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))
237 * Protect us against freezing - iput() caller didn't have to have any
238 * protection against it
240 sb_start_intwrite(inode->i_sb);
241 handle = ext4_journal_start(inode, ext4_blocks_for_truncate(inode)+3);
242 if (IS_ERR(handle)) {
243 ext4_std_error(inode->i_sb, PTR_ERR(handle));
245 * If we're going to skip the normal cleanup, we still need to
246 * make sure that the in-core orphan linked list is properly
249 ext4_orphan_del(NULL, inode);
250 sb_end_intwrite(inode->i_sb);
255 ext4_handle_sync(handle);
257 err = ext4_mark_inode_dirty(handle, inode);
259 ext4_warning(inode->i_sb,
260 "couldn't mark inode dirty (err %d)", err);
264 ext4_truncate(inode);
267 * ext4_ext_truncate() doesn't reserve any slop when it
268 * restarts journal transactions; therefore there may not be
269 * enough credits left in the handle to remove the inode from
270 * the orphan list and set the dtime field.
272 if (!ext4_handle_has_enough_credits(handle, 3)) {
273 err = ext4_journal_extend(handle, 3);
275 err = ext4_journal_restart(handle, 3);
277 ext4_warning(inode->i_sb,
278 "couldn't extend journal (err %d)", err);
280 ext4_journal_stop(handle);
281 ext4_orphan_del(NULL, inode);
282 sb_end_intwrite(inode->i_sb);
288 * Kill off the orphan record which ext4_truncate created.
289 * AKPM: I think this can be inside the above `if'.
290 * Note that ext4_orphan_del() has to be able to cope with the
291 * deletion of a non-existent orphan - this is because we don't
292 * know if ext4_truncate() actually created an orphan record.
293 * (Well, we could do this if we need to, but heck - it works)
295 ext4_orphan_del(handle, inode);
296 EXT4_I(inode)->i_dtime = get_seconds();
299 * One subtle ordering requirement: if anything has gone wrong
300 * (transaction abort, IO errors, whatever), then we can still
301 * do these next steps (the fs will already have been marked as
302 * having errors), but we can't free the inode if the mark_dirty
305 if (ext4_mark_inode_dirty(handle, inode))
306 /* If that failed, just do the required in-core inode clear. */
307 ext4_clear_inode(inode);
309 ext4_free_inode(handle, inode);
310 ext4_journal_stop(handle);
311 sb_end_intwrite(inode->i_sb);
314 ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
318 qsize_t *ext4_get_reserved_space(struct inode *inode)
320 return &EXT4_I(inode)->i_reserved_quota;
325 * Calculate the number of metadata blocks need to reserve
326 * to allocate a block located at @lblock
328 static int ext4_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
330 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
331 return ext4_ext_calc_metadata_amount(inode, lblock);
333 return ext4_ind_calc_metadata_amount(inode, lblock);
337 * Called with i_data_sem down, which is important since we can call
338 * ext4_discard_preallocations() from here.
340 void ext4_da_update_reserve_space(struct inode *inode,
341 int used, int quota_claim)
343 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
344 struct ext4_inode_info *ei = EXT4_I(inode);
346 spin_lock(&ei->i_block_reservation_lock);
347 trace_ext4_da_update_reserve_space(inode, used, quota_claim);
348 if (unlikely(used > ei->i_reserved_data_blocks)) {
349 ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, used %d "
350 "with only %d reserved data blocks",
351 __func__, inode->i_ino, used,
352 ei->i_reserved_data_blocks);
354 used = ei->i_reserved_data_blocks;
357 if (unlikely(ei->i_allocated_meta_blocks > ei->i_reserved_meta_blocks)) {
358 ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, allocated %d "
359 "with only %d reserved metadata blocks\n", __func__,
360 inode->i_ino, ei->i_allocated_meta_blocks,
361 ei->i_reserved_meta_blocks);
363 ei->i_allocated_meta_blocks = ei->i_reserved_meta_blocks;
366 /* Update per-inode reservations */
367 ei->i_reserved_data_blocks -= used;
368 ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks;
369 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
370 used + ei->i_allocated_meta_blocks);
371 ei->i_allocated_meta_blocks = 0;
373 if (ei->i_reserved_data_blocks == 0) {
375 * We can release all of the reserved metadata blocks
376 * only when we have written all of the delayed
379 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
380 ei->i_reserved_meta_blocks);
381 ei->i_reserved_meta_blocks = 0;
382 ei->i_da_metadata_calc_len = 0;
384 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
386 /* Update quota subsystem for data blocks */
388 dquot_claim_block(inode, EXT4_C2B(sbi, used));
391 * We did fallocate with an offset that is already delayed
392 * allocated. So on delayed allocated writeback we should
393 * not re-claim the quota for fallocated blocks.
395 dquot_release_reservation_block(inode, EXT4_C2B(sbi, used));
399 * If we have done all the pending block allocations and if
400 * there aren't any writers on the inode, we can discard the
401 * inode's preallocations.
403 if ((ei->i_reserved_data_blocks == 0) &&
404 (atomic_read(&inode->i_writecount) == 0))
405 ext4_discard_preallocations(inode);
408 static int __check_block_validity(struct inode *inode, const char *func,
410 struct ext4_map_blocks *map)
412 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
414 ext4_error_inode(inode, func, line, map->m_pblk,
415 "lblock %lu mapped to illegal pblock "
416 "(length %d)", (unsigned long) map->m_lblk,
423 #define check_block_validity(inode, map) \
424 __check_block_validity((inode), __func__, __LINE__, (map))
427 * Return the number of contiguous dirty pages in a given inode
428 * starting at page frame idx.
430 static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
431 unsigned int max_pages)
433 struct address_space *mapping = inode->i_mapping;
437 int i, nr_pages, done = 0;
441 pagevec_init(&pvec, 0);
444 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
446 (pgoff_t)PAGEVEC_SIZE);
449 for (i = 0; i < nr_pages; i++) {
450 struct page *page = pvec.pages[i];
451 struct buffer_head *bh, *head;
454 if (unlikely(page->mapping != mapping) ||
456 PageWriteback(page) ||
457 page->index != idx) {
462 if (page_has_buffers(page)) {
463 bh = head = page_buffers(page);
465 if (!buffer_delay(bh) &&
466 !buffer_unwritten(bh))
468 bh = bh->b_this_page;
469 } while (!done && (bh != head));
476 if (num >= max_pages) {
481 pagevec_release(&pvec);
487 * Sets the BH_Da_Mapped bit on the buffer heads corresponding to the given map.
489 static void set_buffers_da_mapped(struct inode *inode,
490 struct ext4_map_blocks *map)
492 struct address_space *mapping = inode->i_mapping;
497 index = map->m_lblk >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
498 end = (map->m_lblk + map->m_len - 1) >>
499 (PAGE_CACHE_SHIFT - inode->i_blkbits);
501 pagevec_init(&pvec, 0);
502 while (index <= end) {
503 nr_pages = pagevec_lookup(&pvec, mapping, index,
505 (pgoff_t)PAGEVEC_SIZE));
508 for (i = 0; i < nr_pages; i++) {
509 struct page *page = pvec.pages[i];
510 struct buffer_head *bh, *head;
512 if (unlikely(page->mapping != mapping) ||
516 if (page_has_buffers(page)) {
517 bh = head = page_buffers(page);
519 set_buffer_da_mapped(bh);
520 bh = bh->b_this_page;
521 } while (bh != head);
525 pagevec_release(&pvec);
530 * The ext4_map_blocks() function tries to look up the requested blocks,
531 * and returns if the blocks are already mapped.
533 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
534 * and store the allocated blocks in the result buffer head and mark it
537 * If file type is extents based, it will call ext4_ext_map_blocks(),
538 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
541 * On success, it returns the number of blocks being mapped or allocate.
542 * if create==0 and the blocks are pre-allocated and uninitialized block,
543 * the result buffer head is unmapped. If the create ==1, it will make sure
544 * the buffer head is mapped.
546 * It returns 0 if plain look up failed (blocks have not been allocated), in
547 * that case, buffer head is unmapped
549 * It returns the error in case of allocation failure.
551 int ext4_map_blocks(handle_t *handle, struct inode *inode,
552 struct ext4_map_blocks *map, int flags)
557 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
558 "logical block %lu\n", inode->i_ino, flags, map->m_len,
559 (unsigned long) map->m_lblk);
561 * Try to see if we can get the block without requesting a new
564 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
565 down_read((&EXT4_I(inode)->i_data_sem));
566 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
567 retval = ext4_ext_map_blocks(handle, inode, map, flags &
568 EXT4_GET_BLOCKS_KEEP_SIZE);
570 retval = ext4_ind_map_blocks(handle, inode, map, flags &
571 EXT4_GET_BLOCKS_KEEP_SIZE);
573 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
574 up_read((&EXT4_I(inode)->i_data_sem));
576 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
577 int ret = check_block_validity(inode, map);
582 /* If it is only a block(s) look up */
583 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
587 * Returns if the blocks have already allocated
589 * Note that if blocks have been preallocated
590 * ext4_ext_get_block() returns the create = 0
591 * with buffer head unmapped.
593 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
597 * When we call get_blocks without the create flag, the
598 * BH_Unwritten flag could have gotten set if the blocks
599 * requested were part of a uninitialized extent. We need to
600 * clear this flag now that we are committed to convert all or
601 * part of the uninitialized extent to be an initialized
602 * extent. This is because we need to avoid the combination
603 * of BH_Unwritten and BH_Mapped flags being simultaneously
604 * set on the buffer_head.
606 map->m_flags &= ~EXT4_MAP_UNWRITTEN;
609 * New blocks allocate and/or writing to uninitialized extent
610 * will possibly result in updating i_data, so we take
611 * the write lock of i_data_sem, and call get_blocks()
612 * with create == 1 flag.
614 down_write((&EXT4_I(inode)->i_data_sem));
617 * if the caller is from delayed allocation writeout path
618 * we have already reserved fs blocks for allocation
619 * let the underlying get_block() function know to
620 * avoid double accounting
622 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
623 ext4_set_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
625 * We need to check for EXT4 here because migrate
626 * could have changed the inode type in between
628 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
629 retval = ext4_ext_map_blocks(handle, inode, map, flags);
631 retval = ext4_ind_map_blocks(handle, inode, map, flags);
633 if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
635 * We allocated new blocks which will result in
636 * i_data's format changing. Force the migrate
637 * to fail by clearing migrate flags
639 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
643 * Update reserved blocks/metadata blocks after successful
644 * block allocation which had been deferred till now. We don't
645 * support fallocate for non extent files. So we can update
646 * reserve space here.
649 (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
650 ext4_da_update_reserve_space(inode, retval, 1);
652 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
653 ext4_clear_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
655 /* If we have successfully mapped the delayed allocated blocks,
656 * set the BH_Da_Mapped bit on them. Its important to do this
657 * under the protection of i_data_sem.
659 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
660 set_buffers_da_mapped(inode, map);
663 up_write((&EXT4_I(inode)->i_data_sem));
664 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
665 int ret = check_block_validity(inode, map);
672 /* Maximum number of blocks we map for direct IO at once. */
673 #define DIO_MAX_BLOCKS 4096
675 static int _ext4_get_block(struct inode *inode, sector_t iblock,
676 struct buffer_head *bh, int flags)
678 handle_t *handle = ext4_journal_current_handle();
679 struct ext4_map_blocks map;
680 int ret = 0, started = 0;
684 map.m_len = bh->b_size >> inode->i_blkbits;
686 if (flags && !handle) {
687 /* Direct IO write... */
688 if (map.m_len > DIO_MAX_BLOCKS)
689 map.m_len = DIO_MAX_BLOCKS;
690 dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
691 handle = ext4_journal_start(inode, dio_credits);
692 if (IS_ERR(handle)) {
693 ret = PTR_ERR(handle);
699 ret = ext4_map_blocks(handle, inode, &map, flags);
701 map_bh(bh, inode->i_sb, map.m_pblk);
702 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
703 bh->b_size = inode->i_sb->s_blocksize * map.m_len;
707 ext4_journal_stop(handle);
711 int ext4_get_block(struct inode *inode, sector_t iblock,
712 struct buffer_head *bh, int create)
714 return _ext4_get_block(inode, iblock, bh,
715 create ? EXT4_GET_BLOCKS_CREATE : 0);
719 * `handle' can be NULL if create is zero
721 struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
722 ext4_lblk_t block, int create, int *errp)
724 struct ext4_map_blocks map;
725 struct buffer_head *bh;
728 J_ASSERT(handle != NULL || create == 0);
732 err = ext4_map_blocks(handle, inode, &map,
733 create ? EXT4_GET_BLOCKS_CREATE : 0);
741 bh = sb_getblk(inode->i_sb, map.m_pblk);
746 if (map.m_flags & EXT4_MAP_NEW) {
747 J_ASSERT(create != 0);
748 J_ASSERT(handle != NULL);
751 * Now that we do not always journal data, we should
752 * keep in mind whether this should always journal the
753 * new buffer as metadata. For now, regular file
754 * writes use ext4_get_block instead, so it's not a
758 BUFFER_TRACE(bh, "call get_create_access");
759 fatal = ext4_journal_get_create_access(handle, bh);
760 if (!fatal && !buffer_uptodate(bh)) {
761 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
762 set_buffer_uptodate(bh);
765 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
766 err = ext4_handle_dirty_metadata(handle, inode, bh);
770 BUFFER_TRACE(bh, "not a new buffer");
780 struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
781 ext4_lblk_t block, int create, int *err)
783 struct buffer_head *bh;
785 bh = ext4_getblk(handle, inode, block, create, err);
788 if (buffer_uptodate(bh))
790 ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh);
792 if (buffer_uptodate(bh))
799 static int walk_page_buffers(handle_t *handle,
800 struct buffer_head *head,
804 int (*fn)(handle_t *handle,
805 struct buffer_head *bh))
807 struct buffer_head *bh;
808 unsigned block_start, block_end;
809 unsigned blocksize = head->b_size;
811 struct buffer_head *next;
813 for (bh = head, block_start = 0;
814 ret == 0 && (bh != head || !block_start);
815 block_start = block_end, bh = next) {
816 next = bh->b_this_page;
817 block_end = block_start + blocksize;
818 if (block_end <= from || block_start >= to) {
819 if (partial && !buffer_uptodate(bh))
823 err = (*fn)(handle, bh);
831 * To preserve ordering, it is essential that the hole instantiation and
832 * the data write be encapsulated in a single transaction. We cannot
833 * close off a transaction and start a new one between the ext4_get_block()
834 * and the commit_write(). So doing the jbd2_journal_start at the start of
835 * prepare_write() is the right place.
837 * Also, this function can nest inside ext4_writepage() ->
838 * block_write_full_page(). In that case, we *know* that ext4_writepage()
839 * has generated enough buffer credits to do the whole page. So we won't
840 * block on the journal in that case, which is good, because the caller may
843 * By accident, ext4 can be reentered when a transaction is open via
844 * quota file writes. If we were to commit the transaction while thus
845 * reentered, there can be a deadlock - we would be holding a quota
846 * lock, and the commit would never complete if another thread had a
847 * transaction open and was blocking on the quota lock - a ranking
850 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
851 * will _not_ run commit under these circumstances because handle->h_ref
852 * is elevated. We'll still have enough credits for the tiny quotafile
855 static int do_journal_get_write_access(handle_t *handle,
856 struct buffer_head *bh)
858 int dirty = buffer_dirty(bh);
861 if (!buffer_mapped(bh) || buffer_freed(bh))
864 * __block_write_begin() could have dirtied some buffers. Clean
865 * the dirty bit as jbd2_journal_get_write_access() could complain
866 * otherwise about fs integrity issues. Setting of the dirty bit
867 * by __block_write_begin() isn't a real problem here as we clear
868 * the bit before releasing a page lock and thus writeback cannot
869 * ever write the buffer.
