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1// SPDX-License-Identifier: LGPL-2.12/*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 searched19 * @lblock: logical block number to find an extent path20 * @path: pointer to an extent path21 *22 * ext4_find_extent wrapper. Return an extent path pointer on success,23 * or an error pointer on failure.24 */25static inline struct ext4_ext_path *26get_ext_path(struct inode *inode, ext4_lblk_t lblock,27 struct ext4_ext_path *path)28{29 path = ext4_find_extent(inode, lblock, path, EXT4_EX_NOCACHE);30 if (IS_ERR(path))31 return path;32 if (path[ext_depth(inode)].p_ext == NULL) {33 ext4_free_ext_path(path);34 return ERR_PTR(-ENODATA);35 }36 return path;37}38 39/**40 * ext4_double_down_write_data_sem() - write lock two inodes's i_data_sem41 * @first: inode to be locked42 * @second: inode to be locked43 *44 * Acquire write lock of i_data_sem of the two inodes45 */46void47ext4_double_down_write_data_sem(struct inode *first, struct inode *second)48{49 if (first < second) {50 down_write(&EXT4_I(first)->i_data_sem);51 down_write_nested(&EXT4_I(second)->i_data_sem, I_DATA_SEM_OTHER);52 } else {53 down_write(&EXT4_I(second)->i_data_sem);54 down_write_nested(&EXT4_I(first)->i_data_sem, I_DATA_SEM_OTHER);55 56 }57}58 59/**60 * ext4_double_up_write_data_sem - Release two inodes' write lock of i_data_sem61 *62 * @orig_inode: original inode structure to be released its lock first63 * @donor_inode: donor inode structure to be released its lock second64 * Release write lock of i_data_sem of two inodes (orig and donor).65 */66void67ext4_double_up_write_data_sem(struct inode *orig_inode,68 struct inode *donor_inode)69{70 up_write(&EXT4_I(orig_inode)->i_data_sem);71 up_write(&EXT4_I(donor_inode)->i_data_sem);72}73 74/**75 * mext_check_coverage - Check that all extents in range has the same type76 *77 * @inode: inode in question78 * @from: block offset of inode79 * @count: block count to be checked80 * @unwritten: extents expected to be unwritten81 * @err: pointer to save error value82 *83 * Return 1 if all extents in range has expected type, and zero otherwise.84 */85static int86mext_check_coverage(struct inode *inode, ext4_lblk_t from, ext4_lblk_t count,87 int unwritten, int *err)88{89 struct ext4_ext_path *path = NULL;90 struct ext4_extent *ext;91 int ret = 0;92 ext4_lblk_t last = from + count;93 while (from < last) {94 path = get_ext_path(inode, from, path);95 if (IS_ERR(path)) {96 *err = PTR_ERR(path);97 return ret;98 }99 ext = path[ext_depth(inode)].p_ext;100 if (unwritten != ext4_ext_is_unwritten(ext))101 goto out;102 from += ext4_ext_get_actual_len(ext);103 }104 ret = 1;105out:106 ext4_free_ext_path(path);107 return ret;108}109 110/**111 * mext_folio_double_lock - Grab and lock folio on both @inode1 and @inode2112 *113 * @inode1: the inode structure114 * @inode2: the inode structure115 * @index1: folio index116 * @index2: folio index117 * @folio: result folio vector118 *119 * Grab two locked folio for inode's by inode order120 */121static int122mext_folio_double_lock(struct inode *inode1, struct inode *inode2,123 pgoff_t index1, pgoff_t index2, struct folio *folio[2])124{125 struct address_space *mapping[2];126 unsigned int flags;127 128 BUG_ON(!inode1 || !inode2);129 if (inode1 < inode2) {130 mapping[0] = inode1->i_mapping;131 mapping[1] = inode2->i_mapping;132 } else {133 swap(index1, index2);134 mapping[0] = inode2->i_mapping;135 mapping[1] = inode1->i_mapping;136 }137 138 flags = memalloc_nofs_save();139 folio[0] = __filemap_get_folio(mapping[0], index1, FGP_WRITEBEGIN,140 mapping_gfp_mask(mapping[0]));141 if (IS_ERR(folio[0])) {142 