2 * Copyright (c) 2008,2009 NEC Software Tohoku, Ltd.
3 * Written by Takashi Sato <t-sato@yk.jp.nec.com>
4 * Akira Fujita <a-fujita@rs.jp.nec.com>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of version 2.1 of the GNU Lesser General Public License
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
17 #include <linux/quotaops.h>
18 #include "ext4_jbd2.h"
19 #include "ext4_extents.h"
23 * get_ext_path - Find an extent path for designated logical block number.
25 * @inode: an inode which is searched
26 * @lblock: logical block number to find an extent path
27 * @path: pointer to an extent path pointer (for output)
29 * ext4_ext_find_extent wrapper. Return 0 on success, or a negative error value
33 get_ext_path(struct inode *inode, ext4_lblk_t lblock,
34 struct ext4_ext_path **path)
38 *path = ext4_ext_find_extent(inode, lblock, *path);
42 } else if ((*path)[ext_depth(inode)].p_ext == NULL)
49 * copy_extent_status - Copy the extent's initialization status
51 * @src: an extent for getting initialize status
52 * @dest: an extent to be set the status
55 copy_extent_status(struct ext4_extent *src, struct ext4_extent *dest)
57 if (ext4_ext_is_uninitialized(src))
58 ext4_ext_mark_uninitialized(dest);
60 dest->ee_len = cpu_to_le16(ext4_ext_get_actual_len(dest));
64 * mext_next_extent - Search for the next extent and set it to "extent"
66 * @inode: inode which is searched
67 * @path: this will obtain data for the next extent
68 * @extent: pointer to the next extent we have just gotten
70 * Search the next extent in the array of ext4_ext_path structure (@path)
71 * and set it to ext4_extent structure (@extent). In addition, the member of
72 * @path (->p_ext) also points the next extent. Return 0 on success, 1 if
73 * ext4_ext_path structure refers to the last extent, or a negative error
77 mext_next_extent(struct inode *inode, struct ext4_ext_path *path,
78 struct ext4_extent **extent)
80 int ppos, leaf_ppos = path->p_depth;
83 if (EXT_LAST_EXTENT(path[ppos].p_hdr) > path[ppos].p_ext) {
85 *extent = ++path[ppos].p_ext;
90 if (EXT_LAST_INDEX(path[ppos].p_hdr) >
96 path[ppos].p_block = idx_pblock(path[ppos].p_idx);
97 if (path[ppos+1].p_bh)
98 brelse(path[ppos+1].p_bh);
100 sb_bread(inode->i_sb, path[ppos].p_block);
101 if (!path[ppos+1].p_bh)
104 ext_block_hdr(path[ppos+1].p_bh);
106 /* Halfway index block */
107 while (++cur_ppos < leaf_ppos) {
108 path[cur_ppos].p_idx =
109 EXT_FIRST_INDEX(path[cur_ppos].p_hdr);
110 path[cur_ppos].p_block =
111 idx_pblock(path[cur_ppos].p_idx);
112 if (path[cur_ppos+1].p_bh)
113 brelse(path[cur_ppos+1].p_bh);
114 path[cur_ppos+1].p_bh = sb_bread(inode->i_sb,
115 path[cur_ppos].p_block);
116 if (!path[cur_ppos+1].p_bh)
118 path[cur_ppos+1].p_hdr =
119 ext_block_hdr(path[cur_ppos+1].p_bh);
123 path[leaf_ppos].p_ext = *extent =
124 EXT_FIRST_EXTENT(path[leaf_ppos].p_hdr);
128 /* We found the last extent */
133 * mext_check_null_inode - NULL check for two inodes
135 * If inode1 or inode2 is NULL, return -EIO. Otherwise, return 0.
138 mext_check_null_inode(struct inode *inode1, struct inode *inode2,
139 const char *function)
143 if (inode1 == NULL) {
144 ext4_error(inode2->i_sb, function,
145 "Both inodes should not be NULL: "
146 "inode1 NULL inode2 %lu", inode2->i_ino);
148 } else if (inode2 == NULL) {
149 ext4_error(inode1->i_sb, function,
150 "Both inodes should not be NULL: "
151 "inode1 %lu inode2 NULL", inode1->i_ino);
158 * mext_double_down_read - Acquire two inodes' read semaphore
160 * @orig_inode: original inode structure
161 * @donor_inode: donor inode structure
162 * Acquire read semaphore of the two inodes (orig and donor) by i_ino order.
165 mext_double_down_read(struct inode *orig_inode, struct inode *donor_inode)
167 struct inode *first = orig_inode, *second = donor_inode;
170 * Use the inode number to provide the stable locking order instead
171 * of its address, because the C language doesn't guarantee you can
172 * compare pointers that don't come from the same array.
174 if (donor_inode->i_ino < orig_inode->i_ino) {
179 down_read(&EXT4_I(first)->i_data_sem);
180 down_read(&EXT4_I(second)->i_data_sem);
184 * mext_double_down_write - Acquire two inodes' write semaphore
186 * @orig_inode: original inode structure
187 * @donor_inode: donor inode structure
188 * Acquire write semaphore of the two inodes (orig and donor) by i_ino order.
191 mext_double_down_write(struct inode *orig_inode, struct inode *donor_inode)
193 struct inode *first = orig_inode, *second = donor_inode;
196 * Use the inode number to provide the stable locking order instead
197 * of its address, because the C language doesn't guarantee you can
198 * compare pointers that don't come from the same array.
