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 __ext4_journalled_writepage(struct page *page, unsigned int len);
136 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
137 static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
138 struct inode *inode, struct page *page, loff_t from,
139 loff_t length, int flags);
142 * Test whether an inode is a fast symlink.
144 static int ext4_inode_is_fast_symlink(struct inode *inode)
146 int ea_blocks = EXT4_I(inode)->i_file_acl ?
147 (inode->i_sb->s_blocksize >> 9) : 0;
149 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
153 * Restart the transaction associated with *handle. This does a commit,
154 * so before we call here everything must be consistently dirtied against
157 int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
163 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
164 * moment, get_block can be called only for blocks inside i_size since
165 * page cache has been already dropped and writes are blocked by
166 * i_mutex. So we can safely drop the i_data_sem here.
168 BUG_ON(EXT4_JOURNAL(inode) == NULL);
169 jbd_debug(2, "restarting handle %p\n", handle);
170 up_write(&EXT4_I(inode)->i_data_sem);
171 ret = ext4_journal_restart(handle, nblocks);
172 down_write(&EXT4_I(inode)->i_data_sem);
173 ext4_discard_preallocations(inode);
179 * Called at the last iput() if i_nlink is zero.
181 void ext4_evict_inode(struct inode *inode)
186 trace_ext4_evict_inode(inode);
188 if (inode->i_nlink) {
190 * When journalling data dirty buffers are tracked only in the
191 * journal. So although mm thinks everything is clean and
192 * ready for reaping the inode might still have some pages to
193 * write in the running transaction or waiting to be
194 * checkpointed. Thus calling jbd2_journal_invalidatepage()
195 * (via truncate_inode_pages()) to discard these buffers can
196 * cause data loss. Also even if we did not discard these
197 * buffers, we would have no way to find them after the inode
198 * is reaped and thus user could see stale data if he tries to
199 * read them before the transaction is checkpointed. So be
200 * careful and force everything to disk here... We use
201 * ei->i_datasync_tid to store the newest transaction
202 * containing inode's data.
204 * Note that directories do not have this problem because they
205 * don't use page cache.
207 if (ext4_should_journal_data(inode) &&
208 (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode)) &&
209 inode->i_ino != EXT4_JOURNAL_INO) {
210 journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
211 tid_t commit_tid = EXT4_I(inode)->i_datasync_tid;
213 jbd2_complete_transaction(journal, commit_tid);
214 filemap_write_and_wait(&inode->i_data);
216 truncate_inode_pages(&inode->i_data, 0);
217 ext4_ioend_shutdown(inode);
221 if (!is_bad_inode(inode))
222 dquot_initialize(inode);
224 if (ext4_should_order_data(inode))
225 ext4_begin_ordered_truncate(inode, 0);
226 truncate_inode_pages(&inode->i_data, 0);
227 ext4_ioend_shutdown(inode);
229 if (is_bad_inode(inode))
233 * Protect us against freezing - iput() caller didn't have to have any
234 * protection against it
236 sb_start_intwrite(inode->i_sb);
237 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE,
238 ext4_blocks_for_truncate(inode)+3);
239 if (IS_ERR(handle)) {
240 ext4_std_error(inode->i_sb, PTR_ERR(handle));
242 * If we're going to skip the normal cleanup, we still need to
243 * make sure that the in-core orphan linked list is properly
246 ext4_orphan_del(NULL, inode);
247 sb_end_intwrite(inode->i_sb);
252 ext4_handle_sync(handle);
254 err = ext4_mark_inode_dirty(handle, inode);
256 ext4_warning(inode->i_sb,
257 "couldn't mark inode dirty (err %d)", err);
261 ext4_truncate(inode);
264 * ext4_ext_truncate() doesn't reserve any slop when it
265 * restarts journal transactions; therefore there may not be
266 * enough credits left in the handle to remove the inode from
267 * the orphan list and set the dtime field.
269 if (!ext4_handle_has_enough_credits(handle, 3)) {
270 err = ext4_journal_extend(handle, 3);
272 err = ext4_journal_restart(handle, 3);
274 ext4_warning(inode->i_sb,
275 "couldn't extend journal (err %d)", err);
277 ext4_journal_stop(handle);
278 ext4_orphan_del(NULL, inode);
279 sb_end_intwrite(inode->i_sb);
285 * Kill off the orphan record which ext4_truncate created.
286 * AKPM: I think this can be inside the above `if'.
287 * Note that ext4_orphan_del() has to be able to cope with the
288 * deletion of a non-existent orphan - this is because we don't
289 * know if ext4_truncate() actually created an orphan record.
290 * (Well, we could do this if we need to, but heck - it works)
292 ext4_orphan_del(handle, inode);
293 EXT4_I(inode)->i_dtime = get_seconds();
296 * One subtle ordering requirement: if anything has gone wrong
297 * (transaction abort, IO errors, whatever), then we can still
298 * do these next steps (the fs will already have been marked as
299 * having errors), but we can't free the inode if the mark_dirty
302 if (ext4_mark_inode_dirty(handle, inode))
303 /* If that failed, just do the required in-core inode clear. */
304 ext4_clear_inode(inode);
306 ext4_free_inode(handle, inode);
307 ext4_journal_stop(handle);
308 sb_end_intwrite(inode->i_sb);
311 ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
315 qsize_t *ext4_get_reserved_space(struct inode *inode)
317 return &EXT4_I(inode)->i_reserved_quota;
322 * Calculate the number of metadata blocks need to reserve
323 * to allocate a block located at @lblock
325 static int ext4_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
327 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
328 return ext4_ext_calc_metadata_amount(inode, lblock);
330 return ext4_ind_calc_metadata_amount(inode, lblock);
334 * Called with i_data_sem down, which is important since we can call
335 * ext4_discard_preallocations() from here.
337 void ext4_da_update_reserve_space(struct inode *inode,
338 int used, int quota_claim)
340 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
341 struct ext4_inode_info *ei = EXT4_I(inode);
343 spin_lock(&ei->i_block_reservation_lock);
344 trace_ext4_da_update_reserve_space(inode, used, quota_claim);
345 if (unlikely(used > ei->i_reserved_data_blocks)) {
346 ext4_warning(inode->i_sb, "%s: ino %lu, used %d "
347 "with only %d reserved data blocks",
348 __func__, inode->i_ino, used,
349 ei->i_reserved_data_blocks);
351 used = ei->i_reserved_data_blocks;
354 if (unlikely(ei->i_allocated_meta_blocks > ei->i_reserved_meta_blocks)) {
355 ext4_warning(inode->i_sb, "ino %lu, allocated %d "
356 "with only %d reserved metadata blocks "
357 "(releasing %d blocks with reserved %d data blocks)",
358 inode->i_ino, ei->i_allocated_meta_blocks,
359 ei->i_reserved_meta_blocks, used,
360 ei->i_reserved_data_blocks);
362 ei->i_allocated_meta_blocks = ei->i_reserved_meta_blocks;
365 /* Update per-inode reservations */
366 ei->i_reserved_data_blocks -= used;
367 ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks;
368 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
369 used + ei->i_allocated_meta_blocks);
370 ei->i_allocated_meta_blocks = 0;
372 if (ei->i_reserved_data_blocks == 0) {
374 * We can release all of the reserved metadata blocks
375 * only when we have written all of the delayed
378 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
379 ei->i_reserved_meta_blocks);
380 ei->i_reserved_meta_blocks = 0;
381 ei->i_da_metadata_calc_len = 0;
383 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
385 /* Update quota subsystem for data blocks */
387 dquot_claim_block(inode, EXT4_C2B(sbi, used));
390 * We did fallocate with an offset that is already delayed
391 * allocated. So on delayed allocated writeback we should
392 * not re-claim the quota for fallocated blocks.
394 dquot_release_reservation_block(inode, EXT4_C2B(sbi, used));
398 * If we have done all the pending block allocations and if
399 * there aren't any writers on the inode, we can discard the
400 * inode's preallocations.
402 if ((ei->i_reserved_data_blocks == 0) &&
403 (atomic_read(&inode->i_writecount) == 0))
404 ext4_discard_preallocations(inode);
407 static int __check_block_validity(struct inode *inode, const char *func,
409 struct ext4_map_blocks *map)
411 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
413 ext4_error_inode(inode, func, line, map->m_pblk,
414 "lblock %lu mapped to illegal pblock "
415 "(length %d)", (unsigned long) map->m_lblk,
422 #define check_block_validity(inode, map) \
423 __check_block_validity((inode), __func__, __LINE__, (map))
426 * Return the number of contiguous dirty pages in a given inode
427 * starting at page frame idx.
429 static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
430 unsigned int max_pages)
432 struct address_space *mapping = inode->i_mapping;
436 int i, nr_pages, done = 0;
440 pagevec_init(&pvec, 0);
443 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
445 (pgoff_t)PAGEVEC_SIZE);
448 for (i = 0; i < nr_pages; i++) {
449 struct page *page = pvec.pages[i];
450 struct buffer_head *bh, *head;
453 if (unlikely(page->mapping != mapping) ||
455 PageWriteback(page) ||
456 page->index != idx) {
461 if (page_has_buffers(page)) {
462 bh = head = page_buffers(page);
464 if (!buffer_delay(bh) &&
465 !buffer_unwritten(bh))
467 bh = bh->b_this_page;
468 } while (!done && (bh != head));
475 if (num >= max_pages) {
480 pagevec_release(&pvec);
485 #ifdef ES_AGGRESSIVE_TEST
486 static void ext4_map_blocks_es_recheck(handle_t *handle,
488 struct ext4_map_blocks *es_map,
489 struct ext4_map_blocks *map,
496 * There is a race window that the result is not the same.
497 * e.g. xfstests #223 when dioread_nolock enables. The reason
498 * is that we lookup a block mapping in extent status tree with
499 * out taking i_data_sem. So at the time the unwritten extent
500 * could be converted.
502 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
503 down_read((&EXT4_I(inode)->i_data_sem));
504 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
505 retval = ext4_ext_map_blocks(handle, inode, map, flags &
506 EXT4_GET_BLOCKS_KEEP_SIZE);
508 retval = ext4_ind_map_blocks(handle, inode, map, flags &
509 EXT4_GET_BLOCKS_KEEP_SIZE);
511 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
512 up_read((&EXT4_I(inode)->i_data_sem));
514 * Clear EXT4_MAP_FROM_CLUSTER and EXT4_MAP_BOUNDARY flag
515 * because it shouldn't be marked in es_map->m_flags.
517 map->m_flags &= ~(EXT4_MAP_FROM_CLUSTER | EXT4_MAP_BOUNDARY);
520 * We don't check m_len because extent will be collpased in status
521 * tree. So the m_len might not equal.
523 if (es_map->m_lblk != map->m_lblk ||
524 es_map->m_flags != map->m_flags ||
525 es_map->m_pblk != map->m_pblk) {
526 printk("ES cache assertation failed for inode: %lu "
527 "es_cached ex [%d/%d/%llu/%x] != "
528 "found ex [%d/%d/%llu/%x] retval %d flags %x\n",
529 inode->i_ino, es_map->m_lblk, es_map->m_len,
530 es_map->m_pblk, es_map->m_flags, map->m_lblk,
531 map->m_len, map->m_pblk, map->m_flags,
535 #endif /* ES_AGGRESSIVE_TEST */
538 * The ext4_map_blocks() function tries to look up the requested blocks,
539 * and returns if the blocks are already mapped.
541 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
542 * and store the allocated blocks in the result buffer head and mark it
545 * If file type is extents based, it will call ext4_ext_map_blocks(),
546 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
549 * On success, it returns the number of blocks being mapped or allocate.
550 * if create==0 and the blocks are pre-allocated and uninitialized block,
551 * the result buffer head is unmapped. If the create ==1, it will make sure
552 * the buffer head is mapped.
554 * It returns 0 if plain look up failed (blocks have not been allocated), in
555 * that case, buffer head is unmapped
557 * It returns the error in case of allocation failure.
559 int ext4_map_blocks(handle_t *handle, struct inode *inode,
560 struct ext4_map_blocks *map, int flags)
562 struct extent_status es;
564 #ifdef ES_AGGRESSIVE_TEST
565 struct ext4_map_blocks orig_map;
567 memcpy(&orig_map, map, sizeof(*map));
571 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
572 "logical block %lu\n", inode->i_ino, flags, map->m_len,
573 (unsigned long) map->m_lblk);
575 /* Lookup extent status tree firstly */
576 if (ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
577 if (ext4_es_is_written(&es) || ext4_es_is_unwritten(&es)) {
578 map->m_pblk = ext4_es_pblock(&es) +
579 map->m_lblk - es.es_lblk;
580 map->m_flags |= ext4_es_is_written(&es) ?
581 EXT4_MAP_MAPPED : EXT4_MAP_UNWRITTEN;
582 retval = es.es_len - (map->m_lblk - es.es_lblk);
583 if (retval > map->m_len)
586 } else if (ext4_es_is_delayed(&es) || ext4_es_is_hole(&es)) {
591 #ifdef ES_AGGRESSIVE_TEST
592 ext4_map_blocks_es_recheck(handle, inode, map,
599 * Try to see if we can get the block without requesting a new
602 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
603 down_read((&EXT4_I(inode)->i_data_sem));
604 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
605 retval = ext4_ext_map_blocks(handle, inode, map, flags &
606 EXT4_GET_BLOCKS_KEEP_SIZE);
608 retval = ext4_ind_map_blocks(handle, inode, map, flags &
609 EXT4_GET_BLOCKS_KEEP_SIZE);
613 unsigned long long status;
615 #ifdef ES_AGGRESSIVE_TEST
616 if (retval != map->m_len) {
617 printk("ES len assertation failed for inode: %lu "
618 "retval %d != map->m_len %d "
619 "in %s (lookup)\n", inode->i_ino, retval,
620 map->m_len, __func__);
624 status = map->m_flags & EXT4_MAP_UNWRITTEN ?
625 EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
626 if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
627 ext4_find_delalloc_range(inode, map->m_lblk,
628 map->m_lblk + map->m_len - 1))
629 status |= EXTENT_STATUS_DELAYED;
630 ret = ext4_es_insert_extent(inode, map->m_lblk,
631 map->m_len, map->m_pblk, status);
635 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
636 up_read((&EXT4_I(inode)->i_data_sem));
639 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
640 int ret = check_block_validity(inode, map);
645 /* If it is only a block(s) look up */
646 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
650 * Returns if the blocks have already allocated
652 * Note that if blocks have been preallocated
653 * ext4_ext_get_block() returns the create = 0
654 * with buffer head unmapped.
656 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
660 * Here we clear m_flags because after allocating an new extent,
661 * it will be set again.
663 map->m_flags &= ~EXT4_MAP_FLAGS;
666 * New blocks allocate and/or writing to uninitialized extent
667 * will possibly result in updating i_data, so we take
668 * the write lock of i_data_sem, and call get_blocks()
669 * with create == 1 flag.
671 down_write((&EXT4_I(inode)->i_data_sem));
674 * if the caller is from delayed allocation writeout path
675 * we have already reserved fs blocks for allocation
676 * let the underlying get_block() function know to
677 * avoid double accounting
679 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
680 ext4_set_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
682 * We need to check for EXT4 here because migrate
683 * could have changed the inode type in between
685 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
686 retval = ext4_ext_map_blocks(handle, inode, map, flags);
688 retval = ext4_ind_map_blocks(handle, inode, map, flags);
690 if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
692 * We allocated new blocks which will result in
693 * i_data's format changing. Force the migrate
694 * to fail by clearing migrate flags
696 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
700 * Update reserved blocks/metadata blocks after successful
701 * block allocation which had been deferred till now. We don't
702 * support fallocate for non extent files. So we can update
703 * reserve space here.
706 (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
707 ext4_da_update_reserve_space(inode, retval, 1);
709 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
710 ext4_clear_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
714 unsigned long long status;
716 #ifdef ES_AGGRESSIVE_TEST
717 if (retval != map->m_len) {
718 printk("ES len assertation failed for inode: %lu "
719 "retval %d != map->m_len %d "
720 "in %s (allocation)\n", inode->i_ino, retval,
721 map->m_len, __func__);
726 * If the extent has been zeroed out, we don't need to update
727 * extent status tree.
729 if ((flags & EXT4_GET_BLOCKS_PRE_IO) &&
730 ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
731 if (ext4_es_is_written(&es))
734 status = map->m_flags & EXT4_MAP_UNWRITTEN ?