memalloc_nofs_restore(flags);143 return PTR_ERR(folio[0]);144 }145 146 folio[1] = __filemap_get_folio(mapping[1], index2, FGP_WRITEBEGIN,147 mapping_gfp_mask(mapping[1]));148 memalloc_nofs_restore(flags);149 if (IS_ERR(folio[1])) {150 folio_unlock(folio[0]);151 folio_put(folio[0]);152 return PTR_ERR(folio[1]);153 }154 /*155 * __filemap_get_folio() may not wait on folio's writeback if156 * BDI not demand that. But it is reasonable to be very conservative157 * here and explicitly wait on folio's writeback158 */159 folio_wait_writeback(folio[0]);160 folio_wait_writeback(folio[1]);161 if (inode1 > inode2)162 swap(folio[0], folio[1]);163 164 return 0;165}166 167/* Force folio buffers uptodate w/o dropping folio's lock */168static int mext_page_mkuptodate(struct folio *folio, size_t from, size_t to)169{170 struct inode *inode = folio->mapping->host;171 sector_t block;172 struct buffer_head *bh, *head;173 unsigned int blocksize, block_start, block_end;174 int nr = 0;175 bool partial = false;176 177 BUG_ON(!folio_test_locked(folio));178 BUG_ON(folio_test_writeback(folio));179 180 if (folio_test_uptodate(folio))181 return 0;182 183 blocksize = i_blocksize(inode);184 head = folio_buffers(folio);185 if (!head)186 head = create_empty_buffers(folio, blocksize, 0);187 188 block = folio_pos(folio) >> inode->i_blkbits;189 block_end = 0;190 bh = head;191 do {192 block_start = block_end;193 block_end = block_start + blocksize;194 if (block_end <= from || block_start >= to) {195 if (!buffer_uptodate(bh))196 partial = true;197 continue;198 }199 if (buffer_uptodate(bh))200 continue;201 if (!buffer_mapped(bh)) {202 int err = ext4_get_block(inode, block, bh, 0);203 if (err)204 return err;205 if (!buffer_mapped(bh)) {206 folio_zero_range(folio, block_start, blocksize);207 set_buffer_uptodate(bh);208 continue;209 }210 }211 lock_buffer(bh);212 if (buffer_uptodate(bh)) {213 unlock_buffer(bh);214 continue;215 }216 ext4_read_bh_nowait(bh, 0, NULL);217 nr++;218 } while (block++, (bh = bh->b_this_page) != head);219 220 /* No io required */221 if (!nr)222 goto out;223 224 bh = head;225 do {226 if (bh_offset(bh) + blocksize <= from)227 continue;228 if (bh_offset(bh) > to)229 break;230 wait_on_buffer(bh);231 if (buffer_uptodate(bh))232 continue;233 return -EIO;234 } while ((bh = bh->b_this_page) != head);235out:236 if (!partial)237 folio_mark_uptodate(folio);238 return 0;239}240 241/**242 * move_extent_per_page - Move extent data per page243 *244 * @o_filp: file structure of original file245 * @donor_inode: donor inode246 * @orig_page_offset: page index on original file247 * @donor_page_offset: page index on donor file248 * @data_offset_in_page: block index where data swapping starts249 * @block_len_in_page: the number of blocks to be swapped250 * @unwritten: orig extent is unwritten or not251 * @err: pointer to save return value252 *253 * Save the data in original inode blocks and replace original inode extents254 * with donor inode extents by calling ext4_swap_extents().255 * Finally, write out the saved data in new original inode blocks. Return256 * replaced block count.257 */258static int259move_extent_per_page(struct file *o_filp, struct inode *donor_inode,260 pgoff_t orig_page_offset, pgoff_t donor_page_offset,261 int data_offset_in_page,262 int block_len_in_page, int unwritten, int *err)263{264 struct inode *orig_inode = file_inode(o_filp);265 struct folio *folio[2] = {NULL, NULL};266 handle_t *handle;267 ext4_lblk_t orig_blk_offset, donor_blk_offset;268 unsigned long blocksize = orig_inode->i_sb->s_blocksize;269 unsigned int tmp_data_size, data_size, replaced_size;270 int i, err2, jblocks, retries = 0;271 int