
48
49 /*
50 * Calculate the credit needed to inserting this extent
51 * Since we are doing this in loop we may accumalate extra
52 * credit. But below we try to not accumalate too much
53 * of them by restarting the journal.
54 */
55 needed = ext4_ext_calc_credits_for_single_extent(inode,
56 lb->last_block - lb->first_block + 1, path);
57
58 /*
59 * Make sure the credit we accumalated is not really high
60 */
61 if (needed && ext4_handle_has_enough_credits(handle,
62 EXT4_RESERVE_TRANS_BLOCKS)) {
63 retval = ext4_journal_restart(handle, needed);
64 if (retval)
65 goto err_out;
66 } else if (needed) {
67 retval = ext4_journal_extend(handle, needed);
68 if (retval) {
69 /*
70 * IF not able to extend the journal restart the journal
71 */
72 retval = ext4_journal_restart(handle, needed);
73 if (retval)
74 goto err_out;
75 }
76 }
77 retval = ext4_ext_insert_extent(handle, inode, path, &newext, 0);
78err_out:
79 if (path) {
80 ext4_ext_drop_refs(path);
81 kfree(path);
82 }
83 lb->first_pblock = 0;
84 return retval;
85}
86
87static int update_extent_range(handle_t *handle, struct inode *inode,
88 ext4_fsblk_t pblock, struct migrate_struct *lb)
89{
90 int retval;
91 /*
92 * See if we can add on to the existing range (if it exists)
93 */
94 if (lb->first_pblock &&
95 (lb->last_pblock+1 == pblock) &&
96 (lb->last_block+1 == lb->curr_block)) {
97 lb->last_pblock = pblock;
98 lb->last_block = lb->curr_block;
99 lb->curr_block++;
100 return 0;
101 }
102 /*
103 * Start a new range.
104 */
105 retval = finish_range(handle, inode, lb);
106 lb->first_pblock = lb->last_pblock = pblock;
107 lb->first_block = lb->last_block = lb->curr_block;
108 lb->curr_block++;
109 return retval;
110}
111
112static int update_ind_extent_range(handle_t *handle, struct inode *inode,
113 ext4_fsblk_t pblock,
114 struct migrate_struct *lb)
115{
116 struct buffer_head *bh;
117 __le32 *i_data;
118 int i, retval = 0;
119 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
120
121 bh = sb_bread(inode->i_sb, pblock);
122 if (!bh)
123 return -EIO;
124
125 i_data = (__le32 *)bh->b_data;
126 for (i = 0; i < max_entries; i++) {
127 if (i_data[i]) {
128 retval = update_extent_range(handle, inode,
129 le32_to_cpu(i_data[i]), lb);
130 if (retval)
131 break;
132 } else {
133 lb->curr_block++;
134 }
135 }
136 put_bh(bh);
137 return retval;
138
139}
140
141static int update_dind_extent_range(handle_t *handle, struct inode *inode,
142 ext4_fsblk_t pblock,
143 struct migrate_struct *lb)
144{
145 struct buffer_head *bh;
146 __le32 *i_data;
147 int i, retval = 0;
148 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
149
150 bh = sb_bread(inode->i_sb, pblock);
151 if (!bh)
152 return -EIO;
153
154 i_data = (__le32 *)bh->b_data;
155 for (i = 0; i < max_entries; i++) {
156 if (i_data[i]) {
157 retval = update_ind_extent_range(handle, inode,
158 le32_to_cpu(i_data[i]), lb);
159 if (retval)
160 break;
161 } else {
162 /* Only update the file block number */
163 lb->curr_block += max_entries;
164 }
165 }
166 put_bh(bh);
167 return retval;
168
169}
170
171static int update_tind_extent_range(handle_t *handle, struct inode *inode,
172 ext4_fsblk_t pblock,
173 struct migrate_struct *lb)
174{
175 struct buffer_head *bh;
176 __le32 *i_data;
177 int i, retval = 0;
178 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
179
180 bh = sb_bread(inode->i_sb, pblock);
181 if (!bh)
182 return -EIO;
183
184 i_data = (__le32 *)bh->b_data;
185 for (i = 0; i < max_entries; i++) {
186 if (i_data[i]) {
187 retval = update_dind_extent_range(handle, inode,
188 le32_to_cpu(i_data[i]), lb);
189 if (retval)
190 break;
191 } else {
192 /* Only update the file block number */
193 lb->curr_block += max_entries * max_entries;
194 }
195 }
196 put_bh(bh);
197 return retval;
198
199}
200
201static int extend_credit_for_blkdel(handle_t *handle, struct inode *inode)
202{
203 int retval = 0, needed;
204
205 if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
206 return 0;
207 /*
208 * We are freeing a blocks. During this we touch
209 * superblock, group descriptor and block bitmap.
