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 __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw,
51 struct ext4_inode_info *ei)
53 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
58 csum_lo = raw->i_checksum_lo;
59 raw->i_checksum_lo = 0;
60 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
61 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) {
62 csum_hi = raw->i_checksum_hi;
63 raw->i_checksum_hi = 0;
66 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)raw,
67 EXT4_INODE_SIZE(inode->i_sb));
69 raw->i_checksum_lo = csum_lo;
70 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
71 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
72 raw->i_checksum_hi = csum_hi;
77 static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw,
78 struct ext4_inode_info *ei)
80 __u32 provided, calculated;
82 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
83 cpu_to_le32(EXT4_OS_LINUX) ||
84 !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
85 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
88 provided = le16_to_cpu(raw->i_checksum_lo);
89 calculated = ext4_inode_csum(inode, raw, ei);
90 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
91 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
92 provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16;
96 return provided == calculated;
99 static void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw,
100 struct ext4_inode_info *ei)
104 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
105 cpu_to_le32(EXT4_OS_LINUX) ||
106 !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
107 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
110 csum = ext4_inode_csum(inode, raw, ei);
111 raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF);
112 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
113 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
114 raw->i_checksum_hi = cpu_to_le16(csum >> 16);
117 static inline int ext4_begin_ordered_truncate(struct inode *inode,
120 trace_ext4_begin_ordered_truncate(inode, new_size);
122 * If jinode is zero, then we never opened the file for
123 * writing, so there's no need to call
124 * jbd2_journal_begin_ordered_truncate() since there's no
125 * outstanding writes we need to flush.
127 if (!EXT4_I(inode)->jinode)
129 return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode),
130 EXT4_I(inode)->jinode,
134 static void ext4_invalidatepage(struct page *page, unsigned long offset);
135 static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
136 struct buffer_head *bh_result, int create);
137 static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode);
138 static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
139 static int __ext4_journalled_writepage(struct page *page, unsigned int len);
140 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
141 static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
142 struct inode *inode, struct page *page, loff_t from,
143 loff_t length, int flags);
146 * Test whether an inode is a fast symlink.
148 static int ext4_inode_is_fast_symlink(struct inode *inode)
150 int ea_blocks = EXT4_I(inode)->i_file_acl ?
151 (inode->i_sb->s_blocksize >> 9) : 0;
153 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
157 * Restart the transaction associated with *handle. This does a commit,
158 * so before we call here everything must be consistently dirtied against
161 int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
167 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
168 * moment, get_block can be called only for blocks inside i_size since
169 * page cache has been already dropped and writes are blocked by
170 * i_mutex. So we can safely drop the i_data_sem here.
172 BUG_ON(EXT4_JOURNAL(inode) == NULL);
173 jbd_debug(2, "restarting handle %p\n", handle);
174 up_write(&EXT4_I(inode)->i_data_sem);
175 ret = ext4_journal_restart(handle, nblocks);
176 down_write(&EXT4_I(inode)->i_data_sem);
177 ext4_discard_preallocations(inode);
183 * Called at the last iput() if i_nlink is zero.
185 void ext4_evict_inode(struct inode *inode)
190 trace_ext4_evict_inode(inode);
192 ext4_ioend_wait(inode);
194 if (inode->i_nlink) {
196 * When journalling data dirty buffers are tracked only in the
197 * journal. So although mm thinks everything is clean and
198 * ready for reaping the inode might still have some pages to
199 * write in the running transaction or waiting to be
200 * checkpointed. Thus calling jbd2_journal_invalidatepage()
201 * (via truncate_inode_pages()) to discard these buffers can
202 * cause data loss. Also even if we did not discard these
203 * buffers, we would have no way to find them after the inode
204 * is reaped and thus user could see stale data if he tries to
205 * read them before the transaction is checkpointed. So be
206 * careful and force everything to disk here... We use
207 * ei->i_datasync_tid to store the newest transaction
208 * containing inode's data.
210 * Note that directories do not have this problem because they
211 * don't use page cache.
213 if (ext4_should_journal_data(inode) &&
214 (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode))) {
215 journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
216 tid_t commit_tid = EXT4_I(inode)->i_datasync_tid;
218 jbd2_log_start_commit(journal, commit_tid);
219 jbd2_log_wait_commit(journal, commit_tid);
220 filemap_write_and_wait(&inode->i_data);
222 truncate_inode_pages(&inode->i_data, 0);
226 if (!is_bad_inode(inode))
227 dquot_initialize(inode);
229 if (ext4_should_order_data(inode))
230 ext4_begin_ordered_truncate(inode, 0);
231 truncate_inode_pages(&inode->i_data, 0);
233 if (is_bad_inode(inode))
236 handle = ext4_journal_start(inode, ext4_blocks_for_truncate(inode)+3);
237 if (IS_ERR(handle)) {
238 ext4_std_error(inode->i_sb, PTR_ERR(handle));
240 * If we're going to skip the normal cleanup, we still need to
241 * make sure that the in-core orphan linked list is properly
244 ext4_orphan_del(NULL, inode);
249 ext4_handle_sync(handle);
251 err = ext4_mark_inode_dirty(handle, inode);
253 ext4_warning(inode->i_sb,
254 "couldn't mark inode dirty (err %d)", err);
258 ext4_truncate(inode);
261 * ext4_ext_truncate() doesn't reserve any slop when it
262 * restarts journal transactions; therefore there may not be
263 * enough credits left in the handle to remove the inode from
264 * the orphan list and set the dtime field.
266 if (!ext4_handle_has_enough_credits(handle, 3)) {
267 err = ext4_journal_extend(handle, 3);
269 err = ext4_journal_restart(handle, 3);
271 ext4_warning(inode->i_sb,
272 "couldn't extend journal (err %d)", err);
274 ext4_journal_stop(handle);
275 ext4_orphan_del(NULL, inode);
281 * Kill off the orphan record which ext4_truncate created.
282 * AKPM: I think this can be inside the above `if'.
283 * Note that ext4_orphan_del() has to be able to cope with the
284 * deletion of a non-existent orphan - this is because we don't
285 * know if ext4_truncate() actually created an orphan record.
286 * (Well, we could do this if we need to, but heck - it works)
288 ext4_orphan_del(handle, inode);
289 EXT4_I(inode)->i_dtime = get_seconds();
292 * One subtle ordering requirement: if anything has gone wrong
293 * (transaction abort, IO errors, whatever), then we can still
294 * do these next steps (the fs will already have been marked as
295 * having errors), but we can't free the inode if the mark_dirty
298 if (ext4_mark_inode_dirty(handle, inode))
299 /* If that failed, just do the required in-core inode clear. */
300 ext4_clear_inode(inode);
302 ext4_free_inode(handle, inode);
303 ext4_journal_stop(handle);
306 ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
310 qsize_t *ext4_get_reserved_space(struct inode *inode)
312 return &EXT4_I(inode)->i_reserved_quota;
317 * Calculate the number of metadata blocks need to reserve
318 * to allocate a block located at @lblock
320 static int ext4_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
322 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
323 return ext4_ext_calc_metadata_amount(inode, lblock);
325 return ext4_ind_calc_metadata_amount(inode, lblock);
329 * Called with i_data_sem down, which is important since we can call
330 * ext4_discard_preallocations() from here.
332 void ext4_da_update_reserve_space(struct inode *inode,
333 int used, int quota_claim)
335 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
336 struct ext4_inode_info *ei = EXT4_I(inode);
338 spin_lock(&ei->i_block_reservation_lock);
339 trace_ext4_da_update_reserve_space(inode, used, quota_claim);
340 if (unlikely(used > ei->i_reserved_data_blocks)) {
341 ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, used %d "
342 "with only %d reserved data blocks",
343 __func__, inode->i_ino, used,
344 ei->i_reserved_data_blocks);
346 used = ei->i_reserved_data_blocks;
349 if (unlikely(ei->i_allocated_meta_blocks > ei->i_reserved_meta_blocks)) {
350 ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, allocated %d "
351 "with only %d reserved metadata blocks\n", __func__,
352 inode->i_ino, ei->i_allocated_meta_blocks,
353 ei->i_reserved_meta_blocks);
355 ei->i_allocated_meta_blocks = ei->i_reserved_meta_blocks;
358 /* Update per-inode reservations */
359 ei->i_reserved_data_blocks -= used;
360 ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks;
361 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
362 used + ei->i_allocated_meta_blocks);
363 ei->i_allocated_meta_blocks = 0;
365 if (ei->i_reserved_data_blocks == 0) {
367 * We can release all of the reserved metadata blocks
368 * only when we have written all of the delayed
371 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
372 ei->i_reserved_meta_blocks);
373 ei->i_reserved_meta_blocks = 0;
374 ei->i_da_metadata_calc_len = 0;
376 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
378 /* Update quota subsystem for data blocks */
380 dquot_claim_block(inode, EXT4_C2B(sbi, used));
383 * We did fallocate with an offset that is already delayed
384 * allocated. So on delayed allocated writeback we should
385 * not re-claim the quota for fallocated blocks.
387 dquot_release_reservation_block(inode, EXT4_C2B(sbi, used));
391 * If we have done all the pending block allocations and if
392 * there aren't any writers on the inode, we can discard the
393 * inode's preallocations.
395 if ((ei->i_reserved_data_blocks == 0) &&
396 (atomic_read(&inode->i_writecount) == 0))
397 ext4_discard_preallocations(inode);
400 static int __check_block_validity(struct inode *inode, const char *func,
402 struct ext4_map_blocks *map)
404 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
406 ext4_error_inode(inode, func, line, map->m_pblk,
407 "lblock %lu mapped to illegal pblock "
408 "(length %d)", (unsigned long) map->m_lblk,
415 #define check_block_validity(inode, map) \
416 __check_block_validity((inode), __func__, __LINE__, (map))
419 * Return the number of contiguous dirty pages in a given inode
420 * starting at page frame idx.
422 static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
423 unsigned int max_pages)
425 struct address_space *mapping = inode->i_mapping;
429 int i, nr_pages, done = 0;
433 pagevec_init(&pvec, 0);
436 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
438 (pgoff_t)PAGEVEC_SIZE);
441 for (i = 0; i < nr_pages; i++) {
442 struct page *page = pvec.pages[i];
443 struct buffer_head *bh, *head;
446 if (unlikely(page->mapping != mapping) ||
448 PageWriteback(page) ||
449 page->index != idx) {
454 if (page_has_buffers(page)) {
455 bh = head = page_buffers(page);
457 if (!buffer_delay(bh) &&
458 !buffer_unwritten(bh))
460 bh = bh->b_this_page;
461 } while (!done && (bh != head));
468 if (num >= max_pages) {
473 pagevec_release(&pvec);
479 * Sets the BH_Da_Mapped bit on the buffer heads corresponding to the given map.
481 static void set_buffers_da_mapped(struct inode *inode,
482 struct ext4_map_blocks *map)
484 struct address_space *mapping = inode->i_mapping;
489 index = map->m_lblk >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
490 end = (map->m_lblk + map->m_len - 1) >>
491 (PAGE_CACHE_SHIFT - inode->i_blkbits);
493 pagevec_init(&pvec, 0);
494 while (index <= end) {
495 nr_pages = pagevec_lookup(&pvec, mapping, index,
497 (pgoff_t)PAGEVEC_SIZE));
500 for (i = 0; i < nr_pages; i++) {
501 struct page *page = pvec.pages[i];
502 struct buffer_head *bh, *head;
504 if (unlikely(page->mapping != mapping) ||
508 if (page_has_buffers(page)) {
509 bh = head = page_buffers(page);
511 set_buffer_da_mapped(bh);
512 bh = bh->b_this_page;
513 } while (bh != head);
517 pagevec_release(&pvec);
522 * The ext4_map_blocks() function tries to look up the requested blocks,
523 * and returns if the blocks are already mapped.
525 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
526 * and store the allocated blocks in the result buffer head and mark it
529 * If file type is extents based, it will call ext4_ext_map_blocks(),
530 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
533 * On success, it returns the number of blocks being mapped or allocate.
534 * if create==0 and the blocks are pre-allocated and uninitialized block,
535 * the result buffer head is unmapped. If the create ==1, it will make sure
536 * the buffer head is mapped.
538 * It returns 0 if plain look up failed (blocks have not been allocated), in
539 * that case, buffer head is unmapped
541 * It returns the error in case of allocation failure.
543 int ext4_map_blocks(handle_t *handle, struct inode *inode,
544 struct ext4_map_blocks *map, int flags)
549 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
550 "logical block %lu\n", inode->i_ino, flags, map->m_len,
551 (unsigned long) map->m_lblk);
553 * Try to see if we can get the block without requesting a new
556 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
557 down_read((&EXT4_I(inode)->i_data_sem));
558 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
559 retval = ext4_ext_map_blocks(handle, inode, map, flags &
560 EXT4_GET_BLOCKS_KEEP_SIZE);
562 retval = ext4_ind_map_blocks(handle, inode, map, flags &
563 EXT4_GET_BLOCKS_KEEP_SIZE);
565 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
566 up_read((&EXT4_I(inode)->i_data_sem));
568 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
569 int ret = check_block_validity(inode, map);
574 /* If it is only a block(s) look up */
575 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
579 * Returns if the blocks have already allocated
581 * Note that if blocks have been preallocated
582 * ext4_ext_get_block() returns the create = 0
583 * with buffer head unmapped.
585 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
589 * When we call get_blocks without the create flag, the
590 * BH_Unwritten flag could have gotten set if the blocks
591 * requested were part of a uninitialized extent. We need to
592 * clear this flag now that we are committed to convert all or
593 * part of the uninitialized extent to be an initialized
594 * extent. This is because we need to avoid the combination
595 * of BH_Unwritten and BH_Mapped flags being simultaneously
596 * set on the buffer_head.
598 map->m_flags &= ~EXT4_MAP_UNWRITTEN;
601 * New blocks allocate and/or writing to uninitialized extent
602 * will possibly result in updating i_data, so we take
603 * the write lock of i_data_sem, and call get_blocks()
604 * with create == 1 flag.
606 down_write((&EXT4_I(inode)->i_data_sem));
609 * if the caller is from delayed allocation writeout path
610 * we have already reserved fs blocks for allocation
611 * let the underlying get_block() function know to
612 * avoid double accounting
614 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
615 ext4_set_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
617 * We need to check for EXT4 here because migrate
618 * could have changed the inode type in between
620 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
621 retval = ext4_ext_map_blocks(handle, inode, map, flags);
623 retval = ext4_ind_map_blocks(handle, inode, map, flags);
625 if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
627 * We allocated new blocks which will result in
628 * i_data's format changing. Force the migrate
629 * to fail by clearing migrate flags
631 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
635 * Update reserved blocks/metadata blocks after successful
636 * block allocation which had been deferred till now. We don't
637 * support fallocate for non extent files. So we can update
638 * reserve space here.
641 (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
642 ext4_da_update_reserve_space(inode, retval, 1);
644 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
645 ext4_clear_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
647 /* If we have successfully mapped the delayed allocated blocks,
648 * set the BH_Da_Mapped bit on them. Its important to do this
649 * under the protection of i_data_sem.