replaced_count = 0;272 int from = data_offset_in_page << orig_inode->i_blkbits;273 int blocks_per_page = PAGE_SIZE >> orig_inode->i_blkbits;274 struct super_block *sb = orig_inode->i_sb;275 struct buffer_head *bh = NULL;276 277 /*278 * It needs twice the amount of ordinary journal buffers because279 * inode and donor_inode may change each different metadata blocks.280 */281again:282 *err = 0;283 jblocks = ext4_writepage_trans_blocks(orig_inode) * 2;284 handle = ext4_journal_start(orig_inode, EXT4_HT_MOVE_EXTENTS, jblocks);285 if (IS_ERR(handle)) {286 *err = PTR_ERR(handle);287 return 0;288 }289 290 orig_blk_offset = orig_page_offset * blocks_per_page +291 data_offset_in_page;292 293 donor_blk_offset = donor_page_offset * blocks_per_page +294 data_offset_in_page;295 296 /* Calculate data_size */297 if ((orig_blk_offset + block_len_in_page - 1) ==298 ((orig_inode->i_size - 1) >> orig_inode->i_blkbits)) {299 /* Replace the last block */300 tmp_data_size = orig_inode->i_size & (blocksize - 1);301 /*302 * If data_size equal zero, it shows data_size is multiples of303 * blocksize. So we set appropriate value.304 */305 if (tmp_data_size == 0)306 tmp_data_size = blocksize;307 308 data_size = tmp_data_size +309 ((block_len_in_page - 1) << orig_inode->i_blkbits);310 } else311 data_size = block_len_in_page << orig_inode->i_blkbits;312 313 replaced_size = data_size;314 315 *err = mext_folio_double_lock(orig_inode, donor_inode, orig_page_offset,316 donor_page_offset, folio);317 if (unlikely(*err < 0))318 goto stop_journal;319 /*320 * If orig extent was unwritten it can become initialized321 * at any time after i_data_sem was dropped, in order to322 * serialize with delalloc we have recheck extent while we323 * hold page's lock, if it is still the case data copy is not324 * necessary, just swap data blocks between orig and donor.325 */326 327 VM_BUG_ON_FOLIO(folio_test_large(folio[0]), folio[0]);328 VM_BUG_ON_FOLIO(folio_test_large(folio[1]), folio[1]);329 VM_BUG_ON_FOLIO(folio_nr_pages(folio[0]) != folio_nr_pages(folio[1]), folio[1]);330 331 if (unwritten) {332 ext4_double_down_write_data_sem(orig_inode, donor_inode);333 /* If any of extents in range became initialized we have to334 * fallback to data copying */335 unwritten = mext_check_coverage(orig_inode, orig_blk_offset,336 block_len_in_page, 1, err);337 if (*err)338 goto drop_data_sem;339 340 unwritten &= mext_check_coverage(donor_inode, donor_blk_offset,341 block_len_in_page, 1, err);342 if (*err)343 goto drop_data_sem;344 345 if (!unwritten) {346 ext4_double_up_write_data_sem(orig_inode, donor_inode);347 goto data_copy;348 }349 if (!filemap_release_folio(folio[0], 0) ||350 !filemap_release_folio(folio[1], 0)) {351 *err = -EBUSY;352 goto drop_data_sem;353 }354 replaced_count = ext4_swap_extents(handle, orig_inode,355 donor_inode, orig_blk_offset,356 donor_blk_offset,357 block_len_in_page, 1, err);358 drop_data_sem:359 ext4_double_up_write_data_sem(orig_inode, donor_inode);360 goto unlock_folios;361 }362data_copy:363 *err = mext_page_mkuptodate(folio[0], from, from + replaced_size);364 if (*err)365 goto unlock_folios;366 367 /* At this point all buffers in range are uptodate, old mapping layout368 * is no longer required, try to drop it now. */369 if (!filemap_release_folio(folio[0], 0) ||370 !filemap_release_folio(folio[1], 0)) {371 *err = -EBUSY;372 goto unlock_folios;373 }374 ext4_double_down_write_data_sem(orig_inode, donor_inode);375 replaced_count = ext4_swap_extents(handle, orig_inode, donor_inode,376 orig_blk_offset, donor_blk_offset,377 block_len_in_page, 1, err);378 ext4_double_up_write_data_sem(orig_inode, donor_inode);379 if (*err) {380 if (replaced_count) {381 block_len_in_page = replaced_count;382 replaced_size =383 block_len_in_page << orig_inode->i_blkbits;384 } else385 goto unlock_folios;386 }387 /* Perform all necessary steps similar write_begin()/write_end()388 * but keeping in mind that i_size will not change */389 bh = folio_buffers(folio[0]);390 if (!bh)391 bh = create_empty_buffers(folio[0],392 1 << orig_inode->i_blkbits, 0);393 for (i = 0; i < data_offset_in_page; i++)394 bh = bh->b_this_page;395 for (i = 0; i < block_len_in_page; i++) {396 *err = ext4_get_block(orig_inode, orig_blk_offset + i, bh, 0);397 if (*err < 0)398 goto repair_branches;399 bh = bh->b_this_page;400 }401 402 block_commit_write(&folio[0]->page, from, from + replaced_size);403 404 /* Even in case of data=writeback it is reasonable to pin405 * inode to transaction, to prevent unexpected data loss */406 *err = ext4_jbd2_inode_add_write(handle, orig_inode,407 (loff_t)orig_page_offset << PAGE_SHIFT, replaced_size);408 409unlock_folios:410 folio_unlock(folio[0]);411 folio_put(folio[0]);412 folio_unlock(folio[1]);413 folio_put(folio[1]);414stop_journal:415 ext4_journal_stop(handle);416 if (*err == -ENOSPC &&417 ext4_should_retry_alloc(sb, &retries))418 goto again;419 /* Buffer was busy because probably is pinned to journal transaction,420 * force transaction commit may help to free it. */421 if (*err == -EBUSY && retries++ < 4 && EXT4_SB(sb)->s_journal &&422 jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal))423 goto again;424 return replaced_count;425 426repair_branches:427 /*428 * This should never ever happen!429 * Extents are swapped already, but we are not able to copy data.430 * Try to swap extents to it's original places431 */432 ext4_double_down_write_data_sem(orig_inode, donor_inode);433 replaced_count = ext4_swap_extents(handle, donor_inode, orig_inode,434 orig_blk_offset, donor_blk_offset,435 block_len_in_page, 0, &err2);436 ext4_double_up_write_data_sem(orig_inode, donor_inode);437 if (replaced_count != block_len_in_page) {438 ext4_error_inode_block(orig_inode, (sector_t)(orig_blk_offset),439 EIO, "Unable to copy data block,"440 " data will be lost.");441 *err = -EIO;442 }443 replaced_count = 0;444 goto unlock_folios;445}446 447/**448 * mext_check_arguments - Check whether move extent can be done449 *450 * @orig_inode: original inode451 * @donor_inode: donor inode452 * @orig_start: logical start offset in block for orig453 * @donor_start: logical start offset in block for donor454 * @len: the number of blocks to be moved455 *456 * Check the arguments of ext4_move_extents() whether the files can be457 * exchanged with each other.458 * Return 0 on success, or a negative error value on failure.459 */460static int461mext_check_arguments(struct inode *orig_inode,462 struct inode *donor_inode, __u64 orig_start,463 __u64 donor_start, __u64 *len)464{465 __u64 orig_eof, donor_eof;466 unsigned int blkbits = orig_inode->i_blkbits;467 unsigned int blocksize = 1 << blkbits;468 469 orig_eof = (i_size_read(orig_inode) + blocksize - 1) >> blkbits;470 donor_eof = (i_size_read(donor_inode) + blocksize - 1) >> blkbits;471 472 473 if (donor_inode->i_mode & (S_ISUID|S_ISGID)) {474 ext4_debug("ext4 move extent: suid or sgid is set"475 " to donor file [ino:orig %lu, donor %lu]\n",476 orig_inode->i_ino, donor_inode->i_ino);477 return -EINVAL;478 }479 480 if (IS_IMMUTABLE(donor_inode) || IS_APPEND(donor_inode))481 return -EPERM;482 483 /* Ext4 move extent does not support swap files */484 if (IS_SWAPFILE(orig_inode) || IS_SWAPFILE(donor_inode)) {485 ext4_debug("ext4 move extent: The argument files should not be swap files [ino:orig %lu, donor %lu]\n",486 orig_inode->i_ino, donor_inode->i_ino);487 return -ETXTBSY;488 }489 490 if (ext4_is_quota_file(orig_inode) && ext4_is_quota_file(donor_inode)) {491 ext4_debug("ext4 move extent: The argument files should not be quota files [ino:orig %lu, donor %lu]\n",492 orig_inode->i_ino, donor_inode->i_ino);493 return -EOPNOTSUPP;494 }495 496 /* Ext4 move extent supports only extent based file */497 if (!