Line data Source code
1 : // SPDX-License-Identifier: LGPL-2.1
2 : /*
3 : * Copyright (c) 2008,2009 NEC Software Tohoku, Ltd.
4 : * Written by Takashi Sato <t-sato@yk.jp.nec.com>
5 : * Akira Fujita <a-fujita@rs.jp.nec.com>
6 : */
7 :
8 : #include <linux/fs.h>
9 : #include <linux/quotaops.h>
10 : #include <linux/slab.h>
11 : #include "ext4_jbd2.h"
12 : #include "ext4.h"
13 : #include "ext4_extents.h"
14 :
15 : /**
16 : * get_ext_path() - Find an extent path for designated logical block number.
17 : * @inode: inode to be searched
18 : * @lblock: logical block number to find an extent path
19 : * @ppath: pointer to an extent path pointer (for output)
20 : *
21 : * ext4_find_extent wrapper. Return 0 on success, or a negative error value
22 : * on failure.
23 : */
24 : static inline int
25 0 : get_ext_path(struct inode *inode, ext4_lblk_t lblock,
26 : struct ext4_ext_path **ppath)
27 : {
28 0 : struct ext4_ext_path *path;
29 :
30 0 : path = ext4_find_extent(inode, lblock, ppath, EXT4_EX_NOCACHE);
31 0 : if (IS_ERR(path))
32 0 : return PTR_ERR(path);
33 0 : if (path[ext_depth(inode)].p_ext == NULL) {
34 0 : ext4_ext_drop_refs(path);
35 0 : kfree(path);
36 0 : *ppath = NULL;
37 0 : return -ENODATA;
38 : }
39 0 : *ppath = path;
40 0 : return 0;
41 : }
42 :
43 : /**
44 : * ext4_double_down_write_data_sem() - write lock two inodes's i_data_sem
45 : * @first: inode to be locked
46 : * @second: inode to be locked
47 : *
48 : * Acquire write lock of i_data_sem of the two inodes
49 : */
50 : void
51 0 : ext4_double_down_write_data_sem(struct inode *first, struct inode *second)
52 : {
53 0 : if (first < second) {
54 0 : down_write(&EXT4_I(first)->i_data_sem);
55 0 : down_write_nested(&EXT4_I(second)->i_data_sem, I_DATA_SEM_OTHER);
56 : } else {
57 0 : down_write(&EXT4_I(second)->i_data_sem);
58 0 : down_write_nested(&EXT4_I(first)->i_data_sem, I_DATA_SEM_OTHER);
59 :
60 : }
61 0 : }
62 :
63 : /**
64 : * ext4_double_up_write_data_sem - Release two inodes' write lock of i_data_sem
65 : *
66 : * @orig_inode: original inode structure to be released its lock first
67 : * @donor_inode: donor inode structure to be released its lock second
68 : * Release write lock of i_data_sem of two inodes (orig and donor).
69 : */
70 : void
71 0 : ext4_double_up_write_data_sem(struct inode *orig_inode,
72 : struct inode *donor_inode)
73 : {
74 0 : up_write(&EXT4_I(orig_inode)->i_data_sem);
75 0 : up_write(&EXT4_I(donor_inode)->i_data_sem);
76 0 : }
77 :
78 : /**
79 : * mext_check_coverage - Check that all extents in range has the same type
80 : *
81 : * @inode: inode in question
82 : * @from: block offset of inode
83 : * @count: block count to be checked
84 : * @unwritten: extents expected to be unwritten
85 : * @err: pointer to save error value
86 : *
87 : * Return 1 if all extents in range has expected type, and zero otherwise.
