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 <linux/sched/mm.h> |
12 | #include "ext4_jbd2.h" |
13 | #include "ext4.h" |
14 | #include "ext4_extents.h" |
15 | |
16 | /** |
17 | * get_ext_path() - Find an extent path for designated logical block number. |
18 | * @inode: inode to be searched |
19 | * @lblock: logical block number to find an extent path |
20 | * @ppath: pointer to an extent path pointer (for output) |
21 | * |
22 | * ext4_find_extent wrapper. Return 0 on success, or a negative error value |
23 | * on failure. |
24 | */ |
25 | static inline int |
26 | get_ext_path(struct inode *inode, ext4_lblk_t lblock, |
27 | struct ext4_ext_path **ppath) |
28 | { |
29 | struct ext4_ext_path *path; |
30 | |
31 | path = ext4_find_extent(inode, lblock, ppath, EXT4_EX_NOCACHE); |
32 | if (IS_ERR(ptr: path)) |
33 | return PTR_ERR(ptr: path); |
34 | if (path[ext_depth(inode)].p_ext == NULL) { |
35 | ext4_free_ext_path(path); |
36 | *ppath = NULL; |
37 | return -ENODATA; |
38 | } |
39 | *ppath = path; |
40 | 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 | ext4_double_down_write_data_sem(struct inode *first, struct inode *second) |
52 | { |
53 | if (first < second) { |
54 | down_write(sem: &EXT4_I(inode: first)->i_data_sem); |
55 | down_write_nested(sem: &EXT4_I(inode: second)->i_data_sem, subclass: I_DATA_SEM_OTHER); |
56 | } else { |
57 | down_write(sem: &EXT4_I(inode: second)->i_data_sem); |
58 | down_write_nested(sem: &EXT4_I(inode: first)->i_data_sem, subclass: I_DATA_SEM_OTHER); |
59 | |
60 | } |
61 | } |
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 | ext4_double_up_write_data_sem(struct inode *orig_inode, |
72 | struct inode *donor_inode) |
73 | { |
74 | up_write(sem: &EXT4_I(inode: orig_inode)->i_data_sem); |
75 | up_write(sem: &EXT4_I(inode: donor_inode)->i_data_sem); |
76 | } |
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 | mext_check_coverage(struct inode *inode, ext4_lblk_t from, ext4_lblk_t count, |
91 | int unwritten, int *err) |
92 | { |
93 | struct ext4_ext_path *path = NULL; |
94 | struct ext4_extent *ext; |
95 | int ret = 0; |
96 | ext4_lblk_t last = from + count; |
97 | while (from < last) { |
98 | *err = get_ext_path(inode, lblock: from, ppath: &path); |
99 | if (*err) |
100 | goto out; |
101 | ext = path[ext_depth(inode)].p_ext; |
102 | if (unwritten != ext4_ext_is_unwritten(ext)) |
103 | goto out; |
104 | from += ext4_ext_get_actual_len(ext); |
105 | } |
106 | ret = 1; |
107 | out: |
108 | ext4_free_ext_path(path); |
109 | return ret; |
110 | } |
111 | |
112 | /** |
113 | * mext_folio_double_lock - Grab and lock folio on both @inode1 and @inode2 |
114 | * |
115 | * @inode1: the inode structure |
116 | * @inode2: the inode structure |
117 | * @index1: folio index |
118 | * @index2: folio index |
119 | * @folio: result folio vector |
120 | * |
121 | * Grab two locked folio for inode's by inode order |
122 | */ |
123 | static int |
124 | mext_folio_double_lock(struct inode *inode1, struct inode *inode2, |
125 | pgoff_t index1, pgoff_t index2, struct folio *folio[2]) |
126 | { |
127 | struct address_space *mapping[2]; |
128 | unsigned int flags; |
129 | |
130 | BUG_ON(!inode1 || !inode2); |