735 EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
736 if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
737 ext4_find_delalloc_range(inode, map->m_lblk,
738 map->m_lblk + map->m_len - 1))
739 status |= EXTENT_STATUS_DELAYED;
740 ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
741 map->m_pblk, status);
747 up_write((&EXT4_I(inode)->i_data_sem));
748 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
749 int ret = check_block_validity(inode, map);
756 /* Maximum number of blocks we map for direct IO at once. */
757 #define DIO_MAX_BLOCKS 4096
759 static int _ext4_get_block(struct inode *inode, sector_t iblock,
760 struct buffer_head *bh, int flags)
762 handle_t *handle = ext4_journal_current_handle();
763 struct ext4_map_blocks map;
764 int ret = 0, started = 0;
767 if (ext4_has_inline_data(inode))
771 map.m_len = bh->b_size >> inode->i_blkbits;
773 if (flags && !(flags & EXT4_GET_BLOCKS_NO_LOCK) && !handle) {
774 /* Direct IO write... */
775 if (map.m_len > DIO_MAX_BLOCKS)
776 map.m_len = DIO_MAX_BLOCKS;
777 dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
778 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
780 if (IS_ERR(handle)) {
781 ret = PTR_ERR(handle);
787 ret = ext4_map_blocks(handle, inode, &map, flags);
789 map_bh(bh, inode->i_sb, map.m_pblk);
790 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
791 bh->b_size = inode->i_sb->s_blocksize * map.m_len;
795 ext4_journal_stop(handle);
799 int ext4_get_block(struct inode *inode, sector_t iblock,
800 struct buffer_head *bh, int create)
802 return _ext4_get_block(inode, iblock, bh,
803 create ? EXT4_GET_BLOCKS_CREATE : 0);
807 * `handle' can be NULL if create is zero
809 struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
810 ext4_lblk_t block, int create, int *errp)
812 struct ext4_map_blocks map;
813 struct buffer_head *bh;
816 J_ASSERT(handle != NULL || create == 0);
820 err = ext4_map_blocks(handle, inode, &map,
821 create ? EXT4_GET_BLOCKS_CREATE : 0);
823 /* ensure we send some value back into *errp */
826 if (create && err == 0)
827 err = -ENOSPC; /* should never happen */
833 bh = sb_getblk(inode->i_sb, map.m_pblk);
838 if (map.m_flags & EXT4_MAP_NEW) {
839 J_ASSERT(create != 0);
840 J_ASSERT(handle != NULL);
843 * Now that we do not always journal data, we should
844 * keep in mind whether this should always journal the
845 * new buffer as metadata. For now, regular file
846 * writes use ext4_get_block instead, so it's not a
850 BUFFER_TRACE(bh, "call get_create_access");
851 fatal = ext4_journal_get_create_access(handle, bh);
852 if (!fatal && !buffer_uptodate(bh)) {
853 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
854 set_buffer_uptodate(bh);
857 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
858 err = ext4_handle_dirty_metadata(handle, inode, bh);
862 BUFFER_TRACE(bh, "not a new buffer");
872 struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
873 ext4_lblk_t block, int create, int *err)
875 struct buffer_head *bh;
877 bh = ext4_getblk(handle, inode, block, create, err);
880 if (buffer_uptodate(bh))
882 ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh);
884 if (buffer_uptodate(bh))
891 int ext4_walk_page_buffers(handle_t *handle,
892 struct buffer_head *head,
896 int (*fn)(handle_t *handle,
897 struct buffer_head *bh))
899 struct buffer_head *bh;
900 unsigned block_start, block_end;
901 unsigned blocksize = head->b_size;
903 struct buffer_head *next;
905 for (bh = head, block_start = 0;
906 ret == 0 && (bh != head || !block_start);
907 block_start = block_end, bh = next) {
908 next = bh->b_this_page;
909 block_end = block_start + blocksize;
910 if (block_end <= from || block_start >= to) {
911 if (partial && !buffer_uptodate(bh))
915 err = (*fn)(handle, bh);
923 * To preserve ordering, it is essential that the hole instantiation and
924 * the data write be encapsulated in a single transaction. We cannot
925 * close off a transaction and start a new one between the ext4_get_block()
926 * and the commit_write(). So doing the jbd2_journal_start at the start of
927 * prepare_write() is the right place.
929 * Also, this function can nest inside ext4_writepage(). In that case, we
930 * *know* that ext4_writepage() has generated enough buffer credits to do the
931 * whole page. So we won't block on the journal in that case, which is good,
932 * because the caller may be PF_MEMALLOC.
934 * By accident, ext4 can be reentered when a transaction is open via
935 * quota file writes. If we were to commit the transaction while thus
936 * reentered, there can be a deadlock - we would be holding a quota
937 * lock, and the commit would never complete if another thread had a
938 * transaction open and was blocking on the quota lock - a ranking
941 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
942 * will _not_ run commit under these circumstances because handle->h_ref
943 * is elevated. We'll still have enough credits for the tiny quotafile
946 int do_journal_get_write_access(handle_t *handle,
947 struct buffer_head *bh)
949 int dirty = buffer_dirty(bh);
952 if (!buffer_mapped(bh) || buffer_freed(bh))
955 * __block_write_begin() could have dirtied some buffers. Clean
956 * the dirty bit as jbd2_journal_get_write_access() could complain
957 * otherwise about fs integrity issues. Setting of the dirty bit
958 * by __block_write_begin() isn't a real problem here as we clear
959 * the bit before releasing a page lock and thus writeback cannot
960 * ever write the buffer.
963 clear_buffer_dirty(bh);
964 ret = ext4_journal_get_write_access(handle, bh);
966 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
970 static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock,
971 struct buffer_head *bh_result, int create);
972 static int ext4_write_begin(struct file *file, struct address_space *mapping,
973 loff_t pos, unsigned len, unsigned flags,
974 struct page **pagep, void **fsdata)
976 struct inode *inode = mapping->host;
977 int ret, needed_blocks;
984 trace_ext4_write_begin(inode, pos, len, flags);
986 * Reserve one block more for addition to orphan list in case
987 * we allocate blocks but write fails for some reason
989 needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
990 index = pos >> PAGE_CACHE_SHIFT;
991 from = pos & (PAGE_CACHE_SIZE - 1);
994 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
995 ret = ext4_try_to_write_inline_data(mapping, inode, pos, len,
1004 * grab_cache_page_write_begin() can take a long time if the
1005 * system is thrashing due to memory pressure, or if the page
1006 * is being written back. So grab it first before we start
1007 * the transaction handle. This also allows us to allocate
1008 * the page (if needed) without using GFP_NOFS.
1011 page = grab_cache_page_write_begin(mapping, index, flags);
1017 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks);
1018 if (IS_ERR(handle)) {
1019 page_cache_release(page);
1020 return PTR_ERR(handle);
1024 if (page->mapping != mapping) {
1025 /* The page got truncated from under us */
1027 page_cache_release(page);
1028 ext4_journal_stop(handle);
1031 wait_on_page_writeback(page);
1033 if (ext4_should_dioread_nolock(inode))
1034 ret = __block_write_begin(page, pos, len, ext4_get_block_write);
1036 ret = __block_write_begin(page, pos, len, ext4_get_block);
1038 if (!ret && ext4_should_journal_data(inode)) {
1039 ret = ext4_walk_page_buffers(handle, page_buffers(page),
1041 do_journal_get_write_access);
1047 * __block_write_begin may have instantiated a few blocks
1048 * outside i_size. Trim these off again. Don't need
1049 * i_size_read because we hold i_mutex.
1051 * Add inode to orphan list in case we crash before
1054 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1055 ext4_orphan_add(handle, inode);
1057 ext4_journal_stop(handle);
1058 if (pos + len > inode->i_size) {
1059 ext4_truncate_failed_write(inode);
1061 * If truncate failed early the inode might
1062 * still be on the orphan list; we need to
1063 * make sure the inode is removed from the
1064 * orphan list in that case.
1067 ext4_orphan_del(NULL, inode);
1070 if (ret == -ENOSPC &&
1071 ext4_should_retry_alloc(inode->i_sb, &retries))
1073 page_cache_release(page);
1080 /* For write_end() in data=journal mode */
1081 static int write_end_fn(handle_t *handle, struct buffer_head *bh)
1083 if (!buffer_mapped(bh) || buffer_freed(bh))
1085 set_buffer_uptodate(bh);
1086 return ext4_handle_dirty_metadata(handle, NULL, bh);
1090 * We need to pick up the new inode size which generic_commit_write gave us
1091 * `file' can be NULL - eg, when called from page_symlink().
1093 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1094 * buffers are managed internally.
1096 static int ext4_write_end(struct file *file,
1097 struct address_space *mapping,
1098 loff_t pos, unsigned len, unsigned copied,
1099 struct page *page, void *fsdata)
1101 handle_t *handle = ext4_journal_current_handle();
1102 struct inode *inode = mapping->host;
1104 int i_size_changed = 0;
1106 trace_ext4_write_end(inode, pos, len, copied);
1107 if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE)) {
1108 ret = ext4_jbd2_file_inode(handle, inode);
1111 page_cache_release(page);
1116 if (ext4_has_inline_data(inode))
1117 copied = ext4_write_inline_data_end(inode, pos, len,
1120 copied = block_write_end(file, mapping, pos,
1121 len, copied, page, fsdata);
1124 * No need to use i_size_read() here, the i_size
1125 * cannot change under us because we hole i_mutex.
1127 * But it's important to update i_size while still holding page lock:
1128 * page writeout could otherwise come in and zero beyond i_size.
1130 if (pos + copied > inode->i_size) {
1131 i_size_write(inode, pos + copied);
1135 if (pos + copied > EXT4_I(inode)->i_disksize) {
1136 /* We need to mark inode dirty even if
1137 * new_i_size is less that inode->i_size
1138 * but greater than i_disksize. (hint delalloc)
1140 ext4_update_i_disksize(inode, (pos + copied));
1144 page_cache_release(page);
1147 * Don't mark the inode dirty under page lock. First, it unnecessarily
1148 * makes the holding time of page lock longer. Second, it forces lock
1149 * ordering of page lock and transaction start for journaling
1153 ext4_mark_inode_dirty(handle, inode);
1157 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1158 /* if we have allocated more blocks and copied
1159 * less. We will have blocks allocated outside
1160 * inode->i_size. So truncate them
1162 ext4_orphan_add(handle, inode);
1164 ret2 = ext4_journal_stop(handle);
1168 if (pos + len > inode->i_size) {
1169 ext4_truncate_failed_write(inode);
1171 * If truncate failed early the inode might still be
1172 * on the orphan list; we need to make sure the inode
1173 * is removed from the orphan list in that case.
1176 ext4_orphan_del(NULL, inode);
1179 return ret ? ret : copied;
1182 static int ext4_journalled_write_end(struct file *file,
1183 struct address_space *mapping,
1184 loff_t pos, unsigned len, unsigned copied,
1185 struct page *page, void *fsdata)
1187 handle_t *handle = ext4_journal_current_handle();
1188 struct inode *inode = mapping->host;
1194 trace_ext4_journalled_write_end(inode, pos, len, copied);
1195 from = pos & (PAGE_CACHE_SIZE - 1);
1198 BUG_ON(!ext4_handle_valid(handle));
1200 if (ext4_has_inline_data(inode))
1201 copied = ext4_write_inline_data_end(inode, pos, len,
1205 if (!PageUptodate(page))
1207 page_zero_new_buffers(page, from+copied, to);
1210 ret = ext4_walk_page_buffers(handle, page_buffers(page), from,
1211 to, &partial, write_end_fn);
1213 SetPageUptodate(page);
1215 new_i_size = pos + copied;
1216 if (new_i_size > inode->i_size)
1217 i_size_write(inode, pos+copied);
1218 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1219 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1220 if (new_i_size > EXT4_I(inode)->i_disksize) {
1221 ext4_update_i_disksize(inode, new_i_size);
1222 ret2 = ext4_mark_inode_dirty(handle, inode);
1228 page_cache_release(page);
1229 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1230 /* if we have allocated more blocks and copied
1231 * less. We will have blocks allocated outside
1232 * inode->i_size. So truncate them
1234 ext4_orphan_add(handle, inode);
1236 ret2 = ext4_journal_stop(handle);
1239 if (pos + len > inode->i_size) {
1240 ext4_truncate_failed_write(inode);
1242 * If truncate failed early the inode might still be
1243 * on the orphan list; we need to make sure the inode
1244 * is removed from the orphan list in that case.
1247 ext4_orphan_del(NULL, inode);
1250 return ret ? ret : copied;
1254 * Reserve a metadata for a single block located at lblock
1256 static int ext4_da_reserve_metadata(struct inode *inode, ext4_lblk_t lblock)
1259 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1260 struct ext4_inode_info *ei = EXT4_I(inode);
1261 unsigned int md_needed;
1262 ext4_lblk_t save_last_lblock;
1266 * recalculate the amount of metadata blocks to reserve
1267 * in order to allocate nrblocks
1268 * worse case is one extent per block
1271 spin_lock(&ei->i_block_reservation_lock);
1273 * ext4_calc_metadata_amount() has side effects, which we have
1274 * to be prepared undo if we fail to claim space.
1276 save_len = ei->i_da_metadata_calc_len;
1277 save_last_lblock = ei->i_da_metadata_calc_last_lblock;
1278 md_needed = EXT4_NUM_B2C(sbi,
1279 ext4_calc_metadata_amount(inode, lblock));
1280 trace_ext4_da_reserve_space(inode, md_needed);
1283 * We do still charge estimated metadata to the sb though;
1284 * we cannot afford to run out of free blocks.
1286 if (ext4_claim_free_clusters(sbi, md_needed, 0)) {
1287 ei->i_da_metadata_calc_len = save_len;
1288 ei->i_da_metadata_calc_last_lblock = save_last_lblock;
1289 spin_unlock(&ei->i_block_reservation_lock);
1290 if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
1296 ei->i_reserved_meta_blocks += md_needed;
1297 spin_unlock(&ei->i_block_reservation_lock);
1299 return 0; /* success */
1303 * Reserve a single cluster located at lblock
1305 static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock)
1308 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1309 struct ext4_inode_info *ei = EXT4_I(inode);
1310 unsigned int md_needed;
1312 ext4_lblk_t save_last_lblock;
1316 * We will charge metadata quota at writeout time; this saves
1317 * us from metadata over-estimation, though we may go over by
1318 * a small amount in the end. Here we just reserve for data.
1320 ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1));
1325 * recalculate the amount of metadata blocks to reserve
1326 * in order to allocate nrblocks
1327 * worse case is one extent per block
1330 spin_lock(&ei->i_block_reservation_lock);
1332 * ext4_calc_metadata_amount() has side effects, which we have
1333 * to be prepared undo if we fail to claim space.
1335 save_len = ei->i_da_metadata_calc_len;
1336 save_last_lblock = ei->i_da_metadata_calc_last_lblock;
1337 md_needed = EXT4_NUM_B2C(sbi,
1338 ext4_calc_metadata_amount(inode, lblock));
1339 trace_ext4_da_reserve_space(inode, md_needed);
1342 * We do still charge estimated metadata to the sb though;
1343 * we cannot afford to run out of free blocks.
1345 if (ext4_claim_free_clusters(sbi, md_needed + 1, 0)) {
1346 ei->i_da_metadata_calc_len = save_len;
1347 ei->i_da_metadata_calc_last_lblock = save_last_lblock;
1348 spin_unlock(&ei->i_block_reservation_lock);
1349 if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
1353 dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
1356 ei->i_reserved_data_blocks++;
1357 ei->i_reserved_meta_blocks += md_needed;
1358 spin_unlock(&ei->i_block_reservation_lock);
1360 return 0; /* success */
1363 static void ext4_da_release_space(struct inode *inode, int to_free)
1365 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1366 struct ext4_inode_info *ei = EXT4_I(inode);
1369 return; /* Nothing to release, exit */
1371 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1373 trace_ext4_da_release_space(inode, to_free);
1374 if (unlikely(to_free > ei->i_reserved_data_blocks)) {
1376 * if there aren't enough reserved blocks, then the
1377 * counter is messed up somewhere. Since this
1378 * function is called from invalidate page, it's
1379 * harmless to return without any action.
1381 ext4_warning(inode->i_sb, "ext4_da_release_space: "
1382 "ino %lu, to_free %d with only %d reserved "
1383 "data blocks", inode->i_ino, to_free,
1384 ei->i_reserved_data_blocks);
1386 to_free = ei->i_reserved_data_blocks;
1388 ei->i_reserved_data_blocks -= to_free;
1390 if (ei->i_reserved_data_blocks == 0) {
1392 * We can release all of the reserved metadata blocks
1393 * only when we have written all of the delayed
1394 * allocation blocks.
1395 * Note that in case of bigalloc, i_reserved_meta_blocks,
1396 * i_reserved_data_blocks, etc. refer to number of clusters.
1398 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
1399 ei->i_reserved_meta_blocks);
1400 ei->i_reserved_meta_blocks = 0;
1401 ei->i_da_metadata_calc_len = 0;
1404 /* update fs dirty data blocks counter */
1405 percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free);
1407 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1409 dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free));
1412 static void ext4_da_page_release_reservation(struct page *page,
1413 unsigned long offset)
1416 struct buffer_head *head, *bh;
1417 unsigned int curr_off = 0;
1418 struct inode *inode = page->mapping->host;
1419 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1423 head = page_buffers(page);
1426 unsigned int next_off = curr_off + bh->b_size;
1428 if ((offset <= curr_off) && (buffer_delay(bh))) {
1430 clear_buffer_delay(bh);
1432 curr_off = next_off;
1433 } while ((bh = bh->b_this_page) != head);
1436 lblk = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1437 ext4_es_remove_extent(inode, lblk, to_release);
1440 /* If we have released all the blocks belonging to a cluster, then we
1441 * need to release the reserved space for that cluster. */
1442 num_clusters = EXT4_NUM_B2C(sbi, to_release);
1443 while (num_clusters > 0) {
1444 lblk = (page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits)) +
1445 ((num_clusters - 1) << sbi->s_cluster_bits);
1446 if (sbi->s_cluster_ratio == 1 ||
1447 !ext4_find_delalloc_cluster(inode, lblk))
1448 ext4_da_release_space(inode, 1);
1455 * Delayed allocation stuff
1459 * mpage_da_submit_io - walks through extent of pages and try to write
1460 * them with writepage() call back
1462 * @mpd->inode: inode
1463 * @mpd->first_page: first page of the extent
1464 * @mpd->next_page: page after the last page of the extent
1466 * By the time mpage_da_submit_io() is called we expect all blocks
1467 * to be allocated. this may be wrong if allocation failed.