872 clear_buffer_dirty(bh);
873 ret = ext4_journal_get_write_access(handle, bh);
875 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
879 static int ext4_get_block_write(struct inode *inode, sector_t iblock,
880 struct buffer_head *bh_result, int create);
881 static int ext4_write_begin(struct file *file, struct address_space *mapping,
882 loff_t pos, unsigned len, unsigned flags,
883 struct page **pagep, void **fsdata)
885 struct inode *inode = mapping->host;
886 int ret, needed_blocks;
893 trace_ext4_write_begin(inode, pos, len, flags);
895 * Reserve one block more for addition to orphan list in case
896 * we allocate blocks but write fails for some reason
898 needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
899 index = pos >> PAGE_CACHE_SHIFT;
900 from = pos & (PAGE_CACHE_SIZE - 1);
904 handle = ext4_journal_start(inode, needed_blocks);
905 if (IS_ERR(handle)) {
906 ret = PTR_ERR(handle);
910 /* We cannot recurse into the filesystem as the transaction is already
912 flags |= AOP_FLAG_NOFS;
914 page = grab_cache_page_write_begin(mapping, index, flags);
916 ext4_journal_stop(handle);
922 if (ext4_should_dioread_nolock(inode))
923 ret = __block_write_begin(page, pos, len, ext4_get_block_write);
925 ret = __block_write_begin(page, pos, len, ext4_get_block);
927 if (!ret && ext4_should_journal_data(inode)) {
928 ret = walk_page_buffers(handle, page_buffers(page),
929 from, to, NULL, do_journal_get_write_access);
934 page_cache_release(page);
936 * __block_write_begin may have instantiated a few blocks
937 * outside i_size. Trim these off again. Don't need
938 * i_size_read because we hold i_mutex.
940 * Add inode to orphan list in case we crash before
943 if (pos + len > inode->i_size && ext4_can_truncate(inode))
944 ext4_orphan_add(handle, inode);
946 ext4_journal_stop(handle);
947 if (pos + len > inode->i_size) {
948 ext4_truncate_failed_write(inode);
950 * If truncate failed early the inode might
951 * still be on the orphan list; we need to
952 * make sure the inode is removed from the
953 * orphan list in that case.
956 ext4_orphan_del(NULL, inode);
960 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
966 /* For write_end() in data=journal mode */
967 static int write_end_fn(handle_t *handle, struct buffer_head *bh)
969 if (!buffer_mapped(bh) || buffer_freed(bh))
971 set_buffer_uptodate(bh);
972 return ext4_handle_dirty_metadata(handle, NULL, bh);
975 static int ext4_generic_write_end(struct file *file,
976 struct address_space *mapping,
977 loff_t pos, unsigned len, unsigned copied,
978 struct page *page, void *fsdata)
980 int i_size_changed = 0;
981 struct inode *inode = mapping->host;
982 handle_t *handle = ext4_journal_current_handle();
984 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
987 * No need to use i_size_read() here, the i_size
988 * cannot change under us because we hold i_mutex.
990 * But it's important to update i_size while still holding page lock:
991 * page writeout could otherwise come in and zero beyond i_size.
993 if (pos + copied > inode->i_size) {
994 i_size_write(inode, pos + copied);
998 if (pos + copied > EXT4_I(inode)->i_disksize) {
999 /* We need to mark inode dirty even if
1000 * new_i_size is less that inode->i_size
1001 * bu greater than i_disksize.(hint delalloc)
1003 ext4_update_i_disksize(inode, (pos + copied));
1007 page_cache_release(page);
1010 * Don't mark the inode dirty under page lock. First, it unnecessarily
1011 * makes the holding time of page lock longer. Second, it forces lock
1012 * ordering of page lock and transaction start for journaling
1016 ext4_mark_inode_dirty(handle, inode);
1022 * We need to pick up the new inode size which generic_commit_write gave us
1023 * `file' can be NULL - eg, when called from page_symlink().
1025 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1026 * buffers are managed internally.
1028 static int ext4_ordered_write_end(struct file *file,
1029 struct address_space *mapping,
1030 loff_t pos, unsigned len, unsigned copied,
1031 struct page *page, void *fsdata)
1033 handle_t *handle = ext4_journal_current_handle();
1034 struct inode *inode = mapping->host;
1037 trace_ext4_ordered_write_end(inode, pos, len, copied);
1038 ret = ext4_jbd2_file_inode(handle, inode);
1041 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
1044 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1045 /* if we have allocated more blocks and copied
1046 * less. We will have blocks allocated outside
1047 * inode->i_size. So truncate them
1049 ext4_orphan_add(handle, inode);
1054 page_cache_release(page);
1057 ret2 = ext4_journal_stop(handle);
1061 if (pos + len > inode->i_size) {
1062 ext4_truncate_failed_write(inode);
1064 * If truncate failed early the inode might still be
1065 * on the orphan list; we need to make sure the inode
1066 * is removed from the orphan list in that case.
1069 ext4_orphan_del(NULL, inode);
1073 return ret ? ret : copied;
1076 static int ext4_writeback_write_end(struct file *file,
1077 struct address_space *mapping,
1078 loff_t pos, unsigned len, unsigned copied,
1079 struct page *page, void *fsdata)
1081 handle_t *handle = ext4_journal_current_handle();
1082 struct inode *inode = mapping->host;
1085 trace_ext4_writeback_write_end(inode, pos, len, copied);
1086 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
1089 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1090 /* if we have allocated more blocks and copied
1091 * less. We will have blocks allocated outside
1092 * inode->i_size. So truncate them
1094 ext4_orphan_add(handle, inode);
1099 ret2 = ext4_journal_stop(handle);
1103 if (pos + len > inode->i_size) {
1104 ext4_truncate_failed_write(inode);
1106 * If truncate failed early the inode might still be
1107 * on the orphan list; we need to make sure the inode
1108 * is removed from the orphan list in that case.
1111 ext4_orphan_del(NULL, inode);
1114 return ret ? ret : copied;
1117 static int ext4_journalled_write_end(struct file *file,
1118 struct address_space *mapping,
1119 loff_t pos, unsigned len, unsigned copied,
1120 struct page *page, void *fsdata)
1122 handle_t *handle = ext4_journal_current_handle();
1123 struct inode *inode = mapping->host;
1129 trace_ext4_journalled_write_end(inode, pos, len, copied);
1130 from = pos & (PAGE_CACHE_SIZE - 1);
1133 BUG_ON(!ext4_handle_valid(handle));
1136 if (!PageUptodate(page))
1138 page_zero_new_buffers(page, from+copied, to);
1141 ret = walk_page_buffers(handle, page_buffers(page), from,
1142 to, &partial, write_end_fn);
1144 SetPageUptodate(page);
1145 new_i_size = pos + copied;
1146 if (new_i_size > inode->i_size)
1147 i_size_write(inode, pos+copied);
1148 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1149 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1150 if (new_i_size > EXT4_I(inode)->i_disksize) {
1151 ext4_update_i_disksize(inode, new_i_size);
1152 ret2 = ext4_mark_inode_dirty(handle, inode);
1158 page_cache_release(page);
1159 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1160 /* if we have allocated more blocks and copied
1161 * less. We will have blocks allocated outside
1162 * inode->i_size. So truncate them
1164 ext4_orphan_add(handle, inode);
1166 ret2 = ext4_journal_stop(handle);
1169 if (pos + len > inode->i_size) {
1170 ext4_truncate_failed_write(inode);
1172 * If truncate failed early the inode might still be
1173 * on the orphan list; we need to make sure the inode
1174 * is removed from the orphan list in that case.
1177 ext4_orphan_del(NULL, inode);
1180 return ret ? ret : copied;
1184 * Reserve a single cluster located at lblock
1186 static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock)
1189 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1190 struct ext4_inode_info *ei = EXT4_I(inode);
1191 unsigned int md_needed;
1193 ext4_lblk_t save_last_lblock;
1197 * We will charge metadata quota at writeout time; this saves
1198 * us from metadata over-estimation, though we may go over by
1199 * a small amount in the end. Here we just reserve for data.
1201 ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1));
1206 * recalculate the amount of metadata blocks to reserve
1207 * in order to allocate nrblocks
1208 * worse case is one extent per block
1211 spin_lock(&ei->i_block_reservation_lock);
1213 * ext4_calc_metadata_amount() has side effects, which we have
1214 * to be prepared undo if we fail to claim space.
1216 save_len = ei->i_da_metadata_calc_len;
1217 save_last_lblock = ei->i_da_metadata_calc_last_lblock;
1218 md_needed = EXT4_NUM_B2C(sbi,
1219 ext4_calc_metadata_amount(inode, lblock));
1220 trace_ext4_da_reserve_space(inode, md_needed);
1223 * We do still charge estimated metadata to the sb though;
1224 * we cannot afford to run out of free blocks.
1226 if (ext4_claim_free_clusters(sbi, md_needed + 1, 0)) {
1227 ei->i_da_metadata_calc_len = save_len;
1228 ei->i_da_metadata_calc_last_lblock = save_last_lblock;
1229 spin_unlock(&ei->i_block_reservation_lock);
1230 if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
1234 dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
1237 ei->i_reserved_data_blocks++;
1238 ei->i_reserved_meta_blocks += md_needed;
1239 spin_unlock(&ei->i_block_reservation_lock);
1241 return 0; /* success */
1244 static void ext4_da_release_space(struct inode *inode, int to_free)
1246 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1247 struct ext4_inode_info *ei = EXT4_I(inode);
1250 return; /* Nothing to release, exit */
1252 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1254 trace_ext4_da_release_space(inode, to_free);
1255 if (unlikely(to_free > ei->i_reserved_data_blocks)) {
1257 * if there aren't enough reserved blocks, then the
1258 * counter is messed up somewhere. Since this
1259 * function is called from invalidate page, it's
1260 * harmless to return without any action.
1262 ext4_msg(inode->i_sb, KERN_NOTICE, "ext4_da_release_space: "
1263 "ino %lu, to_free %d with only %d reserved "
1264 "data blocks", inode->i_ino, to_free,
1265 ei->i_reserved_data_blocks);
1267 to_free = ei->i_reserved_data_blocks;
1269 ei->i_reserved_data_blocks -= to_free;
1271 if (ei->i_reserved_data_blocks == 0) {
1273 * We can release all of the reserved metadata blocks
1274 * only when we have written all of the delayed
1275 * allocation blocks.
1276 * Note that in case of bigalloc, i_reserved_meta_blocks,
1277 * i_reserved_data_blocks, etc. refer to number of clusters.
1279 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
1280 ei->i_reserved_meta_blocks);
1281 ei->i_reserved_meta_blocks = 0;
1282 ei->i_da_metadata_calc_len = 0;
1285 /* update fs dirty data blocks counter */
1286 percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free);
1288 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1290 dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free));
1293 static void ext4_da_page_release_reservation(struct page *page,
1294 unsigned long offset)
1297 struct buffer_head *head, *bh;
1298 unsigned int curr_off = 0;
1299 struct inode *inode = page->mapping->host;
1300 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1303 head = page_buffers(page);
1306 unsigned int next_off = curr_off + bh->b_size;
1308 if ((offset <= curr_off) && (buffer_delay(bh))) {
1310 clear_buffer_delay(bh);
1311 clear_buffer_da_mapped(bh);
1313 curr_off = next_off;
1314 } while ((bh = bh->b_this_page) != head);
1316 /* If we have released all the blocks belonging to a cluster, then we
1317 * need to release the reserved space for that cluster. */
1318 num_clusters = EXT4_NUM_B2C(sbi, to_release);
1319 while (num_clusters > 0) {
1321 lblk = (page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits)) +
1322 ((num_clusters - 1) << sbi->s_cluster_bits);
1323 if (sbi->s_cluster_ratio == 1 ||
1324 !ext4_find_delalloc_cluster(inode, lblk, 1))
1325 ext4_da_release_space(inode, 1);
1332 * Delayed allocation stuff
1336 * mpage_da_submit_io - walks through extent of pages and try to write
1337 * them with writepage() call back
1339 * @mpd->inode: inode
1340 * @mpd->first_page: first page of the extent
1341 * @mpd->next_page: page after the last page of the extent
1343 * By the time mpage_da_submit_io() is called we expect all blocks
1344 * to be allocated. this may be wrong if allocation failed.
1346 * As pages are already locked by write_cache_pages(), we can't use it
1348 static int mpage_da_submit_io(struct mpage_da_data *mpd,
1349 struct ext4_map_blocks *map)
1351 struct pagevec pvec;
1352 unsigned long index, end;
1353 int ret = 0, err, nr_pages, i;
1354 struct inode *inode = mpd->inode;
1355 struct address_space *mapping = inode->i_mapping;
1356 loff_t size = i_size_read(inode);
1357 unsigned int len, block_start;
1358 struct buffer_head *bh, *page_bufs = NULL;
1359 int journal_data = ext4_should_journal_data(inode);
1360 sector_t pblock = 0, cur_logical = 0;
1361 struct ext4_io_submit io_submit;
1363 BUG_ON(mpd->next_page <= mpd->first_page);
1364 memset(&io_submit, 0, sizeof(io_submit));
1366 * We need to start from the first_page to the next_page - 1
1367 * to make sure we also write the mapped dirty buffer_heads.
1368 * If we look at mpd->b_blocknr we would only be looking
1369 * at the currently mapped buffer_heads.
1371 index = mpd->first_page;
1372 end = mpd->next_page - 1;
1374 pagevec_init(&pvec, 0);
1375 while (index <= end) {
1376 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
1379 for (i = 0; i < nr_pages; i++) {
1380 int commit_write = 0, skip_page = 0;
1381 struct page *page = pvec.pages[i];
1383 index = page->index;
1387 if (index == size >> PAGE_CACHE_SHIFT)
1388 len = size & ~PAGE_CACHE_MASK;
1390 len = PAGE_CACHE_SIZE;
1392 cur_logical = index << (PAGE_CACHE_SHIFT -
1394 pblock = map->m_pblk + (cur_logical -
1399 BUG_ON(!PageLocked(page));
1400 BUG_ON(PageWriteback(page));
1403 * If the page does not have buffers (for
1404 * whatever reason), try to create them using
1405 * __block_write_begin. If this fails,
1406 * skip the page and move on.
