1 // SPDX-License-Identifier: GPL-2.0
3 * linux/fs/ext4/inode.c
5 * Copyright (C) 1992, 1993, 1994, 1995
6 * Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
12 * linux/fs/minix/inode.c
14 * Copyright (C) 1991, 1992 Linus Torvalds
16 * 64-bit file support on 64-bit platforms by Jakub Jelinek
17 * (jj@sunsite.ms.mff.cuni.cz)
19 * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
23 #include <linux/time.h>
24 #include <linux/highuid.h>
25 #include <linux/pagemap.h>
26 #include <linux/dax.h>
27 #include <linux/quotaops.h>
28 #include <linux/string.h>
29 #include <linux/buffer_head.h>
30 #include <linux/writeback.h>
31 #include <linux/pagevec.h>
32 #include <linux/mpage.h>
33 #include <linux/namei.h>
34 #include <linux/uio.h>
35 #include <linux/bio.h>
36 #include <linux/workqueue.h>
37 #include <linux/kernel.h>
38 #include <linux/printk.h>
39 #include <linux/slab.h>
40 #include <linux/bitops.h>
41 #include <linux/iomap.h>
42 #include <linux/iversion.h>
44 #include "ext4_jbd2.h"
49 #include <trace/events/ext4.h>
51 #define MPAGE_DA_EXTENT_TAIL 0x01
53 static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw,
54 struct ext4_inode_info *ei)
56 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
59 int offset = offsetof(struct ext4_inode, i_checksum_lo);
60 unsigned int csum_size = sizeof(dummy_csum);
62 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)raw, offset);
63 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, csum_size);
65 csum = ext4_chksum(sbi, csum, (__u8 *)raw + offset,
66 EXT4_GOOD_OLD_INODE_SIZE - offset);
68 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
69 offset = offsetof(struct ext4_inode, i_checksum_hi);
70 csum = ext4_chksum(sbi, csum, (__u8 *)raw +
71 EXT4_GOOD_OLD_INODE_SIZE,
72 offset - EXT4_GOOD_OLD_INODE_SIZE);
73 if (EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) {
74 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum,
78 csum = ext4_chksum(sbi, csum, (__u8 *)raw + offset,
79 EXT4_INODE_SIZE(inode->i_sb) - offset);
85 static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw,
86 struct ext4_inode_info *ei)
88 __u32 provided, calculated;
90 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
91 cpu_to_le32(EXT4_OS_LINUX) ||
92 !ext4_has_metadata_csum(inode->i_sb))
95 provided = le16_to_cpu(raw->i_checksum_lo);
96 calculated = ext4_inode_csum(inode, raw, ei);
97 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
98 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
99 provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16;
101 calculated &= 0xFFFF;
103 return provided == calculated;
106 static void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw,
107 struct ext4_inode_info *ei)
111 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
112 cpu_to_le32(EXT4_OS_LINUX) ||
113 !ext4_has_metadata_csum(inode->i_sb))
116 csum = ext4_inode_csum(inode, raw, ei);
117 raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF);
118 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
119 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
120 raw->i_checksum_hi = cpu_to_le16(csum >> 16);
123 static inline int ext4_begin_ordered_truncate(struct inode *inode,
126 trace_ext4_begin_ordered_truncate(inode, new_size);
128 * If jinode is zero, then we never opened the file for
129 * writing, so there's no need to call
130 * jbd2_journal_begin_ordered_truncate() since there's no
131 * outstanding writes we need to flush.
133 if (!EXT4_I(inode)->jinode)
135 return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode),
136 EXT4_I(inode)->jinode,
140 static void ext4_invalidatepage(struct page *page, unsigned int offset,
141 unsigned int length);
142 static int __ext4_journalled_writepage(struct page *page, unsigned int len);
143 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
144 static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
148 * Test whether an inode is a fast symlink.
149 * A fast symlink has its symlink data stored in ext4_inode_info->i_data.
151 int ext4_inode_is_fast_symlink(struct inode *inode)
153 if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) {
154 int ea_blocks = EXT4_I(inode)->i_file_acl ?
155 EXT4_CLUSTER_SIZE(inode->i_sb) >> 9 : 0;
157 if (ext4_has_inline_data(inode))
160 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
162 return S_ISLNK(inode->i_mode) && inode->i_size &&
163 (inode->i_size < EXT4_N_BLOCKS * 4);
167 * Restart the transaction associated with *handle. This does a commit,
168 * so before we call here everything must be consistently dirtied against
171 int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
177 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
178 * moment, get_block can be called only for blocks inside i_size since
179 * page cache has been already dropped and writes are blocked by
180 * i_mutex. So we can safely drop the i_data_sem here.
182 BUG_ON(EXT4_JOURNAL(inode) == NULL);
183 jbd_debug(2, "restarting handle %p\n", handle);
184 up_write(&EXT4_I(inode)->i_data_sem);
185 ret = ext4_journal_restart(handle, nblocks);
186 down_write(&EXT4_I(inode)->i_data_sem);
187 ext4_discard_preallocations(inode);
193 * Called at the last iput() if i_nlink is zero.
195 void ext4_evict_inode(struct inode *inode)
199 int extra_credits = 3;
200 struct ext4_xattr_inode_array *ea_inode_array = NULL;
202 trace_ext4_evict_inode(inode);
204 if (inode->i_nlink) {
206 * When journalling data dirty buffers are tracked only in the
207 * journal. So although mm thinks everything is clean and
208 * ready for reaping the inode might still have some pages to
209 * write in the running transaction or waiting to be
210 * checkpointed. Thus calling jbd2_journal_invalidatepage()
211 * (via truncate_inode_pages()) to discard these buffers can
212 * cause data loss. Also even if we did not discard these
213 * buffers, we would have no way to find them after the inode
214 * is reaped and thus user could see stale data if he tries to
215 * read them before the transaction is checkpointed. So be
216 * careful and force everything to disk here... We use
217 * ei->i_datasync_tid to store the newest transaction
218 * containing inode's data.
220 * Note that directories do not have this problem because they
221 * don't use page cache.
223 if (inode->i_ino != EXT4_JOURNAL_INO &&
224 ext4_should_journal_data(inode) &&
225 (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode)) &&
226 inode->i_data.nrpages) {
227 journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
228 tid_t commit_tid = EXT4_I(inode)->i_datasync_tid;
230 jbd2_complete_transaction(journal, commit_tid);
231 filemap_write_and_wait(&inode->i_data);
233 truncate_inode_pages_final(&inode->i_data);
238 if (is_bad_inode(inode))
240 dquot_initialize(inode);
242 if (ext4_should_order_data(inode))
243 ext4_begin_ordered_truncate(inode, 0);
244 truncate_inode_pages_final(&inode->i_data);
247 * Protect us against freezing - iput() caller didn't have to have any
248 * protection against it
250 sb_start_intwrite(inode->i_sb);
252 if (!IS_NOQUOTA(inode))
253 extra_credits += EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb);
255 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE,
256 ext4_blocks_for_truncate(inode)+extra_credits);
257 if (IS_ERR(handle)) {
258 ext4_std_error(inode->i_sb, PTR_ERR(handle));
260 * If we're going to skip the normal cleanup, we still need to
261 * make sure that the in-core orphan linked list is properly
264 ext4_orphan_del(NULL, inode);
265 sb_end_intwrite(inode->i_sb);
270 ext4_handle_sync(handle);
273 * Set inode->i_size to 0 before calling ext4_truncate(). We need
274 * special handling of symlinks here because i_size is used to
275 * determine whether ext4_inode_info->i_data contains symlink data or
276 * block mappings. Setting i_size to 0 will remove its fast symlink
277 * status. Erase i_data so that it becomes a valid empty block map.
279 if (ext4_inode_is_fast_symlink(inode))
280 memset(EXT4_I(inode)->i_data, 0, sizeof(EXT4_I(inode)->i_data));
282 err = ext4_mark_inode_dirty(handle, inode);
284 ext4_warning(inode->i_sb,
285 "couldn't mark inode dirty (err %d)", err);
288 if (inode->i_blocks) {
289 err = ext4_truncate(inode);
291 ext4_error(inode->i_sb,
292 "couldn't truncate inode %lu (err %d)",
298 /* Remove xattr references. */
299 err = ext4_xattr_delete_inode(handle, inode, &ea_inode_array,
302 ext4_warning(inode->i_sb, "xattr delete (err %d)", err);
304 ext4_journal_stop(handle);
305 ext4_orphan_del(NULL, inode);
306 sb_end_intwrite(inode->i_sb);
307 ext4_xattr_inode_array_free(ea_inode_array);
312 * Kill off the orphan record which ext4_truncate created.
313 * AKPM: I think this can be inside the above `if'.
314 * Note that ext4_orphan_del() has to be able to cope with the
315 * deletion of a non-existent orphan - this is because we don't
316 * know if ext4_truncate() actually created an orphan record.
317 * (Well, we could do this if we need to, but heck - it works)
319 ext4_orphan_del(handle, inode);
320 EXT4_I(inode)->i_dtime = get_seconds();
323 * One subtle ordering requirement: if anything has gone wrong
324 * (transaction abort, IO errors, whatever), then we can still
325 * do these next steps (the fs will already have been marked as
326 * having errors), but we can't free the inode if the mark_dirty
329 if (ext4_mark_inode_dirty(handle, inode))
330 /* If that failed, just do the required in-core inode clear. */
331 ext4_clear_inode(inode);
333 ext4_free_inode(handle, inode);
334 ext4_journal_stop(handle);
335 sb_end_intwrite(inode->i_sb);
336 ext4_xattr_inode_array_free(ea_inode_array);
339 ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
343 qsize_t *ext4_get_reserved_space(struct inode *inode)
345 return &EXT4_I(inode)->i_reserved_quota;
350 * Called with i_data_sem down, which is important since we can call
351 * ext4_discard_preallocations() from here.
353 void ext4_da_update_reserve_space(struct inode *inode,
354 int used, int quota_claim)
356 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
357 struct ext4_inode_info *ei = EXT4_I(inode);
359 spin_lock(&ei->i_block_reservation_lock);
360 trace_ext4_da_update_reserve_space(inode, used, quota_claim);
361 if (unlikely(used > ei->i_reserved_data_blocks)) {
362 ext4_warning(inode->i_sb, "%s: ino %lu, used %d "
363 "with only %d reserved data blocks",
364 __func__, inode->i_ino, used,
365 ei->i_reserved_data_blocks);
367 used = ei->i_reserved_data_blocks;
370 /* Update per-inode reservations */
371 ei->i_reserved_data_blocks -= used;
372 percpu_counter_sub(&sbi->s_dirtyclusters_counter, used);
374 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
376 /* Update quota subsystem for data blocks */
378 dquot_claim_block(inode, EXT4_C2B(sbi, used));
381 * We did fallocate with an offset that is already delayed
382 * allocated. So on delayed allocated writeback we should
383 * not re-claim the quota for fallocated blocks.
385 dquot_release_reservation_block(inode, EXT4_C2B(sbi, used));
389 * If we have done all the pending block allocations and if
390 * there aren't any writers on the inode, we can discard the
391 * inode's preallocations.