651 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
652 set_buffers_da_mapped(inode, map);
655 up_write((&EXT4_I(inode)->i_data_sem));
656 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
657 int ret = check_block_validity(inode, map);
664 /* Maximum number of blocks we map for direct IO at once. */
665 #define DIO_MAX_BLOCKS 4096
667 static int _ext4_get_block(struct inode *inode, sector_t iblock,
668 struct buffer_head *bh, int flags)
670 handle_t *handle = ext4_journal_current_handle();
671 struct ext4_map_blocks map;
672 int ret = 0, started = 0;
676 map.m_len = bh->b_size >> inode->i_blkbits;
678 if (flags && !handle) {
679 /* Direct IO write... */
680 if (map.m_len > DIO_MAX_BLOCKS)
681 map.m_len = DIO_MAX_BLOCKS;
682 dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
683 handle = ext4_journal_start(inode, dio_credits);
684 if (IS_ERR(handle)) {
685 ret = PTR_ERR(handle);
691 ret = ext4_map_blocks(handle, inode, &map, flags);
693 map_bh(bh, inode->i_sb, map.m_pblk);
694 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
695 bh->b_size = inode->i_sb->s_blocksize * map.m_len;
699 ext4_journal_stop(handle);
703 int ext4_get_block(struct inode *inode, sector_t iblock,
704 struct buffer_head *bh, int create)
706 return _ext4_get_block(inode, iblock, bh,
707 create ? EXT4_GET_BLOCKS_CREATE : 0);
711 * `handle' can be NULL if create is zero
713 struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
714 ext4_lblk_t block, int create, int *errp)
716 struct ext4_map_blocks map;
717 struct buffer_head *bh;
720 J_ASSERT(handle != NULL || create == 0);
724 err = ext4_map_blocks(handle, inode, &map,
725 create ? EXT4_GET_BLOCKS_CREATE : 0);
733 bh = sb_getblk(inode->i_sb, map.m_pblk);
738 if (map.m_flags & EXT4_MAP_NEW) {
739 J_ASSERT(create != 0);
740 J_ASSERT(handle != NULL);
743 * Now that we do not always journal data, we should
744 * keep in mind whether this should always journal the
745 * new buffer as metadata. For now, regular file
746 * writes use ext4_get_block instead, so it's not a
750 BUFFER_TRACE(bh, "call get_create_access");
751 fatal = ext4_journal_get_create_access(handle, bh);
752 if (!fatal && !buffer_uptodate(bh)) {
753 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
754 set_buffer_uptodate(bh);
757 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
758 err = ext4_handle_dirty_metadata(handle, inode, bh);
762 BUFFER_TRACE(bh, "not a new buffer");
772 struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
773 ext4_lblk_t block, int create, int *err)
775 struct buffer_head *bh;
777 bh = ext4_getblk(handle, inode, block, create, err);
780 if (buffer_uptodate(bh))
782 ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh);
784 if (buffer_uptodate(bh))
791 static int walk_page_buffers(handle_t *handle,
792 struct buffer_head *head,
796 int (*fn)(handle_t *handle,
797 struct buffer_head *bh))
799 struct buffer_head *bh;
800 unsigned block_start, block_end;
801 unsigned blocksize = head->b_size;
803 struct buffer_head *next;
805 for (bh = head, block_start = 0;
806 ret == 0 && (bh != head || !block_start);
807 block_start = block_end, bh = next) {
808 next = bh->b_this_page;
809 block_end = block_start + blocksize;
810 if (block_end <= from || block_start >= to) {
811 if (partial && !buffer_uptodate(bh))
815 err = (*fn)(handle, bh);
823 * To preserve ordering, it is essential that the hole instantiation and
824 * the data write be encapsulated in a single transaction. We cannot
825 * close off a transaction and start a new one between the ext4_get_block()
826 * and the commit_write(). So doing the jbd2_journal_start at the start of
827 * prepare_write() is the right place.
829 * Also, this function can nest inside ext4_writepage() ->
830 * block_write_full_page(). In that case, we *know* that ext4_writepage()
831 * has generated enough buffer credits to do the whole page. So we won't
832 * block on the journal in that case, which is good, because the caller may
835 * By accident, ext4 can be reentered when a transaction is open via
836 * quota file writes. If we were to commit the transaction while thus
837 * reentered, there can be a deadlock - we would be holding a quota
838 * lock, and the commit would never complete if another thread had a
839 * transaction open and was blocking on the quota lock - a ranking
842 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
843 * will _not_ run commit under these circumstances because handle->h_ref
844 * is elevated. We'll still have enough credits for the tiny quotafile
847 static int do_journal_get_write_access(handle_t *handle,
848 struct buffer_head *bh)
850 int dirty = buffer_dirty(bh);
853 if (!buffer_mapped(bh) || buffer_freed(bh))
856 * __block_write_begin() could have dirtied some buffers. Clean
857 * the dirty bit as jbd2_journal_get_write_access() could complain
858 * otherwise about fs integrity issues. Setting of the dirty bit
859 * by __block_write_begin() isn't a real problem here as we clear
860 * the bit before releasing a page lock and thus writeback cannot
861 * ever write the buffer.
864 clear_buffer_dirty(bh);
865 ret = ext4_journal_get_write_access(handle, bh);
867 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
871 static int ext4_get_block_write(struct inode *inode, sector_t iblock,
872 struct buffer_head *bh_result, int create);
873 static int ext4_write_begin(struct file *file, struct address_space *mapping,
874 loff_t pos, unsigned len, unsigned flags,
875 struct page **pagep, void **fsdata)
877 struct inode *inode = mapping->host;
878 int ret, needed_blocks;
885 trace_ext4_write_begin(inode, pos, len, flags);
887 * Reserve one block more for addition to orphan list in case
888 * we allocate blocks but write fails for some reason
890 needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
891 index = pos >> PAGE_CACHE_SHIFT;
892 from = pos & (PAGE_CACHE_SIZE - 1);
896 handle = ext4_journal_start(inode, needed_blocks);
897 if (IS_ERR(handle)) {
898 ret = PTR_ERR(handle);
902 /* We cannot recurse into the filesystem as the transaction is already
904 flags |= AOP_FLAG_NOFS;
906 page = grab_cache_page_write_begin(mapping, index, flags);
908 ext4_journal_stop(handle);
914 if (ext4_should_dioread_nolock(inode))
915 ret = __block_write_begin(page, pos, len, ext4_get_block_write);
917 ret = __block_write_begin(page, pos, len, ext4_get_block);
919 if (!ret && ext4_should_journal_data(inode)) {
920 ret = walk_page_buffers(handle, page_buffers(page),
921 from, to, NULL, do_journal_get_write_access);
926 page_cache_release(page);
928 * __block_write_begin may have instantiated a few blocks
929 * outside i_size. Trim these off again. Don't need
930 * i_size_read because we hold i_mutex.
932 * Add inode to orphan list in case we crash before
935 if (pos + len > inode->i_size && ext4_can_truncate(inode))
936 ext4_orphan_add(handle, inode);
938 ext4_journal_stop(handle);
939 if (pos + len > inode->i_size) {
940 ext4_truncate_failed_write(inode);
942 * If truncate failed early the inode might
943 * still be on the orphan list; we need to
944 * make sure the inode is removed from the
945 * orphan list in that case.
948 ext4_orphan_del(NULL, inode);
952 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
958 /* For write_end() in data=journal mode */
959 static int write_end_fn(handle_t *handle, struct buffer_head *bh)
961 if (!buffer_mapped(bh) || buffer_freed(bh))
963 set_buffer_uptodate(bh);
964 return ext4_handle_dirty_metadata(handle, NULL, bh);
967 static int ext4_generic_write_end(struct file *file,
968 struct address_space *mapping,
969 loff_t pos, unsigned len, unsigned copied,
970 struct page *page, void *fsdata)
972 int i_size_changed = 0;
973 struct inode *inode = mapping->host;
974 handle_t *handle = ext4_journal_current_handle();
976 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
979 * No need to use i_size_read() here, the i_size
980 * cannot change under us because we hold i_mutex.
982 * But it's important to update i_size while still holding page lock:
983 * page writeout could otherwise come in and zero beyond i_size.
985 if (pos + copied > inode->i_size) {
986 i_size_write(inode, pos + copied);
990 if (pos + copied > EXT4_I(inode)->i_disksize) {
991 /* We need to mark inode dirty even if
992 * new_i_size is less that inode->i_size
993 * bu greater than i_disksize.(hint delalloc)
995 ext4_update_i_disksize(inode, (pos + copied));
999 page_cache_release(page);
1002 * Don't mark the inode dirty under page lock. First, it unnecessarily
1003 * makes the holding time of page lock longer. Second, it forces lock
1004 * ordering of page lock and transaction start for journaling
1008 ext4_mark_inode_dirty(handle, inode);
1014 * We need to pick up the new inode size which generic_commit_write gave us
1015 * `file' can be NULL - eg, when called from page_symlink().
1017 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1018 * buffers are managed internally.
1020 static int ext4_ordered_write_end(struct file *file,
1021 struct address_space *mapping,
1022 loff_t pos, unsigned len, unsigned copied,
1023 struct page *page, void *fsdata)
1025 handle_t *handle = ext4_journal_current_handle();
1026 struct inode *inode = mapping->host;
1029 trace_ext4_ordered_write_end(inode, pos, len, copied);
1030 ret = ext4_jbd2_file_inode(handle, inode);
1033 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
1036 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1037 /* if we have allocated more blocks and copied
1038 * less. We will have blocks allocated outside
1039 * inode->i_size. So truncate them
1041 ext4_orphan_add(handle, inode);
1046 page_cache_release(page);
1049 ret2 = ext4_journal_stop(handle);
1053 if (pos + len > inode->i_size) {
1054 ext4_truncate_failed_write(inode);
1056 * If truncate failed early the inode might still be
1057 * on the orphan list; we need to make sure the inode
1058 * is removed from the orphan list in that case.
1061 ext4_orphan_del(NULL, inode);
1065 return ret ? ret : copied;
1068 static int ext4_writeback_write_end(struct file *file,
1069 struct address_space *mapping,
1070 loff_t pos, unsigned len, unsigned copied,
1071 struct page *page, void *fsdata)
1073 handle_t *handle = ext4_journal_current_handle();
1074 struct inode *inode = mapping->host;
1077 trace_ext4_writeback_write_end(inode, pos, len, copied);
1078 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
1081 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1082 /* if we have allocated more blocks and copied
1083 * less. We will have blocks allocated outside
1084 * inode->i_size. So truncate them
1086 ext4_orphan_add(handle, inode);
1091 ret2 = ext4_journal_stop(handle);
1095 if (pos + len > inode->i_size) {
1096 ext4_truncate_failed_write(inode);
1098 * If truncate failed early the inode might still be
1099 * on the orphan list; we need to make sure the inode
1100 * is removed from the orphan list in that case.
1103 ext4_orphan_del(NULL, inode);
1106 return ret ? ret : copied;
1109 static int ext4_journalled_write_end(struct file *file,
1110 struct address_space *mapping,
1111 loff_t pos, unsigned len, unsigned copied,
1112 struct page *page, void *fsdata)
1114 handle_t *handle = ext4_journal_current_handle();
1115 struct inode *inode = mapping->host;
1121 trace_ext4_journalled_write_end(inode, pos, len, copied);
1122 from = pos & (PAGE_CACHE_SIZE - 1);
1125 BUG_ON(!ext4_handle_valid(handle));
1128 if (!PageUptodate(page))
1130 page_zero_new_buffers(page, from+copied, to);
1133 ret = walk_page_buffers(handle, page_buffers(page), from,
1134 to, &partial, write_end_fn);
1136 SetPageUptodate(page);
1137 new_i_size = pos + copied;
1138 if (new_i_size > inode->i_size)
1139 i_size_write(inode, pos+copied);
1140 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1141 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1142 if (new_i_size > EXT4_I(inode)->i_disksize) {
1143 ext4_update_i_disksize(inode, new_i_size);
1144 ret2 = ext4_mark_inode_dirty(handle, inode);
1150 page_cache_release(page);
1151 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1152 /* if we have allocated more blocks and copied
1153 * less. We will have blocks allocated outside
1154 * inode->i_size. So truncate them
1156 ext4_orphan_add(handle, inode);
1158 ret2 = ext4_journal_stop(handle);
1161 if (pos + len > inode->i_size) {
1162 ext4_truncate_failed_write(inode);
1164 * If truncate failed early the inode might still be
1165 * on the orphan list; we need to make sure the inode
1166 * is removed from the orphan list in that case.
1169 ext4_orphan_del(NULL, inode);
1172 return ret ? ret : copied;
1176 * Reserve a single cluster located at lblock
1178 static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock)
1181 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1182 struct ext4_inode_info *ei = EXT4_I(inode);
1183 unsigned int md_needed;
1185 ext4_lblk_t save_last_lblock;
1189 * We will charge metadata quota at writeout time; this saves
1190 * us from metadata over-estimation, though we may go over by
1191 * a small amount in the end. Here we just reserve for data.
1193 ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1));
1198 * recalculate the amount of metadata blocks to reserve
1199 * in order to allocate nrblocks
1200 * worse case is one extent per block
1203 spin_lock(&ei->i_block_reservation_lock);
1205 * ext4_calc_metadata_amount() has side effects, which we have
1206 * to be prepared undo if we fail to claim space.
1208 save_len = ei->i_da_metadata_calc_len;
1209 save_last_lblock = ei->i_da_metadata_calc_last_lblock;
1210 md_needed = EXT4_NUM_B2C(sbi,
1211 ext4_calc_metadata_amount(inode, lblock));
1212 trace_ext4_da_reserve_space(inode, md_needed);
1215 * We do still charge estimated metadata to the sb though;
1216 * we cannot afford to run out of free blocks.
1218 if (ext4_claim_free_clusters(sbi, md_needed + 1, 0)) {
1219 ei->i_da_metadata_calc_len = save_len;
1220 ei->i_da_metadata_calc_last_lblock = save_last_lblock;
1221 spin_unlock(&ei->i_block_reservation_lock);
1222 if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
1226 dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
1229 ei->i_reserved_data_blocks++;
1230 ei->i_reserved_meta_blocks += md_needed;
1231 spin_unlock(&ei->i_block_reservation_lock);
1233 return 0; /* success */
1236 static void ext4_da_release_space(struct inode *inode, int to_free)
1238 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1239 struct ext4_inode_info *ei = EXT4_I(inode);
1242 return; /* Nothing to release, exit */
1244 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1246 trace_ext4_da_release_space(inode, to_free);
1247 if (unlikely(to_free > ei->i_reserved_data_blocks)) {
1249 * if there aren't enough reserved blocks, then the
1250 * counter is messed up somewhere. Since this
1251 * function is called from invalidate page, it's
1252 * harmless to return without any action.
1254 ext4_msg(inode->i_sb, KERN_NOTICE, "ext4_da_release_space: "
1255 "ino %lu, to_free %d with only %d reserved "
1256 "data blocks", inode->i_ino, to_free,
1257 ei->i_reserved_data_blocks);
1259 to_free = ei->i_reserved_data_blocks;
1261 ei->i_reserved_data_blocks -= to_free;
1263 if (ei->i_reserved_data_blocks == 0) {
1265 * We can release all of the reserved metadata blocks
1266 * only when we have written all of the delayed
1267 * allocation blocks.
1268 * Note that in case of bigalloc, i_reserved_meta_blocks,
1269 * i_reserved_data_blocks, etc. refer to number of clusters.
1271 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
1272 ei->i_reserved_meta_blocks);
1273 ei->i_reserved_meta_blocks = 0;
1274 ei->i_da_metadata_calc_len = 0;
1277 /* update fs dirty data blocks counter */
1278 percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free);
1280 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1282 dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free));
1285 static void ext4_da_page_release_reservation(struct page *page,
1286 unsigned long offset)
1289 struct buffer_head *head, *bh;
1290 unsigned int curr_off = 0;
1291 struct inode *inode = page->mapping->host;
1292 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1295 head = page_buffers(page);
1298 unsigned int next_off = curr_off + bh->b_size;
1300 if ((offset <= curr_off) && (buffer_delay(bh))) {
1302 clear_buffer_delay(bh);
1303 clear_buffer_da_mapped(bh);
1305 curr_off = next_off;
1306 } while ((bh = bh->b_this_page) != head);
1308 /* If we have released all the blocks belonging to a cluster, then we
1309 * need to release the reserved space for that cluster. */
1310 num_clusters = EXT4_NUM_B2C(sbi, to_release);
1311 while (num_clusters > 0) {
1313 lblk = (page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits)) +
1314 ((num_clusters - 1) << sbi->s_cluster_bits);
1315 if (sbi->s_cluster_ratio == 1 ||
1316 !ext4_find_delalloc_cluster(inode, lblk, 1))
1317 ext4_da_release_space(inode, 1);
1324 * Delayed allocation stuff
1328 * mpage_da_submit_io - walks through extent of pages and try to write
1329 * them with writepage() call back
1331 * @mpd->inode: inode
1332 * @mpd->first_page: first page of the extent
1333 * @mpd->next_page: page after the last page of the extent
1335 * By the time mpage_da_submit_io() is called we expect all blocks
1336 * to be allocated. this may be wrong if allocation failed.