1408 if (!page_has_buffers(page)) {
1409 if (__block_write_begin(page, 0, len,
1410 noalloc_get_block_write)) {
1418 bh = page_bufs = page_buffers(page);
1423 if (map && (cur_logical >= map->m_lblk) &&
1424 (cur_logical <= (map->m_lblk +
1425 (map->m_len - 1)))) {
1426 if (buffer_delay(bh)) {
1427 clear_buffer_delay(bh);
1428 bh->b_blocknr = pblock;
1430 if (buffer_da_mapped(bh))
1431 clear_buffer_da_mapped(bh);
1432 if (buffer_unwritten(bh) ||
1434 BUG_ON(bh->b_blocknr != pblock);
1435 if (map->m_flags & EXT4_MAP_UNINIT)
1436 set_buffer_uninit(bh);
1437 clear_buffer_unwritten(bh);
1441 * skip page if block allocation undone and
1444 if (ext4_bh_delay_or_unwritten(NULL, bh))
1446 bh = bh->b_this_page;
1447 block_start += bh->b_size;
1450 } while (bh != page_bufs);
1456 /* mark the buffer_heads as dirty & uptodate */
1457 block_commit_write(page, 0, len);
1459 clear_page_dirty_for_io(page);
1461 * Delalloc doesn't support data journalling,
1462 * but eventually maybe we'll lift this
1465 if (unlikely(journal_data && PageChecked(page)))
1466 err = __ext4_journalled_writepage(page, len);
1467 else if (test_opt(inode->i_sb, MBLK_IO_SUBMIT))
1468 err = ext4_bio_write_page(&io_submit, page,
1470 else if (buffer_uninit(page_bufs)) {
1471 ext4_set_bh_endio(page_bufs, inode);
1472 err = block_write_full_page_endio(page,
1473 noalloc_get_block_write,
1474 mpd->wbc, ext4_end_io_buffer_write);
1476 err = block_write_full_page(page,
1477 noalloc_get_block_write, mpd->wbc);
1480 mpd->pages_written++;
1482 * In error case, we have to continue because
1483 * remaining pages are still locked
1488 pagevec_release(&pvec);
1490 ext4_io_submit(&io_submit);
1494 static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd)
1498 struct pagevec pvec;
1499 struct inode *inode = mpd->inode;
1500 struct address_space *mapping = inode->i_mapping;
1502 index = mpd->first_page;
1503 end = mpd->next_page - 1;
1504 while (index <= end) {
1505 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
1508 for (i = 0; i < nr_pages; i++) {
1509 struct page *page = pvec.pages[i];
1510 if (page->index > end)
1512 BUG_ON(!PageLocked(page));
1513 BUG_ON(PageWriteback(page));
1514 block_invalidatepage(page, 0);
1515 ClearPageUptodate(page);
1518 index = pvec.pages[nr_pages - 1]->index + 1;
1519 pagevec_release(&pvec);
1524 static void ext4_print_free_blocks(struct inode *inode)
1526 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1527 struct super_block *sb = inode->i_sb;
1529 ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld",
1530 EXT4_C2B(EXT4_SB(inode->i_sb),
1531 ext4_count_free_clusters(inode->i_sb)));
1532 ext4_msg(sb, KERN_CRIT, "Free/Dirty block details");
1533 ext4_msg(sb, KERN_CRIT, "free_blocks=%lld",
1534 (long long) EXT4_C2B(EXT4_SB(inode->i_sb),
1535 percpu_counter_sum(&sbi->s_freeclusters_counter)));
1536 ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld",
1537 (long long) EXT4_C2B(EXT4_SB(inode->i_sb),
1538 percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
1539 ext4_msg(sb, KERN_CRIT, "Block reservation details");
1540 ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u",
1541 EXT4_I(inode)->i_reserved_data_blocks);
1542 ext4_msg(sb, KERN_CRIT, "i_reserved_meta_blocks=%u",
1543 EXT4_I(inode)->i_reserved_meta_blocks);
1548 * mpage_da_map_and_submit - go through given space, map them
1549 * if necessary, and then submit them for I/O
1551 * @mpd - bh describing space
1553 * The function skips space we know is already mapped to disk blocks.
1556 static void mpage_da_map_and_submit(struct mpage_da_data *mpd)
1558 int err, blks, get_blocks_flags;
1559 struct ext4_map_blocks map, *mapp = NULL;
1560 sector_t next = mpd->b_blocknr;
1561 unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits;
1562 loff_t disksize = EXT4_I(mpd->inode)->i_disksize;
1563 handle_t *handle = NULL;
1566 * If the blocks are mapped already, or we couldn't accumulate
1567 * any blocks, then proceed immediately to the submission stage.
1569 if ((mpd->b_size == 0) ||
1570 ((mpd->b_state & (1 << BH_Mapped)) &&
1571 !(mpd->b_state & (1 << BH_Delay)) &&
1572 !(mpd->b_state & (1 << BH_Unwritten))))
1575 handle = ext4_journal_current_handle();
1579 * Call ext4_map_blocks() to allocate any delayed allocation
1580 * blocks, or to convert an uninitialized extent to be
1581 * initialized (in the case where we have written into
1582 * one or more preallocated blocks).
1584 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
1585 * indicate that we are on the delayed allocation path. This
1586 * affects functions in many different parts of the allocation
1587 * call path. This flag exists primarily because we don't
1588 * want to change *many* call functions, so ext4_map_blocks()
1589 * will set the EXT4_STATE_DELALLOC_RESERVED flag once the
1590 * inode's allocation semaphore is taken.
1592 * If the blocks in questions were delalloc blocks, set
1593 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
1594 * variables are updated after the blocks have been allocated.
1597 map.m_len = max_blocks;
1598 get_blocks_flags = EXT4_GET_BLOCKS_CREATE;
1599 if (ext4_should_dioread_nolock(mpd->inode))
1600 get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
1601 if (mpd->b_state & (1 << BH_Delay))
1602 get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
1604 blks = ext4_map_blocks(handle, mpd->inode, &map, get_blocks_flags);
1606 struct super_block *sb = mpd->inode->i_sb;
1610 * If get block returns EAGAIN or ENOSPC and there
1611 * appears to be free blocks we will just let
1612 * mpage_da_submit_io() unlock all of the pages.
1617 if (err == -ENOSPC && ext4_count_free_clusters(sb)) {
1623 * get block failure will cause us to loop in
1624 * writepages, because a_ops->writepage won't be able
1625 * to make progress. The page will be redirtied by
1626 * writepage and writepages will again try to write
1629 if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) {
1630 ext4_msg(sb, KERN_CRIT,
1631 "delayed block allocation failed for inode %lu "
1632 "at logical offset %llu with max blocks %zd "
1633 "with error %d", mpd->inode->i_ino,
1634 (unsigned long long) next,
1635 mpd->b_size >> mpd->inode->i_blkbits, err);
1636 ext4_msg(sb, KERN_CRIT,
1637 "This should not happen!! Data will be lost\n");
1639 ext4_print_free_blocks(mpd->inode);
1641 /* invalidate all the pages */
1642 ext4_da_block_invalidatepages(mpd);
1644 /* Mark this page range as having been completed */
1651 if (map.m_flags & EXT4_MAP_NEW) {
1652 struct block_device *bdev = mpd->inode->i_sb->s_bdev;
1655 for (i = 0; i < map.m_len; i++)
1656 unmap_underlying_metadata(bdev, map.m_pblk + i);
1658 if (ext4_should_order_data(mpd->inode)) {
1659 err = ext4_jbd2_file_inode(handle, mpd->inode);
1661 /* Only if the journal is aborted */
1669 * Update on-disk size along with block allocation.
1671 disksize = ((loff_t) next + blks) << mpd->inode->i_blkbits;
1672 if (disksize > i_size_read(mpd->inode))
1673 disksize = i_size_read(mpd->inode);
1674 if (disksize > EXT4_I(mpd->inode)->i_disksize) {
1675 ext4_update_i_disksize(mpd->inode, disksize);
1676 err = ext4_mark_inode_dirty(handle, mpd->inode);
1678 ext4_error(mpd->inode->i_sb,
1679 "Failed to mark inode %lu dirty",
1684 mpage_da_submit_io(mpd, mapp);
1688 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
1689 (1 << BH_Delay) | (1 << BH_Unwritten))
1692 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
1694 * @mpd->lbh - extent of blocks
1695 * @logical - logical number of the block in the file
1696 * @bh - bh of the block (used to access block's state)
1698 * the function is used to collect contig. blocks in same state
1700 static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
1701 sector_t logical, size_t b_size,
1702 unsigned long b_state)
1705 int nrblocks = mpd->b_size >> mpd->inode->i_blkbits;
1708 * XXX Don't go larger than mballoc is willing to allocate
1709 * This is a stopgap solution. We eventually need to fold
1710 * mpage_da_submit_io() into this function and then call
1711 * ext4_map_blocks() multiple times in a loop
1713 if (nrblocks >= 8*1024*1024/mpd->inode->i_sb->s_blocksize)
1716 /* check if thereserved journal credits might overflow */
1717 if (!(ext4_test_inode_flag(mpd->inode, EXT4_INODE_EXTENTS))) {
1718 if (nrblocks >= EXT4_MAX_TRANS_DATA) {
1720 * With non-extent format we are limited by the journal
1721 * credit available. Total credit needed to insert
1722 * nrblocks contiguous blocks is dependent on the
1723 * nrblocks. So limit nrblocks.
1726 } else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) >
1727 EXT4_MAX_TRANS_DATA) {
1729 * Adding the new buffer_head would make it cross the
1730 * allowed limit for which we have journal credit
1731 * reserved. So limit the new bh->b_size
1733 b_size = (EXT4_MAX_TRANS_DATA - nrblocks) <<
1734 mpd->inode->i_blkbits;
1735 /* we will do mpage_da_submit_io in the next loop */
1739 * First block in the extent
1741 if (mpd->b_size == 0) {
1742 mpd->b_blocknr = logical;
1743 mpd->b_size = b_size;
1744 mpd->b_state = b_state & BH_FLAGS;
1748 next = mpd->b_blocknr + nrblocks;
1750 * Can we merge the block to our big extent?
1752 if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
1753 mpd->b_size += b_size;
1759 * We couldn't merge the block to our extent, so we
1760 * need to flush current extent and start new one
1762 mpage_da_map_and_submit(mpd);
1766 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
1768 return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
1772 * This function is grabs code from the very beginning of
1773 * ext4_map_blocks, but assumes that the caller is from delayed write
1774 * time. This function looks up the requested blocks and sets the
1775 * buffer delay bit under the protection of i_data_sem.
1777 static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
1778 struct ext4_map_blocks *map,
1779 struct buffer_head *bh)
1782 sector_t invalid_block = ~((sector_t) 0xffff);
1784 if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
1788 ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u,"
1789 "logical block %lu\n", inode->i_ino, map->m_len,
1790 (unsigned long) map->m_lblk);
1792 * Try to see if we can get the block without requesting a new
1793 * file system block.
1795 down_read((&EXT4_I(inode)->i_data_sem));
1796 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
1797 retval = ext4_ext_map_blocks(NULL, inode, map, 0);
1799 retval = ext4_ind_map_blocks(NULL, inode, map, 0);
1803 * XXX: __block_prepare_write() unmaps passed block,
1806 /* If the block was allocated from previously allocated cluster,
1807 * then we dont need to reserve it again. */
1808 if (!(map->m_flags & EXT4_MAP_FROM_CLUSTER)) {
1809 retval = ext4_da_reserve_space(inode, iblock);
1811 /* not enough space to reserve */
1815 /* Clear EXT4_MAP_FROM_CLUSTER flag since its purpose is served
1816 * and it should not appear on the bh->b_state.
1818 map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
1820 map_bh(bh, inode->i_sb, invalid_block);
1822 set_buffer_delay(bh);
1826 up_read((&EXT4_I(inode)->i_data_sem));
1832 * This is a special get_blocks_t callback which is used by
1833 * ext4_da_write_begin(). It will either return mapped block or
1834 * reserve space for a single block.
1836 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
1837 * We also have b_blocknr = -1 and b_bdev initialized properly
1839 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
1840 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
1841 * initialized properly.
1843 static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
1844 struct buffer_head *bh, int create)
1846 struct ext4_map_blocks map;
1849 BUG_ON(create == 0);
1850 BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
1852 map.m_lblk = iblock;
1856 * first, we need to know whether the block is allocated already
1857 * preallocated blocks are unmapped but should treated
1858 * the same as allocated blocks.
1860 ret = ext4_da_map_blocks(inode, iblock, &map, bh);
1864 map_bh(bh, inode->i_sb, map.m_pblk);
1865 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
1867 if (buffer_unwritten(bh)) {
1868 /* A delayed write to unwritten bh should be marked
1869 * new and mapped. Mapped ensures that we don't do
1870 * get_block multiple times when we write to the same
1871 * offset and new ensures that we do proper zero out
1872 * for partial write.
1875 set_buffer_mapped(bh);
1881 * This function is used as a standard get_block_t calback function
1882 * when there is no desire to allocate any blocks. It is used as a
1883 * callback function for block_write_begin() and block_write_full_page().
1884 * These functions should only try to map a single block at a time.
1886 * Since this function doesn't do block allocations even if the caller
1887 * requests it by passing in create=1, it is critically important that
1888 * any caller checks to make sure that any buffer heads are returned
1889 * by this function are either all already mapped or marked for
1890 * delayed allocation before calling block_write_full_page(). Otherwise,
1891 * b_blocknr could be left unitialized, and the page write functions will
1892 * be taken by surprise.
1894 static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
1895 struct buffer_head *bh_result, int create)
1897 BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
1898 return _ext4_get_block(inode, iblock, bh_result, 0);
1901 static int bget_one(handle_t *handle, struct buffer_head *bh)
1907 static int bput_one(handle_t *handle, struct buffer_head *bh)
1913 static int __ext4_journalled_writepage(struct page *page,
1916 struct address_space *mapping = page->mapping;
1917 struct inode *inode = mapping->host;
1918 struct buffer_head *page_bufs;
1919 handle_t *handle = NULL;
1923 ClearPageChecked(page);
1924 page_bufs = page_buffers(page);
1926 walk_page_buffers(handle, page_bufs, 0, len, NULL, bget_one);
1927 /* As soon as we unlock the page, it can go away, but we have
1928 * references to buffers so we are safe */
1931 handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
1932 if (IS_ERR(handle)) {
1933 ret = PTR_ERR(handle);
1937 BUG_ON(!ext4_handle_valid(handle));
1939 ret = walk_page_buffers(handle, page_bufs, 0, len, NULL,
1940 do_journal_get_write_access);
1942 err = walk_page_buffers(handle, page_bufs, 0, len, NULL,
1946 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1947 err = ext4_journal_stop(handle);
1951 walk_page_buffers(handle, page_bufs, 0, len, NULL, bput_one);
1952 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1958 * Note that we don't need to start a transaction unless we're journaling data
1959 * because we should have holes filled from ext4_page_mkwrite(). We even don't
1960 * need to file the inode to the transaction's list in ordered mode because if
1961 * we are writing back data added by write(), the inode is already there and if
1962 * we are writing back data modified via mmap(), no one guarantees in which
1963 * transaction the data will hit the disk. In case we are journaling data, we
1964 * cannot start transaction directly because transaction start ranks above page
1965 * lock so we have to do some magic.
1967 * This function can get called via...
1968 * - ext4_da_writepages after taking page lock (have journal handle)
1969 * - journal_submit_inode_data_buffers (no journal handle)
1970 * - shrink_page_list via pdflush (no journal handle)
1971 * - grab_page_cache when doing write_begin (have journal handle)
1973 * We don't do any block allocation in this function. If we have page with
1974 * multiple blocks we need to write those buffer_heads that are mapped. This
1975 * is important for mmaped based write. So if we do with blocksize 1K
1976 * truncate(f, 1024);
1977 * a = mmap(f, 0, 4096);
1979 * truncate(f, 4096);
1980 * we have in the page first buffer_head mapped via page_mkwrite call back
1981 * but other buffer_heads would be unmapped but dirty (dirty done via the
1982 * do_wp_page). So writepage should write the first block. If we modify
1983 * the mmap area beyond 1024 we will again get a page_fault and the
1984 * page_mkwrite callback will do the block allocation and mark the
1985 * buffer_heads mapped.
1987 * We redirty the page if we have any buffer_heads that is either delay or
1988 * unwritten in the page.
1990 * We can get recursively called as show below.
1992 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1995 * But since we don't do any block allocation we should not deadlock.
1996 * Page also have the dirty flag cleared so we don't get recurive page_lock.
1998 static int ext4_writepage(struct page *page,
1999 struct writeback_control *wbc)
2001 int ret = 0, commit_write = 0;
2004 struct buffer_head *page_bufs = NULL;
2005 struct inode *inode = page->mapping->host;
2007 trace_ext4_writepage(page);
2008 size = i_size_read(inode);
2009 if (page->index == size >> PAGE_CACHE_SHIFT)
2010 len = size & ~PAGE_CACHE_MASK;
2012 len = PAGE_CACHE_SIZE;
2015 * If the page does not have buffers (for whatever reason),
2016 * try to create them using __block_write_begin. If this
2017 * fails, redirty the page and move on.