393 if ((ei->i_reserved_data_blocks == 0) &&
394 (atomic_read(&inode->i_writecount) == 0))
395 ext4_discard_preallocations(inode);
398 static int __check_block_validity(struct inode *inode, const char *func,
400 struct ext4_map_blocks *map)
402 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
404 ext4_error_inode(inode, func, line, map->m_pblk,
405 "lblock %lu mapped to illegal pblock "
406 "(length %d)", (unsigned long) map->m_lblk,
408 return -EFSCORRUPTED;
413 int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk, ext4_fsblk_t pblk,
418 if (ext4_encrypted_inode(inode))
419 return fscrypt_zeroout_range(inode, lblk, pblk, len);
421 ret = sb_issue_zeroout(inode->i_sb, pblk, len, GFP_NOFS);
428 #define check_block_validity(inode, map) \
429 __check_block_validity((inode), __func__, __LINE__, (map))
431 #ifdef ES_AGGRESSIVE_TEST
432 static void ext4_map_blocks_es_recheck(handle_t *handle,
434 struct ext4_map_blocks *es_map,
435 struct ext4_map_blocks *map,
442 * There is a race window that the result is not the same.
443 * e.g. xfstests #223 when dioread_nolock enables. The reason
444 * is that we lookup a block mapping in extent status tree with
445 * out taking i_data_sem. So at the time the unwritten extent
446 * could be converted.
448 down_read(&EXT4_I(inode)->i_data_sem);
449 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
450 retval = ext4_ext_map_blocks(handle, inode, map, flags &
451 EXT4_GET_BLOCKS_KEEP_SIZE);
453 retval = ext4_ind_map_blocks(handle, inode, map, flags &
454 EXT4_GET_BLOCKS_KEEP_SIZE);
456 up_read((&EXT4_I(inode)->i_data_sem));
459 * We don't check m_len because extent will be collpased in status
460 * tree. So the m_len might not equal.
462 if (es_map->m_lblk != map->m_lblk ||
463 es_map->m_flags != map->m_flags ||
464 es_map->m_pblk != map->m_pblk) {
465 printk("ES cache assertion failed for inode: %lu "
466 "es_cached ex [%d/%d/%llu/%x] != "
467 "found ex [%d/%d/%llu/%x] retval %d flags %x\n",
468 inode->i_ino, es_map->m_lblk, es_map->m_len,
469 es_map->m_pblk, es_map->m_flags, map->m_lblk,
470 map->m_len, map->m_pblk, map->m_flags,
474 #endif /* ES_AGGRESSIVE_TEST */
477 * The ext4_map_blocks() function tries to look up the requested blocks,
478 * and returns if the blocks are already mapped.
480 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
481 * and store the allocated blocks in the result buffer head and mark it
484 * If file type is extents based, it will call ext4_ext_map_blocks(),
485 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
488 * On success, it returns the number of blocks being mapped or allocated. if
489 * create==0 and the blocks are pre-allocated and unwritten, the resulting @map
490 * is marked as unwritten. If the create == 1, it will mark @map as mapped.
492 * It returns 0 if plain look up failed (blocks have not been allocated), in
493 * that case, @map is returned as unmapped but we still do fill map->m_len to
494 * indicate the length of a hole starting at map->m_lblk.
496 * It returns the error in case of allocation failure.
498 int ext4_map_blocks(handle_t *handle, struct inode *inode,
499 struct ext4_map_blocks *map, int flags)
501 struct extent_status es;
504 #ifdef ES_AGGRESSIVE_TEST
505 struct ext4_map_blocks orig_map;
507 memcpy(&orig_map, map, sizeof(*map));
511 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
512 "logical block %lu\n", inode->i_ino, flags, map->m_len,
513 (unsigned long) map->m_lblk);
516 * ext4_map_blocks returns an int, and m_len is an unsigned int
518 if (unlikely(map->m_len > INT_MAX))
519 map->m_len = INT_MAX;
521 /* We can handle the block number less than EXT_MAX_BLOCKS */
522 if (unlikely(map->m_lblk >= EXT_MAX_BLOCKS))
523 return -EFSCORRUPTED;
525 /* Lookup extent status tree firstly */
526 if (ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
527 if (ext4_es_is_written(&es) || ext4_es_is_unwritten(&es)) {
528 map->m_pblk = ext4_es_pblock(&es) +
529 map->m_lblk - es.es_lblk;
530 map->m_flags |= ext4_es_is_written(&es) ?
531 EXT4_MAP_MAPPED : EXT4_MAP_UNWRITTEN;
532 retval = es.es_len - (map->m_lblk - es.es_lblk);
533 if (retval > map->m_len)
536 } else if (ext4_es_is_delayed(&es) || ext4_es_is_hole(&es)) {
538 retval = es.es_len - (map->m_lblk - es.es_lblk);
539 if (retval > map->m_len)
546 #ifdef ES_AGGRESSIVE_TEST
547 ext4_map_blocks_es_recheck(handle, inode, map,
554 * Try to see if we can get the block without requesting a new
557 down_read(&EXT4_I(inode)->i_data_sem);
558 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
559 retval = ext4_ext_map_blocks(handle, inode, map, flags &
560 EXT4_GET_BLOCKS_KEEP_SIZE);
562 retval = ext4_ind_map_blocks(handle, inode, map, flags &
563 EXT4_GET_BLOCKS_KEEP_SIZE);
568 if (unlikely(retval != map->m_len)) {
569 ext4_warning(inode->i_sb,
570 "ES len assertion failed for inode "
571 "%lu: retval %d != map->m_len %d",
572 inode->i_ino, retval, map->m_len);
576 status = map->m_flags & EXT4_MAP_UNWRITTEN ?
577 EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
578 if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
579 !(status & EXTENT_STATUS_WRITTEN) &&
580 ext4_find_delalloc_range(inode, map->m_lblk,
581 map->m_lblk + map->m_len - 1))
582 status |= EXTENT_STATUS_DELAYED;
583 ret = ext4_es_insert_extent(inode, map->m_lblk,
584 map->m_len, map->m_pblk, status);
588 up_read((&EXT4_I(inode)->i_data_sem));
591 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
592 ret = check_block_validity(inode, map);
597 /* If it is only a block(s) look up */
598 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
602 * Returns if the blocks have already allocated
604 * Note that if blocks have been preallocated
605 * ext4_ext_get_block() returns the create = 0
606 * with buffer head unmapped.
608 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
610 * If we need to convert extent to unwritten
611 * we continue and do the actual work in
612 * ext4_ext_map_blocks()
614 if (!(flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN))
618 * Here we clear m_flags because after allocating an new extent,
619 * it will be set again.
621 map->m_flags &= ~EXT4_MAP_FLAGS;
624 * New blocks allocate and/or writing to unwritten extent
625 * will possibly result in updating i_data, so we take
626 * the write lock of i_data_sem, and call get_block()
627 * with create == 1 flag.
629 down_write(&EXT4_I(inode)->i_data_sem);
632 * We need to check for EXT4 here because migrate
633 * could have changed the inode type in between
635 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
636 retval = ext4_ext_map_blocks(handle, inode, map, flags);
638 retval = ext4_ind_map_blocks(handle, inode, map, flags);
640 if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
642 * We allocated new blocks which will result in
643 * i_data's format changing. Force the migrate
644 * to fail by clearing migrate flags
646 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
650 * Update reserved blocks/metadata blocks after successful
651 * block allocation which had been deferred till now. We don't
652 * support fallocate for non extent files. So we can update
653 * reserve space here.
656 (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
657 ext4_da_update_reserve_space(inode, retval, 1);
663 if (unlikely(retval != map->m_len)) {
664 ext4_warning(inode->i_sb,
665 "ES len assertion failed for inode "
666 "%lu: retval %d != map->m_len %d",
667 inode->i_ino, retval, map->m_len);
672 * We have to zeroout blocks before inserting them into extent
673 * status tree. Otherwise someone could look them up there and
674 * use them before they are really zeroed. We also have to
675 * unmap metadata before zeroing as otherwise writeback can
676 * overwrite zeros with stale data from block device.
678 if (flags & EXT4_GET_BLOCKS_ZERO &&
679 map->m_flags & EXT4_MAP_MAPPED &&
680 map->m_flags & EXT4_MAP_NEW) {
681 clean_bdev_aliases(inode->i_sb->s_bdev, map->m_pblk,
683 ret = ext4_issue_zeroout(inode, map->m_lblk,
684 map->m_pblk, map->m_len);
692 * If the extent has been zeroed out, we don't need to update
693 * extent status tree.
695 if ((flags & EXT4_GET_BLOCKS_PRE_IO) &&
696 ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
697 if (ext4_es_is_written(&es))
700 status = map->m_flags & EXT4_MAP_UNWRITTEN ?
701 EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
702 if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
703 !(status & EXTENT_STATUS_WRITTEN) &&
704 ext4_find_delalloc_range(inode, map->m_lblk,
705 map->m_lblk + map->m_len - 1))
706 status |= EXTENT_STATUS_DELAYED;
707 ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
708 map->m_pblk, status);
716 up_write((&EXT4_I(inode)->i_data_sem));
717 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
718 ret = check_block_validity(inode, map);
723 * Inodes with freshly allocated blocks where contents will be
724 * visible after transaction commit must be on transaction's
727 if (map->m_flags & EXT4_MAP_NEW &&
728 !(map->m_flags & EXT4_MAP_UNWRITTEN) &&
729 !(flags & EXT4_GET_BLOCKS_ZERO) &&
730 !ext4_is_quota_file(inode) &&
731 ext4_should_order_data(inode)) {
732 if (flags & EXT4_GET_BLOCKS_IO_SUBMIT)
733 ret = ext4_jbd2_inode_add_wait(handle, inode);
735 ret = ext4_jbd2_inode_add_write(handle, inode);
744 * Update EXT4_MAP_FLAGS in bh->b_state. For buffer heads attached to pages
745 * we have to be careful as someone else may be manipulating b_state as well.
747 static void ext4_update_bh_state(struct buffer_head *bh, unsigned long flags)
749 unsigned long old_state;
750 unsigned long new_state;
752 flags &= EXT4_MAP_FLAGS;
754 /* Dummy buffer_head? Set non-atomically. */
756 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | flags;
760 * Someone else may be modifying b_state. Be careful! This is ugly but
761 * once we get rid of using bh as a container for mapping information
762 * to pass to / from get_block functions, this can go away.
765 old_state = READ_ONCE(bh->b_state);
766 new_state = (old_state & ~EXT4_MAP_FLAGS) | flags;
768 cmpxchg(&bh->b_state, old_state, new_state) != old_state));
771 static int _ext4_get_block(struct inode *inode, sector_t iblock,
772 struct buffer_head *bh, int flags)
774 struct ext4_map_blocks map;
777 if (ext4_has_inline_data(inode))
781 map.m_len = bh->b_size >> inode->i_blkbits;
783 ret = ext4_map_blocks(ext4_journal_current_handle(), inode, &map,
786 map_bh(bh, inode->i_sb, map.m_pblk);
787 ext4_update_bh_state(bh, map.m_flags);
788 bh->b_size = inode->i_sb->s_blocksize * map.m_len;
790 } else if (ret == 0) {
791 /* hole case, need to fill in bh->b_size */
792 bh->b_size = inode->i_sb->s_blocksize * map.m_len;
797 int ext4_get_block(struct inode *inode, sector_t iblock,
798 struct buffer_head *bh, int create)
800 return _ext4_get_block(inode, iblock, bh,
801 create ? EXT4_GET_BLOCKS_CREATE : 0);
805 * Get block function used when preparing for buffered write if we require
806 * creating an unwritten extent if blocks haven't been allocated. The extent
807 * will be converted to written after the IO is complete.