131 | if (inode1 < inode2) { |
132 | mapping[0] = inode1->i_mapping; |
133 | mapping[1] = inode2->i_mapping; |
134 | } else { |
135 | swap(index1, index2); |
136 | mapping[0] = inode2->i_mapping; |
137 | mapping[1] = inode1->i_mapping; |
138 | } |
139 | |
140 | flags = memalloc_nofs_save(); |
141 | folio[0] = __filemap_get_folio(mapping: mapping[0], index: index1, FGP_WRITEBEGIN, |
142 | gfp: mapping_gfp_mask(mapping: mapping[0])); |
143 | if (IS_ERR(ptr: folio[0])) { |
144 | memalloc_nofs_restore(flags); |
145 | return PTR_ERR(ptr: folio[0]); |
146 | } |
147 | |
148 | folio[1] = __filemap_get_folio(mapping: mapping[1], index: index2, FGP_WRITEBEGIN, |
149 | gfp: mapping_gfp_mask(mapping: mapping[1])); |
150 | memalloc_nofs_restore(flags); |
151 | if (IS_ERR(ptr: folio[1])) { |
152 | folio_unlock(folio: folio[0]); |
153 | folio_put(folio: folio[0]); |
154 | return PTR_ERR(ptr: folio[1]); |
155 | } |
156 | /* |
157 | * __filemap_get_folio() may not wait on folio's writeback if |
158 | * BDI not demand that. But it is reasonable to be very conservative |
159 | * here and explicitly wait on folio's writeback |
160 | */ |
161 | folio_wait_writeback(folio: folio[0]); |
162 | folio_wait_writeback(folio: folio[1]); |
163 | if (inode1 > inode2) |
164 | swap(folio[0], folio[1]); |
165 | |
166 | return 0; |
167 | } |
168 | |
169 | /* Force page buffers uptodate w/o dropping page's lock */ |
170 | static int |
171 | mext_page_mkuptodate(struct folio *folio, unsigned from, unsigned to) |
172 | { |
173 | struct inode *inode = folio->mapping->host; |
174 | sector_t block; |
175 | struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE]; |
176 | unsigned int blocksize, block_start, block_end; |
177 | int i, err, nr = 0, partial = 0; |
178 | BUG_ON(!folio_test_locked(folio)); |
179 | BUG_ON(folio_test_writeback(folio)); |
180 | |
181 | if (folio_test_uptodate(folio)) |
182 | return 0; |
183 | |
184 | blocksize = i_blocksize(node: inode); |
185 | head = folio_buffers(folio); |
186 | if (!head) |
187 | head = create_empty_buffers(folio, blocksize, b_state: 0); |
188 | |
189 | block = (sector_t)folio->index << (PAGE_SHIFT - inode->i_blkbits); |
190 | for (bh = head, block_start = 0; bh != head || !block_start; |
191 | block++, block_start = block_end, bh = bh->b_this_page) { |
192 | block_end = block_start + blocksize; |
193 | if (block_end <= from || block_start >= to) { |
194 | if (!buffer_uptodate(bh)) |
195 | partial = 1; |
196 | continue; |
197 | } |
198 | if (buffer_uptodate(bh)) |
199 | continue; |
200 | if (!buffer_mapped(bh)) { |
201 | err = ext4_get_block(inode, iblock: block, bh_result: bh, create: 0); |
202 | if (err) { |
203 | folio_set_error(folio); |
204 | return err; |
205 | } |
206 | if (!buffer_mapped(bh)) { |
207 | folio_zero_range(folio, start: block_start, length: blocksize); |
208 | set_buffer_uptodate(bh); |
209 | continue; |
210 | } |
211 | } |
212 | BUG_ON(nr >= MAX_BUF_PER_PAGE); |
213 | arr[nr++] = bh; |
214 | } |
215 | /* No io required */ |
216 | if (!nr) |
217 | goto out; |
218 | |
219 | for (i = 0; i < nr; i++) { |
220 | bh = arr[i]; |
221 | if (!bh_uptodate_or_lock(bh)) { |
222 | err = ext4_read_bh(bh, op_flags: 0, NULL); |