1469 * As pages are already locked by write_cache_pages(), we can't use it
1471 static int mpage_da_submit_io(struct mpage_da_data *mpd,
1472 struct ext4_map_blocks *map)
1474 struct pagevec pvec;
1475 unsigned long index, end;
1476 int ret = 0, err, nr_pages, i;
1477 struct inode *inode = mpd->inode;
1478 struct address_space *mapping = inode->i_mapping;
1479 loff_t size = i_size_read(inode);
1480 unsigned int len, block_start;
1481 struct buffer_head *bh, *page_bufs = NULL;
1482 sector_t pblock = 0, cur_logical = 0;
1483 struct ext4_io_submit io_submit;
1485 BUG_ON(mpd->next_page <= mpd->first_page);
1486 memset(&io_submit, 0, sizeof(io_submit));
1488 * We need to start from the first_page to the next_page - 1
1489 * to make sure we also write the mapped dirty buffer_heads.
1490 * If we look at mpd->b_blocknr we would only be looking
1491 * at the currently mapped buffer_heads.
1493 index = mpd->first_page;
1494 end = mpd->next_page - 1;
1496 pagevec_init(&pvec, 0);
1497 while (index <= end) {
1498 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
1501 for (i = 0; i < nr_pages; i++) {
1503 struct page *page = pvec.pages[i];
1505 index = page->index;
1509 if (index == size >> PAGE_CACHE_SHIFT)
1510 len = size & ~PAGE_CACHE_MASK;
1512 len = PAGE_CACHE_SIZE;
1514 cur_logical = index << (PAGE_CACHE_SHIFT -
1516 pblock = map->m_pblk + (cur_logical -
1521 BUG_ON(!PageLocked(page));
1522 BUG_ON(PageWriteback(page));
1524 bh = page_bufs = page_buffers(page);
1527 if (map && (cur_logical >= map->m_lblk) &&
1528 (cur_logical <= (map->m_lblk +
1529 (map->m_len - 1)))) {
1530 if (buffer_delay(bh)) {
1531 clear_buffer_delay(bh);
1532 bh->b_blocknr = pblock;
1534 if (buffer_unwritten(bh) ||
1536 BUG_ON(bh->b_blocknr != pblock);
1537 if (map->m_flags & EXT4_MAP_UNINIT)
1538 set_buffer_uninit(bh);
1539 clear_buffer_unwritten(bh);
1543 * skip page if block allocation undone and
1546 if (ext4_bh_delay_or_unwritten(NULL, bh))
1548 bh = bh->b_this_page;
1549 block_start += bh->b_size;
1552 } while (bh != page_bufs);
1559 clear_page_dirty_for_io(page);
1560 err = ext4_bio_write_page(&io_submit, page, len,
1563 mpd->pages_written++;
1565 * In error case, we have to continue because
1566 * remaining pages are still locked
1571 pagevec_release(&pvec);
1573 ext4_io_submit(&io_submit);
1577 static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd)
1581 struct pagevec pvec;
1582 struct inode *inode = mpd->inode;
1583 struct address_space *mapping = inode->i_mapping;
1584 ext4_lblk_t start, last;
1586 index = mpd->first_page;
1587 end = mpd->next_page - 1;
1589 start = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1590 last = end << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1591 ext4_es_remove_extent(inode, start, last - start + 1);
1593 pagevec_init(&pvec, 0);
1594 while (index <= end) {
1595 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
1598 for (i = 0; i < nr_pages; i++) {
1599 struct page *page = pvec.pages[i];
1600 if (page->index > end)
1602 BUG_ON(!PageLocked(page));
1603 BUG_ON(PageWriteback(page));
1604 block_invalidatepage(page, 0);
1605 ClearPageUptodate(page);
1608 index = pvec.pages[nr_pages - 1]->index + 1;
1609 pagevec_release(&pvec);
1614 static void ext4_print_free_blocks(struct inode *inode)
1616 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1617 struct super_block *sb = inode->i_sb;
1619 ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld",
1620 EXT4_C2B(EXT4_SB(inode->i_sb),
1621 ext4_count_free_clusters(inode->i_sb)));
1622 ext4_msg(sb, KERN_CRIT, "Free/Dirty block details");
1623 ext4_msg(sb, KERN_CRIT, "free_blocks=%lld",
1624 (long long) EXT4_C2B(EXT4_SB(inode->i_sb),
1625 percpu_counter_sum(&sbi->s_freeclusters_counter)));
1626 ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld",
1627 (long long) EXT4_C2B(EXT4_SB(inode->i_sb),
1628 percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
1629 ext4_msg(sb, KERN_CRIT, "Block reservation details");
1630 ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u",
1631 EXT4_I(inode)->i_reserved_data_blocks);
1632 ext4_msg(sb, KERN_CRIT, "i_reserved_meta_blocks=%u",
1633 EXT4_I(inode)->i_reserved_meta_blocks);
1638 * mpage_da_map_and_submit - go through given space, map them
1639 * if necessary, and then submit them for I/O
1641 * @mpd - bh describing space
1643 * The function skips space we know is already mapped to disk blocks.
1646 static void mpage_da_map_and_submit(struct mpage_da_data *mpd)
1648 int err, blks, get_blocks_flags;
1649 struct ext4_map_blocks map, *mapp = NULL;
1650 sector_t next = mpd->b_blocknr;
1651 unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits;
1652 loff_t disksize = EXT4_I(mpd->inode)->i_disksize;
1653 handle_t *handle = NULL;
1656 * If the blocks are mapped already, or we couldn't accumulate
1657 * any blocks, then proceed immediately to the submission stage.
1659 if ((mpd->b_size == 0) ||
1660 ((mpd->b_state & (1 << BH_Mapped)) &&
1661 !(mpd->b_state & (1 << BH_Delay)) &&
1662 !(mpd->b_state & (1 << BH_Unwritten))))
1665 handle = ext4_journal_current_handle();
1669 * Call ext4_map_blocks() to allocate any delayed allocation
1670 * blocks, or to convert an uninitialized extent to be
1671 * initialized (in the case where we have written into
1672 * one or more preallocated blocks).
1674 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
1675 * indicate that we are on the delayed allocation path. This
1676 * affects functions in many different parts of the allocation
1677 * call path. This flag exists primarily because we don't
1678 * want to change *many* call functions, so ext4_map_blocks()
1679 * will set the EXT4_STATE_DELALLOC_RESERVED flag once the
1680 * inode's allocation semaphore is taken.
1682 * If the blocks in questions were delalloc blocks, set
1683 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
1684 * variables are updated after the blocks have been allocated.
1687 map.m_len = max_blocks;
1688 get_blocks_flags = EXT4_GET_BLOCKS_CREATE;
1689 if (ext4_should_dioread_nolock(mpd->inode))
1690 get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
1691 if (mpd->b_state & (1 << BH_Delay))
1692 get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
1694 blks = ext4_map_blocks(handle, mpd->inode, &map, get_blocks_flags);
1696 struct super_block *sb = mpd->inode->i_sb;
1700 * If get block returns EAGAIN or ENOSPC and there
1701 * appears to be free blocks we will just let
1702 * mpage_da_submit_io() unlock all of the pages.
1707 if (err == -ENOSPC && ext4_count_free_clusters(sb)) {
1713 * get block failure will cause us to loop in
1714 * writepages, because a_ops->writepage won't be able
1715 * to make progress. The page will be redirtied by
1716 * writepage and writepages will again try to write
1719 if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) {
1720 ext4_msg(sb, KERN_CRIT,
1721 "delayed block allocation failed for inode %lu "
1722 "at logical offset %llu with max blocks %zd "
1723 "with error %d", mpd->inode->i_ino,
1724 (unsigned long long) next,
1725 mpd->b_size >> mpd->inode->i_blkbits, err);
1726 ext4_msg(sb, KERN_CRIT,
1727 "This should not happen!! Data will be lost");
1729 ext4_print_free_blocks(mpd->inode);
1731 /* invalidate all the pages */
1732 ext4_da_block_invalidatepages(mpd);
1734 /* Mark this page range as having been completed */
1741 if (map.m_flags & EXT4_MAP_NEW) {
1742 struct block_device *bdev = mpd->inode->i_sb->s_bdev;
1745 for (i = 0; i < map.m_len; i++)
1746 unmap_underlying_metadata(bdev, map.m_pblk + i);
1750 * Update on-disk size along with block allocation.
1752 disksize = ((loff_t) next + blks) << mpd->inode->i_blkbits;
1753 if (disksize > i_size_read(mpd->inode))
1754 disksize = i_size_read(mpd->inode);
1755 if (disksize > EXT4_I(mpd->inode)->i_disksize) {
1756 ext4_update_i_disksize(mpd->inode, disksize);
1757 err = ext4_mark_inode_dirty(handle, mpd->inode);
1759 ext4_error(mpd->inode->i_sb,
1760 "Failed to mark inode %lu dirty",
1765 mpage_da_submit_io(mpd, mapp);
1769 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
1770 (1 << BH_Delay) | (1 << BH_Unwritten))
1773 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
1775 * @mpd->lbh - extent of blocks
1776 * @logical - logical number of the block in the file
1777 * @b_state - b_state of the buffer head added
1779 * the function is used to collect contig. blocks in same state
1781 static void mpage_add_bh_to_extent(struct mpage_da_data *mpd, sector_t logical,
1782 unsigned long b_state)
1785 int blkbits = mpd->inode->i_blkbits;
1786 int nrblocks = mpd->b_size >> blkbits;
1789 * XXX Don't go larger than mballoc is willing to allocate
1790 * This is a stopgap solution. We eventually need to fold
1791 * mpage_da_submit_io() into this function and then call
1792 * ext4_map_blocks() multiple times in a loop
1794 if (nrblocks >= (8*1024*1024 >> blkbits))
1797 /* check if the reserved journal credits might overflow */
1798 if (!ext4_test_inode_flag(mpd->inode, EXT4_INODE_EXTENTS)) {
1799 if (nrblocks >= EXT4_MAX_TRANS_DATA) {
1801 * With non-extent format we are limited by the journal
1802 * credit available. Total credit needed to insert
1803 * nrblocks contiguous blocks is dependent on the
1804 * nrblocks. So limit nrblocks.
1810 * First block in the extent
1812 if (mpd->b_size == 0) {
1813 mpd->b_blocknr = logical;
1814 mpd->b_size = 1 << blkbits;
1815 mpd->b_state = b_state & BH_FLAGS;
1819 next = mpd->b_blocknr + nrblocks;
1821 * Can we merge the block to our big extent?
1823 if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
1824 mpd->b_size += 1 << blkbits;
1830 * We couldn't merge the block to our extent, so we
1831 * need to flush current extent and start new one
1833 mpage_da_map_and_submit(mpd);
1837 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
1839 return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
1843 * This function is grabs code from the very beginning of
1844 * ext4_map_blocks, but assumes that the caller is from delayed write
1845 * time. This function looks up the requested blocks and sets the
1846 * buffer delay bit under the protection of i_data_sem.
1848 static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
1849 struct ext4_map_blocks *map,
1850 struct buffer_head *bh)
1852 struct extent_status es;
1854 sector_t invalid_block = ~((sector_t) 0xffff);
1855 #ifdef ES_AGGRESSIVE_TEST
1856 struct ext4_map_blocks orig_map;
1858 memcpy(&orig_map, map, sizeof(*map));
1861 if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
1865 ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u,"
1866 "logical block %lu\n", inode->i_ino, map->m_len,
1867 (unsigned long) map->m_lblk);
1869 /* Lookup extent status tree firstly */
1870 if (ext4_es_lookup_extent(inode, iblock, &es)) {
1872 if (ext4_es_is_hole(&es)) {
1874 down_read((&EXT4_I(inode)->i_data_sem));
1879 * Delayed extent could be allocated by fallocate.
1880 * So we need to check it.
1882 if (ext4_es_is_delayed(&es) && !ext4_es_is_unwritten(&es)) {
1883 map_bh(bh, inode->i_sb, invalid_block);
1885 set_buffer_delay(bh);
1889 map->m_pblk = ext4_es_pblock(&es) + iblock - es.es_lblk;
1890 retval = es.es_len - (iblock - es.es_lblk);
1891 if (retval > map->m_len)
1892 retval = map->m_len;
1893 map->m_len = retval;
1894 if (ext4_es_is_written(&es))
1895 map->m_flags |= EXT4_MAP_MAPPED;
1896 else if (ext4_es_is_unwritten(&es))
1897 map->m_flags |= EXT4_MAP_UNWRITTEN;
1901 #ifdef ES_AGGRESSIVE_TEST
1902 ext4_map_blocks_es_recheck(NULL, inode, map, &orig_map, 0);
1908 * Try to see if we can get the block without requesting a new
1909 * file system block.
1911 down_read((&EXT4_I(inode)->i_data_sem));
1912 if (ext4_has_inline_data(inode)) {
1914 * We will soon create blocks for this page, and let
1915 * us pretend as if the blocks aren't allocated yet.
1916 * In case of clusters, we have to handle the work
1917 * of mapping from cluster so that the reserved space
1918 * is calculated properly.
1920 if ((EXT4_SB(inode->i_sb)->s_cluster_ratio > 1) &&
1921 ext4_find_delalloc_cluster(inode, map->m_lblk))
1922 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
1924 } else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
1925 retval = ext4_ext_map_blocks(NULL, inode, map,
1926 EXT4_GET_BLOCKS_NO_PUT_HOLE);
1928 retval = ext4_ind_map_blocks(NULL, inode, map,
1929 EXT4_GET_BLOCKS_NO_PUT_HOLE);
1935 * XXX: __block_prepare_write() unmaps passed block,
1939 * If the block was allocated from previously allocated cluster,
1940 * then we don't need to reserve it again. However we still need
1941 * to reserve metadata for every block we're going to write.
1943 if (!(map->m_flags & EXT4_MAP_FROM_CLUSTER)) {
1944 ret = ext4_da_reserve_space(inode, iblock);
1946 /* not enough space to reserve */
1951 ret = ext4_da_reserve_metadata(inode, iblock);
1953 /* not enough space to reserve */
1959 ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
1960 ~0, EXTENT_STATUS_DELAYED);
1966 /* Clear EXT4_MAP_FROM_CLUSTER flag since its purpose is served
1967 * and it should not appear on the bh->b_state.
1969 map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
1971 map_bh(bh, inode->i_sb, invalid_block);
1973 set_buffer_delay(bh);
1974 } else if (retval > 0) {
1976 unsigned long long status;
1978 #ifdef ES_AGGRESSIVE_TEST
1979 if (retval != map->m_len) {
1980 printk("ES len assertation failed for inode: %lu "
1981 "retval %d != map->m_len %d "
1982 "in %s (lookup)\n", inode->i_ino, retval,
1983 map->m_len, __func__);
1987 status = map->m_flags & EXT4_MAP_UNWRITTEN ?
1988 EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
1989 ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
1990 map->m_pblk, status);
1996 up_read((&EXT4_I(inode)->i_data_sem));
2002 * This is a special get_blocks_t callback which is used by
2003 * ext4_da_write_begin(). It will either return mapped block or
2004 * reserve space for a single block.
2006 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
2007 * We also have b_blocknr = -1 and b_bdev initialized properly
2009 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
2010 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
2011 * initialized properly.
2013 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2014 struct buffer_head *bh, int create)
2016 struct ext4_map_blocks map;
2019 BUG_ON(create == 0);
2020 BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
2022 map.m_lblk = iblock;
2026 * first, we need to know whether the block is allocated already
2027 * preallocated blocks are unmapped but should treated
2028 * the same as allocated blocks.
2030 ret = ext4_da_map_blocks(inode, iblock, &map, bh);
2034 map_bh(bh, inode->i_sb, map.m_pblk);
2035 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
2037 if (buffer_unwritten(bh)) {
2038 /* A delayed write to unwritten bh should be marked
2039 * new and mapped. Mapped ensures that we don't do
2040 * get_block multiple times when we write to the same
2041 * offset and new ensures that we do proper zero out
2042 * for partial write.