210 * So allocate a credit of 3. We may update
211 * quota (user and group).
212 */
213 needed = 3 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
214
215 if (ext4_journal_extend(handle, needed) != 0)
216 retval = ext4_journal_restart(handle, needed);
217
218 return retval;
219}
220
221static int free_dind_blocks(handle_t *handle,
222 struct inode *inode, __le32 i_data)
223{
224 int i;
225 __le32 *tmp_idata;
226 struct buffer_head *bh;
227 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
228
229 bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
230 if (!bh)
231 return -EIO;
232
233 tmp_idata = (__le32 *)bh->b_data;
234 for (i = 0; i < max_entries; i++) {
235 if (tmp_idata[i]) {
236 extend_credit_for_blkdel(handle, inode);
237 ext4_free_blocks(handle, inode, NULL,
238 le32_to_cpu(tmp_idata[i]), 1,
239 EXT4_FREE_BLOCKS_METADATA |
240 EXT4_FREE_BLOCKS_FORGET);
241 }
242 }
243 put_bh(bh);
244 extend_credit_for_blkdel(handle, inode);
245 ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1,
246 EXT4_FREE_BLOCKS_METADATA |
247 EXT4_FREE_BLOCKS_FORGET);
248 return 0;
249}
250
251static int free_tind_blocks(handle_t *handle,
252 struct inode *inode, __le32 i_data)
253{
254 int i, retval = 0;
255 __le32 *tmp_idata;
256 struct buffer_head *bh;
257 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
258
259 bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
260 if (!bh)
261 return -EIO;
262
263 tmp_idata = (__le32 *)bh->b_data;
264 for (i = 0; i < max_entries; i++) {
265 if (tmp_idata[i]) {
266 retval = free_dind_blocks(handle,
267 inode, tmp_idata[i]);
268 if (retval) {
269 put_bh(bh);
270 return retval;
271 }
272 }
273 }
274 put_bh(bh);
275 extend_credit_for_blkdel(handle, inode);
276 ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1,
277 EXT4_FREE_BLOCKS_METADATA |
278 EXT4_FREE_BLOCKS_FORGET);
279 return 0;
280}
281
282static int free_ind_block(handle_t *handle, struct inode *inode, __le32 *i_data)
283{
284 int retval;
285
286 /* ei->i_data[EXT4_IND_BLOCK] */
287 if (i_data[0]) {
288 extend_credit_for_blkdel(handle, inode);
289 ext4_free_blocks(handle, inode, NULL,
290 le32_to_cpu(i_data[0]), 1,
291 EXT4_FREE_BLOCKS_METADATA |
292 EXT4_FREE_BLOCKS_FORGET);
293 }
294
295 /* ei->i_data[EXT4_DIND_BLOCK] */
296 if (i_data[1]) {
297 retval = free_dind_blocks(handle, inode, i_data[1]);
298 if (retval)
299 return retval;
300 }
301
302 /* ei->i_data[EXT4_TIND_BLOCK] */
303 if (i_data[2]) {
304 retval = free_tind_blocks(handle, inode, i_data[2]);
305 if (retval)
306 return retval;
307 }
308 return 0;
309}
310
311static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
312 struct inode *tmp_inode)
313{
314 int retval;
315 __le32 i_data[3];
316 struct ext4_inode_info *ei = EXT4_I(inode);
317 struct ext4_inode_info *tmp_ei = EXT4_I(tmp_inode);
318
319 /*
320 * One credit accounted for writing the
321 * i_data field of the original inode
322 */
323 retval = ext4_journal_extend(handle, 1);
324 if (retval) {
325 retval = ext4_journal_restart(handle, 1);
326 if (retval)
327 goto err_out;
328 }
329
330 i_data[0] = ei->i_data[EXT4_IND_BLOCK];
331 i_data[1] = ei->i_data[EXT4_DIND_BLOCK];
332 i_data[2] = ei->i_data[EXT4_TIND_BLOCK];
333
334 down_write(&EXT4_I(inode)->i_data_sem);
335 /*
336 * if EXT4_STATE_EXT_MIGRATE is cleared a block allocation
337 * happened after we started the migrate. We need to
338 * fail the migrate
339 */
340 if (!ext4_test_inode_state(inode, EXT4_STATE_EXT_MIGRATE)) {
341 retval = -EAGAIN;
342 up_write(&EXT4_I(inode)->i_data_sem);
343 goto err_out;
344 } else
345 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
346 /*
347 * We have the extent map build with the tmp inode.
