2 * linux/fs/ext4/inode.c
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
11 * linux/fs/minix/inode.c
13 * Copyright (C) 1991, 1992 Linus Torvalds
15 * 64-bit file support on 64-bit platforms by Jakub Jelinek
16 * (jj@sunsite.ms.mff.cuni.cz)
18 * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
22 #include <linux/time.h>
23 #include <linux/jbd2.h>
24 #include <linux/highuid.h>
25 #include <linux/pagemap.h>
26 #include <linux/quotaops.h>
27 #include <linux/string.h>
28 #include <linux/buffer_head.h>
29 #include <linux/writeback.h>
30 #include <linux/pagevec.h>
31 #include <linux/mpage.h>
32 #include <linux/namei.h>
33 #include <linux/uio.h>
34 #include <linux/bio.h>
35 #include <linux/workqueue.h>
36 #include <linux/kernel.h>
37 #include <linux/printk.h>
38 #include <linux/slab.h>
39 #include <linux/ratelimit.h>
41 #include "ext4_jbd2.h"
46 #include <trace/events/ext4.h>
48 #define MPAGE_DA_EXTENT_TAIL 0x01
50 static inline int ext4_begin_ordered_truncate(struct inode
*inode
,
53 trace_ext4_begin_ordered_truncate(inode
, new_size
);
55 * If jinode is zero, then we never opened the file for
56 * writing, so there's no need to call
57 * jbd2_journal_begin_ordered_truncate() since there's no
58 * outstanding writes we need to flush.
60 if (!EXT4_I(inode
)->jinode
)
62 return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode
),
63 EXT4_I(inode
)->jinode
,
67 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
);
68 static int noalloc_get_block_write(struct inode
*inode
, sector_t iblock
,
69 struct buffer_head
*bh_result
, int create
);
70 static int ext4_set_bh_endio(struct buffer_head
*bh
, struct inode
*inode
);
71 static void ext4_end_io_buffer_write(struct buffer_head
*bh
, int uptodate
);
72 static int __ext4_journalled_writepage(struct page
*page
, unsigned int len
);
73 static int ext4_bh_delay_or_unwritten(handle_t
*handle
, struct buffer_head
*bh
);
74 static int ext4_discard_partial_page_buffers_no_lock(handle_t
*handle
,
75 struct inode
*inode
, struct page
*page
, loff_t from
,
76 loff_t length
, int flags
);
79 * Test whether an inode is a fast symlink.
81 static int ext4_inode_is_fast_symlink(struct inode
*inode
)
83 int ea_blocks
= EXT4_I(inode
)->i_file_acl
?
84 (inode
->i_sb
->s_blocksize
>> 9) : 0;
86 return (S_ISLNK(inode
->i_mode
) && inode
->i_blocks
- ea_blocks
== 0);
90 * Restart the transaction associated with *handle. This does a commit,
91 * so before we call here everything must be consistently dirtied against
94 int ext4_truncate_restart_trans(handle_t
*handle
, struct inode
*inode
,
100 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
101 * moment, get_block can be called only for blocks inside i_size since
102 * page cache has been already dropped and writes are blocked by
103 * i_mutex. So we can safely drop the i_data_sem here.
105 BUG_ON(EXT4_JOURNAL(inode
) == NULL
);
106 jbd_debug(2, "restarting handle %p\n", handle
);
107 up_write(&EXT4_I(inode
)->i_data_sem
);
108 ret
= ext4_journal_restart(handle
, nblocks
);
109 down_write(&EXT4_I(inode
)->i_data_sem
);
110 ext4_discard_preallocations(inode
);
116 * Called at the last iput() if i_nlink is zero.
118 void ext4_evict_inode(struct inode
*inode
)
123 trace_ext4_evict_inode(inode
);
125 ext4_ioend_wait(inode
);
127 if (inode
->i_nlink
) {
129 * When journalling data dirty buffers are tracked only in the
130 * journal. So although mm thinks everything is clean and
131 * ready for reaping the inode might still have some pages to
132 * write in the running transaction or waiting to be
133 * checkpointed. Thus calling jbd2_journal_invalidatepage()
134 * (via truncate_inode_pages()) to discard these buffers can
135 * cause data loss. Also even if we did not discard these
136 * buffers, we would have no way to find them after the inode
137 * is reaped and thus user could see stale data if he tries to
138 * read them before the transaction is checkpointed. So be
139 * careful and force everything to disk here... We use
140 * ei->i_datasync_tid to store the newest transaction
141 * containing inode's data.
143 * Note that directories do not have this problem because they
144 * don't use page cache.
146 if (ext4_should_journal_data(inode
) &&
147 (S_ISLNK(inode
->i_mode
) || S_ISREG(inode
->i_mode
))) {
148 journal_t
*journal
= EXT4_SB(inode
->i_sb
)->s_journal
;
149 tid_t commit_tid
= EXT4_I(inode
)->i_datasync_tid
;
151 jbd2_log_start_commit(journal
, commit_tid
);
152 jbd2_log_wait_commit(journal
, commit_tid
);
153 filemap_write_and_wait(&inode
->i_data
);
155 truncate_inode_pages(&inode
->i_data
, 0);
159 if (!is_bad_inode(inode
))
160 dquot_initialize(inode
);
162 if (ext4_should_order_data(inode
))
163 ext4_begin_ordered_truncate(inode
, 0);
164 truncate_inode_pages(&inode
->i_data
, 0);
166 if (is_bad_inode(inode
))
169 handle
= ext4_journal_start(inode
, ext4_blocks_for_truncate(inode
)+3);
170 if (IS_ERR(handle
)) {
171 ext4_std_error(inode
->i_sb
, PTR_ERR(handle
));
173 * If we're going to skip the normal cleanup, we still need to
174 * make sure that the in-core orphan linked list is properly
177 ext4_orphan_del(NULL
, inode
);
182 ext4_handle_sync(handle
);
184 err
= ext4_mark_inode_dirty(handle
, inode
);
186 ext4_warning(inode
->i_sb
,
187 "couldn't mark inode dirty (err %d)", err
);
191 ext4_truncate(inode
);
194 * ext4_ext_truncate() doesn't reserve any slop when it
195 * restarts journal transactions; therefore there may not be
196 * enough credits left in the handle to remove the inode from
197 * the orphan list and set the dtime field.
199 if (!ext4_handle_has_enough_credits(handle
, 3)) {
200 err
= ext4_journal_extend(handle
, 3);
202 err
= ext4_journal_restart(handle
, 3);
204 ext4_warning(inode
->i_sb
,
205 "couldn't extend journal (err %d)", err
);
207 ext4_journal_stop(handle
);
208 ext4_orphan_del(NULL
, inode
);
214 * Kill off the orphan record which ext4_truncate created.
215 * AKPM: I think this can be inside the above `if'.
216 * Note that ext4_orphan_del() has to be able to cope with the
217 * deletion of a non-existent orphan - this is because we don't
218 * know if ext4_truncate() actually created an orphan record.
219 * (Well, we could do this if we need to, but heck - it works)
221 ext4_orphan_del(handle
, inode
);
222 EXT4_I(inode
)->i_dtime
= get_seconds();
225 * One subtle ordering requirement: if anything has gone wrong
226 * (transaction abort, IO errors, whatever), then we can still
227 * do these next steps (the fs will already have been marked as
228 * having errors), but we can't free the inode if the mark_dirty
231 if (ext4_mark_inode_dirty(handle
, inode
))
232 /* If that failed, just do the required in-core inode clear. */
233 ext4_clear_inode(inode
);
235 ext4_free_inode(handle
, inode
);
236 ext4_journal_stop(handle
);
239 ext4_clear_inode(inode
); /* We must guarantee clearing of inode... */
243 qsize_t
*ext4_get_reserved_space(struct inode
*inode
)
245 return &EXT4_I(inode
)->i_reserved_quota
;
250 * Calculate the number of metadata blocks need to reserve
251 * to allocate a block located at @lblock
253 static int ext4_calc_metadata_amount(struct inode
*inode
, ext4_lblk_t lblock
)
255 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
))
256 return ext4_ext_calc_metadata_amount(inode
, lblock
);
258 return ext4_ind_calc_metadata_amount(inode
, lblock
);
262 * Called with i_data_sem down, which is important since we can call
263 * ext4_discard_preallocations() from here.
265 void ext4_da_update_reserve_space(struct inode
*inode
,
266 int used
, int quota_claim
)
268 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
269 struct ext4_inode_info
*ei
= EXT4_I(inode
);
271 spin_lock(&ei
->i_block_reservation_lock
);
272 trace_ext4_da_update_reserve_space(inode
, used
, quota_claim
);
273 if (unlikely(used
> ei
->i_reserved_data_blocks
)) {
274 ext4_msg(inode
->i_sb
, KERN_NOTICE
, "%s: ino %lu, used %d "
275 "with only %d reserved data blocks",
276 __func__
, inode
->i_ino
, used
,
277 ei
->i_reserved_data_blocks
);
279 used
= ei
->i_reserved_data_blocks
;
282 /* Update per-inode reservations */
283 ei
->i_reserved_data_blocks
-= used
;
284 ei
->i_reserved_meta_blocks
-= ei
->i_allocated_meta_blocks
;
285 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
,
286 used
+ ei
->i_allocated_meta_blocks
);
287 ei
->i_allocated_meta_blocks
= 0;
289 if (ei
->i_reserved_data_blocks
== 0) {
291 * We can release all of the reserved metadata blocks
292 * only when we have written all of the delayed
295 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
,
296 ei
->i_reserved_meta_blocks
);
297 ei
->i_reserved_meta_blocks
= 0;
298 ei
->i_da_metadata_calc_len
= 0;
300 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
302 /* Update quota subsystem for data blocks */
304 dquot_claim_block(inode
, EXT4_C2B(sbi
, used
));
307 * We did fallocate with an offset that is already delayed
308 * allocated. So on delayed allocated writeback we should
309 * not re-claim the quota for fallocated blocks.
311 dquot_release_reservation_block(inode
, EXT4_C2B(sbi
, used
));
315 * If we have done all the pending block allocations and if
316 * there aren't any writers on the inode, we can discard the
317 * inode's preallocations.
319 if ((ei
->i_reserved_data_blocks
== 0) &&
320 (atomic_read(&inode
->i_writecount
) == 0))
321 ext4_discard_preallocations(inode
);
324 static int __check_block_validity(struct inode
*inode
, const char *func
,
326 struct ext4_map_blocks
*map
)
328 if (!ext4_data_block_valid(EXT4_SB(inode
->i_sb
), map
->m_pblk
,
330 ext4_error_inode(inode
, func
, line
, map
->m_pblk
,
331 "lblock %lu mapped to illegal pblock "
332 "(length %d)", (unsigned long) map
->m_lblk
,
339 #define check_block_validity(inode, map) \
340 __check_block_validity((inode), __func__, __LINE__, (map))
343 * Return the number of contiguous dirty pages in a given inode
344 * starting at page frame idx.
346 static pgoff_t
ext4_num_dirty_pages(struct inode
*inode
, pgoff_t idx
,
347 unsigned int max_pages
)
349 struct address_space
*mapping
= inode
->i_mapping
;
353 int i
, nr_pages
, done
= 0;
357 pagevec_init(&pvec
, 0);
360 nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
362 (pgoff_t
)PAGEVEC_SIZE
);
365 for (i
= 0; i
< nr_pages
; i
++) {
366 struct page
*page
= pvec
.pages
[i
];
367 struct buffer_head
*bh
, *head
;
370 if (unlikely(page
->mapping
!= mapping
) ||
372 PageWriteback(page
) ||
373 page
->index
!= idx
) {
378 if (page_has_buffers(page
)) {
379 bh
= head
= page_buffers(page
);
381 if (!buffer_delay(bh
) &&
382 !buffer_unwritten(bh
))
384 bh
= bh
->b_this_page
;
385 } while (!done
&& (bh
!= head
));
392 if (num
>= max_pages
) {
397 pagevec_release(&pvec
);
403 * Sets the BH_Da_Mapped bit on the buffer heads corresponding to the given map.
405 static void set_buffers_da_mapped(struct inode
*inode
,
406 struct ext4_map_blocks
*map
)
408 struct address_space
*mapping
= inode
->i_mapping
;
413 index
= map
->m_lblk
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
414 end
= (map
->m_lblk
+ map
->m_len
- 1) >>
415 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
417 pagevec_init(&pvec
, 0);
418 while (index
<= end
) {
419 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
,
421 (pgoff_t
)PAGEVEC_SIZE
));
424 for (i
= 0; i
< nr_pages
; i
++) {
425 struct page
*page
= pvec
.pages
[i
];
426 struct buffer_head
*bh
, *head
;
428 if (unlikely(page
->mapping
!= mapping
) ||
432 if (page_has_buffers(page
)) {
433 bh
= head
= page_buffers(page
);
435 set_buffer_da_mapped(bh
);
436 bh
= bh
->b_this_page
;
437 } while (bh
!= head
);
441 pagevec_release(&pvec
);
446 * The ext4_map_blocks() function tries to look up the requested blocks,
447 * and returns if the blocks are already mapped.
449 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
450 * and store the allocated blocks in the result buffer head and mark it
453 * If file type is extents based, it will call ext4_ext_map_blocks(),
454 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
457 * On success, it returns the number of blocks being mapped or allocate.
458 * if create==0 and the blocks are pre-allocated and uninitialized block,
459 * the result buffer head is unmapped. If the create ==1, it will make sure
460 * the buffer head is mapped.
462 * It returns 0 if plain look up failed (blocks have not been allocated), in
463 * that case, buffer head is unmapped
465 * It returns the error in case of allocation failure.
467 int ext4_map_blocks(handle_t
*handle
, struct inode
*inode
,
468 struct ext4_map_blocks
*map
, int flags
)
473 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
474 "logical block %lu\n", inode
->i_ino
, flags
, map
->m_len
,
475 (unsigned long) map
->m_lblk
);
477 * Try to see if we can get the block without requesting a new
480 down_read((&EXT4_I(inode
)->i_data_sem
));
481 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) {
482 retval
= ext4_ext_map_blocks(handle
, inode
, map
, flags
&
483 EXT4_GET_BLOCKS_KEEP_SIZE
);
485 retval
= ext4_ind_map_blocks(handle
, inode
, map
, flags
&
486 EXT4_GET_BLOCKS_KEEP_SIZE
);
488 up_read((&EXT4_I(inode
)->i_data_sem
));
490 if (retval
> 0 && map
->m_flags
& EXT4_MAP_MAPPED
) {
491 int ret
= check_block_validity(inode
, map
);
496 /* If it is only a block(s) look up */
497 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0)
501 * Returns if the blocks have already allocated
503 * Note that if blocks have been preallocated
504 * ext4_ext_get_block() returns the create = 0
505 * with buffer head unmapped.
507 if (retval
> 0 && map
->m_flags
& EXT4_MAP_MAPPED
)
511 * When we call get_blocks without the create flag, the
512 * BH_Unwritten flag could have gotten set if the blocks
513 * requested were part of a uninitialized extent. We need to
514 * clear this flag now that we are committed to convert all or
515 * part of the uninitialized extent to be an initialized
516 * extent. This is because we need to avoid the combination
517 * of BH_Unwritten and BH_Mapped flags being simultaneously
518 * set on the buffer_head.
520 map
->m_flags
&= ~EXT4_MAP_UNWRITTEN
;
523 * New blocks allocate and/or writing to uninitialized extent
524 * will possibly result in updating i_data, so we take
525 * the write lock of i_data_sem, and call get_blocks()
526 * with create == 1 flag.
528 down_write((&EXT4_I(inode
)->i_data_sem
));
531 * if the caller is from delayed allocation writeout path
532 * we have already reserved fs blocks for allocation
533 * let the underlying get_block() function know to
534 * avoid double accounting
536 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
537 ext4_set_inode_state(inode
, EXT4_STATE_DELALLOC_RESERVED
);
539 * We need to check for EXT4 here because migrate
540 * could have changed the inode type in between
542 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) {
543 retval
= ext4_ext_map_blocks(handle
, inode
, map
, flags
);
545 retval
= ext4_ind_map_blocks(handle
, inode
, map
, flags
);
547 if (retval
> 0 && map
->m_flags
& EXT4_MAP_NEW
) {
549 * We allocated new blocks which will result in
550 * i_data's format changing. Force the migrate
551 * to fail by clearing migrate flags
553 ext4_clear_inode_state(inode
, EXT4_STATE_EXT_MIGRATE
);
557 * Update reserved blocks/metadata blocks after successful
558 * block allocation which had been deferred till now. We don't
559 * support fallocate for non extent files. So we can update
560 * reserve space here.
563 (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
))
564 ext4_da_update_reserve_space(inode
, retval
, 1);
566 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
) {
567 ext4_clear_inode_state(inode
, EXT4_STATE_DELALLOC_RESERVED
);
569 /* If we have successfully mapped the delayed allocated blocks,
570 * set the BH_Da_Mapped bit on them. Its important to do this
571 * under the protection of i_data_sem.