1338 * As pages are already locked by write_cache_pages(), we can't use it
1340 static int mpage_da_submit_io(struct mpage_da_data *mpd,
1341 struct ext4_map_blocks *map)
1343 struct pagevec pvec;
1344 unsigned long index, end;
1345 int ret = 0, err, nr_pages, i;
1346 struct inode *inode = mpd->inode;
1347 struct address_space *mapping = inode->i_mapping;
1348 loff_t size = i_size_read(inode);
1349 unsigned int len, block_start;
1350 struct buffer_head *bh, *page_bufs = NULL;
1351 int journal_data = ext4_should_journal_data(inode);
1352 sector_t pblock = 0, cur_logical = 0;
1353 struct ext4_io_submit io_submit;
1355 BUG_ON(mpd->next_page <= mpd->first_page);
1356 memset(&io_submit, 0, sizeof(io_submit));
1358 * We need to start from the first_page to the next_page - 1
1359 * to make sure we also write the mapped dirty buffer_heads.
1360 * If we look at mpd->b_blocknr we would only be looking
1361 * at the currently mapped buffer_heads.
1363 index = mpd->first_page;
1364 end = mpd->next_page - 1;
1366 pagevec_init(&pvec, 0);
1367 while (index <= end) {
1368 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
1371 for (i = 0; i < nr_pages; i++) {
1372 int commit_write = 0, skip_page = 0;
1373 struct page *page = pvec.pages[i];
1375 index = page->index;
1379 if (index == size >> PAGE_CACHE_SHIFT)
1380 len = size & ~PAGE_CACHE_MASK;
1382 len = PAGE_CACHE_SIZE;
1384 cur_logical = index << (PAGE_CACHE_SHIFT -
1386 pblock = map->m_pblk + (cur_logical -
1391 BUG_ON(!PageLocked(page));
1392 BUG_ON(PageWriteback(page));
1395 * If the page does not have buffers (for
1396 * whatever reason), try to create them using
1397 * __block_write_begin. If this fails,
1398 * skip the page and move on.
1400 if (!page_has_buffers(page)) {
1401 if (__block_write_begin(page, 0, len,
1402 noalloc_get_block_write)) {
1410 bh = page_bufs = page_buffers(page);
1415 if (map && (cur_logical >= map->m_lblk) &&
1416 (cur_logical <= (map->m_lblk +
1417 (map->m_len - 1)))) {
1418 if (buffer_delay(bh)) {
1419 clear_buffer_delay(bh);
1420 bh->b_blocknr = pblock;
1422 if (buffer_da_mapped(bh))
1423 clear_buffer_da_mapped(bh);
1424 if (buffer_unwritten(bh) ||
1426 BUG_ON(bh->b_blocknr != pblock);
1427 if (map->m_flags & EXT4_MAP_UNINIT)
1428 set_buffer_uninit(bh);
1429 clear_buffer_unwritten(bh);
1433 * skip page if block allocation undone and
1436 if (ext4_bh_delay_or_unwritten(NULL, bh))
1438 bh = bh->b_this_page;
1439 block_start += bh->b_size;
1442 } while (bh != page_bufs);
1448 /* mark the buffer_heads as dirty & uptodate */
1449 block_commit_write(page, 0, len);
1451 clear_page_dirty_for_io(page);
1453 * Delalloc doesn't support data journalling,
1454 * but eventually maybe we'll lift this
1457 if (unlikely(journal_data && PageChecked(page)))
1458 err = __ext4_journalled_writepage(page, len);
1459 else if (test_opt(inode->i_sb, MBLK_IO_SUBMIT))
1460 err = ext4_bio_write_page(&io_submit, page,
1462 else if (buffer_uninit(page_bufs)) {
1463 ext4_set_bh_endio(page_bufs, inode);
1464 err = block_write_full_page_endio(page,
1465 noalloc_get_block_write,
1466 mpd->wbc, ext4_end_io_buffer_write);
1468 err = block_write_full_page(page,
1469 noalloc_get_block_write, mpd->wbc);
1472 mpd->pages_written++;
1474 * In error case, we have to continue because
1475 * remaining pages are still locked
1480 pagevec_release(&pvec);
1482 ext4_io_submit(&io_submit);
1486 static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd)
1490 struct pagevec pvec;
1491 struct inode *inode = mpd->inode;
1492 struct address_space *mapping = inode->i_mapping;
1494 index = mpd->first_page;
1495 end = mpd->next_page - 1;
1496 while (index <= end) {
1497 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
1500 for (i = 0; i < nr_pages; i++) {
1501 struct page *page = pvec.pages[i];
1502 if (page->index > end)
1504 BUG_ON(!PageLocked(page));
1505 BUG_ON(PageWriteback(page));
1506 block_invalidatepage(page, 0);
1507 ClearPageUptodate(page);
1510 index = pvec.pages[nr_pages - 1]->index + 1;
1511 pagevec_release(&pvec);
1516 static void ext4_print_free_blocks(struct inode *inode)
1518 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1519 struct super_block *sb = inode->i_sb;
1521 ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld",
1522 EXT4_C2B(EXT4_SB(inode->i_sb),
1523 ext4_count_free_clusters(inode->i_sb)));
1524 ext4_msg(sb, KERN_CRIT, "Free/Dirty block details");
1525 ext4_msg(sb, KERN_CRIT, "free_blocks=%lld",
1526 (long long) EXT4_C2B(EXT4_SB(inode->i_sb),
1527 percpu_counter_sum(&sbi->s_freeclusters_counter)));
1528 ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld",
1529 (long long) EXT4_C2B(EXT4_SB(inode->i_sb),
1530 percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
1531 ext4_msg(sb, KERN_CRIT, "Block reservation details");
1532 ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u",
1533 EXT4_I(inode)->i_reserved_data_blocks);
1534 ext4_msg(sb, KERN_CRIT, "i_reserved_meta_blocks=%u",
1535 EXT4_I(inode)->i_reserved_meta_blocks);
1540 * mpage_da_map_and_submit - go through given space, map them
1541 * if necessary, and then submit them for I/O
1543 * @mpd - bh describing space
1545 * The function skips space we know is already mapped to disk blocks.
1548 static void mpage_da_map_and_submit(struct mpage_da_data *mpd)
1550 int err, blks, get_blocks_flags;
1551 struct ext4_map_blocks map, *mapp = NULL;
1552 sector_t next = mpd->b_blocknr;
1553 unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits;
1554 loff_t disksize = EXT4_I(mpd->inode)->i_disksize;
1555 handle_t *handle = NULL;
1558 * If the blocks are mapped already, or we couldn't accumulate
1559 * any blocks, then proceed immediately to the submission stage.
1561 if ((mpd->b_size == 0) ||
1562 ((mpd->b_state & (1 << BH_Mapped)) &&
1563 !(mpd->b_state & (1 << BH_Delay)) &&
1564 !(mpd->b_state & (1 << BH_Unwritten))))
1567 handle = ext4_journal_current_handle();
1571 * Call ext4_map_blocks() to allocate any delayed allocation
1572 * blocks, or to convert an uninitialized extent to be
1573 * initialized (in the case where we have written into
1574 * one or more preallocated blocks).
1576 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
1577 * indicate that we are on the delayed allocation path. This
1578 * affects functions in many different parts of the allocation
1579 * call path. This flag exists primarily because we don't
1580 * want to change *many* call functions, so ext4_map_blocks()
1581 * will set the EXT4_STATE_DELALLOC_RESERVED flag once the
1582 * inode's allocation semaphore is taken.
1584 * If the blocks in questions were delalloc blocks, set
1585 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
1586 * variables are updated after the blocks have been allocated.
1589 map.m_len = max_blocks;
1590 get_blocks_flags = EXT4_GET_BLOCKS_CREATE;
1591 if (ext4_should_dioread_nolock(mpd->inode))
1592 get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
1593 if (mpd->b_state & (1 << BH_Delay))
1594 get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
1596 blks = ext4_map_blocks(handle, mpd->inode, &map, get_blocks_flags);
1598 struct super_block *sb = mpd->inode->i_sb;
1602 * If get block returns EAGAIN or ENOSPC and there
1603 * appears to be free blocks we will just let
1604 * mpage_da_submit_io() unlock all of the pages.
1609 if (err == -ENOSPC && ext4_count_free_clusters(sb)) {
1615 * get block failure will cause us to loop in
1616 * writepages, because a_ops->writepage won't be able
1617 * to make progress. The page will be redirtied by
1618 * writepage and writepages will again try to write
1621 if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) {
1622 ext4_msg(sb, KERN_CRIT,
1623 "delayed block allocation failed for inode %lu "
1624 "at logical offset %llu with max blocks %zd "
1625 "with error %d", mpd->inode->i_ino,
1626 (unsigned long long) next,
1627 mpd->b_size >> mpd->inode->i_blkbits, err);
1628 ext4_msg(sb, KERN_CRIT,
1629 "This should not happen!! Data will be lost\n");
1631 ext4_print_free_blocks(mpd->inode);
1633 /* invalidate all the pages */
1634 ext4_da_block_invalidatepages(mpd);
1636 /* Mark this page range as having been completed */
1643 if (map.m_flags & EXT4_MAP_NEW) {
1644 struct block_device *bdev = mpd->inode->i_sb->s_bdev;
1647 for (i = 0; i < map.m_len; i++)
1648 unmap_underlying_metadata(bdev, map.m_pblk + i);
1650 if (ext4_should_order_data(mpd->inode)) {
1651 err = ext4_jbd2_file_inode(handle, mpd->inode);
1653 /* Only if the journal is aborted */
1661 * Update on-disk size along with block allocation.
1663 disksize = ((loff_t) next + blks) << mpd->inode->i_blkbits;
1664 if (disksize > i_size_read(mpd->inode))
1665 disksize = i_size_read(mpd->inode);
1666 if (disksize > EXT4_I(mpd->inode)->i_disksize) {
1667 ext4_update_i_disksize(mpd->inode, disksize);
1668 err = ext4_mark_inode_dirty(handle, mpd->inode);
1670 ext4_error(mpd->inode->i_sb,
1671 "Failed to mark inode %lu dirty",
1676 mpage_da_submit_io(mpd, mapp);
1680 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
1681 (1 << BH_Delay) | (1 << BH_Unwritten))
1684 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
1686 * @mpd->lbh - extent of blocks
1687 * @logical - logical number of the block in the file
1688 * @bh - bh of the block (used to access block's state)
1690 * the function is used to collect contig. blocks in same state
1692 static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
1693 sector_t logical, size_t b_size,
1694 unsigned long b_state)
1697 int nrblocks = mpd->b_size >> mpd->inode->i_blkbits;
1700 * XXX Don't go larger than mballoc is willing to allocate
1701 * This is a stopgap solution. We eventually need to fold
1702 * mpage_da_submit_io() into this function and then call
1703 * ext4_map_blocks() multiple times in a loop
1705 if (nrblocks >= 8*1024*1024/mpd->inode->i_sb->s_blocksize)
1708 /* check if thereserved journal credits might overflow */
1709 if (!(ext4_test_inode_flag(mpd->inode, EXT4_INODE_EXTENTS))) {
1710 if (nrblocks >= EXT4_MAX_TRANS_DATA) {
1712 * With non-extent format we are limited by the journal
1713 * credit available. Total credit needed to insert
1714 * nrblocks contiguous blocks is dependent on the
1715 * nrblocks. So limit nrblocks.
1718 } else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) >
1719 EXT4_MAX_TRANS_DATA) {
1721 * Adding the new buffer_head would make it cross the
1722 * allowed limit for which we have journal credit
1723 * reserved. So limit the new bh->b_size
1725 b_size = (EXT4_MAX_TRANS_DATA - nrblocks) <<
1726 mpd->inode->i_blkbits;
1727 /* we will do mpage_da_submit_io in the next loop */
1731 * First block in the extent
1733 if (mpd->b_size == 0) {
1734 mpd->b_blocknr = logical;
1735 mpd->b_size = b_size;
1736 mpd->b_state = b_state & BH_FLAGS;
1740 next = mpd->b_blocknr + nrblocks;
1742 * Can we merge the block to our big extent?
1744 if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
1745 mpd->b_size += b_size;
1751 * We couldn't merge the block to our extent, so we
1752 * need to flush current extent and start new one
1754 mpage_da_map_and_submit(mpd);
1758 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
1760 return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
1764 * This function is grabs code from the very beginning of
1765 * ext4_map_blocks, but assumes that the caller is from delayed write
1766 * time. This function looks up the requested blocks and sets the
1767 * buffer delay bit under the protection of i_data_sem.
1769 static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
1770 struct ext4_map_blocks *map,
1771 struct buffer_head *bh)
1774 sector_t invalid_block = ~((sector_t) 0xffff);
1776 if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
1780 ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u,"
1781 "logical block %lu\n", inode->i_ino, map->m_len,
1782 (unsigned long) map->m_lblk);
1784 * Try to see if we can get the block without requesting a new
1785 * file system block.
1787 down_read((&EXT4_I(inode)->i_data_sem));
1788 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
1789 retval = ext4_ext_map_blocks(NULL, inode, map, 0);
1791 retval = ext4_ind_map_blocks(NULL, inode, map, 0);
1795 * XXX: __block_prepare_write() unmaps passed block,
1798 /* If the block was allocated from previously allocated cluster,
1799 * then we dont need to reserve it again. */
1800 if (!(map->m_flags & EXT4_MAP_FROM_CLUSTER)) {
1801 retval = ext4_da_reserve_space(inode, iblock);
1803 /* not enough space to reserve */
1807 /* Clear EXT4_MAP_FROM_CLUSTER flag since its purpose is served
1808 * and it should not appear on the bh->b_state.
1810 map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
1812 map_bh(bh, inode->i_sb, invalid_block);
1814 set_buffer_delay(bh);
1818 up_read((&EXT4_I(inode)->i_data_sem));
1824 * This is a special get_blocks_t callback which is used by
1825 * ext4_da_write_begin(). It will either return mapped block or
1826 * reserve space for a single block.
1828 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
1829 * We also have b_blocknr = -1 and b_bdev initialized properly
1831 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
1832 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
1833 * initialized properly.
1835 static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
1836 struct buffer_head *bh, int create)
1838 struct ext4_map_blocks map;
1841 BUG_ON(create == 0);
1842 BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
1844 map.m_lblk = iblock;
1848 * first, we need to know whether the block is allocated already
1849 * preallocated blocks are unmapped but should treated
1850 * the same as allocated blocks.
1852 ret = ext4_da_map_blocks(inode, iblock, &map, bh);
1856 map_bh(bh, inode->i_sb, map.m_pblk);
1857 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
1859 if (buffer_unwritten(bh)) {
1860 /* A delayed write to unwritten bh should be marked
1861 * new and mapped. Mapped ensures that we don't do
1862 * get_block multiple times when we write to the same
1863 * offset and new ensures that we do proper zero out
1864 * for partial write.
1867 set_buffer_mapped(bh);
1873 * This function is used as a standard get_block_t calback function
1874 * when there is no desire to allocate any blocks. It is used as a
1875 * callback function for block_write_begin() and block_write_full_page().
1876 * These functions should only try to map a single block at a time.
1878 * Since this function doesn't do block allocations even if the caller
1879 * requests it by passing in create=1, it is critically important that
1880 * any caller checks to make sure that any buffer heads are returned
1881 * by this function are either all already mapped or marked for
1882 * delayed allocation before calling block_write_full_page(). Otherwise,
1883 * b_blocknr could be left unitialized, and the page write functions will
1884 * be taken by surprise.