2019 if (!page_has_buffers(page)) {
2020 if (__block_write_begin(page, 0, len,
2021 noalloc_get_block_write)) {
2023 redirty_page_for_writepage(wbc, page);
2029 page_bufs = page_buffers(page);
2030 if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
2031 ext4_bh_delay_or_unwritten)) {
2033 * We don't want to do block allocation, so redirty
2034 * the page and return. We may reach here when we do
2035 * a journal commit via journal_submit_inode_data_buffers.
2036 * We can also reach here via shrink_page_list but it
2037 * should never be for direct reclaim so warn if that
2040 WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) ==
2045 /* now mark the buffer_heads as dirty and uptodate */
2046 block_commit_write(page, 0, len);
2048 if (PageChecked(page) && ext4_should_journal_data(inode))
2050 * It's mmapped pagecache. Add buffers and journal it. There
2051 * doesn't seem much point in redirtying the page here.
2053 return __ext4_journalled_writepage(page, len);
2055 if (buffer_uninit(page_bufs)) {
2056 ext4_set_bh_endio(page_bufs, inode);
2057 ret = block_write_full_page_endio(page, noalloc_get_block_write,
2058 wbc, ext4_end_io_buffer_write);
2060 ret = block_write_full_page(page, noalloc_get_block_write,
2067 * This is called via ext4_da_writepages() to
2068 * calculate the total number of credits to reserve to fit
2069 * a single extent allocation into a single transaction,
2070 * ext4_da_writpeages() will loop calling this before
2071 * the block allocation.
2074 static int ext4_da_writepages_trans_blocks(struct inode *inode)
2076 int max_blocks = EXT4_I(inode)->i_reserved_data_blocks;
2079 * With non-extent format the journal credit needed to
2080 * insert nrblocks contiguous block is dependent on
2081 * number of contiguous block. So we will limit
2082 * number of contiguous block to a sane value
2084 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) &&
2085 (max_blocks > EXT4_MAX_TRANS_DATA))
2086 max_blocks = EXT4_MAX_TRANS_DATA;
2088 return ext4_chunk_trans_blocks(inode, max_blocks);
2092 * write_cache_pages_da - walk the list of dirty pages of the given
2093 * address space and accumulate pages that need writing, and call
2094 * mpage_da_map_and_submit to map a single contiguous memory region
2095 * and then write them.
2097 static int write_cache_pages_da(struct address_space *mapping,
2098 struct writeback_control *wbc,
2099 struct mpage_da_data *mpd,
2100 pgoff_t *done_index)
2102 struct buffer_head *bh, *head;
2103 struct inode *inode = mapping->host;
2104 struct pagevec pvec;
2105 unsigned int nr_pages;
2108 long nr_to_write = wbc->nr_to_write;
2109 int i, tag, ret = 0;
2111 memset(mpd, 0, sizeof(struct mpage_da_data));
2114 pagevec_init(&pvec, 0);
2115 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2116 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2118 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2119 tag = PAGECACHE_TAG_TOWRITE;
2121 tag = PAGECACHE_TAG_DIRTY;
2123 *done_index = index;
2124 while (index <= end) {
2125 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
2126 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
2130 for (i = 0; i < nr_pages; i++) {
2131 struct page *page = pvec.pages[i];
2134 * At this point, the page may be truncated or
2135 * invalidated (changing page->mapping to NULL), or
2136 * even swizzled back from swapper_space to tmpfs file
2137 * mapping. However, page->index will not change
2138 * because we have a reference on the page.
2140 if (page->index > end)
2143 *done_index = page->index + 1;
2146 * If we can't merge this page, and we have
2147 * accumulated an contiguous region, write it
2149 if ((mpd->next_page != page->index) &&
2150 (mpd->next_page != mpd->first_page)) {
2151 mpage_da_map_and_submit(mpd);
2152 goto ret_extent_tail;
2158 * If the page is no longer dirty, or its
2159 * mapping no longer corresponds to inode we
2160 * are writing (which means it has been
2161 * truncated or invalidated), or the page is
2162 * already under writeback and we are not
2163 * doing a data integrity writeback, skip the page
2165 if (!PageDirty(page) ||
2166 (PageWriteback(page) &&
2167 (wbc->sync_mode == WB_SYNC_NONE)) ||
2168 unlikely(page->mapping != mapping)) {
2173 wait_on_page_writeback(page);
2174 BUG_ON(PageWriteback(page));
2176 if (mpd->next_page != page->index)
2177 mpd->first_page = page->index;
2178 mpd->next_page = page->index + 1;
2179 logical = (sector_t) page->index <<
2180 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2182 if (!page_has_buffers(page)) {
2183 mpage_add_bh_to_extent(mpd, logical,
2185 (1 << BH_Dirty) | (1 << BH_Uptodate));
2187 goto ret_extent_tail;
2190 * Page with regular buffer heads,
2191 * just add all dirty ones
2193 head = page_buffers(page);
2196 BUG_ON(buffer_locked(bh));
2198 * We need to try to allocate
2199 * unmapped blocks in the same page.
2200 * Otherwise we won't make progress
2201 * with the page in ext4_writepage
2203 if (ext4_bh_delay_or_unwritten(NULL, bh)) {
2204 mpage_add_bh_to_extent(mpd, logical,
2208 goto ret_extent_tail;
2209 } else if (buffer_dirty(bh) && (buffer_mapped(bh))) {
2211 * mapped dirty buffer. We need
2212 * to update the b_state
2213 * because we look at b_state
2214 * in mpage_da_map_blocks. We
2215 * don't update b_size because
2216 * if we find an unmapped
2217 * buffer_head later we need to
2218 * use the b_state flag of that
2221 if (mpd->b_size == 0)
2222 mpd->b_state = bh->b_state & BH_FLAGS;
2225 } while ((bh = bh->b_this_page) != head);
2228 if (nr_to_write > 0) {
2230 if (nr_to_write == 0 &&
2231 wbc->sync_mode == WB_SYNC_NONE)
2233 * We stop writing back only if we are
2234 * not doing integrity sync. In case of
2235 * integrity sync we have to keep going
2236 * because someone may be concurrently
2237 * dirtying pages, and we might have
2238 * synced a lot of newly appeared dirty
2239 * pages, but have not synced all of the
2245 pagevec_release(&pvec);
2250 ret = MPAGE_DA_EXTENT_TAIL;
2252 pagevec_release(&pvec);
2258 static int ext4_da_writepages(struct address_space *mapping,
2259 struct writeback_control *wbc)
2262 int range_whole = 0;
2263 handle_t *handle = NULL;
2264 struct mpage_da_data mpd;
2265 struct inode *inode = mapping->host;
2266 int pages_written = 0;
2267 unsigned int max_pages;
2268 int range_cyclic, cycled = 1, io_done = 0;
2269 int needed_blocks, ret = 0;
2270 long desired_nr_to_write, nr_to_writebump = 0;
2271 loff_t range_start = wbc->range_start;
2272 struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
2273 pgoff_t done_index = 0;
2275 struct blk_plug plug;
2277 trace_ext4_da_writepages(inode, wbc);
2280 * No pages to write? This is mainly a kludge to avoid starting
2281 * a transaction for special inodes like journal inode on last iput()
2282 * because that could violate lock ordering on umount
2284 if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2288 * If the filesystem has aborted, it is read-only, so return
2289 * right away instead of dumping stack traces later on that
2290 * will obscure the real source of the problem. We test
2291 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2292 * the latter could be true if the filesystem is mounted
2293 * read-only, and in that case, ext4_da_writepages should
2294 * *never* be called, so if that ever happens, we would want
2297 if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED))
2300 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2303 range_cyclic = wbc->range_cyclic;
2304 if (wbc->range_cyclic) {
2305 index = mapping->writeback_index;
2308 wbc->range_start = index << PAGE_CACHE_SHIFT;
2309 wbc->range_end = LLONG_MAX;
2310 wbc->range_cyclic = 0;
2313 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2314 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2318 * This works around two forms of stupidity. The first is in
2319 * the writeback code, which caps the maximum number of pages
2320 * written to be 1024 pages. This is wrong on multiple
2321 * levels; different architectues have a different page size,
2322 * which changes the maximum amount of data which gets
2323 * written. Secondly, 4 megabytes is way too small. XFS
2324 * forces this value to be 16 megabytes by multiplying
2325 * nr_to_write parameter by four, and then relies on its
2326 * allocator to allocate larger extents to make them
2327 * contiguous. Unfortunately this brings us to the second
2328 * stupidity, which is that ext4's mballoc code only allocates
2329 * at most 2048 blocks. So we force contiguous writes up to
2330 * the number of dirty blocks in the inode, or
2331 * sbi->max_writeback_mb_bump whichever is smaller.
2333 max_pages = sbi->s_max_writeback_mb_bump << (20 - PAGE_CACHE_SHIFT);
2334 if (!range_cyclic && range_whole) {
2335 if (wbc->nr_to_write == LONG_MAX)
2336 desired_nr_to_write = wbc->nr_to_write;
2338 desired_nr_to_write = wbc->nr_to_write * 8;
2340 desired_nr_to_write = ext4_num_dirty_pages(inode, index,
2342 if (desired_nr_to_write > max_pages)
2343 desired_nr_to_write = max_pages;
2345 if (wbc->nr_to_write < desired_nr_to_write) {
2346 nr_to_writebump = desired_nr_to_write - wbc->nr_to_write;
2347 wbc->nr_to_write = desired_nr_to_write;
2351 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2352 tag_pages_for_writeback(mapping, index, end);
2354 blk_start_plug(&plug);
2355 while (!ret && wbc->nr_to_write > 0) {
2358 * we insert one extent at a time. So we need
2359 * credit needed for single extent allocation.
2360 * journalled mode is currently not supported
2363 BUG_ON(ext4_should_journal_data(inode));
2364 needed_blocks = ext4_da_writepages_trans_blocks(inode);
2366 /* start a new transaction*/
2367 handle = ext4_journal_start(inode, needed_blocks);
2368 if (IS_ERR(handle)) {
2369 ret = PTR_ERR(handle);
2370 ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
2371 "%ld pages, ino %lu; err %d", __func__,
2372 wbc->nr_to_write, inode->i_ino, ret);
2373 blk_finish_plug(&plug);
2374 goto out_writepages;
2378 * Now call write_cache_pages_da() to find the next
2379 * contiguous region of logical blocks that need
2380 * blocks to be allocated by ext4 and submit them.
2382 ret = write_cache_pages_da(mapping, wbc, &mpd, &done_index);
2384 * If we have a contiguous extent of pages and we
2385 * haven't done the I/O yet, map the blocks and submit
2388 if (!mpd.io_done && mpd.next_page != mpd.first_page) {
2389 mpage_da_map_and_submit(&mpd);
2390 ret = MPAGE_DA_EXTENT_TAIL;
2392 trace_ext4_da_write_pages(inode, &mpd);
2393 wbc->nr_to_write -= mpd.pages_written;
2395 ext4_journal_stop(handle);
2397 if ((mpd.retval == -ENOSPC) && sbi->s_journal) {
2398 /* commit the transaction which would
2399 * free blocks released in the transaction
2402 jbd2_journal_force_commit_nested(sbi->s_journal);
2404 } else if (ret == MPAGE_DA_EXTENT_TAIL) {
2406 * Got one extent now try with rest of the pages.
2407 * If mpd.retval is set -EIO, journal is aborted.
2408 * So we don't need to write any more.
2410 pages_written += mpd.pages_written;
2413 } else if (wbc->nr_to_write)
2415 * There is no more writeout needed
2416 * or we requested for a noblocking writeout
2417 * and we found the device congested
2421 blk_finish_plug(&plug);
2422 if (!io_done && !cycled) {
2425 wbc->range_start = index << PAGE_CACHE_SHIFT;
2426 wbc->range_end = mapping->writeback_index - 1;
2431 wbc->range_cyclic = range_cyclic;
2432 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2434 * set the writeback_index so that range_cyclic
2435 * mode will write it back later
2437 mapping->writeback_index = done_index;
2440 wbc->nr_to_write -= nr_to_writebump;
2441 wbc->range_start = range_start;
2442 trace_ext4_da_writepages_result(inode, wbc, ret, pages_written);
2446 #define FALL_BACK_TO_NONDELALLOC 1
2447 static int ext4_nonda_switch(struct super_block *sb)
2449 s64 free_blocks, dirty_blocks;
2450 struct ext4_sb_info *sbi = EXT4_SB(sb);
2453 * switch to non delalloc mode if we are running low
2454 * on free block. The free block accounting via percpu
2455 * counters can get slightly wrong with percpu_counter_batch getting
2456 * accumulated on each CPU without updating global counters
2457 * Delalloc need an accurate free block accounting. So switch
2458 * to non delalloc when we are near to error range.
2460 free_blocks = EXT4_C2B(sbi,
2461 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
2462 dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyclusters_counter);
2463 if (2 * free_blocks < 3 * dirty_blocks ||
2464 free_blocks < (dirty_blocks + EXT4_FREECLUSTERS_WATERMARK)) {
2466 * free block count is less than 150% of dirty blocks
2467 * or free blocks is less than watermark
2472 * Even if we don't switch but are nearing capacity,
2473 * start pushing delalloc when 1/2 of free blocks are dirty.
2475 if (free_blocks < 2 * dirty_blocks)
2476 writeback_inodes_sb_if_idle(sb, WB_REASON_FS_FREE_SPACE);
2481 static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
2482 loff_t pos, unsigned len, unsigned flags,
2483 struct page **pagep, void **fsdata)
2485 int ret, retries = 0;
2488 struct inode *inode = mapping->host;
2491 index = pos >> PAGE_CACHE_SHIFT;
2493 if (ext4_nonda_switch(inode->i_sb)) {
2494 *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
2495 return ext4_write_begin(file, mapping, pos,
2496 len, flags, pagep, fsdata);
2498 *fsdata = (void *)0;
2499 trace_ext4_da_write_begin(inode, pos, len, flags);
2502 * With delayed allocation, we don't log the i_disksize update
2503 * if there is delayed block allocation. But we still need
2504 * to journalling the i_disksize update if writes to the end
2505 * of file which has an already mapped buffer.
2507 handle = ext4_journal_start(inode, 1);
2508 if (IS_ERR(handle)) {
2509 ret = PTR_ERR(handle);
2512 /* We cannot recurse into the filesystem as the transaction is already
2514 flags |= AOP_FLAG_NOFS;
2516 page = grab_cache_page_write_begin(mapping, index, flags);
2518 ext4_journal_stop(handle);
2524 ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep);
2527 ext4_journal_stop(handle);
2528 page_cache_release(page);
2530 * block_write_begin may have instantiated a few blocks
2531 * outside i_size. Trim these off again. Don't need
2532 * i_size_read because we hold i_mutex.