88 : */
89 : static int
90 0 : mext_check_coverage(struct inode *inode, ext4_lblk_t from, ext4_lblk_t count,
91 : int unwritten, int *err)
92 : {
93 0 : struct ext4_ext_path *path = NULL;
94 0 : struct ext4_extent *ext;
95 0 : int ret = 0;
96 0 : ext4_lblk_t last = from + count;
97 0 : while (from < last) {
98 0 : *err = get_ext_path(inode, from, &path);
99 0 : if (*err)
100 0 : goto out;
101 0 : ext = path[ext_depth(inode)].p_ext;
102 0 : if (unwritten != ext4_ext_is_unwritten(ext))
103 0 : goto out;
104 0 : from += ext4_ext_get_actual_len(ext);
105 0 : ext4_ext_drop_refs(path);
106 : }
107 : ret = 1;
108 0 : out:
109 0 : ext4_ext_drop_refs(path);
110 0 : kfree(path);
111 0 : return ret;
112 : }
113 :
114 : /**
115 : * mext_page_double_lock - Grab and lock pages on both @inode1 and @inode2
116 : *
117 : * @inode1: the inode structure
118 : * @inode2: the inode structure
119 : * @index1: page index
120 : * @index2: page index
121 : * @page: result page vector
122 : *
123 : * Grab two locked pages for inode's by inode order
124 : */
125 : static int
126 0 : mext_page_double_lock(struct inode *inode1, struct inode *inode2,
127 : pgoff_t index1, pgoff_t index2, struct page *page[2])
128 : {
129 0 : struct address_space *mapping[2];
130 0 : unsigned fl = AOP_FLAG_NOFS;
131 :
132 0 : BUG_ON(!inode1 || !inode2);
133 0 : if (inode1 < inode2) {
134 0 : mapping[0] = inode1->i_mapping;
135 0 : mapping[1] = inode2->i_mapping;
136 : } else {
137 0 : swap(index1, index2);
138 0 : mapping[0] = inode2->i_mapping;
139 0 : mapping[1] = inode1->i_mapping;
140 : }
141 :
142 0 : page[0] = grab_cache_page_write_begin(mapping[0], index1, fl);
143 0 : if (!page[0])
144 : return -ENOMEM;
145 :
146 0 : page[1] = grab_cache_page_write_begin(mapping[1], index2, fl);
147 0 : if (!page[1]) {
148 0 : unlock_page(page[0]);
149 0 : put_page(page[0]);
150 0 : return -ENOMEM;
151 : }
152 : /*
153 : * grab_cache_page_write_begin() may not wait on page's writeback if
154 : * BDI not demand that. But it is reasonable to be very conservative
155 : * here and explicitly wait on page's writeback
156 : */
157 0 : wait_on_page_writeback(page[0]);
158 0 : wait_on_page_writeback(page[1]);
159 0 : if (inode1 > inode2)
160 0 : swap(page[0], page[1]);
161 :
162 : return 0;
163 : }
164 :
165 : /* Force page buffers uptodate w/o dropping page's lock */
166 : static int
167 0 : mext_page_mkuptodate(struct page *page, unsigned from, unsigned to)
168 : {
169 0 : struct inode *inode = page->mapping->host;
170 0 : sector_t block;
171 0 : struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
172 0 : unsigned int blocksize, block_start, block_end;
173 0 : int i, err, nr = 0, partial = 0;
174 0 : BUG_ON(!PageLocked(page));
175 0 : BUG_ON(PageWriteback(page));
176 :
177 0 : if (PageUptodate(page))
178 : return 0;
179 :
180 0 : blocksize = i_blocksize(inode);
181 0 : if (!page_has_buffers(page))
182 0 : create_empty_buffers(page, blocksize, 0);
183 :
184 0 : head = page_buffers(page);
185 0 : block = (sector_t)page->index << (PAGE_SHIFT - inode->i_blkbits);
186 0 : for (bh = head, block_start = 0; bh != head || !block_start;
187 0 : block++, block_start = block_end, bh = bh->b_this_page) {
188 0 : block_end = block_start + blocksize;
189 0 : if (block_end <= from || block_start >= to) {
190 0 : if (!buffer_uptodate(bh))
191 0 : partial = 1;
192 0 : continue;
193 : }