(ext4_test_inode_flag(orig_inode, EXT4_INODE_EXTENTS))) {498 ext4_debug("ext4 move extent: orig file is not extents "499 "based file [ino:orig %lu]\n", orig_inode->i_ino);500 return -EOPNOTSUPP;501 } else if (!(ext4_test_inode_flag(donor_inode, EXT4_INODE_EXTENTS))) {502 ext4_debug("ext4 move extent: donor file is not extents "503 "based file [ino:donor %lu]\n", donor_inode->i_ino);504 return -EOPNOTSUPP;505 }506 507 if ((!orig_inode->i_size) || (!donor_inode->i_size)) {508 ext4_debug("ext4 move extent: File size is 0 byte\n");509 return -EINVAL;510 }511 512 /* Start offset should be same */513 if ((orig_start & ~(PAGE_MASK >> orig_inode->i_blkbits)) !=514 (donor_start & ~(PAGE_MASK >> orig_inode->i_blkbits))) {515 ext4_debug("ext4 move extent: orig and donor's start "516 "offsets are not aligned [ino:orig %lu, donor %lu]\n",517 orig_inode->i_ino, donor_inode->i_ino);518 return -EINVAL;519 }520 521 if ((orig_start >= EXT_MAX_BLOCKS) ||522 (donor_start >= EXT_MAX_BLOCKS) ||523 (*len > EXT_MAX_BLOCKS) ||524 (donor_start + *len >= EXT_MAX_BLOCKS) ||525 (orig_start + *len >= EXT_MAX_BLOCKS)) {526 ext4_debug("ext4 move extent: Can't handle over [%u] blocks "527 "[ino:orig %lu, donor %lu]\n", EXT_MAX_BLOCKS,528 orig_inode->i_ino, donor_inode->i_ino);529 return -EINVAL;530 }531 if (orig_eof <= orig_start)532 *len = 0;533 else if (orig_eof < orig_start + *len - 1)534 *len = orig_eof - orig_start;535 if (donor_eof <= donor_start)536 *len = 0;537 else if (donor_eof < donor_start + *len - 1)538 *len = donor_eof - donor_start;539 if (!*len) {540 ext4_debug("ext4 move extent: len should not be 0 "541 "[ino:orig %lu, donor %lu]\n", orig_inode->i_ino,542 donor_inode->i_ino);543 return -EINVAL;544 }545 546 return 0;547}548 549/**550 * ext4_move_extents - Exchange the specified range of a file551 *552 * @o_filp: file structure of the original file553 * @d_filp: file structure of the donor file554 * @orig_blk: start offset in block for orig555 * @donor_blk: start offset in block for donor556 * @len: the number of blocks to be moved557 * @moved_len: moved block length558 *559 * This function returns 0 and moved block length is set in moved_len560 * if succeed, otherwise returns error value.561 *562 */563int564ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk,565 __u64 donor_blk, __u64 len, __u64 *moved_len)566{567 struct inode *orig_inode = file_inode(o_filp);568 struct inode *donor_inode = file_inode(d_filp);569 struct ext4_ext_path *path = NULL;570 int blocks_per_page = PAGE_SIZE >> orig_inode->i_blkbits;571 ext4_lblk_t o_end, o_start = orig_blk;572 ext4_lblk_t d_start = donor_blk;573 int ret;574 575 if (orig_inode->i_sb != donor_inode->i_sb) {576 ext4_debug("ext4 move extent: The argument files "577 "should be in same FS [ino:orig %lu, donor %lu]\n",578 orig_inode->i_ino, donor_inode->i_ino);579 return -EINVAL;580 }581 582 /* orig and donor should be different inodes */583 if (orig_inode == donor_inode) {584 ext4_debug("ext4 move extent: The argument files should not "585 "be same inode [ino:orig %lu, donor %lu]\n",586 orig_inode->i_ino, donor_inode->i_ino);587 return -EINVAL;588 }589 590 /* Regular file check */591 if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) {592 