200 if (donor_inode->i_ino < orig_inode->i_ino) {
205 down_write(&EXT4_I(first)->i_data_sem);
206 down_write(&EXT4_I(second)->i_data_sem);
210 * mext_double_up_read - Release two inodes' read semaphore
212 * @orig_inode: original inode structure to be released its lock first
213 * @donor_inode: donor inode structure to be released its lock second
214 * Release read semaphore of two inodes (orig and donor).
217 mext_double_up_read(struct inode *orig_inode, struct inode *donor_inode)
219 up_read(&EXT4_I(orig_inode)->i_data_sem);
220 up_read(&EXT4_I(donor_inode)->i_data_sem);
224 * mext_double_up_write - Release two inodes' write semaphore
226 * @orig_inode: original inode structure to be released its lock first
227 * @donor_inode: donor inode structure to be released its lock second
228 * Release write semaphore of two inodes (orig and donor).
231 mext_double_up_write(struct inode *orig_inode, struct inode *donor_inode)
233 up_write(&EXT4_I(orig_inode)->i_data_sem);
234 up_write(&EXT4_I(donor_inode)->i_data_sem);
238 * mext_insert_across_blocks - Insert extents across leaf block
240 * @handle: journal handle
241 * @orig_inode: original inode
242 * @o_start: first original extent to be changed
243 * @o_end: last original extent to be changed
244 * @start_ext: first new extent to be inserted
245 * @new_ext: middle of new extent to be inserted
246 * @end_ext: last new extent to be inserted
248 * Allocate a new leaf block and insert extents into it. Return 0 on success,
249 * or a negative error value on failure.
252 mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode,
253 struct ext4_extent *o_start, struct ext4_extent *o_end,
254 struct ext4_extent *start_ext, struct ext4_extent *new_ext,
255 struct ext4_extent *end_ext)
257 struct ext4_ext_path *orig_path = NULL;
258 ext4_lblk_t eblock = 0;
263 if (start_ext->ee_len && new_ext->ee_len && end_ext->ee_len) {
264 if (o_start == o_end) {
266 /* start_ext new_ext end_ext
267 * donor |---------|-----------|--------|
268 * orig |------------------------------|
273 /* start_ext new_ext end_ext
274 * donor |---------|----------|---------|
275 * orig |---------------|--------------|
277 o_end->ee_block = end_ext->ee_block;
278 o_end->ee_len = end_ext->ee_len;
279 ext4_ext_store_pblock(o_end, ext_pblock(end_ext));
282 o_start->ee_len = start_ext->ee_len;
285 } else if (start_ext->ee_len && new_ext->ee_len &&
286 !end_ext->ee_len && o_start == o_end) {
289 * donor |--------------|---------------|
290 * orig |------------------------------|
292 o_start->ee_len = start_ext->ee_len;
295 } else if (!start_ext->ee_len && new_ext->ee_len &&
296 end_ext->ee_len && o_start == o_end) {
299 * donor |--------------|---------------|
300 * orig |------------------------------|
302 o_end->ee_block = end_ext->ee_block;
303 o_end->ee_len = end_ext->ee_len;
304 ext4_ext_store_pblock(o_end, ext_pblock(end_ext));
307 * Set 0 to the extent block if new_ext was
310 if (new_ext->ee_block)
311 eblock = le32_to_cpu(new_ext->ee_block);
315 ext4_debug("ext4 move extent: Unexpected insert case\n");
320 err = get_ext_path(orig_inode, eblock, &orig_path);
324 if (ext4_ext_insert_extent(handle, orig_inode,
330 err = get_ext_path(orig_inode,
331 le32_to_cpu(end_ext->ee_block) - 1, &orig_path);
335 if (ext4_ext_insert_extent(handle, orig_inode,
341 ext4_ext_drop_refs(orig_path);
350 * mext_insert_inside_block - Insert new extent to the extent block
352 * @o_start: first original extent to be moved
353 * @o_end: last original extent to be moved
354 * @start_ext: first new extent to be inserted
355 * @new_ext: middle of new extent to be inserted
356 * @end_ext: last new extent to be inserted
357 * @eh: extent header of target leaf block
358 * @range_to_move: used to decide how to insert extent
360 * Insert extents into the leaf block. The extent (@o_start) is overwritten
361 * by inserted extents.
364 mext_insert_inside_block(struct ext4_extent *o_start,
365 struct ext4_extent *o_end,
366 struct ext4_extent *start_ext,
367 struct ext4_extent *new_ext,
368 struct ext4_extent *end_ext,
369 struct ext4_extent_header *eh,
375 /* Move the existing extents */
376 if (range_to_move && o_end < EXT_LAST_EXTENT(eh)) {
377 len = (unsigned long)(EXT_LAST_EXTENT(eh) + 1) -
378 (unsigned long)(o_end + 1);
379 memmove(o_end + 1 + range_to_move, o_end + 1, len);
382 /* Insert start entry */
383 if (start_ext->ee_len)
384 o_start[i++].ee_len = start_ext->ee_len;
386 /* Insert new entry */
387 if (new_ext->ee_len) {
388 o_start[i] = *new_ext;
389 ext4_ext_store_pblock(&o_start[i++], ext_pblock(new_ext));
392 /* Insert end entry */
394 o_start[i] = *end_ext;
396 /* Increment the total entries counter on the extent block */
397 le16_add_cpu(&eh->eh_entries, range_to_move);
401 * mext_insert_extents - Insert new extent
403 * @handle: journal handle
404 * @orig_inode: original inode
405 * @orig_path: path indicates first extent to be changed
406 * @o_start: first original extent to be changed
407 * @o_end: last original extent to be changed
408 * @start_ext: first new extent to be inserted
409 * @new_ext: middle of new extent to be inserted
410 * @end_ext: last new extent to be inserted
412 * Call the function to insert extents. If we cannot add more extents into
413 * the leaf block, we call mext_insert_across_blocks() to create a
414 * new leaf block. Otherwise call mext_insert_inside_block(). Return 0
415 * on success, or a negative error value on failure.
