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 <linux/slab.h>
19 #include "ext4_jbd2.h"
21 #include "ext4_extents.h"
24 * get_ext_path - Find an extent path for designated logical block number.
26 * @inode: an inode which is searched
27 * @lblock: logical block number to find an extent path
28 * @path: pointer to an extent path pointer (for output)
30 * ext4_ext_find_extent wrapper. Return 0 on success, or a negative error value
34 get_ext_path(struct inode *inode, ext4_lblk_t lblock,
35 struct ext4_ext_path **orig_path)
38 struct ext4_ext_path *path;
40 path = ext4_ext_find_extent(inode, lblock, *orig_path);
43 else if (path[ext_depth(inode)].p_ext == NULL)
52 * copy_extent_status - Copy the extent's initialization status
54 * @src: an extent for getting initialize status
55 * @dest: an extent to be set the status
58 copy_extent_status(struct ext4_extent *src, struct ext4_extent *dest)
60 if (ext4_ext_is_uninitialized(src))
61 ext4_ext_mark_uninitialized(dest);
63 dest->ee_len = cpu_to_le16(ext4_ext_get_actual_len(dest));
67 * mext_next_extent - Search for the next extent and set it to "extent"
69 * @inode: inode which is searched
70 * @path: this will obtain data for the next extent
71 * @extent: pointer to the next extent we have just gotten
73 * Search the next extent in the array of ext4_ext_path structure (@path)
74 * and set it to ext4_extent structure (@extent). In addition, the member of
75 * @path (->p_ext) also points the next extent. Return 0 on success, 1 if
76 * ext4_ext_path structure refers to the last extent, or a negative error
80 mext_next_extent(struct inode *inode, struct ext4_ext_path *path,
81 struct ext4_extent **extent)
83 struct ext4_extent_header *eh;
84 int ppos, leaf_ppos = path->p_depth;
87 if (EXT_LAST_EXTENT(path[ppos].p_hdr) > path[ppos].p_ext) {
89 *extent = ++path[ppos].p_ext;
90 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
95 if (EXT_LAST_INDEX(path[ppos].p_hdr) >
101 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
102 if (path[ppos+1].p_bh)
103 brelse(path[ppos+1].p_bh);
105 sb_bread(inode->i_sb, path[ppos].p_block);
106 if (!path[ppos+1].p_bh)
109 ext_block_hdr(path[ppos+1].p_bh);
111 /* Halfway index block */
112 while (++cur_ppos < leaf_ppos) {
113 path[cur_ppos].p_idx =
114 EXT_FIRST_INDEX(path[cur_ppos].p_hdr);
115 path[cur_ppos].p_block =
116 ext4_idx_pblock(path[cur_ppos].p_idx);
117 if (path[cur_ppos+1].p_bh)
118 brelse(path[cur_ppos+1].p_bh);
119 path[cur_ppos+1].p_bh = sb_bread(inode->i_sb,
120 path[cur_ppos].p_block);
121 if (!path[cur_ppos+1].p_bh)
123 path[cur_ppos+1].p_hdr =
124 ext_block_hdr(path[cur_ppos+1].p_bh);
127 path[leaf_ppos].p_ext = *extent = NULL;
129 eh = path[leaf_ppos].p_hdr;
130 if (le16_to_cpu(eh->eh_entries) == 0)
131 /* empty leaf is found */
135 path[leaf_ppos].p_ext = *extent =
136 EXT_FIRST_EXTENT(path[leaf_ppos].p_hdr);
137 path[leaf_ppos].p_block =
138 ext4_ext_pblock(path[leaf_ppos].p_ext);
142 /* We found the last extent */
147 * double_down_write_data_sem - Acquire two inodes' write lock of i_data_sem
149 * Acquire write lock of i_data_sem of the two inodes
152 double_down_write_data_sem(struct inode *first, struct inode *second)
154 if (first < second) {
155 down_write(&EXT4_I(first)->i_data_sem);
156 down_write_nested(&EXT4_I(second)->i_data_sem, SINGLE_DEPTH_NESTING);
158 down_write(&EXT4_I(second)->i_data_sem);
159 down_write_nested(&EXT4_I(first)->i_data_sem, SINGLE_DEPTH_NESTING);
165 * double_up_write_data_sem - Release two inodes' write lock of i_data_sem
167 * @orig_inode: original inode structure to be released its lock first
168 * @donor_inode: donor inode structure to be released its lock second
169 * Release write lock of i_data_sem of two inodes (orig and donor).
172 double_up_write_data_sem(struct inode *orig_inode, struct inode *donor_inode)
174 up_write(&EXT4_I(orig_inode)->i_data_sem);
175 up_write(&EXT4_I(donor_inode)->i_data_sem);
179 * mext_insert_across_blocks - Insert extents across leaf block
181 * @handle: journal handle
182 * @orig_inode: original inode
183 * @o_start: first original extent to be changed
184 * @o_end: last original extent to be changed
185 * @start_ext: first new extent to be inserted
186 * @new_ext: middle of new extent to be inserted
187 * @end_ext: last new extent to be inserted
189 * Allocate a new leaf block and insert extents into it. Return 0 on success,
190 * or a negative error value on failure.