2045 set_buffer_mapped(bh);
2050 static int bget_one(handle_t *handle, struct buffer_head *bh)
2056 static int bput_one(handle_t *handle, struct buffer_head *bh)
2062 static int __ext4_journalled_writepage(struct page *page,
2065 struct address_space *mapping = page->mapping;
2066 struct inode *inode = mapping->host;
2067 struct buffer_head *page_bufs = NULL;
2068 handle_t *handle = NULL;
2069 int ret = 0, err = 0;
2070 int inline_data = ext4_has_inline_data(inode);
2071 struct buffer_head *inode_bh = NULL;
2073 ClearPageChecked(page);
2076 BUG_ON(page->index != 0);
2077 BUG_ON(len > ext4_get_max_inline_size(inode));
2078 inode_bh = ext4_journalled_write_inline_data(inode, len, page);
2079 if (inode_bh == NULL)
2082 page_bufs = page_buffers(page);
2087 ext4_walk_page_buffers(handle, page_bufs, 0, len,
2090 /* As soon as we unlock the page, it can go away, but we have
2091 * references to buffers so we are safe */
2094 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
2095 ext4_writepage_trans_blocks(inode));
2096 if (IS_ERR(handle)) {
2097 ret = PTR_ERR(handle);
2101 BUG_ON(!ext4_handle_valid(handle));
2104 ret = ext4_journal_get_write_access(handle, inode_bh);
2106 err = ext4_handle_dirty_metadata(handle, inode, inode_bh);
2109 ret = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
2110 do_journal_get_write_access);
2112 err = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
2117 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
2118 err = ext4_journal_stop(handle);
2122 if (!ext4_has_inline_data(inode))
2123 ext4_walk_page_buffers(handle, page_bufs, 0, len,
2125 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
2132 * Note that we don't need to start a transaction unless we're journaling data
2133 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2134 * need to file the inode to the transaction's list in ordered mode because if
2135 * we are writing back data added by write(), the inode is already there and if
2136 * we are writing back data modified via mmap(), no one guarantees in which
2137 * transaction the data will hit the disk. In case we are journaling data, we
2138 * cannot start transaction directly because transaction start ranks above page
2139 * lock so we have to do some magic.
2141 * This function can get called via...
2142 * - ext4_da_writepages after taking page lock (have journal handle)
2143 * - journal_submit_inode_data_buffers (no journal handle)
2144 * - shrink_page_list via the kswapd/direct reclaim (no journal handle)
2145 * - grab_page_cache when doing write_begin (have journal handle)
2147 * We don't do any block allocation in this function. If we have page with
2148 * multiple blocks we need to write those buffer_heads that are mapped. This
2149 * is important for mmaped based write. So if we do with blocksize 1K
2150 * truncate(f, 1024);
2151 * a = mmap(f, 0, 4096);
2153 * truncate(f, 4096);
2154 * we have in the page first buffer_head mapped via page_mkwrite call back
2155 * but other buffer_heads would be unmapped but dirty (dirty done via the
2156 * do_wp_page). So writepage should write the first block. If we modify
2157 * the mmap area beyond 1024 we will again get a page_fault and the
2158 * page_mkwrite callback will do the block allocation and mark the
2159 * buffer_heads mapped.
2161 * We redirty the page if we have any buffer_heads that is either delay or
2162 * unwritten in the page.
2164 * We can get recursively called as show below.
2166 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2169 * But since we don't do any block allocation we should not deadlock.
2170 * Page also have the dirty flag cleared so we don't get recurive page_lock.
2172 static int ext4_writepage(struct page *page,
2173 struct writeback_control *wbc)
2178 struct buffer_head *page_bufs = NULL;
2179 struct inode *inode = page->mapping->host;
2180 struct ext4_io_submit io_submit;
2182 trace_ext4_writepage(page);
2183 size = i_size_read(inode);
2184 if (page->index == size >> PAGE_CACHE_SHIFT)
2185 len = size & ~PAGE_CACHE_MASK;
2187 len = PAGE_CACHE_SIZE;
2189 page_bufs = page_buffers(page);
2191 * We cannot do block allocation or other extent handling in this
2192 * function. If there are buffers needing that, we have to redirty
2193 * the page. But we may reach here when we do a journal commit via
2194 * journal_submit_inode_data_buffers() and in that case we must write
2195 * allocated buffers to achieve data=ordered mode guarantees.
2197 if (ext4_walk_page_buffers(NULL, page_bufs, 0, len, NULL,
2198 ext4_bh_delay_or_unwritten)) {
2199 redirty_page_for_writepage(wbc, page);
2200 if (current->flags & PF_MEMALLOC) {
2202 * For memory cleaning there's no point in writing only
2203 * some buffers. So just bail out. Warn if we came here
2204 * from direct reclaim.
2206 WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD))
2213 if (PageChecked(page) && ext4_should_journal_data(inode))
2215 * It's mmapped pagecache. Add buffers and journal it. There
2216 * doesn't seem much point in redirtying the page here.
2218 return __ext4_journalled_writepage(page, len);
2220 memset(&io_submit, 0, sizeof(io_submit));
2221 ret = ext4_bio_write_page(&io_submit, page, len, wbc);
2222 ext4_io_submit(&io_submit);
2227 * This is called via ext4_da_writepages() to
2228 * calculate the total number of credits to reserve to fit
2229 * a single extent allocation into a single transaction,
2230 * ext4_da_writpeages() will loop calling this before
2231 * the block allocation.
2234 static int ext4_da_writepages_trans_blocks(struct inode *inode)
2236 int max_blocks = EXT4_I(inode)->i_reserved_data_blocks;
2239 * With non-extent format the journal credit needed to
2240 * insert nrblocks contiguous block is dependent on
2241 * number of contiguous block. So we will limit
2242 * number of contiguous block to a sane value
2244 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) &&
2245 (max_blocks > EXT4_MAX_TRANS_DATA))
2246 max_blocks = EXT4_MAX_TRANS_DATA;
2248 return ext4_chunk_trans_blocks(inode, max_blocks);
2252 * write_cache_pages_da - walk the list of dirty pages of the given
2253 * address space and accumulate pages that need writing, and call
2254 * mpage_da_map_and_submit to map a single contiguous memory region
2255 * and then write them.
2257 static int write_cache_pages_da(handle_t *handle,
2258 struct address_space *mapping,
2259 struct writeback_control *wbc,
2260 struct mpage_da_data *mpd,
2261 pgoff_t *done_index)
2263 struct buffer_head *bh, *head;
2264 struct inode *inode = mapping->host;
2265 struct pagevec pvec;
2266 unsigned int nr_pages;
2269 long nr_to_write = wbc->nr_to_write;
2270 int i, tag, ret = 0;
2272 memset(mpd, 0, sizeof(struct mpage_da_data));
2275 pagevec_init(&pvec, 0);
2276 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2277 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2279 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2280 tag = PAGECACHE_TAG_TOWRITE;
2282 tag = PAGECACHE_TAG_DIRTY;
2284 *done_index = index;
2285 while (index <= end) {
2286 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
2287 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
2291 for (i = 0; i < nr_pages; i++) {
2292 struct page *page = pvec.pages[i];
2295 * At this point, the page may be truncated or
2296 * invalidated (changing page->mapping to NULL), or
2297 * even swizzled back from swapper_space to tmpfs file
2298 * mapping. However, page->index will not change
2299 * because we have a reference on the page.
2301 if (page->index > end)
2304 *done_index = page->index + 1;
2307 * If we can't merge this page, and we have
2308 * accumulated an contiguous region, write it
2310 if ((mpd->next_page != page->index) &&
2311 (mpd->next_page != mpd->first_page)) {
2312 mpage_da_map_and_submit(mpd);
2313 goto ret_extent_tail;
2319 * If the page is no longer dirty, or its
2320 * mapping no longer corresponds to inode we
2321 * are writing (which means it has been
2322 * truncated or invalidated), or the page is
2323 * already under writeback and we are not
2324 * doing a data integrity writeback, skip the page
2326 if (!PageDirty(page) ||
2327 (PageWriteback(page) &&
2328 (wbc->sync_mode == WB_SYNC_NONE)) ||
2329 unlikely(page->mapping != mapping)) {
2334 wait_on_page_writeback(page);
2335 BUG_ON(PageWriteback(page));
2338 * If we have inline data and arrive here, it means that
2339 * we will soon create the block for the 1st page, so
2340 * we'd better clear the inline data here.
2342 if (ext4_has_inline_data(inode)) {
2343 BUG_ON(ext4_test_inode_state(inode,
2344 EXT4_STATE_MAY_INLINE_DATA));
2345 ext4_destroy_inline_data(handle, inode);
2348 if (mpd->next_page != page->index)
2349 mpd->first_page = page->index;
2350 mpd->next_page = page->index + 1;
2351 logical = (sector_t) page->index <<
2352 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2354 /* Add all dirty buffers to mpd */
2355 head = page_buffers(page);
2358 BUG_ON(buffer_locked(bh));
2360 * We need to try to allocate unmapped blocks
2361 * in the same page. Otherwise we won't make
2362 * progress with the page in ext4_writepage
2364 if (ext4_bh_delay_or_unwritten(NULL, bh)) {
2365 mpage_add_bh_to_extent(mpd, logical,
2368 goto ret_extent_tail;
2369 } else if (buffer_dirty(bh) &&
2370 buffer_mapped(bh)) {
2372 * mapped dirty buffer. We need to
2373 * update the b_state because we look
2374 * at b_state in mpage_da_map_blocks.
2375 * We don't update b_size because if we
2376 * find an unmapped buffer_head later
2377 * we need to use the b_state flag of
2380 if (mpd->b_size == 0)
2382 bh->b_state & BH_FLAGS;
2385 } while ((bh = bh->b_this_page) != head);
2387 if (nr_to_write > 0) {
2389 if (nr_to_write == 0 &&
2390 wbc->sync_mode == WB_SYNC_NONE)
2392 * We stop writing back only if we are
2393 * not doing integrity sync. In case of
2394 * integrity sync we have to keep going
2395 * because someone may be concurrently
2396 * dirtying pages, and we might have
2397 * synced a lot of newly appeared dirty
2398 * pages, but have not synced all of the
2404 pagevec_release(&pvec);
2409 ret = MPAGE_DA_EXTENT_TAIL;
2411 pagevec_release(&pvec);
2417 static int ext4_da_writepages(struct address_space *mapping,
2418 struct writeback_control *wbc)
2421 int range_whole = 0;
2422 handle_t *handle = NULL;
2423 struct mpage_da_data mpd;
2424 struct inode *inode = mapping->host;
2425 int pages_written = 0;
2426 unsigned int max_pages;
2427 int range_cyclic, cycled = 1, io_done = 0;
2428 int needed_blocks, ret = 0;
2429 long desired_nr_to_write, nr_to_writebump = 0;
2430 loff_t range_start = wbc->range_start;
2431 struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
2432 pgoff_t done_index = 0;
2434 struct blk_plug plug;
2436 trace_ext4_da_writepages(inode, wbc);
2439 * No pages to write? This is mainly a kludge to avoid starting
2440 * a transaction for special inodes like journal inode on last iput()
2441 * because that could violate lock ordering on umount
2443 if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2447 * If the filesystem has aborted, it is read-only, so return
2448 * right away instead of dumping stack traces later on that
2449 * will obscure the real source of the problem. We test
2450 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2451 * the latter could be true if the filesystem is mounted
2452 * read-only, and in that case, ext4_da_writepages should
2453 * *never* be called, so if that ever happens, we would want
2456 if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED))
2459 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2462 range_cyclic = wbc->range_cyclic;
2463 if (wbc->range_cyclic) {
2464 index = mapping->writeback_index;
2467 wbc->range_start = index << PAGE_CACHE_SHIFT;
2468 wbc->range_end = LLONG_MAX;
2469 wbc->range_cyclic = 0;
2472 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2473 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2477 * This works around two forms of stupidity. The first is in
2478 * the writeback code, which caps the maximum number of pages
2479 * written to be 1024 pages. This is wrong on multiple
2480 * levels; different architectues have a different page size,
2481 * which changes the maximum amount of data which gets
2482 * written. Secondly, 4 megabytes is way too small. XFS
2483 * forces this value to be 16 megabytes by multiplying
2484 * nr_to_write parameter by four, and then relies on its
2485 * allocator to allocate larger extents to make them
2486 * contiguous. Unfortunately this brings us to the second
2487 * stupidity, which is that ext4's mballoc code only allocates
2488 * at most 2048 blocks. So we force contiguous writes up to
2489 * the number of dirty blocks in the inode, or
2490 * sbi->max_writeback_mb_bump whichever is smaller.
2492 max_pages = sbi->s_max_writeback_mb_bump << (20 - PAGE_CACHE_SHIFT);
2493 if (!range_cyclic && range_whole) {
2494 if (wbc->nr_to_write == LONG_MAX)
2495 desired_nr_to_write = wbc->nr_to_write;
2497 desired_nr_to_write = wbc->nr_to_write * 8;
2499 desired_nr_to_write = ext4_num_dirty_pages(inode, index,
2501 if (desired_nr_to_write > max_pages)
2502 desired_nr_to_write = max_pages;
2504 if (wbc->nr_to_write < desired_nr_to_write) {
2505 nr_to_writebump = desired_nr_to_write - wbc->nr_to_write;
2506 wbc->nr_to_write = desired_nr_to_write;
2510 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2511 tag_pages_for_writeback(mapping, index, end);
2513 blk_start_plug(&plug);
2514 while (!ret && wbc->nr_to_write > 0) {
2517 * we insert one extent at a time. So we need
2518 * credit needed for single extent allocation.
2519 * journalled mode is currently not supported
2522 BUG_ON(ext4_should_journal_data(inode));
2523 needed_blocks = ext4_da_writepages_trans_blocks(inode);
2525 /* start a new transaction*/
2526 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
2528 if (IS_ERR(handle)) {
2529 ret = PTR_ERR(handle);
2530 ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
2531 "%ld pages, ino %lu; err %d", __func__,
2532 wbc->nr_to_write, inode->i_ino, ret);
2533 blk_finish_plug(&plug);
2534 goto out_writepages;
2538 * Now call write_cache_pages_da() to find the next
2539 * contiguous region of logical blocks that need
2540 * blocks to be allocated by ext4 and submit them.
2542 ret = write_cache_pages_da(handle, mapping,
2543 wbc, &mpd, &done_index);
2545 * If we have a contiguous extent of pages and we
2546 * haven't done the I/O yet, map the blocks and submit
2549 if (!mpd.io_done && mpd.next_page != mpd.first_page) {
2550 mpage_da_map_and_submit(&mpd);
2551 ret = MPAGE_DA_EXTENT_TAIL;
2553 trace_ext4_da_write_pages(inode, &mpd);
2554 wbc->nr_to_write -= mpd.pages_written;
2556 ext4_journal_stop(handle);
2558 if ((mpd.retval == -ENOSPC) && sbi->s_journal) {
2559 /* commit the transaction which would
2560 * free blocks released in the transaction
2563 jbd2_journal_force_commit_nested(sbi->s_journal);
2565 } else if (ret == MPAGE_DA_EXTENT_TAIL) {
2567 * Got one extent now try with rest of the pages.
2568 * If mpd.retval is set -EIO, journal is aborted.
2569 * So we don't need to write any more.
2571 pages_written += mpd.pages_written;
2574 } else if (wbc->nr_to_write)
2576 * There is no more writeout needed
2577 * or we requested for a noblocking writeout
2578 * and we found the device congested
2582 blk_finish_plug(&plug);
2583 if (!io_done && !cycled) {
2586 wbc->range_start = index << PAGE_CACHE_SHIFT;
2587 wbc->range_end = mapping->writeback_index - 1;
2592 wbc->range_cyclic = range_cyclic;
2593 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2595 * set the writeback_index so that range_cyclic
2596 * mode will write it back later
2598 mapping->writeback_index = done_index;
2601 wbc->nr_to_write -= nr_to_writebump;
2602 wbc->range_start = range_start;
2603 trace_ext4_da_writepages_result(inode, wbc, ret, pages_written);
2607 static int ext4_nonda_switch(struct super_block *sb)
2609 s64 free_blocks, dirty_blocks;
2610 struct ext4_sb_info *sbi = EXT4_SB(sb);
2613 * switch to non delalloc mode if we are running low
2614 * on free block. The free block accounting via percpu
2615 * counters can get slightly wrong with percpu_counter_batch getting
2616 * accumulated on each CPU without updating global counters
2617 * Delalloc need an accurate free block accounting. So switch
2618 * to non delalloc when we are near to error range.
2620 free_blocks = EXT4_C2B(sbi,
2621 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
2622 dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyclusters_counter);
2624 * Start pushing delalloc when 1/2 of free blocks are dirty.
2626 if (dirty_blocks && (free_blocks < 2 * dirty_blocks))
2627 try_to_writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE);
2629 if (2 * free_blocks < 3 * dirty_blocks ||
2630 free_blocks < (dirty_blocks + EXT4_FREECLUSTERS_WATERMARK)) {
2632 * free block count is less than 150% of dirty blocks
2633 * or free blocks is less than watermark
2640 static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
2641 loff_t pos, unsigned len, unsigned flags,
2642 struct page **pagep, void **fsdata)
2644 int ret, retries = 0;
2647 struct inode *inode = mapping->host;
2650 index = pos >> PAGE_CACHE_SHIFT;
2652 if (ext4_nonda_switch(inode->i_sb)) {
2653 *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
2654 return ext4_write_begin(file, mapping, pos,
2655 len, flags, pagep, fsdata);
2657 *fsdata = (void *)0;
2658 trace_ext4_da_write_begin(inode, pos, len, flags);
2660 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2661 ret = ext4_da_write_inline_data_begin(mapping, inode,
2671 * grab_cache_page_write_begin() can take a long time if the
2672 * system is thrashing due to memory pressure, or if the page
2673 * is being written back. So grab it first before we start
2674 * the transaction handle. This also allows us to allocate
2675 * the page (if needed) without using GFP_NOFS.
2678 page = grab_cache_page_write_begin(mapping, index, flags);
2684 * With delayed allocation, we don't log the i_disksize update
2685 * if there is delayed block allocation. But we still need
2686 * to journalling the i_disksize update if writes to the end
2687 * of file which has an already mapped buffer.