418 mext_insert_extents(handle_t *handle, struct inode *orig_inode,
419 struct ext4_ext_path *orig_path,
420 struct ext4_extent *o_start,
421 struct ext4_extent *o_end,
422 struct ext4_extent *start_ext,
423 struct ext4_extent *new_ext,
424 struct ext4_extent *end_ext)
426 struct ext4_extent_header *eh;
427 unsigned long need_slots, slots_range;
428 int range_to_move, depth, ret;
431 * The extents need to be inserted
432 * start_extent + new_extent + end_extent.
434 need_slots = (start_ext->ee_len ? 1 : 0) + (end_ext->ee_len ? 1 : 0) +
435 (new_ext->ee_len ? 1 : 0);
437 /* The number of slots between start and end */
438 slots_range = ((unsigned long)(o_end + 1) - (unsigned long)o_start + 1)
439 / sizeof(struct ext4_extent);
441 /* Range to move the end of extent */
442 range_to_move = need_slots - slots_range;
443 depth = orig_path->p_depth;
445 eh = orig_path->p_hdr;
448 /* Register to journal */
449 ret = ext4_journal_get_write_access(handle, orig_path->p_bh);
455 if (range_to_move > 0 &&
456 (range_to_move > le16_to_cpu(eh->eh_max)
457 - le16_to_cpu(eh->eh_entries))) {
459 ret = mext_insert_across_blocks(handle, orig_inode, o_start,
460 o_end, start_ext, new_ext, end_ext);
464 mext_insert_inside_block(o_start, o_end, start_ext, new_ext,
465 end_ext, eh, range_to_move);
468 ret = ext4_handle_dirty_metadata(handle, orig_inode,
473 ret = ext4_mark_inode_dirty(handle, orig_inode);
482 * mext_leaf_block - Move one leaf extent block into the inode.
484 * @handle: journal handle
485 * @orig_inode: original inode
486 * @orig_path: path indicates first extent to be changed
487 * @dext: donor extent
488 * @from: start offset on the target file
490 * In order to insert extents into the leaf block, we must divide the extent
491 * in the leaf block into three extents. The one is located to be inserted
492 * extents, and the others are located around it.
494 * Therefore, this function creates structures to save extents of the leaf
495 * block, and inserts extents by calling mext_insert_extents() with
496 * created extents. Return 0 on success, or a negative error value on failure.
499 mext_leaf_block(handle_t *handle, struct inode *orig_inode,
500 struct ext4_ext_path *orig_path, struct ext4_extent *dext,
503 struct ext4_extent *oext, *o_start, *o_end, *prev_ext;
504 struct ext4_extent new_ext, start_ext, end_ext;
505 ext4_lblk_t new_ext_end;
506 ext4_fsblk_t new_phys_end;
507 int oext_alen, new_ext_alen, end_ext_alen;
508 int depth = ext_depth(orig_inode);
511 o_start = o_end = oext = orig_path[depth].p_ext;
512 oext_alen = ext4_ext_get_actual_len(oext);
513 start_ext.ee_len = end_ext.ee_len = 0;
515 new_ext.ee_block = cpu_to_le32(*from);
516 ext4_ext_store_pblock(&new_ext, ext_pblock(dext));
517 new_ext.ee_len = dext->ee_len;
518 new_ext_alen = ext4_ext_get_actual_len(&new_ext);
519 new_ext_end = le32_to_cpu(new_ext.ee_block) + new_ext_alen - 1;
520 new_phys_end = ext_pblock(&new_ext) + new_ext_alen - 1;
523 * Case: original extent is first
528 if (le32_to_cpu(oext->ee_block) < le32_to_cpu(new_ext.ee_block) &&
529 le32_to_cpu(new_ext.ee_block) <
530 le32_to_cpu(oext->ee_block) + oext_alen) {
531 start_ext.ee_len = cpu_to_le16(le32_to_cpu(new_ext.ee_block) -
532 le32_to_cpu(oext->ee_block));
533 copy_extent_status(oext, &start_ext);
534 } else if (oext > EXT_FIRST_EXTENT(orig_path[depth].p_hdr)) {
537 * We can merge new_ext into previous extent,
538 * if these are contiguous and same extent type.