809 int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
810 struct buffer_head *bh_result, int create)
812 ext4_debug("ext4_get_block_unwritten: inode %lu, create flag %d\n",
813 inode->i_ino, create);
814 return _ext4_get_block(inode, iblock, bh_result,
815 EXT4_GET_BLOCKS_IO_CREATE_EXT);
818 /* Maximum number of blocks we map for direct IO at once. */
819 #define DIO_MAX_BLOCKS 4096
822 * Get blocks function for the cases that need to start a transaction -
823 * generally difference cases of direct IO and DAX IO. It also handles retries
826 static int ext4_get_block_trans(struct inode *inode, sector_t iblock,
827 struct buffer_head *bh_result, int flags)
834 /* Trim mapping request to maximum we can map at once for DIO */
835 if (bh_result->b_size >> inode->i_blkbits > DIO_MAX_BLOCKS)
836 bh_result->b_size = DIO_MAX_BLOCKS << inode->i_blkbits;
837 dio_credits = ext4_chunk_trans_blocks(inode,
838 bh_result->b_size >> inode->i_blkbits);
840 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits);
842 return PTR_ERR(handle);
844 ret = _ext4_get_block(inode, iblock, bh_result, flags);
845 ext4_journal_stop(handle);
847 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
852 /* Get block function for DIO reads and writes to inodes without extents */
853 int ext4_dio_get_block(struct inode *inode, sector_t iblock,
854 struct buffer_head *bh, int create)
856 /* We don't expect handle for direct IO */
857 WARN_ON_ONCE(ext4_journal_current_handle());
860 return _ext4_get_block(inode, iblock, bh, 0);
861 return ext4_get_block_trans(inode, iblock, bh, EXT4_GET_BLOCKS_CREATE);
865 * Get block function for AIO DIO writes when we create unwritten extent if
866 * blocks are not allocated yet. The extent will be converted to written
867 * after IO is complete.
869 static int ext4_dio_get_block_unwritten_async(struct inode *inode,
870 sector_t iblock, struct buffer_head *bh_result, int create)
874 /* We don't expect handle for direct IO */
875 WARN_ON_ONCE(ext4_journal_current_handle());
877 ret = ext4_get_block_trans(inode, iblock, bh_result,
878 EXT4_GET_BLOCKS_IO_CREATE_EXT);
881 * When doing DIO using unwritten extents, we need io_end to convert
882 * unwritten extents to written on IO completion. We allocate io_end
883 * once we spot unwritten extent and store it in b_private. Generic
884 * DIO code keeps b_private set and furthermore passes the value to
885 * our completion callback in 'private' argument.
887 if (!ret && buffer_unwritten(bh_result)) {
888 if (!bh_result->b_private) {
889 ext4_io_end_t *io_end;
891 io_end = ext4_init_io_end(inode, GFP_KERNEL);
894 bh_result->b_private = io_end;
895 ext4_set_io_unwritten_flag(inode, io_end);
897 set_buffer_defer_completion(bh_result);
904 * Get block function for non-AIO DIO writes when we create unwritten extent if
905 * blocks are not allocated yet. The extent will be converted to written
906 * after IO is complete by ext4_direct_IO_write().
908 static int ext4_dio_get_block_unwritten_sync(struct inode *inode,
909 sector_t iblock, struct buffer_head *bh_result, int create)
913 /* We don't expect handle for direct IO */
914 WARN_ON_ONCE(ext4_journal_current_handle());
916 ret = ext4_get_block_trans(inode, iblock, bh_result,
917 EXT4_GET_BLOCKS_IO_CREATE_EXT);
920 * Mark inode as having pending DIO writes to unwritten extents.
921 * ext4_direct_IO_write() checks this flag and converts extents to
924 if (!ret && buffer_unwritten(bh_result))
925 ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
930 static int ext4_dio_get_block_overwrite(struct inode *inode, sector_t iblock,
931 struct buffer_head *bh_result, int create)
935 ext4_debug("ext4_dio_get_block_overwrite: inode %lu, create flag %d\n",
936 inode->i_ino, create);
937 /* We don't expect handle for direct IO */
938 WARN_ON_ONCE(ext4_journal_current_handle());
940 ret = _ext4_get_block(inode, iblock, bh_result, 0);
942 * Blocks should have been preallocated! ext4_file_write_iter() checks
945 WARN_ON_ONCE(!buffer_mapped(bh_result) || buffer_unwritten(bh_result));
952 * `handle' can be NULL if create is zero
954 struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
955 ext4_lblk_t block, int map_flags)
957 struct ext4_map_blocks map;
958 struct buffer_head *bh;
959 int create = map_flags & EXT4_GET_BLOCKS_CREATE;
962 J_ASSERT(handle != NULL || create == 0);
966 err = ext4_map_blocks(handle, inode, &map, map_flags);
969 return create ? ERR_PTR(-ENOSPC) : NULL;
973 bh = sb_getblk(inode->i_sb, map.m_pblk);
975 return ERR_PTR(-ENOMEM);
976 if (map.m_flags & EXT4_MAP_NEW) {
977 J_ASSERT(create != 0);
978 J_ASSERT(handle != NULL);
981 * Now that we do not always journal data, we should
982 * keep in mind whether this should always journal the
983 * new buffer as metadata. For now, regular file
984 * writes use ext4_get_block instead, so it's not a
988 BUFFER_TRACE(bh, "call get_create_access");
989 err = ext4_journal_get_create_access(handle, bh);
994 if (!buffer_uptodate(bh)) {
995 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
996 set_buffer_uptodate(bh);
999 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1000 err = ext4_handle_dirty_metadata(handle, inode, bh);
1004 BUFFER_TRACE(bh, "not a new buffer");
1008 return ERR_PTR(err);
1011 struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
1012 ext4_lblk_t block, int map_flags)
1014 struct buffer_head *bh;
1016 bh = ext4_getblk(handle, inode, block, map_flags);
1019 if (!bh || buffer_uptodate(bh))
1021 ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &bh);
1023 if (buffer_uptodate(bh))
1026 return ERR_PTR(-EIO);
1029 /* Read a contiguous batch of blocks. */
1030 int ext4_bread_batch(struct inode *inode, ext4_lblk_t block, int bh_count,
1031 bool wait, struct buffer_head **bhs)
1035 for (i = 0; i < bh_count; i++) {
1036 bhs[i] = ext4_getblk(NULL, inode, block + i, 0 /* map_flags */);
1037 if (IS_ERR(bhs[i])) {
1038 err = PTR_ERR(bhs[i]);
1044 for (i = 0; i < bh_count; i++)
1045 /* Note that NULL bhs[i] is valid because of holes. */
1046 if (bhs[i] && !buffer_uptodate(bhs[i]))
1047 ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1,
1053 for (i = 0; i < bh_count; i++)
1055 wait_on_buffer(bhs[i]);
1057 for (i = 0; i < bh_count; i++) {
1058 if (bhs[i] && !buffer_uptodate(bhs[i])) {
1066 for (i = 0; i < bh_count; i++) {
1073 int ext4_walk_page_buffers(handle_t *handle,
1074 struct buffer_head *head,
1078 int (*fn)(handle_t *handle,
1079 struct buffer_head *bh))
1081 struct buffer_head *bh;
1082 unsigned block_start, block_end;
1083 unsigned blocksize = head->b_size;
1085 struct buffer_head *next;
1087 for (bh = head, block_start = 0;
1088 ret == 0 && (bh != head || !block_start);
1089 block_start = block_end, bh = next) {
1090 next = bh->b_this_page;
1091 block_end = block_start + blocksize;
1092 if (block_end <= from || block_start >= to) {
1093 if (partial && !buffer_uptodate(bh))
1097 err = (*fn)(handle, bh);
1105 * To preserve ordering, it is essential that the hole instantiation and
1106 * the data write be encapsulated in a single transaction. We cannot
1107 * close off a transaction and start a new one between the ext4_get_block()
1108 * and the commit_write(). So doing the jbd2_journal_start at the start of
1109 * prepare_write() is the right place.
1111 * Also, this function can nest inside ext4_writepage(). In that case, we
1112 * *know* that ext4_writepage() has generated enough buffer credits to do the
1113 * whole page. So we won't block on the journal in that case, which is good,
1114 * because the caller may be PF_MEMALLOC.
1116 * By accident, ext4 can be reentered when a transaction is open via
1117 * quota file writes. If we were to commit the transaction while thus
1118 * reentered, there can be a deadlock - we would be holding a quota
1119 * lock, and the commit would never complete if another thread had a
1120 * transaction open and was blocking on the quota lock - a ranking
1123 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1124 * will _not_ run commit under these circumstances because handle->h_ref
1125 * is elevated. We'll still have enough credits for the tiny quotafile
1128 int do_journal_get_write_access(handle_t *handle,
1129 struct buffer_head *bh)
1131 int dirty = buffer_dirty(bh);
1134 if (!buffer_mapped(bh) || buffer_freed(bh))
1137 * __block_write_begin() could have dirtied some buffers. Clean
1138 * the dirty bit as jbd2_journal_get_write_access() could complain
1139 * otherwise about fs integrity issues. Setting of the dirty bit
1140 * by __block_write_begin() isn't a real problem here as we clear
1141 * the bit before releasing a page lock and thus writeback cannot
1142 * ever write the buffer.
1145 clear_buffer_dirty(bh);
1146 BUFFER_TRACE(bh, "get write access");
1147 ret = ext4_journal_get_write_access(handle, bh);
1149 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
1153 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1154 static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
1155 get_block_t *get_block)
1157 unsigned from = pos & (PAGE_SIZE - 1);
1158 unsigned to = from + len;
1159 struct inode *inode = page->mapping->host;
1160 unsigned block_start, block_end;
1163 unsigned blocksize = inode->i_sb->s_blocksize;
1165 struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
1166 bool decrypt = false;
1168 BUG_ON(!PageLocked(page));
1169 BUG_ON(from > PAGE_SIZE);
1170 BUG_ON(to > PAGE_SIZE);
1173 if (!page_has_buffers(page))
1174 create_empty_buffers(page, blocksize, 0);
1175 head = page_buffers(page);
1176 bbits = ilog2(blocksize);
1177 block = (sector_t)page->index << (PAGE_SHIFT - bbits);
1179 for (bh = head, block_start = 0; bh != head || !block_start;
1180 block++, block_start = block_end, bh = bh->b_this_page) {
1181 block_end = block_start + blocksize;
1182 if (block_end <= from || block_start >= to) {
1183 if (PageUptodate(page)) {
1184 if (!buffer_uptodate(bh))
1185 set_buffer_uptodate(bh);
1190 clear_buffer_new(bh);
1191 if (!buffer_mapped(bh)) {
1192 WARN_ON(bh->b_size != blocksize);
1193 err = get_block(inode, block, bh, 1);
1196 if (buffer_new(bh)) {
1197 clean_bdev_bh_alias(bh);
1198 if (PageUptodate(page)) {
1199 clear_buffer_new(bh);
1200 set_buffer_uptodate(bh);
1201 mark_buffer_dirty(bh);
1204 if (block_end > to || block_start < from)
1205 zero_user_segments(page, to, block_end,
1210 if (PageUptodate(page)) {
1211 if (!buffer_uptodate(bh))
1212 set_buffer_uptodate(bh);
1215 if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
1216 !buffer_unwritten(bh) &&
1217 (block_start < from || block_end > to)) {
1218 ll_rw_block(REQ_OP_READ, 0, 1, &bh);
1220 decrypt = ext4_encrypted_inode(inode) &&
1221 S_ISREG(inode->i_mode);
1225 * If we issued read requests, let them complete.