2690 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, 1);
2691 if (IS_ERR(handle)) {
2692 page_cache_release(page);
2693 return PTR_ERR(handle);
2697 if (page->mapping != mapping) {
2698 /* The page got truncated from under us */
2700 page_cache_release(page);
2701 ext4_journal_stop(handle);
2704 /* In case writeback began while the page was unlocked */
2705 wait_on_page_writeback(page);
2707 ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep);
2710 ext4_journal_stop(handle);
2712 * block_write_begin may have instantiated a few blocks
2713 * outside i_size. Trim these off again. Don't need
2714 * i_size_read because we hold i_mutex.
2716 if (pos + len > inode->i_size)
2717 ext4_truncate_failed_write(inode);
2719 if (ret == -ENOSPC &&
2720 ext4_should_retry_alloc(inode->i_sb, &retries))
2723 page_cache_release(page);
2732 * Check if we should update i_disksize
2733 * when write to the end of file but not require block allocation
2735 static int ext4_da_should_update_i_disksize(struct page *page,
2736 unsigned long offset)
2738 struct buffer_head *bh;
2739 struct inode *inode = page->mapping->host;
2743 bh = page_buffers(page);
2744 idx = offset >> inode->i_blkbits;
2746 for (i = 0; i < idx; i++)
2747 bh = bh->b_this_page;
2749 if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
2754 static int ext4_da_write_end(struct file *file,
2755 struct address_space *mapping,
2756 loff_t pos, unsigned len, unsigned copied,
2757 struct page *page, void *fsdata)
2759 struct inode *inode = mapping->host;
2761 handle_t *handle = ext4_journal_current_handle();
2763 unsigned long start, end;
2764 int write_mode = (int)(unsigned long)fsdata;
2766 if (write_mode == FALL_BACK_TO_NONDELALLOC)
2767 return ext4_write_end(file, mapping, pos,
2768 len, copied, page, fsdata);
2770 trace_ext4_da_write_end(inode, pos, len, copied);
2771 start = pos & (PAGE_CACHE_SIZE - 1);
2772 end = start + copied - 1;
2775 * generic_write_end() will run mark_inode_dirty() if i_size
2776 * changes. So let's piggyback the i_disksize mark_inode_dirty
2779 new_i_size = pos + copied;
2780 if (copied && new_i_size > EXT4_I(inode)->i_disksize) {
2781 if (ext4_has_inline_data(inode) ||
2782 ext4_da_should_update_i_disksize(page, end)) {
2783 down_write(&EXT4_I(inode)->i_data_sem);
2784 if (new_i_size > EXT4_I(inode)->i_disksize)
2785 EXT4_I(inode)->i_disksize = new_i_size;
2786 up_write(&EXT4_I(inode)->i_data_sem);
2787 /* We need to mark inode dirty even if
2788 * new_i_size is less that inode->i_size
2789 * bu greater than i_disksize.(hint delalloc)
2791 ext4_mark_inode_dirty(handle, inode);
2795 if (write_mode != CONVERT_INLINE_DATA &&
2796 ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) &&
2797 ext4_has_inline_data(inode))
2798 ret2 = ext4_da_write_inline_data_end(inode, pos, len, copied,
2801 ret2 = generic_write_end(file, mapping, pos, len, copied,
2807 ret2 = ext4_journal_stop(handle);
2811 return ret ? ret : copied;
2814 static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
2817 * Drop reserved blocks
2819 BUG_ON(!PageLocked(page));
2820 if (!page_has_buffers(page))
2823 ext4_da_page_release_reservation(page, offset);
2826 ext4_invalidatepage(page, offset);
2832 * Force all delayed allocation blocks to be allocated for a given inode.
2834 int ext4_alloc_da_blocks(struct inode *inode)
2836 trace_ext4_alloc_da_blocks(inode);
2838 if (!EXT4_I(inode)->i_reserved_data_blocks &&
2839 !EXT4_I(inode)->i_reserved_meta_blocks)
2843 * We do something simple for now. The filemap_flush() will
2844 * also start triggering a write of the data blocks, which is
2845 * not strictly speaking necessary (and for users of
2846 * laptop_mode, not even desirable). However, to do otherwise
2847 * would require replicating code paths in:
2849 * ext4_da_writepages() ->
2850 * write_cache_pages() ---> (via passed in callback function)
2851 * __mpage_da_writepage() -->
2852 * mpage_add_bh_to_extent()
2853 * mpage_da_map_blocks()
2855 * The problem is that write_cache_pages(), located in
2856 * mm/page-writeback.c, marks pages clean in preparation for
2857 * doing I/O, which is not desirable if we're not planning on
2860 * We could call write_cache_pages(), and then redirty all of
2861 * the pages by calling redirty_page_for_writepage() but that
2862 * would be ugly in the extreme. So instead we would need to
2863 * replicate parts of the code in the above functions,
2864 * simplifying them because we wouldn't actually intend to
2865 * write out the pages, but rather only collect contiguous
2866 * logical block extents, call the multi-block allocator, and
2867 * then update the buffer heads with the block allocations.
2869 * For now, though, we'll cheat by calling filemap_flush(),
2870 * which will map the blocks, and start the I/O, but not
2871 * actually wait for the I/O to complete.
2873 return filemap_flush(inode->i_mapping);
2877 * bmap() is special. It gets used by applications such as lilo and by
2878 * the swapper to find the on-disk block of a specific piece of data.
2880 * Naturally, this is dangerous if the block concerned is still in the
2881 * journal. If somebody makes a swapfile on an ext4 data-journaling
2882 * filesystem and enables swap, then they may get a nasty shock when the
2883 * data getting swapped to that swapfile suddenly gets overwritten by
2884 * the original zero's written out previously to the journal and
2885 * awaiting writeback in the kernel's buffer cache.
2887 * So, if we see any bmap calls here on a modified, data-journaled file,
2888 * take extra steps to flush any blocks which might be in the cache.
2890 static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
2892 struct inode *inode = mapping->host;
2897 * We can get here for an inline file via the FIBMAP ioctl
2899 if (ext4_has_inline_data(inode))
2902 if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
2903 test_opt(inode->i_sb, DELALLOC)) {
2905 * With delalloc we want to sync the file
2906 * so that we can make sure we allocate
2909 filemap_write_and_wait(mapping);
2912 if (EXT4_JOURNAL(inode) &&
2913 ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {
2915 * This is a REALLY heavyweight approach, but the use of
2916 * bmap on dirty files is expected to be extremely rare:
2917 * only if we run lilo or swapon on a freshly made file
2918 * do we expect this to happen.
2920 * (bmap requires CAP_SYS_RAWIO so this does not
2921 * represent an unprivileged user DOS attack --- we'd be
2922 * in trouble if mortal users could trigger this path at
2925 * NB. EXT4_STATE_JDATA is not set on files other than
2926 * regular files. If somebody wants to bmap a directory
2927 * or symlink and gets confused because the buffer
2928 * hasn't yet been flushed to disk, they deserve
2929 * everything they get.
2932 ext4_clear_inode_state(inode, EXT4_STATE_JDATA);
2933 journal = EXT4_JOURNAL(inode);
2934 jbd2_journal_lock_updates(journal);
2935 err = jbd2_journal_flush(journal);
2936 jbd2_journal_unlock_updates(journal);
2942 return generic_block_bmap(mapping, block, ext4_get_block);
2945 static int ext4_readpage(struct file *file, struct page *page)
2948 struct inode *inode = page->mapping->host;
2950 trace_ext4_readpage(page);
2952 if (ext4_has_inline_data(inode))
2953 ret = ext4_readpage_inline(inode, page);
2956 return mpage_readpage(page, ext4_get_block);
2962 ext4_readpages(struct file *file, struct address_space *mapping,
2963 struct list_head *pages, unsigned nr_pages)
2965 struct inode *inode = mapping->host;
2967 /* If the file has inline data, no need to do readpages. */
2968 if (ext4_has_inline_data(inode))
2971 return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
2974 static void ext4_invalidatepage(struct page *page, unsigned long offset)
2976 trace_ext4_invalidatepage(page, offset);
2978 /* No journalling happens on data buffers when this function is used */
2979 WARN_ON(page_has_buffers(page) && buffer_jbd(page_buffers(page)));
2981 block_invalidatepage(page, offset);
2984 static int __ext4_journalled_invalidatepage(struct page *page,
2985 unsigned long offset)
2987 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
2989 trace_ext4_journalled_invalidatepage(page, offset);
2992 * If it's a full truncate we just forget about the pending dirtying
2995 ClearPageChecked(page);
2997 return jbd2_journal_invalidatepage(journal, page, offset);
3000 /* Wrapper for aops... */
3001 static void ext4_journalled_invalidatepage(struct page *page,
3002 unsigned long offset)
3004 WARN_ON(__ext4_journalled_invalidatepage(page, offset) < 0);
3007 static int ext4_releasepage(struct page *page, gfp_t wait)
3009 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
3011 trace_ext4_releasepage(page);
3013 /* Page has dirty journalled data -> cannot release */
3014 if (PageChecked(page))
3017 return jbd2_journal_try_to_free_buffers(journal, page, wait);
3019 return try_to_free_buffers(page);
3023 * ext4_get_block used when preparing for a DIO write or buffer write.
3024 * We allocate an uinitialized extent if blocks haven't been allocated.
3025 * The extent will be converted to initialized after the IO is complete.
3027 int ext4_get_block_write(struct inode *inode, sector_t iblock,
3028 struct buffer_head *bh_result, int create)
3030 ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n",
3031 inode->i_ino, create);
3032 return _ext4_get_block(inode, iblock, bh_result,
3033 EXT4_GET_BLOCKS_IO_CREATE_EXT);
3036 static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock,
3037 struct buffer_head *bh_result, int create)
3039 ext4_debug("ext4_get_block_write_nolock: inode %lu, create flag %d\n",
3040 inode->i_ino, create);
3041 return _ext4_get_block(inode, iblock, bh_result,
3042 EXT4_GET_BLOCKS_NO_LOCK);
3045 static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
3046 ssize_t size, void *private, int ret,
3049 struct inode *inode = file_inode(iocb->ki_filp);
3050 ext4_io_end_t *io_end = iocb->private;
3052 /* if not async direct IO or dio with 0 bytes write, just return */
3053 if (!io_end || !size)
3056 ext_debug("ext4_end_io_dio(): io_end 0x%p "
3057 "for inode %lu, iocb 0x%p, offset %llu, size %zd\n",
3058 iocb->private, io_end->inode->i_ino, iocb, offset,
3061 iocb->private = NULL;
3063 /* if not aio dio with unwritten extents, just free io and return */
3064 if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
3065 ext4_free_io_end(io_end);
3067 inode_dio_done(inode);
3069 aio_complete(iocb, ret, 0);
3073 io_end->offset = offset;
3074 io_end->size = size;
3076 io_end->iocb = iocb;
3077 io_end->result = ret;
3080 ext4_add_complete_io(io_end);
3084 * For ext4 extent files, ext4 will do direct-io write to holes,
3085 * preallocated extents, and those write extend the file, no need to
3086 * fall back to buffered IO.
3088 * For holes, we fallocate those blocks, mark them as uninitialized
3089 * If those blocks were preallocated, we mark sure they are split, but
3090 * still keep the range to write as uninitialized.
3092 * The unwritten extents will be converted to written when DIO is completed.
3093 * For async direct IO, since the IO may still pending when return, we
3094 * set up an end_io call back function, which will do the conversion
3095 * when async direct IO completed.
3097 * If the O_DIRECT write will extend the file then add this inode to the
3098 * orphan list. So recovery will truncate it back to the original size
3099 * if the machine crashes during the write.
3102 static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
3103 const struct iovec *iov, loff_t offset,
3104 unsigned long nr_segs)
3106 struct file *file = iocb->ki_filp;
3107 struct inode *inode = file->f_mapping->host;
3109 size_t count = iov_length(iov, nr_segs);
3111 get_block_t *get_block_func = NULL;
3113 loff_t final_size = offset + count;
3115 /* Use the old path for reads and writes beyond i_size. */
3116 if (rw != WRITE || final_size > inode->i_size)
3117 return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3119 BUG_ON(iocb->private == NULL);
3121 /* If we do a overwrite dio, i_mutex locking can be released */
3122 overwrite = *((int *)iocb->private);
3125 atomic_inc(&inode->i_dio_count);
3126 down_read(&EXT4_I(inode)->i_data_sem);
3127 mutex_unlock(&inode->i_mutex);
3131 * We could direct write to holes and fallocate.
3133 * Allocated blocks to fill the hole are marked as
3134 * uninitialized to prevent parallel buffered read to expose
3135 * the stale data before DIO complete the data IO.
3137 * As to previously fallocated extents, ext4 get_block will
3138 * just simply mark the buffer mapped but still keep the
3139 * extents uninitialized.
3141 * For non AIO case, we will convert those unwritten extents
3142 * to written after return back from blockdev_direct_IO.
3144 * For async DIO, the conversion needs to be deferred when the
3145 * IO is completed. The ext4 end_io callback function will be
3146 * called to take care of the conversion work. Here for async
3147 * case, we allocate an io_end structure to hook to the iocb.
3149 iocb->private = NULL;
3150 ext4_inode_aio_set(inode, NULL);
3151 if (!is_sync_kiocb(iocb)) {
3152 ext4_io_end_t *io_end = ext4_init_io_end(inode, GFP_NOFS);
3157 io_end->flag |= EXT4_IO_END_DIRECT;
3158 iocb->private = io_end;
3160 * we save the io structure for current async direct
3161 * IO, so that later ext4_map_blocks() could flag the
3162 * io structure whether there is a unwritten extents
3163 * needs to be converted when IO is completed.
3165 ext4_inode_aio_set(inode, io_end);
3169 get_block_func = ext4_get_block_write_nolock;
3171 get_block_func = ext4_get_block_write;
3172 dio_flags = DIO_LOCKING;
3174 ret = __blockdev_direct_IO(rw, iocb, inode,
3175 inode->i_sb->s_bdev, iov,
3183 ext4_inode_aio_set(inode, NULL);
3185 * The io_end structure takes a reference to the inode, that
3186 * structure needs to be destroyed and the reference to the
3187 * inode need to be dropped, when IO is complete, even with 0
3188 * byte write, or failed.
3190 * In the successful AIO DIO case, the io_end structure will
3191 * be destroyed and the reference to the inode will be dropped
3192 * after the end_io call back function is called.
3194 * In the case there is 0 byte write, or error case, since VFS
3195 * direct IO won't invoke the end_io call back function, we
3196 * need to free the end_io structure here.
3198 if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
3199 ext4_free_io_end(iocb->private);
3200 iocb->private = NULL;
3201 } else if (ret > 0 && !overwrite && ext4_test_inode_state(inode,
3202 EXT4_STATE_DIO_UNWRITTEN)) {
3205 * for non AIO case, since the IO is already
3206 * completed, we could do the conversion right here
3208 err = ext4_convert_unwritten_extents(inode,
3212 ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3216 /* take i_mutex locking again if we do a ovewrite dio */
3218 inode_dio_done(inode);
3219 up_read(&EXT4_I(inode)->i_data_sem);
3220 mutex_lock(&inode->i_mutex);
3226 static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
3227 const struct iovec *iov, loff_t offset,
3228 unsigned long nr_segs)
3230 struct file *file = iocb->ki_filp;
3231 struct inode *inode = file->f_mapping->host;
3235 * If we are doing data journalling we don't support O_DIRECT
3237 if (ext4_should_journal_data(inode))
3240 /* Let buffer I/O handle the inline data case. */
3241 if (ext4_has_inline_data(inode))
3244 trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);
3245 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3246 ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
3248 ret = ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3249 trace_ext4_direct_IO_exit(inode, offset,
3250 iov_length(iov, nr_segs), rw, ret);
3255 * Pages can be marked dirty completely asynchronously from ext4's journalling
3256 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3257 * much here because ->set_page_dirty is called under VFS locks. The page is
3258 * not necessarily locked.
3260 * We cannot just dirty the page and leave attached buffers clean, because the
3261 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3262 * or jbddirty because all the journalling code will explode.
3264 * So what we do is to mark the page "pending dirty" and next time writepage
3265 * is called, propagate that into the buffers appropriately.