573 if (retval
> 0 && map
->m_flags
& EXT4_MAP_MAPPED
)
574 set_buffers_da_mapped(inode
, map
);
577 up_write((&EXT4_I(inode
)->i_data_sem
));
578 if (retval
> 0 && map
->m_flags
& EXT4_MAP_MAPPED
) {
579 int ret
= check_block_validity(inode
, map
);
586 /* Maximum number of blocks we map for direct IO at once. */
587 #define DIO_MAX_BLOCKS 4096
589 static int _ext4_get_block(struct inode
*inode
, sector_t iblock
,
590 struct buffer_head
*bh
, int flags
)
592 handle_t
*handle
= ext4_journal_current_handle();
593 struct ext4_map_blocks map
;
594 int ret
= 0, started
= 0;
598 map
.m_len
= bh
->b_size
>> inode
->i_blkbits
;
600 if (flags
&& !handle
) {
601 /* Direct IO write... */
602 if (map
.m_len
> DIO_MAX_BLOCKS
)
603 map
.m_len
= DIO_MAX_BLOCKS
;
604 dio_credits
= ext4_chunk_trans_blocks(inode
, map
.m_len
);
605 handle
= ext4_journal_start(inode
, dio_credits
);
606 if (IS_ERR(handle
)) {
607 ret
= PTR_ERR(handle
);
613 ret
= ext4_map_blocks(handle
, inode
, &map
, flags
);
615 map_bh(bh
, inode
->i_sb
, map
.m_pblk
);
616 bh
->b_state
= (bh
->b_state
& ~EXT4_MAP_FLAGS
) | map
.m_flags
;
617 bh
->b_size
= inode
->i_sb
->s_blocksize
* map
.m_len
;
621 ext4_journal_stop(handle
);
625 int ext4_get_block(struct inode
*inode
, sector_t iblock
,
626 struct buffer_head
*bh
, int create
)
628 return _ext4_get_block(inode
, iblock
, bh
,
629 create
? EXT4_GET_BLOCKS_CREATE
: 0);
633 * `handle' can be NULL if create is zero
635 struct buffer_head
*ext4_getblk(handle_t
*handle
, struct inode
*inode
,
636 ext4_lblk_t block
, int create
, int *errp
)
638 struct ext4_map_blocks map
;
639 struct buffer_head
*bh
;
642 J_ASSERT(handle
!= NULL
|| create
== 0);
646 err
= ext4_map_blocks(handle
, inode
, &map
,
647 create
? EXT4_GET_BLOCKS_CREATE
: 0);
655 bh
= sb_getblk(inode
->i_sb
, map
.m_pblk
);
660 if (map
.m_flags
& EXT4_MAP_NEW
) {
661 J_ASSERT(create
!= 0);
662 J_ASSERT(handle
!= NULL
);
665 * Now that we do not always journal data, we should
666 * keep in mind whether this should always journal the
667 * new buffer as metadata. For now, regular file
668 * writes use ext4_get_block instead, so it's not a
672 BUFFER_TRACE(bh
, "call get_create_access");
673 fatal
= ext4_journal_get_create_access(handle
, bh
);
674 if (!fatal
&& !buffer_uptodate(bh
)) {
675 memset(bh
->b_data
, 0, inode
->i_sb
->s_blocksize
);
676 set_buffer_uptodate(bh
);
679 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
680 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
684 BUFFER_TRACE(bh
, "not a new buffer");
694 struct buffer_head
*ext4_bread(handle_t
*handle
, struct inode
*inode
,
695 ext4_lblk_t block
, int create
, int *err
)
697 struct buffer_head
*bh
;
699 bh
= ext4_getblk(handle
, inode
, block
, create
, err
);
702 if (buffer_uptodate(bh
))
704 ll_rw_block(READ
| REQ_META
| REQ_PRIO
, 1, &bh
);
706 if (buffer_uptodate(bh
))
713 static int walk_page_buffers(handle_t
*handle
,
714 struct buffer_head
*head
,
718 int (*fn
)(handle_t
*handle
,
719 struct buffer_head
*bh
))
721 struct buffer_head
*bh
;
722 unsigned block_start
, block_end
;
723 unsigned blocksize
= head
->b_size
;
725 struct buffer_head
*next
;
727 for (bh
= head
, block_start
= 0;
728 ret
== 0 && (bh
!= head
|| !block_start
);
729 block_start
= block_end
, bh
= next
) {
730 next
= bh
->b_this_page
;
731 block_end
= block_start
+ blocksize
;
732 if (block_end
<= from
|| block_start
>= to
) {
733 if (partial
&& !buffer_uptodate(bh
))
737 err
= (*fn
)(handle
, bh
);
745 * To preserve ordering, it is essential that the hole instantiation and
746 * the data write be encapsulated in a single transaction. We cannot
747 * close off a transaction and start a new one between the ext4_get_block()
748 * and the commit_write(). So doing the jbd2_journal_start at the start of
749 * prepare_write() is the right place.
751 * Also, this function can nest inside ext4_writepage() ->
752 * block_write_full_page(). In that case, we *know* that ext4_writepage()
753 * has generated enough buffer credits to do the whole page. So we won't
754 * block on the journal in that case, which is good, because the caller may
757 * By accident, ext4 can be reentered when a transaction is open via
758 * quota file writes. If we were to commit the transaction while thus
759 * reentered, there can be a deadlock - we would be holding a quota
760 * lock, and the commit would never complete if another thread had a
761 * transaction open and was blocking on the quota lock - a ranking
764 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
765 * will _not_ run commit under these circumstances because handle->h_ref
766 * is elevated. We'll still have enough credits for the tiny quotafile
769 static int do_journal_get_write_access(handle_t
*handle
,
770 struct buffer_head
*bh
)
772 int dirty
= buffer_dirty(bh
);
775 if (!buffer_mapped(bh
) || buffer_freed(bh
))
778 * __block_write_begin() could have dirtied some buffers. Clean
779 * the dirty bit as jbd2_journal_get_write_access() could complain
780 * otherwise about fs integrity issues. Setting of the dirty bit
781 * by __block_write_begin() isn't a real problem here as we clear
782 * the bit before releasing a page lock and thus writeback cannot
783 * ever write the buffer.
786 clear_buffer_dirty(bh
);
787 ret
= ext4_journal_get_write_access(handle
, bh
);
789 ret
= ext4_handle_dirty_metadata(handle
, NULL
, bh
);
793 static int ext4_get_block_write(struct inode
*inode
, sector_t iblock
,
794 struct buffer_head
*bh_result
, int create
);
795 static int ext4_write_begin(struct file
*file
, struct address_space
*mapping
,
796 loff_t pos
, unsigned len
, unsigned flags
,
797 struct page
**pagep
, void **fsdata
)
799 struct inode
*inode
= mapping
->host
;
800 int ret
, needed_blocks
;
807 trace_ext4_write_begin(inode
, pos
, len
, flags
);
809 * Reserve one block more for addition to orphan list in case
810 * we allocate blocks but write fails for some reason
812 needed_blocks
= ext4_writepage_trans_blocks(inode
) + 1;
813 index
= pos
>> PAGE_CACHE_SHIFT
;
814 from
= pos
& (PAGE_CACHE_SIZE
- 1);
818 handle
= ext4_journal_start(inode
, needed_blocks
);
819 if (IS_ERR(handle
)) {
820 ret
= PTR_ERR(handle
);
824 /* We cannot recurse into the filesystem as the transaction is already
826 flags
|= AOP_FLAG_NOFS
;
828 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
830 ext4_journal_stop(handle
);
836 if (ext4_should_dioread_nolock(inode
))
837 ret
= __block_write_begin(page
, pos
, len
, ext4_get_block_write
);
839 ret
= __block_write_begin(page
, pos
, len
, ext4_get_block
);
841 if (!ret
&& ext4_should_journal_data(inode
)) {
842 ret
= walk_page_buffers(handle
, page_buffers(page
),
843 from
, to
, NULL
, do_journal_get_write_access
);
848 page_cache_release(page
);
850 * __block_write_begin may have instantiated a few blocks
851 * outside i_size. Trim these off again. Don't need
852 * i_size_read because we hold i_mutex.
854 * Add inode to orphan list in case we crash before
857 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
858 ext4_orphan_add(handle
, inode
);
860 ext4_journal_stop(handle
);
861 if (pos
+ len
> inode
->i_size
) {
862 ext4_truncate_failed_write(inode
);
864 * If truncate failed early the inode might
865 * still be on the orphan list; we need to
866 * make sure the inode is removed from the
867 * orphan list in that case.
870 ext4_orphan_del(NULL
, inode
);
874 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
880 /* For write_end() in data=journal mode */
881 static int write_end_fn(handle_t
*handle
, struct buffer_head
*bh
)
883 if (!buffer_mapped(bh
) || buffer_freed(bh
))
885 set_buffer_uptodate(bh
);
886 return ext4_handle_dirty_metadata(handle
, NULL
, bh
);
889 static int ext4_generic_write_end(struct file
*file
,
890 struct address_space
*mapping
,
891 loff_t pos
, unsigned len
, unsigned copied
,
892 struct page
*page
, void *fsdata
)
894 int i_size_changed
= 0;
895 struct inode
*inode
= mapping
->host
;
896 handle_t
*handle
= ext4_journal_current_handle();
898 copied
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
901 * No need to use i_size_read() here, the i_size
902 * cannot change under us because we hold i_mutex.
904 * But it's important to update i_size while still holding page lock:
905 * page writeout could otherwise come in and zero beyond i_size.
907 if (pos
+ copied
> inode
->i_size
) {
908 i_size_write(inode
, pos
+ copied
);
912 if (pos
+ copied
> EXT4_I(inode
)->i_disksize
) {
913 /* We need to mark inode dirty even if
914 * new_i_size is less that inode->i_size
915 * bu greater than i_disksize.(hint delalloc)
917 ext4_update_i_disksize(inode
, (pos
+ copied
));
921 page_cache_release(page
);
924 * Don't mark the inode dirty under page lock. First, it unnecessarily
925 * makes the holding time of page lock longer. Second, it forces lock
926 * ordering of page lock and transaction start for journaling
930 ext4_mark_inode_dirty(handle
, inode
);
936 * We need to pick up the new inode size which generic_commit_write gave us
937 * `file' can be NULL - eg, when called from page_symlink().
939 * ext4 never places buffers on inode->i_mapping->private_list. metadata
940 * buffers are managed internally.
942 static int ext4_ordered_write_end(struct file
*file
,
943 struct address_space
*mapping
,
944 loff_t pos
, unsigned len
, unsigned copied
,
945 struct page
*page
, void *fsdata
)
947 handle_t
*handle
= ext4_journal_current_handle();
948 struct inode
*inode
= mapping
->host
;
951 trace_ext4_ordered_write_end(inode
, pos
, len
, copied
);
952 ret
= ext4_jbd2_file_inode(handle
, inode
);
955 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
958 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
959 /* if we have allocated more blocks and copied
960 * less. We will have blocks allocated outside
961 * inode->i_size. So truncate them
963 ext4_orphan_add(handle
, inode
);
968 page_cache_release(page
);
971 ret2
= ext4_journal_stop(handle
);
975 if (pos
+ len
> inode
->i_size
) {
976 ext4_truncate_failed_write(inode
);
978 * If truncate failed early the inode might still be
979 * on the orphan list; we need to make sure the inode
980 * is removed from the orphan list in that case.
983 ext4_orphan_del(NULL
, inode
);
987 return ret
? ret
: copied
;
990 static int ext4_writeback_write_end(struct file
*file
,
991 struct address_space
*mapping
,
992 loff_t pos
, unsigned len
, unsigned copied
,
993 struct page
*page
, void *fsdata
)
995 handle_t
*handle
= ext4_journal_current_handle();
996 struct inode
*inode
= mapping
->host
;
999 trace_ext4_writeback_write_end(inode
, pos
, len
, copied
);
1000 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1003 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1004 /* if we have allocated more blocks and copied
1005 * less. We will have blocks allocated outside
1006 * inode->i_size. So truncate them
1008 ext4_orphan_add(handle
, inode
);
1013 ret2
= ext4_journal_stop(handle
);
1017 if (pos
+ len
> inode
->i_size
) {
1018 ext4_truncate_failed_write(inode
);
1020 * If truncate failed early the inode might still be
1021 * on the orphan list; we need to make sure the inode
1022 * is removed from the orphan list in that case.
1025 ext4_orphan_del(NULL
, inode
);
1028 return ret
? ret
: copied
;
1031 static int ext4_journalled_write_end(struct file
*file
,
1032 struct address_space
*mapping
,
1033 loff_t pos
, unsigned len
, unsigned copied
,
1034 struct page
*page
, void *fsdata
)
1036 handle_t
*handle
= ext4_journal_current_handle();
1037 struct inode
*inode
= mapping
->host
;
1043 trace_ext4_journalled_write_end(inode
, pos
, len
, copied
);
1044 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1047 BUG_ON(!ext4_handle_valid(handle
));
1050 if (!PageUptodate(page
))
1052 page_zero_new_buffers(page
, from
+copied
, to
);
1055 ret
= walk_page_buffers(handle
, page_buffers(page
), from
,
1056 to
, &partial
, write_end_fn
);
1058 SetPageUptodate(page
);
1059 new_i_size
= pos
+ copied
;
1060 if (new_i_size
> inode
->i_size
)
1061 i_size_write(inode
, pos
+copied
);
1062 ext4_set_inode_state(inode
, EXT4_STATE_JDATA
);
1063 EXT4_I(inode
)->i_datasync_tid
= handle
->h_transaction
->t_tid
;
1064 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1065 ext4_update_i_disksize(inode
, new_i_size
);
1066 ret2
= ext4_mark_inode_dirty(handle
, inode
);
1072 page_cache_release(page
);
1073 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1074 /* if we have allocated more blocks and copied
1075 * less. We will have blocks allocated outside
1076 * inode->i_size. So truncate them
1078 ext4_orphan_add(handle
, inode
);
1080 ret2
= ext4_journal_stop(handle
);
1083 if (pos
+ len
> inode
->i_size
) {
1084 ext4_truncate_failed_write(inode
);
1086 * If truncate failed early the inode might still be
1087 * on the orphan list; we need to make sure the inode
1088 * is removed from the orphan list in that case.
1091 ext4_orphan_del(NULL
, inode
);
1094 return ret
? ret
: copied
;
1098 * Reserve a single cluster located at lblock
1100 static int ext4_da_reserve_space(struct inode
*inode
, ext4_lblk_t lblock
)
1103 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1104 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1105 unsigned int md_needed
;
1109 * recalculate the amount of metadata blocks to reserve
1110 * in order to allocate nrblocks
1111 * worse case is one extent per block
1114 spin_lock(&ei
->i_block_reservation_lock
);
1115 md_needed
= EXT4_NUM_B2C(sbi
,
1116 ext4_calc_metadata_amount(inode
, lblock
));
1117 trace_ext4_da_reserve_space(inode
, md_needed
);
1118 spin_unlock(&ei
->i_block_reservation_lock
);
1121 * We will charge metadata quota at writeout time; this saves
1122 * us from metadata over-estimation, though we may go over by
1123 * a small amount in the end. Here we just reserve for data.
1125 ret
= dquot_reserve_block(inode
, EXT4_C2B(sbi
, 1));
1129 * We do still charge estimated metadata to the sb though;
1130 * we cannot afford to run out of free blocks.
1132 if (ext4_claim_free_clusters(sbi
, md_needed
+ 1, 0)) {
1133 dquot_release_reservation_block(inode
, EXT4_C2B(sbi
, 1));
1134 if (ext4_should_retry_alloc(inode
->i_sb
, &retries
)) {
1140 spin_lock(&ei
->i_block_reservation_lock
);
1141 ei
->i_reserved_data_blocks
++;
1142 ei
->i_reserved_meta_blocks
+= md_needed
;
1143 spin_unlock(&ei
->i_block_reservation_lock
);
1145 return 0; /* success */
1148 static void ext4_da_release_space(struct inode
*inode
, int to_free
)
1150 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1151 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1154 return; /* Nothing to release, exit */
1156 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1158 trace_ext4_da_release_space(inode
, to_free
);
1159 if (unlikely(to_free
> ei
->i_reserved_data_blocks
)) {
1161 * if there aren't enough reserved blocks, then the
1162 * counter is messed up somewhere. Since this
1163 * function is called from invalidate page, it's
1164 * harmless to return without any action.
1166 ext4_msg(inode
->i_sb
, KERN_NOTICE
, "ext4_da_release_space: "
1167 "ino %lu, to_free %d with only %d reserved "
1168 "data blocks", inode
->i_ino
, to_free
,
1169 ei
->i_reserved_data_blocks
);
1171 to_free
= ei
->i_reserved_data_blocks
;
1173 ei
->i_reserved_data_blocks
-= to_free
;
1175 if (ei
->i_reserved_data_blocks
== 0) {
1177 * We can release all of the reserved metadata blocks
1178 * only when we have written all of the delayed
1179 * allocation blocks.
1180 * Note that in case of bigalloc, i_reserved_meta_blocks,
1181 * i_reserved_data_blocks, etc. refer to number of clusters.
1183 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
,
1184 ei
->i_reserved_meta_blocks
);
1185 ei
->i_reserved_meta_blocks
= 0;
1186 ei
->i_da_metadata_calc_len
= 0;
1189 /* update fs dirty data blocks counter */
1190 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
, to_free
);
1192 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1194 dquot_release_reservation_block(inode
, EXT4_C2B(sbi
, to_free
));
1197 static void ext4_da_page_release_reservation(struct page
*page
,
1198 unsigned long offset
)
1201 struct buffer_head
*head
, *bh
;
1202 unsigned int curr_off
= 0;
1203 struct inode
*inode
= page
->mapping
->host
;
1204 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1207 head
= page_buffers(page
);
1210 unsigned int next_off
= curr_off
+ bh
->b_size
;
1212 if ((offset
<= curr_off
) && (buffer_delay(bh
))) {
1214 clear_buffer_delay(bh
);
1215 clear_buffer_da_mapped(bh
);
1217 curr_off
= next_off
;
1218 } while ((bh
= bh
->b_this_page
) != head
);
1220 /* If we have released all the blocks belonging to a cluster, then we
1221 * need to release the reserved space for that cluster. */
1222 num_clusters
= EXT4_NUM_B2C(sbi
, to_release
);
1223 while (num_clusters
> 0) {
1225 lblk
= (page
->index
<< (PAGE_CACHE_SHIFT
- inode
->i_blkbits
)) +
1226 ((num_clusters
- 1) << sbi
->s_cluster_bits
);
1227 if (sbi
->s_cluster_ratio
== 1 ||
1228 !ext4_find_delalloc_cluster(inode
, lblk
, 1))
1229 ext4_da_release_space(inode
, 1);
1236 * Delayed allocation stuff
1240 * mpage_da_submit_io - walks through extent of pages and try to write
1241 * them with writepage() call back
1243 * @mpd->inode: inode
1244 * @mpd->first_page: first page of the extent
1245 * @mpd->next_page: page after the last page of the extent
1247 * By the time mpage_da_submit_io() is called we expect all blocks
1248 * to be allocated. this may be wrong if allocation failed.
1250 * As pages are already locked by write_cache_pages(), we can't use it
1252 static int mpage_da_submit_io(struct mpage_da_data
*mpd
,
1253 struct ext4_map_blocks
*map
)
1255 struct pagevec pvec
;
1256 unsigned long index
, end
;
1257 int ret
= 0, err
, nr_pages
, i
;
1258 struct inode
*inode
= mpd
->inode
;
1259 struct address_space
*mapping
= inode
->i_mapping
;
1260 loff_t size
= i_size_read(inode
);
1261 unsigned int len
, block_start
;
1262 struct buffer_head
*bh
, *page_bufs
= NULL
;
1263 int journal_data
= ext4_should_journal_data(inode
);
1264 sector_t pblock
= 0, cur_logical
= 0;
1265 struct ext4_io_submit io_submit
;
1267 BUG_ON(mpd
->next_page
<= mpd
->first_page
);
1268 memset(&io_submit
, 0, sizeof(io_submit
));
1270 * We need to start from the first_page to the next_page - 1
1271 * to make sure we also write the mapped dirty buffer_heads.
1272 * If we look at mpd->b_blocknr we would only be looking
1273 * at the currently mapped buffer_heads.