540 if (ext4_can_extents_be_merged(orig_inode, prev_ext,
543 start_ext.ee_len = cpu_to_le16(
544 ext4_ext_get_actual_len(prev_ext) +
546 copy_extent_status(prev_ext, &start_ext);
552 * Case: new_ext_end must be less than oext
556 if (le32_to_cpu(oext->ee_block) + oext_alen - 1 < new_ext_end) {
557 ext4_error(orig_inode->i_sb, __func__,
558 "new_ext_end(%u) should be less than or equal to "
559 "oext->ee_block(%u) + oext_alen(%d) - 1",
560 new_ext_end, le32_to_cpu(oext->ee_block),
567 * Case: new_ext is smaller than original extent
568 * oext |---------------|
569 * new_ext |-----------|
572 if (le32_to_cpu(oext->ee_block) <= new_ext_end &&
573 new_ext_end < le32_to_cpu(oext->ee_block) + oext_alen - 1) {
575 cpu_to_le16(le32_to_cpu(oext->ee_block) +
576 oext_alen - 1 - new_ext_end);
577 copy_extent_status(oext, &end_ext);
578 end_ext_alen = ext4_ext_get_actual_len(&end_ext);
579 ext4_ext_store_pblock(&end_ext,
580 (ext_pblock(o_end) + oext_alen - end_ext_alen));
582 cpu_to_le32(le32_to_cpu(o_end->ee_block) +
583 oext_alen - end_ext_alen);
586 ret = mext_insert_extents(handle, orig_inode, orig_path, o_start,
587 o_end, &start_ext, &new_ext, &end_ext);
593 * mext_calc_swap_extents - Calculate extents for extent swapping.
595 * @tmp_dext: the extent that will belong to the original inode
596 * @tmp_oext: the extent that will belong to the donor inode
597 * @orig_off: block offset of original inode
598 * @donor_off: block offset of donor inode
599 * @max_count: the maximun length of extents
602 mext_calc_swap_extents(struct ext4_extent *tmp_dext,
603 struct ext4_extent *tmp_oext,
604 ext4_lblk_t orig_off, ext4_lblk_t donor_off,
605 ext4_lblk_t max_count)
607 ext4_lblk_t diff, orig_diff;
608 struct ext4_extent dext_old, oext_old;
610 dext_old = *tmp_dext;
611 oext_old = *tmp_oext;
613 /* When tmp_dext is too large, pick up the target range. */
614 diff = donor_off - le32_to_cpu(tmp_dext->ee_block);
616 ext4_ext_store_pblock(tmp_dext, ext_pblock(tmp_dext) + diff);
618 cpu_to_le32(le32_to_cpu(tmp_dext->ee_block) + diff);
619 tmp_dext->ee_len = cpu_to_le16(le16_to_cpu(tmp_dext->ee_len) - diff);
621 if (max_count < ext4_ext_get_actual_len(tmp_dext))
622 tmp_dext->ee_len = cpu_to_le16(max_count);
624 orig_diff = orig_off - le32_to_cpu(tmp_oext->ee_block);
625 ext4_ext_store_pblock(tmp_oext, ext_pblock(tmp_oext) + orig_diff);
627 /* Adjust extent length if donor extent is larger than orig */
628 if (ext4_ext_get_actual_len(tmp_dext) >
629 ext4_ext_get_actual_len(tmp_oext) - orig_diff)
630 tmp_dext->ee_len = cpu_to_le16(le16_to_cpu(tmp_oext->ee_len) -
633 tmp_oext->ee_len = cpu_to_le16(ext4_ext_get_actual_len(tmp_dext));
635 copy_extent_status(&oext_old, tmp_dext);
636 copy_extent_status(&dext_old, tmp_oext);
640 * mext_replace_branches - Replace original extents with new extents
642 * @handle: journal handle
643 * @orig_inode: original inode
644 * @donor_inode: donor inode
645 * @from: block offset of orig_inode
646 * @count: block count to be replaced
648 * Replace original inode extents and donor inode extents page by page.
649 * We implement this replacement in the following three steps:
650 * 1. Save the block information of original and donor inodes into
652 * 2. Change the block information of original inode to point at the
653 * donor inode blocks.
654 * 3. Change the block information of donor inode to point at the saved
655 * original inode blocks in the dummy extents.
657 * Return 0 on success, or a negative error value on failure.
660 mext_replace_branches(handle_t *handle, struct inode *orig_inode,
661 struct inode *donor_inode, ext4_lblk_t from,
664 struct ext4_ext_path *orig_path = NULL;
665 struct ext4_ext_path *donor_path = NULL;
666 struct ext4_extent *oext, *dext;
667 struct ext4_extent tmp_dext, tmp_oext;
668 ext4_lblk_t orig_off = from, donor_off = from;
671 int replaced_count = 0;
674 mext_double_down_write(orig_inode, donor_inode);
676 /* Get the original extent for the block "orig_off" */
677 err = get_ext_path(orig_inode, orig_off, &orig_path);
681 /* Get the donor extent for the head */
682 err = get_ext_path(donor_inode, donor_off, &donor_path);
685 depth = ext_depth(orig_inode);
686 oext = orig_path[depth].p_ext;
689 depth = ext_depth(donor_inode);
690 dext = donor_path[depth].p_ext;
693 mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
696 /* Loop for the donor extents */
698 /* The extent for donor must be found. */
700 ext4_error(donor_inode->i_sb, __func__,
701 "The extent for donor must be found");
704 } else if (donor_off != le32_to_cpu(tmp_dext.ee_block)) {
705 ext4_error(donor_inode->i_sb, __func__,
706 "Donor offset(%u) and the first block of donor "
707 "extent(%u) should be equal",
709 le32_to_cpu(tmp_dext.ee_block));
714 /* Set donor extent to orig extent */
715 err = mext_leaf_block(handle, orig_inode,
716 orig_path, &tmp_dext, &orig_off);
720 /* Set orig extent to donor extent */
721 err = mext_leaf_block(handle, donor_inode,
722 donor_path, &tmp_oext, &donor_off);
726 dext_alen = ext4_ext_get_actual_len(&tmp_dext);
727 replaced_count += dext_alen;
728 donor_off += dext_alen;
729 orig_off += dext_alen;
731 /* Already moved the expected blocks */
732 if (replaced_count >= count)
736 ext4_ext_drop_refs(orig_path);
737 err = get_ext_path(orig_inode, orig_off, &orig_path);
740 depth = ext_depth(orig_inode);
741 oext = orig_path[depth].p_ext;
742 if (le32_to_cpu(oext->ee_block) +
743 ext4_ext_get_actual_len(oext) <= orig_off) {
750 ext4_ext_drop_refs(donor_path);
751 err = get_ext_path(donor_inode, donor_off, &donor_path);
754 depth = ext_depth(donor_inode);
755 dext = donor_path[depth].p_ext;
756 if (le32_to_cpu(dext->ee_block) +
757 ext4_ext_get_actual_len(dext) <= donor_off) {
763 mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
765 count - replaced_count);
770 ext4_ext_drop_refs(orig_path);
774 ext4_ext_drop_refs(donor_path);
778 mext_double_up_write(orig_inode, donor_inode);
783 * move_extent_per_page - Move extent data per page
785 * @o_filp: file structure of original file
786 * @donor_inode: donor inode
787 * @orig_page_offset: page index on original file
788 * @data_offset_in_page: block index where data swapping starts
789 * @block_len_in_page: the number of blocks to be swapped
790 * @uninit: orig extent is uninitialized or not
792 * Save the data in original inode blocks and replace original inode extents
793 * with donor inode extents by calling mext_replace_branches().