193 mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode,
194 struct ext4_extent *o_start, struct ext4_extent *o_end,
195 struct ext4_extent *start_ext, struct ext4_extent *new_ext,
196 struct ext4_extent *end_ext)
198 struct ext4_ext_path *orig_path = NULL;
199 ext4_lblk_t eblock = 0;
204 if (start_ext->ee_len && new_ext->ee_len && end_ext->ee_len) {
205 if (o_start == o_end) {
207 /* start_ext new_ext end_ext
208 * donor |---------|-----------|--------|
209 * orig |------------------------------|
214 /* start_ext new_ext end_ext
215 * donor |---------|----------|---------|
216 * orig |---------------|--------------|
218 o_end->ee_block = end_ext->ee_block;
219 o_end->ee_len = end_ext->ee_len;
220 ext4_ext_store_pblock(o_end, ext4_ext_pblock(end_ext));
223 o_start->ee_len = start_ext->ee_len;
224 eblock = le32_to_cpu(start_ext->ee_block);
227 } else if (start_ext->ee_len && new_ext->ee_len &&
228 !end_ext->ee_len && o_start == o_end) {
231 * donor |--------------|---------------|
232 * orig |------------------------------|
234 o_start->ee_len = start_ext->ee_len;
235 eblock = le32_to_cpu(start_ext->ee_block);
238 } else if (!start_ext->ee_len && new_ext->ee_len &&
239 end_ext->ee_len && o_start == o_end) {
242 * donor |--------------|---------------|
243 * orig |------------------------------|
245 o_end->ee_block = end_ext->ee_block;
246 o_end->ee_len = end_ext->ee_len;
247 ext4_ext_store_pblock(o_end, ext4_ext_pblock(end_ext));
250 * Set 0 to the extent block if new_ext was
253 if (new_ext->ee_block)
254 eblock = le32_to_cpu(new_ext->ee_block);
258 ext4_debug("ext4 move extent: Unexpected insert case\n");
263 err = get_ext_path(orig_inode, eblock, &orig_path);
267 if (ext4_ext_insert_extent(handle, orig_inode,
268 orig_path, new_ext, 0))
273 err = get_ext_path(orig_inode,
274 le32_to_cpu(end_ext->ee_block) - 1, &orig_path);
278 if (ext4_ext_insert_extent(handle, orig_inode,
279 orig_path, end_ext, 0))
284 ext4_ext_drop_refs(orig_path);
293 * mext_insert_inside_block - Insert new extent to the extent block
295 * @o_start: first original extent to be moved
296 * @o_end: last original extent to be moved
297 * @start_ext: first new extent to be inserted
298 * @new_ext: middle of new extent to be inserted
299 * @end_ext: last new extent to be inserted
300 * @eh: extent header of target leaf block
301 * @range_to_move: used to decide how to insert extent
303 * Insert extents into the leaf block. The extent (@o_start) is overwritten
304 * by inserted extents.
307 mext_insert_inside_block(struct ext4_extent *o_start,
308 struct ext4_extent *o_end,
309 struct ext4_extent *start_ext,
310 struct ext4_extent *new_ext,
311 struct ext4_extent *end_ext,
312 struct ext4_extent_header *eh,
318 /* Move the existing extents */
319 if (range_to_move && o_end < EXT_LAST_EXTENT(eh)) {
320 len = (unsigned long)(EXT_LAST_EXTENT(eh) + 1) -
321 (unsigned long)(o_end + 1);
322 memmove(o_end + 1 + range_to_move, o_end + 1, len);
325 /* Insert start entry */
326 if (start_ext->ee_len)
327 o_start[i++].ee_len = start_ext->ee_len;
329 /* Insert new entry */
330 if (new_ext->ee_len) {
331 o_start[i] = *new_ext;
332 ext4_ext_store_pblock(&o_start[i++], ext4_ext_pblock(new_ext));
335 /* Insert end entry */
337 o_start[i] = *end_ext;
339 /* Increment the total entries counter on the extent block */
340 le16_add_cpu(&eh->eh_entries, range_to_move);
344 * mext_insert_extents - Insert new extent
346 * @handle: journal handle
347 * @orig_inode: original inode
348 * @orig_path: path indicates first extent to be changed
349 * @o_start: first original extent to be changed
350 * @o_end: last original extent to be changed
351 * @start_ext: first new extent to be inserted
352 * @new_ext: middle of new extent to be inserted
353 * @end_ext: last new extent to be inserted
355 * Call the function to insert extents. If we cannot add more extents into
356 * the leaf block, we call mext_insert_across_blocks() to create a
357 * new leaf block. Otherwise call mext_insert_inside_block(). Return 0
358 * on success, or a negative error value on failure.
361 mext_insert_extents(handle_t *handle, struct inode *orig_inode,
362 struct ext4_ext_path *orig_path,
363 struct ext4_extent *o_start,
364 struct ext4_extent *o_end,
365 struct ext4_extent *start_ext,
366 struct ext4_extent *new_ext,
367 struct ext4_extent *end_ext)
369 struct ext4_extent_header *eh;
370 unsigned long need_slots, slots_range;
371 int range_to_move, depth, ret;
374 * The extents need to be inserted
375 * start_extent + new_extent + end_extent.
377 need_slots = (start_ext->ee_len ? 1 : 0) + (end_ext->ee_len ? 1 : 0) +
378 (new_ext->ee_len ? 1 : 0);
380 /* The number of slots between start and end */
381 slots_range = ((unsigned long)(o_end + 1) - (unsigned long)o_start + 1)
382 / sizeof(struct ext4_extent);
384 /* Range to move the end of extent */
385 range_to_move = need_slots - slots_range;
386 depth = orig_path->p_depth;
388 eh = orig_path->p_hdr;
391 /* Register to journal */
392 ret = ext4_journal_get_write_access(handle, orig_path->p_bh);
398 if (range_to_move > 0 &&
399 (range_to_move > le16_to_cpu(eh->eh_max)
400 - le16_to_cpu(eh->eh_entries))) {
402 ret = mext_insert_across_blocks(handle, orig_inode, o_start,
403 o_end, start_ext, new_ext, end_ext);
407 mext_insert_inside_block(o_start, o_end, start_ext, new_ext,
408 end_ext, eh, range_to_move);
411 ret = ext4_handle_dirty_metadata(handle, orig_inode,
416 ret = ext4_mark_inode_dirty(handle, orig_inode);
425 * mext_leaf_block - Move one leaf extent block into the inode.
427 * @handle: journal handle
428 * @orig_inode: original inode
429 * @orig_path: path indicates first extent to be changed
430 * @dext: donor extent
431 * @from: start offset on the target file
433 * In order to insert extents into the leaf block, we must divide the extent
434 * in the leaf block into three extents. The one is located to be inserted
435 * extents, and the others are located around it.