2534 if (pos + len > inode->i_size)
2535 ext4_truncate_failed_write(inode);
2538 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
2545 * Check if we should update i_disksize
2546 * when write to the end of file but not require block allocation
2548 static int ext4_da_should_update_i_disksize(struct page *page,
2549 unsigned long offset)
2551 struct buffer_head *bh;
2552 struct inode *inode = page->mapping->host;
2556 bh = page_buffers(page);
2557 idx = offset >> inode->i_blkbits;
2559 for (i = 0; i < idx; i++)
2560 bh = bh->b_this_page;
2562 if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
2567 static int ext4_da_write_end(struct file *file,
2568 struct address_space *mapping,
2569 loff_t pos, unsigned len, unsigned copied,
2570 struct page *page, void *fsdata)
2572 struct inode *inode = mapping->host;
2574 handle_t *handle = ext4_journal_current_handle();
2576 unsigned long start, end;
2577 int write_mode = (int)(unsigned long)fsdata;
2579 if (write_mode == FALL_BACK_TO_NONDELALLOC) {
2580 switch (ext4_inode_journal_mode(inode)) {
2581 case EXT4_INODE_ORDERED_DATA_MODE:
2582 return ext4_ordered_write_end(file, mapping, pos,
2583 len, copied, page, fsdata);
2584 case EXT4_INODE_WRITEBACK_DATA_MODE:
2585 return ext4_writeback_write_end(file, mapping, pos,
2586 len, copied, page, fsdata);
2592 trace_ext4_da_write_end(inode, pos, len, copied);
2593 start = pos & (PAGE_CACHE_SIZE - 1);
2594 end = start + copied - 1;
2597 * generic_write_end() will run mark_inode_dirty() if i_size
2598 * changes. So let's piggyback the i_disksize mark_inode_dirty
2602 new_i_size = pos + copied;
2603 if (copied && new_i_size > EXT4_I(inode)->i_disksize) {
2604 if (ext4_da_should_update_i_disksize(page, end)) {
2605 down_write(&EXT4_I(inode)->i_data_sem);
2606 if (new_i_size > EXT4_I(inode)->i_disksize) {
2608 * Updating i_disksize when extending file
2609 * without needing block allocation
2611 if (ext4_should_order_data(inode))
2612 ret = ext4_jbd2_file_inode(handle,
2615 EXT4_I(inode)->i_disksize = new_i_size;
2617 up_write(&EXT4_I(inode)->i_data_sem);
2618 /* We need to mark inode dirty even if
2619 * new_i_size is less that inode->i_size
2620 * bu greater than i_disksize.(hint delalloc)
2622 ext4_mark_inode_dirty(handle, inode);
2625 ret2 = generic_write_end(file, mapping, pos, len, copied,
2630 ret2 = ext4_journal_stop(handle);
2634 return ret ? ret : copied;
2637 static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
2640 * Drop reserved blocks
2642 BUG_ON(!PageLocked(page));
2643 if (!page_has_buffers(page))
2646 ext4_da_page_release_reservation(page, offset);
2649 ext4_invalidatepage(page, offset);
2655 * Force all delayed allocation blocks to be allocated for a given inode.
2657 int ext4_alloc_da_blocks(struct inode *inode)
2659 trace_ext4_alloc_da_blocks(inode);
2661 if (!EXT4_I(inode)->i_reserved_data_blocks &&
2662 !EXT4_I(inode)->i_reserved_meta_blocks)
2666 * We do something simple for now. The filemap_flush() will
2667 * also start triggering a write of the data blocks, which is
2668 * not strictly speaking necessary (and for users of
2669 * laptop_mode, not even desirable). However, to do otherwise
2670 * would require replicating code paths in:
2672 * ext4_da_writepages() ->
2673 * write_cache_pages() ---> (via passed in callback function)
2674 * __mpage_da_writepage() -->
2675 * mpage_add_bh_to_extent()
2676 * mpage_da_map_blocks()
2678 * The problem is that write_cache_pages(), located in
2679 * mm/page-writeback.c, marks pages clean in preparation for
2680 * doing I/O, which is not desirable if we're not planning on
2683 * We could call write_cache_pages(), and then redirty all of
2684 * the pages by calling redirty_page_for_writepage() but that
2685 * would be ugly in the extreme. So instead we would need to
2686 * replicate parts of the code in the above functions,
2687 * simplifying them because we wouldn't actually intend to
2688 * write out the pages, but rather only collect contiguous
2689 * logical block extents, call the multi-block allocator, and
2690 * then update the buffer heads with the block allocations.
2692 * For now, though, we'll cheat by calling filemap_flush(),
2693 * which will map the blocks, and start the I/O, but not
2694 * actually wait for the I/O to complete.
2696 return filemap_flush(inode->i_mapping);
2700 * bmap() is special. It gets used by applications such as lilo and by
2701 * the swapper to find the on-disk block of a specific piece of data.
2703 * Naturally, this is dangerous if the block concerned is still in the
2704 * journal. If somebody makes a swapfile on an ext4 data-journaling
2705 * filesystem and enables swap, then they may get a nasty shock when the
2706 * data getting swapped to that swapfile suddenly gets overwritten by
2707 * the original zero's written out previously to the journal and
2708 * awaiting writeback in the kernel's buffer cache.
2710 * So, if we see any bmap calls here on a modified, data-journaled file,
2711 * take extra steps to flush any blocks which might be in the cache.
2713 static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
2715 struct inode *inode = mapping->host;
2719 if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
2720 test_opt(inode->i_sb, DELALLOC)) {
2722 * With delalloc we want to sync the file
2723 * so that we can make sure we allocate
2726 filemap_write_and_wait(mapping);
2729 if (EXT4_JOURNAL(inode) &&
2730 ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {
2732 * This is a REALLY heavyweight approach, but the use of
2733 * bmap on dirty files is expected to be extremely rare:
2734 * only if we run lilo or swapon on a freshly made file
2735 * do we expect this to happen.
2737 * (bmap requires CAP_SYS_RAWIO so this does not
2738 * represent an unprivileged user DOS attack --- we'd be
2739 * in trouble if mortal users could trigger this path at
2742 * NB. EXT4_STATE_JDATA is not set on files other than
2743 * regular files. If somebody wants to bmap a directory
2744 * or symlink and gets confused because the buffer
2745 * hasn't yet been flushed to disk, they deserve
2746 * everything they get.
2749 ext4_clear_inode_state(inode, EXT4_STATE_JDATA);
2750 journal = EXT4_JOURNAL(inode);
2751 jbd2_journal_lock_updates(journal);
2752 err = jbd2_journal_flush(journal);
2753 jbd2_journal_unlock_updates(journal);
2759 return generic_block_bmap(mapping, block, ext4_get_block);
2762 static int ext4_readpage(struct file *file, struct page *page)
2764 trace_ext4_readpage(page);
2765 return mpage_readpage(page, ext4_get_block);
2769 ext4_readpages(struct file *file, struct address_space *mapping,
2770 struct list_head *pages, unsigned nr_pages)
2772 return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
2775 static void ext4_invalidatepage_free_endio(struct page *page, unsigned long offset)
2777 struct buffer_head *head, *bh;
2778 unsigned int curr_off = 0;
2780 if (!page_has_buffers(page))
2782 head = bh = page_buffers(page);
2784 if (offset <= curr_off && test_clear_buffer_uninit(bh)
2786 ext4_free_io_end(bh->b_private);
2787 bh->b_private = NULL;
2788 bh->b_end_io = NULL;
2790 curr_off = curr_off + bh->b_size;
2791 bh = bh->b_this_page;
2792 } while (bh != head);
2795 static void ext4_invalidatepage(struct page *page, unsigned long offset)
2797 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
2799 trace_ext4_invalidatepage(page, offset);
2802 * free any io_end structure allocated for buffers to be discarded
2804 if (ext4_should_dioread_nolock(page->mapping->host))
2805 ext4_invalidatepage_free_endio(page, offset);
2807 * If it's a full truncate we just forget about the pending dirtying
2810 ClearPageChecked(page);
2813 jbd2_journal_invalidatepage(journal, page, offset);
2815 block_invalidatepage(page, offset);
2818 static int ext4_releasepage(struct page *page, gfp_t wait)
2820 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
2822 trace_ext4_releasepage(page);
2824 WARN_ON(PageChecked(page));
2825 if (!page_has_buffers(page))
2828 return jbd2_journal_try_to_free_buffers(journal, page, wait);
2830 return try_to_free_buffers(page);
2834 * ext4_get_block used when preparing for a DIO write or buffer write.
2835 * We allocate an uinitialized extent if blocks haven't been allocated.
2836 * The extent will be converted to initialized after the IO is complete.
2838 static int ext4_get_block_write(struct inode *inode, sector_t iblock,
2839 struct buffer_head *bh_result, int create)
2841 ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n",
2842 inode->i_ino, create);
2843 return _ext4_get_block(inode, iblock, bh_result,
2844 EXT4_GET_BLOCKS_IO_CREATE_EXT);
2847 static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock,
2848 struct buffer_head *bh_result, int flags)
2850 handle_t *handle = ext4_journal_current_handle();
2851 struct ext4_map_blocks map;
2854 ext4_debug("ext4_get_block_write_nolock: inode %lu, flag %d\n",
2855 inode->i_ino, flags);
2857 flags = EXT4_GET_BLOCKS_NO_LOCK;
2859 map.m_lblk = iblock;
2860 map.m_len = bh_result->b_size >> inode->i_blkbits;
2862 ret = ext4_map_blocks(handle, inode, &map, flags);
2864 map_bh(bh_result, inode->i_sb, map.m_pblk);
2865 bh_result->b_state = (bh_result->b_state & ~EXT4_MAP_FLAGS) |
2867 bh_result->b_size = inode->i_sb->s_blocksize * map.m_len;
2873 static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
2874 ssize_t size, void *private, int ret,
2877 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
2878 ext4_io_end_t *io_end = iocb->private;
2879 struct workqueue_struct *wq;
2880 unsigned long flags;
2881 struct ext4_inode_info *ei;
2883 /* if not async direct IO or dio with 0 bytes write, just return */
2884 if (!io_end || !size)
2887 ext_debug("ext4_end_io_dio(): io_end 0x%p "
2888 "for inode %lu, iocb 0x%p, offset %llu, size %zd\n",
2889 iocb->private, io_end->inode->i_ino, iocb, offset,
2892 iocb->private = NULL;
2894 /* if not aio dio with unwritten extents, just free io and return */
2895 if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
2896 ext4_free_io_end(io_end);
2899 aio_complete(iocb, ret, 0);
2900 inode_dio_done(inode);
2904 io_end->offset = offset;
2905 io_end->size = size;
2907 io_end->iocb = iocb;
2908 io_end->result = ret;
2910 wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq;
2912 /* Add the io_end to per-inode completed aio dio list*/
2913 ei = EXT4_I(io_end->inode);
2914 spin_lock_irqsave(&ei->i_completed_io_lock, flags);
2915 list_add_tail(&io_end->list, &ei->i_completed_io_list);
2916 spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
2918 /* queue the work to convert unwritten extents to written */
2919 queue_work(wq, &io_end->work);
2922 static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate)
2924 ext4_io_end_t *io_end = bh->b_private;
2925 struct workqueue_struct *wq;
2926 struct inode *inode;
2927 unsigned long flags;
2929 if (!test_clear_buffer_uninit(bh) || !io_end)
2932 if (!(io_end->inode->i_sb->s_flags & MS_ACTIVE)) {
2933 ext4_msg(io_end->inode->i_sb, KERN_INFO,
2934 "sb umounted, discard end_io request for inode %lu",
2935 io_end->inode->i_ino);
2936 ext4_free_io_end(io_end);
2941 * It may be over-defensive here to check EXT4_IO_END_UNWRITTEN now,
2942 * but being more careful is always safe for the future change.
2944 inode = io_end->inode;
2945 ext4_set_io_unwritten_flag(inode, io_end);
2947 /* Add the io_end to per-inode completed io list*/
2948 spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags);
2949 list_add_tail(&io_end->list, &EXT4_I(inode)->i_completed_io_list);
2950 spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags);
2952 wq = EXT4_SB(inode->i_sb)->dio_unwritten_wq;
2953 /* queue the work to convert unwritten extents to written */
2954 queue_work(wq, &io_end->work);
2956 bh->b_private = NULL;
2957 bh->b_end_io = NULL;
2958 clear_buffer_uninit(bh);
2959 end_buffer_async_write(bh, uptodate);
2962 static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode)
2964 ext4_io_end_t *io_end;
2965 struct page *page = bh->b_page;
2966 loff_t offset = (sector_t)page->index << PAGE_CACHE_SHIFT;
2967 size_t size = bh->b_size;
2970 io_end = ext4_init_io_end(inode, GFP_ATOMIC);
2972 pr_warn_ratelimited("%s: allocation fail\n", __func__);
2976 io_end->offset = offset;
2977 io_end->size = size;
2979 * We need to hold a reference to the page to make sure it
2980 * doesn't get evicted before ext4_end_io_work() has a chance
2981 * to convert the extent from written to unwritten.
2983 io_end->page = page;
2984 get_page(io_end->page);
2986 bh->b_private = io_end;
2987 bh->b_end_io = ext4_end_io_buffer_write;
2992 * For ext4 extent files, ext4 will do direct-io write to holes,
2993 * preallocated extents, and those write extend the file, no need to
2994 * fall back to buffered IO.
2996 * For holes, we fallocate those blocks, mark them as uninitialized
2997 * If those blocks were preallocated, we mark sure they are splited, but
2998 * still keep the range to write as uninitialized.
3000 * The unwrritten extents will be converted to written when DIO is completed.
3001 * For async direct IO, since the IO may still pending when return, we
3002 * set up an end_io call back function, which will do the conversion
3003 * when async direct IO completed.
3005 * If the O_DIRECT write will extend the file then add this inode to the
3006 * orphan list. So recovery will truncate it back to the original size
3007 * if the machine crashes during the write.
3010 static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
3011 const struct iovec *iov, loff_t offset,
3012 unsigned long nr_segs)
3014 struct file *file = iocb->ki_filp;
3015 struct inode *inode = file->f_mapping->host;
3017 size_t count = iov_length(iov, nr_segs);
3019 loff_t final_size = offset + count;
3020 if (rw == WRITE && final_size <= inode->i_size) {
3023 BUG_ON(iocb->private == NULL);
3025 /* If we do a overwrite dio, i_mutex locking can be released */
3026 overwrite = *((int *)iocb->private);
3029 down_read(&EXT4_I(inode)->i_data_sem);
3030 mutex_unlock(&inode->i_mutex);
3034 * We could direct write to holes and fallocate.
3036 * Allocated blocks to fill the hole are marked as uninitialized
3037 * to prevent parallel buffered read to expose the stale data
3038 * before DIO complete the data IO.
3040 * As to previously fallocated extents, ext4 get_block
3041 * will just simply mark the buffer mapped but still
3042 * keep the extents uninitialized.
3044 * for non AIO case, we will convert those unwritten extents
3045 * to written after return back from blockdev_direct_IO.
3047 * for async DIO, the conversion needs to be defered when
3048 * the IO is completed. The ext4 end_io callback function
3049 * will be called to take care of the conversion work.
3050 * Here for async case, we allocate an io_end structure to
3053 iocb->private = NULL;
3054 EXT4_I(inode)->cur_aio_dio = NULL;
3055 if (!is_sync_kiocb(iocb)) {
3056 ext4_io_end_t *io_end =
3057 ext4_init_io_end(inode, GFP_NOFS);
3062 io_end->flag |= EXT4_IO_END_DIRECT;
3063 iocb->private = io_end;
3065 * we save the io structure for current async
3066 * direct IO, so that later ext4_map_blocks()
3067 * could flag the io structure whether there
3068 * is a unwritten extents needs to be converted
3069 * when IO is completed.
3071 EXT4_I(inode)->cur_aio_dio = iocb->private;
3075 ret = __blockdev_direct_IO(rw, iocb, inode,
3076 inode->i_sb->s_bdev, iov,
3078 ext4_get_block_write_nolock,
3083 ret = __blockdev_direct_IO(rw, iocb, inode,
3084 inode->i_sb->s_bdev, iov,
3086 ext4_get_block_write,
3091 EXT4_I(inode)->cur_aio_dio = NULL;
3093 * The io_end structure takes a reference to the inode,
3094 * that structure needs to be destroyed and the
3095 * reference to the inode need to be dropped, when IO is
3096 * complete, even with 0 byte write, or failed.
