1 // SPDX-License-Identifier: LGPL-2.1
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>
9 #include <linux/quotaops.h>
10 #include <linux/slab.h>
11 #include <linux/sched/mm.h>
12 #include "ext4_jbd2.h"
14 #include "ext4_extents.h"
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)
22 * ext4_find_extent wrapper. Return 0 on success, or a negative error value
26 get_ext_path(struct inode *inode, ext4_lblk_t lblock,
27 struct ext4_ext_path **ppath)
29 struct ext4_ext_path *path;
31 path = ext4_find_extent(inode, lblock, ppath, EXT4_EX_NOCACHE);
34 if (path[ext_depth(inode)].p_ext == NULL) {
35 ext4_free_ext_path(path);
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
48 * Acquire write lock of i_data_sem of the two inodes
51 ext4_double_down_write_data_sem(struct inode *first, struct inode *second)
54 down_write(&EXT4_I(first)->i_data_sem);
55 down_write_nested(&EXT4_I(second)->i_data_sem, I_DATA_SEM_OTHER);
57 down_write(&EXT4_I(second)->i_data_sem);
58 down_write_nested(&EXT4_I(first)->i_data_sem, I_DATA_SEM_OTHER);
64 * ext4_double_up_write_data_sem - Release two inodes' write lock of i_data_sem
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).
71 ext4_double_up_write_data_sem(struct inode *orig_inode,
72 struct inode *donor_inode)
74 up_write(&EXT4_I(orig_inode)->i_data_sem);
75 up_write(&EXT4_I(donor_inode)->i_data_sem);
79 * mext_check_coverage - Check that all extents in range has the same type
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
87 * Return 1 if all extents in range has expected type, and zero otherwise.
90 mext_check_coverage(struct inode *inode, ext4_lblk_t from, ext4_lblk_t count,
91 int unwritten, int *err)
93 struct ext4_ext_path *path = NULL;
94 struct ext4_extent *ext;
96 ext4_lblk_t last = from + count;
98 *err = get_ext_path(inode, from, &path);
101 ext = path[ext_depth(inode)].p_ext;
102 if (unwritten != ext4_ext_is_unwritten(ext))
104 from += ext4_ext_get_actual_len(ext);
108 ext4_free_ext_path(path);
113 * mext_folio_double_lock - Grab and lock folio on both @inode1 and @inode2
115 * @inode1: the inode structure
116 * @inode2: the inode structure
117 * @index1: folio index
118 * @index2: folio index
119 * @folio: result folio vector
121 * Grab two locked folio for inode's by inode order
124 mext_folio_double_lock(struct inode *inode1, struct inode *inode2,
125 pgoff_t index1, pgoff_t index2, struct folio *folio[2])
127 struct address_space *mapping[2];
130 BUG_ON(!inode1 || !inode2);
131 if (inode1 < inode2) {
132 mapping[0] = inode1->i_mapping;
133 mapping[1] = inode2->i_mapping;
135 swap(index1, index2);
136 mapping[0] = inode2->i_mapping;
137 mapping[1] = inode1->i_mapping;
140 flags = memalloc_nofs_save();
141 folio[0] = __filemap_get_folio(mapping[0], index1, FGP_WRITEBEGIN,
142 mapping_gfp_mask(mapping[0]));
143 if (IS_ERR(folio[0])) {
144 memalloc_nofs_restore(flags);
145 return PTR_ERR(folio[0]);
148 folio[1] = __filemap_get_folio(mapping[1], index2, FGP_WRITEBEGIN,
149 mapping_gfp_mask(mapping[1]));
150 memalloc_nofs_restore(flags);
151 if (IS_ERR(folio[1])) {
152 folio_unlock(folio[0]);
154 return PTR_ERR(folio[1]);
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
161 folio_wait_writeback(folio[0]);
162 folio_wait_writeback(folio[1]);
164 swap(folio[0], folio[1]);
169 /* Force page buffers uptodate w/o dropping page's lock */
171 mext_page_mkuptodate(struct folio *folio, unsigned from, unsigned to)
173 struct inode *inode = folio->mapping->host;
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));
181 if (folio_test_uptodate(folio))
184 blocksize = i_blocksize(inode);
185 head = folio_buffers(folio);
187 create_empty_buffers(&folio->page, blocksize, 0);
