Loading...
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}
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/module.h>
16#include <linux/slab.h>
17#include "ext4_jbd2.h"
18#include "ext4_extents.h"
19
20/*
21 * The contiguous blocks details which can be
22 * represented by a single extent
23 */
24struct list_blocks_struct {
25 ext4_lblk_t first_block, last_block;
26 ext4_fsblk_t first_pblock, last_pblock;
27};
28
29static int finish_range(handle_t *handle, struct inode *inode,
30 struct list_blocks_struct *lb)
31
32{
33 int retval = 0, needed;
34 struct ext4_extent newext;
35 struct ext4_ext_path *path;
36 if (lb->first_pblock == 0)
37 return 0;
38
39 /* Add the extent to temp inode*/
40 newext.ee_block = cpu_to_le32(lb->first_block);
41 newext.ee_len = cpu_to_le16(lb->last_block - lb->first_block + 1);
42 ext4_ext_store_pblock(&newext, lb->first_pblock);
43 path = ext4_ext_find_extent(inode, lb->first_block, NULL);
44
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 retval = ext4_journal_restart(handle, needed);
66 if (retval)
67 goto err_out;
68 } else if (needed) {
69 retval = ext4_journal_extend(handle, needed);
70 if (retval) {
71 /*
72 * IF not able to extend the journal restart the journal
73 */
74 retval = ext4_journal_restart(handle, needed);
75 if (retval)
76 goto err_out;
77 }
78 }
79 retval = ext4_ext_insert_extent(handle, inode, path, &newext, 0);
80err_out:
81 if (path) {
82 ext4_ext_drop_refs(path);
83 kfree(path);
84 }
85 lb->first_pblock = 0;
86 return retval;
87}
88
89static int update_extent_range(handle_t *handle, struct inode *inode,
90 ext4_fsblk_t pblock, ext4_lblk_t blk_num,
91 struct list_blocks_struct *lb)
92{
93 int retval;
94 /*
95 * See if we can add on to the existing range (if it exists)
96 */
97 if (lb->first_pblock &&
98 (lb->last_pblock+1 == pblock) &&
99 (lb->last_block+1 == blk_num)) {
100 lb->last_pblock = pblock;
101 lb->last_block = blk_num;
102 return 0;
103 }
104 /*
105 * Start a new range.
106 */
107 retval = finish_range(handle, inode, lb);
108 lb->first_pblock = lb->last_pblock = pblock;
109 lb->first_block = lb->last_block = blk_num;
110
111 return retval;
112}
113
114static int update_ind_extent_range(handle_t *handle, struct inode *inode,
115 ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
116 struct list_blocks_struct *lb)
117{
118 struct buffer_head *bh;
119 __le32 *i_data;
120 int i, retval = 0;
121 ext4_lblk_t blk_count = *blk_nump;
122 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
123
124 if (!pblock) {
125 /* Only update the file block number */
126 *blk_nump += max_entries;
127 return 0;
128 }
129
130 bh = sb_bread(inode->i_sb, pblock);
131 if (!bh)
132 return -EIO;
133
134 i_data = (__le32 *)bh->b_data;
135 for (i = 0; i < max_entries; i++, blk_count++) {
136 if (i_data[i]) {
137 retval = update_extent_range(handle, inode,
138 le32_to_cpu(i_data[i]),
139 blk_count, lb);
140 if (retval)
141 break;
142 }
143 }
144
145 /* Update the file block number */
146 *blk_nump = blk_count;
147 put_bh(bh);
148 return retval;
149
150}
151
152static int update_dind_extent_range(handle_t *handle, struct inode *inode,
153 ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
154 struct list_blocks_struct *lb)
155{
156 struct buffer_head *bh;
157 __le32 *i_data;
158 int i, retval = 0;
159 ext4_lblk_t blk_count = *blk_nump;
160 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
161
162 if (!pblock) {
163 /* Only update the file block number */
164 *blk_nump += max_entries * max_entries;
165 return 0;
166 }
167 bh = sb_bread(inode->i_sb, pblock);
168 if (!bh)
169 return -EIO;
170
171 i_data = (__le32 *)bh->b_data;
172 for (i = 0; i < max_entries; i++) {
173 if (i_data[i]) {
174 retval = update_ind_extent_range(handle, inode,
175 le32_to_cpu(i_data[i]),
176 &blk_count, lb);
177 if (retval)
178 break;
179 } else {
180 /* Only update the file block number */
181 blk_count += max_entries;
182 }
183 }
184
185 /* Update the file block number */
186 *blk_nump = blk_count;
187 put_bh(bh);
188 return retval;
189
190}
191
192static int update_tind_extent_range(handle_t *handle, struct inode *inode,
193 ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
194 struct list_blocks_struct *lb)
195{
196 struct buffer_head *bh;
197 __le32 *i_data;
198 int i, retval = 0;
199 ext4_lblk_t blk_count = *blk_nump;
200 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
201
202 if (!pblock) {
203 /* Only update the file block number */
204 *blk_nump += max_entries * max_entries * max_entries;
205 return 0;
206 }
207 bh = sb_bread(inode->i_sb, pblock);
208 if (!bh)
209 return -EIO;
210
211 i_data = (__le32 *)bh->b_data;
212 for (i = 0; i < max_entries; i++) {
213 if (i_data[i]) {
214 retval = update_dind_extent_range(handle, inode,
215 le32_to_cpu(i_data[i]),
216 &blk_count, lb);
217 if (retval)
218 break;
219 } else
220 /* Only update the file block number */
221 blk_count += max_entries * max_entries;
222 }
223 /* Update the file block number */
224 *blk_nump = blk_count;
225 put_bh(bh);
226 return retval;
227
228}
229
230static int extend_credit_for_blkdel(handle_t *handle, struct inode *inode)
231{
232 int retval = 0, needed;
233
234 if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
235 return 0;
236 /*
237 * We are freeing a blocks. During this we touch
238 * superblock, group descriptor and block bitmap.