3098 * In the successful AIO DIO case, the io_end structure will be
3099 * desctroyed and the reference to the inode will be dropped
3100 * after the end_io call back function is called.
3102 * In the case there is 0 byte write, or error case, since
3103 * VFS direct IO won't invoke the end_io call back function,
3104 * we need to free the end_io structure here.
3106 if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
3107 ext4_free_io_end(iocb->private);
3108 iocb->private = NULL;
3109 } else if (ret > 0 && !overwrite && ext4_test_inode_state(inode,
3110 EXT4_STATE_DIO_UNWRITTEN)) {
3113 * for non AIO case, since the IO is already
3114 * completed, we could do the conversion right here
3116 err = ext4_convert_unwritten_extents(inode,
3120 ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3124 /* take i_mutex locking again if we do a ovewrite dio */
3126 up_read(&EXT4_I(inode)->i_data_sem);
3127 mutex_lock(&inode->i_mutex);
3133 /* for write the the end of file case, we fall back to old way */
3134 return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3137 static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
3138 const struct iovec *iov, loff_t offset,
3139 unsigned long nr_segs)
3141 struct file *file = iocb->ki_filp;
3142 struct inode *inode = file->f_mapping->host;
3146 * If we are doing data journalling we don't support O_DIRECT
3148 if (ext4_should_journal_data(inode))
3151 trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);
3152 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3153 ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
3155 ret = ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3156 trace_ext4_direct_IO_exit(inode, offset,
3157 iov_length(iov, nr_segs), rw, ret);
3162 * Pages can be marked dirty completely asynchronously from ext4's journalling
3163 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3164 * much here because ->set_page_dirty is called under VFS locks. The page is
3165 * not necessarily locked.
3167 * We cannot just dirty the page and leave attached buffers clean, because the
3168 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3169 * or jbddirty because all the journalling code will explode.
3171 * So what we do is to mark the page "pending dirty" and next time writepage
3172 * is called, propagate that into the buffers appropriately.
3174 static int ext4_journalled_set_page_dirty(struct page *page)
3176 SetPageChecked(page);
3177 return __set_page_dirty_nobuffers(page);
3180 static const struct address_space_operations ext4_ordered_aops = {
3181 .readpage = ext4_readpage,
3182 .readpages = ext4_readpages,
3183 .writepage = ext4_writepage,
3184 .write_begin = ext4_write_begin,
3185 .write_end = ext4_ordered_write_end,
3187 .invalidatepage = ext4_invalidatepage,
3188 .releasepage = ext4_releasepage,
3189 .direct_IO = ext4_direct_IO,
3190 .migratepage = buffer_migrate_page,
3191 .is_partially_uptodate = block_is_partially_uptodate,
3192 .error_remove_page = generic_error_remove_page,
3195 static const struct address_space_operations ext4_writeback_aops = {
3196 .readpage = ext4_readpage,
3197 .readpages = ext4_readpages,
3198 .writepage = ext4_writepage,
3199 .write_begin = ext4_write_begin,
3200 .write_end = ext4_writeback_write_end,
3202 .invalidatepage = ext4_invalidatepage,
3203 .releasepage = ext4_releasepage,
3204 .direct_IO = ext4_direct_IO,
3205 .migratepage = buffer_migrate_page,
3206 .is_partially_uptodate = block_is_partially_uptodate,
3207 .error_remove_page = generic_error_remove_page,
3210 static const struct address_space_operations ext4_journalled_aops = {
3211 .readpage = ext4_readpage,
3212 .readpages = ext4_readpages,
3213 .writepage = ext4_writepage,
3214 .write_begin = ext4_write_begin,
3215 .write_end = ext4_journalled_write_end,
3216 .set_page_dirty = ext4_journalled_set_page_dirty,
3218 .invalidatepage = ext4_invalidatepage,
3219 .releasepage = ext4_releasepage,
3220 .direct_IO = ext4_direct_IO,
3221 .is_partially_uptodate = block_is_partially_uptodate,
3222 .error_remove_page = generic_error_remove_page,
3225 static const struct address_space_operations ext4_da_aops = {
3226 .readpage = ext4_readpage,
3227 .readpages = ext4_readpages,
3228 .writepage = ext4_writepage,
3229 .writepages = ext4_da_writepages,
3230 .write_begin = ext4_da_write_begin,
3231 .write_end = ext4_da_write_end,
3233 .invalidatepage = ext4_da_invalidatepage,
3234 .releasepage = ext4_releasepage,
3235 .direct_IO = ext4_direct_IO,
3236 .migratepage = buffer_migrate_page,
3237 .is_partially_uptodate = block_is_partially_uptodate,
3238 .error_remove_page = generic_error_remove_page,
3241 void ext4_set_aops(struct inode *inode)
3243 switch (ext4_inode_journal_mode(inode)) {
3244 case EXT4_INODE_ORDERED_DATA_MODE:
3245 if (test_opt(inode->i_sb, DELALLOC))
3246 inode->i_mapping->a_ops = &ext4_da_aops;
3248 inode->i_mapping->a_ops = &ext4_ordered_aops;
3250 case EXT4_INODE_WRITEBACK_DATA_MODE:
3251 if (test_opt(inode->i_sb, DELALLOC))
3252 inode->i_mapping->a_ops = &ext4_da_aops;
3254 inode->i_mapping->a_ops = &ext4_writeback_aops;
3256 case EXT4_INODE_JOURNAL_DATA_MODE:
3257 inode->i_mapping->a_ops = &ext4_journalled_aops;
3266 * ext4_discard_partial_page_buffers()
3267 * Wrapper function for ext4_discard_partial_page_buffers_no_lock.
3268 * This function finds and locks the page containing the offset
3269 * "from" and passes it to ext4_discard_partial_page_buffers_no_lock.
3270 * Calling functions that already have the page locked should call
3271 * ext4_discard_partial_page_buffers_no_lock directly.
3273 int ext4_discard_partial_page_buffers(handle_t *handle,
3274 struct address_space *mapping, loff_t from,
3275 loff_t length, int flags)
3277 struct inode *inode = mapping->host;
3281 page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT,
3282 mapping_gfp_mask(mapping) & ~__GFP_FS);
3286 err = ext4_discard_partial_page_buffers_no_lock(handle, inode, page,
3287 from, length, flags);
3290 page_cache_release(page);
3295 * ext4_discard_partial_page_buffers_no_lock()
3296 * Zeros a page range of length 'length' starting from offset 'from'.
3297 * Buffer heads that correspond to the block aligned regions of the
3298 * zeroed range will be unmapped. Unblock aligned regions
3299 * will have the corresponding buffer head mapped if needed so that
3300 * that region of the page can be updated with the partial zero out.
3302 * This function assumes that the page has already been locked. The
3303 * The range to be discarded must be contained with in the given page.
3304 * If the specified range exceeds the end of the page it will be shortened
3305 * to the end of the page that corresponds to 'from'. This function is
3306 * appropriate for updating a page and it buffer heads to be unmapped and
3307 * zeroed for blocks that have been either released, or are going to be
3310 * handle: The journal handle
3311 * inode: The files inode
3312 * page: A locked page that contains the offset "from"
3313 * from: The starting byte offset (from the begining of the file)
3314 * to begin discarding
3315 * len: The length of bytes to discard
3316 * flags: Optional flags that may be used:
3318 * EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED
3319 * Only zero the regions of the page whose buffer heads
3320 * have already been unmapped. This flag is appropriate
3321 * for updateing the contents of a page whose blocks may
3322 * have already been released, and we only want to zero
3323 * out the regions that correspond to those released blocks.
3325 * Returns zero on sucess or negative on failure.
3327 static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
3328 struct inode *inode, struct page *page, loff_t from,
3329 loff_t length, int flags)
3331 ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
3332 unsigned int offset = from & (PAGE_CACHE_SIZE-1);
3333 unsigned int blocksize, max, pos;
3335 struct buffer_head *bh;
3338 blocksize = inode->i_sb->s_blocksize;
3339 max = PAGE_CACHE_SIZE - offset;
3341 if (index != page->index)
3345 * correct length if it does not fall between
3346 * 'from' and the end of the page
3348 if (length > max || length < 0)
3351 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
3353 if (!page_has_buffers(page))
3354 create_empty_buffers(page, blocksize, 0);
3356 /* Find the buffer that contains "offset" */
3357 bh = page_buffers(page);
3359 while (offset >= pos) {
3360 bh = bh->b_this_page;
3366 while (pos < offset + length) {
3367 unsigned int end_of_block, range_to_discard;
3371 /* The length of space left to zero and unmap */
3372 range_to_discard = offset + length - pos;
3374 /* The length of space until the end of the block */
3375 end_of_block = blocksize - (pos & (blocksize-1));
3378 * Do not unmap or zero past end of block
3379 * for this buffer head
3381 if (range_to_discard > end_of_block)
3382 range_to_discard = end_of_block;
3386 * Skip this buffer head if we are only zeroing unampped
3387 * regions of the page
3389 if (flags & EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED &&
3393 /* If the range is block aligned, unmap */
3394 if (range_to_discard == blocksize) {
3395 clear_buffer_dirty(bh);
3397 clear_buffer_mapped(bh);
3398 clear_buffer_req(bh);
3399 clear_buffer_new(bh);
3400 clear_buffer_delay(bh);
3401 clear_buffer_unwritten(bh);
3402 clear_buffer_uptodate(bh);
3403 zero_user(page, pos, range_to_discard);
3404 BUFFER_TRACE(bh, "Buffer discarded");
3409 * If this block is not completely contained in the range
3410 * to be discarded, then it is not going to be released. Because
3411 * we need to keep this block, we need to make sure this part
3412 * of the page is uptodate before we modify it by writeing
3413 * partial zeros on it.
3415 if (!buffer_mapped(bh)) {
3417 * Buffer head must be mapped before we can read
3420 BUFFER_TRACE(bh, "unmapped");
3421 ext4_get_block(inode, iblock, bh, 0);
3422 /* unmapped? It's a hole - nothing to do */
3423 if (!buffer_mapped(bh)) {
3424 BUFFER_TRACE(bh, "still unmapped");
3429 /* Ok, it's mapped. Make sure it's up-to-date */
3430 if (PageUptodate(page))
3431 set_buffer_uptodate(bh);
3433 if (!buffer_uptodate(bh)) {
3435 ll_rw_block(READ, 1, &bh);
3437 /* Uhhuh. Read error. Complain and punt.*/
3438 if (!buffer_uptodate(bh))
3442 if (ext4_should_journal_data(inode)) {
3443 BUFFER_TRACE(bh, "get write access");
3444 err = ext4_journal_get_write_access(handle, bh);
3449 zero_user(page, pos, range_to_discard);
3452 if (ext4_should_journal_data(inode)) {
3453 err = ext4_handle_dirty_metadata(handle, inode, bh);
3455 mark_buffer_dirty(bh);
3457 BUFFER_TRACE(bh, "Partial buffer zeroed");
3459 bh = bh->b_this_page;
3461 pos += range_to_discard;
3467 int ext4_can_truncate(struct inode *inode)
3469 if (S_ISREG(inode->i_mode))
3471 if (S_ISDIR(inode->i_mode))
3473 if (S_ISLNK(inode->i_mode))
3474 return !ext4_inode_is_fast_symlink(inode);
3479 * ext4_punch_hole: punches a hole in a file by releaseing the blocks
3480 * associated with the given offset and length
3482 * @inode: File inode
3483 * @offset: The offset where the hole will begin
3484 * @len: The length of the hole
3486 * Returns: 0 on sucess or negative on failure
3489 int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
3491 struct inode *inode = file->f_path.dentry->d_inode;
3492 if (!S_ISREG(inode->i_mode))
3495 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
3496 /* TODO: Add support for non extent hole punching */
3500 if (EXT4_SB(inode->i_sb)->s_cluster_ratio > 1) {
3501 /* TODO: Add support for bigalloc file systems */
3505 return ext4_ext_punch_hole(file, offset, length);
3511 * We block out ext4_get_block() block instantiations across the entire
3512 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
3513 * simultaneously on behalf of the same inode.
3515 * As we work through the truncate and commit bits of it to the journal there
3516 * is one core, guiding principle: the file's tree must always be consistent on
3517 * disk. We must be able to restart the truncate after a crash.
3519 * The file's tree may be transiently inconsistent in memory (although it
3520 * probably isn't), but whenever we close off and commit a journal transaction,
3521 * the contents of (the filesystem + the journal) must be consistent and
3522 * restartable. It's pretty simple, really: bottom up, right to left (although
3523 * left-to-right works OK too).
3525 * Note that at recovery time, journal replay occurs *before* the restart of
3526 * truncate against the orphan inode list.
3528 * The committed inode has the new, desired i_size (which is the same as
3529 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
3530 * that this inode's truncate did not complete and it will again call
3531 * ext4_truncate() to have another go. So there will be instantiated blocks
3532 * to the right of the truncation point in a crashed ext4 filesystem. But
3533 * that's fine - as long as they are linked from the inode, the post-crash
3534 * ext4_truncate() run will find them and release them.
3536 void ext4_truncate(struct inode *inode)
3538 trace_ext4_truncate_enter(inode);
3540 if (!ext4_can_truncate(inode))
3543 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3545 if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
3546 ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
3548 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3549 ext4_ext_truncate(inode);
3551 ext4_ind_truncate(inode);
3553 trace_ext4_truncate_exit(inode);
3557 * ext4_get_inode_loc returns with an extra refcount against the inode's
3558 * underlying buffer_head on success. If 'in_mem' is true, we have all
3559 * data in memory that is needed to recreate the on-disk version of this
3562 static int __ext4_get_inode_loc(struct inode *inode,
3563 struct ext4_iloc *iloc, int in_mem)
3565 struct ext4_group_desc *gdp;
3566 struct buffer_head *bh;
3567 struct super_block *sb = inode->i_sb;
3569 int inodes_per_block, inode_offset;
3572 if (!ext4_valid_inum(sb, inode->i_ino))
3575 iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
3576 gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
3581 * Figure out the offset within the block group inode table
3583 inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
3584 inode_offset = ((inode->i_ino - 1) %
3585 EXT4_INODES_PER_GROUP(sb));
3586 block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
3587 iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
3589 bh = sb_getblk(sb, block);
3591 EXT4_ERROR_INODE_BLOCK(inode, block,
3592 "unable to read itable block");
3595 if (!buffer_uptodate(bh)) {
3599 * If the buffer has the write error flag, we have failed
3600 * to write out another inode in the same block. In this
3601 * case, we don't have to read the block because we may
3602 * read the old inode data successfully.
3604 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
3605 set_buffer_uptodate(bh);
3607 if (buffer_uptodate(bh)) {
3608 /* someone brought it uptodate while we waited */
3614 * If we have all information of the inode in memory and this
3615 * is the only valid inode in the block, we need not read the
3619 struct buffer_head *bitmap_bh;
3622 start = inode_offset & ~(inodes_per_block - 1);
3624 /* Is the inode bitmap in cache? */
3625 bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
3630 * If the inode bitmap isn't in cache then the
3631 * optimisation may end up performing two reads instead
3632 * of one, so skip it.
3634 if (!buffer_uptodate(bitmap_bh)) {
3638 for (i = start; i < start + inodes_per_block; i++) {
3639 if (i == inode_offset)
3641 if (ext4_test_bit(i, bitmap_bh->b_data))
3645 if (i == start + inodes_per_block) {
3646 /* all other inodes are free, so skip I/O */
3647 memset(bh->b_data, 0, bh->b_size);
3648 set_buffer_uptodate(bh);
3656 * If we need to do any I/O, try to pre-readahead extra
3657 * blocks from the inode table.