1275 index
= mpd
->first_page
;
1276 end
= mpd
->next_page
- 1;
1278 pagevec_init(&pvec
, 0);
1279 while (index
<= end
) {
1280 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1283 for (i
= 0; i
< nr_pages
; i
++) {
1284 int commit_write
= 0, skip_page
= 0;
1285 struct page
*page
= pvec
.pages
[i
];
1287 index
= page
->index
;
1291 if (index
== size
>> PAGE_CACHE_SHIFT
)
1292 len
= size
& ~PAGE_CACHE_MASK
;
1294 len
= PAGE_CACHE_SIZE
;
1296 cur_logical
= index
<< (PAGE_CACHE_SHIFT
-
1298 pblock
= map
->m_pblk
+ (cur_logical
-
1303 BUG_ON(!PageLocked(page
));
1304 BUG_ON(PageWriteback(page
));
1307 * If the page does not have buffers (for
1308 * whatever reason), try to create them using
1309 * __block_write_begin. If this fails,
1310 * skip the page and move on.
1312 if (!page_has_buffers(page
)) {
1313 if (__block_write_begin(page
, 0, len
,
1314 noalloc_get_block_write
)) {
1322 bh
= page_bufs
= page_buffers(page
);
1327 if (map
&& (cur_logical
>= map
->m_lblk
) &&
1328 (cur_logical
<= (map
->m_lblk
+
1329 (map
->m_len
- 1)))) {
1330 if (buffer_delay(bh
)) {
1331 clear_buffer_delay(bh
);
1332 bh
->b_blocknr
= pblock
;
1334 if (buffer_da_mapped(bh
))
1335 clear_buffer_da_mapped(bh
);
1336 if (buffer_unwritten(bh
) ||
1338 BUG_ON(bh
->b_blocknr
!= pblock
);
1339 if (map
->m_flags
& EXT4_MAP_UNINIT
)
1340 set_buffer_uninit(bh
);
1341 clear_buffer_unwritten(bh
);
1345 * skip page if block allocation undone and
1348 if (ext4_bh_delay_or_unwritten(NULL
, bh
))
1350 bh
= bh
->b_this_page
;
1351 block_start
+= bh
->b_size
;
1354 } while (bh
!= page_bufs
);
1360 /* mark the buffer_heads as dirty & uptodate */
1361 block_commit_write(page
, 0, len
);
1363 clear_page_dirty_for_io(page
);
1365 * Delalloc doesn't support data journalling,
1366 * but eventually maybe we'll lift this
1369 if (unlikely(journal_data
&& PageChecked(page
)))
1370 err
= __ext4_journalled_writepage(page
, len
);
1371 else if (test_opt(inode
->i_sb
, MBLK_IO_SUBMIT
))
1372 err
= ext4_bio_write_page(&io_submit
, page
,
1374 else if (buffer_uninit(page_bufs
)) {
1375 ext4_set_bh_endio(page_bufs
, inode
);
1376 err
= block_write_full_page_endio(page
,
1377 noalloc_get_block_write
,
1378 mpd
->wbc
, ext4_end_io_buffer_write
);
1380 err
= block_write_full_page(page
,
1381 noalloc_get_block_write
, mpd
->wbc
);
1384 mpd
->pages_written
++;
1386 * In error case, we have to continue because
1387 * remaining pages are still locked
1392 pagevec_release(&pvec
);
1394 ext4_io_submit(&io_submit
);
1398 static void ext4_da_block_invalidatepages(struct mpage_da_data
*mpd
)
1402 struct pagevec pvec
;
1403 struct inode
*inode
= mpd
->inode
;
1404 struct address_space
*mapping
= inode
->i_mapping
;
1406 index
= mpd
->first_page
;
1407 end
= mpd
->next_page
- 1;
1408 while (index
<= end
) {
1409 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1412 for (i
= 0; i
< nr_pages
; i
++) {
1413 struct page
*page
= pvec
.pages
[i
];
1414 if (page
->index
> end
)
1416 BUG_ON(!PageLocked(page
));
1417 BUG_ON(PageWriteback(page
));
1418 block_invalidatepage(page
, 0);
1419 ClearPageUptodate(page
);
1422 index
= pvec
.pages
[nr_pages
- 1]->index
+ 1;
1423 pagevec_release(&pvec
);
1428 static void ext4_print_free_blocks(struct inode
*inode
)
1430 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1431 struct super_block
*sb
= inode
->i_sb
;
1433 ext4_msg(sb
, KERN_CRIT
, "Total free blocks count %lld",
1434 EXT4_C2B(EXT4_SB(inode
->i_sb
),
1435 ext4_count_free_clusters(inode
->i_sb
)));
1436 ext4_msg(sb
, KERN_CRIT
, "Free/Dirty block details");
1437 ext4_msg(sb
, KERN_CRIT
, "free_blocks=%lld",
1438 (long long) EXT4_C2B(EXT4_SB(inode
->i_sb
),
1439 percpu_counter_sum(&sbi
->s_freeclusters_counter
)));
1440 ext4_msg(sb
, KERN_CRIT
, "dirty_blocks=%lld",
1441 (long long) EXT4_C2B(EXT4_SB(inode
->i_sb
),
1442 percpu_counter_sum(&sbi
->s_dirtyclusters_counter
)));
1443 ext4_msg(sb
, KERN_CRIT
, "Block reservation details");
1444 ext4_msg(sb
, KERN_CRIT
, "i_reserved_data_blocks=%u",
1445 EXT4_I(inode
)->i_reserved_data_blocks
);
1446 ext4_msg(sb
, KERN_CRIT
, "i_reserved_meta_blocks=%u",
1447 EXT4_I(inode
)->i_reserved_meta_blocks
);
1452 * mpage_da_map_and_submit - go through given space, map them
1453 * if necessary, and then submit them for I/O
1455 * @mpd - bh describing space
1457 * The function skips space we know is already mapped to disk blocks.
1460 static void mpage_da_map_and_submit(struct mpage_da_data
*mpd
)
1462 int err
, blks
, get_blocks_flags
;
1463 struct ext4_map_blocks map
, *mapp
= NULL
;
1464 sector_t next
= mpd
->b_blocknr
;
1465 unsigned max_blocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
1466 loff_t disksize
= EXT4_I(mpd
->inode
)->i_disksize
;
1467 handle_t
*handle
= NULL
;
1470 * If the blocks are mapped already, or we couldn't accumulate
1471 * any blocks, then proceed immediately to the submission stage.
1473 if ((mpd
->b_size
== 0) ||
1474 ((mpd
->b_state
& (1 << BH_Mapped
)) &&
1475 !(mpd
->b_state
& (1 << BH_Delay
)) &&
1476 !(mpd
->b_state
& (1 << BH_Unwritten
))))
1479 handle
= ext4_journal_current_handle();
1483 * Call ext4_map_blocks() to allocate any delayed allocation
1484 * blocks, or to convert an uninitialized extent to be
1485 * initialized (in the case where we have written into
1486 * one or more preallocated blocks).
1488 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
1489 * indicate that we are on the delayed allocation path. This
1490 * affects functions in many different parts of the allocation
1491 * call path. This flag exists primarily because we don't
1492 * want to change *many* call functions, so ext4_map_blocks()
1493 * will set the EXT4_STATE_DELALLOC_RESERVED flag once the
1494 * inode's allocation semaphore is taken.
1496 * If the blocks in questions were delalloc blocks, set
1497 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
1498 * variables are updated after the blocks have been allocated.
1501 map
.m_len
= max_blocks
;
1502 get_blocks_flags
= EXT4_GET_BLOCKS_CREATE
;
1503 if (ext4_should_dioread_nolock(mpd
->inode
))
1504 get_blocks_flags
|= EXT4_GET_BLOCKS_IO_CREATE_EXT
;
1505 if (mpd
->b_state
& (1 << BH_Delay
))
1506 get_blocks_flags
|= EXT4_GET_BLOCKS_DELALLOC_RESERVE
;
1508 blks
= ext4_map_blocks(handle
, mpd
->inode
, &map
, get_blocks_flags
);
1510 struct super_block
*sb
= mpd
->inode
->i_sb
;
1514 * If get block returns EAGAIN or ENOSPC and there
1515 * appears to be free blocks we will just let
1516 * mpage_da_submit_io() unlock all of the pages.
1521 if (err
== -ENOSPC
&& ext4_count_free_clusters(sb
)) {
1527 * get block failure will cause us to loop in
1528 * writepages, because a_ops->writepage won't be able
1529 * to make progress. The page will be redirtied by
1530 * writepage and writepages will again try to write
1533 if (!(EXT4_SB(sb
)->s_mount_flags
& EXT4_MF_FS_ABORTED
)) {
1534 ext4_msg(sb
, KERN_CRIT
,
1535 "delayed block allocation failed for inode %lu "
1536 "at logical offset %llu with max blocks %zd "
1537 "with error %d", mpd
->inode
->i_ino
,
1538 (unsigned long long) next
,
1539 mpd
->b_size
>> mpd
->inode
->i_blkbits
, err
);
1540 ext4_msg(sb
, KERN_CRIT
,
1541 "This should not happen!! Data will be lost\n");
1543 ext4_print_free_blocks(mpd
->inode
);
1545 /* invalidate all the pages */
1546 ext4_da_block_invalidatepages(mpd
);
1548 /* Mark this page range as having been completed */
1555 if (map
.m_flags
& EXT4_MAP_NEW
) {
1556 struct block_device
*bdev
= mpd
->inode
->i_sb
->s_bdev
;
1559 for (i
= 0; i
< map
.m_len
; i
++)
1560 unmap_underlying_metadata(bdev
, map
.m_pblk
+ i
);
1562 if (ext4_should_order_data(mpd
->inode
)) {
1563 err
= ext4_jbd2_file_inode(handle
, mpd
->inode
);
1565 /* Only if the journal is aborted */
1573 * Update on-disk size along with block allocation.
1575 disksize
= ((loff_t
) next
+ blks
) << mpd
->inode
->i_blkbits
;
1576 if (disksize
> i_size_read(mpd
->inode
))
1577 disksize
= i_size_read(mpd
->inode
);
1578 if (disksize
> EXT4_I(mpd
->inode
)->i_disksize
) {
1579 ext4_update_i_disksize(mpd
->inode
, disksize
);
1580 err
= ext4_mark_inode_dirty(handle
, mpd
->inode
);
1582 ext4_error(mpd
->inode
->i_sb
,
1583 "Failed to mark inode %lu dirty",
1588 mpage_da_submit_io(mpd
, mapp
);
1592 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
1593 (1 << BH_Delay) | (1 << BH_Unwritten))
1596 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
1598 * @mpd->lbh - extent of blocks
1599 * @logical - logical number of the block in the file
1600 * @bh - bh of the block (used to access block's state)
1602 * the function is used to collect contig. blocks in same state
1604 static void mpage_add_bh_to_extent(struct mpage_da_data
*mpd
,
1605 sector_t logical
, size_t b_size
,
1606 unsigned long b_state
)
1609 int nrblocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
1612 * XXX Don't go larger than mballoc is willing to allocate
1613 * This is a stopgap solution. We eventually need to fold
1614 * mpage_da_submit_io() into this function and then call
1615 * ext4_map_blocks() multiple times in a loop
1617 if (nrblocks
>= 8*1024*1024/mpd
->inode
->i_sb
->s_blocksize
)
1620 /* check if thereserved journal credits might overflow */
1621 if (!(ext4_test_inode_flag(mpd
->inode
, EXT4_INODE_EXTENTS
))) {
1622 if (nrblocks
>= EXT4_MAX_TRANS_DATA
) {
1624 * With non-extent format we are limited by the journal
1625 * credit available. Total credit needed to insert
1626 * nrblocks contiguous blocks is dependent on the
1627 * nrblocks. So limit nrblocks.
1630 } else if ((nrblocks
+ (b_size
>> mpd
->inode
->i_blkbits
)) >
1631 EXT4_MAX_TRANS_DATA
) {
1633 * Adding the new buffer_head would make it cross the
1634 * allowed limit for which we have journal credit
1635 * reserved. So limit the new bh->b_size
1637 b_size
= (EXT4_MAX_TRANS_DATA
- nrblocks
) <<
1638 mpd
->inode
->i_blkbits
;
1639 /* we will do mpage_da_submit_io in the next loop */
1643 * First block in the extent
1645 if (mpd
->b_size
== 0) {
1646 mpd
->b_blocknr
= logical
;
1647 mpd
->b_size
= b_size
;
1648 mpd
->b_state
= b_state
& BH_FLAGS
;
1652 next
= mpd
->b_blocknr
+ nrblocks
;
1654 * Can we merge the block to our big extent?
1656 if (logical
== next
&& (b_state
& BH_FLAGS
) == mpd
->b_state
) {
1657 mpd
->b_size
+= b_size
;
1663 * We couldn't merge the block to our extent, so we
1664 * need to flush current extent and start new one
1666 mpage_da_map_and_submit(mpd
);
1670 static int ext4_bh_delay_or_unwritten(handle_t
*handle
, struct buffer_head
*bh
)
1672 return (buffer_delay(bh
) || buffer_unwritten(bh
)) && buffer_dirty(bh
);
1676 * This function is grabs code from the very beginning of
1677 * ext4_map_blocks, but assumes that the caller is from delayed write
1678 * time. This function looks up the requested blocks and sets the
1679 * buffer delay bit under the protection of i_data_sem.
1681 static int ext4_da_map_blocks(struct inode
*inode
, sector_t iblock
,
1682 struct ext4_map_blocks
*map
,
1683 struct buffer_head
*bh
)
1686 sector_t invalid_block
= ~((sector_t
) 0xffff);
1688 if (invalid_block
< ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
))
1692 ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u,"
1693 "logical block %lu\n", inode
->i_ino
, map
->m_len
,
1694 (unsigned long) map
->m_lblk
);
1696 * Try to see if we can get the block without requesting a new
1697 * file system block.
1699 down_read((&EXT4_I(inode
)->i_data_sem
));
1700 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
))
1701 retval
= ext4_ext_map_blocks(NULL
, inode
, map
, 0);
1703 retval
= ext4_ind_map_blocks(NULL
, inode
, map
, 0);
1707 * XXX: __block_prepare_write() unmaps passed block,
1710 /* If the block was allocated from previously allocated cluster,
1711 * then we dont need to reserve it again. */
1712 if (!(map
->m_flags
& EXT4_MAP_FROM_CLUSTER
)) {
1713 retval
= ext4_da_reserve_space(inode
, iblock
);
1715 /* not enough space to reserve */
1719 /* Clear EXT4_MAP_FROM_CLUSTER flag since its purpose is served
1720 * and it should not appear on the bh->b_state.
1722 map
->m_flags
&= ~EXT4_MAP_FROM_CLUSTER
;
1724 map_bh(bh
, inode
->i_sb
, invalid_block
);
1726 set_buffer_delay(bh
);
1730 up_read((&EXT4_I(inode
)->i_data_sem
));
1736 * This is a special get_blocks_t callback which is used by
1737 * ext4_da_write_begin(). It will either return mapped block or
1738 * reserve space for a single block.
1740 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
1741 * We also have b_blocknr = -1 and b_bdev initialized properly
1743 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
1744 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
1745 * initialized properly.
1747 static int ext4_da_get_block_prep(struct inode
*inode
, sector_t iblock
,
1748 struct buffer_head
*bh
, int create
)
1750 struct ext4_map_blocks map
;
1753 BUG_ON(create
== 0);
1754 BUG_ON(bh
->b_size
!= inode
->i_sb
->s_blocksize
);
1756 map
.m_lblk
= iblock
;
1760 * first, we need to know whether the block is allocated already
1761 * preallocated blocks are unmapped but should treated
1762 * the same as allocated blocks.
1764 ret
= ext4_da_map_blocks(inode
, iblock
, &map
, bh
);
1768 map_bh(bh
, inode
->i_sb
, map
.m_pblk
);
1769 bh
->b_state
= (bh
->b_state
& ~EXT4_MAP_FLAGS
) | map
.m_flags
;
1771 if (buffer_unwritten(bh
)) {
1772 /* A delayed write to unwritten bh should be marked
1773 * new and mapped. Mapped ensures that we don't do
1774 * get_block multiple times when we write to the same
1775 * offset and new ensures that we do proper zero out
1776 * for partial write.
1779 set_buffer_mapped(bh
);
1785 * This function is used as a standard get_block_t calback function
1786 * when there is no desire to allocate any blocks. It is used as a
1787 * callback function for block_write_begin() and block_write_full_page().
1788 * These functions should only try to map a single block at a time.
1790 * Since this function doesn't do block allocations even if the caller
1791 * requests it by passing in create=1, it is critically important that
1792 * any caller checks to make sure that any buffer heads are returned
1793 * by this function are either all already mapped or marked for
1794 * delayed allocation before calling block_write_full_page(). Otherwise,
1795 * b_blocknr could be left unitialized, and the page write functions will
1796 * be taken by surprise.
1798 static int noalloc_get_block_write(struct inode
*inode
, sector_t iblock
,
1799 struct buffer_head
*bh_result
, int create
)
1801 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
1802 return _ext4_get_block(inode
, iblock
, bh_result
, 0);
1805 static int bget_one(handle_t
*handle
, struct buffer_head
*bh
)
1811 static int bput_one(handle_t
*handle
, struct buffer_head
*bh
)
1817 static int __ext4_journalled_writepage(struct page
*page
,
1820 struct address_space
*mapping
= page
->mapping
;
1821 struct inode
*inode
= mapping
->host
;
1822 struct buffer_head
*page_bufs
;
1823 handle_t
*handle
= NULL
;
1827 ClearPageChecked(page
);
1828 page_bufs
= page_buffers(page
);
1830 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bget_one
);
1831 /* As soon as we unlock the page, it can go away, but we have
1832 * references to buffers so we are safe */
1835 handle
= ext4_journal_start(inode
, ext4_writepage_trans_blocks(inode
));
1836 if (IS_ERR(handle
)) {
1837 ret
= PTR_ERR(handle
);
1841 BUG_ON(!ext4_handle_valid(handle
));
1843 ret
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
1844 do_journal_get_write_access
);
1846 err
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
1850 EXT4_I(inode
)->i_datasync_tid
= handle
->h_transaction
->t_tid
;
1851 err
= ext4_journal_stop(handle
);
1855 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bput_one
);
1856 ext4_set_inode_state(inode
, EXT4_STATE_JDATA
);
1861 static int ext4_set_bh_endio(struct buffer_head
*bh
, struct inode
*inode
);
1862 static void ext4_end_io_buffer_write(struct buffer_head
*bh
, int uptodate
);
1865 * Note that we don't need to start a transaction unless we're journaling data
1866 * because we should have holes filled from ext4_page_mkwrite(). We even don't
1867 * need to file the inode to the transaction's list in ordered mode because if
1868 * we are writing back data added by write(), the inode is already there and if
1869 * we are writing back data modified via mmap(), no one guarantees in which
1870 * transaction the data will hit the disk. In case we are journaling data, we
1871 * cannot start transaction directly because transaction start ranks above page
1872 * lock so we have to do some magic.