239 * So allocate a credit of 3. We may update
240 * quota (user and group).
241 */
242 needed = 3 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
243
244 if (ext4_journal_extend(handle, needed) != 0)
245 retval = ext4_journal_restart(handle, needed);
246
247 return retval;
248}
249
250static int free_dind_blocks(handle_t *handle,
251 struct inode *inode, __le32 i_data)
252{
253 int i;
254 __le32 *tmp_idata;
255 struct buffer_head *bh;
256 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
257
258 bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
259 if (!bh)
260 return -EIO;
261
262 tmp_idata = (__le32 *)bh->b_data;
263 for (i = 0; i < max_entries; i++) {
264 if (tmp_idata[i]) {
265 extend_credit_for_blkdel(handle, inode);
266 ext4_free_blocks(handle, inode, NULL,
267 le32_to_cpu(tmp_idata[i]), 1,
268 EXT4_FREE_BLOCKS_METADATA |
269 EXT4_FREE_BLOCKS_FORGET);
270 }
271 }
272 put_bh(bh);
273 extend_credit_for_blkdel(handle, inode);
274 ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1,
275 EXT4_FREE_BLOCKS_METADATA |
276 EXT4_FREE_BLOCKS_FORGET);
277 return 0;
278}
279
280static int free_tind_blocks(handle_t *handle,
281 struct inode *inode, __le32 i_data)
282{
283 int i, retval = 0;
284 __le32 *tmp_idata;
285 struct buffer_head *bh;
286 unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
287
288 bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
289 if (!bh)
290 return -EIO;
291
292 tmp_idata = (__le32 *)bh->b_data;
293 for (i = 0; i < max_entries; i++) {
294 if (tmp_idata[i]) {
295 retval = free_dind_blocks(handle,
296 inode, tmp_idata[i]);
297 if (retval) {
298 put_bh(bh);
299 return retval;
300 }
301 }
302 }
303 put_bh(bh);
304 extend_credit_for_blkdel(handle, inode);
305 ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1,
306 EXT4_FREE_BLOCKS_METADATA |
307 EXT4_FREE_BLOCKS_FORGET);
308 return 0;
309}
310
311static int free_ind_block(handle_t *handle, struct inode *inode, __le32 *i_data)
312{
313 int retval;
314
315 /* ei->i_data[EXT4_IND_BLOCK] */
316 if (i_data[0]) {
317 extend_credit_for_blkdel(handle, inode);
318 ext4_free_blocks(handle, inode, NULL,
319 le32_to_cpu(i_data[0]), 1,
320 EXT4_FREE_BLOCKS_METADATA |
321 EXT4_FREE_BLOCKS_FORGET);
322 }
323
324 /* ei->i_data[EXT4_DIND_BLOCK] */
325 if (i_data[1]) {
326 retval = free_dind_blocks(handle, inode, i_data[1]);
327 if (retval)
328 return retval;
329 }
330
331 /* ei->i_data[EXT4_TIND_BLOCK] */
332 if (i_data[2]) {
333 retval = free_tind_blocks(handle, inode, i_data[2]);
334 if (retval)
335 return retval;
336 }
337 return 0;
338}
339
340static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
341 struct inode *tmp_inode)
342{
343 int retval;
344 __le32 i_data[3];
345 struct ext4_inode_info *ei = EXT4_I(inode);
346 struct ext4_inode_info *tmp_ei = EXT4_I(tmp_inode);
347
348 /*
349 * One credit accounted for writing the
350 * i_data field of the original inode
351 */
352 retval = ext4_journal_extend(handle, 1);
353 if (retval) {
354 retval = ext4_journal_restart(handle, 1);
355 if (retval)
356 goto err_out;
357 }
358
359 i_data[0] = ei->i_data[EXT4_IND_BLOCK];
360 i_data[1] = ei->i_data[EXT4_DIND_BLOCK];
361 i_data[2] = ei->i_data[EXT4_TIND_BLOCK];
362
363 down_write(&EXT4_I(inode)->i_data_sem);
364 /*
365 * if EXT4_STATE_EXT_MIGRATE is cleared a block allocation
366 * happened after we started the migrate. We need to
367 * fail the migrate
368 */
369 if (!ext4_test_inode_state(inode, EXT4_STATE_EXT_MIGRATE)) {
370 retval = -EAGAIN;
371 up_write(&EXT4_I(inode)->i_data_sem);
372 goto err_out;
373 } else
374 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
375 /*
376 * We have the extent map build with the tmp inode.