1886 static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
1887 struct buffer_head *bh_result, int create)
1889 BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
1890 return _ext4_get_block(inode, iblock, bh_result, 0);
1893 static int bget_one(handle_t *handle, struct buffer_head *bh)
1899 static int bput_one(handle_t *handle, struct buffer_head *bh)
1905 static int __ext4_journalled_writepage(struct page *page,
1908 struct address_space *mapping = page->mapping;
1909 struct inode *inode = mapping->host;
1910 struct buffer_head *page_bufs;
1911 handle_t *handle = NULL;
1915 ClearPageChecked(page);
1916 page_bufs = page_buffers(page);
1918 walk_page_buffers(handle, page_bufs, 0, len, NULL, bget_one);
1919 /* As soon as we unlock the page, it can go away, but we have
1920 * references to buffers so we are safe */
1923 handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
1924 if (IS_ERR(handle)) {
1925 ret = PTR_ERR(handle);
1929 BUG_ON(!ext4_handle_valid(handle));
1931 ret = walk_page_buffers(handle, page_bufs, 0, len, NULL,
1932 do_journal_get_write_access);
1934 err = walk_page_buffers(handle, page_bufs, 0, len, NULL,
1938 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1939 err = ext4_journal_stop(handle);
1943 walk_page_buffers(handle, page_bufs, 0, len, NULL, bput_one);
1944 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1949 static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode);
1950 static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
1953 * Note that we don't need to start a transaction unless we're journaling data
1954 * because we should have holes filled from ext4_page_mkwrite(). We even don't
1955 * need to file the inode to the transaction's list in ordered mode because if
1956 * we are writing back data added by write(), the inode is already there and if
1957 * we are writing back data modified via mmap(), no one guarantees in which
1958 * transaction the data will hit the disk. In case we are journaling data, we
1959 * cannot start transaction directly because transaction start ranks above page
1960 * lock so we have to do some magic.
1962 * This function can get called via...
1963 * - ext4_da_writepages after taking page lock (have journal handle)
1964 * - journal_submit_inode_data_buffers (no journal handle)
1965 * - shrink_page_list via pdflush (no journal handle)
1966 * - grab_page_cache when doing write_begin (have journal handle)
1968 * We don't do any block allocation in this function. If we have page with
1969 * multiple blocks we need to write those buffer_heads that are mapped. This
1970 * is important for mmaped based write. So if we do with blocksize 1K
1971 * truncate(f, 1024);
1972 * a = mmap(f, 0, 4096);
1974 * truncate(f, 4096);
1975 * we have in the page first buffer_head mapped via page_mkwrite call back
1976 * but other buffer_heads would be unmapped but dirty (dirty done via the
1977 * do_wp_page). So writepage should write the first block. If we modify
1978 * the mmap area beyond 1024 we will again get a page_fault and the
1979 * page_mkwrite callback will do the block allocation and mark the
1980 * buffer_heads mapped.
1982 * We redirty the page if we have any buffer_heads that is either delay or
1983 * unwritten in the page.
1985 * We can get recursively called as show below.
1987 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1990 * But since we don't do any block allocation we should not deadlock.
1991 * Page also have the dirty flag cleared so we don't get recurive page_lock.
1993 static int ext4_writepage(struct page *page,
1994 struct writeback_control *wbc)
1996 int ret = 0, commit_write = 0;
1999 struct buffer_head *page_bufs = NULL;
2000 struct inode *inode = page->mapping->host;
2002 trace_ext4_writepage(page);
2003 size = i_size_read(inode);
2004 if (page->index == size >> PAGE_CACHE_SHIFT)
2005 len = size & ~PAGE_CACHE_MASK;
2007 len = PAGE_CACHE_SIZE;
2010 * If the page does not have buffers (for whatever reason),
2011 * try to create them using __block_write_begin. If this
2012 * fails, redirty the page and move on.
2014 if (!page_has_buffers(page)) {
2015 if (__block_write_begin(page, 0, len,
2016 noalloc_get_block_write)) {
2018 redirty_page_for_writepage(wbc, page);
2024 page_bufs = page_buffers(page);
2025 if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
2026 ext4_bh_delay_or_unwritten)) {
2028 * We don't want to do block allocation, so redirty
2029 * the page and return. We may reach here when we do
2030 * a journal commit via journal_submit_inode_data_buffers.
2031 * We can also reach here via shrink_page_list but it
2032 * should never be for direct reclaim so warn if that
2035 WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) ==
2040 /* now mark the buffer_heads as dirty and uptodate */
2041 block_commit_write(page, 0, len);
2043 if (PageChecked(page) && ext4_should_journal_data(inode))
2045 * It's mmapped pagecache. Add buffers and journal it. There
2046 * doesn't seem much point in redirtying the page here.
2048 return __ext4_journalled_writepage(page, len);
2050 if (buffer_uninit(page_bufs)) {
2051 ext4_set_bh_endio(page_bufs, inode);
2052 ret = block_write_full_page_endio(page, noalloc_get_block_write,
2053 wbc, ext4_end_io_buffer_write);
2055 ret = block_write_full_page(page, noalloc_get_block_write,
2062 * This is called via ext4_da_writepages() to
2063 * calculate the total number of credits to reserve to fit
2064 * a single extent allocation into a single transaction,
2065 * ext4_da_writpeages() will loop calling this before
2066 * the block allocation.
2069 static int ext4_da_writepages_trans_blocks(struct inode *inode)
2071 int max_blocks = EXT4_I(inode)->i_reserved_data_blocks;
2074 * With non-extent format the journal credit needed to
2075 * insert nrblocks contiguous block is dependent on
2076 * number of contiguous block. So we will limit
2077 * number of contiguous block to a sane value
2079 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) &&
2080 (max_blocks > EXT4_MAX_TRANS_DATA))
2081 max_blocks = EXT4_MAX_TRANS_DATA;
2083 return ext4_chunk_trans_blocks(inode, max_blocks);
2087 * write_cache_pages_da - walk the list of dirty pages of the given
2088 * address space and accumulate pages that need writing, and call
2089 * mpage_da_map_and_submit to map a single contiguous memory region
2090 * and then write them.
2092 static int write_cache_pages_da(struct address_space *mapping,
2093 struct writeback_control *wbc,
2094 struct mpage_da_data *mpd,
2095 pgoff_t *done_index)
2097 struct buffer_head *bh, *head;
2098 struct inode *inode = mapping->host;
2099 struct pagevec pvec;
2100 unsigned int nr_pages;
2103 long nr_to_write = wbc->nr_to_write;
2104 int i, tag, ret = 0;
2106 memset(mpd, 0, sizeof(struct mpage_da_data));
2109 pagevec_init(&pvec, 0);
2110 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2111 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2113 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2114 tag = PAGECACHE_TAG_TOWRITE;
2116 tag = PAGECACHE_TAG_DIRTY;
2118 *done_index = index;
2119 while (index <= end) {
2120 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
2121 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
2125 for (i = 0; i < nr_pages; i++) {
2126 struct page *page = pvec.pages[i];
2129 * At this point, the page may be truncated or
2130 * invalidated (changing page->mapping to NULL), or
2131 * even swizzled back from swapper_space to tmpfs file
2132 * mapping. However, page->index will not change
2133 * because we have a reference on the page.
2135 if (page->index > end)
2138 *done_index = page->index + 1;
2141 * If we can't merge this page, and we have
2142 * accumulated an contiguous region, write it
2144 if ((mpd->next_page != page->index) &&
2145 (mpd->next_page != mpd->first_page)) {
2146 mpage_da_map_and_submit(mpd);
2147 goto ret_extent_tail;
2153 * If the page is no longer dirty, or its
2154 * mapping no longer corresponds to inode we
2155 * are writing (which means it has been
2156 * truncated or invalidated), or the page is
2157 * already under writeback and we are not
2158 * doing a data integrity writeback, skip the page
2160 if (!PageDirty(page) ||
2161 (PageWriteback(page) &&
2162 (wbc->sync_mode == WB_SYNC_NONE)) ||
2163 unlikely(page->mapping != mapping)) {
2168 wait_on_page_writeback(page);
2169 BUG_ON(PageWriteback(page));
2171 if (mpd->next_page != page->index)
2172 mpd->first_page = page->index;
2173 mpd->next_page = page->index + 1;
2174 logical = (sector_t) page->index <<
2175 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2177 if (!page_has_buffers(page)) {
2178 mpage_add_bh_to_extent(mpd, logical,
2180 (1 << BH_Dirty) | (1 << BH_Uptodate));
2182 goto ret_extent_tail;
2185 * Page with regular buffer heads,
2186 * just add all dirty ones
2188 head = page_buffers(page);
2191 BUG_ON(buffer_locked(bh));
2193 * We need to try to allocate
2194 * unmapped blocks in the same page.
2195 * Otherwise we won't make progress
2196 * with the page in ext4_writepage
2198 if (ext4_bh_delay_or_unwritten(NULL, bh)) {
2199 mpage_add_bh_to_extent(mpd, logical,
2203 goto ret_extent_tail;
2204 } else if (buffer_dirty(bh) && (buffer_mapped(bh))) {
2206 * mapped dirty buffer. We need
2207 * to update the b_state
2208 * because we look at b_state
2209 * in mpage_da_map_blocks. We
2210 * don't update b_size because
2211 * if we find an unmapped
2212 * buffer_head later we need to
2213 * use the b_state flag of that
2216 if (mpd->b_size == 0)
2217 mpd->b_state = bh->b_state & BH_FLAGS;
2220 } while ((bh = bh->b_this_page) != head);
2223 if (nr_to_write > 0) {
2225 if (nr_to_write == 0 &&
2226 wbc->sync_mode == WB_SYNC_NONE)
2228 * We stop writing back only if we are
2229 * not doing integrity sync. In case of
2230 * integrity sync we have to keep going
2231 * because someone may be concurrently
2232 * dirtying pages, and we might have
2233 * synced a lot of newly appeared dirty
2234 * pages, but have not synced all of the
2240 pagevec_release(&pvec);
2245 ret = MPAGE_DA_EXTENT_TAIL;
2247 pagevec_release(&pvec);
2253 static int ext4_da_writepages(struct address_space *mapping,
2254 struct writeback_control *wbc)
2257 int range_whole = 0;
2258 handle_t *handle = NULL;
2259 struct mpage_da_data mpd;
2260 struct inode *inode = mapping->host;
2261 int pages_written = 0;
2262 unsigned int max_pages;
2263 int range_cyclic, cycled = 1, io_done = 0;
2264 int needed_blocks, ret = 0;
2265 long desired_nr_to_write, nr_to_writebump = 0;
2266 loff_t range_start = wbc->range_start;
2267 struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
2268 pgoff_t done_index = 0;
2270 struct blk_plug plug;
2272 trace_ext4_da_writepages(inode, wbc);
2275 * No pages to write? This is mainly a kludge to avoid starting
2276 * a transaction for special inodes like journal inode on last iput()
2277 * because that could violate lock ordering on umount
2279 if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2283 * If the filesystem has aborted, it is read-only, so return
2284 * right away instead of dumping stack traces later on that
2285 * will obscure the real source of the problem. We test
2286 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2287 * the latter could be true if the filesystem is mounted
2288 * read-only, and in that case, ext4_da_writepages should
2289 * *never* be called, so if that ever happens, we would want
2292 if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED))
2295 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2298 range_cyclic = wbc->range_cyclic;
2299 if (wbc->range_cyclic) {
2300 index = mapping->writeback_index;
2303 wbc->range_start = index << PAGE_CACHE_SHIFT;
2304 wbc->range_end = LLONG_MAX;
2305 wbc->range_cyclic = 0;
2308 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2309 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2313 * This works around two forms of stupidity. The first is in
2314 * the writeback code, which caps the maximum number of pages
2315 * written to be 1024 pages. This is wrong on multiple
2316 * levels; different architectues have a different page size,
2317 * which changes the maximum amount of data which gets
2318 * written. Secondly, 4 megabytes is way too small. XFS
2319 * forces this value to be 16 megabytes by multiplying
2320 * nr_to_write parameter by four, and then relies on its
2321 * allocator to allocate larger extents to make them
2322 * contiguous. Unfortunately this brings us to the second
2323 * stupidity, which is that ext4's mballoc code only allocates
2324 * at most 2048 blocks. So we force contiguous writes up to
2325 * the number of dirty blocks in the inode, or
2326 * sbi->max_writeback_mb_bump whichever is smaller.
2328 max_pages = sbi->s_max_writeback_mb_bump << (20 - PAGE_CACHE_SHIFT);
2329 if (!range_cyclic && range_whole) {
2330 if (wbc->nr_to_write == LONG_MAX)
2331 desired_nr_to_write = wbc->nr_to_write;
2333 desired_nr_to_write = wbc->nr_to_write * 8;
2335 desired_nr_to_write = ext4_num_dirty_pages(inode, index,
2337 if (desired_nr_to_write > max_pages)
2338 desired_nr_to_write = max_pages;
2340 if (wbc->nr_to_write < desired_nr_to_write) {
2341 nr_to_writebump = desired_nr_to_write - wbc->nr_to_write;
2342 wbc->nr_to_write = desired_nr_to_write;
2346 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2347 tag_pages_for_writeback(mapping, index, end);
2349 blk_start_plug(&plug);
2350 while (!ret && wbc->nr_to_write > 0) {
2353 * we insert one extent at a time. So we need
2354 * credit needed for single extent allocation.
2355 * journalled mode is currently not supported
2358 BUG_ON(ext4_should_journal_data(inode));
2359 needed_blocks = ext4_da_writepages_trans_blocks(inode);
2361 /* start a new transaction*/
2362 handle = ext4_journal_start(inode, needed_blocks);
2363 if (IS_ERR(handle)) {
2364 ret = PTR_ERR(handle);
2365 ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
2366 "%ld pages, ino %lu; err %d", __func__,
2367 wbc->nr_to_write, inode->i_ino, ret);
2368 blk_finish_plug(&plug);
2369 goto out_writepages;
2373 * Now call write_cache_pages_da() to find the next
2374 * contiguous region of logical blocks that need
2375 * blocks to be allocated by ext4 and submit them.
2377 ret = write_cache_pages_da(mapping, wbc, &mpd, &done_index);
2379 * If we have a contiguous extent of pages and we
2380 * haven't done the I/O yet, map the blocks and submit
2383 if (!mpd.io_done && mpd.next_page != mpd.first_page) {
2384 mpage_da_map_and_submit(&mpd);
2385 ret = MPAGE_DA_EXTENT_TAIL;
2387 trace_ext4_da_write_pages(inode, &mpd);
2388 wbc->nr_to_write -= mpd.pages_written;
2390 ext4_journal_stop(handle);
2392 if ((mpd.retval == -ENOSPC) && sbi->s_journal) {
2393 /* commit the transaction which would
2394 * free blocks released in the transaction
2397 jbd2_journal_force_commit_nested(sbi->s_journal);
2399 } else if (ret == MPAGE_DA_EXTENT_TAIL) {
2401 * Got one extent now try with rest of the pages.
2402 * If mpd.retval is set -EIO, journal is aborted.
2403 * So we don't need to write any more.
2405 pages_written += mpd.pages_written;
2408 } else if (wbc->nr_to_write)
2410 * There is no more writeout needed
2411 * or we requested for a noblocking writeout
2412 * and we found the device congested
2416 blk_finish_plug(&plug);
2417 if (!io_done && !cycled) {
2420 wbc->range_start = index << PAGE_CACHE_SHIFT;
2421 wbc->range_end = mapping->writeback_index - 1;
2426 wbc->range_cyclic = range_cyclic;
2427 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2429 * set the writeback_index so that range_cyclic
2430 * mode will write it back later
2432 mapping->writeback_index = done_index;
2435 wbc->nr_to_write -= nr_to_writebump;
2436 wbc->range_start = range_start;
2437 trace_ext4_da_writepages_result(inode, wbc, ret, pages_written);
2441 #define FALL_BACK_TO_NONDELALLOC 1
2442 static int ext4_nonda_switch(struct super_block *sb)
2444 s64 free_blocks, dirty_blocks;
2445 struct ext4_sb_info *sbi = EXT4_SB(sb);
2448 * switch to non delalloc mode if we are running low
2449 * on free block. The free block accounting via percpu
2450 * counters can get slightly wrong with percpu_counter_batch getting
2451 * accumulated on each CPU without updating global counters
2452 * Delalloc need an accurate free block accounting. So switch
2453 * to non delalloc when we are near to error range.
2455 free_blocks = EXT4_C2B(sbi,
2456 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
2457 dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyclusters_counter);
2458 if (2 * free_blocks < 3 * dirty_blocks ||
2459 free_blocks < (dirty_blocks + EXT4_FREECLUSTERS_WATERMARK)) {
2461 * free block count is less than 150% of dirty blocks
2462 * or free blocks is less than watermark
2467 * Even if we don't switch but are nearing capacity,
2468 * start pushing delalloc when 1/2 of free blocks are dirty.