1227 while (wait_bh > wait) {
1228 wait_on_buffer(*--wait_bh);
1229 if (!buffer_uptodate(*wait_bh))
1233 page_zero_new_buffers(page, from, to);
1235 err = fscrypt_decrypt_page(page->mapping->host, page,
1236 PAGE_SIZE, 0, page->index);
1241 static int ext4_write_begin(struct file *file, struct address_space *mapping,
1242 loff_t pos, unsigned len, unsigned flags,
1243 struct page **pagep, void **fsdata)
1245 struct inode *inode = mapping->host;
1246 int ret, needed_blocks;
1253 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
1256 trace_ext4_write_begin(inode, pos, len, flags);
1258 * Reserve one block more for addition to orphan list in case
1259 * we allocate blocks but write fails for some reason
1261 needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
1262 index = pos >> PAGE_SHIFT;
1263 from = pos & (PAGE_SIZE - 1);
1266 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
1267 ret = ext4_try_to_write_inline_data(mapping, inode, pos, len,
1276 * grab_cache_page_write_begin() can take a long time if the
1277 * system is thrashing due to memory pressure, or if the page
1278 * is being written back. So grab it first before we start
1279 * the transaction handle. This also allows us to allocate
1280 * the page (if needed) without using GFP_NOFS.
1283 page = grab_cache_page_write_begin(mapping, index, flags);
1289 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks);
1290 if (IS_ERR(handle)) {
1292 return PTR_ERR(handle);
1296 if (page->mapping != mapping) {
1297 /* The page got truncated from under us */
1300 ext4_journal_stop(handle);
1303 /* In case writeback began while the page was unlocked */
1304 wait_for_stable_page(page);
1306 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1307 if (ext4_should_dioread_nolock(inode))
1308 ret = ext4_block_write_begin(page, pos, len,
1309 ext4_get_block_unwritten);
1311 ret = ext4_block_write_begin(page, pos, len,
1314 if (ext4_should_dioread_nolock(inode))
1315 ret = __block_write_begin(page, pos, len,
1316 ext4_get_block_unwritten);
1318 ret = __block_write_begin(page, pos, len, ext4_get_block);
1320 if (!ret && ext4_should_journal_data(inode)) {
1321 ret = ext4_walk_page_buffers(handle, page_buffers(page),
1323 do_journal_get_write_access);
1329 * __block_write_begin may have instantiated a few blocks
1330 * outside i_size. Trim these off again. Don't need
1331 * i_size_read because we hold i_mutex.
1333 * Add inode to orphan list in case we crash before
1336 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1337 ext4_orphan_add(handle, inode);
1339 ext4_journal_stop(handle);
1340 if (pos + len > inode->i_size) {
1341 ext4_truncate_failed_write(inode);
1343 * If truncate failed early the inode might
1344 * still be on the orphan list; we need to
1345 * make sure the inode is removed from the
1346 * orphan list in that case.
1349 ext4_orphan_del(NULL, inode);
1352 if (ret == -ENOSPC &&
1353 ext4_should_retry_alloc(inode->i_sb, &retries))
1362 /* For write_end() in data=journal mode */
1363 static int write_end_fn(handle_t *handle, struct buffer_head *bh)
1366 if (!buffer_mapped(bh) || buffer_freed(bh))
1368 set_buffer_uptodate(bh);
1369 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
1370 clear_buffer_meta(bh);
1371 clear_buffer_prio(bh);
1376 * We need to pick up the new inode size which generic_commit_write gave us
1377 * `file' can be NULL - eg, when called from page_symlink().
1379 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1380 * buffers are managed internally.
1382 static int ext4_write_end(struct file *file,
1383 struct address_space *mapping,
1384 loff_t pos, unsigned len, unsigned copied,
1385 struct page *page, void *fsdata)
1387 handle_t *handle = ext4_journal_current_handle();
1388 struct inode *inode = mapping->host;
1389 loff_t old_size = inode->i_size;
1391 int i_size_changed = 0;
1393 trace_ext4_write_end(inode, pos, len, copied);
1394 if (ext4_has_inline_data(inode)) {
1395 ret = ext4_write_inline_data_end(inode, pos, len,
1404 copied = block_write_end(file, mapping, pos,
1405 len, copied, page, fsdata);
1407 * it's important to update i_size while still holding page lock:
1408 * page writeout could otherwise come in and zero beyond i_size.
1410 i_size_changed = ext4_update_inode_size(inode, pos + copied);
1415 pagecache_isize_extended(inode, old_size, pos);
1417 * Don't mark the inode dirty under page lock. First, it unnecessarily
1418 * makes the holding time of page lock longer. Second, it forces lock
1419 * ordering of page lock and transaction start for journaling
1423 ext4_mark_inode_dirty(handle, inode);
1425 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1426 /* if we have allocated more blocks and copied
1427 * less. We will have blocks allocated outside
1428 * inode->i_size. So truncate them
1430 ext4_orphan_add(handle, inode);
1432 ret2 = ext4_journal_stop(handle);
1436 if (pos + len > inode->i_size) {
1437 ext4_truncate_failed_write(inode);
1439 * If truncate failed early the inode might still be
1440 * on the orphan list; we need to make sure the inode
1441 * is removed from the orphan list in that case.
1444 ext4_orphan_del(NULL, inode);
1447 return ret ? ret : copied;
1451 * This is a private version of page_zero_new_buffers() which doesn't
1452 * set the buffer to be dirty, since in data=journalled mode we need
1453 * to call ext4_handle_dirty_metadata() instead.
1455 static void ext4_journalled_zero_new_buffers(handle_t *handle,
1457 unsigned from, unsigned to)
1459 unsigned int block_start = 0, block_end;
1460 struct buffer_head *head, *bh;
1462 bh = head = page_buffers(page);
1464 block_end = block_start + bh->b_size;
1465 if (buffer_new(bh)) {
1466 if (block_end > from && block_start < to) {
1467 if (!PageUptodate(page)) {
1468 unsigned start, size;
1470 start = max(from, block_start);
1471 size = min(to, block_end) - start;
1473 zero_user(page, start, size);
1474 write_end_fn(handle, bh);
1476 clear_buffer_new(bh);
1479 block_start = block_end;
1480 bh = bh->b_this_page;
1481 } while (bh != head);
1484 static int ext4_journalled_write_end(struct file *file,
1485 struct address_space *mapping,
1486 loff_t pos, unsigned len, unsigned copied,
1487 struct page *page, void *fsdata)
1489 handle_t *handle = ext4_journal_current_handle();
1490 struct inode *inode = mapping->host;
1491 loff_t old_size = inode->i_size;
1495 int size_changed = 0;
1497 trace_ext4_journalled_write_end(inode, pos, len, copied);
1498 from = pos & (PAGE_SIZE - 1);
1501 BUG_ON(!ext4_handle_valid(handle));
1503 if (ext4_has_inline_data(inode)) {
1504 ret = ext4_write_inline_data_end(inode, pos, len,
1512 } else if (unlikely(copied < len) && !PageUptodate(page)) {
1514 ext4_journalled_zero_new_buffers(handle, page, from, to);
1516 if (unlikely(copied < len))
1517 ext4_journalled_zero_new_buffers(handle, page,
1519 ret = ext4_walk_page_buffers(handle, page_buffers(page), from,
1520 from + copied, &partial,
1523 SetPageUptodate(page);
1525 size_changed = ext4_update_inode_size(inode, pos + copied);
1526 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1527 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1532 pagecache_isize_extended(inode, old_size, pos);
1535 ret2 = ext4_mark_inode_dirty(handle, inode);
1540 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1541 /* if we have allocated more blocks and copied
1542 * less. We will have blocks allocated outside
1543 * inode->i_size. So truncate them
1545 ext4_orphan_add(handle, inode);
1548 ret2 = ext4_journal_stop(handle);
1551 if (pos + len > inode->i_size) {
1552 ext4_truncate_failed_write(inode);
1554 * If truncate failed early the inode might still be
1555 * on the orphan list; we need to make sure the inode
1556 * is removed from the orphan list in that case.
1559 ext4_orphan_del(NULL, inode);
1562 return ret ? ret : copied;
1566 * Reserve space for a single cluster
1568 static int ext4_da_reserve_space(struct inode *inode)
1570 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1571 struct ext4_inode_info *ei = EXT4_I(inode);
1575 * We will charge metadata quota at writeout time; this saves
1576 * us from metadata over-estimation, though we may go over by
1577 * a small amount in the end. Here we just reserve for data.
1579 ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1));
1583 spin_lock(&ei->i_block_reservation_lock);
1584 if (ext4_claim_free_clusters(sbi, 1, 0)) {
1585 spin_unlock(&ei->i_block_reservation_lock);
1586 dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
1589 ei->i_reserved_data_blocks++;
1590 trace_ext4_da_reserve_space(inode);
1591 spin_unlock(&ei->i_block_reservation_lock);
1593 return 0; /* success */
1596 static void ext4_da_release_space(struct inode *inode, int to_free)
1598 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1599 struct ext4_inode_info *ei = EXT4_I(inode);
1602 return; /* Nothing to release, exit */
1604 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1606 trace_ext4_da_release_space(inode, to_free);
1607 if (unlikely(to_free > ei->i_reserved_data_blocks)) {
1609 * if there aren't enough reserved blocks, then the
1610 * counter is messed up somewhere. Since this
1611 * function is called from invalidate page, it's
1612 * harmless to return without any action.
1614 ext4_warning(inode->i_sb, "ext4_da_release_space: "
1615 "ino %lu, to_free %d with only %d reserved "
1616 "data blocks", inode->i_ino, to_free,
1617 ei->i_reserved_data_blocks);
1619 to_free = ei->i_reserved_data_blocks;
1621 ei->i_reserved_data_blocks -= to_free;
1623 /* update fs dirty data blocks counter */
1624 percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free);
1626 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1628 dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free));
1631 static void ext4_da_page_release_reservation(struct page *page,
1632 unsigned int offset,
1633 unsigned int length)
1635 int to_release = 0, contiguous_blks = 0;
1636 struct buffer_head *head, *bh;
1637 unsigned int curr_off = 0;
1638 struct inode *inode = page->mapping->host;
1639 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1640 unsigned int stop = offset + length;
1644 BUG_ON(stop > PAGE_SIZE || stop < length);
1646 head = page_buffers(page);
1649 unsigned int next_off = curr_off + bh->b_size;
1651 if (next_off > stop)
1654 if ((offset <= curr_off) && (buffer_delay(bh))) {
1657 clear_buffer_delay(bh);
1658 } else if (contiguous_blks) {
1659 lblk = page->index <<
1660 (PAGE_SHIFT - inode->i_blkbits);
1661 lblk += (curr_off >> inode->i_blkbits) -
1663 ext4_es_remove_extent(inode, lblk, contiguous_blks);
1664 contiguous_blks = 0;
1666 curr_off = next_off;
1667 } while ((bh = bh->b_this_page) != head);
1669 if (contiguous_blks) {
1670 lblk = page->index << (PAGE_SHIFT - inode->i_blkbits);
1671 lblk += (curr_off >> inode->i_blkbits) - contiguous_blks;
1672 ext4_es_remove_extent(inode, lblk, contiguous_blks);
1675 /* If we have released all the blocks belonging to a cluster, then we
1676 * need to release the reserved space for that cluster. */
1677 num_clusters = EXT4_NUM_B2C(sbi, to_release);
1678 while (num_clusters > 0) {
1679 lblk = (page->index << (PAGE_SHIFT - inode->i_blkbits)) +
1680 ((num_clusters - 1) << sbi->s_cluster_bits);
1681 if (sbi->s_cluster_ratio == 1 ||
1682 !ext4_find_delalloc_cluster(inode, lblk))
1683 ext4_da_release_space(inode, 1);
1690 * Delayed allocation stuff
1693 struct mpage_da_data {
1694 struct inode *inode;
1695 struct writeback_control *wbc;
1697 pgoff_t first_page; /* The first page to write */
1698 pgoff_t next_page; /* Current page to examine */
1699 pgoff_t last_page; /* Last page to examine */
1701 * Extent to map - this can be after first_page because that can be
1702 * fully mapped. We somewhat abuse m_flags to store whether the extent
1703 * is delalloc or unwritten.