437 * Therefore, this function creates structures to save extents of the leaf
438 * block, and inserts extents by calling mext_insert_extents() with
439 * created extents. Return 0 on success, or a negative error value on failure.
442 mext_leaf_block(handle_t *handle, struct inode *orig_inode,
443 struct ext4_ext_path *orig_path, struct ext4_extent *dext,
446 struct ext4_extent *oext, *o_start, *o_end, *prev_ext;
447 struct ext4_extent new_ext, start_ext, end_ext;
448 ext4_lblk_t new_ext_end;
449 int oext_alen, new_ext_alen, end_ext_alen;
450 int depth = ext_depth(orig_inode);
453 start_ext.ee_block = end_ext.ee_block = 0;
454 o_start = o_end = oext = orig_path[depth].p_ext;
455 oext_alen = ext4_ext_get_actual_len(oext);
456 start_ext.ee_len = end_ext.ee_len = 0;
458 new_ext.ee_block = cpu_to_le32(*from);
459 ext4_ext_store_pblock(&new_ext, ext4_ext_pblock(dext));
460 new_ext.ee_len = dext->ee_len;
461 new_ext_alen = ext4_ext_get_actual_len(&new_ext);
462 new_ext_end = le32_to_cpu(new_ext.ee_block) + new_ext_alen - 1;
465 * Case: original extent is first
470 if (le32_to_cpu(oext->ee_block) < le32_to_cpu(new_ext.ee_block) &&
471 le32_to_cpu(new_ext.ee_block) <
472 le32_to_cpu(oext->ee_block) + oext_alen) {
473 start_ext.ee_len = cpu_to_le16(le32_to_cpu(new_ext.ee_block) -
474 le32_to_cpu(oext->ee_block));
475 start_ext.ee_block = oext->ee_block;
476 copy_extent_status(oext, &start_ext);
477 } else if (oext > EXT_FIRST_EXTENT(orig_path[depth].p_hdr)) {
480 * We can merge new_ext into previous extent,
481 * if these are contiguous and same extent type.
483 if (ext4_can_extents_be_merged(orig_inode, prev_ext,
486 start_ext.ee_len = cpu_to_le16(
487 ext4_ext_get_actual_len(prev_ext) +
489 start_ext.ee_block = oext->ee_block;
490 copy_extent_status(prev_ext, &start_ext);
496 * Case: new_ext_end must be less than oext
500 if (le32_to_cpu(oext->ee_block) + oext_alen - 1 < new_ext_end) {
501 EXT4_ERROR_INODE(orig_inode,
502 "new_ext_end(%u) should be less than or equal to "
503 "oext->ee_block(%u) + oext_alen(%d) - 1",
504 new_ext_end, le32_to_cpu(oext->ee_block),
511 * Case: new_ext is smaller than original extent
512 * oext |---------------|
513 * new_ext |-----------|
516 if (le32_to_cpu(oext->ee_block) <= new_ext_end &&
517 new_ext_end < le32_to_cpu(oext->ee_block) + oext_alen - 1) {
519 cpu_to_le16(le32_to_cpu(oext->ee_block) +
520 oext_alen - 1 - new_ext_end);
521 copy_extent_status(oext, &end_ext);
522 end_ext_alen = ext4_ext_get_actual_len(&end_ext);
523 ext4_ext_store_pblock(&end_ext,
524 (ext4_ext_pblock(o_end) + oext_alen - end_ext_alen));
526 cpu_to_le32(le32_to_cpu(o_end->ee_block) +
527 oext_alen - end_ext_alen);
530 ret = mext_insert_extents(handle, orig_inode, orig_path, o_start,
531 o_end, &start_ext, &new_ext, &end_ext);
537 * mext_calc_swap_extents - Calculate extents for extent swapping.
539 * @tmp_dext: the extent that will belong to the original inode
540 * @tmp_oext: the extent that will belong to the donor inode
541 * @orig_off: block offset of original inode
542 * @donor_off: block offset of donor inode
543 * @max_count: the maximum length of extents
545 * Return 0 on success, or a negative error value on failure.
548 mext_calc_swap_extents(struct ext4_extent *tmp_dext,
549 struct ext4_extent *tmp_oext,
550 ext4_lblk_t orig_off, ext4_lblk_t donor_off,
551 ext4_lblk_t max_count)
553 ext4_lblk_t diff, orig_diff;
554 struct ext4_extent dext_old, oext_old;
556 BUG_ON(orig_off != donor_off);
558 /* original and donor extents have to cover the same block offset */
559 if (orig_off < le32_to_cpu(tmp_oext->ee_block) ||
560 le32_to_cpu(tmp_oext->ee_block) +
561 ext4_ext_get_actual_len(tmp_oext) - 1 < orig_off)
564 if (orig_off < le32_to_cpu(tmp_dext->ee_block) ||
565 le32_to_cpu(tmp_dext->ee_block) +
566 ext4_ext_get_actual_len(tmp_dext) - 1 < orig_off)
569 dext_old = *tmp_dext;
570 oext_old = *tmp_oext;
572 /* When tmp_dext is too large, pick up the target range. */
573 diff = donor_off - le32_to_cpu(tmp_dext->ee_block);
575 ext4_ext_store_pblock(tmp_dext, ext4_ext_pblock(tmp_dext) + diff);
576 le32_add_cpu(&tmp_dext->ee_block, diff);
577 le16_add_cpu(&tmp_dext->ee_len, -diff);
579 if (max_count < ext4_ext_get_actual_len(tmp_dext))
580 tmp_dext->ee_len = cpu_to_le16(max_count);
582 orig_diff = orig_off - le32_to_cpu(tmp_oext->ee_block);
583 ext4_ext_store_pblock(tmp_oext, ext4_ext_pblock(tmp_oext) + orig_diff);
585 /* Adjust extent length if donor extent is larger than orig */
586 if (ext4_ext_get_actual_len(tmp_dext) >
587 ext4_ext_get_actual_len(tmp_oext) - orig_diff)
588 tmp_dext->ee_len = cpu_to_le16(le16_to_cpu(tmp_oext->ee_len) -
591 tmp_oext->ee_len = cpu_to_le16(ext4_ext_get_actual_len(tmp_dext));
593 copy_extent_status(&oext_old, tmp_dext);
594 copy_extent_status(&dext_old, tmp_oext);
600 * mext_check_coverage - Check that all extents in range has the same type
602 * @inode: inode in question
603 * @from: block offset of inode
604 * @count: block count to be checked
605 * @uninit: extents expected to be uninitialized
606 * @err: pointer to save error value
608 * Return 1 if all extents in range has expected type, and zero otherwise.