2470 if (free_blocks < 2 * dirty_blocks)
2471 writeback_inodes_sb_if_idle(sb, WB_REASON_FS_FREE_SPACE);
2476 static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
2477 loff_t pos, unsigned len, unsigned flags,
2478 struct page **pagep, void **fsdata)
2480 int ret, retries = 0;
2483 struct inode *inode = mapping->host;
2486 index = pos >> PAGE_CACHE_SHIFT;
2488 if (ext4_nonda_switch(inode->i_sb)) {
2489 *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
2490 return ext4_write_begin(file, mapping, pos,
2491 len, flags, pagep, fsdata);
2493 *fsdata = (void *)0;
2494 trace_ext4_da_write_begin(inode, pos, len, flags);
2497 * With delayed allocation, we don't log the i_disksize update
2498 * if there is delayed block allocation. But we still need
2499 * to journalling the i_disksize update if writes to the end
2500 * of file which has an already mapped buffer.
2502 handle = ext4_journal_start(inode, 1);
2503 if (IS_ERR(handle)) {
2504 ret = PTR_ERR(handle);
2507 /* We cannot recurse into the filesystem as the transaction is already
2509 flags |= AOP_FLAG_NOFS;
2511 page = grab_cache_page_write_begin(mapping, index, flags);
2513 ext4_journal_stop(handle);
2519 ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep);
2522 ext4_journal_stop(handle);
2523 page_cache_release(page);
2525 * block_write_begin may have instantiated a few blocks
2526 * outside i_size. Trim these off again. Don't need
2527 * i_size_read because we hold i_mutex.
2529 if (pos + len > inode->i_size)
2530 ext4_truncate_failed_write(inode);
2533 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
2540 * Check if we should update i_disksize
2541 * when write to the end of file but not require block allocation
2543 static int ext4_da_should_update_i_disksize(struct page *page,
2544 unsigned long offset)
2546 struct buffer_head *bh;
2547 struct inode *inode = page->mapping->host;
2551 bh = page_buffers(page);
2552 idx = offset >> inode->i_blkbits;
2554 for (i = 0; i < idx; i++)
2555 bh = bh->b_this_page;
2557 if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
2562 static int ext4_da_write_end(struct file *file,
2563 struct address_space *mapping,
2564 loff_t pos, unsigned len, unsigned copied,
2565 struct page *page, void *fsdata)
2567 struct inode *inode = mapping->host;
2569 handle_t *handle = ext4_journal_current_handle();
2571 unsigned long start, end;
2572 int write_mode = (int)(unsigned long)fsdata;
2574 if (write_mode == FALL_BACK_TO_NONDELALLOC) {
2575 switch (ext4_inode_journal_mode(inode)) {
2576 case EXT4_INODE_ORDERED_DATA_MODE:
2577 return ext4_ordered_write_end(file, mapping, pos,
2578 len, copied, page, fsdata);
2579 case EXT4_INODE_WRITEBACK_DATA_MODE:
2580 return ext4_writeback_write_end(file, mapping, pos,
2581 len, copied, page, fsdata);
2587 trace_ext4_da_write_end(inode, pos, len, copied);
2588 start = pos & (PAGE_CACHE_SIZE - 1);
2589 end = start + copied - 1;
2592 * generic_write_end() will run mark_inode_dirty() if i_size
2593 * changes. So let's piggyback the i_disksize mark_inode_dirty
2597 new_i_size = pos + copied;
2598 if (copied && new_i_size > EXT4_I(inode)->i_disksize) {
2599 if (ext4_da_should_update_i_disksize(page, end)) {
2600 down_write(&EXT4_I(inode)->i_data_sem);
2601 if (new_i_size > EXT4_I(inode)->i_disksize) {
2603 * Updating i_disksize when extending file
2604 * without needing block allocation
2606 if (ext4_should_order_data(inode))
2607 ret = ext4_jbd2_file_inode(handle,
2610 EXT4_I(inode)->i_disksize = new_i_size;
2612 up_write(&EXT4_I(inode)->i_data_sem);
2613 /* We need to mark inode dirty even if
2614 * new_i_size is less that inode->i_size
2615 * bu greater than i_disksize.(hint delalloc)
2617 ext4_mark_inode_dirty(handle, inode);
2620 ret2 = generic_write_end(file, mapping, pos, len, copied,
2625 ret2 = ext4_journal_stop(handle);
2629 return ret ? ret : copied;
2632 static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
2635 * Drop reserved blocks
2637 BUG_ON(!PageLocked(page));
2638 if (!page_has_buffers(page))
2641 ext4_da_page_release_reservation(page, offset);
2644 ext4_invalidatepage(page, offset);
2650 * Force all delayed allocation blocks to be allocated for a given inode.
2652 int ext4_alloc_da_blocks(struct inode *inode)
2654 trace_ext4_alloc_da_blocks(inode);
2656 if (!EXT4_I(inode)->i_reserved_data_blocks &&
2657 !EXT4_I(inode)->i_reserved_meta_blocks)
2661 * We do something simple for now. The filemap_flush() will
2662 * also start triggering a write of the data blocks, which is
2663 * not strictly speaking necessary (and for users of
2664 * laptop_mode, not even desirable). However, to do otherwise
2665 * would require replicating code paths in:
2667 * ext4_da_writepages() ->
2668 * write_cache_pages() ---> (via passed in callback function)
2669 * __mpage_da_writepage() -->
2670 * mpage_add_bh_to_extent()
2671 * mpage_da_map_blocks()
2673 * The problem is that write_cache_pages(), located in
2674 * mm/page-writeback.c, marks pages clean in preparation for
2675 * doing I/O, which is not desirable if we're not planning on
2678 * We could call write_cache_pages(), and then redirty all of
2679 * the pages by calling redirty_page_for_writepage() but that
2680 * would be ugly in the extreme. So instead we would need to
2681 * replicate parts of the code in the above functions,
2682 * simplifying them because we wouldn't actually intend to
2683 * write out the pages, but rather only collect contiguous
2684 * logical block extents, call the multi-block allocator, and
2685 * then update the buffer heads with the block allocations.
2687 * For now, though, we'll cheat by calling filemap_flush(),
2688 * which will map the blocks, and start the I/O, but not
2689 * actually wait for the I/O to complete.
2691 return filemap_flush(inode->i_mapping);
2695 * bmap() is special. It gets used by applications such as lilo and by
2696 * the swapper to find the on-disk block of a specific piece of data.
2698 * Naturally, this is dangerous if the block concerned is still in the
2699 * journal. If somebody makes a swapfile on an ext4 data-journaling
2700 * filesystem and enables swap, then they may get a nasty shock when the
2701 * data getting swapped to that swapfile suddenly gets overwritten by
2702 * the original zero's written out previously to the journal and
2703 * awaiting writeback in the kernel's buffer cache.
2705 * So, if we see any bmap calls here on a modified, data-journaled file,
2706 * take extra steps to flush any blocks which might be in the cache.
2708 static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
2710 struct inode *inode = mapping->host;
2714 if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
2715 test_opt(inode->i_sb, DELALLOC)) {
2717 * With delalloc we want to sync the file
2718 * so that we can make sure we allocate
2721 filemap_write_and_wait(mapping);
2724 if (EXT4_JOURNAL(inode) &&
2725 ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {
2727 * This is a REALLY heavyweight approach, but the use of
2728 * bmap on dirty files is expected to be extremely rare:
2729 * only if we run lilo or swapon on a freshly made file
2730 * do we expect this to happen.
2732 * (bmap requires CAP_SYS_RAWIO so this does not
2733 * represent an unprivileged user DOS attack --- we'd be
2734 * in trouble if mortal users could trigger this path at
2737 * NB. EXT4_STATE_JDATA is not set on files other than
2738 * regular files. If somebody wants to bmap a directory
2739 * or symlink and gets confused because the buffer
2740 * hasn't yet been flushed to disk, they deserve
2741 * everything they get.
2744 ext4_clear_inode_state(inode, EXT4_STATE_JDATA);
2745 journal = EXT4_JOURNAL(inode);
2746 jbd2_journal_lock_updates(journal);
2747 err = jbd2_journal_flush(journal);
2748 jbd2_journal_unlock_updates(journal);
2754 return generic_block_bmap(mapping, block, ext4_get_block);
2757 static int ext4_readpage(struct file *file, struct page *page)
2759 trace_ext4_readpage(page);
2760 return mpage_readpage(page, ext4_get_block);
2764 ext4_readpages(struct file *file, struct address_space *mapping,
2765 struct list_head *pages, unsigned nr_pages)
2767 return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
2770 static void ext4_invalidatepage_free_endio(struct page *page, unsigned long offset)
2772 struct buffer_head *head, *bh;
2773 unsigned int curr_off = 0;
2775 if (!page_has_buffers(page))
2777 head = bh = page_buffers(page);
2779 if (offset <= curr_off && test_clear_buffer_uninit(bh)
2781 ext4_free_io_end(bh->b_private);
2782 bh->b_private = NULL;
2783 bh->b_end_io = NULL;
2785 curr_off = curr_off + bh->b_size;
2786 bh = bh->b_this_page;
2787 } while (bh != head);
2790 static void ext4_invalidatepage(struct page *page, unsigned long offset)
2792 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
2794 trace_ext4_invalidatepage(page, offset);
2797 * free any io_end structure allocated for buffers to be discarded
2799 if (ext4_should_dioread_nolock(page->mapping->host))
2800 ext4_invalidatepage_free_endio(page, offset);
2802 * If it's a full truncate we just forget about the pending dirtying
2805 ClearPageChecked(page);
2808 jbd2_journal_invalidatepage(journal, page, offset);
2810 block_invalidatepage(page, offset);
2813 static int ext4_releasepage(struct page *page, gfp_t wait)
2815 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
2817 trace_ext4_releasepage(page);
2819 WARN_ON(PageChecked(page));
2820 if (!page_has_buffers(page))
2823 return jbd2_journal_try_to_free_buffers(journal, page, wait);
2825 return try_to_free_buffers(page);
2829 * ext4_get_block used when preparing for a DIO write or buffer write.
2830 * We allocate an uinitialized extent if blocks haven't been allocated.
2831 * The extent will be converted to initialized after the IO is complete.
2833 static int ext4_get_block_write(struct inode *inode, sector_t iblock,
2834 struct buffer_head *bh_result, int create)
2836 ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n",
2837 inode->i_ino, create);
2838 return _ext4_get_block(inode, iblock, bh_result,
2839 EXT4_GET_BLOCKS_IO_CREATE_EXT);
2842 static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock,
2843 struct buffer_head *bh_result, int flags)
2845 handle_t *handle = ext4_journal_current_handle();
2846 struct ext4_map_blocks map;
2849 ext4_debug("ext4_get_block_write_nolock: inode %lu, flag %d\n",
2850 inode->i_ino, flags);
2852 flags = EXT4_GET_BLOCKS_NO_LOCK;
2854 map.m_lblk = iblock;
2855 map.m_len = bh_result->b_size >> inode->i_blkbits;
2857 ret = ext4_map_blocks(handle, inode, &map, flags);
2859 map_bh(bh_result, inode->i_sb, map.m_pblk);
2860 bh_result->b_state = (bh_result->b_state & ~EXT4_MAP_FLAGS) |
2862 bh_result->b_size = inode->i_sb->s_blocksize * map.m_len;
2868 static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
2869 ssize_t size, void *private, int ret,
2872 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
2873 ext4_io_end_t *io_end = iocb->private;
2874 struct workqueue_struct *wq;
2875 unsigned long flags;
2876 struct ext4_inode_info *ei;
2878 /* if not async direct IO or dio with 0 bytes write, just return */
2879 if (!io_end || !size)
2882 ext_debug("ext4_end_io_dio(): io_end 0x%p "
2883 "for inode %lu, iocb 0x%p, offset %llu, size %zd\n",
2884 iocb->private, io_end->inode->i_ino, iocb, offset,
2887 iocb->private = NULL;
2889 /* if not aio dio with unwritten extents, just free io and return */
2890 if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
2891 ext4_free_io_end(io_end);
2894 aio_complete(iocb, ret, 0);
2895 inode_dio_done(inode);
2899 io_end->offset = offset;
2900 io_end->size = size;
2902 io_end->iocb = iocb;
2903 io_end->result = ret;
2905 wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq;
2907 /* Add the io_end to per-inode completed aio dio list*/
2908 ei = EXT4_I(io_end->inode);
2909 spin_lock_irqsave(&ei->i_completed_io_lock, flags);
2910 list_add_tail(&io_end->list, &ei->i_completed_io_list);
2911 spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
2913 /* queue the work to convert unwritten extents to written */
2914 queue_work(wq, &io_end->work);
2917 static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate)
2919 ext4_io_end_t *io_end = bh->b_private;
2920 struct workqueue_struct *wq;
2921 struct inode *inode;
2922 unsigned long flags;
2924 if (!test_clear_buffer_uninit(bh) || !io_end)
2927 if (!(io_end->inode->i_sb->s_flags & MS_ACTIVE)) {
2928 ext4_msg(io_end->inode->i_sb, KERN_INFO,
2929 "sb umounted, discard end_io request for inode %lu",
2930 io_end->inode->i_ino);
2931 ext4_free_io_end(io_end);
2936 * It may be over-defensive here to check EXT4_IO_END_UNWRITTEN now,
2937 * but being more careful is always safe for the future change.
2939 inode = io_end->inode;
2940 ext4_set_io_unwritten_flag(inode, io_end);
2942 /* Add the io_end to per-inode completed io list*/
2943 spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags);
2944 list_add_tail(&io_end->list, &EXT4_I(inode)->i_completed_io_list);
2945 spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags);
2947 wq = EXT4_SB(inode->i_sb)->dio_unwritten_wq;
2948 /* queue the work to convert unwritten extents to written */
2949 queue_work(wq, &io_end->work);
2951 bh->b_private = NULL;
2952 bh->b_end_io = NULL;
2953 clear_buffer_uninit(bh);
2954 end_buffer_async_write(bh, uptodate);
2957 static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode)
2959 ext4_io_end_t *io_end;
2960 struct page *page = bh->b_page;
2961 loff_t offset = (sector_t)page->index << PAGE_CACHE_SHIFT;
2962 size_t size = bh->b_size;
2965 io_end = ext4_init_io_end(inode, GFP_ATOMIC);
2967 pr_warn_ratelimited("%s: allocation fail\n", __func__);
2971 io_end->offset = offset;
2972 io_end->size = size;
2974 * We need to hold a reference to the page to make sure it
2975 * doesn't get evicted before ext4_end_io_work() has a chance
2976 * to convert the extent from written to unwritten.
2978 io_end->page = page;
2979 get_page(io_end->page);
2981 bh->b_private = io_end;
2982 bh->b_end_io = ext4_end_io_buffer_write;
2987 * For ext4 extent files, ext4 will do direct-io write to holes,
2988 * preallocated extents, and those write extend the file, no need to
2989 * fall back to buffered IO.
2991 * For holes, we fallocate those blocks, mark them as uninitialized
2992 * If those blocks were preallocated, we mark sure they are splited, but
2993 * still keep the range to write as uninitialized.
2995 * The unwrritten extents will be converted to written when DIO is completed.
2996 * For async direct IO, since the IO may still pending when return, we
2997 * set up an end_io call back function, which will do the conversion
2998 * when async direct IO completed.
3000 * If the O_DIRECT write will extend the file then add this inode to the
3001 * orphan list. So recovery will truncate it back to the original size
3002 * if the machine crashes during the write.
3005 static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
3006 const struct iovec *iov, loff_t offset,
3007 unsigned long nr_segs)
3009 struct file *file = iocb->ki_filp;
3010 struct inode *inode = file->f_mapping->host;
3012 size_t count = iov_length(iov, nr_segs);
3014 loff_t final_size = offset + count;
3015 if (rw == WRITE && final_size <= inode->i_size) {
3018 BUG_ON(iocb->private == NULL);
3020 /* If we do a overwrite dio, i_mutex locking can be released */
3021 overwrite = *((int *)iocb->private);
3024 down_read(&EXT4_I(inode)->i_data_sem);
3025 mutex_unlock(&inode->i_mutex);
3029 * We could direct write to holes and fallocate.
3031 * Allocated blocks to fill the hole are marked as uninitialized
3032 * to prevent parallel buffered read to expose the stale data
3033 * before DIO complete the data IO.
3035 * As to previously fallocated extents, ext4 get_block
3036 * will just simply mark the buffer mapped but still
3037 * keep the extents uninitialized.