3267 static int ext4_journalled_set_page_dirty(struct page *page)
3269 SetPageChecked(page);
3270 return __set_page_dirty_nobuffers(page);
3273 static const struct address_space_operations ext4_aops = {
3274 .readpage = ext4_readpage,
3275 .readpages = ext4_readpages,
3276 .writepage = ext4_writepage,
3277 .write_begin = ext4_write_begin,
3278 .write_end = ext4_write_end,
3280 .invalidatepage = ext4_invalidatepage,
3281 .releasepage = ext4_releasepage,
3282 .direct_IO = ext4_direct_IO,
3283 .migratepage = buffer_migrate_page,
3284 .is_partially_uptodate = block_is_partially_uptodate,
3285 .error_remove_page = generic_error_remove_page,
3288 static const struct address_space_operations ext4_journalled_aops = {
3289 .readpage = ext4_readpage,
3290 .readpages = ext4_readpages,
3291 .writepage = ext4_writepage,
3292 .write_begin = ext4_write_begin,
3293 .write_end = ext4_journalled_write_end,
3294 .set_page_dirty = ext4_journalled_set_page_dirty,
3296 .invalidatepage = ext4_journalled_invalidatepage,
3297 .releasepage = ext4_releasepage,
3298 .direct_IO = ext4_direct_IO,
3299 .is_partially_uptodate = block_is_partially_uptodate,
3300 .error_remove_page = generic_error_remove_page,
3303 static const struct address_space_operations ext4_da_aops = {
3304 .readpage = ext4_readpage,
3305 .readpages = ext4_readpages,
3306 .writepage = ext4_writepage,
3307 .writepages = ext4_da_writepages,
3308 .write_begin = ext4_da_write_begin,
3309 .write_end = ext4_da_write_end,
3311 .invalidatepage = ext4_da_invalidatepage,
3312 .releasepage = ext4_releasepage,
3313 .direct_IO = ext4_direct_IO,
3314 .migratepage = buffer_migrate_page,
3315 .is_partially_uptodate = block_is_partially_uptodate,
3316 .error_remove_page = generic_error_remove_page,
3319 void ext4_set_aops(struct inode *inode)
3321 switch (ext4_inode_journal_mode(inode)) {
3322 case EXT4_INODE_ORDERED_DATA_MODE:
3323 ext4_set_inode_state(inode, EXT4_STATE_ORDERED_MODE);
3325 case EXT4_INODE_WRITEBACK_DATA_MODE:
3326 ext4_clear_inode_state(inode, EXT4_STATE_ORDERED_MODE);
3328 case EXT4_INODE_JOURNAL_DATA_MODE:
3329 inode->i_mapping->a_ops = &ext4_journalled_aops;
3334 if (test_opt(inode->i_sb, DELALLOC))
3335 inode->i_mapping->a_ops = &ext4_da_aops;
3337 inode->i_mapping->a_ops = &ext4_aops;
3342 * ext4_discard_partial_page_buffers()
3343 * Wrapper function for ext4_discard_partial_page_buffers_no_lock.
3344 * This function finds and locks the page containing the offset
3345 * "from" and passes it to ext4_discard_partial_page_buffers_no_lock.
3346 * Calling functions that already have the page locked should call
3347 * ext4_discard_partial_page_buffers_no_lock directly.
3349 int ext4_discard_partial_page_buffers(handle_t *handle,
3350 struct address_space *mapping, loff_t from,
3351 loff_t length, int flags)
3353 struct inode *inode = mapping->host;
3357 page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT,
3358 mapping_gfp_mask(mapping) & ~__GFP_FS);
3362 err = ext4_discard_partial_page_buffers_no_lock(handle, inode, page,
3363 from, length, flags);
3366 page_cache_release(page);
3371 * ext4_discard_partial_page_buffers_no_lock()
3372 * Zeros a page range of length 'length' starting from offset 'from'.
3373 * Buffer heads that correspond to the block aligned regions of the
3374 * zeroed range will be unmapped. Unblock aligned regions
3375 * will have the corresponding buffer head mapped if needed so that
3376 * that region of the page can be updated with the partial zero out.
3378 * This function assumes that the page has already been locked. The
3379 * The range to be discarded must be contained with in the given page.
3380 * If the specified range exceeds the end of the page it will be shortened
3381 * to the end of the page that corresponds to 'from'. This function is
3382 * appropriate for updating a page and it buffer heads to be unmapped and
3383 * zeroed for blocks that have been either released, or are going to be
3386 * handle: The journal handle
3387 * inode: The files inode
3388 * page: A locked page that contains the offset "from"
3389 * from: The starting byte offset (from the beginning of the file)
3390 * to begin discarding
3391 * len: The length of bytes to discard
3392 * flags: Optional flags that may be used:
3394 * EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED
3395 * Only zero the regions of the page whose buffer heads
3396 * have already been unmapped. This flag is appropriate
3397 * for updating the contents of a page whose blocks may
3398 * have already been released, and we only want to zero
3399 * out the regions that correspond to those released blocks.
3401 * Returns zero on success or negative on failure.
3403 static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
3404 struct inode *inode, struct page *page, loff_t from,
3405 loff_t length, int flags)
3407 ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
3408 unsigned int offset = from & (PAGE_CACHE_SIZE-1);
3409 unsigned int blocksize, max, pos;
3411 struct buffer_head *bh;
3414 blocksize = inode->i_sb->s_blocksize;
3415 max = PAGE_CACHE_SIZE - offset;
3417 if (index != page->index)
3421 * correct length if it does not fall between
3422 * 'from' and the end of the page
3424 if (length > max || length < 0)
3427 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
3429 if (!page_has_buffers(page))
3430 create_empty_buffers(page, blocksize, 0);
3432 /* Find the buffer that contains "offset" */
3433 bh = page_buffers(page);
3435 while (offset >= pos) {
3436 bh = bh->b_this_page;
3442 while (pos < offset + length) {
3443 unsigned int end_of_block, range_to_discard;
3447 /* The length of space left to zero and unmap */
3448 range_to_discard = offset + length - pos;
3450 /* The length of space until the end of the block */
3451 end_of_block = blocksize - (pos & (blocksize-1));
3454 * Do not unmap or zero past end of block
3455 * for this buffer head
3457 if (range_to_discard > end_of_block)
3458 range_to_discard = end_of_block;
3462 * Skip this buffer head if we are only zeroing unampped
3463 * regions of the page
3465 if (flags & EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED &&
3469 /* If the range is block aligned, unmap */
3470 if (range_to_discard == blocksize) {
3471 clear_buffer_dirty(bh);
3473 clear_buffer_mapped(bh);
3474 clear_buffer_req(bh);
3475 clear_buffer_new(bh);
3476 clear_buffer_delay(bh);
3477 clear_buffer_unwritten(bh);
3478 clear_buffer_uptodate(bh);
3479 zero_user(page, pos, range_to_discard);
3480 BUFFER_TRACE(bh, "Buffer discarded");
3485 * If this block is not completely contained in the range
3486 * to be discarded, then it is not going to be released. Because
3487 * we need to keep this block, we need to make sure this part
3488 * of the page is uptodate before we modify it by writeing
3489 * partial zeros on it.
3491 if (!buffer_mapped(bh)) {
3493 * Buffer head must be mapped before we can read
3496 BUFFER_TRACE(bh, "unmapped");
3497 ext4_get_block(inode, iblock, bh, 0);
3498 /* unmapped? It's a hole - nothing to do */
3499 if (!buffer_mapped(bh)) {
3500 BUFFER_TRACE(bh, "still unmapped");
3505 /* Ok, it's mapped. Make sure it's up-to-date */
3506 if (PageUptodate(page))
3507 set_buffer_uptodate(bh);
3509 if (!buffer_uptodate(bh)) {
3511 ll_rw_block(READ, 1, &bh);
3513 /* Uhhuh. Read error. Complain and punt.*/
3514 if (!buffer_uptodate(bh))
3518 if (ext4_should_journal_data(inode)) {
3519 BUFFER_TRACE(bh, "get write access");
3520 err = ext4_journal_get_write_access(handle, bh);
3525 zero_user(page, pos, range_to_discard);
3528 if (ext4_should_journal_data(inode)) {
3529 err = ext4_handle_dirty_metadata(handle, inode, bh);
3531 mark_buffer_dirty(bh);
3533 BUFFER_TRACE(bh, "Partial buffer zeroed");
3535 bh = bh->b_this_page;
3537 pos += range_to_discard;
3543 int ext4_can_truncate(struct inode *inode)
3545 if (S_ISREG(inode->i_mode))
3547 if (S_ISDIR(inode->i_mode))
3549 if (S_ISLNK(inode->i_mode))
3550 return !ext4_inode_is_fast_symlink(inode);
3555 * ext4_punch_hole: punches a hole in a file by releaseing the blocks
3556 * associated with the given offset and length
3558 * @inode: File inode
3559 * @offset: The offset where the hole will begin
3560 * @len: The length of the hole
3562 * Returns: 0 on success or negative on failure
3565 int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
3567 struct inode *inode = file_inode(file);
3568 struct super_block *sb = inode->i_sb;
3569 ext4_lblk_t first_block, stop_block;
3570 struct address_space *mapping = inode->i_mapping;
3571 loff_t first_page, last_page, page_len;
3572 loff_t first_page_offset, last_page_offset;
3574 unsigned int credits;
3577 if (!S_ISREG(inode->i_mode))
3580 if (EXT4_SB(sb)->s_cluster_ratio > 1) {
3581 /* TODO: Add support for bigalloc file systems */
3585 trace_ext4_punch_hole(inode, offset, length);
3588 * Write out all dirty pages to avoid race conditions
3589 * Then release them.
3591 if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
3592 ret = filemap_write_and_wait_range(mapping, offset,
3593 offset + length - 1);
3598 mutex_lock(&inode->i_mutex);
3599 /* It's not possible punch hole on append only file */
3600 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) {
3604 if (IS_SWAPFILE(inode)) {
3609 /* No need to punch hole beyond i_size */
3610 if (offset >= inode->i_size)
3614 * If the hole extends beyond i_size, set the hole
3615 * to end after the page that contains i_size
3617 if (offset + length > inode->i_size) {
3618 length = inode->i_size +
3619 PAGE_CACHE_SIZE - (inode->i_size & (PAGE_CACHE_SIZE - 1)) -
3623 first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
3624 last_page = (offset + length) >> PAGE_CACHE_SHIFT;
3626 first_page_offset = first_page << PAGE_CACHE_SHIFT;
3627 last_page_offset = last_page << PAGE_CACHE_SHIFT;
3629 /* Now release the pages */
3630 if (last_page_offset > first_page_offset) {
3631 truncate_pagecache_range(inode, first_page_offset,
3632 last_page_offset - 1);
3635 /* Wait all existing dio workers, newcomers will block on i_mutex */
3636 ext4_inode_block_unlocked_dio(inode);
3637 ret = ext4_flush_unwritten_io(inode);
3640 inode_dio_wait(inode);
3642 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3643 credits = ext4_writepage_trans_blocks(inode);
3645 credits = ext4_blocks_for_truncate(inode);
3646 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
3647 if (IS_ERR(handle)) {
3648 ret = PTR_ERR(handle);
3649 ext4_std_error(sb, ret);
3654 * Now we need to zero out the non-page-aligned data in the
3655 * pages at the start and tail of the hole, and unmap the
3656 * buffer heads for the block aligned regions of the page that
3657 * were completely zeroed.
3659 if (first_page > last_page) {
3661 * If the file space being truncated is contained
3662 * within a page just zero out and unmap the middle of
3665 ret = ext4_discard_partial_page_buffers(handle,
3666 mapping, offset, length, 0);
3672 * zero out and unmap the partial page that contains
3673 * the start of the hole
3675 page_len = first_page_offset - offset;
3677 ret = ext4_discard_partial_page_buffers(handle, mapping,
3678 offset, page_len, 0);
3684 * zero out and unmap the partial page that contains
3685 * the end of the hole
3687 page_len = offset + length - last_page_offset;
3689 ret = ext4_discard_partial_page_buffers(handle, mapping,
3690 last_page_offset, page_len, 0);
3697 * If i_size is contained in the last page, we need to
3698 * unmap and zero the partial page after i_size
3700 if (inode->i_size >> PAGE_CACHE_SHIFT == last_page &&
3701 inode->i_size % PAGE_CACHE_SIZE != 0) {
3702 page_len = PAGE_CACHE_SIZE -
3703 (inode->i_size & (PAGE_CACHE_SIZE - 1));
3706 ret = ext4_discard_partial_page_buffers(handle,
3707 mapping, inode->i_size, page_len, 0);
3714 first_block = (offset + sb->s_blocksize - 1) >>
3715 EXT4_BLOCK_SIZE_BITS(sb);
3716 stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
3718 /* If there are no blocks to remove, return now */
3719 if (first_block >= stop_block)
3722 down_write(&EXT4_I(inode)->i_data_sem);
3723 ext4_discard_preallocations(inode);
3725 ret = ext4_es_remove_extent(inode, first_block,
3726 stop_block - first_block);
3728 up_write(&EXT4_I(inode)->i_data_sem);
3732 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3733 ret = ext4_ext_remove_space(inode, first_block,
3736 ret = ext4_free_hole_blocks(handle, inode, first_block,
3739 ext4_discard_preallocations(inode);
3740 up_write(&EXT4_I(inode)->i_data_sem);
3742 ext4_handle_sync(handle);
3743 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
3744 ext4_mark_inode_dirty(handle, inode);
3746 ext4_journal_stop(handle);
3748 ext4_inode_resume_unlocked_dio(inode);
3750 mutex_unlock(&inode->i_mutex);
3757 * We block out ext4_get_block() block instantiations across the entire
3758 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
3759 * simultaneously on behalf of the same inode.
3761 * As we work through the truncate and commit bits of it to the journal there
3762 * is one core, guiding principle: the file's tree must always be consistent on
3763 * disk. We must be able to restart the truncate after a crash.
3765 * The file's tree may be transiently inconsistent in memory (although it
3766 * probably isn't), but whenever we close off and commit a journal transaction,
3767 * the contents of (the filesystem + the journal) must be consistent and
3768 * restartable. It's pretty simple, really: bottom up, right to left (although
3769 * left-to-right works OK too).
3771 * Note that at recovery time, journal replay occurs *before* the restart of
3772 * truncate against the orphan inode list.
3774 * The committed inode has the new, desired i_size (which is the same as
3775 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
3776 * that this inode's truncate did not complete and it will again call
3777 * ext4_truncate() to have another go. So there will be instantiated blocks
3778 * to the right of the truncation point in a crashed ext4 filesystem. But
3779 * that's fine - as long as they are linked from the inode, the post-crash
3780 * ext4_truncate() run will find them and release them.
3782 void ext4_truncate(struct inode *inode)
3784 struct ext4_inode_info *ei = EXT4_I(inode);
3785 unsigned int credits;
3787 struct address_space *mapping = inode->i_mapping;
3791 * There is a possibility that we're either freeing the inode
3792 * or it completely new indode. In those cases we might not
3793 * have i_mutex locked because it's not necessary.
3795 if (!(inode->i_state & (I_NEW|I_FREEING)))
3796 WARN_ON(!mutex_is_locked(&inode->i_mutex));
3797 trace_ext4_truncate_enter(inode);
3799 if (!ext4_can_truncate(inode))
3802 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3804 if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
3805 ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
3807 if (ext4_has_inline_data(inode)) {
3810 ext4_inline_data_truncate(inode, &has_inline);
3816 * finish any pending end_io work so we won't run the risk of
3817 * converting any truncated blocks to initialized later
3819 ext4_flush_unwritten_io(inode);
3821 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3822 credits = ext4_writepage_trans_blocks(inode);
3824 credits = ext4_blocks_for_truncate(inode);
3826 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
3827 if (IS_ERR(handle)) {
3828 ext4_std_error(inode->i_sb, PTR_ERR(handle));
3832 if (inode->i_size % PAGE_CACHE_SIZE != 0) {
3833 page_len = PAGE_CACHE_SIZE -
3834 (inode->i_size & (PAGE_CACHE_SIZE - 1));
3836 if (ext4_discard_partial_page_buffers(handle,
3837 mapping, inode->i_size, page_len, 0))
3842 * We add the inode to the orphan list, so that if this
3843 * truncate spans multiple transactions, and we crash, we will
3844 * resume the truncate when the filesystem recovers. It also
3845 * marks the inode dirty, to catch the new size.
3847 * Implication: the file must always be in a sane, consistent
3848 * truncatable state while each transaction commits.
3850 if (ext4_orphan_add(handle, inode))
3853 down_write(&EXT4_I(inode)->i_data_sem);
3855 ext4_discard_preallocations(inode);
3857 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3858 ext4_ext_truncate(handle, inode);
3860 ext4_ind_truncate(handle, inode);
3862 up_write(&ei->i_data_sem);
3865 ext4_handle_sync(handle);
3869 * If this was a simple ftruncate() and the file will remain alive,
3870 * then we need to clear up the orphan record which we created above.
3871 * However, if this was a real unlink then we were called by
3872 * ext4_delete_inode(), and we allow that function to clean up the
3873 * orphan info for us.
3876 ext4_orphan_del(handle, inode);
3878 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
3879 ext4_mark_inode_dirty(handle, inode);
3880 ext4_journal_stop(handle);
3882 trace_ext4_truncate_exit(inode);
3886 * ext4_get_inode_loc returns with an extra refcount against the inode's
3887 * underlying buffer_head on success. If 'in_mem' is true, we have all
3888 * data in memory that is needed to recreate the on-disk version of this
3891 static int __ext4_get_inode_loc(struct inode *inode,
3892 struct ext4_iloc *iloc, int in_mem)
3894 struct ext4_group_desc *gdp;
3895 struct buffer_head *bh;
3896 struct super_block *sb = inode->i_sb;
3898 int inodes_per_block, inode_offset;
3901 if (!ext4_valid_inum(sb, inode->i_ino))
3904 iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
3905 gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
3910 * Figure out the offset within the block group inode table
3912 inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
3913 inode_offset = ((inode->i_ino - 1) %
3914 EXT4_INODES_PER_GROUP(sb));
3915 block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
3916 iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
3918 bh = sb_getblk(sb, block);
3921 if (!buffer_uptodate(bh)) {
3925 * If the buffer has the write error flag, we have failed
3926 * to write out another inode in the same block. In this
3927 * case, we don't have to read the block because we may
3928 * read the old inode data successfully.