188 head = folio_buffers(folio);
191 block = (sector_t)folio->index << (PAGE_SHIFT - inode->i_blkbits);
192 for (bh = head, block_start = 0; bh != head || !block_start;
193 block++, block_start = block_end, bh = bh->b_this_page) {
194 block_end = block_start + blocksize;
195 if (block_end <= from || block_start >= to) {
196 if (!buffer_uptodate(bh))
200 if (buffer_uptodate(bh))
202 if (!buffer_mapped(bh)) {
203 err = ext4_get_block(inode, block, bh, 0);
205 folio_set_error(folio);
208 if (!buffer_mapped(bh)) {
209 folio_zero_range(folio, block_start, blocksize);
210 set_buffer_uptodate(bh);
214 BUG_ON(nr >= MAX_BUF_PER_PAGE);
221 for (i = 0; i < nr; i++) {
223 if (!bh_uptodate_or_lock(bh)) {
224 err = ext4_read_bh(bh, 0, NULL);
231 folio_mark_uptodate(folio);
236 * move_extent_per_page - Move extent data per page
238 * @o_filp: file structure of original file
239 * @donor_inode: donor inode
240 * @orig_page_offset: page index on original file
241 * @donor_page_offset: page index on donor file
242 * @data_offset_in_page: block index where data swapping starts
243 * @block_len_in_page: the number of blocks to be swapped
244 * @unwritten: orig extent is unwritten or not
245 * @err: pointer to save return value
247 * Save the data in original inode blocks and replace original inode extents
248 * with donor inode extents by calling ext4_swap_extents().
249 * Finally, write out the saved data in new original inode blocks. Return
250 * replaced block count.
253 move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
254 pgoff_t orig_page_offset, pgoff_t donor_page_offset,
255 int data_offset_in_page,
256 int block_len_in_page, int unwritten, int *err)
258 struct inode *orig_inode = file_inode(o_filp);
259 struct folio *folio[2] = {NULL, NULL};
261 ext4_lblk_t orig_blk_offset, donor_blk_offset;
262 unsigned long blocksize = orig_inode->i_sb->s_blocksize;
263 unsigned int tmp_data_size, data_size, replaced_size;
264 int i, err2, jblocks, retries = 0;
265 int replaced_count = 0;
266 int from = data_offset_in_page << orig_inode->i_blkbits;
267 int blocks_per_page = PAGE_SIZE >> orig_inode->i_blkbits;
268 struct super_block *sb = orig_inode->i_sb;
269 struct buffer_head *bh = NULL;
272 * It needs twice the amount of ordinary journal buffers because
273 * inode and donor_inode may change each different metadata blocks.
277 jblocks = ext4_writepage_trans_blocks(orig_inode) * 2;
278 handle = ext4_journal_start(orig_inode, EXT4_HT_MOVE_EXTENTS, jblocks);
279 if (IS_ERR(handle)) {
280 *err = PTR_ERR(handle);
284 orig_blk_offset = orig_page_offset * blocks_per_page +
287 donor_blk_offset = donor_page_offset * blocks_per_page +
290 /* Calculate data_size */
291 if ((orig_blk_offset + block_len_in_page - 1) ==
292 ((orig_inode->i_size - 1) >> orig_inode->i_blkbits)) {
293 /* Replace the last block */
294 tmp_data_size = orig_inode->i_size & (blocksize - 1);
296 * If data_size equal zero, it shows data_size is multiples of
297 * blocksize. So we set appropriate value.
299 if (tmp_data_size == 0)
300 tmp_data_size = blocksize;
302 data_size = tmp_data_size +
303 ((block_len_in_page - 1) << orig_inode->i_blkbits);
305 data_size = block_len_in_page << orig_inode->i_blkbits;
307 replaced_size = data_size;
309 *err = mext_folio_double_lock(orig_inode, donor_inode, orig_page_offset,
310 donor_page_offset, folio);
311 if (unlikely(*err < 0))
314 * If orig extent was unwritten it can become initialized
315 * at any time after i_data_sem was dropped, in order to
316 * serialize with delalloc we have recheck extent while we
317 * hold page's lock, if it is still the case data copy is not
318 * necessary, just swap data blocks between orig and donor.