3039 * for non AIO case, we will convert those unwritten extents
3040 * to written after return back from blockdev_direct_IO.
3042 * for async DIO, the conversion needs to be defered when
3043 * the IO is completed. The ext4 end_io callback function
3044 * will be called to take care of the conversion work.
3045 * Here for async case, we allocate an io_end structure to
3048 iocb->private = NULL;
3049 EXT4_I(inode)->cur_aio_dio = NULL;
3050 if (!is_sync_kiocb(iocb)) {
3051 ext4_io_end_t *io_end =
3052 ext4_init_io_end(inode, GFP_NOFS);
3057 io_end->flag |= EXT4_IO_END_DIRECT;
3058 iocb->private = io_end;
3060 * we save the io structure for current async
3061 * direct IO, so that later ext4_map_blocks()
3062 * could flag the io structure whether there
3063 * is a unwritten extents needs to be converted
3064 * when IO is completed.
3066 EXT4_I(inode)->cur_aio_dio = iocb->private;
3070 ret = __blockdev_direct_IO(rw, iocb, inode,
3071 inode->i_sb->s_bdev, iov,
3073 ext4_get_block_write_nolock,
3078 ret = __blockdev_direct_IO(rw, iocb, inode,
3079 inode->i_sb->s_bdev, iov,
3081 ext4_get_block_write,
3086 EXT4_I(inode)->cur_aio_dio = NULL;
3088 * The io_end structure takes a reference to the inode,
3089 * that structure needs to be destroyed and the
3090 * reference to the inode need to be dropped, when IO is
3091 * complete, even with 0 byte write, or failed.
3093 * In the successful AIO DIO case, the io_end structure will be
3094 * desctroyed and the reference to the inode will be dropped
3095 * after the end_io call back function is called.
3097 * In the case there is 0 byte write, or error case, since
3098 * VFS direct IO won't invoke the end_io call back function,
3099 * we need to free the end_io structure here.
3101 if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
3102 ext4_free_io_end(iocb->private);
3103 iocb->private = NULL;
3104 } else if (ret > 0 && !overwrite && ext4_test_inode_state(inode,
3105 EXT4_STATE_DIO_UNWRITTEN)) {
3108 * for non AIO case, since the IO is already
3109 * completed, we could do the conversion right here
3111 err = ext4_convert_unwritten_extents(inode,
3115 ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3119 /* take i_mutex locking again if we do a ovewrite dio */
3121 up_read(&EXT4_I(inode)->i_data_sem);
3122 mutex_lock(&inode->i_mutex);
3128 /* for write the the end of file case, we fall back to old way */
3129 return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3132 static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
3133 const struct iovec *iov, loff_t offset,
3134 unsigned long nr_segs)
3136 struct file *file = iocb->ki_filp;
3137 struct inode *inode = file->f_mapping->host;
3141 * If we are doing data journalling we don't support O_DIRECT
3143 if (ext4_should_journal_data(inode))
3146 trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);
3147 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3148 ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
3150 ret = ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3151 trace_ext4_direct_IO_exit(inode, offset,
3152 iov_length(iov, nr_segs), rw, ret);
3157 * Pages can be marked dirty completely asynchronously from ext4's journalling
3158 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3159 * much here because ->set_page_dirty is called under VFS locks. The page is
3160 * not necessarily locked.
3162 * We cannot just dirty the page and leave attached buffers clean, because the
3163 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3164 * or jbddirty because all the journalling code will explode.
3166 * So what we do is to mark the page "pending dirty" and next time writepage
3167 * is called, propagate that into the buffers appropriately.
3169 static int ext4_journalled_set_page_dirty(struct page *page)
3171 SetPageChecked(page);
3172 return __set_page_dirty_nobuffers(page);
3175 static const struct address_space_operations ext4_ordered_aops = {
3176 .readpage = ext4_readpage,
3177 .readpages = ext4_readpages,
3178 .writepage = ext4_writepage,
3179 .write_begin = ext4_write_begin,
3180 .write_end = ext4_ordered_write_end,
3182 .invalidatepage = ext4_invalidatepage,
3183 .releasepage = ext4_releasepage,
3184 .direct_IO = ext4_direct_IO,
3185 .migratepage = buffer_migrate_page,
3186 .is_partially_uptodate = block_is_partially_uptodate,
3187 .error_remove_page = generic_error_remove_page,
3190 static const struct address_space_operations ext4_writeback_aops = {
3191 .readpage = ext4_readpage,
3192 .readpages = ext4_readpages,
3193 .writepage = ext4_writepage,
3194 .write_begin = ext4_write_begin,
3195 .write_end = ext4_writeback_write_end,
3197 .invalidatepage = ext4_invalidatepage,
3198 .releasepage = ext4_releasepage,
3199 .direct_IO = ext4_direct_IO,
3200 .migratepage = buffer_migrate_page,
3201 .is_partially_uptodate = block_is_partially_uptodate,
3202 .error_remove_page = generic_error_remove_page,
3205 static const struct address_space_operations ext4_journalled_aops = {
3206 .readpage = ext4_readpage,
3207 .readpages = ext4_readpages,
3208 .writepage = ext4_writepage,
3209 .write_begin = ext4_write_begin,
3210 .write_end = ext4_journalled_write_end,
3211 .set_page_dirty = ext4_journalled_set_page_dirty,
3213 .invalidatepage = ext4_invalidatepage,
3214 .releasepage = ext4_releasepage,
3215 .direct_IO = ext4_direct_IO,
3216 .is_partially_uptodate = block_is_partially_uptodate,
3217 .error_remove_page = generic_error_remove_page,
3220 static const struct address_space_operations ext4_da_aops = {
3221 .readpage = ext4_readpage,
3222 .readpages = ext4_readpages,
3223 .writepage = ext4_writepage,
3224 .writepages = ext4_da_writepages,
3225 .write_begin = ext4_da_write_begin,
3226 .write_end = ext4_da_write_end,
3228 .invalidatepage = ext4_da_invalidatepage,
3229 .releasepage = ext4_releasepage,
3230 .direct_IO = ext4_direct_IO,
3231 .migratepage = buffer_migrate_page,
3232 .is_partially_uptodate = block_is_partially_uptodate,
3233 .error_remove_page = generic_error_remove_page,
3236 void ext4_set_aops(struct inode *inode)
3238 switch (ext4_inode_journal_mode(inode)) {
3239 case EXT4_INODE_ORDERED_DATA_MODE:
3240 if (test_opt(inode->i_sb, DELALLOC))
3241 inode->i_mapping->a_ops = &ext4_da_aops;
3243 inode->i_mapping->a_ops = &ext4_ordered_aops;
3245 case EXT4_INODE_WRITEBACK_DATA_MODE:
3246 if (test_opt(inode->i_sb, DELALLOC))
3247 inode->i_mapping->a_ops = &ext4_da_aops;
3249 inode->i_mapping->a_ops = &ext4_writeback_aops;
3251 case EXT4_INODE_JOURNAL_DATA_MODE:
3252 inode->i_mapping->a_ops = &ext4_journalled_aops;
3261 * ext4_discard_partial_page_buffers()
3262 * Wrapper function for ext4_discard_partial_page_buffers_no_lock.
3263 * This function finds and locks the page containing the offset
3264 * "from" and passes it to ext4_discard_partial_page_buffers_no_lock.
3265 * Calling functions that already have the page locked should call
3266 * ext4_discard_partial_page_buffers_no_lock directly.
3268 int ext4_discard_partial_page_buffers(handle_t *handle,
3269 struct address_space *mapping, loff_t from,
3270 loff_t length, int flags)
3272 struct inode *inode = mapping->host;
3276 page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT,
3277 mapping_gfp_mask(mapping) & ~__GFP_FS);
3281 err = ext4_discard_partial_page_buffers_no_lock(handle, inode, page,
3282 from, length, flags);
3285 page_cache_release(page);
3290 * ext4_discard_partial_page_buffers_no_lock()
3291 * Zeros a page range of length 'length' starting from offset 'from'.
3292 * Buffer heads that correspond to the block aligned regions of the
3293 * zeroed range will be unmapped. Unblock aligned regions
3294 * will have the corresponding buffer head mapped if needed so that
3295 * that region of the page can be updated with the partial zero out.
3297 * This function assumes that the page has already been locked. The
3298 * The range to be discarded must be contained with in the given page.
3299 * If the specified range exceeds the end of the page it will be shortened
3300 * to the end of the page that corresponds to 'from'. This function is
3301 * appropriate for updating a page and it buffer heads to be unmapped and
3302 * zeroed for blocks that have been either released, or are going to be
3305 * handle: The journal handle
3306 * inode: The files inode
3307 * page: A locked page that contains the offset "from"
3308 * from: The starting byte offset (from the begining of the file)
3309 * to begin discarding
3310 * len: The length of bytes to discard
3311 * flags: Optional flags that may be used:
3313 * EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED
3314 * Only zero the regions of the page whose buffer heads
3315 * have already been unmapped. This flag is appropriate
3316 * for updateing the contents of a page whose blocks may
3317 * have already been released, and we only want to zero
3318 * out the regions that correspond to those released blocks.
3320 * Returns zero on sucess or negative on failure.
3322 static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
3323 struct inode *inode, struct page *page, loff_t from,
3324 loff_t length, int flags)
3326 ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
3327 unsigned int offset = from & (PAGE_CACHE_SIZE-1);
3328 unsigned int blocksize, max, pos;
3330 struct buffer_head *bh;
3333 blocksize = inode->i_sb->s_blocksize;
3334 max = PAGE_CACHE_SIZE - offset;
3336 if (index != page->index)
3340 * correct length if it does not fall between
3341 * 'from' and the end of the page
3343 if (length > max || length < 0)
3346 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
3348 if (!page_has_buffers(page))
3349 create_empty_buffers(page, blocksize, 0);
3351 /* Find the buffer that contains "offset" */
3352 bh = page_buffers(page);
3354 while (offset >= pos) {
3355 bh = bh->b_this_page;
3361 while (pos < offset + length) {
3362 unsigned int end_of_block, range_to_discard;
3366 /* The length of space left to zero and unmap */
3367 range_to_discard = offset + length - pos;
3369 /* The length of space until the end of the block */
3370 end_of_block = blocksize - (pos & (blocksize-1));
3373 * Do not unmap or zero past end of block
3374 * for this buffer head
3376 if (range_to_discard > end_of_block)
3377 range_to_discard = end_of_block;
3381 * Skip this buffer head if we are only zeroing unampped
3382 * regions of the page
3384 if (flags & EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED &&
3388 /* If the range is block aligned, unmap */
3389 if (range_to_discard == blocksize) {
3390 clear_buffer_dirty(bh);
3392 clear_buffer_mapped(bh);
3393 clear_buffer_req(bh);
3394 clear_buffer_new(bh);
3395 clear_buffer_delay(bh);
3396 clear_buffer_unwritten(bh);
3397 clear_buffer_uptodate(bh);
3398 zero_user(page, pos, range_to_discard);
3399 BUFFER_TRACE(bh, "Buffer discarded");
3404 * If this block is not completely contained in the range
3405 * to be discarded, then it is not going to be released. Because
3406 * we need to keep this block, we need to make sure this part
3407 * of the page is uptodate before we modify it by writeing
3408 * partial zeros on it.
3410 if (!buffer_mapped(bh)) {
3412 * Buffer head must be mapped before we can read
3415 BUFFER_TRACE(bh, "unmapped");
3416 ext4_get_block(inode, iblock, bh, 0);
3417 /* unmapped? It's a hole - nothing to do */
3418 if (!buffer_mapped(bh)) {
3419 BUFFER_TRACE(bh, "still unmapped");
3424 /* Ok, it's mapped. Make sure it's up-to-date */
3425 if (PageUptodate(page))
3426 set_buffer_uptodate(bh);
3428 if (!buffer_uptodate(bh)) {
3430 ll_rw_block(READ, 1, &bh);
3432 /* Uhhuh. Read error. Complain and punt.*/
3433 if (!buffer_uptodate(bh))
3437 if (ext4_should_journal_data(inode)) {
3438 BUFFER_TRACE(bh, "get write access");
3439 err = ext4_journal_get_write_access(handle, bh);
3444 zero_user(page, pos, range_to_discard);
3447 if (ext4_should_journal_data(inode)) {
3448 err = ext4_handle_dirty_metadata(handle, inode, bh);
3450 mark_buffer_dirty(bh);
3452 BUFFER_TRACE(bh, "Partial buffer zeroed");
3454 bh = bh->b_this_page;
3456 pos += range_to_discard;
3462 int ext4_can_truncate(struct inode *inode)
3464 if (S_ISREG(inode->i_mode))
3466 if (S_ISDIR(inode->i_mode))
3468 if (S_ISLNK(inode->i_mode))
3469 return !ext4_inode_is_fast_symlink(inode);
3474 * ext4_punch_hole: punches a hole in a file by releaseing the blocks
3475 * associated with the given offset and length
3477 * @inode: File inode
3478 * @offset: The offset where the hole will begin
3479 * @len: The length of the hole
3481 * Returns: 0 on sucess or negative on failure
3484 int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
3486 struct inode *inode = file->f_path.dentry->d_inode;
3487 if (!S_ISREG(inode->i_mode))
3490 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
3491 /* TODO: Add support for non extent hole punching */
3495 if (EXT4_SB(inode->i_sb)->s_cluster_ratio > 1) {
3496 /* TODO: Add support for bigalloc file systems */
3500 return ext4_ext_punch_hole(file, offset, length);
3506 * We block out ext4_get_block() block instantiations across the entire
3507 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
3508 * simultaneously on behalf of the same inode.
3510 * As we work through the truncate and commit bits of it to the journal there
3511 * is one core, guiding principle: the file's tree must always be consistent on
3512 * disk. We must be able to restart the truncate after a crash.
3514 * The file's tree may be transiently inconsistent in memory (although it
3515 * probably isn't), but whenever we close off and commit a journal transaction,
3516 * the contents of (the filesystem + the journal) must be consistent and
3517 * restartable. It's pretty simple, really: bottom up, right to left (although
3518 * left-to-right works OK too).
3520 * Note that at recovery time, journal replay occurs *before* the restart of
3521 * truncate against the orphan inode list.
3523 * The committed inode has the new, desired i_size (which is the same as
3524 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
3525 * that this inode's truncate did not complete and it will again call
3526 * ext4_truncate() to have another go. So there will be instantiated blocks
3527 * to the right of the truncation point in a crashed ext4 filesystem. But
3528 * that's fine - as long as they are linked from the inode, the post-crash
3529 * ext4_truncate() run will find them and release them.
3531 void ext4_truncate(struct inode *inode)
3533 trace_ext4_truncate_enter(inode);
3535 if (!ext4_can_truncate(inode))
3538 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3540 if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
3541 ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
3543 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3544 ext4_ext_truncate(inode);
3546 ext4_ind_truncate(inode);
3548 trace_ext4_truncate_exit(inode);
3552 * ext4_get_inode_loc returns with an extra refcount against the inode's
3553 * underlying buffer_head on success. If 'in_mem' is true, we have all
3554 * data in memory that is needed to recreate the on-disk version of this
3557 static int __ext4_get_inode_loc(struct inode *inode,
3558 struct ext4_iloc *iloc, int in_mem)
3560 struct ext4_group_desc *gdp;
3561 struct buffer_head *bh;
3562 struct super_block *sb = inode->i_sb;
3564 int inodes_per_block, inode_offset;
3567 if (!ext4_valid_inum(sb, inode->i_ino))
3570 iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
3571 gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
3576 * Figure out the offset within the block group inode table
3578 inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
3579 inode_offset = ((inode->i_ino - 1) %
3580 EXT4_INODES_PER_GROUP(sb));
3581 block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
3582 iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
3584 bh = sb_getblk(sb, block);
3586 EXT4_ERROR_INODE_BLOCK(inode, block,
3587 "unable to read itable block");
3590 if (!buffer_uptodate(bh)) {
3594 * If the buffer has the write error flag, we have failed
3595 * to write out another inode in the same block. In this
3596 * case, we don't have to read the block because we may
3597 * read the old inode data successfully.