1874 * This function can get called via...
1875 * - ext4_da_writepages after taking page lock (have journal handle)
1876 * - journal_submit_inode_data_buffers (no journal handle)
1877 * - shrink_page_list via pdflush (no journal handle)
1878 * - grab_page_cache when doing write_begin (have journal handle)
1880 * We don't do any block allocation in this function. If we have page with
1881 * multiple blocks we need to write those buffer_heads that are mapped. This
1882 * is important for mmaped based write. So if we do with blocksize 1K
1883 * truncate(f, 1024);
1884 * a = mmap(f, 0, 4096);
1886 * truncate(f, 4096);
1887 * we have in the page first buffer_head mapped via page_mkwrite call back
1888 * but other buffer_heads would be unmapped but dirty (dirty done via the
1889 * do_wp_page). So writepage should write the first block. If we modify
1890 * the mmap area beyond 1024 we will again get a page_fault and the
1891 * page_mkwrite callback will do the block allocation and mark the
1892 * buffer_heads mapped.
1894 * We redirty the page if we have any buffer_heads that is either delay or
1895 * unwritten in the page.
1897 * We can get recursively called as show below.
1899 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1902 * But since we don't do any block allocation we should not deadlock.
1903 * Page also have the dirty flag cleared so we don't get recurive page_lock.
1905 static int ext4_writepage(struct page
*page
,
1906 struct writeback_control
*wbc
)
1908 int ret
= 0, commit_write
= 0;
1911 struct buffer_head
*page_bufs
= NULL
;
1912 struct inode
*inode
= page
->mapping
->host
;
1914 trace_ext4_writepage(page
);
1915 size
= i_size_read(inode
);
1916 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
1917 len
= size
& ~PAGE_CACHE_MASK
;
1919 len
= PAGE_CACHE_SIZE
;
1922 * If the page does not have buffers (for whatever reason),
1923 * try to create them using __block_write_begin. If this
1924 * fails, redirty the page and move on.
1926 if (!page_has_buffers(page
)) {
1927 if (__block_write_begin(page
, 0, len
,
1928 noalloc_get_block_write
)) {
1930 redirty_page_for_writepage(wbc
, page
);
1936 page_bufs
= page_buffers(page
);
1937 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
1938 ext4_bh_delay_or_unwritten
)) {
1940 * We don't want to do block allocation, so redirty
1941 * the page and return. We may reach here when we do
1942 * a journal commit via journal_submit_inode_data_buffers.
1943 * We can also reach here via shrink_page_list but it
1944 * should never be for direct reclaim so warn if that
1947 WARN_ON_ONCE((current
->flags
& (PF_MEMALLOC
|PF_KSWAPD
)) ==
1952 /* now mark the buffer_heads as dirty and uptodate */
1953 block_commit_write(page
, 0, len
);
1955 if (PageChecked(page
) && ext4_should_journal_data(inode
))
1957 * It's mmapped pagecache. Add buffers and journal it. There
1958 * doesn't seem much point in redirtying the page here.
1960 return __ext4_journalled_writepage(page
, len
);
1962 if (buffer_uninit(page_bufs
)) {
1963 ext4_set_bh_endio(page_bufs
, inode
);
1964 ret
= block_write_full_page_endio(page
, noalloc_get_block_write
,
1965 wbc
, ext4_end_io_buffer_write
);
1967 ret
= block_write_full_page(page
, noalloc_get_block_write
,
1974 * This is called via ext4_da_writepages() to
1975 * calculate the total number of credits to reserve to fit
1976 * a single extent allocation into a single transaction,
1977 * ext4_da_writpeages() will loop calling this before
1978 * the block allocation.
1981 static int ext4_da_writepages_trans_blocks(struct inode
*inode
)
1983 int max_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
1986 * With non-extent format the journal credit needed to
1987 * insert nrblocks contiguous block is dependent on
1988 * number of contiguous block. So we will limit
1989 * number of contiguous block to a sane value
1991 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) &&
1992 (max_blocks
> EXT4_MAX_TRANS_DATA
))
1993 max_blocks
= EXT4_MAX_TRANS_DATA
;
1995 return ext4_chunk_trans_blocks(inode
, max_blocks
);
1999 * write_cache_pages_da - walk the list of dirty pages of the given
2000 * address space and accumulate pages that need writing, and call
2001 * mpage_da_map_and_submit to map a single contiguous memory region
2002 * and then write them.
2004 static int write_cache_pages_da(struct address_space
*mapping
,
2005 struct writeback_control
*wbc
,
2006 struct mpage_da_data
*mpd
,
2007 pgoff_t
*done_index
)
2009 struct buffer_head
*bh
, *head
;
2010 struct inode
*inode
= mapping
->host
;
2011 struct pagevec pvec
;
2012 unsigned int nr_pages
;
2015 long nr_to_write
= wbc
->nr_to_write
;
2016 int i
, tag
, ret
= 0;
2018 memset(mpd
, 0, sizeof(struct mpage_da_data
));
2021 pagevec_init(&pvec
, 0);
2022 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2023 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
2025 if (wbc
->sync_mode
== WB_SYNC_ALL
|| wbc
->tagged_writepages
)
2026 tag
= PAGECACHE_TAG_TOWRITE
;
2028 tag
= PAGECACHE_TAG_DIRTY
;
2030 *done_index
= index
;
2031 while (index
<= end
) {
2032 nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
, tag
,
2033 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1);
2037 for (i
= 0; i
< nr_pages
; i
++) {
2038 struct page
*page
= pvec
.pages
[i
];
2041 * At this point, the page may be truncated or
2042 * invalidated (changing page->mapping to NULL), or
2043 * even swizzled back from swapper_space to tmpfs file
2044 * mapping. However, page->index will not change
2045 * because we have a reference on the page.
2047 if (page
->index
> end
)
2050 *done_index
= page
->index
+ 1;
2053 * If we can't merge this page, and we have
2054 * accumulated an contiguous region, write it
2056 if ((mpd
->next_page
!= page
->index
) &&
2057 (mpd
->next_page
!= mpd
->first_page
)) {
2058 mpage_da_map_and_submit(mpd
);
2059 goto ret_extent_tail
;
2065 * If the page is no longer dirty, or its
2066 * mapping no longer corresponds to inode we
2067 * are writing (which means it has been
2068 * truncated or invalidated), or the page is
2069 * already under writeback and we are not
2070 * doing a data integrity writeback, skip the page
2072 if (!PageDirty(page
) ||
2073 (PageWriteback(page
) &&
2074 (wbc
->sync_mode
== WB_SYNC_NONE
)) ||
2075 unlikely(page
->mapping
!= mapping
)) {
2080 wait_on_page_writeback(page
);
2081 BUG_ON(PageWriteback(page
));
2083 if (mpd
->next_page
!= page
->index
)
2084 mpd
->first_page
= page
->index
;
2085 mpd
->next_page
= page
->index
+ 1;
2086 logical
= (sector_t
) page
->index
<<
2087 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2089 if (!page_has_buffers(page
)) {
2090 mpage_add_bh_to_extent(mpd
, logical
,
2092 (1 << BH_Dirty
) | (1 << BH_Uptodate
));
2094 goto ret_extent_tail
;
2097 * Page with regular buffer heads,
2098 * just add all dirty ones
2100 head
= page_buffers(page
);
2103 BUG_ON(buffer_locked(bh
));
2105 * We need to try to allocate
2106 * unmapped blocks in the same page.
2107 * Otherwise we won't make progress
2108 * with the page in ext4_writepage
2110 if (ext4_bh_delay_or_unwritten(NULL
, bh
)) {
2111 mpage_add_bh_to_extent(mpd
, logical
,
2115 goto ret_extent_tail
;
2116 } else if (buffer_dirty(bh
) && (buffer_mapped(bh
))) {
2118 * mapped dirty buffer. We need
2119 * to update the b_state
2120 * because we look at b_state
2121 * in mpage_da_map_blocks. We
2122 * don't update b_size because
2123 * if we find an unmapped
2124 * buffer_head later we need to
2125 * use the b_state flag of that
2128 if (mpd
->b_size
== 0)
2129 mpd
->b_state
= bh
->b_state
& BH_FLAGS
;
2132 } while ((bh
= bh
->b_this_page
) != head
);
2135 if (nr_to_write
> 0) {
2137 if (nr_to_write
== 0 &&
2138 wbc
->sync_mode
== WB_SYNC_NONE
)
2140 * We stop writing back only if we are
2141 * not doing integrity sync. In case of
2142 * integrity sync we have to keep going
2143 * because someone may be concurrently
2144 * dirtying pages, and we might have
2145 * synced a lot of newly appeared dirty
2146 * pages, but have not synced all of the
2152 pagevec_release(&pvec
);
2157 ret
= MPAGE_DA_EXTENT_TAIL
;
2159 pagevec_release(&pvec
);
2165 static int ext4_da_writepages(struct address_space
*mapping
,
2166 struct writeback_control
*wbc
)
2169 int range_whole
= 0;
2170 handle_t
*handle
= NULL
;
2171 struct mpage_da_data mpd
;
2172 struct inode
*inode
= mapping
->host
;
2173 int pages_written
= 0;
2174 unsigned int max_pages
;
2175 int range_cyclic
, cycled
= 1, io_done
= 0;
2176 int needed_blocks
, ret
= 0;
2177 long desired_nr_to_write
, nr_to_writebump
= 0;
2178 loff_t range_start
= wbc
->range_start
;
2179 struct ext4_sb_info
*sbi
= EXT4_SB(mapping
->host
->i_sb
);
2180 pgoff_t done_index
= 0;
2182 struct blk_plug plug
;
2184 trace_ext4_da_writepages(inode
, wbc
);
2187 * No pages to write? This is mainly a kludge to avoid starting
2188 * a transaction for special inodes like journal inode on last iput()
2189 * because that could violate lock ordering on umount
2191 if (!mapping
->nrpages
|| !mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
))
2195 * If the filesystem has aborted, it is read-only, so return
2196 * right away instead of dumping stack traces later on that
2197 * will obscure the real source of the problem. We test
2198 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2199 * the latter could be true if the filesystem is mounted
2200 * read-only, and in that case, ext4_da_writepages should
2201 * *never* be called, so if that ever happens, we would want
2204 if (unlikely(sbi
->s_mount_flags
& EXT4_MF_FS_ABORTED
))
2207 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2210 range_cyclic
= wbc
->range_cyclic
;
2211 if (wbc
->range_cyclic
) {
2212 index
= mapping
->writeback_index
;
2215 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2216 wbc
->range_end
= LLONG_MAX
;
2217 wbc
->range_cyclic
= 0;
2220 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2221 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
2225 * This works around two forms of stupidity. The first is in
2226 * the writeback code, which caps the maximum number of pages
2227 * written to be 1024 pages. This is wrong on multiple
2228 * levels; different architectues have a different page size,
2229 * which changes the maximum amount of data which gets
2230 * written. Secondly, 4 megabytes is way too small. XFS
2231 * forces this value to be 16 megabytes by multiplying
2232 * nr_to_write parameter by four, and then relies on its
2233 * allocator to allocate larger extents to make them
2234 * contiguous. Unfortunately this brings us to the second
2235 * stupidity, which is that ext4's mballoc code only allocates
2236 * at most 2048 blocks. So we force contiguous writes up to
2237 * the number of dirty blocks in the inode, or
2238 * sbi->max_writeback_mb_bump whichever is smaller.
2240 max_pages
= sbi
->s_max_writeback_mb_bump
<< (20 - PAGE_CACHE_SHIFT
);
2241 if (!range_cyclic
&& range_whole
) {
2242 if (wbc
->nr_to_write
== LONG_MAX
)
2243 desired_nr_to_write
= wbc
->nr_to_write
;
2245 desired_nr_to_write
= wbc
->nr_to_write
* 8;
2247 desired_nr_to_write
= ext4_num_dirty_pages(inode
, index
,
2249 if (desired_nr_to_write
> max_pages
)
2250 desired_nr_to_write
= max_pages
;
2252 if (wbc
->nr_to_write
< desired_nr_to_write
) {
2253 nr_to_writebump
= desired_nr_to_write
- wbc
->nr_to_write
;
2254 wbc
->nr_to_write
= desired_nr_to_write
;
2258 if (wbc
->sync_mode
== WB_SYNC_ALL
|| wbc
->tagged_writepages
)
2259 tag_pages_for_writeback(mapping
, index
, end
);
2261 blk_start_plug(&plug
);
2262 while (!ret
&& wbc
->nr_to_write
> 0) {
2265 * we insert one extent at a time. So we need
2266 * credit needed for single extent allocation.
2267 * journalled mode is currently not supported
2270 BUG_ON(ext4_should_journal_data(inode
));
2271 needed_blocks
= ext4_da_writepages_trans_blocks(inode
);
2273 /* start a new transaction*/
2274 handle
= ext4_journal_start(inode
, needed_blocks
);
2275 if (IS_ERR(handle
)) {
2276 ret
= PTR_ERR(handle
);
2277 ext4_msg(inode
->i_sb
, KERN_CRIT
, "%s: jbd2_start: "
2278 "%ld pages, ino %lu; err %d", __func__
,
2279 wbc
->nr_to_write
, inode
->i_ino
, ret
);
2280 blk_finish_plug(&plug
);
2281 goto out_writepages
;
2285 * Now call write_cache_pages_da() to find the next
2286 * contiguous region of logical blocks that need
2287 * blocks to be allocated by ext4 and submit them.
2289 ret
= write_cache_pages_da(mapping
, wbc
, &mpd
, &done_index
);
2291 * If we have a contiguous extent of pages and we
2292 * haven't done the I/O yet, map the blocks and submit
2295 if (!mpd
.io_done
&& mpd
.next_page
!= mpd
.first_page
) {
2296 mpage_da_map_and_submit(&mpd
);
2297 ret
= MPAGE_DA_EXTENT_TAIL
;
2299 trace_ext4_da_write_pages(inode
, &mpd
);
2300 wbc
->nr_to_write
-= mpd
.pages_written
;
2302 ext4_journal_stop(handle
);
2304 if ((mpd
.retval
== -ENOSPC
) && sbi
->s_journal
) {
2305 /* commit the transaction which would
2306 * free blocks released in the transaction
2309 jbd2_journal_force_commit_nested(sbi
->s_journal
);
2311 } else if (ret
== MPAGE_DA_EXTENT_TAIL
) {
2313 * Got one extent now try with rest of the pages.
2314 * If mpd.retval is set -EIO, journal is aborted.
2315 * So we don't need to write any more.
2317 pages_written
+= mpd
.pages_written
;
2320 } else if (wbc
->nr_to_write
)
2322 * There is no more writeout needed
2323 * or we requested for a noblocking writeout
2324 * and we found the device congested
2328 blk_finish_plug(&plug
);
2329 if (!io_done
&& !cycled
) {
2332 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2333 wbc
->range_end
= mapping
->writeback_index
- 1;
2338 wbc
->range_cyclic
= range_cyclic
;
2339 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
2341 * set the writeback_index so that range_cyclic
2342 * mode will write it back later
2344 mapping
->writeback_index
= done_index
;
2347 wbc
->nr_to_write
-= nr_to_writebump
;
2348 wbc
->range_start
= range_start
;
2349 trace_ext4_da_writepages_result(inode
, wbc
, ret
, pages_written
);
2353 #define FALL_BACK_TO_NONDELALLOC 1
2354 static int ext4_nonda_switch(struct super_block
*sb
)
2356 s64 free_blocks
, dirty_blocks
;
2357 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2360 * switch to non delalloc mode if we are running low
2361 * on free block. The free block accounting via percpu
2362 * counters can get slightly wrong with percpu_counter_batch getting
2363 * accumulated on each CPU without updating global counters
2364 * Delalloc need an accurate free block accounting. So switch
2365 * to non delalloc when we are near to error range.
2367 free_blocks
= EXT4_C2B(sbi
,
2368 percpu_counter_read_positive(&sbi
->s_freeclusters_counter
));
2369 dirty_blocks
= percpu_counter_read_positive(&sbi
->s_dirtyclusters_counter
);
2370 if (2 * free_blocks
< 3 * dirty_blocks
||
2371 free_blocks
< (dirty_blocks
+ EXT4_FREECLUSTERS_WATERMARK
)) {
2373 * free block count is less than 150% of dirty blocks
2374 * or free blocks is less than watermark
2379 * Even if we don't switch but are nearing capacity,
2380 * start pushing delalloc when 1/2 of free blocks are dirty.
2382 if (free_blocks
< 2 * dirty_blocks
)
2383 writeback_inodes_sb_if_idle(sb
, WB_REASON_FS_FREE_SPACE
);
2388 static int ext4_da_write_begin(struct file
*file
, struct address_space
*mapping
,
2389 loff_t pos
, unsigned len
, unsigned flags
,
2390 struct page
**pagep
, void **fsdata
)
2392 int ret
, retries
= 0;
2395 struct inode
*inode
= mapping
->host
;
2398 index
= pos
>> PAGE_CACHE_SHIFT
;
2400 if (ext4_nonda_switch(inode
->i_sb
)) {
2401 *fsdata
= (void *)FALL_BACK_TO_NONDELALLOC
;
2402 return ext4_write_begin(file
, mapping
, pos
,
2403 len
, flags
, pagep
, fsdata
);
2405 *fsdata
= (void *)0;
2406 trace_ext4_da_write_begin(inode
, pos
, len
, flags
);
2409 * With delayed allocation, we don't log the i_disksize update
2410 * if there is delayed block allocation. But we still need
2411 * to journalling the i_disksize update if writes to the end
2412 * of file which has an already mapped buffer.
2414 handle
= ext4_journal_start(inode
, 1);
2415 if (IS_ERR(handle
)) {
2416 ret
= PTR_ERR(handle
);
2419 /* We cannot recurse into the filesystem as the transaction is already
2421 flags
|= AOP_FLAG_NOFS
;
2423 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
2425 ext4_journal_stop(handle
);
2431 ret
= __block_write_begin(page
, pos
, len
, ext4_da_get_block_prep
);
2434 ext4_journal_stop(handle
);
2435 page_cache_release(page
);
2437 * block_write_begin may have instantiated a few blocks
2438 * outside i_size. Trim these off again. Don't need
2439 * i_size_read because we hold i_mutex.