794 * Finally, write out the saved data in new original inode blocks. Return 0
795 * on success, or a negative error value on failure.
798 move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
799 pgoff_t orig_page_offset, int data_offset_in_page,
800 int block_len_in_page, int uninit)
802 struct inode *orig_inode = o_filp->f_dentry->d_inode;
803 struct address_space *mapping = orig_inode->i_mapping;
804 struct buffer_head *bh;
805 struct page *page = NULL;
806 const struct address_space_operations *a_ops = mapping->a_ops;
808 ext4_lblk_t orig_blk_offset;
809 long long offs = orig_page_offset << PAGE_CACHE_SHIFT;
810 unsigned long blocksize = orig_inode->i_sb->s_blocksize;
811 unsigned int w_flags = 0;
812 unsigned int tmp_data_len, data_len;
815 int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits;
818 * It needs twice the amount of ordinary journal buffers because
819 * inode and donor_inode may change each different metadata blocks.
821 jblocks = ext4_writepage_trans_blocks(orig_inode) * 2;
822 handle = ext4_journal_start(orig_inode, jblocks);
823 if (IS_ERR(handle)) {
824 ret = PTR_ERR(handle);
828 if (segment_eq(get_fs(), KERNEL_DS))
829 w_flags |= AOP_FLAG_UNINTERRUPTIBLE;
831 orig_blk_offset = orig_page_offset * blocks_per_page +
835 * If orig extent is uninitialized one,
836 * it's not necessary force the page into memory
837 * and then force it to be written out again.
838 * Just swap data blocks between orig and donor.
841 ret = mext_replace_branches(handle, orig_inode,
842 donor_inode, orig_blk_offset,
845 /* Clear the inode cache not to refer to the old data */
846 ext4_ext_invalidate_cache(orig_inode);
847 ext4_ext_invalidate_cache(donor_inode);
851 offs = (long long)orig_blk_offset << orig_inode->i_blkbits;
853 /* Calculate data_len */
854 if ((orig_blk_offset + block_len_in_page - 1) ==
855 ((orig_inode->i_size - 1) >> orig_inode->i_blkbits)) {
856 /* Replace the last block */
857 tmp_data_len = orig_inode->i_size & (blocksize - 1);
859 * If data_len equal zero, it shows data_len is multiples of
860 * blocksize. So we set appropriate value.
862 if (tmp_data_len == 0)
863 tmp_data_len = blocksize;
865 data_len = tmp_data_len +
866 ((block_len_in_page - 1) << orig_inode->i_blkbits);
868 data_len = block_len_in_page << orig_inode->i_blkbits;
871 ret = a_ops->write_begin(o_filp, mapping, offs, data_len, w_flags,
873 if (unlikely(ret < 0))
876 if (!PageUptodate(page)) {
877 mapping->a_ops->readpage(o_filp, page);
882 * try_to_release_page() doesn't call releasepage in writeback mode.
883 * We should care about the order of writing to the same file
884 * by multiple move extent processes.
885 * It needs to call wait_on_page_writeback() to wait for the
886 * writeback of the page.
888 if (PageWriteback(page))
889 wait_on_page_writeback(page);
891 /* Release old bh and drop refs */
892 try_to_release_page(page, 0);
894 ret = mext_replace_branches(handle, orig_inode, donor_inode,
895 orig_blk_offset, block_len_in_page);
899 /* Clear the inode cache not to refer to the old data */
900 ext4_ext_invalidate_cache(orig_inode);
901 ext4_ext_invalidate_cache(donor_inode);
903 if (!page_has_buffers(page))
904 create_empty_buffers(page, 1 << orig_inode->i_blkbits, 0);
906 bh = page_buffers(page);
907 for (i = 0; i < data_offset_in_page; i++)
908 bh = bh->b_this_page;
910 for (i = 0; i < block_len_in_page; i++) {
911 ret = ext4_get_block(orig_inode,
912 (sector_t)(orig_blk_offset + i), bh, 0);
916 if (bh->b_this_page != NULL)
917 bh = bh->b_this_page;
920 ret = a_ops->write_end(o_filp, mapping, offs, data_len, data_len,
925 if (unlikely(page)) {
926 if (PageLocked(page))
928 page_cache_release(page);
929 ext4_journal_stop(handle);
932 ext4_journal_stop(handle);
934 return ret < 0 ? ret : 0;
938 * mext_check_argumants - Check whether move extent can be done
940 * @orig_inode: original inode
941 * @donor_inode: donor inode
942 * @orig_start: logical start offset in block for orig
943 * @donor_start: logical start offset in block for donor
944 * @len: the number of blocks to be moved
945 * @moved_len: moved block length
947 * Check the arguments of ext4_move_extents() whether the files can be
948 * exchanged with each other.