321 VM_BUG_ON_FOLIO(folio_test_large(folio[0]), folio[0]);
322 VM_BUG_ON_FOLIO(folio_test_large(folio[1]), folio[1]);
323 VM_BUG_ON_FOLIO(folio_nr_pages(folio[0]) != folio_nr_pages(folio[1]), folio[1]);
326 ext4_double_down_write_data_sem(orig_inode, donor_inode);
327 /* If any of extents in range became initialized we have to
328 * fallback to data copying */
329 unwritten = mext_check_coverage(orig_inode, orig_blk_offset,
330 block_len_in_page, 1, err);
334 unwritten &= mext_check_coverage(donor_inode, donor_blk_offset,
335 block_len_in_page, 1, err);
340 ext4_double_up_write_data_sem(orig_inode, donor_inode);
343 if (!filemap_release_folio(folio[0], 0) ||
344 !filemap_release_folio(folio[1], 0)) {
348 replaced_count = ext4_swap_extents(handle, orig_inode,
349 donor_inode, orig_blk_offset,
351 block_len_in_page, 1, err);
353 ext4_double_up_write_data_sem(orig_inode, donor_inode);
357 *err = mext_page_mkuptodate(folio[0], from, from + replaced_size);
361 /* At this point all buffers in range are uptodate, old mapping layout
362 * is no longer required, try to drop it now. */
363 if (!filemap_release_folio(folio[0], 0) ||
364 !filemap_release_folio(folio[1], 0)) {
368 ext4_double_down_write_data_sem(orig_inode, donor_inode);
369 replaced_count = ext4_swap_extents(handle, orig_inode, donor_inode,
370 orig_blk_offset, donor_blk_offset,
371 block_len_in_page, 1, err);
372 ext4_double_up_write_data_sem(orig_inode, donor_inode);
374 if (replaced_count) {
375 block_len_in_page = replaced_count;
377 block_len_in_page << orig_inode->i_blkbits;
381 /* Perform all necessary steps similar write_begin()/write_end()
382 * but keeping in mind that i_size will not change */
383 if (!folio_buffers(folio[0]))
384 create_empty_buffers(&folio[0]->page, 1 << orig_inode->i_blkbits, 0);
385 bh = folio_buffers(folio[0]);
386 for (i = 0; i < data_offset_in_page; i++)
387 bh = bh->b_this_page;
388 for (i = 0; i < block_len_in_page; i++) {
389 *err = ext4_get_block(orig_inode, orig_blk_offset + i, bh, 0);
391 goto repair_branches;
392 bh = bh->b_this_page;
395 block_commit_write(&folio[0]->page, from, from + replaced_size);
397 /* Even in case of data=writeback it is reasonable to pin
398 * inode to transaction, to prevent unexpected data loss */
399 *err = ext4_jbd2_inode_add_write(handle, orig_inode,
400 (loff_t)orig_page_offset << PAGE_SHIFT, replaced_size);
403 folio_unlock(folio[0]);
405 folio_unlock(folio[1]);
408 ext4_journal_stop(handle);
409 if (*err == -ENOSPC &&
410 ext4_should_retry_alloc(sb, &retries))
412 /* Buffer was busy because probably is pinned to journal transaction,
413 * force transaction commit may help to free it. */
414 if (*err == -EBUSY && retries++ < 4 && EXT4_SB(sb)->s_journal &&
415 jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal))
417 return replaced_count;
421 * This should never ever happen!
422 * Extents are swapped already, but we are not able to copy data.
423 * Try to swap extents to it's original places
425 ext4_double_down_write_data_sem(orig_inode, donor_inode);
426 replaced_count = ext4_swap_extents(handle, donor_inode, orig_inode,
427 orig_blk_offset, donor_blk_offset,
428 block_len_in_page, 0, &err2);
429 ext4_double_up_write_data_sem(orig_inode, donor_inode);
430 if (replaced_count != block_len_in_page) {
431 ext4_error_inode_block(orig_inode, (sector_t)(orig_blk_offset),
432 EIO, "Unable to copy data block,"
433 " data will be lost.");
441 * mext_check_arguments - Check whether move extent can be done
443 * @orig_inode: original inode
444 * @donor_inode: donor inode
445 * @orig_start: logical start offset in block for orig
446 * @donor_start: logical start offset in block for donor
447 * @len: the number of blocks to be moved
449 * Check the arguments of ext4_move_extents() whether the files can be
450 * exchanged with each other.