1705 struct ext4_map_blocks map;
1706 struct ext4_io_submit io_submit; /* IO submission data */
1707 unsigned int do_map:1;
1710 static void mpage_release_unused_pages(struct mpage_da_data *mpd,
1715 struct pagevec pvec;
1716 struct inode *inode = mpd->inode;
1717 struct address_space *mapping = inode->i_mapping;
1719 /* This is necessary when next_page == 0. */
1720 if (mpd->first_page >= mpd->next_page)
1723 index = mpd->first_page;
1724 end = mpd->next_page - 1;
1726 ext4_lblk_t start, last;
1727 start = index << (PAGE_SHIFT - inode->i_blkbits);
1728 last = end << (PAGE_SHIFT - inode->i_blkbits);
1729 ext4_es_remove_extent(inode, start, last - start + 1);
1732 pagevec_init(&pvec);
1733 while (index <= end) {
1734 nr_pages = pagevec_lookup_range(&pvec, mapping, &index, end);
1737 for (i = 0; i < nr_pages; i++) {
1738 struct page *page = pvec.pages[i];
1740 BUG_ON(!PageLocked(page));
1741 BUG_ON(PageWriteback(page));
1743 if (page_mapped(page))
1744 clear_page_dirty_for_io(page);
1745 block_invalidatepage(page, 0, PAGE_SIZE);
1746 ClearPageUptodate(page);
1750 pagevec_release(&pvec);
1754 static void ext4_print_free_blocks(struct inode *inode)
1756 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1757 struct super_block *sb = inode->i_sb;
1758 struct ext4_inode_info *ei = EXT4_I(inode);
1760 ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld",
1761 EXT4_C2B(EXT4_SB(inode->i_sb),
1762 ext4_count_free_clusters(sb)));
1763 ext4_msg(sb, KERN_CRIT, "Free/Dirty block details");
1764 ext4_msg(sb, KERN_CRIT, "free_blocks=%lld",
1765 (long long) EXT4_C2B(EXT4_SB(sb),
1766 percpu_counter_sum(&sbi->s_freeclusters_counter)));
1767 ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld",
1768 (long long) EXT4_C2B(EXT4_SB(sb),
1769 percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
1770 ext4_msg(sb, KERN_CRIT, "Block reservation details");
1771 ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u",
1772 ei->i_reserved_data_blocks);
1776 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
1778 return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
1782 * This function is grabs code from the very beginning of
1783 * ext4_map_blocks, but assumes that the caller is from delayed write
1784 * time. This function looks up the requested blocks and sets the
1785 * buffer delay bit under the protection of i_data_sem.
1787 static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
1788 struct ext4_map_blocks *map,
1789 struct buffer_head *bh)
1791 struct extent_status es;
1793 sector_t invalid_block = ~((sector_t) 0xffff);
1794 #ifdef ES_AGGRESSIVE_TEST
1795 struct ext4_map_blocks orig_map;
1797 memcpy(&orig_map, map, sizeof(*map));
1800 if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
1804 ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u,"
1805 "logical block %lu\n", inode->i_ino, map->m_len,
1806 (unsigned long) map->m_lblk);
1808 /* Lookup extent status tree firstly */
1809 if (ext4_es_lookup_extent(inode, iblock, &es)) {
1810 if (ext4_es_is_hole(&es)) {
1812 down_read(&EXT4_I(inode)->i_data_sem);
1817 * Delayed extent could be allocated by fallocate.
1818 * So we need to check it.
1820 if (ext4_es_is_delayed(&es) && !ext4_es_is_unwritten(&es)) {
1821 map_bh(bh, inode->i_sb, invalid_block);
1823 set_buffer_delay(bh);
1827 map->m_pblk = ext4_es_pblock(&es) + iblock - es.es_lblk;
1828 retval = es.es_len - (iblock - es.es_lblk);
1829 if (retval > map->m_len)
1830 retval = map->m_len;
1831 map->m_len = retval;
1832 if (ext4_es_is_written(&es))
1833 map->m_flags |= EXT4_MAP_MAPPED;
1834 else if (ext4_es_is_unwritten(&es))
1835 map->m_flags |= EXT4_MAP_UNWRITTEN;
1839 #ifdef ES_AGGRESSIVE_TEST
1840 ext4_map_blocks_es_recheck(NULL, inode, map, &orig_map, 0);
1846 * Try to see if we can get the block without requesting a new
1847 * file system block.
1849 down_read(&EXT4_I(inode)->i_data_sem);
1850 if (ext4_has_inline_data(inode))
1852 else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
1853 retval = ext4_ext_map_blocks(NULL, inode, map, 0);
1855 retval = ext4_ind_map_blocks(NULL, inode, map, 0);
1861 * XXX: __block_prepare_write() unmaps passed block,
1865 * If the block was allocated from previously allocated cluster,
1866 * then we don't need to reserve it again. However we still need
1867 * to reserve metadata for every block we're going to write.
1869 if (EXT4_SB(inode->i_sb)->s_cluster_ratio == 1 ||
1870 !ext4_find_delalloc_cluster(inode, map->m_lblk)) {
1871 ret = ext4_da_reserve_space(inode);
1873 /* not enough space to reserve */
1879 ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
1880 ~0, EXTENT_STATUS_DELAYED);
1886 map_bh(bh, inode->i_sb, invalid_block);
1888 set_buffer_delay(bh);
1889 } else if (retval > 0) {
1891 unsigned int status;
1893 if (unlikely(retval != map->m_len)) {
1894 ext4_warning(inode->i_sb,
1895 "ES len assertion failed for inode "
1896 "%lu: retval %d != map->m_len %d",
1897 inode->i_ino, retval, map->m_len);
1901 status = map->m_flags & EXT4_MAP_UNWRITTEN ?
1902 EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
1903 ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
1904 map->m_pblk, status);
1910 up_read((&EXT4_I(inode)->i_data_sem));
1916 * This is a special get_block_t callback which is used by
1917 * ext4_da_write_begin(). It will either return mapped block or
1918 * reserve space for a single block.
1920 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
1921 * We also have b_blocknr = -1 and b_bdev initialized properly
1923 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
1924 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
1925 * initialized properly.
1927 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
1928 struct buffer_head *bh, int create)
1930 struct ext4_map_blocks map;
1933 BUG_ON(create == 0);
1934 BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
1936 map.m_lblk = iblock;
1940 * first, we need to know whether the block is allocated already
1941 * preallocated blocks are unmapped but should treated
1942 * the same as allocated blocks.
1944 ret = ext4_da_map_blocks(inode, iblock, &map, bh);
1948 map_bh(bh, inode->i_sb, map.m_pblk);
1949 ext4_update_bh_state(bh, map.m_flags);
1951 if (buffer_unwritten(bh)) {
1952 /* A delayed write to unwritten bh should be marked
1953 * new and mapped. Mapped ensures that we don't do
1954 * get_block multiple times when we write to the same
1955 * offset and new ensures that we do proper zero out
1956 * for partial write.
1959 set_buffer_mapped(bh);
1964 static int bget_one(handle_t *handle, struct buffer_head *bh)
1970 static int bput_one(handle_t *handle, struct buffer_head *bh)
1976 static int __ext4_journalled_writepage(struct page *page,
1979 struct address_space *mapping = page->mapping;
1980 struct inode *inode = mapping->host;
1981 struct buffer_head *page_bufs = NULL;
1982 handle_t *handle = NULL;
1983 int ret = 0, err = 0;
1984 int inline_data = ext4_has_inline_data(inode);
1985 struct buffer_head *inode_bh = NULL;
1987 ClearPageChecked(page);
1990 BUG_ON(page->index != 0);
1991 BUG_ON(len > ext4_get_max_inline_size(inode));
1992 inode_bh = ext4_journalled_write_inline_data(inode, len, page);
1993 if (inode_bh == NULL)
1996 page_bufs = page_buffers(page);
2001 ext4_walk_page_buffers(handle, page_bufs, 0, len,
2005 * We need to release the page lock before we start the
2006 * journal, so grab a reference so the page won't disappear
2007 * out from under us.
2012 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
2013 ext4_writepage_trans_blocks(inode));
2014 if (IS_ERR(handle)) {
2015 ret = PTR_ERR(handle);
2017 goto out_no_pagelock;
2019 BUG_ON(!ext4_handle_valid(handle));
2023 if (page->mapping != mapping) {
2024 /* The page got truncated from under us */
2025 ext4_journal_stop(handle);
2031 BUFFER_TRACE(inode_bh, "get write access");
2032 ret = ext4_journal_get_write_access(handle, inode_bh);
2034 err = ext4_handle_dirty_metadata(handle, inode, inode_bh);
2037 ret = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
2038 do_journal_get_write_access);
2040 err = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
2045 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
2046 err = ext4_journal_stop(handle);
2050 if (!ext4_has_inline_data(inode))
2051 ext4_walk_page_buffers(NULL, page_bufs, 0, len,
2053 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
2062 * Note that we don't need to start a transaction unless we're journaling data
2063 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2064 * need to file the inode to the transaction's list in ordered mode because if
2065 * we are writing back data added by write(), the inode is already there and if
2066 * we are writing back data modified via mmap(), no one guarantees in which
2067 * transaction the data will hit the disk. In case we are journaling data, we
2068 * cannot start transaction directly because transaction start ranks above page
2069 * lock so we have to do some magic.
2071 * This function can get called via...
2072 * - ext4_writepages after taking page lock (have journal handle)
2073 * - journal_submit_inode_data_buffers (no journal handle)
2074 * - shrink_page_list via the kswapd/direct reclaim (no journal handle)
2075 * - grab_page_cache when doing write_begin (have journal handle)
2077 * We don't do any block allocation in this function. If we have page with
2078 * multiple blocks we need to write those buffer_heads that are mapped. This
2079 * is important for mmaped based write. So if we do with blocksize 1K
2080 * truncate(f, 1024);
2081 * a = mmap(f, 0, 4096);
2083 * truncate(f, 4096);
2084 * we have in the page first buffer_head mapped via page_mkwrite call back
2085 * but other buffer_heads would be unmapped but dirty (dirty done via the
2086 * do_wp_page). So writepage should write the first block. If we modify
2087 * the mmap area beyond 1024 we will again get a page_fault and the
2088 * page_mkwrite callback will do the block allocation and mark the
2089 * buffer_heads mapped.
2091 * We redirty the page if we have any buffer_heads that is either delay or
2092 * unwritten in the page.
2094 * We can get recursively called as show below.
2096 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2099 * But since we don't do any block allocation we should not deadlock.
2100 * Page also have the dirty flag cleared so we don't get recurive page_lock.
2102 static int ext4_writepage(struct page *page,
2103 struct writeback_control *wbc)
2108 struct buffer_head *page_bufs = NULL;
2109 struct inode *inode = page->mapping->host;
2110 struct ext4_io_submit io_submit;
2111 bool keep_towrite = false;
2113 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) {
2114 ext4_invalidatepage(page, 0, PAGE_SIZE);
2119 trace_ext4_writepage(page);
2120 size = i_size_read(inode);
2121 if (page->index == size >> PAGE_SHIFT)
2122 len = size & ~PAGE_MASK;
2126 page_bufs = page_buffers(page);
2128 * We cannot do block allocation or other extent handling in this
2129 * function. If there are buffers needing that, we have to redirty
2130 * the page. But we may reach here when we do a journal commit via
2131 * journal_submit_inode_data_buffers() and in that case we must write
2132 * allocated buffers to achieve data=ordered mode guarantees.
2134 * Also, if there is only one buffer per page (the fs block
2135 * size == the page size), if one buffer needs block
2136 * allocation or needs to modify the extent tree to clear the
2137 * unwritten flag, we know that the page can't be written at
2138 * all, so we might as well refuse the write immediately.