194 0 : if (buffer_uptodate(bh))
195 0 : continue;
196 0 : if (!buffer_mapped(bh)) {
197 0 : err = ext4_get_block(inode, block, bh, 0);
198 0 : if (err) {
199 0 : SetPageError(page);
200 0 : return err;
201 : }
202 0 : if (!buffer_mapped(bh)) {
203 0 : zero_user(page, block_start, blocksize);
204 0 : set_buffer_uptodate(bh);
205 0 : continue;
206 : }
207 : }
208 0 : BUG_ON(nr >= MAX_BUF_PER_PAGE);
209 0 : arr[nr++] = bh;
210 : }
211 : /* No io required */
212 0 : if (!nr)
213 0 : goto out;
214 :
215 0 : for (i = 0; i < nr; i++) {
216 0 : bh = arr[i];
217 0 : if (!bh_uptodate_or_lock(bh)) {
218 0 : err = ext4_read_bh(bh, 0, NULL);
219 0 : if (err)
220 0 : return err;
221 : }
222 : }
223 0 : out:
224 0 : if (!partial)
225 0 : SetPageUptodate(page);
226 : return 0;
227 : }
228 :
229 : /**
230 : * move_extent_per_page - Move extent data per page
231 : *
232 : * @o_filp: file structure of original file
233 : * @donor_inode: donor inode
234 : * @orig_page_offset: page index on original file
235 : * @donor_page_offset: page index on donor file
236 : * @data_offset_in_page: block index where data swapping starts
237 : * @block_len_in_page: the number of blocks to be swapped
238 : * @unwritten: orig extent is unwritten or not
239 : * @err: pointer to save return value
240 : *
241 : * Save the data in original inode blocks and replace original inode extents
242 : * with donor inode extents by calling ext4_swap_extents().
243 : * Finally, write out the saved data in new original inode blocks. Return
244 : * replaced block count.
245 : */
246 : static int
247 0 : move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
248 : pgoff_t orig_page_offset, pgoff_t donor_page_offset,
249 : int data_offset_in_page,
250 : int block_len_in_page, int unwritten, int *err)
251 : {
252 0 : struct inode *orig_inode = file_inode(o_filp);
253 0 : struct page *pagep[2] = {NULL, NULL};
254 0 : handle_t *handle;
255 0 : ext4_lblk_t orig_blk_offset, donor_blk_offset;
256 0 : unsigned long blocksize = orig_inode->i_sb->s_blocksize;
257 0 : unsigned int tmp_data_size, data_size, replaced_size;
258 0 : int i, err2, jblocks, retries = 0;
259 0 : int replaced_count = 0;
260 0 : int from = data_offset_in_page << orig_inode->i_blkbits;
261 0 : int blocks_per_page = PAGE_SIZE >> orig_inode->i_blkbits;
262 0 : struct super_block *sb = orig_inode->i_sb;
263 0 : struct buffer_head *bh = NULL;
264 :
265 : /*
266 : * It needs twice the amount of ordinary journal buffers because
267 : * inode and donor_inode may change each different metadata blocks.
268 : */
269 : again:
270 0 : *err = 0;
271 0 : jblocks = ext4_writepage_trans_blocks(orig_inode) * 2;
272 0 : handle = ext4_journal_start(orig_inode, EXT4_HT_MOVE_EXTENTS, jblocks);
273 0 : if (IS_ERR(handle)) {
274 0 : *err = PTR_ERR(handle);
275 0 : return 0;
276 : }
277 :
278 0 : orig_blk_offset = orig_page_offset * blocks_per_page +
279 : data_offset_in_page;
280 :
281 0 : donor_blk_offset = donor_page_offset * blocks_per_page +
282 : data_offset_in_page;
283 :
284 : /* Calculate data_size */
285 0 : if ((orig_blk_offset + block_len_in_page - 1) ==
286 0 : ((orig_inode->i_size - 1) >> orig_inode->i_blkbits)) {
287 : /* Replace the last block */
288 0 : tmp_data_size = orig_inode->i_size & (blocksize - 1);
289 : /*
290 : * If data_size equal zero, it shows data_size is multiples of
291 : * blocksize. So we set appropriate value.