949 * Return 0 on success, or a negative error value on failure.
952 mext_check_arguments(struct inode *orig_inode,
953 struct inode *donor_inode, __u64 orig_start,
954 __u64 donor_start, __u64 *len, __u64 moved_len)
956 ext4_lblk_t orig_blocks, donor_blocks;
957 unsigned int blkbits = orig_inode->i_blkbits;
958 unsigned int blocksize = 1 << blkbits;
960 /* Regular file check */
961 if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) {
962 ext4_debug("ext4 move extent: The argument files should be "
963 "regular file [ino:orig %lu, donor %lu]\n",
964 orig_inode->i_ino, donor_inode->i_ino);
968 /* Ext4 move extent does not support swapfile */
969 if (IS_SWAPFILE(orig_inode) || IS_SWAPFILE(donor_inode)) {
970 ext4_debug("ext4 move extent: The argument files should "
971 "not be swapfile [ino:orig %lu, donor %lu]\n",
972 orig_inode->i_ino, donor_inode->i_ino);
976 /* Files should be in the same ext4 FS */
977 if (orig_inode->i_sb != donor_inode->i_sb) {
978 ext4_debug("ext4 move extent: The argument files "
979 "should be in same FS [ino:orig %lu, donor %lu]\n",
980 orig_inode->i_ino, donor_inode->i_ino);
984 /* orig and donor should be different file */
985 if (orig_inode->i_ino == donor_inode->i_ino) {
986 ext4_debug("ext4 move extent: The argument files should not "
987 "be same file [ino:orig %lu, donor %lu]\n",
988 orig_inode->i_ino, donor_inode->i_ino);
992 /* Ext4 move extent supports only extent based file */
993 if (!(EXT4_I(orig_inode)->i_flags & EXT4_EXTENTS_FL)) {
994 ext4_debug("ext4 move extent: orig file is not extents "
995 "based file [ino:orig %lu]\n", orig_inode->i_ino);
997 } else if (!(EXT4_I(donor_inode)->i_flags & EXT4_EXTENTS_FL)) {
998 ext4_debug("ext4 move extent: donor file is not extents "
999 "based file [ino:donor %lu]\n", donor_inode->i_ino);
1003 if ((!orig_inode->i_size) || (!donor_inode->i_size)) {
1004 ext4_debug("ext4 move extent: File size is 0 byte\n");
1008 /* Start offset should be same */
1009 if (orig_start != donor_start) {
1010 ext4_debug("ext4 move extent: orig and donor's start "
1011 "offset are not same [ino:orig %lu, donor %lu]\n",
1012 orig_inode->i_ino, donor_inode->i_ino);
1017 ext4_debug("ext4 move extent: moved_len should be 0 "
1018 "[ino:orig %lu, donor %lu]\n", orig_inode->i_ino,
1019 donor_inode->i_ino);
1023 if ((orig_start > MAX_DEFRAG_SIZE) ||
1024 (donor_start > MAX_DEFRAG_SIZE) ||
1025 (*len > MAX_DEFRAG_SIZE) ||
1026 (orig_start + *len > MAX_DEFRAG_SIZE)) {
1027 ext4_debug("ext4 move extent: Can't handle over [%lu] blocks "
1028 "[ino:orig %lu, donor %lu]\n", MAX_DEFRAG_SIZE,
1029 orig_inode->i_ino, donor_inode->i_ino);
1033 if (orig_inode->i_size > donor_inode->i_size) {
1034 donor_blocks = (donor_inode->i_size + blocksize - 1) >> blkbits;
1035 /* TODO: eliminate this artificial restriction */
1036 if (orig_start >= donor_blocks) {
1037 ext4_debug("ext4 move extent: orig start offset "
1038 "[%llu] should be less than donor file blocks "
1039 "[%u] [ino:orig %lu, donor %lu]\n",
1040 orig_start, donor_blocks,
1041 orig_inode->i_ino, donor_inode->i_ino);
1045 /* TODO: eliminate this artificial restriction */
1046 if (orig_start + *len > donor_blocks) {
1047 ext4_debug("ext4 move extent: End offset [%llu] should "
1048 "be less than donor file blocks [%u]."