3659 if (EXT4_SB(sb)->s_inode_readahead_blks) {
3660 ext4_fsblk_t b, end, table;
3663 table = ext4_inode_table(sb, gdp);
3664 /* s_inode_readahead_blks is always a power of 2 */
3665 b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1);
3668 end = b + EXT4_SB(sb)->s_inode_readahead_blks;
3669 num = EXT4_INODES_PER_GROUP(sb);
3670 if (ext4_has_group_desc_csum(sb))
3671 num -= ext4_itable_unused_count(sb, gdp);
3672 table += num / inodes_per_block;
3676 sb_breadahead(sb, b++);
3680 * There are other valid inodes in the buffer, this inode
3681 * has in-inode xattrs, or we don't have this inode in memory.
3682 * Read the block from disk.
3684 trace_ext4_load_inode(inode);
3686 bh->b_end_io = end_buffer_read_sync;
3687 submit_bh(READ | REQ_META | REQ_PRIO, bh);
3689 if (!buffer_uptodate(bh)) {
3690 EXT4_ERROR_INODE_BLOCK(inode, block,
3691 "unable to read itable block");
3701 int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
3703 /* We have all inode data except xattrs in memory here. */
3704 return __ext4_get_inode_loc(inode, iloc,
3705 !ext4_test_inode_state(inode, EXT4_STATE_XATTR));
3708 void ext4_set_inode_flags(struct inode *inode)
3710 unsigned int flags = EXT4_I(inode)->i_flags;
3712 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
3713 if (flags & EXT4_SYNC_FL)
3714 inode->i_flags |= S_SYNC;
3715 if (flags & EXT4_APPEND_FL)
3716 inode->i_flags |= S_APPEND;
3717 if (flags & EXT4_IMMUTABLE_FL)
3718 inode->i_flags |= S_IMMUTABLE;
3719 if (flags & EXT4_NOATIME_FL)
3720 inode->i_flags |= S_NOATIME;
3721 if (flags & EXT4_DIRSYNC_FL)
3722 inode->i_flags |= S_DIRSYNC;
3725 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
3726 void ext4_get_inode_flags(struct ext4_inode_info *ei)
3728 unsigned int vfs_fl;
3729 unsigned long old_fl, new_fl;
3732 vfs_fl = ei->vfs_inode.i_flags;
3733 old_fl = ei->i_flags;
3734 new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
3735 EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|
3737 if (vfs_fl & S_SYNC)
3738 new_fl |= EXT4_SYNC_FL;
3739 if (vfs_fl & S_APPEND)
3740 new_fl |= EXT4_APPEND_FL;
3741 if (vfs_fl & S_IMMUTABLE)
3742 new_fl |= EXT4_IMMUTABLE_FL;
3743 if (vfs_fl & S_NOATIME)
3744 new_fl |= EXT4_NOATIME_FL;
3745 if (vfs_fl & S_DIRSYNC)
3746 new_fl |= EXT4_DIRSYNC_FL;
3747 } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl);
3750 static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
3751 struct ext4_inode_info *ei)
3754 struct inode *inode = &(ei->vfs_inode);
3755 struct super_block *sb = inode->i_sb;
3757 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3758 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
3759 /* we are using combined 48 bit field */
3760 i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
3761 le32_to_cpu(raw_inode->i_blocks_lo);
3762 if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) {
3763 /* i_blocks represent file system block size */
3764 return i_blocks << (inode->i_blkbits - 9);
3769 return le32_to_cpu(raw_inode->i_blocks_lo);
3773 struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
3775 struct ext4_iloc iloc;
3776 struct ext4_inode *raw_inode;
3777 struct ext4_inode_info *ei;
3778 struct inode *inode;
3779 journal_t *journal = EXT4_SB(sb)->s_journal;
3785 inode = iget_locked(sb, ino);
3787 return ERR_PTR(-ENOMEM);
3788 if (!(inode->i_state & I_NEW))
3794 ret = __ext4_get_inode_loc(inode, &iloc, 0);
3797 raw_inode = ext4_raw_inode(&iloc);
3799 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
3800 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
3801 if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
3802 EXT4_INODE_SIZE(inode->i_sb)) {
3803 EXT4_ERROR_INODE(inode, "bad extra_isize (%u != %u)",
3804 EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize,
3805 EXT4_INODE_SIZE(inode->i_sb));
3810 ei->i_extra_isize = 0;
3812 /* Precompute checksum seed for inode metadata */
3813 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3814 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3815 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3817 __le32 inum = cpu_to_le32(inode->i_ino);
3818 __le32 gen = raw_inode->i_generation;
3819 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
3821 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
3825 if (!ext4_inode_csum_verify(inode, raw_inode, ei)) {
3826 EXT4_ERROR_INODE(inode, "checksum invalid");
3831 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
3832 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
3833 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
3834 if (!(test_opt(inode->i_sb, NO_UID32))) {
3835 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
3836 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
3838 i_uid_write(inode, i_uid);
3839 i_gid_write(inode, i_gid);
3840 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
3842 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
3843 ei->i_dir_start_lookup = 0;
3844 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
3845 /* We now have enough fields to check if the inode was active or not.
3846 * This is needed because nfsd might try to access dead inodes
3847 * the test is that same one that e2fsck uses
3848 * NeilBrown 1999oct15
3850 if (inode->i_nlink == 0) {
3851 if (inode->i_mode == 0 ||
3852 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
3853 /* this inode is deleted */
3857 /* The only unlinked inodes we let through here have
3858 * valid i_mode and are being read by the orphan
3859 * recovery code: that's fine, we're about to complete
3860 * the process of deleting those. */
3862 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
3863 inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
3864 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
3865 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT))
3867 ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
3868 inode->i_size = ext4_isize(raw_inode);
3869 ei->i_disksize = inode->i_size;
3871 ei->i_reserved_quota = 0;
3873 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
3874 ei->i_block_group = iloc.block_group;
3875 ei->i_last_alloc_group = ~0;
3877 * NOTE! The in-memory inode i_data array is in little-endian order
3878 * even on big-endian machines: we do NOT byteswap the block numbers!
3880 for (block = 0; block < EXT4_N_BLOCKS; block++)
3881 ei->i_data[block] = raw_inode->i_block[block];
3882 INIT_LIST_HEAD(&ei->i_orphan);
3885 * Set transaction id's of transactions that have to be committed
3886 * to finish f[data]sync. We set them to currently running transaction
3887 * as we cannot be sure that the inode or some of its metadata isn't
3888 * part of the transaction - the inode could have been reclaimed and
3889 * now it is reread from disk.
3892 transaction_t *transaction;
3895 read_lock(&journal->j_state_lock);
3896 if (journal->j_running_transaction)
3897 transaction = journal->j_running_transaction;
3899 transaction = journal->j_committing_transaction;
3901 tid = transaction->t_tid;
3903 tid = journal->j_commit_sequence;
3904 read_unlock(&journal->j_state_lock);
3905 ei->i_sync_tid = tid;
3906 ei->i_datasync_tid = tid;
3909 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
3910 if (ei->i_extra_isize == 0) {
3911 /* The extra space is currently unused. Use it. */
3912 ei->i_extra_isize = sizeof(struct ext4_inode) -
3913 EXT4_GOOD_OLD_INODE_SIZE;
3915 __le32 *magic = (void *)raw_inode +
3916 EXT4_GOOD_OLD_INODE_SIZE +
3918 if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC))
3919 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
3923 EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
3924 EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
3925 EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
3926 EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
3928 inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
3929 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
3930 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
3932 (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
3936 if (ei->i_file_acl &&
3937 !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) {
3938 EXT4_ERROR_INODE(inode, "bad extended attribute block %llu",
3942 } else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
3943 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 extent which is part of inode */
3947 ret = ext4_ext_check_inode(inode);
3948 } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
3949 (S_ISLNK(inode->i_mode) &&
3950 !ext4_inode_is_fast_symlink(inode))) {
3951 /* Validate block references which are part of inode */
3952 ret = ext4_ind_check_inode(inode);
3957 if (S_ISREG(inode->i_mode)) {
3958 inode->i_op = &ext4_file_inode_operations;
3959 inode->i_fop = &ext4_file_operations;
3960 ext4_set_aops(inode);
3961 } else if (S_ISDIR(inode->i_mode)) {
3962 inode->i_op = &ext4_dir_inode_operations;
3963 inode->i_fop = &ext4_dir_operations;
3964 } else if (S_ISLNK(inode->i_mode)) {
3965 if (ext4_inode_is_fast_symlink(inode)) {
3966 inode->i_op = &ext4_fast_symlink_inode_operations;
3967 nd_terminate_link(ei->i_data, inode->i_size,
3968 sizeof(ei->i_data) - 1);
3970 inode->i_op = &ext4_symlink_inode_operations;
3971 ext4_set_aops(inode);
3973 } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
3974 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
3975 inode->i_op = &ext4_special_inode_operations;
3976 if (raw_inode->i_block[0])
3977 init_special_inode(inode, inode->i_mode,
3978 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
3980 init_special_inode(inode, inode->i_mode,
3981 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
3984 EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode);
3988 ext4_set_inode_flags(inode);
3989 unlock_new_inode(inode);
3995 return ERR_PTR(ret);
3998 static int ext4_inode_blocks_set(handle_t *handle,
3999 struct ext4_inode *raw_inode,
4000 struct ext4_inode_info *ei)
4002 struct inode *inode = &(ei->vfs_inode);
4003 u64 i_blocks = inode->i_blocks;
4004 struct super_block *sb = inode->i_sb;
4006 if (i_blocks <= ~0U) {
4008 * i_blocks can be represnted in a 32 bit variable
4009 * as multiple of 512 bytes
4011 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4012 raw_inode->i_blocks_high = 0;
4013 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4016 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE))
4019 if (i_blocks <= 0xffffffffffffULL) {
4021 * i_blocks can be represented in a 48 bit variable
4022 * as multiple of 512 bytes
4024 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4025 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
4026 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4028 ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4029 /* i_block is stored in file system block size */
4030 i_blocks = i_blocks >> (inode->i_blkbits - 9);
4031 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4032 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
4038 * Post the struct inode info into an on-disk inode location in the
4039 * buffer-cache. This gobbles the caller's reference to the
4040 * buffer_head in the inode location struct.
4042 * The caller must have write access to iloc->bh.
4044 static int ext4_do_update_inode(handle_t *handle,
4045 struct inode *inode,
4046 struct ext4_iloc *iloc)
4048 struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
4049 struct ext4_inode_info *ei = EXT4_I(inode);
4050 struct buffer_head *bh = iloc->bh;
4051 int err = 0, rc, block;
4055 /* For fields not not tracking in the in-memory inode,
4056 * initialise them to zero for new inodes. */
4057 if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
4058 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
4060 ext4_get_inode_flags(ei);
4061 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
4062 i_uid = i_uid_read(inode);
4063 i_gid = i_gid_read(inode);
4064 if (!(test_opt(inode->i_sb, NO_UID32))) {
4065 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
4066 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
4068 * Fix up interoperability with old kernels. Otherwise, old inodes get
4069 * re-used with the upper 16 bits of the uid/gid intact
4072 raw_inode->i_uid_high =
4073 cpu_to_le16(high_16_bits(i_uid));
4074 raw_inode->i_gid_high =
4075 cpu_to_le16(high_16_bits(i_gid));
4077 raw_inode->i_uid_high = 0;
4078 raw_inode->i_gid_high = 0;
4081 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid));
4082 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid));
4083 raw_inode->i_uid_high = 0;
4084 raw_inode->i_gid_high = 0;
4086 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
4088 EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
4089 EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
4090 EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
4091 EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
4093 if (ext4_inode_blocks_set(handle, raw_inode, ei))
4095 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
4096 raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
4097 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
4098 cpu_to_le32(EXT4_OS_HURD))
4099 raw_inode->i_file_acl_high =
4100 cpu_to_le16(ei->i_file_acl >> 32);
4101 raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
4102 ext4_isize_set(raw_inode, ei->i_disksize);
4103 if (ei->i_disksize > 0x7fffffffULL) {
4104 struct super_block *sb = inode->i_sb;
4105 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
4106 EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||
4107 EXT4_SB(sb)->s_es->s_rev_level ==
4108 cpu_to_le32(EXT4_GOOD_OLD_REV)) {
4109 /* If this is the first large file
4110 * created, add a flag to the superblock.
4112 err = ext4_journal_get_write_access(handle,
4113 EXT4_SB(sb)->s_sbh);
4116 ext4_update_dynamic_rev(sb);
4117 EXT4_SET_RO_COMPAT_FEATURE(sb,
4118 EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
4119 ext4_handle_sync(handle);
4120 err = ext4_handle_dirty_super(handle, sb);
4123 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
4124 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
4125 if (old_valid_dev(inode->i_rdev)) {
4126 raw_inode->i_block[0] =
4127 cpu_to_le32(old_encode_dev(inode->i_rdev));
4128 raw_inode->i_block[1] = 0;
4130 raw_inode->i_block[0] = 0;
4131 raw_inode->i_block[1] =
4132 cpu_to_le32(new_encode_dev(inode->i_rdev));
4133 raw_inode->i_block[2] = 0;
4136 for (block = 0; block < EXT4_N_BLOCKS; block++)
4137 raw_inode->i_block[block] = ei->i_data[block];
4139 raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
4140 if (ei->i_extra_isize) {
4141 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4142 raw_inode->i_version_hi =
4143 cpu_to_le32(inode->i_version >> 32);
4144 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
4147 ext4_inode_csum_set(inode, raw_inode, ei);
4149 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
4150 rc = ext4_handle_dirty_metadata(handle, NULL, bh);
4153 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
4155 ext4_update_inode_fsync_trans(handle, inode, 0);
4158 ext4_std_error(inode->i_sb, err);
4163 * ext4_write_inode()
4165 * We are called from a few places:
4167 * - Within generic_file_write() for O_SYNC files.
4168 * Here, there will be no transaction running. We wait for any running
4169 * trasnaction to commit.
4171 * - Within sys_sync(), kupdate and such.
4172 * We wait on commit, if tol to.
4174 * - Within prune_icache() (PF_MEMALLOC == true)
4175 * Here we simply return. We can't afford to block kswapd on the
4178 * In all cases it is actually safe for us to return without doing anything,
4179 * because the inode has been copied into a raw inode buffer in
4180 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
4183 * Note that we are absolutely dependent upon all inode dirtiers doing the
4184 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4185 * which we are interested.
4187 * It would be a bug for them to not do this. The code:
4189 * mark_inode_dirty(inode)
4191 * inode->i_size = expr;
4193 * is in error because a kswapd-driven write_inode() could occur while
4194 * `stuff()' is running, and the new i_size will be lost. Plus the inode
4195 * will no longer be on the superblock's dirty inode list.
4197 int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
4201 if (current->flags & PF_MEMALLOC)
4204 if (EXT4_SB(inode->i_sb)->s_journal) {
4205 if (ext4_journal_current_handle()) {
4206 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
4211 if (wbc->sync_mode != WB_SYNC_ALL)
4214 err = ext4_force_commit(inode->i_sb);
4216 struct ext4_iloc iloc;
4218 err = __ext4_get_inode_loc(inode, &iloc, 0);
4221 if (wbc->sync_mode == WB_SYNC_ALL)
4222 sync_dirty_buffer(iloc.bh);
4223 if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) {
4224 EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr,
4225 "IO error syncing inode");
4236 * Called from notify_change.
4238 * We want to trap VFS attempts to truncate the file as soon as
4239 * possible. In particular, we want to make sure that when the VFS
4240 * shrinks i_size, we put the inode on the orphan list and modify
4241 * i_disksize immediately, so that during the subsequent flushing of
4242 * dirty pages and freeing of disk blocks, we can guarantee that any
4243 * commit will leave the blocks being flushed in an unused state on
4244 * disk. (On recovery, the inode will get truncated and the blocks will
4245 * be freed, so we have a strong guarantee that no future commit will
4246 * leave these blocks visible to the user.)