2139 * Unfortunately if the block size != page size, we can't as
2140 * easily detect this case using ext4_walk_page_buffers(), but
2141 * for the extremely common case, this is an optimization that
2142 * skips a useless round trip through ext4_bio_write_page().
2144 if (ext4_walk_page_buffers(NULL, page_bufs, 0, len, NULL,
2145 ext4_bh_delay_or_unwritten)) {
2146 redirty_page_for_writepage(wbc, page);
2147 if ((current->flags & PF_MEMALLOC) ||
2148 (inode->i_sb->s_blocksize == PAGE_SIZE)) {
2150 * For memory cleaning there's no point in writing only
2151 * some buffers. So just bail out. Warn if we came here
2152 * from direct reclaim.
2154 WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD))
2159 keep_towrite = true;
2162 if (PageChecked(page) && ext4_should_journal_data(inode))
2164 * It's mmapped pagecache. Add buffers and journal it. There
2165 * doesn't seem much point in redirtying the page here.
2167 return __ext4_journalled_writepage(page, len);
2169 ext4_io_submit_init(&io_submit, wbc);
2170 io_submit.io_end = ext4_init_io_end(inode, GFP_NOFS);
2171 if (!io_submit.io_end) {
2172 redirty_page_for_writepage(wbc, page);
2176 ret = ext4_bio_write_page(&io_submit, page, len, wbc, keep_towrite);
2177 ext4_io_submit(&io_submit);
2178 /* Drop io_end reference we got from init */
2179 ext4_put_io_end_defer(io_submit.io_end);
2183 static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page)
2189 BUG_ON(page->index != mpd->first_page);
2190 clear_page_dirty_for_io(page);
2192 * We have to be very careful here! Nothing protects writeback path
2193 * against i_size changes and the page can be writeably mapped into
2194 * page tables. So an application can be growing i_size and writing
2195 * data through mmap while writeback runs. clear_page_dirty_for_io()
2196 * write-protects our page in page tables and the page cannot get
2197 * written to again until we release page lock. So only after
2198 * clear_page_dirty_for_io() we are safe to sample i_size for
2199 * ext4_bio_write_page() to zero-out tail of the written page. We rely
2200 * on the barrier provided by TestClearPageDirty in
2201 * clear_page_dirty_for_io() to make sure i_size is really sampled only
2202 * after page tables are updated.
2204 size = i_size_read(mpd->inode);
2205 if (page->index == size >> PAGE_SHIFT)
2206 len = size & ~PAGE_MASK;
2209 err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc, false);
2211 mpd->wbc->nr_to_write--;
2217 #define BH_FLAGS ((1 << BH_Unwritten) | (1 << BH_Delay))
2220 * mballoc gives us at most this number of blocks...
2221 * XXX: That seems to be only a limitation of ext4_mb_normalize_request().
2222 * The rest of mballoc seems to handle chunks up to full group size.
2224 #define MAX_WRITEPAGES_EXTENT_LEN 2048
2227 * mpage_add_bh_to_extent - try to add bh to extent of blocks to map
2229 * @mpd - extent of blocks
2230 * @lblk - logical number of the block in the file
2231 * @bh - buffer head we want to add to the extent
2233 * The function is used to collect contig. blocks in the same state. If the
2234 * buffer doesn't require mapping for writeback and we haven't started the
2235 * extent of buffers to map yet, the function returns 'true' immediately - the
2236 * caller can write the buffer right away. Otherwise the function returns true
2237 * if the block has been added to the extent, false if the block couldn't be
2240 static bool mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk,
2241 struct buffer_head *bh)
2243 struct ext4_map_blocks *map = &mpd->map;
2245 /* Buffer that doesn't need mapping for writeback? */
2246 if (!buffer_dirty(bh) || !buffer_mapped(bh) ||
2247 (!buffer_delay(bh) && !buffer_unwritten(bh))) {
2248 /* So far no extent to map => we write the buffer right away */
2249 if (map->m_len == 0)
2254 /* First block in the extent? */
2255 if (map->m_len == 0) {
2256 /* We cannot map unless handle is started... */
2261 map->m_flags = bh->b_state & BH_FLAGS;
2265 /* Don't go larger than mballoc is willing to allocate */
2266 if (map->m_len >= MAX_WRITEPAGES_EXTENT_LEN)
2269 /* Can we merge the block to our big extent? */
2270 if (lblk == map->m_lblk + map->m_len &&
2271 (bh->b_state & BH_FLAGS) == map->m_flags) {
2279 * mpage_process_page_bufs - submit page buffers for IO or add them to extent
2281 * @mpd - extent of blocks for mapping
2282 * @head - the first buffer in the page
2283 * @bh - buffer we should start processing from
2284 * @lblk - logical number of the block in the file corresponding to @bh
2286 * Walk through page buffers from @bh upto @head (exclusive) and either submit
2287 * the page for IO if all buffers in this page were mapped and there's no
2288 * accumulated extent of buffers to map or add buffers in the page to the
2289 * extent of buffers to map. The function returns 1 if the caller can continue
2290 * by processing the next page, 0 if it should stop adding buffers to the
2291 * extent to map because we cannot extend it anymore. It can also return value
2292 * < 0 in case of error during IO submission.
2294 static int mpage_process_page_bufs(struct mpage_da_data *mpd,
2295 struct buffer_head *head,
2296 struct buffer_head *bh,
2299 struct inode *inode = mpd->inode;
2301 ext4_lblk_t blocks = (i_size_read(inode) + i_blocksize(inode) - 1)
2302 >> inode->i_blkbits;
2305 BUG_ON(buffer_locked(bh));
2307 if (lblk >= blocks || !mpage_add_bh_to_extent(mpd, lblk, bh)) {
2308 /* Found extent to map? */
2311 /* Buffer needs mapping and handle is not started? */
2314 /* Everything mapped so far and we hit EOF */
2317 } while (lblk++, (bh = bh->b_this_page) != head);
2318 /* So far everything mapped? Submit the page for IO. */
2319 if (mpd->map.m_len == 0) {
2320 err = mpage_submit_page(mpd, head->b_page);
2324 return lblk < blocks;
2328 * mpage_map_buffers - update buffers corresponding to changed extent and
2329 * submit fully mapped pages for IO
2331 * @mpd - description of extent to map, on return next extent to map
2333 * Scan buffers corresponding to changed extent (we expect corresponding pages
2334 * to be already locked) and update buffer state according to new extent state.
2335 * We map delalloc buffers to their physical location, clear unwritten bits,
2336 * and mark buffers as uninit when we perform writes to unwritten extents
2337 * and do extent conversion after IO is finished. If the last page is not fully
2338 * mapped, we update @map to the next extent in the last page that needs
2339 * mapping. Otherwise we submit the page for IO.
2341 static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd)
2343 struct pagevec pvec;
2345 struct inode *inode = mpd->inode;
2346 struct buffer_head *head, *bh;
2347 int bpp_bits = PAGE_SHIFT - inode->i_blkbits;
2353 start = mpd->map.m_lblk >> bpp_bits;
2354 end = (mpd->map.m_lblk + mpd->map.m_len - 1) >> bpp_bits;
2355 lblk = start << bpp_bits;
2356 pblock = mpd->map.m_pblk;
2358 pagevec_init(&pvec);
2359 while (start <= end) {
2360 nr_pages = pagevec_lookup_range(&pvec, inode->i_mapping,
2364 for (i = 0; i < nr_pages; i++) {
2365 struct page *page = pvec.pages[i];
2367 bh = head = page_buffers(page);
2369 if (lblk < mpd->map.m_lblk)
2371 if (lblk >= mpd->map.m_lblk + mpd->map.m_len) {
2373 * Buffer after end of mapped extent.
2374 * Find next buffer in the page to map.
2377 mpd->map.m_flags = 0;
2379 * FIXME: If dioread_nolock supports
2380 * blocksize < pagesize, we need to make
2381 * sure we add size mapped so far to
2382 * io_end->size as the following call
2383 * can submit the page for IO.
2385 err = mpage_process_page_bufs(mpd, head,
2387 pagevec_release(&pvec);
2392 if (buffer_delay(bh)) {
2393 clear_buffer_delay(bh);
2394 bh->b_blocknr = pblock++;
2396 clear_buffer_unwritten(bh);
2397 } while (lblk++, (bh = bh->b_this_page) != head);
2400 * FIXME: This is going to break if dioread_nolock
2401 * supports blocksize < pagesize as we will try to
2402 * convert potentially unmapped parts of inode.
2404 mpd->io_submit.io_end->size += PAGE_SIZE;
2405 /* Page fully mapped - let IO run! */
2406 err = mpage_submit_page(mpd, page);
2408 pagevec_release(&pvec);
2412 pagevec_release(&pvec);
2414 /* Extent fully mapped and matches with page boundary. We are done. */
2416 mpd->map.m_flags = 0;
2420 static int mpage_map_one_extent(handle_t *handle, struct mpage_da_data *mpd)
2422 struct inode *inode = mpd->inode;
2423 struct ext4_map_blocks *map = &mpd->map;
2424 int get_blocks_flags;
2425 int err, dioread_nolock;
2427 trace_ext4_da_write_pages_extent(inode, map);
2429 * Call ext4_map_blocks() to allocate any delayed allocation blocks, or
2430 * to convert an unwritten extent to be initialized (in the case
2431 * where we have written into one or more preallocated blocks). It is
2432 * possible that we're going to need more metadata blocks than
2433 * previously reserved. However we must not fail because we're in
2434 * writeback and there is nothing we can do about it so it might result
2435 * in data loss. So use reserved blocks to allocate metadata if
2438 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE if
2439 * the blocks in question are delalloc blocks. This indicates
2440 * that the blocks and quotas has already been checked when
2441 * the data was copied into the page cache.
2443 get_blocks_flags = EXT4_GET_BLOCKS_CREATE |
2444 EXT4_GET_BLOCKS_METADATA_NOFAIL |
2445 EXT4_GET_BLOCKS_IO_SUBMIT;
2446 dioread_nolock = ext4_should_dioread_nolock(inode);
2448 get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
2449 if (map->m_flags & (1 << BH_Delay))
2450 get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
2452 err = ext4_map_blocks(handle, inode, map, get_blocks_flags);
2455 if (dioread_nolock && (map->m_flags & EXT4_MAP_UNWRITTEN)) {
2456 if (!mpd->io_submit.io_end->handle &&
2457 ext4_handle_valid(handle)) {
2458 mpd->io_submit.io_end->handle = handle->h_rsv_handle;
2459 handle->h_rsv_handle = NULL;
2461 ext4_set_io_unwritten_flag(inode, mpd->io_submit.io_end);
2464 BUG_ON(map->m_len == 0);
2465 if (map->m_flags & EXT4_MAP_NEW) {
2466 clean_bdev_aliases(inode->i_sb->s_bdev, map->m_pblk,
2473 * mpage_map_and_submit_extent - map extent starting at mpd->lblk of length
2474 * mpd->len and submit pages underlying it for IO
2476 * @handle - handle for journal operations
2477 * @mpd - extent to map
2478 * @give_up_on_write - we set this to true iff there is a fatal error and there
2479 * is no hope of writing the data. The caller should discard
2480 * dirty pages to avoid infinite loops.
2482 * The function maps extent starting at mpd->lblk of length mpd->len. If it is
2483 * delayed, blocks are allocated, if it is unwritten, we may need to convert
2484 * them to initialized or split the described range from larger unwritten
2485 * extent. Note that we need not map all the described range since allocation
2486 * can return less blocks or the range is covered by more unwritten extents. We
2487 * cannot map more because we are limited by reserved transaction credits. On
2488 * the other hand we always make sure that the last touched page is fully
2489 * mapped so that it can be written out (and thus forward progress is
2490 * guaranteed). After mapping we submit all mapped pages for IO.