292 : */
293 0 : if (tmp_data_size == 0)
294 0 : tmp_data_size = blocksize;
295 :
296 0 : data_size = tmp_data_size +
297 0 : ((block_len_in_page - 1) << orig_inode->i_blkbits);
298 : } else
299 0 : data_size = block_len_in_page << orig_inode->i_blkbits;
300 :
301 0 : replaced_size = data_size;
302 :
303 0 : *err = mext_page_double_lock(orig_inode, donor_inode, orig_page_offset,
304 : donor_page_offset, pagep);
305 0 : if (unlikely(*err < 0))
306 0 : goto stop_journal;
307 : /*
308 : * If orig extent was unwritten it can become initialized
309 : * at any time after i_data_sem was dropped, in order to
310 : * serialize with delalloc we have recheck extent while we
311 : * hold page's lock, if it is still the case data copy is not
312 : * necessary, just swap data blocks between orig and donor.
313 : */
314 0 : if (unwritten) {
315 0 : ext4_double_down_write_data_sem(orig_inode, donor_inode);
316 : /* If any of extents in range became initialized we have to
317 : * fallback to data copying */
318 0 : unwritten = mext_check_coverage(orig_inode, orig_blk_offset,
319 : block_len_in_page, 1, err);
320 0 : if (*err)
321 0 : goto drop_data_sem;
322 :
323 0 : unwritten &= mext_check_coverage(donor_inode, donor_blk_offset,
324 : block_len_in_page, 1, err);
325 0 : if (*err)
326 0 : goto drop_data_sem;
327 :
328 0 : if (!unwritten) {
329 0 : ext4_double_up_write_data_sem(orig_inode, donor_inode);
330 0 : goto data_copy;
331 : }
332 0 : if ((page_has_private(pagep[0]) &&
333 0 : !try_to_release_page(pagep[0], 0)) ||
334 0 : (page_has_private(pagep[1]) &&
335 0 : !try_to_release_page(pagep[1], 0))) {
336 0 : *err = -EBUSY;
337 0 : goto drop_data_sem;
338 : }
339 0 : replaced_count = ext4_swap_extents(handle, orig_inode,
340 : donor_inode, orig_blk_offset,
341 : donor_blk_offset,
342 : block_len_in_page, 1, err);
343 0 : drop_data_sem:
344 0 : ext4_double_up_write_data_sem(orig_inode, donor_inode);
345 0 : goto unlock_pages;
346 : }
347 0 : data_copy:
348 0 : *err = mext_page_mkuptodate(pagep[0], from, from + replaced_size);
349 0 : if (*err)
350 0 : goto unlock_pages;
351 :
352 : /* At this point all buffers in range are uptodate, old mapping layout
353 : * is no longer required, try to drop it now. */
354 0 : if ((page_has_private(pagep[0]) && !try_to_release_page(pagep[0], 0)) ||
355 0 : (page_has_private(pagep[1]) && !try_to_release_page(pagep[1], 0))) {
356 0 : *err = -EBUSY;
357 0 : goto unlock_pages;
358 : }
359 0 : ext4_double_down_write_data_sem(orig_inode, donor_inode);
360 0 : replaced_count = ext4_swap_extents(handle, orig_inode, donor_inode,
361 : orig_blk_offset, donor_blk_offset,
362 : block_len_in_page, 1, err);
363 0 : ext4_double_up_write_data_sem(orig_inode, donor_inode);
364 0 : if (*err) {
365 0 : if (replaced_count) {
366 0 : block_len_in_page = replaced_count;
367 0 : replaced_size =
368 0 : block_len_in_page << orig_inode->i_blkbits;
369 : } else