3930 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
3931 set_buffer_uptodate(bh);
3933 if (buffer_uptodate(bh)) {
3934 /* someone brought it uptodate while we waited */
3940 * If we have all information of the inode in memory and this
3941 * is the only valid inode in the block, we need not read the
3945 struct buffer_head *bitmap_bh;
3948 start = inode_offset & ~(inodes_per_block - 1);
3950 /* Is the inode bitmap in cache? */
3951 bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
3952 if (unlikely(!bitmap_bh))
3956 * If the inode bitmap isn't in cache then the
3957 * optimisation may end up performing two reads instead
3958 * of one, so skip it.
3960 if (!buffer_uptodate(bitmap_bh)) {
3964 for (i = start; i < start + inodes_per_block; i++) {
3965 if (i == inode_offset)
3967 if (ext4_test_bit(i, bitmap_bh->b_data))
3971 if (i == start + inodes_per_block) {
3972 /* all other inodes are free, so skip I/O */
3973 memset(bh->b_data, 0, bh->b_size);
3974 set_buffer_uptodate(bh);
3982 * If we need to do any I/O, try to pre-readahead extra
3983 * blocks from the inode table.
3985 if (EXT4_SB(sb)->s_inode_readahead_blks) {
3986 ext4_fsblk_t b, end, table;
3989 table = ext4_inode_table(sb, gdp);
3990 /* s_inode_readahead_blks is always a power of 2 */
3991 b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1);
3994 end = b + EXT4_SB(sb)->s_inode_readahead_blks;
3995 num = EXT4_INODES_PER_GROUP(sb);
3996 if (ext4_has_group_desc_csum(sb))
3997 num -= ext4_itable_unused_count(sb, gdp);
3998 table += num / inodes_per_block;
4002 sb_breadahead(sb, b++);
4006 * There are other valid inodes in the buffer, this inode
4007 * has in-inode xattrs, or we don't have this inode in memory.
4008 * Read the block from disk.
4010 trace_ext4_load_inode(inode);
4012 bh->b_end_io = end_buffer_read_sync;
4013 submit_bh(READ | REQ_META | REQ_PRIO, bh);
4015 if (!buffer_uptodate(bh)) {
4016 EXT4_ERROR_INODE_BLOCK(inode, block,
4017 "unable to read itable block");
4027 int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
4029 /* We have all inode data except xattrs in memory here. */
4030 return __ext4_get_inode_loc(inode, iloc,
4031 !ext4_test_inode_state(inode, EXT4_STATE_XATTR));
4034 void ext4_set_inode_flags(struct inode *inode)
4036 unsigned int flags = EXT4_I(inode)->i_flags;
4038 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
4039 if (flags & EXT4_SYNC_FL)
4040 inode->i_flags |= S_SYNC;
4041 if (flags & EXT4_APPEND_FL)
4042 inode->i_flags |= S_APPEND;
4043 if (flags & EXT4_IMMUTABLE_FL)
4044 inode->i_flags |= S_IMMUTABLE;
4045 if (flags & EXT4_NOATIME_FL)
4046 inode->i_flags |= S_NOATIME;
4047 if (flags & EXT4_DIRSYNC_FL)
4048 inode->i_flags |= S_DIRSYNC;
4051 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4052 void ext4_get_inode_flags(struct ext4_inode_info *ei)
4054 unsigned int vfs_fl;
4055 unsigned long old_fl, new_fl;
4058 vfs_fl = ei->vfs_inode.i_flags;
4059 old_fl = ei->i_flags;
4060 new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
4061 EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|
4063 if (vfs_fl & S_SYNC)
4064 new_fl |= EXT4_SYNC_FL;
4065 if (vfs_fl & S_APPEND)
4066 new_fl |= EXT4_APPEND_FL;
4067 if (vfs_fl & S_IMMUTABLE)
4068 new_fl |= EXT4_IMMUTABLE_FL;
4069 if (vfs_fl & S_NOATIME)
4070 new_fl |= EXT4_NOATIME_FL;
4071 if (vfs_fl & S_DIRSYNC)
4072 new_fl |= EXT4_DIRSYNC_FL;
4073 } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl);
4076 static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
4077 struct ext4_inode_info *ei)
4080 struct inode *inode = &(ei->vfs_inode);
4081 struct super_block *sb = inode->i_sb;
4083 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4084 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
4085 /* we are using combined 48 bit field */
4086 i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
4087 le32_to_cpu(raw_inode->i_blocks_lo);
4088 if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) {
4089 /* i_blocks represent file system block size */
4090 return i_blocks << (inode->i_blkbits - 9);
4095 return le32_to_cpu(raw_inode->i_blocks_lo);
4099 static inline void ext4_iget_extra_inode(struct inode *inode,
4100 struct ext4_inode *raw_inode,
4101 struct ext4_inode_info *ei)
4103 __le32 *magic = (void *)raw_inode +
4104 EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize;
4105 if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC)) {
4106 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
4107 ext4_find_inline_data_nolock(inode);
4109 EXT4_I(inode)->i_inline_off = 0;
4112 struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
4114 struct ext4_iloc iloc;
4115 struct ext4_inode *raw_inode;
4116 struct ext4_inode_info *ei;
4117 struct inode *inode;
4118 journal_t *journal = EXT4_SB(sb)->s_journal;
4124 inode = iget_locked(sb, ino);
4126 return ERR_PTR(-ENOMEM);
4127 if (!(inode->i_state & I_NEW))
4133 ret = __ext4_get_inode_loc(inode, &iloc, 0);
4136 raw_inode = ext4_raw_inode(&iloc);
4138 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4139 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
4140 if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
4141 EXT4_INODE_SIZE(inode->i_sb)) {
4142 EXT4_ERROR_INODE(inode, "bad extra_isize (%u != %u)",
4143 EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize,
4144 EXT4_INODE_SIZE(inode->i_sb));
4149 ei->i_extra_isize = 0;
4151 /* Precompute checksum seed for inode metadata */
4152 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4153 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
4154 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4156 __le32 inum = cpu_to_le32(inode->i_ino);
4157 __le32 gen = raw_inode->i_generation;
4158 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
4160 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
4164 if (!ext4_inode_csum_verify(inode, raw_inode, ei)) {
4165 EXT4_ERROR_INODE(inode, "checksum invalid");
4170 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
4171 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
4172 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
4173 if (!(test_opt(inode->i_sb, NO_UID32))) {
4174 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
4175 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
4177 i_uid_write(inode, i_uid);
4178 i_gid_write(inode, i_gid);
4179 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
4181 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
4182 ei->i_inline_off = 0;
4183 ei->i_dir_start_lookup = 0;
4184 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
4185 /* We now have enough fields to check if the inode was active or not.
4186 * This is needed because nfsd might try to access dead inodes
4187 * the test is that same one that e2fsck uses
4188 * NeilBrown 1999oct15
4190 if (inode->i_nlink == 0) {
4191 if (inode->i_mode == 0 ||
4192 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
4193 /* this inode is deleted */
4197 /* The only unlinked inodes we let through here have
4198 * valid i_mode and are being read by the orphan
4199 * recovery code: that's fine, we're about to complete
4200 * the process of deleting those. */
4202 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
4203 inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
4204 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
4205 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT))
4207 ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
4208 inode->i_size = ext4_isize(raw_inode);
4209 ei->i_disksize = inode->i_size;
4211 ei->i_reserved_quota = 0;
4213 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
4214 ei->i_block_group = iloc.block_group;
4215 ei->i_last_alloc_group = ~0;
4217 * NOTE! The in-memory inode i_data array is in little-endian order
4218 * even on big-endian machines: we do NOT byteswap the block numbers!
4220 for (block = 0; block < EXT4_N_BLOCKS; block++)
4221 ei->i_data[block] = raw_inode->i_block[block];
4222 INIT_LIST_HEAD(&ei->i_orphan);
4225 * Set transaction id's of transactions that have to be committed
4226 * to finish f[data]sync. We set them to currently running transaction
4227 * as we cannot be sure that the inode or some of its metadata isn't
4228 * part of the transaction - the inode could have been reclaimed and
4229 * now it is reread from disk.
4232 transaction_t *transaction;
4235 read_lock(&journal->j_state_lock);
4236 if (journal->j_running_transaction)
4237 transaction = journal->j_running_transaction;
4239 transaction = journal->j_committing_transaction;
4241 tid = transaction->t_tid;
4243 tid = journal->j_commit_sequence;
4244 read_unlock(&journal->j_state_lock);
4245 ei->i_sync_tid = tid;
4246 ei->i_datasync_tid = tid;
4249 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4250 if (ei->i_extra_isize == 0) {
4251 /* The extra space is currently unused. Use it. */
4252 ei->i_extra_isize = sizeof(struct ext4_inode) -
4253 EXT4_GOOD_OLD_INODE_SIZE;
4255 ext4_iget_extra_inode(inode, raw_inode, ei);
4259 EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
4260 EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
4261 EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
4262 EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
4264 inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
4265 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4266 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4268 (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
4272 if (ei->i_file_acl &&
4273 !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) {
4274 EXT4_ERROR_INODE(inode, "bad extended attribute block %llu",
4278 } else if (!ext4_has_inline_data(inode)) {
4279 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
4280 if ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
4281 (S_ISLNK(inode->i_mode) &&
4282 !ext4_inode_is_fast_symlink(inode))))
4283 /* Validate extent which is part of inode */
4284 ret = ext4_ext_check_inode(inode);
4285 } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
4286 (S_ISLNK(inode->i_mode) &&
4287 !ext4_inode_is_fast_symlink(inode))) {
4288 /* Validate block references which are part of inode */
4289 ret = ext4_ind_check_inode(inode);
4295 if (S_ISREG(inode->i_mode)) {
4296 inode->i_op = &ext4_file_inode_operations;
4297 inode->i_fop = &ext4_file_operations;
4298 ext4_set_aops(inode);
4299 } else if (S_ISDIR(inode->i_mode)) {
4300 inode->i_op = &ext4_dir_inode_operations;
4301 inode->i_fop = &ext4_dir_operations;
4302 } else if (S_ISLNK(inode->i_mode)) {
4303 if (ext4_inode_is_fast_symlink(inode)) {
4304 inode->i_op = &ext4_fast_symlink_inode_operations;
4305 nd_terminate_link(ei->i_data, inode->i_size,
4306 sizeof(ei->i_data) - 1);
4308 inode->i_op = &ext4_symlink_inode_operations;
4309 ext4_set_aops(inode);
4311 } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
4312 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
4313 inode->i_op = &ext4_special_inode_operations;
4314 if (raw_inode->i_block[0])
4315 init_special_inode(inode, inode->i_mode,
4316 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
4318 init_special_inode(inode, inode->i_mode,
4319 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
4322 EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode);
4326 ext4_set_inode_flags(inode);
4327 unlock_new_inode(inode);
4333 return ERR_PTR(ret);
4336 static int ext4_inode_blocks_set(handle_t *handle,
4337 struct ext4_inode *raw_inode,
4338 struct ext4_inode_info *ei)
4340 struct inode *inode = &(ei->vfs_inode);
4341 u64 i_blocks = inode->i_blocks;
4342 struct super_block *sb = inode->i_sb;
4344 if (i_blocks <= ~0U) {
4346 * i_blocks can be represented in a 32 bit variable
4347 * as multiple of 512 bytes
4349 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4350 raw_inode->i_blocks_high = 0;
4351 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4354 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE))
4357 if (i_blocks <= 0xffffffffffffULL) {
4359 * i_blocks can be represented in a 48 bit variable
4360 * as multiple of 512 bytes
4362 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4363 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
4364 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4366 ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4367 /* i_block is stored in file system block size */
4368 i_blocks = i_blocks >> (inode->i_blkbits - 9);
4369 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4370 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
4376 * Post the struct inode info into an on-disk inode location in the
4377 * buffer-cache. This gobbles the caller's reference to the
4378 * buffer_head in the inode location struct.
4380 * The caller must have write access to iloc->bh.
4382 static int ext4_do_update_inode(handle_t *handle,
4383 struct inode *inode,
4384 struct ext4_iloc *iloc)
4386 struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
4387 struct ext4_inode_info *ei = EXT4_I(inode);
4388 struct buffer_head *bh = iloc->bh;
4389 int err = 0, rc, block;
4390 int need_datasync = 0;
4394 /* For fields not not tracking in the in-memory inode,
4395 * initialise them to zero for new inodes. */
4396 if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
4397 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
4399 ext4_get_inode_flags(ei);
4400 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
4401 i_uid = i_uid_read(inode);
4402 i_gid = i_gid_read(inode);
4403 if (!(test_opt(inode->i_sb, NO_UID32))) {
4404 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
4405 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
4407 * Fix up interoperability with old kernels. Otherwise, old inodes get
4408 * re-used with the upper 16 bits of the uid/gid intact
4411 raw_inode->i_uid_high =
4412 cpu_to_le16(high_16_bits(i_uid));
4413 raw_inode->i_gid_high =
4414 cpu_to_le16(high_16_bits(i_gid));
4416 raw_inode->i_uid_high = 0;
4417 raw_inode->i_gid_high = 0;
4420 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid));
4421 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid));
4422 raw_inode->i_uid_high = 0;
4423 raw_inode->i_gid_high = 0;
4425 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
4427 EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
4428 EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
4429 EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
4430 EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
4432 if (ext4_inode_blocks_set(handle, raw_inode, ei))
4434 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
4435 raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
4436 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
4437 cpu_to_le32(EXT4_OS_HURD))
4438 raw_inode->i_file_acl_high =
4439 cpu_to_le16(ei->i_file_acl >> 32);
4440 raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
4441 if (ei->i_disksize != ext4_isize(raw_inode)) {
4442 ext4_isize_set(raw_inode, ei->i_disksize);
4445 if (ei->i_disksize > 0x7fffffffULL) {
4446 struct super_block *sb = inode->i_sb;
4447 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
4448 EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||
4449 EXT4_SB(sb)->s_es->s_rev_level ==
4450 cpu_to_le32(EXT4_GOOD_OLD_REV)) {
4451 /* If this is the first large file
4452 * created, add a flag to the superblock.
4454 err = ext4_journal_get_write_access(handle,
4455 EXT4_SB(sb)->s_sbh);
4458 ext4_update_dynamic_rev(sb);
4459 EXT4_SET_RO_COMPAT_FEATURE(sb,
4460 EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
4461 ext4_handle_sync(handle);
4462 err = ext4_handle_dirty_super(handle, sb);
4465 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
4466 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
4467 if (old_valid_dev(inode->i_rdev)) {
4468 raw_inode->i_block[0] =
4469 cpu_to_le32(old_encode_dev(inode->i_rdev));
4470 raw_inode->i_block[1] = 0;
4472 raw_inode->i_block[0] = 0;
4473 raw_inode->i_block[1] =
4474 cpu_to_le32(new_encode_dev(inode->i_rdev));
4475 raw_inode->i_block[2] = 0;
4477 } else if (!ext4_has_inline_data(inode)) {
4478 for (block = 0; block < EXT4_N_BLOCKS; block++)
4479 raw_inode->i_block[block] = ei->i_data[block];
4482 raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
4483 if (ei->i_extra_isize) {
4484 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4485 raw_inode->i_version_hi =
4486 cpu_to_le32(inode->i_version >> 32);
4487 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
4490 ext4_inode_csum_set(inode, raw_inode, ei);
4492 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
4493 rc = ext4_handle_dirty_metadata(handle, NULL, bh);
4496 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
4498 ext4_update_inode_fsync_trans(handle, inode, need_datasync);
4501 ext4_std_error(inode->i_sb, err);
4506 * ext4_write_inode()
4508 * We are called from a few places:
4510 * - Within generic_file_write() for O_SYNC files.
4511 * Here, there will be no transaction running. We wait for any running
4512 * transaction to commit.
4514 * - Within sys_sync(), kupdate and such.
4515 * We wait on commit, if tol to.
4517 * - Within prune_icache() (PF_MEMALLOC == true)
4518 * Here we simply return. We can't afford to block kswapd on the
4521 * In all cases it is actually safe for us to return without doing anything,
4522 * because the inode has been copied into a raw inode buffer in
4523 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
4526 * Note that we are absolutely dependent upon all inode dirtiers doing the
4527 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4528 * which we are interested.
4530 * It would be a bug for them to not do this. The code:
4532 * mark_inode_dirty(inode)
4534 * inode->i_size = expr;
4536 * is in error because a kswapd-driven write_inode() could occur while
4537 * `stuff()' is running, and the new i_size will be lost. Plus the inode
4538 * will no longer be on the superblock's dirty inode list.
4540 int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
4544 if (current->flags & PF_MEMALLOC)
4547 if (EXT4_SB(inode->i_sb)->s_journal) {
4548 if (ext4_journal_current_handle()) {
4549 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
4554 if (wbc->sync_mode != WB_SYNC_ALL)
4557 err = ext4_force_commit(inode->i_sb);
4559 struct ext4_iloc iloc;
4561 err = __ext4_get_inode_loc(inode, &iloc, 0);
4564 if (wbc->sync_mode == WB_SYNC_ALL)
4565 sync_dirty_buffer(iloc.bh);
4566 if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) {
4567 EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr,
4568 "IO error syncing inode");
4577 * In data=journal mode ext4_journalled_invalidatepage() may fail to invalidate
4578 * buffers that are attached to a page stradding i_size and are undergoing
4579 * commit. In that case we have to wait for commit to finish and try again.