2441 if (pos
+ len
> inode
->i_size
)
2442 ext4_truncate_failed_write(inode
);
2445 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
2452 * Check if we should update i_disksize
2453 * when write to the end of file but not require block allocation
2455 static int ext4_da_should_update_i_disksize(struct page
*page
,
2456 unsigned long offset
)
2458 struct buffer_head
*bh
;
2459 struct inode
*inode
= page
->mapping
->host
;
2463 bh
= page_buffers(page
);
2464 idx
= offset
>> inode
->i_blkbits
;
2466 for (i
= 0; i
< idx
; i
++)
2467 bh
= bh
->b_this_page
;
2469 if (!buffer_mapped(bh
) || (buffer_delay(bh
)) || buffer_unwritten(bh
))
2474 static int ext4_da_write_end(struct file
*file
,
2475 struct address_space
*mapping
,
2476 loff_t pos
, unsigned len
, unsigned copied
,
2477 struct page
*page
, void *fsdata
)
2479 struct inode
*inode
= mapping
->host
;
2481 handle_t
*handle
= ext4_journal_current_handle();
2483 unsigned long start
, end
;
2484 int write_mode
= (int)(unsigned long)fsdata
;
2486 if (write_mode
== FALL_BACK_TO_NONDELALLOC
) {
2487 switch (ext4_inode_journal_mode(inode
)) {
2488 case EXT4_INODE_ORDERED_DATA_MODE
:
2489 return ext4_ordered_write_end(file
, mapping
, pos
,
2490 len
, copied
, page
, fsdata
);
2491 case EXT4_INODE_WRITEBACK_DATA_MODE
:
2492 return ext4_writeback_write_end(file
, mapping
, pos
,
2493 len
, copied
, page
, fsdata
);
2499 trace_ext4_da_write_end(inode
, pos
, len
, copied
);
2500 start
= pos
& (PAGE_CACHE_SIZE
- 1);
2501 end
= start
+ copied
- 1;
2504 * generic_write_end() will run mark_inode_dirty() if i_size
2505 * changes. So let's piggyback the i_disksize mark_inode_dirty
2509 new_i_size
= pos
+ copied
;
2510 if (copied
&& new_i_size
> EXT4_I(inode
)->i_disksize
) {
2511 if (ext4_da_should_update_i_disksize(page
, end
)) {
2512 down_write(&EXT4_I(inode
)->i_data_sem
);
2513 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
2515 * Updating i_disksize when extending file
2516 * without needing block allocation
2518 if (ext4_should_order_data(inode
))
2519 ret
= ext4_jbd2_file_inode(handle
,
2522 EXT4_I(inode
)->i_disksize
= new_i_size
;
2524 up_write(&EXT4_I(inode
)->i_data_sem
);
2525 /* We need to mark inode dirty even if
2526 * new_i_size is less that inode->i_size
2527 * bu greater than i_disksize.(hint delalloc)
2529 ext4_mark_inode_dirty(handle
, inode
);
2532 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
2537 ret2
= ext4_journal_stop(handle
);
2541 return ret
? ret
: copied
;
2544 static void ext4_da_invalidatepage(struct page
*page
, unsigned long offset
)
2547 * Drop reserved blocks
2549 BUG_ON(!PageLocked(page
));
2550 if (!page_has_buffers(page
))
2553 ext4_da_page_release_reservation(page
, offset
);
2556 ext4_invalidatepage(page
, offset
);
2562 * Force all delayed allocation blocks to be allocated for a given inode.
2564 int ext4_alloc_da_blocks(struct inode
*inode
)
2566 trace_ext4_alloc_da_blocks(inode
);
2568 if (!EXT4_I(inode
)->i_reserved_data_blocks
&&
2569 !EXT4_I(inode
)->i_reserved_meta_blocks
)
2573 * We do something simple for now. The filemap_flush() will
2574 * also start triggering a write of the data blocks, which is
2575 * not strictly speaking necessary (and for users of
2576 * laptop_mode, not even desirable). However, to do otherwise
2577 * would require replicating code paths in:
2579 * ext4_da_writepages() ->
2580 * write_cache_pages() ---> (via passed in callback function)
2581 * __mpage_da_writepage() -->
2582 * mpage_add_bh_to_extent()
2583 * mpage_da_map_blocks()
2585 * The problem is that write_cache_pages(), located in
2586 * mm/page-writeback.c, marks pages clean in preparation for
2587 * doing I/O, which is not desirable if we're not planning on
2590 * We could call write_cache_pages(), and then redirty all of
2591 * the pages by calling redirty_page_for_writepage() but that
2592 * would be ugly in the extreme. So instead we would need to
2593 * replicate parts of the code in the above functions,
2594 * simplifying them because we wouldn't actually intend to
2595 * write out the pages, but rather only collect contiguous
2596 * logical block extents, call the multi-block allocator, and
2597 * then update the buffer heads with the block allocations.
2599 * For now, though, we'll cheat by calling filemap_flush(),
2600 * which will map the blocks, and start the I/O, but not
2601 * actually wait for the I/O to complete.
2603 return filemap_flush(inode
->i_mapping
);
2607 * bmap() is special. It gets used by applications such as lilo and by
2608 * the swapper to find the on-disk block of a specific piece of data.
2610 * Naturally, this is dangerous if the block concerned is still in the
2611 * journal. If somebody makes a swapfile on an ext4 data-journaling
2612 * filesystem and enables swap, then they may get a nasty shock when the
2613 * data getting swapped to that swapfile suddenly gets overwritten by
2614 * the original zero's written out previously to the journal and
2615 * awaiting writeback in the kernel's buffer cache.
2617 * So, if we see any bmap calls here on a modified, data-journaled file,
2618 * take extra steps to flush any blocks which might be in the cache.
2620 static sector_t
ext4_bmap(struct address_space
*mapping
, sector_t block
)
2622 struct inode
*inode
= mapping
->host
;
2626 if (mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
) &&
2627 test_opt(inode
->i_sb
, DELALLOC
)) {
2629 * With delalloc we want to sync the file
2630 * so that we can make sure we allocate
2633 filemap_write_and_wait(mapping
);
2636 if (EXT4_JOURNAL(inode
) &&
2637 ext4_test_inode_state(inode
, EXT4_STATE_JDATA
)) {
2639 * This is a REALLY heavyweight approach, but the use of
2640 * bmap on dirty files is expected to be extremely rare:
2641 * only if we run lilo or swapon on a freshly made file
2642 * do we expect this to happen.
2644 * (bmap requires CAP_SYS_RAWIO so this does not
2645 * represent an unprivileged user DOS attack --- we'd be
2646 * in trouble if mortal users could trigger this path at
2649 * NB. EXT4_STATE_JDATA is not set on files other than
2650 * regular files. If somebody wants to bmap a directory
2651 * or symlink and gets confused because the buffer
2652 * hasn't yet been flushed to disk, they deserve
2653 * everything they get.
2656 ext4_clear_inode_state(inode
, EXT4_STATE_JDATA
);
2657 journal
= EXT4_JOURNAL(inode
);
2658 jbd2_journal_lock_updates(journal
);
2659 err
= jbd2_journal_flush(journal
);
2660 jbd2_journal_unlock_updates(journal
);
2666 return generic_block_bmap(mapping
, block
, ext4_get_block
);
2669 static int ext4_readpage(struct file
*file
, struct page
*page
)
2671 trace_ext4_readpage(page
);
2672 return mpage_readpage(page
, ext4_get_block
);
2676 ext4_readpages(struct file
*file
, struct address_space
*mapping
,
2677 struct list_head
*pages
, unsigned nr_pages
)
2679 return mpage_readpages(mapping
, pages
, nr_pages
, ext4_get_block
);
2682 static void ext4_invalidatepage_free_endio(struct page
*page
, unsigned long offset
)
2684 struct buffer_head
*head
, *bh
;
2685 unsigned int curr_off
= 0;
2687 if (!page_has_buffers(page
))
2689 head
= bh
= page_buffers(page
);
2691 if (offset
<= curr_off
&& test_clear_buffer_uninit(bh
)
2693 ext4_free_io_end(bh
->b_private
);
2694 bh
->b_private
= NULL
;
2695 bh
->b_end_io
= NULL
;
2697 curr_off
= curr_off
+ bh
->b_size
;
2698 bh
= bh
->b_this_page
;
2699 } while (bh
!= head
);
2702 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
)
2704 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
2706 trace_ext4_invalidatepage(page
, offset
);
2709 * free any io_end structure allocated for buffers to be discarded
2711 if (ext4_should_dioread_nolock(page
->mapping
->host
))
2712 ext4_invalidatepage_free_endio(page
, offset
);
2714 * If it's a full truncate we just forget about the pending dirtying
2717 ClearPageChecked(page
);
2720 jbd2_journal_invalidatepage(journal
, page
, offset
);
2722 block_invalidatepage(page
, offset
);
2725 static int ext4_releasepage(struct page
*page
, gfp_t wait
)
2727 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
2729 trace_ext4_releasepage(page
);
2731 WARN_ON(PageChecked(page
));
2732 if (!page_has_buffers(page
))
2735 return jbd2_journal_try_to_free_buffers(journal
, page
, wait
);
2737 return try_to_free_buffers(page
);
2741 * ext4_get_block used when preparing for a DIO write or buffer write.
2742 * We allocate an uinitialized extent if blocks haven't been allocated.
2743 * The extent will be converted to initialized after the IO is complete.
2745 static int ext4_get_block_write(struct inode
*inode
, sector_t iblock
,
2746 struct buffer_head
*bh_result
, int create
)
2748 ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n",
2749 inode
->i_ino
, create
);
2750 return _ext4_get_block(inode
, iblock
, bh_result
,
2751 EXT4_GET_BLOCKS_IO_CREATE_EXT
);
2754 static void ext4_end_io_dio(struct kiocb
*iocb
, loff_t offset
,
2755 ssize_t size
, void *private, int ret
,
2758 struct inode
*inode
= iocb
->ki_filp
->f_path
.dentry
->d_inode
;
2759 ext4_io_end_t
*io_end
= iocb
->private;
2760 struct workqueue_struct
*wq
;
2761 unsigned long flags
;
2762 struct ext4_inode_info
*ei
;
2764 /* if not async direct IO or dio with 0 bytes write, just return */
2765 if (!io_end
|| !size
)
2768 ext_debug("ext4_end_io_dio(): io_end 0x%p "
2769 "for inode %lu, iocb 0x%p, offset %llu, size %zd\n",
2770 iocb
->private, io_end
->inode
->i_ino
, iocb
, offset
,
2773 iocb
->private = NULL
;
2775 /* if not aio dio with unwritten extents, just free io and return */
2776 if (!(io_end
->flag
& EXT4_IO_END_UNWRITTEN
)) {
2777 ext4_free_io_end(io_end
);
2780 aio_complete(iocb
, ret
, 0);
2781 inode_dio_done(inode
);
2785 io_end
->offset
= offset
;
2786 io_end
->size
= size
;
2788 io_end
->iocb
= iocb
;
2789 io_end
->result
= ret
;
2791 wq
= EXT4_SB(io_end
->inode
->i_sb
)->dio_unwritten_wq
;
2793 /* Add the io_end to per-inode completed aio dio list*/
2794 ei
= EXT4_I(io_end
->inode
);
2795 spin_lock_irqsave(&ei
->i_completed_io_lock
, flags
);
2796 list_add_tail(&io_end
->list
, &ei
->i_completed_io_list
);
2797 spin_unlock_irqrestore(&ei
->i_completed_io_lock
, flags
);
2799 /* queue the work to convert unwritten extents to written */
2800 queue_work(wq
, &io_end
->work
);
2803 static void ext4_end_io_buffer_write(struct buffer_head
*bh
, int uptodate
)
2805 ext4_io_end_t
*io_end
= bh
->b_private
;
2806 struct workqueue_struct
*wq
;
2807 struct inode
*inode
;
2808 unsigned long flags
;
2810 if (!test_clear_buffer_uninit(bh
) || !io_end
)
2813 if (!(io_end
->inode
->i_sb
->s_flags
& MS_ACTIVE
)) {
2814 ext4_msg(io_end
->inode
->i_sb
, KERN_INFO
,
2815 "sb umounted, discard end_io request for inode %lu",
2816 io_end
->inode
->i_ino
);
2817 ext4_free_io_end(io_end
);
2822 * It may be over-defensive here to check EXT4_IO_END_UNWRITTEN now,
2823 * but being more careful is always safe for the future change.
2825 inode
= io_end
->inode
;
2826 ext4_set_io_unwritten_flag(inode
, io_end
);
2828 /* Add the io_end to per-inode completed io list*/
2829 spin_lock_irqsave(&EXT4_I(inode
)->i_completed_io_lock
, flags
);
2830 list_add_tail(&io_end
->list
, &EXT4_I(inode
)->i_completed_io_list
);
2831 spin_unlock_irqrestore(&EXT4_I(inode
)->i_completed_io_lock
, flags
);
2833 wq
= EXT4_SB(inode
->i_sb
)->dio_unwritten_wq
;
2834 /* queue the work to convert unwritten extents to written */
2835 queue_work(wq
, &io_end
->work
);
2837 bh
->b_private
= NULL
;
2838 bh
->b_end_io
= NULL
;
2839 clear_buffer_uninit(bh
);
2840 end_buffer_async_write(bh
, uptodate
);
2843 static int ext4_set_bh_endio(struct buffer_head
*bh
, struct inode
*inode
)
2845 ext4_io_end_t
*io_end
;
2846 struct page
*page
= bh
->b_page
;
2847 loff_t offset
= (sector_t
)page
->index
<< PAGE_CACHE_SHIFT
;
2848 size_t size
= bh
->b_size
;
2851 io_end
= ext4_init_io_end(inode
, GFP_ATOMIC
);
2853 pr_warn_ratelimited("%s: allocation fail\n", __func__
);
2857 io_end
->offset
= offset
;
2858 io_end
->size
= size
;
2860 * We need to hold a reference to the page to make sure it
2861 * doesn't get evicted before ext4_end_io_work() has a chance
2862 * to convert the extent from written to unwritten.
2864 io_end
->page
= page
;
2865 get_page(io_end
->page
);
2867 bh
->b_private
= io_end
;
2868 bh
->b_end_io
= ext4_end_io_buffer_write
;
2873 * For ext4 extent files, ext4 will do direct-io write to holes,
2874 * preallocated extents, and those write extend the file, no need to
2875 * fall back to buffered IO.
2877 * For holes, we fallocate those blocks, mark them as uninitialized
2878 * If those blocks were preallocated, we mark sure they are splited, but
2879 * still keep the range to write as uninitialized.
2881 * The unwrritten extents will be converted to written when DIO is completed.
2882 * For async direct IO, since the IO may still pending when return, we
2883 * set up an end_io call back function, which will do the conversion
2884 * when async direct IO completed.
2886 * If the O_DIRECT write will extend the file then add this inode to the
2887 * orphan list. So recovery will truncate it back to the original size
2888 * if the machine crashes during the write.
2891 static ssize_t
ext4_ext_direct_IO(int rw
, struct kiocb
*iocb
,
2892 const struct iovec
*iov
, loff_t offset
,
2893 unsigned long nr_segs
)
2895 struct file
*file
= iocb
->ki_filp
;
2896 struct inode
*inode
= file
->f_mapping
->host
;
2898 size_t count
= iov_length(iov
, nr_segs
);
2900 loff_t final_size
= offset
+ count
;
2901 if (rw
== WRITE
&& final_size
<= inode
->i_size
) {
2903 * We could direct write to holes and fallocate.
2905 * Allocated blocks to fill the hole are marked as uninitialized
2906 * to prevent parallel buffered read to expose the stale data
2907 * before DIO complete the data IO.
2909 * As to previously fallocated extents, ext4 get_block
2910 * will just simply mark the buffer mapped but still
2911 * keep the extents uninitialized.
2913 * for non AIO case, we will convert those unwritten extents
2914 * to written after return back from blockdev_direct_IO.
2916 * for async DIO, the conversion needs to be defered when
2917 * the IO is completed. The ext4 end_io callback function
2918 * will be called to take care of the conversion work.
2919 * Here for async case, we allocate an io_end structure to
2922 iocb
->private = NULL
;
2923 EXT4_I(inode
)->cur_aio_dio
= NULL
;
2924 if (!is_sync_kiocb(iocb
)) {
2925 ext4_io_end_t
*io_end
=
2926 ext4_init_io_end(inode
, GFP_NOFS
);
2929 io_end
->flag
|= EXT4_IO_END_DIRECT
;
2930 iocb
->private = io_end
;
2932 * we save the io structure for current async
2933 * direct IO, so that later ext4_map_blocks()
2934 * could flag the io structure whether there
2935 * is a unwritten extents needs to be converted
2936 * when IO is completed.
2938 EXT4_I(inode
)->cur_aio_dio
= iocb
->private;
2941 ret
= __blockdev_direct_IO(rw
, iocb
, inode
,
2942 inode
->i_sb
->s_bdev
, iov
,
2944 ext4_get_block_write
,
2949 EXT4_I(inode
)->cur_aio_dio
= NULL
;
2951 * The io_end structure takes a reference to the inode,
2952 * that structure needs to be destroyed and the
2953 * reference to the inode need to be dropped, when IO is
2954 * complete, even with 0 byte write, or failed.
2956 * In the successful AIO DIO case, the io_end structure will be
2957 * desctroyed and the reference to the inode will be dropped
2958 * after the end_io call back function is called.
2960 * In the case there is 0 byte write, or error case, since
2961 * VFS direct IO won't invoke the end_io call back function,
2962 * we need to free the end_io structure here.
2964 if (ret
!= -EIOCBQUEUED
&& ret
<= 0 && iocb
->private) {
2965 ext4_free_io_end(iocb
->private);
2966 iocb
->private = NULL
;
2967 } else if (ret
> 0 && ext4_test_inode_state(inode
,
2968 EXT4_STATE_DIO_UNWRITTEN
)) {
2971 * for non AIO case, since the IO is already
2972 * completed, we could do the conversion right here
2974 err
= ext4_convert_unwritten_extents(inode
,
2978 ext4_clear_inode_state(inode
, EXT4_STATE_DIO_UNWRITTEN
);
2983 /* for write the the end of file case, we fall back to old way */
2984 return ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
2987 static ssize_t
ext4_direct_IO(int rw
, struct kiocb
*iocb
,
2988 const struct iovec
*iov
, loff_t offset
,
2989 unsigned long nr_segs
)
2991 struct file
*file
= iocb
->ki_filp
;
2992 struct inode
*inode
= file
->f_mapping
->host
;
2996 * If we are doing data journalling we don't support O_DIRECT
2998 if (ext4_should_journal_data(inode
))
3001 trace_ext4_direct_IO_enter(inode
, offset
, iov_length(iov
, nr_segs
), rw
);
3002 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
))
3003 ret
= ext4_ext_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3005 ret
= ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3006 trace_ext4_direct_IO_exit(inode
, offset
,
3007 iov_length(iov
, nr_segs
), rw
, ret
);
3012 * Pages can be marked dirty completely asynchronously from ext4's journalling
3013 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3014 * much here because ->set_page_dirty is called under VFS locks. The page is
3015 * not necessarily locked.