223 | if (err) |
224 | return err; |
225 | } |
226 | } |
227 | out: |
228 | if (!partial) |
229 | folio_mark_uptodate(folio); |
230 | return 0; |
231 | } |
232 | |
233 | /** |
234 | * move_extent_per_page - Move extent data per page |
235 | * |
236 | * @o_filp: file structure of original file |
237 | * @donor_inode: donor inode |
238 | * @orig_page_offset: page index on original file |
239 | * @donor_page_offset: page index on donor file |
240 | * @data_offset_in_page: block index where data swapping starts |
241 | * @block_len_in_page: the number of blocks to be swapped |
242 | * @unwritten: orig extent is unwritten or not |
243 | * @err: pointer to save return value |
244 | * |
245 | * Save the data in original inode blocks and replace original inode extents |
246 | * with donor inode extents by calling ext4_swap_extents(). |
247 | * Finally, write out the saved data in new original inode blocks. Return |
248 | * replaced block count. |
249 | */ |
250 | static int |
251 | move_extent_per_page(struct file *o_filp, struct inode *donor_inode, |
252 | pgoff_t orig_page_offset, pgoff_t donor_page_offset, |
253 | int data_offset_in_page, |
254 | int block_len_in_page, int unwritten, int *err) |
255 | { |
256 | struct inode *orig_inode = file_inode(f: o_filp); |
257 | struct folio *folio[2] = {NULL, NULL}; |
258 | handle_t *handle; |
259 | ext4_lblk_t orig_blk_offset, donor_blk_offset; |
260 | unsigned long blocksize = orig_inode->i_sb->s_blocksize; |
261 | unsigned int tmp_data_size, data_size, replaced_size; |
262 | int i, err2, jblocks, retries = 0; |
263 | int replaced_count = 0; |
264 | int from = data_offset_in_page << orig_inode->i_blkbits; |
265 | int blocks_per_page = PAGE_SIZE >> orig_inode->i_blkbits; |
266 | struct super_block *sb = orig_inode->i_sb; |
267 | struct buffer_head *bh = NULL; |
268 | |
269 | /* |
270 | * It needs twice the amount of ordinary journal buffers because |
271 | * inode and donor_inode may change each different metadata blocks. |
272 | */ |
273 | again: |
274 | *err = 0; |
275 | jblocks = ext4_writepage_trans_blocks(orig_inode) * 2; |
276 | handle = ext4_journal_start(orig_inode, EXT4_HT_MOVE_EXTENTS, jblocks); |
277 | if (IS_ERR(ptr: handle)) { |
278 | *err = PTR_ERR(ptr: handle); |
279 | return 0; |
280 | } |
281 | |
282 | orig_blk_offset = orig_page_offset * blocks_per_page + |
283 | data_offset_in_page; |
284 | |
285 | donor_blk_offset = donor_page_offset * blocks_per_page + |
286 | data_offset_in_page; |
287 | |
288 | /* Calculate data_size */ |
289 | if ((orig_blk_offset + block_len_in_page - 1) == |
290 | ((orig_inode->i_size - 1) >> orig_inode->i_blkbits)) { |
291 | /* Replace the last block */ |
292 | tmp_data_size = orig_inode->i_size & (blocksize - 1); |
293 | /* |
294 | * If data_size equal zero, it shows data_size is multiples of |
295 | * blocksize. So we set appropriate value. |
296 | */ |
297 | if (tmp_data_size == 0) |
298 | tmp_data_size = blocksize; |
299 | |
300 | data_size = tmp_data_size + |
301 | ((block_len_in_page - 1) << orig_inode->i_blkbits); |
302 | } else |
303 | data_size = block_len_in_page << orig_inode->i_blkbits; |
304 | |