611 mext_check_coverage(struct inode *inode, ext4_lblk_t from, ext4_lblk_t count,
612 int uninit, int *err)
614 struct ext4_ext_path *path = NULL;
615 struct ext4_extent *ext;
617 ext4_lblk_t last = from + count;
618 while (from < last) {
619 *err = get_ext_path(inode, from, &path);
622 ext = path[ext_depth(inode)].p_ext;
623 if (uninit != ext4_ext_is_uninitialized(ext))
625 from += ext4_ext_get_actual_len(ext);
626 ext4_ext_drop_refs(path);
631 ext4_ext_drop_refs(path);
638 * mext_replace_branches - Replace original extents with new extents
640 * @handle: journal handle
641 * @orig_inode: original inode
642 * @donor_inode: donor inode
643 * @from: block offset of orig_inode
644 * @count: block count to be replaced
645 * @err: pointer to save return value
647 * Replace original inode extents and donor inode extents page by page.
648 * We implement this replacement in the following three steps:
649 * 1. Save the block information of original and donor inodes into
651 * 2. Change the block information of original inode to point at the
652 * donor inode blocks.
653 * 3. Change the block information of donor inode to point at the saved
654 * original inode blocks in the dummy extents.
656 * Return replaced block count.
659 mext_replace_branches(handle_t *handle, struct inode *orig_inode,
660 struct inode *donor_inode, ext4_lblk_t from,
661 ext4_lblk_t count, int *err)
663 struct ext4_ext_path *orig_path = NULL;
664 struct ext4_ext_path *donor_path = NULL;
665 struct ext4_extent *oext, *dext;
666 struct ext4_extent tmp_dext, tmp_oext;
667 ext4_lblk_t orig_off = from, donor_off = from;
669 int replaced_count = 0;
672 *err = ext4_es_remove_extent(orig_inode, from, count);
676 *err = ext4_es_remove_extent(donor_inode, from, count);
680 /* Get the original extent for the block "orig_off" */
681 *err = get_ext_path(orig_inode, orig_off, &orig_path);
685 /* Get the donor extent for the head */
686 *err = get_ext_path(donor_inode, donor_off, &donor_path);
689 depth = ext_depth(orig_inode);
690 oext = orig_path[depth].p_ext;
693 depth = ext_depth(donor_inode);
694 dext = donor_path[depth].p_ext;
696 goto missing_donor_extent;
699 *err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
704 /* Loop for the donor extents */
706 /* The extent for donor must be found. */
707 if (unlikely(!dext)) {
708 missing_donor_extent:
709 EXT4_ERROR_INODE(donor_inode,
710 "The extent for donor must be found");
713 } else if (donor_off != le32_to_cpu(tmp_dext.ee_block)) {
714 EXT4_ERROR_INODE(donor_inode,
715 "Donor offset(%u) and the first block of donor "
716 "extent(%u) should be equal",
718 le32_to_cpu(tmp_dext.ee_block));
723 /* Set donor extent to orig extent */
724 *err = mext_leaf_block(handle, orig_inode,
725 orig_path, &tmp_dext, &orig_off);
729 /* Set orig extent to donor extent */
730 *err = mext_leaf_block(handle, donor_inode,
731 donor_path, &tmp_oext, &donor_off);
735 dext_alen = ext4_ext_get_actual_len(&tmp_dext);
736 replaced_count += dext_alen;
737 donor_off += dext_alen;
738 orig_off += dext_alen;
740 /* Already moved the expected blocks */
741 if (replaced_count >= count)
745 ext4_ext_drop_refs(orig_path);
746 *err = get_ext_path(orig_inode, orig_off, &orig_path);
749 depth = ext_depth(orig_inode);
750 oext = orig_path[depth].p_ext;
754 ext4_ext_drop_refs(donor_path);
755 *err = get_ext_path(donor_inode, donor_off, &donor_path);
758 depth = ext_depth(donor_inode);
759 dext = donor_path[depth].p_ext;
762 *err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
763 donor_off, count - replaced_count);
770 ext4_ext_drop_refs(orig_path);
774 ext4_ext_drop_refs(donor_path);
778 return replaced_count;
782 * mext_page_double_lock - Grab and lock pages on both @inode1 and @inode2
784 * @inode1: the inode structure
785 * @inode2: the inode structure
787 * @page: result page vector
789 * Grab two locked pages for inode's by inode order
792 mext_page_double_lock(struct inode *inode1, struct inode *inode2,
793 pgoff_t index, struct page *page[2])
795 struct address_space *mapping[2];
796 unsigned fl = AOP_FLAG_NOFS;
798 BUG_ON(!inode1 || !inode2);
799 if (inode1 < inode2) {
800 mapping[0] = inode1->i_mapping;
801 mapping[1] = inode2->i_mapping;
803 mapping[0] = inode2->i_mapping;
804 mapping[1] = inode1->i_mapping;
807 page[0] = grab_cache_page_write_begin(mapping[0], index, fl);
811 page[1] = grab_cache_page_write_begin(mapping[1], index, fl);
813 unlock_page(page[0]);
814 page_cache_release(page[0]);
818 if (inode1 > inode2) {
827 /* Force page buffers uptodate w/o dropping page's lock */
829 mext_page_mkuptodate(struct page *page, unsigned from, unsigned to)
831 struct inode *inode = page->mapping->host;
833 struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
834 unsigned int blocksize, block_start, block_end;
835 int i, err, nr = 0, partial = 0;
836 BUG_ON(!PageLocked(page));
837 BUG_ON(PageWriteback(page));
839 if (PageUptodate(page))
842 blocksize = 1 << inode->i_blkbits;
843 if (!page_has_buffers(page))
844 create_empty_buffers(page, blocksize, 0);
846 head = page_buffers(page);
847 block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
848 for (bh = head, block_start = 0; bh != head || !block_start;
849 block++, block_start = block_end, bh = bh->b_this_page) {
850 block_end = block_start + blocksize;
851 if (block_end <= from || block_start >= to) {
852 if (!buffer_uptodate(bh))
856 if (buffer_uptodate(bh))
858 if (!buffer_mapped(bh)) {
860 err = ext4_get_block(inode, block, bh, 0);
865 if (!buffer_mapped(bh)) {
866 zero_user(page, block_start, blocksize);
868 set_buffer_uptodate(bh);
872 BUG_ON(nr >= MAX_BUF_PER_PAGE);
879 for (i = 0; i < nr; i++) {
881 if (!bh_uptodate_or_lock(bh)) {
882 err = bh_submit_read(bh);
889 SetPageUptodate(page);
894 * move_extent_per_page - Move extent data per page
896 * @o_filp: file structure of original file
897 * @donor_inode: donor inode
898 * @orig_page_offset: page index on original file
899 * @data_offset_in_page: block index where data swapping starts
900 * @block_len_in_page: the number of blocks to be swapped
901 * @uninit: orig extent is uninitialized or not
902 * @err: pointer to save return value
904 * Save the data in original inode blocks and replace original inode extents
905 * with donor inode extents by calling mext_replace_branches().