3017 * We cannot just dirty the page and leave attached buffers clean, because the
3018 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3019 * or jbddirty because all the journalling code will explode.
3021 * So what we do is to mark the page "pending dirty" and next time writepage
3022 * is called, propagate that into the buffers appropriately.
3024 static int ext4_journalled_set_page_dirty(struct page
*page
)
3026 SetPageChecked(page
);
3027 return __set_page_dirty_nobuffers(page
);
3030 static const struct address_space_operations ext4_ordered_aops
= {
3031 .readpage
= ext4_readpage
,
3032 .readpages
= ext4_readpages
,
3033 .writepage
= ext4_writepage
,
3034 .write_begin
= ext4_write_begin
,
3035 .write_end
= ext4_ordered_write_end
,
3037 .invalidatepage
= ext4_invalidatepage
,
3038 .releasepage
= ext4_releasepage
,
3039 .direct_IO
= ext4_direct_IO
,
3040 .migratepage
= buffer_migrate_page
,
3041 .is_partially_uptodate
= block_is_partially_uptodate
,
3042 .error_remove_page
= generic_error_remove_page
,
3045 static const struct address_space_operations ext4_writeback_aops
= {
3046 .readpage
= ext4_readpage
,
3047 .readpages
= ext4_readpages
,
3048 .writepage
= ext4_writepage
,
3049 .write_begin
= ext4_write_begin
,
3050 .write_end
= ext4_writeback_write_end
,
3052 .invalidatepage
= ext4_invalidatepage
,
3053 .releasepage
= ext4_releasepage
,
3054 .direct_IO
= ext4_direct_IO
,
3055 .migratepage
= buffer_migrate_page
,
3056 .is_partially_uptodate
= block_is_partially_uptodate
,
3057 .error_remove_page
= generic_error_remove_page
,
3060 static const struct address_space_operations ext4_journalled_aops
= {
3061 .readpage
= ext4_readpage
,
3062 .readpages
= ext4_readpages
,
3063 .writepage
= ext4_writepage
,
3064 .write_begin
= ext4_write_begin
,
3065 .write_end
= ext4_journalled_write_end
,
3066 .set_page_dirty
= ext4_journalled_set_page_dirty
,
3068 .invalidatepage
= ext4_invalidatepage
,
3069 .releasepage
= ext4_releasepage
,
3070 .direct_IO
= ext4_direct_IO
,
3071 .is_partially_uptodate
= block_is_partially_uptodate
,
3072 .error_remove_page
= generic_error_remove_page
,
3075 static const struct address_space_operations ext4_da_aops
= {
3076 .readpage
= ext4_readpage
,
3077 .readpages
= ext4_readpages
,
3078 .writepage
= ext4_writepage
,
3079 .writepages
= ext4_da_writepages
,
3080 .write_begin
= ext4_da_write_begin
,
3081 .write_end
= ext4_da_write_end
,
3083 .invalidatepage
= ext4_da_invalidatepage
,
3084 .releasepage
= ext4_releasepage
,
3085 .direct_IO
= ext4_direct_IO
,
3086 .migratepage
= buffer_migrate_page
,
3087 .is_partially_uptodate
= block_is_partially_uptodate
,
3088 .error_remove_page
= generic_error_remove_page
,
3091 void ext4_set_aops(struct inode
*inode
)
3093 switch (ext4_inode_journal_mode(inode
)) {
3094 case EXT4_INODE_ORDERED_DATA_MODE
:
3095 if (test_opt(inode
->i_sb
, DELALLOC
))
3096 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3098 inode
->i_mapping
->a_ops
= &ext4_ordered_aops
;
3100 case EXT4_INODE_WRITEBACK_DATA_MODE
:
3101 if (test_opt(inode
->i_sb
, DELALLOC
))
3102 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3104 inode
->i_mapping
->a_ops
= &ext4_writeback_aops
;
3106 case EXT4_INODE_JOURNAL_DATA_MODE
:
3107 inode
->i_mapping
->a_ops
= &ext4_journalled_aops
;
3116 * ext4_discard_partial_page_buffers()
3117 * Wrapper function for ext4_discard_partial_page_buffers_no_lock.
3118 * This function finds and locks the page containing the offset
3119 * "from" and passes it to ext4_discard_partial_page_buffers_no_lock.
3120 * Calling functions that already have the page locked should call
3121 * ext4_discard_partial_page_buffers_no_lock directly.
3123 int ext4_discard_partial_page_buffers(handle_t
*handle
,
3124 struct address_space
*mapping
, loff_t from
,
3125 loff_t length
, int flags
)
3127 struct inode
*inode
= mapping
->host
;
3131 page
= find_or_create_page(mapping
, from
>> PAGE_CACHE_SHIFT
,
3132 mapping_gfp_mask(mapping
) & ~__GFP_FS
);
3136 err
= ext4_discard_partial_page_buffers_no_lock(handle
, inode
, page
,
3137 from
, length
, flags
);
3140 page_cache_release(page
);
3145 * ext4_discard_partial_page_buffers_no_lock()
3146 * Zeros a page range of length 'length' starting from offset 'from'.
3147 * Buffer heads that correspond to the block aligned regions of the
3148 * zeroed range will be unmapped. Unblock aligned regions
3149 * will have the corresponding buffer head mapped if needed so that
3150 * that region of the page can be updated with the partial zero out.
3152 * This function assumes that the page has already been locked. The
3153 * The range to be discarded must be contained with in the given page.
3154 * If the specified range exceeds the end of the page it will be shortened
3155 * to the end of the page that corresponds to 'from'. This function is
3156 * appropriate for updating a page and it buffer heads to be unmapped and
3157 * zeroed for blocks that have been either released, or are going to be
3160 * handle: The journal handle
3161 * inode: The files inode
3162 * page: A locked page that contains the offset "from"
3163 * from: The starting byte offset (from the begining of the file)
3164 * to begin discarding
3165 * len: The length of bytes to discard
3166 * flags: Optional flags that may be used:
3168 * EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED
3169 * Only zero the regions of the page whose buffer heads
3170 * have already been unmapped. This flag is appropriate
3171 * for updateing the contents of a page whose blocks may
3172 * have already been released, and we only want to zero
3173 * out the regions that correspond to those released blocks.
3175 * Returns zero on sucess or negative on failure.
3177 static int ext4_discard_partial_page_buffers_no_lock(handle_t
*handle
,
3178 struct inode
*inode
, struct page
*page
, loff_t from
,
3179 loff_t length
, int flags
)
3181 ext4_fsblk_t index
= from
>> PAGE_CACHE_SHIFT
;
3182 unsigned int offset
= from
& (PAGE_CACHE_SIZE
-1);
3183 unsigned int blocksize
, max
, pos
;
3185 struct buffer_head
*bh
;
3188 blocksize
= inode
->i_sb
->s_blocksize
;
3189 max
= PAGE_CACHE_SIZE
- offset
;
3191 if (index
!= page
->index
)
3195 * correct length if it does not fall between
3196 * 'from' and the end of the page
3198 if (length
> max
|| length
< 0)
3201 iblock
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
3203 if (!page_has_buffers(page
))
3204 create_empty_buffers(page
, blocksize
, 0);
3206 /* Find the buffer that contains "offset" */
3207 bh
= page_buffers(page
);
3209 while (offset
>= pos
) {
3210 bh
= bh
->b_this_page
;
3216 while (pos
< offset
+ length
) {
3217 unsigned int end_of_block
, range_to_discard
;
3221 /* The length of space left to zero and unmap */
3222 range_to_discard
= offset
+ length
- pos
;
3224 /* The length of space until the end of the block */
3225 end_of_block
= blocksize
- (pos
& (blocksize
-1));
3228 * Do not unmap or zero past end of block
3229 * for this buffer head
3231 if (range_to_discard
> end_of_block
)
3232 range_to_discard
= end_of_block
;
3236 * Skip this buffer head if we are only zeroing unampped
3237 * regions of the page
3239 if (flags
& EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED
&&
3243 /* If the range is block aligned, unmap */
3244 if (range_to_discard
== blocksize
) {
3245 clear_buffer_dirty(bh
);
3247 clear_buffer_mapped(bh
);
3248 clear_buffer_req(bh
);
3249 clear_buffer_new(bh
);
3250 clear_buffer_delay(bh
);
3251 clear_buffer_unwritten(bh
);
3252 clear_buffer_uptodate(bh
);
3253 zero_user(page
, pos
, range_to_discard
);
3254 BUFFER_TRACE(bh
, "Buffer discarded");
3259 * If this block is not completely contained in the range
3260 * to be discarded, then it is not going to be released. Because
3261 * we need to keep this block, we need to make sure this part
3262 * of the page is uptodate before we modify it by writeing
3263 * partial zeros on it.
3265 if (!buffer_mapped(bh
)) {
3267 * Buffer head must be mapped before we can read
3270 BUFFER_TRACE(bh
, "unmapped");
3271 ext4_get_block(inode
, iblock
, bh
, 0);
3272 /* unmapped? It's a hole - nothing to do */
3273 if (!buffer_mapped(bh
)) {
3274 BUFFER_TRACE(bh
, "still unmapped");
3279 /* Ok, it's mapped. Make sure it's up-to-date */
3280 if (PageUptodate(page
))
3281 set_buffer_uptodate(bh
);
3283 if (!buffer_uptodate(bh
)) {
3285 ll_rw_block(READ
, 1, &bh
);
3287 /* Uhhuh. Read error. Complain and punt.*/
3288 if (!buffer_uptodate(bh
))
3292 if (ext4_should_journal_data(inode
)) {
3293 BUFFER_TRACE(bh
, "get write access");
3294 err
= ext4_journal_get_write_access(handle
, bh
);
3299 zero_user(page
, pos
, range_to_discard
);
3302 if (ext4_should_journal_data(inode
)) {
3303 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
3305 mark_buffer_dirty(bh
);
3307 BUFFER_TRACE(bh
, "Partial buffer zeroed");
3309 bh
= bh
->b_this_page
;
3311 pos
+= range_to_discard
;
3317 int ext4_can_truncate(struct inode
*inode
)
3319 if (S_ISREG(inode
->i_mode
))
3321 if (S_ISDIR(inode
->i_mode
))
3323 if (S_ISLNK(inode
->i_mode
))
3324 return !ext4_inode_is_fast_symlink(inode
);
3329 * ext4_punch_hole: punches a hole in a file by releaseing the blocks
3330 * associated with the given offset and length
3332 * @inode: File inode
3333 * @offset: The offset where the hole will begin
3334 * @len: The length of the hole
3336 * Returns: 0 on sucess or negative on failure
3339 int ext4_punch_hole(struct file
*file
, loff_t offset
, loff_t length
)
3341 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
3342 if (!S_ISREG(inode
->i_mode
))
3345 if (!ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) {
3346 /* TODO: Add support for non extent hole punching */
3350 if (EXT4_SB(inode
->i_sb
)->s_cluster_ratio
> 1) {
3351 /* TODO: Add support for bigalloc file systems */
3355 return ext4_ext_punch_hole(file
, offset
, length
);
3361 * We block out ext4_get_block() block instantiations across the entire
3362 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
3363 * simultaneously on behalf of the same inode.
3365 * As we work through the truncate and commit bits of it to the journal there
3366 * is one core, guiding principle: the file's tree must always be consistent on
3367 * disk. We must be able to restart the truncate after a crash.
3369 * The file's tree may be transiently inconsistent in memory (although it
3370 * probably isn't), but whenever we close off and commit a journal transaction,
3371 * the contents of (the filesystem + the journal) must be consistent and
3372 * restartable. It's pretty simple, really: bottom up, right to left (although
3373 * left-to-right works OK too).
3375 * Note that at recovery time, journal replay occurs *before* the restart of
3376 * truncate against the orphan inode list.
3378 * The committed inode has the new, desired i_size (which is the same as
3379 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
3380 * that this inode's truncate did not complete and it will again call
3381 * ext4_truncate() to have another go. So there will be instantiated blocks
3382 * to the right of the truncation point in a crashed ext4 filesystem. But
3383 * that's fine - as long as they are linked from the inode, the post-crash
3384 * ext4_truncate() run will find them and release them.
3386 void ext4_truncate(struct inode
*inode
)
3388 trace_ext4_truncate_enter(inode
);
3390 if (!ext4_can_truncate(inode
))
3393 ext4_clear_inode_flag(inode
, EXT4_INODE_EOFBLOCKS
);
3395 if (inode
->i_size
== 0 && !test_opt(inode
->i_sb
, NO_AUTO_DA_ALLOC
))
3396 ext4_set_inode_state(inode
, EXT4_STATE_DA_ALLOC_CLOSE
);
3398 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
))
3399 ext4_ext_truncate(inode
);
3401 ext4_ind_truncate(inode
);
3403 trace_ext4_truncate_exit(inode
);
3407 * ext4_get_inode_loc returns with an extra refcount against the inode's
3408 * underlying buffer_head on success. If 'in_mem' is true, we have all
3409 * data in memory that is needed to recreate the on-disk version of this
3412 static int __ext4_get_inode_loc(struct inode
*inode
,
3413 struct ext4_iloc
*iloc
, int in_mem
)
3415 struct ext4_group_desc
*gdp
;
3416 struct buffer_head
*bh
;
3417 struct super_block
*sb
= inode
->i_sb
;
3419 int inodes_per_block
, inode_offset
;
3422 if (!ext4_valid_inum(sb
, inode
->i_ino
))
3425 iloc
->block_group
= (inode
->i_ino
- 1) / EXT4_INODES_PER_GROUP(sb
);
3426 gdp
= ext4_get_group_desc(sb
, iloc
->block_group
, NULL
);
3431 * Figure out the offset within the block group inode table
3433 inodes_per_block
= EXT4_SB(sb
)->s_inodes_per_block
;
3434 inode_offset
= ((inode
->i_ino
- 1) %
3435 EXT4_INODES_PER_GROUP(sb
));
3436 block
= ext4_inode_table(sb
, gdp
) + (inode_offset
/ inodes_per_block
);
3437 iloc
->offset
= (inode_offset
% inodes_per_block
) * EXT4_INODE_SIZE(sb
);
3439 bh
= sb_getblk(sb
, block
);
3441 EXT4_ERROR_INODE_BLOCK(inode
, block
,
3442 "unable to read itable block");
3445 if (!buffer_uptodate(bh
)) {
3449 * If the buffer has the write error flag, we have failed
3450 * to write out another inode in the same block. In this
3451 * case, we don't have to read the block because we may
3452 * read the old inode data successfully.
3454 if (buffer_write_io_error(bh
) && !buffer_uptodate(bh
))
3455 set_buffer_uptodate(bh
);
3457 if (buffer_uptodate(bh
)) {
3458 /* someone brought it uptodate while we waited */
3464 * If we have all information of the inode in memory and this
3465 * is the only valid inode in the block, we need not read the
3469 struct buffer_head
*bitmap_bh
;
3472 start
= inode_offset
& ~(inodes_per_block
- 1);
3474 /* Is the inode bitmap in cache? */
3475 bitmap_bh
= sb_getblk(sb
, ext4_inode_bitmap(sb
, gdp
));
3480 * If the inode bitmap isn't in cache then the
3481 * optimisation may end up performing two reads instead
3482 * of one, so skip it.
3484 if (!buffer_uptodate(bitmap_bh
)) {
3488 for (i
= start
; i
< start
+ inodes_per_block
; i
++) {
3489 if (i
== inode_offset
)
3491 if (ext4_test_bit(i
, bitmap_bh
->b_data
))
3495 if (i
== start
+ inodes_per_block
) {
3496 /* all other inodes are free, so skip I/O */
3497 memset(bh
->b_data
, 0, bh
->b_size
);
3498 set_buffer_uptodate(bh
);
3506 * If we need to do any I/O, try to pre-readahead extra
3507 * blocks from the inode table.
3509 if (EXT4_SB(sb
)->s_inode_readahead_blks
) {
3510 ext4_fsblk_t b
, end
, table
;
3513 table
= ext4_inode_table(sb
, gdp
);
3514 /* s_inode_readahead_blks is always a power of 2 */
3515 b
= block
& ~(EXT4_SB(sb
)->s_inode_readahead_blks
-1);
3518 end
= b
+ EXT4_SB(sb
)->s_inode_readahead_blks
;
3519 num
= EXT4_INODES_PER_GROUP(sb
);
3520 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
3521 EXT4_FEATURE_RO_COMPAT_GDT_CSUM
))
3522 num
-= ext4_itable_unused_count(sb
, gdp
);
3523 table
+= num
/ inodes_per_block
;
3527 sb_breadahead(sb
, b
++);
3531 * There are other valid inodes in the buffer, this inode
3532 * has in-inode xattrs, or we don't have this inode in memory.
3533 * Read the block from disk.