305 | replaced_size = data_size; |
306 | |
307 | *err = mext_folio_double_lock(inode1: orig_inode, inode2: donor_inode, index1: orig_page_offset, |
308 | index2: donor_page_offset, folio); |
309 | if (unlikely(*err < 0)) |
310 | goto stop_journal; |
311 | /* |
312 | * If orig extent was unwritten it can become initialized |
313 | * at any time after i_data_sem was dropped, in order to |
314 | * serialize with delalloc we have recheck extent while we |
315 | * hold page's lock, if it is still the case data copy is not |
316 | * necessary, just swap data blocks between orig and donor. |
317 | */ |
318 | |
319 | VM_BUG_ON_FOLIO(folio_test_large(folio[0]), folio[0]); |
320 | VM_BUG_ON_FOLIO(folio_test_large(folio[1]), folio[1]); |
321 | VM_BUG_ON_FOLIO(folio_nr_pages(folio[0]) != folio_nr_pages(folio[1]), folio[1]); |
322 | |
323 | if (unwritten) { |
324 | ext4_double_down_write_data_sem(first: orig_inode, second: donor_inode); |
325 | /* If any of extents in range became initialized we have to |
326 | * fallback to data copying */ |
327 | unwritten = mext_check_coverage(inode: orig_inode, from: orig_blk_offset, |
328 | count: block_len_in_page, unwritten: 1, err); |
329 | if (*err) |
330 | goto drop_data_sem; |
331 | |
332 | unwritten &= mext_check_coverage(inode: donor_inode, from: donor_blk_offset, |
333 | count: block_len_in_page, unwritten: 1, err); |
334 | if (*err) |
335 | goto drop_data_sem; |
336 | |
337 | if (!unwritten) { |
338 | ext4_double_up_write_data_sem(orig_inode, donor_inode); |
339 | goto data_copy; |
340 | } |
341 | if (!filemap_release_folio(folio: folio[0], gfp: 0) || |
342 | !filemap_release_folio(folio: folio[1], gfp: 0)) { |
343 | *err = -EBUSY; |
344 | goto drop_data_sem; |
345 | } |
346 | replaced_count = ext4_swap_extents(handle, inode1: orig_inode, |
347 | inode2: donor_inode, lblk1: orig_blk_offset, |
348 | lblk2: donor_blk_offset, |
349 | count: block_len_in_page, mark_unwritten: 1, err); |
350 | drop_data_sem: |
351 | ext4_double_up_write_data_sem(orig_inode, donor_inode); |
352 | goto unlock_folios; |
353 | } |
354 | data_copy: |
355 | *err = mext_page_mkuptodate(folio: folio[0], from, to: from + replaced_size); |
356 | if (*err) |
357 | goto unlock_folios; |
358 | |
359 | /* At this point all buffers in range are uptodate, old mapping layout |
360 | * is no longer required, try to drop it now. */ |
361 | if (!filemap_release_folio(folio: folio[0], gfp: 0) || |
362 | !filemap_release_folio(folio: folio[1], gfp: 0)) { |
363 | *err = -EBUSY; |
364 | goto unlock_folios; |
365 | } |
366 | ext4_double_down_write_data_sem(first: orig_inode, second: donor_inode); |
367 | replaced_count = ext4_swap_extents(handle, inode1: orig_inode, inode2: donor_inode, |
368 | lblk1: orig_blk_offset, lblk2: donor_blk_offset, |
369 | count: block_len_in_page, mark_unwritten: 1, err); |
370 | ext4_double_up_write_data_sem(orig_inode, donor_inode); |
371 | if (*err) { |
372 | if (replaced_count) { |
373 | block_len_in_page = replaced_count; |
374 | replaced_size = |
375 | block_len_in_page << orig_inode->i_blkbits; |
376 | } else |
377 | goto unlock_folios; |
378 | } |
379 | /* Perform all necessary steps similar write_begin()/write_end() |