370 0 : goto unlock_pages;
371 : }
372 : /* Perform all necessary steps similar write_begin()/write_end()
373 : * but keeping in mind that i_size will not change */
374 0 : if (!page_has_buffers(pagep[0]))
375 0 : create_empty_buffers(pagep[0], 1 << orig_inode->i_blkbits, 0);
376 0 : bh = page_buffers(pagep[0]);
377 0 : for (i = 0; i < data_offset_in_page; i++)
378 0 : bh = bh->b_this_page;
379 0 : for (i = 0; i < block_len_in_page; i++) {
380 0 : *err = ext4_get_block(orig_inode, orig_blk_offset + i, bh, 0);
381 0 : if (*err < 0)
382 : break;
383 0 : bh = bh->b_this_page;
384 : }
385 0 : if (!*err)
386 0 : *err = block_commit_write(pagep[0], from, from + replaced_size);
387 :
388 0 : if (unlikely(*err < 0))
389 0 : goto repair_branches;
390 :
391 : /* Even in case of data=writeback it is reasonable to pin
392 : * inode to transaction, to prevent unexpected data loss */
393 0 : *err = ext4_jbd2_inode_add_write(handle, orig_inode,
394 0 : (loff_t)orig_page_offset << PAGE_SHIFT, replaced_size);
395 :
396 0 : unlock_pages:
397 0 : unlock_page(pagep[0]);
398 0 : put_page(pagep[0]);
399 0 : unlock_page(pagep[1]);
400 0 : put_page(pagep[1]);
401 0 : stop_journal:
402 0 : ext4_journal_stop(handle);
403 0 : if (*err == -ENOSPC &&
404 0 : ext4_should_retry_alloc(sb, &retries))
405 0 : goto again;
406 : /* Buffer was busy because probably is pinned to journal transaction,
407 : * force transaction commit may help to free it. */
408 0 : if (*err == -EBUSY && retries++ < 4 && EXT4_SB(sb)->s_journal &&
409 0 : jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal))
410 0 : goto again;
411 : return replaced_count;
412 :
413 0 : repair_branches:
414 : /*
415 : * This should never ever happen!
416 : * Extents are swapped already, but we are not able to copy data.
417 : * Try to swap extents to it's original places
418 : */
419 0 : ext4_double_down_write_data_sem(orig_inode, donor_inode);
420 0 : replaced_count = ext4_swap_extents(handle, donor_inode, orig_inode,
421 : orig_blk_offset, donor_blk_offset,
422 : block_len_in_page, 0, &err2);
423 0 : ext4_double_up_write_data_sem(orig_inode, donor_inode);
424 0 : if (replaced_count != block_len_in_page) {
425 0 : ext4_error_inode_block(orig_inode, (sector_t)(orig_blk_offset),
426 : EIO, "Unable to copy data block,"
427 : " data will be lost.");
428 0 : *err = -EIO;
429 : }
430 0 : replaced_count = 0;
431 0 : goto unlock_pages;
432 : }
433 :
434 : /**
435 : * mext_check_arguments - Check whether move extent can be done
436 : *
437 : * @orig_inode: original inode
438 : * @donor_inode: donor inode
439 : * @orig_start: logical start offset in block for orig
440 : * @donor_start: logical start offset in block for donor
441 : * @len: the number of blocks to be moved
442 : *
443 : * Check the arguments of ext4_move_extents() whether the files can be
444 : * exchanged with each other.
445 : * Return 0 on success, or a negative error value on failure.