906 * Finally, write out the saved data in new original inode blocks. Return
907 * replaced block count.
910 move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
911 pgoff_t orig_page_offset, int data_offset_in_page,
912 int block_len_in_page, int uninit, int *err)
914 struct inode *orig_inode = file_inode(o_filp);
915 struct page *pagep[2] = {NULL, NULL};
917 ext4_lblk_t orig_blk_offset;
918 long long offs = orig_page_offset << PAGE_CACHE_SHIFT;
919 unsigned long blocksize = orig_inode->i_sb->s_blocksize;
920 unsigned int w_flags = 0;
921 unsigned int tmp_data_size, data_size, replaced_size;
922 int err2, jblocks, retries = 0;
923 int replaced_count = 0;
924 int from = data_offset_in_page << orig_inode->i_blkbits;
925 int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits;
928 * It needs twice the amount of ordinary journal buffers because
929 * inode and donor_inode may change each different metadata blocks.
933 jblocks = ext4_writepage_trans_blocks(orig_inode) * 2;
934 handle = ext4_journal_start(orig_inode, EXT4_HT_MOVE_EXTENTS, jblocks);
935 if (IS_ERR(handle)) {
936 *err = PTR_ERR(handle);
940 if (segment_eq(get_fs(), KERNEL_DS))
941 w_flags |= AOP_FLAG_UNINTERRUPTIBLE;
943 orig_blk_offset = orig_page_offset * blocks_per_page +
946 offs = (long long)orig_blk_offset << orig_inode->i_blkbits;
948 /* Calculate data_size */
949 if ((orig_blk_offset + block_len_in_page - 1) ==
950 ((orig_inode->i_size - 1) >> orig_inode->i_blkbits)) {
951 /* Replace the last block */
952 tmp_data_size = orig_inode->i_size & (blocksize - 1);
954 * If data_size equal zero, it shows data_size is multiples of
955 * blocksize. So we set appropriate value.
957 if (tmp_data_size == 0)
958 tmp_data_size = blocksize;
960 data_size = tmp_data_size +
961 ((block_len_in_page - 1) << orig_inode->i_blkbits);
963 data_size = block_len_in_page << orig_inode->i_blkbits;
965 replaced_size = data_size;
967 *err = mext_page_double_lock(orig_inode, donor_inode, orig_page_offset,
969 if (unlikely(*err < 0))
972 * If orig extent was uninitialized it can become initialized
973 * at any time after i_data_sem was dropped, in order to
974 * serialize with delalloc we have recheck extent while we
975 * hold page's lock, if it is still the case data copy is not
976 * necessary, just swap data blocks between orig and donor.
979 double_down_write_data_sem(orig_inode, donor_inode);
980 /* If any of extents in range became initialized we have to
981 * fallback to data copying */
982 uninit = mext_check_coverage(orig_inode, orig_blk_offset,
983 block_len_in_page, 1, err);
987 uninit &= mext_check_coverage(donor_inode, orig_blk_offset,
988 block_len_in_page, 1, err);
993 double_up_write_data_sem(orig_inode, donor_inode);
996 if ((page_has_private(pagep[0]) &&
997 !try_to_release_page(pagep[0], 0)) ||
998 (page_has_private(pagep[1]) &&
999 !try_to_release_page(pagep[1], 0))) {
1003 replaced_count = mext_replace_branches(handle, orig_inode,
1004 donor_inode, orig_blk_offset,
1005 block_len_in_page, err);
1007 double_up_write_data_sem(orig_inode, donor_inode);
1011 *err = mext_page_mkuptodate(pagep[0], from, from + replaced_size);
1015 /* At this point all buffers in range are uptodate, old mapping layout
1016 * is no longer required, try to drop it now. */
1017 if ((page_has_private(pagep[0]) && !try_to_release_page(pagep[0], 0)) ||
1018 (page_has_private(pagep[1]) && !try_to_release_page(pagep[1], 0))) {
1023 replaced_count = mext_replace_branches(handle, orig_inode, donor_inode,
1025 block_len_in_page, err);
1027 if (replaced_count) {
1028 block_len_in_page = replaced_count;
1030 block_len_in_page << orig_inode->i_blkbits;
1034 /* Perform all necessary steps similar write_begin()/write_end()
1035 * but keeping in mind that i_size will not change */
1036 *err = __block_write_begin(pagep[0], from, from + replaced_size,
1039 *err = block_commit_write(pagep[0], from, from + replaced_size);
1041 if (unlikely(*err < 0))
1042 goto repair_branches;
1044 /* Even in case of data=writeback it is reasonable to pin
1045 * inode to transaction, to prevent unexpected data loss */
1046 *err = ext4_jbd2_file_inode(handle, orig_inode);
1049 unlock_page(pagep[0]);
1050 page_cache_release(pagep[0]);
1051 unlock_page(pagep[1]);
1052 page_cache_release(pagep[1]);
1054 ext4_journal_stop(handle);
1055 /* Buffer was busy because probably is pinned to journal transaction,
1056 * force transaction commit may help to free it. */
1057 if (*err == -EBUSY && ext4_should_retry_alloc(orig_inode->i_sb,
1060 return replaced_count;
1064 * This should never ever happen!