ext4_debug("ext4 move extent: The argument files should be "593 "regular file [ino:orig %lu, donor %lu]\n",594 orig_inode->i_ino, donor_inode->i_ino);595 return -EINVAL;596 }597 598 /* TODO: it's not obvious how to swap blocks for inodes with full599 journaling enabled */600 if (ext4_should_journal_data(orig_inode) ||601 ext4_should_journal_data(donor_inode)) {602 ext4_msg(orig_inode->i_sb, KERN_ERR,603 "Online defrag not supported with data journaling");604 return -EOPNOTSUPP;605 }606 607 if (IS_ENCRYPTED(orig_inode) || IS_ENCRYPTED(donor_inode)) {608 ext4_msg(orig_inode->i_sb, KERN_ERR,609 "Online defrag not supported for encrypted files");610 return -EOPNOTSUPP;611 }612 613 /* Protect orig and donor inodes against a truncate */614 lock_two_nondirectories(orig_inode, donor_inode);615 616 /* Wait for all existing dio workers */617 inode_dio_wait(orig_inode);618 inode_dio_wait(donor_inode);619 620 /* Protect extent tree against block allocations via delalloc */621 ext4_double_down_write_data_sem(orig_inode, donor_inode);622 /* Check the filesystem environment whether move_extent can be done */623 ret = mext_check_arguments(orig_inode, donor_inode, orig_blk,624 donor_blk, &len);625 if (ret)626 goto out;627 o_end = o_start + len;628 629 *moved_len = 0;630 while (o_start < o_end) {631 struct ext4_extent *ex;632 ext4_lblk_t cur_blk, next_blk;633 pgoff_t orig_page_index, donor_page_index;634 int offset_in_page;635 int unwritten, cur_len;636 637 path = get_ext_path(orig_inode, o_start, path);638 if (IS_ERR(path)) {639 ret = PTR_ERR(path);640 goto out;641 }642 ex = path[path->p_depth].p_ext;643 cur_blk = le32_to_cpu(ex->ee_block);644 cur_len = ext4_ext_get_actual_len(ex);645 /* Check hole before the start pos */646 if (cur_blk + cur_len - 1 < o_start) {647 next_blk = ext4_ext_next_allocated_block(path);648 if (next_blk == EXT_MAX_BLOCKS) {649 ret = -ENODATA;650 goto out;651 }652 d_start += next_blk - o_start;653 o_start = next_blk;654 continue;655 /* Check hole after the start pos */656 } else if (cur_blk > o_start) {657 /* Skip hole */658 d_start += cur_blk - o_start;659 o_start = cur_blk;660 /* Extent inside requested range ?*/661 if (cur_blk >= o_end)662 goto out;663 } else { /* in_range(o_start, o_blk, o_len) */664 cur_len += cur_blk - o_start;665 }666 unwritten = ext4_ext_is_unwritten(ex);667 if (o_end - o_start < cur_len)668 cur_len = o_end - o_start;669 670 orig_page_index = o_start >> (PAGE_SHIFT -671 orig_inode->i_blkbits);672 donor_page_index = d_start >> (PAGE_SHIFT -673 donor_inode->i_blkbits);674 offset_in_page = o_start % blocks_per_page;675 if (cur_len > blocks_per_page - offset_in_page)676 cur_len = blocks_per_page - offset_in_page;677 /*678 * Up semaphore to avoid following problems:679 * a. transaction deadlock among ext4_journal_start,680 * ->write_begin via pagefault, and jbd2_journal_commit681 * b. racing with ->read_folio, ->write_begin, and682 * ext4_get_block in move_extent_per_page683 */684 ext4_double_up_write_data_sem(orig_inode, donor_inode);685 /* Swap original branches with new branches */686 *moved_len += move_extent_per_page(o_filp, donor_inode,687 orig_page_index, donor_page_index,688 offset_in_page, cur_len,689 unwritten, &ret);690 ext4_double_down_write_data_sem(orig_inode, donor_inode);691 if (ret < 0)692 break;693 o_start += cur_len;694 d_start += cur_len;695 }696 697out:698 if (*moved_len) {699 ext4_discard_preallocations(orig_inode);700 ext4_discard_preallocations(donor_inode);701 }702 703 ext4_free_ext_path(path);704 ext4_double_up_write_data_sem(orig_inode, donor_inode);705 unlock_two_nondirectories(orig_inode, donor_inode);706 707 return ret;708}709