451 * Return 0 on success, or a negative error value on failure.
454 mext_check_arguments(struct inode *orig_inode,
455 struct inode *donor_inode, __u64 orig_start,
456 __u64 donor_start, __u64 *len)
458 __u64 orig_eof, donor_eof;
459 unsigned int blkbits = orig_inode->i_blkbits;
460 unsigned int blocksize = 1 << blkbits;
462 orig_eof = (i_size_read(orig_inode) + blocksize - 1) >> blkbits;
463 donor_eof = (i_size_read(donor_inode) + blocksize - 1) >> blkbits;
466 if (donor_inode->i_mode & (S_ISUID|S_ISGID)) {
467 ext4_debug("ext4 move extent: suid or sgid is set"
468 " to donor file [ino:orig %lu, donor %lu]\n",
469 orig_inode->i_ino, donor_inode->i_ino);
473 if (IS_IMMUTABLE(donor_inode) || IS_APPEND(donor_inode))
476 /* Ext4 move extent does not support swap files */
477 if (IS_SWAPFILE(orig_inode) || IS_SWAPFILE(donor_inode)) {
478 ext4_debug("ext4 move extent: The argument files should not be swap files [ino:orig %lu, donor %lu]\n",
479 orig_inode->i_ino, donor_inode->i_ino);
483 if (ext4_is_quota_file(orig_inode) && ext4_is_quota_file(donor_inode)) {
484 ext4_debug("ext4 move extent: The argument files should not be quota files [ino:orig %lu, donor %lu]\n",
485 orig_inode->i_ino, donor_inode->i_ino);
489 /* Ext4 move extent supports only extent based file */
490 if (!(ext4_test_inode_flag(orig_inode, EXT4_INODE_EXTENTS))) {
491 ext4_debug("ext4 move extent: orig file is not extents "
492 "based file [ino:orig %lu]\n", orig_inode->i_ino);
494 } else if (!(ext4_test_inode_flag(donor_inode, EXT4_INODE_EXTENTS))) {
495 ext4_debug("ext4 move extent: donor file is not extents "
496 "based file [ino:donor %lu]\n", donor_inode->i_ino);
500 if ((!orig_inode->i_size) || (!donor_inode->i_size)) {
501 ext4_debug("ext4 move extent: File size is 0 byte\n");
505 /* Start offset should be same */
506 if ((orig_start & ~(PAGE_MASK >> orig_inode->i_blkbits)) !=
507 (donor_start & ~(PAGE_MASK >> orig_inode->i_blkbits))) {
508 ext4_debug("ext4 move extent: orig and donor's start "
509 "offsets are not aligned [ino:orig %lu, donor %lu]\n",
510 orig_inode->i_ino, donor_inode->i_ino);
514 if ((orig_start >= EXT_MAX_BLOCKS) ||
515 (donor_start >= EXT_MAX_BLOCKS) ||
516 (*len > EXT_MAX_BLOCKS) ||
517 (donor_start + *len >= EXT_MAX_BLOCKS) ||
518 (orig_start + *len >= EXT_MAX_BLOCKS)) {
519 ext4_debug("ext4 move extent: Can't handle over [%u] blocks "
520 "[ino:orig %lu, donor %lu]\n", EXT_MAX_BLOCKS,
521 orig_inode->i_ino, donor_inode->i_ino);
524 if (orig_eof <= orig_start)
526 else if (orig_eof < orig_start + *len - 1)
527 *len = orig_eof - orig_start;
528 if (donor_eof <= donor_start)
530 else if (donor_eof < donor_start + *len - 1)
531 *len = donor_eof - donor_start;
533 ext4_debug("ext4 move extent: len should not be 0 "
534 "[ino:orig %lu, donor %lu]\n", orig_inode->i_ino,
543 * ext4_move_extents - Exchange the specified range of a file
545 * @o_filp: file structure of the original file
546 * @d_filp: file structure of the donor file
547 * @orig_blk: start offset in block for orig
548 * @donor_blk: start offset in block for donor
549 * @len: the number of blocks to be moved
550 * @moved_len: moved block length
552 * This function returns 0 and moved block length is set in moved_len
553 * if succeed, otherwise returns error value.