3599 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
3600 set_buffer_uptodate(bh);
3602 if (buffer_uptodate(bh)) {
3603 /* someone brought it uptodate while we waited */
3609 * If we have all information of the inode in memory and this
3610 * is the only valid inode in the block, we need not read the
3614 struct buffer_head *bitmap_bh;
3617 start = inode_offset & ~(inodes_per_block - 1);
3619 /* Is the inode bitmap in cache? */
3620 bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
3625 * If the inode bitmap isn't in cache then the
3626 * optimisation may end up performing two reads instead
3627 * of one, so skip it.
3629 if (!buffer_uptodate(bitmap_bh)) {
3633 for (i = start; i < start + inodes_per_block; i++) {
3634 if (i == inode_offset)
3636 if (ext4_test_bit(i, bitmap_bh->b_data))
3640 if (i == start + inodes_per_block) {
3641 /* all other inodes are free, so skip I/O */
3642 memset(bh->b_data, 0, bh->b_size);
3643 set_buffer_uptodate(bh);
3651 * If we need to do any I/O, try to pre-readahead extra
3652 * blocks from the inode table.
3654 if (EXT4_SB(sb)->s_inode_readahead_blks) {
3655 ext4_fsblk_t b, end, table;
3658 table = ext4_inode_table(sb, gdp);
3659 /* s_inode_readahead_blks is always a power of 2 */
3660 b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1);
3663 end = b + EXT4_SB(sb)->s_inode_readahead_blks;
3664 num = EXT4_INODES_PER_GROUP(sb);
3665 if (ext4_has_group_desc_csum(sb))
3666 num -= ext4_itable_unused_count(sb, gdp);
3667 table += num / inodes_per_block;
3671 sb_breadahead(sb, b++);
3675 * There are other valid inodes in the buffer, this inode
3676 * has in-inode xattrs, or we don't have this inode in memory.
3677 * Read the block from disk.
3679 trace_ext4_load_inode(inode);
3681 bh->b_end_io = end_buffer_read_sync;
3682 submit_bh(READ | REQ_META | REQ_PRIO, bh);
3684 if (!buffer_uptodate(bh)) {
3685 EXT4_ERROR_INODE_BLOCK(inode, block,
3686 "unable to read itable block");
3696 int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
3698 /* We have all inode data except xattrs in memory here. */
3699 return __ext4_get_inode_loc(inode, iloc,
3700 !ext4_test_inode_state(inode, EXT4_STATE_XATTR));
3703 void ext4_set_inode_flags(struct inode *inode)
3705 unsigned int flags = EXT4_I(inode)->i_flags;
3707 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
3708 if (flags & EXT4_SYNC_FL)
3709 inode->i_flags |= S_SYNC;
3710 if (flags & EXT4_APPEND_FL)
3711 inode->i_flags |= S_APPEND;
3712 if (flags & EXT4_IMMUTABLE_FL)
3713 inode->i_flags |= S_IMMUTABLE;
3714 if (flags & EXT4_NOATIME_FL)
3715 inode->i_flags |= S_NOATIME;
3716 if (flags & EXT4_DIRSYNC_FL)
3717 inode->i_flags |= S_DIRSYNC;
3720 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
3721 void ext4_get_inode_flags(struct ext4_inode_info *ei)
3723 unsigned int vfs_fl;
3724 unsigned long old_fl, new_fl;
3727 vfs_fl = ei->vfs_inode.i_flags;
3728 old_fl = ei->i_flags;
3729 new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
3730 EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|
3732 if (vfs_fl & S_SYNC)
3733 new_fl |= EXT4_SYNC_FL;
3734 if (vfs_fl & S_APPEND)
3735 new_fl |= EXT4_APPEND_FL;
3736 if (vfs_fl & S_IMMUTABLE)
3737 new_fl |= EXT4_IMMUTABLE_FL;
3738 if (vfs_fl & S_NOATIME)
3739 new_fl |= EXT4_NOATIME_FL;
3740 if (vfs_fl & S_DIRSYNC)
3741 new_fl |= EXT4_DIRSYNC_FL;
3742 } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl);
3745 static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
3746 struct ext4_inode_info *ei)
3749 struct inode *inode = &(ei->vfs_inode);
3750 struct super_block *sb = inode->i_sb;
3752 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3753 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
3754 /* we are using combined 48 bit field */
3755 i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
3756 le32_to_cpu(raw_inode->i_blocks_lo);
3757 if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) {
3758 /* i_blocks represent file system block size */
3759 return i_blocks << (inode->i_blkbits - 9);
3764 return le32_to_cpu(raw_inode->i_blocks_lo);
3768 struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
3770 struct ext4_iloc iloc;
3771 struct ext4_inode *raw_inode;
3772 struct ext4_inode_info *ei;
3773 struct inode *inode;
3774 journal_t *journal = EXT4_SB(sb)->s_journal;
3780 inode = iget_locked(sb, ino);
3782 return ERR_PTR(-ENOMEM);
3783 if (!(inode->i_state & I_NEW))
3789 ret = __ext4_get_inode_loc(inode, &iloc, 0);
3792 raw_inode = ext4_raw_inode(&iloc);
3794 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
3795 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
3796 if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
3797 EXT4_INODE_SIZE(inode->i_sb)) {
3798 EXT4_ERROR_INODE(inode, "bad extra_isize (%u != %u)",
3799 EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize,
3800 EXT4_INODE_SIZE(inode->i_sb));
3805 ei->i_extra_isize = 0;
3807 /* Precompute checksum seed for inode metadata */
3808 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3809 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3810 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3812 __le32 inum = cpu_to_le32(inode->i_ino);
3813 __le32 gen = raw_inode->i_generation;
3814 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
3816 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
3820 if (!ext4_inode_csum_verify(inode, raw_inode, ei)) {
3821 EXT4_ERROR_INODE(inode, "checksum invalid");
3826 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
3827 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
3828 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
3829 if (!(test_opt(inode->i_sb, NO_UID32))) {
3830 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
3831 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
3833 i_uid_write(inode, i_uid);
3834 i_gid_write(inode, i_gid);
3835 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
3837 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
3838 ei->i_dir_start_lookup = 0;
3839 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
3840 /* We now have enough fields to check if the inode was active or not.
3841 * This is needed because nfsd might try to access dead inodes
3842 * the test is that same one that e2fsck uses
3843 * NeilBrown 1999oct15
3845 if (inode->i_nlink == 0) {
3846 if (inode->i_mode == 0 ||
3847 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
3848 /* this inode is deleted */
3852 /* The only unlinked inodes we let through here have
3853 * valid i_mode and are being read by the orphan
3854 * recovery code: that's fine, we're about to complete
3855 * the process of deleting those. */
3857 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
3858 inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
3859 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
3860 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT))
3862 ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
3863 inode->i_size = ext4_isize(raw_inode);
3864 ei->i_disksize = inode->i_size;
3866 ei->i_reserved_quota = 0;
3868 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
3869 ei->i_block_group = iloc.block_group;
3870 ei->i_last_alloc_group = ~0;
3872 * NOTE! The in-memory inode i_data array is in little-endian order
3873 * even on big-endian machines: we do NOT byteswap the block numbers!
3875 for (block = 0; block < EXT4_N_BLOCKS; block++)
3876 ei->i_data[block] = raw_inode->i_block[block];
3877 INIT_LIST_HEAD(&ei->i_orphan);
3880 * Set transaction id's of transactions that have to be committed
3881 * to finish f[data]sync. We set them to currently running transaction
3882 * as we cannot be sure that the inode or some of its metadata isn't
3883 * part of the transaction - the inode could have been reclaimed and
3884 * now it is reread from disk.
3887 transaction_t *transaction;
3890 read_lock(&journal->j_state_lock);
3891 if (journal->j_running_transaction)
3892 transaction = journal->j_running_transaction;
3894 transaction = journal->j_committing_transaction;
3896 tid = transaction->t_tid;
3898 tid = journal->j_commit_sequence;
3899 read_unlock(&journal->j_state_lock);
3900 ei->i_sync_tid = tid;
3901 ei->i_datasync_tid = tid;
3904 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
3905 if (ei->i_extra_isize == 0) {
3906 /* The extra space is currently unused. Use it. */
3907 ei->i_extra_isize = sizeof(struct ext4_inode) -
3908 EXT4_GOOD_OLD_INODE_SIZE;
3910 __le32 *magic = (void *)raw_inode +
3911 EXT4_GOOD_OLD_INODE_SIZE +
3913 if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC))
3914 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
3918 EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
3919 EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
3920 EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
3921 EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
3923 inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
3924 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
3925 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
3927 (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
3931 if (ei->i_file_acl &&
3932 !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) {
3933 EXT4_ERROR_INODE(inode, "bad extended attribute block %llu",
3937 } else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
3938 if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
3939 (S_ISLNK(inode->i_mode) &&
3940 !ext4_inode_is_fast_symlink(inode)))
3941 /* Validate extent which is part of inode */
3942 ret = ext4_ext_check_inode(inode);
3943 } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
3944 (S_ISLNK(inode->i_mode) &&
3945 !ext4_inode_is_fast_symlink(inode))) {
3946 /* Validate block references which are part of inode */
3947 ret = ext4_ind_check_inode(inode);
3952 if (S_ISREG(inode->i_mode)) {
3953 inode->i_op = &ext4_file_inode_operations;
3954 inode->i_fop = &ext4_file_operations;
3955 ext4_set_aops(inode);
3956 } else if (S_ISDIR(inode->i_mode)) {
3957 inode->i_op = &ext4_dir_inode_operations;
3958 inode->i_fop = &ext4_dir_operations;
3959 } else if (S_ISLNK(inode->i_mode)) {
3960 if (ext4_inode_is_fast_symlink(inode)) {
3961 inode->i_op = &ext4_fast_symlink_inode_operations;
3962 nd_terminate_link(ei->i_data, inode->i_size,
3963 sizeof(ei->i_data) - 1);
3965 inode->i_op = &ext4_symlink_inode_operations;
3966 ext4_set_aops(inode);
3968 } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
3969 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
3970 inode->i_op = &ext4_special_inode_operations;
3971 if (raw_inode->i_block[0])
3972 init_special_inode(inode, inode->i_mode,
3973 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
3975 init_special_inode(inode, inode->i_mode,
3976 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
3979 EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode);
3983 ext4_set_inode_flags(inode);
3984 unlock_new_inode(inode);
3990 return ERR_PTR(ret);
3993 static int ext4_inode_blocks_set(handle_t *handle,
3994 struct ext4_inode *raw_inode,
3995 struct ext4_inode_info *ei)
3997 struct inode *inode = &(ei->vfs_inode);
3998 u64 i_blocks = inode->i_blocks;
3999 struct super_block *sb = inode->i_sb;
4001 if (i_blocks <= ~0U) {
4003 * i_blocks can be represnted in a 32 bit variable
4004 * as multiple of 512 bytes
4006 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4007 raw_inode->i_blocks_high = 0;
4008 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4011 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE))
4014 if (i_blocks <= 0xffffffffffffULL) {
4016 * i_blocks can be represented in a 48 bit variable
4017 * as multiple of 512 bytes
4019 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4020 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
4021 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4023 ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4024 /* i_block is stored in file system block size */
4025 i_blocks = i_blocks >> (inode->i_blkbits - 9);
4026 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4027 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
4033 * Post the struct inode info into an on-disk inode location in the
4034 * buffer-cache. This gobbles the caller's reference to the
4035 * buffer_head in the inode location struct.
4037 * The caller must have write access to iloc->bh.
4039 static int ext4_do_update_inode(handle_t *handle,
4040 struct inode *inode,
4041 struct ext4_iloc *iloc)
4043 struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
4044 struct ext4_inode_info *ei = EXT4_I(inode);
4045 struct buffer_head *bh = iloc->bh;
4046 int err = 0, rc, block;
4050 /* For fields not not tracking in the in-memory inode,
4051 * initialise them to zero for new inodes. */
4052 if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
4053 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
4055 ext4_get_inode_flags(ei);
4056 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
4057 i_uid = i_uid_read(inode);
4058 i_gid = i_gid_read(inode);
4059 if (!(test_opt(inode->i_sb, NO_UID32))) {
4060 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
4061 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
4063 * Fix up interoperability with old kernels. Otherwise, old inodes get
4064 * re-used with the upper 16 bits of the uid/gid intact
4067 raw_inode->i_uid_high =
4068 cpu_to_le16(high_16_bits(i_uid));
4069 raw_inode->i_gid_high =
4070 cpu_to_le16(high_16_bits(i_gid));
4072 raw_inode->i_uid_high = 0;
4073 raw_inode->i_gid_high = 0;
4076 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid));
4077 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid));
4078 raw_inode->i_uid_high = 0;
4079 raw_inode->i_gid_high = 0;
4081 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
4083 EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
4084 EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
4085 EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
4086 EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
4088 if (ext4_inode_blocks_set(handle, raw_inode, ei))
4090 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
4091 raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
4092 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
4093 cpu_to_le32(EXT4_OS_HURD))
4094 raw_inode->i_file_acl_high =
4095 cpu_to_le16(ei->i_file_acl >> 32);
4096 raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
4097 ext4_isize_set(raw_inode, ei->i_disksize);
4098 if (ei->i_disksize > 0x7fffffffULL) {
4099 struct super_block *sb = inode->i_sb;
4100 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
4101 EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||
4102 EXT4_SB(sb)->s_es->s_rev_level ==
4103 cpu_to_le32(EXT4_GOOD_OLD_REV)) {
4104 /* If this is the first large file
4105 * created, add a flag to the superblock.
4107 err = ext4_journal_get_write_access(handle,
4108 EXT4_SB(sb)->s_sbh);
4111 ext4_update_dynamic_rev(sb);
4112 EXT4_SET_RO_COMPAT_FEATURE(sb,
4113 EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
4114 ext4_handle_sync(handle);
4115 err = ext4_handle_dirty_super(handle, sb);
4118 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
4119 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
4120 if (old_valid_dev(inode->i_rdev)) {
4121 raw_inode->i_block[0] =
4122 cpu_to_le32(old_encode_dev(inode->i_rdev));
4123 raw_inode->i_block[1] = 0;
4125 raw_inode->i_block[0] = 0;
4126 raw_inode->i_block[1] =
4127 cpu_to_le32(new_encode_dev(inode->i_rdev));
4128 raw_inode->i_block[2] = 0;
4131 for (block = 0; block < EXT4_N_BLOCKS; block++)
4132 raw_inode->i_block[block] = ei->i_data[block];
4134 raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
4135 if (ei->i_extra_isize) {
4136 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4137 raw_inode->i_version_hi =
4138 cpu_to_le32(inode->i_version >> 32);
4139 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
4142 ext4_inode_csum_set(inode, raw_inode, ei);
4144 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
4145 rc = ext4_handle_dirty_metadata(handle, NULL, bh);
4148 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
4150 ext4_update_inode_fsync_trans(handle, inode, 0);
4153 ext4_std_error(inode->i_sb, err);
4158 * ext4_write_inode()
4160 * We are called from a few places:
4162 * - Within generic_file_write() for O_SYNC files.
4163 * Here, there will be no transaction running. We wait for any running
4164 * trasnaction to commit.
4166 * - Within sys_sync(), kupdate and such.
4167 * We wait on commit, if tol to.
4169 * - Within prune_icache() (PF_MEMALLOC == true)
4170 * Here we simply return. We can't afford to block kswapd on the
4173 * In all cases it is actually safe for us to return without doing anything,
4174 * because the inode has been copied into a raw inode buffer in
4175 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
4178 * Note that we are absolutely dependent upon all inode dirtiers doing the
4179 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4180 * which we are interested.
4182 * It would be a bug for them to not do this. The code:
4184 * mark_inode_dirty(inode)
4186 * inode->i_size = expr;
4188 * is in error because a kswapd-driven write_inode() could occur while
4189 * `stuff()' is running, and the new i_size will be lost. Plus the inode
4190 * will no longer be on the superblock's dirty inode list.
4192 int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
4196 if (current->flags & PF_MEMALLOC)
4199 if (EXT4_SB(inode->i_sb)->s_journal) {
4200 if (ext4_journal_current_handle()) {
4201 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
4206 if (wbc->sync_mode != WB_SYNC_ALL)
4209 err = ext4_force_commit(inode->i_sb);
4211 struct ext4_iloc iloc;
4213 err = __ext4_get_inode_loc(inode, &iloc, 0);
4216 if (wbc->sync_mode == WB_SYNC_ALL)
4217 sync_dirty_buffer(iloc.bh);
4218 if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) {
4219 EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr,
4220 "IO error syncing inode");
4231 * Called from notify_change.