2492 static int mpage_map_and_submit_extent(handle_t *handle,
2493 struct mpage_da_data *mpd,
2494 bool *give_up_on_write)
2496 struct inode *inode = mpd->inode;
2497 struct ext4_map_blocks *map = &mpd->map;
2502 mpd->io_submit.io_end->offset =
2503 ((loff_t)map->m_lblk) << inode->i_blkbits;
2505 err = mpage_map_one_extent(handle, mpd);
2507 struct super_block *sb = inode->i_sb;
2509 if (ext4_forced_shutdown(EXT4_SB(sb)) ||
2510 EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
2511 goto invalidate_dirty_pages;
2513 * Let the uper layers retry transient errors.
2514 * In the case of ENOSPC, if ext4_count_free_blocks()
2515 * is non-zero, a commit should free up blocks.
2517 if ((err == -ENOMEM) ||
2518 (err == -ENOSPC && ext4_count_free_clusters(sb))) {
2520 goto update_disksize;
2523 ext4_msg(sb, KERN_CRIT,
2524 "Delayed block allocation failed for "
2525 "inode %lu at logical offset %llu with"
2526 " max blocks %u with error %d",
2528 (unsigned long long)map->m_lblk,
2529 (unsigned)map->m_len, -err);
2530 ext4_msg(sb, KERN_CRIT,
2531 "This should not happen!! Data will "
2534 ext4_print_free_blocks(inode);
2535 invalidate_dirty_pages:
2536 *give_up_on_write = true;
2541 * Update buffer state, submit mapped pages, and get us new
2544 err = mpage_map_and_submit_buffers(mpd);
2546 goto update_disksize;
2547 } while (map->m_len);
2551 * Update on-disk size after IO is submitted. Races with
2552 * truncate are avoided by checking i_size under i_data_sem.
2554 disksize = ((loff_t)mpd->first_page) << PAGE_SHIFT;
2555 if (disksize > EXT4_I(inode)->i_disksize) {
2559 down_write(&EXT4_I(inode)->i_data_sem);
2560 i_size = i_size_read(inode);
2561 if (disksize > i_size)
2563 if (disksize > EXT4_I(inode)->i_disksize)
2564 EXT4_I(inode)->i_disksize = disksize;
2565 up_write(&EXT4_I(inode)->i_data_sem);
2566 err2 = ext4_mark_inode_dirty(handle, inode);
2568 ext4_error(inode->i_sb,
2569 "Failed to mark inode %lu dirty",
2578 * Calculate the total number of credits to reserve for one writepages
2579 * iteration. This is called from ext4_writepages(). We map an extent of
2580 * up to MAX_WRITEPAGES_EXTENT_LEN blocks and then we go on and finish mapping
2581 * the last partial page. So in total we can map MAX_WRITEPAGES_EXTENT_LEN +
2582 * bpp - 1 blocks in bpp different extents.
2584 static int ext4_da_writepages_trans_blocks(struct inode *inode)
2586 int bpp = ext4_journal_blocks_per_page(inode);
2588 return ext4_meta_trans_blocks(inode,
2589 MAX_WRITEPAGES_EXTENT_LEN + bpp - 1, bpp);
2593 * mpage_prepare_extent_to_map - find & lock contiguous range of dirty pages
2594 * and underlying extent to map
2596 * @mpd - where to look for pages
2598 * Walk dirty pages in the mapping. If they are fully mapped, submit them for
2599 * IO immediately. When we find a page which isn't mapped we start accumulating
2600 * extent of buffers underlying these pages that needs mapping (formed by
2601 * either delayed or unwritten buffers). We also lock the pages containing
2602 * these buffers. The extent found is returned in @mpd structure (starting at
2603 * mpd->lblk with length mpd->len blocks).
2605 * Note that this function can attach bios to one io_end structure which are
2606 * neither logically nor physically contiguous. Although it may seem as an
2607 * unnecessary complication, it is actually inevitable in blocksize < pagesize
2608 * case as we need to track IO to all buffers underlying a page in one io_end.
2610 static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
2612 struct address_space *mapping = mpd->inode->i_mapping;
2613 struct pagevec pvec;
2614 unsigned int nr_pages;
2615 long left = mpd->wbc->nr_to_write;
2616 pgoff_t index = mpd->first_page;
2617 pgoff_t end = mpd->last_page;
2620 int blkbits = mpd->inode->i_blkbits;
2622 struct buffer_head *head;
2624 if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages)
2625 tag = PAGECACHE_TAG_TOWRITE;
2627 tag = PAGECACHE_TAG_DIRTY;
2629 pagevec_init(&pvec);
2631 mpd->next_page = index;
2632 while (index <= end) {
2633 nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
2638 for (i = 0; i < nr_pages; i++) {
2639 struct page *page = pvec.pages[i];
2642 * Accumulated enough dirty pages? This doesn't apply
2643 * to WB_SYNC_ALL mode. For integrity sync we have to
2644 * keep going because someone may be concurrently
2645 * dirtying pages, and we might have synced a lot of
2646 * newly appeared dirty pages, but have not synced all
2647 * of the old dirty pages.
2649 if (mpd->wbc->sync_mode == WB_SYNC_NONE && left <= 0)
2652 /* If we can't merge this page, we are done. */
2653 if (mpd->map.m_len > 0 && mpd->next_page != page->index)
2658 * If the page is no longer dirty, or its mapping no
2659 * longer corresponds to inode we are writing (which
2660 * means it has been truncated or invalidated), or the
2661 * page is already under writeback and we are not doing
2662 * a data integrity writeback, skip the page
2664 if (!PageDirty(page) ||
2665 (PageWriteback(page) &&
2666 (mpd->wbc->sync_mode == WB_SYNC_NONE)) ||
2667 unlikely(page->mapping != mapping)) {
2672 wait_on_page_writeback(page);
2673 BUG_ON(PageWriteback(page));
2675 if (mpd->map.m_len == 0)
2676 mpd->first_page = page->index;
2677 mpd->next_page = page->index + 1;
2678 /* Add all dirty buffers to mpd */
2679 lblk = ((ext4_lblk_t)page->index) <<
2680 (PAGE_SHIFT - blkbits);
2681 head = page_buffers(page);
2682 err = mpage_process_page_bufs(mpd, head, head, lblk);
2688 pagevec_release(&pvec);
2693 pagevec_release(&pvec);
2697 static int ext4_writepages(struct address_space *mapping,
2698 struct writeback_control *wbc)
2700 pgoff_t writeback_index = 0;
2701 long nr_to_write = wbc->nr_to_write;
2702 int range_whole = 0;
2704 handle_t *handle = NULL;
2705 struct mpage_da_data mpd;
2706 struct inode *inode = mapping->host;
2707 int needed_blocks, rsv_blocks = 0, ret = 0;
2708 struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
2710 struct blk_plug plug;
2711 bool give_up_on_write = false;
2713 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
2716 percpu_down_read(&sbi->s_journal_flag_rwsem);
2717 trace_ext4_writepages(inode, wbc);
2719 if (dax_mapping(mapping)) {
2720 ret = dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev,
2722 goto out_writepages;
2726 * No pages to write? This is mainly a kludge to avoid starting
2727 * a transaction for special inodes like journal inode on last iput()
2728 * because that could violate lock ordering on umount
2730 if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2731 goto out_writepages;
2733 if (ext4_should_journal_data(inode)) {
2734 ret = generic_writepages(mapping, wbc);
2735 goto out_writepages;
2739 * If the filesystem has aborted, it is read-only, so return
2740 * right away instead of dumping stack traces later on that
2741 * will obscure the real source of the problem. We test
2742 * EXT4_MF_FS_ABORTED instead of sb->s_flag's SB_RDONLY because
2743 * the latter could be true if the filesystem is mounted
2744 * read-only, and in that case, ext4_writepages should
2745 * *never* be called, so if that ever happens, we would want
2748 if (unlikely(ext4_forced_shutdown(EXT4_SB(mapping->host->i_sb)) ||
2749 sbi->s_mount_flags & EXT4_MF_FS_ABORTED)) {
2751 goto out_writepages;
2754 if (ext4_should_dioread_nolock(inode)) {
2756 * We may need to convert up to one extent per block in
2757 * the page and we may dirty the inode.
2759 rsv_blocks = 1 + (PAGE_SIZE >> inode->i_blkbits);
2763 * If we have inline data and arrive here, it means that
2764 * we will soon create the block for the 1st page, so
2765 * we'd better clear the inline data here.
2767 if (ext4_has_inline_data(inode)) {
2768 /* Just inode will be modified... */
2769 handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
2770 if (IS_ERR(handle)) {
2771 ret = PTR_ERR(handle);
2772 goto out_writepages;
2774 BUG_ON(ext4_test_inode_state(inode,
2775 EXT4_STATE_MAY_INLINE_DATA));
2776 ext4_destroy_inline_data(handle, inode);
2777 ext4_journal_stop(handle);
2780 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2783 if (wbc->range_cyclic) {
2784 writeback_index = mapping->writeback_index;
2785 if (writeback_index)
2787 mpd.first_page = writeback_index;
2790 mpd.first_page = wbc->range_start >> PAGE_SHIFT;
2791 mpd.last_page = wbc->range_end >> PAGE_SHIFT;
2796 ext4_io_submit_init(&mpd.io_submit, wbc);
2798 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2799 tag_pages_for_writeback(mapping, mpd.first_page, mpd.last_page);
2801 blk_start_plug(&plug);
2804 * First writeback pages that don't need mapping - we can avoid
2805 * starting a transaction unnecessarily and also avoid being blocked
2806 * in the block layer on device congestion while having transaction
2810 mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL);
2811 if (!mpd.io_submit.io_end) {
2815 ret = mpage_prepare_extent_to_map(&mpd);
2816 /* Submit prepared bio */
2817 ext4_io_submit(&mpd.io_submit);
2818 ext4_put_io_end_defer(mpd.io_submit.io_end);
2819 mpd.io_submit.io_end = NULL;
2820 /* Unlock pages we didn't use */
2821 mpage_release_unused_pages(&mpd, false);
2825 while (!done && mpd.first_page <= mpd.last_page) {
2826 /* For each extent of pages we use new io_end */
2827 mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL);
2828 if (!mpd.io_submit.io_end) {
2834 * We have two constraints: We find one extent to map and we
2835 * must always write out whole page (makes a difference when
2836 * blocksize < pagesize) so that we don't block on IO when we
2837 * try to write out the rest of the page. Journalled mode is
2838 * not supported by delalloc.
2840 BUG_ON(ext4_should_journal_data(inode));
2841 needed_blocks = ext4_da_writepages_trans_blocks(inode);
2843 /* start a new transaction */
2844 handle = ext4_journal_start_with_reserve(inode,
2845 EXT4_HT_WRITE_PAGE, needed_blocks, rsv_blocks);
2846 if (IS_ERR(handle)) {
2847 ret = PTR_ERR(handle);
2848 ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
2849 "%ld pages, ino %lu; err %d", __func__,
2850 wbc->nr_to_write, inode->i_ino, ret);
2851 /* Release allocated io_end */
2852 ext4_put_io_end(mpd.io_submit.io_end);
2853 mpd.io_submit.io_end = NULL;
2858 trace_ext4_da_write_pages(inode, mpd.first_page, mpd.wbc);
2859 ret = mpage_prepare_extent_to_map(&mpd);
2862 ret = mpage_map_and_submit_extent(handle, &mpd,
2866 * We scanned the whole range (or exhausted
2867 * nr_to_write), submitted what was mapped and
2868 * didn't find anything needing mapping. We are
2875 * Caution: If the handle is synchronous,
2876 * ext4_journal_stop() can wait for transaction commit
2877 * to finish which may depend on writeback of pages to
2878 * complete or on page lock to be released. In that
2879 * case, we have to wait until after after we have
2880 * submitted all the IO, released page locks we hold,
2881 * and dropped io_end reference (for extent conversion
2882 * to be able to complete) before stopping the handle.