348 * Now copy the i_data across
349 */
350 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
351 memcpy(ei->i_data, tmp_ei->i_data, sizeof(ei->i_data));
352
353 /*
354 * Update i_blocks with the new blocks that got
355 * allocated while adding extents for extent index
356 * blocks.
357 *
358 * While converting to extents we need not
359 * update the orignal inode i_blocks for extent blocks
360 * via quota APIs. The quota update happened via tmp_inode already.
361 */
362 spin_lock(&inode->i_lock);
363 inode->i_blocks += tmp_inode->i_blocks;
364 spin_unlock(&inode->i_lock);
365 up_write(&EXT4_I(inode)->i_data_sem);
366
367 /*
368 * We mark the inode dirty after, because we decrement the
369 * i_blocks when freeing the indirect meta-data blocks
370 */
371 retval = free_ind_block(handle, inode, i_data);
372 ext4_mark_inode_dirty(handle, inode);
373
374err_out:
375 return retval;
376}
377
378static int free_ext_idx(handle_t *handle, struct inode *inode,
379 struct ext4_extent_idx *ix)
380{
381 int i, retval = 0;
382 ext4_fsblk_t block;
383 struct buffer_head *bh;
384 struct ext4_extent_header *eh;
385
386 block = ext4_idx_pblock(ix);
387 bh = sb_bread(inode->i_sb, block);
388 if (!bh)
389 return -EIO;
390
391 eh = (struct ext4_extent_header *)bh->b_data;
392 if (eh->eh_depth != 0) {
393 ix = EXT_FIRST_INDEX(eh);
394 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
395 retval = free_ext_idx(handle, inode, ix);
396 if (retval)
397 break;
398 }
399 }
400 put_bh(bh);
401 extend_credit_for_blkdel(handle, inode);
402 ext4_free_blocks(handle, inode, NULL, block, 1,
403 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
404 return retval;
405}
406
407/*
408 * Free the extent meta data blocks only
409 */
410static int free_ext_block(handle_t *handle, struct inode *inode)
411{
412 int i, retval = 0;
413 struct ext4_inode_info *ei = EXT4_I(inode);
414 struct ext4_extent_header *eh = (struct ext4_extent_header *)ei->i_data;
415 struct ext4_extent_idx *ix;
416 if (eh->eh_depth == 0)
417 /*
418 * No extra blocks allocated for extent meta data
419 */
420 return 0;
421 ix = EXT_FIRST_INDEX(eh);
422 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
423 retval = free_ext_idx(handle, inode, ix);
424 if (retval)
425 return retval;
426 }
427 return retval;
428
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 handle = ext4_journal_start(inode,
459 EXT4_DATA_TRANS_BLOCKS(inode->i_sb) +
460 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
461 EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)
462 + 1);
463 if (IS_ERR(handle)) {
464 retval = PTR_ERR(handle);
465 return retval;
466 }
467 goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) *
468 EXT4_INODES_PER_GROUP(inode->i_sb)) + 1;
469 owner[0] = i_uid_read(inode);
470 owner[1] = i_gid_read(inode);
471 tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
472 S_IFREG, NULL, goal, owner);
473 if (IS_ERR(tmp_inode)) {
474 retval = PTR_ERR(tmp_inode);
475 ext4_journal_stop(handle);
476 return retval;
477 }
478 i_size_write(tmp_inode, i_size_read(inode));
479 /*
480 * Set the i_nlink to zero so it will be deleted later
481 * when we drop inode reference.