3535 trace_ext4_load_inode(inode
);
3537 bh
->b_end_io
= end_buffer_read_sync
;
3538 submit_bh(READ
| REQ_META
| REQ_PRIO
, bh
);
3540 if (!buffer_uptodate(bh
)) {
3541 EXT4_ERROR_INODE_BLOCK(inode
, block
,
3542 "unable to read itable block");
3552 int ext4_get_inode_loc(struct inode
*inode
, struct ext4_iloc
*iloc
)
3554 /* We have all inode data except xattrs in memory here. */
3555 return __ext4_get_inode_loc(inode
, iloc
,
3556 !ext4_test_inode_state(inode
, EXT4_STATE_XATTR
));
3559 void ext4_set_inode_flags(struct inode
*inode
)
3561 unsigned int flags
= EXT4_I(inode
)->i_flags
;
3563 inode
->i_flags
&= ~(S_SYNC
|S_APPEND
|S_IMMUTABLE
|S_NOATIME
|S_DIRSYNC
);
3564 if (flags
& EXT4_SYNC_FL
)
3565 inode
->i_flags
|= S_SYNC
;
3566 if (flags
& EXT4_APPEND_FL
)
3567 inode
->i_flags
|= S_APPEND
;
3568 if (flags
& EXT4_IMMUTABLE_FL
)
3569 inode
->i_flags
|= S_IMMUTABLE
;
3570 if (flags
& EXT4_NOATIME_FL
)
3571 inode
->i_flags
|= S_NOATIME
;
3572 if (flags
& EXT4_DIRSYNC_FL
)
3573 inode
->i_flags
|= S_DIRSYNC
;
3576 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
3577 void ext4_get_inode_flags(struct ext4_inode_info
*ei
)
3579 unsigned int vfs_fl
;
3580 unsigned long old_fl
, new_fl
;
3583 vfs_fl
= ei
->vfs_inode
.i_flags
;
3584 old_fl
= ei
->i_flags
;
3585 new_fl
= old_fl
& ~(EXT4_SYNC_FL
|EXT4_APPEND_FL
|
3586 EXT4_IMMUTABLE_FL
|EXT4_NOATIME_FL
|
3588 if (vfs_fl
& S_SYNC
)
3589 new_fl
|= EXT4_SYNC_FL
;
3590 if (vfs_fl
& S_APPEND
)
3591 new_fl
|= EXT4_APPEND_FL
;
3592 if (vfs_fl
& S_IMMUTABLE
)
3593 new_fl
|= EXT4_IMMUTABLE_FL
;
3594 if (vfs_fl
& S_NOATIME
)
3595 new_fl
|= EXT4_NOATIME_FL
;
3596 if (vfs_fl
& S_DIRSYNC
)
3597 new_fl
|= EXT4_DIRSYNC_FL
;
3598 } while (cmpxchg(&ei
->i_flags
, old_fl
, new_fl
) != old_fl
);
3601 static blkcnt_t
ext4_inode_blocks(struct ext4_inode
*raw_inode
,
3602 struct ext4_inode_info
*ei
)
3605 struct inode
*inode
= &(ei
->vfs_inode
);
3606 struct super_block
*sb
= inode
->i_sb
;
3608 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
3609 EXT4_FEATURE_RO_COMPAT_HUGE_FILE
)) {
3610 /* we are using combined 48 bit field */
3611 i_blocks
= ((u64
)le16_to_cpu(raw_inode
->i_blocks_high
)) << 32 |
3612 le32_to_cpu(raw_inode
->i_blocks_lo
);
3613 if (ext4_test_inode_flag(inode
, EXT4_INODE_HUGE_FILE
)) {
3614 /* i_blocks represent file system block size */
3615 return i_blocks
<< (inode
->i_blkbits
- 9);
3620 return le32_to_cpu(raw_inode
->i_blocks_lo
);
3624 struct inode
*ext4_iget(struct super_block
*sb
, unsigned long ino
)
3626 struct ext4_iloc iloc
;
3627 struct ext4_inode
*raw_inode
;
3628 struct ext4_inode_info
*ei
;
3629 struct inode
*inode
;
3630 journal_t
*journal
= EXT4_SB(sb
)->s_journal
;
3636 inode
= iget_locked(sb
, ino
);
3638 return ERR_PTR(-ENOMEM
);
3639 if (!(inode
->i_state
& I_NEW
))
3645 ret
= __ext4_get_inode_loc(inode
, &iloc
, 0);
3648 raw_inode
= ext4_raw_inode(&iloc
);
3649 inode
->i_mode
= le16_to_cpu(raw_inode
->i_mode
);
3650 i_uid
= (uid_t
)le16_to_cpu(raw_inode
->i_uid_low
);
3651 i_gid
= (gid_t
)le16_to_cpu(raw_inode
->i_gid_low
);
3652 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
3653 i_uid
|= le16_to_cpu(raw_inode
->i_uid_high
) << 16;
3654 i_gid
|= le16_to_cpu(raw_inode
->i_gid_high
) << 16;
3656 i_uid_write(inode
, i_uid
);
3657 i_gid_write(inode
, i_gid
);
3658 set_nlink(inode
, le16_to_cpu(raw_inode
->i_links_count
));
3660 ext4_clear_state_flags(ei
); /* Only relevant on 32-bit archs */
3661 ei
->i_dir_start_lookup
= 0;
3662 ei
->i_dtime
= le32_to_cpu(raw_inode
->i_dtime
);
3663 /* We now have enough fields to check if the inode was active or not.
3664 * This is needed because nfsd might try to access dead inodes
3665 * the test is that same one that e2fsck uses
3666 * NeilBrown 1999oct15
3668 if (inode
->i_nlink
== 0) {
3669 if (inode
->i_mode
== 0 ||
3670 !(EXT4_SB(inode
->i_sb
)->s_mount_state
& EXT4_ORPHAN_FS
)) {
3671 /* this inode is deleted */
3675 /* The only unlinked inodes we let through here have
3676 * valid i_mode and are being read by the orphan
3677 * recovery code: that's fine, we're about to complete
3678 * the process of deleting those. */
3680 ei
->i_flags
= le32_to_cpu(raw_inode
->i_flags
);
3681 inode
->i_blocks
= ext4_inode_blocks(raw_inode
, ei
);
3682 ei
->i_file_acl
= le32_to_cpu(raw_inode
->i_file_acl_lo
);
3683 if (EXT4_HAS_INCOMPAT_FEATURE(sb
, EXT4_FEATURE_INCOMPAT_64BIT
))
3685 ((__u64
)le16_to_cpu(raw_inode
->i_file_acl_high
)) << 32;
3686 inode
->i_size
= ext4_isize(raw_inode
);
3687 ei
->i_disksize
= inode
->i_size
;
3689 ei
->i_reserved_quota
= 0;
3691 inode
->i_generation
= le32_to_cpu(raw_inode
->i_generation
);
3692 ei
->i_block_group
= iloc
.block_group
;
3693 ei
->i_last_alloc_group
= ~0;
3695 * NOTE! The in-memory inode i_data array is in little-endian order
3696 * even on big-endian machines: we do NOT byteswap the block numbers!
3698 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
3699 ei
->i_data
[block
] = raw_inode
->i_block
[block
];
3700 INIT_LIST_HEAD(&ei
->i_orphan
);
3703 * Set transaction id's of transactions that have to be committed
3704 * to finish f[data]sync. We set them to currently running transaction
3705 * as we cannot be sure that the inode or some of its metadata isn't
3706 * part of the transaction - the inode could have been reclaimed and
3707 * now it is reread from disk.
3710 transaction_t
*transaction
;
3713 read_lock(&journal
->j_state_lock
);
3714 if (journal
->j_running_transaction
)
3715 transaction
= journal
->j_running_transaction
;
3717 transaction
= journal
->j_committing_transaction
;
3719 tid
= transaction
->t_tid
;
3721 tid
= journal
->j_commit_sequence
;
3722 read_unlock(&journal
->j_state_lock
);
3723 ei
->i_sync_tid
= tid
;
3724 ei
->i_datasync_tid
= tid
;
3727 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
3728 ei
->i_extra_isize
= le16_to_cpu(raw_inode
->i_extra_isize
);
3729 if (EXT4_GOOD_OLD_INODE_SIZE
+ ei
->i_extra_isize
>
3730 EXT4_INODE_SIZE(inode
->i_sb
)) {
3734 if (ei
->i_extra_isize
== 0) {
3735 /* The extra space is currently unused. Use it. */
3736 ei
->i_extra_isize
= sizeof(struct ext4_inode
) -
3737 EXT4_GOOD_OLD_INODE_SIZE
;
3739 __le32
*magic
= (void *)raw_inode
+
3740 EXT4_GOOD_OLD_INODE_SIZE
+
3742 if (*magic
== cpu_to_le32(EXT4_XATTR_MAGIC
))
3743 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
3746 ei
->i_extra_isize
= 0;
3748 EXT4_INODE_GET_XTIME(i_ctime
, inode
, raw_inode
);
3749 EXT4_INODE_GET_XTIME(i_mtime
, inode
, raw_inode
);
3750 EXT4_INODE_GET_XTIME(i_atime
, inode
, raw_inode
);
3751 EXT4_EINODE_GET_XTIME(i_crtime
, ei
, raw_inode
);
3753 inode
->i_version
= le32_to_cpu(raw_inode
->i_disk_version
);
3754 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
3755 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
3757 (__u64
)(le32_to_cpu(raw_inode
->i_version_hi
)) << 32;
3761 if (ei
->i_file_acl
&&
3762 !ext4_data_block_valid(EXT4_SB(sb
), ei
->i_file_acl
, 1)) {
3763 EXT4_ERROR_INODE(inode
, "bad extended attribute block %llu",
3767 } else if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) {
3768 if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
3769 (S_ISLNK(inode
->i_mode
) &&
3770 !ext4_inode_is_fast_symlink(inode
)))
3771 /* Validate extent which is part of inode */
3772 ret
= ext4_ext_check_inode(inode
);
3773 } else if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
3774 (S_ISLNK(inode
->i_mode
) &&
3775 !ext4_inode_is_fast_symlink(inode
))) {
3776 /* Validate block references which are part of inode */
3777 ret
= ext4_ind_check_inode(inode
);
3782 if (S_ISREG(inode
->i_mode
)) {
3783 inode
->i_op
= &ext4_file_inode_operations
;
3784 inode
->i_fop
= &ext4_file_operations
;
3785 ext4_set_aops(inode
);
3786 } else if (S_ISDIR(inode
->i_mode
)) {
3787 inode
->i_op
= &ext4_dir_inode_operations
;
3788 inode
->i_fop
= &ext4_dir_operations
;
3789 } else if (S_ISLNK(inode
->i_mode
)) {
3790 if (ext4_inode_is_fast_symlink(inode
)) {
3791 inode
->i_op
= &ext4_fast_symlink_inode_operations
;
3792 nd_terminate_link(ei
->i_data
, inode
->i_size
,
3793 sizeof(ei
->i_data
) - 1);
3795 inode
->i_op
= &ext4_symlink_inode_operations
;
3796 ext4_set_aops(inode
);
3798 } else if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
) ||
3799 S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
3800 inode
->i_op
= &ext4_special_inode_operations
;
3801 if (raw_inode
->i_block
[0])
3802 init_special_inode(inode
, inode
->i_mode
,
3803 old_decode_dev(le32_to_cpu(raw_inode
->i_block
[0])));
3805 init_special_inode(inode
, inode
->i_mode
,
3806 new_decode_dev(le32_to_cpu(raw_inode
->i_block
[1])));
3809 EXT4_ERROR_INODE(inode
, "bogus i_mode (%o)", inode
->i_mode
);
3813 ext4_set_inode_flags(inode
);
3814 unlock_new_inode(inode
);
3820 return ERR_PTR(ret
);
3823 static int ext4_inode_blocks_set(handle_t
*handle
,
3824 struct ext4_inode
*raw_inode
,
3825 struct ext4_inode_info
*ei
)
3827 struct inode
*inode
= &(ei
->vfs_inode
);
3828 u64 i_blocks
= inode
->i_blocks
;
3829 struct super_block
*sb
= inode
->i_sb
;
3831 if (i_blocks
<= ~0U) {
3833 * i_blocks can be represnted in a 32 bit variable
3834 * as multiple of 512 bytes
3836 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
3837 raw_inode
->i_blocks_high
= 0;
3838 ext4_clear_inode_flag(inode
, EXT4_INODE_HUGE_FILE
);
3841 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
, EXT4_FEATURE_RO_COMPAT_HUGE_FILE
))
3844 if (i_blocks
<= 0xffffffffffffULL
) {
3846 * i_blocks can be represented in a 48 bit variable
3847 * as multiple of 512 bytes
3849 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
3850 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
3851 ext4_clear_inode_flag(inode
, EXT4_INODE_HUGE_FILE
);
3853 ext4_set_inode_flag(inode
, EXT4_INODE_HUGE_FILE
);
3854 /* i_block is stored in file system block size */
3855 i_blocks
= i_blocks
>> (inode
->i_blkbits
- 9);
3856 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
3857 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
3863 * Post the struct inode info into an on-disk inode location in the
3864 * buffer-cache. This gobbles the caller's reference to the
3865 * buffer_head in the inode location struct.
3867 * The caller must have write access to iloc->bh.
3869 static int ext4_do_update_inode(handle_t
*handle
,
3870 struct inode
*inode
,
3871 struct ext4_iloc
*iloc
)
3873 struct ext4_inode
*raw_inode
= ext4_raw_inode(iloc
);
3874 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3875 struct buffer_head
*bh
= iloc
->bh
;
3876 int err
= 0, rc
, block
;
3880 /* For fields not not tracking in the in-memory inode,
3881 * initialise them to zero for new inodes. */
3882 if (ext4_test_inode_state(inode
, EXT4_STATE_NEW
))
3883 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
3885 ext4_get_inode_flags(ei
);
3886 raw_inode
->i_mode
= cpu_to_le16(inode
->i_mode
);
3887 i_uid
= i_uid_read(inode
);
3888 i_gid
= i_gid_read(inode
);
3889 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
3890 raw_inode
->i_uid_low
= cpu_to_le16(low_16_bits(i_uid
));
3891 raw_inode
->i_gid_low
= cpu_to_le16(low_16_bits(i_gid
));
3893 * Fix up interoperability with old kernels. Otherwise, old inodes get
3894 * re-used with the upper 16 bits of the uid/gid intact
3897 raw_inode
->i_uid_high
=
3898 cpu_to_le16(high_16_bits(i_uid
));
3899 raw_inode
->i_gid_high
=
3900 cpu_to_le16(high_16_bits(i_gid
));
3902 raw_inode
->i_uid_high
= 0;
3903 raw_inode
->i_gid_high
= 0;
3906 raw_inode
->i_uid_low
= cpu_to_le16(fs_high2lowuid(i_uid
));
3907 raw_inode
->i_gid_low
= cpu_to_le16(fs_high2lowgid(i_gid
));
3908 raw_inode
->i_uid_high
= 0;
3909 raw_inode
->i_gid_high
= 0;
3911 raw_inode
->i_links_count
= cpu_to_le16(inode
->i_nlink
);
3913 EXT4_INODE_SET_XTIME(i_ctime
, inode
, raw_inode
);
3914 EXT4_INODE_SET_XTIME(i_mtime
, inode
, raw_inode
);
3915 EXT4_INODE_SET_XTIME(i_atime
, inode
, raw_inode
);
3916 EXT4_EINODE_SET_XTIME(i_crtime
, ei
, raw_inode
);
3918 if (ext4_inode_blocks_set(handle
, raw_inode
, ei
))
3920 raw_inode
->i_dtime
= cpu_to_le32(ei
->i_dtime
);
3921 raw_inode
->i_flags
= cpu_to_le32(ei
->i_flags
& 0xFFFFFFFF);
3922 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
3923 cpu_to_le32(EXT4_OS_HURD
))
3924 raw_inode
->i_file_acl_high
=
3925 cpu_to_le16(ei
->i_file_acl
>> 32);
3926 raw_inode
->i_file_acl_lo
= cpu_to_le32(ei
->i_file_acl
);
3927 ext4_isize_set(raw_inode
, ei
->i_disksize
);
3928 if (ei
->i_disksize
> 0x7fffffffULL
) {
3929 struct super_block
*sb
= inode
->i_sb
;
3930 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
,
3931 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
) ||
3932 EXT4_SB(sb
)->s_es
->s_rev_level
==
3933 cpu_to_le32(EXT4_GOOD_OLD_REV
)) {
3934 /* If this is the first large file
3935 * created, add a flag to the superblock.
3937 err
= ext4_journal_get_write_access(handle
,
3938 EXT4_SB(sb
)->s_sbh
);
3941 ext4_update_dynamic_rev(sb
);
3942 EXT4_SET_RO_COMPAT_FEATURE(sb
,
3943 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
);
3944 ext4_handle_sync(handle
);
3945 err
= ext4_handle_dirty_super(handle
, sb
);
3948 raw_inode
->i_generation
= cpu_to_le32(inode
->i_generation
);
3949 if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
)) {
3950 if (old_valid_dev(inode
->i_rdev
)) {
3951 raw_inode
->i_block
[0] =
3952 cpu_to_le32(old_encode_dev(inode
->i_rdev
));
3953 raw_inode
->i_block
[1] = 0;
3955 raw_inode
->i_block
[0] = 0;
3956 raw_inode
->i_block
[1] =
3957 cpu_to_le32(new_encode_dev(inode
->i_rdev
));
3958 raw_inode
->i_block
[2] = 0;
3961 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
3962 raw_inode
->i_block
[block
] = ei
->i_data
[block
];
3964 raw_inode
->i_disk_version
= cpu_to_le32(inode
->i_version
);
3965 if (ei
->i_extra_isize
) {
3966 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
3967 raw_inode
->i_version_hi
=
3968 cpu_to_le32(inode
->i_version
>> 32);
3969 raw_inode
->i_extra_isize
= cpu_to_le16(ei
->i_extra_isize
);
3972 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
3973 rc
= ext4_handle_dirty_metadata(handle
, NULL
, bh
);
3976 ext4_clear_inode_state(inode
, EXT4_STATE_NEW
);
3978 ext4_update_inode_fsync_trans(handle
, inode
, 0);
3981 ext4_std_error(inode
->i_sb
, err
);
3986 * ext4_write_inode()
3988 * We are called from a few places:
3990 * - Within generic_file_write() for O_SYNC files.
3991 * Here, there will be no transaction running. We wait for any running
3992 * trasnaction to commit.
3994 * - Within sys_sync(), kupdate and such.
3995 * We wait on commit, if tol to.
3997 * - Within prune_icache() (PF_MEMALLOC == true)
3998 * Here we simply return. We can't afford to block kswapd on the
4001 * In all cases it is actually safe for us to return without doing anything,
4002 * because the inode has been copied into a raw inode buffer in
4003 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
4006 * Note that we are absolutely dependent upon all inode dirtiers doing the
4007 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4008 * which we are interested.
4010 * It would be a bug for them to not do this. The code:
4012 * mark_inode_dirty(inode)
4014 * inode->i_size = expr;
4016 * is in error because a kswapd-driven write_inode() could occur while
4017 * `stuff()' is running, and the new i_size will be lost. Plus the inode
4018 * will no longer be on the superblock's dirty inode list.
4020 int ext4_write_inode(struct inode
*inode
, struct writeback_control
*wbc
)
4024 if (current
->flags
& PF_MEMALLOC
)
4027 if (EXT4_SB(inode
->i_sb
)->s_journal
) {
4028 if (ext4_journal_current_handle()) {
4029 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
4034 if (wbc
->sync_mode
!= WB_SYNC_ALL
)
4037 err
= ext4_force_commit(inode
->i_sb
);
4039 struct ext4_iloc iloc
;
4041 err
= __ext4_get_inode_loc(inode
, &iloc
, 0);
4044 if (wbc
->sync_mode
== WB_SYNC_ALL
)
4045 sync_dirty_buffer(iloc
.bh
);
4046 if (buffer_req(iloc
.bh
) && !buffer_uptodate(iloc
.bh
)) {
4047 EXT4_ERROR_INODE_BLOCK(inode
, iloc
.bh
->b_blocknr
,
4048 "IO error syncing inode");
4059 * Called from notify_change.