380 | * but keeping in mind that i_size will not change */ |
381 | bh = folio_buffers(folio[0]); |
382 | if (!bh) |
383 | bh = create_empty_buffers(folio: folio[0], |
384 | blocksize: 1 << orig_inode->i_blkbits, b_state: 0); |
385 | for (i = 0; i < data_offset_in_page; i++) |
386 | bh = bh->b_this_page; |
387 | for (i = 0; i < block_len_in_page; i++) { |
388 | *err = ext4_get_block(inode: orig_inode, iblock: orig_blk_offset + i, bh_result: bh, create: 0); |
389 | if (*err < 0) |
390 | goto repair_branches; |
391 | bh = bh->b_this_page; |
392 | } |
393 | |
394 | block_commit_write(page: &folio[0]->page, from, to: from + replaced_size); |
395 | |
396 | /* Even in case of data=writeback it is reasonable to pin |
397 | * inode to transaction, to prevent unexpected data loss */ |
398 | *err = ext4_jbd2_inode_add_write(handle, inode: orig_inode, |
399 | start_byte: (loff_t)orig_page_offset << PAGE_SHIFT, length: replaced_size); |
400 | |
401 | unlock_folios: |
402 | folio_unlock(folio: folio[0]); |
403 | folio_put(folio: folio[0]); |
404 | folio_unlock(folio: folio[1]); |
405 | folio_put(folio: folio[1]); |
406 | stop_journal: |
407 | ext4_journal_stop(handle); |
408 | if (*err == -ENOSPC && |
409 | ext4_should_retry_alloc(sb, retries: &retries)) |
410 | goto again; |
411 | /* Buffer was busy because probably is pinned to journal transaction, |
412 | * force transaction commit may help to free it. */ |
413 | if (*err == -EBUSY && retries++ < 4 && EXT4_SB(sb)->s_journal && |
414 | jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal)) |
415 | goto again; |
416 | return replaced_count; |
417 | |
418 | repair_branches: |
419 | /* |
420 | * This should never ever happen! |
421 | * Extents are swapped already, but we are not able to copy data. |
422 | * Try to swap extents to it's original places |
423 | */ |
424 | ext4_double_down_write_data_sem(first: orig_inode, second: donor_inode); |
425 | replaced_count = ext4_swap_extents(handle, inode1: donor_inode, inode2: orig_inode, |
426 | lblk1: orig_blk_offset, lblk2: donor_blk_offset, |
427 | count: block_len_in_page, mark_unwritten: 0, err: &err2); |
428 | ext4_double_up_write_data_sem(orig_inode, donor_inode); |
429 | if (replaced_count != block_len_in_page) { |
430 | ext4_error_inode_block(orig_inode, (sector_t)(orig_blk_offset), |
431 | EIO, "Unable to copy data block," |
432 | " data will be lost." ); |
433 | *err = -EIO; |
434 | } |
435 | replaced_count = 0; |
436 | goto unlock_folios; |
437 | } |
438 | |
439 | /** |
440 | * mext_check_arguments - Check whether move extent can be done |
441 | * |
442 | * @orig_inode: original inode |
443 | * @donor_inode: donor inode |
444 | * @orig_start: logical start offset in block for orig |
445 | * @donor_start: logical start offset in block for donor |
446 | * @len: the number of blocks to be moved |
447 | * |
448 | * Check the arguments of ext4_move_extents() whether the files can be |
449 | * exchanged with each other. |
450 | * Return 0 on success, or a negative error value on failure. |
451 | */ |
452 | static int |
453 | mext_check_arguments(struct inode *orig_inode, |
454 | struct inode *donor_inode, __u64 orig_start, |