1049 "So adjust length from %llu to %llu "
1050 "[ino:orig %lu, donor %lu]\n",
1051 orig_start + *len, donor_blocks,
1052 *len, donor_blocks - orig_start,
1053 orig_inode->i_ino, donor_inode->i_ino);
1054 *len = donor_blocks - orig_start;
1057 orig_blocks = (orig_inode->i_size + blocksize - 1) >> blkbits;
1058 if (orig_start >= orig_blocks) {
1059 ext4_debug("ext4 move extent: start offset [%llu] "
1060 "should be less than original file blocks "
1061 "[%u] [ino:orig %lu, donor %lu]\n",
1062 orig_start, orig_blocks,
1063 orig_inode->i_ino, donor_inode->i_ino);
1067 if (orig_start + *len > orig_blocks) {
1068 ext4_debug("ext4 move extent: Adjust length "
1069 "from %llu to %llu. Because it should be "
1070 "less than original file blocks "
1071 "[ino:orig %lu, donor %lu]\n",
1072 *len, orig_blocks - orig_start,
1073 orig_inode->i_ino, donor_inode->i_ino);
1074 *len = orig_blocks - orig_start;
1079 ext4_debug("ext4 move extent: len shoudld not be 0 "
1080 "[ino:orig %lu, donor %lu]\n", orig_inode->i_ino,
1081 donor_inode->i_ino);
1089 * mext_inode_double_lock - Lock i_mutex on both @inode1 and @inode2
1091 * @inode1: the inode structure
1092 * @inode2: the inode structure
1094 * Lock two inodes' i_mutex by i_ino order.
1095 * If inode1 or inode2 is NULL, return -EIO. Otherwise, return 0.
1098 mext_inode_double_lock(struct inode *inode1, struct inode *inode2)
1102 BUG_ON(inode1 == NULL && inode2 == NULL);
1104 ret = mext_check_null_inode(inode1, inode2, __func__);
1108 if (inode1 == inode2) {
1109 mutex_lock(&inode1->i_mutex);
1113 if (inode1->i_ino < inode2->i_ino) {
1114 mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT);
1115 mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD);
1117 mutex_lock_nested(&inode2->i_mutex, I_MUTEX_PARENT);
1118 mutex_lock_nested(&inode1->i_mutex, I_MUTEX_CHILD);
1126 * mext_inode_double_unlock - Release i_mutex on both @inode1 and @inode2
1128 * @inode1: the inode that is released first
1129 * @inode2: the inode that is released second
1131 * If inode1 or inode2 is NULL, return -EIO. Otherwise, return 0.
1135 mext_inode_double_unlock(struct inode *inode1, struct inode *inode2)
1139 BUG_ON(inode1 == NULL && inode2 == NULL);
1141 ret = mext_check_null_inode(inode1, inode2, __func__);
1146 mutex_unlock(&inode1->i_mutex);
1148 if (inode2 && inode2 != inode1)
1149 mutex_unlock(&inode2->i_mutex);
1156 * ext4_move_extents - Exchange the specified range of a file
1158 * @o_filp: file structure of the original file
1159 * @d_filp: file structure of the donor file
1160 * @orig_start: start offset in block for orig
1161 * @donor_start: start offset in block for donor
1162 * @len: the number of blocks to be moved
1163 * @moved_len: moved block length
1165 * This function returns 0 and moved block length is set in moved_len
1166 * if succeed, otherwise returns error value.
1168 * Note: ext4_move_extents() proceeds the following order.
1169 * 1:ext4_move_extents() calculates the last block number of moving extent
1170 * function by the start block number (orig_start) and the number of blocks
1171 * to be moved (len) specified as arguments.
1172 * If the {orig, donor}_start points a hole, the extent's start offset
1173 * pointed by ext_cur (current extent), holecheck_path, orig_path are set
1174 * after hole behind.
1175 * 2:Continue step 3 to step 5, until the holecheck_path points to last_extent
1176 * or the ext_cur exceeds the block_end which is last logical block number.
1177 * 3:To get the length of continues area, call mext_next_extent()
1178 * specified with the ext_cur (initial value is holecheck_path) re-cursive,
1179 * until find un-continuous extent, the start logical block number exceeds
1180 * the block_end or the extent points to the last extent.
1181 * 4:Exchange the original inode data with donor inode data
1182 * from orig_page_offset to seq_end_page.
1183 * The start indexes of data are specified as arguments.
1184 * That of the original inode is orig_page_offset,
1185 * and the donor inode is also orig_page_offset
1186 * (To easily handle blocksize != pagesize case, the offset for the
1187 * donor inode is block unit).
1188 * 5:Update holecheck_path and orig_path to points a next proceeding extent,
1189 * then returns to step 2.
1190 * 6:Release holecheck_path, orig_path and set the len to moved_len
1191 * which shows the number of moved blocks.
1192 * The moved_len is useful for the command to calculate the file offset
1193 * for starting next move extent ioctl.
1194 * 7:Return 0 on success, or a negative error value on failure.
1197 ext4_move_extents(struct file *o_filp, struct file *d_filp,
1198 __u64 orig_start, __u64 donor_start, __u64 len,
1201 struct inode *orig_inode = o_filp->f_dentry->d_inode;
1202 struct inode *donor_inode = d_filp->f_dentry->d_inode;
1203 struct ext4_ext_path *orig_path = NULL, *holecheck_path = NULL;
1204 struct ext4_extent *ext_prev, *ext_cur, *ext_dummy;
1205 ext4_lblk_t block_start = orig_start;
1206 ext4_lblk_t block_end, seq_start, add_blocks, file_end, seq_blocks = 0;
1207 ext4_lblk_t rest_blocks;
1208 pgoff_t orig_page_offset = 0, seq_end_page;
1209 int ret1, ret2, depth, last_extent = 0;
1210 int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits;
1211 int data_offset_in_page;
1212 int block_len_in_page;
1215 /* protect orig and donor against a truncate */
1216 ret1 = mext_inode_double_lock(orig_inode, donor_inode);
1220 mext_double_down_read(orig_inode, donor_inode);
1221 /* Check the filesystem environment whether move_extent can be done */
1222 ret1 = mext_check_arguments(orig_inode, donor_inode, orig_start,
1223 donor_start, &len, *moved_len);
1224 mext_double_up_read(orig_inode, donor_inode);
1228 file_end = (i_size_read(orig_inode) - 1) >> orig_inode->i_blkbits;
1229 block_end = block_start + len - 1;
1230 if (file_end < block_end)
1231 len -= block_end - file_end;
1233 ret1 = get_ext_path(orig_inode, block_start, &orig_path);
1237 /* Get path structure to check the hole */
1238 ret1 = get_ext_path(orig_inode, block_start, &holecheck_path);
1242 depth = ext_depth(orig_inode);
1243 ext_cur = holecheck_path[depth].p_ext;
1246 * Get proper extent whose ee_block is beyond block_start
1247 * if block_start was within the hole.