4233 * We want to trap VFS attempts to truncate the file as soon as
4234 * possible. In particular, we want to make sure that when the VFS
4235 * shrinks i_size, we put the inode on the orphan list and modify
4236 * i_disksize immediately, so that during the subsequent flushing of
4237 * dirty pages and freeing of disk blocks, we can guarantee that any
4238 * commit will leave the blocks being flushed in an unused state on
4239 * disk. (On recovery, the inode will get truncated and the blocks will
4240 * be freed, so we have a strong guarantee that no future commit will
4241 * leave these blocks visible to the user.)
4243 * Another thing we have to assure is that if we are in ordered mode
4244 * and inode is still attached to the committing transaction, we must
4245 * we start writeout of all the dirty pages which are being truncated.
4246 * This way we are sure that all the data written in the previous
4247 * transaction are already on disk (truncate waits for pages under
4250 * Called with inode->i_mutex down.
4252 int ext4_setattr(struct dentry *dentry, struct iattr *attr)
4254 struct inode *inode = dentry->d_inode;
4257 const unsigned int ia_valid = attr->ia_valid;
4259 error = inode_change_ok(inode, attr);
4263 if (is_quota_modification(inode, attr))
4264 dquot_initialize(inode);
4265 if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) ||
4266 (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) {
4269 /* (user+group)*(old+new) structure, inode write (sb,
4270 * inode block, ? - but truncate inode update has it) */
4271 handle = ext4_journal_start(inode, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)+
4272 EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb))+3);
4273 if (IS_ERR(handle)) {
4274 error = PTR_ERR(handle);
4277 error = dquot_transfer(inode, attr);
4279 ext4_journal_stop(handle);
4282 /* Update corresponding info in inode so that everything is in
4283 * one transaction */
4284 if (attr->ia_valid & ATTR_UID)
4285 inode->i_uid = attr->ia_uid;
4286 if (attr->ia_valid & ATTR_GID)
4287 inode->i_gid = attr->ia_gid;
4288 error = ext4_mark_inode_dirty(handle, inode);
4289 ext4_journal_stop(handle);
4292 if (attr->ia_valid & ATTR_SIZE) {
4293 inode_dio_wait(inode);
4295 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4296 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4298 if (attr->ia_size > sbi->s_bitmap_maxbytes)
4303 if (S_ISREG(inode->i_mode) &&
4304 attr->ia_valid & ATTR_SIZE &&
4305 (attr->ia_size < inode->i_size)) {
4308 handle = ext4_journal_start(inode, 3);
4309 if (IS_ERR(handle)) {
4310 error = PTR_ERR(handle);
4313 if (ext4_handle_valid(handle)) {
4314 error = ext4_orphan_add(handle, inode);
4317 EXT4_I(inode)->i_disksize = attr->ia_size;
4318 rc = ext4_mark_inode_dirty(handle, inode);
4321 ext4_journal_stop(handle);
4323 if (ext4_should_order_data(inode)) {
4324 error = ext4_begin_ordered_truncate(inode,
4327 /* Do as much error cleanup as possible */
4328 handle = ext4_journal_start(inode, 3);
4329 if (IS_ERR(handle)) {
4330 ext4_orphan_del(NULL, inode);
4333 ext4_orphan_del(handle, inode);
4335 ext4_journal_stop(handle);
4341 if (attr->ia_valid & ATTR_SIZE) {
4342 if (attr->ia_size != i_size_read(inode))
4343 truncate_setsize(inode, attr->ia_size);
4344 ext4_truncate(inode);
4348 setattr_copy(inode, attr);
4349 mark_inode_dirty(inode);
4353 * If the call to ext4_truncate failed to get a transaction handle at
4354 * all, we need to clean up the in-core orphan list manually.
4356 if (orphan && inode->i_nlink)
4357 ext4_orphan_del(NULL, inode);
4359 if (!rc && (ia_valid & ATTR_MODE))
4360 rc = ext4_acl_chmod(inode);
4363 ext4_std_error(inode->i_sb, error);
4369 int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
4372 struct inode *inode;
4373 unsigned long delalloc_blocks;
4375 inode = dentry->d_inode;
4376 generic_fillattr(inode, stat);
4379 * We can't update i_blocks if the block allocation is delayed
4380 * otherwise in the case of system crash before the real block
4381 * allocation is done, we will have i_blocks inconsistent with
4382 * on-disk file blocks.
4383 * We always keep i_blocks updated together with real
4384 * allocation. But to not confuse with user, stat
4385 * will return the blocks that include the delayed allocation
4386 * blocks for this file.
4388 delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb),
4389 EXT4_I(inode)->i_reserved_data_blocks);
4391 stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
4395 static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
4397 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4398 return ext4_ind_trans_blocks(inode, nrblocks, chunk);
4399 return ext4_ext_index_trans_blocks(inode, nrblocks, chunk);
4403 * Account for index blocks, block groups bitmaps and block group
4404 * descriptor blocks if modify datablocks and index blocks
4405 * worse case, the indexs blocks spread over different block groups
4407 * If datablocks are discontiguous, they are possible to spread over
4408 * different block groups too. If they are contiuguous, with flexbg,
4409 * they could still across block group boundary.
4411 * Also account for superblock, inode, quota and xattr blocks
4413 static int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
4415 ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
4421 * How many index blocks need to touch to modify nrblocks?
4422 * The "Chunk" flag indicating whether the nrblocks is
4423 * physically contiguous on disk
4425 * For Direct IO and fallocate, they calls get_block to allocate
4426 * one single extent at a time, so they could set the "Chunk" flag
4428 idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
4433 * Now let's see how many group bitmaps and group descriptors need
4443 if (groups > ngroups)
4445 if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
4446 gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
4448 /* bitmaps and block group descriptor blocks */
4449 ret += groups + gdpblocks;
4451 /* Blocks for super block, inode, quota and xattr blocks */
4452 ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
4458 * Calculate the total number of credits to reserve to fit
4459 * the modification of a single pages into a single transaction,
4460 * which may include multiple chunks of block allocations.
4462 * This could be called via ext4_write_begin()
4464 * We need to consider the worse case, when
4465 * one new block per extent.
4467 int ext4_writepage_trans_blocks(struct inode *inode)
4469 int bpp = ext4_journal_blocks_per_page(inode);
4472 ret = ext4_meta_trans_blocks(inode, bpp, 0);
4474 /* Account for data blocks for journalled mode */
4475 if (ext4_should_journal_data(inode))
4481 * Calculate the journal credits for a chunk of data modification.
4483 * This is called from DIO, fallocate or whoever calling
4484 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
4486 * journal buffers for data blocks are not included here, as DIO
4487 * and fallocate do no need to journal data buffers.
4489 int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
4491 return ext4_meta_trans_blocks(inode, nrblocks, 1);
4495 * The caller must have previously called ext4_reserve_inode_write().
4496 * Give this, we know that the caller already has write access to iloc->bh.
4498 int ext4_mark_iloc_dirty(handle_t *handle,
4499 struct inode *inode, struct ext4_iloc *iloc)
4503 if (IS_I_VERSION(inode))
4504 inode_inc_iversion(inode);
4506 /* the do_update_inode consumes one bh->b_count */
4509 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
4510 err = ext4_do_update_inode(handle, inode, iloc);
4516 * On success, We end up with an outstanding reference count against
4517 * iloc->bh. This _must_ be cleaned up later.
4521 ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
4522 struct ext4_iloc *iloc)
4526 err = ext4_get_inode_loc(inode, iloc);
4528 BUFFER_TRACE(iloc->bh, "get_write_access");
4529 err = ext4_journal_get_write_access(handle, iloc->bh);
4535 ext4_std_error(inode->i_sb, err);
4540 * Expand an inode by new_extra_isize bytes.
4541 * Returns 0 on success or negative error number on failure.
4543 static int ext4_expand_extra_isize(struct inode *inode,
4544 unsigned int new_extra_isize,
4545 struct ext4_iloc iloc,
4548 struct ext4_inode *raw_inode;
4549 struct ext4_xattr_ibody_header *header;
4551 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
4554 raw_inode = ext4_raw_inode(&iloc);
4556 header = IHDR(inode, raw_inode);
4558 /* No extended attributes present */
4559 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
4560 header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
4561 memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
4563 EXT4_I(inode)->i_extra_isize = new_extra_isize;
4567 /* try to expand with EAs present */
4568 return ext4_expand_extra_isize_ea(inode, new_extra_isize,
4573 * What we do here is to mark the in-core inode as clean with respect to inode
4574 * dirtiness (it may still be data-dirty).
4575 * This means that the in-core inode may be reaped by prune_icache
4576 * without having to perform any I/O. This is a very good thing,
4577 * because *any* task may call prune_icache - even ones which
4578 * have a transaction open against a different journal.
4580 * Is this cheating? Not really. Sure, we haven't written the
4581 * inode out, but prune_icache isn't a user-visible syncing function.
4582 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
4583 * we start and wait on commits.
4585 * Is this efficient/effective? Well, we're being nice to the system
4586 * by cleaning up our inodes proactively so they can be reaped
4587 * without I/O. But we are potentially leaving up to five seconds'
4588 * worth of inodes floating about which prune_icache wants us to
4589 * write out. One way to fix that would be to get prune_icache()
4590 * to do a write_super() to free up some memory. It has the desired
4593 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
4595 struct ext4_iloc iloc;
4596 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4597 static unsigned int mnt_count;
4601 trace_ext4_mark_inode_dirty(inode, _RET_IP_);
4602 err = ext4_reserve_inode_write(handle, inode, &iloc);
4603 if (ext4_handle_valid(handle) &&
4604 EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
4605 !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
4607 * We need extra buffer credits since we may write into EA block
4608 * with this same handle. If journal_extend fails, then it will
4609 * only result in a minor loss of functionality for that inode.
4610 * If this is felt to be critical, then e2fsck should be run to
4611 * force a large enough s_min_extra_isize.
4613 if ((jbd2_journal_extend(handle,
4614 EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
4615 ret = ext4_expand_extra_isize(inode,
4616 sbi->s_want_extra_isize,
4619 ext4_set_inode_state(inode,
4620 EXT4_STATE_NO_EXPAND);
4622 le16_to_cpu(sbi->s_es->s_mnt_count)) {
4623 ext4_warning(inode->i_sb,
4624 "Unable to expand inode %lu. Delete"
4625 " some EAs or run e2fsck.",
4628 le16_to_cpu(sbi->s_es->s_mnt_count);
4634 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
4639 * ext4_dirty_inode() is called from __mark_inode_dirty()
4641 * We're really interested in the case where a file is being extended.
4642 * i_size has been changed by generic_commit_write() and we thus need
4643 * to include the updated inode in the current transaction.
4645 * Also, dquot_alloc_block() will always dirty the inode when blocks
4646 * are allocated to the file.
4648 * If the inode is marked synchronous, we don't honour that here - doing
4649 * so would cause a commit on atime updates, which we don't bother doing.
4650 * We handle synchronous inodes at the highest possible level.
4652 void ext4_dirty_inode(struct inode *inode, int flags)
4656 handle = ext4_journal_start(inode, 2);
4660 ext4_mark_inode_dirty(handle, inode);
4662 ext4_journal_stop(handle);
4669 * Bind an inode's backing buffer_head into this transaction, to prevent
4670 * it from being flushed to disk early. Unlike
4671 * ext4_reserve_inode_write, this leaves behind no bh reference and
4672 * returns no iloc structure, so the caller needs to repeat the iloc
4673 * lookup to mark the inode dirty later.
4675 static int ext4_pin_inode(handle_t *handle, struct inode *inode)
4677 struct ext4_iloc iloc;
4681 err = ext4_get_inode_loc(inode, &iloc);
4683 BUFFER_TRACE(iloc.bh, "get_write_access");
4684 err = jbd2_journal_get_write_access(handle, iloc.bh);
4686 err = ext4_handle_dirty_metadata(handle,
4692 ext4_std_error(inode->i_sb, err);
4697 int ext4_change_inode_journal_flag(struct inode *inode, int val)
4704 * We have to be very careful here: changing a data block's
4705 * journaling status dynamically is dangerous. If we write a
4706 * data block to the journal, change the status and then delete
4707 * that block, we risk forgetting to revoke the old log record
4708 * from the journal and so a subsequent replay can corrupt data.
4709 * So, first we make sure that the journal is empty and that
4710 * nobody is changing anything.
4713 journal = EXT4_JOURNAL(inode);
4716 if (is_journal_aborted(journal))
4718 /* We have to allocate physical blocks for delalloc blocks
4719 * before flushing journal. otherwise delalloc blocks can not
4720 * be allocated any more. even more truncate on delalloc blocks
4721 * could trigger BUG by flushing delalloc blocks in journal.
4722 * There is no delalloc block in non-journal data mode.
4724 if (val && test_opt(inode->i_sb, DELALLOC)) {
4725 err = ext4_alloc_da_blocks(inode);
4730 jbd2_journal_lock_updates(journal);
4733 * OK, there are no updates running now, and all cached data is
4734 * synced to disk. We are now in a completely consistent state
4735 * which doesn't have anything in the journal, and we know that
4736 * no filesystem updates are running, so it is safe to modify
4737 * the inode's in-core data-journaling state flag now.
4741 ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
4743 jbd2_journal_flush(journal);
4744 ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
4746 ext4_set_aops(inode);
4748 jbd2_journal_unlock_updates(journal);
4750 /* Finally we can mark the inode as dirty. */
4752 handle = ext4_journal_start(inode, 1);
4754 return PTR_ERR(handle);
4756 err = ext4_mark_inode_dirty(handle, inode);
4757 ext4_handle_sync(handle);
4758 ext4_journal_stop(handle);
4759 ext4_std_error(inode->i_sb, err);
4764 static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
4766 return !buffer_mapped(bh);
4769 int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
4771 struct page *page = vmf->page;
4775 struct file *file = vma->vm_file;
4776 struct inode *inode = file->f_path.dentry->d_inode;
4777 struct address_space *mapping = inode->i_mapping;
4779 get_block_t *get_block;
4783 * This check is racy but catches the common case. We rely on
4784 * __block_page_mkwrite() to do a reliable check.
4786 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
4787 /* Delalloc case is easy... */
4788 if (test_opt(inode->i_sb, DELALLOC) &&
4789 !ext4_should_journal_data(inode) &&
4790 !ext4_nonda_switch(inode->i_sb)) {
4792 ret = __block_page_mkwrite(vma, vmf,
4793 ext4_da_get_block_prep);
4794 } while (ret == -ENOSPC &&
4795 ext4_should_retry_alloc(inode->i_sb, &retries));
4800 size = i_size_read(inode);
4801 /* Page got truncated from under us? */
4802 if (page->mapping != mapping || page_offset(page) > size) {
4804 ret = VM_FAULT_NOPAGE;
4808 if (page->index == size >> PAGE_CACHE_SHIFT)
4809 len = size & ~PAGE_CACHE_MASK;
4811 len = PAGE_CACHE_SIZE;
4813 * Return if we have all the buffers mapped. This avoids the need to do
4814 * journal_start/journal_stop which can block and take a long time
4816 if (page_has_buffers(page)) {
4817 if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
4818 ext4_bh_unmapped)) {
4819 /* Wait so that we don't change page under IO */
4820 wait_on_page_writeback(page);
4821 ret = VM_FAULT_LOCKED;
4826 /* OK, we need to fill the hole... */
4827 if (ext4_should_dioread_nolock(inode))
4828 get_block = ext4_get_block_write;
4830 get_block = ext4_get_block;
4832 handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
4833 if (IS_ERR(handle)) {
4834 ret = VM_FAULT_SIGBUS;
4837 ret = __block_page_mkwrite(vma, vmf, get_block);
4838 if (!ret && ext4_should_journal_data(inode)) {
4839 if (walk_page_buffers(handle, page_buffers(page), 0,
4840 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access)) {
4842 ret = VM_FAULT_SIGBUS;
4843 ext4_journal_stop(handle);
4846 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
4848 ext4_journal_stop(handle);
4849 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
4852 ret = block_page_mkwrite_return(ret);