446 : */
447 : static int
448 0 : mext_check_arguments(struct inode *orig_inode,
449 : struct inode *donor_inode, __u64 orig_start,
450 : __u64 donor_start, __u64 *len)
451 : {
452 0 : __u64 orig_eof, donor_eof;
453 0 : unsigned int blkbits = orig_inode->i_blkbits;
454 0 : unsigned int blocksize = 1 << blkbits;
455 :
456 0 : orig_eof = (i_size_read(orig_inode) + blocksize - 1) >> blkbits;
457 0 : donor_eof = (i_size_read(donor_inode) + blocksize - 1) >> blkbits;
458 :
459 :
460 0 : if (donor_inode->i_mode & (S_ISUID|S_ISGID)) {
461 : ext4_debug("ext4 move extent: suid or sgid is set"
462 : " to donor file [ino:orig %lu, donor %lu]\n",
463 : orig_inode->i_ino, donor_inode->i_ino);
464 : return -EINVAL;
465 : }
466 :
467 0 : if (IS_IMMUTABLE(donor_inode) || IS_APPEND(donor_inode))
468 : return -EPERM;
469 :
470 : /* Ext4 move extent does not support swapfile */
471 0 : if (IS_SWAPFILE(orig_inode) || IS_SWAPFILE(donor_inode)) {
472 : ext4_debug("ext4 move extent: The argument files should "
473 : "not be swapfile [ino:orig %lu, donor %lu]\n",
474 : orig_inode->i_ino, donor_inode->i_ino);
475 : return -EBUSY;
476 : }
477 :
478 0 : if (ext4_is_quota_file(orig_inode) && ext4_is_quota_file(donor_inode)) {
479 : ext4_debug("ext4 move extent: The argument files should "
480 : "not be quota files [ino:orig %lu, donor %lu]\n",
481 : orig_inode->i_ino, donor_inode->i_ino);
482 : return -EBUSY;
483 : }
484 :
485 : /* Ext4 move extent supports only extent based file */
486 0 : if (!(ext4_test_inode_flag(orig_inode, EXT4_INODE_EXTENTS))) {
487 : ext4_debug("ext4 move extent: orig file is not extents "
488 : "based file [ino:orig %lu]\n", orig_inode->i_ino);
489 : return -EOPNOTSUPP;
490 0 : } else if (!(ext4_test_inode_flag(donor_inode, EXT4_INODE_EXTENTS))) {
491 : ext4_debug("ext4 move extent: donor file is not extents "
492 : "based file [ino:donor %lu]\n", donor_inode->i_ino);
493 : return -EOPNOTSUPP;
494 : }
495 :
496 0 : if ((!orig_inode->i_size) || (!donor_inode->i_size)) {
497 : ext4_debug("ext4 move extent: File size is 0 byte\n");
498 : return -EINVAL;
499 : }
500 :
501 : /* Start offset should be same */
502 0 : if ((orig_start & ~(PAGE_MASK >> orig_inode->i_blkbits)) !=
503 : (donor_start & ~(PAGE_MASK >> orig_inode->i_blkbits))) {
504 : ext4_debug("ext4 move extent: orig and donor's start "
505 : "offsets are not aligned [ino:orig %lu, donor %lu]\n",
506 : orig_inode->i_ino, donor_inode->i_ino);
507 : return -EINVAL;
508 : }
509 :
510 0 : if ((orig_start >= EXT_MAX_BLOCKS) ||
511 0 : (donor_start >= EXT_MAX_BLOCKS) ||
512 0 : (*len > EXT_MAX_BLOCKS) ||
513 0 : (donor_start + *len >= EXT_MAX_BLOCKS) ||
514 0 : (orig_start + *len >= EXT_MAX_BLOCKS)) {
515 : ext4_debug("ext4 move extent: Can't handle over [%u] blocks "
516 : "[ino:orig %lu, donor %lu]\n", EXT_MAX_BLOCKS,
517 : orig_inode->i_ino, donor_inode->i_ino);
518 : return -EINVAL;
519 : }
520 0 : if (orig_eof <= orig_start)
521 0 : *len = 0;
522 0 : else if (orig_eof < orig_start + *len - 1)
523 0 : *len = orig_eof - orig_start;
524 0 : if (donor_eof <= donor_start)
525 0 : *len = 0;
526 0 : else if (donor_eof < donor_start + *len - 1)
527 0 : *len = donor_eof - donor_start;
528 0 : if (!*len) {
529 0 : ext4_debug("ext4 move extent: len should not be 0 "
530 : "[ino:orig %lu, donor %lu]\n", orig_inode->i_ino,
531 : donor_inode->i_ino);
532 0 : return -EINVAL;
533 : }
534 :
535 : return 0;
536 : }
537 :
538 : /**
539 : * ext4_move_extents - Exchange the specified range of a file
540 : *
541 : * @o_filp: file structure of the original file
542 : * @d_filp: file structure of the donor file
543 : * @orig_blk: start offset in block for orig
544 : * @donor_blk: start offset in block for donor
545 : * @len: the number of blocks to be moved
546 : * @moved_len: moved block length
547 : *
548 : * This function returns 0 and moved block length is set in moved_len
549 : * if succeed, otherwise returns error value.