4581 static void ext4_wait_for_tail_page_commit(struct inode *inode)
4585 journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
4586 tid_t commit_tid = 0;
4589 offset = inode->i_size & (PAGE_CACHE_SIZE - 1);
4591 * All buffers in the last page remain valid? Then there's nothing to
4592 * do. We do the check mainly to optimize the common PAGE_CACHE_SIZE ==
4595 if (offset > PAGE_CACHE_SIZE - (1 << inode->i_blkbits))
4598 page = find_lock_page(inode->i_mapping,
4599 inode->i_size >> PAGE_CACHE_SHIFT);
4602 ret = __ext4_journalled_invalidatepage(page, offset);
4604 page_cache_release(page);
4608 read_lock(&journal->j_state_lock);
4609 if (journal->j_committing_transaction)
4610 commit_tid = journal->j_committing_transaction->t_tid;
4611 read_unlock(&journal->j_state_lock);
4613 jbd2_log_wait_commit(journal, commit_tid);
4620 * Called from notify_change.
4622 * We want to trap VFS attempts to truncate the file as soon as
4623 * possible. In particular, we want to make sure that when the VFS
4624 * shrinks i_size, we put the inode on the orphan list and modify
4625 * i_disksize immediately, so that during the subsequent flushing of
4626 * dirty pages and freeing of disk blocks, we can guarantee that any
4627 * commit will leave the blocks being flushed in an unused state on
4628 * disk. (On recovery, the inode will get truncated and the blocks will
4629 * be freed, so we have a strong guarantee that no future commit will
4630 * leave these blocks visible to the user.)
4632 * Another thing we have to assure is that if we are in ordered mode
4633 * and inode is still attached to the committing transaction, we must
4634 * we start writeout of all the dirty pages which are being truncated.
4635 * This way we are sure that all the data written in the previous
4636 * transaction are already on disk (truncate waits for pages under
4639 * Called with inode->i_mutex down.
4641 int ext4_setattr(struct dentry *dentry, struct iattr *attr)
4643 struct inode *inode = dentry->d_inode;
4646 const unsigned int ia_valid = attr->ia_valid;
4648 error = inode_change_ok(inode, attr);
4652 if (is_quota_modification(inode, attr))
4653 dquot_initialize(inode);
4654 if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) ||
4655 (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) {
4658 /* (user+group)*(old+new) structure, inode write (sb,
4659 * inode block, ? - but truncate inode update has it) */
4660 handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4661 (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb) +
4662 EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb)) + 3);
4663 if (IS_ERR(handle)) {
4664 error = PTR_ERR(handle);
4667 error = dquot_transfer(inode, attr);
4669 ext4_journal_stop(handle);
4672 /* Update corresponding info in inode so that everything is in
4673 * one transaction */
4674 if (attr->ia_valid & ATTR_UID)
4675 inode->i_uid = attr->ia_uid;
4676 if (attr->ia_valid & ATTR_GID)
4677 inode->i_gid = attr->ia_gid;
4678 error = ext4_mark_inode_dirty(handle, inode);
4679 ext4_journal_stop(handle);
4682 if (attr->ia_valid & ATTR_SIZE) {
4684 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4685 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4687 if (attr->ia_size > sbi->s_bitmap_maxbytes)
4692 if (S_ISREG(inode->i_mode) &&
4693 attr->ia_valid & ATTR_SIZE &&
4694 (attr->ia_size < inode->i_size)) {
4697 handle = ext4_journal_start(inode, EXT4_HT_INODE, 3);
4698 if (IS_ERR(handle)) {
4699 error = PTR_ERR(handle);
4702 if (ext4_handle_valid(handle)) {
4703 error = ext4_orphan_add(handle, inode);
4706 EXT4_I(inode)->i_disksize = attr->ia_size;
4707 rc = ext4_mark_inode_dirty(handle, inode);
4710 ext4_journal_stop(handle);
4712 if (ext4_should_order_data(inode)) {
4713 error = ext4_begin_ordered_truncate(inode,
4716 /* Do as much error cleanup as possible */
4717 handle = ext4_journal_start(inode,
4719 if (IS_ERR(handle)) {
4720 ext4_orphan_del(NULL, inode);
4723 ext4_orphan_del(handle, inode);
4725 ext4_journal_stop(handle);
4731 if (attr->ia_valid & ATTR_SIZE) {
4732 if (attr->ia_size != inode->i_size) {
4733 loff_t oldsize = inode->i_size;
4735 i_size_write(inode, attr->ia_size);
4737 * Blocks are going to be removed from the inode. Wait
4738 * for dio in flight. Temporarily disable
4739 * dioread_nolock to prevent livelock.
4742 if (!ext4_should_journal_data(inode)) {
4743 ext4_inode_block_unlocked_dio(inode);
4744 inode_dio_wait(inode);
4745 ext4_inode_resume_unlocked_dio(inode);
4747 ext4_wait_for_tail_page_commit(inode);
4750 * Truncate pagecache after we've waited for commit
4751 * in data=journal mode to make pages freeable.
4753 truncate_pagecache(inode, oldsize, inode->i_size);
4755 ext4_truncate(inode);
4759 setattr_copy(inode, attr);
4760 mark_inode_dirty(inode);
4764 * If the call to ext4_truncate failed to get a transaction handle at
4765 * all, we need to clean up the in-core orphan list manually.
4767 if (orphan && inode->i_nlink)
4768 ext4_orphan_del(NULL, inode);
4770 if (!rc && (ia_valid & ATTR_MODE))
4771 rc = ext4_acl_chmod(inode);
4774 ext4_std_error(inode->i_sb, error);
4780 int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
4783 struct inode *inode;
4784 unsigned long delalloc_blocks;
4786 inode = dentry->d_inode;
4787 generic_fillattr(inode, stat);
4790 * We can't update i_blocks if the block allocation is delayed
4791 * otherwise in the case of system crash before the real block
4792 * allocation is done, we will have i_blocks inconsistent with
4793 * on-disk file blocks.
4794 * We always keep i_blocks updated together with real
4795 * allocation. But to not confuse with user, stat
4796 * will return the blocks that include the delayed allocation
4797 * blocks for this file.
4799 delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb),
4800 EXT4_I(inode)->i_reserved_data_blocks);
4802 stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
4806 static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
4808 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4809 return ext4_ind_trans_blocks(inode, nrblocks, chunk);
4810 return ext4_ext_index_trans_blocks(inode, nrblocks, chunk);
4814 * Account for index blocks, block groups bitmaps and block group
4815 * descriptor blocks if modify datablocks and index blocks
4816 * worse case, the indexs blocks spread over different block groups
4818 * If datablocks are discontiguous, they are possible to spread over
4819 * different block groups too. If they are contiguous, with flexbg,
4820 * they could still across block group boundary.
4822 * Also account for superblock, inode, quota and xattr blocks
4824 static int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
4826 ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
4832 * How many index blocks need to touch to modify nrblocks?
4833 * The "Chunk" flag indicating whether the nrblocks is
4834 * physically contiguous on disk
4836 * For Direct IO and fallocate, they calls get_block to allocate
4837 * one single extent at a time, so they could set the "Chunk" flag
4839 idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
4844 * Now let's see how many group bitmaps and group descriptors need
4854 if (groups > ngroups)
4856 if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
4857 gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
4859 /* bitmaps and block group descriptor blocks */
4860 ret += groups + gdpblocks;
4862 /* Blocks for super block, inode, quota and xattr blocks */
4863 ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
4869 * Calculate the total number of credits to reserve to fit
4870 * the modification of a single pages into a single transaction,
4871 * which may include multiple chunks of block allocations.
4873 * This could be called via ext4_write_begin()
4875 * We need to consider the worse case, when
4876 * one new block per extent.
4878 int ext4_writepage_trans_blocks(struct inode *inode)
4880 int bpp = ext4_journal_blocks_per_page(inode);
4883 ret = ext4_meta_trans_blocks(inode, bpp, 0);
4885 /* Account for data blocks for journalled mode */
4886 if (ext4_should_journal_data(inode))
4892 * Calculate the journal credits for a chunk of data modification.
4894 * This is called from DIO, fallocate or whoever calling
4895 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
4897 * journal buffers for data blocks are not included here, as DIO
4898 * and fallocate do no need to journal data buffers.
4900 int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
4902 return ext4_meta_trans_blocks(inode, nrblocks, 1);
4906 * The caller must have previously called ext4_reserve_inode_write().
4907 * Give this, we know that the caller already has write access to iloc->bh.
4909 int ext4_mark_iloc_dirty(handle_t *handle,
4910 struct inode *inode, struct ext4_iloc *iloc)
4914 if (IS_I_VERSION(inode))
4915 inode_inc_iversion(inode);
4917 /* the do_update_inode consumes one bh->b_count */
4920 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
4921 err = ext4_do_update_inode(handle, inode, iloc);
4927 * On success, We end up with an outstanding reference count against
4928 * iloc->bh. This _must_ be cleaned up later.
4932 ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
4933 struct ext4_iloc *iloc)
4937 err = ext4_get_inode_loc(inode, iloc);
4939 BUFFER_TRACE(iloc->bh, "get_write_access");
4940 err = ext4_journal_get_write_access(handle, iloc->bh);
4946 ext4_std_error(inode->i_sb, err);
4951 * Expand an inode by new_extra_isize bytes.
4952 * Returns 0 on success or negative error number on failure.
4954 static int ext4_expand_extra_isize(struct inode *inode,
4955 unsigned int new_extra_isize,
4956 struct ext4_iloc iloc,
4959 struct ext4_inode *raw_inode;
4960 struct ext4_xattr_ibody_header *header;
4962 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
4965 raw_inode = ext4_raw_inode(&iloc);
4967 header = IHDR(inode, raw_inode);
4969 /* No extended attributes present */
4970 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
4971 header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
4972 memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
4974 EXT4_I(inode)->i_extra_isize = new_extra_isize;
4978 /* try to expand with EAs present */
4979 return ext4_expand_extra_isize_ea(inode, new_extra_isize,
4984 * What we do here is to mark the in-core inode as clean with respect to inode
4985 * dirtiness (it may still be data-dirty).
4986 * This means that the in-core inode may be reaped by prune_icache
4987 * without having to perform any I/O. This is a very good thing,
4988 * because *any* task may call prune_icache - even ones which
4989 * have a transaction open against a different journal.
4991 * Is this cheating? Not really. Sure, we haven't written the
4992 * inode out, but prune_icache isn't a user-visible syncing function.
4993 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
4994 * we start and wait on commits.
4996 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
4998 struct ext4_iloc iloc;
4999 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5000 static unsigned int mnt_count;
5004 trace_ext4_mark_inode_dirty(inode, _RET_IP_);
5005 err = ext4_reserve_inode_write(handle, inode, &iloc);
5006 if (ext4_handle_valid(handle) &&
5007 EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
5008 !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
5010 * We need extra buffer credits since we may write into EA block
5011 * with this same handle. If journal_extend fails, then it will
5012 * only result in a minor loss of functionality for that inode.
5013 * If this is felt to be critical, then e2fsck should be run to
5014 * force a large enough s_min_extra_isize.
5016 if ((jbd2_journal_extend(handle,
5017 EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
5018 ret = ext4_expand_extra_isize(inode,
5019 sbi->s_want_extra_isize,
5022 ext4_set_inode_state(inode,
5023 EXT4_STATE_NO_EXPAND);
5025 le16_to_cpu(sbi->s_es->s_mnt_count)) {
5026 ext4_warning(inode->i_sb,
5027 "Unable to expand inode %lu. Delete"
5028 " some EAs or run e2fsck.",
5031 le16_to_cpu(sbi->s_es->s_mnt_count);
5037 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
5042 * ext4_dirty_inode() is called from __mark_inode_dirty()
5044 * We're really interested in the case where a file is being extended.
5045 * i_size has been changed by generic_commit_write() and we thus need
5046 * to include the updated inode in the current transaction.
5048 * Also, dquot_alloc_block() will always dirty the inode when blocks
5049 * are allocated to the file.
5051 * If the inode is marked synchronous, we don't honour that here - doing
5052 * so would cause a commit on atime updates, which we don't bother doing.
5053 * We handle synchronous inodes at the highest possible level.
5055 void ext4_dirty_inode(struct inode *inode, int flags)
5059 handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
5063 ext4_mark_inode_dirty(handle, inode);
5065 ext4_journal_stop(handle);
5072 * Bind an inode's backing buffer_head into this transaction, to prevent
5073 * it from being flushed to disk early. Unlike
5074 * ext4_reserve_inode_write, this leaves behind no bh reference and
5075 * returns no iloc structure, so the caller needs to repeat the iloc
5076 * lookup to mark the inode dirty later.
5078 static int ext4_pin_inode(handle_t *handle, struct inode *inode)
5080 struct ext4_iloc iloc;
5084 err = ext4_get_inode_loc(inode, &iloc);
5086 BUFFER_TRACE(iloc.bh, "get_write_access");
5087 err = jbd2_journal_get_write_access(handle, iloc.bh);
5089 err = ext4_handle_dirty_metadata(handle,
5095 ext4_std_error(inode->i_sb, err);
5100 int ext4_change_inode_journal_flag(struct inode *inode, int val)
5107 * We have to be very careful here: changing a data block's
5108 * journaling status dynamically is dangerous. If we write a
5109 * data block to the journal, change the status and then delete
5110 * that block, we risk forgetting to revoke the old log record
5111 * from the journal and so a subsequent replay can corrupt data.
5112 * So, first we make sure that the journal is empty and that
5113 * nobody is changing anything.
5116 journal = EXT4_JOURNAL(inode);
5119 if (is_journal_aborted(journal))
5121 /* We have to allocate physical blocks for delalloc blocks
5122 * before flushing journal. otherwise delalloc blocks can not
5123 * be allocated any more. even more truncate on delalloc blocks
5124 * could trigger BUG by flushing delalloc blocks in journal.
5125 * There is no delalloc block in non-journal data mode.
5127 if (val && test_opt(inode->i_sb, DELALLOC)) {
5128 err = ext4_alloc_da_blocks(inode);
5133 /* Wait for all existing dio workers */
5134 ext4_inode_block_unlocked_dio(inode);
5135 inode_dio_wait(inode);
5137 jbd2_journal_lock_updates(journal);
5140 * OK, there are no updates running now, and all cached data is
5141 * synced to disk. We are now in a completely consistent state
5142 * which doesn't have anything in the journal, and we know that
5143 * no filesystem updates are running, so it is safe to modify
5144 * the inode's in-core data-journaling state flag now.
5148 ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
5150 jbd2_journal_flush(journal);
5151 ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
5153 ext4_set_aops(inode);
5155 jbd2_journal_unlock_updates(journal);
5156 ext4_inode_resume_unlocked_dio(inode);
5158 /* Finally we can mark the inode as dirty. */
5160 handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
5162 return PTR_ERR(handle);
5164 err = ext4_mark_inode_dirty(handle, inode);
5165 ext4_handle_sync(handle);
5166 ext4_journal_stop(handle);
5167 ext4_std_error(inode->i_sb, err);
5172 static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
5174 return !buffer_mapped(bh);
5177 int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
5179 struct page *page = vmf->page;
5183 struct file *file = vma->vm_file;
5184 struct inode *inode = file_inode(file);
5185 struct address_space *mapping = inode->i_mapping;
5187 get_block_t *get_block;
5190 sb_start_pagefault(inode->i_sb);
5191 file_update_time(vma->vm_file);
5192 /* Delalloc case is easy... */
5193 if (test_opt(inode->i_sb, DELALLOC) &&
5194 !ext4_should_journal_data(inode) &&
5195 !ext4_nonda_switch(inode->i_sb)) {
5197 ret = __block_page_mkwrite(vma, vmf,
5198 ext4_da_get_block_prep);
5199 } while (ret == -ENOSPC &&
5200 ext4_should_retry_alloc(inode->i_sb, &retries));
5205 size = i_size_read(inode);
5206 /* Page got truncated from under us? */
5207 if (page->mapping != mapping || page_offset(page) > size) {
5209 ret = VM_FAULT_NOPAGE;
5213 if (page->index == size >> PAGE_CACHE_SHIFT)
5214 len = size & ~PAGE_CACHE_MASK;
5216 len = PAGE_CACHE_SIZE;
5218 * Return if we have all the buffers mapped. This avoids the need to do
5219 * journal_start/journal_stop which can block and take a long time
5221 if (page_has_buffers(page)) {
5222 if (!ext4_walk_page_buffers(NULL, page_buffers(page),
5224 ext4_bh_unmapped)) {
5225 /* Wait so that we don't change page under IO */
5226 wait_for_stable_page(page);
5227 ret = VM_FAULT_LOCKED;
5232 /* OK, we need to fill the hole... */
5233 if (ext4_should_dioread_nolock(inode))
5234 get_block = ext4_get_block_write;
5236 get_block = ext4_get_block;
5238 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
5239 ext4_writepage_trans_blocks(inode));
5240 if (IS_ERR(handle)) {
5241 ret = VM_FAULT_SIGBUS;
5244 ret = __block_page_mkwrite(vma, vmf, get_block);
5245 if (!ret && ext4_should_journal_data(inode)) {
5246 if (ext4_walk_page_buffers(handle, page_buffers(page), 0,
5247 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access)) {
5249 ret = VM_FAULT_SIGBUS;
5250 ext4_journal_stop(handle);
5253 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
5255 ext4_journal_stop(handle);
5256 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
5259 ret = block_page_mkwrite_return(ret);
5261 sb_end_pagefault(inode->i_sb);