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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 : : 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 : : struct ext4_extent *ext;
95 : : 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 : : goto out;
101 : 0 : ext = path[ext_depth(inode)].p_ext;
102 [ # # ]: 0 : if (unwritten != ext4_ext_is_unwritten(ext))
103 : : goto out;
104 : 0 : from += ext4_ext_get_actual_len(ext);
105 : 0 : ext4_ext_drop_refs(path);
106 : : }
107 : : ret = 1;
108 : : 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 : : struct address_space *mapping[2];
130 : : 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 : : 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 : : sector_t block;
171 : : struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
172 : : unsigned int blocksize, block_start, block_end;
173 : : 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 : : 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 : : 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 : : SetPageError(page);
200 : 0 : return err;
201 : : }
202 [ # # ]: 0 : if (!buffer_mapped(bh)) {
203 : : zero_user(page, block_start, blocksize);
204 : : 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 : : 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 = bh_submit_read(bh);
219 [ # # ]: 0 : if (err)
220 : 0 : return err;
221 : : }
222 : : }
223 : : out:
224 [ # # ]: 0 : if (!partial)
225 : : 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 : : struct inode *orig_inode = file_inode(o_filp);
253 : 0 : struct page *pagep[2] = {NULL, NULL};
254 : : handle_t *handle;
255 : : ext4_lblk_t orig_blk_offset, donor_blk_offset;
256 : 0 : unsigned long blocksize = orig_inode->i_sb->s_blocksize;
257 : : unsigned int tmp_data_size, data_size, replaced_size;
258 : 0 : int i, err2, jblocks, retries = 0;
259 : : 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 : : struct super_block *sb = orig_inode->i_sb;
263 : : 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 : : 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 : : 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 : : 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 : : 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 : : 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 : : goto drop_data_sem;
327 : :
328 [ # # ]: 0 : if (!unwritten) {
329 : : ext4_double_up_write_data_sem(orig_inode, donor_inode);
330 : : 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 : : drop_data_sem:
344 : : ext4_double_up_write_data_sem(orig_inode, donor_inode);
345 : : goto unlock_pages;
346 : : }
347 : : data_copy:
348 : 0 : *err = mext_page_mkuptodate(pagep[0], from, from + replaced_size);
349 [ # # ]: 0 : if (*err)
350 : : 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 : : ext4_double_up_write_data_sem(orig_inode, donor_inode);
364 [ # # ]: 0 : if (*err) {
365 [ # # ]: 0 : if (replaced_count) {
366 : : block_len_in_page = replaced_count;
367 : 0 : replaced_size =
368 : 0 : block_len_in_page << orig_inode->i_blkbits;
369 : : } else
370 : : 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 : : 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 : : 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 : : stop_journal:
402 : 0 : ext4_journal_stop(handle);
403 [ # # # # ]: 0 : if (*err == -ENOSPC &&
404 : 0 : ext4_should_retry_alloc(sb, &retries))
405 : : 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 : : goto again;
411 : 0 : return replaced_count;
412 : :
413 : : 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 : : 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 : : "Unable to copy data block,"
427 : : " data will be lost.");
428 : 0 : *err = -EIO;
429 : : }
430 : : replaced_count = 0;
431 : : 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 : : __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 : : 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 : : return -EINVAL;
533 : : }
534 : :
535 : 0 : 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 : : struct inode *orig_inode = file_inode(o_filp);
557 : : 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 : : 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 : : 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 : : goto out;
616 : 0 : o_end = o_start + len;
617 : :
618 [ # # ]: 0 : while (o_start < o_end) {
619 : : struct ext4_extent *ex;
620 : : ext4_lblk_t cur_blk, next_blk;
621 : : pgoff_t orig_page_index, donor_page_index;
622 : : int offset_in_page;
623 : : int unwritten, cur_len;
624 : :
625 : 0 : ret = get_ext_path(orig_inode, o_start, &path);
626 [ # # ]: 0 : if (ret)
627 : : 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 : : 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 : : o_start = o_end;
636 : 0 : ret = -ENODATA;
637 : 0 : goto out;
638 : : }
639 : 0 : d_start += next_blk - o_start;
640 : : 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 : : o_start = cur_blk;
647 : : /* Extent inside requested range ?*/
648 [ # # ]: 0 : if (cur_blk >= o_end)
649 : : goto out;
650 : : } else { /* in_range(o_start, o_blk, o_len) */
651 : 0 : cur_len += cur_blk - o_start;
652 : : }
653 : : 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 : : 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 : : out:
688 [ # # ]: 0 : if (*moved_len) {
689 : 0 : ext4_discard_preallocations(orig_inode);
690 : 0 : ext4_discard_preallocations(donor_inode);
691 : : }
692 : :
693 : 0 : ext4_ext_drop_refs(path);
694 : 0 : kfree(path);
695 : : 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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