550 : *
551 : */
552 : int
553 0 : ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk,
554 : __u64 donor_blk, __u64 len, __u64 *moved_len)
555 : {
556 0 : struct inode *orig_inode = file_inode(o_filp);
557 0 : struct inode *donor_inode = file_inode(d_filp);
558 0 : struct ext4_ext_path *path = NULL;
559 0 : int blocks_per_page = PAGE_SIZE >> orig_inode->i_blkbits;
560 0 : ext4_lblk_t o_end, o_start = orig_blk;
561 0 : ext4_lblk_t d_start = donor_blk;
562 0 : int ret;
563 :
564 0 : if (orig_inode->i_sb != donor_inode->i_sb) {
565 : ext4_debug("ext4 move extent: The argument files "
566 : "should be in same FS [ino:orig %lu, donor %lu]\n",
567 : orig_inode->i_ino, donor_inode->i_ino);
568 : return -EINVAL;
569 : }
570 :
571 : /* orig and donor should be different inodes */
572 0 : if (orig_inode == donor_inode) {
573 : ext4_debug("ext4 move extent: The argument files should not "
574 : "be same inode [ino:orig %lu, donor %lu]\n",
575 : orig_inode->i_ino, donor_inode->i_ino);
576 : return -EINVAL;
577 : }
578 :
579 : /* Regular file check */
580 0 : if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) {
581 : ext4_debug("ext4 move extent: The argument files should be "
582 : "regular file [ino:orig %lu, donor %lu]\n",
583 : orig_inode->i_ino, donor_inode->i_ino);
584 : return -EINVAL;
585 : }
586 :
587 : /* TODO: it's not obvious how to swap blocks for inodes with full
588 : journaling enabled */
589 0 : if (ext4_should_journal_data(orig_inode) ||
590 0 : ext4_should_journal_data(donor_inode)) {
591 0 : ext4_msg(orig_inode->i_sb, KERN_ERR,
592 : "Online defrag not supported with data journaling");
593 0 : return -EOPNOTSUPP;
594 : }
595 :
596 0 : if (IS_ENCRYPTED(orig_inode) || IS_ENCRYPTED(donor_inode)) {
597 0 : ext4_msg(orig_inode->i_sb, KERN_ERR,
598 : "Online defrag not supported for encrypted files");
599 0 : return -EOPNOTSUPP;
600 : }
601 :
602 : /* Protect orig and donor inodes against a truncate */
603 0 : lock_two_nondirectories(orig_inode, donor_inode);
604 :
605 : /* Wait for all existing dio workers */
606 0 : inode_dio_wait(orig_inode);
607 0 : inode_dio_wait(donor_inode);
608 :
609 : /* Protect extent tree against block allocations via delalloc */
610 0 : ext4_double_down_write_data_sem(orig_inode, donor_inode);
611 : /* Check the filesystem environment whether move_extent can be done */
612 0 : ret = mext_check_arguments(orig_inode, donor_inode, orig_blk,
613 : donor_blk, &len);
614 0 : if (ret)
615 0 : goto out;
616 0 : o_end = o_start + len;
617 :
618 0 : while (o_start < o_end) {
619 0 : struct ext4_extent *ex;
620 0 : ext4_lblk_t cur_blk, next_blk;
621 0 : pgoff_t orig_page_index, donor_page_index;