455 | __u64 donor_start, __u64 *len) |
456 | { |
457 | __u64 orig_eof, donor_eof; |
458 | unsigned int blkbits = orig_inode->i_blkbits; |
459 | unsigned int blocksize = 1 << blkbits; |
460 | |
461 | orig_eof = (i_size_read(inode: orig_inode) + blocksize - 1) >> blkbits; |
462 | donor_eof = (i_size_read(inode: donor_inode) + blocksize - 1) >> blkbits; |
463 | |
464 | |
465 | if (donor_inode->i_mode & (S_ISUID|S_ISGID)) { |
466 | ext4_debug("ext4 move extent: suid or sgid is set" |
467 | " to donor file [ino:orig %lu, donor %lu]\n" , |
468 | orig_inode->i_ino, donor_inode->i_ino); |
469 | return -EINVAL; |
470 | } |
471 | |
472 | if (IS_IMMUTABLE(donor_inode) || IS_APPEND(donor_inode)) |
473 | return -EPERM; |
474 | |
475 | /* Ext4 move extent does not support swap files */ |
476 | if (IS_SWAPFILE(orig_inode) || IS_SWAPFILE(donor_inode)) { |
477 | ext4_debug("ext4 move extent: The argument files should not be swap files [ino:orig %lu, donor %lu]\n" , |
478 | orig_inode->i_ino, donor_inode->i_ino); |
479 | return -ETXTBSY; |
480 | } |
481 | |
482 | if (ext4_is_quota_file(inode: orig_inode) && ext4_is_quota_file(inode: donor_inode)) { |
483 | ext4_debug("ext4 move extent: The argument files should not be quota files [ino:orig %lu, donor %lu]\n" , |
484 | orig_inode->i_ino, donor_inode->i_ino); |
485 | return -EOPNOTSUPP; |
486 | } |
487 | |
488 | /* Ext4 move extent supports only extent based file */ |
489 | if (!(ext4_test_inode_flag(inode: orig_inode, bit: EXT4_INODE_EXTENTS))) { |
490 | ext4_debug("ext4 move extent: orig file is not extents " |
491 | "based file [ino:orig %lu]\n" , orig_inode->i_ino); |
492 | return -EOPNOTSUPP; |
493 | } else if (!(ext4_test_inode_flag(inode: donor_inode, bit: EXT4_INODE_EXTENTS))) { |
494 | ext4_debug("ext4 move extent: donor file is not extents " |
495 | "based file [ino:donor %lu]\n" , donor_inode->i_ino); |
496 | return -EOPNOTSUPP; |
497 | } |
498 | |
499 | if ((!orig_inode->i_size) || (!donor_inode->i_size)) { |
500 | ext4_debug("ext4 move extent: File size is 0 byte\n" ); |
501 | return -EINVAL; |
502 | } |
503 | |
504 | /* Start offset should be same */ |
505 | if ((orig_start & ~(PAGE_MASK >> orig_inode->i_blkbits)) != |
506 | (donor_start & ~(PAGE_MASK >> orig_inode->i_blkbits))) { |
507 | ext4_debug("ext4 move extent: orig and donor's start " |
508 | "offsets are not aligned [ino:orig %lu, donor %lu]\n" , |
509 | orig_inode->i_ino, donor_inode->i_ino); |
510 | return -EINVAL; |
511 | } |
512 | |
513 | if ((orig_start >= EXT_MAX_BLOCKS) || |
514 | (donor_start >= EXT_MAX_BLOCKS) || |
515 | (*len > EXT_MAX_BLOCKS) || |
516 | (donor_start + *len >= EXT_MAX_BLOCKS) || |
517 | (orig_start + *len >= EXT_MAX_BLOCKS)) { |
518 | ext4_debug("ext4 move extent: Can't handle over [%u] blocks " |
519 | "[ino:orig %lu, donor %lu]\n" , EXT_MAX_BLOCKS, |
520 | orig_inode->i_ino, donor_inode->i_ino); |
521 | return -EINVAL; |
522 | } |
523 | if (orig_eof <= orig_start) |
524 | *len = 0; |
525 | else if (orig_eof < orig_start + *len - 1) |
526 | *len = orig_eof - orig_start; |
527 | if (donor_eof <= donor_start) |
528 | *len = 0; |
529 | else if (donor_eof < donor_start + *len - 1) |