4061 * We want to trap VFS attempts to truncate the file as soon as
4062 * possible. In particular, we want to make sure that when the VFS
4063 * shrinks i_size, we put the inode on the orphan list and modify
4064 * i_disksize immediately, so that during the subsequent flushing of
4065 * dirty pages and freeing of disk blocks, we can guarantee that any
4066 * commit will leave the blocks being flushed in an unused state on
4067 * disk. (On recovery, the inode will get truncated and the blocks will
4068 * be freed, so we have a strong guarantee that no future commit will
4069 * leave these blocks visible to the user.)
4071 * Another thing we have to assure is that if we are in ordered mode
4072 * and inode is still attached to the committing transaction, we must
4073 * we start writeout of all the dirty pages which are being truncated.
4074 * This way we are sure that all the data written in the previous
4075 * transaction are already on disk (truncate waits for pages under
4078 * Called with inode->i_mutex down.
4080 int ext4_setattr(struct dentry
*dentry
, struct iattr
*attr
)
4082 struct inode
*inode
= dentry
->d_inode
;
4085 const unsigned int ia_valid
= attr
->ia_valid
;
4087 error
= inode_change_ok(inode
, attr
);
4091 if (is_quota_modification(inode
, attr
))
4092 dquot_initialize(inode
);
4093 if ((ia_valid
& ATTR_UID
&& !uid_eq(attr
->ia_uid
, inode
->i_uid
)) ||
4094 (ia_valid
& ATTR_GID
&& !gid_eq(attr
->ia_gid
, inode
->i_gid
))) {
4097 /* (user+group)*(old+new) structure, inode write (sb,
4098 * inode block, ? - but truncate inode update has it) */
4099 handle
= ext4_journal_start(inode
, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode
->i_sb
)+
4100 EXT4_MAXQUOTAS_DEL_BLOCKS(inode
->i_sb
))+3);
4101 if (IS_ERR(handle
)) {
4102 error
= PTR_ERR(handle
);
4105 error
= dquot_transfer(inode
, attr
);
4107 ext4_journal_stop(handle
);
4110 /* Update corresponding info in inode so that everything is in
4111 * one transaction */
4112 if (attr
->ia_valid
& ATTR_UID
)
4113 inode
->i_uid
= attr
->ia_uid
;
4114 if (attr
->ia_valid
& ATTR_GID
)
4115 inode
->i_gid
= attr
->ia_gid
;
4116 error
= ext4_mark_inode_dirty(handle
, inode
);
4117 ext4_journal_stop(handle
);
4120 if (attr
->ia_valid
& ATTR_SIZE
) {
4121 inode_dio_wait(inode
);
4123 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
))) {
4124 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
4126 if (attr
->ia_size
> sbi
->s_bitmap_maxbytes
)
4131 if (S_ISREG(inode
->i_mode
) &&
4132 attr
->ia_valid
& ATTR_SIZE
&&
4133 (attr
->ia_size
< inode
->i_size
)) {
4136 handle
= ext4_journal_start(inode
, 3);
4137 if (IS_ERR(handle
)) {
4138 error
= PTR_ERR(handle
);
4141 if (ext4_handle_valid(handle
)) {
4142 error
= ext4_orphan_add(handle
, inode
);
4145 EXT4_I(inode
)->i_disksize
= attr
->ia_size
;
4146 rc
= ext4_mark_inode_dirty(handle
, inode
);
4149 ext4_journal_stop(handle
);
4151 if (ext4_should_order_data(inode
)) {
4152 error
= ext4_begin_ordered_truncate(inode
,
4155 /* Do as much error cleanup as possible */
4156 handle
= ext4_journal_start(inode
, 3);
4157 if (IS_ERR(handle
)) {
4158 ext4_orphan_del(NULL
, inode
);
4161 ext4_orphan_del(handle
, inode
);
4163 ext4_journal_stop(handle
);
4169 if (attr
->ia_valid
& ATTR_SIZE
) {
4170 if (attr
->ia_size
!= i_size_read(inode
))
4171 truncate_setsize(inode
, attr
->ia_size
);
4172 ext4_truncate(inode
);
4176 setattr_copy(inode
, attr
);
4177 mark_inode_dirty(inode
);
4181 * If the call to ext4_truncate failed to get a transaction handle at
4182 * all, we need to clean up the in-core orphan list manually.
4184 if (orphan
&& inode
->i_nlink
)
4185 ext4_orphan_del(NULL
, inode
);
4187 if (!rc
&& (ia_valid
& ATTR_MODE
))
4188 rc
= ext4_acl_chmod(inode
);
4191 ext4_std_error(inode
->i_sb
, error
);
4197 int ext4_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
4200 struct inode
*inode
;
4201 unsigned long delalloc_blocks
;
4203 inode
= dentry
->d_inode
;
4204 generic_fillattr(inode
, stat
);
4207 * We can't update i_blocks if the block allocation is delayed
4208 * otherwise in the case of system crash before the real block
4209 * allocation is done, we will have i_blocks inconsistent with
4210 * on-disk file blocks.
4211 * We always keep i_blocks updated together with real
4212 * allocation. But to not confuse with user, stat
4213 * will return the blocks that include the delayed allocation
4214 * blocks for this file.
4216 delalloc_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
4218 stat
->blocks
+= (delalloc_blocks
<< inode
->i_sb
->s_blocksize_bits
)>>9;
4222 static int ext4_index_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
4224 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
4225 return ext4_ind_trans_blocks(inode
, nrblocks
, chunk
);
4226 return ext4_ext_index_trans_blocks(inode
, nrblocks
, chunk
);
4230 * Account for index blocks, block groups bitmaps and block group
4231 * descriptor blocks if modify datablocks and index blocks
4232 * worse case, the indexs blocks spread over different block groups
4234 * If datablocks are discontiguous, they are possible to spread over
4235 * different block groups too. If they are contiuguous, with flexbg,
4236 * they could still across block group boundary.
4238 * Also account for superblock, inode, quota and xattr blocks
4240 static int ext4_meta_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
4242 ext4_group_t groups
, ngroups
= ext4_get_groups_count(inode
->i_sb
);
4248 * How many index blocks need to touch to modify nrblocks?
4249 * The "Chunk" flag indicating whether the nrblocks is
4250 * physically contiguous on disk
4252 * For Direct IO and fallocate, they calls get_block to allocate
4253 * one single extent at a time, so they could set the "Chunk" flag
4255 idxblocks
= ext4_index_trans_blocks(inode
, nrblocks
, chunk
);
4260 * Now let's see how many group bitmaps and group descriptors need
4270 if (groups
> ngroups
)
4272 if (groups
> EXT4_SB(inode
->i_sb
)->s_gdb_count
)
4273 gdpblocks
= EXT4_SB(inode
->i_sb
)->s_gdb_count
;
4275 /* bitmaps and block group descriptor blocks */
4276 ret
+= groups
+ gdpblocks
;
4278 /* Blocks for super block, inode, quota and xattr blocks */
4279 ret
+= EXT4_META_TRANS_BLOCKS(inode
->i_sb
);
4285 * Calculate the total number of credits to reserve to fit
4286 * the modification of a single pages into a single transaction,
4287 * which may include multiple chunks of block allocations.
4289 * This could be called via ext4_write_begin()
4291 * We need to consider the worse case, when
4292 * one new block per extent.
4294 int ext4_writepage_trans_blocks(struct inode
*inode
)
4296 int bpp
= ext4_journal_blocks_per_page(inode
);
4299 ret
= ext4_meta_trans_blocks(inode
, bpp
, 0);
4301 /* Account for data blocks for journalled mode */
4302 if (ext4_should_journal_data(inode
))
4308 * Calculate the journal credits for a chunk of data modification.
4310 * This is called from DIO, fallocate or whoever calling
4311 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
4313 * journal buffers for data blocks are not included here, as DIO
4314 * and fallocate do no need to journal data buffers.
4316 int ext4_chunk_trans_blocks(struct inode
*inode
, int nrblocks
)
4318 return ext4_meta_trans_blocks(inode
, nrblocks
, 1);
4322 * The caller must have previously called ext4_reserve_inode_write().
4323 * Give this, we know that the caller already has write access to iloc->bh.
4325 int ext4_mark_iloc_dirty(handle_t
*handle
,
4326 struct inode
*inode
, struct ext4_iloc
*iloc
)
4330 if (IS_I_VERSION(inode
))
4331 inode_inc_iversion(inode
);
4333 /* the do_update_inode consumes one bh->b_count */
4336 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
4337 err
= ext4_do_update_inode(handle
, inode
, iloc
);
4343 * On success, We end up with an outstanding reference count against
4344 * iloc->bh. This _must_ be cleaned up later.
4348 ext4_reserve_inode_write(handle_t
*handle
, struct inode
*inode
,
4349 struct ext4_iloc
*iloc
)
4353 err
= ext4_get_inode_loc(inode
, iloc
);
4355 BUFFER_TRACE(iloc
->bh
, "get_write_access");
4356 err
= ext4_journal_get_write_access(handle
, iloc
->bh
);
4362 ext4_std_error(inode
->i_sb
, err
);
4367 * Expand an inode by new_extra_isize bytes.
4368 * Returns 0 on success or negative error number on failure.
4370 static int ext4_expand_extra_isize(struct inode
*inode
,
4371 unsigned int new_extra_isize
,
4372 struct ext4_iloc iloc
,
4375 struct ext4_inode
*raw_inode
;
4376 struct ext4_xattr_ibody_header
*header
;
4378 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
)
4381 raw_inode
= ext4_raw_inode(&iloc
);
4383 header
= IHDR(inode
, raw_inode
);
4385 /* No extended attributes present */
4386 if (!ext4_test_inode_state(inode
, EXT4_STATE_XATTR
) ||
4387 header
->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
)) {
4388 memset((void *)raw_inode
+ EXT4_GOOD_OLD_INODE_SIZE
, 0,
4390 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
4394 /* try to expand with EAs present */
4395 return ext4_expand_extra_isize_ea(inode
, new_extra_isize
,
4400 * What we do here is to mark the in-core inode as clean with respect to inode
4401 * dirtiness (it may still be data-dirty).
4402 * This means that the in-core inode may be reaped by prune_icache
4403 * without having to perform any I/O. This is a very good thing,
4404 * because *any* task may call prune_icache - even ones which
4405 * have a transaction open against a different journal.
4407 * Is this cheating? Not really. Sure, we haven't written the
4408 * inode out, but prune_icache isn't a user-visible syncing function.
4409 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
4410 * we start and wait on commits.
4412 * Is this efficient/effective? Well, we're being nice to the system
4413 * by cleaning up our inodes proactively so they can be reaped
4414 * without I/O. But we are potentially leaving up to five seconds'
4415 * worth of inodes floating about which prune_icache wants us to
4416 * write out. One way to fix that would be to get prune_icache()
4417 * to do a write_super() to free up some memory. It has the desired
4420 int ext4_mark_inode_dirty(handle_t
*handle
, struct inode
*inode
)
4422 struct ext4_iloc iloc
;
4423 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
4424 static unsigned int mnt_count
;
4428 trace_ext4_mark_inode_dirty(inode
, _RET_IP_
);
4429 err
= ext4_reserve_inode_write(handle
, inode
, &iloc
);
4430 if (ext4_handle_valid(handle
) &&
4431 EXT4_I(inode
)->i_extra_isize
< sbi
->s_want_extra_isize
&&
4432 !ext4_test_inode_state(inode
, EXT4_STATE_NO_EXPAND
)) {
4434 * We need extra buffer credits since we may write into EA block
4435 * with this same handle. If journal_extend fails, then it will
4436 * only result in a minor loss of functionality for that inode.
4437 * If this is felt to be critical, then e2fsck should be run to
4438 * force a large enough s_min_extra_isize.
4440 if ((jbd2_journal_extend(handle
,
4441 EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
))) == 0) {
4442 ret
= ext4_expand_extra_isize(inode
,
4443 sbi
->s_want_extra_isize
,
4446 ext4_set_inode_state(inode
,
4447 EXT4_STATE_NO_EXPAND
);
4449 le16_to_cpu(sbi
->s_es
->s_mnt_count
)) {
4450 ext4_warning(inode
->i_sb
,
4451 "Unable to expand inode %lu. Delete"
4452 " some EAs or run e2fsck.",
4455 le16_to_cpu(sbi
->s_es
->s_mnt_count
);
4461 err
= ext4_mark_iloc_dirty(handle
, inode
, &iloc
);
4466 * ext4_dirty_inode() is called from __mark_inode_dirty()
4468 * We're really interested in the case where a file is being extended.
4469 * i_size has been changed by generic_commit_write() and we thus need
4470 * to include the updated inode in the current transaction.
4472 * Also, dquot_alloc_block() will always dirty the inode when blocks
4473 * are allocated to the file.
4475 * If the inode is marked synchronous, we don't honour that here - doing
4476 * so would cause a commit on atime updates, which we don't bother doing.
4477 * We handle synchronous inodes at the highest possible level.
4479 void ext4_dirty_inode(struct inode
*inode
, int flags
)
4483 handle
= ext4_journal_start(inode
, 2);
4487 ext4_mark_inode_dirty(handle
, inode
);
4489 ext4_journal_stop(handle
);
4496 * Bind an inode's backing buffer_head into this transaction, to prevent
4497 * it from being flushed to disk early. Unlike
4498 * ext4_reserve_inode_write, this leaves behind no bh reference and
4499 * returns no iloc structure, so the caller needs to repeat the iloc
4500 * lookup to mark the inode dirty later.
4502 static int ext4_pin_inode(handle_t
*handle
, struct inode
*inode
)
4504 struct ext4_iloc iloc
;
4508 err
= ext4_get_inode_loc(inode
, &iloc
);
4510 BUFFER_TRACE(iloc
.bh
, "get_write_access");
4511 err
= jbd2_journal_get_write_access(handle
, iloc
.bh
);
4513 err
= ext4_handle_dirty_metadata(handle
,
4519 ext4_std_error(inode
->i_sb
, err
);
4524 int ext4_change_inode_journal_flag(struct inode
*inode
, int val
)
4531 * We have to be very careful here: changing a data block's
4532 * journaling status dynamically is dangerous. If we write a
4533 * data block to the journal, change the status and then delete
4534 * that block, we risk forgetting to revoke the old log record
4535 * from the journal and so a subsequent replay can corrupt data.
4536 * So, first we make sure that the journal is empty and that
4537 * nobody is changing anything.
4540 journal
= EXT4_JOURNAL(inode
);
4543 if (is_journal_aborted(journal
))
4545 /* We have to allocate physical blocks for delalloc blocks
4546 * before flushing journal. otherwise delalloc blocks can not
4547 * be allocated any more. even more truncate on delalloc blocks
4548 * could trigger BUG by flushing delalloc blocks in journal.
4549 * There is no delalloc block in non-journal data mode.
4551 if (val
&& test_opt(inode
->i_sb
, DELALLOC
)) {
4552 err
= ext4_alloc_da_blocks(inode
);
4557 jbd2_journal_lock_updates(journal
);
4560 * OK, there are no updates running now, and all cached data is
4561 * synced to disk. We are now in a completely consistent state
4562 * which doesn't have anything in the journal, and we know that
4563 * no filesystem updates are running, so it is safe to modify
4564 * the inode's in-core data-journaling state flag now.
4568 ext4_set_inode_flag(inode
, EXT4_INODE_JOURNAL_DATA
);
4570 jbd2_journal_flush(journal
);
4571 ext4_clear_inode_flag(inode
, EXT4_INODE_JOURNAL_DATA
);
4573 ext4_set_aops(inode
);
4575 jbd2_journal_unlock_updates(journal
);
4577 /* Finally we can mark the inode as dirty. */
4579 handle
= ext4_journal_start(inode
, 1);
4581 return PTR_ERR(handle
);
4583 err
= ext4_mark_inode_dirty(handle
, inode
);
4584 ext4_handle_sync(handle
);
4585 ext4_journal_stop(handle
);
4586 ext4_std_error(inode
->i_sb
, err
);
4591 static int ext4_bh_unmapped(handle_t
*handle
, struct buffer_head
*bh
)
4593 return !buffer_mapped(bh
);
4596 int ext4_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4598 struct page
*page
= vmf
->page
;
4602 struct file
*file
= vma
->vm_file
;
4603 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
4604 struct address_space
*mapping
= inode
->i_mapping
;
4606 get_block_t
*get_block
;
4610 * This check is racy but catches the common case. We rely on
4611 * __block_page_mkwrite() to do a reliable check.
4613 vfs_check_frozen(inode
->i_sb
, SB_FREEZE_WRITE
);
4614 /* Delalloc case is easy... */
4615 if (test_opt(inode
->i_sb
, DELALLOC
) &&
4616 !ext4_should_journal_data(inode
) &&
4617 !ext4_nonda_switch(inode
->i_sb
)) {
4619 ret
= __block_page_mkwrite(vma
, vmf
,
4620 ext4_da_get_block_prep
);
4621 } while (ret
== -ENOSPC
&&
4622 ext4_should_retry_alloc(inode
->i_sb
, &retries
));
4627 size
= i_size_read(inode
);
4628 /* Page got truncated from under us? */
4629 if (page
->mapping
!= mapping
|| page_offset(page
) > size
) {
4631 ret
= VM_FAULT_NOPAGE
;
4635 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
4636 len
= size
& ~PAGE_CACHE_MASK
;
4638 len
= PAGE_CACHE_SIZE
;
4640 * Return if we have all the buffers mapped. This avoids the need to do
4641 * journal_start/journal_stop which can block and take a long time
4643 if (page_has_buffers(page
)) {
4644 if (!walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
4645 ext4_bh_unmapped
)) {
4646 /* Wait so that we don't change page under IO */
4647 wait_on_page_writeback(page
);
4648 ret
= VM_FAULT_LOCKED
;
4653 /* OK, we need to fill the hole... */
4654 if (ext4_should_dioread_nolock(inode
))
4655 get_block
= ext4_get_block_write
;
4657 get_block
= ext4_get_block
;
4659 handle
= ext4_journal_start(inode
, ext4_writepage_trans_blocks(inode
));
4660 if (IS_ERR(handle
)) {
4661 ret
= VM_FAULT_SIGBUS
;
4664 ret
= __block_page_mkwrite(vma
, vmf
, get_block
);
4665 if (!ret
&& ext4_should_journal_data(inode
)) {
4666 if (walk_page_buffers(handle
, page_buffers(page
), 0,
4667 PAGE_CACHE_SIZE
, NULL
, do_journal_get_write_access
)) {
4669 ret
= VM_FAULT_SIGBUS
;
4670 ext4_journal_stop(handle
);
4673 ext4_set_inode_state(inode
, EXT4_STATE_JDATA
);
4675 ext4_journal_stop(handle
);
4676 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
4679 ret
= block_page_mkwrite_return(ret
);