4248 * Another thing we have to assure is that if we are in ordered mode
4249 * and inode is still attached to the committing transaction, we must
4250 * we start writeout of all the dirty pages which are being truncated.
4251 * This way we are sure that all the data written in the previous
4252 * transaction are already on disk (truncate waits for pages under
4255 * Called with inode->i_mutex down.
4257 int ext4_setattr(struct dentry *dentry, struct iattr *attr)
4259 struct inode *inode = dentry->d_inode;
4262 const unsigned int ia_valid = attr->ia_valid;
4264 error = inode_change_ok(inode, attr);
4268 if (is_quota_modification(inode, attr))
4269 dquot_initialize(inode);
4270 if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) ||
4271 (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) {
4274 /* (user+group)*(old+new) structure, inode write (sb,
4275 * inode block, ? - but truncate inode update has it) */
4276 handle = ext4_journal_start(inode, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)+
4277 EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb))+3);
4278 if (IS_ERR(handle)) {
4279 error = PTR_ERR(handle);
4282 error = dquot_transfer(inode, attr);
4284 ext4_journal_stop(handle);
4287 /* Update corresponding info in inode so that everything is in
4288 * one transaction */
4289 if (attr->ia_valid & ATTR_UID)
4290 inode->i_uid = attr->ia_uid;
4291 if (attr->ia_valid & ATTR_GID)
4292 inode->i_gid = attr->ia_gid;
4293 error = ext4_mark_inode_dirty(handle, inode);
4294 ext4_journal_stop(handle);
4297 if (attr->ia_valid & ATTR_SIZE) {
4298 inode_dio_wait(inode);
4300 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4301 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4303 if (attr->ia_size > sbi->s_bitmap_maxbytes)
4308 if (S_ISREG(inode->i_mode) &&
4309 attr->ia_valid & ATTR_SIZE &&
4310 (attr->ia_size < inode->i_size)) {
4313 handle = ext4_journal_start(inode, 3);
4314 if (IS_ERR(handle)) {
4315 error = PTR_ERR(handle);
4318 if (ext4_handle_valid(handle)) {
4319 error = ext4_orphan_add(handle, inode);
4322 EXT4_I(inode)->i_disksize = attr->ia_size;
4323 rc = ext4_mark_inode_dirty(handle, inode);
4326 ext4_journal_stop(handle);
4328 if (ext4_should_order_data(inode)) {
4329 error = ext4_begin_ordered_truncate(inode,
4332 /* Do as much error cleanup as possible */
4333 handle = ext4_journal_start(inode, 3);
4334 if (IS_ERR(handle)) {
4335 ext4_orphan_del(NULL, inode);
4338 ext4_orphan_del(handle, inode);
4340 ext4_journal_stop(handle);
4346 if (attr->ia_valid & ATTR_SIZE) {
4347 if (attr->ia_size != i_size_read(inode))
4348 truncate_setsize(inode, attr->ia_size);
4349 ext4_truncate(inode);
4353 setattr_copy(inode, attr);
4354 mark_inode_dirty(inode);
4358 * If the call to ext4_truncate failed to get a transaction handle at
4359 * all, we need to clean up the in-core orphan list manually.
4361 if (orphan && inode->i_nlink)
4362 ext4_orphan_del(NULL, inode);
4364 if (!rc && (ia_valid & ATTR_MODE))
4365 rc = ext4_acl_chmod(inode);
4368 ext4_std_error(inode->i_sb, error);
4374 int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
4377 struct inode *inode;
4378 unsigned long delalloc_blocks;
4380 inode = dentry->d_inode;
4381 generic_fillattr(inode, stat);
4384 * We can't update i_blocks if the block allocation is delayed
4385 * otherwise in the case of system crash before the real block
4386 * allocation is done, we will have i_blocks inconsistent with
4387 * on-disk file blocks.
4388 * We always keep i_blocks updated together with real
4389 * allocation. But to not confuse with user, stat
4390 * will return the blocks that include the delayed allocation
4391 * blocks for this file.
4393 delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb),
4394 EXT4_I(inode)->i_reserved_data_blocks);
4396 stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
4400 static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
4402 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4403 return ext4_ind_trans_blocks(inode, nrblocks, chunk);
4404 return ext4_ext_index_trans_blocks(inode, nrblocks, chunk);
4408 * Account for index blocks, block groups bitmaps and block group
4409 * descriptor blocks if modify datablocks and index blocks
4410 * worse case, the indexs blocks spread over different block groups
4412 * If datablocks are discontiguous, they are possible to spread over
4413 * different block groups too. If they are contiuguous, with flexbg,
4414 * they could still across block group boundary.
4416 * Also account for superblock, inode, quota and xattr blocks
4418 static int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
4420 ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
4426 * How many index blocks need to touch to modify nrblocks?
4427 * The "Chunk" flag indicating whether the nrblocks is
4428 * physically contiguous on disk
4430 * For Direct IO and fallocate, they calls get_block to allocate
4431 * one single extent at a time, so they could set the "Chunk" flag
4433 idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
4438 * Now let's see how many group bitmaps and group descriptors need
4448 if (groups > ngroups)
4450 if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
4451 gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
4453 /* bitmaps and block group descriptor blocks */
4454 ret += groups + gdpblocks;
4456 /* Blocks for super block, inode, quota and xattr blocks */
4457 ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
4463 * Calculate the total number of credits to reserve to fit
4464 * the modification of a single pages into a single transaction,
4465 * which may include multiple chunks of block allocations.
4467 * This could be called via ext4_write_begin()
4469 * We need to consider the worse case, when
4470 * one new block per extent.
4472 int ext4_writepage_trans_blocks(struct inode *inode)
4474 int bpp = ext4_journal_blocks_per_page(inode);
4477 ret = ext4_meta_trans_blocks(inode, bpp, 0);
4479 /* Account for data blocks for journalled mode */
4480 if (ext4_should_journal_data(inode))
4486 * Calculate the journal credits for a chunk of data modification.
4488 * This is called from DIO, fallocate or whoever calling
4489 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
4491 * journal buffers for data blocks are not included here, as DIO
4492 * and fallocate do no need to journal data buffers.
4494 int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
4496 return ext4_meta_trans_blocks(inode, nrblocks, 1);
4500 * The caller must have previously called ext4_reserve_inode_write().
4501 * Give this, we know that the caller already has write access to iloc->bh.
4503 int ext4_mark_iloc_dirty(handle_t *handle,
4504 struct inode *inode, struct ext4_iloc *iloc)
4508 if (IS_I_VERSION(inode))
4509 inode_inc_iversion(inode);
4511 /* the do_update_inode consumes one bh->b_count */
4514 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
4515 err = ext4_do_update_inode(handle, inode, iloc);
4521 * On success, We end up with an outstanding reference count against
4522 * iloc->bh. This _must_ be cleaned up later.
4526 ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
4527 struct ext4_iloc *iloc)
4531 err = ext4_get_inode_loc(inode, iloc);
4533 BUFFER_TRACE(iloc->bh, "get_write_access");
4534 err = ext4_journal_get_write_access(handle, iloc->bh);
4540 ext4_std_error(inode->i_sb, err);
4545 * Expand an inode by new_extra_isize bytes.
4546 * Returns 0 on success or negative error number on failure.
4548 static int ext4_expand_extra_isize(struct inode *inode,
4549 unsigned int new_extra_isize,
4550 struct ext4_iloc iloc,
4553 struct ext4_inode *raw_inode;
4554 struct ext4_xattr_ibody_header *header;
4556 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
4559 raw_inode = ext4_raw_inode(&iloc);
4561 header = IHDR(inode, raw_inode);
4563 /* No extended attributes present */
4564 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
4565 header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
4566 memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
4568 EXT4_I(inode)->i_extra_isize = new_extra_isize;
4572 /* try to expand with EAs present */
4573 return ext4_expand_extra_isize_ea(inode, new_extra_isize,
4578 * What we do here is to mark the in-core inode as clean with respect to inode
4579 * dirtiness (it may still be data-dirty).
4580 * This means that the in-core inode may be reaped by prune_icache
4581 * without having to perform any I/O. This is a very good thing,
4582 * because *any* task may call prune_icache - even ones which
4583 * have a transaction open against a different journal.
4585 * Is this cheating? Not really. Sure, we haven't written the
4586 * inode out, but prune_icache isn't a user-visible syncing function.
4587 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
4588 * we start and wait on commits.
4590 * Is this efficient/effective? Well, we're being nice to the system
4591 * by cleaning up our inodes proactively so they can be reaped
4592 * without I/O. But we are potentially leaving up to five seconds'
4593 * worth of inodes floating about which prune_icache wants us to
4594 * write out. One way to fix that would be to get prune_icache()
4595 * to do a write_super() to free up some memory. It has the desired
4598 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
4600 struct ext4_iloc iloc;
4601 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4602 static unsigned int mnt_count;
4606 trace_ext4_mark_inode_dirty(inode, _RET_IP_);
4607 err = ext4_reserve_inode_write(handle, inode, &iloc);
4608 if (ext4_handle_valid(handle) &&
4609 EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
4610 !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
4612 * We need extra buffer credits since we may write into EA block
4613 * with this same handle. If journal_extend fails, then it will
4614 * only result in a minor loss of functionality for that inode.
4615 * If this is felt to be critical, then e2fsck should be run to
4616 * force a large enough s_min_extra_isize.
4618 if ((jbd2_journal_extend(handle,
4619 EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
4620 ret = ext4_expand_extra_isize(inode,
4621 sbi->s_want_extra_isize,
4624 ext4_set_inode_state(inode,
4625 EXT4_STATE_NO_EXPAND);
4627 le16_to_cpu(sbi->s_es->s_mnt_count)) {
4628 ext4_warning(inode->i_sb,
4629 "Unable to expand inode %lu. Delete"
4630 " some EAs or run e2fsck.",
4633 le16_to_cpu(sbi->s_es->s_mnt_count);
4639 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
4644 * ext4_dirty_inode() is called from __mark_inode_dirty()
4646 * We're really interested in the case where a file is being extended.
4647 * i_size has been changed by generic_commit_write() and we thus need
4648 * to include the updated inode in the current transaction.
4650 * Also, dquot_alloc_block() will always dirty the inode when blocks
4651 * are allocated to the file.
4653 * If the inode is marked synchronous, we don't honour that here - doing
4654 * so would cause a commit on atime updates, which we don't bother doing.
4655 * We handle synchronous inodes at the highest possible level.
4657 void ext4_dirty_inode(struct inode *inode, int flags)
4661 handle = ext4_journal_start(inode, 2);
4665 ext4_mark_inode_dirty(handle, inode);
4667 ext4_journal_stop(handle);
4674 * Bind an inode's backing buffer_head into this transaction, to prevent
4675 * it from being flushed to disk early. Unlike
4676 * ext4_reserve_inode_write, this leaves behind no bh reference and
4677 * returns no iloc structure, so the caller needs to repeat the iloc
4678 * lookup to mark the inode dirty later.
4680 static int ext4_pin_inode(handle_t *handle, struct inode *inode)
4682 struct ext4_iloc iloc;
4686 err = ext4_get_inode_loc(inode, &iloc);
4688 BUFFER_TRACE(iloc.bh, "get_write_access");
4689 err = jbd2_journal_get_write_access(handle, iloc.bh);
4691 err = ext4_handle_dirty_metadata(handle,
4697 ext4_std_error(inode->i_sb, err);
4702 int ext4_change_inode_journal_flag(struct inode *inode, int val)
4709 * We have to be very careful here: changing a data block's
4710 * journaling status dynamically is dangerous. If we write a
4711 * data block to the journal, change the status and then delete
4712 * that block, we risk forgetting to revoke the old log record
4713 * from the journal and so a subsequent replay can corrupt data.
4714 * So, first we make sure that the journal is empty and that
4715 * nobody is changing anything.
4718 journal = EXT4_JOURNAL(inode);
4721 if (is_journal_aborted(journal))
4723 /* We have to allocate physical blocks for delalloc blocks
4724 * before flushing journal. otherwise delalloc blocks can not
4725 * be allocated any more. even more truncate on delalloc blocks
4726 * could trigger BUG by flushing delalloc blocks in journal.
4727 * There is no delalloc block in non-journal data mode.
4729 if (val && test_opt(inode->i_sb, DELALLOC)) {
4730 err = ext4_alloc_da_blocks(inode);
4735 jbd2_journal_lock_updates(journal);
4738 * OK, there are no updates running now, and all cached data is
4739 * synced to disk. We are now in a completely consistent state
4740 * which doesn't have anything in the journal, and we know that
4741 * no filesystem updates are running, so it is safe to modify
4742 * the inode's in-core data-journaling state flag now.
4746 ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
4748 jbd2_journal_flush(journal);
4749 ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
4751 ext4_set_aops(inode);
4753 jbd2_journal_unlock_updates(journal);
4755 /* Finally we can mark the inode as dirty. */
4757 handle = ext4_journal_start(inode, 1);
4759 return PTR_ERR(handle);
4761 err = ext4_mark_inode_dirty(handle, inode);
4762 ext4_handle_sync(handle);
4763 ext4_journal_stop(handle);
4764 ext4_std_error(inode->i_sb, err);
4769 static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
4771 return !buffer_mapped(bh);
4774 int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
4776 struct page *page = vmf->page;
4780 struct file *file = vma->vm_file;
4781 struct inode *inode = file->f_path.dentry->d_inode;
4782 struct address_space *mapping = inode->i_mapping;
4784 get_block_t *get_block;
4787 sb_start_pagefault(inode->i_sb);
4788 /* Delalloc case is easy... */
4789 if (test_opt(inode->i_sb, DELALLOC) &&
4790 !ext4_should_journal_data(inode) &&
4791 !ext4_nonda_switch(inode->i_sb)) {
4793 ret = __block_page_mkwrite(vma, vmf,
4794 ext4_da_get_block_prep);
4795 } while (ret == -ENOSPC &&
4796 ext4_should_retry_alloc(inode->i_sb, &retries));
4801 size = i_size_read(inode);
4802 /* Page got truncated from under us? */
4803 if (page->mapping != mapping || page_offset(page) > size) {
4805 ret = VM_FAULT_NOPAGE;
4809 if (page->index == size >> PAGE_CACHE_SHIFT)
4810 len = size & ~PAGE_CACHE_MASK;
4812 len = PAGE_CACHE_SIZE;
4814 * Return if we have all the buffers mapped. This avoids the need to do
4815 * journal_start/journal_stop which can block and take a long time
4817 if (page_has_buffers(page)) {
4818 if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
4819 ext4_bh_unmapped)) {
4820 /* Wait so that we don't change page under IO */
4821 wait_on_page_writeback(page);
4822 ret = VM_FAULT_LOCKED;
4827 /* OK, we need to fill the hole... */
4828 if (ext4_should_dioread_nolock(inode))
4829 get_block = ext4_get_block_write;
4831 get_block = ext4_get_block;
4833 handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
4834 if (IS_ERR(handle)) {
4835 ret = VM_FAULT_SIGBUS;
4838 ret = __block_page_mkwrite(vma, vmf, get_block);
4839 if (!ret && ext4_should_journal_data(inode)) {
4840 if (walk_page_buffers(handle, page_buffers(page), 0,
4841 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access)) {
4843 ret = VM_FAULT_SIGBUS;
4844 ext4_journal_stop(handle);
4847 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
4849 ext4_journal_stop(handle);
4850 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
4853 ret = block_page_mkwrite_return(ret);
4855 sb_end_pagefault(inode->i_sb);