1065 * Extents are swapped already, but we are not able to copy data.
1066 * Try to swap extents to it's original places
1068 double_down_write_data_sem(orig_inode, donor_inode);
1069 replaced_count = mext_replace_branches(handle, donor_inode, orig_inode,
1071 block_len_in_page, &err2);
1072 double_up_write_data_sem(orig_inode, donor_inode);
1073 if (replaced_count != block_len_in_page) {
1074 EXT4_ERROR_INODE_BLOCK(orig_inode, (sector_t)(orig_blk_offset),
1075 "Unable to copy data block,"
1076 " data will be lost.");
1084 * mext_check_arguments - Check whether move extent can be done
1086 * @orig_inode: original inode
1087 * @donor_inode: donor inode
1088 * @orig_start: logical start offset in block for orig
1089 * @donor_start: logical start offset in block for donor
1090 * @len: the number of blocks to be moved
1092 * Check the arguments of ext4_move_extents() whether the files can be
1093 * exchanged with each other.
1094 * Return 0 on success, or a negative error value on failure.
1097 mext_check_arguments(struct inode *orig_inode,
1098 struct inode *donor_inode, __u64 orig_start,
1099 __u64 donor_start, __u64 *len)
1101 ext4_lblk_t orig_blocks, donor_blocks;
1102 unsigned int blkbits = orig_inode->i_blkbits;
1103 unsigned int blocksize = 1 << blkbits;
1105 if (donor_inode->i_mode & (S_ISUID|S_ISGID)) {
1106 ext4_debug("ext4 move extent: suid or sgid is set"
1107 " to donor file [ino:orig %lu, donor %lu]\n",
1108 orig_inode->i_ino, donor_inode->i_ino);
1112 if (IS_IMMUTABLE(donor_inode) || IS_APPEND(donor_inode))
1115 /* Ext4 move extent does not support swapfile */
1116 if (IS_SWAPFILE(orig_inode) || IS_SWAPFILE(donor_inode)) {
1117 ext4_debug("ext4 move extent: The argument files should "
1118 "not be swapfile [ino:orig %lu, donor %lu]\n",
1119 orig_inode->i_ino, donor_inode->i_ino);
1123 /* Ext4 move extent supports only extent based file */
1124 if (!(ext4_test_inode_flag(orig_inode, EXT4_INODE_EXTENTS))) {
1125 ext4_debug("ext4 move extent: orig file is not extents "
1126 "based file [ino:orig %lu]\n", orig_inode->i_ino);
1128 } else if (!(ext4_test_inode_flag(donor_inode, EXT4_INODE_EXTENTS))) {
1129 ext4_debug("ext4 move extent: donor file is not extents "
1130 "based file [ino:donor %lu]\n", donor_inode->i_ino);
1134 if ((!orig_inode->i_size) || (!donor_inode->i_size)) {
1135 ext4_debug("ext4 move extent: File size is 0 byte\n");
1139 /* Start offset should be same */
1140 if (orig_start != donor_start) {
1141 ext4_debug("ext4 move extent: orig and donor's start "
1142 "offset are not same [ino:orig %lu, donor %lu]\n",
1143 orig_inode->i_ino, donor_inode->i_ino);
1147 if ((orig_start >= EXT_MAX_BLOCKS) ||
1148 (*len > EXT_MAX_BLOCKS) ||
1149 (orig_start + *len >= EXT_MAX_BLOCKS)) {
1150 ext4_debug("ext4 move extent: Can't handle over [%u] blocks "
1151 "[ino:orig %lu, donor %lu]\n", EXT_MAX_BLOCKS,
1152 orig_inode->i_ino, donor_inode->i_ino);
1156 if (orig_inode->i_size > donor_inode->i_size) {
1157 donor_blocks = (donor_inode->i_size + blocksize - 1) >> blkbits;
1158 /* TODO: eliminate this artificial restriction */
1159 if (orig_start >= donor_blocks) {
1160 ext4_debug("ext4 move extent: orig start offset "
1161 "[%llu] should be less than donor file blocks "
1162 "[%u] [ino:orig %lu, donor %lu]\n",
1163 orig_start, donor_blocks,
1164 orig_inode->i_ino, donor_inode->i_ino);
1168 /* TODO: eliminate this artificial restriction */
1169 if (orig_start + *len > donor_blocks) {
1170 ext4_debug("ext4 move extent: End offset [%llu] should "
1171 "be less than donor file blocks [%u]."