2884 if (!ext4_handle_valid(handle) || handle->h_sync == 0) {
2885 ext4_journal_stop(handle);
2889 /* Submit prepared bio */
2890 ext4_io_submit(&mpd.io_submit);
2891 /* Unlock pages we didn't use */
2892 mpage_release_unused_pages(&mpd, give_up_on_write);
2894 * Drop our io_end reference we got from init. We have
2895 * to be careful and use deferred io_end finishing if
2896 * we are still holding the transaction as we can
2897 * release the last reference to io_end which may end
2898 * up doing unwritten extent conversion.
2901 ext4_put_io_end_defer(mpd.io_submit.io_end);
2902 ext4_journal_stop(handle);
2904 ext4_put_io_end(mpd.io_submit.io_end);
2905 mpd.io_submit.io_end = NULL;
2907 if (ret == -ENOSPC && sbi->s_journal) {
2909 * Commit the transaction which would
2910 * free blocks released in the transaction
2913 jbd2_journal_force_commit_nested(sbi->s_journal);
2917 /* Fatal error - ENOMEM, EIO... */
2922 blk_finish_plug(&plug);
2923 if (!ret && !cycled && wbc->nr_to_write > 0) {
2925 mpd.last_page = writeback_index - 1;
2931 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2933 * Set the writeback_index so that range_cyclic
2934 * mode will write it back later
2936 mapping->writeback_index = mpd.first_page;
2939 trace_ext4_writepages_result(inode, wbc, ret,
2940 nr_to_write - wbc->nr_to_write);
2941 percpu_up_read(&sbi->s_journal_flag_rwsem);
2945 static int ext4_nonda_switch(struct super_block *sb)
2947 s64 free_clusters, dirty_clusters;
2948 struct ext4_sb_info *sbi = EXT4_SB(sb);
2951 * switch to non delalloc mode if we are running low
2952 * on free block. The free block accounting via percpu
2953 * counters can get slightly wrong with percpu_counter_batch getting
2954 * accumulated on each CPU without updating global counters
2955 * Delalloc need an accurate free block accounting. So switch
2956 * to non delalloc when we are near to error range.
2959 percpu_counter_read_positive(&sbi->s_freeclusters_counter);
2961 percpu_counter_read_positive(&sbi->s_dirtyclusters_counter);
2963 * Start pushing delalloc when 1/2 of free blocks are dirty.
2965 if (dirty_clusters && (free_clusters < 2 * dirty_clusters))
2966 try_to_writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE);
2968 if (2 * free_clusters < 3 * dirty_clusters ||
2969 free_clusters < (dirty_clusters + EXT4_FREECLUSTERS_WATERMARK)) {
2971 * free block count is less than 150% of dirty blocks
2972 * or free blocks is less than watermark
2979 /* We always reserve for an inode update; the superblock could be there too */
2980 static int ext4_da_write_credits(struct inode *inode, loff_t pos, unsigned len)
2982 if (likely(ext4_has_feature_large_file(inode->i_sb)))
2985 if (pos + len <= 0x7fffffffULL)
2988 /* We might need to update the superblock to set LARGE_FILE */
2992 static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
2993 loff_t pos, unsigned len, unsigned flags,
2994 struct page **pagep, void **fsdata)
2996 int ret, retries = 0;
2999 struct inode *inode = mapping->host;
3002 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
3005 index = pos >> PAGE_SHIFT;
3007 if (ext4_nonda_switch(inode->i_sb) ||
3008 S_ISLNK(inode->i_mode)) {
3009 *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
3010 return ext4_write_begin(file, mapping, pos,
3011 len, flags, pagep, fsdata);
3013 *fsdata = (void *)0;
3014 trace_ext4_da_write_begin(inode, pos, len, flags);
3016 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
3017 ret = ext4_da_write_inline_data_begin(mapping, inode,
3027 * grab_cache_page_write_begin() can take a long time if the
3028 * system is thrashing due to memory pressure, or if the page
3029 * is being written back. So grab it first before we start
3030 * the transaction handle. This also allows us to allocate
3031 * the page (if needed) without using GFP_NOFS.
3034 page = grab_cache_page_write_begin(mapping, index, flags);
3040 * With delayed allocation, we don't log the i_disksize update
3041 * if there is delayed block allocation. But we still need
3042 * to journalling the i_disksize update if writes to the end
3043 * of file which has an already mapped buffer.
3046 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
3047 ext4_da_write_credits(inode, pos, len));
3048 if (IS_ERR(handle)) {
3050 return PTR_ERR(handle);
3054 if (page->mapping != mapping) {
3055 /* The page got truncated from under us */
3058 ext4_journal_stop(handle);
3061 /* In case writeback began while the page was unlocked */
3062 wait_for_stable_page(page);
3064 #ifdef CONFIG_EXT4_FS_ENCRYPTION
3065 ret = ext4_block_write_begin(page, pos, len,
3066 ext4_da_get_block_prep);
3068 ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep);
3072 ext4_journal_stop(handle);
3074 * block_write_begin may have instantiated a few blocks
3075 * outside i_size. Trim these off again. Don't need
3076 * i_size_read because we hold i_mutex.
3078 if (pos + len > inode->i_size)
3079 ext4_truncate_failed_write(inode);
3081 if (ret == -ENOSPC &&
3082 ext4_should_retry_alloc(inode->i_sb, &retries))
3094 * Check if we should update i_disksize
3095 * when write to the end of file but not require block allocation
3097 static int ext4_da_should_update_i_disksize(struct page *page,
3098 unsigned long offset)
3100 struct buffer_head *bh;
3101 struct inode *inode = page->mapping->host;
3105 bh = page_buffers(page);
3106 idx = offset >> inode->i_blkbits;
3108 for (i = 0; i < idx; i++)
3109 bh = bh->b_this_page;
3111 if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
3116 static int ext4_da_write_end(struct file *file,
3117 struct address_space *mapping,
3118 loff_t pos, unsigned len, unsigned copied,
3119 struct page *page, void *fsdata)
3121 struct inode *inode = mapping->host;
3123 handle_t *handle = ext4_journal_current_handle();
3125 unsigned long start, end;
3126 int write_mode = (int)(unsigned long)fsdata;
3128 if (write_mode == FALL_BACK_TO_NONDELALLOC)
3129 return ext4_write_end(file, mapping, pos,
3130 len, copied, page, fsdata);
3132 trace_ext4_da_write_end(inode, pos, len, copied);
3133 start = pos & (PAGE_SIZE - 1);
3134 end = start + copied - 1;
3137 * generic_write_end() will run mark_inode_dirty() if i_size
3138 * changes. So let's piggyback the i_disksize mark_inode_dirty
3141 new_i_size = pos + copied;
3142 if (copied && new_i_size > EXT4_I(inode)->i_disksize) {
3143 if (ext4_has_inline_data(inode) ||
3144 ext4_da_should_update_i_disksize(page, end)) {
3145 ext4_update_i_disksize(inode, new_i_size);
3146 /* We need to mark inode dirty even if
3147 * new_i_size is less that inode->i_size
3148 * bu greater than i_disksize.(hint delalloc)
3150 ext4_mark_inode_dirty(handle, inode);
3154 if (write_mode != CONVERT_INLINE_DATA &&
3155 ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) &&
3156 ext4_has_inline_data(inode))
3157 ret2 = ext4_da_write_inline_data_end(inode, pos, len, copied,
3160 ret2 = generic_write_end(file, mapping, pos, len, copied,
3166 ret2 = ext4_journal_stop(handle);
3170 return ret ? ret : copied;
3173 static void ext4_da_invalidatepage(struct page *page, unsigned int offset,
3174 unsigned int length)
3177 * Drop reserved blocks
3179 BUG_ON(!PageLocked(page));
3180 if (!page_has_buffers(page))
3183 ext4_da_page_release_reservation(page, offset, length);
3186 ext4_invalidatepage(page, offset, length);
3192 * Force all delayed allocation blocks to be allocated for a given inode.
3194 int ext4_alloc_da_blocks(struct inode *inode)
3196 trace_ext4_alloc_da_blocks(inode);
3198 if (!EXT4_I(inode)->i_reserved_data_blocks)
3202 * We do something simple for now. The filemap_flush() will
3203 * also start triggering a write of the data blocks, which is
3204 * not strictly speaking necessary (and for users of
3205 * laptop_mode, not even desirable). However, to do otherwise
3206 * would require replicating code paths in:
3208 * ext4_writepages() ->
3209 * write_cache_pages() ---> (via passed in callback function)
3210 * __mpage_da_writepage() -->
3211 * mpage_add_bh_to_extent()
3212 * mpage_da_map_blocks()
3214 * The problem is that write_cache_pages(), located in
3215 * mm/page-writeback.c, marks pages clean in preparation for
3216 * doing I/O, which is not desirable if we're not planning on
3219 * We could call write_cache_pages(), and then redirty all of
3220 * the pages by calling redirty_page_for_writepage() but that
3221 * would be ugly in the extreme. So instead we would need to
3222 * replicate parts of the code in the above functions,
3223 * simplifying them because we wouldn't actually intend to
3224 * write out the pages, but rather only collect contiguous
3225 * logical block extents, call the multi-block allocator, and
3226 * then update the buffer heads with the block allocations.
3228 * For now, though, we'll cheat by calling filemap_flush(),
3229 * which will map the blocks, and start the I/O, but not
3230 * actually wait for the I/O to complete.
3232 return filemap_flush(inode->i_mapping);
3236 * bmap() is special. It gets used by applications such as lilo and by
3237 * the swapper to find the on-disk block of a specific piece of data.
3239 * Naturally, this is dangerous if the block concerned is still in the
3240 * journal. If somebody makes a swapfile on an ext4 data-journaling
3241 * filesystem and enables swap, then they may get a nasty shock when the
3242 * data getting swapped to that swapfile suddenly gets overwritten by
3243 * the original zero's written out previously to the journal and
3244 * awaiting writeback in the kernel's buffer cache.
3246 * So, if we see any bmap calls here on a modified, data-journaled file,
3247 * take extra steps to flush any blocks which might be in the cache.
3249 static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
3251 struct inode *inode = mapping->host;
3256 * We can get here for an inline file via the FIBMAP ioctl
3258 if (ext4_has_inline_data(inode))
3261 if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
3262 test_opt(inode->i_sb, DELALLOC)) {
3264 * With delalloc we want to sync the file
3265 * so that we can make sure we allocate
3268 filemap_write_and_wait(mapping);
3271 if (EXT4_JOURNAL(inode) &&
3272 ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {
3274 * This is a REALLY heavyweight approach, but the use of
3275 * bmap on dirty files is expected to be extremely rare:
3276 * only if we run lilo or swapon on a freshly made file
3277 * do we expect this to happen.
3279 * (bmap requires CAP_SYS_RAWIO so this does not
3280 * represent an unprivileged user DOS attack --- we'd be
3281 * in trouble if mortal users could trigger this path at
3284 * NB. EXT4_STATE_JDATA is not set on files other than
3285 * regular files. If somebody wants to bmap a directory
3286 * or symlink and gets confused because the buffer
3287 * hasn't yet been flushed to disk, they deserve
3288 * everything they get.