377 * Now copy the i_data across
378 */
379 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
380 memcpy(ei->i_data, tmp_ei->i_data, sizeof(ei->i_data));
381
382 /*
383 * Update i_blocks with the new blocks that got
384 * allocated while adding extents for extent index
385 * blocks.
386 *
387 * While converting to extents we need not
388 * update the orignal inode i_blocks for extent blocks
389 * via quota APIs. The quota update happened via tmp_inode already.
390 */
391 spin_lock(&inode->i_lock);
392 inode->i_blocks += tmp_inode->i_blocks;
393 spin_unlock(&inode->i_lock);
394 up_write(&EXT4_I(inode)->i_data_sem);
395
396 /*
397 * We mark the inode dirty after, because we decrement the
398 * i_blocks when freeing the indirect meta-data blocks
399 */
400 retval = free_ind_block(handle, inode, i_data);
401 ext4_mark_inode_dirty(handle, inode);
402
403err_out:
404 return retval;
405}
406
407static int free_ext_idx(handle_t *handle, struct inode *inode,
408 struct ext4_extent_idx *ix)
409{
410 int i, retval = 0;
411 ext4_fsblk_t block;
412 struct buffer_head *bh;
413 struct ext4_extent_header *eh;
414
415 block = ext4_idx_pblock(ix);
416 bh = sb_bread(inode->i_sb, block);
417 if (!bh)
418 return -EIO;
419
420 eh = (struct ext4_extent_header *)bh->b_data;
421 if (eh->eh_depth != 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 break;
427 }
428 }
429 put_bh(bh);
430 extend_credit_for_blkdel(handle, inode);
431 ext4_free_blocks(handle, inode, NULL, block, 1,
432 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
433 return retval;
434}
435
436/*
437 * Free the extent meta data blocks only
438 */
439static int free_ext_block(handle_t *handle, struct inode *inode)
440{
441 int i, retval = 0;
442 struct ext4_inode_info *ei = EXT4_I(inode);
443 struct ext4_extent_header *eh = (struct ext4_extent_header *)ei->i_data;
444 struct ext4_extent_idx *ix;
445 if (eh->eh_depth == 0)
446 /*
447 * No extra blocks allocated for extent meta data
448 */
449 return 0;
450 ix = EXT_FIRST_INDEX(eh);
451 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
452 retval = free_ext_idx(handle, inode, ix);
453 if (retval)
454 return retval;
455 }
456 return retval;
457
458}
459
460int ext4_ext_migrate(struct inode *inode)
461{
462 handle_t *handle;
463 int retval = 0, i;
464 __le32 *i_data;
465 ext4_lblk_t blk_count = 0;
466 struct ext4_inode_info *ei;
467 struct inode *tmp_inode = NULL;
468 struct list_blocks_struct lb;
469 unsigned long max_entries;
470 __u32 goal;
471
472 /*
473 * If the filesystem does not support extents, or the inode
474 * already is extent-based, error out.
475 */
476 if (!EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb,
477 EXT4_FEATURE_INCOMPAT_EXTENTS) ||
478 (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
479 return -EINVAL;
480
481 if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0)
482 /*
483 * don't migrate fast symlink
484 */
485 return retval;
486
487 handle = ext4_journal_start(inode,
488 EXT4_DATA_TRANS_BLOCKS(inode->i_sb) +
489 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
490 EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)
491 + 1);
492 if (IS_ERR(handle)) {
493 retval = PTR_ERR(handle);
494 return retval;
495 }
496 goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) *
497 EXT4_INODES_PER_GROUP(inode->i_sb)) + 1;
498 tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
499 S_IFREG, NULL, goal);
500 if (IS_ERR(tmp_inode)) {
501 retval = -ENOMEM;
502 ext4_journal_stop(handle);
503 return retval;
504 }
505 i_size_write(tmp_inode, i_size_read(inode));
506 /*
507 * Set the i_nlink to zero so it will be deleted later
508 * when we drop inode reference.