1172 "So adjust length from %llu to %llu "
1173 "[ino:orig %lu, donor %lu]\n",
1174 orig_start + *len, donor_blocks,
1175 *len, donor_blocks - orig_start,
1176 orig_inode->i_ino, donor_inode->i_ino);
1177 *len = donor_blocks - orig_start;
1180 orig_blocks = (orig_inode->i_size + blocksize - 1) >> blkbits;
1181 if (orig_start >= orig_blocks) {
1182 ext4_debug("ext4 move extent: start offset [%llu] "
1183 "should be less than original file blocks "
1184 "[%u] [ino:orig %lu, donor %lu]\n",
1185 orig_start, orig_blocks,
1186 orig_inode->i_ino, donor_inode->i_ino);
1190 if (orig_start + *len > orig_blocks) {
1191 ext4_debug("ext4 move extent: Adjust length "
1192 "from %llu to %llu. Because it should be "
1193 "less than original file blocks "
1194 "[ino:orig %lu, donor %lu]\n",
1195 *len, orig_blocks - orig_start,
1196 orig_inode->i_ino, donor_inode->i_ino);
1197 *len = orig_blocks - orig_start;
1202 ext4_debug("ext4 move extent: len should not be 0 "
1203 "[ino:orig %lu, donor %lu]\n", orig_inode->i_ino,
1204 donor_inode->i_ino);
1212 * mext_inode_double_lock - Lock i_mutex on both @inode1 and @inode2
1214 * @inode1: the inode structure
1215 * @inode2: the inode structure
1217 * Lock two inodes' i_mutex
1220 mext_inode_double_lock(struct inode *inode1, struct inode *inode2)
1222 BUG_ON(inode1 == inode2);
1223 if (inode1 < inode2) {
1224 mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT);
1225 mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD);
1227 mutex_lock_nested(&inode2->i_mutex, I_MUTEX_PARENT);
1228 mutex_lock_nested(&inode1->i_mutex, I_MUTEX_CHILD);
1233 * mext_inode_double_unlock - Release i_mutex on both @inode1 and @inode2
1235 * @inode1: the inode that is released first
1236 * @inode2: the inode that is released second
1241 mext_inode_double_unlock(struct inode *inode1, struct inode *inode2)
1243 mutex_unlock(&inode1->i_mutex);
1244 mutex_unlock(&inode2->i_mutex);
1248 * ext4_move_extents - Exchange the specified range of a file
1250 * @o_filp: file structure of the original file
1251 * @d_filp: file structure of the donor file
1252 * @orig_start: start offset in block for orig
1253 * @donor_start: start offset in block for donor
1254 * @len: the number of blocks to be moved
1255 * @moved_len: moved block length
1257 * This function returns 0 and moved block length is set in moved_len
1258 * if succeed, otherwise returns error value.
1260 * Note: ext4_move_extents() proceeds the following order.
1261 * 1:ext4_move_extents() calculates the last block number of moving extent
1262 * function by the start block number (orig_start) and the number of blocks
1263 * to be moved (len) specified as arguments.
1264 * If the {orig, donor}_start points a hole, the extent's start offset
1265 * pointed by ext_cur (current extent), holecheck_path, orig_path are set
1266 * after hole behind.
1267 * 2:Continue step 3 to step 5, until the holecheck_path points to last_extent
1268 * or the ext_cur exceeds the block_end which is last logical block number.
1269 * 3:To get the length of continues area, call mext_next_extent()
1270 * specified with the ext_cur (initial value is holecheck_path) re-cursive,
1271 * until find un-continuous extent, the start logical block number exceeds
1272 * the block_end or the extent points to the last extent.
1273 * 4:Exchange the original inode data with donor inode data
1274 * from orig_page_offset to seq_end_page.
1275 * The start indexes of data are specified as arguments.
1276 * That of the original inode is orig_page_offset,
1277 * and the donor inode is also orig_page_offset
1278 * (To easily handle blocksize != pagesize case, the offset for the
1279 * donor inode is block unit).
1280 * 5:Update holecheck_path and orig_path to points a next proceeding extent,
1281 * then returns to step 2.
1282 * 6:Release holecheck_path, orig_path and set the len to moved_len
1283 * which shows the number of moved blocks.
1284 * The moved_len is useful for the command to calculate the file offset
1285 * for starting next move extent ioctl.
1286 * 7:Return 0 on success, or a negative error value on failure.
1289 ext4_move_extents(struct file *o_filp, struct file *d_filp,
1290 __u64 orig_start, __u64 donor_start, __u64 len,
1293 struct inode *orig_inode = file_inode(o_filp);
1294 struct inode *donor_inode = file_inode(d_filp);
1295 struct ext4_ext_path *orig_path = NULL, *holecheck_path = NULL;
1296 struct ext4_extent *ext_prev, *ext_cur, *ext_dummy;
1297 ext4_lblk_t block_start = orig_start;
1298 ext4_lblk_t block_end, seq_start, add_blocks, file_end, seq_blocks = 0;
1299 ext4_lblk_t rest_blocks;
1300 pgoff_t orig_page_offset = 0, seq_end_page;
1301 int ret, depth, last_extent = 0;
1302 int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits;
1303 int data_offset_in_page;
1304 int block_len_in_page;
1307 if (orig_inode->i_sb != donor_inode->i_sb) {
1308 ext4_debug("ext4 move extent: The argument files "
1309 "should be in same FS [ino:orig %lu, donor %lu]\n",
1310 orig_inode->i_ino, donor_inode->i_ino);
1314 /* orig and donor should be different inodes */
1315 if (orig_inode == donor_inode) {
1316 ext4_debug("ext4 move extent: The argument files should not "
1317 "be same inode [ino:orig %lu, donor %lu]\n",
1318 orig_inode->i_ino, donor_inode->i_ino);
1322 /* Regular file check */
1323 if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) {
1324 ext4_debug("ext4 move extent: The argument files should be "
1325 "regular file [ino:orig %lu, donor %lu]\n",
1326 orig_inode->i_ino, donor_inode->i_ino);