530 | *len = donor_eof - donor_start; |
531 | if (!*len) { |
532 | ext4_debug("ext4 move extent: len should not be 0 " |
533 | "[ino:orig %lu, donor %lu]\n" , orig_inode->i_ino, |
534 | donor_inode->i_ino); |
535 | return -EINVAL; |
536 | } |
537 | |
538 | return 0; |
539 | } |
540 | |
541 | /** |
542 | * ext4_move_extents - Exchange the specified range of a file |
543 | * |
544 | * @o_filp: file structure of the original file |
545 | * @d_filp: file structure of the donor file |
546 | * @orig_blk: start offset in block for orig |
547 | * @donor_blk: start offset in block for donor |
548 | * @len: the number of blocks to be moved |
549 | * @moved_len: moved block length |
550 | * |
551 | * This function returns 0 and moved block length is set in moved_len |
552 | * if succeed, otherwise returns error value. |
553 | * |
554 | */ |
555 | int |
556 | ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk, |
557 | __u64 donor_blk, __u64 len, __u64 *moved_len) |
558 | { |
559 | struct inode *orig_inode = file_inode(f: o_filp); |
560 | struct inode *donor_inode = file_inode(f: d_filp); |
561 | struct ext4_ext_path *path = NULL; |
562 | int blocks_per_page = PAGE_SIZE >> orig_inode->i_blkbits; |
563 | ext4_lblk_t o_end, o_start = orig_blk; |
564 | ext4_lblk_t d_start = donor_blk; |
565 | int ret; |
566 | |
567 | if (orig_inode->i_sb != donor_inode->i_sb) { |
568 | ext4_debug("ext4 move extent: The argument files " |
569 | "should be in same FS [ino:orig %lu, donor %lu]\n" , |
570 | orig_inode->i_ino, donor_inode->i_ino); |
571 | return -EINVAL; |
572 | } |
573 | |
574 | /* orig and donor should be different inodes */ |
575 | if (orig_inode == donor_inode) { |
576 | ext4_debug("ext4 move extent: The argument files should not " |
577 | "be same inode [ino:orig %lu, donor %lu]\n" , |
578 | orig_inode->i_ino, donor_inode->i_ino); |
579 | return -EINVAL; |
580 | } |
581 | |
582 | /* Regular file check */ |
583 | if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) { |
584 | ext4_debug("ext4 move extent: The argument files should be " |
585 | "regular file [ino:orig %lu, donor %lu]\n" , |
586 | orig_inode->i_ino, donor_inode->i_ino); |
587 | return -EINVAL; |
588 | } |
589 | |
590 | /* TODO: it's not obvious how to swap blocks for inodes with full |
591 | journaling enabled */ |
592 | if (ext4_should_journal_data(inode: orig_inode) || |
593 | ext4_should_journal_data(inode: donor_inode)) { |
594 | ext4_msg(orig_inode->i_sb, KERN_ERR, |
595 | "Online defrag not supported with data journaling" ); |
596 | return -EOPNOTSUPP; |
597 | } |
598 | |
599 | if (IS_ENCRYPTED(orig_inode) || IS_ENCRYPTED(donor_inode)) { |
600 | ext4_msg(orig_inode->i_sb, KERN_ERR, |
601 | "Online defrag not supported for encrypted files" ); |
602 | return -EOPNOTSUPP; |
603 | } |
604 | |
605 | /* Protect orig and donor inodes against a truncate */ |
606 | lock_two_nondirectories(orig_inode, donor_inode); |
607 | |
608 | /* Wait for all existing dio workers */ |
609 | inode_dio_wait(inode: orig_inode); |
610 | inode_dio_wait(inode: donor_inode); |
611 | |
612 | /* Protect extent tree against block allocations via delalloc */ |
613 | ext4_double_down_write_data_sem(first: orig_inode, second: donor_inode); |