482 */
483 clear_nlink(tmp_inode);
484
485 ext4_ext_tree_init(handle, tmp_inode);
486 ext4_orphan_add(handle, tmp_inode);
487 ext4_journal_stop(handle);
488
489 /*
490 * start with one credit accounted for
491 * superblock modification.
492 *
493 * For the tmp_inode we already have committed the
494 * trascation that created the inode. Later as and
495 * when we add extents we extent the journal
496 */
497 /*
498 * Even though we take i_mutex we can still cause block
499 * allocation via mmap write to holes. If we have allocated
500 * new blocks we fail migrate. New block allocation will
501 * clear EXT4_STATE_EXT_MIGRATE flag. The flag is updated
502 * with i_data_sem held to prevent racing with block
503 * allocation.
504 */
505 down_read((&EXT4_I(inode)->i_data_sem));
506 ext4_set_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
507 up_read((&EXT4_I(inode)->i_data_sem));
508
509 handle = ext4_journal_start(inode, 1);
510 if (IS_ERR(handle)) {
511 /*
512 * It is impossible to update on-disk structures without
513 * a handle, so just rollback in-core changes and live other
514 * work to orphan_list_cleanup()
515 */
516 ext4_orphan_del(NULL, tmp_inode);
517 retval = PTR_ERR(handle);
518 goto out;
519 }
520
521 ei = EXT4_I(inode);
522 i_data = ei->i_data;
523 memset(&lb, 0, sizeof(lb));
524
525 /* 32 bit block address 4 bytes */
526 max_entries = inode->i_sb->s_blocksize >> 2;
527 for (i = 0; i < EXT4_NDIR_BLOCKS; i++) {
528 if (i_data[i]) {
529 retval = update_extent_range(handle, tmp_inode,
530 le32_to_cpu(i_data[i]), &lb);
531 if (retval)
532 goto err_out;
533 } else
534 lb.curr_block++;
535 }
536 if (i_data[EXT4_IND_BLOCK]) {
537 retval = update_ind_extent_range(handle, tmp_inode,
538 le32_to_cpu(i_data[EXT4_IND_BLOCK]), &lb);
539 if (retval)
540 goto err_out;
541 } else
542 lb.curr_block += max_entries;
543 if (i_data[EXT4_DIND_BLOCK]) {
544 retval = update_dind_extent_range(handle, tmp_inode,
545 le32_to_cpu(i_data[EXT4_DIND_BLOCK]), &lb);
546 if (retval)
547 goto err_out;
548 } else
549 lb.curr_block += max_entries * max_entries;
550 if (i_data[EXT4_TIND_BLOCK]) {
551 retval = update_tind_extent_range(handle, tmp_inode,
552 le32_to_cpu(i_data[EXT4_TIND_BLOCK]), &lb);
553 if (retval)
554 goto err_out;
555 }
556 /*
557 * Build the last extent
558 */
559 retval = finish_range(handle, tmp_inode, &lb);
560err_out:
561 if (retval)
562 /*
563 * Failure case delete the extent information with the
564 * tmp_inode
565 */
566 free_ext_block(handle, tmp_inode);
567 else {
568 retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode);
569 if (retval)
570 /*
571 * if we fail to swap inode data free the extent
572 * details of the tmp inode
573 */
574 free_ext_block(handle, tmp_inode);
575 }
576
577 /* We mark the tmp_inode dirty via ext4_ext_tree_init. */
578 if (ext4_journal_extend(handle, 1) != 0)
579 ext4_journal_restart(handle, 1);
580
581 /*
582 * Mark the tmp_inode as of size zero
583 */
584 i_size_write(tmp_inode, 0);
585
586 /*
587 * set the i_blocks count to zero
588 * so that the ext4_delete_inode does the
589 * right job
590 *
591 * We don't need to take the i_lock because
592 * the inode is not visible to user space.
593 */
594 tmp_inode->i_blocks = 0;
595
596 /* Reset the extent details */
597 ext4_ext_tree_init(handle, tmp_inode);
598 ext4_journal_stop(handle);
599out:
600 unlock_new_inode(tmp_inode);
601 iput(tmp_inode);
602
603 return retval;
604}