509 */
510 tmp_inode->i_nlink = 0;
511
512 ext4_ext_tree_init(handle, tmp_inode);
513 ext4_orphan_add(handle, tmp_inode);
514 ext4_journal_stop(handle);
515
516 /*
517 * start with one credit accounted for
518 * superblock modification.
519 *
520 * For the tmp_inode we already have committed the
521 * trascation that created the inode. Later as and
522 * when we add extents we extent the journal
523 */
524 /*
525 * Even though we take i_mutex we can still cause block
526 * allocation via mmap write to holes. If we have allocated
527 * new blocks we fail migrate. New block allocation will
528 * clear EXT4_STATE_EXT_MIGRATE flag. The flag is updated
529 * with i_data_sem held to prevent racing with block
530 * allocation.
531 */
532 down_read((&EXT4_I(inode)->i_data_sem));
533 ext4_set_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
534 up_read((&EXT4_I(inode)->i_data_sem));
535
536 handle = ext4_journal_start(inode, 1);
537 if (IS_ERR(handle)) {
538 /*
539 * It is impossible to update on-disk structures without
540 * a handle, so just rollback in-core changes and live other
541 * work to orphan_list_cleanup()
542 */
543 ext4_orphan_del(NULL, tmp_inode);
544 retval = PTR_ERR(handle);
545 goto out;
546 }
547
548 ei = EXT4_I(inode);
549 i_data = ei->i_data;
550 memset(&lb, 0, sizeof(lb));
551
552 /* 32 bit block address 4 bytes */
553 max_entries = inode->i_sb->s_blocksize >> 2;
554 for (i = 0; i < EXT4_NDIR_BLOCKS; i++, blk_count++) {
555 if (i_data[i]) {
556 retval = update_extent_range(handle, tmp_inode,
557 le32_to_cpu(i_data[i]),
558 blk_count, &lb);
559 if (retval)
560 goto err_out;
561 }
562 }
563 if (i_data[EXT4_IND_BLOCK]) {
564 retval = update_ind_extent_range(handle, tmp_inode,
565 le32_to_cpu(i_data[EXT4_IND_BLOCK]),
566 &blk_count, &lb);
567 if (retval)
568 goto err_out;
569 } else
570 blk_count += max_entries;
571 if (i_data[EXT4_DIND_BLOCK]) {
572 retval = update_dind_extent_range(handle, tmp_inode,
573 le32_to_cpu(i_data[EXT4_DIND_BLOCK]),
574 &blk_count, &lb);
575 if (retval)
576 goto err_out;
577 } else
578 blk_count += max_entries * max_entries;
579 if (i_data[EXT4_TIND_BLOCK]) {
580 retval = update_tind_extent_range(handle, tmp_inode,
581 le32_to_cpu(i_data[EXT4_TIND_BLOCK]),
582 &blk_count, &lb);
583 if (retval)
584 goto err_out;
585 }
586 /*
587 * Build the last extent
588 */
589 retval = finish_range(handle, tmp_inode, &lb);
590err_out:
591 if (retval)
592 /*
593 * Failure case delete the extent information with the
594 * tmp_inode
595 */
596 free_ext_block(handle, tmp_inode);
597 else {
598 retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode);
599 if (retval)
600 /*
601 * if we fail to swap inode data free the extent
602 * details of the tmp inode
603 */
604 free_ext_block(handle, tmp_inode);
605 }
606
607 /* We mark the tmp_inode dirty via ext4_ext_tree_init. */
608 if (ext4_journal_extend(handle, 1) != 0)
609 ext4_journal_restart(handle, 1);
610
611 /*
612 * Mark the tmp_inode as of size zero
613 */
614 i_size_write(tmp_inode, 0);
615
616 /*
617 * set the i_blocks count to zero
618 * so that the ext4_delete_inode does the
619 * right job
620 *
621 * We don't need to take the i_lock because
622 * the inode is not visible to user space.
623 */
624 tmp_inode->i_blocks = 0;
625
626 /* Reset the extent details */
627 ext4_ext_tree_init(handle, tmp_inode);
628 ext4_journal_stop(handle);
629out:
630 unlock_new_inode(tmp_inode);
631 iput(tmp_inode);
632
633 return retval;
634}