614 | /* Check the filesystem environment whether move_extent can be done */ |
615 | ret = mext_check_arguments(orig_inode, donor_inode, orig_start: orig_blk, |
616 | donor_start: donor_blk, len: &len); |
617 | if (ret) |
618 | goto out; |
619 | o_end = o_start + len; |
620 | |
621 | *moved_len = 0; |
622 | while (o_start < o_end) { |
623 | struct ext4_extent *ex; |
624 | ext4_lblk_t cur_blk, next_blk; |
625 | pgoff_t orig_page_index, donor_page_index; |
626 | int offset_in_page; |
627 | int unwritten, cur_len; |
628 | |
629 | ret = get_ext_path(inode: orig_inode, lblock: o_start, ppath: &path); |
630 | if (ret) |
631 | goto out; |
632 | ex = path[path->p_depth].p_ext; |
633 | cur_blk = le32_to_cpu(ex->ee_block); |
634 | cur_len = ext4_ext_get_actual_len(ext: ex); |
635 | /* Check hole before the start pos */ |
636 | if (cur_blk + cur_len - 1 < o_start) { |
637 | next_blk = ext4_ext_next_allocated_block(path); |
638 | if (next_blk == EXT_MAX_BLOCKS) { |
639 | ret = -ENODATA; |
640 | goto out; |
641 | } |
642 | d_start += next_blk - o_start; |
643 | o_start = next_blk; |
644 | continue; |
645 | /* Check hole after the start pos */ |
646 | } else if (cur_blk > o_start) { |
647 | /* Skip hole */ |
648 | d_start += cur_blk - o_start; |
649 | o_start = cur_blk; |
650 | /* Extent inside requested range ?*/ |
651 | if (cur_blk >= o_end) |
652 | goto out; |
653 | } else { /* in_range(o_start, o_blk, o_len) */ |
654 | cur_len += cur_blk - o_start; |
655 | } |
656 | unwritten = ext4_ext_is_unwritten(ext: ex); |
657 | if (o_end - o_start < cur_len) |
658 | cur_len = o_end - o_start; |
659 | |
660 | orig_page_index = o_start >> (PAGE_SHIFT - |
661 | orig_inode->i_blkbits); |
662 | donor_page_index = d_start >> (PAGE_SHIFT - |
663 | donor_inode->i_blkbits); |
664 | offset_in_page = o_start % blocks_per_page; |
665 | if (cur_len > blocks_per_page - offset_in_page) |
666 | cur_len = blocks_per_page - offset_in_page; |
667 | /* |
668 | * Up semaphore to avoid following problems: |
669 | * a. transaction deadlock among ext4_journal_start, |
670 | * ->write_begin via pagefault, and jbd2_journal_commit |
671 | * b. racing with ->read_folio, ->write_begin, and |
672 | * ext4_get_block in move_extent_per_page |
673 | */ |
674 | ext4_double_up_write_data_sem(orig_inode, donor_inode); |
675 | /* Swap original branches with new branches */ |
676 | *moved_len += move_extent_per_page(o_filp, donor_inode, |
677 | orig_page_offset: orig_page_index, donor_page_offset: donor_page_index, |
678 | data_offset_in_page: offset_in_page, block_len_in_page: cur_len, |
679 | unwritten, err: &ret); |
680 | ext4_double_down_write_data_sem(first: orig_inode, second: donor_inode); |
681 | if (ret < 0) |
682 | break; |
683 | o_start += cur_len; |
684 | d_start += cur_len; |
685 | } |
686 | |
687 | out: |
688 | if (*moved_len) { |
689 | ext4_discard_preallocations(orig_inode); |
690 | ext4_discard_preallocations(donor_inode); |
691 | } |
692 | |
693 | ext4_free_ext_path(path); |
694 | ext4_double_up_write_data_sem(orig_inode, donor_inode); |
695 | unlock_two_nondirectories(orig_inode, donor_inode); |
696 | |
697 | return ret; |
698 | } |
699 | |