1329 /* TODO: This is non obvious task to swap blocks for inodes with full
1330 jornaling enabled */
1331 if (ext4_should_journal_data(orig_inode) ||
1332 ext4_should_journal_data(donor_inode)) {
1335 /* Protect orig and donor inodes against a truncate */
1336 mext_inode_double_lock(orig_inode, donor_inode);
1338 /* Wait for all existing dio workers */
1339 ext4_inode_block_unlocked_dio(orig_inode);
1340 ext4_inode_block_unlocked_dio(donor_inode);
1341 inode_dio_wait(orig_inode);
1342 inode_dio_wait(donor_inode);
1344 /* Protect extent tree against block allocations via delalloc */
1345 double_down_write_data_sem(orig_inode, donor_inode);
1346 /* Check the filesystem environment whether move_extent can be done */
1347 ret = mext_check_arguments(orig_inode, donor_inode, orig_start,
1352 file_end = (i_size_read(orig_inode) - 1) >> orig_inode->i_blkbits;
1353 block_end = block_start + len - 1;
1354 if (file_end < block_end)
1355 len -= block_end - file_end;
1357 ret = get_ext_path(orig_inode, block_start, &orig_path);
1361 /* Get path structure to check the hole */
1362 ret = get_ext_path(orig_inode, block_start, &holecheck_path);
1366 depth = ext_depth(orig_inode);
1367 ext_cur = holecheck_path[depth].p_ext;
1370 * Get proper starting location of block replacement if block_start was
1373 if (le32_to_cpu(ext_cur->ee_block) +
1374 ext4_ext_get_actual_len(ext_cur) - 1 < block_start) {
1376 * The hole exists between extents or the tail of
1379 last_extent = mext_next_extent(orig_inode,
1380 holecheck_path, &ext_cur);
1381 if (last_extent < 0) {
1385 last_extent = mext_next_extent(orig_inode, orig_path,
1387 if (last_extent < 0) {
1391 seq_start = le32_to_cpu(ext_cur->ee_block);
1392 } else if (le32_to_cpu(ext_cur->ee_block) > block_start)
1393 /* The hole exists at the beginning of original file. */
1394 seq_start = le32_to_cpu(ext_cur->ee_block);
1396 seq_start = block_start;
1398 /* No blocks within the specified range. */
1399 if (le32_to_cpu(ext_cur->ee_block) > block_end) {
1400 ext4_debug("ext4 move extent: The specified range of file "
1401 "may be the hole\n");
1406 /* Adjust start blocks */
1407 add_blocks = min(le32_to_cpu(ext_cur->ee_block) +
1408 ext4_ext_get_actual_len(ext_cur), block_end + 1) -
1409 max(le32_to_cpu(ext_cur->ee_block), block_start);
1411 while (!last_extent && le32_to_cpu(ext_cur->ee_block) <= block_end) {
1412 seq_blocks += add_blocks;
1414 /* Adjust tail blocks */
1415 if (seq_start + seq_blocks - 1 > block_end)
1416 seq_blocks = block_end - seq_start + 1;
1419 last_extent = mext_next_extent(orig_inode, holecheck_path,
1421 if (last_extent < 0) {
1425 add_blocks = ext4_ext_get_actual_len(ext_cur);
1428 * Extend the length of contiguous block (seq_blocks)
1429 * if extents are contiguous.
1431 if (ext4_can_extents_be_merged(orig_inode,
1432 ext_prev, ext_cur) &&
1433 block_end >= le32_to_cpu(ext_cur->ee_block) &&
1437 /* Is original extent is uninitialized */
1438 uninit = ext4_ext_is_uninitialized(ext_prev);
1440 data_offset_in_page = seq_start % blocks_per_page;
1443 * Calculate data blocks count that should be swapped
1444 * at the first page.
1446 if (data_offset_in_page + seq_blocks > blocks_per_page) {
1447 /* Swapped blocks are across pages */
1449 blocks_per_page - data_offset_in_page;
1451 /* Swapped blocks are in a page */
1452 block_len_in_page = seq_blocks;
1455 orig_page_offset = seq_start >>
1456 (PAGE_CACHE_SHIFT - orig_inode->i_blkbits);
1457 seq_end_page = (seq_start + seq_blocks - 1) >>
1458 (PAGE_CACHE_SHIFT - orig_inode->i_blkbits);
1459 seq_start = le32_to_cpu(ext_cur->ee_block);
1460 rest_blocks = seq_blocks;
1463 * Up semaphore to avoid following problems:
1464 * a. transaction deadlock among ext4_journal_start,
1465 * ->write_begin via pagefault, and jbd2_journal_commit
1466 * b. racing with ->readpage, ->write_begin, and ext4_get_block
1467 * in move_extent_per_page
1469 double_up_write_data_sem(orig_inode, donor_inode);
1471 while (orig_page_offset <= seq_end_page) {
1473 /* Swap original branches with new branches */
1474 block_len_in_page = move_extent_per_page(
1475 o_filp, donor_inode,
1477 data_offset_in_page,
1478 block_len_in_page, uninit,
1481 /* Count how many blocks we have exchanged */
1482 *moved_len += block_len_in_page;
1485 if (*moved_len > len) {
1486 EXT4_ERROR_INODE(orig_inode,
1487 "We replaced blocks too much! "
1488 "sum of replaced: %llu requested: %llu",
1495 data_offset_in_page = 0;
1496 rest_blocks -= block_len_in_page;
1497 if (rest_blocks > blocks_per_page)
1498 block_len_in_page = blocks_per_page;
1500 block_len_in_page = rest_blocks;
1503 double_down_write_data_sem(orig_inode, donor_inode);
1507 /* Decrease buffer counter */
1509 ext4_ext_drop_refs(holecheck_path);
1510 ret = get_ext_path(orig_inode, seq_start, &holecheck_path);
1513 depth = holecheck_path->p_depth;
1515 /* Decrease buffer counter */
1517 ext4_ext_drop_refs(orig_path);
1518 ret = get_ext_path(orig_inode, seq_start, &orig_path);
1522 ext_cur = holecheck_path[depth].p_ext;
1523 add_blocks = ext4_ext_get_actual_len(ext_cur);
1529 ext4_discard_preallocations(orig_inode);
1530 ext4_discard_preallocations(donor_inode);
1534 ext4_ext_drop_refs(orig_path);
1537 if (holecheck_path) {
1538 ext4_ext_drop_refs(holecheck_path);
1539 kfree(holecheck_path);
1541 double_up_write_data_sem(orig_inode, donor_inode);
1542 ext4_inode_resume_unlocked_dio(orig_inode);
1543 ext4_inode_resume_unlocked_dio(donor_inode);
1544 mext_inode_double_unlock(orig_inode, donor_inode);