557 ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk,
558 __u64 donor_blk, __u64 len, __u64 *moved_len)
560 struct inode *orig_inode = file_inode(o_filp);
561 struct inode *donor_inode = file_inode(d_filp);
562 struct ext4_ext_path *path = NULL;
563 int blocks_per_page = PAGE_SIZE >> orig_inode->i_blkbits;
564 ext4_lblk_t o_end, o_start = orig_blk;
565 ext4_lblk_t d_start = donor_blk;
568 if (orig_inode->i_sb != donor_inode->i_sb) {
569 ext4_debug("ext4 move extent: The argument files "
570 "should be in same FS [ino:orig %lu, donor %lu]\n",
571 orig_inode->i_ino, donor_inode->i_ino);
575 /* orig and donor should be different inodes */
576 if (orig_inode == donor_inode) {
577 ext4_debug("ext4 move extent: The argument files should not "
578 "be same inode [ino:orig %lu, donor %lu]\n",
579 orig_inode->i_ino, donor_inode->i_ino);
583 /* Regular file check */
584 if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) {
585 ext4_debug("ext4 move extent: The argument files should be "
586 "regular file [ino:orig %lu, donor %lu]\n",
587 orig_inode->i_ino, donor_inode->i_ino);
591 /* TODO: it's not obvious how to swap blocks for inodes with full
592 journaling enabled */
593 if (ext4_should_journal_data(orig_inode) ||
594 ext4_should_journal_data(donor_inode)) {
595 ext4_msg(orig_inode->i_sb, KERN_ERR,
596 "Online defrag not supported with data journaling");
600 if (IS_ENCRYPTED(orig_inode) || IS_ENCRYPTED(donor_inode)) {
601 ext4_msg(orig_inode->i_sb, KERN_ERR,
602 "Online defrag not supported for encrypted files");
606 /* Protect orig and donor inodes against a truncate */
607 lock_two_nondirectories(orig_inode, donor_inode);
609 /* Wait for all existing dio workers */
610 inode_dio_wait(orig_inode);
611 inode_dio_wait(donor_inode);
613 /* Protect extent tree against block allocations via delalloc */
614 ext4_double_down_write_data_sem(orig_inode, donor_inode);
615 /* Check the filesystem environment whether move_extent can be done */
616 ret = mext_check_arguments(orig_inode, donor_inode, orig_blk,
620 o_end = o_start + len;
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;
627 int unwritten, cur_len;
629 ret = get_ext_path(orig_inode, o_start, &path);
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(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) {
642 d_start += next_blk - o_start;
645 /* Check hole after the start pos */
646 } else if (cur_blk > o_start) {
648 d_start += cur_blk - o_start;
650 /* Extent inside requested range ?*/
651 if (cur_blk >= o_end)
653 } else { /* in_range(o_start, o_blk, o_len) */
654 cur_len += cur_blk - o_start;
656 unwritten = ext4_ext_is_unwritten(ex);
657 if (o_end - o_start < cur_len)
658 cur_len = o_end - o_start;
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;
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
674 ext4_double_up_write_data_sem(orig_inode, donor_inode);
675 /* Swap original branches with new branches */
676 move_extent_per_page(o_filp, donor_inode,
677 orig_page_index, donor_page_index,
678 offset_in_page, cur_len,
680 ext4_double_down_write_data_sem(orig_inode, donor_inode);
686 *moved_len = o_start - orig_blk;
687 if (*moved_len > len)
692 ext4_discard_preallocations(orig_inode, 0);
693 ext4_discard_preallocations(donor_inode, 0);
696 ext4_free_ext_path(path);
697 ext4_double_up_write_data_sem(orig_inode, donor_inode);
698 unlock_two_nondirectories(orig_inode, donor_inode);