1249 if (le32_to_cpu(ext_cur->ee_block) +
1250 ext4_ext_get_actual_len(ext_cur) - 1 < block_start) {
1251 last_extent = mext_next_extent(orig_inode,
1252 holecheck_path, &ext_cur);
1253 if (last_extent < 0) {
1257 last_extent = mext_next_extent(orig_inode, orig_path,
1259 if (last_extent < 0) {
1264 seq_start = block_start;
1266 /* No blocks within the specified range. */
1267 if (le32_to_cpu(ext_cur->ee_block) > block_end) {
1268 ext4_debug("ext4 move extent: The specified range of file "
1269 "may be the hole\n");
1274 /* Adjust start blocks */
1275 add_blocks = min(le32_to_cpu(ext_cur->ee_block) +
1276 ext4_ext_get_actual_len(ext_cur), block_end + 1) -
1277 max(le32_to_cpu(ext_cur->ee_block), block_start);
1279 while (!last_extent && le32_to_cpu(ext_cur->ee_block) <= block_end) {
1280 seq_blocks += add_blocks;
1282 /* Adjust tail blocks */
1283 if (seq_start + seq_blocks - 1 > block_end)
1284 seq_blocks = block_end - seq_start + 1;
1287 last_extent = mext_next_extent(orig_inode, holecheck_path,
1289 if (last_extent < 0) {
1293 add_blocks = ext4_ext_get_actual_len(ext_cur);
1296 * Extend the length of contiguous block (seq_blocks)
1297 * if extents are contiguous.
1299 if (ext4_can_extents_be_merged(orig_inode,
1300 ext_prev, ext_cur) &&
1301 block_end >= le32_to_cpu(ext_cur->ee_block) &&
1305 /* Is original extent is uninitialized */
1306 uninit = ext4_ext_is_uninitialized(ext_prev);
1308 data_offset_in_page = seq_start % blocks_per_page;
1311 * Calculate data blocks count that should be swapped
1312 * at the first page.
1314 if (data_offset_in_page + seq_blocks > blocks_per_page) {
1315 /* Swapped blocks are across pages */
1317 blocks_per_page - data_offset_in_page;
1319 /* Swapped blocks are in a page */
1320 block_len_in_page = seq_blocks;
1323 orig_page_offset = seq_start >>
1324 (PAGE_CACHE_SHIFT - orig_inode->i_blkbits);
1325 seq_end_page = (seq_start + seq_blocks - 1) >>
1326 (PAGE_CACHE_SHIFT - orig_inode->i_blkbits);
1327 seq_start = le32_to_cpu(ext_cur->ee_block);
1328 rest_blocks = seq_blocks;
1330 /* Discard preallocations of two inodes */
1331 down_write(&EXT4_I(orig_inode)->i_data_sem);
1332 ext4_discard_preallocations(orig_inode);
1333 up_write(&EXT4_I(orig_inode)->i_data_sem);
1335 down_write(&EXT4_I(donor_inode)->i_data_sem);
1336 ext4_discard_preallocations(donor_inode);
1337 up_write(&EXT4_I(donor_inode)->i_data_sem);
1339 while (orig_page_offset <= seq_end_page) {
1341 /* Swap original branches with new branches */
1342 ret1 = move_extent_per_page(o_filp, donor_inode,
1344 data_offset_in_page,
1345 block_len_in_page, uninit);
1349 /* Count how many blocks we have exchanged */
1350 *moved_len += block_len_in_page;
1351 if (*moved_len > len) {
1352 ext4_error(orig_inode->i_sb, __func__,
1353 "We replaced blocks too much! "
1354 "sum of replaced: %llu requested: %llu",
1360 data_offset_in_page = 0;
1361 rest_blocks -= block_len_in_page;
1362 if (rest_blocks > blocks_per_page)
1363 block_len_in_page = blocks_per_page;
1365 block_len_in_page = rest_blocks;
1368 /* Decrease buffer counter */
1370 ext4_ext_drop_refs(holecheck_path);
1371 ret1 = get_ext_path(orig_inode, seq_start, &holecheck_path);
1374 depth = holecheck_path->p_depth;
1376 /* Decrease buffer counter */
1378 ext4_ext_drop_refs(orig_path);
1379 ret1 = get_ext_path(orig_inode, seq_start, &orig_path);
1383 ext_cur = holecheck_path[depth].p_ext;
1384 add_blocks = ext4_ext_get_actual_len(ext_cur);
1390 ext4_ext_drop_refs(orig_path);
1393 if (holecheck_path) {
1394 ext4_ext_drop_refs(holecheck_path);
1395 kfree(holecheck_path);
1398 ret2 = mext_inode_double_unlock(orig_inode, donor_inode);