622 0 : int offset_in_page;
623 0 : int unwritten, cur_len;
624 :
625 0 : ret = get_ext_path(orig_inode, o_start, &path);
626 0 : if (ret)
627 0 : goto out;
628 0 : ex = path[path->p_depth].p_ext;
629 0 : next_blk = ext4_ext_next_allocated_block(path);
630 0 : cur_blk = le32_to_cpu(ex->ee_block);
631 0 : cur_len = ext4_ext_get_actual_len(ex);
632 : /* Check hole before the start pos */
633 0 : if (cur_blk + cur_len - 1 < o_start) {
634 0 : if (next_blk == EXT_MAX_BLOCKS) {
635 0 : o_start = o_end;
636 0 : ret = -ENODATA;
637 0 : goto out;
638 : }
639 0 : d_start += next_blk - o_start;
640 0 : o_start = next_blk;
641 0 : continue;
642 : /* Check hole after the start pos */
643 0 : } else if (cur_blk > o_start) {
644 : /* Skip hole */
645 0 : d_start += cur_blk - o_start;
646 0 : o_start = cur_blk;
647 : /* Extent inside requested range ?*/
648 0 : if (cur_blk >= o_end)
649 0 : goto out;
650 : } else { /* in_range(o_start, o_blk, o_len) */
651 0 : cur_len += cur_blk - o_start;
652 : }
653 0 : unwritten = ext4_ext_is_unwritten(ex);
654 0 : if (o_end - o_start < cur_len)
655 0 : cur_len = o_end - o_start;
656 :
657 0 : orig_page_index = o_start >> (PAGE_SHIFT -
658 0 : orig_inode->i_blkbits);
659 0 : donor_page_index = d_start >> (PAGE_SHIFT -
660 0 : donor_inode->i_blkbits);
661 0 : offset_in_page = o_start % blocks_per_page;
662 0 : if (cur_len > blocks_per_page- offset_in_page)
663 : cur_len = blocks_per_page - offset_in_page;
664 : /*
665 : * Up semaphore to avoid following problems:
666 : * a. transaction deadlock among ext4_journal_start,
667 : * ->write_begin via pagefault, and jbd2_journal_commit
668 : * b. racing with ->readpage, ->write_begin, and ext4_get_block
669 : * in move_extent_per_page
670 : */
671 0 : ext4_double_up_write_data_sem(orig_inode, donor_inode);
672 : /* Swap original branches with new branches */
673 0 : move_extent_per_page(o_filp, donor_inode,
674 : orig_page_index, donor_page_index,
675 : offset_in_page, cur_len,
676 : unwritten, &ret);
677 0 : ext4_double_down_write_data_sem(orig_inode, donor_inode);
678 0 : if (ret < 0)
679 : break;
680 0 : o_start += cur_len;
681 0 : d_start += cur_len;
682 : }
683 0 : *moved_len = o_start - orig_blk;
684 0 : if (*moved_len > len)
685 0 : *moved_len = len;
686 :
687 0 : out:
688 0 : if (*moved_len) {
689 0 : ext4_discard_preallocations(orig_inode, 0);
690 0 : ext4_discard_preallocations(donor_inode, 0);
691 : }
692 :
693 0 : ext4_ext_drop_refs(path);
694 0 : kfree(path);
695 0 : ext4_double_up_write_data_sem(orig_inode, donor_inode);
696 0 : unlock_two_nondirectories(orig_inode, donor_inode);
697 :
698 0